PMID- 10665265
TI - Neuropsychiatry of Huntington's disease and other basal ganglia disorders.
AB - Degenerative diseases of the basal ganglia, such as Huntington's disease (HD),
Parkinson's disease, and Wilson's disease, are characterized by motor, cognitive,
and psychiatric manifestations. HD, in particular, can be considered a
paradigmatic neuropsychiatric disorder that has all three components of the
"Triadic Syndromes": dyskinesia, dementia, and depression. The authors examine
the phenomenology, prevalence, and management of psychiatric disturbances
occurring in diseases of the basal ganglia. They address psychiatric conditions
such as depression, mania, psychosis, obsessive-compulsive disorders, aggression,
irritability, apathy, sexual disorders, and delirium, discussing subtleties of
diagnosis, and making reference to more unusual disorders of the basal ganglia,
such as postencephalitic parkinsonism and Fahr's disease.
PMID- 10665266
TI - The psychiatric perspectives of epilepsy.
AB - Psychiatric conditions occur frequently in epilepsy, and their manifestations are
diverse. Evaluation and management require knowledge of disease processes
relevant to epilepsy and to psychiatry, as well as the role of other factors that
affect the expression of psychiatric illnesses: behaviors, temperament,
cognition, and life events. This article describes a comprehensive approach for
addressing psychiatric issues in epilepsy patients.
PMID- 10665267
TI - Interventions to improve provider diagnosis and treatment of mental disorders in
primary care. A critical review of the literature.
AB - The authors conducted a critical review of the literature on interventions to
improve provider recognition and management of mental disorders in primary care,
searching the MEDLINE database for relevant articles published from 1966 through
May 1998 and finding 48 usable controlled studies (27 randomized controlled
trials and 21 quasi-experimental studies). Improved diagnosis of mental disorders
was reported in 18 of 23 (78%) of the studies examining this outcome and improved
treatment in 14 of 20 studies (70%); clinical improvement in psychiatric symptoms
or functional status was documented in 4 of 11 and 4 of 8 (36% and 50%,
respectively). Considerable study heterogeneity precluded subjecting the
literature synthesis to a formal meta-analysis of pooled results; the authors
were therefore unable to demonstrate an association between efficacy of an
intervention and any specific variables. A variety of interventions and further
research may be effective in improving the recognition and management of mental
disorders in primary care.
PMID- 10665268
TI - Sharing mental health care. Training psychiatry residents to work with primary
care physicians.
AB - Overcoming problems in communication between psychiatry and primary care requires
new models of collaboration. Their success will depend upon the ability of
participants to work productively with each other, which will require psychiatry
residency programs to offer appropriate preparation for future graduates in
working with primary care physicians. This article, based on the training at
McMaster University in Hamilton, Ontario, describes a brief curriculum for
training psychiatry residents to work effectively with primary care physicians
that can be easily integrated with current training rotations and looks at
adjustments academic departments need to make to support such programs.
PMID- 10665269
TI - Psychiatric complications of Ma-huang.
PMID- 10665270
TI - QT interval prolongation associated with quetiapine (Seroquel) overdose.
PMID- 10665271
TI - Psychiatric effects of anabolic steroids after burn injuries.
PMID- 10665272
TI - Low-dose risperidone for the irritable medically ill patient.
PMID- 10665273
TI - A psychotic manic state induced by an herbal preparation.
PMID- 10665274
TI - Panic disorder with agoraphobia in reaction to gastroenteritis.
PMID- 10665275
TI - [Clinical variants of glaucoma in patients with acquired high myopia].
AB - Examinations of 88 glaucoma patients with high myopia showed three variants of
glaucoma: 1) mixed form with combination of nuclear cataract and lenticular
myopia, 2) open-angle form with ischemic background cerebral circulation (ocular
circulation deficiency combined with a decrease in linear velocity of the
bloodflow in the intracranial collateral cerebral circulation: to 21.8% in the
anterior cerebral artery, to 26.1% in the middle cerebral artery, and to cerebral
artery (by 8.3%) and in the orbital artery (by 4.2%). Clinical values indicate
impeded venous outflow. Differential diagnostic signs of glaucoma in high myopia
are defined.
PMID- 10665276
TI - [Endoscopic laser coagulation of ciliary processes in patients with severe
uncompensated glaucoma].
AB - Endoscopic laser coagulation was used in 85 patients with severe uncompensated
glaucoma. A manifest hypotensive effect (decrease of intraocular pressure from
44.21 +/- 3.17 to 23.12 +/- 4.58 mm Hg 1 year after the operation) and analgesic
effect were attained. As a result of treatment, intraocular pressure normalized
in 88.2% patients and the eyeball was preserved in 98.8% patients subjected to
surgery.
PMID- 10665277
TI - [Clinical and pathogenetic features of neurotrophic corneal disorders in
diabetes].
AB - The corneal neurotrophic status was evaluated in 110 patients (220 eyes) with
diabetes mellitus and in 20 normal controls (40 eyes). Corneal abnormalities
(gerontoxon, limb vascularization, punctate keratopathy, endothelial dystrophy,
relapsing erosion, corneal ulcers) were detected in 73.6% diabetics. Corneal
changes depended on the type, duration, and compensation of diabetes mellitus.
Based on the diagnostic markers (threshold sensitivity of the cornea,
microcirculatory status, bulbar conjunctiva status, level of lacrimal production,
cellular composition of the limb smears impressions, lacrimal levels of
catecholamines, hydroperoxides, and lipids), three types of diabetic neuropathy
of the cornea were distinguished: vegetative, sensory, and vegetosensory. Corneal
changes were associated with signs of diabetic neuropathy in 55.6% cases and with
autonomic nervous disorders of the cardiovascular system in 46.9% cases, which
evidences a generalized involvement. The detected neurotrophic features of the
cornea should be borne in mind when choosing pathogenetic therapy for diabetics
with corneal complications and preparing the patients to ocular surgery.
PMID- 10665278
TI - [Objective method for epithelialization and corneal transparency monitoring after
excimer laser keratectomy].
AB - The area of corneal epithelialization was evaluated and densitometry of corneal
surface carried out by computer analysis of images in order to detect the
relationship between epithelialization and formation of corneal fleur in patients
with delayed healing after photorefraction keratectomy for hypermetropia. An
arbitrary parameter: corneal epithelialization rate, a mathematical difference
between the area of corneal defect every next day of observation in comparison
with the day before, expressed in mm2/day, is proposed for evaluating the
efficacy of various drugs used to stimulate corneal defect epithelialization.
Computer analysis of images helps objectively evaluate epithelialization and
corneal transparency after eximer laser keratectomy. The method is diagnostically
and prognostically valuable, particularly in cases with delayed epithelialization
and stubborn epithelial defects of the cornea.
PMID- 10665279
TI - [New stimulants of corneal reparative regeneration].
AB - The efficacy of corneregel, a drug containing pantothenic acid, a component of
coenzyme A, in healing of corneal wounds has been evaluated. The study was
carried out on 19 rabbits (38 eyes) with standard corneal defect made with a 5-mm
trephine for lamellar transplantation of the cornea, divided into 2 groups: 1)
instillations of corneregel (10 eyes) and 0.25% levomycetin solution (10 eyes)
and 2) 20% solcoseryl gel (9 eyes) and 0.25% levomycetin (9 eyes). Time course of
changes were evaluated by biomicroscopy (fluorescent test), histologically
(hematoxylin-eosin staining), and immunohistochemically after 1, 2, 4, 7, 30, and
90 days. Proliferative activity was studied by expression of the proliferating
cell nuclear antigen and the migration capacity of cells by expression of alpha
smooth muscle actin. The terms of epithelialization were as follows: corneregel
10 +/- 7 h, 20% solcoseryl gel 108 +/- 10 h, levomycetin 124 +/- 6.93 h. Earlier
epithelialization in the corneregel group was apparently due to increased
expression of alpha-smooth muscle actin and increase in the cell migration
capacity. Hence, corneregel is recommended for practical use as a stimulant of
reparative regeneration of the cornea.
PMID- 10665280
TI - [Combined revascularizing method for treating central atherosclerotic
chorioretinopathy].
AB - The authors present a new surgical method for treatment of central
atherosclerotic chorioretinopathies, consisting of choroid revascularization
followed by crossing of the surface temporal artery. Combined revascularizing
method improved local ocular hemodynamics and the visual function in 64% patients
with pseudotumorous condition and in 81% patients with the "dry" form,
stabilizing the process for up to 12 months (period of observation).
Morphological analysis showed that after choroid revascularization, a full-value
functioning vascular network forms at the interface between the vascular membrane
and implanted tissues, and therefore crossing of the surface temporal artery
should be performed no earlier than 3 months after choroid revascularization.
PMID- 10665281
TI - [Peripheral chorioretinal dystrophy and astigmatism of myopic eyes: statistical
evaluation, relationship and clinical significance].
AB - A clinically significant relationship between the myopic eye astigmatism and
manifestation of peripheral chorioretinal dystrophies in them in young patients
is described. A simple and effective method for predicting peripheral vascular
chorioretinal dystrophies in myopic patients is proposed, based on the presence
and severity of astigmatism. The incidence of various dystrophies in spherical
and aspherical myopia is 32 and 78%, respectively. Dystrophies fraught with
retinal detachment occur three times more often in astigmatic eyes, which are
characterized by a more flat lens.
PMID- 10665282
TI - [Morphology of conjunctival progressive nevus].
AB - Structural features of 59 progressive nevuses of the conjunctiva were studied.
The proliferation of the epithelium and melanocytes is partially compensated by
spontaneous regression of the nevus structures. The growth of a nevus is
structurally similar to tumor growth, but the nevuses lack the melanocyte
dysplasia, the main sign of malignant degeneration. The immune reactions are
involved in the tissue restructuring of the growing nevus. Permanent foci of
photoelastosis reflect the significance of ultraviolet exposure as a factor of
risk of the nevuses progress.
PMID- 10665283
TI - [Radionuclide imaging of lacrimal duct in health and disease].
AB - Dacryoscintigraphy is a perspective method for examination of the lacrimal system
function. It has many advantages over other methods (functional tests,
roentgenography, and computer-aided tomography) and notably improves the
diagnostic potentialities of examination of the lacrimal function. The technique
and results of the method are discussed.
PMID- 10665284
TI - [Prediction of infectious complications of eye penetrating wounds by R protein
concentration in lacrimal fluid].
AB - Analysis of the lacrimal fluid of normal subjects and patients after cataract
extraction and with penetrating wounds of the eyeball showed fluctuations of the
R protein concentration, which depended on the type of the injury and its
complications. The authors propose using measurements of R protein in the
lacrimal fluid as a prognostic criterion predicting the development of infectious
complications in penetrating wounds of the eyeball.
PMID- 10665285
TI - Electroretinographic characteristics of proliferative vitreoretinopathy in
rhegmatogenous detachment of retina.
AB - Thirty-five patients with types A, B, C2, C3, and D1 proliferative
vitreoretinopathy (PVR) were followed up for 8-14 months after surgical treatment
of rhegmatogenic amotio retinae. Hanz-Feld electroretinogram (ERG), rhythmic ERG
to low and high-frequency stimulation, and macular ERG were recorded. Before
surgery all patients presented with specific signs of changes in the retinal
electrogenesis, characteristic of rhegmatogenic amotio retinae with PVR of
different types. Comparative analysis of ERG and rhythmic ERG alteration showed a
more expressed reaction of Mueller's glial cells in patients with types A-C2 PVR
and of second order neurons in the internal nuclear layer of the retina in those
with types C3 and D1 PVR. Characteristic changes in the retinal functional
activity were detected, possessing a prognostic significance. According to
electrophysiological studies, the decisive factor for predicting the course of
recovery after surgical treatment of retinal detachment is the preoperative
function of retinal neurons. A drastic depression of low-frequency rhythmic ERG
is the most unfavorable sign in prognosis of the postoperative time course of
visual functions. The least favorable course of recovery after the operation is
typical of amotio retinae with type C3 PVR. Recovery of amplitudes of different
biopotentials and functional horizontal bonds at different levels of the retinal
structure is different.
PMID- 10665286
TI - [Parameters of blood proteinase inhibitor balance and hyperlipoproteinemia in
patients with proliferative diabetic retinopathy with vitreous hemorrhage].
AB - The parameters of proteinase-inhibitor balance and lipid metabolism were studied
in the blood of patients with proliferative diabetic retinopathy. Metabolic
disorders in patients with proliferative diabetic retinopathy with hemophthalmia
are characterized by a notable increase in the activities of trypsin-like enzymes
and alpha 2-macroglobulin level and normal activity of alpha 1-antitrypsin and
shifted lipid metabolism parameters characteristic of types IIb and IV
hyperlipoproteinemia. These data indicate a necessity of monitoring lipid
metabolism and proteinase-inhibitor balance in patients with diabetic retinopathy
in order to detect subjects at a high risk of hemophthalmia and timely start drug
correction for preventing this complication.
PMID- 10665287
TI - [Relationship between perinatal pathology and refractogenesis, incidence and type
of ocular diseases in children].
AB - Three-year-old children with a history of perinatal diseases differed from
healthy age-matched children by a higher incidence of ocular diseases (78.9% vs.
21.6% in the control, p < 0.001). These children often presented with severe
visual disorders: partial atrophy and hypoplasia of ocular nerves (7.2%),
congenital abnormalities in the eyeball membranes (5.2%), retinopathy neonatorum
(5.2%), cortical blindness (3.1%), oculomotor disorders (20.8%), and congenital
deformations of the eyelids (19.7%). Disorders of refractogenesis in these
children presented as a higher incidence of myopia (19.8% vs. 3.8% in the
control, p < 0.001) and a shift of the percentage of refraction abnormalities
towards myopia. Therefore, all children with a history of perinatal disease
should be referred to a group at a high risk of ocular disease.
PMID- 10665288
TI - [Interferon status of patients with uveal melanoma].
AB - Interferon status of patients with uveal melanoma was studied at different stages
of the disease. All parameters of alpha- and gamma-interferon production were
decreased both in vitro and in vivo. The T2-3 stages were associated with an
imbalance of the production of two interferon types: augmenting deficiency of
alpha-interferon with a tendency to a higher production of gamma-interferon by
leukocytes in vitro. Generalization of T3-4N0Mhep melanoma was characterized by
hyperproduction of gamma-interferon and total serum interferon. These data
indicate a pathogenetic significance of disorders in interferon production in
uveal melanoma and may be used for the disease prognosis.
PMID- 10665289
TI - [Therapy of fundus oculi vascular pathology by solcoseryl].
AB - Long (for more than 17 years) therapy of 2331 patients (3122 eyes) with vascular
conditions of the fundus oculi by a retinotropic drug solcoseryl showed its high
efficacy as a monotherapy and in complex with other traditional and symptomatic
treatments. Solcoseryl improved the visual function and hemodynamics of retinal
vessels, promoted a more stable and longer stabilization of the treatment
results, and accelerated the rehabilitation of patients.
PMID- 10665290
TI - [Effects some drugs of re-epithelialization in the early postoperative period
after photorefraction keratectomy].
AB - Terms of re-epithelialization, severity of the painful syndrome, intensity of
corneal "crepe" (opacity) are assessed in myopic patients treated by maxitrol,
eubetal, colbiocin ointments and maxitrol eyedrops in the early postoperative
period after photorefraction keratectomy. The crepe intensity was assessed
routinely according to a clinical score: 0) transparent cornea, 1) trace crepe;
2) moderate crepe; and 3) intensive crepe. Biomicroscopy on day 4 after
photorefraction keratectomy showed complete epithelialization in 91.7% patients
after colbiocin ointment, in 91.% after maxitrol eyedrops, 87% after eubetal
ointment, and 82.6% after maxitrol ointment. The least corneal opacity (0 and 0
1) was observed after eubetal ointment and maxitrol eyedrops. The mean score for
pain was virtually the same in all groups; in the colbiocin ointment group more
patients complained of pain for more than 24 h in comparison with other groups.
PMID- 10665291
TI - [Optic nerve hypoplasia].
PMID- 10665292
TI - [Endocrine ophthalmopathy].
PMID- 10665293
TI - Detailed diagnoses and procedures, National Hospital Discharge Survey, 1997.
AB - OBJECTIVES: This report presents national estimates of the use of non-Federal
short-stay hospitals in the United States during 1997. Estimates of first-listed
diagnoses, all-listed diagnoses, days of care for first-listed diagnoses, and all
listed procedures are shown by sex and age of patient and geographic region of
hospital. METHODS: The estimates are based on data collected through the National
Hospital Discharge Survey for 1997. The survey has been conducted annually by the
National Center for Health Statistics since 1965. In 1997 data were collected for
approximately 300,000 discharges from 474 non-Federal short-stay hospitals.
Diagnoses and procedures are presented according to their code number in the
International Classification of Diseases, 9th Revision, Clinical Modification
(ICD-9-CM).
PMID- 10665294
TI - [The power of numbers].
AB - The round figure for the current year has stirred people's minds in anticipation.
Numbers have acquired great significance also in today's medical science. The
Paris physician Pierre Charles Alexandre Louis (1787-1872) is considered the
founding father of the numerical method in medicine. At first the principle of
aggregating data from different individuals aroused much resistance and even
disgust: Claude Bernard was a leading figure among those who warned that one will
never find a mean in nature, and that grouping findings together obscures the
true relationship between biological phenomena. True enough, statistical
significance is not a characteristic of nature itself. Significant differences or
risk reductions do not necessarily imply clinical relevance, and results obtained
in a group of patients are rarely applicable to an individual patient in the
consultation room. Likewise, the health of a human being cannot be captured in
biochemical, radiological or other technical measures, nor in disease-specific
scales that reduce well-being to one or two digits. The editors of this journal
will remain keen on publishing numerical studies that contribute to evidence
based medicine, but at the same time they will continue to foster the art of
reporting illness from the point of view of the sick person.
PMID- 10665295
TI - [1999, the year of fired editors-in-chief].
AB - In the past year three editors of medical scientific journals stepped back, a
remarkable fact for a relatively quiet profession. G. Lundberg was dismissed. J.
Kassirer was forced out and F. Meijman resigned. There are differences and
similarities in these events. Lundberg of The Journal of the American Medical
Association (JAMA) was dismissed because of his interference with regular points
of view of the board of the American Medical Association, whereas Kassirer of The
New England Journal of Medicine was forced out mainly because of his refusal to
allow use of the name and reputation of his journal for other medical and lay
publications by the Massachusetts Medical Association; Meijman resigned because
he disagreed with the changes in the scientific contents of Huisarts en
Wetenschap (General Practitioner and Medical Science) proposed by the board of
the general practitioners' association that owns the journal. The similarity is
that editorial freedom appears to be a relative concept. Owners, whether
societies or publishers, can fire displeasing editors or force them to leave. The
consequences could be harmful, to the owners, but especially to the journals,
because of loss of impact, credibility and trust by authors, reviewers and
readers. The only basis for a constructive co-operation between owners and
editors is mutual trust. Immediate firing of editors is not possible at the
Nederlands Tijdschrift voor Geneeskunde (Dutch Journal of Medicine). The
association that owns the journal consists of (former) members of the editorial
board. A committee of the association assesses every year the editorial decisions
and policies retrospectively. Subsequently the editors may be reappointed for
another year by a vote of the general assembly of the association. If they are
not reappointed, an administrative procedure will be initiated to terminate their
contract.
PMID- 10665296
TI - [Epilepsy, disturbances of behavior and consciousness in presence of normal
thyroxine levels: still, consider the thyroid gland].
AB - Three patients, one man aged 51 years, and two women aged 49 and 52 years, had
severe fluctuating and progressive neurological and psychiatric symptoms. All
three had normal thyroxine levels but elevated thyroid stimulating hormone levels
and positive thyroid antibodies. Based on clinical, laboratory, MRI and EEG
findings they were eventually diagnosed with Hashimoto's encephalopathy,
associated with Hashimoto thyroiditis. Treatment with prednisone in addition to
thyroxine suppletion resulted in a remarkable remission of their neuropsychiatric
symptoms. The disease is probably under-recognized.
PMID- 10665297
TI - [Laparoscopic inguinal hernia operation].
AB - After the introduction of laparoscopic operations for repair of inguinal hernias,
circa 1990, randomized comparative studies showed that this method causes less
postoperative pain and requires a shorter recovery period than conventional
operations. The duration of follow-up is still too short for comparison of
proportions of recurrences. The costs of laparoscopic interventions are higher
for the hospital (among other things because of the use of disposable
instruments) and lower for society (because of shorter absenteeism).
Implementation of the intervention by allotment of a higher fee to hospitals has
not been done, because meanwhile a third method--conventional surgery with
implantation of a prosthetic mesh in ambulatory surgery--has become possible. A
meta-analysis based on European registration of all treated patients will once
more have to demonstrate what method of treatment is to be preferred.
PMID- 10665298
TI - [Phenylketonuria: a children's disease in adulthood].
AB - The prognosis for patients with phenylketonuria (PKU) has improved greatly with
early institution of treatment after birth. It was assumed that the diet could be
terminated after adolescence but there are strong indications that
hyperphenylalaninaemia can have detrimental effects in adult patients.
Hyperphenylalaninaemia can cause reversible white matter abnormalities, and is
also associated with psychiatric illness, which improves with lowering of the
plasma phenylalanine level. Even optimally treated patients generally have a
decreased performance with neuropsychological tests compared with subjects
without PKU. Elevation of the plasma phenylalanine level leads to worsening of
neuropsychological performance, lowering of the level leads to improved
performance. Strict metabolic control is necessary during pregnancy in women with
PKU in view of the increasing frequency of congenital abnormalities with
increasing phenylalanine level. The complexity and demanding nature of the diet
treatment make specialised facilities for optimal medical and paramedical care
mandatory.
PMID- 10665299
TI - [Respiratory syncytial virus infections and preventive options].
AB - Respiratory syncytial virus (RSV) is the most prominent pathogen found in
respiratory tract infections in children and the most important cause of
bronchiolitis in the first two years of life. In the Netherlands approximately
2000 children are admitted each winter season. A serious course is mostly seen in
children younger than 3 months, (ex-)prematures, children with bronchopulmonary
dysplasia or congenital cardiac anomalies, children with cystic fibrosis younger
then 2 years and children with impaired T cell immunity; such cases not rarely
require intensive care. Treatment (fluid, nutrition, bronchodilator agents,
corticosteroids, oxygen and ventilation) is usually symptomatic. Antiviral
therapy is only indicated in immunodeficient patients. For prevention by passive
immunization palivizumab was recently registered in the Netherlands, a monoclonal
antibody against RSV that has to be administered intramuscularly from the start
of the RSV season (15 mg per kg bodyweight once a month during five months). In a
number of large-scale American multicenter studies both the number of hospital
admissions related to RSV infection and the mean duration of hospital stay showed
a statistically significant reduction in high-risk children who had been treated
with palivizumab. Palivizumab appears to be indicated in children from the
categories with an increased risk for serious RSV disease.
PMID- 10665300
TI - [Low incidence of nosocomial respiratory syncytial virus infections among
children younger than 12 months in the Department of Pediatrics, Sophia
Children's Hospital at Rotterdam].
AB - OBJECTIVE: To investigate the occurrence of nosocomial respiratory syncytial
virus (RSV) infections and to compare their clinical features with those of
community-acquired RSV infections. DESIGN: Retrospective. METHOD: Data were
collected from the medical records of children younger than 12 months with RSV
infection in the Department of Pediatrics of Sophia's Children's Hospital,
Rotterdam, the Netherlands, in October-March 1992/'95. The diagnosis of 'RSV
infection' was confirmed by a direct immunofluorescent assay and/or a viral
culture on materials obtained from nasopharyngeal washes. A nosocomial RSV
infection was defined as an infection which occurred more than 5 days after
hospital admission for any underlying disease. RESULTS: During the 3 RSV seasons
1260 children were admitted. Of these 34 (2.7%) developed a nosocomial RSV
infection. The number of nosocomial RSV infections decreased over the study
period. At the department including the outpatient clinic 232 children were seen
with a community-acquired RSV infection. Children with a nosocomial infection
differed from children with a community-acquired infection only with regard to
birth weight (2.5 kg versus 3.0 kg), cough (65% versus 92%) and feeding problems
(100% versus 69%). Four children had bronchopulmonary dysplasia and nosocomial
RSV infection; these required mechanical ventilation. CONCLUSION: The number of
nosocomial RSV infections decreased over 3 years. The severity of nosocomial RSV
infections was comparable with that of community-acquired RSV infections.
PMID- 10665301
TI - [Man with cherubism].
AB - Cherubism was diagnosed in a male when he was 6 years old. Cherubism is a benign,
bilateral, painless lesion. It is commonly located in the mandible but in a
minority of patients also in the maxilla. Cherubism is a familial condition with
an autosomal dominant pattern of inheritance. At least one member of the family
of the patient described had cherubism. The disease becomes manifest during early
childhood and progresses until puberty when it spontaneously regresses. In the
majority of patients no treatment is required. However, in the patient presented
surgical procedures and odontological corrections were necessary. Due to a flare
up of the disease at the age of 22 years, the patient was treated with calcitonin
for 1 year followed by bisphosphonates. During these treatments the disease
symptoms diminished.
PMID- 10665302
TI - [Value of a Dutch medical license in Egypt].
AB - Shortly after moving from the Netherlands to Egypt, the author, a physician,
started procedures to get his medical certificate recognized. These procedures
began at the Egyptian Medical Association, housed in the Dar al-Hikmah ('House of
Wisdom'). The Association first required a comparison between the Netherlands and
the Egyptian medical education, to be made by the Supreme Council of
Universities. There, the differences between the two systems appeared to be
fertile soil for confusion and discussions. After nine months, however, and the
translation of all relevant papers into Arabic, the Supreme Council declared the
Dutch medical education equivalent to the Egyptian. Now only the permission of
the Ministry of Health and Population was required. This Ministry inquired at the
Ministry of Foreign Affairs whether an Egyptian education would be recognized in
the Netherlands, in order for the 'principle of reciprocity' to be applied. The
reply of the Dutch Embassy was positive but progress has stopped since. A
registration as a physician in the United Kingdom was obtained without problems
and in a short time; this registration might be helpful in efforts to resume the
process in Egypt.
PMID- 10665303
TI - [New diagnostic technology often offers no advantage in the differential
diagnosis of acute abdomen].
PMID- 10665304
TI - [Bilateral blood pressure measurement before and after coronary bypass surgery :
an absolute necessity].
PMID- 10665305
TI - [Hypertensive crisis: definition, pathophysiology and treatment].
PMID- 10665306
TI - [Autopsies as an important indicator for quality control].
PMID- 10665307
TI - [The "Year 2000 problem"].
PMID- 10665308
TI - [Mechanisms of tachyphylaxis in regional anesthesia of long duration].
AB - Tachyphylaxis to local anesthetics is defined as a decrease in duration,
segmental spread or intensity of a regional block despite repeated constant
dosages. However, there is disagreement about the incidence of tachyphylaxis. In
contrast to tachyphylaxis, pseudotachyphylaxis denotes time dependent variations
in pain or circadian changes in the duration of local anesthetic action.
Tachyphylaxis appears neither to be linked to structural or pharmacological
properties of the local anesthetics nor to the technique or mode of their
administration. The mechanisms underlying tachyphylaxis are open to debate and
include changes in pharmacokinetics or pharmacodynamics. Considering
pharmacokinetics, local edema, an increased epidural protein concentration,
changes in local anesthetic distribution in the epidural space or a decrease of
perineural pH could result in decreased diffusion of the local anesthetics from
the epidural space to their binding sites at the sodium channel. Increased
clearance of local anesthetics from the epidural space may be caused both by
increased epidural blood flow or increased local metabolism. Considering
pharmacodynamics, antagonistic effects of nucleotides or increased sodium
concentration, increased afferent input from nociceptors or receptor down
regulation of the sodium channels have been implicated. However, none of these
theoretical considerations is supported strongly enough by data to explain
tachyphylaxis. A new possibility to maintain for a longer time neural blockade is
the design of new ultralong-acting local anesthetics. Liposomal formulations of
local anesthetics also appear suitable to provide longer lasting regional
anesthesia. The recent observation that NMDA-antagonists as well as NO-synthase
inhibitors prevent the development of tachyphylaxis suggests involvement of the
nitric oxide pathway in the development of tachyphylaxis. Accordingly, NMDA
antagonists or NO-synthase-inhibitors may prevent tachyphylaxis.
PMID- 10665309
TI - [Anesthesia monitoring: degree of compliance with guidelines in Austria].
AB - PURPOSE: For the first time an evaluation of standard anesthetic monitoring was
performed according to the guidelines of the Austrian Society for Anesthesiology,
Resuscitation und Intensive Care Medicine (OGARI). METHODS: A questionnaire was
delivered to all medical institutions performing anesthesia in Austria. A
descriptive statistical evaluation was performed on all returned and completed
questionnaires. RESULTS: Generally, there is a high standard in compulsory
monitoring and in PACU (actual compliance > 99%/85.8%). Supplemental equipment is
required for disconnection alarm and measurement of inspired oxygen concentration
(actual compliance: 98.3%/98.9%). Furthermore, measurement for inspired
concentration of volatile anesthetics and relaxometry (actual compliance
68.7%/47.3%) has yet to be completed. University departments and regional
hospitals have comparable standards (82.2% vs. 79.6%). CONCLUSIONS: For the first
time an Austrian-wide evaluation of anesthetic monitoring investigated the
compliance with the 1992 recommendations of the Austrian Society of
Anesthesiology, Resuscitation and Intensive Care Medicine. The data demonstrate
that these recommendations including the anesthetic monitoring equipment have
already been implemented to a high degree.
PMID- 10665310
TI - [Respiratory and circulatory parameters as indicators of the postoperative
analgesic demand in newborns and infants].
AB - AIM OF THE STUDY: Due to immature cognitive functions, infants are unable to
communicate their pain perception verbally. To assess postoperative analgesic
demand, the anaesthetist has to rely on observational techniques. Generally, pain
expression is considered to be a multidimensional phenomenon consisting of
physiological, motor-reflex and behavioural patterns. The majority of
observational approaches to pain assessment in infants use the behavioural
dimension only, regardless of the fact that pain perception might contribute
substantially to the stress response. The aim of this study is to evaluate,
whether sensitivity and specificity of a behavioural pain scale (CHIPPS [1]) can
be improved by adding physiological measures, especially those representing the
stress response. PATIENTS AND METHODS: 30 infants aged 0-12 months and scheduled
for unilateral herniorrhaphy were studied prospectively. In addition to 9
behavioural items (crying, facial expression, wrinkling of the forehead, motoric
restlessness; posture of fingers, arms, legs, toes and torso) the ratio of actual
physiological measurements (heart rate, respiratory rate, blood pressure) and
their respective preoperative baseline values were recorded by a single observer
in 5 minutes intervals during the first hour after recovery from anaesthesia.
Maximal efforts were made to achieve valid measures. Factor analysis was
performed to determine the dimensionality of the complete item pool. For
additional validity testing, receiver operating characteristic curves (ROC) were
calculated using the independent opinion of an experienced clinician as an
external criterion. Discriminant analysis was performed to assess the accuracy of
a combined behavioural and physiological scale. RESULTS: The factor analysis
resulted in two independent dimensions: behaviour and cardiocirculatory
measurements. The strong intercorrelations of all behavioural items and the fact,
that the affective pain experience is expressed by a specific mimic behaviour,
suggest the behavioural dimension to be regarded as pain expression. Because of
the strictly orthogonal structure of the factor system, the circulatory and the
respiratory dimension lack any relationship to pain experience. In addition to
these statistical reasons, considerations on practicability disprove blood
pressure and respiratory rate as useful pain indicators: Whereas the observer
never failed to obtain a behavioural score, only 60% of the blood pressure
measures and 80% of the respiratory rates were valid. In contrast, heart rate
counts were obtained in over 99% and thus have to be considered as the only
practicable physiological measurement in the early postoperative period.
Corresponding to the results of the factor analysis, ROC curves suggest that the
ability of the heart rate alone to assess pain is not substantially better than a
random process, whereas the behavioural scale performs well. In addition the
heart rate failed to improve the accuracy of the behavioural scale as shown by
the results of a discriminant analysis. CONCLUSIONS: Despite the multidimensional
approach and the corresponding multivariate analyses, a unidimensional scale
consisting of behavioural items was found to be a valid indicator of an
postoperative analgesic demand. Due to the lack of diagnostic properties and
difficulties to obtain sound values even under research conditions, physiological
measurements like blood pressure, respiratory rate and heart rate are not
suitable for the assessment of a postoperative analgesic demand in infants,
neither for clinical nor for research purposes.
PMID- 10665311
TI - [Temporary adjustable defibrillator electrodes: an alternative method for the
treatment of postoperative arrhythmias after heart surgery].
AB - INTRODUCTION: Supraventricular and ventricular tachycardias are common and
serious postoperative complications early after cardiac surgery. We introduce a
new temporary adjustable defibrillation electrode (TADE) for internal low-energy
cardioversion/defibrillation of postoperative atrial and ventricular
tachyarrhythmias. METHODS: Evaluation of the new electrode was performed in ten
open-chest beagles with a mean weight of 25.5 kg. The electrodes were first
positioned on the left and right atrium. Atrial fibrillation (AU) was induced via
a bipolar temporary heart wire. Atrial defibrillation thresholds (DFT's) were
measured according to a step-down shock protocol (5 J-0.4 J). Thereafter, the
electrodes were adjusted and positioned on the right and left ventricle.
Ventricular fibrillation (VF) was induced and DFT's were recorded the same way.
RESULTS: For termination of AF, mean DFT's were 0.4 +/- 0 J (lowest possible
shock level) with a mean shock impedance of 70 +/- 7.6 omega. VF was terminated
with a mean DFT of 3 +/- 1.1 J with a mean impedance 56.1 +/- 7.9 omega. Complete
transcutaneous removal of the electrodes was possible in all animals without any
complications. CONCLUSION: Successful low-energy termination of AF and VF is
possible with the tested temporary adjustable electrode. A clinical study is
planned for further evaluation.
PMID- 10665312
TI - [Blood loss: physiologic adaptation mechanisms and therapeutic replacement].
PMID- 10665313
TI - [Significance of cellular hydration for cellular function].
PMID- 10665314
TI - Production of human albumin by plasma fractionation.
PMID- 10665315
TI - Yeast-derived recombinant human albumin (Recombumin).
PMID- 10665316
TI - Large scale production of RH-albumin expressed in the milk of transgenic cattle-
an economic and technical challenge.
PMID- 10665317
TI - [Human albumin--safety and tolerance].
PMID- 10665318
TI - [Natural and artificial colloids in children].
PMID- 10665319
TI - Use and abuse of albumin in clinical practice.
PMID- 10665320
TI - [Splenic rupture as a complication of ventilation in the prone position and
pneumococcal sepsis as a late complication].
AB - We are reporting the case of a female patient who had to undergo splenectomy
after she suffered splenic rupture as a result from "kinetic therapy" during the
treatment for pulmonary failure secondary to sepsis. Four years later the patient
was again admitted with a clinical picture consistent with sepsis. Two blood
cultures were positive for pneumococci confirming the diagnosis of pneumococcal
sepsis. This paper discusses the potential risks of kinetic therapy in patients
with ARDS. After splenectomy there is increased risk of infection with certain
bacteria, funghi, viruses and protozoa. The most common bacterial pathogen is
pneumococcus. A polyvalent vaccine is available for prophylaxis. Although
penicillin G is still commonly used as an antibiotic therapy for pneumococcal
infection, increased resistance of pathogens to penicillin must be anticipated.
Alternative antibiotic regimens are demonstrated.
PMID- 10665321
TI - [Quality of research in in university anesthesiology departments in Germany].
PMID- 10665322
TI - [MAPA (Ambulatory Measure of Blood Pressure), non-dippers, or which hypertensive
patients to treat?].
PMID- 10665323
TI - [Postoperative infections after heart surgery under extracorporeal circulation].
AB - Postoperative infection is still an important cause of mortality and morbidity
after cardiac surgery. The aim of this study was to assess its incidence and
causes in order to optimise treatment. Between January 1996 and December 1997,
1,000 consecutive patients (253 women and 747 men) were operated for cardiac
aortic pathology under cardiopulmonary bypass. The mean age was 66 +/- 11 years.
The initial pathology was coronary artery disease (N = 663), valvular heart
disease (N = 193), an association of the two (N = 94), thoracic aortic pathology
(N = 38) or other pathologies (N = 12). The global postoperative infection rate
was 4.9% (N = 49). The incidence of sternal and/or mediastinal infections was
0.7%, of bronchopneumonia 0.9%, urinary infection 2.1%, and septicaemia 1.7%.
Nine patients died of the consequences of an infection. The hospital stay was
significantly longer in infected patients, irrespective of the site of infection.
Statistical analysis of the whole population did not show any predictive factor
related to the preoperative clinical status of the patients. The only predictive
factor demonstrated was the day on which surgery was performed: the infection
rate in patients operated during the first 4 days of the week was 2.2% compared
with 7.3% for the patients operated during the last 3 days (p = 0.004, odds ratio
(OR) = 3.57). In those patients who had an urinary infection, the two identified
risk factors were the female gender (p = 0.006, OR = 3.34) and an operation
performed at the end of the week (p = 0.017, OR = 3.77). In patients with sternal
and medistinal infections, the only identified predictive factor was combined
coronary artery and valvular surgery (p = 0.009, OR = 7.43). With respect to
pulmonary infections, the only predictive factor was recent preoperative
myocardial infarction (< 1 month) (p = 0.004, OR = 7.5). Finally, no predictive
risk factors were identified in those patients who developed septicaemia. In
conclusion, this study showed that postoperative infection remains a serious
complication of cardiac surgery. The prevention of these complications should be
a priority for quality health care.
PMID- 10665324
TI - [AS heterozygote hemoglobinopathy and coronary risk].
AB - There have been several reports of vaso-occlusive events and sudden death in
subjects with sickle cell trait. However, the precise mechanism underlying these
episodes remains unclear. The clinical observations have been supported by in
vitro studies in which haemoglobin AS (Hb AS) red cells showed abnormalities of
their filterability, probably related to gelling or polymerisation of the Hb AS.
These in vitro studies and reports in the literature of sickle-cell hearts led
the authors to investigate the possible association between AS subject and
coronary risk. The results of coronary angiography in 9 patients with Hb AS,
paired with respect to the usual cardiovascular risk factors, were compared with
those of 18 AA subjects. The number of patients who underwent coronary bypass
surgery for three-vessel disease was much greater in the AS subjects. However,
the difference was not statistically significant. This tendency of AS subjects to
develop thrombosis and coronary artery disease requires further study with larger
numbers of patients.
PMID- 10665325
TI - [Implantable ventricular defibrillator. Systematic induction of ventricular
arrhythmia is not useful except for implantation].
AB - Checking the efficacy of a defibrillator after its implantation is current
practice. This control usually entails induction of ventricular fibrillation
(VF). The aim of this study was to assess the utility of this practice in
patients with an endovascular system of electrodes. Implantation was acquired
when a margin of security of 10 days or more had been obtained. During the
postoperative test, the choice of energy was that which reduced VF at
implantation. Of the 84 patients included in this study, 59 were implanted with
an endovascular electrode system alone and the other 25 patients had endovascular
electrodes associated with a subcutaneous patch electrode. The average time from
implantation to the postoperative test was 31 +/- 12 days. Arrhythmia sensing was
normal and reduction by the defibrillator was observed in all patients. The
average energy of the electric shocks was not significantly different to that
observed at implantation (18.6 +/- 3.6 J and 19.3 +/- 4.7 J). Fifty patients had
antiarrhythmic drugs (amiodarone = 43) at implantation, and 32 at the time of the
postoperative test (amiodarone = 17). This study showed that the postoperative
test with induction of VF was normal in all patients. Therefore, the authors
propose that follow-up should consist of consultation including interrogation of
the defibrillator and a chest X-ray to check the position of the electrodes. If
one of these tests is abnormal or if the perioperative threshold of
defibrillation does not provide an adequate margin of safety, induction of a
ventricular arrhythmia is necessary to check the function of the system.
PMID- 10665326
TI - [Hypertrophic obstructive cardiomyopathy and double-chamber pacing. Long-term
results in a consecutive series of 22 patients].
AB - The authors report their experience with dual-chamber pacing in hypertrophy
obstructive cardiomyopathy. 22 patients (14 women and 8 men) mean age 60 +/- 13
years were implanted between 1992 and 1998. The criteria for pace-maker
implantation were the presence of severe symptoms related with hypertrophy
obstructive cardiomyopathy (dyspnea, angina, syncope) and left ventricular
outflow tract gradient at mean 30 mmHg. Before pacing, all patients received a
medical therapy which included beta-blockers or calcium inhibitors. This
treatment was considered as ineffective or responsible of side effects. Patients
were followed-up at mean 35.1 +/- 20.3 months. During this period, symptoms
improved (mean NYHA class 2.7 +/- 0.5 before pacing vs 1.4 +/- 0.5 after pacing)
and left ventricular outflow tract lowered from 95.4 +/- 40.8 to 39.3 +/- 20.5 at
6 months. 34.3 +/- 23.4 at one year and 26.5 +/- 21 at the end of follow-up.
Seven patients had RF ablation of atrio-ventricular junction for paroxysmal
atrial fibrillation or for lack of hemodynamic improvement with pacing. This
procedure permits a significative lowering of gradient and a better ventricular
filling. In conclusion, dual-chamber pacing is effective for treatment of
hypertrophy obstructive cardiomyopathy when medical therapy is ineffective or bad
tolerated at condition of: perfect pacing with permanent ventricular capture and
optimal AV delay; RF ablation of AV junction in one third of cases; medical
therapy systematically associated in all patients.
PMID- 10665327
TI - [Abnormalities in the circadian rhythm of arterial blood pressure.
Physiopathological mechanism and clinical implications].
AB - A wide range of definitions is used to distinguish the hypertensives with a
blunted circadian pattern of blood pressure, labeled as "non dippers", from those
presenting with a normal night blood pressure fall, designated as "dippers".
Consequently the prevalence of non dipping phenomenon is quite uncertain: from 6
to 40% of the hypertensive subjects. The mechanisms of night blood pressure fall
remain unclear, but the involvement of autonomic nervous system turns out to be
partly demonstrated. From a clinical point of view, non dippers and dippers
characteristics are not obviously different, but the prognosis of non dipper
patients appears to be rather poor, with a more frequent target organ damage and
a higher rate of cardiovascular events, as compared to dippers, even in a general
population. In order to improve the identification of non dippers, an ambulatory
blood pressure monitoring should be performed in patients with autonomic nervous
system impairment and in subjects with target organ damage more severe than
expected from office or home blood pressure measurements.
PMID- 10665328
TI - Cardiac metabolism in ischemic heart disease.
AB - Myocardial ischemia is the metabolic consequence of an inadequate blood supply to
the myocardium. How does the myocardium survive a severe insult? Ischemia,
perhaps acting through hypoxia, is able to induce a series of cellular signals
that lead to protective genetic reprogramming. Metabolic self-protection includes
the new ischemic syndromes: stunning, hibernation and preconditioning. In every
case it should be considered that ischemia is basically a metabolic problem,
usually caused by coronary artery disease, stemming from lack of oxygen and blood
flow. In principle, besides revascularization, metabolic therapy should be
considered. In the past, metabolic therapies for effort angina have often been
ignored. A current hypothesis is that the ischemic myocardium benefits from a
switch from fatty acid to glucose metabolism. Two examples are (1) the
hemodynamically neutral antianginal agent, trimetazidine, and (2) intravenous
glucose-insulin-potassium (GIK). In acute myocardial infarction, GIK is
undergoing a resurgence of interest due to the promising results of the large
recent Argentinian trial. GIK acts in several ways, including the beneficial
effects of insulin itself upon reperfusion, promotion of glycolysis, and
inhibition of circulating fatty acids and hence of fatty acid oxidation.
Metabolic therapy acting to protect the ischemic cell deserves more attention.
PMID- 10665329
TI - [Congestive cardiomyopathies originating from arrhythmia].
AB - Arrhythmia-induced cardiomyopathy is partially or totally reversible left
ventricular dysfunction after normalisation of the tachycardia or arrhythmia. On
the one hand, there are pure forms in which the arrhythmia occurs in apparently
normal hearts and, on the other hand, the more common form in which there is
minimal underlying cardiac disease associated with the arrhythmia. Total or
partial recovery after reduction of the arrhythmia or "ablation" of its substrate
remains a key feature of the diagnosis. Many experimental studies of the
functional and structural myocardial and neurohormonal effects of prolonged
tachycardias or tachyarrhythmias have provided insight into the modes of
occurrence and the characteristics of this type of "reversible" left ventricular
dysfunction. But, in fact, there is a lack of anatomical, clinical and follow-up
data of this syndrome, the diagnosis of which is always difficult and essentially
retrospective after recovery of left ventricular function.
PMID- 10665330
TI - [Compression of the renal artery by a musculo-tendinous band: an unrecognised
cause of renovascular hypertension].
AB - Stenosis of a renal artery by extrinsic compression is an uncommon cause of
renovascular hypertension. In rare cases, this compression is due to the presence
of fibres from the diaphragm or the psoas muscle. This aetiology should be
considered when renal artery stenosis is observed in a young hypertensive patient
without cardiovascular risk factors. Spiral CT scan is particularly useful for
studying the relationship between the diaphragm and arterial structures. Once the
diagnosis has been made, the treatment is surgical section of the fibrous tissues
responsible for the compression.
PMID- 10665331
TI - [Troponins: new biochemical markers of myocardial damage. Structure, immunoassay
and clinical application].
AB - The development of immunoassay techniques has made it possible to use new
biochemical markers with a high myocardial specificity. Immunoassays have been
developed for two of the structural myocardial proteins: troponin I and troponin
T. The authors describe the biochemical properties of the troponins and the
available methods of immunoassay. The main clinical applications of troponin
measurement in cardiological practice are also reported.
PMID- 10665332
TI - [Pre-capillary pulmonary hypertension complicating CREST syndrome. Apropos of a
case].
AB - Pre-capillary pulmonary hypertension was the presenting sign of a CREST syndrome
in a 65 year old woman. The diagnosis of this form of scleroderma is based on the
association of a number of features (calcinosis, Raynaud's phenomenon,
oesophageal dyskinesia, sclerodactylia and telangectasia). Scleroderma is the
systemic disease which is usually complicated by pre-capillary pulmonary
hypertension. This complication is observed in about 13% of CREST syndromes, but
very rarely as severe pre-capillary pulmonary hypertension. The diagnosis of pre
capillary pulmonary hypertension carries a poor prognosis with a 2 year survival
rate of about 40%. Treatment is usually with calcium inhibitors but with no
effect on prognosis. The use of prostacycline and its analogue, iloprost, is an
interesting therapeutic strategy, currently under evaluation. Cardiopulmonary
transplantation is the only treatment of very severe forms, despite the
progressive character of the condition. All cases of pre-capillary pulmonary
hypertension require complete aetiological investigation to exclude a systemic
disease, especially a scleroderma and, above all, a CREST syndrome.
PMID- 10665333
TI - [Immediate collateral coronary circulation after a methylergometrin test].
AB - The development of a collateral coronary circulation has been well studied by
angiography in two main clinical situations: myocardial infarction (by durable
coronary occlusion) and angina (due to significant coronary artery stenosis), but
only rarely in spastic angina. The authors report the case of severe spasm at the
site of non-significant stenosis after a methylergometrine test, with immediate
contro-lateral collateral circulation in a patient with a short history of
spastic angina without myocardial infarction. This observation demonstrates that
collateral circulation may develop very rapidly in spastic angina (without basal
ischaemia in the absence of significant coronary stenosis), because this patient
only had seven ten-minute episodes of clinical ischaemia. As collateral
circulation may mask clinical and electrical signs in spastic angina, this case
suggests that angiographic control should be systematic during the
methylergometrine test.
PMID- 10665334
TI - [Pheochromocytoma simulating myocardial infarct. Apropos of a case].
AB - The authors report the case of a pheochromocytoma in a 67 year old man in whom
the initial clinical presentation suggested myocardial infarction.
Pheochromocytoma is usually an adrenal tumour with a very variable clinical
symptomatology. It is very rare for cardiac disease to be a presenting symptom.
The diagnosis was suggested by major blood pressure abnormalities occurring after
starting medical treatment for infarction. Pheochromocytomas may cause serious
cardiovascular disorders. The diagnosis must be suspected in the presence of
atypical signs, an essential requirement to reduce the mortality of the disease.
PMID- 10665335
TI - [Simultaneous utilization of an implantable automatic defibrillator in a patient
with previously implanted bi-ventricular pacemaker for end-stage heart failure].
AB - We report a case of implantable cardioverter defibrillator (ICD) use after
previous biventricular pacemaker insertion for end-stage heart failure. A 75-year
old man with inoperable three-vessel coronary artery disease, permanent atrial
fibrillation and end-stage heart failure underwent bi-ventricular pacemaker
insertion and His bundle ablation for symptomatic control. NYHA class decreased
from class III to II after this procedure. Four months after implant the patient
developed paroxysmal sustained, symptomatic ventricular tachycardia. ICD
implantation was undertaken. No potentially serious ICD-pacemaker interaction was
noted during subsequent follow-up. We conclude that ICD implantation is feasible
after previous bi-ventricular pacemaker insertion, without the need to explant
the bi-ventricular pacing device.
PMID- 10665336
TI - Human obesity and thinness, hyperlipidemia, hyperglycemia, and insulin resistance
associated with HIV1 protease inhibitors. Prevention by alternating several
antiproteases in short sequences.
AB - In 1997, and mainly in 1998 and 1999, a lipodystrophic syndrome with central
obesity, peripheral fat loss, hyperlipidemia, hyperglycemia and insulin-resistant
diabetes II, was described as the most frequent manifestation of toxicity of HIV1
virostatic therapy, associated with protease inhibitors (PI) in 83% of the
patients who used them for 10 months. Almost similar syndromes had been published
before the latter, due, for example, to graft vs host reaction, or autoimmunity
against insulin receptors, or to caloric excess in the presence of androgens (the
mediator being hyperinsulinemia). Carr and Cooper have presented an original
pathophysiological mechanism for the PI-associated syndrome, residing in 63%
homology between HIV1-protease and the 3-low-density-lipoprotein-receptor-related
protein (LRP), and in 53% homology between this virus enzyme and retinoid-binding
protein type 1 (CRAB1). The treatment should be more subtle than those of common
obesity and/or type II diabetes. This HIV1-protease inhibitor toxicity can be
prevented by alternating several antiproteases in short sequences of the
different ones.
PMID- 10665337
TI - Prader-Willi syndrome, diabetes mellitus and hypogonadism.
AB - Diabetes mellitus is not a diagnostic criterion for Prader-Willi syndrome (PWS),
but it is often found in PWS patients. The etiology for diabetes mellitus in PWS
may be related to the morbid obesity and consequent insulin resistance, because a
decrease of oxytocin neurons and leptin resistance in PWS may cause hyperphagia,
inducing obesity. However, treatment with growth hormone (GH) is beneficial for
the majority of GH-deficient PWS children, because relative decreased fat mass
and increased fat-free mass could prevent obesity and concomitant insulin
resistance. Hypogonadism is thought to be due to hypogonadotrophic hypogonadism
in a majority of PWS patients. Hypergonadotrophic hypogonadism secondary to
cryptorchidism and its treatment is shown in other cases. Low luteinizing hormone
and high follicle-stimulating hormone levels in PWS cases in young men with
idiopathic oligospermia or in the early stages of puberty is less frequently
reported.
PMID- 10665338
TI - Plasma plasminogen activator inhibitor 1, insulin resistance and android obesity.
AB - Plasma plasminogen activator inhibitor 1 (PAI-1) levels are elevated in insulin
resistant subjects and are associated with increased cardiovascular risk of
atherothrombosis. Strong association between PAI-1 and the metabolic components
of the insulin resistance syndrome is found in clinical studies, suggesting that
insulin resistance may regulate circulating PAI-1. However, the mechanisms
underlying increased PAI-1 levels in such conditions are still poorly understood.
Several studies have been carried out specifically in patients with central or
android obesity, a major characteristic of the insulin resistance syndrome, and
have suggested that visceral adipose tissue may be the major component of the
relationship between android obesity and PAI-1. Accordingly, adipose tissue PAI-1
production was found to be elevated in obese human subjects, particularly in
visceral adipose tissue. The genetic background for having high PAI-1 levels in
several populations have been looked for and its role appeared to be weaker than
that of the metabolic condition. High plasma PAI-1 levels are then clearly
related to android obesity and insulin resistance, but the mechanisms whereby PAI
1 increases in plasma in these diseases remain to be determined.
PMID- 10665339
TI - Lipoprotein (a) in android obesity and NIDDM: a new member in 'the metabolic
syndrome'.
AB - The 'metabolic syndrome' is a special clinical entity characterized by upper body
segment obesity (android obesity), together with one or more of a constellation
of metabolic disorders that includes glucose intolerance, which may amount to
frank diabetes mellitus, hypertension, cardiovascular lesions, hyperuricemia, and
dyslipidemias (hypercholesterolemia, hypertriglyceridemia and reduced serum HDL).
Recently, lipoprotein (Lp) (a) proved to be a new member in this syndrome. Lp(a)
has the distinctive feature of containing apolipoprotein (a), which is a
glycoprotein linked to apo B100, and has a similarity to plasminogen; it is also
structurally related to LDL. Lp(a) is a macromolecular complex which is
genetically determined, and has been identified as an independent risk factor for
premature coronary artery disease (CAD). It is elevated in diabetic and non
diabetic android obese subjects, and aggravates the atherogenic effect of
diabetes mellitus. Lp(a) is poorly influenced either by dietary measures or by
hypolipidemic drugs. Unfortunately, few pharmacologic agents, such as niacin,
nicotinic acid, sex hormones (estrogen and testosterone), alcohol and neomycin,
affect Lp(a).
PMID- 10665340
TI - Role of protein tyrosine phosphatase-1B in diabetes and obesity.
AB - Type 2 or non-insulin-dependent diabetes mellitus (NIDDM) is reaching epidemic
proportions in industrialized countries. Obesity is a major factor in this
disease, since about 75% of obese individuals will develop type 2 diabetes. There
is an urgent need to develop new therapies for these diseases. Recently, the
protein tyrosine phosphatase PTP-1B has been shown to be a negative regulator of
the insulin signaling pathway, suggesting that inhibitors of this enzyme may be
beneficial in the treatment of type 2 diabetes. Mice lacking PTP-1B are resistant
to both diabetes and obesity.
PMID- 10665341
TI - In-vivo delivery of therapeutic proteins by genetically-modified cells:
comparison of organoids and human serum albumin alginate-coated beads.
AB - We have designed a self-assembling multimeric soluble CD4 molecule by inserting
the C-terminal fragment of the alpha chain of human C4-binding protein (C4bp
alpha) at the C-terminal end of human soluble CD4 genes. This CD4-C4bp alpha
fusion protein (sMulti-CD4) and two other reference molecules, a fusion protein
of human serum albumin (HSA) and the first two domains of CD4 (HSA-CD4) and
monomeric soluble CD4 (sMono-CD4), were delivered in vivo by genetically modified
293 cells. These cells were implanted in mice as organoids and also encapsulated
in HSA alginate-coated beads. sMulti-CD4 showed an apparent molecular weight of
about 300-350 kDa, in accordance with a possible heptamer formula. sMulti-CD4
produced either in cell culture or in vivo in mice appeared to be a better
invitro inhibitor of HIV infection than sMono-CD4. Plasma levels of sMulti-CD4,
HSA-CD4, and sMono-CD4 reached approximately 2,300, 2,700, and 170 ng/mL,
respectively, 13 weeks after in-vivo organoid implantation, which had formed
tumours at that time. This suggests that the plasma half-life of sMulti-CD4 is
much longer than that of sMono-CD4. The 293 xenogeneic cells encapsulated in HSA
alginate-coated beads remained alive and kept secreting sMono-CD4 or HSA-CD4
continuously at significant levels for 18 weeks in nude mice, without tumour
formation. When implanted in immunocompetent Balb/c mice, they were rejected two
to three weeks after implantation. In contrast, encapsulated BL4 hybridoma cells
remained alive and kept secreting BL4 anti-CD4 mAb for at least four weeks in
Balb/c mice. These results suggest the clinical potential of the C4bp
multimerizing system, which could improve both the biological activity and the
poor in-vivo pharmacokinetic performance of a monomeric functional protein like
soluble CD4. These data also show that a systemic delivery of therapeutic
proteins, including immunoglobulins, can be obtained by the in-vivo implantation
of engineered allogeneic cells encapsulated in HSA alginate-coated beads.
PMID- 10665342
TI - Why have ten or so nontoxic, retrovirus integrase inhibitors not been made
available for AIDS treatment? A ten-year experience [correction of experiment]
must liberate them.
AB - We detected in 1989, with the inhibitor test of proviral insertion into c-erb B
erythroblastosis, two retrovirus integrase inhibitors: hydroxy-methyl-ellipticine
and acriflavine. They have been used for ten years in AIDS patients with high
efficacy and no toxicity. Since vitamin B12 and cobalt, which it contains, have
been detected as HIV1-integrase inhibitors by an in-vitro test, we have also used
vitamin B12 (combined with folic acid), whose clinical action has been
remarkable. Ten or so other compounds have been detected by such in-vitro tests,
among which there are many compounds (such as flavones) which are used in many
conditions and are not toxic.
PMID- 10665343
TI - Pediatric extracranial applications of MR angiography.
AB - Extracranial magnetic resonance angiography (MRA) was performed in 20 children to
evaluate for various arterial and venous conditions. Time-of-flight and phase
contrast angiograms were constructed using a maximal-intensity-projection
algorithm. The accuracy of MRA was comparable to Doppler ultrasound (n = 12) and
conventional angiography (n = 3). MRA could provide an excellent mapping of
patent (including collaterals) versus thrombosed vessels at sites not evaluated
or inaccessible by sonography. Limitations included assessment of small and/or
tortuous vessels, severely stenotic lesions, and very slow flow.
PMID- 10665344
TI - Significance of resistive index in color Doppler ultrasonogram: differentiation
between benign and malignant breast masses.
AB - The objective of this article is to evaluate the significance of resistive index
in differentiation between benign and malignant breast lesions on duplex
ultrasonographic examination. Resistive indices obtained in 106 breast lesions of
104 patients were included. Sixty-four were benign (mean age: 32.4 +/- 11.1
years), and 42 were malignant lesions (mean age: 47.8 +/- 11.4 years). The
resistive index was classified as follows: below 0.49, from 0.5 to 0.59, 0.6 to
0.69, 0.7 to 0.79, and above 0.8. We analyzed and defined the optimal threshold
value of RI between benign and malignant lesions. The mean values of the RI of
benign and malignant lesions were 0.62 +/- 0.095 (range 0.44-0.86) and 0.74 +/-
0.097 (range, 0.50-0.92), respectively. The resistive index exceeded 0.7 in 80%
of malignant lesions. The difference of the RI between malignant and benign
lesions was statistically significant when the threshold value was 0.7 (P <
0.001). A resistive index over 0.7 may suggest malignant lesions. Due to the
considerable overlap of the range of the RI, it may not be diagnostic in any
single patient; however, it may be helpful in conjunct with gray-scale image.
PMID- 10665345
TI - Atypical presentation of dissection of the ascending aorta in young men with
cystic medial necrosis: MR findings.
AB - Dissection of the ascending aorta is usually associated with severe chest and/or
back pain. We describe three young men, with pathologically proven cystic medial
necrosis, who presented with atypical clinical symptoms and ascending aortic
dissection diagnosed by MR imaging and surgery. Patients with cystic medial
necrosis and aortic dissection may not present with a classic acute chest pain
syndrome.
PMID- 10665346
TI - Gastrocolic fistula due to adenocarcinoma of the colon: simulation of primary
gastric leiomyosarcoma on CT.
AB - This article describes the CT findings in two patients with adenocarcinoma of the
colon and gastrocolic fistula which simulated the classic appearance of gastric
leiomyosarcoma on CT. The role of CT in the diagnosis of gastrocolic fistula is
also discussed.
PMID- 10665347
TI - Rapidly and infiltratively growing Crohn's carcinoma of the small bowel: serial
radiologic findings and a review of the literature.
AB - We carried out a retrospective evaluation of serial changes in the small bowel
radiographs of a patient with small bowel cancer accompanied by long-standing
Crohn's disease. During the 8 months before diagnosis, marked morphological
changes were noted. A solitary and irregular protrusion, and rapidly growing
stricture under careful medical management of the underlying disease may indicate
the development of cancer.
PMID- 10665348
TI - Contrast-enhanced hepatic MRI: comparison of half-dose and standard-dose
gadolinium DTPA administration in lesion characterization with T1-weighted
gradient echo sequences.
AB - The objective of this article was to compare half-dose (0.05 mm/kg) gadolinium
enhanced dynamic hepatic MR imaging to standard doses (0.10 mm/kg). Eighteen
patients for follow-up hepatic MR received 0.05 mm/kg of gadolinium DTPA
dynamically with gradient-echo imaging. Imaging parameters were identical to a
0.10-mm/kg study; patients were imaged during multiple phases of contrast
enhancement. Two readers assessed for enhancement patterns and characterization.
Quantitative signal-to-noise ratios (S/N) were obtained for abdominal viscera and
contrast-to-noise ratios (C/N) were obtained on up to three lesions. No
significant difference for the arterial dominant phase (P > 0.05) was found.
Significant differences were found in all categories during the portal venous
phase (except pancreas) and equilibrium phase (except liver). Lesion C/N ratios
were not significant at any point (P > 0.05). Sixty-two out of 64 lesions (97%)
were identically characterized. Therefore, half-dose dynamic gadolinium-enhanced
MR may have diagnostic value.
PMID- 10665349
TI - Association of posterior rib fractures with exaggerated kyphosis and sternal
collapse.
AB - The ribs, sternum, and vertebrae all play an important role in stabilizing the
thorax. Failure of one of these components places additional stress on the other
supporting structures. We present a case of a 62-year-old man with multiple
myeloma and osteopenia who sustained fractures to all three components.
PMID- 10665350
TI - Avascular necrosis of bone in human immunodeficiency virus infected patients.
AB - The objective of this article was to delineate the causes of avascular necrosis
(AVN) in patients with human immunodeficiency virus (HIV). HIV-infected patients
with pain in large joints were prospectively screened. Patients had radiographs
and magnetic resonance imaging of their affected joints. Serum lipids,
anticardiolipin antibody levels (IgG, IgM), and hemoglobin electrophoresis were
performed on all patients who had radiographic studies. Medical records were
screened for factors known to predispose for AVN. Eight patients completed the
protocol, and five patients had AVN in seven joints. No common laboratory
abnormality was identified in the patients with AVN. All of the patients with AVN
had a history of steroid use; four of five patients having taken steroids for HIV
related diseases. The cause of AVN does not appear to be directly related to the
disease, but to steroid treatment for manifestations of the disease.
PMID- 10665351
TI - Water-suppression MRI: role in the evaluation of osseous lesions.
AB - The efficacy of chemical shift based water-suppression MRI in the evaluation of
bone marrow lesions has not been previously reported. T1-weighted images without
and with water suppression were compared in five patients with 16 lesions. There
was a significant improvement in the contrast-to-noise ratio (from 4.32 to 5.95,
P < 0.01) and contrast ratio (from 1.71 to 5.69, P < 0.004) with water
suppression. Water suppression may be useful clinically by increasing the
conspicuity of bone marrow lesions.
PMID- 10665352
TI - Current status of burn resuscitation.
AB - Rapid assessment and management of airway and breathing problems are required in
the patient with severe burns complicated by significant facial burns and
inhalation injury. A policy that results in intubation of all patients at
potential risk for airway compromise can be both foolish and dangerous. At the
same time, it is recognized that intubation of patients who are likely to develop
unstable airways is necessary if transport times to burn centers are long and if
i.v. resuscitation is initiated during transport. The ideal burn resuscitation
formula does not exist. Whichever formula is used, patients must be monitored
closely and the fluid resuscitation individualized according to their responses.
Patients with delay in resuscitation, associated trauma, inhalation injury, or
alcohol abuse may require fluid resuscitations greater than those predicted. The
goal is to maintain urine outputs in the range of 0.5 to 1 mL/kg/hr for adults
and 1 to 1.5 mL/kg/hr in children. In patients with fluid requirements greater
than 150% of that predicted by formula, the addition of colloid at 12 hours can
reduce total fluid requirements and burn edema. Early placement of pulmonary
artery catheters can be useful in patients with known myocardial dysfunction, age
greater than 65 years, severe inhalation injury, or fluid requirements greater
than 150% of that predicted by formula.
PMID- 10665353
TI - Current status of burn wound pathophysiology.
AB - Healing is a continuum that can be unpredictable. Despite many advances and
understanding of the multiple cellular processes and molecules involved in burn
wound healing, physicians and patients have yet to reap the full benefit of this
knowledge. The advances have occurred in a very short period, and with the
exponential growth of molecular biology techniques and transgenic animal models,
our understanding and treatment of burn wound healing could change exponentially
over the next 10 years. The goal must be to continue to improve functional
outcomes for burn survivors just as we have conquered critical care management
for acutely injured burn patients.
PMID- 10665354
TI - Primary excision of the burn wound.
AB - Early excision of burn eschar and wound closure significantly improves survival
following major burn injury. Immediate primary excision performed by burn
experienced surgeons in dedicated burn care facilities can reduce further
morbidity and mortality, length of hospital stay and medical costs. Burn care at
the millennium is evolving rapidly into a subcategory of trauma surgery, with
burn patients increasingly being viewed as victims of major trauma who benefit
most from immediate and definitive surgical correction of their injuries.
PMID- 10665355
TI - The acute and subacute management of the burned hand.
AB - Management of the severely burned upper extremity remains a significant challenge
to the most experienced clinician. An understanding of the underlying mechanism
that uncorrected could culminate in a negative outcome is the key to formulation
of a successful treatment plan. Initial proper splinting, avoidance of edema, the
appropriate sequencing and integration of physical therapy, and judicious
surgical intervention, all considered within the framework of the individual
patient, are the components of the treatment plan that yields the most
consistently good results.
PMID- 10665356
TI - Reconstruction of the burned hand.
AB - There is no "cookbook" for reconstructing the burned hand. Multiple issues can
color the chances for a successful outcome. What is the endpoint of surgical
effort? Is it when the patient tires, becomes discouraged, or ceases to return?
These questions are not rhetorical. Whereas an appendectomy cures appendicitis,
no single surgical procedure or series of procedures cures burns. Many patients
spend their lives searching to be as they were preinjury. Although physicians as
healers do not want to destroy hope, ethics command that we attempt to keep these
patients focused on reality. Although there is always something that could be
done, judgment dictates what should be done. The major goals are early
independence and resumption of preburn lifestyle for the patient. A thoughtful
surgical plan set up in conjunction with the burn team and with timed goals gives
the patient the best chance for success.
PMID- 10665358
TI - Acute and reconstructive management of the burned eyelid.
AB - Introduced in 1875, the use of full-thickness skin graft for release of a lower
eyelid ectropion secondary to burn contractures remains a mainstay of current
burn treatment. The authors address issues such as acute care, the exposed
cornea, scar management, and surgical management of eyelid deformities.
PMID- 10665357
TI - Splints and scar management for acute and reconstructive burn care.
AB - Because patients assume a position of comfort during acute burn management,
affected joints or regions must be splinted in positions of function to avoid
contractures. Particularly with the increasing trend towards ambulatory burn
care, close monitoring by the burn team and patient education is required to
achieve the best functional result. Despite adequate initial care, contractures
sometimes occur, requiring a shift in splinting tactics to correct the deformity.
If secondary reconstruction is required, the affected region is once again
maintained in the position of function. Although the physiologic mechanism is
incompletely defined, pressure therapy to prevent and treat hypertrophic burn
scars is an integral component of burn care. Multiple materials and methods are
available with treatment, starting soon after burn wound closure, and modified as
needed until scar maturation has occurred.
PMID- 10665359
TI - Reconstruction of the burned nose and ear.
AB - Patients who have survived thermal injuries to the face suffer from severe
disfigurement. When the nose and ear are involved, the resulting deformities are
immediately obvious to all who see the patient. This level of injury results in a
self-imposed confinement; the patients never leave their homes. It is therefore
important that we plastic surgeons know, understand, and use all options
available to improve our patients' appearance and ultimately their mental and
physical well being.
PMID- 10665360
TI - Reconstruction of the burned breast.
AB - Fundamental principles of management of breast burns begin with recognition and
preservation of any viable breast bud tissue. Reconstruction begins when the
burned breast envelope is insufficient to allow unrestricted breast development.
Complete contracture release is obtained by incision or excision of the
restricting burn scar and thick split-thickness grafting. Occasionally, breast
mound reconstruction with regional musculocutaneous flaps or tissue expanders is
necessary. Balancing procedures, such as reduction or mastopexy of an opposite
unburned breast, are often helpful. After a period of 6 to 12 months of
compression garments, scar management, and settling, nipple-areola reconstruction
is undertaken and consists of a combination of local flaps, full-thickness
grafting, or composite grafts tailored to each patient's needs. Long-term follow
up is necessary to ensure that breast development continues satisfactorily and
that contractures do not recur.
PMID- 10665361
TI - Tissue expansion in head and neck burn reconstruction.
AB - The advent of tissue expansion has provided a useful tool for the reconstructive
burn surgeon. As with many new techniques, there was an initial wave of
enthusiasm surrounding the introduction of tissue expansion to burn
reconstruction in the 1980s. High complication rates and many dissatisfying
results followed. After early widespread use of tissue expansion, the authors
have settled on a more refined approach to the reconstruction of head, neck, and
facial burns. Today, head and neck burn reconstruction is accomplished best with
a combination of skin grafting, local flaps, and occasional free flaps in
addition to tissue expansion. In carefully selected head and neck burn patients
and in many burn alopecia patients, tissue expansion can provide excellent
functional and aesthetic results, with minimal donor site morbidity.
PMID- 10665362
TI - Electrical burns.
AB - Electrical burns can be divided into flash or typical thermal injury and high
tension injury. The latter is usually caused by greater than 1000 volts and
produces a clinically characteristic entry and exit wound. The optimal management
of patients with high-tension electrical injury has evolved into a plan of urgent
exploration and debridement, aggressive redebridement, and early wound closure.
PMID- 10665363
TI - Reconstruction of the burned foot.
AB - Burns of the feet pose unique and difficult problems in initial management,
reconstruction, and the attainment of long-term functional results. The primary
reconstructive goals for this region are unimpeded ambulation and weightbearing
on a pain-free limb. These objectives can be achieved by adherence to established
principles of wound management, a clear delineation of the reconstructive
requirements of the foot, and a team approach toward attaining these goals. The
goal of any method of reconstruction should be the restoration of function within
a reasonable aesthetic appearance. With the foot, in addition to adequate
healing, the goal should be the ability to walk again, wear normal footwear, and,
if possible, return to work.
PMID- 10665364
TI - A simple procedure for polymerase chain reaction of the PSBA gene in algae:
application to the screening of mutations conferring atrazine resistance and
discrimination of natural populations of Porphyra linearis.
AB - A simplified procedure is described for polymerase chain reaction (PCR) of a
partial sequence (bp 601-893) of the plastid gene psbA in the rhodophyte Porphyra
linearis and the diatoms Haslea ostreria and Skeletonema costatum. This procedure
involves the use of all tissues of P. linearis and live cell suspensions of H.
ostreria or S. costatum, as DNA templates, without any further purification of
DNA. As in the case of PCR with DNA extracts, a single major band of the expected
size (292 bp) was obtained after PCR for the three species. Sequences of the
amplified fragments were aligned, confirming that the amplified products were
part of the psbA gene. The method was then used to screen mutations in partial
psbA genes of 23 samples of P. linearis collected at four different stations
along the mid-Atlantic coast of France. An alignment was obtained indicating the
existence of mutations, though not in codons known for herbicide resistance. All
mutations found were silent. However, genetic polymorphism discriminated between
samples collected from two stations. The method employed allows rapid
amplification of the herbicide target gene and simplifies the procedure for
screening mutations or populations in algae. Its application to other genes and
species is considered.
PMID- 10665365
TI - Effect of turkey (Meleagridis gallopavo) breeder hen age and egg size on poult
development. 1. Intestinal growth and glucose tolerance of the turkey poult.
AB - Three experiments were conducted to determine if turkey (Meleagridis gallopavo)
hen age and egg weight affect poult intestinal development and glucose tolerance
during the first week after hatching. Differences in glucose tolerance were not
consistent across the experiments. In experiment 1, 4-day-old poults from the
younger hens and lightest egg weight class had significantly greater fasting
plasma glucose concentrations (P < 0.04) and were also higher at 30 and 60 min
post-injection of 250 mg glucose. In experiment 2, egg weight class had no
significant effects on plasma glucose concentrations of 4-day-old poults (after
injection of 2.5 mg glucose/g body weight). In experiment 3, plasma glucose
concentrations were not different between groups at 0 or 30 min post-injection
(3.75 mg glucose/g body weight), however, poults from the younger hens had 79-90
mg/dl higher plasma glucose concentrations 60 min post-injection versus poults
from the older hens. Neither egg weight class or hen age consistently affected
small intestinal weight, length, or density (g/cm) measures across experiments.
PMID- 10665366
TI - Effect of turkey (Meleagridis gallopavo) breeder hen age and egg size on poult
development. 2. Intestinal villus growth, enterocyte migration and proliferation
of the turkey poult.
AB - Villus growth, enterocyte migration and proliferation were measured in the small
intestine of poults (Meleagridis gallopavo) to determine if hen age and/or egg
size influences these characteristics during the first week after hatching. At
hatching, distal jejunal villi were 22.8 microns longer in poults from the older
(48 weeks) versus the younger (34 weeks) hens (P < 0.05). Similarly, labeled
enterocytes in distal jejunal sections from poults from the older hens had
migrated 28 microns (10%) farther along the crypt-villus axis at hatching, as
compared to poults from the younger hens (P < 0.05). Villus growth differences
and enterocyte migration were not consistently affected by hen age or egg weight
class in poults from 1 to 7 days old. These results suggest that even though
intestinal villi may be more advanced developmentally at hatch in poults from the
older hens, however post-hatch growth of the intestine or the poult is not
affected by hen age or egg weight class.
PMID- 10665367
TI - Serum alpha- and gamma-tocopherols, retinol, retinyl palmitate, and carotenoid
concentrations in captive and free-ranging bottlenose dolphins (Tursiops
truncatus).
AB - Concentrations of retinol, retinyl palmitate, beta-carotene, alpha-carotene,
cryptoxanthin, lutein, lycopene, alpha-tocopherol, and gamma-tocopherol were
measured in blood samples collected from 15 captive and 55 free-ranging
bottlenose dolphins (Tursiops truncatus). From June 1991 to June 1994, blood
samples were collected from captive animals residing at two locations; at Seven
Seas (Brookfield Zoo, Brookfield, IL) and Hawk's Cay (Marathon Key, FL). Blood
samples were collected from free-ranging animals from June 1991 to June 1996.
Retinol levels were not significantly different between captive dolphin groups.
However, Seven Seas animals had higher (P < 0.01) serum retinol concentrations
compared to free-ranging animals (0.061 vs 0.041 microgram/ml). Retinyl palmitate
was not detected in the serum of captive or free-ranging dolphins. Alpha
tocopherol levels were significantly (P < 0.05) higher for Seven Seas dolphins
(16.4 micrograms/ml) than for Hawk's Cay (13.0 micrograms/ml) and free-ranging
dolphins (12.5 micrograms/ml). Gamma-tocopherol concentrations were similar among
captive and free-ranging dolphins. Free-ranging dolphins showed levels of
circulating carotenoids (lutein and beta-carotene) while the captive animals did
not. Additional carotenoids (lycopene, alpha-carotene and cryptoxanthin) were
analyzed but not detected in any samples. Serum vitamin differences between
captive and free-ranging dolphins may reflect the natural diet or indicate some
potential biological or nutritional status significance.
PMID- 10665368
TI - Comparison of phosphodiesterase isozymes in rodent parotid glands.
AB - We investigated phosphodiesterase (PDE) isozymes, which hydrolyze cAMP, in rodent
parotid glands (mouse, hamster and guinea pig) in order to clarify the effects of
cGMP and Ca/calmodulin on the regulation of cellular cAMP and compared them with
those of the rat. More than 80% of the activities were in the supernatant
fractions except for the hamster. The isozymes were fractionated using Mono Q ion
exchange column. The mouse parotid PDEs consisted of PDE1 (Ca/calmodulin
dependent), PDE2 (cGMP-stimulated), PDE3 (cGMP-inhibited) and PDE4 (cAMP
specific) similar to those of the rat. PDE3 was not detected in the hamster, and
PDE4 was not detected in the guinea pig. PDE activities in the supernatant of the
mouse and the hamster were stimulated by cGMP, and that of the guinea pig was
stimulated by Ca/calmodulin. These results suggest that various PDE isozymes are
present in the parotid gland of several species of order Rodentia. There seems to
be differences among the species with regard to the PDE isozymes.
PMID- 10665369
TI - Influence of dietary protein on insulin-like growth factor binding proteins in
the chicken.
AB - We determined the effect of dietary protein on the distribution of insulin-like
growth factor (IGF) binding proteins in chicken plasma. Three groups of male
broilers (n = 6 per group) were fed (ad libitum) isocaloric diets containing 12,
21 or 30% dietary protein. Birds were fed respective diets beginning at 7 days of
age and killed at 28 days. No differences were observed between adequate (21%)
and high (30%) protein intakes for any of the parameters investigated (growth
criteria, plasma levels of IGF-I, growth hormone or IGF-binding proteins).
Feeding protein deficient diets (12%) resulted in a 34% decrease in body weight,
17% decrease in feed intake and a 39% increase in feed/gain ratio. IGF-binding
proteins in plasma samples were separated by SDS-PAGE and transferred to
nitrocellulose sheets. Nitrocellulose blots were probed with [125I]chicken IGF
II. Four regions of binding activity corresponding to 70, 43, 30 and 24 kDa were
observed in all samples. Birds consuming 12% dietary group protein had less than
50% of the 43-kDa binding activity of birds consuming 21 or 30% dietary protein.
The 30-kDa binding activity was 42% lower in the 12% dietary protein group
compared to birds consuming adequate protein. In contrast, 70- and 24-kDa binding
activities were not influenced by dietary protein. Chickens consuming 12% dietary
protein had higher levels of growth hormone and lower levels of IGF-I than those
consuming 21 or 30% dietary protein. These data indicate that in chickens, the
circulating levels of at least two independent IGF-binding proteins are
influenced by dietary protein.
PMID- 10665370
TI - The effect of urea exposure on isoaspartyl content and protein L-isoaspartate
methyltransferase activity in Drosophila melanogaster.
AB - Urea is a protein unfolding agent that can accumulate to locally high
concentrations in tissues of many organisms. We used Drosophila melanogaster to
test the hypothesis that urea loading would promote formation of isoaspartate
(beta-carboxyl-linked aspartate), a common form of protein damage that occurs
most readily in unstructured polypeptides and flexible regions of folded
proteins. Ten populations of flies were tested; five control populations of urea
sensitive flies and five previously selected urea-tolerant populations. We
measured the effects of urea consumption on levels of both isoaspartate and
protein L-isoaspartate methyltransferase (PIMT), an enzyme believed to function
in the repair or removal of isoaspartyl proteins. For both sets of populations,
urea feeding for 6 days increased isoaspartyl levels by approximately 60%,
supporting the idea that disruption of protein secondary and tertiary structures
can accelerate the formation of isoaspartate in vivo. Urea feeding tended to
increase PIMT activity in both control and urea-tolerant populations. There were
no significant differences in PIMT activities or isoaspartyl levels between the
control and urea-tolerant flies raised on normal or urea food. The latter
findings indicate that urea tolerance evolved in the selected populations without
any significant change in PIMT expression or activity.
PMID- 10665371
TI - Molecular cloning, sequence analysis and expression distribution of an
aminopeptidase in Aplysia california.
AB - We are investigating the role of membrane-bound peptidases in the inactivation of
neuropeptides in Aplysia californica. Recently, we reported the biochemical
characterization of a membrane-bound neuropeptide-degrading enzyme which has
enzymatic characteristics similar to those of the mammalian aminopeptidase N
(Bawab W, Querido E, Crine P, DesGroseillers L. Identification and
characterization of aminopeptidases from Aplysia californica, Biochem J
1992;286:967-975). We now report the cloning and sequencing of a cDNA encoding an
aminopeptidase enzyme (apAP) and the localization of the apAP transcript in
Aplysia. The apAP cDNA encodes a putative protein of 1007 amino acids, which
shows around 34% sequence identity to mammalian aminopeptidases A and N
sequences. The deduced amino acid sequence suggests that apAP is a type II
membrane-bound protein, with a long extracellular domain in which the consensus
sequence of zinc-binding metallopeptidases (His-Glu-Xxx-Xxx-His) is found. RT-PCR
and Northern blot experiments showed that the apAP gene is expressed as a single
6.8-kb transcript in the central nervous system, gill, heart, kidney and
ovotestis.
PMID- 10665372
TI - Comparative study on the fatty acid composition of two marine vertebrates:
striped dolphins and loggerhead turtles.
AB - The fatty acid composition of total lipids extracted from seven different tissues
(fat, liver, cerebrum, cerebellum, lung, kidney and muscle) of 10 striped
dolphins (Stenella coeruleoalba) (weight 75.7 +/- 16.2 kg) found dead or moribund
during a morbillivirus epizootic, and from two tissues (fat and liver) of 54
loggerhead turtles (Caretta caretta) (18.5 +/- 10.5 kg) seized dead after illegal
capture, both from the Mediterranean Sea, have been determined by high resolution
chromatography techniques. When comparing both species, fatty acid composition is
surprisingly similar, with a predominance of the monoenoic followed by the
saturated group of fatty acids, and a very close ratio of polyunsaturates n-3/n
6. The relatively high arachidonic acid content in the liver of the two marine
species is remarkable. The similar diet can play an important role in these
findings, but it is suggested that probably metabolic pathways and essential
fatty acid requirements between both marine vertebrates are similar, more than is
expected from their earlier filogenetic evolutionary divergence.
PMID- 10665373
TI - Thyroid hormones regulate lipid metabolism in a teleost Anabas testudineus
(Bloch).
AB - We compared the long-term action of 3,5,3'-triiodo-L-thyronine (T3) and 3,5
diiodo-L-thyronine (T2) on lipid metabolism in a teleost Anabas testudineus.
Among the six groups of animals used in this experiment, except for the control
group, all received 6-propylthiouracil (6-PTU) to create a hypothyroid state in
order to analyse the action of iodothyronines on lipid metabolism. Injections of
6-PTU reduced T3 concentration in the circulation by 79.6% and injections of
iodothyronines enhanced the level of T3 in the plasma, and a maximum increase was
observed in T3 (500 ng)-treated specimens. Analysis of lipogenic enzymes in liver
and heart showed that a tissue-specific variation exists in the action of thyroid
hormones and, in many cases, activity is higher in T2-treated groups. Analysis of
various lipid classes showed that long-term administration of T2 is also
effective in producing a comparable effect with that of T3 on lipid metabolism.
PMID- 10665374
TI - Modulation of reduction of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone by
vitamin C-palmitate.
AB - An in vitro study of effects of vitamin C-palmitate on the metabolism of 4
(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in rat microsomes was
performed. A sensitive assay method has been developed for the detection of
metabolites of NNK in microsomes. Only the reduced metabolite of NNK, 4
(methylnitrosamino)-1-(3-pyridyl)-butanol (NNAL), was detected and measured in a
time-course study. Vitamin C-palmitate enhanced the reduction of NNK in a
concentration-dependent manner. The results indicate a significant increase in
Vmax and K(m) in the presence of vitamin C. However, the rate of formation of
NNAL at low substrate concentration varied. The ratio of Vmax to K(m) decreases.
The results suggest that the kinetics are accounted for best by an uncompetitive
activator binding model at low concentration of vitamin C. The uncompetitive
binding model becomes sketchy at higher concentration of vitamin C. These
observations infer that vitamin C loosely binds to the substrate-enzyme complex.
Furthermore, the nature of the binding would facilitate the modulation of NNK
biotransformation leading to the formation of NNAL. The results also show that
vitamin C-palmitate is a potent activator of NNK reduction in rat liver
microsomes. Thus, vitamin C-palmitate would mediate the metabolism of NNK through
reduction. The resulting NNAL-glucuronide is more readily eliminated in urine.
PMID- 10665375
TI - Purification and characterization of chitin-binding proteins from the hemolymph
of sweet potato hornworm, Agrius convolvuli.
AB - Three chitin-binding proteins (CBPs: CBP9, CBP15, CBP66) were identified from the
larval hemolymph of sweet potato hornworm, Agrius convolvuli. Two (CBP9 and
CBP15) of them have been isolated and purified by gel filtration (Superdex HR
75), cation-exchange chromatography (Mono S), and reverse-phase chromatography
(muRPC PC 2.1/3). In experiments to detect CBPs in hemolymph, we examined whether
ionic strength and existence of bovine serum albumin in the incubation solution
influenced binding affinity of CBPs to chitin. The N-terminal sequences of three
CBPs were determined by the automated Edman degradation and showed the sequence
homology in basic local alignment search tool search CBP15 and CBP66 were quite
similar to lysozymes and bovine serum albumins, respectively. In contrast, CBP9
is not similar to any other known protein, as judged from databank comparisons.
Therefore, we concluded that CBP9 is a novel protein with binding capacity to
chitin that is a component of the fungal cell wall. CBP9 has no antibacterial
activity against Escherichia coli and Micrococcus luteus, and also showed
negative response in hemagglutination assay. CBP9 is confirmed as a monomer with
a molecular mass of 9.14 kDa by electron spray ionization and matrix-assisted
laser desorption ionization mass spectrometry.
PMID- 10665376
TI - D-aspartate oxidase is present in ovaries, eggs and embryos but not in testis of
Xenopus laevis.
AB - D-aspartate oxidase (DASPO) is an FAD dependent flavoprotein which catalyzes the
oxidative deamination of D-aspartate using oxygen as electron acceptor. D
aspartate and DASPO are supposed to be involved in the regulation of the central
nervous system and in the animal development. This manuscript describes for the
first time the presence of DASPO in Xenopus laevis fertilized eggs and embryos
and suggests a different tissue distribution of this enzyme in adult male and
female animals. In particular, by means of 2D-electrophoresis and affinity
purified specific anti-DASPO antibodies, the enzyme was localized in fertilized
eggs of X. laevis and in ovaries of adult animals but it was shown to be absent
in the testis suggesting a gender specific expression. The protein from Xenopus
ovaries has been purified by means of immunoprecipitation and it has M(r) of 30
kDa and pI of 8.1.
PMID- 10665377
TI - Nitric oxide as a modulator of central respiratory rhythm in the isolated
brainstem of the bullfrog (Rana catesbeiana).
AB - Nitric oxide (NO) is a unique interneuronal neurotransmitter and/or
neuromodulator that is involved in a variety of physiological functions within
the central nervous system (CNS). In neural tissue, NO is generated from an
oxygen-dependent, constitutive NO synthase (NOS) by glutamatergic stimulation of
N-methyl-D-aspartate (NMDA) receptors. Recent studies indicate that NO has
excitatory effects on breathing within the CNS and mediates a central component
of the hypoxic ventilatory reflex in mammals. Because NMDA receptors are
important in central respiratory rhythmogenesis, we hypothesized that NO would
have significant effects on the central pattern generator (CPG) for breathing in
the brainstem. To test this hypothesis, the effects of NO on respiratory-related
neural activity were investigated using an in vitro brainstem preparation from
North American bullfrogs (Rana catesbeiana). Extracellular recordings of
respiratory-related burst activity were made from cranial nerves V, X and XII
before and during superfusion of the brainstem with NO-generating compounds, or
inhibitors of NO synthesis. Addition of the NO donor, sodium nitroprusside (SNP;
0.1-1.0 mM), or the amino acid precursor for NO synthesis, L-arginine (L-Arg;
0.01-1.0 mM), caused significant increases in respiratory-related burst
frequency. Inhibition of NOS with N omega-nitro-L-arginine (L-NA; 5-10 mM), a non
selective NOS inhibitor, caused a significant reduction in burst frequency or
reversibly abolished neural activity. Brainstem perfusion with the specific
neuronal NOS (nNOS) inhibitor, 7-nitro indazole (7-NI), produced significant,
dose-dependent reversible reductions in burst frequency at concentrations of 0.1,
0.5 and 1.0 mM. These results suggest that production of NO, probably via nNOS,
provides an excitatory input to the respiratory CPG in the amphibian brainstem.
Our results suggest that NO may be a necessary inter- or intracellular messenger
for neurotransmission and/or neuromodulation of central respiratory drive to
motor effectors in the bullfrog.
PMID- 10665378
TI - Central respiratory pattern generation in the bullfrog, Rana catesbeiana.
AB - There are two components to breathing pattern generation the production of the
pattern of neural discharge associated with individual breaths, and the pattern
in which breaths are produced to effect ventilation. Bullfrogs typically breathe
with randomly distributed breaths. When respiratory drive is elevated, breathing
becomes more regular and often episodic. Studies on in vitro brainstem-spinal
cord preparations of the adult bullfrog and in situ preparations of decerebrate,
paralyzed, unidirectionally ventilated animals suggest that output from the
central rhythm generator in frogs is conditional on receiving some input and that
a host of central inputs remain even in the most reduced preparations. There
appear to be descending inputs from sites in the dorsal brainstem just caudal to
the optic chiasma that cluster breaths into episodes, a strong excitatory input
caudal to this site but rostral to the origin of the Vth cranial nerve and,
possibly, segmental rhythm generators throughout the medulla that are normally
entrained to produce the normal breathing pattern. The data also suggest that the
shape of the discharge pattern (augmenting, decrementing) and timing of outputs
(alternating vs synchronous) associated with motor outflow during each breath are
also dependent on the interconnections between these various sites.
PMID- 10665379
TI - Learning, memory and a respiratory central pattern generator.
AB - In an attempt to elucidate the causal mechanisms underlying learning and memory
we have developed a model system, aerial respiration in the pond snail Lymnaea
stagnalis. A three-neuron central pattern generator (CPG) whose sufficiency and
necessity have been demonstrated mediates this behaviour. Aerial respiration,
while an important homeostatic behaviour, is inhibited by the activation of the
whole body withdrawal response that the animal uses to protect itself. We found
that it was possible to operantly condition snails not to perform aerial
respiration in a situation, a hypoxic environment, where aerial respiration
should predominate. Operant conditioning was achieved by eliciting the
pneumostome withdrawal response, part of the whole body withdrawal response, each
time the animal attempted to open its pneumostome to breathe. Yoked control
animals did not demonstrate an alteration in breathing behaviour. Subsequently we
determined neural correlates of this associative behaviour and found that
neuronal changes are distributed throughout the CPG. This preparation may afford
us the opportunity to determine the casual neuronal changes that underlie
learning and memory of associative conditioning.
PMID- 10665380
TI - The fictively breathing tadpole brainstem preparation as a model for the
development of respiratory pattern generation and central chemoreception.
AB - Spontaneous high-frequency, low-amplitude and low-frequency, high-amplitude
efferent bursting patterns of cranial and spinal motor nerve activity in the in
vitro brainstem preparation of the bullfrog tadpole Rana catesbeiana have been
characterized as fictive gill and lung ventilation, respectively (Gdovin MJ,
Torgerson CS, Remmers JE). Characterization of gill and lung ventilatory activity
in cranial nerves in the spontaneously breathing tadpole Rana catesbeiana, FASEB
J 1996;10(3):A642; Gdovin MJ, Torgerson CS, Remmers JE. Neurorespiratory pattern
of gill and lung ventilation in the decerebrate spontaneously breathing tadpole,
Respir Physiol 1998;113:135 146; Pack AI, Galante RJ, Walker RE, Kubin LK,
Fishman AP. Comparative approach to neural control of respiration, In: Speck DF,
Dekin MS, Revelette WR, Frazier DT, editors. Respiratory Control Central and
Peripheral Mechanisms. Lexington: University of Kentucky Press, 1993:52-57). In
addition, the ontogenetic dependence of central respiratory chemoreceptor
stimulation on fictive gill and lung ventilation has been previously described
(Torgerson CS, Gdovin MJ, Remmers JE. Fictive gill and lung ventilation in the
pre- and post-metamorphic tadpole brainstem, J Neurophysiol 1998, in press). To
investigate the neural substrates responsible for central respiratory rhythm
generation of gill and lung ventilation in the developing tadpole, we recorded
efferent activities of cranial nerve (CN) V, VII, and X and spinal nerve (SN) II
during changes in superfusate PCO2 before and after multiple transection of the
in vitro brainstem. The brainstem was transected between CN VIII and IX and the
response to changes in PCO2 was recorded. A second transection was then made
between the caudal margin of CN X and rostral to SN II. Preliminary data reveal
that robust gill ventilation was recorded consistently only if the segment of
brainstem included CN X, whereas the loci capable of eliciting fictive lung
bursting patterns appeared to differ depending on developmental stage. These data
demonstrate that the neural substrate required for fictive gill and lung
ventilation exists in anatomically separate regions such that the gill central
pattern generator (CPG) is located in the caudal medulla at the level of CN X
throughout development, whereas the location of the lung CPG is located more
rostrally at the level of CN VII in the post-metamorphic larva. Both in vivo and
in vitro studies revealed two distinct neural bursting patterns associated with
gill and lung ventilation. Sequential activation of CN V, VII, X were observed
during gill ventilation of in vivo and fictive gill ventilation in vitro, whereas
these nerve activities, along with SN II displayed more synchronous bursting
patterns of activation during lung ventilation and fictive lung breaths.
PMID- 10665381
TI - Characteristic transport of lactoferrin from the intestinal lumen into the bile
via the blood in piglets.
AB - Lactoferrin is a major iron-binding protein in milk from several species, such as
humans, monkeys, mice and sows. Using neonatal and weaner piglets, the
characteristic transfer of lactoferrin from intestinal lumen into bile via the
circulation was investigated. Bovine lactoferrin (1 or 3 g/kg body weight) was
infused into the stomach through a polyethylene tube or into the duodenum through
a duodenal catheter over 5 min. Peripheral blood and bile samples were collected
after the infusion. Lactoferrin absorbed into plasma and bile were assayed
quantitatively by double-antibody enzyme-linked immunosorbent assay, and
homogeneity of bovine lactoferrin in plasma and bile was identified by sodium
dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting methods.
Morphological investigation was carried out according to the peroxidase anti
peroxidase method. Following oral administration in neonatal pigs, bovine
lactoferrin appeared in the blood circulation and reached a peak level after 2 h.
It was confirmed immunohistochemically that lactoferrin was transported by
endocytosis via the epithelial cells. Lactoferrin absorbed into the blood was
also detected in the bile and reached a peak value 12 h after oral
administration. Transportation of lactoferrin from the intestinal lumen into the
bile via the bloodstream was also observed in weaner piglets. Lactoferrin
transported into plasma and bile was confirmed to be the same substance as
administrated lactoferrin by electrophoresis and immunoblotting methods.
Lactoferrin transported into bile was re-absorbed into the blood in neonatal
pigs. These results demonstrate that lactoferrin contained in milk is transported
into the circulation from the intestinal lumen and excreted into the bile,
suggesting the possibility of entero-hepatic circulation of lactoferrin in
neonatal pigs.
PMID- 10665382
TI - Modulation of stress hormones in rainbow trout by means of anesthesia, sensory
deprivation and receptor blockade.
AB - Sympathetic activation leading to increased levels of blood catecholamines, and
stimulation of the hypothalamic-pituitary inter-renal axis leading to increased
cortisol, are difficult to avoid when handling animals. Yet, in research on
effects of acute stress, elicitation of such responses must be minimized in the
control groups. The work examines means to achieve a minimally disturbed state in
rainbow trout (Oncorhynchus mykiss). Level of arousal was determined by
adrenaline and cortisol concentrations in plasma, and by the spleen:somatic
index. Fish were prepared for bleeding by rapid capture and concussion, by
infusion of anesthetic into the undisturbed home tank, by confinement in black
boxes, or by being fed alpha- and beta-receptor antagonists. Even when done
quickly, netting and concussion yielded fish with ca. 200-pmol adrenaline/ml
plasma. Cortisol was elevated (to > 10 ng/ml) within 30 s of stress initiation.
Surreptitious infusion of anesthetic (2-phenoxyethanol, PE) into tanks yielded
fish with lower adrenaline levels (means 19.34 and 19.58 pmols/ml in home tank
and black boxes, respectively). Among fish given phentolamine and propranolol,
spleen:somatic indices and plasma adrenaline were higher than in diet controls,
whether undisturbed or stressed, indicative of successful receptor blockade.
Since careful infusion of 2-PE yielded the lowest adrenaline levels, and requires
no special apparatus, it is the method of choice for obtaining minimally stressed
fish.
PMID- 10665383
TI - Effects of thermal acclimation on nervous conduction and muscle contraction in
the frog Rana temporaria.
AB - The effects of season and acclimation temperature on the latency of the leg
withdrawal reflex and three of its components have been studied: conduction
velocity in the sciatic nerve, spinal conduction time, and contraction time of
gastrocnemius muscle. The latency of the leg withdrawal reflex was markedly
shortened by cold acclimation: the reaction times were at 6 degrees C 1.54 s in 4
degrees C acclimated and 3.97 s in 24 degrees C acclimated winter frogs. Also,
the temperature dependence of the reflex latency was reduced by cold acclimation.
Thus, frogs acclimated to cold responded to external stimuli in cold more rapidly
than warm-acclimated ones. This cold adaptation of the reflex could not be
explained by changes in its studied components. These made up only one-tenth of
the reflex response time, and either did not show significant cold acclimation
(muscle contraction and spinal conduction times in summer) or showed inverse
acclimation, especially when measured at high temperatures (i.e. conduction
velocities were reduced by acclimation to cold). Thus, the cold acclimation of
the reflex response probably resides in the sensory component of the response.
The inverse temperature adaptation response of conduction velocities may reflect
a reduced ion permeability across cellular membranes in cold which decreases
metabolic energy expenditure during inactive periods.
PMID- 10665384
TI - Pre-existing bacterial infections, not stress fever, influenced previous studies
which labeled Gerrhosaurus major an afebrile lizard species.
AB - Early studies indicated that the Sudan plated lizard, Gerrhosaurus major, did not
exhibit a febrile response when challenged with bacterial pyrogen. More recent
results indicated that a 14-day antibiotic treatment regime produced a
significant decrease (0.5 +/- 0.1 degree C) in the mean selected body temperature
(MSBT) for this species (31.3 +/- 0.2-30.8 +/- 0.2 degrees C). The antibiotic
treatment results suggested that G. major already had a fever caused by a pre
existing bacterial infection. The current study was designed first to determine
if a sub-population of G. major, with a higher mean pre-antibiotic treatment MSBT
would exhibit a greater decrease in MSBT after antibiotic treatment. A 14-day
antibiotic treatment regime for G. major (N = 7) with MSBTs > or = 31.9 degrees C
(mean 32.4 +/- 0.2 degrees C) produced a significant decrease of 1.7 +/- 0.4
degrees C in MSBT to 30.7 +/- 0.3 degrees C. Analysis of the combined antibiotic
treatment MSBT data from [13] and the current study demonstrated that the
magnitude of the change in MSBT after antibiotic treatment was dependent upon the
pre-antibiotic treatment MSBT. These data imply that animals with a greater pre
treatment MSBT and greater MSBT change had a greater magnitude fever. In the
second portion of this study the MSBT for individual lizards was measured during
separate experiments using both indwelling cloacal thermocouples taped to the
tail of the lizard and telemeters implanted into the peritoneal cavity of the
lizard. This second study was designed to determine if measurement of Tb using
thermocouples induced a stress fever which may have masked a portion of the
pyrogen-induced fever. The MSBT measured using indwelling cloacal thermocouples
(30.5 +/- 0.3 degrees C) was not significantly greater (T > 0.05) than the MSBT
increased using telemeters (31.0 +/- 0.2 degrees C). The results of the
experiments from this study demonstrate that the previously reported afebrile
state for G. major was the result of animals having pre-existing bacterial
infections. G. major does exhibit a febrile response similar to other lizard
species.
PMID- 10665385
TI - Respiratory consequences of feeding in the snake Python molorus.
AB - Snakes can ingest large meals and exhibit marked increases in metabolic rate
during digestion. Because postprandial oxygen consumption in some snakes may
surpass that attained during exercise, studies of digestion offers an alternative
avenue to understand the cardio-respiratory responses to elevated metabolic rate
in reptiles. The effects of feeding on metabolic rate, arterial oxygen levels,
and arterial acid-base status in the snake Python molorus are described. Four
snakes (180-250 g) were cannulated in the dorsal aorta and blood samples were
obtained during 72 h following ingestion of a meal (rat pups) exceeding 20% of
body weight. Oxygen consumption increased from a fasting value of 1.71 +/- 0.08
to 5.54 +/- 0.42 ml kg-1 min-1 at 48 h following feeding, and the respiratory gas
exchange ratio increased from 0.67 +/- 0.02 to a maximum of 0.92 +/- 0.03 at 32
h. Plasma lactate was always less than 0.5 mM, so the postprandial increase in
metabolic rate was met by aerobic respiration. In fasting animals, arterial PO2
was 66 +/- 4 mmHg and haemoglobin-O2 saturation was 92 +/- 3%; similar values
were recorded during digestion, but haematocrit decreased from 15.8 +/- 1.0 to
9.8 +/- 0.8 due to repeated blood sampling. Plasma [HCO3-] increased from a
fasting level of 19.3 +/- 0.8 to 25.8 +/- 1.0 mmol l-1 at 24 h after feeding.
However, because arterial PCO2 increased from 21.1 +/- 0.5 to 27.9 +/- 1.4 mmHg,
there was no significant change in arterial pH from the fasting value of 7.52 +/-
0.01. Acid-base status returned to pre-feeding levels at 72 h following feeding.
The increased arterial PCO2 is most likely explained by a reduction in
ventilation relative to metabolism, but we predict that lung PO2 does not
decrease below 115 mmHg. Although ingestion of large meals is associated with
large metabolic changes in pythons, the attendant changes in blood gases are
relatively small. In particular, the small changes in plasma [HCO3-] and stable
pH show that pythons respond very differently to digestion than alligators where
very large alkaline tides have been observed. It is unclear why pythons and
alligators differ in the magnitude of their responses, but given these
interspecific differences it seems worthwhile to describe arterial blood gases
during digestion in other species of ectothermic vertebrates.
PMID- 10665386
TI - Fate and distribution of 14C-atrazine in a tropical oxisol.
AB - The herbicide atrazine is the most commonly detected pesticide in groundwater
world-wide. A new microcosm test-system was used to determine the fate of 14C
atrazine in a Brazilian oxisol. 14C Ring-labelled atrazine was applied in a
mixture with the commercial product Gesaprim 500 (Novartis) at a rate of 3 kg ha
1. During two months, about 1% of the initially applied amount was lost by
volatilization. The mineralization of the pesticide, measured directly using
14CO2 evolved from the applied pesticide, was between 0.09% and 0.16%, whereas
less than 0.2% was leached. The distribution of radioactivity in the soil profile
showed that most of the radioactivity remained in the top soil down to a 3 cm
depth. The radioactivity in the upper 3 cm of the column was adsorbed perferably
in fulvic acid (FA) and human fractions.
PMID- 10665387
TI - The n-octanol and n-hexane/water partition coefficient of environmentally
relevant chemicals predicted from the mobile order and disorder (MOD)
thermodynamics.
AB - The quantitative thermodynamic development of the mobile order and disorder
theory in H-bonded liquids is extended in order to predict the partition
coefficient. With respect to the classical predictive methods, the great
advantage of the present approach resides in the possibility of predicting
partition coefficient not only in the reference n-octanol/water partitioning
system, but also in any mutually saturated two-phase system made up of two
largely immiscible solvents. Constructed from the various free energy
contributions encoded in the distribution process, the model furthermore provides
a useful tool to understand both the origin and the factors, like the solute
molar volume, that determine the partitioning of non-electrolytes between two
immiscible liquid phases. From the comparison of the relative magnitude of the
terms which contribute to the overall log P value, much information can also be
gained concerning the variation of the partition coefficients of the same
substances in different distribution systems. For example, the model has
successfully been applied to the log P prediction of a number of environmentally
important chemicals of varying structure, size and chemical nature in the n
octanol/water and n-hexane/water systems. Whatever the complexing or non
complexing substances studied, the hydrophobic effect always represent the
driving force that rules distribution processes in the aqueous environments. As
the dominant contribution to the partition coefficient in any organic/aqueous
binary system, it is evidenced why hydrophobicity is usually considered to be a
good measure of lipophilicity.
PMID- 10665388
TI - Fuzzy clustering analysis of the first 10 MEIC chemicals.
AB - In this paper, we discuss the classification results of the toxicological
responses of 32 in vivo and in vitro test systems to the first 10 MEIC chemicals.
In this order we have used different fuzzy clustering algorithms, namely
hierarchical fuzzy clustering, hierarchical and horizontal fuzzy characteristics
clustering and a new clustering technique, namely fuzzy hierarchical cross
classification. The characteristics clustering technique produces fuzzy
partitions of the characteristics (chemicals) involved and thus it is a useful
tool for studying the (dis)similarities between different chemicals and for
essential chemicals selection. The cross-classification algorithm produces not
only a fuzzy partition of the test systems analyzed, but also a fuzzy partition
of the considered 10 MEIC (multicentre evaluation of in vitro cytotoxicity)
chemicals. In this way it is possible to identify which chemicals are responsible
for the similarities or differences observed between different groups of test
systems. In another way, there is a specific sensitivity of a chemical for one or
more toxicological tests.
PMID- 10665389
TI - Bisphenol A concentrations in receiving waters near US manufacturing and
processing facilities.
AB - Bisphenol A (BPA) (CAS 80-05-7) was analyzed in receiving waters upstream and
downstream of US manufacturers (1996 and 1997) and processors (1997) during
seasonal low flow periods. BPA was not detected (< 1 microgram/l) in any surface
water sample in 1996 or at six of seven sites in 1997. Concentrations near the
seventh site ranged from 2 to 8 micrograms/l; however, its receiving stream had
no measurable flow and concentrations represent undiluted effluent. All surface
water concentrations from this and other studies were less than the freshwater
predicted no effect concentration (PNEC) of 64 micrograms/l, suggesting that BPA
discharges from manufacturing and processing facilities to surface water do not
pose an environmental concern.
PMID- 10665390
TI - Volatile organic compounds in the surface waters of northern Greece.
AB - An investigation into the occurrence of volatile organic compounds (VOCs) was
conducted for a period of two years in the surface waters of Northern Greece.
Samples from four rivers and five lakes were taken seasonally and analyzed for
VOCs. The analysis has been performed by purge-and-trap (PAT) gas chromatographic
mass spectrometric (GC-MS) technique. The most commonly encountered VOCs in
surface waters were chloroform, carbon tetrachloride, trichloroethylene,
dichlorobromomethane, tetrachloroethylene, and chlorodibromomethane.
PMID- 10665391
TI - Nitro-PAH in ambient particulate matter in the atmosphere of Athens.
AB - Nitrated polynuclear aromatic hydrocarbons (NPAH) with a molecular mass of 247
Daltons were found in soot collected in downtown Athens during a campaign
performed in 1996. In particular, 2-nitrofluoranthene (2-NFa) and 2-nitropyrene
(2-NPy), which are mainly related to photo-induced chemical processes occurring
in the atmosphere, were more abundant than 1-nitropyrene (1-NPy) usually
associated to motor vehicle exhaust.
PMID- 10665392
TI - Comparison of an enzyme-linked immunosorbent assay (ELISA) to gas chromatography
(GC)--measurement of polychlorinated biphenyls (PCBs) in selected US fish
extracts.
AB - The analysis of PCBs in fish tissues by immunoassay methods was evaluated using
fish collected from a US monitoring program, the National Contaminant
Biomonitoring Program of the US Department of Interior, Fish and Wildlife
Service. Selected composite whole fish samples, which represented widely varying
concentrations and sources of PCBs, were extracted and subjected to congener PCB
analysis by gas chromatography (GC) and total PCB analysis using an ELISA (ePCBs)
calibrated against technical Aroclor 1248. PCB congener patterns in these fishes
were different from the patterns found in commercial Aroclors or their
combinations as demonstrated by principal component analysis of normalized GC
congener data. The sum of the PCB congeners measured by GC (total-PCBs) ranged
from 37 to 4600 ng/g (wet weight). Concentrations of PCBs as determined by the
ELISA method were positively correlated with total-PCBs and the ePCBs/total-PCBs
ratios for individual samples ranged from 1 to 6. Ratios of ePCBs/total-PCBs for
dilutions of Aroclors 1242, 1254, and 1260 and for matrix spikes range from 0.6
for 1242 to 2.5 for 1254 and 1260. These results suggest that higher chlorinated
PCB congeners have higher affinity for the anti-PCB antibodies. Partial least
squares with latent variable analysis of GC and ELISA data of selected Aroclors
and fish samples also support the conclusion that ELISA derived PCB
concentrations are dependent on the degree of chlorination.
PMID- 10665393
TI - Biological denitrification in a closed seawater system.
AB - Build-up of high nitrate concentrations in closed seawater systems where primary
productivity is undesirable and water changes are impractical presents unique
problems. Nitrate concentration in Ocean Tank at the New Jersey State Aquarium
reached 9500 microM after 6 years of operation. A biological denitrification
system was installed in 1998 and nitrate concentration in the aquarium decreased
to 7000 microM within the first 100 days of operation. The system offers
additional benefits by increasing the pH and alkalinity of seawater and providing
a reducing environment to balance the oxidizing disinfection environment in the
aquarium. The initial performance of the denitrification system was monitored and
two semi-empirical models were developed: one based on the actual methanol
additions, and another based on the daily amounts of nitrogen gas removed. The
first model predicts a net nitrate decrease of 39 microM/day in the aquarium. The
second model predicts a net decrease of 25 microM/day, in good agreement with the
empirical value of 23 microM/day. This indicates that nitrogen gas removal is the
controlling factor during denitrification in this facility, and the second model
can be used to predict and optimize the operation of the system.
PMID- 10665394
TI - Biodegradation of pyrene by sediment fungi.
AB - Micromycetes were isolated from PAHS-contaminated sediment and identified. They
were investigated for pyrene degradation (10 mg l-1) in liquid synthetic medium
for two days. Among the 41 strains isolated, 10 highly degraded pyrene (> 2.4 mg
g-1 dry weight): two Zygomycetes (Mucor racemosus, M. racemosus var.
sphaerosporus), 6 Deuteromycetes (Gliocladium virens, Penicillium simplicissimum,
P. janthinellum, Phialophora alba, P. hoffmannii, Trichoderma harzianum), a
Dematiaceae (Scopulariopsis brumptii) and a Sphaeropsidale (Coniothyrium
fuckelii). Zygomycetes appeared as one of the most efficient taxonomic groups,
especially with Mucor racemosus. Penicillium crustosum was the only strain that
did not degrade pyrene. Among the 10 fungi which were performant for pyrene
degradation, nine were not yet reported in the literature and showed a real value
for PAH remediation.
PMID- 10665395
TI - Nitro musks, nitro musk amino metabolites and polycyclic musks in sewage sludges.
Quantitative determination by HRGC-ion-trap-MS/MS and mass spectral
characterization of the amino metabolites.
AB - Nitro- and polycyclic musks were quantified in sewage sludge samples from
different catchment areas using high-resolution gas chromatography (HRGC) and ion
trap MS/MS. Collision induced dissociation (CID) turned out to be a useful tool
for quantification of the analytes. Negative chemical ionization (NCI) quadrupole
MS in the selected ion mode (SIM) showed similar sensitivities compared to ion
trap MS/MS. Among the nitro musks, musk ketone (MK) and musk xylene (MX) were the
main compounds in predominantly domestic sewage sludges, found at low
microgram/kg dry matter (d.m.) whereas polycyclic musks were present in domestic
as well as in industrial sludges up to 12 mg/kg d.m. Galaxolide (HHCB) and
Tonalide (AHTN) were the major polycyclic musks found in the sludges. Amino
metabolites of the nitro musks, amino musk xylene (AMA), amino musk moskene (AMM)
and amino musk ketone (AMK) were detected for the first time in sewage sludges,
and reached partly higher concentrations compared to the parent compounds.
PMID- 10665396
TI - Degradation of 2,4,6-trinitrotoluene in water and soil slurry utilizing a calcium
peroxide compound.
AB - The degradation of 2,4,6-trinitrotoluene was examined in pure water and
contaminated soil slurry using calcium peroxide as a source of solid hydrogen
peroxide and oxygen. The extent of TNT oxidation was compared with that obtained
by using hydrated lime, which is normally generated by slurrying CaO2 in water
and contained in CaO2 technical formulation (approximately 50%, w/w). Complete
TNT degradation occurred between 280 min, 0.1% CaO2/Ca(OH)2 and 20 min, 1%
CaO2/Ca(OH)2. A large part of the generated oxidation products, 80-90%, were
absorbed on the solid calcium hydroxide, whereas the remaining 10-20% was
detected in solution until 48 h. Removal of nitro groups was extremely effective
in CaO2 slurry, where all the nitrogen (3 mol per mol of TNT) was removed from
TNT within 240 min. Respect to calcium hydroxide, the peroxy compound liberated
H2O2 in solution, 370 mg l-1 at 0.2% CaO2, w/v, which then decomposed within 480
min. Most of the 14C-TNT was retained more strongly on the calcium hydroxide
generated by slurrying CaO2. This pool remained adsorbed on the solid until pH
dropped below 5.8. The treatment of a contaminated soil slurry, 700 mg TNT kg-1,
reduced CH3CN extractable TNT below 20 mg kg-1 at very low concentration of
CaO2/Ca(OH)2, approximately 0.2%, w/w. Both oxidants do not lead to soil
sterilization as the phosphorus added to neutralize the pH serves as a source of
nutrient for the soil biomass.
PMID- 10665397
TI - Monitoring of bioremediation by soil biological activities.
AB - An evaluation of soil biological activities as a monitoring instrument for the
decontamination process of a mineral-oil-contaminated soil was made using
measurements of microbial counts, soil respiration, soil biomass and several
enzyme activities. The correlations between these parameters and with the levels
of hydrocarbon residues were investigated; the effects of different N- and P
sources on hydrocarbon decontamination and soil biological activities were
determined. Inorganic nutrients stimulated hydrocarbon biodegradation but not all
biological activities to a significant extent. Biodegradation could be monitored
well by soil biological parameters: the residual hydrocarbon content correlated
positively with soil respiration, biomass-C (substrate-induced respiration), and
with activities of soil dehydrogenase, urease and catalase. Soil lipase activity
and the number of hydrocarbon utilizers correlated negatively (P < 0.0001) with
the remaining hydrocarbon content.
PMID- 10665398
TI - Minimization of cobalt nuclide emissions in supercritical water oxidation of
spent resin.
AB - A rapid and complete destruction of organics in the supercritical water oxidation
(SCWO) of the Co-exchanged resin was found experimentally. Due to an extremely
low solubility of CoSO4 salt formed and separated effectively in the SCWO
process, a minimal release of the nuclide Co would be warranted. In addition,
recycling of Co nuclides is also possible by decomposition of the CoSO4 species
at elevated temperatures (> 1040 K).
PMID- 10665399
TI - Non-enzymatic reduction of azo dyes by NADH.
AB - Nicotinamide adenine dinucleotide (NADH) reduces a variety of azo dyes by four
electrons to generate the corresponding aromatic amines. This reduction is pH
dependent and increases with decreasing pH. Reduction of 4-(4'-sulfophenylazo)
phenol and 2-(4'-sulfophenylazo)-phenol, specifically substituted with methyl,
methoxy, halo, and nitro groups, was examined to determine the susceptibility of
azo dyes to reduction by NADH. Except for the nitro-substituted azo dyes, all
other azo dyes were reduced. Possible mechanisms of reduction are proposed. The
implications of our findings to microbial degradation and mammalian metabolism of
azo dyes are discussed.
PMID- 10665400
TI - Effects of heterocyclic PAHs (N, S, O) on the biodegradation of typical tar oil
PAHs in a soil/compost mixture.
AB - The interaction phenomena during the biodegradation of typical coal tar
polycyclic aromatic hydrocarbons and their heterocyclic analogues (N, S, O) were
investigated in an artificially contaminated AhA1-horizon/compost mixture. All
compounds were partly or completely biodegraded. Degradation of two- to five-ring
PAHs was inhibited by the presence of hetero-PAHs, whereas degradation of just
some hetero-PAHs was inhibited by the presence of PAHs. Among the hetero-PAHs the
sulphur-containing compounds were less susceptible to degradation than the
corresponding oxygen- or nitrogen-containing analogues. The basic azaarene
acridine showed an extreme persistence and strong sorption to the soil matrix
proved by an increase of recovery after saponification of the soil matrix.
PMID- 10665401
TI - Degradation and toxicity reduction of textile effluent by combined photocatalytic
and ozonation processes.
AB - To minimize the environmental impact of textile effluents, mainly related to
their high coloration and the presence of toxic or carcinogenic reactive dyes,
the efficiency of photochemical and ozonation processes, applied in the form of
isolated and combined procedures, were evaluated. The investigation was focused
on the reduction of total organic carbon content (TOC), color and acute toxicity
(monitoring by inhibition of Escherichia coli respiration). For a reaction time
of 60 min, the anatase TiO2-assisted photocatalytic process produces color and
TOC reduction of about 90% and 50%, respectively. Meanwhile, the ozonation
process gives a decolorization of about 60% but negligible TOC reduction. When
the processes were applied in a simultaneous form, the decolorization was almost
complete and the TOC reduction was higher than 60%. The three treatments studied
yield an acute toxicity reduction of around 50%.
PMID- 10665402
TI - The behaviour of N-(phenylsulfonyl)-glycine and phenacetin in a municipal sewage
treatment plant--a case study.
AB - The behaviour of N-(phenylsulfonyl)-glycine (PSG) and phenacetin (PHE) in a
municipal sewage treatment plant near Heidelberg, Germany, was investigated in
the summer of 1997. For that purpose, 10 g of each substance was dissolved and
poured simultaneously into the influent. In addition to the spiked compounds, the
samples of the influent, the biological stage and the effluent were analyzed for
N-(phenylsulfonyl)-sarcosine (PSS), N-methyl-N-(phenylsulfonyl)-amide (MPS), N
methyl-phenacetin, N-methyl-N-(phenylsulfonyl)-epsilon-aminocaproic (PSC) acid
and its degradation product N-methyl-N-(phenylsulfonyl)-gamma-aminobutyric (PSB)
acid. Within 24 h PHE could be detected almost quantitatively in the effluent.
Since N-methyl-phenacetin could not be found in any of the samples, apparently no
methylation of the amino-group of PHE took place. The amount of PSG in the
effluent was within 24 h 26.0 g, which is more than two fold higher than added.
The decrease of PSG between biological stage and effluent and the increase of PSS
within the same time correlate well. Therefore, the formation of PSS by microbial
methylation of PSG in the sewage treatment plant must be assumed.
PMID- 10665403
TI - Fate of bromine in pyrolysis of printed circuit board wastes.
AB - Behavior of Br in pyrolysis of the printed circuit board waste with valuable
copper and oil recycling has been studied in the present work. Experimentally,
pyrolysis of the printed circuit board waste generated approximately 40.6% of
oils, 24.9% of noncondensible gases and 34.5% of solid residues that enriched in
copper (90-95%). The cuts of the oils produced from pyrolysis of the printed
circuit board waste into weighted boiling fraction were primarily light naphtha
and heavy gas oil. Approximately 72.3% of total Br in the printed circuit board
waste were found in product gas mainly as HBr and bromobenzene. However, by
extended X-ray absorption fine structural (EXAFS) spectroscopy, Cu-O and Cu-(O)
Cu species with bond distance of 1.87 and 2.95 A, respectively, were observed in
the solid residues. Essentially, no Cu-Br species was found.
PMID- 10665404
TI - The pH and anion effects on the heterogeneous photocatalytic degradation of o
methylbenzoic acid in TiO2 aqueous suspension.
AB - This investigation used UV light of 365 nm and titanium dioxide in aqueous
suspension to study the photocatalytic reaction of o-methylbenzoic acid under the
influence of pH values, anion additives and the varieties of titanium dioxide.
From experimental results, under the condition of 5 g/l TiO2, pH 3 and light
intensity of 2.45 mW/cm2, 0.1 mM of o-methylbenzoic acid could be completely
decomposed in 2 h. The reaction was faster with lowering pH, and was found to be
apparent first-order following Langmuir-Hinshelwood model. In the presence of
anion additives, the inhibitive effect of chloride ions was larger than that of
sulfate ions under acidic condition for Degussa brand titanium dioxide, but
without influence using Janssen brand. Both brands, however, promoted the
mineralization of o-methylbenzoic acid (o-MBA).
PMID- 10665405
TI - The interaction "light, Fe(III)" as a tool for pollutant removal in aqueous
solution: degradation of alcohol ethoxylates.
AB - The photoinduced degradation of an alcohol ethoxylate (AE) (Brij 30) by Fe(III)
in aqueous solution has been investigated. The study was carried out with the
major fraction of ethoxymers having an alkyl chain length of 12 carbon atoms and
n ethoxy units E (C12En). The Fe(III) sensitised degradation of this fraction
occurs efficiently at 365 nm. The rate of degradation depends on the
concentration of Fe(OH)2+, the most photoreactive species in terms of .OH radical
formation. Formate ethoxylates were identified as photoproducts and shortening of
the ethoxylated chain all along the degradation process was observed. The
mechanism of Brij 30 degradation implies a major .OH radicals attack on the
polyethoxylated chain. For prolonged irradiations, the total degradation of Brij
30 and of the photoproducts is obtained. Consequently, the degradation
photoinduced by iron (III) could be an efficient method of AEs removal in water.
PMID- 10665406
TI - Solar photocatalytic mineralization of commercial pesticides: acrinathrin.
AB - A comparative study of the degradation of commercial acrinathrin spiked in water
using TiO2 photocatalysis and photolysis under sunlight was performed. Samples
were analysed by liquid chromatography-diode array detector (HPLC-DAD) and gas
chromatography-ion trap-mass spectrometric detector (GC-ITMS). Additional total
organic carbon (TOC) analyses were carried out to evaluate the mineralisation
rates. One photoproduct, 2-phenoxy benzaldehyde, was unequivocally identified and
evaluated by GC-ITMS during the processes. Although acrinathrin is almost
destroyed when exposed to irradiation for more than 400 h, photocatalysis with
TiO2 noticeably reduced degradation to a few hours. In this case, with the
additional presence of peroxydisulphate, in less than 2 h acrinathrin is
completely destroyed. Mineralisation of acrinathrin, without catalyst, was only
around 50% after 400 h of irradiation.
PMID- 10665407
TI - Light-induced disappearance of nitrite in the presence of iron (III).
AB - Understanding of rapid disappearance of nitrite in natural waters and its impact
on nitrogen natural cycling has remained limited. We found that NO2- disappeared
rapidly in pH 3.2 aqueous Fe(III) solutions both in sunlight and in 356 nm light.
Quantum yields of the NO2- loss at 356 nm were 0.049-0.14 for initial levels of
10-80 microns NO2- and 200 microns Fe(III). The NO2- loss (at 356 nm) followed
apparent first-order kinetics. The rate constants were 1.3 x 10(-3) (40 microns
NO2-) and 4.1 x 10(-4) s-1 (80 microns NO2-) for 100 microns Fe(III), and 2.3 x
10(-3) (40 microns NO2-) and 7.5 x 10(-4) s-1 (80 microns NO2(-1)) for 200
microns Fe(III) (t1/2 = 8.7, 27.9, 5.1, and 15.3 min, respectively). The rate
constants were directly proportional to [Fe(III)]0 and inversely proportional to
[NO2-]0. Agreement between the rate constants obtained experimentally and those
calculated mechanistically supports the hypothesis that NO2- was oxidized to NO2
by .OH radicals from photolysis of FeOH2+ complexes, and at high [NO2-]0 (e.g.,
80 microns) relative to [Fe(III)]0, hydrolysis of NO2 or N2O4 to form NO3- and
NO2- could be significant. This study showed that light and Fe(III)-induced
oxidation of NO2- (rate = approximately 10(-1)-10(-2) microns s-1) was more rapid
than its direct photolysis (rate = approximately 10(-4) microns s-1), and the
photolysis could be a significant source of .OH radicals only in cases where the
Fe(III) level is much lower than the NO2- level ([Fe(III)]/[NO2-] < 1/80). This
study suggests that the light and Fe(III)-induced oxidation of NO2- would be one
potential important pathway responsible for the rapid transformation of NO2- in
acidic surface waters, especially those affected by acid-mine drainage or
volcanic activities. This study also may be of interest for modeling certain
acidic atmospheric water environments.
PMID- 10665408
TI - Temporal ecological assessment of oil contaminated soils before and after
bioremediation.
AB - Ecotoxicity methods were used to assess different soil and oil combinations
before, during and after laboratory bioremediation with associated hydrocarbon
analysis. Heavy, medium and light crude oil (API gravity 14, 30, and 55) was
spiked (ca. 5% w/w) into two sandy soils in the laboratory having organic carbon
concentrations of 0.3 (Norwood) and 4.7% (Norwood/Baccto). The earthworm (Eisenia
fetida) 14-d lethality assay, the modified Microbics Microtox Solid-Phase assay,
and the 14-d plant seed germination and growth assays using corn, wheat and oats,
were spiked and tested during a 360-d laboratory remediation. Eisenia was the
most sensitive of the three methods utilized with survival increasing throughout
bioremediation with fastest toxicity reduction in the high carbon Norwood/Baccto
soils where LC50's were 100% or greater at the end of 90-d whereas, > 150-d were
required to achieve a similar result in the low carbon soil. Analysis of the
undiluted treatments with oily soil alone showed that earthworm survival was high
after 90-d in all high organic carbon soils, and after eight months in the low
carbon soils, except for the Norwood soil-light oil treatment, which required 360
d to achieve 100% survival. The Microtox assay was less sensitive with EC50's
100% or greater observed after 90-d in high carbon soils and after 240-d for all
low carbon soils. After bioremediation, no effects on seed germination were
observed, although some plant growth inhibition effects remained. There was no
direct correlation between total petroleum hydrocarbon concentrations and
toxicity.
PMID- 10665409
TI - Semiconductor-assisted photodegradation of lignin, dye, and kraft effluent by Ag
doped ZnO.
AB - This work reports a preliminary study of semiconductor-assisted photochemical
degradation of lignin, Remazol Brilliant Blue R and Kraft E1 paper effluent by
using ZnO and Ag-doped ZnO photocatalysts. The doped semiconductor was prepared
in the reaction media by photoreduction of silver nitrate. With the use of 100 mg
of ZnO and 15 mg of Ag-ZnO, almost total decolorization of the dye and lignin
samples in reaction times lower than 60 min were observed. Extending the
photochemical reaction up to 120 min, the total organic carbon content (TOC) was
reduced in 90%. For the paper effluent, a fast decolorization was obtained for
relatively short reaction times. However, de TOC reduction was negligible (near
of 10%) up to high reaction times (300 min). By using the Ag-ZnO photocatalyst,
the toxicity of lignin and Kraft E1 effluent toward E. Coli was completely
removed. For the dye, the formation of transient toxic species was observed.
PMID- 10665410
TI - Semiconductor-assisted photocatalytic degradation of reactive dyes in aqueous
solution.
AB - This work reports the semiconductor-assisted photochemical degradation of
reactive dyes. In an oxygenated-UV-ZnO system almost total decolorization of
Remazol Brilliant Blue R, Remazol Black B, Reactive Blue 221 and Reactive Blue
222 was observed in reaction times of about 60 min. Extending the photochemical
treatment up to 120 min, mineralization higher than 80% for all the dyes was
observed. During the same period, the residual acute toxicity was significantly
reduced only for Remazol Black B. A systematic optimization study carried out by
factorial design showed that for the reactive dyes tested, the ZnO semiconductor
exhibits a better efficiency than that observed with anatase TiO2. A synergistic
effect in the coupled TiO2-ZnO system was not observed.
PMID- 10665411
TI - Use of abiotic oxidative-reductive technologies for remediation of munition
contaminated soil in a bioslurry reactor.
AB - The possibility to clean-up TNT contaminated soil, 400 mg TNT kg-1, surrounding
Nebraska Ordnance Plant's (US), below the USEPA goal of 17.2 mg TNT kg-1 using
Fenton oxidation (Fe2+ + H2O2), Fe0 reduction, combined Fe0/H2O2 and CaO2 was
explored at pilot scale. Treatments were performed in a 60 l airlift reactor,
which was a prototype of larger commercial unit. All the treatments reduced TNT
soil concentration below the required clean-up goal and in shorter time with
respect to bench scale. Using 2% (w/w) Fe0, TNT soil concentration reduced below
the required standard just within 4 h. No significant TNT destruction improvement
was observed when 2% Fe0 (w/w soil) was combined with four sequential additions
of 0.25% H2O2. Laboratory experiments with 14C-TNT indicated that most of the
14C, approximately 80%, was unextractable residue. A time greater than 24 h was
required either with Fenton reagent, 8 x (80 mg Fe2+ L-1 + 0.125% H2O2) or 0.2%
(w/w) CaO2. The optimal performance of Fenton reagent was obtained when the
reagent was added in eight increments rather than in a single or double dose and
less cumulative amount of H2O2 (0.75%) was required with respect to bench scale
(1%).
PMID- 10665412
TI - Enzymatic and osmoregulative alterations in white shrimp Litopenaeus vannamei
exposed to pesticides.
AB - Pesticide pollution in coastal ecosystems of Sinaloa, Mexico is considered to be
a cause for slow growth, increase of diseases and sometimes massive mortality of
shrimp. So it was necessary to develop fast techniques to detect pesticide
pollution in shrimp habitats. Enzymatic and osmoregulation tests in shrimp
exposed to DDT, Lindane, Chlordane, Lorsban, Gusathion, Folidol, Diazinon and
Tamaron were carried out. Activity reductions from 11 to 2 units/ml in
acetylcholinesterase and from 1 to 0 units/l in transaminases (GOT and GPT) were
detected. Also increases in osmoregulation were observed in shrimp exposed to
Folidol, Diazinon and Gusation, whereas decreases with DDT, Lindane and Lorsban
at salinity 50/1000. We conclude that pesticides are causing alterations in these
biochemical functions and this kind of tests represent a rapid and inexpensive
method for pesticide pollution detection.
PMID- 10665413
TI - Effect of certain chemicals on the reproduction of medaka (Oryzias latipes).
AB - In order to understand the effects of estrogenic chemicals on fish reproduction,
we exposed male medaka (Oryzias latipes) to a natural estrogen [17 beta-estradiol
(17 beta-E2)] and three estrogenic chemicals [bisphenol-A, nonylphenol (NP) and
di(2-ethylhexyl)phthalate (DEHP)]. After two weeks' exposure, one male medaka was
kept together with two female medaka for spawning, and the number of eggs and
hatchings were compared to those of a negative control group. The results
indicated that exposure to 17 beta-E2 caused a significant decrease in the number
of eggs and hatchings as compared to the negative control group at and above 3
nmol/l. Also, the highest concentrations of bisphenol-A and NP caused a decrease
in the number of hatchings, but no decrease in hatchings was observed in DEHP
treatments. In the treatment using these chemicals the decrease in egg numbers
was not so much as in hatching numbers. When compared to other in vitro studies,
concentrations observed to have adverse effects on reproduction in this study are
generally lower. In addition, it was suggested that physical alterations, such as
an induction of plasma vitellogenin, were caused at much lower concentrations
than those at which a decline in reproductivity was actually induced.
PMID- 10665414
TI - Accumulation pattern and biotransformation enzyme induction in rainbow trout
embryos exposed to sublethal aqueous concentrations of 3,3',4,4'
tetrachlorobiphenyl.
AB - Accumulation pattern of 3,3',4,4'-tetrachlorobiphenyl (PCB 77) and the exposure
time needed to activate the monooxygenase (EROD) and conjugation (GST) enzyme
systems of fish at the advanced embryonic stage were studied. Eyed stage embryos
of rainbow trout (Oncorhynchus mykiss) were exposed to sublethal doses (0, 1, 10,
and 100 micrograms/l) of PCB 77. Results indicated direct accumulation of the
chemical into the eggs, but the exposure time was not long enough for PCB 77 to
reach constant steady state. However, at the two lowest test concentrations (1
microgram/l and 10 micrograms/l) a temporary plateau at chemical accumulation was
reached at the third exposure day (185 and 1221 ng PCB/g egg w.w). At the highest
concentration (100 micrograms/l) the decrease in the accumulation rate was
already evident after the first day (2182 ng PCB/g egg w.w). The chemical uptake
increased again at day 7 in all the exposure groups. That event could have been
caused by the increased metabolic rate of the embryos in preparation for the
upcoming hatching event. The microsomal CYP1A monooxygenase system (EROD) was
shown to be a sensitive indicator of embryonic exposure, being induced at the low
(1 microgram/l, 182 ng/g egg) PCB concentration and after a short (3 day)
exposure time. The conjugation enzyme system (GST) was shown to be functioning
already at the advanced embryonic stage, although no response to the studied
chemical stress was detected.
PMID- 10665415
TI - New PEC definitions for river basins applicable to GIS-based environmental
exposure assessment.
AB - By means of GREAT-ER (Geo-Referenced Regional Exposure Assessment Tool for
European Rivers) aquatic chemical fate simulations can be performed for river
basins. To apply the resulting digital maps with local (river stretch specific)
predicted concentrations in regional aquatic exposure and risk assessment, the
output has to be aggregated to a (single) value representative of exposure in the
catchment. Two spatially aggregated PEC definitions are proposed for this
purpose: PECinitial (unweighted aggregation of concentrations just downstream of
wastewater emissions) and PECcatchment (weighted aggregation of all average
stretch concentrations). These PECs were tested using simulations for two pilot
study catchments (Calder and Went, UK). This confirmed the theoretical
considerations which led to the definitions, and it illustrated the need for
weighting to resolve scale-dependencies.
PMID- 10665416
TI - Evaluation of PNEC values: extrapolation from Microtox, algae, daphnid, and fish
data to HC5.
AB - In order to evaluate the risk to the environment from long term exposure of any
discharged substance, toxicity thresholds are estimated, and particularly the
Predicted No Effect Concentration (PNEC). This concentration can be estimated by
the classic assessment factor approach or by statistical methods. These are more
scientifically sound but they require several (at least 5-6) chronic ecotoxicity
data, implying greater cost and time. New extrapolation methods derived from the
statistical concept but requiring less data have been studied. Results show that
methods based on chronic data are more reliable than methods based on acute data
but the improvement is quite small. Considering the costs of chronic tests
compared to acute tests, approaches based on acute data are an attractive
alternative. A simple regression on the mean of the acute data gives the best
results.
PMID- 10665417
TI - Growing snails used as sentinels to evaluate terrestrial environment
contamination by trace elements.
AB - Young garden snails (Helix aspersa) reared in standard conditions (aged two
months, mean weight 4.6 +/- 0.5 g) set as sentinels in cages laid on the soil for
four weeks, give data for biomonitoring the environmental impact of chemicals on
soil ecosystems in the field. The survival and the growth of the snails are
influenced by the nature of the biotope and the level of the pollutants. Assay of
cadmium, copper, lead and zinc bioaccumulated in the tissues of the sentinel
snails provides information on the bioavailability of metals in the environment.
The encagement model, little used for terrestrial species, can be useful in
monitoring (specific and global endpoints) metal pollution of the environment in
reference to the trophic level of the primary consumers. Active biomonitoring is
positively compared with the passive biomonitoring.
PMID- 10665418
TI - Atrazine induction of cytochrome P450 in Chironomus tentans larvae.
AB - Cytochrome P450-dependent aldrin epoxidation was characterized in third instar
larvae of the aquatic midge, Chironomus tentans. Optimal in vitro assay
conditions for the epoxidase were pH 7.6 and 31 degrees C. Activity was linear up
to 40 min of incubation time and 0.5 mg microsomal protein per incubation. The
activity was concentrated in the microsomal fraction of whole body homogenates
and was NADPH-dependent. The effect of atrazine exposure on aldrin epoxidase was
measured to determine if this herbicide induces cytochrome P450-dependent
activity. Comparisons of control and atrazine-exposed midges indicated increased
epoxidase activity as a result of atrazine exposure, and a 45 kDa protein of
increased intensity was observed after SDS-PAGE of microsomal protein. The
molecular weight of this protein was similar in size to cytochrome P450 enzymes
reported for other insects. Heme staining of SDS-PAGE gels and immunochemical
studies using a Drosophila melanogaster anti-P450 polyclonal antiserum, further
support the cytochrome P450 nature of this inducible 45 kDa protein.
PMID- 10665419
TI - PAHs analysis of fish whole gall bladders and livers from the Natural Reserve of
Camargue by GC/MS.
AB - Traces of parent polycyclic aromatic hydrocarbons (PAH) in fish whole gall
bladders and livers from the Natural Reserve of Camargue were determined from
three different species: cels, goldfishes and catfishes by capillary gas
chromatography-mass spectrometry (GC/MS) after Soxhlet extraction and florisil
column cleanup. Results have been successfully correlated with biological fish
parameters in order to identify adequate biomarkers of PAHs contamination.
PMID- 10665420
TI - Piperonyl butoxide potentiates the synaptosome ATPase inhibiting effect of
pyrethrin.
AB - Pyrethrins are widely used insecticides in both agriculture and households. In
many commercial formulations piperonyl butoxide (PBO) is used with pyrethrins.
PBO is a well-known synergist of pyrethrins, used to intensify their effects. One
of the cellular targets of pyrethrins is the sodium channel in the membrane. In
the present study, the activity of the membrane-bound integral protein ATPase was
studied as a biomarker for the membrane effects of pyrethrin and PBO. Cerebral
synaptosomes of rat brain were used in the study. The isolation of synaptosomes
was performed with the Percoll gradient method. Both total ATPase and Mg2+
activated ATPase were studied by determining inorganic phosphate. Exposure to 0.1
1000 microM of pyrethrin and to 0.4-4000 microM of PBO decreased ATPase activity
dose-dependently. The most efficient mixture was the one consisting of one part
of pyrethrin and four parts of PBO. The activity of total ATPase decreased 15% in
concentrations of 0.1-10 microM pyrethrin, and a 50% decrease was found at 100
microM pyrethrin. The mixture of pyrethrin and PBO caused a 15-60% decrease in
the total ATPase activity at 0.1-10 microM pyrethrin and 0.4-40 microM PBO. A 85%
decrease was found after exposure to the mixture of 100 microM pyrethrin and 400
microM PBO. PBO alone had no effect at 0.4-40 microM concentrations, but a marked
effect was seen at over 40 microM concentrations. The results indicate that PBO
is an effective synergist of pyrethrin and that it is very toxic in high
concentrations. The results also confirm that neuronal sodium homeostasis is one
target of the neurotoxic effect of pyrethroid compounds.
PMID- 10665421
TI - Cytogenetic changes in subjects occupationally exposed to benzene.
AB - Humans are exposed to benzene from various occupational and environmental
sources. The genotoxic effects of benzene were assessed in peripheral blood
lymphocytes of 36 workers employed in the shoe industry for a period extending
from seven months to over 30 years. Chromosomal aberrations and sister chromatide
exchanges were used as indicators of genotoxic effects. The incidence of
dicentric chromosomes in the exposed group was significantly higher than in the
control group (P < 0.05). No significant increase was detected between the
working period in the exposed group and chromosomal aberrations. Sister
chromatide exchange (SCE) frequency was not significantly increased in the
exposed group.
PMID- 10665423
TI - The effect of EDTA and fulvic acid on Cd, Zn, and Cu toxicity to a bioluminescent
construct (pUCD607) of Escherichia coli.
AB - The hypothesis, that metal toxicity is dominated by free ion activity, was tested
by comparing calculated metal activities with measured toxic responses to a
genetically modified, luminescent bacterium, Escherichia coli. The toxicity of
Cd, Cu, and Zn sulphate salts in the presence of EDTA and fulvic acid in well
defined solutions was measured. Good agreement between free metal activity and
toxicity was found for Cu but not for Zn and Cd. The toxicity relationships were
altered by glucose addition to the organism. Stable chloride complexes may have
contributed to the toxicity of Cd under the test conditions. The results suggest
that there is not always a simple relationship between toxicity and free-ion
metal concentration and that further account should be taken of competitive
interactions between living cells and ligands and the physiological status of the
organism.
PMID- 10665422
TI - Biochemical responses of the mycorrhizae in Pinus massoniana to combined effects
of Al, Ca and low pH.
AB - Biochemical responses of Pinus massoniana, with and without the inoculation
mycorrhizal fungus Pisolithus tinctorius at the root, to artificial acid rain (pH
2.0) and various Ca/Al ratios were investigated. Some enzymes associated with the
nutritive metabolism, such as acid phosphatase, alkaline phosphatase, nitrate
reductase, mannitol dehydrogenase and trehalase, in the roots, stems and leaves
of plant were obviously inhibited by the artificial acid rain and Al. After
treatment with pH 2.0 + Ca/Al (0/1 or 1/10) artificial acid rain, the protein
content in the organs was decreased. However, the activities of superoxide
dismutase (SOD) and peroxidase (POD) and glutathione (GSH) concentrations were
induced. It demonstrated that acid rain and Al could induce oxygen radicals in
plant. Compared with the treatments with lower pH or Al, respectively, the
combination of lower pH and Al concentration was more toxic to P. massoniana. Al
toxicity could be ameliorated by the addition of Ca and the amelioration was the
most when the ratio was 1/1 among the various Ca/Al ratio. Infection with
mycorrhizal fungus P. tinctorius at the root of P. massoniana increased the
ability of the plant to resist the toxicity of artificial acid rain and Al
stress.
PMID- 10665424
TI - Contribution of membrane surface charge in the interaction of lead and tin
derivatives with model lipid membrane.
AB - The objective of this study was to determine the interaction of modified bilayer
lipid membranes (BLMs) with lead and tin organoderivatives. The relative
depolarization, of the lipid membrane, caused by organo metals, was used to
estimate their activity. Dodecyltrimethylammonium bromide (TMDA) and sodium
dodecylsulfonate (AS-12) were used to modify BLMs. The trialkylderivatives of tin
(IV) were found to be the most active towards the lipid membrane, whereas
dialkyltin (IV) and trialkyllead (IV) derivatives were less active. Also, a
correlation exists between depolarization activity and the lipophilicity of
organo metal hydrolysis products. The surface charge of modified membranes had a
secondary influence on depolarization efficiency of the tin and lead derivatives.
PMID- 10665425
TI - Oxidation of chlorophenols with hydrogen peroxide in the presence of goethite.
AB - The use of goethite (alpha-FeOOH) and hydrogen peroxide was recently found that
they could effectively oxidize organic compounds. The study was to investigate
the effect of goethite particle size, goethite concentration, Fe2+ and Fe3+ on
the 2-chlorophenol oxidation. Results indicated that 2-chlorophenol can be
decomposed with hydrogen peroxide catalyzed by goethite and the oxidation rate
increased with decreasing goethite particle size. 2-Chlorophenol degradation was
almost retarded with 0.8 g/l of goethite because ferrous ions could not be
produced at this condition. Addition of Fe2+ and Fe3+ can enhance the catalytic
oxidation rate of 2-chlorophenol very efficiently. In conclusion, the main
mechanism of goethite catalyzing hydrogen peroxide to oxidize 2-chlorophenol may
be due to the catalysis of ferrous ions and goethite surface.
PMID- 10665426
TI - Prediction for thermodynamic function of dioxins for gas phase using semi
empirical molecular orbital method with PM3 Hamiltonian.
AB - In this investigation, respective thermodynamic parameters of heats of formation,
standard entropy and specific heat capacity at constant pressure for PCDDs,
PCDFs, Co-PCB and PCBs as well as polychlorinated-benzenes and polychlorinated
phenols have been evaluated by quantum chemical calculation using a semi
empirical molecular orbital method with the PM3 Hamiltonian and statistical
thermodynamic correlation.
PMID- 10665427
TI - Uptake rates of semipermeable membrane devices (SPMDs) for PCDDs, PCDFs and PCBs
in water and sediment.
AB - Uptake rates of several PCDDs, PCDFs and PCBs were measured for semipermeable
membrane devices (SPMDs) under controlled conditions in bulk water and sediment.
The study was performed at 19 degrees C and 11 degrees C, and water and sediment
concentrations were measured during the exposure. Linear uptake rates for
specific PCDD/Fs and PCBs in 19 degrees C water varied from 34 to 111 l/m2 day
and in 11 degrees C water from 8.8 to 96 l/m2 day for the whole SPMD. Uptake
rates at 19 degrees C sediment ranged from 9.0 to 80 mgOC/m2 day and in 11
degrees C sediment, from 3.0 to 31, mgOC/m2 day. Partitioning of the compounds
between membrane and lipid was also measured during the linear uptake phase. The
membrane-lipid concentration ratios ranged from 0.02 to 1.11 depending on the
compound, temperature, and bulk medium.
PMID- 10665428
TI - The effects of temperature and oxygen content on the PCDD/PCDFs formation in MSW
fly ash.
AB - In this study, the effects of the temperature, oxygen content in the gas stream
and carbon content in ash particles on PCDD/Fs formation on the fly ash surface
were investigated. The optimum temperatures for dioxin formation were found at
350 degrees C for boiler ash, 300 degrees C for cyclone ash and 250 degrees C for
ESP ash, respectively. Preliminary results indicate that the optimum temperature
will decrease as the particle size decreases. When the O2 concentration is varied
between 0% and 100%, the optimum oxygen content for PCDD/Fs formation is found to
be at 7.5% for cyclone ash, and the PCDD/PCDF ratio increases with the increase
of oxygen content. Dioxin formation is observed even for the gas containing no
oxygen passed through the fly ash. Hence, other reacted routes that do not need
O2 for dioxin formation take place on fly ash. The carbon content in fly ash is
varied between 0% and 20% in this study, and the results have indicated that the
maximum dioxin formation is to be found at 5%. The precursors are not injected
into the fly ash or gas stream in all formation experiments, however, dioxin is
still formed in fly ash. Consequently, other chlorinated routes besides Deacon
reactions may take place on the fly ash surface.
PMID- 10665429
TI - Estimation of dioxin emission from fires in chemicals.
AB - The formation of the 17 toxic 2,3,7,8-substituted PCDDs and PCDFs during
combustion of selected chemicals were measured by high-resolution GC/MS. The 16
chemicals studied were commonly used chlorinated pesticides, industrial
chemicals, and PVC. In a series of experiments carried out in a DIN 53,436
furnace, 2.5 g of these compounds were burned at 500 degrees C and 900 degrees C,
respectively. The resultant yields ranged from 740 ng ITEQ/g for
pentachlorophenol, to below 0.01 ng ITEQ/g for PVC and dichlobenil. The results
show that some chemicals generate PCDD/F in very high--possibly dangerous-
amounts during burning, whereas others generate insignificant amounts. The
influence of scale were studied for chlorobenzene and 4-chloro-3-nitro-benzoic
acid in additional experiments, carried out in a cone calorimeter burning 20 g
substance, and in ISO 9705 room test burning about 50 kg. A good agreement
between the results for large and small scale indicated that formation of PCCD/F
during a fire may be estimated from laboratory experiments. This suggest
laboratory test may be used to screen for chemicals posing a hazard for release
of PCDD/F during fires.
PMID- 10665430
TI - Assessment of human health risk of dioxins in Japan.
AB - The human health risk of dioxins was evaluated for four Japanese receptor groups:
the general population, local residents living near a municipal solid waste
incinerator, heavy fish consumers, and their infants and fetuses. In describing
the risk for these groups, four endpoints, namely, cancer, reproductive
dysfunction, endometriosis and neurobehavioral effect, were considered, and the
incremental cancer risk and margin of exposure (MOE) corresponding to these
endpoints were calculated, based on three measures of dosimetry; average daily
intake, area under the curve, and body burden. The uncertainties of these risk
descriptors were also evaluated by probabilistic analysis. Although the estimated
risk of cancer and reproductive dysfunction were not exceptionally high in the
three adult receptor groups, the MOE values for endometriosis were not
sufficiently high to guarantee safety against this endpoint. Furthermore, the MOE
values for neurobehavioral effects on infants and fetuses suggest that dioxins
may cause a considerable risk to those of local residents and heavy fish
consumers.
PMID- 10665431
TI - Extraction of polychlorinated dibenzo-p-dioxins and dibenzofurans from solid
samples using the Randall technique.
AB - This study deals with a new sample extraction technique which minimizes pollution
in analytical laboratories whilst reducing sample preparation time and cost. The
device uses the Randall technique for solid sample extraction, performed by
immersion of the sample in boiling solvent. The fast solubilization operated by
the hot solvent leads to a sharp reduction in extraction time. This method was
tested for the extraction of polychlorinated dibenzo-p-dioxins (PCDDs) and
dibenzofurans (PCDFs) from different solid matrices using toluene as extractant,
and compared with the conventional Soxhlet. The reduction in the extraction times
(from 48 to 2 h) with an efficiency similar to or higher than that afforded by
the conventional Soxhlet technique indicates the suitability of this method.
PMID- 10665432
TI - On the possible role of acetylene in gas-phase dioxin formation.
AB - The slow combustion of benzene/phenol gives rise to dibenzofuran (DBF) as major
product of incomplete combustion, with negligible proportions of dibenzo-p-dioxin
(DBD), or benzofuran (BF). Contrary to a recent proposal that acetylene growth
reactions, e.g. BF-->DBF, are important in dioxin formation, co-combustion of
benzene/phenol with acetylene--around 550 degrees C--did not alter this product
pattern. Also, BF was identified as a product from degradation of DBF.
PMID- 10665433
TI - Studies of toxaphene in technical standard and extracts of background air samples
(Point Petre, Ontario) using multidimensional gas chromatography-electron capture
detection (MDGC-ECD).
AB - MDGC-ECD procedures have been used to provide insight into the compositional
complexity of some of the specific peaks or clusters observed in the gas
chromatographic analysis of a technical toxaphene standard, with reference to
individual toxaphene congeners (Parlar # components) that are flow commercially
available. These investigations have focussed initially upon those peaks and
clusters recently identified (Shoeib. M., Brice, K.A., Hoff, R., 1999.
Chemosphere 39, 849-871) as dominant constituents of background ambient air.
Multiple electron-capturing components have been found to be present in all the
species studied: the available individual toxaphene congeners have been matched
against these components where possible. In similar fashion, the responses
obtained in equivalent gas chromatographic elution windows from the analysis of
typical processed air sample extracts have been investigated, with the results
showing clear differences relative to the patterns found in the technical
toxaphene standard. In most cases, the air sample shows reduced complexity with
fewer components present in the cluster. Also, the presence of interfering
responses (due to PCBs and other organochlorines) is quite apparent and
significant, showing that major problems and errors could arise when using single
column GC-ECD procedures for quantitation of toxaphene in environmental samples.
The presence of certain of the Parlar species in the air samples has been
confirmed and in most cases these represent the dominant toxaphene component
found in the targeted cluster. Furthermore, the persistence of certain congeners
in the atmospheric samples appears to be strongly dependent upon chemical
structure, since the congeners in question possess an alternating exo-endo
chlorine substitution pattern around the six-membered ring in the bornane
skeleton. Such persistence is probably the result of lower metabolization of
toxaphene residues in soils, water and sediments leading to a similar pattern in
the atmosphere following volatilization.
PMID- 10665434
TI - Application of GC-MS/MS for the analysis of PCDD/Fs in sewage effluents.
AB - The application of high resolution gas chromatography in combination with tandem
mass spectrometry in an ion trap was tested to substitute the expensive high
resolution mass spectrometry in analysing polychlorinated dibenzo-p-dioxins and
furans in sewage effluents. In tandem mass spectrometry, a set of parameters has
to be optimised in order to attain the required sensitivity. To the best of our
knowledge, this is the first time a method development for analysing PCDD/Fs with
GC-MS/MS in an ion trap is described in this detail. Nine parameters are varied,
including isolation window, collision induced dissociation (CID) amplitude, CID
time, acquisition mass range, broadband amplitude, CID bandwidth, modulation
range, filament current and ion trap temperature. This technique can be adapted
to other analytes. By this optimisation, limits of detection of 0.01-0.05 ng/l
are obtained. With its selectivity and sensitivity, tandem mass spectrometry is a
powerful tool for the determination of PCDD/Fs in water samples. 55 sewage
effluent samples from Germany were analysed.
PMID- 10665435
TI - The concentration and distribution of 2,3,7,8-dibenzo-p-dioxins/-furans in
chickens.
AB - The concentrations of the 2,3,7,8-Cl substituted dibenzo-p-dioxins/-furans
(PCDDs/PCDFs) were determined in the edible tissues of whole chicken fryers and
compared with the values found in their abdominal fat. The values are presented
both on a whole weight basis and on a lipid adjusted basis for each tissue. While
there is a marked difference in the concentration of the 2,3,7,8-dibenzo-p
dioxins in the edible tissues expressed on a whole weight basis, the lipid
adjusted concentrations of the individual dioxins were not statistically
different in the various tissues. This validates the use of lipid adjusted
concentrations of 2,3,7,8-PCDDs/PCDFs in abdominal fat for the determination of
the presence of these compounds in different tissues.
PMID- 10665436
TI - PCDD/PCDF emissions from small firing systems in households.
AB - This report presents results of emission measurements of polychlorinated dibenzo
p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in the flue gas of
seven oil, nine gas, and two wood firing systems under laboratory conditions. The
burn rate of the combustion was in the range of the rated useful heat output. Two
additional test series varied the amount of combustion air and thus the heat
output. The PCDD/PCDF emissions for oil- and gas-fired boilers are in the range
of 0.0020-0.0142 ng I-TEQ/m3 (referring to 3% O2 in the dry flue gas). No
correlation between the combustion technique and the PCDD/PCDF emissions could be
established. In the tests with the wood-fired furnaces PCDD/PCDF concentrations
in the flue gas ranging from 0.014 to 0.076 ng I-TEQ/m3 (referring to 13% O2 in
the dry flue gas) were found. A significant correlation between the firing rate
of the heating insert and the measured PCDD/PCDF concentrations was found. On
examination of three typical 2,3,7,8-CDD/CDF congener profiles, a comparable
pattern could be observed with natural gas and light fuel oil. The congener
distribution for wood combustion is considerably different.
PMID- 10665437
TI - Sorption-desorption behaviour of 2,4-dichlorophenol by marine sediments.
AB - Batch kinetic and isotherm experiments were conducted to determine the sorption
desorption behavior of 2,4-dichlorophenol from seawater solutions by marine
sediments containing various amounts of organic carbon (from 1.02% to 12.72% dry
weight). The results indicated linear type isotherms for sorption and desorption
in all marine sediments studied. The observed difference in linear sorption
coefficients between sorption and desorption was indicative of sorption
hysteresis. The kinetic experiments showed that equilibrium was established in
less than 20 h. The study is significant with respect to sediment remediation in
contaminated harbors and coastal areas.
PMID- 10665438
TI - Plant-promoted pyrene degradation in soil.
AB - A study was conducted to investigate the capability of nine plant species to
promote the degradation of pyrene in soil. The test method allowed for analysis
of the entire sample of soil. More pyrene was degraded in the presence of roots
of all nine species than in unplanted soil. Within approximately 8 weeks, as much
as 74% of the pyrene disappeared from vegetated soil compared to 40% or less from
unplanted soil. The data suggest that some of the test species may be especially
useful for phytoremediation of soils contaminated with PAHs.
PMID- 10665439
TI - Accumulation of phenanthrene and pyrene in rhizosphere soil.
AB - A study was conducted to determine PAH concentrations in the rhizosphere of
plants grown in soil containing phenanthrene or pyrene. The rhizosphere of tall
fescue and wheat grown in sterile soil contained 4-5-fold higher pyrene
concentrations than unplanted soil. The rhizosphere of several plant species
grown in non-sterile soil temporarily contained appreciably more phenanthrene or
pyrene than unplanted soil, but those PAHs were degraded with time. The data
suggest that plants accumulate such hydrophobic compounds in the rhizosphere
after facilitating their transport toward the roots.
PMID- 10665440
TI - Mineralization of organic micropollutants (homologous alcohols and phenols) in
water by vacuum-UV-oxidation (H2O-VUV) with an incoherent xenon-excimer lamp at
172 nm.
AB - Twenty different organic micropollutants (for example C1-C8 homologous alcohols
and some phenols) in aqueous solution were subjected to vacuum-UV-oxidation (H2O
VUV) within a xenon-excimer flow-through photoreactor. The incoherent xenon
excimer lamp used exhibited an emission maximum at 172 nm. At this wavelength
water is efficiently photolyzed with formation of hydrogen atoms and of highly
oxidative hydroxyl radicals. The short lived hydroxyl radicals initiate a series
of complex interrelated radical reactions that lead finally to the mineralization
of the organic material dissolved in water. The efficiency of the total organic
carbon (TOC) diminution is dependent on the nature of the organic substrate
treated. For example, in the series of homologous alcohols the substrate methanol
is mineralized faster than 1-octanol by a factor of 2.7 under identical
conditions of VUV treatment and with similar initial TOC content of the water
ranging between 40 and 50 ppm.
PMID- 10665441
TI - Assessment of the bioavailability of rare earth elements in soils by chemical
fractionation and multiple regression analysis.
AB - The bioavailability of rare earth elements (REEs) in soils was evaluated, based
on the combination of chemical fractionation and multiple regression analysis.
REEs in soils were partitioned by a sequential extraction procedure into water
soluble (F(ws)), exchangeable (F(ec)), bound to carbonates (F(cb)), bound to
organic matter (F(om)), bound to Fe-Mn oxides (F(fm)) and residual (F(rd))
fractions. Alfalfa (Medicago Staiva Linn.) had been grown on the soils in a pot
culture experiment under greenhouse conditions for 35 days. The concentrations of
REEs in fractions and plant were determined by inductively coupled plasma-mass
spectrometry (ICP-MS). Chemical fractionation showed that (F(ws)) fraction of
REEs was less than 0.1% and residual (F(rd)) was the dominant form, more than 60%
in soils. Bioaccumulation of REEs was observed in Alfalfa. REE availability to
the plant was evaluated by multiple regression analysis. F(ws), F(ec), F(cb) and
F(om) fractions were significantly correlated with REE uptake by alfalfa. But the
exchangeable Pr(F(ec)) was significantly correlated with Pr concentration in
alfalfa. F(ec), F(cb) and F(om) greatly contributed to La and Nd bioavailability;
F(ec) and F(om) to Ce, Gd and Dy; F(ec) and F(cb) to Yb; and F(ws), F(ec) and
F(om) to total REEs. This meant that the bioavailability of different species of
REEs varied with individual REE. The results of this study indicated that the
sequential extraction procedure, in conjunction with multiple regression
analysis, may be useful for the prediction of plant uptake of REEs from soils.
PMID- 10665442
TI - Determination of selected fate and aquatic toxicity characteristics of acrylic
acid and a series of acrylic esters.
AB - Acrylic acid, methyl acrylate, ethyl acrylate, and butyl acrylate are
commercially important and widely used materials. This paper reports the results
of a series of fate and aquatic toxicity studies. The mobility in soil of acrylic
acid and its esters ranged from 'medium' to 'very high'. Calculated
bioconcentration factors ranged from 1 to 37, suggesting a low bioconcentration
potential. Acrylic acid and methyl acrylate showed limited biodegradability in
the five day biochemical oxygen demand (BOD5) test, while ethyl acrylate and
butyl acrylate were degraded easily (77% and 56%, respectively). Using the OECD
method 301D 28-d closed bottle test, degradability for acrylic acid was 81% at 28
days, while the acrylic esters ranged from 57% to 60%. Acrylic acid degraded
rapidly to carbon dioxide in soil (t1/2 < 1 day). Toxicity tests were conducted
using freshwater and marine fish, invertebrates, and algae. Acrylic acid effect
concentrations for fish and invertebrates ranged from 27 to 236 mg/l. Effect
concentrations (LC50 or EC50) for fish and invertebrates using methyl acrylate,
ethyl acrylate, and butyl acrylate ranged from 1.1 to 8.2 mg/l. The chronic MATC
for acrylic acid with Daphnia magna was 27 mg/l based on length and young
produced per adult reproduction day and for ethyl acrylate was 0.29 mg/l based on
both the reproductive and growth endpoints. Overall these studies show that
acrylic acid and the acrylic esters studied can rapidly biodegrade, have a low
potential for persistence or bioaccumulation in the environment, and have low to
moderate toxicity.
PMID- 10665443
TI - Analysis of volatile organic compounds, using the purge and trap injector coupled
to a gas chromatograph/ion-trap mass spectrometer: review of the results in Dutch
surface water of the Rhine, Meuse, Northern Delta Area and Westerscheldt, over
the period 1992-1997.
AB - Volatile organic compounds are widely introduced into the Dutch aquatic
environment. Liquid-liquid extraction and isolation by means of resins give poor
recoveries for volatiles. In this study, a method has been developed to analyse
these compounds with a purge and trap injection (PTI) coupled to a
chromatograph/ion trap mass spectrometer. Volatile compounds are "purged" from
the sample by carrier gas flow and transported through a condenser to a cooled
trap. The bulk of liquid matrix is condensed in the condenser, while volatile
compounds are left unaffected. The compounds of interest are trapped at a low
temperature, by liquid nitrogen in the cooled trap of fused silica. Injection
takes place by flash heating of the trap. The detection limits of the volatile
compounds are in the range of 0.001-0.04 microgram l-1, in full spectrum mode. In
this paper a review of the results in Dutch surface water of the Rhine, Meuse,
Northern Delta Area and Westerscheldt, over the period 1992-1997, is presented.
For calamities causing high levels of volatiles, the method is very useful. The
compounds can be monitored over a certain period. In the Meuse, high levels of
volatile organic compounds are observed. Diisopropyl ether at a maximum of 592
micrograms l-1.
PMID- 10665444
TI - Adsorption/thermal desorption-GC/MS for the analysis of pesticides in the
atmosphere.
AB - An analytical methodology using Automatic Thermal Desorption (ATD) and GC/MS was
developed for the determination of the pesticides alachlor, atrazine, captan,
formothion, lindane and phosalone in atmospheric samples. This methodology was
developed to evaluate the atmospheric contamination by pesticides during
treatments and by post-application. Atmospheric samples were collected by using
(4 i.d. x 89 mm) stainless steel sampling tubes containing 125 mg of adsorbents
at a flow rate of 80 ml min-1. Different types of adsorbents were tested for
their ability to efficiently trap pesticides under study: Tenax TA, Carbopack Y,
Carbopack B, Carbotrap, Carboxen, Chromosorb 106 and XAD-4. Results of experiment
show that Tenax gives the better results for all the pesticides used but the use
of the thermal-desorption method, especially for pesticides with low volatility
and/or poor thermal stability presents some difficulties. This method was
validated by the analysis of the contamination of atmosphere, through
volatilization by post-application processes, of atrazine in a parcel of 1 ha.
PMID- 10665445
TI - The concentration, apparent molecular weight and chemical reactivity of silica
from groundwater in southern Nevada.
AB - Sorption of radionuclides, metals and organic compounds to colloidal particles
has been suggested to increase the mobility of these pollutants in groundwater.
Because silicates and alumino-silicates can be important components of
groundwater colloids, we have conducted a study to characterize the nature of
silica in various springs and wells in Southern Nevada and to determine the
extent that silica may be associated with colloidal particles that can
participate in pollutant transport. The total silica content was measured using
inductively coupled plasma emission spectroscopy (ICP). In addition, reactive
silica was measured using the silica molybdate colorimetric technique. The
apparent molecular weight of the silica was investigated using split-flow-lateral
transport-thin-cell-fractionation (SPLITT) which can readily distinguish between
colloidal and low molecular weight associations. This study indicates that silica
does not tend to form stable inorganic colloids in Southern Nevada groundwaters
but exists as low molecular weight species. However, water from one of the test
facilities on the Nevada Test Site (NTS) did contain stable siliceous colloids
that could have important implications for the modeling the transport of
radionuclides at this site.
PMID- 10665446
TI - Metal contents of fish from cultureponds near scrap metal reclamation facilities.
AB - Milkfish (Chanos chanos) from four fish-culture ponds adjacent to different metal
recovery facilities along the Er-Jen River area, Tainan, Taiwan, were sampled to
determine their metal contents. Chemical analysis showed that fish tissue
contained different concentrations of Cu: 0.71-6.37 micrograms/g, Pb: ND (not
detectable) approximately 41.04 micrograms/g, Cd: ND approximately 0.41
microgram/g, Al: 6.75-64.11 micrograms/g, Ni: 0.062-0.504 microgram/g and Zn:
16.11-41.86 micrograms/g. The average concentrations of Cu, Al, Zn, Cd and Pb in
fish samples from some of the ponds were significantly higher than those from the
reference pond. In addition, there were variations in metal concentrations of
fish collected from different ponds. Pond D had the highest mean values of Cu, Cd
and Zn, and Pond B of Al and Pb. Further investigations are needed to determine
the source of metal contamination in the fish.
PMID- 10665447
TI - Determination of nitrate and other water quality parameters in groundwater from
UV/Vis spectra employing partial least squares regression.
AB - The use of UV/Vis spectroscopy in combination with partial least squares (PLS)
regression for the simultaneous prediction of nitrate and non-purgeable organic
carbon (NPOC) in groundwaters was evaluated. A model of high quality was obtained
using first order derivative spectra in the range 200-300 nm. Inclusion of non-UV
absorbing constituents in the modeling procedure, i.e., chloride, sulfate,
fluoride, total carbon (TC), inorganic carbon (IC), alkalinity, pH and
conductivity was also evaluated. This model seemed to be useful for prediction of
chloride, TC, IC, alkalinity and conductivity, while its ability to predict
sulfate, fluoride and pH was poor. In conclusion, application of PLS regression,
which requires neither filtration of samples nor addition of chemicals, is a
promising alternative for fast interpretation of geochemical patterns of
groundwater quality.
PMID- 10665448
TI - Prediction of pesticide concentrations in the atmosphere using an atmospheric
diffusion model (linear source plume model).
AB - The foundational model to predict concentration of pesticides in the atmosphere
outside of the sprayed area was developed using the results of measured
concentration in the atmosphere, in reference to the atmospheric diffusion model
utilized for the air pollution prediction model. The atmospheric diffusion model
assumes that the applied area was a topographically flat farmland, that wind
direction and wind speeds were constant, and the pesticide was constantly
discharged from the emission line sources. Therefore the linear source plume
model (LSPLM) was developed. The concentration in the atmosphere was predicted by
assigning the property of the pesticides and various conditions of measurements
of the model, and compared with the measured them, then the adaptability of the
model was examined. As a result, the correlation between the measured value and
the predicted value in paddy and forested areas was significant (P < 0.01)
although deviations in the order of tens were observed, the measured value and
the predicted value were generally in agreement.
PMID- 10665449
TI - Fungal degradation of fluorene.
AB - A selection of 30 strains of micromycetes known as good degraders of
polychlorinated aromatic compounds, mostly isolated from soil and belonging to
various taxonomic groups, have been investigated to degrade fluorene. Toxicity
assays, first evaluated on solid media, have shown high growth inhibition at
concentrations above 0.001 g l-1 only towards 23% of strains. Degradation of
fluorene (0.005 g l-1) was then investigated in liquid synthetic medium for 2
days and evaluated by HPLC. Among the 30 strains tested, 12 could be considered
as best degraders because of a rate of degradation at 60% or over. 3 strains of
Cunninghamella genus were very efficient (mean of degradation: 96%) but different
strains from Ascomycetes. Basidiomycetes and Deuteromycetes were also efficient
11 strains are not yet reported in the literature: Aspergillus terreus,
Bjerkandera adusta, Ceriporiopsis subvermispora, Colletotrichum dematium,
Cryphonectria parasitica, Cunninghamella blakesleeana, C. echinulata, Drechslera
spicifera, Embellisia annulata, Rhizoctonia solani and Sporormiella australis. A
metabolic approach with standard compounds (9-fluorenol and 9-fluorenone)
indicated the presence of these monooxygenated derivatives for most of the
strains.
PMID- 10665450
TI - An analysis of the 'Modified Sturm Test' data.
AB - The 'Modified Sturm Test' uses carbon dioxide production as the primary end point
in assessing the biodegradation potential of organic chemicals. This test was
conducted by a commercial laboratory to assess the potential biodegradability of
an oil stabilizer sample from an oil company in Canada. There was a high
percentage conversion of total organic carbon present in the sample but carbon
dioxide measured was low. Many possibilities were analyzed in this paper in order
to understand the situation. The analysis showed that the test was subject to
criticism from the point of view of CO2 measurement, 10-day window period, and
aeration/mixing conditions.
PMID- 10665451
TI - Glyphosate adsorption on soils of different characteristics. Influence of copper
addition.
AB - Results of glyphosate (GPS) adsorption on three soils of different
characteristics show that the interaction of this pesticide with the soils was
not related to their CEC and clay minerals content, but to the content of iron
and aluminum amorphous oxides and organic matter. The presence of Cu in treatment
solutions enhanced GPS adsorption, due to several reasons: GPS coordinates
strongly to Cu, and Cu GPS complexes formed seem to have higher ability to be
adsorbed on the soil than free GPS; GPS adsorption can take place on sites where
Cu was previously adsorbed, acting as a bridge between the soil and GPS; when Cu
was present the solution pH decreased, and GPS adsorption increased, since lower
pHs lead to the formation of GPS species with lower negative charge, which are
adsorbed more easily on the negatively charged soil surfaces.
PMID- 10665452
TI - Benzene accumulation in horticultural crops.
AB - In this study apple, blackberry and cucumber crops were exposed to elevated
levels of benzene under controlled conditions. Benzene was retained in fruits of
all crops, but only accumulated in leaves of blackberries and apples. The
retention by cucumber fruits is suggested to result from the longer pathway for
the desorption of benzene as a consequence of their increased tissue depth
compared to leaves. The process of accumulation in blackberry and apple leaves is
unknown. The ingestion of benzene via the food-chain pathway on the basis of this
study is concluded not to be significant.
PMID- 10665453
TI - Photocatalytic degradation of lignin and lignin models, using titanium dioxide:
the role of the hydroxyl radical.
AB - The role of hydroxyl radicals on the degradation of lignins during a cellulosic
pulp bleaching process including a photocatalytic stage, was assessed using
peroxyformic acid lignins EL1 and REL1 and two phenolic niphenyl lignin models 1
and 2. The irradiations were performed in the absence of photocatalyst TiO2 and
H2O2 (condition a), in the presence of TiO2 (condition b) and in the presence of
H2O2 (condition c). The experiments were conducted in alkaline (pH approximately
11) aqueous ethanol solutions with oxygen bubbling. The relative phenolic content
of the irradiated solutions, which is indicative of the involvement of hydroxyl
radicals, was determined by ionization absorption spectroscopy. The results
obtained show that the catalyzed reaction involves both degradation of the
phenolate groups by electron transfer and hydroxylation of the lignin aromatic
structure. Benzyl alcohol structural elements in sodium borohydride reduced
lignin REL1 and compound 2 were also found as good trapping agents for the
hydroxyl radicals. The degradation of EL1 was studied by measuring its
fluorescence emission by comparison to the fluorescence of compound 2. The
emission spectra indicate that some biphenyl phenolate anions in EL1 are reacting
under UV/visible irradiation and some others, probably polyphenolic chromophores
emitting less fluorescence, are formed.
PMID- 10665454
TI - Outcomes in a referral cohort of patients with anxiety disorders.
AB - This study describes 6- and 12-month outcomes in a referral cohort with anxiety
disorders and identifies treatment and prognostic factors related to these
outcomes. Patients were recruited at three general hospital clinics, two
psychologist-run clinics, and one psychiatric hospital clinic. Outcomes included
severity of symptoms, physical and mental health status, and subjective global
change in problem severity. Of 254 patients eligible for follow-up, 165 (65.0%)
completed a follow-up questionnaire. Methods of treatment included consultation
with return to the primary care physician (38.2%); or continued treatment at the
clinic, with medications (16.4%), psychotherapy (22.4%), or both (23.0%). Both
severity of symptoms and mental health status improved but remained abnormal at
follow-up. In multiple logistic regression, subjective global improvement was
related to a diagnosis of panic disorder only, treatment with psychotherapy, and
type of referral. Change over time in symptom severity was related to clinic
type, and change over time in mental health was related to clinic type and
duration of previous treatment.
PMID- 10665455
TI - Affect regulation in alexithymia: an ethological study of displacement behavior
during psychiatric interviews.
AB - Displacement activities (i.e., self-directed behaviors such as self-touching,
scratching, and self-grooming) are a reliable ethological indicator of increased
emotional and physiological arousal throughout the phylogenetic scale. We
hypothesized that, in alexithymic individuals, the failure to regulate
cognitively distressing emotions might result in increased displacement behavior.
The nonverbal behavior of 30 patients with depressive or anxiety disorders was
video-recorded during psychiatric interviews and analyzed using an ethological
scoring system. Before being interviewed, each patient completed the Twenty-Item
Toronto Alexithymia Scale (TAS-20), the Beck Depression Inventory (BDI), and the
state form of the State-Trait Anxiety Index (STAI-S). Ethological data confirmed
the hypothesis of the study. The patients with more pronounced alexithymic
features showed a significantly higher frequency of displacement activities
during interviews. At the same time, these patients reported levels of self-rated
anxiety and depression equivalent to those reported by nonalexithymic patients.
Such a dissociation between cognitive appraisal of emotion and nonverbal behavior
reflecting increased emotional arousal supports the view that alexithymia implies
a failure to elevate emotions from a preconceptual level of organization to the
conceptual level of mental representations.
PMID- 10665456
TI - Parental style and vulnerability to depression: the role of core beliefs.
AB - This study considers the potential role of core beliefs (unconditional schema
level representations) in the relationship between recalled parenting in
childhood and major depression in adulthood, comparing a group of depressed
outpatients (N = 60) with a healthy community sample (N = 67). The depressed
group were differentiated by poorer perceived parenting (low care and high
overprotection) and by three unhealthy core beliefs (defectiveness/shame, self
sacrifice, and insufficient self-control). Among nonclinical participants, it
appears that vulnerability to harm beliefs act as a partial mediator of the
relationship between poor paternal care and the development of depressive
features. In contrast, a broader set of core beliefs appears to mediate the
relationship of maternal bonding and paternal overprotection with depressive
symptoms among the depressed group. The findings suggest that clinical work with
adults with major depression might need to take account of parental style. Where
parents are reported to be uncaring or overprotective, cognitive-behavioral
therapy might need to include a schema-focused component.
PMID- 10665457
TI - Risk factors associated with the dissociative experiences of borderline patients.
AB - The objective of this study was to identify the risk factors associated with the
dissociative symptomatology of borderline patients. The Dissociative Experiences
Scale--a 28-item self-report measure that has well documented reliability and
validity--was administered to 290 criteria-defined borderline patients and 72
axis II comparison subjects. Semistructured interviews pertaining to difficult
childhood experiences and adult experiences of being a victim of violence were
administered to these patients blind to diagnostic status. In the sample of
borderline patients alone, multiple regression analyses revealed that four risk
factors were found to be significantly associated with the level of dissociation
reported by these 290 patients: inconsistent treatment by a caretaker, sexual
abuse by a caretaker, witnessing sexual violence as a child, and adult rape
history. In the combined sample of axis II patients, the borderline diagnosis
joined these four "traumatic" factors as a significant predictor of the overall
level of dissociation reported by these 362 personality-disordered inpatients.
The results of this study suggest that both sexual trauma and something intrinsic
to the borderline diagnosis itself are risk factors for dissociative phenomena
among borderline patients.
PMID- 10665458
TI - Personality traits in schizophrenia: comparison with a community sample.
AB - The objective of this study was to compare personality trait profiles in patients
with schizophrenia and healthy controls. Male outpatients with schizophrenia (N =
24) and a male nonpsychiatric community sample (N = 46) completed the NEO-FFI
personality questionnaire. Multivariate analyses were used to compare mean scale
scores and scale profiles for each group. The overall personality profile of
clinically stable patients with schizophrenia differed significantly from that of
a community sample. On individual scales, patients scored significantly higher on
neuroticism and significantly lower on conscientiousness. These results confirm
and extend those of previous studies that used normative data for comparison and
a much longer version of the same personality questionnaire. Prospective studies
of populations at risk are needed to determine whether group differences reflect
a premorbid diathesis for schizophrenia or a secondary effect of serious mental
illness.
PMID- 10665459
TI - Research on religious variables in five major adolescent research journals: 1992
to 1996.
AB - A review of quantitative research studies published between 1992 and 1996 in five
major adolescent journals revealed that 11.8% (109 of 922) included a measure of
religion. This percentage (11.8%) is 3 to 10 times higher than that found in
previous reviews of empirical research in psychological and psychiatric journals,
suggesting that adolescent research journals are more sensitive to the role of
religious factors on mental health than research in related disciplines. The
results are discussed in the context and philosophy of the adolescent research
and in comparison with related disciplines.
PMID- 10665460
TI - Medically self-harming behavior and its relationship to borderline personality
symptoms and somatic preoccupation among internal medicine patients.
PMID- 10665461
TI - Caregiver burden in Shy-Drager syndrome.
PMID- 10665462
TI - Fluoxetine as an adjunct to conventional antipsychotic treatment of schizophrenia
patients with residual symptoms.
PMID- 10665463
TI - Sleep hygiene and sleep-onset insomnia.
PMID- 10665464
TI - Neuropsychiatric effects of insular stroke.
AB - The neuropsychiatric effects of insular damage in humans have not previously been
examined. We therefore examined the neuropsychiatric impairment in seven patients
with left insular stroke, six patients with right insular stroke, six patients
with left hemisphere noninsular stroke, and six patients with right hemisphere
noninsular stroke. Between 4 and 8 weeks after acute stroke, patients were
administered a neuropsychiatric battery. Patients with right insular lesions had
a greater frequency of subjective anergia and underactivity (Fisher's exact p =
.002) as well as tiredness (Fisher's exact p < .002) compared with patients with
non-insular lesions or left insular lesions. Subjective feelings of impaired
energy or drive after right insular damage may result from disconnection between
the insula and the frontal lobe or the anterior cingulate cortex, structures that
have been associated with willed action and motor behavior.
PMID- 10665465
TI - Dissociation in temporal lobe epilepsy and pseudo-epileptic seizure patients.
AB - Patients with epileptic seizures (ES) and especially those with temporal lobe
epilepsy (TLE) share many symptoms with patients with pseudo-epileptic seizures
(PES), and the differentiation between them is often difficult There is growing
evidence that a subgroup of PES patients suffer from a dissociative disorder. It
is recognized that dissociative symptoms pertain to both psychological and
somatoform components of experience. Questionnaires assessing dissociation might
provide positive criteria for the diagnosis of PES. In this study, the
Dissociation Questionnaire (DIS-Q) and the Somatoform Dissociation Questionnaire
(SDQ-20) were administered to patients with ES (TLE, non-TLE) and PES. To control
for the influence of general psychoneurotic complaints, the SCL-90 was
administered. Apart from this, answers on a trauma questionnaire were related to
the diagnosis. Results showed that PES patients scored significantly higher on
the SDQ-20, also after correction with the SCL-90, and no difference was found on
the DIS-Q. Also, PES patients significantly more often reported sexual traumatic
experiences. A logistic regression revealed that results on the SDQ-20 have no
independent value in addition to the contribution of gender, age, age at seizure
onset, and the presence of sexual abuse in the prediction of the diagnosis. In
conclusion, somatoform and not psychological dissociative symptoms are
characteristic for PES patients in comparison to ES patients. Other measures are
needed within the framework of the differential diagnosis between PES and ES.
PMID- 10665466
TI - Assessing clinical predictions of early rehospitalization in schizophrenia.
AB - This study determines patient characteristics that predict early hospital
readmission in schizophrenia and evaluates the extent to which inpatient staff
accurately predict these readmissions. Adult inpatients with schizophrenia or
schizoaffective disorder (N = 262) were evaluated at hospital discharge and 3
months later to assess hospital readmission. At hospital discharge, inpatient
staff were asked to identify which patients were likely to be readmitted during
this period. Comparisons were made between patients who were or were not
readmitted and between readmitted patients who were or were not identified by
staff as likely to be readmitted; 24.4% of the sample were readmitted within 3
months of hospital discharge. Early readmission was associated with four or more
previous hospitalizations (85.7% vs. 57.7%, p = .004), comorbid substance use
disorder (60.3% vs. 35.5%, p = .0006), major depression (40.6% vs. 26.8%, p =
.04), absence of a family meeting with inpatient staff (58.2% vs. 41.8%, p =
.02), and prescription of a conventional rather than an atypical antipsychotic
medication (93.7% vs. 83.8%, p = .045). Twelve of the 63 readmitted patients were
correctly predicted by staff to re-hospitalize. Staff tended to overestimate the
risk of rehospitalization in patients with a poor therapeutic alliance, low
global function, or initial involuntary admission and to underestimate the risk
in patients with alcohol use disorders or four or more previous psychiatric
hospitalizations. Early rehospitalization is common in schizophrenia and
difficult to predict. Greater emphasis on comorbid alcohol use disorders and a
history of multiple previous admissions may help clinicians identify patients at
greatest risk for early rehospitalization.
PMID- 10665467
TI - A specific attentional bias in suicide attempters.
AB - Selective attention in patients after an attempted suicide was investigated to
find out whether a specific attentional bias for suicide-related materials exists
and to clarify the possible role of emotions in the bias. Thirty-one patients who
had previously attempted to commit suicide and 31 control participants took part
in a modified Stroop task. The suicidal patients took significantly longer to
name the colors of suicide-related words compared with other words, whereas color
naming times of the control participants did not differ for suicide-related,
neutral, positive, or negative words. Therefore, the attentional bias exhibited
by suicidal patients was highly specific. There was no relation between the bias
and measures of anxiety, depression, or hopelessness, whereas suicidal ideation
correlated significantly with the attentional bias.
PMID- 10665468
TI - Core beliefs in anorexic and bulimic women.
AB - There is research evidence to suggest the presence of dysfunctional cognitions in
anorexia nervosa and bulimia nervosa that are not related to food, weight, or
shape. These maladaptive cognitions have not been addressed by the conventional
cognitive behavioral models of etiology or therapy. This study aimed to assess
the impact of unhealthy core beliefs on eating disorders and their symptoms.
Twenty restricting anorexics, 10 bulimic anorexics, 27 bulimics, and 23 normal
controls completed Young's Schema Questionnaire. Eating behaviors and attitudes
were also measured. The results indicate that both anorexic and bulimic women had
significantly higher levels of unhealthy core beliefs than comparison women, but
the clinical groups only differed on one individual core belief (entitlement).
However, there were different patterns of association between core beliefs and
eating psychopathology in anorexic and bulimic women. It is suggested that future
clinical practice should incorporate core beliefs as a potential element in the
assessment and treatment of eating disorders.
PMID- 10665469
TI - Lifetime severity index for cocaine use disorder (LSI-Cocaine): a predictor of
treatment outcomes.
AB - We developed a lifetime severity index for cocaine use disorder and examined its
predictive validity of posttreatment outcome using data from the national Drug
Abuse Treatment Outcome Study. The index, based on 28 items, considered frequency
of use, recency, dependency, and attempt to quit. A higher value of the index,
indicating greater severity, predicted a greater likelihood of relapse (the odds
ratios were 5.7 for high severity and 4.4 for medium severity, relative to low
severity) and shorter time to relapse. Similarly, the polytomous logistic
analysis indicated that the index predicted levels of posttreatment cocaine use
(odds ratios of daily use were 47.8 for the high severity and 18.8 for medium
severity; the corresponding odds ratios of weekly use were 6.75 and 5.10 and for
less-than-weekly use were 3.35 and 3.57). The index can be a useful measure for
both clinical and research purposes.
PMID- 10665470
TI - Unrecognized dissociation in psychotic outpatients and implications of ethnicity.
PMID- 10665471
TI - Traumatic stress and depression in a group of plane crash survivors.
PMID- 10665472
TI - Clinician response to treatment refractory panic disorder: a survey of
psychiatrists.
PMID- 10665473
TI - Does undergraduate education have an effect on Edinburgh medical students'
attitudes to psychiatry and psychiatric patients?
PMID- 10665474
TI - Inhibition of tumor growth and metastasis by targeting tumor-associated
angiogenesis with antagonists to the receptors of vascular endothelial growth
factor.
AB - Angiogenesis, the formation of new blood vessels, is essential for both tumor
growth and metastasis. Recent advances in our understanding of the molecular
mechanisms underlying the angiogenesis process and its regulation have led to the
discovery of a variety of pharmaceutical agents with anti-angiogenic activity.
The potential application of these angiogenesis inhibitors is currently under
intense clinical and pre-clinical investigation. Compelling evidence suggests
that vascular endothelial growth factor (VEGF) and its receptors play critical
roles in tumor-associated angiogenesis, and that they represent good targets for
therapeutic intervention. This has been demonstrated in a variety of animal tumor
models in which disabling the function of VEGF and its receptors was shown to
inhibit both tumor growth and metastasis. We have produced a panel of antibodies
directed against the VEGF receptor 2, KDR/F1k-1. These antibodies potently block
VEGF/KDR/F1k-1 interaction, and inhibit VEGF-stimulated activation of the
receptor and proliferation of human endothelial cells. Further, the antibodies
significantly inhibited tumor-associated angiogenesis in several animal models.
Antagonists of VEGF and/or its receptors may offer higher specificity towards
tumors with reduced side effects, and may be less likely to elicit drug
resistance compared to conventional therapy. Anti-angiogenesis therapy represents
a novel strategy for the treatment of cancer and other human disorders where
pathological angiogenesis is involved.
PMID- 10665475
TI - Tyrosine kinase inhibitors in preclinical development.
AB - Due to the limited efficacy of cytotoxic chemotherapy in the treatment of
advanced malignancy and its excessive toxicity precluding its use in
chemoprevention, new therapeutic and preventive strategies have been sought. One
of the most interesting of these new approaches is the manipulation of signal
transduction pathways. Among the approaches being considered to eventuate such a
strategy is the inhibition of autophosphorylation, a critical first step in the
signal transduction pathways of many cell surface receptor tyrosine kinases, as
well as of non-receptor tyrosine kinases. This article is intended to review
those tyrosine kinase inhibitors that are currently in preclinical development,
for which there are data to support consideration for their use in
chemoprevention or cancer treatment. We will focus upon those agents that have
received attention in the past several years.
PMID- 10665477
TI - Farnesyl protein transferase inhibitors and other therapies targeting the Ras
signal transduction pathway.
AB - The year 2000 will be a significant date for the field of Ras-related therapies
since numerous agents will have Phase II clinical efficacy data maturing to
provide proof of principle for this cancer treatment strategy. These data will
also provide an important milestone for the cancer research community since these
molecules represent a small vanguard of oncology drug discovery projects
predicated on molecular targets. We can only hope that these agents are a
successful harbinger for the formidable number of targeted therapies that will be
entering development pipelines in the coming years.
PMID- 10665478
TI - Epidermal growth factor receptor inhibition in cancer therapy: biology, rationale
and preliminary clinical results.
AB - The epidermal growth factor receptor (EGFR), a growth factor receptor involved in
the regulation of cellular differentiation and proliferation, is highly expressed
by many tumor cells. In light of a relationship between overexpression of EGFR
and clinically aggressive malignant disease, EGFR has emerged as a promising
target for cancer therapy. In recent years, several molecular strategies have
been explored to modulate either the EGFR itself, or the downstream signal beyond
the cell surface receptor. One of the most promising current strategies involves
the use of anti-EGFR monoclonal antibodies (mAbs), either alone or in combination
with conventional cytotoxic modalities such as chemotherapy or radiotherapy. This
review focuses primarily on recent progress in the development of anti-EGFR mAbs,
and examines their potential in the treatment of cancer.
PMID- 10665476
TI - Protein kinase C targeting in antineoplastic treatment strategies.
AB - Neoplastic cell survival is governed by a balance between pro-apoptotic and anti
apoptotic signals. Noteworthy among several anti-apoptotic signaling elements is
the protein kinase C (PKC) isoenzyme family, which mediates a central
cytoprotective effect in the regulation of cell survival. Activation of PKC, and
subsequent recruitment of numerous downstream elements such as the mitogen
activated protein kinase (MAPK) cascade, opposes initiation of the apoptotic cell
death program by diverse cytotoxic stimuli. The understanding that the lethal
actions of numerous antineoplastic agents are, in many instances, antagonized by
cytoprotective signaling systems has been an important stimulus for the
development of novel antineoplastic strategies. In this regard, inhibition of
PKC, which has been shown to initiate apoptosis in a variety of malignant cell
types, has recently been the focus of intense interest. Furthermore, there is
accumulating evidence that selective targeting of PKC may prove useful in
improving the therapeutic efficacy of established antineoplastic agents. Such
chemosensitizing strategies can involve either (a) direct inhibition of PKC
(e.g., following acute treatment with relatively specific inhibitors such as the
synthetic sphingoid base analog safingol, or the novel staurosporine derivatives
UCN-01 and CGP-41251) or (b) down-regulation (e.g., following chronic treatment
with the non-tumor-promoting PKC activator bryostatin 1). In preclinical model
systems, suppression of the cytoprotective function(s) of PKC potentiates the
activity of cytotoxic agents (e.g., cytarabine) as well as ionizing radiation,
and efforts to translate these findings into the clinical arena in humans are
currently underway. Although the PKC-driven cytoprotective signaling systems
affected by these treatments have not been definitively characterized,
interference with PKC activity has been associated with loss of the mitogen
activated protein kinase (MAPK) response. Accordingly, recent pre-clinical
studies have demonstrated that pharmacological disruption of the primary MEK-ERK
module can mimic the chemopotentiating and radiopotentiating actions of PKC
inhibition and/or down-regulation.
PMID- 10665479
TI - Antiandrogens in prostate cancer.
AB - Antiandrogens competitively inhibit ligand binding to the androgen receptor (AR),
and are used therapeutically in prostate cancer patients. The AR functions as a
ligand dependent transcription factor that transduces androgen binding into
increased transcription of androgen dependent genes. AR blockade induces
programmed cell death in the vast majority of malignant and benign prostate
cancer cells that have not previously been exposed to androgen ablation. The
antiandrogens are divided structurally into the steroidal and non steroidal
agents. The biological effects of the steroidal versus nonsteroidal agents are
distinguished by differences in their effects on serum testosterone levels, and
by their activity at receptors other than the androgen receptor. There is
extensive clinical experience in the palliative and curative therapy of prostate
cancer using antiandrogens as monotherapy or antiandrogens in combination with
luteinizing hormone agonists or surgical castration. Prolonged therapy with
antiandrogens selects for mutations in the AR that change the AR ligand
specificity and permits stimulation by ligands that are usually inhibitory. These
mutations give insight into one of the means by which prostate cancer progresses
despite antiandrogen therapy, and also helps to explain the antiandrogen
withdrawal syndrome. Areas of active research that may affect the future use of
antiandrogens include the ongoing evaluation of antiandrogens in combination with
5 alpha reductase inhibitors to achieve AR blockade without inducing castrate
testosterone levels. There is also interest in developing selective androgen
receptor modulators (SARM) that can achieve AR blockade without causing the
increased testosterone levels produced by the nonsteroidal antiandrogens
currently in use.
PMID- 10665481
TI - Flavopiridol: the first cyclin-dependent kinase inhibitor in human clinical
trials.
AB - The discovery and cloning of the cyclin-dependent kinases (cdks), main regulators
of cell cycle progression, allowed several investigators to design novel
modulators of cdk activity. Flavopiridol (HMR 1275, L86-8275), a flavonoid
derived from an indigenous plant from India, demonstrated potent and specific in
vitro inhibition of all cdks tested (cdks 1, 2, 4 and 7) with clear block in cell
cycle progression at the G1/S and G2/M boundaries. Moreover, preclinical studies
demonstrated the capacity of flavopiridol to induce programmed cell death,
promote differentiation, inhibit angiogenic processes and modulate
transcriptional events. The relationship between the latter effects and cdk
inhibition is still unclear. Initial testing in early clinical human trials with
infusional flavopiridol showed activity in some patients with non-Hodgkin's
lymphoma, renal, prostate, colon and gastric carcinomas. Main side effects were
secretory diarrhea and a pro-inflammatory syndrome associated with hypotension.
Biologically active plasma concentrations of flavopiridol (approximately 300-500
nM) are easily achievable in patients receiving infusional flavopiridol. Phase 2
trials with infusional flavopiridol in several tumor types, other schedules and
combination with standard chemotherapies are being assessed. In conclusion,
flavopiridol is the first cdk inhibitor to be tested in clinical trials. Although
important questions remain to be answered, this positive experience will
stimulate the development of novel cdk modulators for cancer therapy.
PMID- 10665482
TI - Age-related white matter changes and cognitive impairment.
PMID- 10665483
TI - Congenital muscular dystrophy: an expanding clinical syndrome.
PMID- 10665480
TI - Antiestrogens--tamoxifen, SERMs and beyond.
AB - Estrogens play a central role in reproductive physiology. The cellular effects of
estrogens are mediated by binding to nuclear receptors (ER) which activate
transcription of genes involved in cellular growth control. At least two such
receptors, designated ERalpha and ERbeta, mediate these effects in conjunction
with a number of coactivators. These receptors can directly interact with other
members of the steroid receptor superfamily. A complex cross-talk exists between
the estrogen-signaling pathways and the downstream signaling events initiated by
growth factors, such as epidermal growth factor and insulin-like growth factors.
Estrogens are also a causative factor in the pathogenesis of a variety of
neoplastic and non-neoplastic diseases, including breast cancer, endometrial
cancer, endometriosis, and uterine fibroids, among others. Antiestrogens, such as
tamoxifen, are widely used for the treatment of breast cancer. Tamoxifen produces
objective tumor shrinkage in advanced breast cancer, reduces the risk of relapse
in women treated for invasive breast cancer, and prevents breast cancer in high
risk women. Although, initially developed as an antiestrogen, tamoxifen can also
prevent postmenopausal osteoporosis as well as reduce cholesterol, due to its
estrogen-agonist effects. Its estrogen-agonist activity, however, can lead to
significant side-effects such as endometrial cancer and thromboembolic phenomena.
This has led to the concept of "ideal" selective estrogen receptor modulators
(SERMs), drugs that would have the desired, tissue selective, estrogen-agonist or
-antagonist effects. Raloxifene is a SERM which has the desirable mixed
agonist/antagonist effects of tamoxifen but does not cause uterine stimulation.
"Pure" antiestrogens may provide very potent estrogen-antagonist drugs, but are
likely to be devoid of beneficial effects on bone and lipids. Future drug
development efforts should focus on developing superior SERMs that have a greater
efficacy against ER-positive tumors and do not cause hot flashes or
thromboembolism, and explore combination strategies to simultaneously target
hormone-dependent as well as hormone-independent breast cancer.
PMID- 10665484
TI - Cerebral white matter lesions and cognitive function: the Rotterdam Scan Study.
AB - Cerebral white matter lesions (WMLs) have been associated with cognitive
dysfunction. Whether periventricular or subcortical WMLs relate differently to
cognitive function is still uncertain. In addition, it is unclear whether WMLs
are related to specific cognitive domains such as memory or psychomotor speed. We
examined the relationship between periventricular and subcortical WMLs and
cognitive functioning in 1,077 elderly subjects randomly sampled from the general
population. Quantification of WMLs was assessed by means of an extensive rating
scale on 1.5-T magnetic resonance imaging scans. Cognitive function was assessed
by using multiple neuropsychological tests from which we constructed compound
scores for psychomotor speed, memory performance, and global cognitive function.
When analyzed separately, both periventricular and subcortical WMLs were related
to all neuropsychological measures. When periventricular WMLs were analyzed
conditional on subcortical WMLs and vice versa, the relationship between
periventricular WMLs and global cognitive function remained unaltered whereas the
relationship with subcortical WMLs disappeared. Subjects with most severe
periventricular WMLs performed nearly 1 SD below average on tasks involving
psychomotor speed, and more than 0.5 SD below average for global cognitive
function. Tasks that involve speed of cognitive processes appear to be more
affected by WMLs than memory tasks.
PMID- 10665485
TI - Congenital muscular dystrophy with rigid spine syndrome: a clinical,
pathological, radiological, and genetic study.
AB - Rigid spine syndrome is a term first proposed by Dubowitz to describe a subset of
patients affected by myopathy with early spinal contractures as a prominent
feature. While spinal rigidity is a nonspecific feature, found in Emery-Dreifuss
muscular dystrophy and in some congenital myopathies, it is also a prominent
feature in a group of patients with merosin-positive congenital muscular
dystrophy, where it is generally associated with stable or only slowly
progressive weakness and early respiratory insufficiency. Recently, the first
locus for congenital muscular dystrophy in association with rigid spine syndrome
was mapped to chromosome 1p35-p36 in consanguineous Moroccan, Turkish, and
Iranian families. We present here a detailed phenotypic description of the
familial syndrome linked to this locus, describing 4 siblings (3 boys and 1 girl)
of Northern European-American heritage who are the offspring of a
nonconsanguineous marriage. All 4 siblings were affected by hypotonia and
prominent neck weakness in infancy, early spinal rigidity, and early scoliosis.
After initial improvement, muscle strength stabilizes or slowly declines, and
skeletal deformities and respiratory insufficiency supervene. Muscle biopsy in an
affected child at age 9 months revealed minimal, nonspecific myopathic changes,
leading to a diagnosis of "minimal change myopathy." Muscle biopsy in his
sibling, at the age of 14 years, revealed chronic and severe myopathic
(dystrophic) changes, with normal staining for laminin-2 and for proteins of the
dystrophin-glycoprotein complex. A possible explanation for these biopsy findings
is that magnetic resonance imaging of the thighs reveals stereotyped selective
muscle involvement, with the selectivity more pronounced early in the disease
course followed by widespread muscular signal abnormalities in the late stages of
the disease. In this family, linkage to the chromosome 1p rigid spine syndrome
locus (RSMD1) is supported by maximum LOD scores for several markers of 1.81 at
theta = 0, representing the maximum statistical power possible for this family.
In combination with the previous report, this syndrome is linked to the RSMD1
locus with a summated maximum LOD score of 6.29, and analysis of recombination
events in our family narrows the previously reported RSMD1 locus to 3
centiMorgans.
PMID- 10665486
TI - The spectrum of mutations causing end-plate acetylcholinesterase deficiency.
AB - The end-plate species of acetylcholinesterase (AChE) is an asymmetric enzyme
consisting of a collagenic tail subunit composed of three collagenic strands
(ColQ), each attached to a tetramer of the T isoform of the catalytic subunit
(AChE(T)) via a proline-rich attachment domain. The principal function of the
tail subunit is to anchor asymmetric AChE in the synaptic basal lamina. Human end
plate AChE deficiency was recently shown to be caused by mutations in COLQ. We
here report nine novel COLQ mutations in 7 patients with end-plate AChE
deficiency. We examine the effects of the mutations on the assembly of asymmetric
AChE by coexpressing each genetically engineered COLQ mutant with ACHE(T) in COS
cells. We classify the newly recognized and previously reported COLQ mutations
into four classes according to their position in ColQ and their effect on AChE
expression. We find that missense mutations in the proline-rich attachment domain
abrogate attachment of catalytic subunits, that truncation mutations in the ColQ
collagen domain prevent the assembly of asymmetric AChE, that hydrophobic
missense residues in the C-terminal domain prevent triple helical assembly of the
ColQ collagen domain, and that other mutations in the C-terminal region produce
asymmetric species of AChE that are likely insertion incompetent.
PMID- 10665487
TI - Impaired reading in patients with right hemianopia.
AB - A left occipital stroke may result in alexia for two reasons, which may coexist
depending on the distribution of the lesion. A lesion of the left lateroventral
prestriate cortex or its afferents impairs word recognition ("pure" alexia). If
the left primary visual cortex or its afferents are destroyed, resulting in a
complete right homonymous hemianopia, rightward saccades during text reading are
disrupted ("hemianopic" alexia). By using functional imaging, we showed two
separate but interdependent systems involved in reading. The first, subserving
word recognition, involved the representation of foveal vision in the left and
right primary visual cortex and the ventral prestriate cortex. The second system,
responsible for the planning and execution of reading saccades, consisted of the
representation of right parafoveal vision in the left visual cortex, the
bilateral posterior parietal cortex (left > right), and the frontal eye fields
(right > left). Disruption of this distributed neural system was demonstrated in
patients with severe right homonymous hemianopia, commensurate with their
inability to perform normal reading eye movements. Text reading, before processes
involved in comprehension, requires the integration of perceptual and motor
processes. We have demonstrated these distributed neural systems in normal
readers and have shown how a right homonymous hemianopia disrupts the motor
preparation of reading saccades during text reading.
PMID- 10665488
TI - Oxidative phosphorylation defect in the brains of carriers of the tRNAleu(UUR)
A3243G mutation in a MELAS pedigree.
AB - MELAS is a mitochondrial encephalomyopathy characterized clinically by recurrent
stroke-like episodes, seizures, sensorineural deafness, dementia, hypertrophic
cardiomyopathy, and short stature. The majority of patients are heteroplasmic for
a mutation (A3243G) in the tRNAleu(UUR) gene in mitochondrial DNA (mtDNA). In
cells cultured in vitro, the mutation produces a severe mitochondrial translation
defect only when the proportion of mutant mtDNAs exceeds 95% of total mtDNAs.
However, most patients are symptomatic well below this threshold, a paradox that
remains unexplained. We studied the relationship between the level of
heteroplasmy for the mutant mtDNA and the clinical and biochemical abnormalities
in a large pedigree that included 8 individuals carrying the A3243G mutation, 4
of whom were asymptomatic. Unexpectedly, we found that brain lactate, a sensitive
indicator of oxidative phosphorylation dysfunction, was linearly related to the
proportion of mutant mtDNAs in all individuals carrying the mutation, whether
they were symptomatic or not. There was no evidence for threshold expression of
the metabolic defect. These results suggest that marked tissue-specific
differences may exist in the pathogenic expression of the A3243G mutation and
explain why a neurological phenotype can be observed at relatively low levels of
heteroplasmy.
PMID- 10665489
TI - Synergistic neurotoxicity by human immunodeficiency virus proteins Tat and gp120:
protection by memantine.
AB - Human immunodeficiency virus type 1 (HIV-1) proteins Tat and gp120 have been
implicated in the pathogenesis of dementia associated with HIV infection.
Recently, we showed the presence of Tat protein in brains of patients with HIV-1
encephalitis as well as macaques with encephalitis caused by a chimeric strain of
HIV and simian immunodeficiency virus, and that even transient exposure of cells
to Tat leads to release of cytopathic cytokines. Now, we report the first
demonstration of gp120 protein in brain of patients with HIV encephalitis. We
tested the hypothesis that Tat and gp120 would act synergistically to potentiate
each protein's neurotoxic effects and determined the extent to which
pharmacological antagonists against processes implicated in HIV-1
neuropathogenesis could block HIV-1 protein-induced neurotoxicity. Subtoxic
concentrations of Tat and gp120, when incubated together, caused neuronal cell
death and prolonged increases in levels of intracellular calcium. A transient
exposure of neurons to Tat and gp120 for seconds initiated neuronal cell death,
but maximal levels of neuronal cell death were observed with exposures lasting 30
minutes. The neurotoxicity caused by Tat and gp120 applied in combination was
blocked completely by memantine, partially by amiloride, and not at all by
dipyridamole or vigabatrin.
PMID- 10665490
TI - Prognostic value of proton magnetic resonance spectroscopic imaging for surgical
outcome in patients with intractable temporal lobe epilepsy and bilateral
hippocampal atrophy.
AB - The objective of this study was to assess which features of temporal lobe proton
magnetic resonance spectroscopic imaging (1H-MRSI) are associated with
satisfactory surgical outcome in patients with intractable temporal lobe epilepsy
and bilateral hippocampal atrophy. We studied 21 patients with intractable
temporal lobe epilepsy and bilateral hippocampal atrophy defined by magnetic
resonance imaging volumetric measurements who underwent surgical treatment. 1H
MRSI was used to determine the relative resonance intensity ratio of the neuronal
marker N-acetylaspartate to creatine + phosphocreatine (NAA/Cr) for mid and
posterior temporal lobe regions of the left and right hemisphere, as well as an
asymmetry index. Values lower than 2 SDs below the normal mean were considered
abnormal. We used Engel's classification to assess surgical outcome with respect
to seizure control. Eleven patients (52%) were in class I-II and 10 (48%) were in
class III-IV. All 21 were operated on the side of maximal electroencephalographic
(EEG) lateralization. Concordant lateralization of decreases in NAA/Cr to the
side of surgery and normal NAA/Cr values in the contralateral posterior-temporal
region were significantly associated with good surgical outcome: 11 (69%) of 16
patients with 1H-MRSI abnormalities concordant with EEG lateralization and none
of the 5 patients with nonconcordant 1H-MRSI had a good outcome (class I-II); 10
(77%) of 13 patients with normal NAA/Cr contralateral to the EEG lateralization
versus 1 (12.5%) of 8 of those with NAA/Cr reduction contralateral to EEG
lateralization were in class I-II. Regression correlation analysis showed
significant linear correlation between the midtemporal NAA/Cr relative asymmetry
ratio and surgical outcome; the greater the asymmetry, the better the outcome. We
conclude that discriminant 1H-MRSI features associated with favorable surgical
outcome in patients with temporal lobe epilepsy and bilateral hippocampal atrophy
were (1) concordant 1H-MRSI lateralization, (2) a greater side-to-side asymmetry
of NAA/Cr, and (3) an absence of contralateral posterior NAA/Cr reduction.
PMID- 10665491
TI - Expression of alpha-synuclein, parkin, and ubiquitin carboxy-terminal hydrolase
L1 mRNA in human brain: genes associated with familial Parkinson's disease.
AB - Mutations in the alpha-synuclein, parkin, and ubiquitin carboxy-terminal
hydrolase L1 (UCH-L1) genes have been linked to some cases of familial
Parkinson's disease. To provide insight into how these genes may relate to each
other and contribute to the pathology of Parkinson's disease, their expression
was examined in normal human brain. Tissue sections from multiple regions of 11
normal human brains were hybridized with radiolabeled and digoxygenin-labeled
cRNA probes for alpha-synuclein, parkin, and UCH-L1 mRNA. Expression of each of
these three genes was predominantly neuronal. Alpha-synuclein and parkin mRNAs
were expressed in a restricted number of brain regions, whereas UCH-L1 mRNA was
more uniformly expressed throughout brain. The melanin-containing dopamine
neurons of the substantia nigra had particularly robust expression. The
expression patterns of alpha-synuclein and parkin mRNAs were similar, suggesting
that these two proteins may be involved in common pathways contributing to the
pathophysiology of Parkinson's disease.
PMID- 10665492
TI - Molecular analysis of the CDR3 encoding region of the immunoglobulin heavy chain
locus in cerebrospinal fluid cells as a diagnostic tool in lymphomatous
meningitis.
AB - The diagnosis of leptomeningeal B-cell lymphoma is based on the identification of
malignant B cells in the cerebrospinal fluid (CSF). Frequently, cytology does not
allow clear distinction between neoplastic lymphoid cells and reactively
transformed mononuclear cells. Individual B-cell clones can be identified on the
basis of DNA sequences that encode the highly diverse complementarity-determining
region (CDR3) of the immunoglobulin heavy chain locus (IgH). We studied CSF
samples from 5 patients with B-cell malignancies and cytological evidence of
leptomeningeal involvement, using polymerase chain reaction (PCR)-based high
resolution capillary electrophoresis and automated fluorescence analysis to
detect PCR fragments. As controls, we assessed CSF specimens from 7 patients with
inflammatory neurological diseases and three samples without pathological
findings. In all patients with B-cell malignancies, a single PCR product was
generated, indicating that CDR3-specific fragments were derived from monoclonal
cell populations. CSF samples from patients with inflammatory diseases yielded
multiple CDR3 amplicons, suggesting the presence of a polyclonal B-cell
activation. No PCR product could be amplified in normal CSF samples. Automated
fluorescence detection of CDR3 fragments is a highly sensitive and rapid method
to distinguish neoplastic monoclonal and reactive polyclonal B-cell populations
in the CSF.
PMID- 10665493
TI - Joint position sense is impaired by Parkinson's disease.
AB - The abilities of Parkinson's disease (PD) patients, taking routine medication,
and of control subjects, to discriminate bilateral differences in the static
angular positions of the two elbow joints were studied during passive (subject
relaxed) and active (subject contracting to hold position) conditions. On each
trial, one of the subject's elbows served as the reference joint (angle 60
degrees) and the other as the test joint (angular range, 54 degrees to 69
degrees, at 3 degree intervals). Subjects, with eyes closed, were required to
discriminate the relative angles of the two elbows. In Experiments 1 (passive
condition) and 2 (active condition), parkinsonians (n = 12) gave significantly
fewer correct responses, pooled across sides, than did controls (n = 12), both in
total scores across all angles and at individual test angles of 57 degrees and 63
degrees. In Experiment 3 (passive condition), derivation of conventional
psychophysical variables indicated that both the difference limen (DL; threshold)
and Weber ratio (WR; discriminatory sensitivity, independent of absolute stimulus
values; same as DL/PSE) values of patients (n = 6) were significantly larger than
those of controls (n = 6), in the absence of a significant difference between
groups in the point of subjective equality (PSE). Our results provide clear
evidence of a quantitative impairment of joint position sense in PD patients.
PMID- 10665494
TI - Profile of endothelial and leukocyte activation in Fabry patients.
AB - Fabry disease is an X-linked recessive disorder resulting in the deposition of
globotriaosylceramide in numerous cell types including vascular endothelial
cells. Because this disease is associated with vascular injury and a high
recurrence rate of thrombotic events, measurements of factors regulating
endothelium and leukocyte interaction may provide insight into the mechanisms
leading to a prothrombotic state. Twenty-five patients with Fabry disease and 25
control subjects participated in the study. Plasma from all 25 Fabry patients and
15 of the 25 controls were studied for multiple endothelial factors. Leukocyte
integrins were measured by flow cytometry in 21 Fabry patients and 10 controls.
The concentrations of soluble intercellular adhesion molecule-1, vascular cell
adhesion molecule-1, P-selectin, and plasminogen activator inhibitor were
significantly higher and thrombomodulin was significantly lower in Fabry
patients. Expression of the integrin CD11b on monocytes was also significantly
higher in the Fabry patients. This study reveals measurable evidence for
endothelium and leukocyte activation that is consistent with a prothrombotic
state in Fabry patients compared with controls. Further investigations of these
findings may help to understand the mechanism of stroke in Fabry disease and
provide indicators (or markers) of efficacy of future therapeutic intervention.
PMID- 10665495
TI - Heterogeneity of T-lymphocyte function in primary progressive multiple sclerosis:
relation to magnetic resonance imaging lesion volume.
AB - We found that in vitro migration and interferon-gamma production by lymphocytes
derived from primary progressive multiple sclerosis patients preselected on the
basis of a high T2-weighted lesion volume (>10 cm3) on magnetic resonance
imaging, were increased compared with that in primary progressive multiple
sclerosis patients with a low T2-weighted lesion volume (<3 cm3) and controls.
Whether the heterogeneity of immune function within the primary progressive
population will correlate with response to therapy remains to be established.
PMID- 10665496
TI - No acute antimigraine efficacy of CP-122,288, a highly potent inhibitor of
neurogenic inflammation: results of two randomized, double-blind, placebo
controlled clinical trials.
AB - CP-122,288 is a highly potent inhibitor of neurogenic plasma extravasation in
animal models at doses without vasoconstrictor effect. We evaluated the acute
antimigraine efficacy of intravenous and oral CP-122,288 in two double-blind
studies. In a crossover design, patients randomly received 31.25 microg of CP
122,288 intravenously, placebo, or both. In the oral study, patients received
placebo or one of four doses of CP-122,288 between 3.125 and 312.5 microg, using
a novel "up and down" design for randomization. Both studies were stopped
prematurely when target efficacy could not be achieved. Responder rates were 29%
for CP-122,288 versus 30% for placebo (difference, -1%; 95% CI, -24-22%;
intravenous study) and an overall rate of 25% for CP-122,288 versus 0% for
placebo (difference, 25%; 95% CI; 10-40%; oral study). CP-122,288 was not
clinically effective at doses and plasma concentrations in excess of those
required to inhibit neurogenic plasma extravasation in animals. Neurogenic plasma
extravasation is unlikely to play a crucial role in the pathophysiology of
migraine headache.
PMID- 10665497
TI - Significant association between the tau gene A0/A0 genotype and Parkinson's
disease.
AB - A significant association between the tau gene A0/A0 genotype and progressive
supranuclear palsy has been reported recently. To determine if the presence of a
tau polymorphism could constitute a risk factor for the development of sporadic
and familial Parkinson's disease, a dinucleotide repeat marker at intron 11 was
genotyped in 152 patients with PD, 52 patients with Alzheimer's disease, and 150
healthy controls. We detected a significant difference in A0 allelic frequency in
the Parkinson's disease group (79.27%) compared with the control group (71%) and
the Alzheimer's disease group (73.07%). Individuals homozygous for the A0 allele
were also detected significantly more frequently in the Parkinson's disease group
(63.8%) compared with the control group (52.66%) and the Alzheimer's disease
group (48.07%). These results suggest a possible involvement of the tau gene in
the pathogenesis of some cases of Parkinson's disease.
PMID- 10665498
TI - Major depression is a risk factor for seizures in older adults.
AB - We tested the hypothesis that major depression meeting DSM-III-R criteria or
medical therapies for depression increase the risk for unprovoked seizures. Major
depression was associated with a sixfold increased risk for unprovoked seizures
(95% CI, 1.56-22). The risk remained increased even when controlling for age,
sex, length of medical follow-up, and medical therapies for depression. In the
absence of known prior neurological insult, major depression is associated with
an increased risk for unprovoked seizures.
PMID- 10665499
TI - Novel Leu723Pro amyloid precursor protein mutation increases amyloid beta42(43)
peptide levels and induces apoptosis.
AB - A novel missense mutation, Leu723Pro, in the amyloid precursor protein (APP) gene
was discovered in an early-onset Alzheimer's disease family. Expression of L723P
mutant APP complementary DNA in CHO cells resulted in a 1.4- to 1.9-fold
increased production of the 42(43)-amino acid length amyloid beta peptide
compared with the wild-type sequence and was capable of causing apoptosis. The
mutation is predicted to alter the luminal transmembrane length and helical
arrangement of the APP molecule and thus affect the gamma-secretase cleavage
site.
PMID- 10665500
TI - Prenatal testing for late infantile neuronal ceroid lipofuscinosis.
AB - Classic late infantile neuronal ceroid lipofuscinosis (LINCL) is a
neurodegenerative disease in which autofluorescent "curvilinear" storage bodies
accumulate in tissues from affected patients. Recently, the LINCL gene (CLN2) has
been found to code for a pepstatin-insensitive lysosomal protease whose activity
is deficient in LINCL specimens. We report the first 2 cases of successful
prenatal testing for LINCL by using DNA and enzyme-based methods on amniocytes,
and describe a new private mutation in one of the families analyzed. These
approaches allow definitive prenatal diagnosis and represent a significant
improvement over previous pathological methods.
PMID- 10665501
TI - Creutzfeldt-Jakob disease profile in patients homozygous for the PRNP E200K
mutation.
AB - We identified 70 Creutzfeldt-Jakob disease patients with the previously described
E200K mutation in the prion protein gene. The purpose of this study was to define
the clinical features of E200K homozygous patients (n = 5), compared with
heterozygotes. We found a statistically significant younger age at disease onset
for the homozygous patients, although the average age at onset in this group was
still in midlife. Disease features were not statistically different in the two
groups. Possible explanations are discussed.
PMID- 10665502
TI - Vitamin E deficiency due to chylomicron retention disease in Marinesco-Sjogren
syndrome.
AB - We report on 2 brothers (aged 19 and 12 years) with Marinesco-Sjogren syndrome
who also had very low serum vitamin E concentrations with an absence of
postprandial chylomicrons. The molecular study ruled out ataxia with isolated
vitamin E deficiency, abetalipoproteinemia, and hypobetalipoproteinemia. The
electron microscopy of the intestinal mucosa was consistent with a chylomicron
retention disease. We speculate that both chylomicron retention disease and
Marinesco-Sjogren syndrome are related to defects in a gene crucial for the
assembly or secretion of the chylomicron particles, leading to very low serum
levels of vitamin E.
PMID- 10665503
TI - Genetic and neuroradiological heterogeneity of double cortex syndrome.
AB - Mutations in the X-linked doublecortin gene appear in many sporadic cases of
double cortex (DC; also known as subcortical band heterotopia), a neuronal
migration disorder causing epilepsy and mental retardation. The purpose of this
study was to examine why a significant percentage of sporadic DC patients had
been found not to harbor doublecortin mutations and to determine whether clinical
features or magnetic resonance imaging scan appearance could distinguish between
patients with and without doublecortin mutations. Magnetic resonance imaging scan
analysis differentiated patients into the following four groups: anterior
biased/global DC with doublecortin mutation (16 of 30; 53%), anterior
biased/global DC without mutation (8 of 30; 27%), posterior biased DC without
mutation (3 of 30; 10%), and limited/unilateral DC without mutation (3 of 30;
10%). The presence of these atypical phenotypes suggests that other genetic loci
or mosaicism at the doublecortin locus may be responsible for this diversity of
DC cases.
PMID- 10665504
TI - Increased numbers of CCR5+ interferon-gamma- and tumor necrosis factor-alpha
secreting T lymphocytes in multiple sclerosis patients.
AB - To determine the frequency of in vivo activated T(H)1 lymphocytes, T-cell subsets
of 9 multiple sclerosis patients with active disease and 17 healthy controls were
analyzed by immunostaining for CCR5, CD26, and their expression of interleukin-2,
interferon-gamma, and tumor necrosis factor-alpha. The numbers of CCR5+
interferon-gamma- and tumor necrosis factor-alpha-producing T cells were
significantly increased in the peripheral blood of multiple sclerosis patients.
CCR5 expression may be a useful marker to identify effector cells in multiple
sclerosis and could be used as a tool for monitoring disease activity.
PMID- 10665505
TI - No cytomegalovirus DNA in sera from patients with anti-MAG/SGPG antibody
associated neuropathy.
PMID- 10665506
TI - The Pocket Monsters episode.
PMID- 10665507
TI - Seasonal fluctuations of gadolinium-enhancing magnetic resonance imaging lesions
in multiple sclerosis.
PMID- 10665508
TI - Intracellular adhesion molecule-1 polymorphisms and genetic susceptibility to
multiple sclerosis: additional data and meta-analysis.
PMID- 10665509
TI - Subtle brain abnormalities in children with sickle cell disease: relationship to
blood hematocrit.
PMID- 10665510
TI - Effect of vowel environment on consonant duration: an extension of normative data
to adult contextual speech.
AB - In this study, we investigated the effect of vowel environment on consonant
duration in contextual speech produced by adults. Previous studies, such as
Schwartz's published in 1969 and DiSimoni's in 1974, of vowel influence on
consonant duration have supported the notion of anticipatory scanning in which
final vowel targets influence the duration of preceding fricative consonants.
These studies were based on repetitions of nonsense syllables by children and
adults, but no research has been reported that extends these data to contextual
speech or examines speaker gender differences. Forty adult normal speakers (20
women and 20 men) recorded palatal and alveolar fricatives produced in four vowel
environments in words embedded in contextual sentences. Results indicated
significant effects of vowel context on consonant duration in contextual speech
and revealed anticipatory scanning effects that are similar to those seen with
nonsense syllables in previous studies. These normative data can form the basis
for comparison of the effects of temporal alterations produced by speaking
conditions such as simultaneous communication.
PMID- 10665511
TI - Academic outcomes in children with histories of speech sound disorders.
AB - Tests of phonology, semantics, and syntax were administered to 52 preschool
children (19 girls and 33 boys, age 4-6 years) with moderate to severe speech
sound disorders. The children's performance on these tests was used to predict
language, reading, and spelling abilities at school age (age 8-11 years).
Language impairment at school age was related to poor performance on preschool
tests of syntax and nonsense word repetition, while reading impairment was
predicted by poor performance in all preschool test domains (phonology,
semantics, and syntax). In contrast, spelling impairment was predicted by
deficits in preschool tests of phonological processing as measured by the Word
Discrimination subtest of the Test of Language Development - Primary 2. Family
history for speech and language disorders did not predict language, reading, or
spelling impairment at school age. However, family history for reading disorders
was a good predictor of school-age spelling difficulties.
PMID- 10665512
TI - Cultural analysis of communication behaviors among juveniles in a correctional
facility.
AB - This study addressed communication behaviors of female juvenile delinquents in a
correctional facility. Qualitative methodology was used to study 78 participants
ranging in age from 13.1 to 18.9 (years; months), over a five-month period. Data
collection consisted of observations, participant observation, interviews, and a
review of documents. Additionally, participants were tested on the Clinical
Evaluation of Language Fundamentals-3. Listening and following rules, utterance
types, topics of conversion, politeness, and conversational management emerged as
themes. Findings indicated that as many as 22% of participants were potential
candidates for language services. Implications for speech-language pathologists
(SLPs) providing communication services will be provided.
PMID- 10665513
TI - Effects of speech therapy and pharmacologic and surgical treatments on voice and
speech in Parkinson's disease: a review of the literature.
AB - The purpose of this review was to examine the different treatment approaches for
persons with Parkinson's Disease (PD) and to examine the effects of these
treatments on speech. Treatment methods reviewed include speech therapy,
pharmacological, and surgical. Research from the 1950s through the 1970s had not
demonstrated significant improvements following speech therapy. Recent research
has shown that speech therapy (when persons with PD are optimally medicated) has
proven to be the most efficacious therapeutic method for improving voice and
speech function. Pharmacological methods of treatment in isolation do not appear
to significantly improve voice and speech function in PD across research studies.
Surgical treatment methods including pallidotomy and deep brain stimulation may
be significant treatment options which improve voice and speech function in some
persons with PD. Possible explanations for the differential responses to
treatment are discussed. Future studies should investigate the effects of
combined treatment approaches. Perhaps the combination of pharmacological,
surgical and speech treatment will prove superior to treatments combining
pharmacological and surgical or pharmacological and speech therapy in improving
the communication abilities of persons with PD.
PMID- 10665514
TI - Preclinical overview of brinzolamide.
AB - The development of topically active carbonic anhydrase inhibitors (CAIs) is a
significant recent achievement in glaucoma medical treatment. Brinzolamide, the
newest topical CAI, exhibits selectivity, high affinity, and potent inhibitory
activity for the carbonic anhydrase type II isozyme (CA-II), which is involved in
aqueous humor secretion. These characteristics, along with good ocular
bioavailability, make brinzolamide maximally effective in lowering intraocular
pressure (IOP) by locally inhibiting CA-II in the ciliary processes and
suppressing aqueous humor secretion. Notable among its attributes as a safe and
efficacious glaucoma drug is brinzolamide's superior ocular comfort profile
because of its optimized suspension formulation at physiologic pH. The degree of
tolerability in the eye is considered an important determinant of a patient's
willingness to comply with the dosing regimen for a long-term glaucoma
medication. Results from the preclinical pharmacologic evaluation of brinzolamide
indicated that it acts specifically to inhibit CA without significant other
pharmacologic actions that could introduce undesired side effects. Moreover, the
typical side effects associated with systemically administered CAIs are expected
to occur at a lower incidence or not occur at all with brinzolamide, as its
therapeutic dose and low systemic absorption do not produce a problematic level
of systemic CA inhibition. Brinzolamide's long tissue half-life in the eye,
particularly in the iris-ciliary body, favors a prolonged duration of IOP
lowering. This was substantiated in clinical trials, which showed that twice
daily brinzolamide provides as significant an IOP reduction as three-times-daily
brinzolamide or dorzolamide in a relatively high percentage of patients.
Brinzolamide has been shown by the laser Doppler flowmetry technique to improve
blood flow to the optic nerve head in pigmented rabbits after topical
administration, without producing an increase of blood pCO2, indicating a
potential for a local vasodilatory effect involving the optic nerve head
circulation. The mean concentration of brinzolamide found in the retina of
pigmented rabbits (0.338 microg equivalents/g) after a single dose of 14C
brinzolamide is sufficient to inhibit CA-II. These data suggest that topical
brinzolamide could improve the blood flow in the optic nerve head in humans
should it inhibit carbonic anhydrase in that vascular bed. Brinzolamide is a new
topically active CAI that is safe and efficacious for reducing intraocular
pressure. It offers the convenience of topical dose administration and greater
freedom from side effects related to the inhibition of CA seen with the systemic
administration of CAIs. Its formulation has been optimized to provide greater
comfort upon instillation, and this can result in a higher compliance rate by the
patient. Results of studies in animals show that brinzolamide has promise for
increasing blood flow to the optic nerve head; however, this requires further
assessment in the clinic. Brinzolamide represents a significant technical
achievement and an important addition to the medical treatment of glaucoma as
both a primary and an adjunctive drug.
PMID- 10665515
TI - Increased optic nerve head blood flow after 1 week of twice daily topical
brinzolamide treatment in Dutch-belted rabbits.
AB - OBJECTIVES: Using a three-way crossover study design, we compared the effects of
brinzolamide 2%, dorzolamide 2%, and placebo (vehicle) on microvascular optic
nerve head (ONH) blood flow, intraocular pressure (IOP), blood pressure, heart
rate, and acid-base balance in nine acepromazine-tranquilized Dutch-belted
rabbits. METHODS: Baseline measurements were taken before treatment and after
drug-free washout periods of 7-14 days. Microvascular ONH blood flow was measured
with a fundus camera-based laser Doppler flowmeter (LDF). Intraocular pressure
was measured with a Tono-Pen XL. One drop of brinzolamide, dorzolamide, or
vehicle was administered twice daily (9 A.M. and 5 P.M.) in right eyes only for 7
days. Experimental measurements were made 90 minutes after the 9 A.M. topical
dose was administered on day 8. RESULTS: ONH blood flow was significantly
increased (P< or =0.05) in carbonic anhydrase inhibitor (CAI)-treated rabbits, as
compared with vehicle-treated controls. The percent increase from baseline was
11.2+/-1.8% in brinzolamide-treated animals and 8.4+/-4.3% in dorzolamide-treated
animals. Compared with controls, IOP in the brinzolamide- and dorzolamide-treated
groups was significantly decreased (P< or =0.05). The changes in ONH blood flow
and IOP were not significantly different between the CAI treatment groups. Small
but significant changes in systemic blood gas tensions and pH were present in
both CAI treatment groups, as compared with the vehicle group. Systemic blood
pressure and heart rate were not significantly changed. CONCLUSIONS: Topical
ocular CAI treatment for 1 week with either brinzolamide or dorzolamide
significantly reduced IOP and significantly increased ONH blood flow in
tranquilized Dutch-belted rabbits, while eliciting minimal systemic acid-base
balance disturbances.
PMID- 10665516
TI - Ocular comfort of brinzolamide 1.0% ophthalmic suspension compared with
dorzolamide 2.0% ophthalmic solution: results from two multicenter comfort
studies. Brinzolamide Comfort Study Group.
AB - Two independent, prospective, multicenter, double-masked, parallel group trials
were conducted to compare the ocular comfort of brinzolamide 1.0% administered
three times daily (t.i.d.) with t.i.d.-dosed dorzolamide 2.0% in patients with
primary open-angle glaucoma or ocular hypertension. Patients were randomized to
one of two treatment groups, receiving either brinzolamide 1.0% t.i.d. or
dorzolamide 2.0% t.i.d. for 1 week. On the last day of dosing, patients received
one drop of masked medication in both eyes, and ocular discomfort (burning or
stinging) was evaluated by means of a 4-unit ocular discomfort scale. The
incidence and extent of ocular discomfort across both treatment groups were
analyzed. The results from both studies were confirmatory and demonstrated that
the ocular discomfort score for brinzolamide 1.0% was 1.3 units lower than the
score for dorzolamide 2.0%, which was both statistically significant and
clinically relevant. In addition, a statistically significantly greater
percentage of patients reported no ocular discomfort with brinzolamide 1.0%
compared with dorzolamide. A greater percentage of patients receiving dorzolamide
2.0% also reported mild, moderate, severe, and very severe ocular discomfort
compared with those treated with brinzolamide 1.0%. The most frequent ocular
adverse event reported in the brinzolamide group was transient blurred vision,
which ranged from 20% to 25%. Overall, adverse events associated with
brinzolamide 1.0% and dorzolamide 2.0% were nonserious, were usually mild, and
resolved without treatment. The findings of each study independently demonstrated
that brinzolamide 1.0% was significantly more comfortable than dorzolamide 2.0%
when instilled in the eye.
PMID- 10665517
TI - Dose-response evaluation of the ocular hypotensive effect of brinzolamide
ophthalmic suspension (Azopt). Brinzolamide Dose-Response Study Group.
AB - Brinzolamide is a novel carbonic anhydrase inhibitor that elicits an ocular
hypotensive effect when instilled topically. A multicenter, double-masked,
placebo-controlled, parallel trial was conducted to evaluate the optimal
intraocular pressure (IOP)-lowering concentration and ocular tolerability of
topically administered brinzolamide (0.3%, 1%, 2%, and 3%) in patients with
primary, open-angle glaucoma or ocular hypertension. After a washout phase,
patients were administered brinzolamide or placebo twice daily for 2 weeks. The
IOP was measured on days 8 and 15 at 8:00 A.M., and then 2, 4, 8, and 12 hours
after dosing, and these measurements were compared with IOP values obtained at
the corresponding times during an off-therapy diurnal baseline. All
concentrations of brinzolamide produced significantly greater (P<0.005) mean
percent IOP reductions and mean IOP reductions compared with placebo. Mean
percent IOP changes (mean IOP changes) from baseline for brinzolamide 0.3%, 1%,
2%, and 3% were -11.3% (-3.0 mm Hg), -16.1% (-4.3 mm Hg), -16.1% (-4.4 mm Hg),
and -15.4% (-4.2 mm Hg), respectively, when pooled over visit and visit time.
Comparisons between concentrations demonstrated that the mean percent IOP
reduction for brinzolamide 1.0% was significantly greater than that for the 0.3%
concentration (P<0.03), with no difference in efficacy between the 1%, 2%, and 3%
concentrations. The incidence of adverse events was dose-dependent, and those
related to therapy were usually mild and resolved without treatment. Blurred
vision, ocular discomfort, and abnormal taste were the most frequently reported
adverse events. Based on these findings, the optimal IOP-lowering concentration
of brinzolamide was 1%. When administered twice daily, brinzolamide 1% was well
tolerated by patients with primary open-angle glaucoma or ocular hypertension.
PMID- 10665518
TI - The efficacy and safety of brinzolamide 1% ophthalmic suspension (Azopt) as a
primary therapy in patients with open-angle glaucoma or ocular hypertension.
Brinzolamide Primary Therapy Study Group.
AB - A randomized, multicenter, double-masked, prospective, parallel study was
designed to establish the intraocular pressure (IOP)-lowering efficacy, safety,
and tolerability of brinzolamide 1.0% (Azopt) as a primary therapy compared with
dorzolamide 2.0% (Trusopt) and placebo in patients diagnosed with open-angle
glaucoma (with or without a pseudoexfoliative or a pigmentary dispersion
component) or ocular hypertension. Brinzolamide 1.0%, dosed two times (b.i.d.)
and three times (t.i.d.) a day, dorzolamide 2.0% (t.i.d.), and placebo (t.i.d)
were administered to patients during a 3-month treatment period. Diurnally
corrected IOP reduction from baseline, including peak and trough times, was the
primary end point. Sample sizes were chosen to establish statistical equivalence
between treatments. Mean IOP changes observed on treatment were as follows: -3.4
mm Hg (-13.2%) to -4.1 mm Hg (-16.7%) with brinzolamide 1.0% b.i.d.; -4.1 mm Hg (
16.6%) to -4.8 mm Hg (-19.1%) with brinzolamide 1% t.i.d.; and -4.3 mm Hg (
16.9%) to -4.9 mm Hg (-20.1%) with dorzolamide 2.0%. IOP reductions after
administration of brinzolamide 1.0% b.i.d. and t.i.d. were equivalent to each
other and also clinically and statistically equivalent to those with dorzolamide
2.0% t.i.d. The incidence of ocular discomfort (burning and stinging) upon
instillation was significantly higher for dorzolamide (10.7%) than brinzolamide
(b.i.d. or t.i.d., 3.0% each). The most frequent non-ocular event reported was
taste perversion, which was less (3.7%) with brinzolamide 1.0% b.i.d., but
brinzolamide t.i.d. was similar to dorzolamide t.i.d. (6.8% vs. 5.3%).
Brinzolamide 1.0% b.i.d., brinzolamide 1.0% t.i.d., and dorzolamide 2.0% t.i.d.
equaled each other in IOP-lowering efficacy, and brinzolamide was significantly
more comfortable than dorzolamide upon instillation.
PMID- 10665519
TI - Adjunctive therapy with brinzolamide 1% ophthalmic suspension (Azopt) in patients
with open-angle glaucoma or ocular hypertension maintained on timolol therapy.
AB - This prospective, multicenter, double-masked, placebo-controlled study evaluated
the safety and efficacy of brinzolamide 1% ophthalmic suspension (Azopt) when
used adjunctively with open-label timolol maleate 0.5% (Timoptic). One-hundred
thirty-two patients requiring an adjunctive therapy to timolol 0.5% for the
treatment of open-angle glaucoma or ocular hypertension were randomized to
receive brinzolamide or placebo three times daily (t.i.d.) in addition to timolol
0.5% twice daily (b.i.d.) for 3 months. Qualifying intraocular pressure (IOP) on
timolol 0.5% b.i.d. was 24-36 mm Hg in at least one eye at 8:00 A.M. and 21-36 mm
Hg at 10:00 A.M., with no greater than a 5-mm Hg difference between eyes, during
two eligibility visits separated by at least 7 days. Treatments were compared
using a repeated-measures analysis of variance. Adjunctive therapy with
brinzolamide resulted in clinically and statistically significant reductions in
IOP from the timolol baseline at all visits. IOP changes from a diurnal baseline
ranged from -3.3 mm Hg to -4.1 mm Hg for brinzolamide (N = 53) compared with -0.9
mm Hg to -2.5 mm Hg for placebo (N = 55). Abnormal taste (7.7%) and transient
blurred vision (6.2%) were the most frequently reported adverse events. No
clinically significant differences in the incidence or severity of ocular signs,
visual acuity, cup/disk ratio, or parameters studied on dilated fundus
examination were observed between treatment groups. Brinzolamide 1% t.i.d., used
adjunctively with timolol 0.5% b.i.d., is safe and well tolerated, and produces
clinically and statistically significant additional IOP reductions.
PMID- 10665520
TI - Mitochondrial events in the life and death of animal cells: a brief overview.
AB - Traditionally, mitochondria have been viewed as the "powerhouse" of the cell,
i.e., the site of the oxidative phosphorylation machinery involved in ATP
production. Consequently, much of the research conducted on mitochondria over the
past 4 decades has focused on elucidating both those molecular events involved in
ATP synthesis by oxidative phosphorylation and those involved in the biogenesis
of the oxidative phosphorylation machinery. While monumental achievements have
been made, and continue to be made, in the study of these remarkable but
extremely complex processes essential for the life of most animal cells, it has
been only in recent years that a large body of biological and biomedical
scientists have come to recognize that mitochondria participate in other
important processes. Two of these are cell death and aging which, not
surprisingly, are related processes both involving, in part, the oxidative
phosphorylation machinery. This new awareness has sparked a new and growing area
of mitochondrial research, that has become of great interest to a wide variety of
scientists ranging from those involved in elucidating the role of mitochondria in
cell death and aging to those interested in either suppressing or facilitating
these processes as it relates to identifying new therapies or drugs for human
disease. It is the purpose of this brief introductory review to provide an
overview of those mitochondrial events involved in the life and death of animal
cells and to indicate how these events might relate to the human aging process.
Much more is known, much remains controversial, and even more remains to be
learned as indicated in the excellent set of minireviews that follow.
PMID- 10665521
TI - Mitochondrial dysfunction in the pathogenesis of necrotic and apoptotic cell
death.
AB - Mitochondria are frequently the target of injury after stresses leading to
necrotic and apoptotic cell death. Inhibition of oxidative phosphorylation
progresses to uncoupling when opening of a high conductance permeability
transition (PT) pore in the mitochondrial inner membrane abruptly increases the
permeability of the mitochondrial inner membrane to solutes of molecular mass up
to 1500 Da. Cyclosporin A (CsA) blocks this mitochondrial permeability transition
(MPT) and prevents necrotic cell death from oxidative stress, Ca2+ ionophore
toxicity, Reye-related drug toxicity, pH-dependent ischemia/reperfusion injury,
and other models of cell injury. Confocal fluorescence microscopy directly
visualizes onset of the MPT from the movement of green-fluorescing calcein into
mitochondria and the simultaneous release from mitochondria of red-fluorescing
tetramethylrhodamine methylester, a membrane potential-indicating fluorophore. In
oxidative stress to hepatocytes induced by tert-butylhydroperoxide, NAD(P)H
oxidation, increased mitochondrial Ca2+, and mitochondrial generation of reactive
oxygen species precede and contribute to onset of the MPT. Confocal microscopy
also shows directly that the MPT is a critical event in apoptosis of hepatocytes
induced by tumor necrosis factor-alpha. Progression to necrotic and apoptotic
cell killing depends, at least in part, on the effect the MPT has on cellular ATP
levels. If ATP levels fall profoundly, necrotic killing ensues. If ATP levels are
at least partially maintained, apoptosis follows the MPT. Cellular features of
both apoptosis and necrosis frequently occur together after death signals and
toxic stresses. A new term, necrapoptosis, describes such death processes that
begin with a common stress or death signal, progress by shared pathways, but
culminate in either cell lysis (necrosis) or programmed cellular resorption
(apoptosis) depending on modifying factors such as ATP.
PMID- 10665522
TI - Mitochondria at the crossroad of apoptotic cell death.
AB - In the past few years, it has become widely appreciated that apoptotic cell death
generally involves activation of a family of proteases, the caspases, which
undermine the integrity of the cell by cleavage of critical intracellular
substrates. Caspases, which are synthesized as inactive zymogens, are themselves
caspase substrates and this cleavage leads to their activation. Hence, the
potential exists for cascades of caspases leading to cell death. However, it has
been recently recognized that another, perhaps more prominent route to caspase
activation, involves the mitochondria. Upon receipt of apoptotic stimuli, either
externally or internally generated, cells initiate signaling pathways which
converge upon the mitochondria to promote release of cytochrome C to the
cytoplasm; cytochrome c, thus released, acts as a potent cofactor in caspase
activation. Even cell surface "death receptors" such as Fas, which can trigger
direct caspase activation (and potentially a caspase cascade), appear to utilize
mitochondria as part of an amplification mechanism; it has been recently
demonstrated that activated caspases can cleave key substrates to trigger
mitochondrial release of cytochrome c, thereby inducing further caspase
activation and amplifying the apoptotic signal. Therefore, mitochondria play a
central role in apoptotic cell death, serving as a repository for cytochrome c.
PMID- 10665523
TI - Mitochondrial redox signaling during apoptosis.
AB - The regulatory role of cellular redox state during apoptosis is still
controversial. Early redox signaling can transduce divergent upstream signals to
mitochondria and initiate apoptosis. On the other hand, release of mitochondrial
cytochrome c triggers generation of reactive oxygen species (ROS) and renders
apoptotic cells much more oxidized. Although the sequential caspase activation
does not have apparent redox-sensitive components, redox signaling provides a
separate pathway that is parallel with the caspase cascade. The function of the
apoptosis-associated redox change is uncertain. It could provide positive
feedback mechanisms, such as activating mitochondrial permeability transition and
apoptosis signaling kinase (ASK-1). Since apoptotic cells are designated to be
quickly eliminated, the dramatic cellular oxidation could be involved in the
final degradation of apoptotic bodies and even the termination of the proteolytic
activity after phagocytosis.
PMID- 10665524
TI - Progress on the mitochondrial permeability transition pore: regulation by complex
I and ubiquinone analogs.
AB - This review summarizes recent progress on the regulation of the mitochondrial
permeability transition pore, an inner membrane channel that may play a role in
cell death. We briefly cover its key control points as emerged over the last few
years from studies on isolated mitochondria; and describe in some detail our
recent results indicating that the pore is modulated by the respiratory chain
complex I and can be specifically blocked by selected ubiquinone analogs. We
discuss the potential relevance of these findings for the structural definition
of the permeability transition pore and illustrate the pharmacological
perspectives they offer in diseases where mitochondrial dysfunction is suspected
to play a key role.
PMID- 10665525
TI - Mitochondrial oxygen radical generation and leak: sites of production in states 4
and 3, organ specificity, and relation to aging and longevity.
AB - Studies in heart and nonsynaptic brain mitochondria from two mammals and three
birds show that complex I generates oxygen radicals in heart and nonsynaptic
brain mitochondria in States 4 and 3, whereas complex III does it only in heart
mitochondria and only in State 4. The increase in oxygen consumption during the
State 4 to 3 transition is not accompanied by a proportional increase in oxygen
radical generation. This will protect mitochondria and tissues during bursts of
activity. Comparisons between young and old rodents do not show a consistent
pattern of variation in mitochondrial oxygen radical production during aging.
However, all the interspecies comparisons performed to date between different
mammals, and between mammals and birds, agree that animals with high maximum
longevities have low rates of mitochondrial oxygen radical production,
irrespective of the value of their basal specific metabolic rate. The sites and
mechanisms allowing this, the recently described low degree of membrane fatty
acid unsaturation of longevous animals, and their relation to longevity and aging
are discussed.
PMID- 10665526
TI - Cooperation of a "reactive oxygen cycle" with the Q cycle and the proton cycle in
the respiratory chain--superoxide generating and cycling mechanisms in
mitochondria.
AB - Based on our recent findings concerning the generating, partitioning, targeting,
and functioning of superoxide in mitochondria, a hypothetical model involving a
"reactive oxygen cycle" in the respiratory chain has been proposed (Liu and
Huang, 1991, 1996; Liu et al., 1996; Liu, 1997, 1998) This model emphasizes that
during State 4 respiration, an interaction between an electron leak (a branch of
electron transfer directly from the respiratory chain to form O2*-, but not H2O)
and a proton leak (a branch pathway which utilizes delta muH+ to produce heat,
but not ATP) may take place in cooperation with the Q and proton cycles in
mitochondria through the consumption of H+ by O2*- anions to form a protonated
perhydroxyl radical, HO2, which is directly permeable across the inner
mitochondrial membrane and induces proton leakage and a decrease of delta muH+.
O2*- generation in the mitochondrial respiratory chain and its cycling across the
inner membrane may have the role of an endogenous protonophore in regulating and
partitioning energy transduction and heat production, as well as in pathogenesis
of mitochondrial diseases, aging, and apoptosis. The present article summarizes
the supporting experimental evidence obtained in this laboratory and presents a
brief description of the theoretical basis of this model.
PMID- 10665527
TI - Mitochondrial genome mutation in cell death and aging.
AB - This article reviews the concept, molecular genetics, and pathology of cell death
and aging in relation to mitochondrial genome mutation. Accumulating evidence
emphasizes the role of genetic factors in the development of naturally occurring
cell death and aging. The ATP required for a cell's biological activity is almost
exclusively produced by mitochondria. Each mitochondrion possesses its own DNA
(mtDNA) that codes essential subunits of the mitochondrial energy-transducing
system. Recent studies confirm that mtDNA is unexpectedly fragile to hydroxyl
radical damage, hence to the oxygen stress. Cellular mtDNA easily fragments into
over a hundred-types of deleted mtDNA during the life of an individual.
Cumulative accumulation of these oxygen damages and deletions in mtDNA results in
a defective energy transducing system and in bioenergetic crisis. The crisis
leads cells to the collapse of mitochondrial trans-membrane potential, to the
release of the apoptotic protease activating factors into cytosol, to
uncontrolled cell death, to tissue degeneration and atrophy, and to aging. The
total base sequencing of mtDNA among individuals revealed that germ-line point
mutations transmitted from ancestors accelerate the somatic oxygen damages and
mutations in mtDNA leading to phenotypic expression of premature aging and
degenerative diseases. A practical survey of point mutations will be useful for
genetic diagnosis in predicting the life-span of an individual.
PMID- 10665528
TI - Mitochondrial DNA repair pathways.
AB - It has long been held that there is no DNA repair in mitochondria. Early
observations suggested that the reason for the observed accumulation of DNA
damage in mitochondrial DNA is that DNA lesions are not removed. This is in
contrast to the very efficient repair that is seen in the nuclear DNA.
Mitochondrial DNA does not code for any DNA repair proteins, but it has been
observed that a number of repair factors can be found in mitochondrial extracts.
Most of these participate in the base excision DNA repair pathway which is
responsible for the removal of simple lesions in DNA. Recent work has shown that
there is efficient base excision repair in mammalian mitochondria and there are
also indications of the presence of more complex repair processes. Thus, an
active field of mitochondrial DNA repair is emerging. An understanding of the DNA
repair processes in mammalian mitochondria is an important current challenge and
it is likely to lead to clarification of the etiology of the common mutations and
deletions that are found in mitochondria, and which are thought to cause various
human disorders and to play a role in the aging phenotype.
PMID- 10665529
TI - The stability of porcine rotavirus in feces.
AB - Rotaviruses are known as major causal agents of diarrhea in humans and animals.
They affect young animals in intensive rearing and cause great economic losses.
This study evaluated the infectivity of porcine rotavirus maintained for 32
months at approximately 10 degrees C in the original stool specimens. Thirty
stool specimens of 1-4-week-old piglets from breeding farms located in the
southwest of the State of Parana were selected for this study. They were randomly
chosen from stool samples positive for rotavirus RNA by polyacrylamide gel
electrophoresis (PAGE) at the time of collection. The thirty stool samples
maintained for 32 months were re-tested by PAGE and 11 out of 30 were still
positive showing physical integrity of the eleven segments of viral RNA. In order
to demonstrate the maintenance of viral infectivity processed fecal homogenates
were inoculated in MA-104 cell cultures. After an average of three blind passages
5 out of 11 samples demonstrated cytopathic effect similar to that of a simian
rotavirus (SA-11) used as positive control. To confirm these findings an
immunofluorescence test was performed and typical cytoplasmatic granular
fluorescence was observed. Electron microscopy of stool samples showed that most
of the virus particles were single-shelled and some were found to be in advanced
state of degradation. The viral nucleic acid extracted from six fecal specimens
out of those that showed physical integrity of rotavirus RNA by PAGE were also
amplified when submitted to RT-PCR demonstrating stability of viral RNA. We
therefore concluded that porcine rotavirus infectivity is maintained for a long
period of time in stool specimens at low temperature.
PMID- 10665530
TI - Effects of porcine reproductive and respiratory syndrome virus (isolate tw91) on
porcine alveolar macrophages in vitro.
AB - To verify the role of porcine reproductive and respiratory syndrome virus (PRRSV)
infection on pulmonary defense mechanisms, alterations in the viability,
morphology, and various functions of porcine alveolar macrophages (AMs) were
evaluated in vitro for 2-72 h after exposure to a Taiwan isolate, tw91, at a
multiplicity of infection (MOI) of 0.1. A low but constant rate of infection,
around 5%, was seen in AMs from the PRRSV-infected group throughout the study.
When compared with a mock-infected group, AMs from the PRRSV-infected group had a
significantly lower viability at 18-72 h post-infection (HPI) as determined by
trypan blue dye exclusion. Also during this time period, the cells showed
morphological changes, including rounding, bleb formation, and rupture. The
phagocytic and microbicidal capacity of AMs against Candida albicans was
significantly inhibited after 6 HPI. Although the total amount of superoxide
anion (O2-) and hydrogen peroxide (H2O2) produced by the AMs was reduced after 18
and 12 HPI, respectively, the amount of production was enhanced in both reactive
oxygen species on a per viable cell basis after 12 HPI. In contrast, the level of
bioactive tumor necrosis factor alpha (TNF-alpha) secretion, either total or on a
per viable cell basis, was markedly reduced soon after PRRSV infection, up to 36
HPI, followed by a rebound thereafter. Prostaglandin E2 (PGE2) production was
enhanced, both in total and on a per viable cell basis, in the first 6 h of
infection, especially at 2 HPI. However, it became lower than that of the control
after 36 HPI. The results indicated that PRRSV infection could cause, directly
and/or indirectly, not only death of AMs but also adverse alterations in their
morphology and function, although some of the effects seemed to be reversible.
Because AMs are crucial to the host against airborne pathogens, PRRSV infection
may potentially predispose pigs to secondary pulmonary infections.
PMID- 10665531
TI - Transmission of ovine herpesvirus 2 among adult sheep.
AB - Previous studies from this laboratory have defined the pattern of acquisition of
ovine herpesvirus 2 (OHV-2) in lambs under natural flock conditions. This study
examined the question of whether OHV-2 could be transmitted between adult sheep.
Two potential routes of transmission were examined: (1) direct inoculation of
either viable leukocytes or whole blood from OHV-2 positive sheep, and (2)
horizontal transmission through natural contact with OHV-2 positive sheep. Two
groups of OHV-2 negative adult sheep were inoculated with material from infected
sheep, one with 5x10(8) viable peripheral blood leukocytes (PBL), and the other
with 100 ml of whole peripheral blood. No PCR signals were detected in any of the
three sheep inoculated with the PBL during the 20 weeks following inoculation. In
the group of five sheep inoculated with whole blood, two became PCR-positive at 7
and 8 weeks post-inoculation, respectively, and the remaining three sheep
maintained their negative status until termination of the experiment at 20 weeks
post-inoculation. In two experiments conducted in different flocks, a total of 20
adult sheep were used to examine horizontal transmission by contact; all animals
became PCR-positive within 12 months of mixing the uninfected and infected
animals. The results of these experiments support two conclusions. First, the
susceptibility to OHV-2 is not limited to young lambs; adult sheep remain fully
susceptible. Second, the fact that whole blood, but not PBL, from infected sheep
was able to transmit the infection to only two of five inoculated sheep suggests
that the infection in peripheral blood cells may be largely non-productive.
PMID- 10665532
TI - Development and validation of a monoclonal antibody blocking ELISA for the
detection of antibodies against both equine herpesvirus type 1 (EHV1) and equine
herpesvirus type 4 (EHV4).
AB - A monoclonal antibody blocking ELISA was developed for the detection of
antibodies directed against either EHV1 or EHV4. For this purpose, we selected a
monoclonal antibody directed against a cross-reactive, conservative and
immunodominant epitope of both EHV1 and EHV4. High antibody titres were found in
rabbit antisera and SPF-foal antisera infected with either EHV1 or EHV4. After
experimental challenge of conventional horses with EHV1 or EHV4 significant
increases in CF and ELISA titres were found, whereas VN antibodies did not always
increase significantly. In 344 paired serum samples submitted for diagnostic
purposes a good agreement (kappa = 0.75, confidence limits = 0.63-0.88) was found
between VN test and ELISA regarding a significant increase in titres. Also, a
good correlation was found between VN and ELISA titres (r = 0.76, p<<0.0005). The
relative sensitivity and specificity of the Mab blocking ELISA as compared with
the VN test were 99.9 and 71%, respectively. The rather low relative specificity
of the ELISA may be explained by a relatively low sensitivity of the VN test. The
ELISA also detected increases in titre after vaccination with an EHV1 subunit
vaccine, and after primary field infections in weaned foals. We concluded that
the Mab blocking ELISA is more sensitive, easier to perform, more rapid and more
reproducible than the VN test. We consider this test as a valuable tool for
serological diagnosis of both EHV1 and EHV4 infections.
PMID- 10665533
TI - Phylogenetic relationships of Staphylococcus aureus from bovine mastitis based on
coagulase gene polymorphism.
AB - Coagulase gene restriction fragment length polymorphism (RFLP) patterns were
analyzed to determine the phylogenetic relationship among isolates of
Staphylococcus aureus from the Czech Republic (n = 27), France (n = 48), Korea (n
= 115) and the United States (n = 278). A total of 468 isolates of S. aureus were
subtyped into 41 coagulase genotypes. Cluster analysis placed the 41 types into
nine clusters. Eighteen API Staph profiles were determined for 102 S. aureus
isolates representing 1 to 4 isolates of each coagulase type. The results of the
study suggest that based on coagulase gene RFLP analysis, several genetic
variants of S. aureus are prevalent. Comparison of coagulase and API Staph
profiles indicated that the two identification system were independent of each
other.
PMID- 10665534
TI - Isolation of Campylobacter species from zoo animals and polymerase chain reaction
based random amplified polymorphism DNA analysis.
AB - A total of 104 fecal specimens from 30 mammals, 12 birds, and 3 reptiles at the
Phoenix Zoological Gardens, Miyazaki City, Japan, were examined for the presence
of Campylobacter species. All the animals examined were healthy with no fecal
abnormality. Twenty-three (22.1%) thermophilic campylobacters, (9 C. jejuni, 11
C. hyointestinalis, 2 C. coli, and 1 C. lari), were isolated from 11 animals (7
mammals and 4 birds). C. jejuni and C. hyointestinalis were the predominant
species isolated from these zoo animals and C. hyointestinalis was isolated
frequently from simians. As selective media influence the numbers and species of
campylobacters isolated, the agar medium was not supplemented with cephalothin.
Campylobacters were isolated most frequently when a combination of enrichment
culture and selective agar plating was performed at 42 degrees C. For the
epidemiological study, a polymerase chain reaction (PCR)-based randomly amplified
polymorphic DNA (RAPD) method was used as a tool to detect the heterogeneity of
amplified DNAs of Campylobacter spp. isolated from zoo animals. The two arbitrary
primers used in this study enabled even closely related strains of the same
Campylobacter spp. to be differentiated. RAPD analysis revealed considerable
diversity among the strains, suggesting that the transmission of Campylobacter
spp. among animals in a defined area occurred through different mechanisms.
Examination of the genotypic diversity among the multiple clones from the same
host also revealed differences between clones. These results demonstrate that
campylobacter populations in zoo animals are highly divergent.
PMID- 10665535
TI - The association of two recombinant proteinases of a feline strain of
Porphyromonas gingivalis with periodontal disease in cats.
AB - Serum from 40 domestic cats with various grades of periodontal disease was used
to probe two recombinant functional proteinases from feline strain VPB 3457 of
Porphyromonas gingivalis expressed in E. coli. One recombinant proteinase (VPB
2856) was constructed using polymerase chain reaction and had 91% DNA identity
with the prtC collagenase gene of the human type strain of P. gingivalis, while
the other proteinase (VPB 2814) was isolated from a size selected genomic library
and had an amino-terminal sequence with no significant identity with deposited
sequences. Thirteen of 40 cats showed a serum antibody response to VPB 2856 using
Western immunoblot detection. All the 13 cats had an overall periodontal grade of
3 or greater and greater than 1.68x10(5) cfu P. gingivalis at the canine and
premolar periodontium sample sites. Fourteen of 40 cats showed a serum antibody
response to VPB 2814. Thirteen of these 14 cats had an overall periodontal grade
of 3 or greater. Regression analysis of overall periodontal grade against the
serum antibody response showed significant positive relationships for both VPB
2856 (r2 = 0.351; p<0.001) and VPB 2814 (r2 = 0.247; p<0.001). Regression
analysis of the total colony forming units of feline strain P. gingivalis against
the grade of serum antibody response showed a positive relationship for both VPB
2856 (r2 = 0.662; p<0.001) and VPB 2814 (r2 = 0.531; p<0.001). These data provide
strong evidence that the recombinant proteinases of feline P. gingivalis
expressed in E. coli clones VPB 2856 and VPB 2814 are associated with periodontal
disease in cats.
PMID- 10665536
TI - Evaluation of an indirect enzyme-linked immunosorbent assay (ELISA) for detection
of antibodies to the Apx toxins of Actinobacillus pleuropneumoniae.
AB - The reference strains of the 12 serotypes of Actinobacillus pleuropneumoniae
express one or two of three different RTX exotoxins designated Apx I, Apx II and
Apx III. The toxins are important virulence factors. In the present study, ELISAs
with purified Apx I, Apx II and Apx III, respectively, as antigen were evaluated
as candidates for serological diagnosis of Actinobacillus pleuropneumoniae
infection in pigs. The pigs were inoculated with biotype 1, serotypes 1-12, and
biotype 2, serotype 14, respectively. A strong humoral antibody response was seen
to all the three antigens in most pigs irrespective of the serotype used for
inoculation. However, titers to the exotoxins secreted by the serotype used for
inoculation were generally highest. The results show that toxin proteins of
Actinobacillus pleuropneumoniae are antigenically related and that a correlation
between serotype and secretion of exotoxin is not revealed serologically in the
ELISA test.
PMID- 10665537
TI - The dynamics of Staphylococcus aureus intramammary infection in nine Danish dairy
herds.
AB - The aim of the present study was to examine the diversity of Staphylococcus
aureus isolates from bovine intramammary infections (IMI) in nine dairy herds,
and compare these with isolates from other sites on the cows by phage- and
ribotyping. Whether colonisation of milkers with S. aureus could be a source of
infection for bovine IMI was investigated. In addition, 100 epidemiologically
unrelated S. aureus isolates from asymptomatic human carriers were also phage-
and ribotyped to compare the human and bovine reservoir of S. aureus in Denmark.
A total of 625 S. aureus isolates from bovine IMI, bovine skin lesions, milking
personnel, and non-farm-related human carriers were included in the study.
Certain types predominated in one or several herds during the study period of one
and-a-half to two years, whereas the presence of other types was of a more
sporadic nature. Within the individual herds, there was a close correspondence
between ribo- and phage types of S. aureus isolated from bovine intramammary
infections and skin lesions. Isolates from milking personnel, however, were not
identical to any of the predominant intramammary strains. Furthermore, several of
the isolates from milking personnel showed ribo- and phage patterns identical to
S. aureus isolates from human carriers. The findings of the present study
underline the importance of strict milking hygiene and improvement of current
mastitis therapy. The results support the hypothesis that some S. aureus mastitis
strains are more contagious, virulent or persistent than others. The human
reservoir of S. aureus does not play a major role as a source of bovine
intramammary infections.
PMID- 10665538
TI - Genomic fingerprinting of pigeon Streptococcus gallolyticus strains of different
virulence by randomly amplified polymorphic DNA (RAPD) analysis.
AB - Randomly amplified polymorphic DNA (RAPD) analysis was performed on 95 pigeon S.
gallolyticus strains of different virulence and belonging to different biotypes
and different culture supernatant phenotypes as determined by SDS-PAGE. Four
distinct RAPD patterns, designated A, B, C and D, were distinguished using primer
OPM6 (5'CTGGGCAACT). All 76 strains generating RAPD pattern A or B were
designated highly virulent on the basis of their SDS-PAGE pattern. Five of seven
strains generating RAPD pattern C and 11 of 12 strains generating RAPD pattern D
belonged to the moderately virulent and low virulent culture supernatant
phenotype groups, respectively. Only one RAPD group C strain belonged to a highly
virulent culture supernatant phenotype group. There was a correlation between
biotype and RAPD patterns. These findings indicate that there is a high
correlation between RAPD pattern and virulence for pigeons. Therefore, RAPD
typing seems a rapid, reliable method to distinguish pigeon S. gallolyticus
strains of high, moderate and low virulence.
PMID- 10665539
TI - Extensive diversity in New Zealand Dichelobacter nodosus strains from infected
sheep and goats.
AB - Footrot is a contagious bacterial disease of ruminants spread by the Gram
negative, anaerobic organism, Dichelobacter nodosus. It is endemic in New Zealand
and throughout sheep and goat farming regions of the world. Using the polymerase
chain reaction (PCR) to amplify fragments of the fimbrial gene (fimA), D. nodosus
was detected in 14 hoof scrapings, sampled from six farming regions within New
Zealand. DNA sequencing revealed 15 strains covering eight serogroups on the New
Zealand farms. The predominant serogroup was B which contained six strains,
followed by serogroups F, H and G. No strains from serogroups D and I were
detected in this investigation. Eleven out of the 15 D. nodosus strains had
fimbriae sequences different to those previously reported and the presence of
multiple strains on a single hoof was common (86% samples). Individual sheep from
the same farm, or the same paddock, were often infected by a different range of
strains, which suggests a host role in mediating footrot infection.
PMID- 10665540
TI - A longitudinal study of Shiga-toxigenic Escherichia coli (STEC) prevalence in
three Australian diary herds.
AB - Over a 12 month period, 588 cattle faecal samples and 147 farm environmental
samples from three dairy farms in southeast Queensland were examined for the
presence of Shiga-toxigenic Escherichia coli (STEC). Samples were screened for
Shiga toxin gene (stx) using PCR. Samples positive for stx were filtered onto
hydrophobic grid membrane filters and STEC identified and isolated using colony
hybridisation with a stx-specific DNA probe. Serotyping was performed to identify
serogroups commonly associated with human infection or enterohaemorrhagic
Escherichia coli (EHEC). Shiga-toxigenic Escherichia coli were isolated from
16.7% of cattle faecal samples and 4.1% of environmental samples. Of cattle STEC
isolates, 10.2% serotyped as E. coli O26:H11 and 11.2% serotyped as E. coli
O157:H7, and the E. coli O26:H11 and E. coli O157:H7 prevalences in the cattle
samples were 1.7 and 1.9%, respectively. Prevalences for STEC and EHEC in dairy
cattle faeces were similar to those derived in surveys within the northern and
southern hemispheres. Calves at weaning were identified as the cattle group most
likely to be shedding STEC, E. coli O26 or E. coli O157. In concurrence with
previous studies, it appears that cattle, and in particular 1-14-week-old
weanling calves, are the primary reservoir for STEC and EHEC on the dairy farm.
PMID- 10665541
TI - Evaluation of a 23S rDNA polymerase chain reaction assay for identification of
Serpulina intermedia, and strain typing using pulsed-field gel electrophoresis.
AB - A polymerase chain reaction assay, amplifying a 1027 base pair portion of the 23S
rDNA gene, was evaluated for identification of the intestinal spirochaete
Serpulina intermedia. A total of 34 strains of S. intermedia isolated from pigs
and chickens and 195 strains of other related species were tested. The optimised
assay correctly identified all the S. intermedia strains, but generated 11 false
positive reactions, giving a test sensitivity of 100% and a test specificity of
94.3%. The false positive reactions were generated from strains of four different
species of intestinal spirochaetes, and the product was of the original predicted
size. This suggests that the primer sites selected on the 23S rRNA gene were not
completely specific for S. intermedia. Pulsed-field gel electrophoresis was then
developed to investigate diversity amongst the S. intermedia strains. All strains
tested had distinct DNA banding patterns using Mlu1, although three isolates from
chickens on the same farm appeared closely related. The collection exhibited
considerable genetic diversity, and strains from pigs and chickens were
distributed in clusters throughout the dendrogram produced. The most closely
related porcine and avian strains shared only 62% similarity.
PMID- 10665542
TI - Monoclonal antibodies suitable for incorporation into a competitive enzyme-linked
immunosorbent assay (ELISA) for detection of specific antibodies to Leptospira
interrogans serovar pomona.
AB - Monoclonal antibodies (mAb) were produced by fusing Sp2/0-Ag14 myeloma cells with
spleen cells from BALB/c and ND4 mice that were immunized with killed Leptospira
interrogans serovar pomona whole cells. Thirty hybridomas which produced
antibodies (of the IgG1, IgG2a, IgG2b, or IgG3 isotype) that bound to epitopes on
the serovar pomona whole cell antigen were identified by an indirect enzyme
linked immunosorbent assay (ELISA). Twenty-eight of these 30 mAbs cross-reacted
in the indirect ELISA with at least one whole cell antigen prepared from 12 other
pathogenic Leptospira serovars, and/or with whole cell antigen from the non
pathogenic Leptospira biflexa serovar patoc. The two serovar pomona-specific
mAbs, which were designated M897 and M898, were obtained from the ND4 mouse and
were both of the IgG1 isotype. In competitive ELISAs, M897 and M898 were
inhibited from binding to the pomona antigen by bovine sera with anti-serovar
pomona microscopic agglutination test (MAT) titres ranging from 100 to 6400. No
significant inhibition was observed with pomona MAT-negative sera or with sera
from animals experimentally infected with serovars canicola, copenhageni,
grippotyphosa, hardjo type hardjobovis or sejroe. The epitopes recognized by M897
and M898 were both highly susceptible to sodium meta-periodate oxidation,
indicating a carbohydrate composition. Neither of these mAbs reacted in
immunoblots with the separated components of the serovar pomona whole cell
antigen.
PMID- 10665543
TI - Evaluation of three Brucella soluble antigens used in an indirect Elisa to
discriminate S19 vaccinated from naturally infected cattle.
AB - An O-polysaccharide (O-chain) and a hot-water extracted polysaccharide (PS), both
obtained from Brucella abortus 1119-3, and a B. melitensis 16M native hapten (NH)
were evaluated by indirect enzyme linked immunosorbent assay (ELISA) on three
groups of cattle sera. The sera tested were: (a) 75 sera from cows naturally
infected with B. abortus; (b) 130 sera from non-infected and non-vaccinated
cattle; and (c) 61 sera from non-infected heifers recently vaccinated with B.
abortus Strain 19 (S19). Sensitivity (Se), specificity (Sp) and the capability to
discriminate vaccinated cattle (ADV) were determined. Using PS antigen, Se was
100% and the Sp was 97.7%, while the highest Sp was obtained by using the O-chain
(99.2% ). For the NH antigen, Se was 94.7% and the Sp was 90.0%. The ADV of the
three antigens was approximately 85%. Statistical analysis showed significant
differences between O-chain/PS and O-chain/NH antigens. The agreement among
antigens determined by kappa coefficient was 0.899 for O-chain/PS, 0.845 for O
chain/NH and 0.795 for PS/NH.
PMID- 10665544
TI - A metalloprotease is common to swine, avian and bovine isolates of Staphylococcus
hyicus.
AB - Staphylococcus hyicus is considered to be an etiological agent of exudative
epidermitis in young pigs, but is frequently isolated from chickens and cows. In
the present study, the proteases of 58 S. hyicus isolates from pigs, chickens and
cows were examined by skim milk agar plate culture, gelatinolytic zymogram and
polymerase chain reaction (PCR). These isolates showed proteolytic activity on
skim milk agar plate, but activity differed amongst the isolates. In the
gelatinolytic zymogram, one main band was observed in all the porcine, avian and
bovine isolates, while one to two other bands were recognized in some isolates.
The formation of the main band was inhibited by EDTA, suggesting that this
protease is a metalloprotease. When the Shp1 gene, which codes for one the
metalloproteases of S. hyicus as reported previously, was examined by PCR, one
band arising from an open reading frame (ORF) was detected in all of 58 isolates
tested. In addition, upstream nucleotides containing the promoter region of Shp1
gene were amplified and sequenced. From these results, it seems likely that the
metalloprotease is common to porcine, avian and bovine isolates of S. hyicus.
PMID- 10665545
TI - Gene therapy under cloud.
PMID- 10665546
TI - Difficulties with oral platelet glycoprotein IIb/IIIa receptor antagonists.
PMID- 10665547
TI - Prevention of transfusion-transmitted hepatitis.
PMID- 10665548
TI - Transmission of Helicobacter pylori: is it all child's play?
PMID- 10665549
TI - Antithrombotic drug therapy after infrainguinal vascular surgery.
PMID- 10665550
TI - Seizures and epilepsy after traumatic brain injury.
PMID- 10665551
TI - UK and US health-care systems: divided by more than a common language.
PMID- 10665552
TI - Comparison of sibrafiban with aspirin for prevention of cardiovascular events
after acute coronary syndromes: a randomised trial. The SYMPHONY Investigators.
Sibrafiban versus Aspirin to Yield Maximum Protection from Ischemic Heart Events
Post-acute Coronary Syndromes.
AB - BACKGROUND: Aspirin lowers risks of death and myocardial infarction in patients
with acute coronary syndromes. Intravenous glycoprotein IIb/IIIa receptor
antagonists further reduce the rates of ischaemic events in these patients, but
the efficacy of long-term oral glycoprotein IIb/IIIa receptor blockade has not
been established. We tested whether the oral glycoprotein IIb/IIIa receptor
antagonist sibrafiban would prevent more cardiovascular events than aspirin, when
given within 7 days of, and sustained for 90 days after, an acute coronary
syndrome event. METHODS: 9233 patients who had stabilised after an acute coronary
syndrome event were randomly assigned aspirin (80 mg orally twice daily) or low
dose or high-dose sibrafiban. Sibrafiban doses (3.0 mg, 4.5 mg, or 6.0 mg) were
based on a model accounting for weight and serum creatinine and designed to
achieve at least 25% steady-state inhibition of platelet aggregation (low dose)
or at least 50% inhibition (high dose). The primary endpoint was the composite of
death, non-fatal infarction or reinfarction, or severe recurrent ischaemia at 90
days. Analysis was by intention to treat. FINDINGS: The 90-day rate of the
primary endpoint did not differ significantly between the groups assigned aspirin
(302 [9.8%]), low-dose sibrafiban (310 [10.1%]; odds ratio 1.03 [95% CI 0.87
1.21]), and high-dose sibrafiban (303 [10.1%]; 1.03 [0.87-1.21]). The groups did
not differ significantly in the rates of the component events or secondary
efficacy endpoints. Major bleeding was more common with high-dose sibrafiban (171
[5.7%]) than with aspirin (120 [3.9%]) or low-dose sibrafiban (159 [5.2%]).
INTERPRETATION: Sibrafiban showed no additional benefit over aspirin for
secondary prevention of major ischaemic events after an acute coronary syndrome,
and was associated with more dose-related bleeding.
PMID- 10665553
TI - Efficacy of oral anticoagulants compared with aspirin after infrainguinal bypass
surgery (The Dutch Bypass Oral Anticoagulants or Aspirin Study): a randomised
trial.
AB - BACKGROUND: Oral anticoagulants and aspirin are antithrombotic drugs that are
commonly used in patients with vascular disease. We investigated whether either
of these treatments prevented more effectively than the other bypass
complications after infrainguinal bypass surgery. METHODS: We did a multicentre,
randomised, open trial. 2690 patients who had undergone infrainguinal grafting
were randomly assigned oral anticoagulants (target international normalised ratio
3.0-4.5, n=1339) or aspirin (80 mg daily, n=1351). We followed up patients for a
mean of 21 months. The primary outcome was graft occlusion. FINDINGS: 308 graft
occlusions occurred in the oral-anticoagulants group compared with 322 in the
aspirin group (hazard ratio 0.95 [95% CI 0.82-1.11]), which suggested no overall
advantage for either treatment. Oral anticoagulants were beneficial in patients
with vein grafts (0.69 [0.54-0.88]), whereas aspirin had better results for
nonvenous grafts (1.26 [1.03-1.55]). The composite outcome of vascular death,
myocardial infarction, stroke, or amputation occurred 248 times in the oral
anticoagulants group and 275 times in the aspirin group (0.89 [0.75-1.06]).
Patients treated with oral anticoagulants had more major bleeding episodes than
those treated with aspirin (108 vs 56; 1.96 [1.42-2.71]). INTERPRETATION: Oral
anticoagulation was better for the prevention of infrainguinal-vein-graft
occlusion and for lowering the rate of ischaemic events. Aspirin was better for
the prevention of non-venous graft occlusion, and was associated with fewer
bleeding episodes.
PMID- 10665554
TI - Efficacy of artesunate plus pyrimethamine-sulphadoxine for uncomplicated malaria
in Gambian children: a double-blind, randomised, controlled trial.
AB - BACKGROUND: Resistance to cheap effective antimalarial drugs, especially to
pyrimethaminesulphadoxine (Fansidar), is likely to have a striking impact on
childhood mortality in sub-Sharan Africa. The use of artesunate (artesunic acid)
[corrected] in combination with pyrimethamine-sulphadoxine may delay or prevent
resistance. We investigated the efficacy, safety, and tolerability of this
combined treatment. METHODS: We did a double-blind, randomised, placebo
controlled trial in The Gambia. 600 children with acute uncomplicated Plasmodium
falciparum malaria, aged 6 months to 10 years, at five health centres were
randomly assigned pyrimethaminesulphadoxine (25 mg/500 mg) with placebo;
pyrimethamine-sulphadoxine plus one dose of artesunate (4mg/kg bodyweight); or
pyrimethamine-sulphadoxine plus one dose 4 mg/kg bodyweight artesunate daily for
3 days. Children were visited at home each day after the start of treatment until
parasitaemia had cleared. FINDINGS: The combined treatment was well tolerated. No
adverse reactions attributable to treatment were recorded. By day 1, only 178
(47%) of 381 children treated with artesunate were still parasitaemic, compared
with 157 (81%) of 195 children in the pyrimethamine-sulphadoxine alone group
(relative risk 1.7 [95% CI 1.5-2.0], p<0.001). Treatment-failure rates at day 14
were 3.1% in the pyrimethamine sulphadoxine alone group, and 3.7% in the one-dose
artesunate group (risk difference -0.6% [-4.2 to 3.0]) and 1.6% in the three-dose
group (1.5 [1.5-4.5], p=0.048). Symptoms resolved faster in children who received
artesunate, but there was no additional benefit for three doses of artesunate
over one dose. Children given artesunate were less likely to be gametocytaemic
after treatment. INTERPRETATION: The combined treatment was safe, well tolerated,
and effective. The addition of artesunate to malaria treatment regimens in Africa
results in lower gametocyte rates and may lower transmission rates.
PMID- 10665555
TI - Transmission of Helicobacter pylori among siblings.
AB - BACKGROUND: Helicobacter pylori infection causes chronic digestive diseases with
a major public-health impact, yet the design of prevention measures is hampered
by limited knowledge of transmission pathways. We studied the effect of family
composition on H. pylori prevalence among rural Colombian children aged 2-9
years. METHODS: 684 children were screened for H. pylori with the 13C-urea breath
test. For each child, birth order, birth spacing, number of 2-9-year-old
siblings, and number of H-pylori-positive 2-9-year-old siblings was recorded.
Odds ratios were estimated by logistic regression, controlling for hygiene
related exposures, socioeconomic indicators, and the number of children in the
household. FINDINGS: The odds of infection increased with the number of 2-9-year
old siblings in the household (odds ratios 1.4, 2.3, 2.6, and 4.3 for one, two,
three, and four to five siblings, respectively). Compared with first-born
children, odds ratios for children born second and third to ninth were 1.8 (95%
CI 1.0-3.3) and 2.2 (1.0-4.3), respectively. Compared with children born 10 or
more years after the next older household member, those born within 4 years were
4.1 times (CI 2.0-8.6) more likely to be infected; the age gap to the next
younger household member displayed a weaker effect. The number of H-pylori
positive 2-9-year-old siblings had a particularly strong effect gradient (1.5,
3.2, 5.6, and 7.1, for one, two, three, and four positive siblings,
respectively). INTERPRETATION: Among rural Andean children younger than 10 years,
H. pylori infection seems to be transmitted most readily among siblings who are
close in age, and most frequently from older siblings to younger ones.
PMID- 10665556
TI - Results at 1 year of outpatient multidisciplinary pulmonary rehabilitation: a
randomised controlled trial.
AB - BACKGROUND: Pulmonary rehabilitation seems to be an effective intervention in
patients with chronic obstructive pulmonary disease. We undertook a randomised
controlled trial to assess the effect of outpatient pulmonary rehabilitation on
use of health care and patients' wellbeing over 1 year. METHODS: 200 patients
with disabling chronic lung disease (the majority with chronic obstructive
pulmonary disease) were randomly assigned a 6-week multidisciplinary
rehabilitation programme (18 visits) or standard medical management. Use of
health services was assessed from hospital and general-practice records. Analysis
was by intention to treat. FINDINGS: There was no difference between the
rehabilitation (n=99) and control (n=101) groups in the number of patients
admitted to hospital (40 vs 41) but the number of days these patients spent in
hospital differed significantly (mean 10.4 [SD 9.7] vs 21.0 [20.7], p=0.022). The
rehabilitation group had more primary-care consultations at the general
practitioner's premises than did the control group (8.6 [6.8] vs 7.3 [8.3],
p=0.033) but fewer primary-care home visits (1.5 [2.8] vs 2.8 [4.6], p=0.037).
Compared with control, the rehabilitation group also showed greater improvements
in walking ability and in general and disease-specific health status.
INTERPRETATION: For patients chronically disabled by obstructive pulmonary
disease, an intensive, multidisciplinary, outpatient programme of rehabilitation
is an effective intervention, in the short term and the long term, that decreases
use of health services.
PMID- 10665557
TI - Clinical presentation and outcome of Pneumocystis carinii pneumonia in Malawian
children.
AB - BACKGROUND: Necropsy studies from Africa have shown that Pneumocystis carinii
pneumonia (PCP) is common in infants with HIV infection. We aimed to describe the
rate, clinical presentation, and outcome of PCP in young Malawian children with
acute severe pneumonia. METHODS: Children aged between 2 months and 5 years who
were in hospital with a diagnosis of severe pneumonia were admitted to a study
ward for clinical monitoring. We carried out blood culture, immunofluorescence on
nasopharyngeal aspirate samples to test for PCP, polymerase chain reaction to
detect HIV, and chest radiography. FINDINGS: 16 cases of PCP were identified
among 150 children with radiologically confirmed severe pneumonia. All were HIV
positive and younger than 6 months. 21 children had bacterial pneumonia
(including one who was also PCP positive) and 114 were not confirmed. The most
common bacterial pathogens among children without PCP were Streptococcus
pneumoniae (eight) and non-typhoidal salmonellae (seven). On admission, children
with confirmed PCP had a lower mean age, body temperature, and oxygen saturation
than children with bacterial pneumonia and were less likely to have a focal
abnormality on auscultation. Oxygen requirements were much greater in children
with PCP than those with bacterial pneumonias (96 of 105 hospital days vs 15 of
94, p<0.0001). Ten of 16 children with PCP and six of 21 with bacterial pneumonia
died (relative risk 2.19 [95% CI 1.0-4.7]). The overall case-fatality rate of
severe pneumonia was 22%. In addition to a strong association with PCP, a fatal
outcome was significantly and independently associated with HIV infection (2.98
[1.1-7.9]) and with age under 6 months (2.76 [1.0-5.2]). INTERPRETATION: PCP is
common and contributes to the high mortality from pneumonia in Malawian infants.
Clinical features are helpful in diagnosis. The study highlights the impact of
HIV infection and difficult issues of management in countries with few resources.
PMID- 10665558
TI - Confused by arteritis.
PMID- 10665559
TI - Resuscitation from accidental hypothermia of 13.7 degrees C with circulatory
arrest.
AB - In a victim of very deep accidental hypothermia, 9 h of resuscitation and
stabilisation led to good physical and mental recovery. This potential outcome
should be borne in mind for all such victims.
PMID- 10665560
TI - Sirolimus-tacrolimus combination immunosuppression.
AB - A series of 32 recipients of liver, kidney, or pancreas transplants who were
treated with sirolimus and low-dose tacrolimus experienced a low rate of
rejection and excellent graft function without drug-related toxic effects.
PMID- 10665561
TI - Helicobacter pylori and epidemic Vibrio cholerae O1 infection in Peru.
AB - In a cross-sectional study of the 1991 Peruvian cholera epidemic, Vibrio cholerae
O1 infection was associated with Helicobacter pylori infection, particularly in
young children. These data support the hypothesis that hypochlorhydria induced by
H. pylori is important in the pathogenesis of diarrhoeal disease.
PMID- 10665562
TI - Inflammatory bowel disease in non-Ashkenazi Jews with familial Mediterranean
fever.
AB - Familial Mediterranean fever and inflammatory bowel disease are two inflammatory
conditions. We showed that inflammatory bowel disease was particularly frequent
and severe in non-Ashkenazi Jewish patients with familial Mediterranean fever.
PMID- 10665563
TI - Dopamine-transporter density in nucleus accumbens of type-1 alcoholics.
AB - We have shown that alcoholic patients have a lower number of dopamine
transporters in the nucleus accumbens, which mediates the rewarding effects of
addictive drugs. Thus, certain dopaminergic agents may be beneficial in the
treatment of alcohol withdrawal and in the long-term treatment of alcoholism with
selective use.
PMID- 10665564
TI - Earliest stages of tumour-induced angiogenesis dissected.
PMID- 10665565
TI - The balance of risk and benefit in gene-therapy trials.
PMID- 10665567
TI - WHO assembles leading economists to study poverty reduction and health.
PMID- 10665566
TI - At last, the fight against lymphatic filiariasis begins.
PMID- 10665568
TI - UK allows frozen eggs for fertility treatment.
PMID- 10665569
TI - Mitochondrial respiratory chain disorders II: neurodegenerative disorders and
nuclear gene defects.
AB - The first part of this review (Lancet 2000; 355: 299) covered primary disorders
of mitochondrial DNA (mtDNA). This section will cover nuclear-encoded defects of
the oxidative phosphorylation (OXPHOS) system, including mtDNA mutations that are
secondary to nuclear gene mutations and nuclear gene defects responsible for
secondary OXPHOS deficiency (panel). The latter group of diseases are
predominantly neurodegenerative. The mitochondrion's role in apoptosis and its
contribution to the pathogenesis of neurodegenerative diseases are also covered.
PMID- 10665570
TI - Surveillance after colorectal cancer resection.
PMID- 10665571
TI - Condoms and seat belts: the parallels and the lessons.
PMID- 10665572
TI - Psychological response and survival in breast cancer.
PMID- 10665573
TI - Psychological response and survival in breast cancer.
PMID- 10665574
TI - Psychological response and survival in breast cancer.
PMID- 10665575
TI - Psychological response and survival in breast cancer.
PMID- 10665576
TI - Psychological response and survival in breast cancer.
PMID- 10665577
TI - Prophylactic antidepressant treatment before patients are admitted.
PMID- 10665578
TI - Hyperemesis gravidarum and sex of child.
PMID- 10665579
TI - Hyperemesis gravidarum and sex of child.
PMID- 10665580
TI - Xenotransplantation debate.
PMID- 10665581
TI - Xenotransplantation debate.
PMID- 10665582
TI - Autism and measles, mumps, and rubella vaccine.
PMID- 10665583
TI - Cervical screening.
PMID- 10665584
TI - Cervical screening.
PMID- 10665585
TI - Cervical screening.
PMID- 10665586
TI - Cervical screening.
PMID- 10665587
TI - Polycystic ovarian disease: a misleading label?
PMID- 10665588
TI - Aortic pulse-wave velocity versus pulse pressure and pulse-wave analysis.
PMID- 10665589
TI - General anaesthesia in dental treatment.
PMID- 10665590
TI - Bias against publication of surgical papers.
PMID- 10665591
TI - Probiotics strain for credibility.
PMID- 10665592
TI - Do genetically modified foods affect human health?
PMID- 10665593
TI - Trap-door medicine.
PMID- 10665594
TI - Linus Pauling: an inspirational and humane genius.
PMID- 10665595
TI - The Nobel chronicles. 1985: Joseph Leonard Goldstein (b 1940), Michael Stuart
Brown (b 1941).
PMID- 10665596
TI - Testing adolescents for a hereditary breast cancer gene (BRCA1): respecting their
autonomy is in their best interest.
AB - The testing of individuals before the age of 18 years for hereditary late-onset
diseases has been judged ethically not acceptable in guidelines and directives
published by medical professional organizations. However, there are not enough
best interest arguments to deny genetic testing to an adolescent at risk of
carrying a BRCA1 mutation, even if the competence of adolescents for medical
decisions is considered to be lower than the competence of adults. The
adolescent's decision is not irrational or of very high risk. Respecting
adolescents' autonomous choices concerning genetic testing has positive
consequences for their self-esteem and psychological health. Geneticists and
other professionals should clearly differentiate between children and adolescents
in regard to BRCA1 gene testing and recommend giving decision autonomy about the
test to all psychologically "normal" adolescents.
PMID- 10665597
TI - Subspecialty referrals for pauciarticular juvenile rheumatoid arthritis.
AB - OBJECTIVES: To examine referral patterns from primary care physicians for
children with pauciarticular juvenile rheumatoid arthritis (JRA) and to determine
whether children with pauciarticular JRA referred to pediatric rheumatologists
differ in clinical presentation from children referred to other specialists.
DESIGN: A retrospective records review of 49 patients with pauciarticular jRA was
performed. Records were reviewed to determine the specialty of the referring
physician and whether the children referred had symptoms and signs compatible
with a synovitis at the time primary care was sought. SETTING: Inner-city
tertiary pediatric rheumatology referral center. PARTICIPANTS: Children with
pauciarticular JRA. MAIN OUTCOME MEASURES: Identification of referral patterns of
primary care physicians. Associated morbidity owing to JRA was ascertained at the
time of referral. RESULTS: Most children with pauciarticular JRA (62%) were
referred to orthopedic surgeons prior to referral for pediatric rheumatology
care. No differences in clinical symptoms were seen between children referred to
pediatric rheumatologists and those referred to orthopedic surgeons. Children
referred initially to orthopedic surgeons were younger than those referred to
pediatric rheumatologists. CONCLUSION: A notable number of children with
pauciarticular JRA are referred to orthopedic surgeons prior to the establishment
of that diagnosis, even when such children present with unequivocal signs of
synovitis. This may be owing to the misconception that arthritis is rare in
preschool-aged children or to the difficulty of ascertaining the presence of
synovitis in younger children.
PMID- 10665598
TI - Prevalence of and risks for cervical human papillomavirus infection and squamous
intraepithelial lesions in adolescent girls: impact of infection with human
immunodeficiency virus.
AB - CONTEXT: Data suggest that in adults, human papillomavirus (HPV) infections and
their sequalae, squamous intraepithelial lesions (SILs), occur more commonly
among human immunodeficiency (HIV)-infected women because of the HIV-associated
CD4+ T-cell immunosuppression. Since adolescents are more likely to be early in
the course of HIV and HPV infections, the study of both infections in this age
group may help elucidate their initial relationship. OBJECTIVE: To examine the
prevalence of and risks for cervical HPV infection and SILs by HIV status in a
population of adolescent girls. PARTICIPANTS: Subjects recruited at each of the
16 different US sites participating in a national study of HIV infection in
adolescents. MAIN OUTCOME MEASURES: Cervical HPV DNA findings using polymerase
chain reaction detection techniques and Papanicolaou smear from baseline visits.
Infection with HPV was categorized into low- (rarely associated with cancer) and
high- (commonly associated with cancers) risk types. RESULTS: Of 133 HIV-infected
girls, 103 (77.4%) compared with 30 (54.5%) of 55 noninfected girls were positive
for HPV (relative risk [RR], 1.4; 95% confidence interval [CI], 1.1-1.8). The
risk was for high-risk (RR, 1.8; 95% CI, 1.2-2.7) but not low-risk (RR, 1.2; 95%
Cl, 0.4-3.9) HPV types. Among the girls with HPV infection, 21 (70.0%) of the non
HIV-infected girls had normal cytologic findings compared with only 29 (29.9%) of
the HIV-infected girls (P<.001). Multivariate analysis showed that HIV status was
a significant risk for HPV infection (odds ratio [OR], 3.3; 95% CI, 1.6-6.7) and
SIL (OR, 4.7; 95% CI, 1.8-14.8), but CD4 cell count and viral load were not
associated with infection or squamous intraepithelial lesions. Only 9 girls had a
CD4+ T-cell count of less than 0.2 cell X 10(9)/L. CONCLUSIONS: High prevalence
of HPV infection in both groups underscores the risky sexual behavior in this
adolescent cohort. Rates of HPV infection and SILs were higher among HIV-infected
girls, despite similar sexual risk behaviors and the relatively healthy state of
our HIV-infected group. Infection with HIV may enhance HPV proliferation through
mechanisms other than CD4 immunosuppression, particularly early in the course of
HIV infection.
PMID- 10665599
TI - Fathers and child neglect.
AB - OBJECTIVE: To examine the association between father involvement and child
neglect. DESIGN: Cohort study. SETTING: Participants were recruited from an inner
city pediatric primary care clinic and a clinic for children at risk for human
immunodeficiency virus infection in a teaching hospital. PARTICIPANTS: Mothers
and fathers or father figures, and 244 five-year olds participating in a
longitudinal study. MAIN OUTCOME MEASURES: Child neglect measured via home
observation, a videotaped mother-child interaction, and child protective services
reports. RESULTS: A father or father figure was identified for 72% of the
children. Rates of neglect ranged between 11% and 30%. Father absence alone was
not associated with neglect. However, in families with an identified and
interviewed father, a longer duration of involvement (P<.01), a greater sense of
parenting efficacy (P<.01), more involvement with household tasks (P<.05), and
less involvement with child care (P<.05) were associated with less neglect. The
overall model explained 26.5% of the variance in neglect. CONCLUSIONS: There is
substantial involvement of fathers in a subset of this high-risk sample, although
more than a quarter of the children lacked a father or father figure. The mere
presence of a father did not significantly influence the neglect of the children;
rather, the nature of his involvement did. Fathers who felt more effective as
parents were less likely to have neglected their children. A greater sense of
efficacy may reflect parenting skills and be important in enhancing the
contribution of fathers to their children's well-being. Pediatric health care
providers can play a valuable role in enhancing the involvement and skills of
fathers.
PMID- 10665600
TI - Asthma severity among children hospitalized in 1990 and 1995.
AB - BACKGROUND: During the past decade, the number of children with asthma increased;
however, the number of asthma hospitalizations for children decreased. OBJECTIVE:
To assess the proportion of high-severity cases among children hospitalized with
asthma and the association of high-severity asthma with patient and hospital
characteristics. DESIGN: The data set used was the Healthcare Cost and
Utilization Project Nationwide Inpatient Sample. Records were selected of
patients 18 years and younger who had the principal diagnosis of asthma. Records
were analyzed of 29077 patients at 746 hospitals in 1990 and 33 443 patients at
811 hospitals in 1995. Asthma severity was classified by All Patient Refined
Diagnosis-Related Groups. Cross-sectional logistic regression analysis was
performed using survey data analysis software. RESULTS: The most common diagnoses
associated with high-severity asthma were respiratory distress and respiratory
failure. The proportion of high-severity asthma cases did not change
significantly between 1990 (4.2%) and 1995 (4.6%) (P = .08). Adolescents and boys
were more likely to have high-severity asthma than children aged 5 to 12 years
and girls. Western, southern, and north-central hospitals and urban teaching
hospitals had a higher proportion of high-severity asthma cases than northeastern
hospitals and nonteaching hospitals. CONCLUSIONS: Between 1990 and 1995, the
proportion of high-severity cases among children hospitalized with asthma did not
change significantly. However, patient age, sex, region of the country, and
hospital teaching status were associated with variations in the proportion of
high-severity asthma cases.
PMID- 10665601
TI - Prevalence of symptoms of gastroesophageal reflux during childhood: a pediatric
practice-based survey. Pediatric Practice Research Group.
AB - OBJECTIVES: To determine the prevalence of symptoms associated with
gastroesophageal reflux (GER) in 3- to 17-year-old children, to describe the
prevalence of factors associated with GER in these children, and to determine the
percentage of symptomatic children who have been treated. DESIGN: A cross
sectional survey. SETTING: Sixteen pediatric practice research group practices in
the Chicago, Ill, area (urban, suburban, and semirural). PARTICIPANTS: A total of
566 parents of 3- to 9-year-old children, 584 parents of 10- to 17-year-old
children, and 615 children aged 10 to 17 years. INTERVENTION: None. MAIN OUTCOME
MEASURE: Reported frequency of symptoms associated with GER. RESULTS: Parents of
3- to 9-year-old children reported that their children experienced a sensation of
heartburn ("burning/painful feeling in middle of chest"), epigastric pain
("stomachache above belly button"), and regurgitation ("sour taste or taste of
throw up") 1.8%, 7.2%, and 2.3% of the time, respectively. Parents of 10- to 17
year-old children reported that their children experienced the same symptoms
3.5%, 3.0%, and 1.4% of the time, while children aged 10 to 17 years reported the
symptoms 5.2%, 5.0%, and 8.2% of the time, respectively. Complaints of abdominal
pain ("stomachache") were most common, reported by 23.9% and 14.7% of parents of
3- to 9-year-old and 10- to 17-year-old children and by 27.9% of children aged 10
to 17 years. In those aged 10 to 17 years, heartburn reported by the children was
associated with reported cigarette use (odds ratio, 6.5; 95% confidence interval,
2-21); no other complaint was associated with cigarette, alcohol, or caffeine
consumption or passive smoking exposure. In 3- to 9-year-old children, no
complaint was associated with caffeine consumption or passive smoking exposure.
Reported treatment in the past week with antacids was 0.5% according to parents
of children aged 3 to 9 years and 1.9% and 2.3% according to parents of children
aged 10 to 17 years and children aged 10 to 17 years, respectively. Treatment
with over-the-counter histamine receptor blockers was 0% for children aged 3 to 9
years and 10 to 17 years, as reported by their parents, and 1.3% for those aged
10 to 17 years, as reported by themselves. CONCLUSIONS: Symptoms suggestive of
GER are not rare in childhood, yet only a fraction of children with symptoms are
treated with over-the-counter antacids or histamine2 antagonists. Prospective
longitudinal data are needed to determine which children with symptoms of GER
actually have GER disease and are at risk of developing complications.
PMID- 10665602
TI - Secular trends in height among children during 2 decades: The Bogalusa Heart
Study.
AB - OBJECTIVE: To examine trends in height among 5- to 17-year-old children between
1973 and 1992. DESIGN: A panel design consisting of 7 cross-sectional surveys.
PARTICIPANTS: All schoolchildren residing in Bogalusa, La, were eligible. A total
of 24 070 examinations were performed. RESULTS: During the study period, the mean
height of schoolchildren increased by 0.70 cm per decade independently of race,
sex, and age. Trends were most pronounced among preadolescents, blacks, and boys,
with 9- to 12-year-old black boys showing a height increase of 1.8 cm per decade.
We observed a decrease in the number of relatively short children (<10th
percentile of height) and an increase in the number of tall children (>90th
percentile of height). Because a secular trend was not seen among the 15- to 17
year-old children, our findings likely reflect an acceleration of maturation.
CONCLUSIONS: It has generally been assumed that secular increases in height among
schoolchildren in the United States ceased by the mid-1900s. Our findings, which
may be due to various environmental factors, demonstrate that care must be taken
when using nonconcurrent reference data to assess the growth of children.
Additional study is needed to determine if these secular trends are continuing
and to examine possible explanations and consequences of these trends.
PMID- 10665603
TI - Adolescent patients--healthy or hurting? Missed opportunities to screen for
suicide risk in the primary care setting.
AB - CONTEXT: Adolescent suicide rates have increased dramatically in recent decades.
Suicide is the third leading cause of mortality among persons aged 10 to 19
years. Several official guidelines recommend screening for suicidal behavior in
the primary care setting. OBJECTIVES: To determine the prevalence of adolescent
suicidal behavior known to primary care providers and to determine the knowledge,
attitudes, and practice of primary care physicians in Maryland regarding
screening for risk factors for adolescent suicide. DESIGN: Cross-sectional study
using mailed survey. SETTING: Maryland from May to July 1995. PARTICIPANTS: All
pediatrician (n = 816) and family physician (n = 592) members of the state
chapter of the American Academy of Pediatrics and the American Academy of Family
Physicians, respectively, who were actively providing ambulatory care. MAIN
OUTCOME MEASURES: Adolescent suicidal behavior known to primary care providers
and predictors of routine screening for risk factors for adolescent suicide.
RESULTS: The response rate was 66%. Three hundred twenty-eight physicians (47%)
reported that 1 or more adolescent patients attempted suicide in the previous
year, but only 158 (23%) either frequently or always screened adolescent patients
for suicide risk factors. Significant factors correlating with routine screening
for suicide risk factors included frequently or always counseling about the safer
storage of firearms in the home (odds ratio [OR], 5.3; 95% confidence interval
[CI], 2.8-10.2); agreeing or strongly agreeing that they were sufficiently
trained and knew how to screen for risk factors (OR, 3.2; 95%/CI, 1.7-6.3);
agreeing or strongly agreeing that they had enough time during the well visit to
screen for mental health problems (OR, 2.9: 95% CI, 1.6-5.3); frequently or
always counseling about child passenger safety (OR, 2.7; 95% CI, 1.6-4.7);
spending more than 5 minutes in anticipatory guidance during the well visit (OR,
2.7: 95% CI, 1.5-4.6); practicing in an urban setting (OR, 2.3; 95)% CI, 1.2
4.7); agreeing or strongly agreeing that physicians can be effective in
preventing adolescent suicide and that what they do during an office visit may
help prevent adolescent suicide (OR, 2.0; 95% CI, 1.2-3.4); and female sex (OR.
1.9; 95% CI, 1.1-3.2). CONCLUSION: Despite the substantial proportion of primary
care providers who encountered suicidal adolescent patients, most providers still
do not routinely screen their patients for suicidality or associated risk
factors. More training is needed and desired by the survey respondents. Patient
confidentiality issues must be addressed. Development and widespread use of a
short, easily administered, reliable, and valid screening tool are recommended to
help busy clinicians obtain more complete information during all visits.
PMID- 10665604
TI - Acute primary Chlamydia trachomatis infection in male adolescents after their
first sexual contact.
AB - BACKGROUND: Chlamydia trachomatis infection occurs primarily among youth sexually
active persons. Few studies have evaluated the kinetics of markers of infection
in male adolescents after their first sexual contact. DESIGN: Primary C
trachomitis infection in 4 young male adolescents after their first sexual
contact was diagnosed by polymerase chain reaction and antigen detection in
sequential first voiding urine and urethral specimens, respectively. Serial serum
samples were assessed for the presence of specific IgA and IgG antibodies.
RESULTS: Both polymerase chain reaction and antigen detection correctly
identified all cases of primary C trachomatis infection. The polymerase chain
reaction method was, however, an earlier marker of infection. Three patients were
seronegative at presentation. Two of these subsequently seroconverted to either
IgA or IgG, while the third remains seronegative. The time interval from onset of
symptoms to seroconversion ranged from 10 to 25 days. CONCLUSIONS: Although
polymerase chain reaction and antigen and serologic detection have previously
been described in primary C trachomatis infection, this report documents the
variability of these markers during the first phase of infection in non-sexually
active young male adolescents. C trachomatis can be acquired by male adolescents
after their first sexual contact; however, there is a prolonged period when the
patient is seronegative, yet infections can occur.
PMID- 10665605
TI - Preventive services in a health maintenance organization: how well do
pediatricians screen and educate adolescent patients?
AB - OBJECTIVE: To determine whether pediatricians in managed care settings adhere to
national guidelines concerning the provision of clinical preventive services.
DESIGN: Surveys were mailed between September 1996 and April 1997 to all
pediatricians practicing in a California group-model health maintenance
organization. The survey asked pediatricians about their screening and education
practices on 34 recommended services and the actions taken with adolescent
patients who have engaged in risk behavior. RESULTS: The response rate was 66.2%
(N = 366). Pediatricians, on average, screened 92% of their adolescent patients
for immunization status and blood pressure; 85% for school performance; 60% to
80% for obesity, sexual intercourse, cigarette use, alcohol use, drug use, and
seat belt and helmet use; 30% to 47% for access to handguns, suicide, eating
disorders, depression, and driving after drinking alcohol; fewer than 20% for use
of smokeless tobacco, sexual orientation, sexual and physical abuse, and riding a
bike or swimming after drinking alcohol; and 26% to 41% for close friends'
engagement in risk behavior. Pediatricians' assessment and education with
adolescent patients who screened positive for risk behavior was particularly low.
Female physicians, physicians who saw a greater proportion of older adolescents,
and recent medical school graduates were more likely to provide preventive
services. CONCLUSIONS: Pediatricians in this health maintenance organization
provide preventive services to adolescent patients at rates below recommendations
but at rates greater than physicians in other practice settings. Improvement is
especially needed in the areas that contribute most to adolescent mortality and
for patients who screen positive for a risk behavior.
PMID- 10665606
TI - Child care center staff contribute to physician visits and pressure for
antibiotic prescription.
AB - OBJECTIVE: To determine whether child care center (CCC) providers contribute to
unnecessary physician referrals and antibiotic prescriptions in young children
with upper respiratory tract infections. DESIGN: A survey using a structured
telephone questionnaire between May 3, 1998, and July 27, 1998. PARTICIPANTS:
Child care center providers from randomly selected licensed Ontario CCCs
accepting diapered children. MAIN OUTCOME MEASURES: Knowledge, attitudes, and
practices concerning physician referral; exclusion; and antibiotic use for
children with upper respiratory tract infections. Indications for exclusion were
compared with published Canadian guidelines. RESULTS: Contact was made with 42
eligible CCCs to obtain the requisite number of 36 participants (participation
rate, 86%). Of the 36 centers, staff reported advising that children visit a
physician for colored nasal discharge in 28 (78%), for productive cough in 23
(64%), and for unusual behavior in 9 (25%). Also of the 36 centers, staff
reported excluding children for colored nasal discharge in 20 (56%), for
productive cough in 16 (44%), and for unusual behavior in 15 (42%). Antibiotics
were thought useful for nonspecific upper respiratory tract infections to prevent
the spread of infection in 9 (26%), to speed up recovery in 7 (21%), and to
prevent bacterial infection in 13 (38%) of 34 centers. In the previous 6 months,
25 (69%) of 36 staff members reported making an exception to exclusion because a
child had an antibiotic prescription. CONCLUSIONS: Many children are referred by
CCC staff to physicians contrary to established guidelines. As staff must act on
behalf of parents, a low threshold for referral is not unreasonable. However,
this survey confirms that CCC staff recommend children to receive antibiotics and
exclude children inappropriately. These practices are based on incomplete
knowledge. Research on appropriate management of upper respiratory tract
infections by CCC staff is needed. Education to correct specific knowledge
deficits should be initiated.
PMID- 10665607
TI - Vaccination practices, policies, and management factors associated with high
vaccination coverage levels in Georgia public clinics. Georgia Immunization
Program Evaluation Team.
AB - BACKGROUND: Controlling vaccine-preventable diseases by achieving high childhood
vaccination coverage levels is a national priority. However, there are few, if
any, comprehensive evaluations of state immunization programs in the United
States, and little attention has been given to the importance of vaccination
clinic management style and staff motivation. OBJECTIVE: To evaluate the factors
associated with the increase in childhood vaccination coverage levels from 53% in
1988 to 89% in 1994 in Georgia's public health clinics. DESIGN: A 1994 mail
survey obtaining information on clinic vaccination policies and practices and
management practices. SETTING: All 227 public health clinics in Georgia.
PARTICIPANTS: Clinic nurses responsible for vaccination services. OUTCOME
MEASURE: The 1994 clinic-specific coverage level for 21- to 23-month-old children
for 4 doses of diphtheria and tetanus toxoids and pertussis vaccine, 3 doses of
polio vaccine, and 1 dose of a measles-containing vaccine as determined by an
independent state assessment of clinic coverage levels. RESULTS: Univariate
analysis showed that higher coverage levels were significantly (P<.05) associated
with smaller clinic size, higher proportions of clientele enrolled in the Special
Supplemental Nutrition Program for Women, Infants, and Children (WIC), being a
nonurban clinic, and numerous vaccination practices and policies. Multivariable
analysis showed that only 8 of greater than 150 factors remained associated with
higher coverage levels, including having no waiting time to be seen, having
telephone reminder systems, conducting home visits for defaulters, and
restricting WIC vouchers when a child was undervaccinated. Motivational factors
related to higher coverage included clinic lead nurses receiving an incentive to
raise coverage and lead nurses participating in assessments of clinic coverage
levels by state immunization staff. CONCLUSIONS: No single factor is responsible
for raising vaccination coverage levels. Efforts to improve coverage should
include local assessment to provide feedback on performance and identify
appropriate local solutions. Coordinating with WIC, conducting recall and
reminder activities, motivating clinic staff, and having staff participate in
decisions are important in raising vaccination levels.
PMID- 10665608
TI - Underlying causes of recurrent pneumonia in children.
AB - OBJECTIVES: To determine the relative frequency of underlying factors for
recurrent pneumonia and the proportion of patients in whom the underlying illness
diagnosis was known prior to pneumonia recurrence. METHODS: Retrospective medical
record review for a 10-year period from January 1987 through December 1997 at The
Hospital for Sick Children in Toronto, Ontario, a tertiary care pediatric
hospital. Recurrent pneumonia was defined as at least 2 pneumonia episodes in a 1
year period or at least 3 during a lifetime. RESULTS: Of 2952 children
hospitalized with pneumonia, 238 (8%) met criteria for recurrent pneumonia. An
underlying illness diagnosis was identified in 220 (92%). Of these, the
underlying illness was diagnosed prior to pneumonia in 178 (81%), with the first
episode in 25 (11%), and during recurrence in 17 (8%). Underlying illnesses
included oropharyngeal incoordination with aspiration syndrome (114 cases [48%]),
immune disorder (24 [10%]), congenital cardiac defects (22 [9%]), asthma (19
[8%]), pulmonary anomalies (18 [8%]), gastroesophageal reflux (13[5%]), and
sickle cell anemia (10 [4%]). Clinical clues to diagnosis were recurrent
infections at other locations and failure to thrive in the cases of an immune
disorder, recurrences involving the same location in those with underlying
pulmonary pathology, the association of respiratory symptoms with feeding in
those with gastroesophageal reflux, or recurrent wheezing in asthmatic children.
CONCLUSIONS: Recurrent pneumonia occurs in fewer than one tenth of all children
hospitalized with pneumonia. Most of them have a known predisposing factor. The
most common cause was oropharyngeal incoordination.
PMID- 10665609
TI - Compliance with prescription filling in the pediatric emergency department.
AB - OBJECTIVES: To determine the rate of compliance with filling of prescriptions
written in a pediatric emergency department and to examine the reasons for not
filling the prescriptions. DESIGN: Compliance with filling prescriptions was
determined using a follow-up standardized telephone questionnaire, designed so
that it was not obvious that assessing prescription filling was the major reason
for the study. Compliance herein was defined as having the prescription filled on
the same or next day of the pediatric emergency department visit. SETTING:
Pediatric emergency department of a tertiary care hospital. SUBJECTS: Pediatric
patients discharged home with a drug prescription. MAIN OUTCOME MEASURE: The
proportion of prescriptions written in the pediatric emergency department that
were filled on either the same or next day as determined by telephone follow-up.
This outcome is expressed as a proportion with 95% confidence interval. RESULTS:
Follow-up was completed in 1014 (83%) of the 1222 children, aged 4.5 +/- 4.2
(mean +/- SD) years. Compliance with prescription filling was 92.7% (940/1014).
Parental reasons for not filling the prescription included medication unnecessary
(27%), financial (6.8%), and not enough time (6.8%). Dissatisfaction with the
explanation of the medical problem, instructions for treatment, and instructions
for follow-up treatment were significantly associated with noncompliance by
univariable logistic regression (P<.05). CONCLUSION: The rate of prescription
nonfilling in children seen in a pediatric emergency department is at least 7%,
although lower than that in adults in a similar setting.
PMID- 10665610
TI - Radiological case of the month. Focal nodular hyperplasia of the liver.
PMID- 10665611
TI - Picture of the month. Phytophotodermatitis.
PMID- 10665612
TI - Pathological case of the month. Solitary intestinal fibromatosis.
PMID- 10665613
TI - Choice of antibiotics in febrile neonates.
PMID- 10665614
TI - Reduced prefrontal gray matter volume and reduced autonomic activity in
antisocial personality disorder.
AB - BACKGROUND: Major damage to gray and white matter in the prefrontal cortex and
autonomic deficits have been found to result in pseudopsychopathic personality in
patients with neurological disorders, but it is not known whether people with
antisocial personality disorder (APD) in the community who do not have
discernable brain trauma also have subtle prefrontal deficits. METHODS:
Prefrontal gray and white matter volumes were assessed using structural magnetic
resonance imaging in 21 community volunteers with APD (APD group) and in 2
control groups, comprising 34 healthy subjects (control group), 26 subjects with
substance dependence (substance-dependent group), and 21 psychiatric controls.
Autonomic activity (skin conductance and heart rate) was also assessed during a
social stressor in which participants gave a videotaped speech on their faults.
RESULTS: The APD group showed an 11.0% reduction in prefrontal gray matter volume
in the absence of ostensible brain lesions and reduced autonomic activity during
the stressor. These deficits predicted group membership independent of
psychosocial risk factors. CONCLUSIONS: To our knowledge, these findings provide
the first evidence for a structural brain deficit in APD. This prefrontal
structural deficit may underlie the low arousal, poor fear conditioning, lack of
conscience, and decision-making deficits that have been found to characterize
antisocial, psychopathic behavior.
PMID- 10665615
TI - Effects of supraphysiologic doses of testosterone on mood and aggression in
normal men: a randomized controlled trial.
AB - BACKGROUND: Field studies of illicit anabolic-androgenic steroid users suggest
that some develop manic or aggressive reactions to these drugs-a potential public
health problem. However, controlled laboratory evaluations of these effects
remain limited. METHODS: In a randomized, placebo-controlled, crossover trial, we
administered testosterone cypionate for 6 weeks in doses rising to 600 mg/wk and
placebo for 6 weeks, separated by 6 weeks of no treatment, to 56 men aged 20 to
50 years. Psychiatric outcome measures included the Young Mania Rating Scale
(YMRS), the Point Subtraction Aggression Paradigm (a computerized provocation
test of aggression), the Aggression Questionnaire of Buss and Perry, the Symptom
Checklist-90-R, daily diaries of manic and depressive symptoms, and similar
weekly diaries completed by a "significant other" who knew the participant well.
RESULTS: Testosterone treatment significantly increased manic scores on the YMRS
(P = .002), manic scores on daily diaries (P = .003), visual analog ratings of
liking the drug effect (P = .008), and aggressive responses on the Point
Subtraction Aggression Paradigm (P = .03). Drug response was highly variable: of
50 participants who received 600 mg/wk of testosterone cypionate, 42 (84%)
exhibited minimal psychiatric effects (maximum YMRS score, <10), 6 (12%) became
mildly hypomanic (YMRS score, 10-19), and 2 (4%) became markedly hypomanic (YMRS
score, > or =20). The 8 "responders" and 42 "nonresponders" did not differ
significantly on baseline demographic, psychological, laboratory, or
physiological measures. CONCLUSIONS: Testosterone administration, 600 mg/wk
increased ratings of manic symptoms in normal men. This effect, however, was not
uniform across individuals; most showed little psychological change, whereas a
few developed prominent effects. The mechanism of these variable reactions
remains unclear.
PMID- 10665616
TI - A double-blind, placebo-controlled trial of testosterone therapy for HIV-positive
men with hypogonadal symptoms.
AB - BACKGROUND: The goal was to evaluate the efficacy of testosterone in alleviation
of hypogonadal symptoms (diminished libido, depressed mood, low energy, and
depleted muscle mass) in men with symptomatic human immunodeficiency virus
illness. METHODS: Seventy-four patients were enrolled in a double-blind, placebo
controlled 6-week trial with bi-weekly testosterone injections, followed by 12
weeks of open-label maintenance treatment. Major outcome measures were Clinical
Global Impressions Scale ratings for libido, mood, energy, and erectile function;
Hamilton Depression Rating Scale scores, and Chalder Fatigue Scale scores. Body
composition changes were assessed with bioelectric impedance analysis. RESULTS:
Seventy men completed the 6-week trial. Response rates, defined as much or very
much improved libido, were 74% (28/38) for patients randomized to testosterone,
and 19% (6/32) for placebo-treated patients (P<.001). Of the 62 completers with
fatigue at baseline, 59% (20/34) receiving testosterone and 25% (7/28) receiving
placebo reported improved energy (P<.01). Among the 26 completers with an Axis I
depressive disorder at baseline, 58% of the testosterone-treated patients
reported improved mood compared with 14% of placebo-treated patients (Fisher
exact test = .08). With testosterone treatment, average increase in muscle mass
over 12 weeks was 1.6 kg for the whole group, and 2.2 kg for the 14 men with
wasting at baseline. Improvement on all parameters was maintained during
subsequent open-label treatment for up to 18 weeks. CONCLUSION: Testosterone is
well tolerated and effective in the short-term treatment of symptoms of clinical
hypogonadism in men with symptomatic human immunodeficiency virus illness,
restoring libido and energy, alleviating depressed mood, and increasing muscle
mass.
PMID- 10665617
TI - Time course of effects of testosterone administration on sexual arousal in women.
AB - BACKGROUND: The assumption that testosterone is involved in human female sexual
functioning is mainly based on results of studies of women with hypogonadotropic
hypogonadism. This study sought to determine the effect of testosterone
administration on physiological and subjective sexual arousal in sexually
functional women. METHODS: In a double-masked, randomly assigned, placebo
controlled crossover design, we examined whether administration of a single dose
of testosterone to sexually functional women increases vaginal and subjective
sexual arousal when they are exposed to erotic visual stimuli. To search for a
time lag in the effect of testosterone therapy, we exposed 8 healthy women to 6
erotic film excerpts depicting intercourse. The first and second excerpts were
shown immediately before and 15 minutes after, respectively, intake of placebo or
testosterone; the last 4 excerpts were then shown at 1(1/2)-hour intervals.
RESULTS: Sublingual intake of testosterone caused a sharp increase in plasma
testosterone levels within 15 minutes; these levels declined to baseline values
within 90 minutes. Three to 4(1/2) hours after reaching peak testosterone level,
we found a statistically significantly increase in genital responsiveness (P =
.04). Furthermore, on the day of testosterone treatment, there also was a strong
and statistically significant association between the increase in genital arousal
and subjective reports of "genital sensations" (P = .02) and "sexual lust" (P =
.01) after 4(1/2) hours. CONCLUSIONS: There is a time lag in the effect of
sublingually administered testosterone on genital arousal in women. In addition,
a consecutive increase in vaginal arousal might cause higher genital sensations
and sexual lust.
PMID- 10665618
TI - Extended-release physostigmine in Alzheimer disease: a multicenter, double-blind,
12-week study with dose enrichment. Physostigmine Study Group.
AB - BACKGROUND: The efficacy of extended-release physostigmine salicylate, an
acetylcholinesterase inhibitor, was evaluated in 850 subjects with mild-to
moderate Alzheimer disease (AD) in a multicenter trial. METHODS: Subjects
initially entered a dose-enrichment phase in which they received 1 week each of
physostigmine salicylate, 24 mg/d and 30 mg/d, and daily placebo. Among the
subjects who completed this phase, 35.9% responded to physostigmine treatment,
whereas 62.4% were considered nonresponders, and 1.6% could not be evaluated
because of missing data. After a 4-week placebo-washout phase, 176 responder
subjects were randomized to receive their best dose of physostigmine or placebo
in a 12-week double-blind phase. Primary efficacy measures included the cognitive
subscale of the Alzheimer's Disease Assessment Scale (ADAS-Cog), the Clinician's
Interview-Based Impression of Change With Caregiver Input (CIBIC+), and the
Clinical Global Impression of Change (CGIC). RESULTS: In the intent-to-treat
analysis of the double-blind phase, physostigmine-treated subjects scored -2.02
points better than placebo-treated subjects on the ADAS-Cog (F1,167 = 6.42 [P =
.01]) and 0.33 points higher on the CIBIC+ (F1,150 = 5.68 [P = .02]). No
significant improvement was observed on the CGIC or the secondary outcome
measures. Nausea and vomiting were experienced by 47.0% of all physostigmine
treated subjects during the double-blind phase. CONCLUSIONS: Physostigmine
demonstrated a statistically significant benefit compared with placebo on a
clinical global rating of change and an objective test of cognitive function.
Given the frequency of gastrointestinal side effects, the role of this agent in
clinical use remains to be determined.
PMID- 10665619
TI - A randomized controlled trial of cognitive-behavioral therapy for persistent
symptoms in schizophrenia resistant to medication.
AB - BACKGROUND: Research evidence supports the efficacy of cognitive-behavioral
therapy in the treatment of drug-refractory positive symptoms of schizophrenia.
Although the cumulative evidence is strong, early controlled trials showed
methodological limitations. METHODS: A randomized controlled design was used to
compare the efficacy of manualized cognitive-behavioral therapy developed
particularly for schizophrenia with that of a nonspecific befriending control
intervention. Both interventions were delivered by 2 experienced nurses who
received regular supervision. Patients were assessed by blind raters at baseline,
after treatment (lasting up to 9 months), and at a 9-month follow-up evaluation.
Patients continued to receive routine care throughout the study. An assessor
blind to the patients' treatment groups rated the technical quality of audiotaped
sessions chosen at random. Analysis was by intention to treat. RESULTS: Ninety
patients received a mean of 19 individual treatment sessions over 9 months, with
no significant between-group differences in treatment duration. Both
interventions resulted in significant reductions in positive and negative
symptoms and depression. At the 9-month follow-up evaluation, patients who had
received cognitive therapy continued to improve, while those in the befriending
group did not. These results were not attributable to changes in prescribed
medication. CONCLUSION: Cognitive-behavioral therapy is effective in treating
negative as well as positive symptoms in schizophrenia resistant to standard
antipsychotic drugs, with its efficacy sustained over 9 months of follow-up.
PMID- 10665620
TI - Brain serotonin1A receptor binding measured by positron emission tomography with
[11C]WAY-100635: effects of depression and antidepressant treatment.
AB - BACKGROUND: Pharmacological and postmortem investigations suggest that patients
with major depressive disorder have alterations in function or density of brain
serotonin1A (5-HT1A) receptors. The aim of the present study was to use positron
emission tomography with the selective 5-HT1A receptor antagonist [11C]WAY-100635
to measure 5-HT1A receptor binding in depressed patients before and during
treatment with selective serotonin reuptake inhibitors. METHODS: Positron
emission tomographic scans with [11C]WAY-100635 were performed on 25 patients
with major depressive disorder. These included 15 unmedicated depressed patients.
Ten of these unmedicated patients were scanned again during selective serotonin
reuptake inhibitor treatment. A further 10 patients with major depressive
disorder were scanned on one occasion only while taking selective serotonin
reuptake inhibitors. Comparisons were made with [11C]WAY-100635 positron emission
tomographic scans in 18 healthy volunteer subjects. Region of interest analysis
and statistical parametric mapping were performed on binding potential images
generated using a reference tissue model. RESULTS: Binding potential values were
reduced across many of the regions examined, including frontal, temporal, and
limbic cortex in both unmedicated and medicated depressed patients compared with
healthy volunteers. Binding potential values in medicated patients were similar
to those in unmedicated patients. CONCLUSIONS: Major depressive disorder is
associated with a widespread reduction in 5-HT1A receptor binding. This reduced 5
HT1A receptor binding was not changed by selective serotonin reuptake inhibitor
treatment.
PMID- 10665621
TI - Neurologic soft signs in chronic posttraumatic stress disorder.
AB - BACKGROUND: Subtle neurologic impairment has been reported in several mental
disorders. The goals of the present study were to evaluate neurologic status in
patients of both sexes with chronic posttraumatic stress disorder (PTSD) from
different traumatic experiences. METHODS: Twenty-one adult women who were
sexually abused as children (12 with PTSD, 9 without) and 38 male Vietnam War
combat veterans (23 with PTSD, 15 without) underwent examination for 41
neurologic soft signs, which were scored by the examiner as well as a blind rater
observing videotapes. Subject history was obtained with special attention to
neurodevelopmental problems. Psychometrics included the Wender Utah Rating Scale
for symptoms of childhood attention-deficit/hyperactivity disorder and the
Michigan Alcoholism Screening Test. Veterans also completed the Combat Exposure
Scale and subtests of the Wechsler Adult Intelligence Scale-Revised. RESULTS:
Average neurologic soft sign scores (interrater reliability = 0.74) of women with
PTSD owing to sexual abuse in childhood (mean [SD], 0.77 [0.32]) and veteran men
(0.72 [0.20]) with combat-related PTSD were comparable and significantly (P<.001)
higher than those of women sexually abused as children (0.42 [0.10]) and combat
veteran men (0.43 [0.17]) without PTSD. This effect could not be explained by a
history of alcoholism or head injury. Subjects with PTSD reported more
neurodevelopmental problems and more childhood attention-deficit/hyperactivity
disorder symptoms and had lower IQs, all of which were significantly correlated
with neurologic soft signs. CONCLUSION: Neurologic compromise is evident from
subject history and findings from physical examination in both women and men with
chronic PTSD who had experienced different kinds of traumatic events in childhood
and adulthood.
PMID- 10665622
TI - Does lithium treatment still work? Evidence of stable responses over three
decades.
AB - To evaluate whether lithium treatment has been overvalued and may be no longer as
effective as formerly, we reviewed published reports on long-term lithium
treatment (1970-1996) as well as analyzing its clinical effects on 360 patients
with DSM-IV bipolar disorder who entered into lithium maintenance monotherapy
after 1970. Neither reported recurrence rates nor average proportions of time ill
nor patient improvement of 50% or more during lithium maintenance therapy in a
stable clinic setting has changed significantly since the 1970s. Unfavorable
results in some settings may reflect accumulation over time of patients with
complex, less treatment-responsive illnesses. Lithium is unmatched in research
support for long-term clinical effectiveness against morbidity and mortality
associated with depression or mania in bipolar I and II disorders. Data evaluated
herein did not support suggestions that benefits of lithium have been exaggerated
in the past or have been lost recently.
PMID- 10665623
TI - Discrepancies in the efficacy of lithium.
PMID- 10665624
TI - Social phobia or social anxiety disorder: what's in a name?
PMID- 10665625
TI - Molecular neurobiology for practicing psychiatrists, part 4: transferring the
message of chemical neurotransmission from presynaptic neurotransmitter to
postsynaptic gene expression.
AB - Neurotransmitters activate genes in their target neurons by precipitating a
molecular cascade, which may be the ultimate consequence of chemical
neurotransmission. When this transfer is aberrant, a mental disorder may be
manifest. When drugs act upon neurons to change gene expression, this could lead
to therapeutic actions, side effects, and the long-term consequences of drug
abuse.
PMID- 10665626
TI - Safety and tolerability of oral loading divalproex sodium in acutely manic
bipolar patients.
AB - BACKGROUND: Achieving therapeutic blood levels of a mood stabilizer as quickly as
possible is desirable in patients with acute mania. We examined the feasibility
and safety of an accelerated oral loading strategy (divalproex, 30 mg/kg/day, on
days 1 and 2, followed by 20 mg/kg/day on days 3-10) designed to bring serum
valproate concentrations to therapeutic levels (i.e., above 50 microg/mL).
METHOD: Fifty-nine patients who met DSM-IV diagnostic criteria for current manic
episode and who had a Mania Rating Scale score > or = 14 were randomly assigned
on a double-blind basis to receive divalproex oral loading (N = 20); divalproex
nonloading (N = 20) at a starting dose of 250 mg t.i.d. on days 1 and 2, followed
by standard dose titration for days 3 to 10; or lithium carbonate (N = 19) at a
starting dose of 300 mg t.i.d., followed by standard dose titration for days 3 to
10. RESULTS: Eighty-four percent of the divalproex-loading patients, but only 30%
of the divalproex-nonloading patients, had valproate serum levels above 50
microg/mL at day 3 of the study. None of the lithium-treated patients had serum
lithium levels above 0.8 mEq/L at study day 3. No patient was removed from the
study because of an adverse event. There were no significant differences between
the groups in the frequencies or types of adverse events. CONCLUSION: Accelerated
oral loading with divalproex sodium is a feasible and safe method to bring serum
valproate concentrations to effective levels rapidly.
PMID- 10665627
TI - The emergence of social phobia during clozapine treatment and its response to
fluoxetine augmentation.
AB - BACKGROUND: The underlying neurochemical basis of social phobia has yet to be
fully explained, but there are suggestions of serotonergic and dopaminergic
dysfunction. The atypical neuroleptic clozapine has been reported to induce
anxiety symptoms, probably owing to its effect on serotonergic pathways. We
report 12 cases of schizophrenic patients who developed social phobia during
clozapine treatment. METHOD: Patients were assessed using the Structured Clinical
Interview for DSM-III-R, Patient Version, Scale for the Assessment of Negative
Symptoms, Scale for the Assessment of Positive Symptoms, the Liebowitz Social
Phobia Scale, and the Brief Psychiatric Rating Scale. They were reevaluated after
12 weeks of cotreatment with clozapine and fluoxetine. RESULTS: In 8 of the 12
cases, symptoms responded (> or = 35% reduction in Liebowitz Social Phobia Scale
score) with an adjunctive regimen of fluoxetine. CONCLUSION: Data are discussed
in light of neurochemical mechanisms and cognitive adaptations that could explain
the onset of anxiety spectrum disorders (such as social phobia) in clozapine
treated schizophrenic subjects during remission of psychotic symptoms.
PMID- 10665628
TI - Multicenter, placebo-controlled, fixed-dose study of citalopram in moderate-to
severe depression.
AB - BACKGROUND: Citalopram, the most selective serotonin reuptake inhibitor (SSRI),
is a bicyclic phthalane derivative with a chemical structure that is unrelated to
that of other SSRIs and available antidepressants. The drug is approved for use
in 69 countries. This 6-week, fixed-dose, placebo-controlled, parallel-arm,
multicenter trial was performed to confirm its efficacy and safety in treatment
of outpatients with major depression in the United States. METHOD: Six hundred
and fifty adult outpatients with moderate-to-severe major depression (DSM-III-R)
were randomly assigned to receive citalopram at doses of 10 mg (N = 131), 20 mg
(N = 130), 40 mg (N = 131), or 60 mg (N = 129) or placebo (N = 129) once daily.
Outcome assessments were the 21-item Hamilton Rating Scale for Depression (HAM
D), the Montgomery-Asberg Depression Rating Scale (MADRS), and the Clinical
Global Impressions scale. RESULTS: Between-group comparisons of the change from
baseline to endpoint revealed significantly greater improvement in the citalopram
patients relative to the placebo patients on all 3 efficacy measures. Patients
randomly assigned to 40 mg/day and 60 mg/day of citalopram showed significantly
greater improvement than placebo on all efficacy measures, as well as on the HAM
D symptom clusters measuring depressed mood, melancholia, cognitive disturbance,
and psychomotor retardation. Patients who received 10 mg/day and 20 mg/day of
citalopram also showed consistent improvement relative to placebo on all efficacy
ratings, with statistical significance demonstrated in the MADRS response rate,
the HAM-D depressed mood item, and the HAM-D melancholia subscale. Citalopram was
well tolerated, with only 15% of patients discontinuing for adverse events. The
side effects most commonly associated with citalopram treatment were nausea, dry
mouth, somnolence, insomnia, and increased sweating. CONCLUSION: Citalopram was
significantly more effective than placebo in the treatment of moderate-to-severe
major depression, especially symptoms of depressed mood and melancholia, with
particularly robust effects shown at doses of 40 and 60 mg/day. Citalopram was
well tolerated in spite of forced upward titration to fixed-dose levels, with a
low incidence of anxiety, agitation, and nervousness.
PMID- 10665629
TI - Paroxetine, clomipramine, and cognitive therapy in the treatment of panic
disorder.
AB - BACKGROUND: This 12-week, placebo-controlled study was carried out to compare the
relative efficacy of paroxetine, clomipramine, and cognitive therapy in the
treatment of DSM-III-R-defined panic disorder with or without agoraphobia.
METHOD: After a 3-week single-blind, placebo run-in period, 131 patients were
randomly assigned to receive double-blind medication or 12 sessions of cognitive
therapy based on the model of Clark. Efficacy assessments included the daily
panic attack diary, the Clinical Global Impression scale, the Patient Global
Evaluation, the Hamilton Rating Scale for Anxiety, the Marks-Sheehan Phobia
Scale, the Montgomery-Asberg Depression Rating Scale, and the Sheehan Disability
Scale. RESULTS: Comparisons with placebo revealed significant superiority of
paroxetine (20-60 mg/day) and clomipramine (50-150 mg/day) on nearly all outcome
measures. On most measures, paroxetine also showed higher efficacy than cognitive
therapy. With few exceptions, cognitive therapy did not differ significantly from
placebo. The number of subjects becoming panic-free (66%) was higher and the
onset of action was faster in the paroxetine-treated group. Treatment with
cognitive therapy yielded the highest drop-out rate (26%). CONCLUSION: In this
short-term study assessing treatment of panic disorder and agoraphobia,
paroxetine and clomipramine were consistently superior to pill placebo, whereas
cognitive therapy was superior on only a few measures.
PMID- 10665630
TI - Clinical features, psychiatric comorbidity, and health-related quality of life in
persons reporting compulsive computer use behavior.
AB - BACKGROUND: We sought to examine the demographic and clinical features and
psychiatric comorbidity in persons reporting compulsive computer use. METHOD:
Sixteen men and 5 women were recruited by advertisement and word-of-mouth. All
reported excessive computer use that interfered with social or occupational
functioning or caused personal distress. The subjects completed structured and
semistructured assessments, including a computer version of the Diagnostic
Interview Schedule (DIS), the Minnesota Impulsive Disorders Interview, the
Personality Diagnostic Questionnaire-Revised (PDQ-R), and a brief version of the
Medical Outcome Study Short Form-36 (SF-36). RESULTS: The typical subject was a
32-year-old single white man with a mean yearly income of $27,000; problem
computer use began at age 29 and consumed 27 hours each week. Eleven subjects
(52%) reported school or academic problems resulting from their computer use, and
12 (57%) reported that family members had confronted them about it. Thirteen
subjects (62%) had tried to cut back on their computer usage. Nine subjects (43%)
reported missing work or school owing to their computer use. According to DIS
results, 7 subjects (33%) had a lifetime mood disorder, 8 subjects (38%) had a
substance use disorder, and 4 subjects (19%) had a lifetime anxiety disorder.
According to the PDQ-R results, 11 subjects (52%) met criteria for at least one
personality disorder, the most frequent being the borderline, antisocial, and
narcissistic types. Impulse-control disorders were also common, particularly
compulsive buying. On the SF-36, subjects showed impaired mental health
functioning compared with a normative sample. CONCLUSION: The results show that
persons reporting compulsive computer use suffer substantial psychiatric
comorbidity and show evidence of emotional distress. While the disorder appears
to be increasing in prevalence, more work is needed to determine its relationship
with other disorders and to determine its risk factors, family history,
psychosocial complications, and natural history.
PMID- 10665631
TI - Venlafaxine in the treatment of dysthymia: an open-label study.
AB - BACKGROUND: Numerous studies have demonstrated the effectiveness of
antidepressant medications in the treatment of dysthymia, or chronic mild
depression. Venlafaxine blocks reuptake of both serotonin and norepinephrine and
may produce a more complete antidepressant response than do single-mechanism
selective serotonin reuptake inhibitors. The purpose of this open-label study was
to provide preliminary data on the tolerability and effectiveness of venlafaxine
for patients with dysthymia. METHOD: Twenty-two dysthymic subjects (DSM-III-R
criteria) were enrolled in this 10-week, open-label trial, and 5 dropped out
prior to their second visit. Seventeen subjects (77.3%) received more than 1 week
of medication. RESULTS: Of these 17 subjects, 13 (76.5%) were treatment
responders. Results of paired sample t tests were highly significant, indicating
that, on average, there was significant improvement on all measures of
symptomatology and functioning, with mean +/- SD scores on the Hamilton Rating
Scale for Depression decreasing from 20.95 +/- 6.50 at baseline to 6.06 +/- 5.49
at week 10. The mean +/- SD final dose was 178.68 +/- 70.80 mg/day. Side effects
were reported by 17 (85%) of the 20 subjects for whom tolerability was assessed
(the most common were fatigue, dry mouth, and nausea); 5 (22.7%) of 22 patients
discontinued treatment because of side effects, primarily nausea (N = 3).
CONCLUSION: These findings suggest the benefit of venlafaxine in the treatment of
chronic depression and the need for more rigorous studies.
PMID- 10665632
TI - Effectiveness of antipsychotic therapy in a naturalistic setting: a comparison
between risperidone, perphenazine, and haloperidol.
AB - BACKGROUND: Therapeutic ineffectiveness and noncompliance with antipsychotic
agents are major contributors to rehospitalization in patients with psychotic
disorders. It is unknown whether risperidone's favorable side effect profile
compared with that of the conventional antipsychotics results in improved
compliance and reduced hospitalizations in a naturalistic setting. The purpose of
this study was to test the hypothesis that treatment with risperidone reduces
readmission rates and associated costs when compared with treatment with
perphenazine or haloperidol. METHOD: Inpatients prescribed either risperidone,
perphenazine, or haloperidol between January 1, 1995, and December 31, 1995, as a
single oral antipsychotic at discharge were retrospectively identified. Data were
collected for that index hospitalization and for a 1-year follow-up period.
Primary outcome measures included re-admission rates, changes in antipsychotic
therapy, anticholinergic drug use, and costs. RESULTS: There were 202 evaluable
patients (81 treated with risperidone, 78 with perphenazine, and 43 with
haloperidol). Baseline demographics were similar between groups except that more
patients in the risperidone group had a primary diagnosis of psychotic disorder
or had been hospitalized in the year prior to study. The percentage of patients
readmitted during the 1-year follow-up period was similar among drug groups (41%
risperidone, 26% perphenazine, and 35% haloperidol) when controlled for baseline
differences in diagnosis and hospitalization history (p = .32). Anticholinergic
drug use was more common in the haloperidol group (p = .004). Mean yearly cost
(drug + hospitalization) in the risperidone group was $20,317, nearly double that
in the other treatment groups (p < .001). CONCLUSION: The results from this
naturalistic study indicate that the high cost of risperidone is not offset by a
reduction in readmission rates when compared with conventional antipsychotics.
PMID- 10665633
TI - Buspirone as an antidote to SSRI-induced bruxism in 4 cases.
AB - BACKGROUND: One hypothesis to explain selective serotonin reuptake inhibitor
(SSRI)-induced bruxism states that SSRIs increase extrapyramidal serotonin
levels, thereby inhibiting dopaminergic pathways controlling movement. Previous
reports have emphasized buspirone's postsynaptic dopaminergic effect as a partial
antidote to the suppressed dopamine levels. CASE REPORTS: Four patients, recently
started on treatment with the SSRI sertraline, presented with new-onset
complaints attributable to SSRI-induced bruxism. All 4 responded to adjunctive
buspirone, a serotonin-1A (5-HT1A) receptor agonist, with relief of bruxism and
associated symptoms. DISCUSSION: We expand the hypothesis put forth in previous
reports by proposing that buspirone is not only acting postsynaptically in the
extrapyramidal system, but also presynaptically on serotonergic neurons that
influence masticatory modulation in the mesocortical tract. Our 4 cases support
the concept of buspirone acting as a full agonist at the presynaptic 5-HT1A
somatodendritic receptors located on the cell bodies of raphe serotonergic
neurons that project to the ventral tegmental area (VTA) of the midbrain. These
serotonergic neurons modulate the firing of the mesocortical tract, which itself
projects from the VTA to the prefrontal cortex and acts on masticatory muscle
activity through inhibiting spontaneous movements such as bruxism. While the
literature is confusing and contradictory on definitions of bruxism and
etiologies of incompletely understood movement disorders, we believe SSRI-induced
bruxism is best conceptualized as a form of akathisia.
PMID- 10665634
TI - Two-year maintenance treatment with citalopram, 20 mg, in unipolar subjects with
high recurrence rate.
AB - BACKGROUND: The efficacy of citalopram, 20 to 60 mg/day, in relapse prevention in
major depression was demonstrated in 6-month placebo-controlled studies. The
authors tested the efficacy of citalopram, 40 mg/day, in relapse prevention over
a 4-month period and citalopram, 20 mg/day, in recurrence prevention over a 24
month period. METHOD: Fifty inpatients with recurrent major depressive disorder
(DSM-IV criteria) who had had at least one depressive episode during the 18
months preceding the index episode were openly treated with citalopram, 40
mg/day. Thirty-six subjects had a stable response to citalopram and remained in
the continuation treatment with citalopram, 40 mg/day, for 4 months as
outpatients. At the time of recovery, 32 patients gave their written informed
consent before entering the 24-month maintenance period with citalopram, 20
mg/day. They were evaluated monthly by trained psychiatrists on the basis of the
21-item Hamilton Rating Scale for Depression. Every 3 months, patients were given
the Sheehan Disability Scale, a self-rating instrument, to assess their
psychosocial adjustment. RESULTS: No relapse was observed in the 4-month
continuation period. Sixteen (50%) of 32 patients who entered the 24-month
maintenance period had a new recurrence. Patients with recurrence showed a
persistent moderate disability on Sheehan Disability Scale score, while no
further differences were highlighted in clinical and demographic characteristics
between patients with and without recurrence. CONCLUSION: In agreement with
previous findings, these data suggest that a full dose of antidepressant is
strongly recommended in prophylactic therapy of patients with recurrent major
depression. Moreover, it appears that psychosocial impairment may increase the
risk of recurrence, thus conditioning a poor outcome.
PMID- 10665635
TI - Sildenafil treatment of antidepressant-induced sexual dysfunction.
PMID- 10665636
TI - Improved outcome in fluvoxamine-treated patients with SSRI-induced sexual
dysfunction.
PMID- 10665637
TI - Choreiform dyskinesia with acute onset and protracted course following fluoxetine
treatment.
PMID- 10665638
TI - Deliberate self-poisoning following fluvoxamine-neuroleptics combination.
PMID- 10665639
TI - Penile anesthesia associated with sertraline use.
PMID- 10665640
TI - Tardive dyskinesia associated with olanzapine monotherapy.
PMID- 10665641
TI - Schizoaffective disorder: a form of schizophrenia or affective disorder?
AB - BACKGROUND: The diagnostic status of schizoaffective disorder continues to be
controversial. Researchers have proposed that schizoaffective disorder represents
a variant of schizophrenia or affective disorder, a combination of the 2, or an
intermediate condition along a continuum between schizophrenia and affective
disorder. METHOD: We compared outpatients aged 45 to 77 years with DSM-III-R
diagnosis of schizoaffective disorder (N = 29), schizophrenia (N = 154), or
nonpsychotic mood disorder (N = 27) on standardized rating scales of
psychopathology and a comprehensive neuropsychological test battery. A
discriminant function analysis was used to classify the schizoaffective patients
based on their neuropsychological profiles as being similar either to
schizophrenia patients or to those with nonpsychotic mood disorder. RESULTS: The
schizoaffective and schizophrenia patients had more severe dyskinesia, had a
weaker family history of mood disorder, had been hospitalized for psychiatric
reasons more frequently, were more likely to be prescribed neuroleptic and
anticholinergic medication, and had somewhat less severe depressive symptoms than
the mood disorder patients. The schizophrenia patients had more severe positive
symptoms than the schizoaffective and mood disorder patients. The
neuropsychological performances of the 2 psychosis groups were more impaired than
those of the nonpsychotic mood disorder patients. Finally, on the basis of a
discriminant function analysis, the schizoaffective patients were more likely to
be classified as having schizophrenia than a mood disorder. CONCLUSION: These
findings suggest that schizoaffective disorder may represent a variant of
schizophrenia in clinical symptom profiles and cognitive impairment.
PMID- 10665642
TI - Beta-catenin accumulation and mutation of exon 3 of the beta-catenin gene in
hepatocellular carcinoma.
PMID- 10665643
TI - Reduced T cell response in carcinogen-sensitive Donryu rats compared with
carcinogen-resistant DRH rats.
AB - Carcinogen-resistant DRH rats were developed from carcinogen-sensitive Donryu
rats, which showed a high incidence of hepatic tumors when they were exposed to
3'-methyl-4-dimethyl-amino-azobenzene (3'-MeDAB4) or other aminoazo
hepatocarcinogens. In order to study the mechanism of the difference of
carcinogenesis, we studied the immunological competence of Donryu rats compared
with that of DRH rats. Anti-keyhole limpet hemocyanin (KLH) antibody and KLH
specific delayed hypersensitivity (DTH) responses after immunization with KLH
were reduced in Donryu rats compared with DRH rats. Proliferative responses of
spleen cells to KLH and nonspecific mitogens such as conconavalin A (Con A) and
phytohemagglutinin (PHA) were significantly lower in Donryu rats than in DRH
rats. Upon the cross-linking of T cell receptor (TCR) complex using anti-CD3
monoclonal antibody (Mab), spleen cells from Donryu rats proliferated poorly. Two
other strains of rats, SD and Wistar, exhibited high responsiveness, comparable
to that of DRH rats, indicating that the responsiveness of Donryu rats was
impaired. The production of interleukin-2 (IL-2) upon stimulation with Con A and
the responsiveness of Con A blasts to exogenous IL-2 were also attenuated in
Donryu rats. In contrast to T cell responsiveness, natural killer (NK) cell
activity of spleen was increased in Donryu rats. Flow cytometric analysis
revealed that the expression of CD4 and CD8 on T cells was decreased in Donryu
rats, though the expression of other T cell markers such as CD2, CD3 and CD5 was
not different. These results indicate that Donryu rats, which have been used in
many years for cancer research in Japan, have impaired immunological surveillance
mechanisms. This is likely to be one of the factors accounting for the high
sensitivity to chemical carcinogens and the high susceptibility to transplanted
tumor cells of Donryu rats.
PMID- 10665644
TI - Epstein-Barr virus-encoded latent membrane protein 1 co-expresses with epidermal
growth factor receptor in nasopharyngeal carcinoma.
AB - Latent membrane protein 1 (LMP-1) is the only Epstein-Barr virus (EBV)-encoded
oncogenic protein that has been detected in nasopharyngeal carcinoma (NPC), a
cancer that is closely associated with EBV. Previous in-vitro studies have
demonstrated that LMP-1 can upregulate epidermal growth factor receptor (EGFR) in
epithelial cells. It was not established whether this cellular effect exists in
NPC. To assess the association between LMP-1 and EGFR in NPC tissues, 60 NPC
specimens were examined by immunohistochemistry using anti-LMP-1 antibody (CS 1
4) and anti-EGFR antibodies (EGFR 1, EGFR 1005). The results revealed that 41
(68.3%) specimens were immunopositive for LMP-1 and 44 (73.3%) specimens over
expressed EGFR. Morphologically, the expressions of LMP-1 and EGFR were
homogeneously distributed in the tumor nests. In addition, the correlation
between LMP-1 and EGFR was statistically significant (P<0.001, chi2 test, d.f. =
1). To elucidate further the correlation between LMP-1 and EGFR in vivo and in
situ, an indirect dual immunofluorescence assay was conducted, using secondary
antibodies conjugated with fluorescein isothiocyanate (FITC) or indocarbocyanine
(Cy3). The results disclosed an intimate co-expression of LMP-1 and EGFR. In
summary, the data indicate that over-expression of EGFR is a common phenomenon in
NPC, and that EGFR is co-expressed with LMP-1 in NPC. Thus, EBV may play a role
in the tumorigenesis of NPC through the effects of LMP-1 and EGFR.
PMID- 10665645
TI - Correlation of clinicopathologic features of resected hepatocellular carcinoma
with hepatitis C virus genotype.
AB - Clinicopathologic findings in patients with hepatocellular carcinoma complicating
hepatitis C virus and outcomes after liver resection were compared between
different viral genotypes. One hundred and forty-seven patients with both anti
hepatitis C virus antibody and hepatitis C virus RNA in their sera underwent
curative resection for hepatocellular carcinoma in our department between 1991
and 1997. Of these patients, 115 were infected with hepatitis C virus genotype 1b
(group 1), and 32 were infected with 2a or 2b (group 2). Clinicopathologic
findings and outcomes after operation were compared between the two groups.
Alanine aminotransferase activity was significantly higher in group 2 than in
group 1. Genotypes did not differ concomitantly with histopathologic features of
the carcinoma or adjacent hepatic tissue. Although the tumor-free survival rate
did not differ significantly between the two groups, recurrence was not detected
during the period beyond 3 years following operation in group 2, while
recurrences arose during that period in 16 group 1 patients, most of whom
continued to manifest active hepatitis. In 7 of these 16 patients, the recurrent
tumors were histologically multicentric in origin. The cumulative survival rate
was significantly lower in group 1 than 2. Multivariate analysis indicated that
genotype 1b was an independent risk factor for short survival. Patients infected
with genotype 1b may have a relatively high risk of ongoing hepatocarcinogenesis
and more aggressive progression of associated liver dysfunction, resulting in a
poorer outcome than with other genotypes.
PMID- 10665646
TI - Beta-catenin accumulation and mutation of exon 3 of the beta-catenin gene in
hepatocellular carcinoma.
AB - A study was conducted to clarify the contribution of beta-catenin accumulation
and mutation of the beta-catenin gene to hepatocarcinogenesis. Beta-catenin
accumulation was examined immunohistochemically in 38 paired samples of
hepatocellular carcinoma (HCC) and corresponding non-cancerous liver tissue. Gene
mutation was analyzed by polymerase chain reaction-single strand conformation
polymorphism (PCR-SSCP) and direct sequencing using intronic primers encompassing
exon 3. Neither accumulation nor mutation was detected in non-cancerous liver
tissues that showed no remarkable histological features, chronic hepatitis or
liver cirrhosis. Accumulation of beta-catenin was seen in the nucleus, cytoplasm
or cell membrane in 15 of 38 (39%) HCC samples, and gene mutation was seen in 9
of 38 (24%) HCC samples. Although there was a significant correlation between
accumulation and mutation (P<0.01), six HCCs without mutation also showed
accumulation. Samples of early HCC showed neither accumulation nor mutation, and
accumulation and mutation were each correlated significantly with portal vein
tumor involvement (P<0.05). The present results indicate that (1) mutation of
exon 3 of the beta-catenin gene can lead to beta-catenin accumulation, although
other mechanisms of accumulation may also operate in HCC, and (2) beta-catenin
accumulation and mutation of the beta-catenin gene are not early events in
hepatocarcinogenesis, and may be associated with the malignant progression of
HCC.
PMID- 10665647
TI - Frameshift mutations and a length polymorphism in the hMSH3 gene and the spectrum
of microsatellite instability in sporadic colon cancer.
AB - Mutations in the hMVSH3 gene in sporadic colon cancer with microsatellite
instability (MSI) were investigated, since several mismatch repair genes were
known to be mutated in cancers with MSI, but only deletions in the (A)8 region in
the hMSH3 gene have been reported. We also analyzed the relationships between
hMSH3 mutations and the spectrum of MSI. We screened MSI in 79 sporadic colon
cancer samples using mono- and dinucleotide repeat markers and the samples with
MSI were further analyzed for tri- and tetranucleotide repeat instability and
mutations in the hMSH3 gene by polymerase chain reaction-single strand
conformation polymorphism (PCR-SSCP) analysis. Five (6%) out of 79 tumors were
MSI-H and 15 (19%) were MSI-L. Two MSI-H tumors showed insertion in the (C)8
region in the hMSH6 gene and one tumor showed insertion and deletion in the (A)8
region in the hMSH3 gene, and two of the three above tumors showed MSI in tri-and
tetranucleotide repeats. One MSI-L tumor showed somatic alteration in a 9-bp
repeat sequence in hMSH3. No frameshift mutations were found in the (A)7 and (A)6
regions in hMSH3. Thus, we confirmed that the (A)8 region in hMSH3 is a hot spot
and mutations in the (A)7 and (A)6 regions in hMSH3 are not common. The hMSH3
mutation may enhance genomic instability in some colorectal cancers.
PMID- 10665648
TI - Infrequent BCL10 mutations in B-cell non-Hodgkin's lymphomas.
AB - The BCL10 gene was recently isolated from the breakpoint region of
t(1;14)(p22;q32) in mucosa-associated lymphoid tissue (MALT) lymphomas. Somatic
mutations of BCL10 were found in not only t(1;14)-bearing MALT lymphomas, but
also a wide range of other tumors. To clarify the actual frequency and spectrum
of BCL10 mutations in primary B-cell non-Hodgkin's lymphomas (NHL), we examined a
total of 139 NHL cases comprising 25 with MALT lymphomas, 54 with follicular B
cell lymphomas (FCL), and 60 with diffuse large B-cell lymphomas (DLBL).
Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and
sequencing analyses led to the identification of four nucleotide changes in FCL
and one in DLBL. In contrast, no BCL10 mutations were found in our series of MALT
lymphomas. While screening for mutations, we also found three polymorphic
sequence variants at codons 5 and 213 and in intron 1 of the BCL10 gene. Our
results strongly suggest that somatic mutations of BCL10, if they occur at all,
are rare in B-cell NHLs and do not commonly contribute to their molecular
pathogenesis.
PMID- 10665649
TI - C-kit gene abnormalities in gastrointestinal stromal tumors (tumors of
interstitial cells of Cajal.
AB - Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the
GI tract, and expresses KIT and CD34 in most cases. Gain-of-function mutation of
the c-kit proto-oncogene has been described, but its significance in GIST has not
yet been fully evaluated. Mutation in exon 11 of the c-kit gene was determined by
both polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)
analysis and direct sequencing in primary and metastatic GISTs and esophageal
leiomyomas in Japanese subjects. C-kit gene mutation was identified in 15 of 48
primary GISTs (31%), four of seven metastatic GISTs, but none of the leiomyomas.
Three mutations were mis-sense point mutations, and 16 were in-frame deletions of
3-48 bp. C-kit gene mutation was observed equally in low- and high-risk groups,
and was not related to any clinical and pathologic factors, phenotypes or Ki-67
labeling index (LI) of tumor cells. In five of 15 deletion mutations (four in
primary tumors and one in a metastatic tumor), the mutations were present at the
distal location of exon 11 of the c-kit gene, which was a minor mutation in
previous reports from Finland and the USA. C-kit gene mutations in GIST are not
always related to a poor prognosis, but further comparative studies are necessary
in Western and Japanese populations.
PMID- 10665650
TI - Frequent allelic imbalance on chromosome 18q21 in early superficial colorectal
cancers.
AB - Genetic alterations in early superficial colorectal cancers have rarely been
reported. In the present study, we searched for alterations in the APC and p53
genes in 27 superficial (20 depressed and 7 elevated) and 21 protruding
colorectal cancers with submucosal invasion by means of PCR-single strand
conformation polymorphism. Allelic imbalance (AI) on five loci, i.e., 1p34-36,
8p21-22, 14q32, 18q21 and 22q12-13, was also analyzed. Since a high incidence of
18q21 AI was detected in the superficial depressed cases, we further screened for
alterations in Smad2, Smad4 and DCC. APC alterations were observed in three
superficial depressed, one superficial elevated, and 11 protruding colorectal
cancers, indicating that the frequency of APC alterations in superficial
depressed cases was significantly lower than that in the protruding ones. There
was no significant association between p53 alterations and macroscopic types. AI
on 18q21 (13/20, 65%) was much higher than those on the other four loci in the
superficial depressed cases. Moreover, the frequency of 18q21 AI in the
superficial depressed cases was significantly higher than that in the protruding
ones. Smad4 alterations were only detected in 1 of the 13 superficial depressed
and 3 of the 17 protruding cases, while Smad2 and DCC alterations were not
detected in any case examined. These data suggest that the carcinogenetic
pathways of protruding and superficial depressed colorectal cancers are
different, and that alterations of tumor suppressor gene(s) located on 18q21
other than Smad2, Smad4 and DCC might be associated with most superficial
depressed colorectal cancers.
PMID- 10665651
TI - Cyclooxygenase-2 (COX-2) mRNA expression levels in normal lung tissues and non
small cell lung cancers.
AB - One of the cyclooxygenase (COX) isoforms, COX-2, is overexpressed in various
human cancers. In this study, we examined the gene expression levels of COX-2 in
primary non-small cell lung cancers (NSCLC), metastatic lymph nodes, and normal
lung tissues. The expression levels of the COX-2 gene were assessed by means of
the reverse transcription polymerase chain reaction in 76 autopsy samples (29
primary NSCLC, 29 corresponding normal lung tissues, and 9 metastatic lymph
nodes). The expression levels in NSCLC (both adenocarcinomas and squamous cell
carcinomas) were significantly higher than in normal lung tissues and were
significantly higher in adenocarcinomas than in squamous cell carcinomas.
Differences between the levels of expression of COX-2 in primary tumors and their
corresponding metastatic lymph nodes in 9 adenocarcinoma patients were not
significant. Our results indicate that COX-2 may be associated with
carcinogenesis of NSCLC, and that it may be a target for the treatment of NSCLC.
PMID- 10665652
TI - Expression of platelet-derived endothelial cell growth factor/thymidine
phosphorylase in human bladder cancer.
AB - We investigated the expression of platelet-derived endothelial cell growth
factor/thymidine phosphorylase (PD-ECGF/TP) in primary bladder cancer, its
association with clinicopathologic findings, and their prognostic value. mRNA was
extracted from 20 bladder cancer specimens and 6 normal bladder mucosal tissues.
Relative amounts of PD-ECGF/TP mRNA were evaluated by reverse transcriptase
polymerase chain reaction (RT-PCR) and compared with the level of glyceraldehyde
3-phosphate dehydrogenase mRNA (used as an internal standard). PD-ECGF/TP
expression was examined by immunohistochemistry in 85 patients who underwent
cystectomy for bladder cancer. Serum PD-ECGF/TP levels were measured in 23
patients using a sandwich-type enzyme-linked immunosorbent assay. By RT-PCR
analysis, expression of PD-ECGF/TP was found to be 7-fold higher in invasive
tumors than in superficial tumors (P<0.01) and 9-fold higher than in normal
bladder (P<0.01). Out of 85 transitional cell carcinoma tissue samples, 69 (81%)
were evaluated as PD-ECGF/TP-positive by immunohistochemical staining. PD-ECGF/TP
expression correlated significantly with tumor grade (P = 0.001), depth of
invasion (P = 0.012), and lymphatic invasion (P = 0.01). No correlation was found
between expression of PD-ECGF/TP and the number of tumors, tumor configuration,
lymph node involvement, venous invasion, c-erbB-2 expression, or overall
survival. We could not detect a significant serum level of PD-ECGF/TP in any
patient. The results suggest that PD-ECGF/TP might give valuable information for
bladder cancer management, though it may not be a good new tumor marker for
bladder cancer.
PMID- 10665653
TI - Gamma-irradiation deregulates cell cycle control and apoptosis in nevoid basal
cell carcinoma syndrome-derived cells.
AB - The nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant
disorder characterized by nevi, palmar and plantar pits, falx calcification,
vertebrate anomalies and basal cell carcinomas. It is well known in NBCCS that
gamma-irradiation to the skin induces basal cell carcinomas or causes an
enlargement of the tumor size, although the details of the mechanism remain
unknown. We have established lymphoblastoid cell lines from three NBCCS patients,
and we present here the first evidence of abnormal cell cycle and apoptosis
regulations. A novel mutation (single nucleotide deletion) in the coding region
of the human patched gene, PTCH, was identified in two sibling patients, but no
apparent abnormalities were detected in the gene of the remaining patient.
Nevertheless, the three established cell lines showed similar features in the
following analyses. Flow cytometric analyses revealed that the NBCCS-derived
cells were accumulated in the G2M phase after gamma-irradiation, whereas normal
cells showed cell cycle arrest both in the G0G1 and G2M phases. The fraction of
apoptotic cells after gamma-irradiation was smaller in the NBCCS cells. The level
of p27 expression markedly decreased after gamma-irradiation in the NBCCS cells,
although the effects of the irradiation on the expression profiles for p53, p21
and Rb did not differ in normal and NBCCS cells. These findings may provide a
clue to the molecular mechanisms of tumorigenesis in NBCCS.
PMID- 10665654
TI - Significance of heterogeneous nuclear ribonucleoprotein B1 as a new early
detection marker for oral squamous cell carcinoma.
AB - The development of an early tumor detection marker for oral cancer is an obvious
need due to the high recurrence rate and poor survival rate. Based on our
previous report that overexpression of heterogeneous nuclear ribonucleoprotein
(hnRNP) B1 protein was found in 100% of squamous cell carcinomas of human lung,
we applied the same immunohistochemical method, using anti-hnRNP B1 antibody, to
human oral squamous cell carcinoma (OSCC). Seven human tissue sections of OSCC
showed strong staining with anti-hnRNP B1 antibody, and hnRNP B1 protein of 37
kDa was identified in protein fractions isolated from six of the cancerous tissue
sections, while it was not found in adjacent noncancerous tissue. Moreover, three
non-homogeneous (nodular) leukoplakia sections showed significant anti-hnRNP B1
staining. The results suggest that this antibody detects precancerous lesions as
well as advanced lesions (stages I to IV) of OSCC. We also present positive
results of cytodiagnosis for two smear specimens. All of the above results
indicate that hnRNP B1 is a new and useful marker for early detection of OSCC.
PMID- 10665655
TI - G1-checkpoint function including a cyclin-dependent kinase 2 regulatory pathway
as potential determinant of 7-hydroxystaurosporine (UCN-01)-induced apoptosis and
G1-phase accumulation.
AB - 7-Hydroxystaurosporine (UCN-01), which was originally identified as a protein
kinase C selective inhibitor, is currently in clinical trials as an anti-cancer
drug. We previously showed that UCN-01 induced preferential G1-phase accumulation
in tumor cells and this effect was associated with the retinoblastoma (Rb)
protein and its regulatory factors, such as cyclin-dependent kinase 2 (CDK2) and
CDK inhibitors p21Cip1/WAF1 and p27Kip1. We demonstrate here that G1-phase
accumulation was induced by UCN-01 in Rb-proficient cell lines (WiDr and HCT116
human colon carcinomas and WI-38 human lung fibroblast), and it was accompanied
by dephosphorylation of Rb. In addition, UCN-01-induced G1-phase accumulation was
also demonstrated in a Rb-defective cell line (Saos-2 human osteosarcoma), but
not in a simian virus 40 (SV40)-transformed cell line (WI-38 VA13). Apoptosis was
induced by UCN-01 in the two Rb-deficient cell lines, but not in the other Rb
proficient cell lines. These observations suggest that G1-checkpoint function
might be important for cell survival during UCN-01 treatment. In addition, there
may be a UCN-01-responsive factor in the G1-checkpoint machinery other than Rb
which is targeted by SV40. Further studies revealed a correlation between UCN-01
induced G1-phase accumulation and reduction of cellular CDK2 kinase activity.
This reduction was strictly dependent on down-regulation of the Thr160
phosphorylated form of CDK2 protein, and coincided in part with up-regulation of
p27Kip1, but it was independent of the level of the p21Cip1/WAF1 protein. These
results suggest that G1-checkpoint function, including a CDK2-regulatory pathway,
may be a significant determinant of the sensitivity of tumor cells to UCN-01.
PMID- 10665656
TI - Cisplatin-resistant HeLa cells are resistant to apoptosis via p53-dependent and
independent pathways.
AB - Since HeLa cells possess very little functional p53 activity, they could be
originally resistant to genotoxic stress-induced apoptosis. Therefore, it is
likely that the drug-resistant cells derived from HeLa cells are more resistant
to apoptosis. The aim of this study was to determine whether cisplatin-resistant
cells derived from HeLa cells have an apoptosis-resistant phenotype. A cisplatin
resistant cell subline, HeLa/CDDP cells, showed a 19-fold resistance to cisplatin
compared with the parent cells. The subline showed a collateral sensitivity to
paclitaxel. An equitoxic dose (IC50) of cisplatin produced DNA fragmentation in
HeLa cells but not in HeLa/CDDP cells. Transfection of wild-type p53 gene
enhanced the cytotoxicity of cisplatin and cisplatin-induced apoptosis in HeLa
cells but not in HeLa/CDDP cells, although it caused p53 overexpression in both
cell lines. The expression of caspase 1 (interleukin-1beta-converting enzyme,
ICE) mRNA and the overexpression of bax protein were observed only in HeLa cells.
Paclitaxel-induced DNA fragmentation appeared less in HeLa/CDDP cells than in
HeLa cells. p53 gene transfection did not affect the extent of DNA fragmentation
in either cell line, suggesting that paclitaxel may induce p53-independent
apoptosis. These findings suggest that HeLa/CDDP cells may have an acquired
phenotype that is resistant to p53-dependent and -independent apoptosis.
PMID- 10665657
TI - Interaction of docetaxel ("Taxotere") with human P-glycoprotein.
AB - The interaction of docetaxel ("Taxotere") with P-glycoprotein (P-gp) was examined
using porcine kidney epithelial LLC-PK1 and LLC-GA5-COL150 cells, overexpressing
human P-gp selectively on the apical plasma membrane by transfection of human
MDR1 cDNA into the LLC-PK1 cells. The basal-to-apical transport of [14C]docetaxel
in LLC-GA5-COL150 cells significantly exceeded that in LLC-PK1 cells, but the
apical-to-basal transport was decreased in LLC-GA5-COL150 cells. The
intracellular accumulation after its basal or apical application to LLC-GA5
COL150 cells was 4- to 20-fold lower than that of LLC-PK1 cells. Multidrug
resistance (MDR) modulators, i.e., cyclosporin A and SDZ PSC 833, inhibited the
basal-to-apical transport and increased the apical-to-basal transport of
[14C]docetaxel in LLC-GA5-COL150 cells, but verapamil affected only apical-to
basal transport. The intracellular accumulation after basal or apical application
to LLC-GA5-COL150 cells was also increased by these three MDR modulators. These
observations demonstrated that docetaxel is a substrate for human P-gp,
suggesting that docetaxel-drug interactions occur via P-gp. The inhibition of
[14C]docetaxel transport by the MDR modulators, as well as daunorubicin and
vinblastine, was also found in LLC-PK1 cells, which endogenously express P-gp at
lower levels, and concentrations showing similar levels of inhibition were lower
than those in the case of LLC-GA5-COL150 cells. These observations indicate that
it is necessary to consider the pharmacokinetic and pharmacodynamic interactions
of docetaxel via P-gp.
PMID- 10665658
TI - Evaluation of antivascular and antimitotic effects of tubulin binding agents in
solid tumor therapy.
AB - Tubulin binding agents (TBAs) reduce tumor perfusion and inhibit mitosis of tumor
cells in solid tumors, but it is not clear which effects contribute to the
suppression of solid tumor growth. We evaluated the antivascular and antimitotic
effects of several TBAs, combretastatin A-4 (CS A-4) phosphate, AC-7700, a novel
CS A-4 derivative, colchicine, E7010, and vinblastine, on subcutaneous (s.c.)
murine colon26 adenocarcinoma (c26). Tolerable doses of vinblastine and E7010)
strongly inhibited tumor growth and induced mitotic arrest of tumor cells without
affecting tumor perfusion. Colchicine had no effect on tumor growth and
perfusion. When the injected dose was increased to the lethal range, however,
these drugs markedly reduced tumor perfusion and caused necrosis of tumor tissue.
Within the tolerable dose range, AC-7700 both strongly suppressed tumor growth
and reduced tumor perfusion, and CS A-4 phosphate also exhibited a moderate
antivascular effect. To evaluate the contribution of antivascular activity of
TBAs to tumor growth suppression, excluding their direct cytotoxic effect on
tumor cells, we established c26/acr, which is resistant to TBAs in vitro.
Although E7010 showed a reduced suppressive effect on s.c. c26/acr tumor growth
as compared with its effect on wild-type c26, AC-7700 remained potent against
both cell lines. These results indicate that TBAs exert antivascular and
antimitotic effects on solid tumors with marked differently effective dose ranges
from agent to agent, and that the antivascular effect of TBAs inhibits solid
tumor growth independently of the direct cytotoxic effect on tumor cells.
PMID- 10665659
TI - Clinical teratology: identifying teratogenic risks in humans.
PMID- 10665660
TI - Genetic landmarks through philately--Henry Louis 'Lou' Gehrig and amyotrophic
lateral sclerosis.
PMID- 10665661
TI - Human renin gene BglI dimorphism associated with hypertension in two independent
populations.
AB - The renin (REN) gene is a good candidate that could underlie an individual's
genetic susceptibility to human essential hypertension (EHT). We describe here a
polymerase chain reaction-based assay for detection of a BglI dimorphic site
located in the first intron of the REN gene. In this retrospective, case-control,
association study, we investigated BglI allele and genotype distributions in 554
subjects (280 hypertensives and 274 normotensives) from the United Arab Emirates
(UAE) - a genetically homogeneous ethnic population with no history of smoking or
alcohol consumption - and in 485 hypercholesterolemic, US Caucasian subjects (250
hypertensives and 235 normotensives). A statistically significant association was
found between alleles on which the BglI site is present [BglI(+)] and clinical
diagnosis of EHT in the UAE sample group (odds ratio = 2.69, p = 0.0006), and a
similar trend was observed in the US group (odds ratio = 1.97, p = 0.01). BglI(+)
homozygous status was also investigated in the US group and found to be
associated with elevated systolic and diastolic blood pressure values
(respectively, 144.8+/-26.1 vs. 134.1+/-23.0 mm Hg, p = 0.04; and 91.0+/-12.5 vs.
82.2+/-12.7 mm Hg, p = 0.009). In conclusion, variations of the REN (or of a
nearby) gene that may be in linkage disequilibrium with the REN BglI(+) marker
could play a role in contributing to an increased individual's genetic
susceptibility to EHT in the UAE population and amongst US hypercholesterolemic
Caucasians. Such a genetic influence, which seems to show a recessive mode of
inheritance, could also be implicated in raising both systolic and diastolic
blood pressures.
PMID- 10665662
TI - Perceptions of the outcome of orthopedic surgery in patients with
chondrodysplasias.
AB - As part of a larger survey of patients with chondrodysplasias, 197 patients or
their parents were asked whether they had undergone orthopedic surgery related to
their chondrodysplasia and, if so, to rate their impression of the outcome.
Seventy-four patients (37.6%) had undergone a total of 152 procedures (221 if
concurrent bilateral operations are counted separately). The percentage of
patients treated surgically ranged from a low of 8.3% for hypochondroplasia to a
high of 87.5% for diastrophic dysplasia. Of the patients who had surgery, the
mean number of procedures per patient ranged from 1.0 for hypochondroplasia to
2.69 for pseudoachondroplasia. Of 180 individual procedures related to the limbs,
the outcome in 88.8% was judged 'a bit better' or higher and in 68.8% 'much
better' or higher. The responses ranged from a low of 70.4 and 66.7%,
respectively for proximal femoral osteotomies to a high of 100 and 85.9% for hip
replacement. The comparable figures for spine related surgery were 81.8 and 48.5%
with a low of 58.3 and 50.0% for foramen magnum-cervical surgery and a high of
93.8 and 43.8% for thoracolumbar procedures. The expressed perception of lack of
satisfaction varied not only by procedure but by diagnosis. Overall, patients
perceived a high level of post-surgical improvement, although a number
experienced subsequent deterioration and the need for further intervention.
PMID- 10665663
TI - Molecular genetics of Turner syndrome: correlation with clinical phenotype and
response to growth hormone therapy.
AB - To correlate the origin of the retained X in Turner syndrome with phenotype, pre
treatment height and response to recombinant human growth hormone (rhGH) therapy,
systematic clinical assessment and molecular studies were carried out in 33 Greek
children with Turner syndrome and their parents including 18 children with 45,X
and 15 with X-mosaicism. Microsatellite markers on X chromosomes (DXS101 and
DXS337) revealed that the intact X was paternal (Xp) in 15/30 and maternal (Xm)
in 15/30 children, while 3/33 families were non-informative. No significant
relationship was found between parental origin of the retained X and birth
weight/length/gestational age, blepharoptosis, pterygium colli, webbed neck, low
hairline, abnormal ears, lymphoedema, short 4th metacarpal, shield chest, widely
spaced nipples, cubitus valgus, pigmented naevi, streak gonads, and
cardiovascular/renal anomalies. With regard to the children's pre-treatment
height, there was a significant correlation with maternal height and target
height in both Xm and Xp groups. No differences were found between Xm and Xp
groups and the improvement of growth velocity (GV) during the first and second
year of rhGH administration, while for both groups GV significantly improved with
rhGH by the end of the first and the second year. To our knowledge, this is the
first attempt to correlate the parental origin of Turner syndrome with the
response to rhGH therapy.
PMID- 10665664
TI - Relation of mathematical ability to psychosis in Iceland.
AB - A study of mathematically gifted Icelanders demonstrates an increased risk of
mental illness in their ranks. Psychotic disorders are also frequent among their
relatives. Linkage of academic records with previously published data on the
family distribution of psychosis reveals a pattern compatible with the hypothesis
that high arousal plays a role in reasoning ability.
PMID- 10665665
TI - Prevalence of human leukocyte antigen DQA1 and DQB1 alleles in Kuwaiti Arab
children with type 1 diabetes mellitus.
AB - The prevalence of human leukocyte antigen (HLA) DQB1 and DQA1 alleles has been
determined in 78 Kuwaiti Arab children with insulin-dependent diabetes mellitus
(IDDM) and in 57 normal healthy controls with similar ethnic background. The
typing of HLA-DQ alleles was carried out using an allele-specific DNA-based
polymerase chain reaction (PCR) SSP method. DR typing was also performed in 212
control subjects using PCR-SSP (sequence specific primer) method. A significantly
higher frequency of DQB1*0201 allele was found in IDDM cases compared to the
controls (p<0.001). There was no significant difference in the prevalence of DQB1
alleles *0302, *0501, and *0602 between IDDM cases and the controls. In contrast,
DQB1 alleles *0301, *0402, *0502, *0602, and *0603 were represented at a somewhat
higher frequency in controls compared to the IDDM cohort. The frequency of DQA1
allele *0301, which encode for an Arg at codon 52, was significantly higher in
the IDDM patients compared to the controls (p<0.001). The frequency of DQA1
allele *0302 was also higher in IDDM cases than controls (p = 0.034) but the
difference was less pronounced than DQA1*0301. Amongst the Arg52 alleles, no
significant difference was detected in the frequency of *0401 between IDDM cases
and the controls and the allele *0501 was detected only in controls. For non
Arg52 alleles *0103, *0104, and *0201, the differences in the two groups were not
significant, with the exception of allele *0104 (p = 0.024). DR3 was the most
common type in the Kuwaiti general population (28%) and DRB1*0301 was detected in
41% of the individuals with DR3 specificity. Analysis of HLA-DQBI/DQA1 haplotypes
from IDDM cases and controls revealed a significantly high frequency of haplotype
DQA1*0301/DQB1*0201 between Kuwaiti IDDM cases (49/78, 63%) and the controls
(8/57, 14%).
PMID- 10665666
TI - Proximal myotonic myopathy: clinical and molecular investigation of a Norwegian
family with PROMM.
AB - Proximal myotonic myopathy (PROMM) was first described in 1994 as a multisystem
disorder with similarity to myotonic dystrophy (DM), but without the abnormal
(CTG)n expansion in the DM protein kinase (DMPK) gene. The inheritance is
autosomal dominant and the clinical features include myotonia, proximal muscle
weakness and cataract. Linkage analysis in nine German PROMM families has
indicated the possibility of linkage to DM2 locus on chromosome 3. We report a
Norwegian PROMM family in which the proband was clinically diagnosed as DM but
without the (CTG)n expansion. Using an intragenic marker we showed that the DMPK
gene did not segregate with the disease in this family. All family members are
heterozygous for the R894X mutation in CLCN1 gene. Linkage analysis could not be
performed, but haplotyping probably excludes the DM2 locus as the disease locus
in this family. The present family emphasises that myalgia is a prominent symptom
in PROMM and the clinical differences may be explained by genetic heterogeneity.
This family will be reinvestigated along with the identification of candidate
genes or regions in larger PROMM families.
PMID- 10665667
TI - Postaxial polydactyly and Dandy-Walker malformation. Further nosological
comments.
PMID- 10665668
TI - Search for uniparental disomy 14 in balanced Robertsonian translocation carriers.
PMID- 10665669
TI - Prenatal diagnosis of peroxisome biogenesis disorders by means of
immunofluorescence staining of cultured chorionic villous cells.
PMID- 10665670
TI - A de novo heterozygous deletion of 42 base-pairs in the noggin gene of a
fibrodysplasia ossificans progressiva patient.
PMID- 10665671
TI - Sensory feedback in artificial control of human mobility.
AB - Artificial motor control systems may reduce the handicap of motor impaired
individuals. Sensors are essential components in feedback control of these
systems and in the information exchange with the user. The objective of this
paper is to give an overview of the applications of sensors in the artificial
control of human mobility. These applications may either require an accurate
estimate of the measured physical quantities or can be based on learning the
relation between sensory information and control actions by example. Actual use
of sensors in artificial motor control systems requires that the user experienced
complexity of the system is not increased, while improving the repeatable and
flexible functioning of the system. Therefore, the sensors need to be integrated
with the mechanical part of the artificial support system or implanted, the
information exchange between sensor and controller should be wireless and
automatic in-use calibration is a desired feature.
PMID- 10665672
TI - Interfacing the body's own sensing receptors into neural prosthesis devices.
AB - Functional Electric Stimulation (FES) is today available as a tool in muscle
activation used in picking up objects, in standing and walking, in controlling
bladder emptying, and for breathing. Despite substantial progress over nearly
three decades of development, many challenges remain to provide a more efficient
functionality of FES systems. The most important of these is an improved control
of the activated muscles. Instead of artificial sensors for feedback, new
developments in electrodes to do long-term and reliable recordings from
peripheral nerves emphasize the use of the body's own sensors. These are already
installed and optimised through millions of years of natural evolution. This
paper presents recent results on a system using electrical stimulation of motor
nerves to produce movement and using the natural sensors as feedback signals to
control the stimulation that can replicate some of the functions of the spinal
cord and its communication with the brain. We have used the nerve signal recorded
from cutaneous nerves in two different human applications: (1) to replace the
external heel switch of a system for correction of spastic drop foot by peroneal
stimulation, and (2) to provide an FES system for restoration of hand grasp with
sensory feedback from the fingertip. For the bladder function, the sacral root
stimulator is a useful control tool in emptying the bladder. To decide when to
stimulate, we are at present carrying out experiments on pigs and cats using cuff
electrodes on the pelvic nerve and sacral roots to record the neural information
from bladder afferents. This information can potentially be used to inhibit
unwanted bladder contractions and to trigger the FES system and thereby bladder
emptying. Future research will show whether cuffs and other types of electrodes
can be used to reliably extract signals from the large number of other receptors
in the body to improve and expand on the use of natural sensors in clinical FES
systems.
PMID- 10665673
TI - Strategies for providing upper extremity amputees with tactile and hand position
feedback--moving closer to the bionic arm.
AB - A continuing challenge for prostheses developers is to replace the sensory
function of the hand. This includes tactile sensitivity such as finger contact,
grip force, object slippage, surface texture and temperature, as well as
proprioceptive sense. One approach is sensory substitution whereby an intact
sensory system such as vision, hearing or cutaneous sensation elsewhere on the
body is used as an input channel for information related to the prosthesis. A
second technique involves using electrical stimulation to deliver sensor derived
information directly to the peripheral afferent nerves within the residual limb.
Stimulation of the relevant afferent nerves can ultimately come closest to
restoring the original sensory perceptions of the hand, and to this end,
researchers have already demonstrated some degree of functionality of the
transected sensory nerves in studies with amputee subjects. This paper provides
an overview of different types of nerve interface components and the advantages
and disadvantages of employing each of them in sensory feedback systems. Issues
of sensory perception, neurophysiology and anatomy relevant to hand sensation and
function are discussed with respect to the selection of the different types of
nerve interfaces. The goal of this paper is to outline what can be accomplished
for implementing sensation into artificial arms in the near term by applying what
is present or presently attainable technology.
PMID- 10665674
TI - Robots with a gentle touch: advances in assistive robotics and prosthetics.
AB - As healthcare costs rise and an aging population makes an increased demand on
services, so new techniques must be introduced to promote an individuals
independence and provide these services. Robots can now be designed so they can
alter their dynamic properties changing from stiff to flaccid, or from giving no
resistance to movement, to damping any large and sudden movements. This has some
strong implications in health care in particular for rehabilitation where a robot
must work in conjunction with an individual, and might guiding or assist a
persons arm movements, or might be commanded to perform some set of autonomous
actions. This paper presents the state-of-the-art of rehabilitation robots with
examples from prosthetics, aids for daily living and physiotherapy. In all these
situations there is the potential for the interaction to be non-passive with a
resulting potential for the human/machine/environment combination to become
unstable. To understand this instability we must develop better models of the
human motor system and fit these models with realistic parameters. This paper
concludes with a discussion of this problem and overviews some human models that
can be used to facilitate the design of the human/machine interfaces.
PMID- 10665675
TI - Overview of clinical trials with MIT-MANUS: a robot-aided neuro-rehabilitation
facility.
AB - We are applying robotics and information technology to assist, enhance, and
quantify neuro-rehabilitation. Our goal is a new class of interactive, user
affectionate clinical devices designed not only for evaluating patients, but also
for delivering meaningful therapy via engaging "video games". Notably, the novel
robot MIT-MANUS has been designed and programmed for clinical neurological
applications, and has undergone extensive clinical trials for more than four
years at Burke Rehabilitation Hospital - White Plains, NY. This paper will review
results of the first clinical trial of 20 patients, which showed that: - Stroke
patients treated daily with additional robot-aided therapy during acute
rehabilitation had improved outcome in motor activity at hospital discharge, when
compared to a control group that received only standard acute rehabilitation
treatment. - This improved outcome was sustained after three years. - The neuro
recovery process continued far beyond the commonly accepted 3 months post-stroke
interval.
PMID- 10665676
TI - Human--machine load sharing in rehabilitation robotics.
AB - A force-assist mechanism has been developed to mount on the Chameleon - a
wheelchair mounted rehabilitation robot. The device will amplify the forces
applied by the user, making it possible to lift a large weight with a small
force. This paper describes the test-bed development; instrumentation of the
Chameleon with power assistance; and preliminary results on system efficacy.
PMID- 10665677
TI - Mechatronic assessment of arm impairment after chronic brain injury.
AB - Significant potential exists for mechatronic devices to improve assessment and
treatment of individuals with a movement disability following stroke, traumatic
brain injury, or cerebral palsy. We report the use of a mechatronic device for
evaluation of the arm after chronic brain injury. We performed a series of
experiments with the device in order to identify the relative contribution of
three different motor impairments to decreased active range of motion of reaching
in five brain-injured subjects. Our findings were that passive tissue restraint
and agonist weakness, rather than antagonist restraint, were the most common
contributors to decreased active range of motion. These results demonstrate the
feasibility of objective assessment of functional movement using a mechatronic
device, and could provide the basis for improved, individualized treatment
planning and monitoring following brain injury.
PMID- 10665678
TI - Postural activity of constrained subject in response to disturbance in sagittal
plane.
AB - The study examines postural activity of a constrained subject in response to
various disturbances in the sagittal plane. Three different initial standing
postures were examined. Each response to a perturbation was divided into three
consecutive phases according to the intensity of the muscular activity. The
relation of the ankle joint torque versus the ankle joint angle was studied. A
linear relationship, resulting in constant ankle stiffness, was observed in each
phase of the response. Only negligible differences in the stiffness values were
observed among different phases. The results indicate an ankle stiffness value of
10 N m/o for the majority of initial stance postures and perturbation
intensities.
PMID- 10665679
TI - Feedback control of unsupported standing.
AB - This paper presents the results of continuing work on feedback control of
unsupported standing in paraplegia. Our experimental setup considers a situation
in which all joints above the ankle are braced, and stabilising torque at the
ankle is generated by stimulation of the plantarflexors. A previous study showed
that short periods of unsupported standing with paraplegic subjects could be
achieved. In order to improve consistency and reliability of unsupported standing
we are currently investigating several modifications to the control strategy. The
paper reports progress towards this goal.
PMID- 10665680
TI - Towards applicable ballistic walking.
AB - Ballistic walking has been a topic of research in biomechanics and robotics
several times. The main advantages of this approach are: self-organizing
properties, minimal energetic expenditure, and natural movement. This would make
ballistic walking a perfect physical principle for application in rehabilitation,
and robotics. However a typical shortcoming of this approach is that it does not
explicitly involve actuation (e.g., muscles or motors). In this work ballistic
walking is extended with variable intrinsic system parameters, which can be used
as an energy input and for disturbance control. With a limit cycle approach
walking cycles can be synthesized and cycle controllers can be designed.
Experiments with a bipedal robot and simulations illustrate the route towards
more robust, and applicable ballistic walking.
PMID- 10665681
TI - Estimating orientation with gyroscopes and accelerometers.
PMID- 10665682
TI - Design of an intramedullary leg lengthening device with a shape memory actuator.
AB - The procedure and the external fixator for lengthening long bones was developed
by G.A. Ilizarov in the late 1960's. This technique has, despite its proven
abilities for leg lengthening and correction of angular deformities, some
considerable disadvantages for the patients. Discomfort, infections and
restricted weight bearing are some reasons for the development of a completely
intramedullary device for leg lengthening. The device developed at the Laboratory
of Biomechanical Engineering, University of Twente, is a telescopic
intramedullary nail with a maximum diameter of 13 mm, which can be lengthened
with 0.5 mm steps induced by a shape memory alloy actuator. The electrical energy
for the actuator is supplied from outside the body by inductive coupling of two
solenoid coils. Internally, the electrical energy is transformed to thermal
energy by Thermofoils and Peltier-elements.
PMID- 10665684
TI - Gene therapy trials show clinical efficacy.
PMID- 10665683
TI - Good Fridays.
PMID- 10665686
TI - An ancient nation braces to fight AIDS.
PMID- 10665685
TI - Some men who take Viagra die--why?
PMID- 10665687
TI - From the Food and Drug Administration.
PMID- 10665688
TI - From the Centers for Disease Control and Prevention. Staphylococcus aureus with
reduced susceptibility to vancomycin--Illinois, 1999.
PMID- 10665689
TI - From the Centers for Disease Control and Prevention. Alcohol involvement in fatal
motor-vehicle crashes--United States, 1997-1998.
PMID- 10665690
TI - From the Centers for Disease Control and Prevention. Laboratory capacity to
detect antimicrobial resistance, 1998.
PMID- 10665691
TI - Primary angioplasty vs thrombolysis in elderly patients.
PMID- 10665692
TI - Quality of health care and the HMO marketplace.
PMID- 10665693
TI - Quality of health care and the HMO marketplace.
PMID- 10665694
TI - Quality of health care and the HMO marketplace.
PMID- 10665695
TI - Quality of health care and the HMO marketplace.
PMID- 10665696
TI - Quality of health care and the HMO marketplace.
PMID- 10665697
TI - Glycosylated hemoglobin as a diagnostic test for type 2 diabetes mellitus.
PMID- 10665698
TI - Glycosylated hemoglobin as a diagnostic test for type 2 diabetes mellitus.
PMID- 10665699
TI - Glycosylated hemoglobin as a diagnostic test for type 2 diabetes mellitus.
PMID- 10665700
TI - Long-term outcomes of persons with Lyme disease.
AB - CONTEXT: Few data exist about the long-term outcomes of patients with Lyme
disease. OBJECTIVE: To assess the long-term outcomes of patients with Lyme
disease. DESIGN: Two-part project including a community-based longitudinal cohort
study and a matched cohort study. SETTING AND PARTICIPANTS: Six hundred seventy
eight patients identified from a random sample of all reports of Connecticut
residents with suspected Lyme disease submitted to the Connecticut Department of
Public Health from 1984-1991 were evaluated in the longitudinal study; for a
random subsample of 212 patients from the larger study, 212 age-matched controls
without Lyme disease also were enrolled. MAIN OUTCOME MEASURES: Self-reports or
parents' reports of symptoms and ability to perform certain daily activities
since diagnosis of Lyme disease; scores on the 36-Item Short-Form Health Survey
and the Center for Epidemiologic Studies-Depression scale, for adults, by case
definition status and between patients and controls. RESULTS: Of the 678
patients, 51.6% were female, 34.4% were children, and 64.3% met the national
surveillance case definition for Lyme disease. Most patients (85.6%) were treated
with antimicrobial agents. Interviews were conducted a median of 51 months after
diagnosis (range, 15-135 months). An increased frequency of symptoms (eg, pain,
fatigue) or of difficulty with daily activities (eg, performing housework,
exercising) was reported by 69% of the patients, although few (19%) of these
problems were attributed to Lyme disease. Whenever there was a statistically
significant difference in the frequencies of either increased symptoms or
increased difficulties with typical activities between those who did or did not
meet the surveillance case definition, in all instances the greater frequency of
problems was in the group that did not meet the case definition. The frequencies
of reports of both increased symptoms and increased difficulties with typical
activities among patients who had been diagnosed as having Lyme disease were
similar to those among age-matched controls without Lyme disease. CONCLUSIONS: In
this cohort, although many patients reported increases in symptoms and/or
increased difficulties with typical daily activities between 1 and 11 years after
diagnosis of Lyme disease, the frequencies of these reports were similar to the
frequencies of such reports among age-matched controls without Lyme disease.
PMID- 10665701
TI - Life expectancy gains from cancer prevention strategies for women with breast
cancer and BRCA1 or BRCA2 mutations.
AB - CONTEXT: Women with BRCA1- or BRCA2-associated breast cancer are at increased
risk for contralateral breast cancer and ovarian cancer and therefore may
consider secondary cancer prevention strategies, such as prophylactic surgery and
tamoxifen therapy. It is not proven to what extent these strategies reduce risk
of second cancers in such patients. OBJECTIVE: To examine the effect of tamoxifen
therapy, bilateral prophylactic oophorectomy (PO), prophylactic contralateral
mastectomy (PCM), and combinations of these strategies on life expectancy for
women with unilateral breast cancer and a BRCA1 or BRCA2 gene mutation. DESIGN
AND SETTING: Decision analysis using a Markov model. Probabilities for developing
contralateral breast cancer and ovarian cancer, dying from these cancers, dying
from primary breast cancer, and the reduction in cancer incidence and mortality
due to prophylactic surgeries and/or tamoxifen were estimated from published
studies. PARTICIPANTS: Hypothetical breast cancer patients with BRCA1 or BRCA2
mutations facing decisions about secondary cancer prevention strategies.
INTERVENTIONS: Seven strategies, including 5 years of tamoxifen use, PO, PCM, and
combinations of these strategies, compared with careful surveillance. MAIN
OUTCOME MEASURES: Total and incremental life expectancy (LE) with each
intervention strategy. RESULTS: Depending on the assumed penetrance of the BRCA
mutation, compared with surveillance alone, 30-year-old early-stage breast cancer
patients with BRCA mutations gain in LE 0.4 to 1.3 years from tamoxifen therapy,
0.2 to 1.8 years from PO, and 0.6 to 2.1 years from PCM. The magnitude of these
gains is least for women with low-penetrance mutations (assumed contralateral
breast cancer risk of 24% and ovarian cancer risk of 6%) and greatest for those
with high-penetrance mutations (assumed contralateral breast cancer risk of 65%
and ovarian cancer risk of 40%.) Older age and poorer prognosis from primary
breast cancer further attenuate these gains. CONCLUSIONS: Interventions to
prevent second cancers, particularly PCM, may offer substantial LE gain for young
women with BRCA-associated early-stage breast cancer. Estimates of LE gain may
help women and their physicians consider the uncertainties, risks, and advantages
of these interventions and lead to more informed choices about cancer prevention
strategies.
PMID- 10665702
TI - Adult functional outcome of those born small for gestational age: twenty-six-year
follow-up of the 1970 British Birth Cohort.
AB - CONTEXT: Although studies have documented cognitive impairment in children who
were born small for gestational age (SGA), other studies have not demonstrated
differences in IQ or other cognitive scores. The need exists for long-term
studies of such children to assess functional outcomes not measurable with
standardized testing. OBJECTIVE: To determine the long-term functional outcome of
SGA infants. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: A total
of 14,189 full-term infants born in the United Kingdom on April 5 through 11,
1970, were studied as part of the 1970 British Birth Cohort; 1064 were SGA (birth
weight less than the fifth percentile for age at term). Follow-up at 5, 10, 16,
and 26 years was 93%, 80%, 72%, and 53%, respectively. MAIN OUTCOME MEASURES:
School performance and achievement, assessed at 5, 10, and 16 years; and years of
education, occupational status, income, marital status, life satisfaction,
disability, and height, assessed at 26 years, comparing persons born SGA with
those who were not. RESULTS: At 5, 10, and 16 years of age, those born SGA
demonstrated small but significant deficits in academic achievement. In addition,
teachers were less likely to rate those born SGA in the top 15th percentile of
the class at 16 years (13% vs 20%; P<.01) and more likely to recommend special
education (4.9% vs 2.3%; P<.01) compared with those born at normal birth weight
(NBW). At age 26 years, adults who were SGA did not demonstrate any differences
in years of education, employment, hours of work per week, marital status, or
satisfaction with life. However, adults who were SGA were less likely to have
professional or managerial jobs (8.7% vs 16.4%; P<.01) and reported significantly
lower levels of weekly income (mean [SD], 185 [91] vs 206 [102] pound sterling;
P<.01) than adults who were NBW. Adults who were SGA also reported significant
height deficits compared with those who were NBW (mean [SD] z score, -0.55 [0.98]
vs 0.08 [1.02]; P<.001). Similar results were also obtained after adjusting for
social class, sex, region of birth, and the presence of fetal or neonatal
distress. CONCLUSIONS: In this cohort, adults who were born SGA had significant
differences in academic achievement and professional attainment compared with
adults who were NBW. However, there were no long-term social or emotional
consequences of being SGA: these adults were as likely to be employed, married,
and satisfied with life.
PMID- 10665703
TI - Arterial hypertension and renal allograft survival.
AB - CONTEXT: Several observational studies have investigated the significance of
hypertension in renal allograft failure; however, these studies have been
complicated by the lack of adjustment for baseline renal function, leaving the
role of elevated blood pressure in allograft failure unclear. OBJECTIVE: To
examine the relationship between blood pressure adjusted for renal function and
survival after cadaveric allograft transplantation. DESIGN: Nonconcurrent
historical cohort study conducted from 1985 through 1997. SETTING: University
teaching hospital. PARTICIPANTS: A total of 277 patients aged 18 years or older
who underwent cadaveric renal transplantation without another simultaneous organ
transplantation and whose allograft was functioning for a minimum of 1 year.
Follow-up continued through 1997 (mean follow-up, 5.7 years). MAIN OUTCOME
MEASURE: Time to allograft failure (defined as death, return to dialysis, or
retransplantation) by systolic, diastolic, and mean arterial blood pressure
measurements at 1 year after transplantation. RESULTS: Multivariate Cox
proportional hazards modeling demonstrated that nonwhite ethnicity, history of
acute rejection, and nondiabetic kidney disease were significant predictors of
failure (P = .01 for all). In addition, the calculated creatinine clearance at 1
year had an adjusted rate ratio (RR) for allograft failure per 10 mL/min (0.17
mL/s) of 0.74 (95% confidence interval [CI], 0.62-0.88). The RR per 10-mm Hg
increase in blood pressure measured at 1 year after transplantation, after
adjustment for creatinine clearance, was 1.15 (95% CI, 1.02-1.30) for systolic
pressure, 1.27 (95% CI, 1.01-1.60) for diastolic pressure, and 1.30 (95% CI, 1.05
1.61) for mean arterial pressure. Supplemental analyses that did not include
death as a failure event or reduce the minimum allograft survival time for study
subjects to 6 months yielded results consistent with the primary analysis. There
was no evidence of modification of the blood pressure-allograft failure
relationship by ethnicity or diabetes mellitus. CONCLUSIONS: Systolic, diastolic,
and mean arterial blood pressures at 1 year posttransplantation strongly predict
allograft survival adjusted for baseline renal function. More aggressive control
of blood pressure may prolong cadaveric allograft survival.
PMID- 10665704
TI - The role of clinical suspicion in evaluating a new diagnostic test for active
tuberculosis: results of a multicenter prospective trial.
AB - CONTEXT: In laboratory trials, nucleic acid amplification tests for the diagnosis
of tuberculosis (TB) are more accurate than acid-fast bacilli (AFB) smear
microscopy and are faster than culture. The impact of these tests on clinical
diagnosis is not known. OBJECTIVE: To assess the performance of a nucleic acid
amplification test, the enhanced Mycobacterium tuberculosis Direct (E-MTD) test,
against a uniform clinical standard stratified by level of clinical suspicion.
DESIGN: Prospective multicenter trial conducted between February and December
1996, documenting the clinical suspicion of TB at enrollment and using final
comprehensive diagnosis as the criterion standard. SETTING: Six urban medical
centers and 1 public health TB clinic. PATIENTS: A total of 338 patients with
symptoms and signs consistent with active pulmonary TB and complete clinical
diagnosis were stratified by the clinical investigators to be at low (< or =25%),
intermediate (26%-75%), or high (>75%) relative risk of having TB. MAIN OUTCOME
MEASURES: Sensitivity, specificity, and positive and negative predictive values
of the E-MTD test in clinical suspicion of groups with low (n = 224);
intermediate (n = 68); and high (n = 46) clinical suspicion of TB. RESULTS: Based
on comprehensive clinical diagnosis, sensitivity of the E-MTD test was 83%, 75%,
and 87% for low, intermediate, and high clinical suspicion of TB, respectively,
and corresponding specificity was 97%, 100%, and 100% (P = .25). Positive
predictive value of the E-MTD test was 59% (low), 100% (intermediate), and 100%
(high) compared with 36% (low), 30% (intermediate), and 94% (high) for AFB smear.
Corresponding negative predictive values were 99%, 91%, and 55% [corrected] (E
MTD test) vs 96%, 71%, and 37% (AFB smear). CONCLUSIONS: For complex diagnostic
problems like TB, clinical risk assessments can provide important information
regarding predictive values more likely to be experienced in clinical practice.
For this series, a clinical suspicion of TB was helpful in targeting areas of the
clinical spectrum in which nucleic acid amplification tests can make an important
contribution.
PMID- 10665705
TI - Sex differences in evaluation and outcome of unstable angina.
AB - CONTEXT: The existence of sex bias in the delivery of cardiac care is
controversial, and little is known about the association between sex and delivery
of care and outcomes at an early point in the diagnostic sequence, such as when
patients present for the evaluation of chest pain. OBJECTIVE: To test the
hypothesis that female sex is negatively associated with care delivered to and
outcomes of persons diagnosed as having unstable angina. DESIGN: Inception
population-based cohort study with an average of 6 years of follow-up. SETTING:
Emergency departments (EDs) in Olmsted County, Minnesota. PATIENTS: A total of
2271 Olmsted County residents (1306 men and 965 women) who presented to the ED
for the first time with symptoms meeting criteria for unstable angina between
1985 and 1992. MAIN OUTCOME MEASURES: Use of cardiac procedures within 90 days of
ED visit, overall mortality, and cardiac events (cardiac death, nonfatal
myocardial infarction, nonfatal cardiac arrest, and congestive heart failure),
compared by sex and Agency for Health Care Policy and Research cardiovascular
risk category (low, intermediate, or high). RESULTS: Women were older (P<.001),
more likely to have a history of hypertension (P = .001), and less likely to
present with typical angina (P = .004) than men. Men were more likely than women
to undergo noninvasive cardiac tests (relative risk [RR], 1.27; 95% confidence
interval [CI], 1.14-1.40) as well as invasive cardiac procedures (RR, 1.72; 95%
CI, 1.51-1.97). After adjustment, male sex was associated with a 24% increase in
the use of cardiac procedures. Survival of both men and women in the high and
intermediate risk categories was significantly lower than expected per the
general population (P<.001). Women had a worse outcome than men, but after
multivariate adjustment, male sex was associated with a trend toward an increase
in the risk of death (RR, 1.23; 95% CI, 0.99-1.54) and significantly associated
with increased risk of cardiac events (RR, 1.21; 95% CI, 1.03-1.42). CONCLUSIONS:
Our population-based data indicate that after an ED visit for symptoms of
unstable angina, the use of cardiac procedures was lower in women, but after
taking into account baseline characteristics, men experienced worse outcomes.
PMID- 10665706
TI - Cytomegalovirus retinitis in the era of highly active antiretroviral therapy.
AB - A number of striking changes have occurred recently in the presentation and
course of cytomegalovirus (CMV) retinitis in patients with acquired
immunodeficiency syndrome (AIDS) who are receiving highly active antiretroviral
therapy (HAART). Before the use of HAART, CMV retinitis was the most common
intraocular infection in patients with AIDS, occurring in up to 40% of patients,
typically when CD4+ cell counts have decreased to less than 0.10 x 10(9)/L. By
studying CMV retinitis, clinicians can investigate whether the rejuvenated immune
system that results from HAART can effectively control opportunistic infections
in patients with AIDS. In some patients, retinitis has not progressed when
specific anti-CMV therapy was discontinued, but a number of patients have
developed substantial intraocular inflammation, which has resulted in decreased
visual acuity. Anterior uveitis, cataract, vitritis, cystoid macular edema,
epiretinal membrane, and disc edema may occur in patients with CMV retinitis who
have experienced HAART-associated elevation in CD4+ cell counts. Since immune
recovery uveitis does not occur in eyes without CMV retinitis, the ocular
inflammation appears to be related to the CMV infection. Anti-CMV maintenance
therapy likely can be safely discontinued in some patients with CMV retinitis if
CD4+ cell counts are stable or increasing and have been higher than 0.10 x
10(9)/L for at least 3 months. Immune recovery in patients receiving HAART has
been effective in controlling opportunistic infections, but it may also result in
intraocular inflammation, which can have adverse effects on the eye.
PMID- 10665707
TI - Long-term outcomes and management of patients with Lyme disease.
PMID- 10665708
TI - Sex bias in cardiovascular care: should women be treated more like men?
PMID- 10665709
TI - The feminization of medicine.
PMID- 10665710
TI - Critical women's health issues in the 21st century.
PMID- 10665712
TI - Why aren't there more women surgeons?. Interview by Valerie A. Jones.
PMID- 10665711
TI - Saints and sinners: women and the practice of medicine throughout the ages.
PMID- 10665713
TI - Encouraging the advancement of women.
PMID- 10665714
TI - JAMA Patient Page: Lyme disease.
PMID- 10665715
TI - A manuscript worth a villa: Vittorio Putti's acquisition of the Guy de Chauliac
manuscript.
PMID- 10665716
TI - Clinical course in synovial sarcoma: a Scandinavian sarcoma group study of 104
patients.
AB - We analyzed treatment and outcome in 104 Scandinavian patients with synovial
sarcoma in the extremities or trunk wall, diagnosed between 1986 and 1994. Only
surgically treated patients without metastases at diagnosis were included. Median
follow-up of survivors was 6 (3-11) years. 34 patients developed metastases. The
overall 5- and 7-year survival rates were 0.76 (95% CI 0.66-0.83) and 0.69 (0.58
0.78), respectively. Large tumor size and amputation were significantly
associated with impaired metastasis-free survival. Patients with local recurrence
had a higher risk of metastases following the local event. Local excision with
inadequate margin was associated with a higher risk of local recurrence.
PMID- 10665717
TI - Synovial sarcoma--identification of favorable and unfavorable histologic types: a
Scandinavian sarcoma group study of 104 cases.
AB - Synovial sarcoma has traditionally been regarded as a high-grade sarcoma and
treated as such. Recently, specific types of poorly differentiated synovial
sarcoma have been defined and shown to affect prognosis adversely. We studied 104
primary synovial sarcomas of the extremities and trunk wall without metastasis at
diagnosis that were retrieved from the Scandinavian Sarcoma Group Registry (SSG)
and the Swedish Cancer Registry from 1986 to 1994. Follow-up was available in all
patients, median 6 (3-11) years for the survivors. There were local recurrences
in 15% of patients and metastases in 33%. Histologically, the tumors were divided
into favorable and unfavorable types. The favorable type had no significant
cytologic atypia, and in most instances, no necrosis and a mitotic count of <
10/10 hpf. The unfavorable type included so-called poorly differentiated synovial
sarcomas as well as recognizable biphasic and monophasic synovial sarcomas with
prominent nuclear atypia, extreme cellularity and nuclear crowding. Designation
of a tumor as having favorable vs. unfavorable histology conveyed more prognostic
information than any single histologic factor. Kaplan-Meier estimates of
metastasis-free survival at 5 years were 83% for patients with histologically
favorable tumors and 31% for patients with histologically unfavorable tumors (95%
confidence intervals 72-92% and 13-51%, respectively). These findings may
influence future treatment protocols for synovial sarcoma.
PMID- 10665718
TI - Incomplete incorporation of morselized and impacted autologous bone graft: a
histological study in 4 intracorporally grafted lumbar fractures.
AB - Morselized and impacted bone allografts are used successfully in hip and knee
revisions, but experiments using bone chambers indicate that impaction actually
can delay ingrowth of new bone into a graft. To understand the remodeling and
incorporation process of morselized and impacted grafts, we studied the
incorporation of morselized impacted autografts in lumbar fractures
histologically. 4 patients were operated on for Th XII-LI fractures. The
fractures were stabilized by VSP plates and transpedicular screws in the
vertebrae above and below the fractured one. Autologous bone graft was packed
into the fractured vertebral body through one of the pedicles. After 18-20
months, the plates were removed and biopsies were obtained from various locations
in the fractured vertebra. All fractures were at this time clinically and
radiographically healed. Histologically, in all cases, large areas of the
autograft in the vertebral body were unvascularized and partially or entirely
necrotic. As with morselized bone in hip revisions, evaluation of graft
incorporation requires histological examination. Full osseous incorporation of a
graft is not always necessary for a good clinical result.
PMID- 10665719
TI - OP-1 for cervical spine fusion: bridging bone in only 1 of 4 rheumatoid patients
but prednisolone did not inhibit bone induction in rats.
AB - We used OP-1 (also called BMP-7) on a collagen type-1 carrier in atlanto-axial
posterior fusions to promote bony healing after wire fixation. 4 patients who had
instability between the atlas and axis due to rheumatoid disease received the
implants. The patients were examined with conventional radiography
postoperatively at 2, 6 and 10 months. In 3 patients, no new bone formation was
detectable. In 1 patient, new bone bridged the fusion site at 6 months. 3
patients were on chronic steroid treatment, including the patient in whom bone
formation was detected. To determine whether steroid treatment could be
responsible for the low rate of bone induction, 24 rats each received OP-1
implants in an abdominal muscle pouch. They were divided into 3 groups receiving
saline, 0.1 or 1.0 mg/kg BW of prednisolone daily until they were killed 3 weeks
postoperatively. Specimens were decalcified for histology and the amount of
calcium in the decalcifying solution was measured. All groups showed ossicles
induced by OP-1, and no effect of prednisolone was detected. Thus the failures in
the patients may have causes other than prednisolone treatment.
PMID- 10665720
TI - Total elbow arthroplasty in rheumatoid arthritis: 20 GSBIII prostheses followed 2
5 years.
AB - From 1993 to 1996, we implanted 20 primary GSB IlI prostheses in 17 patients with
rheumatoid arthritis. The Mayo Clinic performance index for the elbow was used
for the evaluation. The average follow-up was 3 (2-5) years. At the follow-up
examination, 12 elbows had an excellent result and 8 a good result. The median
performance index increased from 30 (15-53) points to 95 (80-100) points. The
subjective assessment was excellent for 11 elbows, good for 8 and poor for 1.2
elbows had radiographic loosening with a progressive radiolucent line and a
change in the orientation of the prosthesis.
PMID- 10665721
TI - Increased migration of the SHP prosthesis: radiostereometric comparison with the
Lubinus SP2 design in 40 cases.
AB - 40 patients with primary arthrosis were randomized to receive either a cemented
SHP (Scientific Hip Prosthesis) or Lubinus SP2 prosthesis. At 2 years
radiostereometric measurements showed increased proximal migration (0.4/0.2 mm; p
= 0.02) and more proximal wear (0.3/0.1 mm, p = 0.01) of the SHP socket. The SHP
stem also subsided (-O.6/-0.1 mm, p<0.001) and rotated more into retroversion
(2.6/0.3 degrees ) than did the SP2 design. This subsidence mainly occurred
inside the cement mantle in 17 of 18 cases (13 SHP, 4 SP2), where this type of
motion could be measured. The changes in bone mineral density evaluated with DEXA
and the clinical results did not differ between the 2 groups. The subsidence of
the SHP stem is the most pronounced so far recorded with radiostereometry in
stems without a completely polished surface. This subsidence and the rotational
instability imply a substantial risk of abrasive wear and increased stresses in
the cement mantle.
PMID- 10665722
TI - Metal-on-metal bearing in hip prosthesis generates 100-fold less wear debris than
metal-on-polyethylene.
AB - Aseptic loosening due to osteolysis in total hip replacement has been related to
wear debris released from prosthetic components. Retrospective longterm
observations of patients with the metal-on-metal prosthesis has shown long-term
survivorship and good mechanical performance. Thus, the new and modified metal-on
metal prosthesis has been introduced on the market. Historical clinical data from
the 1st generation metal-on-metal hip prosthesis may not be relevant for the 2nd
generation of metal-on-metal hip prosthesis. Therefore, preclinical testing of
the prosthesis must be conducted before clinical evaluation. We assessed the
tribological performance of the metal-on-metal prosthesis versus the metal-on
polyethylene prosthesis introduced on the market as Metasul and Protasul,
respectively. In a 12-channel joint simulator, 6 metal-on-metal bearing and 3
metal on polyethylene prostheses were tested, with the same number of
corresponding soak controls. The wear was assessed gravimetrically. The "steady
state" wear-rates from the metal-on-metal prosthesis were almost 100 times less
than that from the metal-on-polyethylene prosthesis. The tribological wear
performance of the metal-on-metal hip prosthetic system is promising.
PMID- 10665723
TI - Acetabular coverage of the femoral head after triple pelvic osteotomy: no
relation to outcome in 51 hips followed for 8-15 years.
AB - In developmental dysplasia of the hip in adolescents and young adults, pelvic
osteotomies aim to improve acetabular coverage of the femoral head by reorienting
the acetabulum. We determined whether acetabular coverage is related to long-term
clinical results after triple osteotomy of the pelvis. We used a previously
published computer program (Konishi and Mieno 1993) which calculates three
dimensional coverage of the femoral head from plain anteroposterior radiographs.
We studied the pelvic radiographs of 51 hips in 43 patients and the results were
correlated with studies on clinical outcome (de Kleuver et al. 1997). Total
acetabular coverage improved from a mean of 56% to 70%. We did not find a
relationship between total acetabular coverage and long-term outcome, nor could
we determine an optimal coverage. Reduced coverage of the posterolateral quadrant
of the femoral head was related to a reduced score for walking ability (p =
0.03), and therefore care should be taken not to overcorrect the acetabulum
forwards when attempting to improve the deficient anterior coverage. We challenge
the concept that total acetabular coverage is a prerequisite for a good long-term
outcome after triple pelvic osteotomy, and hypothesize that other factors such as
the change in load across the hip are probably more important in determining the
outcome.
PMID- 10665724
TI - Fluid flow around model femoral components of differing surface finishes: in
vitro investigations.
AB - We studied fluid flow at the stem-cement interface of bonded and debonded,
polished and rough model femoral components. In a first series of experiments,
fluid flow along the interface between bone cement and well-fixed model femoral
components, differing in surface finish, and in shape, was measured. Fluid
migration along the bone-cement interface of rough stems (Ra 3 microm) was
greater than that on polished stems (p < 0.001). This was true of cylindrical and
conical tapered stems. On stems with the same surface finish, shape did not
influence fluid migration. In a second series of experiments, fluid flow along
the stem-cement interface of 5 highly polished and 10 rough-finished (5 of Ra
approximately 1.5 microm and 5 of Ra approximately 3 microm), debonded, tapered
circular stems was measured. None of the rough stems could prevent fluid flow
along the stem-cement interface. Polished tapered stems sealed the interface and,
after 48 hrs of continuous pressure, no fluid flow was observed. This difference
in the ability to seal the stem-cement interface between rough and polished stems
was significant (p < 0.001). The difference in fluid migration along the stem
cement interface of rough and polished stems which we observed offers a plausible
explanation of the occurrence of osteolysis distal to the articulation of
cemented THR in the presence of cement mantle defects. It may also explain why
osteolysis is uncommon with polished double-tapered stems.
PMID- 10665725
TI - Incomplete cement mantles in the sagittal femoral plane: an anatomical
explanation.
AB - The influence of operative technique on the formation of incomplete cement
mantles in the sagittal plane has been rarely considered in the literature. In
this article, we discuss the influence of the anatomy of the proximal femur on
the formation of incomplete cement mantles and discuss how their incidence can be
reduced by correct component positioning.
PMID- 10665726
TI - Open reduction of late unreduced traumatic posterior hip dislocation in 12
children.
AB - We present 12 children with late unreduced traumatic posterior dislocation of the
hip. All had posterior dislocation and no associated fracture. The dislocation
had remained unreduced for a mean period of 20 (6-52) weeks. Open reduction was
done in all cases, since none of the hips could be reduced with upper tibial
skeletal traction in abduction. All the hips showed varying degrees of avascular
necrosis, with preservation of joint space on roentgenograms. 11 children had an
excellent outcome, according to the criteria of Garrett et al. (1979), after a
follow-up of mean 26 (24-36) months. We suggest that open reduction is a
satisfactory treatment for hip dislocation of any duration in children.
PMID- 10665727
TI - Bone mineral and migratory patterns in uncemented total knee arthroplasties: a
randomized 5-year follow-up study of 38 knees.
AB - We measured the amount of bone mineral in the medial tibial condyle 1 week
postoperatively, after 1 year and after 4-5 years in 38 arthrotic knees
randomized to a Freeman-Samuelson hydroxyapatite-coated (FS HA) or a Miller
Galante II (MG II) total knee arthroplasty. Clinically excellent results were
recorded in both groups after 5 years. At the last follow-up, the overall
decrease in bone mineral was 26%, as measured by triple-energy X-ray
absorptiometry. The decrease was larger in FS HA knees than in MG II knees after
4-5 years, indicating stress-shielding of the proximal tibia. Radiostereometry at
1 and 5 years showed smaller maximum total point motion, maximum subsidence and
varus or valgus tilt in the FS HA group. There was a tendency towards a reversed
relationship between subsidence and change in bone mineral after 1 year, but not
after 4-5 years. Distal fixation of the stem in the Freeman-Samuelson
hydroxyapatite-coated (FS HA) components might explain the more pronounced loss
of bone mineral in the medial tibial condyle.
PMID- 10665728
TI - Cancer incidence after total knee arthroplasty: a nationwide Finnish cohort from
1980 to 1996 involving 9,444 patients.
AB - A nationwide, computer-based survey of all total joint arthroplasties performed
in Finland has been carried out since January 1980. From these records, a cohort
of 9,444 patients, with 51,756 person-years, after primary operation with a total
polyethylene-on-metal knee arthroplasty (TKA) was followed up for cancer through
the Finnish Cancer Register up to December 31, 1996. During the follow-up, 706
cancers were observed. The expected number, based on national rates, was 719;
therefore, the standardized incidence ratio (SIR) for all cancers was 0.98. The
SIRs for non-Hodgkin's lymphoma (1.40), Hodgkin's disease (1.24) and multiple
myeloma (1.54) were increased, but only that of non-Hodgkin's lymphoma was
statistically significant 3-10 years after the operation. The numbers of observed
cases of prostate cancer exceeded that of expected, with a SIR value of 1.49. A
low SIR of lung cancer was observed among men, especially during the first 3
years (0.61), but not in women. The SIR for colon cancer was below unity in women
only (SIR 0.70). The SIR for cancer of the urinary organs was close to unity
(0.97). SIR relating to soft tissue and bone cancer did not differ significantly
from unity, and none of the 6 sarcomas was observed at the site of a prosthesis.
The overall cancer risk after TKA done for primary osteoarthrosis seems not to be
increased. The increases in lymphoma and prostate cancer risk, however, are
observations that could be related to TKA and justify further follow-up of the
cohort.
PMID- 10665729
TI - Tibialis posterior tendon abnormalities in feet with accessory navicular bone and
flatfoot.
AB - To assess tibialis posterior tendon (TPT) pathology, we investigated 27 feet with
the accessory navicular bone and 22 normal feet by MRI. We found two major
anatomical differences in the feet with the accessory navicular bone; the TPT
directly inserted in the accessory navicular bone, without any continuity to the
sole of the foot or with a slip, less than 1 mm in thickness, and there was a
mass with the density of fibrocartilage tissue, between the tendon and the bone
in 20/27 feet. These abnormalities were not detected in the control group. 3
patients in the study group were operated on and the MRI findings were confirmed.
These findings suggest that patients with the accessory navicular bone and
flatfoot should be examined by MRI for insertion abnormalities of the TPT.
PMID- 10665730
TI - Decreasing incidence of fractures in children: an epidemiological analysis of
1,673 fractures in Malmo, Sweden, 1993-1994.
AB - The incidence of fractures in children in the city of Malmo, Sweden, almost
doubled between 1950 and 1979. To see whether a further increase had occurred, we
carried out an epidemiological analysis of fractures among children 0-16 years in
Malmo 1993-1994. During the study period, 1,673 fractures occurred in 1,610
children. The commonest fracture location was the distal forearm (26%), followed
by the phalanges of the hand (16%) and the clavicle (9%). The annual fracture
incidence was 235/10(4) in boys, 149/10(4) in girls and 193/10(4) for both
genders. This means a decrease in the annual fracture incidence by 9% since 1975
1979. The decrease was not associated with any specific type of fracture or
etiological factor. Fractures of the distal forearm among girls were an exception
to the general decline, having increased by one third since 1975-1979, which
might be explained by the fact that today girls participate to a greater extent
in the same sports as boys.
PMID- 10665731
TI - Synovial chondromatosis of the wrist and hand--a case report.
PMID- 10665732
TI - Accidental Salmonella enteritidis vaccine injection leading to finger necrosis--a
report of 4 cases.
PMID- 10665733
TI - The role of prophylactic pinning in the treatment of slipped capital femoral
epiphysis--a case report.
PMID- 10665734
TI - Irreducible fracture-separation of the distal ulnar epiphysis in the Galeazzi
equivalent fracture--a case report.
PMID- 10665735
TI - Tuberculosis of talus and cuboid--a report of 2 children.
PMID- 10665736
TI - Classification and diagnosis of seronegative spondyloarthropathies.
PMID- 10665737
TI - Classification and diagnosis of seronegative spondylarthropathies--comments.
PMID- 10665738
TI - The prevalence of rheumatoid arthritis in Sweden.
AB - The aim of this study was to ascertain the prevalence of rheumatoid arthritis
(RA) in a Swedish general adult population. A questionnaire about chronic pain
was mailed to a total of 3928 subjects who were chosen as a random sample of the
population in two communities in the county of Halland. All persons answering
affirmatively to questions intended to identify patients with RA were invited to
a clinical examination. X-rays of hands and feet, and analyses of rheumatoid
factor and C reactive protein were performed provided that the patients fulfilled
two or more of the five clinical items of the 1987 ARA criteria. Furthermore, non
participants were searched for in a patient register and in medical records from
the local rheumatology unit in an attempt to identify further cases. Using the
modified 1987 ARA criteria for population studies the prevalence rate of RA was
calculated to 0.51% (95%, CI = 0.31-0.79).
PMID- 10665739
TI - Anticardiolipin and anti-beta2GPI antibodies in a large series of European
patients with systemic lupus erythematosus. Prevalence and clinical associations.
European Concerted Action on the Immunogenetics of SLE.
AB - OBJECTIVE: To test the prevalences and the clinical associations of
anticardiolipin (aCL) and anti-beta2GPI (abeta2GPI) antibodies in a large series
of European patients with systemic lupus erythematosus (SLE). METHODS: 574 SLE
patients from 7 European countries were tested for aCL and abeta2GPI by ELISA
methods. RESULTS: aCL of IgG, IgM, and IgA isotypes were detected in 22.8%, 14%,
and 13.9% of the patients, respectively. IgG and IgM abeta2GPI were detected in
20% of the patients. The presence of aCL was highly associated with the presence
of abeta2GPI. Medium-high titer IgG aCL and abeta2GPI were associated with
thrombosis, with similar sensitivity, specificity, and positive predictive value.
When present at medium-high titer, IgG aCL were associated with thrombocytopenia,
IgM aCL with hemolytic anemia, and cerebrovascular accidents. IgA aCL with livedo
reticularis and Raynaud's phenomenon. CONCLUSIONS: aCL, when present at medium
high titer, are as important as abeta2GPI, as a risk factor for thrombosis.
Medium-high titer aCL, but not abeta2GPI, are associated with other clinical
features of the antiphospholipid syndrome.
PMID- 10665740
TI - Perinatal outcome in pregnancies of women with connective tissue disease and
inflammatory rheumatic disease in Norway.
AB - Perinatal outcome in infants of women with rheumatic disease notified between
1967 95 to the Medical Birth Registry of Norway was compared to women without
such disease. Logistic regression provided odds ratios for associations between
rheumatic disease and perinatal outcome for 3 time periods: 1967-76, 1977-86, and
1987-95. Women with rheumatic disease had significantly higher rates of preterm
birth than references and this was only partly correlated to the increased
occurrence of preeclampsia. The risk of small for gestational age (SGA) infants
was significantly higher both in women with connective tissue disease (CTD) and
inflammatory arthritides. The proportion of infants with Apgar score < = 6 after
1 minute and 5 minutes was significantly increased in the CTD group indicating
moderate to severe fetal asfyxia. The rate of perinatal mortality was high in the
CTD group and postperinatal mortality was increased in infants born to mothers
with rheumatic disease. Thus, rheumatic disease not only comprises pregnancy
outcome, but increases the risk of adverse perinatal outcome.
PMID- 10665741
TI - Do flares of systemic lupus erythematosus decline after menopause?
AB - OBJECTIVE: To study whether flares of SLE decline after menopause. METHOD: 34
postmenopausal SLE patients with premenopausal disease onset were studied. The
frequency and severity of flares before and after menopause was compared. 17
postmenopausal onset SLE patients were also included for comparison. RESULT:
Flares in postmenopausal SLE patients decreased significantly after menopause
(total No. of flares/patient-year before and after menopause were 0.50+/-0.10 and
0.14+/-0.05, respectively, p = 0.002). The frequency and proportion of severe
flares also dropped significantly. The rate and magnitude of postmenopausal
flares in these patients were similar to those of the postmenopausal onset SLE
patients, a subset known to run a more benign course. CONCLUSIONS: SLE flares
less frequently and seriously after menopause. While this may suggest a
protective role of hypoestrogenemia against lupus flares, the contribution of
other factors like disease duration and effective treatment to this
postmenopausal decline of flares cannot be separated from menopause per se.
Further studies are needed.
PMID- 10665742
TI - Bone mineral density of the lumbar spine in patients with advanced rheumatoid
arthritis. Influence of functional capacity and corticosteroid use.
AB - We investigated factors that are related to generalized osteoporosis in advanced
rheumatoid arthritis (RA). In this cross-sectional study we measured trabecular
bone mineral density (BMD), by quantitative computerized tomography (QCT), in the
lumbar spine of 57 patients with RA, most of whom were premenopausal women. In
our material, 27 out of 57 patients (47%) had BMD <-1 SD expressed as Z-score and
five patients had suffered from fractures. Our study shows that a cumulative
corticosteroid dose (r = -0.41, p<0.010) and functional impairment (r = -0.37,
p<0.050) were negatively related to spinal BMD, while daily intake of calcium
correlated positively on BMD (r = 0.37, p<0.010). Our results indicate that low
BMD is common in patients with advanced RA and it is associated with long-term
corticosteroid use. Thus, in clinical practice we have to consider the benefits
and harms of corticosteroid treatment and preventive therapy to osteoporosis.
PMID- 10665743
TI - Prolactin, growth hormone, and IGF-1 in ankles and plasma of adjuvant arthritic
rats.
AB - In this study we have investigated the levels of prolactin, growth hormone, and
insulin-like growth factor-1 in plasma and in tissue extracts of ankle joints of
rats with acute or chronic adjuvant arthritis using enzyme immunoassay (EIA) and
radioimmunoassay (RIA). We found a stable content of prolactin in plasma of the
different groups but a significantly increased concentration of growth hormone
was observed in the plasma of the group with chronic arthritis. Moreover, an
increased concentration of insulin-like growth factor-1 was noted in the plasma
of the acute group. This evidently had returned to normal levels in the chronic
group. In contrast, decreased concentrations of prolactin, growth hormone, and
insulin-like growth factor-1 were found in tissue extracts of ankle joints of the
group with chronic arthritis. The changes in the levels of these hormones in
adjuvant arthritis might suggest that they play a role in the pathogenesis of the
disease. Understanding the mechanism(s) of hormonal participation in adjuvant
arthritis may open new treatment strategies for rheumatoid arthritis and other
inflammatory disorders.
PMID- 10665744
TI - Color duplex ultrasonography in large-vessel giant cell arteritis.
AB - In a patient with active extracranial giant cell arteritis, duplex
ultrasonography demonstrated hypoechoic mural thickening of the brachial,
axillary, subclavian, and carotid arteries with bilateral subtotal occlusions of
the brachial and axillary arteries. The ultrasound image of the artery walls
became midechoic within 8 weeks, and hyperechoic within one year after start of
treatment with corticosteroids. A similar hypoechoic mural thickening of the
temporal arteries has been recently described in active giant cell arteritis. The
dark ultrasound image is due to an edema of the vessel wall in the acute stage.
The brighter ultrasound image might be due to fibrosis in the chronic stage of
the disease.
PMID- 10665745
TI - AV-block III in a patient with sarcoidosis mimicking Sjogren's syndrome.
AB - A 55-year old woman with a diagnosis of primary Sjogren's Syndrome suddenly
developed AV-block III. A diagnostic procedure finally revealed sarcoidosis with
multiorgan involvement.
PMID- 10665746
TI - Tuberculosis of skeletal muscle in a case of polymyositis.
AB - We describe a patient with polymyositis receiving corticosteroid therapy, who
presented with persistent fever and mass lesion at the left thigh. Surgical
exploration and mycobacterial culture proved to be Mycobacterium Tuberculosis
infection involving the semitendinous muscle of the left thigh. Suitable surgical
debridement, anti-TB medications, and sufficient corticosteroid administration
resulted in a good control of both polymyositis and the tuberculous infection.
PMID- 10665748
TI - Correction for covariates.
PMID- 10665747
TI - Elevated plasma levels of transforming growth factor beta 1 in patients with
aseptic loosening of total hip arthroplasties.
PMID- 10665749
TI - Is there a role for fractionated radiotherapy in the treatment of arteriovenous
malformations?
AB - Single fraction radiotherapy for the treatment of arteriovenous malformations
(AVMs) is appropriate when brain tolerance is not a limiting factor, but when
tolerance is a concern, there is a potential for therapeutic gain with
fractionated treatment. alpha/beta values for AVM obliteration have been derived
and found to be higher than previously assumed and are likely to be approximately
10.0 Gy or more compared with approximately 1.5 Gy for the tolerance of small
volumes of brain. Models are derived to describe, qualitatively, the potential
gain that can be achieved with fractionation. Past experience has identified an
important volume effect that has limited the use of stereotactic treatments to
small volumes. Volume-dependent, dose-volume relationships are described,
including a tissue-specific volume exponent (phi) which was found to apply across
a relatively wide range of target volumes, thereby permitting the derivation of
tolerance guidelines to volumes larger than previously available. More data to
define parameter values more precisely are desirable.
PMID- 10665750
TI - Smoking and survival from lung cancer.
AB - The role of smoking in the etiology of lung cancer is well known but less is
known about whether smoking also affects the pathological process. In the present
analysis 290 lung cancer patients were divided into three equal-sized groups
according to lifetime cigarette consumption (heavy, moderate, light/none). The
age of the patient, histology, TNM and S-phase fraction of the tumor were
confirmed as prognostic factors. The association between smoking and these
factors was evaluated. There was a significant difference in histological type of
tumor; adenocarcinomas were more common than other types among light smokers.
Tumor size, nodal status and occurrence of distant metastases did not differ
significantly between the smoking groups. Heavy smokers had a greater frequency
of aneuploid tumors and the S-phase fraction was higher among these patients but
neither of these differences was statistically significant. Survival analysis
indicated no statistically significant association between survival and lifetime
total cigarette consumption. Apart from histological type, smoking is not
materially associated with clinical and biological prognostic factors, nor does
smoking materially affect the survival of lung cancer patients. Our study
material was relatively small and therefore not of sufficient power to detect
small effects.
PMID- 10665751
TI - Metastatic pattern in non-resectable non-small cell lung cancer.
AB - This study describes the metastatic pattern at autopsy in patients with non
resectable non-small cell lung cancer (NSCLC) and evaluates the impact of various
pretreatment variables and treatment outcomes on the metastatic spread. In eight
phase II chemotherapy trials from 1985 through 1993, 337 patients were treated
and 51 autopsies were performed (autopsy rate 15%). The male/female ratio was
31/20, median age 56 years (range 36-71), response rate to chemotherapy 8%, and
median survival 88 days (range 3-899). Histologic types included adenocarcinoma,
31 cases (60%), squamous cell carcinoma, 9 cases (18%), large cell carcinoma, 9
cases (18%), and unclassified NSCLC, 2 cases (4%). Patients who were autopsied
had a shorter median survival than patients without autopsy (p = 0.002, log-rank
test). Most commonly involved metastatic sites found at autopsy were mediastinal
lymph nodes (84%), pleura (51%), liver (47%), bone (34%), brain (32%),
pericardium (29%), adrenals (29%). The median number of involved organs was 5
(range 1-16), with a median of 3 intrathoracic sites (range 1-8) and 2
extrathoracic sites (range 0-11). Patients who initially had metastatic NSCLC
also had significantly more metastatic sites at autopsy both extrathoracic (p =
0.004) and totally (p = 0.03) compared to patients with locally advanced disease.
No other relation to pretreatment variables was found.
PMID- 10665752
TI - Endobronchial radiotherapy for malignant bronchial obstruction or recurrence.
AB - Forty-five lung cancer patients who had recurrence and/or endobronchial
obstruction were treated with intrabronchial radiotherapy (IBRT). The majority
had been heavily treated previously, mainly by external radiotherapy; six
patients were treated surgically. IBRT was given with high-dose-rate equipment,
either 18 Gy in three fractions or 15 Gy as a single dose was originally planned.
For different reasons several patients received other regimens. Palliation of
dyspnoea was obtained in 64% of the patients. Palliation of hemoptysis (12/14)
and cough (11/17) was registered, as well as improvement in atelectasis in 11/26
patients. Palliation of dyspnoea was enhanced with an IBRT dose > 15 Gy. The
median survival after IBRT was 13 weeks. Fatal hemoptysis (FH) occurred in 12
patients; 10 of these within 6 months after treatment. The risk of FH
significantly increased with an IBRT dose > 15 Gy.
PMID- 10665753
TI - Induction chemotherapy followed by concurrent chemoradiotherapy in stage III
unresectable non-small cell lung cancer.
AB - The favourable experience with the combination regimen of vinorelbine, ifosfamide
and cisplatin (NIP) in patients with metastatic non-small cell lung cancer
(NSCLC) has led to a protocol assessing this regimen as an induction treatment in
patients with stage III unresectable NSCLC, followed by thoracic radiotherapy
with concurrent daily cisplatin as a radiosensitizer. Two cycles of NIP were
administered 21 days apart; each cycle comprised i.v. vinorelbine 25 mg/m2 on
days 1 and 8, i.v. ifosfamide 3 g/m2 on day 1 with MESNA as uroprotection, and
i.v. cisplatin 50 mg/m2 on day 1. Radical thoracic radiotherapy commenced on day
43 to a total dose of 64 Gy and i.v. cisplatin 6 mg/m2 was given concurrently
prior to each fraction of radiation as a sensitiser. Two more cycles of NIP were
given to patients who responded favourably to the induction treatment about 2
weeks after completion of radiation. Between July 1995 and July 1997, 44 patients
were treated with this protocol. This treatment schedule was generally well
tolerated. Grade 3-4 neutropenia occurred in 50% of the patients and neutropenic
sepsis was seen in 8. Grade 3-4 oesophagitis was uncommon. Most of the patients
were able to complete the induction and concurrent chemoradiotherapy phase. Major
response occurred in 75% of the patients with 2 (4.5%) complete responses (CR). A
total of 6 patients achieved CR after chemoradiotherapy. At a median follow-up of
35 months, the median overall survival for all patients was 15 months with a 3
year survival rate of 24%. The median overall survival for stage IIIA patients
was 19 months with a 3-year survival rate of 39% in contrast to 13 months' median
overall survival and only 15% 3-year survival rate for stage IIIB. The NIP
regimen results in a high response rate in NSCLC and this treatment programme
seems to benefit selected patients with stage III disease.
PMID- 10665754
TI - Factors influencing the distribution of metastases and survival in extensive
disease small cell lung cancer.
AB - This study was conducted to investigate the distribution of metastatic lesions
and their influence on survival, as well as other prognostic factors previously
shown to have an impact on the outcome of patients with extensive small cell lung
cancer (SCLC). Of the 207 patients were included and retrospectively analyzed;
124 patients had extended disease at initial presentation and the remaining 83
developed metastatic disease during follow-up. Patients who relapsed presented
most frequently with distant metastases. The brain was the most frequent organ
targeted for metastatic disease following the completion of chemotherapy
(p<0.05). Serum LDH levels correlated significantly with the presence of liver
metastasis (p<0.001). The site of involvement did not seem to have an impact on
survival. Nevertheless, patients with multiple metastatic sites had a
significantly poor survival rate (p = 0.001). Weight loss, performance status,
gender, clinical stage, serum LDH and albumin levels were all shown to correlate
with survival (p<0.05). Response to chemotherapy was determined to be the most
important prognostic factor.
PMID- 10665755
TI - Vincristine (Vinca-alkaloid) as a sclerosing agent for malignant pleural
effusions.
AB - Vincristine, extracted from Vinca rosea Linn., is an effective antineoplastic
chemotherapeutic drug used in oncology practice. This drug has never been used as
a sclerosing agent for the treatment of malignant pleural effusion for reasons
unknown. A study was conducted to examine the use of Vinca-Alkaloid as a
sclerosing agent (pleurodesis) for the palliative treatment of malignant pleural
effusions. The study included 15 patients, all diagnosed to have cytology-proven
malignant pleural effusions. Intercostal tube drainage followed by chemical
sclerotherapy with 2 mg vincristine was performed on all patients and a high
success rate was noted. Twelve procedures out of 15 (12/15) achieved complete
resolution of pleural fluid with a success rate of 80%. In two procedures the
pleural effusion was reduced and then recurred but did not require re-aspiration.
One procedure failed and repeated pleural aspiration was required. In this study,
with adequate pleural drainage and the proper technique, vincristine was found to
be an effective sclerosing agent for malignant pleural effusion. Further
randomized trials are necessary in order to establish the role of this drug.
PMID- 10665756
TI - Cancer of the mobile tongue in Finland--increasing incidence, but improved
survival.
AB - A population-based descriptive study was conducted to describe incidence and
survival of cancer of the mobile tongue in Finland between 1953 and 1994. The
study included 1504 patients, drawn from the Finnish Cancer Registry, with first
primary mobile tongue cancer diagnosed between 1953 and 1994. Incidence and
relative survival were determined. The age-standardized overall incidence rate
was 0.6 per 100000 years in 1953-1994. At the time of diagnosis 78% of the
patients had either localized or regional disease. The age-standardized incidence
rate decreased after the mid-1960s, but increased in the 1990s. The 5-year
relative survival rate increased gradually from 40% in 1953 1959 to 58% in 1988
1994. Disease stage at the time of the diagnosis strongly affected the survival
rate. Survival increased especially in regional disease. Cancer of the mobile
tongue is increasing in Finland, but survival has increased particularly in
regional disease, probably because of improved treatment. Early diagnosis is
emphasized for a good prognosis.
PMID- 10665757
TI - Tumor volume and local control in primary radiotherapy of nasopharyngeal
carcinoma.
AB - An investigation of the effect of tumor volume and total dose on local control
following primary radiotherapy for nasopharyngeal carcinoma was carried out in
order to estimate the radiation dose necessary to control a specific tumor
volume. Between 1983 and 1996 a total of 104 patients underwent radiation therapy
for nasopharyngeal carcinoma at the Department of Radiation Oncology of the
University of Wuerzburg. Total doses of between 8 and 80 Gy (5 fractions per
week) were administered. Complete CT-data on primary tumor size, total tumor dose
(calculated by 3D- or quasi 3D-CT-based radiation planning computer) and on local
control status in the follow-up period were available for 63 patients. Lymph node
metastases were present in 38 of these patients and they were also entered into
the study. Thus this study is based on a total of 101 tumor regions. A Poisson
probability-based model was used for calculating the dose-response relationship.
Assuming a correlation between tumor volume and the total dose necessary to
obtain local control, the individual tumor volumes were rescaled to a 1 ml volume
by introducing a volume-dependent modification factor for the applied dose, in
order to eliminate the influence of different individual tumor volumes. All dose
values given are based on a fractionation scheme of 2 Gy single dose, 5 fractions
per week. Nineteen tumors and 11 lymph nodes were considered locally uncontrolled
or recurrent. Without dose-volume modification, a weak dose-response correlation
was found and a typical shallow dose-response curve was calculated with a 50%
response dose (RD50) of 60.2 Gy and a normalized dose-response gradient (gamma50)
of 3.2+/-0.62. After dose-volume modification and rescaling to a 1 ml tumor
volume, a steep dose-response curve with an RD50 of 40.9 Gy and gamma50 of 8.2.
was found. Tumor volume is a very important factor influencing local control in
nasopharyngeal carcinoma. The rescaling procedure to a reference volume of 1 ml
used in this study revealed a very steep dose-response relationship. This result
suggests that the clinically observed smooth dose-response relationships may be
explained by interindividual tumor volume heterogeneity. The additional dose
necessary to control a tumor of the double volume is close to 5 Gy. With a total
dose of 72 Gy (5x2 Gy/week), tumor volumes larger than 64 ml are unlikely to be
controlled.
PMID- 10665758
TI - Radiation therapy and concurrent cisplatin in management of locoregionally
advanced nasopharyngeal carcinomas.
AB - Radiation therapy in combination with chemotherapy in the management of
locoregionally advanced nasopharyngeal carcinomas is evaluated in an attempt to
improve locoregional response, reduce locoregional failure and reduce systemic
failure. The current study was designed to investigate radiation therapy and
concurrent cisplatin in this context. From 1992 through 1997, 70 patients with
locoregionally advanced nasopharyngeal carcinomas were treated with radiation
therapy and concurrent cisplatin. External beam radiation dose was 60 Gy for T1,
T2 and T3 tumors, 70 Gy for T4 tumors and 70 Gy for metastatic cervical lymph
nodes. An intracavitary brachytherapy boost (10 Gy) was applied for T1, T2 and T3
tumors. Cisplatin (30 mg/m2) was administered weekly during external beam
radiation therapy. Locoregional complete response was achieved in 63 patients,
locoregional failure was observed in 4 patients and systemic failure was observed
in 15. N-stage predicted systemic failure. Overall survival, locoregional failure
free survival and systemic failure-free survival were 63%, 79% and 75%,
respectively, at three years. Grade 3 acute skin toxicity was observed in 2
patients, Grade 3 acute mucous membrane toxicity was observed in 6 and Grade 3
acute hematological toxicity was observed in 2 patients. Despite improved
locoregional response, reduced locoregional failure and improved survival with
radiation therapy and concurrent cisplatin, systemic failure remains prevalent
for locoregionally advanced nasopharyngeal carcinomas.
PMID- 10665759
TI - Changes in oxygen tension during radiotherapy of head and neck tumours.
AB - Increased knowledge about changes that occur in tumour oxygenation during
radiotherapy and the biological factors causing these changes can be useful in
the development of optimal radiation treatments. The aims of this study were a)
to study changes in the oxygen tension (pO2) of human head and neck tumours
during radiotherapy in relationship to changes in cell density and vascular
density, and b) to investigate whether the pO2, measured before or during
therapy, can be used to predict the therapeutic outcome. Preliminary data from
the first 11 patients included in the study are reported. The pO2 was measured
before treatment (11 patients) and once a week during therapy (8 patients), using
polarographic needle electrodes. Cell density and vascular density were
determined from biopsies taken after each pO2 measurement in 5 patients.
Significant fluctuations in pO2 occurred during therapy. Changes in hypoxic
fraction; i.e., fraction of pO2 readings below 2.5 mm Hg, 5 mm Hg or 10 mm Hg,
coincided with changes in cell density, but not with changes in vascular density,
which suggests that the changes in hypoxic fraction were caused by changes in
oxygen consumption rather than supply. Response evaluation after a median follow
up time of 19 months showed that progressive disease occurred among the patients
with highly hypoxic tumour, regardless of whether hypoxic fraction before
treatment or after two weeks of radiotherapy was considered.
PMID- 10665760
TI - Long-term continuous 5-fluorouracil infusion in patients with advanced head and
neck cancer.
AB - Forty-two patients with advanced head and neck cancer entered this phase II trial
of long-term continuous 5-fluorouracil (5-FU) infusion at a dose of 300 mg/m2/day
for a maximum of 16 weeks. Objective response rate was 15% in 41 evaluable
patients. Median time to progression was 2.9 months, and median survival 4
months. Toxicity was generally mild. Reversible stomatic and hand-foot syndrome
WHO grade III-IV was observed in 5 and 3 patients, respectively. Haematologic
toxicity and emesis were less pronounced with no grade III-IV toxicity. One
patient had to discontinue treatment because of ataxia. No catheter-related
toxicity and no treatment-related mortality were observed. In the present study
long-term continuous infusion of 5-FU has only modest activity in terms of
response rate, but the activity is comparable with other single-agent regimens.
The treatment is well tolerated, with minimal toxicity making it usable in a
palliative situation.
PMID- 10665761
TI - Alterations in head and neck cancer occurring in HIV-infected patients--results
of a pilot, longitudinal, prospective study.
AB - To assess the impact of human immunodeficiency virus (HIV) infection on the
presentation and course of head and neck squamous cell carcinoma (HNSCC), we
performed a pilot, prospective, longitudinal study of all patients with HNSCC
presenting to our institutions over a 6-month period (n = 10). A 60% incidence of
HIV infection was seen in this study population, with SCC presenting as the
initial manifestation of HIV infection in 2 of the 6 patients. In addition. HIV
infected patients were significantly younger than non-infected patients at (p =
0.01). None of the HIV-infected patients had acquired immunodeficiency syndrome
(AIDS) at the time of presentation, but 5 of 6 patients had an abnormal CD4
count, compared to none of the non-infected patients (p = 0.05). The absolute CD4
count in HIV-infected patients decreased to less than 100x10(9)/L in the majority
of these patients within 3 months of presentation with HNSCC (p = 0.05).
Treatment-associated complications were common in HIV-infected patients,
occurring in 4 of the 6 cases in contrast to none of the patients without HIV
infection (p = 0.046). Outcome was significantly poorer for HIV-Infected
patients, with 5 patients succumbing to their disease within one year, in
contrast to none of the non-infected patients (p = 0.046). These data, combined
with our previous work, justify further investigation of the relationship between
HNSCC and HIV infection and the possibility of its inclusion as an AIDS-defining
process.
PMID- 10665762
TI - Low-grade astrocytoma--a retrospective analysis of 102 patients.
AB - One hundred and two patients (57 males, 45 females, median age 17 years) with
histologically proven low-grade astrocytoma (grades I, II) treated between 1978
and 1994 were retrospectively analyzed at the King Faisal Specialist Hospital &
Research Center. Microscopic investigation showed 50 patients (48%) with grade I
tumors as opposed to 52 patients (52%) with grade II tumors. Fifteen patients
(15%) had complete surgical excision, 55 (52%) had partial excision and 32 (31%)
had biopsy only; 68 patients (66%) received external radiotherapy with a median
dose of 54 Gy (range 45-68.5 Gy). With a median follow-up of 3.3 years, the 5 and
10 years, overall actuarial survival rates were 78% and 62%, respectively while
the progression-free survival rates at 5 and 10 years were 69%, and 35%,
respectively. Age and performance status were significant prognostic factors in
terms of overall survival on univariate (p = 0.05 and 0.05, respectively) and
multivariate analysis (p = 0.005 and 0.006, respectively).
PMID- 10665763
TI - Prognostic significance of the PC10 index for patients with stage II and III
oesophageal cancer treated with radiotherapy.
AB - The monoclonal antibody PC10 is used for immunohistochemical staining of the
proliferating cell nuclear antigen (PCNA). The percentage of PC10-positive cancer
cells is defined as the PC10 index. We evaluated the relationship between the
PC10 index in pretreatment endoscopic biopsies and the prognoses of 47 patients
with Stage II-III oesophageal squamous cell carcinoma treated with radiotherapy.
The patients with a PC10 index > 40% had significantly poorer prognoses than the
other patients (p = 0.0007). Proportional hazards model analysis indicated that
only the PC10 index was a prognostic factor (p = 0.0009). The patient group of
complete responders showed significantly lower PC10 indices compared to patients
with a partial response or no change (p = 0.049). The PC10 index can be a good
predictive indicator of the prognosis in patients with Stage II-III oesophageal
cancer treated with radiotherapy.
PMID- 10665764
TI - Cost-effectiveness analysis of pegylated-liposomal doxorubicin and liposomal
daunorubicin treatments in patients with Kaposi's sarcoma.
AB - Economic evaluations of new AIDS treatment drugs are important. For physicians
treating patients with Kaposi's sarcoma, these issues are especially meaningful
since cancer treatment costs for this group of patients are high. Kaposi's
sarcoma is the most frequently occurring neoplasm in AIDS patients, affecting
about 15% of this population. In our study, a retrospective economic evaluation
has been made based on data from two randomized phase III clinical studies of
severely immune-compromised HIV-infected individuals and which compares liposomal
doxorubicin with liposomal daunorubicin. We have estimated the cost and cost
effectiveness of the two drugs. The costs per complete or partial response are
USS 18340 for daunorubicin and USS 8871 for doxorubicin. The incremental cost per
additional responder by using liposomal doxorubicin instead of liposomal
daunorubicin is USS 1910. Sensitivity analysis shows that these results hold over
a wide range of assumptions.
PMID- 10665765
TI - Epidemiological characteristics of cutaneous malignant melanoma of the head and
neck--a population-based study.
AB - Since cutaneous malignant melanoma (CMM) and melanoma in situ (MIS) of the head
and neck have only partially been differentiated from CMM of other anatomic
sites, these lesions are classified in detail in this study. Data from 756
patients derived from the population-based register of the Stockholm-Gotland area
were analyzed and the findings showed that the incidence of CMM was 3.4 times
higher in the face compared to the skin outside the head-neck area and that
lentigo maligna melanoma was 74 times and nodular melanoma 2.3 times more common
in the face. Mean age at diagnosis was significantly higher for patients with CMM
of the head and neck irrespective of histogenetic type. Tumor site within the
head and neck related to age at diagnosis. CMM of the head and neck differs from
CMM of other locations. Epidemiological data are in agreement with the hypothesis
that UV radiation (chronic or intermittent) may give rise to melanomas with
various phenotypic traits.
PMID- 10665766
TI - Radioimmunotherapy of DU-145 tumours in nude mice--a pilot study with E4, a novel
monoclonal antibody against prostate cancer.
AB - The anti-tumour effect of the 131I-labelled antiprostate monoclonal antibody
(MAb) E4 was studied in an experimental model with 41 nude mice, subcutaneously
xenografted with a human prostate cancer cell line (DU-145). The mice were
divided into four study groups, i.e. one receiving single and another repeated
injections of the radiolabelled MAb. A third group was injected with non-labelled
MAb, and the fourth served as an untreated control group. The tumour volumes
increased similarly in all groups during the 27-day observation period. The
tumour tissue was morphologically disintegrated in the group that received
repeated radioimmunotherapy (RIT). The tumours from this group contained large
fluid-filled cystic parts and demonstrated pronounced cellular and subcellular
polymorphism in the remaining viable tumour tissue. The untreated control tumours
and single therapy tumours remained solid. The proportion of the total tumour
volume that consisted of viable tumour cells, as determined by morphometric
techniques, was significantly lower in the 131I-E4-treated groups. The use of
131I-labelled E4 MAb has thus demonstrated a promising therapeutic potential.
PMID- 10665767
TI - Short- and long-term effects of irradiation on laryngeal mucosa of the rat.
AB - Although radiotherapy is often used to treat laryngeal carcinoma, there is little
information on the effects of this treatment on laryngeal structures. Rats were
irradiated to the head and neck region and the larynges were studied by light-
and electron-microscopy and immunohistochemistry. Ten days after irradiation, a
change in the ultrastructural appearance of the granules of the subglottic glands
was observed. Substance P-, bombesin- and enkephalin-like immunoreactivity was
increased in local ganglionic cells and glandular nerve fibres. The mast cells
were reduced in number. At examination 4 6 months after irradiation, there were
no obvious differences compared with controls concerning mast-cell numbers and
neuropeptide expression. The ultrastructural changes seen in the subglottic
glands remained to some extent. The results show that structural changes in the
subglottic glands occur concomitantly with an increased expression of certain
neuropeptides in the innervation of these glands, which implies a relationship
between these two parameters. The mast cells respond drastically to irradiation,
but in the long run, regeneration of these cells occurs.
PMID- 10665768
TI - Effects of retroviral-mediated herpes simplex virus thymidine kinase gene
transfer to murine neuroblastoma cell lines in vitro and in vivo.
AB - Selective introduction of genes conferring chemosensitivity on proliferating
tumor cells can be used to treat cancer. We investigated the efficacy of
retrovirus-mediated gene transfer of the herpes simplex virus thymidine kinase
(HSV-TK) gene to murine neuroblastoma cell lines (neuro-2a) in vitro and in vivo.
Retrovirus-mediated HSV-TK gene transfer to the neuro-2a cells resulted in
sensitivity to ganciclovir (GCV) in vitro. In A/J mice, tumors produced from HSV
TK transduced neuro-2a cells regressed after GCV treatment. Intratumoral
injection of recombinant retrovirus expressing HSV-TK gene also inhibited growth
of the tumor established in A/J mice. These results demonstrate that HSV-TK gene
therapy might be a feasible approach for inhibiting the growth of neuroblastoma.
PMID- 10665769
TI - Does bombesin-like peptide mediate radiation-induced anorexia and satiety?
AB - Bombesin (BN) and its mammalian counterpart gastrin-releasing peptide (GRP) act
as neuroregulatory hormones and peripheral and central satiety-inducing agents.
Previously, we demonstrated that irradiation induces an increase in the
expression of BN/GRP in the innervation of the salivary glands in rats. We
therefore carried out a study using radioimmunoassay (RIA) analysis and
immunohistochemistry to examine whether saliva contains BN and whether
irradiation affects the BN release to saliva in rats. Immunoreactivity for BN was
detected not only in the innervation of the parenchyma but also in the duct cells
and in the lumina of the ducts, suggesting entrance of BN into saliva. The RIA
analysis confirmed that rat saliva contains a BN-like peptide. The observation
shows that saliva contains this peptide but that there is no significant increase
following the radiation schedule used. Nevertheless, the occurrence of an
enhanced expression of BN in different peripheral tissues such as the salivary
and laryngeal glands should be taken into consideration when discussing the
clinically important problem of reduced food intake and anorexia in cancer
patients.
PMID- 10665770
TI - A retrospective analysis of Hickman line-associated complications in patients
with solid tumours undergoing infusional chemotherapy.
AB - We present a retrospective analysis of Hickman line use and associated
complications in patients with solid tumours undergoing treatment with infusional
chemotherapy. One hundred and ten lines were inserted in 94 patients (55 females
and 39 males, median age 51), of whom 107 were placed under radiological
screening, the remainder by a surgical approach. Catheters were in situ for a
total of 9670 days (median 101 days, range 1-278). Fifty-five complications
occurred during the lifespan of 39 catheters (35.5%), giving an overall
complication rate of 4.03/1000 catheter days. Early complications included
pneumothorax (4%), arterial puncture (1%) and failure of placement (1%). Late
complications included sepsis (superficial and systemic) (24.5%), venous
thrombosis (9%), line displacement (10%) and catheter blockage (1%). Fifteen
episodes of systemic sepsis occurred in 12 patients, giving an overall sepsis
rate of 1.55/1000 catheter days, while complications requiring catheter removal
occurred in 20 cases (18% of insertions, 2.07/1000 catheter days). We conclude
that the use of Hickman catheters as a means of long-term venous access in
infusional chemotherapy patients is generally safe, but is associated with
significant morbidity.
PMID- 10665771
TI - Patient positioning using artificial intelligence neural networks, trained
magnetic field sensors and magnetic implants.
AB - The purpose of this study was to evaluate the precision of a sensor and to
ascertain the maximum distance between the sensor and the magnet, in a magnetic
positioning system for external beam radiotherapy using a trained artificial
intelligence neural network for position determination. Magnetic positioning for
radiotherapy, previously described by Lennernas and Nilsson, is a functional
technique, but it is time consuming. The sensors are large and the distance
between the sensor and the magnetic implant is limited to short distances. This
paper presents a new technique for positioning, using an artificial intelligence
neural network, which was trained to position the magnetic implant with at least
0.5 mm resolution in X and Y dimensions. The possibility of using the system for
determination in the Z dimension, that is the distance between the magnet and the
sensor, was also investigated. After training, this system positioned the magnet
with a mean error of maximum 0.15 mm in all dimensions and up to 13 mm from the
sensor. Of 400 test positions, 8 determinations had an error larger than 0.5 mm,
maximum 0.55 mm. A position was determined in approximately 0.01 s.
PMID- 10665772
TI - Malignant teratoma of the lung.
PMID- 10665773
TI - Microscopic pulmonary tumoral embolism and subacute cor pulmonale as the first
clinical signs of cancer.
PMID- 10665774
TI - Mucin-negative pseudomesotheliomatous adenocarcinoma of the lung: report of three
cases.
PMID- 10665775
TI - The immunostimulating activities of anti-tumor polysaccharide from K1 capsular
(polysaccharide) antigen isolated from Klebsiella pneumoniae.
AB - We have previously shown that K1 capsular polysaccharide antigen (K1CPS) of
Klebsiella exhibits anti-tumor activities. In the present study, we examined the
effect of K1CPS on cytotoxic effector cells. We found that K1CPS could activate
many cytotoxic effector cells including alloreactive cytotoxic T cells and tumor
infiltrating lymphocytes (TILs). Moreover, K1CPS could increase the anti-tumor
activity of lymphokine-activated killer (LAK) cells, both in vitro and in vivo.
The i.p. injection of K1CPS in low dose could enhance the LAK cytotoxicity and
the effect was further potentiated by coculture of LAK cells with K1CPS and low
concentration of murine rIL-2 in vitro. The phenotypic characterization revealed
that K1CPS might contribute to the increase in CD3+ LAK cell subpopulation by its
in vivo priming effect. In addition, the K1CPS-treated LAK cells were able to
inhibit the growth of WEHI-164 tumor cells in vivo in Winn-type inhibition assay.
Subcutaneous (s.c.) and intraperitoneal (i.p.) adoptive infusion of LAK cells
(splenocytes from K1CPS-treated WEHI-164-bearing mice cultured with K1CPS-plus
rIL-2) into WEHI-164 sarcoma-bearing mice could slightly cause regression in
terms of tumor diameter, and more significantly in sarcoma weight.
PMID- 10665776
TI - Minor role of the C3a receptor in systemic anaphylaxis in the guinea pig.
AB - Previously, Regal et al. [Regal, J.F., Fraser, D.G., Toth, C.A., 1993. Role of
the complement system in antigen-induced bronchoconstriction and changes in blood
pressure in the guinea pig. J. Pharmacol. Exp. Ther. 267, 979-988] demonstrated
that preventing complement system activation resulted in inhibition of
anaphylaxis in the guinea pig, and that the C-terminal 21 amino acids of guinea
pig C3a (C3a-peptide) mimic the symptoms of anaphylactic shock in the guinea pig
[Regal, J.F., 1997. Role of the complement system in pulmonary disorders.
Immunopharmacology 38, 17-25]. To determine if C3a is an essential mediator of
systemic anaphylaxis, the anaphylactic response to ovalbumin (OA) was assessed in
guinea pigs genetically deficient in the C3a receptor (C3aR-) compared to their
control strain of animals which were C3a receptor positive (C3aR+). In addition,
the response to another control strain of animals, Hartley guinea pigs, was
determined. Sensitized guinea pigs were anesthetized, and bronchoconstriction and
changes in blood pressure were monitored in response to intravenous (i.v.)
injection of either C3a-peptide, recombinant human C5a (rHuC5a) or OA. Both
Hartley guinea pigs and C3aR+ animals responded similarly to C3a-peptide and
rHuC5a. C3aR- animals, however, were unresponsive to C3a-peptide and responded
normally to rHuC5a, confirming their functional deficiency of the C3a receptor.
In response to OA, C3aR+ animals and Hartley guinea pigs responded with a severe
bronchoconstriction, an initial transient hypotension, followed by an increase in
blood pressure and a delayed prolonged hypotensive response. In contrast, in C3aR
animals, the increased blood pressure response to OA was significantly
prolonged, the delayed hypotensive response was blunted, and the
bronchoconstriction was delayed compared to the C3aR+ animals. The difference in
the anaphylactic response could not be explained by differing amounts of OA
specific IgG1 antibody or C3a generated during the anaphylactic response. Thus,
these data suggest that C3a plays a minor role in the hypotension of systemic
anaphylaxis and investigation of a role for other products of complement system
activation, either alone or in combination with C3a, is clearly warranted.
PMID- 10665777
TI - Induction of apoptosis of activated murine splenic T cells by cycloprodigiosin
hydrochloride, a novel immunosuppressant.
AB - Two types of immunosuppressants, cycloprodigiosin hydrochloride (cPrG) and L
leucyl-L-leucine methyl ester (LeuLeuOMe), both have the ability to selectively
inhibit the lysosomal function, and a related compound to cPrG, prodigiosin 25-C,
and LeuLeuOMe have been reported to selectively inhibit the T cell function in
vitro. We therefore examined the cell-type specificity of cPrG and LeuLeuOMe
using murine splenocytes. Concanavalin A (Con A)- and lentil lectin-induced
proliferation was suppressed by cPrG more profoundly than lipopolysaccharide
induced proliferation. At the optimal concentration, Con A induced the
proliferation of both CD4+ and CD8+ cells, whereas at a supra-optimal
concentration Con A induced rather selective proliferation of CD8+ cells.
Irrespective of the dose of Con A, CD4+ and CD8+ cells were equally affected by
cPrG. In contrast, LeuLeuOMe induced the selective loss of CD8+ cells. cPrG
enhanced the apoptosis of murine splenocytes and nylon fiber column-purified T
cells cultured in the presence of Con A, as shown by the decrease in cell size
and/or DNA fragmentation. Overall, this study revealed that the cell-type
specificity of cPrG is different from that of LeuLeuOMe, and that the
immunosuppression by cPrG is associated with apoptosis.
PMID- 10665778
TI - Critical role of Kupffer cell CR3 (CD11b/CD18) in the clearance of IgM-opsonized
erythrocytes or soluble beta-glucan.
AB - Liver macrophages (Kupffer cells) play a major role in blood clearance of both C3
opsonized immune complexes and therapeutic beta-glucan polysaccharides. Human
Kupffer cells express three types of C3-receptors: CR1 (C3b-receptor; CD35), CR3
(iC3b- and beta-glucan-receptor), and CR4 (iC3b-receptor; CD11c/CD18). Studies of
isolated macrophages have suggested that CR3 is the major receptor mediating
capture of either C3-opsonized erythrocytes (E) or beta-glucans. In this
investigation, the organ distribution and function of CR3 in the clearance of IgM
opsonized E and soluble CR3-binding polysaccharides were explored in normal vs.
CR3-knockout (CR3-KO) mice. Analysis of intravenously (i.v.) injected 125I-anti
CR3 showed that the major vascular reservoir of CR3 was the liver, followed by
spleen and lungs. By contrast, clearance of 125I-anti-CR1 appeared to be mediated
predominantly by splenic B lymphocytes, as only subsets of splenic macrophages or
Kupffer cells were found to express CR1. Clearance of IgM-opsonized 51Cr-E
occurred rapidly to the livers of normal mice but was nearly absent in CR3-KO
mice. Soluble 125I-beta-glucan exhibited rapid clearance to the liver in normal
mice, whereas clearance in CR3-KO mice was significantly reduced. In conclusion,
Kupffer cell CR3 plays a crucial role in the clearance of both IgM-opsonized E
and beta-glucans.
PMID- 10665779
TI - Selective augmenting effects of nitric oxide on antigen-specific IgE response in
mice.
AB - Here, we report the enhancing effects of nitric oxide (NO) on an IgE antibody
response in mice. Anti-trinitrophenyl (TNP) IgE production induced in vitro in
TNP keyhole limpet hemocyanin (KLH)-primed spleen cells was inhibited by
approximately 70% when an NO synthase (NOS) inhibitor, L-N(G)-monomethyl-L
arginine, was added at 10(-7)-10(-6) M to the lymphocyte culture. On the other
hand, addition of NO-generating agents to the culture resulted in a marked
enhancement of the IgE production. In contrast, anti-TNP IgM and IgG1 responses
were affected only marginally when the IgE production was either suppressed or
augmented by these agents. NO did not directly augment IgE class switching in
normal B cells stimulated with lipopolysaccharide and interleukin (IL)-4. NO
mediated augmentation of the IgE response is considered to be of a physiological
significance because administration of aminoguanidine (AG), an inhibitor of
inducible NOS, to immunized mice resulted in a preferential suppression of anti
TNP IgE production in vivo. This may be explained by the observation that AG
administration increased interferon-gamma expression without changing that of IL
4 in the immunized mice. Taken together, these observations suggest a
pathophysiological role of NO in the development of IgE-mediated allergic
diseases.
PMID- 10665780
TI - Immunological parameters in patients suffering from alcohol-dependence syndrome.
AB - Alcohol abuse is a major cause of abnormal liver development and activity. In
addition to enzymatic malfunction, alcohol and its metabolites induce changes in
the levels of some liver antigens, resulting in immunological disturbance. The
purpose of the present study is to correlate the severity of liver function
impairment with the length of alcohol abuse, in order to be able to use such
tests as indicative of the severity of Alcohol Dependence Syndrome. Thirty-one
alcohol abusers were allocated to three groups on the basis of the levels of
their liver enzymes, and were tested for a variety of immunological parameters
and skin reactions. The data indicate that even though not all immunological
values measured differed significantly from the control values, in those that did
(granulocytes, lymphocytes, CD4/CD8 ratio, C3, IgG, IgM and some skin positive
reactions), the biggest difference was between the healthy volunteers and the
group with the longest abuse period. It is suggested that changes in selected
immunological parameters in alcohol abusers may indicate the severity of their
liver dysfunction.
PMID- 10665781
TI - Selective cyclooxygenase-2 (COX-2) inhibitors reduce anti-Mycobacterium
antibodies in adjuvant arthritic rats.
AB - Adjuvant arthritis, induced by Mycobacterium butyricum, is an experimental
immunopathy that shares many features of human rheumatoid arthritis and, as such,
is one of the most widely used models for studying the anti-inflammatory activity
of compounds. In rats with adjuvant induced arthritis, IgG antibodies to M.
butyricum have been detected and autoantigens that cross react with mycobacteria
may be involved in the pathogenesis of adjuvant arthritis. In this study, the
anti-inflammatory and immunosuppressive activities of two cyclooxygenase-2
selective inhibitors, flosulide and L-745,337, at doses of 0.1, 1 and 5
mg/kg/day, were examined in adjuvant arthritic rats. After 14 days of treatment,
a clear dose-dependent inhibition of plantar edema was seen for both flosulide
(ID50 lower than 0.1 mg/kg) and L-745,337 (ID50 = 0.4 mg/kg). Plasma levels of
IgG anti-M. butyricum antibodies were also decreased by both drugs. In each case
the maximal immunosuppressive effect was observed at doses lower than 5 mg/kg.
The non-selective COX-2 inhibitor, indomethacin (1 mg/kg) decreased paw edema by
65% and the levels of IgG anti-M. butyricum by 45%. Neither cyclooxygenase
selective inhibitors nor indomethacin decreased the delayed hypersensitivity
reaction induced by M. butyricum. Thus, in vivo inhibition of COX-2 inhibited
articular swelling and also the humoral immune response to Mycobacterium.
PMID- 10665782
TI - Differential effects of chronic propranolol treatment on the phenotypic profile
of thymocytes from immature and adult rats.
AB - To elucidate a putative role of beta-adrenoceptors in the modulation of
intrathymic T-cell maturation, the expression of major differentiational antigens
(CD4/CD8 and TCR alphabeta) on the thymocytes from both immature (aged 21 day at
the beginning of the treatment) and adult (aged 75 days at the beginning of
treatment) male rats subjected to a 15-day-long propranolol treatment (0.40
mg/100 g/day, s.c.) was analyzed by two- and one-color flow cytometry,
respectively. Rats of matched age injected with saline served as controls. The
propranolol treatment in immature but not adult rats caused a significant
reduction in both the relative thymus weight and total thymocyte yield. In
addition, a significant increase in the percentage of CD4+ 8+ double-positive
cells, with a proportional decrease in the relative proportion of CD4+ 8- single
positive cells, was found in immature rats. In contrast, a slight but significant
decrease in the percentage of CD4+ 8+ cells with a parallel increase in the
relative proportion of CD4+ 8- cells was found in adult rats. In both groups of
rats, the percentage of TCR alphabeta(total) thymocytes was increased: in
immature rats this was due to an increase in the percentage of TCR alphabeta(low)
thymocytes, while in the adult rats it reflected a rise in the relative
proportion of TCR alphabeta(high) cells. In conclusion, the study revealed that
propranolol treatment in both immature and adult rats alters the relative
proportion of CD4+ 8+ and CD4+ 8- thymocytes, but in opposite fashion, and the
data suggest that this treatment affects distinct fractions within the population
of CD4+ 8+ thymocytes with respect to expression of TCR alphabeta. The results
also indicate that, regardless of rat sexual maturity, the development of
thymocytes towards CD4- 8+ T-cells is relatively insensitive to long-lasting beta
adrenoceptor blockade.
PMID- 10665783
TI - Ascorbic acid modulates in vitro the function of macrophages from mice with
endotoxic shock.
AB - The toxic effects of oxygen radicals produced by immune cells can be controlled
to certain degree by endogenous antioxidants because of their scavenger action.
This control is specially important in a type of immune cell, i.e., the
phagocyte, which produces oxygen-free radicals and uses antioxidants in order to
support its functions. Antioxidants, such as ascorbic acid (AA), are free radical
scavengers and improve the immune response. In the pathogenesis of endotoxic
shock, a disease with high mortality caused by gram-negative bacterial endotoxin,
the reactive oxygen species (ROS) produced by phagocytes have been implicated. In
a previous study, we observed in peritoneal macrophages from BALB/c mice
suffering lethal endotoxic shock caused by intraperitoneal (i.p.) injection of
Escherichia coli lipopolysaccharide (LPS; 100 mg/kg) a high production of
superoxide anion. Therefore, in the present work, we have studied the in vitro
effect of AA, at different concentrations (0.001, 0.01, 0.1, 1 and 2.5 mM), on
the various steps of the phagocytic process, i.e., adherence to substrate,
chemotaxis, ingestion of particles and superoxide anion production of murine
peritoneal macrophages obtained from BALB/c mice with that of endotoxic shock, at
2, 4, 12 and 24 h after LPS injection. The increased adherence, ingestion and
superoxide anion production by macrophages from animals with endotoxic shock were
lower in the presence of AA, reaching similar values to those of the control
animals. The most effective AA concentration in cells from mice with endotoxic
shock was 0.01 mM. These data suggest that AA can regulate the phagocytic process
in endotoxic shock, principally decreasing free radical production and thus it
could reduce endotoxic shock severity.
PMID- 10665784
TI - Carcinoma of the cervix and the use of hyperbaric oxygen with radiotherapy: a
report of a randomised controlled trial.
AB - BACKGROUND AND PURPOSE: A randomised controlled trial of hyperbaric oxygen in the
radiotherapy of Stage IIb and III carcinoma of cervix was performed between 1971
and 1980. Apart from an abstract giving an interim report in 1977, results have
not been published. MATERIAL AND METHODS: In a four arm study, 335 patients were
randomised to treatment in 10 or 28 fractions, in hyperbaric oxygen or in air.
Data is available concerning 327 cases and this has been analysed. RESULTS: There
was no advantage in tumour control shown with the use of hyperbaric oxygen. There
was evidence for an increase in late radiation morbidity when treatment was given
in hyperbaric oxygen rather than in air and when, using 10 fractions, a total
dose of 45 rather than 40 Gy was achieved. For late intestinal morbidity, the
fractionation sensitivity (alpha/beta ratio) was calculated to be 4.3 Gy and the
steepness of the dose response curve (gamma50) to be 2.6. CONCLUSIONS: Hyperbaric
oxygen gave no benefit in the treatment of patients with stage IIb and III
carcinoma of the cervix treated with radiotherapy using two fractionation
regimes. Important data regarding late radiation morbidity has been revealed.
PMID- 10665785
TI - Intratumoral pO2-measurements as predictive assay in the treatment of carcinoma
of the uterine cervix.
AB - BACKGROUND: Several studies have shown that pretreatment oxygenation status of
cervical tumors measured with a polarographic oxygen electrode could be a
predictive factor for radiation response and survival. The purpose of this study
was to evaluate the impact of intratumoral pO2 levels and hypoxic fractions on
local control and disease free survival employing a standardized measuring
procedure under routine conditions. MATERIALS AND METHODS: Between April 1994 and
December 1997 pO2 measurements were performed prior to radiotherapy with an
Eppendorf histograph in 51 evaluable patients with primary cervical carcinoma.
All patients were treated with curative intent by combined external beam therapy
(median total dose 49.6 Gy) and 3-6 applications of high dose rate- (7 Gy/fr. at
point 'A') or pulse dose rate brachytherapy (20-25 h pulses, 1 Gy/pulse at point
'A'). Oxygenation data are given as median pO2 of pooled readings and percentage
of readings below 5 mm Hg (HF 5). RESULTS: Median pO2 values ranged from 0 to 60
mm Hg (median 10). HF5 ranged from 0 to 95% (median 22%). Median follow-up was 26
months (range 9-54 months). Actuarial overall and disease-free survival rates
(OS/DFS) at 3 years were 53%/50%. Comparing patients with median pO2 < or = 10 mm
Hg (n = 26) to patients with higher median pO2 levels (n = 25) calculated DFS was
34 and 69%, respectively (P < 0.02). Corresponding data for local control were 47
and 84% (P = 0.053). Comparing patients with HF5 below and above the median
calculated DFS was 36 and 66%, respectively (P < 0.02). Patients who had median
pO2 < 10 mm Hg and HF5 > 20% had the worst prognosis (3-year DFS: 28%). Besides
oxygenation status, stage and initial hemoglobin concentration were statistically
significant for treatment outcome. CONCLUSIONS: This study confirms earlier data
that the presence of hypoxia is associated with poor local control and survival
in patients with carcinoma of the uterine cervix. Polarographic pO2 measurements
are feasible under routine conditions and can be regarded as a reproducible
predictive assay.
PMID- 10665786
TI - Tumoural perfusion as measured by dynamic computed tomography in head and neck
carcinoma.
AB - PURPOSE: To investigate the intra- and interobserver variability, as well as the
intra- and interpatient variability of CT-determined tumour perfusion in head and
neck tumours, and to evaluate the preliminary value of this parameter as
predictive factor of local failure after treatment by definitive radiotherapy.
MATERIALS AND METHODS: In 41 patients the perfusion of a primary head and neck
squamous cell carcinoma was estimated using dynamic CT. A 40-ml intravenous bolus
of a low-osmolar non-ionic contrast agent was rapidly injected over 5 s (8 ml/s),
while a dynamic acquisition of image data was obtained during the first pass at
the level of the largest axial tumour surface. A time-density curve was
constructed for the primary tumour and the carotid artery. The perfusion in the
selected tumour region of interest was calculated by dividing the slope of the
tumour-time density curve by the maximal value in arterial density. Tumour volume
was calculated on the CT-images and correlated with perfusion rate. RESULTS: The
mean perfusion rate was 86.4 ml/min per 100 g (median, 80.6; SD, 43.05; range,
31.7-239.8 ml/min per 100 g). No systematic difference was found between the
measurements performed by two independent observers. The intratumoural COV was
0.22, the intertumoural COV 0.37. No correlation was found with tumour volume.
Ten out of 20 patients with a perfusion rate < 80 ml/min per 100 g were not
locally controlled, while nine out of 21 patients with a value > 80 ml/min per
100 g did show a local failure (P = 0.19). CONCLUSIONS: CT-determined perfusion
measurements of head and neck tumours are feasible. No correlation with tumour
volume and a sufficiently large COV were found to consider this parameter as a
possible prognostic factor for outcome after radiotherapy. More patients need to
be investigated to test the hypothesis that tumours with a low CT determined
perfusion rate have a higher risk of local failure.
PMID- 10665787
TI - Oxygenation of head and neck cancer: changes during radiotherapy and impact on
treatment outcome.
AB - BACKGROUND AND PURPOSE: To evaluate the long term clinical significance of tumor
oxygenation in a population of head and neck cancer patients receiving
radiotherapy and to assess changes in tumor oxygenation during the course of
treatment. METHODS AND MATERIALS: Patients with head and neck cancer receiving
primary RT underwent pretreatment polarographic tumor oxygen measurement of the
primary site or a metastatic neck lymph node. Treatment consisted of once daily
(2 Gy/fraction to a total dose of 66-70 Gy) or twice daily irradiation (1.25
Gy/fraction to 70-75 Gy) to the primary site. Twenty-seven patients underwent a
second series of measurements early in the course of irradiation. RESULTS: Sixty
three patients underwent pretreatment tumor oxygen assessment (primary site, n =
24; nodes, n = 39). The median pO2 for primary lesions was 4.8 mmHg, and it was
4.3 mmHg for cervical nodes. There was a weak association between anemia and more
poorly oxygened tumors, but many non-anemic patients still had poorly oxygenated
tumors. Repeat assessments of tumor oxygenation after 10-15 Gy were unchanged
compared to pretreatment baselines. Poorly oxygenated nodes pretreatment were
more likely to contain viable residual disease at post-radiation neck dissection.
Median follow-up time for surviving patients was 20 months (range 3-50 months).
Hypoxia (tumor median pO2 <10 mmHg) adversely affected 2 year local-regional
control (30 vs. 73%, P = 0.01), disease-free survival (26 vs. 73%, P = 0.005),
and survival (35 vs. 83%, P = 0.02). CONCLUSION: Tumor oxygenation affects the
prognosis of head and neck cancer independently of other known prognostic
variables. This parameter may be a useful tool for the selection of patients for
investigational treatment strategies.
PMID- 10665788
TI - Prognostic impact of total tumor volume and hemoglobin concentration on the
outcome of patients with advanced head and neck cancer after concomitant boost
radiochemotherapy.
AB - PURPOSE: To identify prognostic clinical and treatment related factors for local
control, distant metastasis-free survival, and survival by means of a
multivariate analysis in patients with advanced squamous cell carcinoma of the
head and neck after concomitant boost radiochemotherapy. PATIENTS AND METHODS:
From 1992 to 1995, 68 patients with squamous cell cancer of the head and neck
(93% stage IV disease) were treated with a simultaneous radiochemotherapy with
Carboplatin using a concomitant boost technique. The total tumor volume (TTV) was
quantitatively determined based on computed tomography scans in 56 patients. A
Cox proportional hazards regression analysis was performed for each of the above
endpoints and statistical significance of the Cox models was verified using the
likelihood ratio test and Bonferroni correction for multiple testing. RESULTS:
The survival and locoregional control rates at three years were 35 and 32%. The
multivariate analysis revealed a significant association between the TTV and
survival (P = 0.0008) and between the pretreatment serum hemoglobin concentration
and locoregional control (P = 0.01) and survival (P = 0.05). The locoregional
control was significantly associated with the N-stage (P = 0.007) and there was a
good correlation between the N-stage and TTV in this study population.
CONCLUSION: Our data corroborate the prognostic relevance of the tumor volume and
hemoglobin concentration. In studies comparing the survival of patients with
advanced cancer of the head and neck, the use of the TTV as a covariable may
improve the statistical power.
PMID- 10665789
TI - Polarographic measurements of oxygen tension in human glioma and surrounding
peritumoural brain tissue.
AB - This study quantifies the spatial distribution of pO2 in glioma and in the
surrounding brain tissue. Both glioma and peritumoural brain contain regions at
oxygen tensions less than 2.5 mmHg. Modalities targeting hypoxia to improve the
efficacy of therapy may have an important role in the management of this disease.
PMID- 10665790
TI - Results of ruthenium irradiation of uveal melanomas: the Dutch experience.
AB - BACKGROUND AND PURPOSE: To update our results of the treatment of uveal melanomas
using ruthenium applicators in 49 patients treated with graded doses and
subsequently in 52 patients with maximal scleral doses of 800 Gy and an effective
top dose of at least 160 Gy. MATERIAL AND METHODS: One hundred and one patients
were treated with brachytherapy only, in 25 patients it was combined with
transpupillary thermotherapy (TTT). RESULTS: A complete remission was found in
62.6% of the patients and in 31.3% a stable disease with an average follow-up of
74.6 months. Above a top dose of 120 Gy only in one of 95 patients continuous
tumour growth after treatment was observed. Useful vision could be preserved in
51.5% of the patients. The initial tumour prominence and top dose strongly
correlated with treatment outcome. CONCLUSIONS: Ruthenium application for uveal
melanomas with the doses we have used is successful, with a substantial number of
patients having their eyes preserved, their tumour controlled and their vision
retained. Further improvements can be obtained with ruthenium irradiation with
lower maximal scleral doses combined with TTT.
PMID- 10665791
TI - Radiotherapy of unilateral choroidal metastasis: unilateral irradiation or
bilateral irradiation for sterilization of suspected contralateral disease?
AB - Radiotherapy is the highly effective standard in the treatment of choroidal
metastasis. Visual acuity can be stabilized or increased in about 70-80% of eyes
treated, thus prevailing the quality of life in these worse prognostic patients.
In about 30-40% bilateral macroscopic disease is found at diagnosis. The best
treatment for unilateral metastasis remains controversial: unilateral or
bilateral irradiation for sterilization of suspected contralateral metastasis or
unilateral irradiation without irradiation of the contralateral choroidea. In the
analysis of a prospective study (ARO 95-08) 35 out of 50 patients with choroidal
metastasis had unilateral disease and received unilateral irradiation with a
lateral field using 6 MeV-photons (40 Gy in 20 fractions) without sparing the
contralateral choroidea. Therefore the posterior contralateral choroidea received
50-70% of the total dose (20-28 Gy) for suspected micrometastasis. None of these
patients developed contralateral choroidal metastasis during the median follow up
time of 11.5 months. A unilateral field with 40 Gy for unilateral choroidal
metastasis without sparing the contralateral choroidea seems to be effective in
destroying contralateral micrometastasis with a lower risk of late side effects
compared with bilateral fields.
PMID- 10665792
TI - Radiation late effects in children treated for orbital rhabdomyosarcoma.
AB - BACKGROUND AND PURPOSE: The experience resulting from large cooperative studies
shows that correct radiation therapy at doses adequate to the tumor bulk are
crucial for local control of rhabdomyosarcoma. The aim of the present study was
to document the correlation between modalities and doses of radiotherapy and
radiation side effects. PATIENTS AND METHODS: Between 1980 and 1997, 19 patients
affected by primary orbital rhabdomyosarcoma have been followed at the University
Federico II of Naples. All but three patients, who received 45, 54 and 55 Gy
respectively, have been treated by immediate radiation at the dose of 60 Gy,
delivered in 2 Gy fractions, five times per week, by cobalt 60 megavoltage
equipment. Combined chemotherapy using vincristine and vincristine plus
dactinomycin on alternate weeks was also administered as part of induction
therapy. RESULTS: An overall survival rate of 94.7% was registered. In our
patients the majority of radiation late effects were paid by orbit and ocular
adnexa. Side effects to lens and ocular structures were fewer and of low grade.
CONCLUSIONS: Radiation therapy is still essential for local control of orbital
rhabdomyosarcoma, however radiation side effects have to be carefully considered
together with the therapeutic goal to be obtained.
PMID- 10665793
TI - Evaluation of frequency and type of errors detected by a computerized record and
verify system during radiation treatment.
AB - BACKGROUND: Computerized record and verify systems (RVS) have been introduced to
improve the precision of radiation treatment delivery. These systems prevent the
delivery of ionizing radiations when the settings of the treatment machine do not
match the intended parameters within some maximal authorized deviation. PURPOSE:
To assess the potential alteration of the frequency of errors associated with the
use of RVS during radiation treatment delivery. MATERIALS AND METHODS: The
software of the RVS was altered in order to record the settings actually used for
radiation treatment delivery whereas the verification function was suppressed. At
the end of the study period, the settings used during daily administration of
radiation treatment were compared to the parameters recorded in the RVS using the
computer. They were also compared with the planned ones written in the patient
treatment chart. RESULTS: Out of the 147,476 parameters examined during the study
period, 678 (0.46%) were set erroneously. At least one error occurred in 628
(3.22%) of the 19,512 treated fields. An erroneous parameter was introduced in
the RVS memory in 22 (1.17%) of the 1885 fields. CONCLUSIONS: RVS has the
potential to improve precision of radiation treatment delivery by detecting a
significant number of setting errors. However, excessive confidence in RVS could
lead to repeated errors as there is a potential for the entry of erroneous
parameters into the RVS memory.
PMID- 10665794
TI - Diamond detector measurements near simulated air channels for narrow photon
beams.
AB - BACKGROUND AND PURPOSE: To evaluate the combined effect of increased photon
transmission, reduced photon scatter, increased secondary electron range and loss
of electronic equilibrium for narrow 6-MV beams in and around a simulated air
channel. MATERIALS AND METHODS: A measuring method was developed in-house for
relative dose measurements near simulated air-like/soft-tissue interfaces in an
automated water phantom. A Styrofoam cylinder (density 0.03 g/cm3) of 2-cm
diameter was submersed in the water phantom and irradiated with small rectangular
radiation fields. The field length was fixed at 10 cm and the field widths ranged
from 1 to 4 cm. The axis of the foam cylinder and the long side of the field were
parallel. A water layer of 2 cm was realised upstream of the cylinder. Relative
depth dose and profiles behind the foam cavity were assessed using a diamond
detector with a sensitive crystal thickness of 0.21 mm located at 1 mm from the
top of the encapsulation. RESULTS: The dose at central axis 1.1 mm behind the
cavity was found to be 92 and 74% for a field size of 10 x 2 and 10 x 1 cm2,
respectively. The highly convex dose profile of the 10 x 1-cm2 field,
characterising the homogeneous case, is flattened. CONCLUSIONS: The diamond
detector is an excellent choice as a detector in small photon fields with high
dose gradients as they occur near air channels, provided the orientation of the
detector is appropriate. Doses near air channels are subject to significant local
variations as a function of small changes of field width, and local underdosing
may occur in particular cases.
PMID- 10665795
TI - The use of high density metal foils to increase surface dose in low-energy
clinical electron beams.
AB - BACKGROUND AND PURPOSE: This paper describes a practical method of elevating the
surface dose of clinical electron beams in the energy range 3-12 MeV using thin
high density metal foils (tin and lead) as an alternative to tissue equivalent
bolus. Because, relative to water, these materials exhibit a high scattering
power to stopping power ratio, the desired dose elevation may be achieved with
less energy loss than conventional bolus and consequently a gain in therapeutic
interval. METHODS: The foil thickness required to raise the surface dose to 90%
off peak, for a given electron energy, was calculated using published scattering
and stopping power data. An empirical expression is derived to facilitate
calculation of foil thickness (tin or lead) to produce a given surface dose.
RESULTS AND CONCLUSIONS: Measurements were made to confirm the predictions of the
derived expression and were found to be in good agreement.
PMID- 10665796
TI - Is tourniquet use ineffective in the pre-hospital management of South American
rattlesnake bite?
PMID- 10665797
TI - Cloning and functional expression of a synthetic gene encoding huwentoxin-I, a
neurotoxin from the Chinese bird spider (Selenocosmia huwena).
AB - Cloning and functional expression of a synthetic gene encoding huwentoxin-I, a
neurotoxin from the Chinese bird spider Selenocosmia huwena. A gene encoding
huwentoxin-I, a peptide neurotoxin consisted of 33 amino acid residues from the
venom of the Chinese bird spider Selenocosmia huwena, was designed, synthesized
and expressed in Escherichia coli as a hybrid protein fused with glutathione S
transferase at the N-terminal. The fusion protein was purified by GSH-Sepharose
4B affinity column chromatography and cleaved by thrombin to release the toxin
peptide. The amino acid sequence of the recombinant toxin was consistent with the
designed one by sequence determination and MALDI-TOF mass analysis, suggesting
that the recombinant huwentoxin-I produced the same expression product as the
native one. After reduction and renaturation, the biological activity of the
recombinant toxin was identical with that of the native huwentoxin-I by
electrophysiological method.
PMID- 10665798
TI - Some biochemical properties of Russell's viper (Daboia russelli) venom from
Eastern India: correlation with clinico-pathological manifestation in Russell's
viper bite.
AB - In the present study, some biochemical properties and pathological effects of
Daboia russelli venom from Burdwan district of West Bengal, eastern India are
presented. The clinical features of Russell's viper envenomation observed in
patients admitted to Burdwan Medical College & Hospital are also reported. In
vitro, whole venom exerts strong trypsin inhibitory, phospholipase A2 and
procoagulant activities in addition to moderate adenosine monophosphatase and
adenosine triphosphatase activities. Lethality (LD50) of this venom sample is 0.7
mg kg (i.v.) of mice. Significant local tissue damaging effects including edema,
hemorrhage and necrosis are observed in experimental animal models. An increase
in the level of serum enzymes, such as aspartate transaminase, alkaline
phosphatase, creatine phosphokinase, lactate dehydrogenase after D. russelli
venom injection in albino rats is indicative of cell or tissue damage. High
incidence of intravascular hemolysis in addition to hemostasis, haemoptysis and
haematuria are observed as the most prominent features of RVV envenomation from
this part of India. The present study reinforces the hypothesis that variation in
the venom composition of RVV from eastern India with respect to venom samples of
Russell's vipers from other parts of India is responsible for the differences in
the clinical manifestation in patients from eastern India.
PMID- 10665799
TI - Beta-agkistrodotoxin inhibits fast and Ca2+-activated K+ currents recorded from
mouse motor nerve terminals.
AB - Beta-agkistrodotoxin (beta-AgTx), a polypeptide purified from the venom of
Agkistrodon blomhoffii brevicaudus, is a presynaptic blocker acting on
neurotransmitter release. In this work, perineural recording technique was
employed to study the effects of beta-AgTx on sodium, potassium and calcium
currents of mouse motor nerve terminals. The results showed that beta-AgTx
selectively inhibited Ca2+-dependent (I(K,Ca)) and fast (I(K,f) K+ currents, but
did not affect slow K+ current (I(K,s)), sodium and calcium currents. However
there are other components in A. blomhoffii brevicaudus venom which inhibit
perineural sodium current. The present data have provided additional evidence
that the site of action of beta-AgTx is different from that of beta-bungarotoxin.
PMID- 10665800
TI - m1-toxin isotoxins from the green mamba (Dendroaspis angusticeps) that
selectively block m1 muscarinic receptors.
AB - The venom of the green mamba, Dendroaspis angusticeps, was found to have at least
six trace m1-specific toxins that block the binding of 3H-N-methylscopolamine to
cloned m1 muscarinic receptors. Four were isolated by gel filtration, cation
exchange HPLC and reversed-phase HPLC and named m1-toxins1-4. Recovery was 180,
90, 20 and 10 microg/g dry venom, respectively. m1-Toxin1 (the original m1-toxin)
was found to have the sequence, L T C V K S N S I W F P T S E D C P D G Q N LC F
K R W Q Y I S P R M Y D F T R G C A A T C P K A E Y R D V I N C C G T D K C N K,
calculated mass = 7473 Da and calculated pI = 8.2. This sequence had been
predicted previously from a cDNA cloned from the venom glands of this snake. The
binding of m1-toxin1 was irreversible, so its Kd could not be determined. m1
Toxin2 differed only in proline-19, mass = 7455 and pI = 8.5. Partial sequence
data for m1-toxin3 showed aspartate-7 and m1-toxin4 showed isoleucine-12,
asparagine-16 and alanine-19. m1-Toxins1-4 have seven conserved amino acids not
found in homologous mamba toxins that bind to other muscarinic receptors (MT1,
MT2, m4-toxin = MT3, MT4, MT5, MTalpha and MTbeta). Some of these residues may be
essential for m1-specificity. Since m1-toxin1 binds irreversibly in artificial
cerebrospinal fluid at 37 degrees C, it is a particularly attractive antagonist
for studies in vivo.
PMID- 10665801
TI - Effect of crotapotin and heparin on the rat paw oedema induced by different
secretory phospholipases A2.
AB - The effects of crotapotin (a non-toxic and non-enzymatic acid polypeptide
naturally complexed with phospholipase A2) and heparin on rat paw edema induced
by different secretory phospholipases A2 (sPLA2) have been investigated. The
ability of crotapotin to affect the enzymatic activity of the sPLA2(s) have also
been evaluated. Secretory PLA2(s) obtained from both snake (Naja naja, Naja
mocambique mocambique, Crotalus adamanteus and Crotalus durissus terrificus) and
bee (Apis mellifera) venoms as well as that from bovine pancreas were used in
this study. Rat paw oedema was induced by a single subplantar injection of the
sPLA2s (5-30 microg/paw) in absence and presence of either crotapotin (10-100
microg/paw) or heparin (50 U/paw). Paw volume was measured using a
hydroplethysmometer. Phospholipase A2 from Naja naja, Naja mocambique mocambique,
Apis mellifera venoms and the basic component of Crotalus durissus terrificus
venom all induced dose-dependent rat paw oedema whereas those from Crotalus
adamanteus venom and bovine pancreas were ineffective. Paw oedema induced by
PLA2(s) from both Naja naja and Apis mellifera venoms was significantly (P <
0.05) inhibited by crotapotin (0.1-100 microg/site) whereas the Naja mocambique
mocambique venom PLA2-induced oedema was significantly potentiated (P < 0.05) by
this polypeptide (40 microg/site). On the other hand, heparin (50 U/paw) had no
effect on the paw oedema induced by PLA2 from Naja naja and Apis mellifera venoms
but significantly inhibited the Naja mocambique mocambique venom PLA2-induced
oedema. The measurement of the in vitro phospholipasic activity revealed that
crotapotin inhibited by 60-70% the enzymatic activities of PLA2(s) from Crotalus
adamanteus, Naja mocambique mocambique, Apis mellifera venoms and bovine
pancreas. Our results suggest that despite the great homology between the various
types of sPLA2 they interact with crotapotin on cell surfaces in different ways
leading to either inhibition or potentiation of the paw oedema by a mechanism
unrelated to their enzymatic activities. Since heparin reduced paw oedema induced
by PLA2 from Naja mocambique mocambique venom it is likely that this sPLA2 is
similar to the novel heparin-sensitive PLA2 found in mast cells.
PMID- 10665802
TI - Bothrops lanceolatus (Fer de lance) venom induces oedema formation and increases
vascular permeability in the mouse hind paw.
AB - The ability of snake venoms to increase vascular permeability and to induce
oedema through the release of pharmacologically active substances is well known.
We have studied the oedema and vascular permeability induced by Bothrops
lanceolatus venom in male Swiss white mice. Paw oedema was induced by the
subplantar injection of B. lanceolatus venom (125-1000 ng/paw) and was quantified
as the increase in paw weight. Changes in vascular permeability were assessed by
measuring the amount of Evans blue dye extravasation. The oedema and the increase
in vascular permeability were maximal within 2 h and had resolved after 24 h. The
administration of the vasodilator iloprost (20 ng/paw) immediately after B.
lanceolatus venom potentiated the oedema and the increase in vascular
permeability by approximately four-fold. Pretreating the mice with indomethacin,
dexamethasone, NDGA or BW A4C inhibited the venom-induced oedema and the increase
in vascular permeability. In contrast, histamine, serotonin and PAF-acether
antagonists (mepyramine, cyproheptadine and WEB 2086, respectively) were
ineffective. Histological examination showed that B. lanceolatus venom (250 ng
and 500 ng/paw) caused thickening of the inner dermal layers which was
accompanied by extensive intercellular spaces indicative of oedema. In addition,
there was a marked infiltration of inflammatory cells, particularly neutrophils,
into the underlying muscle layer. The latter, however, remained morphologically
unaffected during the 3 h of observation. Venom doses larger than 500 ng/paw
produced intense haemorrhage. These results indicate that B. lanceolatus venom
induces oedema and increases vascular permeability in the mouse hind paw. The
principal mediators of this inflammatory response are cyclooxygenase and
lipoxygenase products.
PMID- 10665803
TI - Venom alkaloids of fire ants in relation to worker size and age.
AB - Piperidine alkaloids compose most of the venom of the red imported fire ant,
Solenopsis invicta, and we examined how six of these alkaloids varied across
worker size and age. In a colony sampled intensively, the relative abundance of
each alkaloid was highly correlated with worker size with one exception, and
ratios of saturated to unsaturated alkaloids were positively correlated with
worker size. Similarly, both the abundance and ratios of alkaloids differed
significantly between the small and large workers sampled from colonies across
Texas, USA. Young and old workers produced less venom than ants of intermediate
age (3-7 weeks), and ratios of saturated to unsaturated alkaloids increased
significantly with worker age. The differences in venom composition correspond to
the size- and age-based functional roles of workers.
PMID- 10665804
TI - Comparative study on the ability of IgG and Fab sheep antivenoms to neutralize
local hemorrhage, edema and myonecrosis induced by Bothrops asper (terciopelo)
snake venom.
AB - The ability of sheep antivenoms, consisting of whole IgG molecules or Fab
fragments, to neutralize local hemorrhage, edema and myonecrosis induced by
Bothrops asper venom was comparatively studied in mice. The two antivenoms were
produced from the same batch of hyperimmune plasma and were adjusted to the same
neutralizing potency against these effects in assays where venom and antivenoms
were incubated prior to injection. Thus, if differences are observed in
experiments involving independent injection of venom and antivenoms, they would
depend on the pharmacokinetic profiles of the products. Despite the observation
that both antivenoms neutralized the three effects if preincubated with venom,
neutralization was only partial when antivenoms were administered i.v. at various
time intervals after envenomation. No significant differences were observed
between IgG and Fab antivenoms concerning neutralization of hemorrhagic and edema
forming activities, whereas IgG antivenom was slightly more effective in
neutralizing myotoxic activity in experiments involving independent injection of
venom and antivenom. These results do not support the hypothesis that Fab
fragments are more effective than whole IgG molecules in the neutralization of
locally-acting toxins from B. asper venom.
PMID- 10665805
TI - Sensitivity of embryonic rat dorsal root ganglia neurons to Clostridium botulinum
neurotoxins.
AB - Clostridium botulinum neurotoxins (BoNT) are zinc dependent endopeptidases which,
once internalised into the neuronal cytosol, block neurotransmission by
proteolysis of membrane-associated proteins putatively involved in synaptic
vesicle docking and fusion with the plasma membrane. Although many studies have
used a variety of cellular systems to study the neurotoxins, most require
relatively large amounts of toxin or permeabilisation to internalise the
neurotoxin. We present here a primary culture of embryonic rat dorsal root
ganglia (DRG) neurons that exhibits calcium-dependent substance P secretion when
depolarised with elevated extracellular potassium and is naturally BoNT
sensitive. The DRG neurons showed a different IC50 for each of the toxins tested
with a 1000 fold difference between the most and least potent neurotoxins (0.05,
0.3, 30 and approximately 60 nM for A, C, F and B, respectively). BoNT/A cleavage
of SNAP-25 was seen as early as 2 h, but substance P secretion was not
significantly inhibited until 4 h intoxication and the effects of BoNT/A were
observed for as long as 15 days. This primary neuronal culture system represents
a new and sensitive cellular model for the in vitro study of the botulinum
neurotoxins.
PMID- 10665806
TI - Amino acid sequence studies on cytolytic toxins from sea anemone Heteractis
magnifica, Entacmaea quadricolor and Stichodactyla mertensii (Anthozoa).
AB - The complete amino acid sequence of a cytolytic toxin, HmT, isolated from sea
anemone Heteractis magnifica was determined. It is composed of 177 amino acid
residues and lacks half-cystines. Partial N-terminal sequences of three other
cytolysins from Entacmaea quadricolor (EnT) and Stichodactyla mertensii (SmT-1
and SmT-2) were also determined. Comparing these sequences with those of other
sea anemone cytolysins, a high degree of homology was observed.
PMID- 10665807
TI - Structural and ultrastructural description of the venom gland of Loxosceles
intermedia (brown spider).
AB - The brown spider, genus Loxosceles, is becoming of great medical importance, with
envenomation (Loxoscelism) occurring throughout the world. The biological
activities of the brown spider venom usually include dermonecrotic lesions at the
bite site accompanied by hemolytic and haemorrhagic effects and also by renal
failure. The objective of the present study was to describe the histology of the
venom gland of L. intermedia using glands from adult spiders which were
investigated by light microscopy, using immunohistochemical and staining methods,
by transmission electron microscopy, and by scanning electron microscopy. The
organization of the venom gland of Loxosceles intermedia follows the general
architecture of spiders' venom glands. Using light microscopy and transmission
electron microscopy we observed that the venom glands of L. intermedia present
two layers of striated muscle fibers, an external layer and an internal layer in
touch with an extracellular matrix which is a basement membrane structure and a
fibrillar collagen matrix separating the muscular region from epithelial cells of
the venom gland. Muscle cells are multinucleated, with nuclei peripherally placed
and their cytoplasm rich in sarcoplasmic reticulum, myofibrills and continuous Z
lines. By using scanning electron microscopy we can detect muscular cells from
external layer as branching cells. Epithelial cells have their cytosol extremely
rich in rough endoplasmic reticulum, mitochondria collection, Golgi apparatus,
interdigitating membranes and secretory vesicles that ultimately accumulate the
venom, a complex protein mixture.
PMID- 10665808
TI - An investigation of the degradation of the plant toxin, ricin, by sodium
hypochlorite.
AB - The toxin, ricin (0.4 microg/microl), was exposed to a range of sodium
hypochlorite concentrations. SDS PAGE showed that hypochlorite caused the ricin
to smear and decrease in mobility and, ultimately, caused a loss of silver
staining. Cytotoxicity assays using dye uptake by Hep2 cells showed that
treatment with 3 mM hypochlorite inactivated the ricin. Western blotting and
ELISAs showed that binding by polyclonal antibodies raised against native ricin,
or partially degraded ricin, diminished as hypochlorite degradation of the ricin
increased.
PMID- 10665809
TI - The influence of hunger and breeding temperature on the venom production of the
spider Cupiennius salei (Araneae, Ctenidae).
AB - The venom production of the free hunting neotropic spider Cupiennius salei was
tested under different breeding conditions. Three groups kept at different
temperatures (17, 21 and 25 degrees C) showed that venom production remained
stable within this temperature range, only at a temperature of 15 degrees C the
spiders stopped feeding and venom synthesis. Hunger periods do not have a direct
effect on the released venom quantity. Two groups of spiders--the first group
after a four and the second after an eight weeks hunger period--were compared and
no difference in venom production was found. Such long fasting periods are a
natural situation for spiders. In this case Cupiennius salei reduces its body
weight but not venom supply. This means that body weight is a parameter only of
short-term fitness which changes with the actual living conditions (temperature,
feeding intervals) of each individual. Long-term fitness is best described by the
prosoma length, which was formed during the juvenile growth of each spider and is
rather invariable in adulthood. It was shown that the quantity of released venom
is better correlated with the length of the prosoma than with the weight of the
animal. This means that venom production is mostly an indicator of long-term
fitness.
PMID- 10665810
TI - Notes on the traditional use of plants to treat snake bite in northern Papua New
Guinea.
AB - Information on snake bite treatment using plants was collected in three areas of
northern Papua New Guinea. Liquid from six plants is either placed topically on
the bite site or plant parts (bark) are chewed and the sap is swallowed. However,
beside tannins in the bark no secondary metabolites, e.g. alkaloids, steroids,
saponins or flavonoids have been detected by thin-layer chromatography in
alcoholic extracts of the plants involved rendering this type of snake bite
treatment questionable.
PMID- 10665811
TI - The adsorption of microcystin-LR by natural clay particles.
AB - The microcystin cyanobacterial hepatotoxins represent an increasingly severe
global health hazard. Since microcystins are found world wide in drinking water
reservoirs concern about the impact on human health has prompted investigations
into remedial water treatment methods. This preliminary study investigates the
scavenging from water of microcystin-LR by fine-grained particles known to have a
high concentration of the clay minerals kaolinite and montmorillonite. The
results show that more than 81% of microcystin-LR can be removed from water by
clay material. Thus, microcystin-LR is indeed scavenged from water bodies by fine
grained particles and that this property may offer an effective method of
stripping these toxins from drinking water supplies.
PMID- 10665812
TI - Hepatotoxicity of Eupatorium adenophorum to rats.
AB - Freeze dried Eupatorium adenophorum leaf powder mixed in rat feed at a level of
25% elicited hepatotoxicity. The affected animals were jaundiced and had marked
increase in plasma bilirubin levels and activities of alkaline phosphatase,
glutamate oxaloacetate transaminase and glutamate pyruvate transaminase. The
liver of intoxicated animals had focal areas of necrosis and bile duct
proliferation. Elevation in plasma bilirubin concomitant with alterations in
enzyme profile and histopathological lesions are consistent with liver injury and
cholestasis. This is the first report of the toxicity of E. adenophorum to rats.
PMID- 10665813
TI - Bibliography of toxinology.
PMID- 10665814
TI - Determinants of voltage-dependent inactivation affect Mibefradil block of calcium
channels.
AB - The voltage gated calcium channel family is a major target for a range of
therapeutic drugs. Mibefradil (Ro 40-5967) belongs to a new chemical class of
these molecules which differs from other Ca2+ antagonists by its ability to
potently block T-type Ca2+ channels. However, this molecule has also been shown
to inhibit other Ca2+ channel subtypes. To further analyze the mechanism
governing the Ca2+ channel-Mibefradil interaction, we examined the effect of
Mibefradil on various recombinant Ca2+ channels expressed in mammalian cells from
their cloned cDNAs, using Ca2+ as the permeant ion at physiological
concentration. Expression of alpha1A, alpha1C, and alpha1E in tsA 201 cells
resulted in Ca2+ currents with functional characteristics closely related to
those of their native counterparts. Mibefradil blocked alpha1A and alpha1E with a
Kd comparable to that reported for T-type channels, but had a lower affinity
(approximately 30-fold) for alpha1C. For each channel, inhibition by Mibefradil
was consistent with high-affinity binding to the inactivated state. Modulation of
the voltage-dependent inactivation properties by the nature of the coexpressed
beta subunit or the alpha1 splice variant altered block at the Mibefradil
receptor site. Therefore, we conclude that the tissue and sub-cellular
localization of calcium channel subunits as well as their specific associations
are essential parameters to understand the in vivo effects of Mibefradil.
PMID- 10665815
TI - A point mutation in the maxi-K clone dSlo forms a high affinity site for
charybdotoxin.
AB - This work investigated the interaction of CTX with two cloned analogues of the
maxi-K channel, dSlo and hSlo. dSlo has been reported to be CTX insensitive.
Single channel analysis revealed that dSlo was weakly blocked by the toxin, with
a very high K(D) of 5.8 microM. The hSlo channels bound wild-type, recombinant
CTX with high affinity and in a bimolecular fashion, and displayed a half
blocking concentration (K(D)) of 36 nM. A glutamate residue was substituted for
the wild-type threonine at position 290 in dSlo. The mutant channel was expressed
in COS-7 cells and reconstituted into lipid bilayers for single channel analysis.
The mutant channel bound wild-type, recombinant CTX with high affinity and in a
bimolecular fashion, and displayed a half-blocking concentration (K(D)) of 23 nM.
Changing just one residue from threonine to glutamate at position 290 in dSlo
changed the affinity of the channel's CTX-receptor over 100-fold. Kinetic
analysis revealed that this large increase in affinity was due to decreasing the
dissociation rate of the toxin. These results suggest that a CTX receptor does
exist in the dSlo channel mouth and that the threonine at position 290
destabilizes the toxin on the binding site.
PMID- 10665816
TI - The contributions of GluR2 to allosteric modulation of AMPA receptors.
AB - Native AMPA receptor complexes in the CNS are composed of hetero-oligomers of the
GluR1-4 subunits, and generally contain the GluR2 subunit. To determine the
contributions of GluR2 to pharmacological properties of receptor complexes, the
effect of hetero-oligomerization with GluR2 on allosteric modulation of
recombinant AMPA receptors was studied. The study of homo-oligomeric GluR2 was
facilitated with a site-directed mutant of the pore, GluR2(R607Q), which allowed
robust currents from this normally low-conducting subunit. The efficacy of the
allosteric modulators was tested on homo-oligomeric GluR1-4, and then compared
with hetero-oligomeric GluR1/GluR2, GluR3/GluR2 and GluR4/GluR2. Two selective
allosteric modulators were tested, a positive modulator, cyclothiazide, and a
negative modulator, LY300164. The results show that the pharmacological
properties of homo-oligomeric GluR2 are not significantly different from those of
GluR1, GluR3 or GluR4. The apparent affinity of cyclothiazide is not
significantly changed upon hetero-oligomerization. However, the extent of
potentiation of kainate responses by cyclothiazide is significantly decreased
upon hetero-oligomerization. Hetero-oligomerization increases the apparent
affinity of LY300164, a (-) isomer of the 2,3-benzodiazepine LY293606. These data
indicate that although GluR2 has a dominant effect on the permeation properties,
this subunit does not have a similarly dominant effect on pharmacological
properties of native receptors. However, the state of hetero-oligomerization can
alter the pharmacological properties of AMPA receptors.
PMID- 10665817
TI - Cocaine-induced kindling is associated with elevated NMDA receptor binding in
discrete mouse brain regions.
AB - The present study was undertaken to investigate the involvement of N-methyl-D
aspartate (NMDA) type of glutamate receptors in the induction and maintenance of
kindling generated by daily cocaine (35 mg/kg) injections to Swiss Webster mice.
In addition, the regulation of NMDA receptor binding following the development of
sensitization to horizontal locomotor activity produced by daily injections of a
low dose of cocaine (15 mg/kg for 5 days) was investigated. Three days following
the administration of the high dose of cocaine (35 mg/kg) a marked augmentation
in cocaine-induced horizontal and vertical activities was observed (induction
phase). Subsequently, after 10 days of cocaine administration, mice developed
stage 5 seizures (Racine scale). Binding of [3H]CGP 39653 to the NMDA receptors
revealed a marked increase in receptor densities in the striatum, amygdala and
hippocampus associated with the induction phase. The elevation of NMDA receptor
binding in the striatum and amygdala was sustained for 10 days following the
induction phase. The pattern of altered NMDA receptor binding following the
expression of cocaine kindled seizures was different. One day after the
expression of kindled seizures NMDA receptor binding was elevated in striatum,
amygdala, hippocampus and frontal cortex. However, only the elevation of NMDA
receptor binding in the amygdala and hippocampus was sustained for 10 days
following the expression of cocaine kindled seizures. In the brains of mice
sensitized to the low dose of cocaine (15 mg/kg) no change in NMDA receptor
binding was observed compared with control values. The present findings suggest
the following: (a) The induction of cocaine kindling is associated with increased
NMDA receptor binding activity in the striatum, amygdala and hippocampus; (b) the
maintenance of cocaine kindling depends on increased NMDA receptor binding in the
amygdala and hippocampus; (c) sensitization to cocaine-induced horizontal
locomotor activity may be independent of elevation in NMDA receptor binding.
PMID- 10665818
TI - Taurine-induced synaptic potentiation: role of calcium and interaction with LTP.
AB - Taurine induces a long-lasting potentiation of excitatory synaptic potentials due
to the enhancement of both synaptic efficacy and axon excitability in the CA1
area of rat hippocampal slices. In this study, we characterized the role of Ca2+
in the generation of these long-lasting taurine effects. Taurine perfusion in a
free-Ca2+ medium did not induce changes in either field excitatory synaptic
potentials (fEPSP) slope or fiber volley (FV) amplitude. Intracellular recordings
with a micropipette filled with the Ca2+ chelator BAPTA, prevented the EPSP
potentiation induced by taurine in the impaled cell, whereas a long-lasting
potentiation of the simultaneously recorded fEPSP was obtained. The depletion of
intracellular Ca2+ stores by thapsigargin (1 microM), an inhibitor of endosomal
Ca2+-ATPase, transformed the taurine-induced potentiation into a transitory
process that declined to basal values after taurine withdrawal. Taurine-induced
potentiation was not significantly affected by kynurenate (glutamate receptor
antagonist), or nifedipine (high-voltage-activated Ca2+ channel antagonist). But,
the presence of nickel (50 microM), an antagonist of low-voltage-activated Ca2+
channel, inhibited the taurine-induced potentiation, indicating that Ca2+ influx
through this type of Ca2+ channels could account for the Ca2+ requirement of the
taurine-induced potentiation. Occlusion experiments between tetanus-induced long
term potentiation (LTP) and taurine-induced potentiation indicate that both
processes share some common mechanisms during the maintenance period.
PMID- 10665819
TI - Deduction of amino acid residues in the GABA(A) receptor alpha subunits
photoaffinity labeled with the benzodiazepine flunitrazepam.
AB - Peptide mapping and microsequencing were used to infer the site of photoaffinity
labeling by the gamma-aminobutyric acidA receptor modulator [3H]flunitrazepam.
Peptide mapping with and without N-deglycosylation was used to restrict the
domain for photoaffinity labeling to residues 74-123 of the bovine alpha1
subunit, in agreement with a previously predicted labeling domain between
residues 59-148 based on cyanogen bromide fragmentation. Edman degradation of
partially purified photolabeled peptides gave release of 3H counts in the ninth
cycle of a tryptic peptide sequence. A second V8/chymotryptic peptide produced an
impure sequence with release of 3H counts in the seventh through ninth cycle of
sequence. The combined data support those previously reported, i.e., that the
primary site for photoaffinity labeling by [3H]flunitrazepam is His102 of the
bovine alpha1 subunit. In addition we also detected possible secondary labeling
of Pro97.
PMID- 10665820
TI - Reversal of the activity-dependent suppression of GABA-mediated inhibition in
hippocampal slices from gamma-vinyl GABA (vigabatrin)-pretreated rats.
AB - The antiepileptic drug, gamma-vinyl GABA (GVG, vigabatrin), is an irreversible
inhibitor of GABA-transaminase, the enzyme responsible for the breakdown of GABA.
In hippocampal slices prepared from rats pretreated with either an anticonvulsant
dose of GVG (1500 mg/kg) or saline, electrophysiological recordings were
performed in order to examine the effects of GVG pretreatment on GABAergic
neurotransmission. Although GVG had no effect on the effectiveness of GABA
mediated inhibition when elicited by a single stimulus, it reversed the activity
dependent depression of inhibition which is typically observed when inhibitory
pathways are activated repetitively by a train of stimuli delivered at low
frequency. Similarly, GVG pretreatment prevented the progressive decline in the
amplitude of monosynaptic inhibitory postsynaptic potentials (IPSPs) during low
frequency stimulation of inhibitory interneurons. Thus, in slices from GVG
pretreated rats, the amplitudes of both the fast and slow components of the last
of a series of IPSPs evoked by a 5 Hz, 4 s train were maintained at 91.5 +/- 6.6%
and 87.7 +/- 6.5%, respectively, compared to 61.1 +/- 3.9% and 57.1 +/- 5.0% in
control slices. Finally, in slices from GVG pretreated rats, we observed a
reduction in the ability of the GABA(B) receptor agonist, baclofen, to decrease
the amplitude of monosynaptic inhibitory postsynaptic currents. These results
suggest that GVG may produce its frequency-dependent actions by reducing the
function of release regulating presynaptic GABA(B) autoreceptors. The frequency
dependent reinforcement of inhibition by GVG may importantly contribute to the
anticonvulsant effectiveness of this compound.
PMID- 10665821
TI - Dopaminergic behaviors and signal transduction mediated through adenylate cyclase
and phospholipase C pathways.
AB - We determined the relative effects of chemical receptor inactivation on
dopaminergic signaling through adenylate cyclase and phospholipase C pathways and
evaluated the behavioral implications of such receptor manipulations. Groups of
rats were given intraperitoneal injections of 10 mg/kg N-ethoxycarbonyl-2-ethoxy
1,2-dihydroquinoline (EEDQ), a reagent that differentially inactivates
neurotransmitter receptors. Control and treated animals were used to assess
dopaminergic-mediated behaviors or brain tissues were prepared from the animals
and used to assay D1-like receptor binding and agonist-stimulated second
messenger formation. EEDQ decreased by 75% the number of D1-like binding sites
and completely abolished dopamine-stimulated cyclic AMP formation in striatal
membranes. Conversely, dopamine-stimulated phosphoinositide hydrolysis was
insensitive to inactivation by EEDQ as examined over different durations of EEDQ
treatment, in different brain regions, or with different concentrations of the D1
like receptor agonist SKF38393. EEDQ-pretreated animals lost their stereotypic
response to apomorphine but showed increased vacuous jaw movements in response to
apomorphine or SKF38393. Basal catalepsy was increased and SCH23390 was unable to
further enhance catalepsy beyond the basal levels in the lesioned animals. In
naive animals, SCH23390 catalepsy was reversed by apomorphine, and apomorphine
stereotypy was reversed by SCH23390. Taken together, the present results imply
that the dopamine-sensitive phospholipase C system mediates a subset of
dopaminergic behaviors, notably vacuous jaw movements, in contrast to stereotypy
and catalepsy which appear to be respectively mediated through stimulation and
inhibition of the adenylate cyclase-coupled dopaminergic system.
PMID- 10665822
TI - Striatal application of nicotine, but not of lobeline, attenuates dopamine
release in freely moving rats.
AB - We investigated the physiological role of native low- and high-affinity nicotinic
acetylcholine receptors (nAChRs) in regulating dopamine (DA) release from
striatal DA terminals. To evaluate the functional interactions of the two
receptor subtypes, nicotine (which interacts with both high- and low-affinity
nAChRs) and lobeline (which selectively interacts with high-affinity nAChRs) were
perfused through a microdialysis probe implanted into the striatum of freely
moving rats. The DA content of successive dialysates was quantified by HPLC with
an electrochemical detector. A short-lasting (1-min) perfusion of nicotine or
lobeline dose-dependently increased the DA content of striatal dialysates. A
second application of the same dose of nicotine resulted in an attenuated DA
increase, compared with the increase elicited by the first application; however,
the DA increase elicited by a second application of lobeline was similar to that
of the first lobeline application. The nicotine-induced response was not
attenuated when it followed a lobeline perfusion; in contrast, if the nicotine
perfusion preceded that of lobeline, the lobeline-induced response was
attenuated. In the presence of mecamylamine (a noncompetitive nAChR antagonist),
the increase in DA content of striatal dialysate samples induced by either
nicotine or lobeline was attenuated. However, in the presence of
methyllycaconitine (a preferential antagonist for low-affinity alpha7 homomeric
nAChRs), the nicotine response was attenuated but that of lobeline was
unaffected. These results suggest that the functional inactivation of striatal
nAChRs requires the simultaneous activation of both low- and high-affinity
nAChRs. Since lobeline is devoid of reinforcing properties, one might infer that
the reinforcing properties of nicotine require the simultaneous activation of
high- and low-affinity brain nAChRs.
PMID- 10665823
TI - Effects of tranylcypromine on thyroid hormone metabolism and concentrations in
rat brain.
AB - The effect of 14 days administration of the anti-depressant tranylcypromine (TCP)
on iodothyronine deiodinase activities and the concentrations of thyroxine (T4)
and triiodothyronine (T3) were investigated in homogenates of up to nine regions
of the rat brain. The activity of the 5III deiodinase isoenzyme, which catalyses
the inactivation of T3 to 3,3'-diiodothyronine (3,3'-T2), was enhanced in eight
brain regions. However, the brain levels of T4 were completely unchanged and the
T3 concentrations were significantly reduced in the frontal cortex only.
Therefore, we also measured the T3 concentrations of three subcellular fractions
(nuclei, synaptosomes and mitochondria) of six brain regions. TCP induced a
significant reduction in T3 levels in the synaptosomes of the frontal cortex and
significant increases in the mitochondrial T3 concentrations in the amygdala. The
latter effect was replicated after 14 days administration of 5 mg/kg desipramine.
No effects of either drug on nuclear concentrations of T3 were seen in any brain
region. As the amygdala is critically involved in the affective coloring of
sensory stimuli, the increase in T3 concentrations in the mitochondria of this
brain region may be of relevance for the mechanism of action of anti-depressant
drugs.
PMID- 10665824
TI - Differential adaptation of brain 5-HT1A and 5-HT1B receptors and 5-HT transporter
in rats treated chronically with fluoxetine.
AB - Quantification of receptor binding sites and their encoding mRNAs, and
electrophysiological recordings, were used to assess central serotonin (5-HT)
neurotransmission in rats 24 h after a 2-3 week treatment with the selective 5-HT
reuptake inhibitor fluoxetine (8 mg/kg i.p., daily). Binding studies showed that
this treatment affected neither 5-HT1A nor 5-HT1B binding sites in all brain
areas examined. However, a significant decrease (-38%) in 5-HT1A mRNA levels in
the anterior raphe area (but not forebrain regions) and increases in 5-HT1B mRNA
levels in the striatum (+127%) and the cerebral cortex (+34%) were noted in
fluoxetine-treated rats. Electrophysiological recordings in brain slices showed
that chronic fluoxetine treatment reduced the potency of the 5-HT1A agonist 8
hydroxy-2-(di-n-propylamino)tetralin to inhibit neuronal activity in the dorsal
raphe nucleus, but did not affect 5-HT1A-evoked responses of CA1 pyramidal cells
in the hippocampus. These data further demonstrate that fluoxetine-induced
adaptive changes in 5-HT neurotransmission exhibit marked regional differences.
The decrease in 5-HT1A mRNA levels in the anterior raphe suggests that fluoxetine
induced desensitization of 5-HT1A autoreceptors involves changes at the
transcription level.
PMID- 10665825
TI - Immunohistochemical localisation of the 5-HT2C receptor protein in the rat CNS.
AB - 5-HT2C receptor mRNA has a widespread distribution in the human and rat CNS but
the absence of a specific high affinity ligand has made autoradiographic
localisation of the receptor difficult. By raising polyclonal antibodies against
the rat 5-HT2C receptor protein this study reports the immunohistochemical
distribution of this receptor in the rat CNS. A sephadex purified 5-HT2C
antiserum visualised a single immunopositive band (54 kDa) in Western blots of
membranes prepared from several rat brain regions and caused intense membrane
immunofluorescence in HEK 293 cells transfected with h5-HT2C cDNA, which were
both attenuated by incubation with the antigenic peptide sequence (200-300
microM). 5-HT2C-like immunoreactivity was located on neurones throughout the CNS.
The most abundant 5-HT2C-like immunoreactive cell bodies were in the anterior
olfactory nucleus, medial and intercalated amygdaloid nuclei, hippocampus layers
CA1 to CA3, laterodorsal and lateral geniculate thalamic nuclei, caudate-putamen
and several areas of the cortex (including piriform and frontal), consistent with
this receptor being located postsynaptic to serotonergic neurones. Immunopositive
neurones were also found in the dorsal raphe, suggesting that 5-HT2C receptors
may be on some serotonergic neurones. The overall distribution of 5-HT2C-like
immunoreactivity complements previous findings with conventional radioligands and
agrees well with reported levels of 5-HT2C receptor mRNA.
PMID- 10665826
TI - The involvement of tachykinin NK2 and NK3 receptors in central sensitization of a
spinal withdrawal reflex in the decerebrated, spinalized rabbit.
AB - Repetitive electrical stimulation of the sural nerve at a strength sufficient to
excite C-fibres results in prolonged (> 20 min) increases in the reflex responses
of gastrocnemius motoneurones evoked by stimulation of myelinated axons in the
sural nerve. We have tested the susceptibility of this effect to blockade of
tachykinin NK2 and NK1 receptors. In the control state, iterative stimulation of
sural nerve C fibres increased gastrocnemius reflexes to a peak of between 200
and 400% of pre-stimulus levels, an effect that recovered to baseline values over
23-30 min. Pre-treatment with selective antagonists for NK2 (SR 48968, 1 mg/kg
i.v.) or NK3 (SR 142801, 0.1 and 1 mg/kg i.v.) receptors failed to alter the peak
facilitation resulting from sural nerve stimulation. However, both drugs
significantly reduced the duration of enhancement of reflexes, to 18 min after SR
48968 and to 5 min after SR 142801. The inactive enantiomers of these compounds
(SR 48965 and SR 142806, both 1 mg/kg i.v.) did not reduce facilitation of
reflexes after sural nerve stimulation. We conclude that activation of tachykinin
NK3 receptors is a major factor in maintaining central sensitization of the sural
gastrocnemius reflex after electrical stimulation of sural nerve C-fibres. The
effects of SR 48968 were surprisingly weak and may have resulted from an effect
of this compound at NK3 receptors.
PMID- 10665827
TI - NK3 receptor blockade prevents hyperalgesia and the associated spinal cord
substance P release in monoarthritic rats.
AB - Previous studies in vitro have shown that NK3 receptors exist on primary afferent
terminals in rat spinal cord and mediate potentiation of the depolarisation
evoked substance P (SP) release. In the present study we have investigated the
role of the NK3 receptor-mediated SP release system in a model of inflammatory
pain. Monoarthritis was induced in rats by unilateral injection of complete
Freund's adjuvant (CFA); withdrawal latencies to a thermal stimulus were
subsequently measured at various times following CFA. The CFA-treated paw
displayed hyperalgesia as early as 4 h after CFA injection and hyperalgesia was
maintained until day 4 but had disappeared by day 21. The thermal hyperalgesia
was associated with an increase in basal SP release from spinal cord
synaptosomes. The possible involvement of endogenous neurokinin B acting at NK3
receptors was tested by using SB 223412-A [(S)-(-)-N-(alpha-ethylbenzyl)-3
hydroxy-2-phenylquinoline-4-carbo xamide hydrochloride], a novel, potent (Ki=30
nM) and selective (Ki>10,000 nM for NK1 and NK2 receptors), non-peptidic NK3
receptor antagonist. In vitro SB 223412-A antagonised the potentiation of SP
release produced by senktide in spinal cord synaptosomes. Administered
systemically to monoarthritic rats (50 mg/kg, p.o., b.i.d., for 4 days), the NK3
receptor antagonist SB 223412-A significantly reduced thermal hyperalgesia and
normalised the basal release of SP from spinal cord synaptosomes. The data
suggest that neurokinin B acting at NK3 receptors that mediate SP release within
the spinal cord play a role in inflammation. These NK3 receptors may represent,
therefore, appropriate targets in the therapy of inflammatory pain.
PMID- 10665828
TI - U50,488 protection against HIV-1-related neurotoxicity: involvement of quinolinic
acid suppression.
AB - The pathogenesis of human immunodeficiency virus type 1 (HIV-1) encephalopathy
has been associated with multiple factors including the neurotoxin quinolinate
(an endogenous N-methyl-D-aspartate [NMDA] receptor ligand) and viral proteins.
The kappa opioid receptor (KOR) agonist U50,488 recently has been shown to
inhibit HIV-1 p24 antigen production in acutely infected microglial cell
cultures. Using primary human brain cell cultures in the present study, we found
that U50,488 also suppressed in a dose-dependent manner the neurotoxicity
mediated by supernatants derived from HIV-1-infected microglia. This
neuroprotective effect of U50,488 was blocked by the KOR selective antagonist nor
binaltorphimine. The neurotoxic activity of the supernatants from HIV-1-infected
microglia was blocked by the NMDA receptor antagonists 2-amino-5
phosphonovalerate and MK-801. HIV-1 infection of microglial cell cultures induced
the release of quinolinate, and U50,488 dose-dependently suppressed quinolinate
release by infected microglial cell cultures with a corresponding inhibition of
HIV-1 p24 antigen levels. These findings suggest that the kappa opioid ligand
U50,488 may have therapeutic potential in HIV-1 encephalopathy by attenuating
microglial cell production of the neurotoxin quinolinate and viral proteins.
PMID- 10665829
TI - The role of new anesthetic agents.
AB - The three anesthetic drugs introduced most recently to the market are
sevoflurane, desflurane, and ropivacaine. Sevoflurane and desflurane are both
inhalational anesthetic agents and ropivacaine is a local anesthetic agent.
Sevoflurane provides a rapid onset and offset of action; it is well tolerated
with little airway irritation. It is hemodynamically stable, with low potential
for toxicity. Concerns about its interaction with soda lime during low-flow
anesthesia with the production of Compound A have not proved to be a clinical
problem. While desflurane also provides rapid onset and recovery from anesthesia,
it is not as hemodynamically stable as sevoflurane, and also causes airway
irritation. Ropivacaine is a unique local anesthetic in that it is supplied as
the pure S-enantiomer. It is at least as effective as bupivacaine, with lower
toxicity and less motor block for the same degree of sensory block.
PMID- 10665830
TI - Vascular sodium pump: endothelial modulation and alterations in some pathological
processes and aging.
AB - The vascular Na+ pump maintains intracellular ionic concentration and controls
membrane potential. Its inhibition by cardiac glycosides enhances the
intracellular Na+ concentration. This in turn activates the Na+-Ca2+ exchange
mechanism, which induces intracellular Ca2+ increase, membrane depolarization,
and noradrenaline release from perivascular adrenergic nerve endings; mechanisms
that promote vasoconstriction. This article reviews the relevance of the Na+ pump
in vascular tone regulation and the modulation of its activity by the
endothelium. The endothelium negatively modulates the vasoconstriction elicited
by Na+ pump inhibition by the release of nitric oxide, according to some authors,
or an unknown factor, as suggested by others. The possible existence of
endogenous digitalis-like factors is also reviewed, as is the involvement of the
vascular Na+ pump in some cardiovascular disorders and aging.
PMID- 10665831
TI - General overview of mineralocorticoid hormone action.
AB - The adrenal cortex elaborates two major groups of steroids that have been
arbitrarily classified as glucocorticoids and mineralocorticoids, despite the
fact that carbohydrate metabolism is intimately linked to mineral balance in
mammals. In fact, glucocorticoids assured both of these functions in all living
cells, animal and photosynthetic, prior to the appearance of aldosterone in
teleosts at the dawn of terrestrial colonization. The evolutionary drive for a
hormone specifically designed for hydromineral regulation led to zonation for the
conversion of 18-hydroxycorticosterone into aldosterone through the catalytic
action of a synthase in the secluded compartment of the adrenal zona glomerulosa.
Corticoid hormones exert their physiological action by binding to receptors that
belong to a transcription factor superfamily, which also includes some of the
proteins regulating steroid synthesis. Steroids stimulate sodium absorption by
the activation and/or de novo synthesis of the ion-gated, amiloride-sensitive
sodium channel in the apical membrane and that of the Na+/K+-ATPase in the
basolateral membrane. Receptors, channels, and pumps apparently are linked to the
cytoskeleton and are further regulated variously by methylation, phosphorylation,
ubiquination, and glycosylation, suggesting a complex system of control at
multiple checkpoints. Mutations in genes for many of these different proteins
have been described and are known to cause clinical disease.
PMID- 10665832
TI - New approaches to rational drug design.
AB - Rational drug design has emerged as a powerful technique. In this review, three
new developments in rational drug design are explored. These developments include
new methods to find binding sites for small molecules on the surface of a
protein, the suggestion that the protein environment may change the shape of a
protein sufficiently to alter drug design, and the use of data emerging from
structural genomics in drug design. Although these are three new and distinct
areas, the insights derived from these studies suggest a reason for the
observation that similar drugs do not always bind to a protein in the same
manner.
PMID- 10665833
TI - The contribution of electrophysiology to knowledge of the acute and chronic
effects of ethanol.
AB - This review describes the effects of ethanol on the components of neuronal
transmission and the relationship of such effects to the behavioural actions of
ethanol. The concentrations of ethanol with acute actions on voltage-sensitive
ion channels are first described, then the actions of ethanol on ligand-gated ion
channels, including those controlled by cholinergic receptors, 5
hydroxytryptamine receptors, the various excitatory amino acid receptors, and
gamma-aminobutyric acid receptors. Acute effects of ethanol are then described on
brain areas thought to be involved in arousal and attention, the reinforcing
effects of ethanol, the production of euphoria, the actions of ethanol on motor
control, and the amnesic effects of ethanol; the acute effects of ethanol
demonstrated by EEG studies are also discussed. Chronic effects of alcohol on
neuronal transmission are described in the context of the various components of
the ethanol withdrawal syndrome, withdrawal hyperexcitability, dysphoria and
anhedonia, withdrawal anxiety, craving, and relapse drinking.
Electrophysiological studies on the genetic influences on the effects of ethanol
are discussed, particularly the acute actions of ethanol and electrophysiological
differences reported in individuals predisposed to alcoholism. The conclusion
notes the concentration of studies on the classical transmitters, with relative
neglect of the effects of ethanol on peptides and on neuronal interactions
between brain areas and integrated patterns of neuronal activity.
PMID- 10665834
TI - Superoxide in the pulmonary circulation.
AB - Superoxide formation in pulmonary tissue is modulated by cytokines, PO2, shear
force, and disease states, and can be stimulated by drugs. Superoxide has diverse
actions on pulmonary cells, including smooth muscle contraction, interaction with
redox enzymes, cell proliferation, and gene transcription. In the lungs, there is
an impressive array of specific defence mechanisms that destroy superoxide,
especially superoxide dismutase (SOD) and metallothionein. Superoxide formation
is increased in hyperoxia (e.g., oxygen therapy); however, superoxide-forming
enzymes also can be up-regulated in hypoxia. Superoxide has been implicated in
acute respiratory distress syndrome, lung ischaemia-reperfusion injury, and lung
transplantation. Novel approaches to therapy have been explored, including SOD
gene therapy and SOD targeting to the lung. In the future, new drugs interacting
with superoxide may provide significant advances in the treatment of lung
diseases.
PMID- 10665835
TI - Unusual transcriptional and translational regulation of the bacteriophage Mu mom
operon.
AB - The bacteriophage Mu mom gene encodes a novel DNA modification that protects the
viral genome against a wide variety of restriction endonucleases. Expression of
mom is subject to a series of unusual regulatory controls. Transcription requires
the action of a phage-encoded protein, C, which binds (probably as a dimer) the
mom promoter from -33 to -52 (with respect to the transcription start site) in
two adjacent DNA major grooves on one face of the helix. No apparent direct
interaction between C and the host RNA polymerase (RNAP) is evident; however, C
binding alters mom DNA conformation. In the absence of C, RNAP binds the mom
promoter at a site that results in transcription in a direction away from the mom
gene. The function of this transcription is unknown. An additional layer of
transcriptional regulation complexity is due to the fact that the host Dam DNA
(N6-adenine)methyltransferase is required. Dam methylation of three closely
spaced upstream GATC sequences is necessary to prevent binding by the host
protein, OxyR, which acts as a repressor. Repression is not mediated by
inhibition of C binding, but rather through interference with C-mediated
recruitment of RNAP to the correct site. Translation of mom is regulated by the
phage Com protein. Com is only 62 amino acids long and contains a zinc finger
like structure (coordinated by four cysteine residues) in the amino terminal
domain. Com binds mom mRNA 5' to the mom open reading frame, whose translation
start signals are contained in a stem-loop translation-inhibition-structure. Com
binding to its target site (5' to and adjacent to the translation-inhibition
structure) results in a stable change in RNA secondary structure that exposes the
translation start signals.
PMID- 10665836
TI - DNA methylation analysis: a review of current methodologies.
AB - The relationship between levels of DNA methylation and gene activity has been
known for some time. Many of the early procedures developed gave only somewhat
limited information about methylation patterns, for example, the total level of 5
methyl cytosine in the genome or the frequency of methylation of cytosines within
certain restriction sites. However, in the last few years, there has been an
explosion of interest in DNA methylation, and with it, many new and powerful
techniques have been developed to facilitate its study. In this paper, the key
techniques currently available are reviewed and the advantages, disadvantages,
and potential artifacts of each are discussed.
PMID- 10665837
TI - Nitric oxide in the lung: therapeutic and cellular mechanisms of action.
AB - Nitric oxide is produced by many cell types in the lung and plays an important
physiologic role in the regulation of pulmonary vasomotor tone by several known
mechanisms. Nitric oxide stimulates soluble guanylyl cyclase, resulting in
increased levels of cyclic GMP in lung smooth muscle cells. The gating of K+ and
Ca2+ channels by cyclic GMP binding is thought to play a role in nitric oxide
mediated vasodilation. Nitric oxide may also regulate pulmonary vasodilation by
direct activation of K+ channels or by modulating the expression and activity of
angiotensin II receptors. Administration of nitric oxide by inhalation has been
shown to acutely improve hypoxemia associated with pulmonary hypertension in
humans and animals. This is presumably due to its ability to induce pulmonary
vasodilation. Inhaled nitric oxide improves oxygenation and reduces the need for
extracorporeal membrane oxygenation in term and near-term infants with persistent
pulmonary hypertension. However, long-term benefits to these infants have been
difficult to demonstrate. In other pathologic conditions, such as prematurity and
acute respiratory distress syndrome, short-term benefits have not been shown
conclusively to outweigh potential toxicities. For example, high-dose inhaled
nitric oxide decreases surfactant function in the lung. Inhaled nitric oxide also
acts as a pulmonary irritant, causing priming of lung macrophages and oxidative
damage to lung epithelial cells. Conversely, protective effects of nitric oxide
have been described in a number of pathological states, including hyperoxic and
ischemia/reperfusion injury. Nitric oxide has also been reported to protect
against oxidative damage induced by other reactive intermediates, including
superoxide anion and hydroxyl radical. The dose and timing of nitric oxide
administration needs to be ascertained in clinical trials before recommendations
can be made regarding its optimal use in patients.
PMID- 10665838
TI - New insights into the pharmacodynamic and pharmacokinetic properties of statins.
AB - The beneficial effects of statins are assumed to result from their ability to
reduce cholesterol biosynthesis. However, because mevalonic acid is the precursor
not only of cholesterol, but also of many nonsteroidal isoprenoid compounds,
inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase may result in
pleiotropic effects. It has been shown that several statins decrease smooth
muscle cell migration and proliferation and that sera from fluvastatin-treated
patients interfere with its proliferation. Cholesterol accumulation in
macrophages can be inhibited by different statins, while both fluvastatin and
simvastatin inhibit secretion of metalloproteinases by human monocyte-derived
macrophages. The antiatherosclerotic effects of statins may be achieved by
modifying hypercholesterolemia and the arterial wall environment as well.
Although statins rarely have severe adverse effects, interactions with other
drugs deserve attention. Simvastatin, lovastatin, cerivastatin, and atorvastatin
are biotransformed in the liver primarily by cytochrome P450-3A4, and are
susceptible to drug interactions when co-administered with potential inhibitors
of this enzyme. Indeed, pharmacokinetic interactions (e.g., increased
bioavailability), myositis, and rhabdomyolysis have been reported following
concurrent use of simvastatin or lovastatin and cyclosporine A, mibefradil, or
nefazodone. In contrast, fluvastatin (mainly metabolized by cytochrome P450-2C9)
and pravastatin (eliminated by other metabolic routes) are less subject to this
interaction. Nevertheless, a 5- to 23-fold increase in pravastatin
bioavailability has been reported in the presence of cyclosporine A. In summary,
statins may have direct effects on the arterial wall, which may contribute to
their antiatherosclerotic actions. Furthermore, some statins may have lower
adverse drug interaction potential than others, which is an important determinant
of safety during long-term therapy.
PMID- 10665839
TI - Fetal hepatic drug elimination.
AB - The majority of studies of fetal hepatic elimination have concentrated on the
expression and activity of the metabolizing enzymes, but the unique physiologic
milieu of the fetal liver should also be considered. The basic structure of the
liver is formed by the end of the first trimester. The fetal hepatic circulation
differs substantially from that of the adult in that there is an extra input
vessel, the umbilical vein, and there is shunting of 30-70% of hepatic blood flow
via the ductus venosus. The left and right lobes of the fetal liver seem to
function independently with respect to a variety of biochemical parameters, due
at least in part to the lower oxygen supply to the right lobe. The zonation of
drug-metabolizing enzymes along the hepatic acinus, which is prominent in the
adult liver, is absent in the fetal liver. Unlike rodent species, the human fetal
liver has a significant capacity for drug metabolism. Of the oxidative enzymes,
CYP3A7 accounts for up to 50% of total fetal hepatic cytochrome P450 content.
Expression of this enzyme decreases dramatically after birth. CYP1A1 and CYP2D6
have also been detected in human fetal liver, but whether CYP2E1 is expressed
remains controversial. Several other cytochrome P450s have been identified and
await characterization. Fetal hepatic drug conjugation may prolong fetal exposure
to the metabolites produced, which, being more water soluble, do not readily
cross the placenta back to the mother and, if excreted in fetal urine, can be
recycled in the fetus via amniotic fluid and fetal swallowing. Limited activity
of glucuronidation enzymes has been demonstrated in human fetal liver in contrast
to the activity of sulfation enzymes, which is significant. Limited in vivo
studies in fetal sheep have demonstrated significant fetal hepatic drug
elimination, and this has been confirmed in studies of the isolated perfused
fetal sheep liver. Our understanding of fetal hepatic elimination processes has
advanced steadily over the years. Future developments, however, should consider
more fully the influence of the unique physiological milieu of the fetal liver,
in addition to the expression and activity of drug metabolizing enzymes.
PMID- 10665840
TI - Tumor necrosis factor-alpha: molecular-biological aspects minireview.
AB - Tumor necrosis factor-alpha (TNF-alpha) a proinflammatory cytokine with multiple
actions was first identified for its anticancer activity. However, TNF-alpha has
a beneficial function in activation of host defense, its uncontrolled production
can lead to pathological consequences. At the cellular level, it is able to exert
obviously opposing effects: apoptosis and activation. It modulates survival and
activates genes through various intermediates, including protein kinases, protein
phosphatases, reactive oxygen intermediates, phospholipases, proteases,
sphingomyelinases and transcription factors. In this review, the INF-alpha is
characterized at the molecular and cellular level (TNF-alpha mediated signal
transduction is discussed in the first part, regulation of its expression in the
second one), as well as methods of its determination in biological materials,
giving special emphasis to the molecular-biological approach. The full
understanding of the molecular mechanism of TNF-alpha will provide the basis for
a pharmacological approach intended to inhibit or potentiate selected biological
actions of this cytokine.
PMID- 10665841
TI - Construction and testing of gene therapy retroviral vector expressing bacterial
cytosine deaminase gene.
AB - A retroviral vector containing gene for bacterial enzyme cytosine deaminase (CD)
under the control of viral LTR sequences was constructed and transfected into
packaging cell line GP+envAm12. High virus titer producing single cell clone (1 x
10(7) cfu/ml, determined on NIH 3T3 cells) was isolated and used to transfer CD
gene into human mammary carcinoma cell lines in vitro. Transduced cells exhibited
high sensitivity to the antifungal drug 5-fluorocytosine (5-FC), whereas parental
cells did not. Cocultivation of CD-positive and CD-negative parental cells showed
bystander effect, dependent on the ratio of CD-positive cells. No enhancement of
5-FC cytotoxicity by leucovorin was observed in cells expressing cytosine
deaminase.
PMID- 10665842
TI - Aberrant markers expression in T- and B-lymphoid and myeloid leukemia cells of
different differentiation stages.
AB - The aim of the study was to ascertain if in T acute lymphoblastic leukemia (T
ALL), B acute lymphoblastic leukemia (B-ALL) and acute myeloid leukemia (AML) of
different differentiation stages the coexistence of aberrant markers correlate
with the degree of leukemic blasts maturation. We evaluated the results of
surface and intracellular markers in 42 T-ALL, 86 B-ALL and 71 AML cases. A large
panel of monoclonal antibodies (MoAbs) against T-cell, B-cell, myeloid cell and
non-lineage specific structures has been used. Patients had dual-color flow
cytometric immunophenotyping performed by FACStar flow cytometer. The correct
immunological diagnosis of followed new cases before any treatment has been
performed and simultaneously the presence of atypical/aberrant phenotypes has
been studied and correlated with leukemia cells differentiation stage. A great
deal of T-ALL and AML, in opposite to B-ALL cases, revealed a high proportion of
atypical phenotypes (55, 75 and 36%, respectively), which are absent in
nonleukemic cells. We found out that these atypical phenotypes were present in T
ALL, AML (not clearly in B-ALL) through all differentiation stages and so we
obtained an evidence that they might represent an abnormal/atypical rather than
an immature phenotype, as it was postulated till now by several authors.
PMID- 10665843
TI - Angiogenesis inhibitor TNP-470: cytotoxic effects on human neoplastic cell lines.
AB - Angiostatic substance TNP-470 displayed moderate cytotoxicity towards human
leukemia HL-60, HL-60/ADR, HL-60/VCR and myeloma ARH77 cell lines with IC50 in
the range 5-10 microM of concentrations and slightly higher IC50 for myeloma cell
line U266. IC50 for ovarian CH-1, A2780 and A2780/ADR cell lines was in the range
10-15 microM with the exception of platinum-resistant SKOV3 cell line (more than
40 microM ). The IC50 values for MDA-MB-231 and MCF-7 breast carcinoma cell lines
were 15 and 25 microM, respectively. In human hemopoietic neoplastic cell lines
examined, TNP-470 induced the appearance of subpopulation with sub-G0 DNA
content, suggesting the apoptosis-inducing potential of TNP-470 in these cells.
No TNP-470-induced drug uptake modulation in drug-resistant leukemia cell line HL
60/VCR was observed. TNP-470 induced accumulation of cells in G0/G1 phase of cell
cycle. There was no TNP-470-induced inhibition of MMP collagenase activity or MMP
(MMP2 and MMP9) production in the human fibrosarcoma cells HT 1080 in vitro.
PMID- 10665844
TI - Characterization of APC exon 15 germ-line mutation in FAP family with severe
phenotype showing extracolonic symptoms.
AB - The adenomatous polyposis coli (APC) gene plays a crucial role in colorectal
carcinogenesis. Germ-line mutations of APC gene give rise to familial adenomatous
polyposis coli (FAP) - autosomal dominant syndrome manifesting hundreds to
thousands of colorectal polyps, if untreated with malignant progression. We have
used the techniques of heteroduplex analysis (HDA), protein truncation test
(PTT), single strand conformation polymorphism (SSCP) and DNA sequencing for the
identification and detailed positional analysis of mutations in IFAP family with
the expressive phenotype characterized by polyposis and extracolonic lesions.
Detailed analysis revealed a 5bp deletion in a mutation cluster region (MCR) in
exon 15 of APC gene in codon 1308. Two screened members of the FAP family
exhibited this novel mutation.
PMID- 10665845
TI - A note on nucleoli in granulocytic precursors of the granulopoietic proliferating
compartment in patients suffering from the chronic phase of chronic myeloid
leukemia treated with two different drugs with different mode of action.
AB - The incidence of main nucleolar types in granulocytic precursors was studied in
the granulopoietic proliferating compartment (GPC) of patients suffering from
chronic phase of the chronic myeloid leukemia (CML) who were treated by the
widely used therapy with two different drugs with different mode of action -
hydroxyurea (HU) and interferon alpha (IFN-alpha). In comparison with IFN early
stages of GPC, i.e. myeloblasts and promyelocytes in patients treated with HU
possessed more frequently micronucleoli which are known to reflect the direct as
well as indirect inhibition of the nucleolar biosynthetic activities. On the
other hand, the incidence of micronucleoli in these cells of a small percentage
of patients treated with IFN also reached the average values of these nucleoli
which were noted in patients treated with HU.
PMID- 10665846
TI - Expression of CD26 and DPP IV in T-acute lymphoblastic leukemia: comparison of
immunocytochemistry with enzyme cytochemistry.
AB - Tile possible identity ofdipeptidyl peptidase IV (DPP IV) enzymatic activity and
CD26 antigen expression in phenotypically defined T-acute lymphoblastic leukemia
cells (T-ALL) was examined. For comparative studies, the combination of
immunocytochemistry and enzyme cytochemistry methods was used. T he strong
correlation between the CD26 antigen expression and DPP IV positivity in the
majority of T-lymphoblasts in T-ALL patients was evident. No CD26 antigen was
expressed on DPP IV negative T-cells. The variable CD4 and/or CD8 antigen
expression, frequent CD5 and CD7 positivity and absence of surface membrane CD3
antigen were the characteristic immunophenotypic features of CD26/DPP IV positive
T-lymphoblasts. Moreover, the clear CD71 and CD26/DPP IV coexpression suggested
the association of CD26/DPP IV positive cells with proliferation. The
immunophenotype of CD26/DPP IV positive T-lymphoblasts seems to be characteristic
for the relative immature cell population. In addition, noteworthy was the slight
disassociation between the very high CD26 antigen expression and moderate DPP IV
activity in cells of some T-ALL patients. The possible existence of enzymatically
inactive structures of CD26 antigen or inactive precursors of DPP IV detectable
only by immunocytochemistry was discussed. Our study indicates that CD26 antigen
expression is tended to identify cells with DPP IV enzymatic activity in T-ALL
patients. The results provide some more information of CD26 antigen involvement
in the pathology of leukemic cells via its DPP IV enzyme activity.
PMID- 10665847
TI - Comparison of antileukemic immunity against U937 cells in atopic asthmatics
versus healthy controls.
AB - To assess the antitumor effects in atopic asthmatics versus healthy adults, we
designed this study using in vitro mononuclear cells (MNC) culture as an immunity
model with human leukemic U937 cells as the target. MNCs were collected from
asthmatic subjects and healthy controls. Conditioned media from the MNC cultures
(MNC-CM) were collected after stimulation with various concentrations of
phytohemagglutinin (PHA). We treated U937 cells with these MNC-CMs, then assayed
their proliferation and differentiation after 5 days of culture. At lower PHA
doses (1.25 microg/ml), as well as in absence of PHA, the asthmatic MNC-CMs
inhibited U937 cells growth to a slightly greater extent than did the MNC-CMs
from controls. In contrast, when higher doses of PHA were used (5, 10 microg/ml),
this growth-inhibiting effect was dramatically reversed. The dual effect of MNC
CM in these two groups was also shown in U937 cell differentiation assay,
assessed as follows: morphological change by Liu's staining, functional change by
NBT reduction test and CD 14 expression by flow cytometric detection. We suggest
that the antileukemic effects of MNCs from asthmatic patients result from a
slightly immunopotentiated status. This immunity may be dramatically reversed,
however, after marked activation of MNCs.
PMID- 10665848
TI - Metastasis as the first sign of thyroid cancer.
AB - The aim of this paper is to review our experience with patients who presented
with a metastatic tumor in the lymph nodes or other organs as the first sign of
thyroid cancer. In 1974-1998, 18 602 patients were operated on due to goitre.
There were 975 (5.2%) patients with thyroid malignant neoplasms. The group
comprised 449 (46.1%) patients with papillary carcinoma, 309 (31.7%) with
follicular carcinoma, 54 (5.5%) with medullary carcinoma, 106 (10.9%) with
anaplastic carcinoma, and 57 (5.8%) with other types of thyroid malignant
neoplasms. Out of these 975 patients, thyroid cancer was diagnosed on the basis
of the detection of a metastatic tumor in 26 (2.7%) patients. In 16 (61.5%) of
these patients the metastatic tumor was located in the regional lymph nodes. In
10 (38.5%) patients distant metastasis beyond the regional lymph nodes was the
first sign of thyroid cancer. In (50%) patients metastasis was located in the
bones, in 2 (20%) in the lung, in 1 (10%) in the heart, in 1 (10%) in the
buttock, and in 1 (10%) in a central neck cyst. Metastasis was the initial
manifestation of thyroid cancer in 18 (4%) of 449 papillary carcinoma patients,
in 6 of 309 (1.9%) follicular carcinoma patients, and in 2 (3.7%) of 54 medullary
carcinoma patients. Lymph node metastasis was the first sign of thyroid cancer in
13 (2.9%) patients with papillary carcinoma, 1 (0.3%) patients with follicular
carcinoma and in 2 (3.7%) medullary carcinoma patients, and distant metastasis in
5 (1.1%) patients with papillary carcinoma and in 5 (1.6%) patients with
follicular carcinoma. After the detection of the primary focus of thyroid cancer
total thyroidectomy and modified neck dissection were performed in all patients.
Differentiated thyroid carcinoma patients were treated complementarily with 131I
and TSH suppressive doses of L-thyroxine, and medullary cancer patients with
teleradiotherapy and substitutive doses of L-thyroxine.
PMID- 10665849
TI - Osteoblasts and osteoclasts in bone marrow smears of cancer patients.
AB - Osteoblasts and osteoclasts are the unique cells occurring in bone marrow smears
in situations with high bone metabolic turnover (children, trauma, rachitis,
Paget disease or tumors). The collection of 2706 sternal or iliac crest aspirates
from patients with hematologic malignancies and solid tumors are presented. We
demonstrated significantly higher positivity for osteoblasts-osteoclasts
presentation in bone marrow smears for hematological malignancies (p < 0.05),
solid tumors (p < 0.01), and especially breast cancer (p < 0.001). We found a
significant association between osteoblast-osteoclast positivity and
dissemination of breast cancer (p < 0.05). None of the breast cancer patients
without signs of dissemination (X-ray, sonography or scintigraphy) had positivity
for osteoblasts or osteoclasts. We suppose that the osteoblast-osteoclast
positivity in bone marrow smears can serve as a cheap marker for breast cancer
dissemination.
PMID- 10665850
TI - Clodronate in the management of bone metastases: a clinical study of 91 patients.
AB - The aim of our study was to evaluate the efficacy of oral clodronate
supplementing systemic therapy and/or palliative irradiation in 91 patients with
painful bone metastases. Clodronate was administered at a daily dose of 1600-3200
mg for a median of 11 months (range 3--36 months). Partial or complete pain
relief was achieved in 61 of 88 evaluable patients (69%). Response rate to
clodronate in patients who additionally received palliative bone radiation was
similar to that in patients who did not receive irradiation (68 and 71%,
respectively). Eleven out of 12 bed-ridden patients with metastatic bone pain
regained the ability of walking after the treatment with clodronate. Bone pain
relief lasted from 1.5 to 36 months (mean 9.3 months). Clodronate was well
tolerated in all but three cases (3%) in whom the treatment was discontinued due
to intensive adverse gastrointestinal effects. In conclusion, we observed
satisfactory symptomatic effect and low rate of adverse reactions in patients
with metastatic bone lesions treated with oral clodronate. Further large
controlled studies with thorough patient monitoring are warranted to evaluate the
real benefit of clodronate, and to define its optimal scheduling.
PMID- 10665851
TI - Quantitative analysis of modes of invasion and lymph node metastases in oral
squamous cell carcinoma.
AB - The mode of tumor invasion has been suggested to have a relationship to the
occurrence of cervical metastasis and to prognosis in oral squamous cell
carcinoma (OSCC). However, a tumor usually does not have a single mode of
invasion, and the importance, if any, of the relative proportions of different
modes for metastatic potential has not been studied. Forty two cases of OSCC
resected with cervical lymph nodes were selected, 20 of which had nodal
metastases and 22 which had not. The mode of invasion in the tumor-host interface
was classified as: I - pushing borders, II - bands, III - thin cords, IV - single
cells and analyzed in 20 consecutive medium power fields. Also studied were other
morphological parameters: perineural and angiolymphatic invasion, tissue
eosinophilia, mitosis and intensity of inflammatory infiltrate at the tumor-host
interface. The majority of the cases (95.2%) showed two or more modes of
invasion. Modes I, II and III occurred with similar frequency in cases with and
without metastases. Mode II was the commonest and most extensive in both groups.
No mode of invasion was significantly associated with metastases, independent of
its extension. The other morphological parameters were neither significantly
associated with cervical metastasis. In conclusion, OSCC usually shows two or
more modes of tumor invasion if a large extension of tumor-host interface is
analyzed. However, the relative proportions of the modes have no correlation with
the metastatic potential.
PMID- 10665852
TI - Cancer prevalence in Italian cancer registry areas: the ITAPREVAL study.
ITAPREVAL Working Group.
AB - AIM: To present data on cancer prevalence for the areas covered by Italian cancer
registries, by using a standardized set of data collection and elaboration
criteria, and a single method of data analysis. SUBJECTS AND METHODS: Data on
over 250,000 patients with cancer, diagnosed between 1978 and 1992, from 11
Italian cancer registries covering about 12% of the Italian population were
collected, validated and analyzed according to the unified protocol of the
ITAPREVAL project. The method implemented in the PREVAL computer program was used
to provide prevalence estimates for the period covered by cancer registration.
The total prevalence for each registry and for the pool of all registries was
then estimated by correcting for incomplete observations due to the period in
which the registration was not yet activated. All prevalence estimates were for
1992. RESULTS: Prevalence figures are presented by cancer site, age, sex, years
from diagnosis and registry area. For all malignancies combined, total prevalence
ranged from 1,350 per 100,000 inhabitants in Ragusa to 3,650 per 100,000
inhabitants in Romagna, the ratio between these two extremes being 2.7. For the
pool of the areas covered by registration cancer prevalence was 3,100 per 100,000
females and 2,250 per 100,000 males. About a third of the total female cases and
about half the male cases were diagnosed in the previous five years. Among those
aged over 75 years, total prevalence was higher for males than for females:
11,300 versus 8,900 per 100,000 respectively. CONCLUSIONS: This is the first
large-scale estimate of the burden of cancer in Italy. It is also one of the
first studies in the world which was aimed to study cancer prevalence in detail.
These data are necessary for predicting health service needs and help in the
evaluation of differences in health service demand by sex, age and Italian
regions.
PMID- 10665853
TI - Correcting the completeness bias of observed prevalence.
AB - AIMS AND BACKGROUND: The cancer prevalence in given areas can be estimated on the
basis of data supplied by cancer registries. As the obtained estimate of
prevalence depends on the length of the cancer registry's observation period, it
is generally lower than the total prevalence in the considered area. In the
present work we propose a method to calculate a correction factor of this bias in
order to obtain an approximation to the total prevalence. METHODS & STUDY DESIGN:
The method is based on the relationship between relative survival and incidence
by age for a specific cancer site. RESULTS AND CONCLUSIONS: We provide values of
the correction factor, the completeness index R, relative to the most important
cancer sites, for specific ages and periods of observation of the cancer
registries in Italy. In addition, we provide indications for extended use of the
index when substantial variations from the basic pattern of relative survival are
observed in practical situations. Furthermore, we give helpful suggestions to
obtain approximate values of the correction factor to be used for ages and
periods of observation that are intermediate between the ones presented in this
paper.
PMID- 10665854
TI - The prevalence of tumors of the breast and female genital tract in Italy.
AB - Data from 10 Italian population-based cancer registries were used to estimate the
prevalence of female tumors of the breast and genital tract. The total
prevalence, expressed in number per 100,000, was highest for breast cancer
(1,117), followed by cancer of the corpus (264) and cervix uteri (146), ovary
(110), and vagina and vulva (23). For all tumors the prevalence increased with
age at diagnosis. The cancer prevalence was divided into intervals from
diagnosis, expressing different health needs in terms of therapy and intensity of
clinical follow-up. For all tumors considered, 1-year prevalence was higher than
1-2-year prevalence, reflecting a high death risk due to perioperative mortality
and to the proportion of patients diagnosed at advanced stages. The prevalence
decreased in the following intervals considered. Noticeable geographic
variability was observed in the prevalence across Italy, with higher proportions
being registered in the northern-central regions than in the South. The two
extreme 0-5-year prevalence figures (per 100,000) were: for breast cancer 568
(Genova) and 259 (Ragusa); for corpus uteri cancer 94 (Romagna) and 21 (Latina);
for cervix uteri cancer 63 (Romagna) and 26 (Latina); for ovarian cancer 49
(Parma) and 21 (Latina); for cancer of the vagina and vulva 17 (Genova) and 5
(Ragusa). This variability depends mainly on incidence and on the proportion of
elderly in the general population. From 1987 to 1992 there was an increase in the
prevalence of tumors of the breast, ovary and vagina and vulva, especially in the
elderly. The prevalence of corpus uteri cancer decreased slightly in the elderly
only, whereas that of cervix uteri cancer decreased at all ages.
PMID- 10665855
TI - The prevalence of colorectal cancer in Italy.
AB - AIMS: To analyze the prevalence of colorectal cancer (CRC) in different areas of
Italy by age, interval since diagnosis and disease stage at diagnosis, and to
estimate the prevalence of CRC. These data provide estimates of patient demand on
health resources. PATIENTS AND METHODS: Eleven Italian cancer registries (CRs)
provided data on 33,740 patients observed for up to 15 years. For the 1,829 cases
from the specialized colorectal cancer registry of Modena we analyzed prevalence
by Dukes' stage and family history. PREVAL software produced observed prevalence
figures by time from diagnosis; to determine the total prevalence, correction
factors were applied to the observed data. RESULTS: At the end of 1992, five-year
CRC prevalence was high (close to 200 per 100,000) in Genova, Parma, Romagna and
Firenze, and low (around 75 per 100,000) in the southern areas of Latina and
Ragusa. For all CRs, 86 patients per 100,000 population were alive up to 2 years
from diagnosis and 77 per 100,000 between 2 and 5 years from diagnosis. The 5
year prevalence of patients diagnosed with Dukes' B or C (high risk of recurrence
and requiring postoperative surveillance) was 152 per 100,000; that of Dukes' A
patients 36 per 100,000 (considered cured after surgery and not requiring
intensive follow-up or care); that of unstaged patients plus those with distant
metastasis at diagnosis was 28 per 100,000 at 5 years (requiring palliative care
but not follow-up). The 12-year prevalence of HNPCC was 23 per 100,000, or about
7% of the total; for such patients knowledge of the long-term prevalence is
important because they are diagnosed young and are at high risk of multiple tumor
development. CONCLUSIONS: 70% of the prevalent patients diagnosed within 5 years
prior to the prevalence date were likely to require care for cancer recurrence,
while 13% of the prevalent cases required care for distant metastases.
PMID- 10665856
TI - Cancer prevalence in the elderly. ITAPREVAL Working Group.
AB - AIMS AND BACKGROUND: To describe the cancer prevalence in elderly Italian people
and analyze the differences, if any, with the prevalence among younger subjects.
METHODS & STUDY DESIGN: The cancer prevalence among elderly patients (65 years
and over), the three age classes encompassing elderly age (65-74 years, 75-84
years, 85 years and over) and younger patients (0-64 years) was computed using
the PREVAL method on the basis of the incident cases over the period 1976-1992
followed up to 31 December 1992 (prevalence reference date). Data were collected
by 11 Italian cancer registries. RESULTS: The observed prevalence figures for all
cancers (except skin epitheliomas), both sexes combined and considering the whole
elderly group, were 1,090 and 3,601 cases per 100,000 one and five years since
diagnosis, respectively; the prevalence increased up to the 75-84 age group and
showed a slight decrease after age 85. With regard to specific cancer sites, in
men bladder and prostate had the highest prevalence 5 years from diagnosis (more
than 800 cases per 100,000), followed by colon and lung (about 500 cases per
100,000) stomach and rectum (about 300 cases per 100,000); in women breast cancer
ranked first (more than 1,000 cases per 100,000), followed by colon (about 350
cases per 100,000), corpus uteri, stomach and rectum cancers (between 150 and 200
cases per 100,000). For all malignancies and the two sexes combined the
prevalence figures were about six times higher in the older than in the younger
age group. CONCLUSIONS: These figures confirm the important role of aging in
determining the increase in cancer prevalence. The resulting prevalence figures
clearly indicate the cancer burden placed on health care services; moreover, the
figures will probably increase in the next decades due to a possible improvement
in survival and to the dramatic aging of the population, assuming a stable trend
for incidence rates. This picture will represent a major challenge for
politicians and those dealing with health care planning and social policies in
general, especially in the light of the reduction of the available financial
resources and the specific features of medical and social needs in the elderly.
PMID- 10665857
TI - Cancer prevalence in Italian regions with local cancer registries.
AB - OBJECTIVE: To provide estimates and projections of cancer incidence and
prevalence for those Italian regions whose population is partially covered by a
cancer registry (CR) and to determine to what extent local CRs can be considered
representative of the region, thus improving the potential of the information
provided by CRs. METHODS: A statistical method, MIAMOD (mortality-incidence
analysis model), was used to estimate regional cancer incidence and prevalence
from regional cancer mortality data and patient survival data recorded by the
cancer registries. Estimates of the cancer incidence and prevalence in the
various regions have thus been obtained for a number of major cancer sitas. A
first and important step in validating the regional estimates has been the
comparison of the MIAMOD estimates in the areas covered by the cancer registries
with empirical incidence and prevalence observed by CRs, in order to assess the
consistency in data, methods and assumptions. Empirical prevalence has been
calculated by counting patients with a diagnosis of cancer who were alive on the
reference date by PREVAL method. A correction factor has been applied to include
patients diagnosed before the period of activity of the registry. RESULTS:
General consistency was found between empirical and estimated (by MIAMOD)
incidence and prevalence in the registry areas, which is indicative of the
quality and the completeness of all data involved as well as the appropriateness
of model choices. The prevalence of all cancers combined for Italian regions with
CRs was estimated and projected to the year 2000 as ranging between 1,240 per
100,000 in Sicilia and 2,781 in Emilia-Romagna for men, while for women these
figures were 1,765 in Sicilia and 4,019 in Liguria. Comparison of cancer
prevalence in CR areas with regional estimates shows quite good consistency for
Piemonte, Liguria and Lombardia, which means that the local CRs (of Torino,
Genova and Varese, respectively) are representative of their respective regions.
Prevalence in Emilia-Romagna appears to be rather well represented by only one,
the Parma CR, of the three local CRs. The southern Italian registries of Latina
and Ragusa recorded a lower cancer prevalence than was actually estimated in
their respective regions. DISCUSSION: Cancer registries with a longer period of
activity showed better agreement between empirical and estimated figures due to
the more precise information provided, particularly regarding survival and
incidence trends. In conclusion, this work shows the potential of the cancer
registries not only to represent their population with respect to cancer
morbidity but also as an invaluable tool to extrapolate this information to the
larger areas they represent.
PMID- 10665858
TI - The prevalence of cancer: a review of the available data.
AB - AIMS AND BACKGROUND: Cancer prevalence in a population, defined as the proportion
- or the number - of people who were diagnosed with a cancer during their lives
and are still alive at a given date, is a crucial indicator for heath care
planning and resource allocation. Long-term population-based cancer registries
(CR) are the appropriate tools to produce prevalence figures, which, however, are
scarcely available. This paper contains a review up to 1999 of the published data
world-wide (reports and articles) on cancer prevalence: including measured and
estimated figures. MATERIALS AND METHODS: Data on cancer prevalence from CRs are
available for the Nordic countries, Connecticut, and Italy. In addition,
electronic data are available for the European Union (EU). Data for the Nordic
countries were first published in the mid-seventies, reporting the prevalence for
1970. The first data from Connecticut were available 10 years later. Estimates
for all EU countries were published by the International Agency for Research on
Cancer (IARC) in 1997. In Italy, observed and estimated data on the prevalence of
respiratory and digestive tract cancer and breast cancer have been published
during the nineties, followed by a systematic analysis for all cancers in 1999.
By using information obtained from CRs, cancer prevalence data were calculated
directly (observed prevalence) by means of incidence and follow-up information on
individual cancer patients, or indirectly (estimated prevalence) by means of
mathematical models, which generally use epidemiological information at the
aggregate level. RESULTS: Cancer prevalence for all cancers combined (proportions
per 100,000 inhabitants) showed values of less than 700 in males and less than
800 in females in 1970 (Finland) to over 2,300 in males and over 3,000 in females
in 1992 (Italian registries). With few exceptions, in each country and period
considered the cancer sites contributing most to cancer prevalence are lung,
colon-rectum, prostate and bladder in males, colon-rectum, breast, uterus (both
cervix and corpus) and ovary in females. At present, comparison of measurements
from different areas is difficult because there exists no standardized mode of
presentation. CONCLUSIONS: In spite of their being potentially useful for health
care planning, prevalence data have been produced inconsistently and late by
cancer registries, at least in comparison with the systematic availability of
incidence and survival statistics. The available data can be compared only to a
limited extent due to differences in completeness, in the choice of indicators,
in the standard populations, and in the frequency of publication. It would be
desirable that in the future data will be produced systematically, with a higher
level of standardization compared to the past, and, most importantly, on the same
geographic and administrative scale as health-care decision-making.
PMID- 10665859
TI - Cancer prevalence. What for?
PMID- 10665860
TI - The role of cancer registration for programming health services.
AB - The Italian National Health Plan 1998-2000 indicates quantitative and qualitative
goals in the fight against cancer. This approach stresses the need of reliable
and updated descriptive data to evaluate, at a population level, the burden of
neoplastic disease, the results of primary and secondary preventive actions, and
the efforts towards a more equal distribution of diagnostic and therapeutic
services. The aims of this paper is to evaluate the use of descriptive data to
quantify the burden of neoplastic disease, using the data provided by the network
of Italian cancer registries (the most reliable source of information on
neoplastic disease in Italy). Crude rates are the most adequate for describing
the "burden" of cancer patients who are expected in a certain period and will
need specific diagnostic or therapeutic activities. Incidence, prevalence and
mortality rates provide information on different phenomena (i.e., patients
requiring diagnostic and therapeutic activities related with the first definition
and treatment of the disease; patients requiring periodic follow-up or treatment
of disease relapse; need palliative care). The use of these measures combined is
highly informative in relation with the different objectives of health planners
(i.e., patients requiring diagnostic and therapeutic activities related with the
first definition and treatment of the disease; patients requiring periodic follow
up or treatment of disease relapse; need palliative care).
PMID- 10665861
TI - MRA in patients with cerebrovascular disease. Considerations of clinical
effectiveness.
AB - OBJECTIVE: To establish in which clinical contexts cerebral MR angiography (MRA)
is routinely carried out in a neurological university department and to describe
its clinical impact. MATERIAL AND METHODS: Medical records, reports of findings
and documentation of imaging examinations carried out in all 69 patients referred
to the Department of Radiology from the Department of Neurology between 1995 and
1998 for cerebral MRA were evaluated. The clinical impact of all imaging findings
was assessed on the basis of the medical records. RESULTS: Circulatory
disturbances in the vertebrobasilar arteries (n = 34) were the most frequent
indication for investigation. MRA followed CT or duplex sonography in 66 of the
69 patients with a mean delay of 8 days. MRA was considered diagnostically
inferior to conventional MR in 11 cases, comparable in 30 and superior in 25.
Comparing MRA and duplex sonography, the corresponding figures were 12, 29 and
23. In retrospect, 56 MRAs were judged unnecessary. CONCLUSION: Controlled
clinical studies on optimal use of MRA are needed to avoid wasting resources and
to exploit the method's full diagnostic potential in appropriate cases.
PMID- 10665862
TI - Evaluation of dural sinus invasion and extension of extra-axial intracranial
tumors. The advantages of a high-resolution postcontrast 3-D gradient-echo
technique.
AB - OBJECTIVE: To assess the usefulness of a postcontrast 3-D Fourier transform
(3DFT) gradient-echo (GRE) technique in dural sinus invasion and extension of
extraaxial intracranial tumors in comparison with a conventional spin-echo (SE)
technique. MATERIAL AND METHODS: Fourteen consecutive patients with 15 extra
axial tumors in contiguity with the dural sinus, including 14 meningiomas and 1
adenoid cystic carcinoma, underwent postcontrast T1-weighted SE and GRE MR
studies. Detectability of dural sinus invasion and extension was evaluated using
two sequences by two neuroradiologists in a blinded manner and compared with
surgical results. Quantitative analysis was also performed to calculate the
contrast-to-noise ratio (CNR) between lesion and dural sinus on SE and GRE
images. The data were analyzed statistically using a matched paired t-test.
RESULTS: In the qualitative evaluation, the detectability of dural sinus invasion
in 3DFT-GRE images was superior to that using SE images. The mean CNR for all
lesions was 3.86 on SE images and 5.63 on 3DFT-GRE images (p = 0.03). CONCLUSION:
For evaluation of dural sinus invasion and the extension of extra-axial tumors,
postcontrast 3DFT-GRE MR images were superior to conventional SE images.
PMID- 10665864
TI - Does diving damage the brain? MR control study of divers' central nervous system.
AB - PURPOSE: To evaluate the prevalence of cerebral white matter changes on MR
imaging in healthy elderly compressed air divers with a long diving history in
comparison with control subjects who have never dived. MATERIAL AND METHODS: The
investigation employed 59 experienced elderly divers and 48 control subjects
matched for age, body mass index, alcohol and smoking history. MR studies
included a fluid attenuated inversion recovery sequence and T1- and T2-weighted
pre- and postcontrast images in axial orientation of the whole brain to localize
white matter changes. RESULTS: MR images did not show any morphologic
abnormalities in the brains of divers. Both groups - divers and controls - did
not differ significantly with respect to white matter changes of the brain.
CONCLUSION: No increased prevalence of cerebral white matter changes in
compressed air divers compared with a healthy worker sample of similar age were
found. Thus, extensive compressed air diving may not necessarily be related to
radiological changes on MR.
PMID- 10665863
TI - CT of the brain in tuberculous meningitis. A review of 289 patients.
AB - PURPOSE: In this retrospective study, CT findings of 289 patients with
tuberculous meningitis (TBM) are presented and diagnostic criteria are discussed.
MATERIAL AND METHODS: The medical records of patients who were diagnosed as
having central nervous system tuberculosis were investigated. Cranial CT
investigations of 289 patients with TBM were reviewed. Of these 289 patients, 214
were children and 75 adults; 157 patients were male and 132 were female. CT
images were obtained with and without i.v. contrast administration. RESULTS: CT
findings were normal in 35 patients and abnormal in 254. The abnormalities were
hydrocephalus (172 children, 32 adults), parenchymal enhancement (56 children, 6
adults), contrast enhancement of basal cisterns (32 children, 17 adults),
cerebral infarct and focal or diffuse brain edema (29 children, 10 adults), and
tuberculoma (9 children, 5 adults). CONCLUSION: CT is pathologic in the great
majority of patients with TBM and is helpful in assessing the complications
associated with the disease.
PMID- 10665865
TI - Abnormalities on brain MR images during the course of familial haemophagocytic
lymphohistocytosis in a child. A case report.
AB - PURPOSE: To describe and report the neuroradiological findings and clinical
features in a patient with familial haemophagocytic lymphohistocytosis (FHL), a
rare hereditary immune dysregulation in early childhood characterised by
multisystem involvement, including in approximately 30% of cases also the central
nervous system (CNS). MATERIAL AND METHODS: Serial brain MR examinations were
carried out in a 4.5-year-old boy with FHL, finally complicated with Epstein-Barr
virus (EBV)-driven posttransplantation lymphoma. RESULTS: Multiple brain MR
examinations before and after contrast enhancement showed discrete perivascular
non-enhancing areas of high signal intensity on T2 images, and later also an
enhancing lesion in the right caudate nucleus. CONCLUSION: FHL should be included
in the differential diagnosis of patchy white matter abnormalities in young
patients. EBV-driven post-transplantation lymphoma, which may present as
meningial and/or parenchymal CNS infiltration, is a differential diagnostic
problem.
PMID- 10665866
TI - MR appearance of paraganglioma of the cauda equina. Case reports.
AB - PURPOSE: To investigate the value of MR imaging for preoperative diagnosis of
paraganglioma of the cauda equina. MATERIAL AND METHODS: A retrospective review
of 2 cases of paraganglioma of the cauda equina examined with MR imaging was
undertaken. Features assessed included the homogeneity of the lesions, presence
or absence of serpiginous flow void and thin hypointense margins. RESULTS: In
case 1, the tumor was hyperintense on the postcontrast examination and
serpiginous flow void suggested vessels in the upper pole of the tumor. In case
2, the tumor was encapsulated by a thin hypointense margin on both T1- and T2
weighted images, which suggested hemosiderin. CONCLUSION: The MR appearance may
be of great value in the preoperative diagnosis of paraganglioma of the cauda
equina.
PMID- 10665867
TI - Dynamic MR imaging of mandibular osteoradionecrosis.
AB - PURPOSE: Osteoradionecrotic bone has been characterised as hypovascular and
metabolically inactive tissue with impaired perfusion. The present study was
conducted to determine if dynamic contrast-enhanced MR imaging could provide
additional information about the vascularity of radionecrotic mandibular bone.
MATERIAL AND METHODS: Dynamic contrast-enhanced MR imaging was performed on 10
patients with mandibular osteoradionecrosis (ORN), and on 6 patients, irradiated
for oropharyngeal tumours, without symptoms or signs of ORN. Nine patients in the
ORN group received a series of 20 hyperbaric oxygen (HBO) treatments, after which
the dynamic MR investigation was repeated. RESULTS AND CONCLUSION: Radiation per
se did not lead to increased contrast enhancement, whereas all patients with ORN
showed marked contrast enhancement of the osteoradionecrotic bone marrow. After
HBO treatment, pathological contrast enhancement of the abnormal bone marrow
could still be seen, but the rate of enhancement was less than before in 7 of 9
patients. Two patients had an increase in the enhancement rate. The findings
suggest the existence of an increased and patent microvasculature.
PMID- 10665868
TI - Early glottic squamous cell carcinoma. Predictive value of MR imaging for the
rate of 5-year local control with radiation therapy.
AB - PURPOSE: To evaluate MR findings in early (T1 and T2 stages) glottic carcinomas
and the predictive value of MR imaging for the rate of 5-year local control with
radiation therapy. MATERIAL AND METHODS: Eighty-three patients with early glottic
carcinomas were prospectively examined with MR at 1.5 T. MR investigation
included unenhanced T1-weighted, T2-weighted, dynamic and contrast-enhanced T1
weighted images. Three patients with presumed advanced diseases on MR were
initially treated with total laryngectomy and were excluded from the study. The
remaining 80 patients were treated with radiation therapy with curative intent.
Tumor detectability, size and relationship to the thyroid cartilage were
determined on MR images. The MR findings were then correlated with the rate of
local control. RESULTS: Forty-eight of 80 lesions (60%) were detected on MR
imaging. All detected lesions but 1 demonstrated increased signal on T2-weighted
images. The lesions were best delineated on dynamic images (statistically
significant). The 5-year local control rate with radiation therapy was 72%.
Univariate analysis revealed clinical T stage, MR detectability, tumor size and
relationship to the thyroid cartilage as significant predictors. Multivariate
analysis revealed that the relationship to the thyroid cartilage was an
independent factor. CONCLUSION: MR provides prognostic information about the
results of definitive radiation therapy. To evaluate the tumor extension in
lesions detected on precontrast MR images, contrast-enhanced dynamic images
should be obtained.
PMID- 10665869
TI - Doppler ultrasonography in predicting relapse of hyperthyroidism in Graves'
disease.
AB - PURPOSE: To determine whether Doppler ultrasonography could be useful in the
prediction of relapse of hyperthyroidism in patients with Graves' disease.
MATERIAL AND METHODS: Forty patients with Graves' disease confirmed by laboratory
tests were examined for a number of blood flow parameters in the inferior thyroid
artery before and after they were subjected to proper antithyroid drug treatment.
Data were retrospectively reviewed and compared with findings for a control group
of 16 age-matched subjects. RESULTS: Significantly increased blood flow
parameters were observed both in patients with active hyperthyroidism before
treatment and in euthyroid patients who presented a relapse shortly after
withdrawal of proper antithyroid drug treatment versus normal controls.
Conversely, no significant differences were observed between patients who
remained in stable remission and normal controls. CONCLUSION: Our results support
the concept that Doppler ultrasonography evaluation of patients with Graves'
disease may contribute to the detection of a relapsing course of hyperthyroidism.
PMID- 10665870
TI - CT findings in tuberculous otomastoiditis. A case report.
AB - PURPOSE: Otomastoiditis is a rare but important manifestation of tuberculosis and
is well recognizable when information on its clinical course is considered in
connection with the radiographic changes. MATERIAL AND METHOD: A patient with a
clinical history of chronic otorrhea, resistant to conventional therapy but
without dramatic symptoms, was referred for CT examination. RESULTS: CT revealed
widespread soft tissue densities in the tympanic cavity and in the mastoid
process, with bone erosions in the latter. Surgery and bacteriology confirmed the
diagnosis of Mycobacterium tuberculosis infection. CONCLUSION: CT evidence of
widespread bone destruction without clinical signs of aggressive infection should
suggest the diagnosis of a mycobacterial process. Early treatment is essential in
order to avoid propagation of the disease and lasting loss of function.
PMID- 10665871
TI - Effect on sensitivity and specificity of mammography screening with or without
comparison of old mammograms.
AB - PURPOSE: To evaluate the effect of old mammograms on the specificity and
sensitivity of radiologists in mammography screening. MATERIAL AND METHODS: One
hundred and fifty sets of screening mammograms were examined by 3 experienced
screeners twice: once without and once in comparison with older mammograms. The
films came from a population-based screening done during the first half of 1994
and comprised all 35 cancers detected during screening in 1994, 12/24 interval
cancers, 14/34 cancers detected in the following screening and 89 normal
mammograms. RESULTS: Without old mammograms, the screeners detected an average of
40.3 cancers (range 37-42), with a specificity of 87% (85-88%). With old
mammograms, the screeners detected 37.7 cancers (range 34-42) with a specificity
of 96% (94-99%). The change in detection rate was not significant. However, the
increase in specificity was significant for each screener (p = 0.0002-0.03).
CONCLUSION: Mammography screening with old mammograms available for comparison
decreased the false-positive recall rate. The effect on sensitivity, however, was
unclear.
PMID- 10665872
TI - Pre-operative simultaneous stereotactic core biopsy and fine-needle aspiration
biopsy in the diagnosis of invasive lobular breast carcinoma.
AB - PURPOSE: To determine the diagnostic value of stereotactic core needle biopsy
(SCNB) in comparison to stereotactic fine-needle aspiration biopsy (SFNAB) in
patients with invasive lobular carcinoma (ILC). MATERIAL AND METHODS: Twenty-two
patients with clinical or mammographic findings suspicious of malignancy
underwent surgery where postoperative histopathology showed ILC. Pre-operative
attempts of diagnosis were made using SFNAB and SCNB. SFNAB was done with a
spinal needle 0.7- or 0.9-mm and SCNB was simultaneously performed with an
automated 2.1-mm biopsy gun in all patients. RESULTS: SFNAB was diagnostic of
carcinoma in 9 women, showed "probable carcinoma" in 5 and "atypia" in 3. In the
remaining 5 women, SFNAB showed no atypia. SCNB diagnosed ILC in 20 patients and
showed ILC as well as invasive ductal carcinoma (IDC) in 1. Ductal carcinoma in
situ was suggested in the remaining patient. CONCLUSION: SCNB was superior to
SFNAB in diagnosing ILC and did not miss any carcinoma, whereas SFNAB was non
diagnostic in 8 cases. SCNB is thus recommended in patients with suspicion of ILC
of the breast.
PMID- 10665873
TI - Primary tuberculosis of the breast. A case report.
AB - The mammographic and US features of a case of primary tuberculosis of the breast
are presented. The differential diagnosis with other benign or malignant
conditions of the breast can be difficult with imaging methods due to the
variable pattern of presentation of such an inflammatory lesion.
PMID- 10665874
TI - High-resolution imaging of coronary calcifications by intense low-energy
fluoroscopic X-ray obtained from synchrotron radiation.
AB - PURPOSE: To obtain an intense monochromatic low-energy X-ray from synchrotron
radiation (SR) and apply it to detect coronary calcifications. METHODS AND
RESULTS: The SR beam was reflected with a silicon crystal to be expanded (150 mm
in height and 80 mm in width) and to be monochromatized at an energy level of 37
keV. The X-ray was intermittently irradiated to obtain dynamic imaging of 30
images/s. Images were recorded by a digital fluorography system. The low-energy X
ray from SR sharply visualized calcification of coronary arteries, while
conventional X-ray could not visualize coronary calcification. CONCLUSION: The
intense monochromatic low-energy X-ray from SR is sensitive, has high-resolution
for imaging coronary calcification and may serve as a screening method for
coronary artery disease.
PMID- 10665875
TI - A double coaxial delivery system for deployment of a two-stage stent-graft. An
experimental feasibility study.
AB - PURPOSE: To design and test a delivery system for successive, rapid two-stage
deployment of an aortic stent graft. MATERIAL AND METHODS: An aortic stent graft
was made that consisted of two separate parts. A delivery system composed of two
independent coaxial mechanisms was fabricated and used to deploy the stages of
the graft in dogs' aortas. RESULTS: Delivery was successful in all four dogs, and
required less than 2 min in each animal. CONCLUSION: The double coaxial delivery
system enabled quick endovascular assembly of a two-stage aortic stent-graft.
PMID- 10665876
TI - Infrapopliteal percutaneous transluminal angioplasty for limb salvage.
AB - PURPOSE: To evaluate long-term results of infrapopliteal percutaneous
transluminal angioplasty (PTA) for limb salvage. MATERIAL AND METHODS: A
retrospective study of 71 consecutive infrapopliteal PTAs in 49 patients with
rest pain (n = 20) or ulceration (n = 29) was conducted. In 18 patients, surgical
minor amputation or debridment was also performed. RESULTS: Technical success was
achieved in 45 patients. Four failures necessitated 2 amputations. One patient
died in the postoperative course. Global morbidity rate was 16%, including minor
complications in 5 patients and major vascular complications in 3 patients. After
technical success during the follow-up (median duration 21 months), restenoses
occurred in 4 patients, of whom 3 had a successful re-PTA (clinical success rate
72%). Survival, primary patency, secondary patency and limb salvage rates were,
respectively, 75%, 81%, 88% and 87% after 3 years. The only positive predictive
factor for primary patency was the presence of diabetes mellitus. CONCLUSION:
Infrapopliteal PTA is a safe and effective procedure, allowing good patency and
limb salvage rates with low mortality and morbidity.
PMID- 10665877
TI - High-resolution MR imaging of the carpal tunnel and the wrist. Application of a 5
cm surface coil.
AB - PURPOSE: To make a comparative analysis of transversal tomograms obtained by high
resolution MR imaging with frozen cross-sections of an anatomical forearm
specimen. Twenty-two healthy volunteers were also examined using the same coil
system to test for a range of possible clinical applications and for the
depiction of morphological and morphometrical values of normal anatomy in vivo.
MATERIAL AND METHODS: MR images of the carpal tunnel of 22 healthy volunteers
were obtained with a 1.5-T whole-body system with a 5-cm surface coil.
Measurements were recorded with a field-of-view between 50x50 mm2 and 60x60 mm2
in a 256x256 pixel matrix for the T1 sequence. A slice thickness of 2 mm was
used. The images were acquired using a T1-weighted SE sequence (TR/TE 500/38 ms)
and a T2-weighted SE sequence (TR/TE 2000/70 ms). Additionally, a formalin-fixed
anatomical forearm specimen was imaged for anatomic correlation. The imaged
transversal cross-section levels in the specimen were subsequently freeze
sectioned. The anatomical structures of the MR findings were identified and
compared with the macroscopical sections of the specimen. RESULTS: Based on the
good depiction of details at this coil system with a pixel size in T1 of
0.195x0.195 mm, high-resolution MR imaging enabled identification of the interior
structures of the carpal tunnel, as well as delineation of connective tissue. The
clinical value of high-resolution MR includes the diagnosis of carpal tunnel
syndrome and inflammatory disorders of the wrist. CONCLUSION: Our results support
the feasibility of high-resolution MR imaging of the carpal tunnel and the wrist
using small surface coils.
PMID- 10665878
TI - High-resolution MR imaging of the knee at 3 T.
AB - PURPOSE: To examine the practical feasibility of using a 3.0-T MR unit to obtain
high-quality, high-resolution images of the knee joint. MATERIAL AND METHODS: One
human cadaveric and 5 porcine knees were imaged with the 3.0-T unit. Sets of T1
weighted spin echo images were obtained with in-plane resolution of 0.195x0.39 mm
and an acquisition time of approximately 5 min. Two porcine knees were also
imaged with the 1.0-T unit with an identical imaging protocol and the signal-to
noise (S/N) ratios were measured on images at 3 T and 1 T. RESULTS: The 3-T MR
system provided detailed delineation of the knees. Deep layers of the medial
collateral ligament and associated fine fibers beneath the medial and lateral
collateral ligament were demarcated. We observed precise demonstration of the
tibial attachment of the anterior cruciate ligament, irregularity of the meniscal
free edge, and conjoint tendon formation together with the lateral collateral
ligament and the biceps femoris tendon. Compared to the 1-T unit, the S/N ratio
with the 3-T unit was increased by a factor of 1.39 to 1.72. CONCLUSION: Due to
the potential advantage of obtaining detailed images, the 3-T MR system suggests
a practical utility for fine demonstration of the knee morphology.
PMID- 10665879
TI - MR findings of desmoplastic fibroma of the spine. A case report.
AB - We report on the MR imaging findings in a case of spinal desmoplastic fibroma
(DF). DF of the bone is a rare, locally aggressive tumor. It is commonly located
in long bones, pelvis or mandible. DF involving the spine is extremely rare and
difficult to distinguish from other bony lesions such as giant cell tumor,
chordoma and fibrous dysplasia of the spine. This case of DF of the spine showed
MR findings similar to those of DF arising in the metaphysis of a long bone.
PMID- 10665880
TI - Glycogen content in rat liver. Importance for CT and MR imaging.
AB - PURPOSE: CT and MR imaging are appropriate modalities for imaging of the liver.
Contrast media are used to obtain a greater difference in attenuation and signal
intensity, respectively, between normal liver tissue and focal lesions. However,
no studies have attempted to determine whether physiological nutritional status
of the liver during fasting is of importance for the native signal of normal
liver tissue. MATERIAL AND METHODS: Using normal and fasting rats, we performed
hepatic CT and MR imaging and glycogen analyses from excised tissue. RESULTS: A
significantly higher liver attenuation in normal rats compared to fasting rats
was found in CT. In MR images, there was a small but significantly lower liver
signal-to-noise ratio in normal rats compared to fasting rats in T1-weighted and
proton density-weighted images. Glycogen analyses showed depleted glycogen
deposits in fasting rats and a mean glycogen content of 50.1 mg glucose
equivalent/g liver tissue in normal rats. CONCLUSION: In CT, a normal nutritional
status increases the native attenuation in normal liver tissue. The changes in
attenuation in normal liver tissue correlate well with the additional attenuation
of glycogen storage in the hepatocyte. The results indicate that the nutritional
status is of less importance in MR imaging.
PMID- 10665881
TI - Impact of intraoperative ultrasonography on surgical treatment of liver tumours.
AB - PURPOSE: The aim of this study was to evaluate the impact of intraoperative
ultrasonography (IOUS) on surgical decision-making in patients with liver
tumours. MATERIAL AND METHODS: IOUS of the liver was performed in 116 patients
undergoing surgery for liver tumours. The patients were evaluated preoperatively
by ultrasonography, CT and in some cases, by ERCP and scintigraphy. IOUS findings
were compared with the results of preoperative imaging and surgical findings.
RESULTS: The surgical procedures were altered in 50 cases (43%), extended in 19
cases (16%) and reduced in 8 cases (7%). Twenty-three patients (20%) were found
inoperable. Intraoperative evaluation caused surgical modification by IOUS in 13
patients (11%), by surgical findings in 14 patients (12%) and by a combination of
both in 23 patients (20%). CONCLUSION: IOUS is a precise diagnostic method for
staging the operability of liver tumours. Unnecessary surgical procedures can be
avoided. In total, IOUS altered the preoperative plan in one-third of our
patients and is therefore recommended as a routine procedure in connection with
major liver surgery.
PMID- 10665882
TI - Structure and content of 400 CT reports in four teaching hospitals using a new,
Windows-based software tool.
AB - PURPOSE: To test a new software tool developed for analysis of radiology reports
and to compare CT reports from four different teaching hospitals. MATERIAL AND
METHODS: Four hundred CT reports were randomly collected from four Finnish
university hospitals. A Windows 3.1-based software tool was developed to make a
comparative analysis of the information content of CT reports. The structure of
the reports was partly analyzed manually. RESULTS: The new software tool greatly
facilitated semiquantitative analysis of the information content of residents'
and radiologists' reports. There were some local differences in the length and
structure of the reports, the choice of vocabulary and the number of differential
diagnoses given, and large differences in the use of an "impression" section.
Thorough description of focal lesions was included in less than 50% of the
reports from each of the four institutions. CONCLUSION: The variation in well
structured CT reports indicates considerable geographic differences in radiology
reporting, which may reflect the long-term influences of a few teachers. Rational
application of the communication standards should improve the quality of written
radiology reports. Such standards should be emphasized, particularly in teaching
hospitals.
PMID- 10665883
TI - Analysis of the availability and completeness of previous radiological
examinations related to plain films.
AB - PURPOSE: To evaluate the availability and completeness of previous radiological
examinations. MATERIAL AND METHODS: Seven different types of examinations were
analysed separately: 1) chest examinations, 2) bedside chest examinations, 3)
skeletal examinations, 4) angiographic examinations, 5) mammographic
examinations, 6) CT examinations, and 7) MR examinations. A retrospective part of
the study covered the calendar year 1997, while a prospective part referred to
1998. The sample size in each modality and each part of the study was 100
observations, resulting in a total number of 1,400 examinations. RESULTS: The
average availability and completeness of radiographs in the retrospective
analysis was 96.9% in 1997. The average availability and completeness of
radiographs in the prospective analysis was 85.5% for the year 1998. This applied
to necessary previous examinations of the same or different modality irrespective
whether the examination was conducted internally or externally. CONCLUSION: The
real loss rate of radiographs derived from the retrospective investigation was
3.1%. The prospective part of the study showed that 14.5% of the required
previous internal and external examinations of the same or different modality
were not available completely and in time to the examining radiologist.
PMID- 10665884
TI - The autopsy and the living. Autopsy Committee of the College of American
Pathologists.
PMID- 10665885
TI - Melatonin therapy: from benzodiazepine-dependent insomnia to authenticity and
autonomy.
PMID- 10665887
TI - Billions for defense: the pervasive nature of defensive medicine.
PMID- 10665886
TI - The lost art of auscultation.
PMID- 10665888
TI - An update on perioperative management of diabetes.
AB - Surgery in the patient with diabetes mellitus is relatively common, as the
numbers of persons with diabetes is increasing and diabetes predisposes to
medical conditions that require surgical intervention. An estimated 25% of
diabetic patients will require surgery, and advances in perioperative care of
these patients allow them to safely undergo the most complicated surgical
procedures. We will review issues of preoperative, intraoperative, and
postoperative care of diabetic patients.
PMID- 10665889
TI - Cigar smoking and death from coronary heart disease in a prospective study of US
men.
AB - CONTEXT: The prevalence of cigar smoking has increased rapidly in the United
States since 1993. Although cigarette smoking is known to be an important cause
of coronary heart disease (CHD) mortality, the relationship between cigar smoking
and CHD mortality is unclear. OBJECTIVE: To determine whether cigar smoking
increases risk of CHD mortality. DESIGN: Prospective cohort study with follow-up
for mortality from 1982 through 1991. SETTING: United States. PARTICIPANTS: A
total of 121 278 men, aged 30 years and older, in the American Cancer Society's
nationwide Cancer Prevention Study II cohort who completed a baseline
questionnaire on smoking history and other risk factors in 1982, had never smoked
cigarettes or pipes, and had no diagnosed heart disease or diabetes at baseline.
MAIN OUTCOME MEASURE: Death from CHD recorded as the underlying cause of death on
the death certificate. RESULTS: There were 2508 deaths from CHD from 1982 through
1991. The association between cigar smoking and death from CHD was stronger among
younger men and current rather than former smokers, as is observed with cigarette
smoking. No increased risk was observed among current cigar smokers aged 75 years
or older, or for former cigar smokers of any age. For men younger than 75 years
who were current cigar smokers at baseline, the adjusted rate ratio for CHD
mortality was 1.30 (95% confidence interval, 1.05-1.62). CONCLUSIONS: These
results suggest that smoking cigars increases risk of early death from CHD. Any
adverse effect of cigars on CHD is of particular importance given the rapidly
rising prevalence of cigar smoking in the United States.
PMID- 10665890
TI - Asthma self-management: do patient education programs always have an impact?
AB - BACKGROUND: During the past 15 years, programs to improve self-management
practices in adults with asthma have reported improvement in functional status
and reduction of inappropriate use of health care services. However, these
programs usually represent an ideal approach, applying multiple patient education
methods. Consequently, when these programs are found to be efficacious, it is
important to replicate the programs as well as to evaluate less complex methods
that may be more appropriate for nonacademic health care settings. METHODS: We
compared the following 3 standardized self-management treatments in a randomized,
controlled trial: (1) a replication of the self-management program developed at a
university medical center that was previously shown to be efficacious; (2) a
modified version of this program including only the core elements; and (3) a
usual-care program. Outcome measures included medication and inhaler regimen
adherence, asthma symptoms, respiratory illness, functional status, and use of
health care resources. RESULTS: All 3 groups improved on measures of respiratory
illnesses, use of health care services, and functional status. Patients in both
education groups did no better than the usual-care group. CONCLUSIONS: The
results are inconsistent with the results of the first asthma self-management
study at this institution and with those of efficacy studies of similar programs.
Two factors, selection of the patient population and historical changes in asthma
treatment, most likely contributed to the lack of impact of the self-management
programs. As a result of the improved standards for usual care due to both
factors, the opportunity to effect patient outcomes was substantially reduced.
PMID- 10665891
TI - Persistent stress as a predictor of genital herpes recurrence.
AB - BACKGROUND: Results of several studies suggest that psychological stress and
negative mood can trigger genital herpes recurrences, but results are
inconsistent. OBJECTIVE: To determine whether short-term or persistent
psychological stress or specific negative moods are predictive of genital herpes
recurrences in women. METHODS: A prospective cohort study followed up
participants for 6 months using weekly assessments of stress and mood, monthly
assessments of life change events, and diary reports of genital herpes
recurrences confirmed by medical examination when feasible. The community sample
consisted of 58 women, aged 20 to 44 years, with a 1- to 10-year history of
visible genital herpes recurrence and at least 1 recurrence in the previous 6
months. RESULTS: Persistent stress predicted recurrence in the subsequent week
(odds ratio, 1.08 per unit increase in stress; 95% confidence interval, 1.01
1.15; P=.03). After adjusting for recurrence in the previous week, the more
weekly persistent stress reported, the greater the likelihood of recurrence the
following week. Also, an increased recurrence rate occurred after the month
during which participants experienced their highest levels of anxiety (P =.03).
There were no significant associations between recurrence and short-term stress,
life events, depressive mood, anger, or phase of menstrual cycle. CONCLUSIONS:
Persistent stressors and highest level of anxiety predicted genital herpes
recurrence, whereas transient mood states, short-term stressors, and life change
events did not. Women with herpes can be reassured that short-term stressful life
experiences and dysphoric mood states do not put them at risk for increased
outbreaks of recurrent genital herpes.
PMID- 10665892
TI - The health and economic benefits associated with pneumococcal vaccination of
elderly persons with chronic lung disease.
AB - BACKGROUND: More than 50% of the elderly population has not received pneumococcal
vaccination. Uncertainty regarding the benefits of immunization, particularly for
noninvasive disease, may contribute to the underuse of pneumococcal vaccine.
OBJECTIVE: To assess the health and economic benefits associated with
pneumococcal vaccination. METHODS: We conducted a 2-year retrospective cohort
study among all elderly members of a staff-model managed care organization who
had a baseline diagnosis of chronic lung disease. The study outcomes were
assessed over 2 years, from November 15, 1993, through November 14, 1995, and
included hospitalizations for pneumonia and influenza, death, and hospitalization
costs. Using administrative data, we compared these outcomes for vaccinated and
unvaccinated subjects using multivariate models to control for subjects' baseline
demographic and health characteristics. The additive benefits of combined
influenza and pneumococcal vaccination were also assessed for the 2 influenza
seasons included in the study. RESULTS: There were 1898 subjects. Pneumococcal
vaccination was associated with significantly lower risks for pneumonia
hospitalizations (adjusted risk ratio [RR], 0.57; 95% confidence interval [CI],
0.38-0.84; P=.005) and for death (adjusted RR, 0.71; 95% CI, 0.56-0.91; P =
.008). For the control outcome of all nonpneumonia hospitalizations, rates did
not differ significantly between the 2 groups (adjusted RR, 0.91; 95% CI, 0.77
1.07; P= .24). During the influenza seasons included in the study, the benefits
of pneumococcal and influenza vaccinations were additive, with an adjusted RR of
0.28 (95% CI, 0.14-0.58; P<.001) for the number of hospitalizations for pneumonia
and influenza among persons who had received both vaccinations compared with
those who had received neither and an adjusted odds ratio of 0.18 (95% CI, 0.11
0.31; P<.001) for death. Over the 2-year outcome period, pneumococcal vaccination
was also associated with direct medical care cost savings. CONCLUSIONS:
Pneumococcal vaccination of elderly persons with chronic lung disease was
associated with fewer hospitalizations for pneumonia, fewer deaths, and direct
medical care cost savings.
PMID- 10665893
TI - Early switch from intravenous to oral antibiotics and early hospital discharge: a
prospective observational study of 200 consecutive patients with community
acquired pneumonia.
AB - To determine the proportion of patients who can be treated with early switch to
oral antibiotics and early discharge, to evaluate clinical outcome and patient
satisfaction for patients treated with early switch and early discharge, and to
define the factors that interfere with early discharge for some of the patients
who underwent early switch to oral antibiotic therapy. DESIGN: Prospective study.
PARTICIPANTS: Two hundred consecutive hospitalized patients with community
acquired pneumonia. MAIN OUTCOME MEASURES: Number of days needed to switch to
oral therapy and length of hospital stay. Clinical outcome and satisfaction with
care were evaluated for those patients treated with early switch and early
discharge. RESULTS: Early switch to oral antibiotics (within the first 3 days of
hospitalization) was performed in 133 patients (67%). Clinical failure was
documented in 1 patient. Early switch and early discharge was performed in 88
patients (44%). The mean length of hospital stay for this group was 3.4 days. The
most common reason for prolonged hospitalization after the switch to oral
antibiotics was the need for diagnostic workup. More than 95% of patients were
satisfied with the care they had received. CONCLUSIONS: Using simple clinical and
laboratory criteria, a significant proportion of hospitalized patients with
community-acquired pneumonia (44%) can be treated with early switch and early
discharge. This model did not affect patient outcome, decreased the length of
hospitalization, and was associated with a high level of patient satisfaction.
PMID- 10665894
TI - Facilitation of benzodiazepine discontinuation by melatonin: a new clinical
approach.
AB - BACKGROUND: Benzodiazepines are the most frequently used drug for the treatment
of insomnia. Prolonged use of benzodiazepine therapy is not recommended. However,
many patients, particularly older patients, have difficulties discontinuing
therapy. Melatonin, a hormone that is produced at night by the pineal gland,
promotes normal sleep in humans and augments sleep induction by benzodiazepine
therapy. OBJECTIVE: To assess whether the administration of melatonin could
facilitate the discontinuation of benzodiazepine therapy in patients with
insomnia. METHODS: Thirty-four subjects receiving benzodiazepine therapy were
enrolled in the 2-period study. In period 1, patients received (double-blinded)
melatonin (2 mg in a controlled-release formulation) or a placebo nightly for 6
weeks. They were encouraged to reduce their benzodiazepine dosage 50% during week
2, 75% during weeks 3 and 4, and to discontinue benzodiazepine therapy completely
during weeks 5 and 6. In period 2, melatonin was administered (single-blinded)
for 6 weeks to all subjects and attempts to discontinue benzodiazepine therapy
were resumed. Benzodiazepine consumption and subjective sleep-quality scores were
reported daily by all patients. All subjects were then allowed to continue
melatonin therapy and follow-up reassessments were performed 6 months later.
RESULTS: By the end of period 1, 14 of 18 subjects who had received melatonin
therapy, but only 4 of 16 in the placebo group, discontinued benzodiazepine
therapy (P = .006). Sleep-quality scores were significantly higher in the
melatonin therapy group (P = .04). Six additional subjects in the placebo group
discontinued benzodiazepine therapy when given melatonin in period 2. The 6-month
follow-up assessments revealed that of the 24 patients who discontinued
benzodiazepine and received melatonin therapy, 19 maintained good sleep quality.
CONCLUSION: Controlled-release melatonin may effectively facilitate
discontinuation of benzodiazepine therapy while maintaining good sleep quality.
PMID- 10665895
TI - The association between antecedent vancomycin treatment and hospital-acquired
vancomycin-resistant enterococci: a meta-analysis.
AB - BACKGROUND: The association between vancomycin hydrochloride treatment and
vancomycin-resistant enterococci (VRE) has been investigated in numerous studies
with variable results. OBJECTIVES: To conduct a meta-analysis to estimate the
magnitude of the association between vancomycin treatment and individual risk of
VRE and to identify study characteristics that accounted for heterogeneity in
study results. METHODS: Studies were identified using MEDLINE with index terms
"Enterococcus," "Enterococcus faecalis," or "Enterococcus faecium" and
"vancomycin," "drug resistance," "drug resistance, microbial," or "drug
resistance, multiple or risk factors." Reports from conferences and reference
lists of recent reviews were used. A total of 420 published reports and 98
conference reports were reviewed; 20 studies described in 15 published reports
were included in the analysis. We recorded study period, hospital setting, case
and control definitions, length of hospital stay, method of adjustment for
differences in length of stay, and data on treatment with vancomycin. The odds
ratio (OR) of vancomycin treatment provided the measure of association analyzed.
A random-effects model was used to estimate the pooled OR. RESULTS: When results
from all 20 studies were combined, the pooled OR was 4.5 (95% confidence
interval, 3.0-6.9), but the test for heterogeneity was highly significant
(P<.001). The 5 studies that used patients with vancomycin-susceptible
enterococci as controls found a stronger association (pooled OR, 10.7; 95%
confidence interval, 4.8-23.8) than the 15 studies that used controls who had no
VRE isolated (pooled OR, 2.7; 95% confidence interval, 2.0-3.8). After
restricting the analysis to the latter studies only, no heterogeneity was evident
in the unadjusted study results. Patients with VRE had stayed in the hospital
much longer than control patients. Studies that adjusted for this difference
found only a small and nonsignificant association between vancomycin treatment
and VRE (pooled OR, 1.4; 95% confidence interval, 0.74-2.60). We also detected
publication bias, favoring report of studies that found a large measure of
association. CONCLUSIONS: The reported strong association between vancomycin
treatment and hospital-acquired VRE results from the selection of the reference
group, confounding by duration of hospitalization, and publication bias. Studies
that accounted for these factors found only a small and nonsignificant
association.
PMID- 10665896
TI - Diabetes mellitus and nontraumatic lower extremity amputation in black and white
Americans: the National Health and Nutrition Examination Survey Epidemiologic
Follow-up Study, 1971-1992.
AB - BACKGROUND: The comparative long-term risk of non-traumatic lower extremity
amputation (LEA) in black and white Americans, 2 groups with strikingly different
rates of diabetes mellitus, is not known. OBJECTIVE: To examine the 20-year
incidence of LEA in relation to race and diabetes mellitus. METHODS: The 14 407
subjects in the National Health and Nutrition Examination Survey Epidemiologic
Follow-up Study were observed prospectively between 1971 and 1992. Prevalent
diabetes mellitus was ascertained at the baseline examination, and incident
diabetes mellitus, during follow-up. Lower extremity amputation was ascertained
from hospital discharge records. Cox regression analysis was used to estimate
associations between race, diabetes mellitus, and risk of first LEA. RESULTS:
During the study period, 158 LEAs occurred among 108 subjects. While black
subjects constituted 15.2% of the cohort, they represented 27.8% of the subjects
with amputation (P = .002). The 20-year age-adjusted rate ratio of first LEAs for
black subjects-white subjects was 2.14. Regression analyses confirmed the
importance of diabetes mellitus as a key LEA risk factor. The association between
prevalent diabetes mellitus and LEA risk was substantially higher (relative risk
[RR], 7.19; 95% confidence interval [CI], 4.61-11.22) than that for incident
diabetes mellitus (RR, 3.15 [CI, 1.84-5.37]), highlighting the importance of
diabetes mellitus duration on LEA risk. While preliminary analyses adjusted for
age and diabetes indicated a significant association between race and LEA risk
(RR, 1.93 [95% CI, 1.26-2.96]), the effect of race diminished (RR, 1.49 [95% CI,
0.95-2.34]) following adjustment for education, hypertension, and smoking.
CONCLUSIONS: Although black subjects experienced higher age- and diabetes
mellitus-adjusted rates of amputation than their white counterparts, a
combination of social and environmental factors may account for the apparent
ethnic difference. More research into nonbiological factors associated with LEA
may reduce the occurrence of these procedures in both black and white
individuals.
PMID- 10665897
TI - Cardiopulmonary auscultation: duo for strings--Opus 99.
AB - In spite of increasing mechanization in medicine and reliance on "high-tech"
diagnostic tools, bedside clinical skills of the attending physician can still
identify findings that are missed by the more sophisticated devices. Using a
stethoscope, we relied on our skills in inspection, palpation, percussion,
auscultation, as well as echocardiography and phonocardiography to diagnose a
patient whose murmur was very reminiscent of the D-sharp pizzicato in the Cello
Sonata in F, Opus 99, by Johannes Brahms. Initial echocardiography was not
helpful. We suspected an anomalous chorda and confirmed this with
phonocardiography and a second echocardiography. Although advances in cardiac
imaging are extremely helpful, the use of simple clinical skills, in addition to
being fun, is not obsolete. Cardiopulmonary auscultation should receive more
emphasis in the medical school curriculum and clinical training.
PMID- 10665898
TI - Fibromyalgia, chronic fatigue syndrome, and Addison disease.
PMID- 10665899
TI - Patients with fibromyalgia must be treated fairly.
PMID- 10665900
TI - Helicobacter pylori and gastric cancer: both primary and secondary preventive
measures are required.
PMID- 10665901
TI - Neurocardiogenic syncope and cancer: a paraneoplastic association?
PMID- 10665902
TI - Is garlic an effective treatment for Helicobacter pylori infection?
PMID- 10665903
TI - Latex agglutination is a valid method for the measurement of D-dimer levels.
PMID- 10665904
TI - To E or not to E.
PMID- 10665905
TI - A futurist meets the 21st century: love at first sight.
PMID- 10665906
TI - Cardiac autonomic denervation in congestive heart failure: comparison of Chagas'
heart disease with other dilated cardiomyopathy.
AB - Congestive heart failure (CHF) is associated with activation of the cardiac
sympathetic nerves. However, impairment of the sympathetic nerve terminals in
patients with CHF has been indicated by studies showing reduction of cardiac
norepinephrine uptake and stores. This investigation studies the histochemical
evaluation of the sympathetic nerve terminals in CHF. The cardiac parasympathetic
innervation was also studied to address the question of specificity of the
presumed sympathetic denervation. Nineteen patients with CHF underwent cardiac
transplantation or partial ventriculectomy, which provided the heart tissue. In
11 of them, the dilated cardiomyopathy was associated with Chagas' disease.
Inflammatory process and fibrosis were studied histologically. The sympathetic
and parasympathetic nerve fibers were visualized through histochemical techniques
for, respectively, catecholamines and acetylcholinesterase activity. By using a
computer-assisted morphometric program, the inflammation, fibrosis, and
parasympathetic innervation were quantified. Moderate to severe fibrosing
myocarditis characterized the hearts of the chagasic patients. In
cardiomyopathies not associated with Chagas' disease, the inflammation was
discrete, if present, but the amount of fibrosis was similar to that found in
Chagas' cardiomyopathy. Reduction of both kinds of nerve terminals occurred in
the heart of all patients. The parasympathetic denervation was proven to be more
severe in chagasic cardiomyopathy. Our data on the heart innervation indicate a
progressive autonomic denervation in heart failure. In Chagas' heart disease, the
denervation seems to be more severe or rapid, probably because of the sustained
inflammatory process.
PMID- 10665907
TI - GLUT1: a newly discovered immunohistochemical marker for juvenile hemangiomas.
AB - Juvenile hemangiomas are common, benign vascular tumors of infancy. These lesions
enlarge rapidly through cellular hyperplasia during the first year of life and
then involute over several years. Distinctive histopathologic features of
hemangiomas diminish during this evolution, and differentiation from vascular
malformations becomes increasingly difficult. This distinction has important
therapeutic implications, as juvenile hemangiomas differ from malformations in
natural history and in potential for recurrence. We report here that high
endothelial immunoreactivity for the erythrocyte-type glucose transporter protein
GLUT1 is a specific feature of juvenile hemangiomas during all phases of these
lesions. In a retrospective study, we found intense endothelial GLUT1
immunoreactivity, involving more than 50% of lesional microvessels, in 97% (139
of 143) of juvenile hemangiomas from patients aged 1 month to 11 years. No
endothelial GLUT1 immunoreactivity was found in any of 66 vascular malformations
(17 arteriovenous, 33 venous, 11 lymphatic, and 5 port-wine) from patients aged 5
days to 75 years, or in any of 20 pyogenic granulomas or 7 granulation tissue
specimens. Abundant Ki-67 positivity in these latter lesions established that
GLUT1 expression does not simply reflect mitotically active endothelium. Focal
GLUT1 immunoreactivity was found in 3 of 12 angiosarcomas, but not in any of 5
hemangioendotheliomas (epithelioid or infantile kaposiform). These findings
establish GLUT1 immunoreactivity as a highly selective and diagnostically useful
marker for juvenile hemangiomas. Because high levels of endothelial GLUT1
expression in normal tissue are restricted to microvessels with blood-tissue
barrier function, these findings also have implications for the molecular and
developmental pathogenic mechanisms of juvenile hemangiomas.
PMID- 10665908
TI - Cytological recognition of invasive squamous cancer of the uterine cervix:
comparison of conventional light-microscopical screening and neural network-based
screening.
AB - Cytologic recognition of invasive or microinvasive cancer of the uterine cervix
may present substantial difficulties. In this study, we compared conventional
light-microscopical screening of 109,104 cervical smears and neural network-based
screening (NNS) of 245,527 smears, all obtained by the spatula-Cytobrush method.
Two populations of Dutch women were included in the study: those receiving smears
within the framework of the Dutch population screening program ("routine smears")
and those receiving smears for other reasons, discussed in the text ("interval
smears"). There were 71 smears, from an equal number of biopsy-confirmed invasive
squamous carcinomas, 28 of which were microinvasive. The "interval smears"
yielded a statistical valid higher prevalence of invasive cancer than "routine
smears." Except for 5 smears that contained no evidence of abnormality ("sampling
errors"), no false-negative errors occurred in the 52 NNS cases, whereas 4 such
errors occurred in the 19 conventionally screened cases. By measuring the amount
of cancerous material present in each smear (mapping), it could be documented
that NNS was effective even in smears with a small number of cancer cells,
whereas the 4 conventional false-negative screening errors occurred in smears of
this type. The study showed that cells derived from invasive cancer of the cervix
may have large bland nuclei that do not fit the images commonly associated with
squamous cancer cells. Neural network-based screening of cervical smears was more
effective than conventional screening in the diagnosis of invasive squamous
cancer of the uterine cervix.
PMID- 10665909
TI - Malignant epithelioid vascular tumors of the pleura: report of a series and
literature review.
AB - Primary malignant vascular tumors of the pleura are rare. The significance and
difficulty of distinction between pleural epithelioid hemangioendothelioma (EHE)
and angiosarcoma have not yet been addressed. A new series of pleural
angiosarcoma is reported, and the relevant literature is reviewed. Five cases
were identified from files of the authors' institutions and personal consultation
cases (J.J.B.). Twenty-six cases of primary malignant vascular tumors of the
pleura were identified in the literature. In a total of 31 cases, 22 were from
the West and 9 from Japan. Patients were 22 to 79 years old (average, 57), and
the male/female ratio was 9:1. Prior chronic pyothorax was identified only in
cases reported from Japan. History of exposure to radiation or asbestos was noted
in a few Western cases. The most common presentation was pleural thickening and
effusion. Almost all of the patients died of disease shortly after diagnosis. A
spectrum of histology ranging from characteristic high-grade epithelioid to
relatively low-grade EHE-like features was observed in our cases and can be found
in previous reports. Most cases showed variable spotty cytokeratin
immunoreactivity. Endothelial markers (factor 8, CD34, or CD31) were invariably
positive. Pleural angiosarcomas are often epithelioid and can be easily mistaken
for mesothelioma or carcinoma clinically and histologically. Awareness of this
rare tumor should prompt the use of endothelial markers when faced with a
questionable mesothelioma. When cytokeratin is negative, or focal with strong
vimentin reactivity, a vascular tumor should be suspected and confirmed with
vascular markers. Because of their invariably aggressive behavior, all
epithelioid vascular tumors of the pleura should be considered highly malignant
regardless of the presence of EHE-like histological features.
PMID- 10665910
TI - HER-2/neu gene amplification by FISH predicts poor survival in Barrett's
esophagus-associated adenocarcinoma.
AB - The HER-2/neu oncogene is localized to chromosome 17q and shares significant
homology with the epidermal growth factor receptor. HER-2/neu protein
overexpression has been associated with poor prognosis in a variety of tumors,
but its significance in Barrett's esophagus-associated adenocarcinoma (BEAd) is
unknown. Therefore, the aim of this study was to evaluate the prevalence and
prognostic value of HER-2/neu gene amplification by fluorescence in situ
hybridization (FISH) in 63 cases of BEAd. Routinely processed tissue sections
from resection specimens of 63 patients with BEAd (M/F ratio, 10:1; mean age, 63
years) were assayed for HER-2/neu gene amplification by FISH using the Ventana
unique sequence probe (Ventana Medical Systems, Inc, Tuscon, AZ). FISH results
were correlated with the pathological features of the tumors and with patient
survival. Clinical follow-up data were available for 54 patients (mean follow-up,
31 months [range, 1 to 152 months]). The HER-2/ neu gene was amplified in 12 of
63 (19%) cases. The presence of HER-2/neu gene amplification showed a trend
toward a correlation with depth of tumor invasion (P = .07), lymph node
metastasis (P = .13), and pathological stage (P = .14), but did not correlate
with any of the other pathological features, such as degree of differentiation or
tumor size. On both univariate and multivariate analysis, HER-2/neu gene
amplification was associated with shortened survival (P = .03). HER-2/neu
oncogene amplification, as determined by FISH, correlates with shortened patient
survival and independently predicts poor outcome in patients with BEAd.
PMID- 10665911
TI - Orthotopic liver transplantation for familial amyloidotic polyneuropathy: a
pathological study.
AB - Familial amyloidotic polyneuropathy (FAP), a hereditary form of systemic
amyloidosis with clinically significant neuropathy and cardiomyopathy, is caused
by a genetic defect of the transthyretin gene, which is mostly synthesized in the
liver. Orthotopic liver transplantation (OLT) is thought to eliminate the
amyloidogenic protein and currently is the only definitive treatment for this
disorder. The aim of this study was to define the distribution and extent of
amyloid deposition in tissues from these patients and evaluate the suitability of
the resected FAP livers for transplantation into non-FAP patients. Surgical
specimens from 14 patients removed at the time of OLT and autopsy tissues from 3
of the 14 were examined histologically using hematoxylin and eosin and Congo red
stained sections. The extent of amyloid deposits was evaluated,
semiquantitatively graded from negative to marked, and correlated with clinical
course and patient outcome. Amyloid deposits were consistently seen in hilar and
vagus nerves. Liver lobular involvement was minimal in 1 and absent in the other
13 cases, with portal arterial amyloid deposits seen in 7 cases. At autopsy,
extensive amyloid deposition in the heart was seen in all 3 cases with
involvement of the conduction system. The extent of amyloid deposition at OLT did
not correlate with the duration of symptoms before OLT or patient outcome after
OLT. In conclusion, liver parenchymal involvement in FAP is minimal, and these
explants are suitable for grafting in non-FAP patients. The recipients of such
grafts must be carefully observed for the development of any amyloid-related
disease, particularly cardiomyopathy. Of the tissues removed at OLT, the
histopathologic confirmation of FAP is most consistently made by the examination
of hilar and vagus nerves.
PMID- 10665912
TI - Loss of p16/CDKN2A tumor suppressor protein in gastric adenocarcinoma is
associated with Epstein-Barr virus and anatomic location in the body of the
stomach.
AB - Gastric adenocarcinomas (n = 125) were analyzed by immunohistochemistry for the
presence of p16, the CDKN2A gene product. This protein was lost in 31 of 125
cases (25%), and loss was associated with location of the tumor in the body of
the stomach (P = .001). Loss of p16 was also associated with the presence of
Epstein-Barr virus (EBV) in tumor cells as determined by in situ hybridization (P
= .022). This effect may relate to anatomic site, because EBV-associated tumors
originate more frequently in the body of the stomach. When p16 status was
evaluated for ethnic origin of the patient (non-Hispanic white, Hispanic, or
black), a strong trend (P = .057) was found for African-American patients to have
fewer p16-negative tumors than other patients. This also may relate to anatomic
location, because fewer tumors from black patients arose in the body of the
stomach (P = .022). No significant associations were detected between p16 status
and histological subtype (intestinal v diffuse), the presence of microsatellite
instability, grade or stage of the tumor, or age, gender, or survival of the
patient. In conclusion, p16 loss is quite common in gastric adenocarcinoma, and
such loss is more common in EBV-infected tumors arising in the body of the
stomach.
PMID- 10665913
TI - Morphometric analysis of the "mucocellular layer" overlying colorectal cancer and
normal mucosa: relevance to exfoliation and stool screening.
AB - Characterization of shed cell elements entrapped within the colorectal surface
mucus would be valuable to the study of exfoliation and candidate stool screening
markers. Yet, surprisingly little is known about the cellular composition of this
"mucocellular layer" (MCL). Our aim was to describe and compare the
histomorphometry of the MCL that overlies colorectal cancer (CRC) and normal
mucosa. From tissue archives, 20 resected CRC specimens yielding perpendicular
cuts of both tumor surface and adjacent normal mucosa were consecutively
selected. MCL thickness and cell number were determined in triplicate using an
ocular micrometer. Cellular elements within the MCL were characterized on
paraffin sections by immunohistochemistry. Mean cell density was much greater in
the MCL over CRC (2,639 +/- 2,178 per mm2) than over normal mucosa (184 +/- 395
per mm2), p < .001. Robust-appearing colonocytes and inflammatory cells
predominated in the hypercellular MCL of CRC; the former retained expression of
tumor-associated antigens. In contrast, the sparsely scattered cells within the
normal MCL were typically apoptotic and of indeterminate lineage. Based on direct
observations from this first descriptive study of the colorectal MCL, luminal
shedding appears to be much greater from CRC than from normal mucosa.
PMID- 10665914
TI - Differential expression of thyroid transcription factor 1 in small cell lung
carcinoma and Merkel cell tumor.
AB - The distinction between metastatic small cell lung carcinoma (SCLC) and Merkel
cell tumor is difficult by routine histology, prompting the search for specific
markers that could separate these neoplasms. Thyroid transcription factor 1 (TFF
1) is a homeodomain containing transcription factor expressed in the normal
airway epithelium. The expression of TTF-1 has also been shown in adenocarcinomas
and small cell carcinomas of the lung. However, the utility of TTF-1 to
differentiate between SCLC and Merkel cell tumor has not yet been investigated.
In this study, paraffin sections of 36 SCLCs and 21 Merkel cell tumors were
analyzed for the presence of immunoreactive TTF-1 and cytokeratin 20 (CK20), a
marker previously demonstrated in Merkel cell tumors. Monoclonal TTF-1 and CK20
antibodies were used with a biotin-streptavidin detection system. Immunostaining
for TTF-1 was observed in 97% of SCLCs and in no Merkel cell tumors.
Immunoreactivity for CK20 was demonstrated in 76% of Merkel cell tumors and 3% of
SCLCs. These data indicate that TTF-1 is a sensitive (97%) and specific (100%)
marker for SCLCs and can be used to differentiate SCLCs from Merkel cell tumors.
PMID- 10665915
TI - Solitary fibrous tumor of the lower urogenital tract: a report of five cases
involving the seminal vesicles, urinary bladder, and prostate.
AB - Solitary fibrous tumor (SFT) is not as site-restricted as once believed.
Initially described as a tumor of the pleura, SFT is now recognized at various
extrathoracic sites. We report 5 cases of extrapleural SFT involving the male
lower urogenital tract. The tumors involved the seminal vesicles (2 cases),
urinary bladder (2 cases), and the prostate (1 case). The patients with bladder
tumors were asymptomatic. The patients with seminal vesicle involvement presented
with hematuria or groin pain. The patient with prostate involvement presented
with urinary retention. The prostate tumor was large, and it could not be
completely excised because of its extensive spread beyond the prostate into the
pelvis. The other 4 tumors were completely excised, and none has recurred during
limited follow-up. By histological criteria, 4 of the tumors were benign, and 1
was malignant. Even though the classic histological features of SFT were well
developed in each case, all 5 tumors were initially misdiagnosed, including 3
benign tumors that were misclassified as sarcomas. These 5 cases confirm the male
lower genitourinary tract as yet another site of origin for SFTs, challenge the
notion that extrapleural SFTs invariably are benign, and draw attention to the
problem of recognizing SFTs when they arise in unexpected sites.
PMID- 10665916
TI - Impact of human immunodeficiency virus infection on the histological features of
chronic hepatitis C: a case-control study. The MULTIVIRC group.
AB - Hepatitis C virus (HCV) is frequently encountered in human immunodeficiency virus
(HIV)-infected patients because of common routes of transmission. Previous
studies suggested that HIV infection impaired the natural course of chronic
hepatitis C, with a more rapid progression to cirrhosis. However, these studies
did not assess the HIV infection impact on chronic hepatitis C by taking into
account the risk factors for liver fibrosis progression: alcohol, sex, age at the
contamination, and duration of HCV infection. We studied liver biopsy specimens
of 2 groups of 58 patients that were infected by both HCV and HIV or by HCV
alone. The 2 groups were matched according those risk factors, and liver biopsy
responses were evaluated with the METAVIR items. The METAVIR activity was higher
in HIV-positive than HIV-negative patients. Cirrhosis was more frequent: (1) in
HIV-positive patients with CD4 < or = 200 cells/microL (45%) than in HIV-negative
patients (10%) (P = .003), (2) in HIV-positive patients with CD4 < or = 200
cells/microL (45%) than in HIV-positive patients with CD4 > 200 cells/microL
(17%) (P = .04). These differences, which were linked to HIV status, might be
related to the enhanced HCV replication during HIV infection or other immune
mechanisms that need further studies.
PMID- 10665917
TI - The histological spectrum of visceral leishmaniasis caused by Leishmania infantum
MON-1 in acquired immune deficiency syndrome.
AB - Visceral leishmaniasis (VL) due to Leishmania infantum is endemic in Southern
France and can be considered as an opportunistic infection in patients with
acquired immunodeficiency syndrome (AIDS). Co-infection with Leishmania sp. and
human immunodeficiency virus (HIV) is emerging, but pathological findings of
leishmaniasis in AIDS have been poorly documented, and scattered case reports
have include morphological descriptions. The clinicopathologic analysis of 16
patients with HIV and VL were evaluated. The clinical presentation was
characteristic of VL, with fever, hepatosplenomegaly, and pancytopenia in 6
patients, and the diagnosis was confirmed by finding amastigotes of Leishmania
sp. in bone marrow smears and biopsy specimens. In 4 patients, the initial
diagnosis of VL was made fortuitously in gastrointestinal biopsies performed
systematically (3 patients) or in case of diarrhea (1 patient). In one duodenal
biopsy, Leishmania sp. and Mycobacteria sp. were associated. Liver biopsy allowed
the diagnosis of VL in 3 cases. Autopsy was performed in 9 patients, showing a
disseminated leishmaniasis with very unusual localizations (adrenal and heart) in
2 cases. Cutaneous leishmaniasis involvement was noted before (4 patients), at
the same time (2 patient), or after (1 patient) the diagnosis of VL. Inflammatory
infiltrates noted with Leishmania sp. infection were made by CD68 macrophages
with (8 patients) or without (8 patients) associated CD8 positive lymphocytes.
Immunoperoxidase study using polyclonal anti-Leishmania sp. antibodies
contributed to the diagnosis in all cases. Electron microscopy of 2 digestive
biopsy specimens showed the ultrastructural characteristics of Leishmania sp.
amastigotes. The zymodeme MON-1 of L infantum was identified by isoenzyme
electrophoresis in all patients. The mean of CD4 counts was 37/mm3 at the time of
diagnosis, and the mean duration before the death was 8 months. As shown in this
study, VL in AIDS can be diagnosed in gastrointestinal or liver biopsies.
Diagnosis of VL was made when the CD4 count was very low and was correlated with
a poor prognosis.
PMID- 10665918
TI - Placental pathology in malaria: a histological, immunohistochemical, and
quantitative study.
AB - To characterize the histological changes in malarial placentas and their
relationship with parity and maternal and cord parasitemias, we conducted a
histological study on 1,179 placentas from Ifakara, Tanzania, an area with
intense and perennial malaria transmission. Immunohistochemical and quantitative
studies for CD45, fibrin, and villous area were performed in 60 cases. Four
hundred fifteen placentas (35.2%) showed parasites (active infections); in 303 of
them, parasites co-existed with pigment covered by fibrin (chronic infections),
and in 112 only parasites were detected (acute infections). Four hundred seventy
five cases (40.3%) showed hemozoin deposition without parasites (past
infections). Of women with parasitized placentas, 46.3% did not show parasites in
the peripheral blood. Basal membrane thickening (P = .002), fibrinoid necrosis (P
= .004), and prominence of syncytial knots (P = .031) were associated with active
malarial infection. No quantitative differences for perivillous fibrin deposition
or villous area were found. The most significant association with active malarial
infection was intervillous infiltration by mononuclear inflammatory cells (P <
.001). Chronic infections were associated with the most severe changes,
particularly intervillous mononuclear inflammation (OR, 28.7; 95% CI = 16.0 to
51.5, P< .001). Past infections showed only minimal differences with noninfected
placentas. Primiparas showed chronic infections more frequently than multiparas
(52% v 15%, P < .001). They also showed significantly higher placental
parasitemias and intervillous inflammatory infiltrate. In conclusion, placental
histology is more sensitive than peripheral blood examination in detecting
malarial infection during pregnancy. Most malarial infections recover during
pregnancy, leaving few residual changes in the placenta. Intervillous
inflammation is the most frequent finding associated with malaria and is
especially severe in primiparas, suggesting that mechanisms other than
immunosuppression are responsible for the high susceptibility in this group.
PMID- 10665919
TI - Luminal contents of benign and malignant prostatic glands: correspondence to
altered secretory mechanisms.
AB - Recent changes in tissue fixation strategy, using glutaraldehyde, have clarified
the secretory mechanisms of the normal prostate identifying cytoplasmic prostatic
secretory granules, structures not preserved by formalin fixation. This normal
secretory mechanism was absent in most adenocarcinomas, depicting an important
metabolic change in transformed prostate cells. The current study further
investigates differences between benign and malignant prostate secretion and
relates them to the production of corpora amylacea by benign glands and
crystalloids or mucin by cancer. In all normal prostate cells examined (6 cases),
prostate secretory granules (PSG) were approximately 1-microm, brightly
eosinophilic granules filling the cytoplasm of secretory cells and released in
packets by a specialized apocrine cell structure. After apocrine decapitation and
luminal dispersal, some of the cytoplasmic and PSG remnants condensed to form
eosinophilic bodies (EB) with a glycoprotein rim and central protein core. EB
were observed adsorbing and layering onto the surface of prostatic corpora
amylacea representing their chief mode of enlargement. Biochemical analysis and x
ray diffraction studies confirmed sulfated glycosaminoglycans of similar
structure as the main constituent of both PSG and corpora amylacea. Peripheral
zone amphiphilic "dark cell" carcinoma (9 cases) contained almost no PSG, and
showed neither apical decapitation nor EB formation, but mucin secretion was
frequently detected. Crystalloids that share the same staining characteristics
and sulfur content as PSG and corpora amylacea were identified in 3 selected
"clear cell" carcinomas, all of which showed at least focal PSG secretion. The
recognition of these differing secretory mechanisms and their deviation from
normal further defines the histological criteria and spectrum of prostate
malignancy.
PMID- 10665920
TI - Recurrent hepatitis B, hepatitis C, and combined hepatitis B and C in liver
allografts: a comparative pathological study.
AB - Although recurrence of viral hepatitis in liver transplants is common, data
comparing recurrent hepatitis B (HB), hepatitis C (HC), and co-existing dual
hepatitis B and C (HB&C) are sparse. Posttransplantation liver biopsies, along
with molecular, serological, immunohistochemical, and clinical data from 27
patients with pretransplantation diagnosis of chronic viral hepatitis, were
reviewed. The patients were placed into 4 groups: Group I, with
pretransplantation HB (n = 8); group II, with pretransplantation HC (n = 10);
group III with pretransplantation HC and anti-HB surface or core antibody (n =
4); and group IV, with pretransplantation HB&C (n = 5). The histopathologic
findings and patient outcome were compared in the 4 groups. A high rate of
recurrence of viral hepatitis was seen for all 4 groups: Group I = 100%, group II
= 90%, Group III = 100%, and group IV = 80%, with the mean (median) recurrence
time of 308 (224), 82 (52), 61 (64), and 125 (70) days, respectively. The number
of deaths (their median survival times) were: group I = 4 (374 days), group II =
4 (794 days), group III = 1 (1,143 days), and group IV = 5 (448 days). The
earliest histological findings of lobular injury was the presence of acidophil
bodies and Kupffer cell hyperplasia, the latter being more prominent in recurrent
HC cases. Recurrent HB presented in 2 forms: early (before 150 days) with poor
survival and with either severe necroinflammatory histology or with features of
fibrosing cholestatic hepatitis, and delayed (after 150 days), with mild necro
inflammatory activity and prolonged survival. HC with or without anti-HB
antibodies had early recurrence, but the course was slowly progressive. Patients
with HB&C had recurrence of both viruses; however, the course was dictated by HB
virus.
PMID- 10665921
TI - Chromosomal alterations in ulcerative colitis-related and sporadic colorectal
cancers by comparative genomic hybridization.
AB - Both ulcerative colitis (UC)-related and sporadic colorectal cancers are thought
to evolve through a multistep process of genomic instability, accumulation of
genomic alterations, and clonal expansion. This process may involve different
genomic changes in UC-related cancers than in sporadic cancers because of the
origin of UC-related cancers in an inflammatory field. This study was designed to
define the specific genomic events occurring in UC-related cancers. Comparative
genomic hybridization (CGH) was performed on 32 UC-related and 42 stage-matched
sporadic colorectal cancers. The mean number of chromosomal alterations per case
was similar in the UC-related and sporadic tumor groups (8.6 in UC, 8.1 in
sporadic). The 2 tumor groups shared many chromosomal alterations: losses on 18q
(78% UC v69% sporadic), 8p (53% v50%), 17p (44% v57%), and gains on 8q (63%
v45%), 20q (44% UC v67%), and 13q (44% UC v38%). However, differences in the
frequency and timing of specific alterations were observed. Chromosome 5q was
lost in 56% of UC-related but in only 26% of sporadic cancers. Alterations of
chromosome 8 were associated with stage progression in UC-related, but not in
sporadic cancers. In contrast, 18q loss was associated with stage progression in
sporadic cancers only. Thus, differences in the frequency and timing of
individual chromosomal alterations suggest that genetic progression in these 2
tumor groups may follow multiple pathways.
PMID- 10665922
TI - Incidence of p14ARF gene deletion in high-grade adult and pediatric astrocytomas.
AB - The INK4a-ARF locus encodes 2 separate proteins through differential splicing of
alternative first exons to produce p16INK4a (exon 1alpha) and p14ARF (exon 1beta)
products in human cells. The p16INK4a protein inhibits the cyclin D-dependent
kinases (CDK) that control the phosphorylation of the Rb protein and cell
proliferation. The p14ARF gene product can complex with and sequester the MDM2
protein within the nucleus, thus modulating the activity of the p53 protein. Loss
of p16INK4a expression would disrupt the retinoblastoma (Rb)/p16INK4a/cyclin D
dependent kinase (CDK4) pathway, whereas loss of p14ARF expression would
inactivate both the Rb and p53/ MDM2/p14ARF pathways through MDM2, which can
complex with either Rb or p53. Loss of the p16INK4a gene on 9p21 has been
documented in a wide range of human tumors, including one third of glioblastomas.
However, in tumors showing homozygous loss of exon 2 of the p16INK4a gene, loss
of exon 1beta of the p14ARF gene has not been established. In this study, we have
assessed deletion of the p14ARF gene in 29 pediatric and 107 adult high-grade
astrocytomas and 9 glioma cell lines, using multiplex PCR analysis for exon
1beta. We found homozygous deletions for exon 1alpha and exon 1beta in 3 of 29
(10%) of the pediatric cases (2 grade III, 1 grade IV), 25 of 107 (23%) of the
adult cases (6 grade III and 19 grade IV), and 8 of 9 (89%) of the glioma cell
lines. Therefore, loss of the INK4a-ARF locus in high-grade astrocytomas may
contribute to the highly malignant behavior and treatment resistance of these
tumors through elimination of multiple checkpoint cell cycle control proteins.
PMID- 10665923
TI - Chagas' disease of the cervix uteri in a patient with acquired immunodeficiency
syndrome.
AB - A 27-year-old woman with the acquired immunodeficiency syndrome and endocervical
Chagas' disease is reported. The patient was a cocaine addict, and her sexual
partner was also human immunodeficiency virus (HIV)-positive. Her past medical
history included a son who died 3 days after birth due to congenital Chagas'
disease. Seven years later, through a cervical biopsy, a reactivation of Chagas'
disease was diagnosed. Giant cells with typical amastigotes were seen; they
strongly stained with antibodies against Trypanosoma cruzi. The patient died 5
months later of an acute chagasic myocardiopathy. To our knowledge, this is the
first report of this parasitosis in the cervix uteri.
PMID- 10665924
TI - Nodular glomerulosclerosis secondary to mu heavy chain deposits.
AB - mu heavy chain deposition disease is very rare. We report the first case of
glomerulonephritis in a woman without evidence of hematopoietic malignancy.
Nodular glomerulosclerosis and monotypic mu heavy chain mesangial deposits were
identified by immunofluorescence without kappa or lambda deposits. Electron
microscopy showed fibrillar mesangial deposits of 16-18 nm in diameter. Serum
immunoglobulins, cryoglobulins, serum immunoelectrophoresis, and immunofixation,
bone marrow biopsy, and Bence Jones proteins in urine were negative. The patient
has stable renal disease and is free of malignancy 6 years after the initial
occurrence of proteinuria.
PMID- 10665925
TI - Benign metastasizing leiomyoma: a cytogenetically balanced but clonal disease.
AB - Benign metastasizing leiomyoma (BML) is a rare condition, characterized by the
occurrence of multiple smooth-muscle nodules, most often located in the lung
after previous hysterectomy because of histologically benign appearing leiomyoma.
Although the condition resembles a metastatic process, case studies provided
evidence that it may be the result of an intravenous leiomyomatosis or an
independent and multifocal smooth-muscle proliferation. Comparative genomic
hybridization and X-chromosome inactivation analysis were used in a case of BML
to determine whether pulmonary and uterine tumors are related one to another. A
balanced karyotype, previously reported in leiomyomas and an identical X
chromosome inactivation pattern found in all tumorlets, is most consistent with a
monoclonal origin of both uterine and pulmonary tumors and the interpretation
that pulmonary lesions are metastatic.
PMID- 10665926
TI - Receptor-associated protein is important for normal processing of megalin in
kidney proximal tubules.
AB - The receptor-associated protein (RAP) has been identified as a chaperone
regulating the expression and processing of the LDL receptor-related protein. RAP
also binds to the related 600-kD multiligand endocytic receptor megalin expressed
in many absorptive epithelia including renal proximal tubule. The present study
examines the effect of RAP gene disruption on megalin expression and subcellular
distribution in the proximal tubule as well as the effect on tubular protein
reabsorption. It is shown that RAP is important for the normal expression and
function of megalin. Megalin expression was reduced to approximately 23%
estimated by immunoblotting and supported by immunocytochemistry and by the
amount of megalin recovered by RAP affinity chromatography. Light- and electron
microscope immunocytochemistry as well as analyses on separated membrane
fractions showed significant changes in the subcellular distribution of megalin.
A significant reduction in the normal brush border labeling was observed in
association with increased labeling of rough endoplasmic reticulum and the smooth
paramembranous endoplasmic reticulum along the basolateral membranes. RAP
deficiency was associated with changes in urinary protein composition, enabling
the identification of alpha-amylase as a new ligand for megalin. In addition, an
increased excretion of vitamin D-binding protein, a recently identified ligand to
megalin, was observed supporting changes in tubular protein reabsorption. The
present data show that RAP is of crucial importance for normal processing and
function of megalin, suggesting a chaperone-like function of this protein in the
kidney proximal tubule.
PMID- 10665927
TI - Effect of chronic metabolic acidosis on calbindin expression along the rat distal
tubule.
AB - Calbindin D28k has been reported to be involved in the transcellular calcium
transport along the rat distal tubule. It has also been shown that chronic
metabolic acidosis (CMA) induces significant hypercalciuria. The present study
investigated whether CMA affects the mRNA and the protein expression of calbindin
D28k along isolated distal tubule (DT) of rats. The animals were made acidotic by
adding 0.28 mol/L NH4Cl to the drinking water for 7 d. This maneuver was
associated with an increase in plasma ionized calcium. Inulin clearance
experiments demonstrated that metabolic acidosis did not affect GFR, but it
significantly increased both total and fractional urinary calcium excretion. To
define the role of calbindin D28k, total RNA was extracted from DT, identified,
and microdissected from collagenase-treated kidneys. cDNA was synthesized from
RNA using reverse transcriptase and oligo(dT)(12-18) primers. Calbindin D28k mRNA
abundance was semiquantified by a competitive reverse transcription-PCR, using an
internal standard of cDNA that differed from the wild-type calbindin D28k by a
deletion of 86 bp. The reverse transcription-PCR was performed starting from the
same amount of total RNA. For each set of experiments, control and acidotic rats
were studied in parallel. The identity of the DT was further verified by the
presence of the thiazide-sensitive NaCl cotransporter (rTSC1) mRNA. Calbindin
D28k mRNA abundance was 0.89 +/- 0.21 amol/ng total RNA in DT of CMA rats (n = 5)
compared with 0.30 +/- 0.12 amol/ng total RNA of control rats (n = 5) (P < 0.05).
Using specific rabbit polyclonal anti-calbindin D28k antibody, Western blotting
was performed starting from thin slices of outer cortex. Densitometric analysis
revealed that in acidotic rats (n = 7) there was a 17 +/- 5% (P < 0.05) increase
in calbindin D28k protein abundance compared with controls (n = 7). These results
indicate that in the rat, ammonium chloride loading induces an increase in
filtered ionized calcium load that is associated with a significant upregulation
of calbindin D28k both at the mRNA and protein level. These last effects will
help to reduce the concomitant hypercalciuria, thus mitigating the consequence of
CMA on calcium metabolism.
PMID- 10665928
TI - Ischemic acute renal failure induces differential expression of small heat shock
proteins.
AB - AlphaB-crystallin and heat shock protein (hsp) 25 are structurally and
functionally related small stress proteins induced by a variety of insults,
including heat and ischemia. Cytoprotection by these two hsp is thought to result
from molecular chaperoning and/or cytoskeletal stabilization. Because renal
ischemia is characterized by disruption of the renal tubular cell actin
cytoskeleton, this study was conducted to determine the localization and quantify
the expression and phosphorylation of both hsp in renal cortex, isolated
glomeruli, outer medulla, and inner medulla of rats after bilateral renal
ischemia. Sham-operated kidneys had similarly small amounts of hsp25 and alphaB
crystallin in cortex and glomeruli, with substantially greater amounts of alphaB
crystallin versus hsp25 in outer and inner medulla. Ischemia resulted in
significantly increased hsp25 (and hsp70i) but variable alphaB-crystallin levels
in cortex and outer medulla, and progressively decreased glomerular hsp25
phosphorylation. In sham-operated kidneys, hsp25 localized to glomeruli, vessels,
and collecting ducts, with alphaB-crystallin primarily in medullary thin limbs
and collecting ducts. After ischemia, hsp25 accumulated in proximal tubules in
cortex and outer medulla, while alphaB-crystallin labeling became nonhomogeneous
in outer medulla, and increased in Bowman's capsule. It is concluded that: (1)
There is striking differential expression of hsp25 and alphaB-crystallin in
various renal compartments; and (2) Renal ischemia results in differential
accumulation of hsp25 and alphaB-crystallin, with hsp25 part of a generalized
stress response in renal proximal tubular cells, which may play a role in
recovery from ischemia-induced actin filament disruption.
PMID- 10665929
TI - Parathyroid hormone stimulates extracellular signal-regulated kinase (ERK)
activity through two independent signal transduction pathways: role of ERK in
sodium-phosphate cotransport.
AB - Parathyroid hormone (PTH), a major physiologic regulator of proximal renal tubule
cell sodium-phosphate cotransport, stimulates several signal transduction
pathways including extracellular signal-regulated kinases (ERK). The physiologic
role of PTH-stimulated ERK is unknown. The purpose of the present study was to
identify signaling components involved in PTH-stimulated ERK activity and to
determine the role of PTH-stimulated ERK activity in regulation of phosphate
transport. PTH-stimulated ERK activity was measured in opossum kidney (OK) cell
lysates as phosphorylation of myelin basic protein by an in vitro kinase assay.
PTH stimulated a dose-dependent increase in ERK activity with a peak at 10(-7) M.
The time course was biphasic with an early peak at 10 min and a later peak at 20
min. Pretreatment of OK cells with the nonreceptor tyrosine kinase inhibitors
genistein and herbimycin A or with the phosphatidylinositol 3-kinase (PI-3K)
inhibitors wortmannin and LY294002 blocked the early and late peaks of PTH
stimulated ERK activity. Pretreatment with the protein kinase C inhibitor
calphostin C blocked only the later phase of PTH-stimulated ERK. To determine the
role of ERK in regulation of phosphate transport, PTH inhibition of phosphate
uptake and PTH regulation of sodium-phosphate cotransporter (NaPi-4) expression
were measured in OK cells pretreated with the MEK inhibitor PD098059. PD098059
significantly attenuated PTH inhibition of phosphate uptake but did not prevent
PTH downregulation of NaPi-4. It is concluded that PTH stimulates ERK through two
signal transduction pathways: an early pathway dependent on tyrosine kinase and
PI-3K and a late pathway dependent on protein kinase C. PTH-stimulated ERK
regulates phosphate transport by a mechanism other than downregulation of NaPi-4
expression.
PMID- 10665930
TI - Differential activation of mitogen-activated protein kinases in experimental
mesangioproliferative glomerulonephritis.
AB - Multiple extracellular mitogens are involved in the pathogenesis of proliferative
forms of glomerulonephritis (GN). In vitro studies demonstrate the pivotal role
of mitogen-activated protein (MAP) kinases in the regulation of cellular
proliferation. This study was conducted to examine whether these kinases, as a
convergence point of mitogenic stimuli, are activated in mesangioproliferative GN
in vivo. Therefore, anti-Thy1 GN was induced in rats using a monoclonal anti
Thy1.1 antibody (OX-7). Whole cortical tissue as well as isolated glomeruli were
examined at different time points using kinase activity assays and Western blot
analysis. A maximal increase in the number of glomerular mitotic figures (9.7
fold) was demonstrated 6 d after injection of the anti-Thy1.1 antibody. In
parallel with this finding, a significant increase in cortical, and more
dramatically glomerular, activity of extracellular signal-regulated kinase (ERK)
was detected. Maximal activation of ERK was detectable on day 6. This activation
of ERK was accompanied by an increase in the expression of MEK (MAP kinase/ERK
kinase), the ERK-activating kinase. A marked induction of glomerular apoptosis at
2 h after injection of the anti-Thy1.1 antibody, which subsided subsequently, was
demonstrated using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin
nick end labeling assay as well as staining for single-stranded DNA. However, no
significant activation of stress-activated protein kinase or p38 MAP kinase, both
MAP kinases that are suggested to induce apoptosis and to inhibit cellular
growth, was detectable at this early time point. Rather, on day 6 a dramatic
decrease in the activity of p38 MAP kinase, which might have contributed to the
overshooting glomerular cellular proliferation, was observed. Treatment of rats
with heparin blunted glomerular proliferation as well as ERK activation and
restored p38 MAP kinase activity. These observations point to ERK and p38 MAP
kinase as putative mediators of the proliferative response in
mesangioproliferative GN and suggest that upregulation of MEK is involved in the
long-term regulation of ERK in vivo.
PMID- 10665931
TI - Absence of CD89, polymeric immunoglobulin receptor, and asialoglycoprotein
receptor on human mesangial cells.
AB - IgA nephropathy (IgAN) is characterized by raised serum IgA and predominant
mesangial IgA deposits of polymeric nature. The expression of IgA receptor
molecules in white blood cells and glomerular mesangial cells has recently
attracted much attention in relation to the uptake of IgA by these cells. This
study investigates the expression of IgA Fc receptor (Fc alphaR1 or CD89),
asialoglycoprotein receptor (ASGPR), and polymeric Ig receptor (pIgR) in cultured
glomerular mesangial cells. Using a sensitive nested reverse transcription-PCR,
mRNA encoding for Fc alphaR1, pIgR, or the H2 chain of ASGPR was not demonstrated
on human mesangial cells. U937, HepG2, and HT29 cell lines, used as positive
controls, strongly expressed the Fc alphaR1, ASGPR, and pIgR mRNA, respectively,
under similar experimental conditions. Flow cytometry also demonstrated the
presence of surface proteins for Fc alphaR1, ASGPR, and pIgR on the respective
control cell lines but not on human mesangial cells. Expression of Fc alphaR1
mRNA on cultured U937 cells was upregulated by tumor necrosis factor-alpha.
However, tumor necrosis factor-alpha, interleukin-1beta, or transforming growth
factor-beta failed to induce the expression of Fc alphaR1 on human mesangial
cells. Human serum IgA or secretory IgA bound to human mesangial cells, HepG2, or
the U937 cell line in a dose-dependent manner. The binding of purified IgA to
human mesangial cells was not blocked by preincubation with human IgG, IgM,
orosomucoid, asialo-orosomucoid, anti-CD89 antibody (My43), or anti-secretory
component antibody. The present study concluded that there was an absence of Fc
alphaR1, ASGPR, or pIgR on human mesangial cells. These findings suggest that the
predominant binding of human IgA to human mesangial cells is mediated by other
mechanisms.
PMID- 10665932
TI - Central role for interferon-gamma receptor in the regulation of renal MHC
expression.
AB - The role of the interferon-gamma (IFN-gamma) receptor 1 (IFN-gammaR1) was
investigated in the regulation of MHC expression in kidney in the basal state, in
response to potent inflammatory stimuli, and after renal injury. In this study,
MHC regulation in mice lacking IFN-gammaR due to targeted disruption of the IFN
gammaR1 gene (GRKO mice) was compared with regulation in 129Sv/J mice with wild
type IFN-gammaR1 genes. Basal class I expression was reduced by approximately 45%
in kidneys of GRKO mice, while basal class II expression was confined to
interstitial cells and was not reduced in GRKO kidneys. Recombinant IFN-gamma
administration induced widespread expression of class I and II in renal tubules,
arterial endothelium, and glomeruli of 129Sv/J mice, but produced no change in
kidneys of GRKO mice. Potent systemic inflammatory stimuli (injections of
allogeneic cells, skin sensitization with oxazolone, and injection of bacterial
lipopolysaccharide) significantly induced both class I and class II expression in
129Sv/J mice, but not in GRKO mice. Acute renal injury increased local expression
of class I and II in both 129Sv/J and GRKO mice, but the induction in GRKO mice
was reduced compared with 129Sv/J mice. Thus, the IFN-gamma receptor plays a
unique and nonredundant role in the regulation of renal MHC in the response to
inflammation, in the response to renal injury, and in the basal state.
PMID- 10665933
TI - Interleukin-10 inhibits macrophage-induced glomerular injury.
AB - The ability of interleukin-10 (IL-10) to inhibit macrophage recruitment,
activation, and proliferation in vivo was studied in a macrophage-mediated, but T
cell-independent, passive anti-glomerular basement membrane antibody-induced
model of glomerulonephritis (GN) in rats. Treatment with recombinant murine IL-10
resulted in dose-dependent reductions in proteinuria (high dose: 16 +/- 1 mg/24
h; low dose: 30 +/- 2 mg/24 h; control treatment: 69 +/- 6 mg/24 h; normal: 7 +/-
1 mg/24 h) and glomerular macrophage recruitment (high dose: 1.8 +/- 0.1
macrophages per glomerular cross section [c/gcs]; low dose: 5.5 +/- 0.2 c/gcs;
control treatment: 12.1 +/- 0.6 c/gcs). Macrophage and intrinsic glomerular cell
proliferation were reduced at both doses of IL-10, as was glomerular expression
of P-selectin and monocyte chemoattractant protein-1. IL-10 treatment also
resulted in a dose-dependent reduction of macrophage activation as indicated by
MHC class II and IL-1beta expression. Glomerular nitrite production by isolated
cultured glomeruli was reduced after IL-10 treatment in vivo (high dose: 2.3 +/-
2.3 nmol/10(4) glomeruli per 72 h; low dose: 28 +/- 5 nmol/10(4) glomeruli per 72
h; control treatment: 82 +/- 11 nmol/10(4) glomeruli per 72 h). Tumor necrosis
factor-alpha production was abolished by high-dose treatment and reduced by the
lower dose (3.8 +/- 3.8 pg/10(4) glomeruli per 72 h; control treatment: 249 +/-
23 pg/10(4) glomeruli per 72 h). These studies demonstrate that IL-10 directly
attenuates glomerular macrophage recruitment, activation, and proliferation in
vivo and can significantly attenuate macrophage-mediated GN independent of any
effects on T cells.
PMID- 10665934
TI - Nephrocystin: gene expression and sequence conservation between human, mouse, and
Caenorhabditis elegans.
AB - Juvenile nephronophthisis, an autosomal recessive cystic kidney disease, is the
primary genetic cause for chronic renal failure in children. The gene (NPHP1) for
nephronophthisis type 1 has recently been identified. Its gene product,
nephrocystin, is a novel protein of unknown function, which contains a src
homology 3 domain. To study tissue expression and analyze amino acid sequence
conservation of nephrocystin, the full-length murine Nphp1 cDNA sequence was
obtained and Northern and in situ hybridization analyses were performed for
extensive expression studies. The results demonstrate widespread but relatively
weak NPHP1 expression in the human adult. In the adult mouse there is strong
expression in testis. This expression occurs specifically in cell stages of the
first meiotic division and thereafter. In situ hybridization to whole mouse
embryos demonstrated widespread and uniform expression at all developmental
stages. Amino acid sequence conservation studies in human, mouse, and
Caenorhabditis elegans show that in nephrocystin the src-homology 3 domain is
embedded in a novel context of other putative domains of protein-protein
interaction, such as coiled-coil and E-rich domains. It is concluded that for
multiple putative protein-protein interaction domains of nephrocystin, sequence
conservation dates back at least to Caenorhabditis elegans. The previously
described discrepancy between widespread tissue expression and the restriction of
symptoms to the kidney has now been confirmed by an in-depth expression study.
PMID- 10665935
TI - Combined mycophenolate mofetil and losartan therapy arrests established injury in
the remnant kidney.
AB - Previously it was shown that early treatment with mycophenolate mofetil (MMF)
attenuated renal inflammation, glomerulosclerosis (GS), and interstitial
expansion in the 5/6 ablation (NX) model. Angiotensin II antagonists also
mitigate renal injury in NX, presumably by lowering glomerular pressure (P(GC)).
This study investigated: (1) whether combined MMF/angiotensin II antagonists
treatment affords superior protection compared with the respective monotherapies;
and (2) whether this association is effective even when instituted late in the
course of the disease. Adult male Munich-Wistar rats underwent NX, remaining
untreated for 30 d. BP, albuminuria, and the extent of GS, interstitial
expansion, and macrophage infiltration were then determined in 17 rats. The
remaining 118 rats received either inert vehicle or one of the following: MMF, 10
mg/kg by gavage once daily; losartan potassium (L), 20 mg/dl in drinking water;
or combined MMF/L treatment. Sixty days after ablation, untreated NX rats
exhibited marked glomerular hypertension, which was attenuated by MMF and, more
effectively, by either L or combined MMF/L treatment. At 120 d, hypertension and
albuminuria were worsened in untreated NX rats, which exhibited intense
macrophage infiltration and severe glomerular and interstitial disease. L and, to
a lesser extent, MMF monotherapies attenuated these abnormalities, without
preventing their progression. In rats given combined MMF/L therapy, macrophage
infiltration, GS, and interstitial expansion remained at pretreatment levels. By
acting on two distinct pathogenic mechanisms, combined MMF/L treatment arrested
established renal injury in the NX model. Further investigation is needed to
determine whether this association can prevent renal scarring in other models and
in human disease.
PMID- 10665936
TI - A mouse model of renal tubular injury of tyrosinemia type 1: development of de
Toni Fanconi syndrome and apoptosis of renal tubular cells in Fah/Hpd double
mutant mice.
AB - Hereditary tyrosinemia type 1 (HT1) (McKusick 276700), a severe autosomal
recessive disorder of tyrosine metabolism, is caused by mutations in the
fumarylacetoacetate hydrolase gene Fah (EC 3.7.1.2), which encodes the last
enzyme in the tyrosine catabolic pathway. HT1 is characterized by severe
progressive liver disease and renal tubular dysfunction. Homozygous disruption of
the gene encoding Fah in mice causes neonatal lethality (e.g., lethal Albino
deletion c14CoS mice), an event that limits use of this animal as a model for
HT1. A new mouse model was developed with two genetic defects, Fah and 4
hydroxyphenylpyruvate dioxygenase (Hpd). The Fah-/- Hpd-/- mice grew normally
without evidence of liver and renal disease, and the phenotype is similar to that
in Fah+/+ Hpd-/- mice. The renal tubular cells of Fah-/- Hpd-/- mice,
particularly proximal tubular cells, underwent rapid apoptosis when
homogentisate, the intermediate metabolite between HPD and FAH, was administered
to the Fah-/- Hpd-/- mice. Simultaneously, renal tubular function was impaired
and Fanconi syndrome occurred. Apoptotic death of renal tubular cells, but not
renal dysfunction, was prevented by pretreatment of the animals with YVAD, a
specific inhibitor of caspases. In the homogentisate-treated Fah-/- Hpd-/- mice,
massive amounts of succinylacetone were excreted into the urine, regardless of
treatment with inhibitors. It is suggested that apoptotic death of renal tubular
cells, as induced by administration of homogentisate to Fah-/- Hpd-/- mice, was
caused by an intrinsic process, and that renal apoptosis and tubular dysfunctions
in tubular cells occurred through different pathways. These observations shed
light on the pathogenesis of renal tubular injury in subjects with FAH
deficiency. These Fah-/- Hpd-/- mice can serve as a model in experiments related
to renal tubular damage.
PMID- 10665937
TI - Effects of tetrahydrobiopterin on endothelial dysfunction in rats with ischemic
acute renal failure.
AB - The role of nitric oxide (NO) in ischemic renal injury is still controversial. NO
release was measured in rat kidneys subjected to ischemia and reperfusion to
determine whether (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4), a cofactor of NO
synthase (NOS), reduces ischemic injury. Twenty-four hours after bilateral renal
arterial clamp for 45 min, acetylcholine-induced vasorelaxation and NO release
were reduced and renal excretory function was impaired in Wistar rats.
Administration of BH4 (20 mg/kg, by mouth) before clamping resulted in a marked
improvement of those parameters (10(-8) M acetylcholine, delta renal perfusion
pressure: sham-operated control -45 +/- 5, ischemia -30 +/- 2, ischemia + BH4 -43
+/- 4%; delta NO: control +30 +/- 6, ischemia + 10 +/- 2, ischemia + BH4 +23 +/-
4 fmol/min per g kidney; serum creatinine: control 23 +/- 2, ischemia 150 +/- 27,
ischemia + BH4 48 +/- 6 microM; mean +/- SEM). Most of renal NOS activity was
calcium-dependent, and its activity decreased in the ischemic kidney. However, it
was restored by BH4 (control 5.0 +/- 0.9, ischemia 2.2 +/- 0.4, ischemia + BH4
4.3 +/- 1.2 pmol/min per mg protein). Immunoblot after low-temperature sodium
dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the dimeric form
of endothelial NOS decreased in the ischemic kidney and that it was restored by
BH4. These results suggest that the decreased activity of endothelium-derived NO
may worsen the ischemic tissue injury, in which depletion of BH4 may be involved.
PMID- 10665938
TI - The effect of discharge voltage on renal injury and impairment caused by
lithotripsy in the pig.
AB - The present study was designed to determine the effects of shock wave voltage
(kV) on lesion size and renal function induced by shock wave lithotripsy (SWL) in
the 6- to 8-wk-old pig. Each SWL-treated pig received 2000 shock waves at 12, 18,
or 24 kV to the lower pole calyx of one kidney. A group of sham SWL pigs served
as time controls. Bilateral GFR, renal plasma flow (RPF), and para-aminohippurate
(PAH) extraction were measured 1 h before and 1 and 4 h after SWL in all treated
and sham animals. The kidneys were removed at the end of each experiment for
morphometric analysis. The SWL-induced lesion increased significantly in size as
shock wave energy was increased from 12 to 24 kV. PAH extraction, a measure of
tubular function, was not significantly affected at 12 kV, was transiently
reduced at 18 kV, and was reduced for the duration of the experiment at 24 kV.
GFR and RPF, however, were significantly and similarly reduced at the 1 h post
SWL period at all three kilovolt levels. At the 4-h post-SWL period, both GFR and
RPF had returned to baseline levels. Lesion size and tubular injury were
correlated with changes in kilovoltage, while changes in renal hemodynamics were
already maximal at the lowest discharge voltage. These findings suggest that
renal microvessels are highly sensitive to shock waves and that frank injury to
tubules and vessels may be more closely related to discharge energy than is renal
blood flow.
PMID- 10665939
TI - Effect of gender on the progression of nondiabetic renal disease: a meta
analysis.
AB - There is previously published evidence that male gender is associated with a more
rapid rate of progression of nondiabetic chronic renal disease. However, some
investigators have concluded that no such association exists. To help resolve
this issue, a meta-analysis was performed using 68 studies that met defined
criteria and contained a total of 11,345 patients to evaluate the effect of
gender on the progression of nondiabetic chronic renal disease. The results
indicate that men with chronic renal disease of various etiologies show a more
rapid decline in renal function with time than do women.
PMID- 10665940
TI - Race is a major determinant of secondary hyperparathyroidism in uremic patients.
AB - In the general population, blacks have higher parathyroid gland mass and
circulating parathyroid hormone (PTH) levels than whites. This may predispose
black patients to more severe parathyroid disease when renal failure develops.
Therefore, racial differences in the severity of uremic hyperparathyroidism were
examined in a population of patients with end-stage renal disease (ESRD). Among
ESRD patients receiving hemodialysis or peritoneal dialysis, two or more values
of intact PTH (immunoradiometric assay, pg/ml) obtained at least 90 d apart were
available in 1270 prevalent cases (61.1% blacks, 51% males, and 31.1% diabetic),
including 466 incident cases with onset of ESRD after 1993. Maximum PTH levels
were analyzed as a function of race, gender, age, diabetic status, and levels of
serum calcium, phosphorus, alkaline phosphatase, and aluminum. Using a stepwise
multiple regression model, the determinants of maximum PTH in the order of their
importance were black race, serum phosphorus, absence of diabetes, younger age,
serum calcium, and female gender. The maximum PTH levels averaged 641.7 in blacks
and 346.0 in whites after adjusting for age, gender, diabetic status, serum
calcium, and phosphorus (P < 0.0001). In blacks compared with whites, the odds
ratio (95% confidence interval) for adynamic bone disease (maximum PTH <150
pg/ml) was 0.26 (0.17 to 0.41), whereas the odds ratio for hyperparathyroid bone
disease (mean PTH >500 pg/ml) was 4.4 (2.10 to 9.25). Race is a major independent
determinant of uremic secondary hyperparathyroidism. Among ESRD patients, blacks
may be at an increased risk for hyperparathyroid bone disease and whites for
adynamic bone disease.
PMID- 10665941
TI - Increasing the hematocrit has a beneficial effect on quality of life and is safe
in selected hemodialysis patients. Spanish Cooperative Renal Patients Quality of
Life Study Group of the Spanish Society of Nephrology.
AB - Target hematocrit/hemoglobin values in dialysis patients are still controversial.
The Spanish Cooperative Renal Patients Quality of Life Study Group (including 34
hemodialysis units) conducted a prospective, 6-mo study of the effect on patient
functional status and quality of life of using epoetin to achieve normal
hematocrit in hemodialysis patients with anemia. The possible adverse effects of
increased hematocrit, patient hospitalization, and epoetin requirements were also
studied. The study included 156 patients (age range, 18 to 65 yr). Given the
minimal experience in the safety of increasing hematocrit in dialysis patients to
normal levels with epoetin, stable patients on hemodialysis who had received
epoetin treatment for at least 3 mo and had a stable hemoglobin level of > or = 9
g/dl were included in the study. Patients with antecedents of congestive cardiac
failure, ischemic cardiopathy, diabetes mellitus, uncontrolled hypertension,
cerebrovascular accident or seizures, malfunction of the vascular access or
severe comorbidity (defined by a comorbidity index), and those over 65 yr of age
were excluded from the study. Quality of life was measured with the Sickness
Impact Profile (SIP) and Karnofsky scale. Patients completed questionnaires at
home at onset and conclusion of the 6-mo study. Mean hematocrit increased from
30.9 to 38.4% and hemoglobin from 10.2 to 12.5 g/dl during the study. Health
indicator scores improved significantly: mean Physical Dimension (SIP) from 5.38
to 4.1 (P < 0.005); mean Psychosocial Dimension from 9.2 to 7 (P < 0.001); mean
global SIP from 8.9 to 7.25 (P < 0.001); mean Karnofsky scale score from 75.6 to
78.4 (P < 0.01). (SIP is scaled so that lower scores represent better functional
status, and vice versa for the Karnofsky scale). Therefore, functional status and
quality of life improved with increased hematocrit. No deaths occurred. Three
patients (2%) were censored for hypertension and nine (5.7%) for thrombosis of
the vascular access. The cumulative probability of thrombosis of the vascular
access was 0.067. The average epoetin dose rose from 93 +/- 62 U/kg per wk at
onset to 141 +/- 80 U/kg per wk at conclusion, a 51% increase. The number of
patients hospitalized decreased and hospital lengths of stay were shorter during
the study period than in the same patients in the 6-mo period preceding the study
(P < 0.05). Nine patients (5.7%) had thrombosis of the vascular access. There
were no changes in the prevalence of arterial hypertension, but three patients
(2%) showed hypertension that was difficult to control. It is concluded that
normalization of hematocrit in selected hemodialysis patients, i.e., nondiabetic
patients without severe cardiovascular or cerebrovascular comorbidities, improves
quality of life and decreases morbidity without significant adverse effects.
PMID- 10665943
TI - Renal transplantation from non-heart beating donors: a promising alternative to
enlarge the donor pool.
AB - The aim of this study was to compare the survival and midterm function of kidneys
from non-heart beating donors (NHBD) with those of kidneys from heart beating
donors (HBD). From 1989 to 1998, 144 kidneys were procured from NHBD at the
Hospital Clinico San Carlos in Madrid, of which 95 were transplanted. The kidney
grafts were maintained from the moment of the diagnosis of cardiac arrest until
the time of procurement by cardiopulmonary bypass. There was no significant
difference in renal function and the number of rejection episodes between the
NHBD and HBD transplants. The NHBD kidneys showed a 5.73-fold increase in the
incidence of delayed graft function (adjusted relative risk 95% confidence
interval, 2.82 to 11.62). One- and five-year survival rates for NHBD grafts were
84.6 and 82.7%, respectively, compared with 87.5 and 83.9% for HBD (P = 0.5767).
Cox analysis showed that the predictive factors for worse NHBD graft survival
were type of NHBD donor and the occurrence of corticoresistant rejection. Ninety
of the NHBD organs were procured from subjects suffering irreversible cardiac
arrest on the street who were transferred to our center for the sole purpose of
donation. Fifty-four of these kidneys were transplanted and all showed primary
function. When a strict protocol is adhered to, the outcome of renal transplant
from NHBD compares well with that from HBD. It is believed that the high number
of organs obtained from subjects undergoing irreversible cardiac arrest on the
street might encourage the adoption of new criteria for the management of this
type of pathology with the ultimate goal of kidney donation.
PMID- 10665942
TI - Impact of cyclosporin A pharmacokinetics on the presence of side effects in
pediatric renal transplantation.
AB - Cyclosporin A (CsA) is a potent immunosuppressant that has many side effects,
including hypertrichosis, gingival hyperplasia, and tremor. To evaluate whether
there is a relationship between the CsA-pharmacokinetics (PK) and these side
effects, their presence and intensity were observed in 46 renal transplanted
children/adolescents during two regular visits, and the occurrence of the side
effects was correlated with CsA-PK. CsA doses had been unchanged for at least 6
mo. CsA blood concentrations were measured at time 0, and 1, 2, and 4 h after the
CsA morning dose. An abbreviated area under the curve (AUC) was calculated using
C0, C2, and C4. Hypertrichosis positively correlated with C2, C4, Cmax, and AUC.
An AUC > or = 4158 ng/ml per h was the best predictor for the presence of
hypertrichosis. Tremor was also positively correlated with C2, Cmax, and AUC. A
Cmax > or = 878 ng/ml was the best predictor for the appearance of tremor. These
values of Cmax and AUC are within the therapeutic range of CsA as demonstrated by
the studies of calcineurin inhibition by CsA. Gingival hyperplasia was not
associated with any of the CsA-PK studied parameters. However, it was associated
with the concomitant use of nifedipine. These data show that there is a
correlation between the CsA side effects and its pharmacokinetics and that it is
possible to decrease the incidence and intensity of such side effects by
monitoring the CsA-PK parameters, providing they are under or at the proposed
cutoff levels. Nifedipine should also be avoided to reduce the presence of
gingival hyperplasia.
PMID- 10665944
TI - Glycosaminoglycans: use in treatment of diabetic nephropathy.
PMID- 10665945
TI - Metabolic alkalosis.
PMID- 10665946
TI - Vasopressin: induced structural change in toad bladder luminal membrane. 1975.
PMID- 10665947
TI - Disease incidence in dairy herds in the southern highlands district of New South
Wales, Australia.
AB - The purpose of this study was to determine clinical disease incidence in eight
non-seasonally calving, pasture-fed dairy herds in the southern highlands
district of New South Wales. This was a longitudinal population study. The study
included all cows that calved between January 1994 and December 1995 and
consisted of 2111 lactation records from 1430 cows. The incidence of the more
common diseases were: calving-associated disorders, 18.0 cases per 100 calvings
(95% CI 16.4-19.8 cases per 100 calvings); metabolic disorders, 5.5 cases per 100
cow-yr at risk (95% CI 4.5-6.6 cases per 100 cow-yr at risk); reproductive-tract
disorders, 22.3 cases per 100 cow-yr at risk (95% CI 19.2-25.8 cases per 100 cow
yr at risk); udder disorders, 17.6 cases per 100 cow-yr at risk (95% CI 15.9-19.5
cow-yr at risk) and lameness, 3.7 cases per 100 cow-yr at risk (95% CI 2.9-4.7
cow-yr at risk). In agreement with dairy-cow disease-incidence studies conducted
elsewhere, disorders of the reproductive-tract and udder were the most frequent
clinical conditions encountered. These findings confirm that dairy herd-health
programs should emphasise the control of these two groups of disorders.
PMID- 10665948
TI - Temporal patterns of domestic and wildlife rabies in central Namibia stock
ranching area, 1986-1996.
AB - Eleven years (1986-1996) of wildlife- and domestic-rabies data from the
agriculture stock-ranching area of central Namibia were studied using time-series
analysis. Nine hundred and sixty three rabies cases were observed in domestic
ruminants (5.4 cases/mo), black-backed jackals (Canis mesomelas, 1.3 cases/mo),
domestic dogs (0.5 case/mo), and bat-eared foxes (Otocyon megalotis, 0.1
case/mo). The incidence of rabies for all species did not change significantly
over the whole study period. However, seasonal variations with an increase in the
number of cases between June and November of each year, as well as 34 yr cyclical
fluctuations were identified in domestic ruminants and black-backed jackals. The
black-backed jackal time-series variable was a significant predictor of the
domestic-ruminant and dog time-series variables. The rainfall seasonality
combined with the seasonal reproductive pattern of the black-backed jackal
appeared to be plausible explanations for the seasonal variations of rabies.
However, there was no overall significant correlation between the cyclical
weather fluctuations and the 3-4 yr cyclical rabies variations.
PMID- 10665949
TI - A stochastic partial-budget analysis of an experimental Pasteurella haemolytica
feedlot vaccine trial.
AB - A field trial compared a modified Pasteurella haemolytica biotype A serotype 1
leukotoxin vaccine to a commercial vaccine during March-July 1995 in a Natal
Midlands, South African, feedlot. Weaners/long weaners purchased by the feedlot
were allocated systematically into test vaccine and control vaccine groups of
1241 and 1240 head, respectively, and fed in groups of approximately 200 head.
Morbidity and mortality were monitored until the animals were marketed. Details
of pleuritis and pneumonia at veterinary meat inspection were recorded for 409
test-vaccinated and 424 control-vaccinated cattle. An increase in morbidity but
not mortality risk of respiratory disease was shown between test (13.8%
morbidity) and control (11.4% morbidity) groups. Cattle with a processing weight
<245 kg were 1.4 times more likely to develop respiratory diseases than cattle
with a processing weight > or =245 kg. Cattle bought on auction were 1.6 times
more likely to develop respiratory disease than cattle bought at private sales. A
partial farm budget incorporating Latin Hypercube sampling of uncertain variables
was done to obtain the distribution of possible financial outcomes if the test
vaccine were used. Impact (sensitivity) analyses indicated that median weight of
carcass cut away had the greatest impact on the profit margin. The partial farm
budget highlighted the importance of reducing sub-clinical lesions in a feedlot.
PMID- 10665950
TI - Soil type as a putative risk factor of ovine and caprine paratuberculosis
seropositivity in Spain.
AB - Relationships between soil type and ovine and caprine paratuberculosis in the
Avila region (central Spain) were evaluated using data from a cross-sectional
study of the most-important diseases of small ruminants in this Spanish region
between 1996 and 1997. Questionnaire data from 61 herds (38 ovine and 23 caprine)
and 1451 serum samples (1041 ovine and 410 caprine) were used. Herd
paratuberculosis (herds were scored as positive to paratuberculosis if any of the
serum samples was positive in an agar-gel immunodifussion) was the outcome of
interest, whereas soil type in the municipality where farms were located was the
predictor variable. Other variables related to soil and soil usage, and herd
size, replacement, main food production and animal species were also introduced
into the multivariable logistic regression. The final model contained only two
independent variables: the predictor variable soil type (coded as two dummy
variables ST-1 and ST-2) and herd size (dichotomized at the highest quartile).
The estimated Odds Ratios were 25.9 (95% CI: 1.6, 411) for ST-1 (entisols as soil
type) and 3.5 (95% CI: 0.3, 45) for ST-2 (inceptisols as soil type).
PMID- 10665951
TI - Failure to identify non-bovine reservoirs of Mycobacterium bovis in a region with
a history of infected dairy-cattle herds.
AB - The State of Texas had the most (cumulative) tuberculous cattle herds of any
state in the United States during the decade ending in 1997. Of the cumulative 18
infected herds in Texas, 12 herds were concentrated in El Paso County (designated
the 'El Paso milkshed'). To identify whether non-bovine reservoirs were a source
of Mycobacterium bovis infection of cattle in this region, an investigation was
conducted on the premises of 14 dairy herds (12 tuberculous and 2 non-affected
herds) between May 1995 and June 1997. None of the 670 mammalian, avian and
environmental (soil, water and air) samples collected and cultured from the
premises of these herds was positive for the presence of M. bovis. None of the
119 human urine samples obtained from employees of these dairies was culture
positive for M. bovis. Of 124 dairy-farm workers with tuberculin skin-test
results, 48 showed positive test results. There was, however, no difference in
percentages of positive skin-test results between farms without, and farms
having, bovine tuberculosis within the last two years or longer. The percentage
of positive reactions did not increase with length of time employed at a dairy
with a history of confirmed tuberculosis. These findings suggest that non-bovine
reservoirs appear not to be a factor responsible for tuberculosis of cattle in
the El Paso milkshed.
PMID- 10665952
TI - Effect of ethidium bromide intercalation on DNA radiosensitivity.
AB - PURPOSE: To assess the influence of the intercalating drug ethidium bromide
(EtBr) on the yields of single strand breaks (ssb) induced by fast neutrons in
supercoiled pBR322 plasmid and in a linear DNA restriction fragment. MATERIALS
AND METHODS: The yield of ssb in the plasmid was measured by agarose gel
electrophoresis. The proportion of fragments bearing one ssb and the probability
of breakage at each nucleotide site was determined using sequencing gel
electrophoresis. The volume variations due to the intercalation of EtBr were
calculated. The expected radio-modifying effect at each nucleotide site of the
linear fragment was evaluated using a reported simulation procedure. RESULTS: The
ssb yield in the plasmid increased for concentrations up to 0.04 drug/bp and fell
back in the range 0.04-0.1 drug/bp. For the linear DNA, only a slight protective
effect was observed over the whole concentration range. The effect was almost the
same at all nucleotide sites. CONCLUSION: For the linear DNA fragment,
radioprotection was mainly due to scavenging of OH* radicals by the intercalated
drug. For the plasmid, the radio-modifying effect results mainly from the
variation of its effective volume, due to the modification of superhelicity.
PMID- 10665953
TI - Effects of low dose irradiation on TK6 and U937 cells: induction of p53 and its
role in cell-cycle delay and the adaptive response.
AB - PURPOSE: To investigate the effect of small doses of radiation on the cell-cycle
and related processes, and to determine the capacity of small doses of radiation
to induce an adaptive response. MATERIALS AND METHODS: TK6, a lymphoblast cell
line with wild-type p53, and U937, a monocytic leukaemia cell line with mutant,
inactive, p53 were exposed to gamma ray doses ranging from 0.1 Gy to 3 Gy. Cell
cycle distributions and cyclin B1 were assessed by flow cytometry, and p53 and
p21 protein levels were measured by Western blotting. Apoptosis was determined by
fluorescence microscopy after staining with Hoechst 33342, and by measurement of
the pre-G1 cell population by flow cytometry. Micronuclei were determined in
cytokinesis-blocked cells by fluorescence microscopy. RESULTS: In TK6 cells,
radiation exposure induced elevated p53 and p21 levels and delayed expression of
cyclin B1. No changes in these parameters were found in U937 cells. Although both
cell lines arrested in G2/M after larger doses of radiation, G2/M-arrest occurred
after 0.1 Gy and 0.3 Gy in TK6 cells only. An apoptotic adaptive response was
induced in both cell lines by a 0.1 Gy priming dose but an adaptive response with
respect to micronuclei was observed only in U937 cells. CONCLUSIONS: The
radiation adaptive response can occur in the absence of wild-type p53. A small
dose of radiation may not protect cells against both apoptosis and cytogenetic
damage caused by a subsequent larger dose of radiation.
PMID- 10665954
TI - Production of chromatid breaks by single dsb: evidence supporting the signal
model.
AB - PURPOSE: The signal model proposes that all chromatid breaks arise from a single
DNA double strand break (dsb) via a recombinational exchange mechanism. Here the
prediction that chromatid breaks arise from a single dsb is tested. METHOD: The
genetically engineered Chinese hamster cell line GS19-43 containing a unique
yeast I-SceI recognition site was treated with I-SceI endonuclease (Meganuclease)
in the presence of the porating agent streptolysin O. Chromatid breaks were
scored at 4h, chromosome breaks at 18 and 22h following treatment (cells used for
a 4h fixation were prelabelled with BrdU over two cell-cycles). Positive controls
were treated with the restriction endonuclease Pst 1. RESULTS: I-SceI
endonuclease produced chromatid breaks and at higher enzyme concentrations
isochromatid breaks but no chromatid interchanges. About 16% of the chromatid
breaks had a 'colour-switch' between the sister-chromatids at the site of
breakage, as revealed by FPG staining. At the longer fixation times (18 and 22 h)
chromosome breaks were observed, but again no interchanges were seen. Chromatid
and chromosome breaks always appeared on the same chromosome. CONCLUSIONS: The
production of chromatid breaks from a single dsb fulfils the prediction of the
signal model. Moreover, the production of colour-switch breaks at a similar
frequency to that for ionizing radiation indicates that chromatid breaks are
produced via recombinational exchanges, a significant proportion of which occurs
between sister chromatids. The majority is intrachromatid, not involving strand
switches. The absence of interchromosomal exchanges at all fixation times
indicates a requirement of two dsb in two different chromosomes for their
formation.
PMID- 10665955
TI - Complex chromosome aberrations in peripheral blood lymphocytes as a potential
biomarker of exposure to high-LET alpha-particles.
AB - PURPOSE: To determine the induction and transmission, to second and third
division cells, of complex chromosome aberrations in peripheral blood lymphocytes
after exposure to high-LET alpha-particles in vitro. MATERIALS AND METHODS:
Separated peripheral blood lymphocytes collected from four healthy donors were
irradiated in vitro with either high-LET alpha-particles (121 keV/microm; 0.5 Gy)
or low-LET X-rays (250kV constant potential; 3 Gy). Cells were harvested in
first, second and third division post-irradiation and chromosome aberrations
observed at each cell division were analysed by combining the techniques of FISH
and DAPI/Hoechst 33258 harlequin staining. Whole chromosome probes were used for
chromosomes 1, 2 and 5, together with a pan-centromeric probe and the resulting
chromosome 'painting' patterns were classified according to the Savage and
Simpson (S & S) scheme (Savage and Simpson 1994a, Savage and Tucker 1996).
RESULTS: A greater proportion of complex chromosome aberrations was observed,
defined as involving three or more breaks in two or more chromosomes, relative to
total exchanges, after exposure to 0.5 Gy alpha-particles (mean 1 track/cell)
than after the high reference dose of 3 Gy X-rays (49-56% and 20-22%,
respectively). Qualitatively, alpha-particles induced chromosome aberrations of
far greater complexity than those observed after X-rays. This was reflected by
both the rapid reduction in the percentage of damaged cells between first and
second division indicative of cell death, and the spectrum of aberration types
observed in second and third division cells post-irradiation. Regardless of this
complexity, 15% of the complexes induced by alpha-particles at first division
were potentially transmissible and by third division, transmissible-type
complexes, specifically insertions, represented the predominant complex type
(65%). CONCLUSION: Transmissible-type complexes were observed, specifically
insertions, in both second and third division cells after exposure to high-LET
alpha-particles (0.5 Gy) in vitro. The authors predict these cells to be stable
and to be capable of persisting through many cell generations. Considering that
the induction of complex chromosome aberrations by low-LET radiation is strongly
dependent on dose, so that they are expected to be undetectable at environmental
exposures, insertions are much more likely to be a characteristic feature of high
LET radiation at all doses. From this the usefulness of insertions as biomarkers
of past exposure to environmentally relevant doses of high-LET alpha-particles is
supported.
PMID- 10665956
TI - Histone-like protein HU is required for recA gene-dependent DNA repair and SOS
induction pathways in UV-irradiated Escherichia coli.
AB - PURPOSE: Escherichia coli HU protein exists as a heterodimer composed of two
highly homologous subunits, HU-1 and HU-2, encoded by the hupB and hupA genes,
respectively. It introduces negative supercoils into a relaxed circular DNA.
Various roles of HU have been suggested in cellular processes such as DNA
replication and transcription. The present experiments were designed to
understand the role of HU in DNA repair processes in E. coli. MATERIALS AND
METHODS: The sensitivity of hupA/hupB mutants of E. coli to the lethal and
mutagenic effects of UV was compared with that of a wild-type strain. The effect
of the hupAhupB mutations in SOS induction was also examined. RESULTS: The
hupAhupB mutations increased the UV sensitivity of E. coli. Nucleotide excision
repair was unaffected by the deficiency of HU. On the other hand, E. coli
hupAhupB mutants were sensitive to UV in the recA+recB+recF background but not in
the recArecB+recF+ or recA+recBrecF+ background. The frequency of UV-induced
mutation to rifampicin resistance was significantly reduced in the hupAhupB
mutants, and the induction of the recA::lacZ and umuC::lacZ fusion genes was also
suppressed in the mutants. CONCLUSIONS: HU protein plays a critical role in the
recA, recB-dependent recombinational DNA repair and SOS induction pathways in UV
irradiated E. coli.
PMID- 10665957
TI - Effects of radical scavengers on radiation-induced DNA double strand breaks.
AB - PURPOSE: To investigate possible effects of Tris and phenol on the dynamic
properties of gamma-irradiated DNA molecules in addition to their well known
scavenging capacity. MATERIALS AND METHODS: Native and fragmented calf thymus DNA
molecules were exposed to various doses of 60Co gamma-rays at approximately
4.5Gy/min. Using thermal transition spectrophotometry, pulsed field gel
electrophoresis and standard agarose gel electrophoresis, the effects of Tris,
phenol and NaCl on the double helix to single coil thermal transition
temperature, Tm, and the yield of the double-strand breaks (Gdsb) of the
irradiated DNA molecules have been studied. RESULTS: DNA molecules exposed to
gamma-rays showed a decreased Tm and a corresponding increase of the Gdsb yield.
Tris, as well as phenol, exhibited a strong protection against preventing these
radiation-induced alterations. In addition, both substances strongly affected the
thermal stability of the non-irradiated DNA samples. These results, compared with
data obtained by NaCl and its effects on DNA thermostability and Gdsb, revealed
that in the presence of both scavengers the observed dsb decrease was correlated
to an increased molecular stability of DNA. CONCLUSIONS: This work suggests that
the total protective effect of Tris and phenol against radiation-induced dsb is
mainly attributed to their well-known radical scavenging properties, while
relatively minor protective effects arise from their contribution to an increased
molecular stability of DNA.
PMID- 10665958
TI - Technical report: SYBR Green I and the improved sensitivity of the single-cell
electrophoresis assay.
AB - The single-cell electrophoresis (comet) assay is an established method for
measuring radiation-induced strand breaks in DNA. The extent of damage is
quantified in individual cells by assessing the intensity and distribution of a
fluorescent DNA-binding dye using image analysis software. Using the Kinetic
Imaging Komet3 system, it is demonstrated that the fluorochrome SYBR Green I
improves the resolution and sensitivity of the comet assay, particularly for
measuring radiation-induced double strand breaks.
PMID- 10665959
TI - Comparison of biological effects of DNA damage induced by ionizing radiation and
hydrogen peroxide in CHO cells.
AB - PURPOSE: Free OH radicals are considered to be the common mediator of DNA damage
after ionizing radiation and oxidative stress. In particular, double-strand
breaks (dsb) have a major impact on cell killing after irradiation, while the
mechanism of cell killing is less clear for oxidative injury. The latter not only
affects DNA, but also equally other cell compartments, such as membranes and
mitochondria, which may trigger cell death. This study intended to clarify the
relationship between DNA damage induction, repair and cell inactivation for
hydrogen peroxide and ionizing radiation. MATERIALS AND METHODS: Chinese hamster
ovary (CHO) cells were treated with H2O2 in serum-free medium in combination
with/ without X-irradiation. DNA damage was measured using the alkaline unwinding
method or neutral constant-field gel electrophoresis. Cell survival was recorded
using the colony-formation assay. RESULTS: Hydrogen peroxide induced a large
number of single-strand breaks (ssb>36000/cell) without impairing cell survival.
This number reached a maximum (36 Gy-equiv. at 3 x 10(-4) mol/dm3) without
further increase after higher concentrations. Repair kinetics of ssb were similar
to those after irradiation. Dsb were found only after very high concentrations of
H2O2 (>3 x 10(-2) mol/dm3), which is different from irradiation which generated
ssb and dsb in the same dose range. A linear-quadratic increase of dsb was found
with increasing concentrations of H2O2 suggesting a single or a pairwise action
of OH radicals to form a dsb. After either irradiation or peroxide treatment cell
killing was observed only after doses which also allowed dsb detection. The
number of dsb calculated per lethal event was in the same range but slightly
higher after irradiation (1.7-fold) than after H2O2 treatment. CONCLUSIONS: Cell
killing after irradiation or hydrogen peroxide appears to be due to dsb, whereas
cells withstand large numbers of single-strand lesions and other types of non-DNA
damage occurring at lower concentrations of hydrogen peroxide. The number of ssb
saturates at intermediate concentrations of H2O2 suggesting that a limited amount
of chromatin-bound metal ions is available for OH radical generation.
PMID- 10665960
TI - Modification of murine adult haemopoiesis and response to methyl nitrosourea
following exposure to radiation at different developmental stages.
AB - PURPOSE: To investigate the hypothesis that the developmental phase at which an
individual encounters radiation damage affects its long-term sensitivity to a
subsequent tumourigenic insult. MATERIALS AND METHODS: Either the pregnant C57B16
mouse was exposed to 137Cs gamma-rays at 4 or 15 days post-conception (embryonic
and foetal stages respectively) or BDF1 offspring were irradiated at 4 or 21 days
of age (neonatal and juvenile stages). Offspring were either assayed for changes
in bone marrow stem cells and committed progenitors at 6, 12 and 18 weeks of age,
or injected with the chemical carcinogen methyl nitrosourea (MNU) at 10 weeks of
age and monitored for onset of neoplasia. RESULTS: Gamma-irradiation induced a
persistent long-term deficit in stem cells in all irradiated animals, with the
foetal stage appearing most radiosensitive. However, femoral cellularity,
committed progenitor cell numbers and peripheral blood counts were unaffected.
When offspring were exposed to MNU, the incidence of malignancy was significantly
enhanced in animals irradiated at the foetal, neonatal and juvenile stages.
CONCLUSIONS: This study has shown that exposure to ionizing radiation at the
foetal, neonate or juvenile stages of development induces residual haemopoietic
damage and increases oncogenic susceptibility to a subsequent exposure to MNU.
PMID- 10665961
TI - Transformation by radiation of rat foetal glial cells.
AB - PURPOSE: To establish and characterize an in vitro model of radiation-induced
transformation of normal glial cells. MATERIALS AND METHODS: During the last week
of gestation, pregnant Sprague-Dawley rats were either irradiated at 3.5 Gy
(0.022 Gy h(-1)) with a 60Co source or sham irradiated. On day 21 of gestation,
cortical nerve cells from foetuses were isolated, and then maintained in culture
for about 100 passages, in presence of 10(-9) g/ml of tetradecanoyl phorbol
acetate (TPA). To follow transformation, various parameters: cell type,
proliferation, clonogenicity, karyotypes and tumorigenicity, were studied at
different passages. RESULTS: As the number of passages increased, control cells
lost their glial morphology and were immortalized. They kept on expressing
specific markers of type 2 astrocytes (glial fibrillary acid protein (GFAP) and
A2B5). Karyotypes remained near diploid. At all passages tested, they were not
tumorigenic in nude mice. Irradiated cells expressed the 2A progenitor cell
specific markers: GFAP, vimentin and A2B5. Karyotypes evolved toward polyploidy
and cells displayed an iso 7 and a marker. These changes were synchronous with
modifications in tumorigenicity. Metastases were even observed in nude mice.
CONCLUSIONS: Cells from irradiated animals were fully transformed, while cells
from sham irradiated animals were only immortalized.
PMID- 10665962
TI - Induction of solid tumours in the Swiss albino mouse by low-dose foetal
irradiation.
AB - PURPOSE: To study the tumourigenic effect of prenatal low-dose gamma-irradiation
in the mouse. METHODS AND MATERIALS: Pregnant Swiss albino mice were exposed to
0.1-1.5 Gy gamma-radiation on days 14 or 17 of gestation. The F1 offspring were
observed up to 18 months of age. All the mice were killed at 18 months and the
incidence of tumours in different organs was recorded. RESULTS: Exposure to doses
from 0.1 to 1.5 Gy on days 14 or 17 of gestation produced a linear-quadratic dose
dependent increase in tumour incidence in adult F1 mice. The main organs affected
were the ovary, uterus, liver and spleen. The highest incidence was observed in
the ovaries, which was significantly higher than spontaneous incidence, even at
0.25 Gy. In other organs the tumour incidence was not significant compared with
controls at doses < 0.5-1.0 Gy. Tumours in the ovary and uterus developed at an
earlier age than in the liver and spleen. CONCLUSIONS: Exposure to gamma
radiation < 1.0 Gy at the foetal period (days 14 or 17 of gestation) can cause
induction of tumours in the Swiss albino mouse. The carcinogenic effect,
particularly on the ovary among the female mouse, is detectable after low-dose
foetal irradiation.
PMID- 10665963
TI - Microdistribution and localized dosimetry of the alpha-emitting radionuclides
239Pu, 241Am and 233U in mouse femoral shaft.
AB - PURPOSE: To analyse the temporal change in microdistribution of 239Pu, 241Am and
233U in mouse femur and to compare the calculated radiation doses with regions of
the bone marrow thought to contain target cells for osteosarcoma and leukaemia
with relative risk for those diseases. MATERIALS AND METHODS: Neutron-induced and
alpha-track autoradiographs were prepared from femora of the CBA/H mouse that had
been injected with 40 kBq kg(-1) radionuclide between 1 and 448 days previously.
Computer-based image analysis of the autoradiographs was performed and dosimetric
methods applied to obtain radiation dose-rates to different regions of the marrow
cavity. RESULTS: Initially each radionuclide deposited on endosteal and
periosteal bone surfaces; 241Am was additionally deposited on vascular canal
surfaces. Redistribution resulted in 233U being incorporated into bone, while
239Pu and 241Am showed transfer into both bone volume and marrow. Accumulation in
the central marrow peaked at 112-224 days post-injection, but subsequently was
cleared by 448 days. Cumulative doses to both osteosarcomagenic and myeloid
leukaemogenic target cell regions showed the trend 239Pu > 241Am > 233U.
CONCLUSIONS: Calculation of cumulative doses to a 10-microm layer of marrow
adjacent to bone surfaces appears to be a suitable predictor for risk of
osteosarcoma. Risks of myeloid leukaemia in the mouse are better predicted by
considering the central marrow as the target region rather than average dose to
all marrow.
PMID- 10665964
TI - Efficacy of 3,4,3-LIHOPO for reducing neptunium retention in the rat after
simulated wound contamination.
AB - PURPOSE: The ligand 3,4,3-Li(1,2-HOPO) was tested for Np removal after
intramuscular injection of 237Np nitrate in rats. MATERIALS AND METHODS: Two
experiments were performed, one with simultaneous injection of neptunium and
LIHOPO at dosages ranging from 3 to 200 micromol kg(-1) and the other with
delayed administration of LIHOPO 30 micromol kg(-1) from 5 min to 30 min after Np
injection. RESULTS: The data obtained after simultaneous injections showed that
the ligand dosage effectiveness was not linear and depended on the tissues being
considered. For bones, the best results were obtained with 200 micromol kg(-1)
LIHOPO, where retention was reduced to 11% of controls. Maximum efficacies for
removal in liver and kidney were obtained with 30 micromol kg(-1) LIHOPO, where
retention was reduced to 39% and 1.6% of controls, respectively. At higher
dosages, LIHOPO seemed to have a reverse effect on these tissues, demonstrated by
a significant accumulation of the radionuclide. The delayed administration of
LIHOPO dramatically decreased its efficacy. When administered 5 min after Np,
LIHOPO was still efficient (60%, 37%, 7% of controls in bone, liver, kidneys,
respectively) but not when treatment was delayed to 30 min. CONCLUSIONS: These
results demonstrated that LIHOPO was able to complex Np at the wound site but not
after translocation to blood.
PMID- 10665965
TI - Commentary on the Second Event Theory of Busby.
PMID- 10665966
TI - Commentary on the Second Event Theory of Busby by A. A. Edwards and R. Cox.
PMID- 10665967
TI - Think metabolically.
PMID- 10665968
TI - Persisting motor control problems in 11- to 12-year-old boys previously diagnosed
with deficits in attention, motor control and perception (DAMP).
AB - The aim of this study was to examine whether boys who had been previously
diagnosed between the ages of 5 and 8 years with deficits in attention, motor
control and perception (DAMP) still have problems with motor control, which
influence their spare-time and everyday activities, at 11 to 12 years. The study
comprised a well defined cohort of 10 boys with DAMP and a control group of 20
boys without DAMP matched for age, height, and weight. The Movement Assessment
Battery for Children was used to assess motor control in ability to perform
everyday activities, and the spare-time activities in which the boys participated
were recorded. Individually, the boys previously diagnosed with DAMP had a
markedly higher total score (poor performance) than the boys without DAMP
(P<0.001). The everyday activities of boys with DAMP were significantly affected,
and they chose to participate in different sports from the control boys, i.e.
none participated in team sports. The present study does not support the concept
of improvements in motor control with age in children with DAMP.
PMID- 10665969
TI - Corpus callosum may be similar in children with ADHD and siblings of children
with ADHD.
AB - No previous studies have used morphological neuroimaging to compare children with
ADHD with siblings of children with ADHD. To test the hypothesis that the total
size of the corpus callosum is altered in children with hyperkinetic disorder,
the corpus callosum was outlined from a single midline protondensity weighted
slice (containing the septum pellucidum). Fifteen boys with a refined phenotype
of ADHD (mean age 10.2 years) and 15 healthy male siblings of children with ADHD
(mean age 10.6 years) were enrolled in the study. The two groups were compared
for global brain size and the callosal areas of Witelson. No significant
differences were found between the study and comparison groups for any of the
corpus callosum areas, even after age, global brain size, and handedness were
covaried (using MANOVA). In addition, corpus callosum sizes do not seem to differ
between children with ADHD and unaffected siblings of children with ADHD.
Clinicians should not base their pathophysiological diagnosis of this disorder on
an abnormality of callosal development.
PMID- 10665970
TI - Fetal growth and subsequent mental health problems in children aged 4 to 13
years.
AB - To test the hypothesis that children with suboptimal fetal growth have
significantly poorer mental health outcomes than those with optimal growth, a
population random sample survey of children aged 4 to 16 years in Western
Australia in 1993 was conducted. The Child Behavior Checklist (Achenbach 1991a)
and the Teacher Report Form (Achenbach 1991b) were used to define mental health
morbidity. Survey data for 1775 children aged 4 to 13 years were available for
linkage with original birth information. The percentage of expected birthweight
(PEBW) was used as the measure of fetal growth. Children below the 2nd centile of
PEBW who had achieved only 57% to 72% of their expected birthweight given their
gestation at delivery were at significant risk of a mental health morbidity (OR
2.9, 95% CI 1.18, 7.12). In addition, they were more likely to be rated as
academically impaired (OR 6.0, 95% CI 2.25, 16.06) and to have poor general
health (OR 5.1, 95% CI 1.69, 15.52).
PMID- 10665971
TI - Parental and professional agreement in developmental assessment of very-low
birthweight and term infants.
AB - The aim of this prospective follow-up study was to evaluate the accuracy of a
parent-completed questionnaire compared with professionally detected
developmental delay. Parents of 108 very-low-birthweight (VLBW) infants and
parents of 279 term control infants completed the German version of the Revised
Prescreening Developmental Questionnaire (R-PDQ) at the corrected age of 12
months. Simultaneously, infants underwent developmental examination using the
Griffiths Developmental Scale. Sixty-nine VLBW infants were classified as not
delayed, 16 as delayed by both methods (conegativity 76% and copositivity 94%),
as compared to 240 and six term control infants (conegativity 88%, copositivity
94%). The questionnaire suggested delay in 22 VLBW infants and 32 control
infants, which was not substantiated by professional examination (P=0.006). In
contrast, examination-diagnosed delay was missed by the questionnaire in one
infant in each group. The R-PDQ is a reliable monitoring instrument for both VLBW
and term infants at the age of 12 months. Parents of VLBW infants tend to
underestimate their infants' development.
PMID- 10665972
TI - Predictive utility of the Bayley Infant Neurodevelopmental Screener (BINS) risk
status classifications: clinical interpretation and application.
AB - Predictive validity and clinical implications of the increasingly popular Bayley
Infant Neurodevelopmental Screener (BINS) risk status classifications have not
been previously reported. In this longitudinal follow-up study, the BINS was
administered to high-risk infants at 6, 12, and 24 months of age, and the
McCarthy Scales at 3 years of age. Ninety-two children were evaluated at 6 and 36
months, 105 at 12 and 36 months, and 118 at 24 and 36 months; 190, 125, and 140
infants were included in the comparisons at 6 to 12, 6 to 24, and 12 to 24
months. BINS risk status was classified as low, moderate, or high; or as a binary
variable, LOWRISK/HIGHRISK. The three BINS items groups were moderately
correlated. Consistency was most variable in the moderate-risk group. BINS risk
was predictive of 36-month function in 18 out of 18 comparisons. Odds ratios,
ranging from 2.76 to 54.70, were significant in 15 out of 18 logistic models. An
early high-risk classification was associated with increased probability of later
developmental morbidity. The BINS offers an alternative to detailed assessment in
high-volume clinical applications and has good concurrent and predictive
validity.
PMID- 10665973
TI - Biomechanical transformation of the gastroc-soleus muscle with botulinum toxin A
in children with cerebral palsy.
AB - Objective measures (kinematics and kinetics) were used to study prospectively the
effects of botulinum toxin A (BTX/A) on the gastro-soleus muscle in ambulant
children with cerebral palsy. In this prospective before and after trial, 15
children with diplegia and 10 children with hemiplegia were studied (mean age 5
years 7 months, range 4 years to 9 years). A range of standardized clinical
measures was undertaken but the emphasis for this report is on the three
dimensional gait analysis (3DGA) results. All children showed improvements in
sagittal ankle kinematics, as has been previously reported. Two new measures of
ankle kinetics were devised: ankle moment quotient (AMQ), and ankle power
quotient (APQ). Before intervention, ankle moments were characterized by a
'double bump' ankle moment. A typical abnormal baseline ankle-power curve was
triphasic with an initial trough of absorption followed by abnormal mid-stance
power generation, instead of the usual A1 pattern, and reduced terminal stance
power generation (A2). Three weeks after treatment with BTX/A alone there was a
statistically significant improvement of AMQ and APQ; some patients required
potentiation of BTX/A with a short period of serial casts. Both groups (BTX/A
alone and BTX/A plus casting) continued to show improvement in ankle kinetics
from baseline after 12 and 24 weeks. This is the first study to demonstrate
improvements in the typical abnormal ankle kinetics which we believe provides
evidence of the 'biomechanical transformation of muscle'.
PMID- 10665974
TI - Ankle spasticity and strength in children with spastic diplegic cerebral palsy.
AB - Ankle spasticity and strength in 27 children with spastic diplegic cerebral palsy
(CP) (mean age 9 years, range 3 to 18 years) and a group of 12 children without
CP (comparison group) (mean age 9 years, range 5 to 18 years) were observed. To
measure spasticity, a KinCom dynamometer dorsiflexed the passive ankle at five
different speeds and recorded the resistive plantarflexion torques. Work values
for the torque-angle data were calculated at each speed. Using this data, linear
regression was used to measure spasticity. To measure strength, the dynamometer
rotated the ankle from maximum dorsiflexion to maximum plantarflexion at a speed
of 10 degrees/s while the child performed a maximum plantarflexion concentric
contraction. The movement was reversed to record maximum dorsiflexion. Maximum
torques and work by the plantarflexors and dorsiflexors were calculated. The
group with CP had significantly more spasticity in the plantarflexors and
significantly less strength in the plantarflexors and dorsiflexors than the group
without CP. Results provide objective information quantifying ankle spasticity
and strength in children with CP.
PMID- 10665975
TI - A study of EEG, electroretinogram, visual evoked potential, and eye movements in
classical lissencephaly.
AB - EEG, flash electroretinogram (ERG), and visual evoked potential (VEP) findings
are described in eight children with classical lissencephaly (six girls, two
boys), with a mean age of 17.6 months (range 2 to 60 months). The EEG shows
typically high-voltage activity. Eye movements were formally recorded in two
patients, and both showed features associated with oculomotor apraxia. The ERG
and VEP to flash stimulation were normal in all cases. Two subjects had pattern
reversal stimulation, and their pattern VEPs were within normal limits. Some
patients with lissencephaly may appear to have delayed visual maturation on first
presentation, and EEG and eye movement studies are valuable in indicating
neurological deficiency at an early stage in these subjects.
PMID- 10665976
TI - Severe bronchopulmonary dysplasia increases risk for later neurological and motor
sequelae in preterm survivors.
AB - Preterm children who develop severe chronic lung disease may be developmentally
compromised by exposure to hypoxic episodes. This study aims to determine if
children with severe bronchopulmonary dysplasia (BPD) who required home oxygen
therapy were at greater risk for neurological and motor deficits at school age
than preterm peers without BPD. This study evaluated 27 subjects with BPD and 27
preterm control infants matched for gestational age, birthweight, sex, and year
of birth at a mean age of 9.9 years (2.0 SD) using standardized neuromotor
outcome measures. Pair-matched comparisons and regression analyses were used to
determine if subjects with BPD were at increased risk for neuromotor sequelae.
Neurological abnormalities, including subtle neurological signs, cerebral palsy,
microcephaly, and behavioral difficulties were highly prevalent in the BPD group
(71% compared with 19% in control group, P<0.005). Over half the BPD cohort had
difficulties in gross and/or fine motor skills. There were significant
differences in postural stability between groups. Duration of hospitalization and
home oxygen treatment, and decreased lung function at school age, markers of
severity of illness, correlated with motor outcomes. The findings underline the
importance of preventing the cardiorespiratory complications associated with
chronic lung disease to minimize disability in preterm children. For children
with severe BPD, better recognition and subsequent remediation of neuromotor
impairments that manifest at school age may help maximize their functional
potential.
PMID- 10665977
TI - New ocular movement detector system as a communication tool in ventilator
assisted Werdnig-Hoffmann disease.
AB - A non-contact communication system was developed for a ventilator-assisted
patient with Werdnig-Hoffmann disease who had lost all voluntary movements except
for those of the eye. The system detects the extraocular movements and converts
them to either a 'yes' signal (produced by one lateral eyeball movement) or a
'no' signal (produced by two successive lateral eyeball movements) using a video
camera placed outside the patient's visual field. The patient is thus able to
concentrate on performing a task without any intrusion from the detection system.
Once the setting conditions of the device have been selected, there is no need
for any resetting, as the patient is unable to move his body. In addition to
playing television games, the child can use the device to select television
channels, compose music, and learn written Japanese and Chinese characters. This
seems to broaden the patient's daily world and promote mental development.
PMID- 10665978
TI - Posture and motility in preterm infants.
PMID- 10665979
TI - Linking motor impairment to function.
PMID- 10665980
TI - Current status of artemisinin and its derivatives as antimalarial drugs.
AB - Artemisinin is a promising and a potent antimalarial drug, which meets the dual
challenge posed by drug-resistant parasites and rapid progression of malarial
illness. This review article focuses on the progress achieved during the last
years in the production of artemisinin from Artemisia annua. The structure,
biosynthesis and analysis of artemisinin and its mode of action are described.
The review also focuses on clinical studies, toxicity studies, pharmacokinetics
and activity of artemisinin related compounds. The production strategies
including organic synthesis, extraction from plants, in vitro cultures and
alternative strategies for enhancing the yields are also discussed.
PMID- 10665981
TI - Inhibition of inducible nitric oxide synthase in persistent pain.
AB - The present study was undertaken to investigate the role of inducible nitric
oxide synthase in a rat model of persistent pain. The effects of L-N6 (1
iminoethyl) lysine (L-NIL), a relatively potent and relatively selective
inhibitor of inducible nitric oxide synthase, were investigated in carrageenan
induced hyperalgesia L-NIL (0.1 microMole) injected intraplantar or intrathecal
markedly enhanced carrageenan induced hyperalgesia. These effects were reversed
during the third hour by co-administration of L-arginine (900 mg/kg i.p.) but not
D-arginine. Methylene blue (MB), a soluble guanylate cyclase inhibitor,
administered intrathecally (0.1 microg) had no effect on L-NIL potentiation of
carrageenan hyperalgesia but abolished antinociception induced by L-arginine.
Obtained results suggest that nitric oxide derived from inducible nitric oxide
synthase play an inhibitory role in carrageenan produced hyperalgesia in rat.
PMID- 10665982
TI - Enhanced pial arteriolar sensitivity to bioactive agents following exposure to
endothelin-1.
AB - Effects of prior exposure of pial arterioles to endothelin-1 (ET-1) (10(-9) M) on
the constriction induced by the by-products of hemolyzed blood (5-HT, LTC4, LPA,
and thromboxane analog U-46619) were examined. Piglets (age: 1-3 d) anesthetized
with a mixture of ketamine hydrochloride and acepromazine were implanted with
cranial windows, and anesthesia was maintained with alpha-chloralose. Topical
applications of the by-products of hemolyzed blood mildly constricted pial
arterioles. Following prior exposure of the microvessels to ET-1, application of
the by-products of hemolyzed blood produced significantly potentiated and long
lasting constrictions compared to the controls. In another experiment,
pretreatment of pial arterioles with U-46619 (10(-8) M) also potentiated the
constriction induced by ET-1. The constriction produced was fast and longer
lasting. Thus, these data show that by-products of hemolyzed blood, though not
potent vasoconstrictors per se, potently constricted pial arterioles in the
presence of ET-1. The same agents in the CSF can also potentiate constriction
induced by ET-1. Hence, by-products of hemolyzed blood may play a significant
role in the initiation and maintenance of cerebral arterial narrowing observed
following intracranial bleeding.
PMID- 10665983
TI - Prolonged exposure to cigarette smoke blocks the neurotoxicity induced by kainic
acid in rats.
AB - We examined the effects of cigarette smoke (CS) on three parameters associated
with kainic acid (KA)-induced neurotoxicity: seizure activity, cell loss in the
hippocampus, and increased Fos-related antigen (FRA) expression. Animals were
exposed to the main stream of CS from 15 Kentucky 2R1F research cigarettes
containing 28.6 mg tar and 1.74 mg nicotine per cigarette, for 10 min a day, 6
days per week, for 4 weeks, using an automatic smoking machine. KA administration
(10 mg/kg, i.p.) produced robust behavioral convulsions lasting 4-5 h. Pre
exposure to CS significantly reduced the seizures, mortality, and severe loss of
cells in regions CA1 and CA3 of the hippocampus after KA administration.
Consistently, pre-exposure to CS significantly attenuated the KA-induced
increased FRA immunoreactivity in the hippocampus. In contrast, pretreatment with
central nicotinic antagonist, mecamylamine (2 or 10 mg/kg, i.p.) blocked the
neuroprotective effects mediated by CS in a dose-dependent manner. These results
indicate that CS exposure provides neuroprotection against the KA insult via
nicotinic receptor activation.
PMID- 10665984
TI - Mechanical characterization of regenerated osseous tissue during callotasis and
its related biological phenomenon.
AB - The mechanical characteristics of the regenerated osseous tissue and osteoblastic
activities during callotasis were studied using Chinese mountain goat as the
animal model. Open osteotomy of the left tibiae was done in 24 goats. Distraction
started 6 days after the operation with the rate of 1 mm per day for 4 weeks. The
bone regeneration was monitored with serial X-ray films. The tension generated
during distraction was measured with the strain gauges mounted on the distraction
apparatus. The osteoblastic activities were monitored by measuring plasma bone
specific alkaline phosphatase activity. The results showed that the average
lengthening was 22.9 +/- 2.8 mm in each animal. The newly formed osseous tissue
becomes stiffer during the course of distraction lengthening. The continuous
evolution of the tensile behaviour of the newly formed osseous tissue correlates
with the plasma bone specific alkaline phosphatase activities. The radiological
appearance of a physis like structure took place at 12 mm lengthening. Its
appearance corresponds to the changes in the tensile behaviour as well as the
biological activities of the osteoblasts and may serve as a useful radiological
marker in monitoring the process of callotasis in clinical practice.
PMID- 10665985
TI - Diabetes alters neuronal nitric oxide release from rat mesenteric arteries. Role
of protein kinase C.
AB - The objective of the present study was to assess the influence of diabetes in the
neuronal nitric oxide (NO) release elicited by electrical field stimulation (EFS,
200 mA, 0.3 ms, 1-16 Hz, for 30 s, at 1 min interval) in endothelium-denuded
mesenteric artery segments from control and streptozotocin-induced diabetic rats,
assessing the influence of protein kinase C (PKC) in this release. N(G)-nitro-L
arginine-methyl ester (L-NAME, 10 microM, a NO synthase inhibitor) enhanced EFS
elicited contractions in control, and specially in diabetic rats, whereas they
were unaltered by AMT (5 nM, an inducible NO synthase inhibitor) and capsaicin
(0.5 microM, a sensory neurone toxin). Calphostin C (0.1 microM, a PKC inhibitor)
increased the contraction elicited by EFS in both types of arteries. This
increase was further enhanced by calphostin C + L-NAME in diabetic rats. Phorbol
12,13-dibutyrate (PDBu, 1 microM) reduced and unaltered EFS-induced contractions
in control and diabetic rats, respectively. The further addition of L-NAME
reversed the reduction obtained in control rats, and enhanced the response
observed in diabetic rats. These results suggest that the EFS-induced NO release
from perivascular nitrergic nerves, that negatively modulates the contraction,
which is synthesized by neuronal constitutive NO synthase. The NO synthesis is
positively stimulated by PKC. This NO release is increased in diabetes, likely
due to an increase in the activity of this enzyme. The sensory nerves of these
arteries do not seem to be involved in the contractile response.
PMID- 10665986
TI - Effects of euxanthone on neuronal differentiation.
AB - The growth inhibitory and differentiation inducing effects of euxanthone (1,7
dihydroxyxanthone) from the medicinal plant Polygala caudata on the neuroblastoma
(Neural 2A, subclone BU-1) were investigated. At the concentration range of 0-100
microM, euxanthone inhibits the growth of BU-1 cells in a dose dependent manner.
The 50% growth inhibitory concentration (IC50) was 41 microM. Significant
induction of morphological differentiation and neurite growth was observed at the
concentration of 100 microM. Frequency of proliferative neuroblastoma cells was
determined after induction of differentiation. The frequency of proliferating BU
1 cells was markedly reduced from 1/1.1 to <1/99. Confocal microscopy also
confirmed that the morphological differentiation of BU-1 was associated with the
expression of neurite specific marker MAP-2 protein in neurites. These data
suggest that euxanthone may be one of the neuropharmacological active compounds
in the medicinal plant Polygala caudata.
PMID- 10665987
TI - Kappa-opioid receptor stimulation increases the expression of Na+-H+ exchange
gene in the heart.
AB - Kappa-opioid receptor (OR) stimulation increases intracellular pH (pHi) via
activating the Na+-H+ exchange (NHE). In the present study, we determined the
expression of the gene of NHE1, the predominant NHE isoform in the heart, and
intracellular pH (pHi) upon kappa-OR stimulation in the rat heart. We found that
1 microM U50,488H (trans-3,4-dichloro-N-methyl-N-(2-(1
pyrrolidinyl)cyclohexyl)benzeneacetamide), a selective kappa-OR agonist,
increased the expression of the NHE1 gene. We also found that U50,488H dose
dependently increased pHi in the heart. The effects were abolished by 1 microM
nor-binaltorphimine (nor-BNI), a selective kappa-OR antagonist, indicating that
the events were kappa-OR mediated. The effects on both NHE1 gene expression and
pHi were also abolished by 5 microM chelerythrine and 5 microM BSM
(bisyndolylmaleimide), protein kinase C (PKC) inhibitors, indicating that PKC
mediated the actions. In addition, the effect of U50,488H on pHi was blocked by
10 microM EIPA (ethylisopropyl amiloride), a NHE1 inhibitor, indicating that NHE1
also mediated the action of U50,488H. The present study provides evidence for the
first time that kappa-OR stimulation increased the NHE1 gene expression in the
heart via a PKC dependent pathway. Kappa-OR stimulation also increases pHi via
PKC and NHE in the heart.
PMID- 10665988
TI - Enterohepatic circulation of chloramphenicol and its glucuronide in the rat by
microdialysis using a hepato-duodenal shunt.
AB - A system consisting of a hepato-duodenal shunt in which the bile of a drug
treated donor rat was diverted to the duodenum of an untreated recipient rat via
a bile cannula was used to assess the role of hepatic metabolism and
enterohepatic circulation in the pharmacokinetics of chloramphenicol. Blood
concentrations of unbound chloramphenicol and its glucuronide were measured by on
line microdialysis coupled to a microbore liquid chromatographic system. Results
indicated that chloramphenicol and its glucuronide were detected in the blood of
both donor and recipient rats following an intravenous 100 mg/kg dose of
chloramphenicol succinate to the donor rat. Our finding suggests that although
enterohepatic circulation contributed only to a minor extent (approximately 1.8%)
was involved in the disposition of unbound chloramphenicol in the rat on-line
microdialysis techniques were applicable for such studies.
PMID- 10665990
TI - Molluscicidal and piscicidal activities of Venezuelan Chrysobalanaceae plants.
AB - Extracts of increasing polarity of 6 Venezuelan plants belonging to the
Chrysobalanaceae family were tested for possible letal toxicity against
Biomphalaria glabrata Say, a snail intermediate hosts of Schistosoma mansoni
Sambon. The piscicidal toxicity of the active extracts was also evaluated with
the aim of findings compounds without toxicity in nontarget organisms,
principally fishes and humans.
PMID- 10665989
TI - Increased brain P-glycoprotein in morphine tolerant rats.
AB - The objective of this study was to determine whether chronic morphine exposure
increased P-glycoprotein in rat brain. Male Sprague-Dawley rats were treated with
morphine, saline, or dexamethasone for 5 days. On day 6, antinociceptive effect
was measured to evaluate the extent of functional tolerance to morphine. Brain P
glycoprotein was detected by Western blot analysis of whole brain homogenate.
Morphine- and dexamethasone-treated rats exhibited decreased antinociceptive
response when compared to saline-treated controls. Brain P-glycoprotein was
approximately 2-fold higher in morphine-treated rats compared to saline controls
based on Western blot analysis. Chronic morphine exposure appears to increase P
glycoprotein in rat brain. P-glycoprotein induction may enhance morphine efflux
from the brain, thus reducing morphine's pharmacologic activity. Induction of P
glycoprotein may be one mechanism involved in the development of morphine
tolerance.
PMID- 10665991
TI - Differential potentiative effects of GABA receptor agonists in the production of
antinociception induced by morphine and beta-endorphin administered intrathecally
in the mouse.
AB - The effect of muscimol or baclofen injected intrathecally (i.t.) on the
inhibition of the tail-flick response induced by morphine and beta-endorphin
administered i.t. was studied in ICR mice. The i.t. injection of muscimol (100
ng) or baclofen (10 ng) alone did not affect the basal inhibition of the tail
flick response. Morphine (0.2 microg) and beta-endorphin (0.1 microg) caused only
slight inhibition of the tail-flick response. Baclofen, but not muscimol,
injected i.t. enhanced the inhibition of the tail-flick response induced by i.t.
administered morphine. Both muscimol and baclofen injected i.t. significantly
enhanced i.t. injected beta-endorphin-induced inhibition of the tail-flick
response. Our results suggest that the GABA(B), but not GABA(A), receptors
located in the spinal cord appear to be involved in enhancing the inhibition of
the tail-flick response induced by morphine administered spinally. In addition,
both GABA(A) and GABA(B) receptors are involved in enhancing the inhibition of
the tail-flick response induced by beta-endorphin administered i.t.
PMID- 10665992
TI - Toxicity during early development of the mouse nervous system of a scorpion
neurotoxin active on sodium channels.
AB - The lethal effects of scorpion envenomation is due to neurotoxins active on
voltage-sensitive sodium channels. Dysfunctions of the peripheral and central
nervous systems with neurological manifestations are commonly observed after
scorpion stings, specially in young children. Since the neurotoxicity of venom
fraction is greatly higher by intracerebroventricular than by subcutaneous
injections, a direct effect of venom on CNS cannot be excluded specially in
infants where the blood-brain barrier is not fully functional. We investigated
the activity of a neurotoxin from the scorpion Androctonus australis hector
(AahII) in newborn mice at 3, 7 and 14 days after birth and in adults. Young mice
(P3, P7) were more sensitive to AahII injected subcutaneously than were adults,
but were less sensitive to intracerebroventricular injection. The affinity of
AahII for its receptor site on brain synaptosomes from P3 and P7 mice was
slightly higher and the density of the binding sites was half that of adult mice.
After subcutaneous injection of [125I]-AahII it was also observed that a small
amount of radioactivity was found in brains of neonate mice but not in that of
adults. This amount is however extremely lower than the value of the LD50
determined by intracerebroventricular injection. Results are consistent with a
peripheral action of AahII and show that its toxic activity changes during the
mouse nervous system development.
PMID- 10665993
TI - Response of high mobility group proteins of human kidney T1 and murine L 929 cell
lines to heat shock.
AB - High mobility group (HMG) proteins in human kidney T1 and murine L 929 cells have
been investigated after exposure to heat shock at 41 degrees C and their
influence on the organizational change of chromatin under heat shock condition
has been examined. Results reveal that the two cell lines show differential
response of the HMG proteins 1 & 2 and 14 & 17 to heat shock. Neither T1 nor L
929 cells show significant differences in response to heat shock with respect to
the binding affinities of HMG proteins 1 & 2 or 14 & 17 to DNA, as revealed by
DNase I sensitivity and chromatin reconstitution assays. Furthermore, the HMG
proteins of both the non-heat shocked and the heat shocked T1 and L 929 cells can
recover their chromatin activity following reconstitution. These findings suggest
that although the HMG proteins might undergo some change in response to heat
shock, their inherent potential of reassociation with DNA is still retained.
PMID- 10665994
TI - In vivo exposure to carbon disulfide increases the contraction frequency of
pregnant rat uteri through an indirect pathway.
AB - Exposure to CS2, an organic solvent, is associated with an increased rate of
abnormal labor or dysmenorrhea. Contraction of quiescent uteri during pregnancy
can cause preterm labor. We wish to know the effects of in vivo and in vitro
exposures to CS2 on uterine contractions of mid-gestation rats. After 10-d
exposure to 300 or 600 mg/kg CS2, uteri of pregnant rats were measured for
contractile responses to various stimuli, such as KCl, oxytocin, carbachol or
A23187, a calcium ionophore, using standard muscle bath apparatus. CS2 treatment
significantly increased the contractile response to KCl, carbachol, and A23187.
The increase to A23187 was the greatest. In contrast, in vitro exposure to CS2
immediately suppressed carbachol-induced contraction but did not affect
spontaneous and KCl-induced contractions. Results showed the pregnant uterus of
the rat is susceptible to CS2. The influence of in vivo exposure to CS2 on
uterine contraction was opposite to that in vitro. The increased response of CS2
treated uteri to A23187 suggests that in vivo exposure to CS2 may sensitize
contraction machinery to calcium through indirect pathways.
PMID- 10665995
TI - Circadian periodicity of urinary volume, creatinine and 5-hydroxyindole acetic
acid excretion in healthy Indians.
AB - The circadian periodicity of urinary output, creatinine (Cr) and 5-hydroxyindole
acetic acid (5-HIAA) excretion was studied under near-tropical conditions in 130
healthy volunteers (65 men and 65 women, 16-75 years of age) with a diurnal
activity from about 06:30 to about 22:00 and nocturnal rest. These volunteers
were divided into 4 groups, 16-30, 31-45, 46-60 and 61-75 years of age,
comprising 20, 20, 15 and 10 participants of each gender, respectively. A marked
circadian rhythm was recorded for urine volume, Cr and 5-HIAA excretion in
healthy Indians of different ages. The acrophase tended to be delayed in the
older age group. The relative amplitude decreased with advancing age, notably in
women. Overall, men produced a larger urine volume as compared to women.
Excretions of Cr and 5-HIAA in healthy Indian volunteers of different ages may be
influenced by diet, societal relations, climate and/or geographic location. The
contribution of such factors in metabolism and degradation warrants further
study.
PMID- 10665996
TI - Shear stress enhances prostacyclin release from endocardial endothelial cells.
AB - The effect of shear stress on the release of prostacyclin (PGI2) from cultured
endocardial endothelial cells (EECs) was investigated. EECs were harvested from
the right ventricle (RV) and the left ventricle (LV) of porcine heart. Confluent
EECs were incubated under various degrees of shear stress (0.2, 1, 4 and 6
dyne/cm2) and PGI2 release from each cell was measured. PGI2 release from LV-EECs
and RV-EECs was enhanced by the elevation of shear stress in a shear-dependent
manner with a rapid increase at the onset of flow; however, there was no
significant difference in PGI2 production between RV-EECs and LV-EECs. production
of PGI2 was significantly inhibited from cells exposed to 8-(dimetilamino) octyl
3,4,5-trymethoxybenzoate hydrochloride (10 and 100 microM: an inhibitor of
intracellular calcium mobilization) or cyclopiazonic acid (10 microM: an
endoplasmic reticulum Ca2+-ATPase inhibitor). These results indicate that shear
stress enhances PGI2 release from cultured EECs and that mechanotransduction of
shear stress depends on calcium mobilization in EECs.
PMID- 10665997
TI - Lack of interaction in recombinant human FSH receptor and both TSAb and TSBAb.
AB - Since cross-reactivity of TSH with the human FSH receptor has been reported, in
this study we tested the effect of thyroid-stimulating antibody (TSAb) and
thyroid stimulation-blocking antibody (TSBAb) on Chinese hamster ovary cells
expressing human FSH receptor (CHO-hFSH-R cells). We examined the TSBAb activity
of sera from hypothyroid patients who had a positive TBII to determine whether
these sera also block the effect of FSH on CHO-hFSH-R cells. Although human FSH I
3 (0.25-16 ng/ml) stimulated the production of intracellular cAMP in CHO-hFSH-R
cells with dose-responsive manner, neither TSAb nor TSBAb had such an effect on
the cells.
PMID- 10665998
TI - Uncoupling effect of anacardic acids from cashew nut shell oil on oxidative
phosphorylation of rat liver mitochondria.
AB - Anacardic acids are one of natural products found in not only the cashew nut
shell oil but also the nut and fruit juice. The present study was conducted to
investigate the uncoupling effect of anacardic acids on oxidative phosphorylation
of rat liver mitochondria using succinate (plus rotenone) as a substrate. Four
anacardic acids with C15:0, C15:1, C15:2 or C15:3 as an alkyl side chain
exhibited uncoupling effects similar to the classical uncoupler, 2,4
dinitrophenol on ADP/O ratio, state 4 and respiratory control ratio (RCR).
Anacardic acid with C15:1 side chain was most effective for uncoupling of these
compounds. Salicylic acid, which has no alkyl side chain, exhibited a very weak
uncoupling effect on oxidative phosphorylation. When the carboxyl group in
anacardic acids was lost converting them to the corresponding cardanols,
uncoupling activity dramatically decreased regardless of the number of double
bonds in the long alkyl chain. These results suggest that the C15 alkyl side
chain as well as the carboxyl group may play an important role in assisting the
uncoupling activity of anacardic acids in liver mitochondria of animals. This
study provides the first evidence of an uncoupling effect of anacardic acids on
liver mitochondria
PMID- 10665999
TI - Modulation of collagen synthesis by tumor necrosis factor alpha in cultured
vascular smooth muscle cells.
AB - Collagen synthesis in vascular smooth muscle cells (SMCs) after exposure to tumor
necrosis factor alpha (TNF-alpha) was investigated using a culture system. The
synthesis of collagenase-digestible proteins (CDP) and noncollagenous proteins
(NCP) was evaluated by the [3H]proline incorporation. It was shown that TNF-alpha
markedly suppresses the incorporation of [3H]proline into both CDP and NCP in
confluent cultures of SMCs but not in sparse cultures of the cells. Such a marked
suppression by TNF-alpha was not observed in confluent bovine aortic endothelial
cells and human fibroblastic IMR-90 cells. In confluent SMCs, the synthesis of
CDP was more strongly inhibited by TNF-alpha than that of NCP. When the CDP
synthesis was stimulated by transforming growth factor beta, TNF-alpha suppressed
the stimulation in both confluent and sparse SMCs. Human SMCs synthesized types
I, III, IV and V collagens; TNF-alpha markedly decreased the relative proportion
of types IV and V. It was therefore suggested that TNF-alpha modulates the
collagen synthesis by SMCs depending on their cell density and modifies the
formation of atherosclerotic lesions.
PMID- 10666000
TI - Tumor necrosis factor-alpha-mediated signal transduction in human neutrophils:
involvement of sphingomyelin metabolites in the priming effect of TNF-alpha on
the fMLP-stimulated superoxide production.
AB - We investigated the mechanism underlying the priming effect of TNF-alpha on fMLP
stimulated superoxide production in human neutrophils. TNF-alpha enhanced fMLP
stimulated superoxide production in a concentration-dependent manner. TNF-alpha
also induced sphingomyelin (SM) hydrolysis and increased the formation of its
metabolite, sphingosine-1-phosphate (SP-1-P). The treatment of neutrophils with
sphingomyelinase also resulted in a similar priming effect. C2 ceramide produced
a concentration-dependent inhibition of fMLP-stimulated superoxide production
within the concentration range of 1-30 microM. Sphingosine had a dual effect on
fMLP-stimulated superoxide generation, exhibiting a priming effect at lower
concentrations (0.2-1 microM), but an inhibitory effect at higher concentrations
(1-30 microM). SP-1-P (1-30 microM), showed a concentration-dependent enhancement
of fMLP stimulated superoxide production. Furthermore, after treating neutrophils
with DL-threo-dihydro-sphingosine, a competitive inhibitor of sphingosine kinase,
TNF-alpha produced a similar dual effect as observed with sphingosine. These
results strongly suggest that SM hydrolysis plays a key role in the intracellular
signal transduction mediating the TNF-alpha-mediated priming effect.
PMID- 10666001
TI - Supraspinal and spinal effects of [Phe1psi(CH2-NH)Gly2]-nociceptin(1-13)-NH2 on
nociception in the rat.
AB - A new derivative of the neuropeptide nociceptin (NC) has recently been developed.
This molecule, the pseudopeptide [Phe1psi(CH2-NH)Gly2]-nociceptin(1-13)-NH2 was
found to antagonize NC inhibitory effects in peripheral smooth muscle
preparations in vitro. However, contrasting results have appeared as regards its
pharmacodynamic profile in the CNS. Here, we investigated the pseudopeptide
effects, in vivo, on nociceptive responses in the rat. [Phe1psi(CH2-NH)Gly2]
nociceptin(1-13)-NH2 was administered intracerebroventricularly (i.c.v.) or
intrathecally (i.t.) (alone or in combination with NC), and tail-flick latencies
(TFL) to radiant heat were assessed. I.c.v. [Phe1psi(CH2-NH)Gly2]-nociceptin(1
13)-NH2 (1-10 nmol/rat) caused a short-lasting decrease (5 min) of TFL and did
not antagonize the threshold lowering effect of i.c.v. NC (1 nmol/rat). At the
spinal level, the i.t. administration (0.2-10 nmol/rat) of [Phe1psi(CH2-NH)Gly2]
nociceptin(1-13)-NH2 produced a dose-dependent and long-lasting antinociceptive
effect that was not modified by the administration of a high dose (30 nmol/rat
i.t.) of the opioid antagonist naloxone. The i.t. co-administration of the
pseudopeptide (10 nmol/rat) did not block the antinociceptive effect of i.t. NC
(10 nmol/rat). These data indicate that the pseudopeptide behaves as an NC
agonist at supraspinal and spinal levels in the rat tail-flick test of
nociception. These different profiles in the periphery and the CNS could suggest
differences between central and peripheral NC receptor/s and provide a basis for
further development of antagonist molecules suitable for their characterization.
PMID- 10666002
TI - Protective effect of aminoguanidine, a nitric oxide synthase inhibitor, against
carbon tetrachloride induced hepatotoxicity in mice.
AB - The present study was undertaken to evaluate the effect of aminoguanidine (AG) on
carbon tetrachloride (CCl4)-induced hepatotoxicity. Treatment of mice with CCl4
(20 microl/kg, i.p.) resulted in damage to centrilobular regions of the liver,
increase in serum aminotransferase and rise in lipid peroxides level 24 hours
after CCl4 administration. Pretreatment of mice with AG (50 mg/kg, i.p.) 30
minutes before CCl4 was found to protect mice from the CCl4-induced hepatic
toxicity. This protection was evident from the significant reduction in serum
aminotransferase, inhibition of lipid peroxidation and prevention of CCl4-induced
hepatic necrosis revealed by histopathology. Aminoguanidine, a relatively
specific inhibitor of inducible nitric oxide synthase, did not inhibit the in
vitro lipid peroxidation. Taken together, these data suggest a potential role of
nitric oxide as an important mediator of CCl4-induced hepatotoxicity.
PMID- 10666003
TI - The inhibition of GLUT1 glucose transport and cytochalasin B binding activity by
tricyclic antidepressants.
AB - Under normal metabolic conditions glucose is an important energy source for the
mammalian brain. Positron Emission Tomography studies of the central nervous
system have demonstrated that tricyclic antidepressant medications alter cerebral
metabolic function. The mode by which these drugs perturb metabolism is unknown.
In the present study the interactions of tricyclic antidepressants with the GLUT1
glucose transport protein is examined. Amitriptyline, nortriptyline, desipramine,
and imipramine all inhibit the influx of 3-O-methyl glucose into resealed
erythrocytes. This inhibition is observed with drug concentrations in the
millimolar range. All four antidepressants also noncompetitively displace
cytochalasin B binding to GLUT1. The K(I) for this displacement ranges from 0.56
to 1.43 millimolar. This value is in a range greater than that associated with
clinical doses and this effect may not be directly applicable to side effects
observed with normal use. The observed interaction of these drugs with GLUT1 may
reflect an affinity for other glucose-transport or glucose-binding proteins, and
may possibly contribute to tricyclic antidepressant toxicity.
PMID- 10666004
TI - Roles of endogenous prostaglandins and nitric oxide in inhibitions of gastric
emptying and accelerations of gastrointestinal transit by escins Ia, Ib, IIa, and
IIb in mice.
AB - We reported previously that escins Ia, Ib, IIa, and IIb, isolated from horse
chestnuts, inhibited the 30-min gastric emptying (GE) in mice. In this study, the
effects of escins Ia-IIb on gastrointestinal transit (GIT), and the roles of
endogenous prostaglandins (PGs) and nitric oxide (NO) in the effects of escins Ia
-IIb on GE and GIT were investigated in fasted mice. Escins Ia-IIb (12.5-50
mg/kg, p.o.) dose-dependently accelerated GIT. Both GE inhibitions and GIT
accelerations by escins Ia-IIb (25 mg/kg) were markedly attenuated by
pretreatment with indomethacin (10 mg/kg, s.c., an inhibitor of PGs synthesis).
Pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg, i.p., an
inhibitor of constitutive and inducible NO synthase) attenuated the effects of
escins Ia-IIb on GIT, but not on GE. The effect of L-NAME was reversed by L
arginine (600 mg/kg, i.p., a substrate of NO synthase), but not by D-arginine
(900 mg/kg, i.p., the enantiomer of L-arginine). The GIT accelerations of escins
Ia-IIb were not attenuated by pretreatment with D-NAME (10 mg/kg, i.p., the
enantiomer of L-NAME) or dexamethasone (5 mg/kg, i.p., an inhibitor of inducible
form of NO synthase). The results suggest that endogenous PGs play an important
role in both GE inhibitions and GIT accelerations, and constitutive NO is
involved in the GIT accelerations, by escins Ia--IIb in mice.
PMID- 10666005
TI - GIP biology and fat metabolism.
AB - The gastrointestinal hormone, gastric inhibitory polypeptide (GIP), is
synthesized and released from the duodenum and proximal jejunum postprandially.
Its release depends upon several factors including meal content and pre-existing
health status (ie. obesity, diabetes, age, etc.). It was initially discovered and
named for its gastric acid inhibitory properties. However, its more
physiologically relevant role appears to be as an insulinotropic agent with a
stimulatory effect on insulin release and synthesis. Accordingly, it was later
renamed glucose-dependent insulinotropic polypeptide because its action on
insulin release depends upon an increase in circulating levels of glucose. GIP is
considered to be one of the principle incretin factors of the enteroinsular axis.
The GIP receptor is a G-protein-coupled receptor belonging to the family of
secretin/VIP receptors. GIP receptor mRNA is widely distributed in peripheral
organs, including the pancreas, gut, adipose tissue, heart, adrenal cortex, and
brain, suggesting it may have other functions in addition to the ones mentioned
above. An overactive enteroinsular axis has been suggested to play a role in the
pathogenesis of diabetes and obesity. In addition to stimulating insulin release,
GIP has been shown to amplify the effect of insulin on target tissues. In adipose
tissue, GIP has been reported to (1) stimulate fatty acid synthesis, (2) enhance
insulin-stimulated incorporation of fatty acids into triglycerides, (3) increase
insulin receptor affinity, and (4) increase sensitivity of insulin-stimulated
glucose transport. In addition, although controversial, lipolytic properties of
GIP have been proposed. The mechanism of action of GIP-induced effects on
adipocytes is unknown, and it is unclear whether these effects of GIP on
adipocytes are direct or indirect. However, there is now evidence that GIP
receptors are expressed on adipocytes and that these receptors respond to GIP
stimulation. Given the location of its release and the timing of its release, GIP
is an ideal anabolic agent and expanding our understanding of its physiology will
be needed to determine its exact role in the etiology of diabetes mellitus and
obesity.
PMID- 10666006
TI - Electroencephalographic effects of thiopentone and its enantiomers in the rat.
AB - Electrophysiological studies with some chiral barbiturates have shown that one
enantiomer can be excitant while the other is depressant. Thiopentone, a chiral
barbiturate, has both differences in potency between enantiomers and biphasic
effects on the electroencephalogram (EEG). This study investigated whether a
differential EEG activity between the enantiomers of thiopentone could account
for the biphasic effects. Rats were administered rac-, R- or S-thiopentone to
determine the nature and time course of quantitative EEG effects. Two studies
using computer-controlled i.v. infusions of the three drugs were performed in
groups of animals previously prepared with EEG electrodes and/or arterial blood
sampling cannulae. Study 1 used several stepwise increments in plasma drug
concentration over 35 min, followed by washout. Study 2 used a 4 min period of
constant plasma drug concentration, followed by washout. In both studies, both
enantiomers and racemate caused an initial EEG activation followed by
deactivation. Quantitative enantioselectivity was found for depression. The
extent of depression was significantly less for R-thiopentone (P=0.008) and
racthiopentone (P=0.038) than for S-thiopentone; recovery from depression
appeared to be faster for R-thiopentone than either rac- or S-thiopentone.
Fatality was only found with S-thiopentone (3/7 animals in Study 2). R
thiopentone plasma concentrations were approximately 8% less than those of S
thiopentone in rats treated with racthiopentone. Although small differences in
clearance between enantiomers were found that may influence recovery, they were
not large enough to account for the reported differences in potency between the
two enantiomers.
PMID- 10666007
TI - Soy based diet attenuates the development of hypertension when compared to casein
based diet in spontaneously hypertensive rat.
AB - The purpose of this study was to compare the effects of soy and casein based
diets on blood pressure and cardiovascular functions in male and female
spontaneously hypertensive rats (SHR). The systolic blood pressure was measured
at the beginning and at the end of study. After a five week supplementation
period with three different diets, the rats were decapitated and arterial
responses and the weight-to-body weight-ratios of the organs were studied. The
development of hypertension was attenuated in both female and male rats on soy
protein diet when compared to the casein diet. Soy based diet lowered serum total
cholesterol level when compared to the control diet. Both casein and soy protein
supplementation in diet induced a significant renal hypertrophy in both female
and male SHR rats when compared to SHR rats on the control diet. Soy protein
supplementation reduced significantly serum estradiol-17beta concentration when
compared to the control diet. There were no differences in the serum testosterone
concentrations between the diet groups. When compared to the casein based diet
the soy based diet attenuated the development of hypertension and decreased serum
total cholesterol level in SHRs. These effects were independent of gender. The
mechanisms and clinical importance of these findings remain to be clarified.
PMID- 10666009
TI - Expression of adhesion receptors on rat limb bud cells and results of treatment
with a thalidomide derivative.
AB - The expression of several adhesion surface receptors was studied on cells of
early limb bud development of 58 Wistar rats treated orally with two daily doses
of the thalidomide derivative EM12 (2 x 50 mg/kg body weight) from day 7 to 10 of
pregnancy. EM12 is a more potent teratogen than thalidomide. Limb bud cells of 56
untreated animals served as controls. The studies revealed that the integrins
CD11a, CD11b, CD18, CD49d, and CD61, as well as the additional adhesion receptors
CD54, CD62L, and the transferrin receptor CD71 were expressed on day 11 of
gestation to various degrees on these embryonic cells. In contrast to results of
previous studies with a non-human primate (Callithrix jacchus) there was no down
regulation of any of these receptors on the surface of limb bud cells of the rat
embryos after treatment with EM12. This result is in accordance with the lack of
teratogenicity in this rodent species.
PMID- 10666008
TI - Fatty liver and hyperlipidemia in IDDM (insulin-dependent diabetes mellitus) of
streptozotocin-treated shrews.
AB - Severe IDDM (insulin-dependent diabetes mellitus) was produced in the musk shrew
(Suncus murimus, Insectivora) by a high dose (a single intraperitoneal injection
of 100 mg/kg Body Weight) of streptozotocin (STZ) injection. All shrews that were
administered a high dose of STZ exhibited hyperglycemia (449 +/- 16 mg/dl vs 73
+/- 4 mg/dl in controls) and hypoinsulinemia(0.25 +/- 0.07 ng/ml vs 10.96 +/-
1.97 ng/ml in controls) with ketosuria 10 days after injection. Their livers were
enlarged and exhibited ayellowish-brown color with marked triglyceride (TG)
accumulation (63.25 +/- 7.10 mg/g Liver vs 2.11 +/- 0.19 mg/g Liver in controls).
It is probable that the increased influx of fatty acids into the liver induced by
hypoinsulinemia and the low capacity of excretion of lipoprotein secretion from
liver in the musk shrew resulting from a deficiency of apolipoprotein B synthesis
play important roles in fatty liver formation. Hyperlipidemia was another feature
in shrews with severe IDDM. The blood TG level was especially high in these
shrews (899 +/- 178 mg/dl vs 23 +/- 5 mg/dl in controls). These results indicate
that the IDDM shrew, induced by high doses of STZ, is a unique model
characterized by fatty liver and hyperlipidemia and may be useful for studying
lipid metabolism of IDDM.
PMID- 10666010
TI - Unexpected suppression of free phenytoin concentration by salicylate in uremic
sera due to the presence of inhibitors: MALDI mass spectrometric determination of
molecular weight range of inhibitors.
AB - Salicylate displaces phenytoin from protein binding leading to an increase in
free phenytoin concentration. We observed unexpected decreases in free phenytoin
concentration in the presence of salicylate. Serum pools containing no phenytoin
or salicylate were supplemented with the same concentrations of phenytoin. Then
to the aliquots of the individual pool, no salicylate (control), 150, 300 and 500
microg/ml of salicylate (therapeutic range: 15-300 microg/ml) were added.
Specimens were incubated at 37 degrees C for 2 h and after re-equilibration at
room temperature for 20 min, total and free phenytoin (in the protein free
ultrafiltrates) concentrations were measured using fluorescence polarization
immunoassay on the TDx/FLX analyzer. We observed an increase in free phenytoin
concentration from 1.91 microg/ml (in the absence of salicylate) to 2.39
microg/ml in the presence of 500 microg/ml salicylate (total phenytoin: 13.3
microg/ml) in the normal pool. In sharp contrast, the free phenytoin
concentrations decreased from an initial concentration of 3.82 microg/ml to 2.52
microg/ml in the presence of 500 microg/ml of salicylate (total phenytoin: 13.2
microg/ml) in the uremic pool. We also treated the uremic pool with activated
charcoal. In the original uremic pool, the initial free phenytoin concentration
was 3.05 microg/ml and the free concentrations then decreased to 2.28 microg/ml
in the presence of 300 microg/ml of salicylate. In contrast, in the charcoal
treated pool, the initial free phenytoin concentration increased from 1.61
microg/ml to 3.23 microg/ml in the presence of 300 microg/ml of salicylate. More
interestingly when uremic toxins were extracted back from charcoal with methanol
and the dry residue was added to an aliquot of normal serum, the normal serum
behaved like a uremic serum and free phenytoin concentration was significantly
decreased in the presence of salicylate. When an aliquot of methanol extract was
studied by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (scan up
to 10,000), we observed no peak at molecular weight over 551, indicating that
these inhibitors are small molecules. We also identified hippuric acid as one of
the inhibitors.
PMID- 10666011
TI - Melatonin increases muscle and liver glycogen content in nonexercised and
exercised rats.
AB - The effects of melatonin on several parameters of carbohydrate and lipid
metabolism were investigated in exercised and nonexercised rats. Animals were run
to exhaustion on a rodent treadmill at 24 m/min and a 12% slope. Exercise
resulted in a significant hypoglycemia and increased plasma levels of lactate and
beta-hydroxybutyrate, together with a significant reduction of glycogen in muscle
and liver. Muscle and liver glycogen content was elevated and plasma free fatty
acid decreased in nonexercised animals receiving melatonin (0.5 or 2.0 mg/kg
i.p). Melatonin at 2.0 mg/kg reduced plasma lactate and increased lactate
concentration in liver. When compared to untreated exercised animals glycemia and
muscle and liver glycogen content were significantly higher in melatonin-treated
exercised animals, while plasma and liver lactate and plasma beta-hydroxybutyrate
were significantly reduced. Our data indicate that melatonin preserves glycogen
stores in exercised rats through changes in carbohydrate and lipid utilization.
PMID- 10666012
TI - Mode of action of sesame lignans in protecting low-density lipoprotein against
oxidative damage in vitro.
AB - We investigated the antioxidant properties of sesaminol, a major component of
sesame oil, on the oxidative modification of human low-density lipoprotein (LDL)
in vitro. Sesaminol inhibited the Cu2+-induced lipid peroxidation in LDL in a
concentration-dependent manner with an IC50 36.0 +/- 10.0 nM. Sesaminol was a
more effective scavenger than either alpha-tocopherol or probucol in reducing the
peroxyl radicals derived from 2,2'-azobis (2-amidinopropane) dihydrochloride
(AAPH) in aqueous solution. In addition, as determined by the secondary products
of lipid peroxidation identified by using immunochemical methods, sesaminol
completely inhibited the formation of 4-hydroxy-nonenal (4-HNE)- and
malondialdehyde (MDA)-adducts in a concentration-dependent manner. Probucol and
alpha-tocopherol at the same concentration exhibited a lesser inhibitory effect.
Our findings suggest that sesaminol is a potentially effective antioxidant that
can protect LDL against the oxidation.
PMID- 10666013
TI - Negative NO3- difference in human coronary circulation with severe
atherosclerotic stenosis.
AB - To examine whether or not the levels of NOx (nitrite; NO2- and nitrate; NO3-) in
coronary circulating blood reflect endothelial dysfunction due to coronary
atherosclerosis, NOx levels in plasma obtained from ostium of left coronary
artery and coronary sinus of patients who complained of chest pain were evaluated
in relation to their coronary angiographic findings. Prior to the study, a HPLC
Griess system for NOx measurement was critically evaluated. This system has a
detection limit of 0.1 microM of NO2- and NO3- by 10 microl of loading and was
able to distinguish a difference of 0.1-0.2 microM of these substances. Heparin
(1 U/10 microl) did not affect the detective and discriminative abilities. NO3-
difference, calculated from sino-arterial difference of NO3-, was almost zero (
0.2 +/- 0.2 microM) in patients with either normal coronary arteries or mild
organic coronary stenosis (< or = 20% narrowing), while a significant negative
value (-5.9 +/- 1.7 microM) was obtained from patients with significant stenosis
(> or = 70% narrowing) in the left coronary arteries. These results demonstrate
reliable ability on the HPLC-Griess system in evaluating NO2- and NO3- in
biological samples, and that the negative NO3- difference through coronary
circulation may reflect endothelial dysfunction in the patients with coronary
atherosclerosis with severe organic stenosis.
PMID- 10666014
TI - Pulmonary protective effects of curcumin against paraquat toxicity.
AB - An early feature of paraquat (PQ) toxicity is the influx of inflammatory cells,
releasing proteolytic enzymes and oxygen free radicals, which can destroy the
lung epithelium and result in pulmonary fibrosis. Therefore, the ability to
suppress early lung injury seems to be an appropriate therapy of pulmonary damage
before the development of irreversible fibrosis. Here I show curcumin confers
remarkable protection against PQ lung injury. A single intraperitoneal injection
of PQ (50 mg/kg) resulted in a significant rise in the levels of protein,
angiotensin converting enzyme (ACE), alkaline phosphatase (AKP), N-acetyl-beta-D
glucosaminidase (NAG) and thiobarbituric acid reactive substances (TBARS), and
neutrophils in the bronchoalveolar lavage fluid (BALF), while a decrease in
glutathione levels. In paraquat rats bronchoalveolar lavage (BAL) cell TBARS
concentration was increased with a simultaneous decrease in glutathione content.
In addition, the data also demonstrated that PQ caused a decrease in ACE and
glutathione levels and an increase in levels of TBARS and myeloperoxidase (MPO)
activity in the lung. Interestingly, curcumin prevented the general toxicity and
mortality induced by PQ and blocked the rise in BALF protein, ACE, AKP, NAG TBARS
and neutrophils. Similarly, curcumin prevented the rise in TBARS content in both
BAL cell and lung tissue and MPO activity of the lung. In addition, PQ induced
reduction in lung ACE and BAL cell and lung glutathione levels was abolished by
curcumin treatment. These findings indicate that curcumin has important
therapeutic implications in facilitating the early suppression of PQ lung injury.
PMID- 10666015
TI - Y-27632 inhibits gastric motility in conscious rats.
AB - Y-27632, a highly selective inhibitor of p160ROCK, desensitizes the smooth muscle
to Ca2+ and inhibits smooth muscle contraction. While this drug has the potential
to become a novel drug for hypertension, it might also affect other smooth
muscle, including that of gastrointestinal tract. We studied the effects of Y
27632 on gastric contractions in conscious rats. Strain gauge force transducers
were sutured onto the serosal side of the gastric antrum and contractions were
recorded before and after the intravenous injection of Y-27632. Doses of 1.0
mg/kg to 10 mg/kg significantly decreased contraction amplitude and the motility
index in a dose dependent manner. With 10 mg/kg, the mean amplitude was decreased
by up to 69 +/- 14% and the motility index by up to 81 +/- 7%. The change
occurred immediately after drug infusion and lasted for 3.5h. Contraction
frequency showed only a slight decrease. No signs of bowel obstruction were
observed. These results indicate that Rho-mediated Ca sensitization has a role in
the physiologic contractions of gastric smooth muscle in rats. Y-27632 is useful
to investigate the physiology of gastrointestinal motility.
PMID- 10666017
TI - Unravelling the spindle
PMID- 10666016
TI - Anti-phospholipase A2 and anti-inflammatory activity of Santolina
chamaecyparissus.
AB - The activity of the Santolina chamaecyparissus methanol extract was tested
against the phospholipase A2 (PLA2)-induced mouse paw edema and in vitro
inhibition of PLA2 activity. After fractionation, only the dichloromethane
extract was active against the PLA2 in vitro test. In addition, it reduced the
edema induced by arachidonic acid, and by 12-O-tetradecanoylphorbol-13-acetate in
a multidose test. After chromatography on silicagel and gel filtration on
Sephadex, and using an in vitro anti-PLA2 assay-guided process, we have isolated
and identified from the dichloromethane extract the flavone nepetin and four
sesquiterpenes.
PMID- 10666018
TI - Calcium sparks in smooth muscle.
AB - Local intracellular Ca(2+) transients, termed Ca(2+) sparks, are caused by the
coordinated opening of a cluster of ryanodine-sensitive Ca(2+) release channels
in the sarcoplasmic reticulum of smooth muscle cells. Ca(2+) sparks are activated
by Ca(2+) entry through dihydropyridine-sensitive voltage-dependent Ca(2+)
channels, although the precise mechanisms of communication of Ca(2+) entry to
Ca(2+) spark activation are not clear in smooth muscle. Ca(2+) sparks act as a
positive-feedback element to increase smooth muscle contractility, directly by
contributing to the global cytoplasmic Ca(2+) concentration ([Ca(2+)]) and
indirectly by increasing Ca(2+) entry through membrane potential depolarization,
caused by activation of Ca(2+) spark-activated Cl(-) channels. Ca(2+) sparks also
have a profound negative-feedback effect on contractility by decreasing Ca(2+)
entry through membrane potential hyperpolarization, caused by activation of large
conductance, Ca(2+)-sensitive K(+) channels. In this review, the roles of Ca(2+)
sparks in positive- and negative-feedback regulation of smooth muscle function
are explored. We also propose that frequency and amplitude modulation of Ca(2+)
sparks by contractile and relaxant agents is an important mechanism to regulate
smooth muscle function.
PMID- 10666019
TI - Focus on "Sodium 4-phenylbutyrate downregulates Hsc70: implications for
intracellular trafficking of DeltaF508-CFTR".
PMID- 10666020
TI - Sodium 4-phenylbutyrate downregulates Hsc70: implications for intracellular
trafficking of DeltaF508-CFTR.
AB - The most common mutation of the cystic fibrosis transmembrane conductance
regulator (CFTR), DeltaF508, is a trafficking mutant that has prolonged
associations with molecular chaperones and is rapidly degraded, at least in part
by the ubiquitin-proteasome system. Sodium 4-phenylbutyrate (4PBA) improves
DeltaF508-CFTR trafficking and function in vitro in cystic fibrosis epithelial
cells and in vivo. To further understand the mechanism of action of 4PBA, we
tested the hypothesis that 4PBA modulates the targeting of DeltaF508-CFTR for
ubiquitination and degradation by reducing the expression of Hsc70 in cystic
fibrosis epithelial cells. IB3-1 cells (genotype DeltaF508/W1282X) that were
treated with 0.05-5 mM 4PBA for 2 days in culture demonstrated a dose-dependent
reduction in Hsc70 protein immunoreactivity and mRNA levels. Immunoprecipitation
with Hsc70-specific antiserum demonstrated that Hsc70 and CFTR associated under
control conditions and that treatment with 4PBA reduced these complexes. Levels
of immunoreactive Hsp40, Hdj2, Hsp70, Hsp90, and calnexin were unaffected by 4PBA
treatment. These data suggest that 4PBA may improve DeltaF508-CFTR trafficking by
allowing a greater proportion of mutant CFTR to escape association with Hsc70.
PMID- 10666021
TI - Regulation of intestinal vitamin B(2) absorption. Focus on "Riboflavin uptake by
human-derived colonic epithelial NCM460 cells".
PMID- 10666022
TI - Riboflavin uptake by human-derived colonic epithelial NCM460 cells.
AB - Normal microflora of the large intestine synthesize a number of water-soluble
vitamins including riboflavin (RF). Recent studies have shown that colonic
epithelial cells possess an efficient carrier-mediated mechanism for absorbing
some of these micronutrients. The aim of the present study was to determine
whether colonic cells also possess a carrier-mediated mechanism for RF uptake
and, if so, to characterize this mechanism and study its cellular regulation.
Confluent monolayers of the human-derived nontransformed colonic epithelial cells
NCM460 and [(3)H]RF were used in the study. Uptake of RF was found to be 1)
appreciable and temperature and energy dependent; 2) Na(+) independent; 3)
saturable as a function of concentration with an apparent K(m) of 0.14 microM and
V(max) of 3.29 pmol x mg protein(-1) x 3 min(-1); 4) inhibited by the structural
analogs lumiflavin and lumichrome (K(i) of 1.8 and 14.1 microM, respectively) but
not by the unrelated biotin; 5) inhibited in a competitive manner by the membrane
transport inhibitor amiloride (K(i) = 0.86 mM) but not by furosemide, DIDS, or
probenecid; 6) adaptively regulated by extracellular RF levels with a significant
and specific upregulation and downregulation in RF uptake in RF-deficient and
oversupplemented conditions, respectively; and 7) modulated by an intracellular
Ca(2+)/calmodulin-mediated pathway. These studies demonstrate for the first time
the existence of a specialized carrier-mediated mechanism for RF uptake in an in
vitro cellular model system of human colonocytes. This mechanism appears to be
regulated by extracellular substrate level and by an intracellular
Ca(2+)/calmodulin-mediated pathway. It is suggested that the identified transport
system may be involved in the absorption of bacterially synthesized RF in the
large intestine and that this source of RF may contribute toward RF homeostasis,
especially that of colonocytes.
PMID- 10666023
TI - Charged residues in the M2 region of alpha-hENaC play a role in channel
conductance.
AB - The epithelial Na(+) channel (ENaC) is a low-conductance channel that is highly
selective for Na(+) and Li(+) over K(+) and impermeable to anions. The molecular
basis underlying these conduction properties is not well known. Previous studies
with the ENaC subunits demonstrated that the M2 region of alpha-ENaC is critical
to channel function. Here we examine the effects of reversing the negative
charges of highly conserved amino acids in alpha-subunit human ENaC (alpha-hENaC)
M1 and M2 domains. Whole cell and single-channel current measurements indicated
that the M2 mutations E568R, E571R, and D575R significantly decreased channel
conductance but did not affect Na(+):K(+) permeability. We observed no functional
perturbations from the M1 mutation E108R. Whole cell amiloride-sensitive current
recorded from oocytes injected with the M2 alpha-hENaC mutants along with wild
type (wt) beta- and gamma-hENaC was low (46-93 nA) compared with the wt channel
(1-3 microA). To determine whether this reduced macroscopic current resulted from
a decreased number of mutant channels at the plasma membrane, we coexpressed
mutant alpha-hENaC subunits with green fluorescent protein-tagged beta- and gamma
subunits. Confocal laser scanning microscopy of oocytes demonstrated that plasma
membrane localization of the mutant channels was the same as that of wt. These
experiments demonstrate that acidic residues in the second transmembrane domain
of alpha-hENaC affect ion permeation and are thus critical components of the
conductive pore of ENaC.
PMID- 10666024
TI - Hyperbaric oxygen downregulates ICAM-1 expression induced by hypoxia and
hypoglycemia: the role of NOS.
AB - Hyperbaric oxygen (HBO) is being studied as a therapeutic intervention for
ischemia/reperfusion (I/R) injury. We have developed an in vitro endothelial cell
model of I/R injury to study the impact of HBO on the expression of intercellular
adhesion molecule-1 (ICAM-1) and polymorphonuclear leukocyte (PMN) adhesion.
Human umbilical vein endothelial cell (HUVEC) and bovine aortic endothelial cell
(BAEC) induction of ICAM-1 required simultaneous exposure to both hypoxia and
hypoglycemia as determined by confocal laser scanning microscopy, ELISA, and
Western blot. HBO treatment reduced the expression of ICAM-1 to control levels.
Adhesion of PMNs to BAECs was increased following hypoxia/hypoglycemia exposure
(3. 4-fold, P < 0.01) and was reduced to control levels with exposure to HBO (P =
0.67). Exposure of HUVECs and BAECs to HBO induced the synthesis of endothelial
cell nitric oxide synthase (eNOS). The NOS inhibitor nitro-L-arginine methyl
ester attenuated HBO-mediated inhibition of ICAM-1 expression. Our findings
suggest that the beneficial effects of HBO in treating I/R injury may be mediated
in part by inhibition of ICAM-1 expression through the induction of eNOS.
PMID- 10666025
TI - Role of K(+) channel expression in polyamine-dependent intestinal epithelial cell
migration.
AB - Polyamines are essential for cell migration during early mucosal restitution
after wounding in the gastrointestinal tract. Activity of voltage-gated K(+)
channels (Kv) controls membrane potential (E(m)) that regulates cytoplasmic free
Ca(2+) concentration ([Ca(2+)](cyt)) by governing the driving force for Ca(2+)
influx. This study determined whether polyamines are required for the stimulation
of cell migration by altering K(+) channel gene expression, E(m), and
[Ca(2+)](cyt) in intestinal epithelial cells (IEC-6). The specific inhibitor of
polyamine synthesis, alpha-difluoromethylornithine (DFMO, 5 mM), depleted
cellular polyamines (putrescine, spermidine, and spermine), selectively inhibited
Kv1.1 channel (a delayed-rectifier Kv channel) expression, and resulted in
membrane depolarization. Because IEC-6 cells did not express voltage-gated Ca(2+)
channels, the depolarized E(m) in DFMO-treated cells decreased [Ca(2+)](cyt) as a
result of reduced driving force for Ca(2+) influx through capacitative Ca(2+)
entry. Migration was reduced by 80% in the polyamine-deficient cells. Exogenous
spermidine not only reversed the effects of DFMO on Kv1.1 channel expression,
E(m), and [Ca(2+)](cyt) but also restored cell migration to normal. Removal of
extracellular Ca(2+) or blockade of Kv channels (by 4-aminopyridine, 1-5 mM)
significantly inhibited normal cell migration and prevented the restoration of
cell migration by exogenous spermidine in polyamine-deficient cells. These
results suggest that polyamine-dependent intestinal epithelial cell migration may
be due partially to an increase of Kv1.1 channel expression. The subsequent
membrane hyperpolarization raises [Ca(2+)](cyt) by increasing the driving force
(the electrochemical gradient) for Ca(2+) influx and thus stimulates cell
migration.
PMID- 10666026
TI - Differentiation of human fetal osteoblastic cells and gap junctional
intercellular communication.
AB - Gap junctional channels facilitate intercellular communication and in doing so
may contribute to cellular differentiation. To test this hypothesis, we examined
gap junction expression and function in a temperature-sensitive human fetal
osteoblastic cell line (hFOB 1.19) that when cultured at 37 degrees C
proliferates rapidly but when cultured at 39.5 degrees C proliferates slowly and
displays increased alkaline phosphatase activity and osteocalcin synthesis. We
found that hFOB 1.19 cells express abundant connexin 43 (Cx43) protein and mRNA.
In contrast, Cx45 mRNA was expressed to a lesser degree, and Cx26 and Cx32 mRNA
were not detected. Culturing hFOB 1. 19 cells at 39.5 degrees C, relative to 37
degrees C, inhibited proliferation, increased Cx43 mRNA and protein expression,
and increased gap junctional intercellular communication (GJIC). Blocking GJIC
with 18alpha-glycyrrhetinic acid prevented the increase in alkaline phosphatase
activity resulting from culture at 39.5 degrees C but did not affect osteocalcin
levels. These results suggest that gap junction function and expression parallel
osteoblastic differentiation and contribute to the expression of alkaline
phosphatase activity, a marker for fully differentiated osteoblastic cells.
PMID- 10666027
TI - Nuclear redistribution of tonicity-responsive enhancer binding protein requires
proteasome activity.
AB - Tonicity-responsive enhancer binding protein (TonEBP) is the transcription factor
that regulates tonicity-responsive expression of the genes for the sodium-myo
inositol cotransporter (SMIT) and the sodium-chloride-betaine cotransporter
(BGT1). Hypertonicity stimulates the activity of TonEBP due to a combination of
increased protein abundance and increased nuclear distribution (proportion of
TonEBP that is in the nucleus). We found that inhibitors of proteasome activity
markedly reduce the induction of SMIT and BGT1 mRNA in response to hypertonicity.
These inhibitors also reduce hypertonicity-induced stimulation of expression of a
reporter gene controlled by the tonicity-responsive enhancer. Western and
immunohistochemical analyses revealed that the proteasome inhibitors reduce the
hypertonicity-induced increase of TonEBP in the nucleus by inhibiting its nuclear
redistribution without affecting its abundance. Although the nuclear distribution
of TonEBP is sensitive to inhibition of proteasome activity as is that of nuclear
factor (NF)-kappaB, the signaling pathways appear to be different in that
hypertonicity does not affect the nuclear distribution of NF-kappaB. Conversely,
treatment with tumor necrosis factor-alpha increases the nuclear distribution of
NF-kappaB but not TonEBP.
PMID- 10666028
TI - Inhibition of ornithine decarboxylase induces STAT3 tyrosine phosphorylation and
DNA binding in IEC-6 cells.
AB - Polyamines are required for the proliferation of the rat intestinal mucosal IEC-6
cell line. Ornithine decarboxylase (ODC) is the enzyme that catalyzes the first
step in polyamine synthesis. ODC inhibition not only leads to polyamine depletion
but also leads to inhibition of cell proliferation and regulates the expression
of the immediate-early genes c-fos, c-myc, and c-jun. Members of the signal
transducers and activators of transcription (STAT) transcription factor family
bind to the sis-inducible element (SIE) present in the promoters to regulate the
expression of a variety of important genes. In the present study, we tested the
hypothesis that the STAT3 transcription factor, which is responsible for
activation of the acute phase response genes, is activated after inhibition of
ODC. We found that inhibition of ODC rapidly induces STAT3 activation as
determined by STAT3 tyrosine phosphorylation, translocation of STAT3 from the
cytoplasm into the nucleus, and the presence of STAT3 in SIE-dependent DNA
protein complexes. STAT3 activation upon inhibition of ODC was accompanied by the
activation of a STAT3-dependent reporter construct. Moreover, prolonged polyamine
depletion resulted in downregulation of cellular STAT3 levels.
PMID- 10666029
TI - Cyclic nucleotide-gated cation channels mediate sodium and calcium influx in rat
colon.
AB - We found mRNA for the three isoforms of the cyclic nucleotide-gated nonselective
cation channel expressed in the mucosal layer of the rat intestine from the
duodenum to the colon and in intestinal epithelial cell lines in culture. Because
these channels are permeable to sodium and calcium and are stimulated by cGMP or
cAMP, we measured 8-bromo-cGMP-stimulated sodium-mediated short-circuit current
(I(sc)) in proximal and distal colon and unidirectional (45)Ca(2+) fluxes in
proximal colon to determine whether these channels could mediate transepithelial
sodium and calcium absorption across the colon. Sodium-mediated I(sc), stimulated
by 8-bromo-cGMP, were inhibited by dichlorobenzamil and l-cis-diltiazem, blockers
of cyclic nucleotide-gated cation channels, suggesting that these ion channels
can mediate transepithelial sodium absorption. Sodium-mediated I(sc) and net
transepithelial (45)Ca(2+) absorption were stimulated by heat-stable toxin from
Escherichia coli that increases cGMP. Addition of l-cis-diltiazem inhibited the
enhanced transepithelial absorption of both ions. These results suggest that
cyclic nucleotide-gated cation channels simultaneously increase net sodium and
calcium absorption in the colon of the rat.
PMID- 10666030
TI - CCK stimulates mob-1 expression and NF-kappaB activation via protein kinase C and
intracellular Ca(2+).
AB - Supraphysiological concentrations of cholecystokinin (CCK) induce chemokine
expression in rat pancreatic acini through the activation of the transcription
factor NF-kappaB. In the current study, the intracellular signals involved in
these pathophysiological effects of CCK were investigated. CCK induction of mob-1
expression in isolated rat pancreatic acini was blocked by the protein kinase C
(PKC) inhibitors GF-109203X and Ro-32-0432 and by the intracellular Ca(2+)
chelator BAPTA. CCK induced NF-kappaB nuclear translocation, and DNA binding was
also blocked by GF-109203X and BAPTA. Direct activation of PKC with TPA induced
mob-1 chemokine expression and activated NF-kappaB DNA binding to a similar
extent as did CCK. Increasing intracellular Ca(2+) using ionomycin had no effect
on mob-1 mRNA levels or NF-kappaB activity. Both CCK and TPA treatments decreased
inhibitory kappaB-alpha (IkappaB-alpha) levels, whereas ionomycin had no effect.
However, the effects of TPA on IkappaB-alpha degradation were less complete than
for CCK. In combination, TPA and ionomycin degraded IkappaB-alpha to a similar
extent as CCK. Therefore, activation of NF-kappaB and mob-1 expression by
supraphysiological CCK is likely mediated by both PKC activation and elevated
intracellular Ca(2+).
PMID- 10666031
TI - Purinergic activation of spontaneous transient outward currents in guinea pig
taenia colonic myocytes.
AB - Spontaneous transient outward currents (STOCs) were recorded from smooth muscle
cells of the guinea pig taenia coli using the whole cell patch-clamp technique.
STOCs were resolved at potentials positive to -50 mV. Treating cells with
caffeine (1 mM) caused a burst of outward currents followed by inhibition of
STOCs. Replacing extracellular Ca(2+) with equimolar Mn(2+) caused STOCs to "run
down. " Iberiotoxin (200 nM) or charybdotoxin (ChTX; 200 nM) inhibited large
amplitude STOCs, but small-amplitude "mini-STOCs" remained in the presence of
these drugs. Mini-STOCs were reduced by apamin (500 nM), an inhibitor of small
conductance Ca(2+)-activated K(+) channels (SK channels). Application of ATP or 2
methylthioadenosine 5'-triphosphate (2-MeS-ATP) increased the frequency of STOCs.
The effects of 2-MeS-ATP persisted in the presence of charybdotoxin but were
blocked by combination of ChTX (200 nM) and apamin (500 nM). 2-MeS-ATP did not
increase STOCs in the presence of pyridoxal phosphate 6-azophenyl-2',4'
disulfonic acid, a P(2) receptor blocker. Similarly, pretreatment of cells with U
73122 (1 microM), an inhibitor of phospholipase C (PLC), abolished the effects of
2-MeS-ATP. Xestospongin C, an inositol 1,4,5-trisphosphate (IP(3)) receptor
blocker, attenuated STOCs, but these events were not affected by ryanodine. The
data suggest that purinergic activation through P(2Y) receptors results in
localized Ca(2+) release via PLC- and IP(3)-dependent mechanisms. Release of
Ca(2+) is coupled to STOCs, which are composed of currents mediated by large
conductance Ca(2+)-activated K(+) channels and SK channels. The latter are
thought to mediate hyperpolarization and relaxation responses of gastrointestinal
muscles to inhibitory purinergic stimulation.
PMID- 10666032
TI - Endoplasmic reticulum Ca(2+)-ATPase inhibitors stimulate membrane guanylate
cyclase in pancreatic acinar cells.
AB - In this study, we show that particulate guanylate cyclase (GC) is present in rat
pancreatic acinar cells and is located both on plasma membrane and membranes of
endoplasmic reticulum (ER). Western blot analysis indicates that the enzyme
isoform GC-A is present in the acinar cell membranes. The specific inhibitors of
ER Ca(2+)-ATPase thapsigargin, 2,5-di-(t-butyl)-1,4-hydroquinone (BHQ), and
cyclopiazonic acid all activated particulate GC in pancreatic acini, both in
membrane fractions and intact cells. These inhibitors also induced
dephosphorylation of GC. Dose dependencies of Ca(2+)-ATPase inhibition and GC
activation by BHQ are very similar, and those for thapsigargin partially overlap.
ER Ca(2+)-ATPase and GC are coimmunoprecipitated both by antisera against
membrane GC and by antisera against ER Ca(2+)-ATPase, suggesting a physical
association between the two enzymes. The results suggest that thapsigargin and
the other inhibitors act through ER Ca(2+)-ATPase to activate membrane GC in
pancreatic acinar cells, although their direct effect on GC cannot be excluded.
PMID- 10666033
TI - Ras signaling in the inner medullary cell response to urea and NaCl.
AB - The small guanine nucleotide-binding protein Ras, activated by peptide mitogens
and other stimuli, regulates downstream signaling events to influence
transcription. The role of Ras in solute signaling to gene regulation was
investigated in the murine inner medullary collecting duct (mIMCD3) cell line.
Urea treatment (100-200 mM), but not sham treatment, increased Ras activation
124% at 2 min; the effect of NaCl did not achieve statistical significance. To
determine the contribution of Ras activation to urea-inducible signal
transduction, mIMCD3 cells were stably transfected with an expression plasmid
encoding a dominant negative-acting N17Ras mutant driven by a dexamethasone
inducible (murine mammary tumor virus) promoter. After 24 h of induction,
selected cell lines exhibited sufficient N17Ras overexpression to abolish
epidermal growth factor- and hypotonicity-mediated signaling to extracellular
signal-regulated kinase (ERK) phosphorylation, as determined by immunoblotting.
Conditional N17Ras overexpression inhibited urea- and NaCl-inducible ERK
phosphorylation by 40-50%, but only at 15 min, and not 5 min, of treatment.
N17Ras induction, however, almost completely inhibited urea-inducible Egr-1
transcription, as quantitated by luciferase reporter gene assay, but failed to
influence tonicity-inducible (TonE-mediated) transcription. N17Ras overexpression
also blocked urea-inducible expression of the transcription factor Gadd153 but
did not influence osmotic or urea-inducible apoptosis. In addition, urea
treatment induced recruitment of the Ras activator Sos to the plasma membrane.
Taken together, these observations suggest a role for Ras signaling in the IMCD
cell response to urea stress.
PMID- 10666034
TI - K-Cl cotransport in vascular smooth muscle and erythrocytes: possible implication
in vasodilation.
AB - K-Cl cotransport, the electroneutral-coupled movement of K and Cl ions, plays an
important role in regulatory volume decrease. We recently reported that nitrite,
a nitric oxide derivative possessing potent vasodilation properties, stimulates K
Cl cotransport in low-K sheep red blood cells (LK SRBCs). We hypothesized that
activation of vascular smooth muscle (VSM) K-Cl cotransport by vasodilators
decreases VSM tension. Here we tested this hypothesis by comparing the effects of
commonly used vasodilators, hydralazine (HYZ), sodium nitroprusside, isosorbide
mononitrate, and pentaerythritol, on K-Cl cotransport in LK SRBCs and in primary
cultures of rat VSM cells (VSMCs) and of HYZ-induced K-Cl cotransport activation
on relaxation of isolated porcine coronary rings. K-Cl cotransport was measured
as the Cl-dependent K efflux or Rb influx in the presence and absence of
inhibitors for other K/Rb transport pathways. All vasodilators activated K-Cl
cotransport in LK SRBCs and HYZ in VSMCs, and this activation was inhibited by
calyculin and genistein, two inhibitors of K-Cl cotransport. KT-5823, a specific
inhibitor of protein kinase G, abolished the sodium nitroprusside-stimulated K-Cl
cotransport in LK SRBCs, suggesting involvement of the cGMP pathway in K-Cl
cotransport activation. Hydralazine, in a dose-dependent manner, and sodium
nitroprusside relaxed (independently of the endothelium) precontracted arteries
when only K-Cl cotransport was operating and other pathways for K/Rb transport,
including the Ca-activated K channel, were inhibited. Our findings suggest that K
Cl cotransport may be involved in vasodilation.
PMID- 10666035
TI - Smokeless tobacco potentiates VIP-induced DNA synthesis and inactivates NEP 24.11
in oral keratinocytes.
AB - The purpose of this study was to determine whether exposure of cultured
chemically transformed hamster oral keratinocytes (HCPC-1) to an aqueous extract
of smokeless tobacco (STE) potentiates DNA synthesis elicited by vasoactive
intestinal peptide (VIP), an autocrine neuropeptide, and, if so, whether this
response is associated with inactivation of neutral endopeptidase 24.11 (NEP 24.
11), an ectoenzyme that cleaves and inactivates VIP very effectively, in these
cells. I found that STE and VIP each elicited a modest, albeit significant,
increase in DNA synthesis in cultured HCPC-1 cells (P < 0.05). However,
incubation of HCPC-1 cells with STE together with VIP evoked a significant,
concentration- dependent increase in DNA synthesis that was mediated by VIP
receptors. The effects of STE and VIP were synergistic. Maximal response was
observed after a 48-h incubation. STE significantly attenuated NEP 24.11 activity
in HCPC-1 cells at a time when VIP-induced DNA synthesis was maximal.
Collectively, these data indicate that STE potentiates VIP-induced DNA synthesis
in cultured oral keratinocytes, and that this response is temporally related to
STE-induced inactivation of NEP 24.11 in these cells. I suggest that NEP 24.11
modulates the mitogenic effects of smokeless tobacco in the oral epithelium, in
part, by inactivating VIP.
PMID- 10666036
TI - RPTPmu and protein tyrosine phosphorylation regulate K(+) channel mRNA expression
in adult cardiac myocytes.
AB - Previously, we reported that cell-cell contact regulates K(+) channel mRNA
expression in cultured adult rat cardiac myocytes. Here we show that exposing
cardiac myocytes to tyrosine kinase inhibitors (genistein, tyrphostin A25), but
not inactive analogs, prevents downregulation of Kv1.5 mRNA and upregulation of
Kv4.2 mRNA normally observed when they are cultured under low-density conditions.
Furthermore, cardiac myocytes cocultured with cells that endogenously (Mv 1 Lu)
or heterologously (Chinese hamster ovary cells) express the receptor-type protein
tyrosine phosphatase mu (RPTPmu) display Kv1.5 mRNA levels paralleling that which
was observed in myocytes cultured under high-density conditions and in intact
tissue. In contrast, myocytes cocultured with control cells failed to produce
this response. Finally, it is shown that Kv4.2 mRNA expression is unaffected by
RPTPmu. These findings reveal that multiple tyrosine phosphorylation-dependent
mechanisms control cardiac myocyte K(+) channel genes. Furthermore, we conclude
that RPTPmu specifically regulates cardiac myocyte Kv1.5 mRNA expression. Thus
this receptor protein tyrosine phosphatase may be important in responses to
pathological conditions associated with the loss of cell-cell interactions in the
heart.
PMID- 10666037
TI - Pinacidil suppresses contractility and preserves energy but glibenclamide has no
effect during muscle fatigue.
AB - The effects of 10 microM glibenclamide, an ATP-sensitive K(+) (K(ATP)) channel
blocker, and 100 microM pinacidil, a channel opener, were studied to determine
how the K(ATP) channel affects mouse extensor digitorum longus (EDL) and soleus
muscle during fatigue. Fatigue was elicited with 200-ms-long tetanic contractions
every second. Glibenclamide did not affect rate and extent of fatigue, force
recovery, or (86)Rb(+) fractional loss. The only effects of glibenclamide during
fatigue were: an increase in resting tension (EDL and soleus), a depolarization
of the cell membrane, a prolongation of the repolarization phase of action
potential, and a greater ATP depletion in soleus. Pinacidil, on the other hand,
increased the rate but not the extent of fatigue, abolished the normal increase
in resting tension during fatigue, enhanced force recovery, and increased
(86)Rb(+) fractional loss in both the EDL and soleus. During fatigue, the
decreases in ATP and phosphocreatine of soleus muscle were less in the presence
of pinacidil. The glibenclamide effects suggest that fatigue, elicited with
intermittent contractions, activates few K(ATP) channels that affect resting
tension and membrane potentials but not tetanic force, whereas opening the
channel with pinacidil causes a faster decrease in tetanic force, improves force
recovery, and helps in preserving energy.
PMID- 10666038
TI - PKA holoenzyme is functionally coupled to CFTR by AKAPs.
AB - Cystic fibrosis transmembrane regulator (CFTR) is reported to be preferentially
regulated by membrane-bound protein kinase A (PKAII). We tested for close
physical and functional association of PKA with CFTR in inside-out membrane
patches excised from Calu-3 cells. In the presence of MgATP, 8-(4
chlorophenylthio)adenosine 3',5'-cyclic monophosphate (CPT-cAMP) increased the
product of CFTR channel number and open probability (from 0.36 +/- 0.12 to 1.23
+/- 0.57, n = 20, P < 0.0025), and this stimulation was abolished by PKI. Thus
Calu-3 membrane isolated from cells retains PKA holoenzyme that is functionally
coupled to CFTR. PKAII is anchored at specific subcellular sites by A kinase
anchoring proteins (AKAPs). Exposure of excised patches to HT-31, a peptide that
disrupts the association of PKAII and AKAPs, prevented CPT-cAMP stimulation of
CFTR. Therefore, PKA holoenzyme in isolated membrane patches is bound to AKAPs.
In whole cell voltage-clamp studies, intracellular dialysis of Calu-3 cells with
HT-31 blocked the activation of CFTR by extracellular adenosine. These results
suggest that AKAPs mediate PKA compartmentalization with CFTR and are required
for activation of CFTR by physiological regulators.
PMID- 10666039
TI - Ca(2+) activation of heart mitochondrial oxidative phosphorylation: role of the
F(0)/F(1)-ATPase.
AB - Ca(2+) has been postulated as a cytosolic second messenger in the regulation of
cardiac oxidative phosphorylation. This hypothesis draws support from the well
known effects of Ca(2+) on muscle activity, which is stimulated in parallel with
the Ca(2+)-sensitive dehydrogenases (CaDH). The effects of Ca(2+) on oxidative
phosphorylation were further investigated in isolated porcine heart mitochondria
at the level of metabolic driving force (NADH or Deltapsi) and ATP production
rates (flow). The resulting force-flow (F-F) relationships permitted the analysis
of Ca(2+) effects on several putative control points within oxidative
phosphorylation, simultaneously. The F-F relationships resulting from additions
of carbon substrates alone provided a model of pure CaDH activation. Comparing
this curve with variable Ca(2+) concentration ([Ca(2+)]) effects revealed an
approximate twofold higher ATP production rate than could be explained by a
simple increase in NADH or Deltapsi via CaDH activation. The half-maximal effect
of Ca(2+ )at state 3 was 157 nM and was completely inhibited by ruthenium red (1
microM), indicating matrix dependence of the Ca(2+) effect. Arsenate was used as
a probe to differentiate between F(0)/F(1)-ATPase and adenylate translocase
activity by a futile recycling of ADP-arsenate within the matrix, catalyzed by
the F(0)/F(1)-ATPase. Ca(2+) increased the ADP arsenylation rate more than
twofold, suggesting a direct effect on the F(0)/F(1)-ATPase. These results
suggest that Ca(2+) activates cardiac aerobic respiration at the level of both
the CaDH and F(0)/F(1)-ATPase. This type of parallel control of both intermediary
metabolism and ATP synthesis may provide a mechanism of altering ATP production
rates with minimal changes in the high-energy intermediates as observed in vivo.
PMID- 10666040
TI - cAMP-activated anion conductance is associated with expression of CFTR in
neonatal mouse cardiac myocytes.
AB - In this study, patch-clamp techniques were applied to cultured neonatal mouse
cardiac myocytes (NMCM) to assess the contribution of cAMP stimulation to the
anion permeability in this cell model. Addition of either isoproterenol or a
cocktail to raise intracellular cAMP increased the whole cell currents of NMCM.
The cAMP-dependent conductance was largely anionic, as determined under
asymmetrical (low intracellular) Cl(-) conditions and symmetrical Cl(-) in the
presence of various counterions, including Na(+), Mg(2+), Cs(+), and N-methyl-D
glucamine. Furthermore, the cAMP-stimulated conductance was also permeable to
ATP. The cAMP-activated currents were inhibited by diphenylamine-2-carboxylate,
glibenclamide, and an anti-cystic fibrosis transmembrane conductance regulator
(CFTR) monoclonal antibody. The anti-CFTR monoclonal antibody failed, however, to
inhibit an osmotically activated anion conductance, indicating that CFTR is not
linked to osmotically stimulated currents in this cell model. Immunodetection
studies of both neonatal mouse heart tissue and cultured NMCM revealed that CFTR
is expressed in these preparations. The implication of CFTR in the cAMP
stimulated Cl(-)- and ATP-permeable conductance was further verified with NMCM of
CFTR knockout mice [cftr(-/-)] in which cAMP stimulation was without effect on
the whole cell currents. In addition, stimulation with protein kinase A and ATP
induced Cl(-)-permeable single-channel activity in excised, inside-out patches
from control, but not cftr(-/-) NMCM. The data in this report indicate that cAMP
stimulation of NMCM activates an anion-permeable conductance with functional
properties similar to those expected for CFTR, thus suggesting that CFTR may be
responsible for the cAMP-activated conductance. CFTR may thus contribute to the
permeation and/or regulation of Cl(-)- and ATP-permeable pathways in the
developing heart.
PMID- 10666041
TI - Lessons from genetically engineered animal models VIII. Absorption and secretion
of ions in the gastrointestinal tract.
AB - Absorption and secretion of ions in gastrointestinal and other epithelial tissues
require the concerted activities of ion pumps, channels, symporters, and
exchangers, which operate in coupled systems to mediate transepithelial
transport. Our understanding of the identities, membrane locations, and
biochemical activities of epithelial ion transporters has advanced significantly
in recent years, but major gaps and uncertainties remain in our understanding of
their physiological functions. Increasingly, this problem is being addressed by
the analysis of mutant mouse models developed by gene targeting. In this review,
we discuss gene knockout studies of the secretory isoform of the Na(+)-K(+)-2Cl(
) cotransporter, isoforms 1, 2, and 3 of the Na(+)/H(+) exchanger, and the
colonic H(+)-K(+)-ATPase. This approach is leading to a clearer understanding of
the functions of these transporters in the living animal.
PMID- 10666042
TI - Nutrient tasting and signaling mechanisms in the gut V. Mechanisms of immunologic
sensation of intestinal contents.
AB - Immune perception of intestinal contents reflects a functional dualism with
systemic hyporesponsiveness to dietary antigens and resident microflora (oral
tolerance) and active immune responses to mucosal pathogens. This facilitates
optimal absorption of dietary nutrients while conserving immunologic resources
for episodic pathogenic challenge. Discrimination between dangerous and harmless
antigens within the enteric lumen requires continual sampling of the
microenvironment by multiple potential pathways, innate and adaptive recognition
mechanisms, bidirectional lymphoepithelial signaling, and rigorous control of
effector responses. Errors in these processes disrupt mucosal homeostasis and are
associated with food hypersensitivity and mucosal inflammation. Mechanisms of
mucosal immune perception and handling of dietary proteins and other antigens
have several practical and theoretical implications including vaccine design,
therapy of systemic autoimmunity, and alteration of enteric flora with
probiotics.
PMID- 10666043
TI - NHE1, NHE2, and NHE3 contribute to regulation of intracellular pH in murine
duodenal epithelial cells.
AB - Na(+)/H(+)-exchangers (NHE) mediate acid extrusion from duodenal epithelial
cells, but the isoforms involved have not previously been determined. Thus we
investigated 1) the contribution of Na(+)-dependent processes to acid extrusion,
2) sensitivity to Na(+)/H(+) exchange inhibitors, and 3) molecular expression of
NHE isoforms. By fluorescence spectroscopy the recovery of intracellular pH
(pH(i)) was measured on suspensions of isolated acidified murine duodenal
epithelial cells loaded with 2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein.
Expression of NHE isoforms was studied by RT-PCR and Western blot analysis.
Reduction of extracellular Na(+) concentration ([Na(+)](o)) during pH(i) recovery
decreased H(+) efflux to minimally 12.5% of control with a relatively high
apparent Michaelis constant for extracellular Na(+). The Na(+)/H(+) exchange
inhibitors ethylisopropylamiloride and amiloride inhibited H(+) efflux maximally
by 57 and 80%, respectively. NHE1, NHE2, and NHE3 were expressed at the mRNA
level (RT-PCR) as well as at the protein level (Western blot analysis). On the
basis of the effects of low [Na(+)](o) and inhibitors we propose that acid
extrusion in duodenal epithelial cells involves Na(+)/H(+) exchange by isoforms
NHE1, NHE2, and NHE3.
PMID- 10666044
TI - Genistein augments prostaglandin-induced recovery of barrier function in ischemia
injured porcine ileum.
AB - We have previously shown that PGE(2) enhances recovery of transmucosal resistance
(R) in ischemia-injured porcine ileum via a mechanism involving chloride
secretion. Because the tyrosine kinase inhibitor genistein amplifies cAMP-induced
Cl(-) secretion, we postulated that genistein would augment PGE(2)-induced
recovery of R. Porcine ileum subjected to 45 min of ischemia was mounted in
Ussing chambers, and R and mucosal-to-serosal fluxes of [(3)H]N-formyl-methionyl
leucyl phenylalanine (FMLP) and [(3)H]mannitol were monitored as indicators of
recovery of barrier function. Treatment with genistein (10(-4) M) and PGE(2) (10(
6) M) resulted in synergistic elevations in R and additive reductions in mucosal
to-serosal fluxes of [(3)H]FMLP and [(3)H]mannitol, whereas treatment with
genistein alone had no effect. Treatment of injured tissues with genistein and
either 8-bromo-cAMP (10(-4) M) or cGMP (10(-4) M) resulted in synergistic
increases in R. However, treatment of tissues with genistein and the protein
kinase C (PKC) agonist phorbol myristate acetate (10(-5)-10(-6) M) had no effect
on R. Genistein augments recovery of R in the presence of cAMP or cGMP but not in
the presence of PKC agonists.
PMID- 10666045
TI - Glucocorticoids and dietary iron regulate postnatal intestinal heavy and light
ferritin expression in rats.
AB - To cope with increasing dietary iron exposure, the intestinal epithelium of
weaning rats must control intracellular labile iron pools. Intestinal expression
of heavy (H) and light (L) ferritin subunits during early weaning and after
cortisone administration and/or iron feeding was investigated. Changes in H and L
ferritin gene expression were determined by nuclear runoff transcriptional assay,
Northern blot analysis, and metabolic labeling of protein synthesis. H ferritin
mRNA levels did not change between days 12 and 15, doubled on day 18, and tripled
on day 24. L ferritin mRNA was reduced by 50% on days 18 and 24. The protein
level of the H and L subunits paralleled the change in mRNAs. Cortisone treatment
on day 12 induced a precocious increase of H and decrease of L mRNA expression on
day 15. Nuclear runoff assays showed that cortisone did not change H and reduced
L ferritin gene transcription. The increased level of H mRNA by cortisone was not
translated, unless the rats were fed an iron-fortified diet, which reduced iron
regulatory protein activity and stimulated a three- to sixfold increase of
ferritin synthesis. Thus changes in intestinal H and L ferritin expression in
weaning rats are modulated by glucocorticoids and iron; the former stabilizes H
mRNA and suppresses L ferritin gene transcription, and the latter derepresses
translation of ferritin mRNA.
PMID- 10666046
TI - Release of osmolytes induced by phagocytosis and hormones in rat liver.
AB - Betaine, taurine, and inositol participate as osmolytes in liver cell volume
homeostasis and interfere with cell function. In this study we investigated
whether osmolytes are also released from the intact liver independent of
osmolarity changes. In the perfused rat liver, phagocytosis of carbon particles
led to a four- to fivefold stimulation of taurine efflux into the effluent
perfusate above basal release rates. This taurine release was inhibited by 70-80%
by the anion exchange inhibitor DIDS or by pretreatment of the rats with
gadolinium chloride. Administration of vasopressin, cAMP, extracellular ATP, and
glucagon also increased release of betaine and/or taurine, whereas insulin,
extracellular UTP, and adenosine were without effect. In isolated liver cells, it
was shown that parenchymal cells and sinusoidal endothelial cells, but not
Kupffer cells and hepatic stellate cells, release osmolytes upon hormone
stimulation. This may be caused by a lack of hormone receptor expression in these
cells, because single-cell fluorescence measurements revealed an increase of
intracellular calcium concentration in response to vasopressin and glucagon in
parenchymal cells and sinusoidal endothelial cells but not in Kupffer cells and
hepatic stellate cells. The data show that Kupffer cells release osmolytes during
phagocytosis via DIDS-sensitive anion channels. This mechanism may be used to
compensate for the increase in cell volume induced by the ingestion of
phagocytosable material. The physiological significance of hormone-induced
osmolyte release remains to be evaluated.
PMID- 10666047
TI - Impairment of Ca(2+) mobilization in circular muscle cells of the inflamed colon.
AB - This study investigated whether inflammation modulates the mobilization of Ca(2+)
in canine colonic circular muscle cells. The contractile response of single cells
from the inflamed colon was significantly suppressed in response to ACh, KCl, and
BAY K8644. Methoxyverapamil and reduction in extracellular Ca(2+) concentration
dose-dependently blocked the response in both normal and inflamed cells. The
increase in intracellular Ca(2+) concentration in response to ACh and KCl was
significantly reduced in the inflamed cells. However, Ca(2+) efflux from the
ryanodine- and inositol 1,4, 5-trisphosphate (IP(3))-sensitive stores, as well as
the decrease of cell length in response to ryanodine and IP(3), were not
affected. Heparin significantly blocked Ca(2+) efflux and contraction in response
to ACh in both conditions. ACh-stimulated accumulation of IP(3) and the binding
of [(3)H]ryanodine to its receptors were not altered by inflammation. Ruthenium
red partially inhibited the response to ACh in normal and inflamed states. We
conclude that the canine colonic circular muscle cells utilize Ca(2+) influx
through L-type channels as well as Ca(2+) release from the ryanodine- and IP(3)
sensitive stores to contract. Inflammation impairs Ca(2+) influx through L-type
channels, but it may not affect intracellular Ca(2+) release. The impairment of
Ca(2+) influx may contribute to the suppression of circular muscle contractility
in the inflamed state.
PMID- 10666048
TI - Ionizing radiation induces iNOS-mediated epithelial dysfunction in the absence of
an inflammatory response.
AB - Ionizing radiation induces intestinal epithelial hyporesponsiveness to
secretagogues through an unknown mechanism. We investigated the role of the
inducible isoform of nitric oxide (NO) synthase (iNOS)-derived NO in radiation
induced hyporesponsiveness. C57BL/6 mice were sham treated or exposed to 10-Gy
gamma-radiation and were studied 3 days later. Tissues were mounted in Ussing
type diffusion chambers to assess chloride secretion in response to electrical
field stimulation (EFS) and forskolin (10 microM). Transport studies were also
repeated in iNOS-deficient mice. White blood cell counts were significantly lower
in irradiated mice, and there was no inflammatory response as shown by
myeloperoxidase activity and histological assessment. iNOS mRNA levels and
nitrate/nitrite concentrations were significantly elevated in irradiated colons.
iNOS immunoreactivity localized to the epithelium. Colons from irradiated wild
type, but not iNOS-deficient, mice exhibited a significant reduction in the
responsiveness of the tissue to EFS and forskolin. The hyporesponsiveness was
reversed by L-N(6)-(1-iminoethyl)lysine, 1400W, and dexamethasone treatments.
iNOS-derived NO mediates colonic hyporesponsiveness 3 days after irradiation in
the mouse in the absence of an inflammatory response.
PMID- 10666049
TI - Defect of receptor-G protein coupling in human gallbladder with cholesterol
stones.
AB - Human gallbladders with cholesterol stones (ChS) exhibit an impaired muscle
contraction and relaxation and a lower CCK receptor-binding capacity compared
with those with pigment stones (PS). This study was designed to determine whether
there is an abnormal receptor-G protein coupling in human gallbladders with ChS
using (35)S-labeled guanosine 5'-O-(3-thiotriphosphate) ([(35)S]GTPgammaS)
binding, (125)I-labeled CCK-8 autoradiography, immunoblotting, and G protein
quantitation. CCK and vasoactive intestinal peptide caused significant increases
in [(35)S]GTPgammaS binding to Galpha(i-3) and G(s)alpha, respectively. The
binding was lower in ChS than in PS (P < 0.01). The reduced [(35)S]GTPgammaS
binding in ChS was normalized after the muscles were treated with cholesterol
free liposomes (P < 0.01). Autoradiography and immunoblots showed a decreased
optical density (OD) for CCK receptors, an even lower OD value for receptor-G
protein coupling, and a higher OD for uncoupled receptors or Galpha(i-3) protein
in ChS compared with PS (P < 0.001). G protein quantitation also showed that
there were no significant differences in the Galpha(i-3) and G(s)alpha content in
ChS and PS. We conclude that, in addition to an impaired CCK receptor-binding
capacity, there is a defect in receptor-G protein coupling in muscle cells from
gallbladder with ChS. These changes may be normalized after removal of excess
cholesterol from the plasma membrane.
PMID- 10666050
TI - Inflammation-induced impairment of enteric nerve function in nematode-infected
mice is macrophage dependent.
AB - Trichinella spiralis infection in rodents is associated with suppression of ACh
release from myenteric plexus that can be mimicked by macrophage-derived
cytokines. We verified the presence of a macrophage infiltrate in the intestine
during T. spiralis infection and determined the extent to which this cell type is
responsible for the neural changes. C57BL/6 mice were infected with 375 T.
spiralis larvae by gavage, and the presence of macrophages (F4/80 positive) in
the jejunum was determined immunohistochemically. In another experiment, infected
mice were treated intravenously with liposomes containing dichloromethylene
diphosphonate (clodronate, Cl(2)MDP), which causes apoptosis of macrophages, and
killed at postinfection day 6, and jejunal tissues were evaluated for the
presence of F4/80-positive cells and for [(3)H]ACh release from the myenteric
plexus. Infection caused an infiltration of F4/80-positive cells into the
intestinal mucosa, muscle layers, and myenteric plexus region and a significant
suppression of ACh release (50%). Depletion of F4/80-positive macrophages using
Cl(2)MDP-containing liposomes prevented the suppression in [(3)H]ACh release,
identifying macrophages as the cell type involved in the functional impairment of
enteric cholinergic nerves.
PMID- 10666051
TI - Inhibition of rat colon tumors by sulindac and sulindac sulfone is independent of
K-ras (codon 12) mutation.
AB - Nonsteroidal anti-inflammatory drug (NSAID) use reduces the risk of colorectal
cancer by 40-50%. Previous studies suggest that effective inhibition of
colorectal cancer by NSAIDs may be dependent on the presence or absence of a K
ras mutation. This study was aimed at determining the relationship between
inhibition of colorectal cancer by sulindac and sulindac sulfone and the presence
of activating K-ras mutations in the 1,2-dimethylhydrazine dihydrochloride rat
model. Sulindac (20 mg x kg(-1) x day(-1)), sulindac sulfone (40 mg x kg(-1) x
day(-1)), or vehicle was administered orally to male Sprague-Dawley rats for a 4
wk period beginning 20 wk after tumor induction. Tumor number and volume were
measured before treatment by laparotomy and colonoscopy and again after
treatment. Sulindac and sulindac sulfone treatment significantly reduced the
number and volume of colorectal tumors compared with control rats. For K-ras
(codon 12) mutation detection, frozen tumor tissue was collected at the endpoint.
We found K-ras codon 12 mutations in 11 of 21 (52%) control tumors. The
proportion of tumors with K-ras mutations in the sulindac-treated group [5 of 8
(62%); odds ratio = 1.51 (95% confidence interval = 0.29, 8.33)] and the
proportion of sulindac sulfone-treated tumors [9 of 14 (64%); odds ratio = 1.63
(95% confidence interval = 0.41, 6.66)] were not significantly different from
controls. Tumor inhibition did not correlate with K-ras (codon 12) mutation
status, which suggests that the mechanism of inhibition of rat colorectal cancer
by sulindac and sulindac sulfone is independent of K-ras mutation.
PMID- 10666052
TI - Properties of synaptic inputs from myenteric neurons innervating submucosal S
neurons in guinea pig ileum.
AB - This study examined synaptic inputs from myenteric neurons innervating submucosal
neurons. Intracellular recordings were obtained from submucosal S neurons in
guinea pig ileal preparations in vitro, and synaptic inputs were recorded in
response to electrical stimulation of exposed myenteric plexus. Most S neurons
received synaptic inputs [>80% fast (f) excitatory postsynaptic potentials
(EPSP), >30% slow (s) EPSPs] from the myenteric plexus. Synaptic potentials were
recorded significant distances aboral (fEPSPs, 25 mm; sEPSPs, 10 mm) but not oral
to the stimulating site. When preparations were studied in a double-chamber bath
that chemically isolated the stimulating "myenteric chamber" from the recording
side "submucosal chamber," all fEPSPs were blocked by hexamethonium in the
submucosal chamber, but not by a combination of nicotinic, purinergic, and 5
hydroxytryptamine-3 receptor antagonists in the myenteric chamber. In 15% of
cells, a stimulus train elicited prolonged bursts of fEPSPs (>30 s duration) that
were blocked by hexamethonium. These findings suggest that most submucosal S
neurons receive synaptic inputs from predominantly anally projecting myenteric
neurons. These inputs are poised to coordinate intestinal motility and secretion.
PMID- 10666053
TI - Evidence for a peripheral mechanism of esophagocrural diaphragm inhibitory reflex
in cats.
AB - The esophagogastric junction (EGJ) is guarded by two sphincters, a smooth muscle
lower esophageal sphincter (LES) and a skeletal muscle crural diaphragm. These
two sphincters relax simultaneously under certain physiological conditions, i.e.,
swallowing, belching, vomiting, transient LES relaxation, and esophageal
distension. Esophageal distension-induced crural diaphragm relaxation is mediated
through vagal afferents that are thought to exert inhibitory influence on the
central mechanism (brain stem) of crural diaphragm contraction. We conducted
studies in 10 cats to determine whether a mechanism of crural diaphragm
relaxation was located at the level of the neuromuscular junction and/or muscle.
Stimulation of the crural diaphragm neuromuscular junction through 1) the
electrodes implanted in the muscle and 2) the bilateral phrenic nerve resulted in
an increase in EGJ pressure. Nicotinic receptor blockade (pancuronium, 0.2 mg/kg)
abolished the EGJ pressure increase caused by electrical stimulation of the
neuromuscular junction. Esophageal distension and bolus-induced secondary
esophageal peristalsis caused relaxation of the EGJ during the stimulation of the
neuromuscular junction. Bilateral phrenicotomy and vagotomy had no influence on
this relaxation. These data suggest the existence of a peripheral mechanism of
crural diaphragm inhibition. This peripheral inhibitory mechanism may reside at
the level of either the neuromuscular junction or the skeletal muscle.
PMID- 10666054
TI - Kir3.1/3.2 encodes an I(KACh)-like current in gastrointestinal myocytes.
AB - Expression of the Kir3 channel subfamily in gastrointestinal (GI) myocytes was
investigated. Members of this K(+) channel subfamily encode G protein-gated
inwardly rectifying K(+) channels (I(KACh)) in other tissues, including the heart
and brain. In the GI tract, I(KACh) could act as a negative feedback mechanism to
temper the muscarinic response mediated primarily through activation of
nonselective cation currents and inhibition of delayed-rectifier conductance.
Kir3 channel subfamily isoforms expressed in GI myocytes were determined by
performing RT-PCR on RNA isolated from canine colon, ileum, duodenum, and jejunum
circular myocytes. Qualitative PCR demonstrated the presence of Kir3.1 and Kir3.2
transcripts in all smooth muscle cell preparations examined. Transcripts for
Kir3.3 and Kir3.4 were not detected in the same preparations. Semiquantitative
PCR showed similar transcriptional levels of Kir3.1 and Kir3.2 relative to beta
actin expression in the various GI preparations. Full-length cDNAs for Kir3.1 and
Kir3.2 were cloned from murine colonic smooth muscle RNA and coexpressed in
Xenopus oocytes with human muscarinic type 2 receptor. Superfusion of oocytes
with ACh (10 microM) reversibly activated a Ba(2+)-sensitive and inwardly
rectifying K(+) current. Immunohistochemistry using Kir3.1- and Kir3.2-specific
antibodies demonstrated channel expression in circular and longitudinal smooth
muscle cells. We conclude that an I(KACh) current is expressed in GI myocytes
encoded by Kir3.1/3.2 heterotetramers.
PMID- 10666055
TI - Propagation of individual spikes as "patches" of activation in isolated feline
duodenum.
AB - Asynchrony of spikes has made it difficult to study the spatial and temporal
behavior of spikes in the gastrointestinal system. By simultaneously recording
from a large number of closely spaced electrodes, we investigated the propagation
of individual spikes. Recordings were performed from the serosal surface of the
isolated feline duodenum at 240 sites simultaneously. Analysis of the tracings
made it possible to reconstruct the propagation of individual spikes. Spikes
propagate in the longitudinal and circumferential directions in self-limiting
areas or "patches." Conduction within patches may occur in the orad or aborad
direction irrespective of the direction of the slow wave. Most of the patches are
smaller (<40 mm(2)), although inhomogeneous activation by the preceding slow wave
may increase their size. Stimulation by ACh, TTX, or tetraethylammonium does not
affect the average patch size but does increase significantly their number and
distribution in the duodenum [from 26% (control) to 56%, 61%, and 72%,
respectively]. In conclusion, individual spikes activate limited areas or patches
in the small intestine, and pharmacological stimulation increases the number and
distribution of these patches. In the small intestine, this pattern of activation
would induce localized contractions. Contraction could be modulated by the size,
number, and distribution of spike patches.
PMID- 10666056
TI - Syncollin is differentially expressed in rat proximal small intestine and
regulated by feeding behavior.
AB - Gradients of gene expression are maintained along the proximal-distal axis of the
mammalian small intestine despite a continuously regenerating epithelium. To
study the molecular mechanisms responsible for this phenomenon, we utilized a
subtractive hybridization strategy to isolate genes differentially expressed in
the duodenum but not ileum. We isolated and sequenced 15 clones. The clones were
fragments of genes encoding lipases, proteases, and an esterase. A novel clone
was characterized and subsequently shown to encode syncollin, a secretory granule
protein that binds to syntaxin in a calcium-sensitive manner. RT-PCR and S1
nuclease protection assay were used to clarify the 5'-end of syncollin. Syncollin
was expressed in the rat pancreas, spleen, duodenum, and colon. In situ
hybridization localized syncollin expression in the pancreas to acinar cells and
in the duodenum to villus epithelial cells.
PMID- 10666057
TI - c-Myb modulates transcription of the alpha-smooth muscle actin gene in activated
hepatic stellate cells.
AB - Expression of alpha-smooth muscle actin (alpha-SMA) defines the phenotype of
activated (myofibroblastic) hepatic stellate cells. These cells, but not
quiescent stellate cells, have a high level of alpha-SMA and c-Myb expression, as
well as increased c-Myb-binding activities to the proximal alpha-SMA E box.
Therefore, we analyzed the role of c-Myb in alpha-SMA transcription and stellate
cell activation. Activated primary rat stellate cells displayed a high expression
of the -724 and -271 alpha-SMA/luciferase (LUC) chimeric genes, which contain c
Myb binding sites (-223/-216 bp). Alpha-SMA/LUC minigenes with mutation (-219/
217 bp), truncation (-224 bp), or deletion (-191 bp) of the c-Myb binding site
were not efficiently transcribed. Transfection of wild-type c-Myb into quiescent
stellate cells, which do not express endogenous c-Myb, induced a approximately 10
fold stimulation of -724 alpha-SMA/LUC expression. Conversely, expression of
either a dominant-negative c-Myb basic domain mutant (Cys(43) --> Asp) or a c-Myb
antisense RNA blocked transcription from the -724 alpha-SMA/LUC or -271 alpha
SMA/LUC in activated cells. Moreover, transfection of c-myb antisense, but not
sense, RNA inhibited both expression of the endogenous alpha-SMA gene and
stellate cell activation, whereas transfection of c-myb stimulated alpha-SMA
expression in quiescent stellate cells. These findings suggest that c-Myb
modulates the activation of stellate cells and that integrity of the redox sensor
Cys(43) in c-Myb is required for this effect.
PMID- 10666058
TI - Relationships between spatial patterns of colonic pressure and individual
movements of content.
AB - The aim of this study was to examine the relationship between colonic pressure
waves and movement of content. In 11 healthy subjects, pressures were recorded at
10-cm intervals from cecum to rectum for 32 h. In six subjects, transit was
simultaneously measured for 8 h after direct cecal instillation of 1.5 mCi of
(99m)Tc sulfur colloid. Thirty-two percent of isotope movements were related to
nonpropagating activity and twenty-eight percent to propagating sequences. The
extent of isotope movement related to propagating sequences (25.1 +/- 2.1 cm) was
greater than that due to nonpropagating activity (12.8 +/- 0.7 cm; P = 0.0001).
Propagating sequences originated significantly more frequently (P = 0.004) and
propagated further (P = 0.0006) in the proximal compared with the distal colon.
Only 36% of propagating sequences were propulsive of content, and compared with
nonpropulsive sequences, these propagated further (41 +/- 6 vs. 27 +/- 2 cm; P <
0.05) and had a higher probability of originating proximally (P = 0.0003), a
higher pressure wave amplitude (50 +/- 5 vs. 34 +/- 4 mmHg; P = 0.0001), and
slower velocity (2.2 +/- 0.3 vs. 3.6 +/- 0.47 cm/s; P = 0.02). We conclude that
most movements of colonic content are related to pressure waves. There is marked
regional variation in the prevalence, velocity, and extent of propagation of
propagating pressure wave sequences, which are an important mechanism for
transporting content over long distances. The effectiveness of transport by a
propagating sequence is influenced by its site of origin, amplitude, and
velocity.
PMID- 10666059
TI - Mechanism of preserved positive lusitropy by cAMP-dependent drugs in heart
failure.
AB - In tachycardia-induced heart failure (HF), positive lusitropic effects of
milrinone or dobutamine were assessed by evaluating the time constant of left
ventricular (LV) pressure decay (tau) and Ca(2+)-ATPase activity of the
sarcoplasmic reticulum (SR). The peak value of the positive first derivative of
LV pressure (+dP/dt) was less increased, either by dobutamine (2-10 microg x kg(
1) x min(-1)) or by milrinone (4-20 microg/kg), in HF than in control (P < 0.05),
whereas tau was shortened to an extent similar to that in control with dobutamine
[P = not significant (NS)] and to an even greater extent with milrinone (P <
0.05). Ca(2+)-ATPase activity increased similarly in HF and control with
dobutamine (1 microM; +11% in HF vs. +12% in control, P = NS), whereas it
increased more with milrinone (1 microM; +19% in HF vs. +11% in control, P <
0.05). Ca(2+)-ATPase activity-cAMP relationships were shifted to the left by
milrinone or dobutamine in HF compared with control. Thus, in HF, the sensitivity
of Ca(2+)-ATPase activity to cAMP was increased on addition of cAMP-dependent
inotropic agents, contributing to the preservation of positive lusitropy.
PMID- 10666060
TI - Stroke volume during exercise: interaction of environment and hydration.
AB - Euhydrated and dehydrated subjects exercised in a hot and a cold environment with
our aim to identify factors that relate to reductions in stroke volume (SV). We
hypothesized that reductions in SV with heat stress are related to the
interaction of several factors rather than the effect of elevated skin blood
flow. Eight male endurance-trained cyclists [maximal O(2) consumption (VO(2 max))
4.5 +/- 0.1 l/min; means +/- SE] cycled for 30 min (72% VO(2 max)) in the heat
(H; 35 degrees C) or the cold (C; 8 degrees C) when euhydrated or dehydrated by
1.5, 3.0, or 4.2% of their body weight. When euhydrated, SV and esophageal
temperature (T(es) 38. 2-38.3 degrees C) were similar in H and C, whereas skin
blood flow was much higher in H vs. C (365 +/- 64% higher; P < 0.05). With each
1% body weight loss, SV declined 6.4 +/- 1.3 ml (4.8%) in H and 3.4 +/- 0.4 ml
(2.5%) in C, whereas T(es) increased 0.21 +/- 0.02 and 0. 10 +/- 0.02 degrees C
in H and C, respectively (P < 0.05). However, reductions in SV were not
associated with increases in skin blood flow. The reduced SV was highly
associated with increased heart rate and reduced blood volume in both H (R =
0.96; P < 0.01) and C (R = 0. 85; P < 0.01). In conclusion, these results suggest
that SV is maintained in trained subjects during exercise in euhydrated
conditions despite large differences in skin blood flow. Furthermore, the
lowering of SV with dehydration appears largely related to increases in heart
rate and reductions in blood volume.
PMID- 10666061
TI - Chronic hypercapnia inhibits hypoxic pulmonary vascular remodeling.
AB - Chronic hypercapnia is commonly found in patients with severe hypoxic lung
disease and is associated with a greater elevation of pulmonary arterial pressure
than that due to hypoxia alone. We hypothesized that hypercapnia worsens hypoxic
pulmonary hypertension by augmenting pulmonary vascular remodeling and hypoxic
pulmonary vasoconstriction (HPV). Rats were exposed to chronic hypoxia
[inspiratory O(2) fraction (FI(O(2))) = 0.10], chronic hypercapnia (inspiratory
CO(2) fraction = 0.10), hypoxia-hypercapnia (FI(O(2)) = 0.10, inspiratory CO(2)
fraction = 0.10), or room air. After 1 and 3 wk of exposure, muscularization of
resistance blood vessels and hypoxia-induced hematocrit elevation were
significantly inhibited in hypoxia-hypercapnia compared with hypoxia alone (P <
0.001, ANOVA). Right ventricular hypertrophy was reduced in hypoxia-hypercapnia
compared with hypoxia at 3 wk (P < 0.001, ANOVA). In isolated, ventilated, blood
perfused lungs, basal pulmonary arterial pressure after 1 wk of exposure to
hypoxia (20.1 +/- 1.8 mmHg) was significantly (P < 0.01, ANOVA) elevated compared
with control conditions (12.1 +/- 0.1 mmHg) but was not altered in hypoxia
hypercapnia (13.5 +/- 0.9 mmHg) or hypercapnia (11.8 +/- 1.3 mmHg). HPV (FI(O(2))
= 0.03) was attenuated in hypoxia, hypoxia-hypercapnia, and hypercapnia compared
with control (P < 0.05, ANOVA). Addition of N(omega)-nitro-L-arginine methyl
ester (10(-4) M), which augmented HPV in control, hypoxia, and hypercapnia,
significantly reduced HPV in hypoxia-hypercapnia. Chronic hypoxia caused impaired
endothelium-dependent relaxation in isolated pulmonary arteries, but coexistent
hypercapnia partially protected against this effect. These findings suggest that
coexistent hypercapnia inhibits hypoxia-induced pulmonary vascular remodeling and
right ventricular hypertrophy, reduces HPV, and protects against hypoxia-induced
impairment of endothelial function.
PMID- 10666062
TI - Role of adenosine A(2B) receptors in vasodilation of rat pial artery and cerebral
blood flow autoregulation.
AB - This study was aimed to investigate the underlying mechanism of vasodilation
induced by the activation of A(2B) adenosine receptors in relation to cerebral
blood flow (CBF) autoregulation. Changes in pial arterial diameters were observed
directly through a closed cranial window. N(omega)-nitro-L-arginine methyl ester
(L-NAME, nitric oxide synthase inhibitor) significantly suppressed the
concentration-dependent vasodilations induced by adenosine and 5'-N
ethylcarboxamido-adenosine (NECA) but not the vasodilation by CGS-21680 (A(2A)
receptor agonist). Moreover, NECA-induced vasodilation was suppressed by
alloxazine (1 micromol/l) but not by ZM-241385 (1 micromol/l, A(2A) antagonist),
which suggests mediation by A(2B)- receptor activation. Otherwise, the level of
nitrite/nitrate was concentration dependently increased in the artificial
cerebrospinal fluid (CSF) when adenosine and NECA were suffused over the cortical
surface. L-NAME and alloxazine, but not ZM-241385, largely inhibited their
releases. The lower limit of CBF autoregulation was little affected following
pretreatment with L-NAME or alloxazine. Thus it is suggested that adenosine
induced vasodilation via activation of A(2B)-adenosine receptors of the rat pial
artery is coupled to the production of nitric oxide, which contributes little to
CBF autoregulation.
PMID- 10666063
TI - Transient increases in diameter and [Ca(2+)](i) are not obligatory for myogenic
constriction.
AB - Studies were performed to determine the significance of temporal variation in
vascular smooth muscle Ca(2+) signaling during acute arteriolar myogenic
constriction and, in particular, the importance of the stretch-induced
intracellular Ca(2+) concentration ([Ca(2+)](i)) transient in attaining a steady
state mechanical response. Rat cremaster arterioles (diameter approximately 100
microm) were dissected from surrounding tissues, and vessel segments were
pressurized in the absence of intraluminal flow. For [Ca(2+)](i) measurements,
vessels were loaded with fura 2 and fluorescence emitted by excitation at 340 and
380 nm was measured using video-based image analysis. Ca(2+) and diameter
responses were examined after increases in intravascular pressure were applied as
an acute step increase or a ramp function. Additional studies examined the effect
of longitudinal vessel stretch on [Ca(2+)](i) and arteriolar diameter. Step
increase in intraluminal pressure (from 50 to 120 mmHg) caused biphasic change in
[Ca(2+)](i) and diameter. [Ca(2+)](i) transiently increased to 114.0 +/- 2.0% of
basal levels and subsequently declined to 106.7 +/- 4.4% at steady state.
Diameter initially distended to 125.4 +/- 2.1% of basal levels before
constricting to 71.1 +/- 1.2%. In contrast, when the same pressure increase was
applied as a ramp function (over 5 min) transient vessel distension and transient
increase in [Ca(2+)](i) were prevented, yet at steady state vessels constricted
to 71.3 +/- 2.5%. Longitudinal stretch resulted in a large [Ca(2+)](i) transient
(158 +/- 19% of basal) that returned to baseline despite maintenance of the
stretch stimulus. The data demonstrate that the initial vessel distension
(reflecting myocyte stretch) and associated global [Ca(2+)](i) transient are not
obligatory for myogenic contraction. Thus, although arteriolar smooth muscle
cells are responsive to acute stretch, the resulting changes in myogenic tone may
be more closely related to other mechanical variables such as wall tension.
PMID- 10666064
TI - Functional role of angiotensin II type 1 and 2 receptors in regulation of uterine
blood flow in nonpregnant sheep.
AB - The objective was to determine the receptor subtype of angiotensin II (ANG II)
that is responsible for vasoconstriction in the nonpregnant ovine uterine and
systemic vasculatures. Seven nonpregnant estrogenized ewes with indwelling
uterine artery catheters and flow probes received bolus injections (0.1, 0.3 and
1 microg) of ANG II locally into the uterine artery followed by a systemic
infusion of ANG II at 100 ng x kg(-1) x min(-1) for 10 min to determine uterine
vasoconstrictor responses. Uterine ANG II dose-response curves were repeated
following administration of the ANG II type 2 receptor (AT(2)) antagonist PD
123319 and then repeated again in the presence of an ANG II type 1 receptor
(AT(1)) antagonist L-158809. In a second experiment, designed to investigate the
mechanism of ANG II potentiation that occurred in the presence of AT(2) blockade,
nonestrogenized sheep received a uterine artery infusion of L-158809 (3 mg/min
for 5 min) prior to the infusion of 0.03 microg/min of ANG II for 10 min. ANG II
produced dose-dependent decreases in uterine blood flow (P < 0.03), which were
potentiated in the presence of the AT(2) antagonist (P < 0.02). Addition of the
AT(1) antagonist abolished the uterine vascular responses and blocked ANG II
induced increases in systemic arterial pressure (P < 0.01). Significant uterine
vasodilation (P < 0.01) was noted with AT(1) blockade in the second experiment,
which was reversed by administration of the AT(2) antagonist or by the nitric
oxide synthetase inhibitor N(omega)-nitro-L-arginine methyl ester. We conclude
that the AT(1)-receptors mediate the systemic and uterine vasoconstrictor
responses to ANG II in the nonpregnant ewe. AT(2)-receptor blockade resulted in a
potentiation of the uterine vasoconstrictor response to ANG II, suggesting that
the AT(2)-receptor subtype may modulate uterine vascular responses to ANG II
potentially by release of nitric oxide.
PMID- 10666065
TI - Regulation of myocardial blood flow response to mental stress in healthy
individuals.
AB - Mental stress testing has been proposed as a noninvasive tool to evaluate
endothelium-dependent coronary vasomotion. In patients with coronary artery
disease, mental stress can induce myocardial ischemia. However, even the
determinants of the physiological myocardial blood flow (MBF) response to mental
stress are poorly understood. Twenty-four individuals (12 males/12 females, mean
age 49 +/- 13 yr, range 31-74 yr) with a low likelihood for coronary artery
disease were studied. Serum catecholamines, cardiac work, and MBF (measured
quantitatively with N-13 ammonia and positron emission tomography) were assessed.
During mental stress (arithmetic calculation) MBF increased significantly from
0.70 +/- 0.14 to 0.92 +/- 0.21 ml x min(-1) x g(-1) (P < 0.01). Mental stress
caused significant increases (P < 0.01) in serum epinephrine (26 +/- 16 vs. 42 +/
17 pg/ml), norepinephrine (272 +/- 139 vs. 322 +/- 136 pg/ml), and cardiac work
[rate-pressure product (RPP) 8,011 +/- 1,884 vs. 10,416 +/- 2,711]. Stress
induced changes in cardiac work were correlated with changes in MBF (r = 0.72; P
< 0.01). Multiple-regression analysis revealed stress-induced changes in the RPP
as the only significant (P = 0.0001) predictor for the magnitude of mental stress
induced increases in MBF in healthy individuals. Data from this group of healthy
individuals should prove useful to investigate coronary vasomotion in individuals
at risk for or with documented coronary artery disease.
PMID- 10666066
TI - B(1) and B(2) bradykinin receptors on adventitial fibroblasts of cerebral
arteries are coupled to recombinant eNOS.
AB - Our previous ex vivo and in vivo studies reported that expression of the
recombinant endothelial nitric oxide (NO) synthase (eNOS) gene in adventitial
fibroblasts recovers NO production in arteries without endothelium in response to
bradykinin. The present study was designed to characterize subtypes of bradykinin
receptors on adventitial fibroblasts coupled to the activation of recombinant
eNOS. Endothelium-denuded segments of canine basilar arteries were transduced
with beta-galactosidase (beta-Gal) gene or eNOS gene ex vivo, using a replication
defective adenoviral vector (10(10) plaque-forming units/ml) for 30 min at 37
degrees C. Twenty-four hours later, isometric force recording or cGMP measurement
was carried out. B(1) bradykinin receptor agonist (des-Arg(9)-bradykinin, 10(-10)
10(-8) mol/l) did not significantly affect vascular tone in control or beta-Gal
gene-transduced canine basilar arteries without endothelium. In contrast, this
agonist caused concentration-dependent relaxations in recombinant eNOS gene
transduced arteries without endothelium. Relaxations to B(1) receptor agonist in
the eNOS arteries were abolished by B(1) receptor antagonist (des-Arg(9)
[Leu(8)]bradykinin, 6 x 10(-9) mol/l) but not by B(2) receptor antagonist (Hoe
140, 5 x 10(-8) mol/l). Bradykinin did not significantly alter vascular tone in
control or beta-gal arteries without endothelium, whereas this peptide (10(-11)
10(-8) mol/l) induced concentration-dependent relaxations, as well as an increase
in cGMP formation in endothelium-denuded eNOS-transduced arteries. Stimulatory
effects of bradykinin were prevented in the presence of a B(2) receptor
antagonist but not in the presence of a B(1) receptor antagonist. B(1) and B(2)
receptor antagonists had no effect on relaxations to substance P, confirming the
selectivity of the compounds. Our results suggest that B(1) and B(2) bradykinin
receptors are coupled to activation of recombinant eNOS expressed in adventitial
fibroblasts.
PMID- 10666068
TI - Dynamics of flow, resistance, and intramural vascular volume in canine coronary
circulation.
AB - Varying coronary volume will vary vascular resistance and thereby have an effect
on coronary hemodynamics. Six ventricular septa were isolated from anesthetized
dogs, dispersed in a biaxial stretch apparatus at diastolic stress, and perfused
artificially with an oxygenated perfluorochemical emulsion at maximal
vasodilation. Flow and thickness were measured continuously by an electromagnetic
flow probe and sonomicrometer. Pressure was varied sinusoidally around 30, 50,
and 70 mmHg with an amplitude of 7.5 mmHg; frequencies ranged between 0.015 and 7
Hz. Bode plots of admittance (flow/pressure) and capacitance (scaled
thickness/pressure) were constructed. A two-compartment model was used in which
the resistances vary with volume. Realistic values of microvascular compliance (
approximately 0.3 ml x mmHg(-1) x 100 g(-1)) were found. Values 10 times higher
were then found when resistances were forced to be constant. We concluded that
volume dependence of resistances have to be taken into account when dynamic or
static pressure-flow relations are studied and conceal the effect of a large
intramyocardial compliance on arterial hemodynamics.
PMID- 10666067
TI - Tyrosine phosphorylation modulates arteriolar tone but is not fundamental to
myogenic response.
AB - The present study investigated the role of protein tyrosine phosphorylation in
myogenic responsiveness of rat skeletal muscle arterioles. Arteriolar segments
were cannulated and pressurized without intraluminal flow. All vessels studied
developed spontaneous tone and demonstrated significant myogenic constriction to
step changes in pressure with a resultant increase in myogenic tone over an
intraluminal pressure range of 50-150 mmHg. Step increases in intraluminal
pressure from 50 to 120 mmHg caused a rapid and sustained elevation in
intracellular [Ca(2+)], as measured using fura 2. Vessels with myogenic tone
dilated in response to tyrosine kinase inhibitors genistein (10 or 30 microM) and
tyrphostin A47 (10 or 30 microM) and constricted to the tyrosine phosphatase
inhibitor pervanadate (1 or 10 microM). Despite the dilator effect, myogenic
reactivity was not blocked by the inhibitors. Daidzein (10 microM), a compound
structurally similar to genistein but without tyrosine kinase-inhibiting
activity, did not alter vessel tone or myogenic responses. Preincubation of
arterioles with genistein or tyrphostin A47 did not significantly alter baseline
arteriolar [Ca(2+)], and neither drug reduced the increase in [Ca(2+)] following
an acute increase in intraluminal pressure. Constriction induced by pervanadate
(10 microM) was not accompanied by a significant increase in intracellular
[Ca(2+)], even though removal of extracellular Ca(2+) reversed the constriction.
Examination of smooth muscle tyrosine phosphorylation, using a fluorescent
phosphotyrosine antibody and confocal microscopy, showed that increased
intraluminal pressure resulted in an increase in anti-phosphotyrosine
fluorescence. Because manipulation of tyrosine kinase activity was found to alter
vessel diameter, these data support a role for tyrosine phosphorylation in
modulation of arteriolar tone. However, the results indicate that acute
arteriolar myogenic constriction does not require tyrosine phosphorylation.
PMID- 10666069
TI - VSM growth is stimulated in sympathetic neuron/VSM cocultures: role of TGF-beta2
and endothelin.
AB - Sympathetic nerves are purported to stimulate blood vessel growth. The
mechanism(s) underlying this stimulation has not been determined. With use of an
in vitro coculture model, the present study tests the hypothesis that sympathetic
neurons stimulate the growth of vascular smooth muscle (VSM) and evaluates
potential mechanisms mediating this stimulation. Sympathetic neurons isolated
from superior cervical ganglia (SCG) stimulated the growth of VSM. Growth of VSM
in the presence of SCG (856 +/- 81%) was significantly greater than that in the
absence of SCG (626 +/- 66%, P < 0.05). SCG did not stimulate VSM growth in
transwell cocultures. An antibody that neutralized the activity of transforming
growth factor-beta2 (TGF-beta2) inhibited SCG stimulation of VSM growth in
coculture. SCG stimulation of VSM growth was also inhibited by an endothelin A
receptor antagonist. These data suggest novel mechanisms for sympathetic
modulation of vascular growth that may play a role in the physiological and/or
pathological growth of the vasculature.
PMID- 10666070
TI - Expression of the beta (slow)-isoform of MHC in the adult mouse heart causes
dominant-negative functional effects.
AB - Alpha- and beta-myosin heavy chain (MHC), the two MHC isoforms expressed in the
mammalian heart, differ quantitatively in their enzymatic activities. The MHC
composition of the heart can change dramatically in response to numerous stimuli,
leading to the hypothesis that changes in cardiac function can be caused by
myosin isoform shifts. However, this hypothesis has remained unproven because the
stimuli used to generate these shifts are complex and accompanied by many
additional physiological changes, including alterations in cardiac mass and
geometry. Adult mouse ventricles normally express only alpha-MHC (the faster
motor). To determine whether genetic alteration of the MHC isoform composition in
the adult mouse heart would result in changes in cardiac chamber mass and
contractility, we established transgenic mouse lines that express a Myc-tagged
beta-MHC molecule (the slower motor) in adult ventricular tissue, one of which
expresses 12% of its myosin as the transgene. There is no evidence of
hypertrophy, induction of hypertrophic markers, and no histopathology.
Myofibrillar Ca(2+)-activated ATPase activity is decreased by 23%, and
Langendorff preparations demonstrate a significant 15% decrease in systolic
function in transgenic hearts. These results suggest that even small shifts in
the myosin isoform composition of the myocardium can result in physiologically
significant changes in cardiac contractility and could be relevant to
cardiovascular disease.
PMID- 10666071
TI - Effects of recombinant eNOS gene expression on reactivity of small cerebral
arteries.
AB - Resistance arteries are an important target for vascular gene therapy because
they play a key role in the regulation of tissue blood flow. The present study
was designed to determine the effects of recombinant endothelial (e) nitric oxide
synthase (NOS) gene expression on vasomotor reactivity of small brain stem
arteries (internal diameter, 253 +/- 2.5 microm). Arterial rings were exposed ex
vivo to an adenoviral vector (10(9) and 10(10) plaque-forming units/ml) encoding
eNOS gene or beta-galactosidase gene. Twenty-four hours after transduction,
vascular function was examined by isometric force studies. Transgene expression
was evident mainly in adventitia. In arteries with endothelium transduced with
eNOS gene but not with control beta-galactosidase gene, relaxations to bradykinin
and substance P were significantly augmented. Removal of endothelium abolished
relaxations to bradykinin and substance P in control and beta-galactosidase
arteries. However, in endothelium-denuded arteries transduced with recombinant
eNOS, bradykinin and substance P caused relaxations that were abolished in the
presence of the NOS inhibitor N(G)-nitro-L-arginine methyl ester. In control
arteries, endothelium removal augmented relaxations to the nitric oxide donors
sodium nitroprusside and diethylamine NONOate. This augmentation was absent in
eNOS gene-transduced arteries without endothelium. Our results suggest that, in
small brain stem arteries, expression of recombinant eNOS increases biosynthesis
of nitric oxide. Adventitia of small arteries is a good target for expression of
recombinant eNOS. Genetically engineered adventitial cells may serve as a
substitute source of nitric oxide in cerebral arteries with dysfunctional
endothelium.
PMID- 10666072
TI - Increased aortic stiffness assessed by pulse wave velocity in apolipoprotein E
deficient mice.
AB - Atherosclerosis develops and progresses spontaneously in apolipoprotein E
knockout (apoE-KO) mice. A direct consequence of atherosclerosis is an increase
in vascular stiffness. Pulse wave velocity (PWV) has been used to assess the
stiffness of large vessels and was found to be increased in patients with
atherosclerosis. In the present study, aortic stiffness was assessed by PWV in 4-
and 13-mo-old apoE-KO mice and age-matched controls (C57BL/6J). In 13-mo-old apoE
KO mice with extensive atherosclerotic lesions in the aorta (61 +/- 4%), PWV
increased significantly (3.8 +/- 0.2 m/s) compared with controls (2.9 +/- 0.2
m/s). Endothelial nitric oxide (EDNO)-mediated vasorelaxation in response to ACh
was markedly diminished in the aortic rings isolated from 13-mo-old apoE-KO mice
compared with age-matched controls. In contrast, in 4-mo-old apoE-KO mice with
only moderate atherosclerotic lesions in the aorta (23 +/- 5%), there were no
significant changes in PWV and EDNO-mediated relaxation compared with controls.
Blood pressure was not different among the four groups of mice. There were no
significant differences in endothelium-independent vascular responses to sodium
nitroprusside among different groups investigated. Histological evaluation
revealed focal fragmentation of the elastic laminae in the aortic walls of 13-mo
old apoE-KO mice. These results demonstrate for the first time that aortic
stiffness determined by PWV increases in 13-mo-old apoE-KO mice. Endothelial
dysfunction and elastic destruction in vascular wall caused by atherosclerosis
may have contributed.
PMID- 10666073
TI - Role of leukocytes and tissue-derived oxidants in short-term skeletal muscle
ischemia-reperfusion injury.
AB - The relative contribution of xanthine oxidase (XO) and leukocytes to tissue
injury after short-term ischemia is unknown. In this study, we subjected three
groups of rat spinotrapezius muscles to 30-min ischemia and 1-h reperfusion: 1)
ischemia-reperfusion (I/R) + 0.9% saline, 2) I/R + superoxide dismutase, and 3)
I/R + oxypurinol. A fourth group served as nonischemic control. We quantified the
increase in resistance (%DeltaR) caused by leukocyte-capillary plugging
concurrently with myocyte uptake of propidium iodide (PI) [expressed as no. of PI
spots per total volume of perfused tissue (N(PI)/V)] and performed assays to
quantify XO activity, thiobarbituric acid-reactive substances (TBARS), and
myeloperoxidase (MPO). Groups 2 and 3 exhibited significant decreases in N(PI)/V
relative to group 1. MPO levels and TBARS were similar among all groups, and mean
%DeltaR was significantly reduced in groups 2 and 3 relative to group 1. However,
elevated XO was observed in groups 1 and 2 relative to group 3 and nonischemic
controls. These data are consistent with the hypothesis that XO, rather than
toxic species produced by plugging or venule-adherent leukocytes, is responsible
for postischemic damage in this model.
PMID- 10666074
TI - Measurements of calcium transients in ventricular cells during discontinuous
action potential conduction.
AB - The L-type calcium current (I(Ca)) is important in sustaining propagation during
discontinuous conduction. In addition, I(Ca) is altered during discontinuous
conduction, which may result in changes in the intracellular calcium transient.
To study this, we have combined the ability to monitor intracellular calcium
concentration ([Ca(2+)](i)) in an isolated cardiac cell using confocal scanning
laser fluorescence microscopy with our "coupling clamp" technique, which allows
action potential propagation from the real cell to a real-time simulation of a
model cell. Coupling a real cell to a model cell with a value of coupling
conductance (G(C) = 8 nS) just above the critical value for action potential
propagation results in both an increased amplitude and an increased rate of rise
of the calcium transient. Similar but smaller changes in the calcium transient
are caused by increasing G(C) to 20 nS. The increase of [Ca(2+)](i) by
discontinuous conduction is less than the increase of I(Ca), which may indicate
that much of [Ca(2+)](i) is the result of calcium released from the sarcoplasmic
reticulum rather than the integration of I(Ca).
PMID- 10666075
TI - Electrical interactions between a real ventricular cell and an anisotropic two
dimensional sheet of model cells.
AB - We have extended our "coupling clamp" technique, in which we couple a real cell
to a real-time simulation of a model cell, to now incorporate a real cardiac cell
as the central element of a two-dimensional sheet of model cells, in which the
coupling conductances may be different in the x and y directions and a specific
region of lack of coupling conductance may serve as a resistive barrier. We
stimulated the real cell in the central location and determined the critical size
of the real cell for successful activation of the entire sheet. We found that
this critical size was decreased when anisotropy was present compared with the
isotropic case and was further decreased when the central site of stimulation was
close to the resistive barrier. The heart normally has some degree of anisotropy,
and it has been shown that the remodeling that occurs in peri-infarction zones
produces a particular loss of lateral connections compared with end-to-end
connections among heart cells. We propose that the normal existence of anisotropy
and enhancement of the degree of anisotropy both by loss of lateral gap junctions
and the development of resistive barriers may play a facilitating role in the
development of ectopic foci that may lead to cardiac arrhythmias.
PMID- 10666076
TI - Reduced NO-dependent arteriolar dilation during the development of
cardiomyopathy.
AB - Our previous studies have suggested that there is reduced nitric oxide (NO)
production in canine coronary blood vessels after the development of pacing
induced heart failure. The goal of these studies was to determine whether flow
induced NO-mediated dilation is altered in coronary arterioles during the
development of heart failure. Subepicardial coronary arterioles (basal diameter
80 microm) were isolated from normal canine hearts, from hearts with dysfunction
but no heart failure, and from hearts with severe cardiac decompensation.
Arterioles were perfused at increasing flow or administered agonists with no flow
in vitro. In arterioles from normal hearts, flow increased arteriolar diameter,
with one-half of the response being NO dependent and one-half prostaglandin
dependent. Shear stress-induced dilation was eliminated by removing the
endothelium. Arterioles from normal hearts and hearts with dysfunction but no
failure responded to increasing shear stress with dilation that reached a maximum
at a shear stress of 20 dyn/cm(2). In contrast, arterioles from failing hearts
showed a reduced dilation, reaching only 55% of the dilation seen in vessels of
normal hearts at a shear stress of 100 dyn/cm(2). This remaining dilation was
eliminated by indomethacin, suggesting that the NO-dependent component was absent
in coronary microvessels after the development of heart failure. Similarly,
agonist-induced NO-dependent coronary arteriolar dilation was markedly attenuated
after the development of heart failure. After the development of severe dilated
cardiomyopathy and heart failure, the NO-dependent component of both shear stress
and agonist-induced arteriolar dilation is reduced or entirely absent.
PMID- 10666077
TI - Spatial variations in endothelial barrier function in disturbed flows in vitro.
AB - Hindered barrier function has been implicated in the initiation and progression
of atherosclerosis, a disease of focal nature associated with altered
hemodynamics. In this study, endothelial permeability to macromolecules and
endothelial electrical resistance were investigated in vitro in monolayers
exposed to disturbed flow fields that model spatial variations in fluid shear
stress found at arterial bifurcations. After 5 h of flow, areas of high shear
stress gradients showed a 5.5-fold increase in transendothelial transport of
dextran (molecular weight 70,000) compared with no-flow controls. Areas of
undisturbed fully developed flow, within the same monolayer, showed a 2.9-fold
increase. Monolayer electrical resistance decreased with exposure to flow. The
resistance measured during flow and the rate of change in monolayer resistance
after removal of flow were lowest in the vicinity of flow reattachment (highest
shear stress gradients). These results demonstrate that endothelial barrier
function and permeability to macromolecules are regulated by spatial variations
in shear stress forces in vitro.
PMID- 10666078
TI - Relationship between nociceptin/orphanin FQ and cerebral hemodynamics after
hypoxia-ischemia in piglets.
AB - This study was designed to characterize the role of the newly described
endogenous opioid nociceptin/orphanin FQ (NOC/oFQ) in reduced cerebral blood flow
(CBF) observed after ischemia-reperfusion (I/R) and combined hypoxia and ischemia
reperfusion (H-I/R), as a function of time after onset of reperfusion in newborn
pigs equipped with a closed cranial window. Global cerebral ischemia (20 min) was
induced via elevation of intracranial pressure, whereas hypoxia (10 min)
decreased PO(2) to 35 +/- 3 mmHg with unchanged PCO(2). I/R elevated
cerebrospinal fluid (CSF) NOC/oFQ from 67 +/- 4 to 266 +/- 29 pg/ml within 1 h,
whereas values returned to control level within 4 h of reperfusion. H-I/R
elevated CSF NOC/oFQ to 483 +/- 67 pg/ml within 1 h, and such values returned
slowly to control level within 12 h of reperfusion. Topical NOC/oFQ (10(-8) M,
10(-6) M)-induced vasodilation was attenuated by I/R and reversed to
vasoconstriction by H-I/R at 1 h of reperfusion (control, 9 +/- 1 and 16 +/- 1%;
I/R, 3 +/- 1 and 6 +/- 1%; H-I/R, -6 +/- 1 and -11 +/- 1%). Such altered dilation
returned to control values within 4 h in I/R animals and within 12 h in H-I/R
animals. Blood flow in the cerebrum was reduced from 58 +/- 4 to 33 +/- 2 ml x
min(-1) x 100 g(-1) within 1 h and returned to control value within 4 h in I/R
animals. In animals pretreated with [F/G]NOC/oFQ(1-13)-NH(2) (1 mg/kg iv), an
NOC/oFQ antagonist, however, CBF only fell to 43 +/- 3 ml x min(-1) x 100 g(-1)
at 1 h of reperfusion. Similar observations were made in H-I/R animals. These
data suggest that an elevated CSF NOC/oFQ concentration and altered vascular
responsiveness to this opioid contribute to reductions in CBF observed after
either I/R or H-I/R.
PMID- 10666079
TI - Developmental differences in delayed rectifying outward current in feline
ventricular myocytes.
AB - In the present work, we found that the delayed rectifying outward potassium
current (I(K)) in adult and neonatal cat ventricular myocytes consists of both
rapid and slow components, I(Kr) and I(Ks), respectively, which can be isolated
pharmacologically. Thus after complete blockade of I(Kr) with dofetilide, the
remaining I(Ks) current is homogeneous, as shown by an envelope of tails test.
I(Kr) maximum tail current density, measured at -40 mV, was similar in adult and
neonatal myocytes. I(Ks) maximum tail current density in neonatal myocytes,
measured at -40 mV, was significantly smaller than in adult myocytes. Activation
kinetics of I(Kr) and I(Ks) was similar in both age groups. However, the I(Kr)
deactivation time course was significantly faster in neonatal than in adult
myocytes. Developmental differences in the subunit composition of I(Kr) that
display distinctly different deactivation kinetics are suggested.
PMID- 10666080
TI - Role of endothelin receptor subtypes in volume-stimulated ANF secretion.
AB - The role of endothelin (ET) receptors was tested in volume-stimulated atrial
natriuretic factor (ANF) secretion in conscious rats. Mean ANF responses to slow
infusions (3 x 3.3 ml/8 min) were dose dependently reduced (P < 0.05) by bosentan
(nonselective ET-receptor antagonist) from 64.1 +/- 18.1 (SE) pg/ml (control) to
52.6 +/- 16.1 (0.033 mg bosentan/rat), 16.1 +/- 7.6 (0. 33 mg/rat), and 11.6 +/-
6.5 pg/ml (3.3 mg/rat). The ET-A-receptor antagonist BQ-123 (1 mg/rat) had no
effect relative to DMSO controls, whereas the putative ET-B antagonist IRL-1038
(0.1 mg/rat) abolished the response. In a second protocol, BQ-123 (>/=0.5 mg/rat)
nonsignificantly reduced the peak ANF response (106.1 +/- 23.0 pg/ml) to 74.0 +/-
20.5 pg/ml for slow infusions (3.5 ml/8.5 min) but reduced the peak response
(425.3 +/- 58.1 pg/ml) for fast infusions (6.6 ml/1 min) by 49.9% (P < 0.001) and
for 340 pmoles ET-1 (328.8 +/- 69.5 pg/ml) by 83.5% (P < 0.0001). BQ-123
abolished the ET-1-induced increase in arterial pressure (21.8 +/- 5.2 mmHg at 1
min). Changes in central venous pressure were similar for DMSO and BQ-123 (slow:
0.91 and 1.14 mmHg; fast: 4.50 and 4.13 mmHg). The results suggest 1) ET-B
receptors mainly mediate the ANF secretion to slow volume expansions of
<1.6%/min; and 2) ET-A receptors mainly mediate the ANF response to acute volume
overloads.
PMID- 10666081
TI - Elevated salt intake impairs dilation of rat skeletal muscle resistance arteries
via ANG II suppression.
AB - Vasodilator responses were assessed in resistance arteries (100-200 microm)
isolated from the gracilis muscle of normotensive rats after changes in dietary
salt intake. Sprague-Dawley rats were maintained on either a high-salt (HS) diet
(4.0% NaCl) or a low-salt (LS) diet (0.4% NaCl) for 4-8 wk (chronic) or 3 days
(short-term) with water ad libitum. One group of short-term HS rats received a
continuous intravenous infusion of a low dose (5 ng x kg(-1) x min(-1)) of ANG II
to prevent the ANG II suppression that occurs with HS diet. Short-term and
chronic HS diet eliminated arterial dilation in response to ACh and reduced PO(2)
(30-40 mmHg) and the stable prostacyclin analog iloprost. ANG II infusion
preserved the response to these vasodilator stimuli in short-term HS animals.
Dilator responses to sodium nitroprusside and forskolin were unaffected by HS
diet. These findings suggest that ANG II suppression during HS diet impairs
vascular relaxation mechanisms upstream from the cAMP and cGMP second messenger
systems.
PMID- 10666082
TI - Role of kinins in chronic heart failure and in the therapeutic effect of ACE
inhibitors in kininogen-deficient rats.
AB - Using Brown Norway Katholiek (BNK) rats, which are deficient in kininogen (kinin
precursor) due to a mutation in the kininogen gene, we examined the role of
endogenous kinins in 1) normal cardiac function; 2) myocardial infarction (MI)
caused by coronary artery ligation; 3) cardiac remodeling in the development of
heart failure (HF) after MI; and 4) the cardioprotective effect of angiotensin
converting enzyme inhibitors (ACEI) on HF after MI. Two months after MI, rats
were randomly treated with vehicle or the ACEI ramipril for 2 mo. Brown Norway
rats (BN), which have normal kininogen, were used as controls. Left ventricular
(LV) end-diastolic volume (EDV), end-systolic volume (ESV), end-diastolic
pressure (EDP), and ejection fraction (EF) as well as myocardial infarct size
(IS), interstitial collagen fraction (ICF), cardiomyocyte cross-sectional area
(MCA), and oxygen diffusion distance (ODD) were measured. We found that 1)
cardiac hemodynamics, function, and histology were the same in sham-ligated BN
and BNK rats; 2) IS was similar in BN and BNK; 3) in rats with HF treated with
vehicle, the decrease in LVEF and the increase in LVEDV, LVESV, LVEDP, ICF, MCA,
and ODD did not differ between BNK and BN; and 4) ACEI increased EF, decreased
LVEDV and LVESV, and improved cardiac remodeling in BN-HF rats, and these effects
were partially blocked by the bradykinin B(2) receptor antagonist icatibant (HOE
140). In BNK-HF rats, ACEI failed to produce these beneficial cardiac effects. We
concluded that in rats, lack of kinins does not influence regulation of normal
cardiac function, myocardial infarct size, or development of HF; however, kinins
appear to play an important role in the cardioprotective effect of ACEI, since 1)
this effect was significantly diminished in kininogen-deficient rats and 2) it
was blocked by a B(2) kinin receptor antagonist in BN rats.
PMID- 10666083
TI - Effects of autonomic disruption and inactivity on venous vascular function.
AB - The effects of autonomic disruption and inactivity were studied on the venous
vascular system. Forty-eight subjects, 24 with spinal cord injury (SCI) and 12
sedentary and 12 active able-bodied controls, participated in this study.
Peripheral autonomic data were obtained to estimate sympathetic vasomotor control
[low-frequency component of systolic blood pressure (LF(SBP))]. Vascular
parameters were determined using strain-gauge venous occlusion plethysmography:
venous capacitance (VC), venous emptying rate (VER), and total venous outflow
(VO(t)). An additional vascular parameter was calculated: venous compliance
[(VC/occlusion pressure) x 100]. VC and VO(t) were significantly different (SCI <
sedentary < active). VER adjusted for VC was not different for any group
comparison, whereas venous compliance was significantly lower in the SCI group
than in the able-bodied groups and in the sedentary group compared with the
active group. Regression analysis for the total group revealed a significant
relationship between LF(SBP) and venous compliance (r = 0.64, P < 0.0001). After
controlling for LF(SBP) through analysis of covariance, we found that mean
differences for all venous vascular parameters did not change from unadjusted
mean values. Our findings suggest that in subjects with SCI, the loss of
sympathetic vasomotor tone contributes more than inactivity to reductions in
venous vascular function. Heightened VC, VO(t), vasomotor tone, and venous
compliance in the active group compared with the sedentary group imply that
regular endurance training contributes to optimal venous vascular function and
peripheral autonomic integrity.
PMID- 10666084
TI - Mechanical stretch stimulates growth of vascular smooth muscle cells via
epidermal growth factor receptor.
AB - We have studied whether activation of epidermal growth factor receptor (EGFR) is
involved in stretch-induced extracellular signal-regulated kinase 1/2 (ERK1/2)
activation and protein synthesis in cultured rat vascular smooth muscle cells
(VSMC). Cyclic stretch (1 Hz) induced a rapid (within 5 min) phosphorylation of
ERK1/2, an effect that was time and strength dependent and inhibited by an EGFR
kinase inhibitor (AG-1478) but not by a platelet-derived growth factor receptor
kinase inhibitor (AG-1296). The stretch rapidly (within 2 min) induced tyrosine
phosphorylation of several proteins, among which 180-kDa protein was shown to be
EGFR as revealed by blockade with AG-1478 as well as immunoprecipitation with
anti-EGFR antibody coupled with immunoblotting with anti-phosphotyrosine
antibody. The stretch rapidly (within 2 min) induced association of tyrosine
phosphorylated EGFR with adaptor proteins (Shc/Grb2) as revealed by
coprecipitation with glutathione-S-transferase-Grb2 fusion protein coupled with
immunoblotting with anti-phosphotyrosine, anti-EGFR, and anti-Shc antibodies.
Transfection of a dominant-negative mutant of H-Ras also inhibited stretch
induced ERK1/2 activation. Treatment with a stretch-activated ion channel blocker
(Gd(3+)) and an intracellular Ca(2+) antagonist (TMB-8) inhibited stretch-induced
phosphorylation of EGFR and ERK1/2. Treatment with AG-1478 and a mitogen
activated protein kinase kinase inhibitor (PD-98059), but not AG-1296, blocked
[(3)H]leucine uptake stimulated by a high level of stretch. These data suggest
that ERK1/2 activation by mechanical stretch requires Ca(2+)-sensitive EGFR
activation mainly via stretch-activated ion channels, thereby leading to VSMC
growth.
PMID- 10666085
TI - Muscle metaboreflex control of cardiac output and peripheral vasoconstriction
exhibit different latencies.
AB - Experiments were designed to determine 1) the mechanisms mediating metaboreflex
induced increases in systemic arterial pressure (SAP) in response to total
vascular occlusion of hindlimb blood flow [e.g., increases in cardiac output (CO)
vs. peripheral vasoconstriction] and 2) whether the individual mechanisms display
differential latencies for the onset of the responses. Responses were observed in
seven dogs performing steady-state treadmill exercise of mild and moderate
workloads (3.2 km/h at 0% grade and 6.4 km/h at 10% grade). Differential
latencies were exhibited among CO, nonischemic vascular conductance (NIVC;
conductance to all nonischemic vascular beds), and renal vascular conductance
(RVC), with peripheral vasoconstriction significantly preceding metaboreflex
mediated increases in CO. In addition, the latencies for SAP were not different
from those for NIVC or RVC at either workload. During the lower workload there
were small increases and then subsequent decreases in CO before the metaboreflex
induced increase in CO, which did contribute somewhat to the initial increases in
SAP. However, the increases in CO mediated by the metaboreflex occurred
significantly later than the initial increases in SAP. Therefore, we conclude
that the substantial metaboreflex-mediated pressor responses that occur during
the initial phase of total vascular occlusion during mild and moderate exercise
are primarily caused by peripheral vasoconstriction.
PMID- 10666086
TI - Increased urinary excretion of uroguanylin in patients with congestive heart
failure.
AB - Uroguanylin is a small-molecular-weight peptide that activates membrane-bound
receptor-guanylate cyclases in the intestine, kidney, and other epithelia.
Uroguanylin has been shown to participate in the regulation of salt and water
homeostasis in mammals via cGMP-mediated processes, bearing a distinct similarity
to the action of the atriopeptins, which play a defined role in natriuresis and
act as prognostic indicators of severe congestive heart failure (CHF). The
objectives of this study were to measure the urinary levels of uroguanylin and
the circulating plasma levels of atrial natriuretic peptide (ANP) in healthy
individuals (n = 53) and patients with CHF (n = 16). Urinary excretion of
uroguanylin was assessed by a cGMP accumulation bioassay employing human T84
intestinal cells. In individuals without CHF, the concentration of uroguanylin
bioactivity was 1.31 +/- 0.27 nmol cGMP/ml urine and 1.73 +/- 0.25 micromol
cGMP/24-h urine collection. The urinary bioactivity of uroguanylin in males (1.74
+/- 0.55 nmol cGMP/ml urine; n = 27) tended to be higher than the excretion
levels in females (0.94 +/- 0.16 nmol cGMP/ml urine; n = 26) over a 24-h period
but did not achieve statistical significance. Both male and female groups showed
24-h temporal diurnal variations with the highest uroguanylin levels observed
between the hours of 8:00 AM and 2:00 PM. The circulating level of ANP was 12.1
+/- 1.6 pg/ml plasma and did not significantly vary with respect to male/female
population or diurnal variation. In patients with CHF, the concentration of
plasma ANP and urinary uroguanylin bioactivity increased substantially (7.5-fold
and 70-fold, respectively, both P = 0.001) compared with healthy levels.
Uroguanylin was purified from the urine of CHF patients and shown to be the
bioactive, COOH-terminal, 16 amino acid portion of the human prouroguanylin
protein. The increased urinary uroguanylin excretion observed during CHF may be
an adaptive response to this cardiovascular pathophysiology.
PMID- 10666087
TI - Stretch-activated whole cell currents in adult rat cardiac myocytes.
AB - Mechanoelectric transduction can initiate cardiac arrhythmias. To examine the
origins of this effect at the cellular level, we made whole cell voltage-clamp
recordings from acutely isolated rat ventricular myocytes under controlled
strain. Longitudinal stretch elicited noninactivating inward cationic currents
that increased the action potential duration. These stretch-activated currents
could be blocked by 100 microM Gd(3+) but not by octanol. The current-voltage
relationship was nearly linear, with a reversal potential of approximately -6 mV
in normal Tyrode solution. Current density varied with sarcomere length (SL)
according to I (pA/pF) = 8.3 - 5.0 SL (microm). Repeated attempts to record
single channel currents from stretch-activated ion channels failed, in accord
with the absence of such data from the literature. The inability to record single
channel currents may be a result of channels being located on internal membranes
such as the T tubules or, possibly, inactivation of the channels by the mechanics
of patch formation.
PMID- 10666088
TI - Effects of central infusion of ANG II and losartan on the cardiac baroreflex in
rabbits.
AB - The effect of chronic activation or inhibition of central ANG II receptors on
cardiac baroreflex function in conscious normotensive rabbits was examined.
Animals received a fourth ventricular (4V) infusion of ANG II (30 and 100 ng/h),
losartan (3 and 30 microg/h), or Ringer solution (2 microl/h) for 2 wk. After 1
and 2 wk, ANG II (100 ng/h) decreased cardiac baroreflex gain by 20 and 37%,
respectively (P = 0.015), whereas losartan (30 microg/h) increased baroreflex
gain by 24 and 58%, respectively (P = 0.02). Within 1 wk of the end of the
infusions, cardiac baroreflex gain had returned to control. Ringer solution or
the lower doses of ANG II or losartan did not modify the cardiac baroreflex
function. Blood pressure and heart rate were not altered by any treatment, nor
was their variability affected. These data demonstrate a novel long-term
modulation of cardiac baroreflexes by endogenous ANG II that is independent of
blood pressure level.
PMID- 10666089
TI - Effects of potassium channel modulators on myotropic responses of aortic rings of
pregnant rats.
AB - The contribution of potassium channels [ATP-sensitive potassium (K(ATP)) and high
conductance calcium-activated potassium (BK(Ca)) channels] in the resistance of
aortic rings of term pregnant rats to phenylephrine (Phe), arginine vasopressin
(AVP), and KCl was investigated. Concentration-response curves to
tetraethylammonium (TEA), a nonselective K(+) channel inhibitor, were obtained in
the absence or presence of KCl. TEA induced by itself concentration-dependent
responses only in aortic rings of nonpregnant rats. These responses to TEA could
be modulated in both groups of rings by preincubation with different
concentrations of KCl. Concentration-response curves to Phe, AVP, and KCl were
obtained in the absence or presence of cromakalim or NS-1619 (K(ATP) and BK(Ca)
openers, respectively) and glibenclamide or iberiotoxin (K(ATP) and BK(Ca)
inhibitors, respectively). Cromakalim significantly inhibited the responses to
the three agonists in a concentration-dependent manner in both groups of rats.
Alternatively, in the pregnant group of rats, glibenclamide increased the
sensitivity to all three agonists. NS-1619 also inhibited the response to all
agonists. With AVP and KCl, its effect was greater in aortic rings of pregnant
than nonpregnant rats. Finally, iberiotoxin increased the sensitivity to all
three agents. This effect was more important in aortic rings of nonpregnant rats
and was accompanied by an increase of the maximal response to Phe and AVP. These
results suggest that potassium channels are implicated in the control of basal
membrane potential and in the blunted responses to these agents during pregnancy.
PMID- 10666090
TI - Frequency limits on aortic baroreceptor input to nucleus tractus solitarii.
AB - The frequency of baroreceptor volleys to the central nervous system can influence
the fidelity of baroreceptor signal transmission and thus may affect baroreflex
regulation of blood pressure. We examined 1) the extent to which frequency
dependent depression of aortic baroreceptor signals was initiated at the first
central synapse between primary baroreceptor fibers and second-order nucleus
tractus solitarii (NTS) neurons; 2) whether the pattern of baroreceptor input
influenced the depression; and 3) the potential relevance to baroreflex
sympathoinhibition. In urethan-anesthetized rats, NTS action potential responses
of neurons classified as second or higher order and averaged lumbar sympathetic
nerve activity responses were simultaneously measured during 100 aortic depressor
nerve stimuli delivered in constant or phasic patterns (0.8-48 Hz). Frequency
dependent depression was initiated at second-order neurons, with NTS responses
decreasing to a 72% response rate at 48 Hz; the depression was greater at higher
order neurons; responses decreased to a 30% response rate. The depression was
slightly but significantly greater with phasic inputs. Curve fitting suggested
that synaptic depression may limit baroreflex sympathoinhibition. Thus frequency
limits on baroreceptor inputs at NTS synapses may affect baroreflex function.
PMID- 10666091
TI - Gene transfer of calcitonin gene-related peptide to cerebral arteries.
AB - Overexpression of calcitonin gene-related peptide (CGRP), an extremely potent
vasodilator, to blood vessels is a possible strategy for prevention of vasospasm.
We constructed an adenoviral vector that encodes prepro-CGRP (Adprepro-CGRP) and
examined the effects of gene transfer on cultured cells and cerebral arteries.
Transfection of Adprepro-CGRP to Cos-7 and NIH-3T3 cells increased CGRP-like
immunoreactivity in media and produced an increase in cAMP in recipient cells.
Five days after injection of Adprepro-CGRP into the cisterna magna of rabbits,
the concentration of CGRP-like immunoreactivity increased by 93-fold in
cerebrospinal fluid. In basilar artery, cAMP increased by 2.3-fold after Adprepro
CGRP compared with a control adenovirus. After transfection of Adprepro-CGRP,
contraction of basilar artery in vitro to histamine and serotonin was attenuated,
and relaxation to an inhibitor of cyclic nucleotide phosphodiesterase 3-isobutyl
1-methylxanthine was augmented compared with nontransduced arteries or arteries
transfected with a control gene. Altered vascular responses were restored to
normal by pretreatment with a CGRP(1) receptor antagonist CGRP-(8-37). Thus gene
transfer of prepro-CGRP in vivo overexpresses CGRP in cerebrospinal fluid and
perivascular tissues and modulates vascular tone. We speculate that this approach
may be useful in prevention of vasospasm after subarachnoid hemorrhage.
PMID- 10666093
TI - Resolution of smooth muscle and endothelial pathways for conduction along hamster
cheek pouch arterioles.
AB - In the cheek pouch of anesthetized male hamsters, microiontophoresis of Ach
(endothelium-dependent vasodilator) or phenylephrine (PE; smooth muscle-specific
vasoconstrictor) onto an arteriole (resting diameter, 30-40 microm) evokes
vasodilation or vasoconstriction (amplitude, 15-25 microm), respectively, that
conducts along the arteriolar wall. In previous studies of conduction,
endothelial and smooth muscle layers of the arteriolar wall have remained intact.
We tested whether selective damage to endothelium or to smooth muscle would
disrupt the initiation and conduction of vasodilation or vasoconstriction.
Luminal (endothelial) or abluminal (smooth muscle) light-dye damage was produced
within an arteriolar segment centered 500 microm upstream from the distal site of
stimulation; conducted responses (amplitude, 10-15 microm) were observed at a
proximal site located 1,000 microm upstream. Endothelial damage abolished local
responses to ACh in the central segment without affecting those to PE.
Nevertheless, ACh delivered at the distal site evoked vasodilation that conducted
through the central segment and appeared unhindered at the proximal site. Smooth
muscle damage inhibited responses to PE in the central segment and abolished the
conduction of vasoconstriction but did not affect conducted vasodilation. We
suggest that for cheek pouch arterioles in vivo, vasoconstriction to PE is
initiated and conducted within the smooth muscle layer alone. In contrast, once
vasodilation to ACh is initiated via intact endothelial cells, the signal is
conducted along smooth muscle as well as endothelial cell layers.
PMID- 10666092
TI - Glucose-insulin-potassium preserves systolic and diastolic function in ischemia
and reperfusion in pigs.
AB - Clinical and experimental studies have suggested benefit of treatment with
intravenous glucose-insulin-potassium (GIK) in acute myocardial infarction.
However, patients hospitalized with acute coronary syndromes often experience
recurrent myocardial ischemia without infarction that may cause progressive left
ventricular (LV) dysfunction. This study tested the hypothesis that anticipatory
treatment with GIK attenuates both systolic and diastolic LV dysfunction
resulting from ischemia and reperfusion without infarction in vivo. Open-chest,
anesthetized pigs underwent 90 min of moderate regional ischemia (mean
subendocardial blood flow 0.3 ml x g(-1) x min(-1)) and 90 min reperfusion. Eight
pigs were treated with GIK (300 g/l glucose, 50 U/l insulin, and 80 meq/l KCl;
infused at 2 ml x kg(-1) x h(-1)) beginning 30 min before ischemia and continuing
through reperfusion. Eight untreated pigs comprised the control group. Regional
LV wall area was measured with orthogonal pairs of sonomicrometry crystals. GIK
significantly increased myocardial glucose uptake and lactate release during
ischemia. After reperfusion, indexes of regional systolic function (external work
and fractional systolic wall area reduction), regional diastolic function
(maximum rate of diastolic wall area expansion), and global LV function (LV
positive and negative maximum rate of change in pressure with respect to time)
recovered to a significantly greater extent in GIK-treated pigs than in control
pigs (all P < 0.05). The findings suggest that the clinical utility of GIK may
extend beyond treatment of acute myocardial infarction to anticipatory metabolic
protection of myocardium in patients at risk for recurrent episodes of ischemia.
PMID- 10666094
TI - AT(1) receptor inhibition does not reduce arterial wall hypertrophy or PDGF-A
expression in renal hypertension.
AB - To separate the role of ANG II from pressure in hypertrophy of the vascular wall
in one-kidney, one-clip (1K1C) hypertension, experimental and sham-operated rats
were given the AT(1)-receptor antagonist losartan (20 mg x kg(-1) x day(-1)) or
tap water for 14 days. Mean arterial pressure was elevated in both experimental
groups compared with controls. Rats were anesthetized with pentobarbital sodium,
and the thoracic aorta and carotid, small mesenteric, and external spermatic
arteries were harvested and embedded in paraffin. Tissue sections were used for
morphological analysis, immunohistochemistry for 5-bromo-2'-deoxyuridine (BrdU)
and platelet-derived growth factor (PDGF)-AA, stereological measurements, and in
situ hybridization with a (35)S-labeled riboprobe for PDGF-A mRNA. Elevated cross
sectional areas of thoracic, carotid, and small mesenteric artery in 1K1C rats
were not reduced by losartan. The internal diameter of the external spermatic
artery and microvascular density of the cremaster muscle were reduced in 1K1C
rats. The number of BrdU-positive nuclei per cross section did not differ between
1K1C and control arteries. PDGF-A mRNA was elevated in the arterial walls of 1K1C
rats compared with controls and was hardly changed by losartan. PDGF-A protein
stained strongly in the media of 1K1C arteries and was not inhibited by losartan;
it appeared in the adventitia of all aortas and carotid arteries. These
observations demonstrate that effects of ANG II mediated through the AT(1)
receptor are not necessary for hypertrophy of the vascular wall during 1K1C
hypertension or expression of PDGF-A.
PMID- 10666095
TI - Protective roles of endogenous carbon monoxide in neointimal development elicited
by arterial injury.
AB - We reported that carbon monoxide (CO) generated through heme oxygenase (HO)
inhibits mitogen-induced proliferation of vascular smooth muscle cells (VSMCs).
We report that balloon injury induces HO-1, the stress-inducible isozyme of HO,
in VSMCs and inhibits neointimal formation through the action of endogenous CO.
Northern blot analysis and immunohistochemistry revealed that HO-1 is markedly
induced in the media as early as 1 day after injury, whereas only a little
expression was detected in the intact carotid artery. The neointimal
proliferative changes were augmented or inhibited by the HO inhibitors or
inducer, respectively, and effects of these interventions were not altered by
suppression of endogenous nitric oxide (NO), if any. To elucidate the mechanisms
by which HO controls the proliferative changes, effects of alterations in the HO
reaction were examined by determining angiotensin II-elicited VSMC proliferation
in vitro: the HO inducer attenuated and its inhibitor restored the proliferative
response to angiotensin II (1 nM and 100 nM). Hemoglobin, a reagent trapping both
NO and CO, but not met-hemoglobin, which can capture NO but not CO, augmented the
proliferative response. These data suggest that endogenous CO serves as a
protective factor that limits the excessive VSMC proliferation associated with
vascular diseases.
PMID- 10666096
TI - Ventricular adrenomedullin concentration is a sensitive biochemical marker for
volume and pressure overload in rats.
AB - This study was designed to investigate the pathophysiological significance of
adrenomedullin (AM) concentration in volume- and pressure-overloaded cardiac
hypertrophy. We measured ventricular AM concentrations and compared them with
changes of alpha-actin and myosin heavy chain (MHC) mRNA isoforms after the
creation of an aortocaval (AC) shunt as a volume-overload model or the injection
of monocrotaline (MCT) as a pressure-overload model, respectively. The left
ventricular AM levels after the creation of AC shunt and the right ventricular AM
levels after the injection of MCT were significantly increased and correlated
with changes of the alpha-actin and MHC mRNA isoforms. However, the ventricular
AM mRNA expressions were increased and correlated with ventricular AM
concentrations only in the AC shunt model. These results suggest that the
ventricular AM levels are upregulated in both the volume- and pressure-overloaded
cardiac hypertrophy by differential transcriptional regulation and that the
ventricular AM may be a biochemical marker for the volume and pressure overload
to the ventricle.
PMID- 10666097
TI - Heme oxygenase-1-derived bilirubin ameliorates postischemic myocardial
dysfunction.
AB - Bilirubin is a potent antioxidant generated intracellularly during the
degradation of heme by the enzyme heme oxygenase. The purpose of this study was
to determine the role of increased cardiac bilirubin in protection against
postischemic myocardial dysfunction. Rat hearts were isolated and perfused
according to the Langendorff technique to evaluate the recovery of myocardial
function after 30 min of global ischemia and 60 min of reperfusion. We found that
upregulation of the inducible isoform of heme oxygenase (HO-1) by treatment of
animals with hemin 24 h before ischemia ameliorated myocardial function and
reduced infarct size (tetrazolium staining) on reperfusion of isolated hearts.
Tin protoporphyrin IX, an inhibitor of heme oxygenase activity, completely
abolished the improved postischemic myocardial performance observed after hemin
mediated HO-1 induction. Likewise, cardiac tissue injury was exacerbated by
treatment with tin protoporphyrin IX. Increased cardiac HO-1 expression and heme
oxygenase activity were associated with enhanced tissue bilirubin content and an
increased rate of bilirubin release into the perfusion buffer. Furthermore,
exogenously administered bilirubin at concentrations as low as 100 nanomolar
significantly restored myocardial function and minimized both infarct size and
mitochondrial damage on reperfusion. Our data provide strong evidence for a
primary role of HO-1-derived bilirubin in cardioprotection against reperfusion
injury.
PMID- 10666098
TI - Developmental changes of cardiac function and mass assessed with MRI in neonatal,
juvenile, and adult mice.
AB - Cardiovascular transgenic mouse models with an early phenotype or even premature
death require noninvasive imaging methods that allow for accurate visualization
of cardiac morphology and function. Thus the purpose of our study was to assess
the feasibility of magnetic resonance imaging (MRI) to characterize cardiac
function and mass in newborn, juvenile, and adult mice. Forty-five C57bl/6 mice
from seven age groups (3 days to 4 mo after birth) were studied by MRI under
isoflurane anesthesia. Electrocardiogram-gated cine MRI was performed with an in
plane resolution of (78-117 microm)(2). Temporal resolution per cine frame was
8.6 ms. MRI revealed cardiac anatomy in mice from all age groups with high
temporal and spatial resolution. There was close correlation between MRI- and
autopsy-determined left ventricular (LV) mass (r = 0.95, SE of estimate = 9.5
mg). The increase of LV mass (range 9.6-101.3 mg), cardiac output (range 1.1-14.3
ml/min), and stroke volume (range 3. 2-40.2 microl) with age could be quantified
by MRI measurements. Ejection fraction and cardiac index did not change with
aging. However, LV mass index decreased with increasing age (P < 0.01). High
resolution MRI allows for accurate in vivo assessment of cardiac function in
neonatal, juvenile, and adult mice. This method should be useful when applied in
transgenic mouse models.
PMID- 10666099
TI - Quantification of eNOS mRNA in the canine cardiac vasculature by competitive PCR.
AB - The goal of the present study was to develop a competitive PCR assay to measure
changes in the expression of endothelial nitric oxide synthase (eNOS) mRNA levels
throughout the canine vascular tree. A partial sequence of canine eNOS cDNA (1.86
kb), inducible NOS (1.95 kb), and neuronal NOS (1.16 kb) was cultured from canine
aortic endothelial cells, LPS-treated canine splenic vein endothelial cells, and
from canine left ventricle, respectively. Competitor eNOS cDNA (eNOS-C) was
constructed via recombinant PCR. Thus, with the use of a standard curve
competitive PCR with eNOS-C, the amount of eNOS mRNA in 500 ng of total RNA was
greatest in the circumflex > right coronary artery > left anterior descending
coronary artery > aorta. The isolation of coronary microvessels from the left
ventricle was associated with an enrichment of endothelial cell markers such as
eNOS, von Willebrand factor, and caveolin-1, an observation supported by the
detection of up to 15-fold higher levels of eNOS mRNA in coronary microvessels
relative to the larger arteries. The ability to quantify changes in eNOS mRNA
levels throughout the canine vasculature should provide greater insight into the
molecular mechanisms of how this gene is regulated in physiological and
pathophysiological states.
PMID- 10666100
TI - Caffeine-induced Ca(2+) sparks in mouse ventricular myocytes.
AB - Ca(2+) sparks are spatially localized intracellular Ca(2+) release events that
were first described in 1993. Sparks have been ascribed to sarcoplasmic reticulum
Ca(2+) release channel (ryanodine receptor, RyR) opening induced by Ca(2+) influx
via L-type Ca(2+) channels or by spontaneous RyR openings and have been thought
to reflect Ca(2+) release from a cluster of RyR. Here we describe a
pharmacological approach to study sparks by exposing ventricular myocytes to
caffeine with a rapid solution-switcher device. Sparks under these conditions
have properties similar to naturally occurring sparks in terms of size and
intracellular Ca(2+) concentration ([Ca(2+)](i)) amplitude. However, after the
diffusion of caffeine, sparks first appear close to the cell surface membrane
before coalescing to produce a whole cell transient. Our results support the idea
that a whole cell [Ca(2+)](i) transient consists of the summation of sparks and
that Ca(2+) sparks consist of the opening of a cluster of RyR and confirm that
characteristics of the cluster rather than the L-type Ca(2+) channel-RyR relation
determine spark properties.
PMID- 10666101
TI - Tyrosine kinase and protein kinase C regulate L-type Ca(2+) current cooperatively
in human atrial myocytes.
AB - The effects of tyrosine protein kinases (TK) on the L-type Ca(2+) current (I(Ca))
were examined in whole cell patch-clamped human atrial myocytes. The TK
inhibitors genistein (50 microM), lavendustin A (50 microM), and tyrphostin 23
(50 microM) stimulated I(Ca) by 132 +/- 18% (P < 0.001), 116 +/- 18% (P < 0.05),
and 60 +/- 6% (P < 0.001), respectively. After I(Ca) stimulation by genistein,
external application of isoproterenol (1 microM) caused an additional increase in
I(Ca). Dialyzing the cells with a protein kinase A inhibitor suppressed the
effect of isoproterenol on I(Ca) but not that of genistein. Inhibition of protein
kinase C (PKC) by pretreatment of cells with 100 nM staurosporine or 100 nM
calphostin C prevented the effects of genistein on I(Ca). The PKC activator
phorbol 12-myristate 13-acetate (PMA), after an initial stimulation (75 +/- 17%,
P < 0.05), decreased I(Ca) (-36 +/- 5%, P < 0.001). Once the inhibitory effect of
PMA on I(Ca) had stabilized, genistein strongly stimulated the current (323 +/-
25%, P < 0.05). Pretreating myocytes with genistein reduced the inhibitory effect
of PMA on I(Ca). We conclude that, in human atrial myocytes, TK inhibit I(Ca) via
a mechanism that involves PKC.
PMID- 10666103
TI - An appreciation: eugene rannels
PMID- 10666102
TI - Seven years at the wheel
PMID- 10666104
TI - How does cAMP increase active Na absorption across alveolar epithelium?
PMID- 10666105
TI - Mechanisms of increased Na(+) transport in ATII cells by cAMP: we agree to
disagree and do more experiments.
AB - Existing evidence supports the presence of active transport of Na(+) across the
mammalian alveolar epithelium and its upregulation by agents that increase
cytoplasmic cAMP levels. However, there is controversy regarding the mechanisms
responsible for this upregulation. Herein we present the results of various patch
clamp studies indicating the presence of 25- to 27-pS, amiloride-sensitive,
moderately selective Na(+) channels (Na(+)-to-K(+) permeability ratio = 7:1)
located on the apical membranes of rat alveolar type II (ATII) cells maintained
in primary culture. The addition of terbutaline to the bath solution increased
the open probability of single channels present in cell-attached patches of ATII
cells without affecting their conductance. A similar increase in open probability
was seen after the addition of protein kinase A, ATP, and Mg(2+) to the
cytoplasmic side of inside-out patches. Measurement of short-circuit currents
across confluent monolayers of rat or rabbit ATII cells indicates that
terbutaline and 8-(4-chlorophenylthio)-cAMP increase vectorial Na(+) transport
and activate Cl(-) channels. Currently, there is a controversy as to whether the
cAMP-induced increase in Na(+) transport is due solely to hyperpolarization of
the cytoplasmic side of the ATII cell membrane due to Cl(-) influx or whether it
results from simultaneous stimulation of both Cl(-) and Na(+) conductive
pathways. Additional studies are needed to resolve this issue.
PMID- 10666106
TI - Cl-channel activation is necessary for stimulation of Na transport in adult
alveolar epithelial cells.
AB - In this review, we discuss evidence that supports the hypothesis that adrenergic
stimulation of transepithelial Na absorption across the alveolar epithelium
occurs indirectly by activation of apical Cl channels, resulting in
hyperpolarization and an increased driving force for Na uptake through amiloride
sensitive Na channels. This hypothesis differs from the prevailing idea that
adrenergic-receptor activation increases the open probability of Na channels,
leading to an increase in apical membrane Na permeability and an increase in Na
and fluid uptake from the alveolar space. We review results from cultured
alveolar epithelial cell monolayer experiments that show increases in apical
membrane Cl conductance in the absence of any change in Na conductance after
stimulation by selective beta-adrenergic-receptor agonists. We also discuss
possible reasons for differences in Na-channel regulation in cells grown in
monolayer culture compared with that in dissociated alveolar epithelial cells.
Finally, we describe some preliminary in vivo data that suggest a role for Cl
channel activation in the process of amiloride-sensitive alveolar fluid
absorption.
PMID- 10666107
TI - Effect of steroid on hyperoxia-induced ICAM-1 expression in pulmonary endothelial
cells.
AB - Intercellular adhesion molecule-1 (ICAM-1) of the vascular endothelium plays a
key role in the development of pulmonary oxygen toxicity. We studied the effect
of steroid on hyperoxia-induced ICAM-1 expression using cultured endothelial
cells in vitro. Human pulmonary artery endothelial cells (HPAECs) were cultured
to confluence, and then the monolayers were exposed to either control (21% O(2)
5% CO(2)) or hyperoxic (90% O(2)-5% CO(2)) conditions with and without a
synthetic glucocorticoid, methylprednisolone (MP). MP reduced hyperoxia-induced
ICAM-1 and ICAM-1 mRNA expression in a dose-dependent manner. Neutrophil adhesion
to hyperoxia-exposed endothelial cells was also inhibited by MP treatment. In
addition, MP attenuated hyperoxia-induced H(2)O(2) production in HPAECs as
assessed by flow cytometry. An electrophoretic mobility shift assay demonstrated
that hyperoxia activated nuclear factor-kappaB (NF-kappaB) but not activator
protein-1 (AP-1) and that MP attenuated hyperoxia-induced NF-kappaB activation
dose dependently. With Western immunoblot analysis, IkappaB-alpha expression was
decreased by hyperoxia and increased by MP treatment. These results suggest that
MP downregulates hyperoxia-induced ICAM-1 expression by inhibiting NF-kappaB
activation via increased IkappaB-alpha expression.
PMID- 10666108
TI - Hyperoxia synergistically increases TNF-alpha-induced interleukin-8 gene
expression in A549 cells.
AB - Interleukin (IL)-8 is an important mediator of acute lung injury. Hyperoxia
induces IL-8 production in some cell types, but its effect on IL-8 gene
expression in respiratory epithelium is not well described. In addition, IL-8
gene expression resulting from the combined effects of hyperoxia and
proinflammatory cytokines has not been well characterized. We treated cultured
respiratory epithelial-like cells (A549 cells) with hyperoxia alone, tumor
necrosis factor (TNF)-alpha alone, or the combination of TNF-alpha and hyperoxia
and evaluated IL-8 gene expression. Hyperoxia alone had a minimal effect on IL-8
gene expression, and TNF-alpha alone increased IL-8 gene expression in a time
dependent manner. In contrast, the combination of TNF-alpha and hyperoxia
synergistically increased IL-8 gene expression as measured by ELISA (TNF-alpha
alone for 24 h = 769 +/- 89 pg/ml vs. hyperoxia + TNF-alpha for 24 h = 1, 189 +/-
89 pg/ml) and Northern blot analyses. Experiments involving IL-8 promoter
reporter assays, electromobility shift assays, and Western blot analyses
demonstrated that hyperoxia augmented TNF-alpha-mediated activation of the IL-8
promoter by a nuclear factor (NF)-kappaB-dependent mechanism and increased the
duration of NF-kappaB nuclear translocation after concomitant treatment with TNF
alpha. Additional reporter gene assays demonstrated, however, that increased
activation of NF-kappaB does not fully account for the synergistic effect of
hyperoxia and that the NF-IL-6 site in the IL-8 promoter is also required for the
synergistic effect of hyperoxia. We conclude that hyperoxia alone has a minimal
effect on IL-8 gene expression but synergistically increases IL-8 gene expression
in the presence of TNF-alpha by a mechanism involving cooperative interaction
between the transcription factors NF-kappaB and NF-IL-6.
PMID- 10666109
TI - High K(+)-induced membrane depolarization attenuates endothelium-dependent
pulmonary vasodilation.
AB - Impairment of endothelium-dependent pulmonary vasodilation has been implicated in
the development of pulmonary hypertension. Pulmonary vascular smooth muscle cells
and endothelial cells communicate electrically through gap junctions; thus,
membrane depolarization in smooth muscle cells would depolarize endothelial
cells. In this study, we examined the effect of prolonged membrane depolarization
induced by high K(+) on the endothelium-dependent pulmonary vasodilation.
Isometric tension was measured in isolated pulmonary arteries (PA) from Sprague
Dawley rats, and membrane potential was measured in single PA smooth muscle
cells. Increase in extracellular K(+) concentration from 4.7 to 25 mM
significantly depolarized PA smooth muscle cells. The 25 mM K(+)-mediated
depolarization was characterized by an initial transient depolarization (5-15 s)
followed by a sustained depolarization that could last for up to 3 h. In
endothelium-intact PA rings, ACh (2 microM), levcromakalim (10 microM), and
nitroprusside (10 microM) reversibly inhibited the 25 mM K(+)-mediated
contraction. Functional removal of endothelium abolished the ACh-mediated
relaxation but had no effect on the levcromakalim- or the nitroprusside-mediated
pulmonary vasodilation. Prolonged ( approximately 3 h) membrane depolarization by
25 mM K(+) significantly inhibited the ACh-mediated PA relaxation (-55 +/- 4 vs.
29 +/- 2%, P < 0.001), negligibly affected the levcromakalim-mediated pulmonary
vasodilation (-92 +/- 4 vs. -95 +/- 5%), and slightly but significantly increased
the nitroprusside-mediated PA relaxation (-80 +/- 2 vs. 90 +/- 3%, P < 0. 05).
These data indicate that membrane depolarization by prolonged exposure to high
K(+) concentration selectively inhibited endothelium-dependent pulmonary
vasodilation, suggesting that membrane depolarization plays a role in the
impairment of pulmonary endothelial function in pulmonary hypertension.
PMID- 10666110
TI - PAF-induced synthesis of tetraenoic and pentaenoic leukotrienes in the isolated
rabbit lung.
AB - In an isolated rabbit lung model, we tested the hypothesis that platelet
activating factor (PAF)-induced leukotriene (LT) synthesis is critically
dependent on the free precursor fatty acid supply and the possible substitution
of arachidonic acid (AA) by eicosapentaenoic acid (EPA). To augment the
intravascular polymorphonuclear neutrophils (PMNs) in the isolated lung, human
PMNs were infused into the pulmonary artery. LTs and
hydroxyeicosatetra(penta)enoic acids were quantified with HPLC techniques.
Application of PAF (5 microM) or AA (10 microM) provoked the generation of
limited quantities of 4-series LTs and 5-hydroxyeicosatetraenoic acid (total sum
of 5-lipoxygenase products approximately 7 and approximately 27 pmol/ml in lungs
both with and without infused PMNs, respectively). Combined administration
amplified 5-lipoxygenase product formation, with a predominance of cysteinyl-LT
synthesis in lungs both without (total sum approximately 67 pmol/ml) and, much
more strikingly, with (total sum approximately 308 pmol/ml) an infusion of
neutrophils. EPA (10 microM) elicited exclusive generation of 5-series LTs and 5
hydroxyeicosapentaenoic acid (total sum approximately 82 pmol/ml). Dual
stimulation with PAF and EPA provoked amplification of EPA-derived 5-lipoxygenase
product formation, again with predominance of cysteinyl-LTs in lungs without
(total sum approximately 224 pmol/ml) and, in particular, with (total sum
approximately 545 pmol/ml) preceding microvascular PMN entrapment. Combined
application of PAF, AA, and EPA resulted in the synthesis of LTs derived from
both fatty acids, with a predominance of 5-series products. We conclude that the
PAF-evoked 5-lipoxygenase product formation in the neutrophil-harboring lung
capillary bed is critically dependent on intravascular precursor fatty acid
supply, with EPA representing the preferred substrate compared with AA. PMN
related transcellular eicosanoid synthesis is suggested to underlie the
predominant generation of cysteinyl-LTs. The supply of n-3 versus n-6 precursor
fatty acid may thus have a major impact on inflammatory mediator generation.
PMID- 10666111
TI - Decreased synthesis and vasodilation to nitric oxide in piglets with hypoxia
induced pulmonary hypertension.
AB - Nitric oxide (NO) is thought to play an important role in the regulation of
neonatal pulmonary vasculature. It has been suggested that neonates with
pulmonary hypertension have a defective NO pathway. Therefore, we measured in 1
day-old piglets exposed to hypoxia (fraction of inspired O(2) = 0.10) for 3 or 14
days to induce pulmonary hypertension 1) the activity of NO synthase (NOS) via
conversion of L-arginine to L-citrulline and the concentration of the NO
precursor L-arginine in isolated pulmonary vessels, 2) the vasodilator response
to the NO donor 3-morpholinosydnonimine-N-ethylcarbamide (SIN-1) and the cGMP
analog 8-bromo-cGMP in isolated perfused lungs, and 3) the production of cGMP in
response to SIN-1 in isolated perfused lungs. After 3 days of exposure to
hypoxia, endothelial NOS (eNOS) activity was unaffected, whereas, after 14 days
of hypoxia, eNOS activity was decreased in the cytosolic fraction of pulmonary
artery (P < 0.05) but not of pulmonary vein homogenates. Inducible NOS activity
was decreased in the cytosolic fraction of pulmonary artery homogenates after
both 3 (P < 0.05) and 14 (P < 0.05) days of hypoxia but was unchanged in
pulmonary veins. Pulmonary artery levels of L-arginine were unaffected by hypoxic
exposure. After 3 days of exposure to hypoxia, the reduction in the dilator
response to SIN-1 (P < 0.05) coincided with a decrease in cGMP production (P <
0.005), suggesting that soluble guanylate cyclase activity may be altered. When
the exposure was prolonged to 14 days, dilation to SIN-1 remained decreased (P <
0.05) and, although cGMP production normalized, the dilator response to 8-bromo
cGMP decreased (P < 0.05), suggesting that, after prolonged exposure to hypoxia,
cGMP-dependent mechanisms may also be impaired. In conclusion, neonatal hypoxia
induced pulmonary hypertension is associated with multiple disruptions in the NO
pathway.
PMID- 10666112
TI - cDNA-RDA of genes expressed in fetal and adult lungs identifies factors important
in development and function.
AB - The identification of genetic factors important in lung development and function
will help in understanding the underlying molecular mechanisms of respiratory
disease. Representational difference analysis of cDNA (cDNA-RDA) is a PCR-based
subtractive enrichment procedure for the isolation of differentially expressed
genes. We performed cDNA-RDA and isolated genes expressed more abundantly in
fetal and adult lungs. Fifty-four clones potentially representing genes with
higher transcript levels in the fetal lung were sequenced. Sequence similarity
searches indicated that these clones included 12 known genes, a discoidin-like
domain-containing gene, six expressed sequence tags (ESTs), and one novel
sequence. Fifty-six clones potentially representing genes expressed more
abundantly in the adult lung were also cloned and sequenced. Of these, 16 known
human genes were represented along with two sequences significantly similar to
known mouse genes and two novel sequences. Several of these known genes are
implicated in stress response and lung protection. Thus cDNA-RDA was successfully
used to isolate known and novel differentially expressed genes, which putatively
play an important role in human lung development.
PMID- 10666113
TI - Energy state, pH, and vasomotor tone during hypoxia in precontracted pulmonary
and femoral arteries.
AB - To assess effects of smooth muscle energy state and intracellular pH (pH(i)) on
pulmonary arterial tone during hypoxia, we measured ATP, phosphocreatine, P(i),
and pH(i) by (31)P-NMR spectroscopy and isometric tension in phenylephrine
contracted rings of porcine proximal intrapulmonary arteries. Hypoxia caused
early transient contraction followed by relaxation and late sustained
contraction. Energy state and pH(i) decreased during relaxation and recovered
toward control values during late contraction. Femoral arterial rings had higher
energy state and lower pH(i) under baseline conditions and did not exhibit late
contraction or recovery of energy state and pH(i) during hypoxia. In pulmonary
arteries, glucose-free conditions abolished late hypoxic contraction and recovery
of energy state and pH(i), but endothelial denudation abolished only late hypoxic
contraction. NaCN had little effect at 0. 1 and 1.0 mM but caused marked
vasorelaxation and decreases in energy state and pH(i) at 10 mM. These results
suggest that 1) regulation of tone, energy state, and pH(i) differed markedly in
pulmonary and femoral arterial smooth muscle, 2) hypoxic relaxation was mediated
by decreased energy state or pH(i) due to hypoxic inhibition of oxidative
phosphorylation, 3) recovery of energy state and pH(i) in hypoxic pulmonary
arteries was due to accelerated glycolysis mediated by mechanisms intrinsic to
smooth muscle, and 4) late hypoxic contraction in pulmonary arteries was mediated
by endothelial factors that required hypoxic recovery of energy state and pH(i)
for transduction in smooth muscle or extracellular glucose for production and
release by endothelium.
PMID- 10666114
TI - Phospholipid molecular species of bronchoalveolar lavage fluid after local
allergen challenge in asthma.
AB - Electrospray ionization mass spectrometry was used to quantify
phosphatidylcholine (PC) and phosphatidylglycerol (PG) molecular species in
bronchoalveolar lavage fluid (BALF) from control and mild asthmatic subjects
after local allergen challenge. BALF was obtained from 5 control and 13 asthmatic
subjects before and 24 h after segmental allergen and saline challenge. There
were no differences in the ratio of total PC to total PG or in the molecular
species composition of PC or PG between the asthmatic and control groups under
basal conditions. Allergen challenge in asthmatic but not in control volunteers
caused a significant increase in the PC-to-PG ratio because of increased
concentrations of PC species containing linoleic acid (16:0/18:2 PC, 18:0/18:2
PC, and 18:1/18:2 PC). These molecular species were characteristic of plasma PC
analyzed from the same subjects, strongly suggesting that the altered PC
composition in BALF in asthmatic subjects after allergen challenge was due to
infiltration of plasma lipoprotein, not to catabolism of surfactant phospholipid.
Interactions between surfactant and lipoprotein infiltrate may contribute to
surfactant dysfunction and potentiate disease severity in asthma.
PMID- 10666115
TI - Heme oxygenase-1 inhibits TNF-alpha-induced apoptosis in cultured fibroblasts.
AB - Heme oxygenase (HO)-1 catalyzes the oxidative cleavage of heme to yield equimolar
amounts of biliverdin, iron, and carbon monoxide. HO-1 is a stress response
protein, the induction of which is associated with protection against oxidative
stress. The mechanism(s) of protection is not completely elucidated, although it
is suggested that one or more of the catalytic by-products provide antioxidant
functions either directly or indirectly. The involvement of reactive oxygen
species in apoptosis raised the question of a possible role for HO-1 in
programmed cell death. Using the tetracycline-regulated expression system, we
show here that conditional overexpression of HO-1 prevents tumor necrosis factor
alpha-induced apoptosis in murine L929 fibroblasts. Inhibition of apoptosis was
not observed in the presence of tin protoporphyrin, a specific inhibitor of HO
activity, and in cells overexpressing antisense HO-1. Interestingly, exogenous
administration of a low concentration of carbon monoxide also prevented tumor
necrosis factor-alpha-induced apoptosis in L929 fibroblasts. Inhibition of tumor
necrosis factor-alpha-induced apoptosis by HO-1 overexpression was reversed by 1H
(1,2, 4)oxadiazolo(4,3-a)quinoxalin-1-one, an inhibitor of guanylate cyclase,
which is a target enzyme for carbon monoxide. Taken together, our data suggest
that the antiapoptotic effect of HO-1 may be mediated via carbon monoxide.
PMID- 10666116
TI - Electrical behavior of guinea pig tracheal smooth muscle.
AB - Intracellular recordings were taken from the smooth muscle of the guinea pig
trachea, and the effects of intrinsic nerve stimulation were examined.
Approximately 50% of the cells had stable resting membrane potentials of -50 +/-
1 mV. The remaining cells displayed spontaneous oscillations in membrane
potential, which were abolished either by blocking voltage-dependent Ca(2+)
channels with nifedipine or by depleting intracellular Ca(2+) stores with
ryanodine. In quiescent cells, stimulation with a single impulse evoked an
excitatory junction potential (EJP). In 30% of these cells, trains of stimuli
evoked an EJP that was followed by oscillations in membrane potential. Transmural
nerve stimulation caused an increase in the frequency of spontaneous
oscillations. All responses were abolished by the muscarinic-receptor antagonist
hyoscine (1 microM). In quiescent cells, nifedipine (1 microM) reduced EJPs by
30%, whereas ryanodine (10 microM) reduced EJPs by 93%. These results suggest
that both the release of Ca(2+) from intracellular stores and the influx of
Ca(2+) through voltage-dependent Ca(2+) channels are important determinants of
spontaneous and nerve-evoked electrical activity of guinea pig tracheal smooth
muscle.
PMID- 10666117
TI - Prenyltransferase inhibitors block superoxide production by pulmonary vascular
smooth muscle.
AB - We recently showed that the farnesyltransferase inhibitor FTI-277 blocks
interleukin 1beta (IL-1beta)-induced nitric oxide production in pulmonary
vascular smooth muscle cells (SMC), whereas the geranylgeranyltransferase
inhibitor GGTI-298 enhances this effect. Here we show that IL-1beta and platelet
derived growth factor (PDGF) stimulate superoxide production by pulmonary
vascular SMC and that this effect is blocked by both FTI-277 and GGTI-298,
suggesting that farnesylated and geranylgeranylated proteins are required for
superoxide production. We also show that FTI-277 and GGTI-298 block superoxide
production stimulated by constitutively active mutant H-Ras. Furthermore,
superoxide production by IL-1beta, PDGF factor, and constitutively activated Ras
is blocked by diphenyleneiodonium, implicating NAD(P)H oxidase as the generating
enzyme. Given the role of oxidant radicals in vascular reactivity and injury, the
action of both FTI-277 and GGTI-298 in suppressing superoxide generation by an
inflammatory cytokine as well as by a potent smooth muscle mitogen may be
therapeutically useful.
PMID- 10666118
TI - Epoxyeicosatrienoic acids constrict isolated pressurized rabbit pulmonary
arteries.
AB - Little information is available regarding the vasoactive effects of
epoxyeicosatrienoic acids (EETs) in the lung. We demonstrate that 5, 6-, 8,9-,
11,12-, and 14,15-EETs contract pressurized rabbit pulmonary arteries in a
concentration-dependent manner. Constriction to 5,6-EET methyl ester or 14,15-EET
is blocked by indomethacin or ibuprofen (10(-5) M), SQ-29548, endothelial
denuding, or submaximal preconstriction with the thromboxane mimetic U-46619.
Constriction of pulmonary artery rings to phenylephrine is blunted by treatment
with the epoxygenase inhibitor N-methylsulfonyl-6-(2
propargyloxyphenyl)hexanamide. Pulmonary arteries and peripheral lung microsomes
metabolize arachidonate to products that comigrate on reverse-phrase HPLC with
authentic regioisomers of 5,6-, 8,9-, 11,12-, and 14,15-EETs, but no
cyclooxygenase products of EETs could be demonstrated. Proteins of the CYP2B,
CYP2E, CYP2J, CYP1A, and CYP2C subfamilies are present in pulmonary artery and
peripheral lung microsomes. Constriction of isolated rabbit pulmonary arteries to
EETs is nonregioselective and depends on intact endothelium and cyclooxygenase,
consistent with the formation of a pressor prostanoid compound. These data raise
the possibility that EETs may contribute to regulation of pulmonary vascular
tone.
PMID- 10666119
TI - Substance P and neurokinin-1 receptor expression by intrinsic airway neurons in
the rat.
AB - Tachykinins and their receptors are involved in the amplification of inflammation
in the airways. We analyzed the expression of preprotachykinin-A (PPT-A) and
neurokinin-1 (NK-1) receptor genes by intrinsic airway neurons in the rat. We
also tested the hypothesis that PPT-A-encoded peptides released by these neurons
fulfill the requisite role of substance P in immune complex injury of the lungs.
We found that ganglion neurons in intact and denervated airways or in primary
culture coexpress PPT-A and NK-1 receptor mRNAs and their protein products.
Denervated ganglia from tracheal xenografts (nu/nu mice) or syngeneic lung grafts
had increased PPT-A mRNA contents, suggesting preganglionic regulation. Formation
of immune complexes in the airways induced comparable inflammatory injuries in
syngeneic lung grafts, which lack peptidergic sensory fibers, and control lungs.
The injury was attenuated in both cases by pretreatment with the NK-1 receptor
antagonist LY-306740. We conclude that tachykinins released by ganglia act as a
paracrine or autocrine signal in the airways and may contribute to NK-1 receptor
mediated amplification of immune injury in the lungs.
PMID- 10666120
TI - Brief perinatal hypoxia increases severity of pulmonary hypertension after
reexposure to hypoxia in infant rats.
AB - We hypothesized that disrupted alveolarization and lung vascular growth caused by
brief perinatal hypoxia would predispose infant rats to higher risk for
developing pulmonary hypertension when reexposed to hypoxia. Pregnant rats were
exposed to 11% inspired oxygen fraction (barometric pressure, 410 mmHg; inspired
oxygen pressure, 76 mmHg) for 3 days before birth and were maintained in hypoxia
for 3 days after birth. Control rats were born and raised in room air. At 2 wk of
age, rats from both groups were exposed to hypoxia for 1 wk or kept in room air.
We found that brief perinatal hypoxia resulted in a greater increase in right
ventricular systolic pressure and higher ratio of right ventricle to left
ventricle plus septum weights after reexposure to hypoxia after 2 wk of age.
Moreover, perinatal hypoxic rats had decreased radial alveolar counts and reduced
pulmonary artery density. We conclude that brief perinatal hypoxia increases the
severity of pulmonary hypertension when rats are reexposed to hypoxia. We
speculate that disrupted alveolarization and lung vascular growth following brief
perinatal hypoxia may increase the risk for severe pulmonary hypertension with
exposure to adverse stimuli later in life.
PMID- 10666121
TI - Pulmonary-specific expression of SP-D corrects pulmonary lipid accumulation in SP
D gene-targeted mice.
AB - Targeted disruption of the surfactant protein (SP) D (SP-D) gene caused a marked
pulmonary lipoidosis characterized by increased alveolar lung phospholipids,
demonstrating a previously unexpected role for SP-D in surfactant homeostasis. In
the present study, we tested whether the local production of SP-D in the lung
influenced surfactant content in SP-D-deficient [SP-D(-/-)] and SP-D wild-type
[SP-D(+/+)] mice. Rat SP-D (rSP-D) was expressed under control of the human SP-C
promoter, producing rSP-D, SP-D(+/+) transgenic mice. SP-D content in
bronchoalveolar lavage fluid was increased 30- to 50-fold in the rSP-D, SP-D(+/+)
mice compared with the SP-D(+/+) parental strain. Lung morphology, phospholipid
content, and surfactant protein mRNAs were unaltered by the increased
concentration of SP-D. Likewise, the production of endogenous mouse SP-D mRNA was
not perturbed by the SP-D transgene. rSP-D, SP-D(+/+) mice were bred to SP-D(-/-)
mice to assess whether lung-selective expression of SP-D might correct lipid
homeostasis abnormalities in the SP-D(-/-) mice. Selective expression of SP-D in
the respiratory epithelium had no adverse effects on lung function, correcting
surfactant phospholipid content and decreasing phosphatidylcholine incorporation
significantly. SP-D regulates surfactant lipid homeostasis, functioning locally
to inhibit surfactant phospholipid incorporation in the lung parenchyma and
maintaining alveolar phospholipid content in the alveolus. Marked increases in
biologically active tissue and alveolar SP-D do not alter lung morphology,
macrophage abundance or structure, or surfactant accumulation.
PMID- 10666122
TI - Estradiol improves pulmonary hemodynamics and vascular remodeling in perinatal
pulmonary hypertension.
AB - Partial ligation of the ductus arteriosus (DA) in the fetal lamb causes sustained
elevation of pulmonary vascular resistance (PVR) and hypertensive structural
changes in small pulmonary arteries, providing an animal model for persistent
pulmonary hypertension of the newborn. Based on its vasodilator and antimitogenic
properties in other experimental studies, we hypothesized that estradiol (E(2))
would attenuate the pulmonary vascular structural and hemodynamic changes caused
by pulmonary hypertension in utero. To test our hypothesis, we treated
chronically instrumented fetal lambs (128 days, term = 147 days) with daily
infusions of E(2) (10 microg; E(2) group, n = 6) or saline (control group, n = 5)
after partial ligation of the DA. We measured intrauterine pulmonary and systemic
artery pressures in both groups throughout the study period. After 8 days, we
delivered the study animals by cesarean section to measure their hemodynamic
responses to birth-related stimuli. Although pulmonary and systemic arterial
pressures were not different in utero, fetal PVR immediately before ventilation
was reduced in the E(2)-treated group (2.43 +/- 0.79 vs. 1.48 +/- 0.26 mmHg. ml(
1). min, control vs. E(2), P < 0.05). During the subsequent delivery study, PVR
was lower in the E(2)-treated group in response to ventilation with hypoxic gas
but was not different between groups with ventilation with 100% O(2). During
mechanical ventilation after delivery, arterial partial O(2) pressure was higher
in E(2) animals than controls (41 +/- 11 vs. 80 +/- 35 Torr, control vs. E(2), P
< 0. 05). Morphometric studies of hypertensive vascular changes revealed that
E(2) treatment decreased wall thickness of small pulmonary arteries (59 +/- 1 vs.
48 +/- 1%, control vs. E(2), P < 0.01). We conclude that chronic E(2) treatment
in utero attenuates the pulmonary hemodynamic and histological changes caused by
DA ligation in fetal lambs.
PMID- 10666123
TI - Hepatocyte growth factor is elevated in chronic lung injury and inhibits
surfactant metabolism.
AB - Adult respiratory distress syndrome may incorporate in its pathogenesis the
hyperplastic proliferation of alveolar epithelial type II cells and derangement
in synthesis of pulmonary surfactant. Previous studies have demonstrated that
hepatocyte growth factor (HGF) in the presence of serum is a potential mitogen
for adult type II cells (R. J. Panos, J. S. Rubin, S. A. Aaronson, and R. J.
Mason. J. Clin. Invest. 92: 969-977, 1993) and that it is produced by fetal
mesenchymal lung cells (J. S. Rubin, A. M.-L. Chan, D. P. Botarro, W. H. Burgess,
W. G. Taylor, A. C. Cech, D. W. Hirschfield, J. Wong, T. Miki, P. W. Finch, and
S. A. Aaronson. Proc. Natl. Acad. Sci. USA 88: 415-419, 1991). In these studies,
we expand on this possible involvement of HGF in chronic lung injury by showing
the following. First, normal adult lung fibroblasts transcribe only small amounts
of HGF mRNA, but the steady-state levels of this message rise substantially in
lung fibroblasts obtained from animals exposed to oxidative stress. Second,
inflammatory cytokines produced early in the injury stimulate the transcription
of HGF in isolated fibroblasts, providing a plausible mechanism for the increased
amounts of HGF seen in vivo. Third, HGF is capable of significantly inhibiting
the synthesis and secretion of the phosphatidylcholines of pulmonary surfactant.
Fourth, HGF inhibits the rate-limiting enzyme in de novo phosphatidylcholine
synthesis, CTP:choline-phosphate cytidylyltransferase (EC 2.7.7.15). Our data
indicate that fibroblast-derived HGF could be partially responsible for the
changes in surfactant dysfunction seen in adult respiratory distress syndrome,
including the decreases seen in surfactant phosphatidylcholines.
PMID- 10666124
TI - Maturational differences in hyperoxic AP-1 activation in rat lung.
AB - Immature organisms (neonates; <12 h old) have vastly differing responses to
hyperoxic injury than adults. A common feature of hyperoxic gene regulation is
involvement of activator protein (AP)-1. We evaluated lung AP-1 binding as well
as that of the AP-1 subunit proteins c-Fos, c-Jun, phosphorylated c-Jun, Jun B,
and Jun D after exposure to >95% O(2) for 3 days. Unlike adults, neonates showed
no increased AP-1 binding in hyperoxia despite a high affinity of the AP-1
binding complexes for phosphorylated c-Jun and Jun D as demonstrated by
supershift of these antibodies with the AP-1 complexes. Moreover, neonatal lungs
exhibited two distinguishable AP-1 binding complexes, whereas adult lungs had
one. In neonates, sequential immunoprecipitation revealed that the lower AP-1
complex was composed of proteins from both the Fos and Jun families, whereas the
upper complex consisted of Jun family proteins, with predominance of Jun D. In
adults, the single AP-1 complex appeared to involve other Fos or non-Fos or non
Jun family proteins as well. Neonatal lungs showed a higher level of Jun B and
Jun D immunoreactive proteins in both air and hyperoxia compared with those in
adult lungs. These results suggest that significant maturational differences in
lung AP-1 complexes exist and that these may explain transcriptional differences
in hyperoxic gene regulation.
PMID- 10666125
TI - Oxygen induction of epithelial Na(+) transport requires heme proteins.
AB - Fetal distal lung epithelial (FDLE) cells exposed to a postnatal O(2)
concentration of 21% have higher epithelial Na(+) channel (ENaC) mRNA levels and
Na(+) transport relative to FDLE cells grown in a fetal O(2) concentration of 3%.
To investigate the mechanism of this process, FDLE monolayers were initially
cultured in 3% O(2), and then some were switched to a 21% O(2) environment.
Incubation of FDLE cells with the iron chelator deferoxamine, CoCl(2), NiCl(2),
or an inhibitor of heme synthesis prevented or diminished the O(2) induction of
amiloride-sensitive short-circuit current in FDLE cells. Similarly, defer-
oxamine and cobalt prevented O(2)-induced ENaC mRNA expression. Exposure of FDLE
cells grown under hypoxic conditions to carbon monoxide increased both ENaC mRNA
expression and amiloride-sensitive short-circuit current. We therefore concluded
that induction of ENaC mRNA expression and amiloride-sensitive Na(+) transport in
FDLE cells by a physiological increase in O(2) concentration seen at birth
requires iron and heme proteins.
PMID- 10666126
TI - Hypoxia induces hexokinase II gene expression in human lung cell line A549.
AB - During adaptation to hypoxic and hyperoxic conditions, the genes involved in
glucose metabolism are upregulated. To probe involvement of the transcription
factor hypoxia-induced factor-1 (HIF-1) in hexokinase (HK) II expression in human
pulmonary cells, A549 cells and small-airway epithelial cells (SAECs) were
exposed to stimuli such as hypoxia, deferoxamine (DFO), and metal ions. The
largest increase in HK-II (20-fold for mRNA and 2.5-fold for enzymatic activity)
was observed in A549 cells when exposed to DFO. All stimuli selectively increased
the 5.5-kb rather than 4-kb transcript in A549 cells. Cycloheximide and
actinomycin D inhibited these responses. In addition, cells were transfected with
luciferase reporter constructs driven by the full-length HK-II 5'-regulatory
region (4.0 kb) or various deletions of that region. A549 cells transfected with
the 4.0-kb construct and exposed to hypoxia or DFO increased their luciferase
activity 7- and 10-fold, respectively, indicating that HK-II induction is, at
least in part, due to increased gene transcription. Sixty percent of the
inducible activity of the 4.0-kb construct was shown to reside within the
proximal 0.5 kb. Additionally, cotransfection with a stable HIF-1 mutant and the
4.0-kb promoter construct resulted in increased luciferase activity under
normoxic conditions. These results strongly suggest that HK-II is selectively
regulated in pulmonary cells by a HIF-1-dependent mechanism.
PMID- 10666127
TI - Gastrointestinal osmoreceptors and renal sodium excretion in humans.
AB - The hypothesis that natriuresis can be induced by stimulation of gastrointestinal
osmoreceptors was tested in eight supine subjects on constant sodium intake (150
mmol NaCl/day). A sodium load equivalent to the amount contained in 10% of
measured extracellular volume was administered by a nasogastric tube as isotonic
or hypertonic saline (850 mM). In additional experiments, salt loading was
replaced by oral water loading (3.5% of total body water). Plasma sodium
concentration increased after hypertonic saline (+3.1 +/- 0.7 mM), decreased
after water loading (-3.8 +/- 0.8 mM), and remained unchanged after isotonic
saline. Oncotic pressure decreased by 9.4 +/- 1.2, 3.7 +/- 1.2, and 10.7 +/-
1.3%, respectively. Isotonic saline induced an increase in renal sodium excretion
(104 +/- 15 to 406 +/- 39 micromol/min) that was larger than seen with hypertonic
saline (85 +/- 15 to 325 +/- 39 micromol/min) and water loading (88 +/- 11 to 304
+/- 28 micromol/min). Plasma ANG II decreased to 22 +/- 6, 35 +/- 6, and 47 +/-
5% of baseline after isotonic saline, hypertonic saline, and water loading,
respectively. Plasma atrial natriuretic peptide (ANP) concentrations and urinary
excretion rates of endothelin-1 were unchanged. In conclusion, stimulation of
osmoreceptors by intragastric infusion of hypertonic saline is not an important
natriuretic stimulus in sodium-replete subjects. The natriuresis after
intragastric salt loading was independent of ANP but can be explained by
inhibition of the renin-angiotensin system.
PMID- 10666128
TI - Pregnancy-associated reduction in vascular protein kinase C activity rebounds
during inhibition of NO synthesis.
AB - Vascular reactivity has been shown to be reduced during pregnancy and to be
enhanced during chronic inhibition of nitric oxide (NO) synthesis in pregnant
rats; however, the cellular mechanisms involved are unclear. The purpose of this
study was to investigate whether the pregnancy-induced changes in vascular
reactivity are associated with changes in the amount and/or activity of vascular
protein kinase C (PKC). Active stress as well as the amount and activity of PKC
was measured in deendothelialized thoracic aortic strips from virgin and pregnant
rats untreated or treated with the NO synthase inhibitor N(G)-nitro-L-arginine
methyl ester (L-NAME). In virgin rats, the PKC activator phorbol 12,13-dibutyrate
(PDBu, 10(-6) M) and the alpha-adrenergic agonist phenylephrine (Phe, 10(-5) M)
caused significant increases in active stress and PKC activity that were
inhibited by the PKC inhibitors staurosporine and calphostin C. Western blot
analysis in aortic strips of virgin rats showed significant amount of the alpha
PKC isoform. Both PDBu and Phe caused significant translocation of alpha-PKC from
the cytosolic to the particulate fraction. Compared with virgin rats, the PDBu-
and Phe-stimulated active stress and PKC activity as well as the amount and the
PDBu- and Phe-induced translocation of alpha-PKC were significantly reduced in
late pregnant rats but significantly enhanced in pregnant rats treated with L
NAME. The PDBu- and Phe-induced changes in active stress and the amount,
distribution, and activity of alpha-PKC in virgin rats treated with L-NAME were
not significantly different from that in virgin rats, whereas the changes in
pregnant rats treated with L-NAME + the NO synthase substrate L-arginine were not
significantly different from that in pregnant rats. These results provide
evidence that a PKC-mediated contractile pathway in vascular smooth muscle is
reduced during pregnancy and significantly enhanced during chronic inhibition of
NO synthesis. The results suggest that one possible mechanism of the pregnancy
associated changes in vascular reactivity may involve changes in the amount and
activity of the alpha-PKC isoform.
PMID- 10666129
TI - Accelerated contractile function and improved fatigue resistance of calf muscles
in newborn piglets with IUGR.
AB - Asymmetrical intrauterine growth restriction is denoted by disproportional
reduction of muscle mass compared with body weight reduction. However, effects on
contractile function or tissue development of skeletal muscles were not studied
until now. Therefore, isometric force output of serial-stimulated hindlimb
plantar flexors was measured in thiopental-anesthetized normal weight (NW) and
intrauterine growth-restricted (IUGR) 1-day-old piglets under conditions of
normal, reduced (aortic cross clamping), and reestablished (clamp release) blood
supply (measured by colored microspheres technique). Furthermore, muscle fiber
type distribution was determined after histochemical staining, specific muscle
force of the plantar flexors [quotient from absolute force divided by muscle mass
(N/g)] was calculated, and glycogen content and morphometric data of the
investigated muscles were estimated. Regional blood flow of hindlimb muscles was
similar in NW (6 +/- 2 ml. min(-1). 100 g(-1)) and IUGR piglets (8 +/- 1 ml. min(
1). 100 g(-1)). Isometric muscle contractions induced a marked increase in
regional blood flow of 4.1-fold in NW and 5-fold in stimulated hindlimb muscles
of IUGR piglets (baseline blood flow). Specific force of NW piglet muscles (5.2
+/- 0.2 N/g) was significantly lower than IUGR piglet muscles (6.1 +/- 0.6 N/g; P
< 0.05). Isometric muscle contractions (NW: 32.7 +/- 4.7 N; IUGR: 21.7 +/- 4.0 N)
resulted in a higher rate of force decrease in the calf muscles of NW animals
compared with IUGR piglets (8 +/- 2 vs. 3 +/- 1%; P < 0. 01). Functional
restoration of contractile performance after hindlimb recirculation was nearly
complete in IUGR piglets (98 +/- 1%), whereas in NW piglets a deficit of 9 +/- 3%
was found (P < 0. 01). Muscle fiber type estimation revealed an increased
proportion of type I fibers in flexor digitalis superficialis and gastrocnemius
medialis in IUGR piglets (P < 0.05). These data clearly indicate that contractile
function is accelerated in newborn IUGR piglets.
PMID- 10666130
TI - Influence of pontine A5 region on renal sympathetic nerve activity in conscious
rabbits.
AB - The effects of inhibiting the neural activity in the pontine A5 region on renal
sympathetic responses to baroreflex and/or chemoreflex activation were examined
in conscious rabbits. Eight rabbits were chronically instrumented with guide
cannulas for bilateral microinjections into the A5 area and an electrode for
measuring renal sympathetic nerve activity (RSNA). Baroreflex curves were
obtained under conditions of normoxia and hypoxia (10% O(2) + 3% CO(2)) after
injections into the A5 region of the GABA receptor agonist muscimol or vehicle
solution. Under normoxia, injections of muscimol did not affect resting RSNA or
blood pressure but increased the range of the RSNA baroreflex by 24 and 33% at
doses of 175 or 875 pmol, respectively, without affecting the reflex gain.
Hypoxia alone increased resting RSNA by 63%, as well as the range and gain of the
RSNA baroreflex by 53 and 89%, respectively, without affecting blood pressure.
However, under hypoxia, muscimol increased resting RSNA by 37 and 47% but
decreased the gain of the RSNA baroreflex by 19 and 34% at doses of 175 or 875
pmol, respectively, without affecting the reflex range. The effects of muscimol
on RSNA were mediated via changes in the amplitude of the sympathetic bursts,
whereas burst frequency remained unaffected. These data suggest that the A5
region has a little tonic influence on RSNA in conscious rabbits but serves to
limit the renal sympathetic responses to baroreceptor unloading or chemoreceptor
stimulation. The different changes in the baroreflex range and gain evoked by
muscimol under normoxia and hypoxia indicate that the A5 modulatory action may
depend on the activity of the afferent inputs to this region.
PMID- 10666131
TI - Spontaneous mutation in the db gene results in obesity and diabetes in CD-1
outbred mice.
AB - Five allelic mutants of the diabetes (db) gene have been previously described in
mice and rats causing obesity, infertility, and varying degrees of diabetes. We
have identified a new, spontaneous mutation resulting in obesity and diabetes in
a colony of CD-1 outbred mice, Mus musculus domesticus. Genetic complementation
studies indicated that the new mutation was an allele of the diabetes locus.
Sequence analysis of cDNA fragments showed a deletion of one G residue located in
exon 12 of the leptin receptor gene. The mutation, Lepr(db-NCSU), results in a
frameshift and reduces Lepr transcript levels 10-fold. Mutant mice drank up to
four times more water and were up to two times heavier than wild-type mice. Blood
glucose and plasma insulin and leptin concentrations were sexually dimorphic
among affected mice, suggesting an effect of sex steroids. Mortality of affected
males was 100% by 5 mo, whereas affected females survived up to 10 mo of age.
PMID- 10666132
TI - Effects of vagotomy on serum endotoxin, cytokines, and corticosterone after
intraperitoneal lipopolysaccharide.
AB - The vagus nerve appears to play a role in communicating cytokine signals to the
central nervous system, but the exact extent of its involvement in cytokine-to
brain communication remains controversial. Recently, subdiaphragmatic vagotomy
was shown to increase bacterial translocation across the gut barrier and thus may
cause endotoxin tolerance. The current experiment tested whether or not
vagotomized animals have similar systemic responses to endotoxin challenge as do
sham-operated animals. Subdiaphragmatically vagotomized and sham-operated animals
were injected intraperitoneally with one of three doses (10, 50, 100 microg/kg)
of lipopolysaccharide (LPS) or vehicle, and blood samples were taken at 15, 30,
60, 90, and 120 min after the injection. The intraperitoneal injection of LPS
increased circulating LPS levels at all time points examined. In addition, all
three doses of LPS significantly increased serum interleukin (IL)-1beta, IL-6,
and corticosterone in both control and vagotomized rats. In conclusion, vagotomy
itself has no marked effect on circulating endotoxin levels or the production of
IL-1beta, IL-6, or corticosterone in blood after an intraperitoneal injection of
LPS.
PMID- 10666133
TI - Angiotensin II indirectly vasoconstricts the ovine uterine circulation.
AB - The uterine vasculature of women and sheep predominantly expresses type 2 ANG II
receptors that do not mediate vasoconstriction. Although systemic ANG II
infusions increase uterine vascular resistance (UVR), this could reflect indirect
mechanisms. Thus we compared systemic and local intra-arterial ANG II infusions
in six near-term pregnant and five ovariectomized nonpregnant ewes to determine
how ANG II increases UVR. Systemic ANG II dose-dependently (P > 0.001) increased
arterial pressure (MAP) and UVR and decreased uterine blood flow (UBF) in
pregnant and nonpregnant ewes; however, nonpregnant responses exceeded pregnant
(P < 0.001). In contrast, local ANG II infusions at rates designed to achieve
concentrations in the uterine circulation comparable to those seen during
systemic infusions did not significantly decrease UBF in either group, and
changes in MAP and UVR were absent or markedly attenuated. When MAP rose during
local ANG II, which only occurred with doses > or =2 ng/ml, increases in MAP were
delayed more than twofold compared with responses during systemic ANG II
infusions and always preceded decreases in UBF, resembling that observed during
systemic ANG II infusions. These observations demonstrate attenuated uterine
vascular responses to systemic ANG II during pregnancy and suggest that systemic
ANG II may increase UVR through release of another potent vasoconstrictor(s) into
the systemic circulation.
PMID- 10666134
TI - Reduction of food intake by intestinal macronutrient infusion is not reversed by
NMDA receptor blockade.
AB - Rats increase their intake of food, but not water, after intraperitoneal
injection of MK-801, a noncompetitive antagonist of N-methyl-D-aspartate
activated ion channels. We hypothesized that MK-801 might enhance intake by
interfering with intestinal chemosensory signals. To test this hypothesis, we
examined the effect of the antagonist on 15% sucrose intake after an
intraduodenal infusion of maltotriose, oleic acid, or phenylalanine in both real-
and sham-feeding paradigms. MK-801 (100 microg/kg) significantly increased
sucrose intake regardless of the composition of the infusate during real feeding.
Furthermore, MK-801 had no effect on reduction of sucrose intake by intestinal
nutrient infusions in sham-feeding rats. These results indicate that MK-801 does
not increase meal size and duration by interfering with signals activated by
intestinal macronutrients.
PMID- 10666135
TI - Preinduction of heat shock proteins protects cardiac and hepatic functions
following trauma and hemorrhage.
AB - Although studies have shown that induction of the heat shock proteins (HSPs),
such as HSP-70, has various beneficial effects after ischemia-reperfusion, it
remains unknown whether prior induction of HSP-70 has any salutary effects on
cardiovascular and hepatocellular functions after trauma-hemorrhage and
resuscitation. Male rats were exposed to heat stress (41 degrees C, 15 min) and
then allowed to recover for 24 h at room temperature (21 degrees C). The rats
then underwent laparotomy (i.e., trauma induced) and were bled to and maintained
at a mean arterial pressure of 40 mmHg until 40% of the maximal shed blood volume
was returned in the form of Ringer lactate. Animals were then resuscitated with
four times the volume of shed blood with Ringer lactate over 60 min. The maximal
rate of the left ventricular pressure increase or decrease was measured up to 4 h
after resuscitation. Cardiac output, hepatocellular function, plasma levels of
tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) were determined
at 4 h after resuscitation. Cardiac and hepatic tissue were examined for HSP-70
by Western blot analysis. Left ventricular performance, cardiac output, and
hepatocellular function decreased significantly following trauma-hemorrhage.
Plasma levels of TNF-alpha and IL-6 were also significantly increased. However,
prior heat stress attenuated cardiovascular and hepatocellular dysfunction,
decreased circulating levels of proinflammatory cytokines following trauma
hemorrhage, and was associated with an increased abundance of HSP-70 in the heart
and liver. Our data, therefore, suggest that preinduction of HSP-70 protects
cardiovascular and hepatocellular functions following trauma-hemorrhage and
resuscitation.
PMID- 10666136
TI - Effects of intraduodenal glucose and fructose on antropyloric motility and
appetite in healthy humans.
AB - Oral fructose empties from the stomach more rapidly and may suppress food intake
more than oral glucose. The purpose of the study was to evaluate the effects of
intraduodenal infusions of fructose and glucose on antropyloric motility and
appetite. Ten healthy volunteers were given intraduodenal infusions of 25%
fructose, 25% glucose, or 0.9% saline (2 ml/min for 90 min). Antropyloric
pressures, blood glucose, and plasma insulin, gastric inhibitory peptide (GIP),
and glucagon-like peptide-1 (GLP-1) were measured concurrently; a buffet meal was
offered at the end of the infusion. Intraduodenal fructose and glucose suppressed
antral waves (P < 0. 0005 for both), stimulated isolated pyloric pressure waves
(P < 0.05 for both), and increased basal pyloric pressure (P = 0.10 and P < 0.
05, respectively) compared with saline, without any significant difference
between them. Intraduodenal glucose increased blood glucose (P < 0.0005), as well
as plasma insulin (P < 0.0005) and GIP (P < 0.005) more than intraduodenal
fructose, whereas there was no difference in the GLP-1 response. Intraduodenal
fructose suppressed food intake compared with saline (P < 0.05) and glucose (P =
0.07). We conclude that, when infused intraduodenally at 2 kcal/min for 90 min 1)
fructose and glucose have comparable effects on antropyloric pressures, 2)
fructose tends to suppress food intake more than glucose, despite similar GLP-1
and less GIP release, and 3) GIP, rather than GLP-1, probably accounts for the
greater insulin response to glucose than fructose.
PMID- 10666137
TI - Stress alters cutaneous permeability barrier homeostasis.
AB - Recent studies have shown that psychological stress can influence cutaneous
barrier function, suggesting that this form of stress could trigger or aggravate
skin disease. In the present study, we demonstrate that transfer of hairless mice
to a different cage delays barrier recovery rates. Pretreatment with a
phenothiazine sedative, chlorpromazine, before transfer of animals restored the
kinetics of barrier recovery toward normal, suggesting that psychological stress
is the basis for this alteration in barrier homeostasis. To determine the
mechanism linking psychological stress to altered barrier recovery, we first
demonstrated that plasma corticosterone levels increase markedly after transfer
of animals to new cages and that pretreatment with chlorpromazine blocks this
increase. Second, we demonstrated that the systemic administration of
corticosterone delays barrier recovery. Finally, we demonstrated that
pretreatment with the glucocorticoid receptor antagonist RU-486 blocks the delay
in barrier recovery produced by systemic corticosterone, change of cage, or
immobilization. These results suggest that psychological stress stimulates
increased production of glucocorticoids, which, in turn, adversely affects
permeability barrier homeostasis.
PMID- 10666138
TI - Daytime naps in darkness phase shift the human circadian rhythms of melatonin and
thyrotropin secretion.
AB - To systematically determine the effects of daytime exposure to sleep in darkness
on human circadian phase, four groups of subjects participated in 4-day studies
involving either no nap (control), a morning nap (0900-1500), an afternoon nap
(1400-2000), or an evening nap (1900-0100) in darkness. Except during the
scheduled sleep/dark periods, subjects remained awake under constant conditions,
i.e., constant dim light exposure (36 lx), recumbence, and caloric intake. Blood
samples were collected at 20-min intervals for 64 h to determine the onsets of
nocturnal melatonin and thyrotropin secretion as markers of circadian phase
before and after stimulus exposure. Sleep was polygraphically recorded. Exposure
to sleep and darkness in the morning resulted in phase delays, whereas exposure
in the evening resulted in phase advances relative to controls. Afternoon naps
did not change circadian phase. These findings indicate that human circadian
phase is dependent on the timing of darkness and/or sleep exposure and that
strategies to treat circadian misalignment should consider not only the timing
and intensity of light, but also the timing of darkness and/or sleep.
PMID- 10666139
TI - Type of negative feedback controlling sucrose ingestion depends on sucrose
concentration.
AB - The sham intake of concentrated, but not weak, milk solutions requires up to
three sham-feeding tests for intake to reach maximum (7). It is well known that
the sham intake of concentrated (0.8 M) sucrose requires three or more sham
feeding tests to reach its maximum (4, 6, 17), but it is not known if this occurs
with weaker sucrose solutions. We investigated this question by measuring the
sham intake of seven concentrations of sucrose (0.025, 0.05, 0.1, 0. 2, 0.4, 0.6,
and 0.8 M) during five sham-feeding tests. Sham intake of the three highest
concentrations required up to three sham-feeding tests to reach maximum. Sham
intake of the four lowest concentrations reached maximum in the first sham
feeding test. Our results show that the type of negative feedback that controls
the intake of sucrose depends on its concentration. With weak solutions, intake
is limited by a single direct, physiological, negative-feedback signal. When
concentrated solutions are ingested, intake is controlled jointly by a direct
physiological signal operating in conjunction with a labile one that loses its
effectiveness with sham-feeding experience.
PMID- 10666140
TI - Dexfenfluramine and norfenfluramine: comparison of mechanism of action in feeding
and brain Fos-ir studies.
AB - Dexfenfluramine (dF) and dexnorfenfluramine (dNF), its metabolite, are anorectic
agents that release serotonin (5-HT) and may have a direct postsynaptic action.
The effects on the anorectic effects of dF and dNF of either acute (p
chlorophenylalanine, PCPA) or chronic (5,7-dihydroxytryptamine, 5,7-DHT) brain 5
HT depletions were studied in rats and compared with the actions of a 5-HT uptake
inhibitor (fluoxetine) and 5-HT(1B/2C) receptor agonists [1-(3-trifluoromethyl
phenyl)-piperazine and 1-(3-chlorophenyl) piperazine]. The anorexia caused by
these agonists was enhanced in rats with 5,7-DHT lesions, possibly a result of
receptor supersensitivity. In contrast, fluoxetine anorexia was somewhat reduced
in one study and was unchanged in a second. Both dF and dNF anorexias were
enhanced in rats with 5,7-DHT lesions. In contrast, the anorectic effects of
either dF or dNF were unchanged in PCPA-treated rats relative to controls.
Compared with controls, 5, 7-DHT-lesion rats showed greatly increased dF- and dNF
induced Fos-like immunoreactivity (ir) in the paraventricular (PVN) and
supraoptic (SON) hypothalamic nuclei, and in the median preoptic area (MnPO), but
were similar to controls in most other areas. PCPA pretreatment increased dF- and
dNF-induced Fos-ir in the PVN, SON, and MnPO. In controls, equianorectic doses of
dF and dNF induced Fos-ir in similar brain regions, but dNF produced relatively
larger effects than dF in SON, PVN, and MnPO. The data are discussed in terms of
multiple pathways in the anorectic actions of dF and dNF.
PMID- 10666141
TI - Interstitial K(+) in human skeletal muscle during and after dynamic graded
exercise determined by microdialysis.
AB - Interstitial K(+) concentrations were measured during one-legged knee-extensor
exercise by use of microdialysis with probes inserted in the vastus lateralis
muscle of the subjects. K(+) in the dialysate was measured either by flame
photometry or a K(+)-sensitive electrode placed in the perfusion outlet. The
correction for fractional K(+) recovery was based on the assumption of identical
fractional thallium loss. The interstitial K(+) was 4. 19 +/- 0.09 mM at rest and
increased to 6.17 +/- 0.19, 7.48 +/- 1.18, and 9.04 +/- 0.74 mM at 10, 30, and 50
W exercise, respectively. The individual probes demonstrated large variations in
interstitial K(+), and values >10 mM were obtained. The observed interstitial
K(+) was markedly higher than previously found for venous K(+) concentrations at
similar work intensities. The present data support a potential role for
interstitial K(+) in regulation of blood flow and development of fatigue.
PMID- 10666142
TI - Sodium intake is increased by social stress and the Y chromosome and reduced by
clonidine.
AB - The objectives were to determine 1) if female rats have higher Na intake than
males and if social stress increases Na intake, 2) if the sympathetic nervous
system (SNS) mediates the stress effects and the gender effect, and 3) if the Y
chromosome (Yc) from a hypertensive father increases Na intake. Four rat strains
(n = 10/group) of both sexes were used: 1) Wistar Kyoto normotensive (WKY), 2) an
F(16) backcross with a Yc from a hypertensive father (SHR/y), 3) spontaneously
hypertensive rat (SHR), and 4) an F(16) backcross with a Yc from a normotensive
father (SHR/a). Females showed greater baseline Na intake than males
(hypertensive strains), intruder stress increased Na intake, and clonidine
decreased Na intake, but not in WKY or SHR females. SHR/y males had higher
baseline Na intake compared with WKY males. In conclusion, the higher Na intake
in females during baseline and stress was partially mediated through the SNS in
hypertensive strains and the SHR Yc was partially responsible for the increased
Na intake in SHR/y and SHR males compared with WKY.
PMID- 10666143
TI - Aminopeptidase-A. I. CDNA cloning and expression and localization in rat tissues.
AB - Aminopeptidase-A (APA) is an ectoenzyme that selectively hydrolyzes acidic
residues from the amino terminus of oligopeptides, including biologically active
[Asp(1)]ANG II and [Asp(1)]CCK-8. We sought to characterize rat APA by cDNA
cloning and expression and to determine its tissue distribution by in situ
hybridization and immunohistochemistry. Sequence analysis of overlapping cDNA
clones isolated from rat kidney cDNA libraries indicated that the full-length
cDNA encoded a 945-amino acid protein with a predicted molecular mass of 108 kDa;
the size was confirmed by in vitro translation of a full-length cDNA construct.
Transient transfection of the full-length cDNA construct in mammalian cells
yielded a protein approximately 140 kDa in size, a size that agrees with the
immunoblots of APA from rat tissue and is consistent with APA being known as a
glycosylated protein. Tissue APA activity and mRNA expression were highest in the
kidney and ileum. Localization of APA by in situ hybridization and
immunohistochemistry indicated that, with the exception of the kidney and ileum,
where APA was localized to the luminal brush border of proximal tubules and
enterocytes, respectively, APA was associated with either capillaries or the
lining of sinusoids. Areas known to be physiological targets for ANG II,
including glomeruli, the zona glomerulosa, and anterior pituitary, had high
levels of APA. The localization pattern suggests that APA may subserve multiple
functions, i.e., a generalized role in peptide scavenging and perhaps a more
specific role in metabolism of circulating or locally produced ANG II or CCK-8.
PMID- 10666144
TI - Aminopeptidase-A. II. Genomic cloning and characterization of the rat promoter.
AB - Aminopeptidase-A (APA) has a widespread tissue distribution consistent with a
role in the metabolism of circulating or locally produced ANG II or CCK-8. APA is
also highly expressed in pre-B lymphocytes, but its role in lymphoid cell
development is unknown. To begin to understand the basis for cell-specific
regulation of APA expression, we sought to clone and characterize the rat gene
promoter. Screening of a rat genomic library with a partial rat APA cDNA resulted
in isolation of a 12-kb clone found to contain the first exon and >3 kb of 5'
flanking sequence. Primer extension of rat kidney mRNA indicated that the major
transcription start site was 312 bp upstream of the translation start codon and
22 bp downstream from a TATA box. Constructs containing portions of the 5'
flanking region placed upstream of a chloramphenicol acetyltransferase reporter
gene indicated that expression was cell specific and that high activity could be
obtained with constructs containing as little as 110 bp of 5'-flanking region
sequence. We further identified an upstream regulatory element between -1063 and
348 that suppressed transcription in a cell-specific manner. This element (termed
upstream suppressor of APA, or USA) also suppressed transcription of a
heterologous promoter. These results indicate that the organization and
regulation of the rat APA is not consistent with it being a housekeeping gene and
further suggest that rat APA gene transcription might be regulated through the
presence of a novel strong upstream suppressor element.
PMID- 10666145
TI - Chronic infusion of norepinephrine into the VMH of normal rats induces the obese
glucose-intolerant state.
AB - Increases in ventromedial hypothalamic (VMH) norepinephrine (NE) levels and/or
activities have been observed in a variety of animal models of the obese insulin
resistant condition. This study examined the metabolic effects of chronic NE
infusion (25 nmol/h) into the unilateral VMH of normal rats. Within 4 days, VMH
NE infusion significantly increased plasma insulin (140%), glucagon (45%), leptin
(300%), triglyceride (100%), abdominal fat pad weight (50%), and white adipocyte
lipogenic (100%) and lipolytic (100%) activities relative to vehicle-infused
rats. Furthermore, isolated islet insulin secretory response to glucose (15 mM)
within 4 days of such treatment was increased over twofold (P < 0.05). Among
treated animals, fat stores continued to increase over time and plateaued at
approximately 2 wk (3-fold increase), remaining elevated to the end of the study
(5 wk). By week 4 of treatment, NE infusion induced glucose intolerance as
evidenced by a 32% increase in plasma glucose total area under the glucose
tolerance test curve (P < 0.01). Whole body fat oxidation rate measured after 5
wk of infusion was significantly increased among treated animals as evidenced by
a reduced respiratory quotient (0.87 +/- 0.01) relative to controls (0. 90 +/-
0.01). VMH NE infusion induced hyperphagia (30%) only during the first week and
did not affect body weight over the 5-wk period. Increases in VMH NE activity
that are common among obese insulin-resistant animal models can cause the
development of this obese glucose-intolerant (metabolic) syndrome.
PMID- 10666146
TI - Baroreflex control of muscle sympathetic nerve activity after 120 days of 6
degrees head-down bed rest.
AB - To examine how long-lasting microgravity simulated by 6 degrees head-down bed
rest (HDBR) induces changes in the baroreflex control of muscle sympathetic nerve
activity (MSNA) at rest and changes in responses of MSNA to orthostasis, six
healthy male volunteers (range 26-42 yr) participated in Valsalva maneuver and
head-up tilt (HUT) tests before and after 120 days of HDBR. MSNA was measured
directly using a microneurographic technique. After long-term HDBR, resting
supine MSNA and heart rate were augmented. The baroreflex slopes for MSNA during
Valsalva maneuver (in supine position) and during 60 degrees HUT test, determined
by least-squares linear regression analysis, were significantly steeper after
than before HDBR, whereas the baroreflex slopes for R-R interval were
significantly flatter after HDBR. The increase in MSNA from supine to 60 degrees
HUT was not different between before and after HDBR, but mean blood pressure
decreased in 60 degrees HUT after HDBR. In conclusion, the baroreflex control of
MSNA was augmented, whereas the same reflex control of R-R interval was
attenuated after 120 days of HDBR.
PMID- 10666147
TI - Effects of a unique conjugate of alpha-lipoic acid and gamma-linolenic acid on
insulin action in obese Zucker rats.
AB - The purpose of this study was to assess the individual and interactive effects of
the antioxidant alpha-lipoic acid (LPA) and the n-6 essential fatty acid gamma
linolenic acid (GLA) on insulin action in insulin-resistant obese Zucker rats.
LPA, GLA, and a unique conjugate consisting of equimolar parts of LPA and GLA
(LPA-GLA) were administered for 14 days at 10, 30, or 50 mg. kg body wt(-1). day(
1). Whereas LPA was without effect at 10 mg/kg, at 30 and 50 mg/kg it elicited
23% reductions (P < 0.05) in the glucose-insulin index (the product of glucose
and insulin areas under the curve during an oral glucose tolerance test and an
index of peripheral insulin action) that were associated with significant
increases in insulin-mediated (2 mU/ml) glucose transport activity in isolated
epitrochlearis (63-65%) and soleus (33-41%) muscles. GLA at 10 and 30 mg/kg
caused 21-25% reductions in the glucose-insulin index and 23-35% improvements in
insulin-mediated glucose transport in epitrochlearis muscle. The beneficial
effects of GLA disappeared at 50 mg/kg. At 10 and 30 mg/kg, the LPA-GLA conjugate
elicited 29 and 38% reductions in the glucose-insulin index. These LPA-GLA
induced improvements in whole body insulin action were accompanied by 28-63 and
38-57% increases in insulin-mediated glucose transport in epitrochlearis and
soleus muscles and resulted from the additive effects of LPA and GLA. At 50
mg/kg, the metabolic improvements due to LPA-GLA were substantially reduced. In
summary, these results indicate that the conjugate of the antioxidant LPA and the
n-6 essential fatty acid GLA elicits significant dose-dependent improvements in
whole body and skeletal muscle insulin action on glucose disposal in insulin
resistant obese Zucker rats. Moreover, these actions of LPA-GLA are due to the
additive effects of its individual components.
PMID- 10666148
TI - Effects of endothelin-1 and homologous trout endothelin on cardiovascular
function in rainbow trout.
AB - The cardiovascular effects of endothelin (ET)-1 and the recently sequenced
homologous trout ET were examined in unanesthetized trout, and vascular
capacitance curves were constructed to evaluate the responsiveness of the venous
system to ET-1. A bolus dose of 667 pmol/kg ET-1 doubled ventral aortic pressure;
produced a triphasic pressor-depressor-pressor response in dorsal aortic pressure
(P(DA)); increased central venous pressure, gill resistance, and systemic
resistance; and decreased cardiac output, heart rate, and stroke volume. These
responses were dose dependent. Bolus injection of trout ET (333 or 1,000 pmol/kg)
produced essentially identical, dose-dependent cardiovascular responses as ET-1.
Dorsal aortic infusion of 1 and 3 pmol. kg(-1). min(-1) ET-1 and central venous
infusion into the ductus Cuvier of 0.3 and 1 pmol. kg(-1). min(-1) produced
similar dose-dependent cardiovascular responses, although the increase in P(DA)
became monophasic. The heightened sensitivity to central venous infusion was
presumably due to the more immediate exposure of the branchial vasculature to the
peptide. Infusion of 1 pmol. kg(-1). min(-1) ET-1 decreased vascular compliance
but had no effect on unstressed blood volume. These results show that ETs affect
a variety of cardiovascular functions in trout and that branchial vascular
resistance and venous compliance are especially sensitive. The multiplicity of
effectors stimulated by ET suggests that this peptide was extensively integrated
into cardiovascular function early on in vertebrate phylogeny.
PMID- 10666149
TI - Arterial baroreceptors control plasma vasopressin responses to graded hypotension
in conscious dogs.
AB - We studied the role of cardiac and arterial baroreceptors in the reflex control
of arginine vasopressin (AVP) and renin secretion during graded hypotension in
conscious dogs. The dogs were prepared with Silastic cuffs on the thoracic
inferior vena cava and catheters in the pericardial space. Each experiment
consisted of a control period followed by four periods of inferior vena caval
constriction, during which mean arterial pressure (MAP) was reduced in increments
of approximately 10 mmHg. The hormonal responses were measured in five dogs under
four treatment conditions: 1) intact, 2) acute cardiac denervation (CD) by
intrapericardial infusion of procaine, 3) after sinoaortic denervation (SAD), and
4) during combined SAD+CD. The individual slopes relating MAP to plasma AVP and
plasma renin activity (PRA) were used to compare the treatment effects using a 2
x 2 factorial analysis. There was a significant (P < 0.01) effect of SAD on the
slope relating plasma AVP to MAP but no effect of CD and no SAD x CD interaction.
In contrast, the slope relating PRA and MAP was increased (P < 0.05) by SAD but
was not affected by CD. These results support the hypothesis that stimulation of
AVP secretion in response to graded hypotension is primarily driven by unloading
arterial baroreceptors in the dog.
PMID- 10666150
TI - Metabolic control of food intake and estrous cycles in syrian hamsters. I. Plasma
insulin and leptin.
AB - The "adipostat hypothesis" refers to the idea that circulating hormone
concentrations reflect levels of body adiposity and act as signals to control
food intake and reproduction. Implicit in the adipostatic hypothesis are the
following two assumptions: 1) plasma levels of adipostatic hormones accurately
reflect body fat content and 2) decreased plasma concentrations of adipostatic
hormones necessarily result in increased food intake and inhibited reproductive
processes. The present experiments are designed to test these assumptions. Fat
and lean Syrian hamsters were either fasted for 12, 24, 36, or 48 h or allowed ad
libitum access to food. Contrary to the first assumption, plasma leptin and
insulin levels in fat hamsters dropped dramatically by 12 h after the start of a
fast, with no significant change in body fat content and no postfast hyperphagia.
Lean hamsters showed anestrus after a 48-h fast but not after a 24-h fast.
Contrary to the second assumption of the lipostatic hypothesis, lean hamsters
fasted for 24 h and then refed for the next 24 h had leptin levels that were not
significantly elevated compared with those of 48-h-fasted hamsters. Thus, in
adult female Syrian hamsters, plasma leptin concentrations do not accurately
reflect body fat content under all conditions; normal estrous cyclicity does not
necessarily require plasma leptin concentrations higher than those of fasted
hamsters; and decreased plasma leptin levels do not result in increased food
intake.
PMID- 10666151
TI - Development of the pulmonary surfactant system in two oviparous vertebrates.
AB - In birds and oviparous reptiles, hatching is often a lengthy and exhausting
process, which commences with pipping followed by lung clearance and pulmonary
ventilation. We examined the composition of pulmonary surfactant in the
developing lungs of the chicken, Gallus gallus, and of the bearded dragon, Pogona
vitticeps. Lung tissue was collected from chicken embryos at days 14, 16, 18
(prepipped), and 20 (postpipped) of incubation and from 1 day and 3 wk posthatch
and adult animals. In chickens, surfactant protein A mRNA was detected using
Northern blot analysis in lung tissue at all stages sampled, appearing relatively
earlier in development compared with placental mammals. Chickens were lavaged at
days 16, 18, and 20 of incubation and 1 day posthatch, whereas bearded dragons
were lavaged at day 55, days 57-60 (postpipped), and days 58-61 (posthatched). In
both species, total phospholipid (PL) from the lavage increased throughout
incubation. Disaturated PL (DSP) was not measurable before 16 days of incubation
in the chick embryo nor before 55 days in bearded dragons. However, the
percentage of DSP/PL increased markedly throughout late development in both
species. Because cholesterol (Chol) remained unchanged, the Chol/PL and Chol/DSP
ratios decreased in both species. Thus the Chol and PL components are
differentially regulated. The lizard surfactant system develops and matures over
a relatively shorter time than that of birds and mammals. This probably reflects
the highly precocial nature of hatchling reptiles.
PMID- 10666152
TI - Effect of NPY in the hypothalamic paraventricular nucleus on uncoupling proteins
1, 2, and 3 in the rat.
AB - Neuropeptide Y (NPY) injected into the hypothalamic paraventricular nucleus (PVN)
stimulates feeding and decreases uncoupling protein (UCP)-1 mRNA in brown adipose
tissue (BAT). The present studies were undertaken to determine whether UCP-2 in
white adipose tissue (WAT) and UCP-3 in muscle are regulated by NPY in the PVN.
PVN-cannulated male Sprague-Dawley rats were injected with either saline or NPY
(PVN, 117 pmol, 0.5 microl) every 6 h for 24 h. NPY in the PVN stimulated feeding
and decreased UCP-1 mRNA in BAT independent of NPY-induced feeding. UCP-2 mRNA in
WAT was unchanged by NPY. In acromiotrapezius muscle, NPY decreased UCP-3 mRNA,
but this was reversed by restricting food intake to control levels. In biceps
femoris muscle, NPY alone had no effect on UCP-3 mRNA, but UCP-3 mRNA was
significantly increased in the NPY-treated rats that were restricted to control
levels of intake. These results suggest that UCP-2 in WAT and UCP-3 in muscle are
not subject to specific regulation by NPY in the PVN.
PMID- 10666153
TI - Regional effect of naltrexone in the nucleus of the solitary tract in blockade of
NPY-induced feeding.
AB - Naltrexone (NLTX) in the nucleus of the solitary tract (NTS) decreases feeding
induced by neuropeptide Y (NPY) in the paraventricular nucleus (PVN). We sought
to determine the NTS region most sensitive to NLTX blockade of PVN NPY-induced
feeding. Male Sprague-Dawley rats were fitted with two cannulas; one in the PVN
and one in a hindbrain region: caudal, medial, or rostral NTS or 1 mm outside the
NTS. Animals received NLTX (0, 1, 3, 10, and 30 microg in 0.3 microl) into the
hindbrain region just prior to PVN NPY (0.5 microg, 0.3 microl) or artificial
cerebrospinal fluid (0.3 microl). Food intake was measured at 2 h following
injection. PVN NPY stimulated feeding, and NLTX in the medial NTS significantly
decreased NPY-induced feeding at 2 h, whereas administration of NLTX in the other
hindbrain regions did not significantly influence PVN NPY induced feeding. These
data suggest that opioid receptors in the medial NTS are most responsive to
feeding signals originating in the PVN after NPY stimulation.
PMID- 10666154
TI - Lower calorie intake enhances muscle insulin action and reduces hexosamine
levels.
AB - Previous studies have demonstrated enhanced insulin sensitivity in calorie
restricted [CR, fed 60% ad libitum (AL) one time daily] compared with AL-fed
rats. To evaluate the effects of reduced food intake, independent of temporal
differences in consumption, we studied AL (unlimited food access)-fed and CR (fed
one time daily) rats along with groups temporally matched for feeding [fed 3
meals (M) daily]: MAL and MCR, eating 100 and 60% of AL intake, respectively.
Insulin-stimulated glucose transport by isolated muscle was increased in MCR and
CR vs. AL and MAL; there was no significant difference for MCR vs. CR or MAL vs.
AL. Intramuscular triglyceride concentration, which is inversely related to
insulin sensitivity in some conditions, did not differ among groups. Muscle
concentration of UDP-N-acetylhexosamines [end products of the hexosamine
biosynthetic pathway (HBP)] was lower in MCR vs. MAL despite unaltered glutamine
fructose-6-phosphate aminotransferase activity (rate-limiting enzyme for HBP).
These results indicate that the CR-induced increase in insulin-stimulated glucose
transport in muscle is attributable to an altered amount, not timing, of food
intake and is independent of lower triglyceride concentration. They further
suggest that enhanced insulin action might involve changes in HBP.
PMID- 10666155
TI - Tissue hypoxygenation activates the adrenomedullin system in vivo.
AB - Our study aimed to investigate the influence of tissue hypo-oxygenation on the
adrenomedullin (ADM) system in vivo. For this purpose, male Sprague-Dawley rats
were exposed to normobaric hypoxia (8% oxygen) or to functional anemia [0.1%
carbon monoxide (CO)] or to cobalt chloride (60 mg/kg) for 6 h. Messenger RNA
levels for ADM and its receptor (ADM-R) were assessed in diverse organs by RNase
protection assay. Additionally, ADM protein concentrations in these organs, as in
plasma, were determined by a RIA. We found that ADM mRNA abundance increased in
response to hypoxia and to CO inhalation up to 15-fold in all organs examined.
Similarly, ADM-R mRNA abundance increased during hypoxia and CO inhalation in all
organs examined with exception of the liver. The effects of hypoxia and of CO
inhalation on ADM and ADM-R mRNAs were mimicked by injection of cobaltous
chloride. Hypoxia also significantly increased ADM protein content in all organs,
and plasma levels of ADM rose twofold in response to hypoxia and CO inhalation.
These findings indicate that tissue hypoxia leads to a widespread activation of
the ADM system, which comprises a parallel stimulation of ADM and ADM receptor
mRNA as enhanced ADM protein synthesis and secretion. The ADM system may,
therefore, play a significant role in the physiological response to tissue
hypoxia. It appears that ADM and ADM-R belong to the family of classic oxygen
regulated genes, which are activated by a decrease of the pericellular oxygen
tension through the same intracellular signaling cascade.
PMID- 10666156
TI - AMPA glutamate receptors and respiratory control in the developing rat: anatomic
and pharmacological aspects.
AB - The developmental role of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate
(AMPA) glutamate receptors in respiratory regulation remains undefined. To study
this issue, minute ventilation (V(E)) was measured in 5-, 10-, and 15-day-old
intact freely behaving rat pups using whole body plethysmography during room air
(RA), hypercapnic (5% CO(2)), and hypoxic (10% O(2)) conditions, both before and
after administration of the non-N-methyl-D-aspartate (NMDA) receptor antagonist
1,2,3, 4-tetrahydro-6-nitro-2,3-dioxobenzo[f]quinoxaline-7-sulfonamide disodium
(NBQX; 10 mg/kg ip). In all age groups, V(E) during RA was unaffected by NBQX,
despite reductions in breathing frequency (f) induced by increases in both
inspiratory and expiratory duration. During hypoxia and hypercapnia, V(E)
increases were similar in both NBQX and control conditions in all age groups.
However, tidal volume was greater and f lower after NBQX. To determine if AMPA
receptor-positive neurons are recruited during hypoxia, immunostaining for AMPA
receptor (GluR2/3) and c-fos colabeling was performed in caudal brain stem
sections after exposing rat pups at postnatal ages 2, 5, 10, and 20 days, and
adult rats to room air or 10% O(2) for 3 h. GluR2/3 expression increased with
postnatal age in the nucleus of the solitary tract (NTS) and hypoglossal nucleus,
whereas a biphasic pattern emerged for the nucleus ambiguus (NA). c-fos
expression was enhanced by hypoxia at all postnatal ages in the NTS and NA and
also demonstrated a clear maturational pattern. However, colocalization of
GluR2/3 and c-fos was not affected by hypoxia. We conclude that AMPA glutamate
receptor expression in the caudal brain stem is developmentally regulated.
Furthermore, the role of non-NMDA receptors in respiratory control of conscious
neonatal rats appears to be limited to modest, albeit significant, regulation of
breathing pattern.
PMID- 10666157
TI - Is fluid-phase endocytosis conserved in hepatocytes of species acclimated and
adapted to different temperatures?
AB - Our primary objective was to determine if rates of fluid-phase endocytosis (FPE)
were conserved in hepatocytes from organisms acclimated and adapted to different
temperatures. To this aim, the fluorescent dye Lucifer yellow was employed to
measure FPE at different assay temperatures (AT) in hepatocytes from 5 degrees C-
and 20 degrees C-acclimated trout, Oncorhynchus mykiss (at 5 and 20 degrees C
AT), 22 degrees C- and 35 degrees C-acclimated tilapia, Oreochromis nilotica (at
22 and 35 degrees C AT), and the Sprague-Dawley rat (at 10, 20, and 37 degrees C
AT). FPE was also studied in rats fed a long-chain polyunsaturated fatty acid
(PUFA)-enriched diet (at 10 degrees C AT). Despite being temperature dependent,
endocytic rates (values in pl. cell(-1). h(-1)) in both species of fish were
compensated after a period of acclimation. For example, in 20 degrees C
acclimated trout, the rate of endocytosis declined from 1.84 to 1.07 when the AT
was reduced from 20 to 5 degrees C; however, after a period of acclimation at 5
degrees C, the rate (at 5 degrees C AT) was largely restored (1.80) and almost
perfectly compensated (95%). In tilapia, endocytic rates were also temperature
compensated, although only partially (36%). Relatively similar rates obtained at
5 degrees C in 5 degrees C-acclimated trout (1.8), at 20 degrees C in 20 degrees
C-acclimated trout (1.84), and at 22 degrees C in 22 degrees C-acclimated tilapia
(2.2) suggest that endocytic rates are somewhat conserved in these two species of
fish. In contrast, the rate in rat measured at 37 degrees C (16.83) was
severalfold greater than in fish at their respective body temperatures. A role
for lipids in determining rates of endocytosis was supported by data obtained at
10 degrees C in hepatocytes isolated from rats fed a long-chain PUFA-enriched
diet: endocytic rates were higher (5.35 pl. cell(-1). h(-1)) than those of rats
fed a standard chow diet (2.33 pl. cell(-1). h(-1)). The conservation of
endocytic rates in fish may be related to their ability to conserve other
membrane characteristics (i.e., order or phase behavior) by restructuring their
membrane lipid composition or by modulating the activities of proteins that
regulate endocytosis and membrane traffic, whereas the lack of conservation
between fish and rat may be due to differences in metabolic rate.
PMID- 10666158
TI - Tumor necrosis factor (TNF)-alpha induces leptin production through the p55 TNF
receptor.
AB - Tumor necrosis factor (TNF)-alpha acts directly on adipocytes to increase
production of the lipostatic factor, leptin. However, which TNF receptor (TNFR)
mediates this response is not known. To answer this question, leptin was measured
in plasma of wild-type (WT), p55, and p75 TNFR knockout (KO) mice injected
intraperitoneally with murine TNF-alpha and in supernatants from cultured WT,
p55, and p75 TNFR KO adipocytes incubated with TNF-alpha. Leptin also was
measured in supernatants from C3H/HeOuJ mouse adipocytes cultured with blocking
antibodies to each TNFR and TNF-alpha as well as in supernatants from adipocytes
incubated with either human or murine TNF-alpha, which activate either one or
both TNFR, respectively. The results using all four strategies show that the
induction of leptin production by TNF-alpha requires activation of the p55 TNFR
and that although activation of the p75 TNFR alone cannot cause leptin
production, its presence affects the capability of TNF-alpha to induce leptin
production through the p55 TNFR. These results provide new information on the
interplay between cells of the immune system and adipocytes.
PMID- 10666159
TI - The bone and joint decade 2000-2010.
PMID- 10666160
TI - Crystal unclear.
PMID- 10666161
TI - Bridging the gap in rheumatology.
PMID- 10666162
TI - Right ventricular diastolic abnormalities in systemic sclerosis. Relation to left
ventricular involvement and pulmonary hypertension.
AB - OBJECTIVES: To investigate right ventricular diastolic function in systemic
sclerosis (SSc) and its relation to clinical features of the disease. METHODS:
Seventy seven unselected SSc patients and 33 healthy subjects were submitted to
echocardiography and echo Doppler study to assess left and right systolic as well
diastolic function and to estimate maximal arterial systolic pulmonary pressure
(PAP). In addition, the patients were investigated to define the SSc subset and
the extent of skin and internal organ involvement. RESULTS: An abnormal right
ventricular filling, as expressed by an inverted tricuspidal (Tr) E/A ratio (Tr
E/A ratio <1), was detected in 31 of the 77 SSc patients (40%) and in 0 of the 36
controls ( p<0.001 ). All the 31 patients with an inverted Tr E/A ratio were
found to have a PAP > 30 mm Hg. Twenty resulted to have an inverted mitral (Mit)
E/A ratio (Mit E/A ratio <1), indicating an abnormal left ventricular filling. In
multiple regression analysis, Tr E/A ratio resulted to be independently
correlated to both PAP (r= -0.35;p<0. 003) and Mit E/A ratio (r=0.39;p<0.001).
CONCLUSIONS: This study points out an impaired right ventricular filling in a
significant percentage of SSc patients whatever the subset. This alteration is
independently correlated to both PAP and left ventricular filling abnormalities.
PMID- 10666163
TI - The clinical relevance of antibodies to ribosomal-P common epitope in two
targeted systemic lupus erythematosus populations: a large cohort of consecutive
patients and patients with active central nervous system disease.
AB - OBJECTIVES: To develop an enzyme linked immunosorbent assay (ELISA) using as
substrate a synthetic 22-aminoacid peptide, corresponding to the ribosomal P0, P1
and P2 common epitope. To study the specificity and sensitivity of the method and
evaluate the frequency and clinical associations of anti-P antibodies in two
groups of systemic lupus erythematosus (SLE) patients: (a) unselected SLE
patients and (b) SLE patients with central nervous system (CNS) involvement.
PATIENTS AND METHODS: The C-terminal 22 aminoacid peptide of the ribosomal P
proteins (Lys-Lys-Glu-Glu-Lys-Lys-Glu-Glu-Lys-Ser-Glu-Glu-Glu-Asp-Glu-Asp-Met-
Gly-Phe-Gly-Leu-Phe-Asp) was synthesised according to Merrifield's solid phase
procedure. Purification of the peptide was performed by preparative high
performance liquid chromatography and confirmed by amino acid analysis. Using
this peptide, in a concentration 5 microg/ml, an ELISA was developed. The
presence of anti-P antibodies was evaluated by western blot using purified
ribosomal proteins from rat liver. Sera from 178 consecutive patients with SLE
and 28 patients with SLE and CNS manifestations were tested. Sera from 58
patients with rheumatoid arthritis and 57 patients with primary Sjogren's
syndrome were used as controls. The cut off point of the assay was defined using
124 normal sera. RESULTS: The specificity of the assay was evaluated by
homologous inhibition. Pretreatment of positive sera with soluble 22mer peptide
of the ribosomal P proteins resulted in 88% inhibition. The concordance between
the peptide assay and western blot was found to be 83%. Thirty three of 178 (18.
6%) of the unselected SLE patients had antibodies to P-protein common epitope.
Their presence was associated with more active disease (European Consensus Lupus
Activity Measurement, ECLAM scoring system) (p<0.001), higher levels of anti-ds
DNA antibodies (p<0.05) and lower levels of the C4 component of complement
(p<0.01). Eleven of 28 (39.3%) patients with SLE and active CNS involvement had
antibodies to P-protein. The overall prevalence of anti-P antibodies in active
CNS disease patients was statistically significantly higher, as compared with
unselected SLE patients (chi(2)=6.04, p<0.05). These antibodies were found in a
high proportion of patients without anticardiolipin antibodies (52.4%) and they
were associated with diffuse CNS involvement (psychiatric disorders (71%) and
epilepsy (75%)). CONCLUSIONS: A synthetic analogue of the common epitope of
ribosomal P-proteins can be use as an antigen for the detection of anti-P
antibodies. These antibodies are associated with active SLE and CNS involvement
particularly in patients without anticardiolipin antibodies.
PMID- 10666164
TI - Hormone replacement therapy and patterns of osteoarthritis: baseline data from
the Ulm Osteoarthritis Study.
AB - OBJECTIVES: It has been suggested that hormone replacement therapy (HRT) may
protect against osteoarthritis (OA). The aim of this paper was to assess the
association between HRT and radiographically defined patterns of OA. METHODS: 475
consecutive women aged 50 years or older (mean age 66.1) who underwent hip or
knee joint replacement because of advanced OA in four hospitals in south west
Germany were enrolled in a cross sectional study. Participants underwent a
standardised interview including detailed history of medication use and a
physical examination. Furthermore, radiographs of the joint being replaced and of
the contralateral joint as well as of both hands were obtained. Patients were
categorised as having bilateral or unilateral OA according to the presence or
absence of radiographic OA in the contralateral joint. If radiographic OA of
different hand and finger joint groups was present, participants were categorised
as having generalised OA (GOA). Logistic regression was used to estimate odds
ratios and their 95% confidence intervals for the association between HRT and
bilateral or GOA while adjusting for potential confounders. RESULTS: Fifty five
women (11.6%) were using HRT. The median duration of use was 5.4 years. The
prevalence of bilateral and GOA was similar among users of ORT (86.3% and 27.5%,
respectively) and among non-users of HRT (88.7% and 35.7%, respectively). After
adjustment for potential confounding factors, the odds ratios (95% confidence
intervals) of bilateral OA and GOA among HRT users compared with non-users was
1.21 (0.48, 3.03) and 1. 21 (0.53, 2.74), respectively. CONCLUSION: Despite
limited generalisability because of the selective study sample, these data do not
support the hypothesis that HRT acts as a systemic protective factor against OA.
PMID- 10666165
TI - Bone mineral density in systemic lupus erythematosus: comparison with rheumatoid
arthritis and healthy controls.
AB - OBJECTIVES: To examine bone mineral density (BMD) frequency of osteoporosis and
reduced bone mass in systemic lupus erythematosus (SLE), and compare the data of
the SLE patients with matched rheumatoid arthritis (RA) patients and healthy
controls. Secondly, to study possible correlations between BMD, demographic and
disease variables in the SLE patients. METHODS: Measures of BMD assessed by dual
energy x ray absorptiometry were obtained from 75 SLE patients aged = 70 years,
75 RA patients matched for age, sex and disease duration, and from 75 healthy
controls matched for age, sex and geographical area. Disease activity and
accumulated organ damage were assessed in the SLE patients. RESULTS: The SLE
patients had significantly lower BMD values at lumbar spine L2-L4 and hip, and
higher frequency of osteoporosis at all sites of measurement compared with
matched healthy controls. The matched SLE and RA patients had similar BMD,
prevalence of osteoporosis and reduced bone mass. In the SLE patients BMD was
more strongly correlated with accumulated organ damage than with markers of
disease activity or duration. In multivariate analyses BMD was at all sites
predicted by age and body mass, at lumbar spine also by the current
corticosteroid dose. CONCLUSION: The study showed reduced BMD in patients with
SLE compared with matched healthy controls. Premenopausal women taking
corticosteroids were especially affected. Furthermore, the BMD of matched SLE and
RA patients was reduced to a similar extent.
PMID- 10666166
TI - Racial group, socioeconomic status, and the development of persistent proteinuria
in systemic lupus erythematosus.
AB - OBJECTIVES: Systemic lupus erythematosus (SLE) patients of Afro-Caribbean and
Asian origin living in the United Kingdom have a more severe spectrum of disease
compared with the white population but whether this is attributable to genetic
host factors or environmental factors is unclear. This study examines time from
first symptom to onset of persistent proteinuria, as a marker of renal disease,
to assess which factors are important. METHODS: The 189 patients studied were
ascertained using multiple methods and included 161 white, 22 Afro-Caribbean and
six Asian patients. Time of first observation of persistent proteinuria (>/=0.5
g/day) was taken as onset of renal SLE. Initial univariate analysis to determine
which factors are associated with onset of renal disease was followed by using a
Cox's proportional hazards regression model enabling analysis of several
prognostic factors at the same time. Variables included three measures of
socioeconomic status, ethnic group and the presence or absence of different
autoantibodies. RESULTS: There was no effect from any socioeconomic variable.
Using forwards stepwise selection, the following had independent effects (p<0.05)
on the development of renal SLE: Afro-Caribbean race (hazard rate ratio 4.4 (1.9
10.2), compared with white population); and the presence of IgG anti-cardiolipin
antibodies (hazard rate ratio 2.6 (1.2-5.7)). CONCLUSION: Differing socioeconomic
factors do not explain the increased frequency of lupus nephritis in Afro
Caribbean patients with SLE, but rather there are important genetic or other host
differences. The independent effect of IgG anti-cardiolipin antibodies warrants
further investigation.
PMID- 10666167
TI - Transverse myelopathy in systemic lupus erythematosus: an analysis of 14 cases
and review of the literature.
AB - OBJECTIVE: To give a comprehensive review of transverse myelopathy (TM), a rare
but serious condition reported in 1-2% of patients with systemic lupus
erythematosus (SLE). METHODS: 14 patients with SLE and TM were evaluated and 91
additional cases published in the English and German literature reviewed.
RESULTS: TM presented either as the initial manifestation or within five years of
the diagnosis of SLE. Most patients presented with a detectable sensory deficit
at the thoracic level. In our 14 patients, 22% of the patients showed complete
neurological recovery, whereas in the total patient population of 105 (our cases
plus those reviewed in the literature), complete recovery was observed in 50%,
partial recovery in 29% and no improvement or deterioration in 21%. Treatment
with intravenous methylprednisolone followed by cyclophosphamide seemed to be
most effective. Seventy per cent of the total patient population had abnormal
magnetic resonance imaging findings. In our group of 14 patients, those with
higher disease activity (measured by the SLAM) at onset of TM were treated more
aggressively (for example, with plasmapheresis and intravenous pulse
cyclophosphamide). TM in our patients was associated with antiphospholipid
antibodies in 43% of the cases as compared with 64% of the total patient
population. Optic neuritis occurred in 48% of the total patient population with
SLE and TM, suggesting an association. CONCLUSIONS: TM in SLE is a poorly
understood entity. Outcome might be more favourable than previously suggested.
There is an association of TM with antiphospholipid antibodies in SLE patients.
Treatment including intravenous cyclophosphamide may improve the final outcome.
This report emphasises the need for multicentre trials to establish guidelines
for optimal treatment.
PMID- 10666168
TI - Angiotensin converting enzyme in human synovium: increased stromal [(125)I]351A
binding in rheumatoid arthritis.
AB - OBJECTIVE: To determine whether tissue angiotensin converting enzyme (ACE) is
increased in synovia from patients with rheumatoid arthritis, osteoarthritis or
chondromalacia patellae. METHODS: Sections of synovia from patients with
rheumatoid arthritis (n = 7), osteoarthritis (n = 7) or chondromalacia patellae
(n = 6) were tested for immunoreactivity for ACE, and for binding of the ACE
inhibitor [(125)I]351A. The amount of ACE was measured with computer assisted
image analysis as the proportion of synovial section area occupied by ACE
immunoreactive cells, and the density of [(125)I]351A binding. RESULTS:
[(125)I]351A binding sites had characteristics of ACE and colocalised with ACE
like immunoreactivity to microvascular endothelium and fibroblast-like stromal
cells in inflamed and non-inflamed human synovium. Stromal [(125)I]351A binding
densities (B(eq)) and the fraction of synovial section area occupied by ACE
immunoreactivity (fractional area) were higher in synovia from patients with
rheumatoid arthritis (B(eq) 28 amol/mm(2), fractional area 0.21) than from those
with osteoarthritis (B(eq) 9 amol/mm(2), fractional area 0.10) or chondromalacia
patellae (B(eq) 9 amol/mm(2), fractional area 0.09)(p < 0.05). Density of
[(125)I]351A binding to stroma was similar to that to blood vessels in rheumatoid
arthritis, but less dense than vascular binding in chondromalacia patellae and
osteoarthritis. Increases in [(125)I]351A binding densities were attributable to
increases in the numbers of binding sites, and were consistent with an increase
in the density of ACE bearing stromal cells. CONCLUSION: ACE is upregulated in
synovial stroma in rheumatoid arthritis. Increased tissue ACE may result in
increased local generation of the vasoconstrictor and mitogenic peptide
angiotensin II and thereby potentiate synovial hypoxia and proliferation in
rheumatoid arthritis.
PMID- 10666169
TI - Soluble thrombomodulin concentration is raised in scleroderma associated
pulmonary hypertension.
AB - OBJECTIVE: To investigate the expression of thrombomodulin in scleroderma
associated pulmonary hypertension. METHODS: Soluble thrombomodulin (sTM), was
measured in plasma samples from 34 scleroderma patients shown to have pulmonary
hypertension at echocardiogram, and comparison drawn against samples from 38
scleroderma control patients, and 20 healthy controls. Serial measurements of sTM
were performed in the 34 patients with scleroderma associated pulmonary
hypertension to investigate possible changes in sTM concentration with
progression of the condition. RESULTS: Mean sTM was raised in scleroderma
associated pulmonary hypertension when compared with scleroderma controls (mean
sTM 65.4 ng/ml v 43.3 ng/ml, p<0.05), and when compared with healthy controls
(mean sTM 38.1 ng/ml, p<0.05). There was no significant difference between mean
sTM in scleroderma controls and healthy controls. Mean sTM concentration did not
change with progression of pulmonary hypertension. CONCLUSION: Plasma sTM is
raised in scleroderma associated pulmonary hypertension. The pathogenesis of
scleroderma associated pulmonary hypertension may be distinct from the
pathogenesis of other forms of pulmonary vascular disease.
PMID- 10666170
TI - Quantitative analyses of sacroiliac biopsies in spondyloarthropathies: T cells
and macrophages predominate in early and active sacroiliitis- cellularity
correlates with the degree of enhancement detected by magnetic resonance imaging.
AB - OBJECTIVE: Sacroiliitis is a hallmark of the spondyloarthropathies (SpA). The
degree of inflammation can be quantified by magnetic resonance imaging (MRI). The
aim of this study was to further elucidate the pathogenesis of SpA by
quantitative cellular analysis of immunostained sacroiliac biopsy specimens and
to compare these findings with the degree of enhancement in the sacroiliac joints
(SJ) as detected by dynamic MRI. METHODS: The degree of acute sacroiliitis
detected by MRI after intravenous administration of gadolinium-DTPA was
quantitatively assessed by calculating the enhancement observed in the SJ and
chronic changes were graded as described in 32 patients with ankylosing
spondylitis (n=18), undifferentiated SpA (n=12) and psoriatic arthritis (n=2).
Back pain was graded on a visual analogue scale (VAS, 0-10) and disease duration
(DD) was assessed. Shortly after MRI, SJ of patients with VAS > 5 were biopsied
guided by computed tomography. Immunohistological examination was performed using
the APAAP technique; only whole sections > 3 mm were counted. RESULTS: By MRI,
chronic changes = grade II were detected in nine patients (group I, DD 2.5 (SD
2.9) years) and > II in 13 patients (group II, DD 7.3 (SD 4.8) years), while
enhancement < 70% was found in eight (group A, DD 5.6 (SD 3.3) years) and > 70%
in 12 patients (group B, DD 4.7 (SD 5.8) years). The relative percentage of
cartilage (78-93%), bone (7-18%) and proliferating connective tissue (1-4%) was
comparable between the groups (range). There were more inflammatory cells in
group I compared with group II (mean (SD) 26.7(20.1) versus 5.3 (5. 2), p=0.04)
and group A compared with B (21.8 (17.3) versus 6.0 (5. 6), p=0.05) cells/10
mm(2)), T cells (10.9 (8.5)) being slightly more frequent than macrophages (9.6
(16.8/10 mm(2))). Clusters of proliferating fibroblasts were seen in three and
new vessel formation in seven cases. CONCLUSION: This study shows that T cells
and macrophages are the most frequent cells in early and active sacroiliitis in
SpA. The correlation of cellularity and MRI enhancement provides further evidence
for the role of dynamic MRI to detect early sacroiliitis.
PMID- 10666171
TI - The relative prevalence of dermatomyositis and polymyositis in Europe exhibits a
latitudinal gradient.
PMID- 10666172
TI - Synovial membrane p53 protein immunoreactivity in rheumatoid arthritis patients.
AB - OBJECTIVES: To examine the expression of the p53 protein in synovial membrane of
rheumatoid arthritis (RA) patients and to compare this with the expression in
normal synovial tissues in subjects without RA. METHODS: Immunohistological
expression of the p53 protein was studied using a streptavidin-biotin-peroxidase
method and the monoclonal antibody DO-7, an antibody directed against both wild
and mutant forms of p53 protein, in synovial tissues of RA patients (n=10) and
from subjects with no known joint disease (n=4). RESULTS: p53 protein expression
was present in a small percentage of synovial cells in the majority of the RA
patients (n=8; 80%) and in half of the normal control cases with no inflammatory
joint disease (n=2; 50%). No sample had more than 5% cells staining with
intranuclear pattern. The difference in synovial p53 immunoreactivity between the
RA patients and normal controls is not statistically significant (p= 0.64; chi(2)
contingency test). CONCLUSIONS: This study has shown that p53 protein is only
weakly expressed in the rheumatoid synovial membrane, with a low percentage of
p53 protein immunostaining cells present, with intranuclear staining. These
results suggest this is wild type p53 protein rather than mutant protein. These
findings suggest that synovial p53 protein expression may not be important in the
pathogenesis of RA and may only represent a reactive repair process to DNA damage
secondary to the immune and inflammatory reactions associated with the disease.
PMID- 10666173
TI - Effects of cyclosporin at various concentrations on dexamethasone intracellular
uptake in multidrug resistant cells.
AB - BACKGROUND: The multidrug resistance phenomenon results from the expression of P
glycoprotein (P-gp), a drug-efflux pump. Corticosteroids are substrates for P-gp,
whose function can be inhibited by cyclosporin. This study evaluates the ability
of cyclosporin to modulate dexamethasone uptake in multidrug resistant cells.
METHODS: The K 562 cell line, which does not express P-gp and a P-gp expressing
clone, K562/ADM, were used. Cells were incubated with H3-dexamethasone in the
absence or presence of cyclosporin at various concentrations. Then, cells were
washed, lysed, and radioactivity was measured. RESULTS: The uptake of
dexamethasone alone was higher in sensitive than in resistant cells. Addition of
cyclosporin induced a dose dependent increase of dexamethasone uptake in
resistant cells, whereas the drug did not influence dexamethasone uptake in
parental cells. CONCLUSION: Cyclosporin, at therapeutic concentrations induces a
moderate, but significant increase in dexamethasone accumulation in multidrug
resistant cells. Thus, cyclosporin might increase the intestinal absorption of
corticosteroids or their accumulation in mononuclear cells, or both, thereby
increasing their therapeutic efficacy.
PMID- 10666174
TI - A prospective study on the incidence of rheumatoid arthritis among people with
persistent increase of rheumatoid factor.
AB - OBJECTIVES: To study the stability of rheumatoid factor (RF) increases and to
compare the incidence of rheumatoid arthritis (RA) in people with transient or
persistent increase of one or more RF isotypes. METHODS: From an original cohort
of nearly 14 000 participants in a population study, 135 previously RF positive
persons were recruited in 1996 and evaluated according to the 1987 ACR criteria.
The observation time ranged from 9-22 years (mean 16. 5). Blood samples were
obtained from all participants at entry and again in 1996. RESULTS: About 40% of
the participants who had only one raised RF isotype in the original sample had
become RF negative in 1996 compared with only 15% of those with increase of two
or three RF isotypes (p=0.002). The seven participants who developed RA during
the study period all had persistently raised RF. Six of the 54 participants with
more than one RF isotype raised in 1996 developed RA, corresponding to an annual
incidence of 0.67%, which was 7.5 times higher than observed in the other
participants (p=0. 045). CONCLUSION: Symptom free persons with persistently
raised RF have greatly increased risk of developing RA. This suggests that
dysregulation of RF production is a predisposing factor in RA.
PMID- 10666175
TI - The existence of geographical clusters of cases of inflammatory polyarthritis in
a primary care based register.
AB - OBJECTIVES: To determine whether there is any evidence that there are spatial
clusters of rheumatoid arthritis in particular, and inflammatory arthritis in
general. METHODS: Setting was a population based incidence register of
inflammatory arthritis: the Norfolk Arthritis Register (NOAR). All cases
identified between 1990-1995 were mapped to place of residence. Statistical
evidence of clustering was determined by calculating Poisson probabilities in
putative areas. RESULTS: Three clusters were identified including one small area
(population 85) where five unrelated cases developed during this time period.
There was no obvious greater disease homogeneity within clusters and no common
environmental factors were identified. CONCLUSION: Rare clusters of inflammatory
polyarthritis do occur. Their significance and cause remain to be elucidated.
PMID- 10666176
TI - Influence of development and joint pathology on stromelysin enzyme activity in
equine synovial fluid.
AB - OBJECTIVE: To investigate the role of stromelysin (MMP-3) activity in synovial
fluid (SF) at different stages of development and in common joint disorders in
the horse. METHODS: Stromelysin activity was determined with a fluorogenic enzyme
activity assay in SF of normal joints of fetal, juvenile and adult horses, and in
SF of horses suffering from the developmental orthopaedic disease osteochondrosis
(OC) or osteoarthritis (OA). Additionally, MMP-3 activity was expressed as a
ratio of previously reported general MMP activity in the same SF samples.
RESULTS: The levels of active stromelysin were 30-fold to 80-fold higher in SF
from fetal horses than in SF from juvenile and mature animals (p<0.001). Juvenile
horses (5 and 11 months of age) showed a twofold to threefold higher stromelysin
activity than adult horses ( p<0.05). In OC joints, stromelysin activity was not
significantly different from the activity in normal, age matched, control joints.
In OA joints the activity was about four times higher than in normal joints
(p<0.001). The ratio MMP-3 activity/general MMP activity did not change with age
in normal, healthy joints. This ratio was more then twofold increased in OA
joints compared with normal joints, indicating selective upregulation of gene
expression or activation of proMMP-3, or both, in OA pathology. CONCLUSIONS: The
significantly higher stromelysin activity in young individuals parallels the
higher metabolic activity occurring at rapid growth and differentiation at early
age. In OC, MMP-3 mediated matrix degradation appears to be not different from
normal joints. The increased stromelysin activity in OA joints is in agreement
with pathological matrix degradation. In these joints MMP-3 activity is
selectively increased compared with normal joints.
PMID- 10666177
TI - Relation of glenohumeral and acromioclavicular joint destruction in rheumatoid
shoulder. A 15 year follow up study.
AB - OBJECTIVES: To evaluate the relation of glenohumeral (GH) and acromioclavicular
(AC) joint involvement in a cohort of 74 patients with seropositive and erosive
rheumatoid arthritis (RA) followed up prospectively. METHODS: At the 15 year
follow up radiographs of 148 shoulders were evaluated, and the grade of
destruction of GH and AC joints were assessed by the Larsen method. One GH joint
arthroplasty had been performed after 13 years of the disease onset and the
preoperative radiograph was evaluated. RESULTS: Erosive involvement (Larsen grade
>/= 2) was observed in 96 of 148 (65%) of the shoulders. Both GH and AC joints
were affected in 62 of 148 (42%) shoulders. GH joint alone was involved in nine
(6%) shoulders and only AC joint was affected in 25 (17%) shoulders. AC joint
destruction correlated with the GH joint destruction, r=0.74 (95% confidence
intervals (CI) 0.65 to 0.80 ). CONCLUSION: In RA AC joint is affected more often
than the GH joint, but in half of the patients both joints are involved. This
should be remembered when treating painful rheumatoid shoulder.
PMID- 10666178
TI - Introduction: are natural anticoagulants candidates for modulating the
inflammatory response to endotoxin?
PMID- 10666179
TI - Recombinant human antithrombin III improves survival and attenuates inflammatory
responses in baboons lethally challenged with Escherichia coli.
AB - Plasma-derived antithrombin III (ATIII) prevents the lethal effects of
Escherichia coli infusion in baboons, but the mechanisms behind this effect are
not clear. In the present study, we evaluated the effects of recombinant human
ATIII (rhATIII) on the clinical course and the inflammatory cytokine and
coagulation responses in baboons challenged with lethal dose of E coli. Animals
in the treatment group (n = 5) received high doses of rhATIII starting 1 hour
before an E coli challenge. Those in the control group were administered saline.
Survival was significantly improved in the treatment group (P =.002). Both groups
had similar hemodynamic responses to E coli challenge but different coagulation
and inflammatory responses. The rhATIII group had an accelerated increase of
thrombin-ATIII complexes and significantly less fibrinogen consumption compared
to controls. In addition, the rhATIII group had much less severe thrombotic
pathology on autopsy and virtually no fibrinolytic response to E coli challenge.
Furthermore, the rhATIII group had a significantly attenuated inflammatory
response as evidenced by marked reduction of the release of various cytokines. We
conclude that the early administration of high doses of rhATIII improves the
outcome in baboons lethally challenged with E coli, probably due to the combined
anticoagulation and anti-inflammatory effects of this therapy. (Blood.
2000;95:1117-1123)
PMID- 10666180
TI - Tissue factor pathway inhibitor dose-dependently inhibits coagulation activation
without influencing the fibrinolytic and cytokine response during human
endotoxemia.
AB - Inhibition of the tissue factor pathway has been shown to attenuate the
activation of coagulation and to prevent death in a gram-negative bacteremia
primate model of sepsis. It has been suggested that tissue factor influences
inflammatory cascades other than the coagulation system. The authors sought to
determine the effects of 2 different doses of recombinant tissue factor pathway
inhibitor (TFPI) on endotoxin-induced coagulant, fibrinolytic, and cytokine
responses in healthy humans. Two groups, each consisting of 8 healthy men, were
studied in a double-blind, randomized, placebo-controlled crossover study.
Subjects were studied on 2 different occasions. They received a bolus intravenous
injection of 4 ng/kg endotoxin, which was followed by a 6-hour continuous
infusion of TFPI or placebo. Eight subjects received 0.05 mg/kg per hour TFPI
after a bolus of 0.0125 mg/kg (low-dose group), and 8 subjects received 0.2 mg/kg
per hour after a bolus of 0.05 mg/kg (high-dose group). Endotoxin injection
induced the activation of coagulation, the activation and subsequent inhibition
of fibrinolysis, and the release of proinflammatory and antiinflammatory
cytokines. TFPI infusion induced a dose-dependent attenuation of thrombin
generation, as measured by plasma F1 + 2 and thrombin-antithrombin complexes,
with a complete blockade of coagulation activation after high-dose TFPI.
Endotoxin-induced changes in the fibrinolytic system and cytokine levels were not
altered by either low-dose or high-dose TFPI. The authors concluded that TFPI
effectively and dose-dependently attenuates the endotoxin-induced coagulation
activation in humans without influencing the fibrinolytic and cytokine response.
(Blood. 2000;95:1124-1129)
PMID- 10666181
TI - Sickle cell anemia day hospital: an approach for the management of uncomplicated
painful crises.
AB - Painful crisis episodes are poorly treated in sickle cell anemia, both in
timeliness and appropriateness of care. Delayed treatment in Emergency
Departments, unrelieved pain, frequent admissions, and prolonged hospitalizations
are common. We established a Day Hospital (DH) to determine if an alternative
care delivery system could improve pain relief and reduce unnecessary hospital
admissions for patients with uncomplicated painful crises. Trained DH staff
delivered prompt titration for pain relief based on each patient's analgesic
history and qualitative and quantitative assessments. Response to therapy and
comorbidities commanded disposition. During the first 5 years of DH operation
there were 2554 visits; 60% of the patients had severe pain. During an average
visit of 4.5 hours, 84% of the patients were titrated to relief; 90% had pain
relief within 2 to 4 hours. Overall, 81% of the patients were discharged home
(70% initially and 90% to 94% in the last 3 years). During the first 5 years of
the DH, there were 2612 emergency department (ED) visits that averaged 13 hours
each. The combined ED and DH admissions during this time represented a 40%
decrease in the baseline ED admission rate of 92%, (1 year pre-DH). Patients with
uncomplicated painful crisis were admitted 5 times less often from the DH (8.3%)
than from the ED (42.7%). The length of stay (LOS) for inpatients followed by the
DH staff decreased by 1.5 days, while the LOS for patients followed by non-DH
staff remained unchanged. Reduction of admissions and LOS represented a savings
of approximately $1.7 million. We conclude that a dedicated facility provides the
kingpin for effective and rapid painful crisis management, reduces
hospitalizations, and facilitates integration of the approach into other areas of
care. (Blood. 2000;95:1130-1136)
PMID- 10666182
TI - Simple PCR detection of haptoglobin gene deletion in anhaptoglobinemic patients
with antihaptoglobin antibody that causes anaphylactic transfusion reactions.
AB - Two anhaptoglobinemic patients showing anaphylactic transfusion reactions by
antihaptoglobin antibody were found. Southern blot analysis indicated that 2
patients were homozygous for the deleted allele of the haptoglobin gene (Hp(del))
as reported previously. We have identified the junction region of the deletion
from genomic DNA of 1 patient using cassette-mediated polymerase chain reaction
(PCR). Then, the deleted region from the 5' breakpoint to the promoter region of
the Hp was amplified from genomic DNA of a control individual using PCR. DNA
sequence analysis of these regions indicated that the 5' breakpoint of the
Hp(del) allele was located 5. 2 kilobase (kb) upstream of exon 1 of the Hp and
the 3' breakpoint was positioned between 52 and 53 base pair (bp) upstream of
exon 5 of the haptoglobin-related gene. There was no significant homology between
the DNA sequences flanking the 5' and 3' breakpoints, except for a 2-bp (TG)
identity. To examine the gene frequency, we have developed a simple PCR method to
detect the gene deletion. We found 8, 16, and 17 Hp(del) alleles in 157 Koreans,
523 Japanese, and in 284 Chinese, respectively, but did not find the Hp(del) in
101 Africans or in 100 European-Africans. The incidence of individuals homozygous
for the Hp(del) allele was therefore expected to be 1/4000 in Japanese, 1/1500 in
Koreans, and 1/1000 in Chinese. This incidence is higher than that of IgA
deficiency in Japanese. More attention should be paid on haptoglobin deficiency
and antihaptoglobin antibody as the cause of transfusion-related anaphylactic
reactions in Asian populations. (Blood. 2000;95:1138-1143)
PMID- 10666183
TI - Acquired loss of p53 induces blastic transformation in p210(bcr/abl)-expressing
hematopoietic cells: a transgenic study for blast crisis of human CML.
AB - Chronic myelogenous leukemia (CML) begins with an indolent chronic phase but
inevitably progresses to a fatal blast crisis. Although the Philadelphia
chromosome, which generates p210(bcr/abl), is a unique chromosomal abnormality in
the chronic phase, additional chromosomal abnormalities are frequently detected
in the blast crisis, suggesting that superimposed genetic events are responsible
for disease progression. To investigate whether loss of p53 plays a role in the
evolution of CML, we crossmated p210(bcr/abl)-transgenic (BCR/ABL(tg/-)) mice
with p53-heterozygous (p53(+/-)) mice and generated p210(bcr/abl)-transgenic, p53
heterozygous (BCR/ABL(tg/-)p53(+/-)) mice, in which a somatic alteration in the
residual normal p53 allele directly abrogates p53 function. The BCR/ABL(tg/
)p53(+/-) mice died in a short period compared with their wild-type (BCR/ABL(-/
)p53(+/+)), p53 heterozygous (BCR/ABL(-/-)p53(+/-)), and p210(bcr/abl) transgenic
(BCR/ABL(tg/-)p53(+/+)) litter mates. They had rapid proliferation of blast
cells, which was preceded by subclinical or clinical signs of a
myeloproliferative disorder resembling human CML. The blast cells were clonal in
origin and expressed p210(bcr/abl) with an increased kinase activity.
Interestingly, the residual normal p53 allele was frequently and preferentially
lost in the tumor tissues, implying that a certain mechanism facilitating the
loss of p53 allele exists in p210(bcr/abl)-expressing hematopoietic cells. Our
study presents in vivo evidence that acquired loss of p53 contributes to the
blastic transformation of p210(bcr/abl)-expressing hematopoietic cells and
provides insights into the molecular mechanism for blast crisis of human CML.
(Blood. 2000;95:1144-1150)
PMID- 10666184
TI - KSHV-encoded CC chemokine vMIP-III is a CCR4 agonist, stimulates angiogenesis,
and selectively chemoattracts TH2 cells.
AB - Kaposi's sarcoma-associated herpesvirus (KSHV) encodes 3 genes that are
homologous to cellular chemokines. vMIP-III, the product of open reading frame
K4.1, is the most distantly related to human chemokines and has yet to be
characterized. We have examined the interaction of vMIP-III with chemokine
receptors, its expression in KS lesions, and its in ovo angiogenic properties. We
show expression of vMIP-III in KS lesions and demonstrate the stimulation of
angiogenesis by this chemokine, like vMIP-I and vMIP-II, in the chick
chorioallantoic membrane assay. vMIP-III does not block human immunodeficiency
virus entry through the coreceptors CCR3, CCR5, or CXCR4. However, vMIP-III is an
agonist for the cellular chemokine receptor CCR4. CCR4 is expressed by TH2-type T
cells. Consistent with this, vMIP-III preferentially chemoattracts this cell
type. Because of these biologic properties and because it is expressed in KS
lesions, vMIP-III may play an important role in the pathobiology of KS. (Blood.
2000;95:1151-1157)
PMID- 10666185
TI - The CXC-chemokine platelet factor 4 promotes monocyte survival and induces
monocyte differentiation into macrophages.
AB - Unstimulated monocytes rapidly undergo physiological changes resulting in
programmed cell death (apoptosis) while stimuli promoting differentiation of
these cells into macrophages were shown to inhibit apoptotic processes. In the
present study, we report that the platelet-derived alpha-chemokine platelet
factor 4 (PF4) induces the differentiation of monocytes into macrophages, as is
evident from morphological changes as well as from the up-regulation of
differentiation markers (carboxypeptidase M/MAX1 and CD71). Significant
alterations of the phenotype were observed after 72 hours of culture in the
presence of the chemokine and required a minimal concentration of 625 nmol/L PF4.
PF4-induced macrophages were characterized by a lack of HLA-DR antigen on their
surface but showed a strong increase in the expression of the CD28 ligand B7-2.
Furthermore, PF4 stimulation prevented monocytes from undergoing spontaneous
apoptosis during 72 hours of culture as determined in an annexin-V-binding assay.
Although PF4 induced the secretion of relevant amounts of TNF-alpha, neutralizing
antibodies directed against TNF-alpha or granulocyte-macrophage colony
stimulating factor (GM-CSF) did not revert PF4-induced rescue from programmed
cell death, suggesting that PF4 exerts its antiapoptotic effects in a TNF-alpha-
or GM-CSF-independent fashion. On the basis of these results, we propose a novel
role for PF4 in the control of monocyte differentiation during an inflammatory
process in vivo. (Blood. 2000;95:1158-1166)
PMID- 10666186
TI - Limited expression of R5-tropic HIV-1 in CCR5-positive type 1-polarized T cells
explained by their ability to produce RANTES, MIP-1alpha, and MIP-1beta.
AB - Human T helper (Th) cells (Th1- or Th2-oriented memory T cells as well as Th1- or
Th2-polarized naive T cells) were infected in vitro with an R5-tropic HIV-1
strain (BaL) and assessed for their profile of cytokine production, CCR5 receptor
expression, and HIV-1 p24 antigen (p24 Ag) production. Higher p24 Ag production
was found in CCR5-negative Th2-like memory T cells than in CCR5-positive Th1-like
memory T cells. By contrast, p24 Ag production was higher in Th1-polarized
activated naive T cells in the first 4 days after infection. However, p24 Ag
production in Th1-polarized T cells became comparable or even lower than the
production in Th2-polarized populations later in infection or when the cells were
infected with HIV-1BaL after secondary stimulation. The higher levels of p24 Ag
production by Th1-polarized naive T cells soon after infection reflected a higher
virus entry, as assessed by the single round infection assay using the HIV
chloramphenicol acetyl transferase (HIV-CAT) R5-tropic virus that contains the
envelope protein of HIV-1 YU2 strain. The limitation of viral spread in the Th1
polarized populations, despite the initial higher level of T-cell entry of R5
tropic strains, was due to the ability of Th1 cells to produce greater amounts of
beta-chemokines than Th2 cells. In fact, an inverse correlation was observed
between Th1-polarized naive T cells and Th1-like memory-activated T cells in
regards to p24 Ag production and the release of the following CCR5-binding
chemokines: regulated on activation normal T expressed and secreted (RANTES),
macrophage inflammatory protein-1alpha (MIP-1alpha), and MIP-1beta. Moreover,
infection with the HIV-1BaL strain of Th1-polarized T cells in the presence of a
mixture of anti-RANTES, anti-MIP-1alpha, and anti-MIP-1beta neutralizing
antibodies resulted in a significant increase of HIV-1 expression. These findings
suggest that Th1-type responses may favor CD4(+) T-cell infection by R5-tropic
HIV-1 strains, but HIV-1 spread in Th1 cells is limited by their ability to
produce CCR5-binding chemokines. (Blood. 2000;95:1167-1174)
PMID- 10666187
TI - Effect of recombinant human erythropoietin combined with granulocyte/ macrophage
colony-stimulating factor in the treatment of patients with myelodysplastic
syndrome. GM/EPO MDS Study Group.
AB - This randomized, placebo-controlled trial was designed to assess the efficacy and
safety of therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF)
and erythropoietin (epoetin alfa) in anemic, neutropenic patients with
myelodysplastic syndrome. Sixty-six patients were enrolled according to the
following French-American-British classification: refractory anemia (20),
refractory anemia with excess blasts (35), refractory anemia with ringed
sideroblasts (9), and refractory anemia with excess blasts in transformation (2).
Patients were stratified by their serum erythropoietin levels (less than or equal
to 500 mU/mL, n = 37; greater than 500 mU/mL, n = 29) and randomized, in a 2:1
ratio, to either GM-CSF (0.3-5.0 microg/kg.d) + epoetin alfa (150 IU/kg 3
times/wk) or GM-CSF (0.3-5.0 microg/kg.d) + placebo (3 times/wk). The mean
neutrophil count rose from 948 to 3831 during treatment with GM-CSF +/- epoetin
alfa. Hemoglobin response (increase greater than or equal to 2 g/dL, unrelated to
transfusion) occurred in 4 of 45 (9%) patients in the GM-CSF + epoetin alfa group
compared with 1 of 21 (5%) patients with GM-CSF + placebo group (P = NS).
Percentages of patients in the epoetin alfa and the placebo groups requiring
transfusions of red blood cells were 60% and 92%, respectively, for the low
endogenous erythropoietin patients and 95% and 89% for the high-endogenous
erythropoietin patients (P = NS). Similarly, the average numbers of units of red
blood cells transfused during the 12-week study in the epoetin alfa and the
placebo groups were 5.9 and 9.5, respectively, in the low-endogenous
erythropoietin patients and 9.7 and 8.6 in the high-endogenous erythropoietin
patients (P = NS). GM-CSF +/- epoetin alfa had no effect on mean platelet count.
Treatment was well tolerated in most patients, though 10 withdrew from the study
for reasons related predominantly to GM-CSF toxicity. (Blood. 2000;95:1175-1179)
PMID- 10666188
TI - Genetic aberrations common in gastric high-grade large B-cell lymphoma.
AB - Genetic aberrations associated with the development of extranodal high-grade
large B-cell lymphoma originating in the stomach have not been fully identified
yet. We analyzed 31 such lymphomas using 73 microsatellite markers for allelic
imbalance and microsatellite instability. The highest frequency (42%) of loss of
heterozygosity (LOH) was found on the long arm of chromosome 6. We identified 2
LOH hot spots on 6q21-22.1 and 6q23.3-25, flanked by markers D6S246-D6S261 and
D6S310-D6S441, respectively, containing putative tumor suppressor genes (TSGs).
These 6q aberrations were found to be the sole allelic imbalance in 1 patient
only; they were mostly accompanied by additional abnormalities. Several known
TSGs, namely, the APC, p15/p16, p53, and DCC genes, were found to suffer frequent
LOH during lymphomagenesis. LOH was also detected in regions containing putative
TSGs on 7q and 13q14. Frequent amplification of genomic material was found in the
2p, 3q27 at the BCL-6 gene locus, 6p, 7q, 11q23-24 at the MLL gene locus, and 18q
regions. Analysis of the pattern of occurrence of these aberrations revealed an
association of the amplification of the MLL gene region with LOH at the p53 locus
(P =.02). Only low frequency of microsatellite instability (MSI) was detected in
these lymphomas and MSI incidence increased with age (P =.01). Karyotypic
instability thus plays the main role in the development of gastric high-grade
large B-cell lymphoma. Common genetic aberrations responsible for lymphomagenesis
are deletions of 6q, loss of p53, and amplification of the 3q27 and the MLL gene
regions. (Blood. 2000;95:1180-1187)
PMID- 10666189
TI - Allogeneic and syngeneic marrow transplantation for myelodysplastic syndrome in
patients 55 to 66 years of age.
AB - We carried out bone marrow transplantation (BMT) in 50 patients with
myelodysplastic syndrome (MDS) who were 55.3 to 66.2 years of age (median, 58.8
years). According to the criteria of the French-American-British (FAB)
classification, 13 patients had refractory anemia (RA), 19 had RA with excess
blasts (RAEB), 16 had RAEB in transformation or acute myelogenous leukemia (RAEB
T/AML), and 2 had chronic myelomonocytic leukemia (CMML). According to the
recently established International Prognostic Scoring System (IPSS), available
for 45 patients, 2 patients were considered low risk; 14, intermediate 1 risk;
19, intermediate 2 risk; and 10, high risk. Conditioning regimens were
cyclophosphamide (CY) (120 mg/kg of body weight) plus 12-Gy fractionated total
body irradiation (FTBI) (n = 15), CY plus FTBI with lung and liver shielding (n =
4), busulfan (7 mg/kg) plus FTBI (n = 4), or busulfan (16 mg/kg) plus CY (n =
27). The busulfan-plus-CY group included 16 patients in whom busulfan was
targeted to plasma levels of 600 to 900 ng/mL. In these 16 patients, steady-state
levels of busulfan actually achieved were 714 to 961 ng/mL (mean +/- SD, 845 +/-
64 ng/mL; median, 838 ng/mL). The donors were HLA-identical siblings for 34
patients, HLA-nonidentical family members for 4, identical twins for 4, and
unrelated volunteers for 6. All 46 patients surviving > 21 days had engraftment,
and 22 patients (44%) are surviving 9 to 80 months after BMT. Specifically, among
13 patients with RA, 1 had relapse (cumulative incidence [CI] at 3 years, 8%) and
8 are surviving, for a Kaplan-Meier (KM) estimate of survival at 3 years of 59%
(disease-free survival [DSF], 53%). Among 19 patients with RAEB, 3 had relapse
(CI at 3 years, 16%), and 8 are surviving disease free (KM estimate at 3 years,
46%). Among 18 patients with RAEB-T/AML or CMML, 6 had relapse (CI at 3 years,
28%), and the KM estimate of DSF at 3 years is 33%. Relapse-free survival had an
inverse correlation with cytogenetic risk classification and with the risk score
according to the IPSS. Survival in all FAB categories was highest among patients
enrolled in a protocol in which busulfan plasma levels were targeted to 600 to
900 ng/mL. These data indicate that BMT can be carried out successfully in
patients with MDS who are older than 55 years of age. (Blood. 2000;95:1188-1194)
PMID- 10666190
TI - Stem cell transplantation in patients with severe congenital neutropenia without
evidence of leukemic transformation.
AB - Severe congenital neutropenia (CN) (Kostmann syndrome) is a hematologic disorder
characterized by a maturation arrest of myelopoiesis at the
promyelocyte/myelocyte stage of development. This arrest results in severe
neutropenia leading to absolute neutrophil counts (ANC) below 0.2 x 10(9)/L
associated with severe bacterial infections from early infancy. Data on over 300
patients with CN collected by the Severe Chronic Neutropenia International
Registry (SCNIR) beginning in 1994 indicate that more than 90% of these patients
respond to recombinant human granulocyte-colony stimulating factor (r-HuG-CSF)
treatment with an ANC greater than 1. 0 x 10(9)/L. For patients who are
refractory to r-HuG-CSF treatment and continue to have severe and often life
threatening bacterial infections, hematopoietic stem cell transplantation is the
only currently available treatment. We report on a total of 11 patients with CN
reported to the SCNIR who underwent transplantation for reasons other than
malignant transformation between 1976 and 1998. Of these patients, 8 were
nonresponders or showed only partial response to r-HuG-CSF treatment with ongoing
infections. Results from these patients suggest that transplantation of stem
cells from an HLA-identical sibling is beneficial for patients refractory to r
HuG-CSF. (Blood. 2000;95:1195-1198)
PMID- 10666191
TI - Apoptosis or plasma cell differentiation of CD38-positive B-chronic lymphocytic
leukemia cells induced by cross-linking of surface IgM or IgD.
AB - Previously, we demonstrated that B-chronic lymphocytic leukemia (B-CLL) cells
could be divided into 2 groups depending on the expression of CD38 by the
malignant cells. The 2 groups differed in their signal-transducing capacities
initiated by cross-linking of surface IgM; only in CD38-positive cells was an
efficient signal delivered, invariably resulting in cell apoptosis. In this
study, we investigated the effect of surface IgD cross-linking in 10 patients
with CD38-positive B-CLL. Exposure of the malignant cells to goat antihuman delta
chain antibodies (Gadelta-ab) caused [Ca(++)]i mobilization and tyrosine kinase
phosphorylation in a manner not different from that observed after goat antihuman
mu-chain antibody (Gamu-ab) treatment in vitro. However, Gadelta-ab-treated cells
failed to undergo apoptosis and instead displayed prolonged survival in culture
and differentiated into plasma cells when rIL2 was concomitantly present. Cross
linking of surface IgD failed to induce proliferation of the malignant cells in
vitro. Moreover, treatment with Gadelta-ab did not prevent apoptosis of B-CLL
cells induced by Gamu-ab. Collectively, these experiments demonstrated that IgM
and IgD expressed by the same cell may deliver opposite signals under particular
circumstances and provide some clues for the understanding of the pathophysiology
of B-CLL. (Blood. 2000;95:1199-1206)
PMID- 10666192
TI - Tissue eosinophilia correlates strongly with poor prognosis in nodular sclerosing
Hodgkin's disease, allowing for known prognostic factors.
AB - Although eosinophilic granulocytes are frequently observed in lymphatic tissue of
Hodgkin's patients, no substantial data reveal the prognostic role, if any, of
tissue eosinophilia. Thus, eosinophilia was analyzed histologically in 1511
diagnostic biopsy specimens of patients treated under protocol therapy of the
German Hodgkin's Lymphoma Study Group between 1988 and 1994. Prominent
eosinophilia was seen in 38% of cases, which differed among the histologic types
of Hodgkin's disease (HD): none in lymphocyte predominant, 14% in lymphocyte rich
classical, 40% in nodular sclerosis grade 1 (NS-1), 55% in nodular sclerosis
grade 2, 43% in mixed cellularity (MC), and 54% in lymphocyte depleted. In a
multivariate analysis, tissue eosinophilia proved to be the strongest prognostic
factor for freedom from treatment failure (P <. 001) and overall survival (P
<.001) in a stage-stratified model. Among NS-1 patients, the effect was highly
significant. In MC, no significant effect of eosinophilia on survival could be
demonstrated. Eosinophils secrete CD30 ligand that is capable of binding to CD30
positive HD cells. The activation of TRAF2, followed by NF-kappaB, which occurs
on CD30L/CD30 binding, may explain the neoplastic proliferation and apoptosis
protection of HD cells. TRAF2 is also activated by EBV-LMP expression, which is
detectable in the majority of MC but not NS cases. In addition to the possibility
that eosinophils are only passive indicators for other unknown prognostic
determinants, it may be concluded that the positive clinical outcome of
eosinophilia-negative NS cases could be due to lower NF-kappaB activity. (Blood.
2000;95:1207-1213)
PMID- 10666193
TI - Treatment of relapsed leukemia after unrelated donor marrow transplantation with
unrelated donor leukocyte infusions.
AB - The efficacy and toxicity of donor leukocyte infusions (DLI) after unrelated
donor bone marrow transplantation (BMT) is largely unknown. We identified 58
recipients of unrelated DLI (UDLI) for the treatment of relapsed disease from the
National Marrow Donor Program database. A retrospective analysis was performed to
determine response, toxicity, and survival after UDLI and to identify factors
associated with successful therapy. UDLI was administered for relapsed chronic
myelogenous leukemia (CML) (n = 25), acute myelogenous leukemia (AML) (n = 23),
acute lymphoblastic leukemia (ALL) (n = 7), and other diseases (n = 3). Eight
patients were in complete remission (CR) before UDLI, and 50 were evaluable for
response. Forty-two percent (95% confidence interval [CI], 28%-56%) achieved CR,
including 11 of 24 (46%; 95% CI, 26%-66%) with CML, 8 of 19 (42%; 95% CI, 20%
64%) with AML, and 2 of 4 (50%; 95% CI, 1%-99%) with ALL. The estimated
probability of disease-free survival (DFS) at 1 year after CR was 65% (95% CI,
50%-79%) for CML, 23% (95% CI, 9%-38%) for AML, and 30% (95% CI, 6%-54%) for ALL.
Acute graft-versus-host disease (GVHD) complicated UDLI in 37% of patients (grade
II-IV, 25%). A total of 13 of 32 evaluable patients (41%) developed chronic GVHD.
There was no association between cell dose administered and either response or
toxicity. In a multivariable analysis, only a longer interval from BMT to relapse
and BMT to UDLI was associated with improved survival and DFS, respectively. UDLI
is an acceptable alternative to other treatment options for relapse after
unrelated donor BMT. (Blood. 2000;95:1214-1221)
PMID- 10666194
TI - Polymorphisms within glutathione S-transferase genes (GSTM1, GSTT1, GSTP1) and
risk of relapse in childhood B-cell precursor acute lymphoblastic leukemia: a
case-control study.
AB - Glutathione S-transferases (GSTs) have been associated with outcome in human
cancers treated with cytotoxic chemotherapy. In a case-control study, we
investigated the association between polymorphisms within the GSTM1, GSTT1, and
GSTP1 genes and risk of relapse in childhood acute lymphoblastic leukemia (ALL).
Cases were relapsed patients. Controls were successfully treated patients with a
minimum follow-up of 5 years. The null genotype (absence of both alleles) for
GSTM1 or GSTT1 conferred a 2-fold (OR = 0.5, 95% CI = 0. 23-1.07, P =.078) and
2.8-fold (OR = 0.36, 95% CI = 0.13-0.99, P =. 048) reduction in risk of relapse,
respectively, relative to the presence of the GSTM1 or GSTT1 gene. The GSTP1
Val(105)/Val(105) genotype showed a 3-fold decrease in risk of relapse (OR =
0.33, 95% CI = 0.09-1.23, P =.099) in comparison to the combined category of
Ile(105)/Val(105) and Ile(105)/Ile(105 )genotypes. No particular associations
with relapse were observed for the GSTP1 polymorphism at codon 114. The risk of
relapse when having 1 of the low-risk genotypes (GSTM1 null, GSTT1 null, GSTP1
Val(105)/Val(105)) decreased 1.9-fold (OR = 0.53, 95% CI = 0.24-1.19, P =.123),
and the risk when having 2 or 3 low-risk genotypes 3.5-fold (OR = 0.29, 95% CI =
0.06-1.37, P =.118), compared with individuals having no low-risk genotype (P for
trend =.005). Our results suggest that polymorphisms within genes of the GST
superfamily may be associated with risk of relapse in childhood ALL. (Blood.
2000;95:1222-1228)
PMID- 10666195
TI - Long-term outcome of continuous 24-hour deferoxamine infusion via indwelling
intravenous catheters in high-risk beta-thalassemia.
AB - The optimal regimen of intravenous deferoxamine for iron overload in high-risk
homozygous beta-thalassemia is unknown because only short-term follow-up has been
described in small patient groups. We report the outcome over a 16-year period of
a continuous 24-hour deferoxamine regimen, with dose adjustment for serum
ferritin, delivered via 25 indwelling intravenous lines for 17 patients.
Treatment indications were cardiac arrhythmias, left ventricular dysfunction,
gross iron overload, and intolerability of subcutaneous deferoxamine. Cardiac
arrhythmias were reversed in 6 of 6 patients, and the left ventricular ejection
fraction improved in 7 of 9 patients from a mean (+/- SEM) of 36 +/- 2% to 49 +/-
3% (P =.002, n = 9). The serum ferritin fell in a biphasic manner from a
pretherapy mean of 6281 +/- 562 microg/L to 3736 +/- 466 microg/L (P =.001),
falling rapidly and proportionally to the pretreatment ferritin (r(2) = 0.99) for
values >3000 microg/L but falling less rapidly below this value (at 133 +/- 22
microg/L/mo). The principal catheter-related complications were infection and
thromboembolism (1. 15 and 0.48 per 1000 catheter days, respectively), rates
similar to other patient groups. Only one case of reversible deferoxamine
toxicity was observed (retinal) when the therapeutic index was briefly exceeded.
An actuarial survival of 61% at 13 years with no treatment-related mortality
provides evidence of the value of this protocol. (Blood. 2000;95:1229-1236)
PMID- 10666196
TI - Quantitative assessment of retroviral transfer of the human multidrug resistance
1 gene to human mobilized peripheral blood progenitor cells engrafted in nonobese
diabetic/severe combined immunodeficient mice.
AB - Mobilized peripheral blood progenitor cells (PBPC) are a potential target for the
retrovirus-mediated transfer of cytostatic drug-resistance genes. We analyzed
nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse-repopulating
CD34+ PBPC from patients with cancer after retroviral transduction in various
cytokine combinations with the hybrid vector SF-MDR, which is based on the Friend
mink cell focus-forming/murine embryonic stem-cell virus and carries the human
multidrug resistance 1 (MDR1) gene. Five to 13 weeks after transplantation of
CD34+ PBPC into NOD/SCID mice (n = 84), a cell dose-dependent multilineage
engraftment of human leukocytes up to an average of 33% was observed. The SF-MDR
provirus was detected in the bone marrow (BM) and in its granulocyte fractions in
96% and 72%, respectively, of chimeric NOD/SCID mice. SF-MDR provirus integration
assessed by quantitative real-time polymerase chain reaction (PCR) was optimal in
the presence of Flt-3 ligand/thrombopoietin/stem-cell factor, resulting in a 6
fold (24% +/- 5% [mean +/- SE]) higher average proportion of gene-marked human
cells in NOD/SCID mice than that achieved with IL-3 alone (P <.01). A population
of clearly rhodamine-123(dull) human myeloid progeny cells could be isolated from
BM samples from chimeric NOD/SCID mice. On the basis of PCR and rhodamine-123
efflux data, up to 18% +/- 4% of transduced cells were calculated to express the
transgene. Our data suggest that the NOD/SCID model provides a valid assay for
estimating the gene-transfer efficiency to repopulating human PBPC that may be
achievable in clinical autologous transplantation. P-glycoprotein expression
sufficient to prevent marrow aplasia in vivo may be obtained with this SF-MDR
vector and an optimized transduction protocol. (Blood. 2000;95:1237-1248)
PMID- 10666197
TI - Targeted disruption of stat6 DNA binding activity by an oligonucleotide decoy
blocks IL-4-driven T(H)2 cell response.
AB - The transcription factor, signal transducer and activator of transcription (Stat)
6, regulates T(H)2-lymphocyte activity by controlling the expression and
responsiveness to interleukin (IL)-4, which plays a key role in numerous allergic
maladies. Therefore, we sought to use a phosphorothiolate cis-element decoy to
target disruption of Stat6 transcriptional activity. Here we showed that the
Stat6 decoy potently ablated the messenger RNA expression and production of IL-4,
but not of several other cytokines. The Stat6 decoy functionally disrupted IL-4
inducible cell proliferation of murine T(H)2 cells and primary human CD4(+) T
lymphocytes. Specificity of the decoy was demonstrated by its ability to directly
block Stat6 binding to a cis-element probe and transactivation, but not affect
Stat6 tyrosine phosphorylation or expression of the IL-4 receptor chains.
Moreover, the decoy failed to inhibit non-Stat6-dependent signaling pathways
since IL-2 was competent to induce cell proliferation and activation of Stats 1,
3, and 5a/b. With the use of laser scanning confocal microscopy, fluorescently
tagged Stat6 decoy was detectable in the cytoplasm and nucleus; however, greater
levels of oligonucleotide were present in the latter following IL-4 treatment.
Taken together, these data suggest that IL-4-driven T(H)2 cell activity can be
preferentially restricted via targeted disruption of Stat6 by a novel and
specific decoy strategy that may possess gene therapeutic potential. (Blood.
2000;95:1249-1257)
PMID- 10666198
TI - An oral CD40 ligand gene therapy against lymphoma using attenuated Salmonella
typhimurium.
AB - CD40 ligand (CD40L) has a great potential as a novel treatment for B-cell
lymphoma (BCL). It has previously been demonstrated that a nonvirulent strain of
Salmonella typhimurium mutant (ST) can be used not only as a vehicle in oral
genetic immunization via the intestinal mucosa, but also as an enhancer of
interferon gamma- and tumor necrosis factor alpha-mediated immunity. After
confirming that human CD40L can up-regulate expression of Fas, B7-1, and B7-2
molecules on murine BCL cells in vitro, we transfected the human CD40L gene into
S typhimurium mutant (ST40L), which was administrated orally to determine whether
it was able to prevent the growth of BCL in mice. Expression of human CD40L was
confirmed immunohistochemically with protein being detected in the Peyer's
patches of mice immunized with ST40L. Moreover, human soluble CD40L had been
detectable until 7 to 8 weeks after oral administration of ST40L. Although ST
alone exhibited some protective effects, ST40L demonstrated a significantly
greater protection against the development of CD40 positive BCL compared with the
control. In the surviving mice that had been treated with ST40L, a small and hard
nodule was formed at the injection site, which was found to be composed of
infiltrating lymphocytes expressing Fas ligand. These results have the potential
to be a simple, effective, and above all, safe immune-gene therapy against BCL.
(Blood. 2000;95:1258-1263)
PMID- 10666199
TI - GATA-1 blocks IL-6-induced macrophage differentiation and apoptosis through the
sustained expression of cyclin D1 and bcl-2 in a murine myeloid cell line M1.
AB - Cytokines exert pleiotropic effects on target cells in a manner dependent on the
cell type or stage of differentiation. To determine how instinctive cell
properties affect biological effects of cytokine, we introduced an
erythroid/megakaryocyte lineage-specific transcription factor, GATA-1, into a
murine myeloid cell line M1, which is known to undergo macrophage differentiation
in response to interleukin 6 (IL-6). Overexpression of GATA-1 changed the
phenotype of M1 cells from myeloid to megakaryocytic lineage. Furthermore, GATA-1
blocked both IL-6-induced macrophage differentiation and apoptosis of M1 cells.
Although STAT3 is essential for IL-6-induced macrophage differentiation of M1
cells, GATA-1 had little or no effect on tyrosine phosphorylation, DNA binding,
and transcriptional activities of STAT3 in Western blot analysis, electropholic
mobility shift assay (EMSA), and luciferase assays. During IL-6-induced
macrophage differentiation of M1 cells, IL-6 down-regulated cyclin D1 expression
and induced p19(INK4D) expression, leading to reduction in cdk4 activities. In
contrast, sustained expression of cyclin D1 and a significantly lesser amount of
p19(INK4D) induction were observed in IL-6-treated M1 cells overexpressing GATA
1. Furthermore, although bcl-2 expression was severely reduced by IL-6 in M1
cells, it was sustained in GATA-1-introduced M1 cells during the culture with IL
6. Both IL-6-induced macrophage differentiation and apoptosis were significantly
abrogated by coexpression of cyclin D1 and bcl-2, whereas overexpressions of
cyclin D1 or bcl-2 inhibited only differentiation or apoptosis, respectively.
These results suggested that GATA-1 may not only reprogram the lineage phenotype
of M1 cells but also disrupt the biologic effects of IL-6 through the sustained
expression of cyclin D1 and bcl-2. (Blood. 2000;95:1264-1273)
PMID- 10666200
TI - Hemopoietic lineage commitment decisions: in vivo evidence from a transgenic
mouse model harboring micro LCR-betapro-LacZ as a transgene.
AB - A substantial body of published data suggests activation of lineage-specific
genes in multipotential hemopoietic cells before their unilineage commitment.
Because the behavior and plasticity of cells isolated in vitro away from
microenvironmental constraints exercised in vivo may be altered, one wonders
whether similar findings can be observed in a physiologic setting in vivo. We
used a transgenic mouse model harboring human micro LCR together with beta
promoter sequences as a transgene to examine activation of lineage-specific
programs in vivo. By using LacZ as a reporter, we had the ability to detect,
quantitate, and select live cells with different levels of LacZ activation. We
found strong expression of LacZ by X-gal staining in 2 lineages-erythroid and
megakaryocytic. Activation in the latter was a novel finding not previously
observed when similar transgenes were used. We also found activation of muLCR
betapro at low levels in progenitor cells of granulocytic-macrophagic, erythroid,
or megakaryocytic lineage detected by in vitro assays, suggesting activation
before commitment to a specific lineage pathway. In particular, the expression of
LacZ was graded among progenitors, so that in a proportion of them activation
occurred only after commitment to erythroid or megakaryocytic lineage. In
addition, we found quantitative reduction in LacZ expression between fetal liver
and bone marrow-derived cells, the basis of which is unclear. Collectively our
data provide in vivo evidence supporting the view that lineage-specific genes are
expressed in a graded fashion in pluripotential cells before their irreversible
unilineage commitment. (Blood. 2000;95:1274-1282)
PMID- 10666201
TI - Actin cytoskeletal function is spared, but apoptosis is increased, in WAS patient
hematopoietic cells.
AB - Mutations in the Wiskott-Aldrich syndrome protein (WASP) have been hypothesized
to cause defective actin cytoskeletal function. This resultant dysfunction of the
actin cytoskeleton has been implicated in the pathogenesis of Wiskott-Aldrich
syndrome (WAS). In contrast, it was found that stimulated actin polymerization is
kinetically normal in the hematopoietic lineages affected in WAS. It was also
found that the actin cytoskeleton in WAS platelets is capable of producing the
hallmark cytoarchitectural features associated with activation. Further analysis
revealed accelerated cell death in WAS lymphocytes as evidenced by increased
caspase-3 activity. This increased activity resulted in accelerated apoptosis of
these cells. CD95 expression was also increased in these cells, suggesting an up
regulation in the FAS pathway in WAS lymphocytes. Additionally, inhibition of
actin polymerization in lymphocytes using cytochalasin B did not accelerate
apoptosis in these cells. This suggests that the accelerated apoptosis observed
in WAS lymphocytes was not secondary to an underlying defect in actin
polymerization caused by mutation of the WAS gene. These data indicate that WASP
does not play a universal role in signaling actin polymerization, but does play a
role in delaying cell death. Therefore, the principal consequence of mutations in
the WAS gene is to accelerate lymphocyte apoptosis, potentially through up
regulation of the FAS-mediated cell death pathway. This accelerated apoptosis may
ultimately give rise to the clinical manifestations observed in WAS. (Blood.
2000;95:1283-1292)
PMID- 10666202
TI - Adherence of phosphatidylserine-exposing erythrocytes to endothelial matrix
thrombospondin.
AB - Phospholipid asymmetry is well maintained in erythrocyte (RBC) membranes with
phosphatidylserine (PS) exclusively present in the inner leaflet. The appearance
of PS on the surface of the cell can have major physiologic consequences,
including increased cell-cell interactions. Because increased adherence of PS
exposing RBCs to endothelial cells (ECs) may be pathologically important in
hemoglobinopathies such as sickle cell disease and thalassemia, we studied the
role of PS exposure in calcium ionophore-treated normal RBC adherence to human
umbilical vein endothelial cell (HUVEC) monolayers. When HUVEC monolayers were
incubated with these PS-exposing RBCs, the ECs retracted and the RBCs adhered
primarily in the gaps opened between the ECs. A linear correlation was found
between the number of PS-exposing RBCs in the population and the number of
adhering RBCs to the monolayer. Pretreatment of RBCs with annexin V significantly
decreased adherence by shielding PS on the RBCs. Similarly, PS-containing lipid
vesicles decreased RBC binding by competing for the PS binding sites in the
monolayer. PS-exposing RBCs and PS-containing lipid vesicles adhered to
immobilized thrombospondin (TSP) and matrix TSP, respectively, and adherence of
PS-exposing RBCs to EC monolayers was reduced by antibodies to TSP and to its EC
receptor, alpha(v)beta(3). Together, these results indicate a role for PS and
matrix TSP in the adherence of PS-exposing RBCs to EC monolayers, and suggest an
important contribution of PS-exposing RBCs in pathologies with reported vascular
damage, such as sickle cell anemia. (Blood. 2000;95:1293-1300)
PMID- 10666203
TI - Streptokinase-induced platelet activation involves antistreptokinase antibodies
and cleavage of protease-activated receptor-1.
AB - Streptokinase activates platelets, limiting its effectiveness as a thrombolytic
agent. The role of antistreptokinase antibodies and proteases in streptokinase
induced platelet activation was investigated. Streptokinase induced localization
of human IgG to the platelet surface, platelet aggregation, and thromboxane A(2)
production. These effects were inhibited by a monoclonal antibody to the platelet
Fc receptor, IV.3. The platelet response to streptokinase was also blocked by an
antibody directed against the cleavage site of the platelet thrombin receptor,
protease-activated receptor-1 (PAR-1), but not by hirudin or an active site
thrombin inhibitor, Ro46-6240. In plasma depleted of plasminogen, exogenous wild
type plasminogen, but not an inactive mutant protein, S(741)A plasminogen,
supported platelet aggregation, suggesting that the protease cleaving PAR-1 was
streptokinase-plasminogen. Streptokinase-plasminogen cleaved a synthetic peptide
corresponding to PAR-1, resulting in generation of PAR-1 tethered ligand sequence
and selectively reduced binding of a cleavage-sensitive PAR-1 antibody in intact
cells. A combination of streptokinase, plasminogen, and antistreptokinase
antibodies activated human erythroleukemic cells and was inhibited by
pretreatment with IV.3 or pretreating the cells with the PAR-1 agonist SFLLRN,
suggesting Fc receptor and PAR-1 interactions are necessary for cell activation
in this system also. Streptokinase-induced platelet activation is dependent on
both antistreptokinase-Fc receptor interactions and cleavage of PAR-1. (Blood.
2000;95:1301-1308)
PMID- 10666204
TI - Transcriptional activation of urokinase by the Kruppel-like factor Zf9/COPEB
activates latent TGF-beta1 in vascular endothelial cells.
AB - Understanding the regulation of genes controlling fibrinolysis and matrix
homeostasis is essential for elucidating the basis of tissue repair. A recently
described novel Kruppel-like factor, Zf9, is up-regulated in acute liver injury
in activated hepatic stellate cells. Because Zf9 can be induced widely, its
activity was examined in vascular endothelium, a key cell in vascular injury. Zf9
is induced as an immediate-early response gene in bovine aortic endothelial cells
(BAECs) following treatment with serum or phorbol ester. Zf9 transcriptionally
activates urokinase plasminogen activator (uPA). Recombinant Zf9-GST binds to
wild-type but not mutated 'GC-box' motifs within the human uPA promoter (-63 to
32), with greatest affinity to the middle of 3 contiguous GC boxes. Transient
transfection of Zf9 drives transactivation of a full-length uPA promoter- and GC
box-construct, but not a uPA promoter-construct devoid of GC boxes.
Transactivation of uPA by Zf9 is also supported in Drosophila S2 cells. Most
importantly, transiently transfected Zf9 up-regulates endogenous uPA messenger
RNA and activity in BAECs, resulting in increased bioactive transforming growth
factor-beta (TGF-beta) via enhancement of proteolytic activation of the latent
molecule. Furthermore, concomitant expression of Zf9 and uPA proteins was
observed in arterial endothelial cells after balloon injury in rats, suggesting a
potential role of Zf9 in uPA expression not only in vitro but also in vivo. These
findings suggest a role of Zf9 in the injury response by enhancing uPA synthesis
and subsequent activation of latent TGF-beta. (Blood. 2000;95:1309-1316)
PMID- 10666205
TI - Leukocyte-leukocyte interactions mediated by platelet microparticles under flow.
AB - Platelet microparticles (PMPs) are released from activated platelets and express
functional adhesion receptors, including P-selectin, on their surface. PMP
concentrations are elevated in many disorders, and their role in accelerating
coagulation has been studied. However, their role in leukocyte aggregation has
not been defined. We hypothesized that P-selectin-expressing PMPs bridge
leukocytes that express P-selectin glycoprotein ligand-1 (PSGL-1), thereby
allowing them to interact under flow conditions. PMPs were isolated from platelet
rich plasma or were generated by activating washed platelets with calcium
ionophore. PMPs increased transient adhesion of flowing HL-60 cells or
neutrophils to HL-60 cells or neutrophils prebound to the surface of a parallel
plate flow chamber. Homotypic neutrophil interactions are initiated by the
binding of L-selectin to PSGL-1. However, even when L-selectin function was
blocked, PMPs allowed flowing neutrophils to aggregate and to interact with PSGL
1-expressing cells prebound to the surface of the flow chamber. The microparticle
mediated cell interactions occurred at lower shear stresses than those mediated
by L-selectin. PMPs may enhance leukocyte aggregation and leukocyte accumulation
on selectin-expressing substrates, especially in diseases where the concentration
of the particles is elevated. (Blood. 2000;95:1317-1323)
PMID- 10666206
TI - Prevention and treatment of factor VIII inhibitors in murine hemophilia A.
AB - Inhibitory antibody formation is a major complication of factor VIII replacement
therapy in patients with hemophilia A. To better understand the pathogenesis of
this immunologic reaction, we evaluated the role of T-cell costimulatory signals
for antifactor VIII antibody formation in a murine model of hemophilia A.
Repeated intravenous injections of factor VIII in these factor VIII-deficient
mice induced an antifactor VIII inhibitor antibody response. This response was
shown to be T-cell dependent by its absence in hemophilic mice also deficient for
the T-cell costimulatory ligand B7-2. In separate experiments, injection of
murine CTLA4-Ig completely blocked the primary response to factor VIII in
hemophilic mice with intact B7 function. This reagent also prevented or
diminished further increases in antifactor VIII when given to hemophilic mice
with low antifactor VIII antibody titers. These studies suggest that strategies
targeting the B7-CD28 pathway are potential therapies to prevent and treat
inhibitory antifactor VIII antibodies. Moreover, because the development of
antibodies to replaced proteins may limit the success of many human gene therapy
approaches, our results may be broadly applicable. (Blood. 2000;95:1324-1329)
PMID- 10666207
TI - Inhibition of thrombin generation by the zymogen factor VII: implications for the
treatment of hemophilia A by factor VIIa.
AB - Factor VII circulates as a single chain inactive zymogen (10 nmol/L) and a trace
( approximately 10-100 pmol/L) circulates as the 2-chain form, factor VIIa.
Factor VII and factor VIIa were studied in a coagulation model using plasma
concentrations of purified coagulation factors with reactions initiated with
relipidated tissue factor (TF). Factor VII (10 nmol/L) extended the lag phase of
thrombin generation initiated by 100 pmol/L factor VIIa and low TF. With the
coagulation inhibitors TFPI and AT-III present, factor VII both extended the lag
phase of the reaction and depressed the rate of thrombin generation. The
inhibition of factor Xa generation by factor VII is consistent with its
competition with factor VIIa for TF. Thrombin generation with TF concentrations
>100 pmol/L was not inhibited by factor VII. At low tissue factor concentrations
(<25 pmol/L) thrombin generation becomes sensitive to the absence of factor VIII.
In the absence of factor VIII, factor VII significantly inhibits TF-initiated
thrombin generation by 100 pmol/L factor VIIa. In this hemophilia A model,
approximately 2 nmol/L factor VIIa is needed to overcome the inhibition of
physiologic (10 nmol/L) factor VII. At 10 nmol/L, factor VIIa provided a thrombin
generation response in the hemophilia model (0% factor VIII, 10 nmol/L factor
VII) equivalent to that observed with normal plasma, (100% factor VIII, 10 nmol/L
factor VII, 100 pmol/L factor VIIa). These results suggest that the therapeutic
efficacy of factor VIIa in the medical treatment of hemophiliacs with inhibitors
is, in part, based on overcoming the factor VII inhibitory effect. (Blood.
2000;95:1330-1335)
PMID- 10666208
TI - Missense mutations in the human beta fibrinogen gene cause congenital
afibrinogenemia by impairing fibrinogen secretion.
AB - Congenital afibrinogenemia is a rare autosomal recessive disorder characterized
by bleeding that varies from mild to severe and by complete absence or extremely
low levels of plasma and platelet fibrinogen. Although several mutations in the
fibrinogen genes associated with dysfibrinogenemia and hypofibrinogenemia have
been described, the genetic defects of congenital afibrinogenemia are largely
unknown, except for a recently reported 11-kb deletion of the fibrinogen Aalpha
chain gene. Nevertheless, mutation mechanisms other than the deletion of a
fibrinogen gene are likely to exist because patients with afibrinogenemia showing
no gross alteration within the fibrinogen cluster have been reported. We tested
this hypothesis by studying the affected members of two families, one Italian and
one Iranian, who had no evidence of large deletions in the fibrinogen genes.
Sequencing of the fibrinogen genes in the 2 probands detected 2 different
homozygous missense mutations in exons 7 and 8 of the Bbeta-chain gene, leading
to amino acid substitutions Leu353Arg and Gly400Asp, respectively. Transient
transfection experiments with plasmids expressing wild-type and mutant
fibrinogens demonstrated that the presence of either mutation was sufficient to
abolish fibrinogen secretion. These findings demonstrated that missense mutations
in the Bbeta fibrinogen gene could cause congenital afibrinogenemia by impairing
fibrinogen secretion. (Blood. 2000;95:1336-1341)
PMID- 10666209
TI - Stimulation of cytotoxic T cells against idiotype immunoglobulin of malignant
lymphoma with protein-pulsed or idiotype-transduced dendritic cells.
AB - Because of their hypervariable regions and somatic mutations, the antigen
receptor molecules of lymphomas (idiotypes) are tumor-specific antigens and
attractive targets for antilymphoma immunotherapy. For the optimal induction of
human idiotype-specific cytotoxic T cells (CTL), idiotype was presented to CD8(+)
peripheral blood mononuclear cells by monocyte-derived autologous dendritic cells
(DC) after the endocytosis of idiotype protein or by idiotype-expressing DC.
Recombinant idiotype was obtained as a functionally folded Fab fragment by
periplasmic expression in Escherichia coli. Idiotype-expressing DC were generated
by transduction with recombinant Semliki forest virus vectors encompassing heavy-
or light-chain idiotype genes. Autologous lymphoblastoid cell lines stably
transfected with Epstein-Barr virus-based idiotype expression vectors were used
as target cells to detect idiotype-specific lysis. CTL stimulated with idiotype
loaded DC showed strong specific, CD8-mediated, and major histocompatibility
complex (MHC) class I-restricted cytotoxicity against autologous heavy- and light
chain idiotype. In contrast, stimulation with idiotype-transduced DC resulted in
only moderate natural killer cell activity. These data confirm the existence of
idiotype-specific CTL in patients with lymphoma, define a "good manufacturing
practice"-compatible protocol for the generation of these cells without the
requirement of viable lymphoma cells, and favor the processing of exogenous
antigen over DC transduction for the induction of MHC I-restricted CTL against
idiotypes with unknown antigenicity. (Blood. 2000;95:1342-1349)
PMID- 10666210
TI - Circulating forms of intercellular adhesion molecule (ICAM)-1 in mice lacking
membranous ICAM-1.
AB - Mice deficient in intercellular adhesion molecule-1 (ICAM-1), lacking membranous
ICAM-1, show a normal development but abnormalities of inflammatory and immune
functions. Although the membrane-bound form of ICAM-1 is not detectable in the
mutant strain, circulating ICAM-1 (cICAM) is present in serum from ICAM-1
deficient mice in similar amounts as in serum from wild-type mice. These findings
were confirmed in vitro by flow cytometric analysis of lipopolysaccharide
stimulated spleen cells, and cICAM-enzyme-linked immunosorbent assay analysis of
supernatants of cultured spleen cells. To analyze for the source of cICAM-1,
spleen cell RNA was isolated and ICAM-1 RNA was amplified by reverse
transcriptase-polymerase chain reaction using primers binding in the 5' and 3'
untranslated regions. Different fragments were cloned and sequenced. In wild-type
RNA the common 5 domain form of ICAM-1 was identified. In RNA from ICAM-1 mutant
mice only 3 smaller fragments were found. Sequencing these fragments identified 3
alternatively spliced isoforms of ICAM-1, lacking 2 or 3 extracellular domains.
However, in all spliced fragments the transmembrane domain was included.
Therefore, we postulate that circulating forms of ICAM-1 are generated by
proteolytic cleavage of membranous ICAM-1. The data indicate that the expression
of membranous ICAM-1 and the appearance of circulating forms in serum are
independently regulated mechanisms. (Blood. 2000;95:1350-1355)
PMID- 10666211
TI - Thymocyte development past the CD4(+)CD8(+) stage requires an active p38 mitogen
activated protein kinase.
AB - Activation of the p38 mitogen-activated protein kinase (MAPK) pathway is
important for some T-cell functions, but its role in intrathymic development is
unclear. To investigate the function of p38 MAPK during the late stages of
thymocyte differentiation, pharmacologic and genetic manipulations were used to
inhibit p38 MAPK activity in developing thymocytes. Ligation of the T-cell
antigen receptor (TCR) on either thymocytes or a thymocyte cell line resulted in
p38 MAPK activation. Selective pharmacologic inhibition of p38 MAPK activity with
the pyridinyl imidazole drug SB203580 severely impaired the development of mature
CD4(+) and CD8(+) single positive (SP) thymocytes from their CD4(+)CD8(+) double
positive (DP) precursors in fetal thymic organ culture (FTOC). Further,
pharmacologic or genetic suppression of p38 MAPK activity, the latter achieved by
overexpressing a catalytically inactive p38 MAPK, resulted in a blockade of the
DP-to-SP transition of a thymocyte cell line in a novel in vitro differentiation
assay. Taken together, these data constitute the first demonstration that p38
MAPK plays a critical role in the DP-to-SP differentiation of thymocytes during
late intrathymic development. (Blood. 2000;95:1356-1361)
PMID- 10666212
TI - Migration of activated CD8(+) T lymphocytes to sites of viral infection does not
require endothelial selectins.
AB - Using mice deficient of E-selectin and E/P-selectin, we have studied the
requirement for endothelial selectins in extravasation of leukocytes at sites of
viral infection, with major emphasis on the recruitment of virus-specific T(C)1
cells. Lymphocytic choriomeningitis virus (LCMV)-induced meningitis was used as
our primary experimental model. Additionally, localized subdermal inflammation
and virus clearance in internal organs were analyzed during LCMV infection. The
generation of CD8(+) effector T cells in infected mutants was unimpaired.
Quantitative and qualitative analysis of the inflammatory exudate cells in
intracerebrally infected mice gave identical results in all strains of mice.
Expression of endothelial selectin was also found to be redundant regarding the
ability of effector cells to eliminate virus in nonlymphoid organs. Concerning
LCMV-induced footpad swelling, absent or marginal reduction was found in E/P-sel
/- mice, compared with wild-type mice after local challenge with virus or
immunodominant viral MHC class I restricted peptide, respectively. Similar
results were obtained after adoptive transfer of wild-type effector cells into
E/P-sel -/- recipients, whereas footpad swelling was markedly decreased in P
sel/ICAM-1 -/- and ICAM-1 -/- recipients. LCMV-induced footpad swelling was
completely inhibited in ICAM-deficient mice transfused with donor cell
preincubated with soluble VCAM-1-Ig chimeric protein. Taken together, the current
findings strongly indicate that the migration of T(C)1 effector cells to sites of
viral infection can proceed in the absence of endothelial selectins, whereas
ligands of the Ig superfamily are critically involved in this process. (Blood.
2000;95:1362-1369)
PMID- 10666213
TI - Both stat5a and stat5b are required for antigen-induced eosinophil and T-cell
recruitment into the tissue.
AB - Antigen-induced eosinophil recruitment into the airways of sensitized mice is
mediated by CD4(+) T cells and their cytokines, especially IL-5. In this study,
we found that the antigen-induced airway eosinophilia was diminished in Stat5a
deficient (Stat5a(-/-)) mice and Stat5b-deficient (Stat5b(-/-)) mice. We also
found that antigen-induced CD4(+) T-cell infiltration and IL-5 production in the
airways were diminished in Stat5a(-/- )mice and Stat5b(-/-) mice. Moreover,
antigen-induced proliferation of splenocytes was diminished in Stat5a(-/- )mice
and Stat5b(-/-) mice, suggesting that the generation of antigen-primed T cells
may be compromised in Stat5a(-/-) mice and Stat5b(-/-) mice and this defect may
account for the diminished antigen-induced T-cell infiltration into the airways.
Interestingly, IL-4 and IL-5 production from anti-CD3-stimulated splenocytes was
diminished in Stat5a(-/-) mice and Stat5b(-/-) mice. However, antigen-specific
IgE and IgG1 production was diminished in Stat5a(-/-) mice but not in Stat5b(-/-)
mice, whereas antigen-specific IgG2a production was increased in Stat5a(-/-)
mice, suggesting the enhanced Th1 responses in Stat5a(-/-) mice. Finally, we
found that eosinophilopoiesis induced by the administration of recombinant IL-5
was also diminished in Stat5a(-/-) mice and Stat5b(-/-) mice. Together, these
results indicate that both Stat5a and Stat5b are essential for induction of
antigen-induced eosinophil recruitment into the airways and that the defects in
antigen-induced eosinophil recruitment in Stat5a(-/-) mice and Stat5b(-/-) mice
result from both impaired IL-5 production in the airways and diminished IL-5
responsiveness of eosinophils. (Blood. 2000;95:1370-1377)
PMID- 10666214
TI - Gene expressions of lipopolysaccharide receptors, toll-like receptors 2 and 4,
are differently regulated in mouse T lymphocytes.
AB - Toll-like receptors (TLRs) are a family of mammalian proteins homologous to
Drosophila Toll. Human TLR2 was shown to mediate the responsiveness to
lipopolysaccharide (LPS). On the other hand, gene mutations of mouse TLR4 (mTLR4)
in LPS-hyporesponsive strains have suggested that mTLR4 is essential for LPS
signaling in mice, but the role of mTLR2 has not been explored. This report
describes molecular cloning of the mTLR2 cDNA. Overexpression of mTLR2 and mouse
CD14 conferred LPS-inducibility of c-Jun N-terminal kinase phosphorylation and
nuclear factor-kappaB activation to COS7 cells, suggesting that mTLR2 is a
signaling receptor for LPS. Both mTLR2 and mTLR4 genes were expressed in T cells.
Treatment with anti-CD3epsilon, PMA plus ionomycin, or interleukin-2 (IL-2)/IL-15
increased mTLR2 but not mTLR4 messenger RNA (mRNA) in some T cell lines. Specific
inhibitors of mitogen-activated extracellular signal-regulated kinase and fusion
protein 38 (p38) kinase inhibited mTLR2 mRNA up-regulation by PMA plus ionomycin.
This suggests that extracellular signal-regulated kinase and p38 kinase pathways
were involved. Additionally, LPS treatment of EL-4 cell line decreased IL-4 gene
expression. Our results indicate that both mTLR2 and mTLR4 are involved in LPS
signaling, but their expressions are regulated differently in T cells, and that
LPS may directly affect T-cell functions by binding to TLRs. (Blood. 2000;95:1378
1385)
PMID- 10666215
TI - Abundant tax protein expression in CD4+ T cells infected with human T-cell
lymphotropic virus type I (HTLV-I) is prevented by cytotoxic T lymphocytes.
AB - The role of the cellular immune response in human T-cell leukemia virus type I
(HTLV-I) infection is not fully understood. A persistently activated cytotoxic T
lymphocyte (CTL) response to HTLV-I is found in the majority of infected
individuals. However, it remains unclear whether this CTL response is protective
or causes tissue damage. In addition, several observations paradoxically suggest
that HTLV-I is transcriptionally silent in most infected cells and, therefore,
not detectable by virus-specific CTLs. With the use of a new flow cytometric
procedure, we show here that a high proportion of naturally infected CD4+
peripheral blood mononuclear cells (PBMC) (between 10% and 80%) are capable of
expressing Tax, the immunodominant target antigen recognized by virus-specific
CTLs. Furthermore, we provide direct evidence that autologous CD8+ T cells
rapidly kill CD4+ cells naturally infected with HTLV-I and expressing Tax in
vitro by a perforin-dependent mechanism. Consistent with these observations, we
observed a significant negative correlation between the frequency of Tax(11-19)
specific CD8+ T cells and the percentage of CD4+ T cells in peripheral blood of
patients infected with HTLV-I. Those results are in accordance with the view that
virus-specific CTLs participate in a highly efficient immune surveillance
mechanism that persistently destroys Tax-expressing HTLV-I-infected CD4+ T cells
in vivo. (Blood. 2000;95:1386-1392)
PMID- 10666216
TI - Evidence that immunoglobulin specificities of AIDS-related lymphoma are not
directed to HIV-related antigens.
AB - Chronic B-cell stimulation may be a predisposing event in the early pathogenesis
of the acquired immunodeficiency syndrome (AIDS)-related lymphoma (ARL). ARL
derived immunoglobulin (Ig) genes are significantly diversified from germline,
suggesting that antigenic stimulation via Ig receptors may occur prior to
malignant transformation. We have evaluated 6 ARL-derived antibodies for binding
to human immunodeficiency virus (HIV) and cell surface epitopes. Five cases
expressed IgM, and 1 case expressed IgG. Expressed V genes were significantly
diversified (3%-15%) from known germline V genes. A non-Ig producing mouse
myeloma cell line was transfected with expression vectors containing the lymphoma
derived V genes. By enzyme-linked immunosorbent assay and Western blot assay, the
lymphoma-derived Ig's showed no reactivity against HIV recombinant proteins.
Also, no specific HIV reactivity was observed by flow cytometry with lymphoma
derived Ig's against the T-cell line infected with T-tropic HIV-1 or peripheral
blood mononuclear cells infected with M-tropic HIV strains, indicating lack of
binding to native HIV epitopes. However, 2 of the lymphoma-derived Ig's (ARL-7
and ARL-14) bound strongly to non-HIV-infected cells of various tissue origins.
Thus, these findings suggest that the transformed B cells of AIDS-associated
lymphomas may not arise from the pool of anti-HIV specific B cells but, rather,
may develop from B cells responding to other antigens, including self-antigens.
(Blood. 2000;95:1393-1399)
PMID- 10666217
TI - Mutation analysis of the 5' noncoding regulatory region of the BCL-6 gene in non
Hodgkin lymphoma: evidence for recurrent mutations and intraclonal heterogeneity.
AB - The BCL-6 proto-oncogene is involved in the genesis of non-Hodgkin lymphoma
(NHL). Rearrangements due to chromosomal translocations and somatic mutations of
the 5' noncoding regulatory region of the BCL-6 gene are potential mechanisms for
altering its expression in NHL. To further elucidate the nature of the somatic
mutations in the regulatory region of this gene, we have studied 10 healthy
donors and 11 NHL biopsy samples by extensive molecular cloning and sequencing.
In addition, we analyzed the BCL-6 genes of tumor and nontumor cells from 2 of
the cases. The germ line sequence of this region was defined, which differs in 7
positions from that previously reported. In addition, 1 polymorphic variation at
position 397(G or C) was identified. Deletions, insertions, and repeated
substitution mutations were detected among the molecular isolates in 8 tumor
specimens, with a mutational incidence ranging from 1.3 x 10(-3) to 1.3 x 10(
2)/bp (base pair). A total of 20 distinct substitution mutations, 1 insertion and
3 deletions were observed. One of these deletion mutations and 2 of the
substitutions were observed in more than 1 tumor specimen from different
individuals. In 3 tumor samples, identical mutations affecting both alleles were
observed. These findings suggest the presence of mutational hot spots and hot
specific events, a finding supported by our compilation of previously published
data. In 6 samples, the nucleotide sequences showed evidence of intraclonal
heterogeneity, consistent with a stepwise ongoing mutational process affecting
the BCL-6 gene in the tumor cells. These mutations accumulating in the regulatory
region of the BCL-6 gene could play a role in lymphoma progression and in the
transformation of follicular lymphomas to more aggressive large cell lymphomas.
(Blood. 2000;95:1400-1405)
PMID- 10666218
TI - HHV-8 is associated with a plasmablastic variant of Castleman disease that is
linked to HHV-8-positive plasmablastic lymphoma.
AB - Castleman disease (CD) is a lymphoproliferative disorder of unknown etiology that
is associated with the development of secondary tumors, including B-cell
lymphoma. Human herpesvirus 8 (HHV-8) (Kaposi's sarcoma-associated herpesvirus)
sequences have been described in some cases of multicentric Castleman disease
(MCD). Using a monoclonal antibody against an HHV-8-latent nuclear antigen, we
show that HHV-8 is specifically associated with a variant of MCD in which HHV-8
positive plasmablasts that show lambda light-chain restriction localize in the
mantle zone of B-cell follicles and coalesce to form microscopic lymphomas in
some cases. Furthermore, we show that the frank plasmablastic lymphoma that
develops in patients with this plasmablastic variant of MCD is also positive for
HHV-8 and lambda light chain. Plasmablastic lymphoma associated with MCD is a new
disease entity associated with HHV-8 infection. (Blood. 2000;95:1406-1412)
PMID- 10666219
TI - Analysis of expressed immunoglobulin heavy chain genes in familial B-CLL.
AB - In this study, we wished to determine whether familial chronic lymphocytic
leukemia of B-cell phenotype (CLL) shares with sporadic B-CLL the same
immunoglobulin (Ig) heavy chain variable region (VH) gene usage and occurrence of
somatic mutation, to gain insight into the pathogenetic relatedness of these
epidemiologically distinct forms of CLL. We therefore analyzed the expressed Ig
heavy chain genes in 23 cases (11 families) of familial CLL, and compared these
results with data previously reported for sporadic CLL. In addition, we assessed
the relationship of the occurrence of somatic mutation to several clinical and
phenotypic features. The distribution of V genes among these cases was similar to
that observed in sporadic CLL: VH3 > VH1 > VH4. Thirteen of the 23 cases (57%)
showed germ line VH gene sequences, whereas somatic mutations were detected in 10
cases (43%). The average mutation frequency of these latter 10 cases of was 6.7%
(ranging from 1.7% to 8.8%), and evidence of antigen selection was noted in 6.
Intraclonal variation, followed by clonal evolution and the appearance of a
second clone over a 20-year period was observed in 1 case, suggesting that
mutations can continue to accumulate after neoplastic transformation. The
presence of somatic mutations correlated with age at presentation, low white
blood cell (WBC) count, and low fluorescence intensity of surface CD5, and the
potential significance of these relationships is discussed. Our data indicate
that familial and sporadic B-CLL display a similar pattern of immunoglobulin gene
usage and frequency of somatic mutation, and are consistent with a common
ontogeny and immunogenetic origin for these 2 epidemiologically distinct forms of
CLL. (Blood. 2000;95:1413-1419)
PMID- 10666220
TI - Thioredoxin prolongs survival of B-type chronic lymphocytic leukemia cells.
AB - Thioredoxin (Trx) is a ubiquitous protein disulfide oxidoreductase with
antioxidant, cytokine, and chemotactic properties. Previously, we showed that
Trx, in synergy with interleukin 1 (IL-1), IL-2, IL-4, tumor necrosis factor
alpha (TNF-alpha), and CD40-ligation induced S-phase entry and mitosis in normal
B cells and B-type chronic lymphocytic leukemia (B-CLL) cells. The viability of B
CLL cells stimulated by these protocols is high, and it has been hypothesized
that the overexpression of Bcl-2 found in B-CLL protects the cells from apoptosis
in vitro and in vivo. In this study, we have analyzed the response of cells
derived from 12 samples of patients with B-CLL to recombinant human Trx in
spontaneous apoptosis, with special reference to the Bcl-2 expression. Long-term
cultures of B-CLL clones showed significantly higher viability when supplemented
with human Trx (P =.031), also exemplified with clones surviving more than 2
months. Short-term cultures of B-CLL cells exposed to 1 microg/mL of Trx for 1,
5, or 12 days maintained expression or delayed down-regulation of Bcl-2 compared
with control cultures containing RPMI 1640 medium and 10% fetal calf serum only
(P =.032,. 002,.026, respectively). All B-CLL cells expressed constitutive Trx at
varying but low levels, in contrast to adult T-cell leukemias, which overexpress
Trx, as previously reported. We found that Trx added to B-CLL cells increased in
a dose-dependent fashion the release of TNF-alpha, which has been suggested to be
an autocrine growth factor for these cells. In conclusion, we have found that
human recombinant Trx induced TNF-alpha secretion, maintained Bcl-2, and reduced
apoptosis in B-CLL cells. (Blood. 2000;95:1420-1426)
PMID- 10666221
TI - Apoptosis of leukemic cells accompanies reduction in intracellular pH after
targeted inhibition of the Na(+)/H(+) exchanger.
AB - The Na(+)/H(+) exchanger isoform 1 (NHE1) is primarily responsible for the
regulation of intracellular pH (pH(i)). It is a ubiquitous, amiloride-sensitive,
growth factor-activatable exchanger whose role has been implicated in cell-cycle
regulation, apoptosis, and neoplasia. Here we demonstrate that leukemic cell
lines and peripheral blood from primary patient leukemic samples exhibit a
constitutively and statistically higher pH(i) than normal hematopoietic tissue.
We then show that a direct correlation exists between pH(i) and cell-cycle status
of normal hematopoietic and leukemic cells. Advantage was taken of this
relationship by treating leukemic cells with the Na(+)/H(+) exchanger inhibitor,
5-(N, N-hexamethylene)-amiloride (HMA), which decreases the pH(i) and induces
apoptosis. By incubating patient leukemic cells in vitro with pharmacologic doses
of HMA for up to 5 hours, we show, using flow cytometry and fluorescent ratio
imaging microscopy, that when the pH(i) decreases, apoptosis-measured by annexin
V and TUNEL methodologies-rapidly increases so that more than 90% of the leukemic
cells are killed. The differential sensitivity exhibited between normal and
leukemic cells allows consideration of NHE1 inhibitors as potential antileukemic
agents. (Blood. 2000;95:1427-1434)
PMID- 10666222
TI - Three differentially expressed survivin cDNA variants encode proteins with
distinct antiapoptotic functions.
AB - Survivin is a member of the inhibitor of apoptosis protein (IAP) family that is
believed to play a role in oncogenesis. To elucidate further its physiologic
role(s), we have characterized the murine survivin gene and complementary DNA
(cDNA). The structural organization of the survivin gene, located on chromosome
11E2, is similar to that of its human counterpart, both containing 4 exons.
Surprisingly, 3 full-length murine survivin cDNA clones were isolated, predicting
the existence of 3 distinct survivin proteins. The longest open reading frame,
derived from all 4 exons, predicts a 140-amino acid residue protein,
survivin(140), similar to human survivin, which contains a single IAP repeat and
a COOH-terminal coiled-coil domain that links its function to the cell cycle. A
second cDNA, which retains intron 3, predicts the existence of a 121-amino acid
protein, survivin(121) that lacks the coiled-coil domain. Removal of exon 2
derived sequences by alternative pre-messenger RNA (mRNA) splicing results in a
third 40-amino acid residue protein, survivin(40), lacking the IAP repeat and
coiled-coil structure. Predictably, only recombinant survivin(140) and
survivin(121) inhibited caspase-3 activity. All 3 mRNA species were variably
expressed during development from 7.5 days postcoitum. Of the adult tissues
surveyed, thymus and testis accumulated high levels of survivin(140) mRNA,
whereas survivin(121)-specific transcripts were detected in all tissues, while
those representing survivin(40) were absent. Human counterparts to the 3 survivin
mRNA transcripts were identified in a study of human cells and tissues. The
presence of distinct isoforms of survivin that are expressed differentially
suggests that survivin plays a complex role in regulating apoptosis. (Blood.
2000;95:1435-1442)
PMID- 10666223
TI - Hodgkin and reed-sternberg cells represent an expansion of a single clone
originating from a germinal center B-cell with functional immunoglobulin gene
rearrangements but defective immunoglobulin transcription.
AB - Single cell studies aimed at clarifying the nature and clonality of Hodgkin and
Reed-Sternberg (HRS) cells of classical Hodgkin's disease (HD) have so far
produced conflicting results. Using an improved single cell procedure, the HRS
cells of 25 patients with nodular sclerosing HD lacking B- and T-cell antigens,
with and without Epstein-Barr virus infection, were analyzed for the presence of
immunoglobulin (Ig) gene rearrangements. One patient with HD developed follicular
lymphoma 2 years later. Both lymphomas originated from a common precursor
identified as a germinal center B cell. The data show that all but one of the
investigated cases harbored rearranged Ig genes, which were clonal in all
instances and carried a high load of somatic mutations. The Ig coding capacity
was preserved in 18 of the 24 cases (75%) with rearrangements. However,
expression of Ig messenger RNA was not detectable in the HRS cells with the
exception of Ig kappa light chain expression in some tumor cells of 1 case. The
lack of Ig gene transcription in HRS cells was confirmed by analyzing the HD cell
lines L428 and KM-H2 in transient transfection experiments. An Ig
promoter/enhancer reporter construct showed virtually no activity in these cells
compared to 5 control B-cell lines. We conclude that (1) classical HD is a B-cell
lymphoma in most instances, (2) HRS cells are clonal without any exception, (3)
they are derived from germinal center B-cells that (4) mostly lack crippling
mutations but (5) have consistently lost their Ig gene transcription ability, due
to functional defects in the Ig gene regulatory elements. (Blood. 2000;95:1443
1450)
PMID- 10666224
TI - Hematopoietic-specific expression of MEFV, the gene mutated in familial
Mediterranean fever, and subcellular localization of its corresponding protein,
pyrin.
AB - Familial Mediterranean fever (FMF) is a recessively inherited disorder
characterized by recurrent, self-limited attacks of fever and serositis and by
infiltration of affected tissues by large numbers of neutrophils. A candidate
gene for FMF was identified by positional cloning and named "MEFV." The
corresponding protein was named "pyrin." To elucidate the currently unknown
function of pyrin, we characterized its tissue distribution, regulation of
expression during hematopoietic differentiation, and subcellular localization.
Reverse transcription-polymerase chain reaction analysis, followed by
hybridization with an internal oligonucleotide, demonstrated expression of MEFV
in different populations of peripheral blood cells. Among hematopoietic cell
lines, MEFV was almost exclusively expressed in cells of the myeloid lineage.
Furthermore, MEFV messenger RNA was strongly expressed within 24 hours of
dimethyl sulfoxide-induced granulocytic differentiation of HL-60 cells. Analysis
of complementary DNA from human solid tumor-derived cell lines revealed
expression of MEFV in several cell lines derived from colon and prostate cancers.
Expression of MEFV fused to enhanced green fluorescent protein showed that pyrin
localized in distinct patches in the cytoplasm, forming a perinuclear cap. Taken
together, MEFV is predominantly expressed in myeloid cells and upregulated during
myeloid differentiation, and the corresponding protein, pyrin, is expressed in
the cytoplasm. (Blood. 2000;95:1451-1455)
PMID- 10666225
TI - Aberrant expression of active leukotriene C(4) synthase in CD16(+) neutrophils
from patients with chronic myeloid leukemia.
AB - Elevated leukotriene (LT)C(4) synthase activity was observed in peripheral blood
granulocyte suspensions from patients with chronic myeloid leukemia (CML).
Magnetic cell sorting (MACS) with CD16 monoclonal antibodies (mAbs), which were
used to fractionate granulocytes from CML patients and healthy individuals,
yielded highly purified suspensions of CD16(+) neutrophils. The purity of these
cell fractions was verified by extensive morphologic examination. Reverse
transcriptase-polymerase chain reaction (RT-PCR) analyses, demonstrating the
absence of interleukin-4 messenger RNA (IL-4 mRNA), further confirmed the
negligible contamination of eosinophils in these fractions. Notably, purified CML
CD16(+) neutrophils from all tested patients transformed exogenous LTA(4) to
LTC(4). These cells also produced LTC(4 )after activation with ionophore A23187
or the chemotactic peptide fMet-LeuPhe (N-formylmethionyl-leucyl-phenylalanine).
Subcellular fractionation revealed that the enzyme activity was exclusively
distributed to the microsomal fraction. Expression of LTC(4) synthase mRNA in CML
CD16(+) neutrophils was confirmed by RT-PCR. Furthermore, Western blot analyses
consistently demonstrated expression of LTC(4) synthase at the protein level in
CML CD16(+) neutrophils, whereas expression of microsomal glutathione S
transferase 2 occurred occasionally. Expectedly, LTC(4) synthase activity or
expression of the protein could not be demonstrated in CD16(+) neutrophil
suspensions from any of the healthy individuals. Instead, these cells, as well as
CML CD16(+) neutrophils, transformed LTA(4) to LTB(4). The results indicate that
aberrant expression of LTC(4) synthase is a regular feature of morphologically
mature CML CD16(+) neutrophils. This abnormality, possibly associated with
malignant transformation, can lead to increased LTC(4) synthesis in vivo. Such
overproduction may be of pathophysiological relevance because LTC(4 )has been
demonstrated to stimulate proliferation of human bone marrow-derived myeloid
progenitor cells. (Blood. 2000;95:1456-1464)
PMID- 10666226
TI - Extracellular granzyme A, complexed to proteoglycans, is protected against
inactivation by protease inhibitors.
AB - Granzyme A (GrA) and B (GrB) together with perforin are the main constituents of
cytotoxic granules of cytotoxic T lymphocytes (CTLs) and natural killer (NK)
cells. The cytotoxic proteins are released to deliver a lethal hit during contact
between the CTL or NK cell and target cell. With the use of an enzyme-linked
immunosorbent assay for antigenic levels, we showed in a recent study that plasma
of patients with activated CTLs and NK cells contain elevated levels of
extracellular GrA. In this study, we determined the form and proteolytic capacity
of this extracellular GrA detected in plasma. With the use of various assays, we
show that part of the extracellular GrA circulates in the mature conformation and
is bound to proteoglycans that protect it against inactivation by protease
inhibitors, such as antithrombin III and alpha-2-macroglobulin, whereas another
part of GrA circulates as a complex with antithrombin III. Finally, with the use
of a novel assay for active GrA, we demonstrate that some plasma samples with
high levels of extracellular GrA contain active GrA. These results suggest that
various forms of extracellular GrA occur in vivo and that the regulation of GrA
activity may be modified by proteoglycans. These data support the notion that
granzymes may exert extracellular functions distant from the site of CTL or NK
cell interaction with their target cells. (Blood. 2000;95:1465-1472)
PMID- 10666227
TI - Tropomyosin isoform 5b is expressed in human erythrocytes: implications of
tropomodulin-TM5 or tropomodulin-TM5b complexes in the protofilament and
hexagonal organization of membrane skeletons.
AB - The human erythrocyte membrane skeleton consists of hexagonal lattices with
junctional complexes containing F-actin protofilaments of approximately 33-37 nm
in length. We hypothesize that complexes formed by tropomodulin, a globular
capping protein at the pointed end of actin filaments, and tropomyosin (TM), a
rod-like molecule of approximately 33-35 nm, may contribute to the formation of
protofilaments. We have previously cloned the human tropomodulin complementary
DNA and identified human TM isoform 5 (hTM5), a product of the gamma-TM gene, as
one of the major TM isoforms in erythrocytes. We now identify TM5b, a product of
the alpha-TM gene, to be the second major TM isoform. TM5a, the alternatively
spliced isoform of the alpha-TM gene, which differs by 1 exon and has a weaker
actin-binding affinity, however, is not present. TM4, encoded by the delta-TM
gene, is not present either. In sodium dodecyl sulfate-polyacrylamide gel
electrophoresis, hTM5 comigrated with the slower TM major species in erythrocyte
membranes, and hTM5b comigrated with the faster TM major species. TM5b, like TM5,
binds strongly to tropomodulin, more so than other TM isoforms. The 2 major TM
isoforms, therefore, share several common features: They have 248 residues, are
approximately 33-35 nm long, and have high affinities toward F-actin and
tropomodulin. These common features may be the key to the mechanism by which
protofilaments are formed. Tropomodulin-TM5 or tropomodulin-TM5b complexes may
stabilize F-actin in segments of approximately 33-37 nm during erythroid terminal
differentiation and may, therefore, function as a molecular ruler. TM5 and TM5b
further define the hexagonal geometry of the skeletal network and allow actin
regulatory functions of TMs to be modulated by tropomodulin. (Blood. 2000;95:1473
1480)
PMID- 10666228
TI - Red cell surface changes and erythrophagocytosis in children with severe
plasmodium falciparum anemia.
AB - Severe anemia is one of the most lethal complications in children infected with
Plasmodium falciparum. The pathogenesis of this anemia is not completely
understood. Experimental data from malaria-infected humans and animal models
suggest that uninfected red cells have a shortened life span. This study looked
for changes in the red cell surfaces of children with severe malarial anemia that
could explain this accelerated destruction. A prospective case-control study was
conducted of children with severe P falciparum anemia (hemoglobin of 5 g/dL or
lower) admitted to a large general hospital in western Kenya. Children with
severe anemia were compared with children who had symptoms of uncomplicated
malaria and with asymptomatic children. Cytofluorometry was used to quantify in
vitro erythrophagocytosis and to measure red cell surface immunoglobulin G (IgG)
and the complement regulatory proteins CR1, CD55, and CD59. Red cells from
patients with severe anemia were more susceptible to phagocytosis and also showed
increased surface IgG and deficiencies in CR1 and CD55 compared with controls.
Red cell surface CD59 was elevated in cases of severe anemia compared with
asymptomatic controls but not as compared with symptomatic controls. The surface
of red cells of children with severe P falciparum anemia is modified by the
deposition of IgG and alterations in the levels of complement regulatory
proteins. These changes could contribute to the accelerated destruction of red
cells in these patients by mechanisms such as phagocytosis or complement-mediated
lysis. (Blood. 2000;95:1481-1486)
PMID- 10666229
TI - Single-tube multiplex PCR-SSCP analysis distinguishes 7 common ABO alleles and
readily identifies new alleles.
AB - The ABO blood group is clinically the most important blood group system.
Elucidation of the molecular basis of the ABO polymorphism allows genotype
determination without family studies. Described here is a new method based on the
simultaneous amplification by polymerase chain reaction (PCR) of 3 fragments from
exon 6, and 5' and 3' ends of exon 7 of the ABO gene, followed by single-strand
conformation polymorphism (SSCP) analysis. This multiplex PCR-SSCP protocol
allows the well-established base changes at 9 nucleotide positions 261, 297, 467,
526, 646, 657, 681, 1059, and 1096 to be assayed simultaneously so that 7 common
alleles (A(1), A(1v), A(2), B, O(1), O(1v), and O(2)) can be distinguished in a
single-tube single-lane format. Each allele was characterized by a set of 3
haplotype-specific SSCP patterns. Chinese (n = 125) and white European (n = 98)
samples were analyzed, and their genotypes were found consistent with the
serologic phenotypes or could be deduced unambiguously. Fifteen samples (2
Chinese and 13 white European) were each found carrying at least 1 rare allele.
Most of these alleles were new and some might be generated by intragenic
recombination. This technique is the simplest, quickest, and most informative
method reported to date and also readily identifies new alleles. (Blood.
2000;95:1487-1492)
PMID- 10666230
TI - The IVS4 + 4 A to T mutation of the fanconi anemia gene FANCC is not associated
with a severe phenotype in Japanese patients.
AB - Fanconi anemia (FA) is an autosomal recessive disease characterized by congenital
anomalies, aplastic anemia, and a susceptibility to leukemia. There are at least
8 complementation groups (A through H). Extensive analyses of the FA group C gene
FANCC in Western countries revealed that 10% to 15% of FA patients have mutations
of this gene. The most common mutation is IVS4 + 4 A to T (IVS4), a splice
mutation in intron 4, which has been found only in patients of Ashkenazi Jewish
ancestry. When we screened 29 Japanese patients (20 unrelated patients and 4
families) using polymerase chain reaction-single strand conformation
polymorphism, we found 8 unrelated patients homozygous for IVS4. This is
apparently the first non-Ashkenazi-Jewish population for whom this mutation has
been detected. The Ashkenazi Jewish patients homozygous for IVS4 have a severe
phenotype, in comparison with other FA patients. Our analyses of Japanese
patients indicate no significant difference between IVS4 homozygotes and other
patients with regard to severity of a clinical phenotype. Thus, ethnic background
may have a significant effect on a clinical phenotype in FA patients carrying the
same mutation. (Blood. 2000;95:1493-1498)
PMID- 10666231
TI - Glucose-6-phosphate dehydrogenase aveiro: a de novo mutation associated with
chronic nonspherocytic hemolytic anemia.
AB - Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked enzyme
abnormality. The clinical phenotype is variable but often predictable from the
molecular lesion. Class I variants (the most severe forms of the disease) cluster
within exon 10, in a region that, at the protein level, is believed to be
involved in dimerization. Here we describe a de novo mutation (C269Y) of a new
class I variant (G6PD Aveiro) that maps to exon 8. Mutant and normal alleles were
found in both hematopoietic and buccal cells, indicating the presence of
mosaicism. The available model of the protein predicts that this lesion lies in
proximity to the dimer interface of the molecule. A possible mechanism to explain
the severity of the defect is proposed. (Blood. 2000;95:1499-1501)
PMID- 10666232
TI - CD20 monoclonal antibody (rituximab) for therapy of Epstein-Barr virus lymphoma
after hemopoietic stem-cell transplantation.
AB - After bone marrow transplantation (BMT) using T-cell-depleted marrow from an
unrelated donor or HLA-mismatched related donor, the risk of developing
lymphoproliferative disease associated with the Epstein-Barr virus (EBV) ranges
from 1% to 25%. We have shown that administration of donor-derived EBV-specific
cytotoxic T lymphocytes (CTL) is effective prophylaxis and treatment for this
complication, and we routinely generate CTL for high-risk patients. However, EBV
lymphoma can occur in recipients of matched-sibling transplants for whom CTL are
unavailable or in patients for whom CTL administration is contraindicated. We
report on 3 such patients, who were successfully and safely treated with
rituximab, a CD20 monoclonal antibody. The patients remain disease free 7, 8, and
9 months, respectively, after therapy. We conclude that CD20 antibody may be a
useful alternative treatment strategy in patients with EBV lymphoma after BMT.
(Blood. 2000;95:1502-1505)
PMID- 10666233
TI - The exodus subfamily of CC chemokines inhibits the proliferation of chronic
myelogenous leukemia progenitors.
AB - Chemokines are a family of related proteins that regulate leukocyte infiltration
into inflamed tissue and play important roles in disease processes. Among the
biologic activities of chemokines is inhibition of proliferation of normal
hematopoietic progenitors. However, chemokines that inhibit normal progenitors
rarely inhibit proliferation of hematopoietic progenitors from patients with
chronic myelogenous leukemia (CML). We and others recently cloned a subfamily of
CC chemokines that share similar amino-terminal peptide sequences and a
remarkable ability to chemoattract T cells. These chemokines, Exodus-1/LARC/MIP
3alpha, Exodus-2/SLC/6Ckine/TCA4, and Exodus-3/CKbeta11/MIP-3beta, were found to
inhibit proliferation of normal human marrow progenitors. The study described
here found that these chemokines also inhibited the proliferation of progenitors
in every sample of marrow from patients with CML that was tested. This
demonstration of consistent inhibition of CML progenitor proliferation makes the
3 Exodus chemokines unique among chemokines. (Blood. 2000;95:1506-1508)
PMID- 10666234
TI - Mutations of the E2F4 gene in hematological malignancies having microsatellite
instability.
AB - Mutations of coding repeats within the E2F4, TGF-betaRII, BAX, IGFIIR, and hMSH3
are critical targets of microsatellite instability (MSI) in many kinds of
cancers. We analyzed 9 childhood acute lymphoblastic leukemia (ALL) samples, 5
acute myelocytic leukemia (AML) samples, and 10 adult T-cell leukemia (ATL)
samples having MSI to determine whether they had mutations of the E2F4, TGF
betaRII, BAX, IGFIIR, and hMSH3 genes. Frameshift mutations were found at
trinucleotide repeats within a coding exon of the E2F4 gene in 2 of 10 (20%) ATL
samples and 1 of 9 (11%) childhood ALL samples. No mutations were found in the
TGF-betaRII, BAX, IGFIIR, and hMSH3 genes. E2F4 is a transcription factor that
influences the cell-cycle progression. These results suggest that mutations of
the E2F4 gene, presumably caused by an abnormality of one of the DNA repair
genes, may play an important role in development of ATL and childhood ALL.
(Blood. 2000;95:1509-1510)
PMID- 10666235
TI - Active residues and viral substrate cleavage sites of the protease of the
birnavirus infectious pancreatic necrosis virus.
AB - The polyprotein of infectious pancreatic necrosis virus (IPNV), a birnavirus, is
processed by the viral protease VP4 (also named NS) to generate three
polypeptides: pVP2, VP4, and VP3. Site-directed mutagenesis at 42 positions of
the IPNV VP4 protein was performed to determine the active site and the important
residues for the protease activity. Two residues (serine 633 and lysine 674) were
critical for cleavage activity at both the pVP2-VP4 and the VP4-VP3 junctions.
Wild-type activity at the pVP2-VP4 junction and a partial block (with an
alteration of the cleavage specificity) at the VP4-VP3 junction were observed
when replacement occurred at histidines 547 and 679. A similar observation was
made when aspartic acid 693 was replaced by leucine, but wild-type activity and
specificity were found when substituted by glutamine or asparagine. Sequence
comparison between IPNV and two birnavirus (infectious bursal disease virus and
Drosophila X virus) VP4s revealed that serine 633 and lysine 674 are conserved in
these viruses, in contrast to histidines 547 and 679. The importance of serine
633 and lysine 674 is reminiscent of the protease active site of bacterial leader
peptidases and their mitochondrial homologs and of the bacterial LexA-like
proteases. Self-cleavage sites of IPNV VP4 were determined at the pVP2-VP4 and
VP4-VP3 junctions by N-terminal sequencing and mutagenesis. Two alternative
cleavage sites were also identified in the carboxyl domain of pVP2 by cumulative
mutagenesis. The results suggest that VP4 cleaves the (Ser/Thr)-X-Ala / (Ser/Ala)
Gly motif, a target sequence with similarities to bacterial leader peptidases and
herpesvirus protease cleavage sites.
PMID- 10666236
TI - Interaction of the cauliflower mosaic virus coat protein with the pregenomic RNA
leader.
AB - Using the yeast three-hybrid system, the interaction of the Cauliflower mosaic
virus (CaMV) pregenomic 35S RNA (pgRNA) leader with the viral coat protein, its
precursor, and a series of derivatives was studied. The purine-rich domain in the
center of the pgRNA leader was found to specifically interact with the coat
protein. The zinc finger motif of the coat protein and the preceding basic domain
were essential for this interaction. Removal of the N-terminal portion of the
basic domain led to loss of specificity but did not affect the strength of the
interaction. Mutations of the zinc finger motif abolished not only the
interaction with the RNA but also viral infectivity. In the presence of the very
acidic C-terminal domain, which is part of the preprotein but is not present in
the mature CP, the interaction with the RNA was undetectable.
PMID- 10666237
TI - The rice tungro bacilliform virus gene II product interacts with the coat protein
domain of the viral gene III polyprotein.
AB - Rice tungro bacilliform virus (RTBV) is a plant pararetrovirus whose DNA genome
contains four genes encoding three proteins and a large polyprotein. The function
of most of the viral proteins is still unknown. To investigate the role of the
gene II product (P2), we searched for interactions between this protein and other
RTBV proteins. P2 was shown to interact with the coat protein (CP) domain of the
viral gene III polyprotein (P3) both in the yeast two-hybrid system and in vitro.
Domains involved in the P2-CP association have been identified and mapped on both
proteins. To determine the importance of this interaction for viral
multiplication, the infectivity of RTBV gene II mutants was investigated by
agroinoculation of rice plants. The results showed that virus viability
correlates with the ability of P2 to interact with the CP domain of P3. This
study suggests that P2 could participate in RTBV capsid assembly.
PMID- 10666238
TI - Induction of the cellular E2F-1 promoter by the adenovirus E4-6/7 protein.
AB - The adenovirus type 5 (Ad5) E4-6/7 protein interacts directly with different
members of the E2F family and mediates the cooperative and stable binding of E2F
to a unique pair of binding sites in the Ad5 E2a promoter region. This induction
of E2F DNA binding activity strongly correlates with increased E2a transcription
when analyzed using virus infection and transient expression assays. Here we show
that while different adenovirus isolates express an E4-6/7 protein that is
capable of induction of E2F dimerization and stable DNA binding to the Ad5 E2a
promoter region, not all of these viruses carry the inverted E2F binding site
targets in their E2a promoter regions. The Ad12 and Ad40 E2a promoter regions
bind E2F via a single binding site. However, these promoters bind adenovirus
induced (dimerized) E2F very weakly. The Ad3 E2a promoter region binds E2F very
poorly, even via a single binding site. A possible explanation of these results
is that the Ad E4-6/7 protein evolved to induce cellular gene expression.
Consistent with this notion, we show that infection with different adenovirus
isolates induces the binding of E2F to an inverted configuration of binding sites
present in the cellular E2F-1 promoter. Transient expression of the E4-6/7
protein alone in uninfected cells is sufficient to induce transactivation of the
E2F-1 promoter linked to chloramphenicol acetyltransferase or green fluorescent
protein reporter genes. Further, expression of the E4-6/7 protein in the context
of adenovirus infection induces E2F-1 protein accumulation. Thus, the induction
of E2F binding to the E2F-1 promoter by the E4-6/7 protein observed in vitro
correlates with transactivation of E2F-1 promoter activity in vivo. These results
suggest that adenovirus has evolved two distinct mechanisms to induce the
expression of the E2F-1 gene. The E1A proteins displace repressors of E2F
activity (the Rb family members) and thus relieve E2F-1 promoter repression; the
E4-6/7 protein complements this function by stably recruiting active E2F to the
E2F-1 promoter to transactivate expression.
PMID- 10666239
TI - Bovine herpesvirus 5 glycoprotein E is important for neuroinvasiveness and
neurovirulence in the olfactory pathway of the rabbit.
AB - Glycoprotein E (gE) is important for full virulence potential of the
alphaherpesviruses in both natural and laboratory hosts. The gE sequence of the
neurovirulent bovine herpesvirus 5 (BHV-5) was determined and compared with that
of the nonneurovirulent BHV-1. Alignment of the predicted amino acid sequences of
BHV-1 and BHV-5 gE open reading frames showed that they had 72% identity and 77%
similarity. To determine the role of gE in the differential neuropathogenesis of
BHV-1 and BHV-5, we have constructed BHV-1 and BHV-5 recombinants: gE-deleted BHV
5 (BHV-5gEDelta), BHV-5 expressing BHV-1 gE (BHV-5gE1), and BHV-1 expressing BHV
5 gE (BHV-1gE5). Neurovirulence properties of these recombinant viruses were
analyzed using a rabbit seizure model (S. I. Chowdhury et al., J. Comp. Pathol.
117:295-310, 1997) that distinguished wild-type BHV-1 and -5 based on their
differential neuropathogenesis. Intranasal inoculation of BHV-5 gEDelta and BHV
5gE1 produced significantly reduced neurological signs that affected only 10% of
the infected rabbits. The recombinant BHV-1gE5 did not invade the central nervous
system (CNS). Virus isolation and immunohistochemistry data suggest that these
recombinants replicate and spread significantly less efficiently in the brain
than BHV-5 gE revertant or wild-type BHV-5, which produced severe neurological
signs in 70 to 80% rabbits. Taken together, the results of neurological signs,
brain lesions, virus isolation, and immunohistochemistry indicate that BHV-5 gE
is important for efficient neural spread and neurovirulence within the CNS and
could not be replaced by BHV-1 gE. However, BHV-5 gE is not required for initial
viral entry into olfactory pathway.
PMID- 10666240
TI - Roscovitine, a specific inhibitor of cellular cyclin-dependent kinases, inhibits
herpes simplex virus DNA synthesis in the presence of viral early proteins.
AB - We have previously shown that two inhibitors specific for cellular cyclin
dependent kinases (cdks), Roscovitine (Rosco) and Olomoucine (Olo), block the
replication of herpes simplex virus (HSV). Based on these results, we
demonstrated that HSV replication requires cellular cdks that are sensitive to
these drugs (L. M. Schang, J. Phillips, and P. A. Schaffer. J. Virol. 72:5626
5637, 1998). We further established that at least two distinct steps in the viral
replication cycle require cdks: transcription of immediate-early (IE) genes and
transcription of early (E) genes (L. M. Schang, A. Rosenberg, and P. A. Schaffer,
J. Virol. 73:2161-2172, 1999). Since Rosco inhibits HSV replication efficiently
even when added to infected cells at 6 h postinfection, we postulated that cdks
may also be required for viral functions that occur after E gene expression. In
the study presented herein, we tested this hypothesis directly by measuring the
efficiency of viral replication, viral DNA synthesis, and expression of several
viral genes during infections in which Rosco was added after E proteins had
already been synthesized. Rosco inhibited HSV replication, and specifically viral
DNA synthesis, when the drug was added at the time of release from a 12-h
phosphonoacetic acid (PAA)-induced block in viral DNA synthesis. Inhibition of
DNA synthesis was not a consequence of inhibition of expression of IE or E genes
in that Rosco had no effect on steady-state levels of two E transcripts under the
same conditions in which it inhibited viral DNA synthesis. Moreover, viral DNA
synthesis was inhibited by Rosco even in the absence of protein synthesis. In a
second series of experiments, the replication of four HSV mutants harboring
temperature-sensitive mutations in genes essential for viral DNA replication was
inhibited when Rosco was added at the time of shift-down from the nonpermissive
to the permissive temperature. Viral DNA synthesis was inhibited by Rosco under
these conditions, whereas expression of viral E genes was not affected. We
conclude that cellular Rosco-sensitive cdks are required for replication of viral
DNA in the presence of viral E proteins. This requirement may indicate that HSV
DNA synthesis is functionally linked to transcription, which requires cdks, or
that both viral transcription and DNA replication, independently, require viral
or cellular factors activated by Rosco-sensitive cdks.
PMID- 10666241
TI - T-cell receptor-mediated anergy of a human immunodeficiency virus (HIV) gp120
specific CD4(+) cytotoxic T-cell clone, induced by a natural HIV type 1 variant
peptide.
AB - Human immunodeficiency virus type 1 (HIV-1) infection triggers a cytotoxic T
lymphocyte (CTL) response mediated by CD8(+) and perhaps CD4(+) CTLs. The
mechanisms by which HIV-1 escapes from this CTL response are only beginning to be
understood. However, it is already clear that the extreme genetic variability of
the virus is a major contributing factor. Because of the well-known ability of
altered peptide ligands (APL) to induce a T-cell receptor (TCR)-mediated anergic
state in CD4(+) helper T cells, we investigated the effects of HIV-1 sequence
variations on the proliferation and cytotoxic activation of a human CD4(+) CTL
clone (Een217) specific for an epitope composed of amino acids 410 to 429 of HIV
1 gp120. We report that a natural variant of this epitope induced a functional
anergic state rendering the T cells unable to respond to their antigenic ligand
and preventing the proliferation and cytotoxic activation normally induced by the
original antigenic peptide. Furthermore, the stimulation of Een217 cells with
this APL generated altered TCR-proximal signaling events that have been
associated with the induction of T-cell anergy in CD4(+) T cells. Importantly,
the APL-induced anergic state of the Een217 T cells could be prevented by the
addition of interleukin 2, which restored their ability to respond to their
nominal antigen. Our data therefore suggest that HIV-1 variants can induce a
state of anergy in HIV-specific CD4(+) CTLs. Such a mechanism may allow a viral
variant to not only escape the CTL response but also facilitate the persistence
of other viral strains that may otherwise be recognized and eliminated by HIV
specific CTLs.
PMID- 10666242
TI - Cytoplasm-to-nucleus translocation of a herpesvirus tegument protein during cell
division.
AB - We have previously shown that the herpes simplex virus tegument protein VP22
localizes predominantly to the cytoplasm of expressing cells. We have also shown
that VP22 has the unusual property of intercellular spread, which involves the
movement of VP22 from the cytoplasm of these expressing cells into the nuclei of
nonexpressing cells. Thus, VP22 can localize in two distinct subcellular
patterns. By utilizing time-lapse confocal microscopy of live cells expressing a
green fluorescent protein-tagged protein, we now report in detail the
intracellular trafficking properties of VP22 in expressing cells, as opposed to
the intercellular trafficking of VP22 between expressing and nonexpressing cells.
Our results show that during interphase VP22 appears to be targeted exclusively
to the cytoplasm of the expressing cell. However, at the early stages of mitosis
VP22 translocates from the cytoplasm to the nucleus, where it immediately binds
to the condensing cellular chromatin and remains bound there through all stages
of mitosis and chromatin decondensation into the G(1) stage of the next cycle.
Hence, in VP22-expressing cells the subcellular localization of the protein is
regulated by the cell cycle such that initially cytoplasmic protein becomes
nuclear during cell division, resulting in a gradual increase over time in the
number of nuclear VP22-expressing cells. Importantly, we demonstrate that this
process is a feature not only of VP22 expressed in isolation but also of VP22
expressed during virus infection. Thus, VP22 utilizes an unusual pathway for
nuclear targeting in cells expressing the protein which differs from the nuclear
targeting pathway used during intercellular trafficking.
PMID- 10666243
TI - Sensitivity to a nonpeptidic compound (RPR103611) blocking human immunodeficiency
virus type 1 Env-mediated fusion depends on sequence and accessibility of the
gp41 loop region.
AB - The triterpene RPR103611 is an efficient inhibitor of membrane fusion mediated by
the envelope proteins (Env, gp120-gp41) of CXCR4-dependent (X4) human
immunodeficiency virus type 1 (HIV-1) strains, such as HIV-1(LAI) (LAI). Other X4
strains, such as HIV-1(NDK) (NDK), and CCR5-dependent (R5) HIV-1 strains, such as
HIV-1(ADA) (ADA), were totally resistant to RPR103611. Analysis of chimeric LAI
NDK Env proteins identified a fragment of the NDK gp41 ectodomain determining
drug resistance. A single difference at position 91, leucine in LAI and histidine
in NDK, apparently accounted for their sensitivity or resistance to RPR103611. We
had previously identified a mutation of isoleucine 84 to serine in a drug escape
LAI variant. Both I84 and L91 are located in the "loop region" of gp41 separating
the proximal and distal helix domains. Nonpolar residues in this region therefore
appear to be important for the antiviral activity of RPR103611 and are possibly
part of its target. However, another mechanism had to be envisaged to explain the
drug resistance of ADA, since its gp41 loop region was almost identical to that
of LAI. Fusion mediated by chimeric Env consisting of LAI gp120 and ADA gp41, or
the reciprocal construct, was fully blocked by RPR103611. The gp120-gp41 complex
of R5 strains is stable, relative to that of X4 strains, and this stability could
play a role in their drug resistance. Indeed, when the postbinding steps of ADA
infection were performed under mildly acidic conditions (pH 6.5 or 6.0), a
treatment expected to favor dissociation of gp120, we achieved almost complete
neutralization by RPR103611. The drug resistance of NDK was partially overcome by
preincubating virus with soluble CD4, a gp120 ligand inducing conformational
changes in the Env complex. The antiviral efficacy of RPR103611 therefore depends
on the sequence of the gp41 loop and the stability of the gp120-gp41 complex,
which could limit the accessibility of this target.
PMID- 10666244
TI - Biochemical requirements of virus wrapping by the endoplasmic reticulum:
involvement of ATP and endoplasmic reticulum calcium store during envelopment of
African swine fever virus.
AB - Enwrapment by membrane cisternae has emerged recently as a mechanism of
envelopment for large enveloped DNA viruses, such as herpesviruses, poxviruses,
and African swine fever (ASF) virus. For both ASF virus and the poxviruses,
wrapping is a multistage process initiated by the recruitment of capsid proteins
onto membrane cisternae of the endoplasmic reticulum (ER) or associated ER-Golgi
intermediate membrane compartments. Capsid assembly induces progressive bending
of membrane cisternae into the characteristic shape of viral particles, and
envelopment provides virions with two membranes in one step. We have used
biochemical assays for ASF virus capsid recruitment, assembly, and envelopment to
define the cellular processes important for the enwrapment of viruses by membrane
cisternae. Capsid assembly on the ER membrane, and envelopment by ER cisternae,
were inhibited when cells were depleted of ATP or depleted of calcium by
incubation with A23187 and EDTA or the ER calcium ATPase inhibitor, thapsigargin.
Electron microscopy analysis showed that cells depleted of calcium were unable to
assemble icosahedral particles. Instead, assembly sites contained crescent-shaped
and bulbous structures and, in rare cases, empty closed five-sided particles.
Interestingly, recruitment of the capsid protein from the cytosol onto the ER
membrane did not require ATP or an intact ER calcium store. The results show that
following recruitment of the virus capsid protein onto the ER membrane,
subsequent stages of capsid assembly and enwrapment are dependent on ATP and are
regulated by the calcium gradients present across the ER membrane cisternae.
PMID- 10666245
TI - Sint1, a common integration site in SL3-3-induced T-cell lymphomas, harbors a
putative proto-oncogene with homology to the septin gene family.
AB - The murine retrovirus SL3-3 is a potent inducer of T-cell lymphomas when
inoculated into susceptible newborn mice. Previously, DNAs from twenty SL3-3
induced tumors were screened by PCR for provirus integration sites. Two out of 20
tumors demonstrated clonal provirus insertion into a common region. This region
has now been isolated and characterized. The region, named SL3-3 integration site
1 (Sint1), maps to the distal end of mouse chromosome 11, corresponding to human
chromosome 17q25, and may be identical to a mouse mammary tumor virus integration
site in a T-cell lymphoma, Pad3. Two overlapping genomic lambda clones spanning
about 35 kb were isolated and used as a starting point for a search for genes in
the neighborhood of the virus integration sites. A genomic fragment was used as a
hybridization probe to isolate a 3-kb cDNA clone, the expression of which was
upregulated in one of two tumors harboring a provirus in Sint1. The cDNA clone is
predicted to encode a protein which shows 97.0% identity to a human septin-like
protein encoded by a gene which has been found as a fusion partner gene of MLL in
an acute myeloid leukemia with a t(11;17)(q23;q25). Together these findings raise
the possibility that a proto-oncogene belonging to the septin family, and located
about 15 kb upstream of the provirus integration sites, is involved in murine
leukemia virus-induced T-cell lymphomagenesis.
PMID- 10666247
TI - Characterization and sequencing of prototypic human T-lymphotropic virus type 1
(HTLV-1) from an HTLV-1/2 seroindeterminate patient.
AB - Serological screening for human T-lymphotropic virus type 1 (HTLV-1) parallels
the standard screening process for human immunodeficiency virus (HIV), in which
samples found positive by enzyme-linked immunosorbent assay (ELISA) are confirmed
with a modified Western blot procedure. There are a significant number of cases
in which HTLV-1/2 ELISA-positive specimens demonstrate an incomplete banding
pattern on this Western blot. Individuals providing these atypical antibody
responses are categorized as seroindeterminate for HTLV-1/2. Although HTLV-1
genomic sequences are readily detectable in the peripheral blood lymphocytes
(PBL) of seropositive individuals, previous studies have repeatedly demonstrated
that PBL from the vast majority of HTLV-1/2 seroindeterminate individuals are PCR
negative for HTLV-1. As a result, identification of the agent responsible for
this indeterminate reactivity has been of interest. We have generated an HTLV-1
positive B-cell line (SI-1 B) from one of these seroindeterminate individuals.
Previous screening for HTLV-1 in PBL from this patient had been routinely
negative by primary PCR; however, HTLV-1 tax had been periodically detected by
nested PCR. DNA sequence data generated with genomic DNA from the SI-1 B cell
line and HTLV-1-specific primers demonstrated the presence of a full-length viral
genome with >97% homology to the Cosmopolitan form of HTLV-1. A 12-bp deletion
was identified in the 3'-gag/5'-prot region, which would predict translation of
altered or nonfunctional proteins from these genes. We propose that this HTLV-1/2
seroindeterminate patient is infected with a prototypic form of HTLV-1 at an
extremely low viral load and that this finding may explain HTLV-1/2
seroindeterminate reactivity in at least a subset of these individuals.
PMID- 10666246
TI - Identification of poly(ADP-ribose) polymerase as a transcriptional coactivator of
the human T-cell leukemia virus type 1 Tax protein.
AB - Human T-cell leukemia virus type 1 (HTLV-1) encodes a transcriptional activator,
Tax, whose activity is believed to contribute significantly to cellular
transformation. Tax stimulates transcription from the proviral promoter as well
as from promoters for a variety of cellular genes. The mechanism through which
Tax communicates to the general transcription factors and RNA polymerase II has
not been completely determined. We investigated whether Tax could function
directly through the general transcription factors and RNA polymerase II or if
other intermediary factors or coactivators were required. Our results show that a
system consisting of purified recombinant TFIIA, TFIIB, TFIIE, TFIIF, CREB, and
Tax, along with highly purified RNA polymerase II, affinity-purified epitope
tagged TFIID, and semipurified TFIIH, supports basal transcription of the HTLV-1
promoter but is not responsive to Tax. Two additional activities were required
for Tax to stimulate transcription. We demonstrate that one of these activities
is poly(ADP-ribose) polymerase (PARP), a molecule that has been previously
identified to be the transcriptional coactivator PC1. PARP functions as a
coactivator in our assays at molar concentrations approximately equal to those of
the DNA and equal to or less than those of the transcription factors in the
assay. We further demonstrate that PARP stimulates Tax-activated transcription in
vivo, demonstrating that this biochemical approach has functionally identified a
novel target for the retroviral transcriptional activator Tax.
PMID- 10666248
TI - Characterization of human CD4(+) T-cell clones recognizing conserved and variable
epitopes of the Lassa virus nucleoprotein.
AB - T cells must play the major role in controlling acute human Lassa virus
infection, because patients recover from acute Lassa fever in the absence of a
measurable neutralizing antibody response. T cells alone seem to protect animals
from a lethal Lassa virus challenge, because after experimental vaccination no
neutralizing antibodies are detectable. In order to study human T-cell reactivity
to single Lassa virus proteins, the nucleoprotein (NP) of Lassa virus, strain
Josiah, was cloned, expressed in Escherichia coli, and affinity purified.
Peripheral blood mononuclear cells (PBMC) obtained from 8 of 13 healthy, Lassa
virus antibody-positive individuals living in the Republic of Guinea, western
Africa, were found to proliferate in response to the recombinant protein
(proliferation index >/=10). PBMC obtained from one individual with a
particularly high proliferative response were used to generate 50 NP-specific T
cell clones (TCC). For six of these the epitopes were mapped with overlapping
synthetic peptides derived from the sequence of the NP. These CD4(+) TCC
displayed high specific proliferation and produced mainly gamma interferon upon
stimulation with NP. Because variation of up to 15% in the amino acid sequences
of the structural proteins of naturally occurring Lassa virus variants has been
observed, the reactivity of the TCC with peptides derived from the homologous
epitopes of the Nigeria strain of Lassa virus and of the eastern Africa
arenavirus Mopeia was tested. With the Nigeria strain of Lassa virus the levels
of homology were 100% for two of these epitopes and 85% for three of them,
whereas homology with the respective Mopeia epitopes ranged from 92 to 69%.
Reactivity of the TCC with peptides derived from the variable epitopes of the
Nigeria strain and of Mopeia was reduced or completely abolished. This report
shows for the first time that seropositive individuals from areas of endemicity
have very strong memory CD4(+) T-cell responses against the NP of Lassa virus,
which are partly strain specific and partly cross-reactive with other Lassa virus
strains. Our findings may have important implications for the strategy of
designing recombinant vaccines against this mainly T-cell-controlled human
arenavirus infection.
PMID- 10666249
TI - The enhancer I core region contributes to the replication level of hepatitis B
virus in vivo and in vitro.
AB - Chronic hepatitis B virus (HBV) infection can lead to liver cirrhosis and
hepatocellular carcinoma. Long-term interaction of the immune system with the
virus results in the selection of escape mutants and viral persistence. In this
work we characterize mutations in the enhancer I region isolated prior to liver
transplantation from the HBV genomes of 10 patients with chronic HBV infection.
The HBV-genomes were sequenced, and the enhancer I region was cloned into
luciferase reporter constructs to determine the transcriptional activity.
Functional studies were performed by transfecting HBV replication-competent
plasmids into hepatoma cells. Analyses of the replication fitness of the mutant
strains were conducted by biochemical analysis. In all HBV genomes the enhancer I
region was mutated. Most of these mutations resulted in decreased transcriptional
activity. The strongest effects were detectable in strains with mutations in the
hepatocyte nuclear factor 3 and 4 (HNF3 and HNF4) binding sites of the enhancer I
core domain. Replication-competent HBV constructs containing these mutations
demonstrated up to 10-fold-reduced levels of virus replication. Before liver
transplantation, when the mutant strains were detected in the patients' sera, low
HBV DNA levels were found. After transplantation and reinfection with a wild-type
virus, the levels of replication were up to 240-fold higher. Our results show
that mutations in the enhancer I region of HBV have a major impact on HBV
replication. These mutations may also determine the switch from high to low
levels of viral replication which is frequently observed during chronic HBV
infection.
PMID- 10666250
TI - Cellular receptor traffic is essential for productive duck hepatitis B virus
infection.
AB - We have investigated the mechanism of duck hepatitis B virus (DHBV) entry into
susceptible primary duck hepatocytes (PDHs), using mutants of carboxypeptidase D
(gp180), a transmembrane protein shown to act as the primary cellular receptor
for avian hepatitis B virus uptake. The variant proteins were abundantly produced
from recombinant adenoviruses and tested for the potential to functionally
outcompete the endogenous wild-type receptor. Overexpression of wild-type gp180
significantly enhanced the efficiency of DHBV infection in PDHs but did not
affect ongoing DHBV replication, an observation further supporting gp180 receptor
function. A gp180 mutant deficient for endocytosis abolished DHBV infection,
indicating endocytosis to be the route of hepadnaviral entry. With further gp180
variants, carrying mutations in the cytoplasmic domain and characterized by an
accelerated turnover, the ability of gp180 to function as a DHBV receptor was
found to depend on a wild-type-like sorting phenotype which largely avoids
transport toward the endolysosomal compartment. Based on these data, we propose a
model in which a distinct intracellular DHBV traffic to the endosome, but not
beyond, is a prerequisite for completion of viral entry, i.e., for fusion and
capsid release. Furthermore, the deletion of the two enzymatically active
carboxypeptidase domains of gp180 did not lead to a loss of receptor function.
PMID- 10666251
TI - Virus-induced abrogation of transplantation tolerance induced by donor-specific
transfusion and anti-CD154 antibody.
AB - Treatment with a 2-week course of anti-CD154 antibody and a single transfusion of
donor leukocytes (a donor-specific transfusion or DST) permits skin allografts to
survive for >100 days in thymectomized mice. As clinical trials of this
methodology in humans are contemplated, concern has been expressed that viral
infection of graft recipients may disrupt tolerance to the allograft. We report
that acute infection with lymphocytic choriomeningitis virus (LCMV) induced
allograft rejection in mice treated with DST and anti-CD154 antibody if
inoculated shortly after transplantation. Isografts resisted LCMV-induced
rejection, and the interferon-inducing agent polyinosinic:polycytidylic acid did
not induce allograft rejection, suggesting that the effect of LCMV is not simply
a consequence of nonspecific inflammation. Administration of anti-CD8 antibody to
engrafted mice delayed LCMV-induced allograft rejection. Pichinde virus also
induced acute allograft rejection, but murine cytomegalovirus and vaccinia virus
(VV) did not. Injection of LCMV approximately 50 days after tolerance induction
and transplantation had minimal effect on subsequent allograft survival.
Treatment with DST and anti-CD154 antibody did not interfere with clearance of
LCMV, but a normally nonlethal high dose of VV during tolerance induction and
transplantation killed graft recipients. We conclude that DST and anti-CD154
antibody induce a tolerant state that can be broken shortly after transplantation
by certain viral infections. Clinical application of transplantation tolerance
protocols may require patient isolation to facilitate the procedure and to
protect recipients.
PMID- 10666252
TI - Interactions of viral protein 3CD and poly(rC) binding protein with the 5'
untranslated region of the poliovirus genome.
AB - The poly(rC) binding protein (PCBP) is a cellular protein required for poliovirus
replication. PCBP specifically interacts with two domains of the poliovirus 5'
untranslated region (5'UTR), the 5' cloverleaf structure, and the stem-loop IV of
the internal ribosome entry site (IRES). Using footprinting analysis and site
directed mutagenesis, we have mapped the RNA binding site for this cellular
protein within the stem-loop IV domain. A C-rich sequence in a loop at the top of
this large domain is required for PCBP binding and is crucial for viral
translation. PCBP binds to stem-loop IV RNA with six-times-higher affinity than
to the 5' cloverleaf structure. However, the binding of the viral protein 3CD
(precursor of the viral protease 3C and the viral polymerase 3D) to the
cloverleaf RNA dramatically increases the affinity of PCBP for this RNA element.
The viral protein 3CD binds to the cloverleaf RNA but does not interact directly
with stem-loop IV nor with other RNA elements of the viral IRES. Our results
indicate that the interactions of PCBP with the poliovirus 5'UTR are modulated by
the viral protein 3CD.
PMID- 10666253
TI - A structured RNA motif is involved in correct placement of the tRNA(3)(Lys)
primer onto the human immunodeficiency virus genome.
AB - Human immunodeficiency virus type 1 (HIV-1) reverse transcription is primed by
the cellular tRNA(3)(Lys) molecule that binds with its 3'-terminal 18 nucleotides
to the fully complementary primer-binding site (PBS) on the viral RNA genome.
Besides this complementarity, annealing of the primer may be stimulated by
additional base-pairing interactions between other parts of the tRNA molecule and
viral sequences flanking the PBS. According to the RNA secondary structure model
of the HIV-1 leader region, part of the PBS sequence is involved in base pairing
to form a small stem-loop structure, termed the U5-PBS hairpin. This hairpin may
be involved in the process of reverse transcription. To study the role of the U5
PBS hairpin in the viral replication cycle, we introduced mutations in the U5
region that affect the stability of this structured RNA motif. Stabilization and
destabilization of the hairpin significantly inhibited virus replication. Upon
prolonged culturing of the virus mutant with the stabilized hairpin, revertant
viruses were obtained with additional mutations that restore the thermodynamic
stability of the U5-PBS hairpin. The thermodynamic stability of the U5-PBS
hairpin apparently has to stay within narrow limits for efficient HIV-1
replication. Transient transfection experiments demonstrated that transcription
of the proviral genomes, translation of the viral mRNAs, and assembly of the
virions with a normal RNA content is not affected by the mutations within the U5
PBS hairpin. We show that stabilization of the hairpin reduced the amount of tRNA
primer that is annealed to the PBS. Destabilization of the hairpin did not affect
tRNA annealing, but the viral RNA-tRNA complex was less stable. These results
suggest that the U5-PBS hairpin is involved in correct placement of the tRNA
primer on the viral genome. The analysis of virus mutants and revertants and the
RNA structure probing experiments presented in this study are consistent with the
existence of the U5-PBS hairpin as predicted in the RNA secondary structure
model.
PMID- 10666254
TI - The membrane-proximal stem region of vesicular stomatitis virus G protein confers
efficient virus assembly.
AB - In this report, we show that the glycoprotein of vesicular stomatitis virus (VSV
G) contains within its extracellular membrane-proximal stem (GS) a domain that is
required for efficient VSV budding. To determine a minimal sequence in GS that
provides for high-level virus assembly, we have generated a series of recombinant
DeltaG-VSVs which express chimeric glycoproteins having truncated stem sequences.
The recombinant viruses having chimeras with 12 or more membrane-proximal
residues of the G stem, and including the G protein transmembrane-cytoplasmic
tail domains, produced near-wild-type levels of particles. In contrast, viruses
encoding chimeras with shorter or no G-stem sequences produced approximately 10-
to 20-fold less. This budding domain when present in chimeric glycoproteins also
promoted their incorporation into the VSV envelope. We suggest that the G-stem
budding domain promotes virus release by inducing membrane curvature at sites
where virus budding occurs or by recruiting condensed nucleocapsids to sites on
the plasma membrane which are competent for efficient virus budding.
PMID- 10666255
TI - In vitro- and in vivo-generated defective RNAs of satellite panicum mosaic virus
define cis-acting RNA elements required for replication and movement.
AB - Satellite panicum mosaic virus (SPMV) depends on its helper virus, panicum mosaic
virus (PMV), to provide trans-acting proteins for replication and movement. The
824-nucleotide (nt) genome of SPMV possesses an open reading frame encoding a
17.5-kDa capsid protein (CP), which is shown to be dispensable for SPMV
replication. To localize cis-acting RNA elements required for replication and
movement, a comprehensive set of SPMV cDNA deletion mutants was generated. The
results showed that the 263-nt 3' untranslated region (UTR) plus 73 nt upstream
of the CP stop codon and the first 16 nt in the 5' UTR are required for SPMV RNA
amplification and/or systemic spread. A region from nt 17 to 67 within the 5' UTR
may have an accessory role in RNA accumulation, and a fragment bracketing nt 68
to 104 appears to be involved in the systemic movement of SPMV RNA in a host
dependent manner. Unexpectedly, defective RNAs (D-RNAs) accumulated de novo in
millet plants coinfected with PMV and either of two SPMV mutants: SPMV-91, which
is incapable of expressing the 17.5-kDa CP, and SPMV-GUG, which expresses low
levels of the 17.5-kDa CP. The D-RNA derived from SPMV-91 was isolated from
infected plants and used as a template to generate a cDNA clone. RNA transcripts
derived from this 399-nt cDNA replicated and moved in millet plants coinoculated
with PMV. The characterization of this D-RNA provided a biological confirmation
that the critical RNA domains identified by the reverse genetic strategy are
essential for SPMV replication and movement. The results additionally suggest
that a potential "trigger" for spontaneous D-RNA accumulation may be associated
with the absence or reduced accumulation of the 17.5-kDa SPMV CP. This represents
the first report of a D-RNA associated with a satellite virus.
PMID- 10666256
TI - Relative sensitivity of hepatitis B virus and other hepatotropic viruses to the
antiviral effects of cytokines.
AB - We have previously shown that hepatitis B virus (HBV) replication is inhibited
noncytopathically in the livers of transgenic mice following injection of HBV
specific cytotoxic T lymphocytes (CTLs) or infection with unrelated hepatotropic
viruses, including lymphocytic choriomeningitis virus (LCMV) and adenovirus.
These effects are mediated by gamma interferon (IFNgamma), tumor necrosis factor
alpha (TNFalpha), and IFNalpha/beta. In the present study, we crossed HBV
transgenic mice with mice genetically deficient for IFNgamma (IFNgammaKO), the
TNFalpha receptor (TNFalphaRKO), or the IFNalpha/beta receptor (IFNalpha/betaRKO)
in order to determine the relative contribution of each cytokine to the antiviral
effects observed in each of these systems. Interestingly, we showed that HBV
replicates in unmanipulated IFNgammaKO and IFNalpha/betaRKO mice at levels higher
than those observed in control mice, implying that baseline levels of these
cytokines control HBV replication in the absence of inflammation. We also showed
that IFNgamma mediates most of the antiviral effect of the CTLs while
IFNalpha/beta is primarily responsible for the early inhibitory effect of LCMV
and adenovirus on HBV replication. In addition, we showed that the hepatic
induction of IFNalpha/beta observed after injection of poly(I. C) is sufficient
to inhibit HBV replication and that a similar antiviral effect is achieved by
systemic administration of very high doses of IFNalpha. We also compared the
relative sensitivity of LCMV and adenovirus to control by IFNgamma, TNFalpha, or
IFNalpha/beta in these animals. Importantly, IFNalpha/betaRKO mice, and to a
lesser extent IFNgammaKO mice, showed higher hepatic levels of LCMV RNA and
adenovirus DNA and RNA than control mice, underscoring the importance of both
interferons in controlling these other viral infections as well.
PMID- 10666257
TI - Nuclear accumulation of IE62, the varicella-zoster virus (VZV) major
transcriptional regulatory protein, is inhibited by phosphorylation mediated by
the VZV open reading frame 66 protein kinase.
AB - IE62, the major transcriptional activator protein encoded by varicella-zoster
virus (VZV), locates to the nucleus when expressed in transfected cells. We show
here that cytoplasmic forms of IE62 accumulate in transfected and VZV-infected
cells as the result of the protein kinase activity associated with VZV open
reading frame 66 (ORF66). Expression of the ORF66 protein kinase but not the VZV
ORF47 protein kinase impaired the ability of coexpressed IE62 to transactivate
promoter-reporter constructs. IE62 that was coexpressed with the ORF66 protein
accumulated predominantly in the cytoplasm, whereas the normal nuclear
localization of other proteins was not affected by the ORF66 protein. In cells
infected with VZV, IE62 accumulated in the cytoplasm at late times of infection,
whereas in cells infected with a VZV recombinant unable to express ORF66 protein
(ROka66S), IE62 was completely nuclear. Point mutations introduced into the
predicted serine/threonine catalytic domain and ATP binding domain of ORF66
abrogated its ability to influence IE62 nuclear localization, indicating that the
protein kinase activity was required. The region of IE62 that was targeted by
ORF66 was mapped to amino acids 602 to 733. IE62 peptides containing this region
were specifically phosphorylated in cells coexpressing the ORF66 protein kinase
and in cells infected with wild-type VZV but were not phosphorylated in cells
infected with ROka66S. We conclude that the ORF66 protein kinase phosphorylates
IE62 to induce its cytoplasmic accumulation, most likely by inhibiting IE62
nuclear import.
PMID- 10666258
TI - The extracellular domain of herpes simplex virus gE is sufficient for
accumulation at cell junctions but not for cell-to-cell spread.
AB - Herpes simplex virus (HSV) expresses a number of membrane glycoproteins,
including gB, gD, and gH/gL, that function in both entry of virus particles and
movement of virus from an infected cell to an uninfected cell (cell-to-cell
spread). However, a complex of HSV glycoproteins gE and gI (gE/gI) is required
for efficient cell-to-cell spread, especially between cells that form extensive
cell junctions, yet it is not necessary for entry of extracellular virions. We
previously showed that gE/gI has the capacity to localize specifically to cell
junctions; the glycoprotein complex was found at lateral surfaces of cells in
contact with other cells but not at those lateral surfaces not forming junctions
or at apical surfaces. By virtue of these properties, gE/gI is an important
molecular handle on the poorly understood process of cell-to-cell spread. Here,
we show that the cytoplasmic domain of gE is important for the proper delivery of
gE/gI to lateral surfaces of cells. Without this domain, gE/gI is found on the
apical surface of epithelial cells, and more uniformly in the cytoplasm, although
incorporation into the virion envelope is unaffected. However, even without
proper trafficking signals, a substantial fraction of gE/gI retained the capacity
to accumulate at cell junctions. Therefore, the extracellular domain of gE can
mediate accumulation of gE/gI at cell junctions, if the glycoprotein can be
delivered there, probably through interactions with ligands on the opposing cell.
The role of phosphorylation of the cytoplasmic domain of gE was also studied. A
second mutant HSV type 1 was constructed in which three serine residues that form
a casein kinase II phosphorylation site were changed to alanine residues,
reducing phosphorylation by 70 to 80%. This mutation did not affect accumulation
at cell junctions or cell-to-cell spread.
PMID- 10666259
TI - JC virus enters human glial cells by clathrin-dependent receptor-mediated
endocytosis.
AB - The human polyomavirus JC virus (JCV) is the etiologic agent of a fatal central
nervous system (CNS) demyelinating disease known as progressive multifocal
leukoencephalopathy (PML). PML occurs predominantly in immunosuppressed patients
and has increased dramatically as a result of the AIDS pandemic. The major target
cell of JCV infection and lytic replication in the CNS is the oligodendrocyte.
The mechanisms by which JCV initiates and establishes infection of these glial
cells are not understood. The initial interaction between JCV and glial cells
involves virus binding to N-linked glycoproteins containing terminal alpha(2-6)
linked sialic acids. The subsequent steps of entry and targeting of the viral
genome to the nucleus have not been described. In this report, we compare the
kinetics and mechanisms of infectious entry of JCV into human glial cells with
that of the related polyomavirus, simian virus 40 (SV40). We demonstrate that
JCV, unlike SV40, enters glial cells by receptor-mediated clathrin-dependent
endocytosis.
PMID- 10666260
TI - Subcellular localization, stability, and trans-cleavage competence of the
hepatitis C virus NS3-NS4A complex expressed in tetracycline-regulated cell
lines.
AB - A tetracycline-regulated gene expression system and a panel of novel monoclonal
antibodies were used to examine the subcellular localization, stability, and
trans-cleavage competence of the hepatitis C virus (HCV) NS3-NS4A complex in
inducible cell lines. The NS3 serine protease domain and the full-length NS3
protein expressed in the absence of the NS4A cofactor were diffusely distributed
in the cytoplasm and nucleus. Coexpression of NS4A, however, directed NS3 to the
endoplasmic reticulum (ER) or an ER-like modified compartment, as demonstrated by
colocalization with 3,3'-dihexyloxacarbocyanine iodide, protein disulfide
isomerase, and calnexin, as well as subcellular fractionation analyses. In
addition, coexpression with NS4A dramatically increased the intracellular
stability of NS3 (mean protein half-life of 26 versus 3 h) and allowed for NS4A
dependent trans-cleavage at the NS4B-NS5A junction. Deletion analyses revealed
that the hydrophobic amino-terminal domain of NS4A was required for ER targeting
of NS3. These results demonstrate the importance of studying HCV proteins in
their biological context and define a well-characterized cell culture system for
further analyses of the NS3-NS4A complex and the evaluation of novel antiviral
strategies against hepatitis C.
PMID- 10666261
TI - Host sequences flanking the human T-cell leukemia virus type 1 provirus in vivo.
AB - Human pathogenic retroviruses do not have common loci of integration. However,
many factors, such as chromatin structure, transcriptional activity, DNA-protein
interaction, CpG methylation, and nucleotide composition of the target sequence,
may influence integration site selection. These features have been investigated
by in vitro integration reactions or by infection of cell lines with recombinant
retroviruses. Less is known about target choice for integration in vivo. The
present study was conducted in order to assess the characteristics of cellular
sequences targeted for human T-cell leukemia virus type 1 (HTLV-1) integration in
vivo. Sequencing integration sites from >/=200 proviruses (19 kb of sequence)
isolated from 29 infected individuals revealed that HTLV-1 integration is not
random at the level of the nucleotide sequence. The virus was found to integrate
in A/T-rich regions with a weak consensus sequence at positions within and
without of the hexameric repeat generated during integration. These features were
not associated with a preference for integration near active regions or repeat
elements of the host chromosomes. Most or all of the regions of the genome appear
to be accessible to HTLV-1 integration. As with integration in vitro, integration
specificity in vivo seems to be determined by local features rather than by the
accessibility of specific regions.
PMID- 10666262
TI - Most retroviral recombinations occur during minus-strand DNA synthesis.
AB - Retroviral RNA molecules are plus, or sense in polarity, equivalent to mRNA.
During reverse transcription, the first strand of the DNA molecule synthesized is
minus-strand DNA. After the minus strand is polymerized, the plus-strand DNA is
synthesized using the minus-strand DNA as the template. In this study, a helper
cell line that contains two proviruses with two different mutated gfp genes was
constructed. Recombination between the two frameshift mutant genes resulted in a
functional gfp. If recombination occurs during minus-strand DNA synthesis, the
plus-strand DNA will also contain the functional sequence. After the cell
divides, all of its offspring will be green. However, if recombination occurs
during plus-strand DNA synthesis, then only the plus-strand DNA will contain the
wild-type gfp sequence and the minus-strand DNA will still carry the frameshift
mutation. The double-stranded DNA containing this mismatch was subsequently
integrated into the host chromosomal DNA of D17 cells, which were unable to
repair the majority of mismatches within the retroviral double-strand DNA. After
the cell divided, one daughter cell contained the wild-type gfp sequence and the
other daughter cell contained the frameshift mutation in the gfp sequence. Under
fluorescence microscopy, half the cells in the offspring were green and the other
half of the cells were colorless or clear. Thus, we demonstrated that more than
98%, if not all, retroviral recombinations occurred during minus-strand DNA
synthesis.
PMID- 10666263
TI - Rotavirus infection induces an increase in intracellular calcium concentration in
human intestinal epithelial cells: role in microvillar actin alteration.
AB - Rotaviruses, which infect mature enterocytes of the small intestine, are
recognized as the most important cause of viral gastroenteritis in young
children. We have previously reported that rotavirus infection induces
microvillar F-actin disassembly in human intestinal epithelial Caco-2 cells (N.
Jourdan, J. P. Brunet, C. Sapin, A. Blais, J. Cotte-Laffitte, F. Forestier, A. M.
Quero, G. Trugnan, and A. L. Servin, J. Virol. 72:7228-7236, 1998). In this
study, to determine the mechanism responsible for rotavirus-induced F-actin
alteration, we investigated the effect of infection on intracellular calcium
concentration ([Ca(2+)](i)) in Caco-2 cells, since Ca(2+) is known to be a
determinant factor for actin cytoskeleton regulation. As measured by quin2
fluorescence, viral replication induced a progressive increase in [Ca(2+)](i)
from 7 h postinfection, which was shown to be necessary and sufficient for
microvillar F-actin disassembly. During the first hours of infection, the
increase in [Ca(2+)](i) was related only to an increase in Ca(2+) permeability of
plasmalemma. At a late stage of infection, [Ca(2+)](i) elevation was due to both
extracellular Ca(2+) influx and Ca(2+) release from the intracellular organelles,
mainly the endoplasmic reticulum (ER). We noted that at this time the [Ca(2+)](i)
increase was partially related to a phospholipase C (PLC)-dependent mechanism,
which probably explains the Ca(2+) release from the ER. We also demonstrated for
the first time that viral proteins or peptides, released into culture
supernatants of rotavirus-infected Caco-2 cells, induced a transient increase in
[Ca(2+)](i) of uninfected Caco-2 cells, by a PLC-dependent efflux of Ca(2+) from
the ER and by extracellular Ca(2+) influx. These supernatants induced a Ca(2+)
dependent microvillar F-actin alteration in uninfected Caco-2 cells, thus
participating in rotavirus pathogenesis.
PMID- 10666264
TI - Characterization of the coronavirus mouse hepatitis virus strain A59 small
membrane protein E.
AB - The small envelope (E) protein has recently been shown to play an essential role
in the assembly of coronaviruses. Expression studies revealed that for formation
of the viral envelope, actually only the E protein and the membrane (M) protein
are required. Since little is known about this generally low-abundance virion
component, we have characterized the E protein of mouse hepatitis virus strain
A59 (MHV-A59), an 83-residue polypeptide. Using an antiserum to the hydrophilic
carboxy terminus of this otherwise hydrophobic protein, we found that the E
protein was synthesized in infected cells with similar kinetics as the other
viral structural proteins. The protein appeared to be quite stable both during
infection and when expressed individually using a vaccinia virus expression
system. Consistent with the lack of a predicted cleavage site, the protein was
found to become integrated in membranes without involvement of a cleaved signal
peptide, nor were any other modifications of the polypeptide observed.
Immunofluorescence analysis of cells expressing the E protein demonstrated that
the hydrophilic tail is exposed on the cytoplasmic side. Accordingly, this domain
of the protein could not be detected on the outside of virions but appeared to be
inside, where it was protected from proteolytic degradation. The results lead to
a topological model in which the polypeptide is buried within the membrane,
spanning the lipid bilayer once, possibly twice, and exposing only its carboxy
terminal domain. Finally, electron microscopic studies demonstrated that
expression of the E protein in cells induced the formation of characteristic
membrane structures also observed in MHV-A59-infected cells, apparently
consisting of masses of tubular, smooth, convoluted membranes. As judged by their
colabeling with antibodies to E and to Rab-1, a marker for the intermediate
compartment and endoplasmic reticulum, the E protein accumulates in and induces
curvature into these pre-Golgi membranes where coronaviruses have been shown
earlier to assemble by budding.
PMID- 10666265
TI - Production of recombinant snakehead rhabdovirus: the NV protein is not required
for viral replication.
AB - Snakehead rhabdovirus (SHRV) affects warm water fish in Southeast Asia and
belongs to the genus Novirhabdovirus by virtue of its nonvirion gene (NV).
Because SHRV grows best at temperatures between 28 and 31 degrees C, we were able
to use the T7 expression system to produce viable recombinant SHRV from a cloned
cDNA copy of the viral genome. Expression of a positive-strand RNA copy of the
11, 550-nucleotide SHRV genome along with the viral nucleocapsid (N),
phosphoprotein (P), and polymerase (L) proteins resulted in the generation of
infectious SHRV in cells preinfected with a vaccinia virus vector for T7
polymerase expression. Recombinant virus production was verified by detection of
a unique restriction site engineered into the SHRV genome between the NV and L
genes. Since we were now able to begin examining the function of the NV gene, we
constructed a recombinant virus containing a nonsense mutation located 22 codons
into the coding sequence of the NV protein. The NV knockout virus was produced at
a concentration as high as that of wild-type virus in cultured fish cells, and
the resulting virions appeared to be identical to the wild-type virions in
electron micrographs. These initial studies suggest that NV has no critical
function in SHRV replication in cultured fish cells.
PMID- 10666266
TI - Human T-cell leukemia virus type 1 Tax shuttles between functionally discrete
subcellular targets.
AB - Human T-cell leukemia virus type 1 (HTLV-1) Tax is a nuclear protein with
striking pleiotropic functionality. We recently demonstrated that Tax localizes
to a multicomponent nuclear speckled structure (Tax speckled structure [TSS]).
Here, we examine these structures further and identify a partial overlap of TSS
with transcription hot spots. We used a strategy of directed expression via
fusion proteins to determine if these transcription sites are the subtargets
within TSS required for Tax function. When fused to human immunodeficiency virus
type 1 (HIV-1) Tat, the resulting Tat-Tax fusion protein displayed neither a Tat
like nor a Tax-like pattern but rather was targeted specifically to the
transcription subsites. The Tat-Tax fusion was able to activate both the HIV-1
long terminal repeat (LTR) and the HTVL-1 LTR at the same level as the individual
component; thus, targeting proteins to transcription hot spots was compatible
with both Tax and Tat transcription function. In contrast, the fusion with HIV-1
Rev, Rev-Tax, resulted in a pattern of expression that was largely Rev-like
(nucleolar and cytoplasmic). The reduced localization of Rev-Tax to transcription
sites was reflected in a 10-fold drop in activation of the HTLV-1 LTR. However,
there was no loss in the ability of Tax to activate via NF-kappaB. Thus, NF
kappaB-dependent Tax function does not require targeting of Tax to these
transcription sites and suggests that activation via NF-kappaB is a cytoplasmic
function. Selective mutation of the nuclear localization signal site in the Rev
portion resulted in retargeting of Rev-Tax to TSS and subsequent restoration of
transcription function, demonstrating that inappropriate localization preceded
loss of function. Mutation of the nuclear export signal site in the Rev portion
had no effect on transcription, although the relative amount of Rev-Tax in the
cytoplasm was reduced. Finally, in explaining how Tax can occupy multiple
subcellular sites, we show that Tax shuttles from the nucleus to the cytoplasm in
a heterokaryon fusion assay. Thus, pleiotropic functionality by Tax is
regulatable via shuttling between discrete subcellular compartments.
PMID- 10666267
TI - Split-intron retroviral vectors: enhanced expression with improved safety.
AB - The inclusion of retrovirus-derived introns within retrovirus-based expression
vectors leads to a fraction of the resulting transcripts being spliced. Such
splicing has been shown to markedly improve expression (W. J. Krall et al., Gene
Ther. 3:37-48, 1996). One way to improve upon this still further might involve
the use of more efficient introns instead of those from the provirus. Currently,
however, incorporation of such introns remains self-defeating since they are
removed in the nucleus of the producer cell. In the past, elaborate ways to
overcome this problem have included the use of alphaviruses to make the vector
transcripts within the cytoplasm, thus avoiding the nuclear splicing machinery
during vector production (K. J. Li and H. Garoff, Proc. Natl. Acad. Sci. USA
95:3650-3654, 1998). We now present a novel design for the inclusion of introns
within a retroviral vector. In essence, this is achieved by exploiting the
retroviral replication process to copy not only the U3 promoter but also a
synthetic splice donor to the 5'-long-terminal-repeat position during reverse
transcription. Once copied, synthesized transcripts then contain a splice donor
at their 5' end capable of interacting with a consensus splice acceptor
engineered downstream of the packaging signal. Upon transduction, we demonstrate
these vectors to produce enhanced expression from near fully spliced (and thus
packaging signal minus) transcripts. The unique design of these high titer and
high-expression retroviral vectors may be of use in a number of gene therapy
applications.
PMID- 10666268
TI - A chimeric protein containing the N terminus of the adeno-associated virus Rep
protein recognizes its target site in an in vivo assay.
AB - The Rep78 and Rep68 proteins of adeno-associated virus (AAV) type 2 are involved
in DNA replication, regulation of gene expression, and targeting site-specific
integration. They bind to a specific Rep recognition sequence (RRS) found in both
the viral inverted terminal repeats and the AAVS1 integration locus on human
chromosome 19. Previous in vitro studies implied that an N-terminal segment of
Rep is involved in DNA recognition, while additional domains might stabilize
binding and mediate multimerization. In order to define the minimal requirements
for Rep to recognize its target site in the human genome, we developed one-hybrid
assays in which DNA-protein interactions are detected in vivo. Chimeric proteins
consisting of the N terminus of Rep fused to different oligomerization motifs and
a transcriptional activation domain were analyzed for oligomerization, DNA
binding, and activation of reporter gene expression. Expression of reporter genes
was driven from RRS motifs cloned upstream of minimal promoters and examined in
mammalian cells from transfected plasmids and in Saccharomyces cerevisiae from a
reporter cassette integrated into the yeast genome. Our results show for the
first time that chimeric proteins containing the amino-terminal 244 residues of
Rep are able to target the RRS in vitro and in vivo when incorporated into
artificial multimers. These studies suggest that chimeric proteins may be used to
harness the unique targeting feature of AAV for gene therapy applications.
PMID- 10666269
TI - A stable HeLa cell line that inducibly expresses poliovirus 2A(pro): effects on
cellular and viral gene expression.
AB - A HeLa cell clone (2A7d) that inducibly expresses the gene for poliovirus
protease 2A (2A(pro)) under the control of tetracycline has been obtained.
Synthesis of 2A(pro) induces severe morphological changes in 2A7d cells. One day
after tetracycline removal, cells round up and a few hours later die. Poliovirus
2A(pro) cleaves both forms of initiation factor eIF4G, causing extensive
inhibition of capped-mRNA translation a few hours after protease induction.
Methoxysuccinyl-Ala-Ala-Pro-Val-chloromethylketone, a selective inhibitor of
2A(pro), prevents both eIF4G cleavage and inhibition of translation but not
cellular death. Expression of 2A(pro) still allows both the replication of
poliovirus and the translation of mRNAs containing a picornavirus leader
sequence, while vaccinia virus replication is drastically inhibited. Translation
of transfected capped mRNA is blocked in 2A7d-On cells, while luciferase
synthesis from a mRNA bearing a picornavirus internal ribosome entry site (IRES)
sequence is enhanced by the presence of 2A(pro). Moreover, synthesis of 2A(pro)
in 2A7d cells complements the translational defect of a poliovirus 2A(pro)
defective variant. These results show that poliovirus 2A(pro) expression mimics
some phenotypical characteristics of poliovirus-infected cells, such as cell
rounding, inhibition of protein synthesis and enhancement of IRES-driven
translation. This cell line constitutes a useful tool to further analyze 2A(pro)
functions, to complement poliovirus 2A(pro) mutants, and to test antiviral
compounds.
PMID- 10666270
TI - Clustered charge-to-alanine mutagenesis of the vaccinia virus H5 gene: isolation
of a dominant, temperature-sensitive mutant with a profound defect in
morphogenesis.
AB - The vaccinia virus H5 gene encodes a 22.3-kDa phosphoprotein that is expressed
during both the early and late phases of viral gene expression. It is a major
component of virosomes and has been implicated in viral transcription and, as a
substrate of the B1 kinase, may participate in genome replication. To enable a
genetic analysis of the role of H5 during the viral life cycle, we used clustered
charge-to-alanine mutagenesis in an attempt to create a temperature-sensitive
(ts) virus with a lesion in the H5 gene. Five mutant viruses were isolated, with
one of them, tsH5-4, having a strong ts phenotype as assayed by plaque formation
and measurements of 24-h viral yield. Surprisingly, no defects in genome
replication or viral gene expression were detected at the nonpermissive
temperature. By electron microscopy, we observed a profound defect in the early
stages of virion morphogenesis, with arrest occurring prior to the formation of
crescent membranes or immature particles. Nonfunctional, "curdled" virosomes were
detected in tsH5-4 infections at the nonpermissive temperature. These structures
appeared to revert to functional virosomes after a temperature shift to
permissive conditions. We suggest an essential role for H5 in normal virosome
formation and the initiation of virion morphogenesis. By constructing recombinant
genomes containing two H5 alleles, wild type and H5-4, we determined that H5-4
exerted a dominant phenotype. tsH5-4 is the first example of a dominant ts mutant
isolated and characterized in vaccinia virus.
PMID- 10666271
TI - The decreased replicative capacity of simian immunodeficiency virus
SIVmac239Delta(nef) is manifest in cultures of immature dendritic cellsand T
cells.
AB - Transmission of simian immunodeficiency virus SIVmac239Delta(nef) (Delta(nef)) to
macaques results in attenuated replication of the virus in most animals and
ultimately induces protection against challenge with some pathogenic, wild-type
SIV strains. It has been difficult, however, to identify a culture system in
which the replication of Delta(nef) is severely reduced relative to that of the
wild type. We have utilized a primary culture system consisting of blood-derived
dendritic cells (DCs) and autologous T cells. When the DCs were fully
differentiated or mature, the DC-CD4(+) T-cell mixtures supported replication of
both the parental SIV strain, 239 (the wild type), and its mutant with nef
deleted (Delta(nef)), irrespective of virus dose and the cell type introducing
the virus to the coculture. In contrast, when immature DCs were exposed to
Delta(nef) and cocultured with T cells, virus replication was significantly lower
than that of the wild type. Activation of the cultures with a superantigen
allowed both Delta(nef) and the wild type to replicate comparably in immature DC
T-cell cultures. Immature DCs, which, it has been hypothesized, capture and
transmit SIV in vivo, are deficient in supporting replication of Delta(nef) in
vitro and may contribute to the reduced pathogenicity of Delta(nef) in vivo.
PMID- 10666272
TI - Herpes simplex virus type 1-specific cytotoxic T-lymphocyte arming occurs within
lymph nodes draining the site of cutaneous infection.
AB - Various studies have shown that major histocompatibility complex class I
restricted cytotoxic T lymphocytes (CTL) can be isolated from lymph nodes
draining sites of cutaneous infection with herpes simplex virus type 1 (HSV-1).
Invariably, detection of this cytolytic activity appeared to require some level
of in vitro culture of the isolated lymph node cells, usually for 3 days, in the
absence of exogenous viral antigen. This in vitro "resting" period was thought to
represent the phase during which committed CD8(+) T cells become "armed" killers
after leaving the lymph nodes and prior to their entry into infected tissue as
effector CTL. In this study we reexamined the issue of CTL appearance in the HSV
1 immune response and found that cytolytic activity can be isolated directly from
draining lymph nodes, although at levels considerably below those found after in
vitro culture. By using T-cell receptor elements that represent effective markers
for class I-restricted T cells specific for an immunodominant glycoprotein B (gB)
determinant from HSV-1, we show that the increase in cytotoxicity apparent after
in vitro culture closely mirrors the expansion of gB-specific CTL during the same
period. Taken together, our results suggest that HSV-1-specific CTL priming does
not appear to require any level of cytolytic machinery arming outside the lymph
node compartment despite the absence of any detectable infection within that
site.
PMID- 10666273
TI - Humoral immunity to adeno-associated virus type 2 vectors following
administration to murine and nonhuman primate muscle.
AB - Adeno-associated virus (AAV) is being developed as a vector capable of conferring
long-term gene expression, which is useful in the treatment of chronic diseases.
In most therapeutic applications, it is necessary to readminister the vector.
This study characterizes the humoral immune response to AAV capsid proteins
following intramuscular injection and its impact on vector readministration.
Studies of mice and rhesus monkeys demonstrated the formation of neutralizing
antibodies to AAV capsid proteins that persisted for over 1 year and then
diminished, but this did not prevent the efficacy of vector readministration.
More-detailed studies strongly suggested that the B-cell response was T cell
dependent. This was further evaluated with a blocking antibody to human CD4,
primatized for clinical trials, in a biologically compatible mouse in which the
endogenous murine CD4 gene was functionally replaced with the human counterpart.
Transient pharmacologic inhibition of CD4 T cells with CD4 antibody prevented an
antivector response long after the effects of the CD4 antibody diminished;
readministration of vector without diminution of gene expression was possible.
Our studies suggest that truly durable transgene expression (i.e., prolonged
genetic engraftment together with vector readministration) is possible with AAV
in skeletal muscle, although it will be necessary to transiently inhibit CD4 T
cell function to avoid the activation of memory B cells.
PMID- 10666274
TI - Role of maternal antibody in natural infection of Peromyscus maniculatus with Sin
Nombre virus.
AB - Data from naturally infected deer mice (Peromyscus maniculatus) were used to
investigate vertical transmission of Sin Nombre virus (SNV) and SNV-specific
antibody. The antibody prevalence in juvenile mice (14 g or less) was inversely
proportional to the mass of the animal, with juvenile deer mice weighing less
than 11 g most likely to be antibody positive (26.9%) and juvenile mice weighing
between 13 and 14 g least likely to be antibody positive (12.9%). Although a
significant sex bias in seropositivity was detected in adult deer mice, no
significant sex bias in seropositivity was detected in juvenile animals. Ten
juvenile deer mice were identified that had initially tested positive for SNV
specific immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA) but
had subsequently tested negative when recaptured as adults. SNV RNA was detected
by reverse transcriptase PCR (RT-PCR) in the blood of ELISA-positive adult deer
mice but not in the blood of ELISA-positive juveniles. One of the juvenile mice
initially tested negative for SNV RNA but later tested positive when recaptured
as an ELISA-positive adult. The RT-PCR results for that individual correlated
with the disappearance and then reappearance of SNV-specific IgG, indicating that
the presence of SNV RNA at later time points was due to infection with SNV via
horizontal transmission. SNV-specific antibody present in both ELISA-positive
juvenile and adult mice was capable of neutralizing SNV. Additionally, our data
indicate that SNV is not transmitted vertically.
PMID- 10666275
TI - The in vitro-synthesized RNA from a cDNA clone of hepatitis E virus is
infectious.
AB - Hepatitis E virus (HEV) is an important etiological agent of epidemic and
sporadic hepatitis, which is endemic to the Indian subcontinent and prevalent in
most of the developing parts of the world. The infection is often associated with
acute liver failure and high mortality, particularly in pregnant women. In order
to develop methods of intervention, it is essential to understand the biology of
the virus. This is particularly important as no reliable in vitro culture system
is available. We have constructed a cDNA clone encompassing the complete HEV
genome from independently characterized subgenomic fragments of an Indian
epidemic isolate. Transfection studies were carried out with HepG2 cells using in
vitro-transcribed RNA from this full-length HEV cDNA clone. The presence of
negative-sense RNA, indicative of viral replication, was demonstrated in the
transfected cells by strand-specific reverse transcription-PCR and slot blot
hybridization. The viral proteins pORF2 and pORF3 and processed components of the
pORF1 polyprotein (putative methyltransferase, helicase, and RNA-dependent RNA
polymerase) were identified in the transfected cells by metabolic pulse-labeling
with [(35)S]methionine-cysteine, followed by immunoprecipitation with respective
antibodies. The expression of viral proteins in the transfected cells was also
demonstrated by immunofluorescence microscopy. Viral replication was detected in
the transfected cells up to 33 days posttransfection (six passages). The culture
supernatant from the transfected cells was able to produce HEV infection in a
rhesus monkey (Macaca mulatta) following intravenous injection, indicating the
generation of viable HEV particles following transfection of cells with in vitro
synthesized genomic RNA. This transient cell culture model using in vitro
transcribed RNA should facilitate our understanding of HEV biology.
PMID- 10666276
TI - Disulfide bonds and membrane topology of the vaccinia virus A17L envelope
protein.
AB - The envelope protein encoded by the vaccinia virus A17L open reading frame is
essential for virion assembly. Our mutagenesis studies indicated that cysteines
101 and 121 form an intramolecular disulfide bond and that cysteine 178 forms an
intermolecular disulfide linking two A17L molecules. This arrangement of
disulfide bonds has important implications for the topology of the A17L protein
and supports a two-transmembrane model in which cysteines 101 and 121 are
intraluminal and cysteine 178 is cytoplasmic. The structure of the A17L protein,
however, was not dependent on these disulfide bonds, as a recombinant vaccinia
virus with all three cysteine codons mutated to serines retained infectivity.
PMID- 10666277
TI - Elevated serum transforming growth factor beta1 levels in Epstein-Barr virus
associated diseases and their correlation with virus-specific immunoglobulin A
(IgA) and IgM.
AB - Transforming growth factor beta (TGF-beta) is an immunosuppressive cytokine which
can induce immunoglobulin A (IgA) switch and Epstein-Barr virus (EBV) replication
in latently infected cells. Here we report elevated serum levels of TGF-beta in
various EBV-associated diseases correlating positively with EBV-specific IgA
titers and negatively with IgM titers, suggesting a role for this cytokine in the
pathogenesis of these diseases.
PMID- 10666278
TI - Contributions of Fas-Fas ligand interactions to the pathogenesis of mouse
hepatitis virus in the central nervous system.
AB - The pathogenesis of the neurotropic strain of mouse hepatitis virus in Fas
deficient mice suggested that Fas-mediated cytotoxicity may be required during
viral clearance after the loss of perforin-mediated cytotoxicity. The absence of
both Fas- and perforin-mediated cytolysis resulted in an uncontrolled infection,
suggesting a redundancy of cytolytic pathways to control virus replication.
PMID- 10666279
TI - Epstein-Barr virus entry utilizing HLA-DP or HLA-DQ as a coreceptor.
AB - Epstein-Barr virus (EBV) glycoprotein gp350/gp220 association with cellular CD21
facilitates virion attachment to B lymphocytes. Membrane fusion requires the
additional interaction between virion gp42 and cellular HLA-DR. This binding is
thought to catalyze membrane fusion through a further association with the gp85
gp25 (gH-gL) complex. Cell lines expressing CD21 but lacking expression of HLA
class II molecules are resistant to infection by a recombinant EBV expressing
enhanced green fluorescent protein. Surface expression of HLA-DR, HLA-DP, or HLA
DQ confers susceptibility to EBV infection on resistant cells that express CD21.
Therefore, HLA-DP or HLA-DQ can substitute for HLA-DR and serve as a coreceptor
in EBV entry.
PMID- 10666280
TI - Hepadnavirus envelope topology: insertion of a loop region in the membrane and
role of S in L protein translocation.
AB - A unique feature of the large hepadnavirus envelope protein (L) is its mixed
transmembrane topology, resulting from partial posttranslational translocation of
the pre-S domain. Using protease protection analysis, we demonstrate for duck
hepatitis B virus an essential role for the small envelope protein (S) in this
process, providing the first experimental evidence for an S translocation
channel. Further analysis revealed that the presumed cytoplasmic loop between TM1
and TM2 in the C-terminal S domain is membrane embedded and protrudes to the
particle surface. These data suggest that some L molecules form a highly folded,
potentially spring-loaded topology with five membrane-spanning regions and a
membrane-traversing pre-S chain.
PMID- 10666281
TI - Adeno-associated virus major Rep78 protein disrupts binding of TATA-binding
protein to the p97 promoter of human papillomavirus type 16.
AB - Adeno-associated virus type 2 (AAV) is known to inhibit the promoter activities
of several oncogenes and viral genes, including the human papillomavirus type 16
(HPV-16) E6 and E7 transforming genes. However, the target elements of AAV on the
long control region (LCR) upstream of E6 and E7 oncogenes are elusive. A
chloramphenicol acetyltransferase assay was performed to study the effect of AAV
on the transcription activity of the HPV-16 LCR in SiHa (HPV-positive) and C-33A
(HPV-negative) cells. The results reveal that (i) AAV inhibited HPV-16 LCR
activity in a dose-dependent manner, (ii) AAV-mediated inhibition did not require
the HPV gene products, and (iii) the AAV replication gene product Rep78 was
involved in the inhibition. Deletion mutation analyses of the HPV-16 LCR showed
that regulatory elements outside the core promoter region of the LCR may not be
direct targets of AAV-mediated inhibition. Further study with the electrophoretic
mobility shift assay demonstrated that Rep78 interfered with the binding of TATA
binding protein (TBP) to the TATA box of the p97 core promoter more significantly
than it disrupted the preformed TBP-TATA complex. These data thus suggest that
Rep78 may inhibit transcription initiation of the HPV-16 LCR by disrupting the
interaction between TBP and the TATA box of the p97 core promoter.
PMID- 10666282
TI - The c-myc locus is a common integration site in type B retrovirus-induced T-cell
lymphomas.
AB - Type B leukemogenic virus (TBLV) induces rapidly appearing T-cell leukemias. TBLV
insertions near the c-myc gene were detectable in 2 of 30 tumors tested, whereas
80% of the tumors showed c-myc overexpression. TBLV insertions on chromosome 15
(including a newly identified locus, Pad7) may cause c-myc overexpression by cis
acting effects at a distance.
PMID- 10666283
TI - Therapeutic effect of anti-macrophage inflammatory protein 2 antibody on
influenza virus-induced pneumonia in mice.
AB - We investigated the effect of anti-macrophage inflammatory protein 2
immunoglobulin G (aMIP-2 IgG) on the progression of influenza virus-induced
pneumonia in mice. When mice were infected with a mouse lung-adapted strain of
influenza A/PR/8/34 virus by intranasal inoculation, neutrophil counts in the
bronchoalveolar lavage fluid (BALF) increased in parallel with the kinetics of
MIP-2 production, which peaked 2 days after infection. After intracutaneous
injection of a dose of 10 or 100 microg of aMIP-2 IgG once a day on days 0 and 1,
neutrophil counts in BALF on day 2 were reduced to 49 or 37%, respectively, of
the value in the control infected mice administered anti-protein A IgG. The
antibody administration also improved lung pathology without affecting virus
replication. Furthermore, by prolonged administration with a higher or lower dose
for up to 5 days, body weight loss became slower and finally 40% of mice in both
treatment groups survived potentially lethal pneumonia. These findings suggest
that MIP-2-mediated neutrophil infiltration during the early phase of infection
might play an important role in lung pathology. Thus, MIP-2 was considered to be
a novel target for intervention therapy in potentially lethal influenza virus
pneumonia in mice.
PMID- 10666284
TI - Sendai virus blocks alpha interferon signaling to signal transducers and
activators of transcription.
AB - We demonstrate here that Sendai virus (SeV) blocks alpha interferon (IFN-alpha)
signaling to signal transducers and activators of transcription (STATs) in HeLa
cells. IFN-alpha-stimulated tyrosine phosphorylation of STATs and subsequent
formation of the IFN-stimulated gene factor 3 transcription complex were
inhibited in SeV-infected cells, resulting in inefficient induction of IFN
stimulated gene products. None of the components of the signaling pathway-type I
IFN receptor subunits Jak1, Tyk2, Stat1, Stat2, and p48-was degraded. Moreover,
tyrosine phosphorylation of Jak1 in response to IFN-alpha was unaffected at the
early phase of infection, suggesting that oligomerization of the receptor
subunits proceeded normally. In contrast to Jak1, IFN-alpha-stimulated tyrosine
phosphorylation of Tyk2 was partially inhibited. Therefore, this partial
inhibition of activation of Tyk2 probably contributes to the subsequent failure
in the activation of STATs.
PMID- 10666285
TI - Pseudotyping of glycoprotein D-deficient herpes simplex virus type 1 with
vesicular stomatitis virus glycoprotein G enables mutant virus attachment and
entry.
AB - The use of herpes simplex virus (HSV) vectors for in vivo gene therapy will
require the targeting of vector infection to specific cell types in certain in
vivo applications. Because HSV glycoprotein D (gD) imparts a broad host range for
viral infection through recognition of ubiquitous host cell receptors, vector
targeting will require the manipulation of gD to provide new cell recognition
specificities in a manner designed to preserve gD's essential role in virus
entry. In this study, we have determined whether an entry-incompetent HSV mutant
with deletions of all Us glycoproteins, including gD, can be complemented by a
foreign attachment/entry protein with a different receptor-binding specificity,
the vesicular stomatitis virus glycoprotein G (VSV-G). The results showed that
transiently expressed VSV-G was incorporated into gD-deficient HSV envelopes and
that the resulting pseudotyped virus formed plaques on gD-expressing VD60 cells,
albeit at a 50-fold-reduced level compared to that of wild-type gD. This
reduction may be related to differences in the entry pathways used by VSV and HSV
or to the observed lower rate of incorporation of VSV-G into virus envelopes than
that of gD. The rate of VSV-G incorporation was greatly improved by using
recombinant molecules in which the transmembrane domain of HSV glycoprotein B or
D was substituted for that of VSV-G, but these recombinant molecules failed to
promote virus entry. These results show that foreign glycoproteins can be
incorporated into the HSV envelope during replication and that gD can be
dispensed with on the condition that a suitable attachment/entry function is
provided.
PMID- 10666286
TI - Effect of maternal nutrient restriction in early gestation on responses of the
hypothalamic-pituitary-adrenal axis to acute isocapnic hypoxaemia in late
gestation fetal sheep.
AB - Epidemiological and experimental evidence suggests that maternal undernutrition
during pregnancy may alter development of fetal organ systems. We have
demonstrated previously that fetal hypothalamic-pituitary-adrenal (HPA) axis
responses to exogenous corticotropin-releasing hormone (CRH) + arginine
vasopressin (AVP), or adrenocorticotrophin hormone (ACTH), are reduced in fetuses
of mildly undernourished ewes. To examine these effects further we tested HPA
axis responses to acute isocapnic hypoxaemia in fetal sheep at 114-129 days
gestation (dGA), following 15% reduction in maternal nutritional intake between 0
and 70 dGA. Fetuses from control (C) and nutrient-restricted (R) ewes were
chronically catheterised and plasma ACTH and cortisol responses were determined
at 114-115, 120-123 and 126-129 dGA during hypoxaemia (1 h) induced by lowering
the maternal inspired O2 fraction (FI,O2). Basal plasma cortisol concentrations
and HPA axis responses at 114-115 and 120-123 dGA did not differ between C and R
fetuses. At 126-129 dGA, both plasma ACTH (P < 0.01) and cortisol (P < 0.05)
responses were smaller in R fetuses compared to C fetuses. Fetal blood gas
status, fetal body weight, body proportions and organ weights did not differ
between the groups. We conclude that mild maternal undernutrition alters
development of the fetal HPA axis producing a reduction in pituitary and adrenal
responsiveness to endogenous stimuli.
PMID- 10666287
TI - Management of peripheral arterial disease (PAD). TASC Working Group.
TransAtlantic Inter-Society Consensus (TASC).
PMID- 10666288
TI - The enzymatic formation of novel bile acid primary amides.
AB - Bifunctional peptidylglycine alpha-amidating monooxygenase (PAM) catalyzes the
copper-, ascorbate-, and O(2)-dependent cleavage of C-terminal glycine-extended
peptides and N-acylglycines to the corresponding amides and glyoxylate. The alpha
amidated peptides and the long-chain acylamides are hormones in humans and other
mammals. Bile acid glycine conjugates are also substrates for PAM leading to the
formation of bile acid amides. The (V(MAX)/K(m))(app) values for the bile acid
glycine conjugates are comparable to other known PAM substrates. The highest
(V(MAX)/K(m))(app) value, 3.1 +/- 0.12 x 10(5) M(-1) s(-1) for 3
sulfolithocholylglycine, is 6.7-fold higher than that for d-Tyr-Val-Gly, a
representative peptide substrate. The time course for O(2) consumption and
glyoxylate production indicates that bile acid glycine conjugate amidation is a
two-step reaction. The bile acid glycine conjugate is first converted to an N
bile acyl-alpha-hydroxyglycine intermediate which is ultimately dealkylated to
the bile acid amide and glyoxylate. The enzymatically produced bile acid amides
and the carbinolamide intermediates were characterized by mass spectrometry and
two-dimensional (1)H-(13)C heteronuclear multiple quantum coherence NMR.
PMID- 10666289
TI - Measurement of the main photooxidation products of 2'-deoxyguanosine using
chromatographic methods coupled to mass spectrometry.
AB - Analytical methods were developed for the measurement of the main photooxidation
products of 2'-deoxyguanosine (dGuo), arising from either the type I (electron
transfer) or the type II (singlet oxygen) photosensitization mechanism. Oxidation
of dGuo by a type I mechanism leads to the predominant formation of 2, 2-diamino
5-[2-deoxy-beta-d-erythro-pentofuranosyl)amino]-5(2H)-oxazo lone. On the other
hand, the two 4R and 4S diastereomers of 4-hydroxy-8-oxo-4,8-dihydro-2'
deoxyguanosine are the main singlet oxygen-mediated dGuo oxidation products. The
modified nucleosides were measured by either gas chromatography coupled to mass
spectrometry after silylation of the sample or by high-performance liquid
chromatography associated to tandem mass spectrometry. In order to improve the
accuracy of the assays, isotopically labeled internal standards were synthesized
for an isotope dilution mass spectrometry quantitation. The methods were
successfully applied to the measurement of methylene blue- and riboflavin
mediated 2'-deoxyguanosine photooxidation reactions. The advantages of the two
above-mentioned methods are discussed on the basis of comparative sensitivity and
accuracy.
PMID- 10666290
TI - Cytochromes P450 2C1/2 and P450 2E1 are retained in the endoplasmic reticulum
membrane by different mechanisms.
AB - Cytochrome P450 (P450) 2C1/2 contains redundant endoplasmic reticulum (ER)
retention signals and is excluded from the recycling pathway. Other P450s, such
as P450 2E1, have been detected in the plasma membrane and Golgi apparatus. To
examine whether the mechanisms of ER retention might differ for P450 2C1/2 and
P450 2E1, chimeras of green flourescent protein and the full-length proteins, N
terminal signal/anchor sequences, or the cytoplasmic catalytic domains from these
proteins have been expressed in COS1 cells. Chimeras with either the N-terminal
signal/anchor sequence or the cytoplasmic domain of P450 2C1/2 were retained in
the ER and the distribution was not altered by treatment with nocodazole. A
chimera with full-length P450 2E1 was located in the ER, but in contrast to P450
2C1/2, treatment with nocodazole resulted in redistribution to a vesicular
pattern, which suggested that this protein was retained in the ER by a retrieval
mechanism. In support of this possibility, the P450 2E1 chimera, but not the P450
2C1/2 chimera, was included in transport vesicles generated in an in vitro
budding assay. A chimera with only the N-terminal signal/anchor sequence of P450
2E1 fused to green fluorescent protein was located in the ER and nocodazole
treatment altered its distribution, whereas a chimera with only the cytoplasmic
domain of P450 2E1 was not efficiently retained in the ER and accumulated
primarily in the Golgi region. These results demonstrate that the mechanisms for
retention in the ER of two closely related members of the P450 superfamily are
different and that the N-terminal signal/anchor sequence contains the dominant
retention signal.
PMID- 10666291
TI - Copper-dependent formation of disulfide-linked dimer of S100B protein.
AB - Previous cell biological studies demonstrated that S100B protein enhances neurite
extension of cortical neurons and stimulates proliferation of glial cells.
Although these activities of the protein are ascribed to its disulfide-linked
dimeric form, there have been no indications as to how the dimer is formed in
vivo. We have found by an in vitro study that it is produced by copper-dependent
oxidation of noncovalent S100B dimer. The disulfide-linked dimer markedly
stimulated nitric oxide production in a microglial cell line, BV2. Interestingly,
the disulfide-linked dimer formation was found to be prevented by ascorbic acid.
The copper-dependent formation of the dimer may not happen in vivo under normal
conditions; however, under pathological conditions where copper is likely to be
released from tissues and catalyze autoxidation of ascorbic acid, the dimer
formation may proceed, resulting in the stimulated production of nitric oxide
that would induce toxic signaling pathways.
PMID- 10666292
TI - Ebselen induces apoptosis in HepG(2) cells through rapid depletion of
intracellular thiols.
AB - Ebselen, 2-phenyl-1,2-benzisoselenazol-3(2H)-one, is a synthetic seleno-organic
compound with antioxidant capability. In the present study, we systematically
examined the ability of ebselen to induce apoptosis in a human hepatoma cell
line, HepG(2). Ebselen-induced apoptosis was evaluated by (i) TdT-mediated dUTP
nick end labeling assay; (ii) analysis of sub-G1 cells; (iii) cell morphology,
including cell size and granularity examination; and (iv) DNA gel
electrophoresis. The results showed that ebselen was able to induce typical
apoptosis in HepG(2) cells in a dose- and time-dependent manner. In order to
explore the possible mechanisms involved in ebselen-induced apoptosis, the effect
of ebselen on intracellular thiol concentrations including reduced glutathione
(GSH) and protein thiols and the effect of N-acetylcysteine (NAC) and buthionine
sulfoximine (BSO) pretreatment on ebselen-induced apoptosis were investigated. It
was found that (i) ebselen rapidly depleted intracellular GSH and protein thiols,
moreover, the depletion preceded the occurrence of apoptosis; (ii) NAC, a
precursor of intracellular GSH synthesis, significantly alleviated ebselen
induced apoptosis; and (iii) BSO, a specific inhibitor of intracellular GSH
synthesis, augmented ebselen-induced apoptosis significantly. Taken together, the
present study demonstrates that ebselen is able to induce apoptosis in HepG(2)
cells, most probably through rapid depletion of intracellular thiols.
PMID- 10666293
TI - Differential gene expression in the activation and maturation of human monocytes.
AB - Differential-display or RNA fingerprint was applied to identify genes
differentially expressed in monocyte maturation induced by an immunomodulating
peptide on human peripheral blood mononuclear cells. Two unknown sequences (06c22
and 06c71) and p21 protein (cyclin dependent kinase inhibitor) were repressed,
and three genes activated: Cathepsin D, DRP2 (dihydropirimidinase related protein
2), and gp91phox (91-kDa subunit of citochrome b(558)). Phenotype of evolving
monocytes was analyzed by flow cytometry and mRNA level of identified genes
determined by reverse transcription-PCR. The expression pattern of identified
genes seemed to correlate with different monocyte subsets, monocyte-derived
cells, and expected functional changes. After peptide addition, immature
monocytes were initially activated, increasing the expression of CD25, CD69, and
HLA-DR markers. This was accompanied by repression of p21 and the two unknown
sequences, along with the simultaneous activation of Cathepsin D and DRP2. Later,
the differentiation marker CD16 rose, and gp91phox gene expression activated.
Further maturation led certain monocytes to express marker CD23 and gp91phox
expression to reach a maximum, while Cathepsin D and DRP2 dropped to
preactivation levels. Results reflect part of the evolution of immature monocytes
toward macrophages and monocyte-derived dendritic cell precursors.
PMID- 10666294
TI - Effects of histone deacetylase inhibitors on the Ah receptor gene promoter.
AB - The aromatic hydrocarbon receptor (AhR) is a ligand-dependent basic helix-loop
helix-PAS-containing transcription factor which is activated by chemicals such as
2,3,7,8-tetrachlorodibenzo-p-dioxin. Constitutive expression of the AhR gene
occurs in a tissue- and developmentally specific manner and appears to be altered
by chemicals which affect histone deacetylase (HDAC) activity in cells in
culture. Here we have directly characterized the effects of two HDAC inhibitors,
n-butyrate and trichostatin A, on the promoter activity of the murine AhR gene.
HDAC inhibitors increased the constitutive activity of the AhR gene promoter in a
luciferase reporter construct by five- to sevenfold in a dose- and time-dependent
manner in several cell lines and was correlated with an increase in endogenous
AhR activity in an AhR-deficient cell line. Deletion analysis of the upstream
region of the AhR gene localized the HDAC inhibitor effect to a 167-bp region
encompassing -77 to +90 of the AhR gene promoter. Cotransfection of an AhR
promoter-luciferase reporter plasmid with a vector expressing the E1A(12s)
oncoprotein, a negative regulator of p300, a protein with histone acetylase
activity, decreased AhR promoter activity fivefold. Overall, our results support
a role for histone acetylation in the transcriptional activity of the AhR gene
promoter.
PMID- 10666295
TI - The role of microtubules in the regulation of proteoglycan synthesis in
chondrocytes under hydrostatic pressure.
AB - Chondrocytes of the articular cartilage sense mechanical factors associated with
joint loading, such as hydrostatic pressure, and maintain the homeostasis of the
extracellular matrix by regulating the metabolism of proteoglycans (PGs) and
collagens. Intermittent hydrostatic pressure stimulates, while continuous high
hydrostatic pressure inhibits, the biosynthesis of PGs. High continuous
hydrostatic pressure also changes the structure of cytoskeleton and Golgi complex
in cultured chondrocytes. Using microtubule (MT)-affecting drugs nocodazole and
taxol as tools we examined whether MTs are involved in the regulation of PG
synthesis in pressurized primary chondrocyte monolayer cultures. Disruption of
the microtubular array by nocodazole inhibited [(35)S]sulfate incorporation by 39
48%, while MT stabilization by taxol caused maximally a 17% inhibition.
Continuous hydrostatic pressure further decreased the synthesis by 34-42% in
nocodazole-treated cultures. This suggests that high pressure exerts its
inhibitory effect through mechanisms independent of MTs. On the other hand,
nocodazole and taxol both prevented the stimulation of PG synthesis by cyclic 0.
5 Hz, 5 MPa hydrostatic pressure. The drugs did not affect the structural and
functional properties of the PGs, and none of the treatments significantly
affected cell viability, as indicated by the high level of PG synthesis 24-48 h
after the release of drugs and/or high hydrostatic pressure. Our data on two
dimensional chondrocyte cultures indicate that inhibition of PG synthesis by
continuous high hydrostatic pressure does not interfere with the MT-dependent
vesicle traffic, while the stimulation of synthesis by cyclic pressure does not
occur if the dynamic nature of MTs is disturbed by nocodazole. Similar phenomena
may operate in cartilage matrix embedded chondrocytes.
PMID- 10666296
TI - Isolation and characterization of a novel 530-kDa protein complex (PC530) capable
of associating with the 20S proteasome from starfish oocytes.
AB - A novel protein complex called PC530 was purified concomitantly with proteasomes
from oocytes of the starfish, Asterina pectinifera, by chromatography with DEAE
cellulose, phosphocellulose, Mono Q, and Superose 6 columns. The molecular mass
of this complex was estimated to be 530 kDa by Ferguson plot analysis and about
500 kDa by Superose 6 gel filtration. Since the 1500-kDa proteasome fractions
contain the PC530 subunits as well as the 20S proteasomal subunits, and also
since the purified PC530 and the 20S proteasome were cross-linked with a
bifunctional cross-linking reagent, it is thought that PC530 is able to associate
with the 20S proteasome. The PC530 comprises six main subunits with molecular
masses of 105, 70, 50, 34, 30, and 23 kDa. The 70-kDa subunit showed a sequence
similarity to the S3/p58/Sun2/Rpn3p subunit of the 26S proteasome, whereas the
other subunits showed little or no appreciable similarity to the mammalian and
yeast regulatory subunits. These results indicate that starfish oocytes contain a
novel 530-kDa protein complex capable of associating with the 20S proteasome,
which is distinctly different from PA700 or the 19S regulatory complex in
molecular size and subunit composition.
PMID- 10666297
TI - Purification and characterization of NAD-dependent morphine 6-dehydrogenase from
hamster liver cytosol, a new member of the aldo-keto reductase superfamily.
AB - Morphine 6-dehydrogenase, which catalyzes the dehydrogenation of morphine to
morphinone, was purified 815-fold to a homogeneous protein from the soluble
fraction of hamster liver with a yield of 15%. The enzyme was a monomeric protein
with a molecular weight of 38 kDa and an isoelectric point of 5.6. Although both
NAD and NADP served as cofactors, the enzyme activity with NADP was less than 5%
that found with NAD at pH 7.4. With NAD, the enzyme gave the maximal activity at
pH 9.3, and the K(m) and V(max) values toward morphine were 1.0 mM and 0.43
unit/mg protein, respectively. Among morphine congeners, normorphine exhibited
higher activity than morphine, but codeine and ethylmorphine were poor
substrates, and dihydromorphine and dihydrocodeine showed no detectable activity.
The enzyme also exhibited significant activity for a variety of cyclic and
alicyclic alcohols. In addition to xenobiotics, the enzyme catalyzed the
dehydrogenation of 17beta-hydroxysteroids with much higher affinities than
morphine. In the reverse reaction, the enzyme exhibited high activity for o
quinones, but morphinone, naloxone, and aromatic aldehydes and ketones were
reduced at slow rates. Sulfhydryl reagents and ketamine strongly inhibited the
enzyme, whereas pyrazole, barbital, and indomethacin had little effect on enzyme
activity. 17beta-Hydroxysteroids inhibited the enzyme in a competitive manner
against morphine. A total of 302 amino acid residues, which comprised
approximately 94% of whole protein, were identified by sequencing of the peptides
obtained by proteolytic digestion. This amino acid sequence of the enzyme showed
significant homology to members of the aldo-keto reductase (AKR) superfamily and
shared 63-64% identity with members of the AKR1C subfamily. These findings
indicate that the enzyme is a new member of the AKR superfamily that is involved
in steroid metabolism as 17beta-hydroxysteroid dehydrogenase as well as
xenobiotic metabolism.
PMID- 10666298
TI - Regulation in metabolic systems under homeostatic flux control.
AB - The general properties of metabolic systems under homeostatic flux control are
analyzed. It is shown that the main characteristic point for an enzyme in such a
system is a sharp transition from limitation outside the system to limitation by
some enzyme inside the system. A method for the quantitative treatment of the
experimental dependence of metabolic flux on enzyme content is presented. The
conception of "nonlimiting," "near-limiting," and "limiting" enzymes is developed
for these systems. It is pointed out that reactions close to a thermodynamic
equilibrium under normal conditions can considerably limit the homeostatic
fluxes. The rules for regulation of fluxes in such systems are illustrated by the
data obtained for transgenic plants with reduced activities of some Calvin-cycle
enzymes and further examples. A comparison is made between the developed
quantitative description of metabolic fluxes under homeostatic flux control and
the methods of metabolic control analysis.
PMID- 10666299
TI - Distribution of proteasomes and of the five proteolytic activities in rat
tissues.
AB - Five peptidase activities (ChT-L, T-L, PGPH, BrAAP, and SNAAP) of the proteasome,
and its caseinolytic activity, were measured in crude extracts of 10 rat tissues
under experimental conditions simulating those found in vivo, thereby eliminating
the alterations observed with the purified enzyme. The total and individual
peptidase activities varied considerably from one tissue to another, whereas the
proteolytic activity measured with [(14)C]methylcasein varied no more than
twofold. The tissue-specific variations in individual peptidase activities may
reflect tissue-specific differences in proteasome subunit composition, or the
presence of regulators. Immunological assay using an antibody directed against
the iota (alpha1) subunit showed that there was no correlation between protein
abundance and peptidase activity. The results also show that the different
peptidase activities are not representative of proteasome distribution in the
different tissues.
PMID- 10666300
TI - Phospholipase A(2) is involved in thapsigargin-induced sodium influx in human
lymphocytes.
AB - Previously, we reported that emptying of intracellular Ca(2+) pools with
endoplasmatic Ca(2+)-ATP-ase inhibitor thapsigargin leads to the Na(+) influx in
human lymphocytes (M. Tepel et al., 1994, J. Biol. Chem. 269, 26239-26242). In
the present study we examined the mechanism underlying the thapsigargin-induced
Na(+) entry. We found that the thapsigargin-induced increase in Na(+)
concentration was effectively inhibited by three structurally unrelated
phospholipase A(2) (PLA(2)) inhibitors, p-bromophenacyl bromide, 3-(4-octadecyl)
benzoylacrylic acid (OBAA), and bromoenol lactone (BEL). The thapsigargin-induced
Na(+) influx could be mimicked by PLA(2) exogenously added to the lymphocyte
suspension. In addition, thapsigargin stimulated formation of arachidonic acid
(AA), the physiological PLA(2) product. AA induced Na(+) entry in a time- and
concentration-dependent fashion. Both, thapsigargin-induced Na(+) influx and AA
liberation were completely inhibited in the presence of tyrosine kinase inhibitor
genistein but not in the absence of extracellular Ca(2+). Collectively, these
data show that thapsigargin-induced Na(+) entry is associated with tyrosine
kinase-dependent stimulation of PLA(2).
PMID- 10666301
TI - Interaction of lactoferrin with ceruloplasmin.
AB - When added to human blood serum, the iron-binding protein lactoferrin (LF)
purified from breast milk interacts with ceruloplasmin (CP), a copper-containing
oxidase. Selective binding of LF to CP is evidenced by the results of
polyacrylamide gel electrophoresis, immunodiffusion, gel filtration, and affinity
chromatography. The molar stoichiometry of CP:LF in the complex is 1:2. Near-uv
circular dichroism spectra of the complex showed that neither of the two proteins
undergoes major structural perturbations when interacting with its counterpart.
K(d) for the CP/LF complex was estimated from Scatchard plot as 1.8 x 10(-6) M.
The CP/LF complex is found in various fluids of the human body. Upon injection
into rat of human LF, the latter is soon revealed within the CP/LF complex of the
blood plasma, from where the human protein is substantially cleared within 5 h.
PMID- 10666302
TI - Identification of a beta-like DNA polymerase activity in bovine heart
mitochondria.
AB - A new DNA polymerase activity, distinct from DNA polymerase gamma, has been
identified in bovine heart mitochondria. First detected among proteins isolated
in a complex with mitochondrial DNA, the DNA polymerase activity has been
partially purified 47,000-fold. Enzyme activity separates from DNA polymerase
gamma on several chromatographic columns and appears to copurify with a 38 +/- 2
kDa polypeptide. Unlike DNA polymerase gamma, this enzyme is relatively resistant
to inhibition by N-ethylmaleimide and dideoxynucleotides, has moderately low
monovalent and high divalent cation requirements, and possesses 20-fold-higher
apparent K(m) values for deoxynucleotides. The enzyme polymerizes
deoxynucleotides onto a primed template DNA in a relatively nonprocessive fashion
and lacks a detectable 3' to 5' exonuclease activity. Many of these
characteristics resemble a beta-like mitochondrial DNA polymerase previously
identified in, and considered unique to, trypanosomes. We propose that the bovine
and trypanosomal enzymes are related and represent a new class of ubiquitous
mitochondrial DNA polymerases.
PMID- 10666303
TI - Biophysical study of the perturbation of model membrane structure caused by
seminal plasma protein PDC-109.
AB - PDC-109, the major heparin-binding protein of bull seminal plasma, binds
specifically to sperm choline lipids at ejaculation and mediates capacitation by
stimulating cholesterol and phospholipid efflux. We carried out a biophysical
study to investigate the membrane perturbation effect caused by PDC-109. Binding
of PDC-109 to phosphatidylcholine model membranes was maximal at a 12:1
phosphatidylcholine to protein molar ratio. The process was independent of the
membrane structure and involved a slight conformational change of the protein,
compatible with an increased exposure to the solvent. PDC-109 binding to
dimyristoylphosphatidylcholine prevented lipid molecules from participating in
the gel-to-liquid phase transition, due to enhancement of both acyl chain
disorder and interfacial hydration. Visualization of the lipid-protein complexes
by electron microscopy showed surface irregularities and the presence of 10-nm
particles. Permeability assays confirmed the PDC-109-induced disruption of the
vesicles. This effect was not modified by heparin. However, presence of
cholesterol inhibited the process in a concentration-dependent manner.
PMID- 10666304
TI - The multiple active enzyme species of gamma-aminobutyric acid aminotransferase
are not isozymes.
AB - Purified gamma-aminobutyric acid aminotransferase (GABA-AT) from pig brain under
certain conditions gave a single band on 12% NaDodSO(4)-PAGE, whereas two or
three distinct bands were observed on 7.5% native PAGE. These multiple active
species were isolated by 5% preparative gel electrophoresis and characterized by
N-terminal sequencing and MALDI-TOF mass spectrometry. The results indicate that
these active enzyme species are not GABA-AT isozymes in pig brain, but are the
products of proteolysis of the N-terminus of GABA-AT, differing by 3, 7, and 12
residues from the full sequence (as deduced from the cDNA), respectively.
Conditions for obtaining the nontruncated GABA-AT were found, and the potential
cause for the proteolysis was determined. It was found that Na(2)EDTA inhibits
the N-terminal cleavage during GABA-AT preparation from pig brain. The presence
of Triton X-100 in the homogenization step is partially responsible for this
proteolysis, and Mn(2+) strongly enhances the protease activity, suggesting the
presence of a membrane-bound matrix metalloprotease that causes the N-terminal
cleavage.
PMID- 10666305
TI - Induction of arginase II in human Caco-2 tumor cells by cyclic AMP.
AB - The objective of this study was to elucidate the mechanism by which cyclic AMP
increases arginase activity in cultured human Caco-2 tumor cells. Caco-2 cells
were incubated for 24 h in the presence of 8-bromo cyclic AMP or forskolin, and
the cells were harvested, lysed, and assayed for total arginase activity. Both
test agents increased arginase activity by twofold, and this was attributed to
the induction of the arginase II isoform. Both arginase II mRNA and protein
showed increased expression in response to 8-bromo cyclic AMP and forskolin, and
these effects were inhibited by H-89 (protein kinase A inhibitor), enhanced by
okadaic acid (phosphatase inhibitor), and enhanced by 1-methyl-3-isobutylxanthine
(cyclic nucleotide phosphodiesterase inhibitor). Cyclic GMP did not appear to be
involved in arginase II induction. These observations indicate that cyclic AMP
stimulates arginase II gene expression by mechanisms involving activation of
protein kinase A and consequent activation of appropriate transcription factors.
PMID- 10666306
TI - Cloning and characterization of glyoxalase I from soybean.
AB - Glyoxalase I and glutathione transferase (GST) are two glutathione-dependent
enzymes which are enhanced in plants during cell division and in response to
diverse stress treatments. In soybean, a further connection between these two
enzymes has been suggested by a clone (Accession No. X68819) resembling a GST
being described as a glyoxalase I. To characterize glyoxalase I in soybean,
GmGlyox I resembling the dimeric enzyme from animals has been cloned from a cDNA
library prepared from soybean suspension cultures. When expressed in Escherichia
coli, GmGlyox I was found to be a 38-kDa dimer composed of 21-kDa subunits and
unlike the enzyme from mammals showed activity in the absence of metal ions.
GmGlyox I was active toward the hemithioacetal adducts formed by reacting
methylglyoxal, or phenylglyoxal, with glutathione, homoglutathione, or gamma
glutamylcysteine, showing no preference for homoglutathione adducts over
glutathione adducts, even though homoglutathione is the dominant thiol in
soybean. When the clone X68819 was expressed in E. coli, the respective
recombinant enzyme was active as a GST rather than a glyoxalase and was termed
GmGST 3. GmGST 3 was active as a homodimer (45 kDa) composed of 26-kDa subunits
and showed a preference for glutathione over homoglutathione when conjugating 1
chloro-2,4-dinitrobenzene. Both enzymes are associated with cell division in
soybean cultures, but GmGST 3 (0.4% total protein) was 40 times more abundant
than GmGlyox I (0.01%).
PMID- 10666307
TI - The importance of SRS-1 residues in catalytic specificity of human cytochrome
P450 3A4.
AB - The structural basis for the regioselective hydroxylation of Delta-4-3
ketosteroids by human CYP3A4 was investigated. Prior studies had suggested that
the chemical reactivity of the allylic 6beta-position might have a greater
influence than steric constraints by the enzyme. Six highly conserved CYP3A
residues from substrate recognition site 1 were examined by site-directed
mutagenesis. F102A and A117L showed no spectrally detectable P450. V101G and
T103A exhibited a wild-type progesterone metabolite profile. Of five mutants at
residue N104, only N104D yielded holoenzyme and exhibited the same steroid
metabolite profile as wild-type. Of four mutants at position S119 (A, L, T, V),
the three hydrophobic ones produced 2beta-OH rather than 6beta-OH progesterone or
testosterone as the major metabolite. Kinetic analysis showed S(50) values
similar to wild-type for S119A (progesterone) and S119V (testosterone), whereas
the V(max) values for 2beta-hydroxysteroid formation were increased in both
cases. All four mutants exhibited an altered product profile for 7-hexoxycoumarin
side-chain hydroxylation, whereas the stimulation of steroid hydroxylation by
alpha-naphthoflavone was similar to the wild-type. The results indicate that the
highly conserved residue S119 is a key determinant of CYP3A4 specificity and
reveal an important role of the active site topology in steroid 6beta
hydroxylation.
PMID- 10666308
TI - Carvedilol inhibits the exogenous NADH dehydrogenase in rat heart mitochondria.
AB - There are several reports on the oxidation of external NADH by an exogenous NADH
dehydrogenase in the outer leaflet of the inner membrane of rat heart
mitochondria. Until now, however, little was known about its physiological role
in cellular metabolism. The present work shows that carvedilol (?1-[carbazolyl
(4)-oxy]-3-[2-methoxyphenoxyethyl)amino]-pro - panol-(2)?) is a specific
inhibitor of an exogenous NADH dehydrogenase in rat heart mitochondria.
Carvedilol does not affect oxygen consumption linked to the oxidation of
succinate and internal NADH. It is also demonstrated that the inhibition of
exogenous NADH dehydrogenase by carvedilol is accompanied by the inhibition of
alkalinization of the external medium. In contrast to the addition of
glutamate/malate or succinate, exogenous NADH does not generate a membrane
potential in rat heart mitochondria, as observed with a TPP(+) electrode. It is
also demonstrated that the oxygen consumption linked to NADH oxidation is not due
to permeabilized mitochondria, but to actual oxidase activity in the inner
membrane. The enzyme has a K(m) for NADH of 13 microM. Carvedilol is a
noncompetitive inhibitor of this external NADH dehydrogenase with a K(i) of 15
microM. Carvedilol is the first inhibitor described to this organospecific
enzyme. Since this enzyme was demonstrated to play a key role in the
cardiotoxicity of anticancer drugs of the anthracycline family (e.g.,
adriamycin), we may suggest that the administration of carvedilol to tumor
patients treated with adriamycin might be of great help in the prevention of the
cardioselective toxicity of this antibiotic.
PMID- 10666309
TI - Sterol regulatory element binding protein-mediated effect of fluvastatin on
cytosolic 3-hydroxy-3-methylglutaryl-coenzyme A synthase transcription.
AB - The effects of acute treatment with fluvastatin, a hypocholesteremic drug, on the
mRNA levels of several regulatory enzymes of cholesterogenesis and of the LDL
receptor were determined in rat liver. Fluvastatin increased the hepatic mRNA
levels for HMG-CoA reductase up to 12-fold in 5 weeks of treatment at a daily
dose of 6. 3 mg/kg. The effect was less marked in cytosolic HMG-CoA synthase,
farnesyl-PP synthase, squalene synthetase, and LDL receptor. SREBP-2 mRNA levels
were also increased, but SREBP-1 were not. De novo synthesis of cholesterol in
several cultured cells was reduced by increasing concentrations of fluvastatin,
and the IC(50) values of fluvastatin in HepG2, CV-1, and CHO cells were
respectively 0.01, 0. 05, and 0.1 microM. When CHO cells stably transfected with
a chimeric gene composed of the promoter of cytosolic HMG-CoA synthase and the
CAT gene as a reporter were incubated with fluvastatin, the CAT gene was
overexpressed, an effect which was similar to the cotransfection with the
processed form of SREBP-1a. Both ALLN and fluvastatin increased the
transcriptional activity of cytosolic HMG-CoA synthase. Mutation in either SRE or
NF-Y boxes abolished the increase in transcriptional rate caused by fluvastatin
in the promoter of cytosolic HMG-CoA synthase. These results indicate that the
increase in transcriptional activity in the HMG-CoA synthase gene attributable to
fluvastatin is a consequence of the activation of the proteolytic cleavage of
SREBPs by reduced levels of intracellular cholesterol.
PMID- 10666310
TI - Evidence for requirement of NADPH-cytochrome P450 oxidoreductase in the
microsomal NADPH-sterol Delta7-reductase system.
AB - Rabbit antibodies raised against the hydrophilic part of microsomal NADPH
cytochrome P450 oxidoreductase (denoted fpT) demonstrated a marked ability to
inhibit NADPH-sterol Delta7-reductase activity. In addition, trypsin and
proteinase K treatment of microsomes removed almost all microsomal electron
transfer constituents from the microsomes, but the Delta7-reductase activity
could be reconstituted by adding detergent-solubilized NADPH-cytochrome P450
oxidoreductase (denoted OR). Furthermore, after solubilization from microsomes,
the Delta7-reductase activity could be reconstituted with OR in a DEAE-cellulose
column chromatography eluate fraction, which contained little OR activity. In the
microsomal system, carbon monoxide, ketoconazole, and miconazole, specific
inhibitors of cytochrome P450, had no effect on Delta7-reductase activity. These
results provide the first evidence of an essential requirement of OR, which is
distinct from cytochrome P450, in the NADPH-sterol Delta7-reductase system. EDTA,
o-phenanthroline and KCN markedly lowered Delta7-reductase activity in a dose
dependent manner. Among metal ions tested, only ferric ion restored the reductase
activity in the EDTA-treated microsomes. These results sugguest that NADPH-sterol
Delta7-reductase is membrane-bound iron-dependent protein embedded in the
microsomal lipid bilayer.
PMID- 10666311
TI - Effects of epinephrine infusion on expression of calpastatin in porcine cardiac
and skeletal muscle.
AB - beta-Adrenergic agonists induce muscle hypertrophy in mammalian species and alter
the extractable activity of calpain proteinase and its specific endogenous
inhibitor calpastatin. The effects on skeletal and cardiac muscle calpastatin of
continuously infusing a group of pigs for 7 days with the physiological agonist
epinephrine (0.15 microg/kg/min) were examined and compared with a placebo group.
Basal levels of extractable calpastatin activity were higher in cardiac than
skeletal muscle and epinephrine infusion increased the extractable activity in
both muscle types (P < 0.05). An anti-recombinant porcine calpastatin antiserum
detected a 135-kDa band and a 145/135-kDa doublet on Western blots of skeletal
and cardiac extracts, respectively. Epinephrine infusion increased the 135-kDa
band in skeletal muscle (P < 0.05), while the ratio of 145/135 kDa in cardiac
muscle was decreased (P < 0.05). From Northern blots, the patterns of calpastatin
mRNA species were similar in the two muscle types, two major transcripts at 5.8
and 3. 2 kb in cardiac muscle, with equivalent bands in skeletal muscle of 5.4
and 2.8 kb. A faint 7.9-kb band was also detected in skeletal muscle. Epinephrine
infusion had no effect on skeletal calpastatin mRNA but tended to increase the
5.8-kb mRNA in cardiac muscle (P = 0. 053). These data indicate a differential
response of the two muscle types to mildly elevated plasma epinephrine
concentration and the response to elevated epinephrine may be at the
translational or posttranslational level. Therefore, this type of stimulus
appears to be less effective at perturbing calpastatin gene transcription than
certain orally administered synthetic beta-adrenergic agonists.
PMID- 10666312
TI - Ubiquitylation and destruction of endogenous c-mycS by the proteasome: are myc
boxes dispensable?
AB - c-MycS proteins are truncated forms of the transcription factor which have been
shown to be produced by translation initiation at internal methionines (101, 121,
and 134) and to be functional in the regulation of gene expression, cell
proliferation, and apoptosis. Treatment of human leukemia HL60 cells with
lactacystin, a specific inhibitor of the proteasome, increased the steady-state
levels of endogenous c-MycS proteins. The half-life of endogenous [(35)S]MycS was
similar to that of c-Myc ( approximately 23 min) in HL60 cells. c-Myc(Delta2
143), which lacks the transcription regulatory domain, had a half-life which was
similar to that of endogenous c-Myc in 293 and HL60 cells. Treatment of the cells
with lactacystin stabilized [(35)S]Myc(Delta2-143) and [(35)S]Myc and caused
multi-ubiquitin conjugates of c-Myc, c-MycS, and Myc(Delta2-143) to accumulate.
These findings indicate that the Myc homology boxes and the rest of the
transcription regulatory domain (the first 144 amino acids) are dispensable for
ubiquitylation and rapid destruction of c-MycS and c-Myc by the proteasome.
PMID- 10666313
TI - TGF-beta1 stimulation of fibronectin transcription in cultured human lung
fibroblasts requires active geranylgeranyl transferase I, phosphatidylcholine
specific phospholipase C, protein kinase C-delta, and p38, but not erk1/erk2.
AB - The cytokine transforming growth factor-beta (TGF-beta) has multiple effects on a
variety of cell types, modulating cell growth and differentiation as well as
extracellular matrix deposition and degradation. In the present work, we
demonstrate that TGF-beta1 produces a fourfold increase in transcription of the
fibronectin gene in cultured human fetal lung fibroblasts with only a small
increase in mRNA stability resulting in a significant increase in fibronectin
mRNA steady state level. A corresponding increase in production of fibronectin
protein accompanied the increase in mRNA. Through the use of specific inhibitors,
we demonstrate that geranylgeranylated, but not farnesylated or acylated
protein(s), protein kinase C-delta, phosphatidylcholine-specific phospholipse C,
tyrosine kinase activity, and stress-activated protein kinase p38 are required
for this TGF-beta1 effect. Trimeric G proteins and mitogen-activated protein
kinases erk1 and erk2 do not appear to be involved. While these results emphasize
the complexities involved in the control of extracellular matrix synthesis by TGF
beta, they also identify reaction sites that may be amenable to pharmacologic
modulation. Such modulation could be of great advantage in the treatment of a
wide variety of undesirable fibrotic reactions.
PMID- 10666314
TI - Proteasome inhibition in neuronal cells induces a proinflammatory response
manifested by upregulation of cyclooxygenase-2, its accumulation as ubiquitin
conjugates, and production of the prostaglandin PGE(2).
AB - Inclusions containing ubiquitin-protein aggregates appear in neurons of patients
with neurodegenerative disorders such as Alzheimer's disease and Parkinson's
disease. The relationship between inclusion production and cell viability is not
understood. To address this issue, we investigated the response of an established
mouse neuronal cell line and of embryonic rat mesencephalic cultures to
inhibition of the ubiquitin/proteasome pathway. Two proteasome inhibitors, a
peptidyl aldehyde and an epoxy ketone, which cause accumulation of ubiquitinated
proteins, were found to enhance expression of stress-inducible genes, including
HSP70i and the polyubiquitin genes UbB and UbC. Under these conditions, mRNA and
protein levels of the inducible form of cyclooxygenase (COX-2) were upregulated
together with its product, PGE(2), a proinflammatory prostaglandin. Proteasomal
inhibition also led to stabilization of COX-2 as ubiquitin conjugates, suggesting
that the ubiquitin/proteasome pathway contributes to the regulation of COX-2
protein levels. Treatment with antioxidants known to inhibit NFkappaB and AP-1
transcriptional activation failed to abrogate COX-2 upregulation. Instead, these
inhibitors exacerbated the stress response by potentiating HSP70i levels while
eliciting a decrease in PGE(2) production. These findings suggest that the
accumulation of ubiquitinated proteins resulting from proteasome inhibition in
neuronal cells is associated with a proinflammatory response that may be an
important contributor to neurodegeneration.
PMID- 10666315
TI - Expression of 1,25-dihydroxyvitamin D(3) receptor in the immune system.
AB - In addition to its role in calcium and skeletal homeostasis, there is increasing
evidence that the hormonal form of vitamin D, 1, 25-dihydroxyvitamin D(3),
appears to serve as a modulator of the immune system. We have determined the
level of the 1, 25-dihydroxyvitamin D(3) receptor (VDR) in resting and activated
lymphocytes by immuno- and ligand-binding assays. As expected from previous work,
the total T lymphocyte population contains VDR whose levels are increased when
activated and treated with 1, 25-dihydroxyvitamin D(3). Surprisingly, the highest
concentrations of VDR are found in CD8 lymphocytes, although significant amounts
are also present in CD4 lymphocytes. Furthermore, B lymphocytes do not contain
detectable amounts of VDR. Cells of the monocyte/macrophage lineage possess small
amounts of VDR that are not affected by activation but are increased by treatment
with 1, 25-dihydroxyvitamin D(3). These results suggest that CD8 lymphocytes may
be a major site of 1,25-dihydroxyvitamin D(3) action, while B lymphocytes are
likely not directly regulated by 1, 25-dihydroxyvitamin D(3).
PMID- 10666316
TI - Inhibition of c-Jun expression induces antioxidant enzymes under serum
deprivation.
AB - We previously reported that antisense c-jun suppressed apoptosis induced by serum
deprivation in F-MEL cells. To elucidate the molecular mechanisms responsible for
this suppression of apoptosis we investigated the activities and protein
expression of antioxidant materials in the cell under serum deprivation. In the
parental F-MEL cells enzyme activities of catalase, glutathione S-transferase
(GST), and glutathione peroxidase (GPx) increased to reach the maximum at 24-72 h
after removal of serum and then decreased to initial levels or a little less.
Superoxide dismutase (SOD) maintained the initial level for 72 h and increased
1.5- to 2-fold at 96 h. Glutathione (GSH) levels increased at 24 h and then
dropped significantly to one-third the initial level. On the other hand, in c
junAS (+) cells, in which antisense c-jun was expressed and c-Jun protein
expression was reduced to undetectable level. We found 1.9-, 2.7-, 4.8-, and 15.
8-fold increase in the activities of catalase, GST, SOD, and GPx, respectively,
at 96 h. GSH maintained almost the same level as the initial. Enhancement of
these enzyme activities in c-junAS (+) cells was induced under serum deprivation.
Western blottings for catalase, GST, and SOD also showed enhanced increase in
protein expression, supporting the increase in enzyme activities. Cellular
peroxide level under serum deprivation was monitored by flow cytometry using DCFH
DA as a probe. We found that the peroxide level increased at 24 h and then
decreased at 72 and 96 h in c-junAS (+) cells, and reduction of the peroxide
level coincided with an increase in antioxidant enzyme activities. These results
indicate that antioxidant materials such as catalase, GST, SOD, GPx, and GSH are
induced by serum deprivation when c-jun expression is inhibited in F-MEL cells.
The link between inhibition of c-jun expression and enhancement of cellular
antioxidant defense is discussed.
PMID- 10666317
TI - Electron paramagnetic resonance studies of radical species of proanthocyanidins
and gallate esters.
AB - The polyphenols present in green tea or red wine comprise both regular
flavon(ol)s and proanthocyanidins, i.e., derivatives of flavan-3-ols, whose
distinct antioxidative potential is of great importance for explaining the
beneficial effects of these nutrient beverages. Using EPR spectroscopy, we
investigated radical structures obtained after oxidation of the parent compounds
either by horseradish peroxidase/hydrogen peroxide or after autoxidation in
moderately alkaline solutions. Both proanthocyanidins (monomers of condensed
tannins, e.g., (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, (-)
epigallocatechin, (-)-epigallocatechin gallate, Pycnogenol) and gallate esters
(hydrolyzable tannins, e.g., propylgallate, beta-glucogallin, pentagalloyl
glucose and tannic acid) yielded predominantly semiquinone structures derived
from the parent catechol or pyrogallol moieties. Evidence for a time-dependent
oligomerization was obtained for (-)-epigallocatechin gallate, supporting our
hypothesis that o-quinones formed from the initial semiquinone disproportionation
are prone to nucleophilic addition reactions. Such phenolic coupling reactions
would retain the numbers of reactive catechol/pyrogallol structures and thus the
antioxidative potential. We therefore propose that proanthocyanidins are superior
antioxidants as compared to flavon(ol)s proper, whose quinones are more likely to
redox-cycle and act as prooxidants.
PMID- 10666318
TI - Distinct contributions of glycoprotein VI and alpha(2)beta(1) integrin to the
induction of platelet protein tyrosine phosphorylation and aggregation.
AB - Platelet activation by collagen depends principally on two receptors,
alpha(2)beta(1) integrin (GPIa-IIa) and GPVI. During this activation, the
nonreceptor protein tyrosine kinase pp72(syk) is rapidly phosphorylated, but the
precise contribution of alpha(2)beta(1) integrin and GPVI to signaling for this
phosphorylation is not clear. We have recently found that proteolysis of platelet
alpha(2)beta(1) integrin by the snake venom metalloproteinase, jararhagin,
results in inhibition of collagen-induced platelet aggregation and pp72(syk)
phosphorylation. In order to verify whether the treatment of platelets with
jararhagin had any effect on GPVI signaling, in this study we stimulated
platelets treated with either jararhagin or anti-alpha(2)beta(1) antibody with
two GPVI agonists, an antibody to GPVI and convulxin. Platelet shape change and
phosphorylation of pp72(syk) by both GPVI agonists was preserved, as was the
structure and function of GPVI shown by (125)I-labeled convulxin binding to
immunoprecipitated GPVI from jararhagin-treated platelets. In contrast, defective
platelet aggregation in response to GPVI agonists occurred in both jararhagin
treated and alpha(2)beta(1)-blocked platelets. This apparent cosignaling role of
alpha(2)beta(1) integrin for platelet aggregation suggests the possibility of a
topographical association of this integrin with GPVI. We found that both platelet
alpha(2)beta(1) integrin and GPVI coimmunoprecipitated with alpha(IIb)beta(3)
integrin. Since platelet aggregation requires activation of alpha(IIb)beta(3)
integrin, defective aggregation in the absence of alpha(2)beta(1) suggests that
this receptor may provide a signaling link between GPVI and alpha(IIb)beta(3).
Our study therefore demonstrates that platelet signaling leading to pp72(syk)
phosphorylation initiated with GPVI engagement by either convulxin or GPVI
antibody does not depend on alpha(2)beta(1) integrin. However, alpha(IIb)beta(3)
integrin may, in this model, require functional alpha(2)beta(1) integrin for its
activation.
PMID- 10666319
TI - The Ang II-induced growth of vascular smooth muscle cells involves a
phospholipase D-mediated signaling mechanism.
AB - Angiotensin (Ang) II acts as a mitogen in vascular smooth muscle cells (VSMC) via
the activation of multiple signaling cascades, including phospholipase C,
tyrosine kinase, and mitogen-activated protein kinase pathways. However,
increasing evidence supports signal-activated phospholipases A(2) and D (PLD) as
additional mechanisms. Stimulation of PLD results in phosphatidic acid (PA)
formation, and PA has been linked to cell growth. However, the direct involvement
of PA or its metabolite diacylglycerol (DAG) in Ang II-induced growth is unclear.
PLD activity was measured in cultured rat VSMC prelabeled with [(3)H]oleic acid,
while the incorporation of [(3)H]thymidine was used to monitor growth. We have
previously reported the Ang II-dependent, AT(1)-coupled stimulation of PLD and
growth in VSMC. Here, we show that Ang II (100 nM) and exogenous PLD (0.1-100
units/mL; Streptomyces chromofuscus) stimulated thymidine incorporation (43-208%
above control). PA (100 nM-1 microM) also increased thymidine incorporation to
135% of control. Propranolol (100 nM-10 microM), which inhibits PA
phosphohydrolase, blocked the growth stimulated by Ang II, PLD, or PA by as much
as 95%, an effect not shared by other beta-adrenergic antagonists. Propranolol
also increased the production of PA in the presence of Ang II by 320% and reduced
DAG and arachidonic acid (AA) accumulation. The DAG lipase inhibitor RHC-80267 (1
10 microM) increased Ang II-induced DAG production, while attenuating thymidine
incorporation and release of AA. Thus, it appears that activation of PLD,
formation of PA, conversion of PA to DAG, and metabolism of DAG comprise an
important signaling cascade in Ang II-induced growth of VSMC.
PMID- 10666320
TI - Molecular cloning of a taxa-4(20),11(12)-dien-5alpha-ol-O-acetyl transferase cDNA
from Taxus and functional expression in Escherichia coli.
AB - The taxa-4(20),11(12)-dien-5alpha-ol-O-acetyl transferase which catalyzes the
third step of Taxol biosynthesis has been isolated from methyl jasmonate-induced
Taxus cells, and partially purified and characterized (K. Walker, R. E. B.
Ketchum, M. Hezari, D. Gatfield, M. Golenowski, A. Barthol, and R. Croteau, Arch.
Biochem. Biophys. 364, 273-279 1999). A revised purification method allowed
internal amino acid microsequencing of the enzyme, from which primers were
designed and employed to amplify a transacetylase gene-specific fragment. This
radiolabeled, 900-bp amplicon was used as a hybridization probe to screen a cDNA
library constructed from poly(A)(+) RNA isolated from induced Taxus cells, from
which a full-length transacetylase sequence was obtained. Expression of this
clone from pCWori(+) in Escherichia coli JM109 cells yielded the functional
enzyme, as determined by radiochemical assay and combined capillary gas
chromatographic-mass spectrometric verification of the acetylated product. The
full-length DNA has an open-reading frame of 1317 nucleotides corresponding to a
deduced amino acid sequence of 439 residues that exhibits high sequence identity
to the proteolytic fragments of the native enzyme, which the recombinant
transacetylase resembles in properties. Consistent with the size of the
operationally soluble native enzyme, the DNA appears to encode a monomeric
protein of molecular weight 49,079 that bears no N-terminal organellar targeting
information. Sequence comparison of the taxadien-5alpha-ol-O-acetyl transferase
with the few other known acyl transferases of plant origin indicates a
significant degree of similarity between these enzymes (64-67%). The efficient
conversion of taxadien-5alpha-yl acetate to further hydroxylated intermediates of
the Taxol pathway confirms the significance of this acylation step and suggests
this taxadienol transacetylase to be an important target for genetic manipulation
to improve Taxol production.
PMID- 10666321
TI - Cloning, heterologous expression, and enzymological characterization of human
squalene monooxygenase.
AB - The cDNA for human squalene monooxygenase, a key enzyme in the committed pathway
for cholesterol biosynthesis, was amplified from a human liver cDNA library and
cloned, and the protein was expressed in Escherichia coli and purified. Kinetic
analysis of the purified enzyme revealed an apparent K(m) for squalene of 7.7
microM and an apparent k(cat) of 1.1 min(-1). For FAD the apparent K(m) is 0.3
microM, consistent with a loosely bound flavin. The apparent K(m) for NADPH
cytochrome P450 reductase, the requisite electron transfer partner, is 14 nM. The
amount of reductase needed for maximal activity is about threefold less than the
amount of squalene monooxygenase present in the assay; thus, electron transfer to
the monooxygenase is not likely to be rate limiting. Previous reports have
implicated inhibition of this enzyme as the cause of a peripheral demyelination
seen in weanling rats fed a diet containing tellurium. As no data were available
for humans, the ability of a number of tellurium and related elemental compounds
to inhibit the recombinant human enzyme was examined. Tellurite, tellurium
dioxide, selenite, and selenium dioxide were inhibitory; the tellurium compounds
were more potent than the selenium compounds, as indicated by their IC(50) values
(17 and 37 microM, respectively). Kinetic analysis of the inhibition by tellurite
suggests multiple sites of interaction with the enzyme in a noncompetitive manner
with respect to squalene.
PMID- 10666322
TI - Lys-Ala mutations of type I adenylyl cyclase result in altered susceptibility to
inhibition by adenine nucleoside 3'-polyphosphates.
AB - Native and recombinant wild type and mutant forms of type I adenylyl cyclase,
expressed in fall army worm ovarian cells (Sf9) cells, with mutations Lys-923
Ala, Lys-921-Ala, and Lys-350-Ala, retained the characteristic noncompetitive
inhibition by adenine nucleoside 3'-polyphosphates, but exhibited substantially
different sensitivities to inhibition by them. The type I K923A enzyme resulted
in increased IC(50) values, e.g., >100-fold for 2'-deoxyadenosine-3'
monophosphate, but the shift diminished as the number of 3'-phosphates increased.
The K921A mutation increased IC(50) values approximately 5-fold for all adenine
nucleosides tested, whereas the K350A mutation increased IC(50) values
approximately 6- to 8-fold for all adenine nucleosides tested except 2'
deoxyadenosine-3'-diphosphate, which was increased >/=2-fold. The data suggest
that 3'-phosphates sufficiently increase binding affinity of these ligands to
compensate for the reduced coordination of the adenine moiety induced by the
K923A mutation. Moreover, the altered structures induced by both K350A and K921A
mutations impair ligand binding in general, but paradoxically those resulting
from the K350A change minimally affected nucleoside 3'-diphosphate binding,
implying that selective changes in ligand binding can be induced by this site
specific mutation.
PMID- 10666323
TI - Relationship between total and free cellular Mg(2+) during metabolic stimulation
of rat cardiac myocytes and perfused hearts.
AB - The changes in total Mg were compared with changes in cytosolic free Mg(2+)
during metabolic stimulation of collagenase-dispersed rat cardiac myocytes or
Langendorff-perfused rat hearts. In myocytes the addition of agents leading to
cAMP increase or protein kinase C activation results in a loss or gain of more
than 5% of total Mg content within 3 min (i.e., 3-4 nmol Mg/mg protein). Under
the same conditions, changes in cytosolic free Mg(2+) measured with fluorescent
indicator are small and result in changes of cytosolic free Mg(2+) equivalent to
90-140 microM. In perfused hearts, beta-adrenergic stimulation results in a loss
of total Mg larger than 0.5 micromol per gram of heart corresponding to 9% loss
of total Mg content of the heart (estimated to be 5.8 micromol). Under these
conditions there is no change in cytosolic free Mg(2+) or the major buffer of
cytosolic Mg(2+), ATP, as measured by (31)P NMR. These data suggest that a major
redistribution of total Mg occurs in intracellular organelles or in cytosolic
buffers in order to maintain cytosolic free Mg(2+) relatively unchanged during
the observed cellular massive translocation of total Mg. Hence, Mg(2+) may
regulate metabolic functions not within the cytosol but in locations where its
concentration oscillates, such as extracellular fluid and intracellular
compartments.
PMID- 10666324
TI - Gender differences in advanced mathematical problem solving.
AB - Strategy flexibility in mathematical problem solving was investigated. In Studies
1 and 2, high school juniors and seniors solved Scholastic Assessment Test
Mathematics (SAT-M) problems classified as conventional or unconventional.
Algorithmic solution strategies were students' default choice for both types of
problems across conditions that manipulated item format and solution time. Use of
intuitive strategies on unconventional problems was evident only for high-ability
students. Male students were more likely than female students to successfully
match strategies to problem characteristics. In Study 3, a revised taxonomy of
problems based on cognitive solution demands was predictive of gender differences
on Graduate Record Examination-Quantitative (GRE-Q) items. Men outperformed women
overall, but the difference was greater on items requiring spatial skills,
shortcuts, or multiple solution paths than on problems requiring verbal skills or
mastery of classroom-based content. Results suggest that strategy flexibility is
a source of gender differences in mathematical ability assessed by SAT-M and GRE
Q problem solving.
PMID- 10666325
TI - A new model of verbal short-term memory.
AB - Two experiments tested a neo-Piagetian model of verbal short-term memory and
compared it with the articulatory loop model. Experiment 1 (n = 113, age range 9
11) tested word span for 2-, 3-, and 4-syllable words, with both visual and
auditory presentation. Experiment 2 (with the same participants) tested recall of
visually presented supraspan lists. Measures of M capacity (as conceived in
Pascual-Leone's neo-Piagetian theory) and articulation rate were also used. The
proposed model can account for the effects of M capacity, word length, and
presentation modality. The fit of this model to the data was acceptable, and
parameter estimates were consistent across experiments. Furthermore, a
correlation was found between M capacity and word span which resisted partialling
out of age and articulation rate.
PMID- 10666326
TI - Movement substructures change as a function of practice in children and adults.
AB - An experiment is reported in which participants at 6 (n = 20), 9 (n = 20), and 24
years (n = 20) of age either received or did not receive practice on a rapid
aiming task using the arm and hand. The purpose of the experiment was to document
the changes in movement substructures (in addition to movement time) as a
function of practice. After receiving 10 baseline trials, subjects in the
practice groups received 30 practice trials followed by 10 retention trials on
each of 5 days, while subjects in the no-practice group had only baseline and
retention trials. Retention-only trials were divided into primary (reflecting the
ballistic controlled part of the movement) and secondary (reflecting corrective
movement adjustments) submovements. In addition, jerk (the 3rd derivative of
movement displacement) was calculated as an estimate of the smoothness of the
movement. Participants increased the primary submovement as a function of
practice; however, the increases were substantially larger in the children (25
30%) than in the adults (10%). Participants also decreased jerk as a function of
practice and the decreases were greater in children than in adults. The results
suggest that with practice the primary submovement is lengthened so that it ends
nearer the target, especially in children. Associated with the primary
submovement covering a larger percentage of the movement length and time,
movements became smoother.
PMID- 10666327
TI - Fibrous structures within the matrix of developing chick embryo mitochondria.
PMID- 10666328
TI - Vertebrate mitochondrial DNA-a circle of surprises.
AB - Evidence for the existence of a vertebrate mitochondrial genome first arose over
30 years ago. Application of emerging techniques of molecular biology established
the structure of vertebrate mitochondrial DNA (mtDNA) as a small closed-circular
species. The ability to purify these mtDNAs to a high degree facilitated studies
on the overall replication and expression pattern of the genome. With the
acquisition of the genomic sequences of human and mouse mtDNAs, it was possible
to infer the genetic organization and some of the genes contained therein, as
well as providing a basis for developing strategies to assign important
regulatory elements involved in mtDNA replication and transcription. This, in
turn, presented the opportunity to identify nucleus-encoded proteins that target
to mtDNA and, in doing so, determine the replication and expression modes of the
genome. Vertebrate cells, in general, need mtDNA due to the requirements for
maintaining a functional oxidative phosphorylation pathway. Depression of mtDNA
content or mutations in mtDNA can result in metabolic dysfunction severe enough,
in some cases, to result in human lethality. The emergence of mouse models for
human mitochondrial diseases should provide the experimental context to
understand the full role of mtDNA in different cells, tissues, and organs; the
control of organelle biogenesis; and the development of therapeutic strategies
for treatment of mitochondrial disorders.
PMID- 10666329
TI - Integrins alpha5beta1, alphavbeta1, and alphavbeta6 collaborate in squamous
carcinoma cell spreading and migration on fibronectin.
AB - The expression of alphavbeta6 fibronectin/tenascin receptor integrin is induced
in malignant transformation of oral epithelium. In this study, we demonstrate the
contribution of alphavbeta6 as well as other fibronectin receptor integrins in
squamous cell carcinoma (SCC) cell adhesion and migration. Of 11 SCC cell lines
isolated from the head and neck area, 8 (73%) expressed alphavbeta6 integrin on
the cell surface. Three cell lines were chosen for further functional
experiments: 1 with relatively high, 1 with moderate, and 1 with minimal surface
expression of alphavbeta6 integrin. In addition to alphavbeta6, all 3 cell lines
expressed alpha5beta1 and alphavbeta1 fibronectin receptor integrins. Function
blocking experiments with inhibitory anti-integrin antibodies showed that all
these three integrins were functional in SCC cell spreading on fibronectin.
Integrin alphavbeta6, however, was not used as a primary but as an alternative
fibronectin receptor by SCC cells, as the inhibitory anti-beta6 integrin antibody
alone had no effect on spreading. In migration, however, alphavbeta6,
alpha5beta1, and alphavbeta1 integrins were all used in cooperation. The presence
of alphavbeta1 integrin in SCC cells is a novel finding as is its contribution to
SCC cell migration. When one or two of these three receptors were blocked, the
cells demonstrated an adaptive ability to remain migratory using integrins that
were not targeted by antibodies. Utilization of a combination of receptors of
different affinities may be beneficial for SCC cell migration versatility.
PMID- 10666330
TI - Ceramide-induced apoptosis in fas-resistant Hodgkin's disease cell lines is
caspase independent.
AB - We investigated whether cell-permeable, synthetic ceramide (C6 ceramide) could
induce apoptosis in Fas-resistant Hodgkin's disease (HD)-derived cell lines.
Despite strongly expressing the Fas-receptor, two of three HD-derived cell lines
were resistant to Fas-mediated apoptosis. This resistance to Fas could not be
attributed to differential Fas isoform generation patterns between the Fas
resistant and the Fas-sensitive cell lines. The Fas-resistant cell lines did not
demonstrate the presence of Fas exon 8 deletion. Bcl-2 and BclxL levels were
comparable between the Fas-resistant and the Fas-sensitive cell lines. C6
ceramide could induce apoptosis in both Fas-resistant cell lines and this was
associated with a decrease in BclxL level. Caspase-1, caspase-3, or pan-caspase
inhibitors could not prevent ceramide-induced apoptosis. Furthur, ceramide
treatment did not lead to cleavage of caspase 3 or poly(ADP-ribose) polymerase,
but caused a loss in mitochondrial transmembrane potential which could not be
prevented by caspase inhibitors. Thus, we conclude that ceramide-induced
apoptosis in Fas-resistant HD cell lines is caspase independent.
PMID- 10666331
TI - Detection of apoptosis induced by topoisomerase inhibitors and serum deprivation
in syrian hamster embryo cells.
AB - The sensitivity of normal diploid Syrian hamster embryo (SHE) cells to apoptosis
was tested after treatment with the topoisomerase inhibitors camptothecin and
etoposide and after serum withdrawal. Programmed cell death (PCD) was identified
through morphological, biochemical, and molecular changes and compared with that
of HL60 cell line. The results showed that topoisomerase inhibitors, which were
shown to be potent PCD inducers in the HL60 cell line, induced a weaker apoptotic
response in SHE cells than after growth factor deprivation. In addition, serum
free medium, which rapidly induced apoptosis in SHE cells, did not affect the
HL60 cell line. In both cell types, PCD was expressed by condensed chromatin,
fragmented nuclei, and DNA laddering on electrophoretic gels, an indisputable
sign of apoptosis. In apoptotic HL60 cells, the cleavage of 113-kDa poly(ADP
ribose)polymerase (PARP) resulted in the so-called apoptotic 89-kDa fragment and
was associated with increased caspase-3 activity. In apoptotic SHE cells, PARP
degraded early but the degradation profile was not characterized by the
appearance of an 89-kDa fragment. Moreover, no activation of caspase-3 was noted.
ZnCl(2), which is known to prevent protease activity responsible for apoptosis
features, inhibited PARP cleavage and nuclear modifications induced by apoptotic
stimuli in both cell types, but with a higher sensitivity in SHE cells. Apoptosis
induced by serum deprivation was linked with c-myc negative regulation in SHE
cells, but not with p53 protein accumulation, while topoisomerase inhibitors led
to p53 stabilization without any change in c-myc expression. Serum-free medium
and topoisomerase inhibitors did not modify c-myc expression in the HL60 cell
line. The overall results demonstrated that apoptosis, which is a carefully
regulated process of cell death, may proceed through mechanisms varying according
to cell type or apoptosis inducer. In addition, markers which are generally
considered hallmarks of apoptosis may fail to appear in some cell types.
PMID- 10666332
TI - Gap-junctional coupling measured by flow cytometry.
AB - A method is described which reliably quantifies the degree of intercellular
communication via gap junctions by combining a dye-loading technique with
fluorescence-activated flow cytometry. Our experiments expand former measurements
of other groups by analyzing the time- and density-dependent onset of coupling
with a fixed ratio of donor to recipient cells. The high sensitivity of this
technique provides a better resolution than the microelectrode technique and
allows the detection of small changes in gap-junctional coupling by examining a
large number of cells in a single experiment. Suspended cells were loaded with
the membrane-permeable dye calcein AM, which is intracellularly hydrolyzed by
nonspecific esterases, and the resulting polyanionic calcein is thus trapped
inside these donor cells. Gap junctions, however, are permeable for this
fluorescent dye, as can be observed when suspended donor cells are added to
recipient cells (i.e., monolayer cultures) in which case cell-cell contact is
established within less than 60 min. In addition, one of these two cell
populations can also be stained with a membrane-resident dye (e.g., DiI), which
facilitates the identification of different cell populations (donors, recipients,
and noncoupled cells) not only by epifluorescence microscopy but also by flow
cytometry. Our analyses reveal that junctional coupling depends not only on the
connexin type (homo- or heterotypic junction) but also on the origin (species) of
the contacting cells (homo- or heterospecific contact). We confirm earlier
reports in which homotypic-homospecific coupling was demonstrated with different
techniques in connexin-transfected HeLa and RIN cells as well as in BICR/M1R(k)
and 3T3/SV40 cells. In contrast to other publications, we show that a significant
heterotypic-homospecific coupling between Cx40- and Cx43-HeLa transfectants can
be resolved, whereas no coupling was detected for heterotypic-heterospecific
contacts between Cx40-HeLa transfectants and the Cx43-expressing cell lines
BICR/M1R(k), 3T3/SV40, and RIN.
PMID- 10666333
TI - Expression of the adenovirus receptor and its interaction with the fiber knob.
AB - The coxsackievirus group B (CVB) and adenovirus (Ad) receptor (HCVADR, formerly
HCAR) is a cell surface protein with two immunoglobulin-like regions (IG1 and
IG2) that serves as a receptor for two structurally unrelated viruses. We have
established the tissue distribution of the receptor in the rodent by
immunohistochemistry and show that the receptor is broadly expressed during
embryonic development in the central and peripheral nervous systems and in
several types of epithelial cells. The tissue distribution is more restricted in
the adult but remains high mainly in epithelial cells. Using site-directed
mutagenesis, based on computer modeling of the IG1 region, Ad5 binding could be
inhibited but CVB attachment was unaffected. A double amino acid substitution in
a three-stranded anti-parallel beta sheet that may form a face of the receptor
completely inhibited Ad5 binding. Therefore, we conclude that the molecular
interactions critical for Ad5 binding to HCVADR do not overlap with those of
CVB3. In fact a specific antibody interfering with only CVB binding recognizes
the IG2 domain in the receptor, suggesting that the CVB interacts with this
region or an overlap between the IG1 and the IG2 regions.
PMID- 10666334
TI - NPC1-containing compartment of human granulosa-lutein cells: a role in the
intracellular trafficking of cholesterol supporting steroidogenesis.
AB - Steroidogenic cells represent unique systems for the exploration of intracellular
cholesterol trafficking. We employed cytochemical and biochemical methods to
explore the expression, regulation, and function of the Niemann-Pick C1 protein
(NPC1) in human granulosa-lutein cells. NPC1 was localized in a subset of
lysosome-associated membrane glycoprotein 2 (LAMP-2)-positive vesicles. By
analyzing the sensitivity of NPC1 N-linked oligosaccharide chains to glycosidases
and neuraminidase, evidence was obtained for movement of nascent NPC1 from the
endoplasmic reticulum through the medial and trans compartments of the Golgi
apparatus prior to its appearance in cytoplasmic vesicles. NPC1 protein content
and the morphology and cellular distribution of NPC1-containing vesicles were not
affected by treatment of the granulosa-lutein cells with 8-Br-cAMP, which
stimulates cholesterol metabolism into progesterone. In contrast, steroidogenic
acute regulatory (StAR) protein levels were increased by 8-Br-cAMP. Incubation of
granulosa-lutein cells with low-density lipoprotein (LDL) in the presence of the
hydrophobic amine, U18666A, caused accumulation of free cholesterol in granules,
identified by filipin staining, that contained LAMP-2 and NPC1. These granules
also stained for neutral lipid with Nile red, reflecting accumulation of LDL
derived cholesterol esters. LDL-stimulated progesterone synthesis was completely
blocked by U18666A, leaving steroid output at levels similar to those of cells
incubated in the absence of LDL. The hydrophobic amine also blocked the LDL
augmentation of 8-Br-cAMP-stimulated progesterone synthesis, reducing steroid
production to levels seen in cells stimulated with 8-Br-cAMP in the absence of
LDL. Steroidogenesis recovered after U18666A was removed from the culture medium.
U18666A treatment caused a 2-fold or more increase in NPC1 protein and mRNA
levels, suggesting that disruption of NPC1's function activates a compensatory
mechanism resulting in increased NPC1 synthesis. We conclude that the NPC1
compartment plays an important role in the trafficking of LDL-derived substrate
in steroidogenic cells; that NPC1 expression is up-regulated when NPC1 action is
blocked; and that the NPC1 compartment can be functionally separated from other
intracellular pathways contributing substrate for steroidogenesis.
PMID- 10666335
TI - Surfactant protein A regulates pulmonary surfactant secretion via activation of
phosphatidylinositol 3-kinase in type II alveolar cells.
AB - Pulmonary surfactant is secreted by the type II alveolar cells of the lung, and
this secretion is induced by secretagogues of several types (e.g., ionomycin,
phorbol esters, and terbutaline). Secretagogue-induced secretion is inhibited by
surfactant-associated protein A (SP-A), which binds to a specific receptor (SPAR)
on the surface of type II cells. The mechanism of SP-A-activated SPAR signaling
is completely unknown. The phosphatidylinositol 3-kinase (PI3K) inhibitor
LY294002 rescued surfactant secretion from inhibition by SP-A. In order to
directly demonstrate a role for PI3K in SPAR signaling, PI3K activity was
immunoprecipitated from type II cell extracts. PI3K activity increased rapidly
after SP-A addition to type II cells. Since many receptors that activate PI3K do
so through tyrosine-specific protein phosphorylation, antisera to
phosphotyrosine, insulin-receptor substrate-1 (IRS-1), or SPAR were also
examined. These antisera coimmunoprecipitated PI3K activity that was stimulated
by SP-A. In addition, the tyrosine-specific protein kinase inhibitors genistein
and herbimycin A blocked the action of SP-A on surfactant secretion. We conclude
that SP-A signals to regulate surfactant secretion through SPAR, via pathways
that involve tyrosine phosphorylation, include IRS-1, and entail activation of
PI3K. This activation leads to inhibition of secretagogue-induced secretion of
pulmonary surfactant.
PMID- 10666336
TI - Increased TGFbeta type II receptor expression suppresses the malignant phenotype
and induces differentiation of human neuroblastoma cells.
AB - TGFbeta can modulate neuroblastoma (NB) cell proliferation and differentiation in
vitro. In this study we used a NB cell line (LAN-5) which has been shown to
partially respond to TGFbeta and to present high levels of TGFbeta receptor type
I and low levels of receptor type II (TbetaRII) on the cell surface. To evaluate
the role of TbetaRII in mediating TGFbeta effects, LAN-5 cells were transfected
with an expression vector containing the human full-length TbetaRII cDNA or with
the empty vector pcDNA3. Compared to control CLV3 cells (transfected with empty
plasmid) and parental LAN-5 cells, isolated neomycin-resistant clones (CL1 and
CL3) expressed higher levels of TbetaRII, had reduced cell growth rate in vitro,
and were unable to form tumors in vivo. Furthermore, isolated clones modified
their morphology, assuming a terminally differentiated neuronal phenotype.
Immunocytochemical staining demonstrated a basal increased expression of neural
specific markers, such as axonal growth-associated protein (GAP43) and
neurofilaments (NF200). TGFbeta treatment further increased the synthesis of
NF200 and GAP43 in the transfected clones as revealed by Western blot analysis.
These data indicate that TbetaRII overexpression potentiates the TGFbeta signal
transduction pathway, reverting NB cell neoplastic phenotype with the reduction
of proliferation rate and the induction of terminal maturation.
PMID- 10666338
TI - Telomere shortening by cisplatin in yeast nucleotide excision repair mutant.
AB - Telomeres are unique DNA tandem repeats that form the ends of eukaryotic
chromosomes to protect the chromosomes from degradation and illegitimate
recombination. In yeast, loss of telomere may be compensated for through the
acquisition of new telomere by RAD52-mediated or RAD52-independent
recombinational repair. In this report, the effects of cis-dichlorodiammine
platinum (II) (cisplatin) on telomere length and the role of nucleotide excision
repair in telomere maintenance were examined in the yeast Saccharomyces
cerevisiae. We showed that the SSL2 (RAD25) DNA repair yeast mutant exhibited a
gradual shortening of the telomere in the presence of cisplatin. Further telomere
shortening was prevented upon the withdrawal of cisplatin. Complementation of the
mutant with the wild-type SSL2 (RAD25) gene abolished the cisplatin-induced
telomere degradation. These results suggest that telomeres are susceptible to
cisplatin-induced intrastrand crosslinks and that Ssl2 (Rad25) or the nucleotide
excision repair pathway may play a critical role in the repair and the
maintenance of telomere integrity.
PMID- 10666337
TI - Human topoisomerase IIalpha and IIbeta interact with the C-terminal region of
p53.
AB - The p53 tumor suppressor protein is a critical regulator of cell cycle
progression and apoptosis following exposure of cells to DNA damaging agents such
as ionizing radiation or anticancer drugs. An important group of anticancer
drugs, including compounds such as etoposide and doxorubicin (Adriamycin),
interacts with DNA topoisomerase II (topo II), causing the accumulation of enzyme
DNA adducts that ultimately lead to double-strand breaks and cell death via
apoptosis. Human topo IIbeta has previously been shown to interact with p53, and
we have extended this analysis to show that both topo IIalpha and IIbeta interact
with p53 in vivo and in vitro. Furthermore, we show that the regulatory C
terminal basic region of p53 (residues 364-393) is necessary and sufficient for
interaction with DNA topo II.
PMID- 10666339
TI - The carboxy terminus of AFAP-110 modulates direct interactions with actin
filaments and regulates its ability to alter actin filament integrity and induce
lamellipodia formation.
AB - The actin filament-associated protein AFAP-110 is an SH2/SH3 binding partner for
Src. AFAP-110 contains several protein-binding motifs in its amino terminus and
has been hypothesized to function as an adaptor molecule that could link
signaling proteins to actin filaments. Recent studies using deletional
mutagenesis demonstrated that AFAP-110 can alter actin filament integrity in SV40
transformed Cos-1 cells. Thus, AFAP-110 may be positioned to modulate the effects
of Src upon actin filaments. In this report, we sought to determine whether (a)
AFAP-110 could interact with actin filaments directly and (b) deletion mutants
could affect actin filament integrity and cell shape in untransformed fibroblast
cells. The data demonstrate that the carboxy terminus of AFAP-110 is both
necessary and sufficient for actin filament association, in vivo and in vitro.
Analysis of the carboxy terminus revealed a mean 40% similarity with other known
actin-binding motifs, indicating a mechanism for binding to actin filaments. AFAP
110 can also induce lamellipodia formation. Contiguous with the alpha-helical,
actin-binding motif is an alpha-helical, leucine zipper motif. Deletion of the
leucine zipper motif (AFAP(Deltalzip)) followed by cellular expression enabled
AFAP(Deltalzip) to alter actin filament integrity and cell shape in untransformed
cells as evidenced by the induction of lamellipodia formation. We hypothesize
that AFAP-110 may be an important signaling protein that can directly modulate
changes in actin filament integrity and induce lamellipodia formation.
PMID- 10666340
TI - Spermatogenesis in mice is not affected by histone H1.1 deficiency.
AB - The linker histone subtype H1.1 belongs to the group of main-type histones and is
synthesized in somatic tissues as well as in germ cells during the S phase of the
cell cycle. In adult mice the histone gene H1.1 is expressed mainly in thymus,
spleen, and testis. The single-copy gene coding for the H1.1 protein was
eliminated by homologous recombination in mouse embryonic stem cells. Mice
homozygous for the deficient H1.1 gene developed normally until the adult stage
without H1.1 mRNA and H1.1 protein. No anatomic abnormalities could be detected.
In addition, mice lacking the H1.1 gene were fertile and they showed normal
spermatogenesis and testicular morphology.
PMID- 10666341
TI - Cleavage of Poly(ADP-ribose) polymerase measured in situ in individual cells:
relationship to DNA fragmentation and cell cycle position during apoptosis.
AB - Poly(ADP-ribose) polymerase (PARP), a nuclear enzyme involved in DNA repair, is a
target of caspases during apoptosis: its cleavage onto 89- and 24-kDa fragments
is considered to be a hallmark of the apoptotic mode of cell death. Another
hallmark is the activation of endonuclease which targets internucleosomal DNA.
The aim of the present study was to reveal cell cycle phase specificity as well
as the temporal and sequence relationships of PARP cleavage vis-a-vis DNA
fragmentation in two model systems of apoptosis, one induced by DNA damage via
cell treatment with camptothecin (CPT) (mitochondria-induced pathway) and another
by the cytotoxic ligand tumor necrosis factor alpha (TNF-alpha) (cell surface
death receptor pathway). PARP cleavage was detected immunocytochemically using
antibody which recognizes its 89-kDa fragment (PARP p89) while DNA fragmentation
was assayed by in situ labeling of DNA strand breaks. The frequency and extent of
PARP cleavage as well as DNA fragmentation were measured by mutiparameter flow
and laser scanning cytometry. PARP cleavage, selective to S phase cells, was
detected 90 min after administration of CPT. PARP cleavage in the cells treated
with TNF-alpha was not selective to any cell cycle phase and was seen already
after 30 min. DNA fragmentation trailed PARP cleavage by about 30 min and showed
a similar pattern of cell cycle specificity. PARP p89 was present in nuclear
chromatin but at least in the early phase of apoptosis it did not colocalize with
DNA strand breaks. The rate of cleavage of PARP molecules in individual cells
whether induced by CPT or TNF-alpha was rapid as reflected by the paucity of
cells with a mixture of cleaved and noncleaved PARP molecules. In contrast, DNA
fragmentation proceeded stepwise before reaching the maximal number of DNA strand
breaks. Although time windows for PARP cleavage vs DNA fragmentation were
different at early stages of apoptosis, a good overall correlation between the
cytometric assays of apoptotic cells identification based on these events was
observed in both CPT- and TNF-alpha-treated cultures.
PMID- 10666342
TI - International differences: selection, noise, or real?
PMID- 10666343
TI - Aortic stiffness: a predictor of acute coronary events?
PMID- 10666344
TI - Early risk-stratification in patients with angina but non-diagnostic ECG.
PMID- 10666345
TI - Cerebral hypoperfusion and impaired cerebral function in cardiac failure.
PMID- 10666346
TI - Triage of chest pain patients based on early risk stratification using sensitive
cardiac markers.
PMID- 10666347
TI - Assessment of coronary heart disease risk in populations with different levels of
risk.
PMID- 10666348
TI - Athletic left ventricular hypertrophy: long-term studies are required.
PMID- 10666349
TI - Beta-blockers continue to surprise us.
PMID- 10666350
TI - Comparison of the Framingham risk function-based coronary chart with risk
function from an Italian population study.
AB - AIMS: The aim is to compare the coronary risk chart published by the European
Task Force for Prevention of Coronary Heart Disease and produced using a
Framingham risk function, with a risk function derived from an Italian population
study. METHODS AND RESULTS: Coronary risk function in this study was the result
of longitudinal experience in an Italian middle-aged population of 1656 male
subjects followed-up for 25 years. To comply with the Framingham equation the
same risk factors (age, systolic blood pressure, total serum cholesterol and
smoking habits), end-points (any possible coronary event including angina
pectoris), and length of follow-up (10 years) were used, and the model (log
linear accelerated time failure model, accommodating the Weibull distribution)
was similar. Comparisons were made computing the coronary risk for each cell of
the coronary risk chart for men aged 40, 50 and 60 years. The Italian risk
function produced highly significant coefficients for all four risk factors.
Forty-four out of a total of 120 cells had a coronary risk of 20% or more in 10
years following the coronary risk chart, whereas this was reduced to four while
using the Italian risk function (P<0.001). The Italian risk function largely
underestimated the corresponding levels produced by the coronary risk chart and
vice versa. CONCLUSION: The Framingham risk function-based coronary risk chart
overestimates absolute coronary risk in countries characterized by a lower
incidence of coronary events and should be used with caution.
PMID- 10666351
TI - Geographic variability in outcomes within an international trial of glycoprotein
IIb/IIIa inhibition in patients with acute coronary syndromes. Results from
PURSUIT.
AB - AIMS: Variations in outcome of patients from different geographic regions have
been observed in many large international trials. We analysed the factors that
might contribute to the geographic variations in patient outcome and treatment
effect as observed in the PURSUIT trial. METHODS: In PURSUIT, 9461 patients with
acute coronary syndromes without persistent ST-elevation were randomized to the
platelet inhibitor eptifibatide or placebo for 72 h in 27 countries in four
geographic regions: Western (n=3697) and Eastern Europe (n=1541) as well as North
(n=3827) and Latin America (n=396). The primary end-point was the 30-day
composite of death or myocardial infarction. In the initial univariate analysis,
the treatment effect appeared greater in N. America than in W. Europe, while no
benefit was apparent in L. America and E. Europe. However, the confidence
intervals were wide and overlapping. To study these differences, a subdivision in
an early and late patient outcome and treatment effect was made. Accordingly, we
analysed the rate of death or infarction at 72 h censored for percutaneous
coronary intervention and the rate between 3 and 30 days, respectively.
Additional analyses were performed with different definitions of myocardial
infarction using progressively higher thresholds of CK(-MB) elevation.
Multivariable analysis was used to evaluate the relation between region and
outcome and to determine the adjusted odds ratios for the eptifibatide treatment
effect. RESULTS: Major differences in baseline demographics were apparent among
the four regions; in particular, more patients from E. Europe had characteristics
associated with impaired outcome. Interventional treatment also varied
considerably, with more patients from N. America undergoing revascularization.
Despite differences in the 72 h event rate, eptifibatide showed a consistent
trend towards a reduction in the composite end-point among all four regions and
for all definitions of infarction. Relative reductions ranged from 17-42% in W.
Europe, 23-35% in N. America, 0-33% in E. Europe, and 55-82% in L. America. After
multivariable adjustment, the pattern of benefit with eptifibatide was consistent
among the regions. In patients undergoing percutaneous coronary intervention
during study drug infusion in W. Europe (n=266) and N. America (n=931), the
relative reduction in myocardial infarction during medical therapy ranged from 56
75% in W. Europe and 14-67% in N. America, while the reduction in procedure
related events ranged from 12-44% and 25-61% for different definitions of
infarction. After multivariable adjustment neither benefit nor rebound were
apparent after study drug discontinuation, or after 3 days in all regions, except
in L. America. In general, the differences in outcome and treatment effect were
greatest when the protocol definition of myocardial infarction (CK(-MB) >1 upper
normal limit) was applied. Under stricter definitions, these differences became
smaller and disappeared with the investigator's assessment. CONCLUSION: The
analysis suggests that the apparent differences in patient outcome and
eptifibatide treatment effect can be explained largely by differences in baseline
demographics and adjunctive treatment strategies as well as by the methodology of
myocardial infarction definition and the adjudication process.
PMID- 10666352
TI - Very early diagnosis and risk stratification of patients admitted with suspected
acute myocardial infarction by the combined evaluation of a single serum value of
cardiac troponin-T, myoglobin, and creatine kinase MB(mass)
AB - AIMS: The diagnostic and prognostic capacity of biochemical markers of acute
myocardial infarction in the emergency department were evaluated in consecutive
patients (n=155) with suspected acute myocardial infarction. METHODS AND RESULTS:
Serum myoglobin >/=110 microg. l(-1)and creatine kinase MB(mass)>/=5 microg. l(
1)had a high accuracy (0.77-0.85) (ns) for acute myocardial infarction diagnosis
in patients presenting >2 h after symptom onset. Troponin-T (>/=0.10 microg. l(
1)) had a lower accuracy (0.53-0.70) for acute myocardial infarction diagnosis,
but was the most important 1-year prognostic marker (cardiac death or non-fatal
acute myocardial infarction). In patients without ST elevation, combined analysis
of two biochemical tests would accurately identify an additional 20% of acute
myocardial infarction patients (predictive value of a positive test=0.82) and
also identify those without acute myocardial infarction (predictive value of a
negative test=0.80). One-year event-free survival was excellent (96%) for
patients with two negative biochemical tests, intermediate (74%) for those with
discordant tests, and only 53% for patients with two positive biochemical tests.
CONCLUSIONS: Analysis of biochemical tests in the emergency department prior to
hospital admission could accurately identify approximately 20% additional acute
myocardial infarction patients. The prognosis of these patients is poor, and they
may be a target for primary PTCA or new early initiated aggressive medical
therapies.
PMID- 10666353
TI - Aortic stiffness as a risk factor for recurrent acute coronary events in patients
with ischaemic heart disease.
AB - AIMS: Aortic elasticity is an important determinant of left ventricular
performance and coronary blood flow. Moreover, it has been shown that aortic
elastic properties deteriorate in patients with coronary artery disease. However,
the predictive role of aortic elasticity in the occurrence of coronary events,
has not been addressed so far. Therefore, we set out to test prospectively the
hypothesis that invasive as well as non-invasive measures of aortic elastic
properties, assessed at rest from pressure-diameter relationships, could predict
the development of recurrent coronary events. METHODS AND RESULTS: Clinical
variables and measures of aortic function were assessed in 54 normotensive
patients with coronary artery disease. The aortic pressure-diameter relationship
was derived invasively with a high-fidelity Y shaped catheter (developed in our
Institution) for aortic diameter measurements, simultaneously with a Millar
catheter for aortic pressure measurements. Aortic root distensibility was
assessed by non-invasive techniques. During an average of 3 years follow-up, 12
of 54 patients either developed unstable angina (n=8) or acute myocardial
infarction (n=4). By multivariate Cox model analysis, aortic stiffness was the
strongest predictor of progression to any end-point (relative risk: 3.24, CI:
1.79 to 5.83;P=0.000). When aortic stiffness was not considered, aortic
distensibility was the only independent predictor for acute coronary syndromes
(relative risk: 0.37 CI: 0.21 to 0.65;P=0.000). CONCLUSION: In patients with
coronary artery disease, aortic elastic properties are powerful and independent
risk factors for recurrent acute coronary events.
PMID- 10666354
TI - Safety and prognostic value of early dobutamine-atropine stress echocardiography
in patients with spontaneous chest pain and a non-diagnostic electrocardiogram.
AB - AIMS: To risk stratify and shorten hospital stay in patients with spontaneous
(resting) chest pain and a non-diagnostic electrocardiogram (ECG). METHODS AND
RESULTS: The study comprised 102 patients (mean age 58+/-12 years, 67 men) with
spontaneous chest pain and a non-diagnostic ECG. Forty-three patients had
suspected coronary artery disease and 59 had known (but of unknown actual
significance) coronary artery disease. All patients underwent serial creatine
kinase enzyme measurements, continuous ECG monitoring for at least 12 h and early
dobutamine-atropine stress echocardiography in patients with negative creatine
kinase enzymes and normal findings at ECG monitoring. Dobutamine-atropine stress
echocardiography was considered positive in patients with new or worsening wall
thickening abnormalities. Patients with negative dobutamine-atropine stress
echocardiography were discharged after the test. In-hospital and 6 month follow
up events noted were cardiac death, non-fatal myocardial infarction, unstable
angina, and coronary artery bypass surgery or angioplasty. Thirteen patients had
evidence of evolving myocardial infarction by elevated creatine kinase enzymes,
or unstable angina by ECG monitoring. In the remaining 89 patients, dobutamine
atropine stress echocardiography was performed after a median observation period
of 31 h (range 12-68 h). During dobutamine-atropine stress echocardiography no
serious complications (death, non-fatal myocardial infarction, sustained
ventricular tachycardia or ventricular fibrillation) occurred. Dobutamine
atropine stress echocardiography results were of poor quality in three, non
diagnostic in six, negative in 44 and positive in 36 patients. In the 80 patients
with diagnostic dobutamine-atropine stress echocardiography, variables associated
with in-hospital events (n=7) were history of exertional angina (P<0. 005), chest
pain score (P<0.005), stress-induced angina (P<0.001) and positive dobutamine
atropine stress echocardiography (P<0.005). Variables associated with follow-up
events (n=11) were history of exertional angina (P<0.05), chest pain score
(P<0.001), stress-induced angina (P<0.01) and positive dobutamine-atropine stress
echocardiography (P<0.01). At multivariate analysis the only significant
predictor of events was positive dobutamine-atropine stress echocardiography
(P<0.01). CONCLUSION: Early dobutamine-atropine stress echocardiography may
safely distinguish between low- and high-risk subsets for subsequent cardiac
events in patients with spontaneous chest pain and a non-diagnostic ECG.
PMID- 10666355
TI - Cerebrovascular reactivity is impaired in patients with cardiac failure.
AB - AIMS: We undertook this study to evaluate potential changes in cerebral
vasoreactivity in patients with cardiac failure and their consequent dependence
upon cardiac functional variables. METHODS AND RESULTS: A total of 50 patients
with various degrees of heart failure, 20 age-matched controls and 20 normal
controls were examined. Cerebrovascular reactivity was examined with the carbon
dioxide technique. Mean flow velocities of both middle cerebral arteries as well
as end-tidal carbon dioxide partial pressure were continuously registered. Normal
controls were examined on two different occasions, to evaluate the technique's
reproducibility. Cerebrovascular reactivity was significantly reduced in all
examined patients as compared to controls, and in NYHA IV as compared to NYHA II
and III patients. A significant relationship between cerebrovascular reactivity
and left ventricular ejection fraction was evident. Reproducibility of the
technique was satisfactory. CONCLUSION: Our study provided evidence of
significantly reduced cerebrovascular reactivity in patients with cardiac
failure, which was significantly related to the NYHA grade and the left
ventricular ejection fraction.
PMID- 10666357
TI - ESC news and appointments
PMID- 10666356
TI - Blood pressure awareness in Austria. A 20-year evaluation, 1978-1998.
AB - AIM: To evaluate public awareness following a nationwide educational campaign on
hypertension. METHODS AND RESULTS: In 1978 the Austrian Heart Foundation
conducted a nationwide educational campaign to increase the awareness of the
population regarding the importance of recognizing and treating high blood
pressure. Following this campaign, five opinion polls of random and
representative samples were conducted to measure the awareness and knowledge of
the population relating to issues of high blood pressure. The poll results
indicated that during the period immediately following the awareness campaign,
knowledge and perception of the dangers of high blood pressure increased.
However, this effect dissipated during subsequent years. In 1978, 14% of the
population were reported to be hypertensive and 10% had no relevant information
about their blood pressure status. In 1998, those who labelled themselves as
hypertensive dropped to 12%, while those who did not know their blood pressure
values, increased to 14%. The percentage of the population who recalled having
their blood pressure measured during the last 3 months dropped from 49% in 1978,
to 34% in 1993, and remained at 34% in 1998. CONCLUSION: We conclude that the
intensive blood pressure education campaign had only a temporary effect on
improving blood pressure awareness. Improved strategies are needed to achieve
better community control of hypertension.
PMID- 10666358
TI - Autoregressive models for estimating phylogenetic and environmental effects:
accounting for within-species variations.
AB - Comparative methods are used to investigate the attributes of present species or
higher taxa. Difficulties arise from the phylogenetic heritage: taxa are not
independent and neglecting phylogenetic inertia can lead to inaccurate results.
Within-species variations in life-history traits are also not negligible, but
most comparative methods are not designed to take them into account. Taxa are
generally described by a single value for each trait. We have developed a new
model which permits the incorporation of both the phylogenetic relationships
among populations and within-species variations. This is an extension of
classical autoregressive models. This family of models was used to study the
effect of fishing on six demographic traits measured on 77 populations of teleost
fishes.
PMID- 10666359
TI - Stochastic variation in food availability influences weight and age at maturity.
AB - Variation in mean food availability, and in the variance around the mean, affects
the growth rate during development. Previous theoretical work on the influence of
environmental quality or growth rates on the phenotypic traits age and size at
maturation assumed that there is no variation in growth rate or food availability
within a generation. We develop a stochastic dynamic programming (SDP) model of
the foraging behaviour of aphidophagous syrphids, and use this model to predict
when syrphids should pupate (mature) when average food availability changes, or
varies stochastically, during development. The optimal strategy takes into
account not only the availability of food, but also the timing of its
availability. Food availability, when small, influences developmental time, but
not weight at pupation. Food availability, when large, influences weight at
pupation, but not developmental time. When the food supply is low, the optimal
strategy adjusts the size at pupation downwards for stochastic as opposed to
deterministic availability of food. The conclusions reinforce the need for life
history studies to consider state dependence and short-term variability in growth
rates.
PMID- 10666360
TI - Distributions of dimeric tandem repeats in non-coding and coding DNA sequences.
AB - We study the length distribution functions for the 16 possible distinct dimeric
tandem repeats in DNA sequences of diverse taxonomic partitions of GenBank (known
human and mouse genomes, and complete genomes of Caenorhabditis elegans and
yeast). For coding DNA, we find that all 16 distribution functions are
exponential. For non-coding DNA, the distribution functions for most of the
dimeric repeats have surprisingly long tails, that fit a power-law function. We
hypothesize that: (i) the exponential distributions of dimeric repeats in protein
coding sequences indicate strong evolutionary pressure against tandem repeat
expansion in coding DNA sequences; and (ii) long tails in the distributions of
dimers in non-coding DNA may be a result of various mutational mechanisms. These
long, non-exponential tails in the distribution of dimeric repeats in non-coding
DNA are hypothesized to be due to the higher tolerance of non-coding DNA to
mutations. By comparing genomes of various phylogenetic types of organisms, we
find that the shapes of the distributions are not universal, but rather depend on
the specific class of species and the type of a dimer.
PMID- 10666361
TI - Specific and non-specific defense against parasitic attack.
AB - Specific defense protects against some parasite genotypes but not others, whereas
non-specific defense is effective against all genotypes of a parasite. Some
empirical studies observe hosts with variability only in non-specific defense,
other studies find only specific defense. I analyse a model with combined
specific and non-specific defense to determine the conditions that favor
detectable variation in each form of defense. High variation in non-specific
defense is often maintained when resistance increases in an accelerating way with
investment, whereas low variation tends to occur when resistance increases at a
decelerating rate with investment. Variation in specific defense rises as the
parasite pays a higher cost to attack a broad host range (high cost of
virulence), as the number of alternative specificities declines, and as the
average level of non-specific defense increases. The last condition occurs
because greater non-specific protection tends to stabilize the gene frequency
dynamics of specific defense. Selection favors a negative association between
costly components of specific and non-specific defense-hosts defended by one
component are favored if they have reduced allocation to other costly components.
A negative association confounds the measurement of costs of resistance.
Individuals with specific defense may have reduced investment in costly non
specific defense. This leads to an apparent advantage of specifically defended
hosts in the absence of parasites and a measured cost of resistance that is
negative.
PMID- 10666362
TI - Is there replication-associated mutational pressure in the Saccharomyces
cerevisiae genome?
AB - Compositional bias of yeast chromosomes was analysed using detrended DNA walks.
Unlike eubacterial chromosomes, the yeast chromosomes did not show the specific
asymmetry correlated with origin and terminus of replication. It is probably a
result of a relative excess of autonomously replicating sequences (ARS) and of
random choice of these sequences in each replication cycle. Nevertheless, the
last ARS from both ends of chromosomes are responsible for unidirectional
replication of subtelomeric sequences with pre-established leading/lagging roles
of DNA strands. In these sequences a specific asymmetry is observed, resembling
the asymmetry introduced by replication-associated mutational pressure into
eubacterial chromosomes.
PMID- 10666363
TI - Vasculogenic mimicry in tumors. Fact or artifact?
PMID- 10666365
TI - Vasculogenic mimicry: how convincing, how novel, and how significant?
PMID- 10666364
TI - Vasculogenic mimicry and tumor angiogenesis.
AB - Tumors require a blood supply for growth and hematogenous dissemination. Much
attention has been focused on the role of angiogenesis-the recruitment of new
vessels into a tumor from pre-existing vessels. However, angiogenesis may not be
the only mechanism by which tumors acquire a microcirculation. Highly aggressive
and metastatic melanoma cells are capable of forming highly patterned vascular
channels in vitro that are composed of a basement membrane that stains positive
with the periodic acid-Schiff (PAS) reagent in the absence of endothelial cells
and fibroblasts. These channels formed in vitro are identical morphologically to
PAS-positive channels in histological preparations from highly aggressive primary
uveal melanomas, in the vertical growth phase of cutaneous melanomas, and in
metastatic uveal and cutaneous melanoma. The generation of microvascular channels
by genetically deregulated, aggressive tumor cells was termed "vasculogenic
mimicry" to emphasize their de novo generation without participation by
endothelial cells and independent of angiogenesis. Techniques designed to
identify the tumor microcirculation by the staining of endothelial cells may not
be applicable to tumors that express vasculogenic mimicry. Although it is not
known if therapeutic strategies targeting endothelial cells will be effective in
tumors whose blood supply is formed by tumor cells in the absence of
angiogenesis, the biomechanical and molecular events that regulate vasculogenic
mimicry provide opportunities for the development of novel forms of tumor
targeted treatments. The unique patterning characteristic of vasculogenic mimicry
provides an opportunity to design noninvasive imaging techniques to detect highly
aggressive neoplasms and their metastases.
PMID- 10666366
TI - Differential growth: from carcinogenesis to liver repopulation.
PMID- 10666367
TI - Control of apoptosis during angiogenesis by survivin expression in endothelial
cells.
AB - Mechanisms controlling endothelial cell survival during angiogenesis were
investigated. Stimulation of quiescent endothelial cells with mitogens, including
vascular endothelial growth factor and basic fibroblast growth factor, induced up
to approximately 16-fold up-regulation of the cell cycle-regulated apoptosis
inhibitor survivin. Mitogen stimulation rapidly increased survivin RNA expression
in endothelial cells, which peaked after 6 to 10 hours in culture and decreased
by 24 hours. Inflammatory cytokines, tumor necrosis factor alpha, and interleukin
1 did not induce survivin expression in endothelial cells. Formation of three
dimensional vascular tubes in vitro was associated with strong induction of
survivin in endothelial cells, as compared with two-dimensional cultures. By
immunohistochemistry, survivin was minimally expressed in endothelium of
nonproliferating capillaries of normal skin, whereas it became massively up
regulated in newly formed blood vessels of granulation tissue in vivo.
Recombinant expression of green fluorescent protein survivin in endothelial cells
reduced caspase-3 activity and counteracted apoptosis induced by tumor necrosis
factor alpha/cycloheximide. These findings identify survivin as a novel growth
factor-inducible protective gene expressed by endothelial cells during
angiogenesis. Therapeutic manipulation of survivin expression and function in
endothelium may influence compensatory or pathological (tumor) angiogenesis.
PMID- 10666368
TI - Strong immunostaining for myogenin in rhabdomyosarcoma is significantly
associated with tumors of the alveolar subclass.
AB - Rhabdomyosarcomas are a heterogeneous group of tumors with respect to their
molecular basis, degree of differentiation, histology, and clinical behavior.
Because of the wide variation of tumor morphology, it is often difficult to
distinguish between the distinct subtypes of rhabdomyosarcomas. By using
cryosections of tumor specimens and immunohistochemistry, in the present study we
show that strong expression of myogenin in rhabdomyosarcoma is associated with
alveolar histology (P = <0.0001, Fisher's exact test). Although staining for
myogenin was observed in 22 of 26 rhabdomyosarcomas, all alveolar
rhabdomyosarcomas (nine of nine) showed high levels of staining for myogenin, as
defined by the frequency and intensity of staining of the tumor cells. The
staining pattern suggests that the tumor cells are clonally derived from myogenin
positive progenitor cells. In contrast, most embryonal rhabdomyosarcomas (13 of
15) were either negative or showed a low level of staining for myogenin. In these
tumors a larger proportion of tumor cells were distinctly negative for myogenin.
Six of seven alveolar rhabdomyosarcomas that strongly stained for myogenin were
also positive for Pax3-7/Forkhead (FKHR) by polymerase chain reaction/reverse
transcriptase-polymerase chain reaction. One of two embryonal rhabdomyosarcomas
that strongly stained for myogenin was retrospectively found to be positive for
Pax3/FKHR transcripts. Quantitative analysis for myogenin by Western blotting
using a smaller subset of rhabdomyosarcomas revealed that in general there was a
good correlation between immunohistochemical staining and Western blotting (P =
0.01, Pearson Correlation), although the former technique was more sensitive for
detecting tumors with low levels of the protein. On average, alveolar
rhabdomyosarcomas expressed at least threefold more myogenin than embryonal
rhabdomyosarcomas. Our data show that staining for myogenin will be a simple,
rapid, and accurate adjunct for distinguishing between alveolar and embryonal
rhabdomyosarcomas. We propose that embryonal rhabdomyosarcomas result from an
early block in myogenesis, before the expression of myogenin. In contrast, we
propose that alveolar rhabdomyosarcomas either originate from a late block in
myogenesis (after expression of myogenin) or that the pathological mechanisms
involved in these neoplasms also induce strong expression of this protein.
PMID- 10666369
TI - Bcl-2 and p53 protein expression, apoptosis, and p53 mutation in human epithelial
ovarian cancers.
AB - Bcl-2 and p53 gene products have been both linked to cell death by apoptosis. In
the present study, we examined the relationship of Bcl-2 and p53 protein
expression, p53 mutation and apoptosis in normal human ovaries and different
types of human ovarian epithelial tumors by immunohistochemical localization, in
situ terminal transferase-mediated dUTP nick end labeling and polymerase chain
reaction-single strand conformation polymorphism. It was found that Bcl-2
expressed strongly in the surface epithelium of normal ovaries and benign and
borderline ovarian tumors but weakly in the malignant tumors. On the contrary,
strong protein expression of p53 was found in 54% (25/46) of the malignant
epithelial tumors examined but similar expression of p53 was not observed in
borderline and benign tumors and normal ovarian surface epithelium. A significant
inverse correlation between Bcl-2 and p53 expression was found in the malignant
ovarian tumors examined. p53 gene mutation at exons 5-11 was however not a pre
requisite for p53 expression in both borderline and malignant tumors. Apoptotic
activities, as reflected by apoptotic indices, were low in normal ovarian surface
epithelium and benign tumors but were increased in borderline and malignant
tumors, with the highest average apoptotic index found in grade III malignant
tumors. Statistical analyses showed a positive correlation between apoptosis and
p53 expression, but similar correlation was not found between apoptosis and Bcl-2
expression. Our results also indicate that although expression of Bcl-2 is
important during ovarian carcinogenesis, the Bcl-2 protein may have other roles
to play apart from being a modulator of apoptosis in human ovarian epithelial
cancers.
PMID- 10666370
TI - Loss of FHIT expression in transitional cell carcinoma of the urinary bladder.
AB - Cytogenetic and loss of heterozygosity (LOH) studies demonstrated chromosome 3p
deletions in transitional cell carcinoma (TCC). We recently cloned the tumor
suppressor gene FHIT (fragile histidine triad) at 3p14.2, one of the most
frequently deleted chromosomal regions in TCC of the bladder, and showed that it
is the target of environmental carcinogens. Abnormalities at the FHIT locus have
been found in tumors of the lung, breast, cervix, head and neck, stomach,
pancreas, and clear cell carcinoma of the kidney. We examined six TCC derived
cell lines (SW780, T24, Hs228T, CRL7930, CRL7833, and HTB9) and 30 primary TCC of
the bladder for the integrity of the FHIT transcript, using reverse transcriptase
polymerase chain reaction (RT-PCR) to investigate a potential role of the FHIT
gene in TCC of the bladder. In addition, we tested expression of the Fhit protein
in the six TCC-derived cell lines by Western blot analysis and in 85 specimens of
primary TCCs by immunohistochemistry. Three of the six cell lines (50%) did not
show the wild-type FHIT transcript, and Fhit protein was not detected in four of
the six cell lines (67%) tested. Fhit expression also was correlated with
pathological and clinical status. A significant correlation was observed between
reduced Fhit expression and advanced stage of the tumors. Overall, 26 of 30 (87%)
primary TCCs showed abnormal transcripts. Fhit protein was absent or greatly
reduced in 61% of the TCCs analyzed by immunohistochemistry. These results
suggested that loss of Fhit expression may be as important in the development of
bladder cancer as it is for other neoplasms caused by environmental carcinogens.
PMID- 10666371
TI - Genetic profile of gliosarcomas.
AB - There are distinct genetic pathways leading to the glioblastoma, the most
malignant astrocytic brain tumor. Primary (de novo) glioblastomas develop in
older patients and are characterized by epidermal growth factor (EGF) receptor
amplification/overexpression, p16 deletion, and PTEN mutations, whereas secondary
glioblastomas that progressed from low-grade or anaplastic astrocytoma develop in
younger patients and frequently contain p53 mutations. In this study, we assessed
the genetic profile of gliosarcoma, a rare glioblastoma variant characterized by
a biphasic tissue pattern with alternating areas displaying glial and mesenchymal
differentiation. Single-strand conformation polymorphism followed by direct DNA
sequencing revealed p53 mutations in five of 19 gliosarcomas (26%) and PTEN
mutations in seven cases (37%). Homozygous p16 deletion was detected by
differential polymerase chain reaction in seven (37%) gliosarcomas. The overall
incidence of alterations in the Rb pathway (p16 deletion, CDK4 amplification, or
loss of pRb immunoreactivity) was 53%, and these changes were mutually exclusive.
Coamplification of CDK4 and MDM2 was detected in one gliosarcoma. None of the
gliosarcomas showed amplification or overexpression of the EGF receptor. Thus
gliosarcomas exhibit a genetic profile similar to that of primary (de novo)
glioblastomas, except for the absence of EGFR amplification/overexpression.
Identical PTEN mutations in the gliomatous and sarcomatous tumor components were
found in two cases. Other biopsies contained p16 deletions, an identical p53
mutation, or coamplification of MDM2 and CDK4 in both tumor areas. This strongly
supports the concept of a monoclonal origin of gliosarcomas and an evolution of
the sarcomatous component due to aberrant mesenchymal differentiation in a highly
malignant astrocytic neoplasm.
PMID- 10666372
TI - APC mutations in sporadic medulloblastomas.
AB - The cerebellar medulloblastoma (WHO Grade IV) is a highly malignant, invasive
embryonal tumor with preferential manifestation in children. Several molecular
alterations appear to be involved, including isochromosome 17q and the p53, PTCH,
and beta-catenin gene mutations. In this study, 46 sporadic medulloblastomas were
screened for the presence of mutations in genes of the Wnt signaling pathway (APC
and beta-catenin). Single-strand conformational polymorphism (SSCP) analysis
followed by direct DNA sequencing revealed 3 miscoding APC mutations in 2 (4.3%)
medulloblastomas. One case contained a GCA-->GTA mutation at codon 1296 (Ala-
>Val), and another case had double point mutations at codons 1472 (GTA-->ATA, Val
->Ile) and 1495 (AGT-->GGT, Ser-->Gly). Miscoding beta-catenin mutations were
detected in 4 tumors (8.7%). Three of these were located at codon 33 (TCT -->TTT,
Ser-->Phe) and another at codon 37 (TCT-->GCT, Ser-->Ala). Adenomatous polyposis
coli (APC) gene and beta-catenin mutations were mutually exclusive and occurred
in a total of 6 of 46 cases (13%). Although germline APC mutations are a well
established cause of familial colon and brain tumors (Turcot syndrome), this
study provides the first evidence that APC mutations are also operative in a
subset of sporadic medulloblastomas.
PMID- 10666373
TI - In vitro induction of giant cell tumors from cultured hamster islets treated with
N-Nitrosobis(2-Oxopropyl)amine.
AB - Giant cell carcinoma of the pancreas is a rare tumor. Its histogenesis is still
controversial. In a Syrian hamster pancreatic cancer model, tumors similar to
human giant cell carcinomas have been induced at an extremely low rate of
incidence and after the use of high doses of pancreatic carcinogens. Thus far no
tumors of giant cell type have been induced by the in vitro treatment of hamster
pancreatic ductal cells with the potent pancreatic carcinogen N-nitrosobis(2
oxopropyl)amine (BOP). In the present study we report the induction of giant cell
carcinoma from hamster islets treated with BOP in vitro. The results suggest that
in hamsters some component of islet cells, probably stem cells, are the origin of
giant cell carcinoma.
PMID- 10666374
TI - Sensitive immunoassay of tissue cell proteins procured by laser capture
microdissection.
AB - Coupling laser capture microdissection (LCM) with sensitive quantitative
chemiluminescent immunoassays has broad applicability in the field of proteomics
applied to normal, diseased, or genetically modified tissue. Quantitation of the
number of prostate-specific antigen (PSA) molecules/cell was conducted on human
prostate tissue cells procured by LCM from fixed and stained frozen sections.
Under direct microscopic visualization, laser shots 30 microm in diameter
captured specific cells from the heterogeneous tissue section onto a polymer
transfer surface. The cellular macromolecules from the captured cells were
solubilized in a microvolume of extraction buffer and directly assayed using an
automated (1.5 hour) sandwich chemiluminescent immunoassay. Calibration of the
chemiluminescent assay was conducted by developing a standard curve using known
concentrations of PSA. After the sensitivity, precision, and linearity of the
chemiluminescent assay was verified for known numbers of solubilized
microdissected tissue cells, it was then possible to calculate the number of PSA
molecules per microdissected tissue cell for case samples. In a study set of 20
cases, using 10 replicate samples of 100 laser shots per sample, the within-run
(intraassay) SD was approximately 10% of the mean or less for all cases. In this
series the number of PSA molecules per microdissected tissue cell ranged from 2 x
10(4) to 6. 3 x 10(6) in normal epithelium, prostate intraepithelial neoplasia
(PIN), and invasive carcinoma. Immunohistochemical staining of human prostate for
PSA was compared with the results of the soluble immunoassay for the same
prostate tissue section. Independent qualitative scoring of anti-PSA
immunohistochemical staining intensity paralleled the LCM quantitative
immunoassay for each tissue subpopulation and verified the heterogeneity of PSA
content between tissue subpopulations in the same case. Extraction buffers were
successfully adapted for both secreted and membrane-bound proteins. This
technology has broad applicability for the quantitation of protein molecules in
pure populations of tissue cells.
PMID- 10666375
TI - alpha5beta1 integrin expression and luminal edge fibronectin matrix assembly by
smooth muscle cells after arterial injury.
AB - Fibronectin is secreted from the cell as a soluble protein that must then
polymerize to regulate cell function. To elucidate the process of fibronectin
matrix assembly in vascular disease, we immunostained sections of balloon-injured
rat carotid artery for the fibronectin-binding alpha5beta1 integrin. Whereas
alpha5beta1 integrin was not evident in the normal carotid artery, its expression
was induced after a vascular injury. By 14 days, the alpha5beta1 integrin was
localized exclusively to the less differentiated smooth muscle cells (SMCs) at
the luminal surface of the neointima. Platelet-derived growth factor-BB, dominant
in neointimal formation, selectively increased the expression of the alpha5beta1
integrin by human SMCs in culture. To track the assembly of fibronectin fibers,
fluorescence-labeled soluble fibronectin protomers were added to cultured SMCs
and to fresh segments of normal and balloon-injured rat carotid arteries.
Fibronectin fiber formation in cultured SMCs could be detected within 10 minutes,
and was blocked by an RGD peptide, an anti-beta1 integrin antibody, and an anti
alpha5beta1 integrin antibody, but not by an anti-beta3 integrin antibody. En
face confocal microscopy of arterial segments revealed that soluble fibronectin
had polymerized on the alpha5beta1 integrin-expressing SMCs of the luminal
surface of the injured arterial neointima, but not on the alpha5beta1 integrin
negative neointimal SMCs below this or on the endothelial cells of uninjured
arteries. Furthermore, in situ fibronectin assembly by the neointimal SMCs was
inhibited by an RGD peptide and by an anti-beta1 integrin antibody. These studies
indicate that a subpopulation of SMCs in the repairing artery wall orchestrates
integrin-mediated fibronectin assembly.
PMID- 10666376
TI - Type VIII collagen stimulates smooth muscle cell migration and matrix
metalloproteinase synthesis after arterial injury.
AB - Type VIII collagen is a matrix protein expressed in a number of tissues
undergoing active remodeling, including injured arteries during neointimal
formation and in human atherosclerotic plaques; however, very little is known
about its function. We have investigated whether the type VIII collagen
stimulates smooth muscle cell (SMC) migration and invasion by binding to integrin
receptors and up-regulating matrix metalloproteinase (MMP) production. SMCs
attached to plates coated with type VIII collagen in a dose-dependent manner,
with maximal attachment occurring with coating solutions containing 25
microgram/ml collagen. Type VIII collagen at 100 microgram/ml stimulated an 83
fold increase in the migration of SMCs in a chemotaxis chamber. Antibodies
against beta1 integrin receptors prevented attachment and migration of SMCs.
Antibodies against alpha1 or alpha2 integrins reduced attachment of SMCs to type
VIII collagen by 29% and 77%, respectively. We found that SMCs grown from the rat
neointima, but not medial SMCs, increased their production of MMP-2 and -9 on
adherence to type VIII collagen. This suggests that there is an important
difference in phenotype between intimal and medial SMCs and that intimal SMCs
have distinct matrix-dependent signaling mechanisms. Our findings suggest that
type VIII collagen deposited in vascular lesions functions to promote SMC
attachment and chemotaxis, and signals through integrin receptors to stimulate
MMP synthesis, all of which are important mechanisms used in cell migration and
invasion.
PMID- 10666377
TI - Platelet-derived growth factor-A-induced retinal gliosis protects against
ischemic retinopathy.
AB - Retinal astrocytes are located in the nerve fiber layer and along retinal blood
vessels and have been hypothesized to participate in the induction and
maintenance of the blood-retinal barrier. Platelet-derived growth factor-A (PDGF
A) is normally produced by retinal ganglion cells and is involved in astrocyte
recruitment and proliferation. We used gain-of-function transgenic mice that
express PDGF-A in photoreceptors to explore the roles of PDGF-A and astrocytes in
the retina. Transgene-positive mice developed glial infiltration of the inner
retina and had significantly less oxygen-induced retinal vascular closure and no
neovascularization compared with littermate controls, which had prominent
vascular closure and neovascularization. The increased survival of endothelial
cells in transgenic mice in the face of oxygen-induced down-regulation of
vascular endothelial growth factor was accompanied by an increase in astrocyte
derived fibroblast growth factor-2. Therefore, PDGF-A increases retinal
astrocytes, which promote the survival of endothelial cells as well as their
expression of barrier characteristics.
PMID- 10666378
TI - Temporal accrual of complement proteins in amyloid plaques in Down's syndrome
with Alzheimer's disease.
AB - The complement system constitutes a series of enzymatic steps involved in the
inflammatory response and is activated in Alzheimer's disease (AD). Using Down's
syndrome (DS) brains as a temporal model for the progression of AD, we examined
components of the complement cascade and their relationship to other principal
events in AD pathology: Abeta42 deposition, neuritic changes, neurofibrillary
tangles (NFTs), and gliosis (reactive astrocytes, activated microglia). Adjacent
sections of frontal cortex from 24 DS subjects ranging in age from 12 to 73 years
were immunohistochemically examined for immunoreactivity (IR) of classical
complement proteins (Clq and C3), markers indicating activation of complement
(C4d and C5b-9), the complement inhibitor apolipoprotein J (apo J), and markers
of AD neuropathology. Abeta42-labeled diffuse plaques were first detected in a 12
year-old DS subject and were not labeled by any of the complement antibodies.
Colocalization of Abeta42 with Clq, C3, C4d, and/or apo J was first detected in
compacted plaques in the brain of a 15-year-old DS patient with features of
mature AD pathology, such as reactive astrocytes, activated microglia, dystrophic
neurites, and a few NFTs. IR for C4d and C5b-9 (membrane attack complex, MAC) was
observed in small numbers of plaque-associated dystrophic neurites and in focal
regions of pyramidal neurons in this 15-year-old. The only other young (=30
years) DS brain to show extensive complement IR was that of a 29-year-old DS
subject who also displayed the full range of AD neuropathological features. All
middle-aged and old DS brains showed IR for Clq and C3, primarily in compacted
plaques. In these cases, C4d IR was found in a subset of Abeta42 plaques and,
along with C5b-9 IR, was localized to dystrophic neurites in a subset of neuritic
plaques, neurons, and some NFTs. Our data suggest that in AD and DS, the
classical complement cascade is activated after compaction of Abeta42 deposits
and, in some instances, can progress to the local neuronal expression of the MAC
as a response to Abeta plaque maturation.
PMID- 10666379
TI - Up-regulation of BOB.1/OBF.1 expression in normal germinal center B cells and
germinal center-derived lymphomas.
AB - The BOB.1/OBF.1/OCAB.1 protein is a lymphocyte-specific transcriptional
coactivator. It interacts with the Oct1 and Oct2 transcription factors and
contributes to the transcriptional activity of octamer motifs. The analysis of
established B cell lines had suggested that BOB.1/OBF.1 is constitutively
expressed at all stages of B cell development. Here we show that expression of
BOB. 1/OBF.1 is regulated within the B cell lineage. Specifically, germinal
center B cells show highly increased BOB.1/OBF.1 levels. We can induce the up
regulation by stimulating primary splenic B cells, eg, by triggering CD40
signaling in the presence of interleukin-4. Expression of BOB.1/OBF.1 is
detectable but reduced in spleens from mice unable to undergo the germinal center
reaction due to mutations in the TNF receptor p55 or lymphotoxin beta (LTbeta)
receptor genes. Furthermore, we demonstrate that BOB.1/OBF.1 expression is highly
regulated in human B cell lymphomas. Whereas lymphomas representing pre- and
postfollicular B cell developmental stages are negative for BOB.1/OBF.1, high
level expression of BOB.1/OBF.1 is characteristic of germinal center-derived
tumors. In these tumors BOB.1/OBF.1 is typically coexpressed with high levels of
Bcl6. These results imply that overexpression of BOB.1/OBF.1, like overexpression
of Bcl6, might play a role in the pathogenesis of germinal center-derived B cell
lymphomas. Furthermore, overexpression of BOB.1/OBF.1 represents a characteristic
feature of these tumors that is useful in their identification.
PMID- 10666380
TI - Neutrophils, nitric oxide synthase, and mutations in the mutatect murine tumor
model.
AB - Mutatect MN-11 is a tumor line that can be grown subcutaneously in syngeneic
C57BL/6 mice. The frequency of spontaneously arising mutants at the hypoxanthine
phosphoribosyltransferase (Hprt) locus was observed to be elevated as a result of
in vivo growth. The objective of the present study was to identify factors in the
tumor microenvironment that might explain this increase in mutant frequency (MF).
When tumors were examined histologically, neutrophils were found to be the
predominant infiltrating cell type. Quantitative estimates of the number of
neutrophils and MF of tumors in different animals revealed a statistically
significant correlation (r = 0.63, P < 0.0001). Immunohistochemical analysis for
inducible nitric oxide synthase (iNOS) demonstrated its presence, mainly in
neutrophils. Biochemical analysis of tumor homogenates for nitric oxide synthase
(NOS) activity indicated a statistically significant correlation with MF (r =
0.77, P < 0.0001). Nitrotyrosine was detected throughout the tumor
immunohistochemically; both cytoplasmic and nuclear staining was seen. To
increase the number of infiltrating neutrophils, tumors were injected with
chemoattractant interleukin-8 and prostaglandin E2. This produced a statistically
significant increase in neutrophil content (P = 0.005) and MF (P = 0.0002). As in
control MN-11 tumors, neutrophil content and MF were strongly correlated (r =
0.63, P = 0. 003). Because neutrophils are a potential source of genotoxic
reactive oxygen and/or nitrogen species, our results support the notion that
these tumor-infiltrating cells may be mutagenic and contribute to the burden of
genetic abnormalities associated with tumor progression.
PMID- 10666381
TI - Immunological activation of dermal Langerhans cells in contact with lymphocytes
in a model of human inflamed skin.
AB - Langerhans cells play an important role in the skin's immune system. Little is
known, however, about the antigen-presenting capacity of Langerhans cells in the
context of skin inflammation. By immunohistochemistry we investigated the
phenotypic characteristics of epidermal and dermal Langerhans cells and their
spatial relationship with infiltrating lymphocytes. We studied skin flaps
autotransplanted to the oral cavity to fill a defect after maxillofacial cancer
surgery. In 15 of 21 cases sampled for the present study, the skin flaps were
severely inflamed by Candida albicans infection. In contrast to the normal skin,
such inflamed skin showed a marked increase in CD1a(+) dermal Langerhans cells.
Double immunohistochemistry revealed that dermal Langerhans cells abundantly
expressed B7-2 (CD86), a representative costimulatory molecule, and CD83, a
marker of mature dendritic cells. Furthermore, these dermal Langerhans cells were
in close contact with CD4(+)/CD45RO(+) lymphocytes. This cell-to-cell contact was
further visualized by immunoelectron microscopy. Langerhans cells were also
observed within lymphatic vessels that were identified by the expression of
vascular endothelial growth factor receptor-3. Ki-67 labeling indices were 4.2%
in CD4(+) T cells and 0.8% in CD8(+) T cells within the dermis. Factor XIIIa(+)
dermal dendrocytes were distributed outside the clusters of lymphocytes and were
not in contact with them. Our observations indicate that dermal Langerhans cells
in the inflamed skin are activated to express common phenotypes to mature
dendritic cells so that they could stimulate neighboring memory CD4(+) T cells.
PMID- 10666382
TI - Hyaluronan in peritumoral stroma and malignant cells associates with breast
cancer spreading and predicts survival.
AB - Hyaluronan (HA) is an extracellular matrix polysaccharide that promotes cell
migration through its cell surface receptors and by effecting changes in the
physical environment. HA expression is frequently increased in malignant tumors,
whereas its association with the invasive potential and patient outcome in breast
cancer has not been reported. The localization and signal intensity of HA was
analyzed in 143 paraffin-embedded tumor samples of human breast carcinoma using a
biotinylated HA-specific probe. In the immediate peritumoral stroma, HA signal
was moderately or strongly increased in 39% and 56% of the cases, respectively.
Normal ductal epithelium showed no HA, whereas in 57% of the tumors at least some
of the carcinoma cells were HA positive. The intensity of the stromal HA signal
and the presence of cell-associated HA were both significantly related to poor
differentiation of the tumors, axillary lymph node positivity, and short overall
survival of the patients. In Cox's multivariate analysis, both the intensity of
stromal HA signal alone and that combined with the HA positivity in tumor cells
were independent prognostic factors for overall survival. These results suggest
that HA is directly involved in the spreading of breast cancer and may offer a
potential target for new therapies.
PMID- 10666383
TI - Microsatellite instability in gastric intestinal metaplasia in patients with and
without gastric cancer.
AB - The role and significance of microsatellite instability (MSI) in gastric
carcinogenesis remain unknown. This study determined the chronology of MSI in
gastric carcinogenesis by examining intestinal metaplasia (IM) from patients with
and without gastric cancer. DNA was obtained from gastric specimens of 75
patients with gastric IM (30 cancer, 26 peptic ulcer, and 19 chronic gastritis
patients) and was amplified with a set of eight microsatellite markers. Eight
(26. 7%) tumors and seven (9.3%) IM samples (three from cancer-free patients)
displayed high-level MSI (three or more loci altered). Low-level MSI (one or two
loci altered) was detected in 50% of the tumors, in 40% of IM samples coexisting
with cancer, and in 38% of IM tissues of cancer-free individuals. Among the 30
cancer patients, microsatellites were more frequently altered in IM coexisting
with tumors that showed MSI (P = 0.003). In addition, patients with low-level MSI
in the tumor tissues were more likely to have active Helicobacter pylori
infection than those with stable tumors (P = 0.02). In conclusion, this study
indicates that MSI occurs not only in gastric IM of patients with gastric
carcinoma, but also in IM of cancer-free individuals. These data suggest that the
progressive accumulation of MSI in areas of IM may contribute to gastric cancer
development, representing an important molecular event in the multistep gastric
carcinogenesis cascade.
PMID- 10666384
TI - Localization of cyclooxygenase-2 in human sporadic colorectal adenomas.
AB - A putative target for the anti-colorectal cancer action of nonsteroidal anti
inflammatory drugs is the inducible isoform of cyclooxygenase (COX), COX-2. COX-2
is expressed within intestinal adenomas in murine polyposis models, but
expression has been poorly characterized in human colorectal neoplasms.
Therefore, we investigated the localization of the COX-2 protein in human
sporadic colorectal adenomas. Immunohistochemistry for COX-2 and CD68 (a tissue
macrophage marker) was performed on formalin-fixed, paraffin-embedded (n = 52)
and frozen, acetone-fixed (n = 6) sections of human sporadic colorectal adenomas.
Forty of 52 (77%) formalin-fixed adenomas expressed immunoreactive COX-2. COX-2
was localized to superficial interstitial macrophages in 39 cases (75%) and to
deep interstitial macrophages in 9 cases (17%). COX-2 staining of dysplastic
epithelial cells was observed in 15 cases (29%). A logistic regression analysis
identified the adenoma site (P = 0.012) and histological type (P = 0.001) as
independent predictors of superficial macrophage COX-2 expression. There was no
relationship between the number of macrophages within an adenoma and macrophage
COX-2 expression. These results indicate that COX-2 is expressed predominantly by
interstitial macrophages within human sporadic colorectal adenomas. If COX-2 does
indeed play a role in the early stages of colorectal carcinogenesis in man, these
data suggest COX-2-mediated paracrine signaling between the macrophages and
epithelial cells within adenomas.
PMID- 10666385
TI - Chromosomal imbalances in Barrett's adenocarcinoma and the metaplasia-dysplasia
carcinoma sequence.
AB - To characterize cytogenetic alterations found in Barrett's adenocarcinoma (BA)
and, more importantly, its premalignant stages, we studied chromosomal imbalances
in various lesions in the histologically proposed metaplasia-dysplasia-carcinoma
sequence using comparative genomic hybridization (CGH). Using 30 esophageal
adenocarcinoma resection specimens, we were able to study 30 areas of Barrett's
adenocarcinoma and 8 lymph node metastases (LN). In addition, we investigated 25
premalignant lesions adjacent to BA derived from a subset of 14 resection
specimens including 11 areas of high grade dysplasia (HGD), 8 areas of low grade
dysplasia (LGD), and 6 areas of intestinal metaplasia (IM), which were laser
microdissected and studied with CGH. To validate the CGH findings, fluorescence
in situ hybridization analysis on 13 BA with probes specific for HER-2/neu and
20q13.2 were performed. The chromosomal alterations most often identified in BA
were: gains on 8q (80%), 20q (60%), 2p, 7p and 10q (47% each), 6p (37%), 15q
(33%) and 17q (30%). Losses were observed predominantly on the Y-chromosome
(76%), 4q (50%), 5q and 9p (43% each), 18q (40%), 7q (33%) and 14q (30%). High
level amplifications were observed on 8q23-qter, 8p12-pter, 7p11-p14, 7q21-31,
17q11-q23. Recurrent chromosomal changes were also identified in metaplastic
(gains on 8q, 6p, 10q, losses on 13q, Y, 9p) and dysplastic epithelium (gains on
8q, 20q, 2p, 10q, 15q, losses on Y, 5q, 9p, 13q, 18q). Novel amplified
chromosomal regions on chromosomes 2p and 10q were detected in both Barrett's
adenocarcinoma and premalignant lesions. An increase of the average number of
detected chromosomal imbalances from IM (7.0 +/- 1.7), to LGD (10.8 +/- 2.2), HGD
(13.4 +/- 1.1), BA (13.3 +/- 1.4), and LN (22 +/- 1.2) was seen. Although the
detection of common chromosomal alterations in premalignant lesions and adjacent
carcinomas suggest a process of clonal expansion, the occurrence of several
chromosomal changes in an apparently random order relative to one another is
striking evidence that clonal evolution is more complex than would be predicted
by linear models. This is probably a reflection of the existence of many
divergent neoplastic subpopulations and highlights one of the main problems
associated with surveillance of Barrett's patients, namely sampling error.
PMID- 10666386
TI - Cellular distribution and clinical value of urokinase-type plasminogen activator,
its receptor, and plasminogen activator inhibitor-2 in esophageal squamous cell
carcinoma.
AB - To assess the participation of the plasminogen activation system in the
invasiveness of esophageal squamous cell carcinoma, we performed
immunohistochemistry and in situ hybridization to study the distribution of a
urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR), and
plasminogen activator inhibitor-2 (PAI-2). u-PA and PAI-2 were expressed
heterogeneously in cancer cells, and restricted expression was found in stromal
cells, especially fibroblasts, that were located in the immediate proximity of
the cancerous cells. u-PAR was found only in cancer cells located at the
periphery of tumors. Compared with patients with u-PA-negative cancer cells,
patients with u-PA-positive cancer cells more frequently showed a neoplastic
invasion beyond the muscularis propria and lymph node metastases. They also
showed a significantly shorter 5-year overall survival. Patients with PAI-2
positive fibroblasts showed significantly lower levels of local invasiveness,
represented by a neoplastic invasion beyond the muscularis propria, than those
who were PAI-2 negative. Our results suggest that the expression of u-PA in
esophageal squamous cell carcinoma is predictive of poor survival, whereas the
expression of PAI-2 in the fibroblasts surrounding them is protective. An
analysis of u-PA and PAI-2 expression in cancer cells and their surrounding
fibroblasts may be useful for predicting the prognosis of patients with
esophageal squamous cell carcinoma.
PMID- 10666387
TI - Expression of a novel transmembrane carbonic anhydrase isozyme XII in normal
human gut and colorectal tumors.
AB - Carbonic anhydrase isozyme XII is a recently discovered member of the alpha
carbonic anhydrase gene family with a suggested role in von Hippel-Lindau gene
mediated carcinogenesis. Increased expression of its mRNA has been observed in
renal and lung carcinomas. This paper presents the localization of CA XII in the
normal human gut and in colorectal tumors. Immunohistochemistry performed using a
polyclonal antibody raised against truncated CA XII revealed prominent polarized
staining for CA XII in the basolateral plasma membrane of the enterocytes of the
normal large intestine, the reaction being most intense in the surface epithelial
cuff region. Most colorectal tumors displayed abnormal expression of CA XII; the
most dramatic change was observed in the deep parts of the adenomatous mucosa,
where the positive immunoreaction clearly increased along with the grade of
dysplasia. Adenomas with severe dysplasia and carcinomas showed an equal, diffuse
staining pattern. The results indicate region-specific regulation of CA XII
expression along the cranial-caudal axis of the human gut, whereas its diffuse
expression in the most malignant tumors seems to correlate with their biological
behavior.
PMID- 10666388
TI - Cyclin D2 overexpression and lack of p27 correlate positively and cyclin E
inversely with a poor prognosis in gastric cancer cases.
AB - G1 cyclins and cyclin-dependent kinase (CDK) complexes play important roles in G1
cell cycle transition, and their overexpression is implicated for neoplasia. The
p27 protein (p27) negatively regulates G1 progression by binding to G1
cyclins/CDK complexes and inhibits their activity, resulting in inhibition of
entry to the cell cycle. We investigated overexpression of cyclin D1 (CCND1),
cyclin D2 (CCND2), cyclin E (CCNE), CDK2, and CDK4, in addition to p27, in 260
gastric cancer cases on the basis of Western blots, reverse transcriptase
polymerase chain reaction Southern blots, and immunohistochemistry to clarify the
roles of these proteins in tumor progression and prognosis. Examination of 20
cases of fresh cancer and matched normal tissues demonstrated a clear tendency
for increased mRNA synthesis to be more frequent than expected from protein
levels, and a direct correlation between p27 protein and mRNA was not found.
Immunohistochemistry demonstrated 21. 5%, 34.2%, 30.4%, 44.2%, and 48.0%
positivity for CCND1, CCND2, CCNE, CDK2, and CDK4, respectively, in the 260
gastric cancer cases. Overexpression of CCND2 and CDK4 significantly correlated
with tumor progression. Moreover, CCND2 cytoplasmic staining (26.2%) appeared to
be strictly linked with progression, whereas nuclear staining (7. 8%)
demonstrated an inverse correlation. Survival curves showed CCND2 (especially
cytoplasmic staining) and CDK4 positivity to be associated with a poor prognosis
and CCNE positivity with a better prognosis. Tumors with high p27 labeling
indices (LIs) were well differentiated, with low levels of invasion and lymph
node metastasis. p27-negative cases (37.3%) demonstrated a poor prognosis.
Multivariate analysis revealed positivity for CCND2 and negativity for p27 to be
independent prognostic factors. There were no direct links among CCND2, CCNE,
CDK4, and p27. The results indicate that CCND2 cytoplasmic localization might
reflect an important physiological role in tumor progression, whereas CCNE
overexpression correlates with differentiation and a good prognosis, possibly
because of accumulation of inactive forms of CCNE-CDK2 complexes. Loss of p27
caused by degradation activity may affect tumor cell growth in the presence of an
altered extracellular matrix, facilitating metastasis. Cell-cycle-regulatory
proteins appear to work independently.
PMID- 10666389
TI - Carcinoembryonic antigen family members CEACAM6 and CEACAM7 are differentially
expressed in normal tissues and oppositely deregulated in hyperplastic colorectal
polyps and early adenomas.
AB - Four members of the carcinoembryonic antigen (CEA) family, CEA, CEACAM1 (BGP),
CEACAM6 (NCA-50/90), and CEACAM7 (CGM2), are coexpressed in normal colorectal
epithelia but are deregulated in colorectal cancers, where they could play a role
in tumorigenesis. As a basis for functional studies, their expression patterns in
normal tissues first need to be clarified. This is well documented for CEACAM1
and CEA but not for CEACAM6 or CEACAM7. We have now carried out
immunohistochemical expression studies on 35 different organs, using CEACAM6
specific (9A6) and CEACAM7-specific (BAC2) monoclonal antibodies. CEACAM7 was
only found on the apical surface of highly differentiated epithelial cells in the
colorectal mucosa and on isolated ductal epithelial cells within the pancreas.
CEACAM6 was expressed in granulocytes and epithelia from various organs. CEACAM6
and CEACAM7 expression correlated with apoptosis at the table region of the
normal colon, and both were absent from highly proliferating cells at the base of
colonic crypts. CEACAM6 revealed a broader expression zone in proliferating cells
in hyperplastic polyps and adenomas compared with normal mucosa, whereas CEACAM7
was completely absent. Down-regulation of CEACAM7 and up-regulation of CEACAM6
expression in hyperplastic polyps and early adenomas represent some of the
earliest observable molecular events leading to colorectal tumors.
PMID- 10666390
TI - Liver regeneration in rats with retrorsine-induced hepatocellular injury proceeds
through a novel cellular response.
AB - The adult rodent liver contains at least two recognized populations of cells with
stem-like properties that contribute to liver repair/regeneration under different
pathophysiological circumstances: (i) unipotential committed progenitor cells
(differentiated hepatocytes and biliary epithelial cells) and (ii) multipotential
nonparenchymal progenitor cells (oval cells). In retrorsine-induced
hepatocellular injury the capacity of fully differentiated rat hepatocytes to
replicate is severely impaired and massive proliferation of oval cells does not
occur. Nevertheless, retrorsine-exposed rats can replace their entire liver mass
after 2/3 surgical partial hepatectomy through the emergence and expansion of a
population of small hepatocyte-like progenitor cells that expresses phenotypic
characteristics of fetal hepatoblasts, oval cells, and fully differentiated
hepatocytes, but differ distinctly from each type of cell. The activation,
proliferation, and complete regeneration of normal liver structure from small
hepatocyte-like progenitor cells have not been recognized in other models of
liver injury characterized by impaired hepatocyte replication. We suggest that
the selective emergence and expansion of small hepatocyte-like progenitor cells
observed in the retrorsine model reflect a novel mechanism of complete liver
regeneration in the adult rat. Furthermore, we suggest that these cells may
represent a novel progenitor cell population that (i) responds to liver deficit
when the replication capacity of differentiated hepatocytes is impaired, (ii)
expresses an extensive proliferative capacity, (iii) can give rise to large
numbers of progeny hepatocytes, and (iv) can restore tissue mass.
PMID- 10666391
TI - Expression of an intestine-specific transcription factor (CDX1) in intestinal
metaplasia and in subsequently developed intestinal type of cholangiocarcinoma in
rat liver.
AB - CDX1 is a caudal-type homeobox intestine-specific transcription factor that has
been shown to be selectively expressed in epithelial cells in intestinal
metaplasia of the human stomach and esophagus and variably expressed in human
gastric and esophageal adenocarcinomas (Silberg DG, Furth EE, Taylor JK, Schuck
T, Chiou T, Traber PG: Gastroenterology 1997, 113: 478-486). Through the use of
immunohistochemistry and Western blotting, we investigated whether CDX1 is also
uniquely associated with the intestinal metaplasia associated with putative
precancerous cholangiofibrosis induced in rat liver during furan
cholangiocarcinogenesis, as well as expressed in neoplastic glands in a
subsequently developed intestinal type of cholangiocarcinoma. In normal, control
adult rat small intestine, specific nuclear immunoreactivity for CDX1 was most
prominent in enterocytes lining the crypts. In comparison, epithelium from
intestinal metaplastic glands within furan-induced hepatic cholangiofibrosis and
neoplastic epithelium from later developed primary intestinal-type
cholangiocarcinoma each demonstrated strong nuclear immunoreactivity for CDX1.
CDX1-positive cells were detected in hepatic cholangiofibrotic tissue as early as
3 weeks after the start of chronic furan treatment. We further determined that
the percentages of CDX1-positive neoplastic glands and glandular nuclei are
significantly higher in primary tumors than in a derived, transplantable
cholangiocarcinoma serially-propagated in vivo. Western blotting confirmed our
immunohistochemical results, and no CDX1 immunoreactivity was detected in normal
adult rat liver or in hyperplastic biliary epithelial cells. These findings
indicate that CDX1 is specifically associated with early intestinal metaplasia
and a later developed intestinal-type of cholangiocarcinoma induced in the liver
of furan-treated rats.
PMID- 10666392
TI - Twin-to-twin transfusion syndrome. Role of the fetal renin-angiotensin system.
AB - The twin-to-twin transfusion syndrome (TTS) results from an unbalanced blood
supply through placental anastomoses in monochorionic twins. It induces growth
restriction, renal tubular dysgenesis, and oliguria in the donor and
visceromegaly and polyuria in the recipient. A better understanding of its
pathophysiology could contribute to improving the management of TTS, which still
carries a high perinatal mortality in both twins. As well as several other
candidates, the renin-angiotensin system might be involved in TTS. To evaluate
its role in the pathogenesis of the syndrome, we studied the kidneys of 21 twin
pairs who died from TTS at 19 to 30 weeks, compared with 39 individuals in a
control group, using light microscopy, immunohistochemistry, and in situ
hybridization. The overexpression of the renin protein and transcript with
frequent evidence of renin synthesis by mesangial cells was observed in the donor
kidneys, presumably as a consequence of chronic renal hypoperfusion. This
upregulation of renin synthesis might be beneficial to restore euvolemia. In
severe cases of TTS, however, angiotensin-II-induced vasoconstriction acts as an
additional deleterious factor by further reducing the renal blood flow in donors.
In recipients, renin expression was virtually absent, possibly because it was
down-regulated by hypervolemia. However, in addition to congestion and
hemorrhagic infarction, there were severe glomerular and arterial lesions
resembling those observed in polycythemia- or hypertension-induced
microangiopathy. We speculate that fetal hypertension in the recipient might be
partly mediated by the transfer of circulating renin produced by the donor,
through the placental vascular shunts.
PMID- 10666393
TI - Studies on the mechanisms and kinetics of apoptosis induced by microinjection of
cytochrome c in rat kidney tubule epithelial cells (NRK-52E).
AB - Recent reports substantiating the role of cytochrome c in the induction of
apoptosis led us to examine the kinetics and mechanisms involved in this process
as an extension of our ongoing studies of cell injury and cell death.
Microinjection of cytochrome c into NRK-52E kidney cells produced rapid
apoptosis, which usually began within 30 minutes and reached a maximum of 60-70%
by 3 hours. The changes that occurred included four phases: an initial shrinkage
phase, an active phase, a spherical phase, and a necrotic phase. For
morphological purposes, the progressive changes were followed by phase-contrast
and fluorescence microscopy, transmission and scanning electron microscopy, and
time-lapse video microscopy. Cells first showed shrinkage, then displayed
multiple pseudopods, which rapidly extended and retracted, giving the cells a
bosselated appearance. During this active phase there was chromatin condensation,
mitochondria were swollen but retained membrane potential, and the endoplasmic
reticulum was dilated. Within 2-4 hours, active-phase cells became spherical and
smooth-surfaced but were still alive, the nuclei showed chromatin clumping, the
mitochondria underwent high-amplitude swelling but retained membrane potential,
the endoplasmic reticulum was highly dilated, and many large apical vacuoles were
present. Elevation of [Ca(2+)](i) was seen at the late spherical phase, shortly
before cell death. Pretreatment with the caspase 3 inhibitor (Ac-DEVD-CHO)
prevented apoptosis, whereas overexpression of Bcl-2 did not. Depletion of
cellular ATP by cyanide inhibition of energy metabolism prevented cytochrome c
from inducing the active and later phases of apoptosis. The results clearly
indicate that cytochrome c-induced apoptosis is a dynamic and energy-requiring
process that has a distinct active and spherical phase before cell death.
PMID- 10666394
TI - Comparative genomic hybridization reveals frequent losses of chromosomes 1p and
3q in pheochromocytomas and abdominal paragangliomas, suggesting a common genetic
etiology.
AB - Pheochromocytomas and abdominal paragangliomas are rare, catecholamine-producing
tumors that arise from the chromaffin cells derived from the neural crest. We
used comparative genomic hybridization (CGH) to screen for copy number changes in
23 pheochromocytomas and 11 abdominal paragangliomas. The pattern of copy number
changes was similar between pheochromocytomas and paragangliomas, with the most
consistent finding being loss of 1cen-p31, which was detected in 28/34 tumors
(82%). Losses were also found on 3q22-25 (41%), 11p (26%), 3p13-14 (24%), 4q
(21%), 2q (15%), and 11q22-23 (15%), and gains were detected on 19p (26%), 19q
(24%), 17q24-qter (21%), 11cen-q13 (15%), and 16p (15%). Losses of 1p and 3q were
detected in the majority of tumors, whereas gains of 19p and q, 17q, and 16p were
seen only in tumors with six or more CGH alterations. This progression of genetic
events did not correspond with the conversion to a malignant phenotype. CGH
alterations involving chromosome 11 were more frequent in the malignant tumors,
compared with the benign tumors (9/12 versus 3/16). In summary, we propose that
pheochromocytomas and abdominal paragangliomas, which share many clinical
features, also have a common genetic origin and that the loss of 1cen-p31
represents an early and important event in tumor development.
PMID- 10666395
TI - Frequent T and B cell oligoclones in histologically and immunophenotypically
characterized angioimmunoblastic lymphadenopathy.
AB - The identification of clonal rearrangements of T cell receptor (TCR) genes is
central to the diagnosis of T cell lymphomas. However, in angioimmunoblastic
lymphadenopathy (AILD), first described as a nonneoplastic proliferation
associated with immunodeficiency, the heterogeneity of TCR and IgH gene
rearrangements suggest that some cases may harbor multiple lymphoid clones. In
this study we have isolated DNA from archival paraffin biopsy material from 22
cases of AILD identified on the basis of classical histological and
immunohistochemical features with the aim of establishing the occurrence of
clones and oligoclones, the frequency of TCR and immunoglobulin heavy chain (IgH)
variable (v) gene use, and the relationship of these findings to the presence of
Epstein-Barr virus. DNA extracted from the biopsies was amplified using the
polymerase chain reaction (PCR) and sequenced to detect functional and
nonfunctional gene rearrangements. Epstein-Barr virus-encoded short RNA species
(EBERs) were detected using in situ hybridization combined with immunochemistry
to identify the phenotype of the Epstein-Barr virus-infected cells. Fifty-seven
clonal products were found in 20/22 patients: TCRgamma clonal products were
identified in 16/22, TCRbeta clonal products in 16/22 and IgH clonal products in
6/22 cases. Oligoclonal PCR products were seen for TCR in 3/22 and for IgH in
3/22 cases. In one biopsy PCR products from all reactions were polyclonal.
Sequence analysis revealed functional TCRgamma, TCRbeta, and IgH sequences in
6/12, 9/11, and 8/8 cases, respectively. Functional TCR and/or IgH oligoclones
were detected in 6/20 (30%) cases. In addition, nonfunctional TCR and IgH
sequences were found in 11 cases. EBERs were identified in 18/20 cases varying
from occasional to 25 to 30% nuclei staining and were associated with both T and
B cells, although the majority were of indeterminate phenotype. The presence of
EBERs was not associated with all clonal IgH gene rearrangements but was
associated with B cell oligoclones. Patterns of gene recombinations indicated
that the majority of TCRgamma recombinations used GV1 and GJ1S3/2S3 genes. Six
out of eleven cases used TCR BV4S1 or BV2S1 genes associated with various BJ and
BD1/2 genes. No common IgH gene usage was identified, but 8 clones had varying
degrees of replacement and silent mutations (0.6-10.1%), consistent with B cell
clones having undergone somatic mutation in the germinal center, and 3 clones
harbored unmutated V genes, consistent with naive B cells. Our data do not
support the concept of AILD as a clearly defined peripheral T cell lymphoma
(PTCL). Rather, they suggest that AILD as defined by histology and
immunohistochemistry is either a heterogeneous entity or represents a
lymphoproliferation associated with immunodeficiency in which clonal T cell or B
cell proliferation may occur.
PMID- 10666396
TI - Site-specific epithelial-mesenchymal interactions in digestive neuroendocrine
tumors. An experimental in vivo and in vitro study.
AB - Little is known about the functional interactions between digestive
neuroendocrine tumor cells and their stromal microenvironment. The focus of our
study is whether mesenchymal cells modulate peptide expression, cell
proliferation, and invasiveness in digestive neuroendocrine tumor cells. We
designed an experimental in vivo and in vitro study using the mouse
enteroendocrine cell line STC-1. In vivo, STC-1 cells were injected
subcutaneously in 18 immunosuppressed newborn rats. At day 21, all animals
presented poorly differentiated neuroendocrine tumors with lung metastases.
Subcutaneous tumors were usually limited by a capsule containing basement
membrane components and myofibroblasts that presented a low mitotic index. Lung
tumors were devoid of capsule and poor in myofibroblasts, and their mitotic index
was high. The profile of peptide expression in STC-1 tumors was different from
that of cultured STC-1 cells. In vitro, STC-1 cells were cultured with
fibroblasts of different origins, including dermis, lung, digestive tract, and
liver. Based on their origin, myofibroblasts differentially modulated hormone
synthesis, proliferation, spreading, and adhesion of STC-1 cells. In conclusion,
our results show that site-specific functional interactions between mesenchymal
and neuroendocrine cells may contribute to modulating the behavior of digestive
neuroendocrine tumors, depending on their growth site.
PMID- 10666397
TI - The shed ectodomain of collagen XVII/BP180 is targeted by autoantibodies in
different blistering skin diseases.
AB - Collagen XVII/BP180, an epidermal adhesion molecule, exists as a full-length
transmembrane protein and as a soluble 120-kd ectodomain that is shed from the
keratinocyte surface by furin-mediated proteolysis. Despite a number of studies
on autoantibody targets in blistering skin diseases, it has remained unclear
whether the physiologically shed ectodomain of collagen XVII plays a role as an
autoantigen. Here we isolated the authentic, soluble form of human collagen XVII
and showed that it is an autoantigen recognized by IgG and IgA autoantibodies in
different blistering skin diseases and is, in some cases, the preferential
target. The ectodomain was isolated from the epidermis, keratinocyte media,
amniotic fluid, and pemphigoid blister fluid, and autoantibodies affinity
purified with this ectodomain bound to the proximal surface of the epidermis in
normal skin but not in collagen XVII-deficient skin. The antibody reactivity was
not dependent on the native conformation or the N-glycosylation of the soluble
ectodomain, but was abolished by collagenase treatment. Sera of 81 patients with
a clinically active blistering skin disease were reacted with full-length
collagen XVII, the authentic soluble ectodomain, and recombinant fragments. In
bullous and cicatricial pemphigoid, IgG reactive with full-length collagen XVII
also recognized the soluble ectodomain. In linear IgA dermatosis and chronic
bullous dermatosis of childhood, IgA targeted the soluble ectodomain more
efficiently than the full-length protein. The use of recombinant fragments
demonstrated that epitopes were present in several noncollagenous and collagenous
subdomains of the molecule, and that a significant portion of the sera targeted
Col15 domain, a hitherto unrecognized epitope region.
PMID- 10666398
TI - Blockade of vascular endothelial cell growth factor receptor signaling is
sufficient to completely prevent retinal neovascularization.
AB - Retinal vasculogenesis and ischemic retinopathies provide good model systems for
study of vascular development and neovascularization (NV), respectively. Vascular
endothelial cell growth factor (VEGF) has been implicated in the pathogenesis of
retinal vasculogenesis and in the development of retinal NV in ischemic
retinopathies. However, insulin-like growth factor-I and possibly other growth
factors also participate in the development of retinal NV and intraocular
injections of VEGF antagonists only partially inhibit retinal NV. One possible
conclusion from these studies is that it is necessary to block other growth
factors in addition to VEGF to achieve complete inhibition of retinal NV. We
recently demonstrated that a partially selective kinase inhibitor, PKC412, that
blocks phosphorylation by VEGF and platelet-derived growth factor (PDGF)
receptors and several isoforms of protein kinase C (PKC), completely inhibits
retinal NV. In this study, we have used three additional selective kinase
inhibitors with different selectivity profiles to explore the signaling pathways
involved in retinal NV. PTK787, a drug that blocks phosphorylation by VEGF and
PDGF receptors, but not PKC, completely inhibited retinal NV in murine oxygen
induced ischemic retinopathy and partially inhibited retinal vascularization
during development. CGP 57148 and CGP 53716, two drugs that block phosphorylation
by PDGF receptors, but not VEGF receptors, had no significant effect on retinal
NV. These data and our previously published study suggest that regardless of
contributions by other growth factors, VEGF signaling plays a critical role in
the pathogenesis of retinal NV. Inhibition of VEGF receptor kinase activity
completely blocks retinal NV and is an excellent target for treatment of
proliferative diabetic retinopathy and other ischemic retinopathies.
PMID- 10666399
TI - Helicobacter pylori gastritis in cats with long-term natural infection as a model
of human disease.
AB - A natural infection with Helicobacter pylori (H. pylori) in domestic cats (Felis
cattus) less than 2 years of age has been well described in a closed colony of
animals. Six cats from this colony that were serially evaluated by culture,
polymerase chain reaction, and light and electron microscopy for a period of 3
years demonstrated persistent gastric colonization with a single cag(-) vac(+)
strain of H. pylori. In these cats, as well as five other 5- to 6-year-old cats
that were examined, a long-term infection resulted in chronic diffuse
lymphofollicular atrophic gastritis with areas of mucosal dysplasia in the antrum
and predominantly midsuperficial gastritis in the body and cardia.
Topographically, the distribution of lesions was similar in both young and older
cats and closely resembled that found in humans, with the most severe changes
occurring in the gastric antrum. Few granulocytes and no significant elevation in
mast cells were seen in older H. pylori-infected cats compared with uninfected
controls; however, marked increases in interepithelial globule leukocytes and
numerous active mucosal lymphoid follicles were present in infected animals.
Indices of gastritis were significantly greater in older infected cats when
compared with uninfected controls and younger cats (P < 0.05). The antral cell
proliferation index of infected older cats was significantly (P = 0.021) greater
than that of uninfected controls. Apoptotic indices of the gastric antrum and
body of infected cats were significantly (P = 0.01) increased versus controls.
Chronic infection with H. pylori in cats shares many features of long-term H.
pylori infection in humans, including the development of preneoplastic processes.
This similarity provides useful, comparative insights into host-pathogen
interactions.
PMID- 10666400
TI - Chronic airway hyperreactivity, goblet cell hyperplasia, and peribronchial
fibrosis during allergic airway disease induced by Aspergillus fumigatus.
AB - Clinical allergic airway disease is associated with persistent airway
hyperreactivity and remodeling, but little is known about the mechanisms leading
to these alterations. This paucity of information is related in part to the
absence of chronic models of allergic airway disease. Herein we describe a model
of persistent airway hyperreactivity, goblet cell hyperplasia, and subepithelial
fibrosis that is initiated by the intratracheal introduction of Aspergillus
fumigatus spores or conidia into the airways of mice previously sensitized to A.
fumigatus. Similar persistent airway alterations were not observed in
nonsensitized mice challenged with A. fumigatus conidia alone. A. fumigatus
sensitized mice exhibited significantly enhanced airway hyperresponsiveness to a
methacholine challenge that was still present at 30 days after the conidia
challenge. Eosinophils and lymphocytes were present in bronchoalveolar lavage
(BAL) samples from A. fumigatus-sensitized mice at all times after conidia
challenge. Compared with levels measured in A. fumigatus-sensitized mice
immediately before conidia, significantly elevated interferon-gamma (IFN-gamma)
and transforming growth factor (TGF-beta) levels were present in whole lung
homogenates up to 7 days after the conidia challenge. At day 30 after conidia
challenge, significantly elevated levels of interleukin-4 (IL-4) and IL-13 were
present in the A. fumigatus-sensitized mice. Histological analysis revealed
profound goblet cell hyperplasia and airway fibrosis at days 30 after conidia,
and the latter finding was confirmed by hydroxyproline measurements. Thus the
introduction of A. fumigatus conidia into A. fumigatus-sensitized mice results in
persistent airway hyperresponsiveness, fibrosis, and goblet cell hyperplasia.
PMID- 10666401
TI - Under new management: A six-month progress report on Circulation Research.
PMID- 10666402
TI - Spatial hemodynamics, the endothelium, and focal atherogenesis: a cell cycle
link?
PMID- 10666403
TI - Cellular and molecular dissection of reperfusion injury: ROS within and without.
PMID- 10666404
TI - Mitochondrial oxidative stress in heart failure: "oxygen wastage" revisited.
PMID- 10666405
TI - Myocyte death in the pathological heart.
PMID- 10666406
TI - The insulin-like growth factor axis: A review of atherosclerosis and restenosis.
AB - Insulin-like growth factors I and II (IGF-I and -II) and their regulatory
proteins are secreted by cells of the cardiovascular system. They are growth
promoters for arterial cells and mediators of cardiovascular disease. IGFs are
bound to IGF binding proteins (IGFBPs), which modulate IGF ligand-receptor
interaction and consequently to IGF action. IGFBPs are in turn
posttranslationally modulated by specific proteases. This dynamic balance (IGFs,
IGFBPs, and IGFBP proteases) constitutes the IGF axis and ultimately determines
the extent of IGF-dependent cellular effects. Dysregulated actions of this axis
influence coronary atherosclerosis through effects on vascular smooth muscle cell
growth, migration, and extracellular matrix synthesis in the atherosclerotic
plaque. IGF-I promotes macrophage chemotaxis, excess LDL cholesterol uptake, and
release of proinflammatory cytokines. Endothelial cells also receive the effects
of IGFs stimulating their migration and organization forming capillary networks.
Neointimal hyperplasia of restenosis after coronary artery injury is also
modulated by the IGF axis. IGFs stimulate vascular smooth muscle cell
proliferation and migration to form the neointima and upregulate tropoelastin
synthesis after disruption of the elastic layer. Understanding IGF axis
regulation establishes a scientific basis for strategies directed to limit or
reverse plaque growth and vulnerability in atherosclerosis and in the neointimal
hyperplasia of restenosis.
PMID- 10666407
TI - The stromal cell-derived factor-1 chemokine is a potent platelet agonist highly
expressed in atherosclerotic plaques.
AB - Chemokines are chemotactic cytokines that activate and direct the migration of
leukocytes. However, their role in modulating platelet function has not been
shown. We studied the direct effect of chemokines on human platelets and found
that of the 16 tested only stromal cell-derived factor (SDF)-1 induced platelet
aggregation, accompanied by a rise in intracellular calcium. Platelets expressed
the SDF-1 receptor, CXCR4, and an antibody to CXCR4 and pertussis toxin inhibited
SDF-1-induced platelet aggregation, confirming that this effect is mediated
through CXCR4, a Galphai-coupled receptor. SDF-1-induced platelet aggregation was
also inhibited by wortmannin, LY294002, and genistein, suggesting that
phosphatidylinositol 3-kinase and tyrosine kinase are likely involved in SDF-1
induced platelet aggregation. Because chemokines are produced from multiple
vascular cells and atherosclerotic vessels are prone to develop platelet-rich
thrombi, we examined the expression of SDF-1 in human atheroma. SDF-1 protein was
highly expressed in smooth muscle cells, endothelial cells, and macrophages in
human atherosclerotic plaques but not in normal vessels. Our studies demonstrate
a direct effect of a chemokine in inducing platelet activation and suggest a role
for SDF-1 in the pathogenesis of atherosclerosis and thrombo-occlusive diseases.
PMID- 10666408
TI - Angiotensin-converting enzyme inhibitors downregulate tissue factor synthesis in
monocytes.
AB - Angiotensin-converting enzyme (ACE) inhibitors reduce the risk of recurrent
myocardial infarction in patients with left ventricular dysfunction. Tissue
factor (TF), the initiator of blood coagulation, plays a pivotal role in arterial
thrombosis that occurs after atherosclerotic plaque fissuring. Because monocytes
synthesize TF and contain several components of the renin-angiotensin system, we
investigated the possibility that ACE inhibitors could modulate monocyte TF
expression. Mononuclear leukocytes from healthy volunteers were incubated with
endotoxin in the presence or absence of different ACE inhibitors. Captopril
reduced TF expression in endotoxin-stimulated mononuclear leukocytes, as measured
by a 1-stage clotting assay and ELISA analysis, by approximately 60%. The effect
was dose-dependent and was attributable to ACE inhibition, given that other ACE
inhibitors, such as idrapril or fosinopril, and losartan, an antagonist of the
angiotensin II AT(1) receptor, caused a comparable reduction in TF activity.
Reverse transcriptase-polymerase chain reaction indicated that endotoxin-mediated
increased levels of TF mRNA were inhibited by ACE inhibitors. Moreover, endotoxin
induced nuclear factor-kappaB translocation to the promoter region of the gene
encoding for TF was markedly inhibited by captopril. The finding that ACE
inhibitors and angiotensin II AT(1) antagonists can potentially modulate TF
expression by mononuclear cells has important biological and therapeutic
implications for the evolution of thrombi. Our results suggest that the anti
ischemic effect of these drugs might be explained, at least in part, by their
ability to reduce TF expression in monocytes.
PMID- 10666409
TI - Ischemic preconditioning activates MAPKAPK2 in the isolated rabbit heart:
evidence for involvement of p38 MAPK.
AB - Recent studies suggest that p38 mitogen-activated protein kinase (MAPK) may be
involved in ischemic preconditioning (PC). To further test this possibility, the
regulation of MAPK-activated protein kinase 2 (MAPKAPK2), a kinase immediately
downstream from p38 MAPK, and the activity of c-Jun NH(2)-terminal kinase (JNK),
a second MAPK, were examined in preconditioned hearts. Isolated, perfused rabbit
hearts were subjected to 20 to 30 minutes of global ischemia. Ventricular
biopsies before treatment and after 20 minutes of ischemia were homogenized, and
the activities of MAPKAPK2 and JNK were evaluated. For the MAPKAPK2 experiments,
7 groups were studied, as follows: control hearts; preconditioned hearts; hearts
treated with 500 nmol/L R(-) N(6)-(2-phenylisopropyl) adenosine (PIA), an A(1)
adenosine receptor agonist; preconditioned hearts pretreated with 100 micromol/L
8-(p-sulfophenyl) theophylline (SPT), an adenosine receptor antagonist;
preconditioned hearts also treated with SB 203580, a potent inhibitor of p38 MAPK
activation; hearts treated with 50 ng/mL anisomycin (a p38 MAPK/JNK activator);
and hearts treated with both anisomycin (50 ng/mL) and the tyrosine kinase
inhibitor genistein (50 micromol/L). MAPKAPK2 activity was not altered in control
hearts after 20 minutes of global ischemia. By contrast, there was a 3.8-fold
increase in activity during ischemia in preconditioned hearts. Activation of
MAPKAPK2 in preconditioned hearts was blocked by both SPT and SB 203580. MAPKAPK2
activity during ischemia increased 3.5-fold and 3.3-fold in hearts pretreated
with PIA or anisomycin, respectively. MAPKAPK2 activation during ischemia in
hearts pretreated with anisomycin was blocked by genistein. In separate hearts,
anisomycin mimicked the anti-infarct effect of PC, and that protection was
abolished by genistein. JNK activity was measured in control and preconditioned
hearts. There was a comparable, modest decline in activity during 30 minutes of
global ischemia in both groups. As a positive control, a third group of hearts
was treated with anisomycin before global ischemia, and in these, JNK activity
increased by 290% above baseline. These results confirm that the p38
MAPK/MAPKAPK2 pathway is activated during ischemia only if the heart is in a
preconditioned state. These data further support p38 MAPK as an important
signaling component in ischemic PC.
PMID- 10666410
TI - Direct evidence for increased hydroxyl radicals originating from superoxide in
the failing myocardium.
AB - Experimental and clinical studies have suggested an increased production of
reactive oxygen species (ROS) in the failing myocardium. The present study aimed
to obtain direct evidence for increased ROS and to determine the contribution of
superoxide anion (*O(2)(-)), H(2)O(2), and hydroxy radical (*OH) in failing
myocardial tissue. Heart failure was produced in adult mongrel dogs by rapid
ventricular pacing at 240 bpm for 4 weeks. To assess the production of ROS
directly, freeze-clamped myocardial tissue homogenates were reacted with the
nitroxide radical, 4-hydroxy-2,2,6, 6,-tetramethyl-piperidine-N-oxyl, and its
spin signals were detected by electron spin resonance spectroscopy. The rate of
electron spin resonance signal decay, proportional to *OH level, was
significantly increased in heart failure, which was inhibited by the addition of
dimethylthiourea (*OH scavenger) into the reaction mixture. Increased *OH in the
failing heart was abolished to the same extent in the presence of desferrioxamine
(iron chelator), catalase (H(2)O(2) scavenger), and 4,5-dihydroxy-1,3-benzene
disulfonic acid (Tiron; LaMotte) (*O(2)(-) scavenger), indicating that *OH
originated from H(2)O(2) and *O(2)(-). Further, *O(2)(-) produced in normal
myocardium in the presence of antimycin A (mitochondrial complex III inhibitor)
could reproduce the increase of H(2)O(2) and *OH seen in the failing tissue.
There was a significant positive relation between myocardial ROS level and left
ventricular contractile dysfunction. In conclusion, in the failing myocardium,
*OH was produced as a reactive product of *O(2)(-) and H(2)O(2), which might play
an important role in left ventricular failure.
PMID- 10666411
TI - Endothelin receptor antagonism ameliorates mast cell infiltration, vascular
hypertrophy, and epidermal growth factor expression in experimental diabetes.
AB - Vascular hypertrophy, a feature of experimental and human diabetes, has been
implicated in the pathogenesis of the microvascular and macrovascular
complications of the disease. In the present study, we sought to examine the role
of endogenous endothelin and its relation to vascular growth factors in the
mediation of vascular hypertrophy in experimental diabetes and to examine the
contribution of mast cells to this process. Vessel morphology, endothelin, growth
factor gene expression, and matrix deposition were studied in the mesenteric
arteries of control and streptozotocin-induced diabetic Sprague-Dawley rats
treated with or without the dual endothelin(A/B) receptor antagonist bosentan
(100 mg x kg(-1) x d(-1)) during a 3-week period. Compared with control animals,
diabetic animals had significant increases in vessel weight, wall-to-lumen ratio,
mast cell infiltration, extracellular matrix deposition, and gene expression of
epidermal growth factor (EGF) and transforming growth factor-beta(1). In
diabetic, but not control, vessels, not only were EGF mRNA and endothelin present
in endothelial cells, but also their expression was observed in adventitial mast
cells. Immunoreactive endothelin was present in the media of mesenteric vessels
of diabetic, but not control, animals. Bosentan treatment significantly reduced
mesenteric weight, wall-to-lumen ratio, mast cell infiltration, matrix
deposition, and EGF mRNA but did not prevent the overexpression of transforming
growth factor-beta(1) mRNA in diabetic rats. These findings suggest that
endogenous endothelin and EGF may play a role in diabetes-induced vascular
hypertrophy and that mast cells may be pathogenetically involved in this process.
PMID- 10666412
TI - Antisense intercellular adhesion molecule-1 (ICAM-1) oligodeoxyribonucleotide
delivered during organ preservation inhibits posttransplant ICAM-1 expression and
reduces primary lung isograft failure.
AB - Transiently increased expression of leukocyte adhesion receptors after lung
preservation contributes to early graft demise by recruiting leukocytes,
activating complement, and causing microcirculatory stasis. We hypothesized that
inhibiting intercellular adhesion molecule-1 (ICAM-1) expression even briefly may
significantly improve lung graft function and that the preservation period might
provide a unique window to deliver a therapeutic pulse of antisense
oligonucleotide ICAM-1 to inhibit ICAM-1 expression after transplantation.
Interleukin-1beta-treated rat pulmonary endothelial cells given a 20-mer
phosphorothioate oligonucleotide comprising an antisense span targeted to the 3'
untranslated region of rat ICAM-1 demonstrated an oligonucleotide dose-dependent
reduction in ICAM-1 expression. Using a cationic liposomal carrier, this same
antisense oligonucleotide (but not the sense control) instilled into the
pulmonary vasculature at the time of preservation reduced subsequent graft ICAM-1
expression and graft leukostasis and markedly improved oxygenation, pulmonary
blood flow, and graft survival. These experiments demonstrate that the
preservation period presents a window during which to target an anti-ICAM-1
expression strategy to inhibit early adhesion receptor expression and improve
functional outcome after lung transplantation.
PMID- 10666413
TI - Ca(2+) channel modulation by recombinant auxiliary beta subunits expressed in
young adult heart cells.
AB - L-type Ca(2+) channels contribute importantly to the normal excitation
contraction coupling of physiological hearts, and to the functional derangement
seen in heart failure. Although Ca(2+) channel auxiliary beta(1-4) subunits are
among the strongest modulators of channel properties, little is known about their
role in regulating channel behavior in actual heart cells. Current understanding
draws almost exclusively from heterologous expression of recombinant subunits in
model systems, which may differ from cardiocytes. To study beta-subunit effects
in the cardiac setting, we here used an adenoviral-component gene-delivery
strategy to express recombinant beta subunits in young adult ventricular myocytes
cultured from 4- to 6-week-old rats. The main results were the following. (1) A
component system of replication-deficient adenovirus, poly-L-lysine, and
expression plasmids encoding beta subunits could be optimized to transfect young
adult myocytes with 1% to 10% efficiency. (2) A reporter gene strategy based on
green fluorescent protein (GFP) could be used to identify successfully
transfected cells. Because fusion of GFP to beta subunits altered intrinsic beta
subunit properties, we favored the use of a bicistronic expression plasmid
encoding both GFP and a beta subunit. (3) Despite the heteromultimeric
composition of L-type channels (composed of alpha(1C), beta, and alpha(2)delta),
expression of recombinant beta subunits alone enhanced Ca(2+) channel current
density up to 3- to 4-fold, which argues that beta subunits are "rate limiting"
for expression of current in heart. (4) Overexpression of the putative "cardiac"
beta(2a) subunit more than halved the rate of voltage-dependent inactivation at
+10 mV. This result demonstrates that beta subunits can tune inactivation in the
myocardium and suggests that other beta subunits may be functionally dominant in
the heart. Overall, this study points to the possible therapeutic potential of
beta subunits to ameliorate contractile dysfunction and excitability in heart
failure.
PMID- 10666414
TI - Laminar shear stress inhibits vascular endothelial cell proliferation by inducing
cyclin-dependent kinase inhibitor p21(Sdi1/Cip1/Waf1)
AB - Alterations in the functions of vascular endothelial cells (ECs) induced by fluid
shear stress may play a pivotal role in both the development and prevention of
vascular diseases. We found that DNA synthesis of bovine aortic and human
umbilical vein ECs, determined by [(3)H]thymidine incorporation, was inhibited by
steady laminar shear stress (5 and 30 dyne/cm(2)). This growth inhibition due to
shear stress was associated with suppression of cell transition from the G(1) to
S phase of the cell cycle. Therefore, we studied G(1)-phase events to find the
molecules responsible for this cell cycle arrest. Shear stress inhibited the
phosphorylation of a retinoblastoma protein (pRb) and the activity of cyclin
dependent kinase (cdk) 2 and cdk4, which phosphorylate pRb. The level of cdk
inhibitor p21(Sdi1/Cip1/Waf1) protein, but not that of p27(Kip1), increased as a
result of shear stress, and the amount of p21 protein associated with cdk2 also
increased, although the protein level of cdk2 was unchanged. Shear stress
markedly elevated the mRNA level of p21, and this elevation in mRNA faded after
the release of cells from shear stress, concomitant with a recovery of DNA
synthesis. These results suggest that steady laminar shear stress induces cell
cycle arrest by upregulating p21. Derangement of the steady laminar flow may
release cells from this inhibition and induce cell proliferation, which, in turn,
may cause atherosclerosis through the induction of EC stability disruption.
PMID- 10666415
TI - Pharmacological and immunohistochemical characterization of calmodulin-stimulated
(Ca(2+)+Mg(2+))-ATPase in cultured porcine aortic endothelial cells.
AB - Plasma membrane (Ca(2+)+Mg(2+))-ATPase and Ca(2+) transport activities, best
characterized in human erythrocytes, are stimulated by calmodulin and thought to
play a crucial role in the termination of cellular Ca(2+) signaling in all cells.
In plasma membranes isolated from cultured porcine aortic endothelial cells, the
(Ca(2+)+Mg(2+))-ATPase was not readily measured. This is in part because of an
overabundance of nonspecific Ca(2+)- and/or Mg(2+)-activated ecto-5'-nucleotide
phosphohydrolases. Moreover, addition of exogenous calmodulin (10(-9) to 10(-6)
mol/L) produced no measurable stimulation of ATPase activities, suggesting a
permanently activated state or, alternatively, a complete lack thereof. To
establish and verify the presence of a calmodulin-regulated (Ca(2+)+Mg(2+))
ATPase activity in these endothelial cells, immunohistochemical localization
using a monoclonal mouse anti-(Ca(2+)+Mg(2+))-ATPase antibody (clone 5F10) was
applied to intact pig aorta endothelium, cultured endothelial monolayers, and
isolated endothelial plasma membrane fractions. This approach clearly
demonstrated Ca(2+) pump immunoreactivity in each of these preparations. To
confirm functional calmodulin stimulation of the (Ca(2+)+Mg(2+))-ATPase, 10(-5)
mol/L calmidazolium (R24571) was added to the isolated plasma membrane
preparation, which lowered the (Ca(2+)+Mg(2+))-ATPase activity from 143.0 to
78.15 nmol P(i)/mg protein x min(-1). This calmidazolium-reduced activity could
then be stimulated 113.1+/-0.8% in a concentration-dependent manner by the
addition of exogenous calmodulin (10(-7) to 2 x 10(-6) mol/L) with an EC(50) of
3.45+/-0.04 x 10(-7) mol/L (n=4). This represents a competitive lowering of the
apparent calmodulin affinity by approximately 100 compared with other unopposed
calmodulin-stimulated processes. Together, these findings support evidence for
the presence of a calmodulin-stimulated plasma membrane (Ca(2+)+Mg(2+))-ATPase
activity in cultured porcine aortic endothelial cells.
PMID- 10666416
TI - Rapid activation of neutral sphingomyelinase by hypoxia-reoxygenation of cardiac
myocytes.
AB - Elevated levels of oxygen free radicals have been implicated in the pathways of
reperfusion injury to myocardial tissue. The targets for free radicals may
include specific as well as random intracellular components, and part of the
cellular response is the induction of extracellularly activated and stress
activated kinases. The intermediate signals that initiate these stress responses
are not known. Here we show that one of the earliest responses of cardiac
myocytes to hypoxia and reoxygenation is the activation of neutral
sphingomyelinase and accumulation of ceramide. Ceramide increased abruptly after
reoxygenation, peaking at 10 minutes with 225+/-40% of the control level. Neutral
sphingomyelinase activity was induced with similar kinetics, and both activities
remained elevated for several hours. c-Jun N-terminal kinase (JNK) was also
activated within the same time frame. Treatment of cardiac myocytes with
extracellular ceramides also activated JNK. Pretreating cells with antioxidants
quenched sphingomyelinase activation, ceramide accumulation, and JNK activation.
Ceramide did not accumulate in reoxygenated nonmuscle fibroblasts, and JNK was
not activated by reoxygenation in these cells. The results identify neutral
sphingomyelinase activation as one of the earliest responses of cardiac myocytes
to the redox stress imposed by hypoxia-reoxygenation. The results are consistent
with a pathway of ceramide-mediated activation of JNK.
PMID- 10666417
TI - T-lymphocyte-derived tumor necrosis factor exacerbates anoxia-reoxygenation
induced neutrophil-endothelial cell adhesion.
AB - The overall objective of this study was to determine whether T lymphocytes can
modulate the increased neutrophil adherence and upregulation of endothelial cell
adhesion molecules in human umbilical vein endothelial cells (HUVECs) exposed to
anoxia/reoxygenation (A/R). HUVEC monolayers were exposed to 60 minutes of
anoxia, followed by 4 hours of reoxygenation in the absence or presence of human
T lymphocytes. The A/R-induced neutrophil adhesion was significantly enhanced
when T lymphocytes and HUVECs were cocultured for the first 45 minutes of
reoxygenation. This was accompanied by a more pronounced increase in E-selectin
expression. When T lymphocytes were cocultured with HUVECs by use of inserts that
prevented direct cell-cell contact, a comparable A/R-induced enhancement of
neutrophil adhesion and of E-selectin expression was observed, indicating that
soluble factors produced by T lymphocytes mediate the exaggerated A/R-induced
inflammatory responses. Treatment with either an anti-tumor necrosis factor-alpha
antibody or catalase attenuated the T-cell-mediated responses in postanoxic
HUVECs. Moreover, the T-cell-mediated neutrophil adhesion response was mimicked
by exposure of naive HUVECs to H(2)O(2). These findings indicate that H(2)O(2)
produced by postanoxic endothelial cells stimulates T cells to produce tumor
necrosis factor-alpha, which in turn elicits endothelial cell adhesion molecule
expression and a corresponding increase in neutrophil adhesion.
PMID- 10666418
TI - Roles of mitogen-activated protein kinases and protein kinase C in alpha(1A)
adrenoceptor-mediated stimulation of the sarcolemmal Na(+)-H(+) exchanger.
AB - Activation of the sarcolemmal Na(+)-H(+) exchanger (NHE) has been implicated as a
mechanism of inotropic, arrhythmogenic, antiacidotic, and hypertrophic effects of
alpha(1)-adrenoceptor (AR) stimulation. Although such regulation of sarcolemmal
NHE activity has been shown to be selectively mediated through the alpha(1A)-AR
subtype, distal signaling mechanisms remain poorly defined. We investigated the
roles of various kinase pathways in alpha(1A)-AR-mediated stimulation of
sarcolemmal NHE activity in adult rat ventricular myocytes. As an index of NHE
activity, trans-sarcolemmal acid efflux rate (J(H)) was determined through
microepifluorescence in single cells, during recovery from intracellular acidosis
in bicarbonate-free conditions. Extracellular signal-regulated kinase (ERK), p38
mitogen-activated protein kinase (MAPK), and p90(rsk) activities were indexed on
the basis of analysis of their phosphorylation status. In control cells, there
was no change in J(H) in response to vehicle. Phenylephrine and A61603, an
alpha(1A)-AR subtype-selective agonist, increased J(H), as well as cellular ERK
and p90(rsk) activities. Neither agonist affected p38 activity, which was
increased with sorbitol. The MAPK kinase inhibitor PD98059 abolished
phenylephrine- and A61603-induced increases in J(H) and cellular ERK and p90(rsk)
activities. In contrast, the PKC inhibitor GF109203X abolished phenylephrine- and
A61603-induced increases in J(H) but failed to prevent the increases in ERK and
p90(rsk) activities. Our findings suggest that alpha(1A)-AR-mediated stimulation
of sarcolemmal NHE activity in rat ventricular myocytes requires activation of
the ERK (but not the p38) pathway of the MAPK cascade and that the ERK-mediated
effect may occur via p90(rsk). Activation of PKC is also required for alpha(1A)
AR-mediated NHE stimulation, but such regulation occurs through an ERK
independent pathway.
PMID- 10666419
TI - Smooth muscle alpha-actin CArG elements coordinate formation of a smooth muscle
cell-selective, serum response factor-containing activation complex.
AB - Previous studies have shown that multiple serum response factor (SRF)-binding
CArG elements were required for smooth muscle cell (SMC)-specific regulation of
smooth muscle (SM) alpha-actin expression. However, a critical question remains
as to the mechanisms whereby a ubiquitously expressed transcription factor such
as SRF might contribute to SMC-specific expression. The goal of the present study
was to investigate the hypothesis that SMC-selective expression of SM alpha-actin
is due at least in part to (1) unique CArG flanking sequences that distinguish
the SM alpha-actin CArGs from other ubiquitously expressed CArG-dependent genes
such as c-fos, (2) cooperative interactions between CArG elements, and (3) SRF
dependent binding of SMC-selective proteins to the CArG-containing regions of the
promoter. Results demonstrated that specific sequences flanking CArG B were
important for promoter activity in SMCs but not in bovine aortic endothelial
cells. We also provided evidence indicating that the structural orientation
between CArGs A and B was an important determinant of promoter function.
Electrophoretic mobility shift assays and methylation interference footprinting
demonstrated that a unique SRF-containing complex formed that was selective for
SMCs and, furthermore, that this complex was probably stabilized by protein
protein interactions and not by specific interactions with CArG flanking
sequences. Taken together, the results of these studies provide evidence that SM
alpha-actin expression in SMCs is complex and may involve the formation of a
unique multiprotein initiation complex that is coordinated by SRF complexes bound
to multiple CArG elements.
PMID- 10666420
TI - Interferon-gamma induces AT(2) receptor expression in fibroblasts by Jak/STAT
pathway and interferon regulatory factor-1.
AB - The expression of angiotensin II type 2 (AT(2)) receptor is closely associated
with cell growth, differentiation, and/or injury. We examined the effect of
interferon (IFN)-gamma on AT(2) receptor expression in mouse fibroblast R3T3
cells and demonstrated that IFN-gamma treatment increased the expression of AT(2)
receptor mRNA as well as its binding. Interferon regulatory factor (IRF)-1 was
induced in mouse fibroblast R3T3 cells after IFN-gamma stimulation, and
electrophoretic mobility shift assay showed an increase in IRF-1 binding with the
IRF-specific binding sequence in the AT(2) receptor gene promoter region after
IFN-gamma stimulation. The IRF-1 gene promoter contains an IFN-gamma-activated
sequence (GAS) motif for possible binding of signal transducer(s) and
activator(s) of transcription (STAT). Indeed, in R3T3 cells, IFN-gamma treatment
resulted in rapid activation of Janus kinase (Jak) 1, Jak2, and STAT1 via
tyrosine phosphorylation. Electrophoretic mobility shift assay with the GAS probe
revealed increased STAT1 binding to the IRF-1 gene promoter in response to IFN
gamma stimulation. Transfection of GAS-binding oligonucleotides inhibited the
effect of IFN-gamma on IRF-1 production, resulting in the AT(2) receptor trans
activation. Taken together, our data show that IFN-gamma upregulates AT(2)
receptor expression in R3T3 cells via the activation of the intracellular
Jak/STAT pathway and production of IRF-1.
PMID- 10666421
TI - Influence of a perfusing bath on the foot of the cardiac action potential.
AB - Recently, Spach et al (Circ Res. 1998;83:1144-1164) measured the transmembrane
action potential 150 to 200 microm below the tissue surface during longitudinal
and transverse propagation. They found that "during longitudinal propagation
there was initial slowing of V(m) [action potential] foot that resulted in
deviations from a simple exponential. " (p 1144). They attributed this behavior
to the effects of capillaries on propagation. The purpose of this commentary is
to show that the perfusing bath plays an important role in determining the time
course of the action potential foot, even when the transmembrane potential is
measured 150 microm below the tissue surface. Using numerical simulations based
on the bidomain model, we find that the action potential foot for transverse
propagation is nearly exponential (tau(foot)=314 micros). For longitudinal
propagation, the action potential foot is not exponential because of an initial
slowing (best-fit tau(foot)=483 micros). We conclude that the perfusing bath must
be taken into account when interpreting data showing differences in the shape of
the action potential foot with propagation direction, even if the transmembrane
potential is measured 150 microm below the tissue surface.
PMID- 10666422
TI - Effects of cardiac microstructure on propagating electrical waveforms
AB - Electrical waveforms measured during propagation at microscopic level are
considerably affected by normal variations in cardiac microstructure as well as
by the superfusing fluid. On the basis of evidence we present in this article, we
argue that the anisotropic waveform variations discussed here are explained
primarily by the associated variations in different microstructural components of
myocardial architecture rather than by the effects of the perfusing bath. The
results suggest that different components of myocardial architecture have
preferential effects on f1.gif" BORDER="0">(max) and on the shape of the foot of
the transmembrane action potential (V(m) foot). Resistive discontinuities
primarily affect f1.gif" BORDER="0">(max), and an additional capacitive component
in the local circuit due to the capillaries in interstitial space primarily
affects V(m) foot. Resistive discontinuities also have an important influence on
cardiac conduction. These discontinuities include spatial variations in the size
of interstitial space (interstitial resistive discontinuities) and the role of
cellular scaling (effects of cell size) when changes occur in the cellular and
multicellular distribution of gap junctions during remodeling of normal mature
myocardium to proarrhythmic structural substrates. The full text of this article
is available at http://www.circresaha.org.
PMID- 10666423
TI - Mice lacking the vascular endothelial growth factor-B gene (Vegfb) have smaller
hearts, dysfunctional coronary vasculature, and impaired recovery from cardiac
ischemia.
AB - Vascular endothelial growth factor-B (VEGF-B) is closely related to VEGF-A, an
effector of blood vessel growth during development and disease and a strong
candidate for angiogenic therapies. To further study the in vivo function of VEGF
B, we have generated Vegfb knockout mice (Vegfb(-/-)). Unlike Vegfa knockout
mice, which die during embryogenesis, Vegfb(-/-) mice are healthy and fertile.
Despite appearing overtly normal, Vegfb(-/-) hearts are reduced in size and
display vascular dysfunction after coronary occlusion and impaired recovery from
experimentally induced myocardial ischemia. These findings reveal a role for VEGF
B in the development or function of coronary vasculature and suggest potential
clinical use in therapeutic angiogenesis.
PMID- 10666424
TI - Tetrahydrobiopterin improves endothelium-dependent vasodilation in chronic
smokers : evidence for a dysfunctional nitric oxide synthase.
AB - Conditions associated with impaired nitric oxide (NO) activity and accelerated
atherosclerosis have been shown to be associated with a reduced bioavailability
of tetrahydrobiopterin (BH4). We therefore hypothesized that BH4 supplementation
may improve endothelial dysfunction of chronic smokers. Forearm blood flow (FBF)
responses to the endothelium-dependent vasodilators acetylcholine (ACh; 0.75,
1.5, and 3.0 microg/100 mL tissue/min) or serotonin (5-HT; 0.7, 2.1, and 6.3
ng/100 mL tissue/min), to the inhibitor of endothelial nitric oxide synthase
(NOS) N(G)-monomethyl-L-arginine (L-NMMA; 2, 4, and 8 micromol/min), and to the
endothelium-independent vasodilator sodium nitroprusside (SNP; 0.1, 0.3, and 1.0
microg/100 mL tissue/min) were measured by venous occlusion plethysmography in
controls and chronic smokers. Drugs were infused into the brachial artery, and
FBF was measured before and during concomitant intra-arterial infusion of BH4,
tetrahydroneopterin (NH4; another reduced pteridine), or the antioxidant vitamin
C (6 and 18 mg/min). In control subjects, BH4 had no effect on FBF in response to
ACh, 5-HT, and SNP. In contrast, in chronic smokers, the attenuated FBF responses
to ACh and 5-HT were markedly improved by concomitant administration of BH4,
whereas the vasodilator responses to SNP were not affected. L-NMMA-induced
vasoconstriction was significantly reduced in smokers compared with controls,
suggesting impaired basal NO bioactivity. BH4 improved L-NMMA responses in
smokers while having no effect on L-NMMA responses in controls. Pretreatment with
vitamin C abolished BH4 effects on ACh-dependent vasodilation. In vitro, NH4
scavenged superoxide created by the xanthine/xanthine oxidase reaction equipotent
like BH4 but failed to modify ACh-induced changes in FBF in chronic smokers in
vivo. These data support the concept that in addition to the free radical burden
of cigarette smoke, a dysfunctional NOS III due to BH4 depletion may contribute
at least in part to endothelial dysfunction in chronic smokers.
PMID- 10666425
TI - Formation of heterotypic gap junction channels by connexins 40 and 43.
AB - Gap junctions formed between transfected cells expressing connexin (Cx) 40 and
Cx43 (Cx43-RIN, Cx40-HeLa, and Cx43-HeLa) revealed a relationship, g(j)=f(V(j)),
at steady state, that is typified by a nonsymmetrical behavior similar to that
previously reported for other heterotypic channels (gap junction conductance
[g(j)]; transjunctional voltage [V(j)]). The unitary conductance of the channels
was sensitive to the polarity of V(j). A main state conductance of 61 pS was
found when the Cx43 cell was stepped positively or the Cx40 cell negatively
(V(j)=70 mV); the reverse polarities yielded a conductance of 100 pS. These
heterotypic channels were permeable to carboxyfluorescein. In addition, two other
heterotypic forms are illustrated to demonstrate that endogenous Cx45 expression
cannot explain the results. The demonstration of heterotypic Cx40-Cx43 channels
may have implications for the propagation of the electrical impulse in heart. For
example, they may contribute to the slowing of the impulse propagation through
the junctions between Purkinje fibers and ventricular muscle.
PMID- 10666426
TI - Efficacy of implantable cardioverter-defibrillators for the prevention of sudden
death in patients with hypertrophic cardiomyopathy.
AB - BACKGROUND: Hypertrophic cardiomyopathy is a genetic disease associated with a
risk of ventricular tachyarrhythmias and sudden death, especially in young
patients. METHODS: We conducted a retrospective multicenter study of the efficacy
of implantable cardioverter-defibrillators in preventing sudden death in 128
patients with hypertrophic cardiomyopathy who were judged to be at high risk for
sudden death. RESULTS: At the time of the implantation of the defibrillator, the
patients were 8 to 82 years old (mean [+/-SD], 40+/-16), and 69 patients (54
percent) were less than 41 years old. The average follow-up period was 3.1 years.
Defibrillators were activated appropriately in 29 patients (23 percent), by
providing defibrillation shocks or antitachycardia pacing, with the restoration
of sinus rhythm; the average age at the time of the intervention was 41 years.
The rate of appropriate defibrillator discharge was 7 percent per year. A total
of 32 patients (25 percent) had episodes of inappropriate discharges. In the
group of 43 patients who received defibrillators for secondary prevention (after
cardiac arrest or sustained ventricular tachycardia), the devices were activated
appropriately in 19 patients (11 percent per year). Of 85 patients who had
prophylactic implants because of risk factors (i.e., for primary prevention), 10
had appropriate interventions (5 percent per year). The interval between
implantation and the first appropriate discharge was highly variable but was
substantially prolonged (four to nine years) in six patients. In all 21 patients
with stored electrographic data and appropriate interventions, the interventions
were triggered by ventricular tachycardia or fibrillation. CONCLUSIONS:
Ventricular tachycardia or fibrillation appears to be the principal mechanism of
sudden death in patients with hypertrophic cardiomyopathy. In high-risk patients
with hypertrophic cardiomyopathy, implantable defibrillators are highly effective
in terminating such arrhythmias, indicating that these devices have a role in the
primary and secondary prevention of sudden death.
PMID- 10666427
TI - Prothrombin and factor V mutations in women with a history of thrombosis during
pregnancy and the puerperium.
AB - BACKGROUND: Venous thromboembolism is a leading cause of morbidity and mortality
during pregnancy and the puerperium. However, the role of mutations in the
prothrombin and factor V genes and other thrombophilic abnormalities as risk
factors for thromboembolism in women during pregnancy and the pueperium is not
known. METHODS: In a study of 119 women with a history of venous thromboembolism
during pregnancy and the puerperium and 233 age-matched normal women, we measured
the activity of antithrombin, protein C, protein S, and lupus anticoagulant. We
also performed genetic analyses to detect the G1691A mutation in the factor V
gene (factor V Leiden), the G20210A mutation in the prothrombin gene, and the
C677T mutation in the methylenetetrahydrofolate reductase gene. Blood samples
were obtained at least three months post partum or after the cessation of
lactation. RESULTS: Among the women with a history of venous thromboembolism, the
prevalence of factor V Leiden was 43.7 percent, as compared with 7.7 percent
among the normal women (relative risk of venous thromboembolism, 9.3; 95 percent
confidence interval, 5.1 to 16.9); that of the G20210A prothrombin-gene mutation,
16.9 percent as compared with 1.3 percent (relative risk, 15.2; 95 percent
confidence interval, 4.2 to 52.6); and that of both factor V Leiden and the
G20210A prothrombin-gene mutation 9.3 percent as compared with 0 (estimated odds
ratio, 107). Assuming an overall risk of 1 in 1500 pregnancies, the risk of
thrombosis among carriers of factor V Leiden was 0.2 percent, among carriers of
the G20210A prothrombin-gene mutation, 0.5 percent, and among carriers of both
defects, 4.6 percent, as calculated in a multivariate analysis. CONCLUSIONS: The
G20210A prothrombin-gene mutation and factor V Leiden individually are associated
with an increased risk of venous thromboembolism during pregnancy and the
puerperium, and the risk among women with both mutations is disproportionately
higher than that among women with only one mutation.
PMID- 10666428
TI - Retinopathy and nephropathy in patients with type 1 diabetes four years after a
trial of intensive therapy.
AB - BACKGROUND: Among patients with type 1 diabetes mellitus, intensive therapy (with
the aim of achieving near-normal blood glucose and glycosylated hemoglobin
concentrations [hemoglobin A1c]) markedly reduces the risk of microvascular
complications as compared with conventional therapy. To assess whether these
benefits persist, we compared the effects of former and intensive conventional
therapy on the recurrence and severity of retinopathy and nephropathy for four
years after the end of the Diabetes Control and Complications Trial (DCCT).
METHODS: At the end of the DCCT, the patients in the conventional-therapy group
were offered intensive therapy, and the care of all patients was transferred to
their own physicians. Retinopathy was evaluated on the basis of centrally graded
fundus photographs in 1208 patients during the fourth year after the DCCT ended,
and nephropathy was evaluated on the basis of urine specimens obtained from 1302
patients during the third or fourth year, approximately half of whom were from
each treatment group. RESULTS: The difference in the median glycosylated
hemoglobin values between the conventional-therapy and intensive-therapy groups
during the 6.5 years of the DCCT (average, 9.1 percent and 7.2 percent,
respectively) narrowed during follow-up (median during 4 years, 8.2 percent and
7.9 percent, respectively, P<0.001). Nevertheless, the proportion of patients who
had worsening retinopathy, including proliferative retinopathy, macular edema,
and the need for laser therapy, was lower in the intensive-therapy group than in
the conventional-therapy group (odds reduction, 72 percent to 87 percent,
P<0.001). The proportion of patients with an increase in urinary albumin
excretion was significantly lower in the intensive-therapy group. CONCLUSIONS:
The reduction in the risk of progressive retinopathy and nephropathy resulting
from intensive therapy in patients with type 1 diabetes persists for at least
four years, despite increasing hyperglycemia.
PMID- 10666429
TI - Asymptomatic carriage of Clostridium difficile and serum levels of IgG antibody
against toxin A.
AB - BACKGROUND: Clostridium difficile infection can result in asymptomatic carriage,
mild diarrhea, or fulminant pseudomembranous colitis. We studied whether antibody
responses to C. difficile toxins affect the risks of colonization, diarrhea, and
asymptomatic carriage. METHODS: We prospectively studied C. difficile infections
in hospitalized patients who were receiving antibiotics. Serial stool samples
were tested for C. difficile colonization by cytotoxin assay and culture. Serum
antibody (IgA, IgG, and IgM) levels and fecal antibody (IgA and IgG) levels
against C. difficile toxin A, toxin B, and nontoxin antigens were measured by an
enzyme-linked immunosorbent assay (ELISA). RESULTS: Of 271 patients, 37 (14
percent) were colonized with C. difficile at the time of admission, 18 of whom
were asymptomatic carriers. An additional 47 patients (17 percent) became
infected in the hospital, 19 of whom remained asymptomatic. The baseline antibody
levels were similar in the patients who later became colonized and those who did
not. After colonization, those who became asymptomatic carriers had significantly
greater increases in serum levels of IgG antibody against toxin A than did the
patients in whom C. difficile diarrhea developed (P<0.001). The adjusted odds
ratio for diarrhea was 48.0 (95 percent confidence interval, 3.4 to 678) among
patients with colonization who had a serum level of IgG antibody against toxin A
of 3.00 ELISA units or less, as compared with patients with colonization who had
a level of more than 3.00 ELISA units. CONCLUSIONS: We find no evidence of immune
protection against colonization by C. difficile. However, after colonization
there is an association between a systemic anamnestic response to toxin A, as
evidenced by increased serum levels of IgG antibody against toxin A, and
asymptomatic carriage of C. difficile.
PMID- 10666430
TI - Images in clinical medicine. Internal ventricular defibrillation.
PMID- 10666431
TI - Women physicians in academic medicine: new insights from cohort studies.
AB - BACKGROUND: I conducted a study to determine whether women who graduate from
medical schools are more or less likely than their male counterparts to pursue
full-time careers in academic medicine and to advance to the senior ranks of
medical school faculties. METHODS: The rates of advancement to the ranks of
assistant, associate, and full professor for all U.S. medical school graduates
from 1979 through 1993 and for all members of U.S. medical school faculties from
1979 through 1997 were studied. Cohorts were defined on the basis of the year of
graduation from medical school, track (tenure or nontenure), and academic
department. Within each cohort, the number of women who advanced to a senior rank
was compared with the number that would be expected on the basis of parity
between men and women, and 95 percent confidence intervals were calculated.
RESULTS: Women were significantly more likely than men to pursue an academic
career. During the study period, 634 more women became faculty members than
expected. The numbers were higher in the older cohorts than in the younger
cohorts. The numbers of women who advanced to the ranks of associate and full
professor were significantly lower than the expected numbers. This was true for
both tenure and nontenure tracks, even after adjustment for the department. A
total of 334 fewer women advanced to associate professor than expected, and 44
fewer women advanced to full professor than expected. CONCLUSIONS: Disparities
persist in the advancement of men and women on medical school faculties. However,
the numbers of women physicians at all levels of academic medicine are
increasing.
PMID- 10666432
TI - Occupational respiratory diseases.
PMID- 10666433
TI - Case records of the Massachusetts General Hospital. Weekly clinicopathological
exercises. Case 4-2000. A 64-year-old man with Cushing's syndrome and a
pancreatic mass.
PMID- 10666434
TI - Sudden death in hypertrophic cardiomyopathy.
PMID- 10666435
TI - The challenge of thrombophilia in maternal-fetal medicine.
PMID- 10666436
TI - Women in academic medicine: new insights, same sad news.
PMID- 10666437
TI - Collective bargaining is the right step.
PMID- 10666438
TI - White coats should not have union labels.
PMID- 10666440
TI - Correction: Looking Back on the Millennium in Medicine.
PMID- 10666439
TI - Correction: Canterbury Cathedral.
PMID- 10666442
TI - A novel RNA-binding protein from Triturus carnifex identified by RNA-ligand
screening with the newt hammerhead ribozyme.
AB - The newt hammerhead ribozyme is transcribed from Satellite 2 DNA, which consists
of tandemly repeated units of 330 bp. However, different transcripts are
synthesized in different tissues. In all somatic tissues and in testes, dimeric
and multimeric RNA transcripts are generated which, to some extent, self-cleave
into monomers at the hammerhead domain. In ovaries, primarily a distinct
monomeric unit is formed by transcription, which retains an intact hammerhead
self-cleavage site. The ovarian monomeric RNA associates to form a 12S complex
with proteins that are poorly characterised so far. In this work we identified
NORA, a protein that binds the ovarian form of the newt ribozyme. We show that
the newt ribozyme binds to the Escherichia coli -expressed protein, as well as to
a protein of identical size that is found exclusively in newt ovaries. Also NORA
mRNA was detectable only in ovary, but in neither somatic tissues nor testes. The
tissue-specific expression of NORA is analogous to the ovary-specific
transcription of the newt ribozyme. Although NORA was identified by its ability
to bind to the newt ribozyme in the presence of a vast excess of carrier RNA, it
was able to interact with certain other RNA probes. This novel RNA-binding
protein does not contain any motif characteristic for RNA-binding proteins or any
other known protein domain, but it shares a striking similarity with a rat
resiniferatoxin-binding protein.
PMID- 10666443
TI - MethTools--a toolbox to visualize and analyze DNA methylation data.
AB - The Bisulfite Genomic Sequencing technique has found wide acceptance for the
generation of DNA-methylation maps with single-base resolution. The method is
based on the selective deamination of cytosine to uracil (and subsequent
conversion to thymine via PCR), whereas 5-methylcytosine residues remain
unchanged. Methylation maps are created by the comparison of bisulfite converted
sequences with the untreated genomic sequence. 'MethTools' is a collection of
software tools that replaces the time-consuming manual comparison process,
generates graphical outputs of methylation patterns and methyl-ation density,
estimates the systematic error of the experiment and searches for conserved
methylated nucleotide patterns. The programs are written in Perl 5 and C, and the
source code can be downloaded. All tools run independently but the programs are
interfaced. Thus, a script can perform the entire analysis procedure
automatically. In addition, a web-based remote analysis service is offered. Both
the source code and the remote analysis are available at http://genome.imb
jena.de/methtools/
PMID- 10666444
TI - Improving dideoxynucleotide-triphosphate utilisation by the hyper-thermophilic
DNA polymerase from the archaeon Pyrococcus furiosus.
AB - Polymerases from the Pol-I family which are able to efficiently use ddNTPs have
demonstrated a much improved performance when used to sequence DNA. A number of
mutations have been made to the gene coding for the Pol-II family DNA polymerase
from the archaeon Pyrococcus furiosus with the aim of improving ddNTP
utilisation. 'Rational' alterations to amino acids likely to be near the dNTP
binding site (based on sequence homologies and structural information) did not
yield the desired level of selectivity for ddNTPs. However, alteration at four
positions (Q472, A486, L490 and Y497) gave rise to variants which incorporated
ddNTPs better than the wild type, allowing sequencing reactions to be carried out
at lowered ddNTP:dNTP ratios. Wild-type Pfu-Pol required a ddNTP:dNTP ratio of
30:1; values of 5:1 (Q472H), 1:3 (L490W), 1:5 (A486Y) and 5:1 (Y497A) were found
with the four mutants; A486Y representing a 150-fold improvement over the wild
type. A486, L490 and Y497 are on analpha-helix that lines the dNTP binding
groove, but the side chains of the three amino acids point away from this groove;
Q472 is in a loop that connects this alpha-helix to a second long helix. None of
the four amino acids can contact the dNTP directly. Therefore, the increased
selectivity for ddNTPs is likely to arise from two factors: (i) small overall
changes in conformation that subtly alter the nucleotide triphosphate binding
site such that ddNTPs become favoured; (ii) interference with a conformational
change that may be critical both for the polymerisation step and discrimination
between different nucleotide triphosphates.
PMID- 10666445
TI - A simple in vitro Tn7-based transposition system with low target site selectivity
for genome and gene analysis.
AB - A robust Tn7-based in vitro transposition system is described that displays
little target site selectivity, allowing the efficient recovery of many different
transposon insertions in target DNAs ranging from small plasmids to cosmids to
whole genomes. Two miniTn7 derivatives are described that are useful for the
analysis of genes: one a derivative for making translational and transcriptional
target gene fusions and the other a derivative that can generate 15 bp (5 amino
acid) insertions in target DNAs (proteins).
PMID- 10666446
TI - Genetic analysis of a La homolog in Drosophila melanogaster.
AB - People afflicted with certain rheumatological auto-immune diseases produce
autoantibodies directed against a select group of proteins such as the La auto
antigen. Biochemical studies have revealed La to be a promiscuous RNA-binding
protein that appears to play a role in a variety of intracellular activities such
as processing and/or transport of RNA polymerase III precursor transcripts and
translational regulation from internal ribosome entry sites (IRES). We have
previously identified an RNA-binding protein that is a Drosophila melanogaster
homolog of La (D-La) and shown that early transcript accumulation throughout the
embryo is later refined to be most prevalent in the visceral mesoderm, gut,
gonads and salivary glands. Here we report the first in vivo genetic
characterization of a La homolog in a multicellular eukaryote. Lethality was
observed in homozygous larvae harboring a small chromosomal deletion that removed
the D-La gene, which was rescued by an inducible D-La cDNA transgene. This
implies that D-La confers essential functions for larval development. In
addition, loss of D-La function gives rise to defects in embryonic midgut
morphogenesis; one of the midgut defects correlates with loss of Ultrabithorax (
Ubx ) expression along the second midgut constriction. Finally, genetic
interactions between chromosomal deficiencies that remove D-La and certain Ubx
alleles were demonstrated in adults. Our results support the hypothesis that D-La
provides essential functions for proper Drosophila development and imply that the
conserved La family of proteins may perform critical developmental functions in
higher eukaryotes.
PMID- 10666447
TI - Identification of a base-specific contact between the restriction endonuclease
SsoII and its recognition sequence by photocross-linking.
AB - A target sequence-specific DNA binding region of the restriction endonuclease Sso
II was identified by photocross-linking with an oligodeoxynucleotide duplex which
was substituted with 5-iododeoxy-uridine (5-IdU) at the central position of the
Sso II recognition site (CCNGG). For this purpose the Sso II-DNA complex was
irradiated with a helium/cadmium laser (325 nm). The cross-linking yield obtained
was approximately 50%. In the presence of excess unmodified oligodeoxynucleotide
or with oligode-oxynucleotides substituted with 5-IdU elsewhere, no cross-linking
was observed, indicating the specificity of the cross-linking reaction. The cross
linked Sso II-oligodeoxynucleotide complex was digested with chymotrypsin, a
cross-linked peptide-oligodeoxy-nucleotide complex isolated and the site of cross
linking identified by Edman sequencing to be Trp61. In line with this
identification is the finding that the W61A variant cannot be cross-linked with
the IdU-substituted oligodeoxynucleotide, shows a decrease in affinity towards
DNA and is inactive in cleavage. It is concluded that the region around Trp61 is
involved in specific binding of Sso II to its DNA substrate.
PMID- 10666448
TI - Transcripts of the ndhH-D operon of barley plastids: possible role of unedited
site III in splicing of the ndhA intron.
AB - The plastid ndhH-D operon produces several transcripts containing ndhA sequence
with and without its group II intron. After sequencing an 8125 bp fragment of
barley plastid DNA including the ndhH-D operon, we investigated the editing
splicing status of transcripts in the range 1.0-7.8 kb. Reverse transcription and
sequencing of RNA bands separated by electrophoresis were used to determine C-->U
editing sites. Sites I, II and IV of ndhA and site V of ndhD were edited in all
transcripts analysed and, probably, were edited before any splicing had taken
place. In contrast, site III of ndhA (13 bp from the 5'-end base of the second
exon) was not edited in transcripts containing the intron (including the 1.7 kb
intermediary transcript consisting of the intron and the second exon) but was
edited in all transcripts lacking the ndhA intron. Comparison of the secondary
structures of the ndhA intron and intron-second exon intermediate suggests that G
pairing prevents editing of site III in transcripts containing the intron and
maintains the secondary structure required for splicing. Splicing of the ndhA
intron releases the site III C from pairing and, probably, brings it close to cis
acting elements for editing upstream in the first exon.
PMID- 10666449
TI - An 'environment to nucleus' signaling system operates in B lymphocytes: redox
status modulates BSAP/Pax-5 activation through Ref-1 nuclear translocation.
AB - The Ref-1 (also called APE or HAP1) protein is a bifunctional enzyme impacting on
a wide variety of important cellular functions. It acts as a major member of the
DNA base excision repair pathway. Moreover, Ref-1 stimulates the DNA-binding
activity of several transcription factors (TFs) through the reduction of highly
reactive cysteine residues. Therefore, it represents a mechanism that regulates
eukaryotic gene expression in a fast way. However, it has been demonstrated that
external stimuli directly act on Ref-1 by increasing its expression levels, a
time-consuming mechanism representing a paradox in terms of rapidity of TF
regulation. In this paper we demonstrate that this is only an apparent paradox.
Exposure of B lymphocytes to H(2)O(2)induced a rapid and sustained increase in
Ref-1 protein levels in the nucleus as evaluated by both western blot analysis
and by pulse-chase experiments. A time course, two color in situ
immunocytochemistry indicated that the up-regulation of Ref-1 in the nucleus at
<30 min was primarily the consequence of translocation of its cytoplasmic form.
This early nuclear accumulation is effective in modulating the DNA-binding
activity of the B cell-specific activator protein BSAP/Pax-5. In fact, EMSA
experiments demonstrate that a transient interaction with Ref-1 up-regulates the
DNA-binding activity of BSAP/Pax-5. Moreover, in a co-transfection experiment,
Ref-1 increased the BSAP/Pax-5 activating effect on an oligomerized BSAP/Pax-5
binding site of the CD19 promoter by 5- to 8-fold. Thus, Ref-1 mediates its
effect by up-regulating the DNA-binding activity of BSAP/Pax-5, accounting for a
new and fast outside/inside pathway of signaling in B cells.
PMID- 10666450
TI - Transactivation and growth suppression by the gut-enriched Kruppel-like factor
(Kruppel-like factor 4) are dependent on acidic amino acid residues and protein
protein interaction.
AB - Gut-enriched Kruppel-like factor (GKLF or KLF4) is a pleiotropic (activating and
repressive) transcription factor. This study characterizes the mechanisms of
transactivation by GKLF. Using a GAL4 fusion assay, the activating domain of
murine GKLF was localized to the 109 amino acid residues in the N-terminus. Site
directed mutagenesis showed that two adjacent clusters of acidic residues within
this region are responsible for the activating effect. Transactivation by GKLF
involves intermolecular interactions as demonstrated by the ability of wild-type,
but not mutated, GKLF to compete with the N-terminal activation domain. In
addition, wild-type adenovirus E1A, but not a mutated E1A that failed to bind
p300/CBP, inhibited transactivation by the N-terminal 109 amino acids of GKLF,
suggesting that p300/CBP are GKLF's interacting partners. A physical interaction
between GKLF and CBP was demonstrated by glutathione- S -transferase pull-down
and by in vivo co-immuno-precipitation experiments. We also showed that the two
acidic amino acid clusters are essential for this interaction, since GKLF with
mutations in these residues failed to co-immunoprecipitate with CBP. Importantly,
the same mutations abrogated the ability of GKLF to suppress cell growth as
determined by a colony suppression assay. These studies therefore provide
plausible evidence for a structural and functional correlation between the
transactivating and growth-suppressing effects of GKLF.
PMID- 10666451
TI - Excision repair at the level of the nucleotide in the upstream control region,
the coding sequence and in the region where transcription terminates of the
Saccharomyces cerevisiae MFA2 gene and the role of RAD26.
AB - RAD26, the yeast homologue of human CSB, has an essential role in transcription
coupled repair (TCR). We have mapped the requisite of Rad26 for nucleotide
excision repair (NER) within the different regions of the yeast Saccharomyces
cerevisiae MFA2 gene at nucleotide resolution. Our results show that Rad26 is
dispensable for enhanced NER in both the MFA2 upstream promoter, except in the
TATA box region, and for enhanced NER in both strands of the active gene at a
site close to the transcription termination region. As expected, it is not needed
for repair of regions downstream of where transcription terminates. However, it
is required for TCR in the transcription initiation and elongation regions. Our
data support the hypothesis that Rad26 is required for the interchange between
holo-TFIIH and a putative repairosome containing core TFIIH and other NER
proteins. Close to the end of transcription, hotspots for the repair of CPDs in
both the transcribed strand and the non-transcribed strand occur. This enhanced
repair is independent of Rad26. Hence, TFIIH may take a form favourable for
forming a repairosome without Rad26 assistance; here the organisation of the DNA
during the termination of transcription may facilitate access of a repair complex
to enable enhanced repair of both strands.
PMID- 10666452
TI - The tetracycline-responsive promoter contains functional interferon-inducible
response elements.
AB - Tetracycline (tet)-responsive expression vectors allow controlled inducible
expression of proteins in mammalian cells. This system is widely used for
experimental research both in vivo and in vitro. In our attempts to use this
system to study the antiviral effect of IFNalpha on hepatitis B virus, we
discovered an unexpected feature of the tet-responsive promoter (tet promoter) of
the currently available expression vectors. IFNalphawas found to stimulate tet
promoter activity after transient transfection in a dose- and cell type-dependent
manner. By sequence inspection, an IFNalpha-stimulated response element (ISRE)
like sequence was identified in the linker regions located between the heptameric
tet operator sequences. Gel shift assays revealed binding of IFN-stimulated gene
factors to these sequences, indicating that they mediate the IFNalpha-mediated
promoter stimulation. These data demonstrate an unexpected feature of the tet
responsive expression system which needs to be taken into account when using this
system for analysis of cytokine functions in vitro and in vivo. The data also
imply that the tet promoter-based expression system can be rendered non
responsive to IFNalpha by mutagenesis of the ISREs and this may be essential when
considering gene therapy in vivo.
PMID- 10666453
TI - Tissue-specific chromatin structure of the phenobarbital-responsive unit and
proximal promoter of CYP2B1/2 and modulation by phenobarbital.
AB - Phenobarbital induction of transcription of CYP2B genes is mediated by an
enhancer, termed a phenobarbital responsive unit (PBRU), approximately 2000 bp 5'
of the transcription start site. To further delineate the mechanism of
phenobarbital induction, protein binding in native chromatin and the nucleosomal
structure of the PBRU and proximal promoter were examined in liver and kidney, in
which the CYP2B1/2 genes are expressed and not expressed, respectively. Protein
binding to the PBRU in kidney chromatin was not detected even though in vitro
DNase I footprints were not detectably different with nuclear extracts from liver
and kidney. Likewise, protein binding to regulatory motifs was not detected in
the proximal promoter region in kidney chromatin. In liver chromatin, however,
DNase I hypersensitivity and partial protection of the regulatory motifs from
DNase I digestion or reaction with dimethyl sulfate was observed and
phenobarbital treatment increased the hypersensitivity but only modestly affected
protection. Low resolution Southern analysis of micrococcal nuclease-digested
chromatin from untreated rats revealed micrococcal nuclease hypersensitive
regions in the proximal promoter and PBRU regions in liver, but not in kidney.
Phenobarbital treatment increased hyper-sensitivity in liver in both regions.
Micrococcal nuclease hypersensitivity in the PBRU was largely restricted to a
linker region between phased nucleosomes while in the proximal promoter
hypersensitivity extended over approximately 200 bp suggesting disruption of a
nucleosome in this region. These data indicate that in liver phenobarbital
treatment substantially alters protein binding to regulatory motifs in the PBRU,
while not greatly affecting such binding in the proximal promoter, and
substantially alters chromatin structure in both regions, presumably as a result
of chromatin modifying factors recruited to the PBRU. In the kidney, chromatin is
probably in a closed conformation that prevents binding of regulatory factors.
PMID- 10666454
TI - Polymorphisms in the large subunit of human RNA polymerase II as target for
allele-specific inhibition.
AB - The lack of specificity of cancer treatment causes damage to normal cells as
well, which limits the therapeutic range. To circumvent this problem one would
need to use an absolute difference between normal cells and cancer cells as
therapeutic target. Such a difference exists in the genome of all individuals
suffering from a tumor that is characterized by loss of genetic material [loss of
heterozygosity (LOH)]. Due to LOH, the tumor is hemizygous for a number of genes,
whereas the normal cells of the individual are heterozygous for these genes.
Theoretically, polymorphic sites in these genes can be utilized to selectively
target the cancer cells with an antisense oligonucleotide, provided that it can
discriminate the alleles and inhibit gene expression. Furthermore, the targeted
gene should be essential for cell survival, and 50% gene expression sufficient
for the cell to survive. This will allow selective killing of cancer cells
without concomitant toxicity to normal cells. As an initial step in the
experimental test of this putative selective cancer cell therapy, we have
developed a set of antisense phosphorothioate oligonucleotides which can
discriminate the two alleles of a polymorphic site in the gene encoding the large
subunit of RNA polymerase II. Our data show that the exact position of the
antisense oligonucleotide on the mRNA is of essential importance for the oligo
nucleotide to be an effective inhibitor of gene expression. Shifting the
oligonucleotide position only a few bases along the mRNA sequence will completely
abolish the inhibitory activity of the antisense oligonucleotide. Reducing the
length of the oligonucleotides to 16 bases increases the allele specificity. This
study shows that it is possible to design oligonucleotides that selectively
target the matched allele, whereas the expression level of the mismatched allele,
that differs by one nucleotide, is only slightly affected.
PMID- 10666455
TI - Characterization of the E.coli poly(A) polymerase: nucleotide specificity, RNA
binding affinities and RNA structure dependence.
AB - Polyadenylation of RNA molecules in bacteria and chloroplasts has been implicated
as part of the RNA degradation pathway. The polyadenylation reaction is performed
in Escherichia coli mainly by the enzyme poly(A) polymerase I (PAP I). In order
to understand the molecular mechanism of RNA poly-adenylation in bacteria, we
characterized the biochemical properties of this reaction in vitro using the
purified enzyme. Unlike the PAP from yeast nucleus, which is specific for ATP,
E.coli PAP I can use all four nucleotide triphosphates as substrates for addition
of long ribohomopolymers to RNA. PAP I displays a high binding activity to
poly(U), poly(C) and poly(A) ribohomopolymers, but not to poly(G). The 3'-ends of
most of the mRNA molecules in bacteria are characterized by a stem-loop
structure. We show here that in vitro PAP I activity is inhibited by a stem-loop
structure. A tail of two to six nucleo-tides located 3' to the stem-loop
structure is sufficient to overcome this inhibition. These results suggest that
the stem-loop structure located in most of the mRNA 3'-ends may function as an
inhibitor of poly-adenylation and degradation of the corresponding RNA molecule.
However, RNA 3'-ends produced by endonucleolytic cleavage by RNase E in single
strand regions of mRNA molecules may serve as efficient substrates for
polyadenylation that direct these molecules for rapid exonucleolytic degradation.
PMID- 10666456
TI - Regulation of double-strand break-induced mammalian homologous recombination by
UBL1, a RAD51-interacting protein.
AB - Mammalian RAD51 protein plays essential roles in DNA homologous recombination,
DNA repair and cell proliferation. RAD51 activities are regulated by its
associated proteins. It was previously reported that a ubiquitin-like protein,
UBL1, associates with RAD51 in the yeast two-hybrid system. One function of UBL1
is to covalently conjugate with target proteins and thus modify their function.
In the present study we found that non-conjugated UBL1 forms a complex with RAD51
and RAD52 proteins in human cells. Overexpression of UBL1 down-regulates DNA
double-strand break-induced homologous recombination in CHO cells and reduces
cellular resistance to ionizing radiation in HT1080 cells. With or without
overexpressed UBL1, most homologous recombination products arise by gene
conversion. However, overexpression of UBL1 reduces the fraction of bidirectional
gene conversion tracts. Overexpression of a mutant UBL1 that is incapable of
being conjugated retains the ability to inhibit homologous recombination. These
results suggest a regulatory role for UBL1 in homologous recombination.
PMID- 10666457
TI - Understanding oligonucleotide-mediated inhibition of gene expression in Xenopus
laevis oocytes.
AB - Triplex-forming oligonucleotides (TFOs) modified with N,N-diethylethylenediamine
can inhibit the expression of a reporter plasmid in Xenopus oocytes if the
triplex is preformed prior to injection while unmodified oligonucleotides cannot.
Here we show that merely forming a triplex in a reporter plasmid does not disrupt
transcription, but when TFOs are targeted to sites within the transcribed region
of a reporter gene then gene activity is inhibited. TFO-based inhibition did not
lead to large scale degradation or mutation of the reporter plasmid, but
dramatically lowered mRNA levels. Finally, we investigated the accessibility of a
triplex target site on a reporter plasmid after injection into nuclei. We found
that the site used for our previous studies was inaccessible to restriction
endonuclease after injection into nuclei. This observation may explain why
inhibition was dependent on forming the triplex before injection into oocytes.
Based on the assumption that oligonucleotide association, like restriction enzyme
access, was excluded by nucleosome formation, additional target sites were
inserted so that all sites could not simultaneously be associated with the
octamer core of a nucleosome. With multiple target sites prior association of the
plasmid with nuclear proteins does not prevent oligonucleotide-mediated
inhibition of gene activity.
PMID- 10666458
TI - Recognition of 5-aminouracil (U(#)) in the central strand of a DNA triplex:
orientation selective binding of different third strand bases.
AB - A necessary feature of the natural base triads for triplex formation is the
requirement of a purine (A or G) in the central position, since only these
provide sets of two hydrogen bond donors/acceptors in the major groove of the
double helix. Pyrimidine bases devoid of this feature have incompatible
complementarity and lead to triplexes with lower stability. This paper
demonstrates that 5-aminouracil (U#) (I), a pyrimidine nucleobase analogue of T
in which 5-methyl is replaced by 5-amino group, with hydrogen bonding sites on
both sides, is compatible in the central position of triplex triad X*U# x A,
where X = A/G/C/T/2-aminopurine (AP), and * and x represent Hoogsteen and Watson
Crick hydrogen bonding patterns respectively. A novel recognition selectivity
based on the orientation (parallel/antiparallel) of the third strand purines A, G
or AP with A in the parallel motif (A(p)*U# x A), and G/AP in the antiparallel
motif (G(ap)/AP(ap)*U# x A) is observed. Similarly for pyrimidines in the third
strand, C is accepted only in a parallel mode (C(p)*U(#) x A). Significantly, T
is recognised in both parallel and antiparallel modes (T(p)/T(ap)*U(#) x A), with
the antiparallel mode being stable compared to the parallel one. The 'U(#)'
triplexes are also more stable than the corresponding control 'T' triplexes. The
results expand the lexicon of triplex triads with a recognition motif consisting
of pyrimidine in the central strand.
PMID- 10666459
TI - Stereochemical control of DNA biosynthesis.
AB - Stereochemical control of DNA biosynthesis was studied using several DNA
synthesizing complexes containing, in each case, a single substitution of a 2'
deoxy-D-nucleotide residue by an enantiomeric L-nucleotide residue in a DNA chain
(either in the primer or in the template) as well as 2'-deoxy-L-ribonucleoside 5'
triphosphates (L-dNTPs) as substrates. Three template-dependent DNA polymerases
were tested, Escherichia coli DNA polymerase I Klenow fragment, Thermus aquaticus
DNA polymerase and avian myeloblastosis virus reverse transcriptase, as well as
template-independent calf-thymus terminal deoxynucleotidyl transferase. Very
stringent control of stereoselectivity was demonstrated for template-dependent
DNA polymerases, whereas terminal deoxynucleotidyl transferase was less
selective. DNA polymerase I and reverse transcriptase catalyzed formation of
dinucleoside 5',5'-tetraphosphates when L-dTTP was used as substrate. Comparison
between models of template-primer complexes, modified or not by a single L
nucleotide residue, revealed striking differences in their geometry.
PMID- 10666460
TI - Specific bonding of puromycin to full-length protein at the C-terminus.
AB - Puromycin, an analog of the 3' end of aminoacyl-tRNA, causes premature
termination of translation by being linked non-specifically to growing
polypeptide chains. Here we report the interesting phenomenon that puromycin
acting as a non-inhibitor at very low concentration (e.g. 0.04 microM) can bond
only to full-length protein at the C-terminus. This was proved by using a
carboxypeptidase digestion assay of the products obtained by Escherichia coli
cell-free translation of human tau 4 repeat (tau4R) mRNA in the presence of low
concentrations of puromycin or its derivatives. The tau4R mRNA was modified to
code for three C-terminal methionines, which were radioactively labeled, followed
by a stop codon. The translation products could not be digested by carboxy
peptidase if puromycin or a derivative was present at the C-terminus of full
length tau4R. Puromycin and its derivatives at 0. 04-1.0 microM bonded to 7-21%
of full-length tau4R, depending on the ability to act as acceptor substrates.
Furthermore, the bonding efficiency of a puromycin derivative to tau4R was
decreased by addition of release factors. These results suggest that puromycin
and its derivatives at concentrations lower than those able to compete
effectively with aminoacyl-tRNA can bond specifically to full-length protein at a
stop codon. This specific bonding of puromycin to full-length protein should be
useful for in vitro selection of proteins and for in vitro and in vivo C-terminal
end protein labeling.
PMID- 10666462
TI - DNA sequence analysis by hybridization with oligonucleotide microchips: MALDI
mass spectrometry identification of 5mers contiguously stacked to microchip
oligonucleotides.
AB - Matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) has been
applied to increase the informational output from DNA sequence analysis. It has
been used to analyze DNA by hybridization with microarrays of gel-immobilized
oligonucleotides extended with stacked 5mers. In model experiments, a 28 nt long
DNA fragment was hybridized with 10 immobilized, overlapping 8mers. Then, in a
second round of hybridization DNA-8mer duplexes were hybridized with a mixture of
10 5mers. The stability of the 5mer complex with DNA was increased to raise the
melting temperature of the duplex by 10-15 degrees C as a result of stacking
interaction with 8mers. Contiguous 13 bp duplexes containing an internal break
were formed. MALDI MS identified one or, in some cases, two 5mers contiguously
stacked to each DNA-8mer duplex formed on the microchip. Incorporating a mass
label into 5mers optimized MALDI MS monitoring. This procedure enabled us to
reconstitute the sequence of a model DNA fragment and identify polymorphic
nucleotides. The application of MALDI MS identification of contiguously stacked
5mers to increase the length of DNA for sequence analysis is discussed.
PMID- 10666461
TI - The catalytic subunit DNA-dependent protein kinase (DNA-PKcs) facilitates
recovery from radiation-induced inhibition of DNA replication.
AB - Exposure of cells to ionizing radiation inhibits DNA replication in a dose
dependent manner. The dose response is biphasic and the initial steep component
reflects inhibition of replicon initiation thought to be mediated by activation
of the S-phase checkpoint. In mammalian cells, inhibition of replicon initiation
requires the ataxia telagiectasia mutated ( ATM ) gene, a member of the
phosphatidyl inositol kinase-like (PIKL) family of protein kinases. We studied
the effect on replicon initiation of another member of the PI-3 family of protein
kinases, the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) by
measuring either total DNA synthesis, or size distribution of nascent DNA using
alkaline sucrose gradient centrifugation. Exposure of human cells proficient in
DNA-PKcs (HeLa or M059-K) to 10 Gy inhibited replicon initiation in a time
dependent manner. Inhibition was at a maximum 1 h after irradiation and recovered
at later times. Similar treatment of human cells deficient in DNA-PKcs (M059-J)
inhibited replicon initiation to a similar level and with similar kinetics;
however, no evidence for recovery, or only limited recovery, was observed for up
to 8 h after irradiation. In addition a defect was observed in the maturation of
nascent DNA. Similarly, a Chinese hamster cell line deficient in DNA-PKcs (irs
20) showed little evidence for recovery of DNA replication inhibition up to 6 h
after irradiation, whereas the parental CHO cells showed significant recovery and
an irs-20 derivative expressing the human DNA-PKcs complete recovery within 4 h.
Normal kinetics of recovery were observed in xrs-5 cells, deficient in Ku80; in
180BR cells, deficient in DNA ligase IV; as well as XR-1 cells, deficient in
XRCC4, an accessory factor of DNA ligase IV. Since all these cell lines share the
DNA double strand break rejoining defect of M059-J and irs20 cells, the lack of
recovery of DNA replication in the latter cells may not be attributed entirely to
the prolonged presence of unrepaired DNA dsb. We propose that DNA-PKcs, in
addition to its functions in the rejoining of DNA dsb and in DNA replication,
also operates in a pathway that in normal cells facilitates recovery of DNA
replication after irradiation.
PMID- 10666463
TI - Identification of a novel 70 kDa protein that binds to the core promoter element
and is essential for ribosomal DNA transcription.
AB - Mammalian ribosomal RNA genes (rDNA) are transcribed by RNA polymerase I and at
least two auxiliary factors, UBF and SL1/TFID/TIF-IB. It has also been reported
that an additional factor(s) is required to reconstitute efficient initiation of
rDNA transcription in vitro, depending upon the procedures of chromatographic
separation. In an attempt to elucidate the molecular identity of such yet
uncertain activities, we have developed agarose gel shift and UV cross-linking
assays to detect proteins directly bound to the core promoter region of murine
rDNA. With these techniques, we identified a 70 kDa protein (p70) in the flow
through fraction of a phosphocellulose column (TFIA-fraction). Interestingly, the
binding of p70 to the rDNA core promoter was observed only in the presence of the
SL1-containing fraction. The probable human orthologue of p70 was also detected
in HeLa cells. Consistent with the observation that p70 bound to the core
promoter only in the presence of the TFIA- and SL1-fractions, alteration of DNase
I footprint pattern over the core promoter element was demonstrated by
cooperative action of the TFIA- and SL1-fractions. A reconstituted in vitro
transcription assay with further purified p70 indicated that p70 was required for
accurate initiation of rDNA transcription. These results indicate that the p70
identified recently by the current DNA-binding experiments represents a novel
transcription factor in rDNA transcription.
PMID- 10666464
TI - Evaluation and characterization of catabolite-responsive elements (cre) of
Bacillus subtilis.
AB - A global mechanism of catabolite repression of the genus Bacillus comprises
negative regulation exerted through the binding of the CcpA protein to the
catabolite-responsive elements (cres) of the target genes. We searched for cre
sequences in the Bacillus subtilis genome using a query sequence, WTGNAANCGNWNNCW
(N and W stand for any base and A or T, respectively), picking out 126 putative
and known cre sequences. To examine their cre function, we integrated spac
promoter (P spac )-cre-lacZ fusions into the amyE locus. Examination of
catabolite repression of beta-galactosidase synthesis in the integrants led us to
the following conclusions: (i) lower mismatching of cre sequences to the query
sequence is required for their function; (ii) although cre sequences are
partially palindromic, low mismatching in the same direction as that of
transcription of the target genes is more critical for their function than that
in the inverse direction; and (iii) yet, a more palindromic nature of cre
sequences is desirable for a better function. Furthermore, the alignment of 22
cre s that function in vivo implicated a consensus sequence, WWTGNAARCGNWWWCAWW
(R stands for G or A). Interestingly, in the case where cre sequences are located
in the protein-coding regions of the target genes, their conserved bases are
preferentially the third bases of codons where base degeneracy is allowed.
PMID- 10666465
TI - Poly(A)-binding protein I of Leishmania: functional analysis and localisation in
trypanosomatid parasites.
AB - Regulation of gene expression in trypanosomatid parasites is predominantly post
transcriptional. Primary transcripts are trans-spliced and polyadenylated to
generate mature mRNAs and transcript stability is a major factor controlling
stage-specific gene expression. Degenerate PCR has been used to clone the gene
encoding the Leishmania homologue of poly(A)-binding protein (Lm PAB1), as an
approach to the identification of trans-acting factors involved in this atypical
mode of eukaryotic gene expression. lmpab1 is a single copy gene encoding a 63
kDa protein which shares major structural features but only 35-40% amino acid
identity with other PAB1 sequences, including those of other trypanosomatids. Lm
PAB1 is expressed at constant levels during parasite differentiation and is
phosphorylated in vivo. It is localised predominantly in the cytoplasm but
inhibition of transcription with actinomycin D also reveals diffuse localisation
in the nucleus. Lm PAB1 binds poly(A) with high specificity and affinity but
fails to complement a null mutation in Saccharomyces cerevisiae. These properties
are indicative of functional divergence in vivo.
PMID- 10666466
TI - Evidence for evolutionarily conserved secondary structure in the H19 tumor
suppressor RNA.
AB - The molecular basis for function of the mammalian H19 as a tumor suppressor is
poorly understood. Large, conserved open reading frames (ORFs) are absent from
both the human and mouse cDNAs, suggesting that it may act as an RNA.
Contradicting earlier reports, however, recent studies have shown that the H19
transcript exists in polysomal form and is likely translated. To distinguish
between possible functional roles for the gene product, we have characterized the
sequence requirements for H19-mediated in vitro suppression of tumor cell
clonogenicity and analyzed the sequence of the gene cloned from a range of
mammals. A cDNA version of the human gene, lacking the unusually short introns
characteristic of imprinted genes, is as effective as a genomic copy in blocking
anchorage-independent growth by G401 cells. The first 710 nucleotides of the gene
can be deleted with no effect on in vitro activity. Further truncations from
either the 5'- or 3'-end, however, cause a loss of suppression of clonogenicity.
Using conserved sequences within the H19 gene as PCR primers, genomic DNA
fragments were amplified from a range of mammalian species that span the
functional domain defined by deletion analysis. Sequences from cat, lynx,
elephant, gopher and orangutan complement the previous database of sequences from
human, mouse, rat and rabbit. Hypothetical translation of the resulting sequences
shows an absence of conserved ORFs of any size. Free energy and covariational
analysis of the RNA sequences was used to identify potential helical pairings
within the H19 transcript. A set of 16 helices are supported by covariation (i.e.
conservation of base pairing potential in the absence of primary sequence
conservation). The predicted RNA pairings consist largely of local hairpins but
also include several long range interactions that bridge the 5'- and 3'-ends of
the functional domain. Given the evolutionary conservation of structure at the
RNA level and the absence of conservation at the protein level, we presume that
the functional product of the H19 gene is a structured RNA.
PMID- 10666467
TI - A highly ordered structure in V(D)J recombination cleavage complexes is
facilitated by HMG1.
AB - Central to understanding the process of V(D)J recombination is appreciation of
the protein-DNA complex which assembles on the recombination signal sequences
(RSS). In addition to RAG1 and RAG2, the protein HMG1 is known to stimulate the
efficiency of the cleavage reaction. Using electrophoretic mobility shift
analysis we show that HMG1 stimulates the in vitro assembly of a stable complex
with the RAG proteins on each RSS. We use UV crosslinking studies of this complex
with azido-phenacyl derivatized probes to map the contact sites between the RAG
proteins, HMG1 derivatives and the RSS. We find that the RAG proteins make
contacts at the nonamer, heptamer and adjacent coding region. The HMG1 protein by
itself appears to localize at the 3' side of the nonamer, but a cooperative
complex with the RAG proteins is positioned at the 3' side of the heptamer and
adjacent spacer in the 12RSS. In the complex with RAG proteins, HMG1 is
positioned primarily in the spacer of the 23RSS. We suggest that bends introduced
into these DNA substrates at specific locations by the RAG proteins and HMG1 may
help distinguish the 12RSS from the 23RSS and may therefore play an important
role in the coordinated reaction.
PMID- 10666468
TI - Protein sequences conserved in prokaryotic aminoacyl-tRNA synthetases are
important for the activity of the processivity factor of human mitochondrial DNA
polymerase.
AB - Previous studies have shown that the small subunit of Xenopus DNA polymerase
gamma (pol gammaB) acts as a processivity factor to stimulate the 140 kDa
catalytic subunit of human DNA polymerase gamma. A putative human pol gammaB
initially identified by analysis of DNA sequence had not been shown to be
functional, and appeared to be an incomplete clone. In this paper, we report the
cloning of full-length human and mouse pol gammaB. Both human and mouse pol
gammaB proteins were expressed in their mature forms, without their apparent
mitochondrial localization signals, and shown to stimulate processivity of the
recombinant catalytic subunit of human pol gammaA. Deletion analysis of human pol
gammaB indicated that blocks of sequence conserved with prokaryotic class II
aminoacyl-tRNA synthetases are necessary for activity and inter-action with human
pol gammaA. Purification of DNA pol gamma from HeLa cells indicated that both
proteins are associated in vivo.
PMID- 10666469
TI - Purification and characterization of the DNA cleavage and recognition site of I
ScaI mitochondrial group I intron encoded endonuclease produced in Escherichia
coli.
AB - The second intron in the mitochondrial cytb gene of Saccharomyces capensis,
belonging to group I, encodes a 280 amino acid protein containing two LAGLIDADG
motifs. Genetic and molecular studies have previously shown that this protein has
a dual function in the wild-type strain. It acts as a specific homing
endonuclease I- Sca I promoting intron mobility and as a maturase promoting
intron splicing. Here we describe the synthesis of a universal code equivalent to
the mitochondrial sequence coding for this protein and the in vitro
characterization of I- Sca I endonuclease activity, using a truncated mutant form
of the protein p28bi2 produced in Escherichia coli. We have also determined the
cleavage pattern as well as the recognition site of p28bi2. It was found that
p28bi2 generates a double-strand cleavage downstream from the intron insertion
site with 4 nt long 3'-overhangs. Mutational analysis of the DNA target site
shows that p28bi2 recognizes a 16-19 bp sequence from positions -11 to +8 with
respect to the intron insertion site.
PMID- 10666470
TI - Structures of m-iodo Hoechst-DNA complexes in crystals with reduced solvent
content: implications for minor groove binder drug design.
AB - The DNA photosensitisers m-iodo Hoechst and m-iodo, p-methoxy Hoechst have been
co-crystallised with the oligonucleotide d(CGCGAATTCGCG)(2)and their crystal
structures determined. The crystals were then subjected to slow dehydration,
which reduced their solvent contents from 40 (normal) to 30 (partially
dehydrated) and then 20% (fully dehydrated) and caused a reduction in cell volume
from 68,000 to 60,000 then 51,000 A(3). The dehydration resulted in a dramatic
enhancement of diffraction resolution from approximately 2.6 to beyond 1.5 A.
Crystal structures have also been determined for the partially and fully
dehydrated states. The fully dehydrated crystals consist of an infinite polymeric
network, in which neighbouring dodecamer duplexes are crosslinked through
phosphate oxygens via direct bonding to bridging magnesium cations. This unique
three-dimensional structure for DNA is described in detail in the following
companion paper. The present paper details evidence from the sequence of crystal
structures that the DNA is able to breathe locally, allowing the ligand to leave
the minor groove, re-orient in the surrounding solvent medium and then re-enter
the groove in a different orientation and location. The rearrangement of the
minor groove binding ligands during the dehydration process mimics the binding
behaviour of these ligands in solution and in vivo. We also present details of
the DNA-ligand interactions that are consistent with a hydrogen atom ion
mechanism for photocleavage of DNA.
PMID- 10666471
TI - Intermolecular interactions and water structure in a condensed phase B-DNA
crystal.
AB - By controlled dehydration, the unit cells of dodecamer DNA-drug crystals have
been shrunk from 68,000 (normal state) to 60,000 (partially dehydrated
intermediate state) to 51,000 A(3) (fully dehydrated state), beyond which no
further solvent loss occurs. The total solvent content in the normal crystals is
approximately 40% by volume, reducing to approximately 20% in the fully
dehydrated phase. The 25% reduction in cell volume induced a dramatic enhancement
in the resolution of the X-ray diffraction data (from 2. 6 to beyond 1.5 A). We
have determined the structures of the normal, partially dehydrated and fully
dehydrated crystals. Details of the ligand binding have been presented in the
preceding article. The present paper describes the unique features of the
structure of the fully dehydrated phase. This structure was refined with 9,015
unique observed reflections to R = 14.9%, making it one of the most reliable
models of B -form DNA available. The crystals exist as infinite polymeric
networks, in which neighbouring dodecamer duplexes are crosslinked through
phosphate oxygens via direct bonding to magnesium cations. The DNA is packed so
tightly that there is essentially only a single layer of solvent between adjacent
molecules. The details of the crystal packing, magnesium bridging, DNA hydration
and DNA conformation are described and compared with other experimental evidence
related to DNA condensation.
PMID- 10666472
TI - RNA-binding properties of the mitochondrial Y-box protein RBP16.
AB - We have previously identified a mitochondrial Y-box protein in Trypanosoma brucei
that we designated RBP16. The predicted RBP16 amino acid sequence revealed the
presence of a cold-shock domain at its N-terminus and a glycine- and arginine
rich C-terminus reminiscent of an RGG RNA-binding motif. Since RBP16 is capable
of interacting with different guide RNAs (gRNAs) in vitro and in vivo primarily
via the oligo(U) tail, as well as with ribosomal RNAs, possible functions of
RBP16 may be in kinetoplastid RNA editing and/or translation. Herein, we report
experiments that further define the RNA-binding properties of RBP16. RBP16 forms
a single stable complex with the gRNA gA6[14] at low protein concentration, while
at higher protein concentration two stable complexes that possibly represent two
different conformations are observed. Both complexes are stable at relatively
high salt and moderate heparin concentrations indicating that the binding of
RBP16 to gA6[14] does not rely primarily on ionic interactions. Phenylglyoxal
treatment of the protein indicates that arginine residues are important in RNA
binding. The minimal length of RNA sequence necessary for the binding of RBP16
was assessed by gel retardation and UV cross-linking competition assays using
oligo(U) ribonucleotides of varying lengths (4-40 nt). Although RBP16 can bind to
oligonucleotides as small as U(4), its affinity increases with the length of the
oligo(U) ribonucleotide, with a dramatic increase in binding efficiency observed
when the length is increased to 10 nt. Gel retardation assays employing T.brucei
mRNAs demonstrated that, although it acts as a major binding determinant, a 3' U
tail is not an absolute requirement for efficient RBP16-RNA binding. Experiments
with oligonucleotides containing U stretches embedded at different positions in
oligo(dC) indicated that high-affinity binding requires both a uridine stretch,
as well as 5' and 3' non-specific sequences. These results suggest a model for
the molecular interactions involved in RBP16-RNA binding.
PMID- 10666473
TI - Terminal deoxynucleotidyl transferase catalyzes the reaction of DNA
phosphorylation.
AB - The reaction of phosphorylation and phosphonylation of an oligodeoxynucleotide 3'
terminal hydroxyl (oligodeoxynucleotidyl kinase activity) catalyzed by calf
thymus terminal deoxynucleotidyl transferase (TDT) was found. Triphosphates
modified at Palpha-, Palpha,gamma- or Palpha,beta,gamma-residues served as low
molecular weight substrates. The reaction was TDT specific; human DNA
polymerasesalphaandbeta, as well as AMV reverse transcriptase did not catalyze
it. The donor activity of modified triphosphates or triphosphonates depended on
their structure and was increased with an increase in their hydrophobicity. The
substrate activity of some modified triphosphates was up to one order of
magnitude higher than that of ddTTP.
PMID- 10666474
TI - A novel procedure for efficient genotyping of single nucleotide polymorphisms.
AB - Due to the surge in interest in using single nucleotide polymorphisms (SNPs) for
genotyping a facile and affordable method for this is an absolute necessity. Here
we introduce a procedure that combines an easily automatable single tube sample
preparation with an efficient high throughput mass spectrometric analysis
technique. Known point mutations or single nucleotide polymorphisms are easily
analysed by this procedure. It starts with PCR amplification of a short stretch
of genomic DNA, for example an exon of a gene containing a SNP. By shrimp
alkaline phosphatase digest residual dNTPs are destroyed. Allele-specific
products are generated using a special primer, a conditioned set of alpha-S-dNTPs
and alpha-S-ddNTPs and a fresh DNA polymerase in a primer extension reaction.
Unmodified DNA is removed by 5'-phospho-diesterase digestion and the modified
products are alkylated to increase the detection sensitivity in the mass
spectrometric analysis. All steps of the preparation are simple additions of
solutions and incubations. The procedure operates at the lowest practical sample
volumes and in contrast to other genotyping protocols with mass spectrometric
detection requires no purification. This reduces the cost and makes it easy to
implement. Here it is demonstrated in a version using positive ion detection on
described mutations in exon 17 of the amyloid precursor protein gene and in a
version using negative ion detection on three SNPs of the granulocyte-macrophage
colony stimulating factor gene. Preparation and analysis of SNPs is shown
separately and simultaneously, thus demonstrating the multiplexibility of this
genotyping procedure. The preparation protocol for genotyping is adapted to the
conditions used for the SNP discovery method by denaturing HPLC, thus
demonstrating a facile link between protocols for SNP discovery and SNP
genotyping. Results corresponded unanimously with the control sequencing. The
procedure is useful for high throughput genotyping as it is required for gene
identification and pharmacogenomics where large numbers of DNA samples have to be
analysed. We have named this procedure the 'GOOD Assay' for SNP analysis.
PMID- 10666475
TI - Functional coexpression of serine protein kinase SRPK1 and its substrate ASF/SF2
in Escherichia coli.
AB - Mammalian proteins expressed in Escherichia coli are used in a variety of
applications. A major drawback in producing eukaryotic proteins in E.coli is that
the bacteria lack most eukaryotic post-translational modification systems,
including serine/threonine protein kinase(s). Here we show that a eukaryotic
protein can be phosphorylated in E.coli by simultaneous expression of a mammalian
protein kinase and its substrate. We show that in bacteria expressing SRPK1,
ASF/SF2 becomes phosphorylated to a degree resembling native ASF/SF2 present in
interphase HeLa cell nuclei. The E.coli phosphorylated ASF/SF2 is functional in
splicing and, contrary to the unphosphorylated protein, soluble under native
conditions.
PMID- 10666476
TI - How cells use proteolysis to control their growth.
PMID- 10666478
TI - Macroscopic spectral imaging and gene expression analysis of the early stages of
melanoma.
AB - BACKGROUND: The stages of melanocytic progression are defined as atypical
(dysplastic) nevus, melanoma in situ, melanoma in the radial growth phase (RGP),
melanoma in the vertical growth phase (VGP), and melanoma in the metastatic
growth phase (MGP). Melanoma in situ and RGP melanoma often develop in contiguous
association with atypical nevi. This frequently poses a problem with respect to
their early detection. Furthermore, unlike cells obtained from VGP and MGP
melanomas, cells derived from melanoma in situ and RGP melanoma do not
proliferate in vitro. Thus, compared to the late stages of the disease, less
information is available regarding genes expressed in the early stages. MATERIALS
AND METHODS: To determine whether spectral imaging, a recently developed optical
imaging technique, can detect melanoma in situ and RGP melanoma arising in
melanoma precursor lesions, atypical nevi in patients with a clinical history of
melanoma were subjected to noninvasive macroscopic spectral imaging. To determine
at what stage in the progression pathway of melanoma genes having important
biological functions in VGP and MGP melanomas are activated and expressed,
lesions of melanoma in situ were analyzed by immunohistochemistry and in situ
hybridization for expression of some of these known molecular and immunologic
markers. RESULTS: The present study demonstrates the capability of noninvasive
spectral imaging to detect melanoma in situ and RGP melanoma that arise in
contiguous association with atypical nevi. Furthermore, the study provides
evidence that genes and antigens expressed in VGP and MGP melanoma are also
expressed in melanoma in situ. CONCLUSIONS: Because of the dark and variegated
pigmentation of atypical nevi, melanoma in situ and RGP melanoma that arise in
these melanoma precursor lesions are often difficult to recognize and thus
frequently go unnoticed. The application of new optical screening techniques for
early detection of melanoma and the identification of genes expressed in the
early stages of melanoma development are two important avenues in the pursuit of
melanoma prevention. The investigations presented here document that macroscopic
spectral imaging has the potential to detect melanoma in its early stage of
development and that genes essential for the proliferation and cell adhesion of
VGP and MGP melanoma are already expressed in melanoma in situ.
PMID- 10666479
TI - CXC and CC chemokine receptors on coronary and brain endothelia.
AB - BACKGROUND: Chemokine receptors on leukocytes play a key role in inflammation and
HIV-1 infection. Chemokine receptors on endothelia may serve an important role in
HIV-1 tissue invasion and angiogenesis. MATERIALS AND METHODS: The expression of
chemokine receptors in human brain microvascular endothelial cells (BMVEC) and
coronary artery endothelial cells (CAEC) in vitro and cryostat sections of the
heart tissue was determined by light and confocal microscopy and flow cytometry
with monoclonal antibodies. Chemotaxis of endothelia by CC chemokines was
evaluated in a transmigration assay. RESULTS: In BMVEC, the chemokine receptors
CCR3 and CXCR4 showed the strongest expression. CXCR4 was localized by confocal
microscopy to both the cytoplasm and the plasma membrane of BMVEC. In CAEC, CXCR4
demonstrated a strong expression with predominantly periplasmic localization.
CCR5 expression was detected both in BMVEC and CAEC but at a lower level. Human
umbilical cord endothelial cells (HUVEC) expressed strongly CXCR4 but only weakly
CCR3 and CCR5. Two additional CC chemokines, CCR2A and CCR4, were detected in
BMVEC and CAEC by immunostaining. Immunocytochemistry of the heart tissues with
monoclonal antibodies revealed a high expression of CXCR4 and CCR2A and a low
expression of CCR3 and CCR5 on coronary vessel endothelia. Coronary endothelia
showed in vitro a strong chemotactic response to the CC chemokines RANTES, MIP
1alpha, and MIP-1beta. CONCLUSIONS: The endothelia isolated from the brain
display strongly both the CCR3 and CXCR4 HIV-1 coreceptors, whereas the coronary
endothelia express strongly only the CXCR4 coreceptor. CCR5 is expressed at a
lower level in both endothelia. The differential display of CCR3 on the brain and
coronary endothelia could be significant with respect to the differential
susceptibility of the heart and the brain to HIV-1 invasion. In addition, CCR2A
is strongly expressed in the heart endothelium. All of the above chemokine
receptors could play a role in endothelial migration and repair.
PMID- 10666480
TI - Twenty novel mutations in the alpha-galactosidase A gene causing Fabry disease.
AB - BACKGROUND: Fabry disease, an X-linked inborn error of glycosphingolipid
catabolism, results from the deficient activity of the lysosomal
exoglycohydrolase alpha-galactosidase A (EC 3.2.1.22; alpha-Gal A). The nature of
the molecular lesions in the alpha-Gal A gene in 30 unrelated families was
determined to provide precise heterozygote detection, prenatal diagnosis, and
define genotype-phenotype correlations. MATERIALS AND METHODS: Genomic DNA was
isolated from affected males and/or carrier females from 30 unrelated families
with Fabry disease. The entire alpha-Gal A coding region and flanking intronic
sequences were analyzed by PCR amplification and automated sequencing. RESULTS:
Twenty new mutations were identified, each in a single family: C142R, G183D,
S235C, W236L, D244H, P259L, M267I, I289F, Q321E, C378Y, C52X, W277X, IVS4(+4),
IVS6(+2), IVS6(-1), 35del13, 256del1, 892ins1, 1176del4, and 1188del1. In the
remaining 10 unrelated Fabry families, 9 previously reported mutations were
detected: M42V, R112C, S148R, D165V, N215S (in 2 families), Q99X, C142X, R227X,
and 1072del3. Haplotype analysis using markers closely flanking the alpha-Gal A
gene indicated that the two patients with the N215S lesion were unrelated. The
IVS4(+4) mutation was a rare intronic splice site mutation that causes Fabry
disease. CONCLUSIONS: These studies further define the heterogeneity of mutations
in the alpha-Gal A gene causing Fabry disease, permit precise heterozygote
detection and prenatal diagnosis, and help delineate phenotype-genotype
correlations in this disease. 100 days and 12/14 16.2 +/- 1.7 days; p < 0.001). The analysis of graft
infiltrating cells on day 5 after transplantation showed a significant decrease
in the number of graft infiltrating cells in RDP1258-treated recipients compared
to untreated ones (14.8 vs. 32.7%; p < 0.01). In addition, grafts from peptide
treated animals showed significantly decreased expression of TNF-alpha mRNA and
increased levels of iNOS mRNA. Our results are consistent with the recent
observation that up-regulation of HO-1 results in the inhibition of several
immune effector functions. Modulation of HO-1 activity may enable the development
of novel immunomodulatory strategies in humans.
PMID- 10666489
TI - Genetic variation and covariation of parathyroid hormone levels and bone density
in the human population.
AB - The present study was an attempt to evaluate the relative importance of
familial/genetic factors in interindividual variation of plasma concentrations of
parathyroid hormone (PTH) and bone mineral density (BMD). We also examined to
what extent common genetic and environmental factors may be involved in
covariation between the hormone concentrations and BMD levels. Ninety-five
nuclear pedigrees (consisting of 187 males and 168 females, aged 18-91 and 18-86
years old, respectively), from several small villages in the Chuvasha Autonomy,
Russia, were assessed for PTH, sex hormones, and BMD. PTH plasma levels were
measured in duplicate by immunoradiometric assay using an N-tact PTH SP kit.
Standard roentgenography was done from the second and third phalanges of the
middle finger on both hands for assessment of compact and cancellous bone BMD
separately. The present study clearly confirmed the results of the previous
genetic analyses of BMD which indicated that between 47% and 60% of the total
variance of BMD, adjusted for sex and age effects, were attributable to genetic
factors. Genetic factors also contributed significantly to interindividual
variation of PTH. Constraining these additive genetic effects to zero
dramatically increased the likelihood ratio (P < 0.001), indicating that at least
30% of the hormone plasma variation was attributable to genetic sources. The
results of bivariate decomposition analysis were not clear cut. Two types of
bivariate analyses showed that PTH-BMD genetic correlations according to sex and
between the opposite sexes were consistently negative, but only marginally
significant.
PMID- 10666490
TI - Bone mineral density and muscle strength in young men with mental retardation
(with and without Down syndrome).
AB - The objective of this study was to compare the bone mineral density (BMD) of men
with Down syndrome (DS) to otherwise mentally retarded (MR) men and to
investigate whether leg muscle strength of these patients is related to BMD. Two
groups with MR (with and without DS) participated in the study, having met the
following criteria: similar age, moderate to mild mental retardation, Tanner
stage V of sexual development, similar age of beginning to walk, and equal motor
activities. The DS group consisted of 8 men 23.9 +/- 4.2 years, and the MR group
without DS consisted of 8 men 23.5 +/- 3.6 years. The two groups were compared
with 10 sedentary students of the same age range (25.9 +/- 2.9 years) attending
our University. The BMD of the 2(nd) to 4(th) lumbar vertebrae was measured in
the PA projection and the mean density was expressed as g/cm(2). The isokinetic
muscle strength of the right quadriceps femoris and hamstrings muscles was
measured on a Cybex II isokinetic dynamometer. The value measured was peak torque
at angular velocities at 60, 120, and 300 degrees.sec(-1). The results showed
that BMD in DS individuals versus young adults (reference group of the scanner)
was lower at the 26% level (T-score - 2.66 +/- 0.29) and significantly lower (P =
0.002) than that of the MR group. Significantly different muscle strength was
observed between the DS and non-DS MR group (in quadriceps at 300 degrees.s(-1):
P < 0.01, at 120 and 60 degrees. s(-1): P < 0.05; in hamstrings at 300 degrees.s(
1): P < 0.05). Higher differences in muscle strength were found between MR and
control men, but no significant difference existed in BMD between them. Bivariate
correlation showed that quadriceps strength significantly predicted the BMD in
the DS patients. Active lifestyle and increased physical exercise to improve
muscular strength should be instituted to avoid the development of osteoporosis
in DS patients.
PMID- 10666491
TI - Association of bone mineral density with polymorphism of the human calcium
sensing receptor locus.
AB - A strong correlation between bone mass and genetic factors has been shown in
twins and family studies. Some of the genes involved would regulate bone
metabolism, bone formation, and resorption, all processes that determine bone
mass. One candidate genes, calcium-sensing receptor (CASR) in the parathyroid
gland, regulates calcium homeostasis by sensing decreases in extracellular
calcium level and effecting an increase in secretion of parathyroid hormone (PTH)
and calcium (Ca) reabsorption in the kidney. We have investigated a possible
association between the CA-repeat polymorphism at the human CASR gene locus and
the bone mineral density (BMD) of radial bone in 472 postmenopausal Japanese
women. Genotypes were classified into nine groups according to the number of CA
repeats present, from 20 to 12. BMD was expressed as the adjusted BMD, which was
the body mass index (BMI), and age-adjusted average BMD. The 247 women who had an
A3 allele (228 bp, containing 18 repeats of CA) had significantly lower adjusted
BMD (mean +/- SD: 0.303 +/- 0.059 versus 0.316 +/- 0.063 g/cm(2); P = 0.0308)
than the participants (n = 201) who did not carry an allele of that size. This
result suggests that genetic variation at the CASR gene locus is associated with
some determinants for BMD in postmenopausal women.
PMID- 10666492
TI - Vitamin D and estrogen receptor polymorphisms and bone mineral changes in
postpartum women.
AB - BsmI restriction fragment length polymorphism (RFLP) of the vitamin D receptor
(VDR) gene and PvuII RFLPs of the estrogen receptor (ER) gene and their relation
to changes in areal bone mineral density (BMD) were examined in 43 healthy
postpartum Finnish women aged 31.3 (SD 4.7) years. BMD was measured by dual
energy X-ray absorptiometry at lumbar spine, right femoral neck, and dominant
distal radius immediately after delivery, 1 month after resumption of menses, and
1 year thereafter. The RFLPs were represented as Bb (BsmI) and Pp (PvuII), the
capital letters denoting the absence of and the small letters the presence of the
restriction sites. The frequency of VDR alleles was as follows: bb (20.9%), Bb
(60.5%), and BB (18.6%), and that of ER alleles was pp (39.5%), Pp (51.2%), and
PP (9.3%). Altogether, BMD decreased significantly during postpartum amenorrhea
at all sites [the mean bone loss ranging from -1.2 (SD 3.6)% at the distal radius
to -3.7 (2.9)% at the femoral neck], and increased after resumption of menses
[the 1-year follow-up BMD values ranging from -1.0 (2.4)% at the femoral neck to
+3.3 (4.0)% at the lumbar spine as compared with baseline]. No obvious genotype
related differences were found between these changes. These results suggest that
the BsmI and PvuII polymorphisms may not have substantial influence on BMD
changes postpartum.
PMID- 10666493
TI - Association of methylenetetrahydrofolate reductase (MTHFR) polymorphism with bone
mineral density in postmenopausal Japanese women.
AB - The pathogenesis of osteoporosis is controlled by genetic and environmental
factors. Considering the high prevalence of osteoporosis in homocystinuria,
abnormal homocysteine metabolism would contribute to the pathogenesis of
osteoporosis. It is known that the polymorphism of methylenetetrahydrofolate
reductase (MTHFR), the enzyme catalyzing the reduction of 5, 10
methylenetetrahydrofolate to 5-methyltetrahydrofolate, correlates with
hyperhomocysteinemia. In this study, we examined the association of this
polymorphism with bone mineral density (BMD). BMD was measured by dual-energy X
ray absorptiometry (DXA) in 307 postmenopausal women. MTHFR A/V polymorphism was
analyzed using polymerase chain reaction restriction fragment length polymorphism
(PCR-RFLP). We compared BMD, clinical characteristics, and bone metabolic markers
among MTHFR groups (AA, AV, VV). The groups did not differ in terms of baseline
data. The values of lumbar spine BMD and total body BMD were as follows: lumbar
spine: AA, 0.91 +/- 0.18, AV, 0.88 +/- 0.16, VV, 0.84 +/- 0.14 g/cm(2); total
body: AA, 0.97 +/- 0.11, AV, 0.96 +/- 0.11, VV, 0.93 +/- 0.09 g/cm(2). In the VV
genotype, lumbar spine BMD values were significantly lower than those of the
women with the AA genotype (P = 0.016) and total body BMD was significantly lower
than those of the women with AA genotype (P = 0.03) and AV genotype (P = 0.04).
This is the first report that suggests that the VV genotype of MTHFR is one of
the genetic risk factors for low BMD.
PMID- 10666494
TI - Acute alteration in bone mineral density and biochemical markers for bone
metabolism in nephrotic patients receiving high-dose glucocorticoid and one-cycle
etidronate therapy.
AB - It is widely known that glucocorticoids induce and accelerate osteoporosis. High
dose glucocorticoids are administrated daily to patients in the acute phase of
nephrotic syndrome. It could be inferred that high-dose glucocorticoids rapidly
decrease patients' basal bone mineral density (BMD) and this accelerates the
natural progress of osteoporosis associated with aging or menopause. Nine
nephrotic patients (male/female: 5/4) without previous prednisolone
administration were chosen to measure BMD and the level of the markers for bone
turnover before and after treatment for 3 months (total prednisolone
administration: 4.5 +/- 0.0 g). Twenty-three patients under remission with
prednisolone administration (male/female: 14/9) were included in the long-term
treatment group. Patients in this group whose %YAM in the lateral lumbar spine
was less than 89% were classified into a low BMD group (n = 10, male/female:
3/7). They were administered etidronate disodium at 200 mg/day for 14 days. BMD
and % of young adult mean (YAM) in the lumbar spine (L2-L4 in lateral objection)
and other regions were measured by dual-energy X-ray absorptiometry. As markers
of bone metabolism, the urinary level of deoxypyridinoline (Dpd) was determined
to evaluate osteogenesis, and serum osteocalcin was measured to evaluate bone
resorption. BMD of the lumbar spine significantly decreased in the 3-month
treatment group (752 +/- 96 mg/cm(2), 7 +/- 4% reduction) compared with the
pretreatment group (810 +/- 85 mg/cm(2)). BMD in the long-term treatment group
decreased continuously (683 +/- 135 mg/cm(2)). No significant differences were
noted in other measurement sites. BMD in the etidronate treatment group increased
significantly (597 +/- 55 mg/cm(2)) compared with the pretreatment group (549 +/-
76 mg/cm(2)). Etidronate did not change BMD at the sites with a normal BMD. Among
the biochemical markers (BM) examined, the urinary level of Dpd (nMol/liter. Cr)
significantly increased in the 3-month treatment group (8.6 +/- 5.1
nMol/liter.Cr) compared with the pretreatment group (5.8 +/- 2.0 nMol/liter. Cr).
No significant differences were seen in the BMs measured in the long-term
treatment group. The urinary Dpd level of the etidronate treatment group
decreased (3.9 +/- 1.4 nMol/liter. Cr) compared with the pretreatment group.
These data indicate that etidronate could improve the accelerated bone
resorption. In conclusion, high-dose glucocorticoid therapy causes rapid bone
resorption and accelerates the natural progress of osteoporosis associated with
aging or menopause. Etidronate administration prevents the progress of
osteoporosis in nephrotic patients. Preventive treatment should be performed when
the estimated BMD in 3 months falls below the baseline by more than 7 +/- 4%,
reaching the therapeutic range.
PMID- 10666495
TI - Estrogen deficiency is a potential cause for osteopenia in adult male patients
with Noonan's syndrome.
AB - Osteopenia is frequently observed in patients with Turner's syndrome. By
contrast, there is no report concerning bone metabolism in patients with Noonan's
syndrome which comprises Turner's phenotypic characteristics without any sex
chromosome abnormalities. In the present investigation, we determined bone
mineral density (BMD) as well as serum and urine indices of bone turnover in two
male patients with Noonan's syndrome. Both patients showed remarkably decreased
BMD, measured at two sites on the lumbar spine (L2-L4) and the distal end of the
radius using dual energy X-ray absorptiometry (DXA). Urinary pyridinoline (PYD)
and deoxypyridinoline (DPD) concentrations were significantly elevated in both
patients, and serum osteocalcin and carboxyterminal propeptide of type I
procollagen (PICP) concentrations were elevated in one patient. Surprisingly,
both patients had a low level of serum 17beta-estradiol compared with control
males, whereas they had normal levels of serum testosterone and
dihydrotestosterone. Conjugated estrogens (Premarin 0.625 mg/day) were continued
to be administered to these patients, followed up for 12 months. Urinary PYD and
DPD concentrations gradually decreased, followed by an increase in their BMD.
This is the first report that male patients with Noonan's syndrome showed
osteopenia associated with increased bone resorption. Our data indicate that
hypoestrogenism plays a potentially significant role in the abnormal bone
metabolism in these patients.
PMID- 10666496
TI - Acellular mineral deposition in collagen-based biomaterials incubated in cell
culture media.
AB - Rapid developments in tissue engineering have renewed interest in biodegradable
three-dimensional structures such as collagen-based biomaterials. Collagen
matrices seeded in vitro with fibroblasts, osteoblasts, and chondrocytes can form
tissues resembling skin, bone, and cartilage that could be used as functional
substitutes for damaged tissues. Collagen is associated with both dystrophic
calcification of collagenous implants and bone mineralization. We report here the
calcification properties of collagen sponges incubated in cell-free media.
Mineral deposited in sponges was identified by X-ray and electron diffraction,
Fourier transform infrared spectroscopy, and the molar ratio of
calcium:phosphorus (Ca:P) as a poorly crystalline apatite similar to bone. The
degree of calcification increased with length of incubation and the Ca and P
content of the media, with 10-15% Ca (dry weight) after 21 days' incubation in
media containing 1.6-3 mM Ca and a Ca x P molar product of 2-3 mM(2), but only 2%
Ca after incubation in medium with 1.33 mM Ca and a 1.7 mM(2) Ca x P molar
product. Mineral deposition was completely inhibited in sponges that were washed
extensively and initially contained less than 0.01% P. Readdition of phosphate in
these sponges and subsequent freeze drying and sterilization restore their
mineralization capacity, suggesting that collagen per se cannot initiate
calcification and that the inorganic phosphate content associated with the
collagen preparation process is in the solid state a potential nucleator.
Addition of chondroitin 4-sulfate to the sponges partially or totally inhibited
mineral deposition, even though 80-90% of the compound was released within 24
hours. These results indicate that acellular calcification of collagen-based
biomaterials can occur under the culture conditions currently used in tissue
engineering.
PMID- 10666497
TI - A novel method to isolate odontoblasts from rat incisor.
AB - Historically, odontoblasts have been isolated from rat incisor using a surgical
curette to separate these cells from the dentin. Isolation of odontoblasts using
this approach typically resulted in cells with membrane properties that made the
application of patch-clamp electrophysiological techniques prohibitive. The
studies here describe a new procedure for isolating mature odontoblasts from
adult rat incisor to obtain enriched populations of intact, viable odontoblasts
that can be readily studied using patch-clamp methodologies. Identification of
isolated cells as odontoblasts was confirmed using in situ mRNA hybridization for
expression of dentin sialoprotein, osteocalcin, bone sialoprotein, and type I
collagen, and calcium flux was monitored in these cells by means of fura-2
microfluorometry. We suggest that either single odontoblasts or clusters of these
cells isolated by this new method would be an ideal preparation for the study of
odontoblast properties using electrophysiological techniques, in situ
hybridization and/or microfluorometry.
PMID- 10666498
TI - Prostaglandin E(2) (PGE(2)) induces the c-fos and c-jun expressions via the EP(1)
subtype of PGE receptor in mouse osteoblastic MC3T3-E1 cells.
AB - This study examined which subtype(s) of PGE receptors is involved in the
induction of c-fos and c-jun by PGE(2) in MC3T3-E1 cells. We also investigated
the possibility that the induction of these genes is involved in the growth and
differentiation of this cell line. PGE(2) dose-dependently induced c-fos and c
jun mRNA expressions in MC3T3-E1 cells. Of the PGE analogs, 17-phenyl-omega
trinor PGE(2) (EP(1) agonist) and sulprostone (EP(1)/EP(3) agonist) were far more
potent than butaprost (EP(2) agonist) and 11-deoxy PGE(1) (EP(2)/EP(4) agonist)
in inducing c-fos and c-jun mRNA expressions. Since MC3T3-E1 cells do not express
the EP(3) subtype, these results suggest that PGE(2) induces c-fos and c-jun mRNA
expressions through the EP(1) subtype of its receptor. In order to study the
functional relevance of these protooncogenes, we then studied the effect of
inhibition of their synthesis by the use of antisense oligonucleotide. Alkaline
phosphatase (ALP) suppression by 17-phenyl-omega-trinor PGE(2) was reversed by
antisense oligonucleotide for either c-fos or c-jun. These results suggest that
PGE(2), via the EP(1) subtype of the PGE receptor, negatively modulates the
transition from proliferation to the matrix maturation stage through the
induction of c-fos and c-jun. However, antisense oligonucleotide for c-fos or c
jun did not alter the prostaglandin G/H synthase-2 mRNA expression induced by
EP(1). Thus, it is possible that c-fos and c-jun inductions do not account for
all the EP(1)-mediated PGE(2) actions in MC3T3-E1 cells.
PMID- 10666499
TI - Changes in bone turnover during the menstrual cycle in cynomolgus monkeys.
AB - It is well established that estrogen deficiency at menopause results in increased
bone turnover, which is reflected in increased concentrations of markers of bone
formation and bone resorption in serum and urine. Since serum 17beta-estradiol
concentrations vary markedly throughout the menstrual cycle, one would expect to
see changes in bone turnover as well. Studies in humans have not yielded
consistent results, perhaps because of differences in diet and activity
throughout the test period. Therefore, we examined changes in bone biomarkers
throughout the menstrual cycle in cynomolgus macaques. Seven intact female
cynomolgus macaques (Macaca fascicularis) were evaluated. Vaginal swabs for
menstrual blood were performed 3 times/week to determine the stage of the
reproductive cycle. Blood and urine were collected at weekly or biweekly
intervals for a total of eight samples per monkey for analysis of serum 17beta
estradiol, progesterone, parathyroid hormone (PTH), osteocalcin, bone-specific
alkaline phosphatase (BSAP), and urinary CrossLapstrade mark. Cycle lengths were
determined, and collection days were adjusted to a standardized length of 28 days
for all monkeys. Values for bone biomakers were evaluated as % mean for each
monkey cycle. By fitting the data to a sine wave (cosinor analysis), serum
osteocalcin, BSAP, and urinary CrossLaps demonstrated significant cycles with
peaks at days 2.6, 7.3, and 27.8, respectively. Serum osteocalcin and urinary
CrossLaps were inversely correlated to serum 17beta-estradiol. Urinary CrossLaps
were significantly lower in the week just prior to and during ovulation when
estradiol was elevated. No rhythm was detected in serum PTH. A peak in bone
resorption when serum 17beta-estradiol is at its nadir is consistent with the
hypothesis that estrogen decreases bone turnover.
PMID- 10666501
TI - Clinical indications of calcium-phosphate biomaterials and related composites for
orthopedic procedures.
PMID- 10666500
TI - Histomorphometric evaluation of the recovering effect of human parathyroid
hormone (1-34) on bone structure and turnover in streptozotocin-induced diabetic
rats.
AB - The purpose of this study was to determine whether human parathyroid hormone (h
PTH) enhances trabecular bone mass and connectivities that were reduced by
streptozotocin (STZ)-induced diabetes in rats. Seven-month-old female Wistar rats
were injected with STZ or its vehicle intraperitoneally. All vehicle-injected
normal controls were sacrificed 0, 4, 6, 8, 12, 14, and 16 weeks after injection,
and one-third of the STZ-injected rats were sacrificed as the baseline controls
4, 6, and 8 weeks after the injection. Eight-week h-PTH (6. 0 microg/kg, 6 times
a week) or its vehicle treatment by subcutaneous injection for residual diabetic
rats was started 4, 6, or 8 weeks after the STZ injection. The rats' proximal
right tibiae were processed for undecalcified Villanueva bone staining sections
for bone histomorphometry. Furthermore, changes in trabecular connectivities were
determined by node-strut analysis. The decreased cancellous bone volume (BV/TV)
and turnover in diabetic rats were recovered in all PTH-treated groups. In node
strut analysis, the node-related parameters (N.Nd/TV, NdNd/TV) were significantly
increased by PTH when it was administered 4 weeks after STZ injection but were
not increased when administration was started after 6 weeks. The results
indicated that PTH enhanced bone turnover and bone mass but not trabecular
connectivity in the late stage of diabetes in rats. Early treatment of
osteoporosis is important in preventing fractures caused by decreased bone
strength resulting from decreased trabecular connectivity.
PMID- 10666502
TI - The role of calcitriol in the treatment of osteoporosis.
PMID- 10666503
TI - The dopamine D(1) receptor agonist SKF-82958 serves as a discriminative stimulus
in the rat.
AB - We examined the discriminative stimulus effects of the high-efficacy dopamine
D(1) receptor agonist (+/-)6-chloro-7, 8-dihydroxy-3-ally1-phenyl-2,3,4,5
tetrahydro-1H-3benzazepine++ + hydrobromide (SKF-82958) in rats trained to
discriminate SKF-82958 (0.03 mg/kg) from vehicle in a two-lever food-reinforced
drug discrimination task. SKF-82958 produced dose-related increases in responding
to the SKF-82958 appropriate lever with full substitution occurring at the
training dose. Pretreatment with the dopamine D(1)/D(5) receptor antagonist (-)
trans-6,7,7a,8,9, 13b-hexahydro-3-chloro-2hydroxy-N-methyl-5H-benzo-[d]naphtho
?2, 1-b?azepine (SCH-39166) (0.01 mg/kg) attenuated the discriminative stimulus
effects of SKF-82958. Pretreatment with the dopamine D(2) receptor antagonist
raclopride (0.03 mg/kg) had no effect. The high-efficacy dopamine D(1) receptor
agonist R(+)6chloro-7, 8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine
hydrobromide (SKF-81297) fully substituted for SKF-82958, whereas the low
efficacy dopamine D(1) receptor agonist (+/-)1-phenyl-2,3,4, 5-tetrahydro-(1H)-3
benzazepine-7,8-diol hydrochloride (SKF-38393) produced only partial
substitution. The dopamine D(2) receptor agonist trans-(+/-)-4,4a,5,6,7,8,8a, 9
octahydro-5-propyl-1H-propyl-1H-pyrazolo[3,4-g]quinoline dihydrochloride
(quinpirole) and the indirect dopamine agonist cocaine did not substitute fully
for the SKF-82958 discriminative stimulus cue. These results demonstrate that the
high-efficacy dopamine D(1) receptor agonist SKF-82958 can serve as an effective
discriminative stimulus in the rat, and that these effects are mediated by a
dopamine D(1)-like receptor mechanism.
PMID- 10666504
TI - Adrenomedullin decreases extracellular signal-regulated kinase activity through
an increase in protein phosphatase-2A activity in mesangial cells.
AB - Adrenomedullin is a recently identified peptide hormone that has receptors in a
number of different systems including renal mesangial cells. We reported recently
that adrenomedullin can cause a decrease in extracellular signal-regulated kinase
(ERK) activity and increase jun amino-terminal kinase (JNK) and P38 mitogen
activated protein kinase (P38 MAPK) acitivities in rat mesangial cells.
Associated with these responses we also reported that adrenomedullin can decrease
proliferation and increase apoptosis in mesangial cells. The major aim of the
present study was to examine the mechanism of decrease in ERK activity by
adrenomedullin and to identify the role of protein phosphatase 2A (PP2A) in the
decrease in ERK activity, using okadaic acid [9,10-Deepithio-9,10
didehydroacanthifolicin], a selective inhibitor of PP2A at low nanomolar
concentrations. The adrenomedullin-induced decrease in [3H]-thymidine
incorporation and increase in apoptosis were reversed by okadaic acid at the
concentration that selectively inhibits PP2A. Okadaic acid completely reversed
the ERK inhibition caused by adrenomedullin, suggesting that PP2A may be involved
in the adrenomedullin-mediated changes in proliferation, apoptosis and ERK
activity. PP2A activity in mesangial cells was increased over time following
exposure to adrenomedullin. The tyrosine phosphorylation of ERK did not change
significantly following adrenomedullin treatment although the ERK activity was
decreased significantly. This suggests that the decrease in ERK activity is not
mediated through a decrease in MEK (a dual phosphorylating kinase upstream of
ERK) or by an increase in MKP-1/2 (a dual specificity phosphatase) activities.
Thus we conclude that the mechanism of adrenomedullin-induced decrease in ERK
activity in rat mesangial cells is at least in part mediated by an increase in
PP2A activity.
PMID- 10666505
TI - sigma receptor ligands attenuate N-methyl-D-aspartate cytotoxicity in
dopaminergic neurons of mesencephalic slice cultures.
AB - We investigated the potential neuroprotective effects of several sigma receptor
ligands in organotypic midbrain slice cultures as an excitotoxicity model system.
When challenged with 100-microM N-methyl-D-aspartate (NMDA) for 24 h,
dopaminergic neurons in midbrain slice cultures degenerated, and this was
prevented by (5R, 10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,b]-cyclohepten-5,
10-imine (MK-801; 1-10 microM). Concomitant application of ifenprodil (1-10
microM) or haloperidol (1-10 microM), both of which are high-affinity sigma
receptor ligands, significantly attenuated the neurotoxicity of 100 microM NMDA.
The sigma(1) receptor-selective ligand (+)-N-allylnormetazocine ((+)-SKF 10047; 1
10 microM) was also effective in attenuating the toxicity of NMDA. The effect of
R(-)-N-(3-phenyl-1-propyl)-1-phenyl-2-aminopropane hydrochloride ((-)-PPAP), a
sigma receptor ligand with negligible affinity for the phencyclidine site of NMDA
receptors, was also examined. (-)-PPAP (3-100 microM) caused a concentration
dependent reduction of NMDA cytotoxicity, with significant protection at
concentrations of 30 and 100 microM. In contrast, (+)-SKF 10047 (10 microM) and (
)-PPAP (100 microM) showed no protective effects against cell death induced by
the Ca(2+) ionophore ionomycin (1-3 microM). These results indicate that sigma
receptor ligands attenuate the cytotoxic effects of NMDA on midbrain dopaminergic
neurons, possibly via inhibition of NMDA receptor functions.
PMID- 10666506
TI - Effect of glipizide on dopamine synthesis, release and metabolism in PC12 cells.
AB - Sulfonylureas block ATP-dependent K(+) channels (K/ATP channels) in pancreatic
beta cells and brain gamma-aminobutyric acid (GABA) containing neurons causing
depolarization-evoked insulin or GABA release. In high concentrations,
sulfonylureas also inhibit catecholamine release from bovine adrenal chromaffin
cells and isolated guinea pig aorta. In this study, we examined the effect of
glipizide, a sulfonylurea, on dopamine release from PC12 cells and found that
neither basal nor K(+)-stimulated dopamine release was affected. Although PC12
cells expressed mRNA for the K/ATP channel, functional K/ATP channels could not
be demonstrated electrophysiologically, consistent with the lack of effect of
glipizide on dopamine release. Glipizide did, however, increase cytoplasmic
retention of the acidic dopamine metabolites, 3, 4-dihydroxyphenylacetic acid
(DOPAC) and homovanillic acid (HVA), indicating blockade of their outward
transport. The cellular accumulation of DOPAC was accompanied by reduced tyrosine
hydroxylase activity and reduced formation of dopamine and its metabolites
presumably by a negative feedback effect of the increased cytoplasmic
concentrations of DOPAC.
PMID- 10666507
TI - Characterization and modulation of [125I]iberiotoxin-D19Y/Y36F binding in the
guinea-pig urinary bladder.
AB - The radioligand binding characteristics of the Ca(2+)-activated K(+) channel
ligand [125I]iberiotoxin-D19Y/Y36F were examined in guinea-pig urinary bladder
membranes. Saturation analysis revealed a single class of high affinity binding
sites in the bladder with a K(D) value of 45.6 pM and a B(max) value of 112
fmol/mg protein. Specific binding was displaced by unlabeled iberiotoxin and
penitrem A, but not by blockers of other classes of K(+) channels including alpha
dendrotoxin, margatoxin and apamin. The indole alkaloids, paxilline and
verruculogen, significantly increased binding by 4.5- and 4.3-fold, respectively.
Tetraacetic acid derivatives such as ethylenediamine tetraacetic acid and
ethyleneglycoltetraacetic acid enhanced specific [125I]iberiotoxin-D19Y/Y36F
binding about 2.5-fold, which was not attributable to calcium chelation. This
increase was due to a significant change in ligand binding affinity (K(D)=6.3
pM), but not due to a change in the B(max), indicating that these compounds may
enhance toxin binding via allosteric interactions. Collectively, these results
demonstrate that the binding sites for [125I]iberiotoxin-D19Y/Y36F present in the
urinary bladder shows a pharmacological profile typical of maxi-K(+) channels and
can be modulated, not only by previously known indole alkaloids, but also by
tetraacetic acid analogs.
PMID- 10666508
TI - Topiramate potentiates the antiseizure activity of some anticonvulsants in DBA/2
mice.
AB - Topiramate (1-50 mg/kg, intraperitoneally (i.p.)) was able to antagonize
audiogenic seizures in DBA/2 mice in a dose-dependent manner. Topiramate at dose
of 2.5 mg/kg i.p., which per se did not significantly affect the occurrence of
audiogenic seizures in DBA/2 mice, potentiated the anticonvulsant activity of
carbamazepine, diazepam, felbamate, lamotrigine, phenytoin, phenobarbital and
valproate against sound-induced seizures in DBA/2 mice. The degree of
potentiation induced by topiramate was greatest for diazepam, phenobarbital and
valproate, less for lamotrigine and phenytoin and not significant for
carbamazepine and felbamate. The increase in anticonvulsant activity was
associated with a comparable increase in motor impairment. However, the
therapeutic index of the combination of all drugs+topiramate was more favourable
than that of antiepileptics+ saline, with the exception of carbamazepine or
felbamate+topiramate. Since topiramate did not significantly influence the total
and free plasma levels of the anticonvulsant drugs studied, we suggest that
pharmacokinetic interactions, in terms of total or free plasma levels, are not
probable. However, the possibility that topiramate can modify the clearance from
the brain of the anticonvulsant drugs studied cannot be excluded. In addition,
topiramate did not significantly affect the hypothermic effects of the
anticonvulsants tested. In conclusion, topiramate showed an additive effect when
administered in combination with some classical anticonvulsants, most notably
diazepam, phenobarbital, lamotrigine, phenytoin and valproate.
PMID- 10666509
TI - Effects of zatebradine and propranolol on canine ischemia and reperfusion-induced
arrhythmias.
AB - 1,3,4,5-Tetrahydro-7,8-dimethoxy-3[3-[[2-(3, 4-dimethoxyphenyl)
ethyl]methylamino]propyl]-2H-3-benzazepin-2-one -hy drochloride (Zatebradine) is
a specific bradycardiac agent, blocking the hyperpolarization-activated pacemaker
current (I(f)), and thus has no negative inotropic effect. The purpose of this
study was to examine whether zatebradine is effective against ischemia and
reperfusion-induced arrhythmias in dogs compared to propranolol. Arrhythmia was
induced by ligation of the left anterior descending coronary artery followed by
reperfusion. Ischemia-induced biphasic arrhythmias were suppressed in both
zatebradine and propranolol groups. During ischemia, fatal ventricular
fibrillation occurred in four dogs in the control group, 0 in the zatebradine
group, and two dogs in the propranolol group. Of the 31 dogs subjected to
reperfusion, mortality rates in the zatebradine, propranolol, and control groups
were 56%, 75%, and 86%, respectively, and there were no significant differences.
In the heart beating 10 beats/min faster than the predrug heart rate by atrial
pacing, both zatebradine and propranolol attenuated ischemia-induced arrhythmias
but did not affect reperfusion arrhythmias. Our results suggest that I(f) and/or
beta-adrenoceptors rather than the bradycardiac action might be related to the
antiarrhythmic effects during ischemia, but that they do not play a role in the
generation of the reperfusion-induced ventricular arrhythmias.
PMID- 10666510
TI - Characterization of bradykinin B(2) receptor antagonists in human and rat urinary
bladder.
AB - The effect of three selective bradykinin B(2) receptor antagonists, MEN11270 (H
DArg-Arg-Pro-Hyp-Gly-Thi-c(Dab-DTic-Oic-Arg)c(7gamma-1 0alpha)), Icatibant (H
DArg-Arg-Pro-Hyp-Gly-Thi-Ser-DTic-Oic-Arg-OH), and FR173567 ((E)-3-(6-acetamido-3
pyridyl)-N-[N-[2, 4-dichloro-3-[(2-methyl-8-quinolinyl) oxymethyl] phenyl]-N
methylaminocarbonylmethyl]acrylamide) was evaluated in the human and rat urinary
bladder in vitro and in vivo in anaesthetized rats. Bradykinin evoked a
concentration-dependent contraction of human (pD(2)=7.2) and rat (pD(2)=7.7)
detrusor muscle strips. In human preparations, all the antagonists tested
produced a rightward-shift in the concentration-response curve for bradykinin.
Schild plot analysis yielded pK(B) values of 8.4, 8.4 and 8.6 for MEN11270,
Icatibant, and FR173567, respectively. In the rat preparations the three
antagonists (at 100 nM concentration), produced a shift to the right which gave
apparent pA(2) values of 8. 2, 8.0 and 8.1 for MEN11270, Icatibant, and FR173567,
respectively. In anaesthetized rats, both MEN11270 and Icatibant (1-10 nmol/kg
i.v. ) dose dependently reduced the bradykinin (100 nmol/kg i.v.)-induced urinary
bladder contraction, their effect being prompt and long-lasting. In contrast,
FR173567 (100 nmol/kg i.v.) produced a partial and short-lasting inhibition of
bradykinin-induced bladder contractions. The present findings indicate that all
the antagonists tested recognize with similar potencies the bradykinin B(2)
receptors expressed in the detrusor muscle of both humans and rats. MEN11270 and
Icatibant possess a higher potency and longer duration of action in vivo than
FR173657, suggesting that the activity of this non-peptide antagonist in vivo is
hampered by factors unrelated to its affinity for bradykinin B(2) receptors.
PMID- 10666511
TI - Nociceptin inhibits tonic nitric oxide release in the mouse isolated proximal
colon.
AB - Nociceptin/orphanin FQ, the endogenous ligand of the opioid receptor-like (ORL1)
receptor, caused contractions in the isolated colon of the mouse. Tetrodotoxin
and the nitric oxide (NO) synthase inhibitor Nomega-nitro-L-arginine also
produced contractions which were quantitatively similar to those seen in response
to nociceptin. In the presence of either tetrodotoxin or Nomega-nitro-L-arginine,
nociceptin was unable to cause a further contraction, whereas the muscarinic
receptor agonist carbachol elicited a contractile response. Nociceptin had no
contractile activity in colonic preparations contracted by Nomega-nitro-L
arginine then relaxed by addition of the NO donor sodium nitroprusside. These
data suggest that nociceptin causes contractions of the mouse proximal colon by
inhibiting the tonic, neuronal release of NO.
PMID- 10666512
TI - The effect of endothelin-1 on lipopolysaccharide-induced cyclooxygenase 2
expression in association with prostaglandin E(2).
AB - We demonstrated previously that endothelin-1 (10(-14) to 10(-8) M) promotes
lipopolysaccharide-induced cyclooxygenase 2 expression and prostaglandin E(2)
production through endothelin ET(B) receptors effects which are up-regulated by
lipopolysaccharide. In the present study, we confirmed these findings and showed
that prostaglandin E(2) (10(-6) to 10(-5) M) inhibited the lipopolysaccharide
plus endothelin-1-induced cyclooxygenase 2 expression more profoundly as compared
to its inhibition of the lipopolysaccharide-induced cyclooxygenase 2 expression.
The endothelin ET(B) receptor selective antagonist, N-cis-2, 6-dimethylpiperidino
carbonyl-L-gamma-methyl-leucyl-D-L-methoxy carbon yl-tryptophanyl-D-norleucine
(BQ788), partly inhibited this suppression. Interestingly, the expression of
endothelin ET(B) receptors in macrophages was increased by lipopolysaccharide
plus prostaglandin E(2) (10(-8) to 10(-5) M) about 1.6-fold compared with that
evoked by lipopolysaccharide stimulation alone. We also showed that treatment
with endothelin-1 at 10(-14) M (15 min) elevated an intracellular cyclic AMP
concentration in macrophages stimulated by lipopolysaccharide or
lipopolysaccharide plus prostaglandin E(2) (10(-6) M) for 6 h, and the elevation
in the latter cells was more pronounced. These results suggested that endothelin
1 shows an opposite modulation of lipopolysaccharide-induced cyclooxygenase 2
expression in macrophages through endothelin ET(B) receptors, depending on the
level of extracellular prostaglandin E(2), and the changes of intracellular
cyclic AMP by endothelin-1 may be involved in this mechanism.
PMID- 10666513
TI - LY354740 affects startle responding but not sensorimotor gating or discriminative
effects of phencyclidine.
AB - LY354740 ?(1S,2S,5R,6S)-2-aminobicyclo[3.1.0]hexane-2, 6-dicarboxylate
monohydrate?, a selective group II metabotropic glutamate (mGlu) receptor
agonist, was recently reported to attenuate the behavioral effects of
phencyclidine (PCP) in rats. In the present study, LY354740 failed to attenuate
the discriminative stimulus properties of PCP and its disruption of prepulse
inhibition of the acoustic startle response, at a dose range which decreased
startle responding. The suggestion that mGlu group II receptor activation induces
antipsychotic effects may be premature.
PMID- 10666514
TI - Tandem sulfur-containing amino acids are epicritical determinants of dopamine
D(2) receptor pharmacology.
AB - The conserved aspartic acid that is required for ligand binding to the dopamine
D(2) receptor is followed by three tandem sulfur-containing amino acids. While
previous point mutation studies did not reveal any single one of these residues
as being critical for ligand binding, we now show that simultaneously
substituting all three with isovolumetric, non sulfur-containing amino acids
results in large decreases in the binding affinity for dopamine, (-)-raclopride
and 7-(-4(4-(2, 3-dichlorophenyl)-1-piperazinyl)butyloxy)-3, 4-dihydro-2(1H)
quinolinone (aripiprazole), but not for methylspiperone or allosteric modulators.
PMID- 10666515
TI - Spinal nerve ligation: what to blame for the pain and why.
PMID- 10666516
TI - Antagonists of excitatory opioid receptor functions enhance morphine's analgesic
potency and attenuate opioid tolerance/dependence liability.
AB - Recent preclinical and clinical studies have demonstrated that cotreatments with
extremely low doses of opioid receptor antagonists can markedly enhance the
efficacy and specificity of morphine and related opioid analgesics. Our
correlative studies of the cotreatment of nociceptive types of dorsal-root
ganglion neurons in vitro and mice in vivo with morphine plus specific opioid
receptor antagonists have shown that antagonism of Gs-coupled excitatory opioid
receptor functions by cotreatment with ultra-low doses of clinically available
opioid antagonists, e.g. naloxone and naltrexone, markedly enhances morphine's
antinociceptive potency and simultaneously attenuates opioid tolerance and
dependence. These preclinical studies in vitro and in vivo provide cellular
mechanisms that can readily account for the unexpected enhancement of morphine's
analgesic potency in recent clinical studies of post-surgical pain patients
cotreated with morphine plus low doses of naloxone or nalmefene. The striking
consistency of these multidisciplinary studies on nociceptive neurons in culture,
behavioral assays on mice and clinical trials on post-surgical pain patients
indicates that clinical treatment of pain can, indeed, be significantly improved
by administering morphine or other conventional opioid analgesics together with
appropriately low doses of an excitatory opioid receptor antagonist.
PMID- 10666517
TI - Computer-assisted infrared thermographic study of axon reflex induced by
intradermal melittin.
AB - The aim of the present study was to investigate whether melittin, the principal
toxin of the honeybee (Apis mellifera) venom, can be used as an algogenic agent
in the study of pain in humans. Five micrograms of melittin in 0.5 ml of saline
was intradermally injected into the volar aspect of the forearm. Resultant pain
was scored by a visual analogue scale (VAS), and skin temperature change was
analyzed by means of a computer-assisted infrared thermography. Intradermal
melittin temporarily produced severe pain, followed by a sustained increase in
skin temperature. The skin temperature increase peaked in about 10 min and
outlasted 1 h. Topical application of 10% lidocaine gel did not significantly
suppress the melittin-induced pain, but markedly suppressed both the increase in
the peak temperature and the area of temperature increase. In conclusion, 5
microg of melittin is sufficient to produce pain in humans and 10% lidocaine gel
differentially decreases the melittin-induced axon reflex without any significant
analgesic effect.
PMID- 10666518
TI - Secondary hyperalgesia persists in capsaicin desensitized skin.
AB - Several lines of evidence suggest that secondary hyperalgesia to punctate
mechanical stimuli arises from central sensitization to the input from primary
afferent nociceptors. Conventional C-fiber nociceptors respond to heat stimuli
and yet heat hyperalgesia is absent in the region of secondary hyperalgesia. This
evidence suggests that the central sensitization to nociceptor input does not
involve heat sensitive nociceptors. To test this hypothesis, we investigated
whether desensitization of heat sensitive nociceptors by topical application of
capsaicin led to an alteration in the secondary hyperalgesia. Two 2x2 cm areas on
the volar forearm, separated by 1 cm, were treated in 10 healthy volunteers. One
of the areas was desensitized by treatment with 10% topical capsaicin (6 h/day
for 2 days). The other site served as vehicle control. Hyperalgesia was produced
2 days later by an intradermal injection of capsaicin (50 microg, 10 microl) at a
point midway between the two treatment areas. Secondary hyperalgesia to noxious
mechanical stimuli was investigated by using a blade probe (32 and 64 g) attached
to a computer-controlled mechanical stimulator. In the area of topical capsaicin
treatment, there was a marked increase in heat pain threshold and decrease in
heat pain ratings indicating a pronounced desensitization of heat sensitive
nociceptors. However, touch threshold and pain to pinching stimuli were not
significantly altered. The intradermal capsaicin injection led to the development
of a similar degree of secondary hyperalgesia at both the vehicle and capsaicin
treatment areas. These results indicate that capsaicin insensitive nociceptive
afferents play a dominant role not only in normal mechanical pain but also in
secondary hyperalgesia to noxious mechanical stimuli.
PMID- 10666519
TI - Effects of intrathecal administration of ziconotide, a selective neuronal N-type
calcium channel blocker, on mechanical allodynia and heat hyperalgesia in a rat
model of postoperative pain.
AB - Ziconotide (SNX-111), a selective blocker of neuronal N-type voltage-sensitive
calcium channels, is antinociceptive when it is administered intrathecally. It is
currently under clinical investigation for the treatment of malignant and non
malignant pain syndromes. The present study was undertaken to compare and
contrast antinociceptive properties of ziconotide, morphine and clonidine in a
rat model of post-operative pain. Post-operative pain was produced by making a
longitudinal incision through the skin, fascia, and muscle of the plantar aspect
of the left hindpaw. This procedure produced immediate (0.5 h after surgery) and
long-lasting (4-7 days post-surgery) heat hyperalgesia and mechanical allodynia
in the injured hindpaw. Pain thresholds in the contralateral hindpaw were
unaffected. Administered one day after incisional surgery, intrathecal ziconotide
blocked established heat hyperalgesia in the injured hindpaw in a dose-dependent
manner yielding an ED(50)4 h) but reversible (<24 h) blockade of established
mechanical allodynia. Administered one day after surgery, intrathecal bolus
injection of morphine dose-dependently blocked heat hyperalgesia in the injured
hindpaw with an ED(50) of 1.6 microg (2.1 nmol) and heat nociceptive responses in
the normal hindpaw with an ED(50) of 2.7 microg (3.6 nmol). The effects were
immediate and short-lasting (=1 h). Intravenous bolus injection of 3 mg/kg (1.1
micromol/kg) ziconotide, administered either before or after incisional surgery,
had no effect on thermal pain thresholds measured in either the injured or normal
hindpaw. In contrast, intraperitoneal injections of 2 mg/kg (2.6 micromol/kg)
morphine and 2.5 mg/kg (9.4 micromol/kg) clonidine blocked heat hyperalgesia in
the injured hindpaw; morphine, but not clonidine, also elevated thermal (heat)
nociceptive response thresholds in the normal hindpaw. The results of this study
show that intrathecal ziconotide is antinociceptive in a rat incisional model of
post-operative pain and is more potent, longer acting, and more specific in its
actions than intrathecal morphine.
PMID- 10666520
TI - Cytokine involvement in dynorphin-induced allodynia.
AB - Dynorphin A is an endogenous opioid peptide, which has previously been shown to
produce a long-lasting allodynia and hyperalgesia in mice, behavioral states
consistent with signs of clinically observed neuropathic pain. This dynorphin
induced allodynia was used as a pharmacological, central model of neuropathic
pain. In this study, we examined the involvement of the cytokine IL-1beta, the
transcription factor nuclear factor kappa B (NF-kappaB), and de novo protein
synthesis in the development of allodynia induced by intrathecal (i.t.)
administration of dynorphin in male ICR mice. Pretreatment with the protein
synthesis inhibitor cycloheximide (0. 3-85nmol), the NF-kappaB inhibitor
pyrrolidinedithiocarbamate (PDTC) (0.001-1000pmol), the IL-1 receptor antagonist
(IL-1ra) protein (0. 01-100ng), the caspase-1 inhibitor (YVAD) (0.1-300pmol), and
the anti-inflammatory cytokine IL-10 (0.1-300ng) all dose-dependently reduced the
induction of dynorphin-induced allodynia. Finally, IL-10 administered within the
first 24h after the dynorphin insult prevented the development of chronic
allodynia. These results demonstrate that the anti-inflammatory cytokines IL-10
and IL-1ra impede the development of dynorphin-induced allodynia. These results
also suggest that production of new proteins through NF-kappaB activation is
required for the induction of allodynia. We speculate that IL-1ra, IL-10, PDTC
and cycloheximide interfere with the central pro-inflammatory cascade. Modulation
of cytokine activity in the spinal cord may therefore prove to be an effective
therapeutic strategy for the treatment of chronic pain.
PMID- 10666521
TI - Involvement of presurgical pain in preemptive analgesia for orthopedic surgery: a
randomized double blind study.
AB - Preemptive analgesia (PA) is effective in animal models but its clinical
effectiveness remains controversial. We examined the effect of preexisting pain
on PA. Subjects were recruited from patients needing orthopedic surgery. Some had
presurgical pain (fracture surgery and arthritic surgery), while others had no
presurgical pain (removal surgery for a tumor, nail or plate). Epidural morphine
or a saline control was given preemptively before surgery and maintained until
skin closure. Following skin closure, naloxone or placebo was injected
intravenously to erase the aftereffects of the morphine. After total recovery,
the PCA pump was set to inject epidural morphine. Pain intensity after surgery
was measured by a visual analogue scale (VAS), and the amount of morphine used
within 48h after surgery. PA was significantly effective for removal surgery, but
ineffective for fracture or arthritic surgery. For the fracture and arthritic
surgery PA treatment groups, there was a significant correlation between pre- and
postsurgical (6h) spontaneous pain, while the corresponding control groups showed
no significant correlation. Postsurgical VAS values in the fracture and arthritic
surgery control groups increased significantly compared with presurgical VAS
values. PA was effective when presurgical pain was absent, but ineffective when
presurgical pain was present. We propose that central sensitization is already
established by presurgical pain, and preserved until the termination of surgery.
The ineffectiveness of PA did not depend on whether the pain was acute (fracture
surgery) or chronic (arthritic surgery).
PMID- 10666522
TI - Antihyperalgesic effects of intrathecally administered magnesium sulfate in rats.
AB - Intrathecal administration of MgSO(4) is reported to cause paralysis. However,
the characteristic sensory disturbances have not been thoroughly investigated. We
examined the effect of intrathecally administered MgSO(4) on the nociceptive
threshold, using three different nociceptive measures, formalin test, hot plate
test and paw pressure test in rats. The dose of MgSO(4) was 30, 100 or 300
microg. In acute nociceptive tests, intrathecal MgSO(4) did not cause any
significant changes in the pain threshold. However, phase 2 of the formalin test
was suppressed dose-dependently. It is known that spinal NMDA receptors are
involved in the changes seen during the second (tonic) phase of the formalin test
and in vitro studies showed that Mg(2+) can cause voltage-dependent blockade of
NMDA receptor channel in the neurons of spinal dorsal horn. Thus, the suppressive
effect of intrathecally administered MgSO(4) on the tonic inflammation-evoked
behavior is mediated by the spinal NMDA receptors. Our results suggest that
intrathecal administration of MgSO(4) may be therapeutically beneficial for
patients with tonic pain involving the spinal NMDA receptors.
PMID- 10666523
TI - Electronic diary assessment of pain, disability and psychological adaptation in
patients differing in duration of pain.
AB - Computerized diary measurement of pain, disability and psychological adaptation
was performed four times a day for 4 weeks in 80 patients with various duration
of unexplained pain. Reported are (1) the temporal characteristics and stability
of pain report during the 4-week measurement period, (2) the association between
pain duration and pain report, disability and general psychopathology, and (3)
the accordance between diary assessment versus questionnaire assessment of pain,
disability and psychological adaptation. No evidence of instrument reactivity was
found: pain report was stable across the 4-week period. However, pain report
appeared to be highly variable both between and within days. About half the
patients showed a clear increasing trend in pain during the day. Several
differences were found between subgroups of patients varying in pain duration.
Patients with less than 6 months of pain reported significantly less pain
intensity, disability and fatigue than patients whose pain persisted for more
than 6 months. Pain coping and responses to pain behaviors by the spouse also
differed for the subgroups: longer pain duration was associated with increased
catastrophizing and solicitous responses from the spouse. Comparison of scores
obtained with diary versus questionnaire assessment indicated moderate
correlations for most variables. Retrospective (questionnaire) assessment of pain
intensity yielded significantly higher pain scores than diary assessment.
PMID- 10666524
TI - Mechanisms underlying the effects of remote noxious stimulation and mental
activities on exteroceptive jaw reflexes in man.
AB - Successive inhibitory, excitatory, inhibitory and excitatory reflexes (the Q, R,
S and T waves of the post-stimulus electromyographic complex (PSEC)), evoked by
applying non-painful taps to an incisor tooth, were recorded from the jaw-closing
muscles of 15 subjects. The effects on these reflexes of the subjects undertaking
mental exercises (MEx) in the form of arithmetic calculations were compared with
those of remote noxious stimulation (RNS; application of 3 degrees C to a hand).
This was done to investigate whether the previously established effects of RNS
were likely to be related to a change in the subject's mental state and/or to
direct nociceptive mechanisms. Both MEx and RNS caused increases in EMG activity
around the Q-R and S-T transitions of the PSEC, which resulted principally from
shortenings of the inhibitory Q and S waves. Reducing the intensity of the tap
stimuli, which mimicked condition-induced disinhibition, caused shortenings of
the inhibitory waves at latencies similar to the shortenings induced by MEx or
RNS. The magnitude of the RNS-induced effect on the ST segment of the PSEC was
greater (P<0.01) than that on the QR segment. By contrast, MEx induced similar
effects on both segments. Regression analyses were performed for the relationship
between condition-induced changes in amplitude of the excitatory waves and their
control amplitudes. These analyses were performed to reveal any condition-induced
inhibition or facilitation of the tap-induced influences on the motoneurons.
Overall, the evidence suggested that: (1) mental exercise induced a similar
degree of inhibition of the two tap-induced inhibitory jaw reflexes and a
facilitation of the excitatory ones, and (2) remote noxious stimulation induced
an inhibition of the second tap-induced inhibitory reflex which was greater than
that of the first one, and an inhibition of the first excitatory reflex. Thus,
although factors related to altered mental activity could play a role in the
modulation of jaw reflexes by RNS, the differences between the effects of MEx and
RNS suggest that alternative or complementary mechanisms are also likely to be
involved.
PMID- 10666525
TI - Treatment outcome of chronic non-malignant pain patients managed in a danish
multidisciplinary pain centre compared to general practice: a randomised
controlled trial.
AB - This randomised controlled study investigated the effect of outpatient
multidisciplinary pain centre treatment (MPT) compared with treatment by a
general practitioner after initial supervision by a pain specialist (GP-group)
and with a group of patients waiting for 6 months before treatment was initiated
(WL-group). One-hundred-and-eighty-nine chronic non-malignant pain patients were
studied. At referral, and after 3 and 6 months patients filled in questionnaires
evaluating pain intensity, health related quality of life (HRQL) and use of
analgesics. HRQL was evaluated using the Medical Outcome Study-Short Form (SF
36), the Hospital Anxiety and Depression scale (HAD) and the Psychological
General Well-being Scale (PGWB). After 6 months patients allocated to MPT (n=63)
reported statistically significant reduction in pain intensity (VAS-score,
P<0.001), improvement in psychological well-being (PGWB, P<0.001), quality of
sleep (P<0.05) and physical functioning (SF-36-Phycical Functioning, P<0.05). No
improvements were seen in the GP-group (n=63). In the WL-group (n=63) a
statistically significant deterioration was observed in PGWB-scores, HAD-scores
and in 6 of 8 SF-36-subscores (P = 0.05). A reduction in use of opioids
administered on demand was obtained in the group receiving MPT (P<0.001). In the
MPT- and GP-groups a decrease in the use of short acting opioids was observed
(P<0.01). No change in use of analgesics was seen in the WL-group. The study
showed that (i) in the MPT-group there was a significant reduction in pain
intensity and improvement of HRQL compared to the WL-group, and (ii) the mere
establishment of a pain diagnosis and a pain management plan by a pain specialist
was not sufficient to enable the referring GP to manage severely chronic pain
patients.
PMID- 10666526
TI - Modulation of nociceptive transmission by NMDA/glycine site receptor in the
ventroposterolateral nucleus of the thalamus.
AB - NMDA-type glutamate receptors are involved in the generation and maintenance of
altered pain states. In the present study, we examined the effect of an NMDA
glycine site antagonist, GV196771A [E-4, 6-dichloro-3-(2-oxo-1-phenyl-pyrrolidin
3-ylidenemethyl)-1H- indole-2- carboxylic acid sodium salt], on responses to
noxious stimuli both in normal rats and during peripheral mononeuropathy induced
by chronic constriction injury (CCI) of the sciatic nerve. In one series of
experiments, activity of nociceptive neurons in the ventroposterolateral (VPL)
nucleus of the thalamus was recorded in response to pressure stimuli to the
contralateral hindpaw. Intravenous injection (iv) of the glycine antagonist had
no effect on these cells in normal rats. When tested in rats with CCI induced 2-3
weeks previously, however, GV196771A (0.125, 0.5 and 2.0mg/kg) blocked responses
to noxious stimulation in a dose-dependent and reversible manner. Morphine
(0.5mg/kg, iv) and the NMDA channel blocker MK801 (0.1mg/kg, iv) suppressed
noxious stimulus-evoked activity of VPL neurons in both normal and CCI-treated
rats. MK801 also decreased the responses of non-nociceptive neurons to brush
stimulation in both sets of animals, in contrast to the glycine antagonist which
did not alter the responses of these cells. Similar results were obtained from a
series of behavior experiments in which the latency for paw withdrawal from heat
stimulation was measured in normal and CCI-treated rats. GV196771A (3 and
10mg/kg) injected orally, reduced the hyperalgesic response in the treated rats
but did not change the withdrawal latency in normal rats. Taken together, these
findings suggest that block of the NMDA receptor decreases nociceptive
transmission in the thalamus and can modulate hyperalgesic states. GV196771A and
glycine antagonists in general may represent innovative and safe agents for the
treatment of neuropathic pain.
PMID- 10666527
TI - Factors associated with anxiety and depression in facial arthromyalgia.
AB - Facial arthromyalgia (temporomandibular joint pain dysfunction syndrome, TMD) is
a chronic pain condition of unknown origin. This paper examines the extent to
which the condition is associated with symptoms of anxiety and depression. It
also identifies factors which may be predictive of raised levels of these two
moods and of the presence of clinical anxiety and clinical depression. Self
report measures of pain beliefs, coping strategies, pain intensity, disability
and mood were administered to a sample of 80 facial arthromyalgia patients of
differing chronicity. The results showed anxious mood to be associated with
several factors including beliefs that pain is itself worsened by negative mood,
passive coping in terms of catastrophising about pain, and speech problems.
Depressed mood was associated with catastrophising and disability in the form of
disturbance in taste and digestion. These factors may be considered as potential
targets for therapy, rather than the orthodox objective of pain relief.
PMID- 10666529
TI - Validity of the pain anxiety symptoms scale (PASS): prediction of physical
capacity variables.
AB - Anxious responses to pain may lead to avoidance of behavior expected to produce
pain. McCracken et al. (1992) developed the Pain Anxiety Symptoms Scale (PASS) to
assess anxiety related specifically to pain. Efforts to validate the scale,
however, have been confined mostly to examining associations between the PASS and
other self-report instruments. This study tested whether PASS scores were related
to behavioral performance variables recorded by therapists during a physical
capacity evaluation. Participants were 98 male patients with persistent pain
referred to two industrial rehabilitation centers. PASS scores were correlated
negatively with amount of weight lifted and carried, and results of hierarchical
regressions showed that PASS scores accounted for additional variance in these
variables when measures of trait anxiety, depression and pain severity were
controlled. However, we did not replicate the findings of McCracken et al. (1992)
that PASS scores accounted for variance in self-reported disability with trait
anxiety, depression or pain severity controlled. Results extend the validity of
the PASS and are consistent with models of fear of pain: patients with high PASS
scores may avoid potentially painful physical exertion to reduce their fear.
PMID- 10666530
TI - Characteristics of ectopic discharges in a rat neuropathic pain model.
AB - Injured afferent neurons produce spontaneous activity that is generated away from
the normal impulse generation site. Since this activity, referred to as ectopic
discharges, may play a significant role in neuropathic pain, it is important to
systematically analyze the activity in various pain states. The present study
used the segmental spinal nerve injury model of neuropathic pain to quantify the
ectopic discharges from injured afferents in the neuropathic rat under various
conditions. All aspects of measured ectopic discharges declined as postoperative
time lengthened. Neuropathic pain behaviors declined in a similar fashion over
the same time period. Surgical sympathectomy on neuropathic animals lowered the
level of ectopic discharges along with neuropathic pain behaviors. The data
indicate that the level of ectopic discharges is well correlated with that of
pain behaviors in a rat neuropathic pain model, and this reinforces the
supposition that ectopic discharges are important to the maintenance of
neuropathic pain behaviors. The data suggest that there are two components of
ectopic discharge generator mechanisms: sympathetically dependent and
sympathetically independent components.
PMID- 10666528
TI - Bilateral behavioral and regional cerebral blood flow changes during painful
peripheral mononeuropathy in the rat.
AB - A unilateral chronic constriction injury (CCI) of the sciatic nerve produced
bilateral effects in both pain related behaviors and in the pattern of forebrain
activation. All CCI animals exhibited spontaneous pain-related behaviors as well
as bilateral hyperalgesia and allodynia after CCI. Further, we identified changes
in baseline (unstimulated) forebrain activation patterns 2 weeks following CCI by
measuring regional cerebral blood flow (rCBF). Compared to controls, CCI
consistently produced detectable, well-localized and typically bilateral
increases in rCBF within multiple forebrain structures in unstimulated animals.
For example, the hindlimb region of somatosensory cortex was significantly
activated (22%) as well as multiple thalamc nuclei, including the ventral medial
(8%), ventral posterior lateral (10%) and the posterior (9%) nuclear groups. In
addition, several forebrain regions considered to be part of the limbic system
showed pain-induced changes in rCBF, including the anterior dorsal nucleus of the
thalamus (23%), cingulate cortex (18%), retrosplenial cortex (30%), habenular
complex (53%), interpeduncular nucleus (45%) and the paraventricular nucleus of
the hypothalamus (30%). Our results suggest that bilateral somatosensory and
limbic forebrain structures participate in the neural mechanisms of prolonged
persistent pain produced by a unilateral injury.
PMID- 10666531
TI - Opioid inhibition of formalin-induced changes in plasma extravasation and local
blood flow in rats.
AB - Hindpaw injection of dilute formalin produces brief (Phase 1) and persistent
(Phase 2) nociceptive responses in the rat. We recently showed that systemically
administered remifentanil during Phase 1 interacted with peripheral opioid
receptors to delay the onset and termination of Phase 2 (Taylor et al., 1997b).
To test the hypothesis that opioid inhibition of proinflammatory events during
Phase 1 contributed to this delay, we evaluated the effects of remifentanil on
the time course of formalin-induced inflammation. We found that formalin
increased paw thickness (edema), plasma extravasation and local blood flow within
minutes of its injection, i.e. during Phase 1. Each of these responses was
blocked during remifentanil administration (30 microg/kg i.v. bolus, followed 90
s later with a 15 microg/kg/min infusion for 13.5 min), indicating that opioids
inhibit Phase 1 inflammation. Opioid blockade of the blood flow response could be
reversed with a peripherally-acting opioid antagonist, naloxone methiodide,
indicating that remifentanil acted upon peripheral opioid receptors. Although the
administration of remifentanil during Phase 1 did not reduce the magnitude of
inflammatory responses during Phase 2, it did delay the onset and termination of
edema during Phase 2. As this corresponds to the effects of remifentanil on
nociceptive responses during Phase 2, we suggest that opioid analgesics act upon
peripheral sites to inhibit inflammation during Phase 1, leading to a delay in
the temporal profile of inflammatory (and likely nociceptive) responses during
Phase 2.
PMID- 10666532
TI - Interactions of intrathecally administered ziconotide, a selective blocker of
neuronal N-type voltage-sensitive calcium channels, with morphine on nociception
in rats.
AB - Ziconotide is a selective, potent and reversible blocker of neuronal N-type
voltage-sensitive calcium channels (VSCCs). Morphine is an agonist of mu-opioid
receptors and inhibits N-type VSCC channels via a G-protein coupling mechanism.
Both agents are antinociceptive when they are administered intrathecally
(spinally). The present study investigated the acute and chronic (7-day)
interactions of intrathecally administered ziconotide and morphine on nociception
in several animal models of pain. In the acute study, intrathecal bolus
injections of morphine and ziconotide alone produced dose-dependent inhibition of
formalin-induced tonic flinch responses and withdrawal responses to paw pressure.
The combination of ziconotide and morphine produced an additive inhibition of
formalin-induced tonic flinch responses and a significant leftward shift of the
morphine dose-response curve in the paw pressure test. After chronic (7-day)
intrathecal infusion, ziconotide enhanced morphine analgesia in the formalin
test. In contrast, chronic intrathecal morphine infusion produced tolerance to
analgesia, but did not affect ziconotide antinociception. Antinociception
produced by ziconotide alone was the same as that observed when the compound was
co-administered with morphine to morphine-tolerant rats. In the hot-plate and
tail immersion tests, chronic intrathecal infusion of morphine lead to rapid
tolerance whereas ziconotide produced sustained analgesia with no loss of potency
throughout the infusion period. Although ziconotide in combination with morphine
produced an apparent synergistic analgesic effects during the initial phase of
continuous infusion, it did not prevent morphine tolerance to analgesia. These
results demonstrate that (1) acute intrathecal administrations of ziconotide and
morphine produce additive or synergistic analgesic effects; (2) chronic
intrathecal morphine infusion results in tolerance to analgesia but does not
produce cross-tolerance to ziconotide; (3) chronic intrathecal ziconotide
administration produces neither tolerance nor cross-tolerance to morphine
analgesia; (4) intrathecal ziconotide does not prevent or reverse morphine
tolerance.
PMID- 10666533
TI - Sleep arousal response to experimental thermal stimulation during sleep in human
subjects free of pain and sleep problems.
AB - Although the interaction between sleep and pain is generating considerable
interest (NIH Technology Assessment Panel, 1996), it is still unknown if chronic
pain is the cause or effect of poor sleep. To further this understanding,
subjects free of pain and sleep problems need to be studied in order to assess
their response to pain during sleep, defined as a behavioral and a physiological
state in which sensory processing is altered. (For example, while auditory
perception remains active, other sensory inputs are facilitated, attenuated, or
suppressed (Velluti, 199746 degrees C) was statistically greater in the lighter
sleep stage 2 (48.3%) than in the deeper stages 3&4 (27.9%). A nocifensive
behavioral-motor response was associated with only 2.5% of the 351 heat pain
stimuli. Two other markers of sleep quality-sleep stage shift and awakening-were
not influenced by the thermal stimuli. None of the subjects demonstrated any
burns in the morning following the thermal stimulations applied during sleep. We
conclude that the processing of nociceptive inputs is attenuated across sleep
stages.
PMID- 10666534
TI - Efficacy of a vibratory stimulus for the relief of HIV-associated neuropathic
pain.
AB - Pain related to HIV disease is frequently debilitating. Of the many pain
syndromes that occur in persons with HIV, distal symmetrical polyneuropathy
(DSPN) is particularly devastating. Because DSPN often responds, at best, only
partially to available pharmacologic interventions, non-pharmacologic
interventions need to be investigated. Vibration has been suggested to be
effective for reducing pain in other populations with chronic pain. This
randomized, sham-controlled, double-masked study tested the short-term efficacy
of a 45-min vibration treatment for DSPN foot pain in persons infected with HIV.
Vibration therapy was delivered using a portable platform foot vibrator that
provided stimulation at a frequency of 60 Hz. For all patients, the control box
for the vibrator emitted an audible hum and part of the control box lit up during
treatment, but only patients randomized to active treatment received vibration.
Pain intensity (0-10) was measured immediately prior to and after treatment.
Subjects were also questioned regarding pain relief (0-100%) immediately after
the treatment. The mean percentage pain relief was 61.0+/-33.1% (median 70.0;
range 0-100) for all patients, 67.3+/-34.0% (median 80.0; range 0-100) for
vibration patients, and 55.0+/-32.0% (median 60.0; range 0-100) for sham
patients. No statistically significant differences were found between the
vibration and sham groups with respect to percentage pain relief (Mann-Whitney
test; P=0.19) or the pre- and post-treatment current-pain difference (Mann
Whitney test; P=0.92). These results underscore the necessity for control groups
in studies of non-pharmacologic therapies for pain.
PMID- 10666535
TI - Differences in somatic perception in female patients with irritable bowel
syndrome with and without fibromyalgia.
AB - BACKGROUND: Irritable bowel syndrome (IBS) and fibromyalgia (FM) are considered
chronic syndromes of altered visceral and somatic perception, respectively.
Because there is a significant overlap of IBS and FM, shared pathophysiological
mechanisms have been suggested. Although visceral perception has been well
studied in IBS, somatic perception has not. AIMS: To compare hypervigilance and
altered sensory perception in response to somatic stimuli in patients with IBS,
IBS+FM, and healthy controls. METHODS: Eleven IBS females (mean age 40), 11
IBS+FM females (mean age 46), and ten healthy female controls (mean age 39) rated
pain perception in response to pressure stimuli administered to active somatic
tender points, non-tender control points and the T-12 dermatome, delivered in a
predictable ascending series, and delivered in an unpredictable randomized
fashion (fixed stimulus). RESULTS: Although IBS patients had similar pain
thresholds during the ascending series compared with controls, they were found to
have somatic hypoalgesia with higher pain thresholds and lower pain frequency and
severity during fixed stimulus series compared with IBS+FM patients and controls
(P<0.05). Patients with IBS+FM were more bothered by the somatic stimuli and had
somatic hyperalgesia with lower pain thresholds and higher pain frequency and
severity. CONCLUSIONS: Both hypervigilance and somatic hypoalgesia contribute to
the altered somatic perception in IBS patients. Co-morbidity with FM results in
somatic hyperalgesia in IBS patients.
PMID- 10666536
TI - Spontaneous activity of axotomized afferent neurons after L5 spinal nerve injury
in rats.
AB - After mechanical injury of a peripheral nerve some axotomized afferent neurons
develop spontaneous activity, which is thought to trigger abnormal pain behavior
in rats and neuropathic pain in humans. Here, we analysed the ectopic activity in
axotomized afferent fibers recorded from the L5 dorsal root in different time
periods after L5 spinal nerve lesion and the effects of sympathectomy on it. The
following results were obtained: (1) Up to 6 hours after spinal nerve transection
there was almost no spontaneous activity in axotomized afferents, except short
lasting injury discharges at the time of transection; (2) Three to 8 days
following spinal nerve lesion, the rate of spontaneous activity was 7.3+/-7.7
imp/s (mean+/-SD, median 5.0 imp/s, n=204); 41.6% of the spontaneously active
afferent neurons exhibited a bursting pattern with interspike intervals of 32.4+/
18.3 ms; (3) Twenty to 53 days after nerve lesion the rate of spontaneous
activity had decreased significantly to 3.4+/-4.3 imp/s (median 2.6 imp/s,
n=120). The frequency of bursting and non-bursting neurons remained roughly the
same; (4) In sympathectomized rats, 15-45 days following spinal nerve lesion, the
mean discharge rate was 3.8+/-4.3 imp/s (median 2. 3 imp/s, n=255). However, the
percentage of bursting neurons and the intraburst frequency decreased
significantly; (5) Spontaneous activity occurred in afferent A-fibers but not in
afferent C-fibers. These results suggest that ectopic activity in axotomized
afferent neurons develops within the first days after L5 spinal nerve lesion,
decreases with time and is only marginally dependent on the sympathetic
innervation. There was a positive correlation between this ectopic activity and
the allodynia-like behavior in spinal nerve-lesioned rats.
PMID- 10666537
TI - Distribution and regulation of alpha(2)-adrenoceptors in rat dorsal root ganglia.
AB - Using in situ hybridization with riboprobes the distribution of alpha(2A)-,
alpha(2B)- and alpha(2C)-adrenoceptor mRNAs were studied in normal rat dorsal
root ganglia and after unilateral peripheral nerve injury (total nerve
transection) or inflammation. The most common adrenoceptor mRNA was of the
alpha(2C) subtype (almost 80% of all neuron profiles) followed by the alpha(2A)
subtype (almost 20%), whereas alpha(2B)-adrenoceptor mRNA was only found in small
numbers of neuron profiles. The most dramatic effect of peripheral nerve injury
was observed for the alpha(2A)-adrenoceptor mRNA, which increased to 45% of all
neuron profiles. In contrast, alpha(2C) adrenoceptor mRNA showed a small decrease
in this situation. Carrageenan-induced peripheral inflammation did not affect the
percentage of alpha(2A)- or alpha(2C)-adrenoceptor mRNA-positive profiles. These
findings suggest that, if any of the alpha(2) adrenoceptor, the alpha(2A) subtype
represents the most likely candidate in DRG neurons to be involved in
sympathetically maintained pain.
PMID- 10666538
TI - No effect of sympathetic sudomotor activity on capsaicin-evoked ongoing pain and
hyperalgesia.
AB - BACKGROUND: Complex regional pain syndromes (causalgia and RSD) can be relieved
by blockade of the sympathetic efferent activity. The mechanisms of
sympathetically maintained pain (SMP) are unclear. So far an adrenergic
interaction between sympathetic vasoconstrictor neurons and nociceptors has been
proposed. Alternatively, a cholinergic coupling of sympathetic sudomotor neurons
and nociceptors is possible. OBJECTIVE: To determine the effect of cutaneous
sympathetic sudomotor activity on pain induced by primary afferent C-nociceptor
activation with capsaicin in humans. METHODS: In 10 healthy volunteers capsaicin
was injected into the forearm skin to induce ongoing pain and dynamic and
punctate mechanical hyperalgesia. Intensity of pain and hyperalgesia and area of
hyperalgesia (planimetry) were assessed. The local skin temperature at the
application and measurement sites was kept constant at 35 degrees C. In each
individual the analyses were performed during the presence of low and high
sympathetic sudomotor skin activity induced by whole-body temperature changes
with a thermal suit. By altering whole-body temperature from a moderately warm to
an intensely warm state, sympathetic sudomotor activity is modulated selectively
in the widest range that can be achieved physiologically while sympathetic
vasoconstrictor activity is continuously inhibited. The degree of sudomotor
discharge was monitored by measuring cutaneous sweat production at the forearm
with the colour indicator ponso-red. The inhibition of vasocontrictor discharge
was monitored by measuring cutaneous blood flow at the index finger with laser
Doppler flowmetry. RESULTS: The intensity and spatial distribution of capsaicin
evoked ongoing pain and dynamic and punctate mechanical hyperalgesia were not
significantly different during the presence of high and low sympathetic sudomotor
discharge. CONCLUSIONS: Cutaneous sympathetic sudomotor activity does not
influence capsaicin induced pain and mechanical hyperalgesia.
PMID- 10666539
TI - Effect of propranolol and granisetron on experimentally induced pain and
allodynia/hyperalgesia by intramuscular injection of serotonin into the human
masseter muscle.
AB - We have previously reported that intramuscular injection of serotonin (5-HT) into
the masseter muscle elicits pain and allodynia/hyperalgesia in healthy subjects.
The aim of this study was to investigate whether the 5-HT(3) receptor antagonist
granisetron or 5-HT(1A) receptor antagonist propranolol can reduce 5-HT induced
pain and allodynia/hyperalgesia in the masseter muscle. Twenty-four healthy
individuals (12 males and 12 females) without pain from the masseter muscle
region participated. They were examined clinically including tenderness to
digital palpation (TDP) and pressure pain threshold (PPT) of the masseter muscle.
5-HT in combination with granisetron or propranolol was randomly injected on one
side in a double-blind manner. 5-HT in combination with saline was used on the
contralateral side. After the injections the pain intensity and PPT were recorded
10 times during 30min. After the last recording the TDP was assessed again. The
injections were repeated with the other antagonist within 1 week. All three
combinations of substances elicited pain after injection, which lasted for 5
8min. 5-HT induced significantly more pain than granisetron+5-HT and
propranolol+5-HT. The TDP increased significantly after injection of all
combinations of substances, but there was no significant difference between them.
The PPT decreased significantly after injection of 5-HT and increased
significantly after injection of granisetron+5-HT, while it did not change
significantly after injection of propranolol+5-HT. The difference between 5-HT
and granisetron+5-HT was significant. In conclusion, the results of this study
indicate that injection of granisetron and propranolol into the human masseter
muscle reduces pain induced by local administration of 5-HT, but that the effect
of granisetron is stronger than that of propranolol. In addition, granisetron
totally abolishes allodynia/hyperalgesia.
PMID- 10666540
TI - The relation between pain beliefs, negative thoughts, and psychosocial
functioning in chronic pain patients.
AB - Cognitions and beliefs appear important in predicting adjustment to chronic pain.
The current study examines how cognitions and beliefs are related to psychosocial
functioning. One hundred and sixty-three chronic pain out-patients were assessed.
Regression analyses were performed using scores on the Pain Beliefs and
Perceptions Inventory and the Inventory of Negative Thoughts in Response to Pain
as predictor variables and responses to the West Haven Yale Multidimensional Pain
Inventory as criterion variables. Pain cognitions and pain beliefs were
correlated. After controlling for demographics, employment status and pain
severity, pain beliefs and cognitions accounted for a significant amount of the
variance in general activity, pain interference, and affective distress. Negative
cognitions, particularly negative self-statements, were more predictive of
outcome than pain beliefs. Although these data are correlational, they provide
additional support for a biopsychosocial model of adjustment to chronic pain.
PMID- 10666541
TI - Long-term changes in sciatic-evoked A-fiber dorsal horn field potentials
accompany loose ligation of the sciatic nerve in rats.
AB - The goal of the present study was to examine whether loose ligation of the
sciatic nerve was associated with long-term changes in neuronal excitability in
the spinal dorsal horn in urethane-anesthetized rats. The sciatic nerve was
stimulated with 0. 1 ms long pulses at 1 stimulus/5 min, and the evoked dorsal
horn field potentials remained stable in the absence of tetanic stimulation. In
one set of control and ligated animals, high-frequency tetanic stimulation was
applied to the nerve at 50 Hz (one 400 ms train of twenty 0.1 ms pulses), and the
field potentials were recorded again (1 stimulus/5 min) for up to 4 h post
tetanus. In control animals, this protocol produced significant increases in
field potential amplitudes at 15, 30 and 60 min post-tetanus. Interestingly,
after this time the evoked field potentials began to decrease, and attained less
than 50% of their pre-tetanic values at 240 min post-tetanus. In contrast, in
ligated rats the pattern of post-tetanic potentiation was significantly different
as the increases in amplitude persisted, and at 240 min post-tetanus the field
potentials were almost twice their baseline values. In another set of control and
ligated animals, low-frequency tetanic stimulation was applied at 5 Hz (one 400
ms train of two 0.1 ms pulses). Again a differential pattern of post-tetanic
responses between control and ligated rats was seen. In control animals, a
significant decrease in amplitude was evident within 30 min, and the depression
became progressively more pronounced as the field potentials attained about a
quarter of their baseline values at 180 min, and remained at these low levels at
240 min post-tetanus. On the other hand, in ligated animals, the depression was
not significant, and at 240 min post-tetanus the field potentials were still at
about 80% of their baseline values. These data demonstrate that long-term changes
in spinal dorsal horn neuronal excitability accompany sciatic ligation to perhaps
contribute to the development of neuropathic pain. These changes may result from
a lessening of normally strong inhibitory processes in the spinal dorsal horn to
generate conditions which favor post-tetanic potentiation over depression of
dorsal horn neuronal responses.
PMID- 10666542
TI - Lower limb cold exposure induces pain and prolonged small fiber dysfunction in
Fabry patients.
AB - In Fabry disease, an X-linked alpha-galactosidase A deficiency, painful crises
and limb paresthesias are possibly linked to thermal exposure. Small nerve fiber
function has not yet been tested after cold challenge. In two Fabry patients (15
and 17 years old), their heterozygote mother, their healthy sister, and eight
controls, we determined warm and cold perception thresholds at the dorsal foot
and the lower medial calf (method of limits, Somedic-Thermotest), before and 1,
5, 10 and 15 min after 30 s immersion of one leg into 5 degrees C water.
Discomfort was rated from 0 to 10. At baseline, thermal thresholds of all
participants were normal. In contrast to controls, the patients tolerated 30 s
cold stimulation only with interruptions. The mother aborted stimulation after 6
s because of pain. The patients and their mother reported intense burning pain
and numbness during and after stimulation. After cold exposure, thermal sensation
was highly abnormal for 20 min in one and 80 min in the other brother. In
controls, thermal thresholds were somewhat elevated after stimulation but
normalized within 10.0+/-4.6 min. Discomfort during cold exposure was rated 8-10
by the patients and their mother, but 3-5 by the healthy persons. We assume that
glycolipid accumulation in cutaneous and vasa nervorum vessels as well as small
nerve axons accounts for skin and small fiber malperfusion during cold induced
vasoconstriction. Transitory ischemia initiated burning pain and prolonged small
fiber dysfunction.
PMID- 10666543
TI - The reliability and validity of the COMFORT scale as a postoperative pain
instrument in 0 to 3-year-old infants.
AB - The aim of this study was to test the reliability and validity of the COMFORT
scale as a postoperative pain instrument for children aged 0-3 years. Subjects
were 158 neonates and toddlers after major abdominal or thoracic surgery. Trained
nurses rated the children's pain at 3, 6 and 9 h postoperative on the Pediatric
Surgical Intensive Care Unit using the COMFORT and a VAS for pain. Interrater
reliability of the COMFORT items proved to be good (Kappa 0.63-0.93) for all
items with the exception of the item 'Respiratory response', which was moderate
(Kappa 0.54). LISREL analyses showed that the structure of the COMFORT data was
best represented by three latent variables: COMFORT 'behaviour' with loadings
from the behavioural items (Alertness, Calmness, Respiratory response/Crying,
Physical movement, Muscle tone and Facial tension) and separate latent variables
for 'Heart rate baseline' (HR) and 'Mean arterial blood pressure baseline' (MAP).
Factor loadings of the items were invariant across time, indicating stability of
the structure. The latent variables COMFORT 'behaviour' and VAS pain were highly
interrelated indicating congruent validity. Stability of COMFORT 'behaviour' and
VAS pain was moderate which might be due to varying painful episodes in this
sample. HR and MAP, although stable across time, were weakly related to VAS pain
and COMFORT 'behaviour'. These findings support the use of the COMFORT
'behaviour' scale to assess postoperative pain in neonates and infants.
PMID- 10666544
TI - The prevalences of cytochrome c oxidase negative and superpositive fibres and
ragged-red fibres in the trapezius muscle of female cleaners with and without
myalgia and of female healthy controls.
AB - The association of cytochrome c oxidase negative fibres (COX-negative) and ragged
red fibres (RR-fibres) with work related trapezius myalgia has been proposed.
Hitherto studies have been small or without control groups. The aim of the
present study was to investigate the prevalences of RR-fibres and COX-negative
fibres in female cleaners with (n=25) and without (n=23) trapezius myalgia and in
clinically healthy female teachers (n=21). The cleaners did mainly floor cleaning
requiring monotonous loading on the trapezius muscle. A questionnaire covering
background data and aspects of pain (prevalence, duration, intensity and
influence on daily living) was answered. Biopsies were obtained from the
trapezius muscle by an open surgical technique. The three groups did not differ
in prevalence of COX-negative or COX-superpositive (i.e. type-I fibres with
extremely strong brownish reaction in both the COX and SDH/COX stainings) fibres.
The prevalence of COX-negative fibres was age dependent. Two subgroups of RR
fibres were present when stained for COX; COX-negative (73%) and COX
superpositive (26%) fibres. Forty-two percent of the COX-negative fibres were RR
fibres and 79% of the COX-superpositive were RR-fibres. A significantly (P=0.002)
higher proportion of the COX-superpositive fibres in the cleaners were RR-fibres
compared to the teachers. Multivariate regression analysis revealed that age,
occupation as cleaner and a tender point in the trapezius were significantly
associated with increased prevalences of RR-fibres; a cleaner with a tender point
had a 4.35 higher prevalence of RR-fibres compared to a teacher without a tender
point. No correlations between other pain related variables and prevalence of RR
fibres were noted. In conclusion, RR-fibres but not COX-negative or COX
superpositive fibres were correlated with cleaning work tasks and with a tender
point in the trapezius.
PMID- 10666545
TI - Simultaneous depletion of neurokinin A, substance P and calcitonin gene-related
peptide from the caudal trigeminal nucleus of the rat during electrical
stimulation of the trigeminal ganglion.
AB - The central terminals of the primary sensory trigeminal ganglion (TG) neurons
projecting into the caudal trigeminal nucleus (CTN) of the rat exhibit neurokinin
A (NKA)-, substance P (SP)-, and calcitonin gene-related peptide (CGRP)
immunoreactivities (IRs). We stimulated the TG in the rat to induce some of the
alterations which might occur during migraine (neurogenic inflammation). Under a
stereotaxic apparatus and by means of a bipolar electrode, one-side TG of the
animals were electrically stimulated (7.5 Hz, 5 ms, 0.8-1. 4 mA) with square
pulses for 5 min. Then, using immunohistochemical methods, the lower medulla of
each rat was studied for NKA-, SP- and CGRP-IRs. Light microscopic examination of
brain-stem sequencial sections revealed a simultaneous decrease in the
immunoreactivities of all neuropeptides (NKA, SP and CGRP) in the CTN ipsilateral
to TG stimulation in comparison with the other (not stimulated) side CTN. It is
suggested that this decrease in immunoreactivity would be due to the co-release
of neuropeptides following noxious stimuli and that NKA, SP and CGRP might
therefore act as co-transmitters or co-modulators at the first central synapses
of the trigeminal sensory pathway.
PMID- 10666546
TI - Functional interplay between gelatinases and hyperalgesia in endotoxin-induced
localized inflammatory pain.
AB - The role of ECM-degrading proteinases in normal developmental processes and in
pathological conditions is extensively studied. However, few reports describe the
role ECM-degrading proteinases play in modulating hyperalgesia. The goal of this
study is to describe the regulation of gelatinases during endotoxin mediated
local inflammation, induced by intra plantar endotoxin (ET; 1.25 microg/50
microl) injection in Balb/c mice, and to correlate that with hyperalgesia. ET
injections induced hyperalgesia, as determined by hot plate and paw pressure
tests, which peaked by 24 h and recovered by 48 h post-injection. Contralateral
paw of ET injected mice and saline injected paws in control mice elicited no
hyperalgesia. Zymography showed that ET and saline injected paws elicited
increased gelatinase activity by 9 h after injection. However, only the former
maintained high levels of expression of a 90 kD gelatinase up to at least 96 h
post ET injection, while in the latter gelatinase expression was down regulated
by 24 h. Interestingly, the 90-kD gelatinase was upregulated in the contralateral
paw of the ET-injected mice beyond 48 h post injection. Saline injection in that
paw, during a time when gelatinases are upregulated, induced hyperalgesia.
Intraperitoneal injection of either ZnCl(2) (100 microM), thymulin (5 microg/100
microl), or morphine (2 mg/kg/100 microl) reversed the ET-induced hyperalgesia
and suppressed gelatinase activity. Furthermore, intraperitoneal injection of
MPI, an ECM-degrading proteinase inhibitor, reversed ET induced hyperalgesia.
Taken together, the above suggests that a functional interplay exists between
gelatinase upregulation triggered by ET injections and hyperalgesia. The exact
mechanism underlying such correlation remains to be determined.
PMID- 10666547
TI - Intramuscular and intradermal injection of capsaicin: a comparison of local and
referred pain.
AB - The present study compared capsaicin-induced muscle and skin pain in humans.
Twelve healthy subjects received, in a randomised, balanced order, 3
intramuscular (i.m.) injections into the brachioradial muscle: capsaicin 100
microg/1 ml, capsaicin 100 microg/20 microl or 1 ml solvent (Tween 80), and one
intradermal injection (i.d.): capsaicin 100 microg/20 microl. Local and referred
pain intensities and areas were assessed from 0 to 60 min after injection.
Intradermal capsaicin produced more intense local pain than i.m. capsaicin in the
first min (skin: 68+/-6, muscle: 51+/-6 mm VASxmin, P<0.05). In contrast, the
local pain offset was later (muscle: 38+/-5, skin: 23+/-5 min, P<0.05) and
referred pain was more frequent (muscle: 9/12, skin: 1/12 subjects, P<0.01)
following i.m. capsaicin compared with i.d. capsaicin. Capsaicin (1 ml) produced
significantly more pain than 20 microl i.m. (pain in the first min: 1 ml: 71+/-6,
20 microl: 51+/-6 VASxmin, P<0.05, offset: 1 ml: 50+/-4, 20 microl: 38+/-5 min,
P<0.05). The different local and referred pain following identical noxious
stimulation of muscle and skin indicates that the neurophysiological mechanisms
underlying skin and muscle pain differs. The model with identical noxious
stimulation of muscle and skin may be suitable for the study of differences in
deep and superficial pain as seen in the clinic.
PMID- 10666548
TI - Density of sympathetic axons in sural nerve biopsies of neuropathy patients is
related to painfulness.
AB - In this study, differences of unmyelinated nerve fiber density in sural nerve
biopsy material from patients suffering from neuropathies of unknown origin with
(n=14) or without pain (n=13) were analyzed. Immunocytochemistry was applied to
differentiate afferent sensory and efferent sympathetic nerve fibers. All
patients were evaluated for deficits of small fiber function with thermotesting,
quantitative sudomotor-axon reflex-testing and testing of painfulness of
mechanical stimuli before performing the biopsy. No difference was found between
patients with and without pain concerning clinical deficits or results in any of
the neurophysiological examinations. There were also no histopathological
differences concerning the density of afferent C-fibers. However, absolute and
relative density of efferent sympathetic nerve fibers was significantly higher in
patients with painful neuropathy (P<0.001), although none of the patients
demonstrated clinical sympathetic abnormalities. We conclude that an imbalance
between afferent and sympathetic nerve fiber density in the periphery may
contribute to neuropathic pain even in those patients without obvious clinical
autonomic disturbances.
PMID- 10666549
TI - Co-administration of sub-antinociceptive doses of oxycodone and morphine produces
marked antinociceptive synergy with reduced CNS side-effects in rats.
AB - Oxycodone and morphine are structurally related, strong opioid analgesics,
commonly used to treat moderate to severe pain in humans. Although it is well
established that morphine is a mu-opioid agonist, this is not the case for
oxycodone. Instead, our recent studies have shown that oxycodone appears to be a
kappa-opioid agonist (Ross and Smith, 1997). In the current study, we now show
that co-administration of sub-antinociceptive doses of oxycodone (putative kappa
opioid agonist) with morphine (mu-opioid agonist) to rats by both the
intracerebroventricular and by systemic routes (intraperitoneal and
subcutaneous), results in markedly increased (synergistic) levels of
antinociception. Behaviourally, rats co-administered sub-antinociceptive doses of
oxycodone and morphine were similar to control rats dosed with saline, whereas
rats that received equi-potent doses of either opioid alone, were markedly
sedated. These results suggest that co-administration of sub-analgesic doses of
oxycodone and morphine to patients may provide excellent pain relief with a
reduction in opioid-related CNS side-effects. Controlled clinical trials in
appropriate patient populations are required to evaluate this possibility.(1)
PMID- 10666550
TI - Bilateral hand oedema related to acupuncture.
AB - We report the case of bilateral hand swelling following acupuncture therapy for
chronic low back pain. Despite thorough history, examination and laboratory
testing no systemic cause for the swelling could be elicited. This case
highlights the incomplete knowledge of acupuncture mechanisms and that limited
acupuncture therapy can have significant adverse effects.
PMID- 10666551
TI - Motor cortex stimulation for chronic neuropathic pain: a preliminary study of 10
cases.
AB - There is growing evidence to support the use of motor cortex stimulation (MCS) in
the management of patients with chronic neuropathic pain. A prospective audit of
ten patients using a modified staged technique for motor cortex implantation
provides further evidence for the analgesic effectiveness of this technique. Ten
patients suffering from phantom limb pain (n=3), post stroke pain (n=5), post
traumatic neuralgia secondary to gunshot injury to the brain stem (n=1) and
brachyalgia secondary to neuro-fibromatosis (n=150% pain relief) and long-term
benefit in 4/5 of patients who initially responded to intermittent cortical
stimulation (longest follow up 31 months after implantation). Of those patients
who benefited two had post stroke pain, two phantom limb pain and one post
traumatic neuralgia. We conclude that motor cortex stimulation is an effective
analgesic intervention in some patients with chronic neuropathic pain, but it is
difficult if not impossible to predict those patients who may respond to
treatment prior to implantation. Randomised controlled trials are now urgently
needed to test the effectiveness of motor cortex stimulation under double-blind
conditions.
PMID- 10666552
TI - Replication and further studies of neural mechanisms of spatial mnemonic
processing in humans.
AB - Changes in neuronal firing rates during periods of time when subjects are
required to remember information (retention delays) have been reported in non
human primates. In humans, tests for such functional changes using hemodynamic
markers of neural activity have typically relied on cognitive subtraction.
However, the temporal resolution of fMRI allows a more direct test than that
afforded by cognitive subtraction of the idea that certain brain regions may
increase their neural activity during retention delays in humans. Using a method
that exploits this temporal resolution, increased functional activity
attributable to a retention delay for spatial information in regions proximate
to/within the right frontal eye field and the right superior parietal lobule were
detected (in four out of four and three out of four subjects, respectively; this
is an internal replication of the results of [E. Zarahn, G.K. Aguirre, M.
D'Esposito, Temporal isolation of the neural correlates of spatial mnemonic
processing with fMRI, Cognit. Brain Res., 7 (1999) 255-268. ]). Second, a model
in which ventral and not dorsal prefrontal cortex in humans is involved in simply
maintaining spatial information was tested. The results disputed this model as
increases in fMRI signal attributable to the retention delay were detected more
frequently in dorsal than ventral prefrontal cortex. Third, a model which posited
that the intensity of neural activity is causally related to the accuracy of
spatial mnemonic representation was tested by comparing retention delay signal
between correct and incorrect trials. The results did not support this model in
any of the regions tested.
PMID- 10666553
TI - Neurocognition of auditory sentence comprehension: event related fMRI reveals
sensitivity to syntactic violations and task demands.
AB - The present study investigates the sensitivity of distinct brain regions to the
syntactic processing of running speech. Experimental conditions varied the
grammaticality of sentence types (correct vs. incorrect). Moreover, two different
groups of subjects listened to the same sentence material, but followed two
different task instructions. All participants were asked to listen to the
auditory stimuli and to perform in a grammaticality judgment-task, whereas only
half of the subjects were instructed to additionally repair incorrect sentences
covertly. Significantly increased brain responses occurred in several left
temporal areas as a function of sentences' grammaticality, particularly, in the
'pure' judgment-group. Spatial extent as well as the strength of focal brain
activation changed as a function of grammaticality and task demand. A generally
enhanced pattern of local blood supply to the right peri-sylvian cortex could be
observed when individuals additionally realized the repair-task. In particular,
the right inferior frontal gyrus (pars opercularis and pars triangularis) and the
right temporal transverse gyrus (Heschl's gyrus) were more strongly affected by
the repair-task demand. In contrast, an anterior portion of the superior temporal
gyrus (planum polare) displayed increased activation bilaterally. Although left
hemisphere activation varied clearly as a function of a sentence's
grammaticality, the present findings demonstrate an involvement of the right peri
sylvian cortex, in particular, when task demands explicitly require an on-line
repair. The results as a whole suggest a reconsideration of the notion that
auditory language comprehension is restricted to the left hemisphere. The
underlying mechanisms and the respective roles of both the left and the right
hemisphere during speech processing are discussed.
PMID- 10666554
TI - Learning of spatial and temporal patterns in sequential hand movements.
AB - Speed and accuracy in performing a complex movement sequence improve with
practice. To examine how the temporal and spatial patterns of movement sequence
are learned, the sequence of target locations and the consistency in the timing
of target presentation were manipulated independently while subjects produced a
series of visually guided hand movements. When the sequence of target locations
and the timing of target presentation followed a consistent pattern, performance
for a particular movement sequence improved with practice for both temporal and
spatial movement parameters. However, when the same temporal and spatial patterns
were recombined with a phase shift, there was a small but consistent deficit in
performance. These results suggest that whereas spatial and temporal patterns in
a learned movement sequence can be recombined flexibly, optimal performance is
obtained for a specific spatio-temporal pattern of movement sequence. Whereas
subjects were largely aware of the spatial and temporal patterns, they were
unaware of the phase-shift, suggesting that learning of a specific spatio
temporal pattern was implicit.
PMID- 10666555
TI - False recognition in a verbal memory task: an event-related potential study.
AB - Brain potentials were recorded from 15 healthy young subjects during the
performance of a word recognition task. During the study phase, subjects had to
intentionally memorise a series of words. These words were presented again
together with the same number of new words in a following test phase where the
instruction was to discriminate between repeated words and new words. We compared
event-related potentials (ERPs) evoked by correctly identified repeated words
(hits) and ERPs evoked by incorrectly classified new words (false alarms).
Although both types of words were thought to be repeated the ERPs indicated
differences between these two conditions starting at about 450 ms after the
stimulus onset. These differences were mostly pronounced over frontal scalp
locations but occurred also over parietal scalp locations (false alarms produced
significantly more negative going ERPs than hits). We interpret that frontal and
parietal brain areas show greater activation during false recognition because of
a more intensive search for item representations.
PMID- 10666556
TI - Interhemispheric interaction in semantic categorization of pictures.
AB - Interhemispheric processing may either increase or decrease the processing power
of the brain. The two experiments presented here examined in normal subjects
whether hemispheric interaction would be useful or not in semantic categorization
of pictures. It was tested whether the advantages of dividing the processing
between the hemispheres would increase when the experimental task was kept
constant but the computational demands of the stimuli was increased. The critical
stimuli were either identical (two copies of the same picture) or semantically
related pictures (e.g., apple-banana). The stimuli were presented either
unilaterally to the same hemisphere or bilaterally to the opposite hemispheres.
The results from the two experiments showed a bilateral advantage in
categorization of the semantically related pictures but not in categorization of
the less demanding identical pictures. The results support the hypothesis that
the cognitive capacity of the brain can be increased by dividing the processing
of relatively demanding stimuli between the hemispheres.
PMID- 10666557
TI - Primary task demands modulate P3a amplitude.
AB - Auditory event-related brain potentials (ERPs) were recorded from 10 subjects in
two different conditions: (1) subjects were required to reorder five visually
presented letters in order to form a word and provide a verbal response (task
condition); (2) subjects were presented with a control stimulus with the same
physical characteristics as the experimental stimulus, but containing just one
type of letter (i.e., AAAAA). Subjects had to verbally respond to such stimuli by
saying "A" (control condition). Tones of 1000 Hz (standard) and 1050 Hz (deviant)
were also presented to the subjects in a 85%-15% probability paradigm 2 s before,
during and 8 s after the presentation of the visual stimuli. Recordings were
obtained from Fpz, Fz, Cz and Pz vs. linked ears. Auditory ERPs to the auditory
stimuli after the presentation of the visual letter string and during the
performance of the task were averaged for the standard and deviant tones in both
conditions. Only correct responses were considered for the averages. The N100 was
affected by stimulus type (standard vs. deviant) but not by condition (task vs.
control); however, larger P3a waves were observed during the control than during
the task condition. No significant differences between conditions were observed
in the mismatch negativity (MMN) latency range. These results suggest that
primary task demands modulate involuntary attention processing.
PMID- 10666558
TI - Dopamine-antagonistic, anticholinergic, and GABAergic effects on declarative and
procedural memory functions.
AB - Declarative and procedural memory functions are related to dissociable
neuroanatomic substrates. In the present study differential effects of
pharmacologically induced changes in dopaminergic, GABAergic, and cholinergic
activity in the brain on declarative (object and face recognition, immediate and
delayed word recall) and procedural memory processes (compensatory tracking) were
investigated. In a double-blind design, either 3 mg of haloperidol, 11 mg of
midazolam, 1 mg of scopolamine, or placebo were administered to 80 healthy
volunteers randomly assigned to one of the four drug conditions. Although all
three drugs produced a detrimental effect on immediate and delayed word recall,
recall performance was substantially more impaired by the benzodiazepine
midazolam than by either haloperidol or scopolamine. While recognition of faces
was affected by neither of the drugs, performance on object recognition was
significantly decreased by midazolam as compared to placebo. Procedural learning
was markedly impaired by all drugs but, again, the observed effect was most
pronounced with midazolam. Additional analyses of measures of subjective
activation, cortical arousal, and psychomotor performance argued against the
assumption that the observed memory-impairing effects were secondary to drug
induced sedation. The overall pattern of results revealed that memory processes
are much more susceptible to changes in GABAergic than in dopaminergic or
cholinergic neurotransmitter activity. Furthermore, the present findings point to
the conclusion that the modulating effects of dopaminergic, GABAergic, and
cholinergic neurotransmitter systems on declarative and procedural memory
functions are less specific than suggested by neuropsychological studies in
patients.
PMID- 10666559
TI - Functional asymmetry of human prefrontal cortex in verbal and non-verbal episodic
memory as revealed by fMRI.
AB - Functional neuroimaging studies have demonstrated preferential involvement of
bilateral prefrontal cortex during episodic memory encoding and retrieval. The
aim of the present study is to address the question whether left prefrontal model
for encoding holds when highly non-verbal material is used, and which region of
the brain is critically related to successful retrieval. To do this, seven normal
subjects were investigated using functional magnetic resonance imaging (fMRI)
during encoding and retrieval of word and checkerboard pattern. Our results
revealed that word encoding activated the left prefrontal cortices and right
cerebellum, whereas pattern encoding activated the bilateral middle frontal
gyrus, superior parietal lobule, premotor area, and occipital visual cortex. Word
specific activation was found in the ventral prefrontal cortices, and pattern
specific activation located in the right dorsal prefrontal cortex. Conjunction
analysis during encoding of word and pattern showed that activity in the left
dorsal prefrontal cortex and the right cerebellum might relate to common neural
network for encoding regardless of the type of material. Finally, the present
study demonstrates strong association between the left ventral prefrontal cortex
and retrieval success for word. The evidence, that both encoding and retrieval of
words activated the left ventral prefrontal cortex, indicates that this area is
involved in active and strategic operation of the mnemonic representation. A lack
of the right prefrontal activation during retrieval was interpreted as that
activity in this region might relate to retrieval effort rather than success.
PMID- 10666560
TI - Hemispheric asymmetry for selective attention.
AB - A letter-identification task, previously demonstrated to show activation of the
pulvinar nucleus of the thalamus with fluodeoxyglucose position emission
tomography, was administered to 20 normal volunteers. The letter to be detected
could appear alone as a big stimulus or as a small one stimulus surrounded by
flanking letters. To test for a hemispheric specialization for filtering
processes, the stimuli were displayed horizontally, either in the left or in the
right hemifield, or vertically, either above or below the fixation point. In
addition, to study the effect of cognitive processes on selective attention
resources, we varied the feedback conditions, by delivering or not delivering a
blue flash in cases of misses or mistakes. The results show a significant
interaction between the type of stimulus (alone or surrounded by flankers) and
the hemifield of presentation (left or right) only in the condition where the
subjects were presented stimuli horizontally without any feedback. In this
condition, reaction times (RTs) were shorter in the left hemifield than in the
right hemifield for single stimuli, whereas for stimuli surrounded by flankers,
the opposite pattern was observed, that is, shorter RT in the right hemifield
than in the left one. The present findings suggest a hemispheric specialization
for selective attention, in particular at the subcortical level.
PMID- 10666561
TI - Mental rotation for spatial environment recognition.
AB - We investigated the importance of retinal and body inclination in the recognition
of spatial environment. The paradigm involved the recognition, in body upright
and tilted conditions, of tilted images -intervals of 15 degrees from 0 degrees
to 90 degrees leftward and rightward respective to head coordinates - of known
spatial layouts encountered while walking in Paris. The analysis of reaction
times was consistent with the subjects mentally rotating the spatial layout so
that the environment was subjectively vertical before making their decisions. In
contrast, when the body was roll-tilted (33 degrees ), overall reaction time was
not affected; however, reaction time and spatial layout tilt with respect to the
head were correlated when the body was tilted but not when upright. Both results
indicate that gravity was slightly important in performing the task.
PMID- 10666562
TI - Prefrontal cortex activation in task switching: an event-related fMRI study.
AB - When a switch between two tasks has to be carried out, performance is slower than
in trials where the same task is performed repeatedly. This finding has been
attributed to time-consuming control processes required for task switching.
Previous results of other paradigms investigating cognitive control processes
suggested that prefrontal cortex is involved in executive control. We used event
related fMRI to investigate prefrontal cortex involvement in task switching.
Regions in the lateral prefrontal and premotor cortex bilaterally, the anterior
insula bilaterally, the left intraparietal sulcus, the SMA/pre-SMA region and the
cuneus/precuneus were activated by the task repetition condition and showed
additional activation in the task switch condition. This confirmed the hypothesis
that lateral prefrontal cortex is involved in task switching. However, the
results also showed that this region is neither the only region involved in task
switching nor a region specifically involved in task switching.
PMID- 10666563
TI - Different cortical activity in reading of Kanji words, Kana words and Kana
nonwords.
AB - We report a positron emission tomography study on reading of Japanese Kanji
(morphograms) words, Kana (phonograms) words and Kana nonwords using statistical
parametric mapping. Activity was more pronounced in the lateral fusiform gyrus
(Area 37) in Kanji, in contrast to the greater activation in the middle and
inferior occipital gyri (Areas 18 and 19) and the deep perisylvian temporo
parietal area (Areas 40/22 and 22/21) in Kana, suggesting that Kanji and Kana are
processed differently.
PMID- 10666564
TI - Early and late components of visual categorization: an event-related potential
study.
AB - We examined the characteristics of early and late components of event-related
potentials (ERPs) accompanying the visual categorization of natural scenes. In
the first experiment, ERPs were recorded in an animal-non-animal categorization
task (CT), whereas the second experiment included a spatial frequency
discrimination task (DT). In the CT, there were more negative potentials for non
animals in the time windows of 150-250 ms (N1) and 350-500 ms (N2), and a more
positive potential for animals in the time window of 250-350 ms (P2). In the DT,
spatial frequency gratings evoked only a short-duration difference N1 at the
frontal sites. Our results suggest that N1 may be related to higher-level
categorization processes.
PMID- 10666565
TI - Activity of the phosphatidylcholine biosynthetic pathway modulates the
distribution of fatty acids into glycerolipids in proliferating cells.
AB - PtdCho accumulation is a periodic, S phase-specific event that is modulated in
part by cell cycle-dependent fluctuations in CTP:phosphocholine
cytidylyltransferase (CCT) activity. A supply of fatty acids is essential to
generate the diacylglycerol (DG) precursors for phosphatidylcholine (PtdCho)
biosynthesis but it is not known whether the DG supply is also coupled to the
cell cycle. Although the rate of fatty acid synthesis in a macrophage cell line
was dramatically stimulated in response to the growth factor, CSF-1, it was not
regulated by the cell cycle. Increased fatty acid synthesis correlated with
elevated acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) steady-state
mRNA levels. Cellular fatty acid synthesis was essential for membrane PL
synthesis. Cerulenin inhibition of endogenous fatty acid synthesis also inhibited
PtdCho synthesis, which was not relieved by exogenous fatty acids. Inhibition of
CCT activity by the addition of lysophosphatidylcholine (lysoPtdCho) or
temperature-shift of a conditionally defective CCT diverted newly synthesized DG
to the TG pool where it accumulated. Enforced expression of CCT stimulated PtdCho
biosynthesis and reduced TG synthesis. Thus, the cellular DG supply did not
regulate PtdCho biosynthesis and CCT activity governs the partitioning of DG into
either the PL or TG pools, thereby controlling both PtdCho and TG biosynthesis.
PMID- 10666566
TI - The major low molecular weight apolipoprotein from normal and hyperlipidemia
atherosclerosis-prone (LAP) Japanese quail.
AB - The low molecular weight (LMW) apolipoprotein of apo C plays an important role in
the metabolism of triglyceride-rich lipoproteins. This study aimed at a
characterization of the major LMW apolipoproteins from normal quail strain, and
also from LAP (hyperlipidemia atherosclerosis-prone) strain to identify its
genetic disorder. The major LMW apoprotein cDNA clone from normal quail comprised
of approximately 500 bp, and encoded polypeptide of 78 amino acid residues
containing 57 amino acids as a mature apolipoprotein. Although the quail LMW
apoprotein showed a low homology to either apo C-I, C-II, or C-III of other
animals, it retained a well-developed amphipathic alpha-helix structure. There
was no difference in the deduced primary structure of the quail LMW apoprotein
between LAP and normal strain. An analysis of the mRNA expression showed that the
quail LMW apoprotein was only expressed in the liver of both LAP and normal
Japanese quail. No difference was noted in the hepatic expression of the quail
LMW apoprotein mRNA between normal and LAP strains with neither normal nor
atherogenic dietary conditions. The structure and expression of the major LMW
apoprotein thus had no relevance to higher susceptibility of LAP strain to the
experimental atherosclerosis.
PMID- 10666567
TI - Purification and regiospecificity of multiple enzyme activities of phospholipase
A(1) from bonito muscle.
AB - Phospholipase A(1) (PLA(1)), which catalyzes the hydrolysis of the sn-1 ester
bond of diacyl phospholipids, was purified from 100,000 x g supernatant of bonito
muscle to homogeneity by ammonium-sulfate precipitation and four consecutive
column chromatographies (DEAE anion-exchange, ether-Toyopeal, hydroxylapatite and
Toyopeal HW 50S columns). The final preparation showed a single band above the 67
kDa molecular marker on SDS-PAGE, and the molecular mass was determined to be
71.5 kDa by matrix-assisted laser desorption/ionization time-of-flight mass
spectrometry using bovine serum albumin as a standard for calibration. The N
terminal 8 amino residues were determined to be Ala-Pro-Ala-Glu-Lys-Val-Lys-Try.
Regiospecificity of multiple enzyme activities of the PLA(1) was examined using
positionally defined synthetic phosphatidylcholine (PC) and
lysophosphatidylcholines (LPC). An acyl ester bond at the sn-1 position of PC was
exclusively hydrolyzed by phospholipase activity, and 1-acyl LPC was cleaved to
fatty acid and glycerophosphocholine by lysophospholipase (LPL) activity.
However, the positional isomer, 2-acyl LPC was a poor substrate for LPL activity.
PC/transacylation activity was also observed when excess 2-acyl LPC was supplied
in the reaction mixture, and fatty acid at the sn-1 position of donor PC was
transferred to the sn-1 position of acceptor LPC. These results demonstrate that
the multiple enzyme activities of PLA(1), this is lysophospholipase, transacylase
as well as phospholipase, have a strict regiospecificity at the sn-1 position of
substrates.
PMID- 10666568
TI - Phosphocholine and phosphoethanolamine during chick embryo myogenesis: a (31)P
NMR study.
AB - Elevated contents of phosphoethanolamine (Etn-P) and/or phosphocholine (Cho-P), a
common feature of most tumours with respect to normal counterparts, may also
occur in non-cancerous proliferating tissues. The significance of these
alterations in relation to cell proliferation, differentiation and maturation is
scarcely understood. In this work, the Cho-P and Etn-P pools were measured by
(31)P-NMR in extracts of chick embryo pectoral muscle at different days of
development. The average concentration of these metabolites exhibited the highest
values (respectively, 1.5 and 3.0 micromol/mg DNA) on days 9-11 and decreased at
later stages of myogenesis. While, however, Cho-P maintained substantial levels
(above 1.0 micromol/mg DNA) also during myotube formation (days 11-18) and
stepwise decreased (to about 0.5 micromol/mg DNA) upon fibres' maturation, Etn-P
gradually decreased between day 11 and hatching time (down to about 0.2
micromol/mg DNA). These results demonstrate that significant changes may occur in
the steady-state pools of these metabolites during normal in vivo cellular
development and differentiation, and are consistent with: (a) high rates of
phospholipid biosynthesis reported in the literature for proliferating myoblasts;
(b) sustained phosphatidylcholine synthesis maintained also during myoblast
fusion; and (c) decreased requirement of phospholipid synthesis in the last phase
of in ovo myofibre maturation.
PMID- 10666569
TI - The contribution of newly synthesized cholesterol to bile salt synthesis in rats
quantified by mass isotopomer distribution analysis.
AB - A new stable isotope procedure has been developed and validated in rats, applying
[1-(13)C]acetate infusion to quantify the production of bile salts from de novo
synthesized cholesterol making use of the mass isotopomer distribution analysis
(MIDA) principle. Ions (m/z) 458-461, 370-373 and 285-288 were monitored by GC/MS
(EI-mode) for the methyl trimethylsilylether derivatives of cholate,
chenodeoxycholate and beta-muricholate, respectively. Rats with intact
exteriorized enterohepatic circulation and rats with chronic bile diversion were
infused with [1-(13)C]acetate for up to 14 h. After 10 h of infusion the
enterohepatic circulation of the intact group was interrupted to deplete the
existing bile salt pool (acute bile diversion). The fractions of biliary
cholesterol and individual bile salts derived from newly synthesized cholesterol
were determined by MIDA at t=14 h. In rats with acute bile diversion, these
fractions were 20, 25, 27 and 23% for biliary cholesterol, cholate,
chenodeoxycholate and beta-muricholate, respectively. After bile diversion for 8
days to induce hepatic cholesterol and bile salt synthesis, these fractions
increased significantly to 32, 47, 41 and 47%, respectively. Calculated
enrichments of the acetyl-CoA precursor pools were similar for all bile salts and
biliary cholesterol within the two rat groups. However, chronic enterohepatic
interruption decreased the acetyl-CoA pool size almost two-fold. We conclude that
MIDA is a validated new stable isotope technique for studying the synthetic
pathway from acetyl-CoA to bile salts. This technique provides an important new
tool for studying bile salt metabolism in humans using stable isotopes.
PMID- 10666570
TI - Intestinal fatty acid binding protein may favor differential apical fatty acid
binding in the intestine.
AB - The intestinal mucosa metabolizes fatty acids differently when presented to the
lumenal or basolateral membrane. Expression of both liver and intestinal fatty
acid binding proteins (L- and I-FABPs) uniquely in the enterocyte offers a
possible explanation of this phenomenon. An organ explant system was used to
analyze the relative binding of fatty acids to each protein. More fatty acid was
bound to L-FABP than to I-FABPs (28% vs. 6% of cytosolic radioactivity), no
matter on which side the fatty acid was added. However, a 2-3-fold increase in
fatty acid binding to the intestinal paralog was noted after apical addition of
palmitic or oleic acid in mucosa from chow fed rats. When oleic acid was added
apically, a 1.4-fold increase in binding to I-FABP was observed in mucosa derived
from chronically fat fed rats, consistent with the previously observed 50%
increase in the content of that protein. Immunocytochemical localization of both
FABPs in vivo demonstrated an apical cytoplasmic localization in the fasting
state, and redistribution to the entire cytoplasm after fat feeding. These data
are consistent with the hypothesis that I-FABP may contribute to the metabolic
compartmentalization of apically presented fatty acids in the intestine.
PMID- 10666571
TI - Use of differentially substituted selenomethionine proteins in X-ray structure
determination.
AB - Using heavily methionine-substituted T4 lysozyme as an example, it is shown how
the addition or deletion of a small number of methionines can simplify the
location of selenium sites for use in MAD phasing. By comparing the X-ray data
for a large number of singly substituted lysozymes, it is shown that the optimal
amino acid to be substituted by methionine is leucine, followed, in order of
preference, by phenylalanine, isoleucine and valine. The identification of
leucine as the first choice agrees with the ranking suggested by the Dayhoff
mutation probability, i.e. by the frequency of amino-acid substitutions in the
sequences of related proteins. The ranking of the second and subsequent choices,
however, differ significantly.
PMID- 10666572
TI - Structure of taq DNA polymerase shows a new orientation for the structure
specific nuclease domain.
AB - Thermus aquaticus DNA polymerase I consists of the polymerase, the structure
specific nuclease and the vestigial editing nuclease domains. Three-dimensional
structures of the native enzyme and its complex with DNA have already been
reported. The structure of a complex with an inhibitory antibody has also been
determined. The structure of the native enzyme in a different crystal form
determined at 2.6 A is reported here. Optimized anomalous diffraction
measurements made at the holmium L(III) edge were valuable in validating
solutions obtained through molecular replacement. The structure of the polymerase
domain is similar to those reported previously, while the relative orientation of
the structure-specific nuclease domain is significantly different from those of
the native enzyme and the DNA complex; it is, however, identical to that observed
in the structure of the Fab complex. In the structures of the native enzyme and
of the DNA complex reported previously, the active site of the structure-specific
nuclease domain is too far from that of the polymerase domain, making it
difficult to propose a structural model for the in vivo primer-excision and nick
translation activities of the enzyme. In the present structure, the two active
sites are considerably closer. Taken together, the reported structure of the
native enzyme, that of the Fab complex and the present structure imply that the
different orientation of the structure-specific nuclease domain is probably a
consequence of intrinsically high relative mobility between these two domains in
this enzyme.
PMID- 10666573
TI - Three-dimensional structure of the Gly121Tyr dimeric form of ornithine
decarboxylase from Lactobacillus 30a.
AB - Ornithine decarboxylases catalyze the conversion of ornithine to putrescine at
the beginning of the polyamine pathway. Ornithine decarboxylase (ODC) from
Lactobacillus 30a is a 990612 Da dodecamer composed of six homodimers. A single
point mutation (Gly121Tyr) was found to prevent association of dimers into
dodecamers. The dimeric protein has been crystallized at pH 7.0 in the presence
of guanosine triphosphate (GTP). Crystals belong to space group P3(2)21, with
unit-cell parameters a = 111.8, c = 135.9 A and one monomer in the asymmetric
unit. The structure was determined by molecular replacement and refined using
simulated annealing to R = 0.211 at 2. 7 A resolution. The GTP-binding site was
analyzed in detail. The protein exhibits a novel binding mode for GTP which is
different from that seen in most G-proteins or GTPases. Central to this binding
scheme appear to be three lysines, Lys190, Lys374 and Lys382, which form salt
bridges with the three phosphates, and Thr191, which hydrogen bonds with the
guanine base. Furthermore, the structure suggests that there is some flexibility
in the wing domain, which can change its orientation as the protein adapts to its
environment. The active site is similar to that of the native enzyme, consistent
with the observation that the enzyme activity does not depend on its dodecameric
state.
PMID- 10666574
TI - Structure of agkistrodotoxin in an orthorhombic crystal form with six molecules
per asymmetric unit.
AB - The structure of agkistrodotoxin crystallized under basic conditions has been
determined at 2.8 A resolution by the molecular-replacement technique and refined
to a crystallographic R factor of 0.194 and a free R factor of 0.260 with good
stereochemistry. The molecular packing in the crystal differs from other PLA(2)s.
The six molecules in the asymmetric unit form three dimers linked by Ca(2+) ions
in a near-perfect six-ligand octahedral coordinating system. Extensive
intermolecular hydrophobic interactions occur at the interfacial recognition site
of each neurotoxin molecule, which provides an insight into phospholipase A(2)
membrane interactions. This hydrophobic interaction-induced molecular association
along the interfacial recognition site suggests a self-protection mechanism of
agkistrodotoxin.
PMID- 10666575
TI - Comparing anisotropic displacement parameters in protein structures.
AB - The increasingly widespread use of synchrotron-radiation sources and cryo
preparation of samples in macromolecular crystallography has led to a dramatic
increase in the number of macromolecular structures determined at atomic or near
atomic resolution. This permits expansion of the structural model to include
anisotropic displacement parameters U(ij) for individual atoms. In order to
explore the physical significance of these parameters in protein structures, it
is useful to be able to compare quantitatively the electron-density distribution
described by the refined U(ij) values associated with corresponding
crystallographically independent atoms. This paper presents the derivation of an
easily calculated correlation coefficient in real space between two atoms modeled
with anisotropic displacement parameters. This measure is used to investigate the
degree of similarity between chemically equivalent but crystallographically
independent atoms in the set of protein structural models currently available
from the Protein Data Bank.
PMID- 10666576
TI - Three-centre C-H---O hydrogen bonds in the DNA minor groove: analysis of
oligonucleotide crystal structures.
AB - AA.TT and GA.TC dinucleotide steps in B-DNA-type oligomeric crystal structures
and in protein-bound DNA fragments (solved using data with resolution <2.6 A)
show very small variations in their local dinucleotide geometries. A detailed
analysis of these crystal structures reveals that in AA.TT and GA.TC steps the
electropositive C2-H2 group of adenine is in very close proximity to the keto O
atoms of both the pyrimidine bases in the antiparallel strand of the duplex
structure, suggesting the possibility of intra-base pair as well as cross-strand
inter-base pair C-H---O hydrogen bonds in the DNA minor groove. The C2--H2---O2
hydrogen bonds in the A.T base pairs could be a natural consequence of Watson
Crick pairing. However, the cross-strand interactions between the bases at the 3'
end of the AA.TT and GA.TC steps obviously arise owing to specific local geometry
of these steps, since a majority of the H2---O2 distances in both data sets are
considerably shorter than their values in the uniform fibre model (3.3 A) and
many are even smaller than the sum of the van der Waals radii. The analysis
suggests that in addition to already documented features such as the large
propeller twist of A.T base pairs and the hydration of the minor groove, these C2
H---O2 cross-strand interactions may also play a role in the narrowing of the
minor groove in A-tract regions of DNA and help explain the high structural
rigidity and stability observed for poly(dA).poly(dT).
PMID- 10666577
TI - Human apolipoprotein A-I: structure determination and analysis of unusual
diffraction characteristics.
AB - The crystallization and structure determination of recombinant human
apolipoprotein A-I (apo A-I), the major protein component of high-density
lipoprotein, is described. The fragment crystallized, residues 44-243 of native
apo A-I [apo Delta(1-43)A-I], is very similar to intact native apo A-I in its
ability to bind lipid, to be incorporated into high-density lipoproteins and to
activate lecithin-cholesterol acyl transferase. Apo Delta(1-43)A-I crystallizes
from 1.0-1.4 M sodium citrate pH 6.5-7.5 in space group P2(1)2(1)2(1), with unit
cell parameters a = 97.47, b = 113.87, c = 196.19 A (crystal form I). The
crystals exhibit unusual diffraction intensity spikes and axial extinctions that
are discussed in the context of the 4 A crystal structure. When flash-cooled to
100 K, the crystals diffract synchrotron radiation to 3 A resolution. Radiation
sensitivity and crystal-to-crystal variation have hindered the assembly of a
complete 3 A data set.
PMID- 10666578
TI - X-ray diffraction of helices with arbitrary periodic ligand binding.
AB - The classical formalism for studying diffraction from helical structures extended
to include ligand binding is presented. The diffraction from such a binding
pattern is the convolution of the Fourier transforms of the helix and the one
dimensional binding distribution. It is shown in the present analysis that it is
not necessary to assume that the binding distribution is strictly periodic, as
long as its Fourier transform can be determined. Analysis of the convolution
gives a general expression for the diffracted intensities and the selection rule
for the layer-lines. It shows two groups of layer-lines: one group is the
familiar layer-line set from the original helix, while the other group shows
reciprocal spacings shifted by 1/a from the original helix layer-lines, where a
is the average repeat of the binding distribution. This group of layer-lines is
contributed by the ligand only. By way of examples, calculated diffraction
patterns from muscle actin filaments with bound myosin heads in three different
binding patterns are presented. This approach provides a method for determining
the ligand-binding distribution along helices by an analysis of their X-ray
diffraction patterns.
PMID- 10666579
TI - Expression, purification, crystallization and preliminary X-ray analysis of
Escherichia coli argininosuccinate synthetase.
AB - A recombinant form of Escherichia coli argininosuccinate synthetase with a C
terminal polyhistidine affinity tag has been expressed, purified and subsequently
crystallized using the hanging-drop vapour-diffusion technique. The crystals grow
as large rectangular chunks with unit-cell dimensions a = 79.70, b = 105.84, c =
127.33 A, alpha = beta = gamma = 90 degrees. The crystals exhibit the symmetry of
space group I222 and diffract to a minimum d-spacing of 1.6 A at station X8C of
the National Synchrotron Light Source, Brookhaven National Laboratory. On the
basis of density calculations, one monomer of this homotetrameric protein is
predicted per asymmetric unit (Matthews coefficient V(m) = 2.69 A(3) Da(-1)).
PMID- 10666580
TI - Crystallization and preliminary analysis of bovine adenosine deaminase.
AB - Adenosine deaminase (ADA) from bovine intestine was crystallized with purine
riboside by vapour diffusion using ammonium sulfate as precipitant. The crystals
are tetragonal and have unit-cell parameters a = b = 80.03, c = 141.68 A. They
belong to space group P4(1)2(1)2 or P4(3)2(1)2 and diffract to at least 2.0 A
resolution. The structure is being solved by molecular replacement.
PMID- 10666581
TI - Crystallization and preliminary X-ray analysis of the Escherichia coli UDP-MurNAc
tripeptide D-alanyl-D-alanine-adding enzyme (MurF).
AB - Crystals of the Escherichia coli UDP-MurNAc-tripeptide D-Ala-D-Ala-adding protein
(MurF), which catalyzes the formation of the last metabolite of the bacterial
cell-wall building block, have been grown in hanging-drop vapor-diffusion trials
using PEG 8K as a precipitating agent. The crystals belong to hexagonal space
group P6(1) or P6(5), with unit-cell dimensions a = b = 74, c = 425 A. The
asymmetric unit contains two molecules, with a crystal volume per protein mass
(V(m)) of 3.4 A(3) Da(-1) and a solvent content of about 64% by volume. A native
data set to 2.8 A resolution has been obtained from a frozen crystal using a
synchrotron X-ray source.
PMID- 10666582
TI - Crystallization and preliminary X-ray analysis of birch-pollen allergen Bet v 1
in complex with a murine monoclonal IgG Fab' fragment.
AB - The human type I allergic response is characterized by the presence of allergen
specific serum immunoglobulin E (IgE). Allergen-mediated cross-linking of
receptor-bound IgE on the surface of mast cells and circulating basophils
triggers the release of mediators, resulting in the development of the clinical
symptoms of allergy. In order to study the structural basis of allergen-antibody
interaction, a complex between the major birch-pollen allergen Bet v 1 and a Fab'
fragment isolated from the murine monoclonal Bet v 1 antibody BV16 has been
crystallized. Complex crystals belong to space group P1, with unit-cell
parameters a = 91.65, b = 99.14, c = 108.90 A, alpha = 105.7, beta = 98.32, gamma
= 97.62 degrees, and diffract to 2.9 A resolution when analyzed at 100 K using
synchrotron-generated X--rays.
PMID- 10666583
TI - Ethylammonium nitrate: a protein crystallization reagent.
AB - Ethylammonium nitrate (EAN) is a liquid organic salt that has many potential
applications in protein chemistry. Because this solvent has hydrophobic and ionic
character as well as the ability to hydrogen bond, it is especially well suited
for broad use in protein crystallography. For example, EAN may be used as an
additive, a detergent, a precipitating agent or to deliver ligands into protein
crystals. A discussion of the crystallization of lysozyme using EAN as a
precipitating agent is given here.
PMID- 10666584
TI - Structural studies of the Msx-1 homeodomain-DNA complex I.
AB - Crystals of the Msx-1 homeodomain-DNA complex have been obtained by hanging-drop
vapor diffusion at 293 K in 12% PEG 4000 and 0.1 M sodium acetate pH 4.6. The
homeodomain consists of 60 amino acids and is the DNA-binding domain. The DNA in
the complex was 16 base pairs with the sequence 5'-TGTCACTAATTGAAGG-3',
containing an overhang T at each end. The crystals diffract to 2.15 A (99.8%
completeness) using cryogenic (123 K) conditions. The crystals belong to the
orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 33.66, b =
60.96, c = 83.37 A. The structure will illuminate the details of Msx-1-DNA
binding specificity and clarify its role in transcriptional regulation. Mutations
in Msx-1 cause craniofacial deformities in mice.
PMID- 10666585
TI - Crystallization and preliminary X-ray diffraction studies of Streptococcus
pyogenes plasmid pSM19035-encoded omega transcriptional repressor.
AB - The transcriptional repressor, omega protein, from the Streptococcus pyogenes
broad-host-range plasmid pSM19035 was crystallized at pH 7. 5 and 8.5 by the
vapour-diffusion method using PEG 4000 as precipitant. Two crystal forms were
obtained; the first belongs to the tetragonal space group P4(1)2(1)2 or
P4(3)2(1)2 and the second to the hexagonal space group P6(1) or P6(5). The
crystals are most likely to contain one omega protein in the asymmetric unit,
with V(m) values of 3.2 and 3.5 A(3) Da(-1), respectively. The crystals diffract
X-rays to 2.4 and 2.9 A resolution for the tetragonal and hexagonal systems,
respectively.
PMID- 10666586
TI - Overexpression, purification, crystallization and preliminary structural study of
dTDP-6-deoxy-L-lyxo-4-hexulose reductase (RmlD), the fourth enzyme of the dTDP-L
rhamnose synthesis pathway, from Salmonella enterica serovar Typhimurium.
AB - L-Rhamnose is an essential component of the cell wall of many pathogenic
bacteria. Its precursor, dTDP-L-rhamnose, is synthesized from alpha-D-glucose-1
phosphate and dTTP via a pathway requiring four distinct enzymes: RmlA, RmlB,
RmlC and RmlD. RmlD catalyses the terminal step of this pathway by converting
dTDP-6-deoxy-L-lyxo-4-hexulose to dTDP-L-rhamnose. RmlD from -Salmonella enterica
serovar Typhimurium has been overexpressed in Escherichia coli. The recombinant
protein was purified by a two--step protocol involving anion-exchange and
hydrophobic chromatography. Dynamic light-scattering experiments indicated that
the recombinant protein is monodisperse. Crystals of native and selenomethionine
enriched RmlD have been obtained using the sitting-drop vapour-diffusion method
with polyethylene glycol as precipitant. Diffraction data have been collected
from orthorhombic crystals of both native and selenomethionyl-derivatized
protein, allowing tracing of the protein structure.
PMID- 10666587
TI - Crystallization and preliminary crystal analysis of yeast hexokinase PI and PII.
AB - Hexokinase is the prime enzyme of the Embden-Meyerhof pathway and is responsible
for the first stage of energy conversion. It catalyzes the transfer of a
phosphate to glucose to form glucose-6-phosphate. Yeast hexokinase PII is also
known to play an important role in glucose signal transduction. Crystals of yeast
hexokinase isoforms PI and PII were obtained by vapour-diffusion techniques using
the hanging-drop method. Isoform PI crystals belong to the space group
P2(1)2(1)2(1), with unit-cell parameters a = 62.12, b = 78.87, c = 144.74 A. Unit
cell parameters for isoform PII crystals are a = b = 142.81, c = 58.46 A and the
space group is I4. Synchrotron diffraction data have been collected to 2.2 A
resolution from the isoform PII crystal, whereas isoform PI diffracted to 3.1 A.
PMID- 10666588
TI - Crystallization and preliminary X-ray analysis of Thermotoga maritima ribosome
recycling factor.
AB - Thermotoga maritima ribosome recycling factor (RRF) is one of the proteins
catalyzing the fourth step in prokaryotic protein synthesis, ribosome recycling.
The RRF protein was crystallized with ammonium sulfate. Native diffraction data
to 2.55 A resolution were obtained at the MAX II synchrotron from a flash-frozen
crystal at 100 K. The crystals belong to space group P4(1)2(1)2 or P4(3)2(1)2,
with unit-cell parameters a = b = 47, c = 298 A, and probably contain one monomer
per asymmetric unit.
PMID- 10666589
TI - Crystallization and preliminary X-ray diffraction data for a purple acid
phosphatase from sweet potato.
AB - Purple acid phosphatase from sweet potato is a homodimer of 110 kDa. Two forms of
the enzyme have been characterized. One contains an Fe-Zn centre similar to that
previously reported for red kidney bean purple acid phosphatase. Another isoform,
the subject of this work, is the first confirmed example of an Fe-Mn-containing
enzyme. Crystals of this protein have been grown from PEG 6000. They have unit
cell parameters a = b = 118.4, c = 287.4 A and have the symmetry of space group
P6(5)22, with one dimer per asymmetric unit. Diffraction data collected using a
conventional X--ray source from a cryocooled crystal extend to 2.90 A resolution.
The three-dimensional structure of the enzyme will provide insight into the
coordination of this novel binuclear metal centre.
PMID- 10666590
TI - Crystallization of the N-terminal domain of human sex hormone-binding globulin,
the major sex steroid carrier in blood.
AB - The amino-teminal laminin G-like domain of human sex hormone-binding globulin
(SHBG), which contains the steroid-binding site and the dimerization domain, has
been produced in Escherichia coli, purified to homogeneity and crystallized in
complex with 5alpha--dihydrotestosterone (DHT) in two different crystal forms.
Native data sets have been collected for tetragonal crystals (space group P4(1)22
or P4(3)22; unit-cell parameters a = 52.2, c = 148.4 A) diffracting to 3.3 A and
trigonal crystals (R32; a = 104.0, c = 84.4 A) diffracting to better than 1.6 A.
Since both crystal forms can only accommodate a single monomer in the asymmetric
unit and share twofold rotational symmetry, it is proposed that the homodimer of
this truncated form of SHBG, as observed in ultracentrifugation experiments,
displays C(2) point-group symmetry.
PMID- 10666591
TI - The porphobilinogen synthase family of metalloenzymes.
AB - The porphobilinogen synthase (PBGS) family of enzymes catalyzes the first common
step in the biosynthesis of the essential tetrapyrroles such as chlorophyll and
porphyrin. Although PBGSs are highly conserved at all four levels of protein
structure, there is considerable diversity in the use of divalent cations for the
catalytically essential and allosteric roles. Assumptions regarding commonalities
among the PBGS proteins coupled with the diversity of usage of metal ions has led
to a confused literature. The recent publication of crystal structures for three
PBGS proteins coupled with more than 50 individual PBGS sequences allows an
evaluation of these assumptions. This topical review focuses on the usage of
metals by the PBGS family of proteins. It raises doubt concerning a dogma that
there has been an evolutionary shift between Zn(II) and Mg(II) at one or more of
the divalent metal-binding sites. It also raises the possibility that there may
be up to four specific divalent metal ion-binding sites, each serving a unique
function that can be alternatively filled by amino acids in some of the PBGSs.
PMID- 10666592
TI - Structure of xylose isomerase from Streptomyces diastaticus no. 7 strain M1033 at
1.85 A resolution.
AB - The structure of xylose isomerase (XyI) from Streptomyces diastaticus No. 7
strain M1033 (SDXyI) has been refined at 1.85 A resolution to conventional and
free R factors of 0.166 and 0.219, respectively. SDXyI was crystallized in space
group P2(1)2(1)2, with unit-cell parameters a = 87.976, b = 98.836, c = 93.927 A.
One dimer of the tetrametric molecule is found in each asymmetric unit. Each
monomer consists of two domains: a large N-terminal domain (residues 1-320),
containing a parallel eight-stranded alpha/beta barrel, and a small C-terminal
loop (residues 321-387), containing five helices linked by random coil. The four
monomers are essentially identical in the tetramer, possessing non
crystallographic 222 symmetry with one twofold axis essentially coincident with
the crystallographic twofold axis in the space group P2(1)2(1)2, which may
explain why the diffraction pattern has strong pseudo-I222 symmetry even at
medium resolution. The crystal structures of XyIs from different bacterial
strains, especially from Streptomyces, are similar. The alpha2 helix of the
alpha/beta barrel has a different position in the structures of different XyIs.
The conformation of C-terminal fragment 357-364 in the SDXyI structure has a
small number of differences to that of other XyIs. Two Co(2+) ions rather than
Mg(2+) ions exist in the active site of the SDXyI structure; SDXyI seems to
prefer to bind Co(2+) ions rather than Mg(2+) ions.
PMID- 10666593
TI - The molecular structure and structural transition of the alpha-helical capsid in
filamentous bacteriophage Pf1.
AB - The major coat protein in the capsid of Pf1 filamentous bacteriophage (Inovirus)
forms a helical assembly of about 7000 identical protein subunits, each of which
contains 46 amino-acid residues and can be closely approximated by a single
gently curved alpha-helix. Since the viral DNA occupies the core of the tubular
capsid and appears to make no significant specific interactions with the capsid
proteins, the capsid is a simple model system for the study of the static and
dynamic properties of alpha-helix assembly. The capsid undergoes a reversible
temperature-induced structural transition at about 283 K between two slightly
different helix forms. The two forms can coexist without an intermediate state,
consistent with a first-order structural phase transition. The molecular model of
the higher temperature form was refined using improved X-ray fibre diffraction
data and new refinement and validation methods. The refinement indicates that the
two forms are related by a change in the orientation of the capsid subunits
within the virion, without a significant change in local conformation of the
subunits. On the higher temperature diffraction pattern there is a region of
observed intensity that is not consistent with a simple helix of identical
subunits; it is proposed that the structure involves groups of three subunits
which each have a slightly different orientation within the group. The grouping
of subunits suggests that a change in subunit libration frequency could be the
basis of the Pf1 structural transition; calculations from the model are used to
explore this idea.
PMID- 10666594
TI - Towards the charge-density study of proteins: a room-temperature scorpion-toxin
structure at 0.96 A resolution as a first test case.
AB - The number of protein structures refined at a resolution higher than 1.0 A is
continuously increasing. Subatomic structures may deserve a more sophisticated
model than the spherical atomic electron density. In very high resolution
structural studies (d < 0.5 A) of small peptides, a multipolar atom model is used
to describe the valence electron density. This allows a much more accurate
determination of the anisotropic thermal displacement parameters and the estimate
of atomic charges. This information is of paramount importance in the
understanding of biological processes involving enzymes and metalloproteins. The
structure of the scorpion Androctonus australis Hector toxin II has been refined
at 0.96 A resolution using synchrotron diffraction data collected at room
temperature. Refinement with a multipolar electron-density model in which the
multipole populations are transferred from previous peptide studies led to the
observation of valence electrons on covalent bonds of the most ordered residues.
The refined net charges of the peptide-bond atoms were of the correct sign but
were underestimated. Such protein-structure refinements against higher resolution
data collected at cryogenic temperature will enable the calculation of
experimental atomic charges and properties such as electrostatic potentials.
PMID- 10666595
TI - Mass-spectrometry assisted heavy-atom derivative screening of human Fc gamma RIII
crystals.
AB - A heavy-atom screening method aided by mass spectrometry is described here. Using
mass spectrometry, several heavy-atom compounds have been screened in order to
obtain potential phasing derivatives for the crystals of a human immunoglobulin
Fc receptor, Fc gamma RIII. Of these, HgCl(2), trimethyllead acetate (TMLA),
KAu(CN)(2), K(2)PtCl(4) and PbAc(2) reacted with Fc gamma RIII in solution,
whereas KAuCl(4), ethylmercuric thiosalicylate (EMTS) and Na(2)WO(4) did not. To
validate the mass-spectrometry results, these heavy-atom compounds were also used
to soak crystals of Fc gamma RIII and crystallographic data were collected after
soaking. The calculated R(iso) indicated that HgCl(2), TMLA, K(2)PtCl(4) and
PbAc(2) were likely to form derivatives, whereas KAu(CN)(2) and Na(2)WO(4) were
not. The anomalous difference Patterson maps calculated for the HgCl(2) and TMLA
derivative data sets were of good quality and can readily be interpreted by hand.
In general, the number of binding sites obtained from the crystallographic phase
refinement of the derivatives agrees with those obtained from the mass
spectrometry, suggesting that mass spectrometry can be applied for rapid
searching of suitable heavy-atom derivatives for X-ray crystallography.
PMID- 10666596
TI - A stochastic approach to molecular replacement.
AB - The classical approach to the problem of placing n copies of a search model in
the asymmetric unit of a target crystal structure is to divide this 6n
dimensional optimization problem into a succession of three-dimensional searches
(rotation-function followed by translation-function searches for each of the
models). Here, it is shown that a structure-determination method based on a
reverse Monte Carlo minimization of a suitably chosen statistic in the 6n
dimensional space defined by the rotational and translational parameters of the n
molecules is both feasible and practical, at least for small n. Because all
parameters of all molecules are determined simultaneously, this algorithm is
expected to improve the signal-to-noise ratio in difficult cases involving high
crystallographic/non-crystallographic symmetry in tightly packed crystal forms.
Preliminary results from the application of this method (obtained with a space
group general computer program which has been developed for this purpose) are
presented.
PMID- 10666597
TI - A rational approach towards successful crystallization and crystal treatment of
human cytomegalovirus protease and its inhibitor complex.
AB - The crystallization and subsequent crystal treatment of both free human
cytomegalovirus (hCMV) protease and its inhibitor complexes are reported. For
free-enzyme crystals, diffraction was greatly improved by optimizing the
crystallization conditions, raising the precipitant concentration in the
reservoir and soaking the crystals in artificial mother liquors. Each of the six
components in the final crystallization formula (16% PEG 4000, 0.1 M MES pH 6.0,
0.4 M LiCl, 10% glycerol, 5% t-butanol and 5 mM Na(2)S(2)O(3)) plays a
distinctive role and is indispensable. A synergistic effect of Na(2)SO(4) and t-
butanol on diffraction was observed and studied. A 2.0 A multiwavelength
anomalous diffraction (MAD) data set was collected using a synchrotron-radiation
source, leading to the elucidation of the three-dimensional structure of the
enzyme. For the inhibitor-complex crystals, initial attempts with co
crystallization and soaking experiments at pH 6.0 did not produce conclusive
results. Subsequently, experiments were designed to co-crystallize the complex at
pH 8.0, the optimal pH for the enzyme and the inhibitor activity. Using 20-50 mM
spermine in the crystallization buffer, crystals of two peptidomimetic inhibitor
complexes were obtained at pH 7.5 and 8.0. Spermine was required for the
inhibitor complexes to be crystallized at pH 8.0, possibly neutralizing net
negative charges of hCMV protease owing to its acidic pI of 5.5. A 2.7 A data set
was collected from one of the inhibitor complexes and the structure was
determined using the molecular-replacement method.
PMID- 10666598
TI - Crystallization and preliminary X-ray analysis of an intracellular xylanase from
Bacillus stearothermophilus T-6.
AB - Xylanases (1,4-beta-D-xylan xylanhydrolases; E.C. 3.2.1.8) hydrolyze the 1,4-beta
D-xylopyranosyl linkage of xylans. The structural characterization of xylanase
active sites is of great interest, since it can lead to a better understanding of
their catalytic mechanism and contribute significant knowledge to the rational
design of specific oligosaccharide-binding sites via protein engineering. An
intracellular xylanase gene (xynA2) from Bacillus stearothermophilus T-6 has
recently been cloned and sequenced. The xynA2 gene encodes for an intracellular
enzyme (IXT6) of 331 amino acids, with a calculated molecular weight of 38 639 Da
and a pI of 5.72. Based on sequence homology, the enzyme belongs to family 10 of
the glycosyl hydrolases. The xynA2 gene product (IXT6) was overproduced in
Escherichia coli and purified to homogeneity. Crystallographic studies of IXT6
were initiated in order to study the specificity and mechanism of catalysis of
this unique xylanase, as well as to provide a structural basis for rational
introduction of enhanced thermostability by site-specific mutagenesis. The M1
crystal form was found to be the most suitable for detailed crystal structure
analysis. These crystals belong to a C--centered monoclinic crystal system (space
group C2) with unit-cell parameters a = 170.6, b = 82.5, c = 80.0 A, beta = 91.43
degrees. They are mechanically strong, are fairly stable in the X-ray beam and
diffract X--rays to better than 2.5 A resolution. A full 2.9 A resolution
diffraction data set (97.9% completeness, R(merge) = 8.4%) has recently been
collected from one crystal at room temperature using X-ray synchrotron radiation
(lambda = 1.125 A) and a MAR300 imaging-plate area detector. A comparable 2.5 A
data set was measured at 90 K using a rotating-anode X-ray source and an R-AXIS
IIc imaging-plate area detector (97.2% completeness, R(merge) = 6.9%). Molecular
replacement studies and multiple anomalous dispersion (MAD) experiments are
currently in progress in order to determine the detailed three-dimensional
structure of IXT6.
PMID- 10666599
TI - Crystallization and preliminary X-ray analysis of luffaculin, a ribosome
inactivating protein from sponge-gourd seeds.
AB - Luffaculin is a ribosome-inactivating protein. Crystals suitable for X--ray
diffraction were first obtained using the hanging-drop vapour-diffusion method. X
ray studies show that the crystals belong to space group C2, with unit-cell
parameters a = 89.90, b = 59.82, c = 55.18 A, beta = 120.81 degrees, and have one
molecule in the crystallographic asymmetric unit. The crystals diffract X-rays to
at least 2.0 A resolution.
PMID- 10666600
TI - Crystallization and preliminary X-ray crystallographic analysis of the 30 kDa
membrane-binding domain of protein 4.1 from human erythrocytes.
AB - The 30 kDa membrane-binding domain of protein 4.1 from human erythrocytes has
been expressed in Escherichia coli and crystallized in a form suitable for X-ray
crystallographic study. Crystals were grown using a salting-in technique.
Crystals have a tetragonal plate shape and belong to the C2 space group, with
unit-cell parameters a = 163.9, b = 106.5, c = 93.5 A, beta = 95.5 degrees. The
crystals diffract to 2.8 A resolution.
PMID- 10666601
TI - Crystallization and preliminary X-ray diffraction analysis of human calcium
binding protein S100A12.
AB - S100A12, a member of the calgranulin family, isolated from human blood, has been
crystallized by vapour diffusion in the presence of Ca(2+). Crystals belong to
the space group R3 with unit-cell dimensions a = b = 99.6 c = 64.2 A. There are
two monomers per asymmetric unit, with a solvent content of 57.9%. The crystals
diffract to at least 2.2 A resolution and complete X-ray data have been collected
to 2.5 A on a conventional laboratory source.
PMID- 10666602
TI - Crystallization and preliminary X-ray diffraction analysis of the catalytic
subunit of ADP-glucose pyrophosphorylase from potato tuber.
AB - ADP-glucose pyrophosphorylase is the key regulatory enzyme in the biosynthesis of
starch in plants and glycogen in bacteria. The enzyme from potato tuber is
comprised of a regulatory subunit and a catalytic subunit and is present as a
heterotetramer (alpha(2)beta(2)). The catalytic subunit from potato tuber (50
kDa) was crystallized in four different forms, two of which are suitable for
structural studies. A tetragonal crystal form obtained in the presence of the
substrate analog Cr-ATP diffracted to 2.2 A and belongs to space group P4(1) (or
its enantiomorph), with unit-cell parameters a = b = 110.57, c = 190.14 A. A
second crystal form obtained diffracted to 2.8 A and belongs to space group P2,
with unit-cell parameters a = 80.06, b = 138.84, c = 92.20 A, beta = 112. 40
degrees. As this protein displays no significant homology to any currently known
protein structure, a search for heavy-atom derivatives has been initiated.
PMID- 10666603
TI - Crystallization and preliminary X-ray diffraction analysis of Thermus
thermophilus prolyl-tRNA synthetase.
AB - Prolyl-tRNA synthetase from Thermus thermophilus (ProRSTT) was purified to
homogeneity using a five-step purification procedure and was crystallized using
ethylene glycol as a precipitant. Crystals of ProRSTT belong to the space group
P2(1)2(1)2, with unit-cell parameters a = 132, b = 191, c = 125 A, have two
homodimers per asymmetric unit and diffract to 2.4 A resolution. A complete
native data set to 2.43 A resolution has been collected and a data set from
ProRSTT in complex with proline has been collected to 2.9 A resolution.
PMID- 10666604
TI - Improved crystals of Thermus thermophilus prolyl-tRNA synthetase complexed with
cognate tRNA obtained by crystallization from precipitate.
AB - The complex between Thermus thermophilus prolyl-tRNA synthetase (ProRSTT) and its
cognate tRNA has been crystallized using two different isoacceptors of tRNA(Pro).
Similar bipyramidal crystals of the complexes of ProRSTT with the two different
tRNA(Pro) isoacceptors grow within two weeks from 32% saturated ammonium sulfate
solution. They belong to space group P4(3)2(1)2, with unit-cell parameters a =
143.1, b = 143.1, c = 228.6 A. The crystals diffract weakly to a maximum
resolution of 3.1 A. Superior quality crystals were obtained by growing slowly
from precipitate over 5-6 months. These are of the same space group but have
slightly altered unit-cell parameters, a = 140.8, b = 140.8, c = 237.0 A. These
crystals diffract more strongly to at least 2.8 A resolution and a complete data
set to 2.85 A resolution has been collected from a single crystal. Comparison of
the packing in the two crystal forms shows that domain flexibility contributes to
the presence of different crystal contacts in the two forms.
PMID- 10666605
TI - Purification, crystallization and preliminary X-ray crystallographic study of
alpha-amylase from Bacillus stearothermophilus.
AB - A recombinant alpha-amylase from Bacillus stearothermophilus was found to be
produced as several isoforms arising from different N--terminal processing. Some
of those isoforms were purified to homogeneity and crystallized at 293 K using
the hanging-drop vapour-diffusion method under the following conditions: 35 mM
sodium acetate (pH 4.6), 6.25%(v/v) 2-propanol, in the presence of 1.23%(w/v)
acarbose (a pseudo-oligosaccharide inhibitor) in the drop. The crystals
diffracted beyond 2.0 A resolution using synchrotron radiation at the Photon
Factory, Tsukuba. They belong to the monoclinic space group P2(1), with unit-cell
parameters a = 53.7 (2), b = 92.9 (4), c = 53.2 (2) A, beta = 109.4 (1) degrees.
PMID- 10666606
TI - Crystallization and preliminary X-ray studies of recombinant amylosucrase from
Neisseria polysaccharea.
AB - Recombinant amylosucrase from Neisseria polysaccharea was crystallized by the
vapour-diffusion procedure in the presence of polyethylene glycol 6000. The
crystals belong to the orthorhombic space group P2(1)2(1)2, with unit-cell
parameters a = 95.7, b = 117.2, c = 62.1 A, and diffract to 1.6 A resolution. A p
chloromercuribenzene sulfonate (pcmbs) derivative has been identified and a
selenomethionine-substituted protein has been produced and crystallized.
PMID- 10666607
TI - Crystallization and preliminary crystallographic analysis of
phosphonoacetaldehyde hydrolase.
AB - Phosphonoacetaldehyde hydrolase, a C-P bond-cleaving enzyme which utilizes an
unusual bicovalent catalytic strategy, has been crystallized by the hanging-drop
vapor-diffusion method using PEG 4000 as the precipitant. The crystals belong to
the monoclinic system and belong to space group C2, with unit-cell parameters a =
210.5, b = 45.5, c = 64.7 A, beta = 105.0 degrees. The asymmetric unit contains a
dimer related by a non-crystallographic dyad. In addition to a 2.7 A native data
set, the following data sets have been collected: a 2.4 A data set from crystals
complexed with the intermediate analog vinyl sulfonate, a 3.0 A three-wavelength
MAD data set from crystals complexed with the product analog WO(4)(2-), as well
as several heavy-atom data sets to 3.0 A or better, of which only three have
proven useful for MIR calculations. Examination of the native Patterson map
revealed NCS that made previously uninterpretable derivative data useful.
Independent phase sets were first calculated and refined for the MAD and MIR
experiments separately and were then combined. The combined phase set was further
improved by solvent flattening, histogram matching and NCS averaging.
Interpretation of the resulting electron-density map is currently under way.
PMID- 10666608
TI - Crystallization and preliminary X-ray diffraction studies of a beta-carbonic
anhydrase from the red alga Porphyridium purpureum.
AB - The beta-carbonic anhydrase from the red alga Porphyridium purpureum was
heterologously expressed, purified and crystallized. The crystals belong to space
group P2(1) (unit-cell parameters a = 63.8, b = 113.9, c = 73.8 A, beta = 104.1
degrees) with two subunits per asymmetric unit and diffract to 2.5 A resolution.
PMID- 10666609
TI - Expression, crystallization and preliminary X-ray studies of the PDZ domain of
Dishevelled protein.
AB - Dishevelled (Dsh) protein is an important component of the Wnt signal
transduction pathway. It has three relatively conserved domains: DIX, PDZ and
DEP. The PDZ domain of the Xenopus laevis homolog of Dsh, which consists of
residues 254-348, was overexpressed as a soluble protein in Escherichia coli,
purified and crystallized. The crystals were obtained by the vapor-diffusion
method, using 1.4 M sodium formate as a precipitant. The crystals diffracted to
2.3 A resolution. The space group was determined to be P6(1)22 or P6(5)22, with
unit-cell dimensions a = b = 95.9, c = 93.9 A.
PMID- 10666610
TI - Crystallization and preliminary X-ray analysis of a membrane-bound nitrite
reductase from Desulfovibrio desulfuricans ATCC 27774.
AB - Nitrite reductase from the sulfate-reducing bacterium Desulfovibrio desulfuricans
ATCC 27774 is a multihaem (type c) membrane-bound enzyme that catalyzes the
dissimilatory conversion of nitrite to ammonia. Crystals of the oxidized form of
this enzyme were obtained using PEG and CaCl(2) as precipitants in the presence
of 3--(decylmethylammonium)propane-1-sulfonate and belong to the space group
P2(1)2(1)2(1), with unit-cell parameters a = 78.94, b = 104.59, c = 143.18 A. A
complete data set to 2.30 A resolution was collected using synchrotron radiation
at the ESRF. However, the crystals may diffract to beyond 1.7 A and high
resolution data will be collected in the near future.
PMID- 10666611
TI - X-ray studies of recombinant anti-testosterone Fab fragments: the use of PEG 3350
in crystallization.
AB - Recombinant anti-testosterone wild-type Fab fragment and mutant Fab fragments
with high binding selectivity developed by protein engineering have been
crystallized with and without ligands. Crystals of these Fab fragments were
obtained by the vapour-diffusion technique at room temperature using solutions of
PEG 3350 with various biological buffers and with a wide pH range. So far, five
data sets have been collected from crystals of three Fab-antigen complexes and
from two uncomplexed Fab fragments, with resolutions ranging from 2.10 to 3.1 A.
Crystallization conditions for Fab fragments were found by using modifications of
the low ionic strength PEG 3350 series. Suitable concentrations of PEG 400, MPD
and glycerol solutions for use as cryoprotectants in PEG 3350 solutions have been
determined. One useful observation was that PEG 3350 is able to work alone as a
cryoprotectant. The screening protocol used requires a smaller amount of protein
material to achieve auspicious pre-crystals than previously. Results support the
claim that PEG 3350 is more suitable for the crystallization of Fab fragments
than higher molecular weight PEGs.
PMID- 10666612
TI - The purification, crystallization and structural elucidation of dTDP-D-glucose
4,6-dehydratase (RmlB), the second enzyme of the dTDP-L-rhamnose synthesis
pathway from Salmonella enterica serovar typhimurium.
AB - dTDP-D-glucose 4,6-dehydratase (RmlB) is the second of four enzymes involved in
the dTDP-L-rhamnose pathway and catalyzes the dehydration of dTDP-D-glucose to
dTDP-4-keto-6-deoxy-D-glucose. The ultimate product of the pathway, dTDP-L
rhamnose, is the precursor of L-rhamnose, which is a key component of the cell
wall of many pathogenic bacteria. RmlB from Salmonella enterica serovar
Typhimurium has been overexpressed and purified, and crystals of the enzyme have
been grown using the sitting-drop vapour-diffusion technique with lithium sulfate
as precipitant. Diffraction data have been obtained to a resolution of 2.8 A on a
single frozen RmlB crystal which belongs to space group P2(1), with unit-cell
parameters a = 111.85, b = 87.77, c = 145.66 A, beta = 131.53 degrees. The
asymmetric unit contains four monomers in the form of two RmlB dimers with a
solvent content of 62%. A molecular-replacement solution has been obtained and
the model is currently being refined.
PMID- 10666613
TI - Crystallization and preliminary X-ray analysis of the thymidylate kinase from
Mycobacterium tuberculosis.
AB - Mycobacterium tuberculosis thymidylate kinase complexed with the substrate
deoxythymidine monophosphate was crystallized in the hexagonal space group
P6(5)22 or P6(1)22, with unit-cell parameters a = b = 76.62, c = 134.38 A and one
single monomer of 23 kDa in the asymmetric unit. Cryo-cooled crystals diffract at
1.94 A resolution using synchrotron radiation.
PMID- 10666614
TI - Crystallization and preliminary X-ray diffraction analysis of the Saccharomyces
cerevisiae ran-binding protein Mog1p.
AB - Mog1p binds the Ras-family GTPase Ran/Gsp1p, which has a central role in
nucleocytoplasmic transport and cell-cycle progression. Overexpression of MOG1 is
able to suppress temperature-sensitive gsp1 mutants in yeast; Deltamog1 null
mutants display temperature-sensitive defects in nuclear trafficking.
Orthorhombic crystals of bacterially expressed Mog1p that diffract to beyond 2 A
resolution using synchrotron radiation have been obtained. The crystals have
P2(1)2(1)2(1) symmetry, with unit-cell parameters a = 39.67, b = 51.96, c =
112.23 A, a Matthews coefficient of 2.44 A(3) Da(-1), an estimated solvent
content of 49.5% and one chain in the asymmetric unit.
PMID- 10666615
TI - Novel approach to phasing proteins: derivatization by short cryo-soaking with
halides.
AB - A quick (less than 1 min) soak of protein crystals in a cryo-solution containing
bromide or iodide anions leads to incorporation of these anomalous scatterers
into the ordered solvent region around the protein molecules. These halide anions
provide a convenient way of phasing through their anomalous scattering signal:
bromides using multiwavelength anomalous dispersion (MAD) and bromides and/or
iodides using single-wavelength anomalous dispersion (SAD) or single isomorphous
replacement with anomalous scattering (SIRAS) methods. This approach has been
tested successfully on four different proteins and has been used to solve the
structure of a new protein of molecular weight 30 kDa.
PMID- 10666616
TI - P1 Shake-and-Bake: can success be guaranteed?
AB - The multi-trial direct-methods procedure known as Shake-and-Bake has been applied
to three small proteins (alpha-1 peptide, vancomycin and lysozyme) that
crystallize in space group P1. Phase refinement was accomplished through
parameter-shift optimization using both the cosine and exponential forms of the
minimal function. By extending error-free data to sufficiently high resolution,
100% convergence of trial structures to solution could be achieved in all three
cases by using the exponential minimal function and a shift angle in the range
130-150 degrees. These results suggest optimum parameters for other P1 structures
and emphasize the importance of collecting data to the highest possible
resolution.
PMID- 10666617
TI - Structure of human erythrocyte catalase.
AB - Catalase (E.C. 1.11.1.6) was purified from human erythrocytes and crystallized in
three different forms: orthorhombic, hexagonal and tetragonal. The structure of
the orthorhombic crystal form of human erythrocyte catalase (HEC), with space
group P2(1)2(1)2(1) and unit-cell parameters a = 84.9, b = 141.7, c = 232.5 A,
was determined and refined with 2.75 A resolution data. Non-crystallographic
symmetry restraints were employed and the resulting R value and R(free) were
0.206 and 0.272, respectively. The overall structure and arrangement of HEC
molecules in the orthorhombic unit cell were very similar to those of bovine
liver catalase (BLC). However, no NADPH was observed in the HEC crystal and a
water was bound to the active-site residue His75. Conserved lattice interactions
suggested a common growth mechanism for the orthorhombic crystals of HEC and BLC.
PMID- 10666619
TI - Biological crystallography goes online
PMID- 10666618
TI - A preliminary neutron Laue diffraction study of the aspartic proteinase
endothiapepsin.
AB - Until now, no aspartic proteinase has been subjected to a successful neutron
diffraction analysis, owing to the limited size of the crystals. However, the
recent development of the neutron Laue technique at ILL and EMBL (Grenoble) has
allowed the collection of data to 2.2 A on a complex of endothiapepsin with a
transition-state analogue. The objective is to define the positions of the
protons at the active site by refinement using the neutron data. In line with
work on serine proteinases, where neutron diffraction has provided some of the
most definitive data on the catalytic mechanism, it is expected that this work
will have a major significance for studies of the aspartic proteinase enzymes.
PMID- 10666620
TI - Guidelines for the deposition and release of macromolecular coordinate and
experimental data
PMID- 10666621
TI - The three-dimensional structure of a Trichoderma reesei beta-mannanase from
glycoside hydrolase family 5.
AB - The crystal structure of the catalytic core domain of beta-mannanase from the
fungus Trichoderma reesei has been determined at a resolution of 1.5 A. The
structure was solved using the anomalous scattering from a single non-isomorphous
platinum complex with two heavy-metal sites in space group P2(1). The map
computed with the experimental phases was enhanced by the application of an
automated model building and refinement procedure using the amplitudes and
experimental phases as observations. This approach is expected to be of more
general application. The structure of the native enzyme and complexes with Tris
HCl and mannobiose are also reported: the mannobiose binds in subsites +1 and +2.
The structure is briefly compared with that of the homologous beta-mannanase from
the bacterium Thermomonospora fusca.
PMID- 10666622
TI - The 2.0 A structure of bovine interferon-gamma; assessment of the structural
differences between species.
AB - The structure of bovine interferon-gamma (IFN-gamma) was determined by multiple
isomorphous replacement at 2.0 A resolution. Bovine IFN-gamma crystallizes in two
related crystal forms. Crystal form 1 diffracts to 2.9 A resolution and is
reproducible and stable to derivatization. Crystal form 2 diffracts to 2.0 A
resolution, but shows significant non-isomorphism from crystal to crystal. The
previously determined structures of several different species of INF-gamma were
either at too low a resolution [human, 1hig; Ealick et al. (1991), Science, 252,
698-702] or were too inaccurate [bovine, 1rfb; Samudzi & Rubin (1993), Acta
Cryst. D49(6), 505-512; rabbit, 2rig; Samudzi et al. (1991), J. Biol. Chem.
266(32), 21791-21797] for the structure to be solved by molecular replacement.
The structure was solved in crystal form 1 using two derivatives produced by
chemically modifying two free cysteine residues that were introduced by site
directed mutagenesis (Ser30Cys, Asn59Cys). After model building and refinement,
the final R value was 21.8% (R(free) = 30.9%) for all data in the resolution
range 8.0-2.9 A. The crystal form 1 structure was then used as a molecular
replacement model for crystal form 2 data collected from a flash-cooled crystal.
Subsequent model building and refinement, using all data in the resolution range
15.0-2.0 A, gave an R value of 19.7% and an R(free) of 27.5%. Pairwise comparison
of C(alpha) positions of bovine IFN-gamma (BOV) and the previously determined
1rfb and 2rig structures indicated some significant differences in the models
(r.m.s.d. values for BOV to 1rfb, 4.3 A; BOV to 2rig, 4.0 A). An assessment of
the quality of the structures was made using the 3D-1D algorithm [Eisenberg et
al. (1992), Faraday Discuss. 93, 25-34]. The resulting statistical scoring
indicated that BOV was consistent with expected criteria for a 2.0 A structure,
whereas both 1rfb and 2rig fell below acceptable criteria.
PMID- 10666623
TI - Structure of a new neurotoxin from the scorpion Buthus martensii Karsch at 1.76
A.
AB - A new neurotoxin BmK M2, toxic to both mammals and insects, with the strongest
toxicity in the BmK toxin series, has been purified from the Chinese scorpion
Buthus martensii Karsch and crystallized with MPD at pH 7.5. The crystals are
orthorhombic, belonging to space group P2(1)2(1)2(1), with unit-cell parameters a
= 36.64, b = 36.95, c = 37.23 A. The structure was solved by molecular
replacement and refined to R = 0.186 for all reflections to a resolution of 1.76
A. The whole sequence (64 residues) of BmK M2 was determined by crystallographic
analysis based on high-resolution data and the homologous model of BmK M8. The
refined BmK M2 structure shows a non-proline cis peptide bond between Pro9 and
His10 which enables the C-terminal segment to adopt a conformation different to
that of the weak toxin BmK M8. Recently, a mutation analysis had suggested that
both the tenth residue and the C-terminus play key roles in receptor binding.
Therefore, these features may be related to the binding selectivity of the group
III alpha-like toxins. The charge changes of residues 8, 10, 18, 28, 55 and 59
from neutral or negative to positive or neutral, which leads to a positive
electrostatic potential surface, may be responsible for the high toxicity of BmK
M2.
PMID- 10666624
TI - 1.35 and 2.07 A resolution structures of the red abalone sperm lysin monomer and
dimer reveal features involved in receptor binding.
AB - Abalone sperm use lysin to make a hole in the egg's protective vitelline envelope
(VE). When released from sperm, lysin first binds to the VE receptor for lysin
(VERL) then dissolves the VE by a non-enzymatic mechanism. The structures of the
monomeric and dimeric forms of Haliotis rufescens (red abalone) lysin, previously
solved at 1.90 and 2.75 A, respectively, have now been refined to 1.35 and 2.07
A, respectively. The monomeric form of lysin was refined using previously
obtained crystallization conditions, while the dimer was solved in a new crystal
form with four molecules (two dimers) per asymmetric unit. These high-resolution
structures reveal alternate residue conformations, enabling a thorough analysis
of the conserved residues contributing to the amphipathic nature of lysin. The
availability of five independent high-resolution copies of lysin permits
comparisons leading to insights on the local flexibility of lysin and alternative
conformations of the hypervariable N-terminus, thought to be involved in species
specific receptor recognition. The new analysis led to the discovery of the basic
nature of a cleft formed upon dimerization and a patch of basic residues in the
dimer interface. Identification of these features was not possible at lower
resolution. In light of this new information, a model explaining the binding of
sperm lysin to egg VERL and the subsequent dissolution of the egg VE is proposed.
PMID- 10666625
TI - RSPS version 4.0: a semi-interactive vector-search program for solving heavy-atom
derivatives.
AB - A program for inspection and interpretation of the Patterson function is
described. The program is mainly intended for finding heavy-atom positions from
difference Patterson maps, but may also be used to locate molecules with non
crystallographic symmetry when the local axis is nearly parallel to a
crystallographic symmetry axis. Options are available for vector-based methods to
locate heavy-atom sites, for finding sets from a list of possible heavy-atom
positions and for checking of potential solutions. Both crystallographic and non
crystallographic symmetry may be used, either independently or in conjunction.
PMID- 10666626
TI - Real-time swelling-series method improves the accuracy of lamellar neutron
diffraction data.
AB - Neutron-diffraction data were collected from stacked bilayers of 1, 2-dioleoyl-sn
glycero-phosphocholine under conditions of increasing relative humidity at both 0
and 8.06% (2)H(2)O. Over the period of data collection, the d-repeat of both
swelling-series samples increased. Each family of structure factors, representing
each of the five orders of diffraction, are shown to lie on smooth curves,
allowing structure factors of intermediate d-repeat to be determined. In the case
of the 8.06% (2)H(2)O data, but not the 0% (2)H(2)O data, all observed structure
factors lie on a single continuous transform. 8.06% (2)H(2)O has a net neutron
scattering density of zero; its use in neutron-diffraction experiments presents a
novel application of the so-called 'minus fluid' approach, without mathematical
manipulation. The data are used to demonstrate the increased accuracy inherent in
this real-time swelling-series approach. A quantitative analysis of errors caused
by differences in d--repeat in difference subtractions is presented.
PMID- 10666627
TI - Effects of microgravity on the crystal quality of a collagen-like polypeptide.
AB - (Pro-Pro-Gly)(10) is one of the most widely studied collagen polypeptide models.
Microgravity crystal growth of (Pro-Pro-Gly)(10) was carried out in the Advanced
Protein Crystallization Facility aboard the Space Shuttle Discovery during the
STS-95 mission. Crystals were successfully grown in all experiments, using both
dialysis and free-interface diffusion methods. The quality of the microgravity
grown crystals and of ground-grown counterparts was assessed by X-ray synchrotron
diffraction. Microgravity-grown crystals exhibited a significant improvement in
terms of dimensions and resolution limit. As previously reported, crystals were
orthorhombic, space group P2(1)2(1)2(1). However, the diffraction pattern showed
weak reflections, never previously measured, that were consistent with new unit
cell parameters a = 26.9, b = 26.4, c = 182.5 A. This allowed the derivation of a
new model for the arrangement of the triple-helical molecules in the crystals.
PMID- 10666628
TI - Crystallization and preliminary X-ray diffraction studies of human epidermal
growth factor.
AB - Human epidermal growth factor (hEGF), a 6.2 kDa protein of 53 amino acids with
three internal disulfide bridges, has been crystallized by the hanging-drop
method. hEGF crystallizes in space group P3(1)21 (or P3(2)21) using MgCl(2) as
precipitant, with unit-cell parameters a = b = 61.4, c = 87.0 A. Another type of
crystal, obtained using NaCl as precipitant, belongs to a tetragonal point group
and has unit-cell dimensions a = b = 102.5, c = 166.6 A. The trigonal crystals
with the smaller unit cell diffract X-rays better and a native data set from a
single crystal has been collected to 3.0 A resolution.
PMID- 10666629
TI - Crystallization and preliminary X-ray diffraction studies on the N-utilizing
substance-B (NusB) from Mycobacterium tuberculosis.
AB - N-utilizing substance B (NusB) is a protein which forms part of a complex
assembly in transcriptional antitermination in Mycobacterium tuberculosis. It
forms a heterodimer with the product of the NusE gene (identical to the ribosomal
protein S10) and mediates the process of transcriptional antitermination by
forming the core complex with the nut site of the ribosomal RNA along with other
protein factors. NusB has been cloned and overexpressed in Escherichia coli and
crystallized using the hanging-drop vapour-diffusion method. The space group is
P2(1)2(1)2(1), with unit-cell parameters a = 46.6, b = 64.2, c = 90.1 A. A native
data set complete to 1.6 A resolution has been collected from a single crystal.
PMID- 10666630
TI - Crystallization and preliminary X-ray analyses of catabolite control protein A,
free and in complex with its DNA-binding site.
AB - The catabolite control protein (CcpA) from Bacillus megaterium is a member of the
bacterial repressor protein family GalR/LacI. CcpA with an N-terminal His-tag was
used for crystallization. Crystals of free CcpA and of CcpA in complex with the
putative operator sequence (catabolite responsive elements, CRE) were obtained by
vapour-diffusion techniques at 291 K using the hanging-drop method. CcpA crystals
grown in the presence of polyethylene glycol 8000 belong to the hexagonal space
group P6(1)22 or P6(5)22, with unit-cell parameters a = 74.4, c = 238.8 A. These
crystals diffract X-rays to 2.55 A resolution and contain one monomer of the
homodimeric protein per asymmetric unit. Crystals of the CcpA-CRE complex were
obtained with ammonium sulfate as precipitant and belong to the tetragonal space
group I4(1)22, with unit-cell parameters a = 125, c = 400 A and one complex per
asymmetric unit. Although these co-crystals grew to a sufficient size, X-ray
diffraction was limited to 8 A resolution.
PMID- 10666631
TI - Crystallization and preliminary diffraction studies of a truncated form of a
novel protease from spores of Bacillus megaterium.
AB - During germination of spores of Bacillus species, a novel protease termed GPR
initiates the degradation of a group of small acid-soluble spore proteins which
protect the dormant spore's DNA from damage. Trypsin digestion of the zymogen of
B. megaterium GPR removes approximately 15 kDa from the C-terminal end of the 46
kDa zymogen subunit, leaving a 30 kDa subunit. Single crystals of this truncated
form of GPR have been obtained by the vapor-diffusion method using PEG 4000 as a
precipitating agent. The crystals belong to the monoclinic space group P2(1),
with unit-cell parameters a = 67.99, b = 105.34, c = 108.63 A, beta = 95.68
degrees. The cryofrozen crystals diffract X-rays to about 3.3 A using synchrotron
radiation.
PMID- 10666632
TI - Crystallization and preliminary X-ray analysis of recombinant full-length human m
calpain.
AB - m-Calpain constitutes the prototype of the superfamily of neutral calcium
activated cysteine proteinases. It is a heterodimer consisting of an 80 and a 30
kDa subunit. Recombinant full-length human m-calpain has been crystallized using
macro-seeding techniques and vapour-diffusion methods. Two different monoclinic
crystal forms (space group P2(1)) were obtained from a solution containing
polyethylene glycol (M(W) = 10 000) as a precipitating agent. Complete data sets
have been collected to 2.3 and 3.0 A resolution using cryo-cooling conditions and
synchrotron radiation. The unit-cell parameters are a = 64.86, b = 133.97, c =
78.00 A, beta = 102.43 degrees and a = 51.80, b = 171.36, c = 64.66 A, beta =
94.78 degrees, respectively. The V(m) values indicate that there is one
heterodimer in each asymmetric unit.
PMID- 10666633
TI - Toxoplasma gondii adenosine kinase: expression, purification, characterization,
crystallization and preliminary crystallographic analysis.
AB - The obligate intracellular protozoan parasite Toxoplasma gondii depends on the
purine-salvage pathway for its purine supply. Unlike its mammalian hosts, T.
gondii salvages purine precursors predominantly via adenosine kinase, the enzyme
that phosphorylates adenosine to adenosine monophosphate (AMP). The cDNA encoding
T. gondii adenosine kinase was subcloned and expressed in Escherichia coli. The
recombinant protein was active in an in vitro enzyme assay over a broad pH range.
It required a divalent cation for activity. The enzyme was inactivated by the
addition of 1 microM mercuric chloride. The inactivation could be reversed by a
reducing agent. The active recombinant protein was crystallized using sodium
sulfate as precipitant at pH 8.0. The crystals diffract to 1.8 A and belong to
the monoclinic space group P2(1), with unit-cell parameters a = 47.5, b = 68.9, c
= 57.0 A, beta = 100.3 degrees. The calculated V(m) based on one molecule per
asymmetric unit is 2.38 A(3) Da(-1).
PMID- 10666634
TI - Crystallization and preliminary X-ray diffraction studies of cytochrome c6 from
Porphyra yezoensis.
AB - Cytochrome c(6) from the red alga Porphyra yezoensis has been purified and
crystallized by the sitting-drop vapour-diffusion method. Two different crystal
forms, tetragonal and orthorhombic, were obtained. The tetragonal crystals belong
to space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell dimensions a = 49.33 (2),
c = 83.70 (10) A. The orthorhombic crystals belong to space group P2(1)2(1)2(1),
with unit-cell dimensions a = 46.74 (2), b = 49.42 (1), c = 37.11 (1) A.
Absorption spectra of the crystals showed that the tetragonal form was oxidized
and the orthorhombic form was reduced.
PMID- 10666635
TI - Lactate dehydrogenase from the hyperthermophilic archaeon Methanococcus
jannaschii: overexpression, crystallization and preliminary X-ray analysis.
AB - L(+)-Lactate dehydrogenase (LDH) is a key enzyme in anaerobic metabolism which
converts pyruvate to lactate. LDH from the hyperthermophilic archaebacterium
Methanococcus jannaschii has been overexpressed in Escherichia coli and
crystallized in two crystal forms at 297 K using 2-methyl-2,4-pentanediol as
precipitant. Type I crystals grew rapidly and diffracted to at least 2.8 A Bragg
spacing upon exposure to Cu Kalpha X-rays. X-ray diffraction data to 2.9 A have
been collected from a native crystal. The type I crystal is tetragonal, belonging
to the space group P4(2)2(1)2, with unit-cell parameters a = b = 99.74, c =
170.00 A. The asymmetric unit contains two LDH subunits, with a corresponding
crystal volume per protein mass (V(m)) of 3.05 A(3) Da(-1) and a solvent content
of 59.7%. Type II crystals, which grew more slowly, diffracted to at least 1.8 A
Bragg spacing upon exposure to Cu Kalpha X-rays. X-ray diffraction data to 1.9 A
have been collected from a native crystal. The type II crystal is orthorhombic,
belonging to the space group P2(1)2(1)2, with unit-cell parameters a = 47.65, b =
125.10, c = 58.08 A. The asymmetric unit contains a single LDH subunit, with a
corresponding crystal volume per protein mass (V(m)) of 2.50 A(3) Da(-1) and a
solvent content of 50.8%. Therefore, the type II crystal is more suitable for
high-resolution structure determination than the type I crystal.
PMID- 10666636
TI - Crystallization and preliminary crystallographic studies of ribosome recycling
factor from Escherichia coli.
AB - Ribosome recycling factor (RRF) catalyzes the disassembly of a termination
complex during the final stage of protein synthesis. RRF from Escherichia coli
has been crystallized with PEG 400 as precipitant at 287 K. The crystal belongs
to the trigonal space group P3(1)21 (or P3(2)21), with unit-cell parameters a = b
= 48.08, c = 141.67 A. Native data were collected from a frozen crystal to a
resolution of 3.0 A on a Cu Kalpha rotating-anode X-ray source.
PMID- 10666637
TI - Crystallization of the NADP-dependent beta-keto acyl-carrier protein reductase
from Brassica napus.
AB - The NADP-dependent beta-keto acyl-carrier protein reductase (BKR) from Brassica
napus has been crystallized by the hanging-drop vapour-diffusion method using
polyethylene glycol of average molecular weight 1500 as the precipitant. The
crystals belong to the hexagonal space group P6(4)22, with unit-cell parameters a
= b = 129. 9, c = 93.1 A, alpha = beta = 90, gamma = 120 degrees. Calculated
values for V(m), the use of rotation and translation functions and consideration
of the packing suggest that the asymmetric unit contains a monomer. The crystals
diffract to beyond 2.8 A resolution and are more amenable to X-ray diffraction
analysis than those reported previously for the Escherichia coli enzyme. The
structure determination of B. napus BKR will provide important insights into the
catalytic mechanism of the enzyme and into the evolution of the fatty-acid
elongation cycle by comparisons with the other oxidoreductase of the pathway,
enoyl acyl-carrier protein reductase (ENR).
PMID- 10666638
TI - Crystallization and preliminary X-ray diffraction analysis of the NAD-dependent
non--phosphorylating GAPDH of the hyperthermophilic archaeon Thermoproteus tenax.
AB - Recombinant non-phosphorylating NAD(+)-dependent glyceraldehyde-3-phosphate
dehydrogenase (GAPN) of the hyperthermophilic crenarchaeote Thermoproteus tenax
has been overexpressed, purified and crystallized using the hanging-drop vapour
diffusion technique. Crystals of different habits were obtained from several
precipitant solutions (salts and polyethylene glycols). Preliminary X-ray
analysis was performed with crystals grown in ammonium formate, which belonged to
the primitive hexagonal space group P622, and had unit-cell parameters a = b =
184.8, c = 133.0 A, gamma = 120 degrees. Assuming a molecular weight of 55 kDa, a
Matthews parameter of 3.3 A(3) Da(-1) is calculated assuming two molecules per
asymmetric unit. The diffraction limit of these crystals is 2.5 A resolution.
PMID- 10666639
TI - Crystallization and preliminary X-ray analysis of the catalytic core of the
alkylhydroperoxide reductase component AhpF from Escherichia coli.
AB - Alkylhydroperoxide reductases (AhpR, E.C. 1.6.4.x) are essential for the oxygen
tolerance of aerobic organisms, converting otherwise toxic hydroperoxides of
lipids or nucleic acids to their corresponding alcohols. The AhpF component (521
amino-acid residues, 56.2 kDa) belongs to the family of pyridine nucleotide
disulfide oxidoreductases and channels electrons from NAD(P)H via a series of
disulfides towards the AhpC component, which finally reduces the hydro-peroxide
substrates. Crystals of the proteolytically truncated AhpF component (residues
Asn208-Ala521) of the alkyl hydroperoxide reductase from Escherichia coli were
grown under oxidizing conditions. The crystals belong to space group P3(2)21,
with unit-cell parameters a = 60.4, c = 171.8 A. X-ray diffraction data were
collected to 1.9 A resolution using synchrotron radiation. A molecular
replacement solution was found using the structure of thioredoxin reductase from
Arabidopsis thaliana as a search model.
PMID- 10666640
TI - Crystallization and preliminary X-ray analysis of a bacteriophage T4 primase
fragment.
AB - The primase from bacteriophage T4 is a single-stranded DNA-dependent RNA
polymerase that is one of the seven proteins that constitute the DNA-replication
machinery of bacteriophage T4. In an attempt to crystallize the protein, a number
of variants were generated. One such construct, which includes the C-terminal
region (residues 196-340), gave four different crystal forms which diffract in
the 3. 5-6.0 A resolution range.
PMID- 10666641
TI - Preliminary X-ray crystallographic analysis of a plant defence protein, the
polygalacturonase-inhibiting protein from Phaseolus vulgaris.
AB - A leucine-rich repeat plant protein involved in resistance to pathogens, a
polygalacturonase-inhibiting protein (PGIP-1) from Phaseolus vulgaris, has been
crystallized and preliminary X-ray characterization has been performed. The
protein contains ten repeats of a short (24 amino-acid) leucine-rich repeat
motif. Single crystals of the protein were grown from vapour-diffusion
experiments using PEG 2K monomethylether as precipitant; these crystals diffract
to at least 2.3 A resolution. The space group is P2(1), with two molecules of
PGIP-1 in the asymmetric unit; the crystals contain approximately 38% solvent.
PMID- 10666642
TI - Crystallization of type I chloramphenicol acetyltransferase: an approach based on
the concept of ionic strength reducers.
AB - Chloramphenicol acetyltransferase (CAT) is responsible for bacterial resistance
to chloramphenicol. It catalyzes inactivation of the antibiotic by acetyl-group
transfer from acetyl CoA to one or both hydroxyl groups of chloramphenicol. Type
I CAT possesses some unique properties which are not observed in other CAT
variants. Type I CAT overexpressed in Escherichia coli was purified and crystals
with a resolution limit of 2.22 A have been obtained using a novel procedure
which is based on the concept of 'ionic strength reducers'. The crystals have the
symmetry of space group P1 and unit-cell parameters a = 96.46, b = 113.86, c =
114.21 A, alpha = 119.9, beta = 94.1, gamma = 98.6 degrees. These dimensions are
consistent with four to six trimers per unit cell, corresponding to a solvent
fraction ranging from 65 to 47%.
PMID- 10666643
TI - Crystallization and preliminary crystallographic study of triple-helical DNA.
AB - Single crystals of d(CTCCT(S)CCGCGCG).d(CGCGCGGAG) have been grown by the vapor
diffusion method using 2-methyl-2,4-pentanediol as a precipitant. The crystals
are tetragonal, space group P4(2), with unit-cell parameters a = b = 53.8, c =
43.1 A, and diffract to 1.8 A resolution at a synchrotron X-ray beamline. In the
crystal, the asymmetric unit contains one copy of the construct. The two halves
of the structure are related by non-crystallographic twofold symmetry. These
observations are consistent with the conclusion that the sequences of the 12-mer
and 9-mer oligonucleotides form a duplex DNA at one end and a triplex DNA at the
other end.
PMID- 10666644
TI - Optimization of the critical nuclear size for protein crystallization: a note.
AB - It was observed that for some proteins the best crystals for X-ray diffraction
have been obtained at supersaturation ratios of ca 2.5-3 (in experiments without
seeding). It was then noticed that under certain conditions specific to the
protein such values are close to a local minimum of the critical radius for
nucleation. A relation between the two observations is proposed.
PMID- 10666645
TI - Experiences and expectations of a novel X-ray microsource with focusing mirror.
I. erratum
AB - The following are corrections to a paper by Bloomer & Arndt [(1999), Acta Cryst.
D55, 1672-1680]. The entry in the second row of the I(MAR) column of Table 1(b)
on page 1674 should read 6.6 and not 16. 6. In Table 4 on page 1677 the source
diameter should be given as 15 &mgr;m and not 15 mm, and the units for the
diameter of the sample should be given as &mgr;m instead of mm.
PMID- 10666647
TI - Notes for authors
PMID- 10666646
TI - Crystallization of helix pomatia agglutinin (HPA), a protein from the edible
snail. erratum
AB - One of the authors was omitted in the published version of the paper by Lisgarten
et al. (1999) Acta Cryst. D55, 1903-1905. The full author list is given above.
PMID- 10666648
TI - The role of human bone morphogenetic proteins in spinal fusion.
AB - The attainment of a stable arthrodesis is critical to the successful management
of some types of spinal disorders. Autologous iliac-crest bone graft has been the
most commonly utilized substance associated with predictable healing in spinal
fusion applications. Although alternative graft substances exist, these have not
been shown to be as uniformly effective in achieving spinal fusion. Because of
the morbidity associated with bone autograft harvest, there is increasing
interest in alternative graft substances and especially in the osteoinductive
abilities of bone morphogenetic proteins (BMPs). Several animal models have
demonstrated that BMP-containing allograft or synthetic carrier medium is as
effective as or superior to autograft bone in promoting spinal fusion.
Furthermore, the limited number of human trials utilizing BMPs to treat nonunions
in the appendicular skeleton indicate that the results found in animal models
will be reproducible in the clinical setting.
PMID- 10666649
TI - Orthopaedic aspects of child abuse.
AB - Increased awareness of child abuse has led to better understanding of this
complex problem. However, the annual incidence of abuse is estimated at 15 to 42
cases per 1,000 children and appears to be increasing. More than 1 million
children each year are the victims of substantiated abuse or neglect, and more
than 1,200 children die each year as a result of abuse. The diagnosis of child
abuse is seldom easy to make and requires a careful consideration of
sociobehavioral factors and clinical findings. Because manifestations of physical
abuse involve the entire child, a thorough history and a complete examination are
essential. Fractures are the second most common presentation of physical abuse
after skin lesions, and approximately one third of abused children will
eventually be seen by an orthopaedic surgeon. Thus, it is essential that the
orthopaedist have an understanding of the manifestations of physical abuse, to
increase the likelihood of recognition and appropriate management. There is no
pathognomonic fracture pattern in abuse. Rather, the age of the child, the
overall injury pattern, the stated mechanism of injury, and pertinent
psychosocial factors must all be considered in each case. Musculoskeletal injury
patterns suggestive of nonaccidental injury include certain metaphyseal lesions
in young children, multiple fractures in various stages of healing, posterior rib
fractures, and long-bone fractures in children less than 2 years old. Skeletal
surveys and bone scintigraphy with follow-up radiography may be of benefit in
cases of suspected abuse of younger children. The differential diagnosis of abuse
includes other conditions that may cause fractures, such as true accidental
injury, osteogenesis imperfecta, and metabolic bone disease. Management should be
multidisciplinary, with the key being recognition, because abused children have a
substantial risk of repeated abuse and death.
PMID- 10666650
TI - Ballistics and gunshot wounds: effects on musculoskeletal tissues.
AB - As a result of the increasing number of weapons in this country, as many as
500,000 missile wounds occur annually, resulting in 50,000 deaths, significant
morbidity, and striking socioeconomic costs. Wounds are generally classified as
low-velocity (less than 2,000 ft/sec) or high-velocity (more than 2,000 ft/sec).
However, these terms can be misleading; more important than velocity is the
efficiency of energy transfer, which is dependent on the physical characteristics
of the projectile, as well as kinetic energy, stability, entrance profile and
path traveled through the body, and the biologic characteristics of the tissues
injured. Although bullets are not sterilized on discharge, most low-velocity
gunshot wounds can be safely treated nonoperatively with local wound care and
outpatient management. Typically, associated fractures are treated according to
accepted protocols for each area of injury. Treatment of low-velocity, low-energy
fractures is generally dictated by the osseous injuries, as these are similar in
many regards to closed fractures. Soft tissues play a more critical role in high
velocity and shotgun fractures, which are essentially open injuries. Aside from
perioperative prophylaxis, antibiotics are probably required only for grossly
contaminated wounds; however, because contamination is not always apparent, most
authors still recommend routine prophylaxis. High-energy injuries and grossly
contaminated wounds mandate aggressive irrigation and debridement, including a
thorough search for foreign material. Open fracture protocols including external
fixation or intramedullary nailing and intravenous antibiotic therapy for 48 to
72 hours should be instituted. If there is vascular damage, exploration and
repair are best performed after prompt fracture stabilization. Evaluation of the
"four Cs"-color, consistency, contractility, and capacity to bleed-provides
valuable information regarding the viability of muscle. Skin grafting is
preferable when tension is required for wound closure, although other soft-tissue
procedures, such as use of local rotation flaps or free tissue transfer, may be
necessary, especially for shotgun wounds. Distal neurologic deficit alone is not
an indication for exploration, as it often resolves without surgical
intervention.
PMID- 10666651
TI - Aging successfully: the importance of physical activity in maintaining health and
function.
AB - Physicians caring for middle-aged and older patients frequently overlook the
importance of regular physical activity. Exercise on a routine basis is an
important component of successful aging. It has been shown that many age-related
declines in musculoskeletal function can be markedly reduced by participation in
some form of regular exercise. Examination of records from masters athletic
competitions has been used to determine the true rate of age-related functional
declines in highly trained, healthy individuals and further supports these
findings. Declines in physical abilities for masters athletes are gradual, which
suggests that for many, the potential for participation in competitive athletics
can persist well into the seventh decade of life. Recent studies indicate that
health gains can be achieved with relatively low volumes of exercise. Indeed, the
greatest benefit is seen when one "goes from doing nothing to doing something."
Current data suggest that a cumulative total of 30 to 50 minutes of aerobic
exercise a day performed 3 to 5 days a week and one set of resistance exercises
targeting the major muscle groups twice a week can produce significant health
benefits. The aerobic conditioning requirement need not be a formal or structured
activity, but can be satisfied through regular participation in many common
physical tasks (e.g., walking, gardening, housekeeping). Musculoskeletal injuries
are a major cause of noncompliance with any exercise regimen and are especially
debilitating for older individuals. Prompt recognition of injury and treatment
that emphasizes alternative conditioning exercises and minimizes "downtime" are
especially important. Orthopaedists should be aware of the pattern of
musculoskeletal injuries seen in this population, so as to assist their patients
in avoiding these problems.
PMID- 10666652
TI - Evaluation of chronic wrist pain.
AB - Chronic wrist pain remains a challenge to diagnose and treat. A thorough history
and physical examination are key. Various imaging techniques are essential to the
evaluation of the patient with chronic wrist pain. Standard radiography, computed
tomography, cinearthrography, magnetic resonance imaging, radionuclide imaging,
arthroscopy, and arteriography all may have a role in assessment, and the
orthopaedic surgeon should be familiar with the indications, strengths, and
weaknesses of each. Laboratory tests may also be useful in evaluation. No all
inclusive algorithm can be applied in this setting; therefore, the physician must
rely on his or her diagnostic acumen to successfully assess and treat chronic
wrist pain.
PMID- 10666653
TI - Surgical treatment of metastatic disease of the femur.
AB - Nearly every malignant neoplasm has been described as having the capability to
metastasize to bone. Of the estimated 1.2 million new cases of cancer diagnosed
annually, more than 50% will eventually demonstrate skeletal metastasis. Advances
in systemic and radiation therapy have led to a considerable improvement in the
prognosis of patients with metastatic disease. As a result, orthopaedic surgeons
are being asked with increasing frequency to evaluate and treat the
manifestations of skeletal metastases. The femur is commonly the site of large
impending lesions and complete pathologic fractures. Although the health status
of some patients may preclude operative intervention, established pathologic
fractures of the femur and metastatic lesions deemed likely to progress to
imminent fracture generally should be treated surgically. A rational approach to
selection of the proper treatment for these problems includes consideration of
the patient's overall medical condition and the type, location, size, and extent
of the tumor. Treatment principles are the same regardless of location. A
construct should ideally provide enough stability to allow immediate full weight
bearing with enough durability to last the patient's expected lifetime. All areas
of weakened bone should be addressed at the time of surgery in anticipation of
disease progression. To minimize disease progression and possible implant or
internal fixation failure, postoperative external-beam irradiation should be
considered.
PMID- 10666654
TI - Perioperative lower urinary tract infections and deep sepsis in patients
undergoing total joint arthroplasty.
AB - Deep sepsis in the involved joint after hip or knee arthroplasty may be the
result of hematogenous seeding from a remote infectious source. This mechanism
has been used to explain the well-documented association between postoperative
urinary tract infections and subsequent joint infection after hip or knee
arthroplasty. However, it is unclear whether there is an association between
preoperative bacteriuria and deep prosthetic infection. The purpose of this
review is to identify perioperative risk factors associated with bacteriuria that
have a positive correlation with deep joint sepsis following total hip or knee
arthroplasty. The classic symptoms of dysuria, urgency, and frequency seen with
urinary tract infections are often absent in the elderly despite the presence of
urine coliforms; in these patients, pyuria (as indicated by the presence of more
than 1x10(3) white blood cells per milliliter of noncentrifuged urine) may be
used as a preliminary screening criterion. If there are irritative symptoms, the
presence of more than 1x10(3) bacteria per milliliter of urine should be regarded
as indicative of a urinary tract infection. If there is bacteriuria without
symptoms of urinary irritation or obstruction, the current literature supports
proceeding with total joint arthroplasty and treating those patients with urine
colony counts greater than 1x10(3)/mL with an 8- to 10-day postoperative course
of an appropriate oral antibiotic. Postponement of total joint surgery should be
considered if preoperative evaluation reveals symptoms related to obstruction of
the urinary pathway. Irritative symptoms in combination with a bacterial count
greater than 1x10(3)/mL should also serve as an indication to postpone surgery.
To diminish postoperative urinary tract infection, a bladder catheter should be
inserted immediately preoperatively and removed within 24 hours of surgery to
diminish the risk of urinary retention, which has been shown to increase the
likelihood of a postoperative urinary tract infection.
PMID- 10666655
TI - Arrhythmic risk stratification of post-myocardial infarction patients.
AB - Post-myocardial infarction risk stratification, especially arrhythmic risk
stratification, is an issue that has still not been wholly addressed in modern
clinical cardiology. In the past 10 years, arrhythmic risk stratification has
been approached mainly by evaluating frequency and complexity of premature
ventricular contractions, detected on Holter monitoring, often in association
with determination of percent ejection fraction. This methodology has been proven
to be limited and fallacious according to the Cardiac Arrhythmia Suppression
Trial I and II (CAST I,II) results, in which suppression of premature ventricular
contractions or premature ventricular beats throughout by antiarrhythmic drugs
resulted in an increase in both cardiac and arrhythmic mortality. Only amiodarone
as an antiarrhythmic drug, as proven in the recent European Myocardial Infarct
Amiodarone Trial (EMIAT) and Canadian Amiodarone Myocardial Infarction Trial
(CAMIAT), was effective in reducing arrhythmic mortality without affecting
cardiac mortality, in patients selected mainly because of a reduced ejection
fraction, with and without premature ventricular contractions. Conversely, it is
well known that beta-blockers are effective in preventing sudden death in post
acute myocardial infarction (AMI) patients, thus reducing cardiac and arrhythmic
mortality. Conversely, in other institutions, risk stratification in post-AMI
patients has been performed by electrophysiologic study obtained, without any
previous noninvasive arrhythmic risk stratification, in all post-AMI patients. In
recent years, many other noninvasive electrocardiology parameters, such as late
potentials (signal-averaged electrocardiography), heart rate variability,
baroreflex sensitivity, and, more recently, T-wave alternance, have been shown to
be useful, but they are associated with a low specificity in the noninvasive
identification of patients at high risk for arrhythmic mortality. Conversely, in
the Multicenter Automatic Defibrillation Implantation Trial (MADIT),
electrophysiology confirmed that inducibility of ventricular tachycardia shows
high specificity and a high predictive value for arrhythmic events. Nevertheless,
the MADIT study population is not comparable to a cohort of consecutive patients
who have recently had a myocardial infarction. In this setting, the highest risk
of arrhythmic events can be observed in patients with depressed percent ejection
fraction (< 35%) and in the first 6 months after AMI. Today, the most convincing
approach seems to be the one combining both noninvasive risk stratification
parameters (e.g., premature ventricular beats > 10/h or reduced heart rate
variability < 70 ms or a positive signal-averaged electrocardiogram) followed by
a further arrhythmic risk stratification, obtained through electrophysiologic
study. Several published and ongoing trials that utilize various arrhythmic risk
stratification techniques as part of their protocol are reviewed.
PMID- 10666656
TI - Inpatient versus outpatient antiarrhythmic drug initiation: safety and cost
effectiveness issues.
AB - Debate exists as to the proper site for initiating antiarrhythmic therapy for
supraventricular tachyarrhythmias and other benign forms of ectopy: inpatient
versus outpatient. Rapid detection of efficacy and adverse effects, with
immediate correction of the latter, favors the inpatient site. Convenience and,
under most circumstances, lower cost favor the outpatient site. Circumstances
under which adverse event rates, including proarrhythmia, are expectedly low,
would favor outpatient initiation. So would the use of an agent whose elimination
half-life is so long as to render in-hospital monitoring to steady state highly
impractical. Accordingly, outpatient initiation would be suitable for patients
without structural heart disease receiving class IC drugs, patients with low risk
for torsades de pointes receiving selected class III agents, in whom data in the
literature are supportive (as has occurred with sotalol and azimilide), and
patients who are to receive amiodarone. Transtelephonic electrocardiographic
monitoring can be used to facilitate assessment in the outpatient setting.
Inpatient initiation should be considered for patients with underlying sinus node
or atrioventricular conduction disturbances, for patients with significant
structural heart disease, for patients receiving a drug whose proarrhythmia may
be idiosyncratic (e.g., quinidine), and for patients who are to begin an
antiarrhythmic drug while in a supraventricular tachyarrhythmia in whom sinus
rhythm has not previously been seen. The relative costs and benefits of the
approach chosen will be a reflection of the probability that a drug with a chosen
mechanism will cause an adverse outcome in a patient with a specific clinical
substrate during the period chosen for monitoring.
PMID- 10666657
TI - Molecular biology of arrhythmic syndromes.
AB - In this review, the up-to-date understanding of the molecular basis of primary
ventricular arrhythmias will be outlined. Two disorders have recently been well
described at the molecular level, the long QT syndromes and Brugada syndrome, and
in this paper we review the current scientific knowledge of each disease.
PMID- 10666658
TI - Cost-effective strategies in the acute management of atrial fibrillation.
AB - Atrial fibrillation is the most common sustained arrhythmia likely to be
encountered in clinical practice. It is associated with significant morbidity and
mortality. The treatment of patients with atrial fibrillation can be complex and
costly, especially when patients are hospitalized for acute management of this
arrhythmia. In this review, we summarize current approaches to the acute
management of atrial fibrillation with an emphasis on the most cost-effective
approaches. We review acute methods of heart rate control and cardioversion,
including pharmacologic and other minimally invasive strategies. We believe that
the most cost-effective approaches may require the use of standardized clinical
pathways. This may help to ensure that patients with acute atrial fibrillation
receive the most effective and efficient care.
PMID- 10666659
TI - Catheter ablation in the year 2000.
AB - After its introduction in 1987, radiofrequency catheter ablation became
established as a safe and effective therapy for the cure of many cardiac
arrhythmias in people. The possibility of assessing the relationship between the
anatomical target and the electrophysiologic changes produced by radiofrequency
pulse delivery has also provided significant improvement in the physician's
knowledge of the pathophysiology of the underlying rhythm disturbance. Nowadays,
using this therapy, success rates well above 90% with recurrence rates lower than
5% are expected after treatment of most regular supraventricular arrhythmias. As
catheter ablation techniques develop, success rates in the range of those
obtained for regular supraventricular arrhythmias are expected in the future in
the treatment of regular ventricular and irregular supraventricular arrhythmias.
PMID- 10666660
TI - New advances in class III antiarrhythmic drug therapy.
AB - In the past 2 years, significant advances have been made in class III
antiarrhythmic drug therapy. In patients with ventricular arrhythmias and
implantable cardioverter defibrillators (ICDs), antiarrhythmic agents are
increasingly being used as adjunct therapy to decrease the frequency of ICD
discharges. Sotalol was recently shown to be effective in reducing
tachyarrhythmias in patients with ICDs. Intravenous amiodarone is being used for
the acute treatment of unstable ventricular arrhythmia and is being investigated
for the treatment of acute out-of-hospital cardiac arrest. Class III agents are
increasingly being used for prophylaxis in patients who have atrial fibrillation
or atrial flutter, and data point to an important role for these agents in
reducing supraventricular tachyarrhythmias after cardiac surgery. Future studies
will need to directly compare these agents with pure anti-adrenergic maneuvers in
postoperative patients. In addition to terminating atrial fibrillation and atrial
flutter, ibutilide significantly reduces human atrial defibrillation thresholds
and increases the percentage of patients who can be cardioverted from atrial
fibrillation to sinus rhythm. The US Food and Drug Administration is expected to
approve dofetilide for clinical use soon, and it is currently reviewing azimilide
(which seems to be devoid of frequency-dependent effects on repolarization) for
prophylaxis against atrial fibrillation and atrial flutter. Dronedarone,
tedisamal, and trecetilide are now under active study intended to determine their
usefulness in patients with cardiac arrhythmias. Experimental studies are ongoing
to identify pharmacologic agents that will selectively prolong repolarization in
the atria without exerting electrophysiologic effects in the ventricles.
PMID- 10666661
TI - Classification system of atrial fibrillation.
AB - A number of publications and clinical trials on the management of atrial
fibrillation (AF) deal with this arrhythmia as if it represents a single entity.
As a result, advances made in recent years have not affected the way AF patients
are treated in general practice except, perhaps, for the use of warfarin in
anticoagulation. Therefore, there is a need for a classification system and for
uniformity in the nomenclature used. The two terms currently used to describe AF,
paroxysmal and chronic, require a time frame. It is proposed that if an AF
episode lasts longer than 7 days, the condition should be considered chronic. For
the first symptomatic, non-self-terminating episode that is fewer than 7 days
long, the term recent onset AF may be used, or recent discovery if the AF is
asymptomatic or if the duration cannot be determined. Attacks of paroxysmal AF
may differ in their duration, frequency, and functional tolerance. In the
classification system described, three clinical aspects of paroxysmal AF were
isolated in such a way as to have implications for therapy. This classification
system was found to be useful for characterizing different subsets of patients
with AF.
PMID- 10666662
TI - Clinical implication of antiembolic trials in atrial fibrillation and role of
transesophageal echocardiography in atrial fibrillation.
AB - Risk for stroke in patients with atrial fibrillation (AF) is highly
heterogeneous. Increasing age, history of diabetes, hypertension, previous
transient ischemic attack or stroke, and poor ventricular function are
independent risk factors for stroke in patients with AF. Accordingly, some groups
of patients with AF have low risk and some have high risk. In general, patients
at high risk benefit most from anticoagulation therapy with warfarin. In general,
if a patient is younger than 65 years of age and has none of the defined risk
factors, the stroke rate without prophylaxis (aspirin or warfarin) is low. In
patients 65 to 75 years of age with no risk factors, the risk for stroke is low
with either aspirin or warfarin therapy; the choice is left to the caretaking
physician. All patients older than 75 years and all patients of any age who have
risk factors obtain striking benefit from the use of anticoagulation with
warfarin. This benefit far outweighs any risk for major hemorrhage.
PMID- 10666663
TI - Amiodarone: clinical trials.
AB - Amiodarone is an antiarrhythmic agent commonly used in the treatment of
supraventricular and ventricular tachyarrhythmias. This article reviews the
results and clinical implications of primary and secondary prevention trials in
which amiodarone was used in one of the treatment arms. Key post-myocardial
infarction primary prevention trials include the European Myocardial Infarct
Amiodarone Trial (EMIAT) and the Canadian Amiodarone Myocardial Infarction Trial
(CAMIAT), both of which demonstrated that amiodarone reduced arrhythmic but not
overall mortality. In congestive heart failure patients, amiodarone was studied
as a primary prevention strategy in two pivotal trials: Grupo de Estudio de la
Sobrevida en la Insuficiencia Cardiac en Argentina (GESICA) and Amiodarone in
Patients With Congestive Heart Failure and Asymptomatic Ventricular Arrhythmia
(CHF-STAT). Amiodarone was associated with a neutral overall survival and a trend
toward improved survival in nonischemic cardiomyopathy patients in CHF/STAT and
improved survival in GESICA. In post-myocardial infarction patients with
nonsustained ventricular tachycardia and a depressed ejection fraction, the
Multicenter Automatic Defibrillator Implantation Trial (MADIT) demonstrated that
implantable cardioverter-defibrillators (ICD) statistically improved survival
compared to the antiarrhythmic drug arm, most of whose patients were taking
amiodarone. In patients with histories of sustained ventricular tachycardia or
ventricular fibrillation, the Cardiac Arrest Study in Seattle: Conventional
Versus Amiodarone Drug Evaluation (CASCADE) trial demonstrated that empiric
amiodarone lowered arrhythmic recurrence rates compared to other drugs guided by
serial Holter or electrophysiologic studies. However, arrhythmic death rates were
high in both treatment arms of the study. Several secondary prevention trials,
including the Antiarrhythmics Versus Implantable Defibrillators Study (AVID), the
Canadian Implantable Defibrillator Study (CIDS), and the Cardiac Arrest Study
Hamburg (CASH), have demonstrated the superiority of ICD therapy compared to
empiric amiodarone in improving overall survival. Based on the above findings,
amiodarone is safe to use in post-myocardial infarction and congestive heart
failure patients that need antiarrhythmic therapy. Although amiodarone is
effective in treating malignant arrhythmias, high-risk patients should be
considered for an ICD as frontline therapy.
PMID- 10666664
TI - Bibliography. Current world literature. Arrhythmias.
PMID- 10666665
TI - Molecular abnormalities of the brain in Down syndrome: relevance to Alzheimer's
neurodegeneration.
AB - Down syndrome is caused by over-expression of genes located within a segment of
chromosome 21, termed the Down locus. Down syndrome is associated with
developmental abnormalities of the central nervous system that result in mental
retardation and age-dependent Alzheimer-type neurodegeneration. Some of the
neurodegenerative lesions, including A beta amyloid deposition, apoptotic cell
death, and aberrant dendritic arborization, are in part due to constitutively
increased expression of genes that encode the amyloid precursor protein,
superoxide dismutase I, and S100-beta, and located within the Down locus.
However, neurodegeneration in Down syndrome is also associated with aberrant
expression of genes that are not linked to the Down locus, including the growth
associated protein, GAP-43, nitric oxide synthase 3, neuronal thread protein, and
pro-apoptosis genes such as p53, Bax, and interleukin-1 beta-converting enzyme.
Increased expression of these non-Down locus genes correlates with proliferation
of dystrophic neurites and apoptotic cell death, two important correlates of
cognitive impairment in Alzheimer's disease. This article reviews the functional
importance of abnormal gene expression in relation to Alzheimer-type
neurodegeneration in brains of individuals with Down syndrome.
PMID- 10666667
TI - The Down syndrome critical region.
AB - Since the early 1970's numerous attempts have been made to learn whether specific
segments of chromosome 21, when triplicated, are responsible for the clinical
condition Down syndrome (DS). Studies were reported in which positive or negative
clinical diagnoses of DS were made in the presence of partial trisomy of one or
another segment of the chromosome. The distal half of the long arm of 21 (21q22)
possesses most of the gene transcribing sites of the chromosome. It was this
region that was thought to contain loci essential to production of the clinical
syndrome. Subsequent studies identified subregions of this band as "minimal" or
"critical" sites necessary and sufficient to produce the clinical condition. A
major problem with these assignments was that different investigators defined
different critical/minimal regions. In 1994 evidence was presented in which
regions of most of the long arm of chromosome 21 were said to contribute to the
DS phenotype. Soon after, a report described a child with DS and partial
tetrasomy of the short arm and proximal long arm of 21, segments clearly distinct
from the previously identified critical areas. Thus the clinical diagnosis of DS
can be made in the presence of partial aneuploidy of nearly all segments of
chromosome 21. It must be concluded that no evidence exists that individual loci
on 21 are singularly responsible for specific phenotypic abnormalities in DS.
Without exception, each of the clinical findings associated with DS is a
multifactorial trait. The analysis of each trait in DS should thus be similar to
analyses of the same traits in the general population with a focus on the way
aneuploidy affects expression of multifactorial characteristics.
PMID- 10666666
TI - Reduced aldehyde dehydrogenase levels in the brain of patients with Down
syndrome.
AB - Aldehyde dehydrogenase (ALDH) is a key enzyme in fructose, acetaldehyde and
oxalate metabolism and represents a major detoxification system for reactive
carbonyls and aldehydes. In the brain, ALDH exerts a major function in the
metabolism of biogenic aldehydes, norepinephrine, dopamine and diamines and gamma
aminobutyric acid. Subtractive hybridization studies in Down Syndrome (DS) fetal
brain showed that mRNA for ALDH are downregulated. Here we studied the protein
levels in the brain of adult patients. The proteins from five brain regions of 9
aged patients with DS and 9 controls were analyzed by two-dimensional (2-D) gel
electrophoresis and identified by matrix-assisted laser desorption ionization
mass spectrometry. ALDH levels were reduced in the brain regions of at least half
of the patients with Down Syndrome, as compared to controls. The decreased ALDH
levels in the DS brain may result in accumulation of aldehydes which can lead to
the formation of plaques and tangles reflecting abnormally cross-linked,
insoluble and modified proteins, found in aged DS brain. Furthermore, we
constructed a 2-Dmap including approximately 120 identified human brain proteins.
PMID- 10666668
TI - Neuropathology.
PMID- 10666669
TI - c-fos expression in brains of patients with Down syndrome.
AB - c-fos is a protooncogene serving in multiple physiological processes in brain
from signalling to proliferation and synaptic plasticity. We therefore decided to
determine this transcription factor in control and Down Syndrome (DS) brain with
the Rationale that c-fos may be linked to brain damage in DS. We determined mRNA
steady state levels in frontal, parietal, occipital, temporal cortex and
cerebellum of 9 patients with DS and 9 controls using RT-PCT. Significantly
increased levels of mRNA c-fos normalized versus the housekeeping gene beta-actin
mRNA were found in frontal, parietal and temporal cortex of DS brain. c-fox mRNA
levels comparable to controls were found in occipital cortex and cerebellum.
Deteriorated c-fos expression in the individual brain regions may be linked to
increased apoptosis and neurodegeneration, overexcitation by excitatory amino
acids of reactive oxygen species.
PMID- 10666670
TI - Neuronal cell death in Down's syndrome.
AB - Down's syndrome (DS), occurring in 0.8 out of 1,000 live births, is a genetic
disorder in which an extra portion of chromosome 21 leads to several
abnormalities. With respect to the nervous system, it causes mental retardation.
It is conceived that abnormal neuronal cell death in development is involved, but
there is no direct evidence yet. In addition to developmental brain
abnormalities, almost all DS brains over 40 years old manifest a similar
pathology to Alzheimer's disease (AD), including the presence of senile plaques
(SP) and neurofibrillary tangles (NFT). Although there was a debate to segregate
dementia from underlying mental retardation, at least some portion of DS patients
exhibit deteriorated mental status with aging. The mechanism underlying these
abnormalities at the molecular level remains to be elucidated. Recently there
have been several reports suggesting abnormalities reflecting increased risk to
apoptosis in DS brains. Increased expression of several apoptosis-related genes
(p53, fas, ratio of bax to bcl-2, GAPDH) in DS brains has been reported. Cultured
neurons from both patients and model animals are reportedly more vulnerable to
apoptosis. Overproduction of reactive oxygen species and its causative roles for
increased apoptosis in DS tissues are suggested. One possible hypothesis is an
increased susceptibility to apoptosis due to p53 overactivation in DS brains. A
beta 42, a critical peptide for AD pathology from amyloid precursor protein
(APP), can be detected in DS brains. A beta 42 is deposited in SP from an early
stage, suggesting common molecular mechanisms in DS and AD. Animal models for DS
are important in the search of molecular mechanisms. Several types of models are
now available. Future DS studies are expected to integrate information from
animal models and human tissues.
PMID- 10666671
TI - Altered gene expression in fetal Down syndrome brain as revealed by the gene
hunting technique of subtractive hybridization.
AB - Information on gene expression in brain of patients with Down Syndrome (DS,
trisomy 21) is limited and molecular biological research is focussing on mapping
and sequencing chromosome 21. The information on gene expression in DS available
follows the current concept of a gene dosage effect due to a third copy of
chromosome 21 claiming overexpression of genes encoded on this chromosome. Based
upon the availability of fetal brain and recent technology of gene hunting, we
decided to use subtractive hybridization to evaluate differences in gene
expression between DS and control brains. Subtractive hybridization was applied
on two fetal brains with DS and two age and sex matched controls, 23rd week of
gestation, and mRNA steady state levels were evaluated generating a subtractive
library. Subtracted sequences were identified by gene bank and assigned by
alignments to individual genes. We found a series of up- and downregulated
sequences consisting of chromosomal transcripts, enzymes of intermediary
metabolism, hormones, transporters/channels and transcription factors (TFs). We
show that trisomy 21 or aneuploidy leads to the deterioration of gene expression
and the derangement of transcripts describes the impairment of transport,
carriers, channels, signaling, known metabolic and hormone imbalances. The dys
coordinated expression of transcription factors including homeobox genes, POU
domain TFs, helix-loop-helix-motifs, LIM domain containing TFs, leucine zippers,
forkhead genes, maybe of pathophysiological significance for abnormal brain
development and wiring found in patients with DS. This is the first description
of the concomitant expression of a large series of sequences indicating
disruption of the concerted action of genes in this disorder.
PMID- 10666672
TI - Gene expression in fetal Down syndrome brain as revealed by subtractive
hybridization.
AB - Information on gene expression in brain of patients with Down Syndrome (DS,
trisomy 21) is limited and molecular biological research is focussing on mapping
and sequencing chromosome 21. The information on gene expression in DS available
follows the current concept of a gene dosage effect due to a third copy of
chromosome 21 claiming overexpression of genes encoded on this chromosome. Based
upon the availability of fetal brain and recent technology of gene hunting, we
decided to use subtractive hybridization to evaluate differences in gene
expression between DS and control brains. Subtractive hybridization was applied
on two fetal brains with DS and two age and sex matched controls, 23rd week of
gestation, and mRNA steady state levels were evaluated generating a subtractive
library. Subtracted sequences were identified by gene bank and assigned by
alignments to individual genes. We found a series of up- and downregulated
sequences consisting of chromosomal transcripts, enzymes of intermediary
metabolism, hormones, transporters/channels and transcription factors (TFs). We
show that trisomy 21 or aneuploidy leads to the deterioration of gene expression
and the derangement of transcripts described describes the involvement of
chromosomes other than chromosome 21, explains impairment of transport, carriers,
channels, signaling, known metabolic and hormones imbalances. The dys-coordinated
expression of transcription factors including homeobox genes, POU-domain TFs,
helix-loop-helix-motifs, LIM domain containing TFs, leucine zippers, forkhead
genes, maybe of pathophysiological significance for abnormal brain development
and wiring found in patients with DS. This is the first description of the
concomitant expression of a large series of sequences indicating disruption of
the concerted action of genes in that disorder.
PMID- 10666673
TI - Molecular misreading of genes in Down syndrome as a model for the Alzheimer type
of neurodegeneration.
AB - The occurrence of +1 frameshifted proteins, such as amyloid precursor protein
(APP+1) and ubiquitin-B (UBB+1) in Down syndrome (DS) has been linked to the
onset of Alzheimer's disease (AD). In DS and AD patients, but also in elderly non
demented persons, these co-called +1 proteins accumulate in the neuropathological
hallmarks (neurofibrillary tangles, dystrophic neurites of the neuritic plaques
and neuropil threads) and may have deleterious effects on neuronal function.
Frameshifts are caused by dinucleotide deletions in GAGAG motifs in messenger RNA
and are now thought to be the result of unfaithful transcription of normal DNA by
a novel process termed "molecular misreading". In the present review some of the
critical events in molecular misreading are discussed, the emphasis being on DS.
PMID- 10666674
TI - Expression of the dihydropyrimidinase related protein 2 (DRP-2) in Down syndrome
and Alzheimer's disease brain is downregulated at the mRNA and dysregulated at
the protein level.
AB - Deteriorated migration, axonal pathfinding and wiring of the brain is a main
neuropathological feature of Down Syndrome (DS). Information on the underlying
mechanisms is still limited, although basic functions of a series of growth
factors, cell adhesion molecules, guidance factors and chemoattractants for brain
histogenesis have been reported. We used proteomics to detect differences in
protein expression between control, DS and Alzheimer's disease brains: In five
individual brain regions of 9 individuals of each group we performed two
dimensional electrophoresis with MALDI--identification of proteins and determined
mRNA levels of DRP-2. Significantly decreased mRNA levels of DRP-2 in four brain
regions of patients with DS but not with AD as compared to controls were
detected. 2D electrophoresis revealed variable expression of DRP-2 proteins,
which showed a high heterogeneity per se. Dysregulation of DRP-2 was found in
brains of patients with DS and AD presenting with an inconsistent pattern, which
in turn may reflect the inconsistent neuropathological findings in patients with
DS and AD. The decrease of mRNA DRP-2 steady state levels in DS along with
deteriorated protein expression of this repulsive guidance molecule of the
semaphorin/collapsin family, may help to explain deranged migration and
histogenesis of DS brain and wiring of AD brain.
PMID- 10666675
TI - Gene expression relevant to Down syndrome: problems and approaches.
AB - The long arm of human chromosome 21 likely contains several hundred genes. To
determine which of these are responsible for specific aspects of the Down
Syndrome phenotype, protein functional analysis coupled to phenotypic analysis of
transgenic mice will be required. Because such experiments are both time
consuming and expensive, prioritizing 21q genes for further studies would be
advantageous. Here, we discuss expression analysis, specifically the use of
Northern analysis, cDNA array screening and RNA tissue in situ hybridization to
assess place and time of expression of forty-two genes. For a subset of these,
over expression in normal versus trisomy cell lines and mouse tissues is
discussed. Lastly, several examples of alternative processing and their potential
for generation of brain specific proteins are described. Together, these
experiments give information on time, place and level of expression of a number
of 21q genes and suggest some interesting candidates worth further investigation
for relevance to Down Syndrome. These data also illustrate the complexities and
ambiguities inherent in interpretation and use of expression information.
PMID- 10666676
TI - Isolation and analysis of chromosome 21 genes potentially involved in Down
syndrome.
PMID- 10666677
TI - Differential display reveals deteriorated mRNA levels of NADH3 (complex I) in
cerebellum of patients with Down syndrome.
AB - Although gene hunting has been carried out in Down Syndrome (DS) cells,
information on expressional differences in DS brain is limited. We have recently
described expressional differences in fetal DS brain but cannot assign these
findings to "DS per" se or simply to "neurodegeneration". We therefore performed
gene hunting in cerebellum of adult patients with DS and Alzheimer's disease (AD)
neuropathology, AD and controls. The gene hunting method used was differential
display and pools of the individual groups were examined to rule out allelic
differences. Differential display revealed the absence of a band, identified by
sequencing and gene bank work as matching the NADH3 gene (99.1% identity) in
cerebellum of DS patients. Dot blots showed the presence of NADH3 signals in only
two out of 7 DS patients. We show at the transcriptional level that a
mitochondrial enzyme, the complex I, NADH3, is significantly downregulated in DS
cerebellum. This extends previous work on deficiencies of the electron transport
chain in platelets of patients with DS.
PMID- 10666678
TI - Serotonin (5-HT) in brains of adult patients with Down syndrome.
AB - Down syndrome (DS) is a genetic disease with developmental brain abnormalities
resulting in early mental retardation and precocious, age dependent Alzheimer
type neurodegeneration. Furthermore, non-cognitive symptoms may be a cardinal
feature of functional decline in adults with DS. As the serotonergic system plays
a well known role in integrating emotion, cognition and motor function, serotonin
(5-HT) and its main metabolite, 5-hydroxyindol-3-acetic acid (5-HIAA) were
investigated in post-mortem tissue samples from temporal cortex, thalamus,
caudate nucleus, occipital cortex and cerebellum of adult patients with DS,
Alzheimer's disease (AD) and controls by use of high performance liquid
chromatography (HPLC). In DS, 5-HT was found to be age-dependent significantly
decreased in caudate nucleus by 60% (DS: mean +/- SD 58.6 +/- 28.2 vs. Co: 151.7
+/- 58.4 pmol/g wet tissue weight) and in temporal cortex by about 40% (196.8 +/-
108.5 vs. 352.5 +/- 183.0 pmol/g), insignificantly reduced in the thalamus,
comparable to controls in cerebellum, whereas occipital cortex showed increased
levels (204.5 +/- 138.0 vs. 82.1 +/- 39.1 pmol/g). In all regions of DS samples,
alterations of 5-HT were paralleled by levels of 5-HIAA, reaching significance
compared to controls in thalamus and caudate nucleus. In AD, 5-HT was
insignificantly reduced in temporal cortex and thalamus, unchanged in cerebellum,
but significantly elevated in caudate nucleus (414.3 +/- 273.7 vs. 151.7 +/- 58.4
pmol/g) and occipital cortex (146.5 +/- 76.1 vs. 82.1 +/- 39.1 pmol/g). The
results of this study confirm and extend putatively specific 5-HT dysfunction in
basal ganglia (caudate nucleus) of adult DS, which is not present in AD. These
findings may be relevant to the pathogenesis and treatment of cognitive and non
cognitive (behavioral) features in DS.
PMID- 10666679
TI - Mechanisms of neuronal death in Down's syndrome.
AB - There is growing evidence that neuronal death in Down's syndrome is due to
apoptotic mechanisms. The phenomena, however, that trigger and regulate
programmed cell death in the Down's syndrome-related neurodegeneration are still
much debated. In vitro evidence has suggested that the main factor responsible
for neuronal death in this condition is the accumulation of beta-amyloid, due to
the overexpression of its precursor protein. Another hypothesis argues for the
importance of reactive oxygen species in neuronal death. However, the in vivo
findings do not entirely support either theories. We propose that neuronal
apoptosis, as well as the formation of Alzheimer-type pathology, in Down's
syndrome is due to an aberrant re-entry of neurones into the cell division cycle.
Due to the simultaneous overexpression of conflicting cell cycle regulatory
signals the mitogenic amyloid precursor and the differentiation factor S100, the
cell cycle is abandoned. Subsequently the cell cycle arrest may lead to either
the formation of Alzheimer-related pathology or to apoptotic cell death.
PMID- 10666680
TI - Impaired brain glucose metabolism in patients with Down syndrome.
AB - A series of impaired metabolic functions in Down Syndrome (DS) including glucose
handling has been described. Recent information from positron emission tomography
studies in DS patients and our finding of downregulated phosphoglucose isomerase
(PGI) in fetal brain with DS by gene hunting using subtractive hybridization,
made us investigate PGI, a key enzyme of glucose metabolism, in brain of patients
with DS, Alzheimer's disease (AD) and controls. PGI and phosphofructokinase (PFK)
activities were determined in frontal, parietal, temporal, occipital lobe and
cerebellum of 9 controls, 9 patients with DS and 9 patients with AD. PGI activity
in DS brain was significantly decreased in frontal, temporal lobe and cerebellum,
comparable to controls in parietal lobe and elevated in occipital lobe. Brain PGI
activity of patients with AD was comparable to controls in all regions tested,
PFK, a rate limiting enzyme of glucose metabolism, was comparable between all
brain regions of all three groups. Data of this study confirm impaired glucose
metabolism in DS proposed in literature and found by positron emission tomography
(PET) studies. We show that changes in glucose handling in patients with AD as
evaluated by PET studies are not supported by our data, although not
contradictory, as determinants other than glucose metabolizing enzymes as e.g.
vascular factors and glucose transport may account for these findings. Changes of
downregulated PGI found by subtractive hybridization at the transcriptional level
in fetal DS brain along with our findings in DS brain regions suggest a strong
specific link between glucose metabolism and DS rather than AD.
PMID- 10666681
TI - Oxidative stress and neural dysfunction in Down syndrome.
AB - Total or partial trisomy of chromosome 21 occurs with relatively high frequency
and is responsible for the occurrence of Down syndrome. Phenotypically,
individuals with Down syndrome display characteristic morphological features and
a variety of clinical disorders. One of the challenges for researchers in this
field has been to ascertain and understand the relationship between the Down
syndrome phenotype with the gene dosage effect resulting from trisomy of
chromosome 21. Much attention therefore, has been given towards investigating the
consequences of overexpressing chromosome 21-linked genes. In particular, an
extensive analysis of SOD1 and APP have provided important insights as to how
perturbations in the expression of their respective genes may contribute to the
Down syndrome phenotype. In this review we will highlight studies which support a
key role for SOD1 and APP in the pathogenesis of neural abnormalities observed in
individuals with Down syndrome. Central to this relationship is how the redox
state of the cell is affected and its consequences to neural function and
integrity.
PMID- 10666682
TI - Expression of the transcription factor ETS2 in brain of patients with Down
syndrome--evidence against the overexpression-gene dosage hypothesis.
AB - Overexpression of the transcription factor ETS2 and other genes localized in the
socalled critical Down Syndrome region of chromosome 21 due to a gene dosage
effect, is an attractive hypothesis for the explanation of the Down Syndrome
phenotype. The overexpression of ETS2, however, has never been demonstrated in a
human organ. We therefore challenged this hypothesis determining ETS2 levels in
several brain regions of patients with Down Syndrome as compared to controls. We
used a highly sensitive and quantitative RT-PCR method for the determination of
ETS2 mRNA steady state levels in frontal, parietal, temporal, occipital lobe and
cerebellum of 9 adult Down Syndrome patients and 9 adult controls. Significantly
decreased ETS2 mRNA steady state levels (16.9 +/- 26.7 attogram mRNA ETS2/10 ng
total RNA versus 87.7 +/- 92.9 in controls) in frontal lobe of Down Syndrome
brain and decreased ETS2 mRNA steady state levels (6.99 +/- 6.4 attogram mRNA
ETS2/100 pg beta-actin versus 19.8 +/- 15.7 in controls) in temporal lobe of Down
Syndrome brain were found. In the other brain regions no statistically
significant difference was detected. Our data provide evidence against the
overexpression hypothesis for the development of the Down Syndrome phenotype.
Decreased ETS2 transcripts found in temporal and frontal lobe of patients with
Down Syndrome, however, may be involved in the pathogenesis of Down Syndrome
including specific neurodegenerative processes and deteriorated plasticity of the
brain taking place in Down Syndrome brain, as the concerted action of
transcription factors may be seriously impaired.
PMID- 10666683
TI - Neuronal apoptosis inhibitory protein (NAIP)-like immunoreactivity in brains of
adult patients with Down syndrome.
AB - In Down syndrome (DS), enhanced apoptosis (programmed cell death) may play a role
in the pathogenesis of characteristic early mental retardation and precocious
neurodegeneration of Alzheimer-type. The human IAP (inhibitor of apoptosis
proteins) genes (NAIP, c-IAP-2/HIAP-1, c-IAP-1/Hiap-2, XIAP, survivin) are an
evolutionary conserved family of proteins which prevent cell death across
species, implying that they act at a central, highly conserved point in the cell
death cascade. Evidence for downregulation of NAIP-mRNA in fetal DS (23rd week of
gestation), as found by subtractive hybridization technique challenged studies at
the protein level in adult DS brain specimen. NAIP-like immunoreactivity was
determined in four different regions of cerebral cortex and cerebellum in 9 adult
DS patients with Alzheimer-like neuropathologic lesions, 9 Alzheimer disease (AD)
patients as compared to 9 controls. For the first time, NAIP-IR could be
demonstrated in different cortical regions of the human brain. Compared to
control subjects, western blotting demonstrated significantly decreased levels in
parietal and occipital cortex in DS and in frontal and occipital cortex in AD.
While the mode of NAIP action is unknown, inhibition of certain caspases has
already been demonstrated for other IAP-family members (c-IAP1, c-IAP2 and XIAP).
Although decreased NAIP-IR of certain brain regions in DS and AD awaits further
confirmation, the results suggest that alterations of apoptosis regulatory
(inhibitory) proteins may be another feature of neurodegeneration in DS and AD.
PMID- 10666684
TI - The "gene dosage effect" hypothesis versus the "amplified developmental
instability" hypothesis in Down syndrome.
AB - Two hypotheses exist to explain the Down syndrome (DS) phenotype. The "gene
dosage effect" hypothesis states that the phenotype is a direct result of the
cumulative effect of the imbalance of the individual genes located on the
triplicated chromosome or chromosome region. In a nut shell, the phenotype
results directly from the overexpression of specific chromosome 21 genes. The
"amplified developmental instability" hypothesis contends that most
manifestations of DS may be interpreted as the results of a non-specific
disturbance of chromosome balance, resulting in a disruption of homeostasis. This
hypothesis was proposed in an attempt to explain the similarities between the
phenotypes of different aneuploid states and the observation that all of the
phenotypic traits in DS are also seen in the general population but at lower
frequency, with less severity and usually only present as a single trait. Herein,
we review recent data and present evidence to support the theory that the
phenotypic traits of aneuploid syndromes, and DS in particular, result from the
increased dosage of genes encoded on the triplicated chromosome.
PMID- 10666685
TI - Downregulation of the transcription factor scleraxis in brain of patients with
Down syndrome.
AB - Performing gene hunting in fetal Down Syndrome (DS) brain, we found a
downregulated sequence with 100% homology to the basic-helix-loop-helix
transcription factor (TF) scleraxis (Scl). It was the aim of the study to
evaluate Scl-mRNA steady state levels in adult DS brain with Alzheimer's disease
(AD) neuropathological changes, brain of patients with AD, and controls in order
to find out whether Scl-downregulation is linked to DS per se or simply to
neurodegeneration, common to both disorders. Determination of Scl-mRNA steady
state levels was carried out by a blotting method in frontal, parietal, temporal,
occipital lobe and cerebellum. We found significantly decreased Scl-transcripts
in brain of DS and AD, both, when normalized versus the house-keeping gene beta
actin or total RNA. We demonstrate the significant decrease of Scl-mRNA steady
state levels in the pathogenesis of DS and AD suggesting a tentative role for
this transcription factor in the development of the neurodegenerative processes
known to occur in both disorders. More specifically, the biological meaning of
the downregulation of Scl may be the involvement in the pathogenesis of impaired
neuronal plasticity and wiring observed in DS and AD, phenomena regulated by the
concerted action of the many transcription factors expressed in human brain.
PMID- 10666686
TI - Heat-shock protein 70 levels in brain of patients with Down syndrome and
Alzheimer's disease.
AB - Heat-shock proteins are proteins serving as molecular chaperones, involved in the
protection of cells from various forms of stress. Since the expression of these
proteins is closely related to that of amyloid precursor protein (APP), heat
shock protein has been studied in brain of patients with Alzheimer's disease (AD)
and furthermore, brain Hsp70 mRNA levels were related to the agonal state. The
aim of our study was to demonstrate the presence of Hsp70--immunoreactive protein
in brain of controls, patients with AD and Down Syndrome (DS) in individual brain
regions. The rationale for the study was to test the hypothesis that expression
of Hsp70, a protein involved in apoptosis would be altered in brain of these
patients with neurodegenerative disorders where (neuronal) apoptosis is a
hallmark of the disease. Brain immunoreactive-Hsp70--protein (Hsp70) was
determined by Western blotting using specific monoclonal antibody in five
different brain regions (frontal, parietal, occipital, temporal cortex and
cerebellum) from controls, DS and AD patients. Hsp70 expression was significantly
increased in temporal cortex of patients with AD (arbitrary units: means +/- SD;
0.35 +/- 0.49 for controls, 0.97 +/- 0.70 for DS patients, 1.16 +/- 0.56 for AD
patients). In frontal and parietal cortex from DS patients, there was a strong
correlation between Hsp70 levels and the length of post-mortem interval (r =
0.95, P < 0.01 and r = 0.82, P < 0.021).
PMID- 10666687
TI - Increased levels of 14-3-3 gamma and epsilon proteins in brain of patients with
Alzheimer's disease and Down syndrome.
AB - The 14-3-3 family consists of homo- and heterodimeric proteins representing a
novel type of "adaptor proteins" modulating the interaction between components of
signal transduction pathways. 14-3-3 isoforms interact with phosphoserine motifs
on many proteins as kinases, phosphatases, apoptosis related proteins etc.
Performing protein mapping by 2D electrophoresis in human brain we identified two
isoforms, 14-3-3 gamma and epsilon and decided to determine these two
multifunctional proteins in several brain regions of aged patients with
Alzheimer's disease (AD) and Down Syndrome (DS) with AD neuropathology in
comparison with control brains. 14-3-3 gamma and 14-3-3 epsilon proteins were
increased in several brain regions of AD and DS patients. These changes may
contribute to the complex pathomechanisms of AD and AD in DS, evolving inevitably
from the fourth decade of life. Deranged 14-3-3 isoforms gamma and epsilon may
reflect impaired signaling and/or apoptosis in the brain as several kinases
(protein kinase C, Ras, mitogen-activated kinase MEK) involved in signaling and
apoptotic factors as bcl-2-related proteins BAD and BAG-1 are binding to 14-3-3
motifs.
PMID- 10666688
TI - Application of Alu-splice PCR on chromosome 21: DSCR1 and Intersectin.
AB - Down syndrome (DS) is a major cause of mental retardation and congenital heart
defects, with an overall incidence of one in 700 live births. DS is caused by
increases in the amounts of a number of normal gene products, the exact number
and identity of which are presently unknown. Elucidating the molecular basis of
DS relies on the identification of the gene products whose augmentation by 50% or
more causes symptoms of the disease. With the aim of contributing to the
transcriptional map of human chromosome 21 and to identify new genes with
potential involvement in DS, we developed a technique to isolate expressed
sequences called Alu-splice PCR, which is very simple to perform and is
independent of gene expression patterns. Putative exons are PCR amplified in
genomic DNA by virtue of their proximity to Alu repeats using primers designed
from splice-site consensus sequences in combination with specific Alu repeat
primers. The Alu repeats, which are repetitive DNA elements found exclusively and
at high frequency in the genomes of primates, impart the human specificity to the
method. The splice-site consensus sequences were used to direct primers to exon
boundaries. Using the Alu-splice technique, we have identified at least three new
genes. We trapped an exon of DSCR1 (Down Syndrome Candidate Region 1) and two
different exons of a gene called human Intersectin (ITSN). Presently, we are
working with another novel trapped exon to identify the corresponding gene. The
major advantage of Alu-splice PCR is that the technique can be readily
established in any laboratory which has the basic facilities for molecular
biology because no specialised materials or expertise is required.
PMID- 10666689
TI - Overexpression of DNAse I in brain of patients with Down syndrome.
AB - Human DNAse I (EC 3.1.21.1) is an enzyme most probably involved in apoptotic
processes. Splicing of the DNAse I primary transcript in normal and apoptotic
cells into up to 20 splicing forms and the recent description of a different
family of caspase-activated DNAses, hampered studies on the role of DNAse I in
apoptosis research. Performing gene hunting in fetal brain of patients with DS we
found a sequence with 100% homology to DNAse I and this formed the Rationale for
studies in adult DS brain. It was therefore the aim of the study to evaluate
DNAse I-mRNA steady state levels in DS brain using adult brain without brain
pathologies and Alzheimer's Disease (AD) brain as control, in order to rule out
that DNAse I--overexpression may not be specific for DS but rather reflecting
apoptosis per se, a hallmark of both disorders. Determination of DNAse I-mRNA
steady state levels was carried out by a blotting method in frontal, parietal,
temporal occipital lobe and cerebellum. We found significantly increased DNAse I
transcripts in brain of DS and AD both, when normalized versus the house-keeping
gene beta actin or total RNA. We demonstrate the significant increase of DNAse I-
transcript in the pathogenesis of DS and AD suggesting a role for this enzyme in
the apoptotic process known to occur in both disorders. We are now going to carry
out protein and enzyme activity levels in our laboratory to confirm our findings
at the transcriptional level.
PMID- 10666690
TI - [The hyoid bone and its preservation in the framework of supraglottic partial
resection of the larynx].
AB - BACKGROUND: Whether to remove the hyoid bone as part of the horizontal partial
laryngectomy is a question which is discussed controversially. Pathohistological
examination of the region involved should help to answer this question. MATERIAL
AND METHODS: Regarding the involvement of the hyoid bone, 71 surgical specimens
of supraglottic carcinoma invading the pre-epiglottic space were studied by whole
organ serial sections. RESULTS: Only four specimens demonstrated mandatory
resection of the hyoid bone because of its proximity to the advancing border of
the tumor. In these cases, large tumor masses were palpable directly under the
thyrohyoid membrane after the strap muscles had been dissected during the
operation. DISCUSSION: Except for these rare cases in which the tumor was already
palpable from outside the larynx, preservation of the hyoid bone during
horizontal supraglottic laryngectomy is oncologically safe. It provides a more
secure closure of the pharyngotomy and promotes earlier return of the swallowing
function because of the maintenance of the normal position of the larynx and
pharynx.
PMID- 10666691
TI - [Pathomorphological aspects of transoral resection of hypopharyngeal carcinoma
with preservation of the larynx. Patient selection, treatment results].
AB - BACKGROUND: In primary surgery of hypopharyngeal cancer, transcervical resection
was chosen in order to preserve the larynx. This treatment produces good
oncological results but also a high degree of morbidity so that in recent years
transoral resection has been recommended. For wider application of this method it
is very important to apply clearly defined criteria for selection of patients.
MATERIAL AND METHODS: To define the criteria for selection for transoral
microsurgical resection, we analyzed step serial sections of 33 whole organ
specimens of hypopharyngeal squamous cell cancer (SCC) after primary radical
surgery, mostly carcinoma of the piriform sinus. Criteria concerning the primary
and the involvement of the neck nodes were differentiated. Twenty of 84 patients
with hypopharyngeal cancer of different stages were treated by transoral
resection and delayed neck dissection between 1994 and 1996. Most of the patients
were irradiated postoperatively because of neck metastases. The therapeutic
results after a minimum period of 24 months follow-up is listed according to
Kaplan-Meyer. RESULTS: Three types were defined according to their site, growth,
and spread into the larynx: Type I comprises limited exophytic, highly
differentiated SCC with a minor tendency for metastasis originating in the upper
half of the sinus. These tumors are well suitable for transoral resection. Type
II includes tumors spreading superficially without deeper invasion of the larynx,
especially of the laryngeal framework. These can be totally resected and the
larynx preserved in spite of extended metastasis. Type III, the most frequent
type, grows with ulceration and deeply infiltrates into the larynx and the neck.
These tumors cannot be resected transorally. Primary radical resection is
indicated. Up to 25% of all hypopharyngeal SCC could be treated by transoral
resection, mostly with delayed neck dissection and postoperative irradiation.
Functional results were excellent in all cases. Eating, voice, and air passage
were normal. Oncological results with 80% disease free five-year survival rate
were very good. Three patients died because of recurrences in the neck, only one
because of a recurrence in the larynx. The rate of patients with a second
primary, however, was extremely high (50%). CONCLUSIONS: By strictly following
the pathological and clinical criteria for selection, about 25% of the SCC of the
hypopharynx can be treated by transoral resection combined with neck dissection
and postoperative irradiation with good oncological and excellent functional
results, preserving the larynx without endangering the life of the patients.
PMID- 10666692
TI - [Studies on significance of sentinel lymphadenectomy in pharyngeal and laryngeal
carcinoma].
AB - BACKGROUND: Management of the suspected N0-neck (sonography and CT) in squamous
cell carcinoma (SCC) of the head and neck is discussed controversially. The
question arises whether the sentinel node (SN) concept as it is performed in
different areas of clinical oncology is applicable to ear, nose, and throat
medicine. METHODS: Nine male patients with SCC were studied (4 oropharynx, 2
hypopharynx, and 3 larynx) in whom different lymph node status was diagnosed
clinically (5 x N0, 2 x N1, 2 x N2c). After intraoperative scintillation probe
detection, the histological examination of the SN with neck dissection (ND)
specimen followed. RESULTS: In 7 of 9 cases SN detection was successful. In 4 of
5 cases of clinical N0 status, SN, and ND specimens were free of tumor
histologically, while in one patient radiolabel-identified SN showed tumor cells
in histological examination. In 2 patients with clinical N1 neck, SN, and ND were
histologically tumor-free in one patient and contained one single tumor
metastasis located in the SN in the other patient. In 2 patients with clinically
and histologically proven N2c neck, lymph nodes located in regions II and III
showed metastasis including capsular rupture. In both cases no lymph node
radioactivity was detectable during the operation. CONCLUSIONS: The results
suggest that sentinel lymphonodectomy may be suited for ear, nose, and throat
medicine. Before it is applied to clinical practice, further problems must be
resolved. These include the short distance between the primary injection side and
lymph nodes and the influence of intranodal tumor metastasis on the uptake of the
radiolabeled tracer.
PMID- 10666693
TI - [Multiple carcinomas in the upper aerodigestive tract. 1. Oral cavity and
oropharynx].
AB - BACKGROUND: During the last years an absolute increase of tumour incidence of
squamous cell carcinoma as well as an increase in the occurrence of synchronous
and metachronous multiple primaries in the upper aerodigestive tract can be
observed. This study analyses the so-called "multi-centric cancerization" in
patients with primary carcinoma of the oral cavity and the oropharynx. METHODS:
During 2 observation periods of 5 years each, from 1985 to 1994, we
retrospectively analyzed 235 patients with squamous cell carcinoma of the oral
cavity and 232 patients with tumour localisation in the oropharynx. Besides age,
sex, tumour localization, TNM-stage and grading, the risk factors tobacco and
alcohol were added as causes for the development of multiple primaries. RESULTS:
In the primary localisation of the oral cavity synchronous and metachronous
double tumours increased from 7% to 17% besides the absolute increase in tumour
incidence. In the oropharynx a total increase of second carcinomas from 3% to 20%
was found. At the same time a growing abuse of tobacco and alcohol could be
observed. CONCLUSIONS: Panendoscopy during pre-therapeutical staging should be
obligatory. Regular oncological controls are mandatory, especially for younger
patients with smaller tumours and good prognosis, but a high risk of second
primaries. In the long run, prevention has to play a decisive role in the fight
against second primary tumors of the upper aerodigestive tract. Possible
improvements of early diagnosis, genetical examinations, information campaigns as
well as research of carcinogenic environmental pollutants are of foremost
interest to the clinician.
PMID- 10666694
TI - [Mutagen sensitivity of patients with laryngeal and oropharyngeal carcinoma].
AB - BACKGROUND: Carcinogenesis in the larynx and oropharynx is often associated with
excessive exposure to tobacco smoke and alcohol. However, attention is
increasingly being focused on genetically determined mutagen sensitivities and on
the mutagenic impact of xenobiotics. The purpose of this study was to evaluate
the genotoxicity of phthalates (plasticizers widely used in synthetic materials),
as well as nitrosamines and polycyclic aromatic carbohydrates, on laryngeal and
oropharyngeal epithelia and peripheral lymphocytes of patients with laryngeal and
oropharyngeal carcinomas. METHODS: The comet assay was used to detect induced DNA
strand breaks. Macroscopically healthy supraglottic and oropharyngeal epithelia
of patients with laryngeal and oropharyngeal tumors, respectively, and
lymphocytes were investigated with dibutyl phthalate (DBP), diisobutylphthalate
(DiBP). N'nitrosodiethylamine (NDELA), and benzo[a]pyrene (BaP). The Olive Tail
Moment (OTM) was used to quantify genotoxicity. RESULTS: For the first time, the
genotoxicity of DBP and DiBP was demonstrated in laryngeal and oropharyngeal
epithelia, as well as in peripheral lymphocytes, of patients suffering from
laryngeal and oropharyngeal carcinomas. OTM levels for NDELA were higher than for
phthalates; levels for BaP were lower. Testing of lymphocytes and mucosa showed
no significant differences among the various substances. CONCLUSIONS: Phthalates
show a genotoxic impact on epithelia of tumor patients. OTM levels were higher
than in nasal and oropharyngeal mucosa of healthy donors in results reported
earlier. Thus, specific susceptibilities to these xenobiotics need to be
discussed. No such effect was demonstrated for NDELA and BaP. In tumor patients,
no significant differences could be shown in mutagenic sensitivities in mucosal
cells and lymphocytes.
PMID- 10666695
TI - [Endoscopic imaging techniques in the diagnosis of laryngeal carcinoma and its
precursor lesions].
AB - BACKGROUND: In order to improve preoperative diagnostic work-up in treatment of
patients with laryngeal cancer and its precursor lesions additional endoscopical
imaging techniques have been developed: 1. Autofluorescence endoscopy; 2. Contact
endoscopy; 3. Endoscopic high-frequency ultrasound. These imaging techniques are
used during microlaryngoscopy to get further information about tumor extension
and differentiation. This paper describes the diagnostic potential of these
imaging techniques in the evaluation of cancerous lesions of the larynx. MATERIAL
AND METHODS: Patients in different stages of laryngeal dysplasia, carcinoma in
situ and laryngeal cancer were examined by means of the previous mentioned
imaging techniques during microlaryngoscopy (Autofluorescence endoscopy [n = 38],
contact endoscopy [n = 323], endoscopic high-frequency ultrasound [n = 60]) and
the results were compared to pathohistological findings. In autofluorescence
endoscopy cancerous mucosa was illuminated using blue filtered light (380-460 nm)
to obtain autofluorescence for optical demarcation of the lesion. Contact
endoscopy was performed after staining of the laryngeal mucosa with methylene
blue (1%). Two different endoscopes with 60 x and 150 x magnification were used.
In both techniques a video image was achieved by using a xenon light source and a
special video camera to register autofluorescence. The endoscopical high
frequency ultrasound examination was performed after flooding the larynx with
0.9% saline. Newly developed ultrasound catheters with frequencies between 10 to
20 MHz were inserted in the laryngeal lumen and moved in a standardized pattern
during the examination. RESULTS: During the autofluorescence examination of the
endolaryngeal mucosa precancerous and cancerous lesions showed a red to violet
fluorescence outlined against the light green autofluorescence of the normal
mucosa. Hyperplastic hyperkeratotic epithelium revealed a higher intensity of
light green or even whitish autofluorescence compared to normal mucosa
autofluorescence. After staining the vocal cords with methylene blue, it was
possible to observe the cells, nuclei and cytoplasm of the laryngeal mucosa and
their different grades of abnormality using the specially developed contact
endoscopes. Endoscopic high-frequency ultrasound (10 to 20 MHz) was able to
measure the vertical extension of laryngeal carcinomas bigger than 3 mm in size.
The involvement of the thyroid cartilage or the anterior commissure could be
visualized. Preoperatively, the critical T2 stage could be evaluated more
precisely. In precancerous lesions and microinvasive cancer ultrasound added no
additional Information to the microlaryngoscopical picture. CONCLUSION:
Autofluorescence, contact endoscopy as well as endoscopic high-frequency
ultrasound are promising new imaging techniques supplementing microlaryngoscopy:
autofluorescence as well as contact endoscopy are suitable to differentiate
dysplasia, carcinoma in situ, microinvasive lesions as well as the evaluation of
tumorous margins, while high-frequency ultrasound improves the assessment of
tumorous infiltration into the depth of the larynx. These imaging techniques
enable the laryngologist to perform a more accurate diagnostic work-up in the
assessment of laryngeal cancer and its precursor lesions.
PMID- 10666696
TI - [Long-term results of homograft reconstruction of the trachea in childhood].
AB - BACKGROUND: The treatment of long-segment tracheal stenosis in children is a
biological and operative problem. The introduction of preserved allografts
established new possibilities for functional tracheal reconstruction. The
development of tracheal dimensions in the course of growing is often discussed.
PATIENTS AND METHODS: Since 1983 preserved allografts were used in 20 children
with acquired tracheal stenosis. The children ranged in age from 1 to 13 years
(average: 7.2 years) when the operation was performed. The children were examined
postoperatively at adequate intervals. Radiologic measurements of the tracheal
dimensions were performed in some of the patients. RESULTS: Today the treatment
of all of these children is complete. Some of them are now adults. None of the
children demonstrated breathing problems at the time of the end of treatment or
after a variable following-up period ranging from 18 months to 14 years. There
was no endoscopic or radiographic evidence of constriction in the growing
tracheas. Radiographic measurement of the reconstructed tracheas showed an age
adequate growth in length and a small growth in diameter. CONCLUSION: Functional
tracheal reconstruction for long-segment tracheal stenosis can be achieved by
implantation of preserved allografts even in the early childhood.
PMID- 10666697
TI - [Combined transseptal-transnasal surgery of unilateral choanal atresia without
using stents].
AB - BACKGROUND: This is a report of a surgical procedure with which stenting after
surgery of unilateral choanal atresia can be avoided. METHOD: We start
transseptally with a hemitransfixion incision. The vomer and the bony atresia
plate are dissected submucosally and then resected with punches and a diamond
burr, whilst the nasal and the pharyngeal mucosa of the atresia is preserved
completely. The next step is to cut transnasally a door-like flap out of the
nasal blade of the mucosa of the atresia, that is based laterally and with which
the lateral raw surface of the new choana will be covered. Now a medially based
door-like flap is cut out of the up to now intact pharyngeal blade of the
atresia, with which the medial wound surface is to be covered. The flaps are
fixed with fibrin glue and with a nasal tamponade for two days, as after
septoplasty. It is not necessary to insert stents anymore. RESULTS: Between 1995
until 1998 we treated three female and two male patients using this method. Their
ages were 6, 17, 17, 20 and 35 years and the postoperative observation lasted 2,
4, 1, 3 and 3 years. A restenosis was not seen in any of the cases. CONCLUSION:
Because of these results, it is recommended to treat unilateral choanal atresias
of adults and children older than five years by using a combined transseptal
transnasal procedure. By using the described surgical technique postoperative
stenting can be avoided.
PMID- 10666698
TI - [Current aspects of hearing aid fitting: technique, goals and testing].
PMID- 10666699
TI - [The interesting case No. 31. Eyelid inflammation in childhood].
PMID- 10666700
TI - [100 years of the Otto Korner ENT Clinic, Rostock. The merits of Christian Lemcke
and Otto Korner in the development of ENT specialty].
AB - BACKGROUND: The first special ENT hospital in Germany and northern Europe, the
Department of Otorhinolaryngology, Head- and Neck-Surgery "Otto Korner" in
Rostock is celebrating its 100th anniversary on October 25, 1999. METHODS: There
is a presentation on the efforts in the ENT-specialty from the beginning
considering the special situation at the university of Rostock. RESULTS: The
efforts of Christian Lemcke (1850-1894), who associated the three sections
Otology, Laryngology and Rhinology are appreciated, Otto Korner (1859-1935)
continued this development. He achieved the building of a special ENT-hospital by
his excellent knowledge and surgical skills. The opening date was October 25,
1899, Korner became the first full professor in Otology and Laryngology in
Germany in 1901. His "Textbook Of Otology And It's Bordering Specialties" was
published in 1906. As one of the first, he supported the independence of ENT
medicine as a separate field in the course of medicine. CONCLUSION: Today, Otto
Korner's claims are more relevant than ever before, because the today's students
in their practical course of medicine and even young doctors at the hospitals
obviously show a lack of knowledge in the ENT-field. The current "multiple
choice" type of examinations could be one of the main reasons.
PMID- 10666701
TI - [Surgical measures in pharyngo-esophageal dysphagia and chronic aspiration].
PMID- 10666702
TI - Population bottlenecks and Pleistocene human evolution.
AB - We review the anatomical and archaeological evidence for an early population
bottleneck in humans and bracket the time when it could have occurred. We outline
the subsequent demographic changes that the archaeological evidence of range
expansions and contractions address, and we examine how inbreeding effective
population size provides an alternative view of past population size change. This
addresses the question of other, more recent, population size bottlenecks, and we
review nonrecombining and recombining genetic systems that may reflect them. We
examine how these genetic data constrain the possibility of significant
population size bottlenecks (i.e., of sufficiently small size and/or long
duration to minimize genetic variation in autosomal and haploid systems) at
several different critical times in human history. Different constraints appear
in nonrecombining and recombining systems, and among the autosomal loci most are
incompatible with any Pleistocene population size expansions. Microsatellite data
seem to show Pleistocene population size expansions, but in aggregate they are
difficult to interpret because different microsatellite studies do not show the
same expansion. The archaeological data are only compatible with a few of these
analyses, most prominently with data from Alu elements, and we use these facts to
question whether the view of the past from analysis of inbreeding effective
population size is valid. Finally, we examine the issue of whether inbreeding
effective population size provides any reasonable measure of the actual past size
of the human species. We contend that if the evidence of a population size
bottleneck early in the evolution of our lineage is accepted, most genetic data
either lack the resolution to address subsequent changes in the human population
or do not meet the assumptions required to do so validly. It is our conclusion
that, at the moment, genetic data cannot disprove a simple model of exponential
population growth following a bottleneck 2 MYA at the origin of our lineage and
extending through the Pleistocene. Archaeological and paleontological data
indicate that this model is too oversimplified to be an accurate reflection of
detailed population history, and therefore we find that genetic data lack the
resolution to validly reflect many details of Pleistocene human population
change. However, there is one detail that these data are sufficient to address.
Both genetic and anthropological data are incompatible with the hypothesis of a
recent population size bottleneck. Such an event would be expected to leave a
significant mark across numerous genetic loci and observable anatomical traits,
but while some subsets of data are compatible with a recent population size
bottleneck, there is no consistently expressed effect that can be found across
the range where it should appear, and this absence disproves the hypothesis.
PMID- 10666703
TI - Evidence from beta-tubulin phylogeny that microsporidia evolved from within the
fungi.
AB - Microsporidia are obligate intracellular parasites that were thought to be an
ancient eukaryotic lineage based on molecular phylogenies using ribosomal RNA and
translation elongation factors. However, this ancient origin of microsporidia has
been contested recently, as several other molecular phylogenies suggest that
microsporidia are closely related to fungi. Most of the protein trees that place
microsporidia with fungi are not well sampled, however, and it is impossible to
resolve whether microsporidia evolved from a fungus or from a protistan relative
of fungi. We have sequenced beta-tubulins from 3 microsporidia, 4 chytrid fungi,
and 12 zygomycete fungi, expanding the representation of beta-tubulin to include
all four fungal divisions and a wide diversity of microsporidia. In phylogenetic
trees including these new sequences, the overall topology of the fungal beta
tubulins generally matched the expected relationships among the four fungal
divisions, although the zygomycetes were polyphyletic in some analyses. The
microsporidia consistently fell within this fungal diversification, and not as a
sister group to fungi. Overall, beta-tubulin phylogeny suggests that
microsporidia evolved from a fungus sometime after the divergence of chytrids. We
also found that chytrid alpha- and beta-tubulins are much less divergent than are
tubulins from other fungi or microsporidia. In trees in which the only fungal
representatives were the chytrids, microsporidia still branched with fungi (i.e.,
with chytrids), suggesting that the affiliation between microsporidian and fungal
tubulins is not an artifact of long-branch attraction.
PMID- 10666704
TI - Estimating synonymous and nonsynonymous substitution rates under realistic
evolutionary models.
AB - Approximate methods for estimating the numbers of synonymous and nonsynonymous
substitutions between two DNA sequences involve three steps: counting of
synonymous and nonsynonymous sites in the two sequences, counting of synonymous
and nonsynonymous differences between the two sequences, and correcting for
multiple substitutions at the same site. We examine complexities involved in
those steps and propose a new approximate method that takes into account two
major features of DNA sequence evolution: transition/transversion rate bias and
base/codon frequency bias. We compare the new method with maximum likelihood, as
well as several other approximate methods, by examining infinitely long
sequences, performing computer simulations, and analyzing a real data set. The
results suggest that when there are transition/transversion rate biases and
base/codon frequency biases, previously described approximate methods for
estimating the nonsynonymous/synonymous rate ratio may involve serious biases,
and the bias can be both positive and negative. The new method is, in general,
superior to earlier approximate methods and may be useful for analyzing large
data sets, although maximum likelihood appears to always be the method of choice.
PMID- 10666705
TI - A diverse population of introns in the nuclear ribosomal genes of ericoid
mycorrhizal fungi includes elements with sequence similarity to endonuclease
coding genes.
AB - Ericoid mycorrhizal fungi form symbioses with the roots of members of the
Ericales. Although only two genera have been identified in culture, the taxonomic
diversity of ericoid symbionts is certainly wider. Genetic variation among 40
ericoid fungal isolates was investigated in this study. PCR amplification of the
nuclear small-subunit ribosomal DNA (SSU rDNA) and of the internal transcribed
spacer (ITS), followed by sequencing, led to the discovery of DNA insertions of
various sizes in the SSU rDNA of most isolates. They reached sizes of almost
1,800 bp and occurred in up to five different insertion sites. Their positions
and sizes were generally correlated with morphological and ITS-RFLP grouping of
the isolates, although some insertions were found to be optional among isolates
of the same species, and insertions were not always present in all SSU rDNA
repeats within an isolate. Most insertions were identified as typical group I
introns, possessing the conserved motifs characteristic of this group. However,
other insertions lack these motifs and form a distinct group that includes other
fungal ribosomal introns. Alignments with almost 70 additional sequences from
fungal nuclear SSU rDNA introns indicate that introns inserted at the same site
along the rDNA gene are generally homologous, but they also suggest the
possibility of some horizontal transfers. Two of the ericoid fungal introns
showed strong homology with a conserved motif found in endonuclease genes from
nuclear rDNA introns.
PMID- 10666706
TI - The phylogenetic position of the Talpidae within eutheria based on analysis of
complete mitochondrial sequences.
AB - The complete mitochondrial (mt) genome of the mole Talpa europaea was sequenced
and included in phylogenetic analyses together with another lipotyphlan
(insectivore) species, the hedgehog Erinaceus europaeus, and 22 other eutherian
species plus three outgroup taxa (two marsupials and a monotreme). The
phylogenetic analyses reconstructed a sister group relationship between the mole
and fruit bat Artibeus jamaicensis (order Chiroptera). The Talpa/Artibeus clade
constitutes a sister clade of the cetferungulates, a clade including Cetacea,
Artiodactyla, Perissodactyla, and Carnivora. A monophyletic relationship between
the hedgehog and the mole was significantly rejected by maximum parsimony and
maximum likelihood. Consistent with current systematic schemes, analyses of
complete cytochrome b genes including the shrew Sorex araneus (family Soricidae)
revealed a close relationship between Talpidae and Soricidae. The analyses of
complete mtDNAs, along with the findings of other insectivore studies, challenge
the maintenance of the order Lipotyphla as a taxonomic unit and support the
elevation of the Soricomorpha (with the families Talpidae and Soricidae and
possibly also the Solenodontidae and Tenrecidae) to the level of an order, as
previously proposed in some morphological studies.
PMID- 10666707
TI - Determinants of substitution rates in mammalian genes: expression pattern affects
selection intensity but not mutation rate.
AB - To determine whether gene expression patterns affect mutation rates and/or
selection intensity in mammalian genes, we studied the relationships between
substitution rates and tissue distribution of gene expression. For this purpose,
we analyzed 2,400 human/rodent and 834 mouse/rat orthologous genes, and we
measured (using expressed sequence tag data) their expression patterns in 19
tissues from three development states. We show that substitution rates at
nonsynonymous sites are strongly negatively correlated with tissue distribution
breadth: almost threefold lower in ubiquitous than in tissue-specific genes.
Nonsynonymous substitution rates also vary considerably according to the tissues:
the average rate is twofold lower in brain-, muscle-, retina- and neuron-specific
genes than in lymphocyte-, lung-, and liver-specific genes. Interestingly, 5' and
3' untranslated regions (UTRs) show exactly the same trend. These results
demonstrate that the expression pattern is an essential factor in determining the
selective pressure on functional sites in both coding and noncoding regions.
Conversely, silent substitution rates do not vary with expression pattern, even
in ubiquitously expressed genes. This latter result thus suggests that synonymous
codon usage is not constrained by selection in mammals. Furthermore, this result
also indicates that there is no reduction of mutation rates in genes expressed in
the germ line, contrary to what had been hypothesized based on the fact that
transcribed DNA is more efficiently repaired than nontranscribed DNA.
PMID- 10666708
TI - Molecular evolution of the Paramyxoviridae and Rhabdoviridae multiple-protein
encoding P gene.
AB - Presented here is an analysis of the molecular evolutionary dynamics of the P
gene among 76 representative sequences of the Paramyxoviridae and Rhabdoviridae
RNA virus families. In a number of Paramyxoviridae taxa, as well as in vesicular
stomatitis viruses of the Rhabdoviridae, the P gene encodes multiple proteins
from a single genomic RNA sequence. These products include the phosphoprotein
(P), as well as the C and V proteins. The complexity of the P gene makes it an
intriguing locus to study from an evolutionary perspective. Amino acid sequence
alignments of the proteins encoded at the P and N loci were used in independent
phylogenetic reconstructions of the Paramyxoviridae and Rhabdoviridae families. P
gene-coding capacities were mapped onto the Paramyxoviridae phylogeny, and the
most parsimonious path of multiple-coding-capacity evolution was determined.
Levels of amino acid variation for Paramyxoviridae and Rhabdoviridae P-gene
encoded products were also analyzed. Proteins encoded in overlapping reading
frames from the same nucleotides have different levels of amino acid variation.
The nucleotide architecture that underlies the amino acid variation was
determined in order to evaluate the role of selection in the evolution of the P
gene overlapping reading frames. In every case, the evolution of one of the
proteins encoded in the overlapping reading frames has been constrained by
negative selection while the other has evolved more rapidly. The integrity of the
overlapping reading frame that represents a derived state is generally maintained
at the expense of the ancestral reading frame encoded by the same nucleotides.
The evolution of such multicoding sequences is likely a response by RNA viruses
to selective pressure to maximize genomic information content while maintaining
small genome size. The ability to evolve such a complex genomic strategy is
intimately related to the dynamics of the viral quasispecies, which allow
enhanced exploration of the adaptive landscape.
PMID- 10666709
TI - Mitochondrial genomes of Galathealinum, Helobdella, and Platynereis: sequence and
gene arrangement comparisons indicate that Pogonophora is not a phylum and
Annelida and Arthropoda are not sister taxa.
AB - We report a contiguous region of more than half (> 7,500 nt) of the mitochondrial
genomes for Platynereis dumerii (Annelida: Polychaeta), Helobdella robusta
(Annelida: Hirudinida), and Galathealinum brachiosum (Pogonophora: Perviata). The
relative arrangements of all 22 genes identified for Helobdella and Galathealinum
are identical to one another and to their arrangements in the mtDNA of the
previously studied oligochaete annelid Lumbricus. In contrast, Platynereis
differs from these taxa in the positions of several tRNA genes and in having two
additional tRNA genes (trnC and trnM) and a large noncoding sequence in this
region. Comparisons of relative gene arrangements and of the nucleotide and
inferred amino acid sequences among these and other published taxa provide strong
support for an annelid-mollusk clade that excludes arthropods, and for the
inclusion of pogonophorans within Annelida, rather than giving them separate
phylum status. Gene arrangement comparisons include the first use of a recently
described method on previously unpublished data. Although a variety of
alternative initiation codons are typically used by mitochondrial protein
encoding genes, ATG appears to be the initiator for all but one reported here.
The large noncoding region (1,091 nt) identified in Platynereis has no
significant sequence similarity to the noncoding region of Lumbricus, although
each contains runs of TA dinucleotides and of homopolymers, which could
potentially serve as signaling elements. There is strong bias for synonymous
codon usage in Helobdella and especially in Galathealinum. In this latter taxon,
5 codons are completely unused, 13 are used three or fewer times, and G appears
at third codon positions in only 26 of the 2,236 codons. Nucleotide composition
bias appears to influence amino acid composition of the proteins.
PMID- 10666710
TI - Mitochondrial genomic rearrangements in songbirds.
AB - The organization of the mitochondrial genome is generally very conserved among
vertebrates. Because of this, examination of the rare rearrangements which do
occur has been suggested as offering a powerful alternative to phylogenetic
analyses of mitochondrial DNA sequences. Here, we report on an avian
mitochondrial rearrangement in a group of oscine passerines (warblers of the
genus Phylloscopus). This rearrangement is identical to the mitochondrial
organization recently identified in representatives of four orders of birds,
including subsoscine Passeriformes. The rearrangement involves the movement of
three genes (tRNA(Pro), NADH6, and tRNA(Glu)) from their normal position in birds
between tRNA(Thr) and the control region (CR), to a new location between the CR
and a novel, supposedly noncoding (NC), region. Our results suggest that this
derived arrangement cannot be used to distinguish between suboscine and oscine
passerines, as it has multiple origins both within Passeriformes and within birds
as a whole. We found short stretches of DNA with high degrees of similarity
between the CR and each NC region, respectively, all of which could be located in
the same area of the CR. This suggests that the CR and the NC region are
homologous and that the mechanism behind this mitochondrial rearrangement is a
tandem duplication followed by multiple deletions. However, the similarities
between the control and NC regions of each species were less pronounced than
those between the control or NC regions from the different species, supporting
the hypothesis of a single basal rearrangement in the Phylloscopus warblers.
PMID- 10666711
TI - A phylogenetic analysis of the lipocalin protein family.
AB - The lipocalins are a family of extracellular proteins that bind and transport
small hydrophobic molecules. They are found in eubacteria and a great variety of
eukaryotic cells, in which they play diverse physiological roles. We report here
the detection of two new eukaryotic lipocalins and a phylogenetic analysis of 113
lipocalin family members performed with maximum-likelihood and parsimony methods
on their amino acid sequences. Lipocalins segregate into 13 monophyletic clades,
some of which are grouped in well-supported superclades. An examination of the G
+ C content of the bacterial lipocalin genes and the detection of four new
conceptual lipocalins in other eubacterial species argue against a recent
horizontal transfer as the origin of prokaryotic lipocalins. Therefore, we rooted
our lipocalin tree using the clade containing the prokaryotic lipocalins. The
topology of the rooted lipocalin tree is in general agreement with the currently
accepted view of the organismal phylogeny of arthropods and chordates. The rooted
tree allows us to assign polarity to character changes and suggests a plausible
scenario for the evolution of important lipocalin properties. More recently
evolved lipocalins tend to (1) show greater rates of amino acid substitutions,
(2) have more flexible protein structures, (3) bind smaller hydrophobic ligands,
and (4) increase the efficiency of their ligand-binding contacts. Finally, we
found that the family of fatty-acid-binding proteins originated from the more
derived lipocalins and therefore cannot be considered a sister group of the
lipocalin family.
PMID- 10666712
TI - Rh gene evolution in primates: study of intron sequences.
AB - By amplification and sequencing of RH gene intron 4 of various primates we
demonstrate that an Alu-Sx-like element has been inserted in the RH gene of the
common ancestor of humans, apes, Old World monkeys, and New World monkeys. The
study of mouse and lemur intron 4 sequences allowed us to precisely define the
insertion point of the Alu-Sx element in intron 4 of the RH gene ancestor common
to Anthropoidea. Like humans, chimpanzees and gorillas possess two types of RH
intron 4, characterized by the presence (human RHCE and ape RHCE-like genes) or
absence (human RHD and ape RHD-like genes) of the Alu-Sx element. This led us to
conclude that in the RH common ancestor of humans, chimpanzees, and gorillas, a
duplication of the common ancestor gene gave rise to two genes, one differing
from the other by a 654-bp deletion encompassing an Alu-Sx element. Moreover,
most of chimpanzees and some gorillas posses two types of RHD-like intron 4. The
introns 4 of type 1 have a length similar to that of human RHD intron 4, whereas
introns 4 of type 2 display an insertion of 12 bp. The latest insertion was not
found in the human genome (72 individuals tested). The study of RH intron 3
length polymorphism confirmed that, like humans, chimpanzees and gorillas possess
two types of intron 3, with the RHD-type intron 3 being 289 bases shorter than
the RHCE intron 3. By amplification and sequencing of regions encompassing
introns 3 and 4, we demonstrated that chimpanzee and gorilla RH-like genes
displayed associations of introns 3 and 4 distinct to those found in man.
Altogether, the results demonstrate that, as in humans, chimpanzee and gorilla RH
genes experienced intergenic exchanges.
PMID- 10666713
TI - Pattern of morphological diversification in the Leptocarabus ground beetles
(Coleoptera: Carabidae) as deduced from mitochondrial ND5 gene and nuclear 28S
rDNA sequences.
AB - Most of the mitochondrial NADH dehydrogenase subunit 5 (ND5) gene and a part of
nuclear 28S ribosomal RNA gene were sequenced for 14 species of ground beetles
belonging to the genus Leptocarabus. In both the ND5 and the 28S rDNA
phylogenetic trees of Leptocarabus, three major lineages were recognized: (1) L.
marcilhaci/L. yokoael/Leptocarabus sp. from China, (2) L. koreanus/L.
truncaticollis/L. seishinensis/L. semiopacus/L. canaliculatus/L. kurilensis from
the northern Eurasian continent including Korea and Hokkaido, Japan, and (3) all
of the Japanese species except L. kurilensis. Clustering of the species in the
trees is largely linked to their geographic distribution and does not correlate
with morphological characters. The species belonging to different species groups
are clustered in the same lineages, and those in the same species group are
scattered among the different lineages. One of the possible interpretations of
the present results would be that morphological transformations independently
took place in the different lineages, sometimes with accompanying parallel
morphological evolution, resulting in the occurrence of the morphological species
belonging to the same species group (= type) in the different lineages.
PMID- 10666714
TI - The evolution of vertebrate antigen receptors: a phylogenetic approach.
AB - Classical T cells, those with alpha beta T-cell receptors (TCRs), are an
important component of the dominant paradigm for self-nonself immune recognition
in vertebrates. alpha beta T cells recognize foreign peptide antigens when they
are bound to MHC molecules on the surfaces of antigen-presenting cells. gamma
delta T cells bear a similar receptor, and it is often assumed that these T cells
also require specialized antigen-presenting molecules for immune recognition,
which we term "indirect antigen recognition." B-cell receptors, or
immunoglobulins, bind directly to antigens without the help of a specialized
antigen-presenting molecule. Phylogenetically, it has been assumed that T-cell
receptors and the genes that encode them are a monophyletic group, and that
"indirect" antigen recognition evolved before the split into two types of TCR.
Recently, however, it has been proposed that gamma delta-TCRs bind directly to
antigens, as do immunoglobulins (Ig's). This calls into question the null
hypothesis that indirect antigen recognition is a common characteristic of TCRs
and, by extension, the hypothesis that all TCR gene sequences form a monophyletic
group. To determine whether alternative explanations for antigen recognition and
other historical relationships among TCR genes might be possible, we performed
phylogenetic analyses on amino acid sequences of the constant and variable
regions which encode the basic subunits of TCR and Ig molecules. We used both
maximum-parsimony and genetic distance-based methods and could find no strong
support for the hypothesis of TCR monophyly. Analyses of the constant region
suggest that TCR gamma or delta sequences are the most ancient, implying that the
ancestral immune cell was like a modern gamma delta T cell. From this gamma delta
like ancestor arose alpha beta T cells and B cells, implying that indirect
antigen recognition is indeed a derived property of alpha beta-TCRs. Analyses of
the variable regions are complicated by strong selection on antigen-binding
sequences, but imply that direct antigen binding is the ancestral condition.
PMID- 10666715
TI - A comparison of estimators of the population recombination rate.
AB - Three new estimators of the population recombination rate C = 4Nr are introduced.
These estimators summarize the data using the number of distinct haplotypes and
the estimated minimum number of recombination events, then calculate the value of
C that maximizes the likelihood of obtaining the summarized data. They are
compared with a number of previously proposed estimators of the recombination
rate. One of the newly proposed estimators is generally better than the others
for the parameter values considered here, while the three programs that calculate
maximum-likelihood estimates give conflicting results.
PMID- 10666716
TI - Correlations among amino acid sites in bHLH protein domains: an information
theoretic analysis.
AB - An information theoretic approach is used to examine the magnitude and origin of
associations among amino acid sites in the basic helix-loop-helix (bHLH) family
of transcription factors. Entropy and mutual information values are used to
summarize the variability and covariability of amino acids comprising the bHLH
domain for 242 sequences. When these quantitative measures are integrated with
crystal structure data and summarized using helical wheels, they provide
important insights into the evolution of three-dimensional structure in these
proteins. We show that amino acid sites in the bHLH domain known to pack against
each other have very low entropy values, indicating little residue diversity at
these contact sites. Noncontact sites, on the other hand, exhibit significantly
larger entropy values, as well as statistically significant levels of mutual
information or association among sites. High levels of mutual information
indicate significant amounts of intercorrelation among amino acid residues at
these various sites. Using computer simulations based on a parametric bootstrap
procedure, we are able to partition the observed covariation among various amino
acid sites into that arising from phylogenetic (common ancestry) and stochastic
causes and those resulting from structural and functional constraints. These
results show that a significant amount of the observed covariation among amino
acid sites is due to structural/functional constraints, over and above the
covariation arising from phylogenetic constraints. These quantitative analyses
provide a highly integrated evolutionary picture of the multidimensional dynamics
of sequence diversity and protein structure.
PMID- 10666717
TI - Polymorphism and divergence in the beta-globin replication origin initiation
region.
AB - DNA sequence polymorphism and divergence was examined in the vicinity of the
human beta-globin gene cluster origin of replication initiation region (IR), a
1.3-kb genomic region located immediately 5' of the adult-expressed beta-globin
gene. DNA sequence variation in the replication origin IR and 5 kb of flanking
DNA was surveyed in samples drawn from two populations, one African (from the
Gambia, West Africa) and the other European (from Oxford, England). In these
samples, levels of nucleotide and length polymorphism in the IR were found to be
more than two times as high as adjacent non-IR-associated regions (estimates of
per-nucleotide heterozygosity were 0.30% and 0.12%, respectively). Most
polymorphic positions identified in the origin IR fall within or just adjacent to
a 52-bp alternating purine-pyrimidine ((RY)n) sequence repeat. Within- and
between-populations divergence is highest in this portion of the IR, and
interspecific divergence in the same region, determined by comparison with an
orthologous sequence from the chimpanzee, is also pronounced. Higher levels of
diversity in this subregion are not, however, primarily attributable to slippage
mediated repeat unit changes, as nucleotide substitution contributes
disproportionately to allelic heterogeneity. An estimate of helical stability in
the sequenced region suggests that the hypervariable (RY)n constitutes the major
DNA unwinding element (DUE) of the replication origin IR, the location at which
the DNA duplex first unwinds and new strand synthesis begins. These findings
suggest that the beta-globin IR experiences a higher underlying rate of neutral
mutation than do adjacent genomic regions and that enzyme fidelity associated
with the initiation of DNA replication at this origin may be compromised. The
significance of these findings for our understanding of eukaryotic replication
origin biology is discussed.
PMID- 10666718
TI - Weighted neighbor joining: a likelihood-based approach to distance-based
phylogeny reconstruction.
AB - We introduce a distance-based phylogeny reconstruction method called "weighted
neighbor joining," or "Weighbor" for short. As in neighbor joining, two taxa are
joined in each iteration; however, the Weighbor criterion for choosing a pair of
taxa to join takes into account that errors in distance estimates are
exponentially larger for longer distances. The criterion embodies a likelihood
function on the distances, which are modeled as correlated Gaussian random
variables with different means and variances, computed under a probabilistic
model for sequence evolution. The Weighbor criterion consists of two terms, an
additivity term and a positivity term, that quantify the implications of joining
the pair. The first term evaluates deviations from additivity of the implied
external branches, while the second term evaluates confidence that the implied
internal branch has a positive branch length. Compared with maximum-likelihood
phylogeny reconstruction, Weighbor is much faster, while building trees that are
qualitatively and quantitatively similar. Weighbor appears to be relatively
immune to the "long branches attract" and "long branch distracts" drawbacks
observed with neighbor joining, BIONJ, and parsimony.
PMID- 10666719
TI - Did the mitochondrial processing peptidase evolve from a eubacterial regulator of
gene expression?
PMID- 10666720
TI - A mitochondrial ancestry of the hydrogenosomes of Nyctotherus ovalis.
PMID- 10666721
TI - [De novo cancer and adenoma-carcinoma sequence of the colorectum-
clinicopathological differences between de novo carcinoma and carcinoma with the
sequence].
AB - The adenoma-carcinoma sequence ("The great majority of colorectal carcinomas
arises from adenomas") proposed by Morson et al (1972) has been generally
accepted world wide. Considering the sequence from the viewpoint of human
carcinogenesis in general, however, a few contradictions and mysterious phenomena
are found in the development and growth process of the colorectal carcinomas. It
is evident that the histogenesis of the adenoma-carcinoma sequence including such
contradictions is logically false. Consequently, we should fundamentally
reconsider the histogenesis of colorectal carcinoma. The premise for the
induction of the histogenesis of colorectal carcinoma is that carcinomas are much
more objectively differentiated from adenomas with severe atypia, and that
hyperplastic glands with slight atypia are differentiated from adenomas with
slight atypia. In order to objectify the histological interpretation of atypical
grades, conversion of complicated histological designs into real numbers is
required. Two discriminant functions with two variables (N/C ratio and density of
tubuli in a unit area) for differentiating carcinoma from adenoma have been
determined using computed image processing. Based on the discriminant functions
for differentiating objectively between carcinoma, adenoma, and hyperplasia, the
histogenesis of colorectal carcinomas has been deduced as follows: 70-80% of
colorectal carcinomas arise from the colorectal mucosa (de novo carcinoma) and 20
30% arise from adenoma. Observing the various clinicopathological phenomena in
colorectal adenomas and carcinomas from the viewpoint of histogenesis, the
contradictions do not enter the logically constructed model. Furthermore, the
biological behavior of de novo carcinoma is clinicopathologically different from
that of carcinoma with the sequence.
PMID- 10666722
TI - [Endoscopic mucosal resection].
AB - Endoscopic mucosal resection (EMR) is a widely used and important technique for
the treatment of colorectal neoplasms. The choice must be made between EMR and
surgical resection in treating submucosal invading carcinoma. Our study suggests
that EMR may be adapted to the treatment of sm1a and sm1b carcinoma without
invading vessels. Endoscopic findings suggestive of submucosal invasion are
depressed-type tumor, large size, hardness, ulceration on the top of the lesion,
etc. We have conducted studies on the surface structure of colorectal neoplasms
(pit pattern) and showed that pit patterns are useful in the qualitative and
quantitative diagnosis of lesions, when employing magnifying endoscopy. The VN
type pit pattern indicates that the lesion is most likely sm-massive cancer. This
type of cancer should not be treated by EMR. Although minute colorectal cancer
can be treated by EMR. We believe that the importance of endoscopic diagnosis and
treatment will increase.
PMID- 10666723
TI - [Usefulness of endoscopic polypectomy in early colorectal cancer].
AB - This study was carried out to clarify the usefulness of endoscopic polypectomy in
early colorectal cancer. Six hundred and sixty-four patients with polypectomized
early colorectal cancer were compared with 89 who underwent surgical resection.
Among the polypectomized patients, 361 had pedunculated (Ip)-type, 255 semi
pedunculated (Isp)-type, and 48 sessile (Is)-type cancer. The early colorectal
cancer was submucosal-invasive cancer (sm cancer) in 16.1% of Ip, 19.2% of I sp,
and 22.9% of Is patients. Among the surgically resected patients, sm cancer was
present in 41.2% of Ip. 62.1% of I sp. and 58.1% of Is patient in. The percentage
of sm cancer and the tumor size surgically resected patients were greater than in
polypectomized patients. Local recurrence and distant metastases were
investigated after endoscopic polypectomy during follow-up. Two cases (0.4%) of
local recurrence were detected after polypectomy among 555 patients with mucosal
cancer. Twenty-three (19.8%) of 116 patients with sm cancer underwent surgical
resection after polypectomy due to cancer invasion into the vessels and/or
extension to the resected margin recognized in polypectomized specimens. Only one
case (0.9%) of local recurrence and no distant metastases were detected after
polypectomy in 116 patients with sm cancer. Endoscopic polypectomy is very useful
as a minimally invasive surgical technique in the protruding type of early
colorectal cancer.
PMID- 10666724
TI - [Transanal endoscopic microsurgery (TEM)].
AB - Minimally invasive surgery is mandatory for rectal tumors to reduce surgical
complications and to improve the quality of life. The conventional transanal
procedure is one from of minimally invasive surgery for rectal tumors, but it is
still often difficult to reach the middle and upper thirds of the rectum due to
anatomical characteristics. Transanal endoscopic microsurgery (TEM) is a
technique that allows radical resection of rectal tumors in the distal as well as
proximal third of the rectum. Performing radical surgery using this technique
requires preoperative estimation of tumor extension both histologically and by X
ray images. It should allow provide safe and radical excision of rectal tumors.
In our department, patients with rectal tumors are evaluated for risk factors
using barium enema, endoscopic ultrasound, punch biopsy, etc. Fifty patients
(rectal cancer, 34: cartinoid, 4: adenoma, 12) have undergone radical TEM. The
operation was converted to open surgery in 2 cases because of rectal perforation.
Radical open surgery was performed after TEM in 1 patient since cancer invasion
was revealed by postoperatively upon histological examination. We conclude that
TEM is a useful technique for radical resection of rectal tumors and is
associated with a low rate of postoperative complications and a high surgical
success rate.
PMID- 10666725
TI - [Minimally invasive transanal surgery].
AB - A new anal retractor connected to an Octopus retractor holder and automatic
suture clamp were used for local excision of rectal tumors to obtain easy access
to proximal tumors with an adequate surgical field and to avoid complications.
Shortening techniques and invagination techniques were adopted to pull down
proximal tumors. This surgical procedure resulted in shorter operating time, less
bleeding, earlier oral intake, shorter hospital stay, and fewer complications.
PMID- 10666726
TI - [Laparoscopic bowel resection for early colon cancer].
AB - Following the successful introduction of laparoscopic cholecystectomy, many
reports confirming the feasibility of using laparoscopy for bowel resection and
predicting that it would be advantageous in terms of its minimal invasiveness
have been published. In the context of cancer treatment, however, the feasibility
of lymphadenectomy, the risk of recurrence, and survival have emerged as major
concerns. Even though mucosal cancer (Tis) can be treated by endoscopic resection
(ER), when this is not possible open surgery (OS) must be performed. In patients
with T1 cancer, tumors showing slight submucosal layer invasion (sm 1) can be
treated in the same way as Tis (in cancer) cancers. But 5% to 10% of patients
with T1 cancer have massive submucosal layer invasion (sm 2-3) with paracolic
lymph node metastasis. At least partial bowel resection with paracolic
lymphadenectomy is considered necessary for T1 (sm 2-3) cancers in principle. In
summary, laparoscopic local excision of Tis cancers that are endoscopically
unresectable and laparoscopically assisted partial resection with paracolic
lymphadenectomy for T1 cancers have become accepted because local excision and
partial resection with paracolic lymphnedectomy are fairly simple to perform
laparoscopically. Therefore as a strategy for the treatment of early colorectal
cancer (CRC), minimally invasive laparoscopic bowel resection (LBR) has been
positioned between endoscopic resection (ER) and open surgery (OS). While the
difficulty of performing radical lymphadenectomy is considered one of the
greatest obstacles to the introduction of laparoscopic bowel resection (LBR) for
the treatment of advanced colorectal cancer (CRC), early colon cancer is a good
indication for laparoscopic bowel resection.
PMID- 10666727
TI - [Laparoscopic surgery for early rectal carcinoma].
AB - The indications, techniques, and results of laparoscopic surgery for early rectal
carcinoma are described in detail. Laparoscopic surgery is indicated when a
mucosal tumor is too large to perform endoscopic or transanal resection or the
tumor invades the submucosal layer. When the tumor is located in the Rs or Ra
region, surgery can be completed laparoscopically. After dissection of the
mesenterium and lymphadenectomy are performed, the anal side of the rectum is
divided using EndoGIA II. When the tumor is located in the Rb portion, it is
impossible to resect the rectum intracorporeally. In this situation, aperi anal
maneuver is essential. The rectal mucosa is circumferentially incised just above
the dentate line and the internal anal sphincter is dissected. Dissection is
advanced to the intersphincteric space. Dissection between the rectum and the
levator ani muscle is completed, and the rectum is pulled through the anus. After
the oral side of the rectum is divided, a J-pouch is mase and J-pouch-anal
anastomosis is performed. Forty-seven patients with rectal carcinoma were
operated upon laparoscopically. Postoperative recovery was better than that after
open surgery. Serious intraoperative or postoperative complications have not been
encountered in this series. In conclusion, laparoscopic surgery is thought to be
the procedure of first choice for early rectal carcinoma.
PMID- 10666728
TI - [First successful bilateral living-donor lobar lung transplantation in Japan].
AB - No successful lung transplantation has been reported in Japan until recently when
we performed the first successful bilateral living-donor lobar lung
transplantation. A 24-year-old woman with primary ciliary dyskinesia began
experiencing severe respiratory insufficiency and required mechanical
ventilation. On October 28, 1998, she underwent bilateral living-donor lobar
transplantation, receiving her sister's lower right lobe and her mother's left
lower lobe under cardiopulmonary bypass. The patient was discharged from the
hospital 61 days after transplantation. Six months postoperatively, she has
returned to normal life and is able to carry out daily activities. She is in good
physical condition with a vital capacity of 1.77 L.
PMID- 10666729
TI - [Treatment of an iliac artery pseudoaneurysm managed with a stent graft].
AB - Recent developments have extended the indications for endovascular intervention
to include endovascular lesions, such as aneurysms and sclerotic arterioocclusive
disease. Although conventional treatment of pseudoaneurysms is mainly surgical
intervention, the development of stent grafts has made this treatment less
invasive than previously. We placed a stent graft in a pseudoaneurysm of the
iliac artery with good results, as described in this report. Treatment of a
pseudoaneurysm with a stent graft avoids the risk associated with general
anesthesia and reduces surgical invasiveness, similar to laparotomy. We expect
that this therapeutic mode will be developed further in the future.
PMID- 10666730
TI - [Experience of orthotopic liver transplantation from non-heart-beating donors at
the University of Pittsburgh Medical Center].
AB - Eight cases of orthotopic liver transplantation (OLT) from non-heart-beating
donors (NHBDs) were experienced at the University of Pittsburgh Medical Center.
Four cases were from donors whose organs were procured following cardiopulmonary
resuscitation (uncontrolled NHBD), and the remaining four hepatic allografts were
recovered after sustained cardiopulmonary arrest following extubation in an
operating room (controlled NHBD). After OLT from uncontrolled NHBDS, two
allografts failed due to preservation injury and hepatic arterial thrombosis, and
one showed poor allograft function. In contrast, all four grafts from controlled
NHBDs survived and functioned well worked postoperatively. Hepatic allografts
from controlled NHBDs is considered to be useful in OLT, especially in Japan
where there is a serious brain-dead donor shortage.
PMID- 10666731
TI - [Stereotactic neurosurgery for movement disorders].
PMID- 10666732
TI - [Electrophysiological mapping of the trigeminal nerve root during microvascular
decompression for trigeminal neuralgia].
AB - A method for intraoperative electrophysiological mapping of the intracranial root
of the trigeminal nerve was studied in five patients with trigeminal neuralgia.
During surgery, the trigeminal nerve root was stimulated centrally with a bipolar
electrode, and antidromic responses were recorded peripherally from three
branches of the trigeminal nerve in the face. In all patients, the fibers of the
individual subdivisions of the trigeminal nerve root were successfully localized
based on the peripheral sites of antidromic response. This neural mapping was
used during microvascular decompression in four patients and during a rhizotomy
procedure in one patient. As a result of mapping, the fibers of the trigeminal
division subserving the pain were clearly confirmed to be compressed by the
artery in all four patients who were undergoing microvascular decompression.
Likewise, the antidromic responses precisely identified the first division of the
trigeminal nerve, which should be preserved to avoid postoperative corneal ulcers
in patients undergoing rhizotomy. Based on these findings, it was concluded that
this technique enables surgeons to precisely identify which fibers of the
trigeminal nerve root should be decompressed or divided during surgery for
trigeminal neuralgia.
PMID- 10666733
TI - [Epilepsy surgery for focal cortical dysplasia and dysembryoplastic
neuroepithelial tumor].
AB - We studied six patients with focal cortical dysplasia (CD) and four patients with
dysembryoplastic neuroepithelial tumor (DNT) who had surgical resection for
medically intractable epilepsy. In all CD patients, ictal single photon emission
computed tomography (SPECT) using 99mTc-ECD revealed hyperperfusion in the
regions where magnetic resonance (MR) imaging showed CD abnormalities. Interictal
epileptiform activity and ictal seizure onset on electrocorticography using
subdural strip or grid electrodes were demonstrated in the CD itself. In
contrast, in all DNT patients, interictal SPECT disclosed hypoperfusion in the
area of the lesions. Ictal SPECT in one DNT patient disclosed hyperperfusion in
the superior area of the region where MR imaging showed cystic abnormalities.
Interictal spiking in all DNT patients and ictal seizure onset in two DNT
patients were demonstrated not in the lesions themselves but in the distinct zone
from the region of the tumor-involved brain. All CD patients who underwent
lesionectomy became seizure-free with a mean follow-up period of 33.5 months. All
DNT patients who underwent lesionectomy and resection of the epileptogenic cortex
became seizure-free or had their seizure significantly reduced a mean follow-up
period of 41.5 months. We conclude that CDs have intrinsic epileptogenicity,
while DNTs have epileptogenicity not intrinsically but in encompassed cortical
surface areas.
PMID- 10666734
TI - [An ultrasonic study of the relationship between extracranial carotid
atherosclerosis and intracerebral hemorrhage].
AB - We have evaluated the relationship between carotid atherosclerotic change and
intracerebral hemorrhage patients. Forty-eight patients with intracerebral
hemorrhage treated at our institution were included in this study. Their ages
ranged from 38 to 86 years old (average: 61.5 years). There were 28 cases of
putaminal hemorrhage and 20 cases of thalamic hemorrhage. Evacuation of hematoma
or ventricle drainage was performed in 18 cases within 3 days after the onset of
symptoms. The outcome in these cases was that 40 patients survived and 8 patients
died. Carotid atherosclerosis was evaluated by B mode-ultrasonography. The
severity of carotid atherosclerosis was assessed by using two indicators;
incidence of carotid atherosclerosis and maximum percentage diameter of the
stenosis. Carotid atherosclerosis on B mode-ultrasonography was detected more
frequently in patients with thalamic hemorrhage (84.2%) than in those with
putaminal hemorrhage (51.7%). Maximum percentage stenosis of thalamic hemorrhage
(17.2 +/- 15.2%) was higher than maximum percentage stenosis of putaminal
hemorrhage (6.4 +/- 9.7%). In conclusion, carotid atherosclerosis was an
effective indicator of not only ischemical cerebrovascular disease but also of
intracerebral hemorrhage.
PMID- 10666735
TI - [Spinal dermoid cyst secondary to myelomeningocele repair: a case report].
AB - Dermoid and epidermoid tumors arise from the invagination of epidermal elements
into the neural tube during the embryonic period. However, many studies have
reported that dermoid and epidermoid tumors occur 5 to 10 years after the first
operation on myelomeningocele patients. A seven-year-old male with
myelomeningocele which had been repaired in his neonatal period, presented leg
pain and deterioration of gait disturbance and urinary incontinence.
Neuroradiological examinations revealed a spinal dermoid cyst at the repaired
myelomeningocele and tethered spinal cord. We removed the tumor and untethered
the tethered spinal cord. Postoperatively, the patient's leg pain, gait
disturbance and urinary incontinence improved immediately. Inappropriate surgical
treatment of spina bifida may cause a second lesion, which leads to tethered-cord
syndrome. We suggest that proper surgical treatment, early checkup and
neuroradiological evaluations are very important for spina bifida patients who
show signs of neurological deterioration. For the best treatment, neurological,
urological and orthopedical follow-up study after the first repair operation is
necessary.
PMID- 10666736
TI - [A case of rete mirabile with congenital dysplasia of bilateral internal carotid
arteries].
AB - We report a case of dysplasia of the congenital bilateral internal carotid
arteries with the rete mirabile. The rete mirabile is not usually seen in the
course of human growth, but it is a common finding in other mammals. Accordingly,
some investigators have thought that the rete mirabile is "developmental shift".
Our case has dysplasia of the bilateral internal carotid arteries (one is aplasia
and the other is hypoplasia), but the patient had suffered from no ischemic
symptom because her brain had been sufficiently fed by each of the rete mirabile.
Angiographically, the frequency of the rete mirabile formation is about 1/10,000.
There were 20 cases reported until 1997 (including our case). There were 5 cases
(27.8%) with ischemic symptoms in spite of internal carotid artery dysplasia, 2
cases (11.1%) with intracerebral hemorrhage, 6 cases (33.3%) with subarachnoid
hemorrhage (there were only two cases with aneurysm) and 5 cases without
symptoms. We have tried to class the rete mirabile by angiographical findings.
One is the M type finding resembling moyamoya vessels in stages 3 & 4 of moyamoya
disease, and the other is the N type finding resembling a nidus of arteriovenous
malformation. M type occurred in younger patients more often than N type, so M
type may be the previous stage of N type.
PMID- 10666737
TI - [Successful treatment using detachable coils for traumatic carotid cavernous
fistula as a complication of transsphenoidal surgery for a pituitary adenoma: a
case report].
AB - We report a case of a patient with traumatic carotid cavernous fistula (CCF)
caused by transnasal-transsphenoidal surgery, who was successfully treated using
detachable coils. A 47-year-old man was admitted to our hospital because of
severe headache. He was confirmed to have a nonfunctioning pituitary adenoma with
presellar-type sphenoid sinus. Cerebral angiography initially disclosed no
vascular lesions. A transnasal-transsphenoidal adenomectomy was performed. When
the anterior wall of the sphenoid sinus was dissected with a chisel, the chisel
deeply stuck into the posterolateral part of the sinus. Profuse arterial bleeding
was observed through the sphenoid sinus. The bleeding was stopped easily by
compression and packing with bone wax. The operation was continued, the sellar
floor was opened widely and the tumor was removed subtotally. The medial wall of
the cavernous sinus was intact. Histological examination revealed a pituitary
adenoma. Immediately after surgery, the patient noticed a bruit. He developed
chemosis and abducent palsy on the right side. Cerebral angiography displayed a
high-flow CCF, which was attributed to the carotid artery injury caused by the
transnasal-transsphenoidal surgery. The CCF disappeared after two-staged
embolization using detachable coils, 1st transvenous and 2nd transarterial. Ten
months later, cerebral angiography showed persistent occlusion of the fistula,
and the patient experienced no tumor recurrence. It is suggested that drilling is
a safer procedure than using a chisel for dissection of a sphenoid sinus with
incomplete pneumatization. Endovascular treatment using detachable coils proved
useful to manage the CCF, an unusual complication of transsphenoidal surgery.
PMID- 10666738
TI - [Chronic subdural hematoma associated with malignancy: report of three cases].
AB - Three cases of chronic subdural hematoma (CSH) associated with malignancy are
reported. Case 1; A one-year-old girl was referred for vomiting and convulsions.
Left CSH was removed, and her symptoms disappeared. Cytological examination of
chronic subdural hematoma revealed abnormal white blood cells. A clinical
diagnosis of acute monocytic leukemia was made after the laboratory examination.
Remission was achieved by chemotherapy, but she died one year after the
operation. Case 2; A 72-year-old woman was referred for right hemiparesis and
urinary incontinence. Left CSH was irrigated, and her clinical symptoms
immediately disappeared. Cytological examination of chronic subdural hematoma
revealed abnormal white blood cells. A clinical diagnosis of chronic lymphocytic
leukemia was made after the laboratory examination. No treatment was given since
there were no clinical symptoms of chronic lymphocytic leukemia. Case 3; A 70
year-old woman who had been affected with early gastric cancer and mammary cancer
for the previous two years was admitted to our clinic because of headache, right
hemiparesis and consciousness disturbance. Left CSH was irrigated, and her
clinical symptoms improved. However, there was a tendency to bleed because
disseminated intravascular coagulation had occurred, and CT showed bilateral
subdural hematoma. A second irrigation was performed, but her symptoms did not
improve. Left acute subdural hematoma, which was removed by craniotomy, occurred
three days after the second operation. Pathological examination of the outer
membrane of the subdural hematoma revealed invasion of adenocarcinoma. She died
three days after the third operation. It is recommended that both the cytological
and the histological examinations be performed when possible, since they are
simple to perform and very useful in some cases.
PMID- 10666739
TI - [A case of spontaneous cervical carotid artery dissection managed by using
primary stent placement].
AB - The authors report the case of a 35-year-old male who underwent stenting for
spontaneous cervical carotid dissection. He presented with sudden onset of
hemicrania and left facial palsy followed by left hemiparesis and dysarthria. On
admission, carotid angiography revealed postsinus tapering occlusion of the right
internal carotid artery. Initially, he was managed with conservative treatment,
but his neurological status deteriorated. Findings of brain CT, MRI and IMP-SPECT
suggested hypoperfusion of the right cerebrum. A Palmaz stent, 39 mm in length,
was successfully placed over the site of the dissection to restore normal patency
through the dissected carotid artery. Following stent implantation, his
neurological signs improved gradually but completely. Since the procedure, with
oral administration of antiplatelet medication, he has suffered no cerebral
ischemic events. Follow-up carotid angiography one year after stent implantation
showed good patency of the stented segment. The present case emphasizes the
usefulness of stenting for spontaneous cervical carotid dissection.
PMID- 10666740
TI - Chemical reduction of phosphate on the primitive earth.
AB - If phosphorus played a role in the origin of life, some means of concentrating
micromolar levels of phosphate (derived from the calcium phosphate mineral
apatite), must first have been available. Here we show that simulated
(mini)lightning discharges in model prebiotic atmospheres, including only
minimally reducing ones, reduce orthophosphates, including apatite, to produce
substantial yields of phosphite. Electrical discharges associated with volcanic
eruptions could have provided a particularly suitable environment for this
process. Production of relatively soluble and reactive phosphite salts could have
supplied a pathway by which the first phosphorus atoms were incorporated into
(pre)biological systems.
PMID- 10666741
TI - Clay catalysis of oligonucleotide formation: kinetics of the reaction of the 5'
phosphorimidazolides of nucleotides with the non-basic heterocycles uracil and
hypoxanthine.
AB - The montmorillonite clay catalyzed condensation of activated monocleotides to
oligomers of RNA is a possible first step in the formation of the proposed RNA
world. The rate constants for the condensation of the phosphorimidazolide of
adenosine were measured previously and these studies have been extended to the
phosphorimidazolides of inosine and uridine in the present work to determine of
substitution of neutral heterocycles for the basic adenine ring changes the
reaction rate or regioselectivity. The oligomerization reactions of the 5'
phosphoromidazolides of uridine (ImpU) and inosine (ImpI) on montmorillonite
yield oligo(U)s and oligo(I)s as long as heptamers. The rate constants for
oligonucleotide formation were determined by measuring the rates of formation of
the oligomers by HPLC. Both the apparent rate constants in the reaction mixture
and the rate constants on the clay surface were calculated using the partition
coefficients of the oligomers between the aqueous and clay phases. The rate
constants for trimer formation are much greater than those dimer synthesis but
there was little difference in the rate constants for the formation of trimers
and higher oligomers. The overall rates of oligomerization of the
phosphorimidazolides of purine and pyrimidine nucleosides in the presence of
montmorillonite clay are the same suggesting that RNA formed on the primitive
Earth could have contained a variety of heterocyclic bases. The rate constants
for oligomerization of pyrimidine nucleotides on the clay surface are
significantly higher than those of purine nucleotides since the pyrimidine
nucleotides bind less strongly to the clay than do the purine nucleotides. The
differences in the binding is probably due to Van der Waals interactions between
the purine bases and the clay surface. Differences in the basicity of the
heterocyclic ring in the nucleotide have little effect on the oligomerization
process.
PMID- 10666742
TI - Oligomerization of deoxyguanosine 5'-phosphoro-2-methylimidazolide on a
polycytidylate template.
AB - The oligomerization of deoxyguanosine 5'-phosphoro-2-methylimidazolide on a
polycytidylate template is much less efficient than the oligomerization of the
corresponding activated ribonucleotide. Nonetheless oligomers containing up to
eight nucleotide residues are detected. The products are 3'-5'-linked
oligodeoxyribonucleotides capped at the 5'-terminus with a pyrophosphate-linked
monomer.
PMID- 10666743
TI - Scanning tunnelling microscopy and molecular modelling of xanthine monolayers
self-assembled at the solid-liquid interface: relevance to the origin of life.
AB - The development of scanning tunnelling microscopy (STM) has allowed examination
of inorganic crystalline surfaces and their interactions with organic adsorbates
with unparalleled resolution. As a novel technique in origin of life studies, the
application of STM is detailed with particular attention paid to the methods
employed in the analysis of organic monolayer structures. STM imaging and
molecular modelling of self-assembled monolayers of the purine base, xanthine,
formed on the surfaces of graphite and molybdenum disulfide are presented as an
example. The putative role of such structures in the origin of life is discussed.
PMID- 10666744
TI - Chirality amplification--the accumulation principle revisited.
AB - The chirality amplification mechanism proposed by Yamagata in 1966, relying on an
Accumulation Principle which involved the parity violating energy difference (1 +
epsilon) presumed to be operative at each step in the formation of a homochiral
biopolymer, is briefly surveyed historically. The Accumulation Principle is then
examined analytically and found to be incapable of producing a unique homochiral
polymer in any realistic polymerization process. The extension of the
Accumulation Principle to crystallizations which afford enantiomorphic crystals
is also scrutinized and found to be misapplied and invalid.
PMID- 10666745
TI - Did Viking discover life on Mars?
AB - A major argument in the claim that life had been discovered during the Viking
mission to Mars is that the results obtained in the Labeled Release (LR)
experiment are analogous to those observed with terrestrial microorganisms. This
assertion is critically examined and found to be implausible.
PMID- 10666746
TI - The subpectoral pulse generator site revisited.
PMID- 10666747
TI - Unexpected loss of bipolar pacing with implanted dual chamber pacemakers.
AB - Bipolar leads are most commonly used in the current practice of pacemaker
therapy. In our study of 124 patients implanted with Guidant/Cardiac Pacemakers
(CPI) Vigor dual chamber pacemakers, 5 patients had unexpectedly abrupt increases
in bipolar lead impedance and pacing threshold 2 weeks to 18 months
postimplantation without changes in sensing function. With the lead configuration
reprogrammed to unipolar, the lead impedance and pacing threshold were restored
to appropriate ranges. The changes in bipolar lead parameters can be caused by
the CPI's "Quick Connect" (QC1) header lead system incorporated in these
pacemakers.
PMID- 10666748
TI - Tissue temperatures and lesion size during irrigated tip catheter radiofrequency
ablation: an in vitro comparison of temperature-controlled irrigated tip
ablation, power-controlled irrigated tip ablation, and standard temperature
controlled ablation.
AB - The limited success rate of radiofrequency catheter ablation in patients with
ventricular tachycardias related to structural heart disease may be increased by
enlarging the lesion size. Irrigated tip catheter ablation is a new method for
enlarging the size of the lesion. It was introduced in the power-controlled mode
with high power and high infusion rate, and is associated with an increased risk
of crater formation, which is related to high tissue temperatures. The present
study explored the tissue temperatures during temperature-controlled irrigated
tip ablation, comparing it with standard temperature-controlled ablation and
power-controlled irrigated tip ablation. In vitro strips of porcine left
ventricular myocardium were ablated. Temperature-controlled irrigated tip
ablation at target temperatures 60 degrees C, 70 degrees C, and 80 degrees C with
infusion of 1 mL saline/min were compared with standard temperature-controlled
ablation at 70 degrees C and power-controlled irrigated tip ablation at 40 W, and
infusion of 20 mL/min. Lesion size and tissue temperatures were significantly
higher during all modes of irrigated tip ablation compared with standard
temperature-controlled ablation (P < 0.05). Lesion volume correlated positively
with tissue temperature (r = 0.87). The maximum recorded tissue temperature was
always 1 mm from the ablation electrode and was 67 +/- 4 degrees C for standard
ablation and 93 +/- 6 degrees C, 99 +/- 6 degrees C, and 115 +/- 13 degrees C for
temperature-controlled irrigated tip ablation at 60 degrees C, 70 degrees C, and
80 degrees C, respectively, and 112 +/- 12 degrees C for power-controlled
irrigated tip ablation, which for irrigated tip ablation was significantly higher
than tip temperature (P < 0.0001). Crater formation only occurred at tissue
temperatures > 100 degrees C. We conclude that irrigated tip catheter ablation
increases lesion size and tissue temperatures compared with standard ablation in
the temperature-controlled mode at the same or higher target temperatures and in
the power-controlled mode. Furthermore, tissue temperature and delivered power
are the best indicators of lesion volume during temperature-controlled ablation.
PMID- 10666749
TI - The first year experience with the dual chamber ICD.
AB - In July 1997, a dual chamber pacemaker combined with a tiered therapy implantable
cardioverter defibrillator (ICD) first became available in the United States. We
report the first-year experience of one center in the United States with this
dual chamber ICD. Of a total of 174 ICDs, 95 (55%) were dual chamber devices and
79 (45%) were single chamber. New dual chamber ICD insertions averaged 57.4 +/-
8.9 minutes, though there was a learning curve as the last 30 implants averaged
45.1 +/- 6.1 minutes with a negative slope to the regression line of procedure
duration (-0.52, P < 0.05). New single chamber ICD implants were 18.5 minutes
quicker (38.9 +/- 7.2 minutes). The most challenging implants were dual chamber
upgrades (mean procedure duration 64.9 +/- 15.8 minutes), especially if there was
a previously implanted pacemaker and ICD at separate sites. Indications for a new
dual chamber device were grouped into classic pacemaker indications (52.5%),
which comprised the Class I ACC/AHA guidelines, ICD-specific indications (24.6%),
and other (23.0%). In the 34 patients undergoing dual chamber upgrade, the
classic and ICD-specific groups were equal (47.0% each). Complications were rare
(2.8%), though 3 (8.8%) of 34 undergoing a dual chamber upgrade developed late
infections requiring explantation. In its first year, the dual chamber ICD has
become a common device at our institution comprising 55% of new implants. As
experience grows, we anticipate similar usage at most institutions.
PMID- 10666750
TI - Early heart rate variations during head-up tilt table testing as a predictor of
outcome of the test.
AB - Head-up tilt table testing (HUTT) is a useful tool for the diagnosis of unknown
origin of syncope. A setback is its duration. This study tries to establish a
specific parameter that, according to the heart rate elevation in the test's
initial phase, allows a reliable prediction of its outcome. In a prospective
study, every patient being under unknown syncope workup was included. A two-phase
20-minute tilt table test was performed. The initial phase was passive, and the
second required pharmacological stimulation with isoproterenol. The basal and 5-
and 10-minute heart rate values of the passive phase were measured and compared
within the group and against negative tests. During a 1-year period, 115 HUTT
were performed: 88 were positive and 27 negative. The negative HUTT patients had
an increase in HR of 5.05 (+/- 13.5) beats/min at 5 minutes, and 5.79 (+/- 12.9)
beats/min at 10 minutes (P = 0.2). Those with a positive HUTT had an increase of
9.05 (+/- 14.5) beats/min at 5 minutes, and of 10 (+/- 13.4) beats/min at 10
minutes (P < 0.001). There were no significant changes in HR when comparing
positive to negative HUTT. There is no specific number that allows predication of
outcome early in HUTT. Within the group, variations are important. Only a group
tendency can be established, which strongly correlates with the results obtained
during the test.
PMID- 10666751
TI - Importance of ventricular rate after mode switching during low intensity exercise
as assessed by clinical symptoms and ventilatory gas exchange.
AB - Automatic mode switching from DDD(R) to DDI(R) or VVI(R) pacing modes has
improved dual chamber pacing in patients at high risk for supraventricular
tachyarrhythmias. However, little is known about the effect of ventricular pacing
rate adaptation after mode switching. We conducted a single-blinded, crossover
study in 15 patients (58 +/- 21 years) with a DDD pacemaker who had AV block and
normal sinus node function to investigate the influence of pacing rate adaptation
to intrinsic heart rate during low intensity exercise. Patients performed two
tests (A/B) of low intensity treadmill exercise (0.5 W/kg) in randomized order.
They initially walked for 6 minutes while paced in DDD mode. The pacing mode was
then switched to VVI with a pacing rate of either 70 beats/min (test A) or
matched to the intrinsic heart rate (95 +/- 11 beats/min test B). Respiratory gas
exchange variables were determined and patients classified the effort before and
after mode switching on a Borg scale from 6 to 20. Percentage changes of
respiratory gas exchange measurements were significantly larger (O2 consumption:
8.2 +/- 5.0% vs. -0.6 +/- 7.2%; ventilatory equivalent of CO2 exhalation: 5.3 +/-
4.9% vs. 1.5 +/- 4.3%; respiratory exchange ratio: 7.0 +/- 2.2% vs. 3.5 +/- 3.0%;
end-tidal CO2: -5.7 +/- 2.9% vs. -1.8 +/- 2.7%; all P < 0.01) and the increase in
subjective assessment of the effort tended to be higher (mean increase on Borg
scale: 1.6 +/- 1.9 vs. 1.1 +/- 1.8, P = 0.07) after heart rate unadjusted than
after adjusted mode switching. Mode switching from DDD to VVI pacing is better
tolerated and gas exchange measurements are less influenced if ventricular pacing
rate is adjusted to the level of physical activity. Thus, pacing rate adjustment
should be considered as part of automatic mode switch algorithms.
PMID- 10666752
TI - Electrophysiological correlates of transmural linear ablation.
AB - The purpose of this study is to describe the characteristics of lesions created
using radiofrequency (RF) energy delivered through a saline/foam electrode that
is designed to simplify ablation of the isthmus between the tricuspid annulus
(TA) and the inferior vena cava (IVC). We compared the changes in the
electrophysiological parameters produced by the ablation to histological
findings. In search of a more practical and effective atrial flutter ablation
method, various energy modifications and catheter designs have been tested. It
was shown that the efficiency of RF ablation could be improved using an
endocardial cooled catheter; resulting in increased lesion size. Thus, we
postulate that a similar advantage of the cooled catheter system would allow
efficient RF delivery through specially designed long foam electrodes, therefore
improving the practicality of TA-IVC isthmus ablation for atrial flutter. The
study was performed in two acute and five subacute sheep under general anesthesia
and with adequate heparinization. We used a linear ablation catheter system
equipped with two 2-cm saline bipole electrode pockets with 1.5-mm separation,
each consisting of two 8-mm electrodes with 1-mm spacing, allowing for bipolar
pacing and recording. This saline/foam electrode pair were positioned on a
support loop. RF energy was applied to the saline electrodes at 50 watts for 90
seconds with a saline flow rate of 0.4 mL/s. Bipolar atrial signal amplitude and
pacing thresholds were measured before and after ablation. If necessary, the
catheter was pulled back and additional ablation was applied to any viable
tissue. Transisthmus ablations were created with a single catheter positioning in
five sheep using both saline electrodes in four and one electrode in the other.
Pullback and additional ablation to one saline electrode was required in two
sheep; in one after RF was delivered to only one electrode. After ablation,
atrial signal amplitude was reduced by an average of 76% (range 51%-92%) and its
pacing threshold was increased by an average of 617% (range 150%-400%).
Transmural lesions were found in all sheep, measuring 8-20 mm in length, 4-10 mm
in width, and 1.5-2.0 mm in depth. No charring, coagulum, or remote structural
damage was found in any preparation. Continuous transmural TA-IVC isthmus lesions
could be produced with stationary RF linear ablation using a saline/foam
electrode catheter system. This system allowed for assessment of
electrophysiological parameters that correlated with complete necrosis.
PMID- 10666753
TI - Long-term reproducibility of ventricular tachycardia induction with
electrophysiological testing in patients with coronary heart disease and
depressed left ventricular ejection fraction.
AB - The Multicenter Automatic Defibrillator Implantation Trial (MADIT) has recently
confirmed the role of programmed ventricular stimulation (PVS) to identify the
high risk patients of sudden death after myocardial infarction and to prevent
this risk. The purpose of this study was to evaluate the long-term
reproducibility of PVS in these patients. Thirty patients with coronary heart
disease without spontaneous documented sustained ventricular tachycardia (VT)
underwent two programmed stimulations in the absence of antiarrhythmic drug
treatment between 2 and 6 years (mean 4 years). No patient had a myocardial
infarction or intervening cardiac surgery during this period. The protocol of
study was similar using up to three extrastimuli in two sites of the right
ventricle, delivered in sinus rhythm and driven rhythm (600 ms, 400 ms,
respectively). On the first PVS, 17 patients had inducible sustained VT (group
I). Thirteen patients did not have inducible VT (group II). On the second PVS all
group I patients but one had inducible VT, but the cycle length was significantly
modified in 11. In group II, five patients had inducible VT and in the other
patients the PVS remained negative. In conclusion, in patients with coronary
heart disease, but without documented VT, the long-term reproducibility of PVS
was excellent in those with inducible VT (94%); the patients remain at risk of VT
and a prophylactic implantable cardioverter defibrillator could be considered. In
patients with initially negative study, reproducibility of PVS was lower (61.5%),
probably because of the progressive remodeling after myocardial infarction.
Therefore, the occurrence of new symptoms in patients with previously negative
study requires a second programmed ventricular stimulation.
PMID- 10666754
TI - The recording of monophasic action potentials with fractal-coated iridium
electrodes in humans.
AB - The present study was designed to evaluate the feasibility of the recording of
monophasic action potentials (MAP) with fractal-coated iridium electrodes in a
clinical setting. In 18 patients who underwent an electrophysiological study for
various arrhythmias, we performed MAP recordings with both 1.3-mm2 and 6-mm2 tip
surface area fractal-coated iridium and standard silver--silver chloride
(Ag/AgCl) electrodes in the high right atrium and two ventricular positions.
Amplitude and MAP duration at 90%, 50%, and 25% of repolarization were calculated
during steady-state pacing at 600, 500, and 400 ms cycle lengths with
extrastimuli application. Morphology comparisons of MAP signals recorded with
both types of electrodes were performed by regression analysis using 5% of the
repolarization segments of the MAP trajectory. Differences between MAP duration
at 90%, 50%, and 25% of repolarization recorded with fractal-coated and Ag/AgCl
electrodes were statistically insignificant. Amplitude values recorded with 6-mm2
tip electrodes were significantly smaller than those recorded with Ag/AgCl
electrodes for all comparisons. During steady-state pacing, the correlation
coefficients between Ag/AgCl and fractal-coated 1.3-mm2 and 6-mm2 tip electrodes
were within the range of 0.93-0.999 and 0.87-0.999, respectively. The correlation
of MAP amplitude and duration at 90%, 50%, and 25% of repolarization following
the extrastimulus S2, recorded with both types of electrodes, was significantly
weaker for right atrial recordings (r value range 0.78-0.92) as compared to
ventricular recordings (r value range 0.92-0.99). The MAP sensing features of
fractal-coated iridium and Ag/AgCl electrodes are comparable. The best results
for recording of MAPs with fractal-coated electrodes can be achieved with small
surface area tip electrodes.
PMID- 10666755
TI - Impact of transisthmus linear ablation of typical atrial flutter on coronary
sinus activation time.
AB - Complete or incomplete bidirectional isthmus conduction block after linear
ablation of atrial flutter is difficult to interpret without detailed multiple
electrodes mapping along the tricuspid annulus and the low right atrial isthmus
area. The influence of isthmus block on the intraatrial septal and coronary sinus
activation has not been assessed by endocardial mapping. This study was designed
to analyze the intraartial and interatrial activation times in a retrospective
fashion to investigate (1) whether isthmus conduction block can change the
coronary sinus activation sequence during low lateral right atrial pacing, and
(2) the correlation between change of coronary sinus activation time and isthmus
conduction block. Sixty-five consecutive patients (mean age, 57 +/- 18 years)
with clinically documented typical atrial flutter were studied. A 20-pole "Halo"
catheter was placed around the tricuspid annulus including the entire low right
atrial isthmus to verify complete bidirectional isthmus block. Activation time
from ostium to distal coronary sinus (OCS-->DCS), and interatrial septum and
isthmus activation times during right atrial pacing were analyzed and compared
before and after incomplete or complete isthmus block. Complete bidirectional
isthmus block was achieved in 50 (77%) patients. During low lateral right atrial
pacing, linear ablation at low right atrial isthmus results in a significant
delay of activation in all coronary sinus recording sites with greater extent at
the ostium area without influence on interatrial septum activation in complete
and incomplete isthmus conduction block. The difference of the OCS-->DCS interval
before and after ablation, delta (OCS-->DCS), was well correlated with results of
isthmus conduction block and significantly longer in patients with complete than
those with incomplete isthmus block (34 +/- 11 vs 11 +/- 8 ms, P < 0.001),
thereby allowing a value of 20 ms as a discriminative parameter to differentiate
incomplete (< 20 ms) from complete (> or = 20 ms) isthmus counterclockwise
conduction block with a sensitivity of 96% and a specificity of 88%. In
conclusion, creation of a line of block at the inferior vena cava-tricuspid
annulus isthmus could change coronary sinus activation sequence during low
lateral right atrial pacing in sinus rhythm. The change of coronary sinus
activation time after linear ablation, delta (OCS-->DCS), was well correlated
with isthmus conduction block by using a value > or = 20 ms to discern complete
counterclockwise isthmus block.
PMID- 10666756
TI - Preserving normal ventricular activation versus atrioventricular delay
optimization during pacing: the role of intrinsic atrioventricular conduction and
pacing rate.
AB - The purpose of the study was to compare the effects of DDD pacing with optimal AV
delay and AAI pacing on the systolic and diastolic performance at rest in
patients with prolonged intrinsic AV conduction (first-degree AV block). We
studied 17 patients (8 men, aged 69 +/- 9 years) with dual chamber pacemakers
implanted for sick sinus syndrome in 15 patients and paroxysmal high degree AV
block in 2 patients. Aortic flow and mitral flow were evaluated using Doppler
echocardiography. Study protocol included the determination of the optimal AV
delay in the DDD mode and comparison between AAI and DDD with optimal AV delay
for pacing rate 70/min and 90/min. Stimulus-R interval during AAI (ARI) was 282
+/- 68 ms for rate 70/min and 330 +/- 98 ms for rate 90/min (P < 0.01). The
optimal AV delay was 159 +/- 22 ms. AV delay optimization resulted in an increase
of an aortic flow time velocity integral (AFTVI) of 16% +/- 9%. At rate 70/min
the patients with ARI < or = 270 ms had higher AFTVI in AAI than in DDD (0.214 +/
0.05 m vs 0.196 +/- 0.05 m, P < 0.01), while the patients with ARI > 270 ms
demonstrated greater AFTVI under DDD compared to AAI (0.192 +/- 0.03 m vs 0.166
+/- 0.02 m, P < 0.01). At rate 90/min AFTVI was higher during DDD than AAI (0.183
+/- 0.03 m vs 0.162 +/- 0.03 m, P < 0.01). Mitral flow time velocity integral
(MFTVI) at rate 70/min was higher in DDD than in AAI (0.189 +/- 0.05 m vs 0.173
+/- 0.05 m, P < 0.01), while at rate 90/min the difference was not significant in
favor of DDD (0.149 +/- 0.05 m vs 0.158 +/- 0.04 m). The results suggest that in
patients with first-degree AV block the relative impact of DDD and AAI pacing
modes on the systolic performance depends on the intrinsic AV conduction time and
on pacing rate.
PMID- 10666757
TI - The comparative effects of drive and test stimulus intensity on myocardial
excitability and vulnerability.
AB - The number and intensity of stimuli that set basic cycle length in cardiac
electrophysiological studies can influence the electrical properties assessed by
extrastimuli. The relative contribution of drive (S1) and test (S2) stimulus
intensity in defining myocardial excitability and vulnerability has not been
reported. The purpose of this investigation was to assess this interaction and to
determine whether atrial and ventricular findings differed. The effects of S1 and
S2 intensity on atrial and ventricular stimulus-intensity-refractory-period
curves were determined in open-chest dogs: comparisons were made between curves
with S1 intensity varied between diastolic threshold (DT) and 10 mA and S2
intensity maintained at DT and those with S1 intensity maintained at DT and S2
intensity varied between DT and 10 mA. S1-S1 was held constant and S1-S2 varied.
The effects of different stimulation sites, cycle length, number of stimulations,
and neural blockade were assessed. S1 intensity amplification shifted atrial
stimulus-intensity-refractory period curves in the direction of increased
excitability and vulnerability; the changes were more pronounced than those
obtained by modulating S2 intensity. The changes produced by increasing S1
intensity were evident at different cycle lengths and were enhanced by an
increased number of stimulations, but were not evident when S1 and S2 were
delivered at different atrial sites. Although beta-blockade attenuated the
effects of increasing S1 intensity somewhat, the addition of cholinergic blockade
virtually abolished it. Ventricular refractoriness was also changed by modulation
of S1 intensity, but the changes were less striking. In the atrium, modulation of
S1 intensity has greater effects of stimulus-intensity-refractory-period
relations than modulation of S2 intensity; in the ventricule, the converse is
true.
PMID- 10666758
TI - Electrophysiologist-implanted transvenous cardioverter defibrillators using local
versus general anesthesia.
AB - With the advent of smaller biphasic transvenous implantable cardioverter
defibrillators (ICDs) and the experience gained over the years, it is now
feasible for electrophysiologists to implant them safely in the abdominal or
pectoral area without surgical assistance. Throughout the years, general
anesthesia has been used as the standard technique of anesthesia for these
procedures. However, use of local anesthesia combined with deep sedation only for
defibrillation threshold (DFT) testing might further facilitate and simplify
these procedures. The purpose of this study was to test the feasibility of using
local anesthesia and compare it with the standard technique of general
anesthesia, during implantation of transvenous ICDs performed by an
electrophysiologist in the electrophysiology laboratory. For over 4 years in the
electrophysiology laboratory, we have implanted transvenous ICDs in 90
consecutive patients (84 men and 6 women, aged 58 +/- 15 years). Early on,
general anesthesia was used (n = 40, group I), but in recent series (n = 50,
group II) local anesthesia was combined with deep sedation for DFT testing.
Patients had coronary (n = 58) or valvular (n = 4) disease, cardiomyopathy (n =
25) or no organic disease (n = 3), a mean left ventricular ejection fraction of
35%, and presented with ventricular tachycardia (n = 72) or fibrillation (n =
16), or syncope (n = 2). One-lead ICD systems were used in 74 patients, two-lead
systems in 10 patients, and an AVICD in 6 patients. ICDs were implanted in
abdominal (n = 17, all in group I) or more recently in pectoral (n = 73) pockets.
The DFT averaged 9.7 +/- 3.6 J and 10.2 +/- 3.6 J in the two groups, respectively
(P = NS) and there were no differences in pace-sense thresholds. The total
procedural duration was shorter (2.1 +/- 0.5 hours) in group II (all pectoral
implants) compared with 23 pectoral implants of group I (2.9 +/- 0.5 hours) (P <
0.0001). Biphasic devices were used in all patients and active shell devices in
67 patients; no patient needed a subcutaneous patch. There were six complications
(7%), four in group I and two in group II: one pulmonary edema and one
respiratory insufficiency that delayed extubation for 3 hours in a patient with
prior lung resection, both probably related to general anesthesia, one lead
insulation break that required reoperation on day 3, two pocket hematomas, and
one pneumothorax. There was one postoperative arrhythmic death at 48 hours in
group I. No infections occurred. Patients were discharged at a mean time of 3
days. All devices functioned well at predischarge testing. Thus, it is feasible
to use local anesthesia for current ICD implants to expedite the procedure and
avoid general anesthesia related cost and possible complications.
PMID- 10666759
TI - The genetics of cardiac arrhythmias.
PMID- 10666760
TI - Inappropriate antitachycardia pacing: a dangerous component failure or
pseudotherapy?
PMID- 10666761
TI - Short-, mid-, and long-term reproducibility of the atrial signal-averaged
electrocardiogram in healthy subjects: comparison with the conventional
ventricular signal-averaged electrocardiogram.
AB - Although atrial signal-averaged electrocardiogram (SAECG) has been proposed for
noninvasive identification of patients with atrial tachyarrhythmias, the
substantial variability of the measurement limits the clinical value. The aim of
the study was to assess the short- to long-term reproducibility of atrial SAECG
and to compare it to that of the conventional ventricular SAECG in 51 healthy
volunteers (30 men; age 32 +/- 8 years). In each subject, SAECG recordings were
obtained using MAC-VU electrocardiograph and HiRES and PHiRES software (Marquette
Medical Systems) and repeated after 5 minutes, 1 day, 1 week, and 1 month.
Automatically detected onset and offset of the filtered QRS complex and P wave
were subsequently corrected by two independent observers, and the averaged values
were used for the analysis. Conventional ventricular SAECG parameters: filtered
QRS duration (QRStot), low amplitude signal duration, and root mean square
voltage (RMS) of the terminal 40 ms of QRS, and 5 atrial parameters: filtered P
wave duration (Ptot), RMS of the terminal 40, 30, 20 ms, and of the entire P wave
were obtained. Relative errors of different pairs of measures were used to assess
the intrasubject reproducibility. QRStot and Ptot were the most reproducible
parameters. The relative errors after 5 minutes, 1 day, 1 week, and 1 month were
0.8% to 2.4% for QRStot, and 1.3% to 4.2% for Ptot. For RMS voltages, the
relative errors exceeded 15% in short-term and 20% in long-term recordings.
Although Ptot was statistically less reproducible than QRStot, the
reproducibility of the former was good and comparable to that of the QRStot. The
reproducibility of the voltage parameters was significantly poorer than that of
the duration parameters. The study showed a satisfactory short- and long-term
reproducibility of Ptot in the atrial SAECG in healthy subjects. However, low
reproducibility of the voltage parameters should be considered in clinical
applications.
PMID- 10666762
TI - The physician's office: now accrediting the environment of care....
PMID- 10666763
TI - Cisapride and torsades de pointes in a pacemaker patient.
PMID- 10666764
TI - Radiofrequency ablation of a posteroseptal atrioventricular accessory pathway in
a left-sided tricuspid ring with Ebsteinlike anomaly in a patient with
congenitally corrected transposition of the great arteries.
AB - Radiofrequency ablation successfully eliminated a posteroseptal accessory pathway
in a left-sided tricuspid ring with Ebsteinlike anomaly in a patient with a
congenitally corrected transposition of the great arteries.
PMID- 10666765
TI - Successful treatment of severe orthostatic hypotension with cardiac tachypacing
in dual chamber pacemakers.
AB - Orthostatic hypotension is an evolving and disabling disease usually observed in
elderly patients with dramatic consequences on morbidity, mortality, and
impairing the quality of life. We studied the effects of the pacing rate and AV
interval on the blood pressure drop in the upright position in two patients with
previously implanted pacemakers for sinus node dysfunction. Although the AV
interval did not affect the blood pressure drop in the upright position,
tachypacing at 100 paces/min improved it dramatically and prevented syncope.
Cardiac tachypacing is a useful therapeutic option in severe refractory
orthostatic hypotensive patients, especially those with chronotropic
incompetence.
PMID- 10666766
TI - Adenosine induced atrial fibrillation precipitating polymorphic ventricular
tachycardia.
AB - An 86-year-old female developed supraventricular tachycardia 36 hours after a
myocardial infarction (MI). She developed atrial fibrillation and polymorphic
ventricular tachycardia (PVT) following administration of 12 mg of adenosine. The
PVT caused hemodynamic instability with no response to cardioversion, but
termination with procainamide. The heart is vulnerable to hemodynamically
unstable, possibly lethal, PVT early after MI under some circumstances. This
vulnerability may be exposed following administration of adenosine. Extra caution
is warranted when using adenosine in the post-MI period.
PMID- 10666767
TI - Dual chamber pacemaker implantation via a double superior vena cava.
AB - We present the chest X ray of a woman with sinoatrial node disease. She has had a
dual chamber pacemaker implanted with each lead coursing through a separate
superior vena cava.
PMID- 10666768
TI - Pacing approaches to the patient with a univentricular heart and the factors
associated with choice of pacing site.
PMID- 10666769
TI - Natural and induced regulation of Th1/Th2 balance.
AB - Because Th1/Th2 balance is perturbed during immunological disease, the design of
strategies aiming at its rectification has become a priority. The alteration of
the balance in pregnancy so as to promote survival of the fetal allograft lends
credibility to this aim. Attenuation of the activation signal delivered through
the T cell receptor (TCR) represents a promising approach. It is supported by the
high level of polymorphism in the MHC class II promoter, which regulates the
natural TCR signal and thus modulates Th1/Th2 differentiation. Further support
comes from the Th2 shift that occurs in JNK knockout mice, and with kinase
inhibitors and anti-CD4 monoclonal antibodies applied in vitro. The approach has
implications for nasal tolerance and inhibition of IL-12 production. The further
range of options for Th1/Th2 modulation, which are presented throughout this
issue of the journal, are here summarised and evaluated.
PMID- 10666770
TI - Molecular mechanisms in T helper phenotype development.
PMID- 10666771
TI - Educating T cells: early events in the differentiation and commitment of cytokine
producing CD4+ and CD8+ T cells.
AB - T lymphocytes acquire the ability to synthesize cytokines during their primary
response to antigen, often giving rise to effector populations with a polarized
type 1 or type 2 cytokine profile. However, polarization is not a simple choice
between two differentiation pathways. This article reviews the evidence,
particularly from single-cell and clonal studies, that polarization is the
outcome of a series of stochastic events whose probabilities are determined in
part by genetic background and in part by extracellular signals received during
activation and clonal expansion. The data suggest that these extracellular
signals independently and differentially regulate the probability of expression
of each cytokine gene, for example by their effects on clonal expansion and
chromatin remodeling, CpG demethylation and transcriptional activation of
cytokine genes. Polarization is, therefore, achieved at the population level by
altering frequencies of expression among cells with many different expression
patterns, rather than by selective differentiation of a discrete subset. Type 1
and type 2 populations progressively lose responsiveness to counter-polarizing
stimuli. While the molecular basis of this process is not yet known, the observed
persistence of cells with flexible cytokine profiles in some polarized
populations suggests that loss of flexibility may also be a probabilistic event.
PMID- 10666772
TI - The critical role of IL-12 and the IL-12R beta 2 subunit in the generation of
pathogenic autoreactive Th1 cells.
AB - Experimental Allergic Encephalomyelitis (EAE) is a demyelinating disease of the
central nervous system which is an animal model for the human autoimmune disease,
multiple sclerosis. EAE is mediated by CD4+ T cells and the T cells responsible
for disease induction produce Th1 cytokines. IL-12 produced by monocytes and
dendritic cells is the most critical factor which influences the development and
differentiation of pathogenic autoreactive Th1 cells. Here, we review our recent
studies on the critical contributions of IL-12 and the IL-12R beta 2 subunit to
the generation of autoreactive effector cells which mediate EAE. In addition, we
discuss the potential contribution of IL-18 to the upregulation of the IL-12/IL
12R beta 2 pathway and the contribution of the suppressor cytokines, IL-4 and IL
10, in downregulating this pathway. Collectively, our studies demonstrate that
the IL-12/IL-12R beta 2 pathway is a critical intermediary in the process of Th1
differentiation which can be both positively or negatively regulated. This
pathway remains an attractive immunotherapeutic target for blockade of function
with inhibitory reagents or downregulation by Th2 cytokines.
PMID- 10666773
TI - Th1/Th2 subsets: distinct differences in homing and chemokine receptor
expression?
AB - The functional specialization of T effector cells according to cytokine secretion
patterns has been recognized as an important parameter shaping local immune
responses. Here we discuss evidence that T cell subsets might also develop
distinctive properties related to homing and trafficking into inflamed sites.
First, ligands for the inflammation-induced endothelial selectins were found to
be induced by IL-12, and hence selectively expressed on Th1 cells generated in
vitro. However, their expression on effector cells occurring in vivo is less well
correlated with the Th subset. Second, a variety of receptors for and responses
towards chemokines have been found to be differentially associated with Th
subsets. Notably CCR5 and, to a lesser degree CXCR3 were preferentially found on
Th1 cells, CCR4, CCR8 and, more controversial, CCR3 and CXCR4 on Th2 cells.
Although many points, such as stability of the phenotype versus dependency on
inducing cytokines and activation stages remain to be clarified, it appears that
this field provides new insights into the regulation of locally balanced
activities of Th subsets and might constitute a promising field for the
development of new immunosuppressive drugs.
PMID- 10666774
TI - Control of immune pathology by IL-10-secreting regulatory T cells.
PMID- 10666775
TI - Th1/Th2 balance in atopy.
PMID- 10666776
TI - Th1/Th2 balance in infection.
AB - Cytokines produced by T helper (Th) cells are of critical importance for the
outcome of many infectious diseases. Producing the "right" set of cytokines in
response to an infectious agent can be a matter of life or death. The Th1/Th2
dichotomy, although an oversimplification has proven useful in the analysis of
immune responses to infections. In some infectious diseases, most notably
leishmaniasis or infections with gastrointestinal helminths, one Th subset is
indispensable for clearing the infection, whereas the opposite Th subset is
detrimental. More frequently, both Th1 and Th2 responses are required at
different time points to effectively eradicate an infectious agent. The granuloma
responses to either Mycobacterium tuberculosis or Schistosoma mansoni provide
illustrative examples and are discussed in this review. There is accumulating
evidence for frequent coexpression of Th1 and Th2 cytokines during the in vivo
immune response to infections. The mechanisms by which infectious agents modulate
Th1/Th2 phenotype development are summarized here. Finally, we review here the
current evidence for cytokine imbalances induced by infections as pathogenic or
protective factors in autoimmunity and allergy.
PMID- 10666777
TI - Th1/Th2 balance in cancer, transplantation and pregnancy.
PMID- 10666778
TI - Type 1 and type 2 immune responses in children: their relevance in juvenile
arthritis.
PMID- 10666779
TI - Centenarians in the United States, 1990 and beyond.
AB - Persons who live to be 100 years-old and older constitute a fascinating cohort.
The number of these centenarians continues to grow fairly rapidly in the United
States, with less rapid growth evident in various other developed countries.
Characteristics of this cohort are studied with great interest in the hope of
discovering secrets of longevity and better understanding the aging process.
Using data from the 1990 Census of Population, this report examines the number of
centenarians enumerated in 1990 and reports projections for the future. In 1990,
37,306 persons were classified as centenarians but later evaluation determined
that this number was excessive. The Census Bureau now indicates the number
approximates 28,000 U.S centenarians for 1990. The 1990 data show that
centenarians were more likely to be women that men and to have lower educational
levels than those in younger cohorts. Most centenarians are widowed and around
one-half live in nursing homes. Looking to the future, the number of centenarians
is projected to increase dramatically and there will be greater racial and ethnic
diversity among those surviving to age 100 and above in the decades to come.
PMID- 10666780
TI - Cardiac catheterizations: average inpatient charges, 1998.
AB - In 1998 the average change for an impatient cardiac catheterization (CC)was
$12,450 among 13,922 group health insured over age 30. Among the 29 states in
which at least 150,CCs were performed, the average total charge ranged from
$24,000 in California, which was 93 percent above the U.S. norm, to just over one
third of this total in Iowa ($8,810). The second highest average charge was
reported in Texas ($20,140, 62 percent above the norm) and the second lowest was
in Maryland ($11,420, 8 percent below). On average, the hospital proportion of
the total CC charges accounted for 80 percent but ranged from 86 percent in
California to 71 percent in Maryland. Physician fees averaged $2,450 across the
country and ranged from $3,830 in Texas (56 percent above in average) to $2,140
in Iowa (13 percent below the norm). Length to stay averaged 3.2 days, with
patients in Iowa remaining in the hospital for 5.6 days and those in Washington
2.9 days. Per diem costs averaged $3,850 and were the highest in California,
$6,470 (68 percent above the average) and $1,570 in Iowa (59 percent below).
PMID- 10666781
TI - Confidence and confusion: the health care system in the United States.
AB - Results from the latest "Health Confidence Survey" show that Americans generally
appear to be happy with their health care system experiences. Satisfaction with
the care received over the past two years and with current health insurance plans
remains high and virtually unchanged since the 1998 survey. Close to nine out of
10 respondents were satisfied with their health plan in 1999 as well as the
quality of care received. Confidence in many aspects of the health care system is
high--94 percent of Americans report being confident that their pharmacist will
fill their prescription correctly, 90 percent are confident they will be able to
see a health care specialist, as needed, and 89 percent have confidence in the
quality of care that hospitals deliver. Confidence is not as high, however, for
belief in the confidentiality of medical records or that a fair review will be be
received if health insurance coverage is denied. While Americans are highly
confident in most aspects of the health care system today, they continue to be
less so for the next 10 years and even less so once they become Medicare
eligible. Confidence in the future of health care may be low because Americans
appear to be uncertain about managed care and what constitutes a managed care
plan. While 71 percent of those enrolled in a managed care plan label it as a PPO
or HMO, only 21 percent reported that they are currently enrolled ina managed
care plan. The fact that so many Americans do not know that their health plan is
a managed care plan lends support to our contention that these plans, benefits
managers, employers, policymakers and the media have failed to educate enrollees
and the general public about the features and potential advantages of such plans.
PMID- 10666782
TI - KIDS COUNT: identifying and helping America's most vulnerable.
AB - Using data from the 1999 KIDS COUNT Data Book, compiled and published by The
Annie E. Casey Foundation, the most recent state figures (1996) are compared with
corresponding data from 1985 to assess the trends in child well-being in each
state during the decade. The 10 key indicators used to rank states are taken fro
federal government statistical agencies and reflect the best data available for
each of the measures. Between 1985 and 1996, child well-being improved across the
country in seven of the indicators (infant mortality rate; child death rate; rate
of teen death by accidents, homicide and suicide; percent of teens who are high
school dropouts; percent of teens not attending school and not working; percent
of children living with parents who do not have full-time, year-round employment;
and percent of children living in poverty). The three areas of children's well
being that worsened during the time period were; the percent of low birth-weight
babies; teen birth rate; and percent of families with children headed by a single
parent. While many of America's children have experienced improvements in their
well-being, there is a large number of children who have been left behind. The
focus of the 1999 KIDS COUNT Date Book is on the 9.2 million children who have
been identified as "high risk." These children have four or more family
disadvantages that put them at greater risk of experiencing poor outcomes. These
kids are not benefiting from the continuing economic boom in the 1990s. The
District of Columbia, Louisiana and Mississippi had the largest share of high
risk kids, ranging from 39 to 21 percent of their respective populations, and
Utah the lowest, with just 5 percent. Long-term family-centered strategies that
are multi-dimensional and community-wide are recommended to help promote family
change.
PMID- 10666783
TI - Computer use among the U.S. school-aged population, 1989, 1993 and 1997.
PMID- 10666784
TI - [Serosurveillance of notifiable veterinary diseases in wild boar in the
Netherlands].
AB - During the hunting season 1996-1999, blood samples were collected from wild boar
shot in The Netherlands. Sera were screened for presence of antibodies against
classical swine fever virus (CSFV), swine vesicular disease virus (SVDV),
Aujeszky's disease virus (ADV), and Trichinella spiralis. The results indicate
that CSFV, SVDV, and ADV are uncommon in the wild boar population. Therefore, it
seems that CSFV, SVDV, and ADV infection in the wild boar population is not an
important reservoir in The Netherlands. ADV and CSFV infections are endemic in
the wild boar population in Germany. Since contact between the German and Dutch
wild boar populations can not be excluded, continuation of the sero-surveillance
system seems appropriate. In the decade before 1998, the wild boar population in
The Netherlands seemed to be free of T. spiralis. Whether the finding, in the
hunting season of 1998-1999, of a few wild boar with antibodies against T.
spiralis is an artefact or not, should be investigated in further research.
PMID- 10666785
TI - [Operative removal of a bladder stone by urethro-sphincterotomy in a pony mare].
AB - A case of a cystic calculus in a pony mare is described. In this case an urethro
sphincterostomy accomplished removal of a 362 g calculus with dimensions of 9 x 7
cm without any complications after surgery.
PMID- 10666786
TI - [Slappendel].
PMID- 10666787
TI - [Discussion of regular/alternative medicine from all times].
PMID- 10666788
TI - [Heck cattle in the Oostvaardersplassen: risk for infectious diseases or not?].
AB - This article discusses risk analysis of infectious diseases in a cattle
population. Heck cattle living in nature reserve 'De Oostvaardersplassen' were
studied as an example of the risk analysis approach. Twenty-five adult cattle
were tested for every infectious disease agent that the risk analysis indicated
might be prevalent. All sampled cattle tested positive for Bovine Herpesvirus 1,
whereas the prevalence of antibodies against other infectious disease agents was
below the level that was assumed to be the threshold for spread of the disease to
cattle in the surrounding areas. Risk management of infectious diseases was
expressed in a so-called 'low-risk profile'. The risk of introduction or spread
of infectious diseases was estimated to be very low as long as the population was
kept strictly enclosed.
PMID- 10666789
TI - [Refusing immunocastrated piglets].
PMID- 10666790
TI - [Transfusion medicine: from myth to reality].
PMID- 10666791
TI - [Transfusion medicine: debate, field of application, the stakes].
AB - Transfusion medicine has aroused much controversy as to the definition of its
field of application, as the Etablissement Francais du Sang (EFS) is being set
up. One argument put forward by supporters of transfusion medicine in hospital-
including nominal attribution and clinical immunohematology--is the possible
influence of blood component producers on the decisions of prescribers. The EFS
considers transfusion medicine as the rationale underlying a therapeutic chain
applied to blood products and possibly to cell therapy products, within a
coherent structure. Any disruption in the chain would result in reduced
visibility at each stage of the chain, diluted responsibilities, and less
efficient communication between blood collection and actual needs. It is,
however, extremely important to clearly distinguish between the activities
related to the production of biological products for therapeutic use from the
activities of evaluation, in the setting of clinical protocols, which are the
clinicians' responsibility. The EFS views the production of blood components as
one of the various aspects of its missions as a transfusion medicine operator.
The involvement of blood transfusion centers in the development of
biotechnologies is a historical reality which justifies EFS's ambition to
integrate cell therapy activities within its field of competence. The EFS, with
its 18 blood transfusion centers, will have to play a part in health care,
research and teaching networks, at the regional or inter-regional level.
Irrespective of the progress achieved in substitution products and the evolution
to be expected in transfusion-related jobs, transfusion as a discipline must
maintain its coherence to be able to better assume its responsibilities.
PMID- 10666792
TI - [Scientific bases of education in transfusion medicine].
AB - Transfusion medicine is a medical speciality which deals with all aspects of
blood transfusion. The recent evolution of this speciality was marked by an
increased collaboration with clinical medicine, the development of alternatives
to allotransfusion (autotransfusion, growth factors, molecular genetics), and the
technical progress in laboratory techniques. The development of basic science
boosted the introduction of new techniques in the detection of virus and blood
cell typing. The analysis of clinical trials allowed a better definition of
guidelines for the use of blood products. The blood transfusion teaching program
is limited during medical training. Specialists in transfusion medicine have to
complete a post-graduate course to become certified. Continuous medical training
is organised to allow the specialists to keep their accreditation. Transfusion
medicine is becoming more and more complex. This complexity should not lead to
breaking down transfusion medicine into several activities, but on the contrary
to uniting this medical speciality, within which the different actors shall
remain open-minded and able to use the same 'language'.
PMID- 10666793
TI - Vascular biosynthesis of nitric oxide: effect on hemostasis and fibrinolysis.
AB - Nitric oxide (NO) is a multifunctional effector molecule that plays a central
role in the regulation of vascular homeostasis. NO is synthesized from L-arginine
by a family of enzymes called NO synthases. The principal source of NO in the
vascular system of healthy mammals is the constitutively expressed NO synthase in
endothelial cells. The basal endothelial formation of NO can be increased by
receptor-dependent agonists (i.e., bradykinin) in a calcium-calmodulin-dependent
manner, and also by physical forces (i.e., shear stress), predominantly without
changes in the intracellular concentration of free calcium. Nitric oxide can
diffuse toward the blood vessel wall where the major target is the smooth muscle
cell. NO regulates vascular tone, and the free radical is also a potent inhibitor
of smooth muscle cell proliferation, migration and synthesis of extracellular
matrix proteins. NO can also diffuse toward the lumen of the blood vessel where
it helps maintain blood fluidity. NO inhibits platelets' and leucocytes' adhesion
to endothelial cells. In addition, NO inhibits platelet aggregation and
facilitates the dissolution of small platelet aggregates. However, the regulatory
action of NO on blood cells is most likely limited to the luminal surface of
endothelial cells since NO is rapidly scavenged by hemoglobin in erythrocytes and
inactivated by oxygen-derived radicals such as superoxide anions. NO can also
affect the fibrinolytic activity by regulating the release of tissue-type
plasminogen activator and plasminogen activator inhibitor-1. The crucial role of
vascular NO in the control of blood fluidity has been demonstrated by the
regulation of the bleeding time in humans.
PMID- 10666794
TI - [Developments in cell therapy in the year 2000].
AB - For the past thirty years, hematology has switched from the concept of bone
marrow transplantation to the concept of hematopoietic stem cell (HSC)
transplantation, from allograft to autograft, from non-manipulated graft to hyper
selection, from hematopoietic cellular therapy to immunotherapy. Indications of
these transplantations are now more clear for malignant diseases and are ongoing
for auto-immune diseases. A better knowledge of the HSC allows the control of
their proliferation and differentiation, opening the field of ex vivo expansion.
Very recently, new stem cells have been identified, establishing that a
differentiated cell retain its totipotency: a nervous system cell can
differentiate into HSC, which will further give hematopoiesis, mesenchymental
cells or hepatocytes. New tools are under development: human ES cells,
biomaterials, functionalized materials, opening the field of cellular engineering
in the year 2000.
PMID- 10666795
TI - [Preoperative strategy for homologous blood salvage and peri-operative
erythropoietin].
AB - The amount of transfused blood is related to blood loss calculated for the
specific type of surgical procedure, transfusion hematocrit trigger and patient's
red blood cell mass on the day before surgery. To optimise the benefit/cost and
benefit/risk ratios of blood transfusion, a correct prescription must be done in
accordance with the patient's red blood cell mass and surgical blood loss.
Indeed, there is a clear need to define the appropriate uses of blood management
methods and to seek new methods of improving perioperative blood management. The
number of moderately anaemic patients undergoing surgery is currently thought to
be 20%. Where transfusion requirements are estimated at two to three blood units,
as for instance in the most common types of orthopaedic surgery, preoperative
haemoglobin is the key factor governing transfusion needs. In this case, the
simplest approach is to prescribe Epoetin Alfa subcutaneous at a dose of 600
IU/kg/week starting three weeks before the surgery. In addition, it is important
in all cases to give concomitant iron supplements. Concomitant use of other
methods to decrease allogeneic blood requirements is of no value. Obviously, the
higher the haematocrit the day prior to surgery, the higher the patient's RBC
mass and the greater the patient's permitted blood loss, decreasing the
transfusion trigger. In this way, allogeneic blood loss is reduced, but without
the need for the patient to attend the blood transfusion center and to undergo
laboratory screening and testing of donated blood, and without the risk of
inducing preoperative anaemia compared with sequential autologous blood donation.
But, to optimise the benefit/cost ratio, we try to define precisely the patient
populations likely to benefit from preoperative erythropoietin. Using different
examples, management is proposed with algorithms.
PMID- 10666796
TI - [Sensitivity of screening kits for anti-HIV antibodies. 1999 update. Retrovirus
Working Group of the French Society for Blood Transfusion].
AB - A comparative evaluation of the sensitivity of anti-HIV screening assays has been
recently performed with a selected panel of 65 samples which included HIV1 group
M (per-seroconversions, seroconversions and seropositives infected with genotypes
A, B, C, D, E), HIV1 group O and HIV2. The results obtained with the 21 ELISA
HIV1 + HIV2 screening assays are presented. Among these 21 assays, four are
combined anti-HIV and p24 Ag assays. All the assays except four fulfilled the
criteria defined at the beginning of the study, i.e., positive results on all the
seropositives including seroconversions and positive results on at least 50% of
the per-seroconversions. The main differences were observed with the ten per
seroconversion samples, the number of positive results on such samples varying
from three to ten. The constant improvement of anti-HIV screening tests which
leads one to shorten the 'window' period permits and earlier diagnosis of HIV
infection and a progressive decrease of the transfusional risk.
PMID- 10666797
TI - [Erythrocyte adhesion to the vascular endothelium].
AB - Blood cells are in continuous contact with the vascular endothelium. Endothelial
cell culture, intravital videomicroscopy allowed the investigation of blood cell
endothelium interactions in dynamic conditions. In the various diseases, diabetes
mellitus, sickle cell anemia and malaria, erythrocytes have an increased adhesion
to endothelial cells. The presence of advanced glycation end products (AGE) on
erythrocytes of diabetics is responsible for their binding to the receptor RAGE
present on the endothelium. The AGE-RAGE binding provokes an oxidant stress and
induces the expression of the adhesion molecule. Furthermore, erythrocyte AGE
induce an increase in vascular permeability. In sickle cell anemia, the increased
adhesiveness and the sickling of red blood cells are responsible for thrombosis.
Plasmodium falciparum infestation of erythrocytes induces knob formation at the
cell surface and the P. falciparum protein binding to CD36, ICAM-1 and
thrombospondin present on the endothelium, and facilitates the parasite
dissemination.
PMID- 10666798
TI - [Quality control of labile blood products. Why and howto properly take a
specimen? Labile Blood Products Group of the French Blood Transfusion Society].
AB - This article reviews the various techniques of sampling used for the quality
control of blood cell products. The importance of this stage for the validity of
quality control results is emphasized. Three sampling methods, i.e., stripping,
the sterile connection of sampling bag and the destructive method, are described
in the form of operating modes and analyzed according to their advantages and
drawbacks. The results of a comparative study carried out by the working group
'Blood Cell Products' of the French Society of Blood Transfusion are presented,
showing that each method is valid and permits one to obtain a representative
sample of the product to be controlled. Thus the diversity of the sampling
methods allows us to select the one most adapted to the product to be controlled
and to the analyses to be carried out afterward.
PMID- 10666799
TI - [Preparation of cell therapy products: contribution of closed systems].
AB - A phase I clinical trial is being currently performed in our institution, aiming
at evaluating the feasibility and toxicity related to the administration of
Herpes Simplex-thymidine kinase gene-expressing human primary T lymphocytes
following allogeneic hematopoietic stem cell transplantation. The need for safe
and standardized preparation conditions for gene-modified cells is crucial. We
describe the closed culture system used in the current trial for ex vivo
retroviral-mediated gene transfer and transduced cell selection. Cell handling is
performed in closed systems using sampling and transfer pack bags, culture bags
and a sterile connection device which avoids opening the culture system. This
closed system allows safe and reproducible ex vivo preparation of gene-modified
primary T-lymphocytes for clinical use.
PMID- 10666800
TI - Management of Lyme borreliosis and emerging tick-borne diseases in Europe.
PMID- 10666801
TI - Principles of the diagnosis and antibiotic treatment of Lyme borreliosis.
AB - Clinical signs and symptoms are an essential aspect of the diagnosis of Lyme
borreliosis. Thus, a thorough knowledge of the clinical features of the disease
is important. Established clinical definitions could be of help in everyday
clinical practice and especially to compare the findings of different authors or
groups. The characteristic sign that permits the diagnosis of Lyme borreliosis is
a typical erythema migrans skin lesion. Highly suggestive manifestations are ear
lobe lymphocytoma, acrodermatitis chronica atrophicans and Bannwarth's syndrome.
The majority of other signs and symptoms are only suggestive and, when expressed
individually, may have a very limited or even symbolic value for the purpose of
diagnosis. Laboratory confirmation of borrelial infection is needed, as a rule,
for all manifestations of Lyme borreliosis with the exception of typical erythema
migrans. In clinical practice indirect laboratory methods are usually employed.
Determination of borrelial IgM and IgG antibodies by immunofluorescence assays or
enzyme-linked immunosorbent assays has not been standardised, and correlation of
the results from different laboratories and/or different commercial tests may be
poor. Immunoblotting may solve some of the many dilemmas but could (especially in
Europe) raise additional questions in a field in which numerous uncertainties
already exist. The reliability of methods for direct detection of borrelial
infection other than culture to ascertain spirochetes in tissue specimens is open
to question. Treatment with antibiotics is reasonable in all stages of Lyme
borreliosis and for all clinical manifestations; however, it has been most
effective early in the course of the illness. The choice of antibiotic depends
upon many factors including the efficacy, pharmacokinetic profile, side effects,
expected compliance and price. For the majority of manifestations the most
effective antibiotic, the optimal dosage, and the most appropriate duration of
treatment have not been exactly determined. Recommendations for the treatment of
Lyme borreliosis in Slovenia are presented.
PMID- 10666802
TI - Comparison of cefuroxime axetil and phenoxymethyl penicillin for the treatment of
children with solitary erythema migrans.
AB - OBJECTIVE: To compare the clinical efficacy and drug-related adverse effects of
14 days of treatment with cefuroxime axetil 30 mg/kg/day or phenoxymethyl
penicillin 100,000 IU/kg/day in the treatment of children with erythema migrans.
METHODS: Consecutive patients younger than 15 years, referred to our institution
in 1996 with solitary erythema migrans and without prior antibiotic therapy, were
included in this prospective study. Basic demographic features and clinical data
were collected by questionnaire. The efficacy of the treatment of acute disease,
development of major and/or minor manifestations of Lyme borreliosis and drug
related adverse effects were surveyed at follow-up visits during the first year
after the initiation of antibiotic treatment. RESULTS: Forty-six patients
received cefuroxime axetil (group C) and 44, phenoxymethyl penicillin (group P).
The two groups differed in terms of age (patients in group C were younger), but
no other differences in demographic and clinical pre-treatment characteristics
were present. The clinical course during the post-treatment period revealed no
significant differences between the two groups: the duration of erythema migrans
(7.1 +/- 7.5 days in group C, 10.6 +/- 19.3 days in group P) and the appearance
of minor manifestations of Lyme borreliosis (8.8% in group C, 9.1% in group P)
were comparable; no major manifestations were recorded. Twelve months after
antibiotic treatment all patients were free of symptoms. The patients treated
with cefuroxime axetil had more drug-related adverse effects than did those
treated with phenoxymethyl penicillin (26.1% versus 6.8%, p = 0.0301).
"Herxheimer's reaction" at the beginning of treatment was identified more often
in group C than in group P, but the difference was not statistically significant.
CONCLUSIONS: Cefuroxime axetil and phenoxymethyl penicillin are equally effective
in the treatment of children with solitary erythema migrans; however drug-related
adverse effects were more frequently observed with cefuroxime axetil.
PMID- 10666803
TI - Erythema migrans in the immunocompromised host.
AB - From 1990 to 1996 a total of 67 adult patients with typical erythema migrans (EM)
and a previously identified immunocompromised condition were investigated at the
University Medical Centre, Department of Infectious Diseases, Ljubljana,
Slovenia. The course and outcome of borrelial infection were compared with 67
previously healthy age and sex-matched individuals with EM who were examined at
our institution in the same year. Clinical characteristics of Lyme borreliosis
before treatment and the duration of EM after the institution of therapy with
antibiotics including amoxicillin, azithromycin, cefuroxime-axetil, doxycycline,
and ceftriaxone were comparable in both groups. The occurrence of early
disseminated borrelial infection before treatment and the frequency of treatment
failure (defined as the onset of severe minor or major manifestations of Lyme
borreliosis, persistence of B. burgdorferi sensu lato in the skin and/or
persistence of EM after treatment) were found significantly more often in
immunocompromised patients than in the control group (16/67 versus 6/67,
respectively; p = 0.0358). Re-treatment was required in 13 (19.4%) patients of
the immunocompromised group and only in five (7.5%) patients of the control group
(p = 0.0762). However, in spite of the more severe course and the more frequent
need for re-treatment among patients whose immune system was impaired, the
outcome of borrelial infection after one year was favourable in both groups.
PMID- 10666804
TI - Erythema migrans in pregnancy.
AB - From 1990 through to 1997, 105 pregnant women with typical EM were investigated
at the Lyme Borreliosis Outpatients' Clinic of the Department of Infectious
Diseases at the University Medical Centre in Ljubljana, Slovenia. Twenty-five
(23.8%) patients acquired borrelial infection during the first trimester of
pregnancy; eight (7.6%) of them had noticed the skin lesion before they became
pregnant. In 43 (40.6%) patients the EM appeared in the second trimester, and in
37 (35%) patients in the third trimester of pregnancy. Two (1.9%) patients
received phenoxymethyl penicillin (1 million IU t.i.d.), three (2.9%) benzyl
penicillin (10 million IU b.i.d.), and 100 (95.2%) ceftriaxone (2 g daily). All
patients were treated for 14 days except three (2.9%) in whom the treatment with
ceftriaxone was discontinued because of mild side effects. The outcome of disease
was good in all 105 patients. Ninety-three (88.6%) out of 105 patients had normal
pregnancies; the infants were delivered at term, were clinically healthy, and
subsequently had a normal psychomotor development. In the remaining 12 (11.4%)
patients an adverse outcome was observed. Two (1.9%) pregnancies ended with an
abortion (one missed abortion at 9 weeks, one spontaneous abortion at 10 weeks),
and six (5.7%) with preterm birth. One of the preterm babies had cardiac
abnormalities and two died shortly after birth. Four (3.8%) babies born at term
were found to have congenital anomalies; one had syndactyly at birth and three
had urologic abnormalities which were registered at the age of 5, 7, and 10
months, respectively. A causal association with borrelial infection was not
proven in any infant. For at least some unfavourable outcomes a plausible
explanation not associated with Lyme borreliosis was found.
PMID- 10666805
TI - The outcome of Lyme borreliosis in children.
AB - Austria is an endemic area for Lyme borreliosis. The IgG seroprevalence of
healthy blood donors as investigated by a DAKO flagellum-ELISA in Graz/Styria is
13%. In order to determine whether this high seroprevalence is caused by
infection in childhood, 36 children aged 3 to 18 years (mean, 10.1 years) were
followed up over 2 to 20 months (mean, 11.1 months) and reinvestigated for
clinical symptoms and antibodies against B. burgdorferi by a commercial flagellum
ELISA and a commercial B. garinii Western blot (WB). Twenty-seven children had
erythema migrans (EM), one of them with reinfection, 5 had borrelia lymphocytoma
(BL), 2 EM and BL, 1 acrodermatitis chronica atrophicans and 1 ACA/circumscribed
scleroderma. Before treatment with either phenoxymethylpenicillin, amoxicillin,
or minocyclin for 3-4 weeks, 64% of the patients were IgM and 44%, IgG
seropositive. Clinically, all but 5 patients with EM recovered from Lyme
borreliosis. Among these 5 patients--one of them with reinfection of EM--3 had
mild arthralgia, 1 recurrent headache and 1 concentration disturbance. Only 2
children with arthralgia were IgM positive by ELISA and WB. One of 5 BL patients
had a persistent swelling of the ear lobe although with a negative serology
before and after several antibiotic treatments and at follow up. In 16 children
serological investigations were performed after more than 12 months (range, 13-20
months). Eighteen percent of them had IgM antibodies by ELISA, 25% by WB, and 6%
IgG antibodies by ELISA and 6% by WB. Although there was a decline of antibody
response from 64% to 18% for IgM and from 44% to 6% for IgG as measured by ELISA,
children remain seropositive for more than 1 year with or without clinical
symptoms. The relevance of the association with clinical symptoms can be raised
by combining several diagnostic methods. It is assumed that recurrent, often
silent, infections might increase antibody titres. It should be noted that
antibody titres also generally increase with the age of individuals.
PMID- 10666806
TI - Has the presence or absence of Borrelia burgdorferi sensu lato as detected by
skin culture any influence on the course of erythema migrans?
AB - The aim of this prospective study was to compare epidemiological and clinical
data in patients with a positive Borrelia burgdorferi sensu lato culture and
culture-negative erythema migrans skin lesions. Of the 546 adult patients with
erythema migrans seen at our institution in 1997 in whom a skin biopsy was
performed and the specimen cultured for the presence of B. burgdorferi sensu
lato, 235 (43%) had a positive and 311 (57%) a negative skin culture. More women
than men were present in both groups and women were also significantly older than
men. Tick bites resulting in culture-positive erythema migrans predominated in
May (p = 0.012), while in August and September tick bites with subsequent culture
negative skin lesions were more common (p = 0.018 and 0.011, respectively).
Similarly, erythema migrans lesions noticed by our patients in May were
significantly more often Borrelia culture positive than negative (p = 0.004),
while lesions appearing in October were significantly more often culture negative
(p = 0.004). In addition to these seasonal differences, the comparison of the
large number of Borrelia skin culture-positive and -negative patients with
erythema migrans also revealed differences in several clinical parameters
including a larger diameter of skin lesions in the culture-positive group (p =
0.007 at presentation, and p = 0.039 at registration, respectively), a lesser
number of multiple skin lesions (7/235 versus 27/311, p = 0.006), and a lower
frequency of signs/symptoms (p = 0.039) associated with erythema migrans lesions
in culture-positive than in culture-negative patients. We have no plausible
explanation for the majority of these rather unexpected findings. Of the 59
patients who, prior to biopsy, had received brief courses of antibiotics known to
be effective in the treatment of erythema migrans, 12 (20.3%) were culture
positive. As anticipated, the ratio of culture positivity in pretreated patients
was significantly lower (p < 0.001) than in those without antecedent antibiotic
therapy.
PMID- 10666807
TI - Erythema migrans and serodiagnosis by enzyme immunoassay and immunoblot with
three borrelia species.
AB - There is wide divergence of opinion between physicians regarding the use of
serological measures for the diagnosis and treatment of erythema migrans, the
hallmark of Lyme borreliosis. We studied the outcome of an enzyme immunoassay and
immunoblot (Western blot) used on the sera of patients who had suffered tick bite
and erythema migrans, and had been subsequently treated with various antibiotics.
Ninety-nine consecutive patients presenting with erythema migrans after tick bite
were prospectively recruited at the outpatient department of two Vienna City
hospitals and at the consultation office for Lyme borreliosis of the Institute of
Hygiene. University Vienna. Blood samples were taken before antibiotic treatment
and 3 and 6 months thereafter. Blood samples from 100 blood donors served as
controls. Antibodies against Borrelia burgdorferi sensu lato were determined by
enzyme immunoassay (IgG and IgM EIA) and by IgG immunoblot. The latter was
performed with isolates of B. alzelii (H2) B. burgdorferi sensu stricto (Le) and
B. garinii (W) from Austrian patients. The 4 interpretation criteria for
immunoblot results were: A (3 bands out of 8), B (2 bands out of 9), C and D (1
band out of 6). In all patients, the erythema resolved within the treatment
period. No complications secondary to the borrelia infection were registered.
After treatment there was no significant change in titre, nor was there a
difference in the immunoblot pattern between the first, second and third serum
samples. Serum antibodies to B. burgdorferi were positive by EIA in 22.9% (IgG)
and 2.5% (IgM). Immunoblot results offered by borrelia species and by the
interpretation criteria, ranging between 8.3% (criterion A, strain Le) and 44.2%
(criterion D, strain H2). By EIA, control samples were IgG and IgM positive in 5%
and 1%, respectively. Positive immunoblot results with strain H2 were found in
9%, 13%, 18%, and 20% by the criteria A through D respectively. After antibiotic
treatment of erythema migrans the immunological response appears to be abrogated.
Thus, serological results are not supportive for the diagnosis of erythema
migrans, not will they retrospectively prove successful antibiotic treatment of
borrelia infection.
PMID- 10666808
TI - Is IgM of diagnostic value in case of delayed intrathecal production of IgG
antibodies?
AB - The neurological manifestations of Lyme borreliosis comprise a wide range of
clinical signs. However, these symptoms might have other aetiologies. Therefore
detection of intrathecal production of specific antibodies is necessary to
confirm the clinical assumption of neuroborreliosis (NB). In case of delayed
intrathecal production of specific IgG antibodies, detection of IgM could play a
role in the early diagnosis of NB. To clarify whether IgM is of diagnostic value
in such cases, paired CSF serum samples from 176 patients with suspected NB
admitted to the department of Neurology, Karl Franzens University, Graz, Austria,
were tested. Testing was performed with the IDEA Neuroborreliosis Kit (Dako,
Denmark) and Enzygnost Borreliosis (Behring, Germany) and results of both methods
were compared. According to well defined criteria 63 of the 176 patients had
defined NB and 113 were regarded as possible NB. Twelve out of 63 patients with
defined NB had delayed intrathecal IgG production. Only one patient with delayed
IgG production had an intrathecal IgM production prior to IgG. In all patients
with possible NB no intrathecal production of IgM was detected. At the time of
the first lumbar puncture IgG intrathecal production could be detected with the
IDEA seven times more often than with the Enzygnost Borreliosis. The
determination of intrathecal production of IgM does not appear to be of
diagnostic value in patients with delayed IgG antibody production. Therefore a
consecutive lumbar puncture is more likely to confirm clinical assumption if
there is strong clinical evidence of NB.
PMID- 10666809
TI - Lyme meningitis: a one-year follow up controlled study.
AB - Thirty-six patients with Lyme meningitis diagnosed at the Department of
Infectious Diseases, University Medical Centre, Ljubljana in 1993 and 1994 were
enrolled in a prospective study. All patients had lymphocytic meningitis,
negative serum IgM antibody titres to tick-borne encephalitis virus and met at
least one of the following four criteria: i) isolation of Borrelia burgdorferi
sensu lato from cerebrospinal fluid (2 patients), ii) intrathecal borrelial
antibody production (22 patients) iii) seroconversion to borrelial antigens (3
patients) and/or iv) erythema migrans in the period of four months prior to the
onset of neurological involvement (21 patients). All patients underwent
antibiotic treatment and were followed up for one year. The results of our study
revealed that Lyme meningitis frequently occurs without meningeal signs and is
often accompanied by additional neurological and/or other manifestations of Lyme
borreliosis. During the first year after antibiotic treatment, minor and major
manifestations of Lyme borreliosis persisted or occurred for the first time in
several patients. They were not infrequent even at the examination performed one
year after therapy.
PMID- 10666810
TI - Borrelia burgdorferi as a cause of Morgagni-Adams-Stokes syndrome. Long time
follow-up study.
AB - According the literature atrio-ventricular blockade (AVB) is the most frequent
and well-known symptom of Lyme carditis. Typical signs of complete AVB include
fatigue, lethargy and syncope- Morgagni-Adams-Stokes syndrome (MAS). The authors
present their results and experience with 5 patients selected from a long-term
study (conducted between 1987 and 1998) comprising 58 patients who developed MAS.
The authors tried to evaluate the changes especially in the cardiovascular
system. They correlated the clinical state with ECG findings, as well as with the
levels of the Borrelia burgdorferi antibodies. The following results were
obtained: 1) all patients had typical syncope, 2) the clinical course was not
complicated (except one patient who developed ventricular fibrillation), 3) two
patients had frequent symptomatic and asymptomatic arrhythmia including chest
pain and episodic rest dyspnea, 4) subjective difficulties (usually palpitations)
correlated with ECG findings (Lown 3a, 3b). The authors also looked for any
relationship between clinical difficulties and levels of antibodies. The results
obtained with an early permanent pacemaker were less favourable than those
reported in the literature. Despite early treatment 2 patients had repeated
palpitations and ECG correlates during the next years.
PMID- 10666811
TI - Lyme borreliosis and peripheral facial palsy.
AB - From 1994 to 1996, 114 consecutive patients older than 15 years who presented at
the Department of Infectious Diseases, University Medical Centre, Ljubljana,
fulfilled the criteria for inclusion into this study on the borrelial aetiology
of peripheral facial palsy (PFP). The study was restricted to patients without a
conceivable explanation for their PFP, erythema migrans or history of erythema
migrans, clinical signs/symptoms of frank meningitis or any other neurological
manifestation in addition to PFP. In 22 (19.3%) of these 114 patients borrelial
infection was confirmed by one of the following: in 3 (13.6%) by the isolation of
Borrelia burgdorferi sensu lato from cerebrospinal fluid (CSF), in 11 (50%) by
the presence of intrathecal antibody production, and in 8 (36.4%) by
seroconversion to borrelial antigens. Additional 20 (17.5%) patients interpreted
as having had a probable borrelial infection, had positive (> or = 1:256) IFA IgM
and/or IgG borrelial serum antibody titres, and in 9 (7.9%) patients borderline
borrelial antibody titres (1:128) were found (interpreted as a possible
infection). In 63 (55.3%) patients the serological tests remained negative.
Lymphocytic pleocytosis was found at the first visit in 12/22 (54.5%) patients
with confirmed borrelial infection, in 3/20 (15%) with probable infection, in 1/9
(11.1%) with possible infection, and in 10/63 (15.9%) patients with symptoms of
unknown aetiology. Patients with confirmed borrelial infection had abnormal CSF
findings significantly more often than did patients with symptoms of unknown
aetiology (p = 0.0139 for lymphocytic pleocytosis and/or elevated CSF protein
levels, and p = 0.0010 for lymphocytic pleocytosis). Local and systemic signs/
symptoms were also more common in patients with confirmed borrelial infection
than in those with an symptoms of unknown aetiology (p = 0.0258). In Slovenia
which is a highly endemic region for Lyme borreliosis, borrelial infection is a
frequent cause of PFP in adult patients. PFP may occur early in the course of LB,
prior to measurable antibody response, indicating the need for serologic follow
up. Abnormal CSF results and the presence of additional local and/or systemic
symptoms are factors indicating a higher possibility of borrelial aetiology of
PFP and should alert physicians to suspect LB.
PMID- 10666812
TI - Diffuse reversible alopecia in patients with Lyme meningitis and tick-borne
encephalitis.
AB - Alopecia occurring after febrile bacterial and viral infection is a phenomenon
well known since the beginning of the century. To evaluate the occurrence of
alopecia in tick transmitted disease, 23 adult patients with Lyme meningitis and
71 patients with tick-borne encephalitis were included in a prospective study and
were followed up for one year. Diffuse alopecia occurred within three months
after the outbreak of disease in 3 out of 23 (13%) patients with Lyme meningitis
and in 40 out of 71 (56.3%) patients with tick-borne encephalitis. The mean
duration of alopecia was 2 to 3 months and alopecia was reversible in all
patients.
PMID- 10666813
TI - The course of Lyme disease in different age groups.
AB - Lyme disease is a multisystem infection affecting all age groups. In this study
an attempt was made to determine whether the patient's age influences the course
of the disease. One hundred and fifty patients with diagnosed Lyme disease were
included in the study. Two serological methods were used to detect antibodies to
Borrelia burgdorferi and to confirm the diagnosis: an indirect immunofluorescence
assay (the Russian strain Ip-21) and Western blot. The course of Lyme disease did
not differ from that seen in Europe and North America. However, a few clinical
differences between groups were observed. In the first age group (0-15 years) the
most common manifestation was flu-like symptoms with fever. Neither
radiculoneuritis nor polyneuropathy was observed in this age group. Late
manifestations were rare and the outcome of the disease was benign. The course of
the disease in the second group (16-40 years) was most similar to that in
childhood and the also outcome was similar. Carditis and erythema multiple were
significantly more common in the second group (16-40 years) than in the other age
groups. No differences were found between the third (41-60 years) and fourth (>
than 60 years) group in the frequency of flu-like symptoms, erythema multiple and
aseptic meningitis. However, the most important clinical sign in this group was
involvement of the nervous system whereas in the third group this was joint
damage. This feature deserves attention because, as a rule, the presence of an
articular syndrome determines the prognosis of LD.
PMID- 10666814
TI - Studies on the pathogenesis and treatment of Lyme arthritis.
AB - Lyme arthritis is one of the most common clinical manifestations of Lyme
borreliosis. It is caused by an intraarticular infection with Borrelia (B.)
burgdorferi. A small number of bacteria are liable to provoke severe arthritis by
inducing mechanisms (including the induction of cytokines and chemokines) that
amplify the inflammatory response. The cellular immune response against B.
burgdorferi is characterised by a predominant T helper cell type 1 (Th1) pattern
that appears to be inadequate to overcome the infection. In most cases, Lyme
arthritis may be cured by antibiotic therapy. A brief summary of current
recommendations for the treatment of Lyme arthritis in adults and children is
given in this article. However, about 10% of Lyme arthritis patients do not
respond sufficiently to antibiotic treatment. Two not mutually exclusive
pathogenetic concepts of these treatment-resistant cases will be discussed in the
present study: persistent infection and infection-induced immunopathology.
PMID- 10666815
TI - Functional heterogeneity in the antibodies produced to Borrelia burgdorferi.
AB - Antibodies to outer surface molecules of Borrelia burgdorferi (Osp) that have a
bactericidal action in the absence of complement have been described. These
antibodies are primarily monoclonal to antigenic determinants in OspA and OspB.
One of these, CB2, is an IgG1 monoclonal antibody that recognizes an epitope in
the carboxy terminus of OspB. The specificity of CB2 is critically dependent on
the presence of a lysine (Lys) residue in position 253, not only for binding but
also for killing the spirochete. This antibody has been used successfully to
select escape variants or mutants that are missing the Lys residue either by a
mutation or by deletion as a result of premature stop codons. Other antibodies to
OspA, OspB, and p39 have also been characterized with similar properties. Another
important feature of CB2 is that its bactericidal action is not dependent on
agglutination, since Fab fragments of the whole immunoglobulin molecule can also
kill in the absence of complement synergy. The killing action of CB2 is not
inhibited by protease inhibitors, and is dependent on the presence of calcium.
Upon contact with Borrelia burgdorferi, CB2 causes lysis of the outer membrane
and the formation of a spheroplast. The bactericidal mechanism of this antibody
is not known. The sequence of the heavy and light chain variable regions of CB2
have striking homology to murine antibodies of the autoimmune repertoire, and
some of these antibodies have catalytic properties. In general, catalytic
antibodies have enzymatic rates of acceleration that are significantly less than
those of proteolytic enzymes. If CB2 were a catalytic antibody, its substrate
specificity may be expected to be broader. CB2 does not cleave recombinant OspB,
nor does it cleave other protein substrates. Its killing activity is not
dependent on proteolysis. Because the bactericidal action of CB2 involves the
destruction of the outer membrane, it is possible that a phospholipase could be
associated with the mechanism. The mobility of spirochetal lipids is altered
after incubation with CB2, and the bactericidal activity is reduced in the
presence of phospholipase inhibitors. These studies suggest that the bactericidal
mechanism of CB2, and other similar antibodies, is novel.
PMID- 10666816
TI - Risk assessment in Lyme borreliosis.
AB - A 3-year EU-funded project (EUCALB), initially involving 14 countries and more
than 30 scientists and physicians, was undertaken with the main objective of
identifying practical risk assessment criteria for Lyme borreliosis. A major part
of the project was dedicated to the improvement of data quality. European case
definitions were formulated and quality assurance schemes were developed for
serological diagnosis and the detection of infection in ticks. Studies on the
standardisation of immunoblot interpretation criteria are still in progress. Data
on the clinical risk from tick bites were obtained and considerable progress was
made in elucidating the complex ecology of the disease. A study on habitat
assessment throughout Europe concluded that high risk was associated with highly
heterogeneous recreational woodland and case data from both high and low
incidence countries suggested that most infections were acquired in recreational
areas. Considerable work is still required to relate clinical data to the
epidemiology and ecology of the disease in order to assess risk in Lyme
borreliosis.
PMID- 10666817
TI - Species identification of Borrelia burgdorferi sensu lato from tick and human
isolates in Styria (Austria) by PCR-RFLP analysis.
AB - Seventy-one isolates of Borrelia burgdorferi sensu lato (B.b.s.l.) derived from
Ixodes ricinus ticks (50 strains) and patients (21 strains) were characterised by
PCR-RLFP analysis. In four cases the human isolates were obtained from the
cerebrospinal fluid (CSF) of patients with clinical symptoms of neuroborreliosis
and in 17 cases from skin biopsies of patients with dermatological manifestation
of Lyme borreliosis. Ixodes ricinus isolates originated from 14 localities in
three regions (Mur valley, eastern and western Styria) in Styria. Thirty six
strains of B.b.s.l. were isolated from nymphal ticks, nine strains from female
and five strains from male ticks. Species identification of human isolates
revealed three B. garinii and one B. afzelii isolates in CSF. In the PCR-RFLP
analysis of 17 skin specimens a pattern for B. afzelii was found in ten cases,
while six could be identified as B. garinii and one as a mixed infection of B.
afzelii and B. garinii. Genetic characterisation of tick isolates resulted in 24
strains of B. afzelii (48%), 11 strains of B. garinii (40%) and 5 strains of B.
burgdorferi s.st. (10%); one isolate showed a mixed infection of B. afzelii and
B. garinii. Our findings indicate that B. afzelii and B. garinii predominate over
B. burgdorferi s.str. in Ixodes ricinus ticks from Styria, which is similar to
findings in neighbouring countries. This also reflects the occurrence of
different pathogenic Borrelia strains in human samples.
PMID- 10666818
TI - Infection of small mammals with Borrelia burgdorferi sensu lato in Slovenia as
determined by polymerase chain reaction (PCR).
AB - Thirty-four small mammals collected in the vicinity of Ljubljana were tested for
the presence of Borrelia burgdorferi sensu lato by polymerase chain reaction
(PCR) of urinary bladder tissues, using universal flagellin primers and species
specific rRNA primers. Seventeen small mammals (50%) were found to be positive,
and 7 small mammals were infected with two species of B. burgdorferi sensu lato
simultaneously. The most commonly found species was B. afzelii (n = 14), followed
by B. burgdorferi sensu stricto (n = 7) and B. garinii (n = 3), as determined by
species-specific primers. We conclude that PCR is a rapid and reliable method to
detect infection with B. burgdorferi sensu lato in small mammals.
PMID- 10666819
TI - Epidemiological aspects of human granulocytic Ehrlichiosis in southern Germany.
AB - Human granulocytic Ehrlichiosis (HGE) is a newly emerging acute febrile illness
which is likely transmitted by ticks of the Ixodes ricinus/I. persulcatus
complex. First seroepidemiological surveys on the prevalence of HGE antibodies,
detection of DNA of granulocytotropic Ehrlichiae in I. ricinus and one case of
HGE from Slovenia confirmed by serology and PCR (polymerase chain reaction)
suggest that HGE might exist all over Europe. The purpose of the present study
was a) to determine the prevalence of antibodies against the HGE agent in sera
collected from persons at high risk for exposure to I. ricinus with that of a
control population and b) to determine the prevalence of granulocytic Ehrlichiae
in I. ricinus ticks from Southern Germany. We studied sera from 150 forestry
workers and 105 patients with an established diagnosis of Lyme disease as tick
exposed populations. Sera from 103 healthy blood donors without a history of
known tick bites served as controls. A significantly higher prevalence of HGE
antibodies (P < or = 0.01) was present among patients with Lyme borreliosis (12
of 105 were positive; 11.4%) and forestry workers (21 of 150 were positive; 14%)
compared to blood donors (2 of 103 were positive; 1.9%). Furthermore, 510 adult
and nymphal I. ricinus were investigated by PCR for the presence of granulocytic
Ehrlichiae with primers specific for the E. phagocytophila group. In eight (1.6%)
of the investigated ticks the expected amplification product was detectable,
indicating a low prevalence of infected ticks especially when compared with B.
burgdorferi. The presented data strongly suggests that the HGE agent or a closely
related organism exists in Southern Germany and therefore HGE should be
considered in the differential diagnosis of febrile illnesses. However, final
evidence can be provided only after isolation of the organism from patients.
PMID- 10666820
TI - [Reducing pain by oral enzyme therapy in rheumatic diseases].
AB - Proteolytic enzymes have analgesic, effects, besides the wellknown
antiinflammatory and edema-reducing properties. These analgesic effects are based
on the inhibition of inflammation and in addition to that on direct influences on
the nociceptors. All that explains the therapeutical effects of such enzymes in
degenerative-rheumatic and soft tissue rheumatic diseases in which inflammatory
or immunologic processes are not in the forefront. In recent years a significant
reduction of pain in various rheumatic diseases, concerning these aspects, was
shown in several clinical studies. The clinical trial in patients with
periarthritis of shoulder showed statistical equivalence of pain reduction,
whether they were treated with phlogenzym or diclofenac. Likewise in the trial of
patients suffering from painful osteoarthritis of the knee, there was a
statistical equivalence of the pain-scores, comparing diclofenac and enzymes. The
study of painful vertebral syndromes again resulted in equivalence of the
treatment with NSAIDs compared to therapy with enzymes.
PMID- 10666821
TI - [Compression treatment after burns].
AB - After healing up of the injury wounds, hypertrophic scars and keloids often
develop, which are histologically characterised by irregulary arranged collagen
fibre bundles and a strong vascularisation. Approximately 20 years ago, the so
called compression clothing, as for example suits, masks, gloves, stockings, were
first employed for the prevention and therapy of these complications. These means
of compressions are crosswise and lengthwise elastical and consist predominantly
of elasthan and viscose. The pressure acting on the skin lies between 25 and 32
mmHg: thereby the values are above the average capillary pressure of 20 mmHg. The
efficiency of the compression clothing after a burn injury is well proved by
several studies, and one knows today that, for example in the case of children as
from the 5th year of life, the results are better than in the case of adults from
the 35th year of life. The compression effected at least during a period of 15
months slows down the blood circulation, reduces the number of capillaries and
makes the scar become more pale. Furthermore, the orthologically parallel
arranged collagen fibres maintain their arrangement due to the compression
pressure and do not get irregularily arranged.
PMID- 10666822
TI - [Alzheimer disease--differential diagnosis and modern therapy].
AB - Alzheimer's disease and other dementias are a multidisciplinary challenge and
become more and more important because of the growing life expectancy, and also
due to the presence in the media. A. Alzheimer published first 100 years ago the
disease named after him as an entity marked by the clinical course and by typical
histological findings. The last decades brought remarkable progress in
demarcation to other forms of dementias for example by CT or MRI. The cause of
Alzheimer's disease has not yet been cleared up. The finding of secondary
dementias has great importance since causal therapeutic possibilities exist. In
the last years new ideas to etiology in respect to the hypothesis of
acetylcholine resulted in new therapeutic promises. A rational treatment of this
disease seems now possible. Besides psychological and behavioral signs and
symptoms of dementia are of great importance in the care of these patients.
PMID- 10666823
TI - [Therapy of heart failure with ACE inhibitors--"evidence-based medicine" and
clinical reality].
AB - Treatment of patients with chronic heart failure improves symptoms and NYHA
functional class in about 50-80% of all patients treated. A 15% reduction can be
observed in the need for hospitalisation and a 16-31% reduction in 1-year
mortality. 37% risk reduction for progression to symptomatic heart failure can be
achieved with ACE-inhibition in asymptomatic patients with systolic left
ventricular dysfunction (55). Thus, ACE-inhibition should be part of standard
treatment in symptomatic and asymptomatic patients with left ventricular
dysfunction. In symptomatic patients with chronic heart failure, combination
therapy of an ACE-inhibitor with digitalis and diuretics is state of the art and
improves symptoms significantly. The addition of a vasodilatator can be
considered in selected cases. Based on recently published data on beta
adrenoreceptor-blockade in the treatment of chronic heart failure, beta-blockers
seem to get part of standard therapy of heart failure in the present and near
future (2, 44, 50, 60). In spite of innovations of modern heart failure therapy
prognosis is still bad. Survival after diagnosis of severe heart failure
(functional class NYHA III and IV) is limited to a mean of 14 month.
PMID- 10666824
TI - [Peripheral arterial occlusive disease].
PMID- 10666825
TI - [Methods and results of controlled walking training in patients with peripheral
arterial occlusive disease].
AB - To establish the effect of exercise training in patients with PAOD Stage II
according to Fontaine, 125 publications between 1966 and 1998 were systematically
reviewed. The best results occurred with the following method: duration greater
than 30 minutes per session, frequency of at least three sessions per week,
intermittent walking to near-maximal pain and program length of greater than six
months. A methodological study of six randomized clinical trials was performed.
The claudication distance was assessed with a treadmill test at a constant-load
of 0.82-1.06 Watt/kg. Improvement in initial/absolute claudication distance
(ICD/ACD) ranged from +28% to +213%. The average increase was +150% in ICD, and
+200% in ACD. Exercise rehabilitation significantly improved patient's quality-of
life as well. However, the benefit of exercise training however was only moderate
(6-32%). Exercise training is a very effective therapeutic measure. However, for
further use better guidelines and prospective cost-effectiveness studies
including evaluation of rehabilitation programs with regard to improvements in
functional capacity, modification of risk factors, long-term compliance, quality
of-life and medical costs incurred are needed.
PMID- 10666826
TI - [Antithrombotic therapy and follow-up of peripheral arterial occlusive disease].
AB - In patients with arterial occlusive disease the following antithrombotic drugs
are used to prevent new arterial thromboses: Unfractionated heparin (UFH) and low
molecular weight heparins (LMWH): UFH is frequently used perioperatively in
patients with vascular reconstructions and after peripheral percutaneous
transluminal angioplasty (PTA). Only one study on the longterm use of a LMWH
after operative revascularization has been published, where LMWH led to an
increased patency rate in comparison to acetylsalicylic acid + dipyridamol.
Vitamin-K-antagonists were effective in the prevention of new vascular occlusions
in studies published in the 1970ies. Platelet function inhibitors (aspirine,
ticlopidine and clopidogrel): Aspirine reduced reocclusions after vascular
surgery and PTA. Ticlopidine was effective in the Swedish Ticlopidine-Multicenter
Trial in the prevention of ischemic heart disease and also reduced the need for
vascular surgery. In the CAPRIE-study clopidogrel reduced myocardial infarctions
in patients with peripheral arterial disease in comparison to aspirine.
PMID- 10666827
TI - [Value of vasoactive drugs in conservative therapy of peripheral arterial
occlusive disease].
AB - Based on controlled clinical trials, vasoactive drugs (pentoxyfylline,
naftidrofuryl, buflomedil) and prostanoids (alprostadil, iloprost) are used in
symptomatic peripheral arterial occlusive disease: In stage II, vasoactive drugs
are prescribed in order to improve leg hyperemia in response to muscular work; in
complicated stage II (e.g., non-healing traumatic skin lesions), and in stages
III/IV, prostanoids are given in order to increase forefoot skin blood flow.
These drugs should only be applied if neither angioplasty nor vascular surgery
are recommendable, possible, or successful after complete angiological
diagnostic. It should be considered that these substances have a rather limited
clinical efficacy in both stage II and stages III/IV and therefore attempts
should be made to select patients with a reasonable chance to benefit. These
drugs are also not suitable for primary or secondary prophylaxis against the
progression of vascular lesions.
PMID- 10666828
TI - [Special aspects of therapy of non-atherosclerotic vascular diseases].
AB - The long term course of thromboangiitis obliterans as well as frequency and
extent of major or minor limb amputations depend almost exclusively on the
smoking behaviour of the patients. Superficial phlebitis accompanying an acute
relapse responds well to high-dose aspirin or NSAIDs. Critical limb ischemia is
treated by intra-arterial or intravenous prostaglandins (Alprostadil, Iloprost).
Lokal measures for finger, toe, or foot gangrene do not differ from comparable
sequelae of atherosclerotic vascular disease. Revascularisation procedures
(angioplasty, surgery) have a high rate of technical failure and are indicated
only in rare atypical situations. Corticosteroids are the therapy of choice for
both vasculitides of large muscular arteries, i.e. temporal arteritis (M. Horton)
and Takayasu arteritis. Combination therapy is restricted to steroid refractory
disease; while this is the exception in temporal arteritis, it occurs in up to
50% of patients with Takayasu arteritis. Critical limb ischemia due to giant cell
arteritis may persist even if the inflammatory activity of the disease is well
controlled. Revascularisation procedures in Takayasu arteritis may have good
results; as with all other therapeutic measures in this disease, they should be
provided by specialized centers. Treatment of Raynaud's phenomenon requires
patient evaluation for signs or symptoms of an underlying disease, i.e. some kind
of connective tissue disease. Strength and frequency of attacks depend on a
number of different factors (triggers) which in a given patient may not be
completely understood. Exposition prophylaxis for known triggers and vasodilator
drugs are the main therapeutic measures in Raynaud's phenomenon. Careful
documentation of disease activity provided, non-classical remedies (behavioural
psychotherapy, acupuncture) may be attempted.
PMID- 10666829
TI - [Fibrinolytic, revascularizing therapy of peripheral arterial occlusive disease].
AB - Thrombo-embolic events are the primary or secondary cause for occlusions of
peripheral arteries. The systemically applied fibrinolysis rarely resulted in
revascularization. The local application of plasminogen activators leads to
better results. Combined with interventionally techniques 70-80% of the acute und
subacute occlusions can be opened an the necessity of angio-surgical
interventions can be reduced by about 50%. The technical procedure of the local
fibrinolysis and the dosages of the applied activators are presently not
standardized. Therefore the results of 13 reports between the years 1995-1998
including 4 prospective studies are not comparable. According to the present
experiences, acute und subacute incomplete ischemia syndromes are to be seen as
indication for local lysis. Especially for patients whose constitution is not
optimal for surgery, local fibrinolysis is an alternative to surgical
revascularization. Further studies are necessary to optimize the therapy.
PMID- 10666830
TI - [Possibilities and limits of interventional therapy in chronic peripheral
arterial occlusive disease].
AB - In the therapy of the chronic peripheral vascular occlusion, angioplasty is
rarely used to treat the infra-renal aortic stenosis, whereas the stenosis and
the short occlusion of the iliac artery is a classical indication. Primarily,
stenoses and occlusions of the iliac artery should be treated with balloon
angioplasty exclusively. Only secondarily, when the result of angioplasty was
insufficient, e.g. remaining stenosis or dissection, stent implantation is
appropriate. Angioplasty is most frequently applied in the obliteration of the
femoro-popliteal artery. It can be stated that early- and long-term results are
the better, the shorter the occlusion is. Stent implantation in the femoro
popliteal artery should be avoided because of poor results. Only with the
intention of limb salvage, when there is no opportunity for surgical treatment, a
stent implantation should be considered. In case of recurrent stenoses after
stent implantation, angioplasty can be reapplied with great success. The
indication for any vascular intervention should be a decision of both, the
interventional radiologist and the vascular surgeon, because both kinds of
treatment are palliative and not causal. It is the task of the angiologist to do
clinical diagnostics and the after-treatment. Quality monitoring is
indispensable. It consists of documentation of pre-angioplasty diagnostics and
should be able to prove the correct indication for the intervention. The result
of the intervention should also be documented by angiography and functional
tests. Regular control of the patient after the intervention is necessary for the
early recognition of recurrent stenoses.
PMID- 10666831
TI - [Current status of vascular surgery].
AB - German vascular surgery compares favourably to international standards.
Reconstruction of the complete vascular systems are carried out by experts in
specialized centres. Sophisticated techniques are applied to the open and
intravascular procedures of small and large vessels. Prosthesis grafts and vein
autografts are often used with the help of atraumatic surgical equipment. The
external quality control by the German Society of Vascular Surgery and the
introduction of continuous medical education in vascular surgery help to maintain
this high quality standard. There is a lack of vascular operation, a prerequisite
for the development of further independent centres.
PMID- 10666832
TI - [Cardiovascular risk in arterial vascular surgery reconstruction].
AB - Perioperative cardiac complications can limit the outcome after major vascular
surgery where the underlying severe coronary artery disease is considered to be
the main source. We describe the results of a prospective study including 201
patients undergoing elective vascular surgery. After looking at the encouraging
low complication rate (mortality 0.99%, non-fatal myocardial infarction 2.98%,
cardiac complications 9.95%) we would recommend the discussed diagnostic
strategy. Specialized and expensive cardiac testing should be reserved for a few
cases.
PMID- 10666833
TI - [Promoting quality and quality circles from the viewpoint of established
physicians--representative Bremen and Saxony-Anhalt results].
AB - RESEARCH QUESTION: To study the attitudes of ambulatory care physicians towards
quality improvement, the intentions to join quality circles (QCs, peer review
groups) and the expectations directed towards them. METHODS/SETTING: Survey with
a five-page questionnaire posted to all ambulatory care physicians in the German
states of Saxony-Anhalt (n = 3139) and Bremen (n = 1131). RESULTS: Response rates
were 61.8% in Saxony-Anhalt and 41.7% in Bremen. 2412 questionnaires were
available in this largest survey on that topic in Germany. Necessity of quality
improvement (QI) in ambulatory care was approved by the majority of the
respondents (1.7 on a 5-point Lickert scale). Concerns existed about a rise in
control and the risk of abuse of QI measures. 56.4% in Saxony-Anhalt and 52.3% in
Bremen had the intention to join a QC. Motives and impediments of participation
in QCs were investigated by content analysis. A causal dominance analysis was
performed to identify the key elements for the decision to participate. The main
benefits of QC-participation were expected as assistance in daily practice and
exchange of experiences. The major obstacles were professional and private
duties, fear of control and inefficiency. CONCLUSIONS: Policies that could be
adequate to rise motivations and tackle on widespread fears should be purposely
adapted to the needs and expectations of the physicians.
PMID- 10666834
TI - [Aspects of external quality assurance in anesthesiology--experiences in
Hamburg].
AB - In 1994, external quality assurance in anaesthesia according to the German
Society of Anaesthesiology and Intensive Care (DGAI) was obligatory introduced in
Hamburg. Since 1992 in a pilot project and since 1994 compulsory nearly 500,000
anaesthesias were documented by 39 institutions with a standard data set issued
by the DGAI and transferred to the project office of the Association for Quality
Assurance (EQS) Hamburg. Comparative statistics of these data were produced at
the project office. In the controlling committee and in meetings of the project
participants the contents, policy and results of the project were critically
analyzed and adjustments initiated whenever necessary. With an incidence of 14.1%
of all anaesthesias with special occurrences (AVB), the results are in the same
range compared to most other studies. To evaluate the concept of documentation
the predictory power of single and combined risk assessments for the incidence of
particular AVBs in elective anaesthesias were compared to the predictory power of
ASA-Classification in order to reduce the parameters that had to be collected.
This should lead to a positive influence on the quality of documentation. Besides
one exception, no superior prediction power for AVB incidence could be
demonstrated for any special risk assessment as compared with the ASA
classification. This is also true for the AVBs which are associated with high
lethality. Thus, the documentation of risk factors in the core data set as
predictors can be abandoned without major loss of information. The participants
consider the project to be a useful support for internal improvement projects.
Besides the reduction of the amount of data in quality assurance to get a core of
particularly meaningful parameters the classification of the surgical procedure
by the ICPM- or OPS 301-Code should be integrated into the core data set of the
DGAI. It would lead to an increase in acceptance of the method and thus to an
increase in the validity of its results and valuations.
PMID- 10666835
TI - [The "Hersbruck Model". Application and integration of the DIN EN ISO 9001
quality norms with criteria of the European Foundation for Quality Management in
a clinic].
AB - The german health system has dramatically changed and still continues to do so.
Modified aspects concerning economy, customer orientation, competition, quality
assurance and quality management seem to be increasingly important. Appropriate
response to this challenge demands a relevant adjustment of a quality
"philosophy" within a hospital. The "Hersbruck Model" has proven to be a suitable
approach: on the basis of a quality management system--established and certified
according to DIN EN ISO 9001--it implements all components of the model of the
European Foundation for Quality Management. The modern quality tools as Total
Quality Management and continuous quality improvement allow a permanent increase
of customer/patient satisfaction.
PMID- 10666836
TI - 13C-methacetin breath test: isotope-selective nondispersive infrared spectrometry
in comparison to isotope ratio mass spectrometry in volunteers and patients with
liver cirrhosis.
AB - The 13C-methacetin breath test (MBT) has been proposed for the noninvasive
evaluation of the hepatic mixed function oxidase activity. Up to now, stable
isotope analysis of carbon dioxide of the MBT has been carried out with isotope
ratio mass spectrometry (IRMS). The aim of the present study was to test a
recently developed isotope-selective nondispersive infrared spectrometer (NDIRS)
in comparison to IRMS in healthy volunteers and patients with liver cirrhosis.
Ten healthy volunteers (range 22 to 76 years) and ten patients with
histologically proven liver cirrhosis (range 47 to 71 years; Child Pugh score A =
5, B = 3, C = 2) were studied. After an overnight fast each subject received 2
mg/kg BW of 13C-methacetin dissolved in 100 ml of tea. Breath samples were
obtained before substrate administration and after 5, 10, 15, 20, 30, 40, 50, 60,
80, 100, 120, 150, 180 min. The 13C/12C-ratio was analyzed in each breath sample
both by NDIRS (IRIS, Wagner Analysen Technik, Worpswede, Germany) and CF-IRMS
(ABCA, Europa Scientific, Crewe, UK). Results were expressed as delta over
baseline (DOB [/1000]) and as cumulative percentage doses of 13C recovered (cPDR
[%]) at each time interval. Correlations between IRMS and NDIRS were tested by
linear regression correlation. For measuring agreement an Altman-Bland-plot was
performed. Applying correlation analysis a linear correlation was found (DOB: y =
1.068 +/- 0.0012.x + 2.088 +/- 0.2126, r = 0.98, p < 0.0001; cPDR: y = 1.148 +/-
0.0109.x + 0.569 +/- 0.172; r = 0.99, p < 0.0001). For DOB the mean difference
(d) was 2.9/1000 and the standard deviation (SD) of the difference was 2.7/1000.
The limits of agreement (d +/- SD) were -2.5/1000 and 8.3/1000. The comparison of
DOB- and cPDR-values by NDIRS and IRMS shows a high linear correlation. However,
the distance of the limits of agreement is wide. Consequently, the validity of
the MBT could be influenced which could make MBT by NDIRS unprecise for exact
evaluation of hepatocellular dysfunction. Further studies are necessary to
determine sensitivity and specifity of the MBT with NDIRS in larger study
populations.
PMID- 10666837
TI - Evaluation of an enzyme immunoassay for detecting Helicobacter pylori antigens in
human stool samples.
AB - BACKGROUND AND AIM: So far, the detection of Helicobacter pylori (Hp) infection
by stool analysis appeared to be almost impossible. With the Premier Platinum
HpSA EIA a new enzyme immunoassay was developed for diagnosis of Hp infection,
using polyclonal antibodies against Hp antigens in human stool. We evaluated this
new test in its diagnostic accuracy in comparison to established reference
methods. METHODS: From 54 consecutive patients (29 male, 25 female, age: 19 to 85
years) undergoing routine upper gastrointestinal endoscopy antral and corpus
biopsies were taken for histology and Helicobacter urease test (HUT). Endoscopy,
13C-urea breath test (13C-UBT), serology, and stool probes sampling were
performed within two days. Stool samples were aliquoted after reception and
stored frozen (-20 degrees C) until tested. The Premier Platinum HpSA test
(Meridian, Connecticut, Ohio, USA) was performed according to the manufactures
protocol. Patients were considered to be infected with Hp if two of the four
reference tests were positive. RESULTS: 28 of the 54 patients were Hp-infected.
Only one of these was found to be false-negative by the HpSA EIA. Two false
positive results were obtained in the noninfected group (sensitivity 96.4%,
specificity 92.3%). CONCLUSION: In this group of patients investigated, the novel
HpSA Enzyme Immunoassay (EIA) proved to be highly accurate for diagnosis of Hp
infection. Collection and testing of stool are noninvasive and easy to perform,
therefore this test will become an important tool for diagnosing Hp infection in
clinical practice.
PMID- 10666838
TI - [A new papillotome for cannulation, pre-cut or conventional papillotomy].
AB - A new papillotome was designed to overcome certain drawbacks of the needle-knife,
that is most commonly used for precut sphincterotomies. The intention was to
develop an instrument at least as good as the needle-knife or the Erlangen-type
precut papillotome for precut procedures. In addition, it had to be suitable for
direct cannulation of the biliary or pancreatic duct. PATIENTS AND METHODS:
According to a prospective protocol 54 patients in whom a papillotomy was
indicated were examined with the new instrument. The protocol allowed three
futile attempts to cannulate or two inadvertant cannulations of the pancreatic
duct with a standard cannula and hydrophilic guide wire before a precut was
performed. The new baby-papillotome has a diameter of only 1 mm and a short 10 mm
cutting wire. Similar to a guide wire it is introduced via a 6F- or 7F-introducer
catheter. RESULTS: Cannulation of the desired duct (the bile duct in 48 patients,
the pancreatic duct in five patients, Billroth II anatomy in three patients) was
successful within one session in 98% (53/54). In one patient, the bile duct was
successfully cannulated in a second session using the baby-papillotome, resulting
in an overall success rate of 100%. Primary cannulation using the new papillotome
without precut was obtained in 24% (13/54). Complications were mild pancreatitis
in one patient and nonsignificant bleeding in three (immediate endoscopic
hemostasis in all, no transfusions, no drop of hematocrit). There were no serious
complications. CONCLUSION: The new baby-papillotome is suitable for precut as
well as for primary cannulation. In this first series, the desired duct was
cannulated in 98% within the first session with a low complication rate. Further
studies of the new instrument seem desirable.
PMID- 10666839
TI - [Prevalence of cholecystolithiasis in South Germany--an ultrasound study of 2,498
persons of a rural population].
AB - Gallbladder stones represent one of the most common reason for morbidity in
western industrial nations. There remains a paucity of exact information
regarding the prevalence and risk factors for this disease entity in Germany. As
part of a whole-community survey focusing on the prevalence of echinococcosis
multilocularis conducted in a population in southwestern Germany (response rate:
66.6%), 2,560 subjects underwent an upper abdominal ultrasound examination at
which the presence of gallbladder stones was ascertained. In each case, upper
abdominal sonography was performed following completion of a standardized
interview. In 62 subjects, the gallbladder could not be adequately visualized due
to an insufficient fasting period; the remaining 2,498 subjects (1,326 females,
age 38.9 +/- 19.9 years; 1,172 males, age 37.7 +/- 18.8 years) were included in
the study collective. Gallbladder stones (sonographically visualized gallbladder
stones or history of cholecystectomy for cholecystolithiasis) were found in 196
participants (7.8%; 139 females [10.5%] versus 57 males [4.9%]). Statistical
treatment of the data using multiple logistical regression techniques revealed a
significant influence of the variables age, gender, body mass index (BMI) and
positive family history on the development of gallbladder stones. The prevalence
of gallbladder stones in the present study population is lower than figures
reported for a study in Brandenburg and at 7.8% is rather low in comparison with
other European studies. One explanation may be the low average age of study
participants, almost 50% of whom were less than 35 years. Besides age, subjects'
gender, BMI and positive family history were identified as significant risk
factors.
PMID- 10666840
TI - [Long-term collagenous sprue--remission with a gluten-free diet].
AB - We report on a 56-year-old caucasian female, 154 cm, 38 kg, who was admitted to
the hospital in extremely poor, cachectic condition with pretibial edemas,
ascites and pleural effusion with a history of severe watery diarrhea up to 15
times daily. The patient's history with permanent meteorism, recurrent episodes
of watery diarrhea and dystrophy dates back to her early childhood. Multiple
biopsies from the distal part of the duodenum showed a complete atrophy of villi
with an extensive subepithelial layer of collagenous fibers. No antigliadin or
antiendomysial antibodies could be detected. Under a strictly gluten-free diet,
the patient's symptoms quickly improved. During the follow-up of one year, no
recurrence of diarrhea and meteorism has been seen. The patient showed a
continuous improvement of her general condition and nutritional state with a
weight gain to 50 kg. Repeated control biopsies still revealed a pronounced
villous atrophy. However, no subepithelial collagenous fibers were detectable. A
diagnosis fitting to the patient's clinical symptoms of severe malabsorption,
would be the rare "collagenous sprue", which is considered to be gluten
insensitive. However, the patient's good response to a gluten-free diet raises
the possibility, that the collagenous layer represents a manifestation of more
severe forms of common celiac disease. In this case, it would not be necessary to
regard collagenous sprue as a distinct entity.
PMID- 10666841
TI - Autologous blood donation for surgery in inflammatory bowel disease--a report of
six cases.
AB - BACKGROUND: Surgery in inflammatory bowel disease (IBD) is frequently associated
with need for perioperative blood transfusions carrying the potential risk of
infection. Autologous blood donation is often limited by IBD-associated anemia
which is reversible by intravenous iron and erythropoietin. We therefore tested
the feasibility of autologous blood donation in IBD. METHODS: Six patients (five
Crohn's disease, one ulcerative colitis) with indication for elective bowel
resection were treated after informed consent was obtained. Two to four blood
donations were scheduled during four weeks prior to surgery. Once a week 350-450
ml of blood were collected from patients with a hemoglobin level above 11.0 g/dl.
After each donation 200 mg of iron saccharate diluted in 0.9% saline were given
to all patients intravenously as substitute for donation-related iron loss.
Patients with preexisting anemia or C-reactive protein above 2.0 mg/dl received
concomitant erythropoietin. RESULTS: The scheduled number of packed red cells was
donated successfully by four patients. Due to low hemoglobin levels two patients
donated one unit less than intended. Four patients received autologous blood
transfusions intra- or postoperatively. No patient needed homologous blood. No
serious adverse events were observed during blood donations, perioperatively, and
during the one year follow-up period. CONCLUSION: Preoperative autologous blood
donation is save and feasible in IBD patients with elective bowel resection.
PMID- 10666842
TI - [Treatment of multilocular hepatocellular carcinoma (HCC) of 4.5 cm and 3.5 cm
diameter using percutaneous ethanol injection in a patient with advanced liver
cirrhosis].
AB - Treatment of hepatocellular carcinoma (HCC) with percutaneous ethanol injection
(PEI) is established for tumors up to 3 cm. We report on treatment of a
multilocular HCC with a maximum size of 4.5 cm. CASE REPORT: In a 76-year-old
woman with a liver cirrhosis (Child C) due to chronic hepatitis C HCC with two
nodules (diameter 3.5 cm and 4.5 cm) was diagnosed. Because of the patient's
reduced general state of health and the advanced cirrhosis surgical treatment and
chemoembolization were declined. The two nodules were treated in ten settings
during 15 weeks under ultrasound guidance with 85 ml of 96% ethanol. There were
no severe side effects. The patient's general condition improved and serum alpha
fetoprotein concentration decreased from 21,126 to 800 micrograms/l. Seven months
after the diagnosis of the HCC she was admitted to another hospital due to a
cerebral hemorrhage. A few days later she died because of a pneumonia. In spite
of detailed micro- and macroscopically investigation no tumor was found during
the autopsy. This case report shows that HCC up to a diameter of 4.5 cm can be
effectively treated by PEI. This treatment modality is cheap and well-tolerated
even in patients suffering from advanced cirrhosis.
PMID- 10666843
TI - [Hereditary hemochromatosis--new developments after discovery of the HFE gene].
AB - Hereditary hemochromatosis (HH) is an autosomal recessive disorder of iron
metabolism, resulting in an increased iron deposition and multiorgan failure.
Recently a candidate gene of HH, termed HFE, has been identified on chromosome 6,
coding for a protein homologous to major histocompatibility complex (MHC) class I
molecules. Two mutations of the hemochromatosis gene leading to an exchange of
cysteine to tyrosine at aminoacid 282 and histidine to asparagine at aminoacid
63, are retained responsible for the development of hereditary hemochromatosis.
The Cys282Tyr-mutation disrupts a disulfid bond and thus abrogates binding of the
mutant HFE-protein to beta 2-microglobulin and its presentation on the cell
surface. The His63Asp-mutation seems to play a role in pH-regulated dissociation
of the transferrin receptor/transferrin complex in the lysosome. Mutations of the
HFE-protein alter the affinity of the transferrin receptor for its ligand
transferrin and may thus cause an intracellular accumulation of iron. Knowledge
of the responsible gene allows a molecular diagnosis of HH. The new genetic
marker can be used for screening and confirmation of HH reducing the need for
confirmatory liver biopsies. Compared to standard screening parameters like
ferritin and transferrin saturation genetic testing will allow the diagnosis of
HH in an early, asymptomatic state before iron accumulation has occurred. As a
normal life expectancy of patients with HH can be achieved if iron reduction is
initiated early, genetic testing may thus be of great benefit for patients with
HH.
PMID- 10666844
TI - [Gene therapy of pancreatic carcinoma].
PMID- 10666845
TI - [Incidence and prognosis of collagenous and lymphocytic colitis].
PMID- 10666846
TI - [Identification of CD81 protein as HCV receptor--relevance for pathogenesis and
cell tropism?].
PMID- 10666847
TI - [Evidence-based evaluation of the back school. Wide distribution with minimal
effectiveness?].
PMID- 10666848
TI - [Tissue engineering of bone tissue].
PMID- 10666849
TI - [Torsion changes in the throwing arm of handball players].
PMID- 10666850
TI - [Orthopedics and geriatrics].
PMID- 10666851
TI - [Incidence of joint-specific risk factors in patients with advanced cox- and
gonarthroses in the Ulm Osteoarthrosis Study].
AB - AIM OF STUDY: To determine the prevalence of joint specific risk factors in
patients with different patterns of advanced hip and knee osteoarthritis (OA).
METHODS: We performed a cross-sectional multicenter study in four orthopaedic
hospitals in the southwest of Germany. A detailed medical history (date and
nature of trauma, conservative and surgical treatment of congenital or acquired
joint disorders known as secondary causes of OA) and radiographic evaluation
(sequelae of hip dysplasia, slipped capital femoral epiphysis or other
malformations) was obtained in 809 patients with advanced hip (n = 420) or knee
(n = 389) osteoarthritis, which required unilateral total joint replacement.
According to the presence or absence of joint specific risk factors, patients
were classified as having secondary or primary (idiopathic) OA. RESULTS: In 41.7%
(25.5%) of patients with hip OA and 33.4% (11.1%) of patients with knee OA some
predisposing abnormality of the operated (or contralateral) joint could be
observed. In hip OA the underlying pathological conditions were mainly hip
dysplasia (25.0% in the operated joint and 14.8% in the non-operated joint) and
slipped capital femoral epiphysis (7.1% and 14.8%), while knee OA was most often
associated with a history of severe trauma (28.6% and 8.3%) CONCLUSION: While
there is a lack of comparable investigations in patients with advanced knee OA,
the presented data is somewhat contradictory to earlier reports of the prevalence
of identified underlying risk factors in patients with hip OA. The reported
differences, however, might be attributed to different methodological approaches
and could also resemble recent changes in the multifactorial ethiopathologic
concept of OA.
PMID- 10666852
TI - [Diagnosis and therapy of spinal stenosis in the elderly].
AB - PROBLEM: Spinal stenosis is a common and increasing problem in the elderly
population and a diagnostic and therapeutic challenge. METHODS: An overview of
etiology, epidemiology, diagnostics and therapy is given based on a literature
review of the years 1978-1998 and experiences since 1985. RESULTS: Dealing with
spinal stenosis we have to distinguish concerning diagnostics and therapy between
cervical and lumbar spinal stenosis. The cardinal symptom of the lumbar spinal
stenosis is the claudicatio spinalis and of the cervical spinal stenosis the
cervical myelopathy occasionally combined with radiculopathy. The first
therapeutic step should be the conservative therapy in nearly all cases, the only
exception is a severe cervical myelopathy where an operation is indicated. In
case of persistent or progressive symptoms under a sufficient conservative
therapy, operative therapy is indicated. The different possible therapy decisions
will be based on flow-charts. CONCLUSION: Whereas in lumbar spinal stenosis the
indication for operative therapy should be considered with reservation, in
cervical spinal stenosis with myelopathy operative therapy should be considered
at an early stage.
PMID- 10666853
TI - [Epidemiology of accidental falls in the elderly].
AB - INTRODUCTION: There is a lack of epidemiological data on falls and fall-related
injuries for the aged population in Germany. The purpose of the article is to
present the available data focusing on the incidence of the fracture types that
carry the highest risk for mortality, hospitalization and persisting
disabilities. METHODS: The paper reports on a 10% representative sample that was
drawn by the Federal Bureau of Statistics. A medline search for 1980-1998 was
performed to identify relevant articles. The OECD database was used for mortality
rates after injurious falls. If no sufficient data were published for Germany,
incidence rates of demographic comparable European regions are reported. RESULTS:
The number of fractures of the lower extremity (ICD 820-829) followed by
hospitalization was 139,000 in 1996 for elderly (65+ years). Fractures of the
upper extremities (ICD 810-819) requiring hospitalisation were reported for
65,000 persons aged 65+ years and head trauma (ICD 850-851) followed by
hospitalization in this age group for 29,000 persons. There remains an
information gap on the incidence of falls and fall-related sequelae without
hospitalization in Germany. CONSEQUENCES: Facing, the demographic transgression
the prevention of falls and fall-related injuries gains a high priority.
Operative management and rehabilitation procedures for elderly trauma patients
should be further evaluated and improved.
PMID- 10666854
TI - [Fractures of the upper extremity in the elderly].
AB - PROBLEM: The primary goal in treating fractures in elderly persons is safe and
rapid restoration of their functional capabilities to secure independence in
everyday activities. The intention of this paper is to present an overview of
treatment principles useful in this age group. METHODS: We analysed a series of
404 patients above the age of 70 years who underwent surgery for fractures of the
arm between 1981 and 1997. RESULTS: Diaphyseal fractures are less frequent in
this age group and their treatment does not differ significantly from principles
established for younger patients. The majority of fractures of the proximal
humerus and the distal radius can be treated by conservative means. Unstable
fractures are frequent in the distal humerus and the olecranon requiring
operative reduction and osteosynthesis. CONCLUSIONS: Preferred operative
techniques in aged persons inflict minimal surgical trauma and have a low rate of
complications and secondary interventions. In contrast, anatomical reconstruction
has the highest priority in younger individuals.
PMID- 10666855
TI - [Therapy of para-articular hip fractures in the elderly].
AB - Fractures of the hip in old patients are life-threatening events. A steady
increase of that fracture type is likely in the near future. Surgical therapies
and strategies have to consider the special requirements and problems of
geriatric patients to achieve better results. They have to be designed together
with new concepts of geriatric rehabilitation programmes. MATERIAL AND METHODS:
In 1992 148 patients with hip fractures were treated at the department of
traumatology, University Ulm. Follow-up parameters were daily activities in life
pre- and postoperatively as well as mortality, type of fracture and surgical
treatment. RESULTS: There were 79 femur fractures of the collum and 69 fractures
of the trochanteric region. Mean age was at 81.2 and 81.9 years respectively (68
f/11 m versus 52 f/13 m). At the time point of accident 84 patients lived at home
whereas the remaining stayed at a nursing home. The highest mortality was found
in patients living in a nursing home (93%). The overall mortality one year
following the trauma was 26%. 50% of the patients had hip prosthetic replacement,
the remaining received a gliding screw, 9 patients a proximal femoral nail or lag
screws (n = 6). CONCLUSION: Our results demonstrate that hip fractures in
geriatric patients have a high mortality, especially in those living in a nursing
home. The surgical concepts should aim to reduce that number and to allow the
same daily activity of life as preoperatively. The main part in these concepts is
an early start of geriatric rehabilitation. There are at least two groups. On the
one hand, the active old patient who acquires his fracture during an activity. In
this cases the aim must be the full rehabilitation and afterwards returning to
normal environment. On the other hand there are the patients living in a nursing
home who have the highest risk of injury related death. In these patients the
first aim must be prevention of the accident.
PMID- 10666856
TI - [Thoracoscopic interventions in deformities of the thoracic spine].
AB - AIM OF THE STUDY: We prospectively studied 9 patients with deformities of the
thoracic spine who underwent thoracoscopic surgery to critically evaluate the
benefits and limitations of thoracoscopy. METHODS: Seven patients with
deformities of the thoracic spine (5 scoliosis, 2 kyphosis) underwent a
thoracoscopic release and posterior correction and fusion in a single stage. In
one case of a crankshaft-phenomenon a thoracoscopic epiphyseodesis und in another
case of a posttraumatic kyphosis a thoracoscopic instrumentation and fusion were
performed. The average age was 21 years, the follow-up was 18 months with a
minimum of 12 months. The perioperative data including complications were
collected and a radiographic analysis concerning curve correction was carried
out. RESULTS: The scoliotic curves measured preoperatively 84 degrees on average
with a Cobb angle of 62 degrees on the traction films and were corrected by 57%
to averagely 36 degrees at follow-up. In the two cases of Scheuermann kyphosis a
preoperative kyphosis of 94 degrees respectively 82 degrees was corrected to 52
degrees respectively 58 degrees. Between 4 and 5 discs were excised with an
average operative time of 160 min and a blood loss of 380 ml. A conversion to
open thoracotomy was not necessary in any case. There were no intraoperative
neurovascular complications. CONCLUSIONS: Thoracoscopic procedures in deformities
of the thoracic spine are technically demanding; however, it is a minimally
invasive procedure with a reduced approach-related morbidity compared to open
thoracotomy. The indications for a thoracoscopic release are rigid kyphosis and
scoliosis with rigid curves between 80 and 90 degrees Cobb angle in which an
anterior correction and instrumentation alone is not considered.
PMID- 10666857
TI - [Guillain-Barre syndrome as differential diagnosis of intervertebral disk-induced
nerve root compression].
AB - INTRODUCTION: Diagnosis of Guillian-Barre Syndrome usually is not difficult, but
diagnostic failure occurs for the variable initial presentation. Diagnosis is
based on physical examination showing loss of motor strength in more than one
limb and loss of deep tendon reflexes. Ventilatory assistance, pharmacologic
maintenance of cardiovascular homeostasis, corticosteroids, IgG and plasma
exchange are the dominant therapeutic measures. CASE: This article reports on a
case of a 59-year old surgeon suffering from degenerative disc disease in the
lumbar spine. The patient developed a severe course of the Guillian-Barre
Syndrome with persisting motor weakness of the legs. CONCLUSION: If the primary
problem at presentation is limb and back pain the pathology appears to be in the
musculoskeletal rather than in neurological system. The awareness of this
presentation of Guillian-Barre-Syndrome will eliminate delay in diagnosis.
PMID- 10666858
TI - [Early diagnosis of isthmic spondylolysis with MRI].
AB - INTRODUCTION: Early diagnosis of isthmic lumbar spondylolysis cannot always be
established on plain radiographs and CT scans, only. In the case presented here,
magnetic resonance imaging (MRI) showed typical bone marrow changes in T1- and T2
weighted images, even at an early stage. CASE: A 11-year old female judoka
complained of deep lumbar pain with local tenderness to pressure at L3 to S1.
Clinically, there was no neurologic deficit. Conventional x-ray showed no
abnormalities. In contrast, MRI revealed a locally ill-defined bone marrow oedema
in both pars interarticularis of the 5th lumbar vertebra. This was interpreted as
the typical MR-tomographic feature of occult stress fracture, which has to be
seen as early evidence of isthmic spondylolysis. Complete restitution was
achieved after conservative treatment. CONCLUSION: In early spondylolysis-
presented here in form of a case report--, changes of MR signal intensity in the
pars interarticularis may be detected, even before fracture lines are to be seen
on plain radiographs. Further studies are necessary to confirm MRI to be the
method of choice for early diagnosis.
PMID- 10666859
TI - [Mannerfelt arthrodesis of the wrist joint in patients with chronic
polyarthritis. A retrospective analysis of 24 cases].
AB - AIM: Mannerfelt established his technique of wrist arthrodesis with stabilisation
by an intraosseous rushpin as a secure method for patients with rheumatoid
arthritis. This study was performed to evaluate the mid-term results in a
consecutive group of patients. METHODS: Out of a group of 39 operations 24 wrist
arthrodeses (61%) in 19 patients have been followed 12-96 months postoperatively
(average 44 mths) by clinical testing and radiographic examination. All
operations were performed in the original technique. All patients suffered from
rheumatoid arthritis in an advanced stage (Larsen III-V). RESULTS: All but one
patient were free of pain. Function and strength of the hand increased
significantly in all patients. All patients had additional resection of the ulnar
head that led to normal pro-supination of the forearm. 18 patients were very
satisfied with the result of the procedure. All but one of the wrists showed
complete fusion. In one case there was an intraoperative perforation of the pin
through the radial cortex, in another case we saw a fissure of the shaft of the
third metacarpal bone. One patient showed a dysesthesia in the third finger.
CONCLUSION: The results in this group of patients confirmed the advantages of
Mannerfelt's technique such as simple operative technique, high fusion rate and
low incidence of complications.
PMID- 10666860
TI - [Functional and socioeconomic outcome of inpatient rehabilitation of patients
with complex hand injuries].
AB - PURPOSE: Evaluation of functional outcome and socio-economic results of patients
with complex hand injuries after inpatient rehabilitation. PATIENTS AND METHODS:
In a prospective investigation 36 patients with complex hand injuries received an
intensive therapy regime under inpatient conditions. In all patients functional
parameters of the hand (total active range of motion, palm to palm distance,
spread between thumb and index finger, spread between thumb and little finger)
and the score of Buck-Gramcko were registered initially and at the end of
inpatient rehabilitation. Socio-economic data (kind of discharge, job
reintegration, further treatment) were documented as well. RESULTS: The total
active range of motion could be improved from 36% to 69%, spread D1-D5 from 18.5
to 20.7 cm and spread D1-D2 from 13.9 to 15.6 cm. The palp to palm distance of
all fingers was reduced from 4.6 cm to 2.3 cm. The Buck-Gramcko score of all
injured fingers improved from 4.2 points (poor) at admission, to 11.8 points
(good) at discharge, At the end of inpatient rehabilitation 18 patients could
return to their job either gradually or on full-time. CONCLUSION: Even patients
with complex hand injuries, good functional results could be achieved by an
intensive inpatient rehabilitation characterised by close medical supervision and
guidance and tight clinical controls.
PMID- 10666861
TI - [Hallux valgus: a therapy concept and its outcome from 1993 to 1996].
AB - INTRODUCTION: Aim of this study is to present the treatment concept and the
results of hallux valgus surgery of our department. PATIENTS AND METHODS: The
criteria for decision making are 1st intermetatarsal angle, congruency of the
first metatarsophalangeal joint and sesamoid position. According to our concept
we performed between 1993 and 1996 42 Chevron osteotomies for mild, 138 Chevron
with lateral soft tissue release (Chevron + LSR) for moderate and 93 basal
crescentic (Mann) osteotomies with lateral soft tissue release for severe hallux
valgus deformities. RESULTS: 31 Chevron, 118 Chevron with lateral soft tissue
release and 80 basal crescentic osteotomies (Mann) were seen at an average follow
up of 19 months (12-29) after a Chevron, respectively. 16 months (12-43) after
Chevron with lateral soft tissue release and 18 months (12-32) after a basal
crescentic osteotomy. 83% of all patients classified the results of the surgery
as "very satisfactory" and "satisfactory". The average hallux valgus angle was
corrected from preoperatively. 25.3 degrees (Chevron), 29.9 degrees (Chevron +
LSR) and 41.8 degrees (Mann) to 16.5 degrees (Chevron), 12.1 degrees (Chevron +
LSR) and 14.1 degrees (Mann) at final follow up, the average first
intermetatarsal angle was corrected from preoperatively 12.1 degrees (Chevron),
14.0 degrees (Chevron + LSR) and 17.4 degrees (Mann) to 7.9 degrees (Chevron),
5.8 degrees (Chevron + LSR) and 7.8 degrees (Mann) at final follow up.
CONCLUSION: Our analysis of the three osteotomies revealed that with this
differentiated concept we were able to achieve excellent and good results in more
than 80% of our patients. Only with a treatment plan that includes different
procedures to address the various stages of hallux valgus can one achieve the
optimum result for the patient.
PMID- 10666862
TI - [Osteogenesis in exposure to ionizing radiation in vitro].
AB - Irradiation is a well established therapeutical concept to prevent heterotopic
ossification after joint replacement. The influence of irradiation on
proliferation of mature osteoblasts and their potential osteoprogenitors, matrix
formation and mineralization are not well known in this setting. We therefore
studied the effect of different doses of ionizing irradiation on the several
steps of osteogenesis in vitro, using cells isolated from the juvenile rat. A
colony forming test, the MTT-viability assay, a cell count, measurement of the
cellular protein content and alkaline phosphatase activity, as well as
determination of in vitro mineralisation have been applied to calvarian
osteoblasts, fibroblasts and stromal bone marrow cells. Irradiation results in a
dose-dependent suppression of clonogenic activity in all mitotically active
cells, but metabolic activity and matrix synthesis were not impaired. In dense
cultures alkaline phosphatase expression and in vitro mineralisation were not
significantly affected by irradiation. Our experimental in vitro data suggest
that irradiation inhibits the initial phase of in vivo osteogenesis due to the
cytostatic effect. Postoperative irradiation after THR must therefore take place
as early as possible. The homoeostasis of normal, orthotopic bone does not seem
to be severely affected by local low-dose irradiation.
PMID- 10666863
TI - [Heparin-induced thrombocytopenia after elective hip joint replacement with
postoperative prevention of thromboembolism with low-molecular-weight heparin].
AB - BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a severe side effect of the
prophylaxis of venous thromboembolism with unfractionated heparin. The aim of the
present study is to gain more information on the incidence of HIT during
prophylaxis of venous thromboembolism with low-molecular-weight heparin in
elective hip surgery. METHODS: 586 consecutive patients were included into the
prospective study, who were admitted to hospital for elective hip replacement.
The incidence of thrombocytopenia, clinically manifest venous thromboembolism and
of the heparin-induced IgG antibodies were analysed during prophylaxis with low
molecular-weight heparin. Patients received once daily subcutaneously low
molecular-weight heparin for a mean of 28 days postoperatively. Platelet counts
and clinical examinations for the presence of venous thromboembolism were done at
days 0, 2, 7 (+/- 1) and 12 (+/- 2). Heparin-induced IgG antibodies were
determined before and after a 12 (+/- 2) days prophylaxis with low molecular
weight heparin in 265 of 586 patients randomly. Patients were reexamined for
thromboembolic complications after 3 and 6 months. The clinical suspicion of
thromboembolic complication was documented objectively. RESULTS: None of the
patients developed a decrease of platelets of < 50% of the initial value. Ten of
265 patients had elevated IgG antibodies against heparin/platelet factor 4 before
prophylaxis (3.8%). After the 12 (+/- 2) days prophylaxis 13 of 265 patients had
elevated IgG antibodies (4.9%). C14 serotonin assay was positive in 0 of 10
patients before treatment and in 3 of 19 patients at day 12 (+/- 2). Ten patients
developed venous thromboembolism postoperatively (8 x deep venous thrombosis, 2 x
pulmonary embolism, no fatal embolism). Only 1/19 patients with elevated
antiheparin IgG titres developed venous thromboembolism. The C14 serotonin assay
was negative in this patient. Two patients died in the postoperative phase due to
underlying cardiovascular diseases. CONCLUSIONS: In patients with elective hip
replacement prophylaxis of venous thromboembolism with low molecular-weight
heparin was associated with a very low incidence of HIT, and hence screening for
HIT antibodies is not required.
PMID- 10666864
TI - [Collagen type VI content in healthy and arthritis knee joint cartilage].
AB - AIM OF THE STUDY: Since collagen type VI seems to play an important role in
cartilage metabolism and is increased in osteoarthritis, the aim of this study
was to investigate whether different stages of osteoarthritis can be
characterised by the content of collagen type VI in human knee cartilage.
MATERIAL AND METHODS: Collagen type VI was investigated in 148 histologically
normal and 117 osteoarthritic cartilage samples from 18 different localisations
of human knee joints. It was quantified in cartilage extracts using an inhibition
ELISA. RESULTS: In normal cartilage the average content of collagen type VI was
0.48 per cent of total collagens. Interestingly, there was a high variability not
only in osteoarthritic, but also in normal cartilage. The statistical analysis
showed significant differences between normal femoral, tibial or retropatellar
cartilage samples. Therefore, normal and osteoarthritic samples from different
localizations had to be compared separately. A significant increase of collagen
type VI was already found in early osteoarthritic lesions. CONCLUSIONS: Inspite
of a statistically significant increase of collagen type VI in osteoarthritic
cartilage, the range of concentrations found in normal and osteoarthritic samples
overlap. In view of the high interindividual variability, collagen type VI is not
very precise in the diagnosis of early osteoarthritic lesions if used as the only
marker.
PMID- 10666865
TI - [Hemostaseology and pre-eclampsia].
PMID- 10666866
TI - [Pre-eclampsia--endothelial damage of endothelial activation?].
AB - There is considerable evidence that endothelial damage, followed by the release
of vasoactive substances contributes to the pathophysiology of preeclampsia.
Because of controversial experiences in literature we wanted to evaluate the
potential cytotoxic effect of preeclamptic sera on cultured endothelial cells.
Therefore cultured human umbilical vein endothelial cells (HUVEC) were stimulated
with sera obtained from preeclamptic patients, while sera from normotensive
pregnant and nonpregnant women served as controls. To prove the viability of
these cells we performed ethidiumbromide/acridinorange immunostaining and
determined t-PA/PAI-1 release into the supernatant. These experiments could not
show any cytotoxic effect on endothelial cells. In ongoing studies we measured
the concentrations of adhesion molecules, markers of endothelial activation, in
maternal sera, in the supernatant of cultured endothelial cells, and on cell
surface after stimulation with the above mentioned sera. In the supernatant we
couldn't determine any different concentrations of adhesion molecules after
stimulation with the different sera, but using immunofluorescence-microscopy an
increased concentration of those molecules could be detected on the endothelial
surface after stimulation with preeclamptic sera than compared to sera from
normotensive controls. In conclusion, our experiments support the hypothesis that
sera from preeclamptic women may cause endothelial activation.
PMID- 10666867
TI - [Thrombocyte activation in pre-eclampsia].
PMID- 10666868
TI - [Trophoblast invasion in pre-eclampsia].
AB - It is generally accepted that insufficient invasion of trophoblast cells into the
myometrial portions of the spiral arteries is thought to play a crucial role in
the development of preeclampsia. As a consequence, uteroplacental vessels fail to
undergo adaptive changes which are imperative to provide a sufficient blood
supply to the placenta. Consecutive placental hypoxia is supposed to cause
secretion/shedding of still unidentified placental metabolites resulting in
different forms of pregnancy-induced hypertension. This review presents published
data concerning the causes of insufficient trophoblast invasion in preeclampsia.
Expression of HLA-G by extravillous trophoblast cells seems to be altered,
resulting in activation of the maternal immune system. The pattern of integrin
expression as well as the secretion of proteases is reported to be disturbed,
which could lead to a reduced invasive potential of the trophoblast cells. Recent
data indicate a pathophysiological role of NK-cells and macrophages in the
altered trophoblast invasion. Also angiotensinogen Thr235 polymorphism seems to
alter early physiologic changes in spiral arteries. In summary, preeclampsia
seems to be induced by a multifactorial disturbance of trophoblast invasiveness
which is characterized by reduced invasiveness of the trophoblast cells
themselves and by an activated maternal immune response blocking the invasion by
the semiallogenic trophoblast.
PMID- 10666869
TI - [Animal experiment models of hypertension in pregnancy--an alternative to
clinical studies?].
AB - Because of ethical constraints upon research during human pregnancy and of the
heterogeneity of preeclampsia a number of experimental animal models were used to
study pathophysiology of preeclampsia. We reduced the uteroplacental flow by
aortic clip technique in 72 SHR-rats in 4 groups (G 1 not gravid--no clip, G 2
not gravid--aortic clip, G 3 gravid--no clip, G 4 gravid--aortic clip). While
gravidity normalised blood pressure in SHR (G 3), reduction of the uteroplacental
flow significantly increased maternal blood pressure (G1 240/180 mmHG, G2 238/183
mmHg, G3 148/99 mmHG, G4 200/145 mmHg) and leads to significant higher
hematocrit, significant lower plasma renin activity and aldosterone plasma
concentration, as it is found in human superimposed preeclampsia. SDS-page
electrophoresis proved a significant increase of urinary high density proteins.
CONCLUSION: In comparison to chronical inhibition of NO-synthesis or chronical
application of ultra-low-doses-endotoxin, reduction of uterine flow by aortic
compression is a reliable animal model and leads in SHR to a superimposed
preeclampsia-like syndrome with many similarities to human clinical findings.
Animal models for preeclampsia are no alternative to clinical studies, but they
are furthering our understanding of pathophysiology in many fields.
PMID- 10666870
TI - [Significance of the renin-angiotensin-aldosterone system for pathogenesis and
early diagnosis of pregnancy-induced hypertension with special reference to
mineralocorticoid receptors].
AB - OBJECTIVE: In women with pregnancy-induced hypertension (PIH) the density of
mineralocorticoid receptors (MR) in human mononuclear leukocytes (HML) is reduced
compared with healthy pregnant women. The same applies to plasma levels of
aldosterone and 18-hydroxycorticosterone. In this study, we investigated whether
alterations of these parameters preceded the development of clinical symptoms
and, therefore, might be potential predictors of PIH involved in the
pathogenesis. PATIENTS AND METHODS: In eighty-four women belonging to the risk
group for PIH but not showing any symptoms neither of PIH nor preeclampsia (PE)
we characterized prospectively before the onset of disease in the second
trimester of pregnancy mineralocorticoid receptor status in HML and steroid
plasma levels of aldosterone and its precursors as well as cortisol through
radioimmunoassay. RESULTS: 15 women developed PIH, three of which developed PE.
Neither in the density of MR nor in the affinity the women that developed PIH
showed any difference from healthy women. Steroid plasma levels were identical as
well. CONCLUSION: We conclude that a reduction of mineralocorticoid receptors
does not precede PIH within the peripheral blood. But still one can assume that
the RAAS may be involved in the pathogenesis of PIH, possibly on a local level
within the placenta or as a secondary change, initiated by still unknown factors.
PMID- 10666871
TI - [The autonomic nervous system and pre-eclampsia].
AB - Alterations in the autonomic cardiovascular control have been implicated to play
an important etiologic role in preeclampsia. Earlier assessments of sympathetic
nervous system activity by measurements of urinary and plasma levels of
catecholamines showed contradictory results, due to serious methodological
problems. The microneurographic technique enables the assessment of sympathetic
outflow to the vascular bed of skeletal muscles. By the use of this technique it
has been shown that preeclampsia represents a state of sympathetic overactivity
as compared to healthy pregnant women. Other studies have shown that exogenous
stimulation of the celiac ganglion causes a HELLP-syndrome-like disease in
pregnant rats and that preeclamptic human plasma increases norepinephrine release
in isolated sympathetic neurons of chicken embryos. These data suggest that the
autonomic nervous system may play a fundamental role in the etiology of
preeclampsia.
PMID- 10666872
TI - [Hypertensive illnesses in pregnancy: when is ambulatory management possible,
when is hospitalization indicated?].
AB - Hypertensive disorders complicating pregnancy are the most common medical
complications of pregnancy and are a major cause of maternal and perinatal
morbidity and mortality. Thorough ambulatory obstetric care is likely to achieve
a risk reduction. The main topics of ambulatory obstetric care are early
identification of typical signs of preeclampsia, detection of uteroplacental
insufficiency, and their consequences, detailed information of the patient, and
early admission to a specialised obstetric care unit or perinatal center. Early
diagnosis, close medical supervision, and timely delivery are the keys of the
treatment of preeclampsia.
PMID- 10666873
TI - [Doppler ultrasound findings in therapy with urapidil].
AB - OBJECTIVE: In a prospective study we investigated, whether changes in fetal or
maternal circulation can be found by Doppler sonography under therapy with
urapidil. PATIENTS AND METHODS: We investigated in 11 patients with severe
pregnancy-induced hypertension (PIH) or superimposed preeclampsia in the third
trimester. Doppler flow results of maternal and fetal vessels before and during
therapy with urapidil. Hemodynamic parameters, like maternal blood pressure, and
heart rate as well as other clinical parameters were assessed. RESULTS: Whereas
the antihypertensive effects in the systolic and diastolic blood pressure were
significant, we couldn't find changes in the resistance indices of fetal
circulation. In contrast we found a decrease in the resistance indices in
maternal vessels after an average of six days of urapidil therapy. These changes
were significant in the uterine artery on the side of placental insertion.
CONCLUSIONS: Because of only few side effects and a safe lowering of blood
pressure, therapy with urapidil seems preferable to other well known drugs.
Although Doppler flow velocimetry of uteroplacental vessels has no diagnostic
benefit in monitoring PIH, the findings with this method under prolonged
antihypertensive therapy are a chance for a better understanding of hemodynamic
changes. The decrease in the resistance indices is another argument for the use
of urapidil.
PMID- 10666874
TI - [Early detection of pre-eclampsia within the scope of prenatal care].
AB - Pregnancy-induced hypertension and preeclampsia account for about 25% of
perinatal morbidity and mortality and are a leading cause of maternal death in
developed countries. Consequently, early diagnosis of the disease seems very
important. Numerous clinical and biochemical methods have been described and
tested for the prediction of preeclampsia. The results of these studies are
critically described here. In summary, no test presently available serve as a
reliable early marker of developing preeclampsia. However, vaginal
Dopplerultrasound may allow prediction as early as the 12th to 16th week of
gestation. Moreover, methods detecting underlying mechanisms of the disease such
as endothelial dysfunction and platelet activation, are being developed and might
provide improved early identification of pregnant women at high risk.
PMID- 10666875
TI - [The role of antiphospholipid antibodies in patients with pre-eclampsia].
PMID- 10666876
TI - [Pre-eclampsia and anesthesia].
AB - The management of anaesthesia in patients suffering preeclampsia has to be
selected individually. There is a high rate of caesarean sections in patients
with preeclampsia. Intubation anaesthesia or regional anaesthesia are commonly
used methods and can be considered comparable and equally useful. In our opinion,
the application of regional anaesthesia should be preferred, if the initial
criteria, such as normal neurologic status and blood coagulation, are fulfilled.
We believe in a considerable reduction of vital risks when using regional
anaesthesia. Our aim was to figure out the risk-factors of preeclampsia and
preterm maturity regarding anaesthesia management. Preeclampsia is a severe
illness in pregnancy with a frequency of 5-10%. In 1997, we experienced 73
patients with praeeclampsia according to the definition of ISSPH. Mode of
delivery was conventional in 10 patients, 2 patients had a vacuum extraction and
61 patients needed a caesarean section. The rate of epidural anesthesia for
delivery was 51%. We used epidural anaesthesia in 6 spontaneous deliveries, in 2
vacuum extractions and in 30 caesarean sections. There were no problems with
epidural anaesthesia and the outcome of mother and child was also considered to
be excellent. We suggest to use regional anesthesia techniques whenever possible.
PMID- 10666877
TI - [Current aspects of antihypertensive therapy in pregnant patients with pre
eclampsia].
AB - Preeclampsia is a disease which occurs in Europe in about 6-8%, in the USA in
about 7-10% and in Africa in about 18% of all pregnancies. A causal treatment of
preeclampsia is, with the exception of delivery, not possible up to now. Since a
prematurely delivery of the newborn has to be avoided because of the risks caused
by immaturity of lungs, treatment and care of pregnant women having preeclampsia
or any other kind of hypertensive diseases is restricted to the following
approaches: antihypertensive treatment, volume expansion, and eclampsia
prophylaxis with magnesium sulfate. Object of this treatment is to avoid
complications on the mother's side caused by the disease and to postpone
delivery, as far as possible from the child's side, in order to reduce the
consequences of premature birth. During antihypertensive treatment of patients
with serious hypertension, i.e. with diastolic blood pressure of 110 x mm Hg and
higher, dihydralazine is in clinical use since 40 years, although many patients
suffer from side-effects of dihydralazine such as distinctive tachycardia,
headaches, fluid retention and nausea. With urapidil a well controllable
antihypertensive is available, which prevents the effect of catecholamines at the
vascular wall by a postsynaptic alpha-1 receptor blockade. Previous studies
related to the application of urapidil in the treatment of hypertension during
pregnancy certify the good controllability of urapidil following intravenous
application as well as minor side-effects after start of treatment.
PMID- 10666878
TI - [Epidemiology, risk factors and predictors of pre-eclampsia].
PMID- 10666879
TI - [Psychiatry in XXI century].
PMID- 10666880
TI - [Cerebral strokes at young age].
AB - 791 patients aged 15-44 years with different forms of cerebral stroke that
accounted for 9.4% from all the patients hospitalized because of stroke were
treated. Ischemic stroke (IS) was diagnosed in 477 patients (60.3%), hemorrhagic
stroke (HS) in 293 patients (37.3%), thromboses of the sinuses and veins of the
brain in 19 patients (2.4%). IS to HS was 1.6:1; cerebral strokes were observed
in men twice as frequently as in women. The main causes of HS (180 men, 115
women) were anomalies of cerebral vessels and arterial hypertension.
Intracerebral and subarachnoidal hemorrhage occured with the same frequency. 38%
of the patients died. The main causes of IS in 477 patients (285 men, 192 women)
were arterial hypertension, rheumatism and atherosclerosis of cerebral and
precerebral arteries. Embolic strokes occurred 4,5 times more frequently in
women, than in men. 6.7% of the patients died. Among the patients with disorders
of venous cerebral circulation (13 women, 6 men) 2 women with thrombosis of upper
longitidinal sinus died. According to authors' data pregnancy and delivery are a
significant risk factor for development of all forms of cerebral stroke.
PMID- 10666881
TI - [Dreams and psychologic defence in children and juveniles with neurotic
disorders].
AB - The examination of 78 patients at different stages of neurotic disorders and 25
healthy individuals (10-17 years old) has shown that the dynamics of dreams at
compensatory stage was directed to their intensification, affective and cognitive
activation and to reduction of dreams' activity during decompensation of neurotic
disorders. This may indicate their role in psychologic defence. In neurotic
patients peculiarity of the reaction to stress was the presence of some latent
period after stress, that preceded the very reaction of dream to stress, its
longer duration than in healthy individuals and its qualitative peculiarity. That
may reflect complexity of adaptation to stress influence in neurotic patients.
PMID- 10666882
TI - [Clinical features of ischemic heart disease and modes of subjective perception
of illness].
AB - The sample included 91 inpatients with different clinical forms of ischemic heart
disease (IHD) and modes of subjective perception of illness (subjective meaning
of illness). Prichard's Reaction to Illness Questionnaire, Hospital Anxiety and
Depressive Scale, Rotter's Internal-External Control Scale and Illness Locus of
Control Scale (Bevz I.A.,1998) were used on day 14 after admission for
qualification of the patient's subjective perception of illness. The following
clinical predictors of hypernosognia (inadequately high subjective significance
of illness) were revealed: 1) the onset of IHD in midlife (<65 years) with its
subsequent fast progression including high incidence of recurrent coronary events
and/or congestive heart failure, 2) "typical" and protracted angina pectoris, 3)
cardiac arrhythmias accompanying persistent high heart rate (sinus tachycardia,
chronic atrial fibrillation, frequent extrasystoles) and defying any self-care,
and 4) severe heart failure. On the other hand clinical predictors of
hyponosognosia (inadequately low subjective significance of illness) included 1)
the onset of IHD in elderly individuals (>65 years) and its subsequent slow
progression without recurrent coronary events and/or congestive heart failure, 2)
the socalled "anginal syndrome" (lack of angina's coupling with psychical
exertion, atypical pain location, inconstant efficiency of nitroglycerin) and
silent myocardial ischemia, 3) the paroxysmal cardiac arrhythmias (infrequent
extrasystoles, paroxysmal atrial fibrillation, supraventricular tachyarrhythmias)
with normal or slow heart rate between the paroxysms and high efficiency of self
care, and 4) mild to moderate heart failure. The findings are discussed in terms
of prediction of specific modes of subjective perception of illness and its
practical implications for correction of patient's attitude to his/her disease,
correction of non-compliance, optimization of therapeutical alliance and use of
heart care resources.
PMID- 10666883
TI - [Therapy of autonomic disorders by xanax (alprazolam)].
AB - The paper presents an open noncomparative investigation of 36 patients with
different manifestations of the syndrome of autonomic dystonia. 20 patients
(group 1) had permanent autonomic disorder in context of generalyzed anxious
disorders, 16 patients (group 2) had panic attacks. The examination was performed
before and 4 weeks after monotherapy with xanax (1.5-2.5 mg/day). Clinical
neurologic study estimated both presence and a degree of manifestations of the
syndrome of autonomic dysfunction, hyperventilatory syndrome and sleep disorders.
Psychologic investigation included estimation of anxiety according to Spilberg's
test, depression according to Beck's scale; SCL Scale was also used. Algesic
syndrome was estimated by complex algesic questionnaire. Neurophysiologic study
determined a contingent negative deviation and nociceptive flexory reflex. A
positive therapeutic activity of xanax was established. The highest therapeutic
effect was achieved in group 1 (83%) using lower doses (1.5 mg/day). In group 2
higher doses were needed (2.5 mg/day). In this case the effect was achieved in
83% of the cases, but full absence of panic attacks was observed only in 25% of
the patients. Predictors of the drug's efficiency appeared to be short duration
of the disease, slight manifestation of depression and absence of the algesic
syndrome.
PMID- 10666884
TI - [24-h ambulatory monitoring of cardiovascular indices in patients with panic
disorders].
AB - 24-h monitoring of arterial pressure (AD) and heart rate (HR) was twice performed
in 14 patients with panic attacks (in exacerbation and after a course of
fluoxetine for 6 weeks). Panic attacks were followed by objective increase of
both AD and HR in only 1/3 of the cases and by objective HR increase in 60% of
the patients. Although patients with panic attacks were normothymics,
hypertensive reactions can arise in them, during sleep for the most part.
Alteration of HR variability in sleep-awakening cycle was the most paradoxical
(excess HR variability in awakening state and decreased change during a sleep).
These alterations of HR variability persisted after control of panic attacks with
fluoxetine. This allows to consider HR variability as a factor which reflects
predispositional peculiarities of autonomic system functioning in patients with
panic disorders.
PMID- 10666885
TI - [Neurophysiologic mechanisms of the disorders in recognition of emotions in
endogenic depression].
AB - In 46 male patients with endogenic depressions of different nosology (22 patients
with affective disorder, 24 with juvenile slow-progredient schizophrenia) and 22
healthy individuals (a control group) visual evoked potentials (EPs) were
registered during recognition of emotionally positive, negative or neutral facial
expression. It was found that deficient recognition of emotions in depressions
was determined by alteration of different stages of information analysis. In
inferio-temporal and occipetal cortical areas the Eps revealed delayed primary
analisis of visual information and reduction of components responsible for
classification stage and decision making. In anteriocentral cortical areas only
late stages of analysis were altered, and they were depending on nosology of
depressive sindrom. Dynamics of topographic maps revealed disturbance of analysis
in the right hemisphere in patients with affective disorders and in left
hemisphere in schisophrenics. In both groups of patients deficit of
interhemispheric transfere was found.
PMID- 10666886
TI - [Sporadic amyotrophic lateral sclerosis associated with Asp90Ala CuZn-superoxide
dismutase mutations in Russia].
AB - 16 blood samples from Russian patients (Moscow) with idiopathic motor neuron
disease were analysed for mutations in the CuZn-superoxide dismutase gene. Two
patients (12.5%) with amyotrophic lateral sclerosis (ALS) were found to have a
disease related mutation. One patient appears to have autosomal recessive adult
onset ALS associated with homozygosity for Asp90Ala and presents the
characteristic phenotype of very slowly ascending paresis with both lower and
upper motor neuron signs. The other patient heterozygous for Asp90Ala presents
ALS with lumbar onset and rapid progression. Both of cases are apparently
sporadic.
PMID- 10666887
TI - [The level of middle mass molecules and lipid peroxidation in blood of patients
with different forms of stroke].
AB - To elucidate correlation between processes of lipid peroxidation (LP) and
accumulation of peptides from the group of "middle molecules" (PMM) in blood, we
made investigation of blood of 81 patients with ischemic and hemorrhagic stroke.
Gel-filtration column chromatography for PMM separation was performed. Divided
fractions were registered with UV-monitor at wave length equal to 254 nm. The
character of both spontaneous and Fe(2+)-induced chemiluminescence, the level of
malonic dialdehyde (MDA) and conjugated dienes (CD) were estimated. It was
established that the level of LP processes was significantly increased in blood
and erythrocytes of patients with stroke, especially in hemorrhagic form. The
total content of PMM, especially of A and A4 fractions, as well as D and F
fractions was almost twice as much in blood. A correlation was observed between
accumulation of PMM in blood of patients with stroke and PL induction, that may
be the factor of PMM generation. A conclusion was made, that accumulation of some
PMM classes in blood of patients with strokes was related to LP processes, which
were responsible for the severity of the secondary pathochemical alterations in
tissues of the brain. These findings should be considered in elaboration of drug
treatment and estimation of the disease prognosis.
PMID- 10666888
TI - [Peculiarities of polymorphism in gene of serotonin transporter in men from
different ethnic groups with acute alcoholic psychoses].
AB - Analysis of polymorphism in locus of the gene of serotonin transporter (hSERT)
was performed in men of Russian and Tatar nationalities with acute alcoholic
psychoses by polymerase chain reaction. An absence of the differences in the
distribution of the frequences of genotypes and alleles of hSERT gene was
observed between populations examined, that corresponded to such values in
Caucasians. An association was found between the allelic variations with 9 units
of the repetitions of hSERT gene and an early onset of chronic alcoholization and
development of acute alcoholic psychosis. Among the men, who developed acute
alcoholic psychosis at the age over 35 there were significant differences in
distribution of frequences of genotype of hSERT-gene between the populations.
Genetic heterogeneity of such pathology in Russians and Tatars and impact of
hSERT in the development of the disease in Tatars, are suggested.
PMID- 10666889
TI - [Factors of lonely living in old psychiatric patients].
AB - 70 lonely patients 60-83 years old were examined. Loneliness in the disintegrated
first group (54 patients) resulted from the disintegrated family (the patients
were early married). The loneliness in the second group was determined by the
absence of their own family (16 patients). The main factors leading to loneliness
were such diseases as schizophrenia and epilepsy, paranoic disorders of
persecutive character directed to the nearest family, hypochondric depression,
psychopathic-like disturbances, mental defect, personality disorders in premorbid
state. Among social-psychologic factors the following ones had a significance:
underestimation of the mental disorders in patients by their relatives, conflicts
in the family, the patient's negative orientation to marriage, their deep
emotional interrelation with the parents in young and mature age, alcoholism of
married couple and special psychopathic features of the relatives. The events
relating with the old age (loss of elderly couple), separation with adult
children and parents, bad domestic living conditions were of less significance.
PMID- 10666890
TI - [Classification of the dementias].
PMID- 10666891
TI - [Diagnosis of celiac disease].
PMID- 10666892
TI - [Rational management of acute community-acquired pneumonia].
PMID- 10666893
TI - [Transgenic food].
PMID- 10666894
TI - [The pediatrician and children from immigrant families].
PMID- 10666895
TI - [Recommendations for the dietary treatment of phenylketonuria].
PMID- 10666896
TI - [Body fat mass in boys and male adolescents].
AB - OBJECTIVE: To describe the proportion of body fat mass, quantified from the
measurement of 4 skinfold thickness, in a sample of male children of Zaragoza.
METHODS: In 1995, we have studied 701 males aged 6.0 to 14.9 years, from 6
schools of the province of Zaragoza. We have measured: weight, height, and
biceps, triceps, subscapular and suprailiac skinfold thicknesses. Body density
has been calculated from the 4 skinfold measurements, with the formulas of Sarria
et al. Fat mass (%), was calculated with the Weststrate and Deurenberg's
formulas. In each age group, we present mean, standard deviation and 5, 25, 50,
75 and 95th percentiles. RESULTS: We present mean, standard deviation and 5, 25,
50, 75 and 95th percentiles of body fat mass (%), in each age group. Body fat
mass (%) progressively increased until 10.5 years and, after, progressively
decrease at least until 14.5 years. CONCLUSIONS: We present data of body fat mass
(%), calculated from the measurement of 4 skinfold thicknesses, obtained from a
reference population in the province of Zaragoza. These data are useful as more
rationale criteria in the diagnosis of obesity in children and adolescents.
PMID- 10666897
TI - [Lupus anticoagulant in children. Report of 4 cases].
AB - OBJECTIVE: We present four cases of lupus anticoagulant (AL) in children. In
addition, as a result of the lack of literature published on the subject in our
country. We also evaluate the epidemiological, clinical and prognostic
characteristics of AL in children. PATIENTS AND METHODS: The diagnostic criteria
established by the "Subcommittee for the Standardization of Lupus Anticoagulant"
were followed. RESULTS: Over a ten-year period (1988-1998), 46 cases of children
with TTPA prolongation were documented. Nine children showed circulating
anticoagulant, 4 of which were lupus type anticoagulants. The age of the patients
ranged from 4 to 13 and there was a prevalence of males (3/4). Half of the
children had a family history of bleeding dyscrasia and it was these who showed
hemorrhage or thrombotic symptoms. The case that started with ecchymosis and
hemorrhaging showed prothrombin prolongation due to factor II deficit. In 3 of
the 4 children, AL was linked to acute respiratory infections and was transitory.
The other coincided with two thrombotic episodes of the lower extremities in a
healthy child. Positive anticardiolipin antibodies were detected in two patients,
both showing repeated AL episodes, one with thrombosis and the other always
asymptomatic. CONCLUSIONS: Diagnosis of AL in children is difficult and has
probably been underestimated. Although it is usually transitory, it can appear in
repeated episodes. Its early detection is important as it can be linked to both
prothrombin deficit, as well as significant symptoms of hemorrhaging.
PMID- 10666898
TI - [Nutritional status assessment in children entering foster care].
AB - OBJECTIVE: The purpose of this study was to assess the nutritional status of
abused and neglected children in a middle-sized city (Zaragoza, Spain) at the
time of entry into foster care. PATIENTS AND METHODS: A cross-sectional study was
performed over a 7-year period. Using the anthropometric method, the nutritional
status of 684 children (379 boys/305 girls), ranging in age from 1-17 years, was
assessed. Weight, height and body-mass index were formulated (mean and DS) and
compared with normal national reference standards (Z-score). Significant
statistical differences were assessed (Student's unpaired t test). RESULTS:
Below, arranged by age and sex, the significant variances reflecting subnormal
standards are listed. Weight: 1 and 2 year old boys and girls (p < 0.001); 3 and
4 year old girls (p < 0.01); 3, 4, 5 and 6 year old boys and 7, 8 and 10 year old
girls (p < 0.05). Height: 1, 5 and 9 year old boys and 1, 2, 3, 4 and 11 year old
girls (p < 0.001); 2 and 4 year old boys and 6 and 10 year old girls (p < 0.01);
3, 6, 10, 15, 16 and 17 year old boys and 8, 9, 11, 12, 13 and 17 year old girls
(p < 0.05). Body-mass index: 1 year old boys (p < 0.001); 6 year old boys (p <
0.01); 1, 2 and 7 year old girls (p < 0.05). CONCLUSIONS: Malnutrition and growth
delay are present in a high rate of children entering foster care. In preschool
children, moderate forms of acute and chronic malnutrition with wasting and
stunting are predominant, identifying with the "failure to thrive syndrome". In
primary and secondary school aged children, mild forms of chronic malnutrition
with growth failure are predominant. When growth and developmental delay is
present in children entering foster care, in the majority of cases, nutritional
and emotional deficiencies are the etiology for this delay. This is consistent
with the concept of "growth and developmental delay of psychosocial deprivation
origin".
PMID- 10666899
TI - [Calcium intake among school children in Badajoz].
AB - BACKGROUND: The intake of calcium has been studied in the diet of adolescents
from a school in Badajoz (Spain) determining their BMI and their living habits
(sport, consumption of tobacco and alcohol). METHODOLOGY: By means of an aleatory
sampling, a sample n was selected = 207 (49.76% males and 50.24 females) with an
average age of 14.14 +/- 2.08 years. They were weighed and measured to calculate
their BMI. A questionnaire was carried out on consumption of products rich in
calcium: milk and dairy produce, vegetables, fruit, chied fruits. The statistical
analysis was carried out by means of Student t and ANOVA. RESULTS: The results
was BMI < 25 (thin or standard) in 86.47%; BMI 25-30 (overweight) in 10.63% and
BMI > 30 (overweight) 2.9%. The consumption of daily calcium was of 1304 +/- 702
g/ppd, higher (p < 0.001) in boys (10.45 +/- 5.51) than in girls (7.82 +/- 3.84).
There is not correlation between BMI and calcium consumption. The boys observe
the NIH recommendations. But girls usually don't. Milk products provide 87% of
the consumed calcium. The boys who practice some sports consume 9.88 +/- 5.23
g/pps, the other ones 7.09 +/- 2.95 g/pps. CONCLUSIONS: 1. The weekly intake of
calcium by surveyed students is 9.13 g/pps, smaller in girls than in boys. 2.
Milk products provide 87% of the consumed calcium. 3. A 10.63% of them is
overweight and a 2.9% is very overweight. 4. A 10.63% usually smokes and a 20.29%
consumes alcohol. 5. A 26.27% doesn't practice any sports and consumes less
calcium (p < 0.001) than the recommended quantity.
PMID- 10666900
TI - [Forearm bone mineral density in healthy children].
AB - OBJECTIVE: In order to establish the normal patterns of forearm bone mineral
density (BMD), BMD in the cortical and trabecular parts of the distal forearm
were studied in a normal pediatric population. PATIENTS AND METHODS: BMD was
measured by dual-energy X-ray absorptiometry (HOLOGIC QDR-1000) in the distal
third forearm of 246 normal children and adolescents (111 boys and 135 girls)
ranging from 2.8 to 20.8 years of age. BMD was correlated by multiple regression
analysis with age, weight, body mass index (BMI), sex and pubertal Tanner stage.
RESULTS: Forearm BMD increased progressively with age, weight, height, BMI and
maturity, with the maximal increase in all forearm bone sites occurring at the
onset of puberty in girls and boys. A statistically significant correlation was
found between forearm BMD and all of these variables (r = 0.65 to 0.92). Mean BMD
was higher in boys than in girls in cortical, trabecular and cortical-trabecular
sites of the distal forearm. Maximal differences in BMD between boys and girls
occurred at 17-18 years of age, especially the trabecular-dominated (ultradistal)
part of the distal forearm (0.446 vs 0.384 g/cm2). CONCLUSIONS: Forearm BMD
studies permit information of both cortical and trabecular bone mineralization to
be obtained at the same time. This study reports normative data for forearm BMD
in a healthy pediatric population. The values obtained may be used as a reference
of normality when evaluating bone density in situations where skeletal
mineralization may be compromised.
PMID- 10666901
TI - [Infectious mononucleosis: study on hospitalized children].
AB - OBJECTIVES: To analyze the patients diagnosed of infectious mononucleosis (IM) in
our institution, in order to study the symptoms and clinical evolution. MATERIAL
AND METHOD: We retrospectively analyse 37 hospitalized children aged between 3
months and 14 years. Diagnosed of IM by production of immunoglobulin M (IgM) to
viral capsid antigen (VCA). RESULT: In our series of 37 children, 14 were less
than 4 years old. Among clinical data, lymphadenopathy (86%), fever (81%) and
pharyngotonsillitis (70%) were the more striking. We found jaundice only in three
of the older children. Upper airways obstruction was common, and specially severe
in young children. Three patients developed pneumonia during the disease course.
Only ten patients produced heterophile antibodies. Two children showed dual
antibody rises to Epstein-Barr virus and cytomegalovirus. Corticotherapy was used
in 7 children. The complications are presented in 68% of patients. CONCLUSIONS:
Clinical aspects of IM were similar to those in the young adult, and
complications occur more frequently. We found lack of heterophile antibodies,
more frequent in youngest.
PMID- 10666902
TI - [Apert syndrome: clinico-epidemiological analysis of a series of consecutive
cases in Spain].
AB - OBJECTIVE: Apert syndrome is one of the five craniosynostosis syndromes caused by
allelic mutations of the fibroblast growth-factor receptor 2 (FGFR2). It is
characterized by symmetrical cutaneous and bony syndactyly of the hands and feet
and a variety of pleiotrophic features of the skeleton, central nervous system,
skin and internal organs. PATIENTS AND METHODS: We show the clinical and
epidemiological characteristics of the 17 cases of Apert syndrome identified in a
consecutive series of 26,956 malformed liveborn infants detected among 1,502,639
livebirths surveyed by the Spanish Collaborative Study of Congenital
Malformations (CEMC) between April 1976 and March 1998. RESULTS AND CONCLUSIONS:
The estimated frequency of Apert syndrome in Spain is 0.11 per 10,000 liveborn
infants. All of the cases were sporadic and were associated with an increased
paternal age. The clinical manifestations of our cases are concordant with the
variable expression of the syndrome, with the cardinal features of acrocephaly
secondary to craniosynostosis and syndactyly of hands and feet present in all
cases, and other anomalies, including cardiovascular (23.5%), cleft palate
(23.5%), urinary (5.9%) and central nervous system (5.9%), in some of the
patients.
PMID- 10666903
TI - [Extracorporeal membrane oxygenation, ECMO. Experience with the first 22 cases].
AB - OBJECTIVE: Extracorporal membrane oxygenation (ECMO) is an alternative to cases
of respiratory or cardiopulmonary insufficiency when conventional therapy has
failed. We present the first 22 patients treated with ECMO at the neonatology
unit of the "Gregorio Maranon" Hospital. PATIENTS AND METHODS: From October 1997
until September 1999, 22 patients were treated with ECMO. In 8 of them ECMO was
necessary because of respiratory insufficiency without response to conventional
treatment (r-ECMO) and a veno-venous tidal flow system was used. In 14 patients,
cardiac ECMO was necessary in the veno-arterial modality because of ventricular
failure after extracorporal circulatory assistance during cardiovascular surgery.
RESULTS: The 8 patients of the respiratory ECMO group had a mean previous
oxygenation index of 89 +/- 36.6 (50-150). The mean duration of ECMO was 7.8 +/-
6.5 (1-16) days and the age at the beginning of ECMO ranged between 1 and 151
days. The most frequent indications in this group were congenital diaphragmatic
hernia in three cases, meconium aspiration syndrome in 2 cases and 1 case each of
septic shock, idiopathic pulmonary hypertension and air leak. The cannula was
removed in 5/8 patients due to recovery and 5/8 survived. The 14 patients of the
cardiac ECMO group needed veno-arterial ECMO because of severe ventricular
failure. Eight out of fourteen were decannulated after improvement. In 5/14 there
was multiorgan failure or bad neurological prognosis resulting in death while on
ECMO. In 1 out of 14 patients removal of the cannula was impossible because of
cardiac insufficiency. The mean age at the beginning of ECMO was 54 (3-178) days.
The mean weight at ECMO was 3209 +/- 739 (2700-5000) gr and the mean duration of
ECMO was 6 (1-15) days. CONCLUSIONS: ECMO is an effective treatment in rescuing
critical patients when conventional treatment fails. Meconium aspiration syndrome
is the pathology with the best prognosis on ECMO. Cardiac ECMO represents a
complex group of patients in which ECMO is the only treatment and which may
result in recovery in 40% of the patients.
PMID- 10666904
TI - [Eosinophilic meningitis of unknown etiology. Infrequent occurrence in
pediatrics].
PMID- 10666905
TI - [Type I neurofibromatosis associated with internal carotid artery hypoplasia].
PMID- 10666906
TI - [Generalized hypopituitarism in absence of hypophyseal stalk with ectopic
neurohypophysis in a tall-for-age girl].
PMID- 10666907
TI - [Neonatal macrocephaly caused by multiple cerebral arteriovenous fistula treated
with embolization techniques].
PMID- 10666908
TI - [Neurotuberculosis: multiple tuberculomas in a 6-year-old child].
PMID- 10666909
TI - [Anemia in a girl from the Antilles].
PMID- 10666910
TI - [Recommendations for basic, advanced, and neonatal cardiopulmonary resuscitation.
IV. Resuscitation in newborns. Spanish Group for Pediatric and Neonatal CPR].
PMID- 10666911
TI - [Transient benign persistent hyperphosphatasemia in children].
PMID- 10666912
TI - [Value of the dissemination of the Mulford Library catalog in pediatrics].
PMID- 10666913
TI - [Transverse HIV myelitis in a child with AIDS].
PMID- 10666914
TI - [Cholestasis associated with parenteral nutrition in a critically ill child].
PMID- 10666915
TI - [Regulation of anaphylactic responses by Fc receptors].
PMID- 10666916
TI - [Nasal allergy--its immunological view].
PMID- 10666917
TI - [Skin management of itching in atopic dermatitis].
PMID- 10666918
TI - [Keeping dogs indoor aggravates infantile atopic dermatitis].
AB - We had a two-month-old girl with severe dermatitis since birth. Her serum RAST to
HD, Df and Dp were 1.06, 0.03 and 0.01 Ua/ml respectively. A Yorkshire terrier
were kept at her mother's parents' home where the patient had lived for a month
since birth. Her eczema, which became markedly aggravated whenever she visited
there, improved after the elimination of the dog. We investigated the
relationship between keeping dogs and infantile atopic dermatitis. We studied 368
patients under the age of two years (211 boys and 157 girls). Skin symptoms were
graded globally mild, moderate or severe. Total serum IgE and specific antibody
titer to dog dander were measured. We asked them whether they kept dogs and
specifically, where they kept dogs, outdoor, indoor, in their own house, or in
their grandparents' house. 197 patients had no contact with dogs, 90 patients
kept dogs outdoor and 81 patients did indoor. The positive rate of RAST (> or =
0.7 Ua/ml) to dog dander was 6.1%, 17.8% and 46.9% respectively in these three
groups. There were strong statistical differences between three groups. On the
other hand, among the 81 patients who kept indoor, the RAST positive rates were
almost same regarding where the dogs were kept, in their own house or their
grandparents' house. Interestingly this difference happens only with patients
under the age of 3 months. Patients older than 4 months showed no significant
differences in the positive RAST rates, whether they kept dogs indoor or outdoor.
This suggests the sensitization occurs before the age of 3 months. Speaking of
symptoms, patients who kept dogs indoor showed significantly more severe symptoms
than patients who had no contact with dogs and patients who kept dogs outdoor.
There was no significant difference between the symptoms of patients who had no
contact with dogs and those of patients who kept dogs outdoor. This implies the
patient's symptom will improve only by moving the dog out of the house.
PMID- 10666919
TI - [Clinical significance of allergen specific immunotherapy in adult house-dust
mite-sensitive bronchial asthma: impact on disease severity and medical cost].
AB - The objective of this study was to evaluate the clinical significance of allergen
specific immunotherapy in house-dust-mite-sensitive adult bronchial asthma. Fifty
patients treated with rush immunotherapy using house dust antigen were examined.
The disease severity was compared between before and a year after the maintenance
immunotherapy: reduction in the severity was observed in 27 patients (54.0%)
following the treatment. The response rate was greater in the patients with step
3 (moderate, persistent) or step 4 (severe, persistent), disease period less than
10 years, or reversible airway obstruction. Patients who showed favorable
clinical response also demonstrated the reduction in medical costs. These results
suggest that allergen immunotherapy reduces the disease severity and medical cost
in a certain population of adult atopic asthma.
PMID- 10666920
TI - [A mechanism for the anti-inflammatory effect of nedocromil; inhibition of both
adhesion molecule expression on eosinophils and endothelial cells, and eosinophil
chemotactic activities].
AB - The accumulation of eosinophils in the airway is one of the characteristics seen
in patients with bronchial asthma. One of the newly developed anti-asthma drugs
(controller), nedocromil sodium (nedocromil) is known to suppress the influx of
eosinophils into allergic lesions. However, little is known about this mechanism.
Therefore, in this report we investigated the effects of nedocromil on Mac-1
expression on PAF-stimulated eosinophils, and adhesion molecule expression on
endothelial cells stimulated by either IL-1 beta or IL-4. We also investigated
the eosinophil chemotaxis. A significant suppression of the Mac-1 expression on
PAF-induced eosinophils was observed at both concentrations of 10(-5) and 10(-7)
M of nedocromil. The expression of adhesion molecules, particularly ICAM-1 and E
selectin, on IL-1 beta-stimulated human umbilical vascular endothelial cells
(HUVEC) was significantly suppressed at these concentrations, whereas the VCAM-1
expression was not changed. No significant suppression of VCAM-1 expression on IL
4-stimulated HUVEC was observed, although there was a tendency of suppression at
these concentrations. On the other hand, the expression of the E-selectin
molecule was significantly suppressed by nedocromil even under resting (non
stimulated) condition. PAF-induced eosinophil chemotactic activities were also
suppressed at these concentrations in a dose-dependent manner. These results
suggested that nedocromil suppressed the influx of eosinophils to inflammatory
lesions by inhibiting not only the expression of the Mac-1 on eosinophils and of
E-selectin and ICAM-1 molecules on HUVEC, but also the eosinophil chemotactic
activities.
PMID- 10666921
TI - [Effect of rush immunotherapy (RIT) on Hymenoptera allergy].
AB - In our country approximately forty people die every year from anaphylaxis caused
by hymenoptera stings. Between 1988 and 1996, 48 patients, who had experienced a
systemic reaction to hymenoptera sting and were proved to have specific IgE
antibodies to wasp, yellow or both (RAST score > or = 2), received rush
immunotherapy (RIT) using venom extracts in our hospital. Fifteen patients had re
sting after RIT. Fourteen out of the 15 patients showed only local reaction to
the hymenoptera re-sting and one patient had mild generalized symptoms. Although
one patient showed mild generalized uriticaria during RIT, no adverse reaction
occurred during and after RIT in the other subjects. Follow-up studies on the
titers of serum total IgE antibodies and hymenoptera specific IgE and IgG4
antibodies revealed that total and specific IgE antibodies transiently increased
one month after RIT and returned to their baseline values by 6 months after RIT,
while specific IgG4 antibodies continued to gradually increase up to al least 3
years after RIT. These results demonstrates that RIT is effective in prevention
of a systemic reaction to hymenoptera re-sting and an increase in the titer of
hymenoptera specific IgG4 antibodies may at least partly explain the efficacy of
RIT.
PMID- 10666922
TI - [Assumption of the area supplying Okayama Prefecture with Cryptomeria japonica
and Cupressaceae airborne pollen, and of their scattering routes].
AB - It is very important to predict and disseminate information about the total
pollen counts of both Cryptomeria japonica and Cupressaceae for patients with
pollinosis. In Okayama Prefecture, we have reported that the pollen counts of
both Cryptomeria japonica and Cupressaceae are influenced by the meteorological
conditions in the previous July. We predicted the area supplying Okayama
Prefecture with Cryptomeria japonica and Cupressaceae pollen, and also the route
of airborne pollen from the meteorological conditions and a topographical map of
Okayama and four neighboring prefectures. It was found that Cryptomeria japonica
and Cupressaceae pollen counts at the four observation sites correlated very well
with the meteorological conditions at Tsuyama weather station in Okayama
prefecture. Therefore, we considered that the areas supplying Okayama prefecture
with Cryptomeria japonica and Cupressaceae pollen were the central northern areas
including Tsuyama, 85.7% of whose plantation areas contained Cryptomeria japonica
and Chamaecyparis obtusa, and that their pollen was carried along the routes of
three major rivers, R. Takahashi, R. Asahi and R. Yoshii.
PMID- 10666923
TI - [Effectiveness of preventive activities].
PMID- 10666924
TI - [PAPPS effectiveness study (1998) and preliminary results of the PAPPS evaluation
(1999)].
PMID- 10666925
TI - [Prevention and health promotion in childhood and adolescence. Group for
Prevention in Childhood and Adolescence of the PAPPS].
PMID- 10666926
TI - [Preventive cardiovascular recommendations: practical applications of
cardiovascular risk. Group for Cardiovascular Prevention of the PAPPS].
PMID- 10666927
TI - [Cancer prevention. Group for Cancer Prevention of the PAPPS. Update 1999].
PMID- 10666928
TI - [Prevention of transmissible diseases. Work Group for Transmissible Diseases of
the PAPPS].
PMID- 10666929
TI - [Recommendations on life style. Work Group for Health Education and
Cardiopulmonary Prevention].
PMID- 10666930
TI - [Prevention of mental health disorders in primary health care. Group for
Prevention in Mental Health of the PAPPS].
PMID- 10666931
TI - [Cutaneous asthenia (Ehlers-Danlos syndrome) in a domestic rabbit].
AB - Cutaneous asthenia is a connective tissue disease primarily of dogs and cats,
resembling Ehlers-Danlos syndrome in man. This is a description of the disorder
in a rabbit. The one-year-old female animal was presented because of two large
gaping wounds of the skin. Clinical examination revealed a hyperextensible, thin,
and fragile skin. The degree of skin extensibility was evaluated by means of a
skin extensibility index (SEI: 19.2%) and compared with those of 4 healthy
rabbits (SEI: 8.3%-14.3%). Clinical diagnosis was confirmed by histopathological
examination of a skin biopsy revealing reduced packing density of collagen
fibers. In addition a decreased number of hair follicles was observed. No
conclusion could be drawn regarding the etiology, but existing literature
strongly suggests a genetic cause (mostly autosomal dominant inheritance) in
humans as well as in animals.
PMID- 10666932
TI - [Fluctuations of urea, cholesterol and triglyceride concentrations in plasma of
clinically health piglets during the first four weeks of life].
AB - The present study was designed to investigate fluctuations of plasma
concentrations in urea, cholesterol and triglyceride in healthy piglets (Landrace
x Pietrain) during the first four weeks of life. Blood samples were taken by
venipuncture in 240 piglets thirty minutes after birth, after 6, 24, 48, 168,
336, 504 and 672 hours. Cholesterol and triglyceride concentrations exhibited
minimum values after delivery and rose up to the 48th hour of life, what can be
explained by colostrum intake. Although an increase of urea after birth was
determined, but some of the following measured concentrations were under the
initial value. The three parameters showed a significant dependency on the age (p
< 0.001). After 6 hours there was a correlation of cholesterol concentration and
sex (p = 0.001) and triglyceride concentrations have been correlated to body
temperature after 24 and 48 hours (p = 0.009; p = 0.004). Before colostrum intake
urea concentration has been associated to body temperature (0.001). The
physiological significance of the observed fluctuations for adaptation from an
intrauterine to an extrauterine life is discussed.
PMID- 10666933
TI - [Quality of development and adaptation reactions of dairy calves at specific age
periods in early life. Effect of rearing variations on proteins and minerals and
on metabolic variables of blood].
AB - Calves from the dairy herd of the institute reared in groups with changing (Gw, N
16, m 9, w 7) and constant composition (Gk, N 16, m 9, w 7) since the first day
of life and single box reared calves (E, N 11, m 7, w 4) were tested at 15, 30,
60 and 90 days of age. Venous blood samples were analysed for total protein,
albumin, creatinine, blood urea, glucose, Ca, Mg, P and iron. At 15 days between
group differences of mean values existed for total protein, albumin, blood urea,
creatinine and at 30 days for rectal temperature, albumin, blood urea, Ca, P and
Fe, at 60 days for blood urea, glucose, Ca, Mg, P and at 90 days for total
protein, albumin, creatinine, glucose, Mg and P. Interactions between group and
gender could not be demonstrated. Significant changes of variables with age were
most frequent in calves of group Gk, and more frequent with creatinine, blood
urea, Fe and glucose. Creatinine concentration diminished permanently with age of
the animals, that one of total protein and albumin increased moderately. Blood
urea was higher at 90 days, and serum iron at 60 and 90 days than before. Blood
glucose concentration at 90 days was lower in calves of group Gw and Gk comparing
group E. Significant group differences appeared at 15 days (total protein,
albumin, blood urea, creatinine) and remained till 60 days (blood urea) and 90
days (total protein, albumin) or became stronger at 90 days (creatinine). Total
protein, albumin and blood urea were higher in group E than in group Gk and Gw
calves. Group Gw calves had smallest glucose concentrations at 60 and 90 days.
Significant between groups differences for Ca, Mg, P existed for all sampling
points, those for serum iron at 30 days only. Greater Ca and Mg values were found
in group Gk and group E calves, greater P concentrations up to 60 days of age in
group E calves. P concentrations changed differently in group Gk and group Gw
calves with age. Creatinine showed moderately high between sampling point
correlations. Changes of variables in calves between age points in relation to
the starting situation at 15 days of age showed significant correlations in many
cases meaning that there were directed individual and time specific adaptation
processes.
PMID- 10666934
TI - Efficacy of a combination of amoxicillin and clavulanic acid in the treatment of
pneumonia of pigs.
AB - Amoksiklav was used in the therapy of mixed respiratory tract infections in
weaned pigs under field conditions. Positive effects of therapy with Amoxicillin
and Clavulanic acid were observed in the majority of treated pigs. The production
losses due to pneumonia in pigs treated with this combination were lower than
among control pigs treated with Oxytetracycline, also a significantly lower ratio
of death was observed among experimental weaners in comparison to the controls.
Thirty days after the end of the therapy it was found that the body weight gain
(b. w. g) of the experimental animals was on average 800 g higher after this
period and the experimental piglets grew daily in average 20 g more than the
controls. Experimental pigs were slaughtered 3 days earlier than the controls and
the average weight gain at slaughter was highest by 1.1 kg in this group. Average
daily b. w. g. of experimental pigs during the period from birth to slaughter was
13 g higher in comparison to the controls.
PMID- 10666935
TI - [Orienting endotoxin measurement in the atmosphere].
AB - Airborne endotoxins are supposed to influence the respiratory health of animal
and man in animal housings as well as at certain work places in agriculture.
Little is known about the usual concentrations of endotoxin in the outdoor
atmosphere. Therefore in a field study 30 air samples were taken, 22 samples in a
rural region, and 8 in a more residential and industrial area. The samples were
taken by impingement and filtration. The analysis was carried out by means of the
chromogen-kinetic limulus amoebocyte lysate test (LAL-Test). The median
concentration of all samples was 0.36 ng/m3. The highest median concentration of
0.49 ng/m3 was found in summer with a maximum value of 1.80 ng/m3 indicating
large variations. In the other seasons the median concentrations (ng/m3) were
distinctly lower (spring: 0.30, n = 11; autumn: 0.26, n = 5; winter: 0.19, n =
3). No significant differences were observed between farming and residential
areas at this low concentration level. The concentrations of endotoxin found in
this study were far below all threshold limits which are presently discussed for
work places.
PMID- 10666936
TI - Simultaneous transmission of Trypanosoma mukasai, Babesiosoma mariae and Cyrilia
nili to fish by the leech Batracobdelloides tricarinata.
AB - Trypanosoma mukasai (HOARE, 1932), Babesiosoma mariae (HOARE, 1930) and Cyrilia
(= Haemogregarina) nili (WENYON, 1909) were concurrently transmitted from Tilapia
nilotica to Clarias lazera using the leech vector Batracobdelloides tricarinata.
Concurrent transmission was more successful in immature Clarias lazera in which
prepatent periods were shorter and patency longer than in mature fish.
PMID- 10666937
TI - [Possibilities and limits of assisted reproduction].
AB - The term assisted reproductive technologies (ART) describes all treatment
procedures which include more than the natural intercourse to conceive. The most
invasive procedure is intracytoplasmic sperm injection (ICSI), which was
introduced in 1993. By ICSI the successful treatment of couples with severe male
factor infertility, even in cases of azoospermia, became possible. In cases where
only immature forms of spermatogenesis are present in the testicular tissue,
pregnancies could also be achieved. The limiting factor with greatest influence
on the success rate of ART procedures is the female's age. In this context the
treatment of postmenopausal women by oocyte donation, as well as ooplasma
donation to overcome the negative influence of the female's age on oocyte quality
are extreme examples of ethically questionable ART procedures. Until now several
100,000 children worldwide have been born subsequent to ART and especially in
vitro fertilisation. No increase in the malformation rate neither after IVF nor
after IVF/ICSI have been reported so far. However, because of the lack of
prospective controlled studies using standardised evaluation procedures and
having enough statistical power to prove the security of ICSI for the newborn
children, the German statutory health insurance bodies have ceased to pay ICSI
costs as of July 1999. The data on the success of ICSI, the known data on the
newborn and developing children and the decisions of the medical services of the
German statutory health insurance bodies are presented in discussed in this
paper.
PMID- 10666938
TI - [Mother-child treatment. Chance for differentiated and specific introduction of
necessary psychological preventative and treatment measures].
AB - Many women are often caught up in multi-layered situations of stress and strain
without having an opportunity to speak about themselves and their difficulties.
Within the setting of a health recovery programme for mothers and their
child(ren), a first step might be possible to raise their awareness for an
underlying psychological problem. Interventions might focus on symptoms
pertaining to the psychological, psychosomatic and psychosocial sphere.
Experience shows that the clients mostly present with problems specific to women.
Describing various interventions, the author discusses psychological support
measures that might be provided for women in the course of a health recovery
programme.
PMID- 10666939
TI - [Drug prescribing in primary health care for diabetic and non-diabetic patients:
effect of therapeutic drug budgeting].
AB - With computerised data on drug prescriptions, which were collected among a sample
of 362 internist, general and medical practitioners throughout Germany, the
effects of the drug budget, based on the German Health Care Structure Reform Act
(GSG), on diabetic patients were analysed. The data of 3053 diabetic patients
(10% random sample) were compared with the same number of nondiabetic patients
for the period of July 1992 to December 1994. The frequency of consultations per
patient increased in both groups during the study period (p < 0.01). Diabetic
patients had more contacts with the physicians than nondiabetic subjects (p <
0.01). The prescriptions and costs among the patients with diabetes decreased in
the first six month of 1993 (-10%/ -16%). In the following time costs increased
and exceeded the values of 1992 by about 13%. The costs per prescription
decreased during the study period about 10%. The data show that costs as well as
prescriptions per consultation between diabetic and nondiabetic patients remained
in the same ratio. The proportion of consultations with > or = 1 prescription
increased in diabetic patients after the GSG. A refusal to prescribe drugs in
primary health care practices among diabetic patients was not observed. There was
also no restriction on prescription drug use among diabetic patients compared
with nondiabetics.
PMID- 10666940
TI - [Ornithosis--studies in correlation with an outbreak].
AB - An outbreak of ornithosis with 8 cases of ornithosis pneumonia and 2 lethal
complications was investigated in workers in a poultry farm and processing plant
and a comparative seroepidemiological study of antigen responses was performed in
3 collectives: No. I: n = 82/87 workers in the processing plant, where the
outbreak occurred; No. II: n = 83 workers in a chicken slaughter-house; No. III:
n = 82 as matched-pair group to collective No. I with the same age and sex, but
without occupational risk. The test systems were: genus specific complement
fixation reaction (CFR), Ipazyme commercial slide kit containing LGV antigen and
a type-specific microimmunofluorescence (MIF) technique with antigens binding C.
psittaci, pneumonia and trachomatis IgA, IgG and IgM. 57/82 (71.9%) workers in
group No. I were chlamydial antibody-positive, whereas only 22/82 of the
population Nr. III--control group (odds ratio 6.2/3.2-12.3 p < or = 0.05). 16/83
(19.3%) of the workers in the chicken slaughterhouse had antibodies against
chlamydia group antigens. 30/82 of the collective No. I had serological evidence
of a recent or current infection with higher antibody titres in CFR and IPAZYME
Test and/or antibody response against IgA and IgM (MIF). 43.3% of the latter
could be serologically detected as specific infections with C. psittaci. 10 of 18
(55%) workers employed in the recent 3 months had serological signs of an acute
infection. There was no association between the point of contact with the poultry
(live hang areas, slaughtery, evisceration, cooling carcasses) and the prevalence
of antibody response. The possible routes of infection, inhalation of dried
excretions or aerosols and via hand-to-mouth contacts are discussed. In specimens
of cloacal swabs and faeces of the ducks chlamydiae could be found although the
animals were asymptomatic. The results of this study demonstrate that in poultry
plants, where ducks and other poultry living in an aqueous habitat are
slaughtered and processed, a high risk of C. psittaci infection (70.2%) and
ornithosis morbidity (25%) with a lethality of 8.3% can exist. Since the
eradication of C. psittaci in poultry does not seem to be possible at the moment,
preventive measures e.g. gloves, masks, information and medical examinations of
the workers must be implemented in those slaughterhouses and plants where C.
psittaci is suspected or common.
PMID- 10666941
TI - [Utilization of dental services--results of an oral hygiene study in Saxony].
AB - The utilisation of dental services is a precondition for professional preventive
measures. The representative oral survey "Bevolkerungsreprasentative Studie zum
zahnarztlich-prothetischen Versorgungsgrad und Behandlungsbedarf" aimed at
gaining data on the frequency and motives for dental visits and the existence of
barriers. The sample consisted of 714 subjects aged fifteen years and older. It
was representative for the German Federal State Saxony. Socio-economic and
behavioural data were collected via self-completed questionnaire. The caries
history was evaluated by assessing the DMFT Index. Data collection in 1996 was
carried out by three calibrated dentists. Utilisation of dental services was
found to be high. Subjective barriers played no crucial role in the decision to
utilise dental services. Costs as an objective barrier to dental visits had a
growing importance with age. Lower rates of tooth loss and enhanced levels of
restoration were found in subjects aged over 24 years who regularly utilised
dental services compared to subjects with non-regular utilisation. These
differences were significant for subjects over 54 years (tooth loss) and subjects
aged 25-44 years and over 54 years (level of restoration). Compared to previous
studies the utilisation was similar or higher in our sample. The enhanced oral
health belief paves the way for professional preventive measures. In the over 64
year-olds the need for regular dental visits was obvious and this age group must
definitely be given more relevant information on the subject.
PMID- 10666942
TI - [Statistically evaluated 95% prediction ranges as alternative to reference ranges
exemplified by polychlorinated dibenzo-p-dioxins/dibenzofurans and lead].
AB - Using the 95% prediction limits of an age-related multiplicative regression model
describing the datasets of blood examinations carried out on subjects suspected
of having been exposed to lead and to polychlorinated dibenzo-p
dioxins/dibenzofurans (PCDD/F), it was shown that the relevant curves can be used
as an alternative to reference ranges describing the actual background exposure
to these pollutants. The upper limit of the actual German background exposure can
be estimated by the following equations: PCDD/F as International Toxicity
Equivalents in the age range of 10-70 years [pg/g lipid basis] = 1.64.age0.871
and lead in the age range of 15-80 years [microgram/l] = 18.15.age0.3638.
PMID- 10666943
TI - [Public health today].
PMID- 10666944
TI - [Quality assurance and teamwork in social medicine expert assessment exemplified
by the expert assessment aid "corrective breast surgery" of the North Rhine
Health Insurance Medical Service].
AB - To standardise sociomedical expertising procedures in surgery of the breast a
project team of medical advisors of the Medical Advisory and Expertising Service
North Rhine worked out a manual. A form was created for sociomedical pre-advice
occasions. Detail parameters for examination (time needed and advisor selection)
were fixed in consent. Checklists were worked out, which may be admitted to
quality assurance procedures. The manual "Medical opinion for surgery of the
breast" has been implemented and is applied in the Medical Advisory and
Expertising Service North Rhine since January 1999. In the sense of teamwork
participation those who were involved as team-workers became participants in
decision-making. The manual "Medical opinion for surgery of the breast" may be
seen as an example of quality assurance and participation in socio-medical
opinion procedures. The influence of this manual on the formal quality of medical
opinion will be checked.
PMID- 10666945
TI - [Examples of methodological problems in evaluating misuse of hospital admission
and approaches to correction].
PMID- 10666946
TI - The role of telemedicine in medical education.
PMID- 10666947
TI - Awareness of, use and perception of efficacy of alternative therapies by patients
with inflammatory arthropathies.
AB - Fifty one patients with chronic inflammatory polyarthritis were surveyed on
unconventional treatments they used to self-treat their condition. Awareness of
the availability of alternative therapies (ATs) was universal. Sixty-six percent
(66%) of patients had tried one or more ATs. The most popular ATs were dietary
manipulation (no red meat, dosing with vinegar and honey), the wearing of magnets
and copper bracelets, and acupuncture. The best predictors of AT use were male
sex, Caucasian race and formal education beyond high school. Numbers were too
small to make definitive statements about perceptions of efficacy, but the users
of magnets and fish oils tended to be dissatisfied with these ATs, while those
who had tried bee stings, herbs and hormones claimed effectiveness.
PMID- 10666948
TI - Trends across two time periods in the diagnosis of substance abuse comorbidity at
the Hawaii State Hospital.
AB - This study investigates the changes from the late 1980s to early 1990s of
comorbidity (mental illness plus substance abuse) at the Hawaii State Hospital.
For the 1990s, a prevalence rate ranging from 14.2% to 30% was estimated, with
the latter figure based on a closer review of the records. A higher proportion of
comorbid clients were single, and compared to the non-abusers (i.e., patients
diagnosed with only schizophrenia or affective disorder), a higher percentage
were male and had an educational level less than high school. There was an
increase in the percent of non-abusers and substance abusers, but a decrease in
the dual diagnosed. The implications of these findings are discussed.
PMID- 10666949
TI - Clinical applications of hypnotherapy in a medical setting.
AB - Since 1958, hypnosis has been recognized by the American Medical Association as a
legitimate form of medical treatment when administered by an appropriately
trained practitioner. With the prevalence of certification societies and
international organizations, the specialty has increased its level of
professionalism and clinical applications. However, in spite of increased
exposure and utilization of this unique clinical application, its use within
medical settings varies considerably. The purpose of this article is to provide
an understanding of clinical hypnosis and offer clinical applications, with the
goal of increasing its exposure and utilization within medical settings.
PMID- 10666950
TI - [Morphometric analysis of nuclear variations in normal and neoplastic mammary
ductal cells].
AB - Morphometry is a method to detect changes in a variety of tissues through
quantitative elements. The purpose of this study was to examine several nuclear
morphologic characteristics in normal and neoplastic mammary ductal cells using a
multivariable method and expression of estrogen receptors by immunohistochemical
techniques. A total of 1879 nuclei were examined by a computerized program,
following the detection of estrogen receptors. Nuclear area, perimeter, diameter,
maximal and minimal radio were obtained in 439 normal ductal nuclei. The mean
nuclear area was 14.45 with a range between 10.88 and 17.90. Variables showed
adequate statistical correlation (r > 0.5). A total of 1440 neoplastic nuclei
were classified as grades I, II and III, and a statistical significative
difference was found between these three groups. We conclude that the nuclear
area is a reliable variable for statistical correlation being the ductal nuclei
anisotropic objects.
PMID- 10666951
TI - [Candida in biological human samples].
AB - Infections by Candida have been raising in the last decades, and risk factors,
mainly immunosuppression and the appearance of Candida no albicans, are
determinants in the prognosis of these mycoses. The purpose of this investigation
was to identify and establish the prevalence of C. albicans and Candida spp. in
candidiases, in patients to the Hospital Universitario de Maracaibo, whose
biological samples were processed for both direct examination and cultures,
needed for the proper identification. From October 1996 to October 1998,
isolation and identification of yeasts of Candida were performed in 177
biological samples: 73 (41.24%) Candida albicans and 104 (58.75%) Candida spp.
Both blastoconidias and pseudohyphae were found in 34 samples (19.21%), 24 of
which (70.5%) were diagnosed as C. albicans and 10 (29.5%), as Candida spp.
Blastoconidias identified by direct method were distributed as C. albicans 34.2%
and Candida spp. 65.7%. C. albicans was found more often in intertrigo, sputum
and in bronquial lavage samples. Candida spp. was more frequent in nails.
Candidiasis is a frequently diagnosed mycosis in hospitals, mainly among
immunossuppresed patients. It is very important to use direct microscopical
evaluation and cultures, in order to establish the presence of blastoconidias and
pseudohyphae, that will help to diagnose the aethiology and prevalence of
candidiasis. It is also important to recognize subungueal candidiasis in hospital
staff, that could spread the infection to inpatients.
PMID- 10666952
TI - [Analysis of prevalence of point mutations in codon 12 of oncogene K-ras from non
cancerous samples of cervical cytology positive for type 16 or 18 PVH].
AB - Ninety-one non cancerous samples from genital specimens positives for VPH 16 or
18 and 27 non-infected samples as controls were studied. Mutations at codon 12 in
K-ras gene was analyzed using enriched alelic PCR technique. Among the samples
studied 17.58% showed mutations in this codon. Significant differences were
observed between the control group (negative DNA-HPV) and positives DNA-HPV
samples (p < 0.01). No differences were found between both viral types in
relation to the mutation frequency. The presence of mutations in the K-ras gene
in non cancerous cytological samples point out new questions about the role of
mutations in proto-oncogenes and the development of cervical cancer.
PMID- 10666953
TI - Hypertrophic pulmonary osteoarthropathy in acquired immunodeficiency syndrome.
Case report and review.
AB - We describe a case of hypertrophic pulmonary osteoarthropathy (HPOA) in an adult
patient with acquired immunodeficiency syndrome (AIDS). This is the ninth case of
HPOA associated with AIDS in adults, reported in the literature. The presence of
pulmonary tuberculosis was also suspected, based on clinical grounds. Cases of
clubbing associated with AIDS infection are reviewed.
PMID- 10666954
TI - [The NADPH-oxidase complex in chronic granulomatous disease: preliminary
description of a cluster in Merida-Venezuela].
AB - Chronic Granulomatous Disease (CGD) is a primary immunodeficiency characterized
by an unusual predisposition to develop bacterial and fungal infections due to a
failure of phagocytic leukocytes to generate superoxide, required for the
intracellular killing of microorganisms. The lack of superoxide production is
secondary to a defect in the NADPH-oxidase enzymatic complex activation, as a
result of mutations of any of the components. Both, X-linked and autosomal
recessive patterns of inheritance have been demonstrated in this disease, being
the X-linked the most frequent and characterized by mutations in gp91phox.
Mutations in p47phox, p67phox and p22phox have been shown in the autosomal
recessive pattern. The molecular and genetic characteristic of NADPH-oxidase
complex and its pathology in CGD are reviewed along with a brief description of
the preliminary findings in two families from Merida, Venezuela.
PMID- 10666955
TI - Research assessment--a blessing in disguise?
PMID- 10666956
TI - Intra-oral topical anaesthetics: a review.
AB - OBJECTIVE: This review considers the use of topical anaesthetics in the mouth to
reduce the discomfort of local anaesthetic injections and intra-oral operative
procedures. DATA SOURCES: Electronic literature search using Pub Med, manual
search of references within papers found by the primary search and manual
searching of abstracts from scientific meetings. STUDY SELECTION: The articles
selected for this review investigate or used topical anaesthesia in dental
procedures. CONCLUSIONS: The use of topical anaesthetics does not guarantee pain
free dental local anaesthesia. Efficacy is dependent upon the duration of
application and the gauge of needle used. Evidence is available that the use of
topical anaesthesia alone is sufficient to perform some intra-oral procedures
including periodontal manipulations, operative dentistry and oral surgery.
PMID- 10666957
TI - The teaching of Class I and Class II direct composite restorations in European
dental schools.
AB - OBJECTIVES: The purpose of this descriptive study was to provide updated data on
the teaching of Class I and Class II direct composite restorations in Europe as
part of a survey of this aspect of the primary dental curriculum in Europe and
North America. METHODS: Data on the teaching of posterior composite restorations
and related matters were collected by means of a postal questionnaire sent to 185
dental schools known to exist in Europe. Non-respondents were sent a second
questionnaire after two months. Further information pertaining to student
requirements was sought after six months from all respondents. RESULTS: The
response ranged from 92% for dental schools in Scandinavia to 40% from dental
schools in Southern Europe with an overall response of 56%. All but four of the
104 participating schools were found to teach the use of composites in Class I
and Class II, two-surface situations in at least premolar teeth.
Contraindications and techniques taught for posterior composites varied within
and between the country groupings of Northern and Central Europe. Scandinavia,
Southern Europe and Eastern Europe. However, certain consensus views were
identified. The experience of adverse biological reactions to the use of resin
based restoratives in European dental schools was found to be limited.
CONCLUSIONS: Notwithstanding the variation in the response from the four
geographic regions investigated and the relatively low overall response to the
questionnaire, it is concluded that the data reported indicates that most dental
schools in Europe teach the use of composites in selected Class I and Class II
situations. However, considerable variation exists both within and between the
regions investigated in relation to this teaching. Further research and consensus
conferences should be planned to reduce variability across Europe in relation to
the contraindications and techniques taught for posterior composites.
PMID- 10666958
TI - Validity of the examination method of occlusal contact pattern relating to
mandibular position.
AB - OBJECTIVE: This study was based on the hypothesis that conflicting findings and
inconclusive consensus regarding the role of occlusal factors in the masticatory
system are due to the variations in the definitions and methods used to describe
and examine the occlusal factors. The object of this study was to determine
whether contact patterns during lateral movement vary with mandibular positions
and whether the contact pattern in lateral positions close to the maximum
intercuspation has characteristics distinct from those in an edge-to-edge
position. METHODS: Occlusal contacts of 86 young adults were examined using shim
stock in regulated lateral positions: 0.5, 1, 2 and 3 mm from the maximum
intercuspation, where the 0.5, 1 and 2 mm positions were defined as lateral
positions close to the maximum intercuspation and the 3 mm position as an edge-to
edge position. RESULTS: The occlusal contact pattern in the 0.5 mm position
showed a marked prevalence of posterior tooth contacts on the working and the non
working sides, compared with the 1, 2 and 3 mm positions. The occlusal contact
pattern in the 3 mm position predicted the presence or absence of the occlusal
contact in the 1 and 2 mm positions (sensitivity > 0.7) but not in the 0.5 mm
position (sensitivity < 0.6). CONCLUSION: The occlusal contact patterns during
lateral movement varied greatly with mandibular positions. The examination method
of the occlusal contact pattern in one unregulated position will be invalid. It
is necessary to distinguish the occlusal contact patterns between a position
close to the maximum intercuspation and an edge-to-edge position when
investigating its role in the masticatory system and in oral disease.
PMID- 10666959
TI - Investigations into the use of an ultrasonic chisel to cut bone. Part 1: Forces
applied by clinicians.
AB - OBJECTIVES: To measure in vitro the direction and force of applied loads applied
by clinicians when using both a conventional slow surgical handpiece (CH) and an
ultrasonic chisel (USC) for cutting bone. STUDY DESIGN: Five clinicians were
asked to cut bovine bone using either an USC or a CH. The bone was placed on a
force measurement system that could measure both longitudinal and downward loads.
The rate of cut was calculated over a fixed time-period and the depth of cut
measured using a penetratometer. RESULTS: The magnitude of the longitudinal
forces generated varied between 1.48 and 3.22 N (USC) and 0.04 and 4.56 N (CH).
The CH had a pulling force directed towards the operator. Both instruments
produced a similar range of downward forces although there was intra- and inter
operator variability. The rate of cut varied in a similar manner, however, the CH
produced a significantly greater depth of cut (p < 0.05). CONCLUSIONS: The force
measurement system demonstrated differences in the way clinicians used the USC
and CH instruments to cut bone. Of the two cutting methods investigated, the
rotary bur is more efficient than the ultrasonic chisel. An ultrasonic chisel
does cut bone in a different manner from a conventional bur and clinicians may
require training before using it clinically.
PMID- 10666960
TI - Investigations into the use of an ultrasonic chisel to cut bone. Part 2: Cutting
ability.
AB - OBJECTIVES: Ultrasound may offer a possible alternative to rotary instruments for
removing bone. This study was undertaken to analyse in vitro the various factors
that influence the cutting of bone by an ultrasonic chisel. STUDY DESIGN: A block
of bovine femur was moved in a longitudinal direction under a stationary
ultrasonic chisel. The force and depth of the cut was recorded for cutting rates
of 28-112 mm/min and with increasing rake angles of 0 to +20 degrees. The
pressure exerted by the chisel was recorded for different cutting rates. RESULTS:
When the cutting rate increases there is a corresponding increase in the downward
force which is followed by a decrease in the force at rates greater than 56
mm/min. The depth of the cut increases up to a rate of 56 mm/min after which it
decreases. Both the longitudinal and downward forces do not change when the rake
angle changes from 0 to +10 degrees. The downward force decreases when the rake
angle increases from +10 to +20 degrees. CONCLUSIONS: The bone is cut slowly with
the ultrasonic chisel, but this would assist in precision. Where such an
instrument is used for cutting bone the clinicians should be aware that both low
forces and cutting rates are required, and the instrument should be held at a low
rake angle.
PMID- 10666961
TI - Composition of the oral streptococcal flora in healthy children.
AB - OBJECTIVES: To identify the predominant streptococcal species in the mouths of
healthy children and to investigate the composition of the oral streptococcal
flora over a period of 4 months. PATIENTS AND METHODS: The subjects were 33 fit,
healthy schoolchildren aged between 5 and 16 years. These children were part of a
large study and were the matched controls for a group of subjects undergoing bone
marrow transplantation. The oral flora was sampled using an oral rinse technique
on two separate occasions 4 months apart. The outcome measures were the number of
each streptococcal species per millilitre of oral rinse; the isolation frequency
of each species; the proportion of each species as a percentage of both the total
streptococcal count and the total anaerobic count. RESULTS: The predominant
species were Streptococcus salivarius, S. oralis and S. mitis. There was no
significant variation in the composition of the oral streptococcal flora over the
4 month period. CONCLUSIONS: The oral rinse technique provides a reliable method
of sampling the streptococcal flora of children.
PMID- 10666962
TI - Adaptation of dental plaque to metabolise maltitol compared with other
sweeteners.
AB - There is some evidence that plaque can adapt to regular exposure to some bulk
sweeteners, leading to increased metabolism and acidogenic potential of the
sweetener. This potential for adaptation varies between non-sugar sweeteners and
has important implications for manufacturers of food, confectionery and medicines
used long-term. Maltitol (99% purity crystalline D-maltitol) is a relatively
newly approved non-sugar sweetener and appears to have potentially good dental
properties. OBJECTIVES: To compare plaque adaptation to pure sucrose, sorbitol,
xylitol or maltitol and the effect of their prolonged use on acid production by
plaque from sucrose, in vivo. METHODS: Two series of plaque pH experiments were
carried out. Each experiment involved a 14 day adaptive period when four 5 g
lozenges of the sweetener were taken between meals each day. Each experiment was
separated by a 14 day wash-out period. Acid production was quantified as: (a)
minimum pH; and (b) cH area (difference between plaque pH curve and resting
value, expressed as cH units). RESULTS: Thirteen adults, of mean age 41 years
completed the study. When adaptation of dental plaque to the metabolism of
sweeteners was compared, there was a statistically significant difference (p =
0.033) between xylitol and sorbitol, and between xylitol and sucrose but not
between xylitol and maltitol. When the effect of prolonged use of sweeteners on
acid production after sucrose rinsing was compared, there were no statistically
significant differences between the sweeteners. CONCLUSION: Dental plaque does
not adapt to metabolise xylitol or maltitol following prolonged exposure over 14
days.
PMID- 10666963
TI - Cytotoxic effects of composite restorations employing self-etching primers or
experimental antibacterial primers.
AB - OBJECTIVE: The aim of this study was to investigate the cytotoxic effects of
composites which employ proprietary self-etching primers or experimental primers
containing an antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide
(MDPB) on human pulpal cells by in vitro dentine barrier tests. METHODS:
Experimental primers were prepared by the addition of MDPB to each of two control
proprietary primers at 1, 2 and 5%. Direct and indirect composite specimens were
placed using each primer on one side of a dentine disk assembled in a simple pulp
chamber device. Human pulp cells were incubated on the other side of the disk.
After 48 h of incubation, the uptake of [3H]-thymidine by the cells was compared
with that for negative controls using wax. Tests were repeated four times for
each material. The diffusion of monomers from each specimen was determined using
the same device. RESULTS: The specimens with control primers showed 26-35%
reduction in cell activity. There were no significant differences in cytotoxicity
between the control and experimental primers-specimens (Kruskal-Wallis test, p >
0.05). 2-Hydroxyethyl methacrylate at more than 1 mg ml-1 diffused from all
specimens and was considered to be the cause of cytotoxic effects. The
concentrations of MDPB diffused from the experimental primers-specimens were less
than the toxic level, even for 5% MDPB-containing specimens. CONCLUSIONS: The
results demonstrate that composites employing proprietary self-etching primers
produced cytotoxic effects on human pulpal cells in vitro, although the toxicity
was not severe. Incorporation of MDPB into a proprietary primer of up to 5% had
no significant influence on the cytotoxicity observed.
PMID- 10666964
TI - Retentive and compressive strengths of modified zinc oxide-eugenol cements.
AB - OBJECTIVES: This investigation sought to improve the handling and physical
properties of a commonly used temporary zinc oxide-eugenol cement by changing the
base/accelerator (B/A) ratio or combining it with a petroleum jelly or fluoride
varnish. METHODS: Twelve modifications of a temporary cement were evaluated in
terms of retentive strength, compressive strength at 24 h, film thickness and by
scanning electron microscopy. RESULTS: Decreasing the B/A mixing ratio increased
the retentive and compressive strengths, but reduced the film thickness of the
cement. By increasing the percentage of incorporated petroleum jelly or fluoride
varnish in the cement, there was a progressive decrease in the retentive and
compressive strengths and in film thickness. CONCLUSIONS: Modifications of a zinc
oxide-eugenol temporary cement to change the B/A ratio or to incorporate
additives resulted in variations in physical properties. All modified forms of
the cement had a film thickness less than 25 microns and a compressive strength
below 35 MPa. With a wide range of retentive strength, modified forms of zinc
oxide-eugenol cement may be found to have diverse clinical applications.
PMID- 10666965
TI - Designing new treatment strategies in vital pulp therapy.
AB - OBJECTIVES: The development of strategies in vital pulp therapy, which aim to
maintain vitality and function of the dentine-pulp complex, represents a major
focus of attention. Recent progress in understanding the molecular and cellular
changes during tooth development and how they are mimicked during dental tissue
repair offers the opportunity to now assess whether this knowledge can be
exploited to design new treatment strategies in vital pulp therapy. DATA SOURCES
AND STUDY SELECTION: Current literature on the molecular and cellular basis of
tooth development and dental tissue repair has been reviewed in the context of
stimulating dentinogenic responses in the tooth together with pertinent published
abstracts of relevant conferences and personal communications. Tissue events of
direct relevance to clinical application for vital pulp therapy are discussed.
CONCLUSIONS: The involvement of growth factors and extracellular matrix molecules
in signalling and regulating dentinogenic events during tooth development has
been identified. During dental tissue repair, many of the processes are mimicked
leading to responses of focal deposition of tertiary dentine at injury sites. The
nature and specificity of these responses are determined in part by the extent of
tissue injury. Traditional clinical strategies are capable of exploiting
endogenous signalling molecules in the tissues to develop more effective
treatment modalities. Application of exogenous signalling molecules offers
opportunities for development of new therapies, although a number of delivery
considerations must be addressed before these can be introduced into clinical
practice.
PMID- 10666966
TI - Subgingival calculus: where are we now? A comparative review.
AB - OBJECTIVE: To critically analyse the formation, composition, ethnic variations
and pathogenic potential of subgingival calculus in comparison with supragingival
calculus. DATA SOURCES: Using CD-ROM and index medicus, scientific papers
relating to subgingival calculus or subgingival and supragingival calculus
written in the English language since 1960 were considered, with the emphasis on
more recent articles. STUDY SELECTION: Studies were selected for their relevance
and contemporary nature re:composition and formation of dental calculus and
comparisons of ethnic groups with regard to dental calculus, especially
subgingival calculus. Some similar studies were not included. DATA EXTRACTION:
Abstracts of studies were kept brief unless particularly important to the review.
Population, methodology, statistics and accurate conclusions were used as
important guides to the quality and validity of studies. DATA SYNTHESIS:
Similarities and differences between supragingival and subgingival calculus in
composition and formation were shown. Different morphological types of
subgingival calculus were demonstrated. There was evidence for an association
between calculus formation and ethnicity with regard to supragingival and
subgingival calculus, and an association between subgingival calculus composition
and ethnicity was indicated. CONCLUSIONS: An association between ethnicity and
subgingival calculus formation and composition was found. Further research into
the reasons for these ethnic differences in dental calculus and the role of the
mineral constituents especially of subgingival calculus would be valuable.
PMID- 10666967
TI - Iatrogenic damage to approximal surfaces in contact with Class II restorations.
AB - OBJECTIVES: This study investigated the frequency of iatrogenic damage to
approximal surfaces in contact with Class II restorations. METHODS: Patients (n =
28) with a Class II restoration in contact with an unrestored surface had elastic
separators fitted interproximally. Contralateral (unrestored) control surfaces
were also separated. Impressions (light body polyvinylsiloxane) of the separated
surfaces were taken 3-6 days later. Interproximal impressions (28 paired, seven
unpaired) were examined by binocular microscope and scanning electron microscope
(SEM) for iatrogenic damage, attrition and cavitation due to caries. RESULTS: 49
60% of surfaces adjacent to Class II restorations had been iatrogenically
damaged. The most frequent types of damage were vertical grooves (26%), extensive
damage (17%), indentations (6%) and scratches (6%). Damage was more frequent in
maxillary teeth (61%) than mandibular teeth (25%), in permanent teeth (60%) more
than deciduous teeth (20%). Qualified dentists produced more iatrogenic damage
(64%) than undergraduate students (23%). CONCLUSION: The frequency of iatrogenic
damage to approximal surfaces following Class II preparations was 49%, and
possibly as much as 60% when questionably damaged surfaces were included.
Protection of the adjacent enamel is of paramount importance during Class II
cavity preparation.
PMID- 10666968
TI - A five-year clinical evaluation of Class II composite resin restorations.
AB - OBJECTIVES: To study the clinical efficacy of posterior composite resin
restorations placed in general practice after five years. METHODS: Two commercial
composite resin systems were used. Three general practitioners placed the
restorations at a Public Dental Health Service Office. The patients were not
selected specifically for this study. Class II cavities were restored with
Superlux Molar and P-50 APC composite systems on an alternate basis. At baseline,
63 restorations were placed in molars and premolars in 45 patients. For primary
caries, generally a conservative cavity design was used (n = 23), while
replacements of amalgams resulted in the larger conventional Class II design (n =
40). The restorations were assessed using a modified USPHS criteria. Wear
measurements were determined by the Leinfelder method. Photographs and bite-wing
radiographs were taken to supplement the clinical evaluation of colour match,
marginal adaptation and recurrent caries. Saliva sampling was performed to
determine the rate of secretion and the level of mutans streptococci and
lactobacilli. RESULTS: At the five-year review 51 restorations were available for
examination, of which nine restorations were rated clinically unacceptable.
Including the failed restorations (n = 7), at the three-year review, a total of
16 restorations had failed (27.6%) over a five-year period. The most common
reasons for failure were recurrent caries (n = 7) and marginal defects (n = 4).
The mean wear of Superlux Molar was 167 microns and of P-50 APC 158 microns.
Eight of the 11 patients with failed restorations due to caries and marginal
defects had high counts of mutans streptococci at baseline. CONCLUSIONS: The
failures in the present group of patients did not specifically relate to
material, tooth type or cavity design. However, it is suggested that patient
factors such as caries activity should be monitored and managed.
PMID- 10666969
TI - Three-year clinical evaluation of a polyacid-modified resin composite in
minimally invasive occlusal cavities.
AB - OBJECTIVE: The aim of this study was to evaluate the 3-year clinical performance
of one polyacid-modified resin composite material (PMRC). Dyract, in minimally
invasive occlusal cavities and its neighbouring fissures. METHODS: One hundred
and sixteen restorations of the material investigated were placed by a single
operator in a group of selected children under controlled conditions. Isolation
of the restorations was accomplished with the use of cotton rolls and aspiration.
Using modified US Public Health Service (USPHS) codes and criteria, the
restorations were reviewed clinically within 1 week of placement (baseline), and
thereafter at 6 months, 1, 2 and 3 years. RESULTS: After 3 years, marginal
discolouration was present in 8.6% of the restorations. The marginal adaptation
was rated as partly sealed (Oscar-Alpha) in 107 (92.2) of the restorations. Five
restorations had lost their sealant components, while four restorations were
partly sealed with explorer-catch after 3 years. Although wear of the
restorations was considerable, restorations rated as 'partly sealed' had at least
two-thirds of their sealant components fully retained. Recurrent caries was
associated with four (3.4%) restorations. CONCLUSION: In this clinical study, the
retention rate of the tested PMRC material was good, although a marked occlusal
wear was evident. The marginal adaptation of the PMRC at the enamel site would
probably have been better by the use of enamel-etching. Provided the marginal
adaptation and wear resistance of the material is further improved, clinical use
of PMRCs in minimally invasive occlusal cavities can be advocated.
PMID- 10666970
TI - Clinical evaluation and microstructural analysis of a direct placement gallium
restorative alloy.
AB - OBJECTIVES: The objective of this study was to assess the clinical performance of
a direct placement gallium alloy sealed with an established dentine adhesive
system. In addition, microanalysis of a few gallium restorations that failed in
clinical service was performed. Clinical factors such as pulpal sensitivity,
fracture of the restoration and of the tooth, marginal deterioration, and tarnish
were assessed. METHODS: Sixty-five restorations of Galloy and 62 of Tytin (49 and
51 Class II restorations, respectively) were placed according to a predetermined
scheme for randomisation in 37 patients by two operators using rubber dam
isolation. For the Galloy restorations, the enamel and dentine were etched, and
then sealed with PAAMA 2 dentine adhesive according to the manufacturer's
instructions. After carving, PAAMA 2 was applied to the Galloy and light-cured.
Cavity preparations for Tytin received no adhesive sealer. All restorations were
polished at least 24 h post-operatively. Microstructural analysis of retrieved
fragments of failed restorations was conducted using electron probe
microanalysis. RESULTS: At 1 year, only one Tytin restoration was found to have
failed due to an isthmus fracture. The remaining restorations of Tytin were
intact with no reported sensitivity. Of the 65 Galloy restorations placed, 28 had
to be removed, including restorations in teeth, which were symptomatic, non-vital
and/or fractured, and teeth with fractured restorations. Tarnish was present on
many of the Galloy restorations. Retrieved fragments of failed Galloy
restorations exhibited a dark surface at the pulpal wall interface and small
cracks were observed in that surface. Internal cracks and extensive corrosion was
observed using the microprobe. Gallium oxides and chlorides were identified as
the predominant corrosion products. CONCLUSIONS: The gallium alloy, Galloy,
sealed with PAAMA 2 dentine adhesive system demonstrated a high clinical failure
rate.
PMID- 10666971
TI - Accuracy of estimation of dental treatment need in special care patients.
AB - OBJECTIVES: To assess the ability of carers and dental professionals to estimate
treatment need in a group of children and adults with special needs. METHOD: A
retrospective study of a series of 103 special needs patients who had received
restorative dental treatment under general anaesthetic was undertaken. The
initial reason for attendance and the time lapse between first symptoms and
decision to consult were established. The parent or carer was asked to estimate
treatment need and to assess the degree of discomfort suffered by the patient.
The dentist evaluated treatment need by means of a pre-operative treatment plan.
These results were compared to actual treatment performed. RESULTS: Treatment
need was severely underestimated by both carer and dentist. The degree of
advanced pathology found in the population would suggest that pain suffered was
also underestimated. CONCLUSIONS: Access of patients with special needs to dental
care may be limited by the ability of their carers to evaluate their oral
condition and/or by the persons inability to express their pain or discomfort.
PMID- 10666972
TI - Usage of denture adhesives.
AB - OBJECTIVES: There have been few reports in the dental literature on the number of
denture wearers who regularly use denture adhesive. The objectives of this study
were to see what the incidence of usage of denture adhesive was by a surveyed
edentulous population, to determine the degree of success of its usage and the
reasons for its current use or nonuse. METHODS: In this study, 146 patients
attending the Adelaide Dental Hospital for denture treatment were surveyed
regarding their usage of denture adhesive, using a prepared questionnaire. The
surveyed group was divided into three categories--those who had never tried
denture adhesive, those who had tried denture adhesive but no longer used it, and
those who currently used denture adhesive. RESULTS: In the survey, there were 52
males (35.6%) and 94 females (64.4%) and 96 (65.7%) were over 60 years of age. Of
these 78 patients (54.9%) had worn their dentures for 10 years or more, and 26
(17.8%) for 20 years or more. A total of 98 patients (67.1%) had never tried
denture adhesive: 48 patients (32.9%) had tried denture adhesive but only 10
(6.9%) currently used it. Various reasons for trying denture adhesive and for its
continued use or nonuse were given. CONCLUSIONS: In this study, 52% of patients
surveyed saw no need for the use of denture adhesive as they managed their
dentures well; 20.5% of patients did not know that denture adhesives existed; and
32.9% had tried denture adhesive but only 6.9% continued to use it on a regular
basis.
PMID- 10666973
TI - A new imaging technique for measuring the surface strains applied to dentine.
AB - OBJECTIVES: To investigate possible variation in directional material properties
of dentine in relationship to tubule orientation using a new optical imaging
technique. METHOD: The optical imaging technique records photometrically a grid
pattern formed by using a transmission electron microscope grid as a template on
the polished surface of the dentine. The grid pattern is silhouetted onto the
sample surface using standard techniques. Compression (c) and diametral
compression (dc) tests were undertaken using a servo hydraulic testing machine
(MTS model 810) acting on rectangular blocks of dentine with dimensions 1.5 x 1.0
x 1.0 mm (for c) and cylindrical samples with dimensions 2.1 mm in diameter and 1
1.5 mm thick (for dc), respectively. The samples were cut using a diamond wheel
and miniature lathe and the cut surfaces polished. Images due to a changing load
profile were captured and stored as digitised files on a computer for later
analysis. The precision is mainly determined by the pixel resolution of the
charged-coupled device camera. RESULTS: Preliminary results show the value of
elastic modulus of dentine (10.4 +/- 2.9 GPa) to be similar to those previously
reported in the literature. Very small localised strains at the surface of a
sample can be observed qualitatively and measured quantitatively by reference to
the line spacing (approximately 85 microns). Maximum strength varied with tubule
orientation and (compressive/tensile) stress. CONCLUSION: Very small samples of
dentine may be investigated for strain in more than one direction using the
imaging technique described. These results may be more appropriate for finding
relative directional change rather than obtaining the elastic properties of the
dentine.
PMID- 10666974
TI - Effects of pH and concentration of citric, malic and lactic acids on enamel, in
vitro.
AB - OBJECTIVE: Dental erosion associated with soft drink consumption probably results
from the contained dietary acids in the formulations. The pH value of any
formulation is an important variable in acid erosion but not necessarily the only
important factor. The aim of this study was to measure enamel erosion by citric,
malic and lactic acids at pH values and acid concentrations representative of a
range found in soft drink formulations and to determine the effect of adding
calcium to citric acid. METHODS: Flat ground enamel samples were prepared from
unerupted human third molar teeth. Groups of five specimens were placed in
citric, malic and lactic acid solutions of different pH and acid concentration
for three by 10 min exposures at 35 degrees C. Enamel loss was measured by
profilometry. Enamel specimens were also exposed to citric acid solutions
containing calcium at different pH values and at the same pH with different
concentrations of calcium. RESULTS: Numerical data and contour plots for each
acid showed a similar pattern for increasing erosion with decreasing pH and
increasing acid concentration and vice versa for decreasing erosion. Increasing
the concentration of calcium in a fixed pH citric acid solution resulted in
decreased erosion. This effect was most marked at higher pH. CONCLUSIONS: This
study has shown that under highly controlled conditions the erosion of enamel by
solutions of dietary acids is influenced by the interplay of pH, acid
concentration and presence of calcium. These variables and in particular the
concentration of calcium could be manipulated to produce soft drinks with reduced
erosivity to enamel.
PMID- 10666975
TI - Accuracy and criteria for localizing arterial occlusion with transcranial
Doppler.
AB - The authors determined transcranial Doppler (TCD) accuracy for the proximal
internal carotid artery (ICA), distal ICA, proximal middle cerebral artery (MCA),
distal MCA, anterior cerebral artery (ACA), posterior cerebral artery (PCA),
terminal vertebral artery (tVA), and basilar artery (BA) occlusion in cerebral
ischemia patients. Detailed diagnostic criteria were prospectively applied for
TCD interpretation independent of angiographic findings. Of 320 consecutive
patients referred to the neurosonology service with symptoms of cerebral
ischemia, 190 (59%) patients also underwent angiography (MRA or DSA). 48 of those
190 patients had angiographic occlusion and 12 of those 48 patients had
involvement of multiple vessels. Median time from TCD until angiography was
performed was 1 hour (41 patients had angiography before TCD). TCD showed 40 true
positive, 8 false negative, 8 false positive, and 134 true negative studies with
sensitivity 83.0%, specificity 94.4%, positive predictive value 83.0%, negative
predictive value 94.4%, and accuracy 91.6% to determine all sites of occlusion.
Sensitivity for each individual occlusion site was: proximal ICA 94%, distal ICA
81%, MCA 93% tVA 56%, BA 60%. Specificity ranged from 96% to 98%. TCD is
sensitive and specific in determining the site of the arterial occlusion using
detailed diagnostic criteria, including proximal ICA and distal MCA lesions. TCD
has the highest accuracy for ICA and MCA occlusions. If the results of TCD are
normal, there is at least a 94% chance that angiographic studies will be
negative.
PMID- 10666976
TI - Periventricular white matter hyperintensities on MRI: correlation with
neuropathologic findings.
AB - Periventricular white matter hyperintensities on postmortem magnetic resonance
imaging (MRI) and myelin-stained frontal and parietal histologic sections were
evaluated independently in 12 cases. There was a strong relationship between the
extent of white matter hyperintensities on MRI and the extent of gross and
microscopic changes seen in the white matter of myelin-stained sections,
particularly in the frontal lobe. In this material, the extent of myelin
rarefaction correlated with a 0- to 8-point white matter hyperintensity scale
rating on MRI in the same brains.
PMID- 10666977
TI - Color-coded duplex ultrasonography of the origin of the vertebral artery: normal
values of flow velocities.
AB - The introduction of color-coded duplex ultrasonography has improved the ease of
performing ultrasound investigations of the vertebral arteries. So far, normal
values of flow velocities have been reported only for the intertransverse region
of the vertebral artery (V2 segments). Atherosclerotic disease at the origin of
the vertebral arteries (V0 segment) is frequent and is one of the risk factors
for vertebrobasilar ischemic disease. Normal values of flow velocities of the
vertebral artery origin are needed to assess pathologic findings, such as
vertebral artery origin stenosis or dissection. The aim of this study was to
describe the normal flow velocities of vertebral artery origin (V0 segment) and
the pre- (V1 segment) and intertransverse (V2 segment) part in 50 age-matched
neurologic patients (mean age 54) without ischemic cerebral disease. The V0
segment could be visualized in 46 persons (92%) on the right side and in 43 (86%)
on the left. The peak systolic blood velocity ranged from 30 to 100 cm/s (mean
63.6 +/- 17.5 cm/s), and end-diastolic blood velocity ranged from 10 to 35 cm/s
(mean 16.1 +/- 5.1 cm/s). Analysis of side-to-side differences showed no
significant differences of flow velocities in all subjects. It is concluded that
color duplex ultrasonography is a feasible method to insonate the origin of the
vertebral artery, and that nomogram data could be established. It is suggested
that color-coded duplex ultrasonography of the vertebral artery origin should be
performed in all patients with clinical symptoms or signs of vertebrobasilar
ischemic disease. Nevertheless, further studies are needed to determine the
normal and pathologic values of flow velocities of the vertebral artery origin
and their reproducibility.
PMID- 10666978
TI - Hyperkinetic movement disorders caused by corpus striatum infarcts: brain MRI/CT
findings in three cases.
AB - Three patients with hemichorea/hemiballismus/hemidystonia caused by discrete
contralateral infarction of the corpus striatum are presented. The infarcts were
all small on CT or MRI brain scan and were lacunar in type. Small discrete
infarction of basal ganglionic structures allows such adventitious movements to
be manifested. Involvement of contiguous areas, seen with larger infarcts, can
suppress such movements. The infrequency of such hyperkinetic movement disorders,
and the subtle infarct appearance on brain scan, can lead to a delay in the
diagnosis.
PMID- 10666979
TI - Intracranial clot dissolution is associated with embolic signals on transcranial
Doppler.
AB - Reperfusion of intracranial arteries can be detected by transcranial Doppler
(TCD). The authors report microembolic signals (MES) on TCD as a sign of clot
dissolution and recanalization. Microembolic signals were detected during routine
diagnostic TCD examination performed in the emergency room in patients eligible
for thrombolytic therapy. Microembolic signals were found at the site of M1
middle cerebral artery (MCA) high-grade stenosis or near-occlusion. Transcranial
Doppler was performed before, during, and after thrombolytic therapy. Of 16
consecutive patients, 3 (19%) had MES on TCD. All three patients had a severe MCA
syndrome at 2 hours after stroke onset scored using the National Institutes of
Health Stroke Scale (NIHSS). In patient #1 (NIHSS 12), clusters of MES were
detected distal to a high-grade M1 MCA stenosis preceding spontaneous clinical
recovery by 2 minutes. Because of subsequent fluctuating clinical deficit,
intraarterial thrombolysis was given with complete recovery. In patient #2 (NIHSS
20), TCD detected an M1 MCA near-occlusion. At 1.5 hours after intravenous tissue
plasminogen activator, TCD showed minimal MCA flow signals followed by MES,
increased velocities, and normal flow signals in just 2 minutes. She gradually
recovered up to NIHSS 8 in 5 days. In patient #3 with NIHSS 22 and an M1 MCA near
occlusion, TCD detected MES 15 minutes after TPA bolus followed by MCA flow
velocity improvement from 15 cm/sec to 30 cm/sec. The patient recovered
completely by the end of tissue plasminogen activator infusion. The authors
conclude that embolic signals detected by TCD at the site of arterial obstruction
can indicate clot dissolution. Intracranial recanalization on TCD can be
associated with MES and changes in flow waveform, pulsatility, and velocity if
insonation is performed at the site of arterial obstruction.
PMID- 10666980
TI - Caffeine can affect velocity in the middle cerebral artery during
hyperventilation, hypoventilation, and thinking: a transcranial Doppler study.
AB - This study examined possible caffeine-mediated changes in blood flow velocity in
the middle cerebral artery (VMCA) induced by tests of cerebrovascular
responsiveness. Transcranial Doppler (TCD) sonography provided simultaneous
bilateral VMCA measures while healthy college students hypoventilated,
hyperventilated, and performed cognitive activities (short-term remembering,
generating an autobiographical image, solving problems), each in 31-second tests.
VMCA measures were obtained from the same persons, in separate testing sessions,
when they were noncaffeinated and under two levels of caffeine: a smaller amount
(from a cola, 45 mg/12 oz) and a larger amount (from coffee, 117 mg/8 oz).
Compared with the no-caffeine control condition, a smaller amount of caffeine had
no significant effects on global VMCA, but a larger amount suppressed VMCA by
5.8%. Time-course analyses showed that VMCA (1) followed a triphasic pattern to
increase over baselines during hypoventilation regardless of caffeine condition,
(2) slowed below baselines during hyperventilation (with the degree of slowing
attenuated under caffeine), and (3) increased over baselines during all cognitive
activities (ranges 3.8-6.9%). It is concluded that a large amount of caffeine can
suppress VMCA, and this possibility should be anticipated when TCD is used to
assess cerebral hemovelocity.
PMID- 10666981
TI - Registration of neuroimaging data: implementation and clinical applications.
AB - Image registration brings images into a form in which each voxel corresponds to a
predetermined anatomic entity and is necessary for comparisons of data across
scans. Intrasubject registration is a matter of translating and rotating one
image volume into correspondence with another. Intersubject registration is more
difficult because it requires the removal of individual anatomy dependence from
the data. This article describes, with the help of clinical examples, automated
methods for intrasubject registration of scans within and between modalities, and
intersubject registration used for registering a three-dimensional brain atlas
with a patient's brain scan.
PMID- 10666982
TI - Basilar artery endoprosthesis placement: rescue therapy for recurrent thrombosis.
AB - Hyperacute thrombosis of the basilar artery accompanied urgent treatment of
basilar thrombosis with local thrombolytics and arterial reconstruction by
balloon angioplasty. Successful placement of an endoprosthesis into the basilar
artery permitted sustained restoration of blood flow. To the authors' knowledge,
this is the first successful report of intracranial endoprosthesis deployment.
PMID- 10666983
TI - The air we breathe.
PMID- 10666984
TI - Health and the environment
PMID- 10666985
TI - Water quality and public health in Georgia.
PMID- 10666986
TI - Trash talk: burned and buried medical waste threatens Atlanta's environmental
health.
PMID- 10666987
TI - Expanding the physician's role in pediatric environmental health.
AB - In rural Georgia, a nurse and an environmental health specialist from the local
health department visit the home of a young nursing mother to evaluate her home
for the presence of lead hazards. The mother's older child, a 3-year old girl,
has a blood lead level of 22 micrograms per deciliter, which was discovered
through routine (EPSTD) health department screening. In examining the home, the
specialist finds classic environmental risks; peeling and chipping lead-based
paint on windows and door frames, lead dust on window wells and floors, and a
backyard that serves as a burial ground for defunct car parts and dead batteries.
In the course of talking with the mother about the lead hazards he has found, he
notices that she and her 8-week-old infant seem quite listless, so he asks the
mother how she's coping with her new baby. Eventually, the mother discloses that
during her pregnancy she craved dirt and that she had eaten bowels of it scooped
from her backyard. Once she had the baby, she says, she lost her craving. The
nurse immediately contacts the physician involved in this case, who arranges for
the mother and infant to be admitted to a nearby medical center for chelation
therapy. Testing reveals the mother's lead level at 90 micrograms per deciliter;
the infant's level is staggering 85 micrograms per deciliter. Once lead levels
are reduced,the physician and public health nurse arrange for a host of social
services, including psychological and nutritional counseling for the mother and
periodic retesting of the children. The family moves from the dilapidated rental
home. However, the mother misses her appointments, and despite repeated attempts
to locate her, the family is lost to follow-up.
PMID- 10666988
TI - Air pollution and health: what Georgia physicians should know.
PMID- 10666989
TI - Is universal screening for lead in children indicated? An analysis of lead
results in Augusta, Georgia in 1997.
AB - Pediatricians have a dilemma about whether they should do universal or targeted
screening for lead in children. In order to determine whether we should continue
our institution's present policy of universal screening, we analyzed 962 lead
samples obtained by routine screening in the calendar year 1997, 83 children
(8.6%) had elevated levels (over 10 mcg/dl) by capillary samples; of the 57
children who had follow up tests by venipuncture, 35 had abnormal levels making
the incidence of elevated leads in our screened children 3.6%. Most of the
abnormal levels were in African-American children living in two downtown zip
codes. Based on recent AAP recommendations, in our community, targeted screening
should replace universal screening.
PMID- 10666990
TI - Endocrine disrupters: an emerging environmental health problem.
PMID- 10666991
TI - What physicians can do for the environment.
PMID- 10666992
TI - Exposure to contemporary-use pesticides.
PMID- 10666993
TI - Monitoring the prevalence of congenital hypothyroidism for 20 years near the
Savannah River site.
AB - OBJECTIVES: The main objectives were to describe the epidemiology of primary
congenital hypothyroidism (CH) in Georgia during the past 20 years and
specifically to determine whether there was a significant increase in CH
prevalence proximal to the Savannah River Site (SRS), a nuclear plant. METHODS:
Data were derived from the Georgia Newborn Screening Program. Frequencies were
determined for race, sex, birth weight and birth month. Seasonality effects were
investigated and the prevalence was determined and mapped by health district.
RESULTS: The majority of the CH cases were female, white and of average birth
weight. The sex ratio varied by race/ethnicity. There was not a statistically
significant increase in the prevalence in the eastern districts that were in
close proximity to the SRS. CONCLUSIONS: Although there were differences in the
prevalence between health districts, we found no increased prevalence of CH in
those health districts proximal to the SRS.
PMID- 10666994
TI - A Christian discovers the environmental crisis.
PMID- 10666995
TI - Judaism and the environment.
PMID- 10666996
TI - Focus on independence.
PMID- 10666997
TI - An index of environmental burden: Georgia 1999.
PMID- 10666998
TI - Healthy homes.
PMID- 10666999
TI - New approaches to the detection and prevention of iron-deficiency anaemia.
PMID- 10667000
TI - Current breastfeeding knowledge, attitude, and practices of mothers in five rural
communities in the Savannah region of Nigeria.
AB - The knowledge, attitude, and practices regarding breastfeeding of 310 mothers in
five rural communities in Toto Local Government in Nassarawa State, Nigeria were
investigated using a questionnaire. One hundred and sixty-two (52.3 per cent)
mothers were illiterate while 148 (47.7 per cent) had either primary or secondary
school education. Apart from giving babies colostrum, which was seen more amongst
mothers with higher levels of education (p < 0.001), other practices investigated
such as exclusive breastfeeding, demand feeding, 'rooming-in', and time of first
breastfeed were not influenced by the mother's level of education. Fifty-four per
cent of mothers did not give their babies colostrum. All mothers attended the
antenatal clinic but only 103 (33.3 per cent) received instructions from the
health worker on breastfeeding and 46.8 per cent delivered at home. Only 28.6 per
cent of babies were breastfed within 24 hours of birth. The mean time after birth
for the first breastfeed was 47.7 hours. Although breastfeeding is widely
practiced, none of the babies was exclusively breastfed, and prelacteal feeds
ranging from water, formula, or herbal tea were given by all the mothers. The
practice of discarding colostrum and replacing it with a wide range of prelacteal
feeds and late initiation of breastfeeding has implications for health education
programmes and neonatal feeding strategies.
PMID- 10667001
TI - Spontaneous and provoked growth hormone (GH) secretion and insulin-like growth
factor I (IGF-I) concentration in patients with beta thalassaemia and delayed
growth.
AB - Growth retardation in children with thalassaemia major is multifactorial. We
studied the growth hormone (GH) response to provocation by clonidine and
glucagon, measured the circulating concentrations of insulin, insulin-like growth
factor-I (IGF-I), IGF-binding protein-3 (IGFBP3), and ferritin, and evaluated the
spontaneous nocturnal (12 h) GH secretion in prepubertal patients with
thalassaemia and age-matched children with constitutional short stature (CSS)
(height SDS < -2, but normal GH response to provocation). The anatomy of the
hypothalamic pituitary area was studied in patients with abnormal GH secretion
using MRI scanning. Children with thalassaemia had significantly lower peak GH
response to provocation by clonidine and glucagon (8.8 +/- 2.3 micrograms/l and
8.2 +/- 3.1 micrograms/l respectively) than did controls (17.6 +/- 2.7
micrograms/l and 15.7 +/- 3.7 micrograms/l respectively). They had significantly
decreased circulating concentrations of IGF-I and IGFBP3 (68.5 +/- 19 ng/ml and
1.22 +/- 0.27 mg/l respectively) compared to controls (153 +/- 42 ng/ml and 2.16
+/- 0.37 mg/l respectively). Seven of the thalassaemic children had a GH peak
response of < 7 micrograms/l after provocation. Those with a normal GH response
after provocation also had significantly lower IGF-I and IGFBP3 concentrations
than controls. Analysis of their spontaneous nocturnal GH secretion revealed
lower mean (2.9 +/- 1.77 micrograms/l) and integrated (2.53 +/- 1.6 micrograms/l)
concentrations compared to controls (4.9 +/- 0.29 micrograms/l and 5.6 +/- 0.52
micrograms/l respectively). Five of them had mean nocturnal GH concentration < 2
micrograms/l and four had maximum nocturnal peak below 10 micrograms/l. These
data denoted defective spontaneous GH secretion in some of these patients. MRI
studies revealed complete empty sella (n = 2), marked diminution of the pituitary
size (n = 4), thinning of the pituitary stalk (n = 3) with its posterior
displacement (n = 2), and evidence of iron deposition in the pituitary gland and
midbrain (n = 7) in those patients with defective GH secretion (n = 9). Serum
ferritin concentration was correlated significantly with the circulating IGF-I (r
= -0.47, p < 0.01) and IGFBP3 (r = -0.43, p < 0.01) concentrations. These data
prove a high prevalence of defective GH secretion in thalassaemic children
associated with structural abnormality of their pituitary gland.
PMID- 10667002
TI - Role of intrauterine growth retardation on physical growth of Pakistani squatter
children from birth to 2 years of age.
AB - A birth cohort of 727 squatter children from Karachi was followed to study growth
patterns by measuring anthropometric parameters at specific ages during the first
2 years of life. The mean weight and length of the intrauterine growth retarded
and appropriate for gestational age children fell below the 10th percentile of
the NCHS standards after 9 months and further deteriorated in the subsequent
study period. However, the intrauterine growth retarded children showed slightly
higher growth velocities compared to appropriate for gestational age children in
the first few months for all four measurements, but subsequently these
differences in growth velocities diminished. Our results suggest that nutrition
intervention strategies should begin in early pregnancy.
PMID- 10667003
TI - Comparison of four anthropometric methods of nutritional assessment and
evaluation of the agreement between two reference populations.
AB - A total of 841 children, aged 10 days to 5 years, seen at a primary health care
centre in Ribeirao Preto, Brazil, were studied in order to compare the methods of
Gomez, Waterlow, Shakir, and Kanawati and McLaren and to determine the
correlation between the Brazilian and the National Center for Health Statistics
(NCHS) reference populations, which are frequently used in Brazil. Anthropometric
measurements (weight, height, arm circumference, and head circumference) were
made and personal data were obtained in order to evaluate nutritional status
according to the above methods. The two reference populations were compared by
the method of Gomez. The NCHS and the Brazilian reference populations were
concordant. Comparison of the methods of Gomez and Shakir showed a very mild
agreement in the evaluation of nutritional status. Comparison of Waterlow
'wasting' with Kanawati & McLaren and with Gomez showed a mild agreement.
PMID- 10667004
TI - Evaluation of the effect of a breastfeeding message integrated into a larger
communication project.
AB - Most breastfeeding project evaluations examine the effects of separate projects
and many do not use experimental designs. We evaluated the impact during the 3rd
year (March 1992-March 1993) of a simple breastfeeding message integrated into a
large-scale 3 year vitamin A project in northern Bangladesh. It encouraged
mothers to breastfeed for at least 2 years. Less formally, mothers were also
advised to give colostrum. In both project (experimental) and non-project
(control) areas, the proportion of mothers of children aged 1-6 years who said
they gave colostrum increased from about 69 per cent to about 77 per cent.
However, children born during the year that transpired between the pre- and post
surveys were too young to be included in the post-survey. Thus this difference is
an example of women reporting what they perceived as the norm or the 'correct'
answer instead of what they actually did with their children. Thus the norm
changed during the evaluation year, but it did so equally in both project and non
project areas. Although reported breastfeeding levels remained stable among older
groups, the proportion of children in the 2nd and 3rd years of life reported to
be currently breastfeeding increased to a similar extent in both areas. This
could indicate either a change in perception or a change in behaviour. Suckling
frequency, not mentioned in local or national breastfeeding promotion, was
unchanged in both areas at about 15 times a day for children in the 2nd year of
life, and maintained at about eight to 10 times a day even for the small
proportion who were still breastfed in the 5th (about 9 per cent) or 6th (about 2
per cent) years of life. While project messages (especially by radio) could have
spread to the nearby non-project area, it is unlikely that the impact would be
equal. More likely these changes were the result of secular changes occurring at
this time throughout Bangladesh. Thus this evaluation found no evidence that the
integration of a simple message about breastfeeding into a larger project had any
measurable effect in the project area compared to the non-project area. More
effective approaches may be required, tailored to the particular needs of women
in the area.
PMID- 10667005
TI - Fatal mumps nephritis and myocarditis.
AB - The case of a 14-year-old girl with fatal interstitial nephritis and myocarditis
as complications of mumps is reported. The illness began with parotitis; renal
symptoms developed within a week. The patient's renal and cardiac status and
clinical course rapidly deteriorated and the outcome was fatal. The post-mortem
renal biopsy sample showed interstitial mononuclear cell infiltration, oedema,
and focal tubular epithelial damage in biopsy material of kidney, confirming the
clinical diagnosis. Myocarditis was determined by electrocardiographic and
echocardiographic findings. Since it has been reported that fatal complications
such as myocarditis, dilated cardiomyopathy, and nephritis may develop in the
course of mumps, the patients with mumps, especially in complicated cases, should
be followed closely because of the severe clinical conditions which may progress.
PMID- 10667006
TI - A child with Neisseria meningitidis endocarditis and Staphylococcus aureus
septicaemia.
PMID- 10667007
TI - Paediatric intensive care in Kuala Lumpur, Malaysia: a developing subspecialty.
AB - Paediatric intensive care in Malaysia is a developing subspecialty with an
increasing number of specialists with a paediatric background being involved in
the care of critically ill children. A part prospective and part retrospective
review of 118 consecutive non-neonatal ventilated patients in University
Hospital, Kuala Lumpur was carried out from 1 June 1995 to 31 December 1996 to
study the clinical epidemiology and outcome in our paediatric intensive case unit
(PICU). The mean age of the patients was 33.9 +/- 6.0 months (median 16 months).
The main mode of admission was emergency (96.6 per cent) with an overall
mortality rate of 42 per cent (50/118). The mean paediatric risk of mortality
(PRISM) score was 20 +/- 0.98 SEM, with 53 per cent of patients having a score of
over 30 per cent. Multiorgan dysfunction (MODS) was identified in 71 per cent of
patients. Admission efficiency (mortality risk > 1 per cent) was 97 per cent.
Standardized mortality rate using PRISM was an acceptable 1.06. The main
diagnostic categories were respiratory (32 per cent), neurology (22 per cent),
haematology-oncology (18 per cent); the aetiology of dysfunction was mainly
infective. Non-survivors were older (29.5 vs. 13.8 months, p < 0.0001), had more
severe illness (mean PRISM score 30 vs. 14, p < 0.0001), were more likely to
develop MODS (96 vs. 53 per cent, p < 0.0001) and required more intervention and
monitoring. Paediatric intensive care in Malaysia differs widely from that in
developed countries in patient characteristics, severity of illness, and care
modalities provided.
PMID- 10667008
TI - Perinatal mortality in twin deliveries in a general hospital in Zambia.
AB - Data from birth records and death certificates were used retrospectively to
determine the risk factors associated with perinatal mortality in twin pregnancy
at Mansa General Hospital between 1 August 1993 and 31 July 1995. A total of 3091
singleton births, 128 sets of twins, and three sets of triplets was recorded
during the study period with a twinning rate of 4 per cent of the total
deliveries. Perinatal mortality in twin gestation was high (141/1000) and
affected mostly the second twin (72 per cent). The main risk factors associated
with perinatal mortality in twin pregnancy were birthweight less than 2000 g (47
per cent), retained second twin (36 per cent), primiparity (28 per cent), fetal
malpresentations (25 per cent), cord anomalies (17 per cent), and home deliveries
(14 per cent). Perinatal deaths in twin pregnancies can be reduced by early
recognition of twin gestation during antenatal visits, prevention of premature
labour, and provision for emergency referral. A woman carrying twins should be
advised to deliver in a well equipped health facility, with adequately trained
health personnel rather than the traditional midwife, in order to minimize
associated hazards.
PMID- 10667009
TI - Survival of childhood acute lymphoblastic leukemia: experience in Chennai.
AB - The object of this study was to evaluate the treatment outcome in children with
acute lymphoblastic leukemia (ALL) in Chennai. The problems inherent in a
developing country which affect outcome are analyzed. The importance of
prognostic factors especially immunotyping is assessed. The period of study was
from June 1991 to December 1995. A total of 135 children were studied. Pre B
CALLA positive (CD10, CD19, HLA, DR) was the dominant immunotype in 75 children
(69 per cent). T-cell ALL was seen in 15 (14 per cent), biphenotype in three (2
per cent), and B in one (0.9 per cent). Seventy children (53 per cent) were
treated with a high risk protocol, 25 (17 per cent) received an intermediate
risk, and 40 patients (30 per cent) received a standard risk protocol. Analyzing
the outcome in 135 children, 34 (27 per cent) had event free survival (EFS) at
the time of analysis; of these 41 per cent had EFS after 2 years of therapy, 31
per cent after 3 years and 18.7 per cent after 4 years (i.e. 1 year after
stopping 3 years of therapy). Fifty-seven children (41 per cent) dropped out; 25
(18 per cent) died due to sepsis. Treatment obstacles included delay in
diagnosis, poor health education and facilities, poor supportive care, and socio
economic problems.
PMID- 10667010
TI - Alpha thalassaemia in Yemeni children with sickle cell disease.
AB - Alpha thalassaemia frequently occurs in several of the Middle Eastern
populations. This study was conducted on 26 sickle cell disease (SCD) patients
from Yemen and 19 normal children (Hb AA) living in Riyadh, Saudi Arabia. Blood
samples were extracted by venepuncture, and haematological and biochemical
parameters were estimated. DNA was extracted from the buffy coat and analysed for
alpha-gene arrangement using Bam HI and Bgl II. The frequency of alpha-gene
deletion in the total Yemeni group (26 SCD + 19 Hb AA) was 0.311 for one alpha
gene deletion (-alpha/alpha alpha) and 0.13 for two alpha-gene deletions (-alpha/
alpha). When separated on the basis of the Hb phenotype the alpha-gene deletion
frequency was significantly higher (-alpha/alpha alpha = 0.346 and -alpha/-alpha
= 0.231) in the SCD patients compared to the normal Hb AA group (-alpha/alpha
alpha = 0.263 and -alpha/-alpha = 0). In the Hb AA group one child had triple
alpha-gene arrangement (alpha alpha alpha/alpha alpha) giving an overall
frequency of triple alpha-gene as 0.022. Haematological parameters showed
variations in the SCD patients with and without alpha-gene deletion. This paper
shows for the first time that alpha-gene deletion occurs in the Yemenis and the
frequency is higher in patients with SCD. Further population-based studies are
required to determine the exact frequency of the different types of alpha
thalassaemias in the overall Yemeni population.
PMID- 10667011
TI - Thyroid hormone studies in protein-energy malnutrition.
PMID- 10667012
TI - Serum vitamin A levels in children with persistent diarrhea and impact on
clinical profile.
PMID- 10667013
TI - Fine needle aspiration cytology in the management of childhood palpable masses:
Ibadan experience.
PMID- 10667014
TI - The health status of rural school children in the Amazon basin of Ecuador.
AB - An assessment of the health status among school children of the Naporuna
ethnicity was conducted in north-eastern Ecuador. Prevalence of protein-energy
malnutrition (PEM), parasitic infections, and pathology was investigated among
511 school children. The overall nutritional status of the school children was
found to be good despite a high prevalence of helminthic infections. The
prevalence of stunting was 1.4 per cent and of wasting 1.8 per cent. Sixty-four
per cent of the children surveyed were found infected with one or more of the
soil-transmitted helminths. In the clinical examination high prevalence of
pterigium (89.2 per cent) was found. Upper respiratory infections (5.2 per cent),
septic skin lesions (4.4 per cent), mycotic otitis (3.8 per cent), tinea (3.4 per
cent) and bronchitis (2 per cent) were the main infectious pathology found.
Likely explanations of these findings are discussed.
PMID- 10667015
TI - [Surgical treatment for bilateral multiple lung cancers].
AB - We reviewed 12 patients with contralateral bronchogenic carcinomas. Seven of them
had metachoronous carcinomas and 5 had synchronous carcinomas. We treated 3
patients with lobectomy on both lungs, and 4 patients with lobectomy and
segmentectomy, 2 patients with lobectomy and wedge resection, 2 patients with
segmentectomy and thoracoscopic wedge resection, and one patient with lobectomy
and ablation on each lung. Two patients who had lobectomy on both lungs were
dead, one of whom of bronchofistula on operation and the other of respiratory
failure 7 years and one month after second operation. The 5-year survival rate in
12 patients was 68.5% after first operation and 82.5% after second operation. We
conclude that lobectomy on both lungs are not recommended because of high
mortality rate and the limited resection should be considered to treat the other
contralateral primary lung cancers. Because the patients with primary lung
cancers have the possibility to suffer from new primary cancers in the different
site of the lung, we need careful follow up of the patients after treatment on
the first lung cancer.
PMID- 10667016
TI - [A successful case of hybrid therapy for the left main trunk and triple coronary
vessel lesions with acute myocardial infarction and cardiogenic shock].
AB - A 86-year-patient who had acute myocardial infarction and critical cardiogenic
shock was diagnosed to have the left main trunk (LMT) and triple vessel disease.
Emergent coronary artery bypass grafting to the left anterior descending artery
was performed using saphenous vein graft without cardiopulmonary bypass through
median sternotomy. On the 41st postoperative day, catheter intervention was
performed to the remaining lesions by stenting of LMT and percutaneous
transluminal coronary angioplasty to the right coronary artery lesions. Tl
scintigraphy showed remarkable reduction of myocardial ischemia. Hybrid therapy
is the effective new strategy for critical cases which cannot be successfully and
securely treated by medical or surgical approach alone.
PMID- 10667017
TI - [Synchronous primary triple cancers including the lung, stomach, and thyroid: a
case report].
AB - A 62-year-old man with synchronous multiple primary cancers involving the lung,
stomach, and thyroid was admitted. Initially the patient's chest X-ray showed an
abnormal shadow in the right middle-lobe indicating lung cancer. During
preoperative examination, gastric cancer of the antrum and angle were detected.
Excisional biopsy of the lymph node in the neck after chest surgery revealed
thyroid cancer. A middle lobectomy with mediastinal lymph node dissection was
performed for lung cancer and the histological diagnosis was moderately
differentiated adenocarcinoma, pT4N2M0, stage IIIB. Gastric cancer was treated by
endoscopic mucosal resection. Considering the relatively better prognosis of
papillary thyroid cancer, we concluded that no further treatment to the thyroid
lesion was necessary. In Japan, according to autopsy reports, triple primary
cancers are gradually increasing. During the periods 1994 to 1996, the incidence
of triple cancers was 0.81% of all autopsy cases reported.
PMID- 10667018
TI - [Transaortic video-assisted thrombectomy in the left ventricular cavity after
acute myocardial infarction].
AB - In recent years much attention has been paid to a minimal invasive surgery even
in the field of cardiac surgery. We have successfully treated a 59 year-old male
who underwent transaortic video-assisted thrombectomy in the left ventricular
cavity following acute myocardial infarction due to occlusion (No. 7) of the left
descending coronary artery (LAD). After the LAD was recanalized by percutaneous
transluminal coronary angioplasty (PTCA) and then stenting, this thrombectomy was
carried out. Following initiation of cardiopulmonary support, thrombus in the
left ventricular apex was safely removed by transaortic endoscopic guidance. This
technique was useful especially for the patient with poor ventricular function
due to acute myocardial infarction because of no left ventriculotomy. Endoscopic
guidance technique is reported in detail.
PMID- 10667020
TI - [Clinical experience using percutaneous cardiopulmonary support system for stent
replacement].
AB - Three cases of tracheal or mein bronchus stenoses were treated using percutaneous
cardiopulmonary support system (PCPS). Case 1 was a 63-year-old male admitted for
dyspnea due to stenotic trachea with primary lung cancer invasion. YAG-laser
operation and Dynamic stent was inserted to the trachea using PCPS. Case 2 was a
74-year-old male admitted for dyspnea due to stenotic right mein bronchus with
primary lung cancer invasion. Dumon Y stent was inserted to the right mein
bronchus using PCPS. Case 3 was 57-year-old male admitted for dyspnea due to
stenotic trachea and occluded left mein bronchus with ischemic change after
primary esophageal cancer operation. Dynamic stent was inserted to the trachea
and left mein bronchus using PCPS. Tracheal and mein bronchus stenoses the
trachea of all was dilated after placement of stent. These three cases had no
complications during or after these treatment. These results indicated that using
PCPS was a very useful, powerful and satisfactory method in the treatment of
tracheal or mein bronchus stenoses during the lack of lung ventilation.
PMID- 10667019
TI - [Coronary artery bypass grafting for a patient with bronchial asthma seceeded
from cardiopulmonary bypass by additional bypass for spasm of radial artery
graft: a case report].
AB - A 78-year-old male who had a bronchial asthma underwent coronary artery bypass
grafting (CABG) using the left internal thoracic artery and the radial artery.
The patient could not be weaned from the cardiopulmonary bypass because the
radial artery which anastomosed to the obtuse marginal artery (OM) had a spasm
after CABG. An additional bypass using a long saphenous vein to OM was carried
out immediately. It brought a weaning from cardiopulmonary bypass. If the cardiac
function after CABG is insufficient in patients with bronchial asthma, CABG must
be re-done immediately, considering that they cause the arterial spasm more than
patients without bronchial asthma.
PMID- 10667021
TI - [The effects of intravenous milrinone for the patient undergoing CABG].
AB - The hemodynamic effects of intravenous infusion of milrinone were evaluated in 25
patients undergoing CABG using an internal mammary artery graft. Milrinone was
administered to 9 patients at the time of weaning from cardiopulmonary bypass, at
a dosage of 3 to 5 micrograms/kg/min. Postoperative cardiac function was compared
in this group versus the other 17 patients who were treated without milrinone. We
determined such parameters as cardiac index, wedge pressure and mean pulmonary
pressure. Our findings did not show any significant difference between the 2
groups. We also studied a subject of low-output patients (EF < 0.5). In the
patients with low-cardiac output, the use of milrinone in addition to standard
postoperative administration of low-dose dopamine reduced mean pulmonary pressure
and wedge pressure. Thus, milrinone not only improved the left ventricular
function, but also expanded the pulmonary vascular bed.
PMID- 10667022
TI - [Dose the serum brain natriuretic peptide (BNP) level after open heart surgery
reflect myocardial protection?].
AB - This clinical study was conducted to determine whether the serum BNP level after
open heart surgery reflects myocardial protection. The levels of BNP and CPK-MB
were measured before and after 12 hours of cardiopulmonary bypass, then 1, 3, and
6 days after open heart surgery, and the relationship between the maximum levels
of BNP and the CPK-MB after open heart surgery was examined. The patients were
divided into two groups according to whether or not the maximum CPK MB was more
than 100 IU/l after open heart surgery. A significant relationship between the
maximum BNP and the maximum CPK-MB after open heart surgery was observed (p =
0.013). Moreover, the BNP was significantly increased in the group of patients
with a maximum CPK-MB > or = 100 IU/l, compared to that in those with a maximum
CPK-MB < 100 IU/l, 12 hours 1 day, and 6 days after open heart surgery (p <
0.01). These findings indicate that the serum level of BNP after open heart
surgery can reflect myocardial protection.
PMID- 10667023
TI - [Surgery for intrathoracic recurrence of non-small cell lung cancer].
AB - In this study, we defined a solitary lung nodle in the same histology which could
be traced its' origin from carcinoma in situ or was found over than two years'
follow up as a second primary lung cancer. These cases were excluded. Eighteen
cases underwent second surgery for intrathoracic recurrence. Fourteen cases were
male and four cases were female. Their ages ranged from 23 to 75 (average 59.6)
years. The histology were adenocarcinoma in 9 cases, squamouscarcinoma in 7,
adenosquamous carcinoma in 1, large cell carcinoma in 1. The initial surgical
procedures were lobectomy in 17, partial resection in 1. The initial stage were I
in 13, II in 2, IIIA in 1. Pulmonary recurrence were found in 10, bronchial stump
recurrence were found in 4, pulmonary hilus lymph node recurrence were found in
2, mediastinal lymph node recurrence were found in 2, pulmonary stump recurrence
was found in 1. The second surgical procedures were completion pneumonectomy in
7, completion lobectomy in 1, lobectomy with segmentectomy in 1, segmentectomy or
partial resection in 7, mediastinal dissection in 2. The overall 5-year survival
rate of the patients with recurrence after reoperation was 31.8%. An aggressive
surgical approach for recurrent lung cancer should be recommended.
PMID- 10667024
TI - [Late results of SJM and CM valves in bentall procedure].
AB - Recently, Bentall procedure is commonly performed for annuloaortic ectasia with
aortic regurgitation or dissecting aneurysm. And the operative results are
improving. In this study, we evaluated results of the St. Jude Medical (SJM) and
Carbomedics (CM) valves which were used in this procedure. From 1979 to 1994, 87
SJM valves and 22 CM valves were implanted in the aortic position of Bentall
procedure. Total follow-up was 528.6 years in the SJM group and 56.5 years in the
CM group. According to the Kaplan-Meier actuarial method and the Cox-Mantel
statistical analysis, actuarial survival, thromboembolism free rate, reoperation
free rate, event free rate were not different between the SJM and CM groups.
These results suggest that, current selection of the SJM and CM valves would be
acceptable in Bentall procedure.
PMID- 10667025
TI - [Ineffective and recurrent cases of thoracoscopic sympathectomy for hyperhidrosis
and intractable pain].
AB - We reported the cases of thoracoscopic sympathectomy, that is, six cases of
hyperhidrosis, three of post herpetic neuralgia, and four of reflex sympathetic
dystrophy, including recurrent or incompletely resected or ineffective ones.
Recently this procedure for hyperhidrosis had been performed frequently because
of its effectiveness, less pain, early discharge and cosmetic aspect. For an
ineffective case of hyperhidrosis abdominal respiration which emphasized the
exhalation and using an upper abdomen decreased the sweating. The balance of
autonomic nerve system, toward parasympathetic dominant, was thought to be
improved by conscious respiration. The decrease of sweating right after the
operation in a case of incomplete resection indicated that intraoperative
maneuver could restrict the sympathetic nerve. This procedure for a pain control
could be less effective than that for hyperhidrosis, so an adequate preoperative
informed consent was thought to be necessary.
PMID- 10667026
TI - [An elderly case of ruptured aortic arch aneurysm with hemorrhagic cardiac
tamponade].
AB - We reported a case of successful aortic arch replacement using selective cerebral
perfusion for ruptured distal aortic arch aneurysm (DAAA) with cardiac tamponade.
A 80-year-old man who had preoperative episode of severe chest pain. Computed
tomography showed saccular DAAA and pericardial effusion. He was diagnosed as
ruptured DAAA with hemorrhagic cardiac tamponade. We performed urgent graft
replacement of the aortic arch using selective cerebral perfusion.
Postoperatively he had no complication. Thirty days after the operation he was
discharged from the hospital and he is now leading a normal life.
PMID- 10667027
TI - [Blunt rupture of the intrapericardial inferior vena cava: report of two cases].
AB - Blunt rupture of the intrapericardial inferior vena cava is rare. Our experience
in recent two cases is presented. Case 1: A 52-year-old male was admitted
following a traffic accident. Chest CT demonstrated cardiac tamponade and
mediastinal hematoma. Ruptures of the right and left atria across the caudal
aspect of the atrial septum, and a separate laceration of intrapericardial IVC
were found in the emergency operation. Case 2: A 35-year-old male jumped from the
fourth floor of a building. Chest CT revealed descending aortic rupture and the
patient was taken to surgery. He died of massive hemorrhage from the aortic
rupture. Exploration revealed a rupture of intrapericardial IVC. Recent
literatures were reviewed and the mechanism of IVC rupture is discussed.
PMID- 10667028
TI - [Ventricular septal defect with pulmonary hypertension and concomitant left
atrial myxoma in elder patient: a successful surgical case report].
AB - A 70-year-old man was admitted with syncope attack on exertion. Ventricular
septal defect with pulmonary hypertension and left atrial myxoma were confirmed
by ultrasonography and cardiac catheterization. Preoperative Pp/Ps was 0.95 and
pulmonary vascular resistance was 16 units. Pulmonary vascular resistance
decreased to 9.6 units by the administration of Isoproterenol and decreased to
8.5 units with PGE1. Patch closure of VSD and excision of left atrial myxoma were
performed simultaneously. The patient recovered completely, although he suffered
from pneumonia and jaundice due to liver congestion postoperatively. Cardiac
catheterization before discharge revealed Pp/Ps 0.38 and PVR 10.1 units.
PMID- 10667029
TI - [A case report of primary hemangiopericytoma of the chest wall].
AB - A 35-year-male was found to have an abnormal shadow with an extrapleural sign
located in the right lower lung field by a chest X-ray. Chest CT revealed a well
demarcated tumor in the chest wall adjacent to the 4th rib. Chest MRI showed that
the tumor contained punctate or linear low-intensity areas, which were considered
to be small blood vessels. A diagnosis of hemangiopericytoma was established by
percutaneous needle biopsy. Under the definite diagnosis, extended resection of
the chest wall was performed to remove the tumor with a surgical margin of more
than 5 cm, corresponding to surgery for other malignant soft-tissue neoplasmas.
Hemangiopericytomas rarely arise in the chest wall, although they can be found in
any region which contains pericytes. Preoperative definite diagnoses of
hemangiopericytoma have rarely been reported. However, preoperative diagnosis is
an important factor in deciding the operative procedure for hemangiopericytoma.
It has been reported that hemangiopericytomas show local recurrences and distant
metastases, although they are histologically benign. We consider that
hemangiopericytomas in the chest wall should be treated with extensive resection
corresponding to surgery for other malignant soft-tissue neoplasmas.
PMID- 10667030
TI - [A case of mediastinal mature teratoma accompanying elevated CA 19-9 and CEA in
the cystic fluid].
AB - Fourteen year old female visited our hospital suffering from anterior chest pain.
Chest CT revealed anterior mediastinal mass which had multiple cystic lesions,
8.5 x 7.0 x 5.5 cm in size. Tumor extirpation had performed by median sternotomy
and pathological diagnosis was mature teratoma. CA 19-9 and CEA in the cystic
fluid had elevated 32,790 U/ml and 768 ng/ml, respectively.
PMID- 10667031
TI - [A case of teratoma in both the mediastinum and the intrapulmonary system].
AB - A rare case of mature teratoma in both the mediastinum and the intrapulmonary
system is presented. A 30-year-old male was admitted to our hospital due to tumor
masses in the mediastinum and the left lung. We performed mediastinal tumor
resection and left upper partial lobectomy. Neither tumor communicated with each
other. Pathological findings revealed teratoma in the mediastinal lymph node and
the intrapulmonary system including no malignant cells in either tumor. In this
case, because metastasis and perforation were negative, we proposed that both
tumors occurred at the same time in the early embryo.
PMID- 10667032
TI - [Postoperative interstitial pneumonia: 2 cases after lobectomy].
AB - Two patients with postoperative interstitial pneumonia are reported. Preoperative
diagnosis was primary lung cancer without idiopathic interstitial pneumonia
(IIP). Within one week after operation acute interstitial pneumonia (AIP)
occurred on the nonoperated side and developed. Steroid therapy was performed but
one was dead. AIP is a fatal complication after pulmonary resection and steroid
therapy may be useful in some cases of postoperative AIP.
PMID- 10667033
TI - Perioperative assessment; what is the question?
PMID- 10667034
TI - Preoperative screening and preoperative medicine: a new challenge for
anesthesiology and internal medicine.
PMID- 10667035
TI - The value of peri-operative consultation on a general surgical ward by the
internist.
AB - BACKGROUND: Medical peri-operative consultation plays an important role in the
practice of the internist. It represents 13-33% of the total consultation done by
the internist. The value of preoperative consultation by the internist is still
unclear and the place of the consultations is under discussion. METHODS:
Consecutive medical consultations--by internist-intensivists from the surgical
ICU--of 408 patients in the department of Surgery of the University Hospital
Groningen were retrospectively analyzed, with specific attention to the
consultation request, the consultation report and the outcome of the
consultation. RESULTS: The main problems were cardiac (34%) or pulmonary (20%).
In 78% well defined questions about the patients were asked and in 29% of the
preoperative requests, the requesting surgeon asked specific advice about
diagnosis and management. In 49% the requesting physician asked for an
'evaluation' of the patients. Of all consultations 271 (67%) were preoperative
consultations. In 12% the findings of the preoperative consultation had a
significant impact on the course of the patient, whereas in 7% of the
preoperative requests the operation was postponed. The consulting internist
recommended in 2% to cancel the operation for this admission, which was shared by
the surgeon and anesthesiologist. In 10% of all cases new diseases or processes
were diagnosed, or were found not to be treated adequately before consultation,
so the diagnosis or management was changed. CONCLUSIONS: Our data show that (semi
) elective consultations by internists at the department of Surgery, on
indication of the surgeon, changes the course of a significant percentage of
patients. (See Editorials p. 1 and p. 4).
PMID- 10667036
TI - Clinical and pharmacological aspects of accidental triamcinolone acetonide
overdosage: a case study.
AB - Local administration of corticosteroids for rheumatic diseases have had a long
history of effective and well-tolerated use. We report here the pharmacodynamics
and pharmacokinetics of an accidental triamcinolone acetonide (TCA) overdose. The
presented patient was treated with 200 mg TCA and developed Cushing's syndrome 6
weeks later (cortisol and ACTH concentrations were below limits of detection, TCA
concentrations were > 3 micrograms/l). Because of her severe symptoms,
mifepristone was administered for a period of 19 days. Cortisol concentrations
became detectable 2 days after initiation of mifepristone treatment and
persisted, being detectable for a period of at least a week after cessation of
the drug. Twenty days after cessation, cortisol concentrations were undetectable
again. Cushing's syndrome persisted more than 6 months while TCA concentrations
remained detectable for at least 80 days. Based on plasma TCA concentrations in
our patient, we calculated a terminal half-life of TCA of 33 days as opposed to 5
days observed after intra-articular administration of a therapeutic dose of 40 mg
TCA. We conclude that after an accidental overdose in this patient, body TCA
disappearance was strongly prolonged due to a very slow (absorption) half-life of
the drug in comparison to a therapeutic dose. This finding is explained by a
'flap-flop phenomenon' where drug absorption is the rate-limiting step of overall
drug disposition. Caution is, therefore, needed to prevent undesired accumulation
of TCA that may lead to protracted Cushing's syndrome.
PMID- 10667037
TI - Inflammatory pseudotumor of the fossa pterygopalatina: diagnosis and treatment.
AB - Pseudotumor is a term used to describe a space-occupying inflammatory lesion of
unknown etiology that clinically simulates a neoplastic process. Pseudotumors of
the fossa pterygopalatina and fossa infratemporalis are very rare. In this paper,
we describe a patient who developed a pseudotumor in the left fossa
pterygopalatina, secondary to an unclassified autoimmune disease, which caused
progressive left-sided facialdynia and swelling. The tumor was detected with
somatostatin receptor scintigraphy. The lesion was refractory to steroids, also
in combination with azathioprine, as well as to surgical intervention. An
excellent clinical response was observed after cyclosporine was added. This case
is presented here in order to draw attention to the use of somatostatin receptor
scintigraphy as a diagnostic tool in visualizing pseudotumors and to document a
case that responded excellently to treatment with a combination of low-dose
cyclosporine and steroids.
PMID- 10667038
TI - A homozygous M694V mutation of the MEFV gene in a patient with periodic fever and
thoracic pain.
AB - A Turkish patient with episodic fever and thoracic pain is described in whom a
homozygous M694V mutation of the MEFV gene confirmed the clinical diagnosis of
familial Mediterranean fever. The role of DNA analysis is discussed with respect
to understanding the pathogenesis of the fever and assessing the risk of
amyloidosis in specific mutations of the MEFV gene.
PMID- 10667039
TI - Chylothorax.
AB - Chylothorax is defined as an accumulation of chyle in the pleural space caused by
disruption of the thoracic duct or one of its major divisions. Chyle has a high
content of triglycerides. The odorless fluid is turbid and milky due to the
presence of fat containing particles, the chylomicrons. The etiology of
chylothorax can be divided into four major categories: tumor, trauma, idiopathic
and miscellaneous. Although chylothorax is uncommon, it is a serious and
potentially hazardous disorder. Loss of chyle leads to metabolic disturbances,
malnutrition and immunodeficiency. Treatment consists of treatment of the
underlying disease, conservative treatment (medium chain triglyceride diet,
parenteral nutrition) or surgical intervention. Appropriate timing of surgical
intervention is essential. Since the ligation of the thoracic duct can be
performed during thoracoscopy, this minimal interventional technique is the
procedure of choice when conservative treatment fails.
PMID- 10667040
TI - [Image of the month. Isolated appendicular polyposis].
PMID- 10667041
TI - [How I treat ... idiopathic hyperhidrosis].
AB - Palmo-plantar and/or axillary idiopathic hyperhidrosis is unpleasant and
sometimes invalidating. Its malodorous variant which is due to biodegradation by
bacterias is called bromhidrosis. According to the severity of the condition,
several therapies exist including psychotherapy, various topical products,
iontophoresis, botulinic toxin injections and thoracic sympathectomy.
PMID- 10667042
TI - [Clinical case of the month. Cerebral salt wasting syndrome: report of a case].
AB - A 75 year old woman was found to have a posterior cerebellar lesion which after
surgical removal was shown to be a meningioma. Her postoperative course was
complicated by a MRSA meningitis and on day 23 after resection, a polyuria up to
11.7 1/24 h became apparent. The diagnosis of cerebral wasting syndrome (CSWS)
was made based on biological and clinical features such as an excessive
natriuresis (143 mmol/l) resulting in hyponatremia (130 mmol/l) and an osmolarity
higher in urine than in blood. A low central venous pressure and a low wedge
pressure confirming a volumic depletion indicated the diagnosis of CSWS. This
syndrome has marked similarities with the Inappropriate Secretion of Antidiuretic
Hormone Syndrome (SIADH) in terms of biological finding with regards to clinical
context and presentation. Without an adequate assessment, a patient with CSWS may
be misdiagnosed as SIADH. However recognition is important, as water restriction
which is part of SIADH treatment, is detrimental to patients with CSWS and can
possibly be lethal.
PMID- 10667043
TI - [Medication compliance].
AB - Compliance is defined as the extent to which a patient's behaviour coincides with
medical or health advice. Medication compliance seems to be rather low as 30 to
60% of no or poor adherence to medical recommendation have been reported.
Numerous factors may influence medication compliance among which patient's
characteristics, disease particularities, drug treatment modalities or
physician's attitudes. The consequences of medication non-compliance may not only
be dangerous for patient's health, but also dramatically increase the financial
cost for public health services. Thus, all energies should be devoted to improve
drug compliance, including treatment optimization and simplification, patient's
information and education, use of practical means that facilitate adherence to
medical recommendation, the patient being responsible for his/her treatment.
PMID- 10667044
TI - [Anatomic-clinica dilemma. Case report of renal cell carcinoma].
AB - The authors report the case of a patient with a history of hypertension and
multiple intracerebral hemorrhages who was found at post mortem examination to
have a renal cell carcinoma. The relationship between renal carcinoma and
hypertensive intracerebral hemorrhages is discussed.
PMID- 10667045
TI - [Winter skin diseases].
AB - Winter climate is prone to induce cutaneous and systemic alterations mediated by
cold. Xerosis due to the impairment of the desquamation process is not rare on
the limbs. Chilbain results from reversible alterations of the dermal
vasculature. Cold panniculitis is the consequence of lipid crystallization within
adipocytes. More dramatic issues occur when cold exposure extends beyond skin.
They are represented by frostbite and body hypothermia. Intensity and duration of
cold exposure combined with wind speed, altitude and environmental hygrometric
value govern the potential type of low temperature-dependent pathology.
Ultraviolet irradiation can also induce cutaneous lesions during winter time.
PMID- 10667046
TI - [New players in the physiopathology of water metabolism: the aquaporins].
AB - Aquaporins are transmembrane proteins mediating water transport across plasma
membrane of animal, vegetal or bacterial cells. Among the ten aquaporins known in
mammals, six are located in kidney and take part in urine concentration. AQP2 is
vasopressin regulated, it is the only family member to be implicated in human
pathology, such as nephrogenic diabetes insipidus, congestive heart failure,
hepatic cirrhosis, nephrotic syndrome or SIADH. Aquaporins are expressed in a
wide variety of tissues, such as brain or gastrointestinal tractus, and suggest a
role in water tissue exchange, but their real function is still not define. To
know the physiological impact of aquaporins, AQP1, AQP3, AQP4 and AQP5 knockout
mice have been created and their phenotype analysed.
PMID- 10667047
TI - [Surgery, radiotherapy or hormonal therapy in the treatment of prostate cancer].
AB - Prostatic cancer (PC) became the first diagnosed cancer in western men and is the
second leading cause of cancer death in men. Wide utilisation of serum PSA and
free PSA measurements, identifies patients requiring transrectalultrasonography
(TRUS) and TRUS guided biopsies. Most prostatic cancers diagnosed today are
locally limited and may be treated by radical surgery or radiotherapy. In case of
disseminated disease, hormonal manipulations remain the treatment of choice. In
that field, many new drugs have been designed to allow medical castration with
less complications, especially regarding sexual potency.
PMID- 10667048
TI - [Treatment of border-line dilatation of the ascending aorta using the Robicsek
intervention].
AB - The technique and the results of the external contention of the dilated ascending
aorta by the application of an external Dacron graft are reported. This
technique, without replacing the usual graft interposition, can efficiently and
expeditiously treat borderline dilatation of the ascending aorta, as frequently
encountered in aortic valve disease. If the sinotubular junction is not dilated,
this technique may stop the aneurysmal evolution of the ascending aorta.
PMID- 10667049
TI - [Results of artificial sphincter for the treatment of sphincter incontinence].
AB - 47 patients were treated since 1987 by implantation of an artificial sphincter.
The majority of female patients were operated for bladder neck hypermotility. In
the male population, incontinence was mostly a complication of prostatic surgery.
The indication, preoperatory assessment, surgical techniques and results are
discussed. During a mean follow-up of 38 months, 92.9% of females remained
perfectly continent and results were good in 76.7% of males. The results are
similar to those reported in the literature.
PMID- 10667050
TI - [How I assess ... home glycemic control in diabetic patients].
AB - Self blood glucose monitoring is now a key element in the management of diabetic
patients. However, in order to improve overall blood glucose control, self
monitoring should lead to self-management. This implies that the patient modifies
his/her behaviour (diet, exercise, oral antidiabetic agents, insulin doses) to
ameliorate the metabolic status according to his/her blood glucose measurements.
While the place of home blood glucose monitoring is rather well defined in type 1
diabetes, it remains more controversial in type 2 diabetes.
PMID- 10667051
TI - [Clinical study of the month. Does chronic sleep deprivation predispose to
metabolic syndrome?].
AB - According to a recent experimental study published in the Lancet, sleep debt,
frequently imposed by the life habits of industrialized countries, results in
profound metabolic (impaired glucose tolerance) and endocrine (increased
sympathetic activity and evening cortisol levels) alterations, which mimic those
of normal ageing and may have pathophysiological consequences in the long term.
Another study recently published in the International Journal of Obesity
demonstrated a significant positive relationship between the duration of shift
work and body mass index or waist to hip ratio, a marker of visceral adiposity.
One may thus hypothesize that chronic sleep deprivation could predispose to the
metabolic syndrome and increase the cardiovascular risk.
PMID- 10667052
TI - [The incineration of waste: a poisonous debate?].
PMID- 10667053
TI - [Are sanitation services complaints an indicator of quality of care?].
AB - A retrospective analysis of 211 consecutive complaints treated at the Direction
of Health and Social Assistance of Paris was undertaken in order to specify the
nature of the complaints and to evaluate their pertinence as an indicator of
quality of care. The majority of complaints concern public and private health
establishments, in particular surgery and psychiatric services. Although the
study confirms the dysfunctioning of the organisation of services and also of
therapeutic methods and medical treatments, the evaluation of iatrogenic risks
and their avoidable nature is difficult and requires precise instruction.
Complaints seem to be a neglected indicator of quality, yet they concern
information that is accessible and could, if used with other information, be a
first milestone in the vigilance of medical treatments.
PMID- 10667054
TI - [Situation and role of local structures of hospital ethics: s survey of Hospital
Public Care in Paris].
AB - This article presents the main results of a survey carried out among the local
structures for hospital ethics of the Public Assistance sector of the Hospitals
of Paris. The results show that the situation of these structures has completely
transformed itself since the law of 1988 on human research. Only four ethics
committees subsist out of the 16 university-hospital committees that existed in
1991. Seven new structures have been created since 1994, which are open to all
categories of personnel and within which doctors are a minority. The four ethics
committees provide almost no decision making opinions anymore and are, like the
new groups, fora for discussion, reflection, or even information on issues of
hospital ethics. Almost none of these structures has an official mission. This
situation presents the question of the role that a local ethics structure can
hold within a hospital.
PMID- 10667055
TI - [Feasibility of drug use detection among individuals 15-25 years of age in
community medicine].
AB - The objective of this work is to study the feasibility of the detection of drug
use or misused substances during a visit with a municipal doctor, and to describe
the interrogatory strategies used spontaneously by doctors. One tenth of the
clients aged 15-25 of the 26 participating doctors, (the majority of them men
visiting the doctor for a psychological problem), showed a "warning" signal and
were detected. The doctors often chose to approach the problem of drugs directly
and detected usage in two-thirds of the cases. Cannabis was most often concerned,
but the use of psychotropic drugs with alcohol was the case in one-third of the
subjects interrogated. On the other hand, a certain frustration was felt by the
doctors because of the difficulty of approaching the root problems and of
acquiring psychotherapeutic monitoring.
PMID- 10667056
TI - [Contributions to the sociologic analysis of the impact of sickle cell disease on
families from Northern Tunisia].
AB - The improvement of the conditions of care and quality of life of people living
with drepanocytosis now constitutes a major concern of health authorities and
voluntary groups (associations of sick people and their parents). In order to
examine the conditions and methods of care for children living with
drepanocytosis in the Bizerte region of Northern Tunisia and to understand the
problems and difficulties experienced by them and their families in their daily
lives, an anthropological study was carried out in the region between January 16
and February 12, 1997. Thirty-three interviews were carried out with families of
infected children. The interviews were semi-directive using a pre-established
protocol (interview guide). Thirty interviews were then analysed. A multitude of
information concerning various medical and psycho-social aspects of
drepanocytosis in the region were revealed. The data were regrouped into the
following categories: circumstances of discovering the illness; explicative model
of the illness as perceived by the people interviewed; conditions and methods of
care of the sick child; degree of satisfaction with the health care system;
psychological profile of the children interviewed; educational level of the
children interviewed; repercussions the illness has on the family; impact of the
illness on household budget; suggestions and comments of the people interviewed.
In light of the information collected, various actions have been proposed with
the goal of improving the conditions of care and quality of life of people living
with drepanocytosis in the region.
PMID- 10667057
TI - [Occupational hazards in the Moroccan craft sector and proposal for occupational
health services].
AB - The absence of occupational health services, the numerous occupational hazards
and the high number of people working in the handicraft sector have sparked this
study. Descriptive, cross-sectional epidemiological studies were carried out
throughout 1996 for different artisan activities: iron-work, jewellery making,
rug making, tannery, "zellige", pottery, and woodworking. The study included 449
artisans and consisted of an analysis of work conditions, a medico-social
questionnaire, a clinical examination and among certain artisans, a biological
check-up, a respiratory check-up (thoracic x-ray and lung function testing), and
a toxicological check-up. Poor work conditions and the absence of any technical
protection (collective or individual) are common to all the workshops visited.
Multiple risks as well as various and frequent pathologies were observed for all
the artisan activities. The most common ailments are those linked to posture and
musculo-skeletal problems (67.6%), oral (58.2%), ocular (46.9%), dermatological
(35.7%), ear/nose/throat (35.3%), respiratory (31.1%), digestive (21.1%) and
neurological (20.7%). Often the same artisan showed several simultaneous
conditions linked to work. The legislative texts related to occupational health
and safety are many and dispersed, and would profit by being updated and
regrouped within a work code which would make them easier to consult and would
allow all partners in the social sector to get to know them. In addition, this
legislation which has been strengthened, is unfortunately not enforced. We should
support every initiative focused on developing the prevention of occupational
hazards and the spirit of safety within artisan workshops. The concern for
occupational risks within the artisan milieu owes its importance to their
abundance, the diversity of the professions involved, and the number of different
risks to which artisans are exposed. The role of a worksite doctor is therefore
considerable, and his field of intervention in this milieu is vast. The broader
goal of occupational health services is to protect and improve the physical,
mental, and social well-being of its workers; it is natural that these services
should give more attention to general health promotion (vaccinations, health
education...). Given that the artisan sector is organised around its structures
of production, it seems urgent to introduce medical coverage and to improve
health and safety conditions within the sector.
PMID- 10667058
TI - [Palliative care at a university hospital center: physicians' opinions (1992
1996)].
AB - OBJECTIVE: To evaluate the evolution of doctors' opinions in a university
hospital centre concerning care for terminally ill patients following the
creation of a Mobile Palliative Care Unit (MPCU). METHODS: In the relevant
services of a university hospital in Paris (1095 beds), (1) the first survey in
1992 included interviews with 17 doctors; (2) the second interview was carried
out in 1996 by self questionnaire among 55 doctors. RESULTS: (1) The doctors
stressed their wishes to accompany their patients "until the end" and stressed
the role of the patients' family (support system) and of nurses. They indicated
their wishes especially for training then for the creation of a MPCU. (2) The
MPCU, solicited by 87% of doctors, teaches palliative care and provides
therapeutic, psychological and relational assistance, judged as very
satisfactory, to carers and families. The doctors would like to see these
activities sustained.
PMID- 10667059
TI - [Physicians' opinions and practices on the use of medical referrals at
hospitals].
AB - This work aims to take stock of the actual utilisation of medical standards
(references), through a study of opinions and practices of the medical managers
working in the clinical services of a university hospital centre. A survey
through interviews was proposed to 103 medical managers, 101 responded to the
questionnaire (38 Unit directors and 63 directors of "UF" units). Medical
standards are used essentially as a teaching aid by 80% of doctors. Some of them
(48%) make them available to prescribing doctors in the unit, and for 36% there
exists an informational procedure for new residents. Evaluation studies
concerning the implementation of medical standards remain rare (7 studies).
Medical standards appear to be more useful for improving quality of care (90%)
then for controlling health expenditures (72%). The majority of medical managers
(72%) consider that certain standards should be opposable to hospitals. The
medical managers of the university hospital centre are in favour of developing
standards of clinical practice.
PMID- 10667060
TI - [Effectiveness of a program for improving drug prescriptions and hospitalization
reporting at a university hospital].
AB - OBJECTIVES: To evaluate the effectiveness of a method for improving the quality
of care applied to the formulation of medical prescriptions and to the release of
hospitalisation reports. The actions comprised the diffusion of results of audits
and recommendations of good practice. METHODS: For each of the 41 services, 30
visits from 1996 were selected at random. 3289 prescriptions and 1067
correspondence files were analyzed. The results were compared to those obtained
from the previous two years. RESULTS: Patient identification was complete in 44%
of prescriptions, the identification of the prescribing doctor and his signature
were present in 62% and 19% of cases respectively. 37% of medicines included all
information. 7 indicators out of 12 for the quality of prescriptions improved (p
< 0.0001). Files were found for 83% of hospital visits and 56% were sent
(released) within a week. The practitioner was identified in 79% of cases, the
main diagnosis in 96% and the treatment in 65% of cases. Five out of nine
indicators of the quality of correspondence improved (p < 0.01). For each theme,
the number of indicators improving was similar (p > 0.05). The services that
improved for one theme didn't necessarily improve for the second (p > 0.05).
DISCUSSION: The evaluation of the programme, based on a strategy of quality
assurance, shows modest progress. Given that the improvement of two themes for a
given service are not correlated, the programme appears to sensitise
professionals at an individual level rather than collectively. However, this
programme is an important step for introducing a mode of continued improvement of
quality.
PMID- 10667062
TI - [The internet and public health: access to information].
PMID- 10667061
TI - [Lack of communications between general medicine and the mental health sector].
AB - Mental health problems today account for a rising number of visits to general
practitioners, which require collaboration between general practitioners and
psychiatrists. A KAP study (Knowledge, Attitudes, Practice) was carried out among
general practitioners of three towns in the "Meurthe et Moselle" region, in the
common territory shared by both a child and an adult psychiatric sector. Twenty
three doctors participated in the study. General practitioners know the different
psychiatric structures but they do not know their areas of speciality or how they
are organised. All recognise the high frequency of mental health problems among
their patients, the most frequent being depressive pathologies. They have a
negative image of the sector which is perceived as a complex "world" from which
they feel excluded as soon as they refer a patient because of the difficulty they
have in communicating with psychiatrists.
PMID- 10667063
TI - [When ideology is a barrier to violence prevention].
PMID- 10667064
TI - [Introduction to molecular and cellular biology of chloroplast biogenesis].
PMID- 10667065
TI - [Structure and function of the plastid-dividing apparatus].
PMID- 10667066
TI - [Molecular organization and dynamism of chloroplast nucleoid, a eukaryo
prokaryotic hybrid].
PMID- 10667067
TI - [Transcriptional regulation in the chloroplast: mechanisms of coordinated
expression of photosynthesis genes].
PMID- 10667068
TI - [Post-transcriptional regulation of chloroplast gene expression].
PMID- 10667069
TI - [Protein transport of chloroplast proteins].
PMID- 10667070
TI - [Chloroplast function and plant development].
PMID- 10667071
TI - [Progressing molecular cell biology in bacteria: chromosome partitioning and cell
division].
PMID- 10667072
TI - [The role of paraxial protocadherin in morphogenetic cell movement during
gastrulation].
PMID- 10667073
TI - [Imaging and manipulation of DNA molecules using scanning tunneling microscopy].
PMID- 10667074
TI - [Deblocking aminopeptidase from Pyrococcus furiosus and its application for
proteomics].
PMID- 10667075
TI - [Check-up and screening].
PMID- 10667076
TI - [Check-up examinations from the cardiologic viewpoint].
AB - The concept of the primary prevention of coronary disease is certainly widely
accepted today and supports check-up visits of apparently healthy persons. The
goals of check-up's viewed by the cardiologist are the detection of coronary risk
factors and the identification of asymptomatic patients with coronary disease to
initial preventive measures. In some instances, a personal health problem forces
the patient to a check-up visit. The major coronary risk factors of heredity,
cigarette-smoking, hypercholesteremia, hypertension can be detected by taking the
history, performing a physical examination and a blood-sampling for cholesterol.
Additional investigations such as an ECG or an exercise-test are only indicated
in symptomatic patients or in persons at high coronary risk.
PMID- 10667077
TI - [Screening, diagnosis and management of diabetes mellitus and diabetic
complications].
AB - Diabetes mellitus comprises a group of metabolic disturbances that are
characterized by hyperglycemia. In 1997 the American Diabetes Association (ADA)
proposed new criteria for the diagnosis and classification of diabetes mellitus,
which was also adopted by WHO. Although the criteria is the same, the ADA puts
emphasis on the use of the fasting plasma glucose (FPG) for screening and
diagnosis, whereas WHO maintains the use of the OGTT and recommends the FPG only
if an OGTT can not be performed. Different pathogenetic processes are involved in
the development of diabetes ranging from autoimmune destruction of beta-cells
resulting in an absolute insulin deficiency to insulin with a defect on insulin
secretion. The new classification is based on the etiology of the disease.
Diabetes is classified into one of four categories: Type-1, type-2 Diabetes
mellitus, specific forms of diabetes, and gestational diabetes. For screening and
diagnosis FPG or the two hour value after the OGTT can be used. Glycosylated
hemoglobin is not suitable for screening and diagnosis of diabetes despite some
contradictory statements. For many decades clear evidence was missing that
chronic hyperglycemia caused diabetic late complications; complications including
dysfunction or failure of several organ systems, in particular eyes, kidneys,
nerves, and the cardiovascular system. The results of two large prospective
trials--the Diabetes Control and Complications Trial (DCCT; 1993) and the United
Kingdom Prospective Study (UKPDS; 1998)--that were recently published provided
the final proof that normoglycemia prevents or delays the progression of these
late complications. Due to the insidious nature of these complications they are
often not diagnosed and have to be looked for in each patients with diabetes and
have to be controlled regularly. Based on the results of the UKPDS and other
studies, evidence based therapeutic goals could be defined. Multifactorial
interventions with increased physical activity, cessation of smoking, aspirin
treatment, lowering of HbA1c, blood pressure, and lipids in patients with type 2
diabetes have been proven to drastically reduce the risk of developing diabetic
nephropathy or cardiovascular complications drastically. We recommend the
following treatment strategy for patients with type 2 diabetes in clinical
practice: 1) Treatment should be individualized. 2) Treatment should be started
step by step to document efficacy of treatment and compliance of patients. 3)
Plasma glucose and blood pressure should be normalized in all patients with type
2 diabetes (up to an age of 70 years), since there are no threshold values for
HbA1c and blood pressure. 4) Therapeutic goals should be checked every three to
six months. 5) In the case that therapeutic goals can not be met, treatment
should be intensified. Often a combination therapy with many different drugs is
required. 6) A specialist for diabetes should be consulted, if the therapeutic
goals can not be met over a period of six months.
PMID- 10667078
TI - [Skin check-up--who and when?].
AB - The skin is easy to access and therefore this organ is also an important
diagnostic tool for the general practitioner to establish a systemic and complex
disease. In addition skin cancer is the most prevalent malignancy and therefore
non-dermatologists should be able to make the diagnosis of an early skin cancer.
It is recommended to perform a whole body examination in all first visits. With
experience a whole skin check lasts no longer than five minutes. It is important
to recognise patients at risk for skin malignancies because they clearly profit
from a regular screening. Patients with atypical moles or with familial melanoma
syndrome and patients who already had malignant melanoma should get a yearly skin
examination performed by a trained expert. Patients who had basal cell carcinoma
run an almost 50% risk to produce a second basal cell carcinoma within three to
five years and therefore they are good candidates for a screening at a regular
base. The number of organ transplanted people is rising dramatically. In general
these patients are under marked immunosuppression and therefore they often
develop malignancies of the skin. In our Department such patients receive at
least one dermatological visit a year.
PMID- 10667079
TI - [Screening for prevention and early detection of colorectal carcinoma].
AB - Colorectal Cancer (CRC) fulfills all the criteria for a successful screening: i)
it is a frequent tumor associated with serious morbidity and mortality; ii)
recognition and treatment of premalignant lesions or early tumor stages improves
prognosis and lowers its incidence, respectively. During recent years, our
understanding of the biology, diagnosis and therapy of adenomas and CRCs led to
the identification of risk factors. Based on these, screening strategies differ
for individuals with average risk (age > or = 50 years, no risk factors) and
individuals with increased risk for CRC development (positive personal history
[CRC, colorectal adenomas, inflammatory bowel disease]; positive family history
[CRC, colorectal adenomas, hereditary syndromes]). The currently available
strategies aimed at prevention and early detection of CRCs (past history, family
history, rectal digital examination, fecal occult blood testing, endoscopy) are
discussed and recommendations for their implementation are formulated.
PMID- 10667080
TI - [Prostatic carcinoma. Screening--when and what?].
AB - Prostate cancer is now the most common cancer and the second most common cause of
death from cancer among men. Therapy of curative intention is only possible in
organ confined disease. The use of prostate specific antigen (PSA) and digital
rectal examination (DRE) results in a three fold increase in prostatic carcinoma
detection. Levels of PSA > 4 ng/ml are indications for sextant biopsies of the
prostate. There did not exist an intermediate range or 'grey zone' of PSA 4-10
ng/ml where wait and see diagnostic procedure is indicated. In PSA levels > 10
ng/ml curative therapy can only performed in 15-44% of the cases. PSA and DRE
examination should be performed between the age of 50 and 70 years when life
expectancy exceeds ten years. In case of familiar history the case finding has to
start at the age of 45. There is no support for the common opinion that early
detection finds clinically insignificant cancer since autoptical prevalence of
prostate cancer is about 40% and early detection discover only 3-4%. Results
about the usefulness of active screening in a population will be available in
2005.
PMID- 10667081
TI - [Screening for gynecologic-endocrinologic problems before menopause].
AB - Family and personal history as well as clinical examination are the basic data to
be known before laboratory examinations should be started. To obtain results that
can be correctly interpreted, the blood sampling has to be done in the early
morning hours between day 1 and 5 of the cycle, and for some hormones on an empty
stomach. Depending on the clinical data, the hormonal screening can be selective
and well directed, or it has to be broader. The presence or absence of
galactorrhea, of hot flushes and of androgenization or virilization play an
important role for the decision about the hormones to be determined. Furthermore,
an eventual desire infertility will influence the selection of the hormonal tests
to be done. The present review intends to propose some simple recommendations to
the non-specialist how a gynaecological-endocrinological screening for the most
important clinical questions should be organized.
PMID- 10667082
TI - [Guidelines for good practice: anti-ulcer agents, indications in the adult.
French Agency for Health Safety of Health Products].
PMID- 10667083
TI - [Outline of the problem of indices of therapeutic efficacy. 4. Expression of
efficacy when the underlying illness is incurable. Study Group for the Indices of
Efficacy].
AB - In chronic illness, when death or a non-fatal event can occur at any time, the
current efficacy indices are no longer appropriate to express the effect of the
treatment on the potential therapeutic objectives. The inappropriateness is not
dependent on the effect model. Clues for solutions are proposed.
PMID- 10667084
TI - Adverse drug reaction monitoring and the Internet: evaluation of the use of the
Internet by French Pharmacovigilance Centres and a non-exhaustive survey of
websites of interest for collecting information about adverse drug reaction.
AB - The Internet, indisputably the most important source of information obtainable in
real time, was long essentially the domain of researchers in the USA, but has now
become more accessible to French Pharmacovigilance Centres (CRPV) and
pharmaceutical companies. A questionnaire was sent to every CRPV to determine how
the Internet was perceived in terms of pharmacovigilance activities and existing
Websites of particular value to CRPVs were investigated. Analysis of the
questionnaires revealed that 66.7 per cent of CRPVs are connected to the Internet
but do not use it fully; 94 per cent of connected CRPVs use it essentially for
access to a bibliographic database such as Medline (88 per cent), and none
subscribes to discussion lists concerning alert messages on problems related to
drugs and therapeutics. Non-connected CRPVs do not intend to use the Internet
because of financial considerations, lack of time or the assumption that it is
not beneficial in everyday situations. Apparently, many French CRPVs are not
sufficiently aware of the importance of the Internet for professional purposes. A
non-exhaustive list of sites on the Internet providing information likely to be
of use to Pharmacovigilance Centres in their everyday activities is included. The
Internet offers far greater possibilities than research for bibliographic
references on Medline and could improve the manner in which pharmacovigilance is
practised.
PMID- 10667085
TI - [H1 antihistamines: the past and the future].
PMID- 10667086
TI - [Tomorrow's drug surveillance].
PMID- 10667087
TI - [Iodine status and the used of iodized antiseptics in the mother-newborn pair].
AB - Iodine status was evaluated by assessment of urinary iodine excretion in 221
mothers and their 223 newborns. During the first month after childbirth, 59.3 per
cent of the mothers and 26.5 per cent of the newborns received applications of
iodized antiseptic containing Polyvidone-iodine. 50.2 per cent of the newborns
and 24.9 per cent of the mothers had a urinary iodine of more than 20
micrograms/dl (iodine excess). For the mothers and the newborns who had received
applications of iodized antiseptic, 38.2 per cent and 74.6 per cent had an iodine
excess, respectively. This iodine excess is directly related to use of iodized
antiseptic. Such high iodine levels may contribute to the risk of thyroid
disorders, and particularly to transient congenital hypothyroidism at a critical
age for normal development of the nervous system.
PMID- 10667088
TI - [Use of iodized salt and the risk of iodine overload].
AB - Iodine-deficiency disorders are a major problem of public health in Morocco. To
mitigate this deficiency, the iodination of all the salt intended for human
consumption in a proportion of 80 +/- 10 mg/kg of salt has become obligatory
since a decree published in 1995. We estimated that this rate of iodized salt
issued risked inducing an iodine excess in the population. To check this
hypothesis, we provided 7 families made up of 28 subjects, who at the start were
consuming a non-iodized salt, with the decreed, iodized salt and we followed the
evolution of their urinary iodine excretion over a period of 3 weeks. The mean
values of urinary iodine excretion of the 28 subjects were 12.8 micrograms/dl
before use of iodized salt and 26.8, 35.5 and 63.2 micrograms/dl, respectively,
after 7, 14 and 21 days from the introduction of iodized salt into their diet.
After 21 days of the use of iodized salt, 84.6 per cent of the subjects had an
iodine excess. We conclude that prolonged use of this iodized salt exposes the
population to the risk of thyroid disorders.
PMID- 10667089
TI - Effect of dietary crude proteins on the reproductive function in the postpartum
dairy cow.
AB - The study was conducted on 216 dairy cows. Samples of feeds distributed to cows
were collected monthly for the purpose of determining their content in dry
matter, energy, crude proteins and mineral matter. Milk samples were collected
weekly for every cow from newly calved cows until confirmation of pregnancy by
rectal palpation at least 2 months after artificial insemination. These samples
were used for progesterone assays in skimmed milk, in order to assess the
interval between calving and return to ovarian activity [C-ROA], calving and
first insemination [C-I1], calving and conception [C-C] and number of
inseminations per conception (nI/C). Results have shown a significant negative
correlation between the duration of [C-ROA] and [C-C] intervals and the dietary
content in crude proteins (r = -0.720, p < 0.05 and r = -0.914, p < 0.01
respectively).
PMID- 10667090
TI - New model of atherosclerosis in sand rats subjected to a high cholesterol diet
and vitamin D2.
AB - In order to defeat the atheroresistance in sand rats, 25 animals were given a
high cholesterol diet for 45 days, which was then associated with oral treatment
with vitamin D2 2000 IU/day for a further 45 days. At days 0, 45 and 90, plasma
parameters, and aortic and heart morphology were examined. Results showed at D45
hypercholesterolaemia, increased plasma LDL and VLDL cholesterol, oxidized LDL,
triglycerides, free fatty acids (FFA) and calcium levels and moderate
hyperinsulinaemia. At D90, plasma-oxidized LDL and FFA were more enhanced,
whereas calcium level was reduced. Development of hyperglycaemia was associated
with hyperinsulinaemia and insulin resistance. The vitamin D2 administration
induced advanced lesions, represented by the degenerescence of elastic lamina,
smooth muscle cell proliferation and lipid calcic plaque at an ulcerated stage in
most cases. The ischaemic effects were represented by acute myocardial
infarction. The potential of the sand rat to develop atherosclerotic lesions at
different stages opens the field to therapeutic tests of new anti-atherogenic
agents.
PMID- 10667091
TI - Epidemiological study: chronotype and daytime sleepiness before and during
Ramadan.
AB - Few epidemiological data have been reported on the relation between Ramadan
fasting, life habits (meal frequency, sleep habits) and daytime sleepiness during
Ramadan. This paper presents the results of a detailed study of the chronotype
and daytime sleepiness before and during Ramadan. It was conducted on a sample of
264 subjects aged between 20 and 30 years. Results have revealed a significant
decrease in the meal frequency during Ramadan compared with the control period.
Before Ramadan, the majority of subjects woke up between 6 and 7 a.m. and went to
sleep between 10 and 11 p.m. however, during Ramadan fasting, they woke up after
8 a.m. and preferred to go to sleep later (after midnight). Chronotype as
evaluated by the Horne and Ostberg scale was changed significantly during
Ramadan: an increase of the evening type and a decrease in the morning type of
subjects was observed. Daytime sleepiness as evaluated by the Epworth Sleepiness
Scale was significantly increased.
PMID- 10667092
TI - Calcitonin-induced impairment in conditioning is antagonized by chronic
antidepressant drug treatment.
AB - The purpose of this study was to test the effect of calcitonin, when injected
into the lateral ventricle, on conditioning behaviour and to see whether
antidepressant drug treatment can antagonize calcitonin-induced impairment of
this behaviour. Conditioned response by conditional stimulus (CS) was compared in
control rat (CO) and in rats that received intraventricular perfusion of
calcitonin (CA), acute antidepressant drug treatment (ADa), acute antidepressant
drug treatment + calcitonin (ADa + CA), chronic antidepressant drug treatment (21
days) + calcitonin the day after (ADc + CA). Control rats acquired easily the
conditioned response, the CA group and ADa + CA had problems in making the
correlation between CS and unconditional stimulus (US), and consequently did not
acquire a conditioned response, but in the ADc + CA group, rats exhibited more
conditioned responses. The results indicate that calcitonin disrupts conditioning
processes and chronic but not acute antidepressant drug treatment can reverse the
effects of calcitonin.
PMID- 10667093
TI - Modulation of central GABAA receptor complex by somatostatin: a pharmacological
study.
AB - The goal of the present study was to determine the possible interactions between
somatostatin (SST) and gamma-aminobutyric acid (GABA). We thus investigated the
SST interaction with [35S]-tertiary butylbicyclophosphorothionate (TBPS) binding
sites of the cortical and hippocampal regions of the rat brain. The method used
to identify such effects is in vitro quantitative autoradiography. Thus, the
binding of the cage convulsant [35S]-TBPS to a picrotoxin-sensitive site in the
rat brain was used to investigate the modulatory action of SST on the GABAA
receptor complex. The addition of the peptide to the incubation medium results in
a dose-dependent inhibition of [35S]-TBPS in cortical and hippocampal structures.
Detailed analysis showed a dose-related effect of SST with relative potencies
comparable to those observed for 5 alpha 3 alpha P and 5 beta 3 alpha P. In
addition, these neurosteroids were able to enhance the efficacy of SST in
inhibiting [35S]-TBPS binding. The efficacy of SST in enhancing the inhibitory
action of neurosteroids was also evidenced. Furthermore, SST seems to mimic the
effects of these neurosteroids as well as GABA and picrotoxin on [35S]-TBPS
binding to the rat brain in every context examined. This suggests that
somatostatin allosterically modifies [35S]-TBPS binding through a mechanism
similar to that of GABA. On the other hand, a possible action of SST via
transduction systems on the GABAA receptor complex could also be suggested. These
results illustrate the importance of interactions in SST-mediated GABA
transmission in these brain regions.
PMID- 10667094
TI - Interaction of chlorpromazine and imipramine with model membranes.
AB - The aim of the present study is to examine the effect of phospholipids on the
lipid destabilization induced by chlorpromazine (CPZ) and imipramine (IP) at
different levels of pH. The large unilamellar vesicles (LUV) are formed in the
presence of calcein (60 mM). The vesicles containing calcein have been incubated
in the presence of CPZ and IP at pH 4.5 and pH 8. At pH 4.5 CPZ and IP induce a
rapid release of the calcein encapsulated in the liposomes. Calcein release, at
equal concentrations of pharmacological agent, is more important by CPZ than by
IP. At pH 8, the calcein release was more important than at pH 4.5; this effect
appears to be more significant for the CPZ than for the IP. In conclusion, the
insertion of chlorpromazine and imipramine into large unilamellar vesicles is
accompanied by a strong destabilization of the vesicles. These effects appear
more significant for chlorpromazine than for imipramine.
PMID- 10667095
TI - Myoclonic and tonic seizures elicited by microinjection of cholinergic drugs into
the inferior colliculus.
AB - The inferior colliculus (IC) is the initiation site in the neuronal network for
the epileptic audiogenic seizure (AGS). The present study investigates the
effects of alteration of IC cholinergic transmission on the elicitation of
epileptic seizures. Unilateral microinjections of carbachol (3 and 6
micrograms/0.2 microliter) into the IC elicited intense locomotor activity,
contraversive rotations and myoclonic seizures. This result indicates that the IC
is the initiation site for the induction of myoclonic seizures and suggests that
these myoclonic seizures may result from activation of m1 muscarinic receptors.
Microinjections of the nicotinic-muscarinic antagonist, gallamine (2 and 6
micrograms/0.2 microliter), into the IC induced AGS susceptibility. However,
microinjections of muscarinic antagonists, atropine (15 micrograms/0.2
microliter) and scopolamine (12 and 20 micrograms/0.2 microliter), or the
nicotinic antagonist, hexamethonium (12 and 20 micrograms/0.2 microliter), into
the IC have no effect. Gallamine-induced AGS susceptibility may result from a
selective blockade of m2 muscarinic receptors.
PMID- 10667096
TI - Interactions between neomycin and cerebral dopaminergic and serotoninergic
transmission in rats.
AB - The aim of this work was to investigate the effects of neomycin on monoamine
contents of rat striatal tissue. The analysis was performed by HPLC with
electrochemical detection. Rats were injected with neomycin (2 mg/kg; i.p.) and
killed at different times over 24 h. The striatal homogenate was injected in a
reversed-phase HPLC. Results showed a significant increase in dopamine tissue
level (+35 per cent; 4 h after neomycin injection) and a decrease (-36 per cent)
in the level of its metabolites. Striatal serotonin level showed a rapid and
significant (p < 0.001) increase, +130 per cent, 2 h after neomycin injection.
DOPAC/DA and 5HIAA/5HT ratios were reduced by 34 per cent and 46 per cent
respectively. These results indicate an inhibitory effect of neomycin on striatal
dopaminergic and serotoninergic systems. Several mechanisms could be involved in
these effects of neomycin in the biosynthesis process through stimulation of
tyrosine hydroxylase and tryptophane hydroxylase and/or MAO and COMT activities.
The blockage of calcium channels was also suggested.
PMID- 10667097
TI - Comparative effects of UW and SLS solutions on concentrative proline uptake in
cold preserved rat hepatocytes.
AB - In previous studies, we have shown that the rate of cell swelling induced by
concentrative proline uptake in isolated rat hepatocytes decreased by 50 per cent
after only 24 h of cold storage in University of Wisconsin (UW) solution, thereby
representing a sensitive marker of alterations in hepatocyte functions after cold
preservation and rewarming. We have thus used concentrative proline uptake to
compare the capacity of UW and sodium-lactobionate-sucrose (SLS) solutions to
maintain such differentiated hepatocyte functions. Isolated rat hepatocytes were
kept at 4 degrees C for 4, 10, 24 and 48 h in UW or SLS solutions, and
subsequently cultured at 37 degrees C for 1-2 h. Viability was measured by Trypan
blue exclusion. After rewarming, cells were subjected to a 10 min administration
of 10 mM proline and accumulation of the amino acid was assessed by changes in
cell volume as measured by digital analysis of single-cell images obtained under
bright-field illumination. Cell viability was reduced gradually and significantly
after 0 to 48 h of preservation, and rewarming amplified this effect. However,
loss of viability was similar in UW- and SLS-stored cells, as were initial steady
state cell volumes. Proline-induced swelling rate was reduced significantly by
13, 46 and by 57 per cent after 10, 24 and 48 h of preservation in UW solution,
respectively. There is no significant difference between SLS- and UW-preserved
hepatocyte swelling rates after 10 h and 48 h of cold preservation. However, the
decline in the swelling rate of SLS-preserved hepatocytes incubated for 24 h is
significantly lower than that of their UW-preserved counterparts. These results
show that the SLS solution can preserve differentiated hepatic functions as well
as the UW solution does.
PMID- 10667098
TI - In vitro effects of spiramycin and dirithromycin on IL1 beta production by human
LPS-stimulated mononuclear cells.
AB - Polymorphonuclear neutrophils are the predominant cells in acute inflammatory
lesions and their functions and recruitment are regulated by cytokines, including
IL1, TNF and IL8. Antibiotic modulation of inflammatory effects has stimulated
investigations of antibiotics for their potential activity as immunomodulators
over their primary bactericidal or bacteriostatic activities. This study reports
the influence of macrolides, spiramycin and dirithromycin on IL1 beta production.
Mononuclear cells, isolated from healthy human volunteers, were preincubated with
macrolides (0.1 to 500 micrograms/ml) and stimulated by Escherichia coli
lipopolysaccharide. Then, IL1 beta production was detected by western blotting
analysis. At therapeutic concentrations, dirithromycin and spiramycin seemed to
enhance IL1 beta production by LPS-stimulated cells, with +37 per cent and +28
per cent at 1 microgram/ml respectively. At supratherapeutic concentrations,
these drugs seemed to inhibit IL1 beta production through protein kinase C
inhibition, with inhibitory concentrations 50 per cent of 378 micrograms/ml for
dirithromycin and 234 micrograms/ml for spiramycin. So, macrolides may modulate
the host defence system through their influence on cytokine production.
PMID- 10667100
TI - Mycobacterium resistance to antimycobacterial reagent.
AB - This study was carried out in the tuberculosis laboratory of the Institut
National d'Hygiene in Rabat, Morocco, in 1997. The aim was to determine the
percentages of drug-resistant strains by using 150 antibiograms. Six
antimycobacterial medications were used as tuberculosis treatment: isoniazid
(INH), streptomycin (STM), rifampicin (RIF), ethambutol (EMB), kanamycin (KAN)
and p-amino-salicylic acid (PAS). The cultures were plated onto a simple agar
(Lowenstein-Jensen) plate containing different concentrations of drugs. This test
demonstrated the presence of major antimycobacterial (INH, RIF, STM)-resistant
strains of Mycobacterium tuberculosis in the following percentages respectively:
34.6 per cent, 33.1 per cent and 26.1 per cent and 80 per cent, 70 per cent and
40 per cent in the case of atypical mycobacteria. The association of INH/RIF
showed the highest percentage (27.6 per cent) for Mycobacterium tuberculosis and
70 per cent for atypical strains, whereas, when we associate INH/RIF/STM, the
resistance rate becomes 17.69 per cent for Mycobacterium tuberculosis and 25 per
cent for atypical mycobacteria. The resistance in question was a secondary or
acquired resistance because the tested strains were isolated from patients who
had not responded to standard tuberculosis treatment.
PMID- 10667099
TI - A comparison study of two therapeutic protocols for neurosyphilis.
AB - In Morocco, neurosyphilis is a serious public health problem. In the neurology
service at the specialist hospital in Rabat, two drug treatments were used.
Treatment A consisted of infusion over a period of 4 h of 20 MUI of penicillin G
per day for 3 weeks. Treatment B consisted of infusion over a period of 6 h of 30
MUI of penicillin G per day for 10 days. Each treatment was tested on a group of
eight neurosyphilitic patients as first-line treatment. On the first day of
treatment, both blood and CSF pharmacokinetics were sampled for each patient.
Blood and CSF were taken within 24 h. Penicillin G concentrations were determined
by a microbiological method. The results obtained showed that perfusions of
either 20 MUI or 30 MUI of penicillin allowed the achievement of high serum
concentrations. These increased progressively until reaching their maximum at T4
h for treatment A (from 92.33 to 106.38 micrograms/ml). For treatment B, maximal
concentration is obtained at T6 h (from 108 to 141.52 micrograms/ml). Penicillin
concentrations decreased immediately after stopping the perfusion. At CSF levels,
penicillin G concentrations were identical to serum concentrations. However, one
difference was observed: a one-hour difference between the serum and CSF peaks.
The CSF peak was achieved at T5 h for treatment A (0.063 to 2.25 micrograms/ml)
and at T7 h for treatment B (0.92 to 2.94 micrograms/ml). The concentrations
obtained were largely superior to the CMI of Treponema pallidum for both
treatment A and treatment B, at 47 times and 82 times higher respectively. The
recovery time of the patients was 14 h for treatment A and 24 h for B treatment.
These results have shown that therapeutic method B was more efficient than A.
Moreover, the evolution of penicillin G's diffusion in the CSF during treatment,
of cell counts of protein level, of the VDRL test and of the gamma-globulin rate
was studied.
PMID- 10667101
TI - [Medicines interacting with mitochondria: anti-ischemic effects of
trimetazidine].
AB - While mitochondria are key factors in energy production in cells they are also
key factors in their life cycle because under certain circumstances they can
provoke cellular apoptosis. Some 45 per cent of myocardial volume is taken up by
mitochondria. Furthermore, mitochondria are key to many aspects of neuronal
activity and can trigger neurodegenerative processes. Lipid oxidation is
responsible for the production of much ATP resynthesis in the heart but this
process is less oxygen efficient than glucose oxidation. During ischaemia, lipid
oxidation is suddenly blocked, but markedly increased during reperfusion, causing
accumulation of potentially toxic metabolites (acylcarnitines, acyl-CoA,
lysophospholipids). These metabolites can change calcium handling, inducing
arrhythmias. Trimetazidine, and another product in development, ranolazine, by
inhibiting lipid oxidation favours glucose oxidation and inhibits the production
of deleterious lipid metabolites. Thus this class of drugs can have beneficial
effects on myocardial metabolism without direct haemodynamic effects.
PMID- 10667102
TI - [Synthesis of benzimidazole derivatives by amino acid action on ortho
phenylenediamine, variously substituted in positions 4 and 5].
AB - As part of the synthesis of the benzimidazole derivative heterocyclique system,
we are interested in studying the condensation of the o-phenylenediamines with
amino-acids such as aspartic acid, serine and histidine. The interest that these
present is based mainly on their pharmacological properties. They have, in fact
anti-inflammatory, antidepressive, antibacterial and antihistamine properties. On
the other hand, it should be noted that 5,6-dimethyl-1-(alpha-D-ribofuranosyl)
benzimidazole constitutes part of vitamin B12. Taken together, these results led
us to pursue our research in this domain while focusing on new methods of
benzimidazolic derivative synthesis. It should be said that the obtaining of
these compounds depends on the quantity of the amino-acid. All synthesized
products have been characterized by infrared, nuclear magnetic resonance and mass
spectrometry.
PMID- 10667103
TI - [Synthesis and pharmacologic study of 1,5-dialkyl-1,5-benzodiazepine-2,4
dithiones].
AB - The synthesis and psychotropic activity of 1,5-diakyl-1,5-benzodiazepine-2,4
dithiones (alkyl = methyl, ethyl and benzyl radicals) were studied. Alkylation
reactions were performed in catalytic conditions by phase transfer. These
reactions allowed us to isolate only one kind of product N-alkyl. Acute toxicity
studies were conducted according to European protocols in two species of
appropriate mammals in order to discover the lethal doses. The activity of the
compounds on the CNS was then studied, using a battery of compartmental tests
used in psychopharmacology. No toxicity was demonstrated at therapeutic doses.
Each product had a sedative effect more or less pronounced and different from the
reference substance clobazam (Urbanyl). They also had myorelaxant and anxiolytic
effects, even lengthening the hypnotic effect of thiopental (synergic action).
PMID- 10667104
TI - Isomers of substituted 3-benzo[b]furyl and 3-thienylaminobutyric acids as potent
ligands of the GABA-B receptor: synthesis and preparative liquid chromatographic
separation.
AB - Baclofen (4-amino-3-(4-chlorophenyl)butyric acid) is the only selective agonist
for GABA-B receptors. Its R-(-)-enantiomer is about 100 times more active than
the S-(+)-enantiomer. In the search for new compounds that bind to GABA-B
receptors, it is very important to clarify the structural requirements. The
authors report the synthesis and separation of isomers of various 3
heteroaromatic (benzo[b]furan and thiophen) aminobutyric acids. The 4-amino-3-(7
methylbenzo[b]furan-2-yl)butanoic acid is a potent and specific ligand for GABA-B
receptors, with an IC50 value of 5.4 microM for the displacement of [3H] GABA.
PMID- 10667105
TI - Compatibility study of 5-fluorouracil with PVC bags after repackaging into two
types of infusion admixtures.
AB - The stability and compatibility of 5-fluorouracil (5-FU) in admixtures for
continuous intravenous infusion using PVC bags and administration sets were
studied. 5-fluorouracil was reconstituted and diluted to 1.8 mg/ml for infusion
in polyvinyl chloride and glass containers, and to 1 mg/ml to 16 mg/ml for
storage in polyvinyl chloride bags containing 5 per cent dextrose or 0.9 per cent
sodium chloride injections. Admixtures were stored at +4 degrees C and with
protection from light, for 7 days. Analyses were performed by HPLC. No
significant drug loss was observed during simulated infusions using PVC infusion
bags and administration sets vs glass bottles and administration sets, over an
infusion period used in hospitals (24 h). The solution stored at +4 degrees C
with protection from light in PVC bags showed that at 1 mg/ml to 16 mg/ml, 5
fluorouracil was stable at least for 7 days in 0.9 per cent sodium chloride and 5
per cent dextrose.
PMID- 10667106
TI - [The problem of therapeutic efficacy indices. 3. Comparison of the indices and
their use].
AB - Efficacy indices do not contain the same information although they are all
combinations of the same two quantities. Therefore, one should choose the proper
index. Actually, none is entirely appropriate. Each more or less meets the
specifications, depending on the underlying effect model for the therapy
considered. However, one can say that the absolute benefit is more appropriate
from the patient's point of view, the relative from the scientific point of view
and the number of patients to treat from the policy maker's point of view.
Nevertheless, this classification needs to be considered with caution. Finally,
it emerges from the review that none is fully relevant to express the efficacy of
a therapy, even in the most suitable condition, the acute illness.
PMID- 10667107
TI - [Constitutional thrombophilias: indications of the biological profile and
therapeutic consequences].
AB - In laboratory screening in patients with clinical thrombophilia (early
thromboembolism episode < 50 years, spontaneous thrombosis, recurrent thrombosis,
unusual site of thrombosis, thrombotic family history or coumarin-induced skin
necrosis complication), an isolated or combined inherited thrombophilia can be
observed: antithrombin (0.5 to 4.9 per cent), protein C (1.4 to 8.6 per cent) and
protein S (1.4 to 7.5 per cent) deficiencies or factor V Leiden (20 to 30 per
cent). Special attention is mandatory in prescribing biological exploration
because of the many physiological or pharmacological interferences which can
modify the results. Identification of a genetic defect may induce specific
management and individuals should receive counselling regarding the implications
of this diagnosis. Further prospective studies should help to determine the
thrombotic risk in symptomatic and non-symptomatic patients with inherited
thrombophilia and the risk/benefit ratio of laboratory screening for hereditary
thrombophilia and therapeutic intervention.
PMID- 10667108
TI - [The rational basis for the short-, medium-, and long-term evolution of the
pharmaceutical industry].
AB - In the last few years, a worldwide reorganization affecting the entire
pharmaceutical industry has begun and is now accelerating. This intense trend of
mergers, acquisitions, market entires++ and exits, reorientation and
diversification reflects a new environment. This article sets out to explain the
reasons behind this inescapable and rapid evolution.
PMID- 10667109
TI - [How to improve drug development and utilization in pediatrics].
AB - Insufficient drug evaluation in children and the lack of adapted pharmaceutical
formulations explain the importance of unlicensed and off-label prescriptions. As
a consequence a regulation proposed in the USA by the Food and Drug
Administration, requiring manufactures to assess the safety and effectiveness of
new drugs in paediatric patients, has recently been adopted. Appropriate means to
facilitate drug evaluation in children are now necessary in terms of recruitment
and methodology. A ten-centre American Pediatric Pharmacology Research Unit
network has been created and is being financed by the National Institute of
Health. A similar trend is evolving in Europe. Appropriate drug utilization in
children requires adequate formulations, administration devices and information
as well as improved knowledge on the long-term potential consequences of drug use
during growth and maturation.
PMID- 10667110
TI - [Selective cyclooxygenase-2 (COX-2) inhibitors: importance and limitations].
AB - The discovery of an inducible form of cyclooxygenase (COX-2) requires a
refinement of the theory that inhibition of cyclooxygenase activity explains both
therapeutic effects and side-effects of non-steroidal anti-inflammatory drugs
(NSAIDs). Selective COX-2 inhibitors have demonstrated in clinical trials a
significantly better gastrointestinal tolerability than classical NSAIDs, for the
same anti-inflammatory activity. Their tolerability in patients with active ulcer
or with a recent history of ulcer as well as in patients suffering from
cardiovascular or renal diseases has still to be investigated in detail. Their
therapeutic potential in several new indications, including pre-term labour,
colorectal cancer and Alzheimer's disease, is currently being investigated.
PMID- 10667111
TI - [Research on inflammatory mediators in asthma: new therapeutic approaches].
AB - During the National Meeting of Clinical Pharmacology (Giens 1998), the working
group exchanged information and examined the new therapeutic approaches to
inflammation in asthma. The group performed a state of the art review of the
current research on mediators of bronchial inflammation to determine new
pharmacological targets of therapeutic interest. An update on the development of
potential drugs acting on these targets was established. Specificities related to
asthma in terms of evaluation and development of anti-inflammatory drugs were
discussed. The place of pharmaco-economy in the development of anti-asthmatic
drugs was specified.
PMID- 10667112
TI - [The place of a new drug in the therapeutic strategy].
AB - A therapeutic strategy is a hierarchical set of appropriate measures to provide
an answer to a pathological state. A drug is a part of this set (together with
the diagnosis, the environment and the other medicinal interventions or not). A
new drug's place in a therapeutic strategy can be evaluated according to one or
several referential(s) when it (or they) exist, referentials which express the
state of knowledge before launch of the new drug. The drug's profile (indication
or contraindication, etc.), at the point when the marketing authorization is
given, is purely theoretical. One must evaluate the real place of the drug under
its real conditions of use (pragmatic trials, observable surveys). A new drugs'
place in a therapeutic strategy can only be evaluated in the course of time
unless a therapeutic revolution occurs.
PMID- 10667113
TI - [Education and role of the toxicologist].
AB - Toxicology covers a very large scientific area, needing specialists in the main
basic disciplines involved, and generalists with a large and practical overview.
Academic education, consequently, should take this necessity into account. This
education is presently satisfactory in France, even if some adjustments are
necessary, for the specialists but is inadequate for the generalists, whereas an
important need exists in industry. It should be emphasized that toxicology is a
profession and consequently practical experience is essential, as well as
continuing education. In view of this situation, an evaluation of toxicologists
in the course of their professional activities is necessary. In the USA, this
evaluation is devolved to the American Board of Toxicology and in Europe to the
Eurotox Accreditation. In conclusion of the Round Table, 8 recommendations are
proposed.
PMID- 10667114
TI - [How can institutional structures make clinical research in France more
operational?].
AB - The laws regulating the practice of clinical research in France, in particular
the law of 20 December 1988, the so-called Huriet's law, constitute a major
advance for medical progress. However, their implementation by administrative
offices generates practical difficulties which impair the development of applied
research in human beings. Beyond the laws themselves, it appears that our
institutions are unprepared to optimize the conduct of such research. This round
table sought to list the existing problems and to propose constructive solutions
or objectives to be reached to optimize clinical research in France, with a view
to improving French participation in international collaborative programmes,
notably European ones. Evaluation of projects and practices, financial support
and accounting, and some aspects of existing laws have been identified as the
major sources of our difficulties. Harmonization and clarification of our
procedures as well as improvement of training should be our primary objectives to
achieve a higher level of medical, scientific, financial and administrative
quality in the conduct of clinical research. Creation of a referential Web site,
designed and updated by a central public organization, is an imperative step
towards reaching these objectives.
PMID- 10667115
TI - [Making the administration of dry oral forms of cytotoxic medications safer].
PMID- 10667116
TI - [Safe oral administration of etoposide: application to pediatric practice].
PMID- 10667117
TI - [Carbamazepine intolerance mimicking infectious mononucleosis: apropos of 3
cases].
PMID- 10667118
TI - [Lansoprazole hypersensitivity syndrome].
PMID- 10667119
TI - [Acute disseminated lupus erythematosus. Responsibility of Corenitec: apropos of
a case].
PMID- 10667120
TI - [Latanoprost (Xalatan) and a systemic respiratory effect? Apropos of a case].
PMID- 10667121
TI - [Cardiotoxicity and immunomodulators: apropos of a case].
PMID- 10667122
TI - [Belief, science and morals of the majority].
PMID- 10667123
TI - [Electromagnetic effects of pacemaker-systems and the problem of the year 2000].
PMID- 10667124
TI - [Anxiety in genes and for genes].
PMID- 10667125
TI - [Pediatric day surgery of the respiratory tract--indications and prioritization].
AB - Ear, Nose and Throat (ENT) procedures are the most common types of surgery in
children and include adenoidectomy, tonsillectomy, myringotomy, ventilation tube
insertion or combinations of these. In order to study disease profile and
routines for referral and treatment in outpatient otolaryngologic surgery, data
were collected from 178 children operated consecutively during a six-week period
in 1998. Median time from referral to surgery was less than four months. The
majority of children operated for recurrent acute otitis media, tonsillitis or
upper respiratory infections had suffered from the disease for 12 months or less.
Obstructive symptoms were registered in 18% of these children. Most patients were
referred to the hospital by specialists in otolaryngology or paediatric medicine.
Surgery was more common in male than female-children, and median age at the time
of surgery was 4.2 years. There was an equal distribution of middle ear and
pharyngeal surgery.
PMID- 10667126
TI - [Efficient learning with data from own practice--experiences from the SATS
project].
AB - Between 1995 and 1998 the Norwegian Medical Association carried out a project to
develop and assess a quality improvement tool for use in general practice (SATS).
This method combines self-directed learning, documentation of practice and peer
group support. SATS defined performance indicators for registration of practice
by means of computerised patient records. Groups of four to ten general
practitioners used their own consultation data as a basis for learning cycles.
The practice evaluation indicates significant improvement in clinical work.
Participating doctors found that having their own recorded data examined in a
supportive peer environment was a major force for change. They reported
satisfaction with the method, and expressed an interest in trying out new topics.
However, the project demonstrated the need for simplification of terminology,
further development of group process methods and computer software. There is also
a need for strong local support of peer review groups.
PMID- 10667127
TI - [Transformed migraine--chronic daily headache].
AB - Transformed migraine is probably a common cause of chronic daily headache. The
International Headache Society system of diagnostic classification of headache
classifies headaches, not patients, and pays no attention to the long-term
evolution of the patient's headache. We support the suggestion made by
Silberstein et al. that transformed migraine should be used as a diagnostic label
in patients suffering from chronic daily headache with "migrainous features" and
a history of migraine. Since 1994, intravenous treatment with dihydroergotamine
(DHE) has been used for these patients. Among 16 patients suffering from chronic
daily headache which were treated with this drug in 1996, 10 patients reported
complete relief of headache at discharge from the hospital, but only four
patients experienced complete relief from headache for more than two weeks. We
think that the most important treatment for these patients are medicament
withdrawal, information, help and support so that patients may cope with their
headache. Dihydroergotamine can help patients going through a withdrawal regime.
PMID- 10667128
TI - [Miniinvasive plate osteosynthesis of distal tibial fractures].
AB - The end result after open reduction and internal fixation in distal leg fractures
is jeopardized by soft tissue complications. Functional conservative treatment of
the same type of fractures often results in delayed and non-union, malunion or
non-optimal functional result concerning ankle mobility. Mini-invasive
plateosteosynthesis was performed in ten patients with sustained juxta or intra
articular fractures of the distal tibia. In all patients, stable osteo-fixation
could be achieved and soft tissue complications did not affect the final result
in any of the patients. Mini-invasive plateosteosynthesis seems to be a good
treatment alternative in extra- or intraarticular fractures of the distal leg.
PMID- 10667129
TI - [Low molecular heparin in a pregnant women with heart valve prosthesis].
AB - Women with a prosthetic heart valve who wish to bear a child face a difficult
choice. Continued medication with warfarin during pregnancy will offer her a
reasonable good protection against thrombosis, but carries a considerable risk of
teratogenic effects. Subcutaneously administered heparin is an alternative to
warfarin. Standard (unfractionated) heparin has not offered sufficient protection
against valve thrombosis, which may be a life-threatening complication. We were
contacted by a woman who wished to become pregnant and who did not want to use
warfarin if this implied a risk for the foetus. We followed a protocol using low
molecular weight heparin in rather high doses. The dose was adjusted according to
the results of blood test controls, which confirmed increased need for
anticoagulation as the pregnancy evolved. Serial eccocardiography excluded valve
thrombosis. The woman needed psychological support from her general practitioner.
No complications occurred, and she gave birth to a normal child. We describe the
various alternatives for anticoagulant treatment in pregnant women with
mechanical heart valves. The choice of anticoagulant regimen and their
consequences must be thoroughly discussed with the woman.
PMID- 10667130
TI - [Myelomatosis and low level of vitamin B12].
AB - Many patients with multiple myeloma tend to have low serum cobalamin. The cause
of this remains unclear. The important issue is whether cobalamin therapy should
be used or not. We describe one case of megaloblastic erythropoiesis and multiple
myeloma, and refer to some of the few studies describing the subject. Most of the
patients with multiple myeloma are elderly, and the frequency of hypo- and
achlorhydria is therefore increased. It has been demonstrated that cobalamin
uptake and consumption is higher in myeloma cells than in normal bone marrow
cells, and that cobalamin may be required for paraprotein synthesis. These facts
may suggest that patients with multiple myeloma are more vulnerable to developing
megaloblastic anemia than others. Our patient received cobalamin therapy in
addition to cytostatic therapy for multiple myeloma without complications.
However, we cannot exclude that cobalamin therapy may accelerate multiple
myeloma; this should be considered when such therapy is given. However, accurate
guidelines require more studies.
PMID- 10667131
TI - [Why is dioxin harmful?].
AB - The scandal in Belgium last spring has drawn attention to the environmental
hazards of dioxins. Previous production of pesticides and widespread combustion
of organic material in the presence of chloride have lead to environmental
accumulation of these toxicants, which more precisely are termed polychlorinated
dibenzo-p-dioxins and dibenzofurans. Their very long biological half-lives in
combination with detectable biological effects at very low concentrations have
caused health concerns. Chloracne is the only well documented health effect in
man, but there are experimental evidence for carcinogenic, teratogenic,
reproductive and immunosuppressive effects. In this presentation we review
current knowledge about the cellular effects of dioxins. Dioxins bind to and
exert their effects through the cytoplasmic aryl hydrocarbon receptor, which acts
as a transcription factor and regulates a number of cytokines and microsomal
enzymes. Furthermore, dioxins interfere with hormonal signalling, and anti
oestrogenic effects, vitamin A inhibition and thyroxin mimicry have been
reported. Recently, effects on intracellular growth factor signalling have been
demonstrated. Dioxins inhibit epidermal growth factor receptor, activate protein
kinase C and other intracellular signal transducers, and activate transcription
factors. As overall understanding of their cellular mechanisms of toxicity is
lacking, we do not possess a complete basis for estimating the adverse health
effects of this group of environmental toxicants.
PMID- 10667132
TI - [Assessment of gestational age using ultrasound--can the method be improved?].
AB - In Norway, ultrasound measurement of the fetal biparietal diameter is used to
determine the date of confinement according to Eik-Nes & Grottum's method. We
aimed to evaluate the precision of this method. 8,029 women with singleton
pregnancy and spontaneous vaginal delivery were arranged in groups according to
gestational age at the time of the ultrasound examination. The precision of the
biparietal diameter measurement for predicting the date of birth was determined
for each group. An alternative method by Altman & Chitty was also tested on the
population. Eik-Nes & Grottum's method predicts well the date of confinement if
the biparietal diameter is measured at 17-20 weeks. Measurements at an earlier
stage predict the date of birth with less confidence, particularly during
completed gestational weeks 13-16, when the mean error reaches four days. Altman
& Chitty's chart seemed to perform more evenly for the various gestational ages,
but was systematically shifted by 3-4 days when used on our population. Eik-Nes &
Grottum's chart for assessing gestational age should preferably not be used
before 17 weeks of gestation. Introducing new charts based on a different
population is not a good option. New charts based on a Norwegian population are
needed.
PMID- 10667133
TI - [Internet and the physician-patient relationship--from "thank you" to "why"?].
AB - The combination of modern information technology and an increasing awareness if
consumer rights in the general population has lead to more demanding patients and
new challenges for doctors. By using a questionnaire we explored the extent to
which doctors feel that their clinical work is influenced by quality-demanding
and well-informed patients, and how the internet influences the communication
between doctor and patient. A representative sample of 1,276 Norwegian doctors
doing clinical work responded to the survey. A great majority of the doctors
expressed that "the informed patient" is becoming an integral part of their
regular workday. Three out of four Norwegian doctors had experience with patients
bringing internet information to the consultation setting. Most of these doctors
found this natural and unobtrusive; a few felt it influenced the doctor-patient
relationship in a negative way, while one out of every four doctors found meeting
"the informed patient" a positive challenge. One out of seven doctors with e-mail
access sporadically receives electronic mail from their patients, a few doctors
get such messages often. So far Norwegian doctors are of the opinion that the new
information technology has not introduced major changes or created unexpected
difficulties in the doctor-patient relationship.
PMID- 10667134
TI - [The use of Internet among Norwegian physicians].
AB - Access to the Internet increases rapidly, also among physicians. Little is known,
however, of to what extent this tool is actually used among various groups of
medical professionals, and how it compares to the use of more traditional ways of
professional development such as reading of medical literature or participation
in continuing medical education (CME) activities. In December of 1998, a 10%
random sample of all Norwegian doctors, 1,646 in all, were mailed a questionnaire
regarding their use of the Internet. 78% responded. 72% of Norwegian doctors had
Internet access, 24% respectively had access either at work, at home or at both
places. Doctors with access both at work and at home used the Internet
significantly more often and found it of greater professional value than did the
other groups. A smaller proportion of general practitioners than of other groups
in the profession, had access. About half (48%) of Norwegian doctors use the
Internet in a professional context. Research-oriented, male doctors, 30-49 years
of age, indicated the highest activity on the net. Doctors using the Internet
professionally had longer working hours, read more medical literature and
participated more often in CME activities than did non-users. With its universal
accessibility, the Internet has been seen as a major force in making medical
knowledge available to all doctors. This is not yet the case; for the time being,
it appears that the net widens the gap between doctors who actively seek new
professional knowledge and those who do not.
PMID- 10667135
TI - [Teleradiology--an effective agent for solidarity of health politics?].
PMID- 10667136
TI - [How can we justify scientific research?].
AB - The purpose and goal of scientific research have always been of concern to
philosophers and ethicists. This concern is closely linked to the values that
have justified scientific research. This paper takes a closer look at these
values: professional personal fulfillment, social utility, and methodological
norms such as value neutrality, openness and autonomy. These values originated in
different historical epochs; however, they are still of great importance, e.g. in
setting research priorities.
PMID- 10667137
TI - [Medicine with a human face--a scientific philosophic reflection].
AB - The essay deals with the relationship between the scientific and humanistic
social scientific aspects of medical concept formation and science. The first
part focuses on methodological differences associated with the two forms of
knowledge, emphasizing the distinction between quantitative and qualitative
methods. The differences are traced back to type of phenomenon or object
researched. On the basis of the special character of human beings and their
illnesses it is then argued that scientific medicine necessarily will have to
transcend the divide between the natural sciences on the one hand and the
humanities and social sciences (the "human sciences") on the other. The unity in
medicine is tied to its practice--the art of medicine as carried on in the
clinical meeting between doctor and patient.
PMID- 10667138
TI - [Reconsiliation, redemption and growth--a different perspective on the euthanasia
debate].
PMID- 10667139
TI - [Psychiatrists' certifications in diffuse disorders].
PMID- 10667140
TI - [Ritual circumcision should be performed in private practice].
PMID- 10667141
TI - [About the feedback between medicine and culture].
PMID- 10667142
TI - [American health care].
PMID- 10667143
TI - [Image of physicians as professionals].
PMID- 10667144
TI - Shortage of supplies forces suspension of schools' BCG programme.
PMID- 10667145
TI - [The infected artificial hip joint: possibilities, follow-up and results of
treatment].
AB - Infections after total hip replacement are still a severe problem. With current
therapies they can be managed successfully. In the present study we investigated
38 patients who were treated in our clinic because of infected total hip
arthroplasties. All patients had a minimal follow-up of two years. The three main
therapeutical forms are explained: the revision without removal of the
prosthesis, the one-stage exchange and the two-stage exchange. 35 of the 38
patients could be healed within the observation period (from 1984-1996). Two
patients died in the postoperative period from cardiopulmonary diseases. One
patient could not be healed and has still an ongoing infection. The success rate
was 92%, with good clinical results regarding pain, and walking ability. For the
patient, the treatment of an infection can be very perturbing. With the new
therapeutical forms the strain for the patient can be decreased. The type and
duration of the therapy before definitive treatment has no influence on the
success rate. In cases with a previous long-term therapy, a more complex
treatment may be necessary. The treatment should be performed in an experienced
clinic. The general practitioner plays an important part in the diagnosis and
after care. An adequate treatment can be offered to nearly every patient with an
infected total hip arthroplasty. This also applies to patients with long-term
infection and chronic fistulation.
PMID- 10667146
TI - [Swallowed dental prosthesis].
AB - A 66 year old man presented at the ambulatory with acute dysphagia. Inspectorial
and radiologic examination revealed a swallowed dental prosthesis. The importance
of the history and the clinical and radiological examination are discussed.
PMID- 10667148
TI - 20th Annual meeting of the Society for Maternal-Fetal Medicine. Miami Beach,
Florida, USA. January 31-February 5, 2000. Abstracts.
PMID- 10667147
TI - [Secondary amenorrhea with hyperprolactinemia. 23-year-old Turkish patient, chief
symptom: amenorrhea].
PMID- 10667149
TI - 10th International Hamburg Symposium on Tumor Markers. Hamburg, Germany, 5-7
December 1999. Abstracts.
PMID- 10667150
TI - 78th General session of the International Association for Dental Research, in
conjunction with the 29th annual meeting of the American Association for Dental
Research and the 24th annual meeting of the Canadian Association for Dental
Research. Washington, DC, USA. April 5-8, 2000. Abstracts.
PMID- 10667151
TI - Cytologic changes in hepatocellular carcinoma after percutaneous acetic acid
injection. Correlation with helical computed tomography findings.
AB - OBJECTIVE: To illustrate the cytologic features of hepatocellular carcinoma (HCC)
after percutaneous acetic acid injection (PAI) and to correlate the cytologic
findings with helical computed tomography (CT) findings. STUDY DESIGN: The study
included 30 patients with 37 HCC who had undergone PAI. Baseline cytomorphology
of HCC was evaluated by needle aspiration in all cases. PAI under ultrasound
guidance was done every three to seven days. Upon completion of PAI, fine needle
aspiration cytology was performed and followed by helical CT within two weeks.
The degeneration of HCC after PAI was classified into two grades. Grade 1 showed
incomplete degeneration (99% of nuclear area); grade 2 showed complete
degeneration or severe degeneration with cell debris or amorphous material only.
The specimens were stained with Riu's method (Romanowsky system). RESULTS: The
cytologic changes after PAI included decreased cell number, reduced cellular
aggregation, degeneration of cytoplasm and nucleus, and eosinophilic or
basophilic background in all tumors. In all the 37 tumors without enhancement on
helical CT, grade 2 degeneration was detected. CONCLUSION: Our results reveal
that grade 2 degeneration alone, demonstrated cytologically, could indicate
almost complete necrosis of HCC after PAI, probably implying no need for booster
PAI.
PMID- 10667152
TI - Immunocytochemical staining of Kupffer and endothelial cells in fine needle
aspiration cytology of hepatocellular carcinoma.
AB - OBJECTIVE: To evaluate the significance of the presence of Kupffer and
endothelial cells in distinguishing hepatocellular carcinoma (HCC) and
adenocarcinoma (AC) on cytologic smears. STUDY DESIGN: Fine needle aspiration
biopsies (FNABs) from 43 cases, 21 HCC and 22 AC (8 primary and 14 metastatic),
were immunostained for Factor VIII and vimentin as markers for endothelial cells
and Kupffer cells, respectively. Cytologic diagnosis was verified by histologic
and/or clinical follow-up. RESULTS: Eighteen of the 21 cases (86%) of HCC and 11
(5 primary and 6 metastatic) of 22 cases (50%) of AC showed positive
immunostaining for Factor VIII (P = .02). Vimentin immunostaining was positive in
55% of HCCs and 41% of ACs (P = .74). Forty-five percent of cases of HCC showed
immunostaining for both Factor VIII and vimentin, while 22% of cases of AC showed
immunostaining for both Factor VIII and vimentin (P = .18). CONCLUSION:
Immunocytochemical identification of endothelial cells using Factor VIII may have
important diagnostic value in separating HCC from adenocarcinomas in liver FNABs.
The presence of Kupffer cells labeled with vimentin has no diagnostic
significance in FNAB of these tumors.
PMID- 10667153
TI - Cytologic detection of cervical and endometrial carcinoma with other genital
tract involvement.
AB - OBJECTIVE: To investigate the possibility of a correct cytologic diagnosis of
cervical and endometrial carcinoma with other genital organ involvement. STUDY
DESIGN: From uteri removed during hysterectomy due to cervical (33 cases) and
endometrial (44 cases) cancer, samples were taken by cytobrush or spatula from
the ectocervix, endocervix and endometrium of uteri opened longitudinally. Smears
and cytosediments were stained by the Papanicolaou polychrome method. Moreover,
acid beta-galactosidase activity was demonstrated in serial cytosediments by the
indigogenic method of Lojda. From quenched tissue samples taken from the same
sites as those for cytology, a series of cryostat sections was prepared and
stained by hematoxylin and eosin or azure A, or subjected to the reaction for
acid beta-galactosidase. RESULTS: In 17 of 33 patients with cervical cancer, the
same type of cancer was also found in smears of the endocervix and endometrium.
In six patients the type of cancer was different. Of 44 patients with endometrial
cancer, 16 had an endocervical malignancy of the same type. In seven cases the
type of cancer was different. The reaction for acid beta-galactosidase helped in
the differentiation between squamous (negative reaction in cancer cells) and
cylindrocellular (positive reaction) cancer in cytologic preparations.
CONCLUSION: Before treatment, it is necessary to determine if there is
involvement of the endocervix in endometrial cancer and of the endometrium in
cervical cancer. Routine cytologic examination supplemented by the reaction for
acid beta-galactosidase proved to be useful for this purpose.
PMID- 10667154
TI - Cytologic diagnosis of axillary lymph node metastasis in breast cancer.
AB - OBJECTIVE: To compare imprint cytology with histology as a method for rapid
intraoperative diagnosis of axillary lymph node metastasis in breast cancer.
STUDY DESIGN: We evaluated imprint cytology, comparing it with histopathology. A
sample of 635 axillary lymph nodes was studied by imprint cytology using both
Giemsa stain and hematoxylin-eosin. The results were compared with each other and
with those of histopathologic examination. RESULTS: The Giemsa stain method, as
compared to histopathology, had 94% accuracy, 97% sensitivity, 90% specificity
and 94% positive prognostic value. The hematoxylin-eosin stain method was less
accurate than the Giemsa stain method as compared to histopathology (accuracy
91%, sensitivity 96%, specificity 83% and positive prognostic value 92%).
CONCLUSION: These data confirm the value of imprint cytology as a rapid, reliable
method of intraoperative assessment of axillary lymph node metastasis in breast
cancer. It results in better staging of the disease. It can be used
intraoperatively, as an alternative to frozen section, if a pathology laboratory
is not available, to exclude stage I patients from further treatment.
PMID- 10667155
TI - Clinical impact of atypical squamous cells of undetermined significance. A
cytohistologic comparison.
AB - OBJECTIVE: To assess the percentage of squamous intraepithelial lesions (SILs) in
the atypical squamous cells of undetermined significance (ASCUS) cytologic
diagnosis. STUDY DESIGN: From January 1994 to December 1995, 421 cervical Pap
smears with a diagnosis of ASCUS were followed with cervical biopsies within
three months. The ASCUS cytologic diagnosis was correlated with the histologic
findings and stratified according to age group, previous abnormal history and
cell type of ASCUS (squamoid vs. metaplastic). RESULTS: Histologic diagnosis
showed that of ASCUS diagnoses, 13% were normal, 34% were reactive, 4.8% were
atypical, 43% were low grade SIL, 4% were high grade SIL, 1% were carcinoma in
situ, and none were invasive lesions. The patients in the youngest group, up to
25 years, demonstrated the highest percentage of SIL. Patients with a previous
abnormal gynecologic history showed a higher percentage of SIL than those without
an abnormal history. SILs were observed in 51.5% of squamoid ASCUS and 36.5% of
metaplastic ASCUS. CONCLUSION: Forty-eight percent of females having an ASCUS
diagnosis on Pap smears had SIL and thus a preneoplastic lesion. The highest
percentage of SIL was found in females 25 years and younger. Our findings suggest
that an ASCUS diagnosis warrants ongoing follow-up.
PMID- 10667156
TI - p53 immunohistochemistry for distinguishing reactive mesothelium from low grade
ovarian carcinoma.
AB - OBJECTIVE: To determine the utility of immunohistochemical staining for p53 in
cell block material for distinguishing reactive mesothelium from borderline or
low grade ovarian carcinoma. STUDY DESIGN: Paraffin-embedded cell blocks from
paracentesis and pelvic wash fluid of 44 cases of ovarian carcinoma and 20 cases
containing only reactive mesothelium were immunostained for p53 using monoclonal
antibody DO-7. Tumor grades ranged from borderline to high grade and were serous
papillary (33), clear cell (3), mucinous (2), endometrioid (2), mixed serous
papillary/clear cell (3) and undifferentiated (1). The three authors
independently evaluated the staining, including estimation of the percentage and
intensity of positive nuclear staining. RESULTS: A separation of positive from
negative cases was seen when staining intensity was considered the critical
parameter; moderate to strong staining was considered truly positive. Seventy
three percent (8/11) of borderline tumors, 80% (8/10) of low grade tumors and 65%
(15/23) of intermediate to high grade tumors showed moderate to strong
positivity. Percentage of staining was a less-reliable parameter as 25% of
negative cases were positive by this assessment. CONCLUSION: p53
Immunohistochemistry, using monoclonal antibody DO-7 combined with standard
morphologic evaluation, may be useful in distinguishing benign reactive
mesothelium from borderline or low grade ovarian carcinoma.
PMID- 10667157
TI - Characteristics of high grade dyskaryotic cervical smears likely to be missed on
rapid rescreening.
AB - OBJECTIVE: To determine if there is a type of high grade dyskaryotic cervical
smear that is likely to be missed on rapid rescreening. STUDY DESIGN: Fifty high
grade dyskaryotic smears that had originally been incorrectly reported as
negative (FN) were admixed with 100 true negative smears. Each smear in the set
was rapidly reviewed at least 40 times. The FN smears that were picked out on >
50% of screenings were compared with those that were passed as unremarkable on >
50% of screenings for features of the dyskaryotic cell population. RESULTS:
Significant differences between the two types of FN smear were present in five
aspects of the dyskaryotic cell population. A FN smear is more likely to be
missed on rapid rescreening than to be selected for review if it has few
dyskaryotic cells; if the dyskaryotic cells are small, with pale nuclei; and if
they are scattered singly rather than in groups or syncytia. CONCLUSION: A type
of severely dyskaryotic smear is likely to evade rapid rescreening as well as
routine screening. This suggests that even when rapid rescreening is used as a
quality assurance measure, the "zero-error standard" is unlikely to be attained.
PMID- 10667158
TI - Cytohistologic correlation between AGUS and biopsy-detected lesions in
postmenopausal women.
AB - OBJECTIVE: To evaluate histologic findings in patients aged 50 and older whose
cervical smears revealed atypical glandular cells of undetermined significance
(AGUS). STUDY DESIGN: Computerized records spanning a four-year period were
retrospectively analyzed. Thirty patients over age 50 had cervical smears
interpreted as AGUS and had follow-up biopsies within 12 months following the
abnormal smear. The most important histologic diagnosis from the biopsy specimens
was correlated with the subcategory of the cervical smear. RESULTS: Five smears
interpreted as AGUS, favor reactive, revealed abnormal histology in four cases:
three endometrial polyps and one squamous carcinoma. Two smears interpreted as
AGUS, favor dysplasia, revealed squamous intraepithelial lesions on biopsy in
both cases. Seventeen smears interpreted as AGUS, favor endometrial cells,
revealed abnormal histology in 13 cases: 1 endocervical polyp, 6 endometrial
polyps, 3 endometrial hyperplasias and 3 adenomyosis. Six patients with smears
interpreted as AGUS, unclassifiable, revealed abnormal histology in five cases:
two endocervical polyps, one endometrial polyp, one endometrial carcinoma and one
ovarian carcinoma. CONCLUSION: The presence of AGUS in cervical smears from women
over 50 was highly predictive of abnormal lesions detected by histologic
examination. Although three cancers were detected on histologic follow-up, the
most common lesions detected were endometrial polyps.
PMID- 10667159
TI - Comparison of ThinPrep and conventional preparations on fine needle aspiration
cytology material.
AB - OBJECTIVE: To compare the various cytologic features on ThinPrep 2000 (TP) (Cytyc
Corporation, Marlborough, Massachusetts, U.S.A.) and conventional preparation
(CP) specimens from fine needle aspiration cytology (FNAC) material by a
semiquantitative scoring system. STUDY DESIGN: In this prospective study a total
of 71 consecutive cases were included. In each case, two passes were performed.
The first pass was used for conventional preparations, with direct smears made
and fixed immediately in 95% alcohol for Papanicolaou stain. For TP preparation a
second pass produced material for processing in the ThinPrep 2000. The TP and CP
slides were studied independently by two observers and representative slides of
CP and TP compared for cellularity, background blood and necrotic cell debris,
cell architecture, informative background, presence of monolayer cells, and
nuclear and cytoplasmic details by a semiquantitative scoring system. Statistical
analysis was performed by Wilcoxon's signed rank test on an SPSS program
(Chicago, Illinois, U.S.A.). RESULTS: TP preparations contained adequate
diagnostic cells in all cases and were tangibly superior to CP preparations
concerning monolayer cells, absence of blood and necrosis, and preservation of
nuclear and cytoplasmic detail (statistically significant, Wilcoxon's signed rank
test, P < .000). CONCLUSION: TP preparations are superior to conventional
preparations with regard to clear background, monolayer cell preparation and cell
preservation. It is easier and less time consuming to screen and interpret TP
preparations because the cells are limited to smaller areas on clear backgrounds,
with excellent cellular preservation. However, TP preparations are more expensive
than CP and require some experience for interpretation.
PMID- 10667160
TI - Identification of amylase crystalloids in cystic lesions of the parotid gland.
AB - OBJECTIVE: To identify alpha-amylase crystalloid formations in parotid specimens
obtained by fine needle aspiration. STUDY DESIGN: The study concerned three cases
of sialadenitis with crystalloid formation observed between 1993 and 1998. In one
of these cases, transmission electron microscopy, mass spectrometry and
measurement of amylase activity were used to characterize the nature of the
crystalloids. RESULTS: Light microscopy revealed the same crystalloid structure
in all three cases. In one case, where the material was saved, a biochemical
method made it possible to reveal high amylase activity, while protein
electrophoresis and mass spectrometry were used to identify salivary alpha
amylase. CONCLUSION: Crystalloids of salivary alpha-amylase can be identified by
May-Grunwald-Giemsa and Papanicolaou stain and can be rapidly confirmed through
determination of amylase activity.
PMID- 10667161
TI - Imprint cytology of core needle biopsy specimens of breast lesions. A rapid
approach to detecting malignancies, with comparison of cytologic and
histopathologic analyses of 173 cases.
AB - OBJECTIVE: To investigate whether imprint cytology of core needle biopsy (CNB)
specimens from breast lesions is a useful method of rapidly obtaining additional
diagnostic information and potentially can be used to reduce the number of
biopsies needed. STUDY DESIGN: Cytologic analysis was performed on 173 breast
lesions and compared with their histopathologic diagnoses (143 malignant and 30
benign). For imprint cytology, one CNB specimen was rolled between two slides and
stained with Diff-Quik and Papanicolaou stain. RESULTS: The diagnostic overall
accuracy of Diff-Quik stain (Papanicolaou stain) was 95.4% (95.9%), with a
sensitivity of 96.5% (97.2%), specificity of 90% (90%), positive predictive value
of 97.8% (97.8%) and negative predictive value of 84.3% (87.0%). There was no
statistically significant difference between the stains. Histopathologic analysis
had an overall accuracy of 97.7%, with a sensitivity of 97.2%, specificity and
positive predictive value of 100% and a negative predictive value of 88.2%.
CONCLUSION: Imprint cytology of CNBs is a sensitive method of detecting
malignancies in breast tumors. Diff-Quik is a rapid and reliable approach that
can reduce the number of biopsies. Inadequate and suspicious cases should be
evaluated based on complementary diagnostic procedures for breast lesions.
PMID- 10667162
TI - Molluscum contagiosum. A case report with fine needle aspiration cytologic
diagnosis and ultrastructural features.
AB - BACKGROUND: Cytomorphologic and ultrastructural features of molluscum
contagiosum, a rare skin lesion of viral etiology, are presented. CASE: A 4-month
old female was referred for fine needle aspiration cytology of papules over the
back and chest wall. A Giemsa-stained preparation of whitish material aspirated
from the chest wall nodule showed numerous large, intracytoplasmic, basophilic
bodies that pushed the host cell nucleus to the periphery, giving a signet-ring
appearance to a few cells. A cytologic diagnosis of molluscum contagiosum was
suggested. On electron microscopy numerous intracytoplasmic viral particles were
demonstrated, thus confirming the cytologic diagnosis. CONCLUSION: In clinically
unsuspected cases, the cytologic diagnosis of molluscum contagiosum can be
suggested by demonstrating pathognomonic molluscum bodies in aspirated material.
PMID- 10667163
TI - Fine needle aspiration cytology in systemic lupus erythematosus lymphadenopathy.
A case report.
AB - BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease of
unknown etiology characterized by inflammation in various organ systems,
including lymph nodes, due to the production of antinuclear antibodies. The onset
of disease is between ages 13 and 40 years, with a female preponderance. CASE: A
30-year-old female presented with right cervical lymphadenopathy and gave a
history of intermittent fever and swollen joints of 2.5 years' duration. The
patient was on intermittent corticosteroids. With a suggestion of tuberculous
lymphadenitis, the patient underwent fine needle aspiration (FNA). The diagnosis
of lupus adenopathy was established by FNA of enlarged right cervical lymph
nodes. Smears showed predominantly typical and atypical immunoblasts, plasma
cells, occasional Reed-Sternberg-like cells and dispersed hematoxylin bodies.
Smears were negative for acid-fast bacilli. CONCLUSION: When SLE patients develop
lymphadenopathy, FNA cytology helps differentiate lupus adenopathy from
infectious conditions, such as tuberculous adenitis, and from Kikuchi's
lymphadenitis.
PMID- 10667164
TI - Diagnosis of malignant mesothelioma by fine needle aspiration of a cervical lymph
node. A case report.
AB - BACKGROUND: Clinically documented distant metastases are rare in mesothelioma and
tend to occur late in the course of the disease, well after the diagnosis has
been made. In this instance, diagnosis was not made until a metastatic deposit
was identified microscopically in the enlarged lymph node. CASE: A 65-year-old
male with no definite history of occupational asbestos exposure presented with
chest pain, pleural effusion and supraclavicular lymphadenopathy. Cytologic
examination of material obtained by fine needle aspiration from his cervical
lymph node revealed malignant mesothelioma. This was confirmed on histology.
CONCLUSION: This was a particularly rare presentation and, as far as we are
aware, was the first case in which mesothelioma was diagnosed by fine needle
aspiration of a cervical lymph node. It serves to remind the pathologist that
when confronted with a lymph node involved by tumor, the possibility of
mesothelioma should be included in the differential diagnosis. The case also
demonstrates the usefulness of fine needle aspiration in the diagnosis of
metastatic tumor.
PMID- 10667165
TI - North American paragonimiasis. A case report.
AB - BACKGROUND: Paragonimiasis is a parasitic infection with a predilection for
pulmonary involvement. Paragonimus species occur throughout the world and exist
in nature in a snail-crustacean-mammalian life cycle. Human disease is most
frequently encountered in cultures that ingest raw or undercooked crustaceans.
North American paragonimiasis, caused by an endemic Paragonimus species,
Paragonimus kellicotti, predominantly causes disease in carnivorous and
omnivorous animals but may cause human disease if the intermediate host, the
crayfish, is ingested raw or undercooked. CASE: A previously healthy, 21-year-old
male was infected with P kellicotti and developed parasitic hemoptysis. The
disease was contracted through the ingestion of local, undercooked crayfish.
Diagnosis was established through the morphologic examination of eggs in the
cytologic preparation of bronchioalveolar lavage fluid. The patient was
successfully treated with praziquantel and recovered without incident.
CONCLUSION: Paragonimiasis is a cause of parasitic hemoptysis worldwide.
Paragonimiasis is infrequently encountered in North America and is usually not
considered in the differential diagnosis of hemoptysis unless specific risk
factors are known. The cytologist or cytopathologist, therefore, may be the first
to encounter the diagnostic eggs and should be familiar with this disease.
PMID- 10667166
TI - Granular cell ameloblastoma of the jaw. A report of two cases with fine needle
aspiration cytology.
AB - BACKGROUND: Fine needle aspiration cytology (FNAC) of jaw tumors has not been
studied extensively. Ameloblastomas are jaw tumors that show a wide morphologic
spectrum and thus may pose some diagnostic difficulties. Of the many types,
granular cell ameloblastoma (GCA) is an uncommon variant that possesses
distinctive features. To the best of our knowledge, there have been no previous
reports on the cytologic findings of GCA. We present two cases diagnosed by FNAC.
CASES: Two cases of GCA were diagnosed on cytology and subsequently confirmed on
histology. Both patients presented with a large, lytic jaw tumor. FNAC smears
showed characteristic granular cells along with spindle and basaloid cells.
CONCLUSION: Although GCAs are rare tumors, they possess distinctive features that
permit an accurate diagnosis, provided that this entity is kept in mind. This
tumor has to be differentiated from cystic odontogenic lesions, epulis and
granular cell myoblastoma. An accurate preoperative diagnosis also helps the
surgeon to plan more extensive surgery as these tumors show a great propensity
for malignant change and metastases.
PMID- 10667167
TI - Macrophagelike vacuolated renal tubular cells in the urine of a male with osmotic
nephrosis associated with intravenous immunoglobulin therapy. A case report.
AB - BACKGROUND: Osmotic nephrosis is a form of renal tubular injury that has been
found in patients treated with intravenous immunoglobulin (IVIG). CASE: A 46-year
old male who had two courses of chemotherapy for acute myelogenous leukemia was
found to have refractory thrombocytopenia. After IVIG (Sandoglobulin 12%,
Novartis) administration (1 g/kg) for five consecutive days, the patient became
oliguric and eventually anuric on the fifth dose. Hemodialysis was initiated, and
urine production was noted on day 2 of hospitalization. Routine cytologic
examination of fresh, voided urine showed numerous macrophagelike, bland
epithelial cells with abundant, multivacuolated cytoplasm. Cytokeratin
immunostain revealed positivity, thus confirming the epithelial origin of these
cells. CONCLUSION: To our knowledge, this is the first such case reported in the
English-language cytology literature. Awareness of a patient's clinical history
may be helpful in avoiding an incorrect diagnosis. Urine cytology may be useful
in obtaining an early diagnosis of osmotic nephrosis in patients receiving high
dose IVIG therapy that may eliminate the need for a renal biopsy.
PMID- 10667168
TI - Plasmacytoma of the breast. A report of two cases diagnosed by aspiration biopsy.
AB - BACKGROUND: Extramedullary plasmacytoma of the breast is an uncommon neoplasm,
occurring either as a solitary tumor or as evidence of disseminated multiple
myeloma. CASE: Two cases of plasmacytoma of the breast were diagnosed by fine
needle aspiration cytology. Aspiration smears showed a dispersed population of
plasmacytoid cells with eccentric nuclei, abundant cytoplasm and the
characteristic paranuclear hof. CONCLUSION: The clinical, cytologic and
immunophenotypic features of plasmacytoma are characteristic, and the importance
of distinguishing these neoplasms from primary mammary tumors is important to
avoid unnecessary surgery.
PMID- 10667169
TI - Retroplasia of bronchial columnar cells mimicking intranuclear viral inclusions.
PMID- 10667170
TI - Scraping cytology in the diagnosis of malignant squamous neoplasms of the skin.
PMID- 10667171
TI - Pleural effusion as an initial manifestation of multiple myeloma.
PMID- 10667172
TI - Fine needle aspiration cytology of lipoblastoma.
PMID- 10667173
TI - Imprint cytology of an intrapulmonary lymph node.
PMID- 10667174
TI - Microbes without borders: infectious disease, public health, and the journal.
PMID- 10667175
TI - What's housing got to do with it?
PMID- 10667176
TI - The microbial menace, then and now.
PMID- 10667177
TI - The Occupational Safety and Health Administration and the public health model.
PMID- 10667178
TI - Thinking about vaginal microbicide testing.
AB - A vaginal microbicide could slow the spread of HIV. To date, volunteers in
placebo-controlled trials of candidate microbicides have been counseled to use
condoms. This does not reduce the number of volunteers exposed to possible risk,
but it shifts the allotment of risk from those conducting the trial to those
women who may be least able to make autonomous decisions. Alternative ways of
meeting the obligation to offer volunteers active benefits are explored.
Counseling the use of condoms prolongs clinical trials and could cause tens of
thousands of otherwise avoidable deaths.
PMID- 10667179
TI - The making of a germ panic, then and now.
AB - Over the last 2 decades, a heightened interest in germs has been evident in many
aspects of American popular culture, including news coverage, advertisements, and
entertainment media. Although clearly a response to the AIDS epidemic and other
recent disease outbreaks, current obsessions with germs have some striking
parallels with a similar period of intense anxiety about disease germs that
occurred between 1900 and 1940. A comparison of these 2 periods of germ "panic"
suggests some of the long-term cultural trends that contributed to their making.
Both germ panics reflected anxieties about societal incorporation, associated
with expanding markets, transportation networks, and mass immigration. They were
also shaped by new trends in public health education, journalism, advertising,
and entertainment media. In comparison to the first germ panic, the current
discourse about the "revenge of the superbugs" is considerably more pessimistic
because of increasing worries about the environment, suspicions of governmental
authority, and distrust of expert knowledge. Yet, as popular anxieties about
infectious disease have increased, public health scientists have been attracting
favorable coverage in their role as "medical detectives" on the trail of the
"killer germ."
PMID- 10667180
TI - Immunization and the American way: 4 childhood vaccines.
AB - Childhood immunization constitutes one of the great success stories of American
public health in the 20th century. This essay provides a historical examination
of this topic through 4 particularly important examples: diphtheria, pertussis,
polio, and measles. Each case study illustrates how new vaccines have posed
unique challenges related to basic science, clinical trial methodology, medical
ethics, and public acceptance. A brief comparison of each story to the experience
of Great Britain, however, suggests an underlying unity connecting all 4
examples. Whereas the British led the way in introducing formal clinical trial
methodology in the field of immunization development, the Americans excelled in
the rapid translation of laboratory knowledge into strategies suitable for mass
application. Although this distinction appears to have diminished in recent
years, it offers insight into the sources of creativity underlying American
vaccine development and the corresponding difficulties sometimes created for
utilizing vaccines fruits rationally.
PMID- 10667181
TI - Violence victimization after HIV infection in a US probability sample of adult
patients in primary care.
AB - OBJECTIVES: This study estimated the proportion of HIV-infected adults who have
been assaulted by a partner or someone important to them since their HIV
diagnosis and the extent to which they reported HIV-seropositive status as a
cause of the violence. METHODS: Study participants were from a nationally
representative probability sample of 2864 HIV-infected adults who were receiving
medical care and were enrolled in the HIV Costs and Service Utilization Study.
All interviews (91% in person, 9% by telephone) were conducted with computer
assisted personal interviewing instruments. Interviews began in January 1996 and
ended 15 months later. RESULTS: Overall, 20.5% of the women, 11.5% of the men who
reported having sex with men, and 7.5% of the heterosexual men reported physical
harm since diagnosis, of whom nearly half reported HIV-seropositive status as a
cause of violent episodes. CONCLUSIONS: HIV-related care is an appropriate
setting for routine assessment of violence. Programs to cross-train staff in
antiviolence agencies and HIV care facilities need to be developed for men and
women with HIV infection.
PMID- 10667182
TI - A community-level HIV prevention intervention for inner-city women: results of
the women and infants demonstration projects.
AB - OBJECTIVES: This study examined the effects of a multisite community-level HIV
prevention intervention on women's condom-use behaviors. METHODS: The theory
based behavioral intervention was implemented with low-income, primarily African
American women in 4 urban communities. It was evaluated with data from pre- and
postintervention cross-sectional surveys in matched intervention and comparison
communities. RESULTS: At baseline, 68% of the women had no intention of using
condoms with their main partners and 70% were not using condoms consistently with
other partners. After 2 years of intervention activities, increases in rates of
talking with main partners about condoms were significantly larger in
intervention communities than in comparison communities (P = .03). Intervention
communities also had significant increases in the proportion of women who had
tried to get their main partners to use condoms (P = .01). The trends for condom
use with other partners were similar but nonsignificant. CONCLUSIONS: Many women
at risk for HIV infection are still not using condoms. Community-level
interventions may be an effective way to reach large numbers of women and change
their condom-use behaviors, particularly their behaviors with regard to
communication with main sex partners.
PMID- 10667183
TI - Mortality from invasive pneumococcal pneumonia in the era of antibiotic
resistance, 1995-1997.
AB - OBJECTIVES: This study examined epidemiologic factors affecting mortality from
pneumococcal pneumonia in 1995 through 1997. METHODS: Persons residing in a
surveillance area who had community-acquired pneumonia requiring hospitalization
and Streptococcus pneumoniae isolated from a sterile site were included in the
analysis. Factors affecting mortality were evaluated in univariate and
multivariate analyses. The number of deaths from pneumococcal pneumonia requiring
hospitalization in the United States in 1996 was estimated. RESULTS: Of 5837
cases, 12% were fatal. Increased mortality was associated with older age,
underlying disease. Asian race, and residence in Toronto/Peel, Ontario. When
these factors were controlled for, increased mortality was not associated with
resistance to penicillin or cefotaxime. However, when deaths during the first 4
hospital days were excluded, mortality was significantly associated with
penicillin minimum inhibitory concentrations of 4.0 or higher and cefotaxime
minimum inhibitory concentrations of 2.0 or higher. In 1996, about 7000 to 12,500
deaths occurred in the United States from pneumococcal pneumonia requiring
hospitalization. CONCLUSIONS: Older age and underlying disease remain the most
important factors influencing death from pneumococcal pneumonia. Mortality was
not elevated in most infections with beta-lactam-resistant pneumococci.
PMID- 10667184
TI - "Broken windows" and the risk of gonorrhea.
AB - OBJECTIVES: We examined the relationships between neighborhood conditions and
gonorrhea. METHODS: We assessed 55 block groups by rating housing and street
conditions. We mapped all cases of gonorrhea between 1994 and 1996 and calculated
aggregated case rates by block group. We obtained public school inspection
reports and assigned findings to the block groups served by the neighborhood
schools. A "broken windows" index measured housing quality, abandoned cars,
graffiti, trash, and public school deterioration. Using data from the 1990 census
and 1995 updates, we determined the association between "broken windows,"
demographic characteristics, and gonorrhea rates. RESULTS: The broken windows
index explained more of the variance in gonorrhea rates than did a poverty index
measuring income, unemployment, and low education. In high-poverty neighborhoods,
block groups with high broken windows scores had significantly higher gonorrhea
rates than block groups with low broken windows scores (46.6 per 1000 vs 25.8 per
1000; P < .001). CONCLUSIONS: The robust association of deteriorated physical
conditions of local neighborhoods with gonorrhea rates, independent of poverty,
merits an intervention trial to test whether the environment has a causal role in
influencing high-risk sexual behaviors.
PMID- 10667185
TI - Effectiveness of an intervention promoting the female condom to patients at
sexually transmitted disease clinics.
AB - OBJECTIVES: This study evaluated a behavioral intervention designed to promote
female condoms and reduce unprotected sex among women at high risk for acquiring
sexually transmitted diseases (STDs). METHODS: The effect of the intervention on
barrier use was evaluated with a pretest-posttest design with 1159 female STD
clinic patients. RESULTS: Among participants with follow-up data, 79% used the
female condom at least once and often multiple times. More than one third of
those who completed the study used female condoms throughout follow-up. Use of
barrier protection increased significantly after the intervention, and high use
was maintained during a 6-month follow-up. To account for attrition, the use of
protection by all subjects was projected under 3 conservative assumptions. The
initial visit and termination visit projections suggest that use increased
sharply after the intervention and declined during follow-up but remained
elevated compared with the baseline. CONCLUSIONS: Many clients of public STD
clinics will try, and some will continue, to use female condoms when they are
promoted positively and when women are trained to use them correctly and to
promote them to their partners. A behavioral intervention that promotes both
female and male condoms can increase barrier use.
PMID- 10667186
TI - Factors associated with tympanostomy tube insertion among preschool-aged children
in the United States.
AB - OBJECTIVES: Recurrent and persistent otitis media is often treated by
tympanostomy tube insertion to ventilate the middle ear and restore hearing. This
study examined the factors that predict which children are most likely to receive
tympanostomy tubes through 3 years of age. METHODS: Multiple logistic regression
was conducted on data from a nationally representative sample of children (N =
8285). RESULTS: By 3 years of age, 6.8% of US children had tubes inserted.
Logistic regression indicated that after control for number of ear infections,
children without any gaps in health insurance, who attended a day-care center,
who were White, whose birth-weight was less than 1500 g, and who lived in the
Midwest or South were significantly more likely to have tympanostomy tubes.
CONCLUSIONS: These data suggest that differences exist as to who receives tubes.
Of particular concern are differences by race/ethnicity and continuity of health
insurance coverage. With expansions in health care coverage to larger proportions
of uninsured children, it will be important to monitor these programs to ensure
that all children who may need tympanostomy tubes have access to them.
PMID- 10667187
TI - Relationships between obesity and DSM-IV major depressive disorder, suicide
ideation, and suicide attempts: results from a general population study.
AB - OBJECTIVES: This study sought to test the relationships between relative body
weight and clinical depression, suicide ideation, and suicide attempts in an
adult US general population sample. METHODS: Respondents were 40,086 African
American and White participants interviewed in a national survey. Outcome
measures were past-year major depression, suicide ideation, and suicide attempts
diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders,
Fourth Edition. The primary predictor was relative body weight, treated both
continuously (i.e., body mass index [BMI]) and categorically in logistic
regression analyses. Covariates included age, income and education, disease
status, and drug and alcohol use. RESULTS: Relative body weight was associated
with major depression, suicide attempts, and suicide ideation, although
relationships were different for men and women. Among women, increased BMI was
associated with both major depression and suicide ideation. Among men, lower BMI
was associated with major depression, suicide attempts, and suicide ideation.
There were no racial differences. CONCLUSIONS: Differences in BMI, or weight
status, were associated with the probability of past-year major depression,
suicide attempts, and suicide ideation. Longitudinal studies are needed to
differentiate the causal pathways and mechanisms linking physical and psychiatric
conditions.
PMID- 10667188
TI - Risk factors for homelessness among indigent urban adults with no history of
psychotic illness: a case-control study.
AB - OBJECTIVES: This study identified risk factors for homelessness among indigent
urban adults without dependent children and with no history of psychotic illness.
METHODS: We conducted a matched case-control study, stratified by sex, of 200
newly homeless men and women and 200 indigent men and women with no history of
homelessness. Newly homeless case subjects were recruited from shelter assessment
centers in New York City. Never-homeless control subjects, selected from public
assistance centers, were single adults applying for home relief. Control subjects
were matched with case subjects according to ethnicity, age, and sex. Trained
interviewers employed standardized research instruments to probe 3 domains of
risk factors: symptom severity and substance use disorder, family support and
functioning, and prior use of services. RESULTS: Significant interaction effects
by sex were present for symptom severity, heroin use disorder, and prior service
use. Greater numbers of the homeless of both sexes lacked a high school diploma
and had less income from all sources, including from their families, than of the
never homeless. CONCLUSIONS: Newly homeless men and women with no history of
psychotic illness differed from their never-homeless counterparts in the 3
domains investigated, but socioeconomic factors were also important.
PMID- 10667189
TI - Patterns and correlates of physical activity among US women 40 years and older.
AB - OBJECTIVES: This study describes the patterns of physical activity among minority
women by using a variety of definitions and determines sociodemographic and
behavioral correlates of physical activity in this population. METHODS: A cross
sectional study was conducted in 1996 and 1997 among US women 40 years and older
(n = 2912) of the following racial/ethnic groups: African American, American
Indian/Alaskan Native, Hispanic, and White. RESULTS: Physical activity was lowest
among African Americans and American Indians/Alaskan Natives (adjusted odds
ratios [ORs] for no leisure-time activity were 1.35 [95% confidence interval (CI)
= 1.08, 1.68] and 1.65 [95% CI = 1.33, 2.06], respectively). A much higher
proportion of women were classified as being physically active when occupational
activity rather than more traditional assessments of leisure activity were used
to determine level of physical activity. On the basis of a composite definition
of physical activity, 72% of respondents reported being physically active. Women
living in rural regions (OR = 1.33; 95% CI = 1.12, 1.58) were more likely than
urban inhabitants to be completely inactive during leisure time. CONCLUSIONS:
Minority women are among the least active subgroups in American society, although
not all groups are less active than White women when all domains of physical
activity are taken into account.
PMID- 10667190
TI - Prevalence and risk factors of drug-resistant tuberculosis along the Mexico-Texas
border.
AB - OBJECTIVES: This study determined factors associated with drug resistance among
3496 patients with tuberculosis who resided in Texas counties along the Mexican
border. METHODS: Univariate and logistic regression analyses were performed to
identify risk factors associated with drug resistance. RESULTS: Among patients
with a history of previous tuberculosis, being 19 years or younger was the only
factor associated with multiple drug resistance. Female sex, being 20 to 39 years
of age, and foreign birth were risk factors for resistance among patients with no
history of previous tuberculosis. CONCLUSIONS: Factors contributing to drug
resistance among Hispanic tuberculosis patients along the Texas-Mexico border may
differ from those among other populations in the United States.
PMID- 10667191
TI - Implementation of guidelines for HIV counseling and voluntary HIV testing of
pregnant women.
AB - OBJECTIVES: This study assessed HIV counseling and testing among pregnant women.
METHODS: A survey was administered to 9115 women who gave birth at 66 Chicago
area hospitals in 1997 and 1998. RESULTS: Fifty-eight percent of the women
received HIV counseling, and 65% were offered testing. Fifty-six percent were
tested for HIV. Among the women tested, 88% were given their test result. Women
were more likely to be tested if they received HIV counseling and were more
likely to be offered testing if they received such counseling. CONCLUSIONS: Rates
of HIV counseling for, and offers of testing to, pregnant women need to be
increased.
PMID- 10667192
TI - Diminishing educational differences in breast cancer mortality among Finnish
women: a register-based 25-year follow-up.
AB - OBJECTIVES: This study examined trends in breast cancer mortality by education,
age, and birth cohort. METHODS: Census records of Finnish women 35 years and
older were linked with death records for 1971 through 1995. RESULTS: Excess
breast cancer mortality of more-educated women has declined rapidly, mainly
because of increasing mortality among less-educated women and stable or
decreasing mortality among more-educated 35- to 64-year-old women. During the
1990s, mortality among more-educated 50- to 64-year-old women declined
particularly fast. CONCLUSIONS: The causes of declining differences by education
in breast cancer mortality are difficult to verify, but they may be due in part
to narrowing differences in reproductive behavior among the younger birth cohorts
and to a period effect possibly associated with the introduction of breast cancer
screening in the late 1980s.
PMID- 10667193
TI - Increasing trends in the use of breast-conserving surgery in California.
AB - OBJECTIVES: The purpose of this study was to determine temporal trends in breast
conserving surgery in California from 1988 through 1995. METHODS: Logistic
regression was used to analyze data on 104,466 cases of early-stage breast cancer
reported to the California Cancer Registry. RESULTS: A monotonically increasing
trend in breast-conserving surgery was detected after adjustment for age,
race/ethnicity, stage at diagnosis, and neighborhood education level. Breast
conserving surgery increased at similar rates among all racial/ethnic groups.
Older age, Asian or Hispanic race/ethnicity, late-stage diagnosis, and residence
in an undereducated neighborhood were factors associated with lower use of breast
conserving surgery. CONCLUSIONS: Although disparities are evident, use of breast
conserving surgery increased steadily in all groups examined in this study.
PMID- 10667194
TI - Acceptability and feasibility of urine screening for Chlamydia and gonorrhea in
community organizations: perspectives from Denver and St Louis.
PMID- 10667195
TI - Need for HIV/AIDS early identification and preventive measures among middle-aged
and elderly women.
PMID- 10667196
TI - Re McKinlay and Marceau's "Tale of 3 tails".
PMID- 10667197
TI - Educating public health professionals.
PMID- 10667198
TI - Telomerase. A target for anticancer therapy.
AB - Telomerase is absent in most normal tissues, but is abnormally reactivated in all
major cancer types. Telomerase enables tumor cells to maintain telomere length,
allowing indefinite replicative capacity. Albeit not sufficient in itself to
induce neoplasia, telomerase is believed to be necessary for cancer cells to grow
without limit. The presence of telomerase has been detected in virtually all
cancer types including the most prevalent cancers of the prostate, breast, lung,
colon, bladder, uterus, ovary, and pancreas as well as in lymphomas, leukemias,
and melanomas. In addition, data from cancer patients indicate that telomerase
levels correlate with clinical outcome in neuroblastomas, leukemias, and
prostate, gastric, and breast cancers. Studies using an antisense to the human
telomerase RNA component demonstrate that telomerase in human tumor lines can be
blocked ex vivo. In these experiments, telomerase inhibition led to telomere
shortening and cancer cell death, validating telomerase as a target for
anticancer therapy. Telomerase is a uniquely appealing target for drug discovery
because its dichotomic expression in normal versus cancer cells suggests that no
serious side effects would result from a treatment abrogating telomerase
activity. A variety of approaches to telomerase inhibition are being investigated
and are discussed.
PMID- 10667199
TI - A paradigm for cancer treatment using the retinoblastoma gene in a mouse model.
AB - Discovery of tumor suppressor genes has provided a rational approach to cancer
prevention and treatment. Loss of retinoblastoma susceptibility gene (Rb)
function is a rate-limiting event in the development of human and mouse cancers.
Establishment of animal models of cancer associated with Rb deficiency allowed us
to develop and test long-awaited approaches to genetic correction for treating
tumors in vivo. Recent studies demonstrated that (1) prevention of carcinogenesis
is achieved by correction of gene copy number in Rb+/- mice, and (2)
reconstitution of Rb gene functions is sufficient for suppression of neoplasia in
immunocompetent mice. These results fulfill a promise of cancer treatment by
reconstitution of tumor suppressor function.
PMID- 10667200
TI - Trichostatin and leptomycin. Inhibition of histone deacetylation and signal
dependent nuclear export.
AB - Trichostatin A (TSA), an inhibitor of the eukaryotic cell cycle and an inducer of
morphological reversion of transformed cells, inhibits histone deacetylase (HDAC)
at nanomolar concentrations. Recently, trapoxin, oxamflatin, and FR901228,
antitumor agents structurally unrelated to TSA, were found to be potent HDAC
inhibitors. These inhibitors activate expression of p21Waf1 and 16INK4A in a p53
independent manner. Changes in the expression of these cell cycle regulators by
an increase in histone acetylation may be responsible for cell cycle arrest and
antitumor activity by HDAC inhibitors. The target molecule of leptomycin B (LMB),
a potent antitumor agent, was genetically and biochemically identified as CRM1, a
protein reported as being required for chromosome structure control. We showed
that CRM1 was a receptor for the nuclear export signal (NES) and that LMB
inhibited nuclear export of proteins. Using LMB, we identified a novel NES in
fission yeast transcription factor Pap1, the function of which is abolished by
oxidative stress in a manner conserved in eukaryotes.
PMID- 10667201
TI - The dual role of cytoskeletal anchor proteins in cell adhesion and signal
transduction.
AB - beta-Catenin and plakoglobin are homologous proteins having a dual role in cell
adhesion and in transactivation together with LEF/TCF transcription factors.
Overexpression of plakoglobin suppresses tumorigenicity, whereas increased beta
catenin levels are considered oncogenic. We compared the nuclear translocation
and transactivation by beta-catenin and plakoglobin. Overexpression of each
protein resulted in nuclear translocation and formation of structures that also
contained LEF-1 and vinculin with beta-catenin, but not with plakoglobin.
Transfection of LEF-1 translocated endogenous beta-catenin, but not plakoglobin
into the nucleus. Chimeras of the Gal4 DNA-binding domain and the transactivation
domains of either plakoglobin or beta-catenin were equally potent in
transactivation, but induction of LEF-1-responsive transcription was higher with
beta-catenin. Overexpression of wt plakoglobin or mutant beta-catenin lacking the
transactivation domain induced nuclear accumulation of the endogenous beta
catenin and LEF-1-responsive transactivation. The nuclear localization and
constitutive beta-catenin-dependent transactivation in SW480 cancer cells were
inhibited by overexpressing cadherin or alpha-catenin. Moreover, transfecting the
cytoplasmic tail of cadherin inhibited transactivation, by competition with LEF-1
in the nucleus for beta-catenin binding. The results indicate that (1)
plakoglobin and beta-catenin differ in nuclear translocation and complexing with
LEF-1 and vinculin, (2) LEF-1-dependent transactivation is mainly driven by beta
catenin, (3) cadherin and alpha-catenin can sequester beta-catenin, inhibit its
transcriptional activity, and antagonize its oncogenic action.
PMID- 10667202
TI - Cytoskeletal tumor suppressors that block oncogenic RAS signaling.
AB - Several distinct peptides or drugs that block the Rho family GTPases-mediated
pathways were found to suppress RAS-induced malignant phenotype. They include (1)
C3 enzyme that selectively inactivates Rho, (2) ACK42, a peptide that blocks the
interaction of CDC42 with its effectors such as ACKs, (3) PAK18, a peptide that
blocks the activation of PAK and membrane ruffling, and (4) actin-binding drugs,
chaetoglobosin K (CK) and MKT-077, that block membrane ruffling by capping and
bundling actin filaments, respectively.
PMID- 10667203
TI - Antiangiogenic domains shared by thrombospondins and metallospondins, a new
family of angiogenic inhibitors.
AB - The growth of solid tumors has been shown to depend on neovascularization. By
understanding the mechanisms that control the neovascular response, it may be
possible to design therapeutic strategies to selectively prevent or halt
pathologic vascular growth and restrain cancer progression. Thrombospondin-1 is
an extracellular matrix protein that among several functions suppresses capillary
growth in angiogenesis assays. We have demonstrated that within the context of
the mammary gland TSP1 can modulate normal development of blood vessels.
Expression of TSP1 in transgenic animals under the control of the MMTV promoter
was associated with a 50-72% reduction in capillary growth. In addition, TSP1
reduced tumor size in transgenic overexpressors. The data suggest an important
role for TSP1 in modulating vascular growth in both normal and pathologic
tissues. The antiangiogenic region of TSP1 has been mapped to the type I
(properdin) repeats. To identify novel proteins with such a domain, we have
cloned two cDNAs (METH-1 and METH-2) which also have antiangiogenic properties.
In addition to carboxyterminal thrombospondin-like domains they also contain
metalloproteinase and disintegrin sequences. Expression of both proteins is broad
but nonoverlapping. Recombinant fragments from these sequences have strong
antiangiogenic potential in the CAM and cornea pocket assays. At the same molar
ratio, METH-1 and METH-2 are about 20-fold more potent than TSP1. We predict that
these proteins are likely endogenous modulators of vascular growth with relevant
therapeutic potential in cancer and other disease states.
PMID- 10667204
TI - Immunotherapy of cancer.
AB - The goal of cancer treatment is to develop modalities that specifically target
tumor cells, thereby avoiding unnecessary side effects to normal tissue. Vaccine
strategies that result in the activation of the immune system specifically
against proteins expressed by a cancer have the potential to be effective
treatment for this purpose. An early vaccine approach that was developed by our
group involves the insertion of the granulocyte-macrophage colony stimulating
factor (GM-CSF) gene into cancer cells that are then used to immunize patients.
These genetically modified tumor cells produce the immune activating protein GM
CSF in the local environment of the tumor cells, specifically activating the
patient's T cells to eradicate cancer at metastatic sites. We have performed many
studies that demonstrate that this vaccine can cure mice of cancer. We recently
demonstrated that this approach can activate an immune response in patients with
renal cell carcinoma. We are currently testing a similar approach in patients
with pancreatic cancer. Until recently, whole tumor cells were used to produce
the vaccine because the proteins expressed by the tumor cells that can be
recognized by the immune system were unknown. However, recent advances have
allowed the identification of many of the proteins expressed by some cancers. In
addition, significant attention has been focused on the mechanisms by which
antitumor immunity can be modulated. These active areas of research will
undoubtably lead to the development of more specific and more potent vaccine
strategies in the near future. The first part of this paper focuses on data from
two recent clinical trials that evaluated the whole tumor cell approach. The
second part of this paper discusses some of the more exciting antigen-specific
vaccine approaches that are under development for the treatment of cancer.
PMID- 10667205
TI - Intracellular signaling of the TGF-beta superfamily by Smad proteins.
AB - TGF-beta is a potent inhibitor of cell growth, and accumulating evidence suggests
that perturbation of the TGF-beta signaling pathway leads to tumorigenesis. Smads
are recently identified proteins that mediate intracellular signaling of the TGF
beta superfamily. Smads 2 and 3 are phosphorylated by the TGF-beta type I
receptor. Smad4 was originally identified as a candidate tumor suppressor gene in
pancreatic cancers. Smads 2 and 3 form complexes with Smad4 upon TGF-beta
stimulation. The heteromeric Smad complexes translocate into the nucleus, where
they activate expression of target genes. Our recent study demonstrated that
Smads exist as monomers in the absence of TGF-beta. Smads 2 and 3 form homo- as
well as hetero-oligomers with Smad4 upon ligand stimulation. Both homo-oligomers
and hetero-oligomers directly bind to DNA, suggesting that the signaling pathway
of Smads may be multiplex. Smads 2 and 3 associate with transcriptional
coactivators such as p300 in a ligand-dependent manner, p300 enhances
transactivation by TGF-beta, suggesting that coactivators link Smads to the basal
transcriptional machinery. A missense mutation of Smad2 identified in colorectal
and lung cancers was introduced to Smad3. The mutant, Smad3(DE), blocked the
activation of wild-type Smad2 and Smad3. Thus, the missense mutation not only
disrupts the function of the wild-type Smad but also creates a dominant-negative
Smad, which could actively contribute to oncogenesis.
PMID- 10667206
TI - Bacterial toxins inhibiting or activating small GTP-binding proteins.
AB - Amino acids located on the switch 1 or switch 2 domains of small GTPases of the
Ras and Rho family are targets of several bacterial toxins. Exoenzyme C3 from
Clostridium botulinum ADP-ribosylates specifically Rho at R43 and prevents the
recruitment of Rho on the cell membrane. This blocks the downstream effects of
the Rho GTPase. However, exoenzyme C3 is not a toxin, and chimeric proteins
fusing C3 with the B moiety of either diphtheria toxin or Pseudomonas aeruginosa
exotoxin A have been produced to intoxicate cells with low concentration of C3.
C. difficile toxin B modifies by glucosylation Rho on T37 and Rac and Cdc42 on
T35. Glucosylation of Rho, Rac, and Cdc42 blocks the binding of these GTPases on
their downstream effectors. C. sordellii lethal toxin modifies Ras, Rap, and Rac
on T35 by glucosylation. Cytotoxic necrotizing factor 1 (CNF1), from
uropathogenic Escherichia coli strains, deamidates Q63 of Rho into E63, thereby
blocking the intrinsic or GAP-mediated GTPase of Rho. This allows permanent
activation of Rho. Thus, Rho GTPases are targets for three different toxin
activities. Molecular mechanisms of these toxins are discussed.
PMID- 10667207
TI - Farnesyltransferase inhibitors. Preclinical development.
AB - The Ras proteins are low molecular weight GTP binding proteins that function in
the regulation of the transduction of growth proliferative signals from the
membrane to the nucleus. Oncogenically mutated ras genes are found in
approximately 25% of all human cancers. Localization of the Ras oncoproteins to
the inner surface of the plasma membrane is essential for their biological
activity. This observation suggested that the enzyme that mediates the membrane
localization, farnesyl-protein transferase (FPTase), would be a target for the
development of novel anticancer agents. We have developed potent, cell-active
inhibitors of FPTase that exhibit antiproliferative activity in cell culture and
block the morphologic alterations associated with Ras-induced transformation of
mammalian cells in monolayer cultures. In vivo, these compounds block the growth
of ras-transformed fibroblasts in a nude mouse xenograft model and block the
growth and, in some cases, cause regression of mammary and salivary tumors in
several strains of ras transgenic mice in the absence of any detectable side
effects. The results of our preclinical studies and those of others suggest that
FTIs may have utility against a variety of human cancers, a hypothesis that is
currently being tested in the clinic.
PMID- 10667208
TI - Selective inhibition of ras-transformed cell growth by a novel fatty acid-based
chloromethyl ketone designed to target Ras endoprotease.
AB - A novel fatty acid-based chloromethyl ketone, UM96001, which was designed to be a
Ras C-terminal sequence-specific endoprotease inhibitor, at low micromolar
concentrations (1-5.0 microM), potently inhibits ras-transformed rat kidney cell
growth, whereas the growth of untransformed normal rat kidney cells is not
affected under the same conditions. UM96001 almost completely blocks the
anchorage-independent clonogenic growth of ras-transformed rat and human cancer
cells at low micromolar concentrations. Inhibition of ras-transformed rat and
human cancer cell growth by UM96001 may occur via the mechanism of selective
induction of apoptosis of the cells. Furthermore, TPCK and BFCCMK, the known
selective inhibitors of Ras C-terminal sequence-specific endoprotease, also yield
similar inhibition results. These results provide the first experimental evidence
that the endoproteolysis of Ras oncoproteins may be important for Ras-mediated
cell growth and apoptosis. Therefore, the Ras C-terminal sequence-specific
endoprotease may be a potential anticancer target.
PMID- 10667209
TI - Azatyrosine. Mechanism of action for conversion of transformed phenotype to
normal.
AB - Azatyrosine [L-beta-(5-hydroxy-2-pyridyl)-alanine] has the unique property of
converting ras- or c-erbB-2 transformed phenotype to normal. The administration
of azatyrosine also inhibits tumor formation in transgenic mice harboring the
normal human c-Ha-ras which is mutated during treatment with various chemical
carcinogens. To elucidate the molecular mechanism, we investigated how
azatyrosine functions and what are its major targets. Azatyrosine functions
downstream of ras; azatyrosine does not alter either the level of GTP-bound Ras
or the total amount of Ras. Instead, azatyrosine inhibits the activation of c-Raf
1 kinase by oncogenic c-ErbB-2, resulting in inactivation of AP1. It is
interesting that azatyrosine also restores the expression of the rhoB gene, the
product of which regulates the formation of actin stress fibers. Azatyrosine is
incorporated into cellular proteins to replace tyrosine. Several experiments
indicate that replacement of tyrosine is likely to be a cause for its conversion
of transformed phenotype to normal. To prove this hypothesis, we are attempting
to develop a mutant of tyrosyl-tRNA synthetase that, unlike wild type, can
aminoacylate azatyrosine more efficiently than can tyrosine.
PMID- 10667210
TI - SCH 51344, an inhibitor of RAS/RAC-mediated cell morphology pathway.
AB - RAS interacts with multiple targets in the cell and controls at least two
signaling pathways, one regulating extracellular signal-regulated kinase (ERK)
activation and the other controlling membrane ruffling formation. These two
pathways appear to act synergistically to cause transformation. Human smooth
muscle alpha-actin promoter is repressed in RAS-transformed cells and derepressed
in revertant cell lines, suggesting that it is a sensitive marker to follow
phenotypic changes in fibroblast cells. SCH 51344 is a pyrazoloquinoline
derivative identified on the basis of its ability to derepress alpha-actin
promoter in RAS-transformed cells. Previous studies have shown that SCH 51344 is
a potent inhibitor of RAS transformation. However, SCH 51344 had very little
effect on the activities of proteins in the ERK pathway, suggesting that it
inhibits RAS transformation by a novel mechanism. Recently, we have demonstrated
that SCH 51344 specifically blocks membrane ruffling induced by activated forms
of H-RAS, K-RAS, N-RAS, and RAC. Treatment of fibroblast cells with this compound
had very little effect on RAS-mediated activation of ERK and JUN kinase
activities. SCH 51344 was effective in inhibiting the anchorage-independent
growth of Rat-2 fibroblast cells transformed by the three forms of oncogenic RAS
and RAC V12. These results indicate that SCH 51344 inhibits a critical component
of the membrane ruffling pathway downstream from RAC and suggest that targeting
this pathway may be an effective approach to inhibiting transformation by RAS and
other oncogenes.
PMID- 10667211
TI - Activation of apoptosis and its inhibition.
AB - The induction of apoptosis, or controlled cell death, by various stimuli has been
shown to activate a cascade of endoproteases, called caspases, that cleave
numerous cellular proteins necessary for cellular homeostasis. This review
discusses this family of proteases together with a variety of mammalian and viral
regulatory proteins that act to control this activation.
PMID- 10667212
TI - Strategies to adapt adenoviral vectors for targeted delivery.
AB - The utility of current generation adenoviral vectors for targeted, cell-specific
gene delivery is limited by the promiscuous tropism of the parent virus. To
address this issue, we have developed both genetic and immunologic methods to
alter viral tropism. Immunologic retargeting has been achieved via conjugates
comprised of an antifiber knob Fab and a targeting moiety consisting of a ligand
or antireceptor antibody. Gene delivery by this approach has been accomplished
via a variety of cellular pathways including receptors for folate, FGF, and EGF.
In addition to cell-specific gene delivery, this strategy has allowed enhanced
gene delivery to target cells lacking the native adenoviral receptor, CAR. Of
note, this specific and extended gene delivery allowed enhanced survival in
murine models of human carcinoma via cancer gene therapy. Genetic strategies to
alter adenoviral tropism have included both fiber modification and fiber
replacement. In the former, we have identified the HI loop of fiber as a
propitious locale for introduction of heterologous peptides. Incorporation of an
RGDC peptide at this locale allowed gene delivery via cellular integrins with
dramatic efficiency augmentations. As a strategy to achieve both new tropism as
well as to ablate native tropism, methods have been developed to replace the
fiber protein with heterologous motif which preserves the key trimeric quaternary
structure of fiber and allows for propagation. Such a fiber-replacement virus has
been rescued and has demonstrated capacities consistent with its utility as a
novel vector agent. These strategies have allowed the achievement of cell
specific gene delivery via adenoviral vectors and thus have the potential to
enhance the utility of this vector agent.
PMID- 10667213
TI - Homeodomain-derived peptides. In and out of the cells.
AB - The internalization of homeodomains and of homeopeptides derived from the third
helix of the homeodomain of Antennapedia, a Drosophila transcription factor, is
used by some investigators to target exogenous hydrophilic compounds into live
cells. In addition to this very practical aspect of drug delivery, translocation
across biologic membranes of peptides subsequently addressed to the cell
cytoplasm and nucleus raises several questions. A first series of questions
pertains to the mechanism of translocation. Thanks to the synthesis of several
peptides derived from the third helix of the Antennapedia homeodomain, we began
to investigate the mechanism of translocation and we have shown that it is not
dependent upon the presence of a chiral receptor and probably involves the
formation of inverted micelles. A second series of questions is related to the
physiologic significance of the phenomenon. In a first approach, we demonstrated
that some full-length homeoproteins are internalized and secreted in vitro. The
mechanism of internalization is probably similar to that of the homeodomain or of
its third helix, but secretion involves a different mechanism which requires an
association with specialized intracellular membranous structures. The existence
of specific mechanisms for homeoprotein internalization and secretion suggests
that this class of transcription factors may have important signaling properties.
PMID- 10667214
TI - In vitro evaluation of a novel 2,6,9-trisubstituted purine acting as a cyclin
dependent kinase inhibitor.
PMID- 10667215
TI - Homologous recombination between heterologs during repair of a double-strand
break. Suppression of translocations in normal cells.
PMID- 10667216
TI - Selection of genetic suppressor elements conferring resistance to DNA
topoisomerase II inhibitors.
PMID- 10667217
TI - BAP1, a candidate tumor suppressor protein that interacts with BRCA1.
PMID- 10667218
TI - Histone deacetylase inhibitor activates the p21/WAF1/Cip1 gene promoter through
the Sp1 sites.
AB - Trichostatin A (TSA), a specific histone deacetylase inhibitor, induces histone
hyperacetylation and modulates the expression of some genes. We examined the
effects of TSA on MG63 cells. TSA induced growth arrest and expression of the
p21/WAF1/Cip1 protein. A close correlation between the level of histone
acetylation and induction of the p21/WAF1/Cip1 protein was detected. Using
several mutant p21/WAF1/Cip1 promoter fragments, mutation of either of two Sp1
sites at -82 or -69 of the p21/WAF1/Cip1 promoter reduced the responsiveness to
TSA. This finding indicates that TSA activates the p21/WAF1/Cip1 promoter through
the Sp1 sites in a p53-independent manner.
PMID- 10667219
TI - Selective induction of cyclin-dependent kinase inhibitors and their roles in cell
cycle arrest caused by trichostatin A, an inhibitor of histone deacetylase.
PMID- 10667220
TI - Identification of a novel nuclear export signal sensitive to oxidative stress in
yeast AP-1-like transcription factor.
PMID- 10667221
TI - Melanoma cell lines contain a proteasome-sensitive, nuclear cytoskeleton
associated pool of beta-catenin.
PMID- 10667222
TI - Truncated form of beta-catenin and reduced expression of wild-type catenins
feature HepG2 human liver cancer cells.
PMID- 10667223
TI - Induction of apoptosis by gelsolin truncates.
PMID- 10667224
TI - Reexpression of the major PKC substrate, SSeCKS, correlates with the tumor
suppressive effects of SCH51344 on rat-6/src and rat-6/ras fibroblasts but not on
rat-6/raf fibroblasts.
PMID- 10667225
TI - Subtractive cDNA cloning and characterization of genes induced by all-trans
retinoic acid.
PMID- 10667226
TI - Purification and functional characterization of a novel protein encoded by a
retinoic acid-induced gene, RA28.
PMID- 10667227
TI - Augmented inhibition of tumor cell proliferation in combined use of
electroporation with a plant toxin, saporin.
PMID- 10667228
TI - Expression of matrix metalloproteinases and their inhibitors in human brain
tumors.
AB - Sixty human brain tumors, including grade I meningiomas, schwannomas, and
pilocytic astrocytomas, grade II astrocytomas, grade III anaplastic astrocytomas
and oligodendrogliomas, and grade IV glioblastomas and lung and melanoma
metastases were analyzed for expression of four matrix metalloproteinases (MMPs),
two tissue inhibitors of MMPs (TIMPs), and MMP activity. No marked correlation
was found between MMP expression and the degree of malignancy. Western blotting
analysis revealed a more uniform pattern of distribution of MMP-2 (gelatinase A)
than of MMP-9 (gelatinase B) and MMP-12 (metalloelastase) among tumors. All 60
tumors showed a similar pattern of activity in zymography, MMP-2 being the major
species detected. Interestingly, TIMP-1 and TIMP-2 expression levels were low in
tumors of grade III but significantly higher in tumors of grade I, particularly
schwannomas. Altogether, these data suggest that: (1) the balance between MMP-2
and TIMP-2 is important in human brain tumors; and (2) TIMP expression may be a
valuable marker for tumor malignancy.
PMID- 10667229
TI - Plasmin-depletion therapy. A new approach to overcoming tumor cell drug
resistance.
PMID- 10667230
TI - Polysulfated heparinoids selectively inactivate heparin-binding angiogenesis
factors.
AB - Angiogenesis is a prerequisite for tumor expansion and metastasis. The angiogenic
potential of the heparin-binding growth factors acidic fibroblast growth factor
(FGF) and basic FGF has been demonstrated in various publications. We studied the
inhibitory effects of suramin and the polysulfated heparinoids pentosan
polysulfate, dextran sulfate, and fucoidan on the action of FGF. As an
experimental model, we used the adrenal cancer cell line SW 13, whose anchorage
independent growth depends on the presence of FGF. The polysulfated heparinoids
inhibited FGF-induced growth and binding to the receptor at an IC50 of 0.5-3
micrograms/ml. Suramin inhibited FGF at an IC50 of 100 micrograms/ml. The
polysulfated heparinoids exerted no effect on IGF-1 or TGF alpha-related growth.
Suramin inhibited the anchorage-independent growth induced by IGF-1 or TGF alpha
only at an IC50 of 100 micrograms/ml. Our results indicate that suramin inhibits
growth factors in a nonselective way. By contrast, polysulfated heparinoids exert
a selective inhibitory effect on heparin binding angiogenesis factors at an IC50,
which is 100 times below the IC50 of suramin. Therefore, the administration of
polysulfated heparinoids might become a novel approach to tumor therapy based on
blocking angiogenesis.
PMID- 10667231
TI - RPR 130401, a nonpeptidomimetic farnesyltransferase inhibitor with in vivo
activity.
PMID- 10667232
TI - Cellular effects of a new farnesyltransferase inhibitor, RPR-115135, in a human
isogenic colon cancer cell line model system HCT-116.
PMID- 10667233
TI - The farnesyltransferase inhibitor L-744,832 inhibits the growth of astrocytomas
through a combination of antiproliferative, antiangiogenic, and proapoptotic
activities.
PMID- 10667234
TI - Isolation of farnesyltransferase inhibitors from herbal medicines.
PMID- 10667235
TI - Farnesyltransferase inhibitor-induced regression of mammary tumors in TGF alpha
and TGF alpha/neu transgenic mice correlates with inhibition of map kinase and
p70s6 kinase phosphorylation.
PMID- 10667236
TI - Inhibition of protein tyrosine kinase activity by 1a-docosahexaenoyl mitomycin C.
PMID- 10667237
TI - Activation of a 36-kD MBP kinase, an active proteolytic fragment of MST/Krs
proteins, during anticancer drug-induced apoptosis.
PMID- 10667238
TI - Peptides mimicking sialyl-Lewis A isolated from a random peptide library and
peptide array.
PMID- 10667239
TI - B4112, a novel tetramethylpiperidine-substituted phenazine that inhibits the
proliferation of multidrug-resistant cancer cell lines.
PMID- 10667241
TI - Construction of a cell-permeable CDC42 binding fragment of ACK that inhibits v-Ha
Ras transformation.
PMID- 10667240
TI - The anti-RAS cancer drug MKT-077 is an F-actin cross-linker.
PMID- 10667242
TI - Rational development of cell-penetrating high affinity SH3 domain binding
peptides that selectively disrupt the signal transduction of Crk family adapters.
Amgen Peptide Technology Group.
PMID- 10667243
TI - Anti-HER2 immunoliposomes for targeted drug delivery.
PMID- 10667245
TI - Management of head and neck tumors: what are the challenges for the third
millennium? Abstracts.
PMID- 10667247
TI - Cumulative author and subject index for volumes 1-13.
PMID- 10667244
TI - Recombinant cytotoxins specific for cancer cells.
PMID- 10667249
TI - The Physiologic Society proceedings of the scientific meeting held at University
of Glasgow, 14-16 September 1999. Abstracts.
PMID- 10667246
TI - 10th International Dresden Symposium on Lipoproteins and Atherosclerosis.
Dresden, Germany, 9-11 December 1999. Abstracts.
PMID- 10667251
TI - Cumulative 22-year index, volumes 1-22, 1978-1999.
PMID- 10667250
TI - Ten-year cumulative index, volumes 1-10, 1990-1999.
PMID- 10667252
TI - International Society of Psychoneuroendocrinology (ISPNE) XXXth Congress.
Orlando, Florida, USA. 30 July-3 August 1999. Abstracts.
PMID- 10667248
TI - International Society for Heart and Lung Transplantation 20th annual meeting and
scientific sessions. Osaka, Japan, April 5-8, 2000. Abstracts.
PMID- 10667253
TI - ESTRO-EORTC meeting on Radiation for Benign Disease: Current Status and Possible
Perspectives. Brussels, Belgium, 10-13 October 1999. Abstracts.
PMID- 10667254
TI - [Consensus on the management of obesity, Switzerland 1999].
PMID- 10667256
TI - Bibliography of toxinology.
PMID- 10667255
TI - V Symposium of the Brazilian Society on Toxinology. Understanding and exploiting
toxins for the XXI century. Angra dos Reis, Rio de Janeiro, Brazil. 13-18
September 1998. Abstracts.
PMID- 10667257
TI - Master index to volumes 71-80.
PMID- 10667258
TI - [Anthropometric characteristics of obese women before and after weight
reduction].
AB - Anthropometric changes in 53 premenopausal obese women, 25-45 year-old, after an
obesity treatment, were analyzed. Before and immediately after treatment, midarm,
abdomen, waist, hip, midthigh and midcalf circumferences, as well as tricipital,
bicipital, suprailiac, subscapular, abdominal and calf skinfold thickness were
measured. The later averaged over percentil 75th. All final measurements, except
midcalf circumference, abdomen/waist and hip/midthigh indexes, were significantly
lowers as compared with the initial values. Body weight decreased on average 8.9
kg, and skinfold thickness mean fell below the 75th percentile. Percentage body
fat decreased 18.3%, and body mass index 11%. Initial principal component
analysis results, exhibited three chief characteristics of obesity: general
adiposity; trunk vs. extremity fatness, and upper vs. lower fatness. Body fat
distribution pattern and body composition were modified as a result of the
treatment. Therefore, the morbidity risk associated with them, was substantially
reduced.
PMID- 10667259
TI - [Maternal height and growth of Chilean premature infants].
AB - The aim of this study was to analyze the association between maternal age and
growth of infants born preterm through the first 4 mo. of age. We prospectively
studied 80 infant born at the hospital Herminda Martin in Chilean between January
and September 1995 with birthweight < 2500 g and gestational age < or = 36 weeks;
those born small for date, with congenital malformations or developing chronic
diseases were excluded. The modified Graffar was applied to study socioeconomic
status and growth, morbidity and type of feeding was monthly registered at
Primary Care Centers where they were controlled. The maternal height was
categorized as small (< -1 SD, n = 14), normal (> -1 SD and < +1 SD, 147.6-161.8
cm, n = 52) or tall (> +1 SD, n = 14). Sons from tall mothers presented better
W/A z score at 4 mo than those from normal or small mothers (0.85 +/- 0.8 vs 0.31
+/- 0.6, p < 0.03 and 0.85 +/- 0.8 vs 0.15 +/- 0.8, p < 0.04). Length gain
through the 4 mo was also better of infants with tall mothers (15.3 +/- 1.4 vs
13.7 +/- 2.3 and 13.6 +/- 2.2 cm, ANOVA p < 0.04), reaching better z-scores (0.2
+/- 0.3 vs -0.7 +/- 0.6 and -0.9 +/- 0.9, ANOVA p < 0.0001). The maternal
schooling > 8 y was also associated to infant growth: those with tall mothers
presented better L/A z-score at 4 mo than those with normal or small mothers
(0.27 +/- 0.3 vs -0.89 +/- 0.7 and -0.85 +/- 0.5 p < 0.001). Exclusive breast
milk was present in 7% of tall, 25% of normal and 0% of small mothers. No
differences in morbidity were observed between groups. We conclude that Chilean
infants born preterm from mothers > 1.61 m present a better growth that those
with smaller mothers since the first 4 months of age.
PMID- 10667260
TI - [Nutritional study relative to proteins, energy, and calcium in children eating
school meals].
AB - Food consumption and nutritional status were evaluated on 419 children having
meals at school located in the surrounding of Santa Fe (Argentina). The protein,
energy and calcium content of the meals were analyzed. Anthropometrical
evaluation was made by the following indicators: weight to age, height to age and
weight to height. Biochemical evaluation to a sample of the children, was made by
urea/creatinine and calcium/creatinine indicators. Recommended protein
consumption is achieved but a biological efficiency loss is detected, probably
due to an insufficient energy intake. School meals provide about 50% of the daily
energy requirements. Regarding calcium consumption, the dinner cover about 15% of
the recommendations but they achieve 47-49% with the cup of milk. As in the case
of energy, the calcium daily intake is insufficient as we can see by the
calcium/creatinine indicator which shows that a 60% of the people are below of
the normal values. All these results suggest that is necessary to increase the
energy intake and calcium consumption to improve the nutritional status.
PMID- 10667261
TI - [Effect of breast feeding and psychosocial variables upon psychomotor development
of 12-month-old infants].
AB - This study evaluates the participation of psychosocial variables in the relation
between breast feeding (BF) and psychomotor development (PMD) in dyads with
different BF duration. We assessed 138 mother-infant dyads, divided in two
groups: 86 received BF as unique source of milk feeding for at least 6 months
(prolonged BF group) and 52 were weaned before 45 days of age (early weaning
group). General information about pregnancy, delivery and feeding was collected
in a non experimental prospective design. At 6-7 months of age a milk feeding
situation was observed at home, and mother-infant interactional patterns were
recorded through a specially designed scale. At 12 months of age the PMD was
assessed (Bayley Scales of Infant Development). Infant temperament, home
stimulation, mother depression and family stress were also measured. Similar
family characteristics were observed in both study groups. Early bonding and
first feeding experiences were different, both reported as better in the
prolonged BF group. Moreover, dyads of this group showed a higher variety and
quality of mother-infant interactional patterns during feeding, with a higher
synchrony and reciprocity in the relationship. Mean Mental Development Index
(MDI) and Psychomotor Developmental Index (PDI) were similar in both groups.
Explicatory variables for MDI and PDI are different in both study groups. Dyads
who attained prolonged BF conform from a psychosocial perspective--a different
group than the early weaned.
PMID- 10667262
TI - [Basal metabolic rate is overestimated by predictive equation in college-age
women of Rio de Janeiro, Brazil].
AB - Since the World Health Organization suggested predictive equations for basal
metabolic rate (BMR) in 1985 there has been great interest in their validity in
different populations worldwide. It has been shown that these equations
overestimate BMR in some populations, particularly the ones living in the
tropics. There is limited new information on BMR in segments of the Brazilian
population. Therefore, the aim of the present study was to compare measured with
estimated BMR using some published predictive equations in 50 college students
from Rio de Janeiro, Brasil. BMR was measured by indirect calorimetry and the
predictive equations used were the ones published by: FAO/WHO/UNU (1985); Harris
& Benedict (1919), and Henry & Rees (1991). Estimated BMRs were significantly
greater than measured BMR (p < 0.05). Overestimation was greatest with the
equation published by Harris & Benedict (18.9%) followed by the ones by
FAO/WHO/UNU (12.5%) and Henry & Rees (7.2%). Body composition did not correlate
with the overestimation of BMR. More data are necessary so that appropriate
predictive equations can be developed for the Brazilian population.
PMID- 10667263
TI - [Erythrocyte protoporphyrin during recovery from malnutrition in rats].
AB - Interrelationships between Erythrocyte Protoporphyrin (EP), dietary Iron/Protein
ratio (Fe/Prot) and Fe liver content (Feh) were studied during nutritional
recovery in an experimental model: weanling female Wistar rats (To) were depleted
with a protein-free diet (LP), losing 20% of their initial body weight. Then they
were recovered until 45 days of age (T45) with diets containing: casein: 20 g/100
g; Fe (ammonium Fe citrate) (ppm.): 0, 75 or 100 (groups A1, A2 and A3,
respectively). Hematocrit, Hemoglobin (Hb) (g/dL). Erythrocyte Protoporphyrin
(EP) (microgram/dL Red Blood Cells) and Feh (microgram) were determined at To, LP
and T45. Results were compared with control rats (C) fed with 20% of casein and
Fe, 50 ppm. EP: a) decreased in C from To to T45 (99 +/- 24; 36 +/- 9; p < 0.01);
b) increased in A1 and A2 at T45 (123 +/- 21; 93 +/- 29, respectively, p < 0.01)
while A3 did not show significant difference (45 +/- 7) regarding to C: c)
correlated inversely with Feh. According to the inverse correlation between EP
and Fe/Prot (r = -0.99), we found that 92 ppm was an adequate Fe amount to
prevent EP increase. These results confirm that during recovery from
undernutrition EP depends on iron liver content, being an adequate indicator of
iron nutritional status; therefore, EP would be useful as a predictor of the
optimum Fe/Prot ratio for nutritional recovery.
PMID- 10667264
TI - [Rural development, household food safety, and nutrition in western Honduras].
AB - The authors studied the impact of a rural development project on household food
security and nutrition. A quasi-experimental study design was used to compare the
experience of members of thirteen Honduran small-holder farmers groups which had
already received a year of credit and technical assistance, with another thirteen
groups which had just joined the project, and thirteen control communities. All
these communities were followed-up for one year (March/April 1997-March/April
1998). Farmers participating in the project showed a greater increase in maize
stores than farmers in the control communities (p = 0.01), but did not increase
their dietary energy consumption. There was, however, a small improvement in
their dietary diversity (p = 0.01). The impact of the project on the nutritional
status of under 5's was complex. The study underlined the importance of
monitoring the impact of programs which may affect food and nutrition.
PMID- 10667265
TI - [Evaluation of cookies enriched with corn germ and soy fiber].
AB - The objective of this study was to evaluate four cookie formulations which wheat
flour was partially substituted by free-fat corn germ flour and/or soy fiber.
Baking quality, protein, fat, ash, dietary fiber, hardness, color, Protein
Efficiency Ratio PER and Apparent Digestibility in vivo were determined. A
trained panel evaluated color, hardness and fracturability of cookies. Dietary
fiber of cookies varied from 8.2 to 24.9% and protein from 11.3 to 12.7%. The
source and amount of dietary fiber modified physical, sensory, and nutritional
properties of cookies. Cookies formulated with 20% corn germ flour gave the
highest PER, Digestibility Aparente in vivo, and acceptance by consumers. This
study demonstrated the potential use of free-fat corn germ and soy fiber as
functional ingredients.
PMID- 10667266
TI - Nutritional evaluation of table bread fortified with defatted soybean and sesame
meals.
AB - The nutritional value of table bread fortified with 8% defatted soybean meal
(DSBM), 12% DSBM and a mixture of 8% DSBM/4% defatted sesame meal (DSM) was
assessed with in vivo and in vitro tests. Fortification with DSBM and DSM
decreased protein digestibilities (P < 0.05) but improved essential amino acid
scores (EAA) and overall nutritional value of the breads. Fortified breads
contained twice as much lysine, and consequently a better protein efficiency
ratio (PER) than the control bread. The PER of the 8% DSBM/4% DSM bread was
similar (P > 0.05) to the 12% DSBM bread. The 8% DSBM fortified bread showed
lower PER, amino acid and protein contents than breads fortified with 12% DSBM.
In vitro procedures utilized to predict protein digestibilities and PER's
provided a close estimation of in vivo results obtained from growing rats.
PMID- 10667267
TI - [Sensory characterization of pate from waste salmon (Salmo salar L.) products
utilizing response surface methodology].
AB - The goal of the present study was the development of a salmon pate formulation
with excellent nutritional and sensory properties, using by product components
from de salmon industry. The optimized formulation was obtained using the
response surface methodology. A 2n factorial and a composite central rotatable
design was applied in the experience. Salt and xanthan hydrocolloid gum were the
selected independent variables and sensory quality the response variable.
Statistical analysis was utilized to estimate the fitted model. The optimum
combination of selected experimental variables were 1.5% salt and 1.35% xanthan
gum. Data from the chemical characterization of salmon pate showed an important
protein content (20%) greater than liver pate (11.5%) and trout pate (14.7%).
With regard to fat content, the concentration of this component in salmon pate
was half the concentration found in liver pate. The shelf life of the optimized
formula determined at 3 degrees C and 18 degrees C were 18 days and 8 days
respectively.
PMID- 10667268
TI - Antioxidant concentration effect on stability of Brazil nut (Bertholletia
excelsa) crude oil.
AB - Shelled and broken Brazil nuts easily lose quality, if not properly stored.
Pressing is an alternative use of these nuts and the crude oil stability was
studied. Our previous studies demonstrated that TBHQ (200 mg kg-1) was very
efficient to prevent rancidity development in oils bottled in brown and clear
glass. As TBHQ has higher price than other phenolic antioxidants like BHT and
BHA, an oven test (at 63 degrees C) was conducted to determine the economical and
best concentration of TBHQ for Brazil nut crude oil. An assay at ambient
temperature was conducted in brown and clear glass flasks with and without the
economical concentration of TBHQ calculated (83 mg kg-1) for 90 days. Acid,
peroxide, and iodine indices and the absorptivity at 232 nm were determined.
TBHQ, even at this low dosage, was very efficient in both brown and clear glass
flasks. Peroxide value increased from 11.5 meq O2 kg-1 to average 15 and 35, in
TBHQ and control samples after 90 days. The absorptivity at 232 nm remained at
1.3 in samples with TBHQ while the control increased to 1.6.
PMID- 10667269
TI - [Presence of Clostridium perfringens in meat-based preparations in public food
services in central San Jose, Costa Rica].
AB - In Costa Rica there are a large number of public food services distributed along
the country, where a considerable number of people eat daily. Clostridium
perfringens is a bacteria associated with foodborne illness related, especially,
to meat products kept for long time at temperatures under 70 degrees C. The aim
of this study was to evaluate the public food services that use water baths for
keeping food hot in order to establish the presence of C. perfringens in cooked
bovine meat dishes and to evaluate the enterotoxigenic capacity of the strains
isolated. 81 samples of cooked bovine meat plates coming from 27 public food
services, located in the Central County of San Jose were analyzed. The
methodology described by Labbe & Harmon for the isolation of C. perfringens was
used in 10 g of sample. Also, the enterotoxigenic capacity of the strains was
evaluated using the passive-reverse-latex-agglutination assay from Oxoid. From
the 27 public food services analyzed, eight (30%) were positive in the three
samplings done, nine (33%) were positive in one or two occasions, and ten (37%)
were negative all times. This implies that in 17 (63%) of the establishments
studied, the bacteria was isolated at least once. From the 81 preparations
studied, 37 (46%) were positive for the bacteria. The temperatures at which food
was kept varied from 56 to 82 degrees C, with an average of 68.7 degrees C. From
the 37 strains identified as C. perfringens, 12 (32%) were positive for
enterotoxin. In conclusion, the presence of C. perfringens in bovine meat dishes,
maintained in water baths, represents an important risk for public health, and
the temperature at which the preparation is kept is critical for the
multiplication of the bacteria.
PMID- 10667270
TI - [Determination of clostridium perfringens in pork sausages from the Metropolitan
area of Costa Rica].
AB - The presence of C. perfringens was analyzed in 75 samples of pork sausages
(chorizo, salchichon and bologna), obtained from five processing plants located
in the Metropolitan Area of Costa Rica. Previously and after the biochemical
identification of the strains, the most probable number (MPN) of C. perfringens
per gram of food was determined and it varied from less than 3 to more than 2.4 x
10(5). There were significant statistical differences (p < 0.005) that support
the need of employing biochemical tests for confirming C. perfringens in a given
food. C. perfringens was present in 92% of the chorizos, in 28% of the bolognas
and in 12% of the salchichon. Every positive sample was tested looking for at
least one enterotoxigenic strain, using the reverse passive agglutination latex
test; 8% of the tested strains were enterotoxigenic and corresponded to chorizo
and bologna from one processing plant and chorizo from another plant. The results
obtained in this study show that pork sausages, and not just not processed meats,
are important as risk factors for food intoxication by C. perfringens.
PMID- 10667271
TI - Physical-chemical composition of in natura goat milk from cross Saanen throughout
lactation period.
AB - The analyzed milk samples were collected from cross Saanen goats of different
ages and different cross breeding types, throughout the lactation period, from
September 1996 to December 1997. For the physical-chemical characteristics
measured in this experiment, the following average values were obtained, followed
by their respective standard deviations: pH (6.69 +/- 0.20); acidity (12.96 +/-
3.64 degrees D); density (1.030 +/- 0.009 mg.cm-3); fat (3.83 +/- 1.04%); crude
protein (3.34 +/- 0.73%) and total solids (12.25 +/- 1.94 g.100 g-1). The
lactation period influenced the values of acidity, fat, crude protein and total
solids; these values decreased during the initial months and increased at the end
of the lactation. The correlations were analyzed among the studied
characteristics during the lactation, resulting in positive (p < 0.05)
acidity/density correlation (r = 0.2115), stand out also the positive
correlations (p < 0.01) among fat/total solids (r = 0.7715) and crude
protein/total solids (r = 0.6228).
PMID- 10667272
TI - [Iron, zinc and copper content of foods commonly consumed in Mexico].
AB - Nutrient composition in foods is necessary for the determination of nutrient
intake. Food composition tables used for dietary studies in Mexico do not have
information of zinc, iron and copper; when present the values have been
extrapolated from laboratory analysis carried out with foods in other countries
and regions of the world. In this study zinc, iron, and copper content of 104
plant foods and 32 animal foods was determined. The procedure used was atomic
absorption spectrophotometry for the minerals. Foods were grouped into cereals,
vegetables, fruits, legumes and animal foods. Zinc content ranged from 0.018
mg/100 g for strawberry to 9.193 mg/100 g for beef. Iron content ranged from
0.113 mg/100 g for yogurt to 19.82 mg/100 g for a commercial cereal which had
minerals added during processing. In some foods copper was not found and the
highest content was 3.371 mg/100 g in beef liver. This study has provided
information on zinc, iron and copper content of the most commonly consumed foods
in Mexico.
PMID- 10667273
TI - Lipids and fatty acids in roasted chickens.
AB - Total lipids from meat portions of breast, thigh, wing, side and back with and
without skin from 10 roasted chickens were extracted with chloroform and methanol
and gravimetrically determined, and their fatty acids were analysed as methyl
esters by gaseous chromatography, using a flame ionization detector and capillary
column. The main fatty acids found were: C16:0, C18:1 omega 9, and C18:2 omega 6.
The average ratio observed between PUFA/SFA was of 0.98, mainly due to the great
concentration of the C18:2 omega 6 fatty acid, with an average of 26.75%.
Regarding to the lipids content, the skinless breast showed the lowest content,
0.78 g/100 g, while the back with skin was the one with the highest content,
12.13 g/100 g except for the pure skin, with 26.54 grams of lipids by 100 grams.
PMID- 10667274
TI - Immunological alterations in patients with primary tumors in central nervous
system.
AB - Natural killer (NK) cells play an important role in immune surveillance against
tumors. The present work aimed to study the cytotoxic activity of NK cells and T
cell subsets in peripheral blood of 13 patients with primary tumors in central
nervous system (CNS). As controls 29 healthy subjects with the age range
equivalent to the patients were studied. The methods employed were: a)
determination of cytotoxic activity of NK cells towards K562 target cells,
evaluated by single cell-assay; b) enumeration of CD3+ lymphocytes and their CD4+
and CD8+ subsets defined by monoclonal antibodies; c) the identification of
tumors were done by histologic and immunochemistry studies. The results indicated
that adults and children with tumor in CNS display reduced percentage of total T
cells, helper/inducer subset and low helper/suppressor ratio. The cytotoxic
activity of NK cells was decreased in patients with CNS tumors due mainly to a
decrease in the proportion of target-binding lymphocytes. These results suggest
that cytotoxic activity of NK cells may be affected by the immunoregulatory
disturbances observed in patients with primary tumors in CNS.
PMID- 10667275
TI - The Kohs' blocks test as an important instrument to investigate the visuo-spatial
impairments in myotonic dystrophy. Part I. Quantitative and qualitative analysis.
AB - This study presents the performance of 39 cases of myotonic dystrophy on Kohs'
blocks test (21 females and 18 males, age range from 9 to 70 years). On this
test, the patients have to reproduce figures from models previously showed to
them. Some of the patients had some kind of professional activity, while others
had never exerted a professional occupation. The patients denoted considerable
difficulty to perform the test. Some cases constructed entirely different figures
in comparison to the presented drawings, translating visuo-spatial and
constructional disabilities. The performance was insufficient in 71.4% of the
cases. These cases solved less than 50% of the test. The levels of analysis and
synthesis were severely impaired. A total of 18 cases got less than 10 points,
not reaching 20% of the test. The results showed the sensitivity of this test in
detecting visuo-spatial impairment in myotonic dystrophy.
PMID- 10667276
TI - Sleep characteristics in children in the isolated rural African-Brazilian
descendant community of Furnas do Dionisio, State of Mato Grosso do Sul, Brazil.
AB - Developmental and cultural factors affect sleep habits in childhood. The
objective of this research was to determine sleep habits of children in the
isolated rural African-Brazilian community of Furnas do Dionisio. Mato Grosso do
Sul, Brazil. The members of this community are closely related descendants of the
ex-slave Dionisio, and remained in relative geographical isolation for about a
century. Sleep characteristics of 55 children (35 M; 20 F), 2 to 10 year olds,
were evaluated in interviews with their mothers. The results showed that
cosleeping, in the same bed with family members, was present in 80.0% of the 2-3
year olds; decreasing to 25.0% of the 8-10 year olds. Only 5.4% of the children
slept alone in their own bedroom. Mean number of persons per bedroom was 2.8.
Only 7.0% of the bedrooms had TV; 98.1% slept in silence. The data obtained
support the need to weigh cultural factors influence on sleep.
PMID- 10667277
TI - A case-control study of a benign electroencephalographic variant pattern.
AB - Wicket spikes (WS) are a benign electroencephalogram (EEG) variant, seen mainly
in adults, during somnolence, in the temporal regions, in many clinical
situations. WS can appear in trains or isolatedly, sometimes being difficult to
differentiate from epileptiform activity. We reviewed 2,000 EEG's, found 65 with
WS (3.25%) and compared them with 65 normal EEG without WS. There was
statistically significant (SS) association between WS and age over 33; adolescent
age was correlated to absence of WS and age over 65, to the presence of WS; there
was an inverse correlation between WS and epilepsy, related to differences in
age; a SS association with cerebrovascular disorders disappeared after
controlling for age; a SS correlation with headache was also related to age;
female predominance was not SS. There was a great variety of clinical situation
associated with WS. We conclude that WS are a inespecific normal variant of the
EEG that is age-related.
PMID- 10667278
TI - Continuous spike-waves during slow waves sleep. A clinical and
electroencephalographic study in fifteen children.
AB - We report on the clinical and EEG features of 15 patients with the syndrome of
"continuous spike waves during slow wave sleep" (CSWSS). The differential
diagnosis of CSWSS includes benign epilepsy of childhood with centro-temporal
spikes, and Landau-Kleffner and Lennox-Gastaut syndromes. We found normal CT and
MRI features in 6 cases, periventricular leukomalacia with and without diffuse
brain atrophy in 4 cases and hydrocephalus in 1 case. There was no association
between specific neurological findings and CSWSS. Nine of our cases had
relatively focal discharges, like some cases from the literature. The occurrence
of CSWSS appears to be age-related, generally between the ages of 5 to 12 years,
with a strong temporal relation to the neuropsychological deterioration in its
nature, severity and prognosis. We believe that this striking disorder has been
overlooked and that routine sleep EEG studies on epileptic children may disclose
additional cases of CSWSS.
PMID- 10667279
TI - [Video-polygraphic-EEG study in the full-term newborn with low birthweight for
their gestational age].
AB - Video-polygraphic-EEG studies were performed in the first 24 life-hours of 26
healthy full-term newborns without perinatal injuries. The neurological
examination and cranial ultrasonography were normal. The newborns were divided
into two groups: one, with full-term appropriate--birth weight 11 newborns
(control group) and the other with full-term low-birth weight 15 newborns.
Thirteen newborns of the second group had video-polygraphic-EEG study
abnormalities. The most frequent abnormalities were found in 11 cases, as far as
sleep architecture is concerned. Also, when compared with the control group, 8
cases of an excessive amount of startles and 2 cases of low behavior activities
were found. The results demonstrate the usefulness of video-polygraphic-EEG study
in the full-term newborns with intra-uterine growth retard. This examination was
sensitive to detect behavior, sleep architecture and EEG standard differences in
the low birth-weight newborns as to the control group.
PMID- 10667280
TI - [Electroencephalographic modification in Down syndrome].
AB - The frequency of epilepsy in Down syndrome (DS) has been reported in literature
varying from 6 to 17%. A typical electroencephalographic (EEG) pattern has not
been established for this condition. There is a great variation on EEG
abnormalities and most of them are not associated to behavior alterations or
neurological signs. The aim of this study was to establish epidemiological and
electroencephalographic parameters in institutionalized patients with clinical
diagnosis of DS. We studied 77 individuals of both sexes, age ranging from 0-38
years old. The EEG was performed on all the patients; 20.7% had EEG abnormalities
and 31.3% of these were epileptic. The non-epileptic patients presented
inespecific EEG abnormalities. Therefore, our data did not allow us to propose a
typical EEG pattern for DS.
PMID- 10667281
TI - [Cerebrovascular disease in children: I. Epileptic manifestations].
AB - Seizures may occur as a complication of cerebrovascular disease (CVD) and its
prevalence, clinical presentation, risk factors and evolution have been reported
by few authors. We evaluated 39 children with CVD and analyzed the association
with seizures. Seizures occurred in 24 (61.5%) patients and were classified as
partial (29.2%), generalized (54.2%) and secondarily generalized (16.6%). Infants
had a significantly higher prevalence of seizures (p = 0.0362) than children at
other ages. Cortical localization was associated with a significantly higher
prevalence of seizures (p = 0.0101). There were no differences between ischemic
and hemorrhagic strokes. Fourteen patients had no seizures after the acute phase
of the CVD, the 2 previously epileptic patients had their seizures controlled
with antiepileptic drugs, 3 developed epilepsy, 2 died during the acute phase and
in 3 patients there was not enough time yet to make a clear diagnosis of
epilepsy.
PMID- 10667282
TI - [Cerebrovascular disease in children: II. Clinical aspects in 42 cases].
AB - We report the findings recorded in 42 children suffering cerebrovascular disease
and assisted at the Hospital das Clinicas FCM-UNICAMP, over a 8 years period
(January 1990 until April 1998). The ischemic type was the most common, and
involvement of the middle cerebral artery, sudden onset of clinical manifestation
with seizures and motor disability were more common in early aged children. Motor
sequelae predominated in the follow-up of these children.
PMID- 10667283
TI - [Use of amitriptyline in attention deficit hyperactivity disorder].
AB - We studied the action of amitriptyline (AMI) in the attention deficit
hyperactivity disorder (ADHD). Twenty-five children who came to consultation for
ADHD were analyzed, in two groups: the group which used AMI (n = 18) at 1.6
mg/kg/day and the group which used placebo (n = 7). Both groups were submitted to
two assessments in a 30 days interval, which consisted of the evolutive
neurological evolution examination (ENE) and the WISC scale subtests on numbers,
drawings to be completed and the code. The results showed that the AMI produced
an improvement in performance in the motor persistence tests.
PMID- 10667284
TI - [Intravenous lysine clonixinate for the treatment of migraine: an open pilot
study].
AB - Several oral nonsteroidal anti-inflammatory drugs (NSAID) are effective to treat
migraine attacks. Despite its efficacy to treat migraine and other pain, there
are a few commercial NSAIDs available for intravenous (i.v.) administration.
Lysine clonixinate (LC) is a NSAID derived from nicotinic acid that has been
proven effective in various algic syndromes such as renal colic, nerve
compression, muscular pain and odontalgias. The aim of this study was to evaluate
the efficacy of the i.v. LC in the treatment of severe attacks of migraine. We
studied prospectively 19 patients, 17 women and 2 men, ages from 18 to 57 years,
with the diagnosis of migraine according to the International Headache Society
criteria. The patients were oriented to proceed to the clinic once the headache
has started, and were placed under an i.v. infusion of LC and saline in a
superficial vein of the forearm, once the intensity reached severe. Evaluating
the headache intensity after 30, 60 and 90 minutes, as well as the presence of
side effects, we observed that all of the 19 patients were headache free after 90
minutes. Some patients presented mild adverse effects and the vital signs were
not significantly affected. We then concluded that the i.v. infusion of the NSAID
LC (2-3-chloro-o-toluidin)piridin-3-lysine carboxilate), a derived from the
nicotinic acid with a chemical structure that resembles the flufenamic acid, was
efficient abolishing a severe migraine attack after 90 minutes in 19 patients.
Controlled studies with a double-blind and randomized design, and treating a
greater number of patients and attacks are necessary to confirm these initial
observations.
PMID- 10667285
TI - [Clinical and therapeutical features in 135 patients with dystonia: experience of
movement disorders unity of the Hospital de Clinicas of the Universidade Federal
do Parana].
AB - This study aims to describe the clinical patterns and therapeutic responses in
135 patients with dystonia. According to the classification, 54% were focal;
17.8% were segmental; 8.1% hemidistonia; 18.6% generalized and 1.5% were
multifocal. There was a positive familial history in 5.9% of the cases. The
treatment of the idiopathic dystonias is divided in: specific and symptomatic,
and it can be local with botulinum toxin, or systemic with oral drugs. The most
common drugs used in the treatment were anticholinergics and benzodiazepines,
with poor responses in the generalized forms. Botulinum toxin A was the first
line treatment for focal and segmental forms of dystonia. Meanwhile, the
generalized forms of dystonia show poor response to the therapies utilized.
PMID- 10667286
TI - [Image guided stereotactic approach of central nervous system lesions: accuracy,
morbidity, mortality].
AB - We studied seventy-five patients with brain lesions biopsied by stereotaxis from
March 1993 to December 1998 at Universidade Federal de Sao Paulo-Escola Paulista
de Medicina. The three most frequent lesions were: metastasis, low grade
astrocytomas and glioblastoma multiforme. The morbidity rate was 2.66% due to:
one case of scalp infection in a patient with thalamic cyst; and a partial
seizure during surgery in a patient with lymphoma. The mortality rate was 1.33%
due to increasing of cerebral edema after biopsy and the patient died after one
week. The diagnostic accuracy was 89.33%.
PMID- 10667287
TI - [An en bloc cranio-orbitozygomatic approach: surgical technique and results].
AB - An en bloc cranio-orbitozygomatic approach is described. This technique was
applied in seven patients (five basilar artery aneurysms, a trigeminal neuroma, a
meningioma of the lesser sphenoid wing). The follow-up period ranged from 3 to 50
months. The patients were retrospectively analyzed from the cosmetic point of
view, and submitted to computerized tomography with three dimensional and
multiplanar reconstructions. The access provided a wider operative field with a
shorter distance to the pathology and possibility of increased angulation of the
microscope. The aneurysms could be clipped and the tumors completely removed in
all cases. A frontalis muscle paralysis occurred in two cases, as well as a
temporalis muscle atrophy in another two patients. There were no enophthalmos or
bone flap displacements. The surgical technique is simple and do not require
drills, electric saws and mini-plates.
PMID- 10667288
TI - [Stereotactic implantation of depth electrodes by magnetic resonance image in
epilepsy surgery].
AB - We present the case of a 40-year-old woman with refractory epilepsy since aged
18, who was submitted to video-EEG monitoring with intracerebral depth
electrodes. The clinical history and examination, magnetic resonance image (MRI),
video-EEG and neuropsychological study did not allow the determination of the
cerebral onset of epileptic seizures. Depth electrodes inserted by MRI-guided
stereotaxis allowed the recording of the epileptic activity and thus showed quite
accurately the area of the brain to be surgically resected. She underwent a right
anterior temporal lobectomy with amygdalohippocampectomy. The immediate
postoperative period was uneventful and she is without epileptic seizures after
three months of follow-up. The average pre-operative free-seizure period was two
weeks. To our knowledge, this is the first stereotactic surgery for insertion of
depth intracerebral electrodes in epilepsy in Brazil.
PMID- 10667289
TI - Secondary bilateral synchrony due to fronto-mesial lesions. An invasive recording
study.
AB - Frontal lobe epilepsies may present difficulties in focus localization in the pre
operative work-up for epilepsy surgery. This is specially true in patients with
normal MRIs. We report on a 16 years-old girl that started with seizures by the
age of 8 years. They were brief nocturnal episodes with automatisms such as
bicycling and boxing. Seizure frequency ranged from 4-10 per night. Scalp EEG
showed few right frontal convexity spiking and intense secondary bilateral
synchrony (SBS). High resolution MRI directed to the frontal lobes was normal.
Ictal SPECT suggested a right fronto-lateral focus. Ictal video-EEG showed no
focal onset. She was submitted to invasive recordings after subdural plates
implantation. Electrodes covered all the frontal convexity and mesial surface
bilaterally. Ictal recordings disclosed stereotyped seizures starting from the
right mesial frontal. Using a high-resolution tool to measure intra and
interhemispheric latencies, the timing and direction of seizure spread from the
right fronto-mesial region were studied. Motor strip mapping was performed by
means of electrical stimulation. She was submitted to a right frontal lobe
resection, 1.5 cm ahead of the motor strip and has been seizure free since
surgery (8 months). Pathological examination found a 4 mm area of cortical
dysplasia. Invasive studies are needed to allow adequate localization in patients
with non-localizatory non-invasive work-up and may lead to excellent results in
relation to seizures after surgery.
PMID- 10667290
TI - [Septic thrombosis of cavernous sinus: report of 6 cases].
AB - The cavernous sinus is most frequently involved by septic thrombosis. The common
sites of primary infection are the medial face, orbits, tonsils, soft palate,
sphenoid and ethmoid sinuses. The usual clinical presentation begins with fever
and periorbital edema followed by headache, ptosis and ocular muscles palsy. The
diagnosis is usually made on clinical grounds. Treatment consists of eradication
of the primary source of infection and the administration of antibiotics and
anticoagulants. We report six cases of septic thrombosis of cavernous sinus.
PMID- 10667291
TI - [Prognosis factors in cryptococcal meningoencephalitis].
AB - OBJECTIVE: To identify demographic, clinical and cerebrospinal fluid (CSF)
variables associated to intrahospitalar lethality of patients with cryptococcal
meningoencephalitis. STUDY DESIGN: Retrospective cohort to study prognosis.
SETTING: Hospital Couto Maia (HCMaia) reference for patients with infectious
diseases in the State of Bahia Northeastern Brazil. POPULATION: Patients admitted
at HCMaia, from 1972 to 1996, with the diagnosis of cryptococcal
meningoencephalitis. RESULTS: Lethality rate was 42.7%. The most important
neurological abnormalities were neck stiffness, decreased consciousness level,
behavior changes, cranial nerve palsy and visual alteration. Disease time over 30
days, involvement of consciousness level and cerebrospinal fluid cells under
40/mm3 were associated to a higher lethality rate. CONCLUSION: Disease time over
30 days, involvement of consciousness level, and CSF decreased cellularity were
the only predictors of lethality in the studied population.
PMID- 10667292
TI - [Clinical manifestations in patients with computerized tomography diagnosis of
neurocysticercosis].
AB - A survey was conducted in the urban area of Lages using patients who had been
submitted to a computed tomography of the skull in the period of March-December,
1996, for different reasons. Forty-two patients with a provisional diagnosis of
neurocysticercosis, and 57 negatives were personally interviewed by one of the
authors (Pfuetzenreiter), using a semi-structured procedure. More individuals
with a provisional diagnostic of neurocysticercosis reported clinical
manifestations related to this infection than those found negative. This
difference is more marked among women, except in relation to convulsions, more
frequently reported by men (19.05%) than by women (7.14%). The greater percentage
of inactive forms (83.33%) and a longer history of perceived symptoms among those
positives suggest that the condition is not new.
PMID- 10667293
TI - [True neurogenic outlet syndrome: report of 2 cases].
AB - True neurogenic thoracic outlet syndrome is caused by compression of the lower
trunk of the brachial plexus usually by a cervical rib, fibrous band or an
elongated transverse process of C7. We describe two cases of female patients (23
and 19 years old) with pain in the right superior limb and progressive muscular
weakness and atrophy of the intrinsic muscles of hand. Electrodiagnostic studies
showed reduced amplitude of compound muscle action potential of median nerve and
decreased amplitude of ulnar sensory nerve action potential. Motor and sensory
nerve conduction velocities were normal in both patients. Needle electromyography
were findings compatible with chronic denervation in the intrinsic muscles of the
right hand of both patients. Radiological investigation showed cervical ribs in
one case and elongated transverse process of C7 in the other. A discussion about
the clinical and electrophysiological features and the treatment of the syndrome
was performed.
PMID- 10667294
TI - [Type I Chiari malformation: report of 2 cases with unusual clinical
presentation].
AB - We describe two patients with Chiari type I malformation with unusual clinical
presentation. The first one with clinical picture of acute respiratory
insufficiency and the second one with vestibular and mild cerebellar syndrome and
headache. In both cases the neurological examination demonstrated the presence of
"down-beating nystagmus". We emphasize the value of neurological semiology,
determining a correct complementary evaluation and effective treatment.
PMID- 10667295
TI - Walker-Warburg syndrome. Report of two cases.
AB - The purpose of this study is to describe two infants that were diagnosed with
Walker-Warburg syndrome (WWS), a rare form of congenital muscular dystrophy
(CMD). They were studied in their clinical, laboratory, and neuroradiologic
features. The index case had a brain magnetic resonance imaging (MRI) and the
second patient had a head computerized tomography (CT). In addition, a literature
review was performed to describe the main forms of CMD. The index case fulfilled
all criteria for WWS. A brain MRI performed at age 4 months served to corroborate
the clinical diagnosis, showing severe hydrocephalus, type II lissencephaly,
cerebellar vermian aplasia, and a hypoplastic brain stem. The authors were able
to establish a retrospective diagnosis of WWS in the index case's older sister,
based upon her clinical picture and head CT report.
PMID- 10667296
TI - Pseudocystic form of neurocryptococcosis in pregnancy. Case report.
AB - We report a case of neurocryptococcosis which is unique in the literature because
the patient had a pseudocystic form of the disease during pregnancy and without
any evidence of AIDS. The clinical picture was that of intracranial hypertension
and the epidemiological background was highly suggestive of cysticercosis. CT
showed multiple round hypodense lesions in the basal ganglia and cerebellum,
without contrast enhancement. Since a scolex was not visible, the diagnosis of
neurocysticercosis was considered probable. CSF examination was not performed in
view of its high risk. The patient had progressive downhill course. Autopsy
disclosed multiple gelatinous pseudocysts in the cerebral and cerebellar gray
matter, containing abundant Cryptococcus neoformans. Meningeal involvement was
minimal. The child was delivered by caesarean section and was free of infection,
but died later of hyaline membrane disease. The neuroimaging appearances of this
rare instance of the pseudocystic form of neurocryptococcosis mimicked closely
neurocysticercosis and only postmortem examination allowed correct diagnosis. The
pseudocystic form has so far only been reported in AIDS.
PMID- 10667297
TI - Treatment of cervical dystonia with botulinum toxin in a patient with myasthenia
gravis.
AB - We report the case of a 49-year-old woman who has the rare combination of
myasthenia gravis and cervical dystonia. She was treated with botulinum toxin
type A with good response and no evidence of deterioration of the myasthenic
symptoms. We therefore conclude that it is possible to use botulinum toxin in the
presence of defective neuromuscular transmission.
PMID- 10667298
TI - [Identical twins discordant for Cushing's disease: case report[].
AB - Cushing's disease is rare in children and its occurrence in identical twins is
extremely rare. This paper reports on identical twins discordant for Cushing's
disease. One of them first presented with a cushingoid phenotype by the age of
10. Her evaluation showed an increased urinary free-cortisol and serum ACTH. Her
pattern in the dexametazone suppression tests was compatible with Cushing's
disease. MRI disclosed a pituitary macroadenoma which was removed by the
transesphenoidal approach. Immunohistochemical studies of the tumor showed the
presence of ACTH-producing cells. The patient went into clinical and laboratorial
remission after surgery. She re-started to grow after the disappearance of the
Cushing's phenotype but she is still shorter than her healthy sister. The latter
remains disease-free 4 years after her sister's diagnosis. This represents the
third such case reported in the literature. Our findings suggest that acquired
factors may be responsible for the genesis of Cushing's disease.
PMID- 10667299
TI - [Actinomycosis of the brain: case report].
AB - Actinomycosis located in the central nervous system is an extremely uncommon
event, but if correctly diagnosed and properly treated may have a good prognosis.
This case report of a cerebral abscess caused by actinomyces suggests that such a
rare event should be included in the differential diagnosis of infectious
diseases that affect the central nervous system.
PMID- 10667300
TI - [Emotionally-loaded narrative increases dyslogia in schizophrenics].
AB - We tested the degree of dyslogia in the narrative of ten schizophrenic non
medicated outpatients while they narrated emotionally-loaded or neutral facts.
The "emotional narratives" were much more dyslogic than the "neutral narratives".
In order to explain these facts we evoke: 1. A fronto-temporo-limbic connection
dysfunction would disturb an adequate cognitive treatment of emotions that would
be, in this way, highly disruptive over logical processes. 2. A working
memory/supervisory attentional system dysfunction that would produce both a loss
of the normal connections among the fragments of speech and a lack of global
strategical planning of the thought.
PMID- 10667301
TI - Sex playing with the mind. Effects of oestrogen and testosterone on mood and
cognition.
AB - Women now spend more than 1/3 of their lives in a state of oestrogen deprivation
as a result of increased life expectancy. A similar, but milder, hypogonadal
state has been described for elderly men. This paper aims to review the available
literature on the effects of both oestrogen and testosterone on mood and
cognition. Oestrogen replacement therapy of postmenopausal women is associated
with improvements in measures of well being and decline in depression scores. In
addition, oestrogen seems to augment the response of postmenopausal women with
major depression to antidepressant treatment. Most studies designed to
investigate the impact of oestrogen on cognition indicate that replacement
therapy is associated with better performance on neuropsychological tests,
particularly in measures of verbal memory and fluency. The data also supports
claims that oestrogen replacement therapy reduces the risk of Alzheimer's disease
in later life and improves response of patients to anticholinesterase treatment.
Data on the effects of testosterone is sparser. Preliminary findings suggest that
testosterone therapy may improve mood when used in isolation or in association
with oestrogen. The effects of testosterone on cognitive functioning are less
clear--some studies indicate that the administration of testosterone to non
demented subjects is associated with better visuospatial functioning and
deterioration of verbal skills. In summary, gonadal hormones seem to modulate
various aspects of mental functioning. If future studies prove this to be true,
hormone replacement therapy should have a major impact on the physical and mental
health of older people in the years to come.
PMID- 10667302
TI - Function and regulation of prostaglandin synthase 2.
PMID- 10667303
TI - Regulation of cyclooxygenase-2 by the activated p38 MAPK signaling pathway.
PMID- 10667304
TI - Fatty acid cyclooxygenase induction and prostaglandin D synthesis in a human
megakaryoblastic cell line CMK differentiated by phorbol ester.
PMID- 10667305
TI - Eicosanoid metabolism in human platelets is modified by albumin.
PMID- 10667306
TI - Diverse functional coupling of prostanoid biosynthetic enzymes in various cell
types.
AB - As also detailed in our accompanying papers in this issue, recent studies have
revealed functional crosstalk and segregation between PLA2s, COXs, and terminal
PG synthases in various cells (Table I). Among the PLA2s, cPLA2 is required for
all three responses, and sPLA2-IIA augments the delayed response in preference to
the immediate response. sPLA2-IIA associates with proteoglycans on the surface of
stimulus-primed cells to exert its functions. COX-1 is utilized only in the
immediate response and COX-2 is a prerequisite for the delayed response. The
induced immediate response is often mediated by COX-2 rather than by COX-1,
especially when the end product is PGE2. In addition to segregated utilization of
these enzymes, significant crosstalk and/or synergism between them, which is
often cell type specific, is also obvious. For instance, sPLA2 acts as an
enhancer of COX-2 expression in rat mast cells, functional cPLA2 is required for
sPLA2 induction in rat fibroblasts, and sPLA2 augments cPLA2 and COX-2 expression
in mouse osteoblasts via endogenous PGE1. Moreover, differential coupling between
COXs and downstream terminal PG synthases is also evident in macrophages, in
which COX-1 and COX-2 are preferentially coupled with TXS and PGES, respectively.
Thus, different PG-biosynthetic enzymes, acting on different cellular AA pools at
different locations and being regulated by separate but interacting mechanisms,
confer on the system great versatility in ensuring that both immediate and
delayed AA-derived mediators are efficiently generated during cellular responses.
PMID- 10667307
TI - Regulation of prostaglandin, leukotriene, and platelet-activating factor
metabolism in mast cells.
PMID- 10667308
TI - Lipid peroxides and neuronal plasticity.
PMID- 10667309
TI - Secretion of lipocalin-type prostaglandin D synthase (beta-trace) from human
heart to plasma during coronary circulation.
PMID- 10667310
TI - Lipocalin-type prostaglandin D synthase (beta-trace) binds non-substrate
lipophilic ligands.
PMID- 10667311
TI - Features of mammalian lipoxygenases.
PMID- 10667312
TI - Identification and characterization of an enhancer sequence in the promoter
region of human 15-lipoxygenase (15-LO) gene.
PMID- 10667313
TI - Cytokine induced regulation of 15-lipoxygenase and phospholipid hydroperoxide
glutathione peroxidase in mammalian cells.
PMID- 10667314
TI - Investigation of a second 15S-lipoxygenase in humans and its expression in
epithelial tissues.
PMID- 10667315
TI - Sequence determinants for the positional specificity of mammalian and plant
lipoxygenases.
PMID- 10667316
TI - X-ray absorption studies into the iron ligand sphere of plant and animal
lipoxygenases.
PMID- 10667317
TI - Transcriptional and posttranscriptional regulation of 5-lipoxygenase mRNA
expression in the human monocytic cell line Mono Mac 6 by transforming growth
factor-beta and 1,25-dihydroxyvitamin D3.
PMID- 10667318
TI - Comparison of prostaglandin H synthase-1 and -2 structural stabilities.
PMID- 10667319
TI - Modulation of the expression of the cyclooxygenase 1 and 2 genes in rat mammary
glands: role of hormonal status and dietary fat.
PMID- 10667320
TI - Regulation of cerebrovascular cyclooxygenase-2 by pro- and anti-inflammatory
cytokines.
PMID- 10667321
TI - Visualization and quantitation of cyclooxygenase-1 and -2 activity by digital
fluorescence microscopy.
PMID- 10667322
TI - Discovery of a new class of selective cyclooxygenase-2 (COX-2) inhibitor that
covalently modifies the isozyme.
PMID- 10667323
TI - Mitigation of arthritis by high-dose administration of a COX-2 inhibitor in the
collagen-induced arthritis model in the mouse.
PMID- 10667324
TI - Indomethacin inhibition of pristane plasmacytomagenesis in genetically
susceptible inbred mice.
PMID- 10667325
TI - Role of COX-2 inhibition on the formation and healing of gastric ulcers induced
by indomethacin in the rat.
PMID- 10667326
TI - Regulation of in vivo prostaglandin biosynthesis by glutathione.
PMID- 10667327
TI - Different effects of reactive nitrogen intermediates on prostaglandin E2
synthesis in cultured rat microglia and RAW 264.7 cells.
PMID- 10667328
TI - Activation of cPLA2 in vascular smooth muscle.
PMID- 10667329
TI - Role of type IIA secretory phospholipase A2 in arachidonic acid metabolism.
AB - Recent recognition of the rapidly growing sPLA2 family has led to a suggestion
that some of the previously described functions of sPLA2-IIA need to be
reevaluated, since studies based upon enzyme activities and using inhibitors or
antibodies against sPLA2-IIA may not discriminate these sPLA2s. Our present
studies reconfirm the involvement of sPLA2-IIA in biological responses,
demonstrated significant crosstalk between the two Ca(2+)-dependent PLA2s (cPLA2
and sPLA2) where one enzyme is required for the induction of the other, and
revealed segregated coupling of discrete PLA2 and COX enzymes in the different
phases of PG biosynthesis. Based upon the analysis of cells derived from sPLA2
IIA "natural knock-out" mice, it is apparent that sPLA2-IIA is not essential for
the initiation of delayed PGE2 biosynthesis. However, it is capable of
contributing to the delayed response as an enhancer when appropriately induced by
proinflammatory stimuli, leading to optimal COX-2-dependent PGE2 generation.
Importantly, in order for sPLA2-IIA (or related sPLA2 isozymes) to attack the
biological membranes, so-called "membrane rearrangement" should take place in
activated, but not resting, cells. Membrane rearrangement also occurs when cells
are undergoing apoptosis, during which acidic phospholipids, the preferred
substrates for sPLA2-IIA, are exposed on the outer leaflet of the plasma
membranes. Nonetheless, in view of the dramatically elevated levels of sPLA2-IIA
in inflamed or ischemic sites, it is likely that this extracellular isozyme
participates in the expansion of chronic tissue disorders by augmenting
generation of proinflammatory eicosanoids or lysophospholipids, depending upon
the states of the inflammatory response.
PMID- 10667330
TI - Phospholipase A2 is involved in chemotaxis of human leukocytes.
PMID- 10667331
TI - Suppression of acute experimental inflammation by antisense oligonucleotides
targeting secretory phospholipase A2 (sPLA2) in vitro and in vivo experiments.
AB - In HepG2 cells phosphorothioate modified antisense oligonucleotides against a
sequence in the Ca2+ binding domain (AS-Ca2+) of type II sPLA2 mRNA restrained IL
6-induced synthesis of sPLA2 protein, sPLA2 mRNA (northern blot), and abolished
IL-6 stimulated PGE2 release. An antisense oligonucleotide corresponding to a
sequence in the catalytic domain (AS-Cat) of sPLA2 was less effective. The
antisense oligonucleotides did not affect albumin synthesis in HepG2 cells,
additionally demonstrating their specificity. The corresponding AS-Ca2+ against a
homologous part of the rat sPLA2 mRNA depressed rat carrageenin oedema for 60
70%. Identical suppression was achieved by specific low molecular weight
inhibitors of sPLA2. Since cyclo- and 5-lipoxygenase inhibitors exerted similar
reductions of carrageenin oedema type II sPLA2 dependent eicosanoid formation
seems to be a key cascade in this type of inflammation.
PMID- 10667332
TI - Comparison of recombinant types IIA, V and IIC phospholipase A2S, the three
related mammalian secretory phospholipase A2 isozymes.
PMID- 10667333
TI - Respective roles of the 14 kDa and 85 kDa phospholipase A2 enzymes in human
monocyte eicosanoid formation.
AB - Human monocytes possess both the cytosolic 85 kDa phospholipase (PLA) A2 and a 14
kDa PLA2 and are capable of simultaneously producing prostanoids (PG),
leukotrienes (LT) and platelet activating factor (PAF). As the exact roles of the
two enzymes in monocyte lipid mediator formation was unclear, both selective PLA2
inhibitors and antisense were used to elucidate their respective roles. Reduction
in 85 kDa PLA2 cellular protein levels by initiation site-directed antisense (SK
7111) or exposure to the 85 kDa PLA2 inhibitor, arachidonyl trifluormethyl ketone
(AACOCF3), prevented A23187 or zymosan-stimulated monocytes prostanoid formation
but not LTC4 or PAF production. This confirmed the important role of the 85 kDa
PLA2 in prostanoid formation but indicated a less significant role in LT or PAF
biosynthesis. Alternatively, treatment of monocytes with the selective, active
site-directed 14 kDa PLA2 inhibitor, SB 203347, totally inhibited LT and PAF
formation, while prostanoid formation was not altered. Addition of 20 uM
exogenous arachidonic acid (AA) to monocytes exposed to SB 203347 did not alter
A23187-induced LTC4 generation, indicating that SB 203347 had no effect on
downstream AA metabolizing enzymes in this setting. Taken together, these results
provide evidence that the 14 kDa PLA2 provides substrate for monocyte LT and PAF
formation, while the 85 kDa PLA2 plays a more significant role in the formation
of PG.
PMID- 10667334
TI - Modulation of long-term potentiation in the CA1 area of rat hippocampus by
platelet-activating factor.
PMID- 10667335
TI - PPARs: nuclear receptors for fatty acids, eicosanoids, and xenobiotics.
AB - The peroxisome proliferator-activated receptors have enjoyed the spotlight for
many reasons. These transcription factors are ligand-inducible nuclear receptors
that modulate gene expression in response to a broad spectrum of compounds. The
recognition that PPARs are indeed nuclear receptors for polyunsaturated fatty
acids, some eicosanoids and also lipid-lowering and antidiabetic drugs, has
opened many exciting avenues of research and drug discovery. Recent studies on
the PPAR function have extended the role of these transcription factors beyond
energy homeostasis to master gene in adipogenesis and also determinants in
inflammation control. While rapid advances have been made, it is clear that we
are far from a global understanding of the mechanisms and functions of PPARs.
PMID- 10667336
TI - Molecular cloning and characterization of leukotriene B4 receptor.
PMID- 10667337
TI - Determinants of receptor subtype specificity in the LPA-like lipid mediator
family.
PMID- 10667338
TI - Subunits and cellular occurrence of the 12(S)-HETE binding complex.
PMID- 10667339
TI - A subfamily of G protein-coupled cellular receptors for lysophospholipids and
lysosphingolipids.
AB - The results of molecular cloning and homology searches have identified a minimum
of five different proteins of the endothelial differentiation gene (edg) encoded
subfamily of GPCRs. Edg protein GPCRs show amino acid sequence identity of 31% to
34% as a subfamily, but contain two homology clusters with greater similarity of
structures and functions. One cluster of high amino acid sequence homology
includes Edg-2 and Edg-4 proteins, that encode GPCRs for LPA, but not
lysosphingolipids. A second homology cluster encompasses Edg-1, Edg-3 and Edg-5.
Edg-3 and Edg-5 encode GPCRs specific for S1P, but not LPA. Preliminary data
suggest that Edg-1 encodes a GPCR for S1P and one or more other
lysosphingolipids, but the signals evoked by S1P alone are far weaker than those
transduced by Edg-3 and Edg-5. Similarities of the structures of genes for the
respective homology clusters supports this tentative classification of the Edg
protein GPCRs. Future research will be directed to completion of the elucidation
of genomic organization and signaling pathways, and a greater understanding of
the breadth of functional roles of Edg proteins in development and activities of
the nervous, cardiovascular, endocrine and immune systems.
PMID- 10667340
TI - Evidence for involvement of prostaglandin I2 as a major nociceptive mediator in
acetic acid-induced writhing reaction: a study using IP-receptor disrupted mice.
PMID- 10667341
TI - Local anesthetic effects on TXA2 receptor mediated platelet aggregation using
quenched flow aggregometry.
PMID- 10667342
TI - Volatile and local anesthetics interfere with thromboxane A2 receptors
recombinantly expressed in Xenopus oocytes.
PMID- 10667343
TI - Aspirin-triggered 15-epi-lipoxin A4 and novel lipoxin B4 stable analogs inhibit
neutrophil-mediated changes in vascular permeability.
PMID- 10667344
TI - Cleavage of leukotriene D4 in mice with targeted disruption of a membrane-bound
dipeptidase gene.
PMID- 10667345
TI - Gamma-glutamyl leukotrienase cleavage of leukotriene C4.
PMID- 10667346
TI - LTE4 blood levels in infants with congenital heart lesions.
PMID- 10667347
TI - Evaluation of the pharmacological activity of the pure cysteinyl-leukotriene
receptor antagonists CGP 45715A (iralukast) and CGP 57698 in human airways.
PMID- 10667348
TI - Evidence for a carbocation intermediate in the enzymatic transformation of
leukotriene A4 into leukotriene B4.
PMID- 10667349
TI - A random rapid equilibrium mechanism for leukotriene C4 synthase.
AB - Kinetic studies performed on the conjugation reaction catalyzed by LTC4 synthase
proved to conform to a random rapid equilibrium mechanism which was further
substantiated by competition patterns ruling out other possible mechanisms. Most
cytosolic Gst's investigated to date appear to follow a random kinetic mechanism
although are mainly responsible for detoxification purposes. Conversely, LTC4
synthase possesses a very different biological role yet still follows a similar
mechanism. Therefore, it can be concluded that most GSTs function in a consistent
manner regardless of their biological function. Of interest are the mechanisms of
the other members of the MAPEG family which in some respects are closer to
conventional GSTs than to LTC4 synthase, yet they remain to be deciphered.
PMID- 10667350
TI - Formation of reactive products of the isoprostane pathway: isolevuglandins and
cyclopentenone isoprostanes.
PMID- 10667351
TI - Formation of novel isoprostane-like compounds from docosahexaenoic acid.
PMID- 10667352
TI - cDNA cloning, expression and chromosomal localization of two human
lysophosphatidic acid acyltransferases.
AB - In this report we describe a pair of human LPAAT isozymes. These isozymes are
encoded by distinct genes located on different chromosomes, but share sequence
homology, substrate specificity, and intracellular location. The biological value
of maintaining the two closely related LPAAT genes in the human genome is not
clear. We find that both isozymes are widely expressed, although expression
levels do diverge significantly in tissues such as the liver, placenta, testes,
and pancreas. We also find that, at least in the artificial system of over
expression in COS7 cells, both isozymes localize to the ER membrane. Thus,
distinct tissue-specific or subcellular compartment-specific roles for the two
isozymes are not supported by the current experimental evidence. It does remain
possible that induction of expression or subcellular translocation of one or the
other isozyme may distinguish their functions. A survey of a limited number of
acyl CoA substrates indicates that the two isozymes display similar substrate
specificities, although slight differences are suggested by the data. However,
extensive analysis of both isozymes with multiple substrates in the same assay
system will be required to detect physiologically relevant differences in
substrate specificity. LPA and PA are central intermediates in phospholipid
biogenesis. Furthermore, they have the capacity to mediate signaling both between
and within cells. The importance of these mediators is reflected in the growing
body of literature dedicated to unraveling the mechanistic basis for their
actions. Until recently, the field has been hampered by a dearth of reagents
appropriate for the molecular dissection of the LPA and PA metabolic and
signaling pathways in eukaryotes. However, the recent cloning of possible LPA
receptors will promote further understanding of LPA signaling. Similarly, the
recent appearance of LPAAT homologs in the EST database has prompted a flurry of
reports describing their characterization. These clones will afford opportunity
for defining the function of LPAAT in eukaryotic phospholipid metabolism.
PMID- 10667353
TI - The first cloned and identified lysophospholipid (LP) receptor gene, vzg-1:
implications for related receptors and the nervous system.
PMID- 10667354
TI - Involvement of protein kinase C, p38 MAP kinase and ERK in arachidonic acid
stimulated superoxide production in human neutrophils.
PMID- 10667355
TI - 13(S)-HpODE augments epidermal growth factor signal transduction by attenuating
EGF receptor dephosphorylation.
PMID- 10667356
TI - Role of lipoxygenase in the regulation of glucose transport in aortic vascular
cells.
PMID- 10667357
TI - Functions of the p21-activated protein kinases (Paks) in neutrophils and their
regulation by complex lipids.
PMID- 10667358
TI - Inhibition of neurofibromin and p120 GTPase activating protein (GAP) by dietary
fatty acids.
AB - Neurofibromin and p120 GTPase activating protein (p120 GAP) down-regulate the
activity of cellular Ras proteins. How the activity of these two proteins is
controlled is not yet clear. In this study, we analyzed the effects of eight
nutritionally relevant fatty acids on GTPase stimulatory activity of full-length
neurofibromin and p120 GAP. The fatty acids tested were: saturated stearic acid,
monounsaturated oleic acid, three omega-6 and three omega-3 polyunsaturated fatty
acids. The analysis was performed by Ras immunoprecipitation GTPase assay. The
full-length p120 GAP expressed in insect Sf9 cells and the immunoaffinity
purified full-length neurofibromin were used. Neurofibromin was readily inhibited
by stearic and oleic acid, but p120 GAP was not inhibited even at high
concentrations (> 80 microM). Neurofibromin was also inhibited by low
concentrations of all the polyunsaturated fatty acids tested (IC50 of 6 to 16
microM). p120 GAP was 2-3 fold less sensitive to inhibition by these fatty acids.
The GTPase stimulatory activity of neurofibromin was also inhibited by
arachidonic and oleic acid in the presence of a lipid mixture representing the
major lipid components of the cell membrane. Chimeric proteins of neurofibromin
and p120 GAP were used to determine that differential sensitivity to fatty acid
inhibition maps to the catalytic domain of the proteins. These results indicated
that fatty acids can modulate the GTPase function of the c-Ha-Ras protein by
inhibiting the GTPase stimulatory activity of two Ras regulators, full-length
neurofibromin and p120 GAP, at physiologically relevant concentrations in vitro.
PMID- 10667359
TI - Spinal synthesis and release of prostanoids after peripheral injury and
inflammation.
PMID- 10667360
TI - Prostaglandin E2 as a modulator of lymphocyte mediated inflammatory and humoral
responses.
PMID- 10667361
TI - Lipid mediators stimulate reactive oxygen species formation in immortalized human
keratinocytes.
PMID- 10667362
TI - Nitric oxide synthesis is increased in periodontitis.
PMID- 10667363
TI - Augmentation effects of high glucose on endotoxin-induced nitric oxide production
in murine macrophages.
PMID- 10667364
TI - 1,2-Diacylglycerol hydroperoxide induces the generation and release of superoxide
anion from human polymorphonuclear leukocytes.
PMID- 10667365
TI - Kinetic evaluation of endogenous leukotriene B4 and E4 acute activation of
inflammatory cells in the rabbit.
PMID- 10667366
TI - Lipopolysaccharide- and liposome-encapsulated MTP-PE-induced formation of
eicosanoids, nitric oxide and tumor necrosis factor-alpha in macrophages.
PMID- 10667367
TI - LTA4 hydrolase expression during glomerular inflammation: correlation of
immunohistochemical localization with cytokine regulation.
PMID- 10667368
TI - 12-Lipoxygenase products increase monocyte:endothelial interactions.
AB - In summary, we suggest that hyperglycemia causes upregulation of 12-lipoxygenase
activity. The increased production of 12-LO products, 12(S) and 15(S)-HETE,
activates monocyte integrins which result in enhanced adhesion of monocytes to
endothelium. The binding of monocytes to endothelium is a key early event in
development of atherosclerosis. Upregulation of this process by vascular cells
exposed to chronic elevations in glucose may be one explanation for the
accelerated atherosclerosis observed in patients with Type 2 diabetes.
PMID- 10667369
TI - Linoleic acid metabolites in health and disease.
PMID- 10667370
TI - Toxicity of linoleic acid metabolites.
PMID- 10667371
TI - Dramatic increase of linoleic acid peroxidation products by aging,
atherosclerosis, and rheumatoid arthritis.
PMID- 10667372
TI - Modulation of atherogenesis by dietary gamma-linolenic acid.
AB - Data from our in vitro studies indicate that macrophages isolated from mice fed
GLA-enriched diets inhibit vascular SMC proliferation via a PGE1-cAMP dependent
mechanism. Since SMC proliferation is one of the main events implicated in the
pathogenesis of atherosclerosis (Ross, 1993), this anti-proliferative effect
observed by dietary GLA is noteworthy. In vivo studies have established that
dietary GLA is capable of retarding the atherosclerotic lesion formation in ApoE
knock out mice, an animal model that develops atherosclerosis similar to humans
(Reddick, 1994). We propose that dietary GLA has the potential to inhibit SMC
proliferation leading to retardation of atherosclerotic lesion formation, and
therefore favorable modulation of the atherogenic process.
PMID- 10667373
TI - The selective cytotoxicity of gamma-linolenic acid (GLA) is associated with
increased oxidative stress.
PMID- 10667374
TI - gamma-linolenic acid (GLA)-mediated cytotoxicity in human prostate cancer cells.
PMID- 10667375
TI - Five-lipoxygenase inhibitors reduce Panc-1 survival: synergism of MK886 with
gamma linolenic acid.
PMID- 10667376
TI - Enzymological and molecular biological studies on anandamide amidohydrolase.
AB - Previously we suggested that anandamide amidohydrolase partially purified from
porcine brain catalyzed the anandamide synthesis. The reversibility of the
anandamide hydrolytic reaction was confirmed with a recombinant enzyme of rat
liver. We also showed that the recombinant enzyme had a wide substrate
specificity hydrolyzing primary amides and esters of fatty acids in addition to
anandamide. When the organ distribution of anandamide amidohydrolase was examined
with rats, a large amount of the enzyme was contained in small intestine as well
as liver and brain. The intestinal hydrolase was masked by endogenous lipid
inhibitors. The enzyme was also found in various eye tissues.
PMID- 10667377
TI - A pathway for the biosynthesis of fatty acid amides.
PMID- 10667378
TI - Investigation of structural analogs of prostaglandin amides for binding to and
activation of CB1 and CB2 cannabinoid receptors in rat brain and human tonsils.
PMID- 10667379
TI - Hepoxilin A3 is metabolized into its omega-hydroxy metabolite by human
neutrophils.
PMID- 10667380
TI - Oxidation of arachidonate containing glycerophospholipids in intact red blood
cells and red blood cell membranes with tert-butylhydroperoxide.
PMID- 10667381
TI - Cannabinoid modulation of neuronal activity in adult rat hippocampus.
PMID- 10667382
TI - Cyclooxygenase-independent induction of p21WAF-1/CIP1, apoptosis and
differentiation by L-745,337 and salicylate in HT-29 colon cancer cells.
PMID- 10667383
TI - Modulation of cellular proliferation and induction of apoptosis in a human
lymphoma cell line after treatment with selective lipoxygenase inhibitors.
PMID- 10667384
TI - Mechanisms of peroxynitrite-induced apoptosis in HL-60 cells.
PMID- 10667385
TI - Central role of arachidonate 5-lipoxygenase in the regulation of cell growth and
apoptosis in human prostate cancer cells.
PMID- 10667387
TI - The possible involvement of 15-lipoxygenase/leukocyte type 12-lipoxygenase in
colorectal carcinogenesis.
PMID- 10667386
TI - Role of autocrine motility factor in a 12-lipoxygenase dependent anti-apoptotic
pathway.
PMID- 10667388
TI - Induction of leukotriene B4 metabolism by cancer chemopreventive agents.
PMID- 10667389
TI - Intestinal tumor load in the Min/+ mouse model is not correlated with eicosanoid
biosynthesis.
PMID- 10667390
TI - 12-lipoxygenase expression in human melanoma cell lines.
AB - 12-lipoxygenase (12-LOX) expression and function in the regulation of the
metastatic phenotype was demonstrated in several murine melanoma lines before.
Here we have provided novel evidences that, though at a low level (in max. 15% of
the cell population), human melanoma lines (HT168, M1, HT199, HT18 and WM35)
express the platelet-type isoform of 12-LOX both at mRNA and protein levels. 12
LOX expression was demonstrated in cultured tumor cells and in skin tumor
xenografts. Comparison of the expression of 12-LOX in skin primary tumors and its
lung metastases indicated a stable expression. The low level of 12-LOX expression
in human melanoma cell lines suggests that other lipoxygenase(s) could also be
responsible for the metabolism of arachidonic acid to 12-HETE breakdown products.
PMID- 10667391
TI - Platelet-type 12-lipoxygenase regulates angiogenesis in human prostate carcinoma.
PMID- 10667392
TI - Prostaglandin H synthase and lipoxygenase mediated activation of xenobiotics in
platelets.
AB - To investigate the involvement of prostaglandin H synthase (PHS) and lipoxygenase
(LPO) in the activation of xenobiotics in platelets, platelet sonicates were
preincubated with alpha-naphthol. Protein covalent binding of alpha-naphthol was
measured following addition of arachidonic acid. Protein covalent binding was
increased in a dose-dependent manner until it plateaued at 500 microM arachidonic
acid. Pretreatment by two inhibitors of PHS, aspirin and indomethacin, resulted
in a dose-dependent inhibition of alpha-naphthol-induced covalent binding,
confirming PHS involvement. In addition, pretreatment by a LPO inhibitor,
nordihydroguaiaretic acid (NDGA), also prevented covalent binding substantially,
showing that LPO may be an alternative pathway for xenobiotic activation in
platelets. Furthermore, combined treatment of aspirin and NDGA almost abolished
the increase of alpha-naphthol-induced covalent binding, suggesting that PHS and
LPO are both major pathways for xenobiotic activation in platelets.
PMID- 10667393
TI - Characterization of two spliced variants of human phosphatidic acid phosphatase
cDNAs that are differentially expressed in normal and tumor cells.
PMID- 10667394
TI - Eicosapentaenoic acid alters manganese superoxide dismutase immunoreactive
protein levels in normal but not malignant central nervous system derived cells.
PMID- 10667395
TI - Gamma radiation and release of norepinephrine in the hippocampus.
PMID- 10667396
TI - (3R)-hydroxy-oxylipins--a novel family of oxygenated polyenoic fatty acids of
fungal origin.
PMID- 10667397
TI - Eicosanoids in the brain of warm- and cold-acclimated bullfrogs.
PMID- 10667398
TI - Production of 3-hydroxy fatty acids by the yeast Dipodascopsis uninucleata.
Biological implications.
PMID- 10667399
TI - Catalytic properties of linoleate diol synthase of the fungus Gaeumannomyces
graminis: a comparison with PGH synthases.
PMID- 10667400
TI - Carboplatin.
PMID- 10667401
TI - The accuracy of intraoperative cytopathological diagnosis compared with
conventional histopathological diagnosis.
AB - To determine the accuracy of intraoperative cytopathological diagnosis compared
with conventional histopathological diagnosis, the authors obtained 100 specimens
from masses of various organ systems chosen randomly from 65 dogs, 30 cats, and
five exotic animals. Of the 100 specimens, a specific diagnosis was obtained in
42%, the correct pathological process (i.e., mesenchymal neoplasia, epithelial
neoplasia, round cell neoplasia, or inflammation) was identified in 41%, in 1%
the diagnosis was deferred, and in 16% an incorrect diagnosis was obtained. The
overall accuracy rate of intraoperative cytopathological examination was 83%,
which increased to 90% by the exclusion of splenic masses. The accuracy rate of
diagnosing neoplasia was 87%, with a sensitivity of 89% and a specificity of
100%. Intraoperative cytopathological examination is an accurate diagnostic
method with good sensitivity and specificity for the identification of neoplasia.
PMID- 10667402
TI - Hypercalcemia in a dog: a challenging case.
AB - An 18-month-old, spayed female, mixed-breed dog was referred for investigation of
persistent hypercalcemia. After extensive diagnostic evaluation, a tentative
diagnosis of occult lymphosarcoma (LSA) was made and the dog was euthanized. At
necropsy, infection with Heterobilharzia americana was diagnosed. In endemic
areas, schistosomiasis should be included in the differential diagnosis of
hypercalcemia, and a fecal examination should be performed in every dog with a
hypercalcemia of unknown origin.
PMID- 10667403
TI - Glucagon constant-rate infusion: a novel strategy for the management of
hyperinsulinemic-hypoglycemic crisis in the dog.
AB - A six-year-old, spayed female, cocker spaniel was presented for hypoglycemic
seizures. Hypoglycemia with concomitant hyperinsulinemia suggested an insulin
secreting tumor. Pancreatic masses were resected, and insulinoma was diagnosed.
Six weeks later, the dog presented in hyperinsulinemic-hypoglycemic crisis (HHC).
The dog was initially stabilized with intravenous dextrose boluses and infusions,
but seizure activity recurred and persisted. A glucagon constant-rate infusion
(GCRI) was initiated, and neurological signs quickly resolved. Dextrose was
withdrawn over 24 hours, and euglycemia was maintained by GCRI alone. Despite
aggressive medical management including the use of prednisone, diazoxide, bovine
somatotropin, and streptozocin, the dog presented on two subsequent occasions in
HHC and both times was rapidly stabilized with GCRI alone. In this dog, GCRI was
a fast, safe, and effective method of achieving and maintaining euglycemia
despite intractable hyperinsulinism. The clinical use of GCRI merits further
investigation for management of HHC in veterinary species.
PMID- 10667404
TI - Syringohydromyelia in Cavalier King Charles spaniels.
AB - Syringohydromyelia secondary to foramen magnum overcrowding is described in seven
Cavalier King Charles spaniels. Clinical signs were consistent with a central
spinal cord lesion. The most common signs were persistent scratching at the
shoulder region with apparent neck, thoracic limb, or ear pain and thoracic limb
lower motor neuron deficits. The diagnosis was made by magnetic resonance
imaging. The syringohydromyelia is postulated to be a consequence of an occipital
bone malformation resulting in a small caudal fossa and cerebellar herniation.
Clinical signs improved but did not completely resolve when the dogs received
treatment with corticosteroids or nonsteroidal anti-inflammatory drugs.
PMID- 10667405
TI - A modified bilateral transfrontal sinus approach to the canine frontal lobe and
olfactory bulb: surgical technique and five cases.
AB - Five adult dogs presented for an acute onset of seizure activity. Magnetic
resonance imaging revealed lesions in the olfactory bulbs, frontal lobes of the
cerebrum, or both. A modified bilateral transfrontal sinus craniotomy was
performed on each patient. The goal of removing the lesion was to relieve
clinical signs and to provide tissue for histopathological diagnosis. In each
instance, excision of the lesion was possible using this approach. No
postoperative complications were observed. The modified bilateral transfrontal
sinus craniotomy provides excellent access to the canine olfactory bulbs and
frontal lobes.
PMID- 10667406
TI - Probable hypercalcemia of malignancy in a cat with bronchogenic adenocarcinoma.
AB - An eight-year-old, neutered male, domestic shorthair cat was referred with a four
day history of acute vomiting. Hypercalcemia was identified on serum biochemical
testing. Thoracic radiographs showed multiple pulmonary nodular densities.
Postmortem and histopathological examination identified the nodules as
bronchogenic adenocarcinoma with metastases to the tracheobronchial lymph nodes,
diaphragm, and parietal pleura. To the authors' knowledge, this is the first
reported case of hypercalcemia of malignancy associated with bronchogenic
adenocarcinoma in a cat.
PMID- 10667407
TI - Acute bilateral trigeminal neuropathy associated with nervous system
lymphosarcoma in a dog.
AB - A nine-year-old dog presented with clinical signs consistent with bilateral
trigeminal neuropathy. Multicentric lymphoma was diagnosed, and neoplastic
lymphocytes were identified in the cerebrospinal fluid. Electromyography revealed
spontaneous activity in temporal and masseter muscles. Histopathological
examination demonstrated neoplastic cell invasion of temporal and masseter
myofibers and of multiple peripheral nerves, including the trigeminal nerve.
Central nervous system pathology consisted primarily of spinal root and
leptomeningeal lymphoid cell infiltration with relative sparing of spinal cord
and brain parenchyma.
PMID- 10667408
TI - Skeletal muscle lymphoma in a bullmastiff.
AB - A 16-month-old, neutered male bullmastiff was presented for acute onset of
massive swelling of the right hind limb. Primary skeletal muscle lymphoma was
diagnosed based on cytopathology, surgical biopsy, and necropsy findings.
Cutaneous metastases developed during the hospitalization, and additional
metastases were found in the heart and thoracic wall. Primary skeletal muscle
lymphoma is a rare form of lymphoma in dogs and should be considered as a
differential diagnosis for acute, soft-tissue swelling of the limb.
PMID- 10667409
TI - Caudal cervical intervertebral disk disease in the small dog: role of distraction
and stabilization in ventral slot decompression.
AB - The clinical outcomes in 112 dogs weighing less than 35 pounds that were
presented with cervical intervertebral disk protrusions were retrospectively
evaluated. Although the second to third cervical (C2 to C3) intervertebral space
was the most common site (27%) of disk protrusion, 57% of disk protrusions
presented were caudal to the fourth cervical (C4) vertebra. Dogs with cranial
intervertebral disk protrusions, including the C2 to C3 and C3 to C4
intervertebral disk spaces, responded favorably to ventral slot decompression. By
comparison, caudal intervertebral disk protrusions (within the C4 to the seventh
cervical [C7] intervertebral disk spaces) responded less favorably to ventral
slot decompression, demonstrating significantly more severe clinical effects in
motor function, comfort, recovery, and long-term outcome following surgery.
Significant improvement in clinical results was seen in caudal disk protrusions
when additional surgical distraction and stabilization were provided following
ventral slot decompression.
PMID- 10667410
TI - Use of a free cortical ulnar autograft following en bloc resection of a
mandibular tumor.
AB - A dog was presented for the en bloc resection of a previously irradiated
mandibular ossifying epulis. A central hemimandibulectomy was performed, and the
mandibular defect was stabilized by the use of a free cortical ulnar autograft
and rigid internal fixation. The dog had normal mastication and left forelimb
function two weeks after surgery. Radiographic evaluation of the surgical site at
three and 10 months after surgery showed normal bony healing.
PMID- 10667411
TI - Contrast radiographic findings in canine bacterial discospondylitis: a
multicenter, retrospective study of 27 cases.
AB - A multicenter, retrospective study was undertaken to evaluate contrast
radiographic findings in canine bacterial discospondylitis. Records and
myelograms or epidurograms of 27 patients were obtained from five colleges of
veterinary medicine. Fifteen cases (56%) were evaluated as having some degree of
spinal cord compression. The majority (73.3%) of the cases had only soft tissue
as the compressive mass. The median compression for all cases was 5% of the
vertebral canal. No difference was noted for compression based on anatomical site
(i.e., cervical versus thoracolumbar versus lumbosacral). No significant
correlation between degree of lesion compression and clinical outcome was noted,
but there was a trend toward increased mortality with greater compression. There
was no correlation between the ambulatory status and the ultimate outcome. Three
of the 15 (20%) cases showed vertebral subluxation. Results of this study
indicate that static spinal cord compression is not a significant component of
the neurological dysfunction associated with bacterial discospondylitis.
Identification of vertebral subluxation in some patients may indicate a dynamic
lesion that should be evaluated with stress radiography.
PMID- 10667412
TI - How should atypical prostate needle biopsies be reported? Controversies regarding
the term "ASAP".
PMID- 10667413
TI - ASAP. Atypical small acinar proliferations.
PMID- 10667414
TI - ASAP. Atypical small acinar proliferations.
PMID- 10667415
TI - ASAP is a valid diagnosis. Atypical small acinar proliferation.
PMID- 10667416
TI - The Mi15 monoclonal antibody (anti-syndecan-1) is a reliable marker for
quantifying plasma cells in paraffin-embedded bone marrow biopsy specimens.
AB - Plasmocyte selective monoclonal antibodies (MAb) recognizing syndecan-1 have
recently been described. They belong to a new cluster, CD138. Using the MAb MI15,
we investigated the expression of syndecan-1 in routinely paraffin-embedded
tissues. Nontumoral lymph nodes (25 cases) and bone marrow biopsy specimens (63
cases) showed strong membrane staining of plasma cells only, allowing accurate
analysis of the nuclear structure. The MI15 positivity correlated with kappa and
lambda light chain expression in the cytoplasm. The percentages of plasma cells
calculated in bone marrow biopsy specimens after MI15 staining were,
respectively, 2.1% (range, 1% to 4%) in normal bone marrows, 8.5% (range, 5 to
17) in reactive plasmocytosis, and 4.66% in monoclonal gammapathy of undetermined
significance (MGUS) patients (range, 1 to 13), in the same range but slightly
higher than those obtained on smears or on hematoxylin and eosin (H&E)-stained
sections. In multiple myeloma (40 cases), all plasma cell types were marked, and
Mi15 MAb gave additional information in 8 of 40 (20%) patients. In lymph nodes,
Mi15 MAb reacted with Reed-Sternberg cells of classical Hodgkin's disease in 23
of 31 cases (74%) with variable intensity. In contrast, nodular lymphocyte
predominance Hodgkin's disease (10 cases), most B cell lymphomas (88 of 107
cases) and all T cell lymphomas (30 cases) were negative. In B cell lymphomas,
plasmocytomas (8 cases), plasmocytic lymphomas (2 cases), and 5 of 13 cases of
immunoblastic lymphoma with plasmocytoid differentiation were stained. In
lymphoplasmocytoid lymphomas (4 lymph nodes and 20 bone marrow biopsy specimens),
only mature plasma cells were positive. Moreover, a wide distribution of syndecan
1 was observed in normal and tumoral epithelial tissues. Finally, Mi15 MAb
appears to be a reliable marker for identifying and quantifying normal and
tumoral plasma cells in paraffin-embedded bone marrow and lymph node samples.
PMID- 10667417
TI - Cell damage and proliferation in human gastric mucosa infected by Helicobacter
pylori--a comparison before and after H pylori eradication in non-atrophic
gastritis.
AB - Helicobacter pylori (HP) is believed to be involved in the transition from normal
gastric mucosa to atrophic gastritis and intestinal metaplasia. Infection with
the organism is one of the risk factors for development of intestinal-type
gastric adenocarcinoma, possibly through altered cell turnover. Medical
eradication of HP is widely performed for the treatment of peptic ulcers and
other upper gastrointestinal disorders. Eradication of HP may affect altered cell
turnover of the gastric mucosa caused by the infection, but there are few reports
comparing sterilized mucosa with HP-infected and non-infected mucosa. In this
study, we examined cell damage using terminal deoxynucleotidyl transferase
mediated dUTP-biotin nick-end labeling (TUNEL), in situ nick translation (ISNT),
and cell proliferation by Ki 67 immunohistochemistry staining in gastric mucosa
before and after HP eradication and in non-infected gastric mucosa. We then
compared these findings using endoscopic gastric biopsy specimens. Labeling
indices of TUNEL (2.46 +/- 1.22), ISNT (1.13 +/- 0.42), and Ki67 (21.8 +/- 6.14)
in tissue from which HP had been eradicated were significantly lower than those
of HP-infected mucosa (6.36 +/- 2.26, 4.00 +/- 1.62, 45.8 +/- 5.35, for TUNEL,
ISNT, and Ki67, respectively). There were no significant differences between
formerly infected and non-infected mucosa (TUNEL: 2.26 +/- 0.69, ISNT: 1.29 +/-
0.63, Ki67: 23.5 +/- 8.20). These results indicate that medical HP eradication
results in decreased cell proliferation and damage, restoring the condition seen
in non-infected mucosa. Thus, HP eradication may be effective, not only in the
treatment of gastric ulcers or gastric symptoms, but also in the prevention of
gastric carcinoma.
PMID- 10667418
TI - A comparative study of fibrous dysplasia and osteofibrous dysplasia with regard
to expressions of c-fos and c-jun products and bone matrix proteins: a
clinicopathologic review and immunohistochemical study of c-fos, c-jun, type I
collagen, osteonectin, osteopontin, and osteocalcin.
AB - Fibrous dysplasia and osteofibrous dysplasia are both benign fibro-osseous
lesions of the bone and are generally seen during childhood or adolescence.
Histologically, the features of these bone lesions sometimes look quite similar,
but their precise nature remains controversial. We retrospectively studied
clinicopathologic findings in 62 cases of fibrous dysplasia and 20 cases of
osteofibrous dysplasia with regard to their anatomic location and histological
appearance. From among these cases, the immunohistochemical expressions of c-fos
and c-jun proto-oncogene products and bone matrix proteins of type I collagen,
osteonectin, osteopontin, and osteocalcin were evaluated in 20 typical fibrous
dysplasias and 17 osteofibrous dysplasias using paraffin sections, and these
expressions were then assessed semiquantitatively. Microscopically, fibrous
dysplasia showed various secondary changes, such as hyalinization, hemorrhage,
xanthomatous reaction, and cystic change in 22 of the 62 cases (35%). This was a
higher incidence than in osteofibrous dysplasia, in which only 2 of the 20 cases
(10%) showed such changes. In the elderly fibrous dysplasia cases, the
cellularity of fibroblast-like cells was rather low, and those cases were
hyalinized. Almost all of the cases of fibrous dysplasia and osteofibrous
dysplasia showed positive expressions of c-fos and c-jun products. The
expressions of type I collagen and osteopontin showed no difference between
fibrous dysplasia and osteofibrous dysplasia. Immunoreactivity for osteonectin in
bone matrix was detected in only 1 case of fibrous dysplasia (1 of 20), whereas
it was recognized in 14 of the 17 cases of osteofibrous dysplasia. Furthermore,
the immunoreactivity for osteocalcin in bone matrix and fibroblast-like cells was
higher in fibrous dysplasia than it was in osteofibrous dysplasia,
semiquantitatively. Our immunohistochemical results regarding osteonectin and
osteocalcin suggest that the bone matrix of fibrous dysplasia is somewhat more
mature than that of osteofibrous dysplasia, and that the fibroblast-like cells in
fibrous dysplasia share some phenotypic features with osteoprogenitor cells of
normal osteogenic tissues. Fibrous dysplasia and osteofibrous dysplasia share
some similar histological features, including c-fos and c-jun expressions,
although different clinicohistologic features and immunohistochemical expressions
of osteonectin and osteocalcin were observed. These features suggest that the
mechanisms behind the development of fibrous dysplasia and osteofibrous dysplasia
are similar, but this is not necessarily indicative of a closer relationship
between the 2 diseases.
PMID- 10667419
TI - Decreased expression of protectin (CD59) in gut epithelium in ulcerative colitis
and Crohn's disease.
AB - Without adequate protection, the cells of the human body would be susceptible to
destruction by the complement system. The main defense against complement lysis
is a molecule called protectin (CD59) that is widely distributed in human
tissues. Because the complement system has been suggested to be involved in the
pathogenesis of inflammatory bowel diseases, we examined the expression of
protectin in the colonic epithelium of patients with ulcerative colitis or
Crohn's disease and controls. Colorectal specimens from 6 patients with
ulcerative colitis, 8 patients with Crohn's disease, and 4 controls were obtained
from surgical resections. Frozen sections of the specimens were immunostained for
protectin using the Bric 229 monoclonal antibody. The expression of protectin was
found to be decreased in the epithelium of patients with ulcerative colitis. In
patients with Crohn's disease, the epithelial expression of protectin was
decreased in diseased areas of gut while the expression did not significantly
differ from that in controls in macroscopically normal areas. There was no
difference in the expression of protectin on vascular endothelium, mononuclear
cells, or smooth muscle. The reduction in epithelial expression of protectin in
patients with ulcerative colitis or Crohn's disease may render epithelial cells
vulnerable to complement lysis and lead to the destruction of gut epithelium as
seen typically in these diseases.
PMID- 10667420
TI - Interobserver variability in application of the revised Sydney classification for
gastritis.
AB - The Sydney classification for gastritis provides guidelines for histological
grading of gastric biopsies. In an ongoing study of gastric preneoplastic lesions
in Chiapas, Mexico, 7 biopsies from 150 patients (4 from the antrum and 3 from
the body) were obtained during endoscopy and studied histologically. The first 74
endoscopy specimens were read independently by 2 general surgical pathologists.
We assessed diagnostic concordance using kappa statistics. The 2 pathologists
then jointly reviewed biopsies about which they had disagreed to reach a final
diagnosis. A second group of 76 endoscopies was subsequently evaluated
independently by the 2 pathologists, and concordance was again assessed. In the
first group of biopsies, we found low concordance rates (Heliobacter pylori 0.59,
acute inflammation 0.22, intestinal metaplasia 0.60, and atrophy 0.04). In the
second group, of independently reviewed cases, there was better concordance (H
pylori 0.77, acute inflammation 0.50, intestinal metaplasia 0.70, and atrophy
0.64). We presumed that use of the Sydney classification would result in minimal
interpretational differences achieving ideal kappas greater than 0.80. Because
pathology results are based on subjective interpretation of this classification,
complete diagnostic agreement is practically impossible. Concordance by general
surgical pathologists after joint review of cases was similar to that obtained by
gastrointestinal pathologists.
PMID- 10667421
TI - Molecular abnormalities associated with secretory carcinomas of the breast.
AB - Secretory carcinomas (SCAs) represent a unique histological variant of invasive
breast carcinomas, occurring predominantly in patients younger than 30 years of
age. Data from limited series have shown SCAs to have a favorable prognosis in
patients younger than 20 years of age, whereas the clinical course tends to
parallel the more common in filtrating ductal carcinomas (IDCs) in patients older
than 20 years. There are no reports on the molecular abnormalities associated
with this unusual tumor. Microdissected archival formalin-fixed tissue from 10
SCAs collected from 2 institutions were used to determine the frequencies of
allelic loss at 13 chromosomal regions with 19 microsatellite markers, using
multiplex polymerase chain reaction (PCR)-based techniques. The results of loss
of heterozygosity (LOH) and microsatellite alterations (MAs) analyses were
compared with 20 cases of IDCs. P53 gene mutation analysis was also performed on
the 10 SCAs using single-strand conformation polymorphism (SSCP) analysis,
followed by sequencing of abnormal bands. LOH at multiple regions of chromosome
3p were the most common abnormality in both SCAs (55%) and IDCs (50%), followed
by LOH at 17q21 (BRCA1 locus), 13q14 (retinoblastoma gene locus), and 8p21-23. No
significant differences were seen in the frequencies of LOH at any chromosomal
region except for 17p13 (p53 gene locus), where allelic losses were absent in
SCAs, but evident in 46% of IDCs (P < .05). The 2 histological entities were
similar in the fractional regional loss (FRL) index (0.26 v 0.24), fractional
allelic loss (FAL) index (0.23 v 0.27), as well as in the frequency of MAs (0.015
v 0.005), P > .05. P53 gene missense mutation (G:C::A:T) was detected in 1 of
10(10%) SCAs. Based on the considerable similarities in the molecular
abnormalities associated with both tumors, the formation of secondary lumina in
both the in situ and the invasive components, as well as suggestions from limited
series that the clinical behavior in adult patients parallels that of IDCs, SCA
most likely reflects a secretory variant of IDCs.
PMID- 10667422
TI - Crystal-storing histiocytosis: a disorder occurring in plasmacytic tumors
expressing immunoglobulin kappa light chain.
AB - Intracellular immunoglobulin crystal formation within plasma cells is an uncommon
finding in multiple myeloma and other lymphoplasmacytic tumors. We present 12
cases of plasmacytic tumors with prominent crystal formation, including myeloma
(5 cases), lymphoplasmacytic lymphoma (6 cases), and a nonneoplastic plasma cell
proliferation. In all cases, crystal formation was associated with the
proliferation of variable numbers of histiocytes containing similar inclusions.
These cases showed a variety of appearances, sometimes obscuring the underlying
plasma cell tumor and raising the differential diagnosis of a storage disorder,
hemophagocytosis, or a mesenchymal lesion. In cases of lymphoplasmacytic
lymphoma, patients typically presented with marked paraproteinemia and symptoms
of hyperviscosity. Crystal-storing histiocytosis was not associated with other
immunoglobulin deposition disorders, including amyloidosis, Mott cell tumors, or
kappa-light chain deposition. In our cases and those previously reported, we
found an overwhelming association of crystal-storing histiocytosis (CSH) with
tumors expressing immunoglobulin kappa light chain with no consistent association
with a particular heavy chain. These results suggest that CSH results from the
ingestion of crystals produced by plasma cell tumors that either overproduce
kappa light chain or express a structurally aberrant molecule. CSH persists in
the marrow and other sites throughout the course of the disease and in our series
was not highly associated with development of the adult Fanconi syndrome or rapid
clinical deterioration.
PMID- 10667423
TI - Colonic aberrant crypts may originate from impaired fissioning: relevance to
increased risk of neoplasia.
AB - Colonic aberrant crypt foci (ACF) can be identified on the unembedded mucosal
surface as clusters of abnormal crypts with enlarged, surface opening. Because
dysplasia is frequent, and may be a precursor of carcinoma, epithelial changes
have been well studied. However, the basis for the distinctive changes in crypt
architecture remain unclear. We hypothesized that some of the architectural
alterations of aberrant crypts may reflect impaired fissioning during normal
crypt duplication cycles. Fissioning begins at the crypt base. Using morphometric
and immunocytochemical approaches, we examined 55 human ACF, both dysplastic and
nondysplastic, for their architectural features. Non-ACF mucosa was compared.
Microscopically, all lesions contained crypts that were attached, paired,
dilated, and angulated. In 3 dimensions, these features related to multiple,
individual complexes of connected crypts, referred to as connected crypt
structures (CCSs). CCSs terminated in enlarged surface openings (2 to 5 x normal)
which are morphometrically equivalent to the macroscopic aberrant crypts (P >
.1). These openings trap marker dye. Support for an origin of CCSs in impaired
basal fissioning is 3-fold. Crypt profiles in ACF are twice as frequent in basal
mucosa as superficially (P < .001); in normal mucosa, the ratio is 1. In a CCS
with vertically connected, co-planar crypts, the upper parent crypt diameter was
the sum of diameters of inferiorly attached daughter crypts (P > .1).
Proliferating cell marker, Ki-67, is not expressed at attachment points. In non
ACF mucosa, isolated CCSs consistently occur at foci of mechanical crypt
distortion such as mucosal folds. We conclude that a CCS is a fundamental
component of ACF of all histotypes. Impairment of normal crypt fissioning is
probably a major factor in the histogenesis of CCSs, which often occurs in
settings of mechanical distortion of the mucosa. The pathological significance of
this process may be in the formation of enlarged crypt openings. The latter could
trap dietary carcinogens as they trap dye, and thereby predispose the CCS to
dysplasia.
PMID- 10667424
TI - Invasive micropapillary carcinoma of the breast: a prognostic study.
AB - Invasive micropapillary carcinoma (IMC) of the breast is a rare variant of
infiltrating ductal carcinoma that has been associated with an extremely high
incidence of lymph node metastases. Follow-up studies on patients with pure IMC
breast cancer histology have been limited by low patient numbers, short duration
of follow-up, and a lack of multivariate analyses. Using invasive breast cancers
from 1,287 patients (median follow-up, 13.8 years), histological review showed 21
cases (1.7%) with pure IMC histology. Pure IMC histology was associated with high
grade histology (P = .04), metastases to regional lymph nodes (P < .001), a high
mitotic index (P = .02), and erbB-2 immunopositivity (P = .007). Univariate
analyses showed a strong association between IMC histology and shortened survival
(disease-free survival [DFS], P = .0052; median, 44 months for IMC and 63 months
for non-IMC; disease-specific survival [DSS], P = .014; medians, 71 and 78 for
IMC and non-IMC, respectively) only in an analysis of all patients. Because only
1 case of node-negative IMC histology was available, univariate analysis of IMC
histology was performed only on node-positive patients without significance.
Multivariate analyses comparing IMC histology with either node-positive or all
other breast cancers failed to show independent prognostic significance. In
summary, breast cancer patients with pure IMC histology showed survival rates
similar to those of other patients with equivalent numbers of lymph node
metastases.
PMID- 10667425
TI - Extrathoracic solitary fibrous tumors: their histological variability and
potentially aggressive behavior.
AB - The histological variability of solitary fibrous tumors may contribute to the
difficulty in diagnosing these neoplasms, especially when they arise in
extrathoracic sites. Like intrathoracic lesions, the behavior of extrathoracic
solitary fibrous tumors is currently unpredictable because these types of tumor
have only recently been recognized. This study therefore was undertaken to
examine the clinical behavior and histological, immunohistochemical, and
ultrastructural features of 24 extrathoracic solitary fibrous tumors with long
term follow-up. The patients comprised 10 men and 14 women, between 30 and 85
years of age (mean, 51 years). Ten tumors were located in the retroperitoneum or
pelvis, 5 in the trunk, 4 in the extremities, 2 in the orbital region, and 1 each
in the kidney, uterine cervix, and meninges. All of the tumors showed a classic
morphological appearance, diffuse and strong immunoreactivity for both vimentin
and CD34, and variable reactivity for bcl-2. All 7 cases examined
ultrastructurally contained fibroblasts and myofibroblasts. Six tumors contained
multinucleated giant cells, and in 4 cases these lined pseudovascular spaces with
mononuclear cells, thus resembling giant cell angiofibroma and giant cell
fibroblastoma. Other potentially similar spindle cell neoplasms mixed with
adipose tissue, such as dendritic fibromyxolipoma, lipomatous hemangiopericytoma,
cellular angiofibroma, and spindle cell lipoma, were considered in the
differential diagnosis. One tumor displayed atypical histological features in the
form of increased cellularity and nuclear pleomorphism, but this patient has
remained free of disease for 14 years. Another 2 patients developed local
recurrences at 6 months and 5 years, and a further patient developed pulmonary
metastases that were diagnosed after 7 years. These tumors lacked any atypical
histological features in the primary lesions. No patient has so far died of the
disease. In conclusion, most extrathoracic solitary fibrous tumors appear to
pursue a benign course, although, because some have the potential to recur or
metastasize, careful long-term follow-up is necessary for all patients.
PMID- 10667426
TI - Demonstrability of the glycoprotein A-80 in postradiation prostatic carcinoma.
AB - Radiation therapy results in significant morphological changes in prostatic
carcinoma, including decreased cancer size, acinar shrinkage and distortion,
cytoplasmic vacuolization, and nuclear pyknosis. Benign acini usually display
enlarged, atypical cells with hyperchromatic nuclei. These changes confound the
evaluation of limited postradiation samples. The glycoprotein A-80 is known to be
upregulated in prostatic intraepithelial neoplasia (PIN) and prostatic carcinoma.
In this study, we assessed the expression of A-80 in radiation-treated prostatic
carcinoma. Paraffin sections from 64 postradiation prostatic carcinomas obtained
at salvage prostatectomy were immunostained with a monoclonal antibody to A-80;
selected sections were doubly immunostained with antibodies to A-80 and various
cytokeratin polypeptides. All cases showed readily detectable and often intense
staining in the cytoplasm of cancer cells and in intraluminal material of
malignant acini. The extent and intensity of the reactions were independent of
cancer size and grade. Strong reactions were seen in preserved and distorted
acini, clear cell areas, single cancer cells, and in colloid pools with few or no
recognizable cancer cells. PIN was present in 34 cases (53%), of which 27 (79%)
stained strongly for A-80; atrophic and hyperplastic acini generally did not
stain, irrespective of the degree of cellular atypia. The A-80 glycoprotein
appears remarkably durable and is readily demonstrable in postradiation prostatic
carcinoma despite profound architectural and cytologic changes. This
characteristic may prove useful in evaluating small samples for confirmation of
diagnosis and determination of extent of residual or recurrent prostatic
carcinoma after radiation therapy.
PMID- 10667427
TI - Living related liver transplantation: histopathologic analysis of graft
dysfunction in 304 patients.
AB - Between June 1990 and August 1997, 304 mainly pediatric patients underwent a
total of 311 orthotopic living related liver transplantations (LRLTs) under
tacrolimus immunosuppression at Kyoto University Hospital. Congenital biliary
atresia was the most common underlying disease. The donor was a parent, and the
left lateral segments were used as grafts in most cases. The average number of
loci of HLA-A, -B, and -DR mismatches between the donor and the recipient were
2.1. Forty-three transplants were ABO-incompatible. Liver histology at the time
of abnormal liver function after transplantation was analyzed. Preservation
injury was rare and mild. Acute cellular rejection (ACR) occurred in 36% of
transplants during the first 6 months. Average rejection activity index (the
Banff schema) was 4.2 and severe rejection was rarely seen. The number of
mismatching HLA loci and immunosuppression regimens affected the incidence of
ACR. Chronic rejection (CR) occurred in 2% of transplants. Concerning humoral
rejection, no hyperacute rejection was seen. However, hepatic artery thrombosis
(delayed hyperacute rejection) was seen in an ABO-incompatible transplant. Acute
hepatitis, including those related to cytomegalovirus and Epstein-Barr virus,
occurred in 17% of transplants. Chronic hepatitis, including hepatitis B and C,
developed in 3%. Acute or chronic cholangitis occurred in 16%, and a
significantly higher incidence of cholangitis was found in ABO-incompatible
transplants. Posttransplantation lymphoproliferative disease developed in 2%. In
LRLT, milder preservation injury and less frequent ACR and CR were suggested,
probably because of the short cold-ischemia time and the advantages of HLA
histocompatibility, respectively.
PMID- 10667428
TI - Significance of acid-mucin-positive nongoblet columnar cells in the distal
esophagus and gastroesophageal junction.
AB - Acidic mucin-positive nongoblet columnar cells (NGCC) have recently been observed
in the surface epithelium of the gastroesophageal junction (GEJ) and distal
esophagus in resections from patients with traditional long segment (>3 cm)
Barrett's esophagus (BE). However, the significance of finding acidic mucin
positive NGCC in the surface epithelium of biopsy specimens from the distal
esophagus/GEJ region in the absence of goblet cells (GC) remains unknown.
Therefore, to determine the significance of mucin histochemical changes in the
distal esophagus/GEJ region, we analyzed and compared the types, prevalence, and
distribution of neutral and acidic mucins in biopsy specimens obtained from 2
groups of patients: those with (32 patients) and those without (107 patients) GC
identified in this area. Various mucin histochemical stains (PAS-Ab pH 2.5, HID
Ab pH 2.5, PB/KOH/PAS) were used to identify neutral mucins, acidic mucins
(sialomucins and sulphomucins), and o-acetylated sialomucins. The results were
compared between the 2 patient groups and correlated with the clinical,
endoscopic, and pathologic features. Compared with patients without GC, patients
with GC had a significantly higher male/female ratio and a higher proportion of
patients with greater than 3 cm of columnar epithelium within the esophagus.
Acidic mucin (sialomucin and sulphomucin)-positive NGCC in the surface, foveolar,
and glandular epithelium did not show any correlation with any of the clinical,
endoscopic, or pathologic features, such as esophagitis, carditis, antritis,
Helicobacter pylori infection, or length of columnar epithelium in the distal
esophagus. However, acidic mucin-positive NGCC correlated strongly with the
presence of GC (P < .001). For example, sialomucin-positive NGCC were present in
28 of 32 (88%) patients with GC compared with 31 of 107 (29%) patients without GC
(P < .001). Similarly, sulphomucin-positive NGCC were present in 20 of 32 (62%)
patients with GC, compared with 11 of 107 (10%) patients without GC (P < .001).
Of the non-GC cases, all biopsy specimens that stained positively for sulphomucin
in surface NGCC (11 specimens), except one, showed staining restricted to the
surface of multilayered epithelium, a distinctive type of epithelium that shows
morphological, ultrastructural, and cytochemical features of both squamous and
columnar epithelium. Sialomucin positivity in surface NGCC from the distal
esophagus/GEJ region is a sensitive (sensitivity 88%), but nonspecific
(specificity 71%), indicator of GC metaplasia. In contrast, sulphomucin
expression in NGCC from the same anatomic area is a less sensitive (sensitivity
62%), but more specific (specificity = 90%) marker for the presence of
metaplastic epithelium, of either the GC or the multilayered epithelial cell type
and thus may represent an early or incomplete form of intestinal metaplasia.
PMID- 10667429
TI - Evidence of SV40 infections in hospitalized children.
AB - Simian virus 40 (SV40) is known to have contaminated poliovirus vaccines used
between 1955 and 1963. Accumulating reports have described the presence of SV40
DNA in human tumors and normal tissues, although the significance of human
infections by SV40 is unknown. We investigated whether unselected hospitalized
children had evidence of SV40 infections and whether any clinical correlations
were apparent. Serum samples were examined for SV40 neutralizing antibody using a
specific plaque reduction test; of 337 samples tested, 20 (5.9%) had antibody to
SV40. Seropositivity increased with age and was significantly associated with
kidney transplants (6 of 15 [40%] positive, P < .001). Many of the antibody
positive patients had impaired immune systems. Molecular assays (polymerase chain
reaction and DNA sequence analysis) on archival tissue specimens confirmed the
presence of SV40 DNA in 4 of the antibody-positive patients. This study, using 2
independent assays, shows the presence of SV40 infections in children born after
1980. We conclude that SV40 causes natural infections in humans.
PMID- 10667430
TI - Persistence of high-grade prostatic intra-epithelial neoplasia under combined
androgen blockade therapy.
AB - The presence and morphology of high-grade prostatic intraepithelial neoplasia (H
PIN) was blindly evaluated in 40 totally embedded radical prostatectomy specimens
of patients with prostate cancer randomized to either a 3 (n = 18) or 6 months (n
= 22) combined androgen blockade regimen before surgery. In 5 cases, neo-adjuvant
therapy was abrogated some time before surgery. In the remaining cases, foci of H
PIN were identified in 72% and 59% of prostates from patients treated for 3 and 6
months, respectively. Cellular features used to distinguish H-PIN from normal
glands were increased nuclear size, nuclear crowding, anisonucleosis, and
disordered nuclear arrangement. In some cases, density of cytoplasm was an
additional feature. Unfortunately, the molecular marker erbB2 proved unhelpful
for identification of H-PIN. The median number of prostatic glands involved by H
PIN was 19 +/- 21 (SD) glands in 3 months treated prostatectomies (n = 18) and 7
+/- 12 (SD) glands in 6 months treated prostatectomies (n = 17), a nonsignificant
difference (P = .17). H-PIN was localized within areas of residual carcinoma in
62% and 20%, respectively of prostatectomies of patients treated for 3 and 6
months, respectively. Architectural patterns of H-PIN differed at 3 and 6 months
of endocrine pretreatment: The predominant tufted pattern at 3 months was
replaced by flat H-PIN at 6 months. The continued expression of androgen
receptors and the cell cycle marker MIB-1 in persistent H-PIN suggests that
recovery of androgen levels after cessation of androgen blockade therapy will
lead to its further expansion.
PMID- 10667431
TI - LOH at the sites of the DCC, APC, and TP53 tumor suppressor genes occurs in
Barrett's metaplasia and dysplasia adjacent to adenocarcinoma of the esophagus.
AB - Barrett's esophagus carries a 30- to 100-fold increased risk of adenocarcinoma,
which is thought to develop via a metaplasia-dysplasia-carcinoma progression. A
common genetic abnormality detected in Barrett's adenocarcinoma is loss of
heterozygosity (LOH) at the sites of known or putative tumor suppressor genes, of
which there are at least 9 associated with esophageal adenocarcinoma. The aim of
this study was to identify at which histological stage of carcinogenesis LOH at
these sites occur. Microdissection of multiple paraffin-embedded tissue blocks
from 17 esophagogastrectomy specimens of adenocarcinoma arising in Barrett's
esophagus yielded areas of metaplasia, low-, intermediate- and high-grade
dysplasia, and carcinoma. LOH analysis of microdissected tissues was performed
using a double polymerase chain reaction technique with 11 microsatellite primers
shown previously to have LOH in at least 30% of esophageal adenocarcinomas.
Identical LOH was detected in premalignant and malignant tissues in 4 of 17
patients, and was located at 5q21-q22 (D5S346 primer), 17p11.1-p12 (TCF2 primer),
17p13.1 (TP53 primer), 18q21.1 (detected in colon cancer tumor suppressor gene
[DCC] primer), and 18q23-qter (D18S70 primer). These results suggest that LOH at
the sites of the DCC, adenomatous polyposis coli (APC), and TP53 tumor suppressor
genes occur before the development of adenocarcinoma in Barrett's esophagus, and
so merit further study as potential biomarkers of neoplastic progression in
patients with Barrett's esophagus undergoing endoscopic and histological
surveillance.
PMID- 10667432
TI - Myxoid liposarcoma with transition to round-cell lesion-cell cycle regulator
genes and telomerase activity characterizing tumor progression: a case report.
AB - A mixed myxoid/round cell liposarcoma was macrodissected in its 2 histologic
components and investigated for genetic differences between its low-grade myxoid
and the high-grade round-cell region. For both, we failed to detect p53 gene
mutations, loss of heterozygosity at the p53 or Rb genes, and p53 protein
expression. The round-cell component showed a high telomerase activity, and an
elevated c-myc mRNA and protein expression. The myxoid component was
characterized by a lack of telomerase activity and low c-myc mRNA expression, and
immunohistochemistry failed to detect the c-myc protein. There was a higher Mib-1
proliferation index in the round-cell portion. The same specific translocation
t(12;16) and the fusion transcript type II in both components confirmed the close
relationship between myxoid and round-cell liposarcomas. Telomerase activity and
increased c-myc expression seem to be helpful molecular markers for
characterizing tumor progression in myxoid liposarcoma.
PMID- 10667433
TI - A case of infantile rhabdomyofibrosarcoma with immunohistochemical,
electronmicroscopical, and genetic analyses.
AB - A case of infantile rhabdomyofibrosarcoma arising on the buttocks of a 15-month
old boy is reported with histological, immunohistochemical,
electronmicroscopical, and cytogenetic findings. Histological examination showed
a proliferation of spindle-shaped cells in a fasciculated pattern, with
occasional rounded rhabdomyoblastic cells with abundant eosinophilic cytoplasm.
Immunohistochemically, the tumor cells expressed desmin and MyoD1 but were only
weakly positive for myoglobin. No clear rhabdomyoblastic features were observed
by electronmicroscopic examination. Chromosome analysis showed a clone of 46, XY,
der(2)t(2;11)(q37;q13), different from any karyotypic abnormality in the original
report of this neoplasm. Loss of heterozygosity at 11p15.5, the most frequent
genetic alteration in embryonal rhabdomyosarcoma, was not detected. The low
degree of striated muscle differentiation and tumor localization supported the
diagnosis of infantile rhabdomyofibrosarcoma rather than spindle-cell
rhabdomyosarcoma in this case. The present case has been uneventful as of 25
months after surgery. The rather long recurrence-free period, which has not been
reported in previous cases, may be attributable to chemotherapy-induced rhabdoid
differentiation of the tumor cells.
PMID- 10667434
TI - Atypical spitz nevus/tumor.
PMID- 10667435
TI - Mucoid arteriosclerotic and nerve degenerative lesions in esophageal carcinoma.
PMID- 10667436
TI - Enucleation.
AB - The three most common indications for enucleation are intraocular malignancy,
trauma, and a blind, painful eye. Recommending enucleation is one of the most
difficult therapeutic decisions in ophthalmology. In some cases of malignancy,
cryotherapy, laser photocoagulation, diathermy, chemotherapy, and radiation
therapy may be viable alternatives to surgery. When surgery is chosen,
evisceration or exenteration may be alternatives to enucleation. Once the
decision is made to perform enucleation or evisceration, the surgeon must choose
from several types of implants and wrapping materials. These devices can be
synthetic, autologous, or eye-banked tissues. With certain implants, the surgeon
must decide when and if to drill for subsequent peg placement. In this review,
the authors discuss choices, techniques, complications, and patient consent and
follow-up before, during, and after enucleation. Controversies and results of the
Controlled Ocular Melanoma Study are summarized.
PMID- 10667437
TI - Anatomy of the orbital apex and cavernous sinus on high-resolution magnetic
resonance images.
AB - Diseases of the orbital apex and cavernous sinus usually present with involvement
of multiple cranial nerves, corresponding to the complex anatomy of the region.
In nontraumatic disorders, magnetic resonance imaging is the diagnostic modality
of choice. However, its capabilities can be fully used only with thorough
knowledge of the complicated topographic relationships in this region. This
article describes the imaging anatomy of the cranio-orbital junction and adjacent
subarachnoid spaces. High-resolution magnetic resonance images of normal subjects
are presented, and the results are compared with findings reported in the
literature. The following anatomic structures can be visualized on high
resolution magnetic resonance images: extraocular muscles and corresponding
connective tissue, major orbital and cerebral arteries, ophthalmic veins,
cavernous sinus, and all sensory and motor cranial nerves of the eye along their
intraorbital and intracranial course.
PMID- 10667438
TI - An unusual homonymous visual field defect.
AB - A 75-year-old man suddenly became aware of an inferior right homonymous visual
field defect. Although static perimetry suggested a lesion of the left lateral
geniculate nucleus, kinetic perimetry indicated that the presumed homonymous
horizontal sectoranopia noted on static perimetry was actually an incomplete
homonymous hemianopia with incomplete sparing of the temporal crescent. The
location of the lesion was subsequently confirmed by magnetic resonance imaging.
This case shows the value of kinetic perimetry in assessing homonymous visual
field defects.
PMID- 10667439
TI - Chiasmopathy?
AB - A 57-year-old man presented with progressive visual loss in both eyes, bitemporal
field defect, and a history of poor nutrition, alcohol abuse, and excessive cigar
smoking. Magnetic resonance imaging was normal. The visual acuity and field
defect improved with supplementation with vitamins and reduction of alcohol and
tobacco consumption. A diagnosis of toxic optic neuropathy was made. The authors
discuss the differential diagnosis of bitemporal/pseudobitemporal field defects
and the diagnosis and treatment of toxic optic neuropathy.
PMID- 10667440
TI - Leiomyoma of the ciliary body extending to the anterior chamber:
clinicopathologic and ultrasound biomicroscopic correlation.
AB - Leiomyoma of the ciliary body is a rare tumor that often causes a diagnostic
dilemma. Sclerouvectomy has been found to be beneficial in the management of iris
and ciliary body leiomyoma. We treated a case of leiomyoma of the ciliary body
presenting as a fleshy mass in the anterior chamber, removed by partial lamellar
sclerouvectomy. Ultrasound biomicroscopic and histopathologic features, including
light microscopic, immunohistochemistry, and transmission electron microscopic
features, were studied and the literature was reviewed.
PMID- 10667441
TI - A brief history of macular grids: from Thomas Reid to Edvard Munch and Marc
Amsler.
AB - Metamorphopsia is a symptom of retinal distortion from intrinsic retinal disease.
It has undoubtedly been experienced for millennia, but its clinical significance
has been appreciated only in modern times. The Norwegian painter Edvard Munch
recognized scotomas and metamorphopsia after suffering an intraocular hemorrhage
in his 60th year. Drawings made during this illness show his changing
perceptions, and also his attempts to document them with a grid of lines. The
Scottish philosopher Thomas Reid may have been the first to write about
metamorphopsia. He described distortion of his vision in 1764, after an episode
of sungazing, and recognized that the problem was probably of retinal origin.
Lines or grids to document metamorphopsia have appeared in ophthalmology
textbooks for more than 100 years, but testing for macular degeneration did not
become routine until the dissemination of Amsler's grids in the middle of the
20th century. This is in large measure a result of developments in ophthalmology
that made therapy for macular disease possible.
PMID- 10667442
TI - Measure for measure.
AB - Shakespeare's play Measure for Measure colorfully illustrates a concept that is
relevant to the testimonies given by the medical expert witness in the courtroom.
The expert should not ask the jury to hold the defendant physician to a higher
standard than that actually practiced by an acceptable reasonable minority of the
defendant's peers under similar circumstances. Two cases are presented.
PMID- 10667443
TI - The development of the code of ethics for the American Academy of Ophthalmology.
AB - The circumstances leading to and the process of establishing a code of ethics for
members of the American Academy of Ophthalmology are recounted by the original
chairman of the Ethics Committee.
PMID- 10667444
TI - Avoiding misplacement of blame for medical maloccurrence.
PMID- 10667445
TI - Managing retained intravitreal lens fragments after cataract surgery.
PMID- 10667446
TI - The placebo effect.
PMID- 10667447
TI - Hormones and cognition: current concepts and issues in neuropsychology.
AB - This article provides an extensive and comprehensive review of the effects of
hormones on cognition. Studies detailing specific neurocognitive functions
affected by variation in hormone levels across the life span are presented.
Dysregulation of hormone levels is considered from models of both normal and
diseased functioning. Patterns of cognitive dysfunction are described for a range
of syndromes involving the neuroendocrine system, and evidence of specific
neurophysiological mechanisms that can account for these findings is outlined.
This review includes discussion of treatment outcomes and the permanency of
endocrine-related cognitive dysfunction. The authors present a set of guidelines
for clinical neuropsychologists to use for assessment of patients with
neuroendocrine system dysfunction. Clinical and methodological issues in research
and treatment settings are discussed.
PMID- 10667448
TI - Quality of life and neurological illness: a review of the literature.
AB - This article highlights some of the conceptual and methodological problems
associated with quality of life (QoL) measurement in individuals with
neurological illness. It is suggested that these problems have contributed to the
underdeveloped status of QoL research in neurological settings. Many of the
existing QoL measures that have been used, or show potential for use with
individuals with neurological illness, are reviewed in terms of their theoretical
basis, content, and practicality. A large proportion of these measures fail to
meet adequate psychometric standards and/or have rarely been psychometrically
tested. The confusion that surrounds adequate psychometric standards is
discussed, and the dynamic nature of QoL is highlighted as a factor that requires
further attention. Research addressing the discrepancies between proxy and
patient ratings of patient QoL is also warranted. More focused research in these
areas may contribute to a clearer understanding of how to assess QoL in
individuals with neurological illness.
PMID- 10667449
TI - Cognitive event-related potentials in neuropsychological assessment.
AB - Neuropsychology is a behavioral approach to studying the brain, and an
integration of neuropsychology with on-line processing measures of brain function
is important for advancing the understanding of brain-behavior relationships.
Cognitive event-related potentials (ERPs) are on-line processing measures that
are of interest to neuropsychologists because they are linked to familiar
neuropsychological test paradigms and because they have reached a degree of
standardization sufficient to make them applicable in individual assessment. A
selective review of cognitive ERPs is given, focusing on studies of attention in
the oddball paradigm and arguing that an adequate assessment of attention is
basic in understanding higher order cognitive functions. General principles for
using ERP data to supplement and clarify neuropsychological analysis are
discussed, and available evidence on dementia and traumatic head injury is
reviewed. It is concluded that ERPs are a useful supplement to neuropsychological
assessment. Although diagnostic use of ERPs must be guarded because of limited
standardization and validation, information-processing analysis with ERPs may aid
significantly in interpretation of behavioral data.
PMID- 10667450
TI - The search for circadian clock and sleep genes.
AB - In recent years, there has been extraordinary progress in elucidating the
molecular components of the mammalian circadian clock system. The discovery of
circadian clock genes in lower organisms (such as fruit flies and fungi), which
show many similarities with clock genes in mammals, together with advances in
mouse molecular genetics have led to major new discoveries on the molecular and
genetic basis of mammalian circadian rhythms. This article reviews both of these
lines of research from an historical perspective and discusses how these lines
have merged to provide unique insights into the molecular mechanisms of circadian
function. The review also speculates on how the discovery of circadian clock
genes may lead directly or indirectly to the discovery of mammalian sleep genes.
The determination of the molecular mechanisms via which circadian clock genes
(and their protein products) regulate the timing and the need for sleep, and the
identification of new genes involved in sleep regulation, may produce new
information on the genetic and molecular control of sleep which could ultimately
lead to the development of new treatments for sleep disorders.
PMID- 10667451
TI - New insights into the mechanism of action of hypnotics.
AB - Between 1987 and 1989, the different protein subunits that make up the receptor
for the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) were
identified. These make up the alpha, beta, gamma and delta families, for each of
which exist several subtypes. This receptor is the molecular target of modern
hypnotic drugs (i.e. benzodiazepines, zopiclone, zolpidem and zaleplon). In the
10 years that have followed this milestone, significant progress has been made in
exploring the molecular mechanisms of hypnotic drug action. Receptor subtype
specificity of hypnotics has been explained in terms of differential affinity for
receptors containing different alpha subunits, which are expressed in different
brain regions. Zolpidem and zaleplon bind preferentially to alpha1-containing
receptors, whereas benzodiazepines and zopiclone are aspecific. Different sets of
subunits are encoded in contiguous 'cassettes' on the genome, and the
transcription of each set appears to be regulated coherently. The predominant
GABA(A) receptor composition found in the brain is alpha1beta2gamma2, which are
all encoded on human chromosome 5. Targeted gene disruption has provided clues to
the physiological functions served by GABA(A) receptors containing different
subunits. Receptors containing gamma2 appear to have a vital role in maintaining
appropriate central inhibition, beta3-containing receptors may also be important
determinants of excitability in certain brain regions, whereas a clear role for
alpha5-, alpha6- and gamma3-containing receptors has not yet been established by
these techniques. Site-directed mutagenesis has indicated that benzodiazepines
bind to a cleft on the GABA(A) receptor surface at the interface between the
alpha and gamma subunits. Other drugs (flumazenil, zopiclone, zolpidem) also bind
to the a subunit, but interact with amino acids in different binding domains to
the benzodiazepines. The molecular mechanism of hypnotic dependence has been
explored, and seems to involve downregulation of transcription of the normally
prevalent alpha1, beta2 and gamma2 subunits, and the reciprocal upregulation of
the expression of rarer subunits. Chronic treatment with hypnotic drugs that may
have less dependence potential, such as zopiclone and zolpidem, appears to
produce more limited change in GABA(A) receptor subunit expression. These ideas
will be important both for designing new hypnotic drugs with a better
safety/efficacy profile, and for evaluating more appropriate ways of using the
drugs available today.
PMID- 10667452
TI - Evaluation of severe insomnia in the general population: results of a European
multinational survey.
AB - The epidemiology of severe insomnia and its effect on quality of life and
healthcare consumption was assessed in a survey of the general population of five
northern European countries. Applying established consumer sampling techniques,
insomnia sufferers were selected from the general population using a
questionnaire, conducted by face-to-face interview, and severity of insomnia was
ranked (severe, mild/moderate, no sleep complaint) using a specific algorithm.
Population samples were matched according to case control methodology for age,
gender and geographical region. A second questionnaire gathered information on
sleep problems, quality of life (SF-36 scores) and healthcare consumption. The
prevalence of severe insomnia ranged from 4% to 22%, was higher in females than
in males, but did not increase significantly with age. Patients with severe
insomnia had been experiencing sleeping problems for a median of 2-6 years. In
all countries, insomnia had a negative impact on quality of life, and the degree
of impairment in quality of life was directly related to the severity of
insomnia. Individuals with severe insomnia also showed a higher level of
healthcare consumption. Despite this, severe insomnia did not appear to feature
prominently in the doctor-patient relationship.
PMID- 10667453
TI - Brain mechanisms of sleep: contribution of neuroimaging techniques.
AB - Functional brain neuroimaging essentially relies on two basic principles:
functional segregation and functional interaction. Recent studies of the
functional segregation of the human brain during sleep, using positron emission
tomography and statistical parametric mapping, indicate that human brain function
is organized in a very specific way in each state of vigilance. During slow wave
sleep, the most deactivated areas are the upper brainstem, thalamic nuclei and
basal forebrain; deactivation of the basal ganglia is also seen. In the cortex,
the least active areas are the associative cortices of the frontal and parietal
cortex. The anatomical extent of this deactivation remains uncertain. In rapid
eye movement (REM) sleep there is significant activation of the dorsal tegmentum
of the ponto-mesencephalic region and the thalamic nuclei. Within the cortex, the
limbic areas (amygdala, hippocampus, orbito-frontal cortex and anterior cingulate
cortex) are activated. In contrast, the associative areas of the frontal and
parietal cortices are less active than other parts of the brain. The functional
interactions between the amygdala and the temporal cortex during REM sleep differ
markedly from those during other states of vigilance, and there is also an
inverse relationship between the activities of the primary and secondary visual
areas.
PMID- 10667454
TI - Evaluation of severe insomnia in the general population--implications for the
management of insomnia: focus on results from Ireland.
PMID- 10667455
TI - Evaluation of severe insomnia in the general population--implications for the
management of insomnia: the German perspective.
PMID- 10667456
TI - Evaluation of severe insomnia in the general population--implications for the
management of insomnia: focus on results from Belgium.
PMID- 10667457
TI - Evaluation of severe insomnia in the general population--implications for the
management of insomnia: the UK perspective.
PMID- 10667458
TI - Evaluation of severe insomnia in the general population--implications for the
management of insomnia: insomnia, quality of life and healthcare consumption in
Sweden.
PMID- 10667459
TI - New trends in insomnia management.
AB - Pharmacological management of insomnia is continually evolving. The introduction
of non-benzodiazepine benzodiazepine receptor agonist hypnotics provides an
opportunity to understand different patterns of pharmacological activity with
mechanistic differences in receptor activity. The impact of insomnia on daytime
functioning and long-term health and socioeconomic status has been recognized.
Epidemiological studies indicate that insomnia is associated with increased
absenteeism and healthcare costs (although the latter appear to be partly
attributable to comorbid depression). It will thus be important to determine
whether hypnotics, in addition to their effects on sleep, provide other benefits
for the patient that are related to these parameters. The successful resolution
of this issue will require the adoption of additional outcome measures, such as
effects on quality of life and healthcare costs. Recognition that long-term
hypnotic use is widespread among insomniacs has prompted proposals for
alternative prescribing patterns. Although certain hypnotics appear to be free of
tolerance on prolonged use, caution is required in the long-term use of any
hypnotic because of the lack of systematic data on chronic efficacy and safety.
Therefore, alternative administration schedules (e.g. intermittent and 'as
required') are being investigated. These may have very different consequences in
terms of abuse liability and patients' perceptions of efficacy, and thus permit a
more effective and appropriate use of this drug class.
PMID- 10667460
TI - Genetic polymorphism of CYP genes, alone or in combination, as a risk modifier of
tobacco-related cancers.
AB - Tobacco use is causally associated with cancers of the lung, larynx, mouth,
esophagus, kidneys, urinary tract, and possibly, breast. Major classes of
carcinogens present in tobacco and tobacco smoke are converted into DNA-reactive
metabolites by cytochrome P450 (CYP)-related enzymes, several of which display
genetic polymorphism. Individual susceptibility to cancer is likely to be
modified by the genotype for enzymes involved in the activation or detoxification
of carcinogens in tobacco and repair of DNA damage. We summarize here the results
of case-control studies published since 1990 on the effects of genetic variants
of CYP1A1, 1A2, 1B1, 2A6, 2D6, 2E1, 2C9, 2C19, 17, and 19 alone or in combination
with detoxifying enzymes as modifiers of the risk for tobacco-related cancers.
The results of studies on gene-gene interactions and the dependence of smoking
related DNA adducts on genotype were also analyzed. Some CYP variants were
associated with increased risks for cancers of the lung, esophagus, and head and
neck. The risk was often increased in individuals who also had GSTM1 deficiency.
For breast cancer in women, a few studies suggested an association with CYPs
related to metabolism of tobacco carcinogens and steroidal hormones. The overall
effects of common CYP polymorphisms were found to be moderate in terms of
penetrance and relative risk, with odds ratios ranging from 2 to 10. Some
CYP1A1/GSTM1 0/0 genotype combinations seem to predispose the lung, esophagus,
and oral cavity of smokers to an even higher risk for cancer or DNA damage,
requiring, however, confirmation. Future strategies in molecular cancer
epidemiology for identifying such susceptible individuals are discussed with
emphasis on well-designed larger studies.
PMID- 10667461
TI - Molecular genetics and epidemiology of the NAT1 and NAT2 acetylation
polymorphisms.
AB - The focus of this review is the molecular genetics, including consensus NAT1 and
NAT2 nomenclature, and cancer epidemiology of the NAT1 and NAT2 acetylation
polymorphisms. Two N-acetyltransferase isozymes, NAT1 and NAT2, are polymorphic
and catalyze both N-acetylation (usually deactivation) and O-acetylation (usually
activation) of aromatic and heterocyclic amine carcinogens. Epidemiological
studies suggest that the NAT1 and NAT2 acetylation polymorphisms modify risk of
developing urinary bladder, colorectal, breast, head and neck, lung, and possibly
prostate cancers. Associations between slow NAT2 acetylator genotypes and urinary
bladder cancer and between rapid NAT2 acetylator genotypes and colorectal cancer
are the most consistently reported. The individual risks associated with NAT1
and/or NAT2 acetylator genotypes are small, but they increase when considered in
conjunction with other susceptibility genes and/or aromatic and heterocyclic
amine carcinogen exposures. Because of the relatively high frequency of some NAT1
and NAT2 genotypes in the population, the attributable cancer risk may be high.
The effect of NAT1 and NAT2 genotype on cancer risk varies with organ site,
probably reflecting tissue-specific expression of NAT1 and NAT2. Ethnic
differences exist in NAT1 and NAT2 genotype frequencies that may be a factor in
cancer incidence. Large-scale molecular epidemiological studies that investigate
the role of NAT1 and NAT2 genotypes and/or phenotypes together with other genetic
susceptibility gene polymorphisms and biomarkers of carcinogen exposure are
necessary to expand our current understanding of the role of NAT1 and NAT2
acetylation polymorphisms in cancer risk.
PMID- 10667462
TI - Single-dose administration of Bowman-Birk inhibitor concentrate in patients with
oral leukoplakia.
AB - The Bowman-Birk inhibitor (BBI) is a soybean-derived serine protease inhibitor
and a potential cancer chemopreventive agent for humans. In this Phase I clinical
trial, BBI concentrate was administered as a single oral dose to 24 subjects with
oral leukoplakia. Pharmacokinetics of BBI was analyzed, and subjects were
monitored clinically for toxic effects. Subjects received between 25 and 800
chymotrypsin inhibitor units (CIU) of the compound in a dose escalation trial.
BBI was taken up rapidly, and a metabolic product of BBI was excreted in the
urine within 24-48 h. No clinical or laboratory evidence of toxicity was observed
in the study. Protease activity was also measured in buccal cells to evaluate
usefulness as a biomarker. Single-dose BBI concentrate administered up to 800 CIU
was well tolerated and appeared to be nontoxic. Further investigation in Phase II
clinical trials is being done.
PMID- 10667463
TI - Selenium modulation of cell proliferation and cell cycle biomarkers in normal and
premalignant cells of the rat mammary gland.
AB - The present study was designed to assess the effect of Se-methylselenocysteine or
triphenylselenonium chloride treatment on cell proliferation [bromodeoxyuridine
(BrdUrd) labeling] and cell cycle biomarkers [proliferating cell nuclear antigen
(PCNA), cyclin D1, and p27/Kip 1] in the intact mammary gland of rats.
Immunohistochemical assays of the above end points were carried out in different
morphological structures: (a) terminal end bud cells and alveolar cells of a
maturing mammary gland undergoing active differentiation; and (b) premalignant
mammary intraductal proliferations (IDPs) identified at 6 weeks after carcinogen
dosing. Neither compound was found to affect BrdUrd labeling or the expression of
cell cycle biomarkers in the normal terminal-end bud cells and alveolar cells. Se
methylselenocysteine reduced the total number of IDP lesions by approximately
60%. Interestingly, this was not accompanied by decreases in BrdUrd labeling or
the proportion of IDP cells expressing PCNA and cyclin D1. An enhancement in the
fraction of p27/Kip 1-positive IDP cells, however, was detected as a result of Se
methylselenocysteine treatment. Although triphenylselenonium chloride did not
reduce the total number of IDPs, there were more of the smaller-sized lesions and
fewer of the larger-sized lesions compared with those found in the control group.
Triphenylselenonium chloride also significantly decreased the proportion of IDP
cells incorporating the BrdUrd label or expressing PCNA and cyclin D1. The above
findings suggest that early transformed cells are sensitive to selenium
intervention, whereas normal proliferating cells are not. It is possible that Se
methylselenocysteine blocks carcinogenesis by a pathway that may not involve cell
growth inhibition as a primary response; in contrast, triphenylselenonium
chloride is likely to act by a cytostatic mechanism. The data also imply that
selenium efficacy testing in intervention trials is possible with the use of
biomarkers, provided that the appropriate biomarkers are matched with the
selenium compound of interest and that the pathological characteristics of the
cell population to be evaluated are taken into consideration.
PMID- 10667464
TI - Breast adipose tissue concentrations of polychlorinated biphenyls and other
organochlorines and breast cancer risk.
AB - Numerous studies have examined the relationship between organochlorines and
breast cancer, but the results are not consistent. In most studies,
organochlorines were measured in serum, but levels in breast adipose tissue are
higher and represent cumulative internal exposure at the target site for breast
cancer. Therefore, a hospital-based case-control study was conducted in Ontario,
Canada to evaluate the association between breast cancer risk and breast adipose
tissue concentrations of several organochlorines. Women scheduled for excision
biopsy of the breast were enrolled and completed a questionnaire. The biopsy
tissue of 217 cases and 213 benign controls frequency matched by study site and
age in 5-year groups was analyzed for 14 polychlorinated biphenyl (PCB)
congeners, total PCBs, and 10 other organochlorines, including p,p'-1,1-dichloro
2,2-bis(p-chlorophenyl)ethylene. Multiple logistic regression was used to assess
the magnitude of risk. While adjusting for age, menopausal status, and other
factors, odds ratios (ORs) were above 1.0 for almost all organochlorines except
five pesticide residues. The ORs were above two in the highest concentration
categories of PCB congeners 105 and 118, and the ORs for these PCBs increased
linearly across categories (Ps for trend < or =0.01). Differences by menopausal
status are noted especially for PCBs 105 and 118, with risks higher among
premenopausal women, and for PCBs 170 and 180, with risks higher among
postmenopausal women. Clear associations with breast cancer risk were
demonstrated in this study for some PCBs measured in breast adipose tissue.
PMID- 10667465
TI - Risk of breast cancer according to the status of HER-2/neu oncogene
amplification.
AB - We examined risk factors for breast cancer after subdividing cases based on the
presence of HER-2/neu oncogene amplification in their tumors. Data were from the
Carolina Breast Cancer Study, a population-based, case-control study of 577
invasive breast cancer patients, diagnosed during 1993-1996 and ages 20-74 years,
and 790 controls frequency-matched on race and age. Information on breast cancer
risk factors was obtained from structured personal interviews. About 20% of
paraffin-embedded tissues from the breast cancers of cases were identified as
positive for HER-2/neu amplification (HER-2/neu+) by differential PCR. Early age
at menarche, higher waist:hip ratio, and family history of breast or ovarian
cancer were associated with elevated odds ratios (ORs) for both HER-2/neu+ and
HER-2/neu- breast cancers. Breastfeeding for at least 1 year was inversely
associated with HER-2/neu+ breast cancer [OR, 0.3; 95% confidence interval (CI),
0.1-0.7] more so than HER-2/neu- breast cancer (OR, 0.8; 95% CI, 0.5-1.2). Most
of the remaining risk factors had ORs around 1.0 for both HER-2/neu+ and HER
2/neu- breast cancers, although a few exhibited possible associations with one
disease subtype in analyses stratified by menopausal status. These study results
suggest that most recognized breast cancer risk factors do not operate through
HER-2/neu amplification in breast carcinogenesis. Differential effects of long
term breastfeeding by HER-2/neu amplification status have been observed in
earlier studies and are provocative; however, the direction and magnitude of the
associations have not been consistent.
PMID- 10667466
TI - GSTT1 and GSTM1 null genotypes and the risk of gastric cancer: a case-control
study in a Chinese population.
AB - Glutathione S-transferase (GST) enzymes are involved in detoxification of many
potentially carcinogenic compounds. The homozygous deletions or null genotypes of
GSTT1 (theta class) and GSTM1 (mu class) genes may be associated with an
increased risk of cancer. Few studies have evaluated the relationship between
GSTT1, GSTM1 and the risk of gastric cancer, as well as the potential
interactions between these genetic markers and other risk factors of gastric
cancer in the Chinese population. We conducted a case-control study with 143
cases with gastric cancer, 166 chronic gastritis (CG) cases and 433 cancer-free
population controls from Yangzhong County, China. The epidemiological data were
collected by a standard questionnaire for all of the subjects, and blood samples
were obtained from 91 gastric cancer cases, 146 CG cases, and 429 controls. GSTT1
and GSTM1 genotypes were assayed by the PCR method, and Helicobacter pylori
infection was measured by the ELISA method. Using logistic regression model in
SAS, we assessed the independent effects of GSTT1 and GSTM1 null genotypes on the
risk of gastric cancer and their potential interactions with other factors. The
prevalence of GSTM1 null genotype was 48% in gastric cancer cases, 60% in CG
patients, and 51% in controls. The prevalence of GSTT1 null genotype was 54% in
gastric cancer cases, 48% in CG patients, and 46% in controls. After controlling
for age, gender, education, pack-years of smoking, alcohol drinking, body mass
index, H. pylori infection, and fruit and salt intake, the adjusted odds ratio
(OR) for GSTT1 and gastric cancer was 2.50 (95% confidence interval (CI), 1.01
6.22). When gastric cancer cases were compared with CG patients, the adjusted OR
for GSTT1 was 2.33 (95% CI, 0.75-7.25). However, GSTT1 null genotype was not
associated with the risk of CG when using population controls. No obvious
association was found between GSTM1 and the risk of both gastric cancer and CG.
Our results suggest that GSTT1 null genotype may be associated with an increased
risk of gastric cancer in a Chinese population.
PMID- 10667467
TI - A new ELISA kit for measuring urinary 2-hydroxyestrone, 16alpha-hydroxyestrone,
and their ratio: reproducibility, validity, and assay performance after freeze
thaw cycling and preservation by boric acid.
AB - There is considerable controversy regarding the role of estrogen metabolites in
breast cancer risk, fueled in part by the development of a rapid ELISA that is
suitable for large scale investigations. An earlier version of the ELISA could
detect values of the 2-hydroxyestrone (2-OHE1) and 16alpha-hydroxyestrone
(16alpha-OHE1) metabolites as low as 2 ng/ml and produce consistent results in
premenopausal urines. However, reproducibility was problematic in postmenopausal
urines where concentrations of these compounds are much lower. In response to our
concern, a new ELISA was developed with a sensitivity of 0.625 ng/ml, which we
evaluated using the same pre- and postmenopausal urine samples analyzed in the
earlier ELISA. In this report, we present findings on the new kit with regard to
reproducibility of the 2-OHE1 and 16alpha-OHE1 measurements, comparability of
results with gas chromatography-mass spectroscopy values, and with regard to the
stability of the metabolites after repeated freeze-thaw cycles and after
preservation by boric acid. For the most part, we found the new ELISA to be
reproducible, with assay coefficients of variation ranging from 10 to 20%, and
intraclass correlation coefficients (ICCs) ranging from 80 to 95% in both the pre
and postmenopausal urines. ELISA results for 16alpha-OHE1 differed from 1 day
(i.e., batch) to the next, and the absolute values of the metabolites obtained by
the ELISA were consistently lower than but well correlated with those obtained by
gas chromatography-mass spectroscopy. Values of the 2-OHE1:16alpha-OHE1 ratio
also differed between the methods, but because the range of values was not large,
the magnitude of these differences was not as great. For the ratio, the
correlation between methods was excellent, and the ICCs were high for both groups
of women. After preservation by boric acid, values of the ratio varied according
to acid concentration but not in a linear fashion. Ratio values were similar in
urine samples exposed to four different freeze-thaw cycle treatments, although
values for all treatments were consistently lower in one batch. Because batch-to
batch variability was not negligible, it is advisable that matched cases and
controls be analyzed in the same batch. Provided this is done, the relatively low
assay coefficient of variation and high ICC demonstrate that the new ELISA kit
can reliably measure the 2-OHE1:16alpha-OHE1 ratio and detect small case-control
differences in large population-based studies, where rapid and relatively easy
laboratory methods are critical.
PMID- 10667468
TI - Behavioral risk factors among women presenting for genetic testing.
AB - Considerable research attention has been given to the impact of genetic testing
on psychological outcomes. Participation in genetic testing also may impact on
health behaviors that increase the risk of cancer and other chronic diseases. The
purpose of this study is to describe behavioral cancer risk factors of women who
requested genetic testing for breast and ovarian cancer susceptibility (BRCA1,
BRCA2). Before participation in a genetic testing program, 119 women completed a
series of questionnaires designed to assess their health behaviors, perception of
risk, and depressive symptomatology. Eight percent of participants were current
smokers, 27% did not engage in at least moderate exercise, 46% did not regularly
protect themselves from the sun, 39% did not consume at least five servings of
fruits and vegetables per day, and 9% drank at least one alcoholic beverage per
day. Poisson regression analysis revealed that age was the only predictor of
behavioral risk profiles, with older women having fewer cancer risk behaviors.
These patients who presented for genetic testing generally had better health
behaviors than the general population. However, given their possible high-risk
status, these patients should consider further improving their preventable cancer
risk factors and, in particular, their diet, sun protection, and physical
activity levels. Inclusion of behavioral risk factor counseling in the context of
the genetic testing process may be an important opportunity to reach this at-risk
population.
PMID- 10667469
TI - A case-control study of galactose consumption and metabolism in relation to
ovarian cancer.
AB - Consumption or metabolism of dairy sugar and ovarian cancer have been linked
based on evidence that galactose may be toxic to ovarian germ cells and that
ovarian cancer is induced in animals by depletion of oocytes. We assessed
consumption of dairy products and obtained blood for biochemical and molecular
genetic assessment of galactose metabolism in 563 women with newly diagnosed
epithelial ovarian cancer and 523 control women selected either by random digit
dialing or through lists of residents in eastern Massachusetts and New Hampshire.
We observed no significant differences between cases and controls in usual
consumption of various types of dairy products or total daily lactose (the
principal source of galactose in the diet); nor did we find that RBC activity of
either galactose-1-phosphate uridyl transferase (GALT) or galactokinase differed.
The mean (and SE) activity of uridine diphospho-galactose 4'-epimerase (in
micromoles per hour per gram of hemoglobin) was, however, significantly lower (P
< 0.005) in cases compared with controls, 20.32 (0.31) versus 21.64 (0.36).
Ovarian cancer cases were also more likely to carry the N314D polymorphism of the
GALT gene, generally predisposing to lower GALT activity. The difference was most
evident for endometrioid and clear cell types of ovarian cancer, in which 3.9% of
cases were found to be homozygous for N314D compared with 0.4% of controls,
yielding an odds ratio and 95% confidence interval of 14.17 (2.62-76.60). We
conclude that, whereas adult consumption of lactose carries no clear risk for the
disease, certain genetic or biochemical features of galactose metabolism may
influence disease risk for particular types of ovarian cancer.
PMID- 10667470
TI - Cancer risk estimates for family members of a population-based family registry
for breast and ovarian cancer.
AB - Population-based breast and ovarian cancer family registries can facilitate
studies to evaluate genetic and environmental factors in the etiology of these
malignancies. The purpose of this study is to describe what is, as far as we
know, the first population-based breast and ovarian cancer family registry and to
estimate breast and ovarian cancer risk in relatives of breast and ovarian cancer
probands. Population-based consecutive incident cases of breast and ovarian
cancer were invited to participate in the University of California, Irvine breast
and ovarian family registry. In this study, we report data on 1567 breast cancer
and 328 ovarian cancer probands. The operational components of this family
registry include enrollment of probands, family history interviewing,
confidentiality, pathology, verification and review, biospecimen bank,
statistical/genetic analysis, and special studies on positional cloning of known
genes. All of the components are tracked through the University of California,
Irvine Genetic Research Information System. In non-Hispanic-white breast cancer
probands, relative risk (RR) of breast cancer in mothers and sisters is
significantly elevated [RR = 1.7 and 95% confidence interval (CI) = 1.4-2.0 and
RR = 2.8 and 95% CI = 2.3-3.3, respectively]. In families of ovarian cancer
probands, mothers are at increased risk of ovarian cancer (RR = 4.6; 95% CI, 2.1
8.7). RR of breast cancer in mothers of Hispanic breast cancer probands is
significantly elevated (RR = 4.9; 95% CI, 2.6-8.5). No elevation of breast or
ovarian cancer risk was observed among relatives of Asian probands. In general,
there is a decrease in RR among mothers and sisters with increase in age of onset
of probands. In second-degree relatives and first cousins, the breast cancer
hazards ratios increase with increase in the number of affected first-degree
relatives and decrease with increase in age at onset of the proband.
PMID- 10667471
TI - Diets containing whey proteins or soy protein isolate protect against 7,12
dimethylbenz(a)anthracene-induced mammary tumors in female rats.
AB - A study was conducted to determine the protective effects of two common dietary
proteins, soy protein isolate (soy) and bovine whey, against chemically induced
mammary tumors in female Sprague Dawley rats. Rats were fed AIN-93G diets having
casein, soy, or whey as the sole protein source. Rats within the same dietary
groups were mated to obtain the F1 and F2 generations. At age 50 days, F1
(experiment A) or F2 (experiment B) female offspring (> or =19 rats/group) were
p.o. gavaged with 80 mg/kg 7,12-dimethylbenz(a)anthracene, and mammary glands
were evaluated when 100% of the casein-fed group developed at least one palpable
tumor. Rats grew well on all three diets, but casein-fed rats gained slightly
more body weight than soy- or whey-fed rats (P < 0.05). Vaginal opening occurred
1 day earlier in soy-fed rats than in casein- or whey-fed rats, but no other
differences in reproductive and developmental parameters were observed between
groups. When 50% of the casein-fed rats had at least one mammary tumor, lower
tumor incidences (24-34%) were observed in the soy-fed (P < 0.009) and whey-fed
groups (P < 0.001). When 100% of the casein-fed rats had at least one tumor, soy
fed rats had a lower tumor incidence (77%) in experiment B (P < 0.002), but not
in experiment A (P < 0.12), and there were no differences in tumor multiplicity.
Whey-fed rats had lower mammary tumor incidence (54-62%; P < 0.002) and
multiplicity (P < 0.007) than casein-fed rats in both experiments. Our results
indicate that diets rich in soy reduce the incidence of chemically induced
mammary tumors by approximately 20%. Furthermore, whey appears to be at least
twice as effective as soy in reducing both tumor incidence and multiplicity.
PMID- 10667472
TI - Nonsteroidal anti-inflammatory drugs and risk of digestive cancers at sites other
than the large bowel.
AB - Regular continuing nonsteroidal anti-inflammatory drug (NSAID) use has been
associated with a reduction in risk of large bowel cancer in many studies,
including our Case-Control Surveillance Study of medication use and cancer risk.
We assessed the relation of NSAID use to the risk of digestive cancers at sites
other than the large bowel in this database. Nurse-interviewers administered
questionnaires to patients admitted to hospitals in four centers from 1977 to
1998. Cases comprised 1149 patients with cancers of the pancreas (n = 504),
stomach (n = 254), esophagus (n = 215), gallbladder (n = 125), or liver (n = 51).
Controls were 5952 patients admitted for trauma or acute infection. History of
NSAID use was elicited by questions about indications for use. Multiple logistic
regression models were used to calculate odds ratios (ORs) for categories of
regular NSAID use (at least 4 days/week for at least 3 months) relative to never
use. The OR for regular use initiated at least 1 year before admission and
continuing into that year was reduced for stomach cancer (OR = 0.3; 95%
confidence interval, 0.1-0.6) and was compatible with 1.0 for other sites. The
ORs for regular continuing use of at least 5 years duration were < 1.0 for
cancers of the stomach, pancreas, esophagus, and gallbladder but were
statistically significant only for stomach cancer. These data suggest that
regular continuing NSAID use may be associated with reduced risk of stomach
cancer. For the other sites, the data are consistent with no effect of NSAID use.
PMID- 10667473
TI - Analytical and clinical evaluation of TSH and thyroid hormones by
electrochemiluminescent immunoassays.
AB - OBJECTIVES: To perform an analytical evaluation of the new
electrochemiluminescent immunoassays (ECLIA) for TSH, FT4, and T3 in the Elecsys
2010 immunoassay system. To assess the clinical classification of patients under
suspicion of thyroid disease based on these laboratory assays. MATERIALS AND
METHODS: The analytical evaluation included the performance of minimum detectable
concentrations, within-assay and inter-assay precision for the three analytes,
functional sensitivity and linearity studies for TSH, and method comparison with
the previous methods of RIA for FT4 and T3, and IRMA for TSH in current protocols
of our institution. 102 patients with clinical suspicion of thyroid disease were
assayed by ECLIA and radioactive techniques. Their differential clinical
classification based on laboratory tests was studied as well. RESULTS: The
minimum detectable concentrations coincided with the manufacturer's: <0.005 mU/L
for TSH, <0.30 pmol/L for FT4, and <0.30 nmol/L for T3. Functional sensitivity
for TSH was 0.044 mU/L. Over the analytical range tested, within-assay
imprecision was below 3.2% for TSH, 2.2% for FT4 and 9.6% for T3, and interassay
CVs were below 4.0% for TSH, 5.9% for FT4 and 12.9% for T3. Measurement of
diluted sera showed the TSH assay to overestimate recoveries by 18.6%. We have
compared sera results of the Elecsys ECLIA assays with those obtained from the
IRMA (Spectria-Orion Diagnostica) for TSH: TSH (ECLIA) = 0.074+0.953 TSH (IRMA),
(r = 0.974; Sy/x = 2.638), and RIA (Coat a Count-DPC) for FT4:FT4 (ECLIA) =
5.043+0.682 FT4 (RIA), (r = 0.770; Sy/x = 4.774) and RIA (Spectria-Orion
Diagnostica) for T3: T3(ECLIA) = -0.461+1.084 T3 (RIA), (r = 0.970; Sy/x =
0.412). When sera from 102 patients were processed by both methods, minimal
disagreement in the area of diagnostic classification was observed in 8/102
(7.8%) of the cases. CONCLUSION: The Elecsys 2010 is specially attractive as a
routine assay because it is fully automated, obtaining results in only 18
minutes. The analytical assay performance for TSH, FT4 and T3 was shown to be
acceptable. Using two different sets of diagnostic tests minimal discrepancies
were found in the laboratory assessment for the classification of patients with
clinical suspicion of thyroid disease.
PMID- 10667474
TI - Comparison of fatty acid profiles in the serum of patients with prostate cancer
and benign prostatic hyperplasia.
AB - OBJECTIVE: The role of dietary fatty acids (FAs) in benign and malignant
prostatic diseases was investigated by comparing the composition value of serum
fatty acids in the normal controls, and patients with prostate cancer (PC) and
benign prostatic hyperplasia (BPH). Also, to estimate a possible association
between PC risk and PUFAs, omega-3, omega-6 and omega-3/omega-6 FA composition
ratios were compared among these groups. METHODS: Serum samples were obtained
from 24 BPH and 19 PC patients, and from 21 age-matched normal male subjects. The
serum concentration of 21 fatty acids was determined using gas
chromatography/mass spectrometry. RESULT: The proportional values of saturated
fatty acids (SFAs) groups demonstrated no specific difference between the control
subjects and the patients. In the polyunsaturated fatty acids (PUFAs), we found
that the omega-3 PUFAs level was significantly decreased in patient with BPH and
PC and that the omega-6 PUFAs level was increased in PC only. The ratio of omega
3/omega-6 PUFAs decreased in the following order of normal, BPH, and PC.
CONCLUSION: It was proposed that the changed composition level of PUFAs including
omega-3 and omega-6 PUFAs have certain relationship with both prostatic diseases.
Therefore, the ratio of omega-3/omega-6 PUFAs also may have an important
association with the benign and malignant status of prostatic disease.
PMID- 10667475
TI - A splicing mutation in the hydroxymethylbilane synthase gene in a Japanese family
with acute intermittent porphyria.
AB - OBJECTIVES: Acute intermittent porphyria (AIP) is an autosomal dominant inherited
disease caused by a decreased activity of hydroxymethylbilane synthase (HMBS). As
far as the gene abnormalities of the HMBS, many different mutations have been
reported. In this work, we investigated the presence of mutations in a Japanese
family with AIP. DESIGN AND METHODS: A 44-year-old Japanese male and nine members
of his family were investigated. All of them were screened by traditional
biochemical markers. Mutational analysis was performed using polymerase chain
reaction-single strand conformation polymorphism method followed by DNA
sequencing. A reliable restriction enzyme cleavage assay was established for the
pedigree analysis. RESULTS: The mutation was a splicing mutation, a C to G
transversion at position -3 of the acceptor site of intron 11 of the HMBS gene,
resulting in the exon 12 skipping. The patient is heterozygous for the mutation,
and his father appeared to be the source of the mutant allele. This mutation
created a new cleavage site of the Nla III restriction enzyme and could be
screened by a amplified fragment from genomic DNA with digestion. Using this
cleavage assay, an asymptomatic carrier in the family was definitively
identified. CONCLUSIONS: This mutation was first found among Japanese AIP
patients, but happened to be the same as reported previously from Europe. A
similarity of gene abnormality may suggest that those European and Japanese AIP
families have a common ancestor. Molecular investigations on the family members
should be applied not only for more accurate diagnosis, but also for
understanding the molecular genetic heterogeneity underlying this dominantly
inherited enzymopathy.
PMID- 10667476
TI - The effect of gestational age, birth weight, and disease on troponin I and
creatine kinase MB in the first year of life.
AB - OBJECTIVES: To determine the effect of gestational age and birth weight (BW) on
troponin I (TnI) and creatine kinase MB fraction (CKMB) levels during the first
year of life. METHODS: Troponin I and CKMB levels were determined in infants less
than 1 year of age using the Immuno I (Bayer Corp.). RESULTS: Troponin I
fractions were greatest in the preterm infant; the levels decreased significantly
with increasing gestational age and BW, (p = 0.008 and p = 0.005, respectively).
The CKMB levels did not exhibit a significant difference between the preterm and
term infant groups when assessed for the effects of gestational age or BW (p =
0.12 vs. p = 0.35). Neither TnI nor CKMB levels were significantly different
between preterm survivors and nonsurvivors (p = 0.31; p = 0.34, respectively).
TnI levels were elevated in critically ill patients without documented myocardial
infarction, and without a comparable rise in CKMB. CONCLUSION: The higher TnI
levels during the first 3 months of life may indicate programmed cell death, or
apoptosis. This may be especially true in the preterm infant in which the
greatest values were documented.
PMID- 10667477
TI - Catalase and paraoxonase in hypertensive type 2 diabetes mellitus: correlation
with glycemic control.
AB - OBJECTIVES: Type 2 diabetes mellitus (DM) is well recognized as being associated
with increased prevalence of hypertension. Experimental and epidemiologic studies
have shown that oxygen-free radicals are elevated because antioxidant enzyme
activities are altered both in uncontrolled essential hypertension and DM itself.
Recently paraoxonase (PON) has been recognized as an antioxidant enzyme that
hydrolyzes lipid peroxides. The aim of this study is to evaluate simultaneously
PON activities and antioxidant status in hypertensive type 2 DM cases and to
establish any possible relationship between these parameters and duration of
hypertension or diabetes, hemoglobin (Hb) A1c levels, and lipid parameters.
DESIGN AND METHODS: Nineteen normotensive subjects with type 2 DM, 37
hypertensive (diastolic blood pressure 90 mm Hg or more) subjects with type 2 DM,
and 25 normotensive control subjects with normal glucose tolerance were selected
for this study. Superoxide dismutase (SOD), catalase, and basal-stimulated PON
activities were measured by the methods of Sun et al.; Goth; and Eckerson, Wyte,
and La Du, respectively; other lipid parameters were determined using an
autoanalyzer. RESULTS: Catalase activities of either hypertensive patients with
type 2 DM or type 2 DM patients without complication were found to be higher than
controls (p<0.01), although no significant difference in SOD and basal-stimulated
PON activities was observed between these groups. A significant elevation in
catalase activity (p = 0.004) of patients with high HbA1c levels (>7.0%) (n = 37)
compared with patients with low HbA1c levels (<7.0%) (n = 19) was detected. There
was also a positive correlation between the catalase activities and fasting
glucose levels and HbA1c concentrations in hypertensive patients with type 2 DM
(r = 0.4567, p<0.05 and r = 0.3686, p<0.05, respectively). An increase in
catalase activity of patients with B and/or AB phenotype compared with patients
with A phenotype was also noted. CONCLUSION: Poor glycemic control in diabetes is
strongly associated with an increase in free radicals and consequent diabetic
complications. Uncontrolled glucose metabolism may also be the cause of
alterations in antioxidant enzymes. Among these, catalase correlates best with
poor glycemic control. The current data reveal that B allele carriers of PON are
more susceptible to oxidant stress.
PMID- 10667478
TI - Lipoprotein-genotype associations in Trinidadian neonates.
AB - OBJECTIVES: We hypothesized that common variation in the angiotensinogen (AGT),
beta-3-adrenergic receptor, intestinal fatty acid-binding protein, serum
paraoxonase, paraoxonase-2, hepatic lipase, apolipoprotein E (APOE), and Werner
helicase (WRN) genes would be associated with variation in biochemical phenotypes
in a previously unstudied neonatal sample. DESIGN AND METHODS: We examined
associations of both nongenetic and genetic variables with plasma lipoprotein
traits in neonates from Trinidad. RESULTS: Among nongenetic variables, we found
significant associations between plasma concentrations of: 1) lipoprotein(a)
[Lp(a)] and both ethnicity (p = 0.037) and birth weight (p = 0.001); 2) total
cholesterol and gender (p = 0.010); 3) triglyceride and birth weight (p = 0.035);
and 4) apolipoprotein AI and gender (p = 0.016). Among genetic variables, we
found that: 1) common variation on chromosome 1q in AGT codon 235 was
significantly associated with variation in plasma apolipoproteins AI (p<0.0001)
and B (p = 0.013); 2) common variation in WRN at codon 1367 was significantly
associated with variation in plasma Lp(a) (p<0.0001); and 3) common variation in
APOE at codons 112 and 158 was significantly associated with variation in plasma
triglycerides (p = 0.013). CONCLUSIONS: The associations with AGT and WRN are
novel and may have resulted either from a direct influence of the genetic
variants or through linkage disequilibrium with other functional loci, such as
the familial combined hyperlipidemia locus on chromosome 1q in the case of AGT.
Despite the fact that there are some limitations in making determinations from
cord blood, the results suggest that there may be genetic determinants of plasma
lipoproteins in neonates.
PMID- 10667479
TI - Evaluation of some tissue and serum biomarkers in prostatic carcinoma among
Egyptian males.
AB - OBJECTIVES: The purpose of this study is to evaluate the role of soluble E
cadherin as a serum marker and bcl-2 and DNA content as tissue markers in
characterization and management of prostatic adenocarcinoma (PC) among Egyptian
males. DESIGN AND METHODS: The study group included 71 patients with prostatic
adenocarcinoma, 30 patients with benign prostatic hyperplasia (BPH), and 20
normal male subjects. Serum soluble E-cadherin (sE-cadherin) and PSA were
quantified by ELISA and MEIA (microparticle enzyme immunoassay) techniques,
respectively. Tissue samples were investigated for bcl-2 chromosomal
translocation t(14;18) by polymerase chain reaction (PCR) together with detection
of bcl-2 protein expression by immunohistochemistry. The results were correlated
with DNA content (as defined by flow cytometric analysis) and also with
traditional clinicopathologic parameters. RESULTS: Our data revealed that, serum
PSA was superior to sE-cadherin as a marker for PC with a sensitivity of 83%
compared to 59% in case of E-cadherin at the same specificity (96.6%).
Combination of both markers raised the sensitivity to 90%. E-cadherin correlated
with Gleason score. Ploidy status, synthetic phase fraction (SPF), and
proliferation index (PI) correlated significantly with tumor Gleason score. PI
was also correlated to clinical stage. bcl-2 protein was overexpressed in 14% of
PC and it showed a trend for correlation with tumor Gleason score (p = 0.06). We
failed to detect chromosomal t(14;18) in the bcl-2 gene in all the studied
tumors. CONCLUSIONS: E-Cadherin is a clinically useful biomarker in PC specially
in combination with PSA. DNA content changes and bcl-2 oncogene may account for
tumorogenesis and may assist in prognostication of PC.
PMID- 10667480
TI - Effect of eating on plasma radical-trapping antioxidant activity (TRAP) in
patients with cirrhosis.
AB - OBJECTIVES: To ascertain the effects of eating on plasma antioxidant capacity in
patients with liver disease. DESIGN AND METHODS: Eighteen cirrhotic patients were
compared to 18 age and sex-matched controls. TRAP was measured by a fluorometric
assay after a 12 h fast, and 60, 120, and 180 min after the study participants
had taken a drink formula food. RESULTS: In the fasting state, TRAP was higher in
patients with alcoholic cirrhosis (847+/-39 micromol/L, mean +/- SEM) in
comparison to patients with viral cirrhosis (653+/-41) and to controls (758+/-26)
(p<0.005). In cirrhotic patients, TRAP did not change in the post-absorptive
state. In controls, TRAP decreased progressively, to a value of 719+/-21
(p<0.02), and the AUC of the delta-values of TRAP and of plasma insulin showed an
inverse correlation (r = -0.52, p<0.05). CONCLUSIONS: In normal subjects, but not
in cirrhotics, TRAP decreases in the post-absorptive state, probably in
relationship with the activation of metabolic pathways.
PMID- 10667481
TI - RANTES and MCP-1 chemokine plasma levels in chronic renal transplant dysfunction
and chronic renal failure.
AB - OBJECTIVES: Procedures to diagnose renal allograft rejection depend on detection
of graft dysfunction due to the presence of mononuclear leukocytic infiltrates.
DESIGN AND METHODS: In our study, we pursued an immunodiagnostic approach
utilizing an ELISA method on plasma samples to monitor patients waiting to
undergo transplantation in order to evidence prognostic developments in renal
transplantation and, at least, to diagnose renal chronic transplant dysfunction.
We analyzed blood levels of two chemokines, RANTES and MCP-1, which are normally
overexpressed locally in renal chronic rejection. RESULTS: Our results showed
that patients affected by chronic renal failure (and waiting for kidney
transplant), as well as kidney-grafted patients affected by chronic transplant
dysfunction, had plasma levels of RANTES significantly higher than those of
controls (patients without acute or chronic pathologies). CONCLUSIONS: Our data
suggest a simple method to evaluate the plasmatic presence of RANTES, which could
be involved in longterm kidney graft failure.
PMID- 10667482
TI - Effects of pentoxifylline and coenzyme Q10 in hepatic ischemia/reperfusion
injury.
AB - OBJECTIVES: We examined whether pentoxifylline (PTX) and coenzyme Q10 (Q)
pretreatment affect ischemia-reperfusion damage in the rat liver. DESIGN AND
METHODS: Twenty minutes of reflow following 30 min of ischemia was performed.
Before the experiment, rats were treated PTX 50 mg/kg, IP or PTX 50 mg/kg IP +
Q10 mg/kg, intragastric, or untreated. Rats were divided into four groups:
control (C), ischemia-reperfusion (IR), PTX-treated (P), and Q+PTX-treated (QP)
groups. Hepatic glutathione (GSH) and malondialdehyde (MDA) levels and catalase,
superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and reductase
(GSSGR) activities were measured. RESULTS: In IR group GSH levels decreased
(p<0.01), conversely MDA levels increased (p<0.01). PTX pretreatment did not
affect GSH and MDA values, but Q+PTX pretreatment improved of those (p<0.01). It
was shown that catalase and GSH-Px activities increased during ischemia
reperfusion (p<0.01, both of), but PTX pretreatment did not significantly
ameliorate those activities. GSSGR activity was higher in IR group than in basal
levels (p<0.01). The decrease GSSGR activity that was observed in P group was not
significant compared to IR group. During ischemia/reperfusion also SOD activity
increased as compared with controls (p<0.05). In PTX-treated group, SOD activity
was significantly higher than control and ischemia/reperfusion groups (p<0.01,
both of). Q+PTX treatment ameliorated those enzyme activities to the control
values. CONCLUSIONS: Short-term hepatic ischemia-reperfusion diminished GSH,
increased MDA levels and induced some antioxidant enzyme activities. Q+PTX
pretreatment was useful in hepatic ischemia-reperfusion injury, but treatment of
PTX alone did not cause beneficial effect in the present study.
PMID- 10667483
TI - Tumor markers in lung cancer: does the method of obtaining the cut-off point and
reference population influence diagnostic yield?
AB - OBJECTIVES: The aim of this study was to evaluate the clinical usefulness of the
tumor markers CA125, CEA, NSE, SCC, and TPS in a group of patients with lung
cancer. We estimated the influence of the method for choosing the cut-off point
and of considering as a reference population either healthy controls or patients
with some form of non-neoplastic pulmonary disease (NNPD). DESIGN AND METHODS:
The tumor markers were determined using enzyme immunoassay techniques, and their
diagnostic yield was evaluated using ROC curves and their correlation with the
percentages between false and true positives. The diagnostic parameters of the
tumor markers are presented in 116 patients with lung cancer and compared with a
group of 25 healthy controls and another group of 80 patients with some form of
NNPD. We determined on the one hand the cut-off points resulting from the best
sensitivity-specificity balance in the ROC curves and on the other those
resulting from considering a specificity of 95%. With the two cut-offs we studied
the different diagnostic parameters: sensitivity, specificity and accuracy or
area below the ROC curve. RESULTS: Optimum diagnostic yield is obtained when we
choose the cut-off point determined by the best balance of sensitivity and
specificity in the ROC curves and take a healthy population as a reference group.
The cut-off values for CA125, CEA, NSE, SCC, and TPS were 24 U/mL, 2.8 ng/mL, 9.8
ng/mL, 1.6 ng/mL, and 67.8 U/L, respectively. CONCLUSIONS: Our results suggest
that in future studies on tumor markers, a group of healthy subjects should be
used as a reference population and ROC curves should be used to obtain the
optimum cut-offs.
PMID- 10667484
TI - Simultaneous detection of vitamin C and uric acid by capillary electrophoresis in
plasma of diabetes and in aqueous humor in acute anterior uveitis.
PMID- 10667485
TI - High percentage of false positive cardiac troponin I results in patients with
rheumatoid factor.
PMID- 10667486
TI - Fluorescent automated single-stranded conformation (F-SSCP) analysis is able to
detect a point mutation at the extreme 5' end of a PCR product.
PMID- 10667487
TI - Are expert systems "more intelligent" than laboratory doctors?
PMID- 10667488
TI - Evaluation of the Tosoh HLC-723GHb V A1c 2.2 hemoglobin A1c analyzer.
PMID- 10667489
TI - Extracellular calcineurin: identification and quantitation in serum and amniotic
fluid.
PMID- 10667490
TI - Serum apolipoprotein AI, B, and lipoprotein (a) levels in hypercholesterolemic
schoolchildren.
PMID- 10667491
TI - Modulation of neutrophil apoptosis by granulocyte colony-stimulating factor and
granulocyte/macrophage colony-stimulating factor during the course of acute
respiratory distress syndrome.
AB - OBJECTIVE: To determine whether bronchoalveolar lavage fluid (BALF) from patients
either at risk for the acute respiratory distress syndrome (ARDS) or with
sustained ARDS modulates neutrophil apoptosis; to measure the BALF concentrations
of the apoptosis inhibitors granulocyte colony-stimulating factor (G-CSF) and
granulocyte/macrophage colony-stimulating factor (GM-CSF) before and after the
onset of ARDS; and to determine whether the BALF concentrations of G-CSF and/or
GM-CSF are associated with clinical outcome. DESIGN: Prospective cohort study.
SETTING: Tertiary university hospital. PATIENTS: Twenty patients at risk for ARDS
and 45 patients with established ARDS. INTERVENTIONS: Patients at risk for ARDS
underwent bronchoalveolar lavage within 24 hrs of being identified, then again 72
hrs later. Patients with ARDS underwent bronchoalveolar lavage within 24 hrs of
meeting ARDS criteria, then again on days 3, 7, and 14 of the disease.
MEASUREMENTS AND MAIN RESULTS: Normal peripheral blood neutrophil were incubated
overnight in BALF from normal volunteers, from patients at risk for ARDS, or from
patients with ARDS. neutrophil apoptosis was determined by flow cytometric
analysis of annexin V binding. G-CSF and GM-CSF were measured in BALF by
immunoassays. Compared with normal BALF, BALF from patients on days 1 and 3 of
ARDS inhibited neutrophil apoptosis, but BALF from patients at later stages of
ARDS, or from patients at risk for ARDS, did not. The BALF concentrations of both
G-CSF and GM-CSF were elevated early in ARDS and decreased toward later stages.
Patients who lived had significantly higher concentrations of GM-CSF in the BALF
than those who died. CONCLUSIONS: We conclude that the antiapoptotic effect of
ARDS BALF on normal neutrophil is highest during early ARDS, and decreases during
late ARDS. G-CSF and GM-CSF are present in BALF from patients with ARDS, and
their concentrations parallel the antiapoptotic effect of ARDS BALF. These data
support the concept that the life-span of neutrophil in the air spaces is
modulated during acute inflammation. GM-CSF in the air spaces is associated with
improved survival in patients with ARDS.
PMID- 10667492
TI - Prevention of infection in multiple trauma patients by high-dose intravenous
immunoglobulins.
AB - OBJECTIVE: To investigate the activity of intravenous immunoglobulin (IVIG) as a
prophylactic agent against infection in trauma victims. DESIGN: Prospective,
randomized, double-blind, placebo-controlled study. SETTING: A 20-bed university
intensive care unit. PATIENTS: Thirty-nine trauma patients with injury severity
scores (ISSs) of 16-50. INTERVENTIONS: Penicillin was given at the time of
admission and continued at least until day 4. Twenty-one patients received IVIG
and 18 patients received human albumin at 1 g/kg in four divided doses (days 1,
2, 3, and 6). The two groups had similarities in age, gender, Acute Physiology
and Chronic Health Evaluation II score, risk of death, and Glasgow Coma Scale
score, but differing ISSs (p = .02), at the time of admission. Blood was
collected on days 1, 4, and 7. MEASUREMENTS AND MAIN RESULTS: Clinical variables
related to infection were recorded. The complement components C3c, C4 and CH50,
IgG, and the fractions of IgG were measured. The serum bactericidal activity
(SBA) was assessed at 37 degrees C (98.6 degrees F) and 40 degrees C (104.0
degrees F) at the time of admission and during the course of IVIG administration.
Controlling for ISS, IVIG-treated patients had fewer pneumonias (p = .003) and
total non-catheter-related infections (p = .04). Catheter-related infections (p =
.76), length of stay in the intensive care unit, antibiotic days, and infection
related mortality did not differ between the two groups. A significantly
increased trend in IgG and its subclasses was shown on days 4 and 7 in the IVIG
group but not in the control group (p<.000001). No important differences were
noted in complement fractions. The SBA of the groups was similar on day 1, but
significantly higher on days 4 and 7 (p<.000001) in the IVIG group, remaining so
controlling for complement and ISS. SBA was higher at 40 degrees C (104.0 degrees
F) compared with 37 degrees C (98.6 degrees F) (p<.0001) under all three
conditions. In both groups, low SBA (on days 1, 4, and 7) was associated with
increased risk of pneumonia (p<.01) and non-catheter-related infections (p = .06
for day 1; p<.01 for days 4 and 7). CONCLUSIONS: Trauma patients receiving high
doses of IVIG exhibit a reduction of septic complications and an improvement of
SBA. Early SBA measurement may represent an index of susceptibility to infection.
PMID- 10667493
TI - Changes in the management of severe traumatic brain injury: 1991-1997.
AB - OBJECTIVE: To survey the management of head-injured patients in 1997 and to
identify differences compared with a survey conducted in 1991. DESIGN: A two-page
questionnaire was mailed to all neurosurgeons in North America certified by the
American Board of Neurologic Surgeons, asking their views regarding the most
appropriate acute care of patients with severe traumatic brain injury (TBI).
SETTING: North American neurosurgical practices. PATIENTS: Not applicable.
INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Compared with a 1991 survey,
there was a significant increase in the proportion of neurosurgeons who felt
these patients should have intracranial pressure monitoring (28% vs. 83%) and a
decrease in the proportion who used prophylactic hyperventilation therapy (83%
vs. 36%) and steroids (64% vs. 19%). Ninety-seven percent of respondents felt
that the cerebral perfusion pressure should be maintained at >70 mm Hg, and 44%
indicated that patients with severe TBI should be treated at Level I trauma
centers. CONCLUSIONS: There have been significant changes in the acute management
of patients with severe TBI since 1991. Current practices more closely reflect
the recommendations of evidence-based guidelines.
PMID- 10667494
TI - Survivors of catastrophic illness: outcome after direct transfer from intensive
care to extended care facilities.
AB - OBJECTIVE: To describe outcomes of adult survivors of prolonged critical illness
after direct transfer to extended care facilities. DESIGN: A retrospective cohort
study. SETTING: All adult intensive care units (ICUs) in a tertiary care
university hospital. PATIENTS: A consecutive series of 97 adult survivors with an
ICU stay of > or =7 days transferred directly from intensive care to extended
care facilities between 1990 and 1996. INTERVENTIONS: None. METHODS AND MAIN
RESULTS: Hospital and extended care facility charts were reviewed for patient
characteristics, resource utilization, and survival. Survivors were for a minimum
of 1 yr and a maximum of 6 yrs, and were interviewed to assess quality of life
and functionality. The mean age of the patients was 66+/-16 (range, 19-93) yrs.
The median length of ICU stay for these patients was 39 (range, 7-276) days. Only
18 of the 71 ventilator-assisted patients were weaned from mechanical ventilation
after transfer to the extended care facility. Survival for the study period, at 1
yr after discharge from the ICU, was 49.5%. One year after discharge from the
ICU, 11.5% of all patients had returned home, were breathing spontaneously, had a
fair or better quality of life, and had good physical functionality. Each
successive year, an increasing proportion of patients underwent direct transfer
to an extended care facility. This strategy decreased the patients' length of
stay (p<.002) in the ICU from year to year, but was significantly associated with
an increase in readmissions to acute care hospitals (p<.002). CONCLUSIONS:
Survivors of catastrophic illness who are so debilitated that they require
transfer to an extended care facility have a low likelihood of achieving both
survival and functional independence 1 yr after discharge from the ICU.
Aggressive cost-conscious strategies to accelerate the transfer of these patients
successfully reduced the length of ICU stay and hospital costs, but were
associated with a high rate of readmission to tertiary care facilities.
PMID- 10667495
TI - Comparison of acute physiology and chronic health evaluations II and III and
simplified acute physiology score II: a prospective cohort study evaluating these
methods to predict outcome in a German interdisciplinary intensive care unit.
AB - OBJECTIVE: To evaluate the ability of three scoring systems to predict hospital
mortality in adult patients of an interdisciplinary intensive care unit in
Germany. DESIGN: A prospective cohort study. SETTING: A mixed medical and
surgical intensive care unit at a teaching hospital in Germany. PATIENTS: From a
total of 3,108 patients, 2,795 patients (89.9%) for Acute Physiology and Chronic
Health Evaluation (APACHE) II and 2,661 patients (85.6%) for APACHE III and
Simplified Acute Physiology Score (SAPS) II could be enrolled to the study
because of defined exclusion criteria. INTERVENTIONS: None. MEASUREMENTS AND MAIN
RESULTS: Probabilities of hospital death for patients were estimated by applying
APACHE II and III and SAPS II and compared with observed outcomes. The overall
goodness-of-fit of the three models was assessed. Hospital death rates were
equivalent to those predicted by APACHE II but higher than those predicted by
APACHE III and SAPS II. Calibration was good for APACHE II. For the other
systems, it was insufficient, but better for SAPS II than for APACHE III. The
overall correct classification rate, applying a decision criterion of 50%, was
84% for APACHE II and 85% for APACHE III and SAPS II. The areas under the
receiver operating characteristic curve were 0.832 for APACHE II and 0.846 for
APACHE III and SAPS II. Risk estimates for surgical and medical admissions
differed between the three systems. For all systems, risk predictions for
diagnostic categories did not fit uniformly across the spectrum of disease
categories. CONCLUSIONS: Our data more closely resemble those of the APACHE II
database, demonstrating a higher degree of overall goodness-of-fit of APACHE II
than APACHE III and SAPS II. Although discrimination was slightly better for the
two new systems, calibration was good with a close fit for APACHE II only.
Hospital mortality was higher than predicted for both new models but was
underestimated to a greater degree by APACHE III. Both score systems demonstrated
a considerable variation across the spectrum of diagnostic categories, which also
differed between the two models.
PMID- 10667496
TI - Acute quadriplegia and loss of muscle myosin in patients treated with
nondepolarizing neuromuscular blocking agents and corticosteroids: mechanisms at
the cellular and molecular levels.
AB - OBJECTIVE: Long-term treatment with nondepolarizing neuromuscular blocking agents
and corticosteroids in the intensive care unit is not benign, and an increasing
number of patients with acute quadriplegic myopathy have been reported with
increased use of these drugs. The purpose of this study was to investigate the
mechanisms underlying acute quadriplegic myopathy. DESIGN: Percutaneous muscle
biopsy samples were obtained, and electrophysiologic examinations were performed
during the acute phase and during recovery in patients with acute quadriplegic
myopathy. Regulation of muscle contraction and myofibrillar protein synthesis was
studied using cell physiologic techniques, ultrasensitive electrophoresis, in
situ hybridization, and histopathologic techniques. SETTING: All patients were
seen in the intensive care unit of different university hospitals. PATIENTS: All
patients were critically ill with sepsis. They had been given massive doses of
corticosteroids in combination with variable doses of neuromuscular blocking
agents. All patients developed paralysis of spinal nerve-innervated muscles. On
the other hand, cranial nerve-innervated muscle and sensory and cognitive
functions were well maintained after discontinuation of treatment with
neuromuscular blocking agents. INTERVENTION: Muscle biopsy samples were obtained
and electrophysiologic examinations were performed in all patients. MEASUREMENTS
AND MAIN RESULTS: The major observations in patients with acute quadriplegic
myopathy were, as follows: a) a general decrease in myofibrillar protein content;
b) specific but highly variable partial or complete loss of myosin and myosin
associated proteins; c) very low thick-filament/thin-filament protein ratios; d)
absence of myosin messenger RNA; and e) a dramatically impaired muscle cell force
generating capacity in the acute phase of acute quadriplegic myopathy. During
clinical improvement, normal expression of myosin messenger RNAs, reexpression of
thick-filament proteins, and increased specific tension were observed.
CONCLUSIONS: Acute quadriplegic myopathy is associated with a specific decrease
in thick-filament proteins related to an altered transcription rate. Although the
decreased content of thick-filament proteins is important for prolonged muscle
weakness, it is not the primary cause of muscle paralysis in the acute stage,
during which impaired muscle membrane excitability probably plays a more
significant role. Several factors contribute to this condition, but the action of
corticosteroids seems to be the predominant one, along with potentiation by
neuromuscular blocking agents, immobilization, and probably also concurrent
sepsis.
PMID- 10667497
TI - Characterization of gastrointestinal bleeding in severely ill hospitalized
patients.
AB - OBJECTIVE: To characterize the source of bleeding and the prognosis in critically
ill patients with upper gastrointestinal hemorrhage that developed while in the
hospital. SETTING: Intensive care units of a large academic tertiary-care center.
DESIGN: Retrospective cohort study. SUBJECTS: Patients undergoing endoscopy in
intensive care units for gastrointestinal bleeding that developed while in the
hospital. MEASUREMENTS AND MAIN RESULTS: Medical records were available for 142
patients. Of these, 66 met the criteria for in-hospital bleeding. Peptic ulcer
disease, present in 56% of patients, was the most common bleeding source
identified. Of patients with peptic ulcer disease, nine of 37 (24%) had stigmata
of recent hemorrhage. Ten patients (15%) received endoscopic hemostasis
interventions (eight receiving therapy for bleeding ulcers, two receiving therapy
for esophageal varices). The in-hospital mortality rate was 42%. The cause of
death was sepsis and/or multiple system organ failure in 21 patients (75%); the
gastrointestinal bleeding may have contributed to the onset of sepsis in one of
these patients. No patients died directly of gastrointestinal bleeding.
CONCLUSIONS: Critically ill patients who bleed while in the hospital have similar
sources of bleeding and rates of endoscopically directed therapy as patients
admitted to hospital with bleeding. The mortality rate is very high in patients
with bleeding that develops in the hospital, and this is usually a result of
systemic disease. These data may help clinicians and patients to estimate the
potential benefit of urgent endoscopy in critically ill patients.
PMID- 10667498
TI - Thermodilution versus inert gas rebreathing for estimation of effective pulmonary
blood flow.
AB - OBJECTIVE: To compare measurements of the effective pulmonary blood flow (Qep,
i.e., nonshunted fraction of cardiac output, Qt) by the inert gas rebreathing
(RB) method and the thermodilution (TD) technique in critically ill patients.
DESIGN: Prospective, comparative study of a noninvasive method and an established
invasive technique. SETTING: An 11-bed general intensive care unit in a
university hospital. PATIENTS: A total of 14 critically ill patients, all
mechanically ventilated and monitored with systemic and pulmonary artery
catheters. MEASUREMENTS AND MAIN RESULTS: Qep was determined in duplicate by RB
using a mass spectrometer for gas analysis. For each determination, Qt was
measured in triplicate by the cold water bolus TD technique and averaged.
Simultaneously mixed venous and arterial blood samples were analyzed to calculate
the intrapulmonary shunt fraction and thereby convert estimates of Qt to Qep.
Mean difference between paired estimates (RB - TD) was 0.01 L/min, so for
differences was 1.19 L/min, and 95% confidence interval for the bias was -0.45 to
0.47 L/min. Coefficients of variation for repeated Qep estimates were 8% (RB) and
12% (TD), respectively. Coefficients of variation for RB estimates of functional
residual capacity and lung tissue volume were 6% and 17%, respectively.
CONCLUSIONS: The RB method is a promising method for simultaneous noninvasive
estimation of Qep and functional residual capacity in mechanically ventilated
patients. However, further investigations are needed to evaluate potential
problems of the method before it can be recommended for clinical purposes.
PMID- 10667499
TI - Evolution of leukotriene B4, peptide leukotrienes, and interleukin-8 plasma
concentrations in patients at risk of acute respiratory distress syndrome and
with acute respiratory distress syndrome: mortality prognostic study.
AB - OBJECTIVE: To compare the evolution of plasma concentrations of leukotriene (LT)
B4, LTC4, LTD4, and interleukin (IL)-8 in patients with acute respiratory
distress syndrome (ARDS) and in patients at risk of ARDS and to assess the value
of these mediators in predicting mortality rate from ARDS. DESIGN: A case-control
study comparing ARDS patients and patients at risk of ARDS as well as survivors
and nonsurvivors with ARDS. SETTING: Hospital intensive care unit, laboratory,
and department of hematology. PATIENTS: Twenty-one patients with ARDS and 14
patients at risk of ARDS. INTERVENTION: Arterial blood samples were collected on
days 0, 1, and 5 after admission to the intensive care unit. MEASUREMENTS AND
MAIN RESULTS: LTs were extracted, separated by high-pressure liquid
chromatography and quantified by enzyme immunoassay. IL-8 was analyzed by ELISA.
Plasma concentrations of LTB4 and LTC4 plus LTD4 were significantly higher in
ARDS patients than in patients at risk of ARDS during the first 24 hrs.
Concentrations of IL-8 were also higher in ARDS patients than in patients at risk
throughout the study, although the differences between the two groups were only
significant on day 5. Only the plasma concentration of LTB4 on day 1 was a marker
of ARDS (72.2% sensitivity, 84.6% specificity). A logistic regression analysis
showed that LTB4 and IL-8, on day 1, were markers of mortality rate in patients
with ARDS (70.0% sensitivity, 87.5% specificity). CONCLUSIONS: LTs are elevated
during the early phases of ARDS, whereas IL-8 increases throughout the study. The
evaluation of LTB4 and IL-8 may be useful prognostic indices in patients with
early phase ARDS after admission to the intensive care unit.
PMID- 10667500
TI - Accidental removal of endotracheal and nasogastric tubes and intravascular
catheters.
AB - OBJECTIVES: To characterize the rates of accidental removal of endotracheal
tubes, nasogastric tubes, central venous catheters, and arterial catheters. To
assess the efficacy of corrective measures aimed at reducing the accidental
removal of these devices. DESIGN: Prospective, observational, and interventional
study. SETTING: Eighteen-bed medical-surgical intensive care unit of a 650-bed
tertiary care hospital. PATIENTS: Patients admitted to the intensive care unit
who had any of the following devices in place for more than 24 hrs: endotracheal
tube, nasogastric tube, central venous catheter, arterial catheter. MEASUREMENTS
AND INTERVENTIONS: Data were collected on the date of placement of tubes and
catheters, position of vascular catheters, date of removal, and reason for
removal. The study involved three consecutive 6-month periods. At the end of the
first and the second periods, information about rates of accidental removal was
provided to the physicians and nurses. In addition, the personnel were instructed
to be more vigilant and specific measures aimed at reducing the accidental
removal were introduced. MAIN RESULTS: In the first period, 289 endotracheal
tubes were placed and 13.1% (24.7 per 1000 days) were removed accidentally. In
the second and third periods, 17.1% (25.5 per 1000 days) and 11.4% (15.1 per 1000
days) were removed accidentally, respectively. In the first period, 368
nasogastric tubes were placed and 41% (73.9 per 1000 days) were removed
accidentally. In both the second and the third period, a significant reduction in
the rate of accidental removal was observed (32.4% or 41.2 per 1000 days and
25.8% or 29.8 per 1000 days, respectively). A significant decrease was observed
in the rates of accidental removal of central venous catheters from 7.5% (12.4
per 1000 days) in the first period to 3.6% (5.4 per 1000 days) in the second
period. The rate of arterial catheters accidentally removed expressed according
to the time at risk significantly decreased from 46.5 per 1000 days in the first
period to 19.1 per 1000 days in the second period and 25.3 per 1000 days in the
third period. CONCLUSIONS: The information provided by the rates of accidental
removal expressed by patient-days is helpful to compare results obtained in
populations with different times of follow-up. Education of medical personnel and
limiting upper-extremity access to within 20 cm from any catheter or tube
resulted in a significant reduction of patient-related removal of tubes and
catheters.
PMID- 10667501
TI - Bacterial contamination of ready-to-use 1-L feeding bottles and administration
sets in severely compromised intensive care patients.
AB - OBJECTIVE: In intensive care patients, enteral feeding requires sterile feedings
because of infectious complications and adequate supplements to meet nutritional
needs. Heretofore, prepacked, large-volume formula containers were developed, but
bacterial contamination occurred in 4% to 15%. Our objective was to investigate
the microbial contamination rate of 1-L feeding bottles and newly designed
administration sets over hanging times of 24 hrs in the intensive care unit
(ICU). DESIGN AND SETTING: A prospective observational cohort study of patients
admitted to the ICU of a university hospital. PATIENTS: All consecutive patients
fed via a nasojejunal tube for at least 4 days. MEASUREMENTS: Cultures of feeding
bottles, administration sets, and gastric and tracheobronchial aspirates at day
0, 1, 2, 4, and 7. RESULTS: A total of 4% of feeding bottles and 74% of infusion
sets contained >10(2) colony forming units (CFU)/mL. Gastric and bronchial
aspirates were positive in 90% and 92%, respectively. Bacterial counts of feeding
bottles were 10(2)-10(5) CFU/mL, and the main bacteria isolated included
Enterobacter cloacae, Klebsiella oxytoca, and enterococci. One third of all
cultured bacteria in feeding bottles, administration sets, stomach, and lungs
belonged to the Enterobacteriaceae family, which was held responsible for the
nosocomial infections in the ICU. None of the 1-L feeding bottles with a hanging
time of 19-24 hrs was contaminated. Only bottles that had to be exchanged because
of need for a faster rate of infusion proved to be contaminated, apparently
without clinical consequences. With time and the increasing severity of disease,
the administration sets became contaminated at an increasingly faster rate and
with higher bacterial counts mainly through retrograde growth of endogenous
bacteria. The final step of bottle contamination might have been the bacterial
transfer by nurses' hands. CONCLUSION: Despite an almost ideal design of the
enteral nutrition delivery system, a 4% contamination rate of initially sterile
feedings with clinically relevant bacteria and the fact that only manipulated
systems showed bacterial growth are of concern.
PMID- 10667502
TI - Human neutrophil activation and increased adhesion by various resuscitation
fluids.
AB - OBJECTIVE: To determine whether activated neutrophils play a major role in
secondary tissue injury after resuscitation in trauma. We hypothesized that human
neutrophil activation and adhesion vary, depending on the type and amount of
resuscitation fluid used. SETTING: University-based research facility. SUBJECTS:
Ten healthy adult volunteers. DESIGN: Whole blood from volunteers was serially
diluted in polypropylene tubes with various resuscitation fluids. Fluids tested
were phosphate-buffered saline, normal saline, lactated Ringer's solution,
dextran, hespan, 5% human albumin, 25% human albumin, 3.5% hypertonic saline, and
7.5% hypertonic saline. Neutrophil activation (intracellular oxidative burst
activity with dichlorofluorescin diacetate staining) and adhesion (integrin cell
surface expression of CD18) were measured with flow cytometry (fluorescence
activated cell sorting). Blood was diluted with hypertonic saline by controlling
for sodium content equal to normal saline. dose-related increase in neutrophil
oxidative burst activity as the result of dilution followed with crystalloid
fluids and artificial colloids (dextran and hespan). The increase was 12-18 x
baseline at the 75% dilution. The increase with 5% human albumin was only 2.2 x
baseline, and 25% albumin did not demonstrate any increased intracellular
activity. A similar significant increase in the neutrophil adhesion expression
(CD18) occurred with artificial colloids (p<.05) and, to a lesser extent, with
crystalloids, but not with albumin. Hypertonic saline caused a decrease in CD18
cell surface expression. CONCLUSIONS: This study suggests that the neutrophil
activation and adhesion may vary, depending on the type of resuscitative fluid
used. All artificial resuscitative fluids may not be similar or innocuous, as
demonstrated by the dose-related increase in neutrophil activation and adhesion.
PMID- 10667503
TI - Interhospital transport of the extremely ill patient: the mobile intensive care
unit.
AB - BACKGROUND: Critically ill patients may require specialized care that is offered
only at tertiary referral centers. As regionalization and specialization of
critical care become more common, transportation of critically ill patients must
be refined. Transportation of critically ill patients within a hospital, much
less outside the hospital, is often deemed unsafe because of medical instability.
We report, here, our results from 2 yrs' experience of transporting extremely ill
patients with respiratory failure via a ground critical care transport service.
METHODS: A mobile intensive care unit was equipped and staffed to nearly recreate
the intensive care environment. Staffing included a physician, nurse, respiratory
therapist, and driver--all with extensive critical care experience. The mobile
intensive care unit was equipped with a full pharmacy, advanced ventilatory
equipment, and capability for full invasive hemodynamic monitoring. Data were
analyzed by retrospective review. The predicted mortality rate, based on
Pao2/Fio2 ratios, was compared with the actual mortality rate. RESULTS: During a
2-yr period, 39 critically ill patients were transported. Thirty-six of the 39
were candidates for extracorporeal lung assist, with a mean positive end
expiratory pressure requirement of 15.9, a mean Fio2 requirement of .93, and a
mean Pao2/Fio2 ratio of 59.8. Pulmonary arterial catheters and peripheral
arterial catheters were in place in 66.6% and 72% of patients, respectively.
Vasoactive medications were being infused in 56%, and 74% were receiving medical
paralytics. One patient died during movement from the bed to the transport
gurney. Other than one episode of transient hypotension, there were no
complications or untoward outcomes related to transport. Unique therapeutic
interventions were performed at the receiving facility on 34 of 39 patients. The
predicted mortality rate, based on indicators of lung dysfunction, was 68% to
100%; the actual subsequent hospital mortality rate was 43%. CONCLUSIONS: When a
mobile intensive care unit is properly staffed and equipped and patient
stabilization is performed before transfer, severely ill patients with
respiratory failure can be transferred safely. For patients with respiratory
failure, there may be a survival advantage in transfer to regional centers of
expertise.
PMID- 10667504
TI - Early psychological reactions to life-threatening injuries.
AB - OBJECTIVE: To assess the prevalence of posttraumatic stress symptoms and coping
patterns in severely injured accident victims; to study correlations between
injury severity and psychosocial variables and the presence of posttraumatic
stress symptoms; and to analyze intensive care unit (ICU) personnel's global
clinical appraisals in relation to patient characteristics. DESIGN: A study of
critically ill accident victims assessed within one month of the trauma. SETTING:
ICU of the traumatology department at the University Hospital, Zurich. PATIENTS:
121 consecutive patients with accidental injuries (mean Injury Severity Score,
21.8; mean Glasgow Coma Scale score, 14.4) admitted to the ICU between January
1996 and June 1997, aged 18-68 yrs. Patients with severe head injuries, attempted
suicides, and victims of physical assault were excluded. MEASUREMENTS: Extensive
clinical interview, Impact of Event Scale, Clinician-Administered Posttraumatic
Stress Disorder Scale, social support, life events, biographical protective and
risk factors, Sense of Coherence questionnaire, Freiburg Questionnaire of Coping
with Illness. RESULTS: 13.7 (SD, 6.8) days after the accident, 5 patients (4.1 %)
met all criteria for posttraumatic stress disorder with the exception of the time
criterion. A further 24 patients (19.9%) had subsyndromal posttraumatic stress
disorder. Posttraumatic psychiatric symptomatology did not correlate with
objective injury criteria, but rather with pretrauma variables (female gender,
biographical risk and protective factors, life events), the patients' subjective
appraisal of the severity and threat of the accident, their general attitude
toward life ("sense of coherence"), and their current coping strategies.
Surgeons' and nurses' global clinical appraisals did not correlate with injury
severity or with the patients' coping strategies. CONCLUSIONS: Trauma surgeons
and ICU personnel should pay special attention to the strains and stressors their
patients have been exposed to when recording case histories and to the level of
their patients' psychosocial adaptation before the trauma.
PMID- 10667505
TI - Hypocalcemia and parathyroid hormone secretion in critically ill patients.
AB - OBJECTIVE: To investigate possible causes of hypocalcemia and to assess
parathyroid hormone (PTH) secretion in intensive care unit (ICU) patients.
DESIGN: Combined cross-sectional and prospective study. SETTING: ICU in a
university hospital. PATIENTS: Thirteen patients with sepsis and 13 patients who
underwent major surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS:
Calcium metabolic indices were investigated during the first 24 hrs in the ICU
and after 2 days. Eight of the surgical patients and five of the septic patients
were subjected to a citrate/calcium infusion on day 1 in the ICU, to study the
dynamics of PTH secretion. The blood ionized calcium (Ca2+) concentration was
generally low in the septic patients (mean +/- SD, 1.03+/-0.08 mmol/L; reference
value, 1.10-1.30) and increased, but not normalized, after 2 days. Hypocalcemia
was only occasionally seen in the surgical patients. In the septic patients,
urinary excretion of calcium was low; and, in both patient groups, elevated
concentrations of two markers of bone resorption, deoxypyridinoline and ICTP
(serum carboxy-terminal cross-linked telopeptide of type I collagen), were found.
In cases of sepsis, the concentrations of proinflammatory cytokines were high
(394+/-536 pg/mL for tumor necrosis factor-alpha and 5676+/-5190 pg/mL for
interleukin-6, both normally <10-20). The Ca2+ concentration was inversely
related to tumor necrosis factor-alpha and interleukin-6 (r2 = .35-.42; p<.01),
as well as to procalcitonin (r2 = .71; p<.01). Despite normocalcemia in the
surgical patients, serum PTH concentrations were elevated in both patient groups
(97 and 109 ng/L) (reference value, <55 ng/L), both on day 1 and day 3 in the
ICU. The citrate/calcium infusion revealed an increased secretory response of PTH
to lowered Ca2+ concentrations in both groups of patients (p<.05), when compared
with matched healthy controls. CONCLUSION: Hypocalcemia was common in septic ICU
patients and was not the result of an increased urinary excretion of calcium or
of an attenuated bone resorption, but seemed related to the inflammatory
response. An increased PTH secretion was found in both patient groups.
PMID- 10667506
TI - Death in two Canadian intensive care units: institutional difference and changes
over time.
AB - OBJECTIVE: To study and compare the mode of death in two different institutions'
intensive care units (ICUs) for the two time periods, 1988 and 1993. DESIGN:
Retrospective chart review. SETTING: Medical/surgical/trauma ICUs in two tertiary
care teaching hospitals. PATIENTS: Patients dying in the medical/surgical/trauma
ICUs between January 1, 1988 and December 31, 1988; and January 1, 1993 and
December 31, 1993. Data collection included demographics, origin of admission,
date of ICU admission, date of death, Acute Physiology and Chronic Health
Evaluation (APACHE) III diagnostic categories, APACHE II physiologic variables,
organ system failures present at the time of admission and 24 hrs before death,
and mode of dying. APACHE II scores and mortality risk were calculated. Data
analysis included a multiple analysis of variance to assess overall effect, with
subsequent analyses of variance to assess the effect of institution and year on
each individual dependent variable. All results are reported as mean +/- SEM
values. RESULTS: A total of 439 charts were reviewed. Gender, age, and origin of
admission were not different between the 2 yrs or the two institutions. Mean
APACHE II scores and organ system failures were lower at Hospital A in 1998 vs.
Hospital B, as was predicted mortality. These factors increased at Hospital A in
1993 and were similar to those at Hospital B. Withdrawal of support was much more
common in 1993 than 1988 at both institutions (43% at Hospital A and 46% at
Hospital B in 1988 vs. 66% at A and 80% at B in 1993), increasing to a greater
extent in 1993 at Hospital B (p<.05). Length of stay in the ICU was significantly
longer at Hospital A than at Hospital B in 1988 (9.4+/-1.4 vs. 4.3+/-0.6 days;
p<.05) and in 1993 (8.2+/-2.9 vs. 3.8+/-0.5 days; p < .05). CONCLUSIONS: There
has been an increase in withdrawal of life support, in recent years, at both the
institutions studied. Differences exist between institutions with respect to end
of-life decisions in the ICU. These differences are likely representative of
widely prevalent regional differences and are the result of many factors.
PMID- 10667507
TI - Lipopolysaccharide binding protein in acute pancreatitis.
AB - OBJECTIVE: To assess the expression of plasma lipopolysaccharide binding protein
(LBP) concentrations and its relationship to markers of the systemic inflammatory
response syndrome during acute pancreatitis. DESIGN: A prospective study.
SETTING: General surgical units of university teaching hospitals in the Belfast
area. PATIENTS: The study included 18 patients admitted with established
diagnosis of acute pancreatitis on the basis of elevated serum amylase or by
contrast radiology. Patients were retrospectively stratified using the Modified
Glasgow Criteria into severe (n = 7) and mild (n = 11) disease. INTERVENTIONS AND
MEASUREMENTS: Blood samples were obtained at admission (day 1) and for a further
3 days for the measurement of LBP, C-reactive protein (CRP), tumor necrosis
factor, and interleukin (IL)-6. Acute Physiology and Chronic Health Evaluation
(APACHE) II scores were calculated on day 1 and day 2. MAIN RESULTS: LBP and CRP
concentrations were significantly increased from healthy control values in acute
pancreatitis patients at presentation. In the mild group LBP, CRP and IL-6
concentrations remained relatively constant throughout the study period. By
comparison, severe acute pancreatitis was associated with significantly higher
LBP concentrations and a marked systemic inflammatory response as evidenced by
increased CRP, IL-6, and APACHE II scores. The rise in LBP occurred after the
observed increase of these markers. Significant correlations were found among CRP
and LBP, IL-6 and LBP, and IL-6 and APACHE II scores. There were no fatalities in
the mild group, whereas four of the seven patients with severe disease died.
CONCLUSIONS: LBP was significantly raised in patients with severe acute
pancreatitis but would seem to be of limited use in predicting disease severity.
This acute phase protein may have a role in the progression of systemic
complications associated with acute pancreatitis.
PMID- 10667508
TI - Helicobacter pylori infection: a risk factor for upper gastrointestinal bleeding
after cardiac surgery?
AB - OBJECTIVE: To determine the prevalence of Helicobacter pylori (H. pylori) in
critically ill patients who develop upper gastrointestinal bleeding after cardiac
surgery in relation to other risk factors. DESIGN: Prospective, single center,
cohort study. SETTING: Surgical intensive care unit in a university hospital.
INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Over a 1-yr period, all
consecutive patients with upper gastrointestinal hemorrhage from the stomach or
duodenum were studied for H. pylori infection by serology. Additionally, the need
for mechanical ventilation over 48 hrs, the duration cardiopulmonary bypass, and
the aortic cross-clamp time were analyzed. For control, 229 patients with no
evidence of gastrointestinal hemorrhage after cardiac surgery were studied. All
patients received stress ulcer prophylaxis with ranitidine. Operations were
performed on 2,956 patients during the study period. The incidence of upper
gastrointestinal bleeding was 0.9%. Twenty (77%) of the 26 patients with upper
gastrointestinal bleeding and 145 (63%) patients of the control group had
serologic evidence for H. pylori infection (odds ratio, 1.9; 95% confidence
interval 0.7-5.0; p = .2). Patients who required prolonged mechanical ventilation
had a significantly greater risk for upper gastrointestinal bleeding (odds ratio,
22.1; 95% confidence interval 8.6-56.7; p<.001). Patients with upper
gastrointestinal bleeding also had a significantly longer duration of
cardiopulmonary bypass and aortic cross-clamp time (p<.001) CONCLUSIONS: H.
pylori is not associated with upper gastrointestinal bleeding in critically ill
patients who receive stress ulcer prophylaxis, whereas patients who require
prolonged mechanical ventilation are at high risk. A prophylactic eradication of
H. pylori is not justified.
PMID- 10667509
TI - Evolution of lactate/pyruvate and arterial ketone body ratios in the early course
of catecholamine-treated septic shock.
AB - OBJECTIVES: To measure arterial lactate/pyruvate (L/P) and arterial ketone body
ratios as reflection of cytoplasmic and mitochondrial redox state at different
stages of catecholamine-treated septic shock and compare them with normal and
pathologic values obtained in patients in shock who have decreased oxygen
transport (cardiogenic shock), and to assess the relationship between the time
course of lactate, L/P ratio, and mortality in septic shock. DESIGN: Prospective,
observational human study. SETTING: A university intensive care unit. PATIENTS:
Sixty consecutive adult patients who developed septic shock and lactic acidosis
requiring the administration of vasopressors. Twenty patients in the intensive
care unit without shock, sepsis, and hypoxia and with normal lactate values and
10 patients with cardiogenic shock were also studied. MEASUREMENTS: Hemodynamic
measurements, arterial and mixed venous blood gases, arterial lactate and
pyruvate concentrations, and arterial ketone body ratio were measured within 4
hrs after the introduction of catecholamine and 24 hrs later. MAIN RESULTS:
Fifteen patients (25%) died within the first 24 hrs of septic shock, and these
early fatalities had a higher blood lactate (12.2+/-3 versus 4.6+/-1.3 mmol/L;
p<.01) concentration and a higher L/P ratio (37+/-4 versus 20+/-1; p<.01) than
those who died later. No difference was found for arterial ketone body ratio
(0.41+/-0.1 versus 0.50+/-0.06). Forty-five patients survived >24 hrs including
25 survivors and 20 nonsurvivors. Although there was no difference between
survivors and nonsurvivors in initial lactate concentration (4.1+/-0.4 and 4.6+/
0.3, respectively), L/P ratio (19+/-1 and 20+/-1, respectively), and arterial
ketone body ratio (0.5+/-0.06 and 0.52+/-0.07, respectively), blood lactate and
L/P ratio significantly decreased during the first 24 hrs in the survivors (2.8+/
0.4 and 14+/-1, respectively; p<.05). and were stable in the nonsurvivors (4+/
0.3 and 22+/-1, respectively) Although returning to normal values after 24 hrs in
survivors and nonsurvivors, arterial ketone body ratio was higher in survivors
(1.72+/-0.17 versus 1.09+/-0.15; p<.05). Lactate and L/P ratio were closely
correlated (r2 = .8, p<.0001). In the cardiogenic shock group, lactate
concentration was 4+/-1 mmol/L, L/P ratio was 40+/-6, and arterial ketone body
ratio was 0.2+/-0.05. The mortality rate was 60%. CONCLUSIONS: The main result of
the present study is that hemodynamically unstable patients with sepsis needing
catecholamine therapy had a lactic acidosis with an elevated L/P ratio and a
decreased arterial ketone body ratio, suggesting a decrease in cytoplasmic and
mitochondrial redox state. The duration of lactic acidosis is associated with the
development of multiple organ failure and death.
PMID- 10667510
TI - Intensive care unit morbidity and mortality from eclampsia: an evaluation of the
Acute Physiology and Chronic Health Evaluation II score and the Glasgow Coma
Scale score.
AB - OBJECTIVE: To determine the maternal morbidity and mortality in patients with
eclampsia admitted to an intensive care unit (ICU), and to establish the efficacy
of the Acute Physiology and Chronic Health Evaluation (APACHE) II score, the
organ system failure score as defined by Knaus, and the Glasgow Coma Scale (GCS)
score in predicting outcome. DESIGN: Retrospective analysis of a 3.5-yr period.
SETTING: Surgical ICU in a university hospital. PATIENTS: A total of 105 patients
who were admitted with a diagnosis of eclampsia were studied. INTERVENTIONS:
None. MEASUREMENTS AND MAIN RESULTS: The data captured included the reason for
admission, maternal age, gestational age, parity, number of seizures, duration of
ICU stay, anticonvulsant therapy, drug therapy, GCS score, APACHE II score, and
the occurrence of organ failure. Of the 126 patients with eclampsia who were
admitted to the ICU, records of 105 patients (83%) were found. The overall
mortality was 10.5% (n = 11). The mean age, gestation, parity, number of
preadmission seizures, and duration of stay were similar in survivors and
nonsurvivors. Although the APACHE II score was significantly higher in
nonsurvivors, multiple logistic regression analysis suggested that the goodness
of-fit scores for GCS and APACHE II were similar (38.29 vs. 38.01). The GCS
scores of survivors were significantly higher than those of nonsurvivors (10.61
vs. 5.0; p<.001). Respiratory failure was the most common organ failure in both
groups. The mean number of organ failures was higher in nonsurvivors compared
with survivors (2.9 vs. 1.3; p<.001). An occurrence of more than two organ
failures that persisted for >48 hrs was invariably associated with a fatal
outcome. Anticonvulsant therapy consisted of magnesium sulfate or phenytoin and a
midazolam infusion. Only one patient (0.9%) had a seizure, and this occurred en
route to the ICU. No seizures occurred after admission to the ICU. CONCLUSIONS:
The organ system failure score and the GCS score are good predictors of outcome
in eclampsia. Apart from the GCS score, other variables in the APACHE II score
are not valuable for outcome prediction. The low GCS score in nonsurvivors
suggests that closer attention to the neurologic management may be beneficial. A
prospective study is indicated to validate these findings.
PMID- 10667511
TI - Initial severity of metabolic acidosis predicts the development of acute lung
injury in severely traumatized patients.
AB - OBJECTIVES: First, to determine whether the severity of shock, as measured by
systemic hypotension and metabolic acidosis, is significantly associated with a
higher risk of acute lung injury in patients with severe trauma. Second, to
determine whether the volumes of blood and crystalloid solutions administered in
the early posttrauma period are independent risk factors for acute lung injury in
severely traumatized patients. DESIGN: Prospective observational study. SETTING:
Level I urban trauma center in a university hospital. PATIENTS: A total of 102
severely injured, mechanically ventilated trauma patients with an Injury Severity
Score > or =16 and aged between 18 and 75 yrs. INTERVENTIONS: None. MEASUREMENTS
AND MAIN RESULTS: Initial clinical and laboratory data were collected in the
emergency department, and on a daily basis thereafter during the patient's
intensive care unit stay. Of the 102 severely injured patients enrolled, 42
developed acute lung injury (41%) and 60 did not (59%). A total of 93% of the
trauma patients who developed acute lung injury during the 17-month study period
were included in the study. Initial base deficit was significantly lower in
patients who developed acute lung injury than in those who did not (-8.8+/-4.5
vs. -5.6+/-5.1, p<.01). The difference in systolic blood pressure between the two
groups was not significant. CONCLUSIONS: In this group of severely injured trauma
patients, the degree of metabolic acidosis at the time of admission identified
those patients with the highest probability of developing acute lung injury. In
addition, the volume of crystalloid solution administered during the first 24 hrs
was significantly greater in patients who later developed acute lung injury.
Finally, there was a significantly higher morbidity in patients who developed
acute lung injury, whereas mortality did not differ between the two groups.
PMID- 10667512
TI - Relationship between central venous pressure and bioimpedance vector analysis in
critically ill patients.
AB - OBJECTIVE: To assess the relationship between central venous pressure values and
bioelectrical impedance vector analysis (BIVA), which may be used as
complementary methods in the bedside monitoring of fluid status. DESIGN: Cross
sectional evaluation of a consecutive sample. SETTING: Intensive care unit of a
university hospital. PATIENTS: One hundred and twenty-one consecutive Caucasian,
adult patients of either gender, for whom routine central venous pressure
measurements were available. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS:
Central venous pressure values and impedance vector components (i.e., resistance
and reactance) were determined simultaneously. Total body water predictions were
obtained from regression equations according to either conventional bioimpedance
analysis or anthropometry (Watson and Hume formulas). Variability of total body
water predictions was unacceptable for clinical purposes. Central venous pressure
values significantly and inversely correlated with individual impedance vector
components (r2 = .28 and r2 = .27 with resistance and reactance, respectively),
and with both vector components together (R2 = .31). Patients were classified in
three groups according to their central venous pressure value: low (0 to 3 mm
Hg); medium (4 to 12 mm Hg); and high (13 to 20 mm Hg). Three BIVA patterns were
considered: vectors within the target (reference) 75% tolerance ellipse (normal
tissue hydration); long vectors out of the upper pole of the target
(dehydration); and short vectors out of the lower pole of the target (fluid
overload). The agreement between BIVA and central venous pressure indications was
good in the high central venous pressure group (93% short vectors), moderate in
the medium central venous pressure group (35% normal vectors), and poor in low
central venous pressure group (10% long vectors). CONCLUSIONS: Central venous
pressure values correlated with direct impedance measurements more than with
total body water predictions. Whereas central venous pressure values >12 mm Hg
were associated with shorter impedance vectors in 93% of patients, indicating
fluid overload, central venous pressure values <3 mm Hg were associated with long
impedance vectors in only 10% of patients, indicating tissue dehydration. The
combined evaluation of intensive care unit patients by BIVA and central venous
pressure may be useful in therapy planning, particularly in those with low
central venous pressure in whom reduced, preserved, or increased tissue fluid
content can be detected by BIVA.
PMID- 10667513
TI - How much guidewire is too much? Direct measurement of the distance from
subclavian and internal jugular vein access sites to the superior vena cava
atrial junction during central venous catheter placement.
AB - OBJECTIVE: The introduction of excessive lengths of guidewire during placement of
central venous catheters from the internal jugular vein (IJV) or the subclavian
vein (SCV) can result in rare but significant complications. To identify a "safe"
guidewire insertion length, the authors performed direct intravascular
measurement of the distance from these venous access sites to the superior vena
cava-atrial junction (CAJ), and evaluated these distances relative to the
patients' height, weight, sex, and chest radiographs. DESIGN: Prospective,
nonrandomized observation. SETTING: The Interventional Radiology Department of a
tertiary care referral hospital. PATIENTS: 100 adults (45 women, 55 men)
evaluated during fluoroscopically directed central venous catheter placement.
INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The distance from the IJV or
SCV access site was directly measured using fluoroscopy and an intravascular
guidewire. 40 right IJVs, 31 right SCVs, 16 left SCVs, and 13 left IJVs were
studied. Comparative measurements from the postprocedure radiograph were made in
20 of these cases. All measurements were correlated with patient sex, height, and
weight. The mean distance from all access sites to the superior vena cava-atrial
junction was 18.0 cm. The right IJV distance was the shortest, averaging 16 cm.
The left SCV distance was the longest, averaging 21.2 cm. Right SCV and left IJV
distances were 18.4 and 19.1 cm, respectively, but this difference was not
statistically significant. Weight and radiographic measurements did not correlate
with the measured vascular distance, although there was a trend toward longer
distances in taller patients and males. CONCLUSIONS: Patient height, weight, and
measurements from previous chest radiographs are less reliable in predicting a
safe wire length than is the access site selected. In most cases, 18 cm should be
considered the upper limit of guidewire introduced during central catheter
placement in adults. The guidewires supplied in catheter kits should have lengths
correlated to those of the catheters, and should have distance markings printed
upon them.
PMID- 10667514
TI - Protein carbonyl measurements show evidence of early oxidative stress in
critically ill patients.
AB - OBJECTIVE: To determine whether there is evidence of oxidative injury in patients
who are critically ill with severe sepsis or major trauma, by measuring protein
and lipid oxidation products. DESIGN: A prospective, observational study.
SETTING: Critical care unit at a university teaching hospital. PATIENTS: Twenty
two patients with severe sepsis (Acute Physiology and Chronic Health Evaluation
II score 15-34) and eight patients with major trauma (Injury Severity Score 26
50). INTERVENTIONS: Plasma and bronchoalveolar lavage fluid was collected
regularly during the first 10 days after trauma or onset of sepsis. Both fluids
were analyzed for protein carbonyl concentrations as a measure of protein
oxidation and thiobarbituric acid-reactive substances as a measure of lipid
peroxidation. Myeloperoxidase concentrations were measured as an index of
neutrophil activation. MEASUREMENTS AND MAIN RESULTS: Protein carbonyl
concentrations were initially highly elevated compared with those in healthy
adults in the plasma of both patient groups. They fell significantly within the
first few days but remained above control values. Protein carbonyl concentrations
were also high initially in bronchoalveolar lavage fluid and fell significantly
with time. Thiobarbituric acid-reactive substances were not increased in plasma,
and varied over a wide concentration range in lavage fluid. Myeloperoxidase
activity reached micromolar levels in the lavage fluid when corrected for
dilution, and was significantly higher in the plasma of the sepsis patients who
subsequently died. There was a strong correlation between carbonyl concentrations
in lavage fluid and plasma, and between protein carbonyls, thiobarbituric acid
reactive substances and myeloperoxidase in the lungs. CONCLUSIONS: Our results
provide evidence of oxidation occurring early in severe sepsis and major trauma
patients, with protein carbonyl measurements providing a sensitive index of this
process. High protein carbonyl concentrations in plasma as well as bronchial
aspirates indicate that oxidation is not restricted to the lungs. The correlation
between oxidative measures and myeloperoxidase concentrations in the lung
indicates that neutrophil oxidants could be responsible for the injury.
PMID- 10667515
TI - Short-term and long-term outcome prediction with the Acute Physiology and Chronic
Health Evaluation II system after orthotopic liver transplantation.
AB - OBJECTIVE: To evaluate the relationship between the postoperative Acute
Physiology and Chronic Health Evaluation (APACHE) II score and mortality at
hospital discharge and at 1 yr in liver transplant recipients. POPULATION: Adult
orthotopic liver transplant (OLTX) recipients (n = 599) admitted to the intensive
care unit postoperatively at a university hospital. METHODS: The cohort was split
randomly into development and validation sets. Three models were compared for
each end point: a) the original APACHE II slope with the original APACHE II
postgastrointestinal surgery intercept; b) the original APACHE II slope with an
OLTX-specific intercept generated from the development set; and c) an OLTX
specific slope and intercept generated from the development set. Goodness-of-fit
and calibration were assessed by the Hosmer-Lemeshow C statistic (where p>.05
suggests good fit) and standardized mortality ratios. Discrimination was assessed
by receiver operator characteristic area under the curve analysis. MEASUREMENTS
AND MAIN RESULTS: Hospital and 1-yr mortality rates were 9.9% and 15.9%,
respectively. The APACHE II score was strongly associated with mortality (chi
square, p<.0001), but when used with the original equation, it significantly
overestimated hospital mortality (standardized mortality ratio, 0.73 [confidence
interval, 0.58-0.99]). Using the OLTX-specific approaches, goodness-of-fit for
both hospital and 1-yr mortality was good (p = .2-.57) but discrimination was
only moderate (receiver operator characteristic area under the curve, 0.675
0.723). CONCLUSIONS: APACHE II is a good predictor of short- and long-term
mortality after liver transplantation, especially when using OLTX-specific
coefficients. Because fit and calibration were better than discrimination, APACHE
II will be most useful in the prediction of risk for groups of patients (e.g., in
clinical trials or institutional comparisons) rather than for individuals. This
study raises the possibility that APACHE II may be useful for long-term mortality
prediction in other critically ill populations. The overestimation of mortality
using the original equation suggests that orthotopic liver transplantation, by
reversing the underlying pathophysiology, may modify risk.
PMID- 10667516
TI - Neonatal cerebral oxygen regulation after hypothermic cardiopulmonary bypass and
circulatory arrest.
AB - OBJECTIVE: Despite technical advances, neurologic sequelae continue to occur in
neonates after heart surgery using deep hypothermic cardiopulmonary bypass
(dhCPB) and circulatory arrest (DHCA). This study sought to determine the
cerebral microcirculatory responses to hypoxia, hypotension, hypocapnia, and
hypercapnia after dhCPB and DHCA. DESIGN: Prospective laboratory animal trial.
SETTING: Research laboratory. SUBJECTS: Twenty-eight newborn pigs. INTERVENTIONS:
Piglets were divided into control, dhCPB, and DHCA groups. The control group
received surgery. The dhCPB group received surgery and deep hypothermic CPB for
40 mins. The DHCA group received surgery, deep hypothermic CPB for 40 mins, and
circulatory arrest for 60 mins. Two hours after the intervention, cerebral
microcirculatory responses were examined. MEASUREMENTS AND MAIN RESULTS: Cerebral
microcirculatory responses consisted of changes in cerebral oxygen saturation
(Sco2) and pial arteriolar diameter measured by near- infrared spectroscopy and
intravital microscopy, respectively. All groups experienced similar decreases in
Sco2 and increases in pial arteriolar diameter in response to moderate and severe
hypoxia (Pao2, 35 and 25 torr, respectively) and moderate and severe hypotension
(mean pressure, 30 and 20 mm Hg, respectively). Sco2 and pial arteriolar diameter
decreased to hypocapnia (Paco2, 25 torr) similarly in all groups. To hypercapnia
(Paco2, 70 torr), Sco2 increased in the control group, did not change in the
dhCPB group, and decreased in the DHCA group. Pial arteriolar diameter to
hypercapnia increased in the control and the dhCPB groups but did not change in
the DHCA group. CONCLUSIONS: Cerebral vascular and oxygenation responses to
hypoxia, hypocapnia, and hypotension were preserved after dhCPB and 1 hr of DHCA.
By comparison, cerebral vascular and oxygenation responses to hypercapnia were
not; both vascular and oxygenation responses were altered after DHCA, but only
the oxygenation response was altered after dhCPB. These data suggest a selective
disturbance in the microcirculation and/or parenchymal oxygen metabolism after
DHCA and dhCPB.
PMID- 10667517
TI - Hypertonic saline dextran produces early (8-12 hrs) fluid sparing in burn
resuscitation: a 24-hr prospective, double-blind study in sheep.
AB - OBJECTIVE: Resuscitation of large burn injuries must quickly restore and maintain
cardiovascular function and fluid balance while minimizing secondary edema
related damage. We tested the hypothesis that two 4-mL x kg(-1) doses of
hypertonic saline dextran (HSD; 7.5% NaCl/6% dextran-70) can produce prolonged
reduction in fluid requirements after burn injury. DESIGN: Prospective, pseudo
randomized, double-blind study. SETTING: Animal research laboratory. SUBJECTS:
Female adult Merino sheep (n = 12). INTERVENTIONS: Sheep were given a 40% total
body surface area full-thickness flame burn under halothane anesthesia. One hour
after the burn, the conscious animals received an initial dose of 4 mL x kg(-1)
HSD (n = 6) or normal saline (NS; NaCl 0.9%) (n = 6) intravenously during 30
mins. This was followed by lactated Ringer's solution, infused to a target urine
output of 1 mL x kg(-1) x hr(-1) throughout the 24-hr study. A second 4-mL x kg(
1) dose of HSD or NS was started at 12 hrs, and infused during 5 hrs.
MEASUREMENTS AND MAIN RESULTS: Hourly urine output measurements were used to
guide the infusion rate of the lactated Ringer's. The initial infusion of HSD 1
hr after the burn injury promptly restored cardiac index, promoted diuresis, and
reduced fluid requirements compared with the NS controls (73% reduction for HSD
relative to NS at 8 hrs). Subsequent rebound fluid accumulation resulted in
similar net fluid balances in both groups within 12 hrs after the burn. The
second dose of HSD, given at 12 hrs, was without effect on hemodynamics and fluid
balance. CONCLUSIONS: We conclude a considerable initial, but not sustained fluid
sparing effect of early HSD, and no effect of a late, slowly infused HSD dose in
this two-dose regimen.
PMID- 10667518
TI - Propofol impairment of mitochondrial respiration in isolated perfused guinea pig
hearts determined by reflectance spectroscopy.
AB - OBJECTIVE: To simultaneously determine the effect of propofol on myocardial
oxygenation, mitochondrial function, and whole organ function in an isolated
heart model, using optical reflectance spectroscopy. DESIGN: Controlled
laboratory investigation. SETTING: Research laboratory. SUBJECTS: Twenty adult
guinea pigs. INTERVENTIONS: Isolated hearts were perfused alternately with a
modified oxygenated Krebs-Henseleit buffer and with buffer containing varied
concentrations of propofol. Ninety seconds of ischemia were produced during
perfusion with each solution studied. MEASUREMENTS AND MAIN RESULTS: Myoglobin
oxygen saturation, cytochrome c and cytochrome a/a3 redox state, and ventricular
pressure were continuously measured from isolated guinea pig hearts during a 2-hr
period. Myoglobin oxygen saturation increased and both cytochromes became more
oxidized in the presence of propofol. During ischemia, myoglobin desaturation and
cytochrome reduction were delayed and less complete in the presence of propofol.
The mean ischemic time to 50% myoglobin desaturation was, on average, 14.3 secs
with buffer perfusion, and increased to 24.5, 27.9, and 41.8 secs, with 50, 100,
and 200 microM propofol perfusion, respectively. Ventricular function decreased
linearly with increasing propofol concentration. From baseline buffer perfusion,
maximal dP/dt per cardiac cycle decreased on average by 30.4%, 40.9%, and 69.4%,
with 50, 100, and 200 microM propofol perfusion, respectively. CONCLUSIONS:
Propofol impairs either oxygen utilization or inhibits electron flow along the
mitochondrial electron transport chain in the guinea pig cardiomyocyte. Propofol
also significantly decreases ventricular performance in the isolated perfused
heart. These effects are linearly correlated with propofol concentration in the
range studied.
PMID- 10667519
TI - Regional pressure volume curves by electrical impedance tomography in a model of
acute lung injury.
AB - OBJECTIVE: A new noninvasive method, electrical impedance tomography (EIT), was
used to make pressure-impedance (PI) curves in a lung lavage model of acute lung
injury in pigs. The lower inflection point (LIP) and the upper deflection point
(UDP) were determined from these curves and from the traditional pressure-volume
(PV) curves to determine whether the PI curves resemble the traditional PV
curves. Furthermore, regional differences in the mentioned determinants were
investigated. DESIGN: Prospective, experimental study. SETTING: Animal research
laboratory. INTERVENTIONS: In nine anesthetized pigs, repeated lung lavage was
performed until a Pao2 <80 torr was reached. Thereafter, an inspiratory PV curve
was made using a constant flow of oxygen. During the intervention, EIT
measurements were performed. MEASUREMENTS AND MAIN RESULTS: In this study, the
LIP(EIT) was within 2 cm H2O of the LIP(PV). Furthermore, it was possible to
visualize regional PI curves by EIT. No significant difference was found between
the LIP(PV) (21.3+/-3.0 cm H2O) and the LIP(EIT) of the total lung (21.5+/-3.0 cm
H2O) or the anterior parts of the lung (21.5+/-2.9 cm H2O). A significantly
higher LIP (29.5+/-4.9 cm H2O) was found in the posterior parts of the lung. A
UDP(PV) could be found in three animals only, whereas in all animals a UDP(EIT)
could be determined from the anterior part of the lung. CONCLUSIONS: Using EIT,
determination of LIP and UDP from the regional PI curves is possible. The
obtained information from the regional PI curves may help in understanding
alveolar recruitment. The use of this new bedside technique for clinical decision
making remains to be examined.
PMID- 10667520
TI - Effect of naloxone on immune responses after hemorrhagic shock.
AB - OBJECTIVE: To determine whether naloxone administration after hemorrhagic shock
has any beneficial or deleterious effect on immune responses. BACKGROUND DATA:
Hemorrhagic shock is known to produce immunodepression in both humans and
experimental animals. Although studies suggest that endogenous opioids play a
role in immune regulation in adverse circulatory conditions, it remains
controversial whether these opioids exert beneficial or detrimental effects on
immunity after shock. Moreover, little information is available concerning the
effects of opioid receptor blockade using naloxone on cell-mediated immunity and
endocrine responses after shock. METHODS: Male C3H/HeN mice (25 g) were bled to
and maintained at a mean arterial blood pressure of 35+/-5 mm Hg for 1 hr. The
shed blood was then returned along with lactated Ringer's solution (two times the
shed blood volume) to provide fluid resuscitation. The animals were randomized to
receive either naloxone (1 mg/kg i.v.) or an equal volume of vehicle (saline)
after the shed blood was returned, i.e., immediately before crystalloid
resuscitation, and were killed at 2 hrs after resuscitation to obtain
splenocytes, macrophages (peritoneal and splenic), and blood. MEASUREMENTS AND
MAIN RESULTS: Bioassays revealed significantly decreased release of all studied
interleukins (interleukins-1, -2, -3, and -6) by peritoneal and splenic
macrophages as well as significantly decreased splenocyte proliferative capacity
after shock in vehicle-treated mice. Naloxone administration after hemorrhage
resulted in either similar or even more decreased levels of interleukin release
compared with vehicle-treated hemorrhaged mice. Significantly increased plasma
corticosterone concentrations were observed in vehicle-treated animals compared
with control animals. Naloxone administration did not have any significant
effects on corticosterone plasma concentrations after hemorrhage. CONCLUSIONS:
These findings indicate the importance of the endogenous opioid system for the
maintenance of immunity in adverse circulatory conditions, i.e., hemorrhage.
Although additional studies involving different doses and/or times of naloxone
administration may provide different results, the present findings raise the
concern that naloxone administration in the traumatized host may have deleterious
effects because it decreases peritoneal macrophage and splenic immune functions.
PMID- 10667521
TI - Oxotremorine-induced cerebral hyperemia does not predict infarction volume in
spontaneously hypertensive or stroke-prone rats.
AB - OBJECTIVES: We tested the following hypotheses: a) spontaneously hypertensive
stroke-prone rats (SHR-SP) have more brain injury than spontaneously hypertensive
rats (SHR) and normotensive controls (Wistar-Kyoto rats [WKY]) when exposed to
transient focal ischemia; b) infarction size is not correlated with baseline
blood pressure; and c) infarction size is inversely related to the cerebral
hyperemic response to oxotremorine, a muscarinic agonist that increases cerebral
blood flow (CBF) by stimulating endothelial nitric oxide synthase. DESIGN: In
vivo study. SETTING: Animal laboratory in a university teaching hospital.
SUBJECTS: Adult age-matched male WKY, SHR, and SHR-SP. INTERVENTIONS: Rats were
instrumented under halothane anesthesia. Transient focal cerebral ischemia was
produced for 2 hrs with the intravascular suture technique. Cerebral perfusion,
estimated with laser Doppler flowmetry (LD-CBF), in response to intravenous
oxotremorine, was measured in one cohort of rats to estimate endothelial nitric
oxide synthase function. Infarction volume was measured at 22 hrs of reperfusion
with 2,3,5-triphenyltetrazolium chloride staining. MEASUREMENTS AND MAIN RESULTS:
Infarction volume in the striatum of SHR-SP (42+/-4 mm3) was greater than in SHR
(29+/-6 mm3) or WKY (1+/-1 mm3) (n = 9 rats/strain). Resting (unanesthetized)
mean arterial blood pressure was similar in SHR-SP (177+/-5 mm Hg) and SHR (170+/
5 mm Hg) despite a greater infarction volume in SHR-SP (n = 4) compared with SHR
(n = 5). The percentage increase in LD-CBF signal in response to oxotremorine was
similar for both groups (SHR, 64%+/-22% [n = 10]; SHR-SP, 69%+/-22% [n = 8]).
However, in this cohort, cortical infarction volume was less in SHR (30%+/-4% of
ipsilateral cortex) than in SHR-SP (49%+/-2% of ipsilateral cortex). CONCLUSIONS:
Although SHR-SP have greater infarction volume than SHR, the mechanism of injury
does not appear to be related to a difference in unanesthetized baseline mean
arterial blood pressure or to an alteration in endothelium-produced nitric oxide.
PMID- 10667522
TI - Antioxidant LY231617 enhances electrophysiologic recovery after global cerebral
ischemia in dogs.
AB - OBJECTIVE: The potent antioxidant LY231617 (2,6-bis(1,1-dimethylethyl)-4-[[(1
ethyl)amino]methyl]phenol hydrochloride) is cytoprotective in models of focal and
global cerebral ischemia. We tested the hypothesis that administration of
LY231617, before the insult, would improve recovery of cerebral electrical
activity and metabolic function after transient global cerebral ischemia by
improving cerebral blood flow (CBF) during the reperfusion period. DESIGN:
Randomized, controlled, prospective study. SETTING: Research laboratory at a
university teaching hospital. SUBJECTS: Twenty-four male beagle dogs.
INTERVENTIONS: All experiments were performed under pentobarbital anesthesia and
controlled conditions of normoxia, normocarbia, and normothermia. Twelve control
dogs received 20 mL/kg saline (vehicle) bolus into the right atrium and 0.01
mL/kg/min i.v., beginning 20 mins before 13 mins of global cerebral ischemia (by
aortic occlusion). The dogs in the drug-treated group received LY231617 as a 10
mg/kg bolus 20 mins before ischemia and 5 mg/kg/hr throughout reperfusion (n =
12). CBF was measured using radiolabeled microspheres. MEASUREMENTS AND MAIN
RESULTS: Total CBF, cerebral oxygen consumption, and somatosensory evoked
potentials (SEP) were measured during 240 mins of reperfusion. CBF was similar in
both vehicle- and LY231617-treated animals at baseline and throughout the
experimental period. In all animals, SEP became isoelectric between 60 and 100
secs after cross-clamping of the ascending aorta. SEP amplitude recovery was
significantly higher in drug-treated animals compared with controls (73%+/-15%
vs. 39%+/-14% [mean+/-SEM] from baseline at 120 mins [p<.05] and 86%+/-12% vs.
49%+/-14% from baseline at 240 mins [p< .05]). CONCLUSIONS: LY231617 improves
recovery of cerebral electrical function after complete transient global ischemia
via mechanisms unrelated to cerebral circulatory effects.
PMID- 10667523
TI - Partial liquid ventilation with perflubron attenuates in vivo oxidative damage to
proteins and lipids.
AB - OBJECTIVE: To determine the impact of partial liquid ventilation on the degree of
pulmonary damage by reactive oxygen species in a model of acute lung injury
caused by systemic endotoxemia. DESIGN: A prospective, controlled, in vivo,
animal laboratory study. SETTING: Animal research facility of a health sciences
university. SUBJECTS: Forty New Zealand White rabbits. INTERVENTIONS: Mature
rabbits were anesthetized and instrumented with a tracheostomy and vascular
catheters. Animals were assigned to receive either partial liquid ventilation (n
= 16) with perflubron (18 mL/kg via endotracheal tube) or conventional mechanical
ventilation (n = 16). Both groups were ventilated using similar strategies, with
an Fio2 of 1.0 and tidal volume as required to obtain a normal Paco2. Animals
were then given 0.9 mg/kg Escherichia coli endotoxin intravenously over 30 mins.
Eight uninjured instrumented and mechanically ventilated animals served as
controls. Partial liquid ventilation or conventional ventilation was continued
for 4 hrs before the animals were killed. Lung homogenates were analyzed for
malondialdehyde (MDA) and 4-hydroxy-2(E)-nonenal (4-HNE) concentrations using a
colorimetric assay. To assess protein oxidative damage, carbonyl groups in
protein side chains were derivatized with 2,4-dinitrophenylhydrazine followed by
Western blotting with a dinitrophenylated-specific primary antibody. MEASUREMENTS
AND MAIN RESULTS: MDA (713.42+/-662 vs. 1601.4+/-1156 nmol/g protein; p = .023)
and MDA plus 4-HNE (1480.24+/-788 vs. 2675.2+/-1628 nmol/g protein; p = .038)
concentrations were lower in animals treated with partial liquid ventilation
compared with conventionally ventilated animals, respectively. Animals treated
with partial liquid ventilation exhibited attenuation of dinitrophenylated
derivatized protein bands by Western blotting, indicating a reduction in protein
oxidative damage. The presence of perfluorocarbon did not interfere with the MDA
assay when assessed by independent analysis in vitro. Perflubron did not serve as
a sink for peroxyl radicals produced in the aqueous phase during separate in
vitro oxidation experiments. CONCLUSIONS: Partial liquid ventilation attenuates
oxidative damage to lipids and proteins during experimental acute lung injury.
This finding is not caused by binding of lipid peroxidation products to
perflubron or by the peroxyl radical scavenging properties of perflubron.
PMID- 10667524
TI - Brain blood flow patterns after the development of congestive heart failure:
effects of treadmill exercise.
AB - OBJECTIVE: Congestive heart failure (CHF) is associated with left ventricular
(LV) failure, neurohormonal system activation, and diminished exercise capacity.
Although alterations in systemic vascular resistive properties have been
recognized to occur with CHF, whether and to what degree perfusion abnormalities
occur within the brain after the development of CHF remain poorly understood.
Accordingly, the present study measured brain blood flow patterns in pigs after
the development of pacing-induced CHF at rest and after treadmill-induced
exercise. MEASUREMENTS AND MAIN RESULTS: Adult pigs (n = 6) were studied before
and after the development of pacing-induced CHF (240 beats/min, 3 wks) at rest
and with treadmill exercise (3 mph, 15 degrees incline, 10 mins). At rest, LV
stroke volume was reduced nearly 45% with CHF compared with normal (20+/-2 vs.
36+/-3 mL; p<.05) and was associated with a more than four-fold increase in
plasma catecholamines, renin activity, and endothelin concentration. At rest,
global brain blood flow was reduced with CHF compared with the normal state
(1.06+/-0.13 vs. 0.81+/-0.06 mL/min/g; p<.05). At rest, blood flow to the frontal
lobe, cerebellum, and medullary regions was reduced by approximately 30% in the
CHF group (p<.05). With treadmill exercise, LV stroke volume remained lower and
neurohormonal concentrations remained higher in the pacing CHF state. Global
brain blood flow increased significantly with treadmill exercise in both the
normal and CHF states (4.58+/-1.36 and 2.01+/-0.29 mL/min/g; p<.05) but remained
reduced in the CHF state compared with normal values (p<.05). In the CHF group,
the relative increase in blood flow with exercise was significantly blunted in
the parietal and occipital regions of the cerebrum and the suprapyramidal region
of the medulla. CONCLUSIONS: The development of pacing-induced CHF was associated
with diminished brain perfusion under resting conditions and with treadmill
exercise. These perfusion abnormalities with pacing CHF were pronounced in
specific regions of the brain. The defects in brain perfusion with the
development of CHF may contribute to abnormalities in centrally mediated
processes of cardiovascular regulation.
PMID- 10667525
TI - Cerebrospinal fluid tumor necrosis factor-alpha, interleukin-1beta, interleukin
6, and interleukin-8 as diagnostic markers of cerebrospinal fluid infection in
neurosurgical patients.
AB - OBJECTIVE: To evaluate whether cerebrospinal fluid concentrations of tumor
necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, or IL-8 may be used as
diagnostic markers for the differential diagnosis of aseptic vs. bacterial
meningitis and/or ventriculitis in neurosurgical patients. DESIGN: Prospective,
observational study. SETTING: University teaching hospital. SUBJECTS: A total of
112 cerebrospinal fluid samples from 14 asymptomatic patients with normal
cerebrospinal fluid after neurosurgery, 27 asymptomatic and 19 symptomatic
patients with postneurosurgical aseptic meningitis, 32 patients with
postneurosurgical cerebrospinal fluid infection, and 20 with severe subarachnoid
and/or cerebral hemorrhage. MEASUREMENTS AND MAIN RESULTS: Specific ELISA kits
were used to analyze TNF-alpha, IL-1beta, IL-6, and IL-8 concentrations on
cerebrospinal fluid samples. Elevations in cerebrospinal fluid concentrations of
TNF-alpha, IL-1beta, IL-6, and IL-8 were induced by different diseases or
neurosurgical procedures, but cerebrospinal fluid bacterial infection induced the
highest concentrations. To discriminate between aseptic cerebrospinal fluid
pleocytosis and cerebrospinal fluid infection with a specificity of 95%,
cerebrospinal fluid leukocyte count >1700/mL, TNF-alpha >150 pg/mL, and IL-1beta
>90 pg/mL showed sensitivities of 51%, 74%, and 90%, respectively. Sufficiently
sensitive and specific cutoff points could not be found for cerebrospinal fluid
IL-6 or IL-8. CONCLUSION: Cerebrospinal fluid IL-1beta appears to be the best
biochemical marker of cerebrospinal fluid infection in neurosurgical patients.
PMID- 10667526
TI - Post-intensive care unit pediatric hospital stay and estimated costs.
AB - OBJECTIVE: For pediatric intensive care unit (ICU) survivors, to determine the
proportion of hospital stay and estimated hospital costs accounted for by post
ICU care. DESIGN: Prospective study. SETTING: University teaching hospital.
PATIENTS: Pediatric patients who survive an ICU admission. INTERVENTIONS: None.
MEASUREMENTS AND MAIN RESULTS: Estimated relative daily costs were assumed as
follows: ICU, with ventilator/ICU, not on ventilator/intermediate care
unit/general pediatric hospital day, at 2:1:0.7:0.3, respectively. Estimated
costs were expressed in arbitrary units as (number of days at each level of care)
x (relative cost per day). The ICU phase was defined as the patient's first ICU
admission only, and the post-ICU phase included intermediate care unit and
general pediatric hospital days, as well as ICU readmission during the same
hospitalization. Pre-ICU hospital activity was excluded from analysis. For 341
ICU survivors, post-ICU days (median, 4 days per patient) accounted for 62% of
the total hospital stay. Post-ICU care accounted for one third of the total
estimated hospital costs for ICU survivors. Patients with longer post-ICU stays
could not be reliably identified at the time of ICU discharge according to their
ICU length of stay, duration of mechanical ventilation in the ICU, age, ICU day 1
mortality probability, or diagnostic group (p>.05). CONCLUSIONS: Post-ICU care
accounts for a substantial proportion of hospital stay and estimated costs for
ICU survivors. These observations suggest that developing strategies to optimize
hospital utilization at the time of ICU discharge may be important for
controlling costs of recovery from critical illness.
PMID- 10667527
TI - Capillary blood gases in a pediatric intensive care unit.
AB - OBJECTIVE: To determine if samples obtained from arterial and capillary sources
are comparable in children with diverse pathologic conditions during their stay
in a pediatric intensive care unit. STUDY DESIGN: Prospective, descriptive study
in patients admitted to a multidisciplinary pediatric intensive care unit.
INTERVENTIONS: Seventy-five simultaneous paired samples (arterial and capillary)
were obtained from patients with different degrees of capillary reperfusion,
hemodynamic stability, blood pressure, and temperature. Both samples were
analyzed < or =5 mins after collection. MEASUREMENTS AND MAIN RESULTS: The
average correlations between arterial and capillary samples were 0.87 for pH,
0.86 for CO2, and 0.65 for oxygen. Neither poor perfusion nor low temperature
altered the correlation for pH or CO2. The only condition that significantly
affected the correlation was hypotension. CONCLUSION: Capillary blood sampling is
a useful alternative to gasometric evaluation of critically ill children, even in
the presence of hypothermia or hypoperfusion, provided that hypotension is not
present.
PMID- 10667528
TI - Conventional ventilation versus high-frequency oscillation: hemodynamic effects
in newborn babies.
AB - OBJECTIVE: We conducted a prospective study to assess the hemodynamic effects of
conventional mechanical ventilation (CMV) compared with high-frequency
oscillation (HFO) in newborn babies with respiratory distress syndrome. METHODS:
A total of 18 consecutive term and preterm infants were examined by two
dimensional M-mode and pulsed Doppler echocardiography. RESULTS: Five patients
had to be excluded, three of them because of increasing cardiovascular support
after initiation of HFO. The remaining 13 infants (seven males, six females) had
a median gestational age of 33 wks (range, 25-40) and a birth weight of 2350 g
(range, 790-3600). Patients entered the study at 21 hrs (range, 5-69) of life,
receiving total maintenance fluid of 90 mL/kg/day (range, 60-120). Five babies
(38%) needed continuous inotropic support. HFO was used as a rescue therapy in
infants who failed with CMV. In all 13 patients, HFO significantly impaired
cardiac performance compared with CMV by decreasing aortic velocity-time
integral: median, 10.2 cm (range, 6.0-14.6) vs. 8.3 cm (range, 5.3-12.4; p<.002);
stroke volume: median, 3.8 mL (range, 1.6-6.8) vs. 3.2 mL (range, 1.3-5.9;
p<.002); and cardiac index: 281 mL/min/kg of body weight (range, 177-579) vs. 200
mL/min/kg of body weight (range, 156-591; p<.002). Fractional shortening was also
significantly reduced: median, 0.31% (range, 0.24-0.44) vs. 0.29% (range, 0.20
0.34; p<.01), because of a significantly smaller left ventricular diastolic
diameter during HFO: median, 1.4 cm (range, 1.0-1.9) vs. 1.4 cm (range, 0.9-1.8;
p<.05), with a median difference of -0.07 cm (range, -0.4-0.2). HFO also causes a
significant decrease in heart rate-corrected left ventricular ejection time:
median, 0.25 sec (range, 0.23-0.28) vs. 0.23 sec (range, 0.21-0.26; p < .02) and
heart rate-corrected velocity of circumferential fiber shortening (Vcfc): median,
1.3 circ/sec (range, 1.0-1.6) vs. 1.2 circ/sec (range, 0.9-1.4; p<.05). Left
ventricular end-systolic wall stress (LVESWS; g/cm2) remained stable. The
correlation between Vcfc and LVESWS did not show any significance (CMV, r2 = .2;
HFO, r2 = .09). The regression line between Vcfc and LVESWS showed a higher y
intercept and steeper slope during CMV than during HFO. Heart rate, mean arterial
pressure, and left ventricular systolic diameter remained unchanged. CONCLUSIONS:
In newborn babies, HFO significantly decreased left ventricular cardiac output
caused by reduced left ventricular filling and HFO decreased contractility at
higher mean airway pressures than with CMV.
PMID- 10667529
TI - Consensus conference definitions for sepsis, septic shock, acute lung injury, and
acute respiratory distress syndrome: time for a reevaluation.
AB - Definitions for sepsis, septic shock, acute lung injury (ALI), and acute
respiratory distress syndrome (ARDS) were developed by consensus conferences with
the goal of achieving standardization of terminology and improved homogeneity of
patient populations in clinical studies. Although such definitions have been
useful in epidemiologic investigations, the criteria specified by the consensus
conferences are broad and insufficiently specific to address the problem of
heterogeneous mechanisms leading to clinical syndromes. An important challenge is
to progress from clinical syndromes, as presently defined, to more specific
entities that are delineated by alterations in specific immunologic or
biochemical pathways. Such mechanistic definitions will provide more homogeneous
groups of patients who can be identified at early stages of their clinical
course. This approach encourages focused investigation of pathways leading to
organ system dysfunction and death and, also, provides an efficient framework for
the development of new therapies useful in critically ill patients.
PMID- 10667530
TI - Consensus report for regionalization of services for critically ill or injured
children. Council of the Society of Critical Care Medicine.
AB - The care of critically ill children has become more complex and demanding. This
document establishes recommendations for developing regionalized integration of
the care of these children into the emergency medical services system. These
recommendations were developed by pediatricians with expertise in pediatric
critical care, transport, and emergency medicine from the Pediatric Section of
the Society of Critical Care Medicine Task Force on Regionalization of Pediatric
Critical Care and the Committee on Pediatric Emergency Medicine from the American
Academy of Pediatrics. The document was developed from existing guidelines from a
number of professional organizations (including the Society of Critical Care
Medicine and the American Academy of Pediatrics), a thorough review of the
literature, and expert consensus.
PMID- 10667531
TI - Unexpected Ebola virus in a tertiary setting: clinical and epidemiologic aspects.
AB - OBJECTIVES: To describe the clinical manifestations of viral hemorrhagic fever,
and to increase clinicians' awareness and knowledge of these illnesses. DESIGN:
Retrospective study of the clinical and laboratory data and management of two
cases of Ebola virus infection with key epidemiologic data provided. SETTING: Two
tertiary care hospitals. PATIENTS: Two adult patients, the index case and the
source patient, both identified as having Ebola, one of whom originated in Gabon.
INTERVENTIONS: One patient was admitted to the intensive care unit. The other was
managed in a general ward. MEASUREMENT AND MAIN RESULTS: Clinical and laboratory
data are reported. One patient, a healthcare worker who contracted this illness
in the course of her work, died of refractory thrombocytopenia and an
intracerebral bleed. The source patient survived. Despite a long period during
which the diagnosis was obscure, none of the other 300 contacts contracted the
illness. CONCLUSIONS: Identification of high-risk patients and use of universal
blood and body fluid precautions will considerably decrease the risk of
nosocomial spread of viral hemorrhagic fevers.
PMID- 10667532
TI - Use of high-dose corticosteroids and high-frequency oscillatory ventilation for
treatment of a child with diffuse alveolar hemorrhage after bone marrow
transplantation: case report and review of the literature.
AB - BACKGROUND: Other than relapse, pulmonary complications are the most common cause
of mortality in patients who undergo bone marrow transplantation (BMT). Diffuse
alveolar hemorrhage (DAH) is one noninfectious pulmonary complication of BMT.
Presenting clinical findings include nonproductive cough usually without
hemoptysis, dyspnea, hypoxemia, a decrease in hematocrit, and diffuse infiltrates
on chest radiograph. PATIENT: We report a case of DAH after allogeneic BMT in a 6
yr-old female patient. Although a chest radiograph revealed patchy bilateral
alveolar densities and large volumes of bright red blood were suctioned from the
endotracheal tube, there was no evidence of coagulopathy and no infectious agent
was identified on examination of bronchoalveolar lavage fluid, blood, and urine.
INTERVENTION: The child was treated with high-dose corticosteroids and high
frequency oscillatory ventilation and experienced a complete clinical recovery
from her pulmonary disease. RESULTS: The definition, presenting symptoms,
findings and timing, and associated risk factors of DAH after BMT are reviewed.
Prospective hypotheses for the pathogenesis of DAH after BMT are presented.
Evidence for the role of high-dose corticosteroids for treatment of DAH after BMT
and the role of high-frequency oscillatory ventilation for treatment of acute
hypoxemic respiratory failure in children with diffuse alveolar disease is also
reviewed. CONCLUSION: This case supports the contention that early treatment with
high-dose corticosteroids is warranted in children with DAH after BMT.
PMID- 10667533
TI - Vasopressin as an alternative to norepinephrine in the treatment of milrinone
induced hypotension.
AB - OBJECTIVE: To determine whether vasopressin could be effective in treating the
hypotension associated with phosphodiesterase III inhibition. Phosphodiesterase
III inhibitors are cardiotonic agents that increase myocardial contractility and
decrease vascular smooth muscle tone. The vasodilatory effect can be profound,
and the resulting hypotension frequently requires the administration of
catecholamine pressors. DESIGN: Retrospective analysis of existing data. SETTING:
The medical or surgical intensive care unit of Columbia-Presbyterian Medical
Center. PATIENTS: Three consecutive patients receiving milrinone and requiring
catecholamine pressors to maintain systolic arterial pressure of > or =90 mm Hg.
INTERVENTIONS: Vasopressin was administered to the three patients. MEASUREMENTS
AND MAIN RESULTS: Vasopressin (0.03-0.07 units/min) increased systolic arterial
pressure from 90+/-4.7 to 130+/-2.3 mm Hg while reducing the administration of
catecholamine pressors. CONCLUSIONS: Vasopressin at very low doses appears to be
an effective vasopressor for milrinone-induced hypotension.
PMID- 10667534
TI - What role does neutrophil apoptosis play in acute respiratory distress syndrome?
PMID- 10667535
TI - Use of immune globulin intravenous (human) to prevent infection in the multiple
trauma patient.
PMID- 10667536
TI - Science and surveys in the treatment of head injuries.
PMID- 10667537
TI - Outcomes of post-intensive care unit care: once more, the half-full/empty glass.
PMID- 10667538
TI - Prognostic systems in intensive care: how do you interpret an observed mortality
that is higher than expected?
PMID- 10667539
TI - Acute quadriplegia myopathy in the intensive care unit: time to look at a
mechanistic approach.
PMID- 10667540
TI - Upper gastrointestinal hemorrhage in the inpatient hospital setting: a different
beast?
PMID- 10667541
TI - Leukotriene B4, acute respiratory distress syndrome, and outcomes.
PMID- 10667542
TI - Are resuscitation fluids harmful?
PMID- 10667543
TI - Transport of the critically ill.
PMID- 10667544
TI - Ionized hypocalcemia during sepsis.
PMID- 10667545
TI - Outcomes research at the end of life.
PMID- 10667546
TI - Redox pairs, tissue hypoxia, organ dysfunction, and mortality.
PMID- 10667547
TI - Scoring systems for eclampsia.
PMID- 10667548
TI - Bioelectrical impedance monitoring: is this a bull market for electric utilities?
PMID- 10667549
TI - Quantifying the rancid, the rotten, and the rusty related to oxidant-mediated
molecular pathogenesis.
PMID- 10667550
TI - Does hypertonic burn resuscitation make a difference?
PMID- 10667551
TI - Naloxone and shock.
PMID- 10667552
TI - A complex role for nitric oxide in ischemic stroke.
PMID- 10667553
TI - Aseptic versus bacterial postoperative meningitis: cytokines as a distinguishing
marker.
PMID- 10667554
TI - Hemodynamic effects of high-frequency oscillatory ventilation: a little volume
goes a long way.
PMID- 10667555
TI - An outbreak of Ebola virus: lessons for everyday activities in the intensive care
unit.
PMID- 10667556
TI - Effects of intra-aortic balloon occlusion during cardiopulmonary resuscitation.
PMID- 10667557
TI - Use of animal models to test novel therapies in sepsis.
PMID- 10667558
TI - Gastric pH and intravenous ranitidine in critically ill children.
PMID- 10667559
TI - The relatives' place at resuscitation.
PMID- 10667560
TI - Regulation of angiogenesis via vascular endothelial growth factor receptors.
PMID- 10667561
TI - Malonyl-coenzyme-A is a potential mediator of cytotoxicity induced by fatty-acid
synthase inhibition in human breast cancer cells and xenografts.
AB - A biologically aggressive subset of human breast cancers and other malignancies
is characterized by elevated fatty-acid synthase (FAS) enzyme expression,
elevated fatty acid (FA) synthesis, and selective sensitivity to pharmacological
inhibition of FAS activity by cerulenin or the novel compound C75. In this study,
inhibition of FA synthesis at the physiologically regulated step of carboxylation
of acetyl-CoA to malonyl-CoA by 5-(tetradecyloxy)-2-furoic acid (TOFA) was not
cytotoxic to breast cancer cells in clonogenic assays. FAS inhibitors induced a
rapid increase in intracellular malonyl-CoA to several fold above control levels,
whereas TOFA reduced intracellular malonyl-CoA by 60%. Simultaneous exposure of
breast cancer cells to TOFA and an FAS inhibitor resulted in significantly
reduced cytotoxicity and apoptosis. Subcutaneous xenografts of MCF7 breast cancer
cells in nude mice treated with C75 showed FA synthesis inhibition, apoptosis,
and inhibition of tumor growth to less than 1/8 of control volumes, without
comparable toxicity in normal tissues. The data suggest that differences in
intermediary metabolism render tumor cells susceptible to toxic fluxes in malonyl
CoA, both in vitro and in vivo.
PMID- 10667562
TI - Redox regulation of glutathione S-transferase induction by benzyl isothiocyanate:
correlation of enzyme induction with the formation of reactive oxygen
intermediates.
AB - Here we report the molecular mechanism underlying the induction of glutathione S
transferase (GST) in rat liver epithelial RL34 cells treated with a cancer
chemopreventive isothiocyanate compound, benzylisothiocyanate (BITC). BITC was
found to significantly induce GST activity in RL34 cells. Northern and Western
blot analyses demonstrated that BITC specifically enhanced the production of the
class pi GST isozyme (GSTP1). Our studies demonstrated for the first time that
the addition of BITC to the cells resulted in an immediate increase in the
reactive oxygen intermediates (ROIs) detected by a fluorescence probe, 2',7'
dichlorofluorescin diacetate. The level of the ROIs in the cells treated with
BITC (10 microM) was approximately 50-fold higher than those in the control
cells. Furthermore, glutathione depletion by diethyl maleate significantly
enhanced BITC-induced ROI production and accelerated the BITC-induced elevation
of the GST activity, whereas pretreatment of the cells with glutathione inhibited
both the ROI production and GST induction. The structure-activity relationship of
the isothiocyanates also indicated that the ROI-producing activities closely
correlated with their GST-inducing potencies. Moreover, the GSTP1 enhancer I
containing region was found to be essential for induction of the GSTP1 gene by
intracellular ROI inducers such as BITC and diethyl maleate. These data suggest
the involvement of the redox regulation on the induction of GSTP1 by BITC.
PMID- 10667563
TI - Evidence that the epidermal targets of carcinogen action are found in the
interfollicular epidermis of infundibulum as well as in the hair follicles.
AB - Actively cycling, transit-amplifying cells and quiescent cells including stem
cells are found in the layer of the epidermis and hair follicles. To determine
the origin of skin tumors, we completely removed the interfollicular epidermis of
carcinogen-initiated mice by an abrasion technique known to leave the hair
follicles undisturbed. The interfollicular epidermis of the abraded mice quickly
regenerated from cells in the hair follicles, after which time tumor promotion
was begun. Mice in which the interfollicular epidermis had been removed developed
papillomas and carcinomas; however, the number of papillomas throughout 40 weeks
was half that of the unabraded mice. Carcinoma responses were not significantly
different in the abraded and unabraded groups. These results are consistent with
the hypothesis that the targets of tumor initiation are stem cells found in the
hair follicles and, to a lesser degree, in the interfollicular epidermis.
PMID- 10667564
TI - Vascular protection by chloroquine during brain tumor therapy with Tf-CRM107.
AB - Tf-CRM107 is a conjugate of transferrin and a point mutant of diphtheria toxin
that selectively kills cells expressing high levels of the transferrin receptor.
Tf-CRM107 has been infused intratumorally into patients with malignant brain
tumors. Although approximately half of the patients exhibit tumor responses,
patients receiving higher doses of Tf-CRM107 may develop magnetic resonance image
(MRI) evidence of toxicity indicative of small vessel thrombosis or petechial
hemorrhage. Consistent with these clinical results we found that intracerebral
injection of Tf-CRM107 into rats at total doses > or =0.025 microg causes brain
damage detectable by MRI and histology. To widen the therapeutic window of Tf
CRM107, we explored ways to prevent this damage to the vasculature. We reasoned
that the vasculature may be protected to a greater extent than tumor from Tf
CRM107 infused into brain parenchyma by i.v. injection of reagents with low blood
brain barrier permeability that block the toxicity of Tf-CRM107. Chloroquine, a
well-characterized antimalarial drug, blocks the toxicity of diphtheria toxin and
Tf-CRM107. Systemic administration of chloroquine blocked the toxicity of Tf
CRM107 infused intracerebrally in rats and changed the maximum tolerated dose of
Tf-CRM107 from 0.2 to 0.3 microg. Moreover, chloroquine treatment completely
blocked the brain damage detected by MRI caused by intracerebral infusion of 0.05
microg of Tf-CRM107. In nude mice bearing s.c. U251 gliomas, chloroquine
treatment had little effect on the antitumor efficacy of Tf-CRM107. Thus,
chloroquine treatment may be useful to reduce the toxicity of Tf-CRM107 for
normal brain without inhibiting antitumor efficacy and increase the therapeutic
window of Tf-CRM107 for brain tumor therapy.
PMID- 10667565
TI - Induction of uterine adenocarcinoma in CD-1 mice by catechol estrogens.
AB - Catechol estrogens may mediate estrogen-induced carcinogenesis because 4
hydroxyestradiol induces DNA damage and renal tumors in hamsters, and this
metabolite is formed in the kidney and estrogen target tissues by a specific
estrogen 4-hydroxylase. We examined the carcinogenic potential of catechol
estrogen in an experimental model previously reported to result in a high
incidence of uterine adenocarcinoma after neonatal exposure to
diethylstilbestrol. Outbred female CD-1 mice were treated with 2- or 4
hydroxyestradiol, 17beta-estradiol, or 17alpha-ethinyl estradiol on days 1-5 of
neonatal life (2 microg/pup/day) and sacrificed at 12 or 18 months of age. Mice
treated with 17beta-estradiol or 17a-ethinyl estradiol had a total uterine tumor
incidence of 7% or 43%, respectively. 2-Hydroxyestradiol induced tumors in 12% of
the mice, but 4-hydroxyestradiol was the most carcinogenic estrogen, with a 66%
incidence of uterine adenocarcinoma. Both 2- and 4-hydroxylated catechols were
estrogenic and increased uterine wet weights in these neonates. These data
demonstrate that both 2- and 4-hydroxyestradiol are carcinogenic metabolites. The
high tumor incidence induced by 4-hydroxyestradiol supports the postulated role
of this metabolite in hormone-associated cancers.
PMID- 10667566
TI - Nickel compounds are novel inhibitors of histone H4 acetylation.
AB - Environmental factors influence carcinogenesis by interfering with a variety of
cellular targets. Carcinogenic nickel compounds, although generally inactive in
most gene mutation assays, induce chromosomal damage in heterochromatic regions
and cause silencing of reporter genes when they are located near telomere or
heterochromatin in either yeast or mammalian cells. We studied the effects of
nickel on the lysine acetylation status of the NH2-terminal region of histone H4.
At nontoxic levels, nickel decreased the levels of histone H4 acetylation in vivo
in both yeast and mammalian cells, affecting only lysine 12 in mammalian cells
and all of the four lysine residues in yeast. In yeast, lysine 12 and 16 were
more greatly affected than lysine 5 and 8. Interestingly, a histidine Ni2+
anchoring site is found at position 18 from the NH2-terminal tail of H4. Nickel
was also found to inhibit the acetylation of H4 in vitro using purified
recombinant histone acetyltransferase. To our knowledge, this is the first agent
shown to decrease histone H4 acetylation at nontoxic levels.
PMID- 10667567
TI - Prognostic significance of cyclin E overexpression in resected non-small cell
lung cancer.
AB - Cyclin E plays a pivotal role in the regulation of G1-S transition and relates to
malignant transformation of the cells. However, the clinical significance of
cyclin E expression in patients with non-small cell lung cancer remains unknown.
We examined the expression of cyclin E in 242 resected non-small cell lung cancer
in pathological stages I-IIIa and analyzed its relation to clinicopathological
factors. Cylin E overexpressions were observed frequently in deeply invasive
tumors. Multivariate analysis revealed that complete resection, pathological
stage, and cyclin E expression were independent prognostic indicators. When
cyclin E and proliferating cell nuclear antigen are combined, the cases negative
for both had a significantly better prognosis than the other cases. We concluded
that cyclin E overexpression relates to deeply invasive tumors and is correlated
with poor prognosis. New therapeutic options may be provided by combination of
cyclin E expression and proliferating cell nuclear antigen overexpression.
PMID- 10667568
TI - Selective loss of estrogen receptor beta in malignant human colon.
AB - Epidemiological data suggest a protective effect for estrogen replacement therapy
on colon cancer. The estrogen receptor (ER) is required for the action of
estrogen. The ER-beta isoform is functionally similar to ER-alpha but has a
distinct pattern of expression and transcriptional response to selective estrogen
response modulators. Our goal was to investigate the presence of ER-alpha and ER
beta in normal and malignant colon tissue. Human colon cancer tissue and adjacent
normal colon tissue were harvested from five male and six female patients
undergoing segmental colon resection for colon cancer. Western blot analysis
revealed very low levels of ER-alpha protein in tumor and normal colon tissue. In
both male and female patients, malignant colon tissue showed a selective loss of
ER-beta protein expression when compared to normal colon tissue in the same
patient. Semiquantitative reverse transcription-PCR revealed no difference in ER
beta mRNA levels between normal and malignant colon tissue. Malignant
transformation of the colon is associated with a marked diminution of ER-beta
protein expression, possibly through a posttranscriptional mechanism.
PMID- 10667569
TI - Effects of cyclin D1 polymorphism on age of onset of hereditary nonpolyposis
colorectal cancer.
AB - A common polymorphism in the cyclin D1 gene enhances the gene's alternate
splicing. The alternatively spliced product encodes an altered protein that does
not contain sequences involved in the turnover of the protein. We found that
hereditary nonpolyposis colorectal carcinoma patients who were homozygous or
heterozygous for the mutant allele developed colorectal cancer an average of 11
years earlier than patients who were homozygous for the normal alleles. This is
the first report indicating that the cyclin D1 polymorphism influences age of
onset of cancer. Because cyclin D1 plays an important role in the G1 to S phase
transition of the cell cycle, our findings suggest that cells with the mutant
allele accumulate mutations as a result of defective mismatch repair and may also
bypass the G1-S checkpoint of the cell cycle more easily than in cells not
carrying the polymorphism. The polymorphism has a dominant phenotype.
PMID- 10667571
TI - The HRAS1 minisatellite locus and risk of ovarian cancer.
AB - Approximately 10% of ovarian cancers are due to mutations in highly penetrant
inherited cancer susceptibility genes. The highly polymorphic HRAS1 minisatellite
locus, located just downstream from the proto-oncogene H-ras-1 on chromosome 11p,
consists of four common progenitor alleles and several dozen rare alleles, which
apparently derive from mutations of the progenitors. Mutant alleles of this locus
represent a major risk factor for cancers of the breast, colorectum, and bladder,
and it was found that BRCAI mutation carriers with at least one rare HRAS1 allele
have a greater risk of ovarian cancer than BRCA1 carriers with only common HRAS1
alleles. There are no conclusive studies of HRAS1 alleles in sporadic epithelial
ovarian cancer. A case-control study of HRAS1 alleles was performed on DNA from
136 Caucasian patients with ovarian cancer and 108 cancer-free controls using
conventional (Southern blot) and PCR-based methods to determine the frequency of
rare HRAS1 alleles. Odds ratios (ORs) were estimated using unconditional logistic
regression methods. A single degree of freedom test was used to assess the
significance of linear trend across categories of increasing exposure. A
statistically significant association between rare HRAS1 alleles and risk of
ovarian cancer was observed [OR, 1.70; 95% confidence interval (CI), 1.03-2.80; P
= 0.04]. Having only one rare allele was associated with a relative risk of 1.66
(95% CI, 0.91-3.01), whereas having two rare alleles increased the relative risk
to 2.86 (95% CI, 0.75-10.94; trend P = 0.03). Analysis of HRAS1 allele types by
the age of the case at diagnosis revealed that younger cases (<45 years) had a
borderline statistically significant increased association with rare HRAS1
alleles compared to older cases (> or = 0 years; OR, 1.89; 95% CI, 0.90-3.98; P =
0.09). Rare HRAS1 alleles contribute to ovarian cancer predisposition in the
general population. Thus, the HRAS1-variable number of tandem repeats locus may
function as a modifier of ovarian cancer risk in both sporadic and hereditary
ovarian cancer.
PMID- 10667570
TI - Genetic vaccination with "self" tyrosinase-related protein 2 causes melanoma
eradication but not vitiligo.
AB - "Self" melanocyte differentiation antigens are potential targets for specific
melanoma immunotherapy. Vaccination against murine tyrosinase-related protein
(TRP)-1/gp75 was shown recently to cause melanoma rejection, which was
accompanied by autoimmune skin depigmentation (vitiligo). To further explore the
linkage between immunotherapy and autoimmunity, we studied the response to
vaccination with a related antigen, TRP-2. i.m. inoculation of plasmid DNA
encoding murine trp-2 elicited antigen-specific CTLs that recognized the B16
mouse melanoma and protected the mice from challenge with tumor cells.
Furthermore, mice bearing established s.c. B16 melanomas rejected the tumor upon
vaccination with a recombinant vaccinia virus encoding trp-2. Depletion
experiments showed that CD8+ lymphocytes and natural killer cells were crucial
for the antitumor activity of the trp-2-encoding vaccines. Mice that rejected the
tumor did not develop generalized vitiligo, indicating that protective immunity
can be achieved in the absence of widespread autoimmune aggression.
PMID- 10667573
TI - Prostate mutations in rats induced by the suspected human carcinogen 2-amino-1
methyl-6-phenylimidazo[4,5-b]pyridine.
AB - Male lacl transgenic rats were fed a diet containing 200 ppm of 2-amino-1-methyl
6-phenylimidazo[4,5-b]pyridine (PhIP), a heterocyclic amine present in cooked
meats. PhIP was found to be a powerful prostate mutagen. After 61 days of
treatment, the lacl mutant frequency was 71 x 10(-5), >20-fold higher than the
spontaneous mutant frequency of 3.2 x 10(-5). The predominant PhIP-induced
mutations were G:C->T:A transversions and deletions of G:C bp. The results
directly link PhIP-induced mutations with the earlier observation of PhIP-induced
prostate cancer in rats and suggest that exposure to dietary PhIP could be a risk
factor in the incidence of human prostate cancer.
PMID- 10667572
TI - Mechanism for inactivation of the KIP family cyclin-dependent kinase inhibitor
genes in gastric cancer cells.
AB - The mechanism for inactivation of the KIP family cyclin-dependent kinase
inhibitor (CDKI) genes, the p21, p27, and p57 genes, in gastric cancer cells was
tested by treating the cells with either the DNA demethylation agent, 5-aza-2'
deoxycytidine or the histone deacetylase inhibitor, n-butyric acid or
trichostatin A. RNA expression of the gene was determined by reverse
transcription PCR. The p21 gene was activated only by histone deacetylase
inhibitor. The p57 gene was activated by histone deacetylase inhibitors in all of
the gastric cancer cell lines and by 5-aza-2'-deoxycytidine in five of eight
gastric cell lines. However, the p27 gene was not inactivated in gastric cancer
cell lines. The methylation status of the promoter of the p21 and p57 genes was
also tested by digestion with the methylation-sensitive restriction enzymes and a
subsequent PCR. The promoter of the p21 gene has no methylation. The promoter of
the p57 gene is, however, methylated in five of eight gastric cancer cell lines
as expected from the result of the treatment with 5-aza-2'-deoxycytidine.
Formation of the inactive chromatin through histone deacetylation seems to be the
general mechanism for inactivation of both the p21 and the p57 genes in gastric
cancer cells. Hypermethylation of promoter region seems to be an alternative
pathway for inactivation of the p57 gene.
PMID- 10667574
TI - The angiogenic factor interleukin 8 is induced in non-small cell lung
cancer/pulmonary fibroblast cocultures.
AB - The interactions between tumor cells and surrounding stromal elements may promote
the release of angiogenic factors. Although interleukin 8 (IL-8) is a major
angiogenic factor in non-small cell lung cancer (NSCLC), the stromal contribution
to IL-8 expression in primary NSCLC remains to be defined. To elucidate the role
of stromal elements in NSCLC IL-8 production, normal pulmonary fibroblasts were
cocultured with six representative NSCLC lines in direct and transwell assays. IL
8 transcripts and protein were consistently induced in fibroblasts and a subset
of NSCLCs as a consequence of tumor/stromal coculture. In these cocultures, IL-8
was induced by IL-1alpha and an additional, as yet unidentified, soluble factor.
These data underscore the importance of tumor/stromal interaction in the
production of angiogenic peptides such as IL-8 in NSCLC.
PMID- 10667575
TI - Tamoxifen chemoprevention of a hormone-independent tumor in the proto-neu
transgenic mice model.
AB - We evaluated the effect of tamoxifen (TAM) on tumor development in proto-neu
transgenic mice that spontaneously develop mammary carcinomas overexpressing the
neu protein. These mammary carcinomas are hormone independent because
superimposable growth of transplants was observed in females and males. Virgin
transgenic mice treated with TAM from 24 weeks of age, ie., when subclinical
mammary tumors are already present, showed a slightly accelerated tumor
development. In contrast, transgenic mice treated with TAM starting at 12 weeks
of age, when subclinical tumors are not yet present, showed a 50% reduction of
tumor incidence. Light microscopy analysis of the mammary gland of these mice
revealed an apparently normal ductal branching but a complete regression of the
acini. In conclusion, TAM can prevent the occurrence of hormone-independent
breast carcinoma if given early enough to inhibit normal cells.
PMID- 10667576
TI - Heregulin induces expression, DNA binding activity, and transactivating functions
of basic leucine zipper activating transcription factor 4.
AB - Heregulin beta1 (HRG), a combinatorial ligand for human epidermal growth factor
receptor 3 and human epidermal growth factor receptor 4 receptors, is a
regulatory secretory polypeptide with distinct biological effects such as growth
stimulation, differentiation, invasiveness, and migration in breast cancer cells.
The mechanism underlying the diverse functions of HRG is not well established,
but it is believed to be dependent on the induced changes in expression of
specific cellular gene products, their modification, or both. The binding of
basic leucine zipper transcription factors to the cAMP response element is known
to activate a variety of gene products with a role or roles in growth regulation.
In the studies presented here, we identified basic leucine zipper activating
transcription factor (ATF) 4 as one of the HRG-inducible gene product. We
demonstrated that HRG stimulation of human cancer cells induces expression of
ATF4 mRNA and protein, ATF4 DNA binding activity, and ATF4 transactivating
function. Consistent with its role as a transcriptional activator, HRG-stimulated
ATF4 protein stimulated the transcription from an artificial promoter with three
tandem ATF sites or from a naturally occurring promoter with ATF4 sites such as E
selectin. We also demonstrated a preferential role of the HRG-stimulated mitogen
activated protein kinase pathway, but not the phosphatidylinositol 3'-kinase
pathway, in supporting the observed increase in ATF4 DNA binding activity and
transcription from E-selectin promoter in HRG-stimulated cells. Because ATF4
binding sites are present in a variety of growth-regulating cellular genes, these
findings suggest that the stimulation of ATF4 expression and its transactivating
functions may constitute an important mechanism of HRG-mediated regulation of
putative genes with diversified functions. The present study is the first
demonstration of regulation of expression and transactivation ability of ATF4 by
any polypeptide growth factor.
PMID- 10667577
TI - Protein phosphorylation is a regulatory mechanism for O6-alkylguanine-DNA
alkyltransferase in human brain tumor cells.
AB - The biochemical regulation of human O6-alkylguanine-DNA alkyltransferase (AGT),
which determines the susceptibility of normal tissues to methylating carcinogens
and resistance of tumor cells to many alkylating agents, is poorly understood. We
investigated the regulation of AGT by protein phosphorylation in a human
medulloblastoma cell line. Incubation of cell extracts with [gamma-32P]ATP
resulted in Mg(2+)-dependent phosphorylation of the endogenous AGT.
Immunoprecipitation after exposure of the cells to 32P-labeled inorganic
phosphate showed that AGT exists as a phosphoprotein under physiological
conditions. Western analysis and chemical stability studies showed the AGT
protein to be phosphorylated at tyrosine, threonine, and serine residues.
Purified protein kinase A (PKA), casein kinase II (CK II), and protein kinase C
(PKC) phosphorylated the recombinant AGT protein with a stoichiometry of 0.15,
0.28, and 0.44 (mol phosphate incorporated/mol protein), respectively. Residual
phosphorylation of the endogenous AGT by the PKs present in cell homogenates and
phosphorylation of the recombinant AGT by purified serine/threonine kinases, PKA,
PKC, and CK II reduced AGT activity by 30-65%. Conversely, dephosphorylation of
cell extracts by alkaline phosphatases stimulated AGT activity. We also
identified consensus phosphorylation motifs for many cellular kinases, including
PKA and CK II in the AGT protein. These data provide the first and conclusive
evidence of AGT phosphorylation and suggest that reversible phosphorylation may
control the activity of this therapeutically important DNA repair protein in
human normal and cancer cells.
PMID- 10667578
TI - Nuclear matrix proteins associated with DNA in situ in hormone-dependent and
hormone-independent human breast cancer cell lines.
AB - The nuclear matrix is a dynamic RNA-protein complex that organizes chromatin and
regulates nuclear DNA metabolism. Nuclear matrix proteins informative in the
diagnosis of cancer have been identified. Here, the nuclear matrix breast cancer
proteins (NMBCs) cross-linked to nuclear DNA in situ with cisplatin in human
breast cancer cell lines were analyzed by two-dimensional gel electrophoresis. We
identified NMBCs that were differentially associated with nuclear DNA of hormone
dependent and -independent breast cancer cell lines. Three DNA cross-linked NMBCs
were found to be exclusive to estrogen receptor-positive, hormone-dependent
breast cancer cells, whereas two NMBCs were observed only in estrogen receptor
negative, hormone-independent breast cancer cells. Changes in these NMBCs were
observed when hormone-dependent breast cancer cells became hormone independent.
Furthermore, we show that the intermediate filament protein vimentin is
associated with the nuclear DNA of MDA-MB-231 breast cancer cells, an estrogen
receptor-negative, hormone-independent breast cancer cell line with high
metastatic potential. These nuclear matrix DNA-binding proteins may play
important roles in breast tumorigenesis.
PMID- 10667579
TI - Chemoprevention of colon cancer by specific cyclooxygenase-2 inhibitor,
celecoxib, administered during different stages of carcinogenesis.
AB - Epidemiological observations and laboratory research have suggested that
nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of colon cancer and
that the inhibition of colon carcinogenesis by NSAIDs is mediated through the
modulation of prostaglandin production by rate-limiting enzymes known as
cyclooxygenases (COXs). Because traditional NSAIDs inhibit both COX-1 and COX-2,
these drugs induce side effects, such as gastrointestinal ulceration and renal
toxicity, through the inhibition of the constitutive COX-1. Overexpression of COX
2 has been observed in colon tumors; therefore, specific inhibitors of COX-2
could serve as chemopreventive agents. Our previous study has shown that
celecoxib, an inhibitor of COX-2, while sparing COX-1, inhibited azoxymethane
(AOM)-induced colon tumorigenesis when administered during both initiation and
postinitiation stages, ie., celecoxib administered continuously before, during,
and after carcinogen treatment. This study examined the dose-response effect of
celecoxib when administered during the initiation and postinitiation stages. In
addition, the chemopreventive effects of high-dose celecoxib administered during
the promotion/progression stage of colon carcinogenesis, ie., continuous
celecoxib administration beginning 14 weeks after the carcinogen treatment, was
determined in male F344 rats. We also measured the steady-state levels of
celecoxib in the plasma of animals given this inhibitor. Groups of 5-week-old
male F344 rats were fed either a control diet or experimental diets containing
500, 1000, or 1500 ppm celecoxib. At 7 and 8 weeks of age, rats scheduled for
carcinogen treatment were injected s.c. with AOM at a dose rate of 15 mg/kg body
weight/week. Groups of animals destined for the promotion/ progression study and
initially receiving the control diet were switched to a diet containing 1500 ppm
celecoxib beginning 14 weeks after the second AOM treatment. All rats remained on
their respective dietary regimens until the termination of the study, ie., 52
weeks, and were then sacrificed. Colon tumors were evaluated histopathologically.
Administration of 500, 1000, or 1500 ppm celecoxib during the initiation and
postinitiation stages significantly inhibited the incidence (P < 0.01 to P <
0.0001) as well as the multiplicity (P < 0.01 to P < 0.0001) of adenocarcinomas
of the colon in a dose-dependent manner. Importantly, administration of 1500 ppm
celecoxib during the promotion/progression stage also significantly suppressed
the incidence and multiplicity of adenocarcinomas of the colon (P < 0.01). Also,
administration of celecoxib to the rats during the initiation and postinitiation
periods and throughout the promotion/progression stage strongly suppressed colon
tumor volume (P < 0.0002 to P < 0.001). The steady-state plasma concentration of
celecoxib increases somewhat with the dose. Thus, in this model system, the
chemopreventive efficacy of celecoxib is dose-dependent when this COX-2 inhibitor
is administered during the initiation and postinitiation periods. This study
provides the first evidence that celecoxib is also very effective when it is
given during the promotion/progression stage of colon carcinogenesis, indicating
that the chemopreventive efficacy is achieved during the later stages of colon
tumor development. This suggests that celecoxib may potentially be an effective
chemopreventive agent for the secondary prevention of colon cancer in patients
with familial adenomatous polyposis and sporadic polyps.
PMID- 10667580
TI - Separating favorable from unfavorable prognostic markers in breast cancer: the
role of E-cadherin.
AB - Distant metastases are the major cause of morbidity and mortality in women with
breast cancer. The ability to predict the metastatic proclivity is essential in
choosing the optimal treatment. Tumor size and grade, which are frequently used
markers in node-negative breast cancer patients, are inadequate markers for
prognosis and individualized treatment design. The steps in metastatic
progression include angiogenesis, invasion, and changes in adhesion
characteristics. We developed a strategy for choosing biomarkers representing
these steps in malignant progression to identify patients with occult metastases
who will need chemotherapy and spare those women whose tumors have not developed
the capacity to spread. To evaluate the added significance of E-cadherin to that
of nm23-H1 and angiogenesis in determining metastatic proclivity, we used
archival material from 168 node-negative breast cancer patients who were treated
with mastectomy without any adjuvant chemotherapy or hormone therapy.
Immunohistochemistry was used to detect E-cadherin and nm23-H1 expression,
whereas angiogenesis was determined by microvessel count (MVC) after
immunohistochemical staining. The median follow-up is 14 years. We found that E
cadherin is better in identifying the poor prognosis patients. The 14-year
disease-free survival (DFS) is 84%, 80%, and 56% in patients with high,
intermediate, and low E-cadherin. The worst prognosis group using nm23-H1 and MVC
as biomarkers has a 14-year DFS of 62%. In this group, if E-cadherin is low, the
14-year DFS is further decreased to 44%. Nm23-H1 and MVC are better in
identifying the good prognosis patients. The long-term DFS is >90% if MVC is low
or if nm23-H1 is high. Multivariate analysis shows that E-cadherin, nm23-H1, and
MVC are more significant prognostic biomarkers than tumor size or grade. Loss of
E-cadherin appears to be a latter step in the metastatic progression compared to
angiogenesis and the loss of nm23-H1 expression.
PMID- 10667581
TI - Association of vitamin D receptor gene polymorphism with prostate cancer and
benign prostatic hyperplasia in a Japanese population.
AB - Recent studies have suggested that vitamin D is an important determinant of
prostate cancer risk and inherited polymorphisms in the 3'-untranslated region
(3'UTR) of the vitamin D receptor (VDR) gene are associated with the risk and
progression of prostate cancer. This study was conducted to explore the
association of VDR gene polymorphisms with prostate cancer risk in Japanese men
who are considered to be much less influenced by environmental risk factors for
prostate cancer. We studied 222 prostate cancer patients, 209 benign prostatic
hyperplasia (BPH) patients, 128 male controls who were over 60 years old and
without any evidence of prostate cancer or BPH, and 198 female controls. A PCR
RFLP method was used to determine three VDR gene polymorphisms in the 3'UTR
characterized by restriction enzymes BsmI, ApaI and TaqI. In the BsmI
polymorphism, heterozygosity or homozygosity for the absence of the BsmI
restriction site was associated with one-third the risk of prostate cancer (P <
0.0001; odds ratio, 3.31; 95% confidence interval, 2.05-5.32) and with one-half
the risk of BPH (P < 0.005; odds ratio, 2.07; 95% confidence interval, 1.33-3.22)
compared with the male controls. The TaqI and ApaI polymorphisms did not show any
significant association with either prostate cancer or BPH. The results indicate
that the BsmI polymorphism in the VDR gene plays a significant role in protection
against prostate cancer and BPH. Because of the racial difference in the strength
of the linkage disequilibrium between the three polymorphisms, additional studies
are required to apply the present results to other racial-ethnic groups.
PMID- 10667582
TI - Anti-invasive, antitumorigenic, and antimetastatic activities of the PHSCN
sequence in prostate carcinoma.
AB - Using naturally serum-free SU-ECM basement membranes as invasion substrates
showed that plasma fibronectin was necessary to stimulate invasion by DU 145
human and metastatic MATLyLu (MLL) rat prostate carcinoma cells. This activity
mapped to the PHSRN sequence, which induced invasion through alpha5beta1
integrin. PHSCN, a competitive inhibitor, blocked both PHSRN- and serum-induced
invasion. Acetylated, amidated PHSCN (Ac-PHSCN-NH2) was 30-fold more potent;
however, Ac-HSPNC-NH2 was inactive. Rats receiving injections s.c. with 100,000
MLL cells were treated systemically by i.v. injection three times weekly with 1
mg of either Ac-PHSCN-NH2 or Ac-HSPNC-NH2 beginning 24 h later, three times
weekly with 1 mg of Ac-PHSCN-NH2 beginning only after surgery to remove large (2
cm) MLL tumors, or were left untreated. MLL tumors grew rapidly in Ac-HSPNC-NH2
treated and in untreated rats. MLL tumor growth in rats treated with Ac-PHSCN-NH2
beginning 1 day after MLL cell injection was reduced by 99.9% during the first 16
days of treatment, although subsequent tumor growth occurred. MLL tumor
cryosections immunostained with anti-PECAM-1 showed that Ac-PHSCN-NH2 inhibited
neovascularization by 12-fold during this time. Whether initiated after MLL cell
injection or only after MLL tumor removal, Ac-PHSCN-NH2 treatment reduced the
numbers of MLL lung colonies and micrometastases by 40- to >100-fold, whereas Ac
HSPNC-NH2 was inactive. Thus, Ac-PHSCN-NH2 may be a potent antitumorigenic and
antimetastatic agent for postsurgical use prior to extensive metastasis.
PMID- 10667583
TI - Radiation-induced apoptosis of endothelial cells in the murine central nervous
system: protection by fibroblast growth factor and sphingomyelinase deficiency.
AB - Injury to the central nervous system (CNS) by ionizing radiation may be a
consequence of damage to the vascular endothelium. Recent studies showed that
radiation-induced apoptosis of endothelial cells in vitro and in the lung in vivo
is mediated by the lipid second messenger ceramide via activation of acid
sphingomyelinase (ASM). This apoptotic response to radiation can be inhibited by
basic fibroblast growth factor or by genetic mutation of ASM. In the CNS, single
dose radiation has been shown to result in a 15% loss of endothelial cells within
24 h, but whether or not this loss is associated with apoptosis remains unknown.
In the present studies, dose- and time-dependent induction of apoptosis was
observed in the C57BL/6 mouse CNS. Apoptosis was quantified by terminal
deoxynucleotidyl transferase-mediated nick end labeling, and specific endothelial
apoptosis was determined by histochemical double labeling with terminal
deoxynucleotidyl transferase-mediated nick end labeling and Lycopersicon
esculentum lectin. Beginning at 4 h after single-dose radiation, apoptosis was
ongoing for 24 h and peaked at 12 h at an incidence of 0.7-1.4% of the total
cells in spinal cord sections. Up to 20% of the apoptotic cells were endothelial.
This effect was also seen in multiple regions of the brain (medulla, pons, and
hippocampus). A significant reduction of radiation-induced apoptosis was observed
after i.v. basic fibroblast growth factor treatment (0.45-4.5 microg/mouse).
Identical results were noted in C3H/HeJ mice. Furthermore, irradiated ASM
knockout mice displayed as much as a 70% reduction in endothelial apoptosis. This
study demonstrates that ionizing radiation induces early endothelial cell
apoptosis throughout the CNS. These data are consistent with recent evidence
linking radiation-induced stress with ceramide and suggest approaches to modify
the apoptotic response in control of radiation toxicity in the CNS.
PMID- 10667584
TI - Differential toxicities of anticancer agents among DNA repair and checkpoint
mutants of Saccharomyces cerevisiae.
AB - Most cytotoxic anticancer agents damage DNA directly, interfere with DNA
metabolism or chromosome segregation, and are particularly toxic in dividing
cells. Although a considerable amount of information on the mechanisms of action
of these agents is available, the molecular bases for selective tumor cell
killing by chemotherapy are largely unknown. Many genetic alterations found in
sporadic and hereditary cancers affect functions in DNA repair and cell cycle
control and result in sensitivity to DNA damaging agents. We have therefore set
out to determine the effects of these cancer mutations on sensitivity or
resistance to various chemotherapeutic agents. Because most of the affected genes
are well conserved among eukaryotes, we have carried out a comprehensive analysis
of a panel of isogenic yeast strains, each defective in a particular DNA repair
or cell cycle checkpoint function, for sensitivity to the Food and Drug
Administration-approved cytotoxic anticancer agents. Widely different toxicity
profiles were observed for 23 agents and X-rays, indicating that the type of DNA
repair and cell cycle checkpoint mutations in individual tumors could strongly
influence the outcome of a particular chemotherapeutic regimen.
PMID- 10667585
TI - Prostate-specific antigen promoter/enhancer driven gene therapy for prostate
cancer: construction and testing of a tissue-specific adenovirus vector.
AB - A range of luciferase reporter vectors was constructed, incorporating 5'-flanking
sequences from the prostate-specific antigen (PSA), human glandular kallikrein 2
(hKLK2), and cytomegalovirus (CMV) promoters for expression control. Tissue
specificity was evaluated in the PSA-positive line LNCaP and PSA-negative cells
from different tissues of origin (CoLo320, DG75, EJ, A2780, and Jurkat). The
minimal 628-bp PSA and hKLK2 promoters showed only low-level expression in either
PSA-positive or PSA-negative cells and showed no increase with the addition of
androgen. Tandem duplication of the PSA promoter slightly increased expression in
PSA-positive LNCaP cells. The addition of CMV enhancer sequences upstream of a
single PSA or hKLK2 promoter substantially but nonspecifically increased
luciferase expression in all cell lines tested. However, placing a 1455-bp PSA
enhancer sequence upstream of either the PSA or hKLK2 promoters increased
expression 20-fold in the PSA-positive cell line LNCaP but not in the PSA
negative lines. Tandem duplication of the PSA enhancer increased expression to
approximately 50-fold higher than either promoter alone while retaining tissue
specific control. The level of expression was reduced by the addition of a third
copy of the PSA enhancer. Expression from all enhancer constructs was increased
100-fold above basal levels when induced with the androgen dihydrotestosterone,
with the PSA-based constructs consistently exhibiting roughly twice the level of
expression of the hKLK2-based constructs at all androgen concentrations.
Adenovirus vectors were produced in which either enhanced green fluorescent
protein or nitroreductase could be expressed from the optimized PSA double
enhancer-promoter construct and evaluated in LNCaP cells and the bladder-derived
line EJ. Control vectors with the CMV promoter gave good levels of expression in
both cell lines, whereas the PSA constructs only produced detectable levels of
protein in the LNCaP cells as assessed by fluorescence of enhanced green
fluorescent protein or by Western blotting of nitroreductase. LNCaP but not EJ
cells were selectively sensitized to the prodrug CB1954 following infection with
Ad-PSA(EEP)-NR. The PSA-based nitroreductase virus produced comparable amounts of
nitroreductase and sensitization to CB1954 approaching that of the CMV-driven
virus. Plasmid and adenovirus constructs combining PSA enhancer and promoter
sequences demonstrate selective expression of linked genes in PSA-positive cells.
The expression is induced by androgen and gives therapeutically relevant levels
of effector proteins.
PMID- 10667586
TI - The geldanamycins are potent inhibitors of the hepatocyte growth factor/scatter
factor-met-urokinase plasminogen activator-plasmin proteolytic network.
AB - The Met receptor tyrosine kinase and its ligand, hepatocyte growth factor/scatter
factor (HGF/SF), have been implicated in human tumor development and metastasis.
HGF/SF induces the expression of urokinase plasminogen activator (uPA) and the
uPA receptor (uPAR), important mediators of cell invasion and metastasis. We have
developed a cell-based assay to screen for inhibitors of this signaling system
using the induction of endogenous uPA and uPAR and the subsequent conversion of
plasminogen to plasmin as the biological end point. Assay validation was
established using a neutralizing antiserum to HGF/SF and a uPA inhibitor (B428),
as well as inhibitors of the MKK-MAPK1/2 pathway, shown previously to be
important in the induction of uPA and uPAR. Using this assay, we found several
classes of molecules that exhibited inhibition of HGF/SF-dependent plasmin
activation. However, we discovered that certain members of the geldanamycin
family of anisamycin antibiotics are potent inhibitors of HGF/SF-mediated plasmin
activation, displaying inhibitory properties at femtomolar concentrations and
nine orders of magnitude below their growth inhibitory concentrations. At
nanomolar concentrations, the geldanamycins down-regulate Met protein expression,
inhibit HGF/SF-mediated cell motility and invasion, and also revert the phenotype
of both autocrine HGF/SF-Met transformed cells as well as those transformed by
Met proteins with activating mutations. Thus, the geldanamycins may have
important therapeutic potential for the treatment of cancers in which Met
activity contributes to the invasive/metastatic phenotype.
PMID- 10667587
TI - Effective elimination of lung metastases induced by tumor cells treated with
hydrostatic pressure and N-acetyl-L-cysteine.
AB - In previous studies, we have demonstrated that application of high hydrostatic
pressure (P) to tumor cells in the presence of a slow-reacting membrane
impermeable cross-linker (CL), 2'-3'-adenosine dialdehyde, can rearrange cell
surface proteins into immunogenic clusters. Here, we present evidence indicating
that subsequent reduction of surface protein disulfides with N-acetyl-L-cysteine
(NAC) further augments the immunogenic potential of PCL-modified tumor cells both
in vitro and in vivo. Immunotherapy with PCL+NAC-modified 3LL-D122 Lewis lung
carcinoma cells plus i.v. delivery of NAC in mice bearing established lung
metastases provoked an antitumor response capable of eradicating the metastatic
nodules as demonstrated by restoration of normal lung weight and histology. In
addition, immunization with PCL+NAC-modified tumor cells gave rise to a strong
delayed-type hypersensitivity recall response against parental D122 cells. We
propose that this novel two-prong strategy, based on local immunization with
autologous PCL+NAC-modified tumor cells and systemic boosting with NAC, could
provide a practical, effective immunotherapeutic regimen for the treatment of
human cancer.
PMID- 10667588
TI - Ability of systemic interleukin-12 to hamper progressive stages of mammary
carcinogenesis in HER2/neu transgenic mice.
AB - Previous studies in mice have shown that chronic administration of recombinant
interleukin-12 (IL-12) hampers the progression of both chemical- and oncogene
dependent carcinogenesis. This suggests that a new preventive strategy may be
envisaged for individuals with a genetic risk of cancer or carrying preneoplastic
lesions. Starting at progressive stages of mammary carcinogenesis, female BALB/c
and FVB mice carrying the activated rat HER2/neu oncogene (BALB-neuT) or the
proto-oncogene (FVB-neuN) under the mouse mammary tumor virus promoter received
multiple 5-day courses of different doses of IL-12. The times of tumor
appearance, multiplicity, and histopathological features of the neoplastic
lesions were evaluated. In both BALB-neuT and FVB-neuN mice, 5-day i.p. courses
of 50/100 ng of IL-12/day inhibited mammary carcinogenesis when they coincided
with the progression of early preneoplastic lesions. Inhibition appears to depend
primarily on the ability of IL-12 to interfere with early tumor angiogenesis.
Later treatments are much less effective, and daily doses of 10 and 2 ng are
useless. The efficacy of early IL-12 courses suggests that they could be used to
prevent mammary tumors in individuals at risk, whereas their lower efficacy in
later stages of carcinogenesis and the dose range required pose some constraints
on their use in the management of overt preneoplastic lesions. Precise
understanding of tumor progression means that effective treatments can be
commenced relatively late in the life of individuals at risk and that no lifetime
administration is required.
PMID- 10667589
TI - Use of fluorogenic histocompatibility leukocyte antigen-A*0201/HPV 16 E7 peptide
complexes to isolate rare human cytotoxic T-lymphocyte-recognizing endogenous
human papillomavirus antigens.
AB - Cervical cancer (CaCx) is the second most common female malignancy worldwide and
remains a clinical problem despite improvements in early detection and therapy.
CaCx and preinvasive cervical intraepithelial neoplasia (CIN3) are strongly
associated with infection by human papillomavirus (HPV), particularly types 16
and 18. Two nonstructural viral proteins, E6 and E7, are constitutively expressed
in cervical tumors and are crucial for the maintenance of the transformed
phenotype. These proteins thus provide attractive targets for immunotherapy of
CaCx mediated by CD8+ CTLs. However, reliable detection and generation of HPV
specific CTLs in humans has been difficult. Recently, soluble fluorogenic MHC
peptide complexes (tetramers) have greatly increased the sensitivity of antiviral
and antitumor CTL detection. To examine the feasibility of this approach for
detecting HPV-specific CTLs, we constructed a tetramer consisting of HLA-A*0201
and the best studied HPV CTL peptide epitope, HPV 16 E711-20. Between 2 and 12%
of short-term HPV 16 E711-2 CTL lines derived from CaCx patients stained highly
with the tetramer. Direct ex vivo staining of peripheral blood mononuclear cells
revealed CD8+ tetramer+ high cells at low frequencies in both CIN3 patients (1 of
1,260 to 1 of 19,073) and normal controls (1 of 1,855 to 1 of 42,004). However,
short-term in vitro stimulation with the HPV 16 E711-20 peptide expanded
CD8+tetramer+ cells to a greater extent in the peripheral blood mononuclear cells
from CIN3 patients. Furthermore, the tetramer provided a powerful tool to isolate
polyclonal and clonal peptide-specific CTLs from an established HPV 16 E7,11-20
specific CTL line. These purified CTLs were able to lyse both peptide-pulsed
targets and targets expressing endogenously processed HPV antigens. This tetramer
may therefore be useful for selecting rare high-affinity HPV-specific CTLs for
the immunotherapy of CaCx.
PMID- 10667590
TI - Mutations in the retinoblastoma-related gene RB2/p130 in lung tumors and
suppression of tumor growth in vivo by retrovirus-mediated gene transfer.
AB - The retinoblastoma (Rb) family consists of the tumor suppressor pRb/p105 and
related proteins p107 and pRb2/p130. Recent immunohistochemical studies of the
retinoblastoma family of proteins in 235 specimens of lung cancer show the
tightest inverse association between the histological grading in the most
aggressive tumor types and pRb2/p130. This led us to study a panel of human lung
cancers for mutations in the RB2/p130 gene. Mutations in the Rb-related gene
RB2/p130 were detected in 11 of 14 (78.5%) primary lung tumors by single-strand
conformation polymorphism and sequence analysis. A Moloney leukemia virus-based
retroviral system was set up, and a comparable viral concentration of 1 x 10(7)
infectious units/ml was obtained. Retrovirus-mediated delivery of wild-type
RB2/p130 to the lung tumor cell line H23 potently inhibited tumorigenesis in
vitro and in vivo, as shown by the dramatic growth arrest observed in a colony
assay and the suppression of anchorage-independent growth potential and tumor
formation in nude mice. The tumors transduced with the RB2/p130 retrovirus
diminished in size after a single injection, and a 12-fold reduction in tumor
growth after RB2/p130 transduction compared with the Pac-transduced tumors (92%
reduction, P = 0.003) and lacZ-transduced tumors (93% reduction, P < 0.001) was
found to be statistically significant. These findings provide the missing
confirmation that RB2/p130 is a "bona fide" tumor suppressor gene and strengthen
the hypothesis that it may be a candidate for cancer gene therapy for lung
cancer.
PMID- 10667591
TI - Genetic alterations disrupting the nuclear localization of the retinoblastoma
related gene RB2/p130 in human tumor cell lines and primary tumors.
AB - The prototypic tumor suppressor gene, the retinoblastoma gene (RB/ p105), is
mutated in a variety of human tumors. However, to date, mutational data on
retinoblastoma family members p107 and RB2/p130 in tumors is lacking. We studied
the expression of pRb2/p130 by immunocytochemistry and Western blot analysis in a
panel of human osteosarcoma and lymphoid cell lines. Only the lymphoid cell lines
showed an abnormal cytoplasmic localization of pRb2/p130, suggesting possible
alterations within the region of nuclear localization signaling. We screened
these cell lines for genetic alterations of the RB2/p130 gene in the region of
the putative bipartite nuclear localization signal (NLS). This region is highly
homologous with that of the RB/p105 gene. In addition, we screened four primary
Burkitt's lymphomas for genetic alterations in the RB2/p130 gene. Naturally
occurring mutations, which disrupt the putative bipartite NLS, were found in
lymphoma cell lines and primary tumors, but not in the osteosarcoma cell lines,
where normal nuclear localization of the protein was detectable. Site-directed
mutagenesis and transfection assay using NLS mutants displayed markedly reduced
biological activity as measured by flow cytometric analysis. This study clearly
describes RB2/ p130 as an important target for mutations and subsequent
inactivation in lymphoma pathogenesis, thus validating that RB2/p130 is a
classical tumor suppressor gene.
PMID- 10667592
TI - Induced micronucleus frequencies in peripheral lymphocytes as a screening test
for carriers of a BRCA1 mutation in breast cancer families.
AB - Enhanced sensitivity to the chromosome-damaging effects of ionizing radiation is
a feature of many cancer-predisposing conditions. It has been suggested that
women with breast cancer are deficient in the repair of radiation-induced DNA
damage. We have now investigated whether mutagen sensitivity is related to
mutations in the breast cancer gene BRCA1. We studied the induction and repair of
DNA damage in lymphocytes of women from families with familial breast cancer and
breast and ovarian cancer. The mutagens used were gamma-irradiation and hydrogen
peroxide and the DNA effects were determined with the micronucleus test and the
comet assay. Women with a BRCA1 mutation (n = 12) and relatives without the
familial mutation (n = 10) were compared to controls (i.e., healthy women without
family history of breast or ovarian cancer; n = 17). Our results indicate a close
relationship between the presence of a BRCA1 mutation and sensitivity for the
induction of micronuclei. Compared to a concurrent control, 10 of 11 women with a
BRCA1 mutation showed elevated radiation sensitivity. Of the 10 related women
without the familial mutation, only 2 had clearly enhanced micronucleus
frequencies. In addition to the sensitivity toward gamma-irradiation,
hypersensitivity toward hydrogen peroxide was also observed, indicating that the
mutagen sensitivity is not solely due to a defect in the repair of DNA double
strand breaks. In contrast to the results with the micronucleus assay, we found
no significant difference between women with and without a BRCA1 mutation with
respect to the induction and repair of DNA damage in the comet assay. This
finding suggests a normal rate of damage removal and points to a disturbed
fidelity of DNA repair as a direct or indirect consequence of a BRCA1 mutation.
Our results support the usefulness of induced micronucleus frequencies as a
biomarker for cancer predisposition and suggest its application as a screening
test for carriers of a BRCA1 mutation in breast cancer families.
PMID- 10667593
TI - Atm deficiency causes an increased frequency of intrachromosomal homologous
recombination in mice.
AB - Ataxia telangiectasia (AT) patients have inactivating mutations in both copies of
the ATM gene. The ATM protein that the gene encodes is involved in DNA double
strand break (DSB) recognition; in its absence, p53 response to DSBs is delayed
and reduced. In addition, AT patients have a high propensity for cancer, and
cells from these patients show chromosomal instability. Here, using an in vivo
mouse model system with the pink-eyed unstable mutation, we demonstrate that the
absence of functional Atm results in a significantly elevated frequency of
intrachromosomal recombination resulting in deletion events (wild-type 17.73%,
heterozygous Atm 15.72%, and mutant Atm 30.33%). No such increase was observed in
mice heterozygous for Atm. These results further advocate the role of ATM in
maintaining genomic integrity after the onset of endogenous damage. This system
relies on the initiation of events during a relatively short time frame to
produce an observable deletion product. AT patients have a lifelong exposure to
endogenous damage and perhaps similarly acting external agents. Because 25% of
our genome consists of repeated elements, genomic instability due to an increased
level of homologous recombination between such repeats, as observed here, may
contribute to carcinogenesis in AT patients.
PMID- 10667594
TI - A dominant role for the c-Jun NH2-terminal kinase in oncogenic ras-induced
morphologic transformation of human lung carcinoma cells.
AB - Oncogenic (activated) Ras is a signal transducer that activates multiple effector
mediated signaling pathways leading to altered cell morphology, growth and
differentiation, and neoplastic transformation. Activating mutations of Ras
family genes have been detected in many types of human cancers, including lung
cancer. However, the signaling mechanisms by which oncogenic Ras controls cancer
cell growth is poorly characterized. This study evaluates the role of two
specific signaling pathways, the c-Jun NH2-terminal kinase (JNK) pathway, and the
extracellular signal-regulated kinase (ERK) pathway, in oncogenic Ras-induced
morphological transformation of NCI-H82 human small cell lung cancer cells. In
the NCI-H82 cell line, oncogenic Ras causes a marked and sustained activation of
JNK but only has a modest effect on activation of the ERK pathway. The persistent
JNK activation is associated with Ras-induced changes in cell morphology and
enhanced transforming activity. Furthermore, JNK activation correlates with the
induction of c-Jun expression, c-Jun phosphorylation on serines 63 and 73, and
increased AP-1 activity. Deregulation of the JNK pathway using a dominant
negative mutant of JNK1, JNK1(APF), completely reverses the oncogenic Ras-induced
transformed phenotype, including morphological reversion and inhibition of
anchorage-independent growth and low-serum growth. Moreover, expression of
JNK1(APF) leads to a decrease in c-Jun/AP-1 activity. In contrast, inhibition of
ERK activation via a pharmacological approach using a mitogen-activated protein
kinase/ERK kinase-specific inhibitor 2-(2'-amino-3'-methoxyphenyl)-oxanaphthalen
4-one is unable to reverse the Ras-induced transformed morphology and c-Jun/AP-1
induction. These results demonstrate that the JNK/c-Jun/AP-1 pathway plays an
essential role in mediating oncogenic Ras function in lung carcinoma cells.
PMID- 10667595
TI - Inherited predisposition to pancreatic adenocarcinoma: role of family history and
germ-line p16, BRCA1, and BRCA2 mutations.
AB - Susceptibility to pancreatic adenocarcinoma appears to be linked to germ-line
mutations in genes causing various familial cancer syndromes. The objectives of
this study were to estimate the proportion of unselected pancreatic cancer
patients belonging to hereditary cancer syndrome families and to determine the
frequency ofp16, BRCA1, BRCA2, hMSH2, and hMLH1 germ-line mutations in patients
with a personal or family history of cancer. The study population consisted of
102 patients with histologically verified pancreatic adenocarcinoma, unselected
for age, sex, family history, or ethnic origin. Patients completed a family
history questionnaire and provided blood for mutation analysis. Three-generation
pedigrees were constructed and classified as high risk/familial, intermediate
risk/ familial, intermediate risk/nonfamilial, or low risk according to defined
criteria. High- and intermediate-risk cases were analyzed for germ-line mutations
using a combination of methods. Thirty-eight of 102 (37%) patients were
characterized as high or intermediate risk, and the remainder were classified as
low risk. Germ-line mutations were identified in five (13%) of these cases [one
in p16 (I49S); one in BRCA1 (5382 insC); and three in BRCA2 (6174delT)]. The
BRCA1 and BRCA2 mutations were identified in Ashkenazi Jewish patients. Four of
the mutation carriers had strong family histories of the syndromes associated
with the mutated genes. No mutations were identified in patients in whom the sole
risk factor was a family history of pancreatic cancer, and only one mutation was
found among patients with early-onset disease. We conclude that known causes of
genetic predisposition are an important risk factor in a small proportion of
pancreatic cancer patients, especially if associated with a strong family history
of syndromes associated with the disease. The lack of detectable germ-line
mutations in most high- and intermediate-risk cases suggests that there are
probably additional, as yet unidentified genes predisposing to this disease.
PMID- 10667596
TI - Deregulation of the p14ARF/MDM2/p53 pathway is a prerequisite for human
astrocytic gliomas with G1-S transition control gene abnormalities.
AB - Deregulation of G1-S transition control in cell cycle is one of the important
mechanisms in the development of human tumors including astrocytic gliomas. We
have previously reported that approximately two-thirds of glioblastomas (GBs) had
abnormalities of G1-S transition control either by mutation/homozygous deletion
of RB1 or CDKN2A p16INK4A), or amplification of CDK4 (K. Ichimura et al.,
Oncogene, 13: 1065-1072, 1996). However, abnormalities of G1-S transition control
genes may induce p53-dependent apoptosis in cells. Recent investigations suggest
that p14ARF is induced in response to abnormal cell cycle entry and results in
p53 accumulation by inhibiting MDM2-mediated transactivational silencing and
degradation of p53. To investigate the roles of the G1-S transition control
system and the p14ARF/MDM2/p53 pathway in the development of astrocytic gliomas,
we examined abnormalities of genes involved in these regulatory pathways in a
total of 190 primary human astrocytic gliomas of different malignancy grades [136
GBs, 39 anaplastic astrocytomas (AAs) and 15 astrocytomas (As)]. Sixty-seven
percent of GBs (91/136) and 21% of AAs (8/39) had abnormalities of the G1-S
control system either by mutation/homozygous deletion of RB1, CDKN2A or CDKN2B,
or amplification of CDK4. Seventy-six percent of GBs (103 of 136), 72% of AAs (28
of 39), and 67% of As (10 of 15) had deregulated p53 pathway either by mutation
of TP53, amplification of MDM2, or homozygous deletion/mutation of p14ARF. When
all of the data were combined and compared, 96% of GBs (87 of 91) and 88% of AAs
(7 of 8) with abnormal G1-S transition control also had deregulated p53 pathway.
Thus, we demonstrate that deregulation of the G1-S transition control system was
almost always accompanied by inactivation of the p53 pathway, clearly
illustrating the cooperative roles of these two systems in the
development/progression of primary human astrocytic gliomas.
PMID- 10667597
TI - ZK7, a novel zinc finger gene, is induced by vascular endothelial growth factor
and inhibits apoptotic death in hematopoietic cells.
AB - Vascular endothelial growth factor (VEGF) inhibits radiation-induced apoptosis in
the leukemia cell line, CMK86 (O. Katoh et al., Cancer Res., 55: 5687-5692,
1995). To elucidate the molecular mechanisms underlying this inhibitory effect of
VEGF, we attempted to identify a transcription factor involved in the cellular
response to VEGF stimulation. We cloned the cDNA of a novel Kruppel-type zinc
finger (ZNF) gene, ZK7, from a cDNA library constructed from the human leukemia
cell line CMK86 after incubation with VEGF. This cDNA encoded a protein of 289
amino acids, which contained a Kruppel-associated box A-box domain at the NH2
terminus and seven ZNF motifs at the COOH terminus. These ZNF motifs were
identical to those of HZF16 (M. Saleh et al., Am. J. Hum. Genet., 52: 192-203,
1993). ZK7 and HZF16 genes appear to be the splice variants transcribed from the
same gene. Northern blotting and quantitative reverse transcription-PCR analysis
revealed that expression of ZK7 mRNA in CMK86 cells and human hematopoietic
progenitor cells was increased after VEGF stimulation, whereas that of HZF16 mRNA
remained unchanged. To examine the function of ZK7 protein, we generated clones
of a human monocytoid leukemia cell line, U937, which were stably transfected
with ZK7 or HZF16 cDNA. Importantly, ZK7-overexpressing cells had lower
sensitivity to ionizing radiation and the chemotherapeutic agent etoposide than
U937 parent cells or HZF16-overexpressing cells. Therefore, ZK7 protein may be
involved in the inhibitory effect of VEGF on apoptotic cell death in human
hematopoietic cells.
PMID- 10667598
TI - The cancer-free phenotype in trichothiodystrophy is unrelated to its repair
defect.
AB - The DNA repair-deficient genetic disorders xeroderma pigmentosum (XP) and
trichothiodystrophy (TTD) can both result from mutations in the XPD gene, the
sites of the mutations differing between the two disorders. The hallmarks of XP
are multiple pigmentation changes in the skin and a greatly elevated frequency of
skin cancers, characteristics that are not seen in TTD. XP-D and most TTD
patients have reduced levels of DNA repair, but some recent reports have
suggested that the repair deficiencies in TTD cells are milder than in XP-D
cells. We reported recently that inhibition of intracellular adhesion molecule-1
(ICAM-1) expression by UVB irradiation was similar in normal and TTD cells but
increased in XP-D cells, suggesting a correlation between ICAM-1 inhibition and
cancer proneness. In the first part of the current work, we have extended these
studies and found several other examples, including XP-G and Cockayne syndrome
cells, in which increased ICAM-1 inhibition correlated with cancer proneness.
However, we also discovered that a subset of TTD cells, in which arg112 in the
NH2-terminal region of the XPD protein is mutated to histidine, had an ICAM-1
response similar to that of XP-D cells. In the second part of the work, we have
shown that TTD cells with this specific NH2-terminal mutation are more sensitive
to UV irradiation than other TTDs, most of which are mutated in the COOH-terminal
region, and are indistinguishable from XP-D cells in cell killing, incision
breaks, and repair of cyclobutane pyrimidine dimers. Because the clinical
phenotypes of these patients do not obviously differ from those of TTDs with
mutations at other sites, we conclude that the lack of skin abnormalities in TTD
is independent of the defective cellular responses to UV. It is likely to result
from a transcriptional defect, which prevents the skin abnormalities from being
expressed.
PMID- 10667599
TI - Interaction with endothelial cells is a prerequisite for branching ductal
alveolar morphogenesis and hyperplasia of preneoplastic human breast epithelial
cells: regulation by estrogen.
AB - Although there is experimental evidence supporting the involvement of
angiogenesis in the pathogenesis of breast cancer, the exact nature and effects
of interaction between human breast epithelial cells (HBECs) and endothelial
cells (ECs) have not been described thus far. This approach requires an assay
system that permits growth and differentiation of both epithelial and endothelial
cells. Here, we report the development of a three-dimensional in vitro culture
system that supports growth and functional differentiation of preneoplastic HBECs
and ECs and recapitulates estrogen-induced in vivo effects on angiogenesis and
the proliferative potential of MCF10AT xenografts. MCF10A and MCF10AT1-EIII8
(referred to as EIII8) cell lines used in this study are normal or produce
preneoplastic lesions, respectively. When MCF10A or EIII8 cells are seeded on
reconstituted basement membrane (Matrigel), both lines organize into a three
dimensional tubular network of cells; however, tubes produced by EIII8 cells
appear multicellular in contrast to unicellular structures formed by MCF10A
cells. However, when MCF10A or EIII8 cells are cocultured with human umbilical
vein endothelial cells (HUVECs) on Matrigel, rather than interacting with
extracellular matrix, the ECs exhibit preferential adherence to epithelial cells.
Although both MCF10A and EIII8 cells provide preferential substrate for EC
attachment, only EIII8 cells facilitate sustained proliferation of ECs for
prolonged periods that are visualized as "endothelial cell enriched spots," which
express factor VIII-related antigen. At regions of endothelial-enriched spots,
preneoplastic HBECs undergo branching ductal-alveolar morphogenesis that produce
mucin, express cytokeratins, and proliferating cell nuclear antigen. The presence
of actively proliferating and functional endothelial cells is essential for
ductal-alveolar morphogenesis of preneoplastic HBECs because without ECs, the
epithelial cells formed only tubular structures. This ability to establish
functional ECs and ductal-alveolar morphogenesis is facilitated only by
preneoplastic HBECs because normal MCF10A cells fail to elicit similar effects.
Thus, a cause-effect relationship that is mutually beneficial exists between EC
and preneoplastic HBECs that is critical for generation of functional vascular
networks and local proliferative ductal alveolar outgrowths with invasive
potential. Both these processes are augmented by estrogen, whereas antiestrogens
inhibit these processes. Induction and maintenance of angiogenic phenotype is
associated with up-regulation in expression of interleukin 8 and matrix
metalloproteinase-2 and estrogen-induced increases in vascular endothelial growth
factor and vascular endothelial growth factor receptor 2. This three-dimensional
culture model offers a unique opportunity to study endothelial- and epithelial
cell-specific factors that are important for ductal-alveolar morphogenesis,
angiogenesis, and progression to malignant phenotype.
PMID- 10667600
TI - A peptide mimic of E-selectin ligand inhibits sialyl Lewis X-dependent lung
colonization of tumor cells.
AB - Selectins bind to carbohydrate ligands in a calcium-dependent manner and play
critical roles in host defense and possibly in tumor metastasis. To isolate
peptides that mimic E-selectin ligands, we screened a phage peptide library using
E-selectin as a target molecule. This attempt unexpectedly failed, probably
because the binding affinity of E-selectin to its ligand is low. We then took an
approach that is analogous to the isolation of anti-idiotype antibodies and were
able to isolate peptides that bound to anticarbohydrate antibodies recognizing E
selectin ligands. These peptides, enriched for their binding to anti-Lewis A
antibody, were found to bind to E-, P- and L-selectins in a calcium-dependent
manner. Phage harboring the identified peptide IELLQAR and synthetic peptides
having the same sequence inhibited the binding of sialyl Lewis X or sialyl Lewis
A oligosaccharides to E-selectin. The adhesion of HL-60 and B16 melanoma cells
expressing sialyl Lewis X to E-selectin was also inhibited by the phage
displaying IELLQAR peptide. Moreover, i.v. injected IELLQAR peptide inhibited the
lung colonization of mouse B16 melanoma and human lung tumor cells expressing
sialyl Lewis X. These results demonstrate that it is possible to isolate peptides
mimicking carbohydrate ligands by screening the peptides for binding to
anticarbohydrate antibodies and then using them to inhibit carbohydrate-dependent
experimental tumor metastasis.
PMID- 10667601
TI - Thrombospondin-1 promotes alpha3beta1 integrin-mediated adhesion and neurite-like
outgrowth and inhibits proliferation of small cell lung carcinoma cells.
AB - Although human small cell lung carcinoma (SCLC) cell lines are typically
anchorage-independent and do not attach on most extracellular matrix proteins, OH
1, and several other SCLC cell lines attached on substrates coated with
thrombospondin-1 (TSP1). SCLC cells grew long-term as adherent cells on a TSP1
coated substrate. Adhesion of SCLC cells on TSP1 was inhibited by heparin,
function-blocking antibodies recognizing alpha3 or beta1 integrin subunits, and
by soluble alpha3beta1 integrin ligands. SCLC cells extended neurite-like
processes on a TSP1 substrate, which was also mediated by alpha3beta1 integrin.
Process formation on a TSP1 substrate was specifically stimulated by epidermal
growth factor and somatostatin. Adhesion on TSP1 weakly inhibited SCLC cell
proliferation, but this inhibition was strongly enhanced in the presence of
epidermal growth factor. TSP1 and an alpha3beta1 integrin-binding peptide from
TSP1 also inhibited proliferation when added in solution. High-affinity binding
of 125I-labeled TSP1 to OH-1 cells was heparin-dependent and may be mediated by
sulfated glycolipids, which are the major sulfated glycoconjugates synthesized by
these cells. Synthesis or secretion of TSP1 by SCLC cells could not be detected.
On the basis of these results, the alpha3beta1 integrin and sulfated glycolipids
cooperate to mediate adhesion of SCLC cells on TSP1. Interaction with TSP1
through this integrin inhibits growth and induces neurotypic differentiation,
which suggests that this response to TSP1 may be exploited to inhibit the
progression of SCLC.
PMID- 10667602
TI - A specific sequence of the noncollagenous domain of the alpha3(IV) chain of type
IV collagen inhibits expression and activation of matrix metalloproteinases by
tumor cells.
AB - The invasive properties of melanoma cells correlate with the expression of matrix
metalloproteinases (MMPs) and their physiological modulators (tissue inhibitors
of metalloproteinase and membrane-type MMPs) and with that of the alphaVbeta3
integrin. We investigated the effect of anterior lens capsule type IV collagen
and of the alpha3(IV) collagen chain on the invasive properties of various tumor
cell lines (HT-144 melanoma cells, HT-1080 fibrosarcoma cells). We demonstrated
that anterior lens capsule type IV collagen or specifically the synthetic peptide
alpha3(IV) 185-203 inhibited both the migration of melanoma or fibrosarcoma cells
as well as the activation of membrane-bound MMP-2 by decreasing the expressions
of MT1-MMP and the beta3 integrin subunit.
PMID- 10667604
TI - Processing of cyclin E differs between normal and tumor breast cells.
AB - Cyclin E is a G1 cyclin essential for G1 to S-phase transition of the cell cycle
with a profound role in oncogenesis. In tumor cells and tissues, cyclin E is
overexpressed and present in its lower molecular weight (LMW) isoforms, and it
can be used as a prognosticator for poor patient outcome. In this study, we have
examined differences in the processing of cyclin E between normal mammary
epithelial and breast cancer cell lines. Five NH2-terminally deleted epitope
tagged (FLAG) cyclin E vectors were constructed spanning the range of LMW forms
observed in tumor cells. These constructs were transfected into normal and tumor
cells and analyzed for the production of cyclin E-FLAG protein products by
Western blot analysis with FLAG and cyclin E antibodies. Our results show that
only tumor cells had the machinery to process these cyclin E-FLAG constructs to
their LMW forms, whereas normal cells mainly expressed the full-length
unprocessed form of each protein. Tumor and normal cells always process the
cyclin E-FLAG protein in the same way as endogenously expressed cyclin E. This
phenomenon is consistent with all of the cell lines used, regardless of
transfection efficiency, time of processing posttransfection, or method of
transfection. Furthermore, measurement of FLAG-associated kinase activity in the
transfectants revealed that the protein products of the cyclin E-FLAG constructs
are 10 times more active in tumor cells than in normal cells. These studies
suggest that the LMW forms of cyclin E detected at a much higher level in tumor
cells arise from posttranslational action of a protease.
PMID- 10667603
TI - Heregulin regulation of autocrine motility factor expression in human tumor
cells.
AB - The exposure of cells to growth factors has been shown to induce cytoskeleton
reorganization, leading to stimulation of cell motility and invasion. Heregulin
beta1 (HRG), a combinatorial ligand for human epidermal growth factor receptor 3
and human epidermal growth factor receptor 4 receptors, is a regulatory secretory
polypeptide with a distinctive function in promoting motility and invasiveness of
breast cancer cells. In addition to HRG, motility and invasiveness of tumor cells
may also involve up-regulation of expression and function of the autocrine
motility factor (AMF). Here we explored the possible involvement of AMF in the
motility-promoting action of HRG in the MCF-7 breast cancer cell model system. We
report that HRG increases the expression of AMF mRNA by 3-8-fold in an
actinomycin D-sensitive manner and does not require de novo protein synthesis.
The HRG-induced stimulation of AMF expression was inhibited by specific
inhibitors of p42/44MAPK and p38MAPK kinases, but not by an inhibitor of the
phosphatidylinositol 3'-kinase pathway. Other HRG-responsive human cell lines
demonstrated that HRG does indeed significantly up-regulate AMF expression.
Furthermore, HRG-stimulated increased motility was partially suppressed by
inclusion of an anti-AMF antibody to breast cancer cells, suggesting that a HRG
mediated increase in cell motility may be mediated, at least in part, via
induction of AMF. The present study is the first demonstration of AMF regulation
by a growth factor and suggests a potential role for AMF in HRG regulation of
breast cancer cell motility and a novel function of HRG as a regulator of
motility factor expression.
PMID- 10667606
TI - Correspondence re: J.L. Stanford et al., Polymorphic receptor in the androgen
receptor gene: molecular markers of prostate cancer risk. Cancer Res., 57: 1194
1198, 1997.
PMID- 10667605
TI - Oncogenes and tumor angiogenesis: differential modes of vascular endothelial
growth factor up-regulation in ras-transformed epithelial cells and fibroblasts.
AB - A possible link between oncogenes and tumor angiogenesis has been implicated by
the finding that expression of various oncogenes, particularly mutant ras, can
lead to a marked induction of a potent paracrine stimulator of angiogenesis,
vascular endothelial growth factor (VEGF). We sought to determine how oncogenic
ras induction of VEGF is mediated at the molecular level and whether the
mechanisms involved differ fundamentally between transformed epithelial cells and
fibroblasts. Our results suggest that in a subline (called RAS-3) of immortalized
nontumorigenic rat intestinal epithelial cells (IEC-18) that acquired a
tumorigenic phenotype upon transfection of mutant ras, up-regulation of VEGF
occurs in the absence of an autocrine growth factor circuit. The expression of
VEGF mRNA and protein by RAS-3 cells was strongly suppressed in the presence of
LY294002, an inhibitor of phosphatidylinositol 3'-kinase, but remained largely
unaffected in the same cells treated with an inhibitor (PD98059) of mitogen
activated protein/extracellular signal-regulated kinase kinase 1 (MKK/MEK-1).
This is consistent with the observation that overexpression of a constitutively
activated mutant of MEK-1 (AN3/ S222D) in the parental IEC-18 cells did not
result in up-regulation of VEGF production. The impact of mutant ras on VEGF
expression was also significantly amplified at high cell density, conditions
under which RAS-3 cells became less sensitive to LY294002-induced VEGF down
regulation. In marked contrast to cells of epithelial origin, ras-transformed
murine fibroblasts (3T3RAS) up-regulated VEGF in a manner that was strongly
inhibitable by MEK-1 blockade (ie. treatment with PD98059), whereas these cells
were relatively unaffected by treatment with the phosphatidylinositol 3'-kinase
inhibitor LY294002. In addition, VEGF was up-regulated by 2-3-fold in NIH3T3
cells overexpressing mutant MEK-1. Collectively, the data suggest that the
stimulatory effect of mutant ras on VEGF expression is executed in a nonautocrine
and cell type-dependent manner and that it can be significantly exacerbated by
physiological/ environmental influences such as high cell density.
PMID- 10667607
TI - Present and future capabilities of molecular imaging techniques to understand
brain function.
AB - This article focuses on the use of positron emitting tracers and positron
emission tomography (PET) as the most specific and sensitive means for imaging
molecular interactions and pathways within the human brain. The concept of the
imaging science of PET is developed whereby the key components that contribute to
the overall accuracy of the image of molecular activity need to be separately
optimized. These include radiolabelling of tracer molecules and ligands with
radioisotopes of short radioactive half-life, the search for specific
radioligands and tracers, and hence the need to mine molecular databases for
molecules suitable for in-vivo imaging. The sensitivity and accuracy of PET
scanners need to be advanced along with improvements in the signal-to-noise ratio
of the tomographic reconstruction algorithms. Finally, the models used for the
analysis of serial time frames of kinetic data need to be developed, the
operation of which have to be effected with the minimum of noise propagation. The
future use of PET for drug discovery and development is discussed whereby it
offers proof principle for assays of in-vivo expression of therapeutic molecular
targets as accessed from the blood stream; tissue pharmacokinetics of novel
compounds; degree of occupancy of molecular targets; and pharmacodynamic measures
of drug action. The future application of PET rests heavily on drug discoverers
contributing to discovering specific PET radioligands and tracers in order to
provide these assays through in-vivo molecular imaging.
PMID- 10667608
TI - Magnetic resonance imaging and magnetic resonance spectroscopy assessment of
brain function in experimental animals and man.
AB - This paper introduces the basic principles and techniques of functional magnetic
resonance imaging (fMRI) and spectroscopy (MRS). Examples are given of single
event human fMRI studies on control subjects, and a graded activation protocol
applied to Parkinsonian patients. Possibilities are discussed for using fMRI
techniques to study the neural substrate of various pharmacological agents,
including drugs of abuse. The application of these pharmacological MRI (phMRI)
studies to animal models and the associated technical issues are also addressed.
The use of MRS in studying brain status and function is reviewed, with particular
emphasis on 13C isotopic labelling studies.
PMID- 10667609
TI - Imaging studies on the role of dopamine in cocaine reinforcement and addiction in
humans.
AB - We summarize our studies with positron emission tomography investigating the role
of dopamine (DA) in the reinforcing effects of cocaine and methylphenidate in
humans and its involvement in cocaine addiction. These studies have shown that
the rate at which cocaine and methylphenidate enter the brain and block the
dopamine transporters (DAT) is the variable associated with the 'high', rather
than the presence per se of the drug in the brain. Our studies also show that,
while the level of DAT blockade is important in predicting the intensity of the
'high' induced by these drugs (DAT blockade > 50% is required for these drugs to
induce a 'high'), the rate at which DAT are blocked determines whether the 'high'
is perceived or not. Thus, oral methylphenidate, which leads to slow DAT
blockade, does not induce a 'high', even at doses which block DAT more than 60%.
In cocaine abusers, we have shown significant reductions in DA D2 receptors that
are associated with decreased metabolism in cingulate gyrus and in orbitofrontal
cortex. We suggest that this is one of the mechanisms by which DA disruption
leads to compulsive drug administration in cocaine addiction. Cocaine abusers
also show significant decreases in DA release, which coupled with the reduction
in D2 receptors may result in decreased activation of reward circuits by
physiological reinforcers and may perpetuate cocaine use as a means to compensate
for this deficit. Thus, strategies to enhance DA brain function in ways that
mimic physiological DA activity may be of help in overcoming cocaine addiction.
PMID- 10667610
TI - Imaging strategies in depression.
AB - Functional brain imaging in depressive disorder aims to map brain areas
associated with depressive illness or to define the neurochemical correlates of
the illness and its treatment. Regional deficits of functional (neural) activity
has been consistently detected in the brains of subjects with ongoing affective
symptoms, particularly in prefrontal areas. Understanding how these prefrontal
deficits can be related to neuroanatomical circuitry, neurochemistry and normal
cognitive functions is the major challenge in taking these findings forward.
Although many neurochemical systems remain to be adequately imaged in vivo,
significant progress has been made in the development of relevant radiotracers,
particularly for select serotonin and dopamine receptor subtypes. For the future,
functional brain imaging of the neurochemistry associated with core symptoms and
treatment responses will be necessary for an adequate description of the
pathophysiology of depressive illness.
PMID- 10667611
TI - Radio-imaging in small animals.
AB - As the resolution of radio-imaging systems improves, the prospect of in-vivo
imaging of small animals becomes more attractive. Purpose-built positron emission
tomography (PET) scanners capable of imaging individual tissues within the rat
brain are now in routine experimental use and in-vivo tracer and saturation
kinetic studies are now possible. The study of small animals in this way does
have intrinsic problems and constraints associated with it. For example, the
animal must be completely immobilized, stable ligand within the radiolabelled
preparation may be limiting and anatomical definition may be poor. In spite of
this, consistent, semi-quantitative data can be produced and in-vivo radio
imaging can provide a genuine and unique complement to more conventional
techniques. Animal numbers can be significantly reduced and the quality of data
improved due to reduced inter-animal variation, and longitudinal studies, to
monitor disease progression, are feasible. As the resolution of imaging systems
improves still further, such studies could be extended to mouse, in addition to
rat, models of disease.
PMID- 10667612
TI - Dopamine as the wind of the psychotic fire: new evidence from brain imaging
studies.
AB - Abnormalities of dopamine function in schizophrenia are suggested by the common
antidopaminergic properties of antipsychotic medications. However, direct
evidence of a hyperdopaminergic state in schizophrenia has been difficult to
demonstrate, given the difficulty of measuring dopamine transmission in the
living human brain. This situation is rapidly changing. Recent developments in
positron emission tomography and single-photon emission tomographic techniques
enabled measurement of acute fluctuation of synaptic dopamine in the vicinity of
D2 receptors. Using this technique, we, and others, measured the increase in
dopamine transmission following acute amphetamine challenge in untreated patients
with schizophrenia and matched healthy subjects. Following a brief overview of
these new brain imaging techniques, the main results derived with this method in
patients with schizophrenia are described: (1) amphetamine-induced dopamine
release is elevated in patients with schizophrenia, supporting the idea that
schizophrenia is associated with dysregulation of dopamine transmission; (2)
following amphetamine, hyperactivity of dopamine transmission is associated with
activation of psychotic symptomatology; (3) this dysregulation of dopamine
release is not a long-term consequence of previous neuroleptic treatment, and is
detected in never-medicated patients experiencing a first episode of the illness;
and (4) in contrast, this exaggerated response of the dopamine system to
amphetamine exposure is not detected in patients studied during a period of
illness stabilization, suggesting that the hyperdopaminergic state associated
with schizophrenia fluctuates over time. In conclusion, a hyperdopaminergic state
might be present in schizophrenia during the initial episode and subsequent
relapses, but not during periods of remission. This finding has important
consequences for the development of new treatment strategies for the remission
phase.
PMID- 10667613
TI - What do brain imaging studies tell us about anxiety disorders?
AB - In-vivo neuroimaging allows the investigation of brain circuits involved in the
experience of anxiety and of receptor changes associated with anxiety disorders.
This review focuses on studies by research groups who have compared brain
activation maps in different forms of anxiety and on binding studies of the
benzodiazepine-GABA(A) receptor. Activation studies have revealed the involvement
of many brain areas depending on the condition and the paradigm. However, the
orbitofrontal cortex/anterior insula and the anterior cingulate are implicated in
all the studies and may represent the nodal point between somatic and cognitive
symptoms of any form of anxiety. Most studies of binding at the benzodiazepine
GABA(A) receptor are not interpretable because of substantial methodological
problems, however, regional and/or global reductions are the most consistent
finding in panic disorder.
PMID- 10667614
TI - Comparison of the effects of alpha-methyl-p-tyrosine and a tyrosine-free amino
acid load on extracellular noradrenaline in the rat hippocampus in vivo.
AB - Peripheral administration of an amino acid load lacking tyrosine and its
precursor, phenylalanine, causes a lowering of central tyrosine levels. The aim
of the present study was to examine the effects of tyrosine depletion on
extracellular noradrenaline using microdialysis. Extracellular noradrenaline was
measured in hippocampus of the anaesthetized rat under both baseline conditions
(with reuptake inhibitor, desipramine, in the perfusion medium) and following
administration of the alpha2-adrenoreceptor antagonist, idazoxan. The tyrosine
free amino acid load did not alter either baseline noradrenaline or the twofold
rise in noradrenaline evoked by idazoxan compared with saline controls. In
contrast, the catecholamine synthesis inhibitor, alpha-methyl-p-tyrosine, caused
a marked reduction in baseline extracellular noradrenaline and abolished the rise
induced by idazoxan. In conclusion, the present data indicate that under the
conditions used, a tyrosine-free amino acid mixture may not be an effective means
to interfere with central noradrenaline function. This contrasts with recent
findings demonstrating that the tyrosine-depletion approach can be used to
decrease presynaptic dopamine function.
PMID- 10667615
TI - Effects of CCK-4 infusion on the acoustic eye-blink startle and
psychophysiological measures in healthy volunteers.
AB - The acoustic startle response (ASR) and a range of psychophysiological parameters
were evaluated during a continuous intravenous administration of cholecystokinin
tetrapeptide (CCK-4) in healthy volunteers. Subjects (n=28) were randomly
assigned to double-blind infusion of either CCK-4 (0.5 mg/60 min) or placebo. The
ASR sessions were performed prior to infusion and at 20 min and 50 min after the
onset of infusion by recording eye-blink response to a series of acoustic stimuli
(110 dB, 40 ms). An effect of CCK-4 on the eye-blink startle was observed in the
first half of infusion. CCK-4 produced an increase of eye-blink startle amplitude
from baseline values in contrast to the decrease observed at this time point with
placebo. A mild increase in anxiety and heart rate followed by fatigue was
reported with CCK-4. Administration of CCK-4 produced increases in plasma
concentrations of adrenocorticotropic hormone, cortisol, prolactin and growth
hormone. The results of this study show that a prolonged intravenous
administration of CCK-4 may be a useful challenge method for further studies on
the role of CCK system in the modulation of human anxiety and stress response.
PMID- 10667616
TI - The effects of the novel anxiolytic drug lesopitron, a full and selective 5-HT1A
receptor agonist, on pupil diameter and oral temperature in man: comparison with
buspirone.
AB - We investigated the effects of two 5-HT1A receptor agonists, buspirone and
lesopitron, upon pupil size in human volunteers at an ambient luminance level of
32 Cd m(-2) and in darkness. Pupil diameter was monitored with a binocular
infrared television pupillometer, before and after the administration of
treatments for 4 h at 20-min intervals. Two experiments were conducted. In
Experiment 1, 14 healthy male volunteers participated in seven weekly sessions,
each associated with the ingestion of one capsule (buspirone 5, 10 and 20 mg,
lesopitron 10, 20 and 40 mg and placebo), according to a double-blind balanced,
cross-over design. Both buspirone and lesopitron tended to decrease pupil
diameter. In darkness, only the highest dose of buspirone (20 mg) caused a miosis
that was statistically significant. However, at the luminance level of 32 Cd m(
2) buspirone 10 and 20 mg evoked statistically significant miotic effects, as did
the highest dose of lesopitron (40 mg). The miotic effect was significantly
greater at 32 Cd m(-2) than in darkness after each dose of buspirone and the
highest dose (40 mg) of lesopitron. In Experiment 2, pupil diameter and oral
temperature were monitored with an electronic thermometer at 40-min intervals.
Twenty healthy male volunteers participated in two weekly sessions, each
associated with the sublingual application of 100 microl hydroalcoholic solution
(lesopitron 20 mg, placebo), according to a double-blind balanced cross-over
design. Lesopitron caused a significant miosis both in darkness and at the
luminance level of 32 Cd m(-2); the miosis was greater at 32 Cd m(-2) than in
darkness. Lesopitron tended to decrease oral temperature; this effect however,
was not statistically significant. The greater effectiveness on the pupil of
lesopitron administered sublingually in a solution indicates the importance of
first-pass metabolism in reducing the effectiveness of the drug when administered
by the mouth. The miosis observed in both experiments may be due to either a
sympatholytic or a parasympathomimetic effect of the drugs, or both. The light
dependence of the miosis indicates that the 5-HT1A receptor agonists can modulate
the light reflex, possibly via the noradrenergic control of central cholinergic
neurones in the Edinger-Westphal nucleus.
PMID- 10667617
TI - Effects of d-amphetamine and haloperidol on latent inhibition in healthy male
volunteers.
AB - Latent inhibition (LI) refers to a retardation of learning about the consequences
of a stimulus when that stimulus has been passively presented a number of times
without reinforcement. Acute positive-symptom schizophrenics, normal volunteers
who score high on questionnaire measures of schizotypy and non-patients or
animals treated with dopamine agonists show reduced LI. Neuroleptic drugs, such
as haloperidol, administered at low doses, potentiate LI and effectively reverse
disruption of LI induced by dopamine agonists in animals. However, a high dose of
haloperidol, administered on its own, has been found to reduce LI. We examined
the effects on LI of acute oral administration of an indirect dopamine-agonist, d
amphetamine (5 mg), and a nonselective dopamine receptor antagonist, haloperidol
(5 mg), in normal male volunteers, using an associative learning task.
Replicating previous reports, we found that d-amphetamine reduced LI; haloperidol
also reduced LI, but only in subjects who scored low on the Psychoticism scale of
the Eysenck Personality Questionnaire. In a subsequent study, no effect was found
of 2 mg oral haloperidol administration on LI. The effect of 5 mg haloperidol on
LI is interpreted as similar to that observed with a high dose of haloperidol in
rats.
PMID- 10667618
TI - A 12-week study comparing moclobemide and sertraline in the treatment of
outpatients with atypical depression.
AB - One hundred and ninety-seven outpatients with atypical depression [Atypical
Depression Diagnostic Scale (ADDS) score=4] were randomized to 12 weeks of double
blind treatment with sertraline or moclobemide in a multicentre, parallel-group
clinical trial. Patients were started on either 50 mg/day sertraline or 300
mg/day moclobemide. If the therapeutic response was not satisfactory after 4
weeks, the dose could be increased to either 100 mg/day sertraline or 450 mg/day
moclobemide. Primary efficacy evaluations were the 29-item Hamilton Psychiatric
Rating Scale for Depression (HAM-D) and the Clinical Global Impression of
Improvement (CGI-I) response rate (much or very much improved) at study endpoint.
Secondary efficacy evaluations included the ADDS, the Hamilton Anxiety Scale
(HAMA), the Leeds Sleep Scale, and the Battelle Quality of Life Battery (BQOLB).
In the analysis of the 172 patient efficacy-evaluable population, there was
significant baseline to endpoint improvement in all primary and secondary
efficacy assessments after treatment with either sertraline or moclobemide. At
the endpoint, the proportion of responders on CGI-I, was 77.5% in the sertraline
group and 67.5% in the moclobemide group (p=0.052). The baseline to endpoint mean
29-item HAM-D score decreased from 35.9 to 14.5 in the sertraline group and from
36.3 to 16.1 in the moclobemide group. Sertraline also resulted in a
significantly (p < 0.05) greater degree of improvement at the endpoint, compared
with moclobemide, in the proportion of remitters on the HAMA (total score < or =
7), ADDS Category IID (Rejection Sensitivity), Leeds Sleep Factor 4 (Integrity of
Behaviour Following Awakening), and on three dimensions of the BQOLB
(Energy/Vitality, Social Interaction and Life Satisfaction). There were no other
significant differences between treatment groups. Overall, both medications were
well tolerated. In this study, both sertraline and moclobemide improved the
symptoms of atypical depression.
PMID- 10667619
TI - Evidence-based psychopharmacology 2. Appraising a systematic review: is
risperidone better than conventional antipsychotics in the treatment of
schizophrenia?
AB - Systematic reviews are increasingly used to combine the results of several
studies in order to define the treatment effect with a high degree of precision.
However, reviews of this nature may lead to spurious results and should not be
accepted uncritically. This article, the second in a series on evidence-based
psychopharmacology, is intended to illustrate the process of critical appraisal
of a systematic review. In this example, a systematic review of studies comparing
risperidone with conventional antipsychotics is appraised. Interpretation of the
results of the systematic review may be hampered by the way in which studies were
selected.
PMID- 10667620
TI - Withdrawal syndrome following long-term administration of tamoxifen.
PMID- 10667621
TI - Loss of anxiety and increased aggression in a 15-year-old boy taking fluoxetine.
PMID- 10667622
TI - Rapid tranquillisation in isolated units, i.m. medication preferable to i.v.
PMID- 10667623
TI - Oral support measures used in feeding the preterm infant.
AB - BACKGROUND: Evidence that bottle-feeding is a stressor for inefficient preterm
infant feeders is seen in untoward changes in the physiologic system and
nutritive sucking patterns. OBJECTIVE: To determine whether a therapeutic
technique, oral support (cheek and jaw support), would influence the
cardiopulmonary functions or nutritive sucking patterns of preterm infants during
feeding. METHODS: A crossover repeated measures design was used with 20 preterm
infants for a total of 40 bottle-feeding sessions. The Whitney Mercury Strain
Gage and a Nonin Cardiopulmonary monitor were used to observe sucking
characteristics and cardiopulmonary functions during feeding. RESULTS: Infants
not receiving support paused longer (F= 6.37, df= 5, p < .001) and more
frequently (F= 5.01, df= 5, p < .001) than supported infants. There were no
differences between the groups in the number of sucks and bursts, the burst
duration, the stability of the total sucking activity, or the rate of sucking.
Oxygen saturation (SaO2) values, heart rate, and respiratory rate did not differ
between the groups during feeding. Postfeeding SaO2 levels were lower than
prefeeding levels for infants not receiving oral support (t= 0.96, df= 19, p=
.03). CONCLUSION: Oral support provided stability for the jaw and fostered the
return of the infant's prefeeding SaO2 values, but it did not interfere with
cardiopulmonary function during feeding. Further research is needed to determine
whether there is a cumulative effect of oral support, and whether it influences
state behavior.
PMID- 10667624
TI - Influence of attention and judgment on perception of breathlessness in healthy
individuals and patients with chronic obstructive pulmonary disease.
AB - BACKGROUND: Cognitive processes mediate judgments of sensation intensity and the
perception of breathlessness. These processes depend on focused attention to make
a determination, which has not been systematically investigated. OBJECTIVE: To
examine the effect of attention on the perception of breathlessness given
alterations in attentional focus based on the subject's experience with the
perception. METHODS: Magnitude estimation techniques with inspiratory airflow
resistance were used to examine the influence of variations in attentional focus
on the judgments associated with the perception of breathlessness. Two
experimental magnitude estimation conditions were used to alter the focus of
attention and compare it with traditional techniques as a control condition (CC).
The subject's typical breathing pattern (EXP-T) and clearest memory of
breathlessness (EXP-M) were used as references in the experimental conditions.
RESULTS: Findings revealed a significant main effect for condition (CC vs. EXP-T:
F= 4.82, p < .01; CC vs. EXP-M: F= 14.82, p < .01) and an interaction effect for
group by condition (CC vs. EXP-T: F = 4.82, p < .03; CC vs. EXP-M: F = 5.15, p <
.03). Post hoc analysis revealed significant differences only for the chronic
obstructive pulmonary disease (COPD) group in both comparisons. CONCLUSIONS:
Findings indicate that different focuses of attention based on previous exposure
to sensations have an impact on judgments used to determine the intensity of a
sensation given similar presentation of stimuli, and thus contribute to
alterations in the perception of breathlessness.
PMID- 10667625
TI - Factors associated with participation by Mexican migrant farmworkers in a
tuberculosis screening program.
AB - BACKGROUND: Tuberculosis is an important public health concern among migrant
farmworkers in the United States; providing appropriate screening and treatment
is difficult due to their highly mobile existence. PURPOSE: To analyze the
relationship between variables (susceptibility, severity, barriers, benefits,
cues to action, normative beliefs, subjective norm, attitude, and intention) from
the Health Belief Model (HBM) and the Theory of Reasoned Action (TRA) and
participation by Mexican migrant farmworkers in a tuberculosis screening program.
METHOD: A convenience sample of 206 migrant farmworkers were recruited after a
presentation of a tuberculosis education program and were tracked during the
administration and reading of the tuberculosis skin test. Participants were
interviewed in Spanish by the principal investigator using the Tuberculosis
Interview Instrument (TII) developed for this study. RESULTS: Most subjects were
male, aged 18-27 years, and had less than a sixth-grade education. Of the 206
subjects, 152 (73.4%) received the skin test, 149 (98%) had the skin test read,
and 44 (29.5%) had positive skin tests. Based on logistic regression analysis,
the model that best predicted intention included cues to action, subjective norm,
susceptibility, and attitude. Participation in screening was best predicted by a
model containing only two variables: intention and susceptibility. CONCLUSIONS:
In this study, logistic regression analysis revealed that a more parsimonious
model than the full HBM and TRA model accurately predicted both intention and
behavior. The findings may be helpful in developing tuberculosis education and
screening programs for Mexican migrant farmworkers.
PMID- 10667626
TI - Gender and short-term recovery from cardiac surgery.
AB - BACKGROUND: There has been a lack of agreement regarding whether women have
poorer outcomes than men following cardiac surgery. OBJECTIVES: To examine the
effect of gender on early recovery from cardiac surgery. METHOD: Using a
prospective descriptive design, 60 men and 60 women who had coronary artery
bypass and/or valve surgery completed the study by participating in interviews in
the immediate preoperative period and monthly through the third postoperative
month. Measures of life quality, life satisfaction, expected/perceived recovery,
functional status, global health status, and social support were examined.
RESULTS: Preoperatively, women were more functionally limited (p = 0.019), and
reported lower life satisfaction (p = 0.001) and social support (p = 0.006), than
men. At 3 months postoperatively, there were few significant differences in
outcome measures though women continued to report lesser social support (p =
0.002); women realized significantly greater improvement than men in functional
status (p = 0.008); and neither age nor gender consistently predicted recovery.
CONCLUSIONS: Recent studies focusing on gender differences in cardiac surgery
recovery indicate fewer differences between men and women than once thought.
However, the differences identified in this study (women's significantly greater
improvement in functional status, lesser social support, and differences in the
nature of work to which women return following their surgery) warrant concern and
attention in clinical practice.
PMID- 10667627
TI - Leadership styles across hierarchical levels in nursing departments.
AB - BACKGROUND: Some researchers have reported on the cascading effect of
transformational leadership across hierarchical levels. One study examined this
effect in nursing, but it was limited to a single hospital. OBJECTIVES: To
examine the cascading effect of leadership styles across hierarchical levels in a
sample of nursing departments and to investigate the effect of hierarchical level
on the relationships between leadership styles and various work outcomes.
METHODS: Based on a sample of eight hospitals, the cascading effect was tested
using correlation analysis. The main sources of variation among leadership scores
were determined with analyses of variance (ANOVA), and the interaction effect of
hierarchical level and leadership styles on criterion variables was tested with
moderated regression analysis. RESULTS: No support was found for a cascading
effect of leadership across hierarchical levels. Rather, the variation of
leadership scores was explained primarily by the organizational context.
Transformational leadership had a stronger impact on criterion variables than
transactional leadership. Interaction effects between leadership styles and
hierarchical level were observed only for perceived unit effectiveness.
CONCLUSIONS: The hospital's structure and culture are major determinants of
leadership styles.
PMID- 10667628
TI - Preventing smoking relapse in postpartum women.
AB - BACKGROUND: Although many women quit smoking during pregnancy, the majority
resume smoking shortly after giving birth. OBJECTIVES: To test a program to
prevent smoking relapse in the postpartum period by comparing the rates of
continuous smoking abstinence, daily smoking, and smoking cessation self-efficacy
in treatment and control groups. METHODS: In a randomized clinical trial, nurses
provided face-to-face, in-hospital counseling sessions at birth, followed by
telephone counseling. The target population included women who quit smoking
during pregnancy and who gave birth at one of five hospitals. The 254
participating women were interviewed 6 months after delivery and assessed
biochemically to determine smoking status. RESULTS: The 6-month continuous
smoking abstinence rate was 38% in the treatment group and 27% in the control
group (odds ratio [OR] = 1.63, 95% confidence interval [CI] .96 - 2.78).
Significantly more control (48%) than treatment (34%) group participants reported
smoking daily (OR = 1.80, 95% CI = 1.08 - 2.99). Smoking cessation self-efficacy
did not vary significantly between the groups. CONCLUSIONS: Smoking cessation
interventions focusing on the prenatal period have failed to achieve long-term
abstinence. Interventions can be strengthened if they are extended into the
postpartum period.
PMID- 10667629
TI - Detecting and explicating interactions in categorical data.
PMID- 10667630
TI - Exploring subject-related interactions in repeated measures data using three-mode
principal components analysis.
PMID- 10667631
TI - Epidemiologic study of pulmonary obstruction in workers occupationally exposed to
ethyl and methyl cyanoacrylate.
AB - The association between pulmonary obstruction (e.g., asthma) and occupational
exposure to methyl cyanoacrylate (MCA) and ethyl cyanoacrylate (ECA) was examined
in an occupational cohort of 450 persons at an adhesive production facility in
Puerto Rico. Employee medical records containing information on physical
examinations and pulmonary function tests (PFTs), as well as occupational
histories, on each employee over a period of about 17 yr and industrial hygiene
measurements were evaluated. The cohort analysis was based on a Cox proportional
hazards model. Workers exposed to ECA or MCA were compared to workers unexposed
to these chemicals with respect to their risk of becoming an "incident case." An
"incident case" was defined as any person whose PFTs were normal at the time of
employment, but later demonstrated an obstructive pattern, which was defined as a
decline in the ratio of forced expiratory volume exhaled in 1 s to forced vital
capacity (FEV1/FVC) below 70%. A separate case-control analysis was also
conducted that compared "suspected cases," defined as all those whose PFTs ever
demonstrated an obstructive pattern (e.g., asthma), to persons whose PFTs
remained within normal limits throughout their employment with respect to their
past peak and cumulative exposures to cyanoacrylates. All of these analyses
showed no evidence that exposure to average short-term concentrations of ECA or
MCA of less than 0.5 ppm and occasional daily peak exposures of at least 1.5 ppm
(usually 10 min or less), with occasional higher concentrations during spills,
were associated with an increased risk of pulmonary obstruction. However, the
study suggested that persons occupationally exposed to cyanoacrylates were more
likely to have some reversible eye or upper airway irritation than persons who
were unexposed.
PMID- 10667632
TI - Alveolar macrophage cytokine production in response to air particles in vitro:
role of endotoxin.
AB - The interaction of air particles and alveolar macrophages (AMs) may result in the
release of proinflammatory cytokines. Normal mouse AMs were treated with
concentrated air particle (CAPs) suspensions in vitro. After 5 h, cytokine
release [macrophage inflammatory protein-2 (MIP-2) and tumor necrosis factor
alpha (TNF-alpha)] and phagocytosis of ambient air particles were measured. CAPs
samples collected from urban air (Boston) on different days were used. The CAPs
samples and their soluble and solid components caused significant MIP-2 and TNF
alpha production. Variability in the potency of samples collected on different
days was observed. Trace endotoxin was measured in CAPs samples (EU/mg: 2.3 +/-
0.7, mean +/- SE, n = 10). A majority of biologic activity (cytokine induction)
and endotoxin content was associated with the solid components. Neutralization of
endotoxin by polymyxin B abrogated >80% of TNF-alpha induction by CAPs samples,
but inhibited MIP-2 production by only approximately 40%. The trace endotoxin
present in CAPs caused much more MIP-2 production than predicted by concentration
alone (28 +/- 8-fold increase, n = 9), indicating synergistic interaction with
other AM-activating components of the particles. Data suggest that low levels of
endotoxin may interact with air particles to activate lung macrophages.
PMID- 10667633
TI - Effect of CYP2E1 induction by ethanol on the immunotoxicity and genotoxicity of
extended low-level benzene exposure.
AB - Potential additive effects of ethanol consumption, a common life-style factor,
and low-level benzene exposure, a ubiquitous environmental pollutant, were
investigated. Ethanol is a potent inducer of the cytochrome P-450 2E1 (CYP2E1)
enzyme, which bioactivates benzene to metabolites with known genotoxicity and
immunotoxicity. A liquid diet containing 4.1% ethanol was used to induce hepatic
CYP2E1 activity by 4-fold in female CD-1 mice. Groups of ethanol-treated or pair
fed control mice were exposed to benzene or filtered air in inhalation chambers
for 7 h/d, 5 d/wk for 6 or 11 wk. The initial experiment focused on
immunotoxicity endpoints based on literature reports that ethanol enhances high
dose benzene effects on spleen, thymus, and bone marrow cellularity and on
peripheral red blood cell (RBC) and white blood cell (WBC) counts. No
statistically significant alterations were found in spleen lymphocyte
cellularity, subtype profile, or function (mitogen-induced proliferation,
cytokine production, or natural killer cell lytic activity) after 6 wk of ethanol
diet, 0.44 ppm benzene exposure, or both. This observed absence of
immunomodulation by ethanol alone, a potential confounding factor, further
validates our previously established murine model of sustained CYP2E1 induction
by dietary ethanol. Subsequent experiments involved a 10-fold higher benzene
level for a longer time of 11 wk and focused on genotoxic endpoints in known
target tissues. Bone marrow and spleen cells were evaluated for DNA-protein cross
links, a sensitive transient index of genetic damage, and spleen lymphocytes were
monitored for hprt-mutant frequency, a biomarker of cumulative genetic insult. No
treatment-associated changes in either genotoxic endpoint were detected in
animals exposed to 4.4 ppm benzene for 6 or 11 wk with or without coexposure to
ethanol. Thus, our observations suggest an absence of genetic toxicity in CD-1
mice exposed to environmentally relevant levels of benzene with or without CYP2E1
induction.
PMID- 10667634
TI - Toxaphene is antiestrogenic in a human breast-cancer cell assay.
AB - Toxaphene is a complex mixture of chlorinated bornanes, bornenes, and bornadienes
and was a heavily used insecticide in the United States until its use was
restricted in 1982. There are conflicting reports regarding the potential for
toxaphene to induce estrogenic responses in human and nonhuman animals. Due to
the public concern over environmental estrogens, the estrogenicity of toxaphene
was examined in a human breast-cancer cell assay, the MCF-7 focus assay, which is
based on in vitro postconfluent cell proliferation and tissue restructuring. In
this assay, 0.1-1 nM 17beta-estradiol (E2) produces maximum postconfluent
proliferation and formation of multicellular nodules or foci. Toxaphene was also
tested for its ability (1) to bind the estrogen receptor (ER) in a competitive
binding assay using recombinant human ERalpha (rhER) and in a whole-cell
competitive ER binding assay, and (2) to alter the catabolism of E2 in MCF-7 cell
cultures. Results from the MCF-7 focus assay showed: (1) Toxaphene alone was not
estrogenic between the concentrations of 0.5 nM and 10 microM, (2) toxaphene in
binary combinations with chlordane, dieldrin, or endosulfan (alpha or beta) was
not estrogenic, and (3) toxaphene was weakly antiestrogenic (it reduced the
number of foci induced by 0.1 nM and 0.01 nM E2). Results from the competitive
binding assays showed that (1) toxaphene alone did not bind rhER or ER in MCF-7
cells, and (2) toxaphene in binary combinations with other pesticides did not
bind rhER. Results from the growth assay and radiometric analysis of E2
catabolism showed that (1) toxaphene did not alter the growth rate of MCF-7 cell
cultures over 13 d, and (2) toxaphene did not alter the catabolism of E2. In
conclusion, results from the MCF-7 focus assay demonstrate that toxaphene is
weakly antiestrogenic rather than estrogenic.
PMID- 10667635
TI - Edema in chronic venous insufficiency and the effect of modern pharmacotherapy.
PMID- 10667636
TI - Implications of the lymphatic system in CVI-associated edema.
AB - Lymph drainage is intimately linked with venous drainage in health and disease.
Evidence exists to support the view that lymphatics frequently fail in venous
disease, particularly in its advanced stages. The implications of this are to
increase the risk of infection and the amount of edema, events which can only
further the morbidity of venous disease.
PMID- 10667637
TI - Edema and leg volume: methods of assessment.
AB - Various techniques may be used to assess leg edema. The value of these
investigations has been discussed in depth in the consensus statement made in
Vaux de Cernay in 1997 and supported by Servier Research Group. These techniques
can be classified into three groups: The most simple is leg circumference
measurement, which can be assessed by a tape measure, or more rigorously with a
Leg-O-Meter. This device is a cheap and reproducible method that has been
validated and that takes into account the height at which the circumference has
been measured. However, circumference measurement is not always correlated with
leg (including foot) volume measurement. The second group of techniques assess
leg volume. The most simple method is water displacement volumetry, which has
been validated in terms of reproducibility. Several other devices have been used:
optoelectronic methods, computed tomography, magnetic resonance imaging (high
resolution), dual X-ray absorptiometry. These methods are expensive and not all
of them have been validated, but these might be the future investigations of
choice. Some other investigations assess immediate variations in volume such as
water displacement using dynamic foot volumetry, rheoplethysmography, strain
gauge plethysmography, and air plethysmography. The assessment made by these
methods (using postural, dynamic, or compressive maneuvers) is more an assessment
of the venomuscular pump and/or venous outflow than volume assessment. In
conclusion, edema, an early and frequent sign of chronic venous insufficiency
(CVI), can be precisely measured by several methods. This measurement can be
considered one of the most objective ways of assessing treatment efficacy in CVI
associated edema.
PMID- 10667639
TI - Pharmacologic aspects of a phlebotropic drug in CVI-associated edema.
AB - Several phlebotropic drugs, or edema-protecting drugs, are available, the most
important of which are found in the gamma-benzopyrone family (flavonoids). gamma
Benzopyrones can be plant extracts, semisynthetic preparations, or synthetic
preparations. This family is divided into two different groups: flavones and
flavonols, and flavanes (flavanones). The flavone group contains various types of
molecule and includes diosmin. Here we discuss the pharmacologic aspects in edema
associated with chronic venous insufficiency (CVI) of one of the reference
phlebotropic drugs, micronized purified flavonoid fraction (MPFF), a
semisynthetic preparation from the diosmin group, which represents the latest
improvement in flavonoid formulation. Before we detail the pharmacologic aspects,
a brief summary of the pathophysiology of edema in CVI is necessary. Several
factors are implicated: the veins, which create the conditions favorable to
edema; the microcirculation, which is the site of fluid transfer into the
interstitial tissue; and the lymphatics, which have a limited possibility to
reduce edema. Major discoveries are currently being made in CVI and the
microcirculation. Results of studies show that MPFF decreases capillary
permeability and increases capillary resistance, which could partly be explained
by inhibition of leukocyte activation, migration, and adhesion. This inhibition
is linked to a significant decrease in plasma levels of endothelial adhesion
molecules (VCAM-1 and ICAM-1) after MPFF treatment. Thus, the CVI-induced damage
to the microcirculation is counteracted by MPFF. The lymphatic system is also
improved by MPFF treatment. The lymphagogue activity of MPFF has been
demonstrated in experimental animal models and confirmed by microlymphographic
measurement in patients suffering from severe CVI. The pharmacologic activity of
MPFF in lymphedema was observed in a study using an animal model of acute
lymphedema and in a study in patients with upper limb lymphedema secondary to
breast cancer treatment. All these findings point to the importance of acting on
each factor involved in the formation and maintenance of edema. This
pharmacologic activity is indeed reflected by the clinical efficacy on edema
observed during treatment with MPFF.
PMID- 10667638
TI - Management of venous edema: insights from an international task force.
AB - An International Task Force made up of a panel of 16 experts has reviewed and
objectively evaluated all aspects of chronic venous disease of the leg (CVDL).
All available publications on CVDL from 1983 to 1997 were identified through
computerized search in Medline and by a manual search. Next, three different
screenings were performed in order to select only relevant papers providing a
level of scientific evidence that was considered moderate to strong. Final
conclusions and further therapeutic recommendations were made based on these
publications. Medication, compression, local therapy, sclerotherapy, and surgery
are the accepted available therapeutic options for CVDL. For edema, the following
recommendations can be made: edema is an early sign of CVDL, but before starting
any treatment, nonvenous causes of edema should be excluded. Medication and
compression are the therapeutic options for edema that are accepted by the Task
Force. Evaluation of their efficacy is based on objective measures of edema.
Several well-conducted, placebo-controlled trials have shown efficacy of drugs
such as micronized purified flavonoid fraction, rutosides, calcium dobesilate,
and coumarin rutin. Graduated compression stockings have been shown to be
effective; compression needs to be exerted at least at 35 mm Hg. Bandages, if
properly applied, both fixed and stretched, can produce favorable results.
Sclerotherapy or surgery is not indicated unless there is saphenofemoral or
saphenopopliteal reflux. In the absence of such reflux or following deep venous
thrombosis, there is no evidence to support sclerotherapy or surgery.
PMID- 10667640
TI - Clinical efficacy of micronized purified flavonoid fraction (MPFF) in edema.
AB - Swelling is one of the most frequent complaints of patients in daily clinical
practice; leg edema is its objective confirmation. It can be associated with
several diseases. Micronized purified flavonoid fraction (MPFF) is a phlebotropic
drug commonly used to treat the signs and symptoms associated with chronic venous
insufficiency (CVI). It has confirmed its clinical efficacy in different groups
of patients suffering from edema: idiopathic cyclic edema, CVI-associated edema,
postmastectomy lymphedema and might be beneficial in some of drug-induced edema.
In a double-blind, placebo-controlled, randomized study including 30 outpatients
suffering from idiopathic cyclic edema syndrome, MPFF 1000 mg/day for 6 weeks,
normalized the capillary permeability, assessed by the Landis isotope test, in 3
out of 4 patients (p=0.01). The decrease in capillary hyperpermeability led to a
clinically significant decrease in weight and edema. In 200 patients with
functional or organic venous insufficiency of the lower limbs, a double-blind,
placebo-controlled, randomized study with MPFF 1000 mg/day for 2 months provided
strong evidence of a marked improvement in symptoms and signs. A significant
reduction in supramalleolar edema (assessed by circumference measurement) was
observed, whatever the origin of CVI: functional or organic. MPFF efficacy was
also demonstrated in another randomized, multicenter controlled trial in 320
patients suffering from chronic venous insufficiency. In this study, a
significant decrease in circumference of the most affected leg was observed after
2 months of treatment (p<0.001), whatever the schedule of administration of MPFF
(1000 mg once daily or bid). The benefit of MPFF on edema has been further
confirmed by the volometer technique (opto-electronic measuring system) which was
performed in a population of 30 patients suffering from CVI and treated by MPFF
1000 mg/day over a 6-week period. The mean volume of the more affected lower leg
decreased significantly after a 6-week period of treatment, correlating to a
significant improvement in clinical symptoms. MPFF has been also tested on
another type of edema, upper limb lymphedema secondary to mastectomy, during a
double-blind, placebo-controlled, randomized study in 104 patients. MPFF 1000
mg/day improved all lymphoscintigraphic parameters such as half-life and
clearance of the labelled colloid. With regard to evolution of lymphedema volume,
a tendency in favor of MPFF was observed in the subgroup of patients with more
severe lymphedema. Based on its action on capillary hyperpermeability, MPFF has
been used with attractive results when combined with classic treatment for a
pilot study carried out in patients with advanced breast cancer (n=21) or ovarian
carcinoma (n=3), treated with docetaxel, which causes severe edema as a side
effect, even when associated with corticoids. Further trials are under way to
assess the possible benefit of MPFF in such patients. These results in different
types of edema confirm that, by acting on all parameters involved in edema,
veins, lymphatics, and microcirculation, MPFF represents a drug of choice for
treating CVI-associated edema.
PMID- 10667641
TI - RELIEF study: first consolidated European data. Reflux assEssment and quaLity of
lIfe improvement with micronized Flavonoids.
AB - The RELIEF study (Reflux assEssment and quality of life improvement with
micronized Flavonoids in chronic venous insufficiency [CVI]) is a prospective,
controlled, multicenter, international study performed in patients with or
without venous reflux. This study was conducted between March 1997 and December
1998 in 23 countries worldwide with the participation of more than 10,000
patients suffering from CVI. The European countries, the subject of this report,
were represented by the Czech and Slovak Republics, Hungary, Poland, Russia, and
Spain. The principal aims of the study were: 1. To validate the first quality-of
life scale specific to chronic venous insufficiency (CMVIQ) in different
languages and to assess the evolution of quality of life in patients suffering
from CVI, with or without venous reflux, treated with micronized purified
flavonoid fraction (MPFF*) (1,000 mg/day). 2. To collect international
epidemiologic data on venous reflux assessed with pocket Doppler and
photoplethysmography. 3. To assess the evolution of symptoms and signs with a
specific emphasis on edema through validated Leg-O-Meter measurement (heaviness,
pain, cramps, sensation of swelling, edema) in patients suffering from CVI and
treated with MPFF, 1,000 mg/day, during 6 months. The first country-by-country
statistical analysis and the European consolidated analysis are now available.
The CIVIQ questionnaires adapted to each participating country have been
validated with highly significant validity and reproducibility (p<0.0001). All
dimensions have demonstrated a highly significant and evolving improvement during
the study. The results show several interesting findings concerning the
epidemiologic data and, of these, two were particularly interesting: - More than
50% of patients suffering from CVI (class 0 to 4 of the CEAP classification) were
reflux-free, which means that they were suffering from functional CVI. Patient
distribution between the different classes of the CEAP classification changed in
a statistically significant manner after 6 months' treatment with MPFF; the
number of patients in the more severe classes decreased to the benefit of the
less severe classes. Symptoms such as pain, leg heaviness, sensation of swelling,
and cramps were significantly improved (p=0.0001). This was associated with a
significant decrease in edema, when present, measured by leg circumferences with
the Leg-O-Meter (p=0.0001). In conclusion, the European results of the RELIEF
study showed the perfect validity and reproducibility of CIVIQ questionnaire
adaptations, and the positive progression of quality-of-life scores on MPFF
treatment. This progression was paralleled by clinical improvement of patients
reflected not only by assessment of CVI symptoms and signs but also by evolution
of the CEAP classification.
PMID- 10667642
TI - The relative influence of lesion length and other stenosis morphologies on
procedural success of coronary intervention.
AB - As coronary interventional technology improves, the influence of lesion length
(LL) on procedural success and device selection may vary. Thus, the authors
prospectively analyzed 957 consecutive coronary interventions (CI) in 1,404
stenoses to ascertain the influence of lesion length on CI outcome. Stenosis
morphology was prospectively classified by the AHA/ACC criteria. LL was analyzed
both as dichotomous (S: < 10 mm, L: > 10 mm) variables and by the three-tiered
AHA/ACC criteria (I: < 10 mm, II: 10-20 mm, III: > 20 mm). There was a
significant univariate relationship between CI success and S stenosis (S: 95.8%
vs L: 91.8%, p = 0.002 and I: 96.0%, II: 91.7%, III: 89.3%). Numerous
interrelationships involving the morphologic characteristics were noted: lesion
morphologies associated with S lesions were concentric (p = 0.0001) and had
smooth contour (p = 0.0001), ostial location (p = 0.05) and little calcification
(p = 0.0007), while irregular contour (p=0.0001), calcification (p=0.0076),
eccentric (p=0.0001), thrombus (p = 0.0001), recent (p = 0.0001) or chronic (p =
0.001) total occlusion were associated with L lesions. When these relationships
were taken into account by multiple logistic regression analysis, lesion length
was not predictive of procedural outcome (p = 0.099). One morphologic type was
associated with increased CI success: irregular contour (p = 0.022); recent (p <
0.0001) or chronic (< 0.0001) occlusions were associated with decreased CI
success. Another factor considered was device selection: S lesions were
associated with greater balloon angioplasty usage (p = 0.002), whereas more
coronary stents (p = 0.024) and rotoblator (p = 0.018) devices were used in L
lesions. More balloon angioplasty was performed in concentric (p < 0.0001)
lesions; interventional devices were employed more often in eccentric (p <
0.0001) and irregular lesions (p < 0.0001). More complications were noted in
lesions with thrombus (p = 0.0002), but lesion length was not predictive (p =
NS). Lesion length is not a significant predictor of procedural success when
adjusted for other lesion morphologies in the modern interventional era. The
availability of new devices has improved the results in longer lesions since the
AHA/ACC criteria were originally proposed.
PMID- 10667643
TI - Risk factors of atherosclerosis and aortic pulse wave velocity.
AB - Aortic pulse wave velocity (PWV) is a noninvasive technique that can estimate
aortic stiffness or organic change quantitatively. The authors examined the
correlation between age and the PWV value in 113 subjects and also examined the
relationship between atherosclerotic associated diseases and PWV. A positive
correlation was observed between age and the PWV value. No significant difference
was found in the PWV value between groups with and without risk factors of
atherosclerosis. No significant difference was observed in the PWV value between
groups with and without a history of atherosclerotic disease.
PMID- 10667645
TI - Enalapril and losartan augment endogenous nitric oxide release in Takayasu's
arteritis--a case report.
AB - Prognosis in Takayasu's arteritis is limited owing to renovascular hypertension.
The authors report a patient with Takayasu's arteritis who had been unilaterally
nephrectomized and presented with malignant hypertension due to renal artery
stenosis. Hypertension was refractory to conventional antihypertensive treatment,
and stenosis was not accessible by interventional angioplasty. Initiation of
enalapril and losartan therapy was successful in improving blood pressure without
deterioration of renal function due to ischemic failure. Antihypertensive
treatment resulted in dramatically stimulated endogenous nitric oxide (NO)
synthesis, while elevated plasma endothelin-1 levels were unchanged. Renovascular
hypertension in Takayasu's arteritis is associated with an imbalance of
vasoconstrictor peptide endothelin-1 and vasodilator peptide NO. Successful
treatment of hypertension by enalapril or losartan results in improved endogenous
NO synthesis, which putatively counterbalances excessive vasoconstrictor actions
and may retard the progression of renal failure.
PMID- 10667644
TI - Clinical assessment of vascular thrombosis using indium-111 platelet
scintigraphy.
AB - The authors reviewed the clinical value of platelet scintigraphy by using
autologous platelets labeled with indium-111-oxine to detect thrombotic activity
at vascular thrombosis sites. Thirty-nine patients with deep vein thrombosis, 28
with arteriosclerosis obliterans, and 10 with pulmonary embolism were the
subjects of this study. Platelet accumulation on scintigrams had a tendency to
correlate with aggravation of acute thrombotic symptoms in deep vein thrombosis
and arteriosclerosis obliterans. In addition, appropriate thrombolytic and
anticoagulant therapy resulted in reduced platelet accumulation in conjunction
with improvement of acute symptoms. On the other hand, this type of scintigraphy
was not so sensitive for assessment of pulmonary embolism. Platelet scintigraphy
could facilitate the assessment of thrombotic activity and might be useful for
determining the optimal indication of thrombolytic and anticoagulant therapy for
acute vascular thrombosis.
PMID- 10667646
TI - Lamellar bone formation in an atherosclerotic plaque of the carotid artery, with
a review of histogenesis--a case report.
AB - Longer existing atherosclerotic lesions may contain calcifications; lamellar bone
rarely develops within them. A 59-year-old man was referred with a progressive
stroke. A high-grade stenosis of the left common carotid artery, formed by an
ulcerating atherosclerotic plaque with a free-floating thrombus, was detected on
angiography. An urgent endarterectomy was performed. Surprisingly this plaque
contained pieces of lamellar bone, proved by histologic examination.
PMID- 10667647
TI - Successful percutaneous balloon mitral valvuloplasty using left ventricular
pressure as a guide to cross the mitral valve--a case report.
AB - Percutaneous balloon mitral valvuloplasty (PBMV) provides an effective
alternative to surgery in a selective group of patients with symptomatic mitral
stenosis. The Inoue balloon technique involves transseptal catheterization
followed by catheter manipulation to cross the mitral valve. The authors describe
a case of successful percutaneous balloon mitral valvuloplasty in a patient with
severe mitral stenosis and pulmonary hypertension. Left ventricular systolic
pressure was used as a guide to locate and to advance the balloon catheter across
the mitral valve. This technique to cross the mitral valve has not been reported
in the literature.
PMID- 10667648
TI - The Fleming Unified Theory of Vascular Disease: a link between atherosclerosis,
inflammation, and bacterially aggravated atherosclerosis (BAA)
PMID- 10667649
TI - Acute generalized urticaria leading to acute myocardial infarction.
PMID- 10667650
TI - Ultra high resolution imaging of the human head at 8 tesla: 2K x 2K for Y2K.
AB - PURPOSE: To acquire ultra high resolution MRI images of the human brain at 8
Tesla within a clinically acceptable time frame. METHOD: Gradient echo images
were acquired from the human head of normal subjects using a transverse
electromagnetic resonator operating in quadrature and tuned to 340 MHz. In each
study, a group of six images was obtained containing a total of 208 MB of
unprocessed information. Typical acquisition parameters were as follows: matrix =
2,000 x 2,000, field of view = 20 cm, slice thickness = 2 mm, number of
excitations (NEX) = 1, flip angle = 45 degrees, TR = 750 ms, TE = 17 ms, receiver
bandwidth = 69.4 kHz. This resulted in a total scan time of 23 minutes, an in
plane resolution of 100 microm, and a pixel volume of 0.02 mm3. RESULTS: The
ultra high resolution images acquired in this study represent more than a 50-fold
increase in in-plane resolution relative to conventional 256 x 256 images
obtained with a 20 cm field of view and a 5 mm slice thickness. Nonetheless, the
ultra high resolution images could be acquired both with adequate image quality
and signal to noise. They revealed numerous small venous structures throughout
the image plane and provided reasonable delineation between gray and white
matter. DISCUSSION: The elevated signal-to-noise ratio observed in ultra high
field magnetic resonance imaging can be utilized to acquire images with a level
of resolution approaching the histological level under in vivo conditions.
However, brain motion is likely to degrade the useful resolution. This situation
may be remedied in part with cardiac gating. Nonetheless, these images represent
a significant advance in our ability to examine small anatomical features with
noninvasive imaging methods.
PMID- 10667651
TI - Thoracic involvement of systemic lupus erythematosus: clinical, pathologic, and
radiologic findings.
AB - Thoracic involvement occurs more frequently in systemic lupus erythematosus than
in any other connective tissue diseases, and more than half of patients with the
disease suffer from the involvement. Primary intrathoracic manifestations include
pleural disease (effusions and/or thickening), acute lupus pneumonitis, subacute
interstitial lung disease including bronchiolitis obliterans organizing pneumonia
and non-specific interstitial pneumonia with fibrosis, chronic interstitial lung
disease of usual interstitial pneumonia, pulmonary hemorrhage, pulmonary vascular
disease, small airway disease of bronchiolitis obliterans, and pulmonary arterial
hypertension. Secondary intrathoracic manifestations include atelectasis due to
diaphragmatic dysfunction, opportunistic pneumonia, drug and oxygen toxicity,
aspiration, and pleuropulmonary consequences of cardiac and renal failure.
PMID- 10667652
TI - CT appearance of implanted esophageal stents.
AB - Three different types of esophageal stents, the Z-stent, Ultraflex, and Wall
stent, exhibit different shapes on CT, which may suggest a difference in the
radial forces applied by each of the stents. CT is useful for displaying the
relationship between an esophageal stent and adjacent structures and
complications.
PMID- 10667653
TI - Pulmonary fat embolism syndrome: CT findings in six patients.
AB - PURPOSE: Our purpose is to describe the CT findings in pulmonary fat embolism
syndrome (FES). METHOD: Chest radiographs and CT scans of six patients with
pulmonary FES were reviewed. Initial and follow-up CT findings were noted, and
the extent of CT abnormalities was correlated with partial pressure of arterial
oxygen (PaO2). RESULTS: Focal areas of consolidation or ground-glass opacity and
nodules were seen in all patients, predominantly in the upper lobes of the lungs.
Association between these opacities and pulmonary vessels was indicated in three
patients. In the lower lobes of all patients, gravity-dependent opacities
predominated. Diffuse ground-glass opacity was noted in five patients. Follow-up
CT scans showed rapid improvement in three patients, but the gravity-dependent
opacity progressed. The extent of CT abnormalities correlated positively with
PaO2 (r = 0.8, p < 0.05). CONCLUSION: CT findings reflect the pathophysiology of
this syndrome, which differs from that of simple capillary permeability pulmonary
edema.
PMID- 10667654
TI - B-cell lymphoma of bronchus-associated lymphoid tissue (BALT): CT features in 10
patients.
AB - PURPOSE: The purpose of this work was to describe the CT findings of
pathologically confirmed bronchus-associated lymphoid tissue (BALT) lymphoma in
10 patients. METHOD: The CT examinations of 10 patients with pathologically
proven BALT lymphoma were reviewed retrospectively by two radiologists. Evaluated
findings included number and distribution of lesions. We also assessed other CT
findings such as presence of airspace consolidation, nodules, ground-glass
attenuation, bubble-like radiolucencies, air bronchogram, bronchial dilatation,
and lymphadenopathy. RESULTS: Pulmonary lesions were revealed as airspace
consolidation in six patients (60%) and nodule(s) in six (60%). Multiplicity of
disease was seen in seven patients (70%) and bilateral lung lesions in six (60%).
Areas of ground-glass attenuation were seen in seven patients (70%). Bubble-like
radiolucencies were present in five patients (50%) and air bronchogram in nine
(90%). Findings of bronchial dilatation and lymphadenopathy were seen in three
patients (30%). CONCLUSION: BALT lymphomas usually appear as airspace
consolidation or nodules with air bronchogram or adjacent ground-glass
attenuation at CT. These findings are similar to previous descriptions of
pseudolymphomas. Multiple bilateral lesions are common in BALT lymphoma. Bubble
like radiolucencies have not been described previously and can be an additional
finding of BALT lymphoma.
PMID- 10667655
TI - Primary tumors and mediastinal lymph nodes after neoadjuvant concurrent
chemoradiotherapy of lung cancer: serial CT findings with pathologic correlation.
AB - PURPOSE: The purpose of this work was to describe the changes of primary tumor
and mediastinal lymph nodes on CT after neoadjuvant concurrent chemoradiotherapy
and to correlate the CT findings with pathology. METHOD: Twenty-one consecutive
patients [N2 disease (n = 19) or resectable T4 and N2 disease (n = 2)] with non
small cell lung cancer underwent neoadjuvant concurrent chemoradiotherapy.
Changes of primary tumor and mediastinal nodes before and after the therapy were
assessed using CT. The CT findings were correlated with pathologic findings.
RESULTS: With neoadjuvant therapy, decrease in T stage was achieved in 9 of 21
(43%) patients on CT. On pathology, the remaining tumor consisted mostly of
fibrosis and necrosis with little proportion of viable tumor cells (mean volume
17%, range 0-55%). Decrease in nodal stage was achieved in 14 of 21 (67%)
patients on pathologic examination. Seven patients had cancer cells in
mediastinal lymph nodes: in 6 of 9 (67%) patients with adenocarcinoma and 1 of 12
(8%) patients with squamous cell carcinoma (p = 0.016). CONCLUSION: With
neoadjuvant concurrent chemoradiotherapy, the remaining tumor consists mostly of
fibrosis or necrosis. Decreased nodal stage on pathology is achieved especially
in patients with N2 disease of squamous cell carcinoma. The CT findings of the
tumor and mediastinal nodes are not helpful in predicting the pathology after the
therapy.
PMID- 10667656
TI - Serial high resolution CT findings in nonspecific interstitial
pneumonia/fibrosis.
AB - PURPOSE: The purpose of this work was to evaluate the radiographic and serial
high resolution CT (HRCT) findings in patients with nonspecific interstitial
pneumonia/ fibrosis (NSIP). METHOD: We identified 15 patients with biopsy-proven
NSIP. Radiography and initial and follow-up CT findings were reviewed. RESULTS:
Predominant radiographic findings were bilateral infiltrates distributing in the
middle and lower lung zones and decreased lung volumes. At initial CT,
predominant patterns were peribronchovascular interstitial thickening (n = 6),
parenchymal bands (n = 8), intralobular interstitial thickening (n = 12), and
traction bronchiectasis (n = 14). Mixed pattern of ground-glass opacity and
consolidation (n = 11) were predominant findings of increased lung opacity. At
follow-up CT in 14 cases, the abnormalities had disappeared completely in 3,
improved in 9, persisted in 1, and worsened in 1. CONCLUSION: The pulmonary
abnormalities observed in NSIP on HRCT can disappear or be diminished in most
cases after corticosteroid therapy. Intralobular interstitial thickening and
traction bronchiectasis, which have been considered to be indicators of
irreversible fibrosis, also show favorable responses.
PMID- 10667657
TI - Blood clots mimicking peripheral intrabronchial tumors in patients with
hemoptysis: CT and bronchoscopic findings.
AB - We report radiographic and clinical findings in two cigarette-smoking patients
presenting with hemoptysis. On CT, both patients had peripheral intrabronchial
masses together with parenchymal opacities. Bronchoscopy revealed the
intrabronchial masses to be blood clots and the parenchymal opacities to
correspond to areas of parenchymal hemorrhage. Our cases are novel in that both
bronchial and parenchymal sequelae of hemorrhage were simultaneously visualized
by CT. Also, our findings suggest that bronchial blood clots should be included
in the differential diagnosis of peripheral intrabronchial lesions, notably in
patients presenting with hemoptysis.
PMID- 10667658
TI - Carbamate poisoning: high resolution CT and pathologic findings.
AB - Carbamate insecticides are commonly used agricultural insecticides. The major
cause of morbidity and mortality in acute carbamate poisoning is respiratory
failure associated with pulmonary edema. Although carbamate poisoning is well
recognized in the clinical literature, the findings of high resolution CT (HRCT)
with carbamate have not been reported. We report the radiographic and HRCT
findings of a patient with acute carbamate poisoning who had pathologically
proven interstitial pneumonitis after resolution of initial pulmonary edema.
PMID- 10667659
TI - High FDG uptake in a schwannoma: a PET study.
PMID- 10667660
TI - "Bridging vascular sign" in the MR diagnosis of exophytic uterine leiomyoma.
AB - PURPOSE: The purpose of this study was to evaluate the usefulness of the
"bridging vascular sign" in the diagnosis of an exophytic uterine leiomyoma and
differentiation of a uterine leiomyoma from some other mass arising in the adnexa
on pelvic MRI. METHOD: Of 52 women with a pelvic mass in whom pelvic MRI was
performed to determine its origin, 26 women with surgicopathologically proven
leiomyomas were included in this study. The other 26 women were proved to have
indeterminate adnexal masses such as tuboovarian abscess, endometrioma, fibroma,
etc. To obtain axial/ sagittal T2-weighted and pre-/postcontrast T1-weighted
images, a 1.5 T unit was used. Positive bridging vascular sign was defined as the
presence of curvilinear tortuous signal void vascular structures crossing and/or
between the uterus and the pelvic mass. For the presence or absence of this sign,
the percentages of patients in each group were calculated and compared. RESULTS:
Bridging vascular sign was present in 20 (76.9%) of 26 cases of leiomyomas but in
no cases of other adnexal masses. Only exophytic uterine leiomyomas had this
sign. CONCLUSION: Bridging vascular sign on MRI may be a useful radiologic sign
in the diagnosis and differentiation of an exophytic uterine leiomyoma from some
other mass arising in the adnexa.
PMID- 10667661
TI - Focal nodular hyperplasia: natural course observed with CT and MRI.
AB - PURPOSE: The purpose of this work was to assess the natural course of biopsy
proven focal nodular hyperplasia (FNH). METHOD: Eighteen biopsy-proven FNHs in 14
patients (12 women and 2 men) who were followed for at least 6 months with CT
and/or MRI were included in the study. The volume of the lesions was calculated
twice by two observers using the summation of areas method. Intra- and
interobserver variability was assessed by intraclass correlation coefficients.
Longitudinal data analysis was performed with generalized estimating equations.
RESULTS: The volume of FNH was stable in 6 cases, decreased in 10 cases, and
increased in 2 cases. Intra- and interobserver variability in size measurements
was 5-10%. Intraclass correlation coefficients were >0.992. Longitudinal data
analysis showed that there was a general trend of lesion regression. CONCLUSION:
Long-term follow-up and objective measurements performed in patients with biopsy
proven lesions show that the natural course of FNH is variable. In particular,
lesion regression is not rare.
PMID- 10667662
TI - Normal enhancement of the small bowel: evaluation with spiral CT.
AB - PURPOSE: The purpose of this work was to determine normal contrast enhancement of
the small bowel with biphasic spiral CT, using water as oral contrast agent.
METHOD: Biphasic spiral CT was performed in 50 healthy patients undergoing
evaluation as potential renal donors. All patients received 500 ml of water as
oral contrast agent and 150 ml of Omnipaque 350 administered by mechanical
injector at a rate of 3 ml/s. Dual phase CT of the abdomen was performed in each
patient. Acquisition of early phase images began 30 s after the start of the
intravenous injection, and portal phase images were obtained 60 s after
initiation of the contrast agent injection. Attenuation measurements (in
Hounsfield units) were obtained from the wall of the small bowel (duodenum,
jejunum, ileum) in both the arterial and the portal phases. RESULTS: During the
arterial phase, the mean (95% confidence interval) attenuation of the duodenum,
jejunum, and ileum was 120 (+/- 5), 119 (+/- 5), and 118 (+/- 5) HU,
respectively. During the portal phase, the average attenuation of the duodenum,
jejunum, and ileum was 111 (+/- 4), 111 (+/- 3), and 107 (+/- 3) HU,
respectively. There was no statistically significant difference between the
attenuation of the duodenum, jejunum, or ileum within either the arterial or the
portal venous phases. There was a statistically significant difference in small
bowel enhancement between the arterial and portal venous phases. CONCLUSION:
There is no important variation in small bowel attenuation during the 30 and 60 s
scanning phases. This study serves as a normal reference that may be helpful when
spiral CT is used to evaluate ischemic bowel or inflammatory small bowel
diseases.
PMID- 10667663
TI - Brenner tumor of the ovary: CT and MR findings.
AB - PURPOSE: The purpose of this study was to determine the CT and MR characteristics
of Brenner tumors, rare epithelial neoplasms of the ovary. METHOD: CT and MR
scans of eight pathologically proven Brenner tumors of the ovary (seven benign,
one malignant, and one associated with mucinous cystadenoma) were retrospectively
reviewed. The masses were analyzed for location, size, external configuration,
internal architecture, enhancement pattern, presence of calcification, and
metastatic spread. RESULTS: The patients' median age was 63 years (range 39-79
years), and the mean size of the tumors was 11.4 cm (7.5-17 cm). All tumors were
unilateral and had a well-defined margin. The mass was mostly solid in three,
mostly cystic in one, and "mixed" solid and cystic in four cases. The tumors with
cystic components (n = 5) were mostly multilocular in appearance (n = 4). All the
solid components showed mild homogeneous enhancement on postcontrast CT and MRI.
Extensive amorphous calcification within the solid component on CT was seen in
five of six cases (83%). No characteristic findings discriminating malignancy
from benign Brenner tumor could be found. CONCLUSION: Extensive amorphous
calcification in a solid mass or solid component in a multilocular cystic mass is
a characteristic finding of Brenner tumor of the ovary on CT and MRI.
PMID- 10667664
TI - Delineation of simulated vascular stenosis with Gd-DTPA-enhanced 3D gradient echo
MR angiography: an experimental study.
AB - PURPOSE: The purpose of this experimental study was to evaluate the influence of
contrast material concentration and flow velocity on pulsatile flow in Gd-DTPA
enhanced 3D gradient echo MR angiographic sequence. METHOD: In vivo flow
experiments were performed in Plexiglas phantoms with artificial stenosis (50%
stenotic ratio and 20 mm stenotic length) attached to a cardiac pump that
generated physiological pulsatile flow similar to that of the bloodstream in a
closed circuit. We used a steady-state gradient echo sequence with different TEs
(6, 3, and 1.4 ms). A TR of 15 ms was used for all parameters. The concentration
of Gd-DTPA varied from 0 to 2.0 mmol/L and flow velocities from 25 to 80 cm/s. We
measured the degree of stenosis and length of stenosis in comparison with the
actual values. RESULTS: The degree and length of stenosis on 3D gradient echo MR
angiographic images were markedly influenced by the velocity of the flow and
concentration of Gd-DTPA. The degree of stenosis was overestimated when the flow
was fast or when the concentration of Gd-DTPA was low. When the concentration of
Gd-DTPA was low, stenosis was elongated. These effects were less prominent on
short TE (1.4 ms) sequence. CONCLUSION: The stenotic lesions were markedly
overestimated on MR angiographic images obtained with Gd-DTPA-enhanced fast 3D
gradient echo sequence. Spin dephasing can be compensated for almost entirely by
a high concentration of Gd-DTPA and/or a short TE sequence.
PMID- 10667665
TI - Intravenous leiomyomatosis.
AB - We present two cases of intravenous leiomyomatosis with uterine leiomyoma or
previous hysterectomy because of uterine leiomyoma in which MRI was
characteristic. MRI showed a mass in the inferior vena cava and the heart. These
MR findings are useful in diagnosing intravenous leiomyomatosis.
PMID- 10667666
TI - Spared flow tract within the mural thrombus of an aortic aneurysm: its
pathogenesis and clinical importance.
AB - The purpose of this case report is to determine the unique pathogenesis of a
"spared flow tract" through a thick mural thrombus of an aortic aneurysm
mimicking the penetrating or dissecting tract of an impending or acute rupture of
an abdominal aortic aneurysm (AAA) and to discuss its clinical importance. Three
blood flow tracts (i.e., spared flow tracts) penetrating to aortic major branches
(inferior mesenteric arteries in two and left renal artery in one) through thick
mural thrombi of three aortic aneurysms were found on thin section spiral CT
scans. Histopathological examination revealed that the tracts were formed by
thrombi and partially covered with endothelial cells. In conclusion, spared flow
tracts may be pathways continuing to the aortic major branches through thick
mural thrombi of aortic aneurysms and are spared from thrombogenesis because of
relatively high blood flows. Their pathogenesis is definitely different from
penetrating or dissecting tracts within mural thrombi of ruptured AAAs. Spared
flow tracts should not be misinterpreted as penetrating or dissecting tracts of
impending or acute rupture.
PMID- 10667667
TI - Acute pulmonary trunk dissection in a patient with primary pulmonary
hypertension.
AB - Spiral CT imaging findings including multiplanar reconstructions of an acute
dissection of the pulmonary trunk in a 22-year-old female patient with primary
pulmonary hypertension (PPH) are presented and discussed.
PMID- 10667668
TI - Intracranial aneurysm on CTA: demonstration using a transparency volume-rendering
technique.
AB - We report an interesting transparency study using a volume-rendering technique
applied to CT angiography in a patient with a sylvian aneurysm. On a single view,
all the information required for the aneurysmal treatment could be analyzed.
Comparison with maximum intensity projection and virtual endoscopy
reconstructions was performed.
PMID- 10667669
TI - Comparison of fMRI and intraoperative direct cortical stimulation in localization
of receptive language areas.
AB - PURPOSE: The purpose of this work was to compare the cortical localization of
receptive speech using functional MRI (fMRI) and direct intraoperative electrical
stimulation. METHOD: Three strongly right-handed patients with primary neoplasms
of the left parasylvian region underwent fMRI while subjected to a passive
listening task designed to activate receptive language areas. All three subjects
then underwent awake intraoperative language mapping using direct electrical
stimulation of the cortex. RESULTS: In all three subjects, similar, but
nonidentical, cortical regions were identified as involved in receptive language
function by fMRI and direct cortical stimulation mapping. CONCLUSION: fMRI
provides excellent receptive language mapping, but its results must be
interpreted with caution due to conceptual and technical differences from direct
cortical stimulation mapping.
PMID- 10667670
TI - Taste and smell phantoms revealed by brain functional MRI (fMRI).
AB - PURPOSE: Our goal was to demonstrate the appearance of phantom tastes and smells
(phantageusia and phantosmia, respectively) by use of functional MRI (fMRI) of
the brain and to demonstrate the efficacy of drug treatment that inhibited both
the subjective presence of these phantoms and the fMRI brain activation initiated
by these phantoms. METHOD: Multislice FLASH MR or echo planar MR brain scans were
obtained in two patients with phantageusia and phantosmia in response to memory
of two tastants (salt and sweet); memory of two odors (banana and peppermint);
actual smell of amyl acetate, menthone, and pyridine; and memory of phantom
tastes and smells before and after treatment with thioridazine and haloperidol.
Activation images were derived using correlation analysis, and ratios of brain
area activated to total brain area were obtained. RESULTS: Prior to treatment,
both patients experienced persistent birhinal and global oral obnoxious tastes
and smells in the absence of any external stimulus. The fMRI response to memory
of phantoms was activation in sensory-specific brain regions for taste and smell,
respectively. fMRI activation was greater than for memory of any tastant or
odorant or for actual smell of any odor. After treatment with thioridazine or
haloperidol, which successfully inhibited each phantom in each patient, fMRI
response to phantom memory was significantly inhibited and was significantly
lower than for memory of any tastant or odorant or actual smell of any odorant.
CONCLUSION: These results demonstrate that (a) phantom taste and smell can be
revealed by fMRI brain activation, (b) brain activation in response to taste and
smell phantoms is localized in sensory-specific brain regions for taste and
smell, respectively, (c) brain activation in response to memory of each phantom
initiated the greatest degree of activation we had previously measured, and (d)
treatment with thioridazine or haloperidol inhibited both the presence of each
phantom and its associated fMRI brain activation. This is the first study in
which phantom tastes and smells have been demonstrated by an objective technique
and treatment that inhibited the phantoms was characterized by objective
inhibition of fMRI activation. These two patients represent a relatively common
group that may be classified as having primary phantageusia and phantosmia
distinct from those with phantoms or auras secondary to neurological, migrainous,
psychiatric, or other causes.
PMID- 10667671
TI - Cerebral perfusion MRI with arterial spin labeling technique at 0.5 Tesla.
AB - PURPOSE: Our aim was to evaluate the feasibility of cerebral perfusion MRI using
an arterial spin labeling technique at 0.5 T. METHOD: We performed perfusion
imaging with a flow-sensitive alternating inversion recovery (FAIR) sequence in a
total of 37 patients with cerebral infarction. RESULTS: FAIR perfusion images
demonstrated areas of pathological perfusion corresponding (13 patients) or not
corresponding (15 patients) to the infarcted area on MR images. Among 19 patients
in whom comparison between FAIR perfusion imaging and regional cerebral blood
flow single photon emission CT was available, the two studies correlated well in
15 patients. CONCLUSION: Our results indicate that the FAIR technique allows
reliable cerebral perfusion imaging at 0.5 T.
PMID- 10667672
TI - Analyzing functional brain images in a probabilistic atlas: a validation of
subvolume thresholding.
AB - PURPOSE: The development of structural probabilistic brain atlases provides the
framework for new analytic methods capable of combining anatomic information with
the statistical mapping of functional brain data. Approaches for statistical
mapping that utilize information about the anatomic variability and registration
errors of a population within the Talairach atlas space will enhance our
understanding of the interplay between human brain structure and function.
METHOD: We present a subvolume thresholding (SVT) method for analyzing positron
emission tomography (PET) and single photon emission CT data and determining
separately the statistical significance of the effects of motor stimulation on
brain perfusion. Incorporation of a priori anatomical information into the
functional SVT model is achieved by selecting a proper anatomically partitioned
probabilistic atlas for the data. We use a general Gaussian random field model to
account for the intrinsic differences in intensity distribution across brain
regions related to the physiology of brain activation, attenuation effects, dead
time, and other corrections in PET imaging and data reconstruction. RESULTS:
H2(15)O PET scans were acquired from six normal subjects under two different
activation paradigms: left-hand and right-hand finger-tracking task with visual
stimulus. Regional region-of-interest and local (voxel) group differences between
the left and right motor tasks were obtained using nonparametric stochastic
variance estimates. As expected from our simple finger movement paradigm,
significant activation (z = 6.7) was identified in the left motor cortex for the
right movement task and significant activation (z = 6.3) for the left movement
task in the right motor cortex. CONCLUSION: We propose, test, and validate a
probabilistic SVT method for mapping statistical variability between groups in
subtraction paradigm studies of functional brain data. This method incorporates
knowledge of, and controls for, anatomic variability contained in modern human
brain probabilistic atlases in functional statistical mapping of the brain.
PMID- 10667673
TI - The identification of cerebral volume changes in treated growth hormone-deficient
adults using serial 3D MR image processing.
AB - PURPOSE: A pilot study to detect volume changes of cerebral structures in growth
hormone (GH)-deficient adults treated with GH using serial 3D MR image processing
and to assess need for segmentation prior to registration was conducted. METHOD:
Volume MR scans of the brain were obtained in five patients and six control
subjects. Patients were scanned before and after 3 and 6 months of therapy.
Control subjects were scanned at the same intervals. A phantom was used to
quantify scaling errors. Second and third volumes were aligned with the baseline
by maximizing normalized mutual information and transformed using sinc
interpolation. Registration was performed with and without brain segmentation and
correction of scaling errors. Each registered, transformed image had the original
subtracted, generating a difference image. Structural change and effects of
segmentation and scaling error correction were assessed on original and
difference images. The radiologists' ability to detect volume change was also
assessed. RESULTS: Compared with control subjects, GH-treated subjects had an
increase in cerebral volume and reduction in ventricular volume (p = 0.91 x 10(
3)). Scale correction and segmentation made no difference (p = 1 and p = 0.873).
Structural changes were identified in the difference images but not in the
original (p = 0.136). The radiologists detected changes >200 microm. CONCLUSION:
GH treatment in deficient patients results in cerebral volume changes detectable
by registration and subtraction of serial MR studies but not by standard
assessment of images. This registration method did not require prior
segmentation.
PMID- 10667674
TI - Evaluation of 201T1 SPECT for predicting early treatment response in patients
with squamous cell carcinoma of the extracranial head and neck treated with
nonsurgical organ preservation therapy: initial results.
AB - PURPOSE: The purpose of this work was to prospectively determine the ability of
210TI single photon emission CT (SPECT) to monitor treatment response in patients
with head and neck squamous cell carcinoma (HNSCCA) treated with nonsurgical
organ preservation. METHOD: Nine patients with HNSCCA underwent 201T1 SPECT
before and 6 weeks after completion of nonsurgical organ preservation therapy.
All cases were evaluated for uptake at the primary site before and after
treatment. All tumors had abnormal radiotracer uptake on the pretreatment study.
The posttreatment thallium studies were evaluated for uptake and correlated with
local control at the primary site in all cases. RESULTS: All patients had
abnormal thallium uptake on pretreatment studies. Of the nine patients, four
cases were locally controlled by nonsurgical organ preservation therapy. All of
these patients had no evidence of thallium uptake on posttreatment studies. Five
cases failed treatment at the primary site. All five patients demonstrated
abnormal radiotracer uptake at the primary site. CONCLUSION: Our initial results
suggest that 201T1 SPECT may be an accurate technique for monitoring HNSCCA
treated with nonsurgical organ preservation therapy.
PMID- 10667675
TI - Augmentation procedures of the jaw in patients with inadequate bone for dental
implants: radiographic appearance.
AB - Dental implants, metallic posts surgically imbedded in the jaw to support dental
prostheses, have provided an attractive alternative to standard removable
dentures. Some patients, however, have insufficient bone to accommodate these
implants. In this setting, a number of surgical procedures are available to
augment the bone in the jaw. It is important for radiologists to be familiar with
these procedures because the altered anatomy can be a source of confusion to the
unwary. The objective, therefore, was to describe these procedures and their
radiographic appearances.
PMID- 10667676
TI - MR observations of postraumatic osteolysis of the distal clavicle after traumatic
separation of the acromioclavicular joint.
AB - PURPOSE: The purpose of this work was to characterize the MR features of post
traumatic osteolysis of the distal clavicle in patients who have sustained a
previous separation of the ipsilateral acromioclavicular (AC) joint. METHOD: We
studied eight male patients (mean age 25 years) with intractable pain in the AC
joint after sustaining a traumatic joint separation. With use of the Rockwood
classification, the separations were classified as Type 1 in one patient, Type 2
in two patients, and Type 3 in five patients. The MR studies were evaluated for
periarticular soft tissue swelling, cortical irregularity defined as thinning or
absence of portions of the cortex in the acromial and clavicular articular
surfaces, hypertrophic osseous changes, periostitis, bone marrow edema,
periarticular cyst-like changes, and joint space widening exceeding 6 mm.
Radiographs were evaluated independently of the MR studies. Osteolysis of the
distal clavicle was confirmed pathologically in seven patients and with surgery
in one patient. RESULTS: The incidence of osteolysis in patients who have had a
previous AC joint separation was estimated to be approximately 6%. Observations
on MRI included soft tissue swelling, bone marrow edema in the distal clavicle,
and cortical irregularity associated with periarticular cyst-like erosions in
eight patients, joint space widening in six patients, clavicular periostitis in
three patients, and marrow edema in the cromion in five patients. Only one
patient had osteophyte formation. Radiographic observations of periarticular soft
tissue swelling, osteopenia of the distal clavicle, articular erosions, and joint
space widening allowed diagnosis in only four patients prospectively. CONCLUSION:
The MR features of posttraumatic osteolysis are characteristic of this process.
We advocate the use of MRI in patients with chronic AC joint pain who have had a
prior AC joint dislocation, particularly if follow-up radiographs are
nonspecific, equivocal, or do not indicate the presence of secondary
osteoarthritis.
PMID- 10667678
TI - Metaphyseal undertubulation in gaucher disease: resolution at MRI in a patient
undergoing enzyme replacement therapy.
AB - Gaucher disease is a sphingolipid storage disorder that results in the
accumulation of Gaucher cells within the reticuloendothelial system. The life
span can be near normal in the most common form. Our case illustrates the
resolution of the skeletal findings in Gaucher disease following enzyme
replacement therapy. We also report the correlation of these findings with
clinical improvement.
PMID- 10667677
TI - CT of metal implants: reduction of artifacts using an extended CT scale
technique.
AB - PURPOSE: The purpose of this work was to use an extended CT scale technique
(ECTS) to reduce artifacts due to metal implants and to optimize CT imaging
parameters for metal implants using an experimental model. METHOD: Osteotomies
were performed in 20 porcine femur specimens. One hundred cobalt-base screws and
24 steel plates were used for osteosynthesis in these specimens. Artificial
lesions were produced in 50 screws, such as osteolysis near the screws (mimicking
lysis due to infection, tumor, or loosening), displacement of the screws, as well
as fractures of the screws. All specimens were examined using eight different CT
protocols: four conventional (CCT) and four spiral (SCT) CT protocols with
different milliampere-second values (130 and 480 mAs for CCT, 130 and 300 mAs for
SCT), kilovolt potentials (120 and 140 kVp), and slice thicknesses (2 and 5 mm).
The images were analyzed by three observers using a standard window (maximum
window width 4,000 HU) and ECTS (maximum window width 40,000 HU). Receiver
operating characteristic analysis was performed, and image quality was assessed
according to a five level scale. RESULTS: Metal artifacts were significantly
reduced using ECTS (p < 0.05). The highest diagnostic performance was obtained
using ECTS with the thinnest slice thickness. Metal artifacts were more
pronounced using SCT. In this experimental model, exposure dose and kilovolt
potential had no significant impact on diagnostic performance (p > 0.05).
CONCLUSION: ECTS improved imaging of metal implants. In this study, no
significant effects of exposure dose and kilovolt potential were noted. Metal
artifacts were more prominent using SCT than using CCT.
PMID- 10667679
TI - MRI in sacral echinococcosis.
PMID- 10667680
TI - Aunt Minnies's Corner. A case with radiologic findings so specific that no
realistic differential diagnosis exists.
PMID- 10667681
TI - The Stockholm Consensus Conference on quality specifications in laboratory
medicine, 25-26 April 1999.
PMID- 10667682
TI - Introduction: strategies to set global quality specifications in laboratory
medicine.
PMID- 10667683
TI - Determination and application of desirable analytical performance goals: the
ISO/TC 212 approach.
AB - Desirable analytical performance goals are needed to place clinical laboratories'
quality management plan on a rational basis. While the most important basis of
desirable analytical performance goals is medical needs, a well-established
quality management plan must take into account economic and regulatory needs.
There are many approaches that have been proposed for determining desirable
analytical performance goals. The ISO/TC 212 approach for rationalizing the
various approaches for determining desirable analytical performance goals, which
is based on the ability to meet medical needs, is presented.
PMID- 10667684
TI - The need for a system of quality standards for modern quality management.
AB - The management of analytical quality depends on the careful evaluation of the
imprecision (uncertainty) and inaccuracy (trueness) of laboratory methods and the
application of statistical quality control procedures to detect medically
important analytical errors that may occur during routine analysis. A system of
quality standards is recommended to incorporate different types of requirements,
such as clinical outcome criteria, analytical outcome criteria, and analytical
performance criteria. For practical applications, all need to be translated into
operating specifications for the imprecision, inaccuracy, control rules, and
number of control measurements that are necessary to assure analytical quality
during routine production of test results.
PMID- 10667685
TI - General strategies to set quality specifications for reliability performance
characteristics.
AB - Many strategies have been promulgated for the setting of quality specifications
in laboratory medicine. Based on the analysis of the effect of error on clinical
decision making, general quality specifications for precision, bias, the
allowable difference between two analytical methods, drugs, fixed limits for use
in external quality assessment and reference methods seem best derived from
components of biological variation.
PMID- 10667686
TI - Current databases on biological variation: pros, cons and progress.
AB - A database with reliable information to derive definitive analytical quality
specifications for a large number of clinical laboratory tests was prepared in
this work. This was achieved by comparing and correlating descriptive data and
relevant observations with the biological variation information, an approach that
had not been used in the previous efforts of this type. The material compiled in
the database was obtained from published articles referenced in BIOS, CURRENT
CONTENTS, EMBASE and MEDLINE using "biological variation & laboratory medicine"
as key words, as well as books and doctoral theses provided by their authors. The
database covers 316 quantities and reviews 191 articles, fewer than 10 of which
had to be rejected. The within- and between-subject coefficients of variation and
the subsequent desirable quality specifications for precision, bias and total
error for all the quantities accepted are presented. Sex-related stratification
of results was justified for only four quantities and, in these cases, quality
specifications were derived from the group with lower within-subject variation.
For certain quantities, biological variation in pathological states was higher
than in the healthy state. In these cases, quality specifications were derived
only from the healthy population (most stringent). Several quantities
(particularly hormones) have been treated in very few articles and the results
found are highly discrepant. Therefore, professionals in laboratory medicine
should be strongly encouraged to study the quantities for which results are
discrepant, the 90 quantities described in only one paper and the numerous
quantities that have not been the subject of study.
PMID- 10667687
TI - Series analyses and quality specifications required for monitoring over time.
AB - General specifications of analytical goals for biochemical monitoring have been
proposed based on biological within-subject variation. As a complement to this
strategy for general global quality requirements there is also a need for other
methods and approaches to set more optimal requirements in specific monitoring
situations, i.e. application of systems and sensitivity analysis using (i) rules
for propagation of errors (uncertainty) in simple algebraic/statistical
transformations of laboratory results; (ii) biochemical/pathophysiological
simulation models; and (iii) formalized descriptions of clinical classification
and decision support processes. The possible gain in medical outcome by improving
analytical and preanalytical quality should then be related to the often more
important aspects of selection and combination of "tests", period and frequency
of sampling/measurement, and the use of correct conceptual and computational
models for transformation of data.
PMID- 10667688
TI - Analytic bias specifications based on the analysis of effects on performance of
medical guidelines.
AB - Laboratory tests are key indicators for certain practice guidelines, and analytic
bias can significantly alter the performance of these guidelines. Three clinical
paradigms are described: serum cholesterol testing for risk assessment of cardiac
disease, serum thyroid-stimulating hormone (TSH) measurement for the detection of
hypothyroidism, and serum prostate-specific antigen (PSA) testing for prostate
cancer risk assessment. Maximum tolerance limits for analytic bias are calculated
by assessing the subgroup population fluctuations in the number of patients
exceeding the guideline threshold values and limiting the analytic bias to one
half of these fluctuations. Our calculated maximum bias limits are +/-1% for
cholesterol and +/-6% for TSH and PSA. Our recommended +/-1% bias limit for
cholesterol allows for a -6.5% to + 5.8% change in the number of patients
designated as at risk for cardiac disease, whereas the +/-3% National Cholesterol
Education Program limits permit a -18.4% to +16.7% variation. Similarly, our +/
6% bias limits for TSH allow a -17.7% to +26.6% change in patients flagged for
hypothyroidism, whereas the +/-10% bias values found with many commercial
reagents permit a -28.2% to +49.2% variation in patient classification. Our +/-6%
PSA bias limits correspond to changes from -14.2% to +11.4% in the number of men
classified as at risk for prostate cancer. The +/-10% bias ranges for PSA
correspond to -19.9% to +20.4% variation in patient classification. The larger
tolerance limits of the CLIA-88 standards for proficiency testing would cause
even wider variations in patient classifications.
PMID- 10667689
TI - Quality specifications based on the uncertainty of measurement.
AB - The result of a measurement needs to be accompanied by information on the error
or uncertainty of the measurement. Either of two very closely related concepts is
thus required to indicate the usefulness and relevance of a result for its
purpose: decision making. This presentation will outline the difference between
the concept of error and that of uncertainty and deal with procedures to estimate
the latter. The use of a spreadsheet program will illustrate how the combined
uncertainty is estimated in a relatively complex situation with a bearing on
laboratory medicine.
PMID- 10667690
TI - Quality specifications based on analysis of effects of performance on clinical
decision-making.
AB - The graphical model for evaluation of analytical requirements for bimodal
distributions, based on probit transformation and calculation of false-positive
and false-negative results for assumed random and systematic analytical errors,
is presented in theory. It is concluded that the bimodal model is an excellent
tool for evaluation of the effect of analytical quality and, therefore, useful
for estimation of analytical quality specifications for quantities used in
specific clinical strategies and situations as well as based on analysis of
clinical outcome.
PMID- 10667691
TI - Quality specifications for ordinal scale measurements with multiproperty
(multiple) urine test strips.
AB - Analytical quality specifications for ordinal scale measurements have not been
presented so far. Criteria are suggested for multiproperty (multiple) urine test
strips based on upper limits of healthy reference intervals, analytical
performance and statistical tests applicable to ordinal scales. Trueness
(accuracy) can be evaluated against an acceptable comparison method by applying
sensitivity and specificity concepts, and defining a grey zone with a lower
detection limit and an upper confirmation limit. Concordance (agreement) of two
or more ordinal scale categories should be evaluated by subtracting random
agreement, using Kappa statistics. Repeatability (precision) can be calculated
for categorized results using binomial statistics.
PMID- 10667692
TI - Setting process control limits for enzyme tests in serum.
AB - With the advent of much more precise laboratory equipment, the use of performance
based standard deviations for enzymes, e.g. those based on the precision of the
laboratory during a period of "satisfactory performance", is not appropriate; it
leads to overly rigid precision limits and unnecessary repeat assays, and is
wasteful of resources. Testing for the commonly used serum enzymes does not
require tight precision given how enzyme data are viewed by most clinicians.
Other ways to set process control limits all have some arbitrary content;
however, this need not prevent their use. Laboratorians must choose the approach
that is appropriate for their laboratory and medical staff to meet medically
perceived needs.
PMID- 10667693
TI - Quality specifications derived from objective analyses based upon clinical needs.
AB - The well-informed physician should be the best to judge the analytical quality
needed for a specific clinical action. By presenting the physicians with well
designed case histories, it is possible to extract the clinical knowledge
pertinent to analytical quality. The clinicians are asked which changes in the
concentration of an analyte will cause them to change actions concerning the
patient. It must be possible to detect these changes with a certain probability
and this presupposes a certain analytical quality which can then be calculated.
It is important that a strict methodology both for constructing case histories
and for calculation of the required analytical quality is used.
PMID- 10667694
TI - Quality specifications for reference methods.
AB - Reference methods are a key element to the objective of traceability in
laboratory medicine. However, to serve this purpose adequately, minimum
analytical quality specifications are required. Here, possible strategies for
deriving such specifications are presented, being based on concepts developed
before by a European Working Group. Distinction is made between "genuine
requirements" for reference methods (direct calibration with primary reference
materials; absence of sample-related effects) and "performance specifications"
(limits for random, systematic and total error, the latter in association with
the number of measurements). While the former requirements are considered as
conditio sine-qua-non, the latter specifications should be variable, which means
that they should be tailored to the specific application of the methods. In
general, it is advocated to derive performance specifications for reference
methods from desirable specifications of routine methods (analyte-related),
although other models should not be ruled out beforehand. Further, it is
recommended that reference laboratories make special efforts to demonstrate and
maintain a uniform level of quality of reference methods.
PMID- 10667695
TI - Development and use of analytical quality specifications in the in vitro
diagnostics medical device industry.
AB - Manufacturers of in vitro diagnostic (IVD) medical devices have become integral
partners with their customers in determining the quality of laboratory results.
Design controls imposed by ISO 9001 quality system standards and various
regulations require manufacturers to implement a formal design process, which
begins and ends with customer requirements. For IVD systems, this means that
manufacturers must establish analytical quality specifications as part of their
design input. This provides greater assurance that commercial products will
satisfy customer requirements. In the case of quantitative IVD measurement
systems, analytical quality specifications include total allowable uncertainty
(bias, imprecision, non-specificity). The primary source of customer requirements
is the laboratory-customer, who should have established analytical quality
specifications based on the needs of its physician-clients. The total allowable
uncertainty budget is allocated in the design process to the individual
components of the system, such as reagents, instrumentation, calibrators and
accessories, and to other factors such as operator, specimen and environmental
interactions. Their performance must collectively meet the total allowable
uncertainty specification when they are finally integrated into a measurement
system. The design control model requires objective evidence that design
specifications have been met (verification) and, finally, that the system will
satisfy the needs of its intended users (validation). Compliance with the quality
system standards is monitored through independent audits, government inspections
and post-market surveillance.
PMID- 10667696
TI - Preanalytical factors and their influence on analytical quality specifications.
AB - Whereas analytical standards are described by established quality control
criteria, no such standards exist for defining the quality of the preanalytical
phase. A working group of the German Society for Clinical Chemistry and
Laboratory Medicine has defined recommendations to describe the quality criteria
for materials and processes used in the diagnostic process between patients and
the analytical step. Thus, the quality of the sample may be defined regarding its
adequacy and amount, as well as anticoagulants and stabilizers used. Timing of
sampling, transport and storage involve criteria on sample stability, proper
transport and preanalytical treatment. Moreover, sample identification, storage,
and handling of interference and influence factors can be documented in quality
manuals for the preanalytical phase. These possible variables have been discussed
in five European expert meetings and recommendations published in national
journals and presented in book form.
PMID- 10667697
TI - Postanalytical factors and their influence on analytical quality specifications.
AB - Quality thinking in medical laboratories is placed within the framework of the
European Foundation for Quality Management Model which suggests the use of
medical outcome indicators such as those developed by the Joint Commission on
Accreditation of Healthcare Organizations. From here concepts were illustrated to
improve the quality of the medical laboratory towards the data produced but
moreover towards the information given, the knowledge acquired and the decision
taken. Postanalytical factors were used to define analytical quality
specifications.
PMID- 10667698
TI - Analytical quality, performance indices and laboratory service.
AB - Faulty data lead to suboptimal diagnostics and decision making unless the flaw is
known and amenable to correction. However, pure noise (added analytical variance)
has only minor effects on clinically appropriate indices of diagnostic
performance. This fact is illustrated by an idealized screening programme, using
the preventive benefit-to-cost ratio as the index of performance. Further, this
article illustrates that the effect of an unnoticed source of noise is roughly
just twice the effect that the same noise will have when its magnitude is known
and clinical decision limits are adjusted accordingly. Owing to the small size of
these effects, however, it may be profitable to spend resources on other aspects
of good laboratory service, such as timeliness, documentation and interpretative
support.
PMID- 10667699
TI - Quality specifications of clinical laboratory procedures: developing country
needs.
AB - In developing countries laboratory measurements are made in specimens of
populations that are usually of different genetic origin and live in a different
environment, under working conditions that differ from those of industrialized
countries. The setting of quality specifications of laboratory measurements must
take into account such differences to improve the quality of laboratory services
in these countries. Industry and professional organizations should be aware of
the differences, otherwise their recommendations may counteract efforts to
improve laboratory services in developing countries.
PMID- 10667700
TI - Effect of legislation (CLIA'88) on setting quality specifications for US
laboratories.
AB - The Clinical Laboratory Improvement Amendments of 1988 (CLIA'88) mandated, in
response to concern over the perceived quality of clinical laboratory testing,
universal regulation for all testing sites in the USA, including previously
unregulated sites in physician offices. The intent of CLIA'88 is to ensure
quality of testing through a combination of total quality management and mandated
minimum quality practices. CLIA also defines, intentionally or unintentionally,
through its proficiency testing requirements, intralaboratory performance
standards. Meeting these requirements has been a prime motivator in improving
laboratory performance. Seven years after the implementation of CLIA'88, the
percentage of laboratories passing proficiency testing has increased and most
laboratories have implemented quality practices.
PMID- 10667701
TI - Effect of current and forthcoming European legislation and standardization on the
setting of quality specifications by laboratories.
AB - A network of national and international guidelines and directives developed in
the last few decades by various bodies will lead to a new concept of total
quality for medical laboratory services comprising legislative regulations on
national and international levels, standardizations backed up by legislation and
recommendations of professional societies. One example is the IVD Directive of
the European Community. It will not only stimulate accreditation in the field of
laboratory medicine, but also necessitate numerous standardization activities
which are presently co-ordinated by the European Committee for Standardization
(CEN). Another standardization example is the development of quality management
systems, mainly by ISO. The ISO 9000 series has become the most successful family
of standards world-wide. Meanwhile, specific standards for the needs of
laboratories (ISO 17025), and in particular of medical laboratories (ISO 15189),
are being worked out. A new trend to develop quality management systems towards
total quality management systems can be observed including additional aspects
such as economic and quality interests of society, customers and owners of
laboratories. The goal of all activities is to create a network of confidence
which provides some guarantee to the clients, i.e. the physicians and their
patients, that they will receive a high-quality medical laboratory service.
PMID- 10667702
TI - Effect of accreditation schemes on the setting of quality specifications by
laboratories.
AB - In the future, there will be a universal standard for quality management in
medical laboratories: ISO 15189. This standard follows the basic principles of
ISO 17025, the general standard for test laboratories, but also adds several
specific aspects. A comparison between these standards is given. The language of
ISO 15189 is designed to be understood by medical laboratory professionals. As
this standard is applicable to all medical laboratory fields, requirements are
given in general terms requiring the laboratory to implement them correctly.
Because it is essential that information provided by laboratory results is useful
for healthcare, the requirements covered by ISO 15189 are compared with those
needed for providing good medical laboratory services. The capabilities of the
personnel at the laboratory clinic interface are the most difficult to assess and
evaluate in an adequate quality management system.
PMID- 10667703
TI - Setting quality specifications for the future with newer approaches to defining
uncertainty in laboratory medicine.
AB - When describing the performance of procedures and the reliability of their
results, ISO terminology should be used. Results should be universally comparable
and this requires metrological traceability. The concomitant uncertainty
(inversely) indicating reliability should be obtained in a universal and
transparent fashion, and should be combinable. Therefore, the approach of the
"Guide to the expression of uncertainty in measurement", leading to a result
without known bias and a combined standard uncertainty, has advantages over the
allowable total error concept, incorporating procedural bias.
PMID- 10667704
TI - The beginning of the artificial eye program.
PMID- 10667705
TI - Artificial vision for the blind by connecting a television camera to the visual
cortex.
AB - Blindness is more feared by the public than any ailment with the exception of
cancer and AIDS. We report the development of the first visual prosthesis
providing useful "artificial vision" to a blind volunteer by connecting a digital
video camera, computer, and associated electronics to the visual cortex of his
brain. This device has been the objective of a development effort begun by our
group in 1968 and represents realization of the prediction of an artificial
vision system made by Benjamin Franklin in his report on the "kite and key"
experiment, with which he discovered electricity in 1751.
PMID- 10667706
TI - Peter Robert Uldall 1935-1995: a personal tribute.
PMID- 10667708
TI - FDA reform legislation and its effect on clinical trials.
PMID- 10667707
TI - Home hemodialysis: a crazy idea in 1963: a memoir.
AB - In 1963, one of the abstracts we submitted for the Ninth ASAIO Congress entitled
"Hemodialysis at Home: Utilizing Domestic Electric Washing Machine" by Y. Nose
and J. Mikami was rejected. At that time, leading ASAIO nephrologists, including
W. J. Kolff, B. H. Scribner, and J. P. Merrill, did not favor patients dialyzing
at home in spite of it being the only means of keeping renal failure patients
alive. Also at that time, many patients died because of the unavailability of
hemodialysis in hospitals. However, in 1965 both Dr. Scribner's group in Seattle
and Dr. Merrill's group in Boston initiated a home hemodialysis program. This
program was further expanded in many centers, including Dr. Kolff's at Cleveland
Clinic. Later, home hemodialysis was proven a safe, effective, yet inexpensive
method of treating chronic renal insufficiency patients.
PMID- 10667709
TI - Conduct of device clinical trials: the need for collaboration in response to a
changing health care environment.
AB - Prior to initiating a clinical trial, many issues need to be discussed to insure
an adequate understanding of the investigators' and sponsors' limitations,
capabilities, and expectations. Many of these issues are addressed in contracts
and agreements, the formats for which have evolved over many years. In these
documents, issues such as publication rights, access to results, confidentiality,
conditions for termination, compensation, and indemnification are covered.
However, other essential, although noncontractual issues that reflect upon trends
in and the climate of the health care system, need to be discussed. Issues such
as the development of collaborative cost-effectiveness studies, public relations
plans, content of a cost-benefit analysis, results of other trials, reimbursement
strategies, and the development of resources that contribute to the ease, safety,
and efficacy of device use. With the increasing expense, oversight, and
administrative burden for the conduct and participation in clinical trials, there
is a correspondingly greater need for sponsor and investigator communication,
collaboration, and risk and cost sharing to ensure the successful outcome of
clinical trials today.
PMID- 10667710
TI - Clinical trial: a clinician's perspective.
AB - As a result of my participation in several clinical trials at The University of
Iowa, I have now redrawn what I perceive to be the algorithm for conduct of a
clinical trial. Of note, I have excluded the development of the new device, in
vitro device testing, in vivo animal experimentation, clinical protocol
development, granting of an Investigational Device Exemption, and the process by
which clinical sites are selected. Following my algorithm I have made no mention
of the commercialization of an experimental device, including the Pre-Market
Approval process and FDA panel meetings. In summary, I believe there are a
variety of reasons why a principal investigator would choose to participate in a
clinical trial. With tongue in cheek, I would offer fame and fortune as two
possible motivating factors. Obviously, both are double-edged swords. Should a
trial not turn out as hoped, celebrity can instantly turn to notoriety. With
respect to fortune, administrative and clinical activity performed by the
principal investigator on behalf of the clinical trial does not generate income,
and, in fact, can place a considerable financial drain on the investigator's
department. I believe that investigators are strongly driven by intellectual
curiosity, but it is important to maintain perspective when participating in a
clinical trial. The real reason we seek clinical trial site designation is to
allow us to offer new, innovative therapeutic modalities to our patients. By so
doing, it is imperative that we conduct the clinical trial in as thoughtful and
as safe a manner as possible, with our patients' well being always foremost in
our minds.
PMID- 10667711
TI - The conduct of clinical trials: a Food and Drug Agency perspective.
AB - The conduct of a clinical trial required by FDA regulations should be executed in
conformity with a protocol developed as a cooperative endeavor involving the
Agency, the sponsor requiring device approval for marketing, and the
investigators. This is the process most likely to assure a scientifically
satisfactory study design that will address the primary concerns of all the
parties. More importantly, timely access to safe and effective technologic
advances will be made available to the health provider community based on the
best scientific evidence.
PMID- 10667712
TI - Clinical trials: a sponsor's perspective: overview.
PMID- 10667713
TI - Bacterial components inhibit fibroblast proliferation in vitro.
AB - Perigraft fluid from Staphylococcus epidermidis infected grafts in a mouse model
significantly inhibits fibroblast proliferation (60-98% at 7 and 28 days),
compared with perigraft fluid from sterile grafts. The fibroblast inhibitor was
trypsin-heat resistant and dependent primarily upon the bacteria, not the host
proinflammatory mediators or the vascular graft biomaterial. We tested the
inhibitory properties of S. epidermidis strains RP62A (slime producer) and RP62NA
(nonslime producer) and Staphylococcus aureus strain 502a, using an in vitro
tritiated thymidine murine fibroblast (ATCC CCL-12) proliferation assay. Whole
killed bacteria, disrupted bacteria (live and killed), bacterial supernatants,
and purified cell wall products (peptidoglycan, teichoic acid, and lipoteichoic
acid from disrupted bacteria) were studied. Significant fibroblast inhibition
occurred for all three bacterial strains with disrupted bacteria (live or killed)
and cell free bacteria derived supernatants. The fibroblast inhibitor from
disrupted slime producing S. epidermidis was trypsin-heat resistant. The
fibroblast inhibitor from disrupted S. aureus and supernatants for all three
bacterial strains at 1 x 10(7) were trypsin-heat sensitive. Fibroblast inhibition
was not dependent upon bacterial viability and not mediated by bacterial cell
wall products. In conclusion, components of slime and nonslime producing S.
epidermidis and S. aureus inhibit fibroblast proliferation.
PMID- 10667714
TI - A siliconized hollow fiber membrane oxygenator.
AB - Most membrane oxygenators are built with microporous fibers known for plasma
leakage in long-term use such as extracorporeal life support or extracorporeal
membrane oxygenation. The current study was designed to evaluate the Quadrox
oxygenator in which the fibers have been coated with silicone (Jostra). Six
calves (mean weight, 62 +/- 4 kg) were connected to cardiopulmonary bypass (CPB)
by jugular venous and carotid arterial cannulation, with a mean flow rate of 3
L/min for 6 hours. They were randomly assigned to a standard Quadrox oxygenator
(standard group, n = 3) or a siliconized Quadrox oxygenator (silicone group, n =
3). After 7 days, the animals were sacrificed. A standard battery of blood
samples was taken before bypass, after mixing for 10 minutes, and after 1, 2, 5,
and 6 hours of perfusion. Analysis of variance was used for repeated
measurements. Total oxygen transfer and carbon dioxide transfer did not differ
between groups (p = 0.5 for comparison). Blood trauma, evaluated by plasma
hemoglobin (Hb), did not detect any significant hemolysis in either group.
Thrombocyte and white blood cell count profiles in both groups were parallel and
without significant differences (p = 0.1 and 0.6, respectively). At the end of
testing no clot deposition was found in the oxygenator. At postmortem, there were
no signs of peripheral emboli. The results of this study suggest that this
silicone coating of hollow fibers allows for good gas transfer, while preserving
all the mechanical advantages of a conventional hollow fiber oxygenator.
PMID- 10667715
TI - Hemodynamic effects of attachment modes and device design of a thoracic
artificial lung.
AB - A thoracic artificial lung (TAL) was designed to treat respiratory insufficiency,
acting as a temporary assist device in acute cases or as a bridge to transplant
in chronic cases. We developed a computational model of the pulmonary circulatory
system with the TAL inserted. The model was employed to investigate the effects
of parameter values and flow distributions on power generated by the right
ventricle, pulsatility in the pulmonary system, inlet flow to the left atrium,
and input impedance. The ratio of right ventricle (RV) power to cardiac output
ranges between 0.05 and 0.10 W/(L/min) from implantation configurations of low
impedance to those of high impedance, with a control value of 0.04 W/(L/min).
Addition of an inlet compliance to the TAL reduces right heart power (RHP) and
impedance. A compliant TAL housing reduces flow pulsatility in the fiber bundle,
thus affecting oxygen transfer rates. An elevated bundle resistance reduces flow
pulsatility in the bundle, but at the expense of increased right heart power. The
hybrid implantation mode, with inflow to the TAL from the proximal pulmonary
artery (PA), outflow branches to the distal PA and the left atrium (LA), a band
around the PA between the two anastomoses, and a band around the outlet graft to
the LA, is the best compromise between hemodynamic performance and preservation
of some portion of the nonpulmonary functions of the natural lungs.
PMID- 10667716
TI - Morphologic studies of hepatocytes entrapped in hollow fibers of a bioartificial
liver.
AB - A bioartificial liver cartridge was prepared by inoculating porcine hepatocytes
into the inner space of hollow fibers of a hemodialyzer. The hepatocytes formed
rod shaped cell aggregates during in vitro perfusion culture within 1 day.
Morphologic examination was carried out on the aggregates by optical and electron
microscopy. Each hepatocyte was in direct contact with adjacent cells and a bile
canaliculus-like structure was occasionally seen between hepatocytes. High
magnification observation showed that the canaliculus was separated from the
remainder of the intercellular space by a tight junction. These facts suggest
that the hepatocytes formed functionally associated cell aggregates with a
compact morphology not unlike hepatocyte spheroids. These structures were well
maintained for 7 days in culture, and then the amorphous area in the aggregates
and the nonviable cell number increased with lengthening culture period. The
bioartificial liver maintained the ability to metabolize lidocaine, ammonia, and
galactose for 7 days and then deteriorated with time.
PMID- 10667717
TI - Effects of recombinant human hepatocyte growth factor on the proliferation and
function of porcine hepatocytes.
AB - A porcine hepatocyte based bioartificial liver (BAL) is still insufficient to
replace liver transplantation. In this experiment, to strengthen the performance
of a BAL, the effect of human recombinant hepatocyte growth factor (rhHGF) on the
proliferation and function of xenogeneic porcine hepatocytes was studied.
Isolated porcine hepatocytes were seeded at various densities (5 x 10(3) to 8 x
10(4) cells/well) on a collagen coated 96 well plate in Dulbecco's modified
Eagle's medium (DMEM) with 10% FCS. After 4 hours, the medium was changed to DMEM
with added insulin and dexamethasone. Subsequently, rhHGF was added at various
concentrations (0, 0.625, 1.25, 2.5, 5, 10, 20, 40 ng/ml) and cultured for an
additional 24, 48, and 72 hours, respectively. The proliferation of porcine
hepatocytes in response to rhHGF reached a plateau at 2.5 ng/ml at 24 hours and
subsequently decreased. The levels of porcine albumin vs protein present in the
supernatant increased when cultured at high cell density. In conclusion, rhHGF
was found to stimulate proliferation of porcine hepatocytes at low cell density
and low concentration. rhHGF can also increase albumin synthesis at higher cell
density, thus indicating its potential use in a more satisfactory porcine
hepatocyte based BAL.
PMID- 10667718
TI - I: Negative effect of cold ischemia on initial renal function.
AB - Correlation between post-transplant function and exposure to cold ischemia (CI)
during preservation has been reported. We attempted to identify the effect of CI
on renal function using exsanguinous metabolic support (EMS) technology, to
eliminate effects of reperfusion complications. Small bovine kidneys were used to
evaluate 4 vs. 24 hours of CI, after warm ischemic (WI) exposure of <15, 30 or 60
minutes. After CI, kidneys were warm perfused (30 degrees C to 32 degrees C) ex
vivo using EMS technology. Restored renal metabolism and function were quantified
by oxygen consumption, urine production, glomerular filtration rate (GFR), and
hemodynamic characteristics. The results demonstrate a CI-associated lag phase in
the restoration of metabolism, in which the longer cold-preserved kidneys exhibit
a lower initial rate of oxygen consumption. However, after 3 hours of EMS
perfusion there was no significant difference in the O2 consumed, urine flow,
GFR, perfusion flow, or pressure between the kidneys stored for 4 or 24 hours. An
initial reduction in metabolism after longer CI may influence the severity of
actual reperfusion injury during transplantation. Therefore, these results
provide preliminary evidence suggesting that an acellular warm temperature
reperfusion ex vivo may enhance restoration of cellular metabolism and minimize
damage from the cold seen upon actual reperfusion.
PMID- 10667719
TI - II: Ex vivo viability testing of kidneys after postmortem warm ischemia.
AB - Future approaches to expand the organ donor pool with marginal and
nonheartbeating donors, will be dependent upon prospective organ evaluation.
Restoration of metabolism by preservation at warmer temperatures could
potentially provide the window for such evaluation. Using a small bovine model,
kidneys were subjected to either < 15, < 30 or < 60 minutes of warm ischemia (WI)
followed by cold ischemia (CI) in ViaSpan. After WI and CI, kidneys were
transitioned to a warm temperature perfusion (30 degrees C to 32 degrees C) using
exsanguinous metabolic support (EMS) technology. Restored renal metabolism and
function was assessed by oxygen consumption, glucose consumption, urine
production, glomerular filtration rate, and hemodynamic characteristics. The
results of this study suggest that it is feasible to distinguish viable from
nonviable organs ex vivo by assessing renal metabolism and function during warm
preservation using EMS technology.
PMID- 10667720
TI - Variable flow Doppler for hemodialysis access evaluation: theory and clinical
feasibility.
AB - Access thrombosis remains an enormous problem for patients on hemodialysis.
Current evidence suggests that decreasing access blood flow rate is an important
predictor of future access thrombosis and failure. This article describes a
method for determining access volume flow and detecting access pathology. The
Doppler ultrasound signal downstream from the arterial needle as a function of
the variable hemodialysis blood pump flow rate, is used to determine access blood
flow. By using this variable flow (VF) Doppler technique compared with duplex
volume flow estimates measured in 18 accesses (16 patients with 12
polytetrafluorethylene [PTFE] grafts and 6 autogenous fistulas), the results
showed a correlation of 0.83 (p < 0.0001) between these methods. In grafts with
lower blood flow rates, aberrant flow patterns were observed, including stagnant
or reversed flow during diastole while forward flow was maintained during
systole. When reversed diastolic flow was severe, it was accompanied by access
recirculation. In conclusion, we report the theory and clinical feasibility of
determining access blood flow by using a VF Doppler technique. Measurements are
made without the need to determine the access cross sectional area required for
duplex volume flow calculations and without the need to reverse the lines
required for various indicator dilution techniques. Important information is also
obtained about aberrant flow patterns in patients at risk of access failure.
PMID- 10667721
TI - A microdomain-structured synthetic high-flux hollow-fiber membrane for renal
replacement therapy.
AB - A prospective crossover clinical study evaluated solute removal and
biocompatibility of a tailored, hydrophobic-hydrophilic microdomain structure
produced from a blend of polyamide, polyarylethersulfone, and
polyvinylpyrrolidone (Polyflux) compared with Fresenius Polysulfone in dialyzers
of similar surface area. The clearance of small molecules (urea, creatinine, and
phosphate) for both membranes was comparable. Plasma levels of beta2
microglobulin were reduced at the end of treatment with both membranes (49.8% of
pretreatment values for Polyflux; 45.9%, Fresenius Polysulfone) and was
associated with the recovery of 207 +/- 84 mg of beta2 microglobulin from the
dialyzing fluid for Polyflux compared with 147 +/- 29 for Fresenius Polysulfone
(p = 0.12). The dialyzing fluid also contained 7,758 mg of protein when using
Polyflux compared with 7,793 mg using Fresenius Polysulfone (standard error of
difference for any pair was 511 mg). No albumin was present in the dialysis fluid
for either membrane. Neutropenia, platelet adhesion to the membrane, and
complement activation characterized by C3a, C5a, and SC5b-9 generation were
slight and independent of membrane type. Membrane thrombus generating potential
measured by thrombin:antithrombin III were also similar. These results indicate
that the tailored, hydrophobic-hydrophilic microdomain structure of the membrane
results in a favorable biocompatibility profile and clinically acceptable solute
removal similar to the widely used Fresenius Polysulfone membrane.
PMID- 10667722
TI - Dependence of peritoneal clearances on body size in continuous ambulatory
peritoneal dialysis: effect of the normalizing size indicator.
AB - In peritoneal dialysis (PD), small solute clearances are normalized by body water
(V) and body surface area (BSA). The purpose of this study was to identify if V
or BSA produced stronger associations between body size and normalized
clearances. We studied the relationship between four size indicators (V, BSA,
height, and weight) and either peritoneal urea clearance normalized to V
(Kt/V(ur)) and BSA (C(ur)) or creatinine clearance normalized to V (Kt/V(cr)) and
BSA (C(cr)). A total of 613 clearance studies were performed in subjects on
continuous ambulatory peritoneal dialysis (CAPD) with four daily exchanges and a
2 L fill volume. As size increased, the normalized peritoneal clearances
decreased in a nonlinear fashion (regression: y = b0 + b1x(-1), where x is a size
indicator and y is a normalized clearance). Significant (p < 0.001) negative
correlations were found between each normalized clearance and each size
indicator. However, in each case, the correlation was higher when V, rather than
BSA, was used. For example, BSA correlated more closely with K/V(ur)(-0.660) than
C(ur)(-0.556), and also with Kt/V(cr)(-0.579) than C(cr)(-0.446). Normalized
clearances are smaller in large subjects on CAPD because one mathematic
determinant of the clearance, the drain volume (Dv) normalized by V (Dv/V) or BSA
(DV/BSA), decreases as size increases. The relationship between Dv/V or Dv/BSA
and the size indicators was studied by the same nonlinear regression model. The
correlations of the size indicators with Dv/V were also consistently higher than
the corresponding correlations with Dv/BSA. In subjects who were on the same PD
schedule, the dependence of clearances on size was consistently higher when V,
rather than BSA, was the normalizing parameter. Because prescription of the dose
of PD is based on body size, there is a practical advantage by using V as the
sole normalizing parameter for both urea and creatinine clearance.
PMID- 10667723
TI - Simulation study of the intercompartmental fluid shifts during hemodialysis.
AB - Hypotension is the most frequent complication during hemodialysis. An important
cause of hypotension is a decrease in the intravascular volume. In addition, a
decrease in plasma osmolality may be a contributing factor. Modeling of sodium
and ultrafiltration (UF) may help in the understanding of underlying
relationships. We therefore simulated, in a mathematical model, the
intercompartmental fluid shifts during standard hemodialysis (SHD), diffusive
hemodialysis (DHD), and isolated ultrafiltration (IU). We analyzed the relative
theoretical effect of hydration status, dialysate sodium concentration, the
initial plasma concentrations of sodium and urea, and tissue permeation to
solutes on the magnitude and direction of intracellular and intravascular volume
changes. This theoretical analysis shows that the transcellular fluid shifts
taking place during hemodialysis treatment are, to a great part, due to
inhomogeneous distribution of regional blood flow and tissue fluid volumes.
During hemodialysis treatment, the cellular fluid shifts in tissue groups with
relatively high perfusion and small volume occur from the intra- to the
extracellular spaces. However, the fluid shift in tissue groups with a low
perfusion and large volume takes place in the opposite direction. The UF volume
and rates, and the size of the sodium (Na+) gradient between the dialysate and
blood side of the dialyzer membrane are the most important factors influencing
the fluid shifts. Higher UF volumes and flow rates cause an increasing decline in
the plasma volume in both SHD and IU. High dialysate sodium concentration (150
mEq L(-1)) helps plasma refilling slightly when compared with a normal dialysate
sodium concentration (140 mEq L(-1)). However, a high dialysate sodium
concentration is associated with a high plasma sodium rebound, which in turn may
lead to interdialytic water intake resulting from thirst and may cause increased
weight gain and hypertension.
PMID- 10667724
TI - Solute removal characteristics of continuous recirculating peritoneal dialysis in
experimental and clinical studies.
AB - Continuous recirculating peritoneal dialysis (CRPD) was introduced to enhance
solute removal efficiency in conventional peritoneal dialysis (PD) therapies such
as continuous ambulatory peritoneal dialysis (CAPD). In CRPD, a portion of the
dwell dialysate in the patient's peritoneal cavity is drained through a double
lumen catheter and purified by an extracorporeal dialyzer. In this study, solute
removal characteristics and safety of CRPD are examined in ex vivo and clinical
studies. Recirculation dialysis experiments using nine dogs (13.6 +/- 2.5 kg of
body weight) were carried out for 240 min in the ex vivo study, whereas another
seven dogs (12.1 +/- 2.8 kg) received conventional peritoneal dialysis (CPD) (120
min dwelling x 2) and six additional dogs (11.9 +/- 2.7 kg) received a Tidal PD
(20 min dwelling x 12; 50% of tidal volume ratio) as controls. The ex vivo study
revealed that CRPD has a higher efficiency for solute removal than CPD and is
equivalent to Tidal PD. In the BUN reduction rate, the 19.4 +/- 5.5% in 240 min
CRPD (n = 9) was significantly higher (p < 0.05) than the 3.5 +/- 3.6% in 240 min
CPD (n = 7) and equivalent to the 17.3 +/- 4.7% in 240 min Tidal PD (n = 6).
Continuous recirculating peritoneal dialysis maintained a low UN level in the
peritoneal cavity due to dialysis with an extracorporeal dialyzer. This tendency
was also seen in creatinine removal. In the clinical study, CRPD (n = 10) and CPD
(n = 5) treatments were used in three renal failure patients. Higher solute
removal efficiency was shown in CRPD than in CPD treatments, and the urea
peritoneal clearance was 14.1 +/- 4.4 ml/min in CRPD (n = 10), significantly
higher (p < 0.05) than the 7.3 +/- 2.1 ml/min in CPD (n = 5). No fibrin formation
occurred during CRPD treatments.
PMID- 10667725
TI - Internal mammary artery harvesting using the harmonic scalpel.
AB - Internal mammary artery (IMA) harvesting using the harmonic scalpel (HS) was
recently introduced. We studied 541 IMAs harvested by the same surgeon through a
standard median sternotomy in 472 coronary bypass patients; 252 (47%) with the
HS, while 289 (53%) were with electrocautery (EC). Patient demographics included
mean ages: 67 years HS vs. 65 years EC (p = NS); male:female ratio: 3:1; and
insulin dependent diabetes mellitus (IDDM): 11% HS vs. 12.5% EC (NS). Mean
ultrasonic IMA flow at a mean SBP of 70 mm Hg in 10 consecutive patients of each
group were: preharvest, HS 11.9 +/- 2.3 ml/min vs. EC 8.5 +/- 1.6 ml/min (p =
0.256); postharvest, HS 35.7 +/- 10.7 ml/min vs. EC 22 +/- 2.9 ml/min (0.235);
and postcardiopulmonary bypass (post-CPB), HS 47.8 +/- 6.2 ml/min vs. EC 41.7 +/-
2.5 ml/min (0.381). Histologic samples of 50 consecutive IMAs showed no evidence
of vessel injury in either group. Clinical results revealed postoperative
bleeding in 6/217 (2.7%) HS vs. 7/255 (2.7%) EC (p = 0.783), none attributed to
bleeding from the IMA; phrenic paresis: 0/217 in HS but 1/255 (0.4%) in EC (p =
0.960); sternal wound infection: 5/217 (2.3%) HS vs. 6/255 (2.4%) EC (p = 0.787);
postoperative IABP: 6/217 (2.7%) HS vs. 5/255 (2%) EC (p = 0.859); mortality:
2/217 (0.9%) HS vs. 2/255 (0.8%) EC (p = 0.710). Hemodynamic, histologic, and
clinical results were comparable in both groups. The authors believe the HS is
safe and effective for IMA harvesting.
PMID- 10667726
TI - Monitoring regional cerebral oxygen saturation using near-infrared spectroscopy
during pulsatile hypothermic cardiopulmonary bypass in a neonatal piglet model.
AB - Impairment of cerebral oxygenation in neonates and infants after hypothermic
nonpulsatile cardiopulmonary bypass (CPB) support is well documented. The
objectives of this study were: 1) using a neonatal piglet model to continuously
monitor the regional cerebral oxygen saturation (rSO2) by near-infrared
spectroscopy during pulsatile hypothermic CPB; and 2) to quantify the pulsatile
flow in terms of energy equivalent pressure (EEP). After initiation of CPB, all
piglets (n = 5) were subjected to 15 minutes of core cooling, reducing the rectal
temperature to 25 degrees C, followed by 60 minutes of hypothermic CPB, then 10
minutes of cold reperfusion, and 30 minutes of rewarming. During CPB, mean
arterial pressures (MAPs) and pump flow rates were maintained at 40-45 mm Hg and
150 ml/kg/min, respectively. During normothermic CPB, the rSO2 was significantly
increased, compared with the pre-CPB level (56.8 +/- 5.2% vs. 41.8 +/- 5.5%, p <
0.01). At the end of cooling, the rSO2 level was 76.8 +/- 8.6% (p < 0.001 vs. pre
CPB). After 60 minutes of hypothermic CPB and 30 minutes of rewarming, the rSO2
level was decreased to 38.6 +/- 4.2%, which was not significantly different
compared with the pre-CPB level. The average increase in pressure (from MAP to
EEP) was 5 +/- 1%, and the average increase in extracorporeal circuit pressure
(from ECCP to EEP) was 13 +/- 2%. This extra pressure may help to provide better
regional cerebral oxygen saturation. During pulsatile CPB, there was no rSO2
deficiency in this high flow model. Near-infrared spectroscopy responded well to
changes in rSO2 during different stages of these experiments and might be a
helpful tool for intraoperative monitoring.
PMID- 10667727
TI - Evaluation of biodegradable, three-dimensional matrices for tissue engineering of
heart valves.
AB - A crucial factor in tissue engineering of heart valves is the type of scaffold
material. In the following study, we tested three different biodegradable
scaffold materials, polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), and poly
4-hydroxybutyrate (P4HB), as scaffolds for tissue engineering of heart valves. We
modified PHA and P4HB by a salt leaching technique to create a porous matrix. We
constructed trileaflet heart valve scaffolds from each polymer and tested them in
a pulsatile flow bioreactor. In addition, we evaluated the cell attachment to our
polymers by creating four tubes of each material (length equals 4 cm; inner
diameter, 0.5 cm), seeding each sample with 8,000,000 ovine vascular cells, and
incubating the cell-polymer construct for 8 days (37 degrees C and 5% CO2). The
seeded vascular constructs were exposed to continuous flow for 1 hour. Analysis
of samples included DNA assay before and after flow exposure, 4-hydroxyproline
assay, and environmental scanning electron microscopy (ESEM). We fabricated
trileaflet heart valve scaffolds from porous PHA and porous P4HB, which opened
and closed synchronously in a pulsatile bioreactor. It was not possible to create
a functional trileaflet heart valve scaffold from PGA. After seeding and
incubating the PGA-, PHA-, and P4HB-tubes, there were significantly (p < 0.001)
more cells on PGA compared with PHA and P4HB. There were no significant
differences among the materials after flow exposure, but there was a
significantly higher collagen content (p < 0.017) on the PGA samples compared
with P4HB and PHA. Cell attachment and collagen content was significantly higher
on PGA samples compared with PHA and P4HB. However, PHA and P4HB also demonstrate
a considerable amount of cell attachment and collagen development and share the
major advantage that both materials are thermoplastic, making it possible to mold
them into the shape of a functional scaffold for tissue engineering of heart
valves.
PMID- 10667728
TI - The effect of diastolic stiffness on ventricular function after partial
ventriculectomy: a finite element simulation.
AB - Partial ventriculectomy (PV) has been proposed by Batista and colleagues to
improve cardiac function in patients with dilated cardiomyopathy (DCM); however,
results have been mixed. We tested the hypothesis that preoperative diastolic
function affects the stroke volume/end-diastolic pressure (Starling) relationship
after PV. A previously described finite element simulation of DCM and PV was
used. Diastole and end systole were represented by separate elastic finite
element models with different unloaded shapes and nonlinear material properties.
Left ventricular (LV) end-systolic elastance (E(ES)), diastolic compliance (DC),
and Starling relationships were calculated. DC was varied by changing Ogden
material property alpha(i) from 12 (compliant) to 20 (stiff). PV was simulated at
20% LV mass reduction. The slope of the Starling relationship increased from 1.82
to 1.21 as alpha(i) increased from 12 to 20. Partial ventriculectomy increased
the Starling relationship in each case from 1.34 to 1.01 respectively. However,
the net result in each case is a decrement in the Starling relationship with
resection, and the smallest decrement was associated with the highest diastolic
stiffness (alpha(i) = 20). Partial ventriculectomy depressed the Starling
relationship for all values of diastolic compliance. It is expected that patients
with a higher diastolic stiffness should do better.
PMID- 10667729
TI - Terumo implantable left ventricular assist system: results of long-term animal
study.
AB - The research group of Terumo Corporation, NTN Corporation, and the Setsunan
University have been developing an implantable left ventricular assist system (T
ILVAS) featuring a centrifugal blood pump with a magnetically suspended impeller
(MSCP). The present study describes results of chronic animal experiments using
the MSCP. The MSCP has been tested ex vivo and in vivo in 6 sheep as a left heart
bypass between the left ventricular apex and descending aorta. Ex vivo chronic
sheep experiments using Model I demonstrated long-term durability,
nonthrombogenicity, low hemolysis (<6 mg/dl), and excellent stability of the
magnetic bearing with long-term survival for up to 864 days. Average pump flow
rate was 4 L/min at a fixed rotational speed of 2000 rpm. Power spectral analyses
of heart rate, aortic pressure, and blood temperature maintained normal 1/f
fluctuation during the study. The retrieved pump was completely free from
thrombus formation and there was no evidence of infarct in major organs. The
implantable Model II was evaluated ex vivo in two sheep and intra-thoracically
implanted in a sheep. These experiments were terminated at 70, 79, and 17 days
due to blood leakage through the connector system within the housing. No thrombus
formation was observed in any of the retrieved pumps. A modified Model II with a
new connector system was subsequently intra-thoracically implanted in a sheep.
The sheep survived for 482 days without any sign of thromboembolic complication
or hemolysis at a fixed rotational speed of 1700 rpm and an average pump flow
rate of 5 L/min. There was no intra-device thrombus formation or infarct in major
organs. The Model III system, consisting of an implantable controller and a new
MSCP with a reduced input power of 13 W, has been developed and implanted in a
chronic sheep model. The MSCP was implanted in the left pleural space and the
controller in the abdominal wall. The experiment is still in progress for more
than 30 days without any significant complication to date. These animal studies
strongly suggest the feasibility of the MSCP for use as long-term circulatory
assist.
PMID- 10667730
TI - Development of an antithrombogenic and antitraumatic blood pump: the Gyro C1E3.
AB - The Gyro C1E3 is a centrifugal blood pump. Its antithrombogenic and antitraumatic
blood features were demonstrated by prior studies. Based upon these studies, a
mass production model of the C1E3 is becoming commercially available. Therefore,
this feasibility study was conducted using the mass production models of the Gyro
C1E3 for long-term cardiac assist in ex vivo animal experiments. Five healthy
calves were used and 15 pump heads were applied for different time periods (Group
1, 30 days; Group 2, 14 days; Group 3, 10 and 7 days; Group 4, 4 days; and Group
5, 2 days). Activated clotting time (ACT) was kept at 200-250 sec. All five
calves demonstrated neither abnormal signs nor abnormal blood examination data
throughout the experiment. During necropsy, no thromboembolism was found in any
downstream organs. Groups 1-4 showed thrombi inside the pump heads while two
pumps in Group 5 had no thrombi formations. Bearing deformation or possible wear
did not increase after 2 days of pumping. The C1E3 is capable of long-term assist
circulation. However, after 2 days of pumping, careful observation is necessary
since thrombi may occur inside the pump when ACT is controlled under 250 sec.
During the weaning stage or low flow (under 2 L/min), over 250 sec of ACT is
recommended to assure the safety of the patient.
PMID- 10667731
TI - Clinical evaluation of the Gyro Pump C1E3 as a cardiopulmonary bypass pump.
AB - The Gyro Pump C1E3 is a new centrifugal pump with numerous features, including a
ceramic pivot bearing system, secondary vanes, and an eccentric inlet port. To
evaluate its biocompatibility, antithrombogenicity, and produced hemolysis, we
used the Gyro Pump during cardiopulmonary bypass (CPB) for coronary artery bypass
grafting (CABG) cases to compare it with the BioMedicus pump. From September 1998
to February 1999, 30 consecutive patients underwent CABG under conventional CPB.
Fifteen patients were supported by the Gyro Pump C1E3 (Group G), and the
remaining 15 patients, by a BioMedicus BP-80 pump (Group B). In both groups, flow
rate was equivalent. Blood samples were taken as follows: preoperative, 60
minutes after the end of the procedure, and at postoperative days (POD) 0, 1, and
2. We evaluated the plasma free hemoglobin (free Hb) as an indication of
hemolysis; beta-thromboglobulin (beta-TG) and platelet factor four (PF-4) as an
indication of platelet deterioration; C3, C4, CH50 for complement activation;
coagulation parameters, fibrinolytic factor, thrombomodulin, nitric oxide (NO),
and endothelin as an indication of endothelial deterioration. This was the first
clinical sized Gyro Pump CIE3. De-airing from the pump was easily accomplished
via the eccentric oblique inlet port. The system, including its console, was
easily and simply controlled. Perioperative laboratory data were not markedly
changed in either group with demonstrated equivalence for biocompatibility and
hemolysis. After pumping, no thrombus formation or pivot wear were observed
inside the pump. This atraumatic, small centrifugal pump appears well suited not
only for CPB but also for circulatory support.
PMID- 10667732
TI - Application of a new dynamic flow model for investigating the biocompatibility of
modified surfaces.
AB - An in vitro model was developed to compare the biocompatibility of four different
coating methods (three heparin and one nonheparin) under hemodynamic conditions.
Fresh human donor blood (heparin 5 IU/ml) was recirculated in a standardized
experimental circuit. All circuit components were either coated or remained
uncoated for control purposes. The aim of the study was to investigate a wide
spectrum of effects on blood; coagulation parameters (e.g., fibrinogen, ATIII,
thrombin-antithrombin-complex), complement parameters (C1rsC1 Inh, C3b(Bb)P, SC5b
9, C5a), differential blood analyses, platelet activation (flow cytometric
investigations), PF 4, and PMN-elastase release were examined by showing possible
trends. All heparin coated systems reduced platelet stimulation in comparison to
untreated biomaterials. Leukocyte activation was reduced to different degrees
depending upon the coating method used. Complement activation was markedly
reduced by all coated systems. The results obtained indicate that the pump
driven, dynamic blood flow model is suitable to characterize the biocompatibility
of surface modified biomaterials. Advantages lie in the integration of the
different polymers as parts of the circuit, the low priming volume, and the
generation of blood flow conditions similar to those that occur in clinical
applications.
PMID- 10667733
TI - Abnormal electrical stimulus of an intra-aortic balloon pump with concurrent
support with continuous veno-venous hemodialysis.
AB - Malfunction of electronic medical support apparatus utilized in the ICU usually
causes system failure. We report several occurrences of a potentially dangerous
interaction between a continuous veno-venous hemodialysis (CVVHD) system and an
intra-aortic balloon pump (IABP) counterpulsation device in four patients
requiring both systems. The patients had acute renal failure in the face of multi
organ failure and were dependent upon the balloon pump for pressure support.
Electrical interference created by the roller pump action of the CVVHD system was
identified by the balloon pump as cardiac in origin, and it responded by
inflation and deflation. As the blood pump rate was reduced, the interference
reduced to the point of complete cessation when the blood pump was shut down.
Whereas one patient transiently had a significant drop of mean arterial pressure
(from 70 +/- 4 to 40 +/- 2 mm Hg) the other observed occurrences had no
clinically significant sequelae. Electrocardiogram (ECG) tracings identified the
abnormal stimulus and systematic review identified as potential sources for the
creation of this interference static electricity buildup, piezoelectric
properties of the polyvinyl chloride tubing, and, possibly but less likely,
radiofrequency interference. A newer generation ECG cable and advanced cardiac
rhythm recognition software (CardioSync) have been introduced with the Datascope
System 98, and the ECG interference, although still occasionally present, does
not cause erratic inflation and deflation of the intra-aortic balloon pump.
Interference between different electrical support systems may occur, and we
suggest that the systems be tested for compatibility before combined use and that
older equipment be more rigorously tested for potential clinically significant
interference.
PMID- 10667734
TI - Life-threatening acute systemic lupus erythematosus: survival after multiple
extracorporeal modalities: a place for the multipotential extracorporeal service.
AB - Diffuse alveolar hemorrhage secondary to systemic lupus erythematosus (SLE) may
cause life-threatening respiratory failure and may be associated with multiple
organ failure. Extensive support may be necessary to sustain life while systemic
therapy becomes effective. We report here a patient with profound respiratory
failure secondary to SLE associated with multiorgan failure, who was supported
with veno-arterial extracorporeal lung assist (ECLA), veno-venous ECLA, and
multiple continuous renal replacement therapies during plasmapheresis. The full
spectrum of extracorporeal life support and treatment modalities was performed
seamlessly by a single service within the critical care department.
PMID- 10667735
TI - Physiology of nonpulsatile circulation: acute versus chronic support.
PMID- 10667736
TI - At issue: schizophrenia and rheumatoid arthritis: the negative association
revisited.
AB - A strong negative association between schizophrenia and rheumatoid arthritis
(RA), implying low comorbidity, has been found in 12 of 14 previous studies,
which we review. To this literature we add two recently acquired data sets
encompassing 28,953 schizophrenia patients, only 31 of whom had comorbid RA.
Integrating our new data into those of the previous nine studies, which
stratified their populations according to psychiatric diagnosis, we obtain a
median frequency of RA in schizophrenia populations of 0.09 percent and a mean
frequency of 0.66 percent, well below the expected range of 1 percent. These data
robustly support prior studies. We also present a meta-analysis evaluating the
association between the two diseases by integrating information derived from nine
data sets, each furnishing an estimate of the relative risk of RA in
schizophrenia patients versus that in other psychiatric patients. We find that
the estimated rate of RA among schizophrenia patients is only 29 percent of the
corresponding rate in other psychiatric patients. Further, the relative risk of
RA in schizophrenia patients versus that in the general population is even less
than 29 percent and could be as low as one-third of this value. We present a new
hypothesis involving the platelet activating factor system in an effort to
account for this negative association and review the suggestions of other
investigators toward this end. Finally, we consider the glutamatergic system
dysfunction hypothesis of schizophrenia and suggest a possible common
pharmacological approach that may ameliorate some of the symptomatology of both
schizophrenia and RA.
PMID- 10667737
TI - Schizophrenia: an epigenetic puzzle?
AB - Developments in molecular biology over the past three decades have led to an
increasing awareness of the importance of epigenetic phenomena in a variety of
genome functions. Epigenetic aspects of complex multifactorial diseases including
schizophrenia, however, have not been investigated sufficiently. Various facets
of epigenetics are reevaluated through their putative relevance to four theories
of schizophrenia: neurodevelopmental, dopamine dysfunction, viral, and genetic
anticipation with unstable DNA. The heuristic value of the epigenetic model of
schizophrenia arises from the possibility of integration of a wide variety of
empirical data into a new theoretical framework. It can be hypothesized that in
addition to pathological effects of DNA structural mutations and environmental
factors, inherited and acquired epigenetic defects, or epimutations, may be of
etiological importance in schizophrenia. In addition, the epigenetic model may
lead to experiments investigating the molecular substrates of genetic
environmental interactions.
PMID- 10667738
TI - Effects of cognitive treatment in psychiatric rehabilitation.
AB - Ninety subjects with severe and disabling psychiatric conditions, predominantly
schizophrenia, participated in a controlled-outcome trial of the cognitive
component of Integrated Psychological Therapy (IPT), a group-therapy modality
intended to reestablish basic neurocognitive functions. The cognitive therapy was
delivered to subjects in the experimental condition during intensive 6-month
treatment periods. Control subjects received supportive group therapy. Before,
during, and after the intensive treatment period, all subjects received an
enriched regimen of comprehensive psychiatric rehabilitation, including social
and living skills training, optimal pharmacotherapy, occupational therapy, and
milieu-based behavioral treatment. IPT subjects showed incrementally greater
gains compared with controls on the primary outcome measure, the Assessment of
Interpersonal Problem-Solving Skills, suggesting that procedures that target
cognitive impairments of schizophrenia spectrum disorders can enhance patients'
response to standard psychiatric rehabilitation, at least in the short term, in
the domain of social competence. There was equivocal evidence for greater
improvement in the experimental condition on the Brief Psychiatric Rating Scale
disorganization factor and strong evidence for greater improvement on a
laboratory measure of attentional processing. There was significant improvement
in both conditions on measures of attention, memory, and executive functioning,
providing support for the hypothesis that therapeutic procedures that target
impaired cognition enhance response to conventional psychiatric rehabilitation
modalities over a 6-month timeframe.
PMID- 10667739
TI - Developmental theory for a cognitive enhancement therapy of schizophrenia.
AB - Recent findings on psychosocial and neurodevelopmental anomalies in schizophrenia
patients indicate that deficits related to social cognition-the ability to act
wisely in social interactions-may be important constraints on complete social and
vocational recovery. Social cognition is acquired over many decades and appears
to be partially independent of formal IQ and neuropsychological problems. It
invites a more developmental approach to the rehabilitation of schizophrenia, one
that we call Cognitive Enhancement Therapy (CET). CET draws on an emerging
literature that implicates both pre- and postonset neurodevelopmental
difficulties, as well as a complementary literature on diffuse neuropsychological
impairments that supports the notion of a neurodevelopmental insult. We analyzed
evidence for an associated developmental basis to social cognitive impairment in
the context of a model that addressed both the acquisition of interpersonal
wisdom and the adaptive process that might follow developmental failures. A
contemporary model of human cognition is then used to identify the metacognitive
functions that characterize the developmental acquisition of normal cognition
and, by inference, the associated difficulties of many patients with
schizophrenia. A rehabilitation strategy for schizophrenia, designed to
facilitate the metacognitive transition from prepubertal to young adult social
cognition, would thus emphasize developmental learning experiences during the
remediation of social cognitive deficits. A "gistful" appraisal of interpersonal
behavior and novel social contexts best reflects the theoretical intent of this
new intervention.
PMID- 10667740
TI - Practice principles of cognitive enhancement therapy for schizophrenia.
AB - Cognitive Enhancement Therapy (CET) is a developmental approach to the
rehabilitation of schizophrenia patients that attempts to facilitate an
abstracting and "gistful" social cognition as a compensatory alternative to the
more demanding and controlled cognitive strategies that often characterize
schizophrenia as well as much of its treatment. Selected cognitive processes that
developmentally underlie the capacity to acquire adult social cognition have been
operationalized in the form of relevant interactive software and social group
exercises. Treatment methods address the impairments, disabilities, and social
handicaps associated with cognitive styles that appear to underlie the positive,
negative, and disorganized symptom domains of schizophrenia. Style-related
failures in secondary rather than primary socialization, particularly social
cognitive deficits in context appraisal and perspective taking, are targeted
goals. Illustrative examples of the techniques used to address social and
nonsocial cognitive deficits are provided, together with encouraging preliminary
observations regarding the efficacy of CET.
PMID- 10667741
TI - How long to wait for a response to clozapine: a comparison of time course of
response to clozapine and conventional antipsychotic medication in refractory
schizophrenia.
AB - This study compared the time course to clinical improvement with clozapine and
with conventional antipsychotic medications. A double-blind trial compared
clozapine and haloperidol in patients with schizophrenia who were refractory to
conventional antipsychotic medication and were hospitalized for 30 to 364 days at
15 Veteran Affairs medical centers during the year before study entry. Patients
in the original study were randomly assigned to haloperidol or clozapine and
followed for 12 months, at maximum tolerable doses. Patients who completed a full
year of treatment with clozapine (n = 122), or with either haloperidol or another
conventional antipsychotic medication (n = 123) and who also completed the 9- or
12-month assessment were included. Response to treatment was defined as 20
percent improvement on standard scales of symptoms and quality of life at the
latter of the 9- or 12-month interviews. More patients assigned to clozapine
achieved 20 percent improvement in symptoms at each followup. Among patients who
did not improve at 6 weeks, 3 months, or 6 months, there were no significant
differences between clozapine and comparison patients in outcomes at 1 year.
Among patients who did improve, maintenance of that improvement also did not
differ between the groups at 1 year on symptom measures. Maintenance of
improvement in quality of life at 1 year was significantly greater for clozapine
patients who had improved at 6 months (p < 0.04). Significant differential
symptom response to clozapine occurred exclusively during the first 6 weeks of
treatment.
PMID- 10667742
TI - Risperidone in the treatment of first-episode psychotic patients: a double-blind
multicenter study. Risperidone Working Group.
AB - An international, multicenter, double-blind study was conducted in 183 patients
with a first psychotic episode (provisional schizophreniform disorder or
schizophrenia; DSM-III-R) treated with flexible doses of risperidone or
haloperidol for 6 weeks. At endpoint, 63 percent of risperidone-treated patients
and 56 percent of haloperidol-treated patients were clinically improved (> or =
50% reduction in Positive and Negative Syndrome Scale total scores). Risperidone
was better tolerated than haloperidol: the severity of extrapyramidal symptoms
was significantly lower in the risperidone-treated patients; significantly fewer
risperidone-treated patients required antiparkinsonian medication; and
significantly fewer discontinued treatment because of adverse events. A post hoc
analysis revealed that low doses of these antipsychotics were efficacious in some
patients. Furthermore, the severity of extrapyramidal symptoms and the use of
antiparkinsonian medications were significantly lower in patients receiving low
doses (maximum, < or = 6 mg/day) than high doses (maximum, > 6 mg/day) of
risperidone or haloperidol. These findings are consistent with the suggestion
that patients with a first psychotic episode may require low doses of
antipsychotic medications. Studies designed specifically to compare low and high
doses of antipsychotics are warranted to help optimize treatment for these
patients.
PMID- 10667743
TI - Tardive dyskinesia: possible involvement of free radicals and treatment with
vitamin E.
AB - A decade ago a hypothesis introduced to explain tardive dyskinesia (TD)
implicated free radicals generated secondary to neuroleptic treatment. Since then
many preclinical and clinical studies have investigated this possibility. These
studies suggest that free radicals are probably involved in the pathogenesis of
TD and that vitamin E could be efficacious in its treatment.
PMID- 10667744
TI - Tardive dystonia.
AB - This paper provides an overview of the phenomenology, epidemiology, and treatment
of tardive dystonia. Tardive dystonia is one of the extrapyramidal syndromes that
starts after long-term use of dopamine receptor antagonists. The diagnosis is
based on the presence of chronic dystonia, defined as a syndrome of sustained
muscle contractions, frequently causing twisting and repetitive movements or
abnormal postures. Furthermore, dystonia must develop either during or within 3
months of a course of antipsychotic treatment, and other causes such as Wilson's
disease, acute dystonia, or a conversion reaction must be ruled out. Tardive
dystonia occurs in about 3 percent of patients on long-term antipsychotic
treatment. Some probable risk factors for tardive dystonia are younger age, male,
and the presence of tardive dyskinesia. The treatment of tardive dystonia starts
with an evaluation of the need for using the causative drug. If antipsychotics
must be continued, a switch to an atypical antipsychotic, particularly clozapine,
may be helpful. If the dystonia is relatively localized, botulinum toxin is an
effective but not well-known treatment possibility. If tardive dystonia is more
extensive, either dopamine-depleting drugs or high dosages of anticholinergics
can be tried.
PMID- 10667745
TI - The "benefits" of distractibility: mechanisms underlying increased Stroop effects
in schizophrenia.
AB - Recent studies of selective attention in schizophrenia patients suggest a
particular pattern of single-trial Stroop performance: increased facilitation but
not interference in reaction times (RTs), combined with increased error
interference. Our Stroop task analysis suggests that this pattern can be
explained by a selective attention deficit if one accounts for (1) performance in
the congruent condition; (2) the nature of the neutral stimulus; (3) the
relationship between accuracy and RT; and (4) response set effects. To test these
hypotheses, we examined Stroop performance in 40 DSM-IV schizophrenia patients
and 20 healthy control subjects, using a range of neutral stimuli (color patches,
noncolor words, color words not in the response set). The findings confirmed
several of our predictions and the results were consistent with the hypothesis
that abnormal Stroop performance in schizophrenia reflects a failure to
adequately attend to the task-appropriate stimulus dimension (color). This
inattention affects both the congruent and incongruent conditions and multiple
points in the information processing pathway.
PMID- 10667747
TI - Sensory gating in rats: lack of correlation between auditory evoked potential
gating and prepulse inhibition.
AB - This study was designed to evaluate the possible similarities between two
paradigms designed to measure sensory gating: (1) an auditory evoked potential
(AEP), called the P50 gating paradigm; and (2) an acoustic startle (ASR), called
the prepulse inhibition paradigm. These paradigms show a number of
methodological, pharmacological, and neurobiological similarities, and they are
both disturbed in patients with schizophrenia. In the first of three experiments,
the AEP gating and the ASR gating were measured in rats. Although both AEP and
ASR gating could readily be obtained, there appeared to be no correlation between
the performance in these two paradigms. This lack of correlation was confirmed
using a factor analytical approach, where the AEP gating and the ASR gating
parameters were found to load on different factors. In the second experiment, the
interstimulus interval in the ASR paradigm was increased to 500 ms (identical to
the interstimulus interval of the AEP gating paradigm). This increase reduced the
degree of ASR gating, although some gating could still be obtained. Again no
correlation was found between AEP and ASR gating, and this was again confirmed by
the factorial analysis. In the final experiment, the effects of the dopamine D2/3
agonist 7-OHDPAT were evaluated in both paradigms. This selective agonist dose
dependently reduced ASR gating but had no effect on AEP gating. Together, these
data strongly suggest that AEP and ASR gating measure two different aspects of
information processing and indicate that both paradigms may be important for
investigating the neurobiological disturbances observed in patients with
psychoses.
PMID- 10667746
TI - Panmodal processing imprecision as a basis for dysfunction of transient memory
storage systems in schizophrenia.
AB - Schizophrenia is a severe mental disorder associated with cognitive disturbances
that may reflect underlying deficits in the functioning of brain transient memory
storage systems. This study investigates performance in three distinct tasks that
require transient memory storage: (1) tone discrimination, (2) object weight
discrimination, and (3) "AX"-type visual continuous performance task. The tests
used were chosen to investigate the degree to which a similar pattern of
performance deficit could be observed across multiple sensory and cognitive
domains in schizophrenia. In each of the paradigms, a similar pattern emerged:
subjects with schizophrenia showed severe performance deficits whenever
performance depended on functioning of transient memory systems. The deficits
were apparent at both short and long interstimulus intervals (ISI), however, and
schizophrenia subjects were no more affected by increasing ISI than were
controls. Moreover, when short ISI performance was matched across groups by
manipulating task difficulty, subsequent decay in performance was equivalent
across groups. Thus, although schizophrenia subjects show severe performance
deficits in memory-dependent tasks, the deficits do not appear to reflect
impaired transient memory per se. Rather, they appear to reflect impaired
precision of operation of such systems, irrespective of the duration over which
representations must be maintained. The severe deficits in processing precision,
despite the relatively preserved maintenance of representation, may be relevant
to pathophysiological models of schizophrenia.
PMID- 10667748
TI - An artificial neural network that uses eye-tracking performance to identify
patients with schizophrenia.
AB - Several researchers have underscored the importance of precise characterization
of eye-tracking dysfunction (ETD) in patients with schizophrenia. This biological
trait appears to be useful in estimating the probability of genetic recombination
in an individual, so it may be helpful in linkage studies. This article describes
a nonlinear computational model for using ETD to identify schizophrenia. A back
propagation neural network (BPNN) was used to classify schizophrenia patients and
normal control subjects on the basis of their eye-tracking performance. Better
classification results were obtained with BPNN than with a linear computational
model (discriminant analysis): a priori predictions were approximately 80 percent
correct. These results suggest, first, that eye-tracking patterns can be useful
in distinguishing patients with schizophrenia from a normal comparison group with
an accuracy of approximately 80 percent. Second, parallel distributed processing
networks are able to detect higher order nonlinear relationships among predictor
quantitative measurements of eye-tracking performance.
PMID- 10667749
TI - Premorbid personality in psychoses.
AB - This study aimed to establish correlates of the dimensions of schizophrenia in
the premorbid personality traits of patients. A sample of 112 patients of
relatively recent illness onset who were admitted for a psychotic episode were
assessed with a semistructured interview for schizophrenia. Positive and negative
symptoms were evaluated with the Scale for the Assessment of Positive Symptoms
and the Scale for the Assessment of Negative Symptoms at the time of hospital
discharge; positive, negative, and disorganization scores were obtained from
these scales. Premorbid personality was assessed blindly through a partially
modified version of the Personality Assessment Schedule using interviews with the
parents or a close relative. Schizoid traits were significantly associated with
negative and positive dimensions. Sociopathic traits were related to the
disorganization dimension. Trends toward significance were obtained between
passive-dependent traits and the negative and disorganization dimensions, and
between the schizotypal dimension and the positive dimension. Partial
correlational analyses were used to control for the effect of the remaining
personality dimensions on the above relationships. Schizoid premorbid traits were
still significantly related to the negative dimension but to a lesser degree to
the disorganization and positive dimensions. The association between sociopathic
premorbid traits and the disorganization dimension remained significant. These
results suggest the preexistence of a three-dimensional structure predisposing to
psychoses within the premorbid personality; this structure is more evident in
patients with short illness duration.
PMID- 10667750
TI - Nonresponding schizophrenia: differentiation by neurological soft signs and
neuropsychological tests.
AB - Schizophrenia patients have higher scores on neurological soft-signs (NSS) and
show greater deficits on a variety of neuropsychological tests than normal
control subjects and mixed groups of psychiatric patients. Among chronic
schizophrenia patients it is unclear which of these types of deficits most
strongly differentiates patients who remain consistently symptomatic in spite of
treatment with several conventional neuroleptics (nonresponders) as compared with
relapsing chronic schizophrenia patients who improve substantially with treatment
(relative responders). In this study, 25 nonresponders and 20 relative responders
to conventional neuroleptics were compared on an NSS battery and a limited number
of neuropsychological tests, which evaluated deficits influenced by functioning
of frontal and nonfrontal brain areas. NSS scores showed the largest difference
between relative responders and nonresponders, and statistical analyses suggested
that NSS scores were the strongest differentiator between the two groups of
chronic schizophrenia patients. Scores differentiating the two groups involved
deficits influenced by both frontal and nonfrontal functioning. A predominance of
negative symptoms in the current clinical picture was highly correlated with high
NSS scores.
PMID- 10667751
TI - Familial liability to schizophrenia: a sibling study of negative symptoms.
AB - Negative symptoms are important features in schizophrenia, so in milder form they
might also serve as indicators of "unexpressed" liability to schizophrenia among
patients' adult relatives without schizophrenia. To address this question, we
assessed negative symptoms in 39 stable schizophrenia or schizoaffective
outpatients, 39 of their siblings, 38 well control probands, and 38 of their
siblings. Negative symptom measures included standard behavior ratings of the
core negative symptoms of affective flattening and alogia, as well as a self
report measure of social anhedonia. As expected, even stable outpatients with
schizophrenia exhibited significantly more negative symptoms than control
probands and control siblings. However, negative behavioral symptoms of affective
flattening, alogia, and anhedonia did not significantly differentiate the
siblings of the schizophrenia patients from the control probands or their
siblings, although there were some trends for anhedonia. The findings suggest
that core negative symptoms of observed affective flattening and poverty of
speech are not likely to be useful as strong indicators of "unexpressed"
liability to schizophrenia.
PMID- 10667752
TI - Dimensions of psychosis in affected sibling pairs.
AB - Factor analytical studies of schizophrenia symptoms have consistently suggested
three or more symptom dimensions, but it is not known whether any of these
dimensions have a genetic basis. The purpose of this study was to investigate to
what extent the dimensions show familial aggregation. Symptom ratings were made
using the SAPS and SANS and the OPCRIT checklist on the members of 109 sibling
pairs with DSM-IV schizophrenia or schizoaffective disorder. Factor analyses were
performed on the ratings of both instruments, and correlations were made of
within-pair factor scores. Analyses were also performed on the 89 pairs in which
both members had a diagnosis of schizophrenia. Factor analysis of SAPS and SANS
ratings resulted in positive, negative, and disorganization factors; analysis of
OPCRIT ratings resulted in positive, negative, disorganization, and first-rank
delusion factors. Only the disorganization dimension showed significant within
pair correlations, but these were of modest size and not significantly greater
than the correlations for the other dimensions. None of the dimensions showed
sufficient familial aggregation to suggest that they are close markers of genetic
or common environmental factors that contribute liability to schizophrenia. They
may be weakly associated with such factors and with factors that do not
contribute liability to schizophrenia but do influence the form taken by the
illness.
PMID- 10667753
TI - Communication disturbances in relatives beyond the age of risk for schizophrenia
and their associations with symptoms in patients.
AB - This article provides a detailed examination of subclinical disturbances in the
natural speech of healthy relatives beyond the age of risk for schizophrenia.
Speech samples from 43 stable schizophrenia outpatients, 42 nonschizophrenia
parents of patients (pairs only), and 23 control subjects matched to the parents
were analyzed for frequencies of six specific types of communication failures.
The parents had higher overall communication disturbance ratings than the control
subjects. The specific types of failures that occurred more frequently were
unclarities caused by (1) language structural breakdown, (2) use of vague,
overinclusive words, and (3) use of words with ambiguous meanings. In
intrafamilial analyses, higher levels of communication disturbance in parents
were associated with greater severity of illness in their patient offspring.
These results support the idea that communication disturbances may be one
manifestation of a stable genetic vulnerability to schizophrenia. The nature of
the failures identified suggests the possible involvement of weaknesses in
specific areas of cognitive functioning.
PMID- 10667754
TI - First person account: schizophrenia, substance abuse, and HIV.
PMID- 10667755
TI - Can biological phenomena be understood by humans?
PMID- 10667756
TI - All parties keen to press on with Europe-based science website.
PMID- 10667757
TI - Clinton proposes $2.8 billion increase in science funding.
PMID- 10667758
TI - Yale hopes a $500 million boost will raise research profile.
PMID- 10667759
TI - NIH cancer researchers to get free access to 'OncoMouse'.
PMID- 10667760
TI - Ministries cooperate to plan Japanese genome centre.
PMID- 10667761
TI - Issue of patents on 'Dolly' technology stirs controversy.
PMID- 10667762
TI - US survey reveals location of human tissue samples.
PMID- 10667763
TI - Head of US watchdog faces uncertain future.
PMID- 10667764
TI - Top UK epidemiologist suspended after complaints.
PMID- 10667765
TI - Cell contamination leads to inaccurate data: we must take action now.
PMID- 10667766
TI - Mitchell saw the new vista, if not the details.
PMID- 10667767
TI - Science moves to centre stage.
PMID- 10667768
TI - New approaches to old age.
PMID- 10667769
TI - Pluto story.
PMID- 10667770
TI - Nogo in nerve regeneration.
PMID- 10667771
TI - Palaeoclimatology. Out of Africa.
PMID- 10667772
TI - Harvesting sunlight safely.
PMID- 10667773
TI - One photon seen by one electron
PMID- 10667774
TI - Rice, microbes and methane.
PMID- 10667775
TI - Fluid mechanics. Jets from a singular surface
PMID- 10667777
TI - Volcanic action at Axial Seamount
PMID- 10667776
TI - Evolutionary psychology meets g.
PMID- 10667778
TI - Energy for microbial life on Europa.
PMID- 10667779
TI - A function for guttural pouches in the horse.
PMID- 10667780
TI - Inhibitor of neurite outgrowth in humans.
PMID- 10667781
TI - Creating the narrowest carbon nanotubes.
PMID- 10667782
TI - Nodal signalling in vertebrate development.
AB - Communication between cells during early embryogenesis establishes the basic
organization of the vertebrate body plan. Recent work suggests that a signalling
pathway centering on Nodal, a transforming growth factor beta-related signal, is
responsible for many of the events that configure the vertebrate embryo. The
activity of Nodal signals is regulated extracellularly by EGF-CFC cofactors and
antagonists of the Lefty and Cerberus families of proteins, allowing precise
control of mesoderm and endoderm formation, the positioning of the anterior
posterior axis, neural patterning and left-right axis specification.
PMID- 10667783
TI - A pigment-binding protein essential for regulation of photosynthetic light
harvesting.
AB - Photosynthetic light harvesting in plants is regulated in response to changes in
incident light intensity. Absorption of light that exceeds a plant's capacity for
fixation of CO2 results in thermal dissipation of excitation energy in the
pigment antenna of photosystem II by a poorly understood mechanism. This
regulatory process, termed nonphotochemical quenching, maintains the balance
between dissipation and utilization of light energy to minimize generation of
oxidizing molecules, thereby protecting the plant against photo-oxidative damage.
To identify specific proteins that are involved in nonphotochemical quenching, we
have isolated mutants of Arabidopsis thaliana that cannot dissipate excess
absorbed light energy. Here we show that the gene encoding PsbS, an intrinsic
chlorophyll-binding protein of photosystem II, is necessary for nonphotochemical
quenching but not for efficient light harvesting and photosynthesis. These
results indicate that PsbS may be the site for nonphotochemical quenching, a
finding that has implications for the functional evolution of pigment-binding
proteins.
PMID- 10667784
TI - Probing bulk states of correlated electron systems by high-resolution resonance
photoemission
AB - Electron correlations are known to play an important role in determining the
unusual physical properties of a variety of compounds. Such properties include
high-temperature superconductivity, heavy fermion behaviour and metal-to
insulator transitions. High-resolution photoelectron spectroscopy (PES) provides
a means of directly probing the electronic states (particularly those near the
Fermi level) in these materials, but the short photoelectron mean free paths (<
or = 5 A) associated with the low excitation energies conventionally used (< or =
120 eV) make this a surface-sensitive technique. Now that high-resolution PES is
possible at much higher energies, with mean free paths as long as 15 A (ref. 6),
it should become feasible to probe the bulk electronic states in these materials.
Here we demonstrate the power of this technique by applying it to the cerium
compounds CeRu2Si2 and CeRu2. Previous PES studies of these compounds revealed
very similar spectra for the Ce 4f electronic states, yet it is expected that
such states should be different owing to their differing degrees of hybridization
with other valence bands. Our determination of the bulk Ce 4f electronic states
of these compounds resolves these differences.
PMID- 10667785
TI - Dynamic instabilities and memory effects in vortex matter
AB - The magnetic flux line lattice in type II superconductors serves as a useful
system in which to study condensed matter flow, as its dynamic properties are
tunable. Recent studies have shown a number of puzzling phenomena associated with
vortex motion, including: low-frequency noise and slow voltage oscillations; a
history-dependent dynamic response, and memory of the direction, amplitude
duration and frequency of the previously applied current; high vortex mobility
for alternating current, but no apparent vortex motion for direct currents; and
strong suppression of an a.c. response by small d.c. bias. Taken together, these
phenomena are incompatible with current understanding of vortex dynamics. Here we
report a generic mechanism that accounts for these observations. Our model, which
is derived from investigations of the current distribution across single crystals
of NbSe2, is based on a competition between the injection of a disordered vortex
phase at the sample edges, and the dynamic annealing of this metastable disorder
by the transport current. For an alternating current, only narrow regions near
the edges are in the disordered phase, while for d.c. bias, most of the sample is
in the disordered phase--preventing vortex motion because of more efficient
pinning. The resulting spatial dependence of the disordered vortex system serves
as an active memory of the previous history.
PMID- 10667786
TI - Singularity dynamics in curvature collapse and jet eruption on a fluid surface
AB - Finite-time singularities--local divergences in the amplitude or gradient of a
physical observable at a particular time--occur in a diverse range of physical
systems. Examples include singularities capable of damaging optical fibres and
lasers in nonlinear optical systems, and gravitational singularities associated
with black holes. In fluid systems, the formation of finite-time singularities
cause spray and air-bubble entrainment, processes which influence air-sea
interaction on a global scale. Singularities driven by surface tension have been
studied in the break-up of pendant drops and liquid sheets. Here we report a
theoretical and experimental study of the generation of a singularity by inertial
focusing, in which no break-up of the fluid surface occurs. Inertial forces cause
a collapse of the surface that leads to jet formation; our analysis, which
includes surface tension effects, predicts that the surface profiles should be
describable by a single universal exponent. These theoretical predictions
correlate closely with our experimental measurements of a collapsing surface
singularity. The solution can be generalized to apply to a broad class of
singular phenomena.
PMID- 10667787
TI - A single-photon detector in the far-infrared range
AB - The far-infrared region (wavelengths in the range 10 microm-1 mm) is one of the
richest areas of spectroscopic research, encompassing the rotational spectra of
molecules and vibrational spectra of solids, liquids and gases. But studies in
this spectral region are hampered by the absence of sensitive detectors--despite
recent efforts to improve superconducting bolometers, attainable sensitivities
are currently far below the level of single-photon detection. This is in marked
contrast to the visible and near-infrared regions (wavelengths shorter than about
1.5 microm), in which single-photon counting is possible using photomultiplier
tubes. Here we report the detection of single far-infrared photons in the
wavelength range 175-210 microm (6.0-7.1 meV), using a single-electron transistor
consisting of a semiconductor quantum dot in high magnetic field. We detect, with
a time resolution of a millisecond, an incident flux of 0.1 photons per second on
an effective detector area of 0.1 mm2--a sensitivity that exceeds previously
reported values by a factor of more than 10(4). The sensitivity is a consequence
of the unconventional detection mechanism, in which one absorbed photon leads to
a current of 10(6)-10(12) electrons through the quantum dot. By contrast,
mechanisms of conventional detectors or photon assisted tunnelling in single
electron transistors produce only a few electrons per incident photon.
PMID- 10667788
TI - Efficient organic photovoltaic diodes based on doped pentacene.
AB - Recent work on solar cells based on interpenetrating polymer networks and solid
state dye-sensitized devices shows that efficient solar-energy conversion is
possible using organic materials. Further, it has been demonstrated that the
performance of photovoltaic devices based on small molecules can be effectively
enhanced by doping the organic material with electron-accepting molecules. But as
inorganic solar cells show much higher efficiencies, well above 15 per cent, the
practical utility of organic-based cells will require their fabrication by lower
cost techniques, ideally on flexible substrates. Here we demonstrate efficiency
enhancement by molecular doping in Schottky-type photovoltaic diodes based on
pentacene--an organic semiconductor that has received much attention as a
promising material for organic thin-film transistors, but relatively little
attention for use in photovoltaic devices. The incorporation of the dopant
improves the internal quantum efficiency by more than five orders of magnitude
and yields an external energy conversion efficiency as high as 2.4 per cent for a
standard solar spectrum. Thin-film devices based on doped pentacene therefore
appear promising for the production of efficient 'plastic' solar cells.
PMID- 10667789
TI - Rainfall and drought in equatorial east Africa during the past 1,100 years.
AB - Knowledge of natural long-term rainfall variability is essential for water
resource and land-use management in sub-humid regions of the world. In tropical
Africa, data relevant to determining this variability are scarce because of the
lack of long instrumental climate records and the limited potential of standard
high-resolution proxy records such as tree rings and ice cores. Here we present a
decade-scale reconstruction of rainfall and drought in equatorial east Africa
over the past 1,100 years, based on lake-level and salinity fluctuations of Lake
Naivasha (Kenya) inferred from three different palaeolimnological proxies:
sediment stratigraphy and the species compositions of fossil diatom and midge
assemblages. Our data indicate that, over the past millennium, equatorial east
Africa has alternated between contrasting climate conditions, with significantly
drier climate than today during the 'Medieval Warm Period' (approximately AD 1000
1270) and a relatively wet climate during the 'Little Ice Age' (approximately AD
1270-1850) which was interrupted by three prolonged dry episodes. We also find
strong chronological links between the reconstructed history of natural long-term
rainfall variation and the pre-colonial cultural history of east Africa,
highlighting the importance of a detailed knowledge of natural long-term rainfall
fluctuations for sustainable socio-economic development.
PMID- 10667790
TI - Precise climate monitoring using complementary satellite data sets
AB - Observations from Earth-orbiting satellites have been a key component in
monitoring climate change for the past two decades. This has become possible with
the availability of air temperatures from the Microwave Sounding Unit (MSU) since
1979, sea surface temperatures from the Advanced Very High Resolution Radiometer
(AVHRR) since 1982 and, most recently, measurements of atmospheric water vapour
content from the Special Sensor Microwave Imager (SSM/I) since 1987. Here we
present a detailed comparison of each pair of these three time series, focusing
on both interannual and decadal variations in climate. We find a strong
association between sea surface temperature, lower-tropospheric air temperature
and total column water-vapour content over large oceanic regions on both time
scales. This lends observational support to the idea of a constant relative
humidity model having a moist adiabatic lapse rate. On the decadal timescale, the
combination of data sets shows a consistent warming and moistening trend of the
marine atmosphere for 1987-1998.
PMID- 10667791
TI - The Pleistocene serpent Wonambi and the early evolution of snakes.
AB - The Madtsoiidae were medium sized to gigantic snakes with a fossil record
extending from the mid-Cretaceous to the Pleistocene, and spanning Europe,
Africa, Madagascar, South America and Australia. This widely distributed group
survived for about 90 million years (70% of known ophidian history), and
potentially provides important insights into the origin and early evolution of
snakes. However, madtsoiids are known mostly from their vertebrae, and their
skull morphology and phylogenetic affinities have been enigmatic. Here we report
new Australian material of Wonambi, one of the last-surviving madtsoiids, that
allows the first detailed assessment of madtsoiid cranial anatomy and
relationships. Despite its recent age, which could have overlapped with human
history in Australia, Wonambi is one of the most primitive snakes known--as basal
as the Cretaceous forms Pachyrhachis and Dinilysia. None of these three primitive
snake lineages shows features associated with burrowing, nor do any of the
nearest lizard relatives of snakes (varanoids). These phylogenetic conclusions
contradict the widely held 'subterranean' theory of snake origins, and instead
imply that burrowing snakes (scolecophidians and anilioids) acquired their
fossorial adaptations after the evolution of the snake body form and jaw
apparatus in a large aquatic or (surface-active) terrestrial ancestor.
PMID- 10667792
TI - Stimulation by ammonium-based fertilizers of methane oxidation in soil around
rice roots.
AB - Methane is involved in a number of chemical and physical processes in the Earth's
atmosphere, including global warming. Atmospheric methane originates mainly from
biogenic sources, such as rice paddies and natural wetlands; the former account
for at least 30% of the global annual emission of methane to the atmosphere. As
an increase of rice production by 60% is the most appropriate way to sustain the
estimated increase of the human population during the next three decades,
intensified global fertilizer application will be necessary: but it is known that
an increase of the commonly used ammonium-based fertilizers can enhance methane
emission from rice agriculture. Approximately 10-30% of the methane produced by
methanogens in rice paddies is consumed by methane-oxidizing bacteria associated
with the roots of rice; these bacteria are generally thought to be inhibited by
ammonium-based fertilizers, as was demonstrated for soils and sediments. In
contrast, we show here that the activity and growth of such bacteria in the root
zone of rice plants are stimulated after fertilization. Using a combination of
radioactive fingerprinting and molecular biology techniques, we identify the
bacteria responsible for this effect. We expect that our results will make
necessary a re-evaluation of the link between fertilizer use and methane
emissions, with effects on global warming studies.
PMID- 10667793
TI - Activin- and Nodal-related factors control antero-posterior patterning of the
zebrafish embryo.
AB - Definition of cell fates along the dorso-ventral axis depends on an antagonistic
relationship between ventralizing transforming growth factor-beta superfamily
members, the bone morphogenetic proteins and factors secreted from the dorsal
organizer, such as Noggin and Chordin. The extracellular binding of the last
group to the bone morphogenetic proteins prevents them from activating their
receptors, and the relative ventralizer:antagonist ratio is thought to specify
different dorso-ventral cell fates. Here, by taking advantage of a non-genetic
interference method using a specific competitive inhibitor, the Lefty-related
gene product Antivin, we provide evidence that cell fate along the antero
posterior axis of the zebrafish embryo is controlled by the morphogenetic
activity of another transforming growth factor-beta superfamily subgroup--the
Activin and Nodal-related factors. Increasing antivin doses progressively deleted
posterior fates within the ectoderm, eventually resulting in the removal of all
fates except forebrain and eyes. In contrast, overexpression of activin or nodal
related factors converted ectoderm that was fated to be forebrain into more
posterior ectodermal or mesendodermal fates. We propose that modulation of
intercellular signalling by Antivin/Activin and Nodal-related factors provides a
mechanism for the graded establishment of cell fates along the antero-posterior
axis of the zebrafish embryo.
PMID- 10667794
TI - Separable processing of consonants and vowels.
AB - There are two views about the nature of consonants and vowels. One view holds
that they are categorically distinct objects that play a fundamental role in the
construction of syllables in speech production. The other view is that they are
convenient labels for distinguishing between peak (vowel) and non-peak
(consonant) parts of a continuous stream of sound that varies in sonority
(roughly the degree of openness of the vocal apparatus during speech), or that
they are summary labels for bundles of feature segments. Taking the latter view,
consonants and vowels do not have an independent status in language processing.
Here we provide evidence for the possible categorical distinction between
consonants and vowels in the brain. We report the performance of two Italian
speaking aphasics who show contrasting, selective difficulties in producing
vowels and consonants. Their performance in producing individual consonants is
independent of the sonority value and feature properties of the consonants. This
pattern of results suggests that consonants and vowels are processed by distinct
neural mechanisms, thereby providing evidence for their independent status in
language production.
PMID- 10667795
TI - Noradrenaline in the ventral forebrain is critical for opiate withdrawal-induced
aversion.
AB - Cessation of drug use in chronic opiate abusers produces a severe withdrawal
syndrome that is highly aversive, and avoidance of withdrawal or associated
stimuli is a major factor contributing to opiate abuse. Increased noradrenaline
in the brain has long been implicated in opiate withdrawal, but it has not been
clear which noradrenergic systems are involved. Here we show that microinjection
of beta-noradrenergic-receptor antagonists, or of an alpha2-receptor agonist,
into the bed nucleus of the stria terminalis (BNST) in rats markedly attenuates
opiate-withdrawal-induced conditioned place aversion. Immunohistochemical studies
revealed that numerous BNST-projecting cells in the A1 and A2 noradrenergic cell
groups of the caudal medulla were activated during withdrawal. Lesion of these
ascending medullary projections also greatly reduced opiate-withdrawal-induced
place aversion, whereas lesion of locus coeruleus noradrenergic projections had
no effect on opiate-withdrawal behaviour. We conclude that noradrenergic inputs
to the BNST from the caudal medulla are critically involved in the aversiveness
of opiate withdrawal.
PMID- 10667796
TI - Nogo-A is a myelin-associated neurite outgrowth inhibitor and an antigen for
monoclonal antibody IN-1.
AB - The capacity of the adult brain and spinal cord to repair lesions by axonal
regeneration or compensatory fibre growth is extremely limited. A monoclonal
antibody (IN-1) raised against NI-220/250, a myelin protein that is a potent
inhibitor of neurite growth, promoted axonal regeneration and compensatory
plasticity following lesions of the central nervous system (CNS) in adult rats.
Here we report the cloning of nogo A, the rat complementary DNA encoding NI
220/250. The nogo gene encodes at least three major protein products (Nogo-A, -B
and -C). Recombinant Nogo-A is recognized by monoclonal antibody IN-1, and it
inhibits neurite outgrowth from dorsal root ganglia and spreading of 3T3
fibroblasts in an IN-1-sensitive manner. Antibodies against Nogo-A stain CNS
myelin and oligodendrocytes and allow dorsal root ganglion neurites to grow on
CNS myelin and into optic nerve explants. These data show that Nogo-A is a potent
inhibitor of neurite growth and an IN-1 antigen produced by oligodendrocytes, and
may allow the generation of new reagents to enhance CNS regeneration and
plasticity.
PMID- 10667797
TI - Identification of the Nogo inhibitor of axon regeneration as a Reticulon protein.
AB - Adult mammalian axon regeneration is generally successful in the peripheral
nervous system (PNS) but is dismally poor in the central nervous system (CNS).
However, many classes of CNS axons can extend for long distances in peripheral
nerve grafts. A comparison of myelin from the CNS and the PNS has revealed that
CNS white matter is selectively inhibitory for axonal outgrowth. Several
components of CNS white matter, NI35, NI250(Nogo) and MAG, that have inhibitory
activity for axon extension have been described. The IN-1 antibody, which
recognizes NI35 and NI250(Nogo), allows moderate degrees of axonal regeneration
and functional recovery after spinal cord injury. Here we identify Nogo as a
member of the Reticulon family, Reticulon 4-A. Nogo is expressed by
oligodendrocytes but not by Schwann cells, and associates primarily with the
endoplasmic reticulum. A 66-residue lumenal/extracellular domain inhibits axonal
extension and collapses dorsal root ganglion growth cones. In contrast to Nogo,
Reticulon 1 and 3 are not expressed by oligodendrocytes, and the 66-residue
lumenal/extracellular domains from Reticulon 1, 2 and 3 do not inhibit axonal
regeneration. These data provide a molecular basis to assess the contribution of
Nogo to the failure of axonal regeneration in the adult CNS.
PMID- 10667798
TI - Torque-generating units of the flagellar motor of Escherichia coli have a high
duty ratio.
AB - Rotation of the bacterial flagellar motor is driven by an ensemble of torque
generating units containing the proteins MotA and MotB. Here, by inducing
expression of MotA in motA- cells under conditions of low viscous load, we show
that the limiting speed of the motor is independent of the number of units: at
vanishing load, one unit turns the motor as rapidly as many. This result
indicates that each unit may remain attached to the rotor for most of its
mechanochemical cycle, that is, that it has a high duty ratio. Thus, torque
generators behave more like kinesin, the protein that moves vesicles along
microtubules, than myosin, the protein that powers muscle. However, their
translation rates, stepping frequencies and power outputs are much higher, being
greater than 30 microm s(-1), 12 kHz and 1.5 x 10(5) pN nm s(-1), respectively.
PMID- 10667799
TI - The DExH protein NPH-II is a processive and directional motor for unwinding RNA.
AB - All aspects of cellular RNA metabolism and processing involve DExH/D proteins,
which are a family of enzymes that unwind or manipulate RNA in an ATP-dependent
fashion. DExH/D proteins are also essential for the replication of many viruses,
and therefore provide targets for the development of therapeutics. All DExH/D
proteins characterized to date hydrolyse nucleoside triphosphates and, in most
cases, this activity is stimulated by the addition of RNA or DNA. Several members
of the family unwind RNA duplexes in an NTP-dependent fashion in vitro; therefore
it has been proposed that DExH/D proteins couple NTP hydrolysis to RNA
conformational change in complex macromolecular assemblies. Despite the central
role of DExH/D proteins, their mechanism of RNA helicase activity remains
unknown. Here we show that the DExH protein NPH-II unwinds RNA duplexes in a
processive, unidirectional fashion with a step size of roughly one-half helix
turn. We show that there is a quantitative connection between ATP utilization and
helicase processivity, thereby providing direct evidence that DExH/D proteins can
function as molecular motors on RNA.
PMID- 10667800
TI - DNA-bound structures and mutants reveal abasic DNA binding by APE1 and DNA repair
coordination [corrected].
AB - Non-coding apurinic/apyrimidinic (AP) sites in DNA are continually created in
cells both spontaneously and by damage-specific DNA glycosylases. The
biologically critical human base excision repair enzyme APE1 cleaves the DNA
sugar-phosphate backbone at a position 5' of AP sites to prime DNA repair
synthesis. Here we report three co-crystal structures of human APE1 bound to
abasic DNA which show that APE1 uses a rigid, pre-formed, positively charged
surface to kink the DNA helix and engulf the AP-DNA strand. APE1 inserts loops
into both the DNA major and minor grooves and binds a flipped-out AP site in a
pocket that excludes DNA bases and racemized beta-anomer AP sites. Both the APE1
active-site geometry and a complex with cleaved AP-DNA and Mn2+ support a
testable structure-based catalytic mechanism. Alanine substitutions of the
residues that penetrate the DNA helix unexpectedly show that human APE1 is
structurally optimized to retain the cleaved DNA product. These structural and
mutational results show how APE1 probably displaces bound glycosylases and
retains the nicked DNA product, suggesting that APE1 acts in vivo to coordinate
the orderly transfer of unstable DNA damage intermediates between the excision
and synthesis steps of DNA repair.
PMID- 10667801
TI - Design of single-layer beta-sheets without a hydrophobic core.
AB - The hydrophobic effect is the main thermodynamic driving force in the folding of
water-soluble proteins. Exclusion of nonpolar moieties from aqueous solvent
results in the formation of a hydrophobic core in a protein, which has been
generally considered essential for specifying and stabilizing the folded
structures of proteins. Outer surface protein A (OspA) from Borrelia burgdorferi
contains a three-stranded beta-sheet segment which connects two globular domains.
Although this single-layer beta-sheet segment is exposed to solvent on both faces
and thus does not contain a hydrophobic core, the segment has a high
conformational stability. Here we report the engineering of OspA variants that
contain larger single-layer beta-sheets (comprising five and seven beta-strands)
by duplicating a beta-hairpin unit within the beta-sheet. Nuclear magnetic
resonance and small-angle X-ray scattering analyses reveal that these extended
single-layer beta-sheets are formed as designed, and amide hydrogen-deuterium
exchange and chemical denaturation show that they are stable. Thus, interactions
within the beta-hairpin unit and those between adjacent units, which do not
involve the formation of a hydrophobic core, are sufficient to specify and
stabilize the single-layer beta-sheet structure. Our results provide an expanded
view of protein folding, misfolding and design.
PMID- 10667802
TI - Bioengineering programmes rise to meet the challenge of a young science.
PMID- 10667803
TI - Exploring the territory in tissue engineering.
PMID- 10667804
TI - Progress from a fragile start.
PMID- 10667805
TI - The immunobiology of transplantation.
AB - Having recently published A History of Transplantation Immunology, I have become
acutely aware of the great revolution that has taken place in the field of organ
transplantation - not only in terms of our understanding of the immunobiological
mechanisms underlying the rejection process and the various means of prolonging
graft survival, but also in clinical terms. Only 50 years ago, clinical kidney
allo-transplantation (and it was the kidney that spearheaded clinical advances)
was a highly experimental and dangerous procedure dependent on whole-body
irradiation and the results were often intensely disappointing. Now, the
transplantation of kidneys is almost routine, results are excellent and the
lessons learnt about immunosuppression and patient management have been applied
with great success to a large number of other organs (see below).
PMID- 10667806
TI - Immunobiology of solid organ transplantation.
AB - The field of organ transplantation is entering a very exciting phase in which
tolerance induction may become a therapeutic possibility. The induction of
tolerance would allow patients to enjoy the benefits of their transplanted organ
without risking the mortality and morbidity associated with long-term
pharmacological immunosuppression. In this review, we explore the immunobiology
of solid organ transplantation, discussing the immunological mechanisms
responsible for allograft rejection, and outlining the rational behind a range of
successful experimental tolerance induction strategies.
PMID- 10667807
TI - Renal transplantation: origins and future.
AB - Renal transplantation from its first successful operation in 1954 has become the
preferred treatment option of patients with renal failure. The success of this
recent development is followed in this article which tabulates surgical, tissue
typing and immunosuppressive advancement. This success has produced other
problems notably chronic rejection, posttransplant lympho-proliferative disease
and donor shortage. The solutions to these problems are discussed, together with
a hint of what is to come in the future.
PMID- 10667808
TI - Present status and future prospects in liver transplantation.
AB - Results of liver transplantation (LTx) have largely improved over the last few
years and a one year patient survival rate of around 90% for elective transplants
can now be reached. This is mostly the consequence of better patient selection
and preparation, improved surgical techniques, improved intra- and postoperative
care, reduced incidence of primary non function (< or =5%) and hepatic artery
thrombosis (< or =5%), the understanding that the liver induces a tolerogenic
response and the development of more judicious immunosuppressive protocols.
Because patient and graft survival have dramatically improved, other problems
become more overt and need to be addressed: side effects of long-term exposure to
immunosuppression, recurrent disease, development of biliary strictures. LTx for
acute liver failure continues to bring special difficulties. Strategies need to
be urgently developed to augment the number of donor grafts and to combat the
profound organ shortage - currently the only limiting factor to wider application
of LTx.
PMID- 10667809
TI - Pancreatic transplantation: a review.
AB - Pancreatic transplantation recently became a routine treatment for Type I
diabetic patients with uremia or for those who previously received a kidney
transplant with 1 year graft and patient survival of over 80% and 90%,
respectively. Despite the life-long need for immunosuppression, this is clearly
acceptable when compared to the need for dialysis and insulin therapy, and it
reduces the evolution of diabetic complications. Isolated pancreatic transplant
is less commonly applied because of the need for immunosuppression and the high
rate of complications. However, this can still be an acceptable option for
individual patients with brittle diabetes and hypoglycemic unawareness. Despite
the fact that pancreas transplantation is an effective treatment for selected
Type I diabetics, it remains a difficult surgical procedure with many potential
complications and with several issues still subject to debate. In this article,
the authors describe the procedure in all of its aspects and variations, and
offer, through a review of the recent literature, insights on the current status
of this transplant
PMID- 10667810
TI - Small bowel transplantation.
AB - Many patients die each year lacking only a functional small bowel to survive. The
minimum amount of small intestinal absorptive surface required to sustain life
varies from patient to patient. Prolonged survival with oral alimentation alone
has been reported in a few patients with an intact duodenum and as little as 15
45 cm of residual jejunum. However, without long-term total parenteral nutrition
(TPN), prolonged patient survival is the exception rather than the rule. Chronic
parenteral nutrition is associated with complications, including sepsis, venous
thrombosis, metabolic disorders and liver dysfunction. From studies of patients
currently on long-term TPN, it would appear that there are between two and three
patients per million of population per year who develop irreversible small bowel
failure. It is estimated that 20 new patients/year in the UK receiving home TPN
would be potential candidates for small bowel transplantation.
PMID- 10667811
TI - Surgical procedures for primary, metastatic or adjacent parotid tumours.
AB - OBJECTIVE: The retrospective analysis of the surgical procedures in primary
parotid and metastatic or adjacent parotid tumors. PATIENTS AND METHODS:
Retrospective review of the records of 145 patients operated on for primary,
metastatic or adjacent parotid tumors revealed 85 patients with benign tumors, 24
with primary malignant tumors, 19 with squamous skin carcinomas, 12 with skin
melanomas, 3 with basocellular carcinomas and 2 with sarcomas of the parotid
region. The analysis included the type of parotidectomy, the need for facial
nerve sacrifice (FNS), type of neck dissection and soft part reconstruction.
RESULTS: Superficial parotidectomy was performed in 81% of the benign parotid
tumors and 100% of skin melanomas. Total parotidectomy was frequent in malignant
parotid tumors (62%), epidermoid skin tumors (64%) and in basocellular/sarcomas
of the parotid region (80%). Skin graft or flaps was infrequent in primary
malignant tumors (12.5%), and frequent in epidermoid skin tumors (74%), melanomas
(58%) and basocellular/sarcomas (100%). FNS was necessary in primary malignant
(25%), adjacent epidermoid (37%), melanomas (17%) and basocellular/sarcomas
(80%). Details on neck dissections are provided. CONCLUSIONS: Superficial
parotidectomy was an adequate procedure for most benign parotid tumors and for
melanoma patients. In primary malignant and adjacent or metastatic skin tumors,
total parotidectomy, neck dissection and soft part reconstruction were frequent
procedures. FNS and soft part reconstruction should be anticipated more
frequently in squamous/basocellular skin tumors or sarcomas adjacent to the
parotid gland.
PMID- 10667812
TI - Surgical repair of pectus carinatum.
AB - Pectus carinatum represents a variety of protrusion deformities of the anterior
chest wall. Although various non-operative methods of treatment have been
employed, surgery has been widely accepted as the only effective method for the
correction of pectus carinatum. We evaluate our 14 year single center experience
of pectus carinatum correction on 111 patients using a uniform technique of
internal stabilization employing stainless steel struts. Operative correction
required double bilateral chondrotomy parasternally and at points of transition
to normal ribs, followed by detorsion of the sternum, retrosternal mobilization
and correction of the everted sternum as well as of the everted and inverted
ribs. The mobilized sternum after incomplete wedge osteotomy was finally
stabilized by one transternal and two bilateral parasternal metal struts. The
corrections were completed with successful repair in 109 patients (98.2%). Major
recurrences in 2 patients (1.8%) were corrected while mild recurrence were
observed in 3 patients (2.7%).
PMID- 10667813
TI - Significant prognostic factors in patients with node-negative gastric cancer.
AB - BACKGROUND: We evaluated the influence of several clinicopathological variables
on 5 year survival of patients with node-negative gastric cancer. PATIENTS AND
METHODS: Clinical characteristics were retrieved from the records of all patients
who underwent gastric resection between 1985 and 1995 at the Department of
General Surgery, Sendai National Hospital, and follow-up data were obtained from
our tumor registry. Pathological characteristics were determined from a detailed
review of all available histopathological slides. The results of a retrospective
analysis of clinicopathological data of 339 patients having no lymph node
metastasis were compared with those of 358 patients with lymph node metastasis.
Univariate and multivariate analyses of patients with node-negative gastric
cancer were performed to evaluate the prognostic significance of
clinicopathological features (age, gender, gross type, histological type, depth
of invasion and location). RESULTS: The 5 year survival rate for patients with
node-negative gastric cancer was 92.5%. Node-negative gastric cancers were
characterized by a smaller tumor, expansive and medullary histological type, and
less frequency of lymphatic invasion and vascular permeation. In multivariate
analysis, the statistical significant prognostic factors were tumor size (P =
0.0185), vascular permeation (P = 0.0011) and cancer-stromal relationship (P =
0.0291). CONCLUSION: Tumor size, vascular microinvasion and cancer-stromal
relationship are the most reliable predictors of 5 year survival for patients
with node-negative gastric cancer.
PMID- 10667814
TI - Study of survival and prognostic factors in patients undergoing resection for
gastric linitis plastica: a review of 86 cases.
AB - A retrospective study was conducted in a series of 86 patients (51 men and 35
women; mean age 63.4 years) treated from 1979 to 1995 for linitis plastica of the
stomach (LP). The mean interval between the first manifestations and surgery was
3.5 months. The most frequent clinical sign was epigastric pain which occurred in
80.4% of cases. Biopsies were positive in 75.6% of cases. Typical features of LP
were found in only 46% of esogastric barium enemas and 11.8% of upper
gastrofiberscopic examinations. Seventy-four patients had surgical excision (51
total and 23 partial gastrectomies). There were 6 (7%) postoperative deaths and
10 (11.6%) surgical complications. Node involvement was found in 54 (72.9%)
patients. Overall actuarial survival (n = 86) was 50% at 12 months, 40% at 18
months and 7.5% at 84 months. Survival did not depend on the delay in diagnosis,
histological analysis of the extremities of the excised piece, associated tissue
differentiation, node involvement or the type of surgical excision. The prognosis
differed according to tumor height (P<0.01) and involvement of the deep stomach
wall (P<0.001). No independent prognostic factor was found in multivariate
analysis. Surgery remains the sole possibility for curative therapy in these
patients.
PMID- 10667815
TI - Gallbladder carcinoma during laparoscopic cholecystectomy: is it associated with
bad prognosis?
AB - Laparoscopic cholecystectomy is the treatment of choice for gallstone disease.
The ultrasonogram has failed for the early detection of gallbladder cancer,
especially if inflammation (chronic or acute) is present. Incidental gallbladder
could be an important cancer finding during laparoscopic cholecystectomy, due to
the potential cancer cell dissemination during the procedure. In our Department,
6500 laparoscopic cholecystectomies have been performed in the last 5 years and
in 15 cases (0.23%) gallbladder cancer was found during surgery or after
histological examination of the resected gallbladder. In none of these 15
patients was pre-operative diagnosis of gallbladder carcinoma postulated. When re
evaluation of the pre-operative ultrasonograms was done, it was possible to
observe signs suggesting the presence of neoplastic infiltration in 4 of them
(28.6%). During videoscopic exploration, also in 4 patients, the suspicion of
gallbladder cancer was noted. Laparoscopic cholecystectomy was completed in 9
patients. In 2 of them, in situ or mucosal invasion was demonstrated with a long
survival. One patient presented recurrence at the biliary hilum 2,5 years after
surgery. Six patients were re-operated and in 4 of them peritoneal or port site
metastasis was found; all died early (4.5 month median survival). The other 2
patients were submitted to liver bed resection and lymph node dissection. These
patients are free of cancer recurrence after 15 months of follow-up. Six patients
were converted to open surgery, performing palliative procedures and died before
the 12 month follow-up. The suspicion of pre-operative gallbladder cancer is
generally unlikely to be confirmed based on ultrasonographic signs; but, in some
cases with high suspicion, further investigation (TAC, tumor markers, etc.) must
be indicated in order to avoid poor results. Laparoscopic cholecystectomy could
be associated with bad prognosis, and then, when gallbladder cancer is suspected
during the laparoscopic procedure, conversion to open surgery could be the best
choice.
PMID- 10667816
TI - Prevention of postherniorrhaphy persistent pain: results of a prospective study.
AB - Anterior tension-free and laparoscopic inguinal herniorrhaphies represent one of
the most common surgical procedure. Postherniorrhaphy persistent pain due to
injures of inguinal regional nerves is rare, difficult to cure, often disabling
and involving malpractice litigation. In a prospective study, we evaluated the
effectiveness of neurectomy of the iliohypogastric nerve in prevention of
postoperative persistent pain after anterior tension free herniorrhaphy. Between
1992-1995, we performed 180 anterior herniorraphies in 151 male patients.
Iliohypogastric nerve was removed in all the herniorrhaphies. Polypropylene plug
and sutured mesh were employed. Postoperative pain and clinical relevance of hypo
anesthesia and paresthesia were assessed. No patient complained of postoperative
persistent pain. Hypo-anesthesia, never considered incapacitating, was present in
1% of patients after 2 years. We consider neurectomy of the iliohypogastric nerve
a potentially useful surgical step in preventing postoperative persistent pain
after anterior tension-free herniorrhaphy.
PMID- 10667817
TI - Invasive and non-invasive physiological monitoring of blunt trauma patients in
the early period after emergency admission.
AB - Pulmonary artery catheterization is usually not available to critically injured
patients before admission to the intensive care unit, where action to correct
values derived from such monitoring may be too late. Methods allowing hemodynamic
monitoring during the early stages after trauma need to be explored. We used non
invasive monitoring systems (bioimpedance cardiac output monitoring, pulse
oximetry and transcutaneous oximetry) to evaluate early temporal hemodynamic
patterns after blunt trauma, and compared these to invasive PA monitoring. We
included prospectively 134 patients monitored shortly after admission to the
emergency department. The non-invasive impedance cardiac output estimations under
extenuating emergency conditions approximated those of the thermodilution method:
r = 0.83, r2 = 0.69, P<0.001; bias and precision were -0.02+/-0.78 l/min/m2. In
the intensive care unit, these values improved further to: r = 0.91, r2 = 0.83,
P<0.001; bias and precision = 0.36+/-0.59 l/min/m2. Monitoring revealed episodes
of hypotension, low cardiac index, arterial hemoglobin desaturation, low
transcutaneous oxygen and high transcutaneous carbon dioxide tensions, and low
oxygen consumption during initial resuscitation. Low flow and poor tissue
perfusion were more pronounced in non-survivors by both methods. Multicomponent
non-invasive monitoring systems give continuous on-line, real-time displays of
physiological data that allow early recognition of circulatory dysfunction. Such
systems provide information similar to that provided by the invasive
thermodilution method, and are easier and safer to use.
PMID- 10667818
TI - Intrapericardial tumbling bullet.
AB - Foreign bodies of the pericardium are rare and they are associated most commonly
with significant trauma. The diagnosis of a pericardial foreign body can be
difficult. One must distinguish between foreign matter in the cardiac chamber or
free-floating in the mediastinum. Serial chest X-rays and fluoroscopy were most
helpful to us. Neither CT scan nor an echocardiogram were particularly helpful.
To prevent pericarditis, either sterile or non-sterile, with potential for other
significant complications, removal of a pericardial foreign body is always
indicated.
PMID- 10667819
TI - Histopathological findings in experimental aneurysms embolized with conventional
and thrombogenic/antithrombolytic Guglielmi coils.
AB - We studied the short- and long-term histological responses induced by
conventional and modified electronically detachable coils (GDCs) in experimental
aneurysms. Eighteen carotid bifurcation aneurysms were produced microsurgically
in rabbits. Six animals each were treated either with conventional or with GDCs
coated with a mixture of tissue-thromboplastin to enhance intra-aneurysmal
thrombus formation and of plasminogen activator inhibitor type-1 (PAI-1) in
inhibit intra-aneurysmal clot fibrinolysis. Six served as untreated controls.
Follow-up angiograms were obtained immediately and at 3, 6, 9, 12, 17, and 24
weeks after embolization prior to sacrifice of the animals. All aneurysms were
studied macroscopically and histopathologically with the coils in situ. Five of
six control aneurysms remained patent. Endovascular occlusion rates between > 90%
and 100% were achieved in nine of twelve coiled aneurysms. Follow-up angiography
demonstrated recanalization and coil compaction in 5 of them. Gross and
microscopic histopathological examination revealed a membrane covering the
orifice, intra-aneurysmal scar formation, and development of a neo-intima in both
treatment groups at 17 and 24 weeks postembolization. The granulation tissue
response appeared to be equally distributed in aneurysms treated with either
uncoated or coated coils. Further quantitative morphometric studies are needed to
prove if a thrombogenic/antithrombolytic coil-coating might be of value in
providing a more enduring anatomic result after GDC-treatment of human brain
aneurysms.
PMID- 10667820
TI - Postoperative headache after the lateral suboccipital approach: craniotomy versus
craniectomy.
AB - The lateral suboccipital approach to the cerebellopontine angle is typically
performed as a small craniectomy. Incisional pain and headache following
cerebellopontine angle surgery have been reported. Adherence of the cervical
muscles to the dura, which is richly innervated, with consequent traction has
been suggested to be responsible for postoperative headache. Therefore,
postoperative headache probably could be reduced by replacing the bone flap
between the muscles and the dura. In a prospective non-randomized study this
hypothesis was tested by comparing craniectomy and craniotomy. 40 patients
underwent removal of an acoustic neuroma via the retrosigmoid approach. Patients
with a history of migraine, with additional intracerebral tumors or recurrencies
as well as patients who developed a CSF fistula postoperatively were excluded. 29
patients were eligible for further evaluation. 13 patients underwent a
craniotomy, 16 patients a craniectomy. All patients were subject to a
standardized telephone interview three months and one year after surgery.
Comparing the craniotomy group to the craniectomy group no difference was
observed regarding age, sex, tumor size and duration of operation. 3 months as
well as 12 months postoperatively headache was significantly (p < 0.05) less
frequent in the craniotomy group as compared to the craniectomy group. In
conclusion, an osteoplastic craniotomy significantly reduces postoperative
headache and is therefore highly recommended.
PMID- 10667821
TI - A new technique for attaching a stereotactic frame to the head: technical note.
AB - The aim of this study was to develop a device which allows an intermediate,
painless fixation of a stereotactic frame prior to definite pin fixation. To
stabilize the stereotactic frame rubber coated metal springs were used. By
testing the springs on 30 volunteers with different head diameters and
circumferences the optimal shape was determined. In the clinical setting 15
patients undergoing stereotactic surgery were tested, stability and patient's
convenience were measured. The procedure was well tolerated and measurements
revealed symmetric distances between head and frame. Therefore these metal
springs are a useful accessory to the Leksell stereotactic system.
PMID- 10667822
TI - Surgical management for supratentorial astrocytic tumors.
AB - To compare the surgical treatment of supratentorial astrocytic tumors, various
methods were performed by the same surgeon. Removal of the tumor was performed
using stereotactic open surgery, the fluorescein surgical microscope, and a
frameless stereotactic system, and these methods were compared. The method using
the stereotactic technique was useful because there was no disturbance by the
shifting of the brain during the operation. However, its limitation was that only
points can be marked. The fluorescein surgical microscope was very useful in the
cases where neuroradiological images were enhanced by the contrast medium, but
deep lesions could not be identified from the brain surface. This method could
not be used, either, in the case of images that were not enhanced. By the method
using the frameless stereotactic system, identification of tumors including deep
lesions was possible from every direction, but the problems were the mobility of
the registered skin and the shifting of the brain during the operation. On the
basis of these results, the combined method of the fluorescein surgical
microscope and the frameless stereotactic system appeared to be useful when
neuroradiological images of lesions were enhanced because these methods were
complementary towards each other, and the frameless stereotactic system
supplemented by the stereotactic open surgery technique (such as leaving a marker
in deep lesions just before the start of microsurgery) seemed useful when images
could not be enhanced.
PMID- 10667823
TI - Frameless neuronavigation applied to endoscopic neurosurgery.
AB - OBJECTIVE: We retrospectively analyzed the indications, surgical techniques, and
applicability of frameless neuronavigation to endoscopic procedures in a
heterogeneous group of 15 patients. MATERIAL AND METHODS: In 8 patients
indications for surgery were cystic lesions, in 3 patients intraventricular
tumors, and in 4 patients occlusive hydrocephalus. The mean age was 39 years
(range 9-76 years). The follow-up period ranged from 5-24 months (mean 10
months). Frameless neuronavigation was accomplished with the "operating arm
system" in 10 cases and with the "optical tracking system" in 5 cases (RADIONICS,
Burlington, USA). RESULTS: In all 15 cases, neuronavigation sufficiently provided
anatomical orientation, preoperative planning, and intraoperative realization of
the approach. The calculated mean calibration error was 2.1 mm. There have been
no permanent morbidities and no mortalities related to the use of endoscopes and
neuronavigation. CONCLUSION: In endoscopic neurosurgery, frameless
neuronavigation is a useful tool in planning and realizing the approach and
improving intraoperative orientation in selected cases. Indications are small or
hidden lesions, impaired visual conditions, abnormal anatomy, and narrow
ventricles. Endoscopic procedures include fenestration and resection of
intraventricular or intraparenchymal cysts, biopsy of intraventricular tumors,
and third ventriculostomy in selected cases.
PMID- 10667824
TI - Optimized visualization of contrast medium dependent differences in CT/MRI scans
by RGB transformation.
AB - OBJECTIVE: In order to be able to assess the contrast medium enhancement of
vessels and regions with disturbed blood-brain barrier, the neurosurgeon must
mentally perform a subtraction of the corresponding native and contrast-enhanced
scans of the CT or MRI. The principle disadvantages of this comparison are the
amount of time required and the potential errors which may result from false
interpretation. METHODS: The process presented here combines corresponding scans
without and with contrast medium offline on a PC. In this process each couple of
the black and white scans is assigned to the colour channels of the RGB system
(red, green, blue) and transformed to one colour picture of the RGB colour space
(additive colour mixture). RESULTS: We demonstrate that contrast medium-dependent
changes can be represented in a colour contrast of complementary colours in one
single picture. Additionally, the unchanged structures remain in the black and
white contrast as they were before. CONCLUSION: Thanks to the optimized
visualization of contrast medium dependent differences there are besides saving
in time further advantages such as the reduced amount of pictures and an
objective representation.
PMID- 10667825
TI - Endoscopic third ventriculostomy: a study of intracranial pressure vs.
haemodynamic changes.
AB - Fourteen paediatric patients with obstructive hydrocephalus were studied. They
underwent endoscopic third ventriculostomy under general anaesthesia. Their ages
ranged from 1 to 144 weeks (mean 34+/-36 weeks) and weight from 2 to 22 kg (mean
10.2+/-5.4 kg). In an attempt to identify the possible mechanisms of the
intraoperative haemodynamic changes associated with endoscopic third
ventriculostomy, we studied the intracranial pressure measured in the third
ventricle versus the haemodynamic changes. The intracranial pressure was measured
using a pressure transducer attached at one end to the endoscope and the other
end to the monitor. The mean third ventricle pressure value was 10.2 mmHg (+/
3.5). Bradycardia occurred in six (43%) of our patients. The mean value of the
lowest heart rate reading intraoperatively was 81 beats/min (+/-31.8). Negative
correlation was obtained between the intracranial pressure and the haemodynamic
changes. Alerting the surgeon to perforate the floor of the third ventricle or
withdraw the scope away from it was sufficient to resolve the bradycardia. We
concluded that serious dysrhythmias might occur during endoscopic third
ventriculostomy, the majority of which can be resolved without medications.
PMID- 10667826
TI - The tanycytic ependymoma of the lateral ventricle: case report.
AB - The tanycytic ependymoma is an extremely rare, primitive neuroectodermal tumor,
arising from the ependymoglial cells or tanycytes. Such cells are generally seen
in the primitive nervous system instead of the mature ependymal cells. The
tanycytic ependymoma described in this report was found in a 42-year-old man.
Histological analysis strongly suggested that this tumor originated from a
primitive progenitor cell, the ependymoglia or the tanycyte in the lateral
ventricle.
PMID- 10667827
TI - Pituitary abscess secondary to isolated sphenoid sinusitis.
AB - Intracranial complications from isolated sphenoid sinusitis are rare but
nevertheless demonstrate both a high morbidity and mortality. We herein report a
case of a pituitary abscess secondary to sphenoid sinusitis in a 12-year-old boy.
This patient presented with an acute onset of moderate fever and headache,
followed by progressive right ptosis. An emergency endoscopic endonasal
sphenoidotomy with sinus drainage and postoperative antibiotic therapy resulted
in a satisfactory recovery.
PMID- 10667828
TI - Orbital foreign bodies after penetrating gunshot wounds: retrospective analysis
of 22 cases and clinical review.
AB - We conducted a retrospective analysis of 22 patients having orbital penetrating
gunshot wounds treated over a 4-years period. The neurological status and the
site of injury for each patient are evaluated in this study. We propose a
practical protocol in the management of these orbital foreign bodies. Surgical
treatment was performed in 4 patients (had functional deficit) with medial
orbitotomy in 2, lateral orbitotomy in 1, and superior orbitotomy in 1. 3 of them
are improved, in one case the blindness has been continued. 18 patients were
treated conservatively and all of them are improved. All patients were followed
up for 2 years with cranial X-rays and CT scans. Neurological sequelae were
regressed which existed before the surgery. In conservatively treated cases,
infection, migration and functional deficit were not seen. In conclusion, orbital
penetrating gunshot wounds must be evaluated precisely by the surgeon and this
evaluation sets the guidelines for management. The operation should be reserved
for the patients in whom the necrotic soft tissues or orbital damages restrict
ocular movements.
PMID- 10667829
TI - Comparison of a new automatically controlled electrocoagulator (Valleylab NS 2000
INSTANT RESPONSE technology) with a high-frequency coagulator.
AB - Bipolar electrocoagulation is one of the most important procedures in modern
neurosurgery. However, there are still many practical problems, especially tissue
adherence to the tips of the coagulating forceps and the difficulty removing
carbonized clots from the tips. Both make the process less accurate and more time
consuming. To prevent formation of coagulum, recently, irrigation with a saline
solution and coating of the forceps tips with a special metal have been tried. In
this work, we compare a new bipolar electrocoagulator with automatic output
control in relation to tissue impedance (Auto Suture - Valleylab NS 2000 with
INSTANT RESPONSE technology) with a high-frequency coagulator (Erbotom ICC 350,
Erbe). The femoral arteries and nerves of Wistar rats, weighing on average 360 g,
were prepared and coagulation was carried out with variable power settings during
a constant time (3 seconds). Sections were stained with haematoxylin-eosin, van
Gieson and Luxol-Fast-Blue for histological examination. Coagulation with Erbotom
ICC 350 resulted in tissue sticking to the tips of the forceps in all cases,
regardless of the power chosen. With the new electrocoagulator, tissue adherence
to the forceps tips was not seen. With the new system, effective coagulation was
also achieved at comparably lower power settings.
PMID- 10667830
TI - Problems and perspectives of phenotyping for drug-metabolizing enzymes in man.
AB - Pronounced interindividual differences in drug disposition are mainly caused by
differences in the activity of liver drug-metabolizing enzymes. These depend on
known and unknown covariates, including genetic as well as environmental factors.
Phenotyping, i.e. assessment of enzyme activities in vivo after administration of
a test dose, seems to be a promising tool for determining actual metabolic
capacities. Although it is a well-established experimental approach, phenotyping
has not yet found its way into clinical practice. Main reasons for this are lack
of validation for many probes and assays used, complicated procedures,
invasiveness, semi-quantitative test results, non-compliance on behalf of the
subjects tested, high costs, and lack of prospective clinical studies to assess
the benefit of phenotyping for patients. Problems and perspectives of phenotyping
are exemplified for the cytochrome P-450 enzymes CYP1A2 and CYP3A4, two major
human drug-metabolizing enzymes.
PMID- 10667831
TI - Decreased oral bioavailability of loxoprofen at second administration in human
subjects.
AB - The objective of this study was to determine the extent of period effect on the
pharmacokineitcs of loxoprofen during consecutive dosing. Loxipen and Loxonin
tablets were administered to 16 healthy Korean male subjects at a single dose of
60 mg as loxoprofen sodium anhydrous in a 2 x 2 crossover investigation with a
two-week wash-out phase. Concentrations of loxoprofen in plasma were measured by
HPLC method for 6 h. The two formulations were found bioequivalent, but analysis
of variance (ANOVA) indicated that there was a significant (p < 0.05) period
effect in AUCinf (area under the plasma concentration-time curve from time zero
to infinity) between the administrations. A 20% decrease in the AUC was seen at
the second administration. This period effect on pharmacokinetics of loxoprofen
may be relevant for the patients who need consecutive administration of the drug.
PMID- 10667832
TI - Evaluation of the efficacy and dose-response relationship of dexibuprofen (S(+)
ibuprofen) in patients with osteoarthritis of the hip and comparison with racemic
ibuprofen using the WOMAC osteoarthritis index.
AB - OBJECTIVE: Treatment with non-steroidal anti-inflammatory drugs is the most
common pharmacological therapy of rheumatic diseases. For the symptomatic
treatment of painful disorders a dose-response relationship of the NSAID should
be a basic requirement, which is difficult to be proven in studies because
rheumatic diseases are heterogenous in terms of clinical involvement. The aim of
this double-blind randomized trial was to compare the isolated active enantiomer
dexibuprofen (S(+)-ibuprofen) with the double dose of racemic ibuprofen and to
show a dose-response relationship of dexibuprofen in painful osteoarthritis of
the hip. METHODS: 178 patients were randomly assigned to dexibuprofen 600/1,200
mg or racemic ibuprofen 2,400 mg daily. The primary endpoint was the improvement
of the WOMAC osteoarthritis index after 15 days of therapy. The analysis was by
intention to treat. RESULTS: The evaluation of the WOMAC OA index showed
statistically significant equivalence of dexibuprofen 400 mg t.i.d. compared with
racemic ibuprofen 800 mg t.i.d. by a Mann-Whitney statistic of 0.578 and the
corresponding lower bound of the 95% confidence interval of 0.498. The test for
superiority of dexibuprofen was borderline significant with p = 0.055.
Dexibuprofen 400 mg t.i.d. and dexibuprofen 200 mg t.i.d. showed a statistically
significant dose-response relationship in improving the WOMAC OA index (p =
0.023). Patients suffered from adverse drug reactions, mainly gastrointestinal
disorders, 13.34% on dexibuprofen 200 mg, 15.25% on dexibuprofen 400 mg and
16.94% on racemic ibuprofen 800 mg. CONCLUSIONS: The active enantiomer
dexibuprofen (S(+)-ibuprofen) proved to be an effective non-steroidal anti
inflammatory drug with a significant dose-response relationship in patients with
painful osteoarthritis of the hip. Compared with racemic ibuprofen half of the
daily dose of dexibuprofen shows at least equivalent efficacy. In contrast to
pharmacokinetic data, the additional administration of R(-)-ibuprofen in form of
racemate does not contribute to the clinical efficacy of racemic ibuprofen.
PMID- 10667833
TI - In vivo binding characteristics of phenytoin to serum proteins in monotherapy
pediatric patients with epilepsy.
AB - AIM: The aim of the present study was to determine the binding characteristics of
phenytoin (PHT) to serum proteins in the pediatric population. Binding parameters
of PHT to serum proteins in our study were conducted to compare with in vivo or
in vitro binding parameters of PHT to serum proteins in adult subjects reported
by other investigators. SUBJECTS AND MATERIALS: Serum samples in the study were
obtained from 40 pediatric patients (16 male, 24 female) receiving PHT
monotherapy. Their age ranged from 1 to 15 years (9.2 +/- 3.6 years, mean +/-
SD). The in vivo population binding parameters of PHT to serum proteins and
theoretical minimal unbound serum PHT fraction (fu) were determined using an
equation derived from the Scatchard equation. RESULTS: The association constant
(Ka) was 0.014 l/micromol, while the total concentration of binding sites (n(Pt))
was 747 micromol/l. The number of binding sites per albumin molecule (n) was
1.13, while binding ability (n x Ka) was 0.0161/micromol. The fu was 0.087. The n
x Ka is approximately 1.2 times higher in PHT monotherapy adult patients of
Pospisil et al. [1992] (i.e. 0.0191 l/micromol) than in all our patients. The
association constant is approximately 1.3 times higher in the in vitro study of
Monks et al. [1978] (i.e. 0.0186 l/micromol) than in our study, while n is
similar between the two studies. The fu in our pediatric patients is similar to
the unbound serum PHT fraction in adult patients receiving PHT therapy reported
by Richens [1979] (i.e. 0.1). CONCLUSION: Our results suggest that there may be
small differences in the binding characteristics of PHT to serum proteins between
Japanese pediatric and non-Japanese adult subjects. The unbound serum fraction of
PHT in pediatric patients with epilepsy can be assumed to be relatively constant
in the therapeutic concentration range of PHT.
PMID- 10667834
TI - Analysis of point mutation in exon 2 of CYP2E1 gene in renal cell/urothelial
cancer patients in comparison with control population.
AB - OBJECTIVE: Genetic polymorphisms of human cytochrome P450s have been implicated
to be of importance for susceptibility to different cancers. Recently, a point
mutation was found in the exon 2 of the CYP2E1 gene (CYP2E1*2) [Hu et al. 1997].
In order to evaluate a possible link between the point mutation in exon 2 of the
CYP2E1 gene and the susceptibility to renal cell/urothelial cancer, we developed
a screening method based on the polymerase chain reaction (PCR) and restriction
fragment length polymorphism (RFLP). MATERIAL: DNA of peripheral white blood
cells was isolated from 158 renal cell/urothelial cancer patients as well as from
150 controls. METHOD: Primers for PCR were designed by the Primer 3 release 0.1
program. The PCR yield a product of 215 base pairs (bp), which was digested with
the restriction enzyme Hha I. The DNA fragments were separated on a 3% agarose
gel stained with ethidium bromide. Restriction enzyme digestion of the PCR
product obtained from the wild-type DNA resulted in the appearance of a 66 bp, a
43 bp, a 40 bp, a 39 bp and a 28 bp DNA fragment. In contrast to the wild-type,
the digestion of the PCR product from DNA carrying the point mutation resulted in
the loss of the 39 bp and 40 bp fragments and the appearance of an additional 79
bp fragment. Therefore, the loss of one Hha I restriction site caused by a single
nucleotide exchange is suitable for the identification of the point mutation in
exon 2 of CYP2E1 gene. RESULTS: However, we could not detect any point mutation
in any of the 158 renal cell/urothelial cancer patients or the 150 controls. The
distribution of the point mutation in exon 2 of CYP2E1 gene did not show any
difference in renal cell/urothelial cancer patients and controls. CONCLUSION:
This might indicate a lack of association between this CYP2E polymorphism
(CYP2E1*2) and renal cell/urothelial cancer.
PMID- 10667835
TI - Alpha 1-acid glycoprotein (AAG) and serum protein binding of methadone in heroin
addicts with abstinence syndrome.
AB - OBJECTIVE: To quantify serum protein levels and protein-binding of methadone in
vitro in heroin-addicted patients showing objective signs of heroin abstinence.
SUBJECTS AND METHODS: Serum samples were obtained from patients (n = 27)
hospitalized to participate in a methadone detoxification program and from
healthy volunteers (n = 21). The severity of the abstinence syndrome was assessed
before blood sampling using a standardized scale. Concentrations of both albumin
and alpha1-acid glycoprotein (AAG) were measured in all serum samples. The
protein-binding of alpha1-methadone was determined by the ultrafiltration
technique and the unbound concentration was measured by liquid scintillation
counting. RESULTS: The mean of the AAG concentrations was significantly increased
in patients showing signs of withdrawal while the albumin concentrations did not
change. Also, the unbound methadone was significantly decreased in this group
when compared to the control. A positive correlation (Pearson r = 0.48; p <
0.005) indicates that AAG levels rise during abstinence as the score of
withdrawal symptoms increases. Additionally, pooled data from all individuals
show the binding of methadone to be related to AAG (r = 0.46; p < 0.05) levels
and not to albumin. CONCLUSIONS: The observed changes in protein-binding in
abstinence individuals suggest the need for increased dosages of methadone when
such patients are treated. Levels of AAG or protein-binding appear to be
components of the interindividual variance observed in the response to methadone
treatment, hence these variables could be included in future kinetic and dynamic
studies.
PMID- 10667836
TI - Influence of the administration of amifostine on the pharmacokinetics of 5
fluorouracil in patients with metastatic colorectal carcinoma.
AB - A high dose antineoplastic therapy with 5-fluorouracil (5-FU) is associated with
severe side effects. It is thought that the cytoprotective drug amifostine can
reduce these side effects when it is given prior to a chemotherapeutic course. In
this study, the pharmacokinetic parameters of 5-FU are monitored in six patients,
who received two chemotherapeutic courses of 2,600 mg/m2 BSA 5FU over 24 h, one
course with 700 mg/m2 BSA amifostine prior to the 5-FU infusion and the other
without. 20 serum samples were drawn during each infusion time and the 5-FU
concentrations were determined by a sensitive and selective GC-MS assay. The
statistical analysis of the serum concentrations revealed no significant
differences in the pharmacokinetic parameters of 5-FU, whether amifostine is
administered or not. The conclusion can be drawn that a reduction of side effects
is due to the cytoprotective effect of amifostine and not to a change in the
serum concentrations of 5-FU.
PMID- 10667837
TI - Specific inhibitors of inducible nitric oxide synthase: efficacy in a rodent
model of sepsis.
PMID- 10667838
TI - Loss of body cell mass in patients with systemic lupus erythematosus.
PMID- 10667839
TI - In vivo lymphoproliferation in the popliteal lymph node (PLN) assay can be
inhibited by leflunomide's active metabolite A77 1726.
PMID- 10667840
TI - Disease-modifying activity of malononitrilamides, derivatives of leflunomide's
active metabolite, on models of rheumatoid arthritis.
PMID- 10667841
TI - Cell cycle regulation and inhibition of de novo pyrimidine biosynthesis by
leflunomide.
PMID- 10667842
TI - Generation of O2- radicals in macrophages can be inhibited in vitro and in vivo
by derivatives of leflunomide's primary metabolite.
PMID- 10667843
TI - The ability of nicotine to induce glycosaminoglycan release in porcine nasal
cartilage explant cultures.
PMID- 10667844
TI - Reactive oxygen species generation by mast cells in response to substance P: a
NK1-receptor-mediated event.
PMID- 10667845
TI - Identification of IL-1 regulated genes in human synovial and gingival fibroblasts
by differential display.
PMID- 10667846
TI - Cytokines regulate the expression of cellular adhesion molecule in microvascular
endothelial cells (MVEC).
PMID- 10667847
TI - Granulocyte-colony stimulating factor decreases glycosaminoglycan concentration
and increases nitric oxide production in rat articular cartilage.
PMID- 10667848
TI - The antiproliferative effect of malononitrilamides (MNAs) on vascular smooth
muscle cells is antagonized by exogenous uridine.
PMID- 10667849
TI - Ex vivo assays demonstrate potency and selectivity of the COX-2 inhibitor DFP
after single dose administration.
PMID- 10667850
TI - Trisomy 7 in synovial fibroblasts obtained from arthritic joints.
PMID- 10667851
TI - Chronic rejection: the result of uncontrolled remodelling of graft tissue by
recipient mesenchymal cells? Data from two rodent models and the effects of
immunosuppressive therapies.
PMID- 10667852
TI - Induction of COX expression by a tobacco carcinogen: implication in lung cancer
chemoprevention.
PMID- 10667853
TI - Induction of Tr1 cells: a possible mechanism in the therapeutic action of OM-89.
PMID- 10667854
TI - Agonism at melanocortin receptor type 3 on macrophages inhibits neutrophil
influx.
PMID- 10667855
TI - Selectively 2H-labeled Glu/Asp: application to pKa measurements in Abeta amyloid
peptides.
AB - Human Abeta peptides have been linked to Alzheimer's disease, and it is
hypothesized that formation of amyloid as well as neurotoxicity are important
events in the etiology of the disease. Previous studies have shown that the
soluble precursor to Alzheimer's amyloid undergoes a pH-dependent folding
transition as the self-assembly activity appears, and based upon inter-residue
proximities, it was suspected that stabilization of the soluble form might rely
upon formation of an intramolecular salt-bridge. However, pKa studies on a model
17-residue Abeta fragment supported an electrostatic model where a solvation
imperative for charged side-chain atoms drives the folding process. To explore
this model in an active 26-residue fragment as well as the full-length 40-residue
Abeta peptide, pKa measurements were performed via 1H and 2H NMR. To overcome
issues related to sensitivity and spin system degeneracy, specifically deuterated
allyl protected-Fmoc amino acids were synthesized for incorporation into a series
of peptides, and a high sensitivity 2H observe NMR probe was constructed.
PMID- 10667856
TI - Synthesis and immunological studies of alpha-conotoxin chimera containing an
immunodominant epitope from the 268-284 region of HSV gD protein.
AB - We have synthesized and characterized new chimeric peptides by inserting an
epitope of the glycoprotein D (gD) of herpes simplex virus (HSV) serotype 1 as
'guest' sequence in the 'host' structure of alpha-conotoxin GI, a 13-residue
peptide (ECCNPACGRHYSC) isolated from the venom of Conus geographus. The 276-284
region of HSV gD-1 selected for these studies is highly hydrophilic and adopts a
beta-turn. The alpha-conotoxin GI also contains a beta-turn in the 8-12 region,
stabilized by two disulfide bridges at positions 2-7 and 3-13. Thus, the tetramer
sequence of alpha-conotoxin, 8Arg-His-Tyr-Ser12 has been replaced by Asp-Pro-Val
Gly (DPVG), identified previously as the epitope core. The syntheses were
performed by Fmoc strategy on Rink resin and DTNB or air oxidation were applied
for the formation of the first 3-13 disulfide bond in the presence of guanidinium
hydrochloride. For the formation of the second disulfide Cys2-Cys7 three
different oxidation procedures [iodine in 95% acetic acid, air oxidation in
dimethyl sulfoxide/1 M HCl or Tl(tfa)3 in trifluoroacetic acid (TFE)] were
compared. The high-performance liquid chromatography purified peptides were
characterized by electrospray mass spectrometry and amino acid analysis. The
bicyclic HSV-alpha-[Tyr1]-conotoxin chimeric peptide and native alpha-conotoxin
GI showed similar circular dichroism spectra in phosphate-buffered saline (PBS)
and in a PBS-TFE 1:1 (v/v) mixture, which might suggest that these compounds also
share similar secondary structures. In immunologic studies the characteristics of
the primary and of the memory immunoglobulin (Ig) M- and IgG-type antibody
responses showed that the bicyclic HSV-alpha-[Tyr1]-conotoxin chimera is capable
to induce strong antibody responses in C57/Bl/6 mice but was poorly immunogenic
in CBA and BALB/c mice. Data obtained with the C57/Bl/6 serum indicate that the
polyclonal antibodies recognize the DPVG motif presented in the bicyclic HSV
alpha-[Tyr1]-conotoxin and some reactivity was also found with the monocyclic but
not with the linear form of the chimera. Results with two IgM type monoclonal
antibodies from a bicyclic HSV-alpha-[Tyr1]-conotoxin immunized C57/Bl/6 mouse
also point to the specific interaction with the DPVG sequence. Taken together
these studies suggest, that the relative intensity of DPVG-specific responses was
found to be dependent on the mouse strain and on the conformation of the chimeric
molecules. We found that the IgM monoclonal antibodies are able to recognize the
linear DPVG sequence, while the majority of IgG antibodies is directed to the
same motif in a conformation stabilized by double cyclization.
PMID- 10667857
TI - Assignment of the disulfide bonds of Ole e 1, a major allergen of olive tree
pollen involved in fertilization.
AB - The most prevalent allergen from olive tree pollen, Ole e 1, consists of a single
polymorphic polypeptide chain of 145 amino acids which includes six cysteine
residues at positions 19, 22, 43, 78, 90 and 131. By using an homogeneous form of
the allergen expressed in Pichia pastoris, the array of the disulfide bridges has
been elucidated. Specific proteolysis with thermolysin and reverse-phase HPLC
separation of the peptides allowed the determination of the disulfide bond
between Cys43 and Cys78. Another thermolytic product, which contained three
peptides linked by the remaining four cysteines, was digested with Glu-specific
staphylococcal V8 protease and the products isolated by reverse-phase HPLC. Amino
acid compositions and Edman degradation of the peptide products indicated the
presence of the disulfide bonds at Cys19-Cys90 and Cys22-Cys131. These data can
help in the analysis of the three-dimensional structure of the protein as well as
in studies of its allergenic determinants.
PMID- 10667858
TI - Synthesis and characterization of Respiratory Syncytial Virus protein G related
peptides containing two disulfide bridges.
AB - Respiratory Syncytial Virus (RSV) is the most important cause of bronchiolitis
and viral pneumonia in infants and young children. Approximately 100000 children
are hospitalized in the USA each year as a result of RSV infections. During the
research and development of subunit human Respiratory Syncytial Virus vaccines
(hRSV), we have produced numerous synthetic peptides and recombinant proteins
containing the four cysteines of the highly conserved central region of the G
attachment protein. For several of these disulfide-containing peptides, all
possible oxidized isomers were synthesized using various oxidation conditions and
resulting in different ratios of isomers. Each isolated isomer was fully
characterized by RP-HPLC, FZCE and ES-MS after purification by preparative RP
HPLC. The different cysteine pairings were unambiguously established after
enzymatic digestion, LC-MS analysis and peptide microsequencing. These synthesis
and analytical methods were developed for the characterization on one hand, of
recombinant fusion protein BBG2Na which is currently being investigated in
advanced clinical phases as a very promising vaccine candidate, and on the other
hand, for peptides which were synthesized to be evaluated as conjugate vaccines
or as immunochemical tools, after covalent coupling to carrier proteins.
Furthermore, these studies allowed us to determine which of the different
possible isomers was the most stable and probably the preferred form in native
conditions. Finally, the different oxidation and analysis conditions, should be
useful for disulfide pairing studies of other peptides and proteins having the
same 'xCxxCxxxxxCxxxCx' framework, such as G proteins of non-human RSV strains,
developed by other groups as veterinary vaccine candidates for example.
PMID- 10667859
TI - Study of the alkylation propensity of cations generated by acidolytic cleavage of
protecting groups in Boc chemistry.
AB - The alkylation of cysteine residue by different classes of carbonium ions,
derived from the cleavage of side chain protective groups in anhydrous HF, was
investigated. It was found that side chain protection as beta-2,4-dimethylpent-3
yl ester (Dmp) or 2,4-dimethylpent-3-yloxycarbonyl (Doc) groups resulted in more
than seven-fold lower level of alkylated byproducts. This makes Dmp and Doc
protection of amino acid side chain during solid phase synthesis particularly
valuable in the synthesis of peptides containing cysteine residues or other
functional groups prone to alkylation by carbonium ions.
PMID- 10667860
TI - Photodynamic effect in lysozyme: a kinetic study in different micellar media.
AB - The influence of medium heterogeneity on the kinetics of the photodynamic effect
on native protein lysozyme (Lyso), as well as the interaction of protein and the
medium, anionic (SDS) micelles, neutral (Triton X-100) micelles and reversed
micelles of AOT, were investigated at pH 8. The interaction between Lyso, Triton
X-100 and SDS micelles was quantified by determining the respective associations
constant (K(Lyso)). Values were 37 M(-1) for Triton X-100 and 514 M(-1) for SDS,
indicating that the Lyso molecule binds Triton X-100 micelles effectively and SDS
micelles even more strongly. Time-resolved phosphorescence detection (TRPD)
indicates that the protein interacts with O2 (1deltag), with overall rate
constants of the order of 10(8) M(-1)/S in direct micelles and 10(7) M(-1)/S in
reverse micelles. Apparent reactive rate constants for eosin-sensitized photo
oxidation (singlet molecular oxygen [O2 (1deltag)]-mediated) of the protein were
determined through oxygen uptake experiments for the direct micelles, while the
fade in the protein fluorescence spectrum upon sensitized irradiation was used in
AOT. The results indicate that the O2 (1deltag) attack on the interior of Lyso on
amino acid residues, was more effective in leading to a photo-oxidative reaction
in SDS and in Triton X-100 at surfactant concentrations < 1 x 10(-2) M than in a
homogeneous solution. However, Lyso reactivity reached a maximum when the
concentration of micelles was approximately 1 x 10(-5), the same as the protein
concentration In AOT reverse micelles, the quenching rate constants decreased >
75% with respect to water. This effect can be attributed to the decrease in
accessibility of the amino acid residues to O2 (1deltag).
PMID- 10667861
TI - Relationship between the tertiary structures of mastoparan B and its analogs and
their lytic activities studied by NMR spectroscopy.
AB - Mastoparan B (MP-B), an antimicrobial cationic tetradecapeptide amide isolated
from the venom of the hornet Vespa basalis, is an amphiphilic alpha-helical
peptide. MP-B possesses a variety of biological activities, such as mast cells
degradation histamine release, erythrocyte lysis and inhibition of the growth of
gram-positive and gram-negative bacteria. In order to study the relationship
between the structure and the biological activity of MP-B, we used four analogs
by replacing amino acids with alanine. Tertiary structures of MP-B and its
analogs in 2,2,2-trifluoroethanol (TFE)-containing aqueous solution have been
determined by NMR spectroscopy and molecular modeling. The results indicate that
[Ala4]MP-B and [Ala12]MP-B with higher hydrophobicity adopt a higher content of
amphiphilic helical structures, and have better antimicrobial and hemolytic
activities than MP-B. However, [Ala3]MP-B and [Ala9]MP-B with lower
hydrophobicity have disordered structures. [Ala3]MP-B and [Ala9]MP-B have low
antimicrobial activity and much less hemolytic activity relative to MP-B. It is
likely that tryptophan residue in MP-B and appropriate hydrophobicity of MP-B to
induce alpha-helical structure is essential for the antibacterial and hemolytic
activity of MP-B. This study can aid understanding of the structure-activity
relationship of MP-B and to design peptides to possess lytic activity.
PMID- 10667862
TI - Conformational properties of a cyclic peptide bradykinin B2 receptor antagonist
using experimental and theoretical methods.
AB - The solution conformation of the cyclic peptide J324 (cyclo0,6-[Lys0,Glu6,D
Phe7]BK), an antagonist targeted at the bradykinin (BK) B2 receptor, has been
investigated using experimental and theoretical methods. In order to gain insight
into the structural requirements essential for BK antagonism, we carried out
molecular dynamics (MD) simulations using simulated annealing as the sampling
protocol. Following a free MD simulation we performed simulations using nuclear
Overhauser enhancement (NOE) distance constraints determined by NMR experiments.
The low-energy structures obtained were compared with each other, grouped into
families and analyzed with respect to the presence of secondary structural
elements in their backbone. We also introduced new ways of plotting structural
data for a more comprehensive analysis of large conformational sets. Finally, the
relationship between characteristic backbone conformations and the spatial
arrangement of specific pharmacophore centers was investigated.
PMID- 10667863
TI - Analysis of binding sites and efficacy of a species-specific peptide at rat and
human neurotensin receptors.
AB - We have developed a neurotensin analog, L-[3,1'-naphthylalanine11]NT(8-13), NT34,
that can distinguish between rat and human neurotensin receptors, and exhibits
more than a 100-fold difference in binding affinities and a 60-fold difference in
functional coupling to phosphatidylinositol turnover. Using cells transfected
with different numbers of the appropriate receptors, we measured the changes in
phosphatidylinositol production, and then evaluated the efficiency of receptor
effector coupling based on Furchgott's design. The binding of NT34 at both rat
and human neurotensin receptors stably expressed in CHO-K1 cells was to two
sites, while the binding of NT was to one site. At the rat receptor the
equilibrium dissociation constant (Kd) for NT34 at the high-affinity site was
0.058 nM, while that at the low-affinity site was 3.1 nM. For the human receptor
at the high-affinity site, the Kd for NT34 was 18 nM, while that at the low
affinity site was 180 nM. For both species the percentage of receptors
representing the high-affinity site was approximately 60-70% with 30-40% at the
low-affinity site. We derived agonist dissociation constants (Ka) for NT and
NT34, which suggest that for NT34, the low-affinity site is functionally coupled
to phosphatidylinositol turnover. Finally, we compared the relative efficacies of
both compounds and found that NT34 was about 2-fold and 4-fold more efficacious
than NT in stimulating phosphatidylinositol turnover in rat and human NT
receptors, respectively.
PMID- 10667864
TI - Chemical synthesis and receptor binding of catfish somatostatin: a disulfide
bridged beta-D-Galp-(1-->3)-alpha-D-GalpNAc O-glycopeptide.
AB - The glycopeptide hormone catfish somatostatin (somatostatin-22) has the amino
acid sequence H-Asp-Asn-Thr-Val-Thr-Ser-Lys-Pro-Leu-Asn-Cys-Met-Asn-Tyr-Phe-Trp
Lys-Se r-Arg-Thr-Ala-Cys-OH; it includes a cyclic disulfide connecting the two
Cys residues, and the major naturally occurring glycoform contains D-GalNAc and D
Gal O-glycosidically linked to Thr5. The linear sequence was assembled smoothly
starting with an Fmoc-Cys(Trt)-PAC-PEG-PS support, using stepwise Fmoc solid
phase chemistry. In addition to the nonglycosylated peptide, two glycosylated
forms of somatostatin-22 were accessed by incorporating as building blocks,
respectively, Nalpha-Fmoc-Thr(Ac3-alpha-D-GalNAc)-OH and Nalpha-Fmoc-Thr(Ac4-beta
D-Gal-(1-->3)-Ac2-alpha-D-GalNAc)-O H. Acidolytic deprotection/cleavage of these
peptidyl-resins with trifluoroacetic acid/scavenger cocktails gave the
corresponding acetyl-protected glycopeptides with free sulfhydryl functions.
Deacetylation, by methanolysis in the presence of catalytic sodium methoxide, was
followed by mild oxidation at pH 7, mediated by Nalpha-dithiasuccinoyl (Dts)
glycine, to provide the desired monomeric cyclic disulfides. The purified
peptides were tested for binding affinities to a panel of cloned human
somatostatin receptor subtypes; in several cases, presence of the disaccharide
moiety resulted in 2-fold tighter binding.
PMID- 10667865
TI - Changes inside Academic Medicine: why not a real cure instead of a band-aid?
PMID- 10667866
TI - Kampo medicine training in Japanese medical schools.
PMID- 10667867
TI - Book clubs in residents' education.
PMID- 10667868
TI - PubMed Central and the new publishing landscape: shifts and tradeoffs.
PMID- 10667869
TI - Protecting privacy without shackling providers.
PMID- 10667870
TI - Healthy people 2010: setting the nation's public health agenda.
PMID- 10667871
TI - Three strategies used by academic health centers to expand primary care capacity.
AB - The growth of managed care in the late 1980s and early 1990s severely
disadvantaged academic health centers (AHCs). The reliance on primary care
gatekeeping and selective contracting by managed care plans were two contributing
factors. Because most AHCs had only a modest primary care capacity, they were
understandably concerned about their strategic positions. Thus, many felt it was
essential to expand their primary care capacities to ensure downstream referrals,
to improve contract negotiations with third parties, and to permit assumption of
risk for defined populations. Among the different approaches used, three
principal strategies emerged for the expansion of the primary care capacity of
AHCs: (1) the "assembly strategy," in which many AHCs recruited new generalist
faculty into existing clinical departments; (2) the "acquisition strategy," in
which AHCs purchased established primary care practices in the community; and (3)
the "affiliation strategy," in which some AHCs affiliated with primary care
physicians in the community and formed networks of academic and community
physicians. For each of these approaches, the author reviews the relative merits
and disadvantages, and analyzes why some AHCs' original assumptions about the
imperative for increasing primary care capacity may have been spurious. He
concludes that recent marketplace and regulatory changes may make it less
necessary for AHCs to secure substantial primary care bases in the future.
PMID- 10667872
TI - Literature and medicine: origins and destinies.
AB - Literature and medicine is a flourishing subdiscipline of literary studies that
examines the many relations between literary acts and texts and medical acts and
texts. The author examines the historical connections between these two fields
and suggests that the growth and decline in medicine's attentiveness to the power
of words can be used as a marker for medicine's degree of attentiveness to the
individual patient's predicament. The recent explosive growth in medicine's
interest in literature and narrative is taken as evidence that medicine's swing
toward the reductionist and away from the narrative has ended. Patients and
doctors have reason to await the return swing of the pendulum-if not the turn of
the spiral-toward a medicine that is both technologically and narratively
competent.
PMID- 10667873
TI - Assessing the operating efficiencies of teaching hospitals by an enhancement of
the AHA/AAMC method. American Hospital Association/Association of American
Medical Colleges.
AB - In the ongoing effort to control costs, comparisons among hospitals' efficiency
levels, if valid, can help identify "best practices" across institutions and
uncover situations that need corrective intervention. The authors present an
extension of the "adjusted cost per equivalent discharge" approach, which
incorporates case-mix-severity differences, regional labor cost differentials,
and inpatient/outpatient mix, but does not take into account such factors as the
differences in hospital sizes, extents of the teaching mission, or quality of
care delivered. The alternative approach yields information that suggests where
an institution's total operating costs might be reduced with no change in any of
the hospital's outputs or operating environment, through comparison with a "peer
group" of other hospitals, matched according to the subject hospital's number of
beds, the quality of care the hospital delivers, the extent of medical education
carried out, the level of case-mix-adjusted discharges, and outpatient
activities. A difficulty with this approach (as with others) is that measurement
of some of the additional facets (e.g., quality of care) is still evolving, so
its main contribution at this time is to provide a construct and method capable
of incorporating these important added considerations. Hospital rankings achieved
by applying the current and alternative approaches to a real set of teaching
hospitals operating in FY 1987 are compared. While the rankings produced by the
two approaches are loosely similar, the authors show that some significant
differences do appear and can be at least partially explained by the
incorporation of the additional factors mentioned above.
PMID- 10667874
TI - An integrated residency in internal and preventive medicine.
AB - The importance of preventive and population-based principles in clinical practice
is widely acknowledged. The challenge of imparting these principles in either
undergraduate or postgraduate medical education has, however, not been fully met.
The necessary skills are provided comprehensively by preventive medicine
residency programs, but at the expense of clinical training. Sequential
residencies in primary care and preventive medicine, the currently available
means of obtaining thorough preparation in both clinical and population-based
principles, represent an inefficient, generally unappealing, and non-integrated
approach. In response to these concerns, and in an effort to make preventive
medicine training appeal to a wider audience, the authors developed and
implemented a residency program fully integrating internal and preventive
medicine. The program meets, and generally exceeds, the requirements of both
specialty boards over a four-year period. The program provides extensive training
in clinical, preventive, and public health skills, along with case management and
cost-effective care, conferring the MPH degree and leading to dual board
eligibility. The model is ideally wed to the demands of the modern health care
environment in the United States, is extremely attractive to applicants, and may
warrant replication both to train academic and administrative leaders and to
raise the standards of preventive and public health practice in primary care.
PMID- 10667875
TI - A thorough pulmonary exam and other myths.
PMID- 10667876
TI - A randomized controlled study of brief interventions to teach residents about
domestic violence.
AB - PURPOSE: To test an educational intervention regarding domestic violence. METHOD:
Residents beginning their training in 1995 or 1996 were randomly assigned to
attend, at their hospital orientation, either a 20-minute session emphasizing the
importance of screening for domestic violence or a session on an unrelated topic.
RESULTS: Seventy-one percent of the residents in the experimental group diagnosed
domestic violence; 52% in the control did so (RR, 1.35; 95% CI, 0.96-1.90; p =
.07) in the nine to 12 months following the intervention. Rates of diagnosis
differed by specialty (p < .01): 100% family practice, 90% emergency medicine,
80% obstetrics-gynecology, 63% pediatrics, 47% internal medicine, 0% surgery.
Change in knowledge was assessed in 1996; significant improvement was noted (p =
.002). CONCLUSION: An intervention about domestic violence conducted at
orientation for residents improved the rate of diagnosis of domestic violence.
While the improvement was not statistically significant in this case, the
intervention was brief and harmless. Other institutions should consider this kind
of brief intervention.
PMID- 10667877
TI - Teaching medical students about continuity of patient care.
AB - This article reports on medical schools' longitudinal primary care ambulatory
programs and five themes identified by educators as to why it is important for
students to experience continuity of patient care. It briefly describes methods
used to expose students to this concept, which is so basic to primary care
practice.
PMID- 10667878
TI - Evaluation of Web-based computer-aided instruction in a basic science course.
AB - PURPOSE: To demonstrate the applicability of server statistics, in combination
with user surveys, to evaluate utilization of Web-based computer-aided
instruction (CAI) in the undergraduate medical curriculum. METHOD: Individual
user surveys with students' names provided information about computer literacy
prior to the course and use of CAI during the course. Utilization of specific web
based CAI developed for the course was recorded by server software and the daily
logs correlated with course content. Regression analyses were used to measure
correlation of server access logs of individual students versus information from
user surveys and performances in the course based on in-course examinations.
RESULTS: There was no correlation between computer literacy of students at
matriculation and their subsequent levels of use of CAI in the curriculum.
Utilization of CAI developed for specific course objectives coincided closely
with course content, which is an indication of the effectiveness of the
applications in achieving their curricular objectives. In contrast, student use
of tutorials coincided most closely with in-course examinations. Students'
responses to surveys were generally substantiated by server statistics, but
discrepancies were sufficiently large (10% to 20%) to call into question the
validity of these surveys. Significant differences in CAI utilization correlated
with the performances of students in the course. CONCLUSIONS: This study
demonstrates an important advantage of web-based applications to collect and
evaluate CAI utilization efficiently and objectively at both the level of the
class and the level of the individual student.
PMID- 10667879
TI - Student performances on Step 1 and Step 2 of the United States Medical Licensing
Examination following implementation of a problem-based learning curriculum.
AB - PURPOSE: To examine students' performances on Step 1 and Step 2 of the United
States Medical Licensing Examination (USMLE) following the implementation of a
problem-based learning curriculum. METHOD: Performances on Step 1 of the USMLE
for four classes at the University of Missouri-Columbia School of Medicine that
completed a new problem-based learning curriculum (1997, 1998, 1999, and 2000)
were compared with those of the last two classes to learn in the traditional
curriculum (1995 and 1996). Performances on Step 2 of the USMLE for the classes
of 1997, 1998, and 1999 were also compared with those of the classes of 1995 and
1996. The authors analyzed matriculation data (GPAs and MCAT scores) for all six
classes. They compared all data with those of U.S. and Canadian first-time USMLE
takers. RESULTS: The mean scores were higher on USMLE Step 1 for classes in the
problem-based learning curriculum than for classes in the traditional curriculum.
The mean scores for Step 2 were above the national mean for classes in the
revised curriculum and below the national mean for classes in the traditional
curriculum. The admission profiles of these classes were essentially the same
before and after the change in curriculum. CONCLUSIONS: Major PBL revisions of
the curriculum did not compromise the performances of medical students on the
licensing examinations; in fact, they may have contributed to higher scores.
PMID- 10667880
TI - A pilot survey study to define quality in residency education.
AB - PURPOSE: To begin to define indicators of quality in internal medicine residency
training. METHOD: In 1995, through a modified Delphi process, the Association of
Program Directors in Internal Medicine's Research Committee developed a
questionnaire containing 44 items (34 process and ten outcome indicators). The
survey was mailed to all 418 internal medicine program directors and a
convenience sample of medical residents. RESULTS: Responding at a rate of 78%
(326), program directors rated several indicators as important. These included
such faculty characteristics as stability, completeness, supervision, clinical
skills, and teaching commitment; institutional support; amount of resident
evaluation and feedback; encouragement of lifelong learning; and ability to meet
its program goals. There was strong agreement between faculty and residents (r =
0.91). Items rated less important included graduates' selecting academic or
generalist careers, residents' caring for elective cardiac catheterization
patients, resident community service, training minorities and women, and faculty
research. CONCLUSION: These results demonstrate the diversity of opinion of what
defines quality in residency education and the emphasis placed on process rather
than outcome indicators. To be valid, future endeavors must include all those
with a stake in graduate medical education, including accrediting bodies, future
employers, and patients.
PMID- 10667881
TI - Program directors' perspectives on federally funded fellowship training in
primary care research.
AB - PURPOSE: To describe the organization, models of training, and institutional
impact of National Research Service Award fellowship programs in primary care
research. METHOD: Survey of 25 directors of currently-funded and former training
sites. RESULTS: Twenty-four program directors (96%) completed the survey.
Programs allocated 39% of fellows' time to course work leading to an advanced
degree or other didactic instruction, and 40% of time to the conduct of research.
Collaborations with other training programs within the institution occurred at
83% of sites. Programs commonly (54%) or exclusively (42%) relied on a research
model of "early research independence" in which the fellow defined an area of
research interest, rather than an "apprenticeship" model in which the fellow
worked in a senior investigator's research area. These programs enriched the
local academic environment, but required extensive financial subsidies. The high
costs of training often had adverse impacts on recruitment and other components
of the training process. CONCLUSION: Research training programs in primary care
often substitute acquisition of advanced degrees for early immersion in research.
The "early independence" model of research differs from fellowships in the
medical specialties, and requires further study to assess its effectiveness. The
need to subsidize training costs poses substantial problems for the institutions
that host these fellowship programs.
PMID- 10667882
TI - Using early clinical experiences to integrate quality-improvement learning into
medical education.
AB - Health care providers are delivering care in an increasingly complex environment;
this requires that providers develop new competencies to better understand their
work and to design changes that can help them succeed. Recognizing these new
educational requirements, Dartmouth Medical School created a model two-pronged
program for teaching quality improvement to its medical students. The goal of the
program is to provide students with an active learning experience as well as an
education in the theory and application of continuous quality improvement. The
program includes two educational experiences: one curriculum is for all medical
students and the other is for selected, highly motivated students. The first
curriculum is incorporated in Dartmouth's required "On Doctoring" course, in
which students spend time with community-based physician preceptors. The quality
improvement curriculum is designed around an improvement project developed at the
students' preceptor sites. The second curriculum for students with a special
interest in quality improvement is offered as an elective summer program between
the first and second years of medical school. Working in groups of two, students
identify an area for improvement within a preceptor's practice, assist the
practice in articulating an improvement plan, help implement that plan, and write
up their experiences. The authors describe the two curricula, factors associated
with their successful implementation, and lessons learned.
PMID- 10667883
TI - Eva's stories: recognizing the poverty of the medical case history.
AB - The medical case history is a proven tool for approaching the question "What is
wrong with this person?" Its virtues, however, can become vices, in part as a
consequence of the dehumanizing flight from sensitive subjectivity to sanitized
objectivity, from human interest to "science." The case history, because it is so
useful and effective, is not likely to be profoundly altered in the future, but
medical educators can make themselves and their students more aware of the
serious flaw in this form of discourse, i.e., the erasure of the unique
individual from his or her disease. The exercise of asking medical students to
abstract case histories from richly written short stories, novels, plays, or
operas might heighten students' recognition of the poverty of the medical case
history. To illustrate this idea, the story of Eva, a dying woman, is presented
initially as a typical medical case history; it is then contrasted with excerpts
from a novelist's narrative of Eva's life.
PMID- 10667884
TI - Teaching medical students clinical reasoning skills.
AB - To be an effective clinician, a physician must excel at clinical problem solving.
Nevertheless, few physicians have been specifically taught clinical reasoning
skills during their medical training. This paper describes the format used to
teach clinical problem solving to second-year medical students at the University
of Connecticut School of Medicine.
PMID- 10667885
TI - Glaucoma screening as a vehicle for providing continuing medical education.
AB - During a free screening at a major medical meeting, volunteer ophthalmologists
educated attendees about glaucoma. A questionnaire was given to participants
before and six months after the screenings to evaluate changes in their knowledge
of glaucoma risk factors; the results showed a significant and enduring
improvement (p < .02) in respondents' knowledge about glaucoma.
PMID- 10667886
TI - Integrating immunotoxicity with effects on other biological systems in
preclinical safety evaluation: a perspective.
PMID- 10667887
TI - Endocrine and neurological adverse effects of the therapeutic interferons.
AB - There is experimental evidence that the nervous central and the neuroendocrine
systems can influence the immune system, which can in turn influence the brain
activity. Endogenous cytokines are known to play a critical role in the
pathophysiology of many diseases. The recently acquired experience on the adverse
effects of therapeutic cytokines, particularly neurological and endocrine adverse
effects, are further illustrative of these interferences. Interferons-alpha have
been used in thousands of patients, so that the information accumulated with this
group of closely related products is essential to delineate the potential and
severity for non-immunological, but largely immune-mediated adverse effects to
develop in patients treated with immuno-activating agents.
PMID- 10667888
TI - Hepatic drug metabolism and immunostimulation.
AB - When host defence mechanisms are stimulated there is a concomitant decrease in
cytochrome P450 based drug biotransformation and elimination. This has resulted
in a number of clinically important unwanted drug responses in patients with
infections or inflammatory responses. The loss in cytochrome P450 is
predominantly an effect at the level of the gene expression and the majority of
enzyme forms examined to date are involved. Although the effect occurs
predominantly in the liver it has been recently shown that inflammatory responses
in the brain also cause a loss of the same enzyme forms in that organ. The loss
of cytochrome P450 in the brain in response to localised inflammation is
accompanied by a similar loss in the liver. The decrease of cytochrome P450 and
its dependent drug biotransformation is of concern whenever drugs are used in
patients with infections or disease states with an inflammatory component.
PMID- 10667889
TI - Past, present and future of psychoneuroimmunology.
AB - Psychoneuroimmunology was for the first time comprehensively described about 20
years ago. The influence of mental status on the course and outcome of a number
of diseases, however, was suspected a long time before. Also the links between
mental affective disorders and the immune status were repeatedly suggested. The
authors in this paper shortly reviewed the most important clinical as well as
experimental evidence which at present strongly supports the concept of a close
and bidirectional communication between central nervous, neuroendocrine and
immune systems. The most important anatomical, physiological as well as
pharmacological experimental data, which were obtained by the authors during 20
years of research in this field, are presented. The data strongly suggest that in
the very next future we will not only better understand a very complex
communication between mind and body, but also completely new types of compounds
might become available.
PMID- 10667890
TI - Central/peripheral nervous system and immune responses.
AB - Maintenance of health is dependent on numerous regulatory interactions between
organ systems. This review discusses interorgan communication between the
nervous, endocrine, and immune systems and environmental and genetic influences
on this neuroendocrine immune circuitry. Stresses of multiple types, including
psychological and exposure to chemicals and infectious agents, may combine to
enhance neuroimmunotoxicology. Altered nervous system functions can alter
immunity which could result in exacerbation of infections, cancers or other
immune-associated problems. Inversely, aberrant immune system activities could
lead to pathologies associated with altered nervous activities, such as
Alzheimer's disease, chronic fatigue, or multiple sclerosis. The nervous,
endocrine and immune circuitry is multi-directional, and a chemical, physical or
emotional stress could upset the homeostasis.
PMID- 10667891
TI - Epidermal cytokines in experimental contact dermatitis.
AB - Topical exposure to a variety of xenobiotics may result in irritant as well as
allergic contact dermatitis both in rodents and in humans. Despite their
induction by different mechanisms, they cannot be differentiated by macroscopic
appearance and, by histological examination they are both generally characterized
by a perivascular mononuclear cell infiltrate and capillary hyperpermeability.
Recently, cytokines, a family of inducible glycoproteins that play a pivotal role
in immune and inflammatory reactions, have been identified as useful tools for
differentiation of irritant and allergic contact dermatitis. In this article the
role of cytokines in the development and differentiation of irritant and allergic
contact dermatitis is discussed.
PMID- 10667892
TI - Approaches to the identification and recording of findings in the lymphoreticular
organs indicative for immunotoxicity in regulatory type toxicity studies.
AB - Recent validation studies showed that histopathological examination of the
hematopoietic and lymphoreticular system is one of the most sensitive tools in
the evaluation of non-specific immune stimulatory or immune suppressive effects
and hazard identification of potential immunotoxicity in routine safety tests.
Most immunotoxic effects have a classical dose-response relationship and an
immediate effect (i.e. do not need an induction phase). The findings associated
with a specific immunomodulatory response are generally not detected
morphologically in routine sections of the immune system in safety studies, but
may be detected, because of their effects on other organs such as skin (contact
dermatitis) or joints and kidneys (immune complex deposits). Careful detailed
examination of the immune system may give valuable clues for the possible
mechanism of action of the test material, as was also demonstrated in these
validation studies.
PMID- 10667893
TI - Genitourinary medicine and sexually transmitted infections in the 21st century.
PMID- 10667894
TI - A retrospective study of neutropenia in HIV disease.
AB - In aiming to define the characteristics of HIV-infected subjects developing
neutropenia and describe the causes, features and effects of neutropenia we
undertook a retrospective study in a dedicated HIV unit in London, UK. Two
hundred and forty-four patients with documented neutropenia, defined as absolute
neutrophil count (ANC) < 1,000/mm3, during a 12-month period were studied. First
neutropenia occurred at a median CD4 count of 30 cells/mm3. Low CD4 count was
associated with longer episodes of neutropenia with a more profound nadir. Two
thirds of episodes lasted less than 2 weeks. ANC nadir was < 500 cells/mm3 in 45%
of episodes. Infections were most frequent in patients with profound but brief
neutropenic episodes. Neutropenia was generally mild, short-lived and associated
with late-stage disease. However, profound neutropenia did develop suddenly in
some patients with no prior history of neutropenia (in 13% first neutropenic ANC
recorded was < or =500 cells/mm3), and at CD4 count > 200 cells/mm3. Most
patients were receiving multiple myelosuppressive therapies. Infection was
associated with brief, profound neutropenia.
PMID- 10667895
TI - Psychosocial impact of type-specific herpes simplex serological testing on
asymptomatic sexual health clinic attendees.
AB - The usefulness of type-specific testing for herpes simplex virus type 2 (HSV-2)
is much debated with proponents arguing for likely change in the sexual behaviour
of asymptomatic carriers and opponents suggesting that testing may have
significant adverse psychological impact while not promoting behaviour change. In
the present study we examine the impact of HSV-2 serological testing on
psychological well-being, self-esteem, anxiety, sexual self-perceptions and
sexual practices among a sample of 180 clients of a sexual health clinic. Of the
participants, 21 (11.7%) were HSV-2 positive at entry to the study. No adverse
psychological consequences of a positive test were observed among those
participants followed for 3 months (n=124) or for 6 months (n=97). There was
little significant change observed in sexual behaviour although a general but not
significant pattern of decreased sexual behaviour with casual partners was
observed among participants who tested HSV-2 negative. While supportive of the
value of HSV-2 testing, these findings require replication in larger samples and
different populations.
PMID- 10667897
TI - The effect of modest monetary incentives on follow-up rates in sexually
transmitted disease studies.
AB - The purpose of the study was to determine if follow-up rates in sexually
transmitted disease (STD) research could be improved by offering modest monetary
incentives. Women aged 14-34, infected with Chlamydia trachomatis, and enrolled
in either of 2 studies between May 1995 and January 1999 were included. Beginning
in March 1996 participants were offered a $20 incentive to return to both the one
and four-month follow-up visits. Data were analysed using polychotomous logistic
regression. Of 962 women followed, the majority (74.7%) received monetary
incentives and 66% returned for at least one visit. Women who received the
incentive were more likely (OR 1.9, CI 1.2-2.9) to return for either one or both
of their follow-up visits after adjusting for interviewer and the months of work
experience of that interviewer. Age and method of birth control were not
associated with return rates. The study provides evidence that modest monetary
incentives can improve follow-up rates.
PMID- 10667896
TI - Going underground and going after women: trends in sexual risk behaviour among
gold miners in South Africa.
AB - This paper examines trends in risk behaviour among South African gold miners, a
population with an estimated HIV prevalence of 10-20%. The study is based on a
1995 and 1997 survey of a random sample gold miners in the town of Welkom, South
Africa. The results show that the percentage of miners who perceived they were
likely to contract HIV increased from 33% in 1995 to 35% in 1997 (P<0.01). The
percentage who had 4 or more partners in the past year decreased from 25% to 13%
(P < 0.01), and the percentage whose last sexual partner was their spouse
increased from 56% to 70% (P<0.01). Condom use in last intercourse with a spouse
increased from 18% to 26% (P < 0.05). Condom use with other partners was
considerably higher (67%), but did not increase significantly from 1995. The most
likely contributors to this behaviour change were the AIDS awareness programmes
implemented by the mining industry and the behaviour change communications of a
condom social marketing campaign targeted at miners and commercial sex workers in
the mining community.
PMID- 10667898
TI - Seronegative HIV-2 carriers in India.
AB - The discordant cases of seronegative, but culture and proviral HIV-2 DNA positive
were found in Mumbai, India. This was corroborated by the successful isolation of
HIV-2-RNA in culture medium, HIV-2 cDNA sequence determination and the detection
of the antigen. The sequence of the isolated HIV-2 genomic RNA does not seem to
be altered to the extent that the change will alter antibody binding.
Furthermore, antibody from the same individual (even at 8 months from initial
sampling) from whom HIV-2 was isolated did not react with the antigen of this
strain. Those evidences imply that extremely low or non-production of the
antibody may be due to suboptimal immune stimulation due to extremely slow HIV-2
replication. This low virus-load may be responsible for the negative antibody
results in the HIV-2 carriers.
PMID- 10667899
TI - Secondary HIV transmission rates in a mixed-gender sample.
AB - Information about the sexual behaviour of HIV-infected individuals is needed to
predict the course of the sexually transmitted HIV epidemic in the US. The
present study provides model-based estimates of the secondary transmission rate
(i.e. the number of infections expected among the sex partners of already
infected individuals) for a sample of HIV-positive persons in Atlanta. A
mathematical model was used to estimate the secondary transmission rate of HIV
infection for a sample of HIV-positive men and women in Atlanta, based on their
self-reported sexual behaviour, extrapolated over a 15-year horizon. Separate
rates were calculated for different transmission routes, including: from women to
men-who-have-sex-with women (MSW) and from men-who-have-sex-with-men (MSM) to
other MSM. Sensitivity analyses were conducted to assess the impact of different
parametric and modelling assumptions. Restricted to the sub-sample that reported
transmission risk behaviours, the mean number of secondary infections was 0.14
for transmission from women to MSW; 0.31 for transmission from MSW to women; and
0.84 for MSM to MSM transmission. Bisexual men were at especially high
transmission risk, with 1.59 and 0.54 secondary infections expected among their
male and female partners, respectively. The main analysis indicates that, in this
sample, each current infection will lead to fewer than one future infection for
all groups other than bisexual men, which suggests that the epidemic is
contracting in this community, although this analysis cannot rule out the
possibility of a growing epidemic among MSM. This method can be used to identify
groups at high risk for HIV transmission and thereby to better target HIV
prevention resources.
PMID- 10667900
TI - Disease prevalence in women attending the STD clinic in Mumbai (formerly Bombay),
India.
AB - Our objectives were to determine the prevalence of Neisseria gonorrhoeae and its
association with other STD causing organisms. Three hundred and thirty-six
consecutive women (female sex workers (FSWs) and married contacts), attending a
sexually transmitted disease (STD) clinic in Mumbai, were screened for N.
gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis. Per speculum
examination was performed and clinical signs were recorded. Symptoms perceived by
the women were also recorded. The mean age for married contacts, FSWs and
gonorrhoea-positive women was 27.9, 29.7 and 27.5, respectively. 9.7% of the
women were positive for N. gonorrhoeae, 23.2% were chlamydia-positive and 5.9%
had trichomoniasis. N. gonorrhoeae was isolated more frequently from FSWs as
compared to the married contacts. The prevalence of HIV was significantly higher
among women with multiple sex partners (FSWs) (P<0.001). Gonococcal infection is
significantly associated with the presence of HIV. A significant association
between sexual habits and prevalence of gonorrhoea, trichomoniasis and HIV was
observed. The prevalence of gonorrhoea over 1988 to 1996 remained approximately
the same.
PMID- 10667901
TI - Increase in plasma IL-10 levels and rapid loss of CD4+ T cells among HIV-infected
individuals in south India.
AB - Increased levels of immune activation among HIV patients from developing
countries are believed to accelerate and/or enhance the shift to a Th2 cytokine
environment, which in turn may result in a more rapid progression to AIDS. In
support of this hypothesis, we present data from a cohort of 35 HIV+ individuals
in southern India. Among asymptomatic individuals in this cohort, a dramatic
increase in plasma interleukin (IL)-10 coincided with rapid decrease in CD4
counts and progression to AIDS. Serum IL-10 levels were significantly higher
after 6 months of follow up (P=0.01), while CD4 counts declined at a rate of 280
cells/ul per year, roughly 3 times the rate of decline reported for HIV+
asymptomatic subjects in developed countries. Changes in serum IL-10 levels and
CD4 counts fell short of statistically significant correlation (P=0.1). Among
AIDS patients in this cohort, the mean period from diagnosis of AIDS to death was
<5 months and is in agreement with an earlier report of rapid progression in
India.
PMID- 10667902
TI - The impact of zidovudine on dementia-free survival in a population of HIV
positive men and women on antiretroviral therapy.
AB - Our objective was to characterize the effect of zidovudine therapy on AIDS
dementia complex (dementia) free survival among HIV-infected men and women in a
population-based cohort with free access to antiretroviral therapy in the
province of British Columbia. Time to diagnosis of dementia among individuals was
examined on the basis of zidovudine duration, CD4+ cell count at first treatment,
gender, and transmission group [men having sex with men (MSM), intravenous drug
users (IDU), heterosexuals]. We restricted the analysis to subjects with CD4+
cells counts within 12 months prior to treatment start date. Among 641
participants eligible for analysis, median duration of follow-up was 3.6 years,
under which 86 (9.3%) events of dementia occurred. Participants were less likely
to develop dementia with: increased zidovudine exposure (OR=0.26, 95% CI: 0.14
0.49), at least 260 CD4+ cells/mm3 (median) (OR=0.52, 95% CI: 0.34-0.78), and MSM
risk group (OR=0.57, 95% CI: 0.35-0.94). Those infected through heterosexual
contact had an increased risk (RR=2.04, 95% CI: 1.02-4.07). Using Cox's
proportional hazards model, controlling for CD4+ cell count at treatment start
date, independent predictors of dementia-free survival were: duration of
zidovudine (OR=0.28, 95% CI: 0.15-0.52) and MSM transmission group (OR=0.61, 95%
CI: 0.37-1.00). In this observational treatment cohort, factors associated with
dementia-free survival include duration of zidovudine (AZT) therapy and MSM
transmission group. It is not clear from these data whether the AZT protective
effect is exclusive to this agent or whether other therapies might offer a
similar protective effect.
PMID- 10667903
TI - Perceived compliance with AZT dosing among a sample of African-American drug
users.
AB - The purpose of this report was to present findings from a pilot study conducted
to explore the associations between sociodemographic, drug use, and health belief
factors and perceived compliance with zidovudine (AZT) among African-American
drug users. Data were collected in Washington, DC, USA from individuals who were
African-American; were recent or current drug injectors or crack smokers; were
HIV-seropositive, and were receiving treatment for HIV infection. Participants
were recruited through local organizations that provide services to HIV-infected
persons. Participants were interviewed using a questionnaire that solicited
sociodemographic, lifetime and current drug use, current sexual behaviours,
health status, HIV and drug treatment history, and health belief data. Analyses
were limited to individuals currently using an illicit substance and who had
received AZT during their medical treatment. Parametric (Pearson's r) and
nonparametric (Spearman's rho) statistics were used to assess correlations
between perceived compliance with AZT dosing and independent variables. As the
study was intended to be both descriptive and exploratory, the level of
statistical significance was set at 0.10, rather than the customary 0.05.
Antiretroviral medications recognized and recalled by participants are presented.
The most commonly recalled medication was AZT. Slightly less than one-third of
participants reported being completely compliant with an AZT regimen. Perceived
compliance was found to be negatively associated with 5 variables: age,
homelessness, number of injections in the previous 30 days, trading sex for
drugs, and the perception that AIDS is no longer a serious disease since the
development of new antiretroviral medications. Intensity of feelings of joy,
fear, and the belief that taking more anti-HIV medications would result in better
health were found to be positively correlated. Bivariate associations between
perceived compliance and sociodemographic, drug use, sexual behaviour, and health
belief variables suggest further avenues of study and potential points for
intervention to increase compliance with antiretroviral medications among
racial/ethnic minority drug users receiving treatment for HIV infection.
PMID- 10667904
TI - Pneumocystis carinii pneumonia following discontinuation of primary prophylaxis
despite highly active antiretroviral therapy.
PMID- 10667905
TI - Sexually transmitted infections and cervical neoplasia.
PMID- 10667906
TI - Update on the experimental human model for chancroid infection.
PMID- 10667907
TI - Ciprofloxacin-resistant gonorrhoea.
PMID- 10667908
TI - Antibiotic prophylaxis and suction termination of pregnancy.
PMID- 10667909
TI - Termination of pregnancy, chlamydia and contact tracing.
PMID- 10667910
TI - A proposed BAT-26 germline polymorphism.
PMID- 10667911
TI - The role of NAC in amyloidogenesis in Alzheimer's disease.
PMID- 10667912
TI - Additional literature on "vasculogenic mimicry" not cited.
PMID- 10667913
TI - Surface antigen CD98(4F2): not a single membrane protein, but a family of
proteins with multiple functions.
PMID- 10667914
TI - Effect of calcium and calcium channel blockers on transient outward current of
F76 and D1 neuronal soma membranes in the subesophageal ganglia of Helix aspersa.
AB - Twin-electrode voltage-clamp techniques were used to study the effect of calcium
and calcium channel blockers on the transient outward current in isolated F76 and
D1 neurones of Helix aspersa subesophageal ganglia in vitro (soma only
preparation with no cell processes). On lowering extracellular Ca(2+)
concentration from 10 to 2 mm or removing extracellular calcium from the bathing
medium, the threshold for this current shifted in a negative direction by 11. 5
and 20 mV, respectively. On the other hand, increasing the extracellular Ca(2+)
concentration from 10 to 20 and to 40 mm shifted the steady-state inactivation
curves in positive directions on the voltage axis by 7 and 15 mV, respectively.
Upon application of calcium channel blockers, Co(2+), La(3+), Ni(2+) and Cd(2+),
transient potassium current amplitude was reduced in a voltage-dependent manner,
being more effective at voltages close to the threshold. The current was elicited
even at a holding potential of -34 mV. The specific calcium channel blockers,
amiloride and nifedipine did not shift the activation and steady-state
inactivation curves and did not reduce the transient outward current amplitude.
It was concluded that the transient outward current is not dependent on
intracellular Ca(2+) but that it is modulated by Ca(2+) and di- and trivalent
ions extracellularly. The effects of these ions are very unlikely to be due to a
surface charge effect because the addition of La(3+) (200 microm) completely
reverses the shift in a hyperpolarizing direction when the extracellular Ca(2+)
concentration was reduced from 10 to 1 mm and additionally shifts the kinetics
further still in a depolarizing direction. The responses seen here are consistent
with a specific effect of di- and trivalent ions on the transient outward current
channels leading to a modification of gating.
PMID- 10667915
TI - Influence of a transmembrane protein on the permeability of small molecules
across lipid membranes.
AB - The influence of the nonchannel conformation of the transmembrane protein
gramicidin A on the permeability coefficients of neutral and ionized alpha-X-p
methyl-hippuric acid analogues (XMHA) (X = H, OCH(3), CN, OH, COOH, and CONH(2))
across egg-lecithin membranes has been investigated in vesicle efflux
experiments. Although 10 mol% gramicidin A increases lipid chain ordering, it
enhances the transport of neutral XMHA analogues up to 8-fold, with more
hydrophilic permeants exhibiting the greatest increase. Substituent contributions
to the free energies of transfer of both neutral and anionic XMHA analogues from
water into the bilayer barrier domain were calculated. Linear free-energy
relationships were established between these values and those for solute
partitioning from water into decadiene, chlorobutane, butyl ether, and octanol to
assess barrier hydrophobicity. The barrier domain is similar for both neutral and
ionized permeants and substantially more hydrophobic than octanol, thus
establishing its location as being beyond the hydrated headgroup region and
eliminating transient water pores as the transport pathway for these permeants,
as the hydrated interface or water pores would be expected to be more hydrophilic
than octanol. The addition of 10 mol% gramicidin A alters the barrier domain from
a decadiene-like solvent to one possessing a greater hydrogen-bond accepting
capacity. The permeability coefficients for ionized XMHAs increase with Na(+) or
K(+) concentration, exhibiting saturability at high ion concentrations. This
behavior can be quantitatively rationalized by Gouy-Chapman theory, though ion
pairing cannot be conclusively ruled out. The finding that transmembrane proteins
alter barrier selectivity, favoring polar permeant transport, constitutes an
important step toward understanding permeability in biomembranes.
PMID- 10667916
TI - Functional characterization of glycosylation-deficient human P-glycoprotein using
a vaccinia virus expression system.
AB - P-glycoprotein (P-gp), the product of human MDR1 gene, which functions as an ATP
dependent drug efflux pump, is N-linked glycosylated at asparagine residues 91,
94, and 99 located within the first extracellular loop. We report here the
biochemical characterization of glycosylation-deficient (Gly(-)) P-gp using a
vaccinia virus based transient expression system. The staining of HeLa cells
expressing Gly(-) P-gp (91, 94, and 99N-->Q), with P-gp specific monoclonal
antibodies, MRK-16, UIC2 and 4E3 revealed a 40 to 50% lower cell-surface
expression of mutant P-gp compared to the wild-type protein. The transport
function of Gly(-) P-gp, assessed using a variety of fluorescent compounds
indicated that the substrate specificity of the pump was not affected by the lack
of glycosylation. Additional mutants, Gly(-) D (91, 94, 99N-->D) and Gly(-) Delta
(91, 94, 99 N deleted) were generated to verify that the reduced cell surface
expression, as well as total expression, were not a result of the glutamine
substitutions. Gly(-) D and Gly(-) Delta Pgps were also expressed to the same
level as the Gly(-) mutant protein. (35)S-Methionine/cysteine pulse-chase studies
revealed a reduced incorporation of (35)S-methionine/cysteine in full length Gly(
) P-gp compared to wild-type protein, but the half-life ( approximately 3 hr) of
mutant P-gp was essentially unaltered. Since treatment with proteasome inhibitors
(MG-132, lactacystin) increased only the intracellular level of nascent, mutant P
gp, the decreased incorporation of (35)S-methionine/cysteine in Gly(-) P-gp
appears to be due to degradation of improperly folded mutant protein by the
proteasome and endoplasmic reticulum-associated proteases. These results
demonstrate that the unglycosylated protein, although expressed at lower levels
at the cell surface, is functional and suitable for structural studies.
PMID- 10667917
TI - Thermal stability of the plasma membrane calcium pump. Quantitative analysis of
its dependence on lipid-protein interactions.
AB - Thermal stability of plasma membrane Ca(2+) pump was systematically studied in
three micellar systems of different composition, and related with the
interactions amphiphile-protein measured by fluorescence resonance energy
transfer. Thermal denaturation was characterized as an irreversible process that
is well described by a first order kinetic with an activation energy of 222 +/-
12 kJ/mol in the range 33-45 degrees C. Upon increasing the mole fraction of
phospholipid in the mixed micelles where the Ca(2+) pump was reconstituted, the
kinetic coefficient for the inactivation process diminished until it reached a
constant value, different for each phospholipid species. We propose a model in
which thermal stability of the pump depends on the composition of the amphiphile
monolayer directly in contact with the transmembrane protein surface. Application
of this model shows that the maximal pump stability is attained when 80% of this
surface is covered by phospholipids. This analysis provides an indirect measure
of the relative affinity phospholipid/detergent for the hydrophobic transmembrane
surface of the protein (K(LD)) showing that those phospholipids with higher
affinity provide greater stability to the Ca(2+) pump. We developed a method for
directly measure K(LD) by using fluorescence resonance energy transfer from the
membrane protein tryptophan residues to a pyrene-labeled phospholipid. K(LD)
values obtained by this procedure agree with those obtained from the model,
providing a strong evidence to support its validity.
PMID- 10667918
TI - Nitric oxide activates or inhibits skeletal muscle ryanodine receptors depending
on its concentration, membrane potential and ligand binding.
AB - We show that rabbit skeletal RyR channels in lipid bilayers can be activated or
inhibited by NO, in a manner that depends on donor concentration, membrane
potential and the presence of channel agonists. 10 microm S-nitroso-N-acetyl
penicillamine (SNAP) increased RyR activity at -40 mV within 15 sec of addition
to the cis chamber, with a 2-fold increase in frequency of channel opening
(F(o)). 10 microm SNAP did not alter activity at +40 mV and did not further
activate RyRs previously activated by 2 mm cis ATP at +40 or -40 mV. In contrast
to the increase in F(o) with 10 microm SNAP, 1 mm SNAP caused a 2-fold reduction
in F(o) but a 1.5-fold increase in mean open time (T(o)) at -40 mV in the absence
of ATP. 1 mm SNAP or 0.5 mm sodium nitroprusside (SNP) induced approximately 3
fold reductions in F(o) and T(o) at +40 or -40 mV when channels were activated by
2 mm cis ATP or in channels activated by 6.5 microm peptide A at -40 mV (peptide
A corresponds to part of the II-III loop of the skeletal dihydropyridine
receptor). Both SNAP-induced activation and SNAP/SNP-induced inhibition were
reversed by 2 mm dithiothreitol. The results suggest that S-Nitrosylation or
oxidation of at least three classes of protein thiols by NO each produced
characteristic changes in RyR activity. We propose that, in vivo, initial release
of NO activates RyRs, but stronger release increases [NO] and inhibits RyR
activity and contraction.
PMID- 10667919
TI - Activation and inactivation of mechanosensitive currents in the chick heart.
AB - The behavior of MS channels in embryonic chick ventricular myocytes activated by
direct mechanical stimulation is strongly affected by inactivation. The amplitude
of the current is dependent not only on the amplitude of the stimulus, but also
the history of stimulation. The MS current inactivation appears to be composed of
at least two contributions: (i) rearrangement of the cortical tension transducing
elements and (ii) blocking action of an autocrine agent released from the cell.
With discrete mechanical stimuli, the MS current amplitude in the second press of
a double press protocol was always smaller than the amplitude of the first MS
current. Occasionally, a large MS current occurred when the cell was first
stimulated, but subsequently the cell became unresponsive. For a series of
stimuli of varying amplitudes, the order in which they were applied to the cell
affected the size of the observed MS current for a given stimulus magnitude. When
continuous sinusoidal stimulation was applied to the cells, the MS current
envelope either reached a steady state, or inactivated. With sinusoidal
stimulation, the MS response could be enhanced or restored by simple perfusion of
fluid across the cell. This suggests that mechanical stimulation of the cells
produces an autocrine inhibitor of MS channels as well as resulting in cortical
rearrangement.
PMID- 10667920
TI - Whole-cell mechanosensitive currents in rat ventricular myocytes activated by
direct stimulation.
AB - Mechanosensitive channels may have a significant role in the development of
cardiac arrhythmia following infarction, but the data on mechanical responses at
the cellular level are limited. Mechanosensitivity is a ubiquitous property of
cells, and although the structure of bacteriological mechanosensitive ion
channels is becoming known by cloning, the structure and force transduction
pathway in eukaryotes remains elusive. Isolated adult rat ventricular myocytes
were voltage clamped and stimulated with a mechanical probe. The probe was set in
sinusoidal motion (either in, or normal to, the plane of the cell membrane), and
then slowly lowered onto the cell. The sinusoidal frequency was held constant at
1 Hz but the stimulation amplitude was increased and the probe gradually lowered
until a mechanically sensitive whole cell current was seen, which usually
followed several minutes of stimulation. The whole cell mechanosensitive current
in rat cells had two components: (i) a brief large inward current spike current;
(ii) a more sustained smaller inward current. The presence of the initial sharp
inward current suggests that some structure within the cell either relaxes or is
broken, exposing the mechanosensitive element(s) to stress. Metabolic changes
induced by continued stress prior to the mechanosensitive response may weaken the
elements that break producing the spike, or simple stress-induced fracture of the
cytoskeleton itself may occur.
PMID- 10667922
TI - Evaluation of Co-solvents with supercritical fluid extraction of atrazine from
soil.
AB - Supercritical fluid extraction (SFE) with CO(2) has been successfully applied to
herbicide extractions from soil. The objectives of this work were to compare
extraction efficiency of atrazine from soil using different types and quantities
of co-solvent modifiers under a specified set of SFE instrument conditions and to
determine the ruggedness of an optimized extraction program and co-solvent on
several soils with varying characteristics. The effect of 18 co-solvents on
atrazine extraction from Lufkin fine sandy loam was determined using a completely
randomized design with six replications. Extractions of Lufkin soil using the
more nonpolar co-solvents had recovery similar to extractions where no co-solvent
was added. The co-solvents that showed high extraction efficiency, low incidences
of restrictor plugging, and ease of cleaning extraction cells were acetone,
acetone:water mixtures (with and without 1% triethylamine), and acetonitrile. The
addition of 1% triethylamine (TEA) did not increase recovery significantly. The
9:1 acetone:water mixture with 1% TEA was used for the soil comparison because of
the high atrazine recovery and low water content. No differences in atrazine
recovery were detected between extractions of the four representative soils when
the same extraction conditions were employed. No cleanup steps were included in
the procedure, yet adequate chromatography results were obtained suggesting some
selectivity for this procedure. These data indicate that SFE with optimized
conditions and appropriate co-solvents is a relatively robust method that can
effectively be used in soil extractions of atrazine.
PMID- 10667923
TI - Fungal biomass in saltmarsh grass blades at two contaminated sites.
AB - Ascomycetous fungi are the principal drivers of the decomposition of shoots of
smooth cordgrass (Spartina alterniflora). Shoots of smooth cordgrass move into
the saltmarsh food web via the decomposition system. Therefore, influences on
saltmarsh ascomycetes by pollutants of saltmarshes could have far-reaching
impacts. Earlier examination of impacts of severe contamination of a Georgia
saltmarsh by mercury and polychlorinated biphenyls (PCBs) revealed little or no
influence of the toxicants on living standing crops or sexual productivities of
cordgrass ascomycetes. Extension of the examination of saltmarsh-ascomycete
response to sites containing other toxic pollutants (the chlorinated organocyclic
insecticide toxaphene; chromium, copper, and lead; and polycyclic aromatic
hydrocarbons [PAHs]) has shown that none of the additional toxicants engendered
saltmarsh-fungal responses in the form of reduced living standing crops or sexual
productivities. Thus the ascomycetes of the cordgrass-decay system appear to be
as resistant to anthropogenic-pollutant poisoning as smooth cordgrass itself.
Unless the fungal and plant resistance mechanisms involve degradation of the
toxicants, this may imply that saltmarshes are especially dangerous as receiving
sites for toxic waste because they may have the potential to readily move
toxicants into the food web.
PMID- 10667924
TI - Phototoxic evaluation of marine sediments collected from a PAH-contaminated site.
AB - The phototoxicity potential of PAH-contaminated field sediment was evaluated and
compared to standard sediment toxicity test results. Marine sediments were
collected from 30 sites along a presumed PAH sediment pollution gradient in
Elliot Bay, WA. Standard 10-day acute and 28-day chronic sediment toxicity tests
were conducted with the infaunal amphipods Rhepoxynius abronius and Leptocheirus
plumulosus using mortality and the ability to rebury as endpoints. The survivors
of these tests were then subjected to 1-h exposures to UV radiation with
mortality and reburial again determined. The most highly toxic sediments
identified in these experiments were evaluated further for toxicity and
phototoxicity by serially diluting them with uncontaminated sediment and
repeating the toxicity tests. Standard 10-day toxicity test results indicated
that over 70% of the sites sampled in Elliot Bay exhibited measurable toxicity
with nine sites being highly toxic to both species of amphipods. Results of
standard 28-day chronic sediment toxicity tests were similar. In contrast, almost
all of the sites were found to be highly phototoxic. Results indicated that
exposure to UV increased toxicity five- to eightfold. This suggests that standard
toxicity tests underestimate the potential ecological risk of PAH-contaminated
sediments in animals exposed to sunlight. However, only when PAH contamination
was between 0.05 and 1.0 toxic units would conducting a phototoxicity evaluation
add information to that gained from conducting a standard sediment toxicity test
alone.
PMID- 10667925
TI - Factors controlling the bioaccumulation of mercury, methylmercury, arsenic,
selenium, and cadmium by freshwater invertebrates and fish.
AB - Concentrations of mercury (Hg), methylmercury (MMHg), arsenic (As), selenium
(Se), and cadmium (Cd) were measured in atmospheric deposition, stream water, and
biota in two streams in western Maryland. Overall, concentrations were slightly
higher in the water of the lower pH Herrington Creek tributary (HRCT).
Bioaccumulation factors were also higher for HRCT compared to Blacklick Run
(BLK). MMHg concentrations in biota increased with trophic level and essentially
all the Hg was as MMHg in predatory insects and insectivorous/carnivorous fish.
Thus, the overall trophic status of the organism was indicated by the %MMHg in
its tissues. Levels of As, Se, Cd, and Hg, however, decreased with increasing
trophic level. Adsorption of As to the exoskeleton of invertebrates appears to be
an important accumulation mechanism. MMHg was distributed evenly throughout
crayfish and fish organs, whereas As, Se, Cd, and Hg were found in higher
concentrations in detoxifying organs. Concentrations in biota in this study were
somewhat elevated compared to other rural sites, but were less than those of
point source-contaminated sites. Overall, as atmospheric inputs to the two
watersheds were similar, the results of this study show the importance of water
chemistry in determining the bioaccumulation of the metals and metalloids into
insects. Subsequent transfer to higher trophic levels is related to both the
ability of the organisms to depurate and the mode of accumulation, either
directly from water or from food.
PMID- 10667926
TI - Toxicity of manganese to Ceriodaphnia dubia and Hyalella azteca.
AB - Manganese is a toxic element frequently overlooked when assessing toxicity of
effluents, sediments, and pore waters. Manganese can be present at toxic levels
in anoxic solutions due to increased solubility under chemically reducing
conditions, and it can remain at those levels for days in aerated test waters due
to slow precipitation kinetics. Ceriodaphnia dubia and Hyalella azteca are
freshwater organisms often used for toxicity testing and recommended for
assessments of effluents and pore waters. Lethal and reproductive-inhibition
concentrations of Mn were determined for C. dubia in acute 48-h tests and chronic
three-brood tests using animals <24 h old and between 24 and 48 h old.
Sensitivity of H. azteca to Mn was determined with 7-day-old animals in acute 96
h tests. Tests were run at three levels of water hardness to assess the
amelioratory effect, which was often significant. Manganese concentrations were
measured analytically at test initiation and after 96 h for calculation of
toxicity and determination of Mn precipitation during the tests. Minimal amounts
of Mn (=3%) precipitated within 96 h. LC(50)s determined for H. azteca
progressively increased from 3.0 to 8.6 to 13.7 mg Mn/L in soft, moderately hard,
and hard waters, respectively. The tolerance of C. dubia to Mn was not
significantly different between moderately hard and hard waters, but was
significantly lower in soft water. Manganese sensitivity of C. dubia was not
significantly different between the ages tested. Acute LC(50) values for C. dubia
averaged 6. 2, 14.5 and 15.2 mg Mn/L and chronic IC(50) values averaged 3.9, 8.5
and 11.5 mg Mn/L for soft, moderately-hard and hard waters, respectively.
Manganese toxicity should be considered when assessing solutions with
concentrations approaching these levels.
PMID- 10667927
TI - Relative acute toxicity of acid mine drainage water column and sediments to
Daphnia magna in the Puckett's Creek Watershed, Virginia, USA.
AB - Acid mine drainage (AMD) is produced when pyrite (FeS(2)) is oxidized on exposure
to oxygen and water to form ferric hydroxides and sulfuric acid. If produced in
sufficient quantity, iron precipitate, heavy metals (depending on soil
mineralogy), and sulfuric acid may contaminate surface and ground water. A
previous study of an AMD impacted watershed (Puckett's Creek, Powell River
drainage, southwestern Virginia, USA) conducted by these researchers indicated
that both water column and sediment toxicity were significantly correlated with
benthic macroinvertebrate community impacts. Sites that had toxic water or
sediment samples had significantly reduced macroinvertebrate taxon richness. The
present study was designed to investigate the relative acute toxicity of acid
mine drainage (AMD) water column and sediments to a single test organism (Daphnia
magna) and to determine which abiotic factors were the best indicators of
toxicity in this system. Nine sampling stations were selected based on proximity
to major AMD inputs in the watershed. In 48-h exposures, sediment samples from
three stations were acutely toxic to D. magna, causing 64-100% mortality, whereas
water samples from five stations caused 100% mortality of test organisms. Forty
eight-hour LC50 values ranged from 35 to 63% for sediment samples and 27 to 69%
for water column samples. Sediment iron concentration and several water chemistry
parameters were the best predictors of sediment toxicity, and water column pH was
the best predictor of water toxicity. Based on these correlations and on the fact
that toxic sediments had high percent water content, water chemistry appears to
be a more important adverse influence in this system than sediment chemistry.
PMID- 10667928
TI - Antipredatory behavior as an index of heavy-metal pollution? A test using snails
and caddisflies.
AB - The loss of behaviors that organisms use to avoid predation may serve as a
sensitive indicator of pollution. We tested the hypothesis that a correlation
exists in the field between heavy metal levels and antipredator behaviors. We
examined the antipredator behavior of aquatic caddisfly larvae and snails at
sites in the Coeur d'Alene basin of Northern Idaho which varied in their levels
of heavy metals. We tested the antipredator response of Physella columbiana
snails at 10 polluted lakes downstream from the Bunker Hill Environmental
Protection Agency (EPA) Superfund cleanup site. We then compared their behavior
to snails at 14 reference lakes. We placed the snails in a plastic testing
apparatus, exposed them to an extract of crushed snail, and then monitored their
movements to a normally preferred shaded area. We also tested the behavior of
caddisfly larvae from 36 sites from a total of 6 streams/rivers adjacent to the
Superfund site. Sites were located upstream and downstream of abandoned mines. We
located active larvae of four genera, simulated predation by grasping the animals
between thumb and forefinger (the larvae respond to being grasped by withdrawing
into their case), lifted them from the water for 3 s, and then placed them in an
adjacent, slower section of the stream. We then recorded how long it took each
larvae to partially emerge from its case and attempt to move away. Unlike
reference site snails, snails from heavy metal-polluted environments failed to
exhibit antipredator behaviors in response to crushed conspecifics. These results
are consistent with previous laboratory studies. We found no effect of heavy
metals on the antipredatory behavior of caddisfly larvae.
PMID- 10667929
TI - Comparative experimental study of cadmium and methylmercury trophic transfers
between the asiatic clam Corbicula fluminea and the crayfish Astacus astacus.
AB - Cadmium (Cd) and methylmercury (MeHg) trophic transfers were analyzed between the
Asiatic clam Corbicula fluminea and the crayfish Astacus astacus. Metal
bioaccumulation in crayfish was quantified after 5, 10, and 15 days of exposure
via daily ingestion of soft bodies of C. fluminea, previously exposed during 7
days to Cd (20 microg. L(-1)) and MeHg (4 microg. L(-1)). Bioaccumulation
kinetics in the predator were investigated at organ and tissue levels: hemolymph,
tail muscle, hepatopancreas, gills, stomach/mesenteron, intestine, green gland,
carapace. Trophic transfer rates were estimated at the whole organism level.
Results showed marked differences (1) in assimilation efficiencies, mean transfer
rates being 5% for Cd and 16% for MeHg; and (2) in the metal distribution within
the different tissue compartments of the crayfish: for Cd, the trophic uptake
leads to high concentrations in the hepatopancreas and small accumulation in the
muscle tissue; for MeHg, the highest levels of bioaccumulation occur in the green
gland and in the tail muscle. From an ecotoxicological point of view, these
experimental data suggest a small risk of Cd transfer between the crayfish and
predators, humans included; on the other hand, Hg distribution in the muscle and
accumulation trends in this tissue represent an obvious risk of transfer.
PMID- 10667930
TI - Effects of aerially applied fenthion on survival and reproduction of the panacea
sand fiddler, Uca panacea, in laboratory habitats.
AB - Sand fiddler crabs, Uca panacea, were exposed in laboratory habitats to measured
concentrations of ULV-grade fenthion via simulated aerial spray at 5% and 50% of
field rate application of 6-12 mg fenthion/m(2) (0.05-0.10 lbs fenthion/acre).
Two habitats served as controls, and two habitats served as replicates for each
of the test exposures. The aerial application was repeated 12 times between July
7, 1997, and August 15, 1997, during the period of the most active larval
production of the crabs. The resulting measured concentrations of fenthion at the
surface and in the water were consistently lower than what the application rate
would have suggested. Statistical analysis of total, daily larval counts showed a
periodicity of approximately 14 days that did not appear to be affected by
fenthion, at least at the 5% application rate, where a 15% reduction in larval
production was noted by the end of the second hatching cycle and a 25% reduction
by the end of the third. Larval production in the habitats exposed to the 50%
application rate was reduced by 18% at the end of the first hatching cycle, 77%
at the end of the second, and 100% at the end of the third hatching cycle. At the
end of the third hatching cycle, adult crab mortality observed at the surface was
0%, 3%, and 20% for the control, 5%-, and 50%-exposure habitats, respectively.
Three weeks after the final fenthion application, survival of adult crabs was
100% in the control habitats, 75% in the 5%-exposure habitats, and 3% in the 50%
exposure habitats. Survival of unfed first-stage zoeae released during the night
following the sprays averaged 4.6 +/- 0.9, 3.7 +/- 0.9 and 1.7 +/- 0.6 days for
control, 5%-, and 50%-exposure habitats, respectively. Forty-eight-hour LC-50s
(nominal) for fenthion exposure of adult crabs submerged in water and for first
stage zoeae were 215 microg fenthion/L and 0.8 microg fenthion/L, respectively.
PMID- 10667931
TI - Environmental monitoring of the kafue river, located in the Copperbelt, Zambia.
AB - Zambia is a country with an extensive mining industry with the majority of mines
located in the Copperbelt province. Through this region of the country, the Kafue
River drains and receives effluent water from mining activities as well as from
other industrial point sources. In addition, production of agricultural products
and pest control requires use of different pesticides in the area. Information on
industrial and agricultural pollution has not been clearly identified in Zambia,
and little attention has been paid to pollution control and possible impact of
metals, pesticides, and other persistent compounds in the environment. The
objective of this study was to introduce and to evaluate a few methodologies
based on in situ bioassays for environmental assessment to promote sustainable
and environmentally sound water resource management of the Kafue River. The
results show that caged threespot tilapia exposed downstream of industrial points
sources rapidly bioaccumulate several trace elements, i.e., Cd, Co, Cu, Cr, Ni.
These elements also occurred in much higher concentrations in water samples
downstream of the industrial area compared with a locality upstream. Furthermore,
the use of a semipermeable membrane device (SPMD) for passive absorption of
lipophilic pollutants in the water showed relatively high concentration of
several pesticides, i.e., DDT with major metabolites, PCB, and dieldrin. The
present study shows that only 2 weeks of in situ studies in waters contaminated
by pollutants affects in situ exposed fish and that the correlation between water
and tissue concentrations was relatively good. Both trace elements and persistent
organic pollutants occurred in such high concentrations that they must be
considered from ecotoxicological aspects and may affect aquatic animal health.
PMID- 10667932
TI - Benzo[a]pyrene toxicokinetics in rainbow trout (Oncorhynchus mykiss) acclimated
to different salinities.
AB - The effects of environmental salinity on the distribution, metabolism, and
elimination of benzo[a]pyrene (B[a]P) were examined in mature rainbow trout.
Trout acclimated to either fresh water (0 ppt, FW) or sea water (20 ppt, SW) for
3 weeks received a single 10 mg/kg intra-arterial injection of [(3)H]
benzo[a]pyrene (B[a]P) at their acclimation salinity or when subjected to an
acute salinity change. Statistically significant differences in the percent body
burden of B[a]P-derived radioactivity in various tissues were seen between fish
in FW versus SW. Significant differences in the distribution of B[a]P and its
metabolites were also noted when fish were subjected to an acute salinity change
after chemical injection. Modulation of B[a]P metabolism by environmental
salinity included: (1) significant differences in the proportions of Phase I
metabolites in the bile of FW- (2.3%) versus SW-acclimated (14.1%) fish, and (2)
alterations in the accumulations of specific metabolites (predominantly t-9, 10
dihydrodiol-B[a]P in FW fish, and 3-hydroxy-B[a]P in SW fish). The percentages of
the [(3)H]-B[a]P dose eliminated by 48 h was similar in FW and SW fish, but
decreased in fish subjected to an acute salinity change (FW 98.8% eliminated,
FW:SW 90.4%, SW 98.1%, and SW:FW 93.1%). Pharmacokinetic modeling confirmed that
acute salinity changes can result in longer terminal half-lives and slower total
body clearances of B[a]P.
PMID- 10667933
TI - Effect of maintaining rainbow trout in creosote microcosms on lens optical
properties and liver 7-ethoxyresorufin-O-deethylase (EROD) activity.
AB - Previously, exposure of fish to polycyclic aromatic hydrocarbons (PAHs) in both
field and laboratory settings has been associated with eye damage, but this has
only been expressed qualitatively. In this study, an automated scanning laser
system has been employed to quantitatively evaluate changes in lens optical
quality in rainbow trout (Oncorhynchus mykiss) following their in vivo exposure
to creosote, which is a complex mixture with many PAHs. Rainbow trout were placed
in 12,000-L outdoor microcosms dosed with 0, 3, or 10 microl/L liquid creosote
for a 28-day period. Collected fish were examined for changes in focal length
variability (FLV), lens size, and weight. These measurements were compared with
induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity and hepatic and
water concentrations of priority pollutant PAHs. The optical quality of rainbow
trout lenses was significantly reduced following creosote exposure, as indicated
by increased FLV. Lens damage was significantly related to hepatic EROD activity,
and both effects rose with creosote dose. Analytical measurements of microcosm
water indicated elevated concentrations of PAHs in creosote-dosed ponds,
including compounds capable of inducing rainbow trout EROD activity in vitro.
Hepatic concentrations of PAHs were low and not related to creosote dose, likely
due to rapid metabolism and elimination. This study demonstrates for the first
time employment of a highly sensitive and quantitative technique to measure lens
damage in fish exposed to contaminants in situ. The relationship between this
effect and hepatic CYP1A activity may suggest a mechanistic linkage, which could
lead to the use of EROD activity as an indicator of toxic effect rather than just
chemical exposure.
PMID- 10667934
TI - Effects of chronic dietary cadmium on hepatic glutathione levels and glutathione
peroxidase activity in starlings (Sturnus vulgaris).
AB - The effects of chronic exposure to dietary cadmium on the levels of hepatic
glutathione (GSH) and on the activity of the glutathione peroxidase enzymes (GSH
Px) were studied for the first time in starlings (Sturnus vulgaris). Thirty-three
individuals (17 females and 16 males) were divided into three groups: One
represented the untreated control and two were respectively fed with diets
containing 10 and 50 ppm cadmium chloride (CdCl(2)). The total duration of
treatment was 22 weeks. The three groups respectively accumulated mean hepatic Cd
residues of 2.29, 75.71, and 208.49 ppm. Hepatic GSH increased in the treated
groups respectively 24% and 52% in comparison to controls. Total GSH-Px activity
in the liver was inhibited in the group fed with 50 ppm, due to inhibition of the
selenium-dependent fraction of the enzyme, while the selenium-independent
fraction did not change significantly. During the treatment, after 14 weeks of
exposure to cadmium, the 50 ppm-treated group showed a 47% decrease of the
activity of the selenium-dependent GSH-Px and a 50% increase of the somatic liver
index in comparison with controls.
PMID- 10667935
TI - Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls
(PCBs), and organochlorine pesticides in yellow-blotched map turtle from the
Pascagoula River basin, Mississippi, USA.
AB - Concentrations of polychlorinated-dibenzo-p-dioxins (PCDDs), -dibenzofurans
(PCDFs), -biphenyls (PCBs), and organochlorine pesticides were measured in
tissues of map turtles collected from two locations in the Pascagoula River
drainage of Mississippi, USA. PCBs were most predominant among the
organochlorines with a concentration of up to 99 ng/g, wet weight (580 ng/g,
lipid weight) in livers. The greatest concentration of PCDDs/DFs of 1.1 pg/g, wet
weight (15.76 pg/g, lipid weight) was found in the liver of a male turtle. The
measured concentrations of organochlorines were less than those reported for
turtles from the Great Lakes Basin and upper St. Lawrence River. PCBs contributed
90-99% of the total estimated 2, 3,7,8-tetrachlorodibenzo-p-dioxin equivalents
(TEQs). Particularly, PCB congeners 105, 118, and 156 accounted for 68-80% of the
estimated toxic potency of PCBs in turtles.
PMID- 10667936
TI - Minimal endocrine alterations in rodents after consumption of lake trout
(Salvelinus namaycush).
AB - Polychlorinated biphenyls (PCBs) and dioxins are known to cause disruptions in
circulating hormone concentrations, which may influence fertility and normal
fetal development. Structure activity relationships have been determined for
individual congeners, but it is unclear what impacts occur due to exposure to
complex mixtures of chemicals found in the environment. Most laboratory studies
of PCB exposure have used commercial mixtures in high doses, which may not be
representative of environmental concentrations of individual congeners, nor
accurately represent complex interactions of multiple contaminants. The present
study investigated endocrine alterations in rats associated with the consumption
of lake trout collected from three specific locations in the Great Lakes.
Composite fish samples were analyzed for PCBs, organochlorines, and mercury and
ranged from 415 ppb to 1,275 ppb for individual contaminants. Fillet composites
were fed to timed-pregnant Long-Evans rats as 30% of their diet. Concentrations
of total thyroxine and estrogen were not significantly different in offspring of
dosed dams from that of controls. However, aromatase activity was lowered in all
dosed groups as compared with controls. This may represent a lowered expression
of the CYP 19 gene in exposed rats or may be due to the presence of one or more
substances in the contaminants that are capable of altering the affinity of the
aromatase enzyme for its normal endogenous substrate. It is also possible that
the number of maturing follicles in the lake trout-fed rats may be fewer than
controls, which would result in an overall reduction in the enzyme activity. Data
regarding the endocrine effects of environmental contaminant mixtures found in
fish from the Great Lakes Basin are still controversial. Additionally,
information is scarce with respect to the F1 generation of laboratory animals
following environmental maternal exposures, therefore, we investigated the
reproductive-endocrine alterations in rat offspring associated with the
consumption of lake trout (Salvelinus namaycush) collected from three areas in
the Great Lakes.
PMID- 10667937
TI - Exposure of the U.S. population aged 6 years and older to cadmium: 1988-1994.
AB - Cadmium was measured in urine specimens from 22,162 participants in the Third
National Health and Nutrition Examination Survey (NHANES III 1988-1994). Urine
cadmium, expressed either as uncorrected (microg/L) or creatinine corrected
(microg/g creatinine) increased with age and with smoking. The arithmetic mean
value for urine cadmium in the U.S. population was 0.57 microg/L or 0.48 microg/g
creatinine. Based on our estimates, about 2.3% of the U.S. population have urine
cadmium concentrations greater than 2 microg/g creatinine, and 0.2% have
concentrations greater than 5 microg/g creatinine, the current World Health
Organization health-based exposure limit.
PMID- 10667938
TI - Normal values for arsenic and selenium concentrations in human lung tissue.
AB - Normal values and ranges were determined for arsenic and selenium concentrations
in lung and hilus tissue. The study group consisted of 50 deceased persons, who
were examined by autopsy at the Institute for Pathology of the University of
Erlangen-Nuremberg. Taking into consideration topographic-anatomical criteria,
samples were taken of each lung lobe and the hilar lymph nodes. The dried tissue
was analyzed using by means of hydride atomic absorption spectrometry after wet
oxidative digestion. Normal values ranged for the arsenic concentrations from <1
74 ng/g dry weight and for the selenium concentrations from <3-574 ng/g dry
weight. Arsenic was found to accumulate in the hilus tissue, whereas selenium did
not. Considerable intraindividual and interindividual variation was found for
both arsenic and selenium. There were no statistically significant differences
regarding age, smoking habits, and lung diseases. Lung tissue samples from three
deceased persons from Houston, Texas, contained lower arsenic concentrations and
somewhat higher levels of selenium compared to the German autopsies; these levels
were, however, still within the indicated normal ranges. The following
conclusions can be drawn from the results available at present: Intraindividual
and interindividual variation is high for the arsenic and selenium concentrations
in human lung tissue, so that only relatively wide normal ranges can be given for
the general population. Smoking habits, age, and lung diseases do not seem to
affect the indicated normal ranges. Postmortem determination of arsenic and
selenium concentrations in human lung tissue can provide important information on
former occupational or environmental exposure.
PMID- 10667939
TI - Herbicide spray drift odor: measurement and toxicological significance.
AB - The toxicological significance of exposure of members of the public to spray
drift odors of four herbicide formulations (three 2, 4-dichlorophenoxyacetic [2,4
D] acid derivatives and one MCPA [4-methyl-2-chlorophenoxyacetic acid]
derivative) has been studied using a combination of novel odor measurement and
classic residue analysis techniques. The mean odor concentrations, generated
during the spraying of the commercial herbicide formulations under simulated
aerial application conditions, were about twofold higher for 2,4-D ethylhexyl
ester (22,500 OU(c)/m(3)) and MCPA (30,100 OU(c)/m(3)) than for 2,4-D butyl ester
(12,400 OU(c)/m(3)) and 2,4-D amine (11,800 OU(c)/m(3)). Detailed investigations
determined that the odors are due to trace manufacturing impurities and additives
in the commercial formulations, whereas the herbicide active ingredients are
odorless. Measured airborne herbicide active ingredient concentrations under the
simulated aerial application conditions were all below their respective
occupational safety and health TLV-TWA values, indicating that exposures of
toxicological significance as a result of spray drift are unlikely.
PMID- 10667940
TI - Captan fungicide exposures of strawberry harvesters using THPI as a urinary
biomarker.
AB - Clothing affords harvesters considerable protection against the elements and can
retain substantial amounts of pesticide residue from treated crops. Normal work
clothing of female harvesters was supplemented with rubber latex gloves and
facial scarves to determine whether those measures reduced exposure. Captan
fungicide exposures in female strawberry harvesters were assessed by determining
urine clearance rates of tetrahydrophalimide (THPI). Clean rubber gloves were
supplied to the 41 harvesters for the 3 days of the study period in October 1995.
The workers were divided into two groups consisting of either bare-handed or
gloved workers, and 24-h urine specimens were collected each day. Female
harvesters who worked bare-handed cleared 5.3 microg captan equivalents as THPI
with a range of 0.4 to 13.8 microg/person/day. Harvesters who worked wearing
rubber latex gloves cleared only 2.0 microg captan equivalents with a range of
0.9 to 4.3 microg/person/day. In this case clean rubber latex gloves reduced
absorbed dose by 38%, compared to the dose absorbed by bare-handed workers. These
results additionally indicate that when a pesticide is avidly retained by rubber
latex gloves and not readily absorbed dermally as captan, estimates of absorbed
dose based on passive dosimetry data may be less reliable than exposure estimates
derived from urine biomonitoring.
PMID- 10667941
TI - PROFILE: Chemical Warfare Materiel: Unique Regulatory Issues.
AB - / The US Army manages an extensive program of environmental restoration that is
carried out primarily under authority of the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA), which establishes response
authority for cleanup of inactive waste sites. The Resource Conservation and
Recovery Act (RCRA) regulates the management and cleanup of hazardous materials
at active hazardous waste facilities. Based on the definitions found in these
acts, and corresponding promulgated regulations, environmental media contaminated
with chemical warfare materiel (CWM) can be regulated as CERCLA "pollutants or
contaminants" but do not appear to be regulated either as CERCLA hazardous
substances or RCRA hazardous wastes.In those states that have not included CWM as
hazardous materials in their RCRA programs, the RCRA requirements for management
of hazardous waste would not strictly apply to any of the CWM. The Army has
historically implemented procedures requiring that chemical warfare agents be
managed as RCRA hazardous waste regardless of the concentration, physical form,
or configuration of the agent. Such application of strict hazardous waste
requirements to management of potentially nonhazardous CWM can result in remedial
costs well out of proportion to potential human health and environmental
benefits. Recent development of chronic toxicity values for the CWM has opened
the door for development of cleanup and waste management standards for waste
streams or media containing small residual amounts of CWM. Implementation of this
health-based approach to management of CWM remediation wastes may, in part, help
to reduce potentially unnecessary hazardous waste management costs for the
nonhazardous CWM.
PMID- 10667942
TI - Environmental Indicators of Habitat Quality in a Migratory Freshwater Fish Fauna.
AB - / In general, diadromous (and particularly amphidromous and catadromous)
freshwater fishes decline in frequency of occurrence, change age/size structure,
and probably also decline in abundance with increasing elevation and distance
upstream from the sea. In freshwater fish faunas with a high proportion of
migratory species, as in New Zealand, these changes in occurrence and abundance
result in a breakdown of the relationship between fish abundance and habitat
quality, making application of the index of biotic integrity (IBI) as a measure
of habitat quality problematical since the index depends on the relationship
between population metrics and habitat quality. An alternative approach
applicable to assessing temporal changes in habitat quality and that uses a large
database on fish distributions, involves analysis of the distribution of species
across their natural distributions. In this paper we generate curves of
occurrence of species across ranges of altitude and distance inland and show,
through comparisons of data subsets, that the curves are consistent estimators of
species' occurrence and therefore useful as indicators of habitat quality.
PMID- 10667943
TI - Air Pollution Potential: Regional Study in Argentina.
AB - / Air pollution potential is a measure of the atmospheric conditions that are
unable to transport and dilute pollutants into the air, independently of the
existence of sources. This potential can be determined from two atmospheric
parameters: mixing height and transport wind. In this paper a statistical
analysis of the mixing height and transport wind, in order to determine the areas
with high or poor atmospheric ventilation in Argentina, is presented. In order to
achieve this, meteorological data registered during 1979-1982 at eight
meteorological stations were used. Daily values of the maximum mixing height were
calculated from observations of daily temperatures at different heights and
maximum surface temperature. At the same time as the maximum mixing height, the
values of the transport wind were determined from the surface windspeed and the
characteristics of the ground in the surroundings of each meteorological station.
The mean seasonal values for both parameters were obtained. Isopleths of the mean
seasonal of the maximum mixing heights were drawn. The percentage of seasonal
frequencies of poor ventilation conditions were calculated and the frequency
isopleths were also drawn to determine areas with minor and major relative
frequencies. It was found that the northeastern and central-eastern regions of
Argentina had a high air pollution potential during the whole year. Unfavorable
atmospheric ventilation conditions were also found in the central-western side of
the country during the cold seasons (37.5% in autumn and 56.9% in winter). The
region with the greatest atmospheric ventilation is located south of 40 degrees
S, where the frequency of poor ventilation varies between 8.0% in summer and
10.8% in winter.
PMID- 10667944
TI - RESEARCH: Ecological Information System: Analyzing the Communication and
Utilization of Scientific Information in Mexico.
AB - / This study is concerned with the role that communication can play in
facilitating the utilization of ecological information by different sectors of
society involved in environmental decision-making. The ecological information
system is used as a conceptual framework. This system is a model for the analysis
of interactions between three sectors involved in the management of natural
resources: researchers in ecology, change agents, and rural producers. Two case
studies of organizations carrying out scientific research aimed at finding and
implementing sustainable strategies of resource management were carried out. The
purpose was to examine how real situations function in terms of communication
strategies and to analyze such situations in relation to the model proposed. The
analysis revealed the importance of promoting the feedback of information from
change agents and rural producers to the research sector and the incorporation of
this information into the research process. It also emphasized the relevance of
having "active utilizer constituencies" within the rural producers who make
demands upon the entire system in order to satisfy information needs. The
creation of linkage systems facilitating the connection between the generation
and utilization of information was supported. In particular, the establishment of
special teams within research institutions is proposed, which could promote the
links between the sectors through the use of communication as an instrument of
work.
PMID- 10667945
TI - Sustainable Farming Practices: Ghanaian Farmers' Perception of Erosion and Their
Use of Conservation Measures.
AB - / Soil erosion in Africa has been in the limelight over the last two decades with
researchers and policy-makers calling for sustainable farming practices. This is
often based on the assumption that farmers have a poor perception and little
knowledge about soil erosion and conservation measures and completely ignores the
realities of the Africanenvironment and the socioeconomic constraints farmers are
faced with. This paper investigates the way farmers in northern Ghana perceive
soil erosion and their rationality when it comes to their choice of conservation
measures, and the question is asked whether the existing farming practices can be
considered sustainable. Based on this study it appears that farmers have a clear
perception of the problem and adopt a wide range of conservation measures,
depending on the availability of stones and grasses, possible side effects
associated with using these measures, as well as the time spent on establishing
and maintaining them. This study shows that when trying to find solutions to soil
erosion problems, both the physical and socioeconomic realities of the
environment have to be considered.
PMID- 10667946
TI - Toward an Understanding of Norm Prevalence: A Comparative Analysis of 20 Years of
Research.
AB - / Norms are defined as evaluative standards regarding individual behavior or
conditions in a given context. They define what behavior should be, rather than
actual behavior. Norm prevalence refers to the proportion of individuals in a
population who can articulate a norm in a given evaluation context. This paper
empirically examines the prevalence of encounter norms in 56 evaluation contexts.
Data for this comparative analysis were obtained from 30 studies that used a
single-item question asking recreationists to indicate the highest number of
encounters they would tolerate before the experience changed. Four predictor
variables were examined: (1) type of resource, (2) type of activity, (3) type of
encounter, and (4) question response format. As anticipated, norm prevalence
varied by type of resource (backcountry or frontcountry), type of encounter (no
conflict versus conflict), and question response format (two-category implicit,
two-category explicit, and three-category). These three independent variables
explained 64% of the variance in norm prevalence. Also as hypothesized, there was
no relationship between type of activity (consumptive or nonconsumptive) and norm
prevalence. Implications for future research and management are discussed; it is
argued that prevalence is an important characteristic of social norms.
PMID- 10667947
TI - Variation in Sensitivity of Aquatic Species to Toxicants: Practical Consequences
for Effect Assessment of Chemical Substances.
AB - / This study addresses the relation between the sensitivity of aquatic species
and mode of action of different classes of organic chemicals. We analyzed large
data sets of ecotoxicological information to reveal the interspecies variation in
sensitivity, to relate this variation to the compounds' mode of action, and to
explain the observed patterns using general biological information. Here we
present a general framework and recommendations for risk assessment procedures.
We recommend the use of toxicologically based classification schemes at an early
stage of the risk assessment procedure. Screening programs are most efficiently
run when only one species per compound is tested to prioritize substances. The
toxicity of compounds belonging to the class of nonpolar narcotics is highly
predictable and shows little interspecies variation. For these compounds
quantitative structure-activity relationships (QSARs) can be used to estimate
effect levels. Most effort should be put into testing reactive compounds and
compounds with a specific mode of action as toxicity to some species can be 10(5)
10(6) times higher compared with less sensitive species. The use of assessment
factors in effect assessment procedures may lead to an underestimation of effects
on the more sensitive species.For many priority pollutants there is little
information on their ecotoxicity. Predictive techniques are needed to compensate
for this lack of data. Knowledge of the relation between modes of action of
compounds and interspecies variation in sensitivity should be integrated in risk
assessment procedures in order to make more efficient use of the limited
financial resources available.
PMID- 10667948
TI - Toward an Integrated Classification of Ecosystems: Defining Opportunities for
Managing Fish and Forest Health.
AB - / Many of the aquatic and terrestrial ecosystems of the Pacific Northwest United
States have been simplified and degraded in part through past land-management
activities. Recent listings of fishes under the Endangered Species Act and major
new initiatives for the restoration of forest health have precipitated
contentious debate among managers and conservation interests in the region.
Because aggressive management activities proposed for forest restoration may
directly affect watershed processes and functions, the goals of aquatic and
terrestrial conservation and restoration are generally viewed as in conflict. The
inextricable links in ecological processes and functions, however, suggest the
two perspectives should really represent elements of the same problem; that of
conserving and restoring more functional landscapes. We used recent information
on the status and distribution of forest and fish communities to classify river
subbasins across the region and explore the potential conflict and opportunity
for a more integrated view of management. Our classification indicated that there
are often common trends in terrestrial and aquatic communities that highlight
areas of potential convergence in management goals. Regions where patterns
diverge may emphasize the need for particular care and investment in detailed
risk analyses. Our spatially explicit classification of subbasin conditions
provides a mechanism for progress in three areas that we think is necessary for a
more integrated approach to management: (1) communication among disciplines; (2)
effective prioritization of limited conservation and restoration resources; and
(3) a framework for experimentation and demonstration of commitment and untested
restoration techniques.
PMID- 10667949
TI - ENVIRONMENTAL AUDITING: Arthropod Monitoring for Fine-Scale Habitat Analysis: A
Case Study of the El Segundo Sand Dunes.
AB - / Arthropod communities from several habitats on and adjacent to the El Segundo
dunes (Los Angeles County, CA) were sampled using pitfall and yellow pan traps to
evaluate their possible use as indicators of restoration success. Communities
were ordinated and clustered using correspondence analysis, detrended
correspondence analysis, two-way indicator species analysis, and Ward's method of
agglomerative clustering. The results showed high repeatability among replicates
within any sampling arena that permits discrimination of (1) degraded and
relatively undisturbed habitat, (2) different dune habitat types, and (3) annual
change. Canonical correspondence analysis showed a significant effect of
disturbance history on community composition that explained 5-20% of the
variation. Replicates of pitfall and yellow pan traps on single sites clustered
together reliably when species abundance was considered, whereas clusters using
only species incidence did not group replicates as consistently. The broad
taxonomic approach seems appropriate for habitat evaluation and monitoring of
restoration projects as an alternative to assessments geared to single species or
even single families.
PMID- 10667950
TI - Monitoring Diffuse Impacts: Australian Tourism Developments.
AB - / The scientific quality of monitoring for diffuse environmental impacts has
rarely been quantified. This paper presents an analysis of all formal
environmental monitoring programs for Australian tourism developments over a 15
year period from 1980 to 1995. The tourism sector provides a good test bed for
this study because tourism developments are (1) often adjacent to or even within
conservation reserves and other relatively undisturbed natural environments, and
(2) often clustered, with resulting cumulative impacts that require detection at
an early stage. Here we analyze the precision and reliability with which
monitoring programs as actually implemented can detect diffuse environmental
impacts against natural variation. Of 175 Australian tourism developments subject
to EIA from 1980 to 1993 inclusive, only 13 were subject to formal monitoring.
Only 44 individual parameters, in total, were monitored for all these
developments together. No baseline monitoring was conducted for nine of the 44
parameters. For the remaining 35, only one was monitored for a full year. Before,
after, control, impact, paired sampling (BACIP) monitoring designs were used for
24 of the 44 parameters, and power analysis in 10. The scientific quality of
monitoring was significantly better for developments subject to control by the
Great Barrier Reef Marine Park Authority (GBRMPA). The key factor appears to be
the way in which GBRMPA uses external referees and manages external consultants.
The GBRMPA model merits wider adoption.
PMID- 10667955
TI - Seizure--into the new millennium.
PMID- 10667957
TI - Conference abstracts: the epilepsy and pregnancy group. manchester, 1999
PMID- 10667956
TI - Epilepsy, the mother and the child: a personal perspective.
PMID- 10667958
TI - Epilepsy in ancient Greek medicine--the vital step.
PMID- 10667959
TI - Epilepsy and the family: a review of current literature.
AB - Although the negative effect of epilepsy on patient's psychosocial well-being has
been increasingly documented in the last decade, the influence of the condition
on the family has attracted much less interest. This paper reviews the present
state of family research, examining the influence of both childhood and adulthood
epilepsy on the psychological and social well-being of family members. Studies
indicate that epilepsy may cause high levels of psychosocial difficulties for all
family members, including stigmatization, stress, psychiatric morbidity, marital
problems, poor self esteem and restriction of social activities. Studies also
suggest that the family environment may be an important intervening factor
between the condition and the outcome for the family unit, and a number of family
factors are reviewed which have been suggested to mediate this relationship, with
recommendations being made for their use in intervention studies. Shortcomings of
the family studies to date are discussed and these include: concentration on
examination of issues around family life, studies being based on reports from
single members of the family and the selection of subjects from clinical
populations. Recommendations are made concerning methodological and conceptual
issues that need addressing for future research.
PMID- 10667960
TI - General-practice-based nurse specialists-taking a lead in improving the care of
people with epilepsy.
AB - Epilepsy is almost as common as diabetes and some 750 people with epilepsy die
suddenly and prematurely each year. Unfortunately, the management of epilepsy has
been much neglected and services often remain fragmented and difficult for
patients to understand. We employed a nurse specialist in epilepsy to work with
practice nurses in a group of general practices to promote better care, to make
patients aware of sources of help and support, and to provide information about
issues such as driving, employment and pregnancy. Over 70% of patients with
epilepsy attended 'clinics' run by the specialist nurse and many previously
unidentified problems were successfully resolved-including misdiagnosis, over
medication and lack of awareness of the side-effects of antiepileptic drugs.
Nurse specialists in epilepsy, working with groups of general practices but in
collaboration with hospital specialists and voluntary organizations, can take a
lead role in facilitating joint working between all those involved in service
provision, in training practice nurses and others in the special needs of people
with epilepsy and in providing support in hospital clinics.
PMID- 10667961
TI - Improving the epilepsy service: the role of the specialist nurse.
AB - There is currently a wide variation in the level of service provided for patients
with epilepsy across the UK. Evidence is becoming available to suggest that
improvements in local service provision may be achieved through the intervention
of a specialist nurse. Using practical examples, this article explores the roles
of the epilepsy specialist nurse, and examines how they may benefit patients and
improve services. Functions such as liaison, patient assessment and management,
counselling, provision of information, education, and audit are considered. It is
hoped that the improved co-ordination and management of epilepsy services, that
is achieved through specialist nurse intervention, will lead to improved patient
outcomes and increased cost-effectiveness.
PMID- 10667962
TI - The effect of specially trained epilepsy nurses in primary care: a review.
AB - The paper describes the evidence on potential effects of specially trained nurses
working in primary care for patients with epilepsy. The method used was a search
and review of evidence published from 1992 to 1999. It was found that where
nurses have been trained in epilepsy care, there is good evidence that it is
feasible for them to set up and run clinics in family practice. Where this has
been undertaken, there is level I evidence that this is acceptable and
satisfactory to patients. Where clinics have been set up in primary care, there
is level I evidence that there has been an increase in the information and advice
recorded as being provided to patients. Structured checklists may additionally
prompt service providers to increase the level of information provided to
patients, and this hypothesis is being tested currently. In conclusion, epilepsy
nurses can set up clinics for patients in primary care which are well attended,
satisfy patients, and which are associated with better recording of advice given.
There is little published evidence on outcome as opposed to process measures.
Trials with adequate sample size and long-term follow-up are necessary to
identify whether nurse monitoring with advice and counselling can benefit
patients in terms of epilepsy self-management in the long run.
PMID- 10667963
TI - Conversion from thrice daily to twice daily administration of gabapentin (GBP) in
partial epilepsy: analysis of clinical efficacy and plasma levels.
AB - Gabapentin has been administered in placebo-controlled studies with a thrice
daily (T.I.D.) schedule, because of its short half-life. However, clinical
efficacy does not seem strictly related to plasma levels: a twice daily (B.I.D.)
schedule might therefore be possible. The aim of our study was to verify if the
conversion from a T.I.D. to a B.I.D. regimen affected the efficacy and safety of
gabapentin therapy. Out of 171 patients treated with add-on gabapentin, we
selected 29 stable responders, who were followed for three months with a T.I.D.
schedule and then switched to B.I.D. regimen for further three months. Seizure
number, side-effects and trough plasma levels of gabapentin were collected during
both periods. Gabapentin mean dose was 2117.2 mg/day. Mean number of
seizures/months was: 4.2 at baseline, 1.0 during the T.I.D., and 0.9 during the
B.I.D. period. Mean trough plasma level of gabapentin was 5.9 microgram/ml during
the T.I.D. and 5.2 microgram/ml during the B.I.D. period. Twelve side-effects
were reported by 11 patients during the T.I.D. and 6 by 5 patients during the
B.I.D. period., sedation and vertigo were the most frequent in both. Results of
our study suggest that gabapentin can be administered safely and effectively
either with a T.I.D. and a B.I.D. regimen.
PMID- 10667964
TI - Refractory epilepsy: treatment with new antiepileptic drugs.
AB - Five antiepileptic drugs have been marketed in the last decade. We report here a
retrospective study of patients attending our unit who were prescribed one of the
new antiepileptic drugs. All these patients had refractory localization related
epilepsy and had failed to respond to a first-line drug. The drugs had a
different profile of side-effects but topiramate (42%) was the most common drug
to be withdrawn due to side-effects as compared with tiagabine (26%), vigabatrin
(16%), gabapentin (16%), and lamotrigine (15%). With regard to efficacy, 31% of
the patients receiving gabapentin had a greater than 50% reduction in seizures
compared with lamotrigine (25%), topiramate (20%), vigabatrin (19%) and tiagabine
(11%). The number of patients remaining seizure free with gabapentin was 8%
whilst for lamotrigine this was 5%, vigabatrin 5%, topiramate 1% and tiagabine
4%. In conclusion, all these five antiepileptic drugs are useful in treating
refractory localization related epilepsy.
PMID- 10667965
TI - Aggressive behaviour at a residential epilepsy centre.
AB - There is an extensive literature on epilepsy and violence, but no study has
addressed aggression (i.e. apparently intentional violence) in a residential-care
population. We performed a retrospective study at the Chalfont Centre for
Epilepsy (a residential-care facility in rural Buckinghamshire) in order to
determine the frequency and character of episodes of aggression. This allowed us
to identify a group of aggressive subjects who were compared with age- and sex
matched control subjects drawn from the remaining residents. We found the
prevalence of aggression to be 27.2% in 1 year amongst long-term residents. The
overall frequency was estimated at between 121 and 207 incidents per 100 persons
per year. A few incidents (0.7%) were related to an acute psychosis but they were
more likely to result in significant injury. Offenders were younger than non
aggressive residents. Gender, age of onset of epilepsy, history of psychosis,
mobility, abnormality on MRI scan, learning disability and seizure frequency were
not associated with aggressive conduct.
PMID- 10667966
TI - Psychotic episodes during zonisamide treatment.
AB - Several articles have appeared over the last years devoted to mental side effects
during zonisamide (ZNS) treatment. In this study, we were particularly interested
in psychotic episodes. Seventy-four epileptic patients with a history of ZNS
treatment were surveyed retrospectively over the period spanning 1 March 1984 to
30 June 1994. They were divided into two groups according to the presence or
absence of psychotic episodes during ZNS treatment. We analysed various factors
pertaining to psychotic episodes during ZNS treatment. Of the 74 patients 14 had
psychotic episodes. We found that the incidence of psychotic episodes during ZNS
treatment was several times higher than the previously reported prevalence of
epileptic psychosis, and that the risk of psychotic episodes was higher in young
patients. In 13 patients, psychotic episodes occurred within a few years of
commencement of ZNS. In children, obsessive-compulsive symptoms appeared to be
related to psychotic episodes. It is important to terminate ZNS as soon as
possible if psychotic episodes develop and never restart, even if seizures become
worse. It cannot definitely be proved that ZNS causes psychotic episodes, as
information on mental side effects during ZNS monotherapy is scant, but it does
appear likely that ZNS contributes to psychotic episodes during polytherapy.
PMID- 10667967
TI - The molecular biology of invertebrate voltage-gated Ca(2+) channels.
AB - The importance of voltage-gated Ca(2+) channels in cellular function is
illustrated by the many distinct types of Ca(2+) currents found in vertebrate
tissues, a variety that is generated in part by numerous genes encoding Ca(2+)
channel subunits. The degree to which this genetic diversity is shared by
invertebrates has only recently become apparent. Cloning of Ca(2+) channel
subunits from various invertebrate species, combined with the wealth of
information from the Caenorhabditis elegans genome, has clarified the
organization and evolution of metazoan Ca(2+) channel genes. Functional studies
have employed novel structural information gained from invertebrate Ca(2+)
channels to complement ongoing research on mammalian Ca(2+) currents, while
demonstrating that the strict correspondence between pharmacological and
molecular classes of vertebrate Ca(2+) channels does not fully extend to
invertebrate tissues. Molecular structures can now be combined with physiological
data to develop a more cogent system of categorizing invertebrate channel
subtypes. In this review, we examine recent progress in the characterization of
invertebrate Ca(2+) channel genes and its relevance to the diversity of
invertebrate Ca(2+) currents.
PMID- 10667968
TI - Pinpointing food sources: olfactory and anemotactic orientation in desert ants,
Cataglyphis fortis.
AB - Desert ants, Cataglyphis fortis, search for a repeatedly visited food source by
employing a combined olfactory and anemotactic orientation strategy (in addition
to their visually based path-integration scheme). This behaviour was investigated
by video-tracking consecutive foraging trips of individually marked ants under a
variety of experimental conditions, including manipulations of the olfactory and
wind-detecting systems of the ants. If the wind blows from a constant direction,
ants familiar with the feeding site follow outbound paths that lead them into an
area 0.5-2.5 m downwind of the feeding station. Here, the ants apparently pick up
odour plumes emanating from the food source and follow these by steering an
upwind course until they reach the feeder. If the food is removed, foragers
usually concentrate their search movements within the area downwind of the
feeding site. Only when the wind happens to subside or when tail-wind conditions
prevail do the ants steer direct courses towards the food. Elimination of
olfactory input by clipping the antennal flagella, or of wind perception by
immobilising the bases of the antennae, altered the foraging behaviour of the
ants in ways that supported these interpretations. Ants with clipped flagella
were never observed to collect food items.
PMID- 10667969
TI - Energy storage by passive elastic structures in the mantle of sepia officinalis.
AB - The passive elastic properties of the mantle of the cuttlefish Sepia officinalis
have been characterized in experiments on intact mantle and on pieces cut from
the mantle. The mantle was found to be very compliant over a wide range of
circumferential strains, corresponding to a change in mantle circumferential
strain of 0.45. Beyond this range of strain, the mantle was much stiffer, in both
the circumferential direction, 0.542+/-0.025 MPa (mean +/- s.e.m., N=51) and
through the thickness of the mantle wall, 0.152+/-0.041 MPa (N=11). Almost 80 %
of the work done on the tissue during compression in the circumferential
direction was recovered during elastic recoil of the tissue; this elastic work
could contribute to refilling the mantle after a jet. Our estimates of the work
done during a cycle of jetting and refilling show that such elastic work is small
(approximately 1 %) compared with the contractile work done by the circular
muscle fibres. However, although the elastic work is almost negligible in the
overall energy budget, it is probably sufficient to power refilling of the
mantle.
PMID- 10667970
TI - Effect of wind and solar radiation on metabolic heat production in a small desert
rodent, Spermophilus tereticaudus.
AB - To understand better how complex interactions between environmental variables
affect the energy balance of small diurnal animals, we studied the effects of the
absence and presence of 950 W m(-)(2) simulated solar radiation combined with
wind speeds ranging from 0. 25 to 1.00 m s(-)(1) on the metabolic rate and body
temperature of the round-tailed ground squirrel Spermophilus tereticaudus. As
wind speed increased from 0.25 to 1.00 m s(-)(1), metabolic heat production
increased by 0.94 W in the absence of solar radiation and by 0.98 W in the
presence of 950 W m(-)(2) simulated solar radiation. Exposure to simulated solar
radiation reduced metabolic heat production by 0.68 W at a wind speed of 0.25 m
s(-)(1), by 0.64 W at 0.50 m s(-)(1) and by 0.64 W at 1.00 m s(-)(1). Body
temperature was significantly affected by environmental conditions, ranging from
32. 5 degrees C at a wind speed of 1.0 m s(-)(1) and no irradiance to 35. 6
degrees C at a wind speed of 0.50 m s(-)(1) with 950 W m(-)(2 )short-wave
irradiance. In addition, several unusual findings resulted from this study. The
coat of S. tereticaudus is very sparse, and the observed heat transfer of 5.68+/
0.37 W m(-)(2 ) degrees C(-)(1) (mean +/- s.e.m., N=11) is much higher than
expected from either allometric equations or comparative studies with other
rodents of similar mass. Solar heat gain was remarkably low, equalling only 10 %
of intercepted radiation and suggesting a remarkably high regional thermal
resistance at the tissue level. Animals remained normally active and alert at
body temperatures as low as 32.5 degrees C. These findings suggest a unique
combination of adaptations that allow S. tereticaudus to exploit a harsh desert
environment.
PMID- 10667971
TI - Sun-compass orientation in homing pigeons: compensation for different rates of
change in azimuth?
AB - Birds using their sun compass must compensate for the apparent movement of the
sun with the help of their internal clock. The movement of the sun is not
uniform, being much faster around noon than near sunrise and sunset. If the sun
compass mechanisms are not adjusted to these variations, considerable errors
might arise. To learn whether birds are able to take the different rates of sun
azimuth change into account, we subjected homing pigeons to a 4 h fast clock
shift. The experiments were performed near Auckland, New Zealand, at a latitude
of 37 degrees S, where the expected deflections for a 4 h shift in summer vary
from less than 40 degrees to more than 120 degrees, depending on time of day. One
group of birds was released just after sunrise or during the corresponding period
in the afternoon when the expected deflections were minimal, the other group
during late morning when they were maximal. The different sizes of the observed
deflections - between 26 degrees and 51 degrees in the first group, and between
107 degrees and 153 degrees in the second group - clearly show that the birds'
compensation mechanisms are closely tuned to the varying rates of change in sun
azimuth. The results suggest that pigeons have a rather precise internal
representation of the sun curve, which makes the avian sun compass a highly
accurate mechanism of direction finding.
PMID- 10667972
TI - Continuous measurements of instantaneous heart rate and its fluctuations before
and after hatching in chickens.
AB - There has been considerable interest in heart rate (fh) fluctuations in relation
to cardiovascular control systems and foetal conditions during pregnancy in
mammals. Prominent fluctuations in fh also occur in avian embryos, which are an
important experimental model for studying developmental physiology. The present
study determined the instantaneous fh of seven chick embryos continuously from
the last stage of prenatal development (day 18), throughout the pipping
(perinatal) period (days 19-21) until hatching and, subsequently, of newly
hatched chicks (up to day 2). The distinctive patterns of instantaneous fh
fluctuations took the form of specific changes within a broad mean fh baseline.
Cyclic oscillations (ultradian rhythm) occurred until an early stage of the
perinatal period, when the fh baseline started rising. Subsequently, the baseline
dropped and respiratory arrhythmia began to appear concomitant with external
pipping. During the final stage of external pipping, when the fh baseline rose
again prior to hatching, three unique patterns of instantaneous fh fluctuations
were evident: relatively long-lasting cyclic small accelerations, irregular
intermittent large accelerations and short-term repeated large accelerations.
Furthermore, repeated alternate occurrences of the latter two types of
acceleration formed an additional oscillating pattern with a period of 10-15 min.
During the early period after hatching, when the fh baseline reached its maximum,
instantaneous fh changed relatively slowly accompanied by transient rapid
decelerations, probably due to augmented vagal tone. Subsequently, the mean fh
baseline dropped to its minimum, and a circadian rhythm and three types of
previously reported fh fluctuations (types I-III) appeared. Developmental
patterns of mean fh and the appearance of distinctive patterns of instantaneous
fluctuations in fh and circadian rhythms were not influenced by an ultimate
failure of hatching after a normal development. The demonstration of complex,
repeatable patterns of fh fluctuation that change during development suggests
that the avian embryo model should be useful in studying the phenomenon of fh
fluctuation and its underlying causes.
PMID- 10667973
TI - Mitochondrial function in flying honeybees (Apis mellifera): respiratory chain
enzymes and electron flow from complex III to oxygen.
AB - The biochemical bases for the high mass-specific metabolic rates of flying
insects remain poorly understood. To gain insights into mitochondrial function
during flight, metabolic rates of individual flying honeybees were measured using
respirometry, and their thoracic muscles were fixed for electron microscopy.
Mitochondrial volume densities and cristae surface densities, combined with
biochemical data concerning cytochrome content per unit mass, were used to
estimate respiratory chain enzyme densities per unit cristae surface area.
Despite the high content of respiratory enzymes per unit muscle mass, these are
accommodated by abundant mitochondria and high cristae surface densities such
that enzyme densities per unit cristae surface area are similar to those found in
mammalian muscle and liver. These results support the idea that a unit area of
mitochondrial inner membrane constitutes an invariant structural unit. Rates of
O(2) consumption per unit cristae surface area are much higher than those
estimated in mammals as a consequence of higher enzyme turnover rates (electron
transfer rates per enzyme molecule) during flight. Cytochrome c oxidase, in
particular, operates close to its maximum catalytic capacity (k(cat)). Thus, high
flux rates are achieved via (i) high respiratory enzyme content per unit muscle
mass and (ii) the operation of these enzymes at high fractional velocities.
PMID- 10667974
TI - Avian pectoral muscle size rapidly tracks body mass changes during flight,
fasting and fuelling.
AB - We used ultrasonic imaging to monitor short-term changes in the pectoral muscle
size of captive red knots Calidris canutus. Pectoral muscle thickness changed
rapidly and consistently in parallel with body mass changes caused by flight,
fasting and fuelling. Four knots flew repeatedly for 10 h periods in a wind
tunnel. Over this period, pectoral muscle thickness decreased in parallel with
the decrease in body mass. The change in pectoral muscle thickness during flight
was indistinguishable from that during periods of natural and experimental
fasting and fuelling. The body-mass-related variation in pectoral muscle
thickness between and within individuals was not related to the amount of flight,
indicating that changes in avian muscle do not require power-training as in
mammals. Our study suggests that it is possible for birds to consume and replace
their flight muscles on a time scale short enough to allow these muscles to be
used as part of the energy supply for migratory flight. The adaptive significance
of the changes in pectoral muscle mass cannot be explained by reproductive needs
since our knots were in the early winter phase of their annual cycle. Instead,
pectoral muscle mass changes may reflect (i) the breakdown of protein during
heavy exercise and its subsequent restoration, (ii) the regulation of flight
capacity to maintain optimal flight performance when body mass varies, or (iii)
the need for a particular protein:fat ratio in winter survival stores.
PMID- 10667975
TI - Sustained swimming at low velocity following a bout of exhaustive exercise
enhances metabolic recovery in rainbow trout.
AB - Sustained swimming at 0.9 BL s(-)(1), where BL is fork body length, following a
bout of exhaustive exercise enhanced recovery of metabolite and acid-base status
in rainbow trout compared with fish held in still water. The most striking effect
of an active recovery was a total absence of the elevation cortisol concentration
typically associated with exhaustive exercise. In fish swimming at 0. 9 BL s(
)(1), plasma cortisol levels averaged 20-25 ng ml(-)(1) throughout the 6 h
recovery period. In contrast, plasma cortisol increased to a peak level of
128.4+/-11.2 ng ml(-)(1) (mean +/- s.e. m., N=6) in fish recovering in still
water. Muscle glycogen was completely resynthesized and lactate cleared within 2
h of exercise in swimming fish compared with more than 6 h required in the fish
held in still water. Similarly, blood lactate level and acid-base status were
restored more quickly in the swimming fish. These observations suggest that the
prolonged recovery usually associated with exhaustive exercise in rainbow trout
is due to elevations in plasma cortisol concentration and that the stimulus for
cortisol release is not exercise per se, but rather post-exercise inactivity.
PMID- 10667976
TI - Responsiveness of olfactory neurons to distinct aliphatic aldehydes.
AB - The responsiveness of isolated olfactory sensory neurons to stimulation with
aliphatic aldehydes of varying chain length (5-10 hydrogenated carbon atoms) was
investigated by means of Ca(2+ )imaging. More than half the cells examined were
responsive to aliphatic aldehydes. Individual cells did not react or reacted to
one or multiple aldehydes; in the latter case, cells only reacted to aldehydes of
consecutive carbon chain lengths. The largest proportion of cells responded to
octanal. It was also demonstrated that a structural difference as small as one
hydrogenated carbon atom was detectable by the olfactory neurons. Neurons were
increasingly able to discriminate between two aldehydes as the difference in
chain length between the two increased. Discrimination between aldehydes with
longer carbon chains was reduced. Although the odorants examined belong to a
distinct chemical class and differ only slightly in structure, individual
olfactory sensory neurons showed quite different receptive properties.
PMID- 10667977
TI - Head-bobbing in pigeons: how stable is the hold phase?
AB - The head movement of a walking pigeon Columba livia is characterized by two
alternating phases, a thrust phase and a hold phase. While the head is rapidly
thrust forward during the thrust phase, it has been shown repeatedly that it
remains virtually motionless with respect to translation along a horizontal axis
(roll axis) during the hold phase. It has been shown that the stabilization
during the hold phase is under visual control. This has led to the view that the
pigeon's head-bobbing is an optokinetic response to stabilize the retinal image
during the hold phase. However, it has never been shown explicitly that the head
is really held stable in space with respect to other translatory or rotatory
dimensions. Using videography, we show here that this is in fact the case: except
for a small but systematic slip that presumably serves as an error signal for
retinal image stabilization, the head of the pigeon remains locked in space not
only with respect to the horizontal (roll) axis but also with respect to vertical
translation (along the yaw axis) and with respect to rotation around the pitch
and yaw axes.
PMID- 10667978
TI - Heat-shock-induced thermoprotection of hindleg motor control in the locust.
AB - Functional neuromuscular connections are critical for appropriate behavioural
responses, but can be negatively affected by increases in temperature. We
investigated the effects of heat shock on the thermosensitivity of a
neuromuscular pathway to the hindleg tibial extensor muscle of Locusta
migratoria. We found that exposure to heat shock induced thermoprotection of both
neuromuscular transmission and extensor muscle contraction by (i) increasing the
upper temperature limit for failure, (ii) improving recovery following heat
induced failure and (iii) stabilizing excitatory junction potential amplitude and
duration and extensor muscle contraction force at high temperatures. Furthermore,
the heat-shock-induced thermoprotection of extensor muscle contraction was not
attributable to a protective effect on intrinsic components of muscle
contraction. Finally, the use of jumping as a locomotor strategy to avoid
capture, a behavioural response dependent upon functionally competent
neuromuscular connections at the hindleg tibial extensor muscle, became less
sensitive to temperature following heat shock. We conclude that the natural
stress response of the locust stabilizes neuromuscular signalling during
temperature stress, and that this can underlie a thermoprotection of muscle
contraction force and thus alter the thermosensitivity of an escape behaviour
critical for survival.
PMID- 10667979
TI - Oxygen-dependent energetics of anoxia-tolerant and anoxia-intolerant hepatocytes.
AB - The oxygen-dependence of cellular energetics was investigated in hepatocytes from
goldfish Carassius auratus (anoxia-tolerant) and rainbow trout Oncorhynchus
mykiss (anoxia-intolerant). In goldfish hepatocytes, an approximately 50 %
reduction in the rate of oxygen consumption was observed in response to both
acute and prolonged hypoxia, the latter treatment shifting the threshold for this
reduction to a higher oxygen level. A concomitant increase in the rate of lactate
production did not compensate for the decreased aerobic ATP supply, resulting in
an overall metabolic depression of 26 % during acute hypoxia and of 42 % during
prolonged hypoxia. Trout hepatocytes showed a similar suppression of cellular
respiration after prolonged hypoxia but were unresponsive to acute hypoxia.
Similarly, the rate of lactate production was unaltered during acute hypoxia but
was increased during prolonged hypoxia, metabolic depression amounting to 7 %
during acute hypoxia and 30 % during prolonged hypoxia. In both species, the
affinity of hepatocytes for oxygen decreased during hypoxia, but this alteration
was not sufficient in absolute terms to account for the observed decrease in
aerobic ATP supply. Protein synthesis was suppressed in both cell types under
hypoxia, whereas Na(+)/K(+)-ATPase activity decreased in trout but not in
goldfish hepatocytes, emphasising the importance of membrane function in these
cells during conditions of limited energy supply.
PMID- 10667980
TI - Attention-dependent suppression of metabolic activity in the early stages of the
macaque visual system.
AB - In this study we used a modified double-label deoxyglucose procedure to
investigate attention-dependent modulations of deoxyglucose uptake at the
earliest stages of the macaque visual system. Specifically, we compared activity
levels evoked during two tasks with essentially identical visual stimulation
requiring different attentional demands. During a featural-attention task, the
subjects had to discriminate the orientation of a grating; during a control
spatial-attention task, they had to localize the position of a target point.
Comparison of the resulting activity maps revealed attention-dependent changes in
metabolic activity in portions of the magnocellular layers of the lateral
geniculate nucleus, and the magnocellular-recipient layers 4Calpha and 4B of the
striate cortex. In these early stages of the visual system, attention to the
orientation of the grating suppressed the metabolic activity in a retinotopically
specific band peripheral to the representation of the stimulus. These results
favor an early selection model of attention. After a thalamic attention-dependent
gating mechanism, irrelevant visual information outside the focus of attention
may be suppressed at the level of the striate cortex, which would then result in
an increased signal-to-noise ratio for the processing of the attended feature in
higher-tier, less retinotopically organized, extrastriate visual areas.
PMID- 10667981
TI - Theoretical neuroanatomy: relating anatomical and functional connectivity in
graphs and cortical connection matrices.
AB - Neuroanatomy places critical constraints on the functional connectivity of the
cerebral cortex. To analyze these constraints we have examined the relationship
between structural features of networks (expressed as graphs) and the patterns of
functional connectivity to which they give rise when implemented as dynamical
systems. We selected among structurally varying graphs using as selective
criteria a number of global information-theoretical measures that characterize
functional connectivity. We selected graphs separately for increases in measures
of entropy (capturing statistical independence of graph elements), integration
(capturing their statistical dependence) and complexity (capturing the interplay
between their functional segregation and integration). We found that dynamics
with high complexity were supported by graphs whose units were organized into
densely linked groups that were sparsely and reciprocally interconnected.
Connection matrices based on actual neuroanatomical data describing areas and
pathways of the macaque visual cortex and the cat cortex showed structural
characteristics that coincided best with those of such complex graphs, revealing
the presence of distinct but interconnected anatomical groupings of areas.
Moreover, when implemented as dynamical systems, these cortical connection
matrices generated functional connectivity with high complexity, characterized by
the presence of highly coherent functional clusters. We also found that selection
of graphs as they responded to input or produced output led to increases in the
complexity of their dynamics. We hypothesize that adaptation to rich sensory
environments and motor demands requires complex dynamics and that these dynamics
are supported by neuroanatomical motifs that are characteristic of the cerebral
cortex.
PMID- 10667982
TI - Investigation of nonlinear ECoG changes during spontaneous sleep state changes
and cortical arousal in fetal sheep.
AB - We examined the processes of cortical activation and deactivation of the fetal
brain during spontaneous sleep state transitions and during central nervous
processing of vibroacoustic stimulations (VASs) using nonlinear analysis of the
electrocorticogram (ECoG). Tests of nonlinearity and a random shuffling routine
revealed deterministic and nonlinear portions in the fetal ECoG. As common
nonlinear measures are not applicable to nonstationary time series, we developed
an algorithm to estimate the predictability of the ECoG in its time course by
means of a point prediction error (PPE). The ECoG was recorded before and during
VAS from the maternal abdominal surface in seven chronically instrumented fetal
sheep at 0.8 of gestation. The PPE during REM sleep was significantly higher than
during NREM sleep. VAS in NREM sleep resulted in an abrupt increase of the PPE
not reaching the level of REM sleep. The steep increase of the PPE at onset and
its slow decrease after cessation of the stimulus were very similar to the
dynamics of spontaneous sleep state transitions, suggesting the involvement of
the same cortical activating mechanisms. In conclusion, the stage and the time
course of fetal brain activation and deactivation patterns can be clearly shown
by PPE techniques. The PPE is a useful complement to spectral analysis. Both
techniques describe different properties of the ECoG.
PMID- 10667983
TI - The projection from V1 to extrastriate area 21a: a second patchy efferent pathway
colocalizes with the CO blob columns in cat visual cortex.
AB - The different patchy organizations of neurons projecting from primary visual
cortex (area 17) to the various extrastriate areas may contribute to functional
differences in the output to each of these areas. The pattern of neurons
projecting to extrastriate area 21a was examined using large injections of
retrograde tracers and compared to the pattern shown by neurons projecting to the
lateral suprasylvian area (LS). Patches of neurons projecting to 21a showed a
bimodal laminar distribution, with numerous labeled cells in the upper and lower
third of layer 3 bracketing a sparsely labeled central third; LS-projecting
neurons were confined to the lower and middle thirds of layer 3. The 21a
projecting cells were relatively tighter in their clustering pattern than the LS
projecting cells, i. e. the difference in labeling density between patch and
interpatch zones was greater for 21a-projecting cells than for LS-projecting
cells. As previously shown for the LS-projecting cells, patches of 21a-projecting
cells colocalized with CO blob columns in area 17. Combined with our earlier
results, this study shows that the CO blob compartments in area 17 give rise to
at least two distinct efferent pathways, one projecting to LS and the other to
21a, and furthermore suggest that each pathway may carry unique information to
its extrastriate target.
PMID- 10667984
TI - Non-uniformity of neocortex: areal heterogeneity of NADPH-diaphorase reactive
neurons in adult macaque monkeys.
AB - We have examined the distribution of cortical neurons in adult monkey cortex
which stain for nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d),
an enzyme which is involved in the synthesis of nitric oxide. In order to compare
distributions across areas we employed a cortical unit defined as the radial
column, which refers to the volume of cortex below 1 mm(2) of cortical surface.
Numbers of labeled neurons per radial column generate areal density measurements
either for the full thickness of the cortex or for individual layers.
Measurements were made in six cortical regions (areas V1, V2, STS, auditory
cortex, area 4 and area 6). NADPH-d stains nonpyramidal neurons which can be
divided into two major groups. Type 1 neurons have large soma diameters, stain
densely for NADPH-d and show few morphological variations both within and across
areas. Type 2 neurons have small somata and short processes, and can be
subdivided on the basis of soma size into dense and light staining categories.
Both subcategories of type 2 neurons show significant areal variations in size.
In each cortical area the majority of type 1 neurons are located in the white
matter. Areal densities of type 1 neurons are minimal in areas V1 and V2, and
twice as dense in the frontal cortex. Pairwise comparisons of areal densities
among the six areas examined show that in a radial column throughout the full
thickness of cortex, areas differ significantly from each other in 12/15
comparisons. Consideration of individual layers shows significant differences in
13/15 comparisons. Type 2 neurons are exclusively located in the cortical gray
matter, and in all areas are considerably more numerous than type 1 neurons. Area
V1 is unique it that it has up to three times the areal density found in any
other cortical area. With reference to published laminar cell density counts our
results show that the percentage of labeled NADPH-d neurons in individual layers
of area V1 are significantly higher than in the other areas. The laminar
distributions of type 1 and type 2 neurons show that each area has a unique
profile of NADPH-d expression. The modular or columnar organization of the
cortex, also referred to as the radial column hypothesis, is important for
understanding both the development and function of the cortex. The present
results show that radial columns in individual cortical areas possess distinctive
patterns of NADPH-d expression. This important degree of areal heterogeneity of
NADPH-d neurons has far reaching implications for both the development and
functions of neocortical areas.
PMID- 10667985
TI - Transcranial magnetic stimulation of primary motor cortex affects mental
rotation.
AB - Neuroimaging studies have shown that motor structures are activated not only
during overt motor behavior but also during tasks that require no overt motor
behavior, such as motor imagery and mental rotation. We tested the hypothesis
that activation of the primary motor cortex is needed for mental rotation by
using single- pulse transcranial magnetic stimulation (TMS). Single-pulse TMS was
delivered to the representation of the hand in left primary motor cortex while
participants performed mental rotation of pictures of hands and feet. Relative to
a peripheral magnetic stimulation control condition, response times (RTs) were
slower when TMS was delivered at 650 ms but not at 400 ms after stimulus onset.
The magnetic stimulation effect at 650 ms was larger for hands than for feet.
These findings demonstrate that (i) activation of the left primary motor cortex
has a causal role in the mental rotation of pictures of hands; (ii) this role is
stimulus-specific because disruption of neural activity in the hand area slowed
RTs for pictures of hands more than feet; and (iii) left primary motor cortex is
involved relatively late in the mental rotation process.
PMID- 10667986
TI - Serotonin depletion and barrel cortex development: impact of growth impairment
vs. serotonin effects on thalamocortical endings.
AB - Converging evidence supports a role of serotonin (5-hydroxytryptamine; 5-HT) in
barrel cortex development. Systemic administration of 5-HT-depleting drugs
reduces cross-sectional whisker barrel areas in the somatosensory cortex (SSC) of
neonatal rats. Here we assess the relative impact on barrel pattern formation of
(i) 5-HT depletion and (ii) decreased brain growth, which is often associated
with pharmacological 5-HT depletion, by comparing the effects of 5-HT-depleting
drugs with those of reduced protein intake. Left hemisphere 5-HT levels in the
SSC and right hemisphere whisker barrel areas were assessed at postnatal day 6
(P6) in the same animal following injection of p-chloroamphetamine (PCA) or p
chlorophenylalanine (PCPA) at P0. Both drugs significantly reduced cortical 5-HT
content and mean barrel areas at P6, but also body and brain growth. Differences
in brain weight accounted for 84.4% of the variance in barrel size, with
negligible contributions by cortical 5-HT content. PCPA-treated animals
sacrificed at P14 yielded similar trends, albeit less pronounced. Finally,
reduced protein intake resulted in lower body weight and cortical 5-HT levels at
P6, but yielded no change in brain weight or mean barrel area. Barrel formation
therefore appears markedly less sensitive to 5-HT depletion per se than to drug
induced growth impairment.
PMID- 10667987
TI - Localization of area prostriata and its projection to the cingulate motor cortex
in the rhesus monkey.
AB - Area prostriata is a poorly understood cortical area located in the anterior
portion of the calcarine sulcus. It has attracted interest as a separate visual
area and progenitor for the cortex of this modality. In this report we describe a
direct projection from area prostriata to the rostral cingulate motor cortex (M3)
that forms the fundus and lower bank of the anterior part of the cingulate
sulcus. Injections of retrograde tracers in M3 resulted in labeled neurons in
layers III, V and VI of prostriate cortex. However, injections of anterograde
tracers in M3 did not demonstrate axon terminals in area prostriata. This
connection was organized topographically such that the rostral part of M3
received input from the dorsal region of prostriate cortex, whereas middle and
caudal levels of M3 received input from more ventral locations. Injections of
retrograde and anterograde tracers in the caudal cingulate motor cortex (M4) did
not produce labeling in prostriate cortex. Cytoarchitectural analysis confirmed
the identity of area prostriata and further clarified its extent and borders with
the parasubiculum of the hippocampal formation rostrally, and V1 of the visual
cortex caudally. This linkage between cortex bordering V1 and cortex giving rise
to a component of the corticofacial and corticospinal pathways demonstrates a
more direct visuomotor route than visual association projections coursing
laterally.
PMID- 10667988
TI - Sniffing longer rather than stronger to maintain olfactory detection threshold.
AB - Air flow-rate is usually higher in one nostril in comparison to the other. Also,
within bounds, higher nasal flow-rate improves odorant detection. It follows from
the above that odorant detection should be better in the nostril with higher flow
rate in comparison to the nostril with lower flow-rate. Paradoxically, previous
research has shown that odorant detection thresholds are equal for the high and
low flow-rate nostrils. Here we resolve this apparent paradox by showing that
when detecting through the nostril with lower air flow-rate, humans sniffed
longer than when detecting through the nostril with higher air flow-rate, thus
equalizing performance between the nostrils. When this compensatory mechanism was
blocked, a pronounced advantage in odorant detection was seen for the nostril
with higher air flow-rate over the nostril with lower air flow-rate. Finally, we
show that normal birhinal sniff duration may enable only one nostril to reach
optimal threshold. This finding implies that during each sniff, each nostril
conveys to the brain a slightly different image of the olfactory world. It
remains to be shown how the brain combines these images into a single olfactory
percept.
PMID- 10667989
TI - The effects of sialoadenectomy and exogenous EGF on taste bud morphology and
maintenance.
AB - Taste buds on the dorsal tongue surface are continually bathed in saliva rich in
epidermal growth factor (EGF). In the following experiment, taste bud number and
morphology were monitored following submandibular and sublingual salivary gland
removal (sialoadenectomy), to determine if EGF plays a role in the maintenance
and formation of taste buds. Adult male rats were divided into four groups:
sialoadenectomized (SX, n = 4); sialoadenectomized with EGF replacement (SX +
EGF, n = 5); sham-operated (SH, n = 4); and sham-operated with exogenous EGF (SH
+ EGF, n = 5). After a 3 week recovery, SX + EGF and SH + EGF animals were given
50 microg/day EGF in their drinking water for 14 days. At day 14, saliva was
collected, the animals were killed and the presence of EGF determined by
radioligand-binding assay. Tongues were removed and histologically examined for
the presence and morphology of taste buds on fungiform and circumvallate
papillae, or immunostained for the presence of EGF, TGFalpha (transforming growth
factor alpha) and EGFR (EGF receptor). The removal of submandibular and
sublingual salivary glands resulted in the loss of fungiform taste buds and
normal fungiform papillae morphology. These effects were reversed by EGF
supplementation, indicating a role for EGF in fungiform taste bud maintenance. In
addition, supplementation of EGF to sham-operated animals increased the size of
fungiform taste buds. In contrast, removal of salivary glands had no effect on
the size, numbers, or morphology of circumvallate taste buds, suggesting that the
formation and maintenance of taste buds in fungiform and circumvallate papillae
may involve different and distinct processes. EGF, TGFalpha and EGFR were
localized to distinct layers of the dorsal epithelium and to within both
fungiform and circumvallate taste buds. Their expression within the epithelium or
taste buds was not altered with sialoadenectomy, indicating that the actions of
endogenous EGF and TGFalpha are distinct and not regulated by exogenous EGF and
TGFalpha supplied in saliva.
PMID- 10667990
TI - Olfactory discrimination of amino acids in brown bullhead catfish.
AB - Olfactory discrimination of amino acids was investigated in brown bullhead
catfish (Ameiurus nebulosus). Based on the magnitude of the observed food search
activity of catfish conditioned to single amino acids, the tested compounds were
classified as being detected by the catfish as equal to, similar to, or different
from the conditioned stimulus. L-Proline (L-Pro)-conditioned brown bullhead
catfish discriminated all amino acids from L-Pro, but catfish conditioned to L
valine (L-Val) and L-isoleucine (L-Ile) did not discriminate L-Val from L-Ile nor
L-Ile from L-Val; however, all other amino acids tested were always discriminated
from these two compounds. Catfish conditioned to L-alanine (L-Ala) discriminated
basic, acidic and several neutral amino acids with long side-chains (LCNs) from L
Ala; however, they did not always discriminate L-Ala from all neutral amino acids
with short side-chains (SCNs). The L-norleucine (L-nLeu)-conditioned fish
responded to L-norvaline (L-nVal), L-methionine (L-Met) and L-Ala similarly to L
nLeu, indicating that these amino acids are detected as similar or identical to L
nLeu. L-nLeu was, however, discriminated from L-Ala in L-Ala-conditioned catfish.
Interestingly, L-leucine (L-Leu) was discriminated from the conditioned stimuli,
L-Ala, L-Ile and L-Val, indicating independent receptors for L-Leu. Although
conditioned catfish discriminated other amino acids from L-arginine hydrochloride
(L-Arg), in some tests they were unable to discriminate L-Arg from L-lysine
hydrochloride (L-Lys). These results imply the existence of independent olfactory
receptive pathways for: (i) L-Pro; (ii) basic amino acids (L-Arg and L-Lys);
(iii) L-Leu; (iv) other neutral amino acids with branched side-chains (L-Ile and
L-Val); (v) neutral amino acids with long linear side-chains (L-nLeu, L-nVal and
L-Met); (vi) neutral amino acids with short side-chains; and (vii) amino acids
with sulfhydryl groups (L-Cys and L-homoCys).
PMID- 10667991
TI - Chemicals in laboratory room air stimulate olfactory neurons of female Bombyx
mori.
AB - Laboratory air contained odorants that elicited electrophysiological responses in
female Bombyx mori antennae. Air entrainments on charcoal filters, extracted with
CS(2) and subsequently with acetone, were analyzed by coupled gas chromatography
(GC)-electroantennogram (EAG) as well as by GC-mass spectrometry. The CS(2)
extract contained 12 EAG-active peaks from which benzaldehyde, octanal, limonene,
1,8-cineol, methyl benzoate, nonanal, decanal and geranyl acetone were
identified. In the acetone extract we identified eight EAG-active peaks as
phenol, nonanal, 2-ethylhexanoic acid, octanoic acid, benzoic acid, nonanoic
acid, decanoic acid and dimethyl phthalate. The concentrations of benzoic acid
and benzaldehyde present in laboratory air were determined. The origin of the
substances and importance of such odorants in laboratory air for the
interpretation of physiological experiments on the olfactory system is discussed.
PMID- 10667992
TI - Sucrose octaacetate avoidance in nontaster mice is not enhanced by two type-A Prp
transgenes from taster mice.
AB - The Soa bitter-sensitivity and Prp salivary-protein loci map to distal mouse
chromosome six. No recombination has been found between sucrose octaacetate (SOA)
avoidance phenotype and PRP haplotype in any mouse population. Soa and Prp,
therefore, are either very near each other or identical. To assess the latter
possibility, two type-A, proline-rich protein genes (MP2 and M14), situated
approximately 30 kb apart at the Prp locus, were separately transferred from an
SOA-taster inbred strain (SWR) to an SOA-nontaster inbred strain (FVB). Five MP2
transgenic mice and seven M14-transgenic mice were insensitive to 1 mM SOA in two
bottle tests, thus retaining the nontaster FVB phenotype. Each transgenic mouse
was mated to control FVB mice. Their transgene-positive F1 and F2 offspring also
were insensitive. Transgene expression varied among the founder lines, but SWR
like expression levels, higher than background FVB expression levels, were found
in submandibular gland tissue of adult transgenic mice from two MP2 lines and one
M14 line. F3 mice from one of these MP2 lines were mated to F2 mice from the M14
line. Nine offspring inherited both transgenes. All nine were insensitive to 1 mM
SOA. These findings indicated that expression of mRNAs for both type-A Prp genes
alone or together did not enhance SOA taste sensitivity in nontaster mice.
PMID- 10667993
TI - 'Microsmatic' primates revisited: olfactory sensitivity in the squirrel monkey.
AB - Using a conditioning paradigm, the olfactory sensitivity of three squirrel
monkeys to nine odorants representing different chemical classes as well as
members of a homologous series of substances was investigated. The animals
significantly discriminated dilutions as low as 1:10,000 n-propionic acid,
1:30,000 n-butanoic acid and n-pentanoic acid, 1:100,000 n-hexanoic acid, 1:1Mio
n-heptanoic acid, 1:30, 000 1-pentanol, 1:300,000 1,8-cineole, 1:1Mio n-heptanal
and 1:30Mio amyl acetate from the near-odorless solvent, with single individuals
scoring even slightly better. The results showed (i) the squirrel monkey to have
an unexpectedly high olfactory sensitivity, which for some substances matches or
even is better than that of species such as the rat or the dog, and (ii) a
significant negative correlation between perceptibility in terms of olfactory
detection thresholds and carbon chain length of carboxylic acids. These findings
support the assumptions that olfaction may play a significant and hitherto
underestimated role in the regulation of primate behavior, and that the concept
of primates as primarily visual and 'microsmatic' animals needs to be revised.
PMID- 10667994
TI - Responses to putative second messengers and odorants in water nose olfactory
neurons of Xenopus laevis.
AB - Using the whole-cell mode of the patch-clamp technique, we attempted to record
inward currents in response to cAMP, inositol 1,4, 5-trisphosphate (IP(3)) and
odorants from sensory neurons in the olfactory epithelium of the Xenopus laevis
lateral diverticulum (water nose). Dialysis of 100 microM of IP(3) induced inward
currents, while dialysis of 1 mM of cAMP into olfactory neurons did not induce
any response under the voltage-clamp conditions. Changes in membrane conductance
were examined by applying ramp pulses. The slope of the current-voltage (I-V)
curve during the IP(3)-induced response was steeper than that after the response,
indicating that IP(3) increased the membrane conductance. The water nose
olfactory neurons have been shown to respond to both amino acids and volatile
odorants. The slopes of I-V curves during responses to amino acids and a volatile
odorant, lilial, were similar to those before the responses, suggesting that the
total membrane conductance was not changed during responses to amino acids and
the volatile odorant.
PMID- 10667995
TI - Evidence for nicotinic acetylcholine receptors on nasal trigeminal nerve endings
of the rat.
AB - The peripheral chemoreceptors of the trigeminal system in the nasal cavity are
presumed to be free nerve endings arising from Adelta and C fibers. These fibers
appear to be scattered throughout the nasal epithelium, and arise from the
nasopalatine and ethmoid branches of the trigeminal nerve. In the present study,
the effects of nicotinic acetylcholine receptor (nAChR) blockers on ethmoid nerve
responses to nicotine and cyclohexanone were examined. Multiunit neural
recordings were obtained from the ethmoid nerve of Sprague-Dawley rats. Vapor
phase nicotine (12.5 p.p.m.) and cyclohexanone (450 p.p. m.) were delivered to
the rats' nares via an air-dilution olfactometer. The magnitude of the response
to nicotine decreased after the administration of the nAChR blockers dihydro-beta
erythroidine hydrobromide (DHBE) and mecamylamine hydrochloride. DHBE is a
competitive nicotinic receptor antagonist specific for the alpha4beta2 receptor
subtype and mecamylamine is known to bind alpha3beta4 and alpha4beta2 receptors.
The nAChR blockers had no effect on ethmoid nerve responses to cyclohexanone.
These results suggest that the mechanism by which at least one irritant
stimulates nasal trigeminal nerve endings involves the binding of irritant with a
specific receptor.
PMID- 10667996
TI - Chemosensitive conductance and inositol 1,4,5-trisphosphate-induced conductance
in snake vomeronasal receptor neurons.
AB - Snake vomeronasal receptor neurons in slice preparations were studied using the
patch-clamp technique in the conventional and nystatin-perforated whole-cell
configurations. The mean resting potential was approximately -70 mV; the average
input resistance was 3 GOmega. Neurons required current injection of only 1-10 pA
to display a variety of spiking patterns. Intracellular dialysis of 100 microM
inositol 1,4,5-trisphosphate (IP(3)) evoked an inward current in 38% of neurons,
with an average peak amplitude of 16.4 +/- 2.8 pA at a holding potential of
70mV. Application of 100 microM 3-deoxy-3-fluoro-D-myo-inositol 1,4,5
trisphosphate (F-IP(3)), a derivative of IP(3), also evoked an inward current in
4/8 (50%) neurons (32.6 +/- 58 pA at -70 mV, n = 4). The reversal potentials of
the induced components were estimated to be -14 +/- 5 mV for IP(3) and -17 +/- 3
mV for F-IP(3). Bathing the neurons in 10 microM ruthenium red solution greatly
reduced the IP(3)-evoked inward current to 1.6 +/- 1.1 pA at -70 mV (n = 6). With
Cs(+)-containing internal solution, neither the Ca(2+)-ATPase inhibitor
thapsigargin (1-50 microM) nor the Ca(2+)-ionophore ionomycin (10 microM) evoked
a significant current response, suggesting that IP(3) can elicit current response
in the neurons without mediation by intracellular Ca(2+) stores. Intracellular
application of 1 mM cAMP evoked no detectable current response. Extracellular
application of chemoattractant for snakes evoked a very large inward current. The
reversal potential of the chemoattractant-induced current was similar to that of
the IP(3)-induced current. The present results suggest that IP(3) may act as a
second messenger in the transduction of chemoattractants in the garter snake
vomeronasal organ.
PMID- 10667997
TI - Odor distinctiveness between enantiomers of linalool: difference in perception
and responses elicited by sensory test and forehead surface potential wave
measurement.
AB - The effects on humans of inhalation of optically active linalools were examined
in terms of sensory tests and portable forehead surface electroencephalographic
(IBVA-EEG) measurements in order to assess their odor distinctiveness by chiral
isomers. (R)-(-)-Linalools with specific rotation of [alpha](D) = -15.1 degrees
were isolated by repeated flash column chromatography from lavender oil, while
(S)-(+)-linalools with [alpha](D) = +17.4 degrees and (RS)-(+/-)-linalools with
[alpha](D) = 0 degrees and content of (R)-form 50.9% and (S)-form 49.1% were
obtained from coriander oil and commercial linalool, respectively, by using the
same method. With the use of an inhalator, each was administered to subjects both
before and after 10 min of work. It was found that administration after work
evoked different subjective impressions when compared with that before work
depending on the configuration of the isomers and the type of work employed. For
instance, inhalation of (R)-(-)-linalool after hearing environmental sounds not
only produced a much more favorable impression in the sensory test but was also
accompanied by a greater decrease in beta waves after work in comparison with
that before work. This is in contrast to the case of mental work, which resulted
in a tendency for agitation accompanied by an increase in beta waves. These
findings led us to conclude that enantiomeric stereospecificity of linalool
evoked different odor perception and responses not only with chiral dependence
but also with task dependence. In addition, in comparing these sensory profiling
features and IBVA-EEG tendencies between hearing environmental sound and mental
work, a tendency was observed for (R)-(-)-linalool to coincide with (RS)-(+/-)
linalool but not with (S)-(+)-linalool.
PMID- 10667998
TI - Contrast and range effects for category, magnitude and labeled magnitude scales
in judgements of sweetness intensity.
AB - The labeled magnitude scale (LMS) is a verbally anchored quasi-logarithmically
spaced response scale with properties similar to magnitude estimation. Three
experiments examined whether the LMS showed context effects similar to those
found with magnitude estimation and category scales. Two versions of the LMS were
used, one anchored at the high end to the strongest imaginable sweetness and the
other to the strongest imaginable oral sensation. In a simple contrast
experiment, subjects judged the sweetness of a 10% sucrose fruit beverage in the
context of a less sweet (5%) beverage or a more sweet (20%) beverage. Consistent
with previous literature, the sweetness was judged more intense in the low
context and less intense in the high context, for all scaling methods. In a
second experiment, this effect persisted (although was smaller) when the
contextual item preceded the to-be-rated item, a so-called 'reversed-pair'
design. Once again, the effect was highly significant for all scaling methods. In
a third experiment, a range effect was examined using wide and narrow ranges of
concentration. Psychophysical functions were flatter in a wide context and
steeper in a narrow context, consistent with previous observations on range
mapping bias. This result was obtained for all scales. In three common contextual
effects, the labeled magnitude scale behaved similarly to other scaling
procedures. Its application to comparisons across individuals may be limited if
those individuals have different experiential contexts within which they make
their judgements.
PMID- 10667999
TI - Olfactory receptor neurons in partially purified epithelial cell cultures:
comparison of techniques for partial purification and identification of insulin
as an important survival factor.
AB - Olfactory neurons have the rare property of being replaced throughout life.
Factors regulating different developmental stages of olfactory receptor neurons
(ORNs) are of great interest, because such factors might be used to extend
regeneration in the post-developmental brain and spinal cord. Also, these factors
may potentially be exploited to treat various smell disorders arising from
changes in the olfactory epithelium. Characterization of trophic factors for ORNs
requires cell culture systems that are simple and easy to manipulate. We have
compared four different cell culture preparations, using two different enzymes
and two different media to develop a simple culture system of olfactory
epithelial cells. Our preferred preparation, which produces partially purified
olfactory epithelial cultures, uses trypsin dissociation and a serum-free
keratinocyte growth medium (KGM) supplemented with insulin. These conditions
support ORN survival up to 1 week. They also supported other elements of the
olfactory epithelium such as Bowman's gland cells and horizontal basal cells.
Olfactory epithelial cells predominate, while contaminating mesenchymal cells
(glia and fibroblasts) are present in low numbers. Using these cultures, it was
determined that insulin was required for ORN survival in vitro. The simplicity of
the epithelial cultures will be useful for further studies of insulin and other
ORN trophic factors.
PMID- 10668000
TI - Alarm reaction in the crucian carp is mediated by the medial bundle of the medial
olfactory tract.
AB - Experiments were performed to determine which bundles of the olfactory tracts
were essential for mediating alarm reaction in crucian carp (Carassius carassius
L.). The fish were maintained in physiological saline after surgery to preserve
the remaining tracts and postoperative inspections revealed the functionality of
the intact tracts. Operations on the tracts were performed symmetrically on both
sides. Sham-operated and non-operated fish showed the typical alarm behaviour of
fast swimming to the bottom, dashing movements and aggregation when exposed to
skin extract which contain alarm substance. Fish with only the medial bundle of
the medial olfactory tract intact also displayed the alarm behaviour upon
exposure; however, these fish did not react to the amino acid, L-alanine with
either feeding response or alarm reaction. Crucian carp which had the medial
bundle of the medial olfactory tract cut, leaving both the lateral bundle of the
medial olfactory tract and the lateral olfactory tract intact, did not display
any alarm reaction to skin extract; however, these fish reacted to exposure to L
alanine with feeding behaviour. There were statistically significant differences
between the behaviour scores for the fish subject to different treatments. The
present study demonstrates that the medial bundle of the medial olfactory tract
appears to be both necessary and sufficient for mediation of the alarm reaction.
The results also show that the sensory neurons which respond to alarm substance
terminate and make synaptic connections with the secondary neurons that make up
the medial bundle of the medial olfactory tract; thereby demonstrating the
specificity of the spatial aspect of olfactory processing. The results are
discussed with respect to the spatial aspect of organization within the olfactory
system, the pattern of generalization across orders of fish, and the functional
implications of the spatial arrangement of information transmission between the
peripheral olfactory organ and the brain.
PMID- 10668001
TI - Odour-evoked autobiographical memories: psychological investigations of proustian
phenomena.
AB - Folk wisdom dictates that odours are especially powerful reminders of
autobiographical experience, an effect which has become known as the Proust
phenomenon. This paper reviews the relevant literature to determine whether there
is any substantive evidence to support this view. Different methodologies have
been adopted in addressing this issue, but the most revealing and ecologically
valid have been the few studies which have examined naturally formed
autobiographical memories. From these data, there is at least preliminary
evidence that olfactory stimuli can cue autobiographical memories more
effectively than cues from other sensory modalities. Explanations for these
effects can be invoked from accepted principles in contemporary cognitive
psychology.
PMID- 10668002
TI - The psychopathy checklist--screening version: an examination of criteria and
subcriteria in three forensic samples.
AB - The development and refinement of psychopathy represent a critical issue in
clinical and forensic practice. During the last decade, important advances in the
operationalization of psychopathy were achieved, primarily through the
development of the Psychopathy Checklist (PCL) and its subsequent versions (PCL-R
and PCL:SV). PCL ratings are based primarily on item descriptions or subcriteria.
The current study serves to break new ground as the first systematic
investigation of PCL:SV subcriteria by addressing their psychometric properties
and exploring their construct and criterion-related validation. Previously
unanalyzed data from three samples were integrated: female offenders, male
forensic patients, and male adolescent offenders. Results largely support the use
of subcriteria as homogeneous components of criteria and provide strong initial
evidence of their construct validity. Results are less conclusive regarding
criterion-related validity. For female offenders, they suggested the potential
value of specific PCL:SV subcriteria for predicting verbal aggression.
Confirmatory factor analysis provided encouraging results on the applicability of
the standard two-factor model of psychopathy. However, a first-order principal
axis factoring suggested further refinements in our understanding of psychopathy.
PMID- 10668003
TI - Psychometric properties of the state-trait anxiety inventory for Asian/Pacific
islander adolescents.
AB - Anxiety disorders are said to be universal across all cultures and recent reviews
have found relatively high prevalence rates across different countries. However,
the experience and interpretation of anxiety are strongly influenced by cultural
factors. Demonstrating cross-cultural equivalence of measures of anxiety is
essential to assure that comparisons between cultures will result in meaningful
interpretations. Despite the State-Trait Anxiety Inventory being the most
researched of anxiety measures from a cross-cultural basis, there is a lack of
empirical studies on the psychometric properties of the STAI with adolescent
Asian/Pacific Islanders. The present study examined the STAI using a large sample
of ethnically diverse high school students in Hawaii. In general, a four-factor
model (State-Anxiety Absent, State-Anxiety Present, Trait-Anxiety Absent, and
Trait-Anxiety Present) provided the best fit based on a series of confirmatory
factor analyses. Indicators of internal consistency supported the reliability of
the factors and subscales, and the inter-factor correlations reflected positively
on the concurrent validity of the different STAI factor and subscale measures.
This study suggested cautious use and interpretation of one particular item
(Trait Item 14 = I try to avoid facing a crisis or difficulty ), and cautious
application of the STAI to Filipino adolescents (particularly Filipino males).
Domains for further research are discussed.
PMID- 10668004
TI - Item response theory in personality assessment: a demonstration using the MMPI-2
depression scale.
AB - Item response theory (IRT) analyses have, over the past 3 decades, added much to
our understanding of the relationships among and characteristics of test items,
as revealed in examinees response patterns. Assessment instruments used outside
the educational context have only infrequently been analyzed using IRT, however.
This study demonstrates the relevance of IRT to personality data through analyses
of Scale 2 (the Depression Scale) on the revised Minnesota Multiphasic
Personality Inventory (MMPI-2). A rich set of hypotheses regarding the items on
this scale, including contrasts among the Harris-Lingoes and Wiener-Harmon
subscales and differences in the items measurement characteristics for men and
women, are investigated through the IRT analyses.
PMID- 10668005
TI - Can the MMPI-2 validity scales detect depression feigned by experts?
AB - Major depression is one of the most frequently presented disorders for claims of
psychiatric disability. Evidence also suggests that many individuals making
claims of disability exaggerate or even fabricate mental illness. These facts
suggest that the detection of feigned depression is an important task in
psychiatric disability claim assessments. In this study, the capacity of a number
of MMPI-2 validity scales and indicators to detect feigned depression was
examined. Twenty-three mental health professionals with specific expertise and
significant experience in assessing and treating major depression were asked to
complete the MMPI-2 as if they were suffering from major depression. The MMPI-2
protocols of this sample were compared to those of a sample of patients diagnosed
with major depression. Results indicated that the validity scales F, back F (FB),
and the Dissimulation scale (Ds) were highly successful at distinguishing MMPI-2
protocols of feigned depression from bona fide depression. Replicating results
from previous studies, however, FB proved most effective, outperforming all other
validity scales and indicators, including F and Ds. These findings suggest that
even experts are unable to feign major depression successfully on the MMPI-2, and
that the FB scale might be the most effective indicator for detecting feigned
depression.
PMID- 10668007
TI - Comparison of MMPI-2 profiles of Gulf War veterans with epileptic and
nonepileptic seizure patients.
AB - As part of a larger study of illnesses related to service in the Gulf War, MMPI-2
profiles of epileptic seizure (ES) patients; nonepileptic seizure (NES) patients;
Gulf War veterans with unexplained cognitive, psychological, musculoskeletal,
fatigue, or dermatologic symptoms; and asymptomatic Gulf War veterans (Controls)
were analyzed. There were 70 people in each group. Seizure diagnosis was based
upon intensive EEG monitoring. Gulf War cases were mildly abnormal on MMPI-2
Scales Hs and D and significantly higher than controls on 8 of 10 MMPI-2 clinical
scales, but they were significantly lower than NES patients on several scales
including Hs and Hy.
PMID- 10668006
TI - The validity of the general ability measure for adults: comparison with WAIS-R IQ
scores in a sample of college students with academic difficulties.
AB - The present study investigated the validity of the General Ability Measure for
Adults (GAMA) by comparing it to the WAIS-R using a sample of 80 college students
reporting learning difficulties. Results indicated that the mean GAMA IQ score
did not deviate significantly from the mean WAIS-R IQ scores. The GAMA Full Scale
IQ correlated significantly with the WAIS-R PIQ, VIQ, and FSIQ scores. However,
the obtained correlation coefficient for the GAMA and WAIS-R PIQ significantly
differed from the observed correlation coefficient between the GAMA and WAIS-R
VIQ, suggesting that the GAMA was more clearly associated with perceptual skills
than verbal abilities. When the correlation coefficients between the GAMA and
WAIS-R scores were corrected for the effects of range restriction, the
correlation coefficients increased, yet demonstrated the same pattern (e.g.,
GAMA/PIQ,.69; GAMA/VIQ,.36; GAMA/FSIQ,.60). The GAMA s accuracy in predicting
individual student performance on the WAIS-R FSIQ also was examined.
PMID- 10668008
TI - Observations on the factor structure of the WAIS-R.
AB - Confirmatory factor analyses (CFAs) revealed 2 important characteristics of the
standardization data of the Wechsler Adult Intelligence Scale Revised. One
finding was that Digit Symbol fit better on an attentional factor in younger
groups, but fit was better when Digit Symbol loaded on a visual-perceptual factor
in older groups. A second observation was that specifying correlated errors or a
fourth factor to explain covariance between Block Design and Object Assembly
improved model fit in all age groups except 70- to 74-year-olds. The results
illustrate the value of CFA and have implications for investigating other samples
and other Wechsler tests.
PMID- 10668009
TI - MMPI code types and the fantasy prone personality.
AB - We administered the MMPI and the Inventory of Childhood Memories and Imagining
(ICMI) to 1,200 college students. Application of diagnostic efficiency statistics
for the ability of differing ICMI cutoff scores to identify college students
producing a schizophrenia spectrum MMPI code type revealed that scores greater
than or equal to 29 on the ICMI had good positive predictive power. Scores less
than 29 on the ICMI had very good negative predictive power. ICMI scores were
also used to form a group of fantasizers (n = 30) and a control group (n = 30).
Fantasizers were much more likely to produce MMPI codes associated with a
vulnerability to schizophrenia (70%) than were controls (3.33%). Although most
controls(70%) produced non-elevated MMPI scores, 66.67% of the fantasizers
produced three or more elevated clinical scales on the MMPI. The modal MMPI
profile for the fantasizers was an 8-9 code, indicating that fantasizers appear
at heightened risk for eccentric thinking and a Cluster A or B personality
organization.
PMID- 10668010
TI - Scale 5 of the MMPI and MMPI-A: evidence of disparity.
AB - Scale 5 of the MMPI and MMPI-A was compared in a repeated measures design.
Participants for the study were 43 adolescents classified as emotionally
disturbed in a public school system and 17 inpatients at a residential treatment
center. The MMPI Scale 5 mean score was substantially higher than that of the
MMPI-A. The alternate-form reliability between Scale 5 of the two forms was
surprisingly low, suggesting that the deletion of 16 items and rewording of 6
additional items changed the scale on the MMPI-A to an extent that may have
significantly altered the underlying construct. The authors discuss factors that
could be associated with the findings, including: (a) the diminished ability to
express feminine interest on the MMPI-A, and (b) general changes in attitudes
among adolescents over the 3 or more decades since the MMPI norms were developed.
PMID- 10668011
TI - Noninvasive assessment of left ventricular systolic function by stress-shortening
relation, rate of change of power, preload-adjusted maximal power, and ejection
force in idiopathic dilated cardiomyopathy: prognostic implications.
AB - Indexes of left ventricular systolic function that are considered relatively load
insensitive were assessed to determine their relation to the severity of heart
failure symptoms and their ability to predict the outcome of idiopathic dilated
cardiomyopathy. Stress, flow, power, and ejection force were calculated
throughout ejection by echocardiography at rest in 35 patients with idiopathic
dilated cardiomyopathy and in 20 control subjects. Patients were evaluated
prospectively every 6 months for 2 years. Asymptomatic patients were separated
most clearly from New York Heart Association (NYHA) class II by end-systolic
stress; NYHA class II patients were separated from NYHA class III and the latter
from NYHA class IV by peak rate of change of flow. Ten patients showed
improvement in symptoms as well as in systolic indexes; none of them died during
the follow-up. Improvement was unpredictable with the evaluated variables. One-
and 2-year cardiovascular mortality rates were 17% and 26%, respectively.
Patients whose condition did not improve after the first year had a 17% second
year mortality rate. Peak rate of change of power predicted death with 100%
sensitivity, 56% specificity, and 64% positive predictive value in NYHA III and
IV patients.
PMID- 10668012
TI - Mean myocardial velocity mapping in quantifying regional myocardial contractile
reserve in patients with impaired left ventricular systolic function: Doppler
myocardial imaging study.
AB - The aim of this study was to use Doppler myocardial imaging-derived mean
myocardial velocity (MMV) at baseline and during low-dose dobutamine stress
echocardiography (DSE) to quantify regional contractile reserve of the left
ventricle (LV). Sixteen patients (mean age 59 +/- 7 years) with coronary artery
disease and regional left ventricular wall motion abnormalities were studied.
During each increment of Dobutamine infusion, 6 2-dimensional transthoracic
apical images were acquired in standard gray-scale and Doppler myocardial imaging
modes at 30 degrees steps over 180 degrees. For the analysis, the LV was divided
into 18 segments. For each segment, both wall motion score and MMV obtained in
systole and both early and late diastole were measured at baseline and at each
stage of DSE. In viable segments by wall motion score, MMV increased during DSE
in systole and in early and late diastole. In contrast, in nonviable segments,
MMV did not change during DSE. Mean myocardial velocity mapping is a promising
new approach to quantify regional myocardial contractile reserve of the LV.
PMID- 10668013
TI - Subendocardial motion in hypertrophic cardiomyopathy: assessment from long- and
short-axis views by pulsed tissue Doppler imaging.
AB - BACKGROUND: Tissue Doppler imaging (TDI) is a recently developed technique that
allows the instantaneous measurement of intrinsic regional myocardial motion
velocity. Pulsed TDI is capable of separately assessing left ventricular (LV)
regional motion velocity caused by circumferential and longitudinal fiber
contraction. This particular feature of function is still controversial in
patients with hypertrophic cardiomyopathy (HC). METHODS: To better characterize
intrinsic circumferential and longitudinal LV systolic myocardial function in HC,
we used pulsed TDI to measure short- and long-axis LV motion velocities,
respectively. The subendocardial motion velocity patterns at the middle of the LV
posterior wall (PW) and ventricular septum (IVS) in LV parasternal and apical
long-axis views were recorded by pulsed TDI in 19 patients with nonobstructive HC
and in 21 normal controls (NC). RESULTS: Peak short- and long-axis systolic
subendocardial velocities in both the LV PW and IVS were significantly smaller in
the HC group than in the NC group, and the time to peak velocity was
significantly delayed. Furthermore, peak PW systolic velocity was significantly
greater along the long axis than along the short axis in the NC group (8.8 +/-
1.5 cm/s vs 8.2 +/- 1.4 cm/s, P <.05), whereas the opposite was observed in the
HC group (6.1 +/- 1.2 cm/s vs 7.5 +/- 1.0 cm/s, P <.0001). No significant
differences were found in either group between the long- and short-axis IVS
velocities (HC: 5.9 +/- 1.4 cm/s vs 5.5 +/- 1.3 cm/s; NC: 7.8 +/- 1.3 cm/s vs 7.9
+/- 1.6 cm/s). CONCLUSIONS: By using the capability of pulsed TDI for the
evaluation of intrinsic myocardial velocity instantaneously in a specific region
and direction, we found impairment of LV myocardial systolic function in patients
with HC not only in the hypertrophied IVS but also in the nonhypertrophied LV PW.
We also found a greater decrease in LV PW velocities along the long axis than the
short axis, suggesting greater impairment of long-axis contraction in patients
with HC. Because our HC patients did not appear to have excessive intracavitary
pressure, these results suggest that the relatively normal-appearing PW is
directly affected by the HC pathologic process.
PMID- 10668014
TI - Estimation of the ejection fraction in patients with myocardial infarction
obtained from the combined index of systolic and diastolic left ventricular
function: a new method.
AB - The index of myocardial performance combining systolic and diastolic time
intervals (Index) is a useful method, already explained in past studies, that
offers new values that have not been widely known among clinical cardiologists.
The aim of this study is to obtain from this Index a measurement of the ejection
fraction (EF), which is a very well-known value. The study involved 97 patients
with myocardial infarction, 55 of whom were studied retrospectively (group A,
aged 46-62 years, 50 men) to obtain and test the formula EF = 60 - (34 x Index).
The second group (group B, aged 47-63 years, 40 men) included 42 patients who
were evaluated prospectively. The EF obtained was compared with that reached
through the use of radionuclide angiography (EF-RNA). The Index was obtained
through the use of the formula (a - b)/b, where a is the interval between
cessation and onset of the mitral inflow, and b is the ejection time. In group A
the EF obtained by the Index (EF-Index) was 37.5% +/-.8%, and the EF-RNA was
37.7% +/- 11% (r = 0.76). In group B the EF-Index was 41.6% +/- 7%, and the EF
RNA was 41.2% +/- 10% (r = 0. 75). CONCLUSION: Through the new formula described
here it is possible to obtain a reliable measurement of the EF in patients with
myocardial infarction, a well-known and extremely useful value, especially for
those patients with poor acoustic windows.
PMID- 10668015
TI - Ordering an echocardiogram for evaluation of left ventricular function: level of
expertise necessary for efficient use.
AB - This prospective study was performed to test the hypothesis that the yield of 2
dimensional echocardiography (2DE) would be higher when it is ordered by a
cardiologist than by a noncardiologist. Patients referred for transthoracic 2DE
for the evaluation of left ventricular systolic function for the 11-month period
between July 10, 1995, and June 10, 1996, were included in the study.
Demographic, historical, and clinical findings were recorded. Whether the patient
was referred by a cardiologist versus a noncardiologist was used as the predictor
variable in a binary logistic regression analysis. To address the possibility
that the yield of 2DE may be higher for cardiologists because the prevalence of
disease in patients referred to them may be higher (selection bias), the analysis
was subjected to a propensity score adjustment. Of 2176 patients referred for 2DE
during the study, 1033 were referred for the evaluation of left ventricular
function. The test had a positive yield in 52% of patients for cardiologists
versus 31% for noncardiologists (chi(2) = 45.5, P <.0001, odds ratio 2.4 [CI = 1.
9-3.1]). This difference remained highly significant even when propensity score
risk adjustment was made (chi(2) = 54.2, P <.0001, odds ratio 2.0 [CI = 1.5
2.8]). We conclude that the yield of 2DE is higher for cardiologists compared
with noncardiologists and that this result was not related to differences in
patient populations examined by the two groups. Thus, more efficient use of 2DE
may be achieved if patients are referred to cardiologists rather than directly
sent for 2DE.
PMID- 10668016
TI - The role of echocardiographic harmonic imaging and contrast enhancement for
improvement of endocardial border delineation.
AB - Despite advances in imaging technology, many myocardial segments remain poorly
visualized with echocardiography; however, both contrast enhancement and harmonic
imaging have shown promise for improving endocardial definition. Fifty subjects
with technically limited echocardiograms were studied with fundamental and
harmonic imaging as well as during echocardiographic contrast injection. Overall
endocardial visualization scores improved with both techniques compared with
fundamental imaging. Harmonic imaging improved endocardial visualization in 43%
of all segments and in 57% of segments nonvisualized with fundamental imaging.
The benefit of harmonic imaging was seen in all segments. Contrast
echocardiography had similar overall improvements in visualization (42% of all
segments, 67% of segments nonvisualized with fundamental imaging) but was not
helpful in all regions. Harmonic imaging outperformed contrast in 9 of 22
segments, whereas contrast was superior in 4 of 22. In a subgroup of patients
with very poor images, contrast enhancement was superior, with a greater increase
in overall score and a higher salvage rate than harmonic (68% vs 40%).
PMID- 10668017
TI - Harmonic imaging with Levovist for transthoracic echocardiographic reconstruction
of left ventricle in patients with post-ischemic left ventricular dysfunction and
suboptimal acoustic windows.
AB - BACKGROUND: Attempts to perform transthoracic 3-dimensional echocardiography
(3DE) are often encumbered by poor definition of chamber borders in adult
patients who have technically suboptimal acoustic windows. METHODS: To assess
whether harmonic imaging (HI) and contrast agents can facilitate transthoracic
3DE assessment of the left ventricle, we used fundamental imaging (FI), HI alone,
and HI coupled with the echo-enhancing contrast agent Levovist in 15 consecutive
patients with post-ischemic left ventricular (LV) dysfunction and technically
difficult windows. Dynamic 3DE image data sets were obtained at 5-degree angles
(36 slices) from a transthoracic apical view. From these data a total of 240
myocardial segments were analyzed with the use of dynamic short-axis paraplane
slices at basal, middle, and apical LV levels (standard 16 segment model). For
border definition, each segment was scored in random sequence on the following
scale by 2 independent investigators: 0 = not seen, 1 = suboptimal visualization,
and 2 = well defined. RESULTS: Our results showed a significant increase in the
number of well-visualized segments when harmonic mode combined with Levovist
injection was compared with FI and HI alone. CONCLUSION: Harmonic imaging alone
improves LV assessment by 3DE when compared with FI. Contrast imaging in which
Levovist is added to HI further improves the capability of transthoracic
tomographic 3DE in the visualization of LV myocardial segments. This could allow
3DE by transthoracic windows to be used more widely in adults for the evaluation
of LV volume and function.
PMID- 10668018
TI - Apical hypertrophic cardiomyopathy: echocardiographic diagnosis with the use of
intravenous contrast image enhancement.
AB - Echocardiographic image enhancement with an intravenous second-generation
contrast agent established the diagnosis of apical hypertrophic cardiomyopathy in
2 patients initially thought to have left ventricular apical thrombus. Image
enhancement with contrast agent obviated the need for invasive diagnostic tests,
underscoring its applicability in patients with suspected left ventricular
masses.
PMID- 10668019
TI - Acute infarction of a previously stented coronary artery precipitated by
dobutamine stress echocardiography.
AB - A case is reported of acute myocardial infarction (MI) in a previously stented
left anterior descending coronary artery, which occurred shortly after uneventful
dobutamine stress echocardiography. Myocardial infarction precipitated by
dobutamine has been reported only rarely, as has exercise-related MI after
stenting. This is the first case of dobutamine-induced MI in a recently stented
artery.
PMID- 10668020
TI - Acute cardiac rupture during dobutamine-atropine echocardiography stress test.
AB - We report an acute cardiac rupture during dobutamine-atropine echocardiography
stress test on the sixth day after admission for an inferoposterior acute
myocardial infarction complicated with mild pericardial effusion.
PMID- 10668021
TI - A case of arrhythmogenic right ventricular cardiomyopathy in sinus rhythm
associated with thrombus in the right atrium.
AB - We describe a patient with arrhythmogenic right ventricular cardiomyopathy (ARCV)
in sinus rhythm associated with thrombus in the right atrium. The occurrence of a
right heart thrombus in ARCV is extremely rare and, to our knowledge, has been
previously reported only in the right ventricle. In our case, ARCV most probably
led to right atrial spontaneous echo contrast, and later, right atrial thrombus
formation by blood stasis caused by right ventricular systolic dysfunction. In
conclusion, our case suggests that right atrial thrombus may occur in ARCV, even
in sinus rhythm.
PMID- 10668022
TI - Congestive heart failure and the role of two-dimensional Doppler
echocardiography: a primer for cardiac sonographers.
AB - Congestive heart failure (CHF) has been an increasing cause of hospitalization,
particularly among the elderly population, although the clinical presentation may
vary in the individual patient. Two-dimensional and pulsed Doppler
echocardiography can be valuable diagnostic methods for the assessment of
afflicted patients and can have an impact on patient outcome. The unique
advantage of echocardiographic techniques is their ability to characterize left
ventricular systolic performance and diastolic filling abnormalities that are
commonly present in patients with CHF. This review provides current information
the cardiac sonographer can recognize in the assessment of patients with CHF.
PMID- 10668023
TI - Echocardiographic features of genetic diseases: part 2. Storage disease.
PMID- 10668024
TI - Hierarchy of research design used to categorize the "strength of evidence" in
answering clinical dental questions.
AB - The purpose of this article is to highlight important features of research design
that clinicians can use to determine which articles are useful when attempting to
answer clinical questions and determine the best therapy for a particular
patient. This article offers a systematic means of categorizing the quality of
research reports for clinicians and clinical investigators. A recurring clinical
theme of hygiene education is used to exemplify how phrasing the clinical
question determines the type of study design that could be used. The article
describes the continuum of research reports, and categorizes them by their
inherent strengths and weaknesses. The report describes why the research designs
in the supreme position of the research hierarchy, are the most valuable to
clinicians seeking evidence that defines the best therapy for their patients.
PMID- 10668025
TI - Autogenous and allogenous bone grafting techniques to maximize esthetics: a
clinical report.
PMID- 10668026
TI - Mandibular centricity: centric relation.
AB - Centric relation can be a confusing term because it continues to evolve in
meaning. This article presents a discussion of the historical aspects of centric
relation. Guidelines to decide when to use centric relation in clinical dentistry
are included.
PMID- 10668027
TI - Accuracy of three polyvinyl siloxane putty-wash impression techniques.
AB - STATEMENT OF PROBLEM: There is much discussion in the dental literature
concerning the effect of the impression technique on the accuracy of cast
restorations. PURPOSE: This study assessed the accuracy of 3 putty-wash
impression techniques using the same impression material (polyvinyl siloxane) in
a laboratory model. MATERIAL AND METHODS: The 3 putty-wash impression techniques
used were (1) 1-step (putty and wash impression materials used simultaneously);
(2) 2-step with 2-mm relief (putty first as a preliminary impression to create 2
mm wash space with prefabricated copings. In the second step, the wash stage was
carried out); and (3) 2-step technique with a polyethylene spacer (plastic spacer
used with the putty impression first and then the wash stage). For each
technique, 15 impressions were made of a stainless steel master model that
contained 3 complete crown abutment preparations, which were used as the positive
control. Accuracy was assessed by measuring 6 dimensions (intraabutment and
interabutment) on stone dies poured from impressions of the master model.
RESULTS: One-way analysis of variance showed statistically significant
differences among the 3 putty-wash impression techniques, for all intraabutment
and interabutment measurements (P <.001). Overall discrepancies of the 2-step
technique with 2-mm relief putty-wash impression technique were significantly
smaller than that in the 1-step and polyethylene putty-wash impression
techniques. CONCLUSION: The polyvinyl siloxane 2-step, 2-mm, relief putty-wash
impression technique was the most accurate for fabricating stone dies.
PMID- 10668028
TI - Color stability of new-generation indirect resins for prosthodontic application.
AB - STATEMENT OF PROBLEM: Several new-generation indirect resins are being advocated
for full contour restoration of teeth. Previous indirect resin systems have
failed in this application, due in part to color instability. PURPOSE: This study
evaluated and characterized the color stability of various new-generation
indirect resins (ceramic-polymers) when subjected to accelerated aging. MATERIAL
AND METHODS: Four new-generation indirect resin systems, 1 direct resin system,
and 1 dental porcelain control were subjected to accelerated aging for a period
of 300 hours. Initial specimen color parameters were determined in the Commission
International de l'Eclairage Lab (CIELAB) color order system with a colorimeter.
Color changes (DeltaE) were calculated between baseline color measurements and
measurements made after 150 and 300 hours of accelerated aging. Color difference
data were subjected to a 1-way analysis of variance to examine the interaction
between material and time interval of aging. Where significant interactions
occurred, a least-squared means test was performed to identify differences in the
color stability between the materials (P =.05). RESULTS: After 300 hours of
accelerated aging, color changes of the indirect resins ranged between 0.62 and
3.40 DeltaE units. Two of the products tested demonstrated color stability that
was not significantly different from the porcelain control. CONCLUSION: All the
indirect resins tested demonstrated color stability at or below a quantitative
level that would be considered clinically acceptable. Color changes of ceramic
polymers occurred because of changes in chroma, rather than alterations in
lightness.
PMID- 10668029
TI - Fracture load and mode of failure of ceramic veneers with different preparations.
AB - STATEMENT OF PROBLEM: Fracture is a clinical failure modality for ceramic
veneers. Whether design of tooth preparation can affect the strength of ceramic
veneers remains controversial. PURPOSE: This in vitro study evaluated fracture
load and mode of failure of ceramic veneers, with 4 tooth preparation designs,
that were bonded on extracted human maxillary central incisors. Identical
parameters were also measured on unrestored intact teeth for comparison. MATERIAL
AND METHODS: Fifty maxillary central incisors were randomly divided into 5 equal
groups. Each group was assigned a different tooth preparation design: (1) no
incisal reduction, (2) 2 mm incisal reduction without palatal chamfer (butt
joint), (3) 1 mm incisal reduction and 1 mm height palatal chamfer, (4) 4 mm
incisal reduction and 1 mm height palatal chamfer, and (5) unrestored (control).
Forty teeth were prepared to accommodate ceramic veneers of equal thickness and
incisocervical length. Stone dies were fabricated and veneers made from IPS
Empress ceramic. Ceramic veneers were bonded and all teeth mounted in phenolic
rings with epoxy resin. Fracture loads were recorded with a mechanical testing
machine. RESULTS: Mean fracture loads (SD) in kgf were as follows: group 1, 23.7
(6.11); group 2, 27.4 (9.63); group 3, 16.4 (3.44); group 4, 19.2 (6.18); and
group 5, 31.0 (10.38). Modes of failure were also analyzed for both ceramic
veneers and teeth. One-way ANOVA with multiple comparisons revealed 3 significant
subsets: groups 1-2-5, groups 4-1, and groups 3-4 (P <.05). Groups 1 and 2 had no
ceramic veneer fractures; group 3 had 3 ceramic veneer fractures, and group 4 had
6 ceramic veneer fractures. CONCLUSION: Groups 1 and 2 recorded the greatest
fracture loads that were comparable to an unrestored control.
PMID- 10668030
TI - Resin shear bond strength to porcelain and a base metal alloy using two
polymerization schemes.
AB - STATEMENT OF PROBLEM: Fractures in ceramometal restorations can occur and need to
be repaired because replacements are not an economic solution. PURPOSE: This
study evaluated the shear bond strengths of 4 porcelain repair systems (Metabond
C&B [ME], Silistor [SI], Clearfil Lustre [CL], and Scotchbond Multipurpose Plus
[SQ]) to a base metal alloy and porcelain in relation with the polymerization
shrinkage of a visible light-cured composite superstructure and compared with the
ceramometal bond strength (Vita VMK 68). MATERIAL AND METHODS: Thirty-two samples
were prepared for each bonding system: 16 for resin-metal bond strength test, and
16 for resin-porcelain bond strength test. For each group, bonding agent was
applied to 8 substructures and the resin superstructure was polymerized onto the
bonding agent; and for the remaining 8 specimens, prepolymerized resin
superstructures were bonded with bonding agent. All specimens were subjected to
500 cycles between 5 degrees C and 55 degrees C with 20 seconds dwell time. Tests
were performed in a mechanical testing machine with a 0.5 mm/min crosshead speed.
RESULTS: All materials showed an increase in shear bond strength when
prepolymerized resin superstructures were used. However, the effect of
polymerization shrinkage of resin superstructure was statistically significant
only for CL group (P <. 05). The highest metal-resin bond was obtained from ME
group with prepolymerized resin superstructures (35.27 +/- 2.40 MPa), and the
lowest value was obtained for the SI group in which resin superstructures were
polymerized in situ (8.71 +/- 1.03 MPa). The highest porcelain-resin bond was
obtained from SC group with prepolymerized resin superstructures (20.71 +/- 1.13
MPa) and the lowest was obtained from SI group (9.99 +/- 1.52 MPa). CONCLUSION:
Higher bond strength values were obtained with prepolymerized resin
superstructures compared to in situ polymerized superstructures. Metabond C&B
provided the best results for both prepolymerized and in situ polymerized resin
superstructure preparation techniques at the failures where metal was exposed.
The best results in situations in which the fracture is limited into porcelain
were obtained with the use of Scotchbond Multipurpose Plus material. However, a
variety of in vivo and in vitro tests are required before a final judgment is
made.
PMID- 10668031
TI - Evaluation of the dimensional changes and surface roughness of gold crowns cast
with rapidly prepared phosphate-bonded investment: a pilot study.
AB - STATEMENT OF PROBLEM: Accelerated bench-set and burnout schedules are used with
little knowledge of the effect acceleration has on clinical factors determining
casting success. PURPOSE: This pilot study investigated the effect of 2 rapid
mold preparation schedules on full crown castings by comparing size, margin
sharpness, and surface roughness. MATERIAL AND METHODS: Three groups of 10 crowns
were cast with a type III gold alloy. All crowns were nominally identical, only
their mold preparation schedules differed. Two groups used accelerated schedules;
the third group was cast using a conventional schedule. Group comparisons were
based on direct microscopic measurements of crown diameters (x50 magnification),
and surface roughness was measured. Margin sharpness was judged by amount of
marginal length lost in the axial direction as a result of the casting process.
RESULTS: Measured crown diameters, indexing size for the 3 groups, were not
significantly different. Crowns made with the conventional schedule had greater
surface roughness, and better margin sharpness or length. CONCLUSION: Crowns were
successfully cast using accelerated mold preparation techniques and considerable
time was saved, but a small loss of margin length or fineness was observed.
PMID- 10668032
TI - Microleakage of compomer class V restorations: effect of load cycling, thermal
cycling, and cavity shape differences.
AB - STATEMENT OF PROBLEM: Microleakage is an important problem with direct filling
restorations and an understanding of the factors that contribute to it is of
critical importance. PURPOSE: This study investigated the effect of thermal and
occlusal load cycling, and limited cavity preparation on microleakage of compomer
Class V restorations in vitro. MATERIAL AND METHODS: Class V cavities were
randomly prepared on the buccal and lingual surfaces of 32 recently extracted
molars and premolars and restored with Dyract compomer restorative system as per
the manufacturer's directions. Teeth were randomly assigned to 1 of 4 treatment
groups with 8 teeth in each group: (I) thermocycling only; (II) load cycling
only; (III) both thermocycling and load cycling; and (IV) no treatment. All teeth
were then immersed in 2% basic fuchsin solution for 24 hours. Dye penetration was
measured linearly using color photographic prints. ANOVA, comparisons between
means, and correlation were used to analyze the results. RESULTS: Thermocycling
and cavity preparation had a significant effect on microleakage, but load cycling
did not. Occlusal margins leaked more than the gingival margins. CONCLUSION:
Class V restorations demonstrated increased microleakage under the conditions of
thermal cycling and nonretentive cavity design. More microleakage occurred at
occlusal margins than at gingival margins. The effect of load cycling is
complicated by considerations of the types of stresses applied and the
restorative material response to such stresses.
PMID- 10668033
TI - Fracture toughness of resin-based luting cements.
AB - STATEMENT OF PROBLEM: The introduction of resin-modified glass ionomer cements
has expanded the choices of luting cements available to the clinician; however,
few independent studies are available on the fracture toughness of the currently
available resin-modified glass ionomer luting agents compared with the composite
cements. PURPOSE: This investigation evaluated the relative fracture toughness
(K(IC)) of 3 composite luting cements (Panavia 21, Enforce, and C&B Metabond), 3
resin-modified glass ionomer luting cements (Advance, Vitremer Luting, and Fuji
Duet), and a conventional glass ionomer luting cement (Ketac-Cem) at 24-hour and
7-day storage times. MATERIAL AND METHODS: K(IC) was determined by preparing
minicompact test specimens (n = 8) with introduced precracks. Specimens were
stored in distilled water at 37 degrees C + 2 degrees C until testing. Testing
was performed on an Instron testing machine at a displacement rate of 0.5 mm/min.
RESULTS: ANOVA (P <.001) and REGW Multiple Range Test (P <.05) demonstrated
significant differences among several of the cements tested. The mean fracture
toughness values of C&B Metabond at 24 hours and Enforce at both 24 hours and 7
days were significantly greater than use any of the other cements tested.
CONCLUSION: The resin-modified glass ionomer cements exhibited improved fracture
toughness when compared with the conventional glass ionomer; however, they were
still inferior to Enforce and C&B Metabond composite cements.
PMID- 10668034
TI - Shear bond strength of resin luting cement to glass-infiltrated porous aluminum
oxide cores.
AB - STATEMENT OF PROBLEM: Resin bonding surface treatment methods for conventional
silica-based dental ceramics are not reliable for glass infiltrated high alumina
content In-Ceram ceramics. PURPOSE: This study developed an alternative surface
treatment to improve resin bonding of glass-infiltrated aluminum oxide ceramic
blasting with diamond particles and then observed the efficiency of this
treatment. Material and methods. In-Ceram test specimens were prepared and
divided into 2 groups. All specimens were sandblasted with Al(2)O(3), and blasted
with diamond particles and 2 adhesive resins were applied. After bonding and
storage in humid conditions, shear bond strength values were measured with a
universal testing machine. Surface roughness and fracture interfaces were
determined with a perthometer and a SEM. RESULTS: The highest bond strength was
obtained on the samples blasted with diamond particles (group II). The
differences between the 2 groups and the 2 adhesive resin cements were both
statistically significant. CONCLUSION: Panavia-Ex cement exhibited higher bond
strength than Super-Bond cement. This higher bond strength was attributed to
ceramic oxide and ester bond and the mechanical properties of Panavia-Ex cement.
PMID- 10668035
TI - Survival of In-Ceram crowns in a private practice: a prospective clinical trial.
AB - STATEMENT OF PROBLEM: Prior reports on some all-ceramic crown systems have
indicated high failure rates through fracture. PURPOSE: This study prospectively
evaluated the survival of infiltrated alumina crowns (In-Ceram) in a private
practice. MATERIAL AND METHODS: All the In-Ceram crowns placed in a prosthodontic
practice since its introduction in 1990 were serially included. Patients were
recalled at 6 monthly intervals. Those who did not attend in the previous 6
months were contacted by telephone and a series of answers to standardized
questions recorded. The few patients who were lost to follow-up or who died were
removed from the study from the time of last contact. RESULTS: A total of 408
crowns in 107 patients were followed for periods from 1 to 86 months. As the 3
year data combined a meaningful period of service with a large sample size, these
data were focused on. The 3-year survival rate was 96% for a sample size of 223.
Three-year data indicated that core fracture and porcelain fracture occurred at
rates of approximately 0.6% and 0.3% per year, respectively. Otherwise sound
restorations were removed at a rate of approximately 0.3% per year for esthetic,
endodontic, or prosthetic reasons. Anterior crowns tended to have a slightly
higher 3-year survival rate (98%) than premolars or molars (94%). CONCLUSION:
Clinical failure rate of In-Ceram crowns was low. Crowns were lost because of
core fracture, porcelain fracture, and removal without failure. Failure tended to
be more common for molar and premolar crowns than for anterior crowns.
PMID- 10668036
TI - Biocompatibility of dental casting alloys: a review.
AB - STATEMENT OF PROBLEM: Dental casting alloys are widely used in applications that
place them into contact with oral tissues for many years. With the development of
new dental alloys over the past 15 years, many questions remain about their
biologic safety. Practitioners must choose among hundreds of alloy compositions,
often without regard to biologic properties. PURPOSE: This article is an evidence
based tutorial for clinicians. Concepts and current issues relevant to the
biologic effects of dental casting alloys are presented. SUMMARY: The single most
relevant property of a casting alloy to its biologic safety is its corrosion.
Systemic and local toxicity, allergy, and carcinogenicity all result from
elements in the alloy being released into the mouth during corrosion. Little
evidence supports concerns of casting alloys causing systemic toxicity. The
occurrence of local toxic effects (adjacent to the alloy) is not well documented,
but is a higher risk, primarily because local tissues are exposed to much higher
concentrations of released metal ions. Several elements such as nickel and cobalt
have relatively high potential to cause allergy, but the true risk of using
alloys containing these elements remains undefined. Prudence dictates that alloys
containing these elements be avoided if possible. Several elements in casting
alloys are known mutagens, and a few such as beryllium and cadmium are known
carcinogens in different chemical forms. Despite these facts, carcinogenic
effects from dental casting alloys have not been demonstrated. Prudent
practitioners should avoid alloys containing these known carcinogens. CONCLUSION:
To minimize biologic risks, dentists should select alloys that have the lowest
release of elements (lowest corrosion). This goal can be achieved by using high
noble or noble alloys with single-phase microstructures. However, there are
exceptions to this generality, and selection of an alloy should be made on a case
by-case basis using corrosion and biologic data from dental manufacturers.
PMID- 10668037
TI - Overview of articulation materials and methods for the prosthodontic patient.
AB - STATEMENT OF PROBLEM: Many methods and materials are available for registering
the centric relation position, with various degrees of accuracy. Once the centric
relation position is recorded, many instruments are available for cast
articulation. These articulators range from simple to complex devices that
generate different mandibular movements depending on the sophistication of the
instrument. PURPOSE: This review evaluated the methods and materials used to
record the centric relation position and eccentric maxillomandibular relations,
and to compare the articulators available for mounting casts. METHODS: A MEDLINE
search was completed (from 1966-present) along with personal searches of selected
journals to find additional publications that addressed these materials, methods
of registration, and available instrumentation. CONCLUSION: Potential
applications of this review are as follows: (1) to allow the reader to examine
the various methods for recording the centric relation position that have been
studied and described, and (2) to observe how the accuracy of recording materials
have changed over time. The reader will also realize the types of simple and
complex articulators that exist, along with the different degrees of simulated
mandibular movements that may be accomplished.
PMID- 10668038
TI - Surgical guide for dental implant placement.
AB - Restorative problems with less than desirable implant placement can be
challenging. A procedure is presented for the fabrication of a surgical guide
stent that dictates placement of dental implants. This surgical guide can enhance
implant placement in an efficient and acceptable manner so that final
restorations can be properly contoured and esthetic.
PMID- 10668039
TI - Fabrication of a radiographic and surgical stent for implants with a vacuum
former.
PMID- 10668040
TI - Frontal lobe in vivo (31)P-MRS reveals gender differences in healthy controls,
not in schizophrenics.
AB - Phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS) has gained much
interest in schizophrenia research in recent years since it allows the non
invasive measurement of high-energy phosphates and phospholipids in vivo.
However, until now only differences in metabolite concentrations between certain
brain areas of schizophrenic patients and healthy controls have been examined. We
investigated the influence of gender on the concentrations of different
phosphorus compounds. For this purpose, well-defined volumes in the frontal lobe
of 32 healthy controls and 51 schizophrenic in-patients were examined with an
image selected in vivo spectroscopy (ISIS) sequence on a whole-body scanner at
1.5 T. Healthy females exhibited increased values of inorganic phosphate (P(i))
and decreased values of phosphocreatine (PCr) in comparison to their male
counterparts. In schizophrenic patients such gender differences were not present.
Thus, the results can be interpreted in the sense that frontal energy demanding
processes are enhanced in female compared to male healthy volunteers;
schizophrenia seems to reduce these gender differences.
PMID- 10668041
TI - Magnetization transfer attenuation of creatine resonances in localized proton MRS
of human brain in vivo.
AB - To assess putative magnetization transfer effects on the proton resonances of
cerebral metabolites in human brain, we performed quantitative proton magnetic
resonance spectroscopy (2.0 T, STEAM, TR/TE/TM = 6000/40/10 ms, LCModel data
evaluation) of white matter (7.68 mL, 10 healthy young subjects) in the absence
and presence of fast repetitive off-resonance irradiation (2.1 kHz from the water
resonance) using a train of 100 Gaussian-shaped RF pulses (12.8 ms duration, 120
Hz nominal bandwidth, 40 ms repetition period, 1080 degrees nominal flip angle).
A comparison of pertinent metabolite concentrations revealed a magnetization
transfer attenuation factor of the methyl and methylene resonances of creatine
and phosphocreatine of 0.87 +/- 0.05 (p < 0.01). No attenuation was observed for
the resonances of N-acetylaspartate and N-acetylaspartylglutamate, glutamate and
glutamine, choline-containing compounds, and myo-inositol. The finding for total
creatine is in excellent agreement with data reported for rat brain. The results
are consistent with the hypothesis of a chemical exchange of mobile creatine or
phosphocreatine molecules with a small immobilized or 'bound' pool.
PMID- 10668042
TI - Measurement of the extracellular pH of solid tumours in mice by magnetic
resonance spectroscopy: a comparison of exogenous (19)F and (31)P probes.
AB - Precise measurement of pH(e) in vivo may be of clinical value for both diagnosis
and selection of therapy. pH(e) measurements made by the (31)P probe 3
aminopropylphosphonate (3-APP) were compared with those made by the (19)F probe,
3-[N-(4-fluor-2-trifluoromethylphenyl)-sulphamoyl]-propionic acid (ZK-150471) in
three solid tumour types, human HT29 xenografts, murine RIF-1 fibrosarcomas and
Lettre tumours grown subcutaneously in mice. No significant differences were
observed when probe measurements of pH(e) were compared at 20-60 min post
administration, although very low pH(e) values (ca. 6.0) were recorded in two out
of eight Lettre tumours by ZK-150471. The more rapid pH(e) measurements possible
using ZK-150471 showed that during the first 20 min post-administration
significant increases occurred in pH(e) which were greatest in the more necrotic
tumours. Since isolated cell experiments showed that ZK-150471 was non-toxic and
did not enter the cells, this early increase in pH(e) may reflect gradual
penetration by ZK-150471 of the reportedly alkaline necrotic space in the
tumours. The wide chemical shift range, improved signal-to-noise and absence of
signal overlap allowed a more rapid and precise measurement of pH(e) by ZK-150471
compared to 3-APP. These characteristics suggest that ZK-150471 is currently the
preferred pH(e) probe for non-invasive MRS.
PMID- 10668043
TI - Serial magnetic resonance diffusion and hemodynamic imaging in a neonatal rabbit
model of hypoxic-ischemic encephalopathy.
AB - Dynamic changes in relative cerebral blood volume (rCBV) and apparent diffusion
coefficient (ADC) were investigated, using high speed magnetic resonance imaging
(MRI) in an acute neonatal rabbit model of hypoxic-ischemic encephalopathy (HIE).
Serial rCBV imaging used a magnetic susceptibility blood pool contrast agent.
Interleaved ADC and rCBV images were acquired with 9 s temporal resolution.
Rabbits received unilateral common carotid artery (CCA) ligation followed by
hypoxia. rCBV increased bilaterally within 1-2 min after the onset of hypoxia. A
biphasic ADC decline was observed: a slowly declining phase (84 +/- 18% of
baseline) followed by a rapid, focal drop to 55 +/- 8% of baseline in the
ipsilateral cortex, which was paralleled by a rapid focal rCBV drop to 70 +/- 17%
of baseline. ADC decline generally began in a small region of ipsilateral cortex
and spread over the ipsilateral cortex, ipsilateral subcortical tissue and
contralateral cortex. The initial ADC drop usually preceded the initial rCBV drop
by approximately 60 s, however at later timepoints rCBV decline sometimes
preceded ADC decline. Upon normoxia, rCBV recovered to about baseline values
while ADC recovered to baseline or above. This method provides a sensitive means
of non-invasively visualizing acute hemodynamic- and metabolic-related changes in
HIE with good temporal and spatial resolution.
PMID- 10668044
TI - Myocardial high-energy phosphate metabolism in heart transplant patients is
temporarily altered irrespective of rejection.
AB - A reliable, sensitive, non-invasive alternative for transvenous endomyocardial
biopsy in detecting cardiac allograft rejection is desirable for optimal
management of heart transplant patients. To establish whether (31)P magnetic
resonance spectroscopy can become a non-invasive tool for detecting cardiac
allograft rejection, the cardiac high-energy phosphate metabolism of human heart
transplants was serially examined in 13 patients by means of (31)P MRS from post
operative day 13 to day 294, and compared with histologic evaluation of
endomyocardial biopsies. Biopsy scores of 2 or higher, according to the Working
Formulation criteria of Billingham et al., were considered to indicate rejection.
Logistic regression, which was corrected for differences between the individual
patients and the time after transplantation, showed no significant correlation
between the occurrence of histologically detected rejection and the PCr:ATP
ratio. However, using an analysis of variance, the PCr:ATP ratios of non
rejecting cases obtained within 50 days after transplantation (mean: 27 +/- 11
days) appeared to be significantly different from those obtained after post
operative day 50 [0.95 +/- 0.17 (n = 25) vs 1.17 +/- 0.17 (n = 32), mean +/- SD;
p < 0.01]. No significant difference was observed between the PCr:ATP ratios
obtained 100 days after transplantation (mean: 162 +/- 52 days) and the PCr:ATP
ratios in the hearts of healthy volunteers [1.18 +/- 0. 18 (n = 19) and 1.23 +/-
0.17 (n = 6), mean +/- SD, respectively; p = 0.55]. The PCr:ATP ratio in
transplanted human hearts is not a sensitive indicator for the detection of early
acute human cardiac allograft rejection. This may be due to a temporarily altered
high-energy phosphate metabolism early after transplantation irrespective of
rejection.
PMID- 10668045
TI - Diffusion- and perfusion-weighted MR imaging of transient focal cerebral
ischaemia in mice.
AB - Temporary focal ischaemia was induced in wild-type C57Black/6 mice by thread
occlusion of the middle cerebral artery (MCA). Recirculation was started after 60
min and maintained for 24 h, after which the mouse brain was frozen in situ.
Development of the cerebral infarct was monitored by diffusion-, perfusion- and
T(2)-weighted magnetic resonance imaging (MRI) during ischaemia, during the early
reperfusion period of 90 min, and at 24 h after reperfusion. Ischaemia caused a
marked reduction of the perfusion signal intensity and of the apparent diffusion
coefficient (ADC) of tissue water in the ipsilateral MCA territory. In sham
operated control animals ADC remained unchanged. Hemispheric lesion volume after
1 h MCA occlusion was 53 +/- 6% (n = 6), as defined by an ADC decrease of more
than 20%. Recirculation reduced hemispheric lesion volume to only 27 +/- 13%,
while there was a trend towards secondary lesion growth at 24 h. Post-ischaemic
recovery of perfusion was slow, heterogeneous and incomplete. A region-of
interest analysis showed only partial and transient recovery of the ADC,
particularly in the dorsolateral cortex and lateral caudate putamen, which may be
explained by inadequate reperfusion in these regions. Detailed MRI studies of
cerebral ischaemia and reperfusion may now also be performed in the transgenic
mice.
PMID- 10668046
TI - Abnormal liver metabolism in cancer patients detected by (31)P MR spectroscopy.
AB - There is accumulating evidence indicating that the presence of malignant disease
is accompanied by profound changes of liver metabolism in the cancer-bearing
host. We previously reported [P. C. Dagnelie, J. D. Bell, -S. C. R. Williams, T.
E. Bates, P. D. Abel and C. S. Foster, Br. J. Cancer 67, 1303-1309 (1993)] marked
(31)P MRS-detected alterations in phosphorylation status as well as in
phospholipid and glucose metabolism in the liver of rats bearing Dunning prostate
tumours. The aim of the present study was first to define abnormalities in liver
metabolism in patients with a distant malignancy using (31)P MRS, and second to
explore the value of including long-TR sequences in clinical (31)P MRS studies of
the liver. Liver metabolite levels were expressed relative to total MR-detectable
phosphate. In weight-losing (WL, n = 10), but not in weight-stable (WS, n = 13)
cancer patients, liver phosphomonoester (PME) levels were significantly elevated,
whereas phosphodiester (PDE) levels were reduced when compared with age-matched
healthy subjects (n = 12). The TR 20:1 s ratio of PDE was increased in WS and WL
cancer patients, suggesting longer T(1). At TR 20 s, but not at TR 1 s, ATP
levels were significantly reduced in in WS and WL cancer patients compared with
healthy subjects; similarly, P(i) levels were reduced in WL patients at TR 20 and
5s, but not at TR 1 s. ATP:P(i) ratios were unchanged regardless of TR. pH values
increased in the order: healthy < cancer-WS < cancer-WL. The PME chemical shift
had significantly moved downfield in cancer patients, reflecting increased
contributions from glycolytic/gluconeogenic intermediates. The observed changes
in PME are consistent with previous reports suggesting increased gluconeogenesis
in the liver of patients with a distant malignant tumour. Furthermore, our data
support the use of including long-TR sequences in clinical (31)P MRS liver
studies.
PMID- 10668047
TI - Non-P(i) buffer capacity and initial phosphocreatine breakdown and resynthesis
kinetics of human gastrocnemius/soleus muscle groups using 0.5 s time-resolved
(31)P MRS at 4.1 T.
AB - High-time-resolution (0.5 s) (31)P MRS has been used to evaluate the initial
phosphoreatine (PCr) breakdown and resynthesis kinetics, to calculate the non
P(i)(/non-bicarbonate) buffer capacity (betanon-P(i)(/non-bicarb)), and to
calculate the constant relating the change in intracellular pH to the muscle's
H(+) efflux rate (lambda). The slope of PCr vs time demonstrates that a slope
calculated using the first 10 s of recovery underestimates initial PCr recovery
rates by up to 56%. A 1-2 s time window is needed to produce a slope that is
statistically equivalent to the slope measured using a 0.5 s time window (p =
0.008, one-way RM-ANOVA, Student-Newman-Keuls multiple comparison test). In
addition, there was no delay or acceleration in PCr recovery after a 90 s maximum
voluntary contraction (MVC) in normal subjects. This demonstrates that oxidative
metabolism is occurring at the end of a 90-s MVC in normal individuals. Fitting
recovery data has determined that betanon-P(i)(/non-bicarb) = 24.3 +/- 5.4 slyke
(mmol/L/pH unit) and that lambda = 0.129 +/- 0.077 mM/(ph s) for human
gastrocnemius/soleus muscle. betanon-P(i)(/non-bicarb) is in agreement with
measurements in cat biceps, cat soleus and rat gastrocnemius muscles.
PMID- 10668048
TI - Complications of nonlinear echo time spacing for measurement of T (2).
AB - Some consequences of using nonlinear echo spacing in multi-echo sequences for
measuring T(2) were investigated under the conditions of imperfect RF refocusing
or diffusion losses. Although using nonlinear echo spacing has previously been
shown to estimate T(2) more accurately, the effect of such spacing is shown to be
detrimental when sequences use imperfect RF refocusing pulses. The progressive
loss of transverse magnetization that results from imperfect refocusing will
alter estimates of T(2) regardless of the echo spacing. However, when the echo
spacing is nonlinear, this loss of magnetization also introduces non-mono
exponential T(2) components. Such an effect may distort relative amplitudes of a
multi-component T(2) distribution or generate multiple T(2) components where they
do not exist. Diffusion through inhomogeneous magnetic fields results in a
similar loss of magnetization and T(2) distortion. For these reasons, the use of
nonlinearly spaced echoes, while providing in theory a more appropriate sampling
of transverse relaxation, is not appropriate for many imaging situations.
PMID- 10668049
TI - Systemic alterations in phospholipid concentrations of blood plasma in patients
with thyroid carcinoma: an in-vitro (31)P high-resolution NMR study.
AB - In this study in-vitro (31)P high-resolution NMR spectroscopy of human blood
plasma was optimized to obtain absolute concentrations of the major
plasmaphospholipids: phosphatidylethanolamine plus sphingomyelin (PE + SM), 1-
and 2-acyl-lysophosphatidylcholine (LPC1 and LPC2), phosphatidylinositol (PI) and
phosphatidylcholine (PC). Plasma spectra of 33 patients with thyroid carcinoma
were acquired at 121.49 MHz using a 300 MHz spectrometer. The patients were
rendered hypothyroid (TSH >30 mU/l) in preparation for a whole-body scintigraphy.
The whole-body scintigraphy showed tumour tissue or metastases in 16 patients
(group C). Owing to an inconclusive whole-body scintigraphy, 17 patients were
classified as being in remission (group B). After levothyroxine substitution 14
patients of group B were measured in euthyroidism too (group D). Besides these
sub-groups, there was a control group made up of 23 healthy volunteers (group A).
Group B showed significantly higher PE + SM and PC concentrations than group C
(0.59 +/- 0.02 mmol/l PE + SM in B vs 0.48 +/- 0.02 mmol/l in C; 2.1 +/- 0.1
mmol/l PC in B vs 1.6 +/- 0.1 mmol/l in C). In comparison with group D higher
concentrations of the phospholipids PE + SM and PC as well as PI were found in
group B (0.59 +/- 0.02 mmol/l PE + SM in B vs 0.48 +/- 0.03 mmol/l in D; 0.074 +/
0.005 mmol/l PI in B vs 0.046 +/- 0.004 mmol/l in D; 2.1 +/- 0.1 mmol/l PC in B
vs 1.6 +/- 0.1 mmol/l in D). The data indicate that under the condition of
hypothyroidism only patients in remission (group B) show significantly increased
phospholipid concentrations, whereas the values in patients with remaining tumour
tissue (group C) do not differ from those of the reference groups A and D. This
finding is interpreted as an interference between the hormonal status and the
systemic effects of cancer.
PMID- 10668050
TI - 31P MRS measurement of mitochondrial function in skeletal muscle: reliability,
force-level sensitivity and relation to whole body maximal oxygen uptake.
AB - The reliability, relation to whole-body maximal oxygen uptake (VO(2max)), and
force-level sensitivity of (31)P MRS markers of mitochondrial function were
studied in 39 normal-weight women. Following 90 s isometric plantar-flexion
exercises at 45, 70 and 100% of maximum voluntary contraction, skeletal muscle
mitochondrial function was determined from the phosphocreatine recovery time
constant (TC(PCr)), the ADP recovery time constant (TC(ADP)), and the rate of
change in PCr during the first 14 s of recovery (OxPhos). VO(2max) was measured
on a treadmill. Test-retest measurements were obtained in a subset of seven
women. Overall, TC(PCr), TC(ADP) and OxPhos were reproducible for all exercises
(coefficients of variation = 2.3-19.3%). With increasing force-level, TC(PCr) was
prolonged (29.0 +/- 8.2, 31.9 +/- 9.0 and 35.4 +/- 9.5 s), OxPhos was increased
(0.159 +/- 0.081, 0.247 +/- 0.090 and 0.310 +/- 0.114), and TC(ADP) was shortened
(22.4 +/- 7.9, 21.3 +/- 6.2, and 19.5 +/- 6.7; p < 0.01). All MRS markers of
mitochondrial function were correlated with VO(2max) (r = 0.41-0.72; p < 0.05).
These results suggest that measurements of TC(PCr), TC(ADP) and OxPhos yield
reproducible results that correlate with whole-body VO(2max) and that vary in
force-level sensitivity.
PMID- 10668051
TI - On the reliability of quantitative clinical magnetic resonance spectroscopy of
the human brain.
AB - The reliability of a single-voxel, localized proton magnetic resonance
spectroscopy protocol suitable for clinical studies was investigated by means of
in vitro, single-subject in vivo and multi-subject in vivo examinations of
healthy adults aged from 19 to 67 years. The study was performed at 1.5 T using a
standard quadrature head coil and a single voxel PRESS sequence (in vitro TR/TE =
1500/30 ms, in vivo TR/TE=2000/35 ms). Eighty-four in vitro and 30 single-subject
examinations were statistically evaluated after quantification, including the
calculation of the coefficients of variations (CV) for choline (Cho), creatine
(Cr), myo-inositol (mI), lactate (Lac), N-acetyl-aspartate (NAA) and unresolved
glutamine, glutamate and GABA (Glx). The CVs for absolute concentrations of the
main metabolites Cho, Cr and NAA, ranged from 3.3% (3.8) to 4.0% (6.4%) (the in
vivo results are given in brackets). Multi-subject CVs of absolute concentrations
for Cho, Cr and NAA ranged from 7.6% to 15.0%. CVs of relative in vivo
concentrations were found to be higher than CVs of absolute concentrations. Due
to the better reproducibility of intra-individual absolute in vivo
concentrations, cross-over studies using institutional units are recommended.
PMID- 10668052
TI - Simultaneous detection of changes in perfusion and BOLD contrast.
AB - A new functional magnetic resonance imaging (fMRI) technique for simultaneous
detection (SIDE) of changes in perfusion and blood oxygenation level dependent
(BOLD) contrast is described. Perfusion contrast is generated by using
magnetically labeled endogenous water proton spins as a freely diffusible tracer.
A single slice-selective inversion pulse is combined with dual echo echo-planar
imaging to generate a spin-echo (SE) image sensitive to changes in perfusion and
a gradient-echo (GE) image sensitive to changes in both perfusion and BOLD
contrast. The SIDE technique was applied to detect functional changes induced by
a visual search task. A theoretical analysis is provided to calculate
quantitative maps of changes in cerebral blood flow (DeltaCBF) and effective
transverse relaxation time (DeltaT(2)*) from the corresponding signal changes in
the SE and GE images. Since SE an GE images are generated from the same
longitudinal magnetization, no errors due to spatial or temporal mismatch can
arise in the quantification of DeltaCBF and DeltaT(2)*.
PMID- 10668053
TI - Regional brain activation by bicuculline visualized by functional magnetic
resonance imaging. Time-resolved assessment of bicuculline-induced changes in
local cerebral blood volume using an intravascular contrast agent.
AB - Functional magnetic resonance imaging (fMRI) has been applied to study rat focal
brain activation induced by intravenous administration of the GABA(A) antagonist
bicuculline. Using magnetite nanoparticles as a blood pool contrast agent, local
changes in cerebral blood volume (CBV) were assessed with high temporal (10 s)
and spatial (0.35 x 0.6 mm(2)) resolutions. Upon infusion of the bicuculline
region-specific increases in CBV have been observed, suggesting CBV to reflect
brain activity. During the first 2 min, the signal increases were predominant in
the cortex, followed by increases in other brain areas, such as the caudate
putamen, thalamus and cerebellum. Ten minutes after the start of infusion, a
dominant response was observed in the thalamus, while in the caudate putamen a
biphasic response pattern was seen. The magnitude of the signal responses in all
brain regions was dependent on the dose of bicuculline and, in general, matched
the known distribution of GABA(A) binding sites. This study suggests that
pharmacological fMRI, displaying brain function at the highly specific level of
drug-receptor interaction, should foster our understanding of normal and
pathological brain function.
PMID- 10668054
TI - Child survivors of parental death from cancer or suicide: depressive and
behavioral outcomes.
AB - Depressive symptoms, social competence, and behavior problems of prepubescent
children bereaved within 18 months of parental death from cancer (57 families, 64
children) or suicide (11 families, 16 children) were compared. Most children
reported normative levels of depressive symptoms. Children whose parents died
from suicide, compared with those whose parents died from cancer, reported
significantly more depressive symptoms, involving negative mood, interpersonal
problems, ineffectiveness, and anhedonia. Parental reports of children's
competence and behavior were similar to a normative sample of children and did
not differ between the children bereaved by parental cancer or suicide.
Additional research should focus on other factors, such as family
psychopathology, stresses, and impact of stigma, which may influence the course
of bereaved children.
PMID- 10668055
TI - Promoting psychological well-being in the face of serious illness: when theory,
research and practice inform each other.
AB - This article describes the interplay among theory, research and practice
regarding the maintenance of psychological well-being during serious illness. The
ideas emerged from two independent lines of work, one that evolved through
clinical practice within the medical model, the other that evolved through theory
and field research within a behavioral science model. Each of these lines of work
independently points to the importance of focusing on psychological well-being
and the coping processes that support it, as a complement to the traditional
focus in both the medical and behavioral sciences on psychiatric symptoms. This
article describes a theoretical framework for the discussion of psychological
well-being during serious illness. Then, this framework is used to define
variables that research indicates contribute specifically to psychological well
being during serious illness, and finally, based on theory and research, a
therapeutic program is described for patients with serious illness. The goal of
this paper is to encourage researchers and clinicians to give as much attention
to the development and maintenance of psychological well-being in the face of
serious illness as they do to the etiology and treatment of psychiatric symptoms.
PMID- 10668056
TI - Negative and positive influences of social support on depression in patients with
head and neck cancer: a prospective study.
AB - Patients with head and neck cancer have to cope not only with a life threatening
diagnosis, but also with an altered facial appearance and the loss or impairment
of important functions as a result of treatment. As a consequence they are prone
to psychosocial problems. Social support might influence their ability to adapt
to the illness and its treatment. The aim of this prospective study is to examine
the influence of different aspects of social support on the depressive
symptomatology in head and neck cancer patients treated with surgery and/or
radiotherapy. Patients completed a questionnaire relating to available and
received support, the extent of the social network, depressive symptoms, and
general health complaints before and 6 months after treatment. Received support
was found to be associated with more depressive symptomatology at baseline and
available support led to less depressive symptomatology. The relationship between
social support and depressive symptoms was especially apparent in patients with
few general health complaints. Whereas the availability of support seemed to be
beneficial regardless of the situation, the effect of received support was
equivocal. The provision of support should be tailored to the needs of the
individual patient.
PMID- 10668057
TI - Cisplatin-based therapy: a neurological and neuropsychological review.
AB - The present paper reviews research in the area of the broad-spectrum
chemotherapeutic agent cisplatin (cis-diamminedichloro-platinum II) and examines
the implications for clinical neuropsychology arising from the neurological
disruption associated with cisplatin-based therapy. The paper begins with a brief
review of cisplatin treatment in terms other than survival alone, and examines
the side-effects and the potential central nervous system (CNS) dysfunction in
terms of neurological symptoms and concomitant implications for neuropsychology.
Two main implications for clinical neuropsychology arising from cisplatin therapy
are identified. First, cisplatin therapy impacts upon the psychological well
being of the patient, particularly during and in the months following treatment.
It is suggested that during this time, a primary role for neuropsychology is to
focus upon the monitoring and the active enhancement of the patient's social,
psychological and spiritual resources. Second, with regard to neurocognitive
changes, the review suggests that (1) neurocognitive assessment may not yield
stable results within 8 months following treatment and (2) while perceptual,
memory, attentional and executive dysfunction may be predicted following
cisplatin treatment, little systematic research has been carried out to
investigate such a possibility. Future research might profitably address this
issue and also specifically examine the effects of low dosage cisplatin-based
therapy and the effects of recently developed neuroprotective agents. Finally,
there is some evidence to suggest that women may be more susceptible to
neurotoxicity during cisplatin therapy, but no gender-related cognitive effects
are reported in the cisplatin literature. Future research could usefully
investigate gender differences in association with cisplatin chemotherapy.
PMID- 10668058
TI - Using beliefs and magical thinking to fight cancer distress-a case study.
AB - This case relates to the way in which a young patient developed serious
difficulties in coping with her life in the years following a successful bone
marrow transplant. By means of an illustrative metaphor, she revealed her
existential position and the way in which she attempted to deal with her anxiety.
Being diseased implied that life's order was replaced by disorder and a loss of
basic trust. She tried to re-establish order by establishing beliefs that
attributed specific regularities to life, and to influence the risk of recurrence
by living according to these beliefs. Unfortunately, this meant that she had to
tread a very thin line over a course mined with anxiety and eventually, she
became a prisoner of her own creation. The author claims that we can learn from
this case, as it clearly illustrates psychological dimensions commonly seen in
cancer patients: the way anxiety is related to disorder and the way patients try
to regain control of their lives through constructing belief-systems. The case
also features a discussion of how we, as clinicians, may be able to help these
patients.
PMID- 10668059
TI - A pilot study of interpersonal psychotherapy by telephone with cancer patients
and their partners.
AB - A single-arm pilot study explored the feasibility of adapting in Interpersonal
Psychotherapy (IPT) by telephone to reduce psychological distress and to enhance
coping during cancer treatment. Therapy focuses on role transitions,
interpersonal conflicts, and grief precipitated by cancer. Breast cancer patients
receiving high-dose chemotherapy received weekly sessions with a psychologist
throughout chemotherapy and for 1 month afterwards. Patients could invite one
'partner' to receive individual telephone IPT. Psychosocial functioning was
assessed using standardized measures at study entry, after chemotherapy, and
following telephone IPT. Accrual and participation supplied evidence of
feasibility: 14 patients and 10 partners were recruited, 82.5% of those eligible.
Patients had a mean of 16 sessions; partners had a mean of 11. Participants rated
their satisfaction with the program between 'good' and 'excellent'. A test of the
efficacy of telephone IPT requires a larger, randomized trial. In order to
standardize the intervention, a treatment manual was developed. This study
indicated the importance of outreach to family members as well as to cancer
patients, intensive patient education about oncology treatment and the medical
care setting, and psychosocial services that continue after cancer treatment has
been completed.
PMID- 10668060
TI - The psychosocial experience of women treated for breast cancer by high-dose
chemotherapy supported by autologous stem cell transplant: a qualitative analysis
of support groups.
AB - Autologous bone marrow transplantation (AuBMT) is probably among the most
aggressive of physical treatments endured by cancer patients. High-risk breast
cancer patients who choose this therapy face prolonged, agonizing and life
threatening interventions that are no less arduous than confronting the malignant
disease itself. The study, which aimed to broadening our understanding of the
psychosocial impact and the implications of AuBMT, presents a protocol analysis
of group support intervention in 45 recipients (eight to ten women in five
groups). The sessions were held at the Transplant Department at the Chaim Sheba
Medical Center. The contribution of group support to the healing process was
examined. The findings show that recovery was affected by a wide range of
psychosocial factors, specifically highlighting the impact of transplantation and
survival on five domains, viz. physical, psychological/emotional, vocational,
social and family/spousal intimacy. Illness and treatment management is also
discussed. The support generated by the group, both individually and
collectively, was found to contribute significantly to the spectrum of resources
available to the participants.
PMID- 10668061
TI - Stability and change in posttraumatic stress disorder symptoms following breast
cancer treatment: a 1-year follow-up.
AB - While some recent research has examined the prevalence and severity of
posttraumatic stress disorder (PTSD)-like symptoms following cancer treatment, no
research has examined temporal change or stability in these symptoms in cancer
survivors. Female breast cancer survivors (n=46) participated in an initial
telephone interview and a follow-up interview 12 months later. PTSD symptoms
associated with breast cancer were assessed using the PTSD Checklist-Civilian
version (PCLC). In general, PTSD symptoms in this population did not diminish
over time. While group analyses indicated that PCLC-total and subscale scores
were stable across the two assessments, analyses of PCLC scores indicated that
many patients exhibited fairly large (>0.5 S.D.) increases and/or decreases in
PCLC-total or subscale scores. Some evidence suggested that decreases in PCLC
scores between the two study assessments were associated with greater social
support and experience of fewer traumatic stressors prior to breast cancer
diagnosis. Most significantly, the research suggested that women with greater
PTSD symptoms at the initial interview were less likely to participate in the
follow-up interview. Implications of this for research and clinical management of
PTSD in this population are discussed.
PMID- 10668062
TI - Development of a scale to measure psychosocial concerns of Mexican women with
advanced cancer.
AB - This descriptive study was undertaken to explore the perceptions and attitudes of
143 women (mean age+/-51) with advanced cancer. Outcome measures were the
Perceptions and Attitudes Scale (PAS), a 65-item instrument validated as part of
the study, and the Karnofsky Performance Status Scale. Internal consistency
(Cronbach alpha) and factor analytic techniques (principal component and
orthogonal rotation) were performed. The scale has an internal consistency of 0.
79. Factor analysis revealed six factors which explained 39.6% of the variance
(1) loneliness; (2) family and social sphere; (3) limitations and dependence
conditions; (4) perceptions about their lives; 5) perceptions about their health
and pain; and (6) perceptions of pain and anguish. These results point out the
necessity of a multivariate approach to women with advanced cancer.
PMID- 10668063
TI - Remission of chemotherapy-induced emesis with concurrent olanzapine treatment: a
case report.
PMID- 10668064
TI - S. P. Cotton, E. G. Levine, C. M. Fitzpatrick, K. H. Dold and E. Targ, 'Exploring
the relationships among spiritual well-being, quality of life, and psychological
adjustment in women with breast cancer'. psycho-oncology 8(5) 1999, 429-438
AB - The original article to which this Erratum refers was published in Psycho-Ocology
8(5) 1999, 429-438.
PMID- 10668065
TI - [Seroprevalence of helicobacter pylori infection in the republic of Argentina:
influence of age, sex, socioeconomic level, geographical area, and health
infrastructure. Multicenter study by the Club Argentino del Estomago y Duodeno].
AB - Helicobacter pylori (Hp) infection affects almost half of the world population,
it is almost a pandemia, and has been associated to poverty in underdeveloped
countries. The Club Argentino del Estomago y Duodeno decided to fulfill the lack
of information upon this subject in Argentina designing a seroprevalence,
multicentric, prospective study performed in voluntary adults donors in blood
banks and in children seen during normal growth controls. Seven hundred and
nineteen individuals were evaluated, 645 of them were included: 178 children (age
0-18 years) and 467 adults. In all cases a serological IgG Hp test (Flex-Pack
Abbott) was performed and an epidemiological questionnaire was completed by a
physician. General prevalence of Hp infection was 44.8% of individuals. In the
paediatric population prevalence was 15.7% and in adults 55.9%. The highest
prevalence was observed in the fifth decade: 64%. In concordance with other
similar studies carried out in different countries, we may conclude that the risk
of acquisition of Hp infection is directly related to age, area of residence,
social-economical status, sanitary facilities, and educational level reached.
Even though the prevalence of Hp infection in Argentina is intermediate between
highly developed and underdeveloped countries, the number of people infected is
very high and the incidence of Hp-associated pathologies in the future represents
a formidable task for gastroenterologists and sanitary authorities.
PMID- 10668066
TI - [Moderating action of celiac block in experimental pancreatitis in the dog].
AB - BACKGROUND: Pancreatic ischemia seems to be responsible of transition from
edematous to hemorrhagic forms in acute pancreatitis. (AP) Sympathetic system
vasoconstriction, through celiac plexus play an important role in the
pathogenesis of acute pancreatitis. OBJECTIVE: Determinate the effects of
anesthetic celiac blockade in an experimental model of AP. METHODS: Distal
pancreatectomy and intraductal injection of autologous bile in 28 mongrel dogs.
Blockade of celiac plexus with bupivacaine in the experimental group B.
Anatomopathologic examination after 72 hours. RESULTS: Experimental group B
developed milder forms of AP, while the control group A developed severe forms.
CONCLUSIONS: Results suggest that celiac plexus blockade with bupivacaine may
prevent the development of necrohemorrhagic forms of PA in a canine model.
PMID- 10668067
TI - [Intraepithelial enteroendocrine cells in cecum and appendix from ovoalbumin
sensitized rabbits].
AB - Intraepithelial enteroendocrine cells (IEC) produce peptides which influence
motility, secretion and absorption of nutrients. Recently the role of these cells
in the immune mucosal system is under study. The aim of the present study was to
evaluate the modifications in number of IEC in cecum and appendix from Ovalbumin
(OVA) sensitized rabbits. Twenty adult New Zealand rabbits were separated in two
groups: Group 1 (G1 = 10) not sensitized normal control. Group 2 (G2 = 10) were
sensitized twice intraperitoneally with 70 mg OVA and 30 mg ALUM/ml (aluminium
hydroxide). Anti OVA specific IgE was evaluated by means of PCA test (passive
cutaneous anaphylaxis). Samples form cecum and appendix were fixed in buffered
formaldehyde 10%, paraffin embedded and stained with anti-Chromogranin A for
neuroendocrine cells. 400 high power fields were counted in each animal, referred
as IEC/100 enterocytes. In cecum surface epithelium and crypt were considered.
Surface epithelium, deep crypts and superficial crypts were evaluated in
appendix. Results showed in cecum in G1:1,6 IEC/100 enterocytes in surface
epithelium and 3/100 in crypts; G2 6 IEC/100 in surface epithelium and 12/100 in
crypts. The difference between G1 and G2 was statistically significant (p <
0.05). In appendix surface epithelium from G1 showed 5.2/100 while G2 5.4/100.
Superficial crypts 8.5 (G1) and 11.3 (G2) (p < 0.05) and deep crypts 4.9 (G1) and
8.5 (G2) (p < 0.01). The results showed that OVA-sensitized animals presented
increment in the number of IEC in surface epithelium and crypts which may
indicate a relationship between these cells and rabbit mucosal immune system.
PMID- 10668068
TI - [Cancer of the esophagus and stomach: 3-year evaluation].
AB - Esophagus cancer has a very bad pathological prognosis. Risk factors considered
are: smoking consumption and deficiency of vitamins A and C. The mortality rates
of cancer of the stomach vary notably according to geographic region. Factors
such as genetics, races, smoking, socioeconomic conditions are some of stomach
cancer development. 646 symptomatic patients were studied in the gastroenterology
unit at. J.M. Cullen hospital. Histopathologically, 22 (3.3%) cancer of the
esophagus and 13 (2%) cancers of stomach were detected. All esophagus cancers
were squamous cells; 82% were males and 18% females. 50% were located on the
middle third zone. 92.3% of stomach cancers were adenocarcinoma; 83% were males
and 17% females. A 50.8% were located in corporo-fundic zone. All the cancers
both of the esophagus as well as of the stomach, were in the advanced phase. The
cancer of esophagus has appeared most frequently among cancers of the tract in
our hospital, with significant difference among province and national registers.
PMID- 10668069
TI - [Vascular ectasias of the gastric antrum as the cause of chronic digestive
hemorrhage. Presentation of a case].
AB - Digestive hemorrhages are one of the syndromes, that frequently attracts the
attention of the gastroenterologist-endoscopist. Sometimes it's not evident
during upper endoscopy study and course with a contrast radiological scan. In the
last years a vascular pathology has been seen which is responsible of high
digestive hemorrhages. It is manifested by melaena and is originated by vascular
ectasias, which are vascular dilatations present in the stomach or right colon
during various accompanying pathologies like hepatic cirrhosis with portal
hypertension, cardiac valvulopaties, etc. Here we present a 61 year old woman
with a history of chronic hepatopathy of cirrhotic type and imprecise etiology
(diagnosed since 1983). Approximately two years ago (1996-1997) she has been
presenting digestive hemorrhages and she has been transfused in different
occasions because she had severe anemia. Diffuse vascular ectasias in the distal
region of the antrum and in part of the gastric body were observed during
duodenoscopy and colonoscopy with signs of active hemorrhage and similar non
bleeding lesions in the colon. Pyruvic transaminase was normal; HBV and HCV
markers were -negative. Ultrasound analysis was normal. The diagnosis at the
discharge from Hospital was Diffuse Vascular Ectasias of the Gastric Antrum and
part of the gastric body, caecum and right colon, secondary to hepatic cirrhosis.
She was admitted again at the hospital because of new upper digestive hemorrhages
and surgery was indicated. Gastric resection was performed with promising
results. This case is analyzed and the pathology is results.
PMID- 10668070
TI - [Computed tomography-guided treatment of infected acute pancreatitis].
AB - We report a case of a 60 years old man admitted for infected acute pancreatitis
and duodenal fistula with mediastinal extension at admission, successfully
treated in a 40-days period with CT-guided percutaneous catheter drainage
(Malecot 14F) inserted with Seldinger method, in spite of a colic fistula
development during the treatment.
PMID- 10668071
TI - [Cancer of the esophagus and the stomach: should we become resigned or
investigate?].
PMID- 10668072
TI - Molecular biology diagnosis of hereditary non-polyposis colorectal cancer (HNPCC)
PMID- 10668073
TI - [Gastroesophageal reflux. To operate or to wait?].
PMID- 10668074
TI - [Suicides by police officials in North Rhine-Westphalia. An evaluation of 58
suicides between 1992 and 1998].
PMID- 10668075
TI - [Value of fingerprints for determining identity. Simultaneously a contribution on
significance for reconstruction of the behavior of a perpetrator based on the
evidence--trends over time].
PMID- 10668076
TI - [Death caused by neglect?].
AB - Over a period of several months a 23-year-old bedridden woman suffered from
increasing cachexia with numerous decubital ulcera in the parental house. The
parents induced the hospitalization not before the patient reached the agonal
phase. The reported case was especially spectacular because the left arm had
fallen off and lay beside the woman showing maggot infestation, mummification and
skeletonization. Against the parents a preliminary investigation for manslaughter
by negligence was instituted. This case report describes the unusual course of
disease and the striking familiar situation.
PMID- 10668077
TI - [Appearance of injuries caused by machetes and unusually large knives].
AB - Machetes (Spanish-American matchets) are sharp, long knives with a broad blade
having a slightly curved edge and a thick back. They are used for clearing paths
in rough, densely wooded areas. Just like axes and swords they are suitable for
causing not only soft tissue wounds, but also deep slashes in the underlying
bone. In military conflicts (especially in Central Africa) they are often used as
short-range weapons, whereas it is in the nature of things that they are rarely
used in Europe. On the basis of 5 cases from the Freiburg material fatal and
survived injuries caused by machetes and similarly large knives are discussed. In
2 cases long chop injuries were inflicted on the head causing sharp-edged
transections of the bony skullcap; in one case in which the victim survived a
broken off part of the blade lodged in the right os parietale. In another 2 cases
complete and subtotal decapitation respectively occurred in the victims. As the
instrument can be used both for cutting and stabbing there were not only long
cutting injuries, but also gaping stab wounds severing the skin over a length of
several centimetres; due to the great length of the blade through-and-through
wounds were also seen on the trunk. Massive blows with the thick back of the
blade caused streak-like bruising.
PMID- 10668078
TI - [Examples for use of the STR systems in stain assessment with special reference
to Y chromosome systems].
AB - The authors describe 3 cases where Y-chromosomal systems were used for typing the
biological traces. In the first case, a murder, for the major amount of cell
material found on a dish towel (and analysed two years after the crime) female
persons were excluded for the system amelogenin and Y-chromosomal systems. A
brother of the victim could not be excluded for autosomal STR-systems. Upon
confrontation with the results of the DNA-analysis (among other things), this
brother confessed the murder of his sister some days later. He was found guilty
by the court. In the second case described, a rape of two girls, many traces were
analysed parallely with Y-chromosomal and autosomal PCR-systems. The objects
where male DNA matching the suspect were found (a paper tissue, a sweat shirt and
the knickers of the girls), also showed small amounts of alleles matching with
the suspect for autosomal systems, while the major part in these systems was from
the girls. The suspect was sentenced to many years imprisonment. In the third
case, a possible rape of a young woman, a stained microscope slide of a vaginal
swab had to be examined. Microscopically a few sperm heads could be seen in a
surplus of leucocytes. The male proportion could be analysed only in the Y
chromosomal systems, not in the autosomal ones. For the frequency calculation of
the Y-chromosomal allele combination the haplotype data bank of the Institute for
Legal Medicine of the Humboldt university in Berlin was indispensable.
PMID- 10668079
TI - [Mitochondrial disfunction and perinatal exposure to antiretroviral nucleoside
analogues].
PMID- 10668080
TI - [Laryngeal foreign bodies: management in children in Senegal].
AB - Inhalation of foreign bodies is a frequent accident in children. It remains
severe in the case of laryngeal foreign bodies. PATIENTS AND METHODS:
Retrospectively, for a 16-year period, 65 laryngeal foreign bodies have been
treated (44.8%), among 145 cases of airway foreign bodies, in the ENT department
of Dakar University hospital. Etiological, clinical and therapeutic aspects were
reviewed. RESULTS: Average age was 36 months, with a sex-ratio of 2.42 in favour
of males. The time lag (time between the accident and admission to the
department) was particularly long; 73.33% of the children were admitted more than
24 hours after the event. Eighty-three percent of the patients presented greater
or lesser laryngeal dyspnea. Tracheostomy was performed in 55.4% of the patients.
Average duration for abiation of the canula was ten days. Three cases of death
were recorded (4.16%). DISCUSSION: The frequency of 44.8% for laryngeal
localization of foreign bodies appears to be the highest in the literature. If
the appropriate treatment for foreign bodies in the respiratory tract is
endoscopic removal, the tracheostomy nevertheless occupies a central place in the
management of the disease. This procedure may be recommended to all ENT
specialists working in similar conditions. In spite of its inherent
complications, tracheostomy allows reduction of mortality in relation to
laryngeal foreign bodies. Improvement of prognosis requires prevention based on
widespread public information and improving technical infrastructures.
PMID- 10668081
TI - [Sickle cell disease in children in Dakar, Senegal].
AB - AIM OF THE STUDY: To determine the socioeconomic, clinical and biological aspects
of sickle cell disease (SCD) in Senegalese children and adolescents, we
retrospectively analysed all records of follow-up attending patients in the
Albert Royer Children Hospital of Dakar (Senegal). RESULTS: Homozygous sickle
cell (SS) was the most frequent genotype (307 cases). Sickle cell hemoglobin C
(13 cases) and sickle cell beta-thalassemia (three cases) were uncommon. Patients
were aged from five months to 22 years (mean age: eight years). Most of them came
from poor families. The mean number of children was five in patients' families,
with at least two cases of SCD in 60% of them. Immunization against hepatitis B
virus (10.2%), Haemophilus influenzae b (8.4%), Salmonella (8.7%) and
Streptococcus pneumoniae (21.4%) was insufficiently performed, because of its
relatively high cost. Only 30% of the patients had received a blood transfusion.
Painful crises occurred less than three times a year in 74% of the cases.
Complications such as acute chest syndrome (1%), stroke (1%), cholelithiasis
(9%), meningitis (0.4%), septicemia (2%) and osteomyelitis (6%) were rare. Mean
steady state hemoglobin (Hb) and hemoglobin F(HbF) levels were 8.27 +/- 1.36 g/dL
and 6.8 +/- 5.9% respectively among SS patients. No correlations were found
neither between Hb and HbF nor between these parameters and the frequency of
complications. Eleven patients (1.1% per year of follow-up) died, and infection
was the main cause of death (73%). CONCLUSION: In comparison with published data,
SCD seems to have mild severity in Senegalese children and adolescents in spite
of poor follow-up conditions. In addition to genetic factors, environmental
factors might have an important role in disease tolerance.
PMID- 10668082
TI - [Adolescents and ambulatory care: results from a national survey of young people
15 to 20 years of age in Switzerland].
AB - In industrialized countries, statistics on health services exhibit a low level of
health care use by adolescents, despite the fact that their needs have been
widely described. OBJECTIVES: To assess ambulatory health care use by 15-20-year
old teenagers in Switzerland. METHOD: Nine thousand, two hundred and sixty-eight
adolescents responded to the self-administered questionnaire distributed in
secondary schools and vocational classes for the Swiss Adolescent Health Survey.
Questions about visits to general practitioners, specialists and gynecologists,
reasons for visit, the availability of a regular health care provider and a
confidential health care resource were analysed. RESULTS: Within the previous 12
months, 87.6% of the girls and 75.3% of the boys reported having seen a
physician. General practitioners were visited more frequently than specialists.
The contact with a specialist was the only one to be related to socio-demographic
variables: a lower proportion of reported visits to a specialist was related to
apprenticeship, low educational status of parents or rural living area. Thirty
nine percent of the girls reported having seen a gynecologist during the previous
12 months. Two adolescents out of three reported having a personal doctor, and
one out of two declared being aware of a confidential health care resource. Girls
reported a larger number of reasons for visits than boys: chronic conditions,
fatigue, headache and depressive symptoms were the most often cited in a list of
ten reasons. Among the subjects who declared a health concern (sleep
disturbances, eating disorders, depressive symptoms, smoking or alcohol-related
problems) and a need for help, less than 10% declared having seen a health care
provider for this reason, even if more than 70% reported contact with a physician
within the last 12 months. CONCLUSION: These results show that most adolescents,
especially girls, reported recent use of medical services, but did not discuss
their health concerns with the doctor. Training should be improved to give better
knowledge and counseling skills to health professionals, in order to allow them
to address adolescents' health needs.
PMID- 10668083
TI - [Preoperative mortality in transposition of the great vessels].
AB - The aim of the study was to report the incidence and causes of preoperative
deaths in isolated transposition of the great vessels and to describe the
clinical findings in these neonates. PATIENTS AND METHODS: In five French centers
of pediatric cardiology, data of all the neonates with isolated transposition of
the great vessels who died before arterial switch operations between January 1986
and June 1996 were obtained from reviewing hospital files, echocardiography
records and autopsy reports. RESULTS: Among 199 neonates with transposition of
the great vessels, 20 (9.9%) died before surgery. The death was related to
intracranial haemorrhage in one premature neonate, severe and early hypoxemia in
13 full-term patients (group A) and later sudden collapse in six patients (group
B). In group A, the symptoms occurred within 20 minutes after the birth and
included cyanosis (n = 12), acute respiratory distress (n = 8), and shock (n =
4). Despite assisted ventilation (n = 13), bicarbonate infusion (n = 12),
prostaglandin E1 (n = 7), inotropic drugs (n = 5) and balloon atrioseptostomy (n
= 7), death occurred at the median age of five hours. The patent foramen ovale
was absent or tiny in ten patients, normal in one patient and not specified in
two patients. The ductus arteriosus was patent in ten patients and not specified
in three patients. In group B, the neonates were initially in a good hemodynamic
condition. Unexplained death occurred between two and five days after the birth:
one infant with a large patent foramen ovale did not receive prostaglandin E1,
four patients died a few hours after an angiographic study or a balloon
atrioseptostomy was performed in a catheterization laboratory, and one child
suffered from a cerebral anoxia due to a tightened cord. CONCLUSION: We conclude
that the high preoperative mortality rate in isolated transposition of the great
vessels is mainly due to absent or small atrial shunt. These findings suggest
that only prenatal diagnosis of transposition of the great vessels with immediate
balloon atrioseptostomy could avoid a fatal outcome.
PMID- 10668084
TI - [Neonatal hemochromatosis].
AB - Neonatal hemochromatosis is characterized by abnormal hepatic and extrahepatic
iron overload, which spares the reticuloendothelial system. In neonates,
hemochromatosis results in an acute and frequently lethal liver failure. CASE
REPORTS: We report five cases of neonatal hemochromatosis which demonstrate
various aspects of this disorder and underline the complexity of both the
diagnosis and treatment. Case 3 had an extremely low arterial pressure, a
presentation not yet described. CONCLUSION: Neonatal hemochromatosis should be
suspected in the presence of cholestasis with liver failure of perinatal onset
and with high blood level ferritin. Abdominal nuclear magnetic resonance and/or
liver biopsy can confirm neonatal hemochromatosis. For one of our patients, a
medical treatment allowed us to perform a liver transplantation.
PMID- 10668085
TI - [Neonatal hyperparathyroidism secondary to unknown maternal hypoparathyroidism].
AB - Vitamin D or its analogue (calcitriol) is an effective treatment for
hypoparathyroidism during pregnancy. Normal babies are delivered and very few
cases of associated neonatal hyperparathyroidism are reported. CASE REPORT: We
report the case of a baby born to a mother suffering unknown hypoparathyroidism.
He was delivered prematurely by cesarean section for birth asphyxia. His mother
had had recurrent bouts of impetigo herpetiformis for several months. Severe
demineralization associated with decreased plasma calcium level were observed at
birth. The PTH level was very high (955 ng/mL) in the baby and very low in the
mother, leading to the diagnosis. The baby was given intravenous calcium
gluconate, oral 1 alpha-hydroxyvitamin D and mechanical ventilation. Normal
plasma calcium level was reached on day 2. PTH level improved by one month of
age. Because of impaired respiratory mechanics and bronchopulmonary dysplasia,
the baby was kept on ventilation for 58 days. By 20 months of age, he was in good
health despite a small height for his age. CONCLUSION: In such cases 1 alpha
hydroxyvitamin D seems to be very effective but plasma and urinary calcium levels
need careful monitoring.
PMID- 10668086
TI - [Preoperative evaluation of choledochal cyst with MR cholangiopancreatography].
AB - The choledochal cyst is a rare congenital disorder usually diagnosed in
childhood. It requires a complete surgical resection to prevent complications,
particularly the risk of malignant changes. At present, the preoperative
examination requires a direct opacification of the biliary tree, but this is an
invasive technique with a high risk of infection, especially in pediatric
patients. CASE REPORT: A choledochal cyst was diagnosed in a five-year-old girl
with recurrent abdominal pain. Diagnosis was made by ultrasound and preoperative
evaluation by magnetic resonance-cholangiopancreatography using single-shot fast
spin echo sequences. A complete correlation was observed between surgical,
preoperative cholangiography and MRCP data. CONCLUSION: Recent improvement in
MRCP techniques provide a complete anatomic analysis of choledochal cysts,
enabling one to diagnose an anomalous junction of the pancreaticobiliary duct,
even the presence of stones within the biliary tree. This short and noninvasive
examination should in the future replace direct opacification of the biliary tree
for the preoperative assessment of choledochal cysts.
PMID- 10668087
TI - [(P)FAPA syndrome: value of cimetidine].
AB - The (P)FAPA syndrome (periodic fever, adenitidis, pharyngitis, aphthous
stomatitis) was described in 1987. The etiology of this periodic syndrome remains
unknown. We report three new cases. CASE REPORTS: Three girls, aged from 23
months to eight years, developed (P)FAPA. The other causes of periodic fevers
were eliminated and the various treatments (antibiotics, antipyretics,
nonsteroidal anti-inflammatory agents) proved ineffective. The repetition of the
periodic bouts resulted in depressive disorders, absenteeism from school and a
drop in weight in the youngest patient. Two of them suffered a sinusal
involvement (chronic sinusitis, polyp) and had an increase in the level of
immunoglobulin A. In all three cases, cimetidine at a dose of 20 mg/kg/d was well
tolerated and resulted in a disappearance of the periodic fevers. CONCLUSION:
Cimetidine, as an immunomodulating agent, appears to be beneficial in the in
depth treatment of (P)FAPA syndrome.
PMID- 10668088
TI - [Palliative care in pediatric oncology].
AB - Improving the management of dying children has always been a common desire among
staff who take care of children with incurable life-threatening diseases.
Pediatric oncologists are beginning to structure their practice based upon the
approach to palliative care given to adults. In the first part of this report,
the authors focus on technical care: comfort control and symptoms. The second
part is devoted to pain management, a major aspect of pediatric palliative care.
In the third part, psychosocial issues are developed, taking into account the
point of view of children, siblings, parents and staff.
PMID- 10668089
TI - [Iodine nutrition in the infant. Committee on Nutrition of the French Society of
Pediatrics].
AB - Iodine is a trace element essential for the synthesis of thyroid hormones. It is
present in the human body in minute amounts (15-20 mg in adults). The thyroid is
very sensitive to iodine deficiency in newborns and infants because of its very
low iodine content. Daily iodine requirements in humans vary from 40 micrograms
in neonates to 150 micrograms in adults. Iodine deficiency represents the first
cause of avoidable mental deficiency in developed countries; it has not yet
disappeared in Europe, especially in the East, where it is responsible for a high
prevalence of goiter. Iodine deficiency during pregnancy increases the risk of
neonatal transient hypothyroidism, with a high recall rate in programs of
systematic screening for congenital hypothyroidism. Data available in France
suggest that screening for iodine deficiency should be performed during
pregnancy, and that the minimal iodine concentration in formula milk should be
increased to 10 micrograms/100 kcal for term infants and 20 micrograms/100 kcal
for premature infants. Iodine deficiency is ideally prevented by the use of
iodized salt. Because of the risk of iodine overexposure and secondary transient
hypothyroidism, the use of iodinated antiseptics must be avoided in premature
babies and neonates as well as in pregnant and lactating women. The fight against
iodine deficiency, associated with oral stable preventive iodine administration,
decreases sharply the risk of thyroid cancer in case of nuclear exposure, by
diminishing thyroid uptake of iodine radioactive isotopes.
PMID- 10668090
TI - [Radiology case of the month. Extrapontine myelinolysis].
PMID- 10668091
TI - [What is the role of tonsillectomy in children?].
AB - Tonsillectomy is mandatory in the case of chronic airway obstruction associated
with tonsillar hypertrophy and in the case of a unilateral enlarged tonsil which
may be malignant. Tonsillectomy may be indicated in recurrent tonsillitis. More
rarely, tonsillectomy is performed in children for tonsil bleeding or chronic
tonsillitis. Allergy and bleeding disorders are not a contraindication for
tonsillectomy.
PMID- 10668092
TI - [Accidental HIV exposure of children through injury with discarded syringes].
AB - Potential HIV exposure through injury with discarded syringes is a frequent event
among children. Although no case of HIV infection has been reported so far in
this context, an antiretroviral prophylaxis is generally proposed. Such treatment
is extrapolated from consensus for management of exposed health care workers.
Extremely low-risk and difficult administration of available drugs allows a case
by-case analysis and generally a less aggressive treatment.
PMID- 10668093
TI - [Photosensitive epilepsy and television epilepsy].
AB - Photosensitivity is defined by the appearance of occipital or more diffuse
electroencephalographic spikes and waves induced by intermittent light
stimulation (ILS), particular patterns, TV-watching, and video games.
Photosensitivity is a genetic characteristic. Only the diffuse spikes and waves
induced by ILS are correlated with epilepsy. Pure photogenic epilepsy is
characterized by seizures which are only visually induced, usually by watching
TV. Video games sometimes add a trigger effect due to slowly moving patterns or
intense brightness. Several epileptic syndromes are associated with a
photosensitivity with or without visually-induced seizures, mainly generalized
idiopathic epilepsy.
PMID- 10668094
TI - [Spontaneous neonatal gastric perforation].
PMID- 10668095
TI - Transient reactivation of CSF in parthenogenetic one-cell mouse embryos.
AB - During meiosis, the cytostatic factor (CSF) activity stabilizes the activity of
the M-phase promoting factor (MPF) in metaphase II arrested vertebrate oocytes.
Upon oocyte activation, the inactivation of both MPF and CSF enables the entry
into the first embryonic mitotic cell cycle. Using a biological assay based on
cell-fusion (hybrid between a parthenogenetically activated egg entering the
first mitotic division and an activated oocyte), we observed that in activated
mouse oocytes a first drop in CSF activity is detectable as early as 20 min post
activation. This suggests that CSF is inactivated upon MPF inactivation. However,
CSF activity increases again to reach a maximum 60 min post-activation and
gradually disappears during the following 40 min. Thus, in activated mouse
oocytes (undergoing the transition to interphase) CSF activity fluctuates before
definitive inactivation. We found that hybrids arrested in M-phase, thus
containing CSF activity after oocyte activation, have activated forms of MAP
kinases while hybrids in interphase have inactive forms of these enzymes. We
postulate that CSF inactivation in mouse oocytes proceeds in two steps. The
initial inactivation of CSF, required for MPF inactivation, is transient and does
not require MAP kinase inactivation. The final inactivation of CSF, required for
normal embryonic cell cycle progression, is dependent upon the inactivation of
MAP kinases.
PMID- 10668096
TI - The Saccharomyces cerevisiae Cdc14 phosphatase is implicated in the structural
organization of the nucleolus.
AB - Cdc14, a dual-specificity protein phosphatase, has been previously implicated in
triggering exit from mitosis in the yeast Saccharomyces cerevisiae. Using
immunofluorescence microscopy and immunogold labeling, we demonstrate that a
functional HA-tagged version of the phosphatase Cdc14 localizes to the nucleolus.
Moreover, Cdc14-HA co-localized with the nucleolar NOP2 and GAR1 proteins. By
immunofluorescence, Cdc14-HA was found in the nucleolus during most of the
mitotic cell cycle, except during anaphase-telophase when it redistributed along
the mitotic spindle. While this work was in progress, the same pattern of Cdc14
localization was described by others (Visintin et al, Nature 398 (1999) 818).
Constitutive overexpression of CDC14 was toxic and led to cell cycle arrest of
cells, mainly in G1. This correlated with the appearance of abnormal nuclear
structures. A genetic search for suppressors of the lethality associated with
CDC14 overexpression identified YJL076W. Because overproduction of Yj1076w
buffered the toxic effect of Cdc14 overproduction, this suggested that it might
be a substrate of Cdc14. This has indeed been found to be the case by others who
recently described Yj1076w/Netl as a nucleolar protein that physically associates
with Cdc14 (Shou et al, Cell 97 (1999) 233). The present data confirm several
recently uncovered aspects of the regulation of Cdc14 localization and activity
and suggest that the level of expression of CDC14 influences the structural
organization of the nucleolus.
PMID- 10668097
TI - p53-independent regulation of cyclin B1 in normal human fibroblasts during UV
induced G2-arrest.
AB - Recently we demonstrated, using normal human fibroblasts (NHFs), that UVc
radiation induces a G2/M arrest which was even more pronounced when p53
expression was inhibited. So, the aim of this study was to evaluate in NHFs the
relationship between UV-induced G2/M arrest and cyclin B1 regulation and to
investigate if p53 could contribute to the cyclin B1 regulation in these
conditions. Following exposure of asynchronous NHFs to UV light, we showed that
the induced G2/M arrest was accompanied by a dose-dependent down-regulation of
cyclin B1 mRNA as evaluated by RT-PCR. Concomitantly, using flow cytometric
analysis, we observed a strong accumulation of cyclin B1 protein which was
correlated to the apparition of the G2/M arrest. In order to study the
contribution of p53 to the cyclin B1 accumulation in response to UV exposure, we
inhibited p53 induction using p53 antisense oligonucleotides. We found that the
inhibition of p53 protein induction after UV exposure had no effect on the level
of cyclin B1 mRNA. Moreover, although inhibition of p53 protein induction
increased the number of the cells in the G2-M phase, the mean content of cyclin
B1 protein was not augmented in these cells. These results indicate clearly that
the induction of p53 protein following UV exposure does not regulate the level of
cyclin B1 mRNA or protein in normal cells.
PMID- 10668098
TI - Dynamics of glial fibrillary acidic protein distribution in cultured glomerular
podocytes and mesangial cells of the rat kidney.
AB - Glial fibrillary acidic protein (GFAP) has recently been shown to be expressed in
the glomerular podocytes and mesangial cells (MC) of kidney (Buniatian et al
(1998) Biol Cell 90, 53-61). The different localization of GFAP in podocytes and
MC has raised the question whether this might reflect specific cellular
functions. To address this question, in the present study podocytes and MC in
early (2, 3 day-old), prolonged (5, 7 day-old) and late (14, 21 day-old) primary
cultures from out-growths of glomerular explants were used. Double-immunolabeling
studies demonstrated that podocytes transiently acquire myofibroblastic features,
characterized by the expression of smooth muscle alpha-actin (SMAA) and increased
perinuclear reaction of GFAP in prolonged cultures. The morphological
differentiation of cobblestone-like podocytes into process-bearing cells was
followed by loss of the myofibroblastic marker, SMAA, de novo expression of
desmin, and distribution of GFAP, vimentin and desmin into the processes. In late
culture, GFAP and SMAA were nearly absent from the podocytes which maintained the
cobblestone-like morphology. By contrast, the myofibroblastic features gained by
MC during prolonged culturing increased with time. A myofibroblast-like
cytoskeleton of podocytes and MC similar to that of healthy astrocytes suggest an
increased spectrum of functional activities of these cells during the acquisition
of myofibroblastic features. In addition, the present study provides a new
combination of biochemical and biological features by which podocytes and MC can
be distinguished in culture.
PMID- 10668099
TI - Composition and organization of tubulin isoforms reveals a variety of axonemal
models.
AB - In the flagellum of mammalian spermatozoa, glutamylated and glycylated tubulin
isoforms are detected according to longitudinal gradients and preferentially in
axonemal doublets 1-5-6 and 3-8, respectively. This suggested a role for these
tubulin isoforms in the regulation of flagellar beating. In the present work,
using antibodies directed against various tubulin isoforms and quantitative
immunogold analysis, we aimed at investigating whether the particular
accessibility of tubulin isoforms in the mammalian sperm flagellum is restricted
to this model of axoneme surrounded with periaxonemal structures or is also
displayed in naked axonemes. In rodent lung ciliated cells, all studied tubulin
isoforms are uniformly distributed in all axonemal microtubules with a unique
deficiency of glutamylated tubulin in the transitional region. A similar
distribution of tubulin isoforms is observed in cilia of Paramecium, except for a
decreasing gradient of glutamylated tubulin labeling in the proximal part of
axonemal microtubules. In the sea urchin sperm flagellum, predominant labeling of
tyrosinated and detyrosinated tubulin in 1-5-6 and 3-8 doublets, respectively,
were observed together with decreasing proximo-distal gradients of glutamylated
and polyglycylated tubulin labeling and an increasing gradient of monoglycylated
tubulin labeling. In flagella of Chlamydomonas, the glutamylated and glycylated
tubulin isoforms are detected at low levels. Our results show a specific
composition and organization of tubulin isoforms in different models of cilia and
flagella, suggesting various models of functional organization and beating
regulation of the axoneme.
PMID- 10668100
TI - Rat arylalkylamine N-acetyltransferase gene: upstream and intronic components of
a bipartite promoter.
AB - The daily rhythm in the activity of arylalkylamine N-acetyltransferase (AA-NAT)
controls the rhythm in melatonin synthesis in the pineal gland. In the rat,
transcriptional regulatory mechanisms play a major role in determining the
observed pattern of AA-NAT gene expression. Remarkably, high levels of AA-NAT
transcripts can only be detected in the night pineal; significant levels can also
be found in the retina. To characterize the regulatory events that impinge upon
the activity of the AA-NAT gene we embarked on the systematic analysis of the AA
NAT promoter. To this end we transfected several AA-NAT promoter derivative
constructs to monitor reporter gene activity in both pineal and non-pineal
primary cell cultures. Our studies revealed a cooperative arrangement between
upstream promoter and downstream intronic regions which appear to contain most of
the key elements necessary to ensure the proper spatio-temporal pattern of AA-NAT
gene expression.
PMID- 10668101
TI - Methodological aspects of auditory evoked potentials.
PMID- 10668102
TI - Transformed migraine: a proposal for the modification of its diagnostic criteria
based on recent epidemiological data.
PMID- 10668103
TI - Possible antimigraine mechanisms of action of the 5HT1F receptor agonist
LY334370.
AB - This study investigated whether the selective 5HT1F receptor agonist LY334370 has
other possible antimigraine mechanisms in addition to the proposed inhibition of
dural plasma extravasation. LY334370 (up to 10(-5) M) had no vasoconstrictor
effects on human cerebral arteries in vitro. It had no effect (up to 10 mg kg-1,
i.v.) on neurogenic vasodilation of dural blood vessels produced by electrical
stimulation of the dura mater in anesthetized rats. Nor had it any effect (at 3
mg kg-1, i.v.) on the hyperalgesia produced by injection of carrageenan into the
paw of conscious rats or on nociceptive reflex responses in the spinalized,
decerebrate rabbit (up to 3 mg kg-1, i.v.), indicating that it has no general
analgesic properties. However, it significantly inhibited activation of second
order neurons in the trigeminal nucleus caudalis produced by electrical
stimulation of the dura mater in anesthetised rats at 3 mg kg-1, i.v. These
results provide evidence to suggest that LY334370 has a central mechanism of
action in blocking the transmission of nociceptive impulses within the trigeminal
nucleus caudalis and that this may represent a mechanism through which it has its
antimigraine effect.
PMID- 10668104
TI - Serotonin 5HT1B/1D receptor agonists abolish NMDA receptor-evoked enhancement of
nitric oxide synthase activity and cGMP concentration in brain cortex slices.
AB - Our previous studies indicating that the function of excitatory amino acids, NMDA
type receptor, is modulated by serotonin focused on the interaction between
serotonin 5HT1B/1D and glutamate, NMDA receptor in brain cortex. The effect of
agonists of 5HT1B/1D receptor, sumatriptan, and zolmitriptan on NMDA receptor
evoked activation of nitric oxide (NO) and cGMP synthesis in adult rat brain
cortex slices was investigated. Two kinds of experiment were carried out using
adult rats. In one of them, sumatriptan or zolmitriptan was administered in vivo
subcutaneously (s.c.) in a dose of 0.1 mg per kg body weight. Brain slices were
then prepared and used in the experiments or, in the other exclusively in vitro
studies, both agonists at 10 microM concentration were added directly to the
incubation medium containing adult rat brain cortex slices. The data obtained
from these studies indicated that stimulation of NMDA receptor in brain cortex
slices leads to a large increase in calcium, calmodulin-dependent NO synthase
(NOS) activity and to significant enhancement of the cGMP level. This NMDA
receptor-dependent NO and cGMP release was completely blocked by competitive and
noncompetitive NMDA receptor antagonists APV (10 microM) or MK-801 (10 microM.),
respectively. The specific inhibitor of Ca(2+)-dependent isoforms of NOS (N-nitro
1-arginine NNLA and 7-nitroindozole (7-N1)) eliminated the NMDA receptor-mediated
enhancement of NO and cGMP release. Moreover, the serotonin 5HT1B/1D receptor
agonists sumatriptan and zolmitriptan administrated in vivo (s.c.) or in vitro
abolished NMDA receptor-evoked NO signalling in brain cortex. The potency of both
agonists investigated directly in vitro was similar to their effect after in vivo
administration. These results suggest that both serotonin 5HT1B/1D receptor
agonists may play an important role in modulating the NO and cGMP-dependent
signal transduction pathway in the brain. This effect of sumatriptan and
zolmitriptan on NO signaling in the brain system should be taken into
consideration when investigating their mechanism of action in the migraine
attack.
PMID- 10668105
TI - Genetic and environmental influences on recurrent headaches in eight to nine-year
old twins.
AB - The major objective of the present study was to estimate genetic and
environmental influences on recurrent headaches in prepubescent twins. A
nationwide cohort of 8 to 9-year-old Swedish twins (n = 1,480) was screened for
nonsymptomatic and recurrent headaches through a questionnaire mailed to their
parents (75% response frequency). Among positives, 79% of headaches were
classified as migraine or tension-type headache in close accordance with the
International Headache Society criteria. The prevalences of migraine and
nonmigrainous headaches were 2.4% and 11.3%, respectively, and without
significant differences between the sexes or zygosity types. Inheritance on
liability to recurrent headaches was estimated to 70% (a2 = 0.70, 95% CI = 0.54
0.82) for boys and girls but the genetic effect was found to be uncorrelated
between the sexes. We conclude that genetic and individual specific effects are
important for recurrent headaches of migrainous and nonmigrainous types in
prepubescent children, and that different genetic etiologies might exist for boys
and girls.
PMID- 10668106
TI - Repeatability of the intensity dependence of cortical auditory evoked potentials
in the assessment of cortical information processing.
AB - Data on repeatability and optimal settings are needed when studying the influence
of drugs on the intensity dependence of auditory evoked cortical potentials
(IDAP). IDAP was recorded at intervals of 1, 2, and 24 h at two centers in 22
healthy volunteers. Settings were modified to compare fixed versus randomly
varied stimulus repetition rate, as well as 30 Hz and 100 Hz low pass filters.
Repeatability was assessed for different intervals and different settings. Group
means did not differ between centers, the 2-h or 24-h retest, or when using
different settings. We observed an order effect for the 1 h retest. Fixed
repetition rate and the 30 Hz filter improved repeatability with still high
intraindividual variability. IDAP group means can be compared between centers for
retest intervals of 2 h and 24 h and different settings. Variability is too large
to compare individuals.
PMID- 10668107
TI - Auditory evoked potentials in the assessment of central nervous system effects of
antimigraine drugs.
AB - Because the "intensity dependence" of cortical auditory evoked potentials (IDAP)
is under serotonergic control, it can be used to assess central antimigraine
effects of 5HT1B/1D agonists. We measured IDAP before and 2 h after naratriptan
(5 mg, n = 19) and zolmitriptan (5 mg, n = 19) in healthy volunteers. IDAP was
expressed as the amplitude-stimulus intensity function ("ASF slope"). Naratriptan
tended to increase ASF slope (mean difference 0.23 +/- 0.62 microV/10 dB, p =
0.06) while zolmitriptan (0.08 +/- 0.95 microV/10 dB, p = 0.35) did not. We
assessed the suitability of IDAP for measuring central antimigraine drug effects
using repeatability data (see companion paper). We calculated the trade-off
between the size of the expected drug effects (ASF slope difference) and the
necessary sample size. Because of poor repeatability 36 to 80 subjects are
required to detect ASF slope changes in the 0.25-0.5 microV/10 dB range. These
data can be used to design trials using IDAP.
PMID- 10668108
TI - Out-of-body experiences and related phenomena in migraine art.
AB - In a collection of 562 migraine art pictures, seven pieces illustrate various
elements of out-of-body experiences (OBEs) and related phenomena, including the
somesthetic sensations of a duplicate or parasomatic body and the visual
experiences of perceiving the own body, i.e. autoscopy, and its environment from
a vantage point out of the body. Phenomenological features of the OBEs depicted
are compared with 17 similar case reports reviewed from the literature. It is
concluded that OBEs can occur as migraine aura symptom, which supports the notion
that OBEs represent a preformed functional response of the brain. This
neuropsychological theory supplements existing psychological theories of OBEs,
which consider the said phenomena as representing hallucinatory experiences based
on imagination and memory.
PMID- 10668109
TI - Cervicogenic headache: long-term postoperative follow-up.
AB - The patient, a 50-year old female had been suffering from right-sided head- and
neck pain since she was 31 years of age. It started in connection with an
indirect neck trauma. Analgesics were of little or no avail and operative
procedures, including liberation of the greater occipital nerve (GON) (n = 2) and
decompression of the C2 ganglion/root, had only a transitory effect. At 42, a
magnetic resonance scan of the cervical spine demonstrated a degenerated disk C5
C6, with encroachment on the foramina and the cord. At 42 years of age, a
stabilization operation at C5-C6 (Robinson-Smith) alleviated her discomfort--only
some motor complaints in the ipsilateral upper extremity remaining and only in
the first 12-18 months.
PMID- 10668111
TI - The tension-type headache alternative. Peripheral pathophysiological mechanisms.
PMID- 10668110
TI - Muscle activity as a releasing factor for pain in the shoulder and neck.
AB - In this review, the evidence for trapezius muscle activity as a releasing factor
for shoulder and neck pain is considered, mainly on the basis of studies in our
laboratory. Two lines of evidence are produced, (i) vocational studies in an
occupational setting, where muscle activity pattern is recorded by surface EMG
and a clinical examination of the shoulder region of the subjects performed; and
(ii) laboratory studies where muscle activity patterns and pain development are
recorded in an experimental situation with mental stress and minimal physical
activity. The vocational studies demonstrate pain development in the shoulder and
neck despite very low muscle activity recorded, making it very difficult to
assume muscular involvement for all cases with such complaints. However, the
hypothesis of pain development through overexertion of a subpopulation of low
threshold motor units also makes it difficult to draw a firm negative conclusion.
The laboratory experiments, on the other hand, show that trapezius activity
patterns in response to stress have many features that would be expected if
muscle activation induces pain symptoms. It is further noted that the trapezius
is the only muscle with activity patterns that show these features. Possibly, we
observe the effects of parallel physiological phenomena, e.g., a systemic
autonomic activation that induces pain symptoms and also facilitates the motor
response of some muscles. Evidence of autonomic activation of trapezius is
presented by the observation of low-level, rhythmic EMG activity during sleep.
However, this is not firm evidence for the above hypothesis, which at present
best serves as a basis for further experimentation.
PMID- 10668112
TI - Cervicogenic headache: a comparison with migraine and tension-type headache.
AB - Cervicogenic headache (CEH) is a neck-generated headache syndrome. Attacks may be
similar to migraine (M) or tension-type headache (TTH). In order to test the
accuracy of the IHS diagnostic criteria for M and episodic TTH and of the
criteria for CEH of Sjaastad et al., 33 CEH, 65 M, and 29 TTH were evaluated
according to the CEH criteria, and CEH patients were tested for M and TTH
according to the IHS criteria. Only 30% of the CEH patients met the criteria for
M, 3% met the criteria for TTH, and 66% were neither M nor TTH. The mean number
of criteria met, sex, age, and age of onset were also analysed, and the results
indicate an inequality among these three headache types. The most important
differentiating aspects were the site and radiation of the pain, the temporal
pattern, and the induction of attacks from neck posture, movements, and/or
digital pressure. CEH clearly differs from M and TTH. Existing criteria
adequately distinguish the three headaches.
PMID- 10668113
TI - Migraine and hypertension.
AB - Association between mild to moderate hypertension and headache is probably
coincidental. Severe sustained hypertension, malignant hypertension and
paroxysmal hypertension (sudden rise) are associated with severe headache.
Transient hypertension can occur during an attack of migraine or cluster
headache. Hypertension may increase the frequency and severity of migraine in
migraineurs and may transform an episodic migraine into chronic daily headache.
Concomitant treatment of hypertension is important in these patients.
PMID- 10668114
TI - Epidemiology and socio-economic impact of headache.
AB - Headache disorders constitute a public-health problem of enormous proportions,
with an impact on both the individual sufferer and society. Epidemiological
knowledge is required to quantitate the significance of these disorders. The
effects on individuals can be assessed by examining prevalence, distribution,
attack frequency and duration, and headache-related disability. The socio
economic burden includes both direct costs associated with healthcare utilization
and costs associated with missed work due to sickness absence or reduced
efficiency. The individual and socio-economic burden of headaches is substantial.
Headache disorders deserve more attention, especially concerning strategies
leading to adequate primary prevention, diagnosis, and treatment.
PMID- 10668115
TI - The Vaga Study: an outline of the design.
AB - We carried out an epidemiological study of headache in a rural parish in the
mountainous region of southern Norway. During a 2-year period from October 1995,
1838 parishioners in the age range 18-65 (or 88.6% of the target group) were
examined in a structured interview based on a questionnaire. The questionnaires
were validated in two ways: 100 records were re-checked, with a consistency of
98%, and a re-check of 41 parishioners was carried out > 2 months after the 1st
examination. The details of the latter control study will be reported later. Only
one result of the study is given: namely, idiopathic stabbing headache ("jabs and
jolts syndrome") was present in > 30% of parishioners.
PMID- 10668116
TI - Periorbital pain: a clinical review.
PMID- 10668117
TI - Recurrent Tolosa-Hunt syndrome: a report of ten new cases.
AB - Ten patients (6F, 4M) with recurrent Tolosa-Hunt syndrome are reported. Besides
ocular motor symptoms, one patient had trigeminal nerve involvement, one had
ipsilateral ocular sympathicoplegia with miosis and ptosis, and one tinnitus
during an episode of Tolosa-Hunt syndrome, ipsilateral to the pain side. One
patient had Bell's palsy, one had a possible Raeder's syndrome, and one had a
period of tinnitus between the Tolosa-Hunt syndrome episodes. Three of the 10
patients reported periods of periocular pain without ophthalmoplegia between the
Tolosa-Hunt episodes, the pain located ipsilateral to the ophthalmoplegic side in
the Tolosa-Hunt episodes. Systemic symptoms associated with Tolosa-Hunt syndrome,
e.g., back pain, chronic fatigue, arthralgia, gut problems among others, occurred
with the same frequency in these 10 patients as in an earlier report. Seventy per
cent of the patients had signs of inflammation in serum during a period of Tolosa
Hunt syndrome. Orbital phlebograms showed pathologic signs in four of the five
patients investigated during a Tolosa-Hunt period. One phlebogram was normal in a
sixth patient when performed during a period of unilateral periocular pain
without ophthalmolegia. Magnetic resonance imaging of the head (with contrast)
was only performed in three patients during the Tolosa-Hunt period: one showed
signs of inflammation in the middle fossa and two were normal. In one of the
patients with normal magnetic resonance imaging, the orbital phlebogram was
pathologic. Steroid treatment promptly relieved the pain in all patients.
PMID- 10668118
TI - Tolosa-Hunt syndrome: focus on MRI diagnosis.
AB - Experience with modern neuroimaging techniques, computed tomography (CT) and
magnetic resonance imaging (MRI) scans, in the diagnosis of Tolosa-Hunt syndrome
(THS) is reviewed. Conventional CT scan remains normal in about two-thirds of
these patients. In the reported 22 patients meeting the IHS criteria for a THS
diagnosis on whom an MRI study was performed, MRI revealed a convex enlargement
of the symptomatic cavernous sinus by an abnormal tissue isointense with gray
matter on short TR/TE images and isohypointense on long TR/TE images. This
abnormal tissue markedly increases in signal intensity after contrast injection.
MRI seems also to be the ideal technique to follow progressive resolution of the
abnormal tissue after steroids. Therefore, normal MRI would probably exclude THS,
whereas in the appropriate clinical setting of steroid-responsive painful
ophthalmoplegia, MRI showing the cavernous sinus abnormality described here
suggests a diagnosis of THS. From these data, we propose that the fourth IHS
criterion for THS diagnosis, "Exclusion of other causative lesions by
neuroimaging and (not compulsory) carotid angiogram" should be changed to
"Finding by MRI of specific cavernous sinus abnormalities (with the
characteristics described herein) which slowly resolve with steroid treatment".
PMID- 10668119
TI - Cluster headache: new perspectives.
PMID- 10668120
TI - Raeder's syndrome.
AB - Raeder's syndrome was first described by the Norwegian ophthalmologist J. G.
Raeder in 1918, and the description extended in 1924 by the same author. The
seminal report was a description of a young, male patient with unilateral
periocular pain combined with ipsilateral miosis and ptosis, and with slight
objective signs of trigeminal nerve involvement. Autopsy demonstrated a tumor at
the base of the skull in the middle cranial fossa. The term "paratrigeminal" was
coined for the picture reported. Later case reports by the same and other authors
have included patients with a more benign clinical course, including spontaneous
remissions, with unilateral periocular pain and ipsilateral signs of
oculosympathetic paresis as the common denominator. This review is a
chronological survey of the main contributions that have appeared in the
literature and an outline of the various definitions of the syndrome, including a
recent classification as well as some pathophysiological and prognostic
considerations.
PMID- 10668121
TI - SUNCT syndrome versus idiopathic stabbing headache (jabs and jolts syndrome).
AB - Both SUNCT syndrome and idiopathic stabbing headache (ISH) (jabs and jolts
syndrome) have to be considered when encountering shortlasting headaches. Since
there are no specific tests for these headaches, the differential diagnosis
depends entirely upon assessment of the clinical features. These headaches are
generally easily distinguishable clinically. There seem to be symptomatic forms
of SUNCT.
PMID- 10668122
TI - Familial occurrence of headache.
AB - Associations between the occurrences of headache among parents and their
offspring during a 7-year follow-up were studied. Data were collected using a
prestructured questionnaire from a representative population-based sample of 1443
families expecting their first child. Seven years later, another questionnaire
was sent to 1132 families still included in the study. Questionnaires were
returned by 968 families. One or either of the parents had experienced frequent
headache in 47% of families (34% of the mothers and 19% of the fathers) before
pregnancy. Of the 6-year-old children, 15% had headache disturbing daily
activities. Mother's prepregnancy headache was a clear predictor of her child's
preschool headache (p = 0.006, OR = 1.7, 95% CI 1.2-2.4). In the clinical
interview, the children with headache more often had first-degree and second
degree relatives with headache than the control children.
PMID- 10668123
TI - Migraine and nonmigrainous headache--how to distinguish them.
PMID- 10668124
TI - Tension-type headache in children.
PMID- 10668125
TI - Sleep hygiene and migraine in children and adolescents.
AB - Although sleep problems are a common complaint in migraine patients, the role of
sleep habits and hygiene as triggering factors of head pain attacks has been
poorly analyzed. The aim of this study was to evaluate the effect of modifying
bad sleep habits across several headache parameters. Based on our previous study,
we selected 70/164 migraineurs (42.7%) with poor sleep hygiene and randomly
assigned them to two groups: group A migraineurs, who were instructed to follow
directions to improve sleep hygiene; and group B migraineurs who were not given
instructions on improving sleep hygiene. Mean duration and frequency of migraine
attacks were significantly reduced at follow-up in group A, while group B showed
only an insignificant initial reduction. No differences were found in the
severity of migraine attacks that seemed related to a higher prevalence of
nocturnal symptoms such as bedtime struggles, hypnic jerks, nightmares, and
restless sleep. Our study is an alternative approach to the treatment of
migraine, i.e. treatment through a simple modification of sleep behavior without
recurring to pharmacological treatment.
PMID- 10668126
TI - Slow cortical potentials in migraine: a comparison of adults and children.
AB - Amplitudes of contingent negative variation (CNV) in 40 migraine patients were
studied during the pain-free period and compared with healthy controls (n = 24).
The early component (initial CNV) is especially more negative in migraine
patients. Within the migraine group, 14 children with migraine without aura (mean
age 13.6 years) were compared with 11 healthy children (mean age 12.4 years).
Migraine children differ from healthy children in the same manner that adult
migraine patients differ from healthy adults. The CNV of five healthy children
did not differ from the CNV of their siblings suffering from migraine. We suggest
that there is a family-related cortical hypersensitivity which does not
necessarily lead to the development of migraine.
PMID- 10668127
TI - Acupuncture in headache.
PMID- 10668128
TI - Insecticidal activity of transgenic tobacco plants expressing both Bt and CpTI
genes on cotton bollworm (Helicoverpa armigera).
AB - Transgenic tobacco plants expressing both Bacillus thuringiensis (Bt)
insecticidal protein and cowpea trypsin inhibitor (CpTI) genes was used to
evaluate the insecticidal activity on the cotton bollworm (Helicoverpa armigera)
compared with transgenic tobacco with Bt insecticidal protein gene alone.
Mortality of first to third instar larvae fed on transgenic two genes tobacco for
three days was significantly higher than that fed on transgenic Bt tobacco. First
to fourth instar larvae fed on transgenic two genes tobacco continuously could
not survive until pupation. Second instar larvae were fed on transgenic tobacco
plants for three days and then were transferred to an artificial diet. The
efficacy of transgenic two genes tobacco on mortality, larvae weight, percentage
of pupation, and time to pupation were significantly higher than that of
transgenic tobacco with Bt insecticidal protein gene alone. The results with
transgenic tobacco as model plant were valuable for other crops both for the
enhancement of insecticidal efficacy and for the delay of insect adaptation to
transgenic Bt crops.
PMID- 10668129
TI - Cloning of Schistosoma japonicum Chinese strain 22.6kD membrane-associated
protein (Sj-22.6) gene and its overproduction on Escherichia coli.
AB - A 567bp DNA fragment was amplified from Schistosoma japonicum adult worm mRNA by
RT-PCR. Sequence analysis revealed that this fragment contained S. Japonicum
Chinese strain membrane-associated protein (Sj-22.6) gene. Then this gene was
cloned into the expression vector pGEX-4T, and subsequently expressed in
Escherichia coli. The recombinant GST-fusion protein was purified by glutathione
agarose affinity chromatography. Its molecular weight was about 48 kD. The yield
of expression was around 40 mg/L E.coli culture. The immunological test suggested
that the recombinant protein had good antigenity which could make a good basis
for the research of its immunological function in Schistosomiasis.
PMID- 10668130
TI - Purification and properties of genetic expressing product of thermostable
protease from Bacillus stearothermophilus HY-69.
AB - The thermostable metal protease gene from Bacillus stearothermophilus HY-69 had
been cloned and expressed in Bacillus subtilis MI113. The genetic expressing
product of the enzyme was purified by CM-cellulose chromatography. The product
shows homogeneity on PAGE. Its molecular weight is 27,000 +/- 1000 by SDS-PAGE
and Sephadex G100 filtration, respectively. The alpha-helix content of the
protease is estimated to be about 66%, the beta-turn about 28%, the random coil
about 6%, but not beta-sheet, calculated from the circular dichroism data. The
optimal temperature of the enzyme was 70 degrees C. When the enzyme was denatured
in 3 mol/L of Gdn--HCl in phosphate buffer pH6.0 for 20 min, it remained about
40% of original activity. It shows that it is rather resistant to heat and Gdn
HCl denaturation. Its conformational variety coursed by Gdn-HCl was investigated
by the far UV circular dichroism and fluorescence spectra. The results show that
the enzyme has more compact conformation and internal hydrophobility.
PMID- 10668131
TI - High level expression of the deleted and mutated urokinase-scFv fusion gene in
Escherichia coli.
AB - The fusion gene of a specific anti-human fibrinogen D-dimer scFv and low
molecular weight single chain urokinase (scu-PA-32K) was restricted, spliced, and
digested with exonuclease Bal31 to obtain a series of deletion mutants. Study of
their expressions in E.coli revealed that the key sequence which reduced its
expression level resided in the fragment from 841 to 851 bp, in which a tandem of
AGG codons (encoding arginine, rarely used in E.coli) existed. By means of PCR
mediated site-directed mutagenesis, we altered these two AGG codons to CGT
codons, which could be more efficiently translated in E.coli, and the expression
level turned out to be about 30% of the total bacterial proteins while that of
the natural gene was only 2%-3%.
PMID- 10668132
TI - Hirudin display on the surface of bacteriophage M13.
AB - Hirudin was fused to the N terminus of M13 minor protein gp3 (197-406) through a
linker GGGS by inserting both the hirudin gene and the gp8 signal sequence into
the modified phagemid vector pCANTAB 5V to construct pCANTAB 5G8-Hir. The
expressed fusion protein was directed by gp8 signal peptide into the periplasm
and assembled to the phage particle to form the hirudin-phage. The fusion protein
and fusion phage were detected with biotin-thrombin by Western blotting analysis.
Antithrombin activity analysis confirmed that the hirudin portion in the fusion
protein and fusion phage bear similar native conformation. The successful display
of hirudin on the surface of M13 phage laid a sound foundation for the further
study on directed evolution of antithrombotic proteins with altered properties.
PMID- 10668133
TI - Production of chimeric antibody in cells and larvae of silkworm.
AB - By using the recombinant baculovirus expression system, the chimeric antibody
against human small cell lung carcinoma was expressed in the cells and larvae of
silkworm Bomyx mori N (BmN). The chimeric antibodies produced in BmN cells and
larvae which were infected with recombinant viruses rNPVL2, rNPVH17 and dual
recombinant virus rNPVLH19 were detected by Western blot analysis. The co
expression products of heavy- and light-chain genes in silkworm larvae revealed
stronger immune binding activity than the single product of heavy or light chain
gene expression.
PMID- 10668134
TI - Construction of high ergosterol-producing yeast strains and study on the optimal
conditions for culture.
AB - High ergosterol-producing yeast strains were constructed by primary screening
isolation of haploid mutagenesis and protoplasts fusion. The fermentation
conditions of fused strain YEF-21 were studied. Under the optimal conditions,
i.e., the medium for fermentation consisted of 8% glucose 1% polypeptone 1% yeast
extract; initial pH nature; 60 mL broth/250 mL flask; inoculum volume 10%;
fermentation time 30 hours at 28 degrees C and 200 r/min; the comprehensive value
of biomass and ergosterol content of YEF-21 is 1.54 and 1.55 times that of the
parent strains YE227 and YE180, respectively. The fused strain YEF-21 is stable
enough genetically according to the analysis of genetic stability, and it is a
high ergosterol-producing strain that has prospect for application.
PMID- 10668135
TI - Studies on the callus cultures of Ginkgo biloba and its metabolites-ginkgolides.
AB - The production of ginkgolides in callus culture of Ginkgo biloba was reported.
The affection of some physical factors and chemical substances on the induction
and growth of calli was also investigated. A biologically quantitative method
(platelet aggregation induced by PAF) and HPLC were successfully used for the
determination of Ginkgolides A and B in all kinds of callus cultures. The result
showed that the content of Ginkgolides B in the callus cultures varies from
0.005% to 0.01%, which is one of the best results for the callus culture of
G.biloba in the world.
PMID- 10668136
TI - Somatic embryogenesis of Echinodorus orisis L. and the kinetic changes of the
endogenous hormones contents during the embryogenetic process.
AB - Somatic embryogenesis was achieved in young Leaf cuttings of Echinodorus orisis
L., an aquatic ornamental plant, in a short period (25 days). Among the
cytokinins and their combinations tested, 6-BA (1 mg/L) and Zt (1 mg/L) in MS
medium induced the highest efficiency (100%) of somatic embryogenesis, with a
maximum of 4.87 embryoids per explant. Roots instead of somatic embryos were
formed when NAA (0.5 mg/L) was added to MS medium containing Zt (1 mg/L). Matured
embryoids were germinated and rooted in MS medium with IAA (1 mg/L) after 5 days
cultivation. Seventy-two percent of the rooted plantlets transplanted survived in
the aquarium. The endogenous hormone contents in various stages of somatic
embryogenetic process were measured by HPLC. The concentrations of all the
hormones tested were about 2 times that of the cuttings from the untreated fresh
leaves after 10 days incubation. Meanwhile, the concentration of IAA presents two
peaks after 10 and 25 days of cultivation, respectively. The cytokinin (Zt and
ZR) peak, about 8 times more than CK, appeared in 15 days cultivation when the
heart-shaped embryos formed. The fluctuation of the GA3 concentration was very
similar to that of cytokinin. The ABA, however, remains stable at quite high
concentration after 10 days of cultivation.
PMID- 10668137
TI - Preparation of GFLV CP-gene cDNA probe labeled by photosensitive biotin and its
application in detection of GFLV.
AB - The cDNA of the GFLV CP gene amplified from clone pGAB5 by PCR was labeled by
photosensitive biotin. The probe sensitivity is 5 pg, and the detectable amount
of unlabeled GFLV cDNA was 10 pg by Dot-blot hybridization when the biotin
labeled cDNA was used as a probe. The results of detection for GFLV by probe have
positive correlation with those of ELISA. The minimum amount of grapevine tissue
for detection by probe was 100 times lower than that by ELISA. The seasons and
the position of grapevine leaves do not limit application of this method.
PMID- 10668138
TI - A comparison of human spermatozoa immunolabeling features using xenogenic
reagents for centrosomal proteins.
AB - The centrosome is an organelle essential to proper chromosomal migration and
normal cell growth. In the human, the centrosome is comprised of two centrioles
and the pericentriolar cytosol; its control of embryo cleavage processes derives
from its role as a locus for spindle organisation. At fertilisation, it is the
human sperm centrosome that is responsible for ordering these processes, as the
oocyte appears not to contain working centrosomal structures. Abnormalities in
fertilisation or early embryo cleavage could be related to impaired sperm
centrosome structure or function in some cases. While potential future treatments
of infertility due to a defective centrosome could involve use of a donor
centrosome to restore normal cell development, such an approach would depend on
accurate localisation of this organelle for subsequent transplantation. To locate
centrosomal components in the heads and tails of human spermatozoa, labeling was
performed on intact spermatozoa using antibodies of known specificity to highly
conserved centrosomal elements. Following general mapping of immunofluorescent
signals, unlabeled sperm were dissected to form head/tail sperm fragments which
were then separately tested. Distribution of centrosomal proteins in head and
tail fragments was assayed for each separation method. Three reagents were
compared: 1) rabbit anti-mitotic spindle protein (anti-MSP) antibody, 2) rabbit
polyclonal centriole-specific antibodies, and 3) mouse monoclonal anti-MPM-2 (a
centrosome phospoprotein) antibody. Of these, anti-MPM-2 antibody appeared to be
the most reliable, labeling centrosomal elements in 63% (n = 1,386) of treated
spermatozoa. Sequential utilization of n-butylamine to effect head/tail
separation followed by anti-MPM-2 antibody labeling was a satisfactory method of
centrosome localisation. Microextraction of centrosomes and pericentriolar matrix
identified by this method awaits further testing.
PMID- 10668139
TI - Ovarian cyst formation and congenital absence of the inferior vena cava: case
report.
AB - Congenital absence of the inferior vena cava (IVC) is a rare condition that
presents clinically as recurrent venous thromboses and leg ulcers. We report an
association with painful ovarian cysts in a 25 year old woman. The possible
pathophysiology and unique management issues posed by this case are presented.
PMID- 10668140
TI - Trisomy 21 fetus co-existent with a partial molar pregnancy: case report.
AB - BACKGROUND: Approximately 1 in 1,000 pregnancies in the United States are
complicated by the presence of a hydatidiform mole. A Medline search revealed no
reported cases of a trisomic fetus co-existent from 1966-1998. We present the
case of a patient, initially found to have hypertension, edema, and proteinuria
in the first trimester, and later found to have a partial molar gestation co
existent with a trisomy 21 infant. CASE REPORT: A 31-year-old female presented to
her family practitioner in the first trimester and was found to have hypertension
and proteinuria. A thorough work-up by a nephrologist revealed no cause. The
patient was transferred to the Maternal-Fetal Medicine Service at 26 weeks' and 1
day estimated gestational age. An amniocentesis revealed the presence of a fetus
with trisomy 21. At 27 weeks' and 3 days estimated gestational age, the patient
underwent a cesarean delivery for a non-reassuring fetal heart rate. Pathologic
examination of the placenta revealed the presence of a partial hydatidiform molar
pregnancy. CONCLUSION: The present account represents the first reported case of
a fetus with trisomy 21 co-existent with a partial hydatidiform mole.
PMID- 10668141
TI - Potential use of bioelectrical impedance analysis in the assessment of edema in
pregnancy.
AB - OBJECTIVE: To evaluate the validity of Bioelectrical Impedance Analysis (BIA) in
the assessment of edema in pregnancy. METHODS: A prospective study of healthy
women identified during the first trimester of pregnancy. From a pool of 200
eligible volunteers, BIA was conducted on 90 women during the rest of pregnancy
and postpartum period. RESULTS: The values for bioelectrical impedance in normal
pregnant women decreased gradually in the course of pregnancy, whereas a more
remarkable decrease in the values was noted in eight patients who developed
edema. The bioelectrical impedance (BI) changes correlated closely with body
weight changes. There was a strong relation between bioelectrical impedance
values and the degree of edema. The precedent decrease of the values before the
onset of edema was noted in seven of the eight patients with edema. CONCLUSION:
BIA can be a useful and practical method for the early detection and quantitative
assessment of edema in pregnant women.
PMID- 10668142
TI - Maternal and neonatal outcome in a monochorionic twin pregnancy complicated by
single intrauterine demise.
AB - Single fetal death in monochorionic pregnancies is believed to be associated with
increased risk of perinatal morbidity and mortality for the living twin and risk
of coagulopathy affecting the mother. In this report we present a case of single
intrauterine death in a monochorionic twin gestation diagnosed in the 28th week
of pregnancy.
PMID- 10668143
TI - Effects of conjugated estrogens and progestogen in surgically induced
endometriosis in oophorectomized rats.
AB - This study aimed to verify whether estrogen replacement alone or associated with
progesterone promotes the recurrence of experimental endometriosis in
oophorectomized rats. The procedure utilized for endometriosis induction was
adapted from the one described by Jones (1984). The rats were castrated three
weeks after the induction. Hormonal replacement was started 14 days after the
castration and was given for 24 days. One group received estrogen alone, another
received estrogen associated with medroxiprogesterone acetate, and a last one
received placebo. At the end of this study, the animals who received hormonal
medication showed recurrence of the disease. This fact was more evident in the
group that received estrogen alone. We concluded that estrogen alone leads to
recurrence of endometriosis in oophorectomized rats with surgically induced
endometriosis. The association of medroxiprogesterone promotes involutional
changes in the implants, and should be added upon the existence of a past history
of endometriosis.
PMID- 10668144
TI - A prospective study of induction of labor with prostaglandin vaginal gel:
ambulatory versus in-patient administration.
AB - BACKGROUND: Elective induction of labour is a common obstetrical practice.
Dinoprostone (prostaglandin E2 in triacetin base gel) has been shown to be an
effective and fairly safe agent for this purpose in inpatient settings. Currently
published work does not assess the effectiveness and safety of dinoprostone in an
ambulatory setting. OBJECTIVE: To assess the difference between inpatient and
outpatient use of dinoprostone for elective induction of labour with regard to
effectiveness, safety, length of hospital stay, and patient satisfaction.
METHODS: A prospective non-randomized study, in which two groups of low risk
obstetrical patients who were undergoing elective induction of labour were
studied. The outpatient group was drawn from Regina Health District while the
inpatient (control group) was drawn from Saskatoon. The maternal and fetal
morbidity was compared in both groups as well as the efficacy, length of hospital
stay and degree of patient satisfaction. RESULTS: There were statistically
significant reductions in the length of hospital stay and greater patient
satisfaction in the outpatient group. No difference was found in efficacy and
safety of prostaglandin use. CONCLUSIONS: The findings suggest that ambulatory
use of prostaglandin gel for induction of labour reduces the length of hospital
stay, and leads to greater patient satisfaction. Further randomized studies with
a larger number of patients are needed to evaluate the safety of this agent in an
ambulatory setting.
PMID- 10668145
TI - In vitro decidualization activity assay of human endometrial stromal cells.
AB - To address the need for a simple and reliable system for evaluating the effects
of bioactive substances on decidualization of endometrial stromal cells, we
designed and tested an assay for measuring decidualization activity. With our
assay, it is easy to examine the effects of various bioactive substances on
endometrial stromal decidualization. For example, as shown in this study, it is
now clear that neither RANTES nor gonadotropin releasing hormone agonist has any
effect on endometrial stromal decidualization. Our simple assay has also made it
possible to evaluate individual stromal decidualization activities and the
regulation of decidualization.
PMID- 10668146
TI - Transvaginal sonographic evaluation of endometrial polyps: a comparison with two
dimensional and three dimensional contrast sonography.
AB - Endometrial polyps are a frequent cause of menorrhagia and are often associated
with infertility. Routine transvaginal (TV) ultrasound evaluation may detect
intrauterine anomalies. Sonographic evaluation of the endometrium after uterine
cavity distention, called hystero-sono-salpingography (HSSG), improves the
resolutive effectiveness of TV sonography. Recently the development of three
dimensional (3D) scanning of the uterine cavity has provided accurate images. The
purpose of this study was to compare conventional 2D and 3D scanning of the
uterine cavity with or without saline contrast medium in the detection and
evaluation of focal endometrial polyps. Twenty-three patients out of 642 women
suggestive for intrauterine anomalies at routine TV sonogram were examined by 2D
and 3D sonography before and after intrauterine saline contrast medium.
Sonographic appearance was verified by hysteroscopic and histologic evaluation.
Two-dimensional TV sonography diagnosed 23 polyps versus 16 confirmed at
hysteroscopic and histologic examinations, revealing a specificity of 69.5%; 2D
TV HSSG diagnosed 17 polyps, with a specificity of 94.1%; 3D TV sonography
diagnosed 18 polyps, with a specificity of 88.8%; 3D HSSG diagnosed 16 polyps
according to hysteroscopic and histologic findings, with a specificity of 100%.
HSSG has been demonstrated to be an effective and suitable method in the
detection of intrauterine anomalies, particularly with 3D sonography.
PMID- 10668147
TI - Correlation between histological grading and growth-related factors in human
endometrial adenocarcinomas.
AB - In order to clarify biological significance of histological grading of malignant
tumors, several "growth-related factors" were examined and compared in human
endometrial adenocarcinomas with different histological grades. Growth fraction
(estimated by Ki-67 immunostain) and cytoplasmic bcl-2 and nuclear p53
overexpression were estimated immunohistochemically in 40 cases of carcinomas
with different histological grades. When the grades were divided simply into 3
tiers, G1 (well); G2 (moderately); G3 (poorly differentiated), essentially no
differences were found between histological grade and growth fraction. In
addition, bcl-2 expression, which is known to negatively affect Ki-67 expression,
had no correlation with histological grade. Only nuclear p53 overexpression,
known to reflect gene alterations, tended to be more common in the higher grade
groups. The results indicate that growth fraction does not correlate well with
histological grade of human endometrial adenocarcinoma, as far as examined by Ki
67 and bcl-2 immunostains. The p53 gene status may have some significance in
histological grade of human endometrial adenocarcinoma, although its role is not
always clearly understood.
PMID- 10668148
TI - The management of breech presentation in the last three decades.
AB - In order to evaluate the changes in management of breech presentation during the
last three decades, a retrospective analysis of the "Alexandra" Hospital records
was undertaken. The years, 1965, 1975, 1985, 1995 and finally 1997 were used as
pilot years for this purpose. The cesarean section, breech presentation and
breech cesarean section rates were calculated for each year. Specific breech
cesarean section rates in respect to birth weight and parity as well as perinatal
mortality rates were also recorded for each pilot year. The overall cesarean
section rate rose from 8.0% in 1965 to 25.2% in 1995 and 25.1% in 1997 while the
breech cesarean rate climbed from 16.9% in 1965 to 74.1% in 1995 and 72.3% in
1997, irrespective of birth weight. A trend towards vaginal delivery of breeches
in multiparous women till 1985 became less apparent in later years. During the
same period, a marked decrease of the perinatal mortality rate was observed from
70.1/1000 in 1965 to 36.6/1000 in 1997. In conclusion, a more than four-fold
increase of the breech cesarean section rate was apparently rewarded by a two
fold decrease in perinatal mortality.
PMID- 10668149
TI - Effectiveness of "core biopsy" by the mammotome device for diagnosis of
inflammatory carcinoma.
AB - OBJECTIVE: To assess the usefulness of "Mammotome" device for the diagnosis of
the inflammatory breast carcinoma. MATERIAL AND METHODS: We studied 6 patients,
aged 43-79 years, with clinical evidence of inflammatory breast carcinoma. We
compared two sampling techniques, a cytologic one by Fine Needle Aspiration (FNA)
and a microhistologic one by "Mammotome". RESULTS: Cytologic sampling by FNA
permitted certain diagnosis of malignant lesions in 2 out of 6 cases, while the
"Mammotome" device confirmed the correct diagnosis in all 6 considered cases.
CONCLUSIONS: The "Mammotome" device proved more useful in the diagnosis of
inflammatory breast carcinoma than FNA and it can be a valide alternative to
surgical biopsy.
PMID- 10668150
TI - Red blood cell zinc protoporphyrin measurement for assessment of peripartum iron
deficiency.
AB - OBJECTIVE: To study the effectiveness of the rapid red blood cell zinc
protorphyrin (RBC-ZPP) test for the detection of women with iron-deficiency
anemia in the peripartum period. DESIGN: Blood was drawn prospectively from 150
healthy parturient women upon admission to the labor and delivery room and 72
hours after delivery. Concentration of RBC-ZPP was measured and correlated with
hemoglobin level (p = 0.001), mean corpuscular volume (p = 0.002), hematocrit (p
= 0.0001), platelet count (p = 0.002), and serum iron (p = 0.0001), serum
ferritin (p = 0.0001) and serum transferrin (p = 0.0001) concentrations. RESULTS:
RBC-ZPP concentration showed a significant increase from pre-delivery to 72 hours
post-delivery. This change correlated significantly with the changes in all the
other parameters studied. CONCLUSION: The RBC-ZPP test is a reliable, rapid, easy
to-perform, and inexpensive method of screening low-risk women, after uneventful
vaginal delivery, for iron deficiency.
PMID- 10668151
TI - Laparoscopic ultrasonic operative technique in surgery of women with endometrial
cancer: 2 case reports.
AB - The aim of this study was to introduce a new laparoscopic ultrasonic technique in
the laparoscopy-assisted surgical staging of endometrial cancer. The entire
laparoscopic phase of the laparoscopic hysterectomy and pelvic lymph node
dissection was performed using a 5 mm ultrasonic scalpel and shears. Ultrasonic
activated technology was easy to use and allowed the surgeon to perform
laparoscopic hysterectomy and lymphadenectomy close to important pelvic
structures safer than in other operative techniques. This is only a case report
and a larger study to confirm the advantages of the laparoscopic operative
technique in surgery of women with uterine malignancy is needed.
PMID- 10668152
TI - Preterm delivery: predictive value of cervico-vaginal fetal fibronectin.
AB - OBJECTIVE: This study aimed to evaluate the risk of preterm delivery in the
asymptomatic obstetric population of L'Aquila by means of fetal fibronectin
immunoassay in cervicovaginal secretions. METHODS: In this prospective study, 60
asymptomatic pregnant women at low-risk for preterm delivery were followed-up.
Fetal fibronectin cervical swabs from the esocervix and posterior vaginal fornix
were obtained every second week from 24 to 36 weeks of gestation. Fetal
fibronectin concentrations were measured by an enzyme-linked immunosorbent assay
with a cutoff level set at 50 ng/ml. RESULTS: Twelve patients (20%) had at least
one positive fetal fibronectin test result. Six women in our study group (10%)
were delivered spontaneously < 37 weeks; 4 of these (66%) had at least one
positive fetal fibronectin test result (positive predictive value: 33%;
sensitivity: 66%) and 3 of these women (75%) had a positive test result between
24 and 26 weeks. The remaining 8 patients with at least one positive fetal
fibronectin test were delivered at term or post-term. Forty-eight women always
had negative tests and 46 (95.8%) of these were delivered at term (specificity
82%), whereas 2 (4.2%) were delivered prematurely. The negative predictive value
of fetal fibronectin as a predictor of term delivery in this low-risk population
in 95% with odds ratio = 11.5 (95% confidence interval 1.44 to 110.4), relative
risk = 8 (95% confidence interval 1.38 to 59.2) and Fisher Exact Test p < 0.024.
CONCLUSION: In a population of asymptomatic patients at low risk for prematurity,
the occurrence of a positive cervical or vaginal fetal fibronectin test result
defines a subgroup at increased risk for preterm delivery, mostly at low
gestational age.
PMID- 10668153
TI - Our experience in laparoscopic diagnosis and management in women with chronic
pelvic pain.
AB - Chronic pelvic pain (CPP) still remains a serious problem in everyday
gynecological practice. The aim of this study was to prospectively estimate the
occurrence of pelvic varicosities in women with CPP and also to report our
experience in the establishment of diagnosis and management of patients with CPP.
We examined 264 premenopausal women aged 18 to 42 years referred to us for
chronic constant pelvic pain of at least 6 months duration and with incomplete
relief by previous treatments. The women were divided into 4 groups in proportion
to their parity. The results of our study demonstrate that pelvic congestion is a
common finding in women with chronic pelvic pain especially in multigravidas.
Based on our findings we support laparoscopic resetting of the uterus as an
option for treatment in patients desiring maintenance of future fertility.
PMID- 10668154
TI - A note on the functions of bc1-2 in human solid tumors in situ.
AB - Dual functions of bc1-2 product, (1) inhibition of apoptosis and (2) inhibition
of cell growth, were analyzed in human endometrial adenocarcinoma tissue using
serial tissue sections and immunohistochemical and histochemical procedures. As
conclusion, bc1-2 product was speculated to have at least two functions; (1)
suppression of apoptosis of cells in G0 phase, and (2) blocking the entrance of
G0 cells into cell division cycle.
PMID- 10668155
TI - Immunohistochemical evaluation of apoptosis in placentae from normal and
intrauterine growth-restricted pregnancies.
AB - OBJECTIVE: To investigate the extent of apoptosis within the human placenta in
tissues from normotensive term pregnancies and those complicated by intrauterine
growth-restriction (IUGR). METHODS: A total of 18 placentas, 10 obtained from
uncomplicated term gestations and 8 from intrauterine growth restricted fetuses
were included in this study. Apoptosis was identified using a terminal
deoxynucleotidyl transferase-mediated deoxyuridine triophosphate nick end
labeling technique (TUNEL, Boehringer, Mannheim, Germany) in paraffin-embedded
sections. RESULTS: Apoptosis was predominantly detected in the villous
trophoblast and stromal tissue. There were no differences in the incidence of
apoptosis in different parts of the same placenta. The apoptotic index in
placental tissue from uncomplicated pregnancies was 0.93 +/- 0.12. Significantly
more apoptotic nuclei were detected in the placental tissue from IUGR gestation
(4.2 +/- 2.96, p < 0.01). CONCLUSION: These results might point toward a possible
role of apoptosis in the pathophysiology of intrauterine growth-restriction.
PMID- 10668156
TI - Relationship between unexplained infertility and human leukocyte antigens and
expression of circulating autogeneic and allogeneic antisperm antibodies.
AB - PURPOSE: The association between unexplained infertility, human leukocyte
antigens (HLA) and expression of circulating antisperm antibodies was studied in
52 couples with unexplained infertility and 15 infertile and 9 fertile couples.
METHODOLOGY: Evaluation parameters included Terasaki's HLA
microlymphocytotoxicity test, circulating antisperm antibodies using
immunofluorescence technique. RESULTS: Fifty-two couples (8.7%) out of 600
consecutive clinic attendants had unexplained infertility. Unexplained
infertility was associated with circulating antisperm antibodies (22 versus 13
and 0% for men and 18.5 versus 13 and 0% for women). HLA class 1 B6 and B52 and
Cw7 and HLA class 2 DR4 and DR6 and sharing of HLA B6, DR4 and DR6 were found
more in couples with unexplained infertility. Combined expression of antisperm
antibodies by couples, demonstrated more homozygosity for HLA B6 and DR4.
CONCLUSION: Homozygosity for these antigens, B6, DR4 and DR6, may enhance the
expression of antisperm antibodies, and cause infertility.
PMID- 10668157
TI - Intramuscular versus vaginal administration of progesterone for luteal phase
support after in vitro fertilization and embryo transfer. A comparative
randomized study.
AB - A total of 156 patients were randomly treated with exogenous natural progesterone
(intramuscularly, 50 mg/day) and vaginal gel (90 mg/day) P or nothing (Controls)
from the day before embryo transfer (ET) for two weeks. In case of positive beta
HCG, the treatment was continued for 12 weeks. Plasma P and 17 beta-Estradiol
concentrations were estimated and compared with the control not supplemented
group. Both treatments were able to increase significantly the luteal plasmatic
values of P versus controls. The ongoing pregnancy and the living birth rates per
transfer were significantly higher in the patients supplemented with
intramuscular P than in those treated with vaginal gel P. The intramuscular
natural P appears the most suitable route of administration for luteal phase
support in IVF-ET procedures.
PMID- 10668158
TI - Disposition of pesticides and toxicants in the human reproductive system in cases
of acute poisoning.
AB - The aim of this study was to estimate the penetration of some of the pesticides
and toxicant substances in the human reproductive system. This knowledge is
valuable because of the possible adverse influence of these substances on the
human reproduction system and the development of the foetus during pregnancy. The
existing data is mainly concerned with the results of experimental studies on
animals or epidemiological studies. Here we report data concerning the
disposition of several toxic xenobiotics (pesticides and solvents) in the tissues
of the human reproductive system as well as in other organs and glands. Data was
collected from cases of acute poisonings and derived mostly from autopsy
materials. Xenobiotics were found to penetrate sampled tissues such as the
testes, ovaries, epididymis, uterus, thyroid gland, as well as other human
tissues. Further studies will clarify and confirm peculiarities of the
penetration of a wide range of substances in various body tissues and will be the
base of the estimation of the role of these toxicants in human reproductive
ability and the outcome of pregnancy in humans.
PMID- 10668159
TI - D-dimer after delivery in uncomplicated pregnancies.
AB - D-dimer is now widely used as a coagulation marker. During pregnancy the D-dimer
level increases until term even in uncomplicated pregnancies. The aim of the
study was to establish the D-dimer immediately after delivery in uncomplicated
pregnancies. A rapid immunoturbidimetric assay for D-dimer determination was
employed in 100 consecutive deliveries. D-dimer level increased significantly in
all women after delivery (increase from 1 to more than 10 times over the normal
range). CONCLUSION: An increase in fibrinolysis is associated with pregnancy and
delivery, and D-dimer level must be interpreted only in association with other
clinical, laboratory and instrumental methods when pathological conditions (e.g.
pulmonary embolism, deep vein thrombosis or disseminated coagulation) are
suspected.
PMID- 10668160
TI - Usefulness of a 12-month treatment with finasteride in idiophathic and polycystic
ovary syndrome-associated hirsutism.
AB - OBJECTIVE: Hirsutism is considered as a skin disease due to increased 5 alpha
reductase activity in the pilosebaceous unit and finasteride is a drug that
inhibits this enzymatic activity. This study showed the effectiveness of a
chronic treatment with a selective 5 alpha-reductase inhibitor, finasteride, in
idiopathic and PCOS-associated hirsutism. METHODS: Finasteride was administered
orally at a daily dose of 5 mg for a period of 12 months to 20 women with IH and
20 women with PCOS. MAIN OUTCOME MEASURES: Each group was submitted to clinical
(with Ferriman-Gallwey method) and serum hormonal (FSH, LH, 17 beta-estradiol,
total and free T, delta 4-androstenedione, DHEAS; dihydrotestosterone, 3 alpha
androstanediol glucuronide) studies at baseline and after 3, 6 and 12 months of
treatment. RESULTS: After 3 months of finasteride treatment, a significant
decrease in the average hirsutism scores was recorded both in IH (p < 0.0001) and
PCOS patients (p < 0.0001). A progressive significant decrease of hirsutism score
was observed in IH patients after 6 and 12 months (p < 0.002) and in PCOS
patients after 6 but not 12 months. In fact, the maximal therapeutic effect on
the hirsutism was obtained after 12 months in the IH and 6 months in PCOS group.
PMID- 10668161
TI - Benefits of antibiotic prophylaxis in laparoscopic gynaecological surgery.
AB - The prevention of infectious complications by antibiotic prophylaxis has made
traditional or laparoscopic surgery much safer but at the same time has
contributed to an uncontrolled and often irrational use of every kind of
antibiotic. In this study we wanted to show that often mini-invasive surgery like
laparoscopy can be practised without the use of antibiotics. Thus,
postoperatively several patients undergoing laparoscopic, diagnostic and
operative interventions were followed-up. The results showed that subjects
without antibiotic therapy did not have any symptomatology that could be ascribed
to bacterial infections. In conclusion this study has demonstrated that
laparoscopic surgery, especially without any complications, should follow the
elementary rules of surgical techniques and surgical asepsis and that antibiotic
prophylaxis is not always necessary.
PMID- 10668162
TI - Vulvar neoplasia and search for human papillomavirus 16 and 18 genetic
information. Short communication.
AB - The presence of HPV 16 and 18 is frequent in cases with vulvar carcinomas and
intraepithelial neoplasias.
PMID- 10668163
TI - Inhibitory effect of exogenous oxytocin on ACTH and cortisol secretion during
labour.
AB - Complex mechanisms which are still not completely defined, are responsible for
the spontaneous onset of labour: an essential role is attributed to endocrine
factors. A massive increase, even three times higher than normal physiological
values of ACTH and cortisol, has been reported during labour. Similar behaviour
has also been recorded for oxytocin at the end of pregnancy as well as during
labour. The relationship between oxytocin and the adrenal axis are still debated
thus the goal of our study was to attempt to clarify this rapport. Sixty-two
women at the end of a term-pregnancy agreed to participate in this study: 46 were
innoculated with oxytocin (syntocinon) every 20 minutes for 1 hour; 16 were
administered a natural placebo every 20 minutes for 1 hour (control group). ACTH
and cortisol values from plasma samples were taken every 20 minutes and analyzed.
Our results demonstrated an inhibitory effect of exogenous oxytocin on ACTH and
cortisol release. This inhibitory effect, as shown by our results, is time and
dose-related. High oxytocin levels, as during exogenous infusion, could induce an
effect opposite a normal physiologic one.
PMID- 10668164
TI - Penis, bladder and uretral agenesis associated with anorectal malformation in a
living male neonate. Case report.
AB - Aphallia is a very rare congenital malformation, with an occurrence of 1 in every
30 million births. In the international literature about 75 cases have been
indicated as of today. The authors report and discuss the case of one neonate,
born from a monoamniotic twin delivery, suffering from agenesis of the penis,
anorectal malformation with a fully formed scrotum with 2 normal gonads and
absence of bladder and urethra and both kidneys.
PMID- 10668165
TI - Outcome of stimulated in vitro fertilisation (SIVF) using clomiphene citrate and
human menopausal gonadotropin in different infertility groups.
AB - A prospective study was undertaken to evaluate the efficacy of stimulated in
vitro fertilization (SIVF) using Clomiphene Citrate and hMG in different
infertilities. The analysis was applied to the first 81 cycles over a period of 9
months in the years 1994-1996 in Sheffield Fertility Centre (SFC). The female
patients included in this study were under 40 years of age, and their FSH and LH
values were < 10IU/L. Mild and moderate male factor infertilities were included.
For tubal factor infertility 16 cases were included with an implantation rate of
0%. The unexplained factor infertility included 33 cases with an implantation
rate per embryo transfer (ET) of 41%. For male factor infertility there were 18
cases with an implantation rate per ET of 42%. Out of 3 cases in the ovulatory
factor group none reached ET with 0% implantation. For multiple factor
infertility 11 cases were included with a 0% implantation rate. The overall
implantation per embryo transfer was 27%, while the implantation per cycle
started was 15%. We conclude that there are certain infertility factors, i.e.
unexplained infertility and mild male factor, which can have good results in IVF
using CC/hMG only.
PMID- 10668166
TI - Hematocolpos by imperforated hymen. Case report.
PMID- 10668167
TI - Does maternal drug ingestion cause megacystis microcolon intestinal
hypoperistalsis syndrome? II. Bromide trial.
AB - PURPOSE: Megacystis Microcolon Intestinal Hypoperistalsis Syndrome (MMIHS) is a
congenital disease, and the etiology of the disease is unclear. It is speculated
that maternal ingestion of some drugs during pregnancy and degeneration of smooth
muscle cells in the fetus may be an etiologic factor. In this study we aimed to
investigate the effect of maternal ingestion of bromide on the fetal bladder and
colon in pregnant rats. METHOD: We separated animals into a bromide group
including 30 rats and a control group with 14 rats. Nothing was given to the
control group during pregnancy. Intraperitoneally 8 mg/kg/day bromide was given
to the study group from the 6th to 12th day of pregnancy. All of the rats were
sacrificed on the 20th day of pregnancy. Histopathological examination of fetal
colons and bladders was performed. RESULTS: In the bromide group, an increase in
the colon and bladder diameter, an increase in muscle atrophy in the colon and
bladder wall, an increase in vacuolar degeneration in the muscles of the bladder
and colon wall, and a significant decrease in ganglion cell numbers in the
myenteric plexus of the colon and bladder were determined. CONCLUSION: In our rat
model, we found histological structural changes in the rats' colon and bladder
walls as a result of using bromide on the 6-12th days of pregnancy similar to
pathological findings found in some of MMIHS patients' bowels and bladders.
PMID- 10668168
TI - Does maternal drug ingestion cause megacystis microcolon intestinal
hypoperistalsis syndrome? III. Ethanol trial.
AB - PURPOSE: Megacystis Microcolon Intestinal Hypoperistalsis Syndrome (MMIHS) is a
congenital disease, and the etiology of the disease is unclear. It is speculated
that maternal ingestion of some drugs during pregnancy may be an etiologic
factor. In this study we aimed to investigate the effect of maternal ingestion of
ethanol on the fetal bladder and colon in pregnant rats. METHODS: We separated
animals into an ethanol group including 30 rats and a control group with 14 rats.
Nothing was given to the control group during pregnancy. Orogastrically 2 cc/day
30% ethanol was given to the study group from the 6th to 12th day of pregnancy.
All of them were sacrificed on the 20th day of pregnancy. Histopathological
examination of the fetal colon and bladder was performed. RESULTS: In the ethanol
group a significant decrease in the colon and bladder diameter, a significant
decrease in the thickness of the colon and bladder wall, an increase in vacuolar
degeneration in the muscles of the bladder wall, an increase in connective tissue
proliferation among the muscles of the bladder, a significant decrease in the
number of ganglion cells in the myenteric plexus of the colon and a significant
decrease in the thickness of the bladder tunica muscularis were determined.
CONCLUSION: In our rat model we found histological structural changes in the
rats' colon and bladder wall similar to a pathological finding found in some of
the MMIHS patients' bowel and bladder as a result of using ethanol on the 6th
12th days of pregnancy.
PMID- 10668169
TI - Synthesis, binding affinity and selectivity of new beta 1- and beta 2
adrenoceptor blockers.
AB - The synthesis of a new series of sesamol derivatives with beta-adrenergic
blocking activity is described. The affinity and selectivity of these compounds
for beta 1- and beta 2-adrenoceptors were studied in comparison with those of ICI
118551 and propranolol. Some of the synthesized compounds show very good affinity
for the beta 2-receptors of rat lung membranes and two of them provide
interesting selectivity.
PMID- 10668170
TI - Antimycobacterial activity of new ortho-, meta- and para-toluidine derivatives.
AB - Novel toluidine derivatives are described. Some of them showed an interesting in
vitro activity against Mycobacterium tuberculosis, M. smegmatis, M. marinum, M.
gordonae, and M. avium. Some of them were more active than Streptomycin and
Isoniazid, which were used as controls, against M. avium and M. gordonae. In
particular, we confirm the good activity of biphenyl derivatives.
PMID- 10668171
TI - Escin in pharmaceutical oral dosage forms: quantitative densitometric HPTLC
determination.
AB - A practical and reliable method for the quantitative determination of escin in
pharmaceuticals was developed. The TLC-densitometric determination was performed
without using spray or dipping reagents in order to provide a more rapid and
simple analytical procedure. Chromatographic separations were obtained on
analytical HPTLC silica gel plates and the elution was made with 3.5:4.5:2 PropOH
ethyl acetate-water (v/v/v). Densitometric analysis was performed directly at 212
nm, corresponding to lambda max of escin obtained by in situ-scanning. A second
degree polynomial regression relationship was found between the peak areas and
the amounts of the escin standard deposited in the range 1.15-6.90 micrograms.
The method is specific, accurate and reliable and was applied successfully to the
quantitative determination of escin in commercial samples.
PMID- 10668172
TI - Docetaxel in combination with epirubicin in metastatic breast cancer:
pharmacokinetic interactions.
AB - Epirubicin (75 mg/m2) and docetaxel (75 mg/m2) were administered to 16 patients
affected by metastatic breast cancer following two different schedules: (1)
docetaxel as infusion administered 1 h after epirubicin administration (schedule
A); and (2) docetaxel as infusion immediately (10 min) after the end of
epirubicin i.v. bolus administration (schedule B). Experimental non-compartmental
analyses such as AUC and Css, were affected very little by the drug combination,
irrespective of whether the administration of docetaxel was immediately after the
epirubicin bolus (10 min) or delayed (1 h). However, serum levels showed evidence
of transient drug interaction: in schedule A, docetaxel infusion was associated
with a transient increase of plasma epirubicin in correspondence with Cssmax of
docetaxel. Bi-compartmental analysis showed a significant difference in
epirubicin clearance between protocols A and B. It is suggested that polysorbate
80, used in minimal amounts to formulate docetaxel, may interfere with epirubicin
plasma level.
PMID- 10668173
TI - Synthesis of 1,2-benzisothiazole derivatives and investigation of their putative
histaminergic activity.
AB - Some new 2-(1,2-benzisothiazol-3-yl)ethylamine derivatives were synthesised and
their putative histaminergic activity was investigated in in vitro
gastrointestinal and cardiac preparations. In the isolated guinea pig duodenum,
all the compounds induced a tetrodotoxin- and atropine-sensitive contractile
activity, which was minimally affected by mepyramine in the case of the compound
2-(1,2-benzisothiazol-3-yl)ethylamine. In the same tissue, all the compounds were
devoid of any H3 receptor agonistic or antagonistic activity, but caused a
nicotinic and/or 5-HT3 receptor activation. None of these compounds induced any
histamine H2 agonistic or antagonistic activity in the isolated guinea pig
gastric mucosa or in the isolated papillary muscle. On this latter substrate, the
compound N,N,N-trimethyl-2-(1,2-benzisothiazol-3-yl)ethylammonium iodide induced
a positive inotropic activity, apparently due to a release of catecholamines.
These results demonstrate the substantial inability of 1,2-benzisothiazole
derivatives to interact with histamine receptors in functional tests. These
compounds, however, possess gangliomimetic properties, related to the activation
of 5HT3 and/or nicotinic receptors.
PMID- 10668174
TI - Synthesis and analgesic profile of novel N-containing heterocycle derivatives:
arylidene 3-phenyl-1,2,4-oxadiazole-5-carbohydrazide.
AB - This paper describes recent results of a research program aimed at the synthesis
and pharmacological evaluation of new heterocyclic N-acylhydrazone (NAH)
compounds, belonging to the arylidene (3-phenyl)-1,2,4-oxadiazolyl-5
carboxyhydrazide (8a-p) series. These compounds were structurally planned by
applying the molecular hybridization strategy on previously described arylidene 1
phenylpyrazole-4-carbohydrazide (5) derivatives, considered as lead-compounds,
which present potent analgesic properties. The analgesic profile of the title
compounds 8a-p, evaluated in the model of abdominal constrictions induced by
acetic acid, showed that the 4-methoxybenzylidene derivatives 8c and 8k were the
most active ones, exhibiting a relative analgesic activity comparable with that
of dipyrone 1 used as standard.
PMID- 10668175
TI - Formulation of a neutral solution of ciprofloxacin upon complexation with
aluminum.
AB - Clear solutions of 0.5 and 1.0% ciprofloxacin (CF) of pH 7.2 were prepared by the
addition of aluminum chloride hexahydrate (AlCl3.6H2O) in the molar proportion
CF:AlCl3.6H2O (3:1). Minimum inhibitory concentrations (MIC) of these solutions
were the same as an equimolar solution of CF.HCl. Solutions exhibited good
physical, chemical and microbiological stability and satisfactorily overcame an
ocular irritation test on rabbits.
PMID- 10668176
TI - Synthesis and antimycobacterial activity of some N1-[1-[3-aryl-1-(pyridin-2-, 3-,
or 4-yl)-3-oxo]propyl]-2- pyridinecarboxamidrazones.
AB - N1-[1-[3-aryl-1-(pyridin-2,3-, and 4-yl)-3-oxo[propyl]-2-
pyridinecarboxamidrazone derivatives were synthesized and tested for their in
vitro antimycobacterial activity. Some compounds showed interesting activity
against a strain of Mycobacterium tuberculosis and a strain of Mycobacterium
avium.
PMID- 10668177
TI - Synthesis and antinociceptive activity of (1-benzyl-2(3H)-benzimidazolon- 3-yl)
acetic acid derivatives.
AB - Eight (1-benzyl-2(3H)-benzimidazolon-3-yl)acetic acid derivatives have been
synthesized and tested for antinociceptive activity in this study. All compounds
but one, at the oral dose of 100 mg/kg were comparable with aspirin. Ethyl (1
benzyl-2(3H)-benzimidazolon-3-yl)acetate (3), 4-[(1-benzyl-2(3H)-benzimidazolon-3
yl)acetyl]morpholine (6a) and 1-[(1-benzyl-2(3H)-benzimidazolon-3
yl)acetyl]pyrrolidine (6b) have shown more potent antinociceptive activity than
others.
PMID- 10668178
TI - Investigations on the synthesis and pharmacological properties of amides of 7
methyl-3-phenyl-1-[2-hydroxy-3-(4-phenyl-1-piperazinyl)propyl]-2,4- dioxo-1,2,3,4
tetrahydropyrido[2,3-d]-pyrimidine-5-carboxylic acid.
AB - Synthesis of amides of 7-methyl-3-phenyl-2,4-dioxo-1,2,3,4- tetrahydropyrido[2,3
d]pyrimidine-5-carboxylic acid (6-10) and their 1-[2-hydroxy-3(4-phenyl-1
piperazinyl)propyl] derivatives (11-15) are described. Some of them displayed
strong analgesic activity.
PMID- 10668179
TI - 4-quinazolinones: synthesis and reduction of prostaglandin E2 production.
AB - We synthesized and evaluated the anti-inflammatory activity of a series of 4
quinazolinone derivatives. Two approaches were used to yield the title compounds.
A first group of quinazolinone derivatives was obtained by the appropriate
substituted anthranilates. A second group of quinazolinone compounds was prepared
through the benzoxazin-4-ones intermediate. The pharmacological results reveal
that the synthesized derivatives exhibit a significant anti-inflammatory effect
in an experimental ocular inflammation model. In fact, all the tested compounds
lowered the prostaglandin E2 (PGE2) production with respect to the control group
(P < 0.05). The 3-cyclohexyl-6-chloro-quinazolin-4(3H)-one and 3-cyclohexyl
quinazolin-4(3H)-one derivatives were the most active compounds. These compounds
significantly reduced PGE2 levels even more than the reference drug tolmetin and
significantly lower protein concentration and polymorphonuclear leukocytes number
compared to the control group (P < 0.05). Therefore, these compounds may be
useful to prevent ocular inflammatory reactions.
PMID- 10668180
TI - Synthesis and biological activity of pseudopeptides inhibitors of Ras farnesyl
transferase containing unconventional amino acids.
AB - A study was performed on the structure-activity relationships of a series of
phenol derivatives, CVFM analogs, derived from the two most active compounds of a
first series (1A and 1B) of inhibitors of Ras farnesyl transferase (FTase) that
we have recently described. We report the synthesis and the activity of a second
series of compounds in which the phenylalanine residue was replaced by
unconventional aromatic and non-aromatic amino acids, with varying electronic,
lipophilic, steric and conformational properties. The compounds showed to be
significantly less active than reference compounds against FT, with the only
exception of derivative 3A (IC50 = 3 microM), which is slightly more active than
1A but not 1B. Subsequently we tested the effects of compounds 1A, 1B and 3A, 3B
on the anchorage-dependent growth of two epithelial cell lines of rats, FRTL-5
and the same line v-Ha-ras transformed. Compound 3A derived from lead compound
1A, showed an appreciable selectivity against transformed cells. In contrast,
compounds derived from derivative 1B had only a modest cellular activity.
PMID- 10668181
TI - Synthesis of various analog derivatives of ORG13514 as 5-HT1A ligands.
AB - In connection with the development of new potential 5-HT1A ligands, multistep
synthesis of N-substituted-3-aminomethyl-2,3-dihydro-1,4-dioxinol[2,3-b]pyridin e
derivatives as ORG13514 analogs are described. Their biological activity as 5
HT1A type ligands is reported and compared with ORG13514 affinity and selectivity
for 5-HT1A receptors.
PMID- 10668182
TI - Sterically controlled regiospecific heterocyclization of 3-hydrazino-5-methyl
1,2,4-triazino[5,6-b]indole to 10-methyl-1,2,4-triazolo[4',3':2,3[1,2,4
triazino[5,6-b]indoles.
AB - 3-Hydrazino-5-methyl-1,2,4-triazino[5,6-b]indole underwent sterically controlled
regiospecific heterocyclizations with a variety of one-carbon cyclizing agents to
give the sterically more favored linearly annulated 10-methyl-1,2,4
triazolo[4',3':2,3[1,2,4-triazino[5,6-b]indoles rather than the sterically less
favored angularly annulated 10-methyl-1,2,4-triazolo[3',4':3,4]1,2,4-triazino[5,6
b]indoles. The assigned structures were corroborated by comparison with
unequivocally synthesized authentics, chemical and spectral data. The
antimicrobial activity of some of the prepared compounds was investigated.
PMID- 10668183
TI - Structure-activity studies on nociceptin/orphanin FQ: from full agonist, to
partial agonist, to pure antagonist.
AB - A heptadecapeptide (Phe-Gly-Gly-Phe-Thr-Gly-Ala-Arg-Lys-Ser-Ala-Arg-Lys-Leu-Ala
Asn-Gln) was identified from rat brain and from porcine brain as a ligand for
OP4, a new G-protein coupled receptor that is similar in sequence to opioid
receptors. The OP4 receptor is widely expressed in the nervous system where it
mediates a broad range of physiological functions. The new peptide, nociceptin
(NC), has a primary sequence recalling that of opioid peptides. Despite the
homologies (a) of the OP4 receptor with known opioid receptors, especially the
OP2 (kappa) receptor, and (b) of NC with opioid peptides, particularly dynorphin
A, the two biological systems have different anatomical locations and chemical
requirements for activation. NC does not bind to opioid receptors, and mammalian
opioid peptides do not interact with the OP4 receptor. The presence of Phe in
position 1 and Arg in position 8, appear to be instrumental to exclude NC from
interacting with the opioid receptors. Contrary to opioid peptides which strikly
require Tyr in position 1, the active core that activates the OP4 appears to be
towards the centre of the peptide molecule and includes Phe4. Based on the
message/address model, several changes have been made in the N-terminal
tetrapeptide Phe-Gly-Gly-Phe (message) and a few also in the C-terminal of the
template NC(1-13)-NH2, a fragment that acts as a full agonist both in vitro and
in vivo. Subtle changes of the N-terminal sequence, especially at Phe1, led to
the discovery of peptide antagonists ([Phe1 psi (CH2-NH)Gly2[-NC(1-13)-NH2 and
[Nphe1[-NC(1-13)-NH2). The first compound has been widely used to characterize NC
actions in the periphery and in the central nervous system. It has been shown to
act mainly as an antagonist outside the brain and as an agonist in the central
nervous system. [Nphe1[-NC(1-13)-NH2- on the contrary, acts as antagonist both in
the periphery and in the brain. These first peptide prototypes may soon be
followed by non-peptide compounds, some of which, are already described in
patient literature.
PMID- 10668184
TI - 5-Nitroimidazole derivatives as possible antibacterial and antifungal agents.
AB - Some novel 1-[2-[[5-(2-furanyl)-4-substituted 4H-1,2,4-triazol-3-yl[thio[ethyl[-2
methyl-5-nitro-1H-imidazoles (3), 1-[3-[[5-(2-furanyl/2-thienyl)-4-substituted 4H
1,2,4-triazol-3-yl[-thio]-2-hydroxypropyl[-2-methyl-5-nitro-1H- imidazoles (5)
and 1-[3-[(N,N-disubstituted thiocarbamoyl)-thio[-2-hydroxypropyl]-2-methyl-5
nitro-1H-imidazoles (7) were synthesized and evaluated for in vitro antibacterial
and antifungal activity. Some of 5 were found to be effective against bacteria
and fungi (minimum inhibitory concentration (MIC) 7.3-125 micrograms/ml), whereas
7 were found to be effective against fungi (MIC 3-25 micrograms/ml).
PMID- 10668185
TI - Bioavailability of dalarelin--a superactive GnRH analogue--in rats.
AB - 125I-marked dalarelin (a modified analogue of GnRH) or GnRH (gonadotropin
releasing hormone) were administered to the tested rats in single doses of 127
ng/kg by subcutaneous injections. Dalarelin and GnRH were absorbed from the
injected doses in 0.64 and 0.49%, respectively. Only one remarkable maximal
concentration of these hormones was noticed in rats' blood 30 min after the
administration. Dalarelin maximal concentration was 261.5 pg/cm3 and was 93.43%
higher than the maximal concentration of GnRH. Dalarelin bioavailability was
1651.89 pg/cm3, whereas GnRH bioavailability was 718 pg/cm3 h. The
bioavailability level of dalarelin was 230% compared with that for GnRH, which
was accepted as a pattern of bioavailability.
PMID- 10668186
TI - Anticonvulsant activity of analogues of acetazolamide.
AB - The anticonvulsant activity of 5-tertbutyloxycarbonylamido-1,3,4-thiadiazole-2
sulfonamide (B-H2ats) and 5-amino-1,3,4-thiadiazole-2-sulfonamide (Hats) was
compared in mice, to that of acetazolamide (H2acm). These compounds exhibit
potent anticonvulsant activity and low minimal motor impairment.
PMID- 10668187
TI - Synthesis and anticonvulsant activity of some (2/4-substituted)benzaldehyde (2
oxobenzothiazolin-3-yl)acetohydrazones.
AB - Fifteen new (2/4-substituted)benzaldehyde (2-oxobenzothiazolin-3
yl)acetohydrazones were synthesized and their structures were elucidated by NMR
and elemental analysis. Their anticonvulsant activity was tested by a
pentylenetetrazole induced seizure test. Compounds 4e and 4h were found to be the
most promising among the others.
PMID- 10668188
TI - Synthesis and antinociceptive activity of some 3-substituted benzothiazolone
derivatives.
AB - Thirteen 3-substituted benzothiazolone derivatives have been synthesized. Their
chemical structures have been elucidated by IR and NMR spectral data and by
elemental analyses. Among these compounds, 1-?3-[2(3H)-benzothiazolon-3
yl[propanoyl]morpholine (5b); 1-?3-[2(3H)-benzothiazolon-3-yl[propanoyl]-4
benzylpiperidine++ + (5c); 1-?3-[2(3H)-benzothiazolon-3-yl[-propanoyl]-4
phenylpiperazine (5d); 3-[3-(4-benzylpiperidine-1-yl)propyl]-2(3H)
benzothiazolone (5k); 3-[3-(4-benzylpiperazine-1-yl)propyl]-2(3H)-benzothiazolone
(5I); 3-[3-(4-phenylpiperazine-1-yl)propyl]-2(3H)-benzothiazolone (5m) have been
found to be significantly more active than the others.
PMID- 10668189
TI - Intermediate filament protein expression and sugar moieties in normal canine
placenta.
AB - In the female dog, the placenta is considered zonal, endotheliochorial and
labyrinthic. The distribution of the intermediate filaments as well as the
surface glycoproteins in the canine placenta are still unknown. The aim of the
present study was to provide this information for further understanding of
pathological conditions in the bitch. Samples were obtained from normal uterine
horns at the end of gestation. Tissues were routinely fixed and stained.
Monoclonal antibodies against cytokeratins, vimentin and desmin were used for
immunohistochemical staining. UEA-1, PNA, RCA-1, SBA, DBA, WGA and ConA were used
for the lectin histochemical staining. A computer morphometrical analysis was
made. Statistical analysis was then accomplished. The results showed the maximum
immunohistochemical percentage for vimentin in the supraglandular connective
tissue, for pancytokeratin in the spongy zone and for desmin in miometrium. SBA
showed the highest staining percentage in the gland cells of the spongy zone,
while ConA was the highest in the syncytiotrophoblastic cells and gland cells of
the deep glandular zone. The results obtained indicate that the lectin binding
pattern is partially different from other animal species. On the contrary, the
intermediate filament data coincide with similar observations from other mammals.
PMID- 10668190
TI - Effect of irradiation on autogenous bone transplantation in rat parietal bone.
AB - To determine the appropriate time for bone reconstruction after irradiation, the
healing process after autogenous iliac bone transplantation in the irradiated
parietal bone was examined by scanning electron microscopy and light microscopy.
Bone transplantation was carried out at the second and the fourth weeks after
Cobalt-sixty (60Co) irradiation with calculated dose and fractionation. Animals
without irradiation were used as control. The results show the appearance of
mesenchymal cells and blood vessels around the transplantation to be extremely
few one week after transplantation which was carried out at the second week after
irradiation. These inhibitions were still seen two weeks after transplantation.
Four weeks after transplantation, there were no differences in the bone formation
among the experimental groups. Bone formation in the transplantation at the
fourth week after irradiation was similar to that of the control group.
Microvascularization in the transplantation at the second week after irradiation
was inhibited one week after transplantation. The delay in bone healing was
responsible for the retardation of revascularization and caused microcirculatory
failures as well as the damage of osteogenic cells. It is quite clear that
damaged cells and tissues recovered by the elapse of time under the irradiation
procedure employed in this study and also that bone formation was carried out in
the physiological process. We think that bone transplantation after irradiation
should be done after recovery from the radiation damage to the periosteal cells
and the blood vessels.
PMID- 10668191
TI - Functional status of the immune system after chronic administration of 2'
deoxycoformycin in the BB rat.
AB - Insulin-dependent diabetes mellitus (IDDM) is caused by autoimmune destruction of
pancreatic beta cells with the primary mechanism being cell mediated. The BB rat
develops insulitis and IDDM with many features analogous to the disease in man.
In previous studies we reported that weekly administration of 2'-deoxycoformycin
(dCF) for four months reduces significantly the incidence of IDDM in the BB rat
by 70%, and that the animals remain free of diabetes for a minimum of two months
after drug withdrawal. Since the diabetes-prone BB rat is lymphopenic, with a
reduction of both CD4 and CD8 cells, the continuous failure of dCF treated
animals to develop diabetes may have been due to generalized immunosuppression.
To test this possibility, the ability of dCF treated diabetes-free BB rats to
mount an immune response after challenge with Ovalbumin was examined five months
after drug withdrawal. The results showed that the post-immunization levels of
total IgG and specific IgG in these animals did not differ from those observed in
non-dCF treated controls nor those of control diabetes-resistant non-lymphopenic
BB rats. Moreover, FACS analysis indicated no change in the percentages of total
numbers of CD4+ or CD8+ cells between the two groups of animals. Histological
assessment of the pancreata of the post-dCF treated animals showed varying
degrees of mononuclear cell infiltrates in the islets. These data demonstrate
that treatment by dCF is not permanent, and may require intermittent or
continuous administration to prevent development of diabetes. Further studies are
needed to determine the mechanism of action of dCF in this model of IDDM.
PMID- 10668192
TI - Studies on the breakdown of glycogen in the lysosomes: the effects of
hydrocortisone.
AB - The effects of hydrocortisone on newborn rat liver were studied by using
biochemical assays, electron microscopy and quantitative morphometry.
Hydrocortisone increased the number of lysosomes in the hepatocytes. Most of the
lysosomes represented glycogen-containing autophagic vacuoles. The glucocorticoid
also increased the activity of the liver glycogen-hydrolyzing acid glucosidase
and the breakdown of glycogen inside lysosomes. The activity of the liver acid
mannose 6-phosphatase was decreased. This may be related to the stimulation of
autophagic mechanisms in the newborn rat hepatocytes.
PMID- 10668193
TI - Does diabetic state affect co-localization of peptide YY and enteroglucagon in
colonic endocrine cells?
AB - BACKGROUND: Changes in the numbers of PYY- and enteroglucagon-immunoreactive
cells in colon of animal models of human diabetes have been reported. As these
peptides co-localize in the same cells it is possible that the observed changes
are a result of changes in co-localization. METHODS: Animal models of human type
1 and type 2 diabetes, namely the non-obese diabetic (NOD) mouse and the obese
(ob/ob) mouse, were studied. As controls for the NOD mice, BALB/cJ mice were used
and for ob/ob mice, homozygous lean (+/+) mice were used. Tissue samples from
colon were double-immunostained for PYY and enteroglucagon according to the
indirect immunofluorescence method. RESULTS: Co-localization of enteroglucagon
and PYY was found in colonic endocrine cells in all groups investigated. Compared
with controls, pre-diabetic NOD mice showed a decreased proportion of
enteroglucagon/PYY co-localization. There was no difference in diabetic NOD mice
or diabetic ob/ob mice when compared with controls. CONCLUSIONS: Whereas the
number of cells containing solely enteroglucagon and solely PYY increases in pre
diabetic NOD mice, production of enteroglucagon in PYY-immunoreactive cells
decreases. Although the numbers of PYY and enteroglucagon cells have been
reported to be changed in both diabetic NOD mice and in obese mice, the balance
between co-expressing and mono-expressing cells seems to be preserved.
PMID- 10668194
TI - Topological differences along mammalian motor nerve terminals for spontaneous and
alpha-bungarotoxin-induced sprouting.
AB - Spontaneous sproutings can be observed in end plates from normal adult vertebrate
muscles and motor end plates develop increased growth signs and sprouts when
target muscle cells become less active or paralysed. Nevertheless, very little is
known about where in the motor nerve terminal arborization spontaneous and
experimentally induced sprouts originate, their similarities and differences and
also about their final maturation or elimination. In this study we investigate
the topological properties of both spontaneous and alpha-bungarotoxin-induced
sprouts (during different periods of intoxication and after recovery) along the
motor nerve terminal branches of the Levator auris longus muscle of Swiss mice
(between 48-169 day old). Muscles were processed for immunocytochemistry to
simultaneously detect postsynaptic AChRs and axons. This procedure permits us to
make an accurate identification of the fine sprouts and a morphometric study of
the presynaptic branching pattern profile in control muscles, during the toxin
action and after recovery from paralysis. The results show that in normal
muscles, the initial and trunk segments (those between branch points) of the
terminal arborization sprouted proportionally more branches when taking their
relative lengths into account than the distal free-end segments. In contrast,
every micrometer of alpha-bungarotoxin-treated muscles throughout the full
terminal arborization have the same probability of generating a sprout. Moreover,
the toxin-induced sprouts can consolidate as new branches once recovered from the
paralysis without changing the total length of the nerve terminal arborization.
PMID- 10668195
TI - Apoptosis in gallbladder carcinomas and dysplasias, its relation to the
expression of caspases 3, 6 and 8 and apoptosis regulating proteins bcl-2, mcl-1
and bax.
AB - In this study we investigated apoptosis and the expression of caspases 3, 6 and 8
and bcl-2, mcl-1 and bax in 39 gallbladder carcinomas and 7 epithelial
dysplasias. The average apoptotic index was 0.68 +/- 0.91%. The extent of
apoptosis was higher in grade II-III than grade I tumours or epithelial
dysplasias (p = 0.003). Also, tumours invading beyond serosa or into other organs
(T3-T4) had a higher apoptotic index than other tumours (p = 0.05). Caspase 3
expression was found in 37 (95%) and caspase 6 and 8 expression each in 30 (77%)
carcinomas. Their expression associated with each other and tended to increase
along with the progression of the lesions. Bcl-2 expression was found in only 4
(10%) tumours. In contrast, mcl-1 positivity was found in 34 (87%) and bax
positivity in all cases. The results show that apoptosis is increased along with
progression of the neoplastic lesions of the gallbladder epithelium. Caspases 3,
6 and 8 are strongly expressed in gallbladder carcinomas suggesting that they
contribute to the increased apoptosis observed in them. Of the bcl-2 family
proteins, bcl-2 was expressed infrequently suggesting that it does not play any
significant role in apoptosis inhibition in gallbladder tumours.
PMID- 10668196
TI - Aging affects different human muscles in various ways. An image analysis of the
histomorphometric characteristics of fiber types in human masseter and vastus
lateralis muscles from young adults and the very old.
AB - This study is an attempt to objectively evaluate age-related changes in human
muscles by use of histomorphometric methods. Aging in humans induces dramatic
transformations in the skeletal muscles but little is known as to whether or not
the aging processes per se may affect all muscles equally. In this study aging of
two human muscles with different functions, origin and nerve supply is compared.
Sections were cut from masseter and vastus lateralis muscles obtained from young
adults aged 18-24 years and from the very old aged 90-102 years. Muscle fiber
types were classified with the traditional myofibrillar ATPase staining. Various
histomorphometric parameters of the different fiber types in human masseter and
vastus lateralis muscle sections were obtained by image analyses to evaluate the
age-related changes in the muscle fibers. The following variables were
calculated: the number of each fiber type per photographed area; the area of each
fiber and two indicators for the shape of the muscle fibers. In the aging muscles
there was no relative preferential loss of a fiber type. High numbers of
intermediate ATPase-stained fibers (IM fibers) were found in some old vastus
muscles but were only sporadic in young vastus muscles. However, there was no
change in the percentage distribution of intermediate ATPase-stained fibers when
young and very old human masseter muscles were compared. Incubation of the
sections with antimyosin antibodies showed that the IM fibers in old masseter and
old vastus contained different myosin heavy chains. Thus ATPase activity and anti
myosin staining displayed a somewhat different pattern of fiber type
distribution. The main changes in the shape and area indicated that type I fibers
in the masseter became more circular while in the vastus they decreased
significantly in size. The type II fibers in the vastus became very small and
deviated significantly from circularity whereas the type II fibers in the
masseter only exhibited a decrease in the size of the fibers. Histomorphometric
measurements show that aging affects different human muscles in various ways.
PMID- 10668197
TI - Effect of hypertension on the angiotensin II fibres arriving at the posterior
lobe of the hypophysis of the rat. An immunohistochemical study.
AB - We studied immunohistochemically the posterior lobe of the hypophysis (PL) of 15
week-old spontaneously hypertensive rats (SHR) and of matched normotensive Wistar
Kyoto rats (WKY), by using our own polyclonal antibody raised in mice against
Angiotensin II (mouse-antiangiotensin II, MAAII). The blood pressure, water
intake and volume of the PL were also recorded. The SHR rats were hypertensive,
drank more water and showed a clear hypertrophy of their hypophysial PL. Also the
PL of the SHR animals showed an increase in the immunoreactivity to the anti
angiotensin II antibody in the fibres arriving at the PL, with respect to the PL
of WKY rats. This increase is compatible with the hyperactivity of the brain RAS,
depletion of vasopressin content in the PL and increase in plasmatic levels of
vasopressin described in SHR rats with respect to normotensive animals, as
angiotensin II could locally stimulate vasopressin release to plasma from the
neurohypophysis.
PMID- 10668198
TI - Human papillomaviruses and DNA ploidy in anal condylomata acuminata.
AB - Previous studies have emphasized the usefulness of DNA ploidy measurement and
Human Papillomavirus (HPV) detection as prognostic markers in low grade cervical
lesions. We addressed the eventual relationship between HPV type, DNA profile,
and p53 tumor suppressor protein expression in anal condylomata acuminata to
eventually determine parameters which may be considered as predictive risk
factors for the development of cancer. DNA ploidy was assessed by image cytometry
after Feulgen staining of contiguous serial sections of 45 anal condylomata
acuminata without atypia containing HPV detected by in situ hybridization and
Polymerase Chain Reaction (PCR). p53 expression was detected by
immunohistochemistry. DNA aneuploidy was found in 53.3% of these lesions, 48.9%
containing non oncogenic HPV types 6 and/or 11 and 4.4% harbouring HPV types 11
and 18. The DNA diploid lesions were all associated with non oncogenic HPV types
6 and/or 11 and one case also contained HPV type 33. There was no significant
correlation between the detection of DNA aneuploidy and the presence of immuno
detected p53. DNA aneuploidy was not related to the presence of oncogenic HPV in
anal condylomata acuminata. The DNA aneuploid profile frequently observed,
especially in lesions associated with non oncogenic HPV types, is not yet well
explained and cannot be considered as a prognostic factor. In contrast, a more
intensive clinical follow-up should be proposed in patients with oncogenic HPV
associated to DNA aneuploidy.
PMID- 10668199
TI - Expression of galectin-1 and -3 and of accessible binding sites during murine
hair cycle.
AB - Although protein-carbohydrate interactions are supposed to play key roles in cell
adhesion, signalling and growth control. Their exact role in skin physiology has
only recently been investigated. The endogenous lectins galectin-1 and galectin-3
have been identified in skin including hair follicles. Here, we analyzed the
expression and distribution of these galectins and their binding sites in C57BL/6
mice during hair cycle. The expression of galectin-1 and galectin-3 binding sites
was found to be predominantly hair cycle-dependent showing some overlapping to
the expression of galectin-1 and -3. The outer root sheath (ORS) expressed
galectin-1 binding sites during anagen IV to VI and in early catagen, whereas
galectin-1 was expressed from early anagen to late catagen. The ORS expressed
galectin-3 binding sites during catagen transition corresponding to a galectin-3
expression during anagen V and catagen. The innermost layer of the ORS expressed
galectin-3 binding sites during anagen VI until catagen VIII, but galectin-3
during anagen III to IV and catagen. The inner root sheath (IRS) expressed
galectin-3 binding sites only in anagen IV but missed expression of any of the
two galectins. The matrix cells expressed galectin-3 binding sites in catagen II
III as well as galectin-3 during anagen V to catagen IV. The present study
provides the first evidence for a cycle-related expression of both galectin-1 and
-3 and their binding sites during murine hair cycle.
PMID- 10668200
TI - Elastin variations implicating in vascular smooth muscle cells phenotype in human
tortuous arteries.
AB - The aim of the present work was to study the morphological implications between
the elastin and the phenotypic expression of the vascular smooth muscle cells.
For this purpose, sixty human tortuous arteries from different territories have
been studied. We have measured the morphometric indexes Intimal Thickening Index
and Elastolyse Index and they have been quantified with computer system analysis,
image-colour corresponding to the orcein and Verhoeff reactions for detecting
elastin and the alpha-actin in the smooth muscle cells. We compared both
territorial arteries from the cranial and from abdominal origin. The elastin
concentration was similar in both territories, but not its morphology according
to its spatial distribution. We have observed a relationship between the elastin
structural organisation from the media of arteries and of the internal elastic
lamina in these territories and the variation of reactivity to the smooth muscle
alpha-actin as a marker of the phenotypic state. Our results confirm the
hypothesis that elastin, besides intervening in the architecture of the arterial
wall, is a factor implicated in the phenotypic variability of the smooth muscle
cells and in the development and evolution of the intimal thickenings in human
atherosclerosis.
PMID- 10668201
TI - The molecular determinants of the efficiency of green fluorescent protein
mutants.
AB - The Green Fluorescent Protein (GFP) is a spontaneously fluorescent polypeptide of
27 kD from the jellyfish Aequorea victoria that absorbs UV-blue light and emits
in the green region of the spectrum. GFP has been successfully expressed both in
bacteria and in eukaryotic cells and is widely used to monitor the localization
of tagged proteins in living cells. Since wtGFP performs inefficiently in
different cellular contexts, efforts have been devoted to the improvement of GFP
expression levels and/or fluorescence. We will here review the basic
characteristics of wt and mutated GFP, in particular their protein expression vs
fluorescent properties. Emphasis will be given to unexpected consequences of
mutations of the GFP gene, i.e. on transcription and translation rates and on
protein folding in different cell types, and to how these critically reflect on
the use of GFP in different cellular environments.
PMID- 10668202
TI - The yin-yang of PR-domain family genes in tumorigenesis.
AB - Cancer is essentially caused by alterations in normal cellular genes. Multiple
gene changes involving at least two types of cancer genes, protooncogenes and
tumor suppressor genes, are required for the clonal expansion of a malignant
cell. This discussion focuses on the recently recognized role of a small but
expanding family of PR-domain genes in tumorigenesis. The protein products of
these genes are involved in human cancers in an unusual yin-yang fashion. Two
products are normally produced from a PR-domain family member which differ by the
presence or absence of the PR domain; the PR-plus product is disrupted or
underexpressed whereas the PR-minus product is present or overexpressed in cancer
cells. This imbalance in the amount of the two products, a result of either
genetic or epigenetic events, appears to be an important cause of malignancy.
PMID- 10668203
TI - The role of the epidermal growth factor-like protein dlk in cell differentiation.
AB - This review focuses on the current knowledge about the function of the EGF-like
homeotic protein dlk. dlk is a transmembrane protein that possesses six Epidermal
Growth Factor-like sequences at the extracellular domain, a single transmembrane
domain and a short intracellular tail. Because of its overall structure and amino
acid homology, dlk belongs to the EGF-like homeotic protein family. This family
includes proteins such as the Notch receptor and its homologues, as well as Notch
ligands, such as Delta, Serrate, and their mammalian homologues Dll1, Dll2 and
Dll3 and Jagged 1 and Jagged 2. (For a recent review see Fleming, 1998). dlk is
highly expressed by preadipose cell lines, and neuroendocrine tumors, such as
pheochromocytomas and neuroblastomas. dlk has been involved in several
differentiation processes, such as adipogenesis, hematopoiesis and B cell
lymphopoiesis, and neuroendocrine differentiation, including the differentiation
of pancreas and the adrenal gland. The extracellular region of dlk can be
released by action of an unknown protease and this soluble dlk variant
accumulates in the amniotic fluid and is able to inhibit adipocyte
differentiation in vitro. Recent evidence indicates, however, that membrane
associated dlk variants play a positive role in the differentiation process.
These findings suggest that dlk plays an important role in differentiation and
tumorigenesis of several cellular types.
PMID- 10668204
TI - The female prostate and prostate-specific antigen. Immunohistochemical
localization, implications of this prostate marker in women and reasons for using
the term "prostate" in the human female.
AB - Prostate-specific antigen (PSA) is currently the most frequently used marker for
the identification of normal and pathologically altered prostatic tissue in the
male and female. Immunohistochemically PSA is expressed in the highly specialized
apically-superficial layer of female and male secretory cells of the prostate
gland, and as well as in uroepithelial cells at other sites of the urogenital
tract of both sexes. Unique active moieties of cells of the female and the male
prostate gland and in other parts of the urogenital tract are indicative of
secretory and protective function of specialized prostatic and uroepithelial
cells with strong immunological properties given by the presence of PSA. In
clinical practice, PSA is a valuable marker for the diagnosis and monitoring of
diseases of the male and the female prostate, especially carcinoma. In the
female, similarly as in the male, the prostate (Skene's gland) is the principal
source of PSA. The value of PSA in women increases in the pathological female
prostate, e.g., carcinoma. Nevertheless, the total amount of PSA in the female is
the sum of normal or pathological female prostate and non-prostatic female
tissues production, e.g., of diseased female breast tissue. The expression of an
antigen specific for the male prostate, i.e., PSA in female Skene's glands and
ducts, and structural and functional parameters and diseases similar to that of
the male prostate, have provided convincing evidence of the existence of a
prostate in women and definitive preference of the term "prostate" over that of
Skene's glands and ducts. The use of the term Skene's glands incorrectly implies
that some other structure rather than prostate is involved, promoting the
vestigial position of this female organ.
PMID- 10668205
TI - The involvement of Helix pomatia lectin (HPA) binding N-acetylgalactosamine
glycans in cancer progression.
AB - The lectin from Helix pomatia, the Roman snail (HPA), recognises terminal alpha N
acetylgalactosamine residues. A large number of lectin histochemical studies have
demonstrated that expression of HPA-binding glycoproteins by cancer cells to be a
marker of metastatic competence and poor prognosis in a range of common human
adenocarcinomas, including those of breast, stomach, ovary, oesophagus,
colorectum, thyroid and prostate. Around 80% of metastases arising from primary
breast cancer are predictably HPA positive, but, intriguingly, around 20% do not
express HPA binding glycoproteins reflecting the complexity of metastatic
mechanisms and the further disruptions in cellular glycosylation that attend
tumour progression. HPA binding is not an independent prognostic factor, but is
strongly associated with the presence of metastases in local lymph nodes. It does
appear to be independent of other clinical features of prognostic importance such
as tumour size, histological grade, S-phase fraction, ploidy, and there is little
convincing evidence of any association with oncogene expression or hormone
receptor positivity. The precise nature of the metastasis-associated HPA binding
partner(s) is a question of some interest, but thus far remains unclear. HPA will
recognise, for example, the Tn epitope and blood group A antigen, but its
prognostic significance appears to be through recognition of a much broader and
heterogeneous array of N-galactosaminylated glycoproteins. Their synthesis
appears to be mediated through alteration in expression or activity of one or
more of the enzymes of glycosylation. The most likely putative roles of HPA
binding ligands in the metastatic cascade may be enhancement of invasive
capacity, or interaction with an as yet unidentified lectin-like receptor
facilitating adhesion processes. The prognostic information provided by HPA
lectin histochemistry may be used clinically to inform the physician and aid
treatment decisions; far more interesting is the challenge of further
understanding the precise nature of the HPA-binding ligands, and defining their
role in the complex mechanisms of metastasis.
PMID- 10668206
TI - Gene expression and cell turnover in human renal dysplasia.
AB - Kidney malformations are common causes of chronic renal failure in children.
Dysplastic kidneys represent a unique model of perturbed epithelial-mesenchymal
interaction which leads to the formation of malformed branching tubules
surrounded by undifferentiated and metaplastic mesenchymal cells. We have found
that human dysplastic epithelia express PAX2 (a transcription factor), BCL2 (a
survival factor) and galectin-3 (a cell adhesion/signaling molecule). These genes
are implicated in oncogenesis and their persistent expression may drive
proliferation of dysplastic cysts, hence explaining the massive growth of some
multicystic dysplastic kidneys. We have also detected prominent apoptosis in
undifferentiated tissues around dysplastic epithelia, and this may provide a
potential mechanism for the well-documented regression of dysplastic kidneys.
Hence, although these kidneys may not have any excretory function, it is
incorrect to consider them as 'end stage organs' because they are highly active
in terms of cell turnover and gene expression; furthermore, these processes can
be correlated with patterns of tissue growth and involution. Further elucidation
of 'molecular lesions' in renal malformations may lead to novel therapies to
enhance the differentiation of progenitor cells.
PMID- 10668207
TI - The role of activated cytotoxic T cells in inflammatory bowel disease.
AB - The role of cell-mediated cytotoxicity in the pathogenesis of ulcerative colitis
and Crohn's disease has been controversial since reports indicating either a
decreased, or an increased, activity of cytotoxic T cells in active stages of
inflammatory bowel disease exist. Some of these discrepancies may be attributed
to the fact that so far mostly peripheral blood lymphocytes rather than
intestinal T cells have been examined. To overcome some of these limitations we
performed in situ hybridizations for the detection of perforin and granzyme A
mRNA expressing cells, i.e. of cytotoxic cells activated in situ, in the affected
intestinal mucosa. These studies revealed increased frequencies of activated,
cytotoxic T cells in active stages of ulcerative colitis and Crohn's disease.
Interestingly, activated perforin mRNA expressing T cells are present both in the
CD4 and in the CD8 T cell subsets. In the latter T cell subset up to 60% of the
mucosal T cells isolated from the affected sites express perforin mRNA at
detectable levels. The elevated frequency of activated cytotoxic cells and their
histological distribution also in close proximity to the epithelial cells may
thus indicate an important role for cytotoxic cells in the pathogenesis of
inflammatory bowel disease since activated cytotoxic T cells may further
exacerbate the inflammatory process through the production of pro-inflammatory
cytokines such as interferon-gamma or tumor necrosis factor-alpha, but also
through the release of pro-inflammatory cytokines and chemokines upon lysis of
epithelial cells and the increased influx of luminal antigens at the site of
epithelial erosions.
PMID- 10668208
TI - The visualization of oxidant stress in tissues and isolated cells.
AB - Many studies have implicated the role of oxidant stress in a wide range of human
diseases and have led to the rapid expansion of research in this area. With many
experimental approaches a direct detection of the production of reactive oxygen
species (ROS) and free radicals is not possible. Free radicals are very reactive,
short-lived and react in a non-specific way, so that ongoing oxidative damage is
generally analyzed by measurement of secondary products e.g. H2O2, "oxidized"
proteins, peroxidized lipids and their break-down products, "oxidized" DNA or by
fluorographic analysis in combination with fluorescent dyes e.g.
dichlorofluorescin (DCFH). The histochemical visualization of selected molecular
markers for oxidative phenomena can often provide valuable information concerning
the distribution of oxidative processes in vivo. A number of biochemical methods
are available for the monitoring of almost all oxidant stress-related processes,
although their applicability in vivo is limited. This review summarizes the
biochemical methods currently available for histochemical detection and indirect
visualization of an excess of free radicals and ROS. The cited methods are
discussed and the results obtained from their application are critically
evaluated.
PMID- 10668209
TI - Organ specificity of the structural organization and fine distribution of
lymphatic capillary networks: histochemical study.
AB - Histochemical studies of the microcirculatory system were reviewed with regard to
the organ specificity of the structural organization and fine distribution of the
lymphatic capillary network. The lymphatics and blood vessels are characterized
by an enzyme-histochemical method using 5'-nucleotidase (5'-Nase), alkaline
phosphatase (ALPase) and/or diaminopeptidase (DAPase) staining in addition to an
immunohistochemical method. The 5'-Nase-positive lymphatic vessels can be
distinguished histochemically from arterial and venous vessels based on ALPase
and DAPase activity, respectively. The specificity and localization of the enzyme
reactions were confirmed by comparative histochemical studies of the same
specimen with light microscopy and scanning or transmission electron microscopy.
These histochemical methods are discussed in relation to their ability to
demonstrate the organ specificity of vascular networks under normal and
pathological conditions.
PMID- 10668210
TI - Current understanding of macrophage type 1 cytokine responses during
intracellular infections.
AB - Macrophages are important effector cells in cell-mediated immunity against
intracellular infection. Among cytokines that macrophages are able to release are
IL-12 and TNF alpha. IL-12 is a critical linker between the innate and adaptive
cell-mediated immunity, capable of Th1 differentiation and IFN gamma release by T
and NK cells. IFN gamma is critically required for the activation of macrophage
bactericidal activities. Recently emerging evidence suggests that macrophages are
able to release not only IL-12 and TNF alpha but also IFN gamma. However, the
mechanisms that control the release of each of these type 1 cytokines in
macrophages appear different. While macrophages release TNF alpha in an
indiscriminate and IL-12-independent way, the release of IL-12, particularly
bioactive IL-12 p70, and IFN gamma is under tight control. We are just beginning
to understand what controls the release of IL-12 p70, a question of fundamental
importance to understanding the mechanisms underlying the initiation of cell
mediated immunity. Our recent findings have shed more insights into the
regulatory mechanisms of macrophage IFN gamma responses. It has become evident
that IL-12 is required not only for Th1 differentiation but also for IFN gamma
responses by both T cells and macrophages during intracellular infection. In this
overview, we have discussed about the current understanding of the regulation of
macrophage type 1 cytokine responses during intracellular infection, based upon
the recent findings from us and others.
PMID- 10668211
TI - Histopathology of the male reproductive system induced by the fungicide benomyl.
AB - Benomyl is an effective fungicide that has been in use for many years. This
chemical and its primary metabolite, carbendazim, are microtubule poisons that
are relatively nontoxic to all mammalian organs, except for the male reproductive
system. Its primary effects, at moderate to low dosages, are on the testis, where
it causes sloughing of germ cells in a stage-dependent manner. Sloughing is
caused by the effects of the chemical on microtubules and intermediate filaments
of the Sertoli cell. These effects spread to dividing germ cells and also lead to
abnormal development of the head of elongating spermatids. At higher dosages, it
causes occlusion of the efferent ducts, blocking passage of sperm from the rete
testis to epididymis. The mechanism of occlusion appears to be related to fluid
reabsorption, sperm stasis, followed by leukocyte chemotaxis, sperm granulomas,
fibrosis and often the formation of abnormal microcanals. The occlusion results
in a rapid swelling of the testis and ultimately seminiferous tubular atrophy and
infertility. In conclusion, studies that reveal long term testicular atrophy
following chronic or subchronic exposure to a toxicant should be re-examined for
histopathological lesions in the efferent ductules and head of the epididymis.
Lesions in the male track that cause blockage may induce permanent testicular
damage and a decrease in sperm production.
PMID- 10668212
TI - Matrix metalloproteinases in squamous cell carcinoma.
AB - Controlled degradation of extracellular matrix (ECM) is essential in many
physiological situations including developmental tissue remodeling, angiogenesis,
tissue repair, and normal turnover of ECM. In addition, degradation of matrix
components is an important feature of tumor growth, invasion, metastasis, and
tumor-induced angiogenesis. Matrix metallo-proteinases (MMPs) are a family of
zinc-dependent neutral endopeptidases, which are collectively capable of
degrading essentially all ECM components. MMPs apparently play an important role
in all the above mentioned aspects of tumor development. In addition, there is
recent evidence that MMP activity is required for tumor cell survival. At
present, several MMP inhibitors are in clinical trials of malignant tumors of
different histogenetic origin. In this review we discuss the current view on the
role of MMPs and their inhibitors in development and invasion of squamous cell
carcinomas, as a basis for prognostication and therapeutic intervention in these
tumors.
PMID- 10668213
TI - Splicing and the single cell.
AB - The selection of alternative splice sites is an important component of cell
specific gene regulation in eukaryotic cells. Use of splice sites can be
positively and negatively regulated, and often physiologically appropriate splice
site choice is achieved by a balance of the two. RNA elements controlling splice
site choice are found in both exons and introns, and these determine management
by the cellular splicing machinery. However, the molecular basis of how the
splicing machinery responds to these signals in different cells is somewhat of a
paradox. Thus far the identified proteins which bind to tissue/cell-specific
regulatory elements in mammals are expressed in many different tissues, and not
just in the regulating tissue. Potential tissue-specific splicing regulators have
been identified by non-biochemical means. However, alternative splicing choices
are likely to be affected by subtle differences in the splicing machinery in
different cells. In this review I suggest that one important factor is the ratio
of proteins in different nuclear compartments, which might be established in a
cell type specific fashion.
PMID- 10668214
TI - Catenins and their associated proteins in colorectal cancer.
AB - Colorectal cancer is the second most common cause of cancer mortality in the
western world. Colorectal cancer has been well studied, and the genetic steps
involved in the adenoma to carcinoma sequence have been well elucidated. The
first genetic alteration, found in 85% of adenomas, are mutations in the
adenomatous polyposis coli (APC) gene. However, the consequences of this and the
exact function of APC in the colon is not fully understood. It has been suggested
that APC could function through its regulation of beta-catenin, an ubiquitous
cytoskeletal protein with multiple binding specificities resulting in diverse
functions including cell growth, adhesion, and migration. Any change in these
associations may play a role in colorectal cancer development and progression.
PMID- 10668215
TI - Electron microscopic observation of intracellular expression of mRNA and its
protein product: technical review on ultrastructural in situ hybridization and
its combination with immunohistochemistry.
AB - In situ hybridization (ISH) at the electron microscopic (EM) level is essential
for elucidating the intracellular distribution and role of mRNA in protein
synthesis. Three different approaches have been applied by the investigators in
this EM-ISH study: preembedding method; non-embedding method using ultrathin
frozen sections; and postembedding method. In order to obtain satisfactory
morphological preservation and retain the messages, we routinely utilized 6
microns-thick frozen sections fixed in 4% paraformaldehyde for the preembedding
method and tissues embedded in LR White resin for the postembedding method. The
hybridization signal intensity by the postembedding method was lower, and non
specific signals were relatively frequent, in comparison with the preembedding
method. The preembedding method thus appears to be easier and better than the
postembedding method from the viewpoint of applicability and preservation of
mRNA, although quantitative analysis of the expression of mRNA is rather
difficult in the preembedding method. EM-ISH is considered to be an important
tool for clarifying the intracellular localization of mRNA and the exact site of
specific hormone synthesis on the rough endoplasmic reticulum. The simultaneous
visualization of mRNA and encoded protein in the same cells using preembedding EM
ISH and subsequent postembedding immunoreaction with protein A colloidal gold
complex is also described. This ultrastructural double-staining method for mRNA
and encoded protein can be expected to provide an important clue for elucidating
the intracellular correlation of mRNA translation and secretion of translated
protein.
PMID- 10668216
TI - Role of myofibroblasts during normal tissue repair and excessive scarring:
interest of their assessment in nephropathies.
AB - Following injury, tissue repair process takes place involving inflammation,
granulation tissue formation and scar constitution. Granulation tissue develops
from the connective tissue surrounding the damaged area and contains vessels,
inflammatory cells, fibroblasts and myofibroblasts. Myofibroblasts play an
important role in many tissue injuries and fibrocontractive diseases. The process
of normal wound repair after tissue injury follows a closely regulated sequence
including the activation and the proliferation of fibroblastic cells. In
pathological situations, the normal resolution stages are abrogated and the
proliferation of myofibroblasts continues, inducing excessive accumulation of
extracellular matrix. The differentiation of fibroblastic cells into
myofibroblasts is an early event in the development of tissue fibrosis.
Myofibroblastic cells express smooth muscle cytoskeletal markers (alpha-smooth
muscle actin in particular) and participate actively in the production of
extracellular matrix. The evaluation of myofibroblast differentiation in renal
biopsies would be useful for histopathologists to appreciate the intensity of
tissue injury and particularly to predict the long term outcome of some
nephropathies. Immunohistochemical studies for alpha-smooth muscle actin should
be made systematically in renal tissue biopsies. Myofibroblastic differentiation
appears to play a significant role in the progression of renal failure and seems
to be a useful marker of progressive disease.
PMID- 10668217
TI - Apoptosis in cancer: therapeutic implications.
AB - This review outlines the principal limitations of the mechanisms of active cell
death (ACD, apoptosis) as the basis of tumorigenesis and the rationale of almost
all therapies of malignancy. The concentration of cancer therapy in the direction
of ACD induction is presented as both the result of progressive understanding of
the mechanisms of apoptosis and that of the favourable tumor environment for ACD
signal transmission. The latter property induces the by-stander killing of cancer
cells, a fundamental mechanism because efficiency of all known methods of cancer
treatment is far below 100%. Finally, recent results and hypotheses regarding
cancer gene therapy based on final inductors of apoptosis and endogeneous ACD
inhibitors in tumors are evaluated.
PMID- 10668218
TI - A nuclear function for the tumor suppressor BRCA1.
AB - The breast and ovarian cancer susceptibility gene BRCA1 has been recently cloned
and revealed an open reading frame of 1863 amino acids, but a lack of significant
homology to any known protein in the database has led to few clues about its
functions. One of the first steps to investigate the function of BRCA1 was to
define its subcellular localization. Several reports have led to contradictory
findings that include: nuclear localization in normal cells and cytoplasmic in
breast and ovarian cancer cells; nuclear in both normal and cancer cells;
cytoplasmic and secreted to the extracellular space; present in tube-like
invaginations of the nucleus; and colocalizing with the centrosome. As is
apparent, the subcellular localization has been the most controversial aspect of
BRCA1 biology and is a key point to uncover its functions. In this paper we
review the published data on subcellular localization of BRCA1 with special
emphasis on the antibodies and techniques used. We conclude that there is now
overwhelming evidence to support a nuclear localization for BRCA1, both in normal
and cancer cells. In addition, several BRCA1-interacting proteins have been
isolated and they are preferentially located in the nucleus. Evidence supporting
a physiological function for BRCA1 during DNA repair and transcriptional
activation is also discussed.
PMID- 10668219
TI - Genomic imprinting and Beckwith-Wiedemann syndrome.
AB - Genomic imprinting is the parental-allele-specific expression of genes. Beckwith
Wiedemann syndrome (BWS), a congenital overgrowth syndrome with increased risk of
childhood tumors, is one of the well-known diseases caused by imprinted genes.
The imprinted genes causing BWS are discussed in this review.
PMID- 10668220
TI - Pathological changes of human unmyelinated nerve fibers: a review.
AB - In the cutaneous nerves, unmyelinated nerve fibers outnumber the myelinated ones
but are scarcely analyzed, especially at autopsy. This indifference toward the
pathology of unmyelinated nerve fibers may be due to the necessity of electron
microscopic analyses and, more importantly, the obscurity of pathological
alteration of unmyelinated nerve fibers in aging as well as in peripheral nerve
disorders. The aim of this article is to review (1) the normal appearance
including postmortem changes, (2) the age-related changes, and (3) the
pathological alteration in various neuropathic and non-neuropathic conditions, of
unmyelinated nerve fibers in the sural nerve. For the complete analyses of sural
nerve, qualitative and quantitative estimation of unmyelinated nerve fibers in
all specimens should be recommended and it sometimes has an important diagnostic
value.
PMID- 10668222
TI - [IX Teaching Workshop on Family and Community Medicine. XIX National Congress of
Family and Community Medicine. Abstracts].
PMID- 10668221
TI - Regulation of VEGF in the reproductive tract by sex-steroid hormones.
AB - Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. In
adults, angiogenesis is an infrequent event in the normal tissue except in the
female reproductive tract where angiogenesis occurs frequently during the
cyclical repair and regeneration of the endometrium as well as in the ovary.
Little is known about angiogenesis in the male reproductive tract. The role of
VEGF in controlling reproductive tract physiology and the role of hormones in
regulating this key regulator of angiogenesis is not well understood. Since
reproductive tract physiology is largely under sex-steroid regulation, we have
reviewed some recent studies describing the role of sex-steroid hormones in
regulating VEGF. We have also included studies on the role of sex-steroids in
regulating VEGF and angiogenesis in endometrial, breast and prostate pathologies.
We have provided an extensive review of the classical VEGF and VEGF receptors
with examples drawn from numerous studies in the literature using diverse
biological systems to encourage similar studies in the area of reproductive tract
physiology. It is speculated that such studies will provide insights into
understanding the role of VEGF in reproductive tract development, causes of
infertility, and cancer. Such knowledge would allow us to target VEGF for
improving human reproductive tract abnormalities, for enhancing implantation and
fertility, and for designing drugs for treatment of endocrine dependent cancers.
PMID- 10668223
TI - [National Days of Laboratory Medicine of Russia, Moscow, October 12-14, 1999.
Workshop: clinical laboratory at the brink of the XXI century: synthesis of
traditions and novel trends (analysis, diagnosis, technology, and economics).
Abstracts].
PMID- 10668224
TI - Detection of the viable myocardium. A perfusion scintigraphic study, before and
after coronary bypass surgery in myocardial infarction patients.
AB - OBJECTIVE: To compare single-photon-emission computed tomography (SPECT) imaging
scans using 201Tl and 99mTc-MIBI in detection of viable myocardium, in regions
compromised by infarction. METHODS: Thirty-two (59.3 +/- 9.8 years old and 87%
male) myocardial infarction patients were studied. All had Q waves on the ECG and
left ventricle ejection fraction of < 50%. They underwent coronary and left
ventricle angiographies and SPECT before (including 201Tl reinjection) and after
coronary artery bypass surgery (CABG). Improvement in perfusion observed after
surgery was considered the gold standard for myocardial viability. RESULTS: Among
102 studied regions of the heart, there were 40 (39.2%) areas of transient
perfusion defects in the conventional protocol with 201Tl and 52 (51.0%) after
reinjection. Therefore, 12/62 (19.4%) more viable regions were identified by
reinjection. Using 99mTc-MIBI, only 14 (13.7%) regions with transient defects
were identified, all of which were seen also in 201Tl protocols. After surgery,
49 of a total of 93 regions analyzed (52.7%) were viable. Sensitivity,
specificity, accuracy, positive and negative prediction values were,
respectively, 201Tl SPECT scans--65.3%, 90.9%, 77.4%, 88.9% and 70.2%,
reinjection protocol with 201Tl scans--81.5%, 81.8%, 81.7%, 83.3% and 80.0%,
99mTc-MIBI SPECT scans--20.4%, 90.9%, 53.8%, 71.4% and 50.6%. Logistic regression
demonstrated that the reinjection protocol with 201Tl was the best predictor of
viability (P < 0.001). CONCLUSION: Our data suggest the election of 201Tl for
viability studies, especially when using the reinjection protocol.
PMID- 10668225
TI - Brazilian multicenter study on efficacy and tolerability of trandolapril in mild
to-moderate essential arterial hypertension. EMBATHE substudy with ambulatory
blood pressure monitoring.
AB - OBJECTIVE: A double-blind, placebo-controlled multicenter study involving 34
centers from different Brazilian regions was performed to evaluate the
antihypertensive efficacy and tolerability of trandolapril, an angiotensin I
converting enzyme inhibitor, in the treatment of mild-to-moderate systemic
arterial hypertension. METHODS: Of 262 patients enrolled in this study, 127 were
treated with trandolapril 2 mg/day for 8 consecutive weeks, and the remaining 135
patients received placebo for the same period of time. Reduction in blood
pressure (BP) and the occurrence of adverse events during this period were
evaluated in both groups. RESULTS: Significantly reductions in both systolic and
diastolic pressures were observed in patients treated with trandolapril when
compared with those on placebo. Antihypertensive efficacy was achieved in 57.5%
of the patients on trandolapril and in 42% of these normal values of BP were
obtained. The efficacy of trandolapril was similar in all centers, regardless of
the area of the country. In a subset of 30 patients who underwent ABPM,
responders showed a significant hypotensive effect to trandolapril throughout the
24 hour day. The adverse event profile was similar in both trandolapril and
placebo groups. CONCLUSION: Our results demonstrate, for the first time in a
large group of hypertensive patients from different regions in Brazil, good
efficacy and tolerability of trando-lapril during treatment of mild-to-moderate
essential systemic hypertension.
PMID- 10668226
TI - Dynamic three-dimensional reconstruction of the heart by transesophageal
echocardiography.
AB - OBJECTIVE: To evaluate echocardiography accuracy in performing and obtaining
images for dynamical three-dimensional (3D) reconstruction. METHODS: Three
dimensional (3D) image reconstruction was obtained in 20 consecutive patients who
underwent transesophageal echocardiography. A multiplanar 5 MHz transducer was
used for 3D reconstruction. RESULTS: Twenty patients were studied consecutively.
The following cardiac diseases were present: valvar prostheses--6 (2 mitral, 2
aortic and 2 mitral and aortic); mitral valve prolapse--3; mitral and aortic
disease--2; aortic valve disease--5; congenital heart disease--3 (2 atrial septal
defect--ASD- and 1 transposition of the great arteries-TGA); arteriovenous
fistula--1. In 7 patients, color Doppler was also obtained and used for 3D flow
reconstruction. Twenty five cardiac structures were acquired and 60
reconstructions generated (28 of mitral valves, 14 of aortic valves, 4 of mitral
prostheses, 7 of aortic prostheses and 7 of the ASD). Fifty five of 60 (91.6%)
reconstructions were considered of good quality by 2 independent observers. The
11 reconstructed mitral valves/prostheses and the 2 reconstructed ASDs provided
more anatomical information than two dimensional echocardiography (2DE) alone.
CONCLUSION: 3D echocardiography using a transesophageal transducer is a feasible
technique, which improves detection of anatomical details of cardiac structures,
particularly of the mitral valve and atrial septum.
PMID- 10668227
TI - Risk factors for atherosclerosis in students of a private university in Sao Paulo
Brazil.
AB - OBJECTIVE: To characterize the risk profile for atherosclerosis (AS) in
adolescents and young adults of a private university in Sao Paulo. METHODS:
Clinical, nutritional, and laboratory parameters were evaluated in 209 students
of both genders aged 17 to 25 years. In addition to determination of the lipid
profile, the association of its abnormal values with other risk factors for AS
was also investigated. RESULTS: Increased levels of total cholesterol, LDL-C and
triglycerides (TG) were observed in 9.1%, 7.6% and 16.3% of the students,
respectively, and decreased levels of HDL-C in 8.6% of them. Prevalence of the
remaining risk factors analyzed was elevated: sedentary life style (78.9%); high
intake of total fat (77.5%); high cholesterol intake (35.9%); smoking,
hypertension (15.8%) and obesity (7.2%). There was an association between
elevated LDL-C and TG levels and sedentary life style and body mass index.
CONCLUSION: The high prevalence of risk factors for AS in young individuals draws
attention to the need for adopting preventive plans.
PMID- 10668228
TI - Comparison between right and left ventricular myocardia during the human fetal
period. Stereological evaluation.
AB - PURPOSE: To develop a stereological comparison between right (RV) and left
ventricle (LV) myocardium during the third human gestational trimester. METHODS:
Five human fetal hearts of the third trimester provided representative samples of
5 RV myocardium and 4 LV myocardium. The material was fixed in 10% buffered
formaldehyde, and processed through routine methods. Fifteen microscopic fields
were randomly chosen and counted in each ventricular myocardium using an "M-42"
test system. The following stereological parameters were assessed: Vv (%), Lv
(micron 2), Sv (micron 2/micron 3), Vp (micron 3), Nv (1/mm3) and total N.
RESULTS: No significant difference between the stereological parameters of the
myocardial structures assessed was evidenced, when comparing RV and LV.
CONCLUSION: Right and left human ventricular myocardium are very similar during
the fetal period at least in regard to their structural aspects.
PMID- 10668229
TI - Surgical revascularization of posterior coronary arteries without cardiopulmonary
bypass.
AB - OBJECTIVE: To assess the results observed during the early postoperative period
in patients who had the posterior coronary arteries revascularized without
cardiopulmonary bypass (CPB), in regard to the following parameters: age, sex,
bypass grafts types, morbidity and mortality. METHODS: From January 1995 to June
1998, 673 patients underwent myocardial revascularization (MR). Of this total,
607 (90.20%) MR procedures were performed without CPB. The posterior coronary
arteries (PCA) were revascularized in 298 (44.27%) patients, 280 (93.95%) without
CPB. The age of the patients ranged from 37 to 88 years (mean, 61 years). The
male gender predominated, with 198 men (70.7%). The revascularization of the
posterior coronary arteries had the following distribution: diagonalis artery (31
patients, 10%); marginal branches of the circumflex artery (243 patients, 78.7%);
posterior ventricular artery (4 patients, 1.3%); and posterior descending artery
(31 patients, 10%). RESULTS: Procedure-related complications without death
occurred in 7 cases, giving a morbidity of 2.5%. There were 11 deaths in the
early postoperative period (mortality of 3.9%). CONCLUSION: Similarly to the
anterior coronary arteries, the posterior coronary arteries may benefit from
myocardial revascularization without CPB.
PMID- 10668230
TI - Rheumatic carditis treated with high doses of pulsetherapy methylprednisolone.
Results in 70 children over 12 years.
AB - PURPOSE: To report the result of patients treated with IV methylprednisolone
divided into three groups and compare their follow-up during the last 12 years.
METHODS: Seventy children with active rheumatic carditis (76 episodes) in heart
failure Class III and IV (NYHA) were studied. The diagnosis was based on modified
Jones' criteria. After ruling out infections and strongyloidiasis, treatment with
IV methylprednisolone bolus was started three times a week until the laboratory
tests became negative. Patients were divided into 3 groups, according to the time
of hospital admittance: Groups 1, 2 and 3, comprising of 40, 18 and 12 children,
respectively. RESULTS: Eighteen children in Group 1 (45%) were in their 1st
attack: 2 series of pulsetherapy were used in 10 (25%), 3 in 9 (23%) and 4 in 21
(52%). In Group 2, 14 cases (77%) were in their 1st attack: 2 series were used in
7 (39%), 4 in 9 (50%) and 5 in 2 (11%). The echocardiogram showed a flail mitral
valve in 12 (66%) of these patients (1 death occurred after mitral valvoplasty).
In Group 3, 6 patients needed 5 or more series of pulsetherapy and a flail mitral
valve was present in 5 (41%). One child underwent mitral valve replacement while
still in the active phase, after 8 series of pulsetherapy, and another died. The
number of patients who needed 5 or more series was significantly higher in Group
3. CONCLUSION: There were variations in the presentation and evolution of the
cases during these 12 year. The established pulsetherapy protocol continues to be
useful to treat severe cases.
PMID- 10668231
TI - Evaluation of the heart rate and arrhythmias following the maze procedure for
chronic atrial fibrillation.
AB - PURPOSE: To assess the presence and the prevalence of arrhythmias and the
variability of the heart rate in the medium-term postoperative period following
the maze procedure for chronic atrial fibrillation (AF). METHODS: Seventeen
patients with a mean age of 51.7 +/- 12.9 years, who previously underwent the
maze procedure without cryoablation for chronic atrial fibrillation, were
evaluated with the 24 hour electrocardiogram (ECG)--Holter monitoring from the
6th month after the operation. Valvular and coronary procedures were
concomitantly performed. RESULTS: The mean heart rate during Holter monitoring
was 82 +/- 8 bpm; the maximal heart rate was 126 +/- 23 bpm and the minimal heart
rate 57 +/- 7 bpm. Sinus rhythm was found in 10 (59%) patients and atrial rhythm
was found in 7 (41%). Supraventricular extrasystoles had a rate of 2.3 +/- 5.5%
of the total number of heartbeats and occurred in 16 (94%) patients. Six (35%)
patients showed nonsustained atrial tachycardia. Ventricular extrasystoles, with
a rate of 0.8 +/- 0.5% of the total heartbeats, occurred in 14 (82%) patients.
The chronotropic competence was normal in 9 (53%) patients and attenuated in 8
(47%). The atrioventricular conduction (AV) was unchanged in 13 (76%) patients
and there were 4 (24%) cases of first degree atrioventricular block (AVB).
CONCLUSION: After the maze procedure, the values for the mean heart rate, AV
conduction and chronotropic competence approach the normal range, although some
cases show attenuation of the chronotropic response, first degree AV block or
benign arrhythmias.
PMID- 10668232
TI - Cutting balloon angioplasty for intrastent restenosis treatment.
AB - We describe here two patients with angiographic diagnosis of intrastent
restenosis and regional myocardial ischemia. One stent restenosis was located in
a native coronary artery and the other in a vein graft. Both were treated with
cutting balloon angioplasty (CBA), inflated at low pressures. Angiographic
success was obtained and both patients were discharged in the day after the
procedure. Cutting balloon angioplasty using low inflation pressures achieved
important luminal gains, in these two cases of intrastent restenosis. Further
studies are necessary before the effectiveness of this procedure can be precisely
defined.
PMID- 10668233
TI - Myxoma of the mitral valve.
AB - Only rarely do myxomas originate from the mitral valve. This is the report of a
49-year-old woman presenting with congestive heart failure. The diagnosis of an
intracardiac tumor involving the anterior cuspid of the mitral valve was made by
transesophageal echocardiography. The patient underwent surgery for tumor
resection and plasty of the valve was made with reconstruction and preservation
of the valve. The diagnosis of myxoma was confirmed by histology. This is the
23rd case of myxoma of the mitral valve reported in the literature.
PMID- 10668234
TI - Systemic hypertension in heart transplant recipients.
PMID- 10668235
TI - Beta-adrenergic pathway in healthy and hypertrophied hearts.
PMID- 10668236
TI - [Organization of the network for the study of the Trypanosoma cruzi genome].
AB - Five years ago the Special Programme for Research and Training in Tropical
Diseases (TDR) from the World Health Organization (WHO) launched the Parasite
Genome Project. The aims were to obtain information on genome organization and
gene discovery in five parasites, namely, Schistosoma, Filaria, Leishmania and
Trypanosomas brucei and cruzi. Organization of research networks for each
parasite under study, promotion of international collaboration and training of
researchers in developing countries, were also main objectives of the programme.
After five years, a large amount of information has been obtained, which is now
available to researchers in the field.
PMID- 10668237
TI - [Cruzipain, major cysteine proteinase of Trypanosoma cruzi: sequence and genomic
organization of the codifying genes].
AB - Cruzipain is the major cysteine proteinase present in Trypanosoma cruzi, the
parasite causing the American Trypanosomiasis, Chagas disease. The enzyme is
encoded by a high number of genes (up to 130 in the Tul 2 stock) placed in head
to-tail tandems, and located in two to four chromosomes. The simultaneous
expression of several different genes results in the production of a complex
mixture of isoforms. Those known as a group as "cruzipain 1" differ essentially
at the level of the C-terminal domain, in their amino-acid sequence and in their
type of N-glycosylation. The existence of a more distantly related cysteine
proteinase, "cruzipain 2", has been demonstrated; it differs markedly,
particularly at the level of the catalytic moiety.
PMID- 10668238
TI - [Trypanosoma cruzi genome: transcriptional mapping and karyotype correlation;
molecular characterization of a surface antigen from the Tc13 family].
AB - We describe herein the genome mapping of Trypanosoma cruzi, the etiological agent
of Chagas' disease, by hybridization of a cosmid library gridded in high density
filters with cDNA from an epimastigote expression library as probes. We also show
the correlation of some cosmid contigs with parasite chromosomal bands. With
libraries from the T. cruzi Genome Project we have characterized a new member of
the Tc13 family belonging to the superfamily of trypomastigote surface antigens.
Starting with a Tulahuen strain (Tul 2 stock) clone, homologous to these
antigens, we have sequenced and characterized the complete gene in the CL Strain
(CL Brener clone). We have also found homologies with different ESTs which
characterization would lead to further knowledge of this antigen family.
PMID- 10668239
TI - [Contribution of the Trypanosoma cruzi Genome Project to the understanding of the
pathogenesis of Chagas disease].
AB - The Trypanosoma cruzi Genome Project (TcGP) is developed by a consortium of
laboratories brought together by two international agencies, WHO/TDR and CYTED.
The TcGP is an important tool for the study of Chagas disease. It provides
researchers and clinicians with information about expressed parasite genes (see
TcGP database, http:@gene.dbbm.fiocruz.br) and with an important number of
genomic libraries and probes (ESTs). We show with four examples how the TcGP
contributes to the understanding of the pathogenesis of this infection. 1) We
demonstrate how to derive antigens from ESTs, an important feature regarding the
generation of anti-cardiac receptor antibodies in chagasic patients. 2) We
introduce concepts such as proteome vaccinome and pathonome that include all
techniques needed to analyze quickly the growing amount of genomic information.
3) We show that the genomic regions that have been already sequenced give clues
as to the plastic nature of the parasite nuclear genome. Finally, 4) we show how
the genome sequences can be used to study the parasite DNA that is associated to
the cardiac lesions.
PMID- 10668240
TI - [Chagasic myocardiopathy: historical perspective].
AB - Considerable advances in the clinical pathological and pathogenic aspects of
Chagas disease have been made since the Brazilian physician Carlos Chagas
described the disease in 1909. The disease caused by the flagellate protozoon
parasite Trypanosoma cruzi is transmitted to humans by a blood sucking triatomine
and much less frequently by blood transfusion. It is estimated that 18 million
are infected and that about 100 million people from Latin America are at risk of
contracting T. cruzi infection. One of the most important contributions to the
knowledge of Chagas' disease has been the recognition of the natural history of
the disease, which can be divided into three well defined periods: 1. The acute
stage; 2. An undetermined or undifferentiated stage and 3. The chronic stage. The
primary infection (first stage) occurs mostly unrecognized and clinically
apparent acute chagasic myocarditis may appear in less than 5% of the infected
individuals, usually children living in endemic areas. The majority of the cases
of acute myocarditis are mild and reversible. Autopsied cases of acute chagasic
myocarditis are uncommon and correspond to exceptionally severe or fulminant
forms showing diffuse myocardial damage with myocytolisis, degenerative changes
of myocardial fibers and marked intersticial cellular infiltration. The acute
clinical manifestations of the infected individuals include fever, muscular pain,
sweating, swollen lymph nodes, hepatospienomegaly. Following this initial stage,
all patients enter the undifferentiated or undetermined stage of the chronic
period (second stage), which lasts between 10 to 20 years. Of these, 20 to 30%
(depending on marked geographical differences) develop symptoms or signs of
visceral damage conforming the cohort that enter the third stage. Although
megaesophagous and megacolon are not uncommon (mainly in Brazil), the most
frequent and important clinical manifestation is a dilated cardiomyopathy. Thus,
70% or more of the infected individuals will never show any clinical
manifestation of the disease. The ajmaline test and the endomyocardial biopsy
are, probably, the most sensitive methods to unmask latent forms of chagasic
myocarditis during the undifferentiated stage. In the most advanced stages of
chronic chagasic myocarditis, pathological findings are those of a dilated
cardiomyopathy. At autopsy, the apical aneurysm with thrombus in it is a frequent
and distinctive finding. The histopathological picture is that of an active and
chronic microfocal and disseminated myocarditis. In some cases fibrosis may be
confluent, which accounts for the electrocardiographic patterns of myocardial
necrosis. The widespread distribution of cardiac lesions also constitute the
substrate for atrioventricular and intraventricular conduction disturbances and
for atrial and ventricular arrhythmias. The clinical diagnosis of Chagas' heart
disease is based on a triad of: positive epidemiology, positive serology and a
combination of clinical findings (suggestive electrocardiograhic abnormalities,
apical aneurysm, cardiac enlargement). The electrocardiogram in the most advanced
forms, usually shows sinus bradycardia, right bundle branch block with or without
left anterior hemiblock, primary T wave abnormalities, pathological Q waves and
multiform ventricular premature beats. The pathogenesis of the myocardial lesions
of acute and also chronic chagasic myocarditis appears to be related in large
part to autoimmune mechanisms. The lack of correlation between the location and
number of parasitized fibers and the severity, type, and extension of
degenerative and inflammatory lesions supports this assumption. Experimental and
clinical studies have demonstrated the presence of antibodies directed against
different components of T. cruzi and crossreacting with human antigens in
patients with chronic chagasic myocarditis. Microvascular dysfunction, myocardial
ischemia and autonomic nervous system impairment have also been implica
PMID- 10668241
TI - Susceptibility and resistance to insecticides of Chagas disease vectors.
AB - Chemical control of Chagas disease vectors appears to be the best practical way
to reduce the incidence of the disease. DDT was initially tested in the 1950s for
the campaigns of control of Chagas disease vectors. Its low level of
effectiveness against triatomine caused the failure of these control actions. HCH
was then introduced in the southern cone and Dieldrin in the north of
Latinoamerica. Starting in the late 1960s anticholinesterasic organophosphorus
and carbamate compounds were introduced in the control of Chagas vectors. The use
of pyrethroid compounds began in 1980. This family of insecticides is now the
most important tool in triatomines control because of its favorable toxicological
properties. Other types of insecticides also studied for Chagas vector control
were the insect growth regulators and the antifeeding compounds. Because of the
mode of action of these insecticides they are now considered just a potential
complement of neurotoxic insecticides for integrated programmes of Triatomines
control. Innovative formulations such as fumigant canister and insecticidal
paints have been successfully developed in Latinoamerica with the World Health
Organization support. Resistance to insecticides of triatomines is not yet a
great problem in Chagas vectors. However, some resistant strains to pyrethroids
have been found in Rhodnius prolixus from Venezuela and in Triatoma infestans
from Brazil. Some cases of T. infestans incipient resistance to deltamethrin have
been detected in Argentina. According to the control tools now available it is
possible to expect the interruption of vector transmission of Chagas disease in
the near future.
PMID- 10668242
TI - [Control campaigns against Triatoma infestans in a rural community of
northwestern Argentina].
AB - Control campaigns against Triatoma infestans, the principal vector of Trypanosoma
cruzi, have relied on the application of residual insecticides and have regarded
the system as homogeneous. Reinfestation generally starts in peri-domestic
residual foci or in preexisting foci that escaped spraying for diverse reasons.
From these foci T. infestans adults actively invade other sites, or they are
transported passively within objects or goods from infested communities. In the
absence of additional spraying of insecticides after the attack phase,
domiciliary reinfestation expanded exponentially to return to pre-spraying levels
in 3-4 years in Amama, Santiago del Estero. However, the rate of recovery of T.
infestans abundance was much lower than that predicted by a simple mathematical
model or in experimental field studies. Reinfestation did not progress
homogeneously within the village. Two longitudinal studies in Santiago del Estero
revealed that the presence of T. infestans-infested peri-domestic sites increased
the risk of domiciliary reinfestation. "Key" sites where reinfestation started
early were goat or sheep corrals, pig corrals, chicken houses, and store-rooms.
Peri-domestic reinfestation is likely the result of multiple factors, such as
insecticide breakdown by climatic agents, and the greater surface and
availability of refuge and hosts in peri-domestic rather than domiciliary sites.
Such environmental heterogeneity generates insecticidal effects heterogeneity and
increases the probability of persistence of T. infestans even under control
pressures. Several studies showed that sustained surveillance after the attack
phase decreased sharply the domiciliary colonization by T. infestans and the
percentage of bugs infected with T. cruzi, and the local incidence of infected
children. The sustained elimination of T. infestans demands a scientific approach
that is not only centered in insecticide use but that also includes the
environment and house-holders in their specific social and political scenario.
PMID- 10668243
TI - [A tribute to Patricio Cossio. His contribution to the immunopathology of Chagas
disease].
PMID- 10668244
TI - [Myocardial cell response to Trypanosoma cruzi infection].
AB - The aim of this study is to establish the response of cardiac myocytes to the
infection with Trypanosoma cruzi. The role of myocardial cell proliferation on
heart remodelation and the ability of these cells to produce nitric oxide and
control intracellular parasite growth during T. cruzi infection were evaluated.
The presence of proliferating cell nuclear antigen (PCNA) was determined in
myocardial cells of Wistar rats infected with T. cruzi, resulting in a
significant increase of PCNA+ labelling in all stages of disease. The ability of
myocardial cells to control growth of intracellular parasites and the production
of nitric oxide were evaluated in cultures of cardiac myocytes obtained from
neonatal rats. Different combinations of cytokines were added to culture media.
The number of cardiac cells displaying intracellular amastigotes was lower in
cultures supplemented with IL-1b, TNF-a and IFN-g than with other cytokine
combinations and controls. The addition of cytokines resulted also in an increase
of nitric oxide production in both infected and non-infected controls. These
results demonstrate that myocardial cells participate actively in the response of
the heart to the infection with T. cruzi.
PMID- 10668245
TI - [Pathogenesis of human chronic chagasic myocarditis].
AB - Studies carried out during the last decades provided evidence in support of an
autoimmune pathogenesis for chronic chagasic myocarditis. This opinion was based
on 1) the demonstration of molecular mimicry between parasite and host antigens,
2) the appearance of autoantibodies recognizing heart epitopes during the chronic
phase of infection, 3) the induction of myocarditis and electrocardiographic
alterations in animals immunized with whole parasites, parasite fragments or with
biochemically-defined antigens, 4) the isolation from the heart of inflammatory
infiltrates of B cells elaborating antibodies against myocardial antigens and 5)
or of T cell clones reacting with heart epitopes and 6) induction of heart and
nervous tissue alterations by transfer of lymphocytes from infected animals into
naive syngeneic hosts. However, the characteristics of the inflammatory
infiltrate in human myocarditis, displaying a wide variety of cells, many of them
not involved in autoreactivity, such as the presence of giant cell granulomas and
abundant eosinophils, as well as its focality and asynchrony, and the frequent
association with pericarditis, casts doubts about the possibility of autoimmunity
being responsible for the perpetuation of the myocarditis. This is supported by
the recent observation that treatment of asymptomatic patients with trypanocidal
drugs prevents the development of cardiopathy and that parasite components,
either antigens or genomic fragments, are present at the site of the inflammatory
lesions. On the basis of this new evidence, other alternative pathogenetic
mechanisms should be sought to explain the appearance of a polymorphic long
lasting myocarditis that needs the presence of tiny fragments of parasites to
develop. In addition to the well known immunological pathogenesis, the link
between such a small amount of parasite components, below the level of
microscopic detection, and the induction of such an extensive inflammatory
infiltrate, represents interesting avenues for research in the near future.
PMID- 10668246
TI - [Trypanosoma cruzi pathology. Strain dependent?].
AB - There is agreement today about the role that the characteristics of the
population of Trypanosoma cruzi play in the pathogenesis of the different
clinical forms of Chagas disease. In our laboratory, we have studied the outcome
of the infection of mice with two populations with polar biological behaviour: RA
and CA-I. We have demonstrated that the neuromuscular damage is, in part,
mediated by different T cell subsets. We have also observed that the T cell
phenotype responsible for the pathology and the targetted tissues depend on the
parasite population. Although we found no differences regarding the reactivity of
IgG to native nerve structures in sera from mice infected with either strain, it
is presumed that the humoral response would play an additional role in the
development of strain-dependent neuromuscular pathology since passive transfer of
sera from mice infected with RA triggered alterations of the nerve action
potential whereas sera from CA-I-infected mice did not. We have also detected a
reduction in the fertility of female mice infected with CA-I/K98, whereas females
infected with RA showed no difference in comparison with uninfected controls.
However, congenital transmission was only observed in mice infected with RA. The
differences observed in fertility, in newborn survival, and in the number of
fetal resorptions in mice infected with the myotropic strain could be attributed
to the uterine inflammatory response, since no estrous alterations were observed
between infected and control groups.
PMID- 10668247
TI - Overview of molecular mechanisms in chagasic cardioneuromyopathy and achalasia.
AB - Evidence accumulated by our investigations over the years give adequate proof for
the existence of circulating antibodies in Chagas disease which bind to beta
adrenergic and muscarinic cholinergic receptor of myocardium. The interaction of
agonist-like antibodies with neurotransmitter receptors, triggers in the cells
intracellular signal transductions that alter the physiological behaviour of the
target organs. These events convert the normal cells into pathologically active
cells. The interaction of antibodies with heart beta adrenergic and cholinergic
receptors triggers physiologic, morphologic, enzymatic and molecular alterations,
leading to tissue damage. The analysis of the prevalence and distribution of
these antibodies reveals a strong association with cardiac and esophageal
autonomic dysfunction in seropositive patients in comparison with those without
alteration of the heart and esophagus autonomic disorders: therefore, the
presence of these antibodies may partially explain the cardiomyoneurophathy and
achalasia of Chagas disease, in which the sympathetic and parasympathetic systems
are affected. The deposit of autoantibodies behaving like an agonist on
neurotransmitter receptors, induceds desensitization and/or down regulation of
the receptors. This in turn, could lead to a progressive blockade of
neurotransmitter receptors, with sympathetic and parasympathetic dennervation, a
phenomenon that has been described during the course of Chagas cardioneuropathy
and achalasia. The clinical relevance of these findings is the demonstration,
using biomolecules, of a strong association between the existence of circulating
autoantibodies against peptides corresponding to the second extracellular loop of
the human heart beta, adrenoceptor and M2 cholinoceptor in chagasic patients, and
the presence of dysautonomic symptoms, making these autoantibodies a proper early
marker of heart and digestive autonomic dysfunction.
PMID- 10668248
TI - [TH1 response in the experimental infection with Trypanosoma cruzi].
AB - Specific antibodies and the activation of phagocytic cells by IFN-gamma are the
key elements of the immune response involved in protection of the T. cruzi
infected host. The central role of the IFN-gamma in vivo seems to be the
activation of the inducible nitric oxide synthetase of macrophages (iNOS) and the
production of nitric oxide (NO degree) for the intracellular destruction of the
parasite. Interleukin 12 (IL-12), the cytokine that stimulates NK cells for IFN
gamma production, seems to trigger the TH1 response in the acute phase. Other
cell types, such as lymphocytes Thy-1+CD4-CD8-, CD4+ and CD8+, are also involved
in IFN-gamma production. The down regulation of the TH1 response could in part
depend on the decrease in the macrophage activation, as a result of the
controlled parasite burden, and on the production of IL-10 and transforming
growth factor beta (TGF-beta). The protective TH1 immune response seems to be
also related to both the tissue damage and the alterations of the immune response
observed during the infection. We studied the kinetics of both NK cell activity,
and the production of IL-12 and/IFN-gamma by spleen cells, as well as the seric
levels of these cytokines, in BALB/c and C3H mice infected with T. cruzi,
Tulahuen strain. In the spleen, we found that the production of IL-12 and the NK
cell activity increased in the very early acute infection, and that in C3H the
effect was higher than in BALB/c mice. IFN-gamma increased in C3H at the same
time, but in the BALB/c strain it increased later in the acute phase. The
infection induced a very early increase in the seric levels of IL-12, that
remained high throughout the acute phase, in both mouse strains. However, the
levels of IFN-gamma in the serum increased a few days before the peak of
parasitemia, reaching higher values, and earlier, in BALB/c than in C3H mice.
Surprisingly, in the chronic infection IL-12 production remained high in both
mouse strains, but IFN-gamma production was only observed in BALB/c mice. The
immune response was predominantly TH1 in both mouse strains, in spite of the
higher susceptibility of BALB/c compared to C3H. The early control of the
parasite burden could be evaluated as the expression of the TH1 response in
spleen cells, while the seric levels of IL-12 and IFN-gamma would be related to
the induction of tissue damage. Our data indicate that the protective TH1 immune
response has a different expression according to the host-parasite relationship,
and that the factors controlling the response are of primary importance to
determine the quali- and quantitative expression of IL-12/NK/IFN-gamma as well as
their involvement in resistance and tissue damage.
PMID- 10668249
TI - [Control of the transmission of Trypanosoma cruzi in Argentina 1999].
AB - Approximately 2 million people in Argentina are infected with Trypanosoma cruzi,
the etiologic agent of Chagas disease, thereby constituting the major tropical
disease in the country. As in other six Southern Cone countries, Triatoma
infestans is the only or major vector of T. cruzi among human and domestic
animals. In Argentina, a vertically structured National Chagas Control Program
was established in 1962. Such a program pursued the elimination of domestic and
peri-domestic populations of T. infestans through insecticidal spraying, and the
serological control of blood donors to prevent transfusion-related infections.
This program strongly reduced the nation-wide serological prevalence of T. cruzi
in the population. For example, in 18 or 20 year-old men drafted into military
service, the seroprevalence decreased from 10.1% in 1964 for those who had been
born in 1944 to 1.9% in 1993 for those born in 1975. However, the vertical
strategy failed to reach and sustain the surveillance phase in widespread rural
areas with disperse populations due to its intrinsic limitations and the reduced
priority level assigned to rural health programs. An alternative, horizontally
structured control strategy of T. infestans was developed and assayed in the
Province of Santiago del Estero between 1985-1989, and 1991-1992. The projects
demonstrated that insecticidal spraying carried out with community participation
combined effectiveness and commitment in such a way as to produce a strong impact
on house reinfestation and the extension of the area under entomological
surveillance. This experience has been transferred in a chain of responsibilities
to the personnel of the National Chagas Control Program, using participating
workshops, procedural guidelines, and practical training. This personnel
transferred the strategy using similar methods to the field health care agents
and volunteers chosen by their own communities (community leaders). After the
workshops, the leaders received all the materials needed to install and develop
the ongoing surveillance activities: third generation pyrethroid insecticides,
manuals, hand-operated sprayers, and sensor boxes to detect domiciliary
infestations. From 1993 to 1998, a total of 15,000 health care agents or
community leaders were trained. A total of 675,000 houses were sprayed with
residual insecticides in the attack phase, and 850,000 houses entered the
surveillance phase. This is the first time that such large coverage has been
accomplished in Argentina. The network of laboratories installed a quality
assurance program to current serological procedures applied to blood donors,
organ transplant, and the detection and treatment of newborns to women sero
reactive for T. cruzi in Argentina. We expect to interrupt the vector-mediated
transmission of T. cruzi in the next 18 months, but the sustainability of such a
program depends on, at least, additional work with the community to achieve a
change of attitudes and practices related to house infestation for the next 10
years. A social effort will be needed to cover those expenses, but the expected
economic returns exceed largely the cost of any such program, as suggested by
cost-benefit studies. To illustrate, the annual treatment costs of one Chagas
patient can help maintain 25 households free from triatomine bugs in Argentina.
PMID- 10668250
TI - [Elimination of vectorial transmission of Chagas disease in Brazil].
AB - The control of vectorial transmission of Chagas disease in Brazil has been
systematized and structured into a national program since 1975 when regulations
were set up on the basis of entomological and sero-epidemiological studies which
permitted the delimitation of areas at risk of vectorial transmission in the
whole country as well as the orientation of the chemical control of domiciliary
vector populations. The authors present the original data collected throughout
the years comparing them with the present data. The evaluation reveals a virtual
interruption of the transmission for Triatoma infestans and the remaining
possibility of transmission, at very low levels, for native vector species in
different areas of the country. It is emphasized that it is important to maintain
constant entomological vigilance in order to prevent the reestablishment of
transmission.
PMID- 10668251
TI - [Current status of the control of Chagas disease in Colombia].
PMID- 10668252
TI - [Towards the elimination of the transmission of Trypanosoma cruzi in Honduras and
Central American countries].
AB - Central America is composed of seven countries: Belice, Costa Rica, El Salvador,
Guatemala, Honduras, Nicaragua and Panama. Chagas disease exists in all seven
countries, but with major prevalence in El Salvador, Guatemala, Honduras and
Nicaragua. The main species of triatomine vectors are: Rhodnius prolixus,
Triatoma dimidiata y Rhodnius pallescens. In 1997 the Central American countries
launched an Initiative for the Vectorial and Transfusion Transmission Control of
Chagas disease. The objectives of the Initiative are: 1. elimination of Rhodnius
prolixus, 2. control of Triatoma dimidiata and 3. serological screening for
Trypanosoma cruzi of 100% of the blood donors. This Initiative is supported by
the Resolution for "The Elimination of Transmission of Chagas Disease", of the
World Health Assembly in 1998.
PMID- 10668253
TI - [Progress towards the interruption of transmission of Chagas disease in the
southern countries].
AB - The epidemiological and entomological data and the trends observed in the
decreasing of the incidence of infection in young age groups indicate that only
ninety years after the discovery of Chagas disease, the control of vectorial and
transfusional transmission has reduced the incidence by 70% in the Southern Cone
countries (Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay). This has
been accomplished thanks to the political and financial engagement of the
concerned governments who have invested US$340 millions since 1991 to the
present. The initiatives to interrupt transmission of Chagas in the Andean
countries and the Central American countries have begun their activities in 1997
and the evolution of the control operations allows to forecast the complete
interruption in these areas before the year 2010 to comply with the mandate of
Resolution WHA. 52.14 of the World Health Assembly in May 1998.
PMID- 10668254
TI - [Risk of Chagas disease through transfusions in the Americans].
AB - The safety of blood transfusion depends on a country's laws, decrees and/or
regulations concerning the collection, production and use of blood and blood
derivatives. It also needs governmental enforcement of those instruments, as well
as trained health professionals to obtain blood and produce blood derivatives,
following total quality control procedures both at collection and production, and
use. By 1998, all Latin American countries had laws, decrees and/or regulations
that governed the production and use of blood, with the exception of El Salvador
and Nicaragua. During the past six decades, economic need in Latin America has
promoted migration to urban areas. Consequently, at present time, more than 60%
of the population live in cities, which increases the probability of finding
blood infected by Trypanosoma cruzi among donors. Unless all the blood from
infected donors is discarded, the possibility of transmitting infection by
transfusion remains. Moreover, infection by T. cruzi through transfusion is a
potential problem in developed countries, now that tens of thousands of
individuals from Latin America have migrated to the United States, Canada,
western Europe, Australia and Japan. When donors are not screened for T. cruzi,
the risk of transfusing infected blood is greater at higher prevalence rates of
infection in the donor population; it also increases with the number of
transfusions received by the recipient. In 1993, Bolivia presented the highest
risk of receiving infected blood and becoming infected with T. cruzi; this
country was followed by Colombia, El Salvador and Paraguay. As the coverage of
HIV screening became almost universal, the probability of receiving blood
infected by HIV and becoming infected was low in all countries. In the case of
hepatitis B (HVB), the highest probability of infection was in Bolivia, Nicaragua
and Guatemala. This probability was even greater for Hepatitis C (HVC), given the
low coverage of donor screening in all countries. In absolute numbers, the
highest potential for occurrence of cases of T. cruzi infection were present in
Bolivia, the greatest number of HVC cases in Colombia, and the most cases of HVB
in Nicaragua. Only in two countries, Bolivia and Colombia, HIV could be
potentially transmitted by blood transfusion. Although the situation has improved
since 1993, and 100% of donors are being screened for T. cruzi in Argentina,
Colombia, Ecuador, El Salvador, Honduras, Paraguay, Uruguay and Venezuela,
success will only be assured by: total enforcement of the law by governments;
implementation of altruistic and volunteer blood donations, exclusively; 100% of
donors are screened for communicable diseases; the collection, processing and use
of blood strictly follow quality control norms; reagents used in diagnosis are
adequate, and the use of blood and blood derivatives is limited to cases where it
is only absolutely necessary.
PMID- 10668255
TI - [Transfusion transmission of Chagas disease in Honduras and other Central
American countries].
AB - The transmission of Trypanosoma cruzi through blood transfusion is the second
most important way of acquiring Chagas disease. This form of transmission
transcends the vectorial transmission in many geographical areas. Honduras has
developed a successful program for the control of transfusional transmission,
based on the serological screening of blood donors, which is supported by law,
making it mandatory. This experience has been extended to other Central American
countries, supported by PAHO. Actually in the framework of the Initiative of the
Central American countries for the elimination of the transmission of Chagas
disease, launched in 1997, the control of transfusional transmission is becoming
a reality.
PMID- 10668256
TI - [Control of congenital transmission of Trypanosoma cruzi in Argentina].
AB - The vertical transmission of Trypanosoma cruzi has been augmenting its relative
importance as vector and transfusion-mediated transmission routes have been, and
continue to be, increasingly controlled. The vertical transmission of T. cruzi
cannot be prevented; but early detection and treatment of congenital infection
achieve cure rates close to 100%. In Argentina, the Subprogram of Control of
Pregnant Women examined 58,196 women from 13 provinces in 1997 and found a 9%
seropositivity to T. cruzi. In spite of such high maternal prevalence rates of T.
cruzi, only a small proportion of live newborns to infected mothers acquires the
infection. The probability of vertical transmission was 1.9% (range: 0.1% to
3.5%) in surveys carried out in the '70s, and 2.5% (range: 0.7% to 10.4%) in
others conducted in the '70-'80s. Other more recent studies in Argentina
estimated the probability of transmission in 2.6%-6.7%, but studies from Paraguay
estimated 10.5% by PCR or serodiagnosis. The microhematocrit technique is the
recommended parasitologic method to detect congenital infection. Routine
serodiagnosis that detects IgG against T. cruzi is only helpful after the newborn
reaches 6 months of age. Detection of specific IgM using recombinant antigens and
PCR constitute excellent alternatives, but their feasibility from operational and
cost-effective viewpoints in affected endemic areas remains to be considered. In
a longitudinal project carried out in Maternidad Nuestra Senora de la Merced in
the city of Tucuman between 1992-1994, the majority of congenital cases were
asymptomatic. They were diagnosed through the microhematocrit technique, but a
number of cases could only be detected later as a result of the parasitological
and/or serological follow-up. Of a total of 32 newborns infected with T. cruzi
who were treated with nifurtimox or benznidazole, 30 had a negative
microhematocrit and serodiagnosis between 6 months and 2 years post-treatment.
The magnitude of congenital transmission, and its associated morbidity and
mortalidad, largely justify the efforts needed to detect T. cruzi infection in
the mothers and newborns. This project demonstrated that the transmission of T.
cruzi can be successfully controlled at a provincial scale through a specific
program inserted in the primary health care system or at the first level of
attention. The congenital transmission of T. cruzi clearly represents a public
health problem in areas that in the past were of active transmission, even years
after being under entomologic surveillance.
PMID- 10668257
TI - [The transmission de Chagas disease in Salta and the detection of congenital
cases].
AB - Data on the prevalence of Trypanosoma cruzi infection is presented for the
province of Salta, Argentina. Special emphasis is given to the detection of
congenital transmission and to the economic benefits of preventing Chagas'
disease. Seroepidemiological data obtained from 20 year old army draftees
revealed a reduction, from 22.7 to 11.11% between 1964 and 1985. In university
students, a rate of 0.96% was found in 1998. Surveys carried out during 1996
showed that more than 15% of the pregnant women analyzed carried T. cruzi
infection, particularly in the north of the province. This situation brings about
a high risk of appearance of congenital cases and represents an opportunity to
test the most adequate strategies for detection. By applying systematically
microhematocrit, hemoculture and PCR methods, to umbilical chord blood, an
increase in the early detection of congenitally infected babies is being
achieved. In 1992-94, very high seroprevalence rates of infection were found
among indians of the Chaco region of Salta. The overall rate was 37%, but there
were 5 localities where more than 54% of the population was infected. These
numbers indicate that, in vast areas of the provincial territory, fight against
vector bugs must not merely consist of surveilance activities, but rather of
renewed spraying attacks. The fight must include control of pregnant women and
blood banks. An economic analysis of the economic return, calculated only for
spraying activities and for the Department of Anta (Salta), indicated a net
present value of over 7 million dollars and an internal rate of return exceeding
60%.
PMID- 10668258
TI - [The chemotherapy of Chagas disease].
AB - To date, Chagas disease has defied all attempts to develop an efficient and safe
chemotherapy. Drugs effective on T. cruzi as trypanocidal agents may be
classified as (a) drugs of extensive clinical use: Nifurtimox and Benznidazole;
(b) drugs of restricted clinical use: azoles (e.g. Ketoconazole, Econazole;
Miconazole); Amphotericin B; Allopurinol, Allopurinol ribosides and Primaquine;
(d) drugs effective on T. cruzi and in experimental Chagas disease (murine
model): alkyllysophospholipids; 5-amino-imidazole-4-carboxamides; bisbenzyl
isoquinolines; cruzipain (crucein) inhibitors; Gossipol; phenothiazines; d) drugs
effective in vitro without other reported effects, acridines, actinomycin D,
Crystal Violet (gentian violet), diterpenes (Mikania obtusata); N,N'-dimethyl-2
propen-1-amine, epoxidienthiol carbamates, Fe-chelators, guanyl hydrazones, o
naphthoquinones (beta-lapachone); quinoids (miconidine; tingenone); Olivacine,
phenazine methosulfate, phenoxi-phenoxyl drugs, Proadifen, pyridinium azolate
betaines, sesquiterpenes (Lychophora sp), sesquiterpene lactones,
tetrahydrocarbazoles, DL-alpha-trifluoromethylarginine, triphenylmetane dyes. It
is generally agreed that Nifurtimox and Benznidazole (a) are effective on acute
Chagas' disease, but may not be effective in the chronic phase; (b) their effect
depends on the susceptibility of T. cruzi strains to the drug; (c) they produce
adverse effects in patients that may prevent prolonged treatments; they are
genotoxic and produce biochemical damage in the mammalian tissues. Redox-cycling
of Nifurtimox and Benznidazolee generates "reactive oxygen species" which explain
the biological effects. At variance with the mammalian host, T. cruzi is
deficient in antioxidant enzymes which are essential to prevent oxidative damage.
Azoles are effective inhibitors of T. cruzi growth in vitro and in vivo since
they inhibit sterol C14-delta 24(25) demethylase, an enzyme catalysing ergosterol
production. Azoles reduce parasitemia and extend the survival of infected mice
but do not produce parasitological cure and their clinical effectiveness is
questionable. Allopurinol allopurinol ribosides and related compounds inhibit T.
cruzi hypoxantine-guanine ribosyl transferase, thus preventing the synthesis of
adenylic and guanylic acids and also DNA. They reduce parasitemia and negativize
xenodiagnosis but these effects may not be permanent, which invalidates their
clinical use. Cysteine-protease inhibitors recognize T. cruzi protease
(cruzipain, crucein) active site, thus allowing a covalent linkage with the
inhibitor. These peptide inhibitors are effective in acute and chronic murine
models. Phenothiazines inhibit trypanothione reductase and a specially favoured
fit is a small 2-substitued 2-chloro and 2-trifluoromethyl with a remote
hydrophobic patch. The essential phenotiazine nucleus can adopt more than one
inhibitory orientation in its binding site. Phenothiazines are promising
trypanocidal agents for the treatment of Chagas' disease. The methodology for
developing new drugs for the treatment of Chagas' disease is discussed.
PMID- 10668259
TI - [Treatment of Trypanosoma cruzi infection in the indeterminate phase: experience
and current guidelines in Argentina].
AB - An effective treatment for Trypanosoma cruzi infection has been investigated,
since the 30s. The goals of the specific treatment against T. cruzi infection
are, at the individual level, to eliminate the parasite, and to reduce the
probability of developing Chagas disease. At the end of the 60s and at the
beginning of the 70s, two compounds were clinically investigated in Argentina:
Nifurtimox and Benznidazole. After the approval by the Ministry of Health, in
1983 the first guidelines for the treatment of T. cruzi infection were proposed
and approved. These guidelines recommended the treatment of cases in the acute
phase. Due to the publication of new information in support of the utility of
these drugs for treating cases in the indeterminate phase of Chagas disease, in
1997 the original guidelines were revised and new procedures were approved. At
present, the treatment is recommended for: 1) all patients undergoing the acute
phase; 2) children and young people undergoing the indeterminate phase; 3) adult
patients undergoing the indeterminate phase or with incipient heart lesions; 4)
laboratory accidents and during surgery, and 5) organ transplant recipients or
donors. The general clinical laboratory control is needed for the intra-treatment
monitoring of the patient. Titration of specific antibodies with monospecific
antigens has been shown to be an adequate marker of therapeutic efficacy.
PMID- 10668260
TI - [Trypanocidal effect of cysteine protease inhibitors in vitro and in vivo in
experimental Chagas disease].
AB - Endemic in most American countries, Chagas' disease causes high morbidity and
mortality. Recent experimental and clinical evidence shows the importance of
chemotherapy in both the acute and chronic phases of this disease. However,
treatment is yet limited by the toxicity associated to available drugs. This
review describes the design, evolution, and selection of dipeptides that
interrupt the intracellular cycle of T. cruzi and cure acute experimental
infections in laboratory animals. Peptido-mimetic inhibitors specifically bind
cruzain, a T. cruzi cystein protease. The inhibitors cause alterations in the
Golgi complex and ER, accumulation of unprocessed enzyme within Golgi cisternae,
and decrease of mature cruzain within lysosomes. The most effective compound, N
Pip-F-hF-VS phi, cured an acute lethal infection in experimental animals.
Myocardial lesions, lymphocyte infiltration and intracellular amastigote clusers
were absent in treated animals. Preliminary toxicology and pharmacokinetic
analyses suggest the lack of toxicity associated to high doses and prolonged
treatment regimes. Protease inhibitors may soon become good chemotherapeutic
alternatives for acute and chronic Chagas' disease.
PMID- 10668261
TI - Polymerase chain reaction (PCR) as a laboratory tool for the evaluation of the
parasitological cure in Chagas disease after specific treatment.
AB - The evaluation of the treatment for chronic Chagas disease faces the absence of
any clear-cut criterion of cure. The low degree of parasitemia and the
persistence of positive immunologic reactions represent some of the difficulties
involved in addressing therapeutic efficacy. Our aim was to define whether PCR
could be used as a laboratory method for evaluating cure in Chagas disease after
specific treatment. We tested the utility of PCR amplification of the variable
regions of minicircles from Trypanosoma cruzi kinetoplast DNA, in 76 xeno
positive chronic Brazilian patients who have been treated with benznidazole in
Mambai (Goias State) and Sao Felipe (Bahia State). We observed a positive
amplification result in only 25 out of 76 treated patients (33%). Therefore, the
performance of one single PCR after therapy revealed parasite clearance in 67% of
the treated individuals, while xenodiagnosis was negative in 84%. These
observations suggest that PCR is the most sensitive technique available for
direct detection of T. cruzi in chagasic patients and that it can be a very
useful instrument for the follow-up of patients after specific chemotherapy. In
this sense, we are now developing a quantitative approach based on the use of
fluorogenic probes and real-time measurement of the amplification reaction
(TaqMan technology) in order to precisely estimate the parasite load in chronic
chagasic patients before and after treatment. This may be the basis for the
future establishment of reliable criteria of cure for patients undergoing
therapy.
PMID- 10668262
TI - Future prospects for the chemotherapy of Chagas' disease.
AB - Over the last two decades, progress towards new drugs for the treatment of
Chagas' disease has been disappointing. However, as a result of the parasite
genome sequencing projects, the possibility of identifying novel drug targets
through genomics, proteomics and bioinformatics has never been better. Progress
towards the development of novel therapeutics, from target identification and
validation by chemical and genetic means through to rational drug design, is
illustrated with reference to the metabolism and functions of trypanothione, with
particular emphasis on trypanothione reductase, one current drug target of
choice.
PMID- 10668263
TI - [Primary glomerulopathies].
PMID- 10668264
TI - [Anatomy of the splenic artery].
AB - Due to the importance and permanent improvements as regards the treatment of
different diseases involving abdominal organs such as the abdomen, pancreas and
spleen. I was indined to investigate, both from the anatomic and surgical point
of view, one of the collateral arterial branches of the celiac trunk, which is
possibly considered to be one the least studied and, historically one of the most
forgotten by the vessels irrigating the liver and stomach. Considering the fact
that anatomic understanding is the starting point of medical knowledge, and that
its conquests give it permanently new fundaments, I was determined to do
research, intensely and thoroughly on splenic artery. This research work relates
in detail, on the corresponding chapters, the material and methods used, which
consist on human bodies and foetus fixed with formol and in a fresh condition.
These human bodies and foetus were submitted to dissection techniques of inter
arterial injection with resin, and then they were corroded with acid and
angiographic studies. Finally selective arteriographic tests were performed on
living beings by means of digitalis removal of the splenic artery. The following
chapter deals with the results obtained from saied research work, showing that
the splenic artery originates, in all cases, from the celiac trunk, and this
artery is the most important with an average length of 10.6 centimeters and of
2.3 flexuosities in all. This chapter also enumerates the relationships existing
between the splenic artery and neighboring organs, the homonymous vein, its
collateral and terminal branches which in the hundred percent of cases showed one
superior and one inferior, to immediately subdivide in different ones at the
level of the splenic pedide. The collateral branches found were the following:
arterial pancreatic branches found in the 73% of the cases with an average of 1.8
arteries in all. posterior esophaguscardiotuberosity artery appearing in a 33% of
the cases. superior polar artery appearing in a 53% of the cases. inferior polar
artery appearing in a 33% of the cases. the short vessels appeared in the 100% of
the cases, from which in a 73% were superior short vessels and in the remaining
27% inferior short vessels. the left gastroepiploon artery appeared in all the
cases considered. I have discussed the anatomic importance of the splenic artery
and gland with their multiple variations and relationships. I have also
considered the splenic pedicle, depending on the rear fixation which has the
extremity of the pancreas and the splenic hillum of 2.2 centimeters, with final
figures ranging from 0 to 4 centimeters. I have also mentioned the appearance of
a 10% of super numerary spleens. Finally in our experience with splenic
segmentation and with corrosion pharmaceutical preparation and arteriographic
studies as the basic ingredients, we have found that in a 62.5% they have two
segments, in a 17% they have three segments, in a 12.5% they have four segments,
in a 12.5% they have four segments and in an 8% they have five segments in all,
in these cases generally due to the high importance of the polar arteries.
Likewise, it is a truth universally accepted that splenic circulation is terminal
and that spleen division into segments is separated by non-vascular levels.
PMID- 10668265
TI - [Comparative structural study of the glial blastomas of the central nervous
system].
AB - The objective of our work is to compare 2 diagnostics methods and demonstrate the
similarities of the different Central Nervous System Glial Tumor Classifications.
Immuno-marking techniques for gliofibrilar acid protein (GFAP), and special
silver impregnations to compare the results according to the last histogenetic
interpretations were used. 95 Gliomas were studied with hematoxiline-eosine and
silver techniques, and in 58 randomized selected cases the technique for GFAP was
also used. Both methods showed the same results in the diagnosis of Glial Tumors
whose cells possess gliofibrils: Glioepitelioma (Ependymoma), Glioblastoma,
Astroblastoma, and Astrocytoma. In the Oligodendrioglomas whose cells possess
microtubules but not gliofibrils, the silver techniques marked these cells and
their prolongations while the technique for GFAP did not. Regarding Gliomas,
there are similarities by comparing the Del Rio Ortega-Polak classification with
those of the WHO and other authors. There are differences only in the "names" of
some tumors or in their histogenetic interpretation, which are not substantial
and are confined to the "Polar Espongioblastoma" and "Gliosarcoma". Therefore, we
think that the recognition of the Del Rio Hortega-Polak classification is
justified.
PMID- 10668266
TI - [Human papillomavirus detection in oral cancer lesions in the city of Cordoba].
AB - Oral cancer is a process that involves different etiological factors and
mechanisms in the light of current view of viral cocarcinogenesis. Evidence from
histology and DNA hybridization studies suggests that HPV is engaged in oral
carcinogenesis. The Pathology Laboratory of the Dentistry School, National
University of Cordoba, admits approximately 20% of all patients with cancerous
lesions in this city. In the January 1992-December 1997 lapse, we examined 1950
biopsies with oral lesions, 4.77% (93/1950) of which were malignant neoplasms,
79.57% (74/93) were oral carcinomas. Thirty-three oral carcinomas (44.6%; 33/74)
were selected at random and included in this study, 33 cells smears of normal
oral mucosa of controls individuals were included. They were analyzed by
conventional light microscopy and an in situ hybridization technique for the
detection of HPV. Data were analyzed with chi square test. The prevalence of HPV
among the 33 cancer samples studied was 27.27%, 9/33 tested positive for HPV in
low stringent conditions. Only one was positive in high stringent condition for
HPV16, a verrugous carcinoma. No HPV-DNA was detected in cells smears of
controls. Among the HPV positive, 3/9 (33.33%) were squamous carcinomas and 5/9
(55.56%) were verrugous carcinomas. Only one was a melanoma. Verrugous carcinoma
was the carcinoma most associated with the HPV infection (x2 = 20.5; 95% level of
confidence). This would indicate a major role of HPV in the pathogenesis of
verrucous carcinomas. The viral prevalence found in cancerous lesions reinforces
the concept of heterogenic natures of oral cancer. HPV is a circumstance that
increase the probability of malignancy, and when reducing, diminish the frequency
of cancer.
PMID- 10668267
TI - [Importance of the benzylpenicillin nucleus and the side chain of the beta
lactams. Demonstration by skin tests and RAST in penicillin allergic patients].
AB - We studied 30 patients with beta-Lactams allergy demonstrated by clinical
findings. The aim of this work was to determine the capacity of the beta-Lactams
nucleus and the side chain in the induction of specific IgE to BPO, Ax, Amp,
performed by intradermal skin test and RAST. The patients were divided by
clinical manifestations in: 1-Accelerated reactions (n:19); and 2-Immediate
reactions (n:11). The Prick tests were performed with BPO-PL, Ax-PL, Amp-PL, MDM
BP, MDM-Ax, MDM-Amp. The accelerated group presented BPO-PL (+) in 2 cases, Ax-PL
& Amp-PL (+) in 4 cases, and all of the reactives were (+) in 13 out of 19 cases.
The immediate group presented MDM-BP (+) in 10 out of 11 cases and MDM-Amp was
(+) in 1 out of 11 cases. The RAST's were performed in all patients(n:30). In
accelerated group were (+) to BPO-PL in 13 out of 19 cases, to Ax-PL in 3 out of
19 cases, to Amp-PL in 1 out 19 cases, to BPO-PL and Ax-PL on overlap in 1 out of
19 cases, and 1 case was negative to all reactives. The immediate group presented
RAST's negatives in 11 out of 11 cases. The control group(n:20) presented Prick
(+) to Ax-PL in 1 out of 20 cases, and the others reactives were negatives in all
cases. The RAST's to all reactives were (-) in 20 out of 20 subjects. These
results indicate that BPO was the most important determinant, and the side chain
of the Ax or Amp were others determinants of the beta-Lactams drugs. These
determinants induced specific IgE, and in rare occasions appears specific IgE for
two different determinants on overlap in the same patient. The intradermal skin
testing is the method of choice to study the penicillin allergies, because non
satisfactory RAST's have yet been developed for minor determinant-specific IgE
antibodies.
PMID- 10668268
TI - [Isolation of Vibrio cholerae non 01 from patients with acute gastroenteritis].
AB - It was assay by biochemical and immunological tests, strains of V. Cholerae non
01 non-0139 isolated from two patients of the province of Cordoba, Argentina.
They showed episodes of acute gastroenteritis. Strains non-01 non-0139 were
isolated from water samples ingested by patients. We conclude that strains
identified from patients would have the source from contaminated environmental
water by V. Cholerae.
PMID- 10668269
TI - [Comparation of the antero-lateral and posterior approaches in primary total hip
arthroplasty].
AB - Comparison between the antero-lateral and posterior approaches in primary total
hip arthroplasty. In this retrospective study, 184 patients were enrolled, 95
submitted to the anterolateral (Watson jones) and 89 to the posterior approach
(Moore) from June 1993 to June 1997. The outcomes assessed were perioperative
data (operative time, hospital stay, time from surgery until hospital discharge,
surgical bleeding and the need for blood transfusion), as well as late
complications (deep venous thrombosis DVP, pulmonary embolism, periopheral nerve
injury, prothesis instability and others). Both groups did not differ in terms of
preoperative parameters. Those submitted to the posterior approach had shorter
operative times (p < 0.001), as well as reduced bleeding (p < 0.05) and need for
blood transfusion (p < 0.001) during surgery. The outcomes, such as late
complications, had similar reduced frequency in both groups. The posterior
approach has been successfully applied in our service and proves to be an
excellent alternative surgical access to the total hip arthroplasty.
PMID- 10668270
TI - [Amplifying right colectomy: place in the treatment of obstructive proximal left
colon cancer].
AB - The results obtained about nineteen (19) patients operated by left colon cancer
with variable grade obstruction have been analysed. Seventeen (17) patients
operated due to obstructive left colon cancer situated: five (5) in distal
transverse colon, other five (5) at splenic flexure and seven (7) in proximal
descending colon but three of them with right synchronic neoplasias. The
remaining two (2) that showed a cancer located at splenic flexure and the other
one in proximal descending colon were reoperated three weeks later than a
transverse colostomy had been performed owing to an obstructive condition. One
patient had to be reoperated because a generalised peritonitis from a fistula
with partial disruption on end to end ileo-colic anastomosis. Exteriorization of
both ends was carried out with favourable evolution and subsequent reanastomosis.
An exteriorized patient by splenic flexure cancer also had to be drained ten days
later for a retroperitoneal abscess through a percutaneous puncture and a lesion
grade 1 in lower pole of spleen was resolved with electrofulguration. No patient
has showed invalidating diarrhea and all themselves have been stabilised with two
or three stools daily about two month after surgery. Amplifying right colectomy
is a safe procedure with low surgical morbimortality and take privileged place in
the treatment of the patients undergoing synchronical neoplasias and/or
carcinomas associated with polyps, specially in all those cases when a variable
grade of obstruction have occurred.
PMID- 10668271
TI - [Pancreaticogastrostomy].
AB - From 1991 we have carried out 19 duodenopancreatectomy and we have reconstructed
with pancreatogastrostomy in 11 opportunities. The mortality was of 0% and the
morbidity reached 52.94%. In this presentation we propose technical sample.
PMID- 10668272
TI - [Value of the nuclear magnetic cholangio resonance in the study of the patient
with jaundice].
AB - This report analyse the results about forty three (43) patients, thirty six (36)
of which showed an extrahepatic obstructive biliary Syndrome was made evident by
ultrasonography, five (5) with a cholecistolithiasis and doubtful history of
jaundice were evaluated to carry out a video-surgery procedure and two (2)
patients whom hepatic-yeyunostomy had been practiced, a control of anastomosis in
postoperative period was required. Nuclear Magnetic Resonance and Operative
Cholangiography findings were correlated and afterward with the
anatomopathological studies when they arrived. In all cases the Nuclear Magnetic
Cholangio Resonance (NMCR) let us prove the diagnosis of extrahepatic biliary
obstruction determining with precision furthermore the topographical site of the
lesion. Respecting the aetiology of obstruction, NMCR was accurate in 34 out of
36 cases (94.4%). In conclusion Cholangio-Resonance is an excellent diagnostic
method to evaluate biliary ductal system including anatomic changes. However,
there are some limitations yet in order to determine the aetiology of lesions
about extrahepatic biliary via extremes. We emphasize its features such as non
invasive, little operating dependent, and without morbimortality that become it
as a method of choice to study the biliary via from a diagnostic viewpoint.
PMID- 10668273
TI - [Restructuring and reorganization project in the public health area].
AB - The objective of this project is to produce substantial change as regards the
reorganization, reconstruction and normalization of the hospital data to extra
hospital data recording system from the Ministry of Health in the Province of
Cordoba (Argentina). In order to incorporate socio-demographic factors in the
various data forms so asa to produce efficiency upon the politic implemented. To
achieve such aim, colwork on the different levels of execution, training the
health team with respect to the identification of the population problems, and
attempting to change of a demographic basis the current sanitary policies into
policies of populations.
PMID- 10668274
TI - [Cervical ectopic thymus].
AB - We present a case of ectopic thymus in an eight month old male baby, with a right
lateral tumor of the neck. Ectopic thymus is a pathology rarely observed, its
embryogenesis could explain its cervical localization. X Ray, ultrasonography,
IRM, esophagoscophy and laryngoscophy may be helpful in the differential
diagnosis with other tumors of the neck. Due to the fact that cystic lesions and
neoplasis developments take place, the chosen treatment is the complete
chirurgical extirpation. But at the absence of symptoms, no treatments is
advisable because eventually the thymus spontaneously involutionates.
PMID- 10668275
TI - Cytokine-like substance: origin and fate in Chagas' disease a new hypothesis
about the local inflammatory reaction etiopathogenesis (experimental study in
white mice)
PMID- 10668276
TI - Orifice Diseases Project--experience of the "Hospital das Clinicas" University of
Sao Paulo Medical Center in day-hospital of anorectal disease.
AB - The treatment of malignant or benign colorectal pathologies that require more
complex management are priorities in tertiary hospitals such as "Hospital das
Clinicas" University of Sao Paulo Medical Center (HCFMUSP). Therefore, benign,
uncomplicated orifice conditions are relegated to second place. The number of
patients with hemorrhoids, perianal fistulas, fissures, condylomas and pilonidal
cysts who seek treatment at the HFMUSP is very great, resulting in over-crowding
in the outpatient clinics and a long waiting list for recommended surgical
treatment (at times over 18 months). The authors describe the experience of the
HCFMUSP over an eight-day period with day-hospital surgery in which 140 patients
underwent surgery. Data was prospectively taken on the patients undergoing
surgery for benign orifice pathologies including age, sex, diagnosis, surgery
performed, immediate and late postoperative complications, and follow-up, 140
patients operated on over eight days were studied, 68 were males (48.75%) with
ages ranging from 25 to 62 (mean 35.2 yrs.). Hemorrhoids was the most frequent
condition encountered (82 hemorrhoidectomies, 58.6%), followed by perineal
fistula (28 fistula repairs, 20.0%). The most common complication was headache
secondary to rachianesthesia occurring in 9 patients (6.4%). One patient (0.7%)
developed bleeding immediately PO that required reoperation. Mean follow-up was
104 days. Day-surgery characterized by quality care and low morbidity is feasible
in tertiary public hospitals, permitting surgery for benign orifice pathologies
on many patients within a short period of time.
PMID- 10668277
TI - Effect of hyperbaric oxygen on the regeneration of experimental crush injuries of
nerves.
AB - Hyperbaric oxygen has been successfully used on treatment of acute ischemic
injuries involving soft tissues and chronic injuries. In nerve crush injuries,
the mechanisms involved are very similar to those found in ischemic injuries.
Consequently, it is logical to hypothesize that hyperbaric oxygen should improve
nerve repair, which is a critical step on functional recovery. In the present
study, we created standard nerve crush injuries on sciatic nerves of rats, which
underwent treatment with hyperbaric oxygen. Results were assessed by functional
evaluation using walking-track analysis. The functional recovery indexes observed
did not differ from control group. We concluded that hyperbaric oxygen therapy,
in the schedule used, had no influence on functional recovery after nerve crush
injuries.
PMID- 10668278
TI - Rheumatic fever: a multicenter study in the state of Sao Paulo. Pediatric
Committee--Sao Paulo Pediatric Rheumatology Society.
AB - Rheumatic fever is still the most commonly seen rheumatic disease in Brazilian
pediatric rheumatology clinics. It remains a significant health problem since
subsequent cardiac sequelae represent one of the most important causes of chronic
heart disease in children. We reviewed the clinical manifestations of rheumatic
fever in 786 patients followed at seven pediatric rheumatology clinics in the
state of Sao Paulo, Brazil. All patients were diagnosed according to revised
Jones' criteria. Regarding major criteria, 396 (50.4%) children exhibited
carditis, 453 (57.6%) polyarthritis, 274 (34.8%) chorea, 13 (1.6%) erythema
marginatum, and 12 (1.5%) subcutaneous nodules. Valvular lesions documented by
echocardiography in the absence of accompanying auscultatory findings were found
in 144 (18.3%) patients. Migratory polyarthritis was observed in 290 (64.0%)
patients with articular involvement. Documented previous streptococcal infection
assessed by serum antistreptolysin (ASO) titers occurred in 531 (67.5%) patients.
Even though prophylaxis with benzathine penicillin was recommended to all
patients, recurrent attacks were observed in 147 (18.7%). We emphasize the high
frequency of chorea, silent carditis and recurrences in our series as well as the
variable clinical presentation of arthritis in rheumatic fever. Multicenter
studies should be encouraged to improve our understanding of the clinical
features of rheumatic diseases in children and adolescents.
PMID- 10668279
TI - Urinary tract infection in full-term newborn infants: value of urine culture by
bag specimen collection.
AB - OBJECTIVE: To evaluate the efficacy of urine culture by bag specimen for the
detection of neonatal urinary tract infection in full-term newborn infants.
Retrospective study (1997) including full-term newborn infants having a positive
urine culture (> 100,000 CFU/ml) by bag specimen collection. The urinary tract
infection diagnosis was confirmed by positive urine culture (suprapubic bladder
aspiration method). The select cases were divided into three groups, according to
newborn infant age at the bag specimen collection: GI (< 48 h, n = 17), GII (48 h
to 7 d, n = 35) and GIII (> 7 d, n = 9). Sixty one full-term newborn infants were
studied (5.1% of total infants). The diagnosis was confirmed on 19/61 (31.1%) of
full-term infants born alive. Distribution among the groups was: GI = 2/17
(11.8%), GII = 10/35 (28.6%), and GIII = 7/9 (77.7%). The most relevant clinical
symptoms were: fever (GI--100%, GII--91.4%) and weight loss (GI--35.3%, GII-
45.7%). Urine culture results for specimens collected by suprapubic aspiration
were: E. coli GI (100%), GII (40%) and GIII (28.6%), E. faecalis GI (30%),
Staphylococcus coagulase-negative GII (20%) and GIII (42.8%), and Staphylococcus
aureus GII (10%). Correlation between positive urine culture collection (bag
specimen method) and urinary tract infection diagnosis, using relative risk
analysis, produced the following results: GI = 0.30 (CI 95% 0.08-1.15), GII =
0.51 (CI 95% 0.25-1.06) and GIII = 3.31 (CI 95% 1.8-6.06). The most frequent
urinary tract infection clinical signs in the first week were fever and weight
loss, while non-specific symptomatology occurred later. E. coli was most frequent
infectious agent, although from the 7th day of life, staphylococcus was noted.
The urine culture (bag specimen method) was effective in detecting urinary tract
infection only after the 7th day of life.
PMID- 10668280
TI - Liver synthesis function in chronic asymptomatic or oligosymptomatic alcoholics:
correlation with other liver tests.
AB - Liver function and its correlation with bilirubin and hepatic enzymes were
evaluated in 30 male chronic asymptomatic or oligosymptomatic alcoholics admitted
into the psychiatric hospital for detoxification and treatment of alcoholism.
Hypoalbuminemia, lowered prothrombin activity, hypotransferrinemia and
hypofibrinogenemia were detected in 32%, 32%, 28%, and 24% of patients,
respectively. Transferrin was elevated in 8%. Greater prevalence of
hyperbilirubinemia was found in patients with lowered prothrombin activity,
hypofibrinogenemia, or hypotransferrinemia. No correlation was found between
serum bilirubin or aminotransferase levels and normal or elevated albumin levels,
time or activity of prothrombin, and fibrinogen levels. Serum alkaline
phosphatase was elevated in normoalbuminemics and gamma-glutamyltransferase in
patients with lowered prothrombin activity. Hypoalbuminemia was associated with
hypofibrinogenemia, hypotransferrinemia with elevated aspartate aminotransferase
or gamma-glutamyltransferase, and hypertransferrinemia with elevation of alanine
aminotransferase. These data indicated the occurrence of hepatic dysfunction due
to liver damage caused directly by alcohol or by alcoholism-associated
nutritional deficiencies.
PMID- 10668281
TI - Congenital hyperthyroidism: autopsy report.
AB - We report the autopsy of a stillborn fetus with congenital hyperthyroidism born
to a mother with untreated Graves' disease, whose cause of death was congestive
heart failure. The major findings concerned the skull, thyroid, heart, and
placenta. The cranial sutures were closed, with overlapping skull bones. The
thyroid was increased in volume and had intense blood congestion. Histological
examination showed hyperactive follicles. The heart was enlarged and softened,
with dilated cavities and hemorrhagic suffusions in the epicardium. The placenta
had infarctions that involved at least 20% of its surface, and the vessels of the
umbilical cord were fully exposed due to a decrease in Wharton's jelly.
Hyperthyroidism was confirmed by the maternal clinical data, the fetal findings
of exophthalmia, craniosynostosis, and goiter with signs of follicular
hyperactivity. Craniosynostosis is caused by the anabolic action of thyroid
hormones in bone formation during the initial stages of development. The delayed
initiation of treatment in the present case contributed to the severity of fetal
hyperthyroidism and consequent fetal death.
PMID- 10668282
TI - [Acute myocardial infarction: the evolving knowledge about the disease].
AB - Important advances in the knowledge of pathophysiology and management of acute
myocardial infarction have occurred lately. The results of large multicentric
randomized trials allowed the introduction of new diagnostic techniques, patient
stratification tools, drugs and treatment strategies to clinical practice. As a
result, a significant reduction in mortality has been achieved. However there is
a great variation in the adoption of the new diagnostic and therapeutic
recommendations in different countries. In this issue of Revista Medica de Chile,
a registry of patients with acute myocardial infarction treated in Chile between
1993 and 1995, is reported. The mean age of patients (62 +/- 12 years old), the
proportion of males (74%) and the prevalence of risk factors is similar to that
reported in series from developed countries. Similarly, 33% of patients received
thrombolytic therapy, and the pattern of drug use was comparable. The 13.4%
global mortality can be improved. An early consultation to health services when
an acute myocardial infarction is suspected should be encouraged in the
population. Likewise, treatment norms for health institutions should be devised.
PMID- 10668283
TI - [Acute myocardial infarction in Chilean hospitals. Final results of the GEMI
study].
AB - BACKGROUND: Acute myocardial infarction is the leading cause of death in Chile.
AIM: To report the main features, hospital evolution, complications and
pharmacological treatment of patients admitted to Chilean hospitals with the
diagnosis of acute myocardial infarction. PATIENTS AND METHODS: Between 1993 and
1995, the GEMI group registered 2,957 patients admitted to 37 hospitals with the
diagnosis of acute myocardial infarction. RESULTS: Mean age of patients was 62 +/
2 years old and 74% were male. Forty six percent had a history of hypertension
and 40% were smokers. During the first five days of admission, 93% of patients
received aspirin, 95% received intravenous nitrates, 59% intravenous heparin, 56%
oral nitrates, 37% beta blockers, 32% angiotensin-converting enzyme inhibitors,
33% thrombolytic agents, 29% antiarrhythmics and 23% calcium antagonists.
Coronary angiograms were performed in 28% of patients, angioplasty in 9% and 8%
were subjected to a coronary bypass. Global hospital mortality was 13.4% (19.5%
in women and 11.1% in men, p < 0.001). CONCLUSIONS: This work gives a picture of
myocardial infarction in Chilean hospitals. Pharmacological treatment is similar
to that used abroad, but certainly it can be optimized.
PMID- 10668284
TI - [Immunoglobulin rearrangement in the differential diagnosis of primary gastric
lymphoma].
AB - BACKGROUND: The traditional methods to distinguish Chronic Follicular Gastritis
and Primary Gastric Lymphoma do not allow an adequate definitive diagnosis in a
significant number of cases. The molecular Biology diagnostic methods are based
on the rearrangement of immunoglobulin genes. The polymerase chain reaction (PCR)
specifically amplifies this rearrangement and allows molecular analysis of
minimal tissue samples obtained with endoscopical biopsies. AIM: To test the
usefulness of this PCR method in the differential diagnosis between Chronic
Follicular Gastritis and Primary Gastric Lymphoma. MATERIAL AND METHODS: We
analyzed the endoscopical biopsies of six Chronic Follicular Gastritis cases and
eight surgically treated Primary Gastric Lymphoma cases, six with the correct
diagnosis in the endoscopical biopsies and two with a diagnosis of Chronic
Follicular Gastritis. RESULTS: A policlonal immunoglobulin rearrangement was
found in the six cases with Chronic Follicular Gastritis. A monoclonal
arrangement was found in 5 of 6 biopsies with the diagnosis of Primary Gastric
Lymphoma. The same monoclonal rearrangement was observed in the two biopsies
incorrectly diagnosed as Chronic Follicular Gastritis. CONCLUSIONS: PCR analysis
of immunoglobulin rearrangement is a useful method in the differential diagnosis
between Chronic Follicular Gastritis and Primary Gastric Lymphoma.
PMID- 10668285
TI - [Use of a simple polymerase chain reaction combined with a heteroduplex mobility
assay to characterize the non coding 5' region of hepatitis C virus].
AB - BACKGROUND: One of the most used methods for the characterization of hepatitis C
virus strains is the use of a nested polymerase chain reaction (PCR) with a
restriction fragment length polymorphism (RFLP) assay. Sometimes, RFLP results do
not differentiate new strains. There are other more complex methods and only the
sequencing of the PCR fragment allows a correct characterization of the strain.
AIM: To report the detection of hepatitis C virus using a single PCR assay of the
5' non codifying region. MATERIAL AND METHODS: Thirty five serum samples coming
from patients with chronic hepatitis or blood donors were assayed for hepatitis C
virus. RESULTS: The reported method increases the PCR sensitivity through the
combination of polyacrylamide gel electrophoresis and silver staining of
amplified products. This allowed the semi quantitative estimation of viral load
and the characterization of amplified products through their electrophoretic
motility. These PCR products were used in a heteroduplex motility assay; allowing
the discrimination between sequences of different genotypes. CONCLUSIONS:
Heteroduplex assays can be used to characterize the 5' non codifying region of
the hepatitis C virus for routine laboratory purposes.
PMID- 10668286
TI - [Television publicity and food preferences of school age children of the
metropolitan region].
AB - BACKGROUND: There is an alarming increase in the prevalence of child obesity in
Chile. Lack of exercise and bad feeding habits strongly strongly contribute to
the problem. AIM: To investigate the influence of television publicity on school
age children food preferences. MATERIAL AND METHODS: A semi structured interview
was applied to a representative sample of 786 school age children aged 6 to 11
years old, living in Metropolitan Santiago. Time watching television during week
days and the attitude towards food and beverage commercials was analyzed and
related to food preferences. RESULTS: Ninety nine percent of school age children
watch television during week days and 20% watches more the three hours daily.
Snack commercials such as those about potato chips, chocolates, cookies and ice
cream, are preferred by 35% of children. Soda commercials are preferred by 33%
and yoghurt commercials by 12%. Eighty five percent of children had money to buy
food. Of these, 66% bought snacks, 15% bought sodas and 7% yoghurt. The same
tendency was observed in school collations. CONCLUSIONS: The high percentage of
children, watching television and the influence of commercials in their food
preferences, requires an urgent educational strategy to promote healthy feeding
habits.
PMID- 10668287
TI - [High prevalence of undiagnosed primary hyperaldosteronism among patients with
essential hypertension].
AB - BACKGROUND: Classically, primary hyperaldosteronism was diagnosed in no more than
1% of patients with hypertension, when hypokalemia was used as the screening
test. However, numerous patients with primary hyperaldosteronism do not have
hypokalemia and the disease remains undiagnosed. AIM: To assess the prevalence of
normokalemic primary hyperaldosteronism among patients classified as having
essential hypertension. PATIENTS AND METHODS: One hundred hypertensive patients
with a blood pressure over 145/95 were studied. Plasma aldosterone and plasma
renin activity were measured in all. A primary hyperaldosteronism was diagnosed
when high aldosterone levels (over 16 ng/dl) and low plasma renin activity (below
0.5 ng/ml/h) coexisted in two blood tests or the aldosterone/plasma renin
activity ratio was over 50. A probable primary hyperaldosteronism was diagnosed
when the ratio was between 25 and 50 and these patients were subjected to a
Fludrocortisone test to confirm the diagnosis. A dexametasone suppression test
was done to discard glucocorticoid remediable aldosteronism. An adrenal TAC scan
was done to all patients with primary hyperaldosteronism. RESULTS: A diagnosis of
primary hyperaldosteronism was reached in ten patients. Seven had elevated
aldosterone and low plasma renin activity. In three the diagnosis was confirmed
with the fludrocortisone test. All ten patients had normal serum potassium
levels. Dexametasone suppression test was positive in three patients, that
normalized their blood pressure levels. Adrenal TAC scans showed an adenoma in
one patient and hyperplasia in another. CONCLUSIONS: Primary hyperaldosteronism
is more frequent than previously thought, it is overlooked when hypokalemia is
used as the screening test and it can only be diagnosed measuring plasma
aldosterone and renin activity.
PMID- 10668288
TI - [Usefulness of the measurement of insulin-like growth factor (IGF-I) and IGF-1
binding protein-3 (IGFBP-3) for the diagnosis of growth hormone (GH) deficiency
in children].
AB - BACKGROUND: The diagnosis of GH deficiency (GHD) is based upon the results of GH
stimulation tests, which have several drawbacks. AIM: To evaluate the usefulness
of IGF-1 and IGFBP-3 for the diagnosis of GHD in prepuberal children. MATERIAL
AND METHODS: We measured IGF-I and IGFBP-3 in three group of subjects: I. GHD (n:
24), height < -2SD for age (Z score, average +/- SD: -4.2 +/- 1.2), growth
velocity < p10 (3.4 +/- 1.0 cm/year) and peak GH level on two GH stimulation
tests < 7 ng/ml (1.2 +/- 0.6 ng/ml); II. Short non-GHD (NGHD, n: 32), height of
2.7 +/- 0.9 SD for age, growth velocity < p 25 (3.9 +/- 1.2 cm/year), and peak GH
level on two GH stimulation tests > 7 ng/ml (15.3 +/- 6.9 ng/ml), y III. Normal
school children (n: 35) with normal heights (-0.17 +/- 0.12 SD) were studied as
controls. RESULTS: IGF-1 and IGFBP-3 were significantly lower in GHD than in NGHD
and controls (p < 0.001), and in NGHD than in C (p < 0.001). We defined the
normal range of both proteins as +/- 2 SD of the mean of the control group. Using
this criteria, IGF-I was low in 21/24 GHD, and in 12/32 NGHD. IGFBP-3 was low in
22/24 GHD, and in 6/32 NGHD. Only 1 GHD patient had both exams in the normal
range, suggesting that he is probably NGHD. 4/32 of the NGHD and both exams below
normal range, suggesting that they are probably GHD. CONCLUSIONS: IGF-1 and IGFBP
3 are important tools for the diagnosis of GHD.
PMID- 10668289
TI - [Intravenous tissue plasminogen activator in the treatment of acute ischemic
stroke: feasibility, safety, and efficiency in the 2 first years of the clinical
practice].
AB - BACKGROUND: The only effective therapy for the treatment of acute ischemic stroke
is the infusion of tissue plasminogen activator in the first three hours after
the onset of symptoms. AIM: To report the experience with tissue plasminogen
activator infusion in the treatment of acute ischemic stroke. PATIENTS AND
METHODS: Ten males and 10 females, aged 52 to 85 years old with an acute ischemic
stroke, admitted within 89 min after the onset of symptoms were studied. Tissue
plasminogen activator was infused following the guidelines designed by the
National Institute of Neurological Disorders and Stroke (NINDS). Patients were
assessed according to Rankin scale after three months of follow up. RESULTS: All
patients had normal CAT scans. The delay between the onset of symptoms and the
infusion ranged from 75 to 180 min. One patient had a gastrointestinal bleeding
due to a gastric ulcer and one patient had a fatal intracranial hemorrhage. After
three months of follow up, 38% of patients had a good recuperation (Rankin 0 to
1), 33% had a mild to moderate disability (Rankin 2 or 3) and 14% had a moderate
to severe disability (Rankin 4). There was a 15% mortality. CONCLUSIONS: This
series show that treatment of acute ischemic stroke with tissue plasminogen
activator is feasible and safe. The obtained results are similar to those
reported abroad.
PMID- 10668290
TI - [Hurthle cell carcinoma of the thyroid. A 41 years experience].
AB - BACKGROUND: Hurthle cells can be found in non malignant thyroidal diseases such
as Basedow Graves and Hashimoto diseases. When Hurthle cells comprise more the
75% of cellularity, they become a neoplasm. There are malignant variants of these
neoplasms, constituted by follicular and papillary Hurthle cell carcinomas. AIM:
To report a 41 years experience with Hurthle cell carcinomas of the thyroid.
MATERIAL AND METHODS: A retrospective review of all patients operated for a
thyroid carcinoma and selection of those patients with Hurthle cell carcinoma of
the thyroid. RESULTS: Twenty two patients (21 female, mean age 48 years old) with
Hurthle cell carcinoma of the thyroid were selected. Total or near total
thyroidectomy was the treatment of choice in 20 and 19 received 131I. Metastatic
involvement of cervical lymph nodes was found in five patients and they underwent
modified cervical lymph node dissection. During follow up, only one patient died
of the disease. We did not find higher incidences of local recurrences, distant
metastases or mortality rates, compared to well differentiated thyroid
carcinomas. CONCLUSIONS: Hurthle cell carcinomas of the thyroid and well
differentiated thyroid carcinomas have similar biological behaviors. Their
treatment should be similar, including total or near total thyroidectomy plus
modified cervical node dissection when there is lymph node involvement.
Radioactive iodine therapy and suppressive levothyroxin therapy should follow.
PMID- 10668291
TI - [Amiodarone induced retrobulbar neuritis. Clinical case].
AB - We report a 66 years old male, with an ophtalmologic history of long sightedness,
admitted to the hospital due to paroxysmal atrial fibrillation crises in the
context of a coronary heart disease. He was treated with i.v. amiodarone,
receiving a total dose of 6 g in 72 hours. After the third day of treatment, the
patient noticed a correction of his long sightedness and 24 h later, he
complained of hlurred vision and orbital frontal headache. Visual field
examination revealed a concentric retraction of visual field and a centrocecal
scotoma in both eyes. Amiodarone was withdrawn and dexametasone treatment was
begun. Three days after amiodarone discontinuation, sight improved and visual
field returned to normal. Although retrobulbar neuritis has been associated to
various drugs, amiodarone has not been considered as a possible agent.
PMID- 10668292
TI - [Chronic atrial flutter: an infrequent manifestation of sick sinus syndrome.
Clinical case].
AB - We report a 41 years old female, previously operated of an atrial septal defect,
presenting with a persisting atrial flutter. Sinus node dysfunction became
evident during an electrophysiological study at the moment of interrupting the
flutter with electrical stimulation. The patient was treated with his bundle
ablation and implantation of a definitive pacemaker. After one year of follow up,
she is devoid of symptoms.
PMID- 10668293
TI - [Sertoli-Leydig tumor. Clinical case].
AB - We report a 16 year old girl presenting with secondary amenorrhea, a history of
voice coarsening, hirsutism and a body mass index of 35 kg/m2. Pelvic ultrasound
and CT scans showed a retro uterine dense mass. She was operated and a left
ovarian tumor was excised. Pathological examination disclosed a Sertoli-Leydig
tumor.
PMID- 10668294
TI - [Molecular biology and medicine: basic concepts].
AB - Through the advancements of molecular genetics, physicians and researchers are in
an extraordinary period of study concerning the molecular basis of medicine.
Molecular biology is making a tremendous impact on both diagnosis and treatment
of diseases through the clinical introduction of molecular methods. These
techniques, restricted for many years to basic biological research, include the
polymerase chain reaction, DNA and protein electrophoresis, cloning of genes into
viral or bacterial vectors and methods to rapidly sequence DNA and identify
mutations. In this article the authors attempt to provide basic concepts on these
themes for the non-trained physicians in order to help them to understand recent
developments and foresee their future implications.
PMID- 10668296
TI - [Efficacy indicators for the allocation of health resources].
AB - This review proposes an analytical method for the development of efficacy
indicators, that will allow the integration of diverse technical criteria in the
allocation of health resources. Indicators of epidemiological, clinical,
organizational and economic efficiency were the four levels of conceptual
approach integrated in the analytical framework. The different elements of each
level are interrelated to compose an analytical perspective that can be used to
guide the mechanisms of resource allocation based on technical criteria. This
perspective allows the development of new relevant public health instruments,
specially designed for the allocation of resources.
PMID- 10668295
TI - [Adequacy of continuous ambulatory peritoneal dialysis in children].
AB - When the use of dialytical therapy is decided after a careful assessment of
clinical and laboratory variables, the close supervision of the procedure, that
allows a feedback between our indications and its clinical efficacy, is
essential. The correct and routine use of validated adequacy tools such as Kt/V
and the Peritoneal Equilibration Test (PET) is mandatory. We compare the adequacy
figures for adult and pediatric populations, mentioning the Kt/V and PET values
obtained in eight patients followed during 12 months in a Nephrology Unit. An
initial Kt/V of 2.04 and of 2.14 after 12 months of procedure are values that
adjust to the general recommendations discussed in this paper. According to PET
results, this group of patients were classified as low average for
ultrafiltration and high average for creatinine clearance. Based on the local
experience and literature review, some recommendations are made for the
management of peritoneal dialysis in children.
PMID- 10668297
TI - [A medical history of Bernardo O'Higgins (1778-1842)].
AB - Bernardo O'Higgins was a very apprehensive individual regarding his health and
ailments. This fact is clearly reflected in his letters, that provide valuable
anamnestic data. During his youth, while living is Spain, he suffered of yellow
fever and later in Chile, he probably had an acute phase of a rheumatic fever.
Since his adolescence, he was affected by a chronic hlepharo-conjunctivitis.
During the Chilean independence revolution, he suffered several battle wounds.
The most severe was a shot that affected both his right arm and elbow (1818).
While living in Peru (1823-1842) he suffered of dysentery and malaria. The latter
was an endemic disease in the valleys of Peru. Being previously asymptomatic, he
started experiencing extensional dyspnea, angor pectoris and syncopal episodes in
1840. At that time, physicians diagnosed a hypertrophic cardiomyopathy. Analyzing
his symptoms and taking into account their short term evolution, the author
concludes that they were a consequence of either an aortic stenosis or coronary
insufficiency. These led him to a heart failure that was his immediate cause of
death in 1842.
PMID- 10668298
TI - [Organ transplantation in Chile].
PMID- 10668299
TI - Claudio Costa-Casaretto MD. (1914-1999)
PMID- 10668300
TI - An empirical evaluation of the visual rightness theory of pictorial composition.
AB - This research tested the visual rightness theory of pictorial composition's
assertion that the induced organizational structure of a visually right (i.e.,
"good") design is perceptually salient and judged superior by anyone viewing it
regardless of his or her training in the visual arts. Stimuli for Experiments 1
and 2 consisted of 16 reproductions of paintings by renowned artists and an
experimentally reconstructed less-well-organized version of each art stimulus. It
was found that design professionals (Experiment 2) were significantly more
successful at detecting the original versions than were participants untrained in
the visual arts (Experiment 1) (hit rates = 64% and 55%, respectively). In
Experiment 3 participants replaced a major structural element removed from each
of six pictures of the stimulus set at the location where they thought it appears
in the original. A significant number of untrained participants and those with
training in design theory were in agreement as to the location of each element
within its pictorial field; the location chosen conformed to its compositional
structure but not its actual location in the original. Findings demonstrate that
the ability to detect the induced structural skeleton of a painting resulting
from a visually right design does not require expert knowledge of design
principles whereas the ability to discriminate between several articulation
possibilities of the same composition does require formal training.
PMID- 10668301
TI - Allocating attention in the visual field: the effects of cue type and target
distractor confusability.
AB - In the present study I compared the effect of colour and location cues on the
selection of a target. Two questions were in focus. First, can both colour and
location cues trigger and mediate attentional selection, and if they can, which
of them is more effective? Second, does physical distinctiveness between a target
and a distractor have to be taken into account? In two experiments, in which the
most likely target colour or location was cued, both colour cues and arrow-like
location cues produced cue-validity effects. The relative effectiveness of
feature cues and location cues appeared, to some extent, to be dependent on
target-distractor confusability. Taken together, the results support the post
categorical filter theory, in which different cues can be used to trigger the
feedback loop that is used to address relevant identity information via location.
PMID- 10668302
TI - Response repetition benefits and costs.
AB - In a wide variety of tasks, choice reaction time (RT) is reduced for repetitions
of the previous response. However, when the task itself or a relevant physical
feature that successive trials have in common changes, costs for response
repetitions can be observed. In a series of three experiments it was investigated
whether the repetition of a response results in costs if the stimulus category
changes. Furthermore, it was asked whether there need to be informative physical
task features that successive trials have in common to produce response
repetition costs. In alternating runs, participants had to respond to either one
of four symbols or one of the letters with a binary choice reaction: Results
suggest that a change of stimulus category is a sufficient condition to produce
response repetition costs. It is hypothesized that any change of a task feature
that is part of the task representation participants adopt leads to a disruption
of repetition-based facilitation and tends to facilitate a response alternation.
PMID- 10668303
TI - The effects of eccentric head positions on leftward and rightward turns of a
handle-bar.
AB - We explored the structural constraints on concurrent movements and/or positions
of the head and a steering device by means of a reaction-time task. In the first
experiment, subjects had to respond rapidly to an imperative stimulus by way of
rotating a handle-bar to the left or to the right and back to the central
position while they maintained a left or right eccentric position of the head.
Latency of the handle-bar responses did not depend on whether their initial
directions were toward the eccentric head position or in the opposite direction,
but kinematic characteristics did: iso-directional movements were of larger
amplitude and longer duration until peak excursion. In the second experiment, the
imperative stimuli for handle-bar rotations were presented at variable intervals
after the head had been moved from the central to one of the eccentric positions
and before its predictable return movement. Kinematic characteristics of the
handle-bar rotations depended on the left and right eccentric head positions in
the same way as in Experiment 1, but now iso-directional movements had a longer
reaction time than movements in the direction of the forthcoming return movement
of the head. These findings suggest that specifications of head-movement
directions facilitate concurrent specifications of handle-bar rotations in the
same direction and inhibit specifications of handle-bar rotations in the opposite
direction, consistent with the notion of cross-talk during motor programming.
PMID- 10668304
TI - Psychopathological aspects of cryptorchidism in children and adolescents.
AB - In the male sexual and aggressive drives are mostly centered on the penis, whose
real or fantasied features strongly affect the way children and adolescents build
up their own personal and gender identity. In some clinical conditions a shift of
genital centrality from penis to testicles is evident. The most frequent is
abnormality in the descent of testicles, especially cryptorchidism, characterized
by an arrested descent of one or two testicles that remain in the abdomen. The
aim of this paper is to define mechanisms by which cryptorchidism increases
psychological vulnerability. Time of diagnosis and treatment, restoration of
genital integrity, personality stability and familial interactions are considered
as elements affecting psychopathological outcome. Behavioral and psychological
features in children and adolescents with cryptorchidism are reviewed. A case
report of an adolescent with unilateral cryptorchidism is reported and discussed,
as an example of pubertal distortion in bodily and gender identity.
PMID- 10668305
TI - Clinical and developmental perspectives on adolescent coping.
AB - Although the development of appropriate coping strategies has been understood as
an essential element of healthy adjustment, few studies have demonstrated the
link between coping and psychological development. Similarly, research on
adolescents with behavioral problems has neglected coping as an important
variable in understanding and treating these conditions. This study examines the
relationships between psychological development, coping strategies and symptoms
in a sample of 302 psychiatrically hospitalized adolescents, ages 12-16. Subjects
completed the Adolescent Coping Orientation for Problem Strategies Questionnaire,
(A-COPE), the Youth Self Report symptom checklist (YSR), and Loevinger's measure
of ego development. Results showed that Avoidance and Ventilation were associated
with increased behavior problems and lower levels of ego development. Problem
solving and interpersonal strategies were associated with fewer symptoms and
higher levels of development. Significant gender differences were found with
girls using more interpersonal coping and boys using more physically active
strategies. Gender differences were also found in the relationship of coping
strategies to both symptomatic behavior and development. The results are
discussed in the context of a developmental approach to adolescent
psychopathology.
PMID- 10668306
TI - Medication noncompliance in adolescents with psychiatric disorders.
AB - The purpose of the study was to estimate prevalence of medication noncompliance
among adolescents, following discharge from hospital. A second purpose was to
identify predictors of such noncompliance. Seventy-one adolescents, who had been
prescribed a medication during psychiatric hospitalization, were interviewed by
telephone, 6-8 months post-hospitalization. Medication noncompliance was defined
as discontinuing medication without the recommendation of the treating physician.
Twenty-four subjects (33.8%) were noncompliant with medication. Age, race,
gender, SES, diagnosis, type and number of medications, severity of depression,
and family living arrangement did not predict noncompliance. We concluded that
noncompliance with psychotropic medications was relatively common and difficult
to predict in adolescents who had been hospitalized to a psychiatric inpatient
unit; the majority of them suffered from depression. Clinicians should be aware
that medication noncompliance may be common and a relatively unpredictable
phenomenon.
PMID- 10668307
TI - One-year-old infants of intrusive and withdrawn depressed mothers.
AB - This study examined behaviors of intrusive/depressed versus withdrawn/depressed
mothers and their one-year-old infants during a structured teaching interaction.
Group comparisons revealed that intrusive/depressed mothers showed more positive
responses, more demonstrating toys, and more physical guidance, and their infants
demonstrated less toy manipulation. Withdrawn/depressed mothers maintained infant
play more frequently and showed more restricted affect, and their infants
demonstrated less affective behavior, both positive and negative. These findings
suggested that exposure to depressed mothers' nonoptimal interaction styles
represents different types of risk to infants' cognitive and affective
development.
PMID- 10668308
TI - Relations among child language skills, maternal socialization of emotion
regulation, and child behavior problems.
AB - Research has linked language delays in young children to behavior problems and
risk for psychopathology. We hypothesized that low language skill would affect
normal socialization of emotion regulation, which in turn would affect the
development of behavior problems. Seventy-eight mother/preschool-age child pairs
participated in two mildly frustrating situations. Parents of children with low
verbal comprehension used more unexplained compliance demands than other parents.
Further, children whose parents used more unexplained compliance demands used
fewer cognitive and distraction strategies, and more instrumental strategies.
Children's use of physical self-comforting was positively related to overall,
internalizing, and externalizing behavior problems. Findings supported the
original hypothesis.
PMID- 10668309
TI - ECG of the month. Reading T leaves. Acute ischemic cardiac syndrome.
PMID- 10668310
TI - Recurrent aphthous stomatitis.
AB - Recurrent aphthous stomatitis is the most common oral mucosal disease in North
America but it is commonly misdiagnosed and poorly understood. Pediatricians,
internists, otolaryngologists, oral surgeons, and dentists may all be expected to
treat this illness but little formal training in oral medicine may be offered to
many of these health care professionals. This article reviews current evidence
regarding etiology, pathogenesis, natural history, and treatment of this
disorder.
PMID- 10668311
TI - Radiology case of the month. Right upper quadrant pain and palpable mass.
Hemangioma of the liver.
PMID- 10668312
TI - The journal 150 & 100 years ago. January 1850 and 1900.
PMID- 10668313
TI - How can genetics help in the management of obesity?
AB - Obesity usually results from unwanted variations in metabolism. Inadequate
neurotransmission, thermogenesis, or acylation underlie about 90% of cases. These
are complex, weakly heritable, polygenic traits. Mutations in major gene loci
cause another 5% of cases, and still another 5% of cases are due to gluttony.
Careful observation can help define the type of obesity. All forms are associated
with excess mortality and require lifelong episodic or continuous management.
Management centers around diet, exercise, behavior therapy, and life-style
counseling. Serotonin agonists and serotonin uptake inhibitors, as well as
alternative therapies like phototherapy and 5-hydroxytryptophan are worthwhile
for neurotransmitter inadequacy, except in children and pregnant women. When
thermogenesis is inadequate, intake may be normal and weight reduction may
require subnormal intake. Some degree of obesity may be required for optimal
health in patients with inadequate acylation. In some Mendelian syndromes,
obesity may balance a metabolic error, and weight reduction may restore metabolic
imbalance.
PMID- 10668314
TI - Dandy-Walker syndrome: presentation of the congenital malformation in an older
patient.
AB - Dandy-Walker syndrome, a congenital malformation of the hindbrain involving the
cerebellum and the fourth ventricle, is a rare cranial abnormality that commonly
occurs before the sixth or seventh week of development. It is usually diagnosed
at birth or in early childhood; however, an occasional patient may first become
symptomatic in adult life. A case of Dandy-Walker syndrome in a 58-year-old woman
is reported because of the older age at presentation and relatively long
asymptomatic period after birth.
PMID- 10668315
TI - Lafayette's Family Practice Residency Program: practice patterns of graduates.
PMID- 10668316
TI - Quadriceps sparing myopathy.
AB - Magnetic resonance imaging (MRI) has been proven to be a useful tool in the
evaluation of myopathy. Myopathic changes secondary to processes such as
inflammatory disease, neuropathy, and neuromuscular disorders often involve
several muscle groups. We describe a unique case of lower extremity myopathy with
sparing of the quadriceps muscle group on MRI evaluation.
PMID- 10668317
TI - [New discoveries on Alzheimer disease: new biochemical markers can hopefully
improve diagnosis].
PMID- 10668318
TI - [Physicians and the spirit of the time 1930-1950. Situation on the labour market
was the reason for prohibition of the import of physicians].
PMID- 10668319
TI - [Irrelevant about the risks of ocular laser interventions].
PMID- 10668320
TI - [Treatment of hepatitis C--recommendations by the specialty association are still
valid].
PMID- 10668322
TI - [Private practitioners are not allowed to ask for the assistance of police].
PMID- 10668321
TI - [Clinical bacteriology and clinical virology are important parts of basic health
care!].
PMID- 10668323
TI - [Toxic amblyopia and vitamin B12].
PMID- 10668324
TI - [Human blood is still the best for transfusion. But intensive research is going
on to find substitutes].
PMID- 10668325
TI - [Future treatment of rheumatism. A compromise in the game between inflammation
and infections].
PMID- 10668326
TI - [Reduced number of citizens per general practitioner. Increased support from the
society to family practice in future].
PMID- 10668327
TI - [Goethe about medicine and his diseases: Yes, the soul of medicine is simple to
understand. Laws of the great and the little world are studied--than everything
is in the God's hands].
PMID- 10668328
TI - [Ancient medicine is based on nature philosophy. Alkmaion and Empedokles,
philosophers and physicians seeking natural explanations].
PMID- 10668329
TI - [A project on "Hazardous use of alcohol". Patients receive a basis for their
decisions concerning their alcohol habits].
PMID- 10668330
TI - [We manage better without nitrous oxide].
PMID- 10668331
TI - [Enough acid rain over psychiatry! The psychiatric society on the debate about
psychiatry].
PMID- 10668332
TI - [The good psychiatric "asylums" as cleaning women of society].
PMID- 10668333
TI - [Projective tests and evaluations based on the psychodynamic theory are not
reliable].
PMID- 10668334
TI - [A comment: better standard data are required. No resources for research].
PMID- 10668335
TI - [The histologist and anatomist Gustaf Retzius. He never received the Nobel Prize
in spite of his twelve nominations].
PMID- 10668336
TI - [Mystery of the disappeared picture].
PMID- 10668337
TI - [A medical student of exactly 100 years ago. Battlefields and war prisoners'
camps were his surgeries].
PMID- 10668339
TI - [Effect of exercise tolerance test on hemostasis in patients with and without
coronary heart disease].
AB - BACKGROUND: Physical exercise leads to an elevated coagulation activity with a
possibly disturbed hemostatic balance. Therefore patients with coronary heart
disease have a potentially increased risk of thromboembolic events after a
bicycle exercise tolerance test, that is frequently performed for diagnostic
reasons. PATIENTS AND METHODS: Patients with angiographically known coronary
heart disease (Group I: n = 49; age 59 years; male = 42, female = 7) were
investigated in comparison to a healthy cohort (Group 2: n = 51; age 53 years;
male = 44, female = 7) to study the influence of a standardized exercise
tolerance test on hemostatic variables. Blood samples were taken before and after
exercise. RESULTS: No significant changes were found for any investigated
parameter between both groups. However, 3 parameters did change significantly
within the groups: factor VIII rose in Group 1 from 132 to 156% and in Group 2
from 106 to 136% and the von Willebrand factor rose in Group 1 from 230 to 249%
and in Group 2 from 228 to 247%. An elevated fibrinolytic potential was found
with an increase of plasminogen-alpha 2-antiplasmin in Group 1 from 251 to 401
micrograms/l and in Group 2 from 247 to 350 micrograms/l. CONCLUSION: The
findings underline the clinical presumption that exercise tolerance test does not
increase the risk for thromboembolic complications in patients with coronary
heart disease in comparison to patients without coronary heart disease, as long
as the exercise tolerance test is performed in a standardized way and under
aerobe conditions.
PMID- 10668338
TI - [Economic evaluation of different treatment strategies in patients with stable
angina pectoris or asymptomatic myocardial ischemia on basis of results from the
Asymptomatic-Cardiac-Ischemia Pilot study (ACIP)].
AB - BACKGROUND: In patients with stable angina pectoris or silent myocardial
ischemia, who had signs of ischemia in ECG during exercise, the Asymptomatic
Cardiac Ischemia Pilot (ACIP) study compared 2 types of medication strategies
(ischemia-guided and angina-guided) and a strategy of primary revascularization
by PTCA or CABG. ACIP substantiated, after 2 years of observation, a clear
advantage of the revascularization strategy compared to both drug strategies in
terms of clinical effectiveness. This advantage is even more distinct in patients
with very severe angiographic results. PATIENTS AND METHODS: This is a
retrospective, incremental cost-effectiveness analysis from the perspective of
the German third party payer (statutory sick funds) on the basis of the ACIP
study. RESULTS: The direct costs of the revascularization strategy after 2 years
are about 2 to 3 times higher than those of the drug therapies. The incremental
cost-effectiveness of the ischemia-guided strategy versus an angina-guided
strategy is DM 2,600 per life-year saved. Furthermore, the cost-effectiveness of
a revascularization strategy versus an angina guided therapy is DM 15,100 per
life-year saved. CONCLUSION: A primary revascularization strategy is cost
effective in patients with stable coronary artery disease with proven myocardial
ischemia and positive angiographic signs.
PMID- 10668340
TI - [Drug therapy of endocrine neoplasms. Part I: Thyroid neoplasms, adrenal
neoplasms and parathyroid neoplasms].
AB - BACKGROUND: The incidence of endocrine carcinomas is about 5.3 persons per
100,000 population. Most frequent are malignancies of the thyroid gland (about
89%). THERAPY: Because of low incidences and missing prospective studies as well
as radiotherapy and chemotherapy resistance, general accepted therapy guidelines
for endocrine carcinomas are still missing. Surgery and radionucleotide treatment
is generally the first-line therapy. Hormonal active carcinomas can be
additionally treated with special substances such as octreotide and mitotane.
Chemotherapy is frequently not effective. Widely used substances are
cyclophosphamide, cisplatin, doxorubicine, dacarbazine, vincristine and
etoposide. This first part of the review will present medical therapies of
thyroid carcinomas, adrenal carcinomas and parathyroid carcinomas. The second
part in one of the next issues will focus on less frequent endocrine carcinomas
of the gastrointestinal tract.
PMID- 10668341
TI - [Original brands and generic preparations].
AB - BACKGROUND: Modern guidelines of drug approval aim at interchangeability of drugs
containing the same active ingredients. Therapeutic equivalence of original and
generic drugs is assumed as soon as bioequivalence is documented. For this to be
accepted, first, pharmaceutical equivalence must prevail (the same amount of
active substances in the same dosage forms) and, second, differences in
bioavailabilities must not exceed certain limits. Drastic deviations from the
original--not infrequent in the past--have become rare under the new sets of
rules. CURRENT RELEVANCE: However, there is still room for sometimes stunning
discrepancies between approved drugs, since the current procedures--mainly for
economic reasons--do not cover some potentially relevant aspects: Usually,
studies are performed on young, healthy, mostly male volunteers; possible effects
of meals on bioavailability are not investigated and, after approval of a drug,
maintenance of attested quality--as with all manufacturers--is not monitored.
Moreover, the tolerated deviations from the bioavailability of the original drug
are quite large; with certain substances, a change from the generic drug with the
lowest bioavailability to that with the highest could mean transition from low
efficacy to a toxic dose level. Documented examples include carbamazepine,
phenytoin, levothyroxin, verapamil, and aspirin. CONCLUSIONS: In conclusion, even
today's sophisticated rules do not suffice to cover all eventualities. In
particular, drugs with a narrow therapeutic range require close scrutiny in
product selection. Pertinent are drug documentation as well as the distinguishing
features of the respective manufacturers, mainly scientific support and record of
product reliability. Besides the sometimes insufficient official documentation,
the internet has been gaining importance as a source of information.
PMID- 10668342
TI - [Possible genetic causes for late complications of diabetes mellitus].
AB - BACKGROUND: Hyperglycemia occurs in every patient with diabetes mellitus. It is
the most important factor in the development of diabetic complications. However,
the onset, intensity and the progression of complications show large
interindividual variations. Manifestation in families and the lack of
complications in some diabetics with poor metabolic control indicate a genetic
predisposition to develop diabetic complications like nephropathy, neuropathy and
angiopathy. NEPHROPATHY: Diabetic nephropathy occurs only in 25 to 40% of the
diabetic patients. Therefore a genetic risk factor for this complication is very
likely. Various variations in genes like ACE-gene and angiotensinogen-gene have
been described, which could be associated with the development of diabetic
nephropathy. NEUROPATHY: Peripheral diabetic neuropathy occurs in up to 66% of
all diabetics. Therefore and because of the possible pathological mechanisms
genetic risk factors like variations in the Na/K-ATPase-gene and in the aldose
reductase-gene are discussed. RETINOPATHY: An association between diabetic
retinopathy and polymorphisms in the ACE-gene and the aldose reductase-gene seems
very unlikely, because up to 75% of the diabetic patients suffer from retinopathy
after 15 years of diabetes. MACROANGIOPATHY: A large number of studies show an
association between diabetic macroangiopathy and genetic variations in the ACE
gene (I/D-variant) and the paraoxonase-gene (2 isoforms). CONCLUSION: Based on
the current evidence for associations of genetic markers with diabetic
complications, the generation of an individual risk profile based on genetic
markers seems to be possible. In addition to near euglycemia genetic markers
could direct therapeutic strategies and lead to new therapeutic approaches.
PMID- 10668343
TI - [Arthropathy in beta-thalassemia minor].
AB - CASE REPORT: A 25-year-old Turkish patient presented with a "swelling" of the
ankles which now persisted for 5 years. He had previously been diagnosed as
having HLA-B27 negative spondylarthropathy with peripheral joint involvement. The
symptoms failed to respond to different therapies. Serological markers and
radiological procedures revealed beta-thalassemia minor. DISCUSSION: Symptoms,
diagnostic procedures and differential diagnostic options are discussed.
PMID- 10668344
TI - [Ticlopidine-associated thrombotic thrombocytopenic purpura (Morbus
Moschcowitz)].
AB - ANAMNESIS AND CLINICAL FINDINGS: A 75-year-old woman with a history of recurrent
ischemic cerebral events was admitted with acute unspecific neurological symptoms
and fever. EXAMINATION: Intracerebral hemorrhage due to hypertension and
antithrombotic therapy with ticlopidine was ruled out with cranial computed
tomography. Laboratory findings on admission included thrombocytopenia (12/nl),
renal insufficiency (serum creatinine 1.6 mg/dl) and LDH elevation (1,218 U/l).
The hemoglobin on admission was normal. THERAPY AND CLINICAL COURSE: In the
presence of rapidly declining hemoglobin values and fragmentation of red cells
thrombotic-thrombocytopenic purpura (TTP) was diagnosed and the patient received
fresh frozen plasma. Shortly after the plasma infusion the patient's condition
deteriorated rapidly showing clinical signs of an allergic shock. In the sequel
of 24 to 48 hours the patient developed renal failure, severe anemia and the
thrombocyte count fell to 5/nl. The patient was mechanically ventilated during
the next 48 hours and needed intravenous catecholamines. Even after restoration
of spontaneous respiration and cessation of pharmacological sedation the patient
remained comatose. Cranial computed tomography on the fourth day after admission
showed multiple infarction syndrome. The patient died on the ninth day after
admission in status epilepticus which could not be stopped with pharmacological
means. CONCLUSIONS: The combination of neurological symptoms, thrombocytopenia,
fever, renal failure and hemolytic anemia in a patient taking ticlopidine points
to a diagnosis of TTP. The high mortality of TTP can probably only be reduced by
early plasmapheresis.
PMID- 10668345
TI - [TSH-secreting pituitary adenoma: 16 years follow-up].
PMID- 10668346
TI - [German recommendations for health care economic evaluation studies. Revised
version of the Hannover consensus. Hannover Consensus Group].
AB - Financial restrictions and stronger orientation towards outcomes increasingly
demand rational decisions to be made about the use of resources in the health
care system. Such decisions are the subject of medical, ethical and economic
considerations. Management of the health care system requires medical and
economic orientation both at the general level and with regard to the selection
of suitable forms of care in hospital and medical practices. In this context,
evaluative health economics can be a valuable decision-making aid. In order for
the results of health economic evaluation studies to be validly interpreted, a
minimum of standard methodology and sufficient transparency is required. To this
end, recommendations were developed. They are intended to convey standard
approaches, without unnecessarily constraining methodologic progress and
scientific freedom. Ongoing refinement of the guidelines and adaptation of the
current state of health economic research are desirable.
PMID- 10668347
TI - [Sense and nonsense of post-authorization surveillance].
PMID- 10668348
TI - The rank-order consistency of personality traits from childhood to old age: a
quantitative review of longitudinal studies.
AB - The present study used meta-analytic techniques to test whether trait consistency
maximizes and stabilizes at a specific period in the life course. From 152
longitudinal studies, 3,217 test-retest correlation coefficients were compiled.
Meta-analytic estimates of mean population test-retest correlation coefficients
showed that trait consistency increased from .31 in childhood to .54 during the
college years, to .64 at age 30, and then reached a plateau around .74 between
ages 50 and 70 when time interval was held constant at 6.7 years. Analysis of
moderators of consistency showed that the longitudinal time interval had a
negative relation to trait consistency and that temperament dimensions were less
consistent than adult personality traits.
PMID- 10668349
TI - Factors influencing racial comparisons of self-esteem: a quantitative review.
AB - Research on racial comparisons of self-esteem was examined. Early research in
this area, exemplified by the doll studies of racial preference, was viewed as
demonstrating that Blacks have less self-regard than Whites. However, a meta
analytic synthesis of 261 comparisons, based largely on self-esteem scales and
involving more than half a million respondents, revealed higher scores for Black
than for White children, adolescents, and young adults. This analysis further
revealed that the direction and magnitude of racial differences are influenced by
such demographic characteristics as participant age and socioeconomic status, as
well as by characteristics of the measuring instruments. Many findings--for
example, that the self-esteem advantage for Black respondents increases with age
and is related to the sex composition of the sample--underscore the need for long
term longitudinal studies of self-esteem development in male and female members
of both racial groups.
PMID- 10668350
TI - Evolution and proximate expression of human paternal investment.
AB - In more than 95% of mammalian species, males provide little direct investment in
the well-being of their offspring. Humans are one notable exception to this
pattern and, to date, the factors that contributed to the evolution and the
proximate expression of human paternal care are unexplained (T. H. Clutton-Brock,
1989). The nature, extent, and influence of human paternal investment on the
physical and social well-being of children are reviewed in light of the social
and ecological factors that are associated with paternal investment in other
species. On the basis of this review, discussion of the evolution and proximate
expression of human paternal investment is provided.
PMID- 10668351
TI - Nonshared environment: a theoretical, methodological, and quantitative review.
AB - When genetic similarity is controlled, siblings often appear no more alike than
individuals selected at random from the population. Since R. Plomin and D.
Daniels' seminal 1987 review, it has become widely accepted that the source of
this dissimilarity is a variance component called nonshared environment. The
authors review the conceptual foundations of nonshared environment, with emphasis
on distinctions between components of environmental variance and causal
properties of environmental events and between the effective and objective
aspects of the environment. A statistical model of shared and nonshared
environmental variables is developed. A quantitative review shows that measured
nonshared environmental variables do not account for a substantial portion of the
nonshared variability posited by biometric studies of behavior. Other
explanations of the preponderance of nonshared environmental variability are
suggested.
PMID- 10668352
TI - Intuition: a social cognitive neuroscience approach.
AB - This review proposes that implicit learning processes are the cognitive substrate
of social intuition. This hypothesis is supported by (a) the conceptual
correspondence between implicit learning and social intuition (nonverbal
communication) and (b) a review of relevant neuropsychological (Huntington's and
Parkinson's disease), neuroimaging, neurophysiological, and neuroanatomical data.
It is concluded that the caudate and putamen, in the basal ganglia, are central
components of both intuition and implicit learning, supporting the proposed
relationship. Parallel, but distinct, processes of judgment and action are
demonstrated at each of the social, cognitive, and neural levels of analysis.
Additionally, explicit attempts to learn a sequence can interfere with implicit
learning. The possible relevance of the computations of the basal ganglia to
emotional appraisal, automatic evaluation, script processing, and decision making
are discussed.
PMID- 10668353
TI - Eyeblink classical conditioning: hippocampal formation is for neutral stimulus
associations as cerebellum is for association-response.
AB - Extensive evidence has been amassed that the cerebellum, hippocampus, and
associated circuitry are activated during classical conditioning of the
nictitating membrane/eyeblink response. In this article, the authors argue that
the cerebellum is essential to all eyeblink classical conditioning paradigms. In
addition, the septohippocampal system plays a critical role when the classical
conditioning paradigm requires the formation of associations in addition to the
simple association between the conditioned and unconditioned stimuli. When only a
simple conditioned stimulus--unconditioned stimulus association is needed, the
septohippocampal system has a more limited, modulatory role. The neutral stimulus
association versus simple association-response distinction is one of the ways in
which declarative or relational memory can be separated from nondeclarative or
nonrelational memory in classical conditioning paradigms.
PMID- 10668354
TI - Rhythm and pitch in music cognition.
AB - Rhythm and pitch are the 2 primary dimensions of music. They are interesting
psychologically because simple, well-defined units combine to form highly complex
and varied patterns. This article brings together the major developments in
research on how these dimensions are perceived and remembered, beginning with
psychophysical results on time and pitch perception. Progressively larger units
are considered, moving from basic psychological categories of temporal and
frequency ratios, to pulse and scale, to metrical and tonal hierarchies, to the
formation of musical rhythms and melodies, and finally to the cognitive
representation of large-scale musical form. Interactions between the dimensions
are considered, and major theoretical proposals are described. The article
identifies various links between musical structure and perceptual and cognitive
processes, suggesting psychological influences on how sounds are patterned in
music.
PMID- 10668355
TI - [The test for the evaluation speech perception and production].
AB - The aim of this paper is to present a Test to evaluate the speech perception and
production in french profoundly hearing impaired children fitted with cochlear
implant or traditional hearing aids. This test materials have been developed for
children from 2 to 10 years old. This test fall into two basic categories known
as speech perception and speech production. The assessment of the perceptual
abilities through the use of the TEPPP is achieved across the hierarchy of
perception which spans: detection, discrimination, identification, comprehension.
The assessment of the speech production makes it possible to observe the speech
production changes across three levels: phonetical, linguistical,
intelligibility. The TEPPP, Test of Speech Perception and Production evaluation,
enable us to observe if children, who receive a cochlear implant or a
conventional hearing aids, obtain some degree of benefit in both speech
perception and speech production.
PMID- 10668356
TI - [The dynamics of the spoken language and parental guidance].
AB - The aim of parental guidance of deaf children is to allow the parents to
understand and adapt to the unusual language development of their child. The
authors propose a system of explanation of the control of language which will
lead to the development of confidence, relaxation and spontaneity--the three
determining factors--as well as to enlightenment; it will act as a point of
reference during their introduction to the physiology of language, and as a
guideline for the attitude of rehabilitation which needs to be adopted.
PMID- 10668357
TI - [Value of the relative phonetogram (RP) for the evaluation of organic
dysphonias].
AB - The phonetogram in a recognized element of voice evaluation, but its relation to
perceptual voice quality is unclarified. The phonetograms area is easy to measure
since the existence of efficient computer software. So information about
frequency and intensity range can be united in one single parameter. The
individual phonetogram area in relation to a gender- and training-specific normal
value constitutes the "relative phonetogram (RP)". A prospective evaluation of
the relative phonetogram was performed by means of a statistical analysis of its
correlation to perceptual voice assessment (grade/rough/breathy) and to maximal
phonation time. The acoustic parameters jitter, shimmer, SNR were examined in the
same way, to allow for comparison of the RP's importance with the importance of
common "objective" features in the identical group of patients. 114 patients with
two subsets are included: 61 patients after partial laryngectomy (laser or
conventional surgery), 53 patients with different glottic pathologies. The
perceptive evaluation was done by a trained jury of an ENT-specialist and a
speech therapist. The phonetogram and the maximal phonation time were measured by
a trained medical student with regard of the examination references publicated by
the Union of European Phoniatrics. The computer software for area measurement was
MSImageProPlus, the one for sound analysis was Dr. Speech (Tiger Electronics).
Statistical program: SPSS 8.0. RESULTS: The comparison between the two subsets of
patients shows lower RPs for partial laryngectomy than for other patients in all
degrees of hoarseness. In both subsets there is a correlation between RP and
hoarseness values: the average values of RP differ significantly in dependence of
grande. This is even more marked for the patients after laryngeal surgery.
Furthermore high RPs are only present in patients with (relatively) high maximal
phonation time, and mean RP correlates with maximal phonation time. A correlation
between the parameters of sound analysis and the score of "grade" exists, but is
not as marked as for the RP. CONCLUSION: The significance of the RP's mean value
for subsets of 15-20 patients has been demonstrated. It is justified to interpret
a certain variance of this parameter as difference in the degree of hoarseness.
In this context, the importance of the mean RP is higher than the importance of
jitter, shimmer, SNR (when measured with the above mentioned computer program,
which allows no evaluation of parameter combinations). Therefore this parameter
could be interesting for comparison of dysphonic patients, for instance after
glottic cancer treatment.
PMID- 10668358
TI - A study of vibrato: assessment by panel of judges compared to spectral voice
analysis.
AB - Experts in voice singing and voice training were asked to judge the vibrato of 30
singers (4 samples per singer: a sung [a] held without vibrato; a sung a[ held
with vibrato; a self-selected passage and an imposed passage. In the first part,
they ticked the type of oscillations (vibrato, straight tone, tremolo,
quivering...). In the second part, they appraised various criteria. Intra-judge
and inter-judge consistencies were determined. The subjective parameters were
thereafter correlated with the measurements of six parameters of the MDVP
(MultiDimentional Voice Program). The measurements were carried out on each task.
Intra-judge consistency was good for only one judge (67-87% consistency). Since
judge 2 and 3 were hardly reproducible (45-73%; 28-57%) measurement of the inter
judge consistency was pointless. The results of judge 1 were correlated with the
Fundamental Tremor Frequency Index, the jitter and the shimmer.
PMID- 10668359
TI - The ultra-low resistance Groningen voice prosthesis: aerodynamic properties.
AB - Post-laryngectomy voice rehabilitation using the low resistance (LR) Groningen
voice prosthesis has over the past years provided good voice and speech results.
The valve part of the prosthesis is largely responsible for the airflow
resistance of the prosthesis. This study was performed to evaluate if by
modifying the valve part of the LR Groningen prosthesis a lower airflow
resistance in vitro could be achieved. Several prototypes with modified valves
were tested. Based on the aerodynamic measurements the prosthesis with a single
slit of 200 degrees in the 'hat' of the esophageal flange was selected for
further evaluation and named the ultra-low resistance (ULR) Groningen voice
prosthesis. Aerodynamic measurements were performed and showed the airflow
resistance of the ULR Groningen voice prosthesis to be significantly lower than
the resistance of the LR Groningen and the Provox voice prostheses.
PMID- 10668360
TI - [Acoustic comparison of esophageal versus tracheoesophageal speech].
AB - The authors present results of an acoustic criterions analysis made next to 57
subjects, who had undergone total laryngectomy or total pharyngolaryngectomy,
between 6 months and 3 years before. The study allows to assess, next to 29
tracheoesophageal voices and 30 oesophageal voices, the fundamental frequency,
the vocal extensive, the maximum phonation time, and the study of pauses (number
and time) in a reference sentence. The acoustic advantages of phonatory prothesis
are confirmed, but the oesophageal voice knowledge must not be forgotten.
PMID- 10668361
TI - [Long-term results of swallowing after horizontal sub-glottic laryngectomy].
AB - This is a retrospective study of 80 patients who have had a horizontal subglottic
laryngectomy. The functional results were assessed by means of clinical findings
at follow-up and a questionnaire. The mean time to decannulation was 32 days, and
to removal of the nasogastric tube 25 days. 45% of patients had no fistula. Of
the remaining 55%, there was a false passage for fluids in 90%. These fistulae
remained patent for an average of 12 weeks. At one year and beyond, 40% of
patients were on a normal diet, 33% were on ground food, 10% on a soft paste
diet, 6% on a semi-liquid diet, and 10% were fed by tube. The factors militating
towards poor function are age above 65 years, and previous radiotherapy.
PMID- 10668362
TI - Studies on swallowing in patients operated by subtotal laryngectomy.
AB - A series of 39 patients with problems of deglutition after total laryngectomy was
studied by X-ray screening and manometry. The importance of the retropulsive
movement of the tongue on the quality of deglutition has been demonstrated, as
has the function of the superior oesophageal constrictor, the effect of a reduced
relaxation time, and of the force of suction in reducing its quality.
PMID- 10668363
TI - [Anatomy and anatomopathology of benign vocal cord lesions].
AB - After 30 years of experience comprising more than 3000 suspension laryngoscopies,
we are putting forward a classification of the main benign lesions of the vocal
cords. Among the acquired group, we make a distinction between those caused by
vocal overuse and abuse and those with a cause within the vocal cord. Congenital
lesions are certainly more common than is usually thought. The hypothesis of a
congenital origin would certainly justify a larger prospective study.
PMID- 10668364
TI - Flexible sigmoidoscopy revisited.
PMID- 10668365
TI - Breaking the PPM contract. How to regain independence when PPM ownership no
longer works.
PMID- 10668366
TI - Unwinding the physician's employment: choosing a practice structure.
PMID- 10668367
TI - Medical mistakes: decreasing the "oops" factor.
PMID- 10668368
TI - Postoperative care--inattentive approach.
PMID- 10668369
TI - Managed care preauthorization practices: implications for the emergency
department.
PMID- 10668370
TI - The hepatitis C epidemic in the hemophilia community.
PMID- 10668371
TI - A patient with an acute viral syndrome.
PMID- 10668372
TI - [Information for handling].
PMID- 10668373
TI - [Xenotransplantation].
PMID- 10668374
TI - [Vitamin A as an antidote against skin cancer?].
PMID- 10668375
TI - [Intracranial arachnoidal cysts--localization, gender and sidedness].
AB - The aim of the present study was to investigate whether data on location and
distribution of intracranial cysts in a large patient population may explain why
and how such cysts are formed. We investigated 123 patients with 129 intracranial
cysts, consecutively admitted to the Department of Neurosurgery in Bergen 1988
97. Data were analyzed with regard to intracranial location and gender
distribution. Cysts were much more commonly located in the temporal fossae than
one would expect if the distribution were random; 68.1% of patients had temporal
cysts. We suggest a theory that may explain how mal-development of the
leptomeninges may contribute to the formation of cysts, and why such cysts are
more common in the temporal fossae. Temporal cysts were significantly more
frequent in males than in females (3.9:1), while cysts of other locations did not
show preponderance for a specific gender. New in this study is the interesting
connection between gender distribution and sidedness: the significant
predominance of left-sided temporal cysts was found only in males. In patients
with a unilateral temporal cyst, the left/right ratio was 2.0:1 (males 44 left
and 20 right, females eight left and six right). We discuss whether the
preponderance of left-sided temporal cysts in males can be explained by a gender
specific developmental failure, as previously suggested for dyslexia.
PMID- 10668376
TI - [Intracranial arachnoidal cysts--some neuropsychological experiences].
AB - Arachnoid cysts may cause neurological symptoms. The aim of this study was to
investigate whether they also affect cognition. 31 patients (26 males and five
females) underwent decompressive surgery for a symptomatic cyst in the left
temporal fossa, with craniotomy and fenestration or with a cystosubdural shunt.
The patients were tested for asymmetries in verbal perception and verbal memory
before and after surgery, using dichotic listening techniques with different
auditory stimuli presented simultaneously to the two ears. In the preoperative
perception (dichotic listening-DL) test, the patients failed to show the normal
advantage for auditory input to the right ear. After decompression, their DL
performance normalised, as they now had a right ear advantage. In the
preoperative dichotic memory test, the patients differed significantly from a
normal reference group in two respects: they remembered fewer words, and they
exhibited a clear left ear advantage, in contrast to the normal right ear
advantage seen in the reference group. Postoperatively, overall memory
performance was enhanced, and the preoperative superiority of the left ear had
changed to a normal right ear advantage. The results indicate that arachnoid
cysts in the left temporal fossa impair cognition, that neuropsychological tests
are required to disclose such impairments, and that decompressive surgery
improves cognition.
PMID- 10668377
TI - [Transrectal specimens in recurrent rectal cancer].
AB - The majority of rectal cancer recurrences develop within the pelvis but outside
the bowel. In clinical practice these tumours have been palpable in the pelvis
for some time before a positive mucosal biopsy is obtained at the time when the
cancer penetrates the mucosa of the neorectum or vagina. We present our
experience with transrectal digitally guided fine needle aspiration cytology
(FNAC) taken through intact mucosa or from intraluminal tumours. The sensitivity
of the cytology was 0.88 versus 0.68 of the fine needle core biopsy (FNCB)
specimens (p < 0.005); no false positive cancer diagnoses were reported. The
simple and cost-effective digitally guided transrectal biopsy procedure may be
adequate for an early morphological diagnosis, avoiding the more expensive CT or
ultrasonically guided biopsies. It is safe and easy to take the biopsies and the
complication rate is low. Surgical treatment for locally recurrent rectal cancer
is justified. In combination with radiation therapy, it offers pain relief and
improved quality of life. Survival is prolonged and cure can be achieved in up to
one third of patients.
PMID- 10668378
TI - [Hospital admissions due to obstructive lung diseases and pneumonia in two
hospital districts].
AB - Admission rates for specific diseases in a defined district can be used as a
coarse estimate of the need for health services. Such registration has not
previously been conducted in the hospital districts of Bergen and Haugesund. We
recorded all patients 16 years and older admitted to three hospitals for
obstructive lung disease or pneumonia in the two hospital districts of Bergen and
Haugesund in April to June 1997. A total of 438 patients were included in both
districts, 246 with obstructive lung disease and 192 with pneumonia. The
admission rate for obstructive lung disease was 359 per 100,000 inhabitants per
year, for pneumonia 280 per 100,000 inhabitants per year. Median age was between
71 and 75 years for men and women for both diseases. 13% of patients with
obstructive lung disease were readmitted to the hospital within 30 days.
Obstructive lung disease and pneumonia are common causes of hospital admission,
especially among older persons. The admission rates for both diseases combined
were 639 per 100,000 adults per year in the hospital districts of Bergen and
Haugesund.
PMID- 10668379
TI - [Amputation or reconstruction of a circulatory compromised severely injured
extremity?].
AB - 18 patients treated with primary or secondary amputations after severe lower limb
open fractures were studied. All limbs had clinical signs of a compromised
circulation at the primary evaluation. The various injuries are described and
discussed with respect to the general guidelines for primary amputation. The
Mangled Extremity Severity Score (MESS) and Nerve, Ischemia, Soft tissues,
Skeletal, Shock, Age (NISSSA) scores were calculated. In view of the described
injuries, primary amputation was indicated in ten patients according to the
general recommendations, 11 patients according to NISSSA and 15 patients
according to MESS. Delayed amputation leads t a significantly (p = 0.005) higher
number of operative procedures than early amputation (9.2 vs. 2.9 treatments).
The decision of whether to amputate or not should be based on sound clinical
judgement, but injury scores such as MESS and NISSSA may be helpful.
PMID- 10668380
TI - [Catheter-directed thrombolytic therapy--a current alternative to proximal deep
venous thrombosis].
AB - Deep venous thrombosis extending into the iliac veins is associated with
significant acute and late morbidity despite adequate conventional treatment with
heparin and oral anticoagulants. The purpose of this paper is to focus on a
multidisciplinary, aggressive approach with catheter-directed thrombolysis, in
which a catheter with many side-holes is placed within the thrombus and
thrombolytics infused. The aim is to eliminate the thrombus, to provide
unobstructed venous drainage from the affected limb, and to prevent recurrent
thrombosis. Total recanalisation of the iliofemoral segment was achieved in three
of four treated patients, while partial lysis was obtained in one patient with
symptoms for four weeks. Two weeks after discharge, two patients had no symptoms,
while two had a moderate leg oedema. All of the three women used oral
contraceptives at the time of thrombus formation; two had hereditary
thrombophilia. Most probably, successful catheter-directed thrombolysis will
reduce the incidence of post-thrombotic syndrome, but there are no long-term
follow-up studies after such treatment.
PMID- 10668381
TI - [Life-saving hemicraniectomy in acute massive brain infarction].
AB - Acute occlusion of the middle cerebral artery is an important cause of ischemic
stroke. The resulting brain infarction is often very large, leading to massive
brain oedema and intracranial hypertension. Despite intensive medical treatment,
the mortality rate due to herniation and cerebral circulatory arrest remains very
high. A Norwegian left-handed male, 28 years of age, developed signs of impending
herniation following an acute right-side middle cerebral artery occlusion. When
admitted to neurosurgical care 54 hours after the stroke, he was soporous, had a
left-side hemiparalysis, conjugated deviation of the gaze and a mydriatic pupil
on the right side. The intracranial pressure level was between 30 and 40 mm Hg.
Following a right-side hemicraniectomy, the intracranial pressure fell to levels
around 20 mm Hg. The bone flap was replaced four months later. One year after the
stroke, the patient is fully independent of others, despite a left-side
hemianopia and hemiparesis. Hemicraniectomy may be indicated in selected patients
with impending herniation due to brain infarction. Intracranial pressure
recordings are useful as an adjunct in the management of these patients. Our
report seems to be the first account of decompressive hemicraniectomy performed
in Norway for acute massive brain infarction.
PMID- 10668382
TI - [Massive pulmonary embolism--echocardiographic diagnosis and thrombolytic
therapy].
AB - Thrombolysis is widely accepted as the treatment of choice for acute massive life
threatening pulmonary embolism. Several trials have shown that thrombolytic
treatment has reduced morbidity and mortality in this condition, compared to
heparin therapy. Rapid diagnosis and treatment start is mandatory for improving
the prognosis. Clinical presentation, ECG, arterial blood gas analysis and D
dimer are non-specific tests. Additional tests like ventilation/perfusion lung
scan, spiral-computed tomography or pulmonary angiography are needed. In an
emergency situation a non-invasive and bedside technique is preferred, and
several studies have demonstrated the accuracy of echocardiography in pulmonary
embolism. Acute right ventricular overload is indicated by different
echocardiographic findings. Three cases with the echocardiographic method as the
initial technique for the diagnosis of massive pulmonary embolism are described
as well as the treatment consequence and practical administration of
thrombolysis. Our patients had presenting features suggestive of massive
pulmonary embolism, a clinical situation where an echocardiographic evaluation is
appropriate. All presented with typical echocardiographic features. Thrombolytic
treatment was initiated immediately after echocardiographic diagnosis. Different
thrombolytic regimens were used. Echocardiography may be used as the initial
imaging technique for the diagnosis of massive pulmonary embolism. The advantages
are obvious, and thrombolytic treatment can be initiated without delay.
PMID- 10668383
TI - [Decompression craniectomy--life-saving treatment in acute cerebral infarction].
AB - Massive cerebral infarction is often accompanied by early death secondary to
transtentorial herniation. Decompressive hemicraniectomy has been suggested as a
lifesaving procedure. We report the case of a 61 year old man who had an acute
infarction in the distribution area of the right middle cerebral artery.
Initially, he was awake and suffered from total left-sided hemiparalysis. Over
the next two days, his level of consciousness deteriorated to a Glasgow Coma
Scale score of 5. Intracranial pressure (ICP) monitoring was then established.
Three days later, the ICP increased from 20 to 40 mm Hg. We performed a right
sided decompressive hemicraniectomy, and the ICP was normalized immediately. Ten
months after surgery the patient was at home and functioning with minimal
assistance. He had moderate paresis of the left leg and was able to walk, but his
left arm was paralytic. The presented case confirms that decompressive
hemicraniectomy may prevent death and allow survival without severe disability in
patients with massive cerebral infarction.
PMID- 10668384
TI - [An elderly woman with constipation problems].
PMID- 10668385
TI - [Corneal transplantation].
AB - The first successful corneal transplantation was done in 1906, when the corneas
of a recently deceased boy were transferred to a man blinded by an alkali burn.
Since then, improved equipment, microsurgical technique and better methods for
treating postoperative complications have greatly improved the prognosis of
corneal grafting. Immunological reactions are less frequently seen after
keratoplasty than after other types of transplantation, and the graft is also
directly accessible for immunosuppressive treatment. Penetrating keratoplasty
accounts for more than 95% of all corneal transplantations in Norway, the other
procedures being lamellar grafting and epikeratophakia. While keratitis and
macula corneae previously were the main indications for keratoplasty, keratoconus
is at present the most frequent indication. The prognosis is poorer in eyes with
extensive vascularization, lacking sensibility, insufficient tear secretion and
marked symblepharon. Due to shortage of suitable donor tissue, the waiting lists
for this type of ocular surgery are increasing.
PMID- 10668386
TI - [Transplantation from animal to man].
AB - Because of a severe shortage of donor organs, organ transplantation therapy can
only be offered to a fraction of all patients needing it. This has sparked an
increasing interest in xenotransplantation. Transgenic pigs could potentially
provide tissue and organs to thousands of patients on waiting lists world-wide.
Xenografts may be used as bridges or as permanent alternatives to organ
allotransplants. Clinical trials of transplantation of pig cells and tissues to
treat diabetes and neurodegenerative disorders are in progress. The most striking
immunologic obstacle to xenotransplantation of solid organs, that of hyperacute
rejection, is close to being overcome. Next steps in research are to refine
immunosuppression, improve our knowledge of physiology and to allow for small and
strictly regulated clinical studies. However, the risk for the recipients from
infectious agents, particularly retroviruses, and potential dissemination of
these in the human population cannot be ignored and must be thoroughly
investigated. Ethical, safety, and monitoring guidelines are needed to control
the development of xenotransplantation.
PMID- 10668387
TI - [Treatment of diabetes mellitus with transplantation of immunoprotected
pancreatic islet tissue].
AB - Research in islet transplantation in the treatment of diabetes mellitus is making
rapid progress. Vascularized pancreas allotransplantation is now an accepted
treatment, but with major limitations. The shortage of human islets for
allotransplantation requires new sources of insulin-producing tissue.
Xenotransplantation is one such approach, though the procedure is limited by
immunological rejection of the graft. Immunoisolation of insulin-producing graft
in alginate capsules protects the transplant from immunological damage. The
alginate capsule consists of a semipermeable membrane, which act as an
immunological barrier between the graft and the host. In addition to exclude
immunocells and humoral mediators of rejection, the membrane must be permeable to
nutrients and toxic end products from the cell metabolism, and permit free
diffusion of glucose and insulin. We may hope that this immunoisolating technique
will establish prolonged survival of allo- or xenografted tissue without
immunosuppressive treatment.
PMID- 10668388
TI - [Abortion--family planning and a human right].
PMID- 10668389
TI - [Improved routines in connection with thrombolytic therapy in myocardial
infarction].
PMID- 10668390
TI - [Clinical significance of antibodies against red blood cells].
PMID- 10668391
TI - [Ethical problems at the end of life].
PMID- 10668392
TI - [Family practice--professional content].
PMID- 10668393
TI - Protein folding and deficiencies caused by dominant-negative mutants of hormones.
AB - Protein folding and transport in the secretory pathway of cells is a controlled
process, facilitated by chaperones. Proteins that do not fold well elicit several
different programmed responses from the cells. A comparison of mutants of growth
hormone that result in growth hormone deficiency suggests that cells do not
respond in the same way to all growth hormone mutants that cannot fold, because
some mutants are dominant and some are recessive. Causes for autosomal dominant
hormone deficiencies include accumulation of toxic or dysfunctional forms,
competition for chaperones important for folding or transport, induction of
protein degradation in the endoplasmic reticulum, or long-term responses of the
cells to synthesis of proteins that do not fold that decrease hormone synthesis
or cell viability.
PMID- 10668394
TI - Structural aspects of the G-protein receptor, rhodopsin.
PMID- 10668395
TI - Molecular modeling of mammalian cytochromes P450: application to study enzyme
function.
AB - Cytochromes P450 are important heme-containing enzymes that catalyze the
oxidation of a vast array of endogenous and exogenous compounds, including drugs
and carcinogens. One of the more successful approaches to study P450 function
involves molecular modeling. Because none of the mammalian P450s have been
crystallized, a number of homology models have been constructed based on the
structures of known bacterial P450s. Molecular models, generated using molecular
replacement or distance geometry methods, can be used to dock substrates and/or
inhibitors in the active site to explain various aspects of enzyme function. The
majority of modeling research has dealt with enzyme-substrate interactions in the
active site. The analysis of these interactions has helped us to better
understand the mechanism of P450 catalysis and provided the structural basis for
the regio- and stereospecificity of substrate oxidation as well as susceptibility
to inhibition or inactivation. The models have been utilized to identify and/or
confirm key residues and to rationally interpret experimental data. The
alteration in activity in a mutant P450 can be related to changes in enzyme
substrate/inhibitor interactions, such as the removal or appearance of van der
Waals overlaps or changes in compound mobility. Homology models can also help to
analyze P450-redox partner interactions and identify critical determinants of
protein stability. We can expect further development of molecular modeling
methods and their increasing contribution into research on P450 function as an
integral part of a combined theoretical-experimental approach.
PMID- 10668396
TI - Prostaglandin D synthase: structure and function.
AB - Prostaglandin (PG) D synthase catalyzes the isomerization of PGH2, a common
precursor of various prostanoids, to produce PGD2 in the presence of sulfhydryl
compounds. PGD2 induces sleep, regulates nociception, inhibits platelet
aggregation, acts as an allergic mediator, and is further converted to 9 alpha,
11 beta-PGF2 or the J series of prostanoids, such as PGJ2, delta 12-PGJ2, and 15
deoxy-delta 12,14-PGJ2. We have purified two distinct types of PGD synthase; one
is the lipocalin-type enzyme and the other is the hematopoietic enzyme. We
isolated the cDNA and the gene for each enzyme and determined the tissue
distribution profile and the cellular localization in several animal species.
Lipocalin-type PGD synthase is localized in the central nervous system and male
genital organs of various mammals and the human heart and is secreted into
cerebrospinal fluid, seminal plasma, and plasma, respectively. The human enzyme
was identified as beta-trace, which is a major protein in human cerebrospinal
fluid. This enzyme is considered to be a dual-function protein; it acts as a PGD2
producing enzyme and also as a lipophilic ligand-binding protein, because the
enzyme binds retinoids, thyroids, and bile pigments, with high affinities.
Hematopoietic PGD synthase is widely distributed in the peripheral tissues and
localized in the antigen-presenting cells, mast cells, and megakaryocytes. The
hematopoietic enzyme is the first recognized vertebrate homolog of the sigma
class of glutathione S-transferase. X-ray crystallographic analyses and
generation of gene-knockout and transgenic mice for each enzyme have been
performed.
PMID- 10668397
TI - Steroid dehydrogenase structures, mechanism of action, and disease.
AB - Steroid dehydrogenase enzymes influence mammalian reproduction, hypertension,
neoplasia, and digestion. The three-dimensional structures of steroid
dehydrogenase enzymes reveal the position of the catalytic triad, a possible
mechanism of keto-hydroxyl interconversion, a molecular mechanism of inhibition,
and the basis for selectivity. Glycyrrhizic acid, the active ingredient in
licorice, and its metabolite carbenoxolone are potent inhibitors of human 11 beta
hydroxysteroid dehydrogenase and bacterial 3 alpha, 20 beta-hydroxysteroid
dehydrogenase (3 alpha, 20 beta-HSD). The three-dimensional structure of the 3
alpha, 20 beta-HSD carbenoxolone complex unequivocally verifies the postulated
active site of the enzyme, shows that inhibition is a result of direct
competition with the substrate for binding, and provides a plausible model for
the mechanism of inhibition of 11 beta-hydroxysteroid dehydrogenase by
carbenoxolone. The structure of the ternary complex of human 17 beta
hydroxysteroid dehydrogenase type 1 (17 beta-HSD) with the cofactor NADP+ and the
antiestrogen equilin reveals the details of binding of an inhibitor in the active
site of the enzyme and the possible roles of various amino acids in the catalytic
cleft. The short-chain dehydrogenase reductase (SDR) family includes these
steroid dehydrogenase enzymes and more than 60 other proteins from human,
mammalian, insect, and bacterial sources. Most members of the family contain the
tyrosine and lysine of the catalytic triad in a YxxxK sequence. X-ray crystal
structures of 13 members of the family have been completed. When the alpha-carbon
backbone of the cofactor binding domains of the structures are superimposed, the
conserved residues are at the core of the structure and in the cofactor binding
domain, but not in the substrate binding pocket.
PMID- 10668398
TI - Structure-based inhibitor design.
AB - Time and costs associated with the discovery of new drugs have been significantly
reduced by enzyme structure-based approaches to the discovery of new
chemotherapeutic agents. However, fundamental components of the overall approach
continue to rely on technologies which, by their nature, involve relatively
random processes (i.e., combinatorial chemistry and high-throughput screening).
Thus, the efficiency of the drug discovery process potentially could be further
improved through better use of structural information. In this regard, three
dimensional structures of enzymes are now being solved at high resolution and/or
in conformations that provide data that should be more useful for inhibitor
design or discovery. Scientists are beginning to appreciate the importance of
water as a possible competitor of inhibitors for binding to target enzymes. New
computational algorithms are improving the efficiency of identifying flexible
inhibitors from among the large numbers of compounds in chemical databases. Also,
tools of molecular genetics together with structures of target enzymes are likely
to be used more frequently in dealing with the development of resistance to novel
chemotherapeutic agents. Instead of detailing success stories in structure-based
drug discovery, the following article considers how future efforts to discover or
design new drugs may increasingly rely on information about molecular targets and
less on data acquired via approaches involving random methodologies.
PMID- 10668399
TI - Protein folding using contact maps.
AB - We discuss the problem of representations of protein structure and give the
definition of contact maps. We present a method to obtain a three-dimensional
polypeptide conformation from a contact map. We also explain how to deal with the
case of nonphysical contact maps. We describe a stochastic method to perform
dynamics in contact map space. We explain how the motion is restricted to
physical regions of the space. First, we introduce the exact free energy of a
contact map and discuss two simple approximations to it. Second, we present a
method to derive energy parameters based on perception learning. We prove in an
extensive number of situations that the pairwise contact approximation both when
alone and when supplemented with a hydrophobic term is unsuitable for stabilizing
proteins' native states.
PMID- 10668400
TI - HIV protease: enzyme function and drug resistance.
AB - HIV protease is responsible for processing of the gag and gag-pol polyproteins
during virion maturation. The activity of this enzyme is essential for virus
infectivity, rendering the protein a major therapeutic target for AIDS treatment.
This articles reviews the biochemical and biophysical properties of the enzyme.
The clinical and in vitro observations of resistance to protease inhibitors are
discussed from the perspective of drug resistance mechanisms of HIV protease
mutants.
PMID- 10668401
TI - Ultrastructure of cells undergoing apoptosis.
PMID- 10668402
TI - Role of cytoskeleton in apoptosis.
AB - Apoptosis is a form of cell death that takes place under physiologic conditions,
and plays a key role in the control of biological processes such as embryonic
development, tissue remodelation and renewal, or regulation of cell populations.
Since its discovery in the early 1970s, there have been many relevant advances in
the knowledge of the biochemical and molecular events involved in apoptosis.
However, although the apoptotic process was defined on the basis of morphologic
observations, only recently have we started to elucidate the molecular mechanisms
that drive the structural changes observed in cells undergoing apoptosis. The
article reviews current knowledge about the implications of cytoskeleton
components (microfilaments, intermediate filaments, microtubules, and other
cytoskeleton-related proteins) in the dynamics of apoptosis.
PMID- 10668403
TI - Dietary antioxidants and cardiovascular disease.
PMID- 10668404
TI - Melatonin receptors and ligands.
AB - The goal of the article is to provide a clearer understanding of how melatonin
and its related analogs interact with melatonin receptors with the hope of
developing important tools and agents of significant clinical and scientific
importance. The review provides a compilation of the currently published
melatonergic ligands and their relative affinities for melatonin receptors and
discusses the importance of developing reversible, high-affinity, and subtype
selective melatonin receptor antagonists. In addition, the review discusses the
utility of developing high-affinity charged melatonergic ligands and irreversible
ligands. Finally, the review discusses some of the problems associated with the
current models used to study receptor pharmacology and function. As the
availability of tools increases in the melatonin receptor field, a great body of
knowledge is also gained about the structure of the melatonin receptor and the
role that specific melatonin receptor subtypes have in physiologic processes.
Further design, synthesis, and application of melatonergic ligands will lead us
to a clearer understanding of the role that melatonin and its receptors play in
humans.
PMID- 10668405
TI - Vitamin K-dependent proteins.
AB - Vitamin K is required for the synthesis of gamma-carboxyglutamate (Gla) during
postribosomal protein modification. Substrates include blood clotting proteins,
bone proteins, cell signaling, and receptor proteins. In addition, Gla is a
component of short toxin peptides from the marine snail Conus. Studies of
structure-function relationships are the most advanced for the blood coagulation
proteins. Reviews of vitamin K action and blood coagulation are presented.
Special focus is on the structure-function role of Gla in blood coagulation and
the impact of this amino acid on enzyme reaction kinetics. This amino acid forms
calcium and membrane binding sites for these proteins. Two proposed mechanisms of
protein-membrane attachment are reviewed. One involves membrane attachment by
protein insertion into the hydrocarbon region of the membrane, while another
considers attachment by specific interactions with phospholipid head groups.
Membrane attachment generates the potential for several forms of nonclassical
enzyme kinetic behaviors, all of which have been observed in vitro. For example,
the reaction may be limited by properties of the enzyme active site, a condition
that allows use of classic steady-state enzyme kinetic parameters. However, the
reaction may be limited by substrate binding to the membrane, by substrate flux
through solution, and/or by solvent flow rates across the membrane surface. These
states provide special mechanisms that are not anticipated by classical steady
state kinetic derivations. They may be used to regulate coagulation in vivo.
Overall, vitamin K research spans the spectrum of biological research and
experience. Exciting new ideas and findings continue to emanate from vitamin K
related research.
PMID- 10668406
TI - Steroid/nuclear receptor coactivators.
AB - In higher eukaryotes, steroids/thyroid hormones and many lipophilic compounds
regulate cellular physiology through binding to the steroid/nuclear receptor
proteins. Steroid/nuclear receptors are ligand-dependent transcriptional
activators that can stimulate gene expression. This transcriptional activation
plays a pivotal role in hormone-regulated physiological and pharmacological
responses. In recent years, several steroid/nuclear receptor cofactors have been
identified and found to interact with the receptor and modulate its
transcriptional activity. Among these cofactors, a family of three co-activators
has been the focus of intense studies. Although gaps remain, progress has been
made in understanding how a given co-activator interacts with the receptor and
promotes transcriptional activation. We are beginning to understand co-activator
action; for instance, several studies have established the molecular basis of
antagonism by anti-hormones and the connection of co-activators with human
cancers.
PMID- 10668407
TI - Thyroid hormone receptor, v-ErbA, and chromatin.
AB - The thyroid hormone receptor and the highly related viral oncoprotein v-erbA are
found exclusively in the nucleus as stable constituents of chromatin. Unlike most
transcriptional regulators, the thyroid hormone receptor binds with comparable
affinity to naked and nucleosomal DNA. In vitro reconstitution experiments and in
vivo genomic footprinting have delineated the chromatin structural features that
facilitate association with the receptor. Chromatin bound thyroid hormone
receptor and v-erbA generate Dnase I hypersensitive sites independent of ligand.
The unliganded thyroid hormone receptor and v-erbA associate with a corepressor
complex containing NCoR, SIN3, and histone deacetylase. The enzymatic activity of
the deacetylase and a chromatin environment are essential for the dominant
repression of transcription by both the unliganded thyroid hormone receptor and v
erbA. In the presence of ligand, the thyroid hormone receptor undergoes a
conformational change that weakens interactions with the corepressor complex
while facilitating the recruitment of transcriptional coactivators such as p300
and PCAF possessing histone acetyltransferase activity. The ligand-bound thyroid
hormone receptor directs chromatin disruption events in addition to histone
acetylation. Thus, the thyroid hormone receptor and v-erbA make very effective
use of their stable association with chromatin and their capacity to alter the
chromatin environment as a major component of the transcription regulation
process. This system provides an exceptionally useful paradigm for investigating
the structural and functional consequences of targeted chromatin modification.
PMID- 10668408
TI - U.S. Food and Drug Administration: future of new product strategies and FDA
priorities.
PMID- 10668409
TI - Neuroprotection against cerebral ischemia. A review of animal studies and
correlation with human trial results.
PMID- 10668410
TI - The pivotal role of iron in NF-kappa B activation and nigrostriatal dopaminergic
neurodegeneration. Prospects for neuroprotection in Parkinson's disease with iron
chelators.
AB - R-Apomorphine (APO) the catechol-derived dopamine D1-D2 receptor agonist has been
shown to be highly potent iron chelator and radical scavenger and inhibitor of
membrane lipid peroxidation in vitro, in vivo and in cell culture employing PC12
cells. Its potency has been compared to the prototype iron chelator
desferrioxamine (desferal), dopamine, nifedipine and dopamine D2 receptor
agonists, bromocriptine, lisuride, pergolide and pramipexole. APO also inhibits
brain and mitochondrial protein oxidation. In vivo APO protects against MPTP (N
methyl-4-phenyl-1,2,3,6-tetrahydropyridine)- induced striatal dopaminergic
neurodegeneration in C57 black mice with as low as 5 mg/kg. APO is a reversible
competitive inhibitor of monoamine oxidase (MAO) A and B with IC50 values of 93
and 214 uM, respectively. The iron chelating and radical scavenging actions of
desferal and APO explains their ability to inhibit iron and 6-hydroxydopamine (6
OHDA)-induced neurodegeneration and activation of redox-sensitive transcription
factor NF-kappa B and the subsequent transactivation of promoters of genes
involved in inflammatory cytokines. Iron is thought to play a pivotal role in
neurodegeneration, and APO may be an ideal drug to investigate neuroprotection in
Parkinson's disease where iron and oxidative stress have been implicated in the
pathogenesis of nigrostriatal dopamine neuron degeneration.
PMID- 10668411
TI - Hypothermia-induced ischemic tolerance.
AB - Delayed resistance to ischemic injury can be induced by a variety of conditioning
stimuli. This phenomenon, known as delayed ischemic tolerance, is initiated over
several hours or a day, and can persist for up to a week or more. The present
paper describes recent experiments in which transient hypothermia was used as a
conditioning stimulus to induce ischemic tolerance. A brief period of hypothermia
administered 6 to 48 hours prior to focal ischemia reduces subsequent cerebral
infarction. Hypothermia-induced ischemic tolerance is reversed by 7 days
postconditioning, and is blocked by the protein synthesis inhibitor anisomycin.
Electrophysiological studies utilizing in vitro brain slices demonstrate that
hypoxic damage to synaptic responses is reduced in slices prepared from
hypothermia-preconditioned animals. Taken together, these findings indicate that
transient hypothermia induces tolerance in the brain parenchyma, and that
increased expression of one or more gene products contributes to this phenomenon.
Inasmuch as hypothermia is already an approved clinical procedure for
intraischemic and postischemic therapy, it is possible that hypothermia could
provide a clinically useful conditioning stimulus for limiting injury elicited by
anticipated periods of ischemia.
PMID- 10668412
TI - A double-blind, placebo-controlled study of the safety, tolerability and
pharmacokinetics of CP-101,606 in patients with a mild or moderate traumatic
brain injury.
AB - CP-101,606 is a postsynaptic antagonist of the glutamate-mediated NR2B subunit of
the N-methyl-D-aspartate (NMDA) receptor. When administered intravenously (i.v.)
at the time of injury, CP-101,606 is neuroprotective in animal models of
traumatic brain injury (TBI) and ischemia. Minimal adverse effects have been
observed in normal human volunteers given i.v. doses of up to 3 mg/kg/hr for 72
hours. The objective of the present clinical trial was to assess the safety,
pharmacokinetics, and tolerability of CP-101,606 infused for various times in
patients who had suffered either an acute moderate or mild TBI (Glasgow Coma
Score 9-14) or hemorrhagic stroke. Patients began receiving treatment within 12
hours of brain injury. A total of 53 subjects (45 with TBI and 8 with stroke)
were randomized in a double-blind fashion to receive CP-101,606 or placebo (4
drug: 1 placebo). Drug/placebo was administered by i.v. infusion (0.75 mg/kg/hr)
for 2 hours and then stopped (n = 25) or continued for 22 hours (n = 4) or 70
hours (n = 24) at a rate of 0.37 mg/kg/hr. Mean plasma drug concentrations were
well above the predicted therapeutic concentration of 200 ng/ml within two hours
of initiating treatment and were sustained as long as drug was infused. All the
patients tolerated their drug/placebo treatment, and there were no clinically
significant cardiovascular or hematological abnormalities in either group. A
Neurobehavioral Rating Scale, used to detect personality changes and behavioral
disturbances, indicated that all subjects showed an improvement from their
postinjury, predosing baseline but did not significantly differ from each other
with respect to type of head injury and/or treatment with drug or placebo.
Modified Kurtzke Scoring also showed a similar pattern of improvement
irrespective of type of head injury or drug/placebo treatment. This study
suggests that CP-101,606, infused for up to 72 hours has no psychotropic effects
and is well-tolerated in patients who have sustained a mild or moderate TBI or
hemorrhagic stroke.
PMID- 10668413
TI - An open-label study of CP-101,606 in subjects with a severe traumatic head injury
or spontaneous intracerebral hemorrhage.
AB - CP-101,606 is a postsynaptic antagonist of N-methyl-D-aspartate (NMDA) receptors
bearing the NR2B subunit. When administered intravenously (i.v.), it decreases
the effects of traumatic brain injury (TBI) and focal ischemia in animal models.
Therapeutic plasma concentrations (200 ng/ml) in animals, have been well
tolerated in healthy human volunteers. The purpose of the present dose escalation
study was to assess the safety, tolerability, and pharmacokinetics of CP-101,606
in subjects who had suffered either an acute severe TBI (Glasgow Coma Scale 3-8)
or spontaneous intracerebral hemorrhage. Thirty patients, 20 with a TBI and 10
with a stroke, were enrolled in the trial and began receiving an i.v. infusion of
CP-101,606 for 2 hours, 24 hours, or 72 hours within 12 hours of brain injury.
For the first two hours, the drug was given a rate of 0.75 mg/kg/hr and then
stopped (n = 17) or continued for 22 (n = 2) or 70 hours (n = 11) at 0.37
mg/kg/hr. Plasma and cerebrospinal fluid (CSF) were collected at serial times
during and after treatment. There were no consistent changes in blood pressure or
pulse nor any clinically significant hematological or electrocardiogram (ECG)
abnormalities attributable to CP-101,606. No adverse events or behavioral changes
were considered to be related to the drug. Plasma concentrations of CP-101,606
over 200 ng/ml were rapidly achieved in the blood and CSF within two hours and
were sustained there as long as the drug was infused. CSF concentrations were
slightly higher than that in plasma by the end of infusion suggesting good
penetration of CP-101,606 into the CSF. Outcome in the severe TBI patients, as
measured by the Glasgow Outcome Score at six months, suggested that a two-hour
infusion yielded a range of scores similar to contemporary patients with a severe
TBI treated at our hospital while the outcomes of the patients treated with
either a 24- or 72-hour infusion were better on average. Thus, these results
indicate that CP-101,606 infused for up to 72 hours is well tolerated, penetrates
the CSF and brain, and may improve outcome in the brain-injured patient.
PMID- 10668414
TI - Neuroprotective "agents" in surgery. Secret "agent" man, or common "agent"
machine?
AB - The search for clinically-effective neuroprotective agents has received enormous
support in recent years--an estimated $200 million by pharmaceutical companies on
clinical trials for traumatic brain injury alone. At the same time, the
pathophysiology of brain injury has proved increasingly complex, rendering the
likelihood of a single agent "magic bullet" even more remote. On the other hand,
great progress continues with technology that makes surgery less invasive and
less risky. One example is the application of endovascular techniques to treat
coronary artery stenosis, where both the invasiveness of sternotomy and the
significant neurological complication rate (due to microemboli showering the
cerebral vasculature) can be eliminated. In this paper we review aspects of
intraoperative neuroprotection both present and future. Explanations for the slow
progress on pharmacologic neuroprotection during surgery are presented. Examples
of technical advances that have had great impact on neuroprotection during
surgery are given both from coronary artery stenosis surgery and from surgery for
Parkinson's disease. To date, the progress in neuroprotection resulting from such
technical advances is an order of magnitude greater than that resulting from
pharmacologic agents used during surgery. The progress over the last 20 years in
guidance during surgery (CT and MRI image-guidance) and in surgical access
(endoscopic and endovascular techniques) will soon be complemented by advances in
our ability to evaluate biological tissue intraoperatively in real-time. As an
example of such technology, the NASA Smart Probe project is considered. In the
long run (i.e., in 10 years or more), pharmacologic "agents" aimed at the complex
pathophysiology of nervous system injury in man will be the key to true
intraoperative neuroprotection. In the near term, however, it is more likely that
mundane "agents" based on computers, microsensors, and microeffectors will be the
major impetus to improved intraoperative neuroprotection.
PMID- 10668415
TI - Brain adenosine receptors as targets for therapeutic intervention in
neurodegenerative diseases.
AB - Adenosine acts as a neurotransmitter in the brain through the activation of four
specific G-protein-coupled receptors (the A1, A2A, A2B, and A3 receptors). The A1
receptor has long been known to mediate neuroprotection, mostly by blockade of
Ca2+ influx, which results in inhibition of glutamate release and reduction of
its excitatory effects at a postsynaptic level. However, the development of
selective A1 receptor agonists as antiischemic agents has been hampered by their
major cardiovascular side effects. More recently, apparently deleterious effects
have been reported following the activation of other adenosine receptor subtypes,
namely, the A2A and the A3 receptors. In particular, selective A2A receptor
antagonists have been demonstrated to markedly reduce cell death associated with
brain ischemia in the rat, suggesting that the cerebral A2A receptor may indeed
contribute to the development of ischemic damage. The beneficial effects evoked
by A2A antagonists may be due to blockade of presynaptic A2A receptors (which are
stimulatory on glutamate release) and/or to inhibition of A2A receptor-mediated
activation of microglial cells. Even more puzzling data have been reported for
the A3 receptor subtype, which can indeed mediate both cell protection and cell
death, simply depending upon the degree of receptor activation and/or specific
pathophysiological conditions. In particular, a mild subthreshold activation of
this receptor has been associated with a reinforcement of the cytoskeleton and
reduction of spontaneous apoptosis, which may play a role in "ischemic
preconditioning" of the brain, according to which a short ischemic period may
protect the brain from a subsequent, sustained ischemic insult that would be
lethal. In contrast, a robust and prolonged activation of the A3 receptor has
been shown to trigger cell death by either necrosis or apoptosis. Such apparently
opposing actions may be reconciled by hypothesizing that adenosine-mediated cell
killing during ischemia may be aimed at isolating the most damaged areas to favor
those parts of the brain that still retain a chance for functional recovery. In
fact, both A3 receptor-mediated cell death and A2A receptor-mediated actions may
be viewed as an attempt to selectively kill irreversibly damaged cells in the
"core" ischemic area, in order to save space and energy for the surrounding live
cells in the "pneumbra" area. Hence, the pharmacological modulation of the A2A
and A3 receptors via selective ligands may represent a novel strategy in the
therapeutic approach to pathologies characterized by acute or chronic
neurodegenerative events.
PMID- 10668416
TI - Stimulation of adenosine A3 receptors in cerebral ischemia. Neuronal death,
recovery, or both?
AB - The role of the adenosine A3 receptor continues to baffle, and, despite an
increasing number of studies, the currently available data add to, rather than
alleviate, the existing confusion. The reported effects of adenosine A3 receptor
stimulation appear to depend on the pattern of drug administration (acute vs.
chronic), dose, and type of the target tissue. Thus, while acute exposure to A3
receptor agonists protects against myocardial ischemia, it is severely damaging
when these agents are given shortly prior to cerebral ischemia. Mast cells
degranulate when their A3 receptors are stimulated. Degranulation of neutrophils
is, on the other hand, impaired. While reduced production of reactive nitrogen
species has been reported following activation of A3 receptors in collagen
induced arthritis, the process appears to be enhanced in cerebral ischemia.
Indeed, immunocytochemical studies indicate that both pre- and postischemic
treatment with A3 receptor antagonist dramatically reduces nitric oxide synthase
in the affected hippocampus. Even more surprisingly, low doses of A3 receptor
agonists seem to enhance astrocyte proliferation, while high doses induce their
apoptosis. This review concentrates on the studies of cerebral A3 receptors and,
based on the available evidence, discusses the possibility of adenosine A3
receptor serving as an integral element of the endogenous cerebral
neuroprotective complex consisting of adenosine and its receptors.
PMID- 10668417
TI - Excitotoxicity, oxidative stress, and the neuroprotective potential of melatonin.
AB - The brain consumes large quantities of oxygen relative to its contribution to
total body mass. This, together with its paucity of oxidative defense mechanisms,
places this organ at risk for damage mediated by reactive oxygen species. The
pineal secretory product melatonin possesses broad-spectrum free radical
scavenging and antioxidant activities, and prevents kainic acid-induced neuronal
lesions, glutathione depletion, and reactive oxygen species-mediated apoptotic
nerve cell death. Melatonin's action is thought to involve electron donation to
directly detoxify free radicals such as the highly toxic hydroxyl radical, which
is a probable end-product of the reaction between NO. and peroxynitrite.
Moreover, melatonin limits NO.-induced lipid peroxidation, inhibits cerebellar
NO. synthase, scavenges peroxynitrite, and alters the activities of enzymes that
improve the total antioxidative defense capacity of the organism. Melatonin
function as a free radical scavenger and antioxidant is likely facilitated by the
ease with which it crosses morphophysiological barriers, e.g., the blood-brain
barrier, and enters cells and subcellular compartments. Pinealectomy, which
eliminates the nighttime rise in circulating and tissue melatonin levels, worsens
both reactive oxygen species-mediated tissue damage and brain damage after focal
cerebral ischemia and excitotoxic seizures. That melatonin protects against
hippocampal neurodegeneration linked to excitatory synaptic transmission is fully
consistent with the last study. Conceivably, the decreased melatonin secretion
that is documented to accompany the aging process may be exaggerated in
populations with dementia.
PMID- 10668418
TI - Neuroprotective role of melatonin in methamphetamine- and 1-methyl-4-phenyl
1,2,3,6-tetrahydropyridine-induced dopaminergic neurotoxicity.
PMID- 10668419
TI - Neuroprotective and cognitive enhancing effects of novel small peptides.
PMID- 10668420
TI - Estrogens: neuroprotective or neurotoxic?
AB - The present paper reviews the major modes of action of estrogen on the molecular,
cellular, tissue, and neurobehavioral levels of mammalian physiology, with an
emphasis on the brain as an estrogen target tissue. We draw a distinction between
receptor- and nonreceptor-mediated actions, as well as delineate the range of
different signal transduction pathways that might be available within a given
tissue to mediate estrogenic effects. We consider species differences relevant to
understanding the predictability of effects in humans from data obtained in rats
or monkeys. Finally, we emphasize the importance of developmental stage in
determining whether estrogenic effects are beneficial or harmful;
"neuroprotective" or "neurotoxic."
PMID- 10668421
TI - Role of glycemia in acute spinal cord injury. Data from a rat experimental model
and clinical experience.
AB - While experimental and clinical evidence indicates that in brain injury blood
glucose increases with injury severity and hyperglycemia worsens neurological
outcome, the role of blood glucose in secondary mechanisms of neuronal damage
after acute spinal cord injury has not yet been investigated. Data from spinal
cord ischemia models suggests a deleterious effect of hyperglycemia, likely due
to enhanced lactic acidosis, which is primarily dependent on the amount of
glucose available to be metabolized. The purpose of this study is to summarize
preliminary experimental and clinical observations on the role of blood glucose
in acute spinal cord injury. Between 1995 and 1996 we used the New York
University (NYU) rat spinal cord injury model to test the following hypotheses:
1) Blood glucose levels increase with injury severity. 2) Fasting protects from
hyperglycemia and prevents secondary damage to the spinal cord. 3) Postinjury
induced hyperglycemia (dextrose 5% 2 gm/Kg) enhances spinal lesion volume. From a
clinical perspective, we reviewed blood glucose records of 47 patients admitted
to the Department of Neurosrgery in Verona, between 1991 and 1995, within 24
hours of acute spinal cord injury in order to determine: a) the incidence of
hyperglycemia (> 140 mg/dl); b) the correlation between blood glucose and injury
severity; and c) the role of methylprednisolone in affecting blood glucose.
Results indicate that in a graded spinal cord injury model: 1) Early after
injury, more severe contusions support significantly higher blood glucose levels.
2) Fasting overnight does not directly affect spinal cord lesion volume but
influences blood gases, and we observed that a slightly systemic acidosis plays a
minor neuroprotective role. Fasting also ensures more consistent normoglycemic
baseline blood glucose values. 3) Postinjury-induced moderate hyperglycemia (160
190 mg/dl) does not significantly affect spinal cord injury. In the clinical
study, we observed that during the first 24 hours after spinal cord injury: a)
Glycemia ranges between 90 and 243 mg/dl (mean value 143 mg/dl), and close to 50%
of the patients present blood glucose values higher than normal. b)
Methylprednisolone administration is not associated to significantly higher blood
glucose levels. c) There is a trend for larger glucose rises with more severe
injury.
PMID- 10668422
TI - N-acetylserotonin, melatonin and their derivatives improve cognition and protect
against beta-amyloid-induced neurotoxicity.
AB - After a single injection of cholinergic neurotoxin ethylcholine aziridinium
(AF64A, 3 nmol intracerebroventricularly (i.c.v.)), rats failed to perform the
tasks in the active avoidance (learning and retention paradigms) and water maze
tests. N-Acetylserotonin (NAS), melatonin and their newly synthesized
derivatives, CA-15 and CA-18, (0.3-3.0 mg/kg daily for 12-14 days) reversed the
effect of AF64A in a dose-dependent manner with CA-18 being the most active.
Melatonin and NAS caused sedation absent in CA-18-treated rats. The studied
compounds (25-500 microM for 72 hr) protected against beta-amyloid peptide (beta
AP) fragment 25-35-induced neurotoxicity in cerebellar granule cell culture. Our
results suggest that neuroprotecting properties of these compounds might mediate
their cognition-enhancing effects. The results obtained warrant the further
search for the novel types of safe neuroprotectors among the synthetic
NAS/melatonin derivatives.
PMID- 10668423
TI - Neuroprotective action of bilirubin against oxidative stress in primary
hippocampal cultures.
PMID- 10668425
TI - Primary cultures of rat cerebellar granule cells as a model to study neuronal 5
lipoxygenase and FLAP gene expression.
AB - Aging is associated with chronic neurodegenerative diseases and increased brain
vulnerability that may lead to a worse outcome from brain insults in elderly than
in young subjects. Inflammation is one of the patholphysiological mechanisms of
both chronic and acute neurodegeneration. Leukotrienes are inflammatory lipid
mediators whose formation from arachidonic acid is initiated by 5-lipoxygenase (5
LO). 5-LO is also expressed in neurons and can be activated by brain injuries,
whereas 5-LO inhibitors can provide neuroprotection. The expression of the 5-LO
gene appears to be inhibited by the pineal hormone, melatonin, and stimulated by
stress hormone glucocorticoids (e.g., corticosterone and the synthetic
glucocorticoid dexamethasone). Melatonin deficiency and hyperglucocorticoidemia
frequently develop with aging. We found that old or pinealectomized, i.e.,
melatonin-deficient rats are more susceptible to kainate-triggered excitotoxic
limbic brain injury than the corresponding young or sham-pinealectomized
controls, and that pinealectomy, aging, or glucocorticoid treatment result in an
enhanced expression of 5-LO in limbic structures. We hypothesize that an aging
brain is at a higher risk of neurodegeneration via aging-suppressed melatonin
secretion and/or aging-increased glucocorticoid secretion and the resultant
upregulation of 5-LO expression. Furthermore, we propose that suppressing the 5
LO expression and/or activity will increase the brain's resistance to injury. The
results of our ongoing research are expected to elucidate the role of 5-LO in
aging and neurodegeneration and to indicate neuroprotective therapies that would
target the 5-LO pathway.
PMID- 10668424
TI - Protective effect of L-carnitine in the neurotoxicity induced by the
mitochondrial inhibitor 3-nitropropionic acid (3-NPA).
PMID- 10668426
TI - Intraneuronal ion distribution during experimental oxygen/glucose deprivation.
Routes of ion flux as targets of neuroprotective strategies.
AB - Ischemic neuronal injury appears to be mediated by disruption of subcellular ion
distribution and, therefore, prevention of ion relocation might be
neuroprotective. X-ray microanalysis was used to measure concentrations of Na, K,
Ca and other elements in subcellular compartments (e.g., mitochondria) of CA1
neurons from oxygen/glucose-deprived (OGD) hippocampal slices. Results showed
that OGD produced progressive loss of ion regulation in CA1 cells. Post-OGD
reperfusion with normal media exacerbated the initial ion deregulation. To study
neuroprotective mechanisms, we determined the ability of hypothermia (31 degrees
C) or ion channel blockade to retard intraneuronal ion disruption induced by
OGD/reperfusion. Whereas Ca2+ channel blockade (omega-conotoxin MVIIC, 3 microM)
was ineffective, hypothermia and Na+ channel blockers (tetrodotoxin, TTX, 1
microM; lidocaine, 200 microM) reduced ion deregulation in subneuronal
compartments. Blockade of glutamate receptors (AMPA, 10 microM; the non-NMDA
receptor antagonist CNQX, 10 microM/100 microM glycine; the NMDA receptor
antagonist CCP, 100 microM) during OGD/reperfusion provided nearly complete
protection. These findings provide a foundation for identifying potential
pharmacotherapeutic approaches and for discerning corresponding mechanisms of
neuroprotection.
PMID- 10668427
TI - Matrix remodeling after stroke. De novo expression of matrix proteins and
integrin receptors.
AB - Following an ischemic insult to the central nervous system a reorganization of
cells and tissue takes place as the surrounding cells attempt to limit the
injury, repair the damage, and restore normal architecture of the brain. This
tissue remodeling requires de novo synthesis of genes and proteins which enables
cells to actively change their relationship with the existing extracellular
matrix and with other cells to reorganize the damaged tissue. We have identified
two key molecular components of the matrix remodeling process after focal
ischemia: osteopontin (OPN) and its integrin receptor alpha v beta 3 (alpha v
beta 3). OPN is initially expressed by activated macrophages and microglia in the
periinfarct region (24-48 hr) and at later times (5-15 days) in the core infarct.
After focal stroke the alpha v beta 3 was upregulated by astrocytes in the
periinfarct region. Spatial and temporal analyses demonstrated that at 5 days
after injury the alpha v beta 3-positive astrocytes were at a distance from the
osteopontin-expressing macrophages; by 15 days the alpha v beta 3-expressing
astrocytes were localized within an osteopontin-rich matrix. In vitro OPN was
shown to induce migration of astrocytes in a Boyden chamber system. These data
suggest that OPN derived from microglia at the infarct border zone (and possible
macrophages in the infarct core) may serve as an "astrokine" (suggested term for
astrocyte chemoattractant) to organize the astrocyte scar after focal stroke. Our
data demonstrate profound changes in brain matrix remodeling after focal ischemic
stroke, including the synthesis and release of matrix proteins alien to the
normal brain, the expression of integrin receptors that ligate these proteins,
and possibly a novel function for microglial-derived OPN in astrocyte migration
after focal ischemia that may drive glial activation, organization, and repair
functions.
PMID- 10668428
TI - Metallothioneins attenuate methylmercury-induced neurotoxicity in cultured
astrocytes and astrocytoma cells.
AB - Metallothionein-I (MT-I) was expressed in neonatal rat primary astrocyte cultures
and an astrocytoma cell line by pGFAP-MT-I plasmid transfection under the control
of the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter.
Following transient transfection of the pGFAP-MT-I plasmid, MT-I mRNA and MT-I
protein levels were determined by Northern blot and immunoprecipitation analyses,
respectively. The ability of cells overexpressing MT-I to withstand acute
methylmercury (MeHg) treatment was measured by the release of preloaded
Na2(51)CrO4, an indicator of membrane integrity. Transfection with the pGFAP-MT-I
plasmid led to increased mRNA (2.5-fold in astrocytes and 7.4-fold in
astrocytomas) and MT-I protein (2.4-fold in astrocytes and 4.0-fold in
astrocytomas) levels compared with their respective controls. Increased
expression of MT-I was associated with attenuated release of Na2(51)CrO4 upon
MeHg (5 microM) treatment. These results demonstrate that MT-I can be highly
expressed both in primary astrocyte cultures and astrocytomas by pGFAP-MT-I
plasmid transfection, and lend credence to the hypothesis that increased
expression of MT-I affords protection against the cytotoxic effects of MeHg.
Taken together, the data suggest that MTs offer effective cellular adaptation of
MeHg cytotoxicity.
PMID- 10668429
TI - Implication of poly (ADP-ribose) polymerase (PARP) in neurodegeneration and brain
energy metabolism. Decreases in mouse brain NAD+ and ATP caused by MPTP are
prevented by the PARP inhibitor benzamide.
AB - Poly(ADP-ribose) polymerase (PARP) is a DNA binding protein that uses
nicotinamide adenine dinucleotide (NAD+) as a substrate. Evidence from in vitro
studies on nonneuronal cells in culture have shown that when fully activated by
free radical-induced DNA damage, PARP depletes cellular NAD+ and consequently
adenosine triphosphate (ATP) levels within a matter of minutes, and that this
depletion is associated with a cell death that can be prevented by PARP
inhibitors. The present in vivo study utilized the 1-methyl-4-phenyl-1,2,3,6
tetrahydropyridine (MPTP)-treated mouse, a model of central nigrostriatal
dopamine neurotoxicity that recapitulates certain features of Parkinson's disease
(PD), and one in which we have previously shown PARP inhibitors to be protective,
to examine whether MPTP acutely caused region- and time-dependent changes in
levels of NAD+ and ATP in the brain in vivo and whether such effects were
modified by treatments with neuroprotective doses of the PARP inhibitor
benzamide. The results confirm that MPTP reduces striatal ATP levels, as
previously reported by Chan et al., show that MPTP causes a regionally-selective
(striatal and midbrain) loss of NAD+, and indicate that the PARP inhibitor
benzamide can prevent these losses without interfering with MPTP-induced striatal
dopamine release. These findings suggest an involvement of PARP in the control of
brain energy metabolism during neurotoxic insult, provide further evidence in
support of the participation of PARP in MPTP-induced neurotoxicity in vivo and
suggest that PARP inhibitors might be beneficial in the treatment of PD.
PMID- 10668430
TI - Neuroprotection against ischemia by metabolic inhibition revisited. A comparison
of hypothermia, a pharmacologic cocktail and magnesium plus mexiletine.
AB - Previous studies have suggested that metabolic inhibition is neuroprotective, but
little evidence has been provided to support this proposal. Using the in vitro
rabbit retina preparation as an established model of the central nervous system
(CNS), we measured the rate of glucose utilization and lactate production, and
the light-evoked compound action potentials (CAPs) as indices of neuronal energy
metabolism and electrophysiologic function, respectively. We examined the effect
of three (3) treatments options: hypothermia (i.e., 33 degrees C and 30 degrees
C), a six-member pharmacologic "cocktail" (tetrodotoxin (0.1 microM), 2-amino-4
phosphonobutyric acid (20 microM), 2-amino-5-phosphonovaleric acid (1 mM),
amiloride (1 mM), magnesium (10 mM) and lithium (10 mM) and the combination of
magnesium (Mg2+ 1 mM) and mexiletine (Mex, 300 microM) on in vitro rabbit
retinas, to see if there is a correlation between neuronal energy metabolism
during ischemia (simulated by the reduction of oxygen from 95% to 15% and glucose
from 6 mM to 1 mM), and the subsequent recovery of function. Hypothermia and the
"cocktail" significantly inhibited both the rate of glucose utilization and
lactate production, whereas Mg2+ and/or Mex showed only a nonsignificant tendency
toward a reduction, compared to control retinas. Recovery of light-evoked CAPs
was significantly improved in hypothermia- and cocktail-treated retinas, as well
as with retinas exposed to the combination of Mg2+ plus Mex, but not with Mg2+ or
Mex alone, relative to control retinas. A linear regression analysis of the %
recovery of function versus the % reduction in the rate of glucose utilization
during ischemia showed a significant correlation (r2 = 0.80, correlation
coefficient = 0.9, p < 0.05) between these two parameters. This and other data
discussed provide convincing evidence that there is a correlation between
metabolic inhibition, achieved during ischemia, and neuroprotection.
PMID- 10668431
TI - Calpeptin and methylprednisolone inhibit apoptosis in rat spinal cord injury.
AB - Intracellular free Ca2+ and free radicals are increased following spinal cord
injury (SCI). These can activate calpain to degrade cytoskeletal proteins leading
to apoptotic and necrotic cell death. Primary injury triggers a cascade of
secondary injury, which spreads to rostral and caudal areas. We tested calpain
involvement in apoptosis in five 1-cm segments of rat spinal cord with injury (40
g-cm) induced at T12 by weight-drop. Animals were immediately treated with
calpeptin (250 micrograms/kg) and methylprednisolone (165 mg/kg) and sacrificed
at 48 hr. Untreated SCI rats manifested 68-kD neurofilament protein (NFP)
degradation (indicating calpain activity), and internucleosomal DNA fragmentation
(indicating apoptosis). Both calpain activity and apoptosis were highest in the
lesion, and decreased with increasing distance from the lesion. Treatment
decreased 68-kD NFP degradation with reduction in apoptosis in all five areas.
Thus, calpeptin and methylprednisolone are found to be neuroprotective in SCI.
PMID- 10668432
TI - Calpastatin is upregulated and acts as a suicide substrate to calpains in
neonatal rat hypoxia-ischemia.
PMID- 10668433
TI - High extracellular glutamate and neuronal death in neurological disorders. Cause,
contribution or consequence?
AB - In models of neurological disorders, increased extracellular glutamate and
beneficial effects produced by glutamate-receptor antagonists are consistently
taken as supporting evidence of excitotoxicity. This systematic interpretation is
over-simplified and potentially misleading. High extracellular glutamate is not a
reliable indicator of endogenous excitotoxicity, i.e., the intrinsic, potential
neurotoxicity of endogenous glutamate whenever it accumulates extracellularly.
Firstly, because the extracellular levels of glutamate necessary to produce
depolarization and death in vivo, are far above those measured in models of
neurological disorders. Secondly, because changes in the concentration of
glutamate in the synaptic cleft (i.e., the relevant compartment for endogenous
excitotoxicity) are not reflected extracellularly. Protection by glutamate
receptor antagonists does not necessarily imply inhibition of excitotoxic
abnormalities. Indeed, neuronal death initiated by insults such as ischemia
results from multifactorial processes that may be interrelated. Therefore,
beneficial effects resulting from an interaction with glutamate-mediated
transmission may actually render the cell more resistant to other deleterious
mechanisms (e.g., mitochondrial injury, oxidative stress).
PMID- 10668434
TI - Evidence disputing the importance of excitotoxicity in hippocampal neuron death
after experimental traumatic brain injury.
AB - The hippocampus is selectively vulnerable to experimental traumatic brain injury
(TBI). Beneficial effects of glutamate receptor antagonists and increased
extracellular levels of glutamate have suggested that glutamate-mediated
excitotoxicity may be responsible for this selective damage. In order to clarify
this important issue, we applied a severe parasagittal fluid percussion injury
(FPI) to strains of mice shown to be susceptible and resistant to kainic acid
(KA)-induced excitotoxic hippocampal damage. Dystrophic neurons were present by
10 min after FPI in the hippocampi of both strains. Damaged hippocampal neurons
were absent at 4 days and 7 days. Additionally, there was no significant
difference (p = 1.00) in CA3 neuron survival between KA-susceptible and
resistant mice at 4 days. In conclusion, excitotoxicity does not significantly
contribute to hippocampal neuron loss after FPI and, in contrast to classic
studies of excitotoxicity in vivo, the pattern of hippocampal cell death after
TBI is extremely acute.
PMID- 10668435
TI - Neuroprotective properties of nitric oxide.
AB - The discoveries of physiological roles of nitric oxide (.NO) as the mediator of
endothelium-derived relaxing factor (EDRF) action and the activator of guanylyl
cyclase to increase cyclic guanosine monophosphate (cGMP), which lead to
vasorelaxation in the cardiovascular system, have been awarded with the 1998
Nobel Prize of Medicine. The present review discusses putative beneficial effects
of .NO in the central nervous system (CNS). In addition to its prominent roles of
the regulation of cerebral blood flow and the modulation of cell to cell
communication in the brain, recent in vitro and in vivo results indicated that
.NO is a potent antioxidative agent. .NO terminates oxidant stress in the brain
by (i) suppressing iron-induced generation of hydroxyl radicals (.OH) via the
Fenton reaction, (ii) interrupting the chain reaction of lipid peroxidation,
(iii) augmenting the antioxidative potency of reduced glutathione (GSH) and (iv)
inhibiting cysteine proteases. It is apparent that .NO--a relative long half-life
nitrogen-centered weak radical--scavenges those short-lived, highly reactive free
radicals such as superoxide anion (O2.-), .OH, peroxyl lipid radicals (LOO.) and
thiyl radicals (i.e., GS.), yielding reactive nitrogen species including
nitrites, nitrates, S-nitrosoglutathione (GSNO) and peroxynitrite (ONOO-). GSNO
is 100-fold more potent than GSH; it completely inhibits the weak peroxidative
effect of ONOO-. Moreover, CO2 and .NO neutralize prooxidative effects of ONOO-.
CO2 prevents protein oxidation but not 3-nitrotyrosine formation caused by ONOO-.
Finally, neuroprotective effects of GSNO and .NO have been demonstrated in brain
preparations in vivo. These novel neuroprotective properties of .NO and GSNO may
have their physiological significance, since oxidative stress depletes GSH while
increasing GS. and .NO formation in astroglial and endothelial cells, resulting
in the generation of a more potent antioxidant GSNO and providing additional
neuro-protection at microM concentrations. This putative GSNO pathway (GSH-->GS.-
>GSNO-->.NO + GSSG-->GSH) may be an important part of endogenous antioxidative
defense system, which could protect neurons and other brain cells against
oxidative stress caused by oxidants, iron complexes, proteases and cytokines. In
conclusion, .NO is a potent antioxidant against oxidative damage caused by
reactive oxygen species, which are generated by Fenton reaction or other
mechanisms in the brain via redox cycling of iron complexes.
PMID- 10668436
TI - Neuroprotective strategies for HIV-1-associated neurologic disease.
PMID- 10668437
TI - Changes in mRNA levels for heat-shock/stress proteins (Hsp) and a secretory
vesicle associated cysteine-string protein (Csp1) after amphetamine (AMPH)
exposure.
AB - Damage to nerve terminals, reactive gliosis and somatic degeneration can result
when pronounced hyperthermia occurs during amphetamine (AMPH) exposure. The
effects of AMPH-induced hyperthermia and damage on the relative mRNA levels for
several heat shock/stress proteins (Hsp27, Hsp60, Hsp70 and Hsc70), as well as
secretory vesicle associated cysteinestring protein (Csp1) were determined in
both the striatum and substantia nigra using reverse transcriptase polymerase
chain reaction (RT-PCR). These changes were compared to changes in Hsp mRNA
levels seen in primary rat cerebral astrocyte cultures after heat shock/stress.
Striatal Hsp70 mRNA increased about 2-fold over control levels at 16 hr after
AMPH-induced hyperthermia, and was the only Hsp species to significantly increase
in response to AMPH. Hsp70 mRNA levels returned to control within 14 days after
AMPH. Two-fold increases in Hsp70 mRNA were also seen in primary cultures of rat
cerebrum 24 hr after heat shock. In primary cultures and brain tissue, the
increased Hsp70 mRNA levels were still more than 500-fold less than constitutive
Hsc70 mRNA and 50-fold less than Hsp60 levels. Hsp27 mRNA was not present in the
striatum, nigra and primary cell cultures. Thus, the expression of Hsp species
mRNA measured was very similar in brain tissue and primary cell cultures. Because
only a modest induction of Hsp 70 mRNA occurred, the Hsp species evaluated may
only play a minor role in AMPH neurotoxicity. However, further studies are
necessary to determine whether large increases in Hsp70 are occurring in selected
neurons or glia in the striatum. RT-PCR products for Csp1 were produced in total
RNA obtained from brain but not from cultured astrocytes, suggesting that the
Csp1 mRNA measured by RT-PCR is of neuronal origin. Csp1 mRNA levels were acutely
downregulated in neurons in the substantia nigra, possibly in response to damage,
but not the striatum after AMPH exposure. A slight long-term upregulation at 4
months of Csp1 mRNA may occur in the striatum but not in nigra.
PMID- 10668438
TI - Benzamide, a poly(ADP-ribose) polymerase inhibitor, is neuroprotective against
soman-induced seizure-related brain damage.
PMID- 10668439
TI - Central noradrenergic neurotoxicity of DSP4 in mice. Studies on the
neuroprotective potential of the poly(ADP-ribose) polymerase inhibitor,
benzamide.
PMID- 10668440
TI - The antioxidative effect of carboxyfullerenes (C3/D3) on iron-induced oxidative
injury in CNS.
AB - Carboxyfullerenes, including two regioisomers C3 and D3, were investigated as
antioxidants against iron-induced oxidative stress in vivo and in vitro. Both C3
and D3 dose-dependently inhibited autoxidation and iron-elevated lipid
peroxidation in cortical homogenates. The antioxidative property of C3 was
compared to Trolox (a water-soluble analogue of vitamin E) and glutathione. C3
was more effective than glutathione but was less effective than Trolox in
inhibiting iron-induced elevation in lipid peroxidation. In urethane-anesthetized
rats, intranigral infusion of iron degenerated the nigrostriatal dopaminergic
system, including as elevation in lipid peroxidation in the infused substantia
nigra (SN) and reductions in K(+)-evoked dopamine overflow and dopamine content
in the ipsilateral striatum 7 days after the infusion. Local application of iron
with C3 or D3 prevented iron-induced oxidative injuries. Our data suggest that
carboxyfullerenes have a neuroprotective effect in preventing iron-induced
oxidative injury in CNS.
PMID- 10668441
TI - Neuregulin signaling in brain injury and in animal models of ischemia.
PMID- 10668442
TI - Protective and rescuing abilities of IGF-I and some putative free radical
scavengers against beta-amyloid-inducing toxicity in neurons.
AB - beta-Amyloid (A beta) peptides are most likely involved in the neurodegenerative
process occurring in Alzheimer's Disease (AD) and are enriched in senile plaques.
The mechanisms of A beta toxicity are not clear but likely involve free radicals
and apoptosis. Much interest is currently aiming at developing effective
approaches to block A beta toxicity in order to slow down disease progression. In
that context, we are particularly interested in studying the role of insulin-like
growth factors, particularly IGF-I and purported free radical scavengers
including a Gingko biloba extract (EGb761) as blocker of A beta toxicity in a
simple in vitro model of hippocampal primary cultures. We observed that both IGF
I and EGb761 are unique in that they are able not only to protect but even to
rescue neurons against A beta toxicity. These results are summarized here and
possible mechanisms of action are discussed to explain the protective properties
of these two classes of agents.
PMID- 10668443
TI - The unique histopathological responses of the injured spinal cord. Implications
for neuroprotective therapy.
AB - Tissue destruction at the primary site of a spinal cord injury leads to
persistent necrosis that progressively enlarges the lesion. Steroids attenuate
this necrotizing process and promote tissue repair even though such anti
inflammatory drugs interfere with wound healing in non-CNS organs. To address
this paradox, the spinal cord of rats and mice was crushed extradurally and the
effects of the following anti-inflammatory agents studied by light microscopical
image analysis: allopurinol, aminoguanidine, indomethacin, a bacterial
lipopolysaccharide, naproxen, and pregnenolone. The contribution of Wallerian
degeneration to progressive necrosis was studied in a mutant mouse strain (WldS)
that is characterized by delayed Wallerian degeneration. In rats, the anti
inflammatory agents selectively attenuated progressive necrosis and encouraged
wound healing. In mice, considerable tissue repair occurred without
pharmacological intervention; this wound-healing process was delayed in the
mutant WldS strain. Since spinal cord injury results in concomitant tissue
necrosis and wound healing, a goal of neuroprotective therapy is to regulate the
dynamic balance between these destructive and reparative processes.
PMID- 10668444
TI - Ion channel modulation as the basis for neuroprotective action of MS-153.
AB - MS-153, (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline, is a new neuroprotective
drug. Recent data in the literature suggest that it inhibits glutamate
accumulation occurring during ischemia and the translocation of protein kinase C
gamma (PKC gamma). The present study was undertaken to prove the hypothesis that
MS-153 blocks neuroreceptors and ion channels involved in glutamate accumulation.
Neurons isolated from rat dorsal root ganglia and frontal cortex were used for
recording channel currents by the whole-cell patch clamp technique. The effects
of bath-applied MS-153 were examined on tetrodotoxin-sensitive and tetrodotoxin
resistant sodium channels and high voltage-gated calcium channels of dorsal root
ganglion neurons, and channels activated by glutamate, N-methyl-D-aspartate
(NMDA), kainate, alpha-amino-3-hydroxy-5-methyl-4-isoxarole propionic acid
(AMPA), gamma-aminobutyric acid (GABA) and acetylcholine (ACh) in cortical
neurons. MS-153 at a concentration of 300 microM had no effect on either
tetrodotoxin-sensitive or tetrodotoxin-resistant sodium channels. High voltage
gated calcium channels were either suppressed or not affected by 1-300 microM MS
153. The variable blocking effect of MS-153 was due to the variable activity of
intracellular components in individual neurons, especially that of PKC, whose
translocation is known to be inhibited by MS-153. When 100 nM phorbol 12
myristate-13-acetate (PMA) was applied to neurons, MS-153 suppressed the calcium
channel current more frequently. Calphostin C (0.5 microM), a specific PKC
inhibitor, applied intracellularly via recording patch pipette, completely
abolished MS-153 suppression of the calcium channel current. Currents induced by
glutamate, NMDA, kainate, AMPA, GABA or ACh were not affected by MS-153 at 300
microM. It was concluded that MS-153 inhibited high voltage-gated calcium
channels through interactions with PKC, thereby preventing massive release of
glutamate from nerve terminals in ischemic conditions.
PMID- 10668445
TI - Blockade of NAALADase: a novel neuroprotective strategy based on limiting
glutamate and elevating NAAG.
AB - Excessive glutamate receptor activation is thought to be involved in the neuronal
injury caused by stroke. Based on the hypothesis that N-acetyl-aspartyl-glutamate
(NAAG) is a modulatory neurotransmitter or storage form of glutamate, we have
pursued a novel strategy of therapeutic intervention, blockade of N-acetylated
alpha-linked acidic dipeptidase (NAALADase), the enzyme that hydrolyzes NAAG to
liberate glutamate. Using the suture model of transient middle cerebral artery
occlusion (MCAO) in rats, the prototype NAALADase inhibitor 2
(phosphonomethyl)pentanedioic acid (2-PMPA) dramatically reduced extracellular
glutamate accumulation measured by microdialysis both during a 2-hour occlusion
and during reperfusion, consistent with an effect on glutamate supply. During
reperfusion, the decrease in glutamate was accompanied by an equimolar,
reciprocal rise in extracellular NAAG. NAALADase inhibition may prove to be a
well tolerated therapy for cerebral ischemia. In addition, NAALADase inhibitors
should prove to be important tools in understanding the physiological role of
NAAG in the brain.
PMID- 10668446
TI - The low-affinity, use-dependent NMDA receptor antagonist AR-R 15896AR. An update
of progress in stroke.
AB - Use-dependent N-methyl-D-aspartate (NMDA) receptor antagonists protect neurons
from the lethal consequences of excessive stimulation by excitatory amino acids.
Clinical development of high-affinity compounds such as MK801 have been limited
due to untoward side effects. Toward this end, the lower-affinity use-dependent
NMDA antagonists have greater margins of safety and have advanced to clinical
trials for stroke, epilepsy, head trauma and chronic neurodegenerative disorders.
AR-R 15896AR is currently in Phase II trials for stroke and has been repeatedly
demonstrated to afford neuroprotection in a variety of in vivo and in vitro
models associated with ischemia/excitotoxic conditions.
PMID- 10668447
TI - Intracellular survival pathways against glutamate receptor agonist excitotoxicity
in cultured neurons. Intracellular calcium responses.
AB - Cultured rat cerebellar granule cells are resistant to the excitotoxic effects of
N-methyl-D-aspartate (NMDA) and non-NMDA receptor agonists under three
conditions: 1) prior to day seven in vitro when cultured in depolarizing
concentrations of potassium [25 mM]; 2) at any time in vitro when cultured in non
depolarizing concentrations of potassium 5 mM[; and 3) when neurons, cultured in
depolarizing concentrations of potassium 25 mM[ for eight days in vitro, are
pretreated with a subtoxic concentration of NMDA. The focus of this paper is to
determine: a) whether the resistance to excitotoxicity by NMDA and non-NMDA
receptor agonists is due to a decreased intracellular calcium Ca++[i response to
glutamate receptor agonists in cultured rat cerebellar granule cells; or b)
whether Ca++[i levels induced by the agonists are similar to those observed under
excitotoxic conditions. Granule cells, matured in non-depolarizing growth medium,
treated with glutamate resulted in an increase in Ca++[i followed by a plateau
that remained above baseline in virtually all neurons that responded to
glutamate. The response was rapid in onset (< 10 sec) and the pattern of response
heterogeneous in that cells responsive to glutamate increased their Ca++[i to
different extents; some cells did not respond to glutamate. Kainate also produced
significant elevations in Ca++[i. The Ca++[i response to glutamate in neurons
matured in depolarizing (25 mM K+) growth medium for three days was rapid,
transient and heterogeneous, which reached a plateau that was elevated above
baseline levels; removing the glutamate markedly reduced the Ca++[i
concentration. Activation of the alpha-amino-3-hydroxy-5-methyl-4
isoxazolepropionic acid (AMPA)/kainate receptors by kainic acid produced similar
changes in Ca++[i responses. At a time when cultured cerebellar granule cells
become susceptible to the excitotoxic effects of glutamate acting at NMDA
receptors (day in vitro (DIV) 8) in depolarizing growth medium, glutamate
elicited Ca++[i responses similar to those observed at a culture time when the
neurons are not susceptible to the excitotoxic effects of glutamate (DIV 3).
Pretreatment of the cultured neurons with a subtoxic concentration of NMDA, which
protects all neurons against the excitotoxic effects of glutamate, did not alter
the maximal Ca++[i elicited by an excitotoxic concentration of glutamate.
PMID- 10668449
TI - NPS 1506, a novel NMDA receptor antagonist and neuroprotectant. Review of
preclinical and clinical studies.
AB - NPS 1506 is a moderate affinity, uncompetitive N-methyl-D-aspartate (NMDA)
receptor antagonist. NPS 1506 is neuroprotective in rodent models of ischemic
stroke, hemorrhagic stroke, and head trauma, with a 2-hr window of opportunity.
Neuroprotectant doses of NPS 1506 ranged from approximately 0.1-1.0 mg/kg, with
peak plasma concentrations ranging from 8-80 ng/mL. Even at doses producing
behavioral toxicity, NPS 1506 did not elicit MK-801-like behaviors, did not
generalize to phencyclidine (PCP), and did not elicit neuronal vacuolization. In
a Phase I study, intravenous (i.v.) doses of NPS 1506 from 5-100 mg were well
tolerated and provided plasma concentrations in excess of those required for
neuroprotection in rodents. Adverse events at the 100-mg dose included mild
dizziness and lightheadedness, and mild to moderate ataxia. Neither PCP-like
psychotomimetic effects nor cardiovascular effects were noted. The long plasma
half-life of NPS 1506 (approximately 60 hr) suggests that a single i.v. dose will
provide prolonged neuroprotection in humans.
PMID- 10668448
TI - Neuroprotective actions of novel and potent ligands of group I and group II
metabotropic glutamate receptors.
AB - The role of group I metabotropic glutamate (mGlu) receptors in neurodegeneration
is controversial because of the contradictory effects of mGlu1/5 agonists in in
vitro models of neuronal cell death. In this study, novel and selective
antagonists of mGlu1 and mGlu5: LY367385 and LY367366 were found to show
consistent neuroprotective effects against N-methyl-D-aspartate (NMDA)-induced
excitotoxicity in vitro and in vivo. Furthermore, intraventricular administration
of LY367385 reduced hippocampal cell death in gerbils subjected to transient
global ischemia. Previous studies have also shown that activation of group II
mGlu receptors may contribute to neuroprotective mechanisms in vitro and in vivo.
Three potent group II mGlu agonists--LY354740, LY379268 and LY389795--were found
to attenuate both NMDA excitotoxicity and staurosporine-induced neuronal cell
death. LY354740 and LY379268 were protective against transient global ischemia in
gerbils when dosed intraperitoneally. These results support the view that
antagonists of mGlu1 and mGlu5 and agonists of group II mGlu receptors may be
useful agents in the therapeutic treatment of neurodegenerative disease.
PMID- 10668450
TI - Peroxynitrite scavengers for the acute treatment of traumatic brain injury.
AB - Recent evidence has suggested that the superoxide and nitric oxide-derived
reactive oxygen species peroxynitrite (ONOO-) may play a significant role in the
acute pathophysiology of brain injury. One pharmacological mechanism by which
ONOO(-)-mediated damage might be interrupted is by the administration of
scavenging compounds such as the thiol-containing compound penicillamine. In the
present study, we examined the ability of either penicillamine (Pen) or the more
brain penetrable penicillamine methyl ester (PenME) (0.01, 0.1, 1.0 or 10.0 mg/kg
i.v. 5 min post-injury) to improve the early (1 hr) neurological recovery (grip
score) of male CF-1 mice after a severe (900 g-cm; 50 g x 18 cm) injury. Pen
produced a dose-related improvement in grip score. At 1.0 mg/kg, a +112%
improvement was observed compared to vehicle-treated mice, and at 10.0 mg/kg, the
increase was +168% (both, p < 0.05). PenME more potently improved the 1-hr grip
score, but the magnitude of the optimal effect (+96% at 0.1 mg/kg; p < 0.02) was
no greater than that observed with Pen, which largely remains in the cerebral
microvasculature. These results are consistent with a role of ONOO- in acute head
injury, but suggest that microvascular scavenging may be of primary therapeutic
importance during the early post-traumatic period.
PMID- 10668451
TI - Regional cytokine, cytokine receptor and neuropeptide mRNA changes associated
with behavioral and neuroanatomical abnormalities in persistent, noninflammatory
virus infection of neonatal rats.
PMID- 10668452
TI - Development of a nonhuman primate model for studying the consequences of long
term neuroprotectant administration on complex brain functions in developing
animals.
PMID- 10668453
TI - Melatonin as a pharmacological agent against neuronal loss in experimental models
of Huntington's disease, Alzheimer's disease and parkinsonism.
AB - This review summarizes the experimental findings related to the neuroprotective
role of melatonin. In particular, it focuses on research directed at models of
Huntington's disease, Alzheimer's disease and Parkinsonism. Melatonin has been
shown to be highly effective in reducing oxidative damage in the central nervous
system; this efficacy derives from its ability to directly scavenge a number of
free radicals and to function as an indirect antioxidant. In particular,
melatonin detoxifies the highly toxic hydroxyl radical as well as the peroxyl
radical, peroxynitrite anion, nitric oxide, and singlet oxygen, all of which can
damage macromolecules in brain cells. Additionally, melatonin stimulates a
variety of antioxidative enzymes including superoxide dismutase, glutathione
peroxidase and glutathione reductase. One additional advantage melatonin has in
reducing oxidative damage in the central nervous system is the ease with which to
crosses the blood-brain barrier. This combination of actions makes melatonin a
highly effective pharmacological agent against free radical damage. The role of
physiological levels of melatonin in forestalling oxidative damage in the brain
is currently being tested.
PMID- 10668454
TI - The regulation of cerebral blood flow during intravenous cocaine administration
in cocaine abusers.
AB - Cocaine abuse is associated with heightened risk of life-threatening neurological
complications such as strokes, seizures, and transient ischemic attacks. We used
transcranial Doppler (TCD) sonography, a continuous measure of cerebral blood
flow velocity, to better understand the changes in cerebral hemodynamics produced
by cocaine administration, which may lead to an increased risk for stroke in
cocaine abusers. Heart rate and blood pressure were also measured. Blood flow
velocity of seven cocaine abusers was studied during placebo, 10-, 25-, and 50-mg
intravenous (i.v.) injections of cocaine. A significant increase in mean and
systolic velocity which lasted for about two minutes was observed with all doses
of cocaine, with no change in the placebo condition. This increase in systolic
velocity indicates that cocaine produces an immediate and brief period of
vasoconstriction in large arteries of the brain. The present results elucidate
the time course of cocaine's acute cerebrovascular effects and provide a better
understanding of etiology of cocaine-related stroke and transient ischemic
attacks.
PMID- 10668455
TI - Time course of brain temperature and caudate/putamen microdialysate levels of
amphetamine and dopamine in rats after multiple doses of d-amphetamine.
AB - Brain temperature monitoring and microdialysis were performed simultaneously in
the caudate/putamen (CPu) of conscious, freely moving rats dosed with d
amphetamine (AMPH). The brain temperature was determined via a thermistor
inserted through a microdialysis guide cannula located in the left CPu, while the
microdialysis probe was positioned in the right CPu. The peak AMPH and dopamine
(DA) levels were reached 40 to 60 min after dosing, while peak brain temperature
was not achieved until 20 to 40 min thereafter in rats becoming moderately
hyperthermic. Those rats becoming severely hyperthermic (temperatures above 41.0
degrees C) had microdialysate concentrations of AMPH and DA almost 2-fold higher
than those with moderate hyperthermia after the second dose of 5 mg/kg AMPH.
However, these peaks were not reached until 60 to 80 min after dosing. This was
probably due, in part, to the longer half-life of AMPH in the severely
hyperthermic group. The changes in brain temperature observed after exposure to
neurotoxic doses of AMPH closely paralleled core body temperature changes
previously reported during AMPH exposure. Temperature plays an important role in
many types of neurotoxicity, and monitoring brain temperature during
microdialysis studies can be done continuously, and with less chance of damage to
the microdialysis equipment than most of the traditional methods used to measure
core body temperature.
PMID- 10668456
TI - Neuroprotective effects of HU-211 on brain damage resulting from soman-induced
seizures.
AB - Neuroprotective effects of HU-211 (dexanabinol), a synthetic nonpsychotropic
analog of tetrahydrocannabinol, on brain damage resulting from soman-induced
seizures were examined in male Sprague-Dawley rats challenged with 1.6 LD50
soman. At 5 or 40 min after onset of seizures, the rats were given an
intraperitoneal injection of 25 mg/kg HU-211. All rats that received soman showed
electrocorticographic (ECoG) evidence of sustained seizures and status
epilepticus for 4-6 hr. HU-211 had no effect on either the strength or duration
of seizure activity. Administration of HU-211 at 5 min after seizure onset
reduced median lesion volume 86% (as assessed by microtubule-associated protein 2
(MAP2)-negative staining), and when administered 40 min post-onset, the reduction
in necrosis was 81.5% despite the presence of continuous seizures for 4-5 hr.
These observations were corroborated by hemotoxylin and eosin (H&E)
histopathological assessment that showed a significant reduction in piriform
cortical neuronal damage in HU-211-treated animals. It is concluded that HU-211
provides considerable neuroprotection against brain damage produced by soman
induced seizures.
PMID- 10668457
TI - Abuse liability assessment of neuroprotectants.
AB - There has been considerable interest in the potential of N-methyl-D-aspartate
(NMDA) receptor antagonists in the treatment of a diverse group of neurological
disorders including cerebral ischemia and neurodegeneration. The amino acids L
glutamate and L-aspartate have been shown to possibly mediate excitatory synaptic
transmission in the central nervous system (CNS) via selective excitatory amino
acid receptors. Competitive and noncompetitive antagonists acting at the NMDA
receptors have been shown to possess relevant activity. However, NMDA antagonists
can produce a variety of adverse neurobehavioral effects in both animals and
humans. These adverse events are particularly pronounced with NMDA antagonists
(phencyclidine (PCP), ketamine, and MK-801) that have dissociative anesthetic
properties and block NMDA receptor-mediated responses by binding to the cation
channel of the NMDA receptor complex. When a new pharmaceutical product
demonstrates structural similarity and/or a similar pharmacological profile with
a known drug of abuse, the characterization of its abuse potential is needed by
the FDA for scientific review. The abuse liability assessment is based upon an
evaluation of data on the chemistry, pharmacology (preclinical and clinical),
pharmacokinetics, and pharmacodynamic profiles of the drug, and the adverse
events/effects reported in clinical trials. The evaluation of the drug's abuse
potential is determined relative to pharmacologically similar drugs. This
includes determination of the drug's receptor binding efficacy, preclinical
pharmacology, reinforcing efficacy, discriminative stimulus effects, dependence
producing potential, pharmacokinetics, and assessment of the clinical efficacy
safety database relative to abuse and clinical abuse liability studies. It has
been well established that high-affinity noncompetitive NMDA antagonists have
reinforcing efficacy and can serve as discriminative stimuli in operant
procedures. In a variety of species in drug discrimination studies, each
antagonist is capable of generalizing to the others, and it is believed that
these effects may be mediated through the NMDA blockade. The generalization of
each substance for another suggests production of common subjective effects in
humans.
PMID- 10668458
TI - The future of neuroprotection.
PMID- 10668459
TI - Apoptosis: a two-edged sword in aging.
AB - Here we summarize briefly what is known about both the positive and negative
impacts of apoptosis during aging in mammalian systems and also update an earlier
review. It is important to understand both of these impacts to devise useful
interventions. Such interventions include both physiological and molecular
approaches, including transgenic interventions. The critical roles of the
mitochondria in both generating reactive oxygen species, and in initiating
apoptosis are recognized, suggesting that maintaining mitochondrial function
could be an important therapeutic goal, especially in post-mitotic tissues. In
contrast, the ability to eliminate unwanted, damaged and dysfunctional cells
through apoptosis has anti-aging implications in mitotic tissues.
PMID- 10668460
TI - Ultrastructural alterations of mitochondria in pre-apoptotic and apoptotic
hepatocytes of TNF alpha-treated galactosamine-sensitized mice.
AB - The electron microscopical studies presented here show that characteristic
morphological alterations in mitochondria are a very early hallmark of the
hepatocellular apoptotic program. Before chromatin condensation occurs, the outer
mitochondrial membrane is focally disrupted and the inner membrane protrudes
through this gap forming a hernia. The demonstration of cytochrome oxidase in
mitochondria revealed a very strong activity in pre-apoptotic and apoptotic cells
as well as in apoptotic bodies.
PMID- 10668461
TI - Mitochondrial membrane permeabilization during the apoptotic process.
AB - Apoptosis may be viewed as a triphasic process. During the pre-mitochondrial
initiation phase, very different pro-apoptotic signal transduction or damage
pathways can be activated. These pathways then converge on the mitochondrion,
where they cause the permeabilization of the inner and/or outer membranes with
consequent release of soluble intermembrane proteins into the cytosol. The
process of mitochondrial membrane permeabilization would constitute the
decision/effector phase of the apoptotic process. During the post-mitochondrial
degradation phase downstream caspases and nucleases are activated and the cell
acquires an apoptotic morphology. Recently, a number of different second
messengers (calcium, ceramide derivatives, nitric oxide, reactive oxygen species)
and pro-apoptotic proteins (Bax, Bak, Bid, and caspases) have been found to
directly compromise the barrier function of mitochondrial membranes, when added
to isolated mitochondria. The effects of several among these agents are mediated
at least in part via the permeability transition pore complex (PTPC), a composite
channel in which members of the Bcl-2 family interact with sessile transmembrane
proteins such as the adenine nucleotide translocator. These findings suggest that
the PTPC may constitute a pharmacological target for chemotherapy and
cytoprotection.
PMID- 10668462
TI - Coenzyme Q10 can in some circumstances block apoptosis, and this effect is
mediated through mitochondria.
AB - The mitochondrial component coenzyme Q10 (CoQ10) has been used for many years as
a dietary supplement intended to promote good health by trapping free radicals,
thus preventing lipid peroxidation and DNA damage. We have tested its use as a
generic anti-apoptotic compound and have found that its ability to protect
against apoptosis varies depending on both cell type and mode of cell death
induction. We have further established that this protection may be mediated by
its effect on mitochondrial function and viability. We provide additional
evidence that CoQ10's protective effect on mitochondrial membrane potential does
not always result in altered mitochondrial enzyme activity and neither does it
guarantee survival. These observations open the way for further investigations
into the mechanisms involved in mitochondrial control of apoptosis.
PMID- 10668463
TI - Neither caspase-3 nor DNA fragmentation factor is required for high molecular
weight DNA degradation in apoptosis.
AB - In this paper, we show that there is a two-step process of DNA fragmentation in
apoptosis; DNA is first cleaved to large fragments of 50-300 kb that are
subsequently cleaved to smaller oligonucleosomes in some, but not all cells.
Significantly, only the first stage is considered essential for cell death since
some cells, for example human MCF7 breast carcinoma cells and human NT2 neuronal
cells, do not show this behavior but still display normal nuclear morphological
apoptotic changes. In cells that usually produce small fragments blocking the
second (internucleosomal) stage of DNA fragmentation prevents neither nuclear
condensation nor apoptosis. We are beginning to understand why the extent of DNA
fragmentation during apoptosis varies enormously and why it appears to be a
function of the cell type not the inducer. Presumably, this reflects the content
of not only endonuclease activit(ies) but also on the ability of the cells to
activate caspases, particularly caspase-3, and other proteases that may be
involved in endonuclease activation. Since NT2 cells activate caspase-3, but do
not correctly process DFF45, other factors must also impinge on the inevitability
of that process.
PMID- 10668464
TI - Apoptosis-related functional features of the DNaseI-like family of nucleases.
AB - Rat DNaseYb and its human homolog DHP2 are members of a new family of DNaseI-like
endonucleases. They contain all the conserved amino acid residues to engage a
DNaseI-like catalytic activity and the same molecular mechanisms of DNA
hydrolysis. The sequence similarity can be extended to other families of
nucleases, such as FEN-1, DNA polymerases, RNaseH and exonuclease III, involved
in the ion-dependent hydrolysis of nucleic acids. Their unique features include
the NLS signals that place them in the nuclei and a high content of positively
charged amino acid residues that results in their high affinity for the
substrate. Their properties are consistent with a role in the early stage DNA
degradation during apoptosis. The caspase-DFF45/CIDE-CPAN pathway is most likely
involved in the second stage of internucleosomal DNA degradation. However, cells
express constitutively multiple transcripts encoding DNA degrading enzymes and
related molecules, hence they have the molecular diversity to engage the self
destructive pathway appropriate to a given trigger.
PMID- 10668465
TI - Does the oxidative/glycolytic ratio determine proliferation or death in immune
recognition?
AB - Here we discuss the possibility that the way cells utilize fuel(s) for energy
confers the properties that can be recognized by the immune system and,
reciprocally, that recognition by the immune system can alter the balance of the
cell's energy metabolism. We propose that immune recognition, of somatic cells
via MHC can alter the their energy metabolism and induce a metabolic shift. We
demonstrate the reciprocal relationship that inducing a shift in metabolism
toward glycolysis by supplying glucose and insulin results in the upregulation of
immunologically recognizable molecules such as cell surface Fas. Thus, immune
recognition can induce metabolic deviation. Metabolic deviation can result in
altered immune recognition and ultimately in cell proliferation, cell
differentiation, or cell death.
PMID- 10668466
TI - Regulation of transglutaminases by nitric oxide.
AB - Nitric oxide (NO) is an inorganic diffusible molecular messenger that plays
several central roles in pathophysiology. NO can affect the biological activity
of proteins through the direct or indirect (via intermediate S-nitrosothiols) S
nitrosylation of protein thiol groups. Transglutaminases (TGases), Ca(++)
dependent enzymes that modify proteins by cross-linking reactions, require a
cysteine residue in the active site as a prerequisite for their catalytic
activity. Therefore, NO may regulate enzymatic activity of TGases and their
biological effects, via S-nitrosylation of their crucial thiol groups. We here
review the effects of NO on coagulation factor XIII (fXIII, or plasma TGase) and
TGase 2 (or tissue transglutaminase). NO has an inhibitory effect on fXIII, thus
suppressing the gamma-chain cross-linking in fibrin gels, and subsequent clot
formation. Tissue transglutaminase, an apoptotic effector molecule, also
represents a molecular target for NO. Accordingly, the inhibition of tissue
transglutaminase enzymatic activity by NO is able to prevent the induction of
apoptosis.
PMID- 10668467
TI - The molecular mechanism of programmed cell death in C. elegans.
AB - Programmed cell death or apoptosis plays a fundamental role during animal
development, metamorphosis, and tissue homeostasis. It is a genetically
controlled physiological process that comprises two distinct and sequential
processes: the death of cells, and their subsequent removal by engulfing cells.
In the nematode C. elegans, genetic studies led to the discovery of 15 genes that
function in programmed cell death (FIG. 1). These 15 genes have been divided into
four groups based on the order of their activity during the process of programmed
cell death: (1) those involved in the decision making (ces-1 and ces-2); (2) in
the process of execution (ced-3, ced-4, ced-9 and egl-1); (3) in the engulfment
of dying cells by engulfing cells (ced-1, ced-2, ced-5, ced-6, ced-7, ced-10, ced
12); and (4) those in the degradation of cell corpses within engulfing cells (nuc
1). In the last five years, several genes in the genetic pathway of programmed
cell death have been shown to be conserved across a wide range of species; all
genes involved in the step of execution in C. elegans have their corresponding
mammalian homologs (FIG. 2). Furthermore, emerging evidence from molecular
studies of engulfment genes in several species suggests that the signaling
process from apoptotic cells to engulfing cells and the subsequent engulfment
process might be also conserved across species (TABLE 1).
PMID- 10668468
TI - Developmental regulation of induced and programmed cell death in Xenopus embryos.
AB - We have analyzed the role of cell death during early Xenopus development and have
identified two distinct types of cell death programs during the period between
fertilization and the tadpole stage. One is a maternal cell death program that is
activated at the onset of gastrulation following damage to the pre-midblastula
transition embryo, resulting in the death of non-viable cells. The activation of
this cell death program at a specific time during development is a maternally
programmed event under the control of a developmental timer set at fertilization,
and does not depend on the type of stress applied, on cell cycle progression, or
de novo protein synthesis. Subsequently, a second program corresponding to
programmed cell death is initiated as part of the normal development of the
embryo. Programmed cell death starts at the onset of gastrulation and we have
analyzed its spatio-temporal patterns by a whole-mount in situ DNA end labeling
technique (the TUNEL protocol).
PMID- 10668469
TI - Bone morphogenetic proteins regulate interdigital cell death in the avian embryo.
AB - The embryonic limb bud provides an excellent model for analyzing the mechanisms
that regulate programmed cell death during development. At the time of digit
formation in the developing autopod, the undifferentiated distal mesodermal cells
may undergo or chondrogenic differentiation or apoptosis depending whether they
are incorporated into the future digital rays or into the interdigital spaces.
Both chondrogenesis or apoptosis are induced by local BMPS. However, whereas the
chondrogenic-promoting activity of BMPs appears to be regulated through the BMPR
1b receptor, the mechanism by which the BMPs execute the death program remains
unknown. The BMP proapoptotic activity requires the expression of members of the
msx family of closely related homeobox-containing genes and is finally mediated
by caspase activation, but the nature of the caspase(s) directly responsible for
the cell death is also unknown. Finally, other growth factors present in the
developing autopod at the stages of digit formation such as members of the FGF
and TGF beta families modulate the ability of BMPs to induce cell death or
chondrogenesis.
PMID- 10668470
TI - Oxidative damage, bleomycin, and gamma radiation induce different types of DNA
strand breaks in normal lymphocytes and thymocytes. A comet assay study.
AB - Most anticancer treatments such as chemo- and radiotherapy induce DNA damage and
apoptosis in normal cells. The aim of this study was to assess the induction of
single and double DNA strand breaks (ssb and dsb, respectively) and apoptosis in
normal human lymphocytes and rat thymocytes subjected to the action of H2O2,
bleomycin and ionizing radiation. Normal human peripheral thymocytes and young
rat thymocytes were subjected to the following treatments: a) H2O2; b) bleomycin,
and c) gamma-radiation, all with various doses. DNA strand breaks were studied
with the alkaline and neutral comet assay for detection of ssb and dsb. Apoptosis
was quantified morphologically and with DNA agarose gel electrophoresis. After
H2O2 treatment, a dose-dependent increase of ssb was observed. Bleomycin
treatment produced a moderate increase of ssb at lower concentrations and a
striking increase of dsb at higher concentrations that coincided with the
presence of apoptosis and DNA ladders. Gamma radiation initially induced the
formation of ssb, and after three hours an increase of dsb in a dose-dependent
manner. Apoptosis and DNA laddering appeared only 3 hours post-irradiation. The
biomonitoring of DNA damage inflicted by antineoplastic agents can be easily
performed with the comet assay and could be useful to monitor and modulate chemo-
and radiotherapeutic regimes in cancer patients.
PMID- 10668471
TI - Tumor cells utilize multiple pathways to down-modulate apoptosis. Lessons from a
mouse model of islet cell carcinogenesis.
AB - Apoptosis, the process of programmed cell death, plays a critical role in many
normal and pathological (disease) processes. In normal tissues, apoptosis
functions in the homeostatic maintenance of proper tissue and organ size by
eliminating aged cells to offset the birth of new cells that arise by mitosis. In
disease, apoptosis can affect the pathological process is two disparate ways.
There are diseases that have too much apoptosis such as autoimmune diabetes and
Alzheimer's, or those that have too little apoptosis, such as cancer. This review
will focus on the latter and, more specifically, detail and summarize some
important lessons learned about apoptosis and cancer from studying a transgenic
mouse model of islet cell carcinoma, RIP-Tag, as outlined below.
PMID- 10668472
TI - Hyperoxia in cell culture. A non-apoptotic programmed cell death.
AB - Here we discuss the morphological features and our current understanding of the
pathways involved in non-apoptotic cell death from O2 toxicity. Preliminary data
on hyperoxic signaling indicate that NF-kappa B translocation (and presumptive
activation) is not a result of the p42/p44 MAPK pathway, but a likely downstream
consequence of activation of the JNK pathway. Our observations suggest the
existence of multiple signal transduction pathways in hyperoxia-induced cell
death: one involved in the stress response which appears to be NF-kappa B
dependent and another in cell death.
PMID- 10668473
TI - Hyperoxia-induced cell death in the lung--the correlation of apoptosis, necrosis,
and inflammation.
AB - Prolonged exposure to hyperoxia causes tissue damage in many organs and tissues.
Since the entire surface area of lung epithelium is directly exposed to O2 and
other inhaled agents, hyperoxia leads to the development of both acute and
chronic lung injuries. These pathologic changes in the lung can also be seen in
acute lung injury (ALI) in response to other agents. Simple strategies to
mitigate hyperoxia-induced ALI might not be effective by virtue of merely
reducing or augmenting the extent of apoptosis of pulmonary cells. Identification
of the specific cell types undergoing apoptosis and further understanding of the
precise timing of the onset of apoptosis may be necessary in order to gain a
greater understanding of the connection between apoptosis and tolerance to
hyperoxia and ALI. Attention should also be focused on other forms of non
apoptotic programmed cell death.
PMID- 10668474
TI - Apoptosis in coxsackievirus B3-induced myocarditis and dilated cardiomyopathy.
AB - Group B coxsackieviruses (CVB), which infect the myocardium, cause myocarditis
and dilated cardiomyopathy. However, not all infections of the myocardium result
in disease. In the mouse model, CVB infection stimulates autoimmune T cell
response to cardiac antigens, and these autoimmune effectors cause myocyte
necrosis and cardiomyopathy. Induction of pathogenic autoimmunity depends upon
CD4+ Th1 (interferon-gamma positive) cells while Th2 (IL-4 positive) cell
responses promote disease resistance. T lymphocytes expressing the gamma-delta T
cell receptor (gamma delta +) constitute up to 12% of the inflammatory cells in
the heart and are crucial to maintaining a dominant Th1 response phenotype. gamma
delta + lymphocytes modulate T cell responses by selectively lysing CD4+ Th2
cells. Th1 cells are not killed by gamma delta + cells. Lysis requires direct
cell:cell interaction between the gamma delta + cell and CD4+ Th2 target and is
most likely mediated through Fas:FasL interaction. These studies demonstrate a
novel mechanism for immune modulation of cytokine responses in vivo.
PMID- 10668475
TI - The immune response to apoptotic cells.
AB - Programmed cell death (PCD) can be divided into two distinct but linked
sequential processes, killing of the cells and removal of the dead cells, which
may be a neighboring cell or a professional phagocyte. Following internalization
of the apoptotic cell, the phagocyte typically triggers neither the development
of a pro-inflammatory response nor the production of autoantibodies directed
against apoptotic self antigens. Since apoptotic cells are characterized by
translocation of autoantigens such as nucleosomes to the surface of the cell, we
tested the hypothesis that excess or abnormally processed apoptotic cells can
generate autoantibodies. We have found that syngeneic apoptotic load can induce
transient hypergammaglobulinemia, anti-DNA, anticardiolipin, and glomerular
depositions in normal mice. Furthermore, we also found that one of the important
mechanisms of uptake of apoptotic cells involves opsonization by the complement
system, suggesting that deficient states could lead to aberrant handling of
apoptotic cells. Therefore, conditions in which apoptotic cells become
immunogenic may explain antigen selection in inflammatory and autoimmune
conditions, such as in systemic lupus erythematosus (SLE).
PMID- 10668476
TI - Programmed cell death as a mechanism of CD4 and CD8 T cell deletion in AIDS.
Molecular control and effect of highly active anti-retroviral therapy.
AB - Infection with human immunodeficiency virus (HIV) results in the progressive
destruction of CD4 T lymphocytes, generally associated with progression of the
disease. The progressive disappearance of CD4 T lymphocytes leads to the lack of
control of HIV replication and to the development of severe immune deficiency
responsible for the occurrence of opportunistic infections associated with AIDS.
In this review we discuss premature lymphocyte apoptosis in the context of HIV
infection as the consequence of the continuous production of viral proteins,
leading to an unbalanced immune activation and to the triggering of apoptotic
programs. The chronic immune activation induces the continuous expression of
death factors which could turn lymphocytes, including CD4 T cells, CD8 CTL or
APC, into effectors of apoptosis, leading to the destruction of healthy activated
non-infected cells. Thus, programmed cell death would significantly contribute to
peripheral T cell depletion in AIDS, particularly if the Th cell renewal is
impaired. Under potent anti-retroviral therapies, a complete normalization of
lymphocyte apoptosis is observed, concomitant with a partial restoration of the
number and the functions of the immune system.
PMID- 10668477
TI - Progress in cancer chemoprevention.
AB - More than 40 promising agents and agent combinations are being evaluated
clinically as chemopreventive drugs for major cancer targets. A few have been in
vanguard, large-scale intervention trials--for example, the studies of tamoxifen
and fenretinide in breast, 13-cis-retinoic acid in head and neck, vitamin E and
selenium in prostate, and calcium in colon. These and other agents are currently
in phase II chemoprevention trials to establish the scope of their
chemopreventive efficacy and to develop intermediate biomarkers as surrogate end
points for cancer incidence in future studies. In this group are fenretinide, 2
difluoromethylornithine, and oltipraz. Nonsteroidal anti-inflammatories (NSAID)
are also in this group because of their colon cancer chemopreventive effects in
clinical intervention, epidemiological, and animal studies. New agents are
continually considered for development as chemopreventive drugs. Preventive
strategies with antiandrogens are evolving for prostate cancer. Anti
inflammatories that selectively inhibit inducible cyclooxygenase (COX)-2 are
being investigated in colon as alternatives to the NSAID, which inhibit both COX
1 and COX-2 and derive their toxicity from COX-1 inhibition. Newer retinoids with
reduced toxicity, increased efficacy, or both (e.g., 9-cis-retinoic acid) are
being investigated. Promising chemopreventive drugs are also being developed from
dietary substances (e.g., green and black tea polyphenols, soy isoflavones,
curcumin, phenethyl isothiocyanate, sulforaphane, lycopene, indole-3-carbinol,
perillyl alcohol). Basic and translational research necessary to progress in
chemopreventive agent development includes, for example, (1) molecular and
genomic biomarkers that can be used for risk assessment and as surrogate end
points in clinical studies, (2) animal carcinogenesis models that mimic human
disease (including transgenic and gene knockout mice), and (3) novel agent
treatment regimens (e.g., local delivery to cancer targets, agent combinations,
and pharmacodynamically guided dosing).
PMID- 10668478
TI - Preclinical mouse models for cancer chemoprevention studies.
AB - To aid in identifying the ability of chemopreventive agents to inhibit tumor
development, new preclinical in vivo rodent models have recently been developed.
Some of the models contain targeted mutations capable of increasing the incidence
and progression of neoplastic lesions, whereas in other models dietary nutrients
induce preneoplastic lesions in normal mice. These new preclinical models are
assisting the analysis of genetic and environmental factors leading to neoplasia,
and clinical studies to evaluate the chemopreventive efficacy of specific
nutrients and pharmacological agents.
PMID- 10668479
TI - Cellular mechanisms of risk and transformation.
AB - Our early work using the first array and imaging methods for the quantitative
analysis of the expression of 4000 cDNA sequences suggested that modulation of
mitochondrial gene expression was a factor in determining whether colonic
epithelial cells displayed a differentiated or transformed phenotype. We have
since dissected a pathway in which mitochondrial function is a key element in
determining the probability of cells undergoing cell-cycle arrest, lineage
specific differentiation, and cell death. Moreover, this pathway is linked to
signaling through beta-catenin-Tcf, but in a manner that is independent of
effects of the APC gene on beta-catenin-Tcf activity. Utilization of unique mouse
genetic models of intestinal tumorigenesis has confirmed that mitochondrial
function is an important element in generation of apoptotic cells in the colon in
vivo and has demonstrated that modulation of cell death may be involved in
intestinal tumor progression rather than initiation. Normal spatial and temporal
patterns of cell proliferation, differentiation, and apoptosis in the colonic
mucosa are determined by developmentally programmed genetic signals and external
signals generated by homo- and heterotypic cell interactions, humoral agents, and
lumenal contents. Mitochondrial function may play a pivotal role in integrating
these signals and in determining probability of cells entering different
maturation pathways. How this is accomplished is under investigation using high
density cDNA microarrays.
PMID- 10668480
TI - APC and intestinal carcinogenesis. Insights from animal models.
AB - The APC protein is a crucial regulator of intestinal cell growth, and mutations
in the APC gene are a common initial event in the process of human colorectal
carcinogenesis. Animals bearing germline mutations in Apc are therefore important
models for human colorectal cancer. These animals have been used both to
understand the biology of human colorectal cancer and to screen for agents able
to prevent malignant transformation of susceptible intestinal cells.
PMID- 10668481
TI - Oncogenic activating mutations in the neu/erbB-2 oncogene are involved in the
induction of mammary tumors.
AB - Amplification and overexpression of erbB-2/neu is an important determinant in the
initiation and progression of human breast cancer. Indeed, transgenic mice that
over-express the neu proto-oncogene heritably develop mammary adenocarcinomas.
Tumorigenesis in these transgenic strains is associated with activation of the
intrinsic catalytic activity of Neu. In many of these tumors, activation of Neu
occurs as a result of somatic mutations located within the transgene itself.
Examination of the altered neu transcripts revealed the presence of in-frame
deletions that encode aberrant Neu receptors lacking 5 to 12 amino acids within
the extracellular domain proximal to the transmembrane region of Neu. In addition
to these deletion mutants we have also detected single point mutations within
this juxta-transmembrane region. The majority of the mutations analyzed affect
the one of several conserved cysteine residues present within this region.
Introduction of these activating mutations into the wild-type neu cDNA results in
its oncogenic conversion. Taken together, these observations suggest that this
cysteine-rich region plays an important role in regulating the catalytic activity
of Neu.
PMID- 10668482
TI - Cyclooxygenase-deficient mice. A summary of their characteristics and
susceptibilities to inflammation and carcinogenesis.
AB - Cyclooxygenase (COX)-1- and COX-2-deficient mice have unique physiological
differences that have allowed investigation into the individual biological roles
of the COX isoforms. In the following, the phenotypes of the two COX knockout
mice are summarized, and recent studies to investigate the effects of COX
deficiency on inflammatory responses and cancer susceptibility are discussed. The
data suggest that both isoforms have important roles in the maintenance of
physiological homeostasis and that such designations as house-keeping and/or
response gene may not be entirely accurate. Furthermore, data from COX-deficient
mice indicate that both isoforms can contribute to the inflammatory response and
that both isoforms have significant roles in carcinogenesis.
PMID- 10668483
TI - Inhibition of cyclooxygenase-2 expression. An approach to preventing head and
neck cancer.
AB - Cyclooxygenase (COX) catalyzes the formation of prostaglandins (PG) from
arachidonic acid. A large body of evidence has accumulated to suggest that COX-2,
the inducible form of COX, is important in carcinogenesis. In this study, we
determined whether (1) COX-2 was overexpressed in squamous cell carcinoma of the
head and neck (HNSCC) and whether (2) retinoids, a class of chemopreventive
agents, blocked epidermal growth factor (EGF)-mediated activation of COX-2
expression. Levels of COX-2 mRNA were determined in 15 cases of HNSCC and 10
cases of normal oral mucosa. Nearly a 100-fold increase in amounts of COX-2 mRNA
was detected in HNSCC. By immunoblot analysis, COX-2 protein was detected in 6 of
6 cases of HNSCC but was undetectable in normal mucosa. Because retinoids protect
against oral cavity cancer, we investigated whether retinoids could suppress EGF
mediated induction of COX-2 in cultured oral squamous carcinoma cells. Treatment
with EGF led to increased levels of COX-2 mRNA, COX-2 protein, and synthesis of
PG. These effects were suppressed by a variety of retinoids. Based on the results
of this study, it will be important to establish whether newly developed
selective COX-2 inhibitors are useful in preventing or treating HNSCC. Moreover,
the anticancer properties of retinoids may be due, in part, to inhibition of COX
2 expression. Combining a retinoid with a selective COX-2 inhibitor may be more
effective than either agent alone in preventing cancer of the upper aerodigestive
tract.
PMID- 10668484
TI - The role of COX-2 in intestinal cancer.
AB - Cyclooxygenase (COX), the key regulatory enzyme for prostaglandin synthesis is
transcribed from two distinct genes. COX-1 is expressed constitutively in most
tissues, and COX-2 is induced by a wide variety of stimuli and was initially
identified as an immediate-early growth response gene. In addition, COX-2
expression is markedly increased in 85-90% of human colorectal adenocarcinomas,
whereas COX-1 levels remain unchanged. Several epidemiological studies have
reported a 40-50% reduction in the risk of developing colorectal cancer in
persons who chronically take such nonsteroidal anti-inflammatory drugs (NSAIDs)
as aspirin, which are classic inhibitors of cyclooxygenase. Genetic evidence also
supports a role for COX-2, since mice null for COX-2 have an 86% reduction in
tumor multiplicity in a background containing a mutated APC allele. These results
strongly suggest that COX-2 contributes to the development of intestinal tumors
and that inhibition of COX is chemo-preventative.
PMID- 10668485
TI - COX-2 inhibitors. A new class of antiangiogenic agents.
AB - The formation of new blood vessels by angiogenesis to provide adequate blood
supply is a key requirement for the growth of many tumors. While normal blood
vessels expressed the COX-1 enzyme, new angiogenic endothelial cells expressed
the inducible COX-2. We evaluated the role of COX inhibitors in the mouse corneal
micropocket assay in which angiogenesis is driven by the addition of a Hydron
pellet containing basic fibroblast growth factor (bFGF). Neovascular areas were
measured with a slit lamp five days after pellet implantation into the corneal
stroma. All animals containing implants with bFGF (90 ng) developed intensive
areas of neovascularization, whereas the controls implanted with the Hydron
pellet alone did not. Indomethacin (a nonselective COX-1/COX-2 inhibitor) and SC
236 (a COX-2-selective inhibitor) inhibited angiogenesis in a dose-dependent
manner. Importantly, the indomethacin-treated mice developed severe
gastrointestinal toxicity at the efficacious dose of 3 mg/kg/day. By contrast,
gastrointestinal lesions were not observed, and platelet COX-1 activity was
unaffected, at anti-angiogenic doses of SC-236 (1-6 mg/kg/day). Furthermore, a
COX-1-selective inhibitor, SC-560, was ineffective at doses up to 10 mg/kg, a
dose that completely blocked platelet COX-1 activity in these mice. SC-236 was
also effective in reducing angiogenesis driven by bFGF, vascular endothelium
growth factor (VEGF), or carrageenan in the matrigel rat model. Finally, in
several tumor models, SC-236 consistently and effectively inhibited tumor growth
and angiogenesis. This novel antiangiogenic activity of COX-2 inhibitors
indicates their potential therapeutic utility in several types of cancer.
PMID- 10668486
TI - Micronutrient deficiencies. A major cause of DNA damage.
AB - Deficiencies of the vitamins B12, B6, C, E, folate, or niacin, or of iron or zinc
mimic radiation in damaging DNA by causing single- and double-strand breaks,
oxidative lesions, or both. The percentage of the population of the United States
that has a low intake (< 50% of the RDA) for each of these eight micronutrients
ranges from 2% to 20+ percent. A level of folate deficiency causing chromosome
breaks occurred in approximately 10% of the population of the United States, and
in a much higher percentage of the poor. Folate deficiency causes extensive
incorporation of uracil into human DNA (4 million/cell), leading to chromosomal
breaks. This mechanism is the likely cause of the increased colon cancer risk
associated with low folate intake. Some evidence, and mechanistic considerations,
suggest that vitamin B12 and B6 deficiencies also cause high uracil and
chromosome breaks. Micronutrient deficiency may explain, in good part, why the
quarter of the population that eats the fewest fruits and vegetables (five
portions a day is advised) has about double the cancer rate for most types of
cancer when compared to the quarter with the highest intake. Eighty percent of
American children and adolescents and 68% of adults do not eat five portions a
day. Common micronutrient deficiencies are likely to damage DNA by the same
mechanism as radiation and many chemicals, appear to be orders of magnitude more
important, and should be compared for perspective. Remedying micronutrient
deficiencies is likely to lead to a major improvement in health and an increase
in longevity at low cost.
PMID- 10668487
TI - Calcium and vitamin D. Their potential roles in colon and breast cancer
prevention.
AB - The geographic distribution of colon cancer is similar to the historical
geographic distribution of rickets. The highest death rates from colon cancer
occur in areas that had high prevalence rates of rickets--regions with winter
ultraviolet radiation deficiency, generally due to a combination of high or
moderately high latitude, high-sulfur content air pollution (acid haze), higher
than average stratospheric ozone thickness, and persistently thick winter cloud
cover. The geographic distribution of colon cancer mortality rates reveals
significantly low death rates at low latitudes in the United States and
significantly high rates in the industrialized Northeast. The Northeast has a
combination of latitude, climate, and air pollution that prevents any synthesis
of vitamin D during a five-month vitamin D winter. Breast cancer death rates in
white women also rise with distance from the equator and are highest in areas
with long vitamin D winters. Colon cancer incidence rates also have been shown to
be inversely proportional to intake of calcium. These findings, which are
consistent with laboratory results, indicate that most cases of colon cancer may
be prevented with regular intake of calcium in the range of 1,800 mg per day, in
a dietary context that includes 800 IU per day (20 micrograms) of vitamin D3. (In
women, an intake of approximately 1,000 mg of calcium per 1,000 kcal of energy
with 800 IU of vitamin D would be sufficient.) In observational studies, the
source of approximately 90% of the calcium intake was vitamin D-fortified milk.
Vitamin D may also be obtained from fatty fish. In addition to reduction of
incidence and mortality rates from colon cancer, epidemiological data suggest
that intake of 800 IU/day of vitamin D may be associated with enhanced survival
rates among breast cancer cases.
PMID- 10668488
TI - Preclinical and early human studies of calcium and colon cancer prevention.
AB - Colorectal cancer continues to be a major cause of tumor mortality in the United
States and other countries; despite attempts to improve the screening of high
risk populations, the incidence of this disease is still very high. Therefore,
chemoprevention continues to be an important goal for the primary prevention of
colorectal cancer. Among recent chemopreventive approaches, the administration of
calcium and vitamin D continue to be evaluated in both preclinical and clinical
studies. Many experimental findings described below have indicated associations
between high calcium and vitamin D intake and decreased risk for colorectal
cancer.
PMID- 10668489
TI - Studies of calcium in food supplements in humans.
AB - Colon cancer is one of the commonest cancers in the Western world. Environmental
factors appear to predominate as exemplified by a change in incidence in colon
cancer within 20 years when people emigrate from a low- to a high-incidence
country. It had been suggested that a diet high in energy, fat, and meat content
and low in fiber content is most likely responsible. Epidemiologic observations
have pointed to a potential effect of calcium or/and vitamin D in reducing the
incidence of colon cancer. Other studies have shown a reduction in preneoplastic
colon adenomas with increased calcium or/and vitamin D intake. High fat diets
were shown to be accompanied by an increase in fecal fatty acids and bile acids
or a change in bile acid composition. Soluble fatty acids and bile acids then
could interact with the colonic epithelium inducing cell damage and increased
proliferation. A hypothesis was developed suggesting that calcium supplementation
and increased calcium in the colonic lumen would precipitate these bile acids and
fatty acids. Examination of the effect of supplemental calcium or calcium in
dairy foods showed a major reduction in fecal bile acids and fatty acids in
solution in volunteers and accompanied by a reduction in cytolytic activity.
Studies then were performed in patients at risk for colon cancer seeking a change
in proliferative biomarkers of risk from a high-risk to a low-risk pattern with
supplemental calcium administration. These studies generally have shown a
beneficial effect of the addition of calcium at 1.2-2 gm per day in addition to a
regular diet for periods of 2 to 6 months. A recently published study also
demonstrated that a diet, in which low-fat dairy foods containing an average of
about 825 mg of calcium, significantly improved proliferative biomarkers as well
as two differentiation bio-markers of risk for colon cancer from a high- to a low
risk pattern. These observations, together with recent studies showing reduced
adenomatous polyp recurrence when supplemental calcium was provided, demonstrate
the potential of calcium and perhaps vitamin D as chemopreventive agents for
colorectal neoplasia.
PMID- 10668490
TI - Calcium supplements and colorectal adenomas. Polyp Prevention Study Group.
AB - Experimental and observational findings suggest that calcium intake may protect
against colorectal neoplasia. To investigate this hypothesis, we conducted a
randomized, double-blind trial of colorectal adenoma recurrence. Nine hundred
thirty patients with a recent history of colorectal adenomas were randomly given
calcium carbonate (3 gm daily; 1200 mg elemental calcium) or placebo, with follow
up colonoscopies one and four years after the qualifying examination. The main
analysis focused on new adenomas found after the first follow-up endoscopy, up to
(and including) the second follow-up examination. Risk ratios of at least one
recurrent adenoma and ratios of the average numbers of adenomas were calculated
as measures of calcium effect. There was a lower risk of recurrent adenomas in
subjects assigned calcium. Eight hundred thirty-two patients had two follow-up
examinations and were included in the main analysis; the adjusted risk ratio of
one or more adenomas was 0.81 (95% CI 0.67 to 0.99); the adjusted ratio of the
average numbers of adenomas was 0.76 (95% CI 0.60 to 0.96). Among subjects who
had at least one follow-up colonoscopy, the adjusted risk ratio of one or more
recurrent adenomas was 0.85 (95% CI 0.74 to 0.98). The effect of calcium seemed
independent of initial dietary fat and calcium intake. No toxicity was associated
with supplementation. These findings indicate that calcium supplementation has a
modest protective effect against colorectal adenomas, precursors of most
colorectal cancers.
PMID- 10668491
TI - Breast cancer prevention by antiestrogens.
AB - A new era has been entered with the first demonstration that an antiestrogen can
prevent breast cancer. In a landmark study tamoxifen was shown to reduce the
incidence of breast cancer by approximately 50%. The reduction was observed in
pre- and postmenopausal women at increased risk of breast cancer. Invasive
cancers were reduced, the reduction being in the estrogen receptor-positive
cancers. No preventive effect was observed for estrogen receptor-negative tumors.
In situ cancers were also significantly reduced. A collateral benefit was a
significant reduction in fractures due to osteoporosis. Adverse effects included
a very small increase in the incidence of endometrial cancer, cataracts, and
stroke. The benefits appear to outweigh the risks for those at high risk.
Preliminary studies of a new selective estrogen receptor modulator (SERM 2),
raloxifene, developed for the prevention of osteoporosis, have shown that the
breast cancer rate was reduced by more than 50% without any concomitant increase
in endometrial cancer. The search for a SERM 3, and beyond, may lead to the
development of drugs that have the beneficial effects of estrogen while
preventing breast cancer and osteoporosis.
PMID- 10668492
TI - European trials on dietary supplementation for cancer prevention.
AB - European institutions aimed at cancer research and control are spending sizable
resources to develop preclinical and clinical chemoprevention trials. Pilot
studies showed positive effect on colorectal cell proliferation from
supplementation with calcium; vitamins A, C, and E; omega-3 fatty acids; and
folic acid. A significant reduction in adenoma recurrence after polypectomy was
found in patients randomly assigned to take vitamin A, C, and E supplementation
or, to a lesser extent, lactulose. Although first reports showed a disquieting
higher incidence of lung cancer in male smokers who took beta-carotene
supplementation, the European Organization of Research and Treatment of Cancer
(EORTC) planned a chemoprevention study on the prevention of second primary
tumors in patients with curatively treated head and neck or lung cancer
(EUROSCAN). Retinol palmitate or N-acetylcysteine or both are given for two
years. The European Cancer Prevention Organization (ECP) is carrying out a
clinical trial in patients with previous adenomas of the large bowel, to test the
efficacy of calcium or fiber supplementation on adenoma recurrence. ECP in
collaboration with EURONUT has also started a multinational intervention study of
the effect of H. pylori eradication and/or dietary supplementation with vitamin C
on intestinal metaplasia.
PMID- 10668493
TI - Update from Asia. Asian studies on cancer chemoprevention.
AB - In Asia, nontoxic dietary products are considered desirable primary prevention
vehicles for conquering cancer. As early as 1978, investigators in Korea carried
out extensive long-term anticarcinogenicity experiments using the mouse lung
tumor model and observed an anticarcinogenic effect of Panax ginseng C.A. Meyer
extract in 1980. The results showed that natural products can provide hope for
human cancer prevention. A newly established nine-week medium-term model using
mouse lung tumors (Yun's model) could confirm the anticarcinogenicity of ginseng
that varies according to its type and age. Subsequently, the ginseng was shown by
epidemiological studies to be a nonorgan-specific cancer preventive agent
associated with a dose-response relationship. The anticarcinogenic effects of
vegetarian foods common at every dining table in Korea and some synthetics were
also studied using Yun's nine-week model. In brief, ascorbic acid, soybean
lecithin, capsaicin, biochanin A, Ganoderma lucidum, caffeine, and a novel
synthetic 2-(allylthio)pyrazine decrease the incidence of mouse lung tumors,
whereas fresh ginseng (4 years old), carrot, spinach, Sesamum indicum, beta
carotene, and 13-cis retinoic acid do not. This result regarding beta-carotene is
consistent with the ineffective findings of the ATBC trial, the CARET trial, and
the Physicians' Health Study. In 1983, a cancer chemoprevention study group was
first established in Japan. Subsequently, (-)-epigallocatechin gallate,
cryptoporic acid E, and sarcophytol A from natural products, and synthetic
acyclic retinoid and canventol were shown to be anticarcinogenic or
chemopreventive in human subjects. Despite the frequent consumption of tea
wordwide as a beverage and current experimental evidence of anticarcinogenesis,
including controversial results of epidemiological studies, more systematic
clinical trials for confirmation of preventive activity of tea against cancer are
needed. Placebo-controlled intervention trials of dietary fiber are under study
in Japan. In the past decade, new triterpenoids were isolated from various
natural sources, and its biological activities were investigated in Asia. In the
late 1970s a comprehensive chemoprevention program was established at the
Institute of Materia Medica, Chinese Academy of Medical Sciences. Since then,
many retinoid compounds have been synthesized and screened in the search for
chemopreventive cancer agents. The National Cancer Institute (USA) and China are
jointly engaged in the two-nutrition intervention in Linxian, China. The results
of joint study of the general population and of dysplasia in China should
stimulate further research to clarify the potential benefits of micronutrient
supplements. We need to clarify if there is a connection between the lower rates
of cancer mortality in Korea and the frequent consumption of anticarcinogenic
vegetables or traditional foods, including ginseng and Ganoderma lucidum. The
constituents of the nontoxic stable dietary products promise to be the future
hope for conquering cancers in the coming years.
PMID- 10668494
TI - Squalene, olive oil, and cancer risk. Review and hypothesis.
AB - Epidemiologic studies of breast and pancreatic cancer in several Mediterranean
populations have demonstrated that increased dietary intake of olive oil is
associated with a small decreased risk, or no increased risk, of cancer, despite
a high overall lipid intake. Experimental animal models in high dietary fat and
cancer also indicate that olive oil either has no effect, or a protective effect,
on the prevention of a variety of chemically induced tumors. As a working
hypothesis, it is proposed that the high squalene content of olive oil, as
compared to other human foods, is a major factor in the cancer-risk reducing
effect of olive oil. Experiments in animal models suggest a tumor-inhibiting role
for squalene. A mechanism is proposed for the tumor-inhibitory activity of
squalene based on its known strong inhibitory activity of HMG-COA reductase
catalytic activity in vivo, thus reducing farnesyl pyrophosphate (FPP)
availability for "prenylation" of ras oncogene, which relocates this oncogene to
cell membranes and is required for the signal-transducing function of ras.
Reduction of mutated ras oncogene activation may be useful in breast and colon
cancer and may be particularly applicable to pancreatic cancers that are strongly
associated with ras oncogenes.
PMID- 10668495
TI - Multifunctional aspects of the action of indole-3-carbinol as an antitumor agent.
AB - Previous studies from this laboratory have suggested that 2-hydroxyestrone is
protective against breast cancer, whereas the other principal metabolite, 16
alpha-hydroxyestrone, and the lesser metabolite quantitatively, 4-hydroxyestrone,
are potent carcinogens. Attempts to directly decrease the formation of the 16
hydroxylated metabolite were either unsuccessful or required such high levels of
the therapeutic agent as to be impractical. On the other hand the concentration
of the protective metabolite, 2-hydroxyestrone, proved to be readily modulated by
a variety of agents, both in the direction of increased protection and the
opposite direction, increased risk by a variety of agents and activities. We have
focussed our attention on indole-3-carbinol, a compound found in cruciferous
vegetables, and its further metabolites in the body, diindolylmethane (DIM) and
indolylcarbazole (ICZ), because of its relative safety and multifaceted
activities. It has been shown that it induces CyP4501A1, increasing 2
hydroxylation of estrogens, leading to the protective 2-OHE1, and also decreases
CyP1B1 sharply, inhibiting 4-hydroxylation of estradiol, thereby decreasing the
formation of the carcinogenic 4-OHE1. In addition to these indirect effects as a
result of altered estrogen metabolism, indole-3-carbinol has been shown to have
direct effects on apoptosis and cyclin D, resulting in blockage of the cell
cycle. In addition to its antitumor activity in animals, it has also been shown
to be effective against HPV-mediated tumors in human patients. All of these
responses make the study of its behavior as a therapeutic agent of considerable
interest.
PMID- 10668496
TI - Resveratrol inhibits cyclooxygenase-2 transcription in human mammary epithelial
cells.
AB - A large body of evidence suggests that inhibiting cyclooxygenase-2 (COX-2), the
inducible form of COX, will be an important strategy for preventing cancer. In
this study, we investigated whether resveratrol, a chemopreventive agent found in
grapes, could suppress phorbol ester (PMA)-mediated induction of COX-2 in human
mammary and oral epithelial cells. Treatment of cells with PMA induced COX-2
mRNA, COX-2 protein, and prostaglandin synthesis. These effects were inhibited by
resveratrol. Nuclear runoffs revealed increased rates of COX-2 transcription
after treatment with PMA, an effect that was inhibited by resveratrol.
Resveratrol inhibited PMA-mediated activation of protein kinase C and the
induction of COX-2 promoter activity by c-Jun. Phorbol ester-mediated induction
of AP-1 activity was blocked by resveratrol. These data are likely to be
important for understanding the anticancer and anti-inflammatory properties of
resveratrol.
PMID- 10668497
TI - Modification of dietary habits (Mediterranean diet) and cancer mortality in a
southern Italian village from 1960 to 1996.
PMID- 10668498
TI - Season-specific correlation between dietary intake of fruits and vegetables and
levels of serum biomarkers among Chinese tin miners at high risk for lung cancer.
PMID- 10668499
TI - BRCA 1/2 gene mutation testing-based cancer prevention and the moral concerns of
different types of patients.
PMID- 10668500
TI - Cohort analysis of etiological factors for colorectal cancer following endoscopic
resection of colorectal tumors.
PMID- 10668501
TI - Negative growth regulation of oncogene-transformed human breast epithelial cells
by phytochemicals. Role of apoptosis.
PMID- 10668502
TI - Fecal pH from patients with colorectal tumors.
PMID- 10668503
TI - Oncogenetic information in the hands of physicians and the preventive options of
persons who are not their patients.
PMID- 10668504
TI - Mammalian Cu-containing amine oxidases (CAOs): new methods of analysis,
structural relationships, and possible functions.
AB - This thesis describes new and original experimental results on Cu-dependent amine
oxidases (CAOs), which show that these enzymes can be conveniently and
specifically detected in situ using a peroxidase-coupled activity staining method
with 4-Cl-1-naphtole as hydrogen donor substrate. Even more sensitive in situ
detection can be achieved using a chemiluminescence-based coupled peroxidase
assay which was applied to show that human placenta CAO activity is confined to
maternal vessels. A general purification scheme for CAOs is described, and
applied to purification of different CAOs. Peptide maps and immunological
crossreactivity studies with monoclonal antibodies raised against the purified
enzymes showed that they were closely related. Amino acid sequence data for the
bovine serum CAO showed that they form a separate group (E.C. 1.4.3.6) with no
homology to other enzymes. A cDNA sequence was obtained on the basis of the amino
acid sequence data, and this was found to encode a bovine lung CAO, related to
bovine serum CAO. The genes for bovine lung and bovine serum CAO are
characterized, and Southern blotting analysis of bovine chromosomal DNA shows the
existence of a least one more bovine CAO. The purification of human neutrophil
CAO is attempted, but it is described how lactoferrin, a protein with many
properties in common with CAOs, and with a low degree of sequence identity can
account for many observations on human neutrophil CAO. The products of bovine
serum CAO oxidation of polyamines are characterised, and 3-aminopropanal is found
to be the principal aminoaldehyde produced. Finally, a polyamine-stimulated
binding of human placenta CAO to single-stranded DNA is described, and it is
reported that the DNA-bound CAO is enzymically active and that the oxidation of
DNA-bound polyamines leads to degradation of DNA. In addition to the experimental
results, the properties of polyamines and Cu-dependent amine oxidases are
reviewed. The polyamines spermidine and spermine interact specifically with
nucleic acids and several other molecules. They are synthesised from putrescine,
which is a key regulatory molecule formed from ornithine by ornithine
decarboxylase, a highly inducible and regulated enzyme. The polyamines can be
converted to putrescine by CAOs or spermidine/spermine acetyltransferase and
polyamine oxidase. Putrescine is degraded by CAOs, which are also involved in
degradation of histamine, a mediator of inflammatory processes. CAOs catalyse the
general reaction: R1CH2NHR2 + O2 + H2O-->R1CHO + R2NH2 + H2O2 and in addition to
the catabolism of putrescine and histamine CAOs are involved in regulation of
growth and apoptosis by to the generation of aminoaldehydes and hydrogen peroxide
which have growth inhibitory properties. Several homologous CAOs have been
purified and characterized and they form a family with two subgroups. They are
homodimers with a relative molecular weight of 180,000 and contain Cu2+ and a
modified tyrosine, topaquinone, in the active site. CAOs are present in most
tissues with highest amounts in intestine, kidneys, liver and placenta, but the
cellular distributions and functions of CAOs are still poorly described, partly
due to the use of many different assays and partly due to a broad substrate
specificity of the enzymes. However, polyamines and CAOs seem to form a universal
system contributing to regulation of growth, differentiation, and apoptosis.
PMID- 10668505
TI - [Posttraumatic syringomyelia].
AB - The improvement of preclinical emergency medicine, better surgical and
conservative therapies, and the development of intensive care units and
specialized centers have improved the survival rate for patients with serious
spinal cord injuries. Therefore, more sequelae of chronic spinal cord injuries
such as post-traumatic spinal cord cavitations also occur. The first such case
was described by Bastian in 1867. Generally, these cavitations were diagnosed
from 2 months up to 32 years after the trauma. The overall prevalence of post
traumatic syringomyelia (PTS) is not known; however, with the increasing use of
magnetic resonance imaging (MRI), its diagnosis has increased, ranging from 2.3%
of paraplegic and tetraplegic patients in 1976 and 3.2% in 1985, to nearly 50% in
a selected group of patients in 1991 and 1993. In 1995, a 4.45% incidence was
reported. In our clinic we are currently treating 440 cases of syringomyelia, 140
of which are PTS. Several observations suggest more than one potential mechanism
for the evolution of a post-traumatic cyst or PTS. Various factors, such as
hemorrhage or, in particular, ischemia within the spinal cord, blockage of the
cerebrospinal fluid (CSF) pathways around the cord or localized meningeal
fibrosis either alone or in combination with other factors, may be involved.
Clinically, sensory disturbances, loss of motor function, pain, and modification
of the deep tendon reflexes are observed in most patients. On MRI, PTS is seen as
a longitudinal, cystic cavity within the spinal cord, giving a hypointense signal
on T1-weighted images and a hyperintense signal on T2-weighted images. For
treatment planning it is mandatory to identify the lower and upper end of the PTS
on the MRI.
PMID- 10668506
TI - [CINE-MRT for the study of the effects of regional left ventricular wall motion
disorders on global heart function after a myocardial infarct and
revascularization].
AB - PURPOSE: To determine changes in global cardiac function and mass caused by
infarct-associated regional wall motion abnormalities and to compare the changes
after revascularization in patients with and without improvement of regional
contractility. MATERIALS AND METHODS: 21 patients with regional left ventricular
wall motion abnormalities and associated coronary artery stenoses requiring
revascularization were examined with a Cine FLASH-2D sequence 26 +/- 12 days
after their first myocardial infarction and re-examined three months after
revascularization. Regional contractility and volumes and masses of both
ventricles were determined. RESULTS: After revascularization, regional wall
motion improvement led to decreased left ventricular volumes and improved
ejection fractions, whereas patients with persisting wall motion defects showed
unchanged left ventricular functional parameters. Comparing both groups of
patients, the patients with improvement of regional contractility revealed lower
end-systolic volumes and higher ejection fractions at follow-up. Cardiac masses
and right ventricular parameters were not different, patients with a depressed
right ventricular ejection fraction showed improvement at follow-up. DISCUSSION:
After myocardial infarction, revascularization of the infarct-related coronary
artery leads to an improvement of left ventricular function only if there is also
an improvement of regional contractility. An effect on right ventricular function
was not observed three months after the first small- or middle-sized myocardial
infarction.
PMID- 10668507
TI - [The value of magnetic resonance tomography (MRT) for evaluating ventricular and
anastomotic functions in patients with an extra- or intracardiac total
cavopulmonary connection (TCPC)-modified Fontan operation].
AB - PURPOSE: To evaluate different MR methods (ventricle and flow measurements) for
the postoperative follow-up of hemodynamics in patients with extra- or
intracardial TCPC. MATERIALS AND METHODS: Twenty-eight consecutive patients (14
female, 14 male) within the ages of two to thirty-eight years were examined using
a 1.5 T Gyroscan ACS-NT scanner (Philips, Best, Netherlands). 7 patients had an
extracardial (eTCPC), and 21 an intracardial (iTCPC) tunnel. The calculation of
the ventricular function and muscle mass was performed using "multislice
multiphase" technique by summing up the end-diastolic and end-systolic areas; the
flow measurements were evaluated by phase shift velocity mapping in the superior
vena cava (SVC), inferior vena cava (IVC), right (RPA) and left (LPA) pulmonary
artery. Besides peak and mean velocity, the mean and maximal flow volumes
(ml/min) were calculated. RESULTS: Ejection fraction (EF) of the functionally
single ventricle was within the normal range (mean 57%) in 22/28 patients while
mean muscle mass was elevated in the group with eTCPC (mean 121 g/m2). The mean
flow volumes and the peak velocities in all vessels were higher in the group with
iTCPC as compared to the one with eTCPC. Clinically relevant retrograde flows in
the IVC were only found in the group with iTCPC (7/21), as well as a significant
predominant flow distribution towards the RPA (p < 0.05; Wilcoxon signed-rank
test); in the group with eTCPC towards the LPA (n.s.). CONCLUSIONS: MRI is a
useful method for the assessment of ventricular function and muscle mass in the
follow-up after the modified Fontan operation. MRI flow measurements additionally
provided clinically relevant information about the hemodynamics in Fontan
patients.
PMID- 10668508
TI - [Contrast medium-enhanced MR angiography of the pelvic and leg vessels with an
automated table-feed technique].
AB - PURPOSE: To evaluate contrast enhanced magnetic resonance angiography (ceMRA)
with an automated table-feed technique in patients with arterio-occlusive disease
for imaging of the pelvic and peripheral arteries. METHODS: Twenty-two patients
underwent three-dimensional gadolinium-enhanced MR angiography in a three-step
automatic table-feed technique on a Magnetom Symphony operating at 1.5 Tesla.
Maximum intensity projection images (MIP) were generated from the subtracted and
original studies. Image quality and venous contrast were evaluated by two groups
of observers. 304 vessels (17 patients) were compared with DSA as the standard of
reference. RESULTS: All examinations were performed without any technical
problems. Diagnostic quality of the MIP of subtracted data sets was superior to
that of the unsubtracted images. Venous overlay was 61% in the lower leg. In a
total of 599 observations, a sensitivity of 96% (95%, 82%) and a specificity of
87% (88%, 99%) were high compared to DSA in the detection of significant stenoses
> or = 50% (> or = 75%, occlusions). Interobserver correlation was good (linear
correlation 0.9). CONCLUSION: Stepping-table digital subtraction contrast
enhanced MRA is a promising technique in the diagnosis of peripheral arterio
occlusive disease.
PMID- 10668509
TI - [The optimization of MR cholangiopancreatography].
AB - PURPOSE: To improve the image quality of magnetic resonance
cholangiopancreatography (MRCP) by modification of examination conditions.
MATERIALS AND METHODS: MRCP of 72 patients was performed with a 1.5 T system
(Magnetom Vision, Siemens, 25 mT/m) using two breath-hold techniques, half
fourier acquisition with multislice T2-WI HASTE in MIP technique, and single shot
T2-WI turbo-spin-echo (RARE) with different slice thicknesses. The effects of n
butylscopolamine were assessed. Furthermore, oral contrast agents [barium
sulfate, Fe(II)-gluconate, Fe(II,III)-oxide] in various concentrations were used.
The slice thickness was varied for the RARE sequence (3-7 cm). RESULTS: N
butylscopolamine had no influence on image quality. Improvements could be
attained by variation of the slice thickness. A significant reduction of
disturbing background noise was obtained by oral application of iron gluconate,
or iron oxide-containing contrast media. Similar improvements were achieved with
barium sulfate. CONCLUSIONS: Variation of slice thickness allows an improvement
of MRCP quality. Oral contrast media improve the image quality of MRCP. The
expense of contrast media may be a determinant of choice.
PMID- 10668511
TI - [Fat-saturated, contrast-enhanced spin-echo sequences in the magnetic resonance
tomographic diagnosis of peritoneal carcinosis].
AB - PURPOSE: To evaluate contrast-enhanced, fat-saturated spin echo sequences for the
detection of peritoneal carcinosis with MRI. MATERIALS AND METHODS: 61 patients,
35 with and 26 without peritoneal carcinosis, were examined with abdominal MRI.
Fat-saturated, T1-weighted spin echo sequences were performed before and after
administration of Gd-DTPA. In addition, 22 patients with peritoneal carcinosis
were examined with contrast-enhanced abdominal CT. RESULTS: 32 of 35 patients
with peritoneal carcinosis demonstrated contrast enhancement of the visceral and
30 of 35 enhancement of the parietal peritoneum (91 and 86%, respectively). Wall
thickening of the intestine or parietal peritoneum were noted in 21 and 20 of 35
patients (60 and 57%, respectively), ascites in 18 of 35 patients (51%). False
positive contrast enhancement of the peritoneum was noted in 4 of 26 patients
(15%). In the direct comparison of MRI and CT, 22 of 22 patients versus 7 of 22
patients showed contrast enhancement of the visceral peritoneum (100 and 32%,
respectively). For other signs of peritoneal carcinosis (e.g., ascites,
peritoneal seedings), no differences in diagnostic reliability were demonstrated.
CONCLUSIONS: The use of fat-saturated, spin echo sequences facilitates the
diagnosis of peritoneal carcinosis by artifact reduction and improved detection
of peritoneal contrast enhancement. MRI with fat-saturated sequences was superior
to CT.
PMID- 10668510
TI - [Portal contrast medium-enhanced spiral computed tomography of the liver--the
correlation of radiological and intraoperative findings and the evaluation of
resectability].
AB - PURPOSE: To evaluate the accuracy of spiral computed tomography during arterial
portography (SCTAP) in the detection, localization, and resectability of liver
tumors in a correlative study between radiology and intraoperative findings.
METHOD AND MATERIALS: Retrospectively, SCTAP images of 168 consecutive patients
before liver tumor resection were analyzed. The SCTAP studies (100 ml lopromid
300 by automated injector with a flow of 3 ml/s; slice thickness, table feed and
reconstruction index 5 mm each; scan-delay 30 s; 120 kV; 250 mAs) were evaluated
for the detection, localization, and resectability of focal liver lesions by
three experienced radiologists in consensus and were correlated with
histopathological and intraoperative findings where available (59/168). RESULTS:
The sensitivity of SCTAP for the detection of liver tumors was 91% for all
lesions and 84% for lesions < 1 cm. The specificity was only 19% due to a high
rate of false-positive lesions (30%) and preselection effects. Typical pitfalls
in false positive lesions were inhomogeneous liver perfusion near the portal
vein, the falciform ligament, and the gallbladder (19/42). In 30% of the patients
SCTAP correctly diagnosed inoperability, in 23% the intraoperative tumor
expansion was larger than expected from SCTAP images, which would have changed
operability. CONCLUSION: The SCTAP has a high sensitivity in the detection and
localization of liver tumors and is a valuable method in the preoperative
diagnostic procedure. The method is limited by many false-positive lesions often
due to inhomogeneous liver perfusion and the insufficient evaluation of local
tumor spread. Therefore, SCTAP should be replaced by MRI in the near future.
PMID- 10668512
TI - [The quantification of the magnetization transfer contrast (MTC) effect by
calculating MT quotients: does it yield additional information for the
differentiation of benign and malignant diseases of the locomotor apparatus?].
AB - PURPOSE: To investigate the potential information of the amount of magnetization
transfer effect in musculoskeletal lesions and to compare MT ratios from benign
and malignant musculoskeletal lesions. MATERIAL AND METHOD: 49 patients with
malignant tumors (3 osteosarcoma, 3 malignant fibrous histiocytoma, 4
chondrosarcoma, 2 Ewing sarcomas) and benign lesions (8 chondroma, 2 fibrous
dysplasia, 3 osteoid-osteoma, 6 ganglion cyst, 3 cyst, 3 osteomyelitis, 4
tendinitis, 3 rotator cuff tear, 5 scar tissue) were scanned using routine MRI
protocols including T1- and T2-weighted spin echo as well as T2*-weighted
gradient echo (FFE) sequences at 1.5 Tesla (ACS II, Philips Medical).
Additionally MTC images were generated by combining the FFE sequence and the off
resonance MT technique (-1500 Hz off-resonance frequency, 1770 degrees flip angle
and 50 ms pulse duration). MT ratios were calculated as Slo-Slm/Slo. RESULTS: The
MT ratio of benign lesions was 26 +/- 15%, that of malignant lesions was 22 +/-
6%. The difference was statistically not significant. As expected muscle showed a
high MT ratio of 50 +/- 8%. Scar tissue demonstrated an MT ratio of 39 +/- 16%
which was significantly higher than the tumor MT ratios. CONCLUSION: MTC (MT
ratios) failed to show significant differences between benign and malignant
lesions as was expected due to basic differences in cellularity, rate of mitosis
and chromatin content. MTC might however gain more importance in separating scar
tissue from recurrent tumor in the future.
PMID- 10668513
TI - [The evaluation of experimentally induced injuries to the upper cervical spine
with a digital x-ray technic, computed tomography and magnetic resonance
tomography].
AB - PURPOSE: To compare digital X-ray, CT, and MRI in the evaluation of ligamentous
and osseous lesions in upper cervical spine specimens after artificial
craniocervical injury with the findings of macroscopic preparation. MATERIALS AND
METHODS: A rotation trauma of defined severity was applied to 19 human corpses.
After dissection of the neck specimens, digital X-ray (DIMA Soft P41, Feinfocus),
conventional and helical CT (CTi, High Speed, GE, collimation 1 mm; pitch 1.0),
and MRI were performed from the skull base to C3. The findings were correlated
with the macroscopic results of preparation. MR (Magnetom Vision, Siemens)
imaging was obtained with a 1.5 T system using 2D- and 3D-sequences. RESULTS:
Preparation revealed 6 fractures of the vertebral bodies, 5 fractures of the dens
axis, 1 fracture of the arcus anterior of the atlas, 4 osseous flakes at the
occipital condylus, and 6 lesions of the alar ligaments. Digital radiography
showed all fractures and 4 osseous flakes at the occipital condylus. With
conventional and helical CT, all fractures and all ruptured alar ligaments could
be detected. 2D MRI depicted 9 of the fractures and 3D MRI showed fractures. With
2D MRI, 2 of the 4 osseous flakes at the condylus could be detected and with 3D
MRI one occipital condylus fracture could be depicted. Ligamentous injuries were
visualized by 2D MRI in 2 of 6 cases and by 3D MRI in one case. CONCLUSIONS: In
post-mortem studies, CT was superior to MRI in the visualization of osseous and
ligamentous injuries after trauma of the upper cervical spine. However, these
results are not transferable to patients with rotation injury in general.
PMID- 10668514
TI - [Direct in-vitro measurement of ultrasound velocity in carcinomas, mastopathic
tissue, fatty tissue and fibroadenomas of the female breast].
AB - PURPOSE: The study aimed to investigate ultrasound velocity (SV) in carcinomas,
fibrocystic changes, fibroadenomas and fatty tissue of the female breast by means
of direct in-vitro measurements. We intended to test whether or not differences
in SV exist between the various types of tissue and whether the SV is a useful
criterion to differentiate the different tissues. METHOD: SV was measured by
comparing transmission time of the ultrasound beam through the specimen and
through water. Altogether 40 specimens (12 cancer, 14 fibrocystic changes = FCD,
10 fatty tissues, 3 fibroadenomas, and 1 mixed tissue) were analysed. RESULTS:
Velocity differed significantly between fat (1478.5 +/- 6.5 m/s) and tumor
(1523.1 +/- 5.9 m/s) (p approximately 10(-11)) and between fat and FCD (1526.0 +/
9.0 m/s) (p approximately 10(-12)). No significant differences and much overlap
were seen between the ultrasound velocities of tumors and FCD. Ultrasound
velocity in fibroadenomas (1533.2 +/- 3.8 m/s) was comparable with that in
carcinomas and FCD. CONCLUSIONS: We conclude that ultrasound velocity may add
complementary information to echogenicity (B-scan). Thus, a locally exact
correlation of echogenicity and sound velocity might allow for an improved tissue
characterization.
PMID- 10668515
TI - [The in-vitro evaluation of different embolectomy catheters for the treatment of
acute pulmonary embolism].
AB - INTRODUCTION: Pulmonary embolism (PE) is one of the most common cardiovascular
diseases and frequently causes death. As a rule, PE is treated with thrombolytic
therapy or surgical thrombectomy. MATERIALS AND METHODS: In an in vitro model of
the right lung, we tested four different percutaneous transluminal thrombectomy
devices: a pigtail-catheter with an angled 3-cm (40 degrees) distal tip, the clot
buster, the hydrolyser catheter, and a modified hydrolyser. In 16 consecutive and
repetitive experiments fresh thrombi were inserted and we evaluated the
effectiveness of the system with respect to time, fragment size, reduction of the
Miller score, and handling. RESULTS: Mean intervention times of the catheter
systems were 23 min (pigtail), 14.4 min (modified hydrolyser), 13.8 min (clot
buster), and 10.8 min (hydrolyser). The maximum size of the produced fragments
range from 0.5 to 3.5 mm by the pigtail and from 0.5 to 1 mm by the other
systems. The Miller score reduction was from 14.4 to 2.8 (pigtail), 13.8 to 1.8
(clot-busters), 14.6 to 1.2 (hydrolyser), and 16.4 to 1 (modified hydrolyser).
DISCUSSION: All four catheter systems were effective in the treatment of
pulmonary embolism. The pigtail catheter is the most simple system but more time
consuming and less effective in the fragmentation of emboli and reduction of the
Miller score compared to the other three catheter systems. These systems were
comparable in our model but especially the handling of the hydrolyser was
encouraging.
PMID- 10668516
TI - [A venous aneurysm in the mediastinum as a diagnostic error possibility in
computed tomography].
PMID- 10668517
TI - [Spontaneous thoracic soft-tissue emphysema in a plain-film image. A radiological
approach in a more than unusual etiology].
PMID- 10668518
TI - [Pseudoaneurysm of the A. epigastrica inferior after laparoscopic
cholecystectomy].
PMID- 10668519
TI - [Nonparasitically induced renal lymph reflux with chyluriae].
PMID- 10668520
TI - [A triple ureter with an ectopic opening into the vagina].
PMID- 10668521
TI - Early aggressive DMARD therapy: the key to slowing disease progression in
rheumatoid arthritis.
AB - Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint
inflammation, joint destruction, progressive disability, and premature death.
Patients at risk for poor prognoses can be identified by a variety of prognostic
indicators. These include sociodemographic factors (e.g., older age, female sex),
clinical indicators (e.g., higher joint counts), laboratory variables (e.g.,
higher erythrocyte sedimentation rate, high rheumatoid factor titer), and
radiographic indicators (e.g., the presence of bone erosions). Patients with a
poor prognosis, as evidenced by the presence of one or more indicators of poor
outcome, should be treated promptly and aggressively with disease-modifying
antirheumatic drugs (DMARDs) or combination DMARD therapy to limit or prevent
further disease progression. Limiting the severity of RA with early and
aggressive treatment is the best way to minimize the dire consequences of
untreated or inadequately treated disease.
PMID- 10668522
TI - Disease modification in rheumatoid arthritis with leflunomide.
AB - Rheumatoid arthritis (RA) is characterized by chronic inflammation and
irreversible destruction of articular cartilage and bone. Disease progression as
assessed by radiographic imaging of structural joint damage is a key outcome
measure in RA. Joint damage is especially rapid during early phases of RA, thus
the current trend of early aggressive therapy with disease-modifying
antirheumatic drugs (DMARDs). Radiographic analysis of disease progression with
the novel DMARD leflunomide was compared to methotrexate and sulfasalazine in two
large, placebo-controlled, randomized Phase III studies (N = 580). The results as
indicated by changes in x-ray scores indicate that leflunomide and both active
comparators slow disease progression significantly better than placebo (P < or =
0.01). Slowing of disease progression with leflunomide was similar to
sulfasalazine at 6 months but better than methotrexate (P < or = 0.049) at 12
months. These data verify the ability of leflunomide to slow disease progression
and confirm its disease-modifying potential.
PMID- 10668523
TI - Efficacy and safety of the new DMARD leflunomide: comparison to placebo and
sulfasalazine in active rheumatoid arthritis.
AB - The efficacy and safety of the novel DMARD leflunomide was compared to placebo
and sulfasalazine in a randomized, double-blind study. At Week 24, leflunomide
significantly reduced tender and swollen joint counts and physician and patient
assessment scores compared to placebo (P < 0.001). Response rates with
leflunomide were significantly greater than placebo: ACR 20% (55% vs 29%, P =
0.0001). Comparable response rates were observed with sulfasalazine (ACR 20%:
56%). Leflunomide significantly improved HAQ scores compared to placebo or
sulfasalazine (P < 0.009). The onset of action with leflunomide was rapid and was
seen as early as Week 2. Radiographic disease progression was significantly
slower with leflunomide than placebo (P < 0.01). Leflunomide was well tolerated.
No long-term safety issues were reported with leflunomide in patients who opted
to continue treatment for up to 2 years. Efficacy of leflunomide in the treatment
of RA was maintained at 2 years.
PMID- 10668524
TI - Leflunomide improves quality of life in rheumatoid arthritis.
AB - Functional disability in rheumatoid arthritis (RA) interferes with activities of
daily living and severely affects patient quality of life. It results in
increased levels of work disability and high medical costs. A new goal of RA
therapy is to reduce or prevent functional disability. Patients' perception of
overall health status in RA was assessed using several instruments (HAQ, MHAQ, SF
36, and PET) in Phase III double-blind, placebo-controlled, randomized trials
comparing the new DMARD, leflunomide to sulfasalazine and methotrexate.
Leflunomide significantly improved patient quality of life compared to placebo in
both the European (P = 0.0001) and North American (P = 0.0001) studies. Reduction
in HAQ scores with leflunomide (-0.50 vs -0.29; P = 0.0086) was significantly
greater than sulfasalazine. Leflunomide also significantly reduced MHAQ scores
versus methotrexate (-0.29 vs -0.15; P < or = 0.05). These changes were seen as
early as Week 4. These results highlight the efficacy of leflunomide in RA
therapy.
PMID- 10668525
TI - Leflunomide versus methotrexate: a comparison of the European and American
experience.
AB - This paper compares and contrasts the results of two major Phase III clinical
trials that compared the efficacy and safety of leflunomide, a new disease
modifying antirheumatic drug (DMARD), and methotrexate. In both the American
trial (US301) and the multinational trial (MN302), patients with active
rheumatoid arthritis (RA) were given either leflunomide (20 mg/day after a
loading dose of 100 mg/day for 3 days) or methotrexate (7.5-15 mg/week) for 52
weeks. US301 was also placebo-controlled. Folate supplementation was mandatory in
US301 but was given to < 10% of the patients in MN302. In US301, American College
of Rheumatology (ACR) 20% response rates and improvement in tender and swollen
joints were significantly better than placebo in both treatment groups, but were
not significantly different from each other. Both treatments significantly
retarded radiographically assessed progression of RA compared to placebo, but the
degree of retardation was significantly greater with leflunomide. In MN302, the
ACR response rate and improvement in tender and swollen joints with leflunomide
were similar to those seen in US301. The ACR response rate and improvements in
all efficacy variables with methotrexate were significantly greater than with
leflunomide, however. Radiographically assessed disease progression was not
statistically different with the two treatments. Use of methotrexate without
folate in MN302 was associated with a higher incidence of clinically significant
elevations of liver enzyme levels. These results indicate that both leflunomide
and methotrexate are effective DMARDs. The symptomatic relief provided by both
drugs is similar when they are given with folate supplementation.
PMID- 10668527
TI - What is your diagnosis? Oblique fracture of the odontoid process from the axial
body.
PMID- 10668526
TI - Thoughts on the transmission of Sarcocystis neurona.
PMID- 10668528
TI - A veterinarian's recourse for libelous language.
PMID- 10668529
TI - Compendium of animal rabies prevention and control, 2000. The National
Association of State Public Health Veterinarians.
PMID- 10668530
TI - Mortality rates and causes of death among emaciated cats.
AB - OBJECTIVE: To determine mortality rates and causes of death for thin (i.e., lean
or emaciated) cats and, if mortality rates were high, to determine factors
associated with risk that cats would be thin. DESIGN: Cohort study. ANIMALS:
1,138 cats examined at 27 private veterinary practices in the northeastern United
States. PROCEDURE: Body condition of the cats was scored (emaciated, lean,
optimally lean, optimal, heavy, obese) between 1991 and 1992. Follow-up
information on whether cats had developed any illnesses, whether cats had died,
and, if cats had died, cause of death was obtained between 1994 and 1996.
Mortality risk for emaciated cats was estimated, using cats in optimal condition
as the reference group. RESULTS: Survival curves for emaciated cats were
significantly lower than those for cats of other body conditions. Compared with
cats in optimal condition, emaciated cats were 4.4 times as likely to die during
the follow-up period. However, after adjusting for age and excluding cats that
died within 1 year after body condition was scored, emaciated cats were no longer
significantly more likely to die. Emaciated cats were more likely to die of an
unknown cause than were cats of optimal condition. Risk factors for emaciated
body condition included preexisting illness, age, and Siamese breed. CONCLUSIONS
AND CLINICAL RELEVANCE: Results suggest that emaciated cats had a significantly
higher risk of death, compared with cats in optimal body condition. Serious
illness and advancing age accounted for much, and perhaps all, of this increased
risk of death.
PMID- 10668531
TI - Ophthalmomyiasis interna anterior associated with Cuterebra spp in a cat.
AB - An 8-year-old domestic shorthair cat was examined for severe anterior uveitis of
the right eye that was unresponsive to aggressive treatment with anti
inflammatory drugs and for a possible intraocular parasite or foreign body
trapped within a large fibrin clot in the anterior chamber. Surgical exploration
of a presumed entry site on the caudal aspect of the third eyelid led to
keratotomy and removal of a larval parasite later identified as a first instar
Cuterebra spp. Aggressive treatment with anti-inflammatory drugs was continued
after surgery, and intraocular pressure was monitored closely to ensure that the
cat did not develop glaucoma. Two weeks after surgery, the cat had vision in the
affected eye, with resolving uveitis and a normal fundus. Six weeks after
surgery, the uveitis continued to resolve; however, the cat did not have vision
in the affected eye, and examination of the fundus revealed retinal atrophy. In
contrast to the condition in humans, a Cuterebra spp larval infection within the
eye of cats may cause not only an intense, acute inflammatory reaction, but also
retinal degeneration and blindness despite prompt surgical removal.
PMID- 10668532
TI - Retrobulbar pseudotumor of the orbit in a cat.
AB - Idiopathic nonspecific inflammatory disease of the orbit (orbital pseudotumor)
was diagnosed detected in a cat. The cat had progressive lagophthalmia,
keratitis, and decreased motion of the right eye. Four months later, the left eye
was affected in a similar manner. Response to antibiotics and immunosuppressive
agents was not detected. Computed tomography of the brain and orbits revealed
bilateral thickening of the sclera and episcleral tissues. Bilateral exenteration
of the eyes was required because of worsening clinical signs or corneal
perforation. Histologic examination revealed proliferation of spindle cells and
fibrovascular tissue within and adjacent to the sclera.
PMID- 10668533
TI - Bacteria associated with pyothorax of dogs and cats: 98 cases (1989-1998).
AB - OBJECTIVE: To determine the organisms most commonly isolated from pleural fluid
from dogs and cats with pyothorax. DESIGN: Retrospective study. ANIMALS: 51 dogs
and 47 cats. PROCEDURE: Results of bacteriologic culture of pleural fluid samples
obtained by means of thoracentesis were obtained from medical records. To obtain
information on in vitro antimicrobial susceptibility of organisms commonly
isolated from dogs and cats, records of all dogs and cats examined during 1998
were reviewed, and information was obtained on identity and in vitro
antimicrobial susceptibility of aerobic organisms isolated from samples other
than urine or urinary tract samples. RESULTS: Median ages of dogs and cats were 4
years. Bacteria were isolated from pleural fluid samples from 47 of 51 (92%) dogs
and 45 of 47 (96%) cats. Obligate anaerobic bacteria were isolated from 28 dogs
and 40 cats. A mixture of obligate anaerobic and facultative bacteria was
isolated from 17 dogs and 20 cats. Samples from cats most often yielded a member
of the nonenteric group (most commonly members of the genus Pasteurella), whereas
those from dogs more often yielded a member of the family Enterobacteriaceae
(most commonly E coli). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that
antimicrobial agents chosen for the initial treatment of dogs and cats with
pyothorax should be active against a mixture of obligate anaerobic and
facultative bacteria.
PMID- 10668534
TI - Influence of open surgical correction on intermediate-term outcome in dogs with
subvalvular aortic stenosis: 44 cases (1991-1998).
AB - OBJECTIVE: To compare outcome and intermediate-term survival for dogs undergoing
open surgical correction of subvalvular aortic stenosis (SAS) with those for dogs
with SAS that did not undergo surgery. DESIGN: Retrospective study. ANIMALS: 44
dogs with congenital SAS. PROCEDURE: Maximum instantaneous systolic pressure
gradients were determined by use of Doppler echocardiography. Cardiopulmonary
bypass and open surgical correction of SAS (membranectomy with or without septal
myectomy) was performed in 22 dogs, whereas 22 dogs did not undergo surgical
correction. Cumulative survival was compared between surgical and nonsurgical
groups, using Kaplan-Meier nonparametric analysis and a Mantel-Cox log-rank test.
RESULTS: Initial systolic pressure gradients were not significantly different for
dogs undergoing surgery (128 +/- 55 mm Hg), compared with those that did not
undergo surgery (117 +/- 57 mm Hg). Systolic pressure gradients were
significantly decreased after surgery in dogs that underwent surgery (54 +/- 27
mm Hg). Cumulative survival was not significantly different between dogs in the
surgical and nonsurgical groups. Censoring surgery-related mortality in the
analysis still did not reveal a significant difference in cumulative survival
between the surgical and nonsurgical groups. CONCLUSIONS AND CLINICAL RELEVANCE:
Despite reductions in the systolic pressure gradient and possible associated
improvement in exercise tolerance, a palliative benefit on survival was not
documented in dogs undergoing surgery for SAS.
PMID- 10668535
TI - Complications associated with the use of indwelling epidural catheters in dogs:
81 cases (1996-1999).
AB - OBJECTIVE: To evaluate complications associated with use of indwelling epidural
catheters in dogs in a clinical setting. DESIGN: Retrospective clinical study.
ANIMALS: 81 client-owned dogs. PROCEDURE: Medical records were reviewed for dogs
in which a 19-gauge epidural catheter was placed percutaneously at L7-S1 and
advanced to the point of maximum efficacy for pain control (between L7 and T4,
depending on the procedure). Catheters were used to provide perioperative
epidural analgesia during surgeries that included perineal (n = 6), hind limb
(33), abdominal (43), thoracic (5), forelimb (2), and cervical (1) procedures.
RESULTS: Catheters were maintained in situ from 1 to 7 days (mean, 2.3 days;
median, 2.0 days). Sixty-four dogs did not have complications; 17 dogs had minor
complications. Catheter dislodgement was the most common complication (13/80
[16%] dogs). Catheter site contamination without inflammation developed in 2
(2.4%) dogs; inflammation at the catheter site developed in 2 (2.4%) dogs but was
not related to duration of time the catheter was in place. Complications were not
serious and did not require treatment other than catheter removal. Dogs that
dislodged their catheters were significantly younger (mean, 2.9 years; median,
2.0 years) than other dogs (mean, 6.2 years; median, 6.0 years). Dogs that
received femoral fracture repair dislodged their catheters more often (62.5%)
than dogs undergoing other procedures (10.9%). CONCLUSIONS AND CLINICAL
RELEVANCE: The complication rate associated with temporary epidural
catheterization of dogs appears to be low, and complications generally are not
serious.
PMID- 10668537
TI - Productivity characteristics of high-performing commercial swine breeding farms.
AB - OBJECTIVE: To determine productivity characteristics of high-performing swine
breeding herds in the United States and to determine associations among number of
litters per mated female per year (LMFY), number of pigs weaned per sow (PWS),
and lactation duration. DESIGN: Cohort study. SAMPLE POPULATION: 1997
productivity records for 685 herds. PROCEDURE: Herds were ranked on the basis of
number of pigs weaned per mated female per year, and herds in the upper 10th
percentile of this ranking were designated as high-performing herds. Productivity
measurements for these herds were compared with values for the remaining herds.
RESULTS: High-performing herds had shorter lactation durations and higher mean
breeding female inventories than did the remaining herds. High-performing herds
also had better reproductive efficiency and used farrowing facilities more
efficiently than did the remaining herds. For the high-performing herds,
lactation duration was significantly associated with PWS but was not
significantly associated with LMFY. In contrast, for the remaining herds,
lactation duration was not significantly associated with PWS but was
significantly associated with LMFY. CONCLUSIONS AND CLINICAL RELEVANCE: Results
suggest that high-performing commercial swine farms could increase PWS by
improving preweaning mortality rate and number of pigs born alive, but that LMFY
was already maximal. For other herds, however, shortening lactation duration
would likely decrease farrowing interval and improve efficiency of the
reproductive cycle without reducing litter size.
PMID- 10668536
TI - Treatment and outcome of dogs with leptospirosis: 36 cases (1990-1998).
AB - OBJECTIVE: To characterize serologic and clinical features and outcome of dogs
with leptospirosis that were treated conservatively (i.e., medical management
alone) or with hemodialysis. DESIGN: Retrospective study. ANIMALS: 36 dogs with
leptospirosis. PROCEDURE: History; results of physical examinations,
ultrasonography, and serologic, hematologic, and serum biochemical analyses; time
to resolution of azotemia; and outcome were obtained from medical records. Dogs
were treated conservatively (n = 22) or with hemodialysis (14). RESULTS: Between
1990 and 1998, amount of rainfall was positively correlated with number of cases
of leptospirosis identified per year. Serum antibodies against 6 Leptospira
serovars were measured, and titers were highest to Leptospira pomona in 16 (44%)
dogs, L bratislava in 9 (25%) dogs, and L hardjo in 1 (3%) dog. Eight (22%) dogs
had equally high titers to L pomona and L bratislava, 1 (3%) had equally high
titers to L grippotyphosa and L canicola, and 1 (3%) had high titers to L
grippotyphosa, L pomona, L canicola, and L bratislava. During initial evaluation,
all dogs were azotemic. Thirty (83%) dogs survived, including 12 of 14 (86%) dogs
treated with hemodialysis and 18 of 22 (82%) treated conservatively. Serum
creatinine concentration was similar in both groups after resolution of clinical
signs. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with L pomona and L
bratislava was recognized as a cause of leptospirosis in dogs, and resulted in
development of acute renal failure with various degrees of azotemia. Prognosis
for dogs with mild to moderate azotemia was good with conservative treatment,
whereas treatment with hemodialysis appeared to improve prognosis for dogs with
severe azotemia.
PMID- 10668538
TI - Diagnosis and treatment of torsion of the spiral colon in an alpaca.
AB - A 14-year-old 61.7-kg (136-lb) alpaca was examined for colic of 24 hours'
duration. An exploratory celiotomy was performed because of lack of response to
medical treatment and ultrasonography revealed an abnormally large amount of free
fluid in the peritoneal cavity. Exploration of the abdomen revealed a 20-cm
diameter mass, consisting of most of the ascending colon. The spiral colon was
thick and edemetous, and it was decided to resect the spiral colon. Following a
few complications, the alpaca was discharged 17 days after surgery. Colic in
camelids is considered a severe problem because clinical signs are subtle and
often not recognized until the condition is untreatable. Camelids are reported to
be stoic animals, and may have few signs of pain despite severe abdominal
disease. Alpacas with signs of abdominal pain should undergo early and complete
physical, laboratory, and diagnostic imaging evaluations. Rapid identification of
the need for surgery is vital for a successful outcome.
PMID- 10668539
TI - [Diabetic ketoacidosis presenting as acute abdomen].
AB - Three patients, two women aged 21 and 67 and a man aged 43 years, presented at
the emergency department with diabetic ketoacidosis and abdominal symptoms
mimicking an acute abdominal condition. In two of them laparotomy was performed
which proved to be negative. Abdominal symptoms resolved after correction of
metabolic, fluid and electrolyte disturbances. Symptoms indicating a possible
diagnosis of acute abdomen have to be regarded as being compatible with diabetic
ketoacidosis per se. However, a potential acute abdominal problem prompting
surgical intervention should not be overlooked; it may have been the
precipitating factor for diabetic ketoacidosis.
PMID- 10668540
TI - [Cavernous sinus syndrome].
AB - A clear and concise description and clinical interpretation of the cavernous
sinus syndrome are lacking. Pathological changes in or around the cavernous sinus
may lead to failure of eye muscle nerves and of one or more branches of the
trigeminal nerve. The clinical signs of the cavernous sinus syndrome are
combinations of failure of these cranial nerves sometimes with exophthalmus.
Because many nerves can be wholly or partially involved in the syndrome, there is
no clinical uniformity and the cavernous sinus syndrome has never been well
defined. A neurotopographical classification is proposed in order to simplify the
multiple interpretations of the cavernous sinus syndrome. The classical cavernous
sinus syndrome is divided into three syndromes: the syndrome of the superior
orbital fissure, the syndrome of the lateral wall of the cavernous sinus and the
central cavernous sinus syndrome.
PMID- 10668541
TI - [Endovascular stent implantation as a treatment for iliac artery disease].
AB - A stent is an endovascular prosthesis that may be used in the treatment of
intermittent claudication caused by lesions of the A. iliaca communis and the A.
iliaca externa in which earlier balloon dilatation has proved insufficiently
effective. The expansion is caused by inflation of an angioplasty balloon
(plastic remodelling: Palmaz stent) or by self-expansion due to elastic
transformation as in the Wail stent or to thermic memory metal, as in the
Memotherm stent. Evaluation of the literature shows that stent placement is a
safe method of treatment. The proportion of initial technical success appears to
be higher than that of balloon angioplasty, especially in the treatment of total
occlusions. The haemodynamic situation immediately after treatment also appears
to be better in case of stent placement. Long-term comparison of the clinical
efficacy is not well possible because the published studies differ with regard to
patient population, definition of indication and criteria of success.
PMID- 10668542
TI - [Critical review of anti-influenza drugs].
AB - Neuraminidase inhibitors such as zanamivir and oseltamivir belong to a new class
of antiviral drugs for the treatment and prevention of influenza. As yet however,
the therapeutic efficacy of these drugs (shortening of recovery time by
approximately one day) has only been demonstrated in healthy adults affected by
influenza A, but not in risk groups and in influenza B disease, whereas studies
of prophylactic efficacy are still going on. Neither do these drugs impact on
viral spread, a public health risk against which the economic advantages of early
work resumption have to be weighed. Since flu symptoms can be caused by other
germs than the influenza A or B virus, caution in prescribing these drugs seems
warranted, also to prevent the development of drug resistance. In addition, when
designing therapeutic efficacy trials in risk groups, selecting the rate of
secondary complications and death may be more adequate as clinical endpoint than
(economically important) duration of illness.
PMID- 10668543
TI - [Measles epidemiology in the Netherlands: a exploratory analysis of
notification].
AB - OBJECTIVE: Explorative analysis of the effects of vaccination policy on measles
incidence. DESIGN: Retrospective study and mathematical modelling. METHOD:
Analysis of national and regional case notifications of measles provided by the
Inspectorate of Health in the Netherlands over the period from January 1976 (when
vaccination was started) through September 1999. Also computer simulations with a
mathematical epidemic model of measles were used to calculate the incidence of
measles from 1976 onwards. RESULTS: According to the model results, measles
should not persist with the current vaccination programme. However, the case
notification data showed that measles appeared to persist at a nation-wide level.
At a regional level, measles did not persist, not even in regions with low
vaccine coverage. A possible cause of the unexpected persistence at the national
level is the asynchronous regional course of the 6-year epidemic cycle of
measles, where measles infection 'jumps' from one region to the other.
PMID- 10668544
TI - [Children with stumbling gait due to acute spinal cord compression].
AB - Three previously healthy children, two girls aged 2 and almost 5 years and a boy
aged 20 months, developed a progressively stumbling gait within days. In two this
occurred after a period of weeks during which they complained of, or seemed to
have back pain. In all three cases acute spinal cord compression by a malignant
tumour was diagnosed. Histological examination revealed Ewing sarcoma,
granulocytic sarcoma and T-cell lymphoma. Surgical decompression led to complete
neurological recovery. Although rare, acute spinal cord compression during
childhood is a medical emergency because of the risk of neurological morbidity.
Back pain, weakness and a stumbling gait usually are the first symptoms. Sensory
symptoms and sphincter dysfunction may develop later. Early recognition is
essential, as prognosis depends on neurological findings and duration of symptoms
when treatment is started.
PMID- 10668545
TI - [Transmission of hepatitis B virus by a surgeon].
PMID- 10668546
TI - [Transmission of hepatitis B virus by a surgeon].
PMID- 10668547
TI - [Transmission of hepatitis B virus by a surgeon].
PMID- 10668548
TI - [Clinical thinking and decision making in practice. An elderly patient with
vertigo and high sedimentation rate].
PMID- 10668549
TI - [In-vivo analysis of nitric oxide].
PMID- 10668550
TI - [Analysis of extracellular substances with microdialysis].
PMID- 10668551
TI - [Change in expression pattern of myosin heavy chain isoforms in soleus muscle of
the rats after hindlimb suspension].
PMID- 10668552
TI - [Effect of 2,5-hexanedione on myosin heavy chain isoform content in perineal
muscles of the rats].
PMID- 10668553
TI - The painted Amsterdam anatomy lessons: anatomy performances in dissecting rooms?
AB - The Anatomy Lesson of Dr. Nicolaes Tulp, painted by Rembrandt in 1632, has
recently been fully restored. From 02-10-98 to 10-01-99 this painting and some
other Amsterdam painted anatomy lessons were exhibited in the Mauritshuis in The
Hague, with the title "Rembrandt under the scalpel". The unique Tulp painting is
one of those portraits painted in the tradition of the famous group portraits
which flourished in 17th-century Holland, a predominantly urban, middle-class
society where the main patrons of the arts were the leading citizens of the
various towns. Moreover, it is a portrait in the tradition of the anatomy lessons
especially painted for the Guild of Surgeons for their Guild Room. Nine such
lessons have been painted for the guild and are still to be found in Dutch
museums (Mauritshuis and Amsterdam Historical Museum). The anatomy lesson of
Prof. Andreas Bonn, dated 1792, as well as some group portraits of the leading
persons of the guild also play an important role in the Amsterdam group
portraits. In 1925 the Amsterdam anatomist Louis Bolk commissioned Martin
Monnickendam to paint another anatomy lesson. The restoration of the painting of
Dr. Tulp has provided new information concerning the original composition of
Rembrandt and the later additions. However, from an anatomical point of view, it
is doubtful whether the Amsterdam anatomy lessons depict a real contemporary
anatomical demonstration. They provide, together with archival sources, reliable
information about the praelectores anatomiae and the leading persons of the
guild, but fail to give much information about the dissecting room, the anatomy
theatre or the procedure. The anatomical demonstration procedures of the guild
are discussed in relation to the painted anatomy lessons.
PMID- 10668554
TI - On the innervation of the donkey testis.
AB - The innervation pattern of the adult donkey testis was investigated by
immunohistochemistry and acetylcholinesterase histochemistry. Autonomous nerves
reach the testis by three access-routes as funicular, mesorchial and caudal
contributions. From these, the funicular contribution accompanying the testicular
artery and pampiniform plexus is the strongest and most important one. Testicular
innervation in the donkey is not uniform. The spermatic cord as well as the
epididymal region, cranial and caudal poles (tunica albuginea and adjacent
parenchyma and stroma) are well innervated, mostly by vascular nerves. Towards
the free border of the testis, the nerve density in the tunica albuginea
decreases continuously. In the interior of the gonad, approximately one third of
the testis, situated between the free border and the central mediastinum, is
practically devoid of any innervation. The great majority of the testicular
nerves demonstrated by the present techniques are non-myelinated vascular nerves
which react positive for dopamine-beta-hydroxylase and tyrosine hydroxylase, thus
representing postjunctional sympathetic fibers. Many of these also contain
neuropeptide Y. The testicular innervation of the donkey testis is free of
cholinergic fibers. Calcitonin gene-related peptide-containing nerves are found
as solitary varicose axons in the wall of blood vessels, but also in stromal
connective tissue of the spermatic cord, tunica albuginea and septula testis.
PMID- 10668555
TI - Verification of the two-dimensional disector, a method for the unbiased
estimation of density and number of myelinated nerve fibers in peripheral nerves.
AB - Quantification of the number of myelinated fibers in peripheral nerves is a
common requirement in quantitative morphology. This parameter provides important
information on the consequences of various physiological, pathological and
experimental conditions on the nerve structure and is one of the main indicators
of success of peripheral nerve repair. In this paper, the theoretical rationale
for the application of stereological principles to obtain unbiased estimates of
the density and total number of myelinated fibers in peripheral nerves is
discussed and a simple stereological method is described. The method is applied
together with a systematic random sampling scheme, that was optimized for the
purposes of the present study, and with sampling scheme analysis by calculating
the coefficient of error (CE). The stereological method, which consists of a two
dimensional variation of the classical disector procedure (two-dimensional
disector), and the sampling scheme are verified by comparing estimates with the
true density and total number of myelinated fibers in peripheral nerve trunks
where true values have been accurately determined by extensive counting. The
verification of the 2-D disector method, both of normal and regenerated nerves,
showed that estimates of density and total number of myelinated nerve fibers are
unbiased. The method also proved to be efficient (time-saving): Estimation of
density and total number of myelinated fibers in a single nerve takes about 2-3
hours.
PMID- 10668556
TI - Afferent connections of the caudal raphe pallidus nucleus in rats: a study using
the fluorescent retrograde tracers fluorogold and true-blue.
AB - Afferent connections to the caudal region of the nucleus raphe pallidus (RPa) in
rats were studied using fluorogold and true-blue as tracers. Due to its ability
to produce limited injection sites, true-blue proved to be more appropriate than
fluorogold for studying long distance connections in a narrow structure such as
the RPa. Fluorescent, retrogradely-labeled perikarya were found in the preoptic
area (median, medial and lateral nuclei), hypothalamus (anterior, dorsal, lateral
and posterior areas, and the peri- and paraventricular nuclei), zona incerta,
central gray (dorsal, ventral and ventro-lateral), reticular formation of the
brainstem, trigeminal spinal nuclei and in the spinal cord (laminae V-X at
thoracic, lumbar and sacral levels). This connection pattern suggests the
involvement of the RPa in autonomic, somatic and endocrine functions.
PMID- 10668557
TI - Angioarchitectural form, functional distributive pattern and classification of
the filiform papillae on the crossbred Japanese cat tongue anterodorsal surface
in scanning electron microscopic specimens.
AB - The purpose of this study was to undertake a three-dimensional comparative
observation of the angioarchitectural form, functional distributive pattern and
classification of the filiform papillae (FiP) as they appear on the entire dorsal
surface of the front of the Japanese cat tongue using microvascular cast
specimens (MVCS). By means of the corrosive resin casting technique, the MVSC of
the FiP of the cat tongue were prepared and examined in detail under the scanning
electron microscope (SEM). On the frontal half of the anterodorsal surface of the
anterior tongue, types I-V of the FiP are arranged in the form of a A with the
point in the direction of the apex and in an oblique line running from the antero
central to both postero-peripheral regions. In the rear half of the anterodorsal
surface of the anterior part of the tongue, types I-V of the FiP are arranged in
the form of a V with the point in the direction of the root and in an oblique
line running from both antero-peripheral regions to the postero-median region or
towards the pharynx on the anterior centro-dorsal surface of the tongue. The FiP,
arranged in an oblique line running fron the central to the apical part of both
the periphery and the pharyngeal region of the cat tongue, can be classified into
five types (Types I-V) according to the shape and size of the main process (MP),
numbers of the accessory processes (AP) and regional position of the lozenge
arrangement. FiP Types I-III consisted of an MP which contained a large spoon
shaped and concave network process, and the AP contained a bundle of spin-like
processes arranged radially at the anterior basal margin of the MP. FiP Types IV
and V consisted only of MP. It was conjectured that the lozenge arrangement of
the A and V form FiPs, classified into five types (Types I-V) from the frontal
portion of the anterodorsal surface toward the pharynx on the front of the
tongue, play a functionally assistant role in the mastication of food and sucking
of liquid, including milk.
PMID- 10668558
TI - Angioarchitectural form, functional distributive pattern and classification of
the fungiform papillae on the crossbred Japanese cat tongue anterodorsal surface
in scanning electron microscopic specimens.
AB - The purpose of this study was to undertake a three-dimensional comparative
observation of the angioarchitectural form, functional distributive pattern, and
to classify the fungiform papillae (FuP) found sporadically and geometrically on
the oblique lines of the filiform papillae (FiP) on the entire dorsal surface of
the crossbred Japanese cat foretongue in microvascular cast specimens (MVCS). By
means of the corrosive resin casting technique, the MVCS of the FuP of the cat
tongue were prepared and examined in detail under the scanning electron
microscope (SEM). With regard to the arrangement of FiPs and FuPs on the frontal
half of the antero-dorsal surface of the cat foretongue, FiP types I-V and FuP
types I-IV are arranged a A form with the point in the direction of the apex and
in an oblique line running from the antero-central portion to both postero
peripheral portions. In the rear half of the antero-dorsal surface of the
foretongue, FiP types I-V and types FuP I-IV are arranged in a V form with the
point in the direction of the radix and in an oblique line running from both
antero-peripheral portions to the postero-median portion or towards the pharynx
on the anterior centro-dorsal surface of the cat foretongue. With the FuP
arranged in the medial zone (M) and peripheral zone (P) running from the central
to the apical parts, both the peripheral parts and the pharyngeal can be
classified into four types (FuP types I-IV) according to the shape and size of
the main process (MP), the number of the accessory processes (AP) and the
regional position of the lozenge arrangement. FuP Types I-III consisted of a MP
containing a large half oval, network-like process, and the AP contained a bundle
of spine-like processes arranged radially in a circle at the anterior basal
margin of the MP. The FuP Type IV was made up of only one MP. In the central zone
(C) of a lozenge part arranged in the A and V forms, there was no FuP as a taste
organ. It was assumed that in the lozenge arrangement of the A and V forms,
except for the C zone, FuPs could be classified into four types (FuP types I-IV)
from the frontal portion of the antero-dorsal surface toward the pharynx on the
foretongue, and would play an assistant functional role in receiving the sense of
taste of foods and liquids.
PMID- 10668559
TI - Anomalous artery directly connecting the external and internal carotid arteries.
AB - An anomalous artery directly connecting the external with the internal carotid
artery was encountered on the right side of a 68-year-old Japanese female
cadaver. This anomalous artery (5 mm in diameter, 12 mm in length) branched out
from the posterior aspect of the external carotid at the level of the origin of
the lingual artery, ran obliquely upward posteriorly along the course of the
hypoglossal nerve, and was confluent with the anterior aspect of the internal
carotid artery. No other variations were found in the morphological aspects of,
or in the anatomical relationships between, the carotid arteries and their
surrounding structures on either side. The carotid body-like structure was
observed at the carotid bifurcation and was innervated by small branches of the
glossopharyngeal, the vagus and the sympathetic trunk. Embryologically, it is
conceivable that this anomalous artery may have derived from the right second
branchial arch artery, although there is no abnormality in other derivative
structures of the second pharyngeal arch. There may have been no effect from this
anomaly on the functions of the arterial blood flow and blood supply under normal
circumstances in the present case, but this report may be of embryological
significance and contribute some insight into the mechanisms of the formation of
the carotid circulation systems.
PMID- 10668560
TI - The relationship between the tibialis posterior tendon and the accessory
navicular.
AB - Out of a total of 116 cadaver feet, 29 specimens were selected by means of
palpation of the tuberosity of navicular for a possible presence of the accessory
navicular. They were then radiographed and the accessory navicular was detected
in ten. Also three fresh amputation specimens with an accessory navicular were
added to the study. A total of 13 legs was dissected and in nine of them, the
tibialis posterior tendon inserted directly into the accessory navicular without
extending to the sole of the foot. In these feet, the second part of the tibialis
posterior tendon originated from the accessory navicular, extending to the normal
insertions. There was no connection between these two parts and when traction was
applied to either one, no movement was observed in the other. Also a
fibrocartilaginous mass was detected in four specimens, probably formed to resist
the friction between the tendon and the bone. These results may explain the
pronated foot in the presence of the navicular, due to the loss of the function
of the tibialis posterior tendon.
PMID- 10668561
TI - [Plastination histologic investigations on the inserting pars terminalis
aponeurosis dorsalis of three-sectioned fingers].
AB - With the help of thick transparent cross-sections of fingers, manufactured by
plastination histology, it has been shown that fibres of the extensor aponeurosis
insert not only the way described in current textbook on the basis phalangis
distalis and on the capsule of the distal interphalangeal joint. Our studies
prove that parts of the dorsal extension plate insert dorsally to the nail matrix
and others run over the edge of the basis phalangis to the proximal part of the
diaphysis where they intermingle with the periost of the phalanx.
PMID- 10668562
TI - Expression of inositol trisphosphate receptors.
PMID- 10668563
TI - Basolateral store-operated Ca(2+)-entry in polarized human bronchial and colonic
epithelial cells.
AB - Bronchial epithelial cells respond to extracellular nucleotides from the luminal
and basolateral side activating Cl- secretion via [Ca2+]i increase. In this study
we investigated the differences of apically (ap) and basolaterally (bl)
stimulated [Ca2+]i signals in polarized human bronchial epithelial cells
(16HBE14o-). Specifically we investigated the localization of 'capacitative Ca2+
entry' (CCE). 16HBE14o- cells grown on permeable filters were mounted into an
Ussing chamber built for the simultaneous measurement of Fura-2 fluorescence and
electrical properties. Application of ATP from both sides induced a rapid [Ca2+]i
increase and subsequent sustained [Ca2+]i plateau due to transmembraneous Ca(2+)
influx. The use of different nucleotides revealed the following rank order or
potency which was very similar for addition from the apical or basolateral side:
UTP (EC50 ap: 4 microM, bl: 5 microM) > ATP (EC50 ap: 4 microM, bl: 10 microM) >
ADP (n = 4-7 from both sides). 2-MeS-ATP, AMP, adenosine and beta gamma-methylene
ATP were ineffective (n = 3 from both sides). The ATP- (ap and bl) induced Ca2+
influx was only abolished by removal of basolateral Ca2+. This was also true for
receptor-independent activation of Ca(2+)-influx by intracellular Ca(2+)-store
depletion with 2,5 Di-(tert-butyl)-1,4-benzohydroquinone (BHQ) (10 microM). Also
in polarized T84 cells the basolateral carbachol and BHQ activated Ca2+ plateau
was exclusively sensitive to removal of basolateral Ca2+. We propose that in all
polarized epithelial cells the CCE entry pathway is located in the basolateral
membrane. We furthermore suggest that Ca2+[i elevating agonists acting from the
apical side of the epithelium lead to the opening of a basolateral CCE pathway.
PMID- 10668564
TI - The characterization and quantification of antigen-induced Ca2+ oscillations in a
rat basophilic leukaemia cell line (RBL-2H3).
AB - Using the ratiometric Ca2+ indicator, indo-1, the antigen-induced increase in
intracellular Ca2+ concentration ([Ca2+]i) was measured in individual RBL-2H3
cells which had been passively sensitized with monoclonal antibody to the
dintrophenyl (DNP) haptenic group. Antigenic stimulation using DNP-human serum
albumin conjugate (DNP-HSA) induced concentration-dependent asynchronous Ca2+
oscillations, or irregular spikes. To achieve a quantitative comparison of the
effects of different concentrations of antigen on changes in Ca2+[i, the area
under the curve (AUC) of Ca2+ oscillations in each cell was calculated. The dose
response curve of the calculated AUC is consistent with the bell-shaped dose
response curve for antigen-induced mediator release, depolarization and 86Rb(+)
efflux. Ca2+ oscillations induced by antigenic stimulation were abolished by
removal of external Ca2+ and the subsequent reintroduction of external Ca2+
caused their resumption. To investigate the role of Ca2+ oscillations in the
secretory response, changes in [Ca2+]i induced by concanavalin A (Con-A), A23187,
thapsigargin and NECA were also monitored. Con-A mimicked the response induced by
antigen, whilst A23187 and thapsigargin induced a large transient non-oscillatory
response. NECA, an adenosine receptor agonist, induced only a small transient
rise in Ca2+[i without oscillatory behaviour. Since all these stimuli accept NECA
induced degranulation in these cells, it is suggested that, although Ca2+
oscillations are not essential for the initiation of secretion, they probably
underlie the in-vivo physiological response of mast cells and basophils to an
antigenic challenge. They also seem to enhance the efficacy of the Ca2+ signal.
PMID- 10668565
TI - Construction of a confocal microscope for real-time x-y and x-z imaging.
AB - We describe the construction of a simple 'real-time' laser-scanning confocal
microscope, and illustrate its use for rapid imaging of elementary intracellular
calcium signaling events. A resonant scanning galvanometer (8 kHz) allows x-y
frame acquisition rates of 15 or 30 Hz, and the use of mirrors to scan the laser
beam permits use of true, pin-hole confocal detection to provide diffraction
limited spatial resolution. Furthermore, use of a piezoelectric device to rapidly
focus the objective lens allows axial (x-z) images to be obtained from thick
specimens at similar frame rates. A computer with image acquisition and graphics
cards converts the output from the microscope to a standard video signal, which
can then be recorded on videotape and analyzed by regular image processing
systems. The system is largely made from commercially available components and
requires little custom construction of mechanical parts or electronic circuitry.
It costs only a small fraction of that of comparable commercial instruments, yet
offers greater versatility and similar or better performance.
PMID- 10668566
TI - Effects of hypochlorite-modified low-density and high-density lipoproteins on
intracellular Ca2+ and plasma membrane Ca(2+)-ATPase activity of human platelets.
AB - The presence of hypochlorite-modified lipoproteins in atherosclerotic lesions
suggests that HOCl, a naturally occurring oxidant formed by the myeloperoxidase
catalyzed reaction of H2O2 and Cl-, is a candidate for generation of modified
lipoproteins in vivo. We have previously demonstrated that Cu(2+)-oxidized LDL
inhibits platelet plasma membrane Ca(2+)-ATPase (PMCA) in isolated membranes and
causes an increase in cytosolic Ca2+ in resting whole platelets. However, Cu(2+)
oxidized LDL may not be identical in structure and function to the
physiologically modified lipoprotein. Since platelet function may be affected by
native and modified lipoproteins, the effect of HOCl-modified LDL and HDL3 on
platelet PMCA and on the free intracellular Ca2+ concentration ([Ca2+]i) of whole
platelets has been investigated. We demonstrate that in contrast to Cu(2+)
oxidized LDL, HOCl-modified LDL and HDL3 stimulate platelet PMCA activity in
isolated membranes and that this effect results in a decrease of [Ca2+]i in vivo.
Thus, HOCl-oxidation produces modified lipoproteins with the potential for
altering platelet function and with properties different from those of the Cu(2+)
oxidized counterparts.
PMID- 10668567
TI - Alterations in calcium-mediated signal transduction after traumatic injury of
cortical neurons.
AB - Calcium influx and elevation of intracellular free calcium ([Ca2+]i), with
subsequent activation of degradative enzymes, is hypothesized to cause cell
injury and death after traumatic brain injury. We examined the effects of mild-to
severe stretch-induced traumatic injury on [Ca2+]i dynamics in cortical neurons
cultured on silastic membranes. [Ca2+]i was rapidly elevated after injury,
however, the increase was transient with neuronal [Ca2+]i returning to basal
levels by 3 h after injury, except in the most severely injured cells. Despite a
return of [Ca2+]i to basal levels, there were persistent alterations in calcium
mediated signal transduction through 24 h after injury. [Ca2+]i elevation in
response to glutamate or NMDA was enhanced after injury. We also found novel
alterations in intracellular calcium store-mediated signaling. Neuronal calcium
stores failed to respond to a stimulus 15 min after injury and exhibited
potentiated responses to stimuli at 3 and 24 h post-injury. Thus, changes in
calcium-mediated cellular signaling may contribute to the pathology that is
observed after traumatic brain injury.
PMID- 10668568
TI - Bladder exstrophy: staged reconstruction.
AB - The modern staged approach to bladder exstrophy reconstruction has undergone
significant changes since it was first advocated by Jeffs and Cendron in the
1970s. Although varied surgical approaches have been tried in the bladder
exstrophy condition, the staged approach to bladder exstrophy repair has
withstood the test of time. Progress continues to be made in evaluating the
outcome of older types of staged reconstruction, with continuing modification and
improvements in the modern approach to staged reconstruction. This treatise will
update the reader on recent advances in the treatment of bladder and cloacal
exstrophy.
PMID- 10668569
TI - Insights into causes of sexual ambiguity.
AB - Our understanding of the causes of sexual ambiguity has progressed from the
determination of the hormonal etiologies to defining the genetic basis of
intersex disorders. The localization of specific genes involved in the process of
sexual differentiation has made it possible to determine the mutations and other
molecular events that result in sexual ambiguity. With this information, some
disorders can now be diagnosed before birth and possibly even treated in utero.
PMID- 10668570
TI - Changing concepts in hypospadias repair.
AB - After more than 100 years of innovation in hypospadias repair, new concepts
regarding penile curvature, the urethral plate, and the means for urethroplasty
are changing surgical practices. With the introduction of the tubularized incised
plate technique it is possible to simplify decision-making algorithms in
hypospadias surgery, while achieving good functional and cosmetic results.
PMID- 10668571
TI - Engineering tissues and organs.
AB - Genitourinary tissues can be engineered in-vitro and in-vivo for reconstruction
using selective cell transplantation in combination with acellular matrices. This
technology involves an interdisciplinary approach combining techniques of cell
biology and materials sciences towards the development of functional tissues or
organs. Tissues and organs in urology, such as the bladder, clitoris, corpus
cavermosum, kidney, testis, ureter and urethra have been created in the
laboratory, with varying degrees of functionality. Cells have also been recently
used in patients as bulking agents for the treatment of vesicoureteral reflux and
urinary incontinence. As the science of tissue engineering evolves, one can
expect a wider application of this technology to the armamentarium of urologic
surgery.
PMID- 10668572
TI - Current management of the infant with myelomeningocele.
AB - Infants with myelomeningocele continue to be a management dilemma for urologists.
This article discusses many of the current questions that surround the newborn
with myelomeningocele. What radiologic studies should be performed and when? How
does the clinician determine if bladder drainage is adequate or requires
altering? If a problem is identified what are the surgical options? When should
urodynamics be performed? Ultimately how one manages, follows and initiates
treatments in the newborn will have a significant effect on the long-term
morbidity seen in this population of children.
PMID- 10668573
TI - Andrology, sexual dysfunction, infertility.
PMID- 10668574
TI - Role of the urological surgeon in the age of intracytoplasmic sperm injection.
AB - In the last few years, it has been demonstrated that intracytoplasmic sperm
injection is an effective procedure for treating patients with severe male
infertility. Before this technique was available, the urological surgeon involved
in the reproduction field dealt mainly with reconstructive (vasoepididimostomy,
vasovasostomy) or endoscopic surgery of the seminal duct as well as
varicocelectomy. Nowadays, the urological surgeon continues to participate in the
field of reproductive surgery by applying methodologies which enable natural
conception, and has to be involved in all aspects of sperm retrieval techniques.
PMID- 10668575
TI - Oocyte insemination with spermatozoa precursors.
AB - Since the use of testicular spermatozoa in programs of assisted fertilization
proved very successful, attention was focussed on the use of spermatids also
carrying 23 chromosomes. Several difficulties became obvious; the first one
concerned the recognition of round spermatids. This is a problem which does not
concern elongating and elongated cells. The intra-cytoplasmic injection of
elongated spermatids resulted in several pregnancies but this is not so for the
round ones. Although, in the group of patients in whom only round spermatids are
found at the time of the attempt, is to be divided into two categories; patients
in whom previous research allowed to find spermatozoa, however few, and patients
who never produced spermatozoa at all. This last group is no longer an indication
for intracytoplasmic sperm injection procedure unless in the future new culture
media allow a maturation into elongated forms.
PMID- 10668576
TI - Pharmacological treatment of erectile dysfunction.
AB - There is growing evidence that the field of pharmacotherapy, particularly oral
drugs, will be dominant in the future management of sexual dysfunction. Basic
research has led to the understanding of the intracellular mechanisms that
control penile smooth muscle contractility and therefore erection, opening a vast
area for pharmacological intervention. Moreover, the importance of central
neurohormonal mechanisms has made these pathways the target for new centrally
acting drugs. Given these trends most patients suffering from erectile
dysfunction will respond to pharmacological agents in the not so distant future.
PMID- 10668577
TI - Pharmacological treatment of premature ejaculation.
AB - Ejaculatory dysfunction is the most common male sexual disorder and premature
ejaculation the most common presentation of ejaculatory dysfunction. Convincing
data are lacking from controlled clinical studies to support sustainable long
term efficacy of psychosexual counselling in the management of premature
ejaculation. The pharmacological treatment of premature ejaculation is now
receiving increased attention from both physicians with an interest in sexual
medicine and from the pharmaceutical industry.
PMID- 10668578
TI - Female sexual dysfunction: anatomy, physiology, evaluation and treatment options.
AB - It has been estimated that up to 76% of women, depending upon their age, have
complaints of sexual dysfunction, including decreased libido, vaginal dryness,
pain with intercourse, decreased genital sensation and difficulty or inability to
achieve orgasm. Female sexual dysfunction is a significant problem that affects
the quality of life of many women. This review addresses the etiologies and
incidence of female sexual complaints, as well as new findings in the evaluation
and treatment of female sexual dysfunction.
PMID- 10668579
TI - What's new in Peyronie's disease.
AB - Within the past year further scientific studies have been performed to find the
aetiology of Peyronie's disease. Advances in the conservative management of the
disease by extracorporeal shockwave therapy have been reported in many centres.
The operation of plaque excision and grafting, which has been performed for over
25 years, has now been replaced by the superior operation of plaque incision with
venous patch.
PMID- 10668580
TI - Bibliography. Current world literature. Pediatric urology.
PMID- 10668581
TI - Bibliography. Current world literature. Andrology, sexual dysfunction,
infertility.
PMID- 10668582
TI - Evaluation of six serological tests in diagnosis and postoperative control of
pulmonary hydatid disease patients.
AB - Latex agglutination (LA), passive hemagglutination (PHA), immunoelectrophoresis
(IEP) and specific IgE, IgM, IgG enzyme-linked immunosorbent assay (ELISA) tests
for diagnosis and postoperative follow-up of 79 patients with surgically
confirmed pulmonary hydatidosis were evaluated. Specific IgG ELISA was the most
sensitive test (83.5%) and the least sensitive tests were specific IgE ELISA
(44.3%) and IEP (50.6%). The specificity obtained for all the serologic test was
above 97% in all cases. The greatest number of false positives in all tests
(except IEP) occurred in patients with Taenia saginata and Taenia solium
cysticerci infestations and in patients with lymphoma and leukemia. Specific IgG
ELISA demonstrated the highest negative predictive value (93.8%). No
statistically significant differences (p > 0.050) were found in the sensitivity
of the tests when patients with only one cyst and patients with various cysts
were compared. Considering only the patients without relapse, the percentage of
seropositive patients increased in all tests at 1 and 3 months after surgery.
After that time the percentage of seropositive patients decreased. At 48 months
after surgery all patients without relapse became negative in IEP, specific IgE
ELISA, and specific IgM ELISA. The antibody titers in all seropositive patients
increased during the 3 months after surgery. From these 3 months onward, antibody
levels decreased in all serologic tests studied in the group of patients without
relapse. The patients who had relapses during the first year after surgery
presented persistently elevated antibody titers in all postoperative sera. The
antibody titers of the patients who relapsed between the third and fourth years
after surgery decreased progressively the third month after surgery, and
increased in the serum obtained at the moment of relapse diagnosis. Our results
show that persistence of elevated antibody titers in patients with pulmonary
hydatidosis in the year after surgery or titer increase after a progressive
decrease are indicative of relapse or reinfection.
PMID- 10668583
TI - Cefepime versus ceftazidime for the treatment of serious bacterial infections.
AB - The objective of this open, comparative and randomized clinical trial was to
compare the safety and efficacy of cefepime and ceftazidime in the treatment of
adults with severe infections. Fifty patients were included; 25 received cefepime
(1 g b.i.d.) and 25 ceftazidime (1 g t.i.d.). Demographic characteristics of the
groups were similar. The drugs were well tolerated and adverse reactions were
minor and comparable in both groups. Forty-four patients were evaluated (22 from
each group). There was a satisfactory clinical response in 86% and 77% in the
cefepime and ceftazidime groups, respectively. In patients with microbiologically
documented infection 83% (15/18) treated with cefepime and 64% (9/14) treated
with ceftazidime responded satisfactorily (no statistical significance). In
conclusion, the data confirms that cefepime is as safe and effective as
ceftazidime for the treatment of serious bacterial infections, with the advantage
of being administrated only twice daily.
PMID- 10668584
TI - Long-term non-progression of HIV-1 in a patient coinfected with HTLV-II.
AB - A 37-year-old man coinfected with HIV-1 and human T-lymphotropic virus type II
presumably through injection drug use had a high CD4+ count and low HIV viral
load without anti-retroviral therapy for over six years. As an HIV long-term non
progressor, his case supports the hypothesis that coinfection with HTLV-II does
not adversely affect the course of HIV disease.
PMID- 10668585
TI - Evaluation of the RapID Yeast Plus System for the identification of yeast.
AB - We evaluated the RapID Yeast Plus System using 117 fresh and frozen clinical
yeast isolates. The Uni-Yeast-Tek System was used to establish the correct
identification. The Vitek System was used as the arbiter for any discrepant
results, along with morphology. Of 117 isolates tested, the RapID Yeast Plus
System identified 96.6% correctly. The RapID Yeast Plus System is an accurate and
reliable alternative to other commonly used yeast identification systems.
PMID- 10668586
TI - In vitro evaluation of cefepime and other broad-spectrum beta-lactams for
isolates in Malaysia and Singapore medical centers. The Malaysia/Singapore
Antimicrobial Resistance Study Group.
AB - The degree of activity of several beta-lactam antimicrobial agents was assessed
in Malaysia (four medical centers) and Singapore (two medical centers) tested
against 570 clinical isolates. The organisms were tested locally by the Etest (AB
BIODISK, Solna, Sweden) method, validated by concurrent use of quality assurance
strains (94.1% accurate performance overall). Ten groups of bacteria were tested
against cefepime, cefpirome, ceftazidime, ceftriaxone, piperacillin/tazobactam,
oxacillin, and imipenem. Among the tested Escherichia coli and Klebsiella spp.,
the occurrence of extended spectrum beta-lactamase-producing phenotypes was 5.6
7.0% and 36.7-38.0%, respectively. These strains remained most susceptible (97.5
100.0%) to cefepime and imipenem. Ceftazidime-resistant Enterobacter spp. (21.4%
resistant), Citrobacter spp. (15.0%), indole-positive Proteus spp. (6.0%), and
Serratia spp. (9.7%) were not resistant to cefepime, and only one strain was
resistant to imipenem. Imipenem was generally most potent against non
fermentative Gram-negative bacilli such as Acinetobacter spp. and Pseudomonas
aeruginosa. All tested beta-lactams were active against the oxacillin-susceptible
staphylococci, except ceftazidime (MIC90, 12 micrograms/mL; 63.2-84.8%
susceptibility rates). Overall spectrums of activity (rank by % resistance)
favored imipenem (3.5%) > cefepime (7.7%) > cefpirome (8.9%) >
piperacillin/tazobactam (13.2%) > ceftriaxone (14.7%) > ceftazidime (16.9%). No
significant differences in resistance patterns were noted between monitored
nations, and these results indicate emerging, elevated rates of resistance versus
the studied broad-spectrum beta-lactams in Malaysia and Singapore. Results
provide benchmark data for future studies using quantitative methods to determine
antimicrobial resistance in these geographic areas.
PMID- 10668587
TI - In vitro evaluation of cefepime and other broad-spectrum beta-lactams against
bacteria from Indonesian medical centers. The Indonesia Antimicrobial Resistance
Study Group.
AB - The in vitro activity of cefepime and six other broad-spectrum beta-lactams
(cefpirome, ceftazidime, ceftriaxone, imipenem, piperacillin/tazobactam (4
micrograms/mL fixed concentration), and oxacillin was evaluated against 191
isolates of clinical bacteria from Indonesia. Susceptibility testing was
performed using Etest (AB BIODISK, Solna, Sweden) methodology. Isolates from 10
species groups were selected for analysis: Escherichia coli, Klebsiella spp.,
Enterobacter spp., indole-positive Proteae, Serratia spp., Acinetobacter spp.,
Pseudomonas aeruginosa, and oxacillin-susceptible staphylococci. The overall rank
order of spectrum of activity was (% resistant): imipenem (2.2%) > cefepime
(7.3%) > piperacillin/tazobactam > cefpirome > ceftazidime > ceftriaxone (16.2%).
The "fourth-generation" cephalosporins, cefepime and cefpirome, displayed greater
activity compared with the "third-generation" cephalosporins, ceftazidime, and
ceftriaxone, against the 60 E. coli and Klebsiella spp. (30 each) isolates.
Phenotypic extended spectrum beta-lactamase occurrence rates among the E. coli
and Klebsiella spp. were 23.3 and 33.3%, respectively. Imipenem, cefepime, and
cefpirome inhibited 95.7% of the 46 isolates of inducible Amp C cephalosporinase
producing Enterobacteriaceae. The majority of the resistance observed to imipenem
and cefepime among tested Indoneisian strains was attributable to the
nonfermentative Gram-negative bacilli, P. aeruginosa and Acinetobacter spp. These
results indicate the presence of beta-lactam resistance in Indonesia and the need
for continued antimicrobial surveillance in this nation and region of the world,
preferably using accurate quantitative methods.
PMID- 10668588
TI - In vitro evaluation of broad-spectrum beta-lactams in the philippines medical
centers: role of fourth-generation cephalosporins. The Philippines Antimicrobial
Resistance Study Group.
AB - Cefepime is a potent broad-spectrum "fourth-generation" cephalosporin. The in
vitro activity of cefepime was compared to that of cefpirome, ceftazidime,
ceftriaxone, imipenem, and piperacillin/tazobactam in a multilaboratory (nine
medical centers) Philippine surveillance project from March through October 1998.
A total of 626 Gram-positive and Gram-negative organisms (10 species groups) were
tested by the Etest method (AB BIODISK, Solna, Sweden) with results validated by
current quality control strain analysis. The overall rank order of usable
spectrum of activity was imipenem (4.2% resistance), cefepime (4.5%), cefpirome
(5.0%), piperacillin/tazobactam (5.8%) > ceftriaxone (11.2%) > ceftazidime
(15.3%), and results did not differ significantly between medical centers.
Ceftazidime-resistant Escherichia coli and Klebsiella spp. occurred at rates of
13.3% and 31.1%, respectively, indicating extended-spectrum beta-lactamase (ESBL)
activity. Imipenem (100% susceptible), cefepime, and cefpirome (both > or = 97.8%
susceptible) were active in vitro against these ESBL phenotypes. Organisms with
ceftazidime and/or ceftriaxone-resistant profiles consistent for hyper-production
of Amp C cephalosporinases were detected at high rates among the Citrobacter spp.
(29.2%) and Enterobacter spp. (45.8%); however, imipenem (100.0% susceptible) and
cefepime (98.9%) remained active. Cefepime and imipenem (both 87.5% susceptible)
were the most active agents tested against Acinetobacter spp. whereas
piperacillin/tazobactam was most effective against P. aeruginosa (80.0%
susceptible). Most tested beta-lactams (except ceftazidime) were active versus
oxacillin-susceptible staphylococci. These data should be used as a guide for
treatment selection with beta-lactam compounds in the Philippines and to serve as
a resistance benchmark in comparisons with future studies in this nation.
PMID- 10668589
TI - In vitro evaluation of cefepime and other broad-spectrum beta-lactams in Taiwan
medical centers. The Taiwan Antimicrobial Resistance Study Group.
AB - The rates of resistance to commonly used antimicrobial agents have been
documented to be at alarmingly high levels in Taiwan for both Gram-positive and
Gram-negative species. This study was conducted to assess the current resistance
patterns in six medical centers strictly controlled using a common MIC
methodology and quality assurance measures. Cefepime, a new clinically introduced
broad-spectrum "fourth-generation" cephalosporin, was compared to other members
in this class including ceftazidime, cefpirome, ceftriaxone,
piperacillin/tazobactam, and imipenem. These antimicrobials were tested against
ten species groups of common clinical isolates of Enterobacteriaceae, non-enteric
Gram-negative bacilli, and oxacillin-susceptible Staphylococcus spp. The results
confirmed that extended spectrum beta-lactamase (ESBL) production in Klebsiella
spp. (21.7%) and Escherichia coli (16.7%) was common in all medical centers
surveyed. Cefepime was more active against these two species as well as against
Amp C producing species, indole-positive Proteae, and Acinetobacter species. The
activity of cefepime was comparable although slightly less than that of
ceftazidime against Serratia spp. and Pseudomonas aeruginosa strains. All or
nearly all staphylococci isolates were susceptible to the beta-lactam
antimicrobial agents, except for ceftazidime. Overall, these antimicrobial agents
had descending spectrums of activity as follows: imipenem > cefepime > cefpirome
> piperacillin/tazobactam > ceftazidime > ceftriaxone for the 550 isolates
tested. Cefepime seems to be an important broad-spectrum beta-lactam that can be
used with confidence against many important pathogens in Taiwan, including those
harboring resistance mechanisms. A continued surveillance program seems prudent
for this geographic area.
PMID- 10668590
TI - In vitro evaluation of cefepime and other broad-spectrum beta-lactams in 22
medical centers in Japan: a phase II trial comparing two annual organism samples.
The Japan Antimicrobial Resistance Study Group.
AB - An antimicrobial resistance surveillance study in Japan is presented representing
the second year (Phase II) results from 22 medical centers. Each participant
laboratory tested (Etest, AB BIODISK, Solna, Sweden) 100 organisms, 10 strains
each from 10 species groups including Escherichia coli, Klebsiella spp.,
Enterobacter spp., Citrobacter spp., indole-positive Proteae, Serratia spp.,
Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible
Staphylococcus aureus and coagulase-negative staphylococci. Generally only modest
variations in the activity of the studied broad-spectrum beta-lactams was
observed compared to the study a year before. Specifically, extended spectrum
beta-lactamase (ESBL) rates in E. coli increased (2.9 to 8.1%), but the ESBL rate
in Klebsiella spp. fell (8.6 to 5.0%). Overall the resistance to the beta-lactams
varied from a 4.7% decrease (ceftazidime as a consequence of a modified
staphylococcal breakpoint criteria) to a 1.0% increase (cefepime, not
significant). The rank order of spectrums in 1998 only changed for cefoperazone
sulbactam (6.1% resistance) that was active against more strains than cefpirome
(6.8% resistance). The overall spectrum rank order for the 1998 Japan sample (%
resistance) was: cefepime (3.2%) > imipenem (4.1%) > cefoperazone-sulbactam
(6.1%) > cefpirome (6.8%) > ceftazidime (8.4%) > piperacillin (19.9%). As with a
similar study in 1997, imipenem-resistant isolates of P. aeruginosa and Serratia
spp. were discovered with metalloenzymes, usually found in the same medical
centers. These results demonstrate the continued in vitro activity and potential
sustained clinical efficacy of several broad-spectrum beta-lactams in Japan.
Rapid emergence of new or novel resistance were not wide spread using a precise
quantitative MIC system. Continued surveillance in this nation would be prudent
to document the activity of this clinically valuable class of safe, antimicrobial
agents.
PMID- 10668591
TI - In vitro evaluation of broad-spectrum beta-lactams tested in medical centers in
Korea: role of fourth-generation cephalosporins. The Korean Antimicrobial
Resistance Study Group.
AB - Levels of resistance to the "third-generation" cephalosporins among isolates of
clinical bacteria in Korea have been increasing at a rapid rate. This study
evaluated the activity of cefepime, a "fourth-generation" cephalosporin, and six
other broad-spectrum beta-lactam antimicrobials (cefpirome, ceftazidime,
ceftriaxone, imipenem, piperacillin/tazobactam 4 micrograms/mL fixed
concentration[, oxacillin) against 404 isolates of clinical bacteria from Korea.
Susceptibility profiles of each isolate were established using the Etest (AB
BIODISK, Solna, Sweden) method of susceptibility testing. Only the carbapenem
imipenem was > 90% effective in inhibiting each of the species tested
(Escherichia coli, Klebsiella, spp., Citrobacter spp., Enterobacter spp., indole
positive Proteae, Serratia spp., Acinetobacter spp., Pseudomonas aeruginosa, and
oxacillin-susceptible staphylococci). Imipenem was followed by cefepime >
cefpirome > piperacillin/tazobactam > ceftazidime > ceftriaxone in overall rank
order of usable spectrum against the isolates tested. Extended spectrum beta
lactamase producing phenotypes were much more prevalent among the Klebsiella spp.
(48.8%) than the E. coli (5.0%) isolates. Cefepime was much more active than
cefpirome, 95.1% susceptible as compared with 70.7% susceptible, against the 41
isolates of Klebsiella spp. The results of this study corroborates findings from
earlier studies with levels of resistance to the broad-spectrum beta-lactams in
Korea continuing to rise indicating the need for intervention strategies.
PMID- 10668592
TI - In vitro evaluation of cefepime and other broad-spectrum beta-lactams in eight
medical centers in Thailand. The Thailand Antimicrobial Resistance Study Group.
AB - The introduction of cephalosporins has had an important impact on the resistance
rates to several clinically utilized beta-lactam antimicrobial agents. Most
Thailand medical centers have not documented the levels of emerging resistant
pathogens causing invasive infections. This study shows using reference-quality
MIC techniques (Etest, AB BIODISK, Solna, Sweden), that carbapenem), "fourth
generation" cephalosporins (cefepime and cefpirome), and piperacillin/tazobactam
were the most active agents tested against Gram-negative bacilli (Escherichia
coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., Serratia spp., indole
positive Proteae, Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin
susceptible Staphylococcus spp. when compared to "third-generation"
cephalosporins (ceftazidime and ceftriaxone). The rank order of activity for all
species was imipenem (2.9% resistant) > cefepime (7.7%) > piperacillin/tazobactam
(11.1%) > cefpirome (13.4%) > ceftriaxone (21.1%) > ceftazidime (29.9%). The
incidence of extended spectrum beta-lactamase production among E. coli (15.7%)
and K. pneumoniae (45.6%) was significant. Cefepime and imipenem were active
against the majority of these isolates. The activity of cefepime was also shown
to be very good against, 1) organisms capable of producing AmpC enzymes, 2)
staphylococci species that were susceptible to oxacillin, and 3) many strains of
nonfermentative Gram-negative bacilli. The prevalence of antimicrobial resistance
in Thailand seems to be quite high among certain commonly encountered pathogens,
and imipenem and cefepime have activity (susceptible and intermediate potency)
against > 90% of these organisms.
PMID- 10668593
TI - Summation: beta-lactam resistance surveillance in the Asia-Western Pacific
region.
PMID- 10668594
TI - [First clinical episode of bipolar disorders: a study within a population of
bipolar I and bipolar II French patients].
AB - Clinical symptoms of bipolar disorders onset act as a prognostic risk-factor.
Discrepancies of data are related with geographical or cultural conditions.
Within a patient population of bipolar (ICD 10) in and out patients of a
psychiatric department, manic or hypomanic disorders initiate the space disease
in 33% of the cases theses features are similar within the western psychiatric
population. In a maghrebian population this proportion reaches 50%. A percentage
of 65% of bipolar 1 patients was found within our sample. Sex ratio is 1 for
bipolar 1, when, for bipolar 2 disorders sex-ratio was superior to 1, in favor of
females. Mean age of the first episode of the disease was younger for patients
with a familial history of the disease.
PMID- 10668595
TI - [A study of endogenous evoked potentials (P300 and CNV) in retired patients].
AB - Endogenous evoked potentials of two types (CNV and P300 complexes) as well as
their respective reaction times were recorded in 29 elderly, active subjects (15
men and 14 women) between 60 and 84 years of age. Our subjects also passed
anxiety, depression and cognitive scales. The different results were then
analyzed in relation with each other and in relation with age and sex. No age
related differences were found in the principal elements measured in the P300
complex, but several elements of the CNV complex were clearly shown to be age
sensitive. Sex-related differences were found in the N2 and P3a potentials. CNV
morphology (Tecce type A) and cognitive scores were found to be related to
Spielberger's anxiety-trait sub-scale. Several results also highlighted the
heterogeneity of this age group. The need for complementary studies in this age
group is then discussed with the hope that neurophysiology can become a useful
tool in psychogeriatrics.
PMID- 10668596
TI - [Stressful life events: models and methodology. Critical considerations].
AB - Many recent studies tend to show that life events play an important role in
provoking, solving or maintaining psychic troubles. The proposed approach is
interesting as far as it brings back into the model many psychosocial factors
implied in psychic or somatic problems. We wanted to review the interest of the
main theoretical and methodological approaches in that field and also to stress
their drawbacks. One many improve the life events approach by taking into account
the difficulties associated with that type of research and by avoiding an
oversimplification of the relationship between life events and health. The links
are complex, the impact of life events results from depressive mechanisms,
adjustment strategies, social support, age, sex, personality, history, past
experience and sociocultural representations. This complex picture compels
clinicians to take a complementarist attitude when all the theories are
scrutinized in order to understand the links between life events and health. From
a methodological point of view, the most relevant approach seems to be the
combination of standardized scales and semi-structured interviews allowing a
contextual approach of events.
PMID- 10668597
TI - [Heroin abuse, autobiographical memory and depression].
AB - The early psychiatric interviews with opiate addicts are characterized by three
features: 1) the patient has a very factual and objective conversation, 2) the
evaluation of the autobiographical memory is very difficult, 3) there is a high
prevalence of affective disorders responsible for an impairment in cognitive
functions. Therefore we have two aims: First, to compare episodic and semantic
autobiographical memory in opiate addicts and healthy controls. Autobiographical
memory is the knowledge a person has about oneself and his past. Personal
semantic memory is the knowledge of the biographical facts, general knowledge and
beliefs about oneself. Autobiographical episodic memory concerns recollections of
personal events clearly delineated in time and space. Second, to estimate the
impact of depression on the ability to produce autobiographical recollection in a
population of opiatre addicts. Participants were consecutive attenders of a
methadone outpatient clinic who are multiple drug dependent patients consuming
mainly heroine. The first investigation took place in entry and after two months.
We have recruited 21 patients with a mean duration of intoxication of 11 years.
Ten of these patients have been investigated again after 2 months and 8 of them
have been included in a methadone maintenance program. The patients'investigation
comprised two parts: first, the evaluation of autobiographical memory (only
assessed at entry of the study) with an autobiographical fluency test and the
semi-structured autobiographical memory interview of Kopelman; second, the
psychiatric assessment included self-rating questionnaires and observer-rating
questionnaires. Opiate addicts showed a decrease in episodic autobiographical
memory but an increase in semantic affective memory and objective modalization.
In the fluency test, there was no difference in the number of evoked items
between opiate addicts and healthy controls. The educational level influences
several results. The possible explanations of these results are the action of the
toxic products and a particular psychic functioning. The lack of correlation
between autobiographical memory and affective disorder suggests the implication
of the drugs in the emergence of memory deficits. The improvement of depressive
symptomatology after two months occurring without psychotropic drugs suggests the
transient feature of depression and emphasises on non-pharmacological aspects of
treatment.
PMID- 10668598
TI - [The study of the impact of the consensus conference "Strategies for long-term
therapy of patients with schizophrenia"].
AB - The case management, treatment and psychosocial rehabilitation of schizophrenic
patients is an important part of the activity of the psychiatric sector and takes
up many human, scientific, organizational and financial resources. The best way
to reach satisfactory results for the individual patient is still uncertain and
current practice in France shows noticeable variations that have been rarely
investigated in terms of outcome. A consensus conference (CC) on "Strategies for
long-term therapy of patients with schizophrenia" was therefore held in Paris in
1994 to produce accurate guidelines designed to help both clinicians and patients
and to improve practice. It was organized by the French Federation of Psychiatry,
the National Union of Friends and Relatives of Mental Patients, and the National
Agency for the Development of Health Evaluation. The conclusions of the CC were
mailed, in the form of a booklet, to members of these associations (psychiatrists
and relatives) and were reported in the medical and general press. METHODS: The
impact of the CC was judged by (a) the psychiatrists'awareness of the existence
of the CC, (b) their knowledge of its conclusions, and (c) changes in practice.
The following were analyzed: press coverage; requests for the booklet; the
results of a survey of a representative sample of 396 psychiatrists two years
after the CC; prescription changes in the public sector in a cohort of 2,407
schizophrenic patients under treatment at the time of the CC; prescriptions to
psychotic patients by a representative sample of psychiatrists in private
practice. RESULTS: Awareness: Articles on the CC were published in 27 journals
and newspapers, 30,000 booklets were distributed and 8,348 were mailed in
response to 1,121 spontaneous requests; 78% of the psychiatrists interviewed said
they were aware of the existence of the CC and 70% said they were aware of the
conclusions. Knowledge: The psychiatrists' declared practice conformed with CC
conclusions 41%-85% of the time depending on the recommendation. No difference in
practice was noted between the psychiatrists who said they knew of the
recommendations and those who said they did not. Changes in practice: A
significant but small improvement in prescription habits was noted for a
principal recommendation ("just one neuroleptic is enough"). One-neuroleptic
prescriptions increased from 51.1% the year before the CC to 56.4% two years
after the CC. The increase mainly concerned the most recently treated patients.
However, during the same time-span, prescriptions of anti-cholinergics plus
neuroleptics rose from 48.2% to 54.3%. CONCLUSION: It is difficult to attribute
changes in practice to a CC. However, the impact of the CC seemed real even if
inconstant and not great enough. Clearly, to enhance impact an action plan is
needed. It should include corrective measures and focus on additional
dissemination efforts, teaching and training programs, and updating of guidelines
if necessary.
PMID- 10668599
TI - [Addiction and personality traits: sensation seeking, anhedonia, impulsivity].
AB - This study presents the evaluation of three dimensional traits of personality
(Sensation Seeking, Anhedonia, Impulsivity) among 65 patients admitted in a
psychiatric ward, with or without addictive behaviors. Our objective is to
establish that these personality traits are commun to all addictive behaviors and
to test the hypothesis that high scores on the three scales are linked to a
greater probability of presenting with addictive behaviors. The two most frequent
types of addiction were alcoholism and drug abuse. The subjects presenting with
one or several addictive behaviors had higher average scores on the three scales.
Our results printed in the same direction for the subjects having shown an
addictive behavior in their past history. The risk to present with an addictive
behavior increased with the total scores of these self-report questionnaires.
There was a significant relationship between 3 sub-dimensions on the Sensation
Seeking Scale and addictive behavior. Each time sub-scores of boredom
susceptibility, disinhibition and thrill and adventure rise by one, the risk to
present with an addictive behavior is multiplied by 1.4 for the first two and by
1.3 for the third one. Subjects with high scores on the anhedonia and impulsivity
scales respectively show a risk multiplied by 1.6 and 3.3 of developing an
addictive behavior. These results of this transverse study confirm the link
between addiction behavior and these three personality traits.
PMID- 10668600
TI - [Selective attention and schizophrenia before the administration of
neuroleptics].
AB - In recent years, the presence of attention deficits has been recognized as a key
feature of schizophrenia. Past studies reveal that selective attention, or the
ability to select relevant information while ignoring simultaneously irrelevant
information, is disturbed in schizophrenic patients. According to Treisman
feature-integration theory of selective attention, visual search for conjunctive
targets (e.g., shape and color) requires controlled processes, that necessitate
attention and operate in a serial manner. Reaction times (RTs) are therefore
function of the number of stimuli in the display. When subjects are asked to
detect the presence or absence of a target in an array of a variable number of
stimuli, different performance patterns are expected for positive (present
target) and negative trials (absent target). For positive trials, a self
terminating search is triggered, that is, the search is ended when the target is
encountered. For negative trials, an exhaustive search strategy is displayed,
where each stimulus is examined before the search can end; the RT slope pattern
is thus double that of the positive trials. To assess the integrity of these
processes, thirteen drug naive schizophrenic patients were compared to twenty
normal control subjects. Neuroleptic naive patients were chosen as subjects to
avoid the potential influence of medication and chronicity-related factors on
performance. The subjects had to specify as fast as possible the presence or
absence of the target in an array of a variable number of stimuli presented in a
circular display, and comprising or not the target. Results showed that the
patients can use self-terminating search strategies as well as normal control
subjects. However, their ability to trigger exhaustive search strategies is
impaired. Not only were patients slower than controls, but their pattern of RT
results was different. These results argue in favor of an early impairment in
selective attention capacities in schizophrenia, which appears before the
introduction of neuroleptics. The attention performance was also shown to present
some association to clinical symptoms.
PMID- 10668601
TI - [Associations and interactions: tricyclic antidepressants and selective serotonin
reuptake inhibitors].
AB - Following the commercialization of the SSRIs clinicians described cases of drug
interactions with tricyclic antidepressants among their patients. When combining
tricyclic antidepressants and SSRIs clinical side effects and elevated plasma
levels of tricyclics appeared. A better knowledge of the cytochrome P450 system
allows to understand the mechanism of such drug interactions. The cytochrome P450
is composed of a group of isoenzymes, which are classified, into families and
subfamilies on the basis of amino acid sequence homology. A number of the
cytochrome genes have a genetic polymorphism responsible for poor and extensive
metabolisers. The clinical importance of genetic polymorphism is highly dependent
upon the therapeutic index. Thus, poor metabolisers, will experience side effects
and rapid metabolisers prone to therapeutic failure. Concerning pharmacological
issues SSRIs have a great affinity for at least one of the isoenzymes which
accounts for drug interactions. Due to the inhibitory potential of the SSRIs drug
interactions occur with tricyclics that have a narrow therapeutic index. The
SSRIs do not exert the same inhibitory effect on the various isoenzymes. The
inhibitory activity for an isoenzyme depends on the molecule of the SSRIs. In
clinical practice, the associations between tricyclics and SSRIs should be
practiced with caution. It is recommended to decrease the tricyclic dose before
administering the SSRI, to start with low doses of the SSRI and to take into
account the therapeutic index. Although the coadministration of tricyclics and
SSRIs can produce adverse reactions it has also two main interests in clinical
practice. First, the drug combination enhances clinical response to treatment.
Secondly, it converts non-responders of pharmacological treatment to responders.
Used with caution the association of tricyclics and SSRIs is well tolerated.
However, it should be kept in mind that a single drug therapy should be tried
first. These data show the complexity of drug interactions.
PMID- 10668602
TI - [Case report: electroconvulsive therapy during pregnancy].
AB - The treatment for psychiatric disorders in pregnancy remains difficult to
implement. We report the case of a 28-year-old woman, 20 weeks pregnant when
admitted in our psychiatric department. She presented severe depressive disorder,
associated with agitation, and psychotic symptoms as delusion and hallucinations
occurred. The patient had a history of recurrent mood disorders dating back to
eight years before the current admission, including some atypical episodes
(psychotic symptoms only), and alternating with free periods without any trouble.
A non-specific personality disorder is also probably present. We first used
antidepressant (clomipramine) and sedative phenothiazine drugs. Because of the
lack of therapeutic efficacy, three weeks later we tried another pharmacologic
prescription, that also failed to improve the patient' status. It was hence
decided to proceed with electroconvulsive therapy. We describe here the
management of the courses, especially the careful monitoring and the anesthetic
features we employed, among which endotracheal intubation, oxygen supply, real
time ultrasonography, and recording uterine contractions and fetal heart rate.
All theses measures were applied within a surgical-obstetrical theatre. Nine
bifrontal courses were performed in five weeks. They rapidly and completely
improved the psychiatric symptoms. No sign of fetal neither maternal bad
tolerance occurred. While the patient had been authorized to leave hospital, in
34th weeks amenorrhea a routine ultrasonographic examination discovered worrying
fetal ascites signs. After the emergency caesarean delivery, the male newborn
child undergone immediately surgical treatment for vascular meconium peritonitis,
but died nine days later with metabolic post-surgical troubles. This fatal
outcome after electroconvulsive therapy leads us to discuss its possible
involvement, and in a more general way the safety and place of this treatment in
pregnancy psychiatric disorders. They remain critical situations in which
therapeutic methods should be rapidly decided. The authors wish others
practitioners to bring new case-reports in order to assess the ECT safety-use
during pregnancy.
PMID- 10668603
TI - [Neuropsychiatric disorders induced by MDMA ("Ecstasy")].
AB - If neurotoxicity of MDMA (ecstasy) is now well documented in animals, it is not
the same in humans. MDMA intoxication puts the problem of its possible link with
the serotonin syndrome and the neuroleptic malignant syndrome. Neuropathological
consequences following MDMA intake have been reported, including hemorrhaging and
cerebral infarction, cerebral venous sinus thrombosis, and acute inflammatory CNS
disease. However, the physiopathology of these complications remains unclear. In
the same way, there have been various reports that have attributed MDMA to
precipitating the onset of a wide range of psychiatric disorders including sleep
disorders, cognitive disorders, panic attacks, depression, flashbacks, psychosis
and severe paranoia. Findings suggest that these psychiatric manifestations might
be consequences of MDMA induced brain serotonin neurotoxic lesions. All these
data are examined from a critical review of the literature.
PMID- 10668604
TI - [Survey on the announcement of schizophrenia diagnosis in France].
AB - Medical information for the general public, patients and their families is a
current Public Health priority. What information can be given to a patient
suffering from schizophrenia, whose understanding and judgement capacities are
supposedly affected by this mental disease? In the United States, 70% of
psychiatrists inform patients of schizophrenia and diagnosis of schizophreniform
disorder, while in Japan less than 30% do this. The lack of information given to
the general public on the disease may contribute to reinforcing the difficulty in
announcing the diagnosis. Indeed, the beliefs and attitudes of the patient,
his/her family, the general population and health carers concerning the disease
do not match up. However, the first two years seem to be a main issue for the
subsequent evolution of the disease. No specific data on the attitude of French
clinicians with respect to the announcement of the diagnosis is available. In the
current legal context and in view of the advances in treatment, we have carried
out a survey among French psychiatrists. It is an auto-questionnaire, transversal
epidemiological, descriptive and analytical. The questionnaire was sent to a
population of 12,958 psychiatrists. It comprised 48 questions: 7 referred to the
socio-demographic and professional characteristics of the subjects, 22 to the
attitude with respect to the announcement of the diagnosis to the patients, and
the last 18 concerned the attitude with respect to the announcement of the
diagnosis to the families. 1,691 questionnaires were returned by free post and
analysed. The socio-demographic characteristics of the sample are close to those
of French psychiatrists as a whole. The number of patients suffering from
schizophrenia in the active files of the psychiatrists is 24% (+/- 21.4) on the
entire sample. Approximately a third (37.8%) of psychiatrists deem it necessary
to announce the schizophrenia diagnosis and approximately two thirds (69.5%)
declare that they sometimes announce it. Among the patients suffering from
schizophrenia in the active files of the psychiatrists who responded,
approximately a third (34%) were informed of their diagnosis. The main reasons
for not announcing the diagnosis are firstly the "reticence to give a diagnosis
label" and secondly "the functional incapacity of the patient to understand the
concept". The alternative diagnosis term most commonly used is "psychosis"
(46.5%). However, 48.1% of practitioners state that the announcement of a
specific diagnosis allows a better therapeutic combination. Depending on the
proportion of patients suffering from schizophrenia in their active file
presented in two categories (< 10% and > 10%), psychiatrists significantly most
frequently announce the specific diagnosis (17.3% vs 25.3%, p < 10(-3). A
statistically significant proportion of younger psychiatrists (44.4 vs 46.3, p <
10(-3) with fewer years of practice (14.1 vs 15.8), more often believe that it is
necessary to announce the diagnosis. The rate of response (13.5%) for this type
of survey seems high, which could indicate a high interest among psychiatrists
with respect to this question. Our data showed the existence of a correlation
between age, number of years in practice, type of practice and the proportion of
patients suffering from schizophrenia in the active file on the one hand and the
attitude of the psychiatrists with respect to the announcement of the diagnosis
on the other hand. It is possible that the multi-disciplinary team work of public
practice psychiatrists and the fact that they are more often confronted with
schizophrenic disease facilitate the announcement of this diagnosis. In the
survey population, the inability to give a diagnosis may be related to the
questions of the practitioners about the capacity of the subjects to understand,
the lack of precision of this diagnosis, the fear of disheartening the patients
and the absence of curative treatment. The risk of suicide does not seem to be
one
PMID- 10668605
TI - [Diagnostic criteria for fronto-temporal lobe degeneration].
AB - Circumscribed atrophy of the frontal and temporal lobes (frontotemporal lobar
degeneration) accounts for about one fifth of cases of primary degenerative
dementia occurring before the age of 65. It produces three prototypical clinical
syndromes. The most common is frontotemporal dementia, characterized by
personality change and profound alteration in social conduct and associated with
bilateral atrophy of the frontal and anterior temporal lobes. Progressive non
fluent aphasia is characterized by difficulty in verbal expression, anomia and
phonemic errors in the presence of relative preservation of comprehension and
associated with atrophy predominantly of the left hemisphere. In semantic
dementia there is fluent speech with semantic errors and severely impaired
comprehension and naming, together with a visual associative agnosia, resulting
from bilateral atrophy of the inferior and middle temporal gyri. The clinical
syndromes occur with either of two main histological types: prominent
microvacuolar change, without specific histological features (frontal lobe
degeneration-type), severe astrocytic gliosis with or without ballooned cells and
inclusion bodies (Pick-type). To improve clinical recognition and advance
understanding of this relatively common form of cerebral degeneration, members of
an international workshop on Frontotemporal Lobar Degeneration developed
consensus criteria, building upon earlier published clinical diagnostic
guidelines for frontotemporal dementia. The consensus criteria reported here
specify core and supportive features for each of the prototypical clinical
syndromes: frontotemporal dementia, progressive aphasia and semantic dementia, as
well as providing broad inclusion and exclusion criteria for the generic entity
of frontotemporal lobar degeneration.
PMID- 10668606
TI - [Construction and validation of visual analogue scale for risk assessment].
AB - This paper describes the factor structure and validity of a visual analogue scale
designed to rate risk proneness: EVAR (EVAluation of Risk). Risk behaviors and
sensation seeking are related, therefore we correlated EVAR (24 100 mm items)
with Zuckerman Sensation Seeking Scale (SSS) (40 conventional items) in a
population of 199 volunteers. Subjects had an age range of 18-68 years (mean age
of 31), and 49 were females. Factor analysis using a principal component solution
and an orthogonal rotation of the factor matrix were computed. Five factors were
selected, accounting for 46 per cent of the total variation: F1 "self control",
F2 "danger seeking", F3 "energy", F4 "impulsiveness", F5 "invincibility". F1, F2
and F3 from EVAR were correlated with SSS factors "general", "danger seeking",
"experience seeking" and "boredom susceptibility". F4 was correlated with
"general", "boredom susceptibility" and "disinhibition" whereas F5 was not
correlated with any of SSS factors. This visual analogue scale is likely to
reveal change in subjects, regarding risk proneness, when submitted to various
stressors (sleep deprivation, fatigue...).
PMID- 10668607
TI - [Methodological proposals for the evaluation of the mood stabilizing effect of an
antipsychotic drug].
AB - Antipsychotic drugs are widely used in the long term treatment of bipolar and
schizoaffective disorders. Nevertheless clinical trials devoted to the specific
assessment of the mood stabilizing effect of these drugs are quite rare. Among
recent studies only those by S. McElroy on olanzapine and by R. Bowden on
divalproex have included mood symptoms as inclusion and outcome criteria. This
paper reviews the different methodological proposals both in term of protocol
designs (retrospective, naturalistic, longitudinal and prospective studies) and
of efficacy criteria (time to relapse, reasons for drop outs, treatment switch,
functional status).
PMID- 10668608
TI - [Orbitofrontal syndrome in psychiatry].
AB - Orbitofrontal syndrome is a variant of frontal lobe syndrome in which behavioural
disturbances are prevailing. It results from bilateral lesions of the
orbitofrontal cortex and the medial face of frontal lobe. Patients present
disorganized hyperactivity. They are distractable, impulsive, euphoric and unable
to abide by social rules. They often have instinctive disinhibition
(hypersexuality, hyperphagia and urinary behaviour disorders). In spite of severe
behavioural disturbances cognitive functions are often intact so that
orbitofrontal syndrome may be confounded with two psychiatric disorders: mania
(or hypomania) and antisocial personality disorder. In this article we present a
case report of orbitofrontal syndrome which was initially misdiagnosed as mania.
Clinical features and possible modes of presentation of this syndrome are
discussed. It is suggested that serotonin reuptake inhibitors may be of some use
in this disorder.
PMID- 10668609
TI - [The concept of supersensitivity psychosis. The particular case of clozapine].
AB - Neuroleptics are the main biological treatment for psychotic patients. The brutal
withdrawal of a neuroleptic treatment may induce an important aggravation of the
psychotic symptoms. A few of those relapses may occur very early after the
interruption of treatment; they are often associated with a modification of the
symptoms and an unfavorable evolution in the course of the illness. Using those
clinical observations a few authors have developed the concept of
supersensitivity psychosis to explain those kinds of relapses and to formulate
hypothesis about tolerance and resistance to neuroleptics. They focus on the
possible correlation between supersensitivity psychosis and tardive dyskinesia.
We report three cases of a dramatic aggravation of the psychotic symptomatology
following the withdrawal of clozapine in three schizophrenic patients resistant
to classical neuroleptic treatment. According to the clinical data and to the
physiopathological hypothesis, the concept of supersensitivity psychosis can have
implications in the therapeutic management of resistant schizophrenic patients.
PMID- 10668610
TI - [Predictive factors for patient maintenance on buprenorphine high dosage
treatment: a naturalistic study in primary care].
AB - High dosage buprenorphine is actually the principal treatment for substitution
medication in France. Clinical trials have demonstrated the clinical efficacy of
HD buprenorphine for narcotic addiction, but few data are published concerning
the prognostic factors of treatment response in daily practice. A naturalistic
study was performed in 1998. 200 generalist practitioners were recruited and 956
patients were included. Sociodemographic, medical and addiction history were
collected. A quantitative socio-comportemental and medical indicator (SCMI) was
performed. The psychometric properties of the SCMI were analyzed. Simple and
multivariate analysis was performed. Patients with good social adjustment and
past withdrawal are good responders to HD buprenorphine. Not treated psychiatric
pathology was a prognostic factor associated with a relatively poor response to
HD buprenorphine. A long duration of treatment (one year) and a clear therapeutic
program were associated with good response.
PMID- 10668611
TI - [Abuse of and dependence on zolpidem: a report of seven cases].
AB - Zolpidem is an hypnotic drug that belongs to the imidazopyridine family. Its
chemical structure is different from that of benzodiazepines though both type of
drugs bind specifically to the same site of the GABA-A macromolecular complex:
the omega 1 benzodiazepine receptor. This mechanism of action could be
responsible for the predominantly hypnotic properties of zolpidem and its reduced
liability to induce dependence in comparison with benzodiazepines. Yet, several
cases of zolpidem abuse and dependence have been published recently. We report
seven cases, from which three are detailed, of zolpidem abuse and/or dependence.
These patients did not suffer from sedative effects of this drug despite
important doses. We even noticed stimulating and euphorising effects in two of
these patients, an effect that may explain at least in part the dependence to
zolpidem. We will discuss the clinical similarities existing between zolpidem and
benzodiazepines' effects. Furthermore we will discuss a molecular genetic
hypothesis that may explain the differential effect of a specific benzodiazepine
ligand on its receptors.
PMID- 10668612
TI - [New antipsychotics in the treatment of schizophrenia. A European survey].
AB - Atypical antipsychotics (clozapine, risperidone, olanzapine, quetiapine,
sertindole) make up a much larger proportion of the prescriptions for
antipsychotic medications in the United States than in Europe. It is certain that
these atypical neuroleptics are not all available throughout Europe; nonetheless
the size of the disparity reveals certain tendencies in the different nations. In
an attempt to identify the reasons for the lesser usage of the new antipsychotics
in Europe, a telephone survey was conducted with 686 psychiatrists in 9
countries. This opinion survey was intended to identify, using open-ended
questions and multiple choice, the reasons for which practitioners have or have
not used the new antipsychotics; their perceived advantages and disadvantages in
comparison with typical antipsychotics; and the hindrances in prescribing them.
The results revealed that the new antipsychotics have a positive image with
psychiatrists: whereas they estimate the proportion of their patients using the
new antipsychotics to be at 50% (an amount larger than the objective European
amounts), more than 80% of psychiatrists say they would be ready to use them more
frequently if certain problems were overcome. Significant obstacles related to
the product are the cost and the lack of a depot formulation; two hindrances with
respect to the patient are the difficulty in using them in an emergency
situation, and the fear of destabilizing a patient who is well-controlled with a
classical treatment. The discussion re-addresses these points, using literature
relevant to the products and the patients. The European data, which are often
homogeneous, are discussed as a whole, with the exception of certain
characteristics that are specific to an individual country. French psychiatrists,
notably, serve as an exception, because they describe themselves as being more
restrained in their prescriptions because of the lack of a depot formulation
rather than because of the cost of the product.
PMID- 10668613
TI - [Between compliance and freedom: the patient's statement].
AB - According to the patient, obtaining a good compliance is related to a good
relationship with his practitioner; this relationship is directly connected to
being a good listener for the patient, and not only for their symptoms. If the
individual motivation is very important at the beginning, it will be itself
greatly influenced by the relationship between the practitioner and the patient.
It is one of the rare factors with a positive correlation with compliance, that's
what almost all of the researches on medical psychology have observed. Once the
problem is sumed up, it's the turn to speak for the patient, who explains how he
considers compliance.
PMID- 10668616
TI - [Drug-induced psychosis versus lupus-related psychosis: a report of a case].
PMID- 10668615
TI - [About ethics in psychiatry and psychiatrists facing ethics].
AB - The plug in account of the suffering, notably psychological, in a consultation,
puts the problem of the relationship between suffering and ethics. However, the
originality of the ethical step is justly not to be confined to the social norm
conformism, but being specific to the individual dimension. The psychiatric
pathology offers in this area of particularities interesting. The neurotic, as
the obsessed, suffering inwardly pathological manifestations that he judges
absurd, replies to the medical moral in asking a care. The psychotic, which
projects his suffering on the other, does not feel sick, requests no therapeutic
assistance. As such he contests the medical order in an immoral position by
definition, and the patient represents from then on a social and medical scandal.
In front of a such clinical diversity, we can easily underline that approaching
the theme of ethics in psychiatry isn't a well-off exercise, and necessitates a
precise locating registered in the history of the patient.
PMID- 10668614
TI - [Abuse of tianeptine. A case report].
AB - The authors report a case of tianeptine abuse in a 30 year-old woman. After a
medical prescription of the recommended dosage of 12.5 mg 3 times daily of oral
tianeptine for a depressive illness, the patient spontaneously increased the
dosage which after two months reached 150 tablets per day. No severe toxic
effects were observed. As adverse effects, the patient, in the beginning of this
high treatment period suffered from nausea, vomiting, abdominal pain, anorexia
with weight loss, constipation. These side effects progressively disappeared. The
biological tolerance was excellent, and hepatic parameters were not affected. The
patient experienced and seek a psychostimulant effect. After seven months of such
a therapy, she was hospitalized to undergo a withdrawal. The discontinuation of
the tianeptine treatment occurs in four days. A withdrawal syndrome marked by
myalgia, and cold feeling was transient, and alleviated by sedative phenothiazine
(cyamemazine) and myorelaxant benzodiazepine (tetrazepam).
PMID- 10668617
TI - [Perinatal psychopathology: some theoretical considerations].
PMID- 10668618
TI - In memoriam: Mara Selvini-Palazzoli, M.D. (1916-1999).
PMID- 10668619
TI - Dialectical behavior therapy--family skills training.
AB - Over the past three decades, family interventions have become important
components of treatment for a number of psychiatric disorders. To date, however,
there has been no family treatment designed specifically for borderline
personality disorder patients and their relatives. This article describes one
short-term family intervention called Dialectical Behavior Therapy-Family Skills
Training. Based on Linehan's Dialectical Behavior Therapy (DBT), borderline
patients' behavioral patterns are thought to result from a lifelong transaction
between emotional vulnerability and invalidating features of the social and
familial environment. Individual DBT focuses on reducing individual emotion
dysregulation and vulnerability and enhancing individual stability. The
complementary family interventions proposed in this article aim to: 1) provide
all family members an understanding of borderline behavioral patterns in a clear,
nonjudgmental way; 2) enhance the contributions of all family members to a
mutually validating environment; and 3) address all family members' emotion
regulation and interpersonal skills deficits.
PMID- 10668620
TI - Reconstructing the Brothers Grimm: new tales for step-family life.
AB - Step-families are situated within the sociopolitical context of family change and
are examined as a prototype of the "post-modern" family. This essay looks at the
cultural construction of step-family life and proposes a model for
collaboratively reconstructing stories that liberate step-relationships from the
legacy of the Brothers Grimm, deconstructing the stories of failure,
insufficiency, and neglect. Building on narrative and social constructionist ways
of thinking about families, the concept of side-shadowing (a hermeneutic approach
from literary/historical criticism) is introduced to elucidate how therapists can
help family members discover ways of thinking, feeling, and behaving that are
both more personally satisfying and more congruent with the changed context of
family life. Two therapeutic challenges are high-lighted: reconceptualizing what
it means to be a step-family and coming to terms with differential attachment in
relationships while working with step-families. The essay ends with a fairy tale
for the 21st century.
PMID- 10668621
TI - Attitudes toward and perceived psychosocial impact of female circumcision as
practiced among the Bedouin-Arabs of the Negev.
AB - The present pilot study examines attitudes toward and the perceived psychosocial
impact of circumcision as practiced among the Bedouin-Arabs of the Negev, Israel.
A convenience sample of 24 women participated in the study: 12 who had
experienced the ritual, and 12 who had not, but who had witnessed or been told
about the practice of the ritual on women in their extended families. Two
research instruments were used: a structured questionnaire, and a semi-structured
open-ended interview. Data showed differences in subject responses depending on
the research tools. The structured questionnaire revealed that women who had
experienced the circumcision gave legitimization and cognitive rationalization to
it. In contrast, the semi-structured interview revealed that these same subjects
reported insult: traumatization, direct negative influences, and narcissistic
insult, and described emotional difficulties during the research interviews. The
findings indicated that they had difficulties in mother-daughter relationships
and trust. Implications of the ritual on the continuity of polygamy and
marital/sexual problems are discussed.
PMID- 10668622
TI - A culturally sensitive approach to therapy with immigrant families: the case of
Jewish emigrants from the former Soviet Union.
AB - This article is based on accumulated clinical experience in Israel with families
that emigrated from the former Soviet Union. It describes a culturally sensitive
systemic intervention with two such families: a single-parent family, and a
family that exhibited physical violence. Relevant cultural characteristics of
family patterns and parent-child relationships in Jewish-Soviet families are
reviewed. It is demonstrated how a cross-cultural perspective may affect the
interpretation of presented problems and result in a less pathological
perspective. It is further illustrated how universal intervention techniques
combined with culturally sensitive approaches may produce positive effects in
therapy.
PMID- 10668623
TI - Family interaction styles of children with depressive disorders, schizophrenia
spectrum disorders, and normal controls.
AB - Family interaction processes during a problem-solving task were examined in
children with depressive disorders, children with schizophrenia-spectrum
disorders, and a normal control group of community children screened for the
absence of psychiatric disorder. Major findings were: a) children with depressive
disorders were more likely than children with schizophrenia-spectrum disorders
and children with no psychiatric disorder to direct guilt-inducing comments
toward their parents; and b) parents of children with schizophrenia-spectrum
disorders were more likely to direct harsh critical comments toward the child
than were parents of depressed children or parents of normal controls. In
addition, children's and mothers' use of benign criticism was linked, while
children's harsh criticism was associated with intrusion from the father, and
children's self-denigrating comments were related to specific paternal criticism.
Implications of these results for understanding transactional processes
associated with childhood-onset depressive and schizophrenia-spectrum disorders
are discussed.
PMID- 10668624
TI - Racial and gender differences in expressed emotion and interpersonal control in
families of persons with schizophrenia.
AB - Expressed Emotion (EE) has been shown to be predictive of course or severity in
many illnesses, but the studies have been largely of white middle-class patients.
This study examined gender and racial differences in parental EE level and
communication patterns between the parent and patient with schizophrenia, using
data from the NIMH Treatment Strategies in Schizophrenia study. Dialogues (n =
140) from 54 patient-parent dyads were coded into the Relational Control Coding
System. Resultant data (n = 13,605 sequences) were analyzed with log-linear
models. Results show that the relationship between control and EE level was
stronger in African American families compared to Caucasians. Gender differences
were as expected, with daughters less competitive and more deferential to their
parents. Although the total number of high-EE parents with daughters was small,
patterns in these families showed parents who responded submissively in contrast
to the competitive symmetry in families with male patients.
PMID- 10668625
TI - Factor analyses of the family assessment device.
AB - The Family Assessment Device (FAD) operationalizes the McMaster Model of Family
Functioning, which has been used in numerous studies, translated into seven
languages, and is regarded as one of the most researched family assessment tools
available. However, exploratory and confirmatory factor analyses using the 7-by-7
matrix of subscale correlations from the original validity study on the FAD
(Epstein, Baldwin, & Bishop, 1983) indicated that the FAD subscales overlap
substantially and do not assess unique dimensions of family functioning. Results
of our study suggest that the conservatively best use of the FAD is using the
General Functioning subscale as a summary score. A model that fits the data
marginally better than the General Functioning score and a Measurement Error
model, however, consisted of "Collaboration" and "Commitment" latent factors.
These results illustrated the need for more extensive validity research on the
FAD, because interpretation of the factors and subscales had to rely heavily on
face validity.
PMID- 10668626
TI - Studies on a "jumping gene machine": higher-order nucleoprotein complexes in Mu
DNA transposition.
AB - Studies in my lab have focused on DNA transposition in the bacterial virus, Mu.
In vitro studies have shown that Mu DNA transposition is a three-step process
involving DNA breakage, strand transfer and DNA replication. In the first step, a
nick is introduced at each end of the transposon. The liberated 3'-OH groups
subsequently attack a target DNA molecule resulting in strand transfer. The
transposon DNA, now covalently linked to the target, is finally replicated to
generate the transposition end-product, referred to as a cointegrate. The DNA
cleavage and strand transfer reactions are mediated by a "jumping gene machine"
or transpososomes, which we discovered in 1987. They are assembled by bringing
together three different DNA regions via a process involving multiple protein-DNA
and protein-protein interactions. The action of four different proteins is
required in addition to protein-induced DNA bending or wrapping to overcome the
intrinsic stiffness of DNA, which would ordinarily prohibit the assembly of such
a structure. Transpososome assembly is a gradual process involving multiple steps
with an inherent flexibility whereby alternate pathways can be used in the
assembly process, biasing the reaction towards completion under different
conditions.
PMID- 10668627
TI - Roles of protein tyrosine phosphatases in cell migration and adhesion.
AB - Signal transduction pathways are often seen as cascades of kinases, whereas
phosphatases are relinquished to the housekeeping function of resetting the
individual elements to a resting state. However, critical biological processes
such as cellular migration require a coordinated and constant remodeling of the
actin cytoskeleton as well as a rapid turnover of the cell-substratum linkages
that necessitate the concomitant action of antagonistic enzymes. Tyrosine
phosphorylation was long known to be involved in adhesion and de-adhesion
mediated via the integrin receptors. As the roles of tyrosine kinases such as
focal adhesion kinase, c-Src, and Csk in this pathway are being extensively
studied, increasing evidence is emerging about the importance of protein tyrosine
phosphatases (PTP). In this review we discuss examples of PTPs that were recently
shown to play a role in cell adhesion and migration and their mechanism of
action.
PMID- 10668628
TI - Identification of the Escherichia coli enzyme I binding site in histidine
containing protein, HPr, by the effects of mutagenesis.
AB - The structure of the N-terminal domain of enzyme I complexed with histidine
containing protein (HPr) has been described by multi-dimensional NMR. Residues in
HPr involved in binding were identified by intermolecular nuclear Overhauser
effects (Garrett et al. 1999). Most of these residues have been mutated, and the
effect of these changes on binding has been assessed by enzyme I kinetic
measurement. Changes to Thr16, Arg17, Lys24, Lys27, Ser46, Leu47, Lys49, Gln51,
and Thr56 result in increases to the HPr Km of enzyme I, which would be
compatible with changes in binding. Except for mutations to His15 and Arg17, very
little or no change in Vmax was found. Alanine replacements for Gln21, Thr52, and
Leu55 have no effect. The mutation Lys40Ala also affects HPr Km of enzyme I;
residue 40 is contiguous with the enzyme I binding site in HPr and was not
identified by NMR. The mutations leading to a reduction in the size of the side
chain (Thr16Ala, Arg17Gly, Lys24Ala, Lys27Ala, and Lys49Gly) caused relatively
large increases in Km (>5-fold) indicating these residues have more significant
roles in binding to enzyme I. Acidic replacement at Ser46 caused very large
increases (>100-fold), while Gln51Glu gave a 3-fold increase in Km. While these
results essentially concur with the identification of residues by the NMR
experiments, the apparent importance of individual residues as determined by
mutation and kinetic measurement does not necessarily correspond with the number
of contacts derived from observed intermolecular nuclear Overhauser effects.
PMID- 10668629
TI - Inhibition of retinoic acid-inducible transcription by COUP-TFI in human salivary
gland adenocarcinoma cell line HSG.
AB - Human salivary gland adenocarcinoma cells (HSG) express nuclear receptors, all
trans-retinoic acid (at-RA) receptors (RARs), and retinoid X/9-cis-retinoic acid
(9-c-RA) receptors (RXRs). In order to investigate whether the endogenous RARs or
RXRs of HSG cells can induce transcription activation, the thymidine kinase
promoter (TK)-driven luciferase reporter gene containing the retinoic acid
response element (RARE), of RARbeta, betaRARE2-TK-Luc, was transfected into HSG
cells and ligand-dependent transcription activation was examined. Luciferase
activity of cell lysate increased by the treatment with either at-RA or 9-c-RA.
Co-transfection of RARalpha and (or) RXRalpha-expression plasmids with the
reporter gene enhanced the luciferase activity, suggesting that endogenous RARs
and RXRs work as ligand-dependent transfactors in HSG cells. Reverse
transcriptase - polymerase chain reaction analysis revealed that HSG cells
express chicken ovalbumin upstream promoter - transcription factor I (COUP-TFI).
Co-transfection of COUP-TFI-expression plasmid suppressed the at-RA-induced
transcription activation of the reporter gene. Similar results were shown using a
chromatin-integrated reporter gene system, using a stably transfected beta-RARE2
TK-beta-galactosidase (beta-Gal) reporter gene. The at-RA-dependent increase in
the beta-Gal expression was completely inhibited by COUP-TFI. The transfection of
antisense oligonucleotide of COUP-TFI squelched the RA-dependent growth
inhibition induced by RAR-RXR heterodimers. Conclusively, RARs and RXRs of HSG
cells are functional and play roles as transactivators in at-RA-sensitive
processes such as the proliferation or differentiation of cells. COUP-TFI very
likely regulates these processes by repressing the functions of these
transactivators.
PMID- 10668630
TI - Cell adhesion and the actin cytoskeleton of the enveloping layer in the zebrafish
embryo during epiboly.
AB - As the zebrafish embryo undergoes gastrulation and epiboly, the cells of the
enveloping layer (EVL) expand, covering the entire yolk cell. During the epiboly
process, the EVL cells move as a coherent layer, remaining tightly attached to
each other and to the underlying yolk syncytial layer (YSL). In view of the
central role of the actin cytoskeleton, in both cell motility and cell-cell
adhesion, we have labeled these cells in situ with fluorescent phalloidin and
anti-actin antibodies. We show that, throughout their migration, the EVL cells
retain a conspicuous cortical actin cytoskeletal belt coinciding with cell
surface cadherins. At the margins approaching the YSL, the EVL cells extend, from
their apicolateral domains, actin-rich filopodial protrusions devoid of
detectable cadherin. We have studied the role of the actin cytoskeleton in the
maintenance of EVL cohesion during epiboly. Cytochalasin treatment of embryos
induces EVL dissociation accompanied by general detachment of the rest of the
embryonic cells. In the dissociating EVL cells, the cortical actin belt undergoes
fragmentation with the formation of actin aggregates; cadherins, on the other
hand, remain evenly distributed at the junctional cell surface. Removal of Ca2+
by ethyleneglycolbis (amino-ethyl-ether)-tetraacetic acid (EGTA) treatment also
induces cell dissociation without visible disruption of the cortical actin belt.
The protein kinase inhibitor (1-isoquinolinylsulfonyl)-2-methyl-piperazine
dihydrochloride (H-7), which blocks acto-myosin contractility and disrupts actin
cables in cultured cells, also potentiates cytochalasin-induced dissociation and
promotes the projection of numerous actin-rich lamellipodial extensions. The fact
that EVL cells produce microspike-like structures towards the YSL and are capable
of lamellipodial activity lend further support to the suggestion (R.W. Keller and
J.P. Trinkaus. 1987. Dev. Biol. 120: 12-24) that the EVL cells are not passively
mobilized on the expanding YSL but actively participate in epiboly.
PMID- 10668631
TI - Anion binding characteristics of the band 3 / 4,4-dibenzamidostilbene-2,2
disulfonate binary complex: evidence for both steric and allosteric interactions.
AB - A novel kinetic approach was used to measure monovalent anion binding to better
define the mechanistic basis for competition between stilbenedisulfonates and
transportable anions on band 3. An anion-induced acceleration in the release of
4,4'-dibenzamidostilbene-2,2'-disulfonate (DBDS) from its complex with band 3 was
measured using monovalent anions of various size and relative affinity for the
transport site. The K1/2 values for anion binding were determined and correlated
with transport site affinity constants obtained from the literature and the
dehydrated radius of each anion. The results show that anions with ionic radii of
120-200 pm fall on a well-defined correlation line where the ranking of the K1/2
values matched the ranking of the transport site affinity constants (thiocyanate
< nitrate approximately bromide < chloride < fluoride). The K1/2 values for the
anions on this line were about 4-fold larger than expected for anion binding to
inhibitor-free band 3. Such a lowered affinity can be explained in terms of
allosteric site-site interactions, since the K1/2 values decreased with
increasing anionic size. In contrast, iodide, with an ionic radius of about 212
pm, had a 10-fold lower affinity than predicted by the correlation line
established by the smaller monovalent anions. These results indicate that smaller
monovalent anions have unobstructed access to the transport site within the band
3 / DBDS binary complex, while iodide experiences significant steric hindrance
when binding. The observation of steric hindrance in iodide binding to the band 3
/ DBDS binary complex, but not in the binding of smaller monovalent anions,
suggests that the stilbenedisulfonate binding site is located at the outer
surface of an access channel leading to the transport site.
PMID- 10668632
TI - Identification of sds21 in fission yeast in an inhibitor-resistant high molecular
mass protein phosphatase-1 complex.
AB - While characterizing the type-1 protein phosphatases sds21 and dis2 in fission
yeast (Schizosaccharomyces pombe) a novel high molecular mass protein was
identified with serine/threonine phosphatase activity (referred to as PP-R) that
was resistant to a panel of characteristic inhibitors of protein phosphatases.
Purification of the native sds21 catalytic isoform of protein phosphatase-1 (PP
1) from an S. pombe knockout strain lacking dis2 (deltadis2) resulted
predominantly in identification of PP-R. To test the hypothesis that the
catalytic activity of PP-R comprised sds21, a parallel purification was performed
of PP-1 activity from an S. pombe knockout strain lacking sds21 (deltasds21).
Both deltasds21 and deltadis2 strains exhibited similar protein phosphatase
activity profiles as determined by DEAE-sepharose, Mono-Q and Superdex gel
filtration chromatography. However, the peak of protein phosphatase activity from
deltasds21 S. pombe that co-migrated with PP-R from deltadis2 S. pombe exhibited
the sensitivity to a panel of inhibitors that was characteristic of a type-1
protein phosphatase. These data suggest that the catalytic subunit of PP-R
comprises sds21 and that the resistance to inhibitors may originate from
structural differences between dis2 and sds21 isoforms. A key structural feature
present in sds21, but lacking in dis2, is a classical phosphorylation consensus
sequence surrounding serine-145 of sds21. The previous hypothesis was that PP-1
activity among several lower eukaryotes may be regulated directly by cAMP
dependent protein kinase (PKA) phosphorylation. However, this study demonstrated
that recombinant sds21 is not a target for PKA in vitro. The constrained
configuration of the putative PKA site on the PP-1 holoenzyme may restrict its
ability to be targeted by PKA.
PMID- 10668633
TI - Ischemia induced activation of heat shock protein 27 kinases and casein kinase 2
in the preconditioned rabbit heart.
AB - Protein kinase C (PKC), p38 MAP kinase, and mitogen-activated protein kinase
activated kinases 2 and 3 (MAPKAPK2 and MAPKAPK3) have been implicated in
ischemic preconditioning (PC) of the heart to reduce damage following a
myocardial infarct. This study examined whether extracellular signal-regulated
kinase (Erk) 1, p70 ribosomal S6 kinase (p70 S6K), casein kinase 2 (CK2), and
other hsp27 kinases are also activated by PC, and if they are required for
protection in rabbit hearts. CK2 and hsp27 kinase activities declined during
global ischemia in control hearts, whereas PC with 5 min ischemia and 10 min
reperfusion increased their activities during global ischemia. Resource Q
chromatography resolved two distinct peaks of hsp27 phosphotransferase
activities; the first peak (at 0.36 M NaCl) appeared to correspond to the 55-kDa
MAPKAPK2. Erk1 activity was elevated in both control and PC hearts after post
ischemic reperfusion, but no change was observed in p70 S6K activity. Infarct
size (measured by triphenyltetrazolium staining) in isolated rabbit hearts
subjected to 30 min regional ischemia and 2 h reperfusion was 31.0+/-2.6% of the
risk zone in controls and was 10.3+/-2.2% in PC hearts (p<0.001). Neither the CK2
inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) nor the Mek1/2
inhibitor PD98059 infused during ischemia blocked protection by PC. The
activation of CK2 and Erk1 in ischemic preconditioned hearts appear to be
epiphenomena and not required for the reduction of infarction from myocardial
ischemia.
PMID- 10668634
TI - Fibroblast growth factor-2 stimulates phospholipase Cbeta in adult
cardiomyocytes.
AB - Although fibroblast growth factor-2 (FGF-2) plays an important role in
cardioprotection and growth, little is known about the signals triggered by it in
the adult heart. We therefore examined FGF-2-induced effects on phosphoinositide
specific phospholipase C (PI-PLC) isozymes, which produce second messengers
linked to the inotropic and hypertrophic response of the myocardium. FGF-2,
administered by retrograde perfusion to the isolated heart, induced an increase
in inositol-1,4,5-trisphosphate levels in the cytosol, as well as an increase in
total PI-PLC activity associated with sarcolemmal and cytosolic fractions.
Furthermore FGF-2 induced a time-dependent elevation in cardiomyocyte membrane
associated PLC gamma1 and PLC beta1 activities, assayed in immunoprecipitated
fractions, and moreover, increased the membrane levels of PLC beta1 and PLC
beta3. Activation of PLC beta is suggestive of FGF-2-induced cross-talk between
FGF-receptor tyrosine kinase and G-protein-coupled signaling in adult
cardiomyocytes and underscores the importance of FGF-2 in cardiac physiology.
PMID- 10668636
TI - The expression of transforming growth factor-beta and interleukin-1beta mRNA and
the response to 1,25(OH)2D3' 17 beta-estradiol, and testosterone is age dependent
in primary cultures of mouse-derived osteoblasts in vitro.
AB - The aim of the present study was to examine the hypothesis that primary cultures
of osteoblasts obtained from bones of young animals respond to hormones better
than cell cultures obtained from old animals. We studied in cultured osteoblastic
cells the effects of 1,25(OH)2D3 and sex steroid hormones on several mouse
osteoblastic phenotypic expressions including transforming growth factor-beta
(TGF-beta) and interleukin-1beta (IL-1beta) mRNAs. Second passages of long bone
derived osteoblastic cells from young donors (5-12 wk) and old donors (10-12 mo
old) were used for this study. The cells obtained from old animals had decreased
ALP activity and cAMP compared with cells obtained from young animals with no
change in collagen production and mineralization. The addition of 17beta
estradiol and testosterone increased ALP activity and mineralization in the
cultured cells from both age groups and collagen production in cells obtained
from old mice. Using in situ hybridization IL-1beta and TGF-beta mRNA expression
was observed to be higher in the osteoblasts from young than from old donors.
1,25(OH)2D3 increased IL-1beta mRNA expression in the cells derived from young
mice. Testosterone and 17beta-estradiol inhibited IL-1beta mRNA expression only
in cells derived from young mice. Sex steroid hormones did not change TGF-beta
mRNA expression in any of the cell lines, but 1,25(OH)2D3 increased its
expression in cells derived from old donors. The results of the present study
indicate that cells obtained from old mice are generally less active than those
obtained from young animals.
PMID- 10668635
TI - DHEA and the skeleton (through the ages).
AB - Dehydroepiandrosterone (DHEA) and its sulfate ester, DHEAS, are the most abundant
steroids in the human circulation, although their exact biological significance
is not completely understood. DHEA(S) levels are high in fetal life, decrease
after birth, and show a marked pubertal increase to a maximal level during young
adulthood. In healthy adults, DHEAS levels decline to 10-20% of peak levels by
age 70 yr. This review summarizes information concerning the role of DHEA in
skeletal physiology, including modulation of the skeletal insulin-like growth
factor regulatory system, and its effects on secretion of proresorptive
cytokines. The pattern of secretion of DHEA throughout the life cycle is
discussed, as well as its potential usefulness in specific disease states as an
agent with anabolic and antiosteolyic effects on bone.
PMID- 10668637
TI - Androgen receptor mRNA expression in the rhesus monkey ovary.
AB - Immunocytochemical detection of androgen receptors (ARs) in several compartments
of the macaque ovary, including the germinal epithelium, follicle, and corpus
luteum, suggests a role for androgens in modulating ovarian function via the
classical receptor-mediated pathway. To examine AR mRNA expression in the rhesus
monkey ovary, total RNA was isolated from whole ovaries, the germinal epithelium
enriched cortical and medullary compartments of the ovary, and corpora lutea from
early (d 3-5), mid (d 6-8), mid-late (d 10-12), and late (d 13-15) stages of the
luteal phase of the menstrual cycle. RNA was also obtained from luteinized
granulosa cells from monkeys receiving gonadotropin treatment to stimulate the
development of multiple ovarian follicles. After reverse transcription of total
RNA using oligo-dT as a primer, polymerase chain reaction (PCR) was used to
amplify a unique 329 bp segment of the monkey AR hormone-binding region. Reverse
transcriptase (RT)-PCR products of the expected size were detected in all ovarian
and control tissues. Sequence analysis of the AR cDNA from the macaque ovary
revealed 99% nucleotide homology and 100% predicted amino acid homology to the
cDNA for the hormone-binding region of human AR. Northern analysis demonstrated
the presence of a major AR mRNA species at 9.5 kb in corpus luteum, luteinized
granulosa cells, and prostate, with additional bands detected in the corpus
luteum and prostate at 7.9 and 3.4 kb, respectively. A sensitive RNase protection
assay was used to examine AR mRNA levels in ovarian tissues and showed AR mRNA
expression throughout the life-span of the corpus luteum. Thus, detection of AR
mRNA in the primate ovary, including the periovulatory follicle and corpus
luteum, supports the concept that these tissues are targets for receptor-mediated
androgen action during the menstrual cycle.
PMID- 10668638
TI - Antisteroidogenic action of nitric oxide on human corpus luteum in vitro:
mechanism of action.
AB - To analyze the mechanism by which nitric oxide (NO) exerts its antisteroidogenic
action, human luteal cells were cultured during 24 and 48 h with L-arginine (L
Arg, 1 mmol/L); 1,2(2-trifluoromethylphenyl)imidazole (TRIM) (50 micromol/L and 1
mmol/L) and cyclic guanosine monophosphate (cGMP) analog (8-Br-cGMP, 1 mmol/L).
Estradiol, nitrite, and P450 AROM activity were determined in culture media.
Total cGMP concentration was evaluated in the cells and culture media by
radioimmunoassay, and NADPH diaphorase was used as a histochemical marker for NO
synthase (NOS) activity. During the corpus luteum (CL) life-span, NO affected
estradiol secretion in an age-dependent manner, with an inhibition in mid-CL
(37%; p < 0.05) in agreement with our previous results, and no significant
modification in early and late CL. Basal nitrite concentration in 24 and 48 h of
midluteal cell cultures (42 and 93 pmol/10(6) cells, respectively) was increased
by L-Arg (53% and 88%) and inhibited by the two TRIM concentrations; also, an
intense diaphorase reactivity was observed in endothelial cells and luteal
parenchyma. Total cGMP was not detected in cell cultures and 8-Br-cGMP did not
modify estradiol secretion, whereas aromatase activity was strongly inhibited by
L-Arg (70%, p < .05). These results suggest that both NOS isoforms are active in
midluteal cells, and the mechanism of action for NO on in vitro estradiol
secretion may be an inhibition of P450 AROM activity.
PMID- 10668639
TI - The effect of hypoxia on plasma leptin and insulin in newborn and juvenile rats.
AB - Hypoxia leads to a decrease in food intake and attenuated weight gain in rats.
The purpose of this study was to measure plasma leptin and insulin in young rats
exposed to hypoxia for 7 d as compared to a normoxic control group of the same
age. One group was exposed from birth to 7 d of age; the other was exposed from
28 to 35 d of age (weaned at 21 d of age). As expected, body weight was
significantly lower in rats of either age exposed to hypoxia for 7 d. Plasma
leptin was significantly lower in hypoxic (2.0+/-0.2 ng/mL; n = 41) compared with
normoxic (2.6+/-0.3 ng/mL; n = 30) 7-d-old rats. Plasma leptin was also
significantly lower in hypoxic (1.1+/-0.1 ng/mL; n = 20) as compared to normoxic
(1.5+/-0.1 ng/mL; n = 20) 35-d-old rats. Seven-day-old rats exposed to hypoxia
demonstrated significant increases in plasma glucose and insulin whereas 35-d-old
rats exhibited a decrease in both variables. We conclude that exposure to hypoxia
for 7 d leads to a decrease in body weight and plasma leptin in infant and
juvenile rats. The decrease in leptin may be an attempt to reverse hypoxia
induced anorexia.
PMID- 10668640
TI - Antioxidative mechanisms and plasma growth hormone levels: potential relationship
in the aging process.
AB - Factors affecting longevity are complex and poorly understood. We have recently
found that Ames dwarf mice (df/df), which are deficient in growth hormone (GH),
prolactin, and thyroid-stimulating hormone, live significantly longer than their
normal siblings whereas transgenic mice that overexpress GH exhibit reduced life
spans and various indices of premature aging. The production of reactive oxygen
species increases with aging and is associated with DNA damage to the tissues.
However, several cellular oxygen scavenging/detoxifying systems exist that
improve the antioxidative defense capacity of cells. We evaluated the activity of
enzymes involved in this defense system in liver, kidney, and heart tissue from
dwarf, phosphoenol-pyruvate carboxykinase-bovine GH transgenic, and corresponding
groups of normal mice. Liver glutathione and ascorbate levels were lower (p <
0.0025) in dwarf animals compared to normal and GH transgenic mice. By contrast,
the level of catalase activity, which detoxifies hydrogen peroxide, in dwarf
liver and kidney was significantly higher when compared to the other groups.
Animals deficient in GH (dwarf) live longer and exhibit enzyme activities and
levels that may combat oxidative stress more efficiently than normal mice and
those overexpressing GH.
PMID- 10668641
TI - Homologous upregulation of GnRH receptor mRNA by continuous GnRH in cultured rat
pituitary cells.
AB - The present study examined the effects of continuous treatment with gonadotropin
releasing hormone (GnRH) on GnRH receptor (GnRH-R) mRNA levels in dispersed
cultures of rat pituitary cells. Pituitary GnRH-R mRNA levels were determined by
competitive reverse transcriptase polymerase chain reaction. When pituitary cells
were continuously exposed to a low dose of GnRH (0.2 nM), GnRH-R mRNA levels were
transiently increased. The levels of GnRH-R mRNA were significantly increased up
to 6 h and diminished to untreated levels by 24 h. Luteinizing hormone (LH)
release was also increased significantly up to 12 h, maintaining similar levels
in LH release thereafter. When GnRH antagonist ([D-pGlu1, D-Phe2, D-Trp3,6]-LH
RH) was added to the cultures together with GnRH (0.2 nM) for 6 h, the
stimulatory effect of GnRH on GnRH-R mRNA levels and LH release was significantly
diminished in a dose-related manner. In another experiment, pituitary cells were
treated with various doses of GnRH (0.02-200 nM) for a relatively short (6 h) or
a longer (24 h) period. When pituitary cells were exposed for 6 h, all doses of
GnRH (0.02-200 nM) significantly increased GnRH-R mRNA levels in a dose-dependent
manner. By contrast, continuous exposure to GnRH for 24 h was ineffective in
changing pituitary GnRH-R mRNA levels at any given doses. These results indicate
that the duration of GnRH treatment is critical for upregulation of GnRH-R mRNA
by continuous GnRH. When pituitary cells were treated for 6 h with either a
continuous mode of GnRH (0.2 nM) or an hourly pulsatile mode of GnRH (0.2 nM, 6
min/h), both treatments significantly augmented GnRH-R mRNA levels. Thus, the
modes of GnRH application, if treated for a relatively short period, do not
appear to make a significant difference in upregulation of GnRH-R mRNA levels.
Collectively, our data provide strong evidence that continuous GnRH application
is able to upregulate pituitary GnRH-R mRNA levels, if treated for a relatively
short period (6 h).
PMID- 10668642
TI - Enhanced platelet aggregation, high homocysteine level, and microvascular disease
in diabetic muscle infarctions: implications for therapy.
AB - Muscle infarction is a rare complication in patients with diabetes mellitus,
probably because of the rich vascular supply of this tissue. We describe a
patient with type 1 diabetes who had infarction of the muscles in her right
thigh. We report, for the first time, that the patient, in addition to an
advanced microvascular disease in the muscle, had increased plasma total
homocysteine levels and increased platelet aggregation. These pathologies might
have a synergistic effect on the development of this rare complication and should
be treated aggressively to prevent further episodes.
PMID- 10668643
TI - Testicular abnormalities in male rats after lactational exposure to nonylphenols.
AB - Lactational exposure of male rat pups to nonylphenols (NPs) decreased the size of
their testes and male accessory glands. At 31 d of age, NP-treatment of male rats
resulted in less cellular differentiation of the seminiferous tubules (STs) and
increased intertubular space compared to controls. At maturity, NP-treated males
showed varying degrees of abnormalities in the affected testes. In the moderately
affected ones, about 20-30% of their STs had poorly differentiated germinal
elements. Cell lineage was less organized. In extreme cases, all STs of the
affected testis failed to differentiate into germinal elements. These
abnormalities in germinal element differentiation might be the primary cause for
a number of the NP-treated males having a lower epididymal sperm count and a
lower percentage of motile sperm compared to age-matched control males. Zymogram
analysis of testis homogenates by sodium dodecyl sulfate gelatin gels revealed
two major forms (64-66 kDa and 50-52 kDa) of gelatinases. Only the 50-52-kDa form
was greatly reduced or absent in the affected testis. Lactational exposure of
male pups to NPs thus leads to various testicular abnormalities including lack of
differentiation of STs, lowering of sperm count, and reduction in the percentage
of motile sperm and modulation of a specific form of testicular proteinases.
PMID- 10668644
TI - TGF-alpha exerts biphasic effects on estrogen--and phytoestrogen-mediated gene
expression in breast cancer cells.
AB - Transforming growth factor-alpha (TGF-alpha) contributes to the progression of
mammary carcinogenesis in part through synergistic augmentation of estradiol (E2)
action. To investigate this further, we sought to determine (1) whether the
duration of TGF-alpha treatment might influence the nature of the TGF-alpha/E2
interaction, and (2) whether TGF-alpha would behave in a similar manner when
combined with phytoestrogens. To this end, we transfected T47-D breast cancer
cells with an estrogen-responsive reporter and then treated the cells (for 4-48
h) with varying concentrations of TGF-alpha, E2, the antiestrogen 4-hydroxy
tamoxifen (HOT), and/or one of three phytoestrogens. Our findings revealed that
TGF-alpha has short-term synergistic and long-term inhibitory effects on E2- and
phytoestrogen-regulated gene expression. Furthermore, this secondary inhibition
of E2 action by TGF-alpha was similar in magnitude to that imposed by HOT. These
findings demonstrate a novel role for TGF-alpha and invite reevaluation of
current models regarding TGF-alphas interactions with E2 in breast cancer cells.
Our results also raise the possibility that phytoestrogens, which interact with
TGF-alpha in a manner conceptually identical to that of E2, may subserve a
regulatory function in breast cancer cells.
PMID- 10668645
TI - Inhibition of hypothalamic GnRH secretion in the ewe by antigonadotropic
decapeptide during the estrous cycle and nonbreeding season.
AB - Previous experiments from our laboratory and others have shown that the peptide
antigonadotropic decapeptide (AGD) has marked inhibitory effects on luteinizing
hormone (LH) secretion in rats and ewes. The first objective of this study was to
determine whether AGD inhibits LH secretion by regulating hypothalamic release of
gonadotropin hormone (GnRH). AGD (200 microg in 200 microL of 0.3% bovine serum
albumin [BSA] saline) or vehicle was infused into the lateral ventricle of
ovariectomized (OVX) ewes with hypophyseal-portal cannulae, and GnRH secretion
was monitored. The frequency of GnRH and LH pulses in AGD-treated ewes was
significantly decreased (p < 0.05) but did not change in the control ewes. The
second objective of this investigation was to evaluate changes in hypothalamic
sensitivity to AGD in the ewe during the estrous cycle and nonbreeding season.
During the estrous cycle, the effects of AGD on LH secretion were assessed
following ovariectomy, during the metestrous, diestrous, and proestrous phases of
the estrous cycle. The response to AGD during the estrous cycle was compared to
its effect during the anestrous season. LH, cortisol, and prolactin (PRL)
concentrations were assayed in peripheral blood samples obtained at 10-min
intervals over a 6-h period prior to injection of either vehicle (200 microL of
0.3% BSA in 0.9% saline) or AGD (200 microg in 200 microL of vehicle), and for an
additional 10 h following treatment. LH pulse frequency decreased after treatment
with AGD (p < 0.05) at all times in OVX and intact ewes compared to vehicle
treated controls. During the anestrous season, AGD treatment was more effective
in inhibiting LH pulse frequency than during the breeding season (p < 0.05).
Furthermore, there was a significant increase (p < 0.05) in mean cortisol
concentrations after AGD infusion in all AGD-treated groups compared to controls
independent of season or reproductive status. PRL concentrations were also
increased (p < 0.05) following treatment with AGD. These results suggest that
inhibition of pulsatile LH release induced by AGD is modulated by alterations in
frequency of hypothalamic discharges of GnRH. Furthermore, changes in the
inhibitory actions of AGD may contribute to the seasonal regulation of
hypothalamic GnRH secretion in the ewe.
PMID- 10668646
TI - Mutations in the gene encoding the alpha-subunit of the Gs protein in molar
pregnancy.
AB - Molar pregnancy is a gestational trophoblastic disease associated with a
trophoblastic proliferation and a protein synthesis alteration. It is
characterized by the presence of hydatiform moles, which are fluid-filled cysts
derived from the chorionic villi of the placenta. Recent studies have reported a
reduced expression of several types of G proteins including Gsalpha in molar
pregnancies suggesting alterations in G protein structure in hydatiform moles. To
identify mutations that lead to Gsalpha deficiency, we isolated genomic DNA from
hydatiform moles and used polymerase chain reaction to amplify all exons of the
Gsalpha gene. Amplified Gsalpha gene fragments were analyzed by sequencing using
the dideoxy chain termination method. Tissues obtained from three complete
hydatiform moles and one partial hydatiform mole were examined. We have
identified a heterozygous 8-bp deletion in exon 10 of the Gsalpha gene, in two
complete hydatiform moles, that had evidence for a dysfunctional Gsalpha protein.
This deletion produced a truncated protein. We have also identified a
heterozygous polymorphism in exon 5 in two complete hydatiform moles, and a
homozygous substitution (A-->G) in intron 5 of the Gsalpha gene in the other
complete hydatiform mole; these two last types of mutations should not have any
effects on protein activity.
PMID- 10668647
TI - Expression of prolactin receptor mRNA is increased in the preoptic area of
lactating rats.
AB - This study investigated expression of prolactin receptor (PRL-R) mRNA in the
preoptic area in midlactating rats compared with diestrous rats. Tissues from
specific nuclei were micropunched from 300-microm thick rat brain sections with
300- or 500-microm diameter needles. After total RNA was extracted, the two forms
of PRL-R mRNA were evaluated by reverse transcriptase polymerase chain reaction
and Southern hybridization. The results showed that levels of long-form PRL-R
mRNA in the ventrolateral preoptic nucleus and lateroanterior nucleus in
lactating rats were significantly higher (p < 0.05) than in diestrous rats. The
ventromedial and medial preoptic nuclei in lactating rats also expressed
moderately high levels of long-form mRNA when compared with (p = 0.0547)
diestrous rats. The ventromedial and ventrolateral preoptic nuclei, and
ventrolateral hypothalamic nucleus in lactating rats expressed significantly
higher levels of short-form mRNA than in diestrous rats. The increased expression
of both forms of PRL-R mRNA helps explain numerous effects of PRL on brain
functions during lactation.
PMID- 10668648
TI - Nitric oxide and hydroperoxide affect islet hormone release and Ca(2+) efflux.
AB - We have investigated the influence of the intracellular free radical donors
hydroxylamine (giving nitric oxide [NO]) and tert-butylhydroperoxide (giving
hydroperoxide ["H2O2"]) on glucose- and cyclic adenosine monophosphate (cAMP)
induced transduction signaling in islet hormone release. Both donors dose
dependently inhibited glucose-stimulated insulin release and induced modest
(hydroxylamine) or profound (tertbutylhydroperoxide) suppression of 45Ca2+-efflux
from perifused islets. By contrast, both donors stimulated glucagon release.
Similar effects on hormone release were displayed after K+-depolarization.
Insulin and glucagon release stimulated by activation of the cAMP system through
isobutylmethylxanthine (IBMX) at basal glucose was modestly potentiated by low
concentrations of both donors. These effects were still observed, although less
pronounced, in K+-depolarized islets. In vitro as well as in vivo, the NO
synthase inhibitor N(G)-nitro-L-arginine methyl ester inhibited IBMX-induced
glucagon release, but did not affect insulin release. The results suggest that NO
and hydroperoxide inhibit glucose-stimulated insulin release by perturbing Ca2+
fluxes and probably acting through S-nitrosylation (NO) or oxidation
(hydroperoxide) of thiol groups critical to the secretory process. These effects
are largely independent of depolarization events. By contrast, both NO and
hydroperoxide can potentiate cAMP-stimulated hormone release presumably at a
distal site in the stimulus-secretion coupling.
PMID- 10668649
TI - Cross-modal generalization effects of training noncanonical sentence
comprehension and production in agrammatic aphasia.
AB - The cross-modal generalization effects of training complex sentence comprehension
and complex sentence production were examined in 4 individuals with agrammatic
Broca's aphasia who showed difficulty comprehending and producing complex,
noncanonical sentences. Object-cleft and passive sentences were selected for
treatment because the two are linguistically distinct, relying on wh-and NP
movement, respectively (Chomsky, 1986). Two participants received comprehension
training, and 2 received production training using linguistic specific treatment
(LST). LST takes participants through a series of steps that emphasize the verb
and verb argument structure, as well as the linguistic movement required to
derive target sentences. A single-subject multiple-baseline design across
behaviors was used to measure acquisition and generalization within and across
sentence types, as well as cross-modal generalization (i.e., from comprehension
to production and vice versa) and generalization to discourse. Results indicated
that both treatment methods were effective for training comprehension and
production of target sentences and that comprehension treatment resulted in
generalization to spoken and written sentence production. Sentence production
treatment generalized to written sentence production only; generalization to
comprehension did not occur. Across sentence types generalization also did not
occur, as predicted, and the effects of treatment on discourse were inconsistent
across participants. These data are discussed with regard to models of normal
sentence comprehension and production.
PMID- 10668650
TI - The effects of inflectional variation on fast mapping of verbs in English and
Spanish.
AB - To use morphological cues for syntactic bootstrapping, children must recognize
that inflectionally varying words (e.g., pushes, pushed) are instances of the
same word. Children who are exposed to languages with richer inflectional
morphologies than English, such as Spanish, encounter instances of inflectional
variation more often. Thus they may learn to recognize inflectionally varying
words as instances of the same word at an earlier age than do learners of
English. English-and Spanish-learning 3-year olds were taught novel verbs in a
fast mapping task under two conditions: no-inflectional variation in which
inflections did not vary between exposure and testing (e.g., neps, neps) and
inflectional variation in which inflections alternated between exposure and
testing (e.g., neps, nepped). Children's scores were significantly higher in the
no-variation condition than in the variation condition. There were no significant
differences between the performance of the language groups. These findings
suggest that even children acquiring languages with relatively rich verbal
inflection paradigms may not be able to consistently parse stems and inflections
to associate inflectionally varying forms.
PMID- 10668651
TI - Narrative production by children with and without specific language impairment:
oral narratives and emergent readings.
AB - The research reported in this paper was based on the premise that oral and
written language development are intertwined. Further, the research was motivated
by research demonstrating that narrative ability is an important predictor of
school success for older children with language impairment. The authors extended
the inquiry to preschool children by analyzing oral narratives and "emergent
storybook reading" (retelling of a familiar storybook) by two groups of 20
children (half with, half without language impairment) age 2;4 (years;months) to
4;2. Comparative analyses of the two narrative genres using a variety of language
and storybook structure parameters revealed that both groups of children used
more characteristics of written language in the emergent storybook readings than
in the oral narratives, demonstrating that they were sensitive to genre
difference. The children with language impairment were less able than children
developing typically to produce language features associated with written
language. For both groups, middles and ends of stories were marked significantly
more often within the oral narratives than the emergent readings. The children
with language impairment also had difficulty with other linguistic features: less
frequent use of past-tense verbs in both contexts and the use of personal
pronouns in the oral narratives. Emergent storybook reading may be a useful
addition to language sampling protocols because it can reveal higher order
language skills and contribute to understanding the relationship between language
impairment and later reading disability.
PMID- 10668652
TI - The role of phonological opacity in reading achievement.
AB - This study investigated the relation among phonological awareness, morphological
awareness, and reading achievement in 69 children with and without language
learning disabilities. Children participated in two morphological tasks that
assessed skill in identifying the bases and suffixes of phonologically
transparent and opaque derivatives. Transparent derivatives preserve the
phonological characteristics of the base word (e.g., allow-allowable, pure
purist); opaque derivatives involve stress and/or vowel changes to the base
(e.g., acid-acidic, flame-flammable). Children with language-learning
disabilities were outperformed by chronological-age peers on each task and showed
a level of accuracy similar to that of younger, typically achieving children.
Regression analyses were used to determine the proportion of variance in reading
accounted for by the morphological tasks beyond that accounted for by age and
vocabulary knowledge. Performance with transparent derivatives added a
significant, but small, proportion (6.9%) to total variance in word
identification scores and a nonsignificant proportion (2.2%) to passage
comprehension scores. Performance with opaque derivatives added a substantial
contribution to word-identification scores (19.9%) and passage-comprehension
scores (16.5%) beyond that accounted for by age, vocabulary knowledge, and
performance with transparent derivatives. These results suggest that the ability
to analyze phonological changes associated with derivation may mediate much of
the link between the type of morphological awareness assessed here and reading
achievement.
PMID- 10668653
TI - Mechanisms of discourse comprehension impairment after right hemisphere brain
damage: suppression in lexical ambiguity resolution.
AB - Normal comprehension skill is linked with the proficiency of a suppression
mechanism, which functions to dampen mental activation that becomes irrelevant or
inappropriate to a final interpretation. This study investigated suppression and
discourse comprehension in adults with right brain damage (RBD). To index
suppression function, 40 adults with RBD and 40 without brain damage listened to
sentence stimuli that biased the meaning of a sentence-final lexical ambiguity
(e.g., SPADE), then judged whether a probe word (e.g., CARDS) fit the overall
sentence meaning. Probes represented the contextually inappropriate meanings of
the ambiguities and were presented in two conditions: 175 ms and 1000 ms post
stimulus. The same probes were used with unambiguous comparison stimuli. Probe
judgment response times indicated that only the group without brain damage
suppressed inappropriate interpretations over time. In a multiple regression
analysis, suppression function added significantly to predicting performance on a
general measure of narrative discourse comprehension for participants with RBD.
The discussion addresses how suppression deficits may account more broadly for
comprehension difficulties after RBD; it also considers several unresolved issues
concerning the suppression construct and the suppression deficit hypothesis.
PMID- 10668654
TI - Risk for speech disorder associated with early recurrent otitis media with
effusion: two retrospective studies.
AB - The goals of this two-part series on children with histories of early recurrent
otitis media with effusion (OME) were to assess the risk for speech disorder with
and without hearing loss and to develop a preliminary descriptive-explanatory
model for the findings. Recently available speech analysis programs, lifespan
reference data, and statistical techniques were implemented with three cohorts of
children with OME and their controls originally assessed in the 1980s: 35
typically developing 3-year-old children followed since infancy in a university
affiliated pediatrics clinic, 50 typically developing children of Native American
background followed since infancy in a tribal health clinic, and (in the second
paper) 70 children followed prospectively from 2 months of age to 3 years of age
and older. Dependent variables included information from a suite of 10 metrics of
speech production (Shriberg, Austin, Lewis, McSweeny, & Wilson, 1997a, 1 997b).
Constraints on available sociodemographic and hearing status information limit
generalizations from the comparative findings for each database, particularly
data from the two retrospective studies. The present paper reports findings from
risk analysis of conversational speech data from the first two cohorts, each of
which included retrospective study of children for whom data on hearing loss were
not available. Early recurrent OME was not associated with increased risk for
speech disorder in the pediatrics sample but was associated with approximately
4.6 (CI = 1.10-20.20) increased risk for subclinical or clinical speech disorder
in the children of Native American background. Discussion underscores the
appropriateness of multifactorial risk models for this subtype of child speech
disorder.
PMID- 10668656
TI - Observed and reported expressive vocabulary and word combinations in bilingual
toddlers.
AB - The consistency of parental reports of expressive vocabulary and word
combinations with observed expressive language among 21- to 27-month-old children
exposed to English and Spanish on a regular basis was the focus of this
investigation. Parental reports were obtained using the Spanish-English
Vocabulary Checklist (Patterson, 1998), an adaptation of the Language Development
Survey (Rescorla, 1989). The number of different words parents reported was
correlated (r = .66) with the number of different words the children used during
a 30-min videotaped interaction with the reporting parent. Parental reports of
whether the child was combining words and estimates of proportion of the child's
use of Spanish and English also were consistent with the children's language use
during the 30-min language samples.
PMID- 10668655
TI - Otitis media, fluctuant hearing loss, and speech-language outcomes: a preliminary
structural equation model.
AB - The goals of this study were to estimate the risk for lowered speech-language
outcomes associated with early recurrent otitis media with effusion (OME) with
and without hearing loss and to develop a preliminary descriptive-explanatory
model for the findings. Three statistical approaches were used to assess
associations among OME, hearing loss, and speech-language outcomes. Participants
were a subsample of 70 children followed prospectively in the Dallas Cooperative
Project on Early Hearing and Language Development (Friel-Patti & Finitzo, 1990).
Findings indicated that hearing levels at 12-18 months were significantly
associated with speech delay and low language outcomes at 3 years of age. The
risk for subclinical or clinical speech delay at 3 years of age was 2% for
children with less than 20 dB average hearing levels at 12-18 months and 33% for
children with greater than 20 dB average hearing levels at 12-18 months. A
structural equation model (Joreskog & Sorbom, 1993) indicated that the
significant and substantial effects of hearing levels at 12-18 months on speech
status at 3 years were significantly mediated by language status at 3 years.
Discussion includes implications of these findings for alternative speech
perception models linking early OME and hearing loss to later speech-language
disorder.
PMID- 10668657
TI - Adults' perception and production of the English vowel /i/.
AB - This study investigated the link between the perception and production of the
English vowel /i/ by adult native speakers of English. Participants first
produced the vowel /i/ using normal (citation) and careful (hyperarticulated)
speech, then completed a method of adjustment task in which they selected their
ideal exemplar of /i/. In this perceptual task, 24 of 35 participants had a
prototype; the remaining 11 did not, but were retained for comparison. In keeping
with the hyperspace effect (K. Johnson, E. Flemming, & R. Wright, 1993), all
participants selected perceptual stimuli with F1 and F2 values that were more
extreme (i.e., higher and further forward in the vowel space) than those of their
normal, citation productions. An analysis of front-back and high-low qualities
for the perceptual and production data in Euclidian space revealed that
hyperarticulated speech was closer to the perceptual data than citation speech
was, but only for participants with relatively clear-cut prototypes. The basis
for such individual variation in perception-production links is discussed.
PMID- 10668658
TI - Children's phoneme identification in reverberation and noise.
AB - This study assessed the effects of reverberation, noise, and their combination on
listeners' identification of consonants and vowels in naturally produced nonsense
syllables presented at different sensation levels (re: speech recognition
threshold). A secondary purpose of this study was to assess listeners'
identification of voicing, manner, and place of articulation for consonants at 50
dB SL in the reverberation, noise, and combined conditions. Listeners, aged 6-30
years, identified consonant-vowel-consonant-vowel (CVCV) stimuli presented at
four different sensation levels (re: speech recognition threshold) of 30, 40, 50,
and 60 dB SL in 4 listening conditions: (a) an optimal listening situation (no
reverberation, no noise), (b) reverberation only (1.3 seconds), (c) noise only
(+13 dB S/N against a multitalker babble), and (d) reverberation plus noise.
Results showed that all listener groups achieved maximum consonant identification
performance at 50 dB SL. Vowel identification scores were unaffected by SL.
Statistical analyses revealed that children's ability to identify consonants
varied according to listening condition. For example, children's consonant
identification abilities reached adult-like levels of performance at about age 14
years in the reverberation-only and noise-only listening conditions. However, in
the reverberation-plus-noise listening condition, children's consonant
identification abilities do not mature until the late teenage years. The ability
to identify vowels, on the other hand, develops much earlier. A feature analysis
of the consonant data showed that for all 3 features (voicing, manner, and
place), identification scores were highest in the control condition, similar for
the reverberation-only and noise-only conditions, and lowest in the reverberation
plus-noise condition. Voicing was easier for listeners to identify than manner or
place of articulation features in reverberation and noise. Taken together, these
results suggest that the ability to identify speech in reverberation and noise
reaches adult-like level of performance at different ages for different
components of the speech signal.
PMID- 10668659
TI - Effects of facial paralysis and audiovisual information on stop place
identification.
AB - This study investigated how listeners' perceptions of bilabial and lingua
alveolar voiced stops in auditory (A) and audiovisual (AV) presentation modes
were influenced by articulatory function in a girl with bilateral facial
paralysis (BFP) and a girl with normal facial movement (NFM). The Fuzzy Logic
Model of Perception (FLMP) was used to make predictions about listeners'
identifications of stop place based on assumptions about the nature (clear,
ambiguous, or conflicting) of the A or AV cues produced by each child during /b/
and /d/ CV syllables. As predicted, (a) listeners' identification scores for NFM
were very high and reliable, regardless of presentation mode or stop place, (b)
listeners' identification scores for BFP were high for lingua-alveolar place,
regardless of presentation mode, but more variable and less reliable than for
NFM; significantly lower (overall at a chance level) for bilabial place in the A
mode; and lowest for bilabial place in the AV mode. Conflicting visual cues for
stop place for BFP's productions of /bV/ syllables influenced listeners'
perceptions, resulting in most of her bilabial syllables being misidentified in
the AV mode. F2 locus equations for each child's /bV/ and /dV/ syllables showed
patterns similar to those reported by previous investigators, but with less
differentiation between stop place for BFP than NFM. These acoustic results
corresponded to the perceptual results obtained. (That is, when presented with
only auditory information, on average, listeners perceived BFP's target /b/
syllables to be near the boundary between /b/ and /d/.)
PMID- 10668660
TI - The use of tactile supplements in lipreading Swedish and English: a single
subject study.
AB - The speech perception skills of GS, a Swedish adult deaf man who has used a
"natural" tactile supplement to lipreading for over 45 years, were tested in two
languages: Swedish and English. Two different tactile supplements to lipreading
were investigated. In the first,"Tactiling," GS detected the vibrations
accompanying speech by placing his thumb directly on the speaker's throat. In the
second, a simple tactile aid consisting of a throat microphone, amplifier, and a
hand-held bone vibrator was used. Both supplements led to improved lipreading of
materials ranging in complexity from consonants in [aCa] nonsense syllables to
Speech Tracking. Analysis of GS's results indicated that the tactile signal
assisted him in identifying vowel duration, consonant voicing, and some manner of
articulation categories. GS's tracking rate in Swedish was around 40 words per
minute when the materials were presented via lipreading alone. When the
lipreading signal was supplemented by tactile cues, his tracking rates were in
the range of 60-65 words per minute. Although GS's tracking rates for English
materials were around half those achieved in Swedish, his performance showed a
similar pattern in that the use of tactile cues led to improvements of around 40%
over lipreading alone.
PMID- 10668661
TI - Validation assessment of a French version of the tinnitus reaction questionnaire:
a comparison between data from English and French versions.
AB - The present study compares the results obtained on original and French versions
of the TRQ (Tinnitus Reaction Questionnaire) initially published by Wilson,
Henry, Bowen, and Haralambous (1991) in English to evaluate the psychological
distress of tinnitus sufferers. Reliability and validity of the French
translation were determined using data from 173 normal hearing or hearing
impaired patients with tinnitus lasting from 1 month to 41 years. They completed
the translated questionnaire and a short version of the Minnesota Multiphasic
Personality Inventory. The results indicated good internal consistency
(Cronbach's alpha = .94), and the reliability of the French version of the TRQ
was demonstrated, except for items 5 and 20. High statistically significant
correlations were found between the TRQ and Depression, Psychaesthenia, and
Anxiety Mini-Mult subscales. The validation demonstrates only minor effects of
language. The French version of the TRQ thus is an equally valid tool as the
original English version for evaluating tinnitus distress of a patient.
PMID- 10668662
TI - Acoustic and airflow spectral analysis of voice tremor.
AB - Acoustic spectral analysis has been used to describe voice tremor with some
success, but no feature distinguishing pathological from normal tremor has been
clearly identified. To assist in monitoring voice tremor associated with
neurological diseases, objective and quantifiable measures that can distinguish
between normal and pathological tremor are desired. This study explored the
plausibility of using airflow and acoustic signals to quantify the frequency and
amplitude of voice tremor and potentially to distinguish pathological from normal
tremor. Subjects were 10 individuals with pathological tremor, most of them
individuals with Parkinson's disease, and 10 gender and age-matched individuals
with no voice disorder. Simultaneous acoustic and airflow signals were recorded
during sustained vowel phonation. The acoustic intensity contours and the airflow
signals were submitted to spectral analysis. A peak prominence ratio, defined as
the ratio of the spectral peak energy to the overall signal energy, was
calculated for each spectral peak below 30 Hz. For each subject, the 6 spectral
peaks with the highest peak prominence ratios were selected. Frequency values of
the 6 selected acoustic or airflow spectral peaks failed to distinguish tremor
group from control group. Peak prominence ratios of the 6 selected acoustic
spectral peaks were significantly higher for tremor group than for control group.
Although spectral analysis of airflow signals was not useful in differentiating
tremor group from control group, acoustic intensity contours and airflow time
waveforms were highly and positively correlated in more tremor subjects (90%)
than control subjects (40%). This finding suggests that the relationship between
acoustic intensity contours and airflow time waveforms may reflect the presence
and the source of voice tremor.
PMID- 10668663
TI - Patterns of orofacial movement velocity across variations in speech rate.
AB - To understand the clinical aspects of speech rate control, a clearer picture is
needed of how orofacial structures are coordinated across variations in speech
rate. To address this problem, patterns of orofacial tangential velocity or speed
were analyzed in a group of 9 normal speakers as they produced the utterance "a
bad daba" at fast, normal, and slow speech rates. An electromagnetic system was
used to record the movements of the upper lip, lower lip, jaw, and tongue.
Measures of the magnitude of peak tangential velocities were obtained across the
four structures. Orofacial velocities consistently decreased at slow rates
relative to normal rates, whereas at fast rates increased and decreased
velocities were observed in an equivalent number of cases. Significant
correlations frequently were obtained across speech rate between lip, tongue, and
jaw velocities. Upper and lower lip velocities showed consistent positive
correlations with one another, whereas marked intersubject differences were
observed in the sign of jaw-related correlations. Repeated testing on 3 subjects
indicated a high degree of consistency within subjects in the overall patterns of
mean velocity for the different structures. Results are discussed in relation to
possible motor control differences underlying fast and slow speech, neural
coupling of muscle systems, and jaw-related individual differences in speech
motor coordination.
PMID- 10668664
TI - Frequency and temporal resolution in elderly listeners with good and poor word
recognition.
AB - There is a subgroup of elderly listeners with hearing loss who can be
characterized by exceptionally poor speech understanding. This study examined the
hypothesis that the poor speech-understanding performance of some elderly
listeners is associated with disproportionate deficits in temporal resolution and
frequency resolution, especially for complex signals. Temporal resolution, as
measured by gap detection, and frequency resolution, as measured by the critical
ratio, were examined in older listeners with normal hearing, older listeners with
hearing loss and good speech-recognition performance, and older listeners with
hearing loss and poor speech-recognition performance. Listener performance was
evaluated for simple and complex stimuli and for tasks of added complexity. In
addition, syllable recognition was assessed in quiet and noise. The principal
findings were that older listeners with hearing loss and poor word-recognition
performance did not perform differently from older listeners with hearing loss
and good word recognition on the temporal resolution measures nor on the spectral
resolution measures for relatively simple stimuli. However, frequency resolution
was compromised for listeners with poor word-recognition abilities when targets
were presented in the context of complex signals. Group differences observed for
syllable recognition in quiet were eliminated in the noise condition. Taken
together, the findings support the hypothesis that unusual deficits in word
recognition performance among elderly listeners were associated with poor
spectral resolution for complex signals.
PMID- 10668665
TI - Supraglottic activity: evidence of vocal hyperfunction or laryngeal articulation?
AB - False vocal fold (FVF) adduction and compression of the arytenoid cartilages to
the petiole of the epiglottis in an anterior to posterior (A-P) direction have
been thought to characterize voice disorders with abnormally increased muscle
tension or effort, often termed hyperfunctional voice disorders. To further
evaluate the association between hyperfunctional voice disorders and supraglottic
activity, we compared the incidence of static and dynamic supraglottic activity
in individuals with normal laryngeal mucosa, normal voice quality, and no voice
complaints to two populations: subjects with vocal fold nodules and subjects with
complaints of dysphonia without visible vocal fold lesions, glottal incompetence,
or impairment of arytenoid cartilage motion ("hyperfunctional" group). Thirty-two
subjects were assigned to one of these three groups (10 control, 12 nodule, and
10 hyperfunctional). Laryngeal movements were recorded using flexible
videoendoscopy while a subject was performing speech tasks such as sustained
phonation, syllable repetitions, sentence imitations, and conversation. Samples
were randomized by subject and task and rated for presence or absence of A-P and
FVF compression. Statistically significant group differences were found for FVF
compression across speech tasks (chi-square, p<0.001). The control group had the
smallest incidence (45%), nodule patients the next larger incidence (68%), and
hyperfunctional patients the largest incidence (80%). Statistically significant
group differences were found for A-P compression across speech tasks (chi-square,
p<.05). The control group had the smallest incidence (74%), nodule patients the
next larger incidence (78%), and hyperfunctional patients the largest incidence
(92%). Statistically significant task differences were found for the presence of
FVF compression in control subjects (chi-square, p<.005), hyperfunctional
patients (chi-square, p<.025), and nodule patients (chi-square, p<.001), but not
for A-P compression for any of the groups. A higher incidence of FVF compression
was present for the speech tasks that included glottal stops. This context
specific variation in supraglottic activity suggested a dynamic component to FVF
compression and also explained the high proportion of FVF compression in the
control group. Each video sample was also rated for consistency of FVF or A-P
compression to explore the static and dynamic nature of supraglottic activity.
For samples on which raters agreed, A-P compression was typically present
consistently, suggesting a static component, and FVF compression inconsistently,
suggesting a dynamic component, for all three groups (chi-square, p<.001). These
findings do not support previous suggestions that supraglottic activity may be a
precursor to developing vocal fold nodules, as the nodule patients did not
exhibit a higher incidence or consistency of A-P or FVF compression than patients
with hyperfunctional voicing patterns in this study. Subjects in the
hyperfunctional voice group were found to have static components of FVF and A-P
compression. The presence of FVF compression in speech tasks that included
glottal stops in the control group suggests an articulatory function at the
laryngeal level.
PMID- 10668667
TI - Strength, endurance, and stability of the tongue and hand in Parkinson disease.
AB - Weakness and fatigue in the orofacial system often are presumed to contribute to
the dysarthria associated with neuromotor disorders, although previous research
findings are equivocal. In this study, tongue strength, endurance, and stability
during a sustained submaximal effort were assessed in 16 persons with mild to
severe Parkinson disease (PD) and a perceptible speech disorder. The same
measures were taken from one hand for comparison. Only tongue endurance was found
to be significantly lower in these participants than in neurologically normal
control participants matched for sex, age, weight, and height. Analyses of data
from a larger sample comprising the present and retrospective data revealed lower
than-normal tongue strength and endurance in participants with PD. No significant
correlations were found between tongue strength and endurance, interpause speech
rate, articulatory precision, and overall speech defectiveness for the present
and previously studied participants with PD, bringing into question the influence
of modest degrees of tongue weakness and fatigue on perceptible speech deficits.
PMID- 10668666
TI - The physiologic development of speech motor control: lip and jaw coordination.
AB - This investigation was designed to describe the development of lip and jaw
coordination during speech and to evaluate the potential influence of speech
motor development on phonologic development. Productions of syllables containing
bilabial consonants were observed from speakers in four age groups (i.e., 1-year
olds, 2-year-olds, 6-year-olds, and young adults). A video-based movement
tracking system was used to transduce movement of the upper lip, lower lip, and
jaw. The coordinative organization of these articulatory gestures was shown to
change dramatically during the first several years of life and to continue to
undergo refinement past age 6. The present results are consistent with three
primary phases in the development of lip and jaw coordination for speech:
integration, differentiation, and refinement. Each of these developmental
processes entails the existence of distinct coordinative constraints on early
articulatory movement. It is suggested that these constraints will have
predictable consequences for the sequence of phonologic development.
PMID- 10668668
TI - Short-latency changes in voice F0 and neck surface EMG induced by mechanical
perturbations of the larynx during sustained vowel phonation.
AB - Nineteen healthy young adult males with normal voice and speech attempted to
sustain the vowel /u/ at a constant pitch (target: 180 Hz) and a constant and
comfortable loudness level while receiving a sudden mechanical perturbation to
the larynx (thyroid prominence) via a servo-controlled probe. The probe moved
toward or away from the larynx in a ramp-and-hold fashion (3.3-mm displacement,
0.7 N force, 20-ms rise time, 250-ms duration) as the subjects attempted to
maintain a constant probe-larynx pressure. Eighty stimuli were applied in each
direction, one stimulus per phonation. Pairs of surface electromyography (EMG)
electrodes were attached to the skin of the anterior neck over laryngeal,
infralaryngeal, and supralaryngeal areas. The rectified EMG signals, the voltage
analog of the voice fundamental frequency (VAF0), and the voltage analog of the
probe displacement were digitized and signal-averaged relative to the onset of
the stimulus. Sudden perturbation of the larynx induced an instantaneous decrease
or increase in VAF0, depending on the direction of the probe's movement, and a
short-latency increase in the EMG (30-35 ms) and VAF0 (55-65 ms). We argue that
the instantaneous VAF0 change was related to a mechanical effect, and the short
latency VAF0 and EMG changes to reflexogenic effects-the latter most likely
associated with both intrinsic and extrinsic laryngeal sensorimotor mechanisms.
Further physiological studies are needed to elucidate the sources of the VAF0 and
EMG responses. Once elucidated, the present method may provide a powerful
noninvasive tool for studying laryngeal neurophysiology. The theoretical and
clinical implications of the present findings are addressed.
PMID- 10668669
TI - On the assessment of stability and patterning of speech movements.
AB - Speech requires the control of complex movements of orofacial structures to
produce dynamic variations in the vocal tract transfer function. The nature of
the underlying motor control processes has traditionally been investigated by
employing measures of articulatory movements, including movement amplitude,
velocity, and duration, at selected points in time. An alternative approach,
first used in the study of limb motion, is to examine the entire movement
trajectory over time. A new approach to speech movement trajectory analysis was
introduced in earlier work from this laboratory. In this method, trajectories
from multiple movement sequences are time- and amplitude-normalized, and the STI
(spatiotemporal index) is computed to capture the degree of convergence of a set
of trajectories onto a single, underlying movement template. This research note
describes the rationale for this analysis and provides a detailed description of
the signal processing involved. Alternative interpolation procedures for time
normalization of kinematic data are also considered.
PMID- 10668670
TI - Otologic and audiologic evaluation of human immunodeficiency virus-infected
patients.
AB - PURPOSE: To quantify the incidence of ear disease in patients infected with human
immunodeficiency virus (HIV). MATERIALS AND METHODS: This is a descriptive case
series of HIV-positive patients, with data collected using an otologic
questionnaire. otologic examination, audiologic evaluation, and chart review. The
study was performed at an urban University Hospital's outpatient Infectious
Disease and Otolaryngology clinics. A consecutive sample of 50 HIV-infected
patients volunteered for this study. Ten subjects refused. Almost all patients
received public assistance for medical care. Descriptive results were tabulated.
Audiometric data were analyzed for ear, Centers for Disease Control (CDC) group,
otologic complaint, and age effects. Data were compared with established norms.
RESULTS: Twenty-three men and 27 women with a mean age of 40 years and mean
duration of HIV disease of 3.5 years were studied. Eighteen percent of patients
were in category CDC-A, 38% in CDC-B, and 44% in CDC-C. Otologic complaints were
more prevalent than expected: 34% of patients reported aural fullness, 32%
dizziness, 29% hearing loss, 26% tinnitus, 23% otalgia, and 5% otorrhea. Results
of the neuro-otologic examination were abnormal in 33%. Tympanometric examination
was abnormal in 21%. A significant degree of high-frequency sensorineural hearing
loss was observed. CDC-B and CDC-C patients had worse hearing than CDC-A patients
at 3 frequencies. Patients who complained of hearing loss had significantly worse
otoacoustic emission results and hearing results than patients who did not, at
all frequencies except 1,000 Hz. Patients in their 30s had better hearing in the
speech frequencies than did all other patients. CONCLUSIONS: Ear disease affects
up to 33% of HIV-infected patients. Otitis media is a frequent finding.
Sensorineural hearing loss is more severe in patients with more severe HIV
infection. Patients with ear complaints have demonstrable otopathology.
Continuation of this preliminary descriptive work is necessary.
PMID- 10668671
TI - Head and neck manifestations of non-Hodgkin's lymphoma in human immunodeficiency
virus-infected patients.
AB - PURPOSE: Non-Hodgkin's lymphoma is the 2nd most common malignancy in human
immunodeficiency virus (HIV)-infected patients. However, limited information
regarding head and neck manifestations of non-Hodgkin's lymphoma is present in
the literature. The aim of this article is to describe the head and neck
manifestations of non-Hodgkin's lymphoma in HIV-infected patients and compare it
with that seen in noninfected patients. PATIENTS AND METHODS: A case-control
study was performed including 124 patients with non-Hodgkin's lymphoma presenting
over a 5.5-year period to tertiary care center in a metropolitan location.
RESULTS: Overall, the anatomic distribution of non-Hodgkin's lymphoma is not
altered in the presence of HIV infection with the head and neck region (63%) most
often involved overall. However, within the head and neck region, extralymphatic
disease is significantly more common in HIV-infected patients (59%) than
noninfected patients (33%; P = .001). Central nervous system (CNS) involvement
accounts for 41% of head and neck non-Hodgkin's lymphoma in HIV-infected
patients, in contrast to only 12% of noninfected patients. High-grade lymphoma
(68%) are more common than intermediate (30%) or low-grade disease (2%) in the
HIV-infected population, whereas low (24%) and intermediate (60%) grades are more
common than high-grade lymphoma (16%) in noninfected patients (P < .001). The
large cell immunoblastic type (48%) is the most common subtype in HIV-infected
patients, whereas diffuse large-cell type (32%) was most common in HIV-negative
patients (P < .05). Survival is significantly poor for HIV-infected patients (P <
.05). The impact of HIV infection on survival remain significant even after
controlling for the effects of confounding factors. CONCLUSIONS: Head and neck
involvement with non-Hodgkin's lymphoma occurs in a significant number of HIV
infected patients. Our data show that the distribution and course of non
Hodgkin's lymphoma is unique in HIV-infected patients. A high level of suspicion
for non-Hodgkin's lymphoma is required in all cases of head and neck lesions in
patients with HIV infection to facilitate management.
PMID- 10668672
TI - Laryngeal long-term morbidity after supraglottic laryngectomy and postoperative
radiation therapy.
AB - PURPOSE: This study was performed to investigate factors associated with
laryngeal morbidity when postoperative radiation therapy (RT) is added to
supraglottic laryngectomy. MATERIALS AND METHODS: From 1980 to 1994, 56 patients
affected with T1 to 4 N0 to 2c supraglottic squamous cell carcinoma selected for
standard (59%) or extended (41%) supraglottic laryngectomy at 2 different
institutions were retrospectively analyzed. Most of the patients (91%) also
underwent neck dissection. Approximately 80% of the patients had stage T4 primary
lesions or N2 neck disease. Postoperative RT was added for presumed microscopic
disease at the primary site (13 patients), regional nodes (23 patients), or both
(20 patients). Median delivered doses to the larynx and to the neck were 50 Gy
(range, 40 to 64 Gy) and 46 Gy (range, 40 to 64 Gy), respectively. Median follow
up for living patients is 11 years (range, 2.8 to 16.9 years). Laryngeal
complication was defined as the appearance of grade 2 or higher toxicity
according to the European Organization for Research and Treatment of Cancer
(EORTC) and the Radiation Therapy Oncology Group (RTOG) scoring systems. RESULTS:
Two- and 5-year actuarial locoregional control rates were 85+/-5% and 83+/-5%,
respectively. Thirty patients (54%) developed laryngeal complications. However,
just one patient experienced grade 4 laryngeal oedema requiring permanent
tracheostomy. Estimated actuarial survival without laryngeal complications were
50+/-7%, 43+/-7%, and 39+/-7% at 2, 5, and 10 years, respectively. At univariate
analysis, treated volumes (P = .03) and total dose to the larynx (P = .03) were
significantly associated with local toxicity. A trend was observed also for the
maximum dose to the neck (P = .06) and dose per fraction (P = .09). A
multivariate Cox proportional hazards model showed total dose to the larynx to be
the only independent predictor of toxicity (P = .03). The hazard ratio of
laryngeal toxicity was 2.2 (95% confidence interval: 1.1/4.6), for a total dose
to the larynx greater than 50 Gy. CONCLUSION: After supraglottic laryngectomy,
postoperative RT to the neck does not affect local morbidity, but careful RT
treatment planning is necessary to avoid delivering a total dose to the larynx
greater than 50 Gy.
PMID- 10668673
TI - Management of congenital laryngeal malformations.
AB - Congenital malformations of the larynx are relatively rare but may be life
threatening. The most common causes include laryngomalacia, vocal cord paralysis,
and subglottic stenosis. The last 20 years has seen major advances in the field
of surgical correction of such anomalies also serving to reduce the number of
tracheotomies in children and the inherent dangers they pose. Success rates for
the most popular surgical procedures have been favorable. These include
supraglottoplasty for cases of severe laryngomalacia, in which relief of
respiratory symptoms has been shown to occur in excess of 80% of cases.
Complication rate is low, although postoperative death has been reported. Failure
usually occurs in patients with concomitant airway abnormalities including
pharyngomalacia. Vocal cord lateralization for vocal cord paralysis with airway
compromise is achieved by means of arytenoidopexy or arytenoidectomy, using the
lateral approach. Arytenoidectomy also can be performed using laryngofissure or
endoscopic laser excision. Subglottic stenosis is the 3rd most common congenital
anomaly. Anterior or multiple cricoid splitting with cartilage graft
interpositioning is usually performed. The success rates for these procedures has
been shown to be approximately 90%.
PMID- 10668674
TI - Rationale for elective neck dissection.
PMID- 10668675
TI - Coil embolization of a ruptured carotid pseudoaneurysm presenting as epistaxis-
pediatric otolaryngology: principles and practice.
PMID- 10668676
TI - Nonadjacent mass compression dizziness and hearing loss: a case report.
PMID- 10668677
TI - Congenital malformations of middle and inner ears of parabiotic twins.
AB - We describe herein the congenital malformations of the middle and inner ears in
temporal bones of parabiotic, monozygotic twins. Temporal bones were removed from
twin B, who had no fetal cardiac activity and was born dead at 23-4/7 weeks, and
twin A, the donor or "pump" twin in intrauterine life, who died shortly after
birth at 20-6/7 weeks. The temporal bones were processed routinely in celoidin,
stained with hematoxylin and eosin, and examined by light microscopy. We found
that twin B had Mondini's dysplasia with associated deformities of the middle ear
and in general showed more developmental anomalies than twin A, and we conclude
that Mondini's dysplasia with anomalies of the middle ear may occur in the
parabiotic twin syndrome, and the abnormalities may be explainable as the result
of vascular disturbance, which also causes other lesions in these unusual cases.
PMID- 10668678
TI - Management of aberrant internal carotid artery injuries in children.
PMID- 10668679
TI - Dermoid cysts of floor of the mouth: report of four cases.
PMID- 10668680
TI - Ancient cervical vagal neurilemmoma: a case report.
PMID- 10668681
TI - Chorda tympani neuroma: diagnosis and management.
PMID- 10668682
TI - Fair winds and foul headaches: risk factors and triggers of migraine.
PMID- 10668683
TI - The ketogenic diet: a therapy in search of an explanation.
PMID- 10668684
TI - Of mice and men: a model of HIV encephalitis.
PMID- 10668685
TI - Stroke in patients with heart failure and reduced left ventricular ejection
fraction.
AB - BACKGROUND: Cardiac failure is associated with both stroke of presumed
cardioembolic origin and a high mortality rate. Warfarin is used frequently in
patients with reduced cardiac left ventricular ejection fraction (EF), although
no randomized trials have confirmed that anticoagulation benefits these patients.
METHODS: A literature review was performed pertaining to the frequency of stroke
and mortality, and the effect of antithrombotic agents on stroke and mortality
rates, in patients with cardiac failure or reduced cardiac EF. We also reviewed
the main features of two new proposed studies (Warfarin and Antiplatelet Therapy
in Chronic Heart Failure [WATCH] and Warfarin Versus Aspirin in Reduced Cardiac
Ejection Fraction [WARCEF]) comparing warfarin and antiplatelet agents in
patients with low EF. RESULTS: The risk of stroke increases with decreasing EF
and the risk of mortality increases with the clinical severity of cardiac failure
(New York Heart Association class). Data from heart failure treatment studies
suggest that warfarin may reduce stroke and mortality in patients with reduced
EF, but definitive answers are lacking. The stroke rate alone is too low to be
used as a primary endpoint, but an endpoint combining stroke and death (as WARCEF
and WATCH propose) should allow an assessment of the effect of antithrombotics in
cardiac failure. Amalgamating the data on stroke from these two trials should
yield enough statistical power to compare the effects of warfarin and aspirin on
stroke as an independent secondary endpoint. CONCLUSION: Whether warfarin is
superior to aspirin in reducing stroke and mortality in patients with low
ejection fraction is an important clinical issue that warrants prospective
evaluation.
PMID- 10668686
TI - Estrogen for Alzheimer's disease in women: randomized, double-blind, placebo
controlled trial.
AB - BACKGROUND: AD, the most prevalent cause of dementia, affects twice as many women
as men. Therapeutic options are limited, but results of prior studies support the
hypothesis that estrogen treatment may improve symptoms of women with this
disorder. METHODS: Forty-two women with mild-to-moderate dementia due to AD were
enrolled into a randomized, double-blind, placebo-controlled, parallel-group
trial of unopposed conjugated equine estrogens (1.25 mg/day) for 16 weeks.
RESULTS: Outcome data were available for 40 women at 4 weeks and 36 women at 16
weeks. At both 4 and 16 weeks, there were no significant differences or
statistical trends between treatment groups on the primary outcome measure (the
cognitive subscale of the Alzheimer's Disease Assessment Scale), clinician-rated
global impression of change, or caregiver-rated functional status. Exploratory
analyses of mood and specific aspects of cognitive performance also failed to
demonstrate substantial group differences. CONCLUSION: Although conclusions are
limited by small sample size and the possibility of a type II error, results
suggest that short-term estrogen therapy does not improve symptoms of most women
with AD. These findings do not address possible long-term effects of estrogen in
AD, possible interactions between estrogen and other treatment modalities, or
putative effects of estrogen in preventing or delaying onset of this disorder.
PMID- 10668687
TI - Chinook winds and migraine headache.
AB - OBJECTIVE: To determine the effects of chinook weather conditions on probability
of migraine headache onset. BACKGROUND: Many migraineurs believe weather to be a
trigger factor for their headaches; however, there is little supportive evidence
in the literature. Migraineurs in the southern part of the Canadian province of
Alberta frequently report that chinooks, warm westerly winds specific to the
region, trigger their headaches. METHOD: Weather data from Environment Canada
were used to designate each calendar day during the study period as a chinook,
prechinook, or nonchinook day. Headache data were collected from 75 patient
diaries from the University of Calgary Headache Research Clinic. Individual and
multiple logistic regression models were used to determine if the weather
conditions affected the probability of migraine onset. RESULTS: The probability
of migraine onset was increased on both prechinook days (odds ratio 1.24; 95% CI
1.08 to 1.42) and on days with chinook winds (1.19; 1.02 to 1.39) compared with
nonchinook days. Analysis of chinook wind velocities revealed that for chinook
days, the relative risk of migraine onset was increased only on high-wind chinook
days (velocity > 38 km/h) (odds ratio 1.41; 95% CI 1.06 to 1.88). A subset of
individuals was sensitive to high-wind chinook days, and another subset was only
sensitive to prechinook days. Only two patients were sensitive to both weather
conditions, and the majority of patients was not sensitive to either. Neither
weather condition had a protective effect. Increasing age was associated with
high-wind chinook sensitivity (p = 0.009) but not prechinook sensitivity (p =
0.389). CONCLUSIONS: Both prechinook and high-wind chinook days increase the
probability of migraine onset in a subset of migraineurs. Because few subjects
were found to be sensitive to both weather types, the mechanisms for these
weather effects may be independent. This is supported by the presence of an age
interaction for high-wind chinook days but not for prechinooks day.
PMID- 10668688
TI - Headache and major depression: is the association specific to migraine?
AB - OBJECTIVE: To examine the relationship between migraine and major depression, by
estimating the risk for first-onset major depression associated with prior
migraine and the risk for first migraine associated with prior major depression.
We also examined the extent to which comorbidity with major depression is
specific to migraine or is observed in other severe headaches. METHODS:
Representative samples of persons 25 to 55 years of age with migraine or other
severe headaches (i.e., disabling headaches without migraine features) and
controls with no history of severe headaches were identified by a telephone
survey and later interviewed in person to ascertain history of common psychiatric
disorders. RESULTS: Lifetime prevalence of major depression was approximately
three times higher in persons with migraine and in persons with severe headaches
compared with controls. Significant bidirectional relationships were observed
between major depression and migraine, with migraine predicting first-onset
depression and depression predicting first-onset migraine. In contrast, persons
with severe headaches had a higher incidence of first-onset major depression
(hazard ratio = 3.6), but major depression did not predict a significantly
increased incidence of other severe headaches (hazard ratio = 1.6). CONCLUSIONS:
The contrasting results regarding the relationship of major depression with
migraine versus other severe headaches suggest that different causes may underlie
the co-occurrence of major depression in persons with migraine compared with
persons with other severe headaches.
PMID- 10668689
TI - Chronic daily headache in Chinese elderly: prevalence, risk factors, and biannual
follow-up.
AB - OBJECTIVE: To investigate the prevalence, risk factors, and prognosis of chronic
daily headache (CDH) in a population of elderly Chinese subjects. METHODS: A
community-based survey of registered residents > or =65 years old (n = 2,003) in
two townships of Kinmen Island in 1993. A neurologist used a structured
questionnaire and clinical interview to make the diagnosis of headache. Subjects
who had headaches > or =15 days/month for > or =6 months in the previous year
were considered to have CDH. CDH was further classified into chronic tension-type
headache (CTTH), CDH with migrainous features (CDH/MF), and other CDH. Person-to
person biannual follow-up of the subjects with CDH was done in June 1995 and
August 1997. RESULTS: A total of 1,533 people (77%) participated in our
prevalence study. Sixty subjects (3.9%) fulfilled the criteria for CDH, with a
higher prevalence in women (F/M: 5.6%/1.8%, p < 0.001). Of these subjects, 42
(70%) had CTTH, 15 (25%) had CDH/MF, and 3 (5%) had other CDH. Only 23% of those
with CDH had consulted physicians for their headaches in the previous year.
Multivariate logistic regression revealed the significant risk factors for CDH to
be analgesic overuse (OR = 79), a history of migraine (OR = 6.6), and a Geriatric
Depression Scale-Short Form score of > or =8 (OR = 2.6). The follow-up results in
1995 and 1997 showed that about two-thirds of the subjects still had CDH.
Analgesic overuse (relative risk = 1.6) in 1993 was a significant predictor of
persistent CDH at follow-up. CONCLUSIONS: A total of 3.9% of this elderly
population had CDH, with CTTH being the most common subtype. Almost two-thirds of
those with CDH had persistent frequent headaches at follow-up. Analgesic overuse
was a significant predictor of a poor outcome.
PMID- 10668690
TI - Idiopathic intracranial hypertension: relationship to depression, anxiety, and
quality of life.
AB - OBJECTIVE: To explore the incidence of depression and anxiety and to measure
quality of life in women with idiopathic intracranial hypertension (IIH), a
matched group cross-sectional study was conducted. Women with IIH (n = 28) were
compared with control groups of weight- and age-matched women not diagnosed with
IIH (n = 30) and with age-matched women of normal weight (n = 30). METHODS:
Eighty-eight women completed a questionnaire soliciting health information and
standardized questionnaires measuring depression, anxiety, and quality of life.
The groups were compared using analysis of variance and chi2 tests. Where
appropriate, post hoc comparisons were made using Fisher's test. RESULTS:
Patients with IIH reported a greater number of adverse health problems than
either of the control groups. Non-health-related psychosocial concerns were
equally prevalent among the three groups, but IIH patients were significantly
more affected by hardships associated with health problems than the other two
groups. The patient group also had higher levels of depression and anxiety than
the control groups. These adverse health conditions were reflected in decreased
quality of life measures for the IIH patients. CONCLUSIONS: This study supports
previous reports that link obesity and psychosocial difficulties, but obesity
alone is not the explanation for the higher levels of depression and lower levels
of quality of life.
PMID- 10668691
TI - Ketone bodies do not directly alter excitatory or inhibitory hippocampal synaptic
transmission.
AB - OBJECTIVE: To determine the effect of the ketone bodies beta-hydroxybutyrate
(betaHB) and acetoacetate (AA) on excitatory and inhibitory neurotransmission in
the mammalian CNS. BACKGROUND: The ketogenic diet is presumed to be an effective
anticonvulsant regimen for some children with medically intractable seizures.
However, its mechanism of action remains a mystery. According to one hypothesis,
ketone bodies have anticonvulsant properties. METHODS: The authors examined the
effect of betaHB and AA on excitatory and inhibitory synaptic transmission in rat
hippocampal-entorhinal cortex slices and cultured hippocampal neurons. In
cultured neurons, their effect was also directly assayed on postsynaptic receptor
properties. Finally, their ability to prevent spontaneous seizures was determined
in a hippocampal-entorhinal cortex slice model. RESULTS: betaHB and AA did not
alter synaptic transmission in these models. CONCLUSIONS: The anticonvulsant
properties of the ketogenic diet do not result from a direct effect of ketone
bodies on the primary voltage and ligand gated ion channels mediating excitatory
or inhibitory neurotransmission in the hippocampus.
PMID- 10668692
TI - 11C-flumazenil PET in patients with refractory temporal lobe epilepsy and normal
MRI.
AB - BACKGROUND: Using 11C-flumazenil (FMZ) PET with correction for partial-volume
effect, reductions of central benzodiazepine receptor (cBZR) binding can be
detected reliably in vivo on remaining neurons in sclerotic hippocampi of
patients with mesial temporal lobe epilepsy (TLE). OBJECTIVE: To delineate
abnormalities of 11C-FMZ binding in patients with medically refractory TLE and
normal quantitative MRI. METHODS: Analysis of parametric images of FMZ volume of
distribution (Vd) using two complementary approaches: 1) MRI-based volume of
interest (VOI) approach with partial volume effect correction for multiple
hippocampal and extrahippocampal VOIs; and 2) statistical parametric mapping
(SPM) to localize significant 11C-FMZ binding changes objectively on a voxel-by
voxel basis. RESULTS: Significant abnormalities of absolute FMZ-Vd were found
after partial volume effect correction in 5 of 10 patients: unilateral decrease
in the amygdala ipsilateral to the EEG focus (1), unilateral hippocampal
decreases and bilateral temporal and extratemporal neocortical decreases (2),
unilateral increase in the temporal neocortex together with extratemporal
neocortical increases (1), and bilateral posterior hippocampal increases together
with temporal neocortical increases (1). In the three patients with extratemporal
neocortical changes, the concomitant unilateral hippocampal or temporal
neocortical changes were contralateral to the presumed epileptic focus.
Significant asymmetries of FMZ-Vd between homologous regions were found in six
patients. In four of those patients, absolute FMZ-Vd for the homologous regions
were within normal limits, with two of the four patients showing relatively
higher hippocampal values ipsilateral to the presumed epileptic focus. SPM
analysis localized significant abnormalities of FMZ-Vd in similar locations in
three of the seven patients in whom VOI analysis detected significant changes. In
addition, SPM indicated significant unilateral contralateral hippocampal
decreases in an eighth patient. However, both methods failed to localize
epileptic foci in two patients identified by depth-EEG recordings. CONCLUSIONS:
11C-FMZ PET showed focal increases as well as decreases of FMZ binding in 80% of
patients with refractory TLE and normal high-quality MRI but was not consistently
helpful in localizing the epileptic foci.
PMID- 10668693
TI - Prevalence of nonconvulsive status epilepticus in comatose patients.
AB - BACKGROUND: Nonconvulsive status epilepticus (NCSE) is a form of status
epilepticus (SE) that is an often unrecognized cause of coma. OBJECTIVE: To
evaluate the presence of NCSE in comatose patients with no clinical signs of
seizure activity. METHODS: A total of 236 patients with coma and no overt
clinical seizure activity were monitored with EEG as part of their coma
evaluation. This study was conducted during our prospective evaluation of SE,
where it has been validated that we identify over 95% of all SE cases at the
Medical College of Virginia Hospitals. Only cases that were found to have no
clinical signs of SE were included in this study. RESULTS: EEG demonstrated that
8% of these patients met the criteria for the diagnosis of NCSE. The study
included an age range from 1 month to 87 years. CONCLUSION: This large-scale EEG
evaluation of comatose patients without clinical signs of seizure activity found
that NCSE is an underrecognized cause of coma, occurring in 8% of all comatose
patients without signs of seizure activity. EEG should be included in the routine
evaluation of comatose patients even if clinical seizure activity is not
apparent.
PMID- 10668694
TI - Discontinuation of antiepileptic drugs after successful epilepsy surgery.
AB - OBJECTIVE: To evaluate the frequency and risk factors for seizure recurrence
subsequent to antiepileptic drug (AED) withdrawal in patients who underwent
surgical treatment for intractable partial epilepsy and were rendered seizure
free. METHODS: The outcome of discontinuation of AED medication was studied
retrospectively in 210 consecutive patients who were rendered seizure-free after
epilepsy surgery performed between 1989 and 1993. RESULTS: Medical therapy was
reduced in 96 patients and discontinued in 84 patients. The seizure recurrence
rate after complete AED withdrawal was 14% and 36% at 2 and 5 years. In contrast,
only 3% and 7% of the 30 patients who did not alter AED treatment after surgery
had recurrent seizures in the same time intervals. After AED discontinuation,
seizures tended to recur more often in patients with normal preoperative MRI
studies compared with those with focal pathology. However, this difference did
not reach significance. Intraoperative electrocorticography, extent of surgical
resection, postoperative EEG, and seizure-free duration after surgery were not
predictive of seizure outcome after AED withdrawal. CONCLUSIONS: AED withdrawal
was associated with seizure recurrence in a significant portion of patients
rendered seizure-free by epilepsy surgery. Patients with a normal preoperative
MRI study showed a tendency for higher seizure recurrence, whereas the duration
of seizure-free postoperative AED treatment interval did not significantly
influence the seizure recurrence rate. These results will prove useful in
counseling patients about discontinuing AED treatment after successful epilepsy
surgery.
PMID- 10668695
TI - Status epilepticus in stroke: report on a hospital-based stroke cohort.
AB - OBJECTIVE: To evaluate occurrence rate, clinical data, and prognostic factors of
status epilepticus (SE) after stroke. METHODS: From 1984 to 1994, 3,205 patients
were admitted to the Department of Neurology at our institution with first-time
strokes. A total of 159 of these patients had first-time poststroke seizures.
Among these 159 patients, cases of SE were identified and evaluated. RESULTS: SE
was recognized in 31 patients (19%). In 17 patients, SE was the first epileptic
symptom (initial SE), and in 4 patients, stroke began with SE (S-SE). In the 14
remaining patients, SE occurred after one or more seizure(s). After a mean follow
up period of 47 months, neurologic deterioration occurred after SE in 15
patients. This deterioration was permanent in two patients. Fifteen patients
died; in five patients, death was directly related to SE. Eight of the 17
patients with initial SE and all 14 patients with SE after one or more seizure(s)
developed other seizures or SE. S-SE, however, was not a predictive factor for
additional seizure(s). CONCLUSIONS: Status epilepticus is common among patients
with poststroke seizures. Although the immediate prognosis of patients with
status epilepticus is poor, status epilepticus as the presenting sign did not
necessarily predict subsequent epilepsy.
PMID- 10668696
TI - Incidence and prognostic significance of fever following intracerebral
hemorrhage.
AB - OBJECTIVE: To investigate the incidence and prognostic significance of fever on
presentation and during the subsequent 72 hours in patients with spontaneous
supratentorial intracerebral hemorrhage (ICH). METHODS: We analyzed 251 patients.
On admission, body temperature, Glasgow Coma Scale (GCS) score, age, sex, blood
pressure, blood glucose level, and presumed origin of hemorrhage were analyzed.
From the initial CT scan, hematoma volume, location, and presence of
intraventricular hemorrhage were determined. From the first 72 hours, hematoma
enlargement, duration of increased temperatures, blood pressure, and blood
glucose level were determined. Outcome was classified on discharge with the
Glasgow Outcome Scale (GOS) score. RESULTS: Outcomes included no symptoms in 23
(9%), moderate disability in 64 (26%), severe disability in 104 (41%), vegetative
state in 5 (2%), and death in 55 (22%) patients. Prognostic factors retained from
a logistic regression model with a dichotomized GOS scale (GOS score of 1 or 2
versus GOS score of 3 to 5) as response variables were GCS score of 7 or less,
age older than 75 years, hematoma volume of more than 60 cm3, ventricular
hemorrhage, and presence of a coagulation disorder (p < 0.05). Fever was
associated with intraventricular hemorrhage. From 196 patients, data from the
first 72 hours were analyzed. A total of 18 patients (9%) had normal temperatures
throughout the study. The duration of fever (> or =37.5 degrees C) was less than
24 hours in 66 (34%), 24 to 48 hours in 70 (36%), and more than 48 hours in 42
patients (21%). Independent prognostic factors during the first 72 hours were
duration of fever, secondary hemorrhage, GCS score of 7 or less, ventricular
hemorrhage, hematoma volume of more than 60 cm3, duration of increased blood
pressure of more than 48 hours, and duration of increased blood glucose of more
than 48 hours. CONCLUSIONS: The incidence of fever after supratentorial ICH is
high, especially in patients with ventricular hemorrhage. In patients surviving
the first 72 hours after hospital admission, the duration of fever is associated
with poor outcome and seems to be an independent prognostic factor in these
patients.
PMID- 10668697
TI - Hypoxia, hyperoxia, ischemia, and brain necrosis.
AB - BACKGROUND: Human brains show widespread necrosis when death occurs after coma
due to cardiac arrest, but not after hypoxic coma. It is unclear whether hypoxia
alone can cause brain damage without ischemia. The relationship of blood
oxygenation and vascular occlusion to brain necrosis is also incompletely
defined. METHODS: We used physiologically monitored Wistar rats to explore the
relationship among arterial blood oxygen levels, ischemia, and brain necrosis.
Hypoxia alone (PaO2 = 25 mm Hg), even at a blood pressure (BP) of 30 mm Hg for 15
minutes, yielded no necrotic neurons. Ischemia alone (unilateral carotid
ligation) caused necrosis in 4 of 12 rats, despite a PaO2 > 100 mm Hg. To reveal
interactive effects of hypoxia and ischemia, groups were studied with finely
graded levels of hypoxia at a fixed BP, and with controlled variation in BP at
fixed PaO2. In separate series, focal ischemic stroke was mimicked with transient
middle cerebral artery (MCA) occlusion, and the effect of low, normal, and high
PaO2 was studied. RESULTS: Quantitated neuropathology worsened with every 10 mm
Hg decrement in BP, but the effect of altering PaO2 by 10 mm Hg was not as great,
nor as consistent. Autoradiographic study of cerebral blood flow with 14C
iodoantipyrine revealed no hypoxic vasodilatation during ischemia. In the MCA
occlusion model, milder hypoxia than in the first series (PaO2 = 46.5 +/- 1.4 mm
Hg) exacerbated necrosis to 24.3 +/- 4.7% of the hemisphere from 16.6 +/- 7.0%
with normoxia (PaO2 = 120.5 +/- 4.1 mm Hg), whereas hyperoxia (PaO2 = 213.9 +/-
5.8 mm Hg) mitigated hemispheric damage to 7.50 +/- 1.86%. Cortical damage was
strikingly sensitive to arterial PaO2, being 12.8 +/- 3.1% of the hemisphere with
hypoxia, 7.97 +/-4.63% with normoxia, and only 0.3 +/- 0.2% of the hemisphere
with hyperoxia (p < 0.01), and necrosis being eliminated completely in 8 of 10
animals. CONCLUSIONS: Hypoxia without ischemia does not cause brain necrosis but
hypoxia exacerbates ischemic necrosis. Hyperoxia potently mitigates brain damage
in this MCA occlusion model, especially in neocortex.
PMID- 10668698
TI - Stroke in children: the coexistence of multiple risk factors predicts poor
outcome.
AB - OBJECTIVE: To characterize the risk factors for stroke in children and their
relationship to outcomes. METHODS: We reviewed charts of children with ischemic
and hemorrhagic stroke seen at Hopital Sainte-Justine, Montreal between 1991 and
1997. RESULTS: We found 51 ischemic strokes: 46 arterial and 5 sinovenous
thromboses. Risk factors were variable and multiple in 12 (24%) of the 51
ischemic strokes. Ischemic stroke recurred in 3 (8%) patients with a single or no
identified risk factor and in 5 (42%) of 12 patients with multiple risk factors
(p = 0.01). We also found 21 hemorrhagic strokes, 14 (67%) of which were caused
by vascular abnormalities. No patient with hemorrhagic stroke had multiple risk
factors. Hemorrhagic stroke recurred in two patients (10%). Outcome in all 72
stroke patients was as follows: asymptomatic, 36%; symptomatic epilepsy or
persistent neurologic deficit, 45%; and death, 20%. Death occurred more
frequently in patients with recurrent stroke (40%) than in those with
nonrecurrent stroke (16%). CONCLUSIONS: Multiple risk factors are found in many
ischemic strokes and may predict stroke recurrence. Recurrent stroke tends to
increase rate of mortality. Because of the high prevalence and importance of
multiple risk factors, a complete investigation, including hematologic and
metabolic studies and angiography, should be considered in every child with
ischemic stroke, even when a cause is known.
PMID- 10668699
TI - Evaluation of antiretroviral drug efficacy for HIV-1 encephalitis in SCID mice.
AB - OBJECTIVES: To compare the efficacy of the nucleoside reverse transcriptase
inhibitors (NRTIs) abacavir, zidovudine (AZT), lamivudine (3TC), didanosine
(ddI), and stavudine (d4T) to inhibit viral replication in brain macrophages. A
severe combined immunodeficiency (SCID) mouse model of HIV-1 encephalitis (HIVE)
was used to monitor spreading viral infection in the CNS. BACKGROUND: The
development of antiretroviral therapies with CNS efficacy against neuroinvasive
virus is important if eradication of HIV-1 can be achieved within critical
"hidden reservoirs." METHODS: HIV-1-infected human monocyte-derived macrophages
(MDMs) (after a single round of viral replication) were inoculated into the
caudate and putamen of SCID mice. This resulted in the spreading of viral
infection with a concomitant multinucleated giant cell encephalitis
(astrogliosis, microglial activation, and neuronal injury). NRTIs were
administered to animals at the time of intracerebral MDM inoculations and
continued until the time of sacrifice. Antiretroviral effects were assessed by
viral load and percentages of infected MDMs. RESULTS: In brains of SCID mice with
HIVE, abacavir and lamivudine reduced HIV-1 p24 antigen-positive cells by 80% and
95%, respectively, whereas both decreased viral load by approximately 1 log.
Zidovudine, didanosine, and stavudine showed variable effects. CONCLUSION:
Abacavir and lamivudine showed significant antiretroviral activity in SCID mice
with HIVE when compared with other NRTIs. The extrapolation of these results to
humans with HIV-1 dementia awaits future investigations.
PMID- 10668700
TI - Perfusion MRI detects rCBF abnormalities in early stages of HIV-cognitive motor
complex.
AB - OBJECTIVE: To evaluate patients with early HIV-cognitive motor complex (HIV-CMC)
for possible regional cerebral blood flow (rCBF) abnormalities on perfusion MRI
(pMRI). BACKGROUND: Nuclear medicine techniques have demonstrated global and
focal cerebral perfusion abnormalities in patients with HIV dementia. Ultrafast
pMRI enables the measurement of rCBF throughout the brain without the need to
apply radioactive tracers or ionizing radiation. METHODS: pMRI was used to
measure the rCBF in 19 patients with early stages of HIV-CMC and 15 healthy
seronegative control subjects. The rCBF maps were registered to high-resolution
anatomic MRI scans and transformed into Talairach space. Statistical analysis of
the rCBF maps was performed with SPM96. RESULTS: Compared with the control
subjects, the patients with HIV had statistically significantly decreased rCBF
bilaterally in the inferior lateral frontal cortices (right: -15%, p < 0.002;
left: -12%, p < 0.005) and in the inferior medial parietal brain region (-15%, p
< 0.0009). In contrast, rCBF was increased bilaterally in the posterior inferior
parietal white matter (right: +19%, p < 0.0001; left: + 17%, p < 0.001).
Furthermore, rCBF abnormalities correlated significantly with clinical disease
severity as measured by CD4 count, plasma viral load, Karnofsky score, and HIV
dementia scale. DISCUSSION: Our results are consistent with previous findings
from PET and SPECT studies. Furthermore, pMRI can detect rCBF abnormalities that
correlate with disease severity in HIV-CMC. Because pMRI is more cost-effective,
faster, and safer than nuclear medicine techniques for monitoring rCBF changes,
pMRI may be more feasible for monitoring the effects of therapy for HIV-CMC.
PMID- 10668701
TI - The association between APOE and dementia does not seem to be mediated by
vascular factors.
AB - OBJECTIVE: The effect of APOE on dementia may be mediated through dyslipidemia
and atherogenesis through its effect on cholesterol metabolism. The authors
investigated this possibility among aged survivors from the UK Medical Research
Council Trial of the Treatment of Hypertension in Older Adults. DESIGN: A total
of 370 of 657 survivors from an initial cohort of 1,088 recruited into the trial
between 1983 and 1985 were traced in 1994 and agreed to be screened for dementia.
Blood samples were analyzed for APOE genotype and serum fibrinogen. Cholesterol
level, smoking behavior, blood pressure, body mass index, and EKG recordings had
been measured at recruitment 10 to 12 years earlier. Odds ratios (ORs) for the
association between APOE epsilon4/* and both AD and dementia were estimated and
adjusted incrementally for the effect of age and premorbid intelligence,
cholesterol, other risk factors for vascular disease, and EKG evidence of
cardiovascular disease. RESULTS: The authors diagnosed 24 cases of National
Institute of Neurological and Communicative Disorders and Stroke AD from 41 cases
of dementia. The crude OR for the association between APOE epsilon4/* and AD was
3.40 (95% CI 1.30 to 8.91). APOE genotype was associated with serum cholesterol
level, and there was a nonsignificant trend for an association with smoking
behavior. After adjusting for these and all other vascular risk factors and
vascular disease variables listed earlier, the OR for the association between
APOE epsilon4/* and AD increased to 4.81 (1.60 to 14.4). CONCLUSION: Presence of
APOE epsilon4/* seems to increase the risk for dementia and AD independently of
its effect on dyslipidemia and atherogenesis.
PMID- 10668702
TI - E4 allele dosage does not predict cholinergic activity or synapse loss in
Alzheimer's disease.
AB - OBJECTIVE: To investigate the relationship between apolipoprotein E (APOE)
genotype and both cholinergic dysfunction and synapse loss in AD. BACKGROUND: A
reduction in neocortical synapses and marked losses in the cholinergic system
occur in AD. It has been suggested that the number of APOE epsilon4 alleles is
inversely related to choline acetyltransferase (ChAT) activity, thereby
influencing cholinergic function. Whether APOE genotype may influence neocortical
synapse loss remains unclear. METHODS: An autopsy series of 182 patients with AD
(National Institute on Aging and Consortium to Establish a Registry for
Alzheimer's Disease criteria) and 16 normal controls (NC). APOE genotype was
determined in blood samples or in postmortem brain tissue. Midfrontal synapse
counts (AU/microg) were quantified by a dot-immunobinding assay for synaptophysin
(Syn). Midfrontal ChAT activity (nmol/h/100 mg) was assessed using standard
assays. RESULTS: Mean midfrontal ChAT activity and Syn were both significantly
reduced in patients with AD compared with NC. The relationship between ChAT
activity and number of epsilon4 allele copies in AD was complex, with ChAT
activity lower in patients with either two or no epsilon4 alleles compared with
those with one epsilon4 allele. There was no relationship between APOE genotype
and synapse loss in AD. Syn density was almost identical across the three
genotypes. CONCLUSIONS: Unlike other studies, we failed to detect a linear
relationship between ChAT activity and number of epsilon4 allele copies in the
midfrontal cortex of this large sample of patients with AD. Our data also show
that the presence of epsilon4 allele does not influence midfrontal synapse loss
in AD. This suggests that factors other than APOE genotype may be operative in
the decline in midfrontal cholinergic function and synapses seen in AD.
PMID- 10668703
TI - Cholinergic dysfunction in diseases with Lewy bodies.
AB - OBJECTIVE: To evaluate cholinergic activity in diseases with Lewy bodies (LB; LB
variant of AD [LBV], diffuse LB disease [DLBD], and Parkinson's disease [PD]) to
determine if 1) AD changes are requisite to cholinergic dysfunction, 2)
cholinergic activity declines to the same extent in neocortical and archicortical
areas, and 3) cholinergic loss is influenced by APOE genotype. BACKGROUND: Like
AD, diseases with LB are associated with decreased choline acetyltransferase
(ChAT) activity. Increased APOE epsilon4 allele frequency has been reported in
LBV. Whether APOE genotype affects cholinergic function in LBV remains unclear.
METHODS: An autopsy series of 182 AD (National Institute on Aging and Consortium
to Establish a Registry for Alzheimer's Disease criteria), 49 LBV, 11 PD, 6 DLBD,
and 16 normal control (NC) subjects. APOE genotype and ChAT activity (nmol/h/100
mg) in the midfrontal and hippocampal cortices were determined. RESULTS: Mean
midfrontal ChAT activity was markedly reduced in diseases with LB (LBV: 53.3 +/-
39.0; PD: 54.8 +/- 35.7; DLBD: 41.3 +/- 24.8) compared to NC (255.4 +/- 134.6; p
< 0.001) and AD (122.6 +/- 78.9; p < 0.05). Among diseases with LB, midfrontal
ChAT activity was decreased to a similar extent in patients with (LBV) and
without (DLBD and PD) AD pathology. Although mean ChAT activity for LBV was less
than half that for AD in the midfrontal cortex, it was similar to that for AD in
the hippocampus (LBV: 243.5 +/- 189.7; AD: 322.8 +/- 265.6; p > 0.05). However,
hippocampal ChAT activity for both AD and LBV was lower than that for NC (666.5
+/- 360.3; p < 0.001). The epsilon4 allele dosage did not influence midfrontal
ChAT activity in LBV. CONCLUSION: Marked losses in midfrontal ChAT activity occur
in diseases with LB, independent of coexistent AD changes. A greater midfrontal,
as opposed to hippocampal, cholinergic deficit may differentiate LBV from AD. The
lack of a relationship between epsilon4 allele dosage and midfrontal ChAT
activity suggests that other factors may play a role in its decline in LBV.
PMID- 10668704
TI - APOE epsilon4 does not predict mortality, cognitive decline, or dementia in the
oldest old.
AB - OBJECTIVE: To examine the effect of the epsilon 4 allele on cognitive decline in
the oldest old. METHODS: We studied all 601 citizens of the city of Vantaa age 85
years and older in 1991. A total of 553 subjects (92%) took part in the study,
which used the Mini-Mental State Examination (MMSE) and assessment of dementia
according to the Diagnostic and Statistical Manual of Mental Disorders, third
ed., revised (DSM-III-R) criteria. The survivors were re-examined 3 years later.
APOE genotype was determined in 510 subjects, representing 83.2% of the original
population. RESULTS: Approximately one-half of the subjects (n = 250) died before
the follow-up, and 253 subjects (97.3% of the survivors) were re-examined. The
occurrence of the APOE epsilon 4 allele did not have any significant effect on
survival. Of the 187 previously nondemented subjects, 58 (31%) had developed
dementia. The OR for the epsilon 4 carriers to develop dementia was not
significant: OR = 1.78; 95% CI = 0.88 to 3.60. In individuals with a follow-up
MMSE score (n = 222), the mean decline in the score was 3.1 points. APOE epsilon
4 carrier status did not have a significant effect on the mean MMSE change except
in the previously demented subjects, among whom the drop was larger in the APOE
epsilon 4 carriers. CONCLUSIONS: The lack of association between APOE epsilon 4
carrier status and mortality, or development of dementia, or cognitive decline in
these very elderly people, whether analyzed in the whole population or among the
nondemented subjects only, suggests that the APOE epsilon 4 effect in younger
subjects is age-dependent, and that it is no longer present in very old age.
PMID- 10668705
TI - Early-life risk factors and the development of Alzheimer's disease.
AB - OBJECTIVE: To investigate the association of early-life factors with AD.
BACKGROUND: The early-life environment and its effect on growth and maturation of
children and adolescents are linked to many adult chronic diseases (heart
disease, stroke, hypertension, and diabetes mellitus), and these effects are also
linked to maternal reproduction. AD may have an early-life link. The areas of the
brain that show the earliest signs of AD are the same areas of the brain that
take the longest to mature during childhood and adolescence. A poor-quality
childhood or adolescent environment could prevent the brain from reaching
complete levels of maturation. Lower levels of brain maturation may put people at
higher risk for AD. METHODS: In a community-based case-control study (393 cases,
377 controls), we investigated the association of early-life factors and AD.
Early-life variables include mother's age at patient's birth, birth order, number
of siblings, and area of residence before age 18 years. Patient education level
and apolipoprotein E (APOE) genotypes were also included in the analysis.
RESULTS: Area of residence before age 18 years and number of siblings are
associated with subsequent development of AD. For each additional child in the
family the risk of AD increases by 8% (OR = 1.08, 95% CI = 1.01 to 1.15). More
controls compared with cases grew up in the suburbs (OR = 0.45, 95% CI = 0.25 to
0.82). APOE epsilon 4 and the patient's education level did not confound or
modify the associations. CONCLUSIONS: The early-life childhood and adolescent
environment is associated with the risk of AD.
PMID- 10668706
TI - Lu 25-109, a muscarinic agonist, fails to improve cognition in Alzheimer's
disease. Lu25-109 Study Group.
AB - OBJECTIVE: To evaluate the therapeutic effect of the selective muscarinic
receptor m1 partial agonist, m2 antagonist, Lu25-109-a compound that directly
stimulates muscarinic cholinergic receptors-in patients with probable AD.
METHODS: A 6-month, randomized, double-blind, placebo-controlled, parallel group
trial comparing three doses of Lu25-109 with placebo was carried out. A total of
496 patients with probable AD with a Mini-Mental State Examination score between
10 and 26 were enrolled at 29 centers and randomized to placebo or Lu25-109 25,
50, or 100 mg tid. The primary efficacy measures were the AD Assessment Scale
Cognitive subscale and the AD Cooperative Study Clinical Global Impression of
Change. Secondary efficacy variables included the AD Cooperative Study Inventory
of Activities of Daily Living and the Behavioral Symptoms in AD Scale. RESULTS:
In both an intent-to-treat and a completer's analysis there were no significant
differences for either the two primary or the secondary variables. There was a
trend for patients on the highest drug dose to worsen in the completer's
analysis. Adverse events included dizziness, nausea, diarrhea, fatigue, increased
sweating, and anorexia, all of which increased with increasing drug dose.
CONCLUSION: Lu25-109, a selective partial ml agonist and an m2/m3 antagonist,
failed to improve cognition in patients with mild to moderate AD.
PMID- 10668707
TI - Gender differences in the treatment of behavior problems in Alzheimer's disease.
SAGE Study Group. Systemic Assessment of Geriatric drug use via Epidemiology.
AB - OBJECTIVE: To define gender differences in noncognitive behavioral problems of
patients with AD and differences in the associated treatment of those problems.
DESIGN/METHODS: We performed an observational study using the Systematic
Assessment and Geriatric drug use via Epidemiology (SAGE) database, which
contains data collected with the Minimum Data Set on a cross-section of nursing
home residents in five US states. Behavior problems were documented at the first
assessment of 28,367 residents with AD. We evaluated the role of gender
differences in behavior as predictors of differences in nonpharmacologic versus
specific pharmacologic therapies with psychoactive medications using logistic
regression. RESULTS: Men were more likely than women to exhibit behavior problems
such as wandering, abusiveness, and social impropriety (59% versus 50% for any
behavior problem). Hallucinations and delusions as well as depression were
equally prevalent in men and women. Nevertheless, men were more likely to receive
psychoactive medications. Among the specific drug categories examined, and
controlling for age and degree of cognitive impairment, men were more likely to
receive antipsychotic drugs and less likely to be receiving antidepressants.
CONCLUSION: Gender appears to play an important role in determining the frequency
of behavioral problems in nursing home residents with AD, which may influence
choice of treatments as well as the decision whether to treat. The use of more
potent tranquilizers in men with problem behaviors has potential implications for
morbidity, deserving further investigation.
PMID- 10668708
TI - Lack of association of the alpha2-macroglobulin locus on chromosome 12 in AD.
AB - OBJECTIVE: Analysis of AD has revealed that the apolipoprotein E locus (APOE)
cannot account for all of the genetic risk associated with AD. Whole genome
scanning in AD families suggests that a chromosome 12 locus may contribute
significantly to disease development. The alpha2-macroglobulin gene (A2M) has
been suggested as a candidate locus for AD based on analysis of familial AD.
METHOD: We determined, in 195 neuropathologically verified AD cases and 107 age
matched control subjects, the association of two common polymorphisms in A2M (a
pentanucleotide deletion 5' to the bait domain exon, and a valine-1000-isoleucine
polymorphism in the thiolester site of the protein). RESULTS: Evidence was
observed for linkage disequilibrium between the deletion and Ile1000
polymorphisms. No evidence was observed for an association between the thiolester
polymorphism and AD alone or when accounting for the APOE-epsilon4 allele. No
alteration in the frequency of the bait domain deletion was observed, although a
small excess (4%) of deletion homozygotes was found in the AD group, which were
absent in the control population. CONCLUSIONS: The A2M deletion polymorphism at
most accounts for a small fraction of the genetic contribution toward AD, and
this is small compared with APOE. Furthermore, reverse transcriptase PCR of A2M
RNA from the brains of patients homozygous for the deletion polymorphism showed
that the bait domain exon still is present in the RNA. This suggests that the A2M
deletion polymorphism may be nonfunctional and that the chromosome 12 AD locus is
situated elsewhere.
PMID- 10668709
TI - Alpha2 macroglobulin and the risk of Alzheimer's disease.
AB - BACKGROUND: alpha2 Macroglobulin is a panproteinase inhibitor that is found
immunohistochemically in neuritic plaques, a requisite neuropathologic feature of
AD. Recently, a pentanucleotide deletion near the 5' end of the "bait region" of
the alpha2 macroglobulin (A2M) gene was reported to be associated with AD in a
large cohort of sibpairs, in which the mutation conferred a similar odds ratio
with AD as the APOE-epsilon4 allele for carriers of at least one copy of the A2M
gene (Mantel-Haenszel odds ratio, 3.56). METHODS: We studied three independent
association samples of AD patients (n = 309) with an age range of 50 to 94 years
and representative controls (n = 281) to characterize the allele frequency of the
pentanucleotide deletion in this cohort. We detected the mutation near the 5'
splice site of exon 18 using standard PCR and restriction fragment length
polymorphism methods. The results were adjusted for age, gender, education, and
APOE polymorphism. RESULTS: We found that the A2M gene polymorphism conferred an
increased risk for AD, with an estimated Mantel-Haenszel ratio of 1.5 (95% CI 1.1
to 2.2; p = 0.025). There was no age- or gender-dependent increase in A2M gene
allele frequencies in AD patients compared with controls. The combined sample
showed the expected association between AD and APOE-epsilon 4. In one of our
three samples there was an interaction between the A2M and APOE-epsilon4 genes,
but the other two samples showed no interaction between the two risk factors.
CONCLUSIONS: Our data support an association between the A2M gene and AD. This
association is less pronounced, however, in our cohort than in the previously
reported sample of sibpairs.
PMID- 10668710
TI - Internal carotid artery dissection.
PMID- 10668711
TI - Alpha2-macroglobulin polymorphism is not associated with AD or AD-type
neuropathology in the Japanese.
AB - BACKGROUND: alpha2-Macroglobulin (A2M) forms the complex with amyloid beta
protein (Abeta) and is associated with degradation of Abeta. It has been reported
that the A2M gene (A2M) exon 18 splice acceptor deletion polymorphism influences
the development of AD, regardless of apolipoprotein E-epsilon4 (APOE-epsilon4)
status. OBJECTIVE: To determine the effect of A2M polymorphism on the development
of AD and AD-type neuropathologic changes. METHODS: The authors examined the A2M
and APOE genotypes, the densities of the senile plaques (SPs), SPs with
dystrophic neurites (NPs), and neurofibrillary tangles (NFTs) in the brains of 62
postmortem-confirmed sporadic AD and 90 nondemented patients from an autopsy
series of elderly Japanese subjects. RESULTS: There was no association of the A2M
polymorphism with AD, age at onset, or duration of illness in AD. The A2M
polymorphism was not associated with the SPs, NPs, or NFTs in AD or nondemented
patients. The results remained insignificant, even when the A2M genotype groups
were divided into subgroups by APOE-epsilon4 status. CONCLUSION: The A2M
polymorphism does not affect the development of sporadic AD or formation of AD
type neuropathologic changes.
PMID- 10668712
TI - Prevalence and outcomes of vascular cognitive impairment. Vascular Cognitive
Impairment Investigators of the Canadian Study of Health and Aging.
AB - OBJECTIVE: To assess the importance of vascular cognitive impairment and its
three subgroups (cognitive impairment, no dementia; vascular dementia; and AD
with a vascular component) to the prevalence and burden of cognitive impairment
in elderly people. BACKGROUND: Vascular lesions may produce a spectrum of
cognitive changes. Omitting elderly patients whose cognitive impairment falls
short of dementia (vascular cognitive impairment, no dementia) may give a falsely
low indication of the prevalence and burden of disease. To test this proposition,
we compared the rates of adverse outcomes for patients with no cognitive
impairment, vascular cognitive impairment (and its subgroups), and probable AD.
METHODS: The Canadian Study of Health and Aging is a prospective cohort study of
10,253 randomly selected community-dwelling and institution-dwelling respondents
aged 65 years or older. In the community, all participants (n = 9,008) were
screened for cognitive impairment; those who screened positive and a sample of
those who screened negative received a clinical assessment (n = 1,659). All
patients living in institutions received a clinical assessment (n = 1,255).
Participants were reassessed 5 years after the original survey. RESULTS: Vascular
cognitive impairment without dementia was the most prevalent form of vascular
cognitive impairment among those aged 65 to 84 years. Rates of
institutionalization and mortality for those with vascular cognitive impairment
were significantly higher than those of people who had no cognitive impairment,
and the mortality rate for patients with vascular cognitive impairment was
similar to that of patients with AD. CONCLUSIONS: Failure to consider vascular
cognitive impairment without dementia underestimates the prevalence of impairment
and the risk for adverse outcomes associated with vascular cognitive impairment.
PMID- 10668713
TI - Rate of functional decline in Huntington's disease. Huntington Study Group.
AB - OBJECTIVE: To determine the rate of functional decline in a large cohort of
patients with Huntington's disease (HD) followed at 43 sites by the Huntington
Study Group (HSG). METHODS: The annual rate of functional decline was measured
using the Total Functional Capacity Scale (TFC) and the Independence Scale (IS)
in 960 patients with definite HD followed prospectively for a mean of 18.3
months. All patients were rated with the Unified Huntington's Disease Rating
Scale (UHDRS). Sample size calculations for hypothetical clinical trials were
calculated. RESULTS: A factor analysis of the UHDRS at baseline yielded 15
factors accounting for 77% of the variance. The TFC score declined at a rate of
0.72 units/year (standard error [SE] 0.04) and the IS score declined at a rate of
4.52 units/year (SE 0.23). Lower TFC score at baseline, indicating more severe
impairment, was associated with less rapid annual decline in TFC score, perhaps
reflecting the floor effect of the scale. The annual rate of decline for 575
patients with baseline TFC scores of 7 to 13 was 0.97 (SE 0.06), was 0.38 (SE
0.08) for 270 patients with baseline TFC scores of 3 to 6, and was 0.06 (SE 0.1)
for 101 patients with TFC scores of 0 to 2. In multivariate analysis (n = 960),
longer disease duration and better cognitive status at baseline were associated
with a less rapid rate of decline in TFC score, whereas depressive symptomatology
was the only factor associated with more rapid decline on the IS score. Age at
onset of HD, sex, weight, and education did not affect decline on either score.
CONCLUSIONS: The comparable rates of decline on the TFC and the IS scores with
other published studies suggest that these estimates of functional decline are
representative of HD patients who are evaluated at HSG research sites. In
longitudinal analysis, longer disease duration and better neuropsychological
performance at baseline were associated with a less rapid rate of decline in TFC
score, whereas depressive symptomatology at baseline was associated with a more
rapid decline in the IS score. These rates of functional decline and the
covariates that modify them should be considered in estimating statistical power
and designing future therapeutic trials involving HD patients with early or
moderately severe disease.
PMID- 10668714
TI - Effects of central dopaminergic stimulation by apomorphine on speech in
Parkinson's disease.
AB - OBJECTIVE: To determine the effect of central dopaminergic stimulation with
apomorphine on speech in PD. BACKGROUND: Most patients with PD have a speech
disorder. Of those, 89% have involvement of laryngeal function, and 45% have
additional articulatory dysfunction. The effect of dopaminergic medications on
these two dimensions of speech impairment in PD has not been selectively studied.
METHODS: In a randomized, double-blind, placebo-controlled crossover design,
patients with PD and speech impairment, Hoehn and Yahr stages 2 to 4 "off," and
without severe dyskinesias were given placebo or apomorphine injections 0.05
mg/kg subcutaneously during two consecutive outpatient visits. They were
pretreated with domperidone for 48 hours and were tested off their parkinsonian
medications for 12 hours. Laryngeal function was assessed by maximum sustained
vowel phonations and comfortable vowel phonations. Articulatory function was
evaluated by speech intelligibility score, speaking rate, and efficiency ratio.
RESULTS: Ten patients, mean age 73.4 years (SD = 6.6), disease duration 8.7 years
(SD = 6.3), were tested. The baseline motor score on the Unified Parkinson's
Disease Rating Scale (UPDRSm) and all experimental speech variables were
equivalent on both placebo and apomorphine days. At a dose of apomorphine that
provoked improvement in UPDRSm (p = 0.0078), no index of either laryngeal or
articulatory function improved significantly after apomorphine administration.
CONCLUSION: Laryngeal and articulatory speech components are not under prominent
dopaminergic control in PD. Treatment regimens should focus on nondopaminergic
pharmacology and other therapies.
PMID- 10668715
TI - Autosomal dominant diffuse leukoencephalopathy with neuroaxonal spheroids.
AB - OBJECTIVE: To provide clinical, MRI, and histopathologic findings in a rare white
matter disorder with autosomal dominant inheritance, so-called hereditary diffuse
leukoencephalopathy with spheroids (HDLS). BACKGROUND: Progressive
leukoencephalopathies often constitute a diagnostic dilemma in both children and
adults. In some cases, histopathologic examination of brain tissue is required
for a classifying diagnosis. METHODS: Clinical history, MRI, and autopsy findings
were reviewed in three patients with HDLS: a father, his daughter, and an
unrelated patient. RESULTS: Clinical history consisted of an adult-onset
neurologic deterioration with signs of frontal lobe dysfunction, epilepsy,
spasticity, ataxia, and mild extrapyramidal disturbances. MRI findings included
cerebral atrophy and patchy white matter changes, most pronounced in the frontal
and frontoparietal area with extension through the posterior limb of the internal
capsule into the pyramidal tracts of the brainstem. Autopsy in two patients
revealed a leukoencephalopathy with frontoparietal and frontal preponderance and
numerous neuroaxonal spheroids in the abnormal white matter. The pyramidal tracts
were affected throughout the brainstem. CONCLUSION: Similar clinical and
histopathologic findings have been reported in members of a Swedish pedigree. The
homogeneity of the findings strongly suggests that HDLS is a distinct disease
entity. In the absence of a biochemical or genetic marker, a definitive diagnosis
requires histopathologic confirmation in one of the affected family members.
Neuroaxonal spheroids.
PMID- 10668716
TI - A randomized controlled trial of recombinant interferon beta-1a in ALS. Italian
Amyotrophic Lateral Sclerosis Study Group.
AB - OBJECTIVE: To evaluate the efficacy of recombinant interferon beta (IFNbeta)-1a
in the treatment of ALS. BACKGROUND: It has been proposed that IFNs affect the
progression of ALS by interfering with putative immune mechanisms involved in the
pathogenesis of the disease. METHODS: Patients (n = 61) 40 to 70 years of age
with a 6- to 24-month history of confirmed ALS with mild to moderate disability
received IFNbeta-1a, 12 mIU (n = 31), or placebo (n = 30) subcutaneously three
times a week for 6 months and were followed up for an additional 6 months.
Patients were assessed after 4, 12, 24, 36, and 48 weeks. Medical Research
Council scale, Norris scale, and bulbar scores as well as forced vital capacity
were used to assess disability. Selected electrophysiologic measures (latency,
amplitude, and duration of the compound muscle action potential) were also used.
RESULTS: Twenty patients randomized to IFNbeta-1a and 17 patients given placebo
completed the study. A total of 16 patients receiving IFNbeta-1a became non-self
supporting compared with 16 on placebo (52% versus 53%). There were no
significant differences between the two treatment groups for any of the measures
of disease progression and disability. Deaths were reported in six patients
treated with IFNbeta-1a and four patients on placebo. Adverse events were
reported more frequently with IFNbeta-1a (77% of patients) compared with placebo
(57%), with flu-like symptoms and local erythema being the commonest complaints.
CONCLUSIONS: This pilot study suggests that IFNbeta-1a is not effective in the
treatment of ALS.
PMID- 10668717
TI - Mechanism of block of nicotinic acetylcholine receptor channels by purified IgG
from seropositive patients with myasthenia gravis.
AB - OBJECTIVE: To clarify the mechanism of block of nicotinic receptor channels by
myasthenic antibodies. BACKGROUND: Nicotinic acetylcholine receptor (nAChR)
channel currents are functionally blocked by purified immunoglobulin G (IgG) of
patients with myasthenia gravis (MG). METHODS: The molecular mechanism of block
of IgG fractions containing antibodies to nAChR channels was tested with the
patch-clamp technique in combination with a system for ultrafast solution
exchange. For the experiments, outside-out patches from cultured mouse myotubes
that express embryonic-type nAChR channels at their surface were used. RESULTS:
Incubation of outside-out patches with purified IgG from four myasthenic patients
blocked nAChR channel currents activated by the application of 1.0 mM ACh
reversibly. The peak current amplitude and the time course of block of nAChR
channels decreased with increasing concentrations of IgG. The block became at
least partly irreversible if incubation time of outside-out patches exceeded 2
minutes. For the block of nAChR channel currents with a-bungarotoxin, a similar
mechanism of block was found. CONCLUSIONS: The reversibility of functional block
of nAChR channel currents by myasthenic IgG depended strongly on the incubation
time of the receptors with antibodies. Interaction of myasthenic antibodies with
nicotinic receptors may proceed in several stages from a low-affinity reversible
to a high-affinity irreversible binding.
PMID- 10668718
TI - Training the future neurology workforce.
AB - OBJECTIVE: To address training demands on future neurologists, the American
Academy of Neurology (AAN) surveyed its US members as to their views about
training the future neurology workforce. METHODS: The survey was mailed to 575 US
neurologists and 425 residents/fellows. Respondents (54%) were asked about their
perceptions of current and future educational programs and settings needed to
improve practice competence; issues related to subspecialization; and the role of
non-neurologists in providing neurologic care. Views of neurologists were
compared with those of neurology residents/fellows. RESULTS: Most respondents
support additional training in outpatient, community, and staff model health
maintenance organization settings. The majority of respondents oppose a required
fifth year of training or a yearly competency examination, but neurologists who
have a subspecialty interest and residents/fellows favor elective certification
and higher fees by subspecialists. General neurologists oppose these ideas. Most
neurologists feel that primary care physicians, nurse practitioners, and
physician assistants can manage uncomplicated neurologic problems, although
residents/fellows are less willing to accept the role of nonphysician providers
for neurologic services. CONCLUSIONS: Neurology educational programs should
consider addressing deficiencies that today's practitioners perceive. Increasing
subspecialization, although favored by most neurologists, creates a challenge for
the neurologic community as neurologists without subspecialty training see this
trend as a threat to their livelihood.
PMID- 10668719
TI - No induction of apoptosis by IFN-beta in human antigen-specific T cells.
AB - Interferon (IFN)-beta, the most effective immunomodulatory treatment for MS,
inhibits the proliferation of myelin-specific T cells. We report that IFN-beta
moderately enhances the expression of the death receptor, CD95, at the surface of
human antigen-specific T cells. However, T-cell apoptosis was not induced by
IFNbeta-1a or IFNbeta-1b as assessed by caspase activity or DNA fragmentation.
Immunomodulation mediated by IFN-beta does not directly involve apoptotic
pathways in human T cells.
PMID- 10668720
TI - Identification of new and common mutations in the EPM2A gene in Lafora disease.
AB - Lafora disease is a teenage onset progressive myoclonus epilepsy caused by
mutations in the EPM2A gene. In this report, we describe new mutations within
EPM2A, review the known mutations to date to identify the most common, and
describe three simple tests for prenatal and carrier screening.
PMID- 10668721
TI - An interrupted 34-CAG repeat SCA-2 allele in patients with sporadic
spinocerebellar ataxia.
AB - In spinocerebellar ataxia type 2 (SCA-2), a difference of three CAG repeats
distinguishes normal alleles (14 to 31 repeats) from pathogenic alleles (34 to 57
repeats). All sequenced pathogenic alleles have a pure CAG repeat structure,
whereas interrupted repeats have been seen exclusively in normal alleles. The
authors present two patients with sporadic SCA with an interrupted 34-CAG repeat
allele, (CAG)24(CAA)(CAG)9, who showed a phenotype compatible with SCA-2. The
interrupted allele coding for a 34 pure polyglutamine tract may cause the SCA
phenotype.
PMID- 10668722
TI - Isolated musculocutaneous neuropathy caused by a proximal humeral exostosis.
AB - We report an isolated musculocutaneous neuropathy caused by a proximal humeral
osteochondroma that became symptomatic after the patient played recreational
basketball. Lesion resection resulted in complete deficit resolution. Mass
lesions involving the musculocutaneous nerve should be considered in patients
with atraumatic, isolated musculocutaneous neuropathies that are recurrent or
fail to recover, even in the setting of strenuous exercise.
PMID- 10668723
TI - Atypical Friedreich ataxia phenotype associated with a novel missense mutation in
the X25 gene.
AB - We describe two sisters with early onset gait ataxia, rapid disease progression,
absent or very mild dysarthria and upper limb dysmetria, retained knee jerks in
one, slight to moderate peripheral nerve involvement, and diabetes. Molecular
analysis showed that they are compound heterozygotes for GAA expansion and a
novel exon 5a missense mutation (R165P). This mutation appears to be associated
with an atypical but not milder Friedreich ataxia phenotype.
PMID- 10668724
TI - Micturitional disturbance in pure autonomic failure.
AB - We obtained micturitional histories and performed urodynamic studies in six
patients with pure autonomic failure. All patients had urinary symptoms.
Urodynamic studies showed postmicturition residuals in two, small bladder
capacities in two, detrusor hyperreflexia in four, low bladder compliance in two,
detrusor-external sphincter dyssynergia in one, neurogenic sphincter
electromyography in three, and denervation supersensitivity of the bladder in
two. Micturitional disturbance is a common feature in pure autonomic failure
because of peripheral and central types of abnormalities.
PMID- 10668725
TI - An FDOPA PET study in patients with periodic limb movement disorder and restless
legs syndrome.
AB - The authors investigated nine drug-naive patients with periodic limb movement
disorder and restless legs syndrome (PLMD-RLS) and 27 healthy controls with PET
using 6-[18F]fluoro-L-dopa (FDOPA). In the patients, the FDOPA uptake (Ki(occ))
in the caudate nucleus was 88% and in the putamen 89% of the control mean values.
This equal affection of the caudate and the putamen differs, for example, from
the dopaminergic dysfunction in Parkinson's disease, which affects the putamen
earlier and more severely than the caudate. The current results indicate mild
nigrostriatal presynaptic dopaminergic hypofunction in PLMD-RLS.
PMID- 10668726
TI - A kindred with Parkinson's disease not showing genetic linkage to established
loci.
AB - We describe a kindred with PD with an onset age from the fifth to the eighth
decade. Genetic analysis indicated that the genetic defect in this family was
unlikely to be in the alpha-synuclein, parkin, or tau genes, or to reside on
chromosomes 2p or 4p.
PMID- 10668727
TI - A magnetization transfer imaging study of the brain in patients with migraine.
AB - The authors evaluated the magnetization transfer ratio (MTR) of T2 lesions,
normal-appearing white matter (NAWM), and brain from 39 migraineurs, 17 healthy
volunteers, and 22 patients with MS. Migraineurs had NAWM and brain MTR values
similar to those of normal subjects but significantly higher than those of MS
patients. Average lesion MTR values also were significantly lower in MS patients
than in migraineurs. In patients with migraine, other etiologies should be
considered in the presence of tissue damage beyond that seen on T2-weighted
scans.
PMID- 10668728
TI - Decreased hemispheric water mobility in hemiplegic migraine related to mutation
of CACNA1A gene.
AB - We report a reversible reduction of water diffusion in the brain during a
prolonged attack of hemiplegic migraine. The patient had a sporadic mutation of
the CACNA1A gene. The diffusion changes were observed in the contralateral
hemisphere 3 and 5 weeks after the onset of hemiplegia. These results suggest the
occurrence of hemispheric cytotoxic edema during severe attacks of hemiplegic
aura. The mechanisms underlying such ultrastructural modifications are unknown
but an abnormal release of excitatory amino acids can be hypothesized.
PMID- 10668729
TI - Ischemic strokes are more severe in Poland than in the United States.
AB - Case fatality rates for stroke were ascertained prospectively in two regional
catchment hospitals in Poland and 36 teaching hospitals in the US University
Hospital Consortium. Case fatality rates in Poland (23.9%) were higher than in
the United States (7.5%). Angina, atrial fibrillation, and congestive heart
failure were more frequent in Polish stroke patients (40%, 26%, and 25%,
respectively) than in US patients (17%, 12%, and 10%). Stroke severity as
indicated by higher frequencies of hemiplegia, disordered consciousness,
dysphagia, and aphasia was greater in Poland (19%, 39%, 28%, and 42%,
respectively) than the United States (11%, 13%, 14%, and 26%).
PMID- 10668730
TI - Exploratory saccades show no direction-specific deficit in neglect.
AB - In patients with spatial neglect, contralesional reflexive saccades toward
suddenly appearing targets show direction-specific deficits. We examined whether
these deficits also occur during free exploration of space. Neglect patients'
voluntary eye movements showed reduced amplitudes for saccades in all directions
but no direction-specific deficit. The results argue against an interpretation of
spatial neglect as a general deficit to disengage attention or to program
saccades in contralesional direction.
PMID- 10668731
TI - Spinal cord astrocytoma: response to PCV chemotherapy.
AB - Information regarding the value of chemotherapy for spinal cord astrocytomas that
progress after irradiation is limited. We describe a patient whose conus
medullaris astrocytoma responded to PCV (procarbazine, lomustine, and
vincristine) chemotherapy after failing radiation and cisplatin-based
chemotherapy. PCV should be considered in patients with progressive spinal cord
astrocytomas.
PMID- 10668732
TI - Loss of ability to sneeze in lateral medullary syndrome.
AB - Four consecutive patients with lateral medullary syndrome reported reversible
inability to complete a reflex sneeze, despite retaining the urge to do so and
the ability to mimic the motor act. This previously undescribed feature of a
relatively common syndrome is in keeping with the known location of a "sneeze
center" in the lateral medulla of cat. In man, unilateral brainstem lesion is
sufficient to abolish the sneeze reflex temporarily.
PMID- 10668733
TI - Right frontal areas 6 and 8 are associated with simultanapraxia, a subset of
motor impersistence.
AB - The authors examined brain lesions that cause simultanapraxia, a subset of motor
impersistence. Simultanapraxia was defined as the inability to perform two motor
acts simultaneously: closing the eyes and protruding the tongue. Simultanapraxia
was found in 9 (5.6%) of 160 hospitalized patients with cerebrovascular diseases.
The lesions were located in areas 6 and 8 in the right middle cerebral artery
territory. This site was spared in five patients who did not show
simultanapraxia, even with a large infarction in the right middle cerebral artery
area.
PMID- 10668734
TI - Hemodynamic changes in simple partial epilepsy: a functional MRI study.
AB - We performed functional MRI (fMRI) on a patient with a mass lesion while she
happened to experience a simple partial seizure. We used regional T2* signal
changes to localize seizure-related hemodynamic changes. Seizure activity was
associated with changes in MR signal in different regions that showed sequential
activation and deactivation. Our study has shown that epileptic activity leads to
changes in cerebral hemodynamics. In selected patients, therefore, it might be
possible to use fMRI as a noninvasive tool to detect and investigate cortical
patterns of activation associated with seizure activity.
PMID- 10668735
TI - Spinal schistosomiasis.
PMID- 10668736
TI - Selective sparing of pain pathways in a patient with adult cerebral
adrenoleukodystrophy.
PMID- 10668737
TI - Dystrophinopathy expressing as either cardiomyopathy or Becker dystrophy in the
same family.
PMID- 10668738
TI - Pupillary diameter assessment: need for a graded scale.
PMID- 10668739
TI - A clinical examination technique for mild upper motor neuron paresis of the arm.
PMID- 10668740
TI - Superior sagittal sinus thrombosis due to lithium: local urokinase thrombolysis
treatment.
PMID- 10668741
TI - Paroxysmal word deafness secondary to focal epilepsy.
PMID- 10668742
TI - Efficacy of levodopa therapy on motor function after posteroventral pallidotomy
for Parkinson's disease.
PMID- 10668743
TI - A tentative interpretation of electromyographic regional differences in bulbar
and limb-onset ALS.
PMID- 10668744
TI - Creatine monohydrate increases strength in patients with neuromuscular disease.
PMID- 10668745
TI - The biochemical pathway of neurofibrillary degeneration in aging and Alzheimer's
disease.
PMID- 10668746
TI - Bilateral infarction in the territory of the anterior cerebral arteries.
PMID- 10668747
TI - Use of microvascular free-tissue transfer following ablative surgery of the skull
base.
AB - The purpose of this study was to validate the use of free flaps in reconstruction
of skullbase defects after extensive resection of advanced tumors, and to justify
microvascular reconstruction to improve the quality of life and survival in this
population. The treatment outcome after ablative resection of skullbase tumors
with free flap reconstruction over a 7-year period (1988 to 1995) was studied.
Complete removal of the tumor was originally attempted in all patients. All cases
had immediate reconstruction. Criteria for reconstruction with free flaps were
based on extensive defects in which local flaps were insufficient. Twenty
patients were identified male:female, 11:9). The most common tumor was sarcoma,
followed by squamous-cell carcinoma. Coverage of the dura was required in 12
patients. Muscles used were the rectus abdominis and latissimus dorsi.
Complications included flap necrosis (n = 2) and ventral hernia (n = 2). Control
of pain was achieved in 66 percent of cases. Patients with regional metastasis
died within 2 years, and those with distant metastasis died within 18 months.
Patients with primary tumors had an increased survival rate. The authors confirm
the technical feasibility and success of free flaps to reconstruct extensive
defects in the skull base. In patients with potentially complete resection of
primary/recurrent lesions, overall survival justifies the procedure. Patients
with regional/distant metastasis warrant an individualized approach.
PMID- 10668748
TI - Tongue reconstruction with a combined brachioradialis-radial forearm flap.
AB - Total glossectomy adversely affects speech and swallowing, and subsequent
reconstruction results in limited functional return. The radial forearm flap has
been reliably used to resurface glossectomy defects, but has limited bulk with
which to aid in palatoglossal contact for speech. The authors have modified the
forearm flap by incorporating a segment of brachioradialis muscle, to increase
bulk posteriorly and to aid in speech. Sufficient muscle perforators arise from
the proximal brachial artery and enter the brachioradialis to permit transfer of
the muscle with the fasciocutaneous forearm flap as a single free-flap unit. The
muscle is folded onto itself and enclosed within the forearm flap skin to create
a neotongue. Coaptation of the antebrachial cutaneous nerves can provide a senate
flap. Successful transfer of the combined brachioradialis/forearm flap in a
patient who had undergone total glossectomy resulted in a neotongue good shape.
Speech was rated good by a speech pathologist, and palatoglossal contact was
observed on cineoradiograph. No functional loss at the donor site occurred.
Inclusion of the brachioradialis muscle with the radial forearm flap as a
combined unit results in a neotongue with good form and increased bulk
posteriorly at the base, compared to a standard fasciocutaneous flap alone. This
is a useful variation of the forearm flap. Sensory return is possible if the
medial and/or lateral antebrachial cutaneous nerves of the flap are coapted to
the lingual nerve.
PMID- 10668749
TI - Documentation of brachial plexus compression in the thoracic inlet with
quantitative sensory testing.
AB - This study evaluated the cutaneous pressure threshold of subjects with and
without a clinical diagnosis of brachial plexus compression in the thoracic
inlet, usually termed thoracic outlet syndrome (TOS). Sixty-one subjects (102
arms) made up the control population; 11 subjects 120 arms) made up the TOS
population. Assessment by two upper-extremity specialists preceded the testing.
The one-point cutaneous pressure threshold was measured with the Pressure
Specifying Sensory Device (PSSD) on the pulp of both the index and little finger
(upper and lower brachial plexus distributions) with the arm in the unprovoked
(adducted) and provoked (abducted 180 degrees) positions. In the control
subjects, there was no significant change in the cutaneous pressure threshold
between unprovoked and provoked positions. In contrast in patients with TOS,
there was a significant increase in the cutaneous pressure threshold at both
sites (p < .0001 ) between the unprovoked and the provoked positions.
Furthermore, the cutaneous pressure threshold for patients with TOS was
significantly higher in both positions than it was in the controls (p < .0001 ).
It was concluded that measurement of changes in the cutaneous pressure threshold
with the PSSD in distal sensory targets of the upper and lower trunk can identify
patients symptomatic for compression, when the brachial plexus is provoked as
part of the testing sequence.
PMID- 10668750
TI - Posterior radial collateral artery as the basis of the lateral forearm flap.
AB - The lateral forearm flap is being increasingly used for covering minor-to
moderate-sized defects for which soft and thin skin is required. Within the
framework of an anatomic study carried out on 28 cadaveric arms, the authors
investigated the principal artery that supplies blood to this flap namely, the
posterior radial collateral artery (PRCA). They found that distal to the lateral
epicondyle, the PRCA lies in a constant axial line lateral to the brachioradialis
muscle. The average length of the artery distal to the epicondyle is 8 cm. Distal
to the epicondyle side branches of the PRCA build an arterial plexus 6 cm (+/-3.5
cm) long and 5 cm (+/-1.1 cm) wide. The posterior cutaneous antebrachii nerve
lies close to the artery. This permits the harvesting of a flap that is both
innervated and has adequate vascular supply.
PMID- 10668751
TI - Efficacy of the "baby-sitter" procedure after prolonged denervation.
AB - This study was undertaken to evaluate whether 40 percent of the hypoglossal
nerve, which showed optimal efficacy in restoring orbicularis oculi muscle (OOM)
function after different percentages of partial neurectomy in a previous study
would be effective after prolonged denervation time. Twenty Sprague-Dawley rats
were divided into four groups. In first-stage surgery the left facial nerve of
all animals was transected at the level of the stylomastoid foramen and main
zygomatic branch. Group A (controls) consisted of animals with only left facial
nerves transected (no repair). In Groups B, C, and D the facial nerve was
transected and the facial musculature was denervated for a period of 4, 8, and 12
weeks respectively. During a second-stage procedure, a 40 percent neurectomy was
performed on the hypoglossal nerve. Subsequently, a nerve transfer was performed
by coaptations of a saphenous nerve graft to the neurectomized hypoglossal nerve
and the main zygomatic branch of the facial nerve that innervated the OOM.
Behavioral analysis of blink reflex, electrophysiology, and axon and motor end
plate counts in Groups B, C, and D showed superior results compared to Group A.
There was no statistically significant difference observed among Groups B, C, and
D (p > 0.05). Despite the diminished number of axons in the zygomatic branch and
motor end-plates in the orbicularis oculi muscle after 12 weeks of denervation,
there was still sufficient muscle target recovery to effect some eye closure in
all groups except the controls. This study demonstrated in this model that the 40
percent partial neurectomy of the XII to VII component of the "baby-sitter"
procedure was effective even after prolonged denervation.
PMID- 10668752
TI - Variations on the "baby-sitter" procedure for reconstruction of facial paralysis.
AB - Four cases of fresh facial paralysis were treated using the "baby-sitter"
procedure, with fairly satisfactory results obtained. This procedure involves a
combination of cross-face nerve grafting and a nerve cross-over technique such as
using a hypoglossal-facial nerve or accessory-facial nerve anastomosis. Two
stages are required. Nerve cross-over and cross-face nerve grafting using the
sural nerve are performed in the first stage. After 1 year nerve anastomosis
between the stump of the cross-face nerve graft and that of a buccal branch in
the paralyzed cheek is performed during the second stage. The recovery of facial
animation through this method is good, with patients able to create a near
natural smile. Electromyography demonstrates double innervation in the paralyzed
cheek area.
PMID- 10668754
TI - Biliary tract reconstruction using an autologous vein graft in rats.
AB - Numerous biologic and synthetic materials have been used with limited success as
an interposed graft to repair segmental common bile duct (CBD) defects. The
authors report here that an autologous vein graft can be successfully used to
correct a CBD deficit contingent on accurate microsurgical technique immediate
stenting and rapid graft vascularization. Thirty Sprague-Dawley rats underwent
laparotomy and the experimental group (n=25) had a 3-mm segment of the CBD
excised. The CBD defect was repaired using an interposed femoral vein graft aided
by a plastic stent. The control group (n=5) had the CBD cut and repaired by means
of primary anastomosis. The experimental group was subdivided into three sub
groups each examined at three different postoperative intervals: 1, 4 and 12
weeks. The results showed that inflammation was apparent in the venous wall
following the first postoperative week. A progressive loss of the vascular
endothelium and replacement with the columnar epithelium typical of the CBD was
seen in the vein graft. Nineteen of the 25 experimental rats (76 percent) of the
animals survived without complication from the surgery and there were no
abnormalities in the liver biochemical tests of these animals. Any biliary tract
obstruction that developed was attributed to dislocation of the stent leading to
collapse of the vein graft (experimental group), or constriction of the
anastomosis (control group). This study demonstrates that biliary tract
reconstruction using an autologous vein graft can be successfully performed in a
rat model of CBD repair. The application of this method to the clinical setting
is also discussed.
PMID- 10668753
TI - Accelerated flap prefabrication with vascular endothelial growth factor.
AB - Vascular endothelial growth factor (VEGF) is a potent promoter of angiogenesis
that has been shown to enhance revascularization of ischemic tissues, including
skin flaps. This study was designed to investigate the value of a single topical
application of recombinant human VEGF to accelerate flap viability in a rat model
of a non-ischemic prefabricated flap. Prefabricated flaps were created in 48
Sprague-Dawley rats. An autologous tail artery loop was anastomosed to the
femoral artery and vein, and implanted subcutaneously in the lower abdomen. Flaps
were divided into two groups of 24 each. At the time of loop implantation the
control group received 0.9 percent NaCl or a 16 percent vol/wet polyvinyl alcohol
(PVA) solution: the treatment group received VEGF in 0.9 percent NaCl or VEGF in
PVA. The PVA gel was used to facilitate topical application In each group, 3- x 4
cm flaps nurtured by the tail artery pedicle were elevated and resutured into
place after 3, 4, and 5 weeks. The percentage of surviving skin of each flap was
determined by planimetry 7 days after flap elevation. Mean skin survival areas at
3, 4, and 5 weeks were control group 0 percent. 8 percent and 17.5 percent; and
VEGIF-treated group, 6 percent, 40 percent, and 66.7 percent respectively VEGF
significantly improved flap survival by 5 weeks (p = 0.02). These results suggest
that VEGF can accelerate maturation of prefabricated flaps. This approach could
expand the application of flap prefabrication as a resource for reconstructive
surgery.
PMID- 10668755
TI - Composite tissue allotransplantation: a comprehensive review of the literature-
part 1.
PMID- 10668756
TI - Mind, muscles and motoneurones.
AB - This review considers some of the adaptations which take place in the central
nervous system to allow optimal performance of the musculoskeletal system for the
smallest to the largest "efforts". Mental imagery of exercise helps performance
but the way in which it works is multifactional: it evokes muscle contraction
sufficient to activate muscle receptors. Furthermore, it is possible for subjects
to focus specifically on control of particular muscles even without feedback from
them. On the other hand maximal voluntary efforts, at least in isometric and in
concentric contractions, can drive the motoneurones sufficiently to ensure full
force production by the muscle. Many neural factors contribute to maintain force
output during repetitive activity, including a feedback loop whereby increased
central command during fatigue acts to enhance muscle perfusion. As peripheral
muscle fatigue develops, changes occur in the excitability of the motor cortex.
Recent evidence suggests that "central" factors leading to reduced drive to
muscles in isometric contractions act "upstream" of motor cortical output.
PMID- 10668757
TI - Physiological determinants of endurance exercise performance.
AB - Performance in endurance events is typically evaluated by the power or velocity
that can be maintained for durations of 30 min. to four hours. The two main by
products of intense and prolonged oxidative metabolism that can limit performance
are the accumulation of hydrogen ion (i.e. lactic acidosis) and heat (i.e.
hyperthermia). A model for endurance performance is presented that revolves
around identification of the lactate threshold velocity which is presented as a
function of numerous morphological components as well as gross mechanical
efficiency. When cycling at 80 RPM, gross mechanical efficiency is positively
related to Type I muscle fiber composition, which has great potential to improve
endurance performance. Endurance performance can also be influenced by altering
the availability of oxygen and blood glucose during exercise. The latter need
forms the basis for ingesting carbohydrate at 30-60 grams per hour during
exercise. In laboratory simulations of performance, athletes fatigue due to
hyperthermia when esophageal is approximately 40 degrees C, in association with
near maximal heart rate and perceived exertion. It is likely that the central
nervous system is involved in the aetiology of fatigue from hyperthermia.
Dehydration during exercise promotes hyperthermia by reducing skin blood flow,
sweating rate and thus heat dissipation. The combination of dehydration and
hyperthermia during exercise causes large reductions in cardiac output and blood
flow to the exercising musculature, and thus has a large potential to impair
endurance performance. Endurance performance is optimized when training is aimed
specifically at developing individual components of the model presented and
nutritional supplementation prevents hypoglycemia and attenuates dehydration and
hyperthermia. Indeed, the challenge at the transition to a new millennium is to
synergistically integrate these physiological factors in training and
competition.
PMID- 10668758
TI - Optimisation of the biology of soft tissue repair.
AB - As identified in this review, over the past twenty years there have been a number
of very exciting new developments in the quest to optimise soft tissue repair.
Comparing fetal soft tissue injuries, which heal by regeneration, to the adult
processes of healing by inflammation-induced scar formation has led to a number
of insights into how the latter may be improved. Seeding wounds with embryonic
stem cells, bridging gaps with cell-derived "engineered tissues", addition of
exogenous hyaluronic acid and modification of wounds to either enhance the growth
factors which have been implicated in regeneration (e.g. TGF-B3) or block those
implicated in scar formation (eg. TGF-B1) have all shown promise. Our group has
quantified numerous cellular, molecular, biomechanical and matrix abnormalities
of scar in a rabbit model of ligament healing. Based on these studies which we
review here, three matrix deficiencies have been identified which appear to have
specific implications to scar weakness: organisational "flaws", abnormal
hydroxypyridinoline collagen cross-link densities and abnormally small, slow
maturing collagen fibrils. In tests aimed at finding therapeutic solutions in
this model, the addition of a 7ug bolus of TGF-B1 at day 21 or 2.5ng/day of TGF
B1 being pumped into a wound x 21 days increased the size of ligament scars but
did not improve their material strength. It also did not alter any of the above
noted matrix deficiencies. A liposome-mediated anti-sense gene therapy approach
aimed at decreasing the expression of the proteoglycan decorin in 21-day scars,
however, has significantly increased the size of scar collagen fibrils as well as
improved these scars mechanically. Based on these positive results from a single
dose of only one targeted molecule, we believe that this gene therapy approach
has great potential for further scar improvement. If combined with some of the
other biological strategies reviewed above, a repair which is closer to true
regenerative healing of ligaments, and all soft tissues, may eventually be
achieved.
PMID- 10668759
TI - Biological reaction to vibration--implications for sport.
AB - In many situations of everyday life, vibration load occurs. Here whole body
vibration in vehicles, such as boats, cars, helicopters and others as well as
hand-transmitted vibration (motor saws etc.) can be named. As vibration is
assumed liable to cause various threats to human health, a great number of
studies in work science focussed on dose-effect relations and concepts for
prevention. Although in many sports remarkable vibration load also occurs, there
is very little research on the potential dangers and benefits of vibration
stimuli, e.g. on whole body vibration and the implications for muscular activity
and neuromuscular control in sport. In personal studies the damping behaviour and
training effects under whole body vibration were investigated. Various research
areas have been studied in order to approach the relevant topics: neuromuscular
and posture control, energy metabolism in terms of oxygen uptake under whole body
vibration and local concentration of phosphates by means of 31P-MRS. Furthermore
the effects of a strength training under whole body vibration were analysed. The
results underline that vibration is a neglected research topic in sport science
from the preventive point of view as well as from the one focussing on the
improvement of sport performance.
PMID- 10668760
TI - Stress, anxiety and performance.
AB - Research which has examined the catastrophe models of anxiety and performance is
discussed. The conclusion drawn is that the evidence supports the notion of
hysteresis, and partially supports the interactive effects prediction of the
catastrophe models. Two potential explanations of anxiety induced performance
catastrophes are then examined, processing efficiency theory and the conscious
processing hypothesis. Process efficiency theory proposes that, as well as
reducing attentional resources, cognitive anxiety can also lead performers to
invest additional effort in the task in an attempt to allay their concerns and
fears. Thus, performance may be maintained (or even enhanced), but at an
increased physiological cost. Evidence is presented in support of the prediction
that cognitive anxiety leads to increased effort. The conscious processing
hypothesis proposes that anxious performers regress to an earlier stage of
learning when they controlled movements using conscious processes and explicit
knowledge. Evidence is presented from a number of recent studies which at least
partially support this notion. Finally, it is suggested that these two different
explanations are not necessarily mutually exclusive.
PMID- 10668761
TI - Exercise and the immune system--influence of nutrition and ageing.
AB - In essence, the immune system is enhanced during moderate and severe exercise,
and only intense long-duration exercise is followed by impairment of the immune
system. The latter includes suppressed concentration of lymphocytes, suppressed
natural killer cell activity, lymphocyte proliferation and secretory IgA in
saliva. During the time of immune impairment, referred to as "the open window",
microbial agents, especially viruses may invade the host and infections may be
established. One reason for the "overtraining effect" seen in elite athletes
could be that this window of opportunism for pathogens is longer and the degree
of immunosuppression more pronounced. Alterations in metabolism and metabolic
factors may contribute to exercise-associated changes in immune function.
Reductions in plasma-glutamine concentrations, altered plasma-glucose level, free
oxygen radicals and prostaglandins (PG) released by the elevated number of
neutrophils and monocytes may influence the function of lymphocytes and
contribute to the impaired function of the later cells. Thus, nutritional
supplementation with glutamine, carbohydrate, anti-oxidants or PG-inhibitors may,
in principle, influence exercise-associated immune function. Although several
intervention studies have been performed, it is premature to make recommendations
regarding nutritional supplementation to avoid post-exercise impairment of the
immune system.
PMID- 10668762
TI - Mechanisms of muscle injury after eccentric contraction.
AB - Eccentric contractions of skeletal muscles produce injury and, ultimately, muscle
strengthening. Current data suggests that the earliest events associated with
injury are mechanical in nature and may be based primarily on the sarcomere
strain experienced by the muscle. In this review, recent experimental data,
primarily from rabbit dorsiflexor muscles, are used to provide general
information regarding the factors that cause injury and means for preventing
injury. Mechanical experiments reveal that excessive sarcomere strain is the
primary cause of injury. We hypothesize that excessive strain permits
extracellular or intracellular membrane disruption that may permit hydrolysis of
structural proteins leading to the myofibrillar disruption that is commonly
observed. Inflammation that occurs after injury actually further degrades the
tissue, but prevention of the inflammation leads to a long-term loss in muscle
function. Simple treatments such as increasing muscle oxidative capacity
("getting into shape") or cyclic stress-relaxation of tissue ("stretching out")
have no measurable effect on the magnitude of muscle injury that occurs.
Ultimately, an improved understanding of the damage mechanism may improve our
ability to provide rehabilitative and strengthening prescriptions that have a
rational scientific basis.
PMID- 10668763
TI - Determination of optimal pacing strategy in track cycling with an energy flow
model.
AB - The purpose of this study was to investigate the effect of pacing strategies on
performance times in the 1000 m time trial event and the 4000 m pursuit event in
track cycling. For this purpose, we simulated these events with a model based on
the flow of energy in cycling. Different strategies in distributing the available
anaerobic energy were evaluated and we compared model predictions of split times
and final times with values achieved by cyclists during championships. The best
result at the 1000 m time trial was obtained when the cyclist had the highest
anaerobic peak power output and used an 'all-out' strategy. The fastest time on
the 4000 m pursuit was achieved with an 'all-out' start at a high level of
initial power output, followed by a constant anaerobic power output after 12
seconds, resulting in an evenly paced race. The results show that even small
variations in pacing strategy may have substantial effects on performance. There
seems to be an opportunity to gain a competitive advantage when individual
athletes experiment with small variations in pacing strategy to find the precise
individual strategy that works best under specific conditions.
PMID- 10668764
TI - The John Stanley Coulter lecture. Overcoming the odds: the health of women with
physical disabilities in the United States.
PMID- 10668765
TI - Functional electrical stimulation effect on orthostatic hypotension after spinal
cord injury.
AB - OBJECTIVE: To investigate the possibility of using functional electrical
stimulation (FES) to control orthostatic hypotension in patients with spinal cord
injury (SCI) and to clarify the mechanism of the response. DESIGN: Subjects were
tilted by 10 degree increments with varying intensities of lower-extremity FES.
Stimulation over muscles was compared to stimulation over noncontractile sites.
SETTING: Physical therapy department of a major rehabilitation center. PATIENTS:
Six patients with SCI above T6 (3 with recent injury recruited consecutively from
an inpatient spinal cord rehabilitation unit, and 3 from the community with
longstanding injury, recruited as volunteers). MAIN OUTCOME MEASURES: Blood
pressure, heart rate, and perceived presyncope score recorded at each tilt angle
and analyzed using a multivariate analysis of variance statistical methodology.
RESULTS: Systolic and diastolic blood pressure increased with increasing
stimulation intensities (systolic, p = .001; diastolic, p = .0019) and decreased
with increasing angle of tilt (p < .001) regardless of the site of stimulation.
Subjects tolerated higher angles of incline with electrical stimulation than
without (p = .03). CONCLUSIONS: FES causes a dose-dependent increase in blood
pressure independent of stimulation site that may be useful in treating
orthostatic hypotension.
PMID- 10668766
TI - Spasticity in spinal cord injury: self- and clinically rated intrinsic
fluctuations and intervention-induced changes.
AB - OBJECTIVES: (1) To determine patterns of intrinsic fluctuations in spasticity,
using repeated self-ratings, in subjects with spinal cord injury (SCI); and (2)
To determine the relation between self-ratings of spasticity using a visual
analogue scale (VAS) and clinical ratings of spasticity using the Modified
Ashworth Scale (MAS) before and after spasticity-reducing treatment. DESIGN: Part
I: observational, prospective cross-sectional study; part II: experimental,
prospective longitudinal study. SETTING: Outpatient clinic of the Karolinska
Hospital, Stockholm, Sweden. PATIENTS: Forty-five persons with SCI (39 men, 6
women); mean age at injury, 26 yrs; mean time since injury, 11 yrs. INTERVENTION:
Repetitive passive movements of standardized range of motion in three different
body positions, performed by two motorized tables. MAIN OUTCOME MEASURES: VAS
ratings of spasticity, every other hour when awake, and of movement-provoked
spasticity, rated before and after each treatment session, and MAS ratings of
movement-provoked spasticity, before and after each treatment session. RESULTS:
The spasticity of cervical SCI subjects fluctuated significantly (p < .05) during
the day, unlike the spasticity of thoracic SCI subjects. Immediately after
intervention with passive movements, spasticity ratings in thoracic motor
complete SCI patients decreased by 11 to 14 mm (90%, p < .001) as self-rated on
VAS and by 1 to 2 grades (50%, p < .001) as measured with MAS. A 30% (p < .018)
decrease in VAS values of intrinsic pattern of spasticity was maintained over
time when treatment was given regularly and was maintained for at least 1 week
after discontinuation of treatment. VAS ratings correlated significantly with MAS
ratings (r = .44 to .62, p < .001). CONCLUSION: Repetitive passive movement
intervention decreased spasticity when performed regularly, as assessed by VAS
and MAS ratings. VAS and MAS ratings were significantly correlated. It is
recommended that SCI patients repeatedly rate their spasticity to establish a
baseline before and to track changes after interventions aimed at reducing
spasticity. The time of day when spasticity is measured seems more important in
cervically injured individuals, because of their more pronounced intrinsic
fluctuations.
PMID- 10668767
TI - Estimation of geometric properties of cortical bone in spinal cord injury.
AB - OBJECTIVE: To evaluate structural and geometrical properties of the tibia shaft
in subjects with spinal cord injury (SCI) and subjects without SCI and to
estimate the potential usefulness of a multimodal approach to diagnosing
osteoporosis in SCI. DESIGN: A cross-sectional study of randomly selected SCI and
non-SCI subjects. METHODS: Measurements of bone geometric indices by computed
tomography, and calculated bending stiffness with a biomechanical testing method.
SETTING: An SCI center hospital. SUBJECTS: Ten men without known orthopedic or
neurologic impairments (controls), 10 men with SCI who had a history of lower
extremity pathologic fracture since SCI, and 10 men with SCI who had never had
lower extremity pathologic fracture. RESULTS: Analysis of geometric and
structural indices of subjects' tibias found a significant difference in all
geometric indices between controls and the SCI subjects with pathologic fracture
history. Between the controls and the SCI subjects with no fracture history,
however, differences were found only in cross-sectional area and calculated
bending stiffness. CONCLUSION: Structural analysis of leg bone, combined with
measurement of bone density, may improve the ability to assess fracture risk in
patients with SCI.
PMID- 10668768
TI - Myosin heavy chain isoform and ubiquitin protease mRNA expression after passive
leg cycling in persons with spinal cord injury.
AB - OBJECTIVE: To determine the effects of passive leg cycling exercise on myosin
heavy chain (MHC) isoform and ubiquitin (UBI) protease mRNA expression in
patients with spinal cord injury (SCI). STUDY DESIGN: Case series. INTERVENTION:
Eight SCI subjects (5 men, 3 women) participated in a 12-week exercise program
involving the Psycle ergometer. Training occurred 2 days a week at 75% of each
subject's maximum heart rate. Anthropometric measures (body weight, thigh girth,
and body mass index) and muscle biopsy specimens were obtained before and after
training. Analyses were performed to determine the mRNA expression of types I,
IIa, and IIx MHC, as well as UBI, a UBI-conjugating enzyme (E2), and 20S
proteasome (20S). RESULTS: Despite small increases, paired t tests (p < .05) to
assess changes from pretraining to posttraining failed to locate significant
differences for the three anthropometric measures. For mRNA expression, there
were significant increases in expression of MHC types IIa and IIx and significant
decreases in expression for UBI, E2, and 20S. CONCLUSION: Exercise using passive
leg cycling increases the expression of fast MHC isoforms while concomitantly
decreasing proteolytic activity associated with muscle degradation, thus helping
to possibly ameliorate muscle atrophy in patients with SCI.
PMID- 10668769
TI - Gabapentin effect on spasticity in multiple sclerosis: a placebo-controlled,
randomized trial.
AB - OBJECTIVE: To investigate the effect of gabapentin on subject self-report and
physician-administered spasticity scales in individuals with multiple sclerosis.
DESIGN: Prospective, double-masked, placebo-controlled, crossover design.
SETTING: The Multiple Sclerosis Center at the Denver Veterans Affairs Medical
Center. INTERVENTION: Subjects were titrated to either 900 mg gabapentin orally
three times a day or placebo over a 6-day period. Subjects underwent a 14-day
washout and then were crossed over. No other changes were made to their
medication regimen. MAIN OUTCOME MEASURES: The outcome measures were divided into
two categories: subject self-report scales physician-administered scales. Subject
self-report scales included the spasm frequency scale, spasm severity scale,
interference with function scale, painful spasm scale, and global assessment
scale. Physician-administered scales included the Modified Ashworth Scale, clonus
scale, deep tendon reflexes, plantar stimulation response, and the Kurtzke
Expanded Disability Status (EDSS) Scale. Digit Span and Digit Symbol subtests of
the WAIS-R Intelligence Scale were administered to assess for possible impaired
concentration. The Fatigue Impact Scale was administered to assess for changes in
fatigue. The adjective generation technique was administered to assess for
alterations in mood. RESULTS: A statistically significant reduction in the
impairment of spasticity was found in the gabapentin-treated subjects compared
with placebo as measured by the self-report scales of the spasm severity scale,
interference with function scale, painful spasm scale, and global assessment
scale and by the physician-administered scales of the Modified Ashworth and
plantar stimulation response. No significant difference was noted in the Digit
Span, Digit Symbol, adjective generation technique, and EDSS. CONCLUSION:
Gabapentin reduces the impairment of spasticity, compared with placebo, without
the side effects of worsening concentration and fatigue.
PMID- 10668770
TI - Cervical nonorganic signs: a new clinical tool to assess abnormal illness
behavior in neck pain patients: a pilot study.
AB - OBJECTIVE: To develop and assess the reliability of a group of cervical
nonorganic physical signs to be used as a simple screening tool for identifying
patients with low neck pain who exhibit abnormal illness behavior. DESIGN:
Survey, consecutive sample. DATA SET: Double masked. SETTING: Functional
restoration program. PATIENTS: Twenty-six consecutive patients with complaints of
chronic neck pain (greater than 4 months duration). Each patient was evaluated by
a physician and then again by either a physical or occupational therapist, for
the presence of specific cervical nonorganic signs. Both of the evaluations
occurred on the same day. MAIN OUTCOME MEASURES: Five categories consisting of
eight tests were appraised: (1) tenderness, (2) simulation, (3) range of motion,
(4) regional disturbance, and (5) overreaction. RESULTS: The percent agreement
between raters ranged from a high of 100% for regional sensory disturbance, to a
low of 68% for one of the simulation tests. The average agreement between raters
across all of the nonorganic test signs was 84.6%. Likewise, kappa coefficients
ranged from 1.00 to .16, reflecting differences in strength of agreement.
CONCLUSION: For many years, the lumbar nonorganic signs (developed by Waddell and
colleagues) have been a useful screening tool in the assessment of abnormal
illness behavior in the low back pain population. For the first time, a group of
cervical nonorganic signs have been developed, standardized, and proven reliable.
PMID- 10668771
TI - Peripheral plasma amino acid abnormalities in rehabilitation patients with severe
brain injury.
AB - OBJECTIVE: Acute severe brain injury causes an increased mobilization of amino
acids from tissue. The plasma amino acid profile of patients undergoing
rehabilitation after brain injury is unknown. This study was aimed at delineating
the plasma amino acid profile of rehabilitation patients with brain injury.
DESIGN: Peripheral plasma aminogram, lactate, pyruvate, glycerol, ketone body,
and carnitine concentrations were determined in 11 patients with brain injury
(34.6+/-15 years old, 60+/-16.8 days after injury) and in 8 controls. Resting
energy expenditure and nitrogen balance were also determined. RESULTS: (1) All
essential amino acids and about 50% of nonessential amino acids were
significantly lower in brain injury patients than in controls (p < .05). (2)
Plasma amino acids were lower irrespective of either energy and protein intake or
nitrogen balance. (3) Total carnitine concentration and esterified/free carnitine
ratio were higher in brain injury patients than in controls (p < .05).
CONCLUSIONS: Rehabilitation patients with brain injury may have an important
reduction of their plasma aminogram. Muscle tissue depletion and the persistence
of a hypercatabolic state caused by subclinical infections, pressure sores, and
immobility may contribute to this reduction.
PMID- 10668772
TI - Barriers to exercise in African American women with physical disabilities.
AB - OBJECTIVE: To examine what factors African American women with one or more
physical disabilities perceive as barriers to exercise and how they rank them.
SETTING: Department of Disability and Human Development at a major university.
STUDY DESIGN: Data were collected through telephone interview using a newly
developed instrument (Barriers to Physical Exercise and Disability [B-PED]) that
addressed issues related to physical activity and the subjects' disability.
SUBJECTS: Fifty subjects were asked questions about their participation and
interest in structured exercise. RESULTS: The four major barriers were cost of
the exercise program (84.2%), lack of energy (65.8%), transportation (60.5%), and
not knowing where to exercise (57.9%). Barriers commonly reported in nondisabled
persons (eg, lack of time, boredom, too lazy) were not observed in our sample.
Only 11% of the subjects reported that they were not interested in starting an
exercise program. The majority of subjects (81.5%) wanted to join an exercise
program but were restricted by the barriers reported. CONCLUSION: African
American women with a physical disability are interested in becoming more active
but are limited in doing so because of their inability to overcome several
barriers to increased physical activity participation.
PMID- 10668773
TI - Assessing joint pain complaints and locomotor disability in the Rotterdam study:
effect of population selection and assessment mode.
AB - OBJECTIVE: To assess the prevalence of self-assessed and physician-assessed
disability and joint pain, their association, and the effect of cohort reduction
and mode of assessment. DESIGN: Cross-sectional population survey. SETTING:
General population, age 55 years and older. SUBJECTS: Independently living
participants of the Rotterdam Study, including 1,156 men and 1,739 women. OUTCOME
MEASURES: Self-reported and physician-assessed joint complaints. Patients' self
assessment of locomotor disability was by response to questions from the Stanford
Health Assessment Questionnaire; physicians assessed patients' disability by
administering activity tests. RESULTS: Reduction of the study cohort because of
nonresponse and missing data had no influence on the frequency and effect
measures. The physician-assessed prevalence of pain of the hips, knees, or feet
was significantly lower than the self-assessed prevalence, with the percentage
agreement being 83% for men and 74% for women, with kappa-values of approximately
.40. The prevalence of physician-assessed locomotor disability was also
significantly lower than the self-assessed disability, with the percentage
agreement being 83% for men and 78% for women, with kappa values of .41 and .47,
respectively. The associations of joint complaints with disability were similar
for both modes of assessment. CONCLUSION: Cohort reduction caused by nonresponse
and missing data had no influence on estimates of frequency and association. Self
assessment gives higher prevalences of joint complaints and locomotor disability
than physician assessment, but the associations between complaints and disability
were the same.
PMID- 10668774
TI - Asymmetry of gait initiation in patients with unilateral knee arthritis.
AB - OBJECTIVE: To identify how patients with knee arthritis modify their equilibrium
and movement control strategies during gait initiation. DESIGN: Observational
study. SETTING: University hospital movement analysis laboratory. PARTICIPANTS:
Twelve patients with unilateral knee arthritis and 12 healthy control subjects.
MAIN OUTCOME MEASURES: Durations of the phases of gait initiation (ie, postural,
monopodal, and double-support phases), center-of-pressure displacements, ground
reaction forces, pelvic velocity, step length, and knee range of motion were
measured using a movement analysis system and force plates. RESULTS: Gait
initiation was slower in patients than in controls no matter which leg was the
supporting one. In patients, the durations of the postural and the monopodal
phases were modified in an asymmetrical way according to the leg used as the
supporting one. The postural phase was lengthened and the monopodal phase was
shortened when the affected leg was the supporting one. Opposite effects were
observed when the sound leg was supporting. Step length, knee range of motion,
and maximal pelvic velocity were reduced in patients whatever the side of the
supporting leg. CONCLUSION: Gait initiation is an asymmetrical process in
unilateral knee arthritis patients, who develop adaptive posturomotor strategies
that shorten the monopodal phase on the affected leg.
PMID- 10668775
TI - Measurement of brake response time after right anterior cruciate ligament
reconstruction.
AB - OBJECTIVE: Recommendations on safe driving after anterior cruciate ligament (ACL)
reconstruction have been largely intuitive. We studied brake response time in
patients who participated in outpatient rehabilitation after right ACL
reconstruction. DESIGN: Prospective, repeated measures design comparing 14
patients post-ACL reconstruction with 21 subjects with normal knees.
INTERVENTIONS AND MAIN OUTCOME MEASURES: The following measures were assessed
every 2 weeks for 10 weeks: brake response time, 6-meter walk time, knee range of
motion, pain, and joint effusion. Statistical testing used analysis of covariance
with repeated measures. Significant variables were analyzed separately and post
hoc tests conducted using the least squares differences method. Both groups were
compared with published norms from the American Automobile Association. RESULTS:
No significant gender differences across main effects were detected. Brake
response times for men improved significantly after week 6 (p < .05) and week 10
(p < .01). Brake response times for women in the ACL treatment group matched
controls at 6 weeks. Six-meter walk times for control subjects were faster than
those for the ACL group preoperatively (2.6 sec vs 5.5 sec), but equalized by
week 6. CONCLUSIONS: After right ACL reconstruction, brake reaction times of
rehabilitated men and women matched those of established controls after 4 to 6
weeks. Measuring brake response times during rehabilitation may ensure that
individual patients return to driving in a safe and timely manner.
PMID- 10668776
TI - Social issues in the rehabilitation of younger stroke patients.
AB - OBJECTIVES: To study social factors and outcomes in stroke rehabilitation
patients under the age of 50. STUDY DESIGN: Retrospective chart review examining
(1) martial status and employment status on admission and at 3 months post
discharge, (2) discharge destination, (3) the presence of absence of children
under the age of 16, and (4) psychosocial difficulties as recorded by staff
during hospitalization. SUBJECTS AND SETTING: Eighty-three consecutive stroke
patients under the age of 50 admitted to a Canadian tertiary-care hospital
rehabilitation unit. MAIN OUTCOME MEASURES: Discharge destination and primary
caregiver at discharge, and return to work and marital separation 3 months after
rehabilitation discharge. RESULTS: Of the 55 patients with spouses, 8 (14.5%)
separated within 3 months of hospital discharge. Fifteen of the 83 patients
(18.1%) were not able to return to their premorbid place of residence; 4 (4.8%)
required institutionalization. Of the 64 patients employed outside the home or
studying at the time of their stroke, only 13 (20.3%) were able to return to work
within 3 months of their discharge to home. Only 9.4% of those working full-time
were able to return to full-time employment. CONCLUSIONS: Rehabilitation of young
stroke patients is associated with a variety of social problems, including
marital breakup, child care responsibilities, and return to employment, which are
uniquely important in this age group.
PMID- 10668777
TI - Joint position during anterior-posterior glide mobilization: its effect on
glenohumeral abduction range of motion.
AB - OBJECTIVE: To investigate the effect of joint position during an anterior
posterior glide (APG) procedure on the range of motion (ROM) of glenohumeral
abduction in cadaver specimens. DESIGN: Mechanical simulation of APG mobilization
and abduction torque ROM measurement of the glenohumeral joint with a material
testing system. The immediate mechanical efficacy of APG was compared in two
groups of specimens at two different joint positions: midrange (n = 5) and end
range (n = 6) of glenohumeral abduction. SETTING: Biomechanics laboratory.
SPECIMENS: Eleven fresh cadaver shoulder specimens (mean age, 66.9+/-2.5 yrs).
MAIN OUTCOME MEASURE: Improvement in glenohumeral abduction torque ROM obtained
before and after APG procedure. RESULTS: Glenohumeral abduction improved
significantly, as indicated by a significant increase (Kruskal-Wallis statistics,
chi2 = 7.50, p = .006) in the torque ROM of the end range group (mean +/-
standard error of the mean, 2.02 degrees +/- .20 degrees) over the midrange group
(.64 degrees +/- .08 degrees). A significant difference in the magnitude of peak
displacement of the humeral head between midrange (14.44+/-3.56 mm) and end range
(3.19+/-.81 mm) groups was also found (Mann-Whitney test, p < .030). CONCLUSION:
This study demonstrated that APG technique performed at close to the end of the
range of abduction is more effective in improving glenohumeral abduction ROM than
that performed at the middle of the range of abduction.
PMID- 10668778
TI - Clinical tests of standing balance: performance of persons with multiple
sclerosis.
AB - OBJECTIVE: To investigate differences in performance between people with multiple
sclerosis (MS) and control subjects on clinical tests of balance, and to assess
performance consistency on balance tests in people with MS from morning to
afternoon. STUDY DESIGN: Two factor repeated measures design with a two group
sample of convenience. SETTING: Kingston Centre and the Camberwell Centre of the
MS Society of Victoria, Australia. SUBJECTS: Fourteen people with MS and 14
control subjects matched for age, height, and sex. MAIN OUTCOME MEASURES:
Subjects were measured on their ability to maintain standing balance in steady
stance, (feet apart, feet together, stride stance, tandem stance, and single leg
stance), during self-generated perturbations (functional reach, arm raise, and
step tests) and in response to an external perturbation. Participants with MS
were also asked to rate their fatigue level in the morning and afternoon.
RESULTS: There were no differences between MS and control groups on the ability
to maintain standing balance with feet apart, feet together, or in stride stance.
Participants with MS performed more poorly than control subjects in tandem stance
and single leg stance and in the functional reach test, arm raise test, step
test, and in response to an external perturbation. There was little change in
balance from morning to afternoon in participants with MS (ICCs (2,1) .70 to
.94), despite an increase in self-rated fatigue (t(14) = -3.14, p = .008).
CONCLUSION: The ability to maintain balance in standing is a marked problem in
people with MS despite the consistency of their performance from morning to
afternoon.
PMID- 10668779
TI - Catecholamine-induced hypertension in lumbosacral paraplegia: five case reports.
AB - Hypertension in the patient with SCI is relatively rare and generally restricted
to patients with high-level injuries where autonomic dysreflexia can occur.
Resting blood pressure in individuals with SCI has been described as lower than
that in the normal population. This report describes five previously normotensive
teenagers with subsequent paraplegia as a result of gunshot wounds who presented
with hypertension secondary to idiopathic elevation of plasma or urinary
catecholamine levels. A clonidine suppression test was used as a neuroprobe to
inhibit centrally mediated sympathetic outflow, excluding the probability of an
extra-axial autonomous catecholamine-secreting tumor as the possible source of
hypertension. Positive suppression was achieved in four patients (41%, 37.2%,
4.8%, and 37.2% decreases). One patient had values corresponding to orthostatic
changes (an increase of 63%) because of poor compliance with the test. This
patient was lost to follow-up; in the remaining four, hypertension resolved at
12, 8, 9, and 6 weeks postinjury. The increased circulating catecholamine level
appears to be promoted by a centrally mediated response to the SCI. Elevated
blood pressure probably results from an upgraded receptor regulation or an
increased receptor sensitivity on the affected cells in the absence of
restraining spinal reflexes. The pathophysiology of such hypertension seems to be
secondary to autonomic dysfunction and, although it may be transient, it should
be treated promptly and reevaluated periodically until stabilization is achieved.
PMID- 10668780
TI - Aerobic training in a patient with nonsevere aplastic anemia: a case report.
AB - This case report examined whether a 26-year-old man with a 5-year history of
nonsevere aplastic anemia could perform aerobic training and whether exercise was
beneficial. Testing was performed at baseline and at 8 and 16 weeks and included
complete blood tests, graded exercise tests with breath-by-breath gas analyses,
and health status assessment with the Medical Outcomes Survey SF-12 health
survey. Training consisted of treadmill walking for 25 minutes, 3 days a week for
16 weeks, at 75% of maximal heart rate. The patient successfully completed 16
weeks of training and had no adverse effects from testing or training. Training
did not produce changes in disease-related measures (hematologic values) or
impairment measures (cardiopulmonary measures of fitness). The mental component
of the SF-12 improved from below 2 standard deviations from the population mean
to within 1 standard deviation of the population mean. The benefits of aerobic
training for this person with aplastic anemia were that he showed that he could
participate in aerobic-type activities and that training appeared to improve his
mental health.
PMID- 10668781
TI - Cardiopulmonary rehabilitation in a patient with Noonan syndrome.
AB - Noonan syndrome, an autosomal dominant disease occurring with an incidence of 1
in 1,000 to 1 in 2,500 live births, is characterized by its particular
cardiovascular abnormalities, including pulmonic valve stenosis, pulmonary artery
stenosis, and, more rarely, septal defects and coarctation of the aorta. The case
of a 20-year-old man admitted for inpatient cardiopulmonary rehabilitation after
pulmonic valve repair, left pulmonary artery angioplasty, and pectus excavatum
repair is presented. His endurance was markedly decreased, thus limiting his
ability to perform activities of daily living and reducing his exercise
tolerance. With participation in a comprehensive cardiopulmonary rehabilitation
program, he experienced marked improvement with independence in his activities of
daily living and an increase in his metabolic equivalent levels from to 2.8 to
5.4. After inpatient rehabilitation, he underwent left pulmonary stent placement
before being discharged home. Subsequent outpatient cardiopulmonary
rehabilitation has continued to improve significantly his overall exercise
tolerance. Given that Noonan syndrome is viewed as the most common syndrome
associated with congenital heart disease after Down syndrome, physiatrists must
be familiar with its presentation, its associated abnormalities, and the
treatment approach to optimize the patient's cardiopulmonary, musculoskeletal,
and psychological status.
PMID- 10668782
TI - The rehabilitation marketplace: economics, values, and proposals for reform.
AB - This article examines whether the ideals, goals, and values of medical
rehabilitation can be realized in a market-based health care system. The article
observes that rehabilitation is greatly disadvantaged in today's health care
marketplace, which violates virtually all the assumptions of a perfectly
competitive one. Nevertheless, the authors argue that rehabilitation goals and
market economics are not inherently incompatible and call for several market
reforms that are congruent with both rehabilitation goals and market theory.
These reforms will clarify and facilitate providers' fiduciary responsibilities
to patients as well as their accountability to payers. The authors conclude that
while the marketplace is an inevitable medium for realizing rehabilitation goals,
the vision and value of rehabilitation will not derive from the internal workings
of the marketplace but ultimately from committed individuals and socially
responsible institutions outside the marketplace.
PMID- 10668783
TI - Muscle strength and vitamin D.
PMID- 10668784
TI - Wheelchair spotter straps.
PMID- 10668785
TI - Duplex ultrasound screening.
PMID- 10668786
TI - Upregulation of L-plastin gene by testosterone in breast and prostate cancer
cells: identification of three cooperative androgen receptor-binding sequences.
AB - L-Plastin is normally a leukocyte-specific actin-binding protein; it is also
expressed in the majority of human cancer cell lines that are derived from many
types of solid tumors. We have previously reported the isolation of the L-plastin
gene promoter, in which we identified several potential steroid receptor-binding
sequences. We now obtained evidence that L-plastin gene expression was positively
regulated by testosterone in androgen receptor (AR)-positive prostate and breast
cancer cells. DNase I footprint analysis identified three AR-binding elements
(ARE) located in a 545-bp region approximately 1.1 kb upstream from the
transcription initiation site. However, each of these three AREs exhibited very
little testosterone/AR-responsive enhancer activities toward a test promoter (of
the thymidine kinase gene) when tested in MCF-7 breast cancer cells. Their
testosterone/AR responsiveness became evident only when two or three of them were
combined. In PC-3 prostate cancer cells, cooperation among L-plastin AREs was
still evident although individually they had moderate levels of testosterone/AR
responsiveness. Thus, the three L-plastin AREs, despite their imperfect sequences
compared with the consensus ARE, could cooperate with each other to become a
potent testosterone/AR-responsive unit, which was likely responsible for the
inducibility of the L-plastin gene by testosterone.
PMID- 10668787
TI - C/EBPalpha is required to maintain postmitotic growth arrest in adipocytes.
AB - Terminal differentiation is often coupled with irreversible loss of proliferative
potential. The CCAAT enhancer binding protein alpha (C/EBPalpha) preferentially
accumulates in postmitotic, differentiated 3T3-L1 adipocytes but declines during
tumor necrosis factor alpha (TNFalpha)-induced dedifferentiation. We have
discovered that this decline in C/EBPalpha correlates with an increased mitotic
growth potential. In order to further investigate the antimitotic activity of
C/EBPalpha, we introduced antisense C/EBPalpha RNA into 3T3-L1 cells to block
endogenous C/EBPalpha expression. When treated according to the standard
differentiation protocol, stable cells lines harboring antisense C/EBPalpha RNA
did not differentiate into fat-laden adipocytes, consistent with previous
findings (Lin F, Lane MD, Genes Dev 1992;6:533-544). We found that these
undifferentiated cells expressing antisense-C/EBPalpha can reenter the cell cycle
after mitogenic stimulation at a time in development when parental 3T3-L1 cells
cannot. Moreover, the expression profiles of the growth-arrest-associated genes
gas1 and gas2 revealed that the antisense C/EBPalpha-expressing cells withdrew
from the cell cycle after the period of clonal expansion but failed to progress
to the state of least proliferative potential characteristic of terminally
differentiated adipocytes.
PMID- 10668788
TI - Kappa opioid receptor endocytosis by dynorphin peptides.
AB - Internalization and downregulation are important steps in the modulation of
receptor function. Recent work with the beta2 adrenergic and opioid receptors
have implicated these processes in receptor-mediated activation of mitogen
activated protein kinase (MAPK). We have used CHO cells expressing epitope-tagged
rat kappa opioid receptors (rKORs) and prodynorphin-derived peptides to
characterize the agonist-mediated endocytosis of rKORs and activation of MAPK.
Kappa receptor-selective peptides induced receptor internalization and
downregulation whereas nonpeptide agonists did not. An examination of the ability
of dynorphin A-17-related peptides (lacking C-terminal amino acids) to promote
KOR internalization, inhibition of adenylyl cyclase, and MAPK phosphorylation
revealed that the N-terminal seven residues play an important role in eliciting
these responses. Both dynorphin peptides and nonpeptide agonists induced rapid
and robust phosphorylation of MAPKs. Taken together, these results point to a
difference in the ability of dynorphin peptides and nonpeptide ligands to promote
rKOR endocytosis and support the view that rKOR internalization is not required
for MAPK activation.
PMID- 10668789
TI - Gamma-radiation-induced growth arrest and apoptosis in p53-null lymphoma cells is
accompanied by modest transcriptional changes in many genes.
AB - Damage to DNA produces cell cycle arrest, apoptosis, or both. The response in
cells with p53 tumor suppressor function involves transcriptional changes, but
whether that holds for cells lacking active p53, as in most tumors, is not known.
Better characterization of the DNA damage response in tumors lacking p53 function
is relevant to cytotoxic therapy. We have explored whether gamma-irradiated p53
null mouse T lymphoma cells undergo marked changes in transcription. Their arrest
in G2/M prior to apoptosis required transcription. Transcripts whose abundance
altered on irradiation were sought by subtractive hybridization, and 1010
candidate clones from two oppositely enriched cDNA populations were sequenced.
Hybridization revealed small (<3-fold) increases or decreases in the transcripts
of more than 15 genes, including some implicated in cell cycle control (e.g.,
BTG, Bap1) or apoptosis (e.g., STAT1, calpain), but no marked changes like those
associated with other forms of T-cell death. Moreover, the expression of some
critical apoptosis regulators, such as Bcl-2 family members, did not change.
Hence, the G2/M arrest and apoptosis in the irradiated p53-null lymphoma appears
to involve modest expression changes for many genes, but post-transcriptional
alterations may be more critical.
PMID- 10668790
TI - Downstream sequence adjacent to AUG affects translation of chloramphenicol acetyl
transferase in eukaryotic cells.
AB - The CAT gene is widely used as a reporter in eukaryotic systems because of the
efficient translation of its mRNA. We report here that a sequence occurring in
the CAT mRNA at +15 nucleotides from CAT AUG is essential for translation. This
sequence includes a stem-loop structure, which, however, exhibits a calculated
stability significantly lower than that required for a hairpin to act as an
enhancer of translation in vitro. Replacement of this region with the
corresponding sequence from mRNAs that are normally translated in eukaryotic
systems drastically reduced translation of CAT in COS cells, although the
consensus sequence around the AUG, known to be required for high-level
translation initiation, was conserved. These observations may be relevant for the
exploitation of the CAT reporter system for analysis of the mechanisms of
translation initiation by means of fusion constructs.
PMID- 10668791
TI - Molecular characterization of KMP11 from Trypanosoma cruzi: a cytoskeleton
associated protein regulated at the translational level.
AB - Kinetoplasmid membrane protein-11 (KMP11) is present in a wide range of
trypanosomatids. In the present paper, we show that the T. cruzi KMP11 gene is
organized in a cluster formed by four gene units arranged in a head-to-tail
tandem manner located on a chromosome of about 1900 kb. Northern blot analyses
indicated that the steady-state level of mature KMP11 transcripts of 0.52 kb is
high and similar in the three forms of the parasite. The KMP11 mRNAs have a half
life of about 16 h whose steady-state level is strongly downregulated when the
parasites reach the stationary growth phase. The T. cruzi KMP11 sequence presents
a significant homology with the amino-terminal third of the cytoskeleton
associated protein CIP1 from Arabidopsis thaliana. Western blot and
immunoelectron microscopy studies showed that KMP11 is present in the
cytoskeleton structure. Because the strong downregulation observed in the de novo
synthesis of KMP11 protein in parasites treated with vinblastine is not
accompanied by a significant fall in the steady-state level of KMP11 mRNAs,
regulatory control of the protein at the translational level is suggested.
PMID- 10668792
TI - Atlantic salmon HNF-3/forkhead: cDNA sequence, evolution, expression, and
functional analysis.
AB - We report the isolation and characterization of a cDNA encoding an HNF-3 family
member (as HNF-3) from Atlantic salmon (Salmo salar L). The important functional
domains of HNF-3 proteins that have been characterized previously are revealed by
segments of high identity along the alignment of the asHNF-3 with winged
helix/forkhead amino acid sequences isolated from other species. A comparison of
asHNF-3 cDNA and genomic DNA indicated that there were no introns present in the
asHNF-3 gene. Expression of asHNF-3 protein in adult salmon tissues was not
exclusive to liver but was also present in the pancreas and intestine. An RT-PCR
analysis performed on salmon development showed that asHNF3 expression is
detectable before gastrulation at the mid blastula transition stage. Functional
analysis of the asHNF-3 protein using a characterized HNF-3 consensus binding
site demonstrated that the protein can recognize and bind to specific HNF-3
consensus sequences. We also report the identification of a novel HNF3 binding
site in the promoter of the Atlantic salmon transferrin gene.
PMID- 10668793
TI - mRNA surveillance in mammalian cells: the relationship between introns and
translation termination.
PMID- 10668794
TI - On the wobble GoU and related pairs.
AB - The wobble GoU pairs have been implicated in several biological processes where
RNA molecules play a key role. We review the geometrical and conformational
properties of wobble GoU pairs on the basis of available crystal structures of
RNAs at high resolution. The similarities with the wobble A+oC pairs and UoU
pairs are illustrated, while the differences with the recently discovered
bifurcated G x U pairs are contrasted.
PMID- 10668795
TI - Bimolecular exon ligation by the human spliceosome bypasses early 3' splice site
AG recognition and requires NTP hydrolysis.
AB - Here we report further characterization of an in vitro assay system for exon
ligation by the human spliceosome in which the 3' splice site AG is supplied by a
different RNA molecule than that containing the 5' splice and branch sites. By
varying the time during splicing reactions when the 3' splice site AG is made
available to the splicing machinery, we show that AG recognition need not occur
until after lariat formation. Thus an early AG recognition event required for
spliceosome formation and lariat formation on some mammalian introns is not
required for exon ligation. Depletion/add-back studies and cold competitor
challenge experiments reveal that commitment of a 3' splice site AG to exon
ligation requires NTP hydrolysis. Because it both physically and kinetically
uncouples exon ligation from spliceosome assembly and lariat formation, the
bimolecular system will be a valuable tool for further mechanistic analysis of
the second step of splicing.
PMID- 10668796
TI - Organization of the 16S rRNA around its 5' terminus determined by photochemical
crosslinking in the 30S ribosomal subunit.
AB - The organization of the 5' terminus region in the 16S rRNA was investigated using
a series of RNA constructs in which the 5' terminus was extended by 5 nt or was
shortened to give RNA molecules that started at positions -5, +1, +5, +8, +14, or
+21. The structural and functional effects of the 5' extension/truncations were
determined after the RNAs were reconstituted. 30S subunits containing 16S rRNA
with 5' termini at -5, +1, +5, +8 and +14 had similar structures (judged by UV
induced crosslinking) and exhibited a gradual reduction in tRNA binding activity
compared to that seen with 30S subunits reconstituted with native 16S rRNA. To
create the 5' terminal site-specific photocrosslinking agent, the reagent
azidophenacylbromide (APAB) was attached to the 5' terminus of 16S rRNA through a
guanosine monophosphorothioate and the APA-16S rRNAs were reconstituted.
Crosslinking carried out with the APA revealed sites in six regions around
positions 300-340, 560, 900, 1080, the 16S rRNA decoding region, and at 1330.
Differences in the pattern and efficiency of crosslinking for the different
constructs allow distance estimates for the crosslinked sites from nucleotide G9.
These measurements provide constraints for the arrangement of the RNA elements in
the 30S subunit. Similar experiments carried out in the 70S ribosome resulted in
a five- to tenfold lower frequency of crosslinking. This is most likely due to a
repositioning of the 5' terminus upon subunit association.
PMID- 10668797
TI - Specific HDV RNA-templated transcription by pol II in vitro.
AB - RNA polymerase II is implicated in the RNA-templated RNA synthesis during
replication of viroids and Hepatitis Delta Virus (HDV); however, neither the RNA
template nor protein factor requirements for this process are well defined. We
have developed an in vitro transcription system based on HeLa cell nuclear
extract (NE), in which a segment of antigenomic RNA corresponding to the left
hand tip region of the HDV rod-like structure serves as a template for efficient
and highly specific RNA synthesis. Accumulation of the unique RNA product is
highly sensitive to alpha-amanitin in HeLa NE and only partially sensitive to
this drug in NE from PMG cells that contain an allele of the alpha-amanitin
resistant subunit of pol II, strongly suggesting pol II involvement in this
reaction. Detailed analysis of the RNA product revealed that it represents a
chimeric molecule composed of a newly synthesized transcript covalently attached
to the 5' half of the RNA template. Selection of the start site for transcription
is remarkably specific and depends on the secondary structure of the RNA
template, rather than on its primary sequence. Some features of this reaction
resemble the RNA cleavage-extension process observed for pol II-arrested
complexes in vitro. A possible involvement of the described reaction in HDV
replication is discussed.
PMID- 10668798
TI - A DNA target of 30 bp is sufficient for RNA-directed DNA methylation.
AB - In higher plants, RNA-DNA interactions can trigger de novo methylation of genomic
sequences via a process that is termed RNA-directed DNA methylation (RdDM). In
potato spindle tuber viroid (PSTVd)-infected tobacco plants, this process can
potentially lead to methylation of all C residues at symmetrical and
nonsymmetrical sites within chromosomal inserts that consist of multimers of the
359-bp-long PSTVd cDNA. Using PSTVd cDNA subfragments, we found that genomic
targets with as few as 30 nt of sequence complementarity to the viroid RNA are
detected and methylated. Genomic sequencing analyses of genome-integrated 30- and
60-bp-long PSTVd subfragments demonstrated that de novo cytosine methylation is
not limited to the canonical CpG, CpNpG sites. Sixty-base-pair-long PSTVd cDNA
constructs appeared to be densely methylated in nearly all tobacco leaf cells.
With the 30-bp-long PSTVd-specific construct, the proportion of cells displaying
dense transgene methylation was significantly reduced, suggesting that a minimal
target size of about 30 bp is necessary for RdDM. The methylation patterns
observed for two different 60-bp constructs further suggested that the sequence
identity of the target may influence the methylation mechanism. Finally, a link
between viroid pathogenicity and PSTVd RNA-directed methylation of host sequences
is proposed.
PMID- 10668800
TI - Expanded CUG repeat RNAs form hairpins that activate the double-stranded RNA
dependent protein kinase PKR.
AB - Myotonic dystrophy is caused by an expanded CTG repeat in the 3' untranslated
region of the DM protein kinase (DMPK) gene. The expanded repeat triggers the
nuclear retention of mutant DMPK transcripts, but the resulting underexpression
of DMPK probably does not fully account for the severe phenotype. One proposed
disease mechanism is that nuclear accumulation of expanded CUG repeats may
interfere with nuclear function. Here we show by thermal melting and nuclease
digestion studies that CUG repeats form highly stable hairpins. Furthermore, CUG
repeats bind to the dsRNA-binding domain of PKR, the dsRNA-activated protein
kinase. The threshold for binding to PKR is approximately 15 CUG repeats, and the
affinity increases with longer repeat lengths. Finally, CUG repeats that are
pathologically expanded can activate PKR in vitro. These results raise the
possibility that the disease mechanism could be, in part, a gain of function by
mutant DMPK transcripts that involves sequestration or activation of dsRNA
binding proteins.
PMID- 10668799
TI - Interaction cloning and characterization of RoBPI, a novel protein binding to
human Ro ribonucleoproteins.
AB - Human Ro ribonucleoproteins (RNPs) are autoantigenic particles of unknown
function(s) that consist of a 60-kDa protein (Ro60) associated with one hY RNA
(hY1-5). Using a modified yeast three-hybrid system, named RNP interaction trap
assay (RITA), we cloned a novel Ro RNP-binding protein (RoBPI), based on its
property to interact in vivo in yeast with an RNP complex made of recombinant
Ro60 (rRo60) protein and hY5 (rhY5) RNA. RoBPI cDNA contains three conserved RNA
recognition motifs (RRM) and is present as a family of isoforms differing
slightly at their 5' end. The 2.0-kb RoBPI mRNA was detected in all human tissues
tested. Highly homologous cDNA sequences were found in banks of expressed
sequence tags (ESTs) from mice. Two-hybrid, three-hybrid, and RITA experiments
respectively established that 60 kDa RoBPI did not interact in yeast with rRo60
alone, with rhY5 RNA alone, or with bait RNPs consisting of rRo60 and recombinant
hY1, hY3, or hY4 RNAs. RoBPI coimmunoprecipitated with Ro RNPs from HeLa cell
extracts and partially colocalized with Ro60 in nuclei of cultured cells. Because
hY5 RNA and RohY5 RNPs are recent evolutionary additions seen only in primates,
but RoBPI seems more conserved, their interaction may represent a gain of
function for Ro RNPs. Alternatively, interaction of RohY5 RNPs with RoBPI may
have no functional bearing, but may underlie some of the unique biochemical and
immunological properties of these RNPs.
PMID- 10668801
TI - Fibrillarin binds directly and specifically to U16 box C/D snoRNA.
AB - Eukaryotic nucleoli contain a large family of box C/D small nucleolar
ribonucleoprotein complexes (snoRNPs) that are involved in processing and site
specific methylation of pre-rRNA. Several proteins have been reported to be
common factors of box C/D snoRNPs in lower and higher eukaryotes; nevertheless
none of them has been clearly shown to directly interact with RNA. We previously
identified in Xenopus laevis, by means of UV crosslinking in vivo, two proteins
associated with box C/D snoRNAs, fibrillarin and p68. Here we show that
fibrillarin interacts directly and specifically with the U16 box C/D snoRNA in a
X. laevis oocyte nuclear extract and that it does not require p68 for binding.
Specific binding is also obtained with a recombinant fibrillarin demonstrating
that the protein is able to bind directly and specifically to U16 snoRNA by
itself.
PMID- 10668802
TI - Structural requirement for the two-step dimerization of human immunodeficiency
virus type 1 genome.
AB - Generation of RNA dimeric form of the human immunodeficiency virus type 1 (HIV-1)
genome is crucial for viral replication. The dimerization initiation site (DIS)
has been identified as a primary sequence that can form a stem-loop structure
with a self-complementary sequence in the loop and a bulge in the stem. It has
been reported that HIV-1 RNA fragments containing the DIS form two types of
dimers, loose dimers and tight dimers. The loose dimers are spontaneously
generated at the physiological temperature and converted into tight dimers by the
addition of nucleocapsid protein NCp7. To know the biochemical process in this
two-step dimerization reaction, we chemically synthesized a 39-mer RNA covering
the entire DIS sequence and also a 23-mer RNA covering the self-complementary
loop and its flanking stem within the DIS. Electrophoretic dimerization assays
demonstrated that the 39-mer RNA reproduced the two-step dimerization process,
whereas the 23-mer RNA immediately formed the tight dimer. Furthermore, deletion
of the bulge from the 39-mer RNA prevented the NCp7-assisted tight-dimer
formation. Therefore, the whole DIS sequence is necessary and sufficient for the
two-step dimerization. Our data suggested that the bulge region regulates the
stability of the stem and guides the DIS to the two-step dimerization process.
PMID- 10668803
TI - In vivo misreading by tRNA overdose.
AB - Rpb5-H147R is an AT-GC transition replacing CAC(His) by CGC(Arg) at a conserved
and critical position of ABC27 (Rpb5p), one of the five common and essential
subunits shared by all three eukaryotic RNA polymerases. This mutation is viable
at 25 degrees C, but has a lethal phenotype at 34 degrees C. A search for dosage
dependent suppressors identified five distinct clones that all bear a copy of the
tRNA(His)GUG gene. Suppression was also observed with a small genomic insert
bearing this tRNA gene and no other coding sequences, under conditions where
there is a sevenfold increase in the cellular concentration of tRNA(His)GUG.
Overexpressing tRNA(Arg)ICG, which normally decodes the suppressed CGC codon,
counteracted suppression. Suppression is codon specific because it was abolished
when replacing CGC by its synonymous codons CGA, CGU, or AGA, but was not
detectably affected by several nucleotide substitutions modifying the surrounding
sequence and is thus largely insensitive to the nucleotide context. It is
proposed that overexpressing tRNA(His)GUG extends its decoding properties from
CAC(His) to the noncognate CGC(Arg) codon through an illegitimate U x G pairing
at the middle base of the anticodon. Accordingly, tRNA(His)GUG would compete with
tRNA(Arg)ICG for chain elongation and generate a significant level of misreading
errors under normal growth conditions.
PMID- 10668804
TI - The SRm160/300 splicing coactivator subunits.
AB - The SRm160/300 splicing coactivator, which consists of the serine/arginine (SR)
related nuclear matrix protein of 160 kDa and a 300-kDa nuclear matrix antigen,
functions in splicing by promoting critical interactions between splicing factors
bound to pre-mRNA, including snRNPs and SR family proteins. In this article we
report the isolation of a cDNA encoding the 300-kDa antigen and investigate the
activity of it and SRm160 in splicing. Like SRm160, the 300-kDa antigen contains
domains rich in alternating S and R residues but lacks an RNA recognition motif;
the protein is accordingly named "SRm300." SRm300 also contains a novel and
highly conserved N-terminal domain, several unique repeated motifs rich in S, R,
and proline residues, and two very long polyserine tracts. Surprisingly, specific
depletion of SRm300 does not prevent the splicing of pre-mRNAs shown previously
to require SRm160/300. Addition of recombinant SRm160 alone to SRm160/300
depleted reactions specifically activates splicing. The results indicate that
SRm160 may be the more critical component of the SRm160/300 coactivator in the
splicing of SRm160/300-dependent pre-mRNAs.
PMID- 10668805
TI - Mitochondrial minicircles in the free-living bodonid Bodo saltans contain two
gRNA gene cassettes and are not found in large networks.
AB - In trypanosomatids, the majority of the guide (g) RNAs that provide the
information for U-insertion/deletion RNA editing are encoded by minicircles that
are catenated into large networks. In contrast, in the distantly related
cryptobiid Trypanoplasma borreli, gRNA genes appear to reside in large 180-kb
noncatenated DNA circles. To shed light on the evolutionary history and function
of the minicircle network, we have analyzed minicircle organization in the free
living bodonid Bodo saltans, which is more closely related to trypanosomatids
than T. borreli. We identified 1.4-kb circular DNAs as the B. saltans equivalent
of minicircles via sequence analysis of 4 complete minicircles, 14 minicircle
fragments, and 14 gRNAs. We show that each minicircle harbors two gRNA gene
cassettes of opposite polarity residing in variable regions of about 200 nt in
otherwise highly conserved molecules. In the conserved region, B. saltans
minicircles contain a putative bent helix sequence and a degenerate dodecamer
motif (CSB-3). Electron microscopy, sedimentation, and gel electrophoresis
analyses showed no evidence for the existence of large minicircle networks in B.
saltans, the large majority of the minicircles being present as circular and
linear monomers (85-90%) with small amounts of catenated dimers and trimers. Our
results provide the first example of a kinetoplastid species with noncatenated,
gRNA gene-containing minicircles, which implies that the creation of minicircles
and minicircle networks are separate evolutionary events.
PMID- 10668807
TI - Strategies for the diagnosis of deep vein thrombosis and pulmonary embolism.
PMID- 10668806
TI - The C-terminal domain of TAP interacts with the nuclear pore complex and promotes
export of specific CTE-bearing RNA substrates.
AB - Messenger RNAs are exported from the nucleus as large ribonucleoprotein complexes
(mRNPs). To date, proteins implicated in this process include TAP/Mex67p and
RAE1/Gle2p and are distinct from the nuclear transport receptors of the beta
related, Ran-binding protein family. Mex67p is essential for mRNA export in
yeast. Its vertebrate homolog TAP has been implicated in the export of cellular
mRNAs and of simian type D viral RNAs bearing the constitutive transport element
(CTE). Here we show that TAP is predominantly localized in the nucleoplasm and at
both the nucleoplasmic and cytoplasmic faces of the nuclear pore complex (NPC).
TAP interacts with multiple components of the NPC including the nucleoporins CAN,
Nup98, Nup153, p62, and with three major NPC subcomplexes. The nucleoporin
binding domain of TAP comprises residues 508-619. In HeLa cells, this domain is
necessary and sufficient to target GFP-TAP fusions to the nuclear rim. Moreover,
the isolated domain strongly competes multiple export pathways in vivo, probably
by blocking binding sites on the NPC that are shared with other transport
receptors. Microinjection experiments implicate this domain in the export of
specific CTE-containing RNAs. Finally, we show that TAP interacts with
transportin and with two proteins implicated in the export of cellular mRNAs:
RAE1/hGle2 and E1B-AP5. The interaction of TAP with nucleoporins, its direct
binding to the CTE RNA, and its association with two mRNP binding proteins
suggest that TAP is an RNA export mediator that may bridge the interaction
between specific RNP export substrates and the NPC.
PMID- 10668808
TI - Prevention of venous thromboembolism.
AB - Venous thromboembolism is the most common cause of preventable death among
hospitalised patients. Systematic prophylaxis with antithrombotic agents in
patients at risk for venous thromboembolism is the most effective approach to
reduce morbidity and mortality. Despite this evidence, antithrombotic prophylaxis
is still underused, due to the underestimation of incidence of venous
thromboembolism and to the unjustified fear of bleeding complications. Both the
characteristics of the individual patient and the clinical setting contribute to
the definition of the risk for venous thromboembolism. Patient-related risk
factors include clinical and molecular abnormalities. The grade of risk for
venous thromboembolism is defined better by the clinical setting than by the
patient characteristics. Prophylactic studies have been extensively carried out
in surgical patients and, only more recently, in medical patients. Prophylactic
methods include pharmacological agents, such as heparin, low molecular weight
heparins, warfarin, and hirudin, as well as mechanical methods such as
compression stockings and intermittent pneumatic compression.
PMID- 10668809
TI - Treatment of venous thromboembolism.
AB - The combination of heparin and oral anticoagulants has been the treatment of
choice for most patients with venous thromboembolism in the last two decades.
Heparin has been proven to be effective when administered by intravenous
continuous infusion or by subcutaneous injection. Oral anticoagulants should be
started at the same time and heparin should be discontinued when the levels of
the International Normalized Ratio reach the therapeutic range, between 2.0 and
3.0. Low molecular weight heparin has potential advantages over heparin and can
be administered in subcutaneous weight-adjusted fixed doses without need for
monitoring. This has made home treatment of a large proportion of patients
possible. Randomized clinical trials have demonstrated the efficacy and safety of
this approach. The optimal duration of the secondary prophylaxis with oral
anticoagulants is still a matter of debate. The rate of recurrence has been shown
to be elevated, particularly in those patients with idiopathic venous
thromboembolism. The presence of an active cancer or a thrombophilic state may
require long-term anticoagulation, although not all the congenital
hypercoagulable states seem to carry the same level of risk. A 3-month therapy is
recommended when a transient risk factor is identified; lifelong treatment is
recommended for patients with a second episode of venous thromboembolism. In all
other cases, 6 months are currently recommended, but thereafter close monitoring
of the patients is advisable. The use of different treatment strategies such as
vena caval filter placement, thrombolysis, and surgical thrombectomy should be
restricted to a limited number of situations.
PMID- 10668810
TI - Companion animal medicine in the age of medical genetics.
PMID- 10668811
TI - Mutation causing von Willebrand's disease in Scottish Terriers.
AB - Von Willebrand's Disease (vWD) in the Scottish Terrier breed is a serious, often
fatal, hereditary bleeding disorder. Elimination of the mutated gene by selective
breeding is an important goal for the health of this breed. Although the standard
protein-based tests are accurate for identification of affected Scottish
Terriers, they are not reliable for the identification of carriers of the mutant
gene unless multiple replicate assays are performed. A simple, highly accurate
test for carriers of the disease is needed so that veterinarians can counsel
clients on which animals to use in their breeding programs. The complete coding
region of von Willebrand factor (vWF) complementary DNA (cDNA) was sequenced from
an affected animal, and a single base deletion in the codon for amino acid 85 of
the prepro-vWF cDNA that leads to Scottish Terrier vWD was identified. A highly
accurate polymerase chain reaction assay was developed that can distinguish
homozygous normal animals from those that are homozygous affected or
heterozygous. In a voluntary survey of 87 animals provided by Scottish Terrier
owners, 15 were carriers and 4 were affected with vWD, 2 of which had previously
been shown to have undetectable vWF. The determination of the complete canine vWF
cDNA sequence should facilitate the identification of additional vWD alleles in
other breeds and other species.
PMID- 10668812
TI - Metabolic and hormonal alterations in cats with hepatic lipidosis.
AB - Hepatic lipidosis in cats is a commonly diagnosed hepatobiliary disease of
unknown cause. The purpose of this prospective study was to characterize the
blood hormone and lipid status of cats with hepatic lipidosis, and to compare
this status to that of cats with other types of liver disease and to control
cats. Twenty-three cats with hepatic disease were assigned to 1 of 2 groups on
the basis of cytopathologic or histopathologic examination of the liver: group 1,
hepatic lipidosis (n = 18); or group 2, cholangiohepatitis (n = 5). Ten healthy
young adult cats were used as controls. Food was withheld from control animals
for 24 hours before blood collection. Concentrations of plasma glucagon and serum
insulin, cortisol, thyroxine, triglycerides, cholesterol, phospholipids, and
nonesterified fatty acids (NEFAs) were determined in all cats, in addition to
routine hematologic and serum biochemical testing. Cats with hepatic lipidosis
had higher serum NEFA concentrations than cats with cholangiohepatitis or control
cats (P < .05). Cats with cholangiohepatitis had higher serum cholesterol and
phospholipid concentrations than those of cats with lipidosis or control cats (P
< .05); their plasma glucagon concentrations were higher than those of control
cats (P < .05), but were not different from those of cats with hepatic lipidosis.
Serum insulin concentrations were significantly higher in control cats than in
diseased cats (P < .05), but neither serum insulin nor the insulin to glucagon
ratio was significantly different among the cats with hepatic disease. The high
concentration of NEFAs in cats with hepatic lipidosis suggests that at least 1
factor in the pathogenesis of this syndrome may involve the regulation of hormone
sensitive lipase.
PMID- 10668813
TI - Treatment of chronic idiopathic large-bowel diarrhea in dogs with a highly
digestible diet and soluble fiber: a retrospective review of 37 cases.
AB - The medical records of 37 dogs diagnosed with chronic idiopathic large-bowel
diarrhea were reviewed. The median age of affected dogs was 6 years. The median
body weight was 13.9 kg. The median duration of clinical signs before diagnosis
was 32 weeks. Diarrhea usually was intermittent and characterized by increasing
frequency, fecal mucus, hematochezia, and tenesmus. Vomiting was common but
usually much less frequent and severe than the diarrhea. A variety of stressful
factors and abnormal personality traits were identified. CBC and serum
biochemistry usually were normal. Fecal examination rarely identified parasites.
Rectal cytology specimens were most often normal, but some dogs had increased
numbers of neutrophils. The colonic mucosa often was normal during colonoscopy,
but decreased numbers of lymphoid follicles were found in some dogs.
Histopathologic evaluation found that colonic mucosa was within normal limits.
Treatment with soluble fiber (Metamucil) added to a highly digestible diet (Hills
i/d) resulted in a very good to excellent response in most dogs. The median
initial dosage of Metamucil was 2 tablespoons (2 T) per day. In some dogs, the
fiber dosage was reduced or eliminated, or a grocery store brand of dog food was
substituted, without causing diarrhea to return.
PMID- 10668814
TI - Gastric mucosal lesions in dogs with acute intervertebral disc disease:
characterization and effects of omeprazole or misoprostol.
AB - We characterized gastric mucosal lesions in dogs with acute degenerative disc
disease treated by surgery and corticosteroid administration. The effect of
omeprazole and misoprostol on gastric lesions in these dogs was also evaluated.
Dogs were randomly assigned to 1 of 2 treatment groups or to the control group.
Treatment consisted of omeprazole at 0.7 mg/kg orally once daily, or misoprostol
at 2 microg/kg orally 3 times daily. All 3 groups received dexamethasone at 2
mg/kg on day 0, prednisolone at 2 mg/kg on day 1. prednisolone at 1 mg/kg on day
2, and prednisolone at 0.5 mg/kg on all further days (range, 5-6 days).
Endoscopic examination was performed on day 0 and 5-6 days later. Four regions of
the stomach were qualitatively scored from 1 to 12 based on the presence of
submucosal hemorrhage, erosion, or ulceration, with ulceration receiving the
highest numerical score. Nineteen of 25 dogs had gastric mucosal lesions at the
beginning of the study. No significant difference was found in the gastric lesion
score among the 3 groups at the end of the study. Gastric mucosal lesions were
concluded to be common in dogs with acute degenerative disc disease treated with
corticosteroids. Neither omeprazole nor misoprostol at the doses used was
effective in healing or preventing the further development of gastric mucosal
lesions.
PMID- 10668815
TI - Granulomatous disease associated with Bartonella infection in 2 dogs.
AB - Shortly after removal of an engorged tick from the left ear, a 4-year-old
Greyhound was referred for evaluation of fever and a rapidly enlarging mass in
the region of the left submandibular lymph node. Histopathologic evaluation of
the lymph node resulted in a diagnosis of severe granulomatous lymphadenitis. An
11-year-old mixed-breed dog was referred for evaluation of a 6-week history of
serous nasal discharge. Histologic examination of a surgical biopsy from a nasal
mass indicated multifocal granulomatous inflammation with fibrosis. Serum samples
obtained from both dogs were reactive by immunofluorescent assay to Bartonella
vinsonii subsp. berkhoffii antigens (reciprocal titers of 128). Although
Bartonella organisms were not isolated by lysis centrifugation blood culture,
Bartonella DNA was amplified from tissue samples obtained from each dog (lymph
node biopsy from dog 1 and nasal biopsy from dog 2) using primers that amplify a
portion of the 16S rRNA gene followed by Southern blot hybridization using a
genus-specific probe. Additionally, restriction fragment length polymorphism
(RFLP) analysis of a Bartonella-specific citrate synthase gene product obtained
from dog 2 resulted in a restriction pattern identical to B. vinsonii subsp.
berkhoffii. This is the 1st report of granulomatous disease in dogs associated
with Bartonella infection.
PMID- 10668816
TI - Functional urethral obstruction in 3 dogs: clinical and urethral pressure profile
findings.
AB - Three dogs with dysuria and urine retention caused by excessive functional
urethral resistance are described. All dogs had clinical histories and urologic
signs that previously would have been classified as detrusor-urethral
dyssynergia. Diagnosis of functional urinary obstruction was established by
exclusion of anatomic urinary obstruction and confirmed by urethral pressure
profilometry. In 2 cases, multiple pressure deflections recorded in the urethral
pressure profile suggested spasm of urethral musculature, whereas in a 3rd dog,
abnormally high pressures were recorded along a portion of the proximal urethra.
Functional urinary obstruction was associated with prostatitis in 1 dog and with
a history of urethral calculi in 1 dog, and no underlying disorder could be
identified in the remaining dog. All 3 dogs improved with medical treatments that
included alpha adrenergic antagonists. The etiology, diagnosis, and pharmacologic
management of functional urinary obstruction are discussed.
PMID- 10668817
TI - Seroprevalence of Ehrlichia canis, Ehrlichia equi, and Ehrlichia risticii in sick
dogs from North Carolina and Virginia.
AB - Ehrlichia canis, E. equi, and E. risticii seroprevalence was determined by
microimmunofluorescent antibody testing (IFA) in a sequential population of 1,845
sick dogs admitted during a 1-year period to the North Carolina State University
Veterinary Teaching Hospital. A seroreactor was defined by a reciprocal IFA titer
of > or =80 to E. canis, E. equi, or E. risticii antigens. Of the 48 IFA
seroreactors, 44 dogs were seroreactive to E. canis, 21 to E. equi, and 0 to E.
risticii. Seventeen dogs reacted to both E. canis and E. equi antigens. There was
concordance of E. canis IFA and western immunoblot (WI) test results for 36/44
dogs. Because of cross-reactivity of E. canis sera with E. equi antigens, WI was
of less utility to confirm E. equi exposure. After elimination of E. canis
seroreactors, there was concordance of 2/4 E. equi IFA and WI test results. Based
upon a retrospective review of medical records, ehrlichiosis was diagnosed in
10/48 (21%) IFA seroreactive dogs, 9 of which were confirmed positive by WI. Of
the remaining 38 IFA seroreactors, 29 also were confirmed by E. canis or E. equi
WI. These results indicate that (1) ehrlichiosis was not diagnosed in the
majority of serologically confirmed cases, (2) based upon E. canis and E. equi WI
analysis, IFA testing was not specific (21% false positive), (3) E. canis sera
cross-react with E. equi antigens, and (4) serologic evidence of E. risticii
infection was lacking in the dog population studied.
PMID- 10668818
TI - Prothrombin, activated partial thromboplastin, and proteins induced by vitamin K
absence or antagonists clotting times in 20 hyperthyroid cats before and after
methimazole treatment.
AB - The effect of daily doses of 5-15 mg of methimazole on the platelet count,
prothrombin time (PT), activated partial thromboplastin time (APTT), and proteins
induced by vitamin K absence or antagonists (PIVKA) clotting time in 20
hyperthyroid cats was determined. No significant (P > .05) difference was found
in median platelet count. PT, APTT, or PIVKA clotting time before treatment
compared to median values at 2-6 weeks or > or =7-12 weeks of methimazole
treatment. No cat had a prolonged APTT at any time. At 2-6 weeks of methimazole
treatment, 1 cat each developed thrombocytopenia or prolonged PIVKA clotting time
despite initially normal values. Three cats had abnormal coagulation tests
(prolonged PT [n = 1] and PIVKA clotting time [n = 3]) before treatment that
fluctuated during treatment. Excluding the 3 cats that had abnormal PIVKA
clotting time before treatment, prolonged PIVKA clotting time developed in 6%
(1/17; 95% confidence interval, 0-28%) cats treated with methimazole for 2-6
weeks. Seemingly. doses of methimazole commonly used to treat hyperthyroidism in
cats do not cause alteration in PT and APTT, and only rarely prolong PIVKA
clotting time. Nevertheless, abnormal PIVKA clotting time may explain bleeding
tendencies unassociated with thrombocytopenia in methimazole-treated hyperthyroid
cats.
PMID- 10668819
TI - Food hypersensitivity reactions in Soft Coated Wheaten Terriers with protein
losing enteropathy or protein-losing nephropathy or both: gastroscopic food
sensitivity testing, dietary provocation, and fecal immunoglobulin E.
AB - The purpose of this study was to evaluate Soft Coated Wheaten Terriers (SCWTs)
affected with protein-losing enteropathy (PLE) or protein-losing nephropathy
(PLN) or both for allergy to food. We performed gastroscopic food-sensitivity
testing, a provocative dietary trial, and measurement of fecal immunoglobulin E
(IgE) in 6 SCWTs affected with PLE or PLN or both. Positive gastroscopic food
sensitivity test reactions were noted in 5 of 6 dogs. Positive reactions were
found to milk in 4 dogs, to lamb in 2 dogs, and to wheat and chicken each in 1
dog. Adverse reactions to food (diarrhea, vomiting, or pruritus) were detected in
all 6 dogs during the provocative dietary trial. Adverse reactions were found to
corn in 5 dogs, to tofu in 3 dogs, to cottage cheese in 2 dogs, to milk in 2
dogs, to farina cream of wheat in 2 dogs, and to lamb in 2 dogs. Serum albumin
concentrations significantly decreased and fecal alpha1-protease inhibitor
concentration significantly increased 4 days after the provocative trial when
compared with baseline values. Antigen-specific fecal IgE varied throughout the
provocative trial, with peak levels following ingestion of test meals. We
conclude that food hypersensitivities are present in SCWTs affected with the
syndrome of PLE/PLN. Mild inflammatory bowel disease was already established in
the 6 SCWTs of this report at the time of study, making it impossible to
determine if food allergies were the cause or result of the enteric disease.
PMID- 10668820
TI - Familial protein-losing enteropathy and protein-losing nephropathy in Soft Coated
Wheaten Terriers: 222 cases (1983-1997).
AB - Records and pedigrees of Soft Coated Wheaten Terriers (SCWT) with protein-losing
enteropathy (PLE) or protein-losing nephropathy (PLN) were studied
retrospectively. Criteria for inclusion were defined based on analysis of blood
(panhypoproteinemia for PLE, hypoalbuminemia for PLN) and urine (proteinuria for
PLN) and histopathologic examination of tissue. Two hundred twenty-two affected
dogs (female:male ratio = 1.6, P < .001) were clinically identified. Dogs were
diagnosed with PLE earlier (P < .005; mean +/- SD age: 4.7+/-2.6 years, n = 76)
than with PLN (6.3+/-2.0 years, n = 84) or with both diseases (5.9+/-2.2 years, n
= 62). Clinical signs included vomiting, diarrhea, weight loss, pleural and
peritoneal effusions, and less commonly thromboembolic disease. Dogs with PLE
generally had panhypoproteinemia and hypocholesterolemia; intestinal lesions
included inflammatory bowel disease, dilated lymphatics, and lipogranulomatous
lymphangitis. Dogs with PLN generally had hypoalbuminemia, proteinuria,
hypercholesterolemia, and azotemia; renal lesions typically showed chronic
glomerulonephritis/glomerulosclerosis, and less commonly endstage renal disease.
Dogs with combined PLE/PLN had intermediate mean values (P < .001) for serum
total protein, albumin, globulin, and cholesterol but had a higher mean urine
protein:creatinine ratio than did PLN dogs (P < .05); intestinal and renal
lesions in these dogs were similar to those in the other groups. Two dogs had
incidental mild renal dysplasia. Pedigree analysis from 188 dogs demonstrated a
common male ancestor, although the mode of inheritance is unknown. Both PLE and
PLN are common diseases in this small breed population. The prognosis is poor.
Compared with previously reported intestinal and renal diseases in dogs, a new,
distinctive familial predisposition for both PLE and PLN has been recognized in
the SCWT breed.
PMID- 10668821
TI - Vincristine impairs platelet aggregation in dogs with lymphoma.
AB - Platelet aggregation before and after administration of 0.5 mg/m2 of vincristine
(VCR) was evaluated in 7 dogs with spontaneously occuring lymphoma. Aggregation
on platelet-rich plasma separated from blood collected in 3.8% sodium citrate was
performed using adenosine diphosphate (ADP), arachidonic acid (AA), and collagen
(COL) as agonists. The slope for aggregation in response to ADP was significantly
lower after administration of VCR (P = .032). Maximal aggregation after
administration of VCR was significantly lower in response to ADP, COL, and AA (P
= .03, P = .04, and P = .03, respectively).
PMID- 10668822
TI - Clinical evaluation of methoximorpholino-doxorubicin (FCE 23762) in dogs with
spontaneous malignancies.
AB - We conducted a clinical evaluation of FCE 23762, a methoxymorpholino analog of
doxorubicin, in 48 dogs with metastatic, nonresectable, or chemotherapy-resistant
spontaneous malignancies at an initial dosage of 50-60 microg/kg IV every 3
weeks. Clinical evidence of toxicity was minimal; 6 dogs developed grades I, II,
and III hematologic toxicities after the 1st treatment, and 1 dog developed grade
II gastrointestinal toxicity. One dog became pancytopenic 4 months after
discontinuation of FCE 23762. No other adverse effects were noted. Partial or
complete remissions were observed in 32% of the dogs. Responses were observed
both in previously untreated dogs and in those that had received prior
chemotherapy, including doxorubicin. FCE 23762 is a promising new antineoplastic
agent that can be used safely in dogs with cancer; doses higher than those used
in this study may be used eventually in practice.
PMID- 10668823
TI - Hemodynamic and electrocardiographic effects of graded doses of amiodarone in
healthy dogs anesthetized with morphine/alpha chloralose.
AB - This research was designed to study acute hemodynamic and electrocardiographic
effects of amiodarone and to determine an IV dose of amiodarone that minimally
affects left ventricular function and does not increase the tendency for
ventricular arrhythmia.
PMID- 10668825
TI - Necrosis of hippocampus and piriform lobe in 38 domestic cats with seizures: a
retrospective study on clinical and pathologic findings.
AB - The clinical records of 38 cats (1985-1995) with a neuropathologically confirmed
diagnosis of necrosis of the hippocampus and occasionally the lobus piriformis
were evaluated retrospectively. There was no sex or breed predisposition. Most
cats were between 1 and 6 years of age (mean age 35 months) and had either
generalized or complex-partial seizures of acute onset and rapid progression. The
seizures had a tendency to become recurrent and to present as clusters or even
status epilepticus later in the course of the disease. Fourteen cats died
spontaneously, and 24 were euthanized. Histopathologic examination revealed
bilateral lesions restricted to the hippocampus and occasionally the lobus
piriformis. The lesions seemed to reflect different stages of the disease and
consisted of acute neuronal degeneration to complete malacia, affecting mainly
the layer of the large pyramidal cells but sometimes also the neurons of the
dentate gyrus and the piriform lobe. The clinical, neuropathologic, and
epidemiologic findings suggest that the seizures in these cats were triggered by
primary structural brain damage, perhaps resulting from excitotoxicity. The cause
remains unknown, but epidemiologic analysis suggests an environmental factor,
probably a toxin.
PMID- 10668824
TI - Hepatopathy in 4 dogs treated with amiodarone.
AB - Amiodarone is a class III antiarrhythmic drug used in dogs with dilated
cardiomyopathy and ventricular tachyarrhythmias. Hepatopathy is one of the more
commonly reported adverse effects of amiodarone use in people. We describe 4 dogs
that developed hepatopathy associated with amiodarone administration; 2 dogs also
developed neutropenia. Three dogs had clinical signs of anorexia and lethargy; 1
did not show signs until impaired liver function had developed. Clinical signs or
biochemical abnormalities developed 1.5-8 months after amiodarone treatment was
started. Clinical signs resolved within 2 weeks of discontinuing amiodarone, but
biochemical abnormalities did not resolve for 6-8 weeks. The delay between onset
of liver disease and overt clinical signs suggests that serial evaluation of
liver enzyme activities following amiodarone use in does is important.
PMID- 10668826
TI - Disseminated hemangiosarcoma in the horse: 35 cases.
AB - Thirty-five cases of disseminated hemangiosarcoma (21 clinical cases and 14
previously reported cases) were reviewed to describe the disease in horses.
Hemangiosarcoma occurred in mature, particularly middle-aged horses, with no
apparent sex predilection. Thoroughbreds seemed to be overrepresented (13 cases)
but a true breed predilection could not be established. The respiratory and
musculoskeletal systems were most commonly affected and presenting complaints
included dyspnea (26%), subcutaneous or muscular swelling (24%), epistaxis (17%),
and lameness (12%). Heart and respiratory rates were usually increased and mucous
membrane color was frequently pale or icteric. Capillary refill time and rectal
temperature were often normal. Anemia (88%), neutrophilic leukocytosis (62%), and
thrombocytopenia (48%) were common. Examination of tissue samples collected by
fine-needle aspirate or biopsy established an antemortem diagnosis in 4 horses.
The diagnosis was made during postmortem examination in the remaining 31 horses.
The lung and pleura (77%), skeletal muscle (46%), and spleen (43%) were most
commonly affected. A primary site of tumor involvement could be identified in 22
horses. Hemangiosarcoma should be included as a differential diagnosis for horses
with evidence of hemorrhage into body cavities, skeletal muscle, or subcutaneous
locations.
PMID- 10668827
TI - Acute B-cell lymphoblastic leukemia with meningeal metastasis causing primary
neurologic dysfunction in a dog.
PMID- 10668828
TI - The market pushes education from ward to office, from acute to chronic illness
and prevention: will case method teaching-learning change?
PMID- 10668829
TI - Hypertension in the elderly: can we improve results of therapy?
AB - Awareness of and therapy for hypertension in the United States have been
increasing in older patients. Despite this improvement, hypertension continues to
be poorly controlled in this patient population. The control rate, defined as
systolic blood pressure less than 140 mm Hg and diastolic blood pressure less
than 90 mm Hg, is surprisingly low for older patients, despite abundant data
documenting the reduction of cardiovascular events by treating both systolic
diastolic and isolated systolic hypertension. Comorbid diseases and physiological
alterations in the elderly, including reduced myocardial contractility, renal
function, total body water, baroreceptor responsiveness, and cognitive function,
must be considered, but in general these have not limited the effectiveness of
antihypertensive drug therapy.
PMID- 10668830
TI - The role of spiral volumetric computed tomography in the diagnosis of pulmonary
embolism.
AB - To evaluate the evidence for the use of spiral volumetric computed tomography
(SVCT) in the diagnosis of acute pulmonary embolism (PE), the 11 English-language
studies published through July 1998 that compared SVCT with a reference standard
for PE were systematically reviewed. Among the reviewed studies, methodological
problems were common. Only 5 of these studies fulfilled 5 of 11 basic standards
addressing important issues in diagnostic test research. The reported
sensitivities of SVCT compared with pulmonary angiography varied widely (64%
93%), which was likely the result of differences in study populations. Spiral
volumetric computed tomography may be relatively sensitive and specific for
diagnosing central pulmonary artery PEs, but it is insensitive for diagnosing
subsegmental clots. Spiral volumetric computed tomography may have a role as a
"rule-in" test for large central emboli, but additional research is required to
establish its place in clinical practice.
PMID- 10668831
TI - Improving preventive care by prompting physicians.
AB - OBJECTIVES: To assess the impact of prompting physicians on health maintenance,
answer questions regarding the mode of delivery, and identify opportunities and
limitations of this information intervention. METHODS: Systematic electronic and
manual searches (January 1, 1966, to December 31, 1996) were conducted to
identify clinical trial reports on prompting clinicians. Three eligibility
criteria were applied: (1) randomized controlled clinical trial, (2) clinician
prompt, alert, or reminder in the study group and no similar intervention in the
control group, and (3) measurement of the intervention effect on the frequency of
preventive care procedures. Data were abstracted by independent reviewers using a
standardized abstraction form, and quality of methodology was scored. A series of
meta-analyses on triggering clinical actions was performed using the random
effects method. The statistical analyses included 33 eligible studies, which
involved 1547 clinicians and 54 693 patients. RESULTS: Overall, prompting can
significantly increase preventive care performance by 13.1% (95% confidence
interval [CI], 10.5%-15.6%). However, the effect ranges from 5.8% (95% CI, 1.5%
10.1%) for Papanicolaou smear to 18.3% (95% CI, 11.6%-25.1%) for influenza
vaccination. The effect is not cumulative, and the length of intervention period
did not show correlation with effect size (R = -0.015, P = .47). Academic
affiliation, ratio of residents, and technique of delivery did not have a
significant impact on the clinical effect of prompting. CONCLUSIONS: Dependable
performance improvement in preventive care can be accomplished through prompting
physicians. Vigorous application of this simple and effective information
intervention could save thousands of lives annually. Health care organizations
could effectively use prompts, alerts, or reminders to provide information to
clinicians when patient care decisions are made.
PMID- 10668832
TI - Predictive value of compression ultrasonography for deep vein thrombosis in
symptomatic outpatients: clinical implications of the site of vein
noncompressibility.
AB - BACKGROUND: Compression ultrasonography has a high negative predictive value for
deep vein thrombosis in symptomatic outpatients. Limited data are available on
factors influencing positive predictive value. The objective of this study was to
evaluate the positive predictive value of compression ultrasonography according
to the anatomic site of vein noncompressibility. METHODS: We performed a
prospective cohort study of 756 consecutive outpatients with suspected first
episode deep vein thrombosis. Compression ultrasonography was performed at the
initial visit: results were abnormal if a noncompressible segment was identified
or normal if all segments were fully compressible. Venography was performed in
patients with abnormal compression ultrasonography results. Positive predictive
value was determined according to the site of noncompressibility: common femoral
vein only, popliteal vein only, or both sites. Venography was the reference
standard for the presence of deep vein thrombosis. RESULTS: Positive predictive
value was 16.7% (95% confidence interval, 0.4%-64.1%) for noncompressibility
isolated to the common femoral vein compared with 91.3% (95% confidence interval,
72.0%-98.9%) for the popliteal vein only and 94.4% (95% confidence interval,
72.7%-99.9%) for both sites (P<.001). Of 15 patients with isolated
noncompressibility of the common femoral vein, 8 (53%) had pelvic neoplasm or
abscess compared with 2 (5%) of 42 with noncompressibility of the popliteal vein
only and 6 (13%) of 47 with noncompressibility of both sites (P<.001).
CONCLUSIONS: The positive predictive value of noncompressibility isolated to the
common femoral vein is too low to be used alone as the diagnostic end point for
giving anticoagulant therapy. Noncompressibility isolated to the common femoral
vein is a diagnostic marker for pelvic disease.
PMID- 10668833
TI - Prevalence and content analysis of guidelines on handling requests for euthanasia
or assisted suicide in Dutch nursing homes.
AB - BACKGROUND: The growing number of requests for euthanasia or assisted suicide
(EAS) makes it imperative for health care institutions, such as nursing homes, to
have written guidelines on how to handle requests for EAS. The objective of this
study was to determine the prevalence of EAS guidelines in Dutch nursing homes
and to analyze the content. METHODS: Directors of patient care in 324 Dutch
nursing homes were asked, by means of a mailed short list of questions, if they
had an institutional guideline on EAS and, if so, to provide a copy. Guidelines
were analyzed according to a structured list of items based on current
jurisprudence, model documents, and opinions of experts. RESULTS: Of the 324
directors, 313 (97%) responded. In 58% of the nursing homes that responded, there
existed written guidelines for EAS. Of those guidelines, 74% concerned EAS; in
26%, EAS was integrated in a guideline on terminal care. Of the guidelines, 165
(90%) were based on the policy that EAS is acceptable under specific conditions,
and 18 (10%) banned EAS completely. Of the first-mentioned guidelines, 81%
described one or more procedures for in-principle objections. In 65% of these
guidelines, all official requirements for prudent practice were described.
CONCLUSIONS: Despite the rapidly growing number of nursing-home guidelines on EAS
and the existence of model documents, there is still considerable variation in
the guidelines, and they can be improved in many aspects. A basic prerequisite is
that the guidelines include all the official requirements for prudent practice.
PMID- 10668834
TI - Ten-year trends in hospital care for congestive heart failure: improved outcomes
and increased use of resources.
AB - BACKGROUND: Scarce data are available on long-term trends in hospital mortality,
length of stay (LOS), and costs in congestive heart failure (CHF). OBJECTIVE: To
assess 10-year trends in the outcomes of patients hospitalized with CHF. METHODS:
We studied all 6676 patients with a primary discharge diagnosis of CHF
hospitalized from January 1, 1986, through July 31, 1996, at an academic tertiary
care center. Hospital mortality, LOS, and costs were adjusted for
sociodemographic characteristics, comorbidities, invasive procedures, hospital
disposition, and LOS where appropriate. RESULTS: The mean (+/- SD) age of
patients was 70+/-13 years; 54.1% were male; 87.0% were white. There was a
significant increasing trend in heart failure severity as assessed by a CHF
specific risk-adjustment index. The proportion of patients who underwent invasive
procedures (e.g., cardiac catheterization, coronary angioplasty, coronary artery
bypass surgery, defibrillator and pacemaker implantation) was significantly
higher in the 1994-1996 period. The standardized mortality ratio (observed
mortality/predicted mortality) progressively fell during the study period.
Compared with patients admitted before 1991, those admitted after 1991 had a 24%
lower observed than predicted mortality. Adjusted LOS exhibited a downward trend,
ie, 7.7 days in 1986-1987 to 5.6 days in 1994-1996 (P<.001). Unadjusted cost
peaked during 1992-1993 and declined thereafter. Adjusted costs in 1994-1996 were
not significantly different from those in 1990-1991. CONCLUSIONS: After risk
adjustment for sociodemographic characteristics, comorbidities, and disease
severity, a significant decrease in in-hospital mortality was observed during the
study decade. This decline in hospital mortality occurred in parallel with
decreasing LOS and increasing use of cardiac procedures and costs.
PMID- 10668835
TI - Prevention of venous thromboembolism: adherence to the 1995 American College of
Chest Physicians consensus guidelines for surgical patients.
AB - BACKGROUND: The American College of Chest Physicians addressed the dilemma of
identifying optimal therapy for venous thromboembolism (VTE) prophylaxis and
published their Fourth Consensus Conference on Antithrombotic Therapy in 1995,
with recommendations for prophylactic therapy. Despite these recommendations,
appropriate VTE prophylactic therapy is underused. OBJECTIVES: To examine routine
practices in the prevention of VTE in high-risk surgical patients and to
determine the extent of adoption of grade A prophylactic therapies as recommended
by the American College of Chest Physicians. METHODS: Retrospective medical
record review in 10 teaching or community-based hospitals located in the United
States. Medical charts of 1907 patients were randomly selected for review from
the population of patients who underwent high-risk major abdominal surgery, total
hip replacement, hip fracture repair, or total knee replacement between January
1, 1996, and February 28, 1997. RESULTS: Of 1907 patients, VTE prophylaxis was
used in 89.3%; use was 93.7% in each of the 3 orthopedic surgery groups and 75.2%
in the high-risk major abdominal surgery group. The percentage of patients
receiving grade A therapy was highest in the hip replacement group (84.3%) vs.
the other groups (knee replacement, 75.9%; hip fracture repair, 45.2%; abdominal
surgery, 50.3%). CONCLUSIONS: The use of grade A prophylaxis was related to the
type of surgery, with the highest use seen in total hip replacement and the
lowest in hip fracture repair. One in 4 patients who underwent high-risk major
abdominal surgeries failed to receive any form of VTE prophylaxis. Publication of
consensus statements alone may be insufficient to ensure the incorporation of
important new clinical information into routine practice.
PMID- 10668836
TI - Sex bias and underutilization of lipid-lowering therapy in patients with coronary
artery disease at academic medical centers in the United States and Canada.
Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial
(PREVENT) Investigators.
AB - BACKGROUND: The efficacy of lipid-lowering therapy (LLT) has been well
established for patients with preexisting coronary artery disease (CAD). However,
limited information is available assessing the extent to which these medications
are prescribed in academic medical centers. METHODS: The use of LLT for patients
with CAD was prospectively evaluated in 825 men and women who were recruited from
16 academic medical centers in the United States and Canada to participate in the
Prospective Evaluation of the Vascular Events of Norvasc Trial (PREVENT). The
assessment of LLT use during the 3-year trial was evaluated in patients receiving
amlodipine therapy and placebo; levels of low-density lipoprotein cholesterol
(LDL-C) were used to assess the impact of LLT. RESULTS: Despite a baseline
prevalence of LLT in 42% of men (38% in 1994), half of the patients had high
levels of LDL-C (>3.36 mmol [>130 mg/dL]). During the subsequent 3 years, the
prevalence of elevated LDL-C levels dropped in men (29%) but remained stagnant in
women (48%). These changes were associated with increased LLT in men (55%) but
not in women (35%) (P = .04). In 1994, the LDL-C target goal (<2.59 mmol/L [<100
mg/dL]) was attained in 17% of men and 6% of women (P = .006). At study
completion in 1997, the LDL-C target goal was achieved in 31% of men and only 12%
of women (P = .001). CONCLUSIONS: This study highlights the relatively low
treatment rates of hyperlipidemia among patients with CAD overall and women in
particular who were participating in a clinical trial at academic medical centers
in the United States and Canada. Because LLT has been proven to reduce future
cardiovascular events, these results suggest that more intensive efforts should
be promoted in order to maximize CAD reduction.
PMID- 10668837
TI - Angiotensin-converting enzyme inhibitors, calcium channel blockers, and breast
cancer.
AB - BACKGROUND: The use of angiotensin-converting enzyme (ACE) inhibitors has been
linked to a decreased risk of developing cancer, and longer-term use of calcium
channel blockers (CCBs) has been associated with an increased risk of developing
cancer in general and breast cancer in particular. METHODS: Using data from the
General Practice Research Database, we conducted a large case-control analysis.
Previous exposure to ACE inhibitors, CCBs, and beta-blockers was compared between
3706 postmenopausal women who were diagnosed with incident breast cancer between
1992 and 1997 and 14155 matched-control women. RESULTS: Compared with nonusers of
antihypertensive drugs, women who used ACE inhibitors (odds ratio [OR], 1.0; 95%
confidence interval [CI], 0.7-1.5), CCBs (OR, 0.9; 95% CI, 0.7-1.2), or beta
blockers (OR, 1.0; 95% CI, 0.8-1.2) for 5 or more years were not at an increased
or decreased risk of developing breast cancer (adjusted for smoking and body mass
index [calculated as weight in kilograms divided by the square of height in
meters]). The risk of breast cancer did not differ between users of different ACE
inhibitors or different CCBs (dihydropyridines, diltiazem hydrochloride, and
verapamil hydrochloride) or between users of short-acting (OR, 1.0; 95% CI, 0.7
1.4) or sustained-release (OR, 1.0; 95% CI, 0.8-1.3) nifedipine preparations.
CONCLUSION: The findings of this large case-control analysis do not support the
hypothesis that longer-term use of ACE inhibitors or CCBs affects the risk of
developing breast cancer.
PMID- 10668838
TI - A nationwide study of decisions to forego life-prolonging treatment in Dutch
medical practice.
AB - BACKGROUND: Decisions to withhold or withdraw life-prolonging treatment in
terminally ill patients are common in some areas of medical practice. Information
about the frequency and background of these decisions is generally limited to
specific clinical settings. This article describes the practice of withholding or
withdrawing life-prolonging treatment in the Netherlands. METHODS: Questionnaires
were sent to the attending physicians of a stratified sample of 6060 of all 43002
cases of death in the Netherlands from August 1 through November 30, 1995. The
questions concerned the treatments foregone, the patient characteristics, and the
decision-making process. The response rate was 77%. RESULTS: A nontreatment
decision was made in 30% (95% confidence interval, 28%-31%) of all deaths in the
Netherlands in 1995; this is an increase compared with 28% (95% confidence
interval, 26%-29%) in 1990; in 20% of all deaths, this decision was the most
important end-of-life decision. Artificial nutrition or hydration and antibiotics
were the treatments most frequently foregone, each accounting for 25% of cases in
which a nontreatment decision was made. Nursing-home physicians withheld or
withdrew treatment more often than clinical specialists or general practitioners
in 52%, 35%, and 17% of all deaths they were involved with, respectively. Of the
patients in whom a nontreatment decision was the most important end-of-life
decision, 26% were competent; of those, 93% were involved in the decision making.
In 17% of patients, the nontreatment decision was made without being discussed
with the patient or the patient's relatives and without knowledge of the
patient's wishes. Life was shortened by an estimated 24 hours or less in 42% and
1 month or more in 8% of patients. CONCLUSIONS: Decisions to forego life
prolonging treatment are frequently made end-of-life decisions in the Netherlands
and may be increasing. Most of these decisions do not involve high-technology
treatments, and the consequences, in terms of shortening of life, are relatively
small.
PMID- 10668839
TI - Marked declines in human immunodeficiency virus-related mortality in Chicago in
women, African Americans, Hispanics, young adults, and injection drug users, from
1995 through 1997.
AB - BACKGROUND: Declines in human immunodeficiency virus (HIV)-related mortality
between 1995 and 1996 were seen across the United States but were small to
nonexistent among people in marginalized sectors who are most likely to contract
HIV and die of its effects. No comprehensive analysis describing HIV-related
mortality in 1997 was available. OBJECTIVE: To describe Chicago's HIV-related
mortality trends up to and including 1997, with specific attention focused on
marginalized populations. METHODS: An analysis of cross-sectional HIV-related
mortality data with emphasis on the years 1995 through 1997 was conducted for
Chicago, Ill. Numbers, proportions, and rates of declines in HIV-related deaths
were examined for the city as a whole and also among those diagnosed at Cook
County Hospital, as a proxy for people with very low socioeconomic status.
RESULTS: Between 1995 and 1996 there was an overall decline of 19% in HIV-related
mortality in Chicago but small or no declines among women, African Americans,
Hispanics, injection drug users, and people aged 20 to 29 years and more than 50
years. Between 1995 and 1997 there was an overall decline of 61%. At that time
the declines were spread more evenly across diverse groups. There were almost no
significant differences between the declines for these groups at Cook County
Hospital and in the rest of Chicago. CONCLUSIONS: The HIV-related mortality has
fallen dramatically in Chicago since 1995, the year of its maximum. During 1997,
declines were seen among all groups. Declines were also seen among the most
disenfranchised of the city. Access to care and the new combination therapies are
apparently sustaining life for many in Chicago.
PMID- 10668840
TI - Autopsy consent practice at US teaching hospitals: results of a national survey.
AB - BACKGROUND: Autopsy rates continue to fall despite the enduring benefit of the
procedure to families and medical science, yet there are few data about the
consent process itself. OBJECTIVE: To evaluate the current practice of obtaining
autopsy consent, by assessing the consent forms currently in use, the knowledge
and attitudes of chief residents on the procedure, and the expert opinion of
pathologists in those institutions. DESIGN: Cross-sectional survey. SETTINGS AND
PARTICIPANTS: One hundred twenty-seven US teaching hospitals. RESULTS: Of all
autopsy consent forms we surveyed, 84.7% contained 7 of 10 elements recommended
by the College of American Pathologists. Only 7.1% of institutions supplied
educational materials for the physician, as recommended by the College of
American Pathologists. Overall, 50.1% of chief residents reported deficiencies in
their knowledge of the autopsy procedure. Correspondingly, greater than 74.5%
felt that educational materials would be beneficial for physicians and the
family. Finally, 93.3% of chief residents believed that a limited autopsy should
be offered to families, while 68 (90%) of 76 pathologists at these institutions
believed that limited autopsies are an unsatisfactory alternative to the complete
procedure. CONCLUSIONS: Chief residents at US teaching hospitals reported
substantial deficiencies in their knowledge about autopsy and desire more
training on the consent process. Autopsy consent forms are often lacking
information that might help physicians and families in making an educated choice
about autopsy. Teaching institutions need to reevaluate the training for the
autopsy consent practice.
PMID- 10668841
TI - Hypercoagulable states in primary upper-extremity deep vein thrombosis.
AB - BACKGROUND: There are very few data on the prevalence of coagulation
abnormalities in primary deep vein thrombosis of the upper limbs. OBJECTIVE: To
determine if coagulation abnormalities play a role in effort-related and/or
idiopathic (non-effort-related) upper-extremity deep vein thrombosis (UEDVT).
METHODS: Fifty-one consecutive patients (21 men and 30 women) who had effort
related (n = 20) or idiopathic (n = 31) UEDVT over an 18-year period (median age
at diagnosis, 32 years; age range, 15-86 years) were routinely reexamined. Plasma
was screened for antithrombin, protein C, and protein S deficiencies and for
antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies).
The DNA was screened for factor V Leiden and for prothrombin gene G20210A
mutations. RESULTS: The median age (35 vs. 28 years), the proportion of women
(81% [25/31] vs. 25% [5/201), the proportion of patients with a personal and/or
family history of thromboembolism (42% [13/31] vs. 15% [3/20]), and the
proportion of patients with at least 1 coagulation abnormality (42% [13/31] vs.
15% [3/20]) were higher in the idiopathic UEDVT group than in the effort-related
UEDVT group. The odds ratio of having a coagulation abnormality was 4.09 (95%
confidence interval, 0.99-16.78; P = .06) in the idiopathic UEDVT group compared
with the effort-related UEDVT group. CONCLUSION: Hypercoagulable states appear to
play a significant role in idiopathic but not in effort-related UEDVT.
PMID- 10668842
TI - Fulminant non--A-G viral hepatitis leading to liver transplantation.
AB - BACKGROUND: All hepatotropic viruses are known to cause fulminant hepatic failure
(FHF). However, in 30% to 40% of patients with FHF, the precise cause remains
unknown. We aimed to better define this subgroup. METHODS: We evaluated the
clinical course and outcome of 7 patients admitted during a 22-month period with
fulminant viral hepatitis leading to liver transplantation; none had serologic or
molecular evidence of hepatitis A, B, C, D, E, or G viral infection, thus the
term non-A-G viral hepatitis. All known etiologies of FHF were excluded. RESULTS:
All patients had prodromal symptoms suggestive of viral causes. Mean age was 30
years. The interval between onset of jaundice and appearance of encephalopathy
was 23 days (range, 4-50 days). Five patients had grade III/IV encephalopathy.
Serum alanine aminotransferase levels showed a single peak of activity. The
duration between first symptoms and liver transplantation was 28 days (range, 12
71 days). Results of histological study of the explanted liver showed submassive
(4 patients) or massive (3 patients) hepatocyte necrosis. In all patients,
results of polymerase chain reaction analysis did not detect hepatitis B virus
DNA, hepatitis C virus RNA, or hepatitis G virus RNA in the explanted liver.
After transplantation, 2 patients showed (6 months later) increased liver enzyme
levels of undetermined cause, and results of a liver biopsy showed mild lobular
hepatitis; 1 patient had lymphoproliferative disorder (Epstein-Barr virus
originated); and 1 patient, aplastic anemia, which is known to be associated with
seronegative viral hepatitis. The latter patient died, whereas the other 6
patients are alive (survival rate, 86%). CONCLUSIONS: Our patients with non-A-G
viral hepatitis had a severe acute onset with progressive FHF requiring liver
transplantation. There is some suggestion of recurrent viral disease after
transplantation implicating other unknown viruses in the etiology.
PMID- 10668843
TI - Successful treatment with combination therapy of cyclophosphamide and cyclosporin
for late recurrence of Wegener granulomatosis.
PMID- 10668844
TI - Aspirin in the treatment of type 2 diabetes.
PMID- 10668845
TI - Virologic response associated with a change in protease inhibitor therapy.
PMID- 10668846
TI - The lipid-lowering effect of lean meat diets falls far short of that of
vegetarian diets.
PMID- 10668847
TI - Increased bioavailability of oral melatonin after fluvoxamine coadministration.
AB - BACKGROUND: Fluvoxamine, a selective serotonin reuptake inhibitor, is known to
elevate melatonin serum concentrations. It has not been clear whether these
effects might be attributed to an increased melatonin production or to an
decreased elimination of melatonin. The latter hypothesis was tested by this
study. METHODS: Five healthy male volunteers (one CYP2D6 poor metabolizer)
received 5 mg melatonin either with or without coadministration of 50 mg
fluvoxamine. Serum concentrations of melatonin and fluvoxamine were assessed from
0 to 28 hours after melatonin intake. RESULTS: Coadministration of fluvoxamine,
on average, led to an 17-fold higher (P < .05) area under concentration-time
curve (AUC) and a 12-fold higher (P < .01) serum peak concentration (Cmax) of
melatonin. The terminal elimination half-life was not significantly affected. The
AUC and Cmax of fluvoxamine were about three times higher and the half-life was
about two times higher in the poor metabolizer. There was a correlation (r =
0.63; P < .01) between the melatonin and fluvoxamine serum concentrations. The
poor metabolizer was found to have a more pronounced and longer-lasting effect of
fluvoxamine on the pharmacokinetics of melatonin. CONCLUSION: This study showed
an increase in the bioavailability of oral melatonin by coadministration of
fluvoxamine. The effects of fluvoxamine on the melatonin serum concentrations in
patients with depression might therefore be caused by inhibition of the
elimination of melatonin and not attributable to an increased production of
melatonin.
PMID- 10668849
TI - Gentamicin effects on urinary electrolyte excretion in healthy subjects.
AB - BACKGROUND: Symptomatic hypomagnesemia, hypocalcemia, and hypokalemia caused by
renal electrolyte wasting occasionally develop in patients treated with
aminoglycosides. This phenomenon has been attributed to aminoglycoside tubular
injury. However, rats administered a single dose of gentamicin show immediate
dose-related calcium and magnesium renal wasting without sodium or potassium
wasting days before other evidence of tubular dysfunction or structural injury
can be shown. The mechanism is undefined but transient and is not dependent on
the presence of parathyroid hormone. OBJECTIVE: To determine whether gentamicin
administration to humans causes renal electrolyte wasting. DESIGN: Five healthy
volunteers ingested a 400-mg calcium, 100-mEq sodium diet for 1 week before the
study. After a 90-minute baseline period, 5 mg/kg gentamicin was administered
intravenously over 30 minutes. Urine and serum were collected for 5 hours after
gentamicin administration. RESULTS: Peak serum gentamicin levels ranged from 12.8
to 20.6 microg/mL. There was no change in serum electrolytes. The urinary
fractional calcium excretion rose from a baseline of 1.8% +/- 0.5% to 6.8% +/-
1.4% (P < .01), and the magnesium fractional excretion rose from 3.4% +/- 0.8% to
11.8% +/- 6.4% (P = .03). These effects were transient. Gentamicin caused no
change in renal excretion of sodium, potassium, or phosphate. CONCLUSIONS:
Gentamicin administered at the standard clinical dose causes immediate and
transient renal calcium and magnesium wasting in normal humans. The mechanism of
gentamicin-associated urinary magnesium wasting and calciuria is undefined.
However, the pattern of electrolyte excretion after gentamicin administration
suggests that the site of action of these gentamicin effects is the distal
convoluted tubule.
PMID- 10668848
TI - Pharmacokinetics of repaglinide in subjects with renal impairment.
AB - OBJECTIVE: To evaluate the effect of renal impairment and renal failure on the
pharmacokinetics and safety of repaglinide. METHODS: We conducted a phase I,
multicenter, parallel-group, pharmacokinetic comparison trial with single and
multiple doses of repaglinide in subjects with various degrees of renal
impairment. Subjects with normal renal function (n = 6) and subjects with renal
impairment (mild to moderate, n = 6; severe, n = 6) received treatment with 2 mg
repaglinide for 7 days. Subjects in the hemodialysis group (n = 6) received two
single doses of 2 mg repaglinide separated by a 7- to 14-day washout period. All
subjects had repaglinide serum pharmacokinetic profiles measured for the first
and last doses administered. Serum steady-state levels, urine levels, and
dialysate levels were also measured. RESULTS: Pharmacokinetic parameters did not
show significant changes after single or multiple doses of repaglinide, although
the elimination rate constant in the group with severe renal impairment decreased
after 1 week of treatment. Subjects with severe impairment had significantly
higher area under the curve values after single and multiple doses of repaglinide
than subjects with normal renal function. No significant differences in values
for maximum serum concentration or time to reach maximum concentration were
detected between subjects with renal impairment and those with normal renal
function. Hemodialysis did not significantly affect repaglinide clearance.
CONCLUSIONS: Repaglinide was safe and well tolerated in subjects with varying
degrees of renal impairment. Although adjustment of starting doses of repaglinide
is not necessary for renal impairment or renal failure, severe impairment may
require more care when upward adjustments of dosage are made.
PMID- 10668850
TI - Local venous response to N-desethylamiodarone in humans.
AB - OBJECTIVE: Amiodarone, a class III antiarrhythmic agent, is a potent vasodilator
in vivo. Its main metabolite, N-desethylamiodarone, contributes to the
antiarrhythmic action of amiodarone after long-term treatment. It is unknown
whether N-desethylamiodarone has acute vascular effects. The aim of this study
was to explore the mechanism of action of N-desethylamiodarone in human hand
veins. METHODS: The dorsal hand vein compliance technique was applied in 36
healthy male volunteers. In hand veins preconstricted with the alpha1-adrenergic
receptor agonist phenylephrine or prostaglandin F2alpha, N-desethylamiodarone and
an inhibitor of nitric oxide formation (N(G)-monomethyl-L-arginine, L-NMMA) were
infused in the presence or absence of a cyclooxygenase inhibitor (acetylsalicylic
acid), and the venodilator effect was measured. Furthermore, N-desethylamiodarone
was infused after oral treatment with hydrocortisone or coinfused with alpha
tocopherol. Additional experiments were carried out in bovine aortic endothelial
cells to explore the effects of N-desethylamiodarone on the intracellular Ca2+
concentration ([Ca2+]i). RESULTS: N-Desethylamiodarone produced dose-dependent
venodilation (47% +/- 4% maximum). In vitro, 10 micromol/L N-desethylamiodarone
caused a sustained increase of the endothelial [Ca2+]i. Pretreatment of the
volunteers with acetylsalicylic acid reduced the maximum N-desethylamiodarone
induced venodilation to 22% +/- 8%; L-NMMA reduced the maximum N
desethylamiodarone-induced venodilation to 18% +/- 11%. Pretreatment with
acetylsalicylic acid and coinfusion of N-desethylamiodarone and L-NMMA abolished
the venodilation, whereas hydrocortisone had no effect. Coinfusion of alpha
tocopherol and N-desethylamiodarone reduced the maximum N-desethylamiodarone
induced venodilation to 11% +/- 4%. CONCLUSIONS: In concentrations estimated to
be in the therapeutic range, N-desethylamiodarone dilates preconstricted human
hand veins in vivo and increases endothelial [Ca2+]i in vitro. Subsequently the
cyclooxygenase (COX-1) and the endothelial nitric oxide synthase pathways are
activated. The resulting venodilation does not involve inflammatory cytokines,
inducible nitric oxide synthase, or inducible cyclooxygenase (COX-2).
PMID- 10668852
TI - Overconsumption detected by electronic drug monitoring requires subtle
interpretation.
AB - BACKGROUND: Electronic compliance monitoring has provided new variables to
describe drug intake behavior and new strategies to improve compliance. However,
as evaluated in this study, the recording of opening events of pill bottles does
not necessarily mean drug intake. METHODS: In an open 3-week trial with an oral
vitamin combination, drug intake was recorded with use of an electronic pill box
that contained 25 capsules and that registered each opening of the bottle. Thirty
seven patients were asked to take one capsule every morning for 21 days. Opening
and closing events were related to the results of pill counts and patient
interviews at the end of the trial. RESULTS: Drug consumption was 101.8% (663
recorded opening and closing events) in the 31 patients who completed the trial.
Pill boxes were opened more than once by 10 patients on at least one monitored
day. For seven patients the total number of openings was >25 (range, 26 to 29)
and thus exceeded the number of capsules provided. A third interview of these
patients revealed real overconsumption in only two patients. Six patients
remembered that they had shown the device to relatives or friends or that they
had checked to see whether they had closed the pill box well, thus turning a
"curiosity event" into a drug intake event. CONCLUSION: In short-term studies
particularly, such curiosity events may substantially modify the electronic
assessment of compliance surrogates. In these trials the combined evaluation of
electronic openings, pill counts, and interviews may be a suitable way to reveal
such openings without pill intake.
PMID- 10668851
TI - In vivo effects of interleukin-10 on human cytochrome P450 activity.
AB - BACKGROUND: Injection of lipopolysaccharide into human volunteers leads to an
increase in serum interleukin-1beta, interleukin-6, and tumor necrosis factor
alpha and a significant decrease in cytochrome P450 (CYP)-mediated drug
metabolism. The in vivo effects of the noninflammatory cytokine interleukin-10
(IL-10) on CYP-mediated drug metabolism was examined. METHODS: IL-10 (8
microg/kg) and placebo were administered for 6 days to 12 healthy volunteers in a
double-blind crossover study. Tolbutamide (CYP2C9), caffeine (CYP1A2),
dextromethorphan (CYP2D6 and CYP3A), and midazolam (CYP3A) were administered on
days 4 and 5 to determine individual CYP activities. RESULTS: Few clinically
apparent side effects were observed after administration of IL-10; however, blood
chemistries reflected an acute-phase response. A significant drop in serum
albumin (mean percentage change +/- SD between groups; 4.7% +/- 6.0%, P < or =
.02), a significant increase in serum ferritin (736% +/- 717%, P < or = .001),
and a significant reduction in platelet count (49% +/- 12%, P < or = .0001) was
observed after administration of IL-10. IL-10 significantly (P < or = .02)
decreased CYP3A activity 12% +/- 17%, as reflected by midazolam clearance. CYP2C9
activity was significantly (P < or = .005) increased by 38% +/- 35%, as reflected
by the tolbutamide urinary metabolic ratio and oral clearance. However,
administration of IL-10 resulted in a 40% increase in the fraction unbound of
tolbutamide. Therefore no difference in the unbound clearance of tolbutamide was
observed between placebo (23.3 +/- 9.7 L/h) or IL-10 (23.5 +/- 11.4 L/h)
administration. No significant changes in either CYP1A2 or CYP2D6 activities were
observed between placebo and treatment arms of the study. CONCLUSION: IL-10
administration resulted in an acute-phase response. Administration of IL-10 did
not alter CYP1A2, CYP2C9, and CYP2D6 activities. CYP3A-mediated biotransformation
was reduced by administration of IL-10.
PMID- 10668853
TI - CYP3A4 allelic variants with amino acid substitutions in exons 7 and 12: evidence
for an allelic variant with altered catalytic activity.
AB - OBJECTIVE: To determine the existence of mutant and variant CgammaP3A4 alleles in
three racial groups and to assess functions of the variant alleles by
complementary deoxyribonucleic acid (cDNA) expression. METHODS: A bacterial
artificial chromosome that contains the complete CgammaP3A4 gene was isolated and
the exons and surrounding introns were directly sequenced to develop primers to
polymerase chain reaction (PCR) amplify and sequence the gene from lymphocyte
DNA. DNA samples from Chinese, black, and white subjects were screened. Mutating
the affected amino acid in the wild-type cDNA and expressing the variant enzyme
with use of the baculovirus system was used to functionally evaluate the variant
allele having a missense mutation. RESULTS: To investigate the existence of
mutant and variant CgammaP3A4 alleles in humans, all 13 exons and the 5'-flanking
region of the human CgammaP3A4 gene in three racial groups were sequenced and
four alleles were identified. An A-->G point mutation in the 5'-flanking region
of the human CgammaP3A4 gene, designated CgammaP3A4*1B, was found in the three
different racial groups. The frequency of this allele in a white population was
4.2%, whereas it was 66.7% in black subjects. The CgammaP3A4*1B allele was not
found in Chinese subjects. A second variant allele, designated CgammaP3A4*2,
having a Ser222Pro change, was found at a frequency of 2.7% in the white
population and was absent in the black subjects and Chinese subjects analyzed.
Baculovirus-directed cDNA expression revealed that the CYP3A4*2 P450 had a lower
intrinsic clearance for the CYP3A4 substrate nifedipine compared with the wild
type enzyme but was not significantly different from the wild-type enzyme for
testosterone 6beta-hydroxylation. Another rare allele, designated CgammaP3A4*3,
was found in a single Chinese subject who had a Met445Thr change in the conserved
heme-binding region of the P450. CONCLUSIONS: These are the first examples of
potential function polymorphisms resulting from missense mutations in the
CgammaP3A4 gene. The CgammaP3A4*2 allele was found to encode a P450 with
substrate-dependent altered kinetics compared with the wild-type P450.
PMID- 10668854
TI - Deficient cotinine formation from nicotine is attributed to the whole deletion of
the CYP2A6 gene in humans.
AB - Nicotine is mainly metabolized to cotinine by cytochrome P450 (CYP) 2A6. Large
interindividual differences in nicotine metabolism have been reported in humans.
The purpose of this study was to clarify the relationship between the poor
metabolism of nicotine and the existence of the CgammaP2A6v1 and CgammaP2A6v2
alleles, and a whole deletion allele of the CgammaP2A6 gene. The plasma
concentrations of nicotine and cotinine were measured in 10 healthy subjects
after each smoked one cigarette or chewed one piece of nicotine gum. One subject
showed no detectable cotinine level in plasma when smoking and the lowest
cotinine level when receiving nicotine gum. The subject was regarded as a poor
metabolizer of nicotine by a probit analysis and was found to carry a homozygous
whole deletion allele of the CgammaP2A6 gene. This is the first report to show
that deficient cotinine formation in humans is attributed to the whole deletion
of the CgammaP2A6 gene.
PMID- 10668855
TI - Antipyretic efficacy of aspirin or acetaminophen.
PMID- 10668856
TI - Oxaliplatin: pharmacokinetics and chronopharmacological aspects.
AB - Oxaliplatin is the first clinically available diaminocyclohexane platinum
coordination complex. The drug is non-cross-resistant with cisplatin or
carboplatin and is one of the few active drugs against human colorectal cancer.
Its cytotoxicity is synergistic with fluorouracil and folinic acid (leucovorin),
the reference treatment for this disease. The main cumulative dose-limiting
toxicity of oxaliplatin is peripheral sensory neuropathy. The drug can also
produce diarrhoea, vomiting and haematological suppression. Unlike cisplatin, no
renal failure or peripheral motor neuropathy have been reported and the sensory
neuropathy is partly reversible. Unlike carboplatin, oxaliplatin produces only
mild to moderate haematological toxicity. Oxaliplatin undergoes biotransformation
into aquated forms in the blood, where 3 species can be found: total platinum,
ultrafilterable or 'free' platinum and erythrocyte platinum. Flameless atomic
absorption (FAAS) is used for assaying platinum concentration in various tissues.
Inductively-coupled plasma mass spectrometry (ICP-MS), with a >10-fold lower
sensitivity threshold than FAAS, was also used for the determination of
oxaliplatin pharmacokinetics. The pharmacokinetics of oxaliplatin are described
by a 3-compartment model. The drug rapidly crosses the cellular membrane as a
result of its lipophilicity. Hence, at the end of a 2-hour infusion,
approximately 40% of the blood platinum is found in erythrocytes. The
distribution half-life of ultrafiltrated plasma platinum ranges from 10 to 25
minutes and its terminal elimination half-life is 26 hours (determined with FAAS)
or 270 hours (ICP-MS). The elimination half-life of erythrocytic platinum is 12
to 50 days, close to that of erythrocytes. 30 to 50% of the platinum is recovered
in the urine within 2 to 5 days, with renal clearance accounting for half of the
total clearance of ultrafiltrated platinum. The total clearance of this species
is correlated with the glomerular filtration rate. No pharmacokinetic
pharmacodynamic relationship has been established for oxaliplatin.
Pharmacokinetic alterations produced by fluorouracil + folinic acid or irinotecan
were minimal if any. The prolonged stability of oxaliplatin makes it suitable for
continuous infusions over 4 to 5 days, with a delivery rate which can be either
constant or chronomodulated (peak rate at 1600h), using programmable ambulatory
pumps. Chronomodulation significantly reduces toxicity and improves antitumour
activity as compared with constant rate infusion. These differences in
pharmacodynamic properties were paralleled by differences in plasma concentration
time courses. The different drug concentration profiles achieved with different
infusional modalities may be useful tools for understanding the relationship
between the pharmacokinetics and pharmacodynamics of oxaliplatin and may lead to
further optimisation of its administration schedule and its combination with
other drugs.
PMID- 10668857
TI - Osmotherapy for elevated intracranial pressure: a critical reappraisal.
AB - The administration of osmotic agents is one of the principal strategies to lower
elevated intracranial pressure (ICP) and to increase cerebral perfusion pressure.
Of the 3 osmotic agents frequently used (mannitol, glycerol and sorbitol), each
has characteristic advantages and disadvantages. In addition to renal filtration,
sorbitol [elimination half-life (t1/2beta) approximately 1h] and glycerol
(t1/2beta 0.2 to 1h) are metabolised, mainly by the liver. The risk of these
compounds accumulating in patients with renal insufficiency is low. However, both
compounds frequently affect glucose metabolism, leading to an increase in the
serum glucose concentration. Mannitol is almost exclusively renally filtered and
possesses the slowest elimination from serum (t1/2beta 2 to 4h). The t1/2beta of
mannitol is markedly increased in patients with renal insufficiency, but it does
not interfere with glucose metabolism. Entry into the cerebrospinal fluid (CSF)
is highest with glycerol [CSF: serum ratio of the areas under the concentration
time curves (AUC(CSF): AUCs) approximately 0.25], intermediate with mannitol
(AUC(CSF): AUCs approximately 0.15) and lowest with sorbitol (AUC(CSF): AUCs
approximately 0.10). The elimination of all osmotic agents from the CSF
compartment is substantially slower than from serum. During the elimination
phase, the CSF-to-serum osmotic gradient is temporarily reversed. This is one
cause of the paradoxical rise of ICP above the pretreatment level sometimes
observed with osmotherapeutics. The ability of mannitol, glycerol and sorbitol to
lower elevated ICP has been extensively documented. However, whether the use of
osmotic agents, particularly with repeated application, improves outcome remains
unproven. Therefore, these agents should only be used to treat manifest
elevations of ICP, not for prophylaxis of brain oedema.
PMID- 10668860
TI - Sequence variation of ribosomal internal transcribed spacers (ITS) in
commercially important Phytoseiidae mites.
AB - Preliminary work is needed to assess the usefulness of different markers at
different taxonomic scales when a new group is analyzed, such as the commercially
important Phytoseiidae mites. We investigate here the level of sequence variation
of the nuclear ribosomal spacers ITS 1 and 2 and the 5.8S gene in six species of
Phytoseiidae: Neoseiulus culifornicus, N. fallacis, Euseius concordis,
Metaseiulus occidentalis, Typhlodromus pyri and Phytoseiulus persimilis. As
expected, the 5.8S gene (148 base pairs) is markedly conserved and displays
little variation in between genera comparisons. ITS1 and ITS2 show contrasting
patterns: while the ITS2 is short (80-89 bp) and shows little variation, the ITS1
is longer (303-404 bp) and is very variable in sequence. This fact compromises
reliable nucleotide homologies when comparing the genera. The comparison of ITS1
sequence similarity at the species level might be useful for species
identification, however, the value of ITS in taxonomic studies does not extend to
the level of the family. The intraspecific variations of ITS were investigated in
three species: N. californicus, N. fallacis and E. concordis. The first species
has identical ITS1 sequences and the last two display low polymorphism (2
nucleotide substitutions). The ITS2 and 5.8S sequences were identical in all
three subspecies comparisons.
PMID- 10668858
TI - Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome
P450 3A4 inhibition.
AB - Drug interactions occur when the efficacy or toxicity of a medication is changed
by administration of another substance. Pharmacokinetic interactions often occur
as a result of a change in drug metabolism. Cytochrome P450 (CYP) 3A4 oxidises a
broad spectrum of drugs by a number of metabolic processes. The location of
CYP3A4 in the small bowel and liver permits an effect on both presystemic and
systemic drug disposition. Some interactions with CYP3A4 inhibitors may also
involve inhibition of P-glycoprotein. Clinically important CYP3A4 inhibitors
include itraconazole, ketoconazole, clarithromycin, erythromycin, nefazodone,
ritonavir and grapefruit juice. Torsades de pointes, a life-threatening
ventricular arrhythmia associated with QT prolongation, can occur when these
inhibitors are coadministered with terfenadine, astemizole, cisapride or
pimozide. Rhabdomyolysis has been associated with the coadministration of some 3
hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors ('statins') and CYP3A4
inhibitors. Symptomatic hypotension may occur when CYP3A4 inhibitors are given
with some dihydropyridine calcium antagonists, as well with the phosphodiesterase
inhibitor sildenafil. Excessive sedation can result from concomitant
administration of benzodiazepine (midazolam, triazolam, alprazolam or diazepam)
or nonbenzodiazepine (zopiclone and buspirone) hypnosedatives with CYP3A4
inhibitors. Ataxia can occur with carbamazepine, and ergotism with ergotamine,
following the addition of a CYP3A4 inhibitor. Beneficial drug interactions can
occur. Administration of a CYP3A4 inhibitor with cyclosporin may allow reduction
of the dosage and cost of the immunosuppressant. Certain HIV protease inhibitors,
e.g. saquinavir, have low oral bioavailability that can be profoundly increased
by the addition of ritonavir. The clinical importance of any drug interaction
depends on factors that are drug-, patient- and administration-related.
Generally, a doubling or more in plasma drug concentration has the potential for
enhanced adverse or beneficial drug response. Less pronounced pharmacokinetic
interactions may still be clinically important for drugs with a steep
concentration-response relationship or narrow therapeutic index. In most cases,
the extent of drug interaction varies markedly among individuals; this is likely
to be dependent on interindividual differences in CYP3A4 tissue content, pre
existing medical conditions and, possibly, age. Interactions may occur under
single dose conditions or only at steady state. The pharmacodynamic consequences
may or may not closely follow pharmacokinetic changes. Drug interactions may be
most apparent when patients are stabilised on the affected drug and the CYP3A4
inhibitor is then added to the regimen. Temporal relationships between the
administration of the drug and CYP3A4 inhibitor may be important in determining
the extent of the interaction.
PMID- 10668859
TI - Clinical pharmacokinetics of transdermal opioids: focus on transdermal fentanyl.
AB - Transdermal delivery allows continuous systemic application of opioids through
the intact skin. This review analyses the pharmacokinetic properties of
transdermal opioid administration in the context of clinical experience, with a
focus on fentanyl. A transdermal therapeutic system (TTS) for fentanyl has been
developed. The amount of fentanyl released is proportional to the surface area of
the TTS, which is available in different sizes. After the first application of a
TTS, a fentanyl depot concentrates in the upper skin layers and it takes several
hours until clinical effects are observed. The time from application to minimal
effective and maximum serum concentrations is 1.2 to 40 hours and 12 to 48 hours,
respectively. Steady state is reached on the third day, and can be maintained as
long as patches are renewed. Within each 72-hour period, serum concentrations
decrease gradually over the second and third days. When a TTS is removed,
fentanyl continues to be absorbed into the systemic circulation from the
cutaneous depot. The terminal half-life for TTS fentanyl is approximately 13 to
25 hours. The interindividual variability of serum concentrations, partly caused
by different clearance rates, is markedly larger than the intraindividual
variability. The effectiveness of TTS fentanyl was first demonstrated in acute
postoperative pain. However, the slow pharmacokinetics and large variability of
TTS fentanyl, together with the relatively short duration of postoperative pain,
precluded adequate dose finding and led to inadequate pain relief or, especially,
a high incidence of respiratory depression; such use is now contraindicated.
Conversely, in cancer pain, TTS fentanyl offers an interesting alternative to
oral morphine, and its effectiveness and tolerability in this indication has been
demonstrated by a number of trials. Its usefulness in chronic pain of
nonmalignant origin remains to be confirmed in controlled trials. In general, TTS
fentanyl produces the same adverse effects as other opioids, mainly sedation,
nausea, vomiting and constipation. In comparison with oral morphine, TTS fentanyl
causes fewer gastrointestinal adverse events. The risk of hypoventilation is
comparatively low in cancer patients. Sufentanil and buprenorphine may also be
suitable for transdermal delivery, but clinical results are not yet available.
Transdermal morphine is only useful if applied to de-epithelialised skin.
However, iontophoresis may allow transdermal administration of opioids, including
morphine, with a rapid achievement of steady state concentrations and the ability
to adjust delivery rates. This would be beneficial for acute and/or breakthrough
pain, and initial clinical trials are in progress.
PMID- 10668861
TI - Chorioptic mange (Acarina: Psoroptidae) in domestic and wild ruminants in Israel.
AB - In a 20-year-survey, 9364 dairy cattle in 324 herds kept under a zero-grazing
management, 1252 beef cattle in 46 herds grazing all the year round, 3347 sheep
in 134 herds (only 26 are grazing herds), and 872 goats in 47 herds (only 20 are
grazing) were examined. The mites collected from cattle were identified as
Chorioptes texanus only, and those from sheep, goats and gazelles were identified
as C. bovis. Chorioptic mange was not diagnozed in grazing beef cattle, ibexes
and housed animals (as compared to grazing herds), and in rams and billy goats.
Holstein-Israeli bulls kept in insemination centres were not clinically infested,
whereas four Charolais bulls were infested with chorioptic mange. Infestation
rate was higher in older animals than in younger ones. Hoggets and young goats
over 10 months and heifers over 13 months were found clinically infested with
Choriopic mites. Lesions were not usually extensive and occurred mainly in
predilection sites. The ocular form in sheep and the groin form in goats are very
uncommon and apparently are reported for the first time. Chorioptic mange was
recorded generally throughout the year. In our study seasonal distribution could
not be demonstrated in cattle, while in sheep and goats the highest infestation
rate occurred in February to March and the lowest in August and September.
PMID- 10668862
TI - High temperatures eliminate Wolbachia, a cytoplasmic incompatibility inducing
endosymbiont, from the two-spotted spider mite.
AB - Wolbachia can induce cytoplasmic incompatibility (CI) in the arrhenotokous two
spotted spider mite between uninfected females and infected males. Cytoplasmic
incompatibility is expressed through a male-biased sex ratio and a low
hatchability, and can be suppressed by removing Wolbachia from spider mites
reared on a diet with antibiotics. Here we investigated whether heat-treatment
can elimate Wolbachia from infected mites. Using a PCR assay with a Wolbachia
specific primer pair (ftsZ), and by standard crosses, we were able to show that
71 per cent of the mites had lost the Wolbachia infection after rearing the
infected population at 32+/-0.5 degrees C for four generations. The infection
could be completely removed when mites were reared at 32+/-0.5 degrees C for six
generations. Curing through high temperatures could be one of the reasons why
mixed infected/uninfected populations occur in the field. An additional
consequence of rearing mites at 32+/-0.5 degrees C was the shortened development
time. The effect of environmental temperature on the abundance of Wolbachia and
possible behavioural consequences for the spider mite are discussed.
PMID- 10668863
TI - Sequence variations in the Boophilus microplus Bm86 locus and implications for
immunoprotection in cattle vaccinated with this antigen.
AB - Cattle tick infestations constitute a major problem for the cattle industry in
tropical and subtropical regions of the world. Traditional control methods have
been only partially successful, hampered by the selection of chemical-resistant
tick populations. The Boophilus microplus Bm86 protein was isolated from tick gut
epithelial cells and shown to induce a protective response against tick
infestations in vaccinated cattle. Vaccine preparations including the recombinant
Bm86 are used to control cattle tick infestations in the field as an alternative
measure to reduce the losses produced by this ectoparasite. The principle for the
immunological control of tick infestations relies on a polyclonal antibody
response against the target antigen and, therefore, should be difficult to select
for tick-resistant populations. However, sequence variations in the Bm86 locus,
among other factors, could affect the effectiveness of Bm86-containing vaccines.
In the present study we have addressed this issue, employing data obtained with
B. microplus strains from Australia, Mexico, Cuba, Argentina and Venezuela. The
results showed a tendency in the inverse correlation between the efficacy of the
vaccination with Bm86 and the sequence variations in the Bm86 locus (R2 = 0.7).
The mutation fixation index in the Bm86 locus was calculated and shown to be
between 0.02 and 0.1 amino acids per year. Possible implications of these
findings for the immunoprotection of cattle against tick infestations employing
the Bm86 antigen are discussed.
PMID- 10668864
TI - Monooxygenases play only a minor role in resistance to synthetic pyrethroids in
the cattle tick, Boophilus microplus.
AB - We investigated the role of monooxygenases in resistance to synthetic pyrethroids
(SPs) in the cattle tick, Boophilus microplus. We found that monooxygenases play
only a minor role in resistance to SPs in both resistant and susceptible strains
of B. microplus. We blocked the monooxygenases with piperonyl butoxide (PBO) and
simultaneously applied the SPs, flumethrin and cypermethrin to larval B.
microplus. PBO increased the effect of flumethrin (synergism ratios 2.7-8.9) more
than it increased the effect of cypermethrin (synergism ratios 1.9-3.1). Of the
four strains tested, Parkhurst, which is resistant to SPs, was the least affected
by the addition of PBO (synergism ratios after cypermethrin was applied 1.9;
after flumethrin 2.7) whereas N.R.F.S., the strain susceptible to SPs, was the
most affected by synergism between PBO and SPs (synergism ratio after
cypermethrin was applied 3.1; after flumethrin 8.9). We hypothesize that B.
microplus lacks monooxygenases capable of conferring resistance to SPs because it
and its recent ancestors were blood-feeders rather than herbivores.
PMID- 10668865
TI - Detecting resistance to organophosphates and carbamates in the cattle tick
Boophilus microplus, with a propoxur-based biochemical test.
AB - Rapid and sensitive detection of resistance to insecticides in arthropods is
needed. In the cattle tick. Boophilus microplus, resistance to a variety of
acaricides is widespread. The most commonly used assay for resistance, the larval
packet test, takes at least two, but generally six weeks for a one-host tick like
B. microplus to complete and may take up to three months to complete for three
host ticks. Here we describe a test for resistance to organophosphate acaricides
that can be used on larvae and adult ticks which takes less than 24 hours. The
test measures the difference in acetylcholinesterase (AChE) activity in
homogenates of ticks in the presence and absence of propoxur, a carbamate
acaricide. We found clear discrimination of organophosphate-susceptible and
organophosphate-resistant adults with 100 microM propoxur. AChE from susceptible
ticks had almost no activity at this concentration of propoxur whereas AChE from
resistant ticks had 67% of its potential activity. AChE from heterozygote ticks
could also be distinguished from AChE from homozygous-susceptible and homozygous
resistant ticks. This is the first biochemical test for resistance to an
acaricide. Rapid, sensitive tests like ours will allow resistance to
organophosphates to be detected soon after it develops in the field, thus, the
spread of resistance might be slowed and the useful life of acaricides extended.
PMID- 10668866
TI - Sequential histopathology at the Rhipicephalus sanguineus tick feeding site on
dogs and guinea pigs.
AB - The tick Rhipicephalus sanguineus is a very common parasite of dogs worldwide.
Dogs seem unable to acquire resistance against this tick species, whereas guinea
pigs demonstrate a very strong resistance following primary infestation. We
studied the inflammatory reaction at the R. sanguineus tick feeding site on dogs
and guinea pigs during primary and tertiary infestations at different time
intervals after attachment. Biopsies were collected after 4, 24, 48 and 96 hours.
Changes that were found in all experimental groups included a cone of cement
around the mouthparts of the tick, epidermal hyperplasia, edema and inflammatory
cell infiltration in the dermis directly underneath the tick attachment site.
Dogs reacted to ticks mainly with neutrophils, particularly after repeated
exposure. Mast cells and mononuclear leukocytes were also present. Guinea pigs
reacted to R. sanguineus mainly with mononuclear cells, eosinophils and
basophils. These cells were particularly numerous after repeated exposure to R.
sanguineus. Our results suggest that basophils and eosinophils are involved in
resistance of guinea pigs to R. sanguineus and that neutrophils in dogs have
little effect against this tick species.
PMID- 10668867
TI - Rural surgery: opportunity or minefield.
PMID- 10668868
TI - Advances in the management of acute respiratory distress syndrome: protective
ventilation.
AB - The approach to mechanical ventilation has been revolutionized by new insights
into the pathogenesis of respiratory failure in acute respiratory distress
syndrome (ARDS). Concepts such as low-volume ventilation, permissive hypercapnia,
inverse ratio ventilation, best and intrinsic positive end-expiratory pressure,
airway shear, pressure volume curves, inflection points, and prone positioning
have radically transformed thinking about ventilator management. Since 1966, more
than 8000 ARDS-related publications have appeared. Studies highlighting the
experimental basis for innovations in mechanical ventilation are presented.
Selected clinical series that exemplify the use of these new strategies are
reviewed, to demonstrate how key experimental and clinical research has altered
our understanding about what works, and why. Mismanagement of mechanical
ventilation causes lung injury and increases mortality. The strategy of
protective ventilation has provided the first substantial reduction of mortality
in the history of ARDS.
PMID- 10668869
TI - Internal drainage of giant acute pseudocysts: the role of video-assisted
pancreatic necrosectomy.
AB - BACKGROUND: Internal drainage of giant pancreatic pseudocysts secondary to acute
pancreatitis is frequently complicated with postoperative retroperitoneal
infection and hemorrhage. Recent data suggest that the risk factor is
unrecognized pancreatic necrosis; presumably, pancreatic necrosis becomes
infected with bacteria introduced by the cystoenteric anastomosis. HYPOTHESIS:
Video-assisted pancreatic necrosectomy, performed at the time of internal
drainage, may prevent postoperative retroperitoneal complications in patients
with giant acute pseudocysts. DESIGN: A consecutive case-series. SETTING: An
urban, university-affiliated, tertiary referral center. PATIENTS: Ten consecutive
patients with acute pseudocysts measuring 10 cm or more in major diameter. The
mean extent of pancreatic necrosis, as shown by contrast-enhanced computed
tomography, was 50%. All patients were operated on electively, at an average time
of 7.7 weeks from onset of the attack to surgical treatment. INTERVENTION:
Through a midline incision, a 4-cm opening is made at the base of the pseudocyst.
Standard laparoscopic instruments are introduced into the pseudocyst and video
assisted pancreatic necrosectomy is performed. The opening is then anastomosed to
a Roux-en-Y limb of the jejunum. MAIN OUTCOME MEASURES: Feasibility and safety of
video-assisted pancreatic necrosectomy, postoperative morbidity and mortality,
hospital stay, and resolution of pseudocysts. RESULTS: Complete necrosectomy was
safely performed throughout. There were neither postoperative retroperitoneal
complications nor mortality. Mean hospital stay was 8.2 days and all pseudocysts
resolved at a mean follow-up of 6.9 months. CONCLUSIONS: Video-assisted
pancreatic necrosectomy at the time of internal drainage seems to prevent
postoperative retroperitoneal complications in patients with giant acute
pseudocysts. Depending on appropriate surgical timing, video-assisted
necrosectomy is a feasible and safe procedure.
PMID- 10668870
TI - Risk factors for postoperative hypocalcemia after surgery for primary
hyperparathyroidism.
AB - HYPOTHESIS: A variety of clinical and biochemical variables may be associated
with hypocalcemia after surgery for parathyroid adenoma. DESIGN: A prospective
study of patients who underwent surgery for solitary parathyroid adenoma.
SETTING: A university hospital department of surgery. PATIENTS: Eighty-six
consecutive patients who underwent surgery for solitary parathyroid adenoma.
INTERVENTION: Parathyroidectomy according to the principles of unilateral neck
exploration. MAIN OUTCOME MEASURES: Clinical and biochemical risk factors for
early (< or =4 days after surgery) and late (1 year after surgery) postoperative
symptomatic and biochemical hypocalcemia. RESULTS: Twenty-two patients developed
early symptomatic hypocalcemia. The difference in total serum calcium levels
between patients, with and without early symptomatic hypocalcemia, was evident on
the third and fourth postoperative days. Serum level of osteocalcin greater than
6.0 microg/L, bilateral neck exploration, and history of cardiovascular disease
were risk factors for symptomatic hypocalcemia (odds ratios [95% confidence
intervals]: 4.4 [1.4-14.1], 3.8 [1.3-11.6], and 0.1 [0.02-0.60], respectively).
Patients with up to 1 risk factor had a possibility of only 7% to develop early
symptomatic hypocalcemia. One year after surgery, 16 patients had low levels of
total serum calcium (late biochemical hypocalcemia) and were asymptomatic.
Preoperative intermittent hypercalcemia was associated with an increased risk for
late biochemical hypocalcemia (odds ratio, 3.9; 95% confidence interval, 1.0
16.3). CONCLUSIONS: Clinical and biochemical risk factors for early and late
postoperative hypocalcemia in patients who underwent surgery for solitary
parathyroid adenoma were found. A clinically useful prognostic index for early
symptomatic hypocalcemia was constructed using these risk factors.
PMID- 10668871
TI - Evaluation of magnetic resonance cholangiography in the management of bile duct
stones.
AB - HYPOTHESIS: Magnetic resonance cholangiography (MRC) offers the potential for
accurate, noninvasive detection of common bile duct stones (CBDSs) before
cholecystectomy, and for a consequent reduction in the incidence of preoperative
negative diagnoses associated with endoscopic retrograde cholangiography (ERC).
DESIGN: Prospective cohort study: MRC results were correlated with ERC (high-risk
patients) or intraoperative cholangiography (moderate-risk patients). SETTING: A
university hospital providing primary, secondary, and tertiary care. PATIENTS:
Seventy patients with suspected CBDSs scheduled to undergo elective
cholecystectomy between April 15, 1997, and September 30, 1998. Forty patients
were considered at high risk and 30 at moderate risk for CBDSs, according to
results of liver function tests and sonograms of the upper abdomen. MAIN OUTCOME
MEASURES: Confirmation or exclusion of CBDSs by MRC was assessed by a panel of
radiologists who were unaware of the ERC results. Results of ERC and
intraoperative cholangiography were analyzed by the investigating
gastroenterologists or surgeon. RESULTS: Results of MRC were positive for CBDSs
in 21 (52%) of 40 high-risk patients, a finding confirmed by preoperative ERC in
19 (90%) of 21 patients. Results of MRC were positive for CBDSs in 6 (20%) of 30
moderate-risk patients, all of which were confirmed by intraoperative
cholangiography. Finally, CBDSs were present in 19 (48%) of 40 high-risk patients
and 6 (20%) of 30 moderate-risk patients (P = .02). Overall sensitivity and
specificity of MRC were 100% and 95.6%, respectively; the positive and negative
predictive values were 92.6% and 100%, respectively. CONCLUSIONS: Magnetic
resonance cholangiography is a reliable, noninvasive method for the detection or
exclusion of CBDSs, and seems to reduce the frequency of negative diagnoses
associated with ERC. Magnetic resonance cholangiography revealed no CBDSs in 19
(48%) of 40 patients at high risk for CBDSs. Thus, MRC-based diagnosis has the
potential to reduce the number of invasive preoperative diagnostic procedures and
their associated risks and overall health care costs.
PMID- 10668872
TI - Management of benign biliary strictures: biliary enteric anastomosis vs
endoscopic stenting.
AB - HYPOTHESIS: Although advances in endoscopic procedures have provided alternative
options for relieving biliary obstructions, the overall chance of cure for
patients with benign biliary stricture is the same using surgical or endoscopic
treatment. DESIGN: Case-control study. SETTING: Tertiary care university
hospital. PATIENTS: Of 163 patients referred for treatment with diagnoses of
benign strictures of the common bile duct between January 1, 1975, and July 1,
1998, we studied 42 patients with postcholecystectomy stricture and a follow-up
longer than 60 months. Twenty of these patients were treated with endoscopic
stenting and 22 with surgery (hepaticojejunostomy, choledochojejunostomy, or
intrahepatic cholangiojejunostomy). MAIN OUTCOME MEASURES: Postoperative
mortality and morbidity and long-term outcome. The rate of restenosis was also
determined. RESULTS: Morbidity occurred more frequently in patients treated with
endoscopic procedures than with surgical ones (9 vs 2; P = .34). Hospital
mortality was 0%. Surgery achieved excellent or good long-term outcome in 17 of
22 patients. Endoscopic biliary stenting was successful in 16 of 20 patients.
Overall, excellent or good outcomes were achieved in 34 patients (81%).
CONCLUSION: The ability to achieve steady, long-term results confirms
hepaticojejunostomy as the best procedure in the treatment of benign biliary
strictures, even if endoscopic procedures are gaining a new role in the treatment
of a greater number of patients.
PMID- 10668873
TI - Ultrasound can estimate the pathologic size of infiltrating ductal carcinoma.
AB - HYPOTHESIS: Ultrasound (US) of the breast will accurately measure breast tumor
size when compared with size as determined by pathologic examination. DESIGN:
Retrospective case series. SETTING: University hospital-based breast center.
PATIENTS: Thirty-five women with a diagnosis of breast cancer who had US as a
component of their evaluation. MAIN OUTCOME MEASURE: Tumor size as measured by US
compared with size measured by pathologic examination. RESULTS: Size measured by
US ranged from 0.45 to 3.81 cm. Size measured by pathologic examination ranged
from 0.5 to 5 cm. The mean difference of size measured by US vs pathologic size
was 0.4 cm (P = .01). When only tumors with invasive ductal histology are
evaluated, the mean difference in size is 0.33 cm (P = .008). The range of
difference was -1.6 cm to +0.42 cm. Seventeen percent of invasive ductal tumors
were underestimated by more than 1 cm; none were underestimated by more than 2
cm. CONCLUSIONS: This study demonstrates that, although US tends to underestimate
the pathologic tumor size, 83% of invasive ductal tumors fall within a 1-cm and
100% fall within a 2-cm extension of the US-measured tumor size. Therefore, it is
possible to use US to monitor the extent of treatment size when developing very
localized therapeutic tools.
PMID- 10668874
TI - Effects of fluconazole administration in critically ill patients: analysis of
bacterial and fungal resistance.
AB - HYPOTHESIS: The administration of fluconazole in intensive care unit (ICU)
patients leads to the emergence of bacterial and fungal resistance. DESIGN:
Retrospective analysis of 2 patient cohorts: (1) critically ill patients treated
in surgical, trauma, and medical ICUs between June 1997 and January 1999 who did
and did not receive fluconazole; and (2) ICU patients with fungal infections and
sensitivity testing results from June 1994 to December 1998. SETTING: University
affiliated tertiary care hospital. PATIENTS: The first cohort included 99 ICU
patients with documented microorganism culture(s) who were treated with (n = 50)
or without (n = 49) fluconazole; the second cohort included 38 patients with
Candida species infection, identification, and antifungal susceptibility testing.
RESULTS: Mortality (40% vs 20%; P = .03) and hospital length of stay (33.8 vs
25.6 days; P = .04) were higher in the patients treated with fluconazole compared
with patients not treated with fluconazole. The ICU length of stay was also
higher in patients treated with fluconazole (23.7 vs 15.1 days; P = .009). An
increase in bacterial resistance occurred in patients after fluconazole treatment
as opposed to bacterial resistance of patients who were treated for bacterial
microorganism(s) without fluconazole (16% vs 4%; P = .049). Comparison of patient
populations with Candida species identification before and after December 1997
showed an increase in Candida species resistance to fluconazole (11% vs 36%; P =
.16), respectively. Fungal strains were dominated by a combination of Candida
albicans and Candida glabrata in both populations (60% [before 1998] vs 82%
[after 1998]), with an emergence of Candida non-albicans species tolerant to
fluconazole. The amount of fluconazole administered and the number of patients
receiving fluconazole treatment in the ICUs has also increased when comparing
both periods. CONCLUSIONS: Comparison of critically ill patient populations with
and without fluconazole treatment found increased mortality and longer hospital
and ICU lengths of stay in the fluconazole-treated group. This group also had
higher bacterial pathogen resistance to antibiotics after fluconazole
administration compared with bacterial resistance of patients without fluconazole
treatment. Our results warrant concern regarding worsening bacterial infections,
increased mortality, and an increase in Candida resistance to fluconazole from
increased use in ICU patients, with a shift in yeast infection that is more
difficult to treat.
PMID- 10668876
TI - Accuracy of ultrasonography in the diagnosis of peritonitis compared with the
clinical impression of the surgeon.
AB - HYPOTHESIS: Peritonitis is a well-known indication for surgery, but its
preoperative cause usually is not established. We hypothesize that abdominal
ultrasonography is superior to the clinical impression of the surgeon in
detecting the cause of peritonitis. DESIGN: A prospective case series. SETTING: A
major university hospital in Taiwan, Republic of China. PATIENTS AND METHODS: One
hundred two patients with a diagnosis of peritonitis admitted to the Department
of Emergency Medicine, National Taiwan University Hospital, Taipei, were included
in this study. All 102 patients underwent an abdominal ultrasonographic
examination; and the ultrasonographic findings of these patients were classified
into 2 categories: positive findings and normal screening results. The accuracy
of clinical impression in detecting the cause of peritonitis was compared with
the accuracy of abdominal ultrasonography. RESULTS: Ultrasonography and clinical
impression accurately diagnosed the peritonitis in 85 (83.3%) and 52 (51.0%) of
the patients, respectively. The difference between ultrasonography and clinical
impression in the diagnosis of peritonitis was significant (P<.001). Among 45
patients without a preoperative clinical diagnosis, a diagnosis was made by
ultrasonography for 32 (71%) of them. There were a total of 98 patients with
positive ultrasonographic findings, and 4 patients had normal screening results.
Of the 98 patients with positive ultrasonographic findings undergoing surgery,
all had abdominal pathological characteristics. The 4 patients with normal
screening results received nonoperative treatment. CONCLUSIONS: Ultrasonography
is a more sensitive technique than clinical judgment in diagnosing peritonitis.
Ultrasonography may be a useful diagnosing modality in patients with peritonitis
in whom the clinical cause is unclear.
PMID- 10668875
TI - Repair of chronic anorectal fistulae using commercial fibrin sealant.
AB - HYPOTHESIS: Commercially produced fibrin sealant can be used to completely close
both simple and complex fistulae in ano. METHODS: A 29-patient prospective
nonrandomized clinical trial was performed. In the operating room, the patient
underwent an examination with anesthesia and the primary and secondary fistula
tract openings were attempted to be identified. The fistula tract was curetted
and fibrin sealant was injected into the secondary fistula tract opening until
fibrin sealant was seen coming from the primary opening. A petroleum jelly gauze
was then applied over the secondary opening and the patient was sent home. Follow
up visits were scheduled for 1 week, 1 month, 3 months, and 1 year later.
RESULTS: Twenty-nine consecutive patients received fibrin sealant injections for
their fistulae in ano, with a mean follow-up of 6 months. Two patients had a
history of Crohn disease (regional enteritis) and 2 patients had human
immunodeficiency virus infection. Overall, 17 (68%) of 25 patients have had
successful closure of their fistula with 4 patients lost to follow-up. Two
patients required reinjection with fibrin sealant, and neither of these
subsequently had closure. One of the 2 patients with Crohn disease had closure,
as well as 1 human immunodeficiency virus-positive patient. In addition, there
has been no evidence of incontinence or complications related to the use of
fibrin sealant in this procedure. CONCLUSIONS: Initial results in the treatment
of chronic anorectal fistulae using commercial fibrin sealant are optimistic, but
require further support through longer follow-up data. Fibrin sealant treatment
of anorectal fistulae offers a unique mode of management which is safe, simple,
and easy for the surgeon to perform. By using fibrin sealant, the patient avoids
the risk of fecal incontinence and the discomfort of prolonged wound healing that
may be associated with fistulotomy.
PMID- 10668877
TI - Restoration of body temperature to normothermia during resuscitation following
trauma-hemorrhage improves the depressed cardiovascular and hepatocellular
functions.
AB - HYPOTHESIS: Rewarming the body to 37 degrees C during resuscitation following
trauma-hemorrhage has salutary effects on cardiovascular and hepatocellular
functions. DESIGN, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Male rats underwent
laparotomy (trauma induced) and were then bled to and maintained at a mean
arterial pressure of 40 mm Hg until 40% of the maximum shed blood volume was
returned in the form of Ringer lactate solution. Rats were exposed to ambient
temperature and allowed to become hypothermic during hemorrhage. The animals were
then resuscitated with 4 times the volume of shed blood with Ringer lactate
solution for 60 minutes. In 1 group, the body temperature was rewarmed to 37
degrees C during resuscitation. In another group, the body temperature was
maintained at hypothermia (32 degrees C) for 4 hours after resuscitation. In an
additional group, the body temperature was kept at 37 degrees C during hemorrhage
and resuscitation. At 4 hours after resuscitation, the rats were returned to a
room with ambient temperature. Various in vivo heart performance variables
(maximal rate of pressure increase and decrease), cardiac output, hepatocellular
function, and plasma IL-6 level were determined at 24 hours after resuscitation.
RESULTS: Either maintenance of normothermia during hemorrhage or prolonged
hypothermia following resuscitation had deleterious effects on cardiovascular
variables and hepatocellular function and up-regulated plasma IL-6 levels. In
contrast, rewarming the body to 37 degrees C during resuscitation improved
cardiac contractility, cardiac output, and hepatocellular function and reduced
plasma IL-6 level. CONCLUSION: Since rewarming the body temperature to
normothermia during resuscitation improved depressed cardiovascular and
hepatocellular functions, this should be considered as a useful adjunct to fluid
resuscitation after trauma-hemorrhage.
PMID- 10668878
TI - Stage III colon cancers: why adjuvant chemotherapy is not offered to elderly
patients.
AB - HYPOTHESIS: Adjuvant chemotherapy is not offered to elderly patients with stage
III colon cancer. DESIGN: A retrospective review of hospital and office records.
SETTING: A suburban community hospital. PATIENTS: The medical records of 69
patients with stage III colon cancer were reviewed. All identified from the Tumor
Registry at Jersey Shore Medical Center, Neptune, NJ, were included in this
study. RESULTS: Thirty-five patients (51%) did not receive adjuvant chemotherapy.
After adjusting for age, women were 5.8 times less likely to receive chemotherapy
(P = .002). Patients not receiving chemotherapy were significantly older (78.7 vs
70.4 years; P = .003) than those who received adjuvant chemotherapy. There was no
relation found between the year of diagnosis and the administration of
chemotherapy. There were 4 major reasons for not receiving chemotherapy: (1) not
offered (n = 12, 34%), (2) refused (n = 11, 31%), (3) too old (n = 7, 20%), and
(4) significant concomitant disease (n = 5, 14%). CONCLUSIONS: A large group of
elderly patients who had been surgically treated for colon cancer and who were
eligible for adjuvant chemotherapy either were not referred for treatment or
refused treatment. This suggests a bias on the part of surgeons, primary care
physicians, and patients against the use of chemotherapy in elderly patients.
PMID- 10668879
TI - Long-term results of subcutaneous parathyroid grafts in uremic patients.
AB - HYPOTHESIS: Parathyroid glands are normally surrounded (entirely or partially) by
fatty tissue. Subcutaneous parathyroid grafts are thus located in a normal
environment. Therefore, we postulated that the late results of subcutaneous
implantation of parathyroid tissue in uremic patients should be at least as good
as those reported for intramuscular grafting. We also challenged the idea that
the recurrence rate of renal hyperparathyroidism after surgery depended solely on
the type of hyperplasia (diffuse vs nodular) observed in the implanted tissue.
DESIGN: A retrospective study of a series of patients without loss to follow-up.
SETTING: A university hospital and 9 affiliated dialysis units. PATIENTS AND
INTERVENTIONS: Fifty-nine patients (33 women and 26 men) operated on for renal
hyperparathyroidism underwent the resection of at least 4 parathyroid glands
followed by presternal subcutaneous implantation of parathyroid tissue. They were
followed up for 12 to 130 months (median, 38 months). MAIN OUTCOME MEASURES:
Failure of treatment, recurrence of disease, and hypoparathyroidism. RESULTS:
During the study period, 9 patients had to undergo another operation: 2 (3%) for
persistent hyperparathyroidism due to a fifth ectopic gland and 7 (12%) for
recurrence of hyperparathyroidism resulting from hypertrophy of the subcutaneous
grafts. Four patients received a kidney transplant. The prevalence of
hypoparathyroidism (intact parathyroid hormone serum level <1.6 pmol/L with a
normal or low serum calcium concentration) was 14% (8 of 59 patients), and the
curve representing the distribution of intact parathyroid hormone serum
concentrations among operated on patients was shifted to the left when compared
with the curve of patients who underwent hemodialysis and who had no indication
for parathyroid surgery. In this latter group, the peak of the curve was situated
between 1 and 2 times the upper normal limit, while it was in the normal range 12
to 130 months after total parathyroidectomy and subcutaneous parathyroid
autotransplantation. No relation was observed between the recurrence rate of the
disease and the histological characteristics of the parathyroid grafts. Also,
their function was not influenced by the presence or absence of aluminum deposits
in bone biopsy specimens that were obtained at the time of cervical exploration.
CONCLUSIONS: The late results of total parathyroidectomy and presternal
subcutaneous grafting compare favorably with the published data on other surgical
techniques proposed for the treatment of renal hyperparathyroidism. The ease with
which the hypertrophied grafts are removed when the disease recurs warrants
further use of this procedure.
PMID- 10668880
TI - Optimizing cardiovascular gene therapy: increased vascular gene transfer with
modified adenoviral vectors.
AB - BACKGROUND: Adenovirus is widely used as a vector for gene transfer to the
vasculature. However, the efficiency of these vectors can be limited by
ineffective viral-target cell interactions. Viral attachment, which largely
determines adenoviral tropism, is mediated through binding of the adenoviral
fiber coat protein to the Coxsackievirus and adenovirus receptor, while
internalization follows binding of the adenoviral RGD motif to alpha(v)-integrin
receptors. Modifications of the fiber coat protein sequence have been successful
for targeting the adenovirus to more prevalent receptors in the vasculature,
including heparan sulfate-containing receptors and alpha(v)-integrin receptors.
HYPOTHESIS: Modified adenoviral vectors targeted to receptors more prevalent in
the vasculature result in an increased transfer efficiency of the virus in vitro
and in vivo even in the presence of clinically relevant doses of heparin. DESIGN:
We tested 2 modified E1- and E3-deleted Ad5 type adenoviral vectors containing
the beta-galactosidase gene. AdZ.F(pK7) contains multiple positively charged
lysines in the fiber coat protein that target the adenovirus to heparan sulfate
receptors, while AdZ.F(RGD) contains an RGD integrin-binding sequence in the
fiber coat protein that allows binding to alpha(v)-integrin receptors. The gene
transfer efficiency of these modified viruses was compared in rat aortic smooth
muscle cells in vitro and in an in vivo porcine model of balloon-induced arterial
injury. Because of the use of heparin during most vascular surgical procedures
and the concern that heparin might interfere with the binding of AdZ.F(pK7) to
heparan sulfate receptors, the effect of heparin on the in vitro and in vivo
transfer efficiency of these 2 modified adenoviruses was evaluated. RESULTS: In
vitro infection of rat aortic smooth muscle cells with AdZ.F(pK7) and AdZ.F(RGD)
resulted in significantly higher levels of beta-galactosidase expression compared
with the unmodified adenovirus (mean +/- SEM, 1766.3 +/- 89.1 and 44.8 +/- 3.4 vs
10.1 +/- 0.7 mU per milligram of protein; P<.001). Following heparin
administration, the gene transfer efficiency achieved with AdZ.F(pK7) diminished
slightly in a concentration-dependent manner. However, the transfer efficiency
was still greater than with the unmodified virus (mean +/- SEM, 1342.3 +/- 101.8
vs 4.8 +/- 0.4 mU per milligram of protein; P<.001). In vivo, following injury to
the pig iliac artery with a 4F Fogarty balloon catheter, we found that AdZ.F(pK7)
transduced the artery approximately 35-fold more efficiently than AdZ.F and 3
fold more efficiently than AdZ.F(RGD) following the administration of intravenous
heparin, 100 U/kg body weight, and heparinized saline irrigation. CONCLUSIONS:
Modifications of the adenovirus that lead to receptor targeting resulted in
significantly improved gene transfer efficiencies. These improvements in transfer
efficiencies observed with the modified vectors decreased slightly in the
presence of heparin. However, AdZ.F(pK7) was still superior to AdZ.F(RGD) and
AdZ.F despite heparin administration. These data demonstrate that modifications
of adenoviral vectors that enhance binding to heparan sulfate receptors
significantly improve gene transfer efficiency even in the presence of heparin
and suggest an approach to optimize gene transfer into blood vessels.
PMID- 10668881
TI - Plasma alpha-glutathione S-transferase: a sensitive indicator of hepatocellular
damage during polymicrobial sepsis.
AB - HYPOTHESIS: Since studies have found the liver enzyme alpha-glutathione S
transferase (alphaGST) to be a marker of hepatic injury after hemorrhagic shock,
alphaGST also may serve as a sensitive indicator of hepatocellular damage during
the early stage of polymicrobial sepsis. DESIGN, INTERVENTIONS, AND MAIN OUTCOME
MEASURES: Male adult rats were subjected to the cecal ligation and puncture (CLP)
model of polymicrobial sepsis or sham operation, followed by fluid resuscitation
with isotonic sodium chloride solution. Systemic blood samples were taken at 2,
5, 10, or 20 hours after CLP or sham operation. Plasma levels of alphaGST and
lactate were determined using an enzyme immunoassay and enzymatic assay,
respectively. Additional animals were examined for morphologic alterations in
liver ultrastructure of septic animals using electron microscopy. RESULTS: A
similar level of alphaGST (mean +/- SEM, 30.5 +/- 3.5 microg/L) was found in the
sham group at all measured time points. Although plasma levels of alphaGST did
not change at 2 hours after CLP, they were elevated by 249% at 5 hours after the
onset of sepsis and continued to increase throughout the septic course. Plasma
lactate levels were significantly increased only at 20 hours after CLP (P<.001).
Previous studies have shown that liver transaminase levels did not increase at 5
hours, but at 10 and 20 hours after CLP. In addition, electron microscopy
revealed structural changes in hepatocyte morphology at 5 and 20 hours after CLP
that were indicative of hepatocellular injury. CONCLUSION: Since plasma alphaGST
levels increased earlier than plasma lactate and liver transaminase levels,
alphaGST may be a more sensitive indicator of early liver injury and should be
used in monitoring hepatocellular damage during the progression of sepsis.
PMID- 10668882
TI - A prospective evaluation of recurrent laryngeal nerve paralysis during
thyroidectomy.
AB - HYPOTHESIS: Recurrent laryngeal nerve paralysis after thyroidectomy can be
unrecognized without routine laryngoscopy, and patients have a good potential for
recovery during follow-up. DESIGN: A prospective evaluation of vocal cord
function before and after thyroidectomy. Periodic vocal cord assessment was
performed until recovery of cord function. Persistent cord palsy for longer than
12 months after the operation was regarded as permanent. SETTING: A university
hospital with about 150 thyroid operations performed by 1 surgical team per year.
PATIENTS: From January 1, 1995, to April 30, 1998, 500 consecutive patients (84
males and 416 females) with documented normal cord function at the ipsilateral
side of the thyroidectomy were studied. MAIN OUTCOME MEASURES: Vocal cord
paralysis after thyroidectomy. RESULTS: There were 213 unilateral and 287
bilateral procedures, with 787 nerves at risk of injury. Thirty-three patients
(6.6%) developed postoperative unilateral cord paralysis, and 5 (1.0%) had
recognizable nerve damage during the operations. Complete recovery of vocal cord
function was documented in 26 (93%) of 28 patients. The incidence of temporary
and permanent cord palsy was 5.2% and 1.4% (3.3% and 0.9% of nerves at risk),
respectively. Among factors analyzed, surgery for malignant neoplasm and
recurrent substernal goiter was associated with an increased risk of permanent
nerve palsy. Primary operations for benign goiter were associated with a 5.3% and
0.3% incidence (3.4% and 0.2% of nerves at risk) of transient and permanent nerve
palsy, respectively. CONCLUSIONS: Unrecognized recurrent laryngeal nerve palsy
occurred after thyroidectomy. Thyroid surgery for malignant neoplasms and
recurrent substernal goiter was associated with an increased risk of permanent
recurrent nerve damage. Postoperative vocal cord dysfunction recovered in most
patients without documented nerve damage.
PMID- 10668883
TI - Prevalence and mechanisms of small intestinal obstruction following laparoscopic
abdominal surgery: a retrospective multicenter study. French Association for
Surgical Research.
AB - HYPOTHESIS: The prevalence and mechanisms of intestinal obstruction following
laparoscopic abdominal surgery have not been studied extensively. DESIGN:
Retrospective review of cases of intestinal obstruction after laparoscopic
surgery. SETTING: Sixteen surgical units performing laparoscopy in France.
PATIENTS: Twenty-four patients with intestinal obstruction. MAIN OUTCOME
MEASURES: Prevalence values and descriptive data. RESULTS: The 3 most frequent
primary procedures responsible for intestinal obstruction were cholecystectomy
(10 cases), transperitoneal hernia repair (5 cases), and appendectomy (4 cases).
Prevalences of early postoperative intestinal obstruction after these procedures
were 0.11%, 2.5%, and 0.16%, respectively. Intestinal obstruction was due to
adhesions or fibrotic bands in 12 cases and to intestinal incarceration in 11
cases. Obstruction was located at the trocar site in 13 cases (9 incarcerations
and 4 adhesions), mainly at the umbilicus, and in the operative field in 10 cases
(2 incarcerations in a wall defect after transperitoneal inguinal hernia repair,
4 adhesions, and 4 fibrotic bands). The small intestine was involved in 23 of 24
cases; the other was due to cecal volvulus following unrecognized intestinal
malrotation. Intestinal obstruction was treated by laparoscopic adhesiolysis in 6
patients and by laparotomy in 18 patients, 6 of whom required small intestine
resection. Three postoperative complications but no deaths occurred. CONCLUSION:
Intestinal obstruction following laparoscopic abdominal surgery can occur
irrespective of the type of operation; the prevalence is as high as
(cholecystectomy and appendectomy) or even higher than (transperitoneal hernia
repair) that seen in open procedures.
PMID- 10668884
TI - Detection of isolated disseminated tumor cells in bone marrow and blood samples
of patients with hepatocellular carcinoma.
AB - BACKGROUND: Patients with hepatocellular carcinoma (HCC) often develop
recurrences after curative resection or liver transplantation. Therefore, tumor
cell dissemination must have occurred preoperatively or intraoperatively. Current
staging methods cannot reliably detect micrometastasis. Reverse transcription
polymerase chain reaction (RT-PCR) for alpha-fetoprotein (AFP) has been used to
detect circulating liver cancer cells, but results in blood samples have been
contradictory. HYPOTHESIS: AFP-RT-PCR is a specific and sensitive assay for the
detection of disseminated tumor cells in central venous blood and bone marrow
samples of patients with HCC and has prognostic relevance. DESIGN: Prospective
consecutive series. SETTING: University hospital. PATIENTS AND METHODS: We
performed preoperative, intraoperative, and postoperative analyses of central
venous blood samples and preoperative analysis of bone marrow samples of patients
with HCC and patients without malignant disease, using a modified AFP-RT-PCR
method. Preoperative serum AFP levels were measured. Clinical follow-up ranged
from 4 to 20 months. MAIN OUTCOME MEASURES: Sensitivity and specificity of AFP-RT
PCR, correlation of AFP-RT-PCR results to tumor stage and tumor recurrence.
RESULTS: In serial dilution experiments, 50 AFP-expressing HepG2 cells were
detected in 10 mL of blood. Peripheral blood samples of 20 healthy volunteers and
bone marrow samples of 21 patients with benign diseases consistently tested
negative for AFP, whereas 4 of 24 patients with HCC showed AFP expression in bone
marrow samples. All these patients had advanced disease; however, correlation of
positive RT-PCR results to tumor stage was not significant (P = .07). One of the
4 AFP-positive patients developed an intrahepatic recurrence soon after liver
transplantation. Central venous blood of patients with HCC (n = 24) and patients
with benign liver diseases (n = 13) equally demonstrated AFP-expressing cells.
There was no correlation of RT-PCR results to serum AFP levels. CONCLUSIONS:
Perioperative screening for micrometastasis in bone marrow of patients with HCC
is sensitive and specific with AFP-RT-PCR and may have prognostic relevance.
Alpha-fetoprotein is not a suitable marker for the detection of tumor cells in
central venous blood samples.
PMID- 10668886
TI - Surgery in Mexico.
PMID- 10668885
TI - Maximal human neutrophil priming for superoxide production and elastase release
requires p38 mitogen-activated protein kinase activation.
AB - HYPOTHESIS: Neutrophil priming has been implicated in the development of multiple
organ failure, although the precise intracellular mechanisms that regulate
neutrophil priming remain unclear. Our previous work characterized platelet
activating factor (PAF) priming of human neutrophils for concordant superoxide
anion (O2-) generation and elastase degranulation. The p38 mitogen-activated
protein kinase (MAPK) is activated by PAF stimulation. We hypothesized that PAF
induced human neutrophil priming for O2- and elastase release is mediated via the
p38 MAPK pathway. DESIGN: Isolated neutrophils from 6 human donors were
preincubated with the specific p38 MAPK inhibitor SB 203580 (1 micromol/L) or
buffer (control) for 30 minutes. Cells were then primed with PAF (200 nmol/L),
followed by receptor-dependent (N-formyl-methionyl-leucyl-phenylalanine, 1
micromol/L) or receptor-independent phorbol myristate acetate (PMA, 100 ng/mL)
activation. SETTING: Urban trauma research laboratory. PATIENTS: Healthy
volunteer donors of neutrophils. MAIN OUTCOME MEASURES: Maximal rate of O2-
generation was measured by superoxide dismutase-inhibitable reduction of
cytochrome c and elastase release by the cleavage of N-methoxysuccinyl-Ala-Ala
Pro-Val-p-nitroanilide. RESULTS: SB 203580 significantly attenuated the
generation of O2- and release of elastase from neutrophils activated with N
formyl-methionyl-leucyl-phenylalanine but not with PMA. Independent of the
activator receptor status, SB 203580 almost completely blocked the exaggerated
neutrophil cytotoxic response due to PAF priming. CONCLUSIONS: The p38 MAPK
pathway is required for maximal PAF-induced neutrophil priming for O2- production
and elastase degranulation. Therefore, the MAPK signaling cascade may offer a
potential therapeutic strategy to preempt global neutrophil hyperactivity rather
than attempt to nullify the end products independently.
PMID- 10668887
TI - Robotics and allied technologies in endoscopic surgery.
AB - Endoscopic surgery was developed in the 1970s and 1980s, with initial work
conducted by pioneering surgeons. After the development of laparoscopic
cholecystectomy, the breakthrough of endoscopic surgery had a great effect on all
surgical specialties. Starting with rather simple procedures, such as
cholecystectomy, a rapid progression toward more complex procedures, such as
reflux or colonic surgery, took place. It was realized at this time that the
existing endoscopic instruments allowed only a limited preciseness when
performing the procedures, and part of the information from inside the abdominal
cavity was not available to the surgeon. This prompted a discussion with
engineers concerning the development of more advanced technologies to give those
performing endoscopic surgery the same quality of information and manipulation
that surgeons have when performing open surgery. These qualities include (1)
instruments and manipulators that allow surgical action under endoscopic control
with all degrees of freedom; (2) devices that provide surgeons with tactile
feedback; and (3) vision systems that provide surgeons with the same quality of
visual information as with open surgery, namely, high resolution, excellent color
quality, precise spatial information, and a constant clear view for optimal
surgical action. At the end of 1999, some of the aforementioned quality concepts
found their way into the surgical routine, but most of the concepts are still
being developed. Another decade will pass before endoscopic surgery procedures
will be closer to the technological goals.
PMID- 10668888
TI - Surgical treatment of postoperative incisional hernias by intraperitoneal
insertion of a Dacron mesh and an aponeurotic graft.
PMID- 10668889
TI - A miracle and a privilege.
PMID- 10668890
TI - Internationalization of American surgery.
PMID- 10668891
TI - CD40L is critical for protection from demyelinating disease and development of
spontaneous remyelination in a mouse model of multiple sclerosis.
AB - Theiler's murine encephalomyelitis virus (TMEV) induces acute neuronal disease
followed by chronic demyelination in susceptible strains of mice. In this study
we examined the role of a limited immune defect (deletion or blocking of CD40
ligand [CD40L]) on the extent of brain disease, susceptibility to demyelination,
and the ability of demyelinated mice to spontaneously remyelinate following TMEV
infection. We demonstrated that CD40L-dependent immune responses participate in
pathogenesis in the cerebellum and the spinal cord white matter but protect the
striatum of susceptible SJL/J mice. In mice on a background resistant to TMEV
induced demyelination (C57BL/6), the lack of CD40L resulted in increased striatal
disease and meningeal inflammation. In addition, CD40L was required to maintain
resistance to demyelination and clinical deficits in H-2b mice. CD40L-mediated
interactions were also necessary for development of protective H-2b-restricted
cytotoxic T cell responses directed against the VP2 region of TMEV as well as for
spontaneous remyelination of the spinal cord white matter. The data presented
here demonstrated the critical role of this molecule in both antibody- and cell
mediated protective immune responses in distinct phases of TMEV-mediated
pathology.
PMID- 10668892
TI - Fas/CD95/APO-1 can function as a death receptor for neuronal cells in vitro and
in vivo and is upregulated following cerebral hypoxic-ischemic injury to the
developing rat brain.
AB - Fas/CD95/Apo-1 is a cell surface receptor that transduces apoptotic death signals
following activation and has been implicated in triggering apoptosis in infected
or damaged cells in disease states. Apoptosis is a major mechanism of neuronal
loss following hypoxic-ischemic injury to the developing brain, although the role
of Fas in this process has not been studied in detail. In the present study, we
have investigated the expression and function of Fas in neuronal cells in vitro
and in vivo. Fas was found to be expressed in the 14 day old rat brain, with
strongest expression in the cortex, hippocampus and cerebellum. Cross-linking of
Fas induced neuronal apoptosis both in neuronal PC12 cells in culture and
following intracerebral injection in vivo, indicating that neuronal Fas was
functional as a death receptor. This death was shown to be caspase dependent in
primary neuronal cultures and was blocked by the selective caspase 8 inhibitor
IETD. Finally, cerebral hypoxia-ischemia resulted in a strong lateralised
upregulation of Fas in the hippocampus, that peaked six to twelve hours after the
insult and was greater on the side of injury. These results suggest that Fas may
be involved in neuronal apoptosis following hypoxic-ischemic injury to the
developing brain.
PMID- 10668893
TI - Creutzfeldt-Jakob disease: Carnoy's fixative improves the immunohistochemistry of
the proteinase K-resistant prion protein.
AB - The neuropathological diagnosis of Creutzfeldt-Jakob disease relies on the
immunohistochemical demonstration of the proteinase-K resistant form of the prion
protein (PrPres) in the brain tissue. The antigenicity of PrPres is strongly
reduced by the formalin solution widely used to fix the tissue, thus the PrPres
immunoreactivity is inconsistently detectable in formalin-fixed tissue. A better
PrPres immunostaining can be obtained by using Carnoy's fixing solution, which is
composed of ethanol, chloroform and acetic acid (6:3:1). PrPres can easily be
extracted from Carnoy's-fixed, paraplast-embedded tissue. Accordingly, Carnoy's
fixed tissue can prior to immunolabeling be subjected to proteinase K and
guanidine thiocyanate, which respectively eliminate the normal cellular form of
prion protein and promote protein denaturation. In comparison with the best
protocols for formalin-fixed tissue (i.e.--hydrolytic autoclaving or autoclaving
in distilled water followed by formic acid and guanidine thiocyanate), PrPres
immunostaining carried out on sections cut from Carnoy's-fixed, paraplast
embedded tissue blocks and subjected to proteinase K and guanidine thiocyanate,
proved more successful to detect and map both diffuse and focal PrPres
immunoreactivity, and to correlate the immunoreactivity pattern with MV
polymorphism at PRNP codon 129 and PrPres banding and glycosylation pattern
revealed by Western blot.
PMID- 10668894
TI - Distribution of Borna disease virus in the brain of rats infected with an obesity
inducing virus strain.
AB - Experimental infection of Lewis rats with Borna disease virus (BDV), a
nonsegmented, single-stranded RNA virus, usually causes an immune-mediated
biphasic neurobehavioral disorder. Such animals develop a persistent infection of
the CNS with viral antigen expression in all brain regions and a disseminated
nonpurulent meningoencephalitis. Interestingly, intracerebral infection of Lewis
rats with a BDV-variant (BDV-ob) causes a rapid increase of body weight with the
development of an obesity syndrome without obvious neurological signs. The obese
phenotype is correlated with a characteristic distribution of inflammatory
lesions and BDV-antigen in the rat brain. Infiltration with mononuclear immune
cells and viral antigen expression are restricted to the septum, hippocampus,
amygdala and ventromedian tuberal hypothalamus. Therefore, infection with the
obesity-inducing BDV-ob results most likely in neuroendocrine dysregulations
leading to the development of an obesity syndrome. This might be due to the
restriction of viral antigen expression and inflammatory lesions to brain areas
which are involved in the regulation of body weight and food intake. The BDV
induced obesity syndrome represents a model for the study of immune-mediated
neuroendocrine disorders caused by viral infections of the CNS.
PMID- 10668895
TI - Pineal parenchymal tumors: a correlation of histological features with prognosis
in 66 cases.
AB - The WHO classification of CNS tumors divides pineal parenchymal tumors (PPT) into
pineocytoma (PC), pineoblastoma (PB) and mixed pineocytoma-pineoblastoma or PPT
with intermediate differentiation. The reported incidence of mixed/intermediate
PPT varies and this may reflect the difficulty in classifying tumors of this
type. In an attempt to overcome the problem of the classification of PPT with
intermediate differentiation, we describe the relationship between histological
features and patient survival in a large cooperative series of 66 PPT from 12
neurosurgical centres. All tumors were studied with both light microscopy and
immunohistochemically using antibodies against glial markers or
neural/neuroendocrine markers. Our series included 11 PC, 39 mixed/intermediate
PPT and 16 PB. A number of mitoses greater than 6 and the presence of necrosis
were associated with a poorer outcome, while positive immunostaining for
neurofilaments was associated with a better survival. We propose a new prognostic
grading of 4 grades, grade I for PC, grade II for PPT with fewer than 6 mitoses
and positive immunolabelling for neurofilaments, grade III for PPT with either 6
or more than 6 mitoses or fewer than 6 mitoses but without immunostaining for
neurofilaments and grade IV for PB.
PMID- 10668896
TI - Resuscitative hypothermia protects the neonatal rat brain from hypoxic-ischemic
injury.
AB - The effect of 24 h of hypothermic recovery on moderate hypoxic-ischemic brain
damage in P7-rats was investigated for 42 d after the insult, using magnetic
resonance and histopathology. Occlusion of right common carotid artery and 90 min
exposure to 8% O2 at 37 degrees C body temperature produced cytotoxic edema of
51(+/-11)% brain volume (BV) and depression of brain energy metabolism (PCr/Pi)
from 1.43(+/-0.21) to 0.14(+/-0.11). During recovery, the body temperature was
reduced to 30 degrees C for 24 h in 36 animals, but was kept at 37 degrees C in
34 animals. The edema waned upon reoxygenation leaving only the core lesion at 2
h, but reappeared reaching a maximal extent of 11+/-8% BV under hypothermia
compared to 45(+/-10)% under normothermia at around 24 h. PCr/Pi recovered
transiently within 13 h and declined again to 1.07(+/-0.19) under hypothermia and
to 0.48(+/-0.22) under normothermia at around 24 h. Hypothermia led to
significant long term brain protection, leaving permanent tissue damage of 12(+/
6)% BV compared to 35(+/-12)% BV under normothermia. However, animals with severe
initial injury developed large infarctions, despite hypothermic treatment. Even
then, the time to develop infarction was significantly prolonged, leaving the
opportunity for additional therapeutic intervention.
PMID- 10668897
TI - Characteristic chromosomal imbalances in primary central nervous system lymphomas
of the diffuse large B-cell type.
AB - We performed a genome wide screening for genomic alterations on a series of 19
sporadic primary central nervous system lymphomas (PCNSL) of the diffuse large B
cell type by comparative genomic hybridization (CGH). The tumors were
additionally analyzed for amplification and rearrangement of the BCL2 gene at
18q21 as well as for mutation of the recently cloned BCL10 gene at 1p22. Eighteen
tumors showed genomic imbalances on CGH analysis. On average, 2.1 losses and 4.7
gains were detected per tumor. The chromosome arm most frequently affected by
losses of genomic material was 6q (47%) with a commonly deleted region mapping to
6q21-q22. The most frequent gains involved chromosome arms 12q (63%), 18q and 22q
(37% each), as well as 1q, 9q, 11q, 12p, 16p and 17q (26% each). High-level
amplifications were mapped to 9p23-p24 (1 tumor) and to 18q21-q23 (2 tumors).
However, PCR-based analysis, Southern blot analysis and high-resolution matrix
CGH of the BCL2 gene revealed neither evidence for amplification nor for genetic
rearrangement. Mutational analysis of BCL10 in 16 PCNSL identified four distinct
sequence polymorphisms but no mutation. Taken together, our data do not support a
role of BCL2 rearrangement/amplification and BCL10 mutation in PCNSL but indicate
a number of novel chromosomal regions that likely carry yet unknown tumor
suppressor genes or proto-oncogenes involved in the pathogenesis of these tumors.
PMID- 10668898
TI - Low frequency of SV40, JC and BK polyomavirus sequences in human
medulloblastomas, meningiomas and ependymomas.
AB - Several reports have suggested a role for polyomaviruses in the pathogenesis of
human brain tumors. This potential involvement is not conclusively resolved. For
the present study, a highly sensitive PCR-assay with fluorescence-labelled
primers was developed to search for polyomavirus sequences in human brain tumor
and control DNA samples. The assay was shown to detect approximately one viral
large T-antigen (TAg) gene per 250 cells. We identified simian virus 40 (SV40)
like sequences in 2/116 medulloblastomas, in 1/131 meningiomas, in 1/25
ependymomas and in 1/2 subependymomas. A single case of ependymoma contained SV40
VP-1 late gene sequences. Moreover, one of the meningioma samples showed JC virus
sequences. In contrast, 60 hepatoblastoma samples and 31 brain samples from
schizophrenic patients were consistently negative. BK virus sequences were not
detectable in any of our samples. Immunohistochemical analysis of two SV40
positive tumor biopsies failed to detect large TAg in the tumor cells. In the JC
positive meningioma, immunoreactivity for the viral late gene product (VP-1) was
not observed. Our data do not entirely rule out SV40 and JC virus as an
initiative agent with a hit-and-run mechanism. However the low frequency of virus
sequences and the absence of TAg protein expression argue against a major role of
these viruses in the pathogenesis of human medulloblastomas, meningiomas and
ependymomas.
PMID- 10668899
TI - Introduction: the role of inflammation in mediating damage following stroke and
neurotrauma.
PMID- 10668900
TI - Inflammation and stroke: putative role for cytokines, adhesion molecules and iNOS
in brain response to ischemia.
AB - Ischemic stroke is a leading cause of death and disability in developed
countries. Yet, in spite of substantial research and development efforts, no
specific therapy for stroke is available. Several mechanism for neuroprotection
have been explored including ion channels, excitatory amino acids and oxygen
radicals yet none has culminated in an effective therapeutic effect. The review
article on "inflammation and stroke" summarizes key data in support for the
possibility that inflammatory cells and mediators are important contributing and
confounding factors in ischemic brain injury. In particular, the role of
cytokines, endothelial cells and leukocyte adhesion molecules, nitric oxide and
cyclooxygenase (COX-2) products are discussed. Furthermore, the potential role
for certain cytokines in modulation of brain vulnerability to ischemia is also
reviewed. The data suggest that novel therapeutic strategies may evolve from
detailed research on some specific inflammatory factors that act in spatial and
temporal relationships with traditionally recognized neurotoxic factors. The dual
nature of some mediators in reformatting of brain cells for resistance or
sensitivity to injury demonstrate the delicate balance needed in interventions
based on anti-inflammatory strategies.
PMID- 10668901
TI - Inflammatory mediators of cerebral endothelium: a role in ischemic brain
inflammation.
AB - Brain inflammation has been implicated in the development of brain edema and
secondary brain damage in ischemia and trauma. Adhesion molecules, cytokines and
leukocyte chemoattractants released/presented at the site of blood-brain barrier
(BBB) play an important role in mobilizing peripheral inflammatory cells into the
brain. Cerebral endothelial cells (CEC) are actively engaged in processes of
microvascular stasis and leukocyte infiltration by producing a plethora of pro
inflammatory mediators. When challenged by external stimuli including cytokines
and hypoxia, CEC have been shown to release/express various products of
arachidonic acid cascade with both vasoactive and pro-inflammatory properties,
including prostaglandins, leukotrienes, and platelet-activating factor (PAF).
These metabolites induce platelet and neutrophil activation and adhesion, changes
in local cerebral blood flow and blood rheology, and increases in BBB
permeability. Ischemic CEC have also been shown to express and release bioactive
inflammatory cytokines and chemokines, including IL-1beta, IL-8 and MCP-1. Many
of these mediators and ischemia in vitro and in vivo have been shown to up
regulate the expression of both selectin and Ig-families of adhesion molecules in
CEC and to facilitate leukocyte adhesion and transmigration into the brain.
Collectively, these studies demonstrate a pivotal role of CEC in initiating and
regulating inflammatory responses in cerebral ischemia.
PMID- 10668902
TI - Leukocyte recruitment and the acute inflammatory response.
AB - Leukocyte recruitment is a hallmark feature of the inflammatory response. This
review summarizes the generally accepted paradigm of leukocyte recruitment based
on studies using intravital microscopy to visualize the microcirculation. The
role of selectins and alpha4-integrin in rolling as well as integrin-mediated
adhesion is discussed. However, it is becoming increasingly clear that the
recruitment cascade within organs differs and therefore the review also attempts
to highlight what is and is not known regarding leukocyte recruitment into the
brain microvasculature. In the second part of this review, we provide some
discussion of mechanisms by which the inflammatory response may be terminated.
Particular emphasis on nuclear factor Nf kappaB and how IL10, IL13 and secreted
leukocyte protease inhibitor (SLPI) may impact upon the Nf kappaB-dependent
inflammatory response is presented.
PMID- 10668903
TI - The initiation of the microglial response.
AB - The initial response of microglia to ischemia and ischemia-like conditions was
analyzed in situ and in vitro. After sublethal ischemia in situ, microglia appear
activated morphologically, but do not express macrophage-like antigens. In
contrast, neuronal damage induces full expression of immunomolecules in
microglia. Additionally, blood-borne cells readily infiltrate the region of the
ischemic core and constitute another source of cells with macrophage-like
expression. Thus, it appears that the microglia are the earliest cells to respond
to injury, but their response is graded and complicated by the presence of blood
borne immune cells. In vitro ischemia-like conditions caused an irreversible
depolarization, ion channel shutdown, and blebbing, indicating that microglia are
not equipped to withstand an ischemic insult. Application of ATP alone to
microglia produced outward currents and calcium transients and these calcium
transients increased when ATP was applied in combination with high potassium. It
is known that both outward currents and calcium transients are induced during
spreading depression, a feature of focal injury, and this suggests that spreading
depression might be one of the initial activators of microglia.
PMID- 10668904
TI - Temperature modulation (hypothermic and hyperthermic conditions) and its
influence on histological and behavioral outcomes following cerebral ischemia.
AB - Core temperature (T(C)) is a critical determinant of the severity of neural
damage that results from focal or global ischemia. Former studies indicated that
especially intra-ischemic but also post ischemic mild hypothermia significantly
decreased necrotic neural damage of a focal or global insult, as assessed between
3-7 days post-insult. More recent work shows that prolonged post-ischemic
hypothermia reduces neural damage and inhibits associated behavioral deficits for
up to one year after the insult (i.e. true neuroprotection with behavioral
preservation). Alternatively, increases in core temperature via external heating
or with pyrogens resulting from bacterial infections, at the time of the global
ischemia insult worsen the neural damage of ischemic animals from those of
respective normothermic controls given the same insult. This is paralleled in the
clinical setting whereby approximately 50% of ischemic patients develop fevers
within 2 days of the insult and have worsened neurological outcomes than non
febrile patients. The review discusses the possible mechanisms of neuroprotection
of hypothermic therapy from cerebral ischemia as well as mechanisms involved in
the exacerbation of neural damage of hypoxic ischemia under hyperthermic
conditions. Questions are raised as to whether the medical community has
sufficient evidence to begin appropriate hypothermic therapy of acute stroke
patients. The importance of accurate monitoring core temperatures of all
suspected stroke patients is emphasized, noting the differences in temperature
that can occur with age, sex, medication or lifestyle so that appropriate
temperature treatment could be implemented, if required.
PMID- 10668905
TI - Redox regulation of nuclear factor kappa B: therapeutic potential for attenuating
inflammatory responses.
AB - Nuclear factor kappa B (NF-kappaB) is a protein transcription factor that is
required for maximal transcription of a wide array of pro-inflammatory mediators
that are involved in the pathogenesis of stroke. The purpose of this review
article is to describe what is known about the molecular biology of NF NF-kappaB
and to review current understanding of the interaction between reactive oxygen
species (ROS) in NF-kappaB. ROS seem to play a duel role by participating in the
NF-kappaB activation cascade and by directly modulating DNA binding affinity.
Exogenous and endogenous antioxidants are effective in blocking activation of NF
kappaB and preventing the consequences of pro-inflammatory gene expression. Phase
II enzymes either directly or indirectly play a major in vivo role in minimizing
oxidative stress by scavenging peroxides, peroxide breakdown products and
dicarbonyls and in regeneration of lipid peroxidation chain-breaker, vitamin E.
Dietary phase II enzyme inducers have been demonstrated to increase phase II
enzyme activities in a variety of tissues. These data, together, suggest that
phase II enzyme inducers could have therapeutic value for ameliorating
inflammatory conditions.
PMID- 10668906
TI - July 1999: 66 year old man with a subacute multi-system disorder and
polyneuropathy.
PMID- 10668907
TI - August 1999: 49 year old woman with visual disturbances.
PMID- 10668908
TI - September 1999: 24 year old female with progressive lower extremity dystonia,
dysarthia, dysphagia and mental impairment.
PMID- 10668909
TI - October 1999: 70 year old female with seizures and progressive dementia.
PMID- 10668910
TI - November 1999: 56 year old woman with left facial numbness.
PMID- 10668911
TI - December 1999: 71 year old woman with progressive sensorimotor polyneuropathy.
PMID- 10668912
TI - The role of TNF-alpha in human adipose tissue: prevention of weight gain at the
expense of insulin resistance?
AB - Since evidence has appeared that tumor necrosis factor-alpha (TNF) is involved in
the loss of body fat in the course of wasting diseases, a large number of studies
have investigated the physiological role of this cytokine in adipose tissue. TNF
treatment of several in vitro models of adipogenesis clearly showed that TNF is a
potent inhibitor of adipose differentiation. This antiadipogenic property is
accompanied by suppression of developmental and metabolic markers of fat cell
differentiation, such as peroxisome proliferator-activated receptor (PPAR)
gamma2, lipoprotein lipase (LPL), glycerol-3-phosphate dehydrogenase (GPDH) and
GLUT4. Moreover, TNF promotes lipolysis in mature adipocytes and, subsequently, a
reversion of the adipocyte phenotype. Recent studies demonstrated that TNF
directly interferes with the insulin signaling cascade at early steps and, thus,
impairs insulin-stimulated glucose transport. Further progress in understanding
the role of TNF in adipose tissue was made when endogenous TNF mRNA expression
was demonstrated in adipose tissue. Obesity was found to represent a state of
overexpression of the TNF system. Such findings support the hypothesis that TNF
is a mediator of obesity-linked insulin resistance. However, this concept is
mainly based on animal data and is so far only partially supported by studies in
humans. Taken together, the results of a variety of experimental and clinical
studies suggest that TNF may act as an important auto/paracrine regulator of fat
cell function which serves to limit adipose tissue expansion, probably by
inducing insulin resistance which may in turn cause metabolic disturbances.
Elucidation of the molecular mechanisms of TNF production and action in adipose
tissue may help to find new approaches for the treatment of insulin resistance in
humans.
PMID- 10668913
TI - Stimulation of cardiac glucose transport by thioctic acid and insulin.
AB - Thioctic acid (alpha-lipoic acid) has been shown to improve insulin-regulated
glucose disposal in animal models of insulin resistance and type 2 diabetic
patients. In the present study, we have used isolated adult ventricular
cardiomyocytes in order to analyze 1) direct effects of this compound on glucose
uptake in a primary muscle cell, and 2) the interaction with the insulin
signalling cascade. Both insulin and thioctic acid (2.5 mM) induced a rapid
increase in 3-O-methylglucose transport to 322+/-43 and 385+/-58 (n = 5) percent
of basal control, respectively. Combined stimulation did not result in an
additional significant increase in the transport rate. Preincubation of
cardiomyocytes with the phosphatidylinositol 3-kinase inhibitor wortmannin
completely abolished the effects of insulin and thioctic acid, whereas gamma
linolenic acid selectively blocked the effect of this compound. These data show
that thioctic acid mimics insulin action by activating the signalling cascade at
or before the level of phosphatidylinositol 3-kinase.
PMID- 10668914
TI - Development of low-dose streptozotocin-induced diabetes in ICAM-1-deficient mice.
AB - Multiple injections of low-dose streptozotocin (LDSZ) induce immune-mediated
insulitis and diabetes in C57BL/6 (H-2b) mice. To evaluate the role of the
intercellular adhesion molecule-1 (ICAM-1) for LDSZ induced immune-mediated
diabetes, we have investigated mice genetically deficient in the ICAM-1 gene
(ICAM-1-/-) in comparison to wild-type (ICAM-1+/+) mice. ICAM-1-/- mice, which
had a mixed genetic background of C57BL/6 and DBA/2 mice, were backcrossed to
C57BL/6 mice and screened for H2b homogenicity. Mice received five daily
injections of 40 mg/kg streptozotocin. On day 21 after the first LDSZ injection
55% of the ICAM-1+/+ (female 33%, male 80%) and 50% of the ICAM-1-/- (female 20%,
male 100%), mice had blood glucose levels over 200 mg/dl. Mean blood glucose
levels increased in response to LDSZ treatment, however, no differences between
ICAM-1+/+ and ICAM-1-/- mice were noted. Histological examinations of pancreatic
islets revealed mononuclear infiltration of pancreatic islets without significant
differences between both groups of mice. In summary, LDSZ-induced immune-mediated
insulitis and diabetes development occurs in ICAM-1-/- mice similarly than in
ICAM-1+/+ mice. These results do not support the hypothesis that ICAM-1 plays a
key role during immune-mediated infiltration and destruction of pancreatic islets
in LDSZ induced diabetes.
PMID- 10668915
TI - Potent beta-cell protection in vitro by an isoquinolinone-derived PARP inhibitor.
AB - Activation of the nuclear enzyme poly(ADP-ribose)polymerase (PARP) is a critical
step in beta-cell death in response to exposure with free radicals or other DNA
damaging agents. Nicotinamide, a B vitamin, exerts its beta-cell protective
action primarily via its ability to block excessive PARP activity. We show here
that the isoquinolinone derivative PD128763, a specific PARP inhibitor, provides
protection from cell death in islet cells exposed in vitro to nitric oxide or
oxygen radical generating compounds or to the beta-cell toxin streptozotocin, at
concentrations 100 times less than required for nicotinamide. Furthermore, while
the protective action of nicotinamide is rapidly lost after washing of islet
cells, the effects of PD128763 are more long lasting. Both compounds had little
capacity to rescue damaged islet cells from subsequent lysis. We conclude that
the isoquinolinone derivative PD128763 is superior to nicotinamide in enhancing
the resistance of beta-cells towards inflammatory attacks.
PMID- 10668916
TI - Diabetes mellitus induces long lasting changes in the glucose transporter of rat
heart endothelial cells.
AB - The accumulation of glucose exerts various cytotoxic effects on endothelial and
other vascular cells, and thereby contributes to the development of microvascular
complications in diabetes. Since tissues, in which vascular complications
typically occur, do not take up glucose in an insulin regulated manner, it is an
important question to know whether other mechanisms exist in these cells to
restrict the uptake and the accumulation of glucose. To study this question, we
used microvascular endothelial cells isolated from rat heart endothelial cells
(RHEC). In RHEC, the non-insulin regulated glucose transporter (Glut-1) was
detected as a broad protein band of 50-65 kD. In contrast, the Glut-1 from rat
brain, which was taken as reference, had a molecular weight of 45 kD. After
treatment with endoglycosidase F, both proteins formed a band of approximately 40
kD on SDS-PAGE, demonstrating a more extensive glycosylation of Glut-1 in RHEC as
compared to brain. Incubation of the cells in high glucose (22 mM, up to 10 days)
did not down-regulate either Glut-1 protein or mRNA. In contrast to high glucose,
deprivation of the cells from glucose led to an increase in Glut-1 mRNA and
protein which is partly non-glycosylated. In cells from hearts of streptozotocin
diabetic rats (DRHEC), Glut-1 protein, but not Glut-1 mRNA, was reduced by about
40%. Additionally, a significant amount of glycosyl residues was resistant to the
enzymatic treatment with N-endoglycosidase F. Both changes in Glut-1 were also
observed when the cells were cultivated in low glucose (5.5 mM) for several
passages indicating a long lasting, hardly reversible modification of Glut-1 by
diabetes. These data indicate that Glut-1 is not down-regulated in RHEC by high
glucose, and that this important mechanism to protect the endothelium against an
intracellular accumulation of glucose is missing in RHEC. As a consequence,
increases in blood glucose may lead to a glucose overload with the described
deleterious effects on the structure and function of endothelium.
PMID- 10668917
TI - Effect of 1alpha,25(OH)2-vitamin D3 on TNF alpha-mediated apoptosis of human
primary osteoblast-like cells in vitro.
AB - 1alpha,25(OH)2-vitamin D3 is a hormone which potentially stimulates bone cell
growth and differentiation. TNFalpha is one possible inductor for apoptosis;
apoptosis being an important regulatoring factor for bone modelling and
remodelling. We examined the influence of physiological levels (0.1 nM)
1alpha,25(OH)2-vitamin D3 on TNFalpha-mediated apoptosis in human osteoblast-like
cells. These human cells were obtained from bone fragments obtained during
orthopedic operations on patients without systemic bone disease. Treatment with
1alpha,25(OH)2-vitamin D3 for 8 weeks resulted in a significant reduction (30%)
of viable cell number compared to untreated cells. Incubation with TNFalpha (100
ng/ml for 4 hours) only had limited effects on the rate of apoptosis in control
cells. After pretreatment with 1alpha,25(OH)2-vitamin D3, induction of apoptosis
increased up to 10% in human osteoblast-like cells. In parallel to the induction
of apoptosis, 1alpha,25(OH)2-vitamin D3 stimulated osteocalcin and alkaline
phosphatase as markers of mature osteoblasts. Our data suggest that
1alpha,25(OH)2-vitamin D3 has a stimulatory effect on TNFalpha-induced apoptosis
in human osteoblast-like cells as a result of 1alpha,25(OH)2-vitamin D3-induced
cell differentiation.
PMID- 10668918
TI - High frequency of diabetes-specific autoantibodies in parents of children with
type 1 diabetes. DENIS study group.
AB - Strategies to identify subjects at risk for type 1 diabetes are largely based on
the detection of autoantibodies directed to various beta cell autoantigens. Most
previous studies only comprise siblings and children of patients with type 1
diabetes; only scare data are available on the antibody profile in older
relatives. In this study, we examined the prevalence of cytoplasmic islet cell
antibodies (ICA), antibodies to glutamic acid decarboxylase (GADA), antibodies to
the protein tyrosine phosphatase IA-2 (IA-2A) and IA-2beta (IA-2betaA) in 531
unaffected parents of patients with type 1 diabetes, and compared the results
with antibody frequencies in 2425 siblings. The frequency of ICA, GADA and IA-2A
was substantially higher among siblings as compared to parents of patients with
type 1 diabetes (8.0% vs. 4.5%, 8.0% vs. 4.3%, and 4.5% vs. 1.9%, respectively;
p<0.01). However, subdividing the probands according to age revealed a high
prevalence of ICA (5.5 %), GADA (5.9 %), and IA-2A (3.1%) among parents aged 31
40 years which was similar to that observed in siblings above 20 years of age
(6.4%, 6.4%, and 3.1%). In both cohorts, GADA and IA-2A were significantly
associated with the presence of ICA. The combined screening for GADA and IA-2A
identified 100% of parents and 91.9% of siblings at high risk for type 1 diabetes
(>10 JDF-U). Furthermore, the analysis of antibody combinations revealed that
among antibody positive individuals the percentage of subjects with two or three
antibodies was even higher in parents (69.0%) than in siblings (58.2%). The
present study shows a high frequency of single and multiple autoantibodies in
unaffected parents of patients with type 1 diabetes. Our data indicate that GAD
and IA-2 not only represent the major target of autoantibodies in young siblings
but also in adult relatives. These findings may be important for the design of
future intervention studies.
PMID- 10668919
TI - Dendritic cell immunotherapy induces antitumour response in parathyroid carcinoma
and neuroendocrine pancreas carcinoma.
AB - Parathyroid carcinomas and neuroendocrine carcinomas of the pancreas are rare
malignancies in humans. Because of their low radio- and chemosensibility, they
fail to respond to conventional therapy. We therefore tested a dendritic cell
immunotherapy in an attempt to control the tumour growth in two patients. Studies
on mice and humans have demonstrated the potent capacity of dendritic cells to
induce specific antitumour immunity. Mature dendritic cells were generated from
peripheral blood monocytes in the presence of granulocyte/macrophage colony
stimulating factor, interleukin 4 and tumour necrosis factor alpha. Dendritic
cells were either loaded with parathyroid hormone (PTH) or with (pancreas) tumour
derived lysate (TL), respectively, and were delivered by subcutaneous injections.
All immunizations were well tolerated with no side effects, and were administered
on an outpatient basis. After repeated vaccinations, specific in vivo immune
response was demonstrated by positive delayed-type hypersensitivity (DTH) toward
PTH or TL, demonstrating the efficient generation of antigen-specific memory T
cells. DTH reactivity was accompanied by a significant decrease of tumour markers
in both patients. This approach might be generally applicable to other advanced,
radio- and chemotherapy-resistant endocrine malignancies.
PMID- 10668920
TI - High dose supplementation of RRR-alpha-tocopherol decreases cellular hemostasis
but accelerates plasmatic coagulation in type 2 diabetes mellitus.
AB - BACKGROUND: Diabetes mellitus is associated with increased generation of free
oxygen radicals and depleted scavenging potential (oxidative stress), leading to
increased LDL oxidation and platelet hyperreactivity, the major components of
atherothrombotic vascular lesions. A main goal of antioxidant therapy is to
protect the LDL particle from atherogenic oxidation and to reduce the activated
cellular hemostasis. METHODS: We evaluated the influence of a high dose
supplementation with 800 IU of the natural antioxidant RRR-alpha-tocopherol
(vitamin E) per day for six months on serum levels, vitamin E load of LDL
particles (HPLC), lag phase of LDL oxidation (Esterbauer's assay), platelet
adhesion molecules, leukocyte-platelet coaggregation (flow cytometry, D-III
protocol) and coagulation (INR/PTT) in a group of 36 patients with type 2
diabetes (f/m 22/14; age 58+/-8.0; HbA1 at baseline 10.25+/-1.7). RESULTS:
Average vitamin E levels increased 2.65-fold accompanied by a 1.83-fold increase
of LDL-associated vitamin E and a 12.3 min prolongation of the lag-phase of LDL
oxidation (p<0.001 for all parameters at six months). Platelet expression of
PECAM-1 (CD31) (-30.2% positive cells, p<0.001; antigen density -25%, p<0.001),
ICAM-2 (CD102) (-2.9% positive cells, p<0.01; antigen density -10.6%, p<0.001)
and fibrinogen (-1.6% positive cells, p<0.001; antigen density - 16.1 %, p<0.001)
decreased. Concomitantly, platelet-leukocyte-coaggregation increased by 44%
(p<0.001), correlating to an INR reduction of 10.4% (1.06+/-0.09 to 0.95+/-0.09,
p<0.001, r = - 0.34). The PTT remained constant. CONCLUSION: The antioxidant
protection from the increased vitamin E was accompanied by a decreased expression
of constitutive and function-dependent platelet adhesion molecules. However,
increases in platelet-leukocyte coaggregates and a shortened INR time suggest
extrinsic coagulation activation, possibly by induction of a leukocyte tissue
factor dependent mechanism. High dose supplements of alpha-tocopherol may
override the available redox balance in well controlled type 2 diabetes. However,
intrinsic effects of alpha-tocopherol must be discussed.
PMID- 10668921
TI - Normal ranges and reproducibility of statistical, geometric, frequency domain,
and non-linear measures of 24-hour heart rate variability.
AB - Diabetic cardiovascular autonomic neuropathy (CAN) carries an increased risk of
mortality. The early detection and characterization of CAN has traditionally been
based on the results of autonomic reflex tests (AFTs). A variety of different
measures to quantify 24-hour heart rate variability (HRV) have recently been
introduced, but their normal ranges, reliability, and validity in patients with
CAN have not been adequately studied. We established the normal ranges of
statistical (SDNN index, CV, SNN50, RMSSD), geometric (triangular index (TI),
triangular interpolation (TINN), top angle index [TAI]), frequency domain
(spectral power in the VLF, LF, and HF bands, LF/HF ratio, LF in normalized units
[NU]), and non-linear measures (CV1 and CV2 of the Poincare plot) of 24-hour HRV
in 94 healthy control subjects. Day-to-day reproducibility was evaluated on two
occasions in 17 healthy subjects and 9 diabetic patients. The parameters of HRV
were computed over time periods representing the day (6:00-24:00 hours), night
(00:00-6:00 hours), and 24 hours in total. The results of all indexes, except for
the LF/HF ratio and LF-NU, declined significantly with increasing age (p<0.05),
but were independent of sex and BMI. The statistical, geometric, and non-linear
measures (p<0.05), but not the frequency-domain parameters decreased
significantly with increasing heart rate. Since the HRV data showed log normal
distribution, log transformation was used to define the age-related lower limits
of normal at the 2.5th centile. Intraindividual reproducibility was highest for
the geometric measures. The nonlinear and statistical parameters also showed high
reliability, except for the SNN50. The repeatability of the frequency domain
measures was somewhat lower but still satisfactory. Reproducibility was lower in
the diabetic than in the control group, higher during the day than during the
night, and better than that reported previously for the AFTs. In conclusion, in
healthy subjects the measures of 24-h HRV are not related to sex or BMI, but
strongly dependent on age and heart rate, the latter except for the frequency
domain measures. The majority of the HRV measures, in particular the geometric
parameters, show a relatively high intraindividual reproducibility which
underlines their suitability for the use in prospective studies.
PMID- 10668922
TI - Prevalence of chronic complications, metabolic control and nutritional intake in
type 1 diabetes: comparison between different European regions. EURODIAB
Complications Study group.
AB - This study compares the prevalence of chronic complications, the quality of
metabolic control and the nutritional intake in people with type 1 diabetes in
different European regions. The EURODIAB Complications Study included a sample of
3250 European patients with type 1 diabetes stratified for gender, age and
diabetes duration. All examinations were performed using standardised, validated
methods. HBA1c, LDL-cholesterol and fasting triglycerides were higher in the
eastern European centres than in the southern or north-western European centres.
Acute (severe ketoacidosis, severe hypoglycaemia) and chronic diabetes
complications (retinopathy, nephropathy, neuropathy, cardiovascular disease) were
all considerably more frequent in the eastern European centres. HbA1c was lower
in the German centres than in the total EURODIAB cohort or in the north-western
European centres, but severe hypoglycaemia and proliferative retinopathy were
more common. Persons from the eastern European and the German centres consumed
undesirably high amounts of cholesterol, total and saturated fat. Overall,
improvements in the prevention, detection and management of diabetes
complications in persons with type 1 diabetes are essential throughout Europe,
particularly in eastern European regions. Since elevated LDL-cholesterol levels
and hypertension were strikingly common in this relatively young cohort of
European people with type 1 diabetes, generally more attention should be directed
towards an adequate management of these cardiovascular risk factors.
PMID- 10668923
TI - Detection of autoantibodies to the diabetes-associated antigen IA-2 by a
sensitive enzyme-linked immunosorbent assay.
AB - The tyrosine phosphatase like protein IA-2 is an important autoantigen in insulin
dependent diabetes mellitus (type 1 diabetes). Autoantibodies to IA-2 (IA-2A) are
present in the serum of patients with type 1 diabetes even before the onset of
the disease. Previously, we reported on a radioimmune assay to detect IA-2A,
using E. coli-derived 125I-labelled IA-2 as antigen. Although this assay could be
shown to be equivalent to the common reference method for IA-2A detection
(radioligand assays using in vitro synthesised 35S-methionine labelled antigen),
the disadvantages of both assays with respect to synthesis and handling of the
radioactive antigen limit their use in routine laboratories. In this study, we
have evaluated a non-radioactive enzyme-linked immunosorbent assay (ELISA) for
the simple detection of IA-2A. We report on an ELISA where the biotinylated
intracytoplasmic part of IA-2 (IA-2ic) is captured on streptavidin-coated plates.
The sensitivity of the ELISA was similar to the validated radioligand assay, as
it detected 47 of 69 (69%) patients with type 1 diabetes as compared to 46 of 68
(67 %) with the reference method for IA-2A detection (radioligand assays using in
vitro synthesised 35S-methionine labelled antigen). Only 2 of 50 (4%) patients
with autoimmune thyroid disease and 1 of 114 (1 %) healthy controls were detected
in the ELISA, confirming specificity. There was a significant correlation between
the ELISA and the radioligand assay (r = 0.64, p<0.001). We conclude that this
ELISA is suitable to detect IA-2A in the serum of patients with type 1 diabetes
with a similar sensitivity and specificity to the radioligand assay. This ELISA
will allow rapid and simple measurement of IA-2A where the radioligand assay is
inconvenient or not available.
PMID- 10668924
TI - The malformed kidney: disruption of glomerular and tubular development.
AB - Renal malformations are the major cause of renal failure during early childhood.
They are found in approximately 100 genetic syndromes. We review the embryologic
development of the kidney and its molecular control. Important new information
has been derived from mutational analysis in humans and mice. We describe how
mutations in nine transcription factors, 12 signaling molecules and nine gene
products involved in a variety of other cellular functions disrupt renal
morphogenesis. The information presented provides a template for integrating new
discoveries on the molecular basis of renal development, for classifying renal
malformations observed in the clinical setting, and for identifying defective
genes in affected patients.
PMID- 10668925
TI - Transcervical cells and the prenatal diagnosis of haemoglobin (Hb) mutations.
AB - Prenatal diagnoses of haemoglobin (Hb) mutations were performed using
transcervical cells, retrieved by aspiration from the endocervical canal of ten
selected pregnant women at about 10 weeks of gestation, prior to chorionic villus
sampling (CVS). Both parents were carriers of haemoglobinopathies (thalassaemia
or HbS). Clumps of fetal cells were isolated by micromanipulation under an
inverted microscope and aliquots of the extracted DNA tested separately for the
presence of paternally derived chromosome markers and Hb mutations by
quantitative fluorescent polymerase chain reaction (PCR). The correct prenatal
diagnosis of Hb diseases, using selected single clumps of trophoblastic cellular
elements free of maternal contaminating cells, was achieved in six out of ten
cases.
PMID- 10668926
TI - Mosaicism for a small marker chromosome resulting from a familial Robertsonian
translocation (21;22).
AB - A mosaic marker chromosome found in amniotic fluid was shown to have originated
from the proximal part of the long arm of chromosome 22. This marker is unusual
because it is the result of a deletion of a maternally inherited Robertsonian
21;22 translocation. It is suggested that the deletion and marker formation
probably occurred post zygotically in the fetus. This rare case illustrates the
difficulty in estimating risk of fetal abnormalities associated with de novo
marker chromosomes. In this example, although the 'extra' marker chromosome
contains euchromatin, the karyotype may still be 'balanced'.
PMID- 10668927
TI - Utility of the predictors of coronary heart disease mortality in a longitudinal
study of elderly Finnish men aged 65 to 84 years is dependent on context defined
by Apo E genotype and area of residence.
AB - A common assumption underlying most genetic studies is that individuals with
different genotypes respond similarly to exposure to internal (epigenetic and
background genotype effects) and external (ecological) environments. Here we
evaluate whether this assumption is true in individuals with different genotypes
of the gene coding for the apolipoprotein E (Apo E) molecule, an important
determinant of the metabolic fate of plasma lipids and lipoproteins. We addressed
whether the utility of known risk factors of coronary heart disease (CHD) in the
prediction of CHD death in a 5-year follow-up is the same for the two most common
Apo E genotypes, epsilon3/3 and epsilon4/3, in two cohorts of elderly Finnish men
(age at baseline: 65-84 years), one in Eastern and the other in Southwestern
Finland. The CHD mortality rate was higher in the epsilon4/3 than in the
epsilon3/3 genotype in both cohorts (11.1 versus 7.8%, Pr = 0.281 in the Eastern
cohort and 19.6 versus 8.2%, Pr = 0.002 in the Southwestern cohort). In the
Eastern cohort, serum high density lipoprotein (HDL) cholesterol level was
identified as a strong predictor of CHD death in the epsilon3/3 genotype (beta =
2.155, Pr = 0.019). In the Southwestern cohort, age (beta = 0.139, Pr = 0.006),
body mass index (BMI) (beta = 0.149, Pr = 0.016), and serum total cholesterol
level (beta = 0.453, Pr = 0.051) were identified as strong predictors in the
epsilon3/3 genotype, as were smoking (beta = 0.236, Pr = 0.008) and BMI (beta =
0.124, Pr = 0.057) in the epsilon4/3 genotype. The latter observation indicates
that in Southwestern Finland the probability of CHD death decreases with
increasing BMI in elderly men with the epsilon4/3 genotype, while in their
counterparts with the epsilon3/3 genotype the risk increases with increasing BMI.
This difference was statistically significant (Pr = 0.002). These observations
clearly argue against the assumption that individuals with different genotypes
respond similarly to exposures to internal and/or external environments. These
observations are consistent with a complex pathobiology of CHD involving
biochemical and physiological agents that are under the influence of interactions
between genetic and environmental factors. Information about these interactions
is necessary for developing a more precise risk assessment and ultimately to
improve public health and clinical strategies to prevent this devastating disease
both at the individual and population levels.
PMID- 10668928
TI - Normolipidemia and hypercholesterolemia in persons heterozygous for the same 1592
+ 5G --> A splice site mutation in the low-density lipoprotein receptor gene.
AB - In the present study, we have characterized a unique splice donor G to A
substitution in the moderately conserved + 5 position in intron 10 of the low
density lipoprotein (LDL) receptor gene. In two Danish families, carriers of the
1592 + 5G --> A mutation display a clinical phenotype ranging from healthy
normocholesterolemic persons to classical heterozygous familial
hypercholesterolemia (FH) patients. Reverse transcription-polymerase chain
reaction (RT-PCR) of RNA from Epstein Barr virus (EBV)-transformed lymphoblasts
obtained from members of both families demonstrated abnormal splicing generating
two aberrant mRNAs due to either alternative splicing and skipping of exon 10 or
activation of a cryptic splice site in intron 10 inserting 66 intronic base
pairs. These abnormally spliced mRNAs were predicted to encode two abnormal
receptor proteins containing an in-frame deletion of 75 amino acids and an
insertion of 22 novel amino acids, respectively. Results obtained by
immunofluorescence staining, flow cytometry, and confocal microscopy of
transfected Chang and COS-7 cells expressing normal and mutant LDL receptors were
compatible with nearly complete retention of the mutant proteins in the
endoplasmic reticulum. Quantitative measurements of LDL receptor mRNAs from EBV
transformed lymphoblasts, however, did not reveal any significant differences in
variant mRNA contents between mutation carriers in the families that could be
related to degree of hypercholesterolemia.
PMID- 10668929
TI - Genetic and segregation analysis of congenital cataract in the Indian population.
AB - Congenital cataract is a major cause of blindness in children, and there is wide
variation in the few reports available on the frequencies of its different
inheritance patterns. Two hundred and fifty-two families with congenital cataract
belonging to 13 different states of India, were clinically and genetically
investigated to study their inheritance and segregation patterns. Twenty-one
percent of the cases were autosomal recessive, 15% autosomal dominant, 63% were
simplex cases, and in the remaining cases the inheritance pattern was not clear.
A high incidence of consanguinity (50.9%) was observed in autosomal recessive
cases. Out of 340 affected individuals, 222 (65.3%) were males and 118 (34.7%)
were females. Segregation analysis showed good agreement in autosomal dominant
and recessive families and the data are indicative of the prevalence rate for
different inheritance patterns of congenital cataract within the Indian
population.
PMID- 10668930
TI - Association between polymorphism of the cholecystokinin gene and idiopathic
Parkinson's disease.
AB - Parkinson's disease (PD) is characterized by major alterations of
neurotransmitter activity due to damage of the substantia nigra. Changes in
neuropeptide concentration within the basal ganglia may play an important role in
the putative dopaminergic-peptidergic interactions associated with the disease.
Cholecystokinin (CCK) modulates the release of dopamine in the mesolimbic pathway
and affects dopamine-related behavior. We analyzed genetic variations in the CCK
gene, in both the coding and promoter region, in order to investigate the role of
polymorphism in idiopathic PD. Four polymorphic sites of the CCK gene (-196G/A,
45C/T, 1270C/G, 6662C/T) were found in PD patients and controls. Complete linkage
disequilibrium was observed between the -45 locus and the 1270 locus, and also a
possible linkage disequilibrium was found between the -45 and -196 loci. A
significant difference was found in the distributions of three identified
genotypes at the -45 locus between 116 PD patients and 95 age-matched control
subjects (chi2 = 7.95, p = 0.018, Bonferroni correction; p = 0.054). In addition,
a significant difference was obtained amongst the three genotypic groups at the
45 locus when compared between PD patients who experienced hallucinations (n =
23) and those (n = 93) who did not (chi2 = 8.08, p = 0.018, Bonferroni
correction, p = 0.126). Our data suggested that mutations at the -45 locus in the
promoter region of the CCK gene may influence vulnerability to hallucinations in
PD patients treated with L-dopa.
PMID- 10668931
TI - Polyvariant mutant CFTR genes in patients with chronic pancreatitis.
AB - Several authors have reported an association between mutations of the cystic
fibrosis transmembrane conductance regulator gene (CFTR) and chronic
pancreatitis. CFTR gene transcription and protein efficiency are influenced by
two polymorphic loci, (TG)m and M470V, other than the T5 allele, whose role is
already well-established. The TG11/T5 haplotype is commonly found in healthy
subjects, while the TG12/T5/V470 and TG13/T5/V470 haplotypes are present in
congenital bilateral absence of the vas deferens (CBAVD) patients. While the T5
allele is a mutation that is over-represented in patients with chronic
pancreatitis, no data are available concerning the possible allelic preference at
the other two polymorphic loci, (TG)m and M470V, in these patients. For this
reason, we screened 39 patients with chronic pancreatitis for the most common
CFTR mutations found so far in the Italian population; in addition, we examined
the length of the polypyrimidine (poly-T) tract in intron 8, the (TG)m length and
the M or V codon at position 470. CFTR mutations were found in 3 patients. Poly-T
variant typing identified genotype T5/T7 in 5 patients and T5/T9 in 1 patient.
Direct sequencing of intron 8 in patients with the T5 variant revealed the
TG12/T5/V470//TG11/T7/V470 genotype in 5 patients and TG10/T9//TG11,T5 genotype
in 1 patient. In patients with chronic pancreatitis, the T5 allele is frequently
associated with TG12 and V470, a haplotype already reported in CBAVD cases and
quite uncommon in healthy subjects.
PMID- 10668932
TI - Cerebrotendinous xanthomatosis without xanthomas.
PMID- 10668933
TI - Role of the Pro23Leu mutation in a family affected by retinitis pigmentosa in the
Basque Country.
PMID- 10668934
TI - The incidence of tumours in renal transplant recipients with long-term
immunosuppressive therapy.
AB - INTRODUCTION: The incidence of cancers after renal transplantation is
significantly higher than in population that have not undergone transplantation.
It is increased by a long-term survival of functional graft requiring long-term
immunosuppressive therapy. MATERIAL AND METHODS: Since 1972, 620 renal
transplantations have been performed for different causes of end stage renal
disease. The authors report a group of 18 renal transplant patients (2.9%) who
had cancer. Patients with malignancies are reviewed according to their age, sex,
type of immunosuppression, interval between transplantation and the diagnosis of
cancer, method of treatment and survival. RESULTS: All patients received cadaver
kidneys, and secondary transplantation was performed in two patients. Five
patients received conventional immunosuppression--azathioprine with prednisone,
another 13 patients received cyclosporine with prednisone and/or azathioprine. In
13 males and 5 females (mean age 46.1 years) the malignant disease developed
about 62.4 months after renal transplantation. Six patients had epithelial skin
cancers (four of them had squamous cell carcinomas and two basal cell
carcinomas). Two patients had breast cancer, colorectal carcinoma, renal cell
carcinoma and bladder cancer, respectively, one patient had gastric cancer,
thyroid carcinoma, carcinoma of tonsilla, and monocytic leukaemia with blastic
transformation, respectively. The average survival of patients with malignancies
was 20.3 months. Of 17 patients with cancer, 13 underwent surgical treatment,
four patients with advanced disease received radiotherapy, hormonal treatment or
only symptomatic therapy. In one patient the malignant disease was only
discovered at autopsy. Five patients died of progressive malignant disease, four
of intercurrent disease. Nine (50%) patients are alive, with no evidence of
disease (NED), 31.9 months in average following the diagnosis of malignancy.
Three patients returned to dialysis treatment, other 6 patients live with well
functioning graft. CONCLUSIONS: In patients surviving long time after kidney
transplantation the possibility of development of malignant disease should be
considered. Preventive evaluation should guarantee early detection of cancer.
Appropriate treatment, without cessation of immunosuppressive therapy, is
indicated with the intention to prolong the patients' life with a functional
graft and without dialysis treatment.
PMID- 10668935
TI - Idiopathic retroperitoneal fibrosis revisited.
AB - We have evaluated 21 patients, ranging in age from 44 to 71 years (mean: 55
years), who presented to our department with the radiologic characteristics of
retroperitoneal fibrosis. Ureterolysis was performed in all cases.
Intraperitoneal placement of the ureter was performed in 9, and placement of the
ureter in a lateral extraperitoneal position in 12 cases. We found no difference
in the postoperative course and radiological and clinical improvement to favour
the first or the second method, and therefore we consider the intraperitoneal
approach as an unnecessary manoeuvre.
PMID- 10668936
TI - Glycosaminoglycans excretion in interstitial cystitis.
AB - Glycosaminoglycans (GAGs) have been identified histochemically and biochemically
in urothelium. They have been suggested to have an anti-adherence effect at the
bladder surface important in the urothelial defence against bacterial and
carcinogenic insult. The aim of this study was to investigate urinary GAGs
excretion in patients with interstitial cystitis. Urinary GAG excretion was
determined in patients with interstitial cystitis (n:34; 16 males, 18 females)
and healthy subjects (n:34; 16 males, 18 females). Urinary GAG determinations
were made by the dimethymethylene blue method. Student's t-test was used for
statistical analysis of the results. Urinary GAG excretion was found to be
elevated significantly in patients with interstitial cystitis (14.45+/-2.02 mg/g
Cr) as compared to healthy subjects (10.11+/-2.3 mg/g Cr) (p<0.01). There was no
significant difference in urinary GAG excretion between males and females in
either the healthy subjects or in the patients. Determination of urinary GAG
excretion may be an important non-invasive test in the investigation of patients
with interstitial cystitis.
PMID- 10668937
TI - Prognostic significance of p53 protein accumulation in stage pT1 transitional
cell carcinoma of the bladder.
AB - OBJECTIVE: Mutations in the tumour suppressor gene p53 results in the production
of a mutant type, dysfunctional p53 protein which can readily be detected in the
cell nucleus by immunohistochemical staining. This study aims to investigate the
association of nuclear p53 protein accumulation with the clinical outcome of
stage pT1 transitional cell carcinoma of the bladder which is renowned for high
rates of recurrence and progression. METHODS: TUR samples of the tumours from
fifty-two patients with primary stage T1 bladder cancer were analyzed
immunohistochemically using the standard avidin-biotin peroxidase method for
nuclear p53 accumulation. Status of p53 immunostaining was correlated with tumour
recurrence, disease progression and three-year survival of each patient. RESULTS:
The rate of tumour recurrence in pT1 bladder cancer was 36% in patients with
tumours stained negatively for p53 protein and 78% in patients with tumours
stained positively for p53 protein. Disease progression was seen in 15% of p53 (
) patients and in 56% of p53 (+) patients. CONCLUSIONS: In stage pT1 bladder
tumours p53 nuclear accumulation indicates higher rates of tumour recurrence and
disease progression. Accordingly, in patients who have pT1 bladder tumours with
nuclear p53 accumulation, institution of more aggressive therapy should be
considered and early radical therapeutic modalities should be offered to these
patients.
PMID- 10668938
TI - Tissue polypeptide antigen and carcinoembryonic antigen lack diagnostic accuracy
in urothelial carcinoma.
AB - Carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) levels in
serum and urine from 25 patients with bladder cancer and 42 patients with cancer
of the renal pelvis/ureter have been evaluated as an aid for clinical diagnosis
of urothelial cancer. The tumour CEA content varied markedly, from values
obtained in normal urothelium up to 822 and 7306 ng/g wet tissue in cancer of the
renal pelvis/ureter and bladder cancer, respectively. Serum and urine CEA levels
were found not to correlate with the tumour CEA content. Serum CEA levels were
found increased over 5 microg/L in up to 16% of bladder cancer patients, but only
in 4.8% in renal pelvis/ureter cancer. Urine of cancer patients contained usually
normal CEA levels. Increased serum TPA levels were found in 48% and 35.7% of
patients with bladder cancer and cancer of renal pelvis/ureter, respectively.
Urine TPA levels were significantly increased in both, patients with bladder
cancer (p<0.001) and cancer of renal pelvis/ureter (p<0.01). The median values of
urine TPA were 59, 1095 and 1325 U/L, in controls, patients with bladder cancer
and cancer of renal pelvis/ureter, respectively. However, considering previously
described increase of TPA in inflammatory diseases of urinary tract and in renal
failure patients, results of urinary TPA obtained in the diagnostic workup of
urothelial cancer should be cautiously interpreted. This study shows that serum
and urine levels of CEA and TPA have no diagnostic accuracy required for clinical
diagnosis of urothelial cancer.
PMID- 10668939
TI - The effect of intravesical mitomycin C on the recurrence of superficial (Ta-T1)
bladder cancer. A Hungarian Multicenter Study.
AB - We evaluated the prophylactic efficacy of instillations of intravesical mitomycin
C in 57 patients with primary superficial bladder cancer in a multicenter
clinical trial. After complete transurethral resection of Ta-T1 G1-G2
transitional cell bladder carcinomas, patients were treated with mitomycin 40
mg/50 ml saline of 15 instillations for 12 months. Most of the complications were
mild and transient but two patients dropped out of the trial because of moderate
side effects. Fifty-one patients were evaluable. We observed tumour recurrences
in six patients (11.8%) during a median follow-up of 44.5 months. The recurrences
were treated by transurethral resection. There was no muscle invasive progression
in the recurrences. Our investigations confirm the effectiveness of mitomycin C
in the treatment of patients with superficial bladder cancer.
PMID- 10668940
TI - Squamous metaplasia of the bladder: findings in 14 patients and review of the
literature.
AB - We have documented the data of squamous metaplasia of the bladder in 14 patients
who had undergone cystoscopies for different reasons. In two biopsies, there were
marked keratinization and cellular atypia. One of these two subjects was
diagnosed as squamous carcinoma of the prostate and transitional cell carcinoma
of the bladder. The lesions of 8 female patients were on the trigone and
evaluated as normal anatomical variants due to hormonal changes. Three of them
were remarkable because of recurrent urinary infections. Apart from the two male
patients with squamous cell carcinoma of the prostate the two male patients with
current squamous metaplasia have been following up. In this study, we have also
reviewed the relationship between squamous metaplasia, infection and malignancy.
PMID- 10668941
TI - Augmentation ureterocystoplasty with ipsilateral renal preservation in the
management of patients with compromised renal function secondary to dysfunctional
voiding.
AB - We evaluated the role of ureterocystoplasty with ipsilateral renal preservation
in the management of patients with neurovesical dysfunction and impaired renal
function. The procedure was carried out on 6 patients with a mean age of 8.5
years. All patients had vesicoureteric reflux (VUR) secondary to neuropathic
bladders, recurrent urinary tract infections, day time incontinence, impaired and
deteriorating renal function. All patients were followed up with a mean of 22.5
months (range 6-30). Renal function stabilized in 4 patients and improved in 2
patients. Adequate urinary bladder capacity was achieved in all patients. Bladder
volume increased from a mean of 210+/-71 to 382+/-66, this increase was
statistically significant (p<0.001). All patients were dry by day including the
children who at presentation were in diapers. We conclude that the results of
this operative intervention are satisfactory and promising in the management of
this difficult group of patients while avoiding the side effects of
enterocystoplasty procedures.
PMID- 10668942
TI - Effects of doxazosin in men with benign prostatic hyperplasia: urodynamic
assessment.
AB - OBJECTIVE: In this study, a randomized and placebo controlled trial, we aimed to
study the effectiveness and safety of doxazosin based upon urodynamic parameters,
especially pressure/flow studies, in men with benign prostatic hyperplasia (BPH).
MATERIALS AND METHODS: A total of 57 men (29 doxazosin, 28 placebo) 48-82 years
of age with BPH were enrolled. Yet, 8 of 29 in the doxazosin group and 10 of 28
in the placebo group were excluded due to side effects of doxazosin and
intolerability of urodynamic assessment of free uroflow, postvoiding residual
urine volume (PVR) and pressure/flow studies. RESULTS: There were improvements in
all urodynamic parameters (Free Qmax: 30.4% and 28%, PVR: 14 ml and 12 ml,
invasive Qmax: 29.3% and 26.2%, Pdet at Qmax: -32.7% and -30%, Pdet-max: -29% and
-27.7% at end of the 1st and 6th months whereas placebo effects were worsening in
all urodynamic parameters. CONCLUSIONS: We suggest that doxazosin is an important
treatment option for patients with BPH, and efficacy of doxazosin should be
evaluated with objective, quantitative urodynamic studies not with subjective
symptom scores. But additional costs and invasiveness of urodynamic studies
restrict their common usefulness.
PMID- 10668943
TI - The value of serum prostate specific antigen and other parameters in detecting
bone metastases in prostate cancer.
AB - The cut-off value of serum prostate-specific antigen (PSA) level in prediction of
bone metastases and the correlation of serum PSA with the clinical stage, grade,
score and the rate of bone metastases have been investigated in cases of prostate
cancer (PCa). The study population consisted of 160 patients with histologically
proven PCa between April, 1993 and August, 1996. The negative predictive value
and the sensitivity were the highest (94%) in patients with a serum PSA value
less than 10 ng/ml. We claim that in patients with PSA values less than 10 ng/ml
whole body bone scan is not necessary.
PMID- 10668944
TI - Antibiotic prophylaxis for transrectal biopsy of the prostate: a prospective
randomized study of the prophylactic use of single dose oral fluoroquinolone
versus trimethoprim-sulfamethoxazole.
AB - We investigated the efficacy of prophylactic use of single dose oral ofloxacin
and trimethoprim-sulfamethoxazole regimens for transrectal prostate biopsy in 110
men. In the ofloxacin, trimethoprim-sulfamethoxazole and control groups, urinary
infection was found in 2 (4.76%), 3 (6.66%) and 6 (26.08%) patients,
respectively. Both of these antibiotic regimens produced a statistically
significant reduction in urinary infection (p<0.02, p<0.05). Our study indicates
that single dose fluoroquinolone or trimethoprim-sulfamethoxazole prophylaxis
seems to be effective, practical and economical.
PMID- 10668945
TI - Prospective evaluation of prostate specific antigen (PSA), PSA density, free-to
total PSA ratio and a new formula (prostate malignancy index) for detecting
prostate cancer and preventing negative biopsies in patients with normal rectal
examinations and intermediate PSA levels.
AB - OBJECTIVE: To improve the specificity and sensitivity of prostatic cancer
detection, we prospectively evaluated total prostate specific antigen (PSA)
level, PSA density, free-to-total PSA ratio and a new formula called prostate
malignancy index (PMI) as a discriminator of prostate cancer in patients with
intermediate PSA levels and normal digital rectal examinations. MATERIALS AND
METHODS: Between November 1995 and October 1997, 95 patients who had serum PSA
levels of 4.0 to 10.0 ng/ml with normal digital rectal examinations were
prospectively evaluated. All patients underwent one or two times transrectal
ultrasound guided prostate biopsies. Based on age specific reference range of
PSA, PSA density and % free PSA ratio, PMI was calculated for each patient. The
free and total serum PSA concentrations were determined by an Immulite assay
system. (Diagnostic Product Corp., Los Angeles, California). RESULTS: Overall 20
of 95 (21%) patients had prostate cancer. There were no significant differences
in patient mean age and mean total PSA between those with benign and those with
malignant biopsies (p>0.05). However, there were significant differences in mean
PSAD, mean free-to-total PSA ratio and mean PMI (p<0.01, p<0.05, p<0.01,
respectively). Benign condition specificities for PM index, percent free PSA, PSA
density and total PSA at a 90% sensitivity for prostate cancer were 48%, 10.6%,
8% and 4%, respectively. Of 95 patients, 27 (28.4%) had a PMI of equal or more
than 3.1, including 12 of 75 (16%) with negative biopsy and 15 of 20 (75%) with
positive biopsy. Furthermore a cutoff MI 0.86 P correctly identified 24% of
benign cases without missing any prostate cancer cases. The comparison of
receiver operating characteristic (ROC) curve areas showed that PMI was better
than total PSA (p<0.01). Although, the area under the ROC curve of % free PSA and
PSAD were higher than the area of total PSA, these differences were not
statistically significant (p>0.05). CONCLUSIONS: We concluded that the prostate
malignancy index could be utilized to differentiate benign conditions from
prostate cancer in patients with intermediate PSA levels and normal digital
rectal examination. Also significant numbers of negative biopsies can be
prevented in these patients.
PMID- 10668946
TI - Sequential scrotal scintigraphy for the study of varicocele.
AB - Scrotal scintigraphy is a non-invasive procedure for evaluating spermatic vein
reflux. This technique was used in 43 infertile patients with varicocele. None of
them had infections, traumatic, or chromosomal abnormalities that could be
associated with their infertility. Twelve patients showed type 1 time activity
curve, including 3 with grade II, and 9 with grade III varicocele. A total of 12
patients showed a type 2 pattern and consisted of 2 patients with grade I, 6 with
grade II, and 4 with grade III varicocele. Nineteen showed type 3 pattern
consisting of 6 with grade I, 6 with grade II, and 7 with grade III. The patients
with grade III varicocele showed type 1 pattern more frequently than those with
grade I or II (p<0.05). Preoperative sperm concentration in patients with grade I
varicocele was significantly lower than that in patients with grade II or III
disease (p<0.05, each). Sperm motility of patients with grade I varicocele was
also significantly lower than that of those with grade II or III varicocele
(p<0.01, each). Patients with grade II or III varicocele showed an increase in
sperm concentration postoperatively, and those with grade I varicocele showed a
postoperative increase in sperm motility, but the differences between pre- and
postoperative values were not significant. While seminal findings in patients
with type 2 or 3 pattern did not change after surgery, patients with type 1
pattern showed significant improvement in sperm concentration postoperatively
(p<0.05). It is concluded that preoperative sequential scrotal scintigraphy can
be a more useful technique for assessing the prognosis for postoperative
improvement of seminal findings than the grade decision of varicocele.
PMID- 10668947
TI - Significance of serum FSH levels and testicular morphology in infertile males.
AB - OBJECTIVES: To determine the relationship between plasma levels of FSH and
testicular spermatogenic patterns. METHODS: Testicular biopsies were obtained
from 99 infertile men. Biopsies were performed either in order to distinguish the
type of azoospermia (obstructive/non-obstructive) or because of severely
subnormal semen variables. Serum FSH was measured by immunoassay (normal range is
less than 7 mIU/ml). RESULTS: Statistically significant difference was detected
between patients with Sertoli cell only syndrome and normal spermatogenesis,
hypospermatogenesis and maturation arrest (p<0.01, p<0.01, p<0.05, respectively).
No statistically significant differences were found between normal
spermatogenesis, hypospermatogenesis and maturation arrest. CONCLUSION: Our study
revealed that elevation of serum FSH correlates only with the appearance of
Sertoli cell only syndrome. We think that azoospermic or severely
oligoasthenoteratozoospermic patients with highly elevated plasma FSH levels
(three times the normal) could be excluded from separate testicular biopsy,
because these patients are not suitable for conventional treatments. If he is
willing to undergo an IVF program the sperm will often be present, no matter what
the testicular histology is to be used for assisted reproductive techniques,
particularly ICSI.
PMID- 10668948
TI - The treatment of penile carcinoma: experience in 64 cases.
AB - INTRODUCTION: Carcinoma of the penis is an uncommon entity in Poland (160 new
cases per year). PURPOSE: To review our results in treatment of penile cancer in
64 patients. MATERIAL AND METHODS: From 1989 to 1998, 64 patients were treated
for carcinoma of the penis. The age of the patients varied from 21 to 86.
Clinical and pathological categories were assessed according to TNM
classification. Inguinal lymphadenectomy was performed in 35 patients. Following
surgery 12 patients underwent radiotherapy, 3 chemotherapy, 3 radiotherapy and
chemotherapy. RESULTS: Twenty-two percent of patients died of cancer with median
survival of 49 weeks. Bilateral inguinal involvement after node dissection was
found in 17 patients. Unilateral inguinal involvement was found in 7 patients.
Six patients had positive pelvic nodes. Of patients with initially non metastatic
disease (N0) 8.3% showed progression to death, of patients with initially lymph
node metastases (N+) 46% showed progression to death. The 5-year disease-free
survival rates of patients with N+ and N0 were 40% and 82%, respectively. Of the
patients 11% had local recurrence. Postoperative complications developed in 30
cases. CONCLUSIONS: The likelihood of lymph node invasion at presentation was
related to T category and grade of primary tumour. The most important prognostic
factor for patients with carcinoma of the penis was lymph node involvement.
PMID- 10668949
TI - Continuous ambulatory peritoneal dialysis (CAPD) adequacy influences serum free
carnitine level.
AB - OBJECTIVE: An evaluation of serum free carnitine level in CAPD patients in
relation to dietary intake, nutritional status and CAPD adequacy and duration.
STUDY DESIGN: Food diaries, nutritional (total body mass, lean body mass, serum
level of proteins, carnitine, cholesterol) and adequacy (Kt/V, PCR, tCcr, EN)
parameters were obtained in 23 CAPD patients. RESULTS: Normal carnitine level
(41.8+/-6.7 micromol/l) was found in 17 patients being on CAPD through 11.1+/-9.6
months, whereas in 6 persons treated with CAPD through 9.7+/-4.1 months carnitine
level was 25.4+/-5.7 micromol/l. Significant differences between low and normal
carnitine groups were in tCcr (82.7+/-16.7 v. 65.9+/-13.2 l/wk/1.73 m2 BSA),
effluent volume (10.9+/-0.8 v. 9.9+/-1.5 l/day), effluent glucose concentration
(729+/-167 v. 530+/-220 mg/dl) and serum globulin level (22.6+/-6.4 v. 29.3+/-4.4
g/l). Significant correlation coefficients (for n = 23) were found between serum
carnitine level and effluent volume (r=-0.509) or plasma globulin level
(r=+0.522). CONCLUSION: Patients with higher CAPD adequacy show lower serum free
carnitine levels and this is related to higher effluent volumes.
PMID- 10668950
TI - Protein Z levels in haemodialysis patients.
AB - Protein Z (PZ) is a vitamin K-dependent protein isolated from human and bovine
plasmas. Although the exact role of PZ in the haemostatic system is presently
unknown, it is suggested that PZ deficiency may cause bleeding tendency.
Haemostatic alterations in end-stage renal failure (ESRF) are certainly complex
and involve several abnormalities in the coagulation and fibrinolytic system. In
order to elucidate the detail of the haemostasis in ESRF, we aimed to investigate
PZ activity in haemodialysis patients. Therefore, we compared plasma PZ levels in
10 haemodialysis patients (6 M, 4 F, mean age 36+/-11) and 10 healthy normal
controls (5 M, 5 F, mean age 34+/-8) in this study. We found mean plasma PZ
levels in haemodialysis patients and healthy controls 6.95+/-2.93 microg/ml and
3.06+/-0.81 microg/ml, respectively (p<0.005). Increased level of PZ which
influences the action of thrombin on its protein substrates and inhibitors may
contribute to the haemostatis alterations in ESRF patients, in addition to other
well known abnormalities in the coagulation and fibrinolytic system.
PMID- 10668951
TI - The importance of bioimpedance (BIA) analysis and Cardio Tens (24-h ABPM and ECG)
monitoring in the dialysis programme.
AB - The authors performed bioimpedance analysis and Cardio Tens (24-h ABPM and ECG)
monitoring in 66 patients (28 males, 38 females) treated in the chronic
haemodialysis programme. They investigated the correlations between the body
weights before, during and after dialysis, the changes of the water compartments
and fat body weight, and the recorded values of blood pressure and ECG
alterations. On the basis of the measurements by this non-invasive method it is
concluded that, as a result of dialysis and ultrafiltration, the total body
weight and total body water are decreasing in a greater extent in men than in
women. By gradually decreasing the body weight, the optimal dry weight could be
attained, which resulted in the reduction of blood pressure or even normotension.
In the course of dialysis the values of bioimpedance and bioreactance increase.
The intradialytic hypotensive indispositions were accompanied by a significant
reduction of bioreactance (n = 16). The BMI, total body weight and total body
water hyperlipidaemic, hypalbuminic patients with treatment-resistant
hypertension are considerably larger than those of the patients with normal blood
pressure (p<0.01). During Cardio Tens monitoring 53% of the patients proved to be
dippers, 47% of whom had ST depression, while in 73% of the non-dippers ischaemic
alterations were encountered together with high hyperbaric impact values. The
total body weights and total water compartments of patients returning to dialysis
with an excess body weight of more than 3.5 kg were significantly larger than of
patients who were cooperative and had no oedemas. In the last hour of dialysis
and during the following few hours, arrhythmias and ST depressions of the
cardiovascularly instable patients appeared more frequently. The total water
compartments of these patients are significantly larger than normotensive,
normolipaemic patients with appropriate serum albumin concentrations. The
importance of the BIA and Cardio Tens monitoring in determining the optimal dry
body weight and improving the cardiovascular condition of the patients is
emphasized.
PMID- 10668952
TI - Tubulointerstitial lesions in IgA nephropathy and localization of hepatocyte
growth factor.
AB - To investigate the relationship between localization of hepatocyte growth factor
(HGF) and tubulointerstitial lesions (TILs) in the cortical area of renal biopsy
specimens, a clinicopathological study was performed in 55 patients with IgA
nephropathy. HGF was detected by an enzyme-antibody method and TILs were assessed
semiquantitatively by light microscopy. HGF was observed mainly on epithelial
cells in the tubules, but not in the glomeruli. Fourteen patients had biopsies
that were positive for HGF. There was a correlation between HGF positivity and
histological damage, the TIL grade, and several clinical parameters determined at
biopsy. Thus, HGF is related to TILs in IgA nephropathy and may be a factor in
the exacerbation of this disease.
PMID- 10668953
TI - Relationship between some prognostic markers of HD patients and serum
erythropoietin, insulin-like growth factor-1, leptin, parathormone and
testosterone.
AB - Iseki et al. [1] have shown that serum levels of albumin (Alb), creatinine (Cr)
and BMI are significant predictors of death in haemodialyzed patients (HD pts).
In our study we decided to assess the relationship between the levels of Alb, Cr,
BMI and substances which have a known metabolic effect on nutritional status in
HD pts: endogenous erythropoietin (Epo), insulin-like growth factor-1 (IGF-1),
leptin (Lep), parathormone (PTH), and testosterone. The study was conducted in 53
(28M, 25F) stable HD pts. Serum levels of endogenous Epo and PTH were estimated
by CLIA; IGF-1, Lep, testosterone, sex hormone binding globulin were estimated by
RIA. The multiple regression analysis was done between Alb, Cr, BMI and Epo, IGF
1, PTH and Lep for all HD pts together and free androgen index (FAI) for men and
women separately. Correlations: the level of serum albumin did not correlate
significantly with any of the measured substances. Serum creatinine level
significantly correlated only with the level of IGF-1 (p=0.02), BMI was
significantly correlated with serum endogenous Epo (p<0.01), leptin (p=0.004) and
FAI (p<0.005) both in men and women. We concluded that the higher concentrations
of endogenous Epo, IGF-1 and testosterone could be correlated with a better
prognosis in HD patients.
PMID- 10668954
TI - Tuberculosis in chronic renal failure in Jeddah.
AB - The incidence of tuberculosis is still high in many developing countries and
immunocompromised patients with chronic renal failure requiring haemodialysis
have been reported to be at increased risk of developing tuberculosis. In this
study 80 patients with chronic renal failure were followed up for a period of
three years and were carefully monitored for the development of tuberculosis.
Mantoux test, chest radiograph and sputum were performed at the beginning of the
study and every six months thereafter. At the end of the study period, 8 (10%) of
the patients had developed tuberculosis, confirming the high incidence of
tuberculosis in this group of patients. No particular underlying renal disease
was associated with the development of tuberculosis. Four patients developed
pulmonary tuberculosis, 2 renal tuberculosis and one each with cervical
tuberculous lymphadenitis and tuberculous meningitis. All patients responded
satisfactorily to anti-tuberculosis therapy as diagnosis was established early.
The delayed recognition of tuberculosis and therefore a delay in the initiation
of effective treatment is not only detrimental to the patient but also results in
a potentially profound impact on public health. We recommend routine screening
for tuberculosis in patients with chronic renal failure presenting at Renal Units
and tuberculosis chemoprophylaxis for those undergoing haemodialysis,
particularly in countries with high incidence of tuberculosis.
PMID- 10668955
TI - Third single chromosome 6 workshop: meeting report.
PMID- 10668956
TI - The chromosome 6 sequencing project at the Sanger Centre.
AB - Chromosome 6 is probably best known for encoding the major histocompatibility
complex (MHC) which is essential to the human immune response. In addition, it
has been shown to be associated with many diseases such Schizophrenia, Diabetes,
Arthritis, Haemochromatosis, Narcolepsy, Epilepsy, Retinitis Pigmentosa,
Deafness, Ovarian Cancer, and many more. Chromosome 6 is about 180 Mb in size and
is estimated to encode around 3500 genes of which only about 10% are currently
known. It is our aim to map, sequence and annotate the entire chromosome in close
collaboration with the chromosome 6 community.
PMID- 10668957
TI - Retroelements and segmental duplications in the generation of diversity within
the MHC.
PMID- 10668958
TI - A linkage map of chromosome 6 based on 2 large kindreds segregating bipolar
affective disorder.
AB - Twenty-eight markers, both simple sequence repeats (SSRs) and restriction
fragment length polymorphisms (RFLPs), were genotyped on members of 2 large
pedigrees (OOA, BIP167) segregating bipolar affective disorder. Using the
multipoint program "build" of CRIMAP and odds of placement 1000:1, a unique sex
averaged map was generated that spans 227 cM and includes 26 markers. The two
other markers were placed on the map with a lower likelihood. The female
recombination map is larger than the male recombination map by about 80%. Linkage
analysis between the polymorphisms and the disease in the OOA screening pedigree
did not result in any significantly positive lod scores nor did a non-parametric,
identity-by-descent, method generate any significant p-values. BIP167 was
analyzed for allele sharing at the simple sequence repeat loci and significant
associations were not found. At present we conclude, that the pedigrees under
study do not have a major predisposition gene for bipolar affective disorder on
chromosome 6 under the diagnostic and transmission models analyzed by the 2
different methods.
PMID- 10668959
TI - Isolation and characterisation of cosmids to intervals within a 4.5Mb region at
6p21.3.
AB - The gene responsible for hereditary haemochromatosis (HH) has recently been
identified. One mutation in this gene, termed HFE, has been found in all
Australian HH patients. We previously identified a predominant HH ancestral
haplotype covering 4.5Mb at 6p21.3, and showed that patients with two copies of
this haplotype express a more severe form of the disorder. One key question to
now be resolved is why haplotype related variation in phenotypic expression of HH
is present if all patients tested have the same HFE mutation. A cosmid resource
covering the 4.5Mb HH ancestral haplo type region was obtained. These cosmids
provide the material for the completion of a transcript map of this region, and
will assist the identification of candidate modifiers of HFE expression.
PMID- 10668961
TI - Alternative splicing of the LST-1 gene located in the Major Histocompatibility
Complex on human chromosome 6.
PMID- 10668960
TI - From long range mapping to sequence-ready contigs on human chromosome 6.
AB - Our aim is to construct physical clone maps covering those regions of chromosome
6 that are not currently extensively mapped, and use these to determine the DNA
sequence of the whole chromosome. The strategy we are following involves
establishing a high density framework map of the order of 15 markers per Megabase
using radiation hybrid (RH) mapping. The markers are then used to identify large
insert genomic bacterial clones covering the chromosome, which are assembled into
sequence-ready contigs by restriction enzyme fingerprinting and sequence tagged
site (STS) content analysis. Contig gap closure is performed by walking
experiments using STSs developed from the end sequences of the clone inserts.
PMID- 10668962
TI - Complex duplications at 6p22.1, 6p11.2, 5q13, 5p15.1 and 5p13 revealed by
fluorescent in situ hybridisation.
AB - A complex pattern of fluorescent in situ hybridisation (FISH) has been detected
using PAC clones from the short arm of chromosome 6, proximal to the
haemochromatosis gene at 6p22.1. Cross-hybridisation to 6p22.1, 6p11.2, 5q13,
5p15.1 and 5p13 was consistently detected with several PAC clones covering a
genomic region greater than 200 kb. These results indicate that large sections of
genomic DNA are shared by these 5 disparate chromosomal segments, indicative of
large scale duplication events. These results were in part accounted for by the
identification of several expressed sequence tags (ESTs).
PMID- 10668964
TI - Physical mapping of two histone gene clusters on human chromosome 6p22.1-22.2.
AB - Histones are basic proteins which are responsible for the assembly and
maintenance of the nucleosomal structure within the chromosomal fiber in
eukaryotes. Two clusters of these genes have previously been mapped to the region
6p21.1-p22.2. We describe here a radiation hybrid map, a long range restriction
map and a YAC contig covering and linking these two clusters and giving the
precise localisation with respect to the HLA complex. The large cluster contains
five H1 histone genes in the 6p22.2 region, the smaller only one, H1F5 (H1.5), in
6p22.1. In both clusters, each H1 locus is accompanied by several core histone
genes. The large cluster has additionally been covered by a sequence ready PAC
contig and three probably unrelated genes (TRMI2, BTN and SSADH) have been
accurately localized within the 6p22.2-p22.1 region.
PMID- 10668963
TI - The Chromosome 6 database at the Sanger Centre.
AB - The Sanger Centre Chromosome 6 Database (6ace) has been developed as the primary
means of release of annotated sequencing and mapping information for human
chromosome 6 from the Sanger Centre. It is also being used to curate global data
from published and unpublished external sources. The rationale behind the
development of 6ace is described, together with information as to how to access
the database.
PMID- 10668965
TI - Dissection of the 5.5 Mbp region directly telomeric of HLA-B including a long
range restriction map, YAC and PAC contigs.
AB - A large number of diseases are associated with the human major histocompatibility
(HLA) complex located in 6p21.3. The underlying defect of most of these has not
yet been determined even after detailed analysis of the HLA region. Due to the
extended haplotypes found in this area, several of the HLA-linked disease genes
may be located also telomeric of the class I region. In order to analyse the area
covering the 4 megabases directly telomeric of HLA-F in close detail, we have
generated 50 new markers. These and other markers have been used to establish a
SalI restriction map from 46 YACs. A subset of 42 markers was applied to
construct a genomic long range restriction map from an HLA-A2/B13 haplotype. Both
maps have been compared revealing the presence of additional 150 kb in the HLA-A2
haplotype close to the RFP locus. Additionally, 47 PACs have been selected
mapping to this region and grouped into 7 contigs. Sequencing of these PAC
contigs has already been initiated.
PMID- 10668966
TI - Biology of chromosome 6.
AB - The major histocompatibility (HLA) complex on the short arm of human chromosome 6
has attracted many scientists over the last three decades. It is the purpose of
this brief review to point out that the remaining large regions of chromosome 6
contain genes involved in several interesting biological phenomena as well. Focus
will be particularly on genes affecting behavioural features and sensory
perception. The likely involvement of HLA and closely linked olfactory receptor
loci in mate selection and their possible role in favouring heterozygosity among
the offspring will also be discussed.
PMID- 10668967
TI - A brief history of the Hubrecht Laboratory.
PMID- 10668968
TI - A treasure house of comparative embryology.
AB - The Embryo Collection of the Hubrecht Laboratory is a treasure house of
comparative embryology. It is the largest and most important collection of its
kind in the world, and consists of thousands of vertebrate embryos stored in
alcohol, or prepared as histological sections. Many elusive species are included
in the collection, some represented by complete developmental series. The
accompanying archives offer a remarkable insight into the methods used to collect
embryos form wild animals, as well as the motives behind the founders of the
collection. Carefully maintained, documented and catalogued, the collection is
available for study by all interested scientists. We argue that this collection
is one of the greatest biodiversity resources in existence.
PMID- 10668969
TI - A nose for the embryo: the work of Pieter Nieuwkoop.
PMID- 10668970
TI - Pieter Nieuwkoop's contributions to the understanding of meso-endoderm induction
and neural induction in chordate development.
AB - Pieter Nieuwkoop, who died September 18, 1996, at age 79 in Utrecht, The
Netherlands, is remembered by developmental biologists for his numerous research
contributions and integrative hypotheses over the past 50 years, especially in
the areas of neural induction, meso-endoderm induction, and germ cell induction
in chordates. Most of his experimentation was done on the embryos of amphibia,
the preferred vertebrate embryo of the early years of the 20th century. One of
his last publications contains a comparison of the experimental advantages and
disadvantages of anuran and urodele amphibians (Nieuwkoop, 1996). The
significance of his findings and interpretations for developmental biology can be
estimated from the fact that researchers of many laboratories worldwide continue
to work on the phenomena he first described and to extend the hypotheses he first
formulated. The aim of this article is to review Nieuwkoop's main contributions
and to cite the recent extensions by others.
PMID- 10668971
TI - The neural induction process; its morphogenetic aspects.
AB - This posthumous review of early embryonic inductions concludes: 1) the amphibian
egg has only two distinct components, animal and vegetal. Interactions at their
mutual boundary forms meso-endoderm. This is "meso-endoderm induction", not just
"mesoderm induction". 2) The dorso-ventral polarity of the yolk mass implies a
dorsally situated inducing centre. 3) Accumulation of cells into one, two, three
or many cell masses [problastopores] along the circumference of the meso-endoderm
results in as many axes, implying a self-organizing capacity of meso-endoderm. 4)
Induction of the meso-endoderm is slow, spreading cell to cell through the animal
moiety from the boundary of the vegetal yolk mass towards the animal pole. 5)
Interaction between mesoderm and ectoderm is a separate step leading to cranio
caudal differentiation of the archenteron roof. 6) The initial invaginating
endoderm and mesoderm, representing the future pharynx endoderm and prechordal
plate mesoderm, first contacts the most posterior presumptive neurectoderm after
having passed the still uninvaginated trunk mesoderm. At that moment an antero
posterior level neural induction actually starts. 7) The ectoderm contraction
wave coincides spatially and temporally with the induced neural plate. 8) Two
successive homoiogenetic waves of inductive activity pass through the presumptive
neurectoderm in the anterior direction, the first one, "activation", giving rise
to neural differentiation and ultimately forebrain, the second one,
"transformation", to more caudal CNS structures. These are separate, successive
steps in CNS regional induction. 9) The midbrain represents a secondary formation
in the neural plate. 10) The observed changes in morphogenesis may depend upon
separate, successive binary decisions via [cell and] nuclear state splitters
[involving differentiation waves].
PMID- 10668972
TI - Discovery of a morphogen.
PMID- 10668973
TI - A visit to the Hubrecht laboratory.
PMID- 10668974
TI - Initiation, establishment and maintenance of Hox gene expression patterns in the
mouse.
AB - Spatially and temporally restricted expression of the Hox genes along the main
and appendicular axes is essential for correct patterning of vertebrate embryos.
In this overview we discuss the latest data that shed light on the mechanisms
underlying the generation of the expression domains of the Hox genes. The
molecular genetic interactions governing initial transcription of the Hox genes
in the posterior part of the primitive streak during mouse and chick gastrulation
remain enigmatic. But the recent discovery by Kondo and Duboule (Cell, 97, 1999,
407-417) of a "cluster repressive regulation", will undoubtedly lead to a better
understanding of the molecular genetic mechanism underlying colinear and
sequential initiation of Hox gene transcription. Recently progress has been
booked in characterizing the basal processes driving progression of the Hox
expression domains during their establishment. Hox expression is still labile
while being established. The transcriptional state of Hox genes in anterior
tissues can be reprogrammed under the influence of more posterior locations.
Posteriorizing activity may involve RA and FGF signaling. It is only when these
interactions and, in some cases at least, regulatory interactions with Hox and
cdx gene products occur appropriately, that the Hox expression domains would be
correctly established. After the Hox expression domains have been established,
regulatory processes involving the products of Polycomb and trithorax- Group
genes start operating, perpetuating the transcriptional state of the Hox genes
within and outside the expression domains. Whether control at the level of
chromatin structure, believed to operate during the late maintenance phase of Hox
gene expression, is also involved in regulating concerted initial expression of
these genes, is a possibility that has been suggested.
PMID- 10668975
TI - Vertebrate aristaless-related genes.
AB - Aristaless-related genes, a subset of the Paired-related homeobox genes, have in
the past few years emerged as a group of regulators of essential events during
vertebrate embryogenesis. One group of aristaless-related genes has been linked
to the morphogenesis of the craniofacial and appendicular skeleton by their
expression patterns and by the phenotypes of natural and artificial mouse
mutants. Expression and function in the nervous system characterise a second
group, and a third group, the Pitx genes, have been shown to have many different
roles, including functions in the pituitary, left-right determination and limb
development.
PMID- 10668976
TI - Novel interactions between vertebrate Hox genes.
AB - Understanding why metazoan Hox/HOM-C genes are expressed in spatiotemporal
sequences showing colinearity with their genomic sequence is a central challenge
in developmental biology. Here, we studied the consequences of ectopically
expressing Hox genes to investigate whether Hox-Hox interactions might help to
order gene expression during very early vertebrate embryogenesis. Our study
revealed conserved autoregulatory loops for the Hox4 and Hox7 paralogue groups,
detected following ectopic expression Hoxb-4 or HOXD4, and Hoxa-7, respectively.
We also detected specific induction of 5' posterior Hox genes; Hoxb-5 to Hoxb-9,
following ectopic expression of Hoxb-4/HOXD4; Hoxb-8 and Hoxb-9 following ectopic
expression of Hoxa-7. Additionally, we observed specific repression of 3'
anterior genes, following ectopic expression of Hox4 and Hox7 paralogues. We
found that induction of Hoxb-4 and Hoxb-5 by Hoxb-4 can be direct, whereas
induction of Hoxb-7 is indirect, suggesting the possibility of an activating
cascade. Finally, we found that activation of Hoxb-4 itself and of posterior Hox
genes by Hoxb-4 can be both non-cell-autonomous, as well as direct. We believe
that our findings could be important for understanding how a highly ordered Hox
expression sequence is set up in the early vertebrate embryo.
PMID- 10668977
TI - A tight control over Wnt action.
AB - Here, we review the WNT pathway and its regulation at different levels. We focus
on the transcriptional regulation of WNT target genes, in light of the recently
identified negative regulators, i.e. relatives of groucho and CBP.
PMID- 10668978
TI - Growth factor signalling.
AB - Signalling between cells in the developing vertebrate embryo is essential for
normal embryonic development. In the mid 1970's, signal transduction research
started at the Hubrecht Laboratory with special emphasis on analysis of the
signalling mechanisms that direct cell proliferation and differentiation. The
introduction of in vitro model systems contributed tremendously to the success of
the signal transduction research at the Hubrecht Laboratory. Initially
neuroblastoma cell lines, and later embryonal carcinoma and embryonal stem cells
played an important role in identification of the molecular key players in
developmental signalling. For instance, embryonal carcinoma cells were used to
identify and characterise polypeptide growth factors. Growth factor signalling
research was extended to analysis of growth factor receptor activation. Moreover,
the second messenger systems that are linked to growth factor receptors were
studied, as well as the nuclear responses to growth factor receptor activation.
Finally, the role of growth factor signalling in differentiation was established
using embryonal carcinoma cells. Here, we will review work that was
characteristic for the growth factor receptor signalling research that was done
at the Hubrecht Laboratory between 1980 and the early 1990's.
PMID- 10668979
TI - Developmental tumours, early differentiation and the transforming growth factor
beta superfamily.
AB - Embryonal carcinoma and embryonic stem cells have been very useful models for
identifying some of the factors that regulate differentiation in early mammalian
development. Here, we present a brief history of their original isolation and
characterization and of their later introduction into the Hubrecht Laboratory. We
illustrate in a review their contribution to our current understanding of the
function of transforming growth factor beta and ligands binding to the receptors
of a related factor, activin, in development with some of our own work.
PMID- 10668980
TI - Signals governing extraembryonic endoderm formation in the mouse: involvement of
the type 1 parathyroid hormone-related peptide (PTHrP) receptor, p21Ras and cell
adhesion molecules.
AB - The formation of parietal endoderm (PE) from primitive endoderm (PrE) immediately
after implantation of the early mouse embryo can be seen as the earliest example
of an epithelio-mesenchyme transition (EMT) in murine development. Since EMT and
EMI (epithelium-mesenchyme interactions) are at the very heart of morphogenesis,
identifying molecular mechanisms governing these processes is of utmost
importance. An excellent in vitro model system to study PE formation, i.e. F9
embryonal carcinoma cells, is available to this end. In the present paper we
review our own recent results and those of others using these cells, and present
our current view on the molecular mechanisms involved in PE formation.
PMID- 10668981
TI - Receptor protein-tyrosine phosphatase signalling in development.
AB - Receptor Protein-Tyrosine Phosphatases (RPTPs) belong to the superfamily of
protein-tyrosine phosphatases and have the intrinsic ability to transduce signals
across the cell membrane. We are beginning to understand the role of RPTPs in
development of invertebrates, due to elegant genetic studies. In contrast,
relatively little is known about the role of RPTPs in vertebrate development.
Signalling by RPTPs has predominantly been studied in mammalian cell systems,
which has led to important insights into potential ligands, into regulation of
RPTP activity and into potential RPTP substrates. Here, we will introduce the
RPTPs, and discuss the function of the LAR-subfamily of RPTPs. In addition, we
focus on the function and signalling of the haematopoietic RPTP, CD45. Finally,
we will discuss the structure and function of RPTPalpha, the RPTP that is the
subject of our studies.
PMID- 10668982
TI - Morphogenetic action of retinoids and estrogens.
AB - Retinoids and estrogens are small lipophilic compounds fulfilling important
biological roles in vertebrate development, reproduction and homeostasis. Both
types of ligands are regulators of gene transcription by binding to (nuclear)
proteins acting as ligand-activatable transcription factors, members of the
nuclear receptor gene superfamily. Retinoids and their multiple receptors
(RARs/RXRs) are particularly well-known for their role in early development and
spermatogenesis, while much less is known about the two estrogen receptors
(ERalpha/beta) during development. In this article we describe some of our
previous and present work in both areas of research.
PMID- 10668983
TI - Germ line development in fishes.
AB - Classical work on germ cells in fishes has dealt with three main issues; their
embryonic origin, the proliferation, and migration pathway during embryonic and
larval development. Until recently, primordial germ cells (PGCs) have been
studied in a number of fishes using morphological criteria only. The
identification of the Drosophila vasa homolog gene of zebrafish now allows
comparison of these morphological data with vasa RNA expression patterns in
zebrafish. Teleost PGCs can be distinguished from somatic cells by their distinct
morphology, at the earliest during gastrulation, and in most fishes their number
varies between 10 and 30 during pregonial development. Mitosis is generally not
observed in PGCs at extragonadal locations, whereas they are mitotically active
once at the gonadal ridges. During gastrulation, PGCs appear to translocate from
the epiblast to the hypoblast and during somitogenesis they are found associated
with the most peripheral yolk syncitial layer (YSL). From the peripheral YSL they
migrate through the median mesoderm into the dorsal mesoderm and then to the
dorsal mesentery, where they establish the gonad primordia with mesenchymal
cells. Vasa RNA positive cells, the PGCs of the zebrafish conform to these
general observations. Interestingly, classical descriptive and experimental data
can now be reevaluated using vasa as a molecular marker of the fish germ line.
The power of zebrafish genetics together with possibilities of experimental
embryology should accelerate research on aspects of vertebrate germ line
development such as PGC migration, division and apoptosis, as well as (in)
fertility. The present review summarizes some of the classical data on germ line
development in fishes in relation to recent data on vasa expression in zebrafish
and compares these findings, where appropriate, with those in other model
organisms. Special emphasis is placed on vasa gene expression as a potential
universal germ line marker and suggestions are made for novel, zebrafish specific
approaches to investigate the vertebrate germ line.
PMID- 10668984
TI - Developmental bioinformatics: linking genetic data to virtual embryos.
AB - This paper discusses current efforts to produce databases of gene expression for
the major model embryos used in developmental biology. The efforts to build these
resources were motivated by the need for immediate internet access to all types
of research data, and the production of these databases is a major and new
challenge for bioinformatics. Thus far bioinformatics has mainly been concerned
with textually oriented resources and data, much of it concerned with gene and
protein sequences. Because the genetic basis of developmental biology is
integrated with developmental anatomy, these databases require the use of images
to link molecular data with spatial information. In order to standardise database
formats, digital atlases of some model systems are being produced that include
integrated anatomical descriptions and these are being linked to appropriate
genetic data. Integrating such image-based, searchable data into databases makes
new demands on the field of bioinformatics and we consider here the imaging
modalities that are used to obtain information and we discuss in particular the
production of 3D images from serial sections. Next, we consider how to integrate
textual and spatial descriptions of gene expression and the key tool needed to
make this possible, i.e. anatomical nomenclature. A short review of internet
resources on developmental biology is also given and future prospects for the
development of these databases are discussed.
PMID- 10668985
TI - Fate mapping the mouse embryo.
AB - The use of clonal analysis to obtain a fate map of the epiblast of the mouse
embryo and to investigate cell distribution during gastrulation and early
neurulation is described in a personal reminiscence. A revised fate map of the
epiblast at 6.5 days gestation is provided, and the development of 3-dimensional,
quantitative image analysis techniques outlined.
PMID- 10668986
TI - Comparative and correlative neuroanatomy for the toxicologic pathologist.
AB - Xenobiotic-induced neuroanatomic alterations are always regarded as adverse and
are commonly used to define reference doses to manage neurotoxic risk. Thus, the
neuropathologist plays an essential role in evaluating potential neurotoxicants.
The pathologist must be able to recognize the morphologic differences that exist
among species, strains, and ages or between genders (comparative neuroanatomy)
and to grasp the impact of structural damage on neural function (correlative
neuroanatomy). Brain anatomy and function may be used to group the mammals used
in neurotoxicity bioassays into 3 classes: rodent, carnivore, and primate. Neural
function may or may not be affected by the structural divergence. Rodents are
preferred for neurotoxicity assays because their reduced body size allows optimal
perfusion at little cost and their smaller brain size permits screening of
multiple regions using few sections. However, care must be exercised when
interpreting rodent neuropathology data because the rodent paleocortex does not
recapitulate the sophisticated neocortical circuitry and functions of carnivores
and primates. Knowledge of the neuroanatomic variations that exist among test
species assists the neuropathologist in defining the relevance of structural
alterations, the potential clinical sequelae of such findings, and the possible
significance of similar changes in humans.
PMID- 10668987
TI - Microglial response to brain injury: a brief synopsis.
AB - In addition to astrocytes and oligodendrocytes, microglia represent the third
major population of glial cells within the central nervous system (CNS).
Microglia are distributed ubiquitously throughout the brain and spinal cord, and
one of their main functions is to monitor and sustain neuronal health. Microglial
cells are quite sensitive to even minor disturbances in CNS homeostasis, and they
become readily activated during most neuropathologic conditions, including
peripheral nerve injury, trauma and stroke, inflammatory disease, and
neurotoxicant-induced neuronal injury. During activation, microglia display
conspicuous functional plasticity, which involves changes in cell morphology,
cell number, cell surface receptor expression, and production of growth factors
and cytokines. The many changes occurring in activated cells reflect the altered
functional states of microglia that are induced by signals arising from injured
neurons. Thus, neuronal-microglial signaling plays a fundamental role in
understanding how the CNS responds to injury. Reactive microgliosis should be
viewed as a cellular effort to initiate ameliorative and reparative measures in
the injured brain.
PMID- 10668988
TI - Synaptic clefts are made to be crossed: neurotransmitter signaling in the central
nervous system.
AB - The primary means of communication between neurons in the mammalian central
nervous system (CNS) is via release of chemical transmitters. Although the first
transmitters to be discovered were the biogenic amines, such as acetylcholine and
norepinephrine, involved in transmission in the autonomic nervous system, the
contribution of other types of transmitters, such as amino acids and peptides, to
CNS transmission has been the subject of recent study. Part of this interest
stems from the relatively large percentage of neuronal connections that make use
of amino acid transmitters such as gamma-aminobutyric acid and glutamate and also
from the tremendous diversity possible when peptides are used as transmitters.
Several disorders of CNS transmission are related to the degeneration of neuronal
pathways in the brain. Two of the most prevalent neurologic disorders that result
from degeneration are Alzheimer's and Parkinson's diseases. Aspects of these
disorders related to chemical neurotransmission are discussed, along with
implications with regard to therapeutic strategies. Functions of and possible
abnormalities in amino acid transmission that may be associated with CNS
disorders are examined. Several peptides are postulated to play a role in
neurotransmission and concepts regarding the significance of the coexistence and
release of biogenic amines and peptides at the same neuronal terminals are
presented.
PMID- 10668989
TI - An integrative approach to neurotoxicology.
AB - Exposure of human populations to a wide variety of chemicals has generated
concern about the potential neurotoxicity of new and existing chemicals.
Experimental studies conducted in laboratory animals remain critical to the study
of neurotoxicity. An integrative approach using pharmacokinetic,
neuropathological, neurochemical, electrophysiological, and behavioral methods is
needed to determine whether a chemical is neurotoxic. There are a number of
factors that can affect the outcome of a neurotoxicity study, including the
choice of animal species, dose and dosage regimen, route of administration, and
the intrinsic sensitivity of the nervous system to the test chemical. The
neurotoxicity of a chemical can vary at different stages of brain development and
maturity. Evidence of neurotoxicity may be highly subjective and species specific
and can be complicated by the presence of systemic disease. The aim of this paper
is to give an overview of these and other factors involved in the assessment of
the neurotoxic potential for chemicals. This article discusses the neurotoxicity
of several neurotoxicants (eg, acrylamide, trimethyltin, 1-methyl-4-phenyl
1,2,3,6-tetrahydropyridine, manganese, and ivermectin), thereby highlighting a
multidisciplinary approach to the assessment of chemically induced neurotoxicity
in animals. These model chemicals produce a broad range of effects that includes
peripheral axonopathy, selective neuronal damage within the nervous system, and
impaired neuronal-glial metabolism.
PMID- 10668990
TI - Mechanisms of injury in the central nervous system.
AB - Neurotoxicants with similar structural features or common mechanisms of chemical
action frequently produce widely divergent neuropathologic outcomes.
Methylmercury (MeHg) produces marked cerebellar dysmorphogenesis during critical
periods of development. The pathologic picture is characterized by complete
architectural disruption of neuronal elements within the cerebellum. MeHg binds
strongly to protein and soluble sulphydryl groups. Binding to microtubular -SH
groups results in catastrophic depolymerization of immature tyrosinated
microtubules. However, more mature acetylated microtubules are resistant to MeHg
induced depolymerization. In contrast to MeHg, the structurally similar organotin
trimethyltin (TMT) elicits specific apoptotic destruction of pyramidal neurons in
the CA3 region of the hippocampus and in other limbic structures. Expression of
the phylogenetically conserved protein stannin is required for development of TMT
induced lesions. Inhibition of expression using antisense oligonucleotides
against stannin protects neurons from the effects of TMT, suggesting that this
protein is required for expression of neurotoxicity. However, expression of
stannin alone is insufficient for induction of apoptotic pathways in neuronal
populations. The aromatic nitrocompound 1,3-dinitrobenzene (DNB) has 2
independent nitro groups that can redox cycle in the presence of molecular
oxygen. Despite its ability to deplete neural glutathione stores, DNB produces
edematous gliovascular lesions in the brain stem of rats. Glial cells are
susceptible despite high concentrations of reduced glutathione compared with
neuronal somata in the central nervous system (CNS). The severity of lesions
produced by DNB is modulated by the activity of neurons in the affected pathways.
The inherent discrepancy between susceptibility of neuronal and glial cell
populations is likely mediated by differential control of the mitochondrial
permeability transition in astrocytes and neurons. Lessons learned in the
mechanistic investigation of neurotoxicants suggest caution in the evaluation and
interpretation of structure-activity relationships, eg, TMT, MeHg, and DNB all
induce oxidative stress, whereas TMT and triethyltin produce neuronal damage and
myelin edema, respectively. The precise CNS molecular targets of cell-specific
lipophilic neurotoxicants remain to be determined.
PMID- 10668991
TI - Mechanisms of toxic injury in the peripheral nervous system: neuropathologic
considerations.
AB - The anatomical distribution and organization of the peripheral nervous system as
well as its frequent ability to reflect neurotoxic injury make it useful for the
study of nerve fiber and ganglionic lesions. Contemporary neuropathologic
techniques provide sections with excellent light-microscopic resolution for use
in making such assessments. The histopathologist examining such peripheral nerve
samples may see several patterns of neurotoxic injury. Most common are
axonopathies, conditions in which axonal alterations are noted; these
axonopathies often progress toward the Wallerian-like degeneration of affected
fibers. These are usually more severe in distal regions of the neurite, and they
affect both peripheral and central fibers. Examples of such distal axonopathies
are organophosphorous ester-induced delayed neuropathy, hexacarbon neuropathy,
and p-bromophenylacetylurea intoxication. These axonopathies may have varying
pathologic features and sometimes have incompletely understood toxic mechanisms.
In such neuropathies with fiber degeneration, peripheral nerve axons may
regenerate, which can complicate pathologic interpretation of neurotoxicity. On
occasion neurotoxins elicit more severe injury in proximal regions of the fiber
(not included in this review). Axonal pathology is also a feature of the
neuronopathies, toxic states in which the primary injuries are found in neuronal
cell bodies. This is exemplified by pyridoxine neurotoxicity, where there is
sublethal or lethal damage to larger cytons in the sensory ganglia, with failure
of such neurons to maintain their axons. Lastly, one may encounter
myelinopathies, conditions in which the toxic effect is on the myelin-forming
cell or sheath. An example of this is tellurium intoxication, where demyelination
noted in young animals is coincident with toxin-induced interference of
cholesterol synthesis by Schwann cells. In this paper, the above-noted examples
of toxic neuropathy are discussed, with emphasis on mechanistic and morphologic
considerations.
PMID- 10668992
TI - Application of silver degeneration stains for neurotoxicity testing.
AB - Silver staining procedures have been used in numerous ways to render a variety of
physical and biological features visible. In biological tissue, histologic
protocols use silver to visualize diverse structures or features, such as
reticulin, melanin, fungi, chromosome bands, nucleolar organizing regions, and
different features in the nervous system. A comparison of the specific steps in
these protocols indicates that the silver is "directed" to stain any given
feature by the type of fixation, the pretreatment ("mordanting"), the composition
of the silver-containing solution(s), and the form of development (reduction).
Since the mechanisms of staining have not been understood historically (nor are
they now), each method was developed by trial and error. Keystone methods such as
those of Bodian and Bielschowsky exploit the nervous system's affinity for silver
(argyrophilia). The beginning of a new era in brain research came with the
recognition that distinct silver-impregnated morphologic changes occurring in
damaged axons could be used for tracing axon pathways in experimental animals
with specifically placed lesions. Improvements in staining methods used to
selectively impregnate the disintegrating axons but to leave normal axons
unstained were achieved by Nauta and Gygax (early workers with these procedures)
and spawned a host of method variations known as the "Nauta" methods. Of these,
the Fink-Heimer and de Olmos cupric-silver methods were able to unambiguously
demonstrate disintegrating synaptic terminals, thereby allowing complete tracing
of axon pathways. The late 1970s and 1980s witnessed innovative applications of
these techniques. The silver methods once used to trace axon pathways became
indicators of the extreme endpoint of neurotoxicity: disintegrative degeneration
of neurons induced by neurotoxic chemicals that were administered systemically.
The hallmark of neurotoxic substances is the selectivity with which each destroys
specific populations or subpopulations of neurons. The high contrast and
sensitivity of the silver degeneration stains greatly facilitate the screening
process to detect these affected populations, especially when there is no basis
for knowing where in the brain to look for damage. More recently, in addition to
expanded use in screening for neurotoxic effects, the silver degeneration stains
are being used to chart the neuron populations undergoing programmed cell death
in the developing brain. Other newly developed silver methods have been refined
to show nondisintegrative degeneration, such as the plaques,and tangles of
Alzheimer's disease.
PMID- 10668993
TI - MK-801 neurotoxicity in cupric silver-stained sections: lesion reconstruction by
3-dimensional computer image analysis.
AB - Routine histopathologic evaluation of the brain (paraffin embedding, hematoxylin
and eosin staining) makes it difficult for an investigator to identify the
overall location and relative extent of lesions as they relate to neural
substructures. Moreover, it is very difficult to convey this information to
others who are less familiar with neuroanatomy. This study combined a 3
dimensional imaging program with a cupric silver stain for neuronal degeneration
in order to determine the location and extent of a focal lesion produced by MK
801 (dizocilpine maleate), a glutamate receptor antagonist that induces necrosis
in a small population of neurons in the cortex of rats. A male Sprague-Dawley rat
was treated with a subcutaneous dose of MK-801 (10 mg/kg) and was perfused with
fixative through the left ventricle 3 days after treatment, a time point known to
reveal maximal neurotoxic effects. The brain was embedded in a gelatin matrix,
frozen, and serially sectioned at a thickness of 40 microm. The cupric silver
method of de Olmos was used to stain frozen sections at 320-microm intervals.
Using a color charged-couple device (CCD) camera and a macro lens, a series of 2
dimensional images, which encompassed the entire rostral to caudal extent of the
brain, was captured. A computer program was written to define internal and
external boundaries in these 2-dimensional images. Then, 3-dimensional
reconstructions were generated on a Silicon Graphics workstation using IRIS
"Explorer." The quality of the 3-dimensional reconstructions allowed for easy
identification of various neural substructures while clearly revealing the exact
location and extent of the resulting necrotic neurons that were positively
identified by the cupric silver stain. This 3-dimensional lesion reconstruction
method provides a powerful tool for conveying spatial information about the
nature of neurotoxic lesions in the brain. In addition, it may be used to
investigate further dose-response relationships and the effects of other
neurotoxicants.
PMID- 10668994
TI - Fluoro-Jade: novel fluorochromes for detecting toxicant-induced neuronal
degeneration.
AB - Two anionic fluorescein derivatives can be used for the simple and definitive
localization of neuronal degeneration in brain tissue sections. Initial work on
the first generation fluorochrome, Fluoro-Jade, demonstrated the utility of this
compound for the detection of neuronal degeneration induced by a variety of well
characterized neurotoxicants, including kainic acid, 3-nitropropionic acid,
isoniazid, ibogaine, domoic acid, and dizocilpine maleate (MK-801). After
validation, the tracer was used to reveal previously unreported sites of neuronal
degeneration associated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP),
methamphetamine, and d-fenfluramine. Preliminary findings with a second
generation fluorescein derivative, Fluoro-Jade B, suggest that this tracer
results in staining of optimal contrast and resolution in animals dosed with
kainic acid. These 2 tracers can be combined with other histologic methods,
including immunofluoresence and fluorescent Nissl stains. Recent preliminary
findings on a number of specialized applications of Fluoro-Jade include the
detection of apoptosis, amyloid plaques, astrocytes, and dead cells in tissue
culture.
PMID- 10668995
TI - Virtual neuropathology: three-dimensional visualization of lesions due to toxic
insult.
AB - A first-pass approach incorporating high-field magnetic resonance imaging (MRI)
was used for rapid detection of neuropathologic lesions in fixed rat brains. This
inherently 3-dimensional and nondestructive technique provides high-resolution,
high-contrast images of fixed neuronal tissue in the absence of sectioning or
staining. This technique, magnetic resonance microscopy (MRM), was used to
identify diverse lesions in 2 well-established rat neurotoxicity models. The
intrinsic contrast in the images delineated lesions that were identified using a
battery of histologic stains, some of which would not be used in routine
screening. Furthermore, the MRM images provided the locations of lesions, which
were verified upon subsequent sectioning and staining of the same samples. The
inherent contrast generated by water properties is exploited in MRM by choosing
suitable pulse sequences, or proton stains. This approach provides the potential
for a comprehensive initial MRM screen for neurotoxicity in preclinical models
with the capability for extrapolation to clinical analyses using classical MRI.
PMID- 10668996
TI - Stress proteins as molecular markers of neurotoxicity.
AB - In response to many environmental and pathophysiologic stressful stimuli, cells
undergo a stress response characterized by induction of a variety of proteins,
including the heat shock protein family. The inducible heat shock protein 70
(hsp70) is believed to participate in an array of cellular activities, including
cytoprotection. Normal brain cells have little detectable hsp70 RNA or protein.
However, following a stressful condition hsp70 mRNA and protein are induced in
different cell types depending on the severity and the nature of the stimulus.
The induction of hsp70 protein correlates with the regional and cellular
vulnerability to a particular injury as identified by standard histologic
methods. The pattern of hsp70 expression differs in response to various
neurotoxic stimuli, including hyperthermia, ischemia, seizures, hemorrhage, and N
methyl-D-aspartate receptor antagonist administration. Hsp70 expression is a
useful marker of cellular injury and may help to identify previously unrecognized
areas of vulnerability in the nervous system after a neurotoxic stimulus. Hsp70
may also play a neuroprotective role in the brain.
PMID- 10668997
TI - Teased-fiber technique for peripheral myelinated nerves: methodology and
interpretation.
AB - Teased-fiber technique is the best approach for studying peripheral myelinated
nerve fibers in their continuity. It enables the assessment of size of myelin
segments formed by Schwann cells and characterization of pathologic changes
affecting the internodia, the paranodal regions, and the invested axons. Fiber
teasing is performed on prestained proximodistally oriented portions of
peripheral nerves. Specimens about 10 mm long are stained for 24-48 hours in
Sudan black and then transferred to glycerin, where, using a pair of fine forceps
and a stereomicroscope, they are separated into smaller fiber bundles from which
single fibers are isolated. The work is performed on a glass slide with an
adhesive surface (albuminized or "superfrost"), on which the fibers are placed in
strict proximodistal orientation. Following drying in an oven, the slides are
mounted with glycerin-gelatine (same as used for frozen sections). The changes,
when present, can usually be recognized during the preparation, but fibers are
reexamined and changes confirmed in mounted slides. Photographic reconstruction
of the fibers facilitates their assessment and enables the documentation of
findings. The teased-fiber technique is auxiliary to histopathology, and to limit
the workload and save costs, it can be performed on only a few specimens selected
for better characterization of changes recognized or suspected in tissue
sections. In particular, segmental demyelination and early stages of Wallerian or
secondary axonal degeneration can be recognized in teased fibers. Segmental
demyelination is characterized by loss of fully myelinated segments and their
replacement by newly formed short and thin segments, remyelinating the preserved
axon. The early stage of secondary axonal degeneration is recognized by formation
of ovoidal fiber fragments in the midinternodal region.
PMID- 10668998
TI - Practical aspects of neuropathology: a technical guide for working with the
nervous system.
AB - Toxicologic pathologists are evaluating tissues from the central and peripheral
nervous systems with increasing frequency. This change is being driven by
recently established regulatory guidelines and intense interest in developing
pharmaceutical compounds to treat various nervous system disorders. However,
morphologic evaluation of the nervous system by light or electron microscopy
requires special understanding and effort. Here, we review the general concepts
of fixation for the nervous system, explain perfusion procedures for optimal
preservation, and provide information on handling tissues to avoid artifacts. In
general, fixation with aldehydes is recommended for nervous tissue (a combination
of paraformaldehyde and glutaraldehyde is preferred). Electron microscopic
studies require fixatives of the highest purity possible, typically
paraformaldehyde prepared fresh from powder mixed with high-grade glutaraldehyde.
The final osmolality of the solution should be slightly hypertonic, in the range
of 400-600 mOsmol. Slight hypertonicity is very important and will facilitate
maintenance of vascular distention during whole-body perfusion, which is the best
method for producing high-quality tissue preparations. Special effort is
necessary for handling nervous tissue in a way that minimizes artifacts because
chemical fixation is not completed immediately following the perfusion. These
technical details should help toxicologic pathologists in their efforts to work
with the nervous system, thereby increasing their effectiveness in supporting
safety characterization of new test materials undergoing toxicologic assessments.
PMID- 10668999
TI - ECOs, FOBs, and UFOs: making sense of observational data.
AB - Systematic observations of rat behavior are required for both standard subchronic
safety studies and for neurotoxicity studies. The requirements specify subjective
out-of-cage observations (eg, posture, gait, and reactivity to various stimuli
such as, auditory, tactile, and noxious) using defined scales. Measurement of
forelimb/hind limb grip strength, landing foot splay, and locomotor activity are
also required. The observational endpoints are organized into a battery, eg, the
Environmental Protection Agency functional observational battery (FOB) or
expanded clinical observations (ECO). Functional and neuropathologic data are
most easily integrated when the functional endpoints are organized as a
neurologic exam (ie, each endpoint has a known anatomical basis and there are
sufficient endpoints to cover the nervous system). Current batteries do not
constitute a neurologic exam. Although ECOs and FOBs contain some components of a
neurologic exam (ie, observations of gait, response to pinch), the anatomic basis
for other components (eg, hind limb splay) is poorly defined. And although some
functions (eg, somatomotor) are well characterized by current batteries, others
(eg, vision, somatosensation) are evaluated less effectively. The measurement of
locomotor activity in a novel environment is one of the most problematic parts of
current functional testing batteries, although contemporary technology may
provide opportunities for improving this test. The influence of inherent
limitations of functional test methods is magnified by factors associated with
testing for neurotoxicant-related effects during safety studies. First, most
personnel at contract laboratories have little or no formal training in
conducting and interpreting a neurologic examination. Second, most neurotoxicant
related lesions are bilateral, which paradoxically may produce more subtle
effects than unilateral lesions. Third, most chemicals will be tested only once,
and sponsors are reluctant to evaluate results in "real time" and amend protocols
to add endpoints (eg, neurophysiological tests) to clarify functional effects.
Pathologists should have realistic expectations about the opportunities for
integrating functional and neuropathologic findings.
PMID- 10669000
TI - Ototoxicity: an argument for evaluation of the cochlea in safety testing in
animals.
AB - The cochlea is one of the more common targets for toxic effects, yet current
toxicologic screening in animals does not routinely evaluate the cochlea as a
potential target organ. Although histopathologic sections are routinely taken
from the eye and the optic nerve and tract and most studies include at least 1
section through the nasal cavity and olfactory mucosa, the cochlea is not
histopathologically examined in routine toxicity studies. Unfortunately, routine
clinical examinations frequently miss ototoxicity because rodents and other
species can lose most of their high-frequency hearing and still respond to most
ambient noises. Ototoxicity as a deficiency in toxicologic screening can be
remedied by using well-established histopathologic and behavioral methods or
electrophysiologic methods, such as brain stem auditory evoked responses (BAERs).
Once the equipment is in place, BAERs can be obtained quickly and easily for
ototoxicity screening (approximately 15 minutes for paired testing of 2 rats and
30 minutes each for dogs). BAERs also can be used in virtually all mammalian
species. Three or 4 probe frequencies (eg, 4, 8, 16, and 32 kHz), representing
different areas of the cochlea, can be tested in a few minutes with subcutaneous
electrodes under short-acting chemorestraint. Given the availability of several
approaches to screening for ototoxicity and the importance of the auditory
function in human health, safety tests of chemicals and drugs should include an
effective screening test for ototoxicity.
PMID- 10669001
TI - Characterization of carbon disulfide neurotoxicity in C57BL6 mice: behavioral,
morphologic, and molecular effects.
AB - Female C57BL6 mice were exposed to 0 or 800 ppm carbon disulfide (CS2), 6 h/d, 5
d/wk for 20 weeks. The neurologic function of all mice was assessed once at the
end of exposures using a functional observational battery. General health effects
included a decrease in body weight gain, piloerection, hunched body posture, and
ptosis. Treatment-related effects included altered gait (uncoordinated placement
of hind limbs and ataxia) and impaired function on an inverted screen test. In
addition, rearing and locomotor movement were decreased in treated mice. Focal to
multifocal axonal swelling was seen predominantly in the muscular branch of the
posterior tibial nerve, and occasionally giant axonal swelling was detected in
the lumbar segment of the spinal cord. Electron microscopic examination revealed
swollen axons with massive accumulation of neurofilament proteins within the
axoplasm. Covalent cross-linking of erythrocyte spectrin (surrogate protein to
neurofilament protein) was demonstrated in mice exposed to CS2 but not in mice
receiving filtered air. These data provide supportive evidence that covalent
cross-linking of neurofilament proteins is a significant feature of the axonal
swellings in mice produced by inhalation exposure to CS2.
PMID- 10669002
TI - The role of developmental neurotoxicology studies in risk assessment.
AB - A number of questions have been raised about the use of the US Environmental
Protection Agency's Developmental Neurotoxicity Testing Guideline (DNTG) in the
hazard identification of chemicals. The applicability and sensitivity of animal
tests in the DNTG relative to human developmental neurotoxicity have recently
been questioned. In a workshop held in 1989, participants compared the effects of
several known developmental neurotoxicants in humans and animal models and
concluded that the DNTG would have detected known human developmental
neurotoxicants. They also concluded that although procedural differences may
differ in the testing of humans and animals, the neurobiologic functions (ie,
autonomic, sensory, motor, and cognitive) affected by chemical exposure were
similar. In cases where the DNTG has been compared with other measures of
reproductive and developmental toxicity, the DNTG has been relatively sensitive
and specific. To date, DNTGs have been required 12 times, for 9 pesticides and 3
solvents. The sensitivity of the measures in the DNTG relative to other measures
of developmental and adult toxicity supports the continued use of the DNTG in
risk assessment.
PMID- 10669003
TI - Morphometric analysis of the developing rat brain.
AB - In 2 studies, a method of linear morphometry was applied to regulatory
developmental neurotoxicity studies in the rat. The first study involved the
development of the brain during postnatal days (PNDs) 7-63, and the second
involved the effects of 8 mg/kg i.p. trimethyltin chloride (TMT) to rats at PND
8, with morphometry performed at PNDs 12 and 24. The results of the TMT linear
morphometry were compared with those from stereologic counting of neurons in the
cerebral cortex, piriform cortex, and hippocampus. Stereology produces more
meaningful data than simple linear morphometry for use in the regulatory
assessment of the developmental neurotoxicity potential of compounds.
PMID- 10669004
TI - Phenotype vs genotype in the evolution of astrocytic brain tumors.
AB - Astrocytic brain tumors are the most frequent human gliomas and they include a
wide range of neoplasms with distinct clinical, histopathologic, and genetic
features. Diffuse astrocytomas are predominantly located in the cerebral
hemispheres of adults and have an inherent tendency to progress to anaplastic
astrocytoma and (secondary) glioblastoma. The majority of glioblastomas develop
de novo (primary glioblastomas), without an identifiable less-malignant precursor
lesion. These subtypes of glioblastoma evolve through different genetic pathways,
affect patients at different ages, and are likely to differ in their responses to
therapy. Primary glioblastomas occur in older patients and typically show
epidermal growth factor receptor (EGFR) overexpression, PTEN mutations, p16
deletions, and, less frequently, MDM2 amplification. Secondary glioblastomas
develop in younger patients and often contain TP53 mutations as their earliest
detectable alteration. Morphologic variants of glioblastoma were shown to have
intermediate clinical and genetic profiles. The giant cell glioblastoma
clinically and genetically occupies a hybrid position between primary (de novo)
and secondary glioblastomas. Gliosarcomas show identical gene mutations in the
gliomatous and sarcomatous tumor components, which strongly supports the concept
that there is a monoclonal origin for gliosarcomas and an evolution of the
sarcomatous component due to aberrant mesenchymal differentiation in a highly
malignant astrocytic neoplasm.
PMID- 10669005
TI - A mouse model for glioma: biology, pathology, and therapeutic opportunities.
AB - The epidermal growth factor receptor (EGFR) gene is amplified or mutated in 30
50% of human glioblastoma multiforme. These mutations are usually associated with
deletions of the INK4a-ARF locus, which encodes 2 gene products (p16INK4a and
p19ARF) involved in cell cycle arrest and apoptosis. We have investigated the
role of EGFR mutation in gliomagenesis using avian retroviral vectors to transfer
a mutant EGFR gene to glial precursors and astrocytes in transgenic mice. These
mice express tv-a, a gene encoding the retrovirus receptor TVA, which is under
the control of brain cell type-specific promoters. We demonstrate that expression
of a constitutively active, mutant form of EGFR in cells in the glial lineage can
induce lesions with many similarities to human gliomas, including increased cell
density, vascular proliferation, and immunohistochemical staining for glial
fibrillary acidic protein (GFAP) and nestin. We also demonstrate that primary
astrocytes cultured from transgenic mice expressing tv-a from the GFAP promoter
are efficiently infected in culture, and such genetically modified cell cultures
can be tumorigenic in nude mice. The combinations of genetic lesions (eg, mutated
EGFR, INK4a-/-) leading to tumor formation in these 2 mouse systems are similar
to those found in human gliomas. These genetically defined animal models for
gliomas will allow for the testing of therapies that are targeted specifically at
the gene products involved in the pathogenesis of gliomas.
PMID- 10669006
TI - Morphologic characterization of spontaneous nervous system tumors in mice and
rats.
AB - Spontaneous rodent nervous system tumors, in comparison to those of man, are less
well differentiated. Among the central nervous system (CNS) tumors, the
"embryonic" forms (medulloblastoma, pineoblastoma) occur both in rodents and
humans, whereas the human "adult" forms (gliomas, ependymomas, meningiomas) have
fewer counterparts in rodents. In general, the incidence of spontaneous CNS
tumors is higher in rats (>1%) than in mice (>0.001%). A characteristic rat CNS
tumor is the granular cell tumor. Usually it is associated with the meninges, and
most meningeal tumors in rats seem to be totally or at least partly composed of
granular cells, which have eosinophilic granular cytoplasm, are periodic acid
Schiff reaction (PAS)-positive, and contain lysosomes. Such tumors are frequently
found on the cerebellar surface or at the brain basis. Rat astrocytomas are
diffuse, frequently multifocal, and they invade perivascular spaces and meninges.
The neoplastic cells with round to oval nuclei and indistinct cytoplasm grow
around preexisting neurons, producing satellitosis. In large tumors, there are
necrotic areas surrounded by palisading cells. Extensive damage of brain tissue
is associated with the presence of scavenger cells that react positively with
histiocytic/macrophage markers. The neoplastic astrocytes do not stain positively
for glial fibrillary acidic protein; they probably represent an immature
phenotype. In contrast to neoplastic oligodendroglia, they bind the lectin RCA-1.
Astrocytomas are frequently located in the brain stem, especially the basal
ganglia. Rat oligodendroglial tumors are well circumscribed and frequently grow
in the walls of brain ventricles. Their cells have water-clear cytoplasm and
round, dark-staining nuclei. Atypical vascular endothelial proliferation occurs,
especially at the tumor periphery. Occasionally in the oligodendrogliomas,
primitive glial elements with large nuclei occur in the form of cell groups that
form rows and circles. Primitive neuroectodermal tumors of rats, such as pineal
tumors or medulloblastomas, appear to have features similar to those found in
man. In mice, the meningeal tumors are mostly devoid of granular cells and the
astrocytomas are similar to those occurring in rats, whereas spontaneous
oligodendrogliomas are observed extremely rarely. Tumorlike lesions, such as
lipomatous hamartomas or epidermoid cysts, are occasionally encountered in the
mouse CNS. It is suggested that we classify rodent CNS lesions as "low grade" and
"high grade" rather than as "benign" and "malignant." The size of CNS tumors is
generally related to their malignancy. Tumors of the peripheral nervous system
are schwannomas and neurofibromas or neurofibrosarcomas consisting of Schwann
cells, fibroblasts, and perineural cells. Well-differentiated schwannomas are
characterized by S-100 positivity and the presence of basement membrane. They
show either Antoni A pattern with fusiform palisading cells or Antoni B pattern,
which is sparsely cellular and has a clear matrix. The rat develops specific
forms of schwannomas in the areas of the submandibular salivary gland, the
external ear, the orbit, and the endocardium. Spontaneous ganglioneuromas occur
in the rat adrenal medulla or thyroid gland. Compared to experimentally induced
neoplasms, the spontaneous tumors of the rodent nervous system are poor and
impractical models of human disease, although they may serve as general
indicators of the carcinogenic potential of tested chemicals.
PMID- 10669007
TI - Evaluation of ENU-induced gliomas in rats: nomenclature, immunochemistry, and
malignancy.
AB - Rats developed mixed gliomas, oligodendrogliomas, and a few astrocytomas in
response to transplacental ethylnitrosourea. The neoplastic cell composition of
mixed gliomas must be defined; this study required a 20-80% admixture of
neoplastic astrocytes and oligodendroglia for the diagnosis of mixed glioma. A
battery of immunoantibodies, including Leu-7, S-100, and vimentin, were helpful
in classifying rat gliomas, and the histologic features of each tumor type are
described. Other brain tumor characteristics that may decide the outcome of
carcinogenicity studies include incidence, multiplicity, latency, fatality, size,
and malignancy. The size of tumors was determined by measuring their 3
dimensional volumes. Brain tumor volume was found to be highly correlated with
malignancy and fatality. Systematic evaluation of the malignancy of brain tumors
is an important but often overlooked adjunct method of measuring the
effectiveness of a carcinogen. A system to estimate malignancy, one that grades 9
tumor characteristics and weights, each according to clinical outcome, was
developed. It was found that mixed gliomas grew larger, had a shorter latency,
and were significantly more malignant than were other gliomas.
PMID- 10669008
TI - Tumors of the nervous system in carcinogenic hazard identification.
AB - In the absence of adequate data on humans, it is biologically plausible and
prudent to regard agents and mixtures for which there is sufficient evidence of
carcinogenicity in experimental animals, usually rats and mice, as if they
presented a carcinogenic risk to humans. Prediction of cancer sites in humans
from bioassay data in rodents is much less certain, however, regardless of organ
or tissue. For tumors of the nervous system, there is practically no basis for
judging the validity of such predictions, as only ionizing radiation is known to
cause tumors of the central nervous system (CNS) in humans. Brain tumors are
relatively uncommon findings in bioassays and are rare in untreated rodents, even
in rats, which appear to be the most susceptible species. However, CNS tumors
have been readily induced in rodents by systemic exposures to some chemicals,
notably N-nitrosoalkylureas and other alkylating agents and certain alkyl
hydrazine derivatives. CNS tumors in rodents have played a significant role in
carcinogenic hazard evaluations of several other chemicals, including
acrylonitrile, ethylene oxide, and acrylamide, and have been implicated as part
of the tumor spectrum induced by vinyl chloride and certain inorganic lead
compounds. In some of these evaluations, it is not certain that all tumors
diagnosed as primary brain tumors were correctly identified. Diagnostic
difficulties have been presented by undifferentiated small-cell tumors that may
invade the brain, including carcinomas of the nasal cavity and undifferentiated
schwannomas arising in cranial nerve ganglia, and by the difficulty of reliably
distinguishing between focal reactive gliosis and early glial neoplasms. The most
striking experimental finding regarding the induction by chemicals of tumors of
the nervous system is the dramatically greater susceptibility of the fetal and
neonatal nervous system to some carcinogens, as compared with the susceptibility
of the nervous system in adults of the same species.
PMID- 10669009
TI - Plant cyanogenic glycosides.
AB - The cyanogenic glycosides belong to the products of secondary metabolism, to the
natural products of plants. These compounds are composed of an alpha
hydroxynitrile type aglycone and of a sugar moiety (mostly D-glucose). The
distribution of the cyanogenic glycosides (CGs) in the plant kingdom is
relatively wide, the number of CG-containing taxa is at least 2500, and a lot of
such taxa belong to families Fabaceae, Rosaceae, Linaceae, Compositae and others.
Different methods of determination are discussed (including the indirect
classical photometrical and the new direct chromatographic ones). The genetic
control of cyanogenesis has no unique mechanism, the plants show variation in the
amount of the produced HCN. The production of HCN depends on both the
biosynthesis of CGs and on the existence (or absence) of its degrading enzymes.
The biosynthetic precursors of the CGs are different L-amino acids, these are
hydroxylated then the N-hydroxylamino acids are converted to aldoximes, these are
turned into nitriles. The last ones are hydroxylated to alpha-hydroxynitriles and
then they are glycosilated to CGs. The generation of HCN from CGs is a two step
process involving a deglycosilation and a cleavage of the molecule (regulated by
beta-glucosidase and alpha-hydroxynitrilase). The tissue level
compartmentalisation of CGs and their hydrolysing enzymes prevents large-scale
hydrolysis in intact plant tissue. The actual level of CGs is determined by
various factors both developmental and ecological ones, which are reviewed too.
The last part of the present work demonstrates the biological roles of CGs in
plant physiological processes and in plant defence mechanisms as well. The effect
of CGs (HCN) on different animals, the symptoms of poisonings are discussed to
cows, sheep, donkeys, horses and chicks. Finally, the poisonous effects of
cassava (Manihot esculenta) roots are summarised on experimental animals and on
the human organism.
PMID- 10669010
TI - First report on the distribution of orally administered microcystin-LR in mouse
tissue using an immunostaining method.
AB - The purpose of this study was to investigate the distribution of microcystin-LR
(MCLR) orally administered to mice using an immunostaining method. MCLR was
orally dosed at 500 microg/kg to aged Balb/C and ICR mice and their lethality was
23.9%. The former was more sensitive to MCLR than the latter, suggesting that
oral toxicity by MCLR is related to the animal strains tested, although the
pathological and immunostaining changes were essentially the same in both
strains. According to this method the distribution of MCLR and related compounds
were indicated as the red staining. Particularly, livers of dead aged mice were
intensively stained. The main route of absorption was considered to be the small
intestine because the villi contained a large amount of MCLR in both surface
epithelial cells and lamina propria, resulting in erosion. The absorbed MCLR was
contained in blood plasma and moved to the liver, lung, and heart, and finally to
capillaries of the whole body. Excretion of MCLR was shown in the mucous from
goblet cells in both the small intestine and large intestine.
PMID- 10669011
TI - Some toxic and enzymatic activities of Bothrops ammodytoides (yarara nata) venom.
AB - Bothrops ammodytoides, the smallest representative of this genus, is found only
in Argentina. Venom was extracted from thirty adult specimens (35-70 cm in
length, 90-300 g in weight) captured in the Province of Buenos Aires and kept in
captivity. Venom yield was 3-30 mg. SDS-PAGE showed strong bands at 14.0; 23-25;
45; 54 and 63 kDa and weak bands at 17.0; 30.0; 40.0 and 85.0 kDa. Toxic
activities were: LD50 (intravenous, mice) 0.5+/-0.2 microg/g; minimal
procoagulant dose on human plasma (MPD-P) 35+/-2 mg/l; and minimal
defibrinogenating dose (MDD, mice) 6-12 microg. Hemorrhagic and/or necrotic
activities appear to play a major role in lethality; minimal hemorrhagic dose
(MHD, mice) is 10+/-2 microg/g and minimal necrotizing dose (MND, mice) is 38+/-5
microg. The LD50, MPD-P and MND are among the lowest in venoms from Bothrops
species found in Argentina. B. ammodytoides venom exhibited high proteolytic and
phospholipase A2 activities. Most of the B. ammodytoides venom components cross
react with Bivalent Bothropic antivenom (Instituto Nacional de Produccion de
Biologicos ANLIS Dr. G. Malbrin, against B. alternatus and B. neuwiedii venoms).
One ml of antivenom neutralizes 1.2 mg of B. ammodytoides venom.
PMID- 10669012
TI - Purification and characterization of BaH4, a hemorrhagic metalloproteinase from
the venom of the snake Bothrops asper.
AB - A hemorrhagic metalloproteinase, named BaH4, was isolated from the venom of the
snake Bothrops asper by a combination of ion-exchange chromatography on DEAE
Sepharose and gel filtration on Sephacryl S-200. BaH4 is a 69 kDa protein with a
pI of 5.3. It was recognized by antibodies raised against hemorrhagic
metalloproteinase BaH1 isolated from B. asper venom, with a reaction of partial
immunologic identity. BaH4 shows proteolytic activity on biotinylated casein,
hide powder azure and fibrin, although having lower activity than crude B. asper
venom and metalloproteinase BaP1 isolated from the same venom. BaH4 hydrolyzed
fibronectin, laminin and type IV collagen in vitro, albeit at a relatively high
enzyme:substrate ratio. Proteolytic activity was inhibited by chelating agents
and 2-mercaptoethanol, but not by soybean trypsin inhibitor. Prominent hemorrhage
developed in gastrocnemius and cremaster muscles after administration of BaH4.
Moreover, it induced lethality in mice after intravenous injection, with an LD50
of 0.37 microg/g. Histological observations showed conspicuous pulmonary
hemorrhage when the enzyme was injected intravenously. BaH4 is a hemorrhagic
metalloproteinase which may play a relevant role in local and systemic bleeding
characteristic of B. asper envenomations.
PMID- 10669013
TI - An investigation of the biological activity of bullrout (Notesthes robusta)
venom.
AB - Bullrout envenomation is known to cause intense pain. Crude bullrout venom and
venom fractions were assessed for protease, hyaluronidase, phospholipase and
hemolytic activities, reactivity with stonefish antivenom, lethality to brine
shrimp and ability to elicit pain in human subjects. Compared with venom obtained
from frozen specimens, live fish venom-milking techniques rendered greater venom
potency and improved storage characteristics. Although mild proteolytic and
hemolytic activity was observed, crude venom demonstrated no hyaluronidase or
phospholipase A2 activity, did not affect brine shrimp, or show antigenicity with
stonefish antivenom. A single venom protein isolated from bullrout venom is
attributed with causing pain in human subjects. The sensations elicited by this
novel algesic protein are consistent with chemical stimulation of polymodal
nociceptors.
PMID- 10669015
TI - KTX3, the kaliotoxin from Buthus occitanus tunetanus scorpion venom: one of an
extensive family of peptidyl ligands of potassium channels.
AB - A new ligand of the K+ channels sensitive to KTX was purified from the venom of
Buthus occitanus tunetanus, using two steps of high-performance-liquid
chromatography and by following its ability to compete with [125I]-KTX for
binding to the KTX receptor on rat brain synaptosomes. Amino-acid analysis, amino
acid sequencing and mass spectroscopy defined this new ligand. KTX3, as a 37
amino acid peptide, with three disulfide bridges. Its sequence shares 76%
identity with KTX. The main differences between the two peptides are in the N
terminal region and the residue position 34 located in the region involved in
channel recognition. These differences may explain the 5-fold lower binding
affinity of KTX3, IC50=50 pM, than KTX to rat brain synaptosomes. Specific
antibodies raised against KTX (1-37) were not able to recognize KTX3.
PMID- 10669014
TI - Isolation and structures of grammistins, peptide toxins from the skin secretion
of the soapfish Grammistes sexlineatus.
AB - Two peptide toxins (named grammistins Gs 1 and Gs 2) with hemolytic and
ichthyotoxic activities were isolated from the skin secretion of the soapfish
Grammistes sexlineatus. Grammistin Gs 2 showed 6-11 x higher hemolytic activity
and 10x higher ichthyotoxicity than grammistin Gs 1. The complete amino acid
sequences of Gs 1 comprising 25 residues and Gs 2 comprising 24 residues were
determined. Although a search by the database failed to find any homologous
toxins from other sources, the grammistins were similar in secondary structures
as well as biological activities to the two classes of peptide toxins, melittin
from the bee venom and pardaxins from the skin secretion of two species of soles.
CD experiments and helical wheel projections showed that the grammistins were
randomly coiled in distilled water but formed amphiphilic alpha-helices in the
presence of SDS micelles. In addition, they were found to be surface seeking
peptides by the Eisenberg plot and assumed to exist as aggregates of 3-4
molecules. Interestingly, grammistin Gs 2 is much more abundant in amphiphilic
alpha-helices and much higher in biological activities than melittin and
pardaxins as well as grammistin Cs 1.
PMID- 10669016
TI - Induction of neutralizing antibodies against Tityus serrulatus toxins by
immunization with a recombinant nontoxic protein.
AB - An immunogenic nontoxic protein (TsNTxP) was purified from the venom of the
scorpion Tityus serrulatus (Ts). This peptide is composed of 63 amino acid
residues with a high degree of structural homology with the toxins isolated from
Ts. The nucleotide sequence of the gene that encodes TsNTxP was obtained and also
showed a high degree of similarity with genes encoding Tityus toxins [Guatimosim,
S.C.F., Prado, V.F., Diniz, C.R., Chavez-Olortegui, C.. Kalapothakis, E., 1999.
Molecular cloning and genomic analysis of TsNTxP; an immunogenic protein from
Tityus serrulatus scorpion venom. Toxicon 37, 507-517]. In the present study the
TsNTxP gene was expressed in E. coli BL21DE3 cells as a fusion protein with
maltose-binding protein. The recombinant protein (TsNTxPrec) was purified by
affinity chromatography and used as an immunogen in rabbits. The antigenic
specificity of anti-TsNTxPrec antibodies was compared by an enzyme-linked
immunosorbent assay using TsNTxP, TstFG50 (the fraction of Ts venom that
represents most of the toxicity of the crude venom) and the crude venom, to coat
microtitration plates. Anti-TsNTxPrec antibodies had a comparable high cross
reactivity for all antigens tested. Concentrations of Ts venom equivalent to 20
LD50 were effectively neutralized by 1 ml of the anti-TsNTxPrec serum. This
result provides basic data for the use of such recombinant scorpion protein as an
immunogen in the development of antivenoms for clinical use.
PMID- 10669017
TI - Bleeding from the small intestine caused by aplysiatoxin, the causative agent of
the red alga Gracilaria coronopifolia poisoning.
AB - The cause of death by aplysiatoxin poisoning was bleeding from the small
intestine in mice. The pathological changes related to the cause and progression
of bleeding were studied morphologically. Bleeding from the capillaries was
observed 60 min after i.p. treatment at 250 microg/kg, and this was preceded by
dilatation of the lymphatic vessel and congestion of capillaries in the lamina
propria from 10 min after the injection. At 100 microg/kg i.v., the target
vessels were in the lung, where fibrin deposition was observed in the dilated
pulmonary artery, and blood flowed out through a gap in the artery. Then, in the
small intestine, similar changes appeared to have occurred, and bleeding was
induced in two characteristic ways, one through deposition of fibrin in the lumen
and the other via distension of the capillary wall.
PMID- 10669018
TI - Paralizing activity of the Parawixia bistriata crude venom in termites: a new
bioassay.
AB - Spider venoms have high specificity to neuronal elements. Therefore, the use of
venom has been important in the characterisation of mammal and insect nervous
systems. The evaluation of insect paralysis has been an important tool for
distinguishing the biological effects of venom. In this study we describe the
paralysing effect of a spider crude venom (Parawixia bistriata) in termites,
utilising a new bioassay. The crude venom of P. bistriata caused an irreversible
and dose-dependent paralysis in the animals in the following doses: 2.10(-5) U;
2.10(-4) U; 2.10(-3) U; 2.10(-2) U and 0.12 U (1 U = 1 gland). This bioassay will
allow for easy and direct evaluation of biological effects from different venoms
and purified fractions.
PMID- 10669019
TI - Neutralization of the hemorrhagic activity of Bothrops and Lachesis snake venoms
by a monoclonal antibody against mutalysin-II.
AB - One mAb reactive with mutalysin-II, a hemorrhagic metalloproteinase isolated from
Lachesis muta muta venom, was produced in mice immunized with L. m. muta venom.
Indirect ELISA was employed to compare the antigenic cross-reactivity among the
venoms from Bothrops snakes. The mAb anti-mutalysin-II efficiently neutralized
the hemorrhagic effect of both mutalysin-II and L. m. muta crude venom.
Furthermore, the mAb were cross-reactive with B. alternatus, B. atrox, B.
itapetiningae, B. jararaca and B. neuwiedii and showed variable potencies in
neutralizing the hemorrhagic activity of several bothropic venoms.
PMID- 10669020
TI - Bibliography of toxinology.
PMID- 10669021
TI - Are we as toxinologists overlooking vouchers?
PMID- 10669022
TI - The effect of Portuguese Man-of-war (Physalia physalis) venom on calcium, sodium
and potassium fluxes of cultured embryonic chick heart cells.
AB - Portuguese Man-of-war venom markedly increases calcium (45Ca2+) influx into
primary, cultured, embryonic chick heart cells. This action is dose-dependent,
but is unaffected by organic calcium blockers (diltiazem, verapamil, nifedipine,
nimodipine and mibefradil). On the other hand, certain trivalent (La3+, Gd3+) and
divalent (Zn2+, Ni2+, Cu2+, Mn2+) metals inhibit venom-induced calcium influx.
Sodium (22Na+) influx into chick heart cells is also significantly increased by
Man-of-war venom. Flecainide does not block venom-induced sodium influx. The
efflux of the potassium analogue, 86Rb+, from heart cells is also significantly
increased by the venom. The venom, however, has little or no effect on rubidium
(86Rb+) or 2-deoxy-D-[2-3H] glucose influx.
PMID- 10669023
TI - Occurrence of the toxin dehydroabietic acid in Salmonella typhimurium.
AB - Many strains of Salmonella typhimurium studied in our lab demonstrated marked
differences in the pathogenicity for guinea pig, chicken and Hela cells. As a
result, a pathogenic strain of S. typhimurium, strain 9SR2, was evaluated for
lipophilic components that may be associated with virulence using gas
chromatography/mass spectrometry. The hydroxylated fatty acids 2
hydroxytetradecanoic acid (2-OH-14:0) and 3-hydroxytetradecanoic acid (3-OH-14:0)
often present in lipid A, a potent endotoxin, were observed as their methyl
esters. The cyclic fatty acids methylene-hexadecanoic acid (C17delta) and
methyleneoctadecanoic acid (C19delta) also were detected. The nephrotoxic and
neurotoxic diterpenoid resin acid, dehydroabietic acid, was observed for the
first time from S. typhimurium in both the total lipid and diglyceride fractions
and determined as its methyl ester at m/z 314.2246. Due to its previously
established toxicity, dehydroabietic acid may be a factor associated with
virulence of S. typhimurium.
PMID- 10669024
TI - An ultrasensitive competitive binding assay for the detection of toxins affecting
protein phosphatases.
AB - An ultrasensitive assay is described for microcystin-LR and other substances
(microcystins, nodularin, okadaic acid, calyculin A, tautomycin) which block the
active site of protein phosphatases (PP) 1 and 2A. The assay is based on
competition between the unknown sample and [125I]microcystin-YR for binding to
the catalytic subunit of PP2A. The PP2A-bound [125I]microcystin-YR was stable
(half-time of dissociation = 1.8 h), allowing non-bound [125I]microcystin-YR to
be removed by Sephadex G-50 size-exclusion chromatography. Compared to current
assays based on inhibition of protein phosphatase activity the present assay was
more robust against interference (from fluoride, ATP, histone, and casein), and
had an even better sensitivity. The detection limit was below 50 pM (2.5 fmol)
for nodularin and microcystin-LR, and below 200 pM (10 fmol) for okadaic acid.
The method was used successfully to detect extremely low concentrations of either
microcystin or nodularin in drinking water or seawater, and okadaic acid in
shellfish extract.
PMID- 10669025
TI - Purification and cDNA cloning of an insecticidal protein from the venom of the
scorpion Orthochirus scrobiculosus.
AB - Injection of crude venom from the scorpion Orthochirus scrobiculosus into larvae
of Heliothis virescens (Lepidoptera: Noctuidae) caused trembling and
uncoordinated movement before development of a progressive and prolonged flaccid
paralysis. The isolation of the toxin (OsI-1) responsible for this effect of O.
scrobiclosus venom is described. The molecular mass of OsI-1 toxin was 6994 Da,
as determined by desorption mass spectroscopy. The complete primary structure of
OsI-1 was deduced from the sequence of cDNA clones obtained by rapid
amplification of cDNA ends (RACE) PCR. Comparison of the deduced amino acid
sequence of OsI-1 with those of other insecticidal scorpion toxins indicates that
it is a sodium (Na+) channel active depressant insect-selective toxin. The
analysis of amino acid sequence of the toxin in conjunction with mass
spectroscopy data indicates post-translational modification in maturation with
the removal of 3 C-terminal amino acids and amidation of the C-terminus.
PMID- 10669026
TI - Characterisation of antibacterial activity of peptides isolated from the venom of
the spider Cupiennius salei (Araneae: Ctenidae).
AB - The characterisation of the antimicrobial activity of five antibacterial
peptides, isolated from the venom of the neotropical wandering spider Cupiennius
salei is reported here. The peptides have a molecular mass, determined by
electrospray ionisation-mass spectrometry, between 3-4 kDa. Minimal inhibitory
concentrations against five different bacteria species were determined by a
liquid growth inhibition assay. All five peptides showed minimal inhibitory
concentrations that are comparable to those of other known antibacterial
peptides, like insect defensins and cecropins, found in the last years in a large
diversity of animals. The peptides are supposed to lyse the cells by formation of
either distinct channels or pores, but their mode of action is not yet revealed.
PMID- 10669027
TI - Development of sensitive colorimetric capture elisas for Clostridium botulinum
neurotoxin serotypes A and B.
AB - Sensitive and specific enzyme-linked immunosorbent assays were developed to
detect Clostridium botulinum neurotoxin serotypes A (BoNT A) and B (BoNT B) in
assay buffer and human serum. The assay is based upon affinity-purified horse
polyclonal antibodies directed against the approximately 50 kDa C-fragments of
each toxin. Standard curves were linear over the range of 0.1-10 ng mL. Detection
was possible at 0.2 ng mL (20 pg/well) and accurate quantitation at 0.5 ng/mL (50
pg well) in assay buffer and 10% human serum. Variations between triplicates was
typically 5-10%. Less than 1% cross reactivity occurred between other serotypes
when each assay was performed against serotypes A, B and E. When tested against
toxins complexed to their associated nontoxic proteins, interference was absent
(BoNT B) or < 25% (BoNT A). These assays demonstrate sensitivity close to that of
the mouse bioassay without the use of animals and in a much simpler format than
other reported assays of similar sensitivity.
PMID- 10669028
TI - Dose-dependent cardiovascular and neuromuscular effects of stonefish (Synanceja
trachynis) venom.
AB - There has been recent debate regarding the labile nature of stonefish venoms and
the pharmacology of their breakdown products. The present study examined the
cardiovascular and neuromuscular effects of lyophilised venom, and conducted a
preliminary investigation of freshly milked venom. Lyophilised venom (20
microg/ml) caused endothelium-dependent relaxation in rat aortae that was
abolished by atropine (0.1 microM). In contrast, an endothelium-independent
contractile response occurred in porcine coronary arteries. However, in the
presence of atropine (10 nM), this became a relaxation response which was
attenuated by the B2 antagonist FR-173657 (0.1 microM) or by a combination of
idazoxan (1 microM) and propranolol (1 microM). In rat isolated atria,
lyophilised venom (4 microg/ml) caused a biphasic inotropic response consisting
of an initial decrease, and then increase, in force which were attenuated by
atropine (0.5 microM) and propranolol (5 microM), respectively. The increase in
force produced by venom was unaffected by reserpine pre-treatment suggesting a
direct action at adrenoceptors. In the anaesthetised rat, lyophilised venom (1
300 microg/kg, i.v.), caused a dose-dependent depressor response, with a
subsequent pressor response at higher concentrations (30-300 microg/kg, i.v.). In
the presence of atropine (1 mg/kg, i.v.), the depressor response to venom was
abolished, a transient pressor response unmasked and the secondary pressor
response augmented. In the additional presence of prazosin (50 microg/kg, i.v.),
the transient pressor response was abolished and the secondary pressor response
attenuated. Lyophilised venom had no significant effect on nerve-evoked (10
microg/ml) or directly-evoked (100 microg/ml) twitches of the chick biventer
cervicis muscle preparation. Milked venom (1 microl/ml) caused a biphasic
response (i.e., an initial relaxation followed by contraction) in rat aortae, a
contraction in porcine coronary arteries, complete cessation of rat isolated
atrial activity and markedly inhibited both nerve-evoked and directly-evoked
twitches of the chick biventer cervicis muscle preparation. In the anaesthetised
rat, milked venom (15 microl/kg, i.v.) caused immediate cardiovascular collapse.
It appears that the cardiovascular effects of stonefish venom are mediated by a
dose-dependent action at muscarinic receptors and adrenoceptors.
PMID- 10669029
TI - Clinical features and management of Hadronyche envenomation in man.
AB - Using case reports and a review of the literature, the clinical features of
envenomation by the genus of Australian funnel web spiders known as Hadronyche,
are characterised. Five cases are reported here, including the first life
threatening envenomation by Hadronyche species 14 (the Port Macquarie funnel
web). Two severe envenomations by Hadronyche cerberea (the Southern Tree funnel
web) and one each by Hadronyche formidabilis (the Northern Tree funnel web) and
Hadronyche infensa (the Darling Downs funnel web) are also described. The
clinical experience of the authors' provided the five cases described in detail
one of which has previously been reported in brief. Eight cases of Hadronyche
envenomation from the literature (Medline 1966-1998 and Embase 1980-1998) were
analysed in order to draw comparisons between this syndrome and the well
described envenomation syndrome of Atrax robustus (the Sydney funnel web).
Reports of funnel web spider antivenom use to Commonwealth Serum Laboratories
(CSL) between 1995 and June 1998 were also examined. The biology of these
dangerous spiders, their geographic distribution, venom characteristics and
management issues are addressed. It is concluded that bites from at least six
Hadronyche species have produced a life-threatening envenomation syndrome
clinically indistinguishable from that of Atrax robustus. Atrax robustus derived
antivenom is effective although antivenom requirements may be greater than for
Atrax envenomation. Antivenom supplies are limited and sufficient stocks to treat
a severe envenomation are unlikely to be found in any one institution. Pressure
immobilisation first aid is effective in delaying onset of envenomation, may
enhance local inactivation of venom and early removal can result in rapid
clinical deterioration.
PMID- 10669030
TI - Isolation of a funnel-web spider polypeptide with homology to mamba intestinal
toxin 1 and the embryonic head inducer Dickkopf-1.
AB - We have isolated and determined the amino acid sequence of a novel peptide
component from the venom of the Australian funnel-web spider Hadronyche versuta.
This 68-residue toxin, ACTX-Hvf17, does not function like classical neurotoxins
in modulating ion channel function as evidenced by its lack of insecticidal
activity and its inability to affect vertebrate smooth or skeletal muscle
contractility. The peptide shows significant sequence homology with mamba
intestinal toxin 1 (MIT1) and to a lesser extent with a variety of colipases. The
strong structural homology between MIT1 and porcine colipase leads us to propose
that ACTX-Hvf17 also adopts the MIT1/colipase three-dimensional fold. However, we
show that ACTX-Hvf17 has no colipase activity and does not stimulate muscle
contractility like MITI. We also show that MIT1 and ACTX-Hvf17 display
significant sequence homology with the C-terminal cysteine-rich domain of the
Dickkopf-1 family of proteins that induce head formation in developing embryos,
which leads us to propose that this domain of Dickkopf-1 also adopts the MIT1
colipase fold.
PMID- 10669031
TI - Quantification of crotamine, a small basic myotoxin, in South American
rattlesnake (Crotalus durissus terrificus) venom by enzyme-linked immunosorbent
assay with parallel-lines analysis.
AB - Intraspecific variation in Crotalus durissus terrificus venom composition was
studied in relation to crotamine activity. Crotamine induces paralysis in
extension of hind legs of mice and myonecrosis in skeletal muscle cells. To
determine whether the venom of crotamine-negative rattlesnake contains a quantity
of myotoxin incapable of inducing paralysis, we have developed a very sensitivity
immunological assay method, an enzyme-linked immunoabsorbent assay (ELISA),
capable of detecting 0.6 ng of purified crotamine. The parallel-lines analysis of
ELISA data showed to be useful because it shows the reliability of the
experimental conditions. A variation in the amount of myotoxin in the crotamine
positive venom was observed, but not less than 0.1 mg of crotamine per mg of
venom. It was not possible to detect it in crotamine-negative venom even at high
venom concentrations.
PMID- 10669032
TI - Regional and accelerated molecular evolution in group I snake venom gland
phospholipase A2 isozymes.
AB - In accordance with detection of a few phospholipase A2 (PLA2) isozyme genes by
Southern blot analysis, only two cDNAs, named NnkPLA-I , and NnkPLA-II, encoding
group I PLA2s, NnkPLA-I and NnkPLA-II, respectively, were isolated from the venom
gland cDNA library of Elapinae Naja naja kaouthia of Malaysia. NnkPLA-I and
NnkPLA-II showed four amino acid substitutions, all of which were brought about
by single nucleotide substitution. No existence of clones encoding CM-II and CM
III, PLA2 isozymes which had been isolated from the venom of N. naja kaouthia of
Thailand, in Malaysian N. naja kaouthia venom gland cDNA library was verified by
dot blot hybridization analysis with particular probes. NnkPLA-I and NnkPLA-II
differed from CM-II and CM-III with four and two amino acid substitutions,
respectively, suggesting that their molecular evolution is regional. The
comparison of NnkPLA-I, NnkPLA-II and cDNAs encoding other group I snake venom
gland PLA2s indicated that the 5'- and 3'-untranslated regions are more conserved
than the mature protein-coding region and that the number of nucleotide
substitutions per nonsynonymous site is almost equal to that per synonymous site
in the protein-coding region, suggesting that accelerated evolution has occurred
in group I venom gland PLA2s possibly to acquire new physiological functions.
PMID- 10669033
TI - Purification and some properties of a tetrodotoxin binding protein from the blood
plasma of kusafugu, Takifugu niphobles.
AB - A tetrodotoxin binding protein has been purified from the plasma of the puffer
fish kusafugu, Takifugu niphobles, through DEAE-cellulose treatment, ammonium
sulfate fractionation, Sephadex gelfiltrations and Sephacryl S-200 and
Cellulofine A-500 column chromatography. Final purification by HPLC on a TSK G
3000 SL column yielded a protein which showed only a single protein peak. The
molecular weight of the protein was estimated to be 116,000 and 91,000 by SDS
PAGE and mass spectrometry, respectively. A blast search on the amino-terminal
amino acid sequence of the purified protein revealed that the protein had no
homology to any other protein on data base.
PMID- 10669034
TI - Bibliography of toxinology.
PMID- 10669035
TI - Evaluation of NOx in the cardiovascular system: relationship to NO-related
compounds in vivo.
AB - Diverse attention should be paid to evaluating NOx (NO2- and NO3-) in plasma as
an index of endothelial nitric oxide (NO) formation in vivo. Nitric oxide, which
subsequently appears as NOx, originates from different types of NO synthase and
from nonenzymatic reactions. NOx also comes from exogenous sources such as food
and gastrointestinal microorganisms. The fate of the NO incorporated into
activation of guanylate cyclase, formation of nitrosyl hemoglobin (or
nitrosohemoglobin), nitrosothiols, peroxynitrite and its derivatives and other
possible compounds is not clear at present. However, some of these compounds
would produce NOx as by-products or as final products through metabolism.
Therefore, plasma NOx contains information about these pathways, although how
extensively these factors contribute to plasma NOx has not been quantitatively
defined. A theoretical simulation of NOx in the systemic circulation indicates
that only small changes are expected by inhibition or stimulation of endothelial
NO production. Measuring NOx production during coronary circulation has the
advantage that some degree of NOx accumulation is expected from intact
endothelial cells because an excretion system is absent in the heart.
PMID- 10669036
TI - Receptor-mediated modulation of voltage-dependent Ca2+ channels via
heterotrimeric G-proteins in neurons.
AB - The activity of voltage-dependent Ca2+ channels is highly regulated by
neurotransmitter receptors coupled to heterotrimeric G-proteins. In the
expression studies using cloned Ca2+ channel subunits, it has been clarified that
the main mechanism of the inhibition of N-type channel current is mediated
directly by G-protein betagamma subunits in a membrane-delimited and voltage
sensitive manner. In addition, recent studies have also clarified that N-type
channels are modulated by several G-protein alpha subunits in different ways.
Among them, G(alpha o) mediates a voltage-resistant inhibition of N-type current
by neurotransmitters. This type of inhibition is more apparent in the case of P/Q
type channels in both native cells and expression systems. Moreover, other G
protein subunits, such as G(alpha q) and G(alpha s), also seem to regulate N-type
channels in a membrane-delimited manner. The fine tunings of Ca2+ channel
activity by intracellular proteins have physiological and pathological meanings
in the regulation of Ca2+ influx into excitable cells by neurotransmitters and
pharmacological implications as novel drug targets for controlling Ca2+ influx.
PMID- 10669037
TI - Evaluation of the histamine H1-antagonist-induced place preference in rats.
AB - The place preferences by some histamine H1 antagonists, such as tripelennamine,
optical isomers of chlorpheniramine (dl-, d- and l-forms) and pyrilamine, in rats
were evaluated with the conditioned place preference paradigm. In the present
study, tripelennamine and all of the optical isomers of chlorpheniramine, but not
pyrilamine, produced a significant place preference. The degree of the place
preference induced by optical isomers of chlorpheniramine (6.0 mg/kg) did not
correlate with the H1-antagonistic potency of these drugs, suggesting that H1
antagonist-induced place preferences are not mediated by H1-receptor blockade.
The tripelennamine (3.0 mg/kg)- and dl-chlorpheniramine (6.0 mg/kg)-induced place
preferences were completely abolished by pretreatment with the dopamine D1
receptor antagonist SCH23390 (0.05 mg/kg). Furthermore, the doses of H1
antagonists that induced a place preference significantly reduced the levels of
DOPAC, which may be mediated by inhibition of dopamine uptake, in the limbic
forebrain (including the nucleus accumbens and olfactory tubercle). These results
suggest that some H1 antagonists induce rewarding effects, which may be mediated
by the activation of dopamine D1 receptors, followed by the inhibition of
dopamine uptake.
PMID- 10669038
TI - Different effects of trypsin inhibitors on intestinal gene expression of secretin
and on pancreatic bicarbonate secretion in CCK-A-receptor-deficient rats.
AB - The effects of oral administration of two synthetic trypsin inhibitors (camostate
and ONO-3403) and soybean trypsin inhibitor (SBTI) on cholecystokinin (CCK),
secretin gene expression and pancreatic secretion were examined in CCK-A-receptor
deficient (OLETF) rats. The rats were fed chow containing 0.1% trypsin inhibitors
for 7 days. To examine pancreatic secretion, the rats were prepared with cannulae
to drain the bile and pancreatic juice separately, a duodenal cannula and an
external jugular vein cannula. The animals were maintained in Bollman cages and
the experiments were conducted 4 days after surgery. The levels of CCK mRNA were
significantly increased by each treatment. The levels of secretin mRNA were
significantly increased by camostate and SBTI, but not by ONO-3403. Bicarbonate
secretion was significantly increased in rats treated with camostate and ONO
3403, but not SBTI, while protein secretion was not affected by any treatment.
These observations suggest that increased bicarbonate secretion produced by
synthetic trypsin inhibitors in CCK-A-receptor-deficient rats may not be due to
secretin but due to ONO-3403 in the circulation.
PMID- 10669039
TI - The lipophilic properties of angiotensin I-converting enzyme inhibitors do not
influence their diffusion through cultured endothelium.
AB - The background for these investigations was the discovery that formation of
angiotensin II by the renin angiotensin system can take place in extravascular
tissues (e.g., cardiomyocytes and neurons) and within single cells. Consequently,
the question arose about whether such tissue-based systems might be
differentially influenced by angiotensin I-converting enzyme (ACE) inhibitors
with distinct physicochemical properties. Therefore, the aim of this study was to
investigate how the membrane penetration of various ACE inhibitors depends on
their lipophilia. All diacid forms of ACE inhibitors are dissociated at a pH of
7.4 and scarcely extractable into octanol (extraction coefficient < 10%). In
contrast, the extraction coefficients of the parent substances showed marked
differences in the following order of increasing lipophilia: enalapril =
perindopril < captopril = ceranapril < ramipril < quinapril < HOE288 = zofenopril
< fosinopril < HOE065. For selected substances, the kinetics of diffusion through
a monolayer of cultured bovine aortic endothelium were determined. The diffusion
rates (expressed as half lives) of captopril (59.6 min), enalapril (53.4 min),
enalaprilat (50.8 min), ramipril (56.9 min) and ramiprilat (51.1 min) are similar
indicating: 1) that penetration is independent on lipophilia and 2) that
endothelium constitutes no specific barrier for the passage of ACE inhibitors
into the vessel wall.
PMID- 10669040
TI - Sensitization of the adenylyl cyclase system in cloned kappa-opioid receptor
transfected cells following sustained agonist treatment: A chimeric study using G
protein alpha(i)2/alpha(q) subunits.
AB - Chronic and/or sustained opioid treatment has been shown to result in development
of sensitization of the adenylyl cyclase (AC) system or cAMP overshoot. In this
study, we investigated the molecular mechanism responsible for sensitization of
the AC system using CHO cells co-expressing cloned kappa-opioid receptor and some
chimeric G protein alpha(i2)/alpha(q) subunits. In CHO cells co-expressing the
kappa-opioid receptor and pertussis toxin-insensitive chimeric alpha(i2)/alpha(q)
subunits with alpha(i2) residues Met244-Asn331, despite pretreatment with
pertussis toxin, acute treatment with the kappa-opioid-receptor-selective agonist
U69,593 suppressed forskolin-stimulated cAMP accumulation, while sustained
treatment with U69,593 (4 h) induced cAMP overshoot over the naive level by the
kappa-opioid-receptor-selective antagonist norbinaltorphimine (sensitization of
the AC system). On the other hand, in CHO cells co-expressing the kappa-opioid
receptor and pertussis toxin-insensitive chimeric alpha(i2)/alpha(q) subunits
without alpha(i2) residues Met244-Asn331, pretreatment with pertussis toxin
completely blocked these acute and sustained effects of U69,593 on cAMP
accumulation. These results suggested that the presence of the specific region of
alpha(i2) (Met244-Asn331), which was reported to be responsible for the
inhibition of AC, and continuous inhibition of AC by alpha(i2) is necessary for
the development of sensitization.
PMID- 10669041
TI - The role of endothelium-derived nitric oxide in relaxations to levcromakalim in
the rat aorta.
AB - The present study was designed to examine the role of basally released nitric
oxide in relaxations to an ATP-sensitive K+ channel opener. Whether relaxations
to levcromakalim are modulated by endothelial removal or the inhibitors of
vasodilator effects of endothelium-derived nitric oxide, were investigated in the
rat aorta. During contractions to phenylephrine (3 x 10(-7) to 10(-6) M),
levcromakalim (10(-8) to 10(-5) M) or a nitric oxide donor, 1-hydroxy-2-oxo-3-(N
methyl-3-aminopropyl)-3-methyl-1-triazene (NOC-7, 10(-9) to 10(-5) M), was added
in a cumulative fashion. Relaxations to levcromakalim (10(-8) to 10(-5) M) were
significantly reduced by the endothelium-removal. In aortas with endothelium,
relaxations in response to levcromakalim were decreased by selective inhibitors
of nitric oxide synthase (N(G)-nitro-L-arginine methyl ester, 10(-4) M) and
soluble guanylate cyclase (1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one; ODQ, 10(
5) M) and a scavenger of nitric oxide (carboxy-PTIO, 10(-3) M). Relaxations to
levcromakalim in aortas treated with these inhibitors are comparable to those
seen in aortas without endothelium. KCl (30 mM) and an ATP-sensitive K+ channel
inhibitor, glibenclamide (10(-5) M), abolished relaxations to levcromakalim in
aortas with or without endothelium, whereas glibenclamide did not alter
relaxations to NOC-7 (10(-9) to 10(-5) M) in aortas without endothelium. These
results suggest that in rat aortas, inhibition of vasodilator effects of basally
released nitric oxide can reduce relaxations via ATP-sensitive K+ channels,
although these channels do not mediate relaxations to exogenously applied nitric
oxide.
PMID- 10669042
TI - Involvement of brain serotonergic terminals in the antinociceptive action of
peripherally applied calcitonin.
AB - We investigated the antinociceptive effect of systemic injection of calcitonin
and its mechanisms of action in rats. Subcutaneous injection of [Asu(1,7)]eel
calcitonin (ECT, 4 U x kg(-1) x day(-1)) daily for 7 days suppressed nociceptive
hypersensitivity induced by formalin (and by carrageenan); the effect was
gradually increased by the repeated injections and significant effects were
observed after administration for more than 4 days. The antinociceptive action of
ECT (4 U x kg(-1) x day(-1) for 7 days) was inhibited by intracerebroventricular
injection of the serotonergic neurotoxin 5,7-dihydroxytryptamine and serotonin
receptor antagonists methiothepin, cyproheptadine and ketanserin; methysergide
showed an inhibitory tendency. Intrathecal injections of 5,7-dihydroxytryptamine,
methiothepin, cyproheptadine and ketanserin were without effects on the ECT
action. The results suggest the involvement of serotonin in the brain, but not in
the spinal cord, in the ECT antinociception. Intracerebroventricular or
intrathecal injection of the catecholaminergic neurotoxin 6-hydroxydopamine and
intracerebroventricular injection of the alpha-adrenoceptor antagonist
phentolamine were also without effects on the ECT action. A subcutaneous infusion
of the opioid receptor antagonist naloxone inhibited the antinociceptive action
of morphine, but not that of ECT. Thus, adrenergic and opioidergic systems may
not play important roles in the ECT antinociception. The present results suggest
that repeated systemic injection of ECT produces analgesia and that the brain
serotonergic terminals are involved in this action.
PMID- 10669043
TI - Endogenous ATP released by electrical field stimulation causes contraction via
P2x- and P2y-purinoceptors in the isolated tail artery of rats.
AB - Electrical field stimulation (EFS) caused contraction of isolated tail arteries
of rats. The EFS-induced contraction showed frequency-dependence and was entirely
abolished by the sodium channel blocker tetrodotoxin (1 x 10(-7) M). The EFS
induced (at 20 Hz) contraction was reduced by about 60% in the presence of
phentolamine (1 x 10(-6) M). Therefore, later experiments were carried out in the
presence of phentolamine. Pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid
(PPADS) (1 x 10(-8)-1 x 10(-6) M) and basilen blue E-3G (3 x 10(-5)-5 x 10(-5)
M), P2-receptor antagonists, significantly inhibited the contraction evoked by
EFS. In addition, PPADS significantly inhibited the contractions induced by ATP
(1 x 10(-4) M) and a selective P2x-receptor agonist, alpha,beta-methylene ATP (1
x 10(-6) M). In contrast, basilen blue E-3G did not inhibit alpha,beta-methylene
ATP-induced contraction. The ecto-ATPase activator apyrase (5 and 10 U/ml)
significantly reduced the EFS-induced contractions. These findings suggest that
endogenous ATP released by EFS causes contractions of rat tail artery via both
the P2x-receptors and P2y-receptors.
PMID- 10669044
TI - Effect of zaldaride maleate, an antidiarrheal compound, on visceral pain reflex
induced by small intestinal distention in anesthetized rats.
AB - Using distention of the small intestine as a visceral pain model, we investigated
the effect of zaldaride maleate (ZAL), a selective inhibitor of calmodulin, on
the depressor response. In pentobarbital-anesthetized rats, small intestine
distention was induced by rapid application of intraluminal pressures of 40 cmH2O
causing a reflex fall in arterial blood pressure. The depressor response to
intestinal distention was abolished by intraperitoneal administration of
capsaicin (5 mg/rat), which depletes neuropeptides such as substance P from the
sensory neurons, on the mesenteric stalk and by neonatal pretreatment with
capsaicin (50 mg/kg, s.c.). Morphine (20 mg/kg, s.c.) reduced the depressor
response following intestinal distention. At doses of 3 mg/kg (i.v.) and higher,
ZAL significantly reduced depressor response. The effect of morphine was reversed
by naloxone (5 mg/kg, i.v.); the effect of ZAL was not affected. These results
suggest that ZAL helps reduce the visceral pain induced by noxious stimulus and
that the antinociceptive effect of ZAL is not mediated by opioid receptors.
PMID- 10669045
TI - Structure and sequence of the mouse V1a and V1b vasopressin receptor genes.
AB - The structural organization and 5'-flanking region of the mouse V1a and V1b
vasopressin receptor genes were determined. The mouse V1a receptor gene was
located within an 8-kb XbaI fragment, and the mouse V1b receptor gene was located
within a 14-kb EcoRV fragment. Both genes were comprised of two coding exons that
were separated by a 2.3-kb and a 8.0-kb intron, respectively, located before the
respective seventh transmembrane domain of the receptor sequence. The
availability of these genes would allow us to study the functional role of V1a
and V1b receptors by disrupting the gene in mice.
PMID- 10669046
TI - Influence of chronic treatment with imipramine on mRNA levels in rat brain:
elevation of glyceraldehyde-3-phosphate dehydrogenase levels.
AB - The differential display method was used to identify the intrinsic factor that
changes its mRNA expression level in rat brain after a 14-day oral administration
of 20 mg/kg imipramine. The expression of a 180-bp band was markedly enhanced by
imipramine. The results of sequencing and a data base search revealed that the
isolated clone was glyceraldehyde-3-phosphate dehydrogenase (GAPDH) with a one
base difference. Enhancement of the expression by imipramine was observed in the
amygdala. Quantitative PCR showed that imipramine treatment significantly
elevated the GAPDH/beta-actin ratio in the cortex. These findings suggest that
long-term treatment with imipramine stimulates GAPDH mRNA expression.
PMID- 10669048
TI - Effect of benidipine on depolarizing stimulation-induced increase of
intracellular calcium concentration in cultured mouse hippocampal neurons.
AB - We examined the effect of benidipine, a 1,4-dihydropyridine calcium channel
blocker, on depolarizing stimulation-induced increases of intracellular calcium
concentration ([Ca2+]i) in cultured mouse hippocampal neurons in comparison with
those of nicardipine and nilvadipine. Benidipine (0.1-10 microM) inhibited the
[Ca2+]i increase compared with the no drug control response. This effect was
stronger than those of nicardipine and nilvadipine. The inhibitory effect of
benidipine lasted even after washing out the drug for 125 min, while those of
nicardipine and nilvadipine disappeared more rapidly. This is the first report
that demonstrates that benidipine inhibits the [Ca2+]i increase in the neuron
itself.
PMID- 10669047
TI - Antidiarrheal effects of zaldaride maleate after oral, intravenous and
subcutaneous administration to rats.
AB - The antidiarrheal action of zaldaride maleate (ZAL) after oral, intravenous and
subcutaneous administration was examined to determine whether ZAL acts
systemically or locally in the intestine of rats. Oral administration of ZAL
inhibited castor oil- and 16,16-dimethyl prostaglandin E2-induced diarrhea;
however, intravenous or subcutaneous administration of ZAL was ineffective. When
ZAL was orally administered, the area under the plasma concentration time curve
of the compound was lower than that of ZAL following intravenous or subcutaneous
administration at the maximum doses studied. The antidiarrheal effect of ZAL was
not dependent on its plasma concentration level. These results suggest that ZAL
acts locally in the intestinal tract in rats.
PMID- 10669049
TI - Inhibition of human chymase by suramin.
AB - Chymase is a chymotrypsin-like protease localized in mast cells in complexes with
heparin. In the present study, we demonstrated that suramin, a hexasulfonated
naphthylurea used as an anti-cancer drug, inhibits the activity of purified human
chymase in vitro. The inhibition was ionic-strength-dependent. It was observed
that suramin competed with heparin-Sepharose gel for binding to chymase and the
inhibition of chymase activity by suramin was partially impaired by heparin. Our
results show that suramin may become a prototype of a new type of chymase
inhibitor because of its unique character.
PMID- 10669050
TI - An approach to the medical marijuana controversy.
AB - The use of smoked marijuana as a therapeutic agent is presently a matter of
considerable debate in the United States. Many people suffering from a variety of
disorders maintain that it is necessary for their adequate treatment. Yet, the
evidence to support claims is insufficient for FDA approval. An interim solution
is proposed which would allow patients referred by their physicians to
participate in a 6-month program of legal marijuana availability, similar to the
'compassionate IND' program of a number of years ago. A technique similar to that
used for post-marketing surveillance is proposed for obtaining quantitative data
for a limited number of potential indications. These are: (1) nausea and vomiting
associated with cancer chemotherapy or other causes, (2) weight loss associated
with debilitating illnesses, (3) spasticity secondary to neurological diseases,
and (4) chronic pain syndromes.
PMID- 10669051
TI - A comprehensive guide to the application of contingency management procedures in
clinical settings.
AB - Controlled clinical research has demonstrated the efficacy of contingency
management procedures in treating substance use disorders. Now is the time to
begin introducing these procedures into standard clinical practice. This article
reviews the rationale of contingency management interventions and provides a
review of representative scientific work in the area. It also discusses behaviors
that can be modified, reinforcers that can be used, and behavioral principles
that can be adapted to improve outcomes. This paper provides practical advice and
a guideline for clinicians and researchers to use when designing and
administering contingency management interventions. The recommendations are based
on empirically validated manipulations. Areas in which more research is needed
are suggested as well.
PMID- 10669052
TI - Gender differences in hostility of opioid-dependent outpatients: role in early
treatment termination.
AB - The purpose of this study was to evaluate gender differences in hostility and the
role of hostility in predicting early treatment termination of opioid-dependent
outpatients. Demographic characteristics and Addiction Severity Index (ASI)
ratings were collected from 104 patients (68 males and 36 females) at intake to a
buprenorphine treatment program. Hostility was assessed using the Buss-Durkee
Hostility Scale. Compared to male opioid-dependent patients, females scored
significantly higher on this scale. Early treatment termination was defined as
remaining in treatment < 30 days, and 13% percent of males and 25% of females
were classified as early terminators. Stepwise logistic regression identified
predictors of early treatment termination. Severity of legal and employment
problems and the interaction between hostility and gender predicted early
treatment termination status. Patients with less severe legal problems and
patients with greater employment problems were more likely to terminate early
from treatment. Higher levels of hostility predicted early treatment termination
of female patients, but hostility levels were not associated with treatment
termination in male patients. Results from this study show that female heroin
addicts have high levels of hostility and suggest that hostility may be an
important predictor of premature discharge from opioid substitution programs,
especially among women.
PMID- 10669053
TI - Illicit cocaine use patterns in intravenous-naive cocaine users following
investigational intravenous cocaine administration.
AB - This study evaluated whether cocaine use patterns changed following
investigational intravenous cocaine administration to intravenous-naive cocaine
users. Subjects were respondents to a follow-up survey who had participated in
one to three intravenous double-blind cocaine (0.2 or 0.4 mg/kg) administration
studies. The group included healthy men (n = 17) and women (n = 8) with histories
of occasional cocaine use (lifetime self-reported use of 12+/-12 (mean +/- S.D.)
exposures, primarily via nasal insufflation) who were recontacted an average of
39 weeks (range 7-107 weeks) after study participation. The recontacted group
constituted 45% of the total eligible sample of 55 subjects. Baseline
demographics for the recontacted and non-recontacted (n = 30) samples were
similar, suggesting that the recontacted sample was representative of the group
as a whole. Investigational cocaine exposure did not induce adverse health events
in any subject. Self-reported cocaine use estimates obtained at follow-up were
compared to baseline estimates obtained with identical questionnaires and were
highly concordant (Spearman rank correlation p = 0.52 and 0.78, respectively; P <
0.02 and < 0.0002, respectively). This suggests that participants provided stable
and reliable reports of cocaine use. No subject reported either illicit
intravenous cocaine use or altered frequency of illicit cocaine use by the
customary route after investigational intravenous cocaine exposure. These data
suggest that illicit cocaine use frequencies and routes of administration are not
altered following investigational intravenous cocaine administration to healthy,
occasional cocaine users.
PMID- 10669054
TI - Predictors of expressed partner and non-partner violence among patients in
substance abuse treatment.
AB - This study examined reports of expressed partner and non-partner violence among
men (n = 126) and women (n = 126) in the 12 months prior to substance abuse
treatment. Rates of violence were 57% for partner, 53% for non-partner, and 75%
collapsing across partner and non-partner relationships. Factors associated with
partner and non-partner violence severity differed substantially. Partner
violence was predicted by age, marital status, and drug problem severity. Non
partner violence was predicted by gender, income, alcohol and drug problem
severity. The results highlight that individuals in substance abuse treatment are
at high risk for violence, and targeted screening and intervention approaches
should be routine in addictions treatment.
PMID- 10669055
TI - Contingency management in outpatient methadone treatment: a meta-analysis.
AB - A meta-analysis was conducted on contingency management interventions in
outpatient methadone treatment settings. The outcome measure of interest was drug
use during treatment, as detected through urinalysis. The results confirm that
contingency management is effective in reducing supplemental drug use for these
patients. The analysis of behavioral interventions yielded an overall effect size
(r) of 0.25 based on 30 studies. Significant moderators of outcomes included type
of reinforcement provided, time to reinforcement delivery, the drug targeted for
behavioral change, number of urine specimens collected per week, and type of
subject assignment. These factors represent important considerations for reducing
drug use during treatment.
PMID- 10669056
TI - Stress induced spontaneous recurrence of methamphetamine psychosis: the relation
between stressful experiences and sensitivity to stress.
AB - We examined increased sensitivity to stress in relation to spontaneous
recurrences of methamphetamine (MAP) psychosis (i.e., flashbacks). Plasma
monoamine metabolite levels were assayed in: 26 flashbackers, of whom 11 were on
neuroleptics before and during the study, and the other 15 received neuroleptics
in the course of the study; 18 non-flashbackers with a history of MAP psychosis;
eight subjects with persistent MAP psychosis; and 23 MAP user and 11 non-user
controls. The 26 flashbackers had experienced stressful events and/or MAP-induced
fear-related psychotic symptoms during previous MAP use. Mild psychosocial
stressors then triggered flashbacks. During flashbacks plasma norepinephrine
levels increased markedly; among the flashbackers, those with a history of
stressful events, whether or not they had experienced fear-related symptoms,
showed a further increase in 3-methoxytyramine levels. Stressful experiences,
together with MAP use, may therefore induce sensitization to stress associated
with noradrenergic hyperactivity, involving increased dopamine release, and so
triggering flashbacks.
PMID- 10669057
TI - The role of stimulated lipid peroxidation and impaired calcium sequestration in
the enhancement of cocaine induced hepatotoxicity by ethanol.
AB - The purpose of this study was to investigate possible mechanism of cocaine
induced hepatotoxicity and its potentiation by ethanol in mice. Ethanol (2 g/kg)
and/or cocaine (25 mg/kg) injections were given as binge model (five injections
in 3 days). Cocaine administration with or without ethanol caused an increase in
lipid peroxidation in liver homogenate and its subcellular fractions. The
greatest increases were observed in mitochondrial fraction following cocaine plus
ethanol treatment. Also, glutathione (GSH) levels were increased in liver
homogenate and its mitochondrial fractions after cocaine and cocaine plus ethanol
treatment. Microsomal calcium sequestration was found to decrease in all
treatments. These results suggest that increased lipid peroxidation and decreased
microsomal calcium sequestration in the liver may play a possible role cocaine
induced hepatotoxicity and its potentiation by ethanol.
PMID- 10669058
TI - Inpatient opiate detoxification in Geneva: follow-up at 1 and 6 months.
AB - The aim of this study was to identify predictors of treatment success and of
relapse, 1 and 6 months after inpatient opiate detoxification in an 8-bed unit in
Geneva. Of all 73 patients admitted between June 1994 and June 1995, a majority
(73%) successfully finished opiate detoxification. Detoxification was performed
mainly with methadone tapering; the average duration of hospitalisation was 15
days. Factors associated with treatment failure were: cocaine abuse, presence of
legal problems, and short duration of hospital stay. After 1 month, 65% of the
patients were using drugs (half of them were dependent again, half of them had
used occasionally) and 35% were completely abstinent (21% when excluding those in
residential treatment). Predictors of rapid relapse were cocaine abuse and little
concern with own psychological situation at baseline. After 6 months, 50% were
physically dependent again, 13% had lapsed occasionally, 37% were abstinent (28%
when excluding those in residential treatment). Only high benzodiazepine use at
baseline was associated with medium term abstinence. Addiction severity index
composite scores had considerably improved between baseline and 6 months.
Prevention of relapse to opiate use after inpatient detoxification, especially
for those with a concurrent cocaine abuse, should be improved.
PMID- 10669059
TI - Dissociation of physical abstinence signs from changes in extracellular dopamine
in the nucleus accumbens and in the prefrontal cortex of nicotine dependent rats.
AB - The aim of the present study was to investigate the relationship between physical
abstinence and changes in dopamine release in the nucleus accumbens and in the
medial prefrontal cortex induced by mecamylamine and naloxone in rats chronically
exposed to nicotine. The rats were implanted with osmotic minipumps (Alzet)
delivering nicotine tartrate at a rate of 9 mg/kg/day (3.16 mg of free base) and
8 days later with a dialysis probe in the nucleus accumbens or in the medial
prefrontal cortex. Steady-state dopamine output from the nucleus accumbens of the
rats implanted with nicotine minipumps was higher than that of sham implanted
rats; no differences were observed in the prefrontal cortex. In nicotine but not
in sham implanted rats mecamylamine (1 mg/kg s.c.) precipitated a physical
abstinence syndrome and brought dopamine output back to control values in the
nucleus accumbens. In contrast mecamylamine (1 mg/kg s.c.) increased dopamine
output in the medial prefrontal cortex of nicotine but not sham-implanted rats.
Naloxone (2 mg/kg) precipitated a physical abstinence syndrome qualitatively
similar to that produced by mecamylamine but failed to modify extracellular
dopamine in the nucleus accumbens or in the prefrontal cortex of nicotine
implanted and sham-implanted rats. The results indicate that the mesolimbic and
mesocortical dopamine system undergo opposite changes during mecamylamine
precipitated abstinence in rats chronically exposed to nicotine and that physical
abstinence signs can be dissociated from changes in dopamine transmission.
PMID- 10669060
TI - A within-subject comparison of three different schedules of reinforcement of drug
abstinence using cigarette smoking as an exemplar.
AB - In this experiment we compared three different schedules of reinforcement for
promoting and sustaining short-term drug abstinence. For pragmatic reasons,
cigarette smoking was studied as an exemplar of drug self-administration. The
three schedules studied were a fixed magnitude of reinforcement for abstinence, a
progressive increase in magnitude of reinforcement for abstinence with a reset
contingency for drug use, and a progressive increase in magnitude of
reinforcement for abstinence without a reset contingency. Eighteen cigarette
smokers experienced the three schedules in a counterbalanced order. Each schedule
was in effect for 5 consecutive days (M-F), during which time abstinence was
reinforced according to the different schedules of reinforcement. The total
amount of reinforcement (money) available was the same during each condition. The
progressive magnitude with a reset schedule was more effective than the other two
schedules in sustaining an initial period of abstinence. These results
systematically replicate and extend those from prior studies demonstrating the
efficacy of schedules incorporating a progressively increasing magnitude of
reinforcement with a reset contingency for sustaining initial drug abstinence,
and demonstrate the importance of the reset contingency to that effect.
PMID- 10669061
TI - Drug use, self report and urinalysis.
AB - Stimulated by the ever present demand to consider the financial implications in
management decisions, this study examines the use of urinalysis and self-report
in the treatment of drug users, to question if urinalysis, rather than being a
routine investigation, could be used with greater discrimination without
jeopardising its effectiveness. It concludes that urinalysis remains of
importance, as an adjunct to self-report, in providing information and in the
treatment of drug users. Suggestions are made as to how it might be used more
selectively in treatment based on a clinical knowledge of individual patients and
their progress in treatment. However further research is needed to support and
define this more clearly.
PMID- 10669062
TI - Methadone, methadone treatment and non-fatal overdose.
AB - This paper provides a mainly qualitative investigation of the role of methadone
and methadone treatment in non-fatal illicit drug overdose. During 1997 and 1998,
semi-structured interviews were conducted with 33 individuals in six hospital
accident and emergency departments in two Scottish cities. The research
identified four overdose situations related to methadone/methadone treatment.
These were: (1) topping up a legitimate methadone prescription; (2) abusing
another's methadone prescription; (3) preferring illegal drugs to prescribed
methadone; and (4) failing to obtain prescribed methadone. The implications of
these findings for methadone treatment policy and practice are discussed.
PMID- 10669063
TI - Effects of prolonged ethanol exposure on neurophysiological measures during an
associative learning paradigm.
AB - Long-term ethanol exposure has been reported to produce electrophysiological and
cognitive impairments in some alcoholics. This study assessed the effects of
chronic ethanol exposure on neurophysiological indices of associative learning in
rats. Male Wistar rats (46) were exposed to ethanol vapor (EtOH group) or air
(control group) for 6 consecutive weeks. After the animals were withdrawn from
ethanol, electrodes were implanted in the frontal and parietal cortices and in
the amygdala. Following a prolonged abstinence from ethanol (10-15 weeks), rats
were exposed to a classical conditioning paradigm in which a food pellet was
paired with the presentation of an auditory stimulus. During the first five
sessions (conditioning phase), food pellet presentation was paired with the
presentation of an infrequently presented tone. During the second five sessions
(extinction phase), the association between food pellet presentation and the
infrequently presented tone was weakened by no longer presenting food pellets
following the infrequent tone. During selected test sessions, event-related brain
potentials (ERPs) elicited by each tone (i.e. food-paired tone, non-paired tone)
were recorded and analyzed. These analyses revealed differences in ERP responses
between the groups. The latency of the N1 and P2 ERP components in the cortex of
the control group, but not the EtOH group, increased during sessions when the
association between food pellet delivery and tone presentation was being
established or extinguished. These data support the hypothesis that chronic
ethanol treatment results in a loss of responsivity in ERP components sensitive
to changes in food-tone associations, even following a prolonged period of
withdrawal from ethanol.
PMID- 10669064
TI - Estimates of total alcohol consumption in Russia, 1980-1994.
AB - It is important to estimate real alcohol consumption in Russia in the past 15
years because large quantities, and in recent years the bulk, of consumed alcohol
evades state registration. In this study, trends in total consumption are
estimated indirectly using an indicator of alcohol-related harm derived from
forensic reports on accidental and violent deaths (Nemtsov, A.V., 1998. Anti
alcohol campaign, consequences, and actual alcohol consumption in Moscow,
Addiction, in press). Using blood alcohol coefficients (BAC), the regression
coefficients are estimated using the ratio of BAC-positive and BAC-negative
accidental and violent deaths in 1983-1986 in connection with the Moscow anti
alcohol campaign; the coefficients are then used to estimate consumption as a
total sum of legal sales of alcoholic beverages and illegal spirits made from
sugar. Data were obtained of violent BAC-positive and BAC-negative deaths in 17
25 oblasts of Russia in 1981-1994. The derived estimates indicate that in 1984
consumption exceeded 14 l per capita, per annum (10.5 registered + 4.2
unregistered); that consumption fell to 10.8 1 in 1986 (during the anti-alcohol
campaign), and that it then began to rise owing to a sharp increase in estimated
unregistered alcohol consumption-climbing to 13.6 l (5.0 + 8.6) in 1993, and
followed by a slight decline to 13.3 in 1994. These estimates are broadly
consistent with estimates that have been made using unrelated methods, thus
allowing some confidence in the overall picture obtained. Russia probably remains
one of the heaviest-drinking countries in Europe. The reasons why indicators of
alcohol-related harm in the mid-1990s exceed those recorded before the anti
alcohol campaign remain to be clarified.
PMID- 10669065
TI - Efficacy of daily and alternate-day dosing regimens with the combination
buprenorphine-naloxone tablet.
AB - This study evaluated the efficacy of a combination tablet formulation of
buprenorphine containing 8 mg of buprenorphine and 2 mg of naloxone for every
other day treatment and whether increasing the daily maintenance dose was
essential for maintaining an efficacious alternate-day treatment. Twenty-six
opioid-dependent outpatients completing a 16-day baseline entered a double-blind,
placebo-controlled, triple crossover trial. Twenty-one days of daily combination
tablet administration were compared to two different 21-day periods of alternate
day buprenorphine administration where subjects received either 8 or 16 mg of the
combination tablet every other day with placebo on the interposed day. Fifty-four
percent (14/26) of subjects completed the study, but only two subjects dropped
out during the 16-mg alternate-day condition. Rates of medication compliance,
illicit opioid use and subject- and observer-rated measures of opioid effects did
not distinguish daily from alternate-day treatments in subjects completing the
study. However, pupillary diameter was significantly increased during 8-mg
alternate-day compared to the 8-mg daily or 16-mg alternate-day treatment. These
data replicate earlier findings describing the acceptability of alternate-day
buprenorphine treatment using multiples of the daily maintenance dose and extend
these findings by establishing the clinical efficacy of daily and alternate-day
dosing regimens with the combination buprenorphine naloxone tablet. This study
also suggests slightly improved outcomes during alternate-day treatment using
multiples of the daily dose.
PMID- 10669066
TI - HIV-1 RNA load in needles/syringes from shooting galleries in Miami: a
preliminary laboratory report.
AB - We quantified HIV-1 RNA load in rinses from needles/syringes (N/S) obtained at
shooting galleries in Miami and also analyzed the rinses for antibodies for viral
proteins. In rinses from 36 N/S that contained visible blood, 14 (39%) had
detectable amounts of HIV-1 RNA. Numbers of copies of HIV-1 RNA ranged from the
detection limit (400 copies/ml) to 268,000 copies/ml. We also detected antibodies
to HIV-1 polypeptides in 34/36 (94%) of rinses from visibly contaminated N/S
using Western blots specific for the HIV-1 proteins. No antibodies were detected
in laboratory rinses from six visibly clean needles. The presence of HIV-1 RNA in
N/S is an important indication of the risk created by N/S sharing as well as by
shared paraphernalia and wash waters by injecting drug users.
PMID- 10669067
TI - Reversibility of morphine effects on phagocytosis by murine macrophages.
AB - Proneness of addicts to infections may be partially due to opiate effects on
immune cells. We find that acute morphine inhibits phagocytosis in murine
peritoneal macrophages in vitro with apparent desensitization at high
concentrations, whereas chronic exposure results in a state akin to
tolerance/dependence where macrophages seem to require morphine to phagocytize at
a control level. However, both putative desensitization and tolerance/dependence
are reversible, since drug re-addition several hours after withdrawal results in
inhibition, as in acute exposure. This shows that opiate effects on immune cells
are variably related to the experimental context in which they are administered,
which is of relevance for understanding their potential role in
immunosuppression.
PMID- 10669068
TI - Reductions in acquisitive crime and drug use after treatment of addiction
problems: 1-year follow-up outcomes.
AB - The relationship between acquisitive crime and drug misuse problems was studied
among 753 clients recruited to the National Treatment Outcome Research Study
(NTORS). More than 17000 offences were reported during the 90-day period prior to
treatment. Half of the clients committed no acquisitive crimes during this period
whereas 10% committed 76% of the crimes. At 1-year follow-up, the number of
crimes was reduced to one third of intake levels, and criminal involvement was
reduced by about half. Reductions in regular heroin use were strongly associated
with reductions in crime. The reduction in crime following treatment is of great
importance and provides immediate benefit to society through the reduced economic
costs of crime.
PMID- 10669069
TI - The impact on retention of expansion of an Australian public methadone program.
AB - Although rapid expansion of methadone programs has occurred in many countries,
there are few studies of the impact on treatment success. The one public
methadone maintenance program in Canberra was expanded from 85 places in 1991 to
350 places in late 1992. While this responded to a real need, it also led to a
temporary increase in drop-outs. Retention was considerably improved in 1996 when
clients began to be transferred from the public program to fee-for-service
primary health care, but the improvement was also not sustained. In recent years,
one-quarter to one-half of clients dropped out before stabilization. Multiple
entries into treatment were common and overall retention was not affected by
previous treatment episodes or length of time between episodes. Methadone
programs should monitor retention as part of on-going evaluation and improvement
of treatment policy.
PMID- 10669070
TI - Substance use among high school students in Greece: outburst of illicit drug use
in a society under change.
AB - Trends in self-reported substance use in surveys of Greek adolescent students
show that regular tobacco smoking increased in 1998 (20.8%) after having fallen
between 1984 (22%) and 1993 (14.6%). Frequent alcohol consumption decreased in
1998 to 12.1%, from around 15% in both previous surveys. A sharp increase was
observed in illicit drug use from 6% in 1993 to 13.7% in 1998. Unprescribed use
of psychoactive medicines continued to decrease steadily from 53.8% in 1984 to
31.8% in 1998. Perceived availability and risks of cannabis parallel trends in
use. Policy measures and recent sociocultural changes seem to influence illicit
use.
PMID- 10669071
TI - A comparison of the harms associated with the injection of heroin and
amphetamines.
AB - An investigation into whether or not the level of harm associated with injecting
drug use varies depending on the drug that is injected was conducted among 151
primary heroin injectors and 145 primary amphetamine injectors. Compared to
primary amphetamine injectors, primary heroin injectors were more dependent on
their primary drug, had poorer social functioning, and had recently exhibited a
higher degree of criminal behaviour. There were no differences between the two
groups in terms of the prevalence of needle sharing, their health, or their
psychological functioning, despite the amphetamine users being significantly
younger and having used less frequently. It is concluded that while there are
some harms that are attributable to injecting per se, the type of drug that is
injected does play a mediating role in the relationship between injecting drug
use and its associated harm.
PMID- 10669072
TI - Illicit drugs and driving: prevalence, beliefs and accident involvement among a
cohort of current out-of-treatment drug users.
AB - Drug-driving behaviour among out-of-treatment dependent drug users has not been
investigated while a theoretical perspective on the propensity of certain drug
users to drive while impaired has not been suggested. This paper examines illicit
drugs and driving behaviour and accident involvement among out-of-treatment
current drug users. Psychological evidence of belief-based mechanisms to account
for the decision to drive while impaired by drugs are provided. A total of 210
out-of-treatment current drug users were interviewed in a non-clinical setting by
privileged access interviewers. Questionnaire measures were: current illicit drug
use, severity of dependence, illicit drugs and driving behaviour, impaired and
unimpaired accident involvement and beliefs and perceptions about the impairing
effects of a number of illicit drugs. Analyses are restricted to participants who
reported driving during the previous 12 months (n = 71). Fifty-eight participants
(81.7%) reported driving immediately after consuming illicit drugs, primarily
heroin and cannabis. Of these 41.4% (n = 24) had at least one road accident as a
driver, 15 of whom (62.4%) reported accident involvement following recent drug
consumption. Belief-based results showed that participants who reported never
driving after using illicit drugs perceived heroin, methadone and alcohol to be
greater significance for accident risk and driving skills impairment than other
drugs. Those drivers who reported drugs and driving behaviour believed only
alcohol to be significantly more impairing than other drugs. Findings indicated
that illicit drugs and driving behaviour is common among out-of-treatment drug
users. Accident involvement among this cohort is characterised by the previous
consumption of illicit substances. Differential beliefs about the effects of
drugs on driving performance and accident risk were shown to be dependent upon
frequency of drugs and driving behaviour. Results are discussed in terms of
experiential factors and consistency theories of attitude formation and change.
PMID- 10669073
TI - The brief abstinence test: voucher-based reinforcement of cocaine abstinence.
AB - This study assessed the effectiveness of a brief abstinence reinforcement
procedure for initiating cocaine abstinence in methadone maintenance patients. On
Monday of the test week, 72 cocaine-abusing methadone patients were offered a
$100 voucher if urine samples collected on Wednesday indicated that they had
abstained from cocaine across that 2-day period. A patient was considered
abstinent and the voucher delivered if the urine benzoylecgonine concentration
decreased by 50% from Monday to Wednesday (quantitative criterion) or if the
concentration of Wednesday's urine sample was < or = 300 ng/ml. Overall, 79% of
study patients showed urinalysis evidence of abstention from cocaine between
Monday and Wednesday of the test week. In a subsample with complete data (n =
50), significantly more patients abstained from cocaine from Monday to Wednesday
of the test week (84%) than from Monday to Wednesday of the week before (36%) or
after (32%) the test week. Furthermore, while almost all patients (94%) decreased
their benzoylecgonine concentration from Monday to Wednesday of the test week,
significantly fewer patients' benzoylecgonine concentrations decreased from
Monday to Wednesday of the week before (56%) or after (48%) the test week. This
highly efficacious procedure may have clinical application where reliable
abstinence initiation is desired, either on a temporary basis (e.g. sobriety
sampling) or at the start of longer-term interventions. It may also be possible
to use the brief abstinence test as an experimental model to assess the effects
of other therapeutic interventions on abstinence initiation in treatment
settings.
PMID- 10669074
TI - Ultrastructure of human dentine 40 years ago--progress and perspectives.
AB - In the 1959 premier issue of the Archives of Oral Biology, the first TEM
observations were presented of sections of undecalcified human mature dentine
produced with diamond knives. The odontoblast process was clearly shown to be a
cytoplasmic extension of the odontoblast. The peritubular dentine appeared to be
more calcified than the intertubular dentine and contained hydroxyapatite as
demonstrated by selective area electron diffraction. In the 40 years which
followed, significant progress was made in TEM methodology, including
improvements in fixation and embedding, development of ultrastructural
cytochemistry and immunocytochemistry, and the use of electron microscope
autoradiography. Additionally, we saw the advent of SEM and HRTEM. Thus, better
knowledge was gained of (1) the odontoblast and its process and the lamina
limitans, (2) the dentinal nerve fibrils and (3) the HRTEM aspects of dentine.
Interestingly, to the present day, diamond knives have continued to serve as the
best tool for preparing thin sections of non-decalcified mature hard tissue for
TEM and HRTEM, not only for dentine but also for bone, enamel and cementum.
PMID- 10669075
TI - Review of fluoride research since 1959.
AB - The evidence for the two main hypotheses proposed for the mode of action of F in
reducing caries is reviewed. The current conclusion is that low concentrations of
F in plaque, which need frequent renewal, favour remineralization of dental
tissue (i.e. a net reduction of demineralization) in the later stages of a
cariogenic episode. This replaces the other view that a high concentration of F
in the tooth mineral reduces its solubility.
PMID- 10669076
TI - Progress in oral biology research, 1959-1999. A review and update of Volume 1.
PMID- 10669077
TI - A comparison of four extraction methods for substance P, neurokinin A and
calcitonin gene-related peptide from human dental pulp tissue.
AB - Measuring neuropeptides in biological tissues by radioimmunoassay requires
efficient extraction that maintains their immunoreactivity. Many different
methods for extraction have been described, but there is little information on
optimal extraction methods for individual neuropeptides from human dental pulp
tissue. The aim was therefore to identify an effective extraction procedure for
three pulpal neuropeptides; substance P, neurokinin A and calcitonin gene-related
peptide. Tissue was obtained from 20 pulps taken from teeth freshly extracted for
orthodontic reasons. The pulp samples were divided into four equal groups and
different extraction methods were used for each group. Boiling whole pulp in
acetic acid gave the highest overall yield and, in addition, offered an easy and
rapid means of pulp tissue processing. The use of protease inhibitors did not
increase the recovery of the immunoreactive neuropeptides but did provide the
best combination of maximal recoveries and minimal variability. These results
should be useful for planning the extraction of these neuropeptides from human
pulp tissue in future studies.
PMID- 10669078
TI - Variations in human masseter and temporalis muscle activity related to food
texture during free and side-imposed mastication.
AB - Adjustments of mastication to food texture have been examined in various studies,
but the notion of food texture is often ill defined and usually assessed in terms
of hardness. The goal of this study was to examine the pattern of activity in
masseter and temporalis muscles during mastication of different food samples with
known textural properties and to determine the interindividual variability.
Electromyograms were recorded from the right and left masseter and temporalis
muscles in 36 young adults during 'free-style' and side-imposed mastication. Five
different types of food with known rheological properties were used. Both
temporalis and masseter activity increased with increased stress at maximum
strain of the chewed samples. A power function optimally described the relation
between muscle work per chew and the mechanical measurements of food; this
confirmed that the masticatory process is adjusted to accommodate to food
texture. Temporalis muscle activity was more influenced by food texture than was
masseter muscle activity. Less muscle work was needed to prepare the food bolus
for swallowing during free-style mastication. However, 25% of the participants
showed no differences between unilateral side-imposed mastication and 'free
style', suggesting that they might have greater chewing efficiency on one side.
PMID- 10669079
TI - Effects of dietary consistency and water content on parotid amylase secretion and
gastric starch digestion in rats.
AB - The aim was to estimate the significance of oral sensation and mastication in
inducing amylase secretion from the parotid gland and subsequent starch digestion
in the stomach. Rats were fed three diets of similar chemical composition but
different physical presentations. Two were solid, either pellets or powder, and
one was liquid. Oral sensory activity would be greatest with the pellets and
least with the liquid. Only the pellets would require significant mastication.
Three criteria were used to estimate amylase secretion, amylase activity in the
stomach, the depletion of glandular amylase activity and plasma amylase
concentrations. Gastric starch digestion was estimated by measuring the
concentration of reducing-sugars in the stomach contents. Parotid amylase
secretion and gastric starch digestion were similar whether rats were fed
pelleted or powdered solid food but much lower in rats fed a liquid diet. These
findings support the view that it is the contact of dry food with the oral mucosa
rather than the jaw movements involved in mastication that stimulates parotid
amylase secretion.
PMID- 10669080
TI - Viscoelastic properties of canine temporomandibular joint disc in compressive
load-relaxation.
AB - The present study was designed to investigate the mechanical properties and load
relaxation of these discs in compression. Eight discs were used for the
experiments. Compression was applied to specimens up to the specified strain, and
a series of load-relaxation tests was conducted on each specimen from 0.25%
strain to 2.0% strain with 0.25% intervals. The load-relaxation was monitored
over a period of 2 min. The elastic moduli of the canine articular discs were
30.9 and 15.8 MPa at t = 0 and 120 sec, respectively, and the discs exhibited
near-linear elastic characteristics at each time within a 2-min period. At all
strains, the time-dependent load-relaxation curves showed that the load decreased
markedly for the initial 30 sec, after which it levelled off after 120 sec with a
steady nonzero level. This relaxation feature can be well represented by Kelvin's
model. It is concluded that the canine temporomandibular joint disc can be
represented as a linear viscoelastic material, and that it plays an important
part as a stress absorber under compression.
PMID- 10669081
TI - Localization of plasminogen activators and plasminogen-activator inhibitors in
human gingival tissues demonstrated by immunohistochemistry and in situ
hybridization.
AB - The plasminogen-activating system plays an important part in tissue proteolysis
in physiological as well as pathological processes. Plasminogen activators u-PA
(urokinase) and t-PA (tissue) as well as the inhibitors PAI-1 and PAI-2 are
present in gingival crevicular fluid in concentrations significantly greater than
in plasma. This fact, and the finding that the concentrations of t-PA and PAI-2
are higher in areas with gingival inflammation, indicate local production of
these components. The present study describes, by means of in situ hybridization
and immunohistochemistry, the localization of the plasminogen activators and
their inhibitors in gingival tissues from patients undergoing periodontal
surgery. t-PA mRNA and t-PA antigen were primarily found in the epithelial
tissues, predominantly in the sulcular and junctional regions, although
occasionally in the oral epithelium and in blood vessels of the connective
tissue. u-PA and u-PA-receptor signals were seen in single cells within the
junctional and sulcular epithelia and adjacent to blood vessels close to the
junctional epithelium, but rarely in the oral epithelium. Similar to t-PA, the
predominant location of PAI-2 mRNA was the gingival epithelia. In the junctional
and sulcular epithelia, PAI-2 mRNA was seen throughout the thickness, while in
the oral epithelium the strongest signals were seen in stratum granulosum and
stratum spinosum. PAI-1 mRNA was invariably found in the connective tissue
associated with blood vessels. The present study confirms earlier indications of
local production of plasminogen activators and their inhibitors in gingival
tissues. In addition, the results demonstrate that t-PA and PAI-2 in these
patients are produced predominantly in the epithelial tissues. Furthermore, the
presence of t-PA and PAI-2 seems to be most pronounced in the areas likely to be
subjected to bacterial assault.
PMID- 10669082
TI - Innervation and myoepithelial arrangements in the submandibular salivary gland of
ferret investigated by enzyme, catecholamine and filament histochemistry.
AB - Although the submandibular gland of ferret is useful for studying salivary
secretory processes which are regulated by nerves and involve myoepithelial
activity, little attention has been paid to its parenchymal innervation and
myoepithelial arrangements. Therefore, glands obtained postmortem from mature
ferrets of both sexes were here examined with the use of light-microscopic
histochemical techniques for cholinesterases, phosphatases and phosphorylase,
histofluorescence for catecholamines, and milling dyes. Acetylcholinesterase
staining was associated with nerve trunks in the interlobular stroma and an
extensive intralobular network of nerve fibres, presumably of a cholinergic type,
embracing acini and ducts. There were fewer fibres containing fluorescing
catecholamines, presumably adrenergic. They were largely associated with acini.
Numerous stellate cells with fine branching processes embracing acini, presumably
myoepithelial cells, and a few spindle-shaped basal cells, investing striated
ducts, were demonstrated on frozen tissue by alkaline phosphatase, but not by
adenosine triphosphatase, inosine diphosphatase and phosphorylase. Cells of
similar shape and distribution were also demonstrated by staining with milling
dyes on fixed tissues, indicating possibly a filamentous constituent conferring
mechanical stability and/or contractile ability. Together, these results suggest,
firstly, that a cholinergic-type parenchymal innervation is prominent in the
submandibular gland of ferret, although many adrenergic nerves are also present,
and, secondly that the gland has a very extensive myoepithelial network which is
possibly involved in membrane transport, and the support and or contraction of
the secretory parenchyma.
PMID- 10669083
TI - T-cell antigen specificity in humans following stimulation with Porphyromonas
gingivalis.
AB - The effects of Porphyromonas gingivalis stimulation on T-cell clonality and
cytokine mRNA expression in peripheral blood mononuclear cells from individuals
with gingivitis and periodontitis were investigated. Clonality of T cells was
investigated by reverse transcription-polymerase chain reaction (RT-PCR) and
single-strand conformation polymorphism analysis. Cytokine mRNA expression was
investigated by RT-PCR. Whereas unstimulated mononuclear cells did not
demonstrate obvious clonality, clonal expansion was found in most Vbeta families
after stimulation. However, there was no relation between clonal change and
disease category or the presence of P. gingivalis infection. Messenger RNA for
interferon-gamma and interleukin-13 was upregulated whereas interleukin-4 and -10
were downregulated following P. gingivalis stimulation. Interleukin-12p35
demonstrated no consistent pattern. This study supports the concept that P.
gingivalis stimulates T cells in an antigen-specific fashion. It further suggests
that peripheral blood T cells may preferentially produce interferon-gamma and
interleukin-13 in response to P. gingivalis stimulation irrespective of disease
or P. gingivalis status.
PMID- 10669084
TI - Inhibition of rat parotid ecto-ATPase activity.
AB - The inhibitory profile of several known and suspected ecto-ATPase inhibitors was
compared on ecto-ATPase activity in rat parotid plasma membranes. Those chemicals
with high IC50 (above 130 microM) were the nucleotides alpha,beta-methylene ATP,
beta,gamma-methylene ATP, 2-methylthio ATP, inosine triphosphate, 5'-p
fluorosulphonylbenzoyladenosine, the sulphonates, 1-amino-2-naphthol-4-sulphonic
acid, Coomassie brilliant blue G, and the stilbene disulphonates, DIDS and SITS.
Those agents with low IC50 were: Coomassie brilliant blue R (114 microM),
ATPgammaS (49 microM), suramin (72 microM) and Reactive blue 2 (28 microM). The
last three inhibitors have similar potencies as inhibitors of ATP hydrolysis by
whole parotid acinar cells. ARL67156, a selective inhibitor of ecto-ATPase, had
an IC50 of approx. 120 microM. Suramin displayed non-competitive inhibition of
ecto-ATPase whereas the inhibitory effects of ATPgammaS and Reactive blue 2 were
curvilinear on Dixon plots. These results define the effects of various agents on
ecto-ATPase in an exocrine tissue that has been shown to respond to extracellular
ATP.
PMID- 10669085
TI - Tenacious adhesion of Actinobacillus actinomycetemcomitans strain CU1000 to
salivary-coated hydroxyapatite.
AB - Adherence of Actinobacillus actinomycetemcomitans to hard-tissue surfaces was
evaluated by comparing a phenotypically stable, well-maintained clinical isolate
(strain CU1000) to Streptococcus gordonii G9B, an extensively studied oral
colonizing bacterium. Standard innocula of radiolabelled bacteria were added to
saliva-coated hydroxyapatite (SHA) and the ratio of bound to unbound cells
counted. Several other clinical isolates as well as laboratory strain Y4 were
studied. In other experiments, cell detachment from SHA was compared in static
and shaking vessels to calculate controlled desorption of cells over time. A
sonic-displacement assay was used to measure avidity of binding to HA and SHA. To
better define the attachment properties of CU1000, bacteria were treated with a
variety of agents including detergents, salts and enzymes before or after
incubation with SHA. Results indicated that CU1000 bound better than G9B (a
minimum of 10-fold greater; p < or = 0.05) and did not desorb from SHA, while G9B
desorbed to equilibrium in 4 h. Furthermore, Langmuir isotherm calculations
indicated that, unlike G9B, CU1000 did not follow second-order adsorption
kinetics and thus did not achieve saturation. In addition, of the agents tested
only periodate reduced attachment and resulted in detachment of CU1000 from
surfaces. These experiments suggest that clinical isolates of A.
actinomycetemcomitans possess unique binding properties that promote adsorption
to and impede desorption from SHA. The characteristics described for the
actinobacillus in this study have been previously underestimated, appear to be
mediated by glycoconjugates, and may resemble attachment described for several
biofilm-forming, non-oral pathogens.
PMID- 10669086
TI - The craniofacial complex in 45,X/46,XX females.
AB - Fourteen Finnish 45,X/46,XX females were compared with population female and male
controls, and in addition, nine of them were compared with their first-degree
female relatives. Linear and angular measurements were made from standardized
lateral cephalograms of patients and normal population controls from the
"Kvantti" study series. In both comparisons the results indicated that
craniofacial dimensions in 45,X/46,XX females were smaller than those in
population female and male controls. The general metric pattern was similar to
that observed in relation to the tooth crowns of 45,X/46,XX females. Several of
their craniofacial proportions and plane angles differed from those of normal
women: shorter anterior and posterior cranial bases and a flatter cranial-base
angle, a sagittally shorter maxilla and a sagittally shorter mandible with an
enlarged ramus:corpus length ratio, posterior rotation of the mandible and a
tendency to bimaxillary retrusion. It is suggested that the reduction of X
chromosomal genetic material in 45,X/46,XX females results in smaller
craniofacial dimensions than in normal females, with substantial effects on
dimensional ratios and especially plane angles of the cranial base.
PMID- 10669087
TI - The buffer capacity and buffer systems of human whole saliva measured without
loss of CO2.
AB - The buffer capacity of unstimulated (UWS) and stimulated (SWS) whole-mouth saliva
involves three major buffer systems. The aim was to determine the buffer capacity
of UWS and SWS at specific pH in the interval from pH 7.5 down to pH 3.0. The
contribution of each of the buffer systems was also determined under conditions
resembling those in the mouth. UWS and SWS were collected from 20 healthy
volunteers; the saliva was collected under paraffin oil in order to avoid loss of
CO2. The buffer capacity of UWS and SWS in samples with and without bicarbonate
(HCO3-) and CO2 were measured at various pH by acid titration in a closed system
at 36 C. The mean concentrations of the buffer systems in UWS (mean flow rate
0.55 ml/min) were 4.4 mmol/l HCO3-, 4.5 mmol/l phosphate (of which 1.3 mmol/l was
present in the form of HPO4(2-)), 1876 microg/ml protein; the saliva pH was 6.8
and the P(CO2) 29.3 mmHg. The corresponding mean concentrations in SWS (mean flow
rate 1.66 ml/min) were 9.7 mmol/l HCO3-, 3.8 mmol/l phosphate (of which 1.9
mmol/l was present in the form of HPO4(2-)), 1955 microg/ml protein; pH 7.2 and
P(CO2) 25.7 mmHg, The highest buffer capacity of UWS and SWS was 6.0 and 8.5 mmol
H+ /(1 saliva*pH unit) at pH 6.25, respectively. At saliva pH in the range from
pH 7 down to pH 5, the following had significant impact on buffer capacity: the
HCO3- concentration (p < 0.001), the flow rate (p < 0.01), and the pH of the
saliva (p < 0.05). At acidic pH in the range from pH 5 down to pH 4, however,
only the protein concentration had a significant impact on buffer capacity (p <
0.01).
PMID- 10669088
TI - Age-related changes in the D-aspartic acid content of the teeth of the senescence
accelerated mouse.
AB - It is known that D-aspartic acid increases with age in dentine. Here, age-related
changes in the D to L-aspartic acid (D/L) ratios of the lower teeth of two
different sublines of the senescence-accelerated mouse (SAM), SAMP2/Iw (SAM,
prone 2/Iwate) and SAMR1/Iw (SAM, resistant 1/Iwate) were measured by gas
chromatography. The D/L ratio of the molars increased with advancing age, whereas
that of the incisors did not. In mice younger than 6 months of age the D/L ratio
of the molars from SAMP2/Iw tended to be higher than that from SAMR1/Iw, whereas
the converse applied to older mice. Racemization in the molars occurred
significantly faster in SAMR1/Iw than SAMP2/Iw (p = 0.01-0.001). Analysis
according to the kind of tooth showed that the D/L ratio increased gradually in
the order incisors < third molars < second molars < first molars, indicating that
the ratio was higher the earlier the molars formed. As racemization depends upon
the environmental temperature, the rectal temperatures of the mice were also
examined. The rectal temperature of SAMP2/Iw was highest when they were 2 months
old, but declined rapidly thereafter, whereas the rectal temperature of SAMRI/Iw
was highest when they were 6 months old, after which it declined gradually. These
results indicate that the D-aspartic acid contents of the molars of SAMR1/Iw and
SAMP2/Iw increase with age in a different fashion and suggest that the fashion
was determined by the body temperature, but not by the senescence-accelerated
age.
PMID- 10669089
TI - Thrombospondin-2 gene expression and protein localization during embryonic mouse
palate development.
AB - The mammalian palate develops from projections of the paired maxillary processes
termed palatal shelves. Shelf growth is an essential in normal palatal
morphogenesis. Mesenchymal proliferation in the palatal shelves is modulated by
transforming growth factor-1 (TGF-1), among other growth factors. Several
pathways effect TGF-beta activation, including one which utilizes thrombospondin
(TSP). TSP-1 is a major activator of TGF-beta in vivo and has been localized in
head mesenchyme, including palates. TSP-2 appears to inhibit TSP-1 activation of
latent TGF-beta by competitively binding the latent TGF-beta. Here the TSP-2 mRNA
transcript and the immunolocalization of TSP-2 protein with progressive
palatogenesis were quantified. There was a significant (p < 0.05) decline of TSP
2 transcript with palatal maturation; there was no evidence correlating the TSP-2
transcription with the amount of activated TGF-beta. At the vertical shelf stage
of palatogenesis, TSP-2 protein was found throughout the extracellular matrix of
shelf mesenchyme. By the horizontal shelf stage, TSP-2 protein was principally
localized to the ossification centres of the developing maxilla, both in
extracellular matrix and bone; far less was seen in palatal shelves proper. These
results suggest that TSP-2 is multifunctional during embryonic palate formation.
PMID- 10669090
TI - Development of multi-species consortia biofilms of oral bacteria as an enamel and
root caries model system.
AB - The aim was to establish defined-species consortium plaque biofilms to
investigate enamel and root caries in an artificial mouth. Strains of the
putative enamel and root caries pathogens, Streptococcus mutans, Strep. sobrinus,
Actinomyces naeslundii and Lactobacillus rhamnosus, were screened in batch
culture for potential cariogenic properties: a low terminal pH, ability to
aggregate, and catabolic diversity. The strains selected were grown as
monoculture biofilms and as consortium plaque biofilms in a multiplaque
artificial mouth. The biofilms were supplied with a constant flow of a simulated
oral fluid and were given periodic sucrose (and in some instances glucose) to
simulate meals. All the bacteria except L. rhamnosus formed large, monospecies
biofilms with resting pH in the range 5.3-5.8. The consortia biofilms were larger
and had a resting pH of 4.9-5.3. The consortia biofilms supplied with 8-hourly
carbohydrate comprised mainly 'mutans' streptococci (58, SD 5.5%) and L.
rhamnosus (42, SD 5.7%). A. naeslundii characteristically was absent or present
in a low percentage (up to 4% colony-forming units). All biofilms demineralized
polished bovine enamel and dentine blocks, as assessed by microradiography and
enamel-surface microhardness measurement. The consortia also demineralized intact
enamel and tooth roots; they were more cariogenic to enamel than any of the
monoculture biofilms, as measured by enamel-surface softening, but variation in
lesion depth was proportional to biofilm wet weight irrespective of acidogen
composition (r = 0.93, p < 0.05). Enamel lesions had a well-mineralized intact
surface and a zone of subsurface demineralization, typical of early natural
lesions. Dentine and root lesions showed extensive demineralization but lacked a
pronounced surface mineralized zone. Substitution of glucose for sucrose had no
effect on the cariogenicity of the consortium to bovine enamel or human roots and
had no major effect on the plaque composition. Continuously supplied fluoride (19
parts/10(6)) resulted in a substantially reduced enamel surface softening and
subsurface demineralization of intact roots. It was concluded that consortia
biofilms of selected caries pathogens generate realistic caries lesions in all
tooth hard tissues under controlled growth conditions in the artificial mouth.
This in vitro caries experimental model may prove useful for the study of
interrelations between the plaque biofilm, tooth tissues and the oral
environment, and for the development of procedures to modify the course of caries
development.
PMID- 10669091
TI - The molecular cloning, nucleotide sequence and expression of an antigenic
determinant from Porphyromonas gingivalis.
AB - A genomic library generated in Escherichia coli was probed with a monoclonal
antibody (mAb) LDS28, which reacts with a species-specific cell-surface antigen
of Porphyromonas gingivalis. A clone designated pGPR2.1 was shown to express a 46
kDa protein reactive with mAb LDS28, which maps to a 1.7-kb HincII fragment. DNA
sequence analysis revealed pGPR2.1 contains a 5653-bp insert with six open
reading frames, one of which shows significant DNA homology with the rnhB gene of
E. coli. Several subclones of pGPR2.1 were randomly generated in plasmid vector
pTTQ18* using restriction enzyme Sau3a. Immunoblotting of subclones demonstrated
that the LDS28-reactive antigen was coded for by an open reading frame predicted
to specify a protein of 455 amino acids (50 kDa). This open reading frame was
designated pgaA (Porphyromonas gingivalis antigen). The predicted amino acid
sequence of PgaA contains a putative ABC signature for binding NTPs as well as a
predicted transmembrane domain. Minicell labelling of pGPR2.1-encoded proteins
and subclone derivatives revealed that pgaA directs expression of protein of
multiple molecular weights (31-46 kDa) from its own promoter in E. coli, and that
some of these forms may be caused by proteolysis of a 50-kDa precursor which
itself shows a reduced apparent molecular weight (46 kDa) on sodium dodecyl
sulphate-polyacrylamide gel electrophoresis.
PMID- 10669092
TI - Increased blood flow and nerve firing in the cat canine tooth in response to
stimulation of the second premolar pulp.
AB - Mustard oil or mechanical stimulation was applied to maxillary second premolar
tooth pulps and pulpal blood flow and or intradental nerve activity in the
ipsilateral canine tooth were recorded in the cat. Mustard oil application to the
second premolar pulp significantly increased blood flow in the canine tooth pulp
to 162.0+/-65.8% (n = 16) of the prestimulation flow compared to control data
obtained with application of mineral oil (107.0+/-5.1%, n = 6) (Mann-Whitney U
test, p = 0.0009). Sectioning of the infraorbital nerve and its branches on the
experimental side (n = 4) did not affect this increase in pulpal blood flow. The
paraperiosteal injection of 2% lidocaine (1.0 ml) without vasoconstrictor
significantly inhibited the increase in canine pulpal blood flow induced by
mustard oil application to the second premolar pulp (109.8+/-6.8% of the
prestimulation level, n = 7) (Mann-Whitney U-test, p = 0.0013). Sporadic firing
or sometimes bursts of action potentials in the canine pulp nerves were recorded
during and/or after the mustard oil application to the second premolar pulp in
three of 16 cases. Four single pulp nerve units firing in synchrony with the
mechanical stimulation of the second premolar pulp were recorded in two of eight
canines, which substantiated the existence of branched afferents innervating both
teeth. These findings suggest that stimulation of the second premolar pulp may
induce axon reflex-related vasodilation and intradental nerve firing in the
canine pulp via branched afferent fibres innervating both the second premolar and
canine teeth.
PMID- 10669093
TI - Expression of cathepsin K mRNA during experimental tooth movement in rat as
revealed by in situ hybridization.
AB - The expression of cathepsin K. a novel collagenolytic enzyme specifically
expressed in osteoclasts, was investigated in the rat maxillary dentoalveolar
unit during experimental tooth movement by in situ hybridization histochemistry
with a non-radioisotopic cRNA probe for rat cathepsin K. Orthodontic elastics
were inserted into the interproximal space between the maxillary first and second
molars of 7-week-old male SD rats according to Waldo's method and sections
prepared from tissues obtained at 12 hr, 1, 2, 3, 4, 7, and 12 days after
orthodontic force application. Cathepsin K mRNA expression was detected in the
mono- and multinuclear osteoclasts on the pressure side of the alveolar bone at
12 hr after force application, and the distribution and number of cathepsin K
mRNA-positive osteoclasts increased time-dependently on the pressure side. At 3-4
days, a marked increase in cathepsin K mRNA-positive osteoclasts was found not
only on the pressure side but also on the tension side of the alveolar bone in
response to tooth movement. At 7-12 days, the cathepsin K mRNA-positive
osteoclasts on both sides had disappeared. These findings suggest that the
recruitment of osteoclasts on the pressure side begins during the initial stage
of orthodontic tooth movement and the site-specific early induction of cathepsin
K mRNA may cause an imbalance in the relative resorption activities on the
pressure and tension side incident to such movement.
PMID- 10669094
TI - Expression of myogenic regulatory factors during the development of mouse tongue
striated muscle.
AB - While the role of myogenic regulatory factors (MRFs) in skeletal myogenesis has
been well evaluated in limb and trunk muscles, very little is known about their
role in tongue myogenesis. Here the expression of MRF mRNA in mouse tongue muscle
was examined during development from embryonic day (E)11 to birth and compared
them with that in hind-limb muscle. Desmin, muscle creatine kinase and troponin C
mRNAs were used as markers for myoblast determination, myotubule formation and
myofibre maturation, respectively. The mRNA quantities were determined by
competitive reverse transcriptase-polymerase chain reaction. The expression
profile of desmin mRNA indicated that myoblast determination occurred before E11
in both the tongue and hind-limb muscles; the profile of muscle creatine kinase
and troponin C mRNAs indicated that myotubule formation and myofibre maturation
began between E11 and 13 in both tongue and hind-limb muscles, but ended 2 days
earlier in the tongue than in the hind limb. Expression of myoD and myogenin
mRNAs began at E11, increased, and showed peak values earlier in the tongue
muscle (E13) than in the hind-limb muscle (E15). Expression of MRF4 mRNA appeared
earlier in the tongue (E13) than in the hind-limb muscle (E15) and increased in
both muscles after that. These results suggest that myotubule formation and
myofibre maturation in the tongue muscle progress faster than in the hind-limb
muscle, a result of earlier expression of myoD, myogenin, and MRF4 in response to
earlier functional demands such as suckling immediately after birth.
PMID- 10669095
TI - Mutational analysis of X-linked amelogenesis imperfecta in multiple families.
AB - Seven mutations in the amelogenin gene are associated with X-linked amelogenesis
imperfecta. These mutations can produce reductions in the amount of enamel and
the degree of mineralization. Two families have been identified from western
North Carolina exhibiting features of amelogenesis imperfecta, characterized by
brown enamel in affected males and interposed vertical bands of normal appearing
and brown enamel in presumably heterozygous females. Mutational analysis reveals
a C-A mutation in exon 6 at codon 41 of the X-chromosomal amelogenin gene,
resulting in a pro-thr change in all individuals having the amelogenesis
imperfecta phenotype. This mutation was previously reported in a family with X
linked hypomaturation amelogenesis imperfecta. There is no known relationship
between any of the three families but the presence of similar phenotypes and
common mutations suggests they may be distantly related. For individuals from all
three families, the haplotype for six highly polymorphic loci flanking the
amelogenin gene was determined. A common haplotype was demonstrated among two of
the three families, suggesting that the mutation may have been inherited from a
common ancestor. The finding that the third family had a distinct haplotype may
indicate that the C-A mutation at codon 41 represents a mutational hotspot that
occurs with greater frequency than other known amelogenin gene mutations. The
phenotype resulting from this mutation was highly consistent in affected male
members of the same family and between families.
PMID- 10669096
TI - The Twirler mouse, a model for the study of cleft lip and palate.
AB - Twirler (Tw) is a semidominant mutation in the mouse affecting the embryonic
development of the midfacial region. Most heterozygous Tw mice, +/-, become obese
at adulthood with a concomitant decrease in fertility. Homozygous mice have
clefts of the midfacial region and a disrupted nasal cavity. Midfacial clefts
included clefts of the palate combined with either unilateral or bilateral clefts
of the lip. The clefts of the lip were either complete or incomplete. The palatal
shelves in Tw/Tw were very much reduced. Apart from these defects, homozygous Tw
looked normal, and were born alive, although they reportedly die within 24 h
after birth. It is proposed that the Twirler model can be used to improve
understanding of the genetic mechanisms involved in the normal development of the
midfacial region.
PMID- 10669097
TI - Cryptosporidiosis in birds--a review.
AB - The morphology, life cycle, maintenance, host specificity, incidence of
Cryptosporidium species infecting birds, as well as the epidemiology, clinical
signs, pathology, immunology, diagnosis, therapy, and control of avian
cryptosporidiosis are reviewed. Based on the accepted criteria used for
differentiation of Cryptosporidium isolates into valid species, this review
places the validity of C. meleagridis in doubt and suggests that C. meleagridis
isolated from birds is very closely related to, or identical with C. parvum
infecting more than 100 species of mammals.
PMID- 10669098
TI - Rate of infection and of reinfection by Echinococcus granulosus in rural dogs of
the province of Rio Negro, Argentina.
AB - Hydatidosis (cystic echinococcosis) constitutes a serious public health problem
in the Province of Rio Negro, Argentina. In the present work it was intended to
evaluate the prevalence of the canine echinococcosis in rural areas of the
Province of Rio Negro and studied the reinfection rate in dogs after treatment
with Praziquantel during the period 1980-1997. A total of 496 dogs were studied
in 18 canine concentrations in order to establish the initial prevalence rate
which was 42.3%. From 1980 onward dogs should have been systematically treated
with anthelmintic every 2 months in rural areas and every 6 months in urban
areas. We estimated that approximately 65% of dogs were treated. To determine the
reinfection rate, 476 dogs (1984) and 598 dogs (1996) were studied after
anthelmintic treatment during two sequential time periods (0-45; 46-90 days). In
both cases treated animals were compared with untreated dogs. Prevalences were
3.5%, 6.7% and 21.3% in 1984 and 0.8%, 4.0% and 10.0% in 1996. For the purpose of
surveillance a total number of 21,444 dogs were studied during 18 years.
Prevalence of Echinococcus granulosus decreased significantly in the first year
from 42.3% to 6.1%.
PMID- 10669099
TI - Dynamics of the humoral immune response of calves infected and re-infected with
Cooperia punctata.
AB - The dynamics of the humoral immune response of calves were analysed after primary
infection and re-infection with the intestinal nematode Cooperia punctata. 12
male 5 month-old Holstein-Friesian calves were randomly divided into two groups A
and B. At the beginning of the experiment Group A animals were each infected
experimentally with a single oral dose of 130,000 infective third stage larvae
(L3) of C. punctata. The animals of Group B were kept as non-infected controls.
The two calves from Group A with the highest infections died of cooperiosis at 32
and 44 days after infection (DAI), respectively. On DAI 100 the calves were
treated with the recommended dose of oxfendazole. On DAI 180 the remaining four
calves of Group A and three animals of Group B (B1) were infected with 260,000 L3
of C. punctata, while the other three calves of Group B (B2) served as non
infected controls. Monitoring of the humoral immune response predominantly
demonstrated an IgG1 response against both adult and L3 antigen of C. punctata.
Moreover, re-infections increased the levels of these immunoglobulins. IgA levels
were less increased than IgG1 and no significant increase was observed in IgG2
and IgM levels. Immunoblotting analysis showed that total IgG present in the
serum of the primary infected animals mainly reacted against adult proteins of 12
14 and 17-20 kDa and against L3 proteins of 33 and 43 kDa. After re-infection
total IgG reacted with the same adult proteins but also with an adult 29 kDa
protein.
PMID- 10669100
TI - Establishment and characterization of an Oklahoma isolate of Anaplasma marginale
in cultured Ixodes scapularis cells.
AB - Anaplasma marginale is a tick-borne hemoparasite of cattle worldwide. The
Virginia isolate of A. marginale was propagated previously in a cell line derived
from embryos of the tick, Ixodes scapularis. The cultured Anaplasma (VA-tc) was
passaged continuously for over 4 years and retained its infectivity for cattle
and antigenic stability. We report herein the continuous in vitro cultivation of
a second isolate of A. marginale derived from a naturally infected cow in
Oklahoma (OK-tc). Blood from the infected cow was subinoculated into a
splenectomized calf and blood collected at peak parasitemia was frozen, thawed
and used as inoculum on confluent tick cell monolayers. Colonies of Anaplasma
were apparent in low numbers at 9 days post exposure (PE) and infection in
monolayers reached 100% by 4-5 weeks PE. Cultures were passaged by placing
supernatant onto fresh tick cell monolayers at a dilution of 1:5 or 1:10. By the
third passage development of the OK-tc was similar to that of the VA-tc and a 1:5
dilution resulted in 100% infection in 10-12 days. Inoculation of OK-tc into a
splenectomized calf caused clinical anaplasmosis and Dermacentor ticks that fed
on this calf transmitted the organism to a second susceptible calf. Major surface
proteins (MSPs) 1-5 of the OK-tc were compared with homologous proteins present
on VA-tc and the erythrocytic stage of the Oklahoma isolate. The MSPs 1, 2, 4, 5
were conserved on the OK-tc but there was evidence for structural variation in
MSP3 between the cultured and erythrocytic stage of Anaplasma. MSP2 and MSP3 were
the major proteins recognized by serum from infected cattle. Two-dimensional gels
also identified positional differences between VA-tc and OK-tc in MSP2 and MSP3.
The OK-tc may have potential to be used as antigen for development of an improved
vaccine for anaplasmosis in the South Central United States.
PMID- 10669101
TI - A model to simulate the effect of vaccination against Boophilus ticks on cattle.
AB - This paper describes a vaccination model to simulate the effect of cattle
vaccination with concealed antigens on Boophilus tick spp. The model considers
the vaccination effect in three parts: antibody titer, accumulation of damaging
vaccination effects by parasite stages, and the effect of accumulated damage on
all tick life stages. Biological parameters for ticks and hosts, as well as
parameters describing tick-host interaction, were included. The validity of this
model, integrated with the TICKSIM simulation program, was demonstrated for the
Bm86-containing vaccine Gavac by comparing simulated and real data for several
geographic locations in the Americas. All model parameters were estimated using
field data collected in the different geographic locations. The model sensitivity
to changes in antibody titer level and titer half-life was studied, and the
impact on tick population density of changes in these parameters was evaluated.
Simulation results showed that to achieve a higher level of tick control, an
increase in the maximum antibody titer levels was more important than extending
titer half-life in geographical locations with short seasonal peaks of tick
infestation. The TICKSIM program, integrated with the new vaccination model,
proved to be a framework for designing and evaluating tick control strategies,
including vaccination with GavacTM.
PMID- 10669102
TI - Comparative distribution of ivermectin and doramectin to parasite location
tissues in cattle.
AB - Pharmacokinetic studies have been used traditionally to characterize drug
concentration profiles achieved in the bloodstream. However, endectocide
molecules exert their persistent and broad spectrum activity against parasites
localized in many different tissues. The aim of this study was to compare the
distribution of ivermectin (IVM) and doramectin (DRM) to different tissues in
which parasites are found following subcutaneous administration to calves.
Holstein calves weighing 120-140 kg were injected in the shoulder area with
commercially available formulations of IVM (Ivomec 1% MSD AGVET, NJ, USA) (Group
A) or DRM (Dectomax 1%, Pfizer, NY, USA) (Group B). Two treated calves were
sacrificed at 1, 4, 8, 18, 28, 38, 48 or 58 days post-treatment. Plasma, abomasal
and small intestinal fluids and mucosal tissues, bile, faeces, lung and skin
samples were collected, extracted, derivatized and analyzed by high performance
liquid chromatography (HPLC) with fluorescence detection to determine IVM and DRM
concentrations. IVM and DRM were distributed to all the tissues and fluids
analyzed. Concentrations >0.1 ng/ml (ng/g) were detected between 1 and 48 days
post-treatment in all the tissues and fluids investigated. At 58 days post
treatment, IVM and DRM were detected only in bile and faeces, where large
concentrations were excreted. Delayed Tmax values for DRM (4 days post
administration) compared to those for IVM (1 day) were observed in the different
tissues and fluids. High IVM and DRM concentrations were measured in the most
important target tissues, including skin. The highest IVM and DRM concentrations
were measured in abomasal mucosa and lung tissue. Enhanced availabilities of both
IVM (between 45 and 244%) and DRM (20-147%) were obtained in tissues compared to
plasma. There was good correlation between concentration profiles of both
compounds in plasma and target tissues (mucosal tissue, skin, and lung). Drug
concentrations in target tissues remained above 1 ng/g for either 18 (IVM) or 38
(DRM) days post-treatment. The characterization of tissue distribution patterns
contributes to our understanding of the basis for the broad-spectrum endectocide
activity of avermectin-type compounds.
PMID- 10669103
TI - Claudin-1 contributes to the epithelial barrier function in MDCK cells.
AB - Tight junctions (TJs) create a paracellular permeability barrier and also act as
a fence preventing intermixing of proteins and lipids between the apical and
basolateral plasma membranes. Recently, claudin-1 has been identified as an
integral membrane protein localizing at TJs, and introduced claudin-1 can form TJ
like networks in fibroblasts. To investigate the function of claudin-1, MDCK
cells were transfected with a mammalian expression vector containing myc-tagged
mouse claudin-1, and four stable clones were obtained. The myc-tagged claudin-1
precisely colocalized with both occludin and ZO-1 at cell-cell contact sites,
indicating that exogenous claudin-1 was properly targeted to the TJs. Immunoblot
analysis revealed that overexpression of claudin-1 increased expression of ZO-1
but not of occludin or ZO-2. The barrier functions of these cells were evaluated
by transepithelial electrical resistance (TER) and paracellular flux. Claudin-1
expressing cells exhibited about four times higher TER than wild-type MDCK cells.
Consistent with the increase of TER, the cells overexpressing claudin-1 showed
reduced paracellular flux, estimated at 4 and 40 kD FITC-dextrans. These results
suggest that claudin-1 is involved in the barrier function at TJs.
PMID- 10669104
TI - Dynamics of gap junctions observed in living cells with connexin43-GFP chimeric
protein.
AB - To study the aggregation of cell-to-cell channels into gap junctions at
individual cell-cell contacts, we transfected cells with an expression vector for
a chimeric protein composed of the cell-to-cell channel protein connexin43 and a
green fluorescent protein. The chimeric channel protein was visualized in the
fluorescence microscope and was found to form gap junctions at the cell-cell
contacts just like wild-type connexin43. Cells expressing the chimeric protein
had functional cell-to-cell channels. Using timelapse videomicroscopy on live
cells we observed individual gap junctions over long periods and recorded the
time course of aggregation of the chimeric channel protein into gap junctions at
newly formed cell-cell contacts. We found that individual small gap junctions
were very dynamic, moving about or becoming assembled and disassembled in the
course of minutes. Larger gap junctions were more stable than small punctate
ones. In control condition, stable new gap junctions were not formed during
observation times of 30 min or longer. But at elevated levels of cyclic adenosine
monophosphate, the chimeric channel protein began aggregating at new junctions 5
10 minutes after cell-cell contact and continued to concentrate there for at
least one hour. Also already established junctions grew in size. The fluorescent
chimeric channel protein will be an excellent tool to investigate the regulation
of trafficking of connexin from and to the membrane and the mechanism of connexin
channel aggregation into gap junctions.
PMID- 10669105
TI - Transforming growth factor-beta1 regulates basement membrane formation by
alveolar epithelial cells in vitro.
AB - Immortalized alveolar type II epithelial (SV40-T2) cells formed a continuous,
thin lamina densa when they were cultured on collagen fibrils with the supplement
of 1.0 ng/ml TGF-beta1. Corresponding to lamina densa formation,
immunohistochemical analysis of laminin, type IV collagen, perlecan, and entactin
(nidogen) indicated integration of these components in a linear array beneath the
SV40-T2 cells. Synthesis of these basement membrane constituents was
significantly enhanced by TGF-beta1 in a dose-dependent manner. On the other
hand, TGF-beta1 did not affect the synthesis of extracellular matrix-regulatory
enzymes and their inhibitors, such as type II transglutaminase, matrix
metalloproteinase-2, plasminogen activator inhibitor-1, or tissue inhibitor of
matrix metalloproteinase-1. These results indicate that basement membrane
formation in the presence of 1.0 ng/ml TGF-beta1 is attributable to enhanced
synthesis of basement membrane constituents. However, formation of a continuous
basement membrane was inhibited at a TGF-beta1 concentration of 5.0 ng/ml.
Synthesis of the basement membrane constituents was further enhanced at this
concentration and the extracellular matrix-regulatory enzymes remained unchanged.
The deposits of cellular fibronectin and type I collagen beneath SV40-T2 cells
were significantly augmented. Thus excessive production of interstitial
extracellular matrix components appears to obstruct the integration of basement
membrane constituents into a continuous architecture. These results indicate that
the basement membrane formation by SV40-T2 cells is achieved at the optimal TGF
beta1 concentration.
PMID- 10669106
TI - Activity-independent cell adhesion to tissue-type transglutaminase is mediated by
alpha4beta1 integrin.
AB - Transglutaminases (TGases) are enzymes which catalyze cross-link formation
between glutamine residues and lysine residues in substrate proteins. We have
previously reported that one of the TGases, blood coagulation factor XIIIa
(FXIIIa), is capable of mediating adhesion of various cells. In this paper, we
report for the first time that tissue-type transglutaminase (TGc) also has cell
adhesion activity. TGc-coated plastic surface promoted adhesion and spreading of
cells in a TGc concentration-dependent manner. However, there are some obvious
differences between cell adhesion mediated by TGc and FXIIIa. As was reported
previously, the adhesion to FXIIIa is dependent on its TGase activity. In
contrast, the TGc-mediated cell adhesion is independent of its TGase activity: 1)
The modification of the active center cysteine with iodoacetamide blocked the
enzyme activity without any effect on cell adhesion; 2) the addition of Mg2+ did
not induce the enzyme activity, but it was as effective as Ca2+ for cell
adhesion; 3) the addition of NH4+ inhibited the enzyme activity but did not
affect the cell adhesion significantly. The integrins involved in these cell
adhesions are quite different. In the case of FXIIIa, alpha vbeta3 and
alpha5beta1 integrins are involved and consequently the RGD peptide substantially
inhibited the adhesion. On the other hand, the cell adhesion to TGc is mediated
by alpha4beta1 integrin but not alpha5beta1; a CS-1 peptide, which represents the
binding site of fibronectin to alpha4beta1 integrin, completely inhibited the
cell adhesion to TGc. It is possible that TGc and FXIIIa may mediate cell
adhesion under different physiological and pathological situations.
PMID- 10669107
TI - Carboxypeptidase E does not mediate von Willebrand factor targeting to storage
granules.
AB - Sorting of von Willebrand factor precursor (pro-vWf) from the trans-Golgi network
to secretory granules (Weibel-Palade bodies) is critical for its conversion to
the biologically active highly multimeric form, as well as for regulated
secretion by the endothelial cells. When expressed in hormone-secretory cells,
vWf is also recognized as a stored protein and is directed to storage granules.
Recently, carboxypeptidase E (CPE) was proposed as a granular sorting receptor
for prohormones (Cool et al., Cell 88: 73, 1997). To explore whether CPE is also
involved in pro-vWf sorting, we initially examined its expression in human
umbilical vein endothelial cells. A specific message for CPE and the protein
itself were detected making it a plausible candidate as a targeting receptor for
vWf in endothelium. To investigate this possibility, we used mice lacking CPE.
The highly multimeric forms, subunit composition and plasma levels of vWf in CPE
deficient mice were similar to those of their wild-type littermates. vWf was also
found in alpha-granules of platelets and in Weibel-Palade bodies of endothelial
cells obtained from the CPE-deficient mice. Furthermore, vWf was released from
the cultured CPE-deficient endothelial cells after stimulation with a
secretagogue. We conclude that CPE is not essential for sorting vWf to the
regulated secretory pathway. Thus, a CPE-independent mechanism must exist for
protein sorting to storage granules.
PMID- 10669108
TI - Comparative analysis of Ca2+ and H+ flux magnitude and location along growing
hyphae of Saprolegnia ferax and Neurospora crassa.
AB - Calcium and proton ion fluxes were mapped at the growing apices of two hyphal
organisms, the oomycete Saprolegnia ferax and the ascomycete Neurospora crassa
and pseudohyphal Saccharomyces cerevisiae using self-referencing ion-selective
probes. S. ferax exhibited well-defined transport zones absent in N. crassa. Ca2+
fluxes were located within 8 microm of the growing hyphal tip; the net Ca2+ flux
was either inward (75% of all experiments) or outward. The inward component of
the net flux was inhibited by Gd3+, known to inhibit Ca2+ permeable stretch
activated channels. Because the Ca2+ flux is located at the region of maximal
hyphal expansion, exocytosis may contribute to Ca2+ efflux, in addition to the
stretch-activated channel mediated influx. Maximal inward H+ flux was observed 10
30 microm behind the hyphal tip where peak mitochondria densities taper off at
the onset of a vacuolation zone, presumably due to highly localized H+
cotransporter activity. By contrast, N. crassa exhibited no net Ca2+ flux and a
consistently inward H+ flux (93% of all experiments) that was homogeneously
distributed up to 60 microm behind the hyphal apex. Both hyphal organisms have
similar tip morphology and growth rates, and are reported to have tip-high
cytosolic Ca2+ gradients associated with growth. Only S. ferax exhibited tip
localized Ca2+ fluxes and a well defined H+ influx zone just behind the tip.
Differences in ecological habitats and cytology--S. ferax is an aquatic organism
that grows as a migrating plug of cytoplasm while N. crassa is normally
terrestrial with a cytoplasm-rich mycelium and highly active cytoplasmic
streaming behind the growing margin--may account for the differences in the
'architecture' of ion transport occurring during the process of tip growth. Net
Ca2+ efflux and H+ influx of growing S. cerevisiae pseudohyphae were also
measured but localization was not possible due to small cell size.
PMID- 10669109
TI - Caulerpenyne blocks MBP kinase activation controlling mitosis in sea urchin eggs.
AB - In a previous study, we demonstrated that caulerpenyne (Cyn), a natural
sesquiterpene having an antiproliferative potency, blocked the mitotic cycle of
sea urchin embryos at metaphase and inhibited the phosphorylation of several
proteins, but did not affect histone H1 kinase activation (Pesando et al, 1998,
Eur. J. Cell Biol. 77, 19-26). Here, we show that concentrations of Cyn that
blocked the first division of the sea urchin Paracentrotus lividus embryos in a
metaphase-like stage (45 microM) also inhibited the stimulation of mitogen
activated protein kinase (MAPK) activity in vivo as measured in treated egg
extracts using myelin basic protein (MBP) as a substrate (MBPK). However, Cyn had
no effect on MBP phosphorylation when added in vitro to an untreated egg extract
taken at the time of metaphase, suggesting that Cyn acts on an upstream
activation process. PD 98059 (40 microM), a previously characterized specific
synthetic inhibitor of MAPK/extracellular signal-regulated kinase-1 (MEK1), also
blocked sea urchin eggs at metaphase in a way very similar to Cyn. Both molecules
induced similar inhibitory effects on MBP kinase activation in vivo, but had no
direct effect on MBP kinase activity in vitro, whereas they did not affect H1
kinase activation neither in vivo nor in vitro. As a comparison, butyrolactone 1
(100 microM), a known inhibitor of H1 kinase activity, did inhibit H1 kinase of
sea urchin eggs in vivo and in vitro, and blocked the sea urchin embryo mitotic
cycle much before metaphase. Immunoblots of mitotic extracts, treated with anti
active MAP-kinase antibody, showed that both Cyn and PD 98059 reduced the
phosphorylation of p42 MAP kinase (Erk2) in vivo. Our overall results suggest
that Cyn blocks the sea urchin embryo mitotic cycle at metaphase by inhibiting an
upstream phosphorylation event in the MBPK activation pathway. They also show
that H1 kinase and MBPK activation can be dissociated from each other in this
model system.
PMID- 10669110
TI - Actin-rich structures formed during the invasion of cultured cells by infective
forms of Trypanosoma cruzi.
AB - Previous work has shown that Trypanosoma cruzi extracellular amastigotes as well
as metacyclic trypomastigotes infect cultured cells in a highly specific parasite
form-cell type interaction. In this work we have investigated the mode of
interaction of both forms with HeLa and Vero cells using scanning electron and
confocal fluorescence microscopy. We examined the distribution of several host
cell components as well as extracellular matrix elements during cell invasion by
both T. cruzi infective forms. Scanning electron microscopy showed that membrane
expansions formed during the invasion of cells by extracellular amastigotes.
These expansions correspond to small cup-like structures in HeLa cells and are
comparatively larger "crater"-like in Vero cells. We detected by confocal
microscopy actin-rich structures associated with the internalisation of both
infective forms of the parasite that correspond to the membrane expansions.
Confocal fluorescence microscopy combining DIC images of cells labelled with
monoclonal antibodies to phosphotyrosine, cytoskeletal elements, integrins, and
extracellular matrix components revealed that some of the components like
gelsolin and alpha-actinin accumulate in actin-rich structures formed in the
invasion of amastigotes of both cell types. Others, like vinculin and alpha2
integrin may be present in these structures without evident accumulation. And
finally, some actin-rich processes may be devoid of components like fibronectin
or alphaV integrin. These studies provide evidence that the repertoire of host
cell/extracellular matrix components that engage in the invasion process of T.
cruzi forms is cell type- and parasite form-dependent.
PMID- 10669111
TI - The Lps locus: genetic regulation of host responses to bacterial
lipopolysaccharide.
AB - Lipopolysaccharide (LPS), an abundant glycolipid of the outer membrane of gram
negative bacteria, is able to provoke a generalized proinflammatory response in
the infected host. Genetic regulation of this trait has been localized to the Lps
locus on mouse chromosome 4. Several inbred mouse strains, including C3H/HeJ,
C57BL/10ScNCr and C57BL/10ScCr, bear mutations at the Lps locus (Lps(d)) that
confer hyporesponsiveness to the immunostimulatory properties of LPS and
susceptibility to overwhelming gram-negative bacterial infection. The phenotypic
expression of Lps(d) is pleiotropic, affecting several cell types crucial to host
defense, including the macrophage. By positional cloning, Toll-like receptor 4
(Tlr4), a transmembrane protein with a cytoplasmic domain that bears homology to
the Interleukin-1 receptor, has been identified as the gene encoded by Lps. Tlr4
is a member of a novel gene family that participates in host defense against
microbial infection in plants, invertebrates and mammals. Discovery of the
molecular basis of the Lps mutation represents a significant advance in defining
the fundamental mechanisms of cellular activation by LPS.
PMID- 10669112
TI - A new class of COX-2 inhibitor, rutaecarpine from Evodia rutaecarpa.
AB - OBJECTIVE AND DESIGN: We investigated the effect of a new class of COX-2
inhibitor, rutaecarpine, on the production of PGD2 in bone marrow derived mast
cells (BMMC) and PGE2 in COX-2 transfected HEK293 cells. Inflammation was induced
by lambda-carrageenan in male Splague-Dawley (SD) rats. MATERIAL: Rutaecarpine
(8,13-Dihydroindolo[2',3':3,4]pyridol[2,1-b]quinazolin -5(7H)-one) was isolated
from the fruits of Evodia rutaecarpa. BMMC were cultured with WEHI-3 conditioned
medium. c-Kit ligand and IL-10 were obtained by their expression in baculovirus.
METHODS: The generation of PGD2 and PGE2 were determined by their assay kit. COX
1 and COX-2 protein and mRNA expression was determined by BMMC in the presence of
KL, LPS and IL-10. TREATMENT: Rutaecarpine and indomethacin dissolved in 0.1%
carboxymethyl cellulose was administered intraperitoneally and, 1 h later, lambda
carrageenan solution was injected to right hind paw of rats. Paw volumes were
measured using plethysmometer 5 h after lambda-carrageenan injection. RESULTS:
Rutaecarpine inhibited COX-2 and COX-1 dependent phases of PGD2 generation in
BMMC in a concentration-dependent manner with an IC50 of 0.28 microM and 8.7
microM, respectively. It inhibited COX-2-dependent conversion of exogenous
arachidonic acid to PGE2 in a dose-dependent manner by the COX-2-transfected
HEK293 cells. However, rutaecarpine inhibited neither PLA2 and COX-1 activity nor
COX-2 protein and mRNA expression up to the concentration of 30 microM in BMMC,
indicating that rutaecarpine directly inhibited COX-2 activity. Furthermore,
rutaecarpine showed in vivo anti-inflammatory activity on rat lambda-carrageenan
induced paw edema by intraperitoneal administration. CONCLUSION: Anti
inflammatory activity of Evodia rutaecarpa could be attributed at least in part
by inhibition of COS-2.
PMID- 10669113
TI - Eosinophils and neutrophils in biopsies from the middle ear of atopic children
with otitis media with effusion.
AB - OBJECTIVE AND DESIGN: The majority of patients with otitis media with effusion
(OME) and atopy have been shown to have elevated levels of eosinophil cationic
protein (ECP) in their middle ear fluid. The mechanism underlying these elevated
levels of ECP is not clear. The purpose of this study was to investigate the
feasibility of a quantitative determination of eosinophils and neutrophils in the
middle ear lining by specific immunocytochemical markers, in order to study the
extent of the involvement of these cells in patients with OME. METHODS: Bilateral
middle ear biopsies from five children with persistent OME and atopy confirmed by
in vitro testing were evaluated for the presence of eosinophils and neutrophils
with monoclonal antibodies against specific granule proteins. Five subjects who
had no signs of effusion or infection but were undergoing routine tympanoplasty
for dry perforations served as controls. The biopsies were embedded in a plastic
resin to improve the structural preservation of the target cells and to increase
the resolution in the light microscope. Dual markers were used to determine which
marker was better for eosinophils and neutrophils, respectively. The following
markers were used: eosinophil cationic protein (EG2), and eosinophil peroxidase
(EPO) for eosinophils and myeloperoxidase (MPO) and human neutrophil lipocalin
(HNL) for neutrophils. RESULTS: Antibodies against EPO gave a more localized and
intense staining than antibodies against EG2. Antibodies against HNL appear more
specific to neutrophils than antibodies against MPO that also recognize
monocytes. The number of cells was determined both in the tissue and in the mucus
covering the epithelium. Eosinophils and neutrophils were present in the
subepithelial connective tissue and in the mucus blanket in the middle ear of
patients with OME in significantly higher number than in the control group. In
general, there were more inflammatory cells in the mucus than in the tissue
itself, but the number of inflammatory cells in the mucus showed a significant
positive correlation with the number of inflammatory cells in the tissue. There
was a significant positive correlation between the number of neutrophils and the
number of eosinophils in the tissue as well as in the mucus, irrespective of
which marker was used. CONCLUSION: The results of this study show the feasibility
of using specific antibodies to identify eosinophils and neutrophils in the
middle ear. The initial data suggest that atopic children with OME have higher
numbers of such cells as compared to non-OME controls.
PMID- 10669114
TI - Eicosanoid release in the endotoxin-primed isolated perfused rat lung and its
pharmacological modification.
AB - OBJECTIVE: Recent observations have demonstrated a central role of the
"inducible" isoform of the cyclooxygenase (COX), COX-2, in the rat lung.
Therefore, the reported capacity of selective COX-2 inhibitors to potentiate the
formation of leukotriene (LT) B4 may raise concern about pro-inflammatory side
effects of such drugs in the respiratory system. The present study was aimed at
determining the effects of the COX-2 inhibitor NS-398 on the release of COX and 5
lipoxygenase (LOX) metabolites of arachidonic acid in isolated perfused lungs
obtained from endotoxin-treated rats before and after stimulation with the
leukocyte secretagogue N-formyl-methionyl-leucyl-phenylalanine (FMLP). METHODS:
Two hours after rats had received endotoxin i.v., the lung was dissected and
perfused via the pulmonary artery with physiological salt solution. After an
equilibration period of 20 min the outflow was collected (5-min fractions). In
the respective treatment groups, indomethacin, NS-398, or the 5-LOX inhibitor
MK886 were present throughout the experiment, while FMLP was added to the
perfusate during a single 5-min period. The concentration of eicosanoids in the
outflow was determined by radioimmunoassay. RESULTS: Endotoxin treatment of rats
resulted in increased expression of COX-2 mRNA in lung tissue, and an elevated
basal release of the prostaglandin (PG)I2 metabolite 6-keto PGF1alpha, without a
detectable increase of leukotriene (LT) formation. In-vitro exposure to FMLP
stimulated LT and prostanoid release, which was significantly enhanced in
endotoxin-primed lungs, and was suppressed by the 5-LOX inhibitor MK-886 (3
microM) and the COX-inhibitor indomethacin (5 microM), respectively. Either
compound showed selective inhibition of the respective pathway of arachidonic
acid metabolism. In endotoxin-primed lungs, the COX-2 inhibitor NS-398 (0.3-1.0
microM) depressed basal as well as FMLP-stimulated release of 6-keto PGF1alpha,
but did not cause a significant increase of LTB4 or cysteinyl-LT release.
CONCLUSIONS: These results suggest that FMLP, presumably acting on inflammatory
cells trapped in the pulmonary circulation of endotoxin treated rats, induced
prostanoid formation mainly via the COX-2 pathway, and that its inhibition by NS
398 had no detectable potentiating effect on LTB4 or cysteinyl-LT biosynthesis.
PMID- 10669115
TI - Chemoattractant-induced release of elastase by tumor necrosis factor-primed human
neutrophils: auto-regulation by endogenous adenosine.
AB - OBJECTIVE AND DESIGN: In the present work, we studied the role of cell-derived
adenosine in both the physiologic regulation and pharmacologic control of the
exocytosis of azurophilic granules of neutrophils exposed to tumor necrosis
factor alpha (TNF) and stimulated with some chemoattractants. MATERIAL AND
METHODS: Human neutrophils were pre-incubated in the absence or presence of TNF.
Thereafter, the appropriate chemoattractant was added to the cells. After
incubation, the cell-free supernatant was collected for testing elastase activity
and intracellular cAMP levels. Results, expressed as mean +/- 1 SD, were
evaluated by unpaired, two-tailed Student's t-test and by analysis of variance
followed by Student-Newman-Keuls multiple comparisons test. RESULTS: Neutrophil
incubation with 10 ng/ml TNF or 0.1 micromol/l N-formyl-met-leu-phe (fMLP) failed
to release elastase activity (NE) (NE in absence of stimulus: 23.1 +/- 5.7
nmol/h; TNF-induced NE: 26.4 +/- 14.4 nmol/h; fMLP-induced NE: 27.0 +/- 9.9
nmol/h). Neutrophils, pre-exposed to various amounts of TNF, released elastase in
response to 0.1 micromol/l fMLP in a dose-dependent manner (NE in presence of 10
ng/ml TNF and 0.1 micromol/l fMLP: 133.7 +/- 24.0 nmoles/h). As compared with
fMLP, C5a had lower activity (NE in presence of 10 ng/ml TNF and 0.1 micromol/l
C5a: 66.4 +/- 25.1 nmoles/h), whereas interleukin-8, platelet activating factor
and leukotriene B4 were ineffective. The secretory response of TNF-primed
neutrophils to fMLP was inhibited by adenosine in a dose-dependent manner (IC50 =
5.18 +/- 7.1 micromol/l). The addition of adenosine deaminase (ADA) to TNF-primed
neutrophils resulted in increased secretory response to fMLP (NE in absence and
presence of 0.25 U/ml ADA: 71.5 +/- 11.0 and 107.3 +/- 18.6 respectively, P =
0.060). Moreover, two inhibitors of phosphodiesterase type IV (RO 20-1724 and
nimesulide) reduced the elastase release only in the absence of ADA (RO 20-1724:
percent inhibition in absence or presence of ADA = 20.2 +/- 15.0 and 4.4 +/- 5.1
respectively; nimesulide: percent inhibition in absence or presence of ADA = 22.2
+/- 19.6 and 0.8 +/- 3.0 respectively). Similarly, RO 20-1724 and nimesulide
increased intracellular cAMP levels only in absence of ADA (RO 20-1724: percent
cAMP increment in absence or presence of ADA = 215.4 +/- 97.5 and 47.3 +/- 53.3
respectively; nimesulide: percent cAMP increment in absence or presence of ADA =
177.7 +/- 19.0 and 19.5 +/- 29.3 respectively). CONCLUSIONS: Endogenous adenosine
down-regulates the cell secretory response and is instrumental in uncovering the
susceptibility of azurophilic granule exocytosis to control by inhibitors of
phosphodiesterase type IV.
PMID- 10669116
TI - Differential effects of interleukin-4 and interleukin-10 on nitric oxide
production by murine macrophages.
AB - OBJECTIVE: To study the effect of interleukin (IL)-4 and IL-10 on nitric oxide
(NO) production by macrophages. MATERIALS AND METHODS: Elicited or resident
peritoneal macrophages (PMO) and a macrophage cell line Raw264.7 were primed by
IL-4 or IL-10 for 6 hours, and were further incubated in the presence of
interferon (IFN)-gamma and/or lipopolysaccharide (LPS) for 48 hours. NO2-
accumulation in the supernatant of cultured cells was used as an indicator of NO
production and was determined by the standard Griess reaction adapted for
microplates. The amount of tumor necrosis factor (TNF)-alpha in the culture
supernatants was determined with a commercially available ELISA kit. The
absorbance was measured at 450 nm with a microplate photometer. RESULTS: IL-4
inhibited NO production by murine macrophages of different sources and the
macrophage cell line Raw264.7. In contrast, different macrophage populations
showed differential responses to IL-10. After stimulation with LPS or IFN-gamma,
IL-10 suppressed NO production by elicited PMO but enhanced NO production by
resident PMO or by Raw264.7. Both IL-4 and IL-10 inhibited the production of TNF
alpha, which has been shown to play a crucial role in NO production. In the
presence or the absence of blocking antibody to TNF-alpha, IL-10 always enhanced
NO production by resident PMO. This result suggests that the inhibition of TNF
alpha production and the enhancement of NO production by resident PMO stimulated
with IL-10 are independent, coexisting events. CONCLUSIONS: Factors other than
TNF-alpha have been suspected to influence NO production by macrophages, and this
study indicates that IL-10 may be a candidate cytokine for resident PMO.
PMID- 10669117
TI - Detection of an approximately 100 kD protein with strong immunoreactivity to
antibodies specific for inducible nitric oxide synthase (iNOS) but without NOS
activity in neutrophils of patients suffering from sepsis: results of a
preliminary study.
AB - OBJECTIVE: The study was designed to evaluate the expression of inducible nitric
oxide synthase (iNOS) in activated human neutrophils. SUBJECTS AND METHODS: By
Western blotting and immunocytochemical staining, iNOS expression was analyzed in
neutrophils from patients with sepsis who we classified by high plasma nitrate as
subjects with activated NO metabolism. For comparison, rats treated with Zymosan
documented to induce iNOS were analyzed. RESULTS: Strong immunoreactivity to
antibodies for iNOS was detected in leukocytes of Zymosan treated rats and in
neutrophils of septic patients. Such immunoreactivity was absent in untreated
rats and healthy subjects. In rats, the immunoreactivity was associated to the
130 kD protein as expected for iNOS. In contrast, the intense iNOS staining in
neutrophils of septic patients was associated to an approximately 100 kD protein.
Despite the iNOS staining, no increased NOS activity could be demonstrated in the
neutrophils of septic patients. CONCLUSIONS: The detection of an approximately
100 kD protein with immunoreactivity to antibodies recognizing human iNOS but
without NOS activity in neutrophils of patients with sepsis should initiate
studies to elucidate the origin and function of this protein.
PMID- 10669118
TI - Glucocorticoids, antioxidants and staurosporine modulate the adherence between
monocytes and malaria infected erythrocytes.
AB - OBJECTIVE AND DESIGN: Adherence interactions involving monocytes are important
for cell-cell interaction as an integral component of immune function. The
adherence of malaria parasitised red cells to monocytes was determined after
monocytes were treated with dexamethasone, cortisol, ambroxol, danazol, probucol
and staurosporine. MATERIALS: Human peripheral blood monocytes isolated by
density gradient centrifugation and adherence to glass cover slips. METHODS: The
adherence of malaria parasitised red cells to monocytes was determined after the
monocytes were incubated for 24 h in the presence of each of the 6 drugs.
RESULTS: The two glucocorticoids and staurosporine reduced the adherence of
malaria infected erythrocytes to monocytes in a dose dependent manner at
concentrations from 10(-10) M and above and ambroxol, danazol, and probucol at
10(-5) M. Staurosporine was the most effective of the drugs studied, completely
abolishing adherence at 10(-6) M. CONCLUSION: The adherence of malaria infected
erythrocytes to monocytes is reduced in response to glucocorticoids
(dexamethasone and cortisol), anti-oxidants (probucol and ambroxol), danazol and
staurosporine.
PMID- 10669119
TI - Pharmacological modulation of the IFNgamma-induced accessory function of alveolar
macrophages and peripheral blood monocytes.
AB - OBJECTIVE AND DESIGN: Although alveolar macrophages (AM) are poor accessory
cells, alveolar macrophages of patients with sarcoidosis or tuberculosis show an
elevated accessory function indicating that the accessory function (AF) of AM can
be upregulated. MATERIALS AND METHODS: We examined whether the AF of AM and
peripheral blood monocytes (PBM) can be increased by interferon-gamma (IFNgamma)
and whether immunomodulating drugs like cyclosporine A, cyclophosphamide,
dexamethasone, and ambroxol are able to modulate the accessory function and the
expression of accessory molecules. RESULTS: IFNgamma increased the AF of AM and
PBM up to 309 +/- 122% and 152 +/- 25%, respectively (p < 0.02, unstimulated
control = 100%, in all cases). In alveolar macrophages this increase is most
efficiently prevented by cyclosporine A (31 +/- 13%), followed by
cyclophosphamide (64 +/- 20%) and dexamethasone (66 +/- 20%). In monocytes the
IFNgamma-induced increase in accessory function is prevented only by cyclosporine
A (17 +/- 7%) and dexamethasone (59 +/- 9%). Cyclosporine A was also the most
effective drug downregulating the expression of accessory molecules (CD54, CD58,
CD80 and CD86). CONCLUSIONS: In summary, the accessory function of alveolar
macrophages and monocytes is upregulated by IFNgamma and can be controled by
immunomodulating drugs.
PMID- 10669120
TI - Trends in presentation of congenital heart disease in a population-based study in
Malta.
AB - Differing pathological haemodynamics in cardiac malformations lead to varying
modes and timings of presentation. This study identifies historical trends in
presentation of congenital heart disease in a population-based study. All
patients diagnosed as having congenital heart disease in Malta between 1960-1994
were included (n = 868). Analysis was carried out on trends in referral sources,
modes of presentation and birth prevalence. The number of patients diagnosed with
congenital heart disease increased over the period under study. For both patients
not requiring intervention (n = 283) and those requiring intervention (n = 585),
the proportion diagnosed prior to hospital discharge increased (p < or = 0.005).
There was a decreasing trend for general practitioners to refer cases (p <
0.0001), and an increasing trend for paediatricians to refer such patients (p <
or = 0.0003). The commonest presentation to the general practitioner was an
incidental finding (92%), while paediatricians referred more patients for
cyanosis or heart failure (p < or =, 0.005). For lesions not requiring
intervention, the commonest lesion referred was ventricular septal defect from
all sources. For lesions requiring intervention, the commonest lesion detected
prior to hospital discharge was tetralogy of Fallot. Atrial septal defects were
the commonest lesions detected after discharge by both paediatricians and general
practitioners. An increase in the proportion of hospital diagnoses is attributed
to increasing rate of hospital delivery, and greater training and experience in
doctors performing neonatal examinations prior to discharge. Patients diagnosed
after discharge are increasingly diagnosed by paediatricians due to an increasing
pool of paediatricians and better parent awareness and education.
PMID- 10669121
TI - Time trends in incidence of cervical cancer in Lithuania from 1983 to 1997.
AB - This report examines time trends in both age-specific and age-standardized
cervical cancer (ICD9-180) incidence rates among Lithuanian women. The study
covers the period from 1983 to 1997. In case of the age-specific rates Poisson
regression revealed the controversial results for the different age groups. The
incidence rates increased (beta > 0) for the women below 50 years and decreased
(beta < 0) for the women above 50 years. The average annual percentage changes
were estimated using the age-drift model. In the age groups from 30 to 49 years
old the incidence rate increased by 3.3% per year with the 95% confidence
interval (CI) being 2.2-4.4. In the age groups from 50 to 69 years old the
incidence rate decreased by 2.9% (95% CI: 1.9-3.8). In case of the age
standardized rates during the last few years some increase was observed, although
no strict conclusions could be drawn. This observation together with the results
of the age-specific rate studies predicts that in the near future the age
standardized rate will start growing.
PMID- 10669122
TI - Antihypertensive drug therapy and hypoglycemia in elderly diabetic patients
treated with insulin and/or sulfonylureas. Gruppo Italiano di Farmacovigilanza
nell'Anziano (GIFA).
AB - We performed this case control study to evaluate the risk of hypoglycemia
associated with the use of antihypertensive drugs in older hospitalized diabetic
patients treated with sulfonylureas and/or insulin. All diabetic patients
admitted during 4 months in 1988, month in 1991, 4 months in 1993 and 4 months in
1995 (n = 3477, mean age 71.4 +/- 0.2 years, 1542 males and 1935 females) were
enrolled in the study. During the four annual surveys 86 patients (mean age 71.1
+/- 1.4 years, 33 males and 53 females) presented hypoglycemia during hospital
stay. The patients who presented hypoglycemia were less frequently users of
sulfonylureas and more frequently users of a combination of insulin and
sulfonylureas. Use of antihypertensive drugs was similar in the two groups
studied, and among potentially interacting drugs considered in the analysis,
sulfonamides were more frequently used in patients who experienced hypoglycemia.
Moreover, patients with hypoglycemia used a higher number of drugs, had a longer
length of stay and had a greater prevalence of hypoglycemia as admission problem.
Finally, although not significant, liver and renal diseases were more frequent
among patients with hypoglycemia. In the multivariate analysis, contemporary use
of insulin and sulfonylureas, liver disease and length of stay were significantly
associated with hypoglycemia, while none of the antihypertensive drugs showed a
significant association with the occurrence of hypoglycemia during hospital stay.
Our results indicate that antihypertensive drugs do not increase the risk of
hypoglycemia in elderly diabetic patients.
PMID- 10669123
TI - Prevalence of antibodies to hepatitis A among children and adolescents in Larnaca
area, Cyprus.
AB - The prevalence of antibodies to hepatitis A virus was investigated in 385
children and adolescents (52.2% males), aged 6 to 18, in the Larnaca area of
Cyprus. This is the first study investigating the prevalence of hepatitis A in
Cyprus for this age group. The population was stratified into two groups: 6 to 12
years old and 13 to 18 years old. None of the subjects in the first group were
positive. The prevalence of hepatitis A in the age of group 13 tol8 was 1.6%. In
conclusion, the low prevalence of anti-HAV demonstrates the susceptibility of
young Cypriots to hepatitis A. This is a cause for concern as these unprotected
young adults are frequently exposed to potentially infected individuals.
PMID- 10669124
TI - Maternal knowledge and environmental factors associated with risk of diarrhea in
Israeli Bedouin children.
AB - Diarrhea is still a major cause of morbidity and mortality among children in
developing countries. As it is due to multiple causative agents including
viruses, bacteria and parasites, biological interventions are not currently
available to markedly reduce incidence and severity. We examined maternal
knowledge and reported behavior during diarrheal episodes, as well as
environmental factors to determine their association with diarrhea. The children
and mothers were from a Bedouin township in southern Israel, which has developed
preventive and curative health care facilities. The Bedouin population in Israel
is in transition from a nomadic to a settled life style. While almost all mothers
exhibited good knowledge regarding food storage and prevention of diarrhea
episodes in the children, the rate of illness in the children remained relatively
high (two episodes per child year of observation). In a multivariate analysis,
cessation of breastfeeding during diarrhea, child sleeping with siblings and lack
knowledge about risk factors, were the major risk factors for illness with odds
ratios (OR): 4.6, p = 0.02, 5.6, p = 0.03 and 1.7, p = 0.06, respectively. These
data indicate that even in this population with free access to preventive medical
care, greater efforts should be made to educate mothers regarding risk factor for
diarrheal disease identification and the benefits of maintaining breastfeeding
during diarrhea episodes.
PMID- 10669125
TI - Prevalence of bacterial vaginosis and correlation of clinical to Gram stain
diagnostic criteria in low risk pregnant women.
AB - The present study aimed to evaluate the prevalence of bacterial vaginosis, and
the correlation of clinical Amsel criteria with Gram Nugent criteria for the
diagnosis of bacterial vaginosis in a low risk population of pregnant women.
Pregnant women under 28 weeks of gestation who were followed in the low risk
clinics at two centers were evaluated for the presence of bacterial vaginosis
using the Amsel clinical criteria, and underwent vaginal samples for Gram
staining. Gram smears were examined for the diagnosis of bacterial vaginosis on
the basis of Nugent's criteria. A total of 492 women were included in the study.
Bacterial vaginosis was diagnosed in 1.6% (8/492) women on the basis of clinical
criteria, and in 4.5% (22/492) according to Gram stain. The sensitivity and
specificity of Amsel criteria compared with Gram stain were 35% and 99%,
respectively. In accordance with other recent reports, the prevalence of
bacterial vaginosis appears to be much lower in certain areas than figures
previously suggested. In these populations, the correlation of composite clinical
criteria defined in groups with high prevalence of bacterial vaginosis appears to
be also poor.
PMID- 10669126
TI - Botulism surveillance in Italy: 1992-1996.
AB - Though a relatively rare disease, botulism can be a serious problem of public
health, particularly when connected with the consumption of industrial canned
food; moreover, in the last years the shortage of botulism antitoxin has caused
some concern in the Public Health Authorities. This work presents the results of
a five-year surveillance of botulism in Italy, with the distribution of the cases
by Regions (first level administrative units which, in Italy, have administrative
and legislative competencies in the sanitary field) and by vehicle of
transmission. All the relevant and confirmed botulism outbreaks that occurred in
the period under consideration are described.
PMID- 10669127
TI - A review of zygomycosis due to Basidiobolus ranarum.
AB - Zygomycosis due to Basidiobolus ranarum (entomophthoromycosis basidiobolae,
subcutaneous zygomycosis, subcutaneous phycomycosis, basidiobolomycosis) is a
granulomatous infection of the skin and subcutaneous tissues characterized by the
formation of fluctuant firm and non-tender swellings, generally on the
extremities, trunk and rarely other parts of the body. The causative agent is
common in soil, decaying vegetable matter, and the gastrointestinal tracts of
amphibians, reptiles, fish and bats. It is presumed that infection is acquired
through exposure to B. ranarum following minor trauma to skin or insect bites.
The disease usually occurs in children, less often in adolescents and rarely in
adults. Males are much more frequently affected than females. Laboratory
diagnosis is based on histopathology and culture. The typical histopathological
feature is the presence of thin-walled, broad often aseptate hyphae or hyphal
fragments with an eosinophilic sheath, frequently phagocytized within giant
cells. Basidiobolus ranarum is known to produce several enzymes, e.g. lipase and
protease that probably play roles in the pathogenesis of infections caused by
this mould. An immunological test has been developed for specific diagnosis of
the disease. Though potassium iodide (KI) has been the traditional drug employed
in the treatment of infections by B. ranarum, several other drugs, viz
amphotericin B, cotrimoxazole, ketoconazole, itraconazole and fluconazole have
been successfully tried.
PMID- 10669128
TI - Canine neosporosis: clinical and pathological findings and first isolation of
Neospora caninum in Germany.
AB - Neosporosis was diagnosed in an 11-week-old puppy of the breed Kleiner
Munsterlander with progressive hindlimb paresis. Pathohistological and
immunohistological examinations revealed a disseminated infection with Neospora
caninum. Parasitic stages were demonstrated in the brain, spinal cord, retina,
muscles, thymus, heart, liver, kidney, stomach, adrenal gland, and skin.
Immunohistochemistry investigations were carried out using polyclonal rabbit
antisera developed against N. caninum tachyzoites and the recombinant bradyzoite
specific antigen BAG-5 of Toxoplasma gondii, which is known to cross-react with
N. caninum bradyzoites. BAG-5 antibodies recognized tissue cysts within the CNS
and some protozoan stages that were not surrounded by a visible cyst wall. All
parasite clusters in the retina and some in muscle tissue stained positively with
the BAG-5 antiserum. N. caninum was isolated in cell culture and mice inoculated
with brain and spinal cord of the puppy. The new isolate is the first reported in
Germany and is designated NC-GER1.
PMID- 10669129
TI - Blastocystis hominis: origin and significance of vacuolar and granular forms.
AB - Using supravital neutral red staining and light microscopy, individual
Blastocystis organisms, subcultured from clinical isolates in modified monophasic
Robinson's medium, were followed over various periods on glass slides. A rapid
transition from uniformly stained to granular and vacuolated forms preceded the
organism's death as evidenced by pale staining and Brownian motion in the cell's
interior. Granular and vacuolar forms of Blastocystis may indicate degenerative
changes in individual cells, fixation artifact, or both.
PMID- 10669130
TI - Labeled probes inserted in the macrophage membrane are transferred to the
parasite surface and internalized during cell invasion by Toxoplasma gondii.
AB - Tachyzoites of Toxoplasma gondii attach to the macrophage surface and are
internalized either by a phagocytic process, which can be inhibited by
cytochalasin D, or by an active process, independent of host cell actin. Previous
studies have shown that parasite attachment induces the secretion of
macromolecules found in the apical organelles (micronemes and rhoptries) and
subsequent/concomitant parasite internalization with the formation of a membrane
bound vacuole known as the parasitophorous vacuole. In the present study we
labeled the macrophage surface with fluorescent probes that bind to proteins
(DiIC16) and lipids (DTAF) and then allowed control or cytochalasin-D-treated
cells to interact with untreated or antibody-coated tachyzoites of T. gondii. The
interaction was interrupted at different time points by fixation and the
distribution of the probes was analyzed by confocal laser scanning microscopy.
Following attachment of the parasites to the macrophage surface, intense labeling
of the parasite surface was observed, suggesting transfer of components of the
macrophage surface to the parasite surface. Nonadherent parasites were not
labeled. Immediately after attachment, most of the parasites were internalized
and labeling of the internalized parasites as well as of the parasitophorous
vacuole, probably of its membrane, was evident, indicating that surface
components of the macrophage are involved in the formation of the parasitophorous
vacuole.
PMID- 10669131
TI - Ribosomal RNA of Nosema algerae and phylogenetic relationship to other
microsporidia.
AB - Microsporidia are intracellular parasites that are common in invertebrates.
Taxonomic classification is mostly restricted to morphologic and physiologic
data. Limited data are available about taxonomic classification using DNA
sequence data for analysis. We examined the small-subunit (SSU) rDNA, the
intergenic spacer (ITS) region, and a part of the large-subunit (LSU) rDNA of
Nosema algerae, a parasite of mosquitoes, taken from a laboratory colony of
Anopheles stephensi. Target gene amplifications were done by polymerase chain
reaction (PCR) and, after cloning, DNA fragments were sequenced. The SSU-rDNA
sequence obtained was aligned with several other microsporidian SSU-rDNA
sequences available from the GenBank or EMBL data bases and was analyzed by
different methods. On the basis of the results of our phylogenetic analysis, we
suggest that our N. algerae isolate is not closely related to other microsporidia
belonging to the genus Nosema.
PMID- 10669132
TI - A cDNA encoding a nuclear hormone receptor of the steroid/thyroid hormone
receptor superfamily from the human parasitic nematode Strongyloides stercoralis.
AB - A cDNA encoding a nuclear hormone receptor of the steroid/thyroid receptor
superfamily was obtained from third-stage larvae(L3) of the parasitic roundworm
Strongyloides stercoralis. A recombinant clone was isolated via screening of an
S. stercoralis cDNA library with a polymerase chain reaction (PCR)-generated
probe. The insert of 2,583 bp contained the complete coding sequence of the
receptor homologue. The conceptually translated amino acid sequence of this open
reading frame encodes a 753-amino-acid-residue protein with an apparent molecular
weight of 83.6 kDa and a predicted isoelectric point (pI) of 8.52. The coding
sequence is 69% AT and the noncoding sequence is 72% AT, reflecting a
characteristic A/T codon bias of S. stercoralis. In this report the amino acid
sequence of the S. stercoralis nuclear hormone receptor of the steroid/thyroid
receptor superfamily is compared with that of nuclear hormones of Caenorhabditis
elegans, human orphan nuclear receptors, and insect ecdysone receptors. The
potential role of steroids in the induction of hyperinfection syndrome is also
discussed.
PMID- 10669133
TI - Immunolocalization of two hydrogenosomal enzymes of Trichomonas vaginalis.
AB - Three monoclonal antibodies specific for malic enzyme and for the alpha- and beta
subunits, respectively, of the succinyl-coenzyme A (CoA) synthetase of
Trichomonas vaginalis were used to immunolocalize these proteins in the cell. All
antibodies labeled the hydrogenosome matrix as determined both by
immunofluorescence and by immunogold staining. There was no labeling on the cell
surface or in any other cell compartment. These results support the idea that
these proteins are restricted to a hydrogenosomal function and do not play a role
as adhesins at the plasma membrane surface.
PMID- 10669134
TI - Differential protein kinase C phosphorylation sites in the L17 ribosomal protein
from Leishmania infantum.
AB - Leishmania infantum, the protozoan parasite responsible for leishmaniasis in
Europe, is capable of undergoing developmental changes in vitro and provides an
excellent model for the study of cell differentiation processes. We have cloned
the gene encoding the L17 ribosomal protein. The LiL17 protein family belongs to
the macrolide binding site, related to the peptidyl transferase center of the
ribosome. Its comparison with other members of the protein family shows several
structural differences that may reflect functional variations. The protein kinase
C phosphorylation sites display an intermediate pattern involving differences in
location and type of residue with respect to all the species considered. Gene
structural analysis suggests the existence of two different encoding genes. The
expression of the genes seem to be different with the distinct growth phases of
the parasite.
PMID- 10669135
TI - Otobothrium cysticum (Cestoda: Trypanorhyncha) from the muscle of butterfishes
(Stromateidae).
AB - On the basis of the tentacular armature, surface ultrastructure, and
morphological measurements of plerocerci obtained from the musculature of
butterfishes (Stromateidae), we corroborate an earlier proposal that Otobothrium
crenacolle, a commonly reported trypanorhynch cestode from the northwestern
Atlantic coast, is a junior synonym of O. cysticum. This action exemplifies at
least an Atlantic Ocean and Indian Ocean distribution for O. cysticum. The
infection in commercially important butterfishes shows that an otobothriid
trypanorhynch may heavily infect fish flesh and influence the market value of
some fish species yet also be restricted to the body cavity of other fish
intermediate hosts. Infections of O. cysticum in the flesh of Peprilus burti
(Gulf butterfish) and P. alepidotus (harvestfish) in the Gulf of Mexico has
varied annually since 1970, with samples ranging in prevalence between 20% and
100% and in mean intensity between 1 and 3,500 or more plerocerci per fish.
Comparative infections in P. burti from the Gulf of Mexico and P. triacanthus
(butterfish) from the Atlantic Ocean demonstrate a present geographic difference
in infections. The prevalence and mean intensity in 4 collections of butterfishes
ranged from 9% to 98% of the fish and from 1 to 678 plerocerci in a subsample of
tissue, respectively, with prevalent and heavy infections being observed in the
Gulf of Mexico fish and relatively few individuals being infected with few worms
in the Atlantic fish. A slight host response in the butterfishes involving some
fatty infiltration and inflammatory infiltration was associated with the
metacestode. In some larger fish, encapsulations were yellow, and in a few cases,
worms had degenerated. This finding and an increase in intensity with fish weight
suggest a continual accumulation of the worms in association with little host
resistance.
PMID- 10669136
TI - Ultrastructure of the Endolimax nana cyst.
AB - This is the first report on the ultrastructure of the Endolimax nana cyst. These
cysts are mostly ovoid in shape and have a distinct cyst wall measuring 80 nm.
The nuclear membrane is without pores or associated chromatin deposits. The
cytoplasm does not have mitochondria or a Golgi apparatus but shows elongated
tubular structures made up of a double row of ribosome-like particles. The nature
and function of this structure is not known, but it appears to be characteristic
of this species and has not been reported from any other intestinal ameba.
PMID- 10669138
TI - Restriction-fragment-length polymorphism analysis of small-subunit rRNA genes of
Blastocystis isolates from animal hosts.
AB - The anaerobic enteric protozoan organism Blastocystis sp. has been identified
from mammalian, avian, reptilian, and arthropod hosts. Eight Blastocystis
isolates from five animal host species (cow, goat, sheep, guinea pig, and rhea)
were compared by small-subunit ribosomal RNA (ssu rRNA) restriction-fragment
length polymorphism (RFLP) analyses using five restriction endonucleases. The
isolates sorted into five genotypes. Multiple genotypes were found in isolates
from a single animal host species, and multiple host species shared a single
genotype. A molecular method such as RFLP analysis of ssu rRNA genes facilitates
the characterization of Blastocystis isolates from various host species.
PMID- 10669137
TI - Restriction-fragment-length polymorphism analysis of small-subunit rRNA genes of
Blastocystis hominis isolates from geographically diverse human hosts.
AB - Genomic diversity among 14 isolates of Blastocystis hominis from 4 different
geographic locations was examined by small-subunit rRNA (ssu rRNA) restriction
fragment-length polymorphisms (RFLP) using 5 different restriction endonucleases.
On the basis of the observed RFLP patterns among the isolates, a total of 12
genotypes were identified, with 7 isolates exhibiting mixed RFLP genotypes. There
was no correlation between B. hominis geographic origin and RFLP banding pattern
or genotype.
PMID- 10669139
TI - Assessment of a recombinant antigen versus natural hypodermin C for the
serodiagnosis of hypodermosis in cattle.
AB - An indirect ELISA test using as antigen a recombinant parasite protein,
hypodermin C, was developed to measure Hypoderma-specific antibodies in cattle
sera and compared with natural hypodermin C. To evaluate the field efficacy of
the ELISA test, 334 serum samples were collected from cows raised at farms in
Galicia for a serological survey. Compared with an ELISA based on natural
parasite antigen, the recombinant hypodermin C gave excellent results, with a
sensitivity of 95.8% and a specificity of 95.7%. Considering the cut-off point,
with the recombinant hypodermin C, 70.9% of the animals had positive levels of
antibodies to Hypoderma and with natural hypodermin C, 73.6%. Recombinant
hypodermin C appears to be a useful alternative to the natural parasite antigen
for the serodiagnosis of Hypoderma sp in cattle.
PMID- 10669140
TI - Variability of Fasciola hepatica infection in Lymnaea ovata in relation to snail
population and snail age.
AB - Bimiracidial infections of Lymnaea ovata with Fasciola hepatica were performed
under laboratory conditions to determine the susceptibility of snails from six
French populations to trematode infection. In five populations of L. ovata the
prevalence of infection in the 1-mm groups ranged between 2.7% and 43.7% at day
35 postexposure; it decreased in the 2-mm snails and was zero in larger groups.
In the snails from Thenay (periodically polluted brook) the prevalence of F.
hepatica infection decreased from the 1-mm group to the 8-mm group (from 23.9% to
1.0%) and was zero in the 10-mm L. ovata. The total number of cercariae shed per
snail was 18.3 in the 1-mm group, increasing to 117 in the 8-mm group. The latter
findings could be interpreted as a consequence of periodic pollution in the brook
of Thenay; pollution might disrupt the defense system of L. ovata and facilitate
the subsequent larval development of F. hepatica.
PMID- 10669141
TI - A monoclonal antibody against Schistosoma haematobium soluble egg antigen:
efficacy for diagnosis and monitoring of cure of S. haematobium infection.
AB - A monoclonal antibody (mAb), 2F/11F, raised against Schistosoma haematobium
soluble egg antigen (SEA) was found to be nonreactive with S. mansoni SEA or
other parasite antigens (Fasciola hepatica, Echinococcus granulosus). This IgG1
mAb recognized a repetitive epitope on S. haematobium SEA in the molecular-weight
regions of 70, 42, and 35 kDa. It was employed as both an antigen-capture and a
biotinylated detection antibody in a sandwich enzyme-linked immunosorbent assay
(ELISA) for the detection of circulating schistosome antigen (CSA) and had a
detection limit of <1 ng S. haematobium SEA/ml. CSA levels were measured in serum
and urine samples from 116 S. haematobium-infected rural students before therapy
and at 4, 8, and 12 weeks after praziquantel treatment. Serum and urine samples
from 50 S. mansoni -infected patients, 15 patients harboring other parasites, and
30 noninfected individuals were also assessed. CSA was detected in 90.5% of serum
samples and 94% of urine samples from S. haematobium-infected patients. CSA was
undetectable in serum from the 15 patients harboring other parasites and in 94%
of serum samples and 84% of urine samples from S. mansoni-infected patients. In
the S. haematobium-infected group a positive correlation was detected between CSA
levels in serum and urine samples and the egg load per 10 ml urine. A significant
reduction in CSA levels was detected in serum and urine samples after
praziquantel therapy. CSA was undetectable in 87% of serum samples and 81.5% of
urine samples from schistosomiasis haematobium patients at 12 weeks post
treatment. These data demonstrate that the use of mAb 2F/11F for detection of CSA
provides a sensitive method for the immunodiagnosis and monitoring of cure of
schistosomiasis haematobium.
PMID- 10669142
TI - Appearance of a stage-specific immunodominant glycoprotein in encysting Entamoeba
invadens.
AB - The appearance of cyst-specific proteins in encysting Entamoeba invadens and
their immunogenicity were examined by sodium dodecyl sulfate-polyacrylamide gel
electrophoresis and immunoblotting using an axenic encystation system in vitro. A
rabbit antiserum against trophozoites of E. invadens reacted with a number of
proteins of cysts after 1-4 days of incubation. Thus, a number of cyst proteins
remained antigenically unchanged as common antigens of the two forms after
transformation from trophozoites to cysts. A rabbit antiserum against cysts also
reacted with the trophozoite proteins as well as the cyst proteins. The most
interesting result was that the rabbit anticyst serum reacted predominantly with
an 88-kDa protein of cysts after 1 day of incubation. The 88-kDa protein reacted
with the anticyst serum absorbed with trophozoite proteins and was thus cyst
specific. The reactivity of the 88-kDa protein of cysts with the absorbed
anticyst serum decreased as encystation proceeded. When soluble and particulate
fractions prepared from cysts after 1 day of incubation were examined by
electrophoresis and immunoblotting, the 88-kDa protein that had reacted with the
absorbed anticyst serum was found to be present in the particulate fraction,
which was rich in cell-wall fragments, and stained with periodic acid-Schiff's
reagent, indicating that it is a glycoprotein. The results indicate that
encystation is accompanied by appearance of the cyst-specific 88-kDa
glycoprotein, which is immunodominant and most abundantly expressed in cysts
after 1 day of incubation and appears to be associated with the cyst wall.
PMID- 10669143
TI - High levels of factor VIII and venous thrombosis.
PMID- 10669144
TI - How much factor V is enough?
PMID- 10669145
TI - High plasma concentration of factor VIIIc is a major risk factor for venous
thromboembolism.
AB - BACKGROUND: Established risk factors, including deficiencies of protein C,
protein S or antithrombin and the factor V Leiden and prothrombin mutation, are
present in about one third of unselected patients with venous thromboembolism. In
addition to these inherited thrombophilic defects, elevated plasma levels of
factor VIIIc have been suggested to be important in the pathogenesis of
(recurrent) venous thromboembolism. The objective of this study was to assess the
relevance of factor VIIIc plasma concentration in consecutive patients with
venous thromboembolism. METHOD: We studied the prevalence of elevated plasma
levels of factor VIIIc in 65 patients with a proven single episode and in 60
matched patients with documented recurrent venous thromboembolism. The reference
group consisted of 60 age- and sex-matched patients who were referred for
suspected venous thromboembolism, which was refuted by objective testing and long
term clinical follow-up. To minimalize the influence of the acute phase, blood
was obtained at least 6 months after the thromboembolic event and results were
adjusted for fibrinogen and C-reactive protein. Factor VIIIc was re-determined
several years after the first measurement in a subset of patients to evaluate the
variability over time. To study a possible genetic cause, a family study was
done. FINDINGS: In the control, single and recurrent episode group, the
prevalences of plasma levels of factor VIIIc above 175 IU/dl (90th percentile of
controls) were 10% (95% CI: 4 to 21%), 19% (95% CI: 10 to 30%) and 33% (95% CI:
22 to 47%), respectively. For each 10 IU/dl increment of factor VIIIc, the risk
for a single and recurrent episode of venous thrombosis increased by 10% (95% CI:
0.9 to 21%) and 24% (95% CI: 11 to 38%), respectively. Both low and high plasma
levels of factor VIIIc were consistent over time (R = 0.80, p = 0.01). A family
study indicated a high concordance for elevated factor VIIIc plasma
concentrations among first degree family members. Adjustment for fibrinogen, C
reactive protein and known thrombophilic risk factors did not change the observed
association of elevated factor VIIIc with thrombosis. INTERPRETATION: Elevated
plasma levels of factor VIIIc are a significant, prevalent, independent and dose
dependent risk factor for venous thromboembolism. It also predisposes to
recurrent venous thromboembolism.
PMID- 10669146
TI - Elevation of FVIII: C in venous thromboembolism is persistent and independent of
the acute phase response.
AB - Recent literature has suggested a role for elevated FVIII:C in venous
thromboembolic disease (VTED). However since FVIII:C is known to rise in response
to an acute phase reaction, it is difficult to determine whether the increased
FVIII:C precedes the thrombosis or represents a secondary reactive phenomenon. In
an attempt to address this question, we followed 35 patients with confirmed VTED,
raised FVIII:C level (>1.5 iu/ml) and no other thrombotic tendency. Serial
measurements of FVIII:C, vWF:Ag, C-reactive protein and fibrinogen were
performed. We hypothesized that a persistent increase in FVIII:C in the absence
of any other measures of ongoing acute phase response, would support the idea
that elevation of FVIII:C is a constitutional phenomenon. Of this initial group,
94% continued to have an elevated FVIII:C level throughout the period of follow
up (median 8 months; range 3 to 39 months), with no significant difference
between the FVIII:C levels determined at first estimation and those obtained
during follow up (p = 0.58). Conversely, only 18% had evidence of an acute phase
reaction when first assessed, and nonparametric ranking analysis demonstrated no
correlation between FVIII:C and either C-reactive protein or fibrinogen (p =
0.315 and 0.425 respectively).We conclude that increased FVIII:C levels following
VTED are persistent, independent of the acute phase reaction, and thus may
represent a constitutional risk factor for VTED.
PMID- 10669147
TI - Prevention of venous thromboembolism in internal medicine with unfractionated or
low-molecular-weight heparins: a meta-analysis of randomised clinical trials.
AB - BACKGROUND: The prevention of venous thromboembolic disease is less studied in
medical patients than in surgery. METHODS: We performed a meta-analysis of
randomised trials studying prophylactic unfractionated heparin (UFH) or low
molecular-weight heparin (LMWH) in internal medicine, excluding acute myocardial
infarction or ischaemic stroke. Deep-vein thrombosis (DVT) systematically
detected at the end of the treatment period, clinical pulmonary embolism (PE),
death and major bleeding were recorded. RESULTS: Seven trials comparing a
prophylactic heparin treatment to a control (15,095 patients) were selected. A
significant decrease in DVT and in clinical PE were observed with heparins as
compared to control (risk reductions = 56% and 58% respectively, p <0.001 in both
cases), without significant difference in the incidence of major bleedings or
deaths. Nine trials comparing LMWH to UFH (4,669 patients) were also included. No
significant effect was observed on either DVT, clinical PE or mortality. However
LMWH reduced by 52% the risk of major haemorrhage (p = 0.049). CONCLUSIONS: This
meta-analysis, based on the pooling of data available for several heparins, shows
that heparins are beneficial in the prevention of venous thromboembolism in
internal medicine.
PMID- 10669148
TI - Factor II G20210A and factor V G1691A gene mutations and peripheral arterial
occlusive disease.
AB - BACKGROUND: G to A mutations at positions 20210 of the prothrombin gene (F2) and
1691 of the factor V gene (F5) are established risk factors for venous
thrombosis. Several factors associated with coagulation and/or fibrinolysis have
been associated with arterial occlusive disease, but the role of F2 20210A and F5
1691A for arterial occlusive disease remains unclear. OBJECTIVE: To investigate
if F2 20210A and F5 1691A are associated with peripheral arterial occlusive
disease (PAOD). METHODS AND RESULTS: We analyzed the prevalence of F2 20210A and
F5 1691A alleles in 336 patients with documented PAOD at Fontaine stage II-IV and
300 controls without vascular disease. Allele frequencies in patients and
controls were 0.013 and 0.022 for F2 20210A, and 0.042 and 0.045 for F5 1691,
respectively, both differences being not statistically significant. CONCLUSION:
Our data suggest that mutations F2 G20210A and F5 G1691A are not associated with
PAOD.
PMID- 10669149
TI - A common polymorphism flanking the ATG initiator codon of GPIb alpha does not
affect expression and is not a major risk factor for arterial thrombosis.
AB - The platelet membrane glycoprotein (GP) Ib alpha plays a key role in the initial
formation of thrombi. Polymorphisms (VNTR and HPA-2) in this receptor are
associated with increased risk of coronary heart disease (CHD) and cerebral
vascular disease (CVD). We investigated whether a recently described polymorphism
(S/R), due to a single base change (T-->C) five nucleotides upstream the
initiator codon of GPIb alpha, might influence the expression of the protein, and
be implicated in the development of arterial thrombosis. One hundred and thirty
nine healthy individuals provided blood samples for DNA analysis of platelet GPIb
alpha polymorphisms, and for flow cytometric analysis of the surface expression
of the receptor. A group of 20 S/R normal individuals and an identical number of
S/S participants, age and sex matched, was investigated for the analysis of the
density of various platelet receptors. The distribution of the S/R polymorphism
was also analyzed in two case/control studies including 104 CVD patients, 101 CHD
patients, and one control age, sex, and environmental risk factors matched for
each case patient. Surface density of GPIb alpha showed no wide variations
between individuals, was not influenced by the presence of S or R alleles, nor
associated with the VNTR or HPA-2 polymorphisms. The prevalence of the S/R
genotype among CVD and CHD patients was not distinct from that in the control
groups. We conclude that the S/R polymorphism of GPIb alpha, flanking the
initiator codon of the receptor, does not seem to be associated with surface
levels of the protein, and is not an independent risk factor for arterial
thrombosis.
PMID- 10669150
TI - Impaired procoagulant-anticoagulant balance during hormone replacement therapy? A
randomised, placebo-controlled 12-week study.
AB - In this randomised, placebo-controlled 12-week study, sixty healthy
postmenopausal women received either placebo (N = 16) or daily 2 mg micronised
oestradiol, either unopposed (N = 16, E2 group) or combined with a progestagen
for 14 days of each cycle (N = 28, E2+P group). RESULTS: As compared to placebo,
plasma levels of AT III were reduced only in the E2 group (approximately 28%),
plasma levels of protein C decreased only in the E2+P group (approximately 4%)
and plasma levels of protein S decreased in both the E2 and E2+P group
(approximately 21%). In both the E2 and E2+P groups, the plasma levels of factor
VII (antigen and activity) showed a borderline significant increase
(approximately 10%), whereas no significant change was observed in active factor
VII. Plasma levels of tissue-type plasminogen activator (approximately 22%),
urokinase plasminogen activator (approximately 25%) and plasminogen activator
inhibitor type-1 (approximately 43%) decreased in the E2 and E2+P groups, whereas
those of plasminogen increased (approximately 12%). Treatment was associated with
an increase in levels of prothrombin fragment 1+2 (approximately 31%), but levels
of thrombin-antithrombin III complexes, and of plasmin-alpha2-antiplasmin
complexes and total fibrin(ogen) degradation products did not change
significantly. CONCLUSION: Short-term E2 and E2+P treatment is associated with a
shift in the procoagulant-anticoagulant balance towards a procoagulant state. A
substantial proportion of women do not have a net increase in fibrinolytic
activity. These data may be relevant in explaining the increased risk of venous
thromboembolism associated with ERT and HRT, and possibly also in explaining the
negative results of the Heart and Estrogen/progestin Replacement Study.
PMID- 10669151
TI - Inherited macrothrombocytopenia with distinctive platelet ultrastructural and
functional features.
AB - We report a family with inherited macrothrombocytopenia and characteristic large
membrane complexes in the platelets. Two affected subjects had platelet counts of
40 and 65 x 10(9)/L respectively as assessed by contrast phase microscopy.
Ultrastructural studies revealed giant spheroid platelets with characteristic
large membrane complexes and/or giant vacuoles containing platelet organelles.
Immunohistochemical studies of actin and tubulin showed a disorganization of the
microtubule and actin systems. These abnormalities were absent in leukocytes,
indicating a platelet-specific cytoskeleton disorder. Platelet autoantibodies
were repeatedly absent. Nevertheless, in the peripheral blood we observed several
figures of platelet phagocytosis by macrophages and neutrophils. The in vitro
aggregometric response of platelets to ADP, collagen, thrombin, ristocetin was
present, but shape change was absent. The urinary excretion of thromboxane A2
metabolites of the affected subjects were approximately 2 standard deviations
above control values, in spite of a reduced maximal biosynthetic capacity of
thromboxane from giant platelets assessed in vitro during whole blood clotting.
This inherited platelet disorder shows structural and functional features which
allow to distinguish it from other syndromes associated with giant platelets. We
also propose to include ultrastructural and cytoskeletal studies in the diagnosis
as well as in the classification of inherited giant platelet disorders.
PMID- 10669152
TI - Screening for autoimmune markers is unnecessary during follow-up of adults with
autoimmune thrombocytopenic purpura and no autoimmune markers at onset.
AB - In an attempt to evaluate the frequency of autoimmune markers in autoimmune
thrombocytopenic purpura (AITP) and to determine if autoimmune markers in
patients with isolated AITP were associated with particular disease
manifestations, we analyzed records of 122 consecutive adults with AITP. Twenty
nine patients (24%) had significant titers of one or several autoimmune markers
at AITP onset. Among them, 16 (13%) had antinuclear antibodies. The presence of
autoimmune markers did not correlate with presenting feature, response to
treatment or long-term outcome of AITP. Six patients (5%) developed seven
autoimmune diseases during follow-up, comprising systemic lupus erythematosus, an
antiphospholipid syndrome, autoimmune haemolytic anemia (n = 2), Grave's disease,
Hashimoto's disease and primary biliary cirrhosis. At AITP onset, three of these
patients had isolated biological markers of the autoimmune disease they later
developed. The annual average incidence rate of autoimmune diseases was 1% per
patient-year in the entire group and 0.4% in the group of patients with no
autoimmune markers at AITP onset. This low rate is probably due to careful
assessment at diagnosis for concomitant overt autoimmune disease. We recommend
extensive screening for autoimmune markers at AITP onset, and careful follow-up
of patients with autoimmune markers. Routine screening for autoimmune markers
during AITP follow-up is not necessary for patients with no autoimmune markers at
AITP onset. Systemic lupus erythematosus (SLE) and other autoimmune disorders can
complicate autoimmune thrombocytopenic purpura (AITP) or be diagnosed
concomitantly with otherwise unremarkable AITP (1, 2). However, the frequency and
prognostic value of isolated autoimmune markers (i.e. not associated with an
autoimmune disorder), particularly antinuclear antibodies (ANA) at AITP onset or
during follow-up is controversial (3-8). For example, the committee organized by
George et al. (9) to write guideline on the diagnosis and treatment of AITP
stated that the search for ANA and lupus anticoagulant were of "uncertain
appropriateness at diagnosis and during follow-up". In an attempt to help
practicians to make decisions, we analyzed the frequency of autoimmune markers
and autoimmune disorders at onset and during the follow-up in 122 adults with
AITP and no overt autoimmune disease at diagnosis. These consecutive patients
were followed by the same physician for a mean period of 6 years, and had routine
screening tests for autoimmune markers and disorders at onset, before steroid
therapy, and regularly during follow-up.
PMID- 10669153
TI - Fluvastatin decreases soluble thrombomodulin in cardiac transplant recipients.
AB - We conducted a randomized, placebo controlled, double-blind, cross-over study, to
assess the effects of a 4-week fluvastatin therapy on plasma markers of
endothelial activation or injury in 20 transplanted heart recipients. The levels
of thrombomodulin and von Willebrand factor antigen were higher at baseline in
cardiac transplant recipients than in age and sex-matched healthy controls.
Plasma total cholesterol showed a 21% reduction on fluvastatin therapy (p =
0.0001). Fluvastatin treatment had no significant effect on creatininemia, plasma
cyclosporine, PAI-1 antigen, PAI-1 activity, tPA antigen, and Von Willebrand
factor. However, fluvastatin produced a significant decrease of plasma
thrombomodulin (66.7 ng/ml on placebo versus 58.8 ng/ml on fluvastatin, p
<0.001), suggesting a rapid improvement of endothelial injury in these patients.
PMID- 10669154
TI - The management of oral anticoagulant therapy: the patient's point of view.
AB - The aims of this study were to investigate on the general adhesion of the
patients to oral anticoagulant therapy, and particularly on the quality of life
of our patients, the doctor-patient relationship and the Centre-patient
relationship. For this purpose we administered a questionnaire containing 17 main
questions each with a maximum of 4 secondary questions. The questionnaire was
administered to two groups of 127 and 137 oral anticoagulated patients (127 males
and 137 females, mean age 55 +/- 19 years), followed at two Anticoagulation
Clinics, in two Italian cities, Cagliari (Sardinia) and Padua (North East Italy).
The cities differed in the number of patients monitored and the management
modalities of anticoagulation. The results show that oral anticoagulant therapy
does not limit the life-style of the patients. Only 11% of the patients complain
of limitations to their daily life. Fifty-two percent believe their health has
improved, and 87% are not afraid of negative consequences. The doctor-patient
relationship is considered very important by 96% of patients. Seventy-eight
percent refer to the Anticoagulation Clinic also for other health problems, 93%
consider it important to be assessed by the doctor at the Anticoagulation Clinic,
while 83% believe the doctor should always hand out the results personally. We
conclude that in general oral anticoagulant therapy is accepted by the majority
of patients, in spite of the need for periodic monitoring. The doctor-patient
relationship should be taken into account, even in the case of a monitored,
computer-assisted method of dose-adjustment.
PMID- 10669155
TI - Hemostatic parameters and platelet activation marker expression in cyanotic and
acyanotic pediatric patients undergoing cardiac surgery in the presence of
tranexamic acid.
AB - We have investigated hemostatic parameters including platelet activation in 56
pediatric patients with or without cyanosis undergoing cardiopulmonary bypass
(CPB) and cardiac surgery to repair congenital defects. Patients were
participants in a study assessing the effects of tranexamic acid on surgery
related blood loss. Parameters monitored included blood loss, prothrombin F1.2,
thrombin-antithrombin complexes, t-PA, PAI-1, plasminogen, fibrin D-dimer, and
plasma factor XIII. Additionally, flow cytometry monitored platelet degranulation
(P-selectin or CD63), as well as surface-bound fibrinogen, von Willebrand factor
and factor XIIIa. Cyanotic patients had evidence of supranormal coagulation
activation as both fibrin D-dimer and PAI-1 levels were elevated prior to
surgery. While the extent of expression of P-selectin or CD63 was not
informative, platelet-associated factor XIIIa was elevated in cyanotic patients
at baseline. In both patient groups, CPB altered platelet activation state and
coagulation status irrespective of the use of tranexamic acid.
PMID- 10669156
TI - Purification and characterization of factor VII inhibitor found in a patient with
life threatening bleeding.
AB - We recently observed a patient with acquired inhibitor-induced F.VII deficiency
whose plasma level of F.VII was < 1.0%. However, the biochemical nature of the
inhibitor has not yet been clarified. In the present study, we purified the F.VII
inhibitor from the patient's plasma by using activated F.VII (F.VIIa)-conjugated
gel and characterized the inhibitor. The results showed that the inhibitor
comprised two kinds of antibodies: one was eluted with EDTA (antibody 1) and the
other with glycine-HCl buffer (pH 2.3) (antibody 2) from the F.VIIa affinity gel.
SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting analysis of
these inhibitors demonstrated that both antibodies had features of immunoglobulin
G1 (IgG1) with kappa and lambda-light chains. Antibody 1 bound to the immobilized
F.VIIa with a high affinity in the presence of calcium ion, while antibody 2
bound to the F.VIIa very weakly and the binding was independent of calcium ion.
Immunoblotting analysis demonstrated that antibody 1 bound to the light chain of
F.VIIa after reduction with 2-mercaptoethanol, while it did not react with either
the gamma-carboxyglutamic acid (Gla)-domainless light chain of F.VIIa or the
heavy chain with the protease domain. Antibody 1 markedly inhibited the activity
of tissue factor-F.VIIa complex. Based on these observations, it is suggested
that F.VIIa autoantibody (antibody 1) recognizes the calcium-dependent
conformation within or near the Gla domain and inhibits F.VIIa activity by
interacting with the light chain.
PMID- 10669157
TI - The half-life of infused factor VIII is shorter in hemophiliac patients with
blood group O than in those with blood group A.
AB - A considerable inter-individual variation in half-life of infused factor VIII is
observed among patients with hemophilia A. The factors contributing to this wide
range in factor VIII half-life are not known in detail. We analysed the
pharmacokinetics of infused factor VIII in 32 patients with hemophilia A,
comprising 20 brothers from 10 families, 3 and 4 brothers from 2 families, and 5
patients from 5 single families, respectively. Multiple linear regression
analysis was used to assess the effect of several variables on factor VIII half
life. We found that the pre-infusion von Willebrand factor antigen levels
(vWF:Ag) were positively correlated with factor VIII half-life (r = 0.52, p =
0.002), i.e., each variable was associated with about 27% of the variance of the
other. In fraternal pairs, familial clustering was significant for ABO blood
group (p < 0.001), but could not be detected for factor VIII half-lives or pre
infusion vWF:Ag levels. vWF:Ag level (p = 0.001) and ABO blood group (p = 0.003)
significantly determined factor VIII half-life, whereas age, length, bodyweight,
the presence or absence of a factor VIII gene inversion, and Rhesus phenotype did
not. Patients with blood group O exhibited a statistically significant shorter
factor VIII half-life than patients with blood group A (15.3 versus 19.7 h,
respectively) (p = 0.003). Patients with blood group A and O differ in respect to
the presence of anti-A antibodies in the latter. It is possible that these anti-A
antibodies interact with endogenous vWF, thus affecting the half-life time of the
factor VIII/vWF complex.
PMID- 10669158
TI - Rescue of fatal neonatal hemorrhage in factor V deficient mice by low level
transgene expression.
AB - Factor V (FV) is a critical component of the coagulation cascade. FV-deficient
patients suffer moderate to severe bleeding, though residual FV activity is
detectable in nearly all cases. In contrast, FV-deficient mice die either during
mid-embryogenesis, or of massive perinatal hemorrhage. In order to examine the
requirements for FV in murine embryogenesis and hemostasis, we generated
transgenic mouse lines expressing a Fv minigene under control of either the
tissue-specific albumin (Malb) or rat platelet factor 4 (Rpf4) promoter. A total
of 12 Malb and 3 Rpf4 lines were analyzed. Though expression in the target tissue
was detectable in most lines by RT-PCR, only low levels of transgene expression
were achieved (<3% of endogenous Fv in all lines). Despite a low level of Fv
transgene expression, rescue of the lethal Fv-/- phenotype was observed with one
of the Malb transgenic (Tg+) lines. However, rescue appeared to be incomplete
with continued loss of >1/2 of expected Tg+,Fv-/- mice in early embryogenesis.
Rescued Tg+,Fv-/- mice have undetectable FV (<0.1%) in both plasma and platelet
compartments, but survive the perinatal period and mature to adulthood without
spontaneous hemorrhage. We conclude that FV present at <0.1% is sufficient to
support postnatal survival. Failure of the Malb transgene to rescue the
midembryonic block suggests that FV expression is required during mammalian
development at higher levels or with a different tissue-specific or temporal
pattern. Taken together, these data may explain the observation of residual FV
activity in most human FV-deficient patients due to early embryonic lethality in
those absolutely deficient, and suggest that minimal levels of FV expression,
below the level of detection, also may be sufficient to support survival in
humans.
PMID- 10669159
TI - Structural basis for hemophilia A caused by mutations in the C domains of blood
coagulation factor VIII.
AB - Three dimensional homology models for the C1 and C2 domains of factor VIII
(FVIII) were generated. Each C domain formed a beta-sandwich, and C1 was
covalently connected to C2 in a head-to-head orientation. Of the >250 missense
mutations that cause FVIII deficiency and hemophilia A, 34 are in the C domains.
We used the FVIII C1-C2 model to infer the structural basis for the pathologic
effects of these mutations. The mutated residues were divided into four
categories: 15 conserved buried residues that affect normal packing of the
hydrophobic side chains, 2 non-conserved buried residues that affect structure,
11 conserved exposed residues and 6 non-conserved exposed residues. The effects
of all 34 missense mutations can be rationalized by predictable disruptions of
FVIII structure while at most four mutations (S2069F, T2154I, R2209Q/G/L and
E2181D) may affect residues directly involved in intermolecular interactions of
FVIII/VIIIa with other coagulation factors or vWF.
PMID- 10669160
TI - Thirty-three novel mutations in the protein C gene. French INSERM network on
molecular abnormalities responsible for protein C and protein S.
AB - We analyzed the protein C gene (PROC) with the denaturing gradient gel
electrophoresis (DGGE) scanning strategy in a series of 129 patients with
suspected protein C (PC) deficiency (93 with low plasma PC levels and 36 with
borderline level). At least one sequence variation was found in 104 of the 129
patients. Thirty-nine sequence variations (found in 72 patients) were already
reported detrimental mutations. Thirty-three were novel sequence variations, of
which 19 (found in 25 patients) were probably detrimental. Five novel mutations
(A1T, R9H, S11R, S12R and K193Q) were associated with qualitative plasma PC
deficiency, suggesting or confirming the functional importance of amino acids at
these positions. This strategy confirmed the diagnosis of inherited PC deficiency
in 79/93 (84.9%) patients with low plasma PC levels and 14/36 (38.8%) patients
with borderline values. In order to explain abnormal PC levels observed in
patients who did not carry detrimental mutations, screening for the -1654C/T and
1641A/G PROC promoter polymorphisms known to influence plasma PC concentrations
was performed. The frequency of the CG allele associated with lower PC
concentrations was slightly but not significantly lower in 82 heterozygotes for
detrimental PROC gene mutations than in 36 patients with no identified
detrimental mutations.
PMID- 10669161
TI - Characterization of transgenic mice that secrete functional human protein C
inhibitor into the circulation.
AB - Protein C inhibitor (PCI) is a heparin binding serine protease inhibitor in
plasma, which exerts procoagulant activity by inhibiting thrombomodulin-bound
thrombin or activated protein C (APC). Since the role of PCI in vivo is largely
unknown we generated genetically modified mice with expression of human PCI mRNA
in hepatocytes only. Three transgenic lines have been characterized. Transgenic
mice did not show gross developmental abnormalities. Two lines showed a
pericentral and one line showed a periportal expression pattern of human PCI mRNA
in the liver. Genetically modified mice secreted a functional transgenic protein
into the circulation (3-5 microg/ml plasma in heterozygous mice and 10 microg/ml
in homozygous mice), which inhibited human APC activity in the presence of
heparin. Interestingly, transgenic mice in which human PCI was expressed
periportally in the liver had the highest specific activity. Endogenous mouse PCI
mRNA could only be detected in the male and female reproductive system, but not
in the liver, indicating that endogenous PCI levels in the circulation are low or
even absent in mice. These results demonstrate that the human PCI transgenic mice
are a suitable model for studying the in vivo role of PCI in blood coagulation.
PMID- 10669163
TI - A reliable and reproducible ELISA method to measure ristocetin cofactor activity
of von Willebrand factor.
AB - The ristocetin induced binding of vWF to GPIb, which is routinely tested in a
platelet agglutination assay, can be reproducibly studied in an ELISA where
plasma vWF binds to a captured rGPIb alpha-fragment (His1-Val289) in the presence
of ristocetin. This binding is specific since the vWF-GPIb interaction could (i)
be blocked by inhibitory anti-GPIb or anti-(vWF A1 domain) monoclonal antibodies
(mAbs) and (ii) be enhanced by an anti-vWF mAb that also facilitates ristocetin
induced platelet agglutination. Further studies were undertaken to determine
whether the test could be used to differentiate vWF from patients with different
types of von Willebrand's disease. The median vWF:RiCof activity in controls (n =
24) was 0.75 U/ml, in type 1 vWD patients (n = 17) 0.28 U/ml, in type 2A (n = 18)
0.055 U/ml, in type 2B (n = 4) 0.094 U/ml and in type 3 (n = 3) <0.0005 U/ml.
Moreover, the values correlated well with those obtained from the vWF:RiCof
agglutination assay (r = 0.873). The vWF:RiCof-ELISA has several advantages: the
use of a recombinant fragment instead of donor platelets results in a more
reproducible test with a low inter- and intra-assay variability (<14% CV), the
test can further be readily automated and for a single determination, only
minimal amounts of patient plasma are required (8 microl).
PMID- 10669162
TI - Homozygosity for the protein S Heerlen allele is associated with type I PS
deficiency in a thrombophilic pedigree with multiple risk factors.
AB - The multifactorial character of thrombotic disease is shown in a Spanish pedigree
in which the propositus, with recurrent deep vein thrombosis, inherited the
factor V R/Q506 mutation, the prothrombin 20210G/A variant and type III Protein S
deficiency. Among 14 relatives carrying one or two of these three risk factors,
thrombosis is present in a heterozygote for R/Q506 and in another for 20210G/A,
who also had slightly positive antiphospholipid antibodies. Type I PS deficiency
was also found in a young asymptomatic woman. PROS1 analysis showed coexistence
of type III and type I PS deficiency to be associated with heterozygosity and
homozygosity, respectively, for the P460 or PS Heerlen allele of the S/P460
variant. Analysis of PS values in this and other pedigrees segregating this
variant revealed that not only free but also mean total PS levels are slightly
but significantly lower in the SP460 heterozygotes than in the SS460 homozygotes.
These findings strongly suggest a role of the P460 variant in the expression of
the PS deficient phenotype.
PMID- 10669164
TI - Induction of tissue factor procoagulant activity in myelomonocytic cells
inoculated by the agent of human granulocytic ehrlichiosis.
AB - Human granulocytic ehrlichiosis (HGE) is a recently recognized rickettsial tick
borne febrile illness that may occasionally be complicated by coagulopathy. The
agent of HGE (aHGE) is an obligate intracellular pathogen, which replicates in
endosomes within neutrophils and their precursors. We hypothesized that aHGE
might cause DIC via induction of monocyte tissue factor procoagulant activity (TF
PCA). Peripheral blood mononuclear cells (PBMNC) and HL-60 cells were used to
model the effect of aHGE infection on monocytes/macrophages. Mononuclear cells
inoculated with aHGE in vitro demonstrated approximately a 12-15-fold increase in
TF PCA, with peak activity occurring at 8-12 h. HL-60 cells inoculated with aHGE
also manifested a 4-6 fold induction of TF PCA, with maximal activity occurring
at about 8 h. By comparison, E. Coli lipopolysaccharide (LPS) also induced an
increase in TF PCA of an equivalent magnitude, and with a similar time course.
Induction of TF did not require inoculation of HL-60 cells with live organism,
since heat-inactivated aHGE still stimulated TF PCA expression in the target
cells. Furthermore, filtered supernatants from heat-inactivated organisms induced
TF PCA suggesting that the effect is due to a soluble mediator produced by the
organism. Although aHGE is a gram negative organism, the soluble mediator did not
appear to be classic endotoxin in that the supernatants tested negative for
endotoxin by the Limulus Amoebocyte assay, and polymixin had no inhibitory effect
on aHGE supernatants. We conclude that aHGE induces cells of the myelo-monocytic
lineage to synthesize TF, which may contribute to the clinical coagulopathy that
can be observed in this condition. An atypical soluble mediator or cellular
component of the organism appears to be critically important in TF induction by
aHGE.
PMID- 10669165
TI - Glycoprotein Ib-binding protein from the venom of Deinagkistrodon acutus--cDNA
sequence, functional characterization, and three-dimensional modeling.
AB - Agkicetin-C, a potent glycoprotein Ib antagonist from the venom of the Chinese
pit viper, Deinagkistrodon acutus, has been purified and characterized (5). It is
a disulfide-linked heterodimer containing subunits of 132 and of 123 amino acid
residues. Herein, the complete amino acid sequences were resolved by cloning and
nucleotide sequencing of the cDNAs. The sequences of its subunits are homologous
to those of other snake venom proteins of the C-type (Ca2+-dependent) lectin
superfamily. A three-dimensional model of agkicetin-C was constructed based on
the crystal structure of habu coagulation factor IX/X-binding protein. By careful
alignment of all the related sequences available and comparing the 3D-model of
agkicetin-C with structures of other homologous proteins of different functions,
some variable residues of agkicetin-C were identified, which possibly are
responsible for the specificity of this distinct subtype of the C-type lectin
like venom proteins.
PMID- 10669166
TI - Collagen binding assay for von Willebrand factor (VWF:CBA): detection of von
Willebrands Disease (VWD), and discrimination of VWD subtypes, depends on
collagen source.
AB - A large number of different collagen preparations [n = 21] have been assessed for
their ability to both detect von Willebrands Disease (VWD), and discriminate
different VWD subtypes. Collagen preparations were tested at a range of
concentrations and included: Type I, III and IV, and various mixtures of these,
as aqueous supplied preparations and/or reconstituted from bulk lyophilised
stock. Tissue sources for collagens ranged from human placenta to calf skin to
equine tendon. Three of the collagen preparations tested did not support von
Willebrand factor (VWF) binding in an ELISA process (therefore unable to detect
VWD). The ability of the remaining preparations to detect VWF was variable, as
was their ability to discriminate VWD subtypes. Detection of VWF and
discrimination of VWD subtypes was not mutually inclusive. Thus, some collagen
preparations provided excellent detection systems for VWF, but comparatively
poorer discrimination of Type 2 VWD, while others provided good to acceptable
detection and discrimination. Subtype discrimination was also dependent on the
collagen concentration, and some batch to batch variation was evident with some
preparations (particularly Type I collagens). Overall, best discrimination was
typically achieved with Type I/III collagen mixtures, or Type III collagen
preparations (where effectiveness was highly dependent on concentration). Good
discrimination was also achieved with a commercial Type III collagen based
VWF:CBA kit method. Results of the various 'VWF:CBA assays' are also compared
with those using the Ristocetin Cofactor (VWF:RCof) assay (by platelet
agglutination) and that using a commercial 'VWF:RCof-alternative/activity' ELISA
procedure. These latter methodologies tended to be less sensitive to VWF
discordance when compared to that detected by the majority of the VWF:CBA
procedures.
PMID- 10669167
TI - Von Willebrand Disease type 2M "Vicenza" in Italian and German patients:
identification of the first candidate mutation (G3864A; R1205H) in 8 families.
AB - Von Willebrand disease type 2M "Vicenza" (VWD 2M V) is characterised by autosomal
dominant inheritance, low von Willebrand factor (VWF) and the presence of
"supranormal" multimers in plasma. This specific phenotype has been described in
Italian and recently also in German patients. The molecular defect is linked to
the VWF gene. However, no specific mutations have been identified until now. We
analysed the complete coding region and adjacent intron sequences of the VWF gene
in Italian families in comparison to German families with VWD 2M V by a PCR-based
mutation screening, combined with SSC- and heteroduplex-analysis of exons 2
through 52, followed by direct sequencing. We identified the first heterozygous
candidate mutation (G3864A; R1205H) in all affected members of the 7 Italian
families and in 1 German patient but not in the unaffected family members nor on
100 chromosomes of normal subjects, suggesting a causal relationship between the
mutation and the phenotype. Haplotype identity, with minor deviations in one
Italian family, suggests a common but not very recent genetic origin of R1205H.
PMID- 10669168
TI - Nucleotide sequence of the gene encoding murine tissue factor pathway inhibitor
2.
AB - Tissue factor pathway inhibitor-2 (TFPI-2), also known as placental protein 5, is
a 32 kDa extracellular matrix-associated serine proteinase inhibitor consisting
of three tandemly-arranged Kunitz-type domains. Two overlapping genomic clones
containing sequences encoding murine TFPI-2 were isolated from a lambda FIXII 129
SVJ mouse genomic library, and the complete nucleotide sequence of the gene was
determined. The murine TFPI-2 gene spans approximately 9.3 kilobases and consists
of five exons and four introns. The nucleotide sequences surrounding all the exon
intron boundaries are highly conserved and obey the GT-AG rule. Each Kunitz-type
domain is encoded by a single exon, similar to that observed for other Kunitz
type proteinase inhibitors. A total of 1,577 bp of the 3'-flanking region
contains a probable polyadenylation site (ATTAAA) at +5,759 and an apparent
cleavage or termination site (CATTG) at +6,170. The 5'-flanking region of the
murine TFPI-2 gene contains a prototypical TATA box, a GC box and two CAAT boxes.
In addition, several candidate transcription factor binding sites responsible for
placenta-, endothelial cell-, and smooth muscle cell-specific expression of the
TFPI-2 gene were also identified.
PMID- 10669169
TI - The effect of monoclonal anti-human-platelet antibodies on platelet kinetics in a
baboon model: IgG subclass dependency.
AB - We assessed the in vivo effect of six intact anti-human antiplatelet antibodies
of two major IgG subclasses on platelet kinetics in baboons. Five of the six
antibodies tested caused thrombocytopenia of varying degree when injected at a
precalculated threshold value. An agglutinating IgG1 antibody (MA-8L4A12) caused
a long-lasting, mild thrombocytopenia with a predominant uptake of radiolabelled
platelets in the spleen, while the four IgG2 antibodies tested (MA-13G8E1, MA
2M5A6, MA-21K2E8 and MA-22M10) caused a severe, transient thrombocytopenia with
uptake of platelets in the liver. Two of the IgG2 antibodies (MA-13G8E1 and MA
2M5A6) caused platelet activation and aggregation in vitro, whilst the other two
did not elicit a platelet aggregation response. The platelet survival time was
shortened with all five of the thrombocytopenia-inducing antibodies, while only
one antibody (MA-2M5A6) had a significant effect on the bleeding time. This study
indicates that the IgG subclasss may be a determining factor in the outcome of
platelet sequestration in immune-induced thrombocytopenia.
PMID- 10669170
TI - Platelets release their lysosomal content in vivo in humans upon activation.
AB - Platelets contain, besides alpha- and delta-granules, lysosomes which store
glycohydrolases able to degrade glycoproteins, glycolipids and
glycosaminoglycans. While several studies have shown that alpha- and delta
granule secretion takes place "in vivo" in humans upon platelet activation, no
data are available on the "in vivo" release of lysosomes. We have studied the
release of platelet lysosomal contents "in vivo" in healthy volunteers at a
localized site of platelet activation by measuring markers of lysosomal secretion
in the blood oozing from a skin wound inflicted for the measurement of the
bleeding-time. The levels of beta-N-acetylhexosaminidase (Hex) were 13.1 +/- 0.85
mU/ml in bleeding-time blood and 10.2 +/- 0.66 mU/ml in plasma (p <0.001). Hex in
serum was 16.4 +/- 0.72 mU/ml. The levels of beta-galactosidase were also higher
in bleeding-time blood than in plasma (0.85 +/- 0.07 mU/ml vs 0.4 +/- 0.05 mU/ml,
p <0.001). In bleeding-time blood collected at one minute intervals, Hex rose
progressively consistent with ongoing platelet activation and flow-cytometry
showed a progressive increase of the expression of LIMP and LAMP-2, two lysosomal
associated proteins. In conclusion, our data demonstrate that platelet lysosomal
glycohydrolases are released "in vivo" in humans upon platelet activation.
PMID- 10669171
TI - Determination of the putative binding sites for thrombin receptor activating
peptide through a hydropathic complementary approach.
AB - Putative binding sites in a platelet thrombin receptor (PAR-1) for the activating
peptide SFLLRNPNDKYEPF (AP) and for the bradykinin analogue MKRPPGFSPFRSSRIG were
revealed using a computer program for identifying complementary peptide segments.
The program is based on the assumption that interactions of agonist's peptides
and protein's receptors can be elucidated by complementary average hydropathies
as much as possible equal by size and opposite by sign. Some of the computer
found putative binding sites were close to the supposed AP-PAR-1 contacts in the
amino-terminal exodomain and in the second extracellulary loop of PAR-1. Peptides
complementary to these binding sites were also computer-designed and were
synthesized. They mostly inhibited the aggregation of gel filtered platelets by
thrombin (0.025 U/mL) with IC50 in a high micromolar range of concentrations. The
peptide complementary to site L258-Y269 of PAR-1 induced aggregation of gel
filtered platelets with EC50 = 98 [micromol/L] related to thrombin (0.025 U/mL)
aggregation response.
PMID- 10669172
TI - Prevention of deep vein thrombosis after hip replacement.
PMID- 10669173
TI - Further evidence that activated protein C resistance affects protein C coagulant
activity assays.
PMID- 10669174
TI - Is there a role for anti-phospholipid-binding protein antibodies in the
pathogenesis of thrombosis in Behcet's disease?
PMID- 10669175
TI - Transient lupus anticoagulants in children: stepwise disappearance of diagnostic
features.
PMID- 10669176
TI - GPIaIIa as a candidate target for anti-platelet autoantibody occurring during
valproate therapy and associated with peroperative bleeding.
PMID- 10669177
TI - Agreement of D-dimer results measured by a rapid ELISA (VIDAS) before and after
storage during 24h or transportation of the original whole blood samples.
PMID- 10669178
TI - Genotype distribution of the 46C/T polymorphism of coagulation factor XII in the
Japanese population: absence of its association with ischemic cerebrovascular
disease.
PMID- 10669179
TI - Factors affecting prescribing of the newer antidepressants.
AB - OBJECTIVE: To survey various prescriber types and specialties to determine
whether differences exist in prescribing patterns for the newer antidepressants.
DESIGN, SETTING, AND PARTICIPANTS: A survey about prescribing of the newer
antidepressants was mailed to 1,500 New York state licensed prescribers who were
randomly selected from membership rosters. Nurse practitioners; physician
assistants and physicians in family medicine, primary care, general practice, and
internal medicine; and psychiatrists were included. MAIN OUTCOME MEASURES:
Prescriber responses regarding factors involved with choosing among the newer
antidepressants. RESULTS: A total of 508 surveys (36%) were returned, of which
398 (29%) were acceptable for analysis. In choosing among the newer
antidepressants, most prescribers ranked patient diagnosis and past success as a
high priority, and free drug samples and drug-representative detailing as a low
priority. The majority of each prescriber type preferred fluoxetine for major
depression and depression associated with fatigue; paroxetine for concomitant
anxiety and depression, as well as for panic disorder; and sertraline for
geriatric patients and patients with suicidal ideation. Differences existed
between the prescriber groups when asked whether prescribing habits for the newer
antidepressants were based on familiarity with a particular agent (p = 0.0009)
and on labeled indications (p = 0.002). CONCLUSIONS: This is the first study to
demonstrate prescribing preferences for the newer antidepressants among different
prescriber groups. Additional studies are needed to determine predictors of
patient response to newer antidepressants and clinical guidelines for their use.
PMID- 10669180
TI - Adverse effects of reduced-dose d-penicillamine in children with mild-to-moderate
lead poisoning.
AB - BACKGROUND: Oral chelation therapy with d-penicillamine (d-PCN) has been proven
to be effective in the treatment of mild-to-moderate lead poisoning. However, d
PCN is associated with a relatively high incidence of adverse effects when given
in the standard dose of 25-30 mg/kg/d. Lower doses of d-PCN may reduce the rate
of adverse effects without a significant reduction in the drug's efficacy.
OBJECTIVE: To examine the incidence of rash, white blood cell and platelet count
depression, and abnormal urinalysis with d-PCN when given in a dose of 15 mg/kg/d
to children with blood lead concentrations <40 microg/dL. METHODS: Retrospective
analysis of a clinical treatment course of children who received d-PCN during
1996 in the Lead and Toxicology Clinic of Children's Hospital, Boston. All
children were treated under a reduced-dose d-PCN chelation protocol. RESULTS:
During the study period, 55 children (mean age 37.4 mo) received 66 courses of d
PCN. Mean blood lead concentration before chelation was 24 microg/dL (range 15
37), with a corresponding erythrocyte protoporphyrin concentration of 42
microg/dL. After 77 days of treatment with d-PCN, blood lead concentration was
reduced to mean 16 microg/dL (mean fall 35%; p = 0.005) and erythrocyte
protoporphyrin was reduced to 28 microg/dL (p = 0.009). During chelation therapy,
the white blood cell count fell below 5,000/mm3 in seven cases (9.7%); there were
no episodes of platelet counts falling below 150,000/mm3. No cases of abnormal
urinalysis were reported; three episodes of rash (4.5%) were recorded. The only
patients prematurely terminated from therapy were those who developed rash; in
all three cases, drug eruption was an isolated occurrence, which resolved within
48 hours of diphenhydramine therapy. All adverse effects were transient and
resolved during or immediately after chelation therapy. CONCLUSIONS: Reduced-dose
d-PCN appears to maintain efficacy at reducing blood lead concentrations. Reduced
dose d-PCN also appears to be associated with a rate of adverse effects lower
than previously reported; observed adverse effects appear to be benign and
transient.
PMID- 10669181
TI - Treatment of uncomplicated urinary tract infections: exploring differences in
adherence to guidelines between three European countries. Drug Education Project
Group.
AB - OBJECTIVE: To evaluate adherence of general practitioners to treatment guidelines
regarding urinary tract infections in three European countries and to investigate
whether differences in adherence at the prescribing level within and between
countries could be explained by general practitioners' knowledge and attitudes,
characteristics, or national setting. DESIGN: Prescribing data collected in 1994
1995 were analyzed regarding use of first-choice drugs and duration of treatment,
knowledge and attitudes were assessed with a questionnaire, and multiple
regression analysis was used to explain differences in prescribing behavior
within and between countries. RESULTS: Our study is based on data from 85.6% of
the 584 general practitioners who were scheduled to participate in a continuing
education program. The mean proportion of responses in agreement with the
guidelines regarding first-choice drugs was 0.69 in Sweden, 0.78 in the
Netherlands, and 0.79 in Norway; regarding duration of treatment, the mean
proportion was 0.56 in Sweden, 0.67 in the Netherlands, and 0.59 in Norway. The
proportion of first-choice drugs prescribed for women (18-75 y) was 0.55 in
Sweden, 0.83 in the Netherlands, and 1.00 in Norway (patients >16 y). The
duration of treatment was 7.6 defined daily doses per prescription in Sweden, 5.9
in the Netherlands, and 6.6 in Norway. Knowledge and attitudes explained 0-17% of
the variation in prescribing. Years in practice explained 0-11%, and the general
practitioners' gender had no explanatory value. The national setting explained
most of the variation between countries. CONCLUSIONS: Differences in prescribing
behavior can be explained only to a small extent by deviations from the
guidelines in terms of knowledge and attitudes. Between countries, differences in
regulation, marketing, and distribution of drugs seem to be of much greater
importance.
PMID- 10669182
TI - Renal allograft dysfunction associated with rifampin-tacrolimus interaction.
AB - OBJECTIVE: To report an interaction between tacrolimus and rifampin with
subsequent adverse effects on renal allograft function. CASE SUMMARY: A 61-year
old Chinese man received a cadaveric renal transplant in 1991. Progressive
deterioration of allograft function developed during the following six years
while the patient was receiving cyclosporine and prednisolone. In January 1998,
tacrolimus was substituted for cyclosporine for late biopsy-proven graft
rejection, with target trough blood concentrations between 5 and 8 ng/mL. After
conversion, serum creatinine fell to 2.0 mg/dL; the nadir was reached within one
year. At the same time, rifampin was instituted for controlling tuberculosis and
empiric fluconazole was discontinued. Twelve days later, the patient's serum
creatinine concentration rose to 2.9 mg/dL and tacrolimus concentration fell to
1.5 ng/mL, along with oliguria. These findings suggested acute rejection, which
was successfully reversed by steroid therapy. However, more than a tenfold
increase in the tacrolimus dosage was required to maintain the same
concentrations during subsequent months, accompanied by an increase in serum
creatinine (from 2.0 to 2.6 mg/dL) and decrease in urine excretion. Biopsy at
this time demonstrated acute rejection (Banff I), chronic allograft nephropathy
(Banff II), and suspected tacrolimus nephrotoxicity. After unsuccessful
methylprednisolone recycling, mycophenolate mofetil was introduced to control
rejection and facilitate reduction of the tacrolimus dosage to minimize its
nephrotoxicity. CONCLUSIONS: As a potent CYP3A4 isoenzyme inducer, rifampin
coadministration caused the abrupt decrease in tacroiimus blood concentrations,
leading to an approximate tenfold increase in its daily dose, which may be
important to subsequent allograft dysfunctions.
PMID- 10669183
TI - Toxic epidermal necrolysis associated with acetaminophen ingestion.
AB - OBJECTIVE: To report a case of toxic epidermal necrolysis (TEN) associated with
acetaminophen ingestion. SUMMARY: A seven-year-old girl developed TEN after
acetaminophen ingestion. The diagnosis was based on clinical evaluation and skin
biopsy. A later acetaminophen challenge, undertaken by an allergist who
questioned the diagnosis, resulted in a similar skin reaction. DISCUSSION: TEN is
a severe disease with a high mortality rate. TEN may be either idiopathic or
associated with several clinical conditions, such as viral infections, autoimmune
disorders, malignancy, and drug hypersensitivity. Because of the rarity of its
association with acetaminophen, the diagnosis in our patient was questioned by an
allergist who performed an oral acetaminophen rechallenge test despite the
potential risk. This caused a severe skin reaction that required
rehospitalization. CONCLUSIONS: TEN can be caused by over-the-counter medications
such as acetaminophen. Rechallenge with the causative drug carries a risk of
severe complications and should be avoided.
PMID- 10669184
TI - Fluorouracil-induced neurotoxicity.
AB - OBJECTIVE: To report a case of acute neurologic adverse effects related to
fluorouracil administration and to review the neurotoxicity of this agent. CASE
SUMMARY: A 73-year-old white man with a history of esophageal carcinoma was
treated with fluorouracil 1,500 mg iv daily for four days. After completing
treatment, he presented with sudden onset of confusion, cognitive disturbances, a
cerebellar syndrome, and repeated seizures. A magnetic resonance image of the
brain showed no structural abnormalities, and cerebrospinal fluid examination was
normal; none of the other laboratory tests provided an explanation for his
symptoms. The patient was treated with anticonvulsants, and the cognitive changes
resolved in 72 hours. The cerebellar signs, however, did not resolve completely
and persisted when the patient was examined two weeks after discharge.
DISCUSSION: Fluorouracil can cause both acute and delayed neurotoxicity. Acute
neurotoxicity manifests as encephalopathy or as cerebellar syndrome; seizures, as
seen in our patient, have rarely been reported. Acute neurotoxicity due to
fluorouracil is dose related and generally self-limiting. Various mechanisms for
such toxicity have been postulated, and treatment with thiamine has been
recommended. Delayed neurotoxicity has been reported when fluorouracil was given
in combination with levamisole; this form of subacute multifocal
leukoencephalopathy is immune mediated and responds to treatment with
corticosteroids. CONCLUSIONS: Clinicians should be aware of the adverse
neurologic effects of fluorouracil and should include them in the differential
diagnosis when patients receiving the drug present with neurologic problems.
PMID- 10669185
TI - The effect of intravenous verapamil on cerebral hemodynamics in a migraine
patient with hemiplegia.
AB - OBJECTIVE: To describe the use of intravenous verapamil in a migraine patient
with hemiplegia to reverse the symptomatology and hemodynamics of the middle
cerebral artery as determined by transcranial Doppler. CASE SUMMARY: A 31-year
old white woman was admitted with an acute exacerbation of migraine with
hemiplegia. A transcranial Doppler showed an increased flow velocity through the
middle cerebral artery consistent with a migrainous process. The patient was
treated with verapamil 5 mg iv and the hemiplegia gradually resolved. A
transcranial Doppler indicated that the flow velocity through the middle cerebral
artery was decreased after verapamil administration, indicating reversal of the
vasospasm. DISCUSSION: Transcranial Doppler has not been previously used to
determine the effect of intravenous verapamil on the migrainous process.
Intravenous verapamil reversed the altered hemodynamics of the middle cerebral
artery as determined by transcranial Doppler. This finding correlated with the
gradual resolution of hemiplegia. Whether both subjective and objective findings
in this patient can be attributed to the reversal of the cerebral artery
hemodynamics is not known. CONCLUSIONS: Intravenous verapamil appears to reverse
the vasospasm that may be associated with a migrainous process. Whether this
effect is solely responsible for clinical improvement is not known. Verapamil may
be a consideration for the treatment of intractable migraine, especially when
there is evidence of spasm of the major cerebral arteries.
PMID- 10669186
TI - Dofetilide: a class III-specific antiarrhythmic agent.
AB - OBJECTIVE: To review published reports on the pharmacology and clinical use of
dofetilide in the management of cardiac dysrhythmias. DATA SOURCES: A MEDLINE
search (January 1966-June 1999) was performed using dofetilide and UK-68,798 as
key words. English-language articles were identified, and the references of these
articles were used to further identify pertinent articles. STUDY SELECTION: All
acquired studies and reviews discussing the pharmacology, pharmacokinetics,
chemistry, and clinical efficacy of dofetilide were reviewed. DATA EXTRACTION:
Articles were selected based on quality of review of the pharmacology and
clinical use of dofetilide. Given the paucity of data on the clinical
pharmacology and use of dofetilide, most articles obtained were used, including
abstracts when full reports were not available. DATA SYNTHESIS: Dofetilide is a
relatively specific class III antiarrhythmic agent. It increases action potential
duration and effective refractory period without impacting conduction velocity.
These actions of dofetilide are explained by its ability to inhibit the rapid
component of the delayed, outward-rectifying potassium current, thus blocking the
efflux of potassium during repolarization. Introductory investigations suggest
that dofetilide may be of use in treating and preventing atrial dysrhythmias such
as atrial fibrillation, atrial flutter, and paroxysmal supraventricular
tachycardia. Dofetilide may also have a role in preventing ventricular
tachycardia from occurring. Some data also suggest that dofetilide may improve
the morbidity of heart failure patients. Currently, the most troublesome adverse
effect of dofetilide is its propensity to induce ventricular proarrhythmias,
especially torsade de pointes. CONCLUSIONS: Based on the data currently
available, dofetilide should have a role in the pharmacotherapy of cardiac
dysrhythmias, especially those of atrial origin. More data on its efficacy and
tolerability are needed, however, to fully delineate dofetilide's role amid
currently available antiarrhythmic agents.
PMID- 10669187
TI - Homocysteine as a risk factor for atherosclerosis.
AB - OBJECTIVE: To review the role of homocysteine as a risk factor in the
pathogenesis of atherosclerosis and to provide recommendations for the treatment
of hyperhomocysteinemia. DATA SOURCES: A MEDLINE search using key terms such as
homocysteine, atherosclerosis, folic acid, vitamin B6, and vitamin B12 was
conducted for the time period 1966 through January 1999. STUDY SELECTION: An
article was selected for inclusion in this review if it assessed the relationship
and proposed mechanisms of hyperhomocysteinemia on the vasculature, physiologic
changes due to hyperhomocysteinemia, and outcomes due to hyperhomocysteinemia,
such as morbidity and mortality. In addition, studies that assessed the treatment
outcomes of hyperhomocysteinemia were evaluated. DATA SYNTHESIS: Studies of
patients with cerebral vascular disease reveal elevated homocysteine
concentrations in 30-40% of patients compared with controls. Many studies
demonstrate a correlation between elevated homocysteine concentrations, risk of
myocardial infarction, and mortality. In addition, hyperhomocysteinemia and
decreased folic acid concentrations have been identified in end-stage renal
disease (ESRD) and type 2 diabetic patients, while both concentrations remained
normal in healthy controls. Studies using folic acid 650 microg/d reduced
homocysteine concentrations to within normal therapeutic range after two weeks of
treatment. Studies with vitamins B6 and B12 have demonstrated that the use of
either alone is ineffective, but when combined or administered with folic acid,
homocysteine concentrations return to normal. All therapies must be given for the
lifetime of the patient. In addition, patients must use discretion in their diet,
as common beverages, such as coffee, have a strong correlation with
hyperhomocysteinemia, while foods high in folic acid, vitamin B6 and vitamin B12
may reduce homocysteine concentrations. Additional prospective studies are needed
to determine effects of treatment of hyperhomocysteinemia and various diets on
atherosclerotic morbidity and mortality. CONCLUSIONS: Studies demonstrate a
positive correlation between hyperhomocysteinemia and atherosclerosis. The
treatment of choice for hyperhomocysteinemia is folic acid. Although the optimal
dose is not known, 650 microg/d is the minimum effective dose. To date, no
studies have assessed the effects on morbidity and mortality when treating high
homocysteine concentrations in atherosclerotic patients.
PMID- 10669188
TI - Treatment of hypertension in the perioperative patient.
AB - OBJECTIVE: To review studies and drug therapy relating to the treatment of
hypertension in perioperative patients. DATA SOURCES: Articles were selected from
a MEDLINE search (1966-August 1998), and several textbooks on hypertension and
surgery were reviewed. In addition, bibliographies of all articles and textbook
chapters were studied for articles not found in the computerized searches. STUDY
SELECTION: Clinical studies involving hypertension in the perioperative setting
were included. The initial search was limited to studies conducted in humans and
published in English. DATA EXTRACTION: Information regarding drug therapy was
reviewed and guidelines were constructed for managing surgical patients with
acute blood pressure elevations. DATA SYNTHESIS: Although nitroprusside and
nitroglycerin, with their short onset of action and duration of effect, are
indicated for hypertensive emergencies, a variety of agents are available for
hypertensive urgencies. An algorithm that can be used as a template for the
development of intrainstitutional guidelines is provided. CONCLUSIONS: Due to the
scarcity of comparative trials, decisions involving agents for the treatment of
perioperative hypertension must often be made based on combined efficacy,
toxicity, cost, and convenience considerations.
PMID- 10669189
TI - Gender differences in depression and antidepressant pharmacokinetics and adverse
events.
AB - OBJECTIVE: To review data generated by studies examining gender differences in
the prevalence of depression, as well as in antidepressant pharmacokinetics,
pharmacodynamics, and adverse events. DATA SOURCES: Published articles and
abstracts were identified through MEDLINE (January 1966-April 1999) using the
following search terms: antidepressant, response, gender, pharmacokinetic,
pharmacodynamic, female, side effect, and adverse events. All articles that
assessed gender differences in antidepressant response, pharmacokinetics, and
adverse events, as well as articles that evaluated postulated mechanisms for
these differences, were reviewed. Additional articles were identified from
bibliographies of retrieved articles. STUDY SELECTION AND DATA EXTRACTION: All
relevant abstracts, studies, and review articles were evaluated. DATA SYNTHESIS:
Gender differences in the prevalence of depression have been reported and may
result from the interaction of several factors. Women have been shown to have a
higher incidence of depression, which may be due to artifact, social, or biologic
reasons. Studies suggest that the pharmacokinetic disposition of popular
antidepressants varies between men and women, and women taking antidepressants
may exhibit a different adverse event profile. Only one study specifically
evaluated gender differences in antidepressant treatment response. CONCLUSIONS:
Further research elucidating gender differences in response to antidepressant
treatment and on depression prevalence is needed. Some studies report that the
pharmacokinetics of antidepressants may vary between men and women. Therefore,
clinicians should be aware that potential differences in antidepressant
pharmacokinetics may exist, and a dosage adjustment may be necessary for women to
ensure a favorable drug response, compliance, and decreased incidence of adverse
events.
PMID- 10669190
TI - Hydroxyurea in the treatment of HIV-1.
AB - OBJECTIVE: To describe the role of hydroxyurea in the treatment of HIV-1. DATA
SOURCES: Published clinical studies using hydroxyurea in HIV treatment were
accessed through MEDLINE (January 1994-March 1999) and conference abstracts. All
relevant studies were evaluated. DATA SYNTHESIS: Adherence, expense, and
resistance limit the pharmacotherapeutic options in the management of patients
with HIV. Hydroxyurea may be an alternative to conventional HIV treatments.
CONCLUSIONS: Several potential advantages of adding hydroxyurea to antiretroviral
treatment regimens include the drug's well-documented toxicity, convenient
dosing, good tolerability and low cost, and its unique mechanism of action.
Hydroxyurea may have synergistic effects that prove promising in initial and
salvage therapy antiretroviral regimens. Larger, well-controlled clinical studies
are needed to adequately define the role of hydroxyurea in the treatment of HIV.
PMID- 10669191
TI - Amiloride for the prevention of amphotericin B-induced hypokalemia and
hypomagnesemia.
AB - OBJECTIVE: To review the published clinical data assessing the role of amiloride
in the prevention of amphotericin B (AmB)induced electrolyte disorders. DATA
SOURCES: A MEDLINE search (January 1966-April 1999) of English-language
literature pertaining to AmB, amiloride, potassium, and magnesium was performed.
Tertiary sources were also used. DATA EXTRACTION: In vivo and in vitro human and
animal data and case reports were included due to the lack of published clinical
trials. DATA SYNTHESIS: AmB administration can result in severe hypokalemia and
hypomagnesemia requiring chronic supplementation. In one prospective, controlled
study of hypokalemia with AmB administration, patients receiving concomitant
amiloride had significantly greater potassium concentrations (p < 0.01) and
required significantly less potassium supplementation (p < 0.001). Amiloride may
also reduce the amount of magnesium supplementation required by sparing
elimination through the kidneys. CONCLUSIONS: Amiloride may be considered for the
prevention of AmB-induced hypokalemia and hypomagnesemia, especially in patients
at high risk for complications resulting from these electrolyte disorders.
Further studies are needed to assess concomitant use of other potassium-sparing
diuretics and AmB.
PMID- 10669192
TI - Sorbitol compared with xylitol in prevention of dental caries.
AB - OBJECTIVE: To summarize published data on the comparative efficacy of sorbitol
and xylitol for prevention of dental caries. DATA SOURCES: Published double-blind
comparative trials, using sorbitol and xylitol products, identified by MEDLINE
(January 1966-December 1998) and International Pharmaceutical Abstracts (January
1970-December 1998) searches. DATA SYNTHESIS: Clinical trials generally used
sorbitol and xylitol gums, which patients chewed three to five times daily for 20
40 months. Xylitol was superior to sorbitol in two longer, secondary dentition
trials (30-63% reductions), but not in two primary dentition trials. CONCLUSIONS:
The data suggest that xylitol-containing gums may provide superior efficacy in
reducing caries rates in high-risk populations.
PMID- 10669193
TI - Medicine information help lines: a survey of hospital pharmacy-based services in
the UK and their conformity with guidelines.
AB - OBJECTIVE: To describe the prevalence and nature of hospital pharmacy-based
medicine help lines for consumers in the UK and to compare service provision with
published guidelines. BACKGROUND: Since 1992, telephone help lines for patients
have proliferated in hospital pharmacies in the UK. There is no common template
for such services with variations in target group, number and type of calls, and
arrangements for training and audit. Data on these factors will help guide
further development of such services. METHODS: All medicine help lines operating
from hospital pharmacies in the UK were identified through the national Drug
Information Pharmacists network. They were sent a piloted questionnaire covering
many aspects of help line operation, including funding, method of advertisement,
procedures, target group, number and nature of calls, and audit procedures.
RESULTS: Eighty-two help lines were identified in England, Scotland, Wales, and
Northern Ireland. Completed responses were received from 69 help lines (84%
response rate). The pharmacy drug information center was the help line site in
57% of hospitals; all other help lines were located in the dispensary. In 55% of
cases, help lines were open only to patients of the hospital. In the remainder of
help lines, calls from the public were answered (although the majority of help
lines only advertised to hospital patients). Calls were answered by pharmacists
only in 45% of services, and additional staff training had been provided in 43%.
Only 48% of services had written procedures or guidelines for operation of the
help line. Forty-six percent of the services received fewer than five calls per
week, 31% received between five and 10 calls per week, and 22% received 11 or
more calls per week. In 59% of the sites, calls took an average of 10 minutes or
less to answer; it took 11-15 minutes in 32% of the sites and >15 minutes in 9%
of the sites. The most common queries related to adverse effects, dosage and
administration, and interactions (including alcohol). Only 33% of help lines had
any auditing or monitoring of the service in place. CONCLUSIONS: The increasing
use of the telephone to provide services directly to consumers is reflected in
the growth of hospital-based medicine help lines in the UK. The telephone route
is likely to become more important as patients' needs for information about their
medicines increase. However, the rate of calls is low when compared with the
number of patients issued prescriptions; further research is needed to
investigate the reasons for this low response. There is currently reason for
concern because most help lines lack not only professional training in telephone
counseling, but also proper documentation, monitoring, and audit procedures.
PMID- 10669194
TI - The role of the pharmacist in humanitarian aid in Bosnia-Herzegovina: the
experience of Pharmaciens Sans Frontieres.
AB - BACKGROUND: Founded in 1985, Pharmaciens Sans Frontieres (PSF) is a
nongovemmental organization of pharmacists involved in humanitarian aid. PSF
relied on approximately 100 expatriates in 1998, which included 50 pharmacists
distributed throughout 24 missions (i.e., 14 emergency, 7 development, 3
assessment). It is necessary to add 200-250 local staff to this group. OBJECTIVE:
To describe PSF's mission in Bosnia-Herzegovina from 1992 to 1999 and to define
the pharmacist's impact in the supply of medicines and the development of
pharmaceutical care and services. RESULTS: In April 1992, at the beginning of
Sarajevo's siege, PSF sent a small team of three volunteer pharmacists to Bosnia
Herzegovina. The objective of the emergency phase (1992-1995) was to set up a
massive supply program of essential medicines and medical and biologic materials
and to implement a distribution system based on existing health centers. The
signing of the Dayton peace agreement and a progressive return to peace and
stability marked the beginning of the postemergency phase (1995-1997). This phase
pursued previous objectives of establishing a distribution network and added the
implementation of logistic centers. PSF widened its involvement to medical
laboratory analysis, production of medicines, disposal of expired medications
sent during the conflict, and the implementation of a national center for quality
control. Currently, the development phase's (1998-1999) objective is to provide
adequate support for the reorganization of pharmaceutical care and services by
establishing pharmacy work groups and developing and maintaining good
relationships with the international community and Bosnia-Herzegovina
pharmacists. CONCLUSIONS: Humanitarian aid is essential in major conflicts, as
seen in the case of Bosnia-Herzegovina. Although it is difficult to evaluate the
impact of the distribution network implemented by PSF, it allowed for a better
provisioning of medications to the general population. PSF played an important
role in such cases. In fact, PSF provides its pharmaceutical expertise to these
embattled areas not only by offering financial support to the logistics or
supplying of medications, but by offering professional support to the
organization/reorganization of the pharmaceutical practice.
PMID- 10669195
TI - Glimepiride-induced thrombocytopenic purpura.
PMID- 10669196
TI - Effect of azathioprine on the anticoagulant activity of warfarin.
PMID- 10669197
TI - Carbamazepine and/or fluvoxamine drug interaction with risperidone in a patient
on multiple psychotropic medications.
PMID- 10669198
TI - PKBase: a population approach-oriented database.
PMID- 10669199
TI - ADEM: literature review and case report of acute psychosis presentation.
AB - Acute disseminated encephalomyelitis is a monophasic, immune-mediated disorder
that produces multifocal demyelinating lesions within the central nervous system.
It is characterized clinically by the acute onset of neurologic abnormalities,
including varying degrees of mental state changes ranging from drowsiness to
coma. It is unusual for the illness to present as an isolated acute psychosis.
The case of a 14-year-old female with biopsy-confirmed acute disseminated
encephalomyelitis, who was initially diagnosed with an acute psychiatric
disorder, is presented, and published reports on this unusual manifestation are
reviewed. A Medline database search was performed from 1965 to 1999, using the
terms acute disseminated encephalomyelitis, postvaccinal encephalomyelitis,
postinfectious encephalomyelitis, and measles encephalomyelitis, combined with
the terms psychosis, psychiatric disorder, and behavioral disorder. Selected
cross-referenced reports were also reviewed. Nine patients were identified who
presented with acute psychosis. We conclude that, although rare, acute
disseminated encephalomyelitis can present as an acute psychosis. This immune
mediated condition should be included in the differential diagnosis of neurologic
disorders presenting as a psychiatric illness.
PMID- 10669200
TI - Intranasal midazolam as a treatment of autonomic crisis in patients with familial
dysautonomia.
AB - To evaluate the efficacy and safety of intranasal midazolam in the treatment of
autonomic crises in children with familial dysautonomia, intranasal midazolam was
administered at the hospital to six patients during nine episodes of autonomic
crisis. Treatment was successful in seven of nine episodes of autonomic crisis in
five of six patients, with a mean interval to response of 9.25 +/- 1.25 minutes.
The parents of five patients in whom the treatment was successful were instructed
to use midazolam at home. At home, 16 additional episodes were treated by the
parents, with successful control achieved in 14 (87%). The mean interval to
response was 12.8 +/- 2 minutes. No significant side effects were observed at the
hospital or at home after intranasal administration of midazolam. Midazolam,
given intranasally, is effective and safe in the management of autonomic crises
in patients with familial dysautonomia, either in the hospital or at home by the
parents after appropriate instruction.
PMID- 10669201
TI - Generalized spike-and-wave patterns in children: clinical correlates.
AB - All electroencephalograms performed in our institution between 1980 and 1990 were
reviewed. The clinical characteristics of children with epilepsy and generalized
spike-and-wave (SW) patterns were analyzed. The SW patterns were classified
according to their frequency. Electroencephalograms of 154 children with epilepsy
revealed SW patterns. Absence seizures were the most common first seizure, but
partial seizures were frequent. More than 40% had several types of seizures.
Sixty percent of the epileptic syndromes were generalized, but almost 25% were
partial. The typical SW pattern was associated with absence seizures, a normal
examination and computed tomographic scan, idiopathic generalized epilepsies,
monotherapy, freedom from seizures, and lack of recurrence. The slow SW pattern
was associated with West syndrome; a younger age at seizure onset; atonic,
myoclonic, tonic, and partial simple seizures; an abnormal examination and
computed tomographic scan; cryptogenic or symptomatic generalized epilepsy or
symptomatic partial epilepsy; polytherapy; and poor seizure control. The fast SW
pattern was associated with secondary generalized, partial, tonic-clonic, and
complex partial seizures; a normal computed tomographic scan; cryptogenic partial
epilepsy; isolated seizures; and seizure recurrence. Epilepsy with a typical SW
pattern should be considered benign, epilepsy with a slow SW pattern malignant,
and epilepsy with a fast SW pattern treacherous.
PMID- 10669202
TI - Clinical and molecular studies in three Portuguese mtDNA T8993G families.
AB - The T8993G mutation in the mitochondrial DNA adenosine triphosphatase 6 gene
represents an important cause of maternally inherited Leigh's syndrome. Reported
are the clinical findings and mutational loads in three Portuguese T8993G
pedigrees. Polymerase chain reaction-restriction fragment length polymorphism
analyses demonstrated the T8993G mutation in a high percentage of tissues from
all patients (97% +/- 2.3%), but it was less abundant in the blood from 14
maternal relatives. The disease progressed severely in the probands but did not
have the fatal course reported by others. To test whether this prolonged course
was related to the presence of a specific, disease-associated haplogroup the
origin of the mutational event in Portugal was traced. Haplotype investigation
revealed an independent occurrence of the mutation in the three probands. These
analyses represent the first molecular characterization of Portuguese patients
with Leigh's syndrome.
PMID- 10669203
TI - Sleep apnea treatment improves seizure control in children with
neurodevelopmental disorders.
AB - Seizure disorder and sleep apnea are common chronic disorders in children, but
the relationship between sleep apnea and seizure control has not been studied in
the pediatric population. This retrospective review included nine children with
neurodevelopmental disorders who had well-documented sleep apneic episodes and
seizure disorders. Seizure frequency was reduced in five patients (56%) in the
first 12 months after sleep apnea treatment without changes in their
antiepileptic medications. Sleep apnea can be one of the seizure precipitants in
children with epilepsy. This study indicates the importance of identifying sleep
apnea when treating children with intractable epilepsy, particularly in those who
are at high risk.
PMID- 10669204
TI - High-dose intravenous immunoglobulin therapy in juvenile myasthenia gravis.
AB - Autoimmune neurologic disease management has been significantly modified by the
use of high-dose intravenous immunoglobulin (HDIVIG) during the past 15 years.
Venous access, readily available IgG (until recently), and the relative lack of
serious identifiable complications have prompted its use in myasthenia gravis. In
adults, its effectiveness has been inconsistent, with variable acetylcholine
receptor (AChR) antibody responses. Ten children were evaluated for clinical
responses to, and complications of, HDIVIG. Weekly anti-AChR antibody titers in
three patients were obtained. The HDIVIG dosage was 2 gm/kg body weight, infused
at variable rates of 2 gm/kg for 1 day, 0.66 gm/kg daily for 3 days, and 0.5 g/kg
daily for 4 days; in one patient the total dose was 0.8 gm/kg to correct to the
ideal body weight. All children but one tolerated HDIVIG without complications.
Eight patients exhibited definite improvement in functional strength after
HDIVIG, but a decreasing response to HDIVIG was evident after multiple monthly
treatments, warranting the additional use of corticosteroids in two patients. A
decrease in anti-AChR antibody levels was observed in the three patients tested,
but this decrease was constant in one patient. No correlation was observed
between clinical response and antibody titers. HDIVIG is safe and effective in
most patients for short-term management of juvenile myasthenia gravis, in
myasthenic crises, and in preparing patients for surgery but appears to be of
limited long-term benefit.
PMID- 10669205
TI - Clinical and cerebral FDG PET scan in a patient with Krabbe's disease.
AB - A 2-year, 6-month-old Saudi male with infantile Krabbe's disease was studied with
fluorine-18-labeled-2-fluoro-2-deoxyglucose positron emission tomography (FDG
PET) scan. The patient presented with a gradual loss of developmental milestones,
irritability, and crying. At the advanced stage of the disease, he developed
tonic-clonic seizures and became a microcephalic, extremely irritable, blind,
spastic quadriplegic child, with no deep tendon reflexes. Laboratory studies
revealed normal blood chemistry, muscle enzymes, very long chain fatty acids, and
acylcarnitines. No abnormal urinary organic acids were detected. The
cerebrospinal fluid protein concentration was increased. Magnetic resonance
imaging of the brain revealed mild brain atrophy and white matter disease mainly
in the centrum semiovale. Electroretinography was normal; however,
electroencephalography and visual-evoked potentials were abnormal. Peripheral
nerve conduction studies documented a demyelinating neuropathic process. The FDG
PET study of the brain demonstrated a marked decrease in the metabolism of the
left cerebral cortex and no uptake in the caudate heads. Normal glucose uptake
was observed in the thalami, lentiform nuclei, and cerebellum. The patient did
not present for subsequent clinic visits and is presumed dead.
PMID- 10669206
TI - Potential hepatotoxicity of lamotrigine.
AB - Lamotrigine is a new antiepileptic drug that is effective for a broad range of
seizures in adults and children. Three children with seizures of different causes
who were treated with lamotrigine and developed reversible hepatotoxicity are
reported. In one child, this therapy led to relatively severe hepatic failure
that required and responded to aggressive therapy. Unlike most of the previously
reported six patients with similar severe hepatic involvement, this patient's
liver function and blood hepatic enzymes became normal. All three patients were
on multiple drugs, and two were in epilepsia partialis continua secondary to
encephalitis. Two of the patients had relatively rapid medication titration
schedules. The close time relationship between the initiation of the lamotrigine
therapy and the reversal of the liver abnormalities with lamotrigine
discontinuation argues against a cause other than the lamotrigine; however,
because of the complexity of the reported cases, the causality remains an
assumption. Review of the literature revealed six other previously reported
patients (five adults and one child) who had hepatotoxicity during lamotrigine
therapy, with or without associated multisystem failure, and similar patient
profiles. Lamotrigine is generally a safe and effective medication; however, it
should be used with caution in patients on polytherapy and in those with
complicated acute systemic and central nervous system conditions, such as fever,
status epilepticus, epilepsia partialis, and encephalitis.
PMID- 10669207
TI - Mitochondrial complex I deficiency in a female with multiplex arthrogryposis
congenita.
AB - A 10-year-old female with arthrogryposis multiplex congenita is presented.
Clinical, neurophysiologic, and histologic findings suggested a mild myopathy.
The analysis of enzymatic activity in the homogenate and of mitochondrial
function in saponin-permeabilized fibers from the muscle biopsy revealed an
approximately twofold-decreased specific activity of the NADH:CoQ oxidoreductase
(complex I of the mitochondrial respiratory chain) that was compensated for by an
increased number of mitochondria. The complex I deficiency was also detected in
cultivated skin fibroblasts of the patient. The observed defect of mitochondrial
oxidative phosphorylation in arthrogryposis multiplex congenita may be of
pathogenetic relevance.
PMID- 10669208
TI - Neuroblastoma associated with seizures and arrested development.
AB - Two unrelated cases of childhood peripheral neuroblastoma associated with
infantile seizures and developmental problems (but without opsoclonus-myoclonus)
are presented. The considerable body of evidence supporting the view that the
opsoclonus-myoclonus syndrome associated with neuroblastoma has an immunologic
basis is reviewed. Patients with neuroblastoma and opsoclonus-myoclonus syndrome
commonly have subsequent developmental problems and, rarely, may have seizures.
The authors postulate that the seizures and developmental problems in their two
patients may result from an immunologic mechanism similar to that suggested for
the opsoclonus-myoclonus syndrome of neuroblastoma. The only laboratory evidence
to support an immunologic mechanism in these two patients was the presence of
raised cerebrospinal fluid immunoglobulins in Patient 2. Specific antineuronal
antibody tests in Patient 2 were negative. It is therefore possible that the
association reported in these two unrelated cases is coincidental. However,
reasonably extensive investigations did not uncover an alternative etiology for
the presence of the seizures and developmental delay.
PMID- 10669209
TI - Aggressive behavior in patients with Sotos syndrome.
AB - Sotos syndrome is characterized by peculiar facies, prenatal and postnatal
overgrowth, and developmental delay. The course of six patients with psychiatric,
neurologic, and magnetic resonance imaging evaluations is reported. Three (50%)
of the six patients were observed to have a tendency toward aggressiveness,
including one who had pyromania.
PMID- 10669210
TI - Gabapentin treatment in a child with delayed-onset hemichorea/hemiballismus.
AB - A 13-year, 6-month-old female was evaluated for subacute onset of left-sided
hemichorea/hemiballismus, with an old, right parietal, cortical, and subcortical
stroke as the presumed cause. Treatment with gabapentin was initiated, with good
results at 6-month follow-up. Discussion of the differential diagnosis and
evaluation of delayed-onset movement disorders in children and the mechanism of
action of gabapentin is included.
PMID- 10669211
TI - Congenital intracranial teratoma.
AB - Congenital intracranial teratoma is a rare disease. A fetus with a congenital
intracranial teratoma presenting with a disproportionately enlarged head at 27
weeks gestation is presented. Prenatal ultrasonography and fetal magnetic
resonance imaging demonstrate a huge, heterogenous intracranial mass in the left
supratentorial region, with the left cerebral hemisphere being compressed and
flattened. The infant died of respiratory failure within 24 hours of birth at 28
weeks gestation. On postmortem examination the histologic report revealed an
immature teratoma. Fetal MRI is helpful in the prenatal diagnosis and evaluation
of intracranial tumor.
PMID- 10669212
TI - Plantar grasp reflex in high-risk infants during the first year of life.
AB - For most primitive reflexes, retention of the reflex beyond the period when it
should no longer be elicited suggests a pathologic process within the central
nervous system. However, for certain primitive reflexes, such as the plantar
grasp reflex, a negative response within the first months of life is suggestive
of a neurologic abnormality. From the results of one prospective and one
retrospective study, it is clearly indicated that the absence of the plantar
grasp reflex from 3 months of age and on correlates with the development of
spastic cerebral palsy. The specific combination of presence or absence of
specific primitive reflexes, postural reactions, or both may accurately predict a
specific type of cerebral palsy or neurodevelopmental abnormality.
PMID- 10669213
TI - Spine imaging.
PMID- 10669215
TI - Interventional neuroradiology.
PMID- 10669214
TI - Brain imaging.
PMID- 10669216
TI - Head and neck imaging.
PMID- 10669217
TI - Pediatric neuroradiology.
PMID- 10669218
TI - The future of neurologic MR imaging.
PMID- 10669219
TI - Implications of a reliable method for quantifying brain injury associated with
repair of carotid artery stenosis.
PMID- 10669220
TI - Staining for apoptosis: now neuropathologists can "see" leukoaraiosis.
PMID- 10669221
TI - The residents did not miss many? Are you kidding?
PMID- 10669222
TI - Guidelines for diagnostic neuroangiography: a model to emulate from a
neuroradiologist's perspective.
PMID- 10669223
TI - Toward an understanding of syringomyelia: MR imaging of CSF flow and neuraxis
motion.
PMID- 10669224
TI - Ischemia after carotid endarterectomy: comparison between transcranial Doppler
sonography and diffusion-weighted MR imaging.
AB - BACKGROUND AND PURPOSE: Hyperintense signals on diffusion-weighted MR images
(DWIs) are believed to correspond accurately with cerebral ischemic events.
Intraoperative transcranial Doppler sonography (TCD) can reveal hemodynamic and
embolic events during carotid endarterectomy (CEA). Our purpose was to determine
whether the occurrence of hyperintense signals on postoperative DWIs corresponds
to intraoperative embolic or hemodynamic events. METHODS: Seventy-seven CEAs were
monitored intraoperatively with TCD to record blood flow velocity changes after
cross clamping to ascertain the presence of adequate collateral flow and to
record microembolic signals. DWI was used to classify the hemisphere ipsilateral
to the CEA by type: 0, no lesions (n = 51); I, cortical lesions only (n = 2); II,
subcortical white matter lesions only (n = 6); III, mixed type with cortical and
subcortical lesions (n = 11); IV, large territorial infarcts (n = 6); and V,
other types of lesions (n = 1). RESULTS: Neither the five clinical events (one
transient ischemic attack, two minor strokes, and two major strokes) nor any DWI
type (I-V) showed a relationship to blood velocity decreases after cross clamping
or, in patients who were selectively shunted, to total ischemic time necessary
for shunt insertion and removal. Total microembolic signal count was
significantly higher in the five CEAs with clinical events than in those without.
It was also higher on the DWIs showing a hyperintense lesion as compared with
DWIs showing no lesion. CONCLUSION: Apart from lesions corresponding to clinical
deficits, CEA is associated with a substantial number of small areas of brain
tissue at risk for irreversible ischemia. The main cause of intraoperative stroke
seems to be embolism, suggesting that microembolic signals in CEA are highly
relevant events for brain tissue.
PMID- 10669225
TI - Incidence of postangiographic abnormalities revealed by diffusion-weighted MR
imaging.
AB - BACKGROUND AND PURPOSE: Occasionally we have observed anecdotal cases of
asymptomatic hyperintensities on diffusion-weighted MR (DW-MR) examinations of
the brain of patients who previously underwent routine cerebral angiography.
These observations, as well as MR imaging and transcranial Doppler data in the
literature suggesting a high rate of procedure-associated emboli, raise concern
regarding the underdiagnosis of asymptomatic focal infarction associated with
cerebral angiography. In order to determine whether asymptomatic diffusion
abnormalities are frequently associated with procedures, we prospectively
obtained DW-MR images before and after routine cerebral angiography. METHODS:
Twenty consecutive patients, who met protocol criteria and received a routine
three- or four-vessel diagnostic cerebral angiogram at our institution, were
evaluated. Using a Bayesian estimate to establish an upper bound for the
incidence of an event with zero occurrences in a study sample, the study group
size was selected to exclude a 10% incidence of abnormalities revealed by DW-MR
imaging of patients who underwent previous cerebral angiography. Two
neuroradiologists evaluated imaging studies. RESULTS: Neither clinical signs nor
abnormalities on DW-MR images were found, which suggested no infarction after
angiography in our patient sample. Based on this data, an upper bound of 9% (95%
confidence) is predicted for the appearance of abnormalities revealed by DW-MR
imaging after cerebral angiography. CONCLUSION: Cerebral angiography is
associated with an incidence of asymptomatic cerebral infarction of no more than
9%. It well may be substantially lower than this estimate; a more accurate
evaluation of the true incidence would require a significantly larger study
population. This test provides a convenient noninvasive means of assessing
procedure-related cerebral infarction, such as that which occurs after carotid
endarterectomy or vascular angioplasty and stenting.
PMID- 10669226
TI - Histopathologic correlates of temporal diffusion changes in a rat model of
cerebral hypoxia/ischemia.
AB - BACKGROUND AND PURPOSE: Although diffusion-weighted MR imaging is a powerful tool
for evaluating brain ischemia, histopathologic correlates of temporal diffusion
changes in cerebral hypoxia/ischemia have not been extensively examined.
Diffusion-weighted MR imaging was used to evaluate the relationship between the
time course of apparent diffusion coefficient (ADC) changes and the
histopathologic findings in cerebral hypoxia/ischemia. METHODS: Thirty 3-week-old
rats were subjected to either a 15-, 30-, or 60-minute hypoxic/ischemic insult
(unilateral common carotid artery ligation and exposure to 8% oxygen), during and
after which diffusion- and T2-weighted MR imaging was performed. Each animal was
killed 48 hours or 6 hours after the insult, and fixed sections of the parietal
cortex were examined by light microscopy. Ten other (control) rats were subjected
to only unilateral common carotid artery ligation or hypoxia. RESULTS: The
experimental rats showed three patterns of ADC change, depending on the duration
of the hypoxic/ischemic insult: transient (15-minute), biphasic (15-, 30-, or 60
minute), and persistent (60-minute) ADC reduction patterns. The transient ADC
reduction pattern (reduction during the insult and recovery after resuscitation)
was associated with selective neuronal death. The biphasic and persistent ADC
reduction patterns (transient recovery and no recovery after resuscitation,
respectively) were associated with cerebral infarction. CONCLUSION: Different
temporal patterns of ADC change are associated with different histopathologic
findings. Although the clinical manifestations of these different histopathologic
presentations are not yet defined, this study indicates that sequential diffusion
studies are a potentially powerful tool in the evaluation of hypoxic/ischemic
brain injury.
PMID- 10669227
TI - Diffusion- and perfusion-weighted MR imaging of dural sinus thrombosis.
AB - A patient with dural sinus thrombosis had progressively worsening symptoms and
signs that resolved after intradural thrombolysis. Intradural sinus pressures
were 54 mm Hg. Echo-planar MR imaging revealed complex abnormalities of diffusion
and widespread delay in mean transit time that improved immediately after
thrombolysis. This case suggests that diffusion- and perfusion-weighted imaging
can provide valuable information noninvasively to help triage patients with dural
sinus thrombosis between conservative and aggressive management.
PMID- 10669228
TI - Cerebral MR venography: normal anatomy and potential diagnostic pitfalls.
AB - BACKGROUND AND PURPOSE: MR venography is often used to examine the intracranial
venous system, particularly in the evaluation of dural sinus thrombosis. The
purpose of this study was to evaluate the use of MR venography in the depiction
of the normal intracranial venous anatomy and its variants, to assess its
potential pitfalls in the diagnosis of dural venous sinus thrombosis, and to
compare the findings with those of conventional catheter angiography. METHODS:
Cerebral MR venograms obtained in 100 persons with normal MR imaging studies were
reviewed to determine the presence or absence of the dural sinuses and major
intracranial veins. RESULTS: Systematic review of the 100 cases revealed
transverse sinus flow gaps in 31% of the cases, with 90% of these occurring in
the nondominant transverse sinus and 10% in the codominant transverse sinuses. No
flow gaps occurred in the dominant transverse sinuses. The superior sagittal and
straight sinuses were seen in every venogram; the occipital sinus was seen in
only 10%. The vein of Galen and internal cerebral veins were also seen in every
case; the basal veins of Rosenthal were present in 91%. CONCLUSIONS: Transverse
sinus flow gaps can be observed in as many as 31% of patients with normal MR
imaging findings; these gaps should not be mistaken for dural sinus thrombosis.
PMID- 10669229
TI - Apoptosis in leukoaraiosis.
AB - We report a case of leukoaraiosis that was studied for apoptosis. In the
neuropil, the number of cells that showed DNA fragmentation was 2.5 times as
great in the area of leukoaraiosis as in the adjacent white matter (P = .004) and
25 times as great as in the nearby cortex (P < .001). Our findings suggest that
apoptosis, predominantly of oligodendrocytes, is involved in the pathogenesis of
leukoaraiosis. Within the area of leukoaraiosis, we also found numerous small
veins that were partially occluded by severe collagenous thickening of the vessel
walls. This collagenosis may have contributed to or resulted from chronic
ischemia in that area.
PMID- 10669230
TI - Proton MR spectroscopy and preoperative diagnostic accuracy: an evaluation of
intracranial mass lesions characterized by stereotactic biopsy findings.
AB - BACKGROUND AND PURPOSE: MR imaging has made it easier to distinguish among the
different types of intracranial mass lesions. Nevertheless, it is sometimes
impossible to base a diagnosis solely on clinical and neuroradiologic findings,
and, in these cases, biopsy must be performed. The purpose of this study was to
evaluate the hypothesis that proton MR spectroscopy is able to improve
preoperative diagnostic accuracy in cases of intracranial tumors and may
therefore obviate stereotactic biopsy. METHODS: Twenty-six patients with
intracranial tumors underwent MR imaging, proton MR spectroscopy, and
stereotactic biopsy. MR spectroscopic findings were evaluated for the
distribution pattern of pathologic spectra (NAA/Cho ratio < 1) across the lesion
and neighboring tissue, for signal ratios in different tumor types, and for their
potential to improve preoperative diagnostic accuracy. RESULTS: Gliomas and
lymphomas showed pathologic spectra outside the area of contrast enhancement
while four nonastrocytic circumscribed tumors (meningioma, pineocytoma,
metastasis, and germinoma) showed no pathologic spectra outside the region of
enhancement. No significant correlation was found between different tumor types
and signal ratios. MR spectroscopy improved diagnostic accuracy by
differentiating infiltrative from circumscribed tumors; however, diagnostic
accuracy was not improved in terms of differentiating the types of infiltrative
or circumscribed lesions. CONCLUSION: MR spectroscopy can improve diagnostic
accuracy by differentiating circumscribed brain lesions from histologically
infiltrating processes, which may be difficult or impossible solely on the basis
of clinical or neuroradiologic findings.
PMID- 10669231
TI - Single- and multiple-event paradigms for identification of motor cortex
activation.
AB - BACKGROUND AND PURPOSE: The "single-event" technique has been used as an
alternative to the "block-trial" method to detect activation that may be
accompanied by head motion. The purpose of this study was to compare the two
methods for measuring activation in the sensorimotor cortex secondary to motor
tasks. METHODS: Functional MR imaging data were acquired from six participants as
they performed tasks with their fingers, tongues, and toes in a block-trial and a
single-event paradigm. For the block trial, the participant was instructed to
perform the task when cued at a rapid self-timed rate for 15 seconds, alternating
with 15 seconds of rest. Five periods of task performance and six rest periods
were included in one acquisition. For the single-event method, the participant
performed the task a single time every 15 seconds when cued by the investigator,
for a total of 21 times. Using conventional parcellation methods, activation was
detected by a cross-correlation technique and was classified as occurring in the
sensorimotor cortex, supplementary motor area (SMA), or as nonspecific.
Differences between the two acquisition paradigms were tested using the standard
t test at a significance level of P < .05. RESULTS: Activation was identified by
both the block-trial and the single-event methods for the finger task, for the
tongue task, and inconsistently for the toe task. More motion artifact occurred
in conjunction with the toe and tongue tasks than with the finger tasks. On
average, more activated pixels were identified by the single-event method than by
the block-trial method. For these motor tasks, however, a larger percentage of
pixels detected by the block-trial method than by the single-event method were
specific for the sensorimotor cortex or SMA as sites of activation. CONCLUSION:
For the tongue and the toe movement tasks, which may produce some head motion
artifacts, the single-event paradigm provides a useful alternative to the block
trial method for identifying the sensorimotor cortex or SMA. It does not achieve
a greater percentage of activation within primary motor areas. For the finger
movement task, which does not usually produce head motion artifacts, the block
trial method generally produced a greater percentage of activated pixels in the
sensorimotor cortex or SMA than did the single-event method.
PMID- 10669232
TI - Brain fluorine-18 fluorodeoxyglucose imaging with dual-head coincidence gamma
camera: comparison with dedicated ring-detector positron emission tomography.
AB - BACKGROUND AND PURPOSE: Dual-head coincidence gamma camera (DHC) imaging has been
proposed as an alternative to dedicated ring-detector positron emission
tomography (dr-PET) for clinical fluorodeoxyglucose (FDG) studies. The purpose of
this investigation was to assess the quality of DHC images in FDG studies of the
human brain. METHODS: Seven healthy volunteers and 12 patients with various
cerebral disorders underwent consecutive brain dr-PET and DHC with FDG. All sets
of images were compared semiquantitatively using regions of interest. RESULTS:
Cortical count ratios to the cerebellum on DHC and dr-PET images did not differ
significantly among the volunteers, except in the superior frontal cortex and
thalamus. In all studies including those of cerebral disorders, the mean cortical
to-cerebellar ratios of DHC and dr-PET images correlated closely. CONCLUSION: FDG
imaging with DHC delineated the metabolic distribution of glucose in the brain as
well as dr-PET did, except in the superior frontal cortex and thalamus.
Therefore, DHC may be a dedicated cost-effective means of detecting metabolic
abnormalities in the brain.
PMID- 10669233
TI - Visualization of intravenously administered contrast material in the CSF on fluid
attenuated inversion-recovery MR images: an in vitro and animal-model
investigation.
AB - BACKGROUND AND PURPOSE: The FLAIR (fluid-attenuated inversion-recovery) pulse
sequence has been shown to be sensitive to abnormalities of the subarachnoid
space. Our clinical experience led us to investigate whether intravenously
injected contrast material can affect the appearance of the subarachnoid space on
FLAIR MR images. METHODS: After noting unexplained high signal in the
subarachnoid space on FLAIR images in a patient, we studied two dogs with
sequential FLAIR MR imaging after i.v. administration of contrast material. A
third dog was studied with a 6-hour delayed FLAIR sequence after triple-dose (0.3
mmol/kg) i.v. contrast administration. CSF was obtained from two animals for
measurement of gadolinium concentration. A phantom was developed to determine the
lowest concentration at which the effects of gadolinium were evident on FLAIR
images in vitro. RESULTS: In all three animals, the appearance of the CSF in the
ventricles or subarachnoid space was modified after administration of i.v.
contrast. This was most evident on delayed images. The CSF samples showed a
gadolinium concentration of 0.007 mmol/L in the dog who received the 0.1 mmol/kg
dose and 0.02 mmol/L in the dog who received a triple dose. In our in vitro
phantom experiments, gadolinium effects were evident on FLAIR images at a
concentration four times lower than those on T1-weighted images. CONCLUSION: I.v.
contrast material can cross into the CSF in sufficient concentration to alter the
appearance of the subarachnoid space on FLAIR images in normal dogs. Although we
encountered two patients with CNS disease in whom enhancement of the CSF was seen
on postcontrast FLAIR images, additional investigation is needed in humans to
determine whether enhancement may occur at triple dose in healthy subjects.
PMID- 10669234
TI - Gender effects on age-related changes in brain structure.
AB - BACKGROUND AND PURPOSE: Previous reports have suggested that brain atrophy is
associated with aging and that there are gender differences in brain atrophy with
aging. These reports, however, neither exclude silent brain lesions in "healthy
subjects" nor divide the brain into subregions. The aim of this study is to
clarify the effect of gender on age-related changes in brain subregions by MR
imaging. METHODS: A computer-assisted system was used to calculate the brain
matter area index (BMAI) of various regions of the brain from MR imaging of 331
subjects without brain lesions. RESULTS: There was significantly more brain
atrophy with aging in the posterior parts of the right frontal lobe in male
subjects than there was in female subjects. Age-related atrophy in the middle
part of the right temporal lobe, the left basal ganglia, the parietal lobe, and
the cerebellum also was found in male subjects, but not in female subjects. In
the temporal lobe, thalamus, parieto-occipital lobe, and cerebellum, brain volume
in the left hemisphere is significantly smaller than in the right hemisphere; sex
and age did not affect the hemisphere differences of brain volume in these
regions. CONCLUSION: The effect of gender on brain atrophy with aging varied in
different subregions of the brain. There was more brain atrophy with aging in
male subjects than in female subjects.
PMID- 10669235
TI - Serial CT and MR imaging of carmustine wafers.
AB - BACKGROUND AND PURPOSE: A new option in the treatment of recurrent malignant
glioma is surgical placement of chemotherapy-laden biodegradable wafers. We
describe the CT and MR appearance of chemotherapy wafers in patients after
surgery for recurrent malignant glioma METHODS: Eighteen patients had carmustine
(BCNU) wafers implanted during reoperation for malignant glioma; three patients
had empty, placebo wafers placed. The 21 patients had a total of 22 CT and 57 MR
imaging studies. Repeat CT studies were conducted for up to 6 months, the MR
studies for up to 1 year. Examinations were evaluated for attenuation on CT
scans, signal abnormalities on MR images, and changing appearance during the
follow-up period. Enhancement characteristics were also assessed. RESULTS: On CT
scans, 13 of 16 acute (<7 days) cases showed linear high-attenuation wafers, with
three showing low attenuation. On MR images, all T1 and T2 studies performed in
the acute stage showed decreased signal of the wafers. Eight of 15 studies showed
a transient increase in T1 only at about 2 months. Wafers decreased in
conspicuity on both CT and MR studies after 2 months. The wafers did not enhance.
One postoperative tumor showed a transient increase in edema and increased
enhancement at 5 weeks. The presence or absence of BCNU within the wafers did not
change their appearance. CONCLUSION: BCNU wafers have a characteristic
appearance: in the first 7 days after implantation they are linear, usually of
increased attenuation on CT scans, and always show decreased signal on MR images;
they do not enhance, and become less conspicuous after 2 months.
PMID- 10669236
TI - Clinical consequences of misinterpretations of neuroradiologic CT scans by on
call radiology residents.
AB - BACKGROUND AND PURPOSE: Studies have looked at the accuracy of radiologic
interpretations by radiology residents as compared with staff radiologists with
regard to emergency room plain films, emergency room body CT scans, and trauma
head CT scans; however, to our knowledge, no study has evaluated on-call resident
interpretations of all types of neuroradiologic CT scans. Both as a part of our
departmental quality control program and to address concerns of clinical services
about misinterpretation of neuroradiologic CT scans by on-call radiology
residents, we evaluated the frequency of incorrect preliminary interpretations of
neuroradiologic CT scans by on-call radiology residents and the effect of such
misinterpretations on clinical management and patient outcome. METHODS: As
determined by the staff neuroradiologist the next day, all potentially clinically
significant changes to preliminary reports of emergency neuroradiologic CT scans
rendered by on-call radiology residents were recorded over a 9-month period. A
panel of neuroradiologists reviewed and graded all the changed cases by
consensus. An emergency department staff physician reviewed medical records of
all submitted cases to determine clinical consequences of the misinterpretations.
RESULTS: Significant misinterpretations were made in 21 (0.9%) of 2388 cases
during the study period. There was a significant change in patient management in
12 of the cases, with a potentially serious change in patient outcome in two
cases (0.08%). CONCLUSION: On-call radiology residents have a low rate of
significant misinterpretations of neuroradiologic CT scans, and the potential to
affect patient outcome is rare.
PMID- 10669237
TI - MR imaging features of clear-cell meningioma with diffuse leptomeningeal seeding.
AB - Clear-cell meningioma is a rare disease entity showing a more aggressive nature,
clinically, than those of other subtypes of meningioma. It occurs in younger
persons and commonly in the spinal canal. The recurrence rate has been reported
to be as high as 60%. We present a case of clear-cell meningioma in a 17-year-old
man in whom initial MR imaging showed localized leptomeningeal enhancement that
had progressed into the entire subarachnoid space after surgical resection of the
primary tumor.
PMID- 10669238
TI - Reproducibility of magnetization transfer ratio histogram-derived measures of the
brain in healthy volunteers.
AB - Using two MR scanners, we evaluated the intraobserver, interobserver, image
reimage, and interimager variabilities in the assessment of magnetization
transfer ratio (MTR) histograms obtained monthly on four occasions from five
healthy volunteers. With multiple observers, the mean coefficients of variations
ranged from 2.2% to 8.2% for "pure" image-reimage variability, from 1.2% to 4.9%
for interobserver variability, and from 2.1% to 4.9% for image-reimage
variability. The mean intraobserver coefficients of variations were always lower
than 1%. The mean coefficients of variations ranged from 10.2% to 14.6% for pure
interimager variability and from 8.6% to 14.3% for interimager variability with
multiple observers. Interimager variability accounted for 96.0% of the overall
variability of average MTR, for 96.7% of peak location, and for 41.1% of the peak
height. The use of different MR scanners is the main source of variability when
obtaining MTR histograms.
PMID- 10669239
TI - Coil occlusion of the parent artery for treatment of symptomatic peripheral
intracranial aneurysms.
AB - BACKGROUND AND PURPOSE: Peripheral intracranial aneurysms can be difficult to
treat with traditional surgical or embolization techniques that spare the parent
vessel. We report the results of our use of coil occlusion of the parent vessel
for the treatment of nine peripheral intracranial aneurysms. METHODS: During
approximately a 4-year period, nine patients (six men and three women, 27 to 68
years old; average age, 42 years) presented to our institution with peripheral
intracranial aneurysms. The aneurysms were located on branches of the right
posterior inferior cerebellar artery (n = 2), the right superior cerebellar
artery (n = 1), the right anterior inferior cerebellar artery (n = 1), the right
posterior cerebral artery (n = 3), the left middle cerebral artery (n = 1), and
the left anterior cerebral artery (n = 1). Parent vessel occlusion was performed
using microcoils after test injection with amobarbital (Amytal) in eight of the
nine cases (one patient was comatose and could not be tested before occlusion).
RESULTS: Angiography immediately after the procedure showed aneurysmal occlusion
in every patient. Follow-up arteriography, performed in six patients 2 to 12
months after treatment, documented continued aneurysmal occlusion in every case.
Three patients exhibited mild, nondisabling neurologic deficits after coil
placement; the rest had no new deficits, although one patient was severely
disabled from the initial hemorrhage and one patient died of an unrelated cause.
CONCLUSION: Our results lend support to the use of parent vessel occlusion for
peripheral aneurysms that are difficult to treat surgically or that are not
amenable to intra-aneurysmal coil placement.
PMID- 10669240
TI - Selective infusion of urokinase and thrombectomy in the treatment of acute
cerebral sinus thrombosis.
AB - Acute cerebral sinus thrombosis caused a patient to decompensate rapidly and
required immediate relief of her venous thrombosis as a life-saving procedure.
The thrombus was laced with urokinase and removed from the sinuses with
thrombectomy catheters. This reinstituted flow and she recovered full neurologic
function within 4 hours.
PMID- 10669241
TI - Quality improvement guidelines for adult diagnostic neuroangiography. Cooperative
study between the ASNR, ASITN, and the SCVIR. American Society of Neuroradiology.
American Society of Interventional and Therapeutic Neuroradiology. Society of
Cardiovascular and Interventional Radiology.
PMID- 10669242
TI - Phase-contrast MR imaging of the cervical CSF and spinal cord: volumetric motion
analysis in patients with Chiari I malformation.
AB - BACKGROUND AND PURPOSE: Most previous MR studies of the dynamics of Chiari I
malformation have been confined to sagittal images and operator-dependent
measurement points in the midline. To obtain a deeper insight into the
pathophysiology of the Chiari I malformation, we performed a prospective study
using axial slices at the level of C2 to analyze volumetric motion data of the
spinal cord and CSF over the whole cross-sectional area. METHODS: Eighteen
patients with Chiari I malformation and 18 healthy control subjects underwent
cardiac-gated phase-contrast imaging. Cross-sectional area measurements and
volumetric flow/motion data calculations were made for the following
compartments: the entire intradural space, the spinal cord, and the anterior and
posterior subarachnoid space. RESULTS: The most striking feature was an increased
early systolic caudal and diastolic cranial motion of the spinal cord in the
patients. CSF pulsations in the anterior subarachnoid space were unchanged at
systole but showed an impaired diastolic upward flow. In the posterior
compartment, the CSF systole was slightly shortened, with an impairment of
diastolic upward flow. Fourteen of the 18 patients had associated syringeal
cavities. This subgroup showed an increased systolic downward displacement of the
cord as compared with patients without a syrinx. CONCLUSION: Obstruction of the
foramen magnum in patients with Chiari I malformation causes an abrupt systolic
downward displacement of the spinal cord and impairs the recoil of CSF during
diastole.
PMID- 10669243
TI - Percutaneous vertebroplasty: a special syringe for cement injection.
AB - Percutaneous vertebroplasty is an effective treatment for many focal vertebral
lesions. Methyl methacrylate is too viscous to be handled without difficulty in
the conventional way because injection time is short. The operator is left with
little time and must fumble with multiple syringes. We describe a special screw
system syringe that decreases the effort needed to inject the cement. In
addition, it can standardize the injection pressures and control the injected
volume because the threaded plunger affords greater control of injection pressure
and volume delivered than does the conventional method.
PMID- 10669244
TI - Vascularization of head and neck paragangliomas: comparison of three MR
angiographic techniques with digital subtraction angiography.
AB - BACKGROUND AND PURPOSE: MR angiography of the head and neck region has been
studied widely, but few studies have been performed concerning the efficacy of MR
angiography for the identification of the specific vascular supply of the highly
vascular head and neck paragangliomas. In this study, we compared three MR
angiography techniques with respect to visualization of branch arteries in the
neck and identification of tumor feeders in patients with paragangliomas.
METHODS: Fourteen patients with 29 paragangliomas were examined at 1.5 T using 3D
phase-contrast (PC), 2D time-of-flight (2D TOF), and multi-slab 3D TOF MR
angiography. In the first part of the study, two radiologists independently
evaluated the visibility of first-, second-, and third-order branch arteries in
the neck. In the second part of the study, the number of feeding arteries for
every paraganglioma was determined and compared with digital subtraction
angiography (DSA), the standard of reference in this study. RESULTS: Three
dimensional TOF angiography was superior to the other MR angiography techniques
studied (P < .05) for depicting branch arteries of the external carotid artery in
the neck, but only first- and second-order vessels were reliably shown. DSA
showed a total of 78 feeding arteries in the group of patients with 29
paragangliomas, which was superior to what was revealed by all MR angiography
techniques studied. More tumor feeders were identified with 3D TOF and 2D TOF
angiography than with 3D PC MR angiography (P < .05), with a
sensitivity/specificity of 61%/98%, 54%/95%, and 31%/95%, respectively.
Sensitivity was lowest for carotid body tumors. CONCLUSION: Compared with intra
arterial DSA, the 3D TOF MR angiography technique was superior to 3D PC and 2D
TOF MR angiography for identifying the first- and second-order vessels in the
neck. With 3D TOF angiography, more tumor feeders were identified than with the
other MR angiography techniques studied. The sensitivity of MR angiography,
however, is not high enough to reveal important vascularization. The sensitivity
of MR angiography is too low to replace DSA, especially in the presence of
carotid body tumors.
PMID- 10669245
TI - Imaging and clinical evaluation of isolated atresia of the oval window.
AB - BACKGROUND AND PURPOSE: Congenital causes of hearing loss in children commonly
are encountered, and imaging aids in diagnosis as well as presurgical evaluation.
Atresia of the oval window not associated with atresia of the external auditory
canal (EAC) is a rare cause of congenital hearing loss in children. We present
the clinical and imaging findings in children with isolated oval-window atresia.
METHODS: Atresia of the oval window was defined as the absence of the structure
with the presence of a bony plate superimposed between the vestibule and middle
ear. The bony plate is within the expected region of the oval window. Using a
computerized database, nine patients with isolated oval-window atresia were
found. All had been evaluated with high-resolution computed tomography (HRCT) and
all had medical records available for review, including audiogram results.
Imaging studies were interpreted by the consensus of two pediatric
neuroradiologists. RESULTS: Atresia of the oval window was documented in all
cases using HRCT criteria. The most common anomalies associated with oval-window
atresia were inferomedial malposition of the facial nerve (n = 8), malformed
incus (n = 6), and displaced stapes (n = 2). Four patients had symmetric
bilateral involvement. Hearing tests were not specific, because conductive,
sensorineural, and mixed patterns were found. CONCLUSION: Anomalies of the oval
window should be sought in all patients with congenital hearing loss. Associated
findings, such as facial nerve aberrancy and ossicular anomalies, are important
in both diagnosis and surgical planning.
PMID- 10669246
TI - Masticator space abnormalities associated with mandibular osteoradionecrosis: MR
and CT findings in five patients.
AB - BACKGROUND AND PURPOSE: Imaging of patients with a clinical diagnosis of
mandibular osteoradionecrosis (ORN) is often performed to support that clinical
suspicion, evaluate the extent of the disease, or exclude coexistent tumor
recurrence. The purpose of our study was to describe the clinical, MR imaging,
and CT features of five patients with mandibular ORN associated with prominent
soft-tissue abnormality in the adjacent masticator muscles. METHODS: The MR and
CT examinations of five patients with mandibular ORN associated with soft-tissue
abnormalities in the adjacent masticator muscles were reviewed. All patients had
received external beam radiotherapy for primary head and neck malignancies, with
a total radiation dose range of 60 Gy to 69 Gy in 30 to 38 fractions. RESULTS: CT
revealed the typical osseous findings of cortical disruption, trabecular
disorganization, and fragmentation in all five patients. Abnormal diffuse
enhancement of the adjacent masseter and pterygoid muscles was noted in all
patients. Four patients had prominent mass-like thickening of these muscles
adjacent to the osseous abnormality. Of the three patients who underwent MR
imaging, all showed homogeneous abnormal T1 hypointensity, T2 hyperintensity, and
intense enhancement of the bone marrow in the involved mandible. The masticator
muscles adjacent to the osseous abnormality also showed abnormal T2
hyperintensity and intense diffuse enhancement on MR images. CONCLUSION:
Mandibular ORN can be associated with prominent soft-tissue thickening and
enhancement in the adjacent musculature. These changes can appear mass-like and
are not related to tumor recurrence or metastatic disease.
PMID- 10669247
TI - Age-related expansion and reduction in aeration of the sphenoid sinus: volume
assessment by helical CT scanning.
AB - BACKGROUND AND PURPOSE: Aeration of the sphenoid sinus expands with the
development of the sphenoid bone, but scant detailed volumetric data regarding
this process, as it evolves from childhood to old age, exist. Using helical CT
scanning, we assessed age-related volumetric changes of the sphenoid sinus.
METHODS: We used CT data obtained from 214 patients (age range, 1 to 80 years;
111 male and 103 female subjects) with middle or inner ear disease to assess the
extent of sphenoid aeration. We also determined volumes of the sphenoid sinuses
on 1.0- or 1.5-mm reformatted images by integrating the sinus air (< or = -900
HU) area. RESULTS: Sphenoid sinus aeration began as a doublet in the anterior
boundary of the sphenoid bone by the age of 5 years, with patients more than 6
years old exhibiting varying degrees of aeration. The aeration on both sides
continued to expand until the third decade of life. The maximum average volume
was 8.2 +/- 0.5 cm3. Thereafter, the volume decreased gradually, with the average
volume in the seventh decade of life being 71% of the maximum level. The aeration
of the peripheral portions of the sphenoid bone, such as the pterygoid process,
anterior clinoid process, and dorsum sella, occurred predominantly after closure
of the spheno-occipital suture, and showed a tendency to recede during aging.
CONCLUSION: Volumetric assessment of the sphenoid sinus by helical CT scanning
revealed age-related expansion and reduction in aeration.
PMID- 10669248
TI - In vivo 1H MR spectroscopy of human head and neck lymph node metastasis and
comparison with oxygen tension measurements.
AB - BACKGROUND AND PURPOSE: Current diagnostic methods for head and neck metastasis
are limited for monitoring recurrence and assessing oxygenation. 1H MR
spectroscopy (1H MRS) provides a noninvasive means of determining the chemical
composition of tissue and thus has a unique potential as a method for localizing
and characterizing cancer. The purposes of this investigation were to measure 1H
spectral intensities of total choline (Cho), creatine (Cr), and lactate (Lac) in
vivo in human lymph node metastases of head and neck cancer for comparison with
normal muscle tissue and to examine relationships between metabolite signal
intensities and tissue oxygenation status. METHODS: Volume-localized Lac-edited
MRS at 1.5 T was performed in vivo on the lymph node metastases of 14 patients
whose conditions were untreated and who had primary occurrences of squamous cell
carcinoma. MRS measurements were acquired also from the neck muscle tissue of six
healthy volunteers and a subset of the patients. Peak areas of Cho, Cr, and Lac
were calculated. Tissue oxygenation (pO2) within the abnormal lymph nodes was
measured independently using an Eppendorf polarographic oxygen electrode.
RESULTS: Cho:Cr ratios were significantly higher in the nodes than in muscle
tissue (node Cho:Cr = 2.9 +/- 1.6, muscle Cho:Cr = 0.55 +/- 0.21, P = .0006). Lac
was significantly higher in cancer tissue than in muscle (P = .01) and, in the
nodes, showed a moderately negative correlation with median pO2 (r = -.76) over a
range of approximately 0 to 30 mm Hg. Nodes with oxygenation values less than 10
mm Hg had approximately twice the Lac signal intensity as did nodes with
oxygenation values greater than 10 mm Hg (P = .01). Cho signal intensity was not
well correlated with pO2 (r = -.46) but seemed to decrease at higher oxygenation
levels (>20 mm Hg). CONCLUSION: 1H MRS may be useful for differentiating
metastatic head and neck cancer from normal muscular tissue and may allow for the
possibility of assessing oxygenation. Potential clinical applications include the
staging and monitoring of treatment.
PMID- 10669249
TI - Idiopathic sclerotic inflammation of the orbit with left optic nerve compression
in a patient with multifocal fibrosclerosis.
AB - We present the MR imaging findings in a 43-year-old male patient with bilateral
idiopathic sclerosing inflammation of the orbit. Bilateral enhancing retrobulbar
masses, with concentric compression of the retrobulbar segment of the left optic
nerve, were seen. MR imaging proved to be the only means to distinguish between
the different intraorbital structures and to determine the exact site of optic
nerve compression. To our knowledge, this is the first documented case of MR
imaging findings of this entity.
PMID- 10669250
TI - Optic nerve cysticercosis: imaging findings.
AB - We present the imaging findings of retrobulbar optic nerve cysticercosis in a 50
year-old woman with a 6-month history of vision loss. Contrast-enhanced CT
revealed an approximately 7-mm ring-enhancing cyst with a mural nodule located in
the anterior portion of the left optic nerve. A contrast-enhanced MR imaging
study revealed a cystic lesion with peripheral enhancement of the mural nodule.
Sonography showed a cystic mass with a focal area of increased echogenicity
corresponding to the mural nodule.
PMID- 10669251
TI - Thermally induced transient trigeminal sensory neuropathy: imaging findings.
AB - We report the clinical and imaging features of a patient with transient partial
trigeminal sensory neuropathy thought to have been induced by thermal injury to
the tongue. Abnormal thickening and enhancement of the mandibular division of the
trigeminal nerve was revealed by MR imaging. The diagnostic considerations for
mass-like enlargement of the trigeminal nerve should include
transient/inflammatory processes, as well as more common and sinister conditions,
such as tumor.
PMID- 10669252
TI - Increased detectability of alpha brain glutamate/glutamine in neonatal hypoxic
ischemic encephalopathy.
AB - BACKGROUND AND PURPOSE: Proton MR spectroscopy (MRS) detectability of brain
glutamate/glutamine (Glx) is increased in hypoxic-ischemic insults and is
implicated in the neuronal injury and death that follows. Our aim was to
correlate the proton MRS detectability of alpha-CH protons of Glx (alpha-Glx)
with the Sarnat stage of neonatal hypoxic-ischemic encephalopathy (HIE). METHODS:
Initial and follow-up proton MRS studies at 1.9 T were performed in 28 neonates
aged 1 to 7 days (seven healthy control subjects and 21 with HIE: 10 mild, nine
moderate, and two severe) and in 12 neonates aged 13 to 17 days (12 with HIE:
eight mild, three moderate, and one severe), respectively. Both point-resolved
spectroscopy (PRESS) and stimulated-echo acquisition mode (STEAM) sequences were
used. The spectral volume of interest was in the basal ganglia, thalami, and
adjoining regions. The detectability of alpha-Glx was assessed by two different
parameters: the detection rate of the alpha-Glx peak and the peak-area ratio of
alpha-Glx to creatine and phosphocreatine. RESULTS: On both the initial and
follow-up PRESS studies, all the neonates with moderate and severe HIE showed an
alpha-Glx peak, compared with one healthy control subject in the initial study
and one neonate with mild HIE in both the studies. They also demonstrated a
significantly higher peak-area ratio of alpha-Glx/(creatine and phosphocreatine)
on both the initial and follow-up studies. The peak-area ratios in neonates with
HIE positively correlated with the Sarnat stage of HIE on both the initial and
follow-up studies. Neonates with moderate and severe HIE also showed a
consistently higher alpha-Glx peak on both the initial and follow-up studies with
the STEAM sequence. CONCLUSION: Proton MRS detectability of alpha-Glx is
increased in moderate and severe HIE and correlates with the Sarnat stage of HIE.
PMID- 10669253
TI - Sonography, CT, and MR imaging: a prospective comparison of neonates with
suspected intracranial ischemia and hemorrhage.
AB - BACKGROUND AND PURPOSE: Sonography, CT, and MR imaging are commonly used to
screen for neonatal intracranial ischemia and hemorrhage, yet few studies have
attempted to determine which imaging technique is best suited for this purpose.
The goals of this study were to compare sonography with CT and MR imaging
prospectively for the detection of intracranial ischemia or hemorrhage and to
determine the prognostic value(s) of neuroimaging in neonates suspected of having
hypoxic-ischemic injury (HII). METHODS: Forty-seven neonates underwent CT (n =
26) or MR imaging (n = 24) or both (n = 3) within the first month of life for
suspected HII. Sonography was performed according to research protocol within an
average of 14.4 +/- 9.6 hours of CT or MR imaging. A kappa analysis of
interobserver agreement was conducted using three independent observers. Infants
underwent neurodevelopmental assessment at ages 2 months (n = 47) and 2 years (n
= 26). RESULTS: CT and MR imaging had significantly higher interobserver
agreement (P < .001) for cortical HII and germinal matrix hemorrhage (GMH)
(Grades I and II) compared with sonography. MR imaging and CT revealed 25
instances of HII compared with 13 identified by sonography. MR imaging and CT
also revealed 10 instances of intraparenchymal hemorrhage (>1 cm, including Grade
IV GMH) compared with sonography, which depicted five. The negative predictive
values of neuroimaging, irrespective of technique used, were 53.3% and 58.8% at
the 2-month and 2-year follow-up examinations, respectively. CONCLUSION: CT and
MR imaging have significantly better interobserver agreement for cortical HII and
GMH/intraventricular hemorrhage and can reveal more instances of intraparenchymal
hemorrhage compared with sonography. The absence of neuroimaging findings on
sonograms, CT scans, or MR images does not rule out later neurologic dysfunction.
PMID- 10669254
TI - Hemangioendothelioma of the parotid gland in infants: sonography and correlative
MR imaging.
AB - BACKGROUND AND PURPOSE: Hemangioendothelioma is the most common parotid gland
tumor of childhood, and is diagnosed on clinical grounds, supported by imaging
findings. Previous work has suggested that MR is the best imaging technique for
assessment of parotid hemangioendothelioma. Demonstration of a reliable
sonographic appearance would reduce the need for MR imaging in infants with this
lesion. METHODS: We performed high-frequency sonography (including color Doppler
and power Doppler imaging) in three patients, each with a diagnosis of parotid
hemangioendothelioma confirmed by clinical follow-up. Two patients were also
examined with MR imaging and labeled red cell scintigraphy. RESULTS: All
sonographic studies showed a homogeneous mass enlarging and replacing most or all
of the visualized parotid gland, with a lobular internal structure, fine
echogenic internal septations, and a mildly lobulated contour. Color Doppler and
power Doppler imaging showed extremely high vascularity within the mass.
Correlative MR images in two infants showed a well-defined lesion with uniform
intense contrast enhancement. Labeled red cell scintigraphy showed a well-defined
area of intense activity. CONCLUSION: In the presence of a typical clinical
history, sonography and clinical follow-up alone may prove to be sufficient for
safe management of parotid hemangioendothelioma. MR imaging or labeled red cell
scintigraphy may only be required if the sonographic features are atypical. These
findings require confirmation in a larger series of patients.
PMID- 10669255
TI - Leigh syndrome in a 3-year-old boy with unusual brain MR imaging and pathologic
findings.
AB - We report unusual MR serial imaging and electron microscopy findings in a 3-year
old boy who had Leigh syndrome with cytochrome-c oxidase (cox) deficiency. The MR
imaging findings included periventricular white matter involvement,
posteroanterior progression, and extension through the corpus callosum and
internal capsule; however, no basal ganglia or brain stem abnormality was found,
which was suggestive of leukodystrophy. The most noteworthy findings were the
cystic foci with contrast enhancement in the affected white matter.
PMID- 10669256
TI - In re: Bydder GM, Steiner RE, Young IR, et al. Clinical NMR imaging of the brain:
140 cases. Am J Reontgenol 1982;139:215-236.
PMID- 10669257
TI - Internal carotid artery narrowing in children with retropharyngeal lymphadenitis
and abscess.
PMID- 10669258
TI - In re: Basilar artery migraine and reversible imaging abnormalities.
PMID- 10669259
TI - Respiratory viral infections in the elderly.
AB - Viral respiratory infections represent a significant challenge for those
interested in improving the health of the elderly. Influenza continues to result
in a large burden of excess morbidity and mortality. Two effective measures,
inactivated influenza vaccine, and the antiviral drugs rimantadine and
amantadine, are currently available for control of this disease. Inactivated
vaccine should be given yearly to all of those over the age of 65, as well as
younger individuals with high-risk medical conditions and individuals delivering
care to such persons. Live, intranasally administered attenuated influenza
vaccines are also in development, and may be useful in combination with
inactivated vaccine in the elderly. The antiviral drugs amantadine and
rimantadine are effective in the treatment and prevention of influenza A,
although rimantadine is associated with fewer side-effects. Recently, the inhaled
neuraminidase inhibitor zanamivir, which is active against both influenza A and B
viruses, was licensed for use in uncomplicated influenza. The role of this drug
in treatment and prevention of influenza in the elderly remains to be determined.
Additional neuraminidase inhibitors are also being developed. In addition, to
influenza, respiratory infections with respiratory syncytial virus, parainfluenza
virus, rhinovirus, and coronavirus have been identified as potential problems in
the elderly. With increasing attention, it is probable that the impact of these
infections in this age group will be more extensively documented. Understanding
of the immunology and pathogenesis of these infections in elderly adults is in
its infancy, and considerable additional work will need to be performed towards
development of effective control measures.
PMID- 10669260
TI - Effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, on the survival of
mice infected with influenza virus.
AB - The antiviral effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, was
investigated using mice infected with influenza virus. TJ-41 was found to
increase the survival rate, prolong the mean survival days, suppress viral growth
in bronchoalveolar labage fluid (BALF) and inhibit the lung index (lung
consolidation) on day 4 after infection in mice infected with influenza, after
the agent had been administered orally once daily from day 7 to 2 before
infection and from day 0 to 4 after infection. Administration of TJ-41 decreased
the BALF concentrations of IL-1alpha, IL-6 and GM-CSF, but not TNF-alpha or
interferon-gamma (IFN-gamma), on day 4 after infection. In addition, TJ-41
elevated the level of IFN-alpha in BALF on day 2 after infection. Yet, TJ-41 did
not show any inhibitory effect on the growth of influenza virus in vitro. These
results suggest that TJ-41 exerts its inhibitory effect on influenza virus
infection via enhancement of the host immune responses in this experimental
murine system.
PMID- 10669261
TI - Antiviral properties of a mangrove plant, Rhizophora apiculata Blume, against
human immunodeficiency virus.
AB - A polysaccharide extracted from the leaf of Rhizophora apiculata (RAP) was
assessed in cell culture systems, for its activity against human and simian
immunodeficiency viruses. RAP inhibited HIV-1 or HIV-2 or SIV strains in various
cell cultures and assay systems. It blocked the expression of HIV-1 antigen in MT
4 cells and abolished the production of HIV-1 p24 antigen in peripheral blood
mononuclear cells (PBMC); the 50% effective concentration (EC50) of RAP in HIV-1
infected MT-4 cells and in PBMC was 10.7 and 25.9 microg/ml, respectively. RAP
(100 microg/ml) completely blocked the binding of HIV-1 virions to MT-4 cells.
RAP also reduced the production of viral mRNA when added before virus adsorption.
RAP inhibited syncytium formation in cocultures of MOLT-4 cells and MOLT-4/HIV
1(IIIB) cells. RAP did not prolong activated partial thromboplastin time (APTT)
up to 500 microg/ml. These properties may be advantageous should RAP be
considered for further development.
PMID- 10669262
TI - Inhibitory effect of dibenzofuran and dibenzosuberol derivatives on rhinovirus
replication in vitro; effective prevention of viral entry by dibenzosuberenone.
AB - A series of derivatives of dibenzofuran and dibenzosuberol block rhinovirus
replication in vitro as judged by their ability to hinder the cytopathic effect
in cells infected with HRV14 or HRV16. Both the number and the size of viral
plaques were reduced effectively by treatment with these compounds in a dose
dependent fashion, thus affecting viral spread. The compound 2-hydroxy-3
dibenzofuran carboxylic acid was equally effective against HRV16 and HRV14, with
IC50 values of 25 microM in cytopathy assays. Dibenzosuberenone showed minor
differences in selectivity, with IC50 values of 10 and 30 microM for HRV16 and
HRV14 cytopathy, respectively. Likewise, dibenzosuberenone effectively prevented
the production of HRV16 proteins, viral RNA, and infectious virus particles when
present at concentrations above 30 microM. Time-of-addition experiments show that
compounds must be administered before or during the viral adsorption step in
order to be effective antivirals. Dibenzosuberenone can block the adsorption of
viral particles on to cells, preventing further steps in the replication cycle,
but is not effective as a direct inactivating agent. These compounds likely
interact with viral capsid proteins, affecting receptor interactions required for
attachment and subsequent entry into cells.
PMID- 10669263
TI - Heterotypic inhibition of foot-and-mouth disease virus infection by combinations
of RNA transcripts corresponding to the 5' and 3' regions.
AB - Strategies to inhibit RNA virus multiplication based on the use of interfering
nucleic acids have to consider the high genetic polymorphism exhibited by this
group of viruses. Here, we report high levels of heterotypic inhibition of foot
and-mouth disease virus (FMDV) infective particle formation in cotransfection
experiments of susceptible cell lines with infections viral RNA and combinations
of viral transcripts. The interfering molecules used include the following
regions on type C FMDV RNA: (i) sequences from the 5' region, spanning the
proximal part of the internal ribosome entry site element and the two functional
initiator AUGs; and (ii) the 3' terminal region including the 3' end of 3D gene
and the complete 3' non-coding region. Combination of 5' antisense RNA molecules
with either sense or antisense RNA molecules from the 3' region resulted in
inhibition of up to 90% of the infectivity of homologous type C FMDV RNA. The
inhibition was dose-dependent and specific, as no reduction was observed in the
plaque-forming units recovered from RNA of swine vesicular disease virus, a
related picornavirus. Interestingly, high levels-of intertypic inhibition, about
60% or higher, were observed when viral RNAs of serotypes O and A were analysed.
These levels of inhibition are consistent with the levels of nucleotide homology
exhibited by the viruses analysed in the target sequences. Inhibition of virus
yield was also observed in FMDV-infected cells transiently expressing the
interfering RNAs. Thus, transcripts of the FMDV RNA corresponding to the 5' and
3' regions specifically inhibit FMDV particle formation in a serotype-independent
manner.
PMID- 10669264
TI - Anaesthesiology into the new millenium.
PMID- 10669265
TI - PaO2 during anaesthesia and years of smoking predict late postoperative
hypoxaemia and complications after upper abdominal surgery in patients without
preoperative cardiopulmonary dysfunction.
AB - BACKGROUND: The incidence of late postoperative hypoxaemia and complications
after upper abdominal surgery is 20-50% among cardiopulmonary healthy patients.
Atelectasis development during anaesthesia and surgery is the main hypothesis to
explain postoperative hypoxaemia. This study tested the predictive value of
PaO2<19 kPa during combined general and thoracic epidural anaesthesia and the
preoperative functional residual capacity (FRC) reduction in the 30 degree head
tilt-down position for the development of late prolonged postoperative
hypoxaemia, PaO2<8.5 kPa for a minimum of 3 out of 4 days, and other
complications. Forty patients without cardiopulmonary morbidity, assessed by ECG,
spirometry, FRC and diffusion capacity preoperatively, underwent upper abdominal
surgery. PaO2 during anaesthesia and preoperative FRC reduction were compared to
known risk factors for the development of hypoxaemia and complications: age, pack
years of smoking and duration of operation. The effect of optimizing pulmonary
compliance with peroperative positive end-expiratory pressure (PEEP) on
postoperative hypoxaemia and complications was evaluated in a blinded and
randomized manner. RESULTS: Late prolonged postoperative hypoxaemia and other
complications were found in 37% and 38% of the patients, respectively. Patients
with PaO2>19 kPa during anaesthesia with F(I)O2=0.33 exhibited a risk,
irrespective of PEEP status, of suffering late prolonged hypoxaemia of 0% (0;23)
and patients with PaO2<19 kPa a risk of 52% (32;71), P<0.005. Having smoked more
than 20 pack-years was associated with a 47% (19;75) higher incidence of
postoperative complications than having smoked less than 20 pack-years, P<0.006.
CONCLUSIONS: PaO2 during anaesthesia and smoked pack-years provide new tools
evaluating patients undergoing upper abdominal surgery in order to predict the
patients who develop late postoperative hypoxaemia and complications.
PMID- 10669266
TI - Lipid peroxidation induced by an early inflammatory response in endotoxaemia.
AB - BACKGROUND: Endotoxaemic challenge promptly causes lipid peroxidation. Porcine
endotoxaemia can be used to replicate severe human septic shock. This model was
used to evaluate non-enzymatic [8-Iso-prostaglandin F2alpha (8-Iso-PGF2alpha)]
and enzymatic [15-keto-13,14-dihydro-prostaglandin F2alpha (15-K-DH-PGF2alpha)]
lipid peroxidation, respectively, in relation to survival. The aim of this study
was to correlate, if possible, pathophysiologic events during endotoxaemia to the
levels of these arachidonic acid metabolites. METHODS: Nineteen pigs were
anaesthetised, monitored (circulatory and respiratory variables in relation to
lipid peroxidation) and given a continuous 6 h E. coli endotoxin (10 microg x kg(
1) x h(-1)) infusion. All animals were mechanically ventilated at constant tidal
volumes and the inspired oxygen fraction was kept constant during the
experimental period. RESULTS: This endotoxin infusion caused expressed
derangements in all pigs and death in 9 of them. The levels of 8-Iso-PGF2alpha,
indicating oxidative injury, were different in time course, magnitude and fashion
between survivors and non-survivors. The levels of 15-K-DH-PGF2alpha, indicating
inflammatory response, showed a similar pattern. At 1 h the CO2 partial pressure
in arterial blood was significantly higher in non-surviving pigs and correlated
(r: 0.7; P<0.05) to the levels of 15-K-DH-PGF2alpha. Prostaglandin F2alpha is
mainly metabolised in the lung. The lung weights were significantly (P<0.05)
higher in non-surviving than in surviving animals. Both free radical and
cyclooxygenase catalysed oxidative modification occurs during endotoxaemia.
CONCLUSION: Increased metabolism and inflammation, as evaluated by 15-K-DH
PGF2alpha, in the group of non-survivors may mediate the increase in arterial
CO2. Thus, increased lipid peroxidation seems to be associated with endotoxaemic
organ dysfunction and increased mortality.
PMID- 10669267
TI - Effects of melagatran, an inhibitor of thrombin, on fibrin deposits,
haemodynamics, and platelet count in endotoxaemic pigs.
AB - BACKGROUND: Thrombin plays a pivotal role in the development of septic shock.
Porcine endotoxaemia can replicate this condition. We wanted to evaluate whether
melagatran, a novel inhibitor of thrombin, would counteract some of the endotoxin
induced changes in this model. METHODS: Fifteen pigs were anaesthetised,
monitored (circulatory and respiratory variables) and subjected to an infusion of
E. coli endotoxin at 10 microg x kg(-1) x h(-1). Six pigs were given melagatran
during the first 3 h of the 6-h endotoxaemic period. Nine controls were given the
corresponding volume of saline instead of melagatran. Specimens from the liver
and the left lung were taken for light microscopy post mortem. RESULTS: The
endotoxin-induced increase in pulmonary capillary wedge pressure and drop in
platelet count were significantly less pronounced in the melagatran-treated pigs.
Deposits of pulmonary fibrin were significantly reduced in the melagatran group,
without improving oxygenation. Light microscopy revealed no hepatic fibrin in the
pigs treated with melagatran in contrast to the endotoxaemic controls. Hepatic
neutrophil accumulation was reduced in the melagatran group as compared to
controls. Hepatocellular degeneration and plasma levels of tumour necrosis factor
alpha (TNF alpha) and bilirubin were of the same magnitude in both groups.
CONCLUSION: Melagatran reduced pulmonary capillary wedge pressure, a retrograde
reflection of the left ventricular end-diastolic filling pressure, and also
pulmonary stasis in pigs subjected to endotoxaemic challenge. Pulmonary and
hepatic fibrin depositions were reduced, but PaO2 levels or liver function
markers were not affected by melagatran during the early phase of endotoxaemia.
Obstruction of the intrahepatic bile ducts, by fibrin depositions, is not
responsible for reduced excretion of conjugated bilirubin during endotoxaemia.
The beneficial effects of melagatran during endotoxaemia were not due to any
reduction of plasma TNF alpha.
PMID- 10669268
TI - Dual mode antimony electrode for simultaneous measurements of PO2 and pH.
AB - BACKGROUND: In biomedical research and clinical medicine there is a demand for
potent sensors to measure the components that make up blood gas analyses. Today,
as when the electrochemical PO2, PCO2 and pH electrodes were first introduced,
these measurements are usually made with the same type of sensor technology. The
aims of the present study were, firstly, to find out whether the platinum cathode
in the Clark electrode can be replaced by antimony for oxygen measurements
(amperometry (A)); secondly, whether, during oxygen measurements, the inherent
corrosion potential of the antimony metal can be used for measurement of pH in
the same measurement area (potentiometry (P)). METHODS: An electrode of purified,
crystallographically orientated monocrystalline antimony (COMA) connected to a
reference electrode (silver-silver chloride) was used for the P measurements.
Measurements of A (at -900 mV) and P were made in an aqueous environment
regulated for oxygen, pH, and temperature. RESULTS: Reproducible oxygen
sensitivities of 0.925 nA/% oxygen (2% CV (coefficient of variation)) (A), 10.7
mV/% (P), and 0.7 mV/% (P) were found in the oxygen range: 0-21%, <5%, and above
5%, respectively. The pH sensitivity was 57 mV/pH unit (P). Oxygen and pH
measurements were less accurate at oxygen concentrations close to 0%.
CONCLUSIONS: Both the oxygen and pH part of the composite electrode signal can be
identified by this dual mode technique (A and P). The sensor seems to be
promising as it provides measurements of two separate variables (oxygen and pH)
and also has the desirable characteristics of a solid state sensor.
PMID- 10669269
TI - Continuous epidural analgesia with bupivacaine-fentanyl versus patient-controlled
analgesia with i.v. morphine for postoperative pain relief after knee ligament
surgery.
AB - BACKGROUND: Both epidural analgesia and intravenous patient-controlled analgesia
(PCA) have been found efficacious after various types of surgery. We compared the
efficacy, safety, side effects and patient satisfaction of these methods in a
randomized double-blind fashion after elective anterior cruciate ligament
reconstruction of the knee. METHODS: Fifty-six patients had an epidural catheter
placed at the L2-L3 interspace. Spinal anaesthesia with 15 mg of plain
bupivacaine 5 mg/ml was performed at the L3-L4 interspace. After surgery the
patients were randomly divided into three groups: 19 received a continuous
epidural infusion with bupivacaine 1 mg/ml and fentanyl 10 mg/ml (F10), 19
patients received bupivacaine 1 mg/ml and fentanyl 5 microg/ml (F5) and 18
patients received saline (S). The rate of the epidural infusions was 0.1 ml kg(
1) h(-1). Each patient could also use an intravenous (i.v.) PCA device with 40
microg/kg bolus doses of morphine with a lockout period of 10 min and a maximum
dose 240 microg kg(-1) h(-1). At the end of surgery ketoprofen 100 mg i.v. was
given and continued orally three times a day. Patients were assessed for pain
with a visual analogue scale (VAS) at rest and during activity, side effects and
satisfaction at 3, 9 and 20 h. RESULTS: Both epidural infusions (F10, F5)
provided better analgesia than epidural saline plus i.v. PCA (S) (P<0.05). There
was slightly less nausea in the S group (NS). In spite of the difference in the
quality of pain relief, there was no difference between the groups in patient
satisfaction regarding analgesic therapy. CONCLUSION: Epidural infusion of
fentanyl (1 microg kg(-1) h(-1) or 0.5 microg kg(-1) h(-1)) and bupivacaine (0.1
mg kg(-1) h(-1)) provided better pain relief but more side effects than
intravenous morphine patient-controlled analgesia after knee ligament surgery.
Almost all patients in all groups were satisfied with their pain relief.
PMID- 10669270
TI - Patient-controlled versus nurse-controlled pain treatment after coronary artery
bypass surgery.
AB - BACKGROUND: Pain after coronary artery bypass surgery persists for several days.
A continuous intravenous infusion of an opioid adequately accomplishes good pain
control in the intensive care unit, but it is often not suitable on the ordinary
ward. Patient-controlled analgesia (PCA) with intermittent injections delivered
by one of the new devices now available could be an alternative to conventional
nurse-controlled analgesia (NCA) based on intermittent injections. The aim was to
compare these two techniques with respect to efficacy and the amount of opioid
used. METHODS: Forty-eight patients randomly received PCA or NCA with
ketobemidone following extubation after coronary artery bypass grafting. Drug
consumption, pain assessment with the visual analogue score (VAS) and possible
side effects were evaluated from extubation to the end of the second
postoperative day. RESULTS: On the day of surgery the VAS scores did not differ
between the groups. From the afternoon of the first postoperative day the VAS
scores were higher in the NCA group with mean values at 3-4 out of 10 as compared
with mean values around 2 in the PCA group (P<0.01). During the study period the
patients in the PCA group received more ketobemidone as compared with the NCA
group, 61.9+/-24.0 mg and 36.3+/-20.2 mg, respectively (P<0.01). Additional oral
analgesics were used in 12 of the patients in the NCA group compared with none in
the PCA group. The few side effects reported were equally distributed between the
two groups. CONCLUSION: PCA treatment after coronary artery bypass surgery
resulted in better pain treatment and the use of more opioid without an increase
in side effects compared with traditional NCA treatment.
PMID- 10669271
TI - Bradycardia and asystolic cardiac arrest during spinal anaesthesia: a report of
five cases.
AB - Sudden, severe bradycardia/asystolic cardiac arrest are considered infrequent,
but are certainly the most serious complications of spinal anaesthesia. We report
four cases of primary asystole and one of severe bradycardia in young to middle
aged, healthy patients scheduled for minor surgery at the day surgery unit.
Bradycardia/asystole were not related to respiratory depression or
hypoxaemia/hypercarbia; they occurred at different time intervals after the onset
of spinal anaesthesia (10-70 min) and, apparently, were not dependent on the
level of sensory block, which varied between T3 and T8. One patient was nauseated
seconds before the asystole, otherwise there was no warning signs. All the
patients were easily resuscitated with the prompt administration of atropine and
ephedrine and, in the case of cardiac arrest, cardiac massage and ventilation
with oxygen. One patient was treated with a small dose of adrenaline. Four
patients had the surgery, as planned; one had the surgery postponed. All the
patients were discharged from hospital in good health and did not suffer any
sequelae.
PMID- 10669272
TI - The effects of clonidine on ropivacaine 0.75% in axillary perivascular brachial
plexus block.
AB - INTRODUCTION: The new long-acting local anesthetic ropivacaine is a chemical
congener of bupivacaine and mepivacaine. The admixture of clonidine to local
anesthetics in peripheral nerve block has been reported to result in a prolonged
block. The aim of the present study was to evaluate the effects of clonidine
added to ropivacaine on onset, duration and quality of brachial plexus block.
METHODS: Patients were randomly allocated into two groups. In group I brachial
plexus was performed using 40 ml of ropivacaine 0.75% plus 1 ml of NaCL 0.9%, and
in group II brachial plexus was performed using 40 ml of ropivacaine 0.75% plus 1
ml (0.150 mg) of clonidine. Onset of sensory and motor block of radial, ulnar,
median and musculocutaneous nerve were recorded. Motor block was evaluated by
quantification of muscle force, according to a rating scale from 6 (normal
contraction force) to 0 (complete paralysis). Sensory block was evaluated by
testing response to a pinprick in the associated innervation areas. Finally, the
duration of the sensory block was registered. Data were expressed in mean+/-SD.
For statistical analysis a Student t-test was used. A P-value of < or = 0.05 was
considered as statistically significant. RESULTS: The duration of blockade was
without significant difference between the groups. Group I: 718+/-90 min; Group
II: 727+/-117 min. There was no intergroup difference in sensory and motor onset
or in quality of blockade. CONCLUSION: The addition of clonidine to ropivacaine
0.75% does not lead to any advantage of block of the brachial plexus when
compared with pure ropivacaine 0.75%.
PMID- 10669273
TI - Pain intensity and pain relief after surgery. A comparison between patients'
reported assessments and nurses' and physicians' observations.
AB - BACKGROUND: Postoperative pain remains a problem for many patients. One of the
reasons could lie in the insufficient evaluation of pain and analgesia. This
study was designed to obtain more insight in the performance of nurses and
physicians in evaluating patients' postoperative pain and pain relief. METHODS:
Forty patients hospitalised in one surgical unit and the 8 nurses and the 2
surgical residents in charge of this unit were investigated. Patients were asked
to assess on a visual analogue scale the intensity of their pain and their pain
relief at rest, on coughing and globally since the operation, on the first and
second postoperative days and the day before hospital discharge. Separately, the
nurses and the physicians were asked to evaluate the pain intensity and the pain
relief for each patient involved. A MANOVA and a multiple comparisons test with
Bonferroni adjustment were used. RESULTS: At rest, only nurses underestimated
pain intensity on the day before hospital discharge. On coughing, physicians
underestimated pain intensity in all 3 assessments, whereas nurses only in the
3rd assessment (on the day before hospital discharge). Globally, physicians
underestimated pain intensity in all 3 assessments, nurses in the 2nd and the 3rd
assessment. Only physicians overestimated pain relief on coughing on the day
before hospital discharge and globally in all 3 assessments. Surprisingly, the
pain scores rated by the patients before hospital discharge were high.
CONCLUSION: The results of this survey suggest that assessment of pain and pain
relief is inadequately done by both physicians and nurses. This emphasises the
importance of a better training, and a systematic assessment of pain intensity
and pain relief.
PMID- 10669274
TI - Pre-incisional epidural ketamine, morphine and bupivacaine combined with epidural
and general anaesthesia provides pre-emptive analgesia for upper abdominal
surgery.
AB - BACKGROUND: Previous studies have shown that N-methyl-D-asparate (NMDA) receptor
antagonists provide a pre-emptive analgesic effect in humans. This study
investigated the benefits of pre-emptive analgesia for upper abdominal surgery,
using pre-incisional epidural ketamine + morphine + bupivacaine (K+M+B) treatment
for achieving postoperative pain relief. METHODS: Sixty ASA 1-2 patients
scheduled for upper abdominal surgery were allocated to three groups in a
randomized, single-blinded study. Patients in the control group (I) received
general anaesthesia followed by an infusion of normal saline. Group II and III
patients received general anaesthesia with a continuous epidural infusion of 2%
lidocaine. Thirty minutes after the incision in groups I and II, an epidural pain
control regimen was administered using ketamine (10 mg) and morphine (1 mg) in 10
ml of 0.085% bupivacaine (K+M+B). Group III patients also received K+M+B, but it
was administered 10 min after the 2% lidocaine injection and 30 min before skin
incision. All patients received an epidural pain control regimen (q12 h) for 3
days after their first injection. Patient-controlled analgesia (PCA) with
morphine was used to control subsequent postoperative pain. During the 3-day
period following surgery, duration to PCA trigger (h), morphine consumption (mg),
pain intensity at rest and when coughing/moving, and analgesic-related adverse
effects were recorded. The VAS scale (0-10) was used to assess pain intensity.
RESULTS: Median times to first PCA trigger were 1.2 (0.5-2.0) h, 3.0 (0.7-4.2) h,
and 4.0 (2.5-7.5) h for groups I, II, and III, respectively. Both the incident
and resting pain scores were consistently lower for group III patients than
groups I and II. The number of PCA triggers (all attempts/successful triggers)
during the day following surgery were 14.0 (3-30)/8.0 (3-24) times, 10.0 (3
23)/6.0 (2-20) times, and 7.0 (3-12)/4.5 (1-10) times for groups I, II, and III.
Total morphine consumption for the 3-day observation period was 12.5 (3-42) mg,
10.5 (2-29) mg, and 6.0 (1-20) for groups I, II, and III, respectively.
CONCLUSION: Pre-incisional epidural K+M+B treatment combined with continuous
epidural anaesthesia and general anaesthesia provides an ideal pre-emptive
analgesic therapy, exhibiting better postoperative pain relief than general
anaesthesia and post-incisional K+M+B treatment.
PMID- 10669275
TI - Platelet dysfunction after intravenous ketorolac or propacetamol.
AB - BACKGROUND: Paracetamol is a weak cyclo-oxygenase inhibitor in vitro. A recent
study in children has shown that high doses of paracetamol are effective and
safe. We studied the effect of propacetamol on haemostasis in adult volunteers.
METHODS: Ten volunteers were investigated in a double-blind, randomized,
crossover study. They received propacetamol 60 mg kg(-1) or ketorolac 0.4 mg kg(
1) in saline i.v. (30 min) in two different sessions. Platelet function was
evaluated before the test infusion (S-0), two (S-2) and 24 h (S-24) after the
start of the infusion. Coagulation parameters (PT, APTT, factor V and VII
activities) were measured at S-0, S-24 and 48 h (S-48). RESULTS: One of the
volunteers had no secondary platelet aggregation in S-0 and was excluded from the
final analysis. Two hours (S-2) after propacetamol and ketorolac administration
the adrenaline (0.9 microg ml(-1) and 9.0 microg ml(-1)) induced maximal platelet
aggregation was decreased compared with S-0. At S-2 platelet aggregation was
inhibited more after ketorolac than after propacetamol. At 24 h after ketorolac,
but not after propacetamol, there was still a decrease in the adrenaline-induced
maximal platelet aggregation. Propacetamol did not affect adenosine diphosphate
(ADP)-induced maximal platelet aggregation, whereas ketorolac decreased 3 and 6
microM ADP-induced maximal platelet aggregation at S-2 and S-24. However, 2 h
after both ketorolac and propacetamol, thromboxane B2 (TxB2) concentration
decreased in platelet rich plasma after 5 min aggregation induced by 8 microM
ADP. Coagulation was unaffected. CONCLUSION: Propacetamol 60 mg kg(-1) i.v.
causes reversible platelet dysfunction demonstrated by a decrease in maximal
platelet aggregation and TxB2 concentration. After 0.4 mg kg(-1) ketorolac i.v.
platelet aggregation and TxB2 formation are inhibited more in comparison with
propacetamol, and platelet dysfunction is still seen after 24 h.
PMID- 10669276
TI - Effects of conventional physiotherapy, continuous positive airway pressure and
non-invasive ventilatory support with bilevel positive airway pressure after
coronary artery bypass grafting.
AB - BACKGROUND: Coronary artery bypass graft (CABG) surgery with the use of mammary
arteries is associated with severe alteration of lung function parameters. The
purpose of the present study was to compare the effect on lung function tests of
conventional physiotherapy using incentive spirometry (IS) with non-invasive
ventilation on continuous positive airway pressure (CPAP) and with non-invasive
ventilation on bilevel positive airway pressure (BiPAP or NIV-2P), METHODS:
Ninety-six patients were randomly assigned to 1 of 3 groups: NIV-2P (1 h/3 h),
CPAP (1 h/3 h) and IS (20/2 h). Pulmonary function tests and arterial blood gases
analyses were obtained before surgery. On the 1st and 2nd postoperative days,
these parameters were collected together with cardiac output and calculation of
venous admixture. RESULTS: For the 3 groups a severe restrictive pulmonary defect
was observed during the 1st postoperative day. On the 2nd postoperative day, in
opposition to IS, intensive use of CPAP and NIV-2P reduced significantly the
venous admixture (P<0.001) and improved VC, FEV1 and PaO2 (P<0.01). CONCLUSION:
We conclude that preventive use of NIV can be considered as an effective means to
decrease the negative effect of coronary surgery on pulmonary function.
PMID- 10669277
TI - Dysregulation of immune response following neurosurgical operations.
AB - BACKGROUND: Postoperative infections are common and potentially fatal
complications in neurosurgical intensive care medicine. An impairment of immune
function has been described after central nervous system surgery and in patients
harboring malignant brain tumors. The aim of our study was to investigate whether
differences in cell-mediated immunity can be found in patients undergoing
craniotomy for surgery of glioblastoma or clipping of an intracerebral aneurysm.
METHODS: In order to determine the influence of the underlying disease on the
immune system, we measured changes in cytokine concentrations (IL-6, IL-10, TGF
beta1) and lymphocyte-subsets (CD3+, CD3+HLA-DR+, CD4+, CD8+, CD19+, and
CD16+56+) in 8 patients with glioblastoma and in 8 patients with an intracerebral
aneurysm before, during and after the neurosurgical procedure. RESULTS: In the
comparison of glioblastoma and aneurysm patients, we could show that IL-6 plasma
levels were pre- and intraoperatively higher in the aneurysm-group (P<0.05), and
the plasma concentrations of IL-10 and TGF-beta were significantly elevated in
the glioma-group. The lymphocyte-subsets showed a significantly lower percentage
of NK-cells and activated T-cells in the glioma-group. CONCLUSION: Our results
document a significant dysregulation of immune response in glioma patients. This
may be induced by elevated plasma concentrations of immunoinhibiting cytokines IL
10 and transforming growth factor-beta 1.
PMID- 10669278
TI - Effect of pentaglobin and piperacillin on survival in a rat model of faecal
peritonitis: importance of intervention timings.
AB - BACKGROUND: Faecal peritonitis is a progressive pathophysiological condition
which may lead to multiple organ failure and death. The reason for the associated
morbidity and mortality could be attributed to the fact that some of the subtle
alterations in cellular function that occur during the early stage of peritonitis
are unidentified and consequently missed, leading to inadequate or delayed
intervention. Recent studies have shown that early treatment with antibiotic and
antisera containing antibodies to lipopolysaccharide (immunoglobulin) improve the
survival rate in these patients. The present investigation was undertaken to
study the effect of pentaglobin and piperacillin with particular attention to
time lag of drug intervention on animal survival following experimental
peritonitis. METHODS: Experimental peritonitis was produced by inoculating 1
ml/kg of faecal suspension (2:1 w/v in saline) into the peritoneal cavity. Two
groups of animals were treated with pentaglobin (4 ml/kg) or piperacillin (1000
mg/kg) respectively, whereas rats in another group received both drugs
simultaneously. The first dose of each drug was given at 4 h, 6 h, 8 h and 12 h
after faecal inoculation followed by 3 additional doses at 8-h intervals. For
biochemical studies, separate groups of animals were used in which the treatment
was started 4 h after faecal inoculation and the animals were killed at 12 h
after the treatment. RESULTS: Both piperacillin and pentaglobin prolonged
survival time of animals which received the treatment within 6 h of faecal
insult. The combination of pentaglobin plus piperacillin produced better results
as compared to the individual effect. There was a significant decrease in serum
superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and increase in
catalase following faeces-induced septicaemia, suggesting a significant increase
in oxidative stress. The changes in enzyme levels were significantly attenuated
by both the drugs. CONCLUSION: The findings suggest that intervention with a
combination of pentaglobin and antibiotics within 6 h of peritonitis might
significantly improve survival rate in rat.
PMID- 10669279
TI - Nitric oxide does not play a major role in the regulation of systemic hemodynamic
responses to acute normovolemic hemodilution.
AB - BACKGROUND: The mechanisms of cardiovascular changes following acute normovolemic
hemodilution (ANH) have not been fully elucidated. We tested the hypothesis that
inhibition of nitric oxide synthesis attenuates ANH-induced cardiovascular
responses. METHODS: We observed the effects of N(omega)-nitro-L-arginine methyl
ester (L-NAME) pretreatment on ANH-induced cardiovascular responses and compared
these effects with those elicited by phenylephrine (PHE). Twenty dogs
anesthetized with isoflurane were divided into two groups: one group was
pretreated with L-NAME and the other with PHE. Both groups were normovolemically
hemodiluted using 6% hydroxyethyl starch to reduce the hemoglobin concentration
to approximately 50% of the pretreatment value. RESULTS: Pretreatment with either
L-NAME or PHE caused a significant increase in mean aortic blood pressure (MAP)
and systemic vascular resistance (SVR) with a significant decrease in cardiac
output (CO) and stroke volume (SV). However, no remarkable differences in these
variables were seen between groups. In both groups ANH produced increases in
heart rate, CO, SV, and maximal left ventricular dP/dt with a significant
decrease in SVR. No significant differences in these variables were apparent
after ANH except that MAP was decreased in the PHE group but not in the L-NAME
group. CONCLUSION: Our results suggest that nitric oxide does not play a major
role in mediation or modulation of the systemic vascular responses to ANH.
PMID- 10669280
TI - Recovery characteristics of sevoflurane or halothane for day-case anaesthesia in
children aged 1-3 years.
AB - BACKGROUND: Our objective was to compare the recovery characteristics of
sevoflurane and halothane for short day-case anaesthesia in a specifically
limited age group of children 1-3 yr. METHODS: Eighty unpremedicated children
undergoing day-case adenoidectomy were randomly assigned to receive inhalational
induction with either sevoflurane 8% or halothane 5% and nitrous oxide in oxygen
(70/30) via a face mask. Tracheal intubation was performed without a muscle
relaxant. Anaesthesia was continued with the volatile anaesthetic, adjusted to
maintain heart rate and blood pressure within +/-20% of initial values. Recovery
was evaluated using a modified Aldrete score, a Pain/Discomfort scale and by
measuring recovery end-points. A postoperative questionnaire was used to
determine the well-being of the child at home until 24 h after discharge.
RESULTS: Emergence and interaction occurred significantly earlier after
sevoflurane than halothane but discharge times were similar. More children in the
sevoflurane group achieved full Aldrete scores within the first 30 min after
anaesthesia, although this group suffered more discomfort during the first 10
min. The amount of postoperative analgesic administered was higher and the first
dose given earlier in the sevoflurane group. Postoperative vomiting was more
common with halothane, but side-effects in the two groups were otherwise similar
in the recovery room and at home. CONCLUSIONS: In children 1-3 yr, sevoflurane
provided more rapid early recovery but not discharge after anaesthesia of <30-min
duration. Apart from more vomiting with halothane and more discomfort during the
first 10 min after awakening with sevoflurane, the quality of recovery was
similar with the two anaesthestics.
PMID- 10669281
TI - Intramuscular ephedrine reduces emesis during the first three hours after
abdominal hysterectomy.
AB - BACKGROUND: We tested the hypothesis that intramuscularly administered ephedrine
prevents postoperative nausea and vomiting. Ephedrine is cheap, and for this
indication poorly documented. METHODS: One hundred and nine patients undergoing
elective abdominal hysterectomy under general anaesthesia were studied in a
randomized, double-blind placebo-controlled study. Ten minutes before the end of
the procedure patients received either ephedrine 0.5 mg/kg i.m. or placebo. The
patients were closely observed for 24 h for postoperative nausea or vomiting
(PONV) and received a standardized two-step antiemetic treatment of i.v.
metoclopramide 10 mg, supplemented with ondansetron 4 mg i.v. if needed. RESULTS:
The ephedrine treated patients had significantly less nausea, retching and
vomiting, and need of antiemetic rescue during the first 3 h postoperatively
compared with the placebo patients. No difference between the groups was evident
in the 3-24 h postoperative observation period. All the patients with PONV during
0-3 h experienced PONV in the 3-24 h period. Treatment or prophylaxis with one
drug was less efficient than two or more drugs combined. No significant
differences in hypotension, tachycardia or other side-effects between the groups
were noted. CONCLUSION: Ephedrine 0.5 mg/kg i.m. administered at the end of
abdominal hysterectomy has a significant antiemetic effect during the first 3 h
after administration with no evident side-effects.
PMID- 10669282
TI - Age-related modifications of effects of ketamine and propofol on rat hippocampal
acetylcholine release studied by in vivo brain microdialysis.
AB - BACKGROUND: We sometimes encounter impairment of learning and memory after
general anesthesia in elderly patients. The aim of this study was to examine age
related modifications of the effects of ketamine and propofol on rat hippocampal
acetylcholine (ACh) release because hippocampal cholinergic neurons are supposed
to be involved in learning and memory. METHODS: The experiments were performed on
male Wistar young rats (2 months old) and old rats (18 months old), using in vivo
brain microdialysis technique under freely moving condition. After initial
sampling of three collections, test drugs were administered. The ACh release was
determined by the HPLC-ECD method. RESULTS: In old rats, the hippocampal basal
ACh release was significantly lower than in young rats. Ketamine (25 and 50 mg
kg(-1) i.p.) increased and propofol (25 and 50 mg kg(-1) i.p.) decreased the
hippocampal ACh release in both young and old rats. Furthermore, ketamine 50 mg
kg(-1) i.p. (anesthetic dose) produced facilitatory effects on the hippocampal
ACh release in young rats (193% of the basal release), while in old rats the same
dose of ketamine i.p. produced more pronounced facilitatory effects on the
hippocampal ACh release (317% of the basal release). On the other hand, propofol
50 mg kg(-1) i.p. (anesthetic dose) produced inhibitory effects on the
hippocampal ACh release in young rats (56% of control) and in old rats (77% of
control). Although the maximal inhibitory peak effects of propofol 50 mg kg(-1)
i.p. did not differ significantly between young rats and old rats, decrease of
the hippocampal ACh release in old rats persisted longer than in young rats.
CONCLUSION: Ketamine produced more pronounced facilitatory effects on the
hippocampal ACh release in old rats, as compared with young rats. On the other
hand, propofol has inhibitory effects on the hippocampal ACh release in young and
old rats. The aging process may suppress the ability to recover from the
inhibitory anesthetic state induced by propofol.
PMID- 10669284
TI - Intermittent atrial level right-to-left shunt with temporary hypoxemia in a
patient during support with a left ventricular assist device.
AB - We report a 56-year-old male patient developing hypoxemia after surgical
replacement of infected valves of a left ventricular assist device (LVAD,
Novacor) which had supported him during the previous 15 months. Contrast
transesophageal echocardiography (TEE) revealed an atrial septal defect with
intermittent right-to-left shunt across a patent foramen ovale. We postulate that
the shunt detected in this patient occurred as a consequence of reduced pulmonary
vascular compliance due to positive end-expiratory pressure (PEEP) and an
increase of mean intrathoracic pressure. Furthermore, we hypothesize that
synchronized LVAD operation exacerbates any potential right-to-left shunt due to
the profound left ventricular unloading which occurs during LVAD support. In this
first report of a right-to-left shunt from a previously unrecognized patent
foramen ovale in a Novacor patient, the subsequent transient hypoxemia could be
managed by avoiding PEEP of more than 3 mmHg, and mean airway pressure of more
than 11 mmHg and by careful volume replacement in order to prevent the pump from
completely emptying the left ventricle (LV) and the left atrium (LA). Thus, prior
to every LVAD implantation a transesophageal contrast echocardiography with
Valsalva maneuver should be performed to identify intracardiac right-to-left
shunt.
PMID- 10669283
TI - Efficacy and safety of premedication with oral ketamine for day-case
adenoidectomy compared with rectal diazepam/diclofenac and EMLA.
AB - BACKGROUND: Because of its pain-attenuating and sedative properties oral ketamine
has been used as premedication in children and adults. We wanted to compare in
children scheduled for adenoidectomy safety and efficacy of oral ketamine with a
premedication that causes similar preoperative sedation and relief of pain at the
venepuncture site. We also evaluated the effect of i.v. glycopyrrolate added to
these combinations. METHODS: One hundred children between 10 and 15 kg of body
weight scheduled for day-case adenoidectomy were randomly assigned to one of four
groups: groups DG and DS received diclofenac 12.5 mg and diazepam 0.5 mg/kg
rectally, EMLA cream at the venepuncture site, and placebo orally; groups KG and
KS received ketamine 6.0 mg/kg orally, placebo cream at the puncture site, and
placebo rectally; additionally, groups DG and KG received glycopyrrolate 5
microg/kg, and groups DS and KS received placebo intravenously. We recorded
perioperatively scores (open scale 1-9) for stridor, sedation, bleeding, nausea,
pain, heart rate, the need for analgesics and registered psychotomimesis and well
being at home. RESULTS: The children of the K-groups became more tearful during
separation from their parents (P=0.0072). No other differences were found between
the ketamine and diazepam/diclofenac groups before and after premedication until
induction of anaesthesia. Oral ketamine produced unpleasant psychotomimesis in
four out of 59 children. During the first 10 min postoperatively, the score for
stridor was significantly higher in group KS than in the D-groups; stridor scores
> or = 6 were seen in one child of the D-groups (DS) and in six children of the K
groups (n.s.), of whom three developed laryngospasm (one reintubation).
Glycopyrrolate diminished salivation in all groups, but had no effect on stridor
scores. Additionally, glycopyrrolate delayed the onset of eating at home.
CONCLUSION: Premedication with racemic oral ketamine 6 mg/kg does not seem to be
suitable for upper airway procedures. Addition of i.v. glycopyrrolate before the
induction of anaesthesia significantly reduced the scores for salivation.
PMID- 10669285
TI - Use of solid-phase microextraction for measuring oil-water partition coefficients
and correlation with high-performance liquid chromatographic methods for
lipophilicity.
AB - For flavour compounds, lipophilicity is often estimated by the partition
coefficient between oil and water (log Koil-water), which is highly relevant to
food. A modification of the shake-flask method is reported here where compounds
are quantified in the two phases using solid-phase microextraction (SPME). SPME's
highly sensitivity to non-polar compounds facilitates quantification in the water
phase. Twelve flavour compounds representing a broad range of lipophilicities and
functional groups were analysed by two methods. Their log Koil-water was
determined using SPME quantitation and their log k(w) using a reversed-phase HPLC
methodology. The isocratic capacity factor at 60% methanol and predicted log P
value also showed high correlation factors with other methods. The octadecyl
silylated surface of the HPLC column provides a matrix that interacts with
lipophilic compounds where the retention time is the indication of lipophilicity.
Both methods gave reproducible results (median 3% and 4% RSD) and similar but not
identical values for lipophilicity. The relationship between the two methods is
log k(w) =0.85 log Koil-water +0.48 with a correlation coefficient of 0.94. The
new SPME detection method, with the ability to quantify limonene and 2
pentylfuran at 1 ppm in the water phase, is preferred for flavour compound
analysis due to the applicability of oil-water partitioning in food.
PMID- 10669286
TI - Liquid chromatography-mass spectrometry method for the determination of aldehydes
derivatized by the Hantzsch reaction.
AB - A liquid chromatography-mass spectrometry method for the determination of
aliphatic aldehydes after derivatization with acetylacetone or dimedone by means
of the Hantzsch reaction is presented. Two molecules of a beta-diketone, one
molecule of ammonia and an aliphatic aldehyde cyclisate under formation of
colored and fluorescent reaction products. Atmospheric pressure chemical
ionization (APCI) and electrospray ionization (ESI) in the positive mode are
suitable to ionize the formed dihydropyridine and decahydroacridine derivatives
under protonation of their basic secondary amine functionality. The method has
been used to identify the oxidation product of the formaldehyde derivatives as
side product. The acetaldehyde derivative, presumably formed in the reaction of
residual acetaldehyde in the acetic acid or acetate reagents, is mainly
responsible for the increasing fluorescence background of the reagent solutions.
PMID- 10669287
TI - Molecular mass distribution of sodium alginate by high-performance size-exclusion
chromatography.
AB - A sensitive high-performance size-exclusion chromatography (HPSEC) method with
simple UV detection was developed for the molecular mass analysis of sodium
alginate. It was used to evaluate alginates of varying molecular mass and the
results were compared with the viscosity measurements. This HPSEC method was
sensitive to serve as the stability indicating method for alginate after storage
under different conditions. The information of relative molecular mass
distribution of alginate was provided with reference to pullulan molecular mass
standards. The comparison of the HPSEC chromatograms of alginate, pullulan and
dextran revealed the effect of chemical composition of a polysaccharide and its
effect on apparent molecular mass distribution.
PMID- 10669288
TI - High-performance liquid chromatography method for the characterization of
rhamnolipid mixtures produced by pseudomonas aeruginosa UG2 on corn oil.
AB - A HPLC method was developed to quantify rhamnolipid species in a bacterial
biosurfactant mixture. The biosurfactant mixtures containing mainly 3-[3'-(L
rhamnopyranosyl-oxy)decanoyloxy]decanoic acid (RhC10C10), 3-[3'-(2'-O-alpha-L
rhamnopyranosyl-oxy)decanoyloxy]decanoic acid (Rh2C10C10), 3-[3'-(2'-O-alpha-L
rhamnopyranosyl-oxy)decanoyloxy]dodecanoic acid (Rh2C10C12), and a dehydrogenated
variety of the latter, 3-[3'-(2'-O-alpha-L-rhamnopyranosyl
oxy)decanoyloxy]dodecenoic acid (Rh2C10C12-H2), were isolated from Pseudomonas
aeruginosa UG2 cultures grown on corn oil as sole carbon. The rhamnolipid species
were identified and quantified after their derivatization to the corresponding
phenacyl esters. To confirm the reliability of the HPLC method, the biosurfactant
mixtures and the HPLC isolated species were further analyzed. Mass spectroscopy
(electrospray ionization and atmospheric pressure chemical ionization techniques)
was used to confirm their molecular mass, gas chromatography to verify their
fatty acid content, and a colorimetric assay to quantify the rhamnose content.
PMID- 10669289
TI - Determination of octanol-water partition coefficient for terpenoids using
reversed-phase high-performance liquid chromatography.
AB - Octanol-water partition coefficients (Kow) for 57 terpenoids were measured using
a RP-HPLC method. Sample detection was achieved with standard UV and refractive
index detectors and required no special column treatment. Measured log Kow values
for the terpenoids ranged from 1.81 to 4.48 with a standard error of between 0.03
and 0.08 over the entire range. Partition coefficients determined by the RP-HPLC
method were compared against shake flask, atom/fragment contribution, fragment
and atomistic methods. The HPLC values were found to give the best correlation
with shake flask results. Log Kow values calculated by the atom/fragment
contribution method gave the best correlation with the HPLC values when compared
to fragment and atomistic methods.
PMID- 10669290
TI - Considerations of sample application and elution during size-exclusion
chromatography-based protein refolding.
AB - A mechanism for size-exclusion chromatography-based protein refolding is
described. The model considers the steps of loading the denatured protein onto a
gel filtration column, and protein elution. The model predictions are compared
with results of refolding lysozyme (10 and 20 mg/ml) using Superdex 75 HR. The
main collapse in protein structure occurred immediately after loading, where the
partition coefficient of unfolded lysozyme increased from 0.1 to 0.48 for the
partially folded molecule. Use of a refolding buffer as the mobile phase resulted
in complete refolding of lysozyme; this eluted at an elution volume of 15.6 ml
with a final partition coefficient of 0.54. The model predicted the elution
volume of refolded lysozyme at 19.3 ml.
PMID- 10669291
TI - Eliminating disulfide exchange during glutamyl endopeptidase digestion of native
protein.
AB - Numerous advantages of using immobilized enzymes over free-solution protein
digests have been cited in the literature. This investigation examines both the
rate of hydrolysis and the extent of disulfide bond exchange in disulfide bridged
dipeptide fragments formed during proteolysis of native protein. Glutamyl
endopeptidase as both an immobilized enzyme and in free solution was used in
these studies. It was found that extensive hydrolysis of insulin was achieved in
2 min with immobilized enzyme cartridges operated in the stopped-flow mode
orders. This is orders of magnitude faster than was seen in free solution. Other
advantages ranging from ease of use and reduction in sample size to the potential
for automation were also noted with the immobilized enzyme cartridge. Normal free
solution proteolysis generally requires 12-24 h, based on the lower enzyme-to
substrate ratio in solution. A disturbing feature noted in these lengthy free
solution reactions was the tendency to form disulfide bridged peptide artifacts.
This could lead to the erroneous conclusion that disulfide bonding in a sample
was not that of the native protein. It is concluded that the advantage of
immobilized enzymes over free-solution reactions will be most important in the
pharmaceutical industry where proteolytic fragment "fingerprinting" of
recombinant proteins is being used to confirm structure.
PMID- 10669292
TI - Natural poly-histidine affinity tag for purification of recombinant proteins on
cobalt(II)-carboxymethylaspartate crosslinked agarose.
AB - A natural 19-amino-acid poly-histidine affinity tag was cloned at the N-terminus
of three recombinant proteins. The vectors containing the DNA of the fusion
proteins were used for transformation of Escherichia coli DH5alpha cells. Each
protein was expressed, extracted and purified in one chromatographic step. The
purification procedure for each protein can be accomplished in less than 1 h. A
new type of immobilized metal ion affinity chromatography adsorbent--Co2+
carboxymethylaspartate agarose Superflow--was utilized at linear flow-rates as
high as 5 cm/min. The final preparation of each protein is with purity greater
than 95% as ascertained by sodium dodecyl sulfate-electrophoresis. Recovery for
each purified protein was higher than 77% of the initial loaded amount as judged
by biological activity. The operational capacity of Co2+-carboxymethylaspartate
agarose for each protein was determined.
PMID- 10669293
TI - A reversed-phase high-performance liquid chromatographic method to analyze
retinal isomers.
AB - A high-performance liquid chromatographic (HPLC) procedure was developed to
separate all-trans-, 13-cis-, 11-cis- and 9-cis-retinal isomers. Two reversed
phase Vydac C18 columns in series were used with an isocratic solvent system of
0.1 M ammonium acetate-acetonitrile (40:60, v/v) as mobile phase and all-trans-9
(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-no natetraene-1-ol (TMMP)
as internal standard. Prior to HPLC, the retinal isomers were efficiently
extracted in their original isomeric conformation using dichloromethane-n-hexane
in the presence of formaldehyde. This technique is suitable for the assay of 11
cis- and all-trans-retinal isomers in retina.
PMID- 10669294
TI - Ion chromatography determination of trace level bromate by large volume injection
with conductivity and spectrophotometric detection after post column
derivatisation.
AB - Bromate is a well known by-product produced by the ozonisation of drinking water;
the allowed concentration for human consumption has to be regulated to the low
microg l(-1) range. A direct injection, ion chromatographic method was developed
using a tetraborate eluent with serially connected conductivity and
spectrophotometric detection. Bromate was detected after post-column reaction
with fuchsin at 520 nm. Sample capacity was investigated by injecting large
volumes (up to 6 ml) using a high total hardness and chloride tap water. Linear
correlation of bromate response with volumes from 1 ml to 6 ml was demonstrated,
the main limitation being the overlapping of the chloride peak with bromate. Up
to 1.5 ml sample can be injected without any pre-treatment. With more than 1.5 ml
injection volume, a sample pre-treatment with a cartridge in Ag and H form,
followed by a 10 min degassing in an ultrasonic bath, was needed. This method was
validated by analysing secondary reference materials and real samples from a
drinking water treatment plant. The method was linear from the limit of
quantification to 20 microg l(-1). Reproducibilities in tap water were 18% (5
microg l(-1), n=12) and 21% (1 microg l(-1), n=4) respectively for 1.5 and 6 ml
injection volumes with conductivity detection, and 17% at 0.5 microg l(-1) (n=9)
with spectrophotometric detection. Calculated detection limits were 0.5 microg l(
1) (6 ml) ahd 2 microg l(-1) (1.5 ml) for conductivity detection and 0.3 microg
l(-1) (1.5 ml) for spectrophotometric detection.
PMID- 10669295
TI - Chiral high-performance liquid chromatography of N-octyl bicycloheptene
dicarboximide and confirmatory studies using liquid chromatography-tandem mass
spectrometry and two-dimensional nuclear magnetic resonance spectroscopy.
AB - N-Octyl bicycloheptene dicarboximide (MGK 264) has exo and endo diastereomers.
Each structure has a chiral center at the nitrogen side chain. Enantioselective
separation of MGK 264 was achieved by normal-phase high-performance liquid
chromatography (HPLC) using cellulose-based Chiralcel OD column with diode-array
and optical rotation detectors. Peaks were isolated with the purpose of
identifying their stereochemical structures. Molecular mass of the HPLC peaks and
their structural information was determined by liquid chromatography-electrospray
tandem mass spectrometry (LC-ES-MS-MS). A two-dimensional nuclear magnetic
resonance (NMR) spectroscopic technique was used to establish the structural
features. Correlation of the data obtained from chiral separation and NMR
facilitated in unambiguous assignment of the HPLC peaks.
PMID- 10669296
TI - Characterisation of hydrolysable tannins from leaves of Betula pubescens by high
performance liquid chromatography-mass spectrometry.
AB - A high-performance liquid chromatography-electrospray ionisation mass
spectrometry (HPLC-ESI-MS) method, assisted by diode array detection, for the
characterisation of individual hydrolysable tannins in birch leaves was
developed. With the method, it was found that birch (Betula pubescens) leaves
contained an exceptionally complex mixture of hydrolysable tannins; 14
gallotannins and 20 ellagitannins were identified. The developed HPLC-ESI-MS
method allows the qualitative and quantitative determination of individual
gallotannins and ellagitannins directly from crude birch leaf extract. This is
important in studying ecological functions of these phenolic compounds,
especially their role in the resistance of birch leaves against insects.
PMID- 10669297
TI - Heats of adsorption of some organic compounds on beta-cyclodextrin determined by
gas-solid chromatography.
AB - Isosteric adsorptive enthalpies have been derived from the temperature dependence
of retention volumes determined by eluted pulse gas-solid chromatography. The
heat data were obtained for systems using more than 20 organic liquids as
adsorbates, and beta-cyclodextrin as adsorbent. The experimental results have
been discussed in the light of intermolecular force between molecules of
adsorbate and adsorbent.
PMID- 10669298
TI - Application of gas chromatography-cryocondensation-Fourier transform infrared
spectroscopy and gas chromatography-mass spectrometry to the identification of
gas phase reaction products from the alpha-pinene/ozone reaction.
AB - The gas phase reaction of alpha-pinene with the atmospheric oxidant ozone was
investigated by using the capabilities of both gas chromatography
cryocondensation-Fourier transform infrared spectroscopy (GC-FT-IR) and gas
chromatography-mass spectrometry (GC-MS), for the identification of the reaction
products formed. The reaction was carried out in a flow reaction chamber from
where the compounds were sampled on Tenax-containing adsorption cartridges. The
reaction mixture was injected onto the column after thermodesorption and analyzed
using both GC-IR and GC-MS. Twenty compounds could be detected, including the
reactant alpha-pinene and it's impurities tricyclene and camphene. Eleven
compounds were identified by spectra comparison with either reference data or
spectra obtained from commercial standards. Four compounds were tentatively
identified from their IR and MS spectra, while from the remaining two compounds
the nature of basic functional groups could be established.
PMID- 10669299
TI - Simultaneous determination of phenolic acids and 2,4-dihydroxy-7-methoxy-1,4
benzoxazin-3-one in wheat (Triticum aestivum L.) by gas chromatography-tandem
mass spectrometry.
AB - A procedure using gas chromatography and tandem mass spectrometry (GC-MS-MS) has
been developed for the identification and quantification of some allelochemicals
in wheat (Triticum aestivum L.). The quantities of allelochemicals in wheat
shoots ranged from 2.9 to 110 mg per kilogram of dry shoot residues. Compared
with gas chromatography-mass spectrometry (GC-MS), the GC-MS-MS technique
significantly increased instrument selectivity and sensitivity, thereby providing
more reliable quantitation results in the determination of the phytotoxic
compounds examined during this allelopathy research.
PMID- 10669300
TI - Nonaqueous capillary electrophoresis equipped with amperometric detection for
analysis of chlorinated phenolic compounds.
AB - Nonaqueous capillary electrophoresis (NACE) equipped with amperometric detection
has been developed for separation and detection of an 11-member model mixture of
chlorinated phenolic compounds. With triacetyl-beta-cyclodextrin (TACD) as a
novel selectivity selector, acetonitrile proved to be an excellent solvent for
this water-insoluble cyclodextrin derivative. Resolution of the analytes was
achieved by using an optimized acetonitrile medium consisting of 500 mM acetic
acid, 10 mM sodium acetate, 12 mM TACD and 50 mM tetrabutylammonium perchlorate.
Separation of analytes was attributed to differential electrostatic and/or
inductive interactions of the analytes with the TACD/TBA+ complex and charged
tetrabutylammonium phases. A simple end-column amperometric detector (Pt vs.
Ag/AgCl, poised at +1.6 V) in conjunction with NACE was used to analyze
chlorophenols. Amperometric detection of such target compounds in acetonitrile
based media offers high sensitivity and alleviates electrode fouling compared to
aqueous buffers. The detection limits obtained, ranging from 30 nM to 500 nM, are
3-8-fold lower than those obtained with aqueous buffers.
PMID- 10669301
TI - Capillary zone electrophoretic analysis of positively charged poly(ethylene
oxide) macromolecules using non-covalent polycation-coated fused-silica capillary
and indirect UV detection.
AB - Capillary zone electrophoresis was used to show the coupling between NH2
terminated poly(ethylene oxide) and oligomers of lactic acid activated by
transforming carboxyl chain ends to acyl chloride ones. The demonstration was
based on the use of fused-silica capillary physically modified by pre-adsorption
of polycations in the reversed polarity mode. As poly(ethylene oxide)
macromolecules are UV transparent, indirect UV detection was used. A creatinine
solution at pH 4.8 was selected as background electrolyte. Commercially available
polycations with different structures were tested. It was shown that the reversed
electroosmosis could be modulated according to the structure of the polycation.
The method was then applied to analyse a commercial alpha,omega-diamino
poly(ethylene oxide), namely Jeffamine ED 600 characterised by a broad mass
dispersion. Data showed that the method can detect and separate amino
poly(ethylene oxide) of different structures. When applied to analyse post
coupling products, no free NH2-terminated poly(ethylene oxide) segments were
detected. Moreover, the method allowed detection of water-soluble oligomers
generated by partial degradation of lactic segments during the reaction.
PMID- 10669302
TI - On the performance and inertness of different materials used for the enrichment
of sulfur compounds from air and gaseous samples.
AB - The performance of the sorbent polydimethylsiloxane (PDMS) is compared to that of
the adsorbents Carbotrap and Tenax for the enrichment of volatile and reactive
sulfur compounds. These included: 1- and 2-propanethiol, tetrahydrothiophene, 2
thioethanol and 2-ethylthioethanol. Several artifact-forming reactions were
identified on both Tenax and Carbotrap including: H2S elimination and
dimerization of thiols. Additionally, permanent adsorption was also observed for
heavier solutes. These effects are absent when PDMS is applied. This superior
performance is explained by the absence of catalytic or adsorptive activity on
PDMS.
PMID- 10669303
TI - New gas chromatographic method for residue determination of dithiopyr in soil,
wheat grain and straw.
AB - A gas chromatographic method has been developed for a new pyridine herbicide,
dithiopyr, utilising an electron capture detector. The method makes use of a
column (10 m x 0.534 mm I.D.; 1 microm film thickness) containing HP-1 with
nitrogen as a carrier gas at a flow rate of 15 ml min(-1) at temperatures of 190,
210, 270 degrees C for oven, injector port and detector, respectively. Soil,
wheat grain and straw samples fortified with dithiopyr were extracted with
acetone-0.2 M HCl (95:5) and cleaned up by partitioning with hexane. The
technique has a sensitivity of 0.05 microg ml(-1) and the recovery of dithiopyr
from soil, wheat grain and straw ranged between 80 and 99%.
PMID- 10669304
TI - Lipid chain dynamics in stratum corneum studied by spin label electron
paramagnetic resonance.
AB - The lipid chain motions in stratum corneum (SC) membranes have been studied
through electron paramagnetic resonance (EPR) spectroscopy of stearic acid spin
labeled at the 5th, 12th and 16th carbon atom positions of the acyl chain. Lipids
have been extracted from SC with a series of chloroform/methanol mixtures, in
order to compare the molecular dynamics and the thermotropic behavior in intact
SC, lipid-depleted SC (containing covalently bound lipids of the corneocyte
envelope) and dispersion of extracted SC lipids. The segmental motion of 5- and
12-doxylstearic acid (5- and 12-DSA) and the rotational correlation time of 16
doxylstearic acid (16-DSA) showed that the envelope lipids are more rigid and the
extracted lipids are more fluid than the lipids of the intact SC over the range
of temperature measured. The lower fluidity observed for the corneocyte envelope,
that may be caused mainly due to lipid-protein interactions, suggests a major
contribution of this lipid domain to the barrier function of SC. Changes in the
activation energy for reorientational diffusion of the 16-DSA spin label showed
apparent phase transitions around 54 degrees C, for the three SC samples. Some
lipid reorganization may occur in SC above 54 degrees C, in agreement with
results reported from studies with several other techniques. This reorganization
is sensitive to the presence of the extractable intercellular lipids, being
different in the lipid-depleted sample as compared to native SC and lipid
dispersion. The results contribute to the understanding of alkyl chain packing
and mobility in the SC membranes, which are involved in the mechanisms that
control the permeability of different compounds through skin, suggesting an
important involvement of the envelope in the skin barrier.
PMID- 10669305
TI - Detection of lipid domains in docasahexaenoic acid-rich bilayers by acyl chain
specific FRET probes.
AB - A major problem in defining biological membrane structure is deducing the nature
and even existence of lipid microdomains. Lipid microdomains have been defined
operationally as heterogeneities in the behavior of fluorescent membrane probes,
particularly the fluorescence resonance energy transfer (FRET) probes 7-nitrobenz
2-oxa-1,3-diazol-4-yl-diacyl-sn-glycero-3-phosphoethan olamine (N-NBD-PE) and (N
lissamine rhodamine B sulfonyl)-diacyl-snglycero-3-phosphoethanolamine (N-Rh-PE).
Here we test a variety of N-NBD-PEs and N-Rh-PEs containing: (a) undefined acyl
chains, (b) liquid crystalline- and gel-state acyl chains, and (c) defined acyl
chains matching those of phase separated membrane lipids. The phospholipid
bilayer systems employed represent a liquid crystalline/gel phase separation and
a cholesterol-driven fluid/fluid phase separation; phase separation is confirmed
by differential scanning calorimetry. We tested the hypothesis that acyl chain
affinities may dictate the phase into which N-NBD-PE and N-Rh-PE FRET probes
partition. While these FRET probes were largely successful at tracking liquid
crystalline/gel phase separations, they were less useful in following fluid/fluid
separations and appeared to preferentially partition into the liquid-disordered
phase. Additionally, partition measurements indicate that the rhodamine
containing probes are substantially less hydrophobic than the analogous NBD
probes. These experiments indicate that acyl chain affinities may not be
sufficient to employ acyl chain-specific N-NBD-PE/N-Rh-PE FRET probes to
investigate phase separations into biologically relevant fluid/fluid lipid
microdomains.
PMID- 10669306
TI - Chemical degradation of liposomes by serum components detected by NMR.
AB - Interaction between serum components and liposomes is an oxygen-dependent
exothermic process. We studied the interaction of 100 nm extruded liposomes
(bearing positive, negative or no charge) with foetal calf serum by 1H NMR and
13C NMR, in order to further our understanding of these reactions. Studies of
aqueous or organic extracts obtained after 2 h, 1 day or 1 week, showed
hydrolysis to be a degradation process concomitant with the interaction with
serum. Oxidation was identified as additional to hydrolysis in the process of
degradation. Oxidation produced aldehydes, acids and alcohols, although aldehydes
and alcohols were prone to further decomposition and only appeared transiently.
Alkenes and other oxidized compounds predominated in those products derived from
oxidation. In stearylamine-containing liposomes some aldehydes and a
nitroderivative were found as degradation products. Such metabolites are apolar
and their presence might explain the intrinsic toxicity of this kind of liposome
in cell cultures. The work described in the present study revealed the chemical
degradation of liposomes in the serum used. In all cases the results obtained
were compared with liposomes not incubated with serum.
PMID- 10669307
TI - Interaction of hyaluronic acid-linked phosphatidylethanolamine (HyPE) with LDL
and its effect on the susceptibility of LDL lipids to oxidation.
AB - The amphiphilic polysaccharide hyaluronic acid-linked phosphatidylethanolamine
(HyPE), synthesized by covalently binding dipalmitoyl-phosphatidylethanolamine
(DPPE) to short chain hyaluronic acid (mol. wt. approximately = 30 000),
interacts with low-density lipoproteins (LDL), to form a 'sugar-decoration' of
the LDL surface. This results in an increase in the apparent size of the LDL
particles, as studied by photon correlation spectroscopy, and in broadening of
the 1H NMR signals of the LDL's phospholipids. Experiments conducted with
fluorescently-labeled HyPE indicate that the interaction of HyPE with LDL
involves incorporation of the hydrocarbon chains of this amphiphilic
polysaccharide into the outer monolayer of the LDL. This interaction also
inhibits the copper-induced oxidation of the LDL polyunsaturated fatty acids,
avoiding oxidation altogether when the concentration of HyPE is higher than a
tenth of the concentration of the LDL's phospholipids. This can not be attributed
to competitive binding of copper by HyPE. We propose that the protection of LDL
lipids against copper-induced oxidation is due to formation of a sugar network
around the LDL.
PMID- 10669308
TI - Apolipoprotein A-I localization and dipalmitoylphosphatidylcholine dynamics in
reconstituted high density lipoproteins.
AB - The structure and molecular dynamics of recombinant high density lipoproteins
(rHDL) were studied by non-radiative energy transfer (NRET), fluorescence
anisotropy and intensity measurements. The rHDL particles contained human plasma
apolipoprotein (apo) A-I and dipalmitoylphosphatidylcholine (DPPC). Fluorescent
cis- and trans-parinaric acids were used both as probes of molecular motion in
the particle lipid phase and as acceptors in the Forster's energy transfer from
apo A-I tryptophan residues to determine particle dimensions, apolipoprotein
localization and lipid dynamics. The probes are sensitive to thermal wobbling
(macromobility) and conformational deformations (micromobility) of phospholipid
acyl chains. The experimental data fitted to various models of the particle
structure are compatible with the following: (a) at T < Tt the particles appeared
as lens-like discs with a radius of the lipid phase of 5 nm and a mean thickness
of 4 nm, the value being more by 20% in the particle centre, the alpha-helices of
about 1 nm thickness were located around the edge of the lipid core. Compared to
liposomes, both macro- and micromobility of DPPC molecules in rHDL were more
rapid due to a significant disorder of the boundary lipid molecules close to the
apo A-I molecule. This disorder led to the increase of the specific surface area
per one lipid molecule, S(o). The lipid phase can be divided into three regions:
(i) zone I of the most tightly packed lipid (0-1.7 nm from the disc axis) with a
S(o) value small as 0.5 nm2; (ii) intermediate zone II (from 1.7 to 4.0 nm); and
(iii) boundary lipid zone III (4-5 nm) of significantly disordered lipid with a
S(o) value large as 0.65 nm2. (b) at T> Tt the S(o) heterogeneity disappeared,
the radius of the lipid phase did not increase significantly, not exceeding 5.2
5.4 nm, but protein-induced immobilization of lipid molecules which affected
about half or more of the total lipid, became remarkable. The overall effect was
the suppression of the transition amplitude in rHDL compared to liposomes. The
structural inhomogeneity might underlie the function of the native plasma HDL as
the key component of the transport and metabolism of plasma lipids.
PMID- 10669309
TI - Two-enzyme system for the synthesis for 1-lauroyl-rac-glycerophosphate
(lysophosphatidic acid) and 1-lauroyl-dihydroxyacetonephosphate.
AB - A combination of two enzymes, phospholipase D (PL D) and C (PL C), was
investigated for the production of two lysophospholipids, 1-lauroyl-rac
glycerophosphate (1-LGP) and 1-lauroyl-dihydroxyacetonephosphate (1-LDHAP). The
high transphosphatidylation ability of phospholipase D from Streptomyces sp.
allowed the formation of 1-lauroyl-phosphatidylglycerol (1-LPG) and 1-lauroyl
phosphatidyldihydroxyacetone (1-LPDHA) from phosphatidylcholine (PC) and 1
monolauroyl-rac-glycerol (1-MLG) and 1-lauroyl-dihydroxyacetone (1-MDHA),
respectively. A two-phase system, diethyl ether/water, was chosen for the
convenience of the recovery of the water insoluble products. A similar two-phase
system was used for hydrolysis of the complex phospholipids by phospholipase C
form Bacillus cereus, which released both lysophospholipids. Only trace amounts
of phosphatidic acid (PA) were detected showing that the enzyme is highly
selective for the release of the diacylglycerol and 1-lauroyl-rac
glycerophosphate and 1-lauroyl-dihydroxyacetonephosphate.
PMID- 10669310
TI - A sensitive endocannabinoid assay. The simultaneous analysis of N
acylethanolamines and 2-monoacylglycerols.
AB - Mammalian cells produce both N-arachidonoylethanolamine (20:4n-6 NAE, anandamide)
and 2-arachidonoylglycerol (2-AG), lipid signaling molecules that activate
cannabinoid receptors. Because both agonists occur in the presence of receptor
inactive congeners, we have developed a sensitive method for the simultaneous
assay of N-acylethanolamines (NAEs) and 2-monoacylglycerols (2-MAG). These lipid
classes are isolated from total lipids by solid phase extraction and converted to
tert-butyldimethylsilyl (tBDMS) derivatives in the presence of deuterated
analogs. The tBDMS derivatives are analyzed by gas chromatography/mass
spectrometry using selected ion monitoring programs specific for NAE and 2-MAG.
Individual NAEs and 2-MAGs can be quantified in the nanogram and subnanogram
range. The NAE and 2-MAG compositions of rat organs and cultured JB6 cells are
reported.
PMID- 10669311
TI - Cholesterol-induced alterations of the packing properties of gangliosides: an EPR
study.
AB - The effect of cholesterol (Chol) on two kinds of glycolipid assemblies, one
composed of monosialogangliosides (GM1a) and the other formed by a natural
mixture of bovine brain gangliosides (TBG), has been analysed. The experimental
approach involves spin label electron paramagnetic resonance (EPR) in aqueous
lipid dispersions. The employment of a hydrosoluble spin label and a 'quencher'
of the EPR signal that is not able to permeate lipid interfaces, allowed us to
conclude that GM1a/Chol mixtures give rise to vesicles at Chol proportions for
which TBG/Chol mixtures form micelles. The use of different liposoluble spin
labels reveals that cholesterol produces a straightening of the hydrocarbon
chains in both lipid systems. In GM1a/Chol mixtures, this feature is more
pronounced and it is coupled with a decrease in polarity at the chain ends.
PMID- 10669312
TI - The structure and function of gramicidin A embedded in interdigitated bilayer.
AB - The effects of phase transition from normal to interdigitated lipid bilayer on
the function and structure of membrane proteins were studied using linear
gramicidin (gramicidin A) as a model. Interdigitated bilayer structure of
dipalmitoylphosphatidylglycerol (DPPG) liposomes that was induced by atropine
could not be changed notably by intercalating of gramicidin. The K+
transportation of gramicidin in both normal and interdigitated bilayer was
assayed by measuring the membrane potential. Results showed that gramicidin in
interdigitated bilayer exhibited lower transport capability. Intrinsic
fluorescence spectrum of gramicidin in interdigitated bilayer blue-shifted 2.8 nm
from the spectrum in normal bilayer, which means that interdigitation provides a
more hydrophobic environment for gramicidin. Circular dichroism measurement
results indicated that the conformation of gramicidin in interdigitated bilayer
is not the typical beta6.3 helix as in the normal bilayer. The results suggested
that the interdigitated lipid bilayer might largely affect the structure and
function of membrane proteins.
PMID- 10669313
TI - Thermal destabilization of transmembrane proteins by local anaesthetics.
AB - Local anaesthetics, in addition to anaesthesia, induce the synthesis of heat
shock proteins (HSPs), sensitize cells to hyperthermia, and increase the
aggregation of nuclear proteins during heat shock. Anaesthetics are membrane
active agents, and anaesthesia appears to be due to altered ion channel activity;
however, the direct effect of heat shock is protein denaturation. These
observations suggest that local anaesthetics may sensitize cells to hyperthermia
by interacting with and destabilizing membrane proteins such that protein
denaturation is increased. It is shown, using differential scanning calorimetry
(DSC), that the local anaesthetics procaine, lidocaine, tetracaine and dibucaine
destabilize the transmembrane domains of the Ca2+ -ATPase of sarcoplasmic
reticulum and the band III anion transporter of red blood cells. The
transmembrane domain of the Ca2+ -ATPase has a transition temperature (Tm) of
denaturation of 61 degrees C which is decreased, for example, to 53 degrees C by
15 mM lidocaine. The degree of destabilization (deltaTm) by each anaesthetic is
proportional to the lipid to water partition coefficient, and the increased
sensitization by anaesthetics with larger partition coefficients and at higher pH
suggests that the uncharged forms of the anaesthetics are responsible for
destabilization. A Hill analysis of deltaTm for the Ca2+ -ATPase as a function of
the concentration of anaesthetic in water gives dissociation constants (Kd) on
the order of 10(-4) M, if binding occurs directly from the aqueous phase. This
demonstrates moderate affinity binding. However, dissociation constants of 1-3 M
are obtained, if binding occurs through the lipid phase, which demonstrates low
affinity binding. Thus, the interaction of local anaesthetics with the Ca2+
ATPase may be moderately specific or non-specific depending on the mechanism of
interaction. The observation that local anaesthetics also destabilize the
transmembrane domain of the band III protein of erythrocytes suggests that
destabilization of transmembrane proteins is a general property of anaesthetics,
which is at least in part a mechanism of sensitization to hyperthermia.
PMID- 10669314
TI - Apoptosis induced by hyperthermia in Dunn osteosarcoma cell line in vitro.
AB - The effect of hyperthermia at 43.5 degrees C for 1 h on Dunn osteosarcoma cells
was studied. With sham-heated cells (37 degrees C, 1 h) as the control, the
hyperthermia treated cells were divided into five groups. Time 0 group was the
cells that were harvested immediately after heated at 43.5 degrees C for 1 h.
Whereas time 3, 6, 12, and 24 h groups were the cells that were collected
respectively after reincubation at 37 degrees C for the above different time
periods. The appearance of hyperthermia-induced apoptosis of Dunn osteosarcoma
cells was demonstrated to be time dependent. With the confocal microscopic study
and TUNEL staining, the morphological characteristics of apoptosis, condensed
nuclei and fragmented nuclei were obvious when reincubated at 37 degrees C for 6
h after hyperthermic treatment. This hyperthermia-induced apoptosis was further
confirmed by flow cytometric analysis on DNA contents. The sub-G1 region that was
proposed as a marker of apoptotic cells was most significantly elevated at 6 h
after hyperthermic treatment and, thereafter, decreased to the levels of control
values by 24 h, as the apoptotic cells underwent secondary necrosis and degraded
to debris. The DNA strand breaks, considered as the key biochemical event of
apoptosis, were detected by the TUNEL assay. This study indicated that
hyperthermia (43.5 degrees C for 1 h) can induce apoptotic changes on
osteosarcoma cells in vitro very rapidly (within 6 h after treatment), and its
occurrence might not be detected if the samples are not taken at several early
time points after hyperthermia.
PMID- 10669315
TI - Comparison of the effects of two different whole body hyperthermia protocols on
the distribution of murine leukocyte populations.
AB - Two predominant WBH protocols presently being used in clinical trials include a
low temperature, long duration (LL) WBH, where core body temperature is raised to
39.5-40 degrees C for 6h or more, and a high temperature, short duration (HS)
WBH, where core body temperature is raised to 41.8 degrees C for up to 2h. Here,
the effects of LL-WBH and HS-WBH on leukocyte populations in the blood, spleen,
lymph node (LN) and peritoneal cavity (PerC) of Balb/c mice were compared using
flow cytometry. The total numbers of peripheral blood leukocytes decreased up to
2-fold immediately after LL-WBH, reflecting a decrease of lymphocyte numbers
compared to controls. In contrast, the numbers of blood leukocytes are increased
2.7-fold immediately after HS-WBH compared to controls, reflecting an increase in
lymphocytes, monocytes and granulocytes. After both LL- and HS-WBH treatment,
leukocyte numbers in the spleen are decreased approximately 2-fold, again
reflecting decreases in lymphocyte numbers. In the PerC, total numbers of
leukocytes are also significantly decreased (2-fold) during LL-WBH but not HS
WBH. Total numbers of leukocytes in the LNs were unaffected by both LL- and HS
WBH. Overall, these data reveal differential effects of the LL- and HS-WBH
protocols on leukocyte populations in the blood, spleen, LN and PerC of Balb/c
mice.
PMID- 10669316
TI - Fever-range hyperthermia stimulates alpha4beta7 integrin-dependent lymphocyte
endothelial adhesion.
AB - Migration of blood-borne lymphocytes into lymphoid tissues is initiated by the L
selectin and alpha4beta7 integrin adhesion molecules. Previous studies have shown
that L-selectin adhesion is dynamically regulated by febrile temperatures. It is
now reported that fever-range hyperthermia also acts directly on lymphocytes to
enhance selected adhesive functions of alpha4beta7 integrin. Fever-range
hyperthermia treatment in vitro (40 degrees C, 12 h) of murine TK1 lymphoma cells
and human peripheral blood lymphocytes (PBL) stimulates alpha4beta7 integrin
dependent adhesion to high endothelial venules (HEV) in Peyer's patch and
mesenteric lymph node frozen sections. TK1 cells are alpha4beta7hi L
selectin(lo), allowing for the analysis of alpha4beta7 integrin without
contributions from L-selectin. Adhesion was further shown to involve alpha4beta7
integrin and its endothelial counter-receptor, mucosal addressin cell adhesion
molecule-1 (MAdCAM-1) using function-blocking antibodies (i.e. DATK32, HP2/1,
MECA-367). Fever-range hyperthermia also promotes alpha4beta7 integrin-mediated
aggregation of TK1 cells. In sharp contrast, hyperthermia fails to increase
alpha4beta7 integrin adhesion to fibronectin by TK1 cells. Expression of the
alpha4beta7 heterodimer on TK1 cells or human PBL is not altered by hyperthermia,
suggesting that hyperthermia stimulates adhesion by enhancing alpha4beta7
integrin avidity rather than its cell surface density. These results provide a
mechanism whereby febrile temperatures during infection or clinical hyperthermia
potentially amplify the immune response by stimulating L-selectin and alpha4beta7
integrin-dependent homing of immune effector cells to lymphoid tissues.
PMID- 10669318
TI - Acute histological effects of interstitial hyperthermia on normal rat brain.
AB - Histological changes in the brains of Fischer rats at different times after
interstitial heating with various thermal doses were studied. The brains,
subjected to sham-heating, and heating at 39 and 40 degrees C for 30 min showed
mild capillary congestion and minimal vacuolation at 4, 24 and 72 h. In the
brains heated to 41, 42 and 43 degrees C for 30 min, there was local vascular
congestion, petechiae, vacuolation and cellular shrinkage with nuclear pyknosis
at 4 h; enhanced congestion and petechiae, acute cellular necrosis, infiltration
of polymorphonuclear leukocytes and marked vacuolation at the margin at 24h;
total coagulative necrosis of all parenchymal and vascular elements, early
liquefaction necrosis and vascular hyperplasia at the margin at 72 h; enhanced
vascular hyperplasia at the margin at 120 h and 168 h. The threshold thermal dose
for the histopathological damage in the rat brain was heating at 41 degrees C for
30 min.
PMID- 10669317
TI - Hyperthermia and paclitaxel--epirubicin chemotherapy: enhanced cytotoxic effect
in a murine mammary adenocarcinoma.
AB - Multimodality therapy is considered of great interest in the treatment of locally
advanced solid tumours. In previous experiments, paclitaxel (TX) and epirubicin
(EP) were combined with different schedules, obtaining a superadditive effect on
the growth of a murine mammary carcinoma. In the present study, the authors have
analysed the possible use of hyperthermia (HT) to increase the efficacy of TX and
EP combinations. Tumours were transplanted into the right hind foot of female
hybrid (C3D2F1) mice. Both TX and EP were administered i.p in two different
doses. Hyperthermia was applied using a water bath at 43.2 degrees C for 1 h.
Results were analysed in terms of Tumour Growth Delay (TGD). The maximum
tolerated doses in combined protocols were TX 45 mg/kg and EP 9 mg/kg, with an
interval time of 24h between the two administrations. TGDs of some of the
schedules performed are reported: EP + HT = 11 days, TX + HT = 16 days, TX + EP
(with an interval time of 24 h) = 14 days, and TX + EP + HT = 22 days. In the
experimental model, HT significantly increases the effects of both TX and EP. TX
+ EP + HT treatment is the most effective (significantly different from TX + EP),
but not in a significant way when compared to TX + HT treatment. These results
suggest the possible use of a TX + HT protocol for local tumour response, whereas
EP could be added in order to achieve a better systemic control.
PMID- 10669319
TI - Hyperthermia and radiotherapy for inoperable squamous cell carcinoma metastatic
to cervical lymph nodes from an unknown primary site.
AB - INTRODUCTION: Neck node metastases from an unknown primary carcinoma represent an
infrequent but challenging problem for oncologists. The management of such
patients is controversial, but radiotherapy alone or as part of a multimodal
approach is often indicated. Patients with inoperable lesions usually receive
radiotherapy alone at palliative doses. In an attempt to increase local control
in patients with locally advanced neck disease from an unknown primary carcinoma,
local hyperthermia was combined with definitive radiotherapy. MATERIAL AND
METHODS: Between 1982 and 1993, radiotherapy and local microwave hyperthermia
were used to treat 15 patients with metastatic neck nodes from an unknown primary
site. The patients had previously undergone only biopsy or fine needle biopsy,
and showed no signs of metastases beyond the clavicle. Radiation to the nodes and
the potentially primary sites in the head and neck was delivered by a 6 MV linear
accelerator or a Cobalt 60 unit, to a total dose of 57.50-74.40 Gy (median 70
Gy). Hyperthermia was added using a BSD 1000 unit at an operating frequency of
280-300 MHz for 2-7 sessions (mean 3.1; median 2) at a desired minimum
temperature of 42.5 degrees C. Two patients also received i.v. cisplatin 20
mg/m2/week as a radiosensitizer. RESULTS: Nine patients achieved a complete, and
four a partial response for an overall response rate of 86.5%. Acute and late
toxicity was mild: four patients experienced pain during hyperthermia, two moist
cutaneous desquamation, and one cutaneous necrosis. The actuarial probability of
maintaining local control at 5 years is 64.5% and the actuarial overall survival
29%. Five patients developed distant metastases and died of disease, two
experienced nodal recurrence and two died of other unrelated causes. CONCLUSION:
The addition of local microwave hyperthermia to radiotherapy in the treatment of
metastatic squamous cell carcinoma of the neck in patients with an unknown
primary site leads to good local control with moderate toxicity. No definite
conclusions are possible because of the small number of patients involved in this
phase II trial.
PMID- 10669320
TI - Elimination of new chronic hepatitis B virus infections: results of the Alaska
immunization program.
AB - An immunization assessment and a serologic survey were conducted to evaluate the
effectiveness of a hepatitis B immunization program in eliminating hepatitis B
virus (HBV) transmission among Alaska Natives in a region in which HBV infection
is endemic. Hepatitis B vaccine coverage was 93% among 567 children =10 years
old residing in the study villages, and catch-up vaccine coverage among 582
susceptible persons 11-30 years old was 62%. None of 271 tested children =10
years old were chronically infected with HBV, and just 4 (1.5%) had evidence of
resolved infection. In contrast, 16% of 332 persons 11-30 years old (those born
before implementation of routine infant hepatitis B vaccination) were chronically
infected. A hepatitis B immunization program that includes prevention of
perinatal HBV infection, routine infant vaccination, and catch-up vaccination of
older children and adults can eliminate new chronic HBV infections in a
population with a high rate of chronic infection.
PMID- 10669321
TI - Persistence rate and progression of vertically acquired hepatitis C infection.
European Paediatric Hepatitis C Virus Infection.
AB - Data were collected from 104 infected children who were followed up from birth
for a mean of 49 (range, 6-153) months in 22 European centers, to outline the
natural history of perinatal hepatitis C virus (HCV) infection. Fifty-four
children were persistently HCV RNA positive, 44 were occasionally positive, and 6
never had detectable viremia. At least 90% of the children had evidence of
ongoing infection at the latest analysis. Eighteen children became HCV RNA
negative at their last assessments, but 40% of these had high alanine
aminotransferase (ALT) concentrations. Infection was asymptomatic in all but 2
children, who developed hepatomegaly. Mean ALT concentrations decreased
substantially after the first 2 years of life; 14 children had persistently
normal ALT values. Signs of minimal to moderate inflammation were noted in all 20
patients who underwent liver biopsy. Perinatal HCV infection is usually
asymptomatic in the first years of life, but the virus persists in most children,
even in the absence of elevated ALT activity.
PMID- 10669322
TI - Serum level of soluble intercellular adhesion molecule 1 in patients with chronic
liver disease related to hepatitis C virus: A prognostic marker for responses to
interferon treatment.
AB - Intercellular adhesion molecule 1 (ICAM-1) is a marker of inflammation and tissue
damage. Levels of soluble ICAM-1 (sICAM-1) were measured in 71 patients with
chronic C hepatitis treated with interferon (IFN)-alpha-2a, at baseline and at
every 3 months of therapy, and in 42 normal control subjects. The levels of sICAM
1 were significantly higher in the patient than in the control subject group,
particularly among cirrhotics. Baseline sICAM-1 levels were similar in responders
and nonresponders. By contrast, the concentration of sICAM-1 decreased
significantly only in responders during the first 3 months of therapy. The
probability of response to treatment, analyzed by Kaplan-Meier analysis, was much
higher in the group showing a decrease of sICAM-1 than in the patients who did
not show such a decrease. In conclusion, a "longitudinal" evaluation of serum
levels of sICAM-1 in the first period of treatment is particularly useful in the
identification of patients with high significant probability of response to
treatment.
PMID- 10669323
TI - Mutations in the protein kinase-binding domain of the NS5A protein in patients
infected with hepatitis C virus type 1a are associated with treatment response.
AB - An interaction of the hepatitis C virus (HCV) NS5A protein with the interferon
(IFN)-alpha-inducible double-stranded RNA-activated protein kinase (PKR) was
demonstrated in vitro. The clinical correlation between amino acid mutations
within the HCV NS5A region and response to antiviral treatment is controversial.
Thirty-two patients chronically infected with HCV-1a, who were treated with IFN
alpha with or without ribavirin, were studied. The carboxy-terminal half of HCV
NS5A was sequenced and was investigated by phylogenetic and conformational
analyses. Eight patients achieved a sustained virologic response. An end-of
treatment response but relapse thereafter was observed among 8 patients, whereas
16 patients were nonresponders. The median number of mutations within the PKR
binding domain but not within the previously described IFN sensitivity
determining region was significantly higher for patients with sustained (3
mutations [range, 1-5]) or end-of-treatment (4 mutations [range, 1-5]) virologic
response than for nonresponders (2 mutations [range, 0-3]) (P=.0087).
Phylogenetic and conformational analyses of NS5A sequences allowed no
differentiation between sensitive and resistant strains.
PMID- 10669324
TI - Hepatitis C virus in lymphoid cells of patients coinfected with human
immunodeficiency virus type 1: evidence of active replication in
monocytes/macrophages and lymphocytes.
AB - It has been reported that hepatitis C virus (HCV) may be lymphotropic in the
setting of human immunodeficiency virus type 1 (HIV-1) coinfection. The present
study was undertaken to determine the phenotype of lymphoid cells harboring
replicating HCV in HIV-1-positive subjects. By means of highly strand-specific
thermostable enzyme Tth-based reverse-transcriptase polymerase chain reaction,
the presence of viral RNA-negative strand was sought in different subpopulations
of peripheral blood mononuclear cells from 10 HIV-positive patients. HCV RNA
negative strand was most commonly present in monocytes/macrophages (4 cases),
followed by CD8+ and CD4+ lymphocytes (2 cases) and CD19+ cells (1 case). In 2
cases that were further analyzed, viral-negative strand remained detectable in
monocytes/macrophages cultured for 3 weeks. Moreover, monocyte/macrophage- and
serum-derived viral sequences differed in the 5' untranslated region. These
findings imply that, in HIV-infected subjects, HCV may replicate in the same
cells as HIV-1, which raises the possibility of direct interactions between these
pathogens.
PMID- 10669325
TI - Prevalence of antibody to hepatitis E virus among rodents in the United States.
AB - The recent identification of antibody to hepatitis E virus (HEV) in pigs, sheep,
and cattle and characterization of an HEV isolated from domestic pigs suggest
animal reservoirs for this virus. To investigate whether rodents might be a
natural reservoir of HEV, the prevalence of anti-HEV was determined among a
variety of species throughout the United States. Serum samples were obtained from
806 rodents of 26 species in 15 genera. Anti-HEV prevalence was assessed by 2
EIAs (mosaic protein- and 55-kDa protein-based), which gave concordant results.
The highest prevalence of antibody was found in the genus Rattus (59.7%;
166/278). Overall, rodents from urban habitats had a significantly higher
prevalence of anti-HEV than did animals captured from rural areas. A high
prevalence of anti-HEV was found in animals captured on mainland versus barrier
islands. The results from this study provide convincing evidence of widespread
HEV or HEV-like infection in rodents of the United States.
PMID- 10669326
TI - Type specificity and significance of different isotypes of serum antibodies to
human papillomavirus capsids.
AB - Isotype-specific serum antibody responses against human papillomavirus (HPV) type
16 were evaluated by use of cross-sectional, prospective, and population-based
seroepidemiologic studies. IgG1 and IgA were the most abundant isotypes. No
sample contained IgG2, and <25 samples contained IgG3 or IgM. Total IgG, IgA, and
IgG1 were HPV type specific and were associated with HPV-16 DNA (odds ratios
[ORs], 5.4, 5.0, and 5.9, respectively; P<.001) but not with other HPV DNA (ORs,
1.2, 1.2, and 0.8, respectively; P value was not significant). Total IgG and IgG1
were strongly associated with number of lifetime sex partners (P<.001); IgA was
only associated with number of recent sex partners and lifetime sex partners
among younger women. Total IgG, IgG1, and IgA were associated with cervical
intraepithelial neoplasia type III and also predicted risk of future cervical
neoplasia. IgG and IgG1 appeared to mark lifetime cumulative exposure, whereas
IgA may mark recent or ongoing infection.
PMID- 10669327
TI - Human immunodeficiency virus (HIV) subtype surveillance of African-born persons
at risk for group O and group N HIV infections in the United States.
AB - A population-based surveillance registry was used to identify human
immunodeficiency virus (HIV)-infected persons in the United States at increased
risk for group O and group N infections (those born in or near African countries
where group O infection has been reported). Of 155 eligible subjects, 37 gave
samples. By phylogenetic and serologic analysis, 32 were infected with group M
(16 with subtype A, 5 with B, 7 with C, and 1 each with subtypes D, F2, G, and
recombinant A/J) and 2 with group O but none with group N virus. For 3, samples
could not be typed by serology or amplified by polymerase chain reaction using
group M-, O-, or N-specific primers. In the United States, group O HIV infection
is uncommon; no case of group N infection was found. African-born persons may
have HIV strains typical of their birth country. Ongoing subtype surveillance may
allow early identification of novel or emerging HIV strains.
PMID- 10669328
TI - Presence of human immunodeficiency virus (HIV) type 1, group M, non-B subtypes,
Bronx, New York: a sentinel site for monitoring HIV genetic diversity in the
United States.
AB - In the United States, human immunodeficiency virus (HIV) type 1, group M, subtype
B is the predominant subtype. A cross-sectional study of HIV-infected patients at
the Bronx-Lebanon Hospital Center, Bronx, NY, between September 1997 and February
1998 identified 3 (1. 2%) of 252 persons infected with non-B subtypes: subtypes A
and F, 1 each, and 1 potential recombinant subtype B(env)/F(prt). All 3 persons
were born in the United States and tested positive for HIV antibodies between
1988 and 1997 while living in the Bronx. None reported travel to other countries,
receipt of blood products, or drug injection. This study is among the first to
indicate probable transmission of non-B HIV-1 subtypes in the United States. The
occurrence of non-B HIV-1 subtypes in long-term US residents without a history of
foreign travel may have implications for the evaluation and development of
antiretroviral drugs, vaccines, and tests intended for use in the United States
to diagnose HIV infection and screen blood.
PMID- 10669329
TI - Vaccination of seronegative volunteers with a human immunodeficiency virus type 1
env/rev DNA vaccine induces antigen-specific proliferation and lymphocyte
production of beta-chemokines.
AB - There is a pressing need to test novel vaccine concepts in an effort to develop
an effective vaccine for human immunodeficiency virus (HIV) type 1. A phase I
clinical study was done to test the immunogenicity of an HIV env/rev DNA vaccine,
which was administered intramuscularly to HIV-1-seronegative persons. Subjects
received 3 doses of vaccine at a single concentration (100 or 300 microgram) at
0, 4, 8, and 24 weeks. In at least 1 of multiple assays, the 6 subjects who
received the 300-microgram dose had DNA vaccine-induced antigen-specific
lymphocyte proliferative responses and antigen-specific production of both
interferon-gamma and beta-chemokine. Furthermore, 4 of 5 subjects in the 300
microgram-dose group responded to both the rev and env components of the vaccine.
The responses did not persist within inoculated individuals and scored in
different individuals at different times in the trial. This study supports that
HIV-1 DNA vaccine antigens can stimulate multiple immune responses in vaccine
naive individuals, and it warrants additional studies designed to enhance DNA
vaccine immunogenicity.
PMID- 10669330
TI - Inhibition of human immunodeficiency virus type 1 replication in human
mononuclear blood cells by the iron chelators deferoxamine, deferiprone, and
bleomycin.
AB - Replication of human immunodeficiency virus type 1 (HIV-1) can be influenced by
iron. Hence, decreasing the availability of iron may inhibit HIV-1 replication.
Deferoxamine and deferiprone, both forming catalytically inactive iron-chelator
complexes, and bleomycin, by use of which iron catalyzes oxidative nucleic acid
destruction, were investigated. Expression of p24 antigen in human monocyte
derived macrophages and peripheral blood lymphocytes (PBL) was reduced by all 3
iron chelators. In PBL, p24 reduction was mirrored by a decrease in proliferation
after incubation with deferoxamine or deferiprone, suggesting that viral
inhibition is closely linked to a decrease in cellular proliferation. In
contrast, clinically relevant bleomycin concentrations reduced p24 levels by
approximately 50% without affecting proliferation. When deferoxamine and the
nucleoside analogue dideoxyinosine were used in combination, they acted
synergistically in inhibiting HIV-1 replication. These observations suggest that
iron chelators with different mechanisms of action could be of additional benefit
in antiretroviral combination therapy.
PMID- 10669331
TI - Effect of zidovudine resistance mutations on virologic response to treatment with
zidovudine-lamivudine-ritonavir: genotypic analysis of human immunodeficiency
virus type 1 isolates from AIDS clinical trials group protocol 315.ACTG Protocol
315 Team.
AB - The effect of baseline drug resistance mutations on response to zidovudine,
lamivudine, and ritonavir was evaluated in zidovudine-experienced persons
infected with human immunodeficiency virus type 1 (HIV-1). Presence of the K70R
mutation was associated with significantly higher plasma HIV-1 RNA levels at
baseline. However, presence of resistance mutations did not affect the increase
in plasma HIV-1 RNA during a 5-week drug washout, nor was there any effect on
first-phase virus decay rates after initiation of therapy or on the probability
of having plasma HIV-1 RNA levels <100 copies/mL at week 48. Polymorphisms at
protease codons 10, 36, and 71 were associated with significantly faster second
phase decay rates. Suppression of plasma HIV-1 RNA despite presence of zidovudine
resistance mutations implies that the presence of these mutations does not
preclude a durable response to treatment with a potent 3-drug regimen.
PMID- 10669332
TI - Oral transmission of human immunodeficiency virus by infected seminal fluid and
milk: a novel mechanism.
AB - Salivary transmission by the 30 million human immunodeficiency virus (HIV)
carriers is rare, despite kissing, aerosolization, and dental treatment. The main
protective mechanism of saliva is reported to be inactivation of HIV-transmitting
leukocytes by its unique hypotonicity; however, the successful oral transmission
of HIV by seminal fluid and milk is unexplained. Whether seminal fluid and milk
successfully transmit HIV orally by overcoming the recipient's salivary hypotonic
inactivation of HIV-transmitting leukocytes was tested. Isotonic salt solution
and normal donor samples of milk, colostrum, seminal fluid, and blood were
studied for their ability to overcome the salivary hypotonic inactivation. All
samples, in physiologic volumes, prevented the hypotonic saliva from inactivating
HIV-transmitting leukocytes by providing solutes and retarding diffusion. This
indicates that successful oral transmission of HIV by seminal fluid, milk, and
colostrum may be due to their isotonicity, which overcomes hypotonic salivary
inactivation of HIV-transmitting leukocytes.
PMID- 10669333
TI - RANTES production by T cells and CD8-mediated inhibition of human
immunodeficiency virus gene expression before initiation of potent antiretroviral
therapy predict sustained suppression of viral replication.
AB - A prospective blinded study was conducted to determine whether immunological
differences exist between patients receiving potent antiretroviral therapy who
are able to achieve and maintain an undetectable virus load (<50 copies/mL) and
those who are not. Eleven patients receiving protease inhibitor-containing
antiretroviral therapy were studied for 1 year. After analysis of all baseline
samples, patient virus load was disclosed, and patients were classified as
suppressors (those who maintained undetectable virus load for 1 year) and
nonsuppressors. Baseline virus load and CD4+ T cell count did not differ
significantly between the 2 groups. Levels of RANTES production by CD4+ and CD8+
T cells and CD8-mediated inhibition of human immunodeficiency virus type 1 gene
expression before initiation of antiretroviral therapy were significantly
associated with an undetectable virus load maintained for 1 year (P<.05). Thus, a
functionally intact T cell-mediated immune system at the time of initiation of
potent antiretroviral therapy may predict long-term virus suppression.
PMID- 10669334
TI - Unexpected coreceptor usage of primary human immunodeficiency virus type 1
isolates from viremic patients under highly active antiretroviral therapy.
AB - Recently, combinations of antiretroviral drugs (highly active antiretroviral
therapy [HAART]) have led to a dramatic reduction of human immunodeficiency virus
type 1 (HIV-1)-related clinical symptoms. Success of treatment is defined as
almost complete suppression of plasma viremia, although in a sizable fraction of
patients this goal is not achieved. We characterized primary HIV-1 isolates from
2 cohorts of patients in which HAART failed in terms of viral suppression. One
cohort showed clinical benefit and stable or increasing CD4+ T cell numbers
despite high viral load. The second viremic cohort had no CD4+ T cell recovery
and exhibited typical AIDS-related symptoms. Primary isolates from HAART patients
with minor clinical symptoms used CXCR4 as the most relevant receptor on primary
cells. Thus, for the first time, it is shown that patients improving clinically
under HAART harbor relatively high viral loads with viruses preferring CXCR4 as
coreceptor.
PMID- 10669335
TI - Effect of influenza vaccination on viral replication and immune response in
persons infected with human immunodeficiency virus receiving potent
antiretroviral therapy.
AB - Nineteen patients infected with human immunodeficiency virus (HIV) with varying
levels of viral suppression achieved with antiretroviral therapy were evaluated
to determine whether trivalent influenza vaccine activated HIV replication.
Humoral immune responses and CD4+ lymphocyte subsets were compared in 5 HIV
uninfected vaccinated subjects. Transient elevations of plasma HIV RNA levels (76
89 copies/mL) appeared within 2 weeks in 3 of 11 patients with <50 copies/mL at
baseline. Sustained elevation in HIV plasma RNA was observed in 7 of 8 patients
with baseline HIV RNA of >50 copies/mL. HIV DNA decreased in patients with <400
RNA copies/mL at baseline and showed an HIV RNA increase after vaccination (n=8)
when compared with 8 patients with <50 copies/mL at baseline who lacked viral
response to vaccination. Concurrent decreases in proviral DNA and memory
phenotype CD4+ cells in association with increased plasma HIV RNA after
vaccination in patients with <400 RNA copies/mL at baseline suggest that in vivo
mobilization of the latently infected cell reservoir may occur during potent
antiretroviral therapy.
PMID- 10669336
TI - Secretory anti-human immunodeficiency virus (HIV) antibodies in colostrum and
breast milk are not a major determinant of the protection of early postnatal
transmission of HIV.
AB - The immune response to human immunodeficiency virus (HIV) type 1 was evaluated in
breast milk from HIV-infected African mothers who had transmitted and those who
had not transmitted HIV to their children through breast-feeding. The levels,
specific activities against gp160 and 2 HIV-derived peptides from gp41 and gp120
(V3 loop), and inhibitory activity toward viral transcytosis in vitro of
secretory IgA (S-IgA) and IgG purified from breast milk were investigated in 8
transmitting mothers and 18 nontransmitting mothers. S-IgA and IgG antibodies to
gp160 and to peptides were found in all breast milk samples. The specific
activities of S-IgA and IgG to gp160 and peptides were similar between
transmitting and nontransmitting mothers. No difference of the capacity of S-IgA
and IgG to block HIV transcytosis in vitro was found between the 2 groups. These
results suggest that humoral mucosal immunity to HIV does not appear as a
predominant factor for protection against viral transmission through breast milk.
PMID- 10669337
TI - A randomized study of the safety and antiretroviral activity of hydroxyurea
combined with didanosine in persons infected with human immunodeficiency virus
type 1. American Foundation for AIDS Research Community-Based Clinical Trials
Network.
AB - This randomized open-label trial of human immunodeficiency virus type 1-infected
persons compared safety and efficacy for 38 patients receiving
hydroxyurea/didanosine combination therapy with findings in 42 persons given
didanosine monotherapy for 12 weeks, followed by 12 weeks of
hydroxyurea/didanosine combination therapy for all patients. Week 12 on-treatment
group comparisons showed a mean decrease in virus load between
hydroxyurea/didanosine versus didanosine groups of -0.93 versus -0.74 log10
copies/mL (P=.20); a higher percentage of the hydroxyurea/didanosine group below
the assay's detection limit (500 copies/mL), 29% versus 7% (P=.017); and median
change in CD4 cells for the hydroxyurea/didanosine versus didanosine group of 0
versus 43 cells/mm3 (P=.045), although median change in CD4 percentage was
similar (0.9% vs. 1.2%, P=.64). Week 24 virus load reductions and CD4 cell
changes were similar in both groups. Intent-to-treat and on-treatment analyses
showed similar results. The hydroxyurea/didanosine combination was well
tolerated.
PMID- 10669338
TI - Use of human immunodeficiency virus (HIV) human hyperimmune immunoglobulin in HIV
type 1-infected children (Pediatric AIDS clinical trials group protocol 273).
AB - The clinical, immunologic, and virologic effects and the pharmacokinetics of
human immunodeficiency virus (HIV) human hyperimmune immunoglobulin (HIVIG) were
assessed in 30 HIV-infected children aged 2-11 years. All had moderately advanced
disease with an immune complex-dissociated (ICD) p24 antigen >70 pg/mL and were
on stable antiviral therapy. Three groups of 10 children received 6 monthly
infusions of 200, 400, or 800 mg/kg of HIVIG, and serial immunologic and
virologic assays were performed. HIVIG doses as high as 800 mg/kg were safe and
well tolerated. The half-life of HIVIG, determined by serial p24 antibody titers,
was 13-16 days, the volume of distribution was 102-113 mL/kg, and clearance was
5.6-6.0 mL/kg/day. Plasma ICD p24 decreased during the infusions, but CD4 cell
levels, plasma RNA copy number, cellular virus, immunoglobulin levels, and
neutralizing antibody titers were minimally affected by the infusions. Clinical
status did not change during the 6-month infusion and 3-month follow-up periods.
PMID- 10669339
TI - Genital tract human immunodeficiency virus type 1 (HIV-1) shedding and
inflammation and HIV-1 env diversity in perinatal HIV-1 transmission.
AB - This study sought to identify genital tract characteristics associated with
vertical transmission of human immunodeficiency virus type 1 (HIV-1). HIV-1 DNA
and RNA, HIV-1 env diversity, and inflammatory cells were quantified in
cervicovaginal lavages (CVLs) of 24 women enrolled in the Women and Infants
Transmission Study; 7 women transmitted HIV-1 perinatally. Vaginal candidiasis,
HIV-1 culture positivity, levels of HIV-1 DNA and cell-free RNA, and HIV-1 env
diversity were significantly higher in the CVLs of transmitters. CVL HIV-1 DNA
levels correlated with higher levels of inflammatory cells and cell-free HIV-1
RNA. Of subjects with paired blood and CVL specimens, there was more HIV-1 env
heterogeneity between blood and CVLs in transmitters than in nontransmitters. In
summary, increased HIV-1 shedding is correlated with a more complex population of
HIV-1 quasispecies in the genital tracts of parturient women, which may increase
the probability that a fetotropic strain is transmitted.
PMID- 10669340
TI - T cells overexpressing interferon-gamma and interleukin-10 are found in both the
thymus and secondary lymphoid tissues of feline immunodeficiency virus-infected
cats.
AB - Similar to human immunodeficiency virus type 1, feline immunodeficiency virus
(FIV) replicates in the thymus of infected animals, causing marked alteration in
thymic lymphocyte subpopulations. The immune phenotype and cytokine patterns in
the thymus and secondary lymphoid tissues of FIV-infected cats were investigated.
FIV infection caused an acute-stage transient reduction in CD4CD8 double-positive
thymocytes, a marked increase in CD8 single-positive thymocytes, and formation of
thymic B cell lymphoid follicles. Interferon (IFN)-gamma and interleukin (IL)-10
mRNA were up-regulated in both the thymus and lymph nodes of FIV-infected cats.
Analysis of purified CD4 and CD8 cells revealed that CD4 cells produced most of
the IL-10, whereas IFN-gamma was produced by both subsets. Quantitative
competitive reverse-transcription polymerase chain reaction analysis revealed
that thymocytes, especially CD4CD8 thymocytes, had much greater levels of gag
mRNA than did lymph node T cells. Thus, overexpression of IFN-gamma and IL-10 is
a feature of the thymus and secondary lymphoid tissues of FIV-infected cats.
PMID- 10669342
TI - Intravaginal practices, vaginal flora disturbances, and acquisition of sexually
transmitted diseases in Zimbabwean women.
AB - One hundred sixty-nine Zimbabwean women were studied to determine whether the use
of intravaginal practices (cleaning with the fingers, wiping the vagina, and
inserting traditional substances) are associated with disturbances of vaginal
flora and acquisition of sexually transmitted diseases (STDs). Subjects were
interviewed and received counseling and a pelvic examination at enrollment, 1
month, and 6 months, and vaginal specimens were collected at enrollment and at 6
months. Users were more likely than nonusers to have vaginal flora disturbances
but were not more likely to acquire an STD (relative risk [RR], 2.15; P=.188).
Certain vaginal flora disturbances were associated with increased STD incidence
and HIV prevalence. The absence of lactobacilli from the vaginal flora was
associated with being positive for human immunodeficiency virus in baseline (odds
ratio [OR], 0.24; P=.001) and 6-month transition multivariate models (OR, 0.39;
P=.025). The presence of clue cells at baseline was associated with a higher
incidence of STDs (RR, 1. 94; P=.025).
PMID- 10669341
TI - Exogenous glucocorticoids alter parameters of early feline immunodeficiency virus
infection.
AB - Feline immunodeficiency virus (FIV), a lentivirus, causes progressive
immunosuppression and neurologic dysfunction in cats. Glucocorticoids are common
therapeutic agents that are also immunosuppressive, and their use might enhance
the pathogenic effects of lentivirus infections. Methylprednisolone acetate, a
long-acting glucocorticoid, was administered to cats before FIV inoculation, and
the course of early infection was monitored. The humoral immune response to FIV
was not affected by corticosteroid treatment, but CD8+ cell-mediated antiviral
activity was poor in cultures from FIV-infected cats treated with
methylprednisolone. Steroid-treated cats had higher plasma viral RNA levels than
untreated cats during acute viremia. In contrast, FIV-associated changes in brain
stem auditory-evoked potentials were slow to develop in the methylprednisolone
treated cats. Methylprednisolone treatment of cats with established FIV
infections appeared to reverse these neurophysiologic changes. These results
emphasize the complexity of host-lentivirus interactions and suggest potential
advantages and drawbacks of using glucocorticoids in lentivirus infections.
PMID- 10669343
TI - Effects of contraceptive method on the vaginal microbial flora: a prospective
evaluation.
AB - A prospective evaluation of 331 university women who were initiating use of oral
contraceptive pills (OCPs), a cervical cap, diaphragm-spermicide, or other
spermicidal methods was done to assess the effects of commonly used contraceptive
methods on the vaginal flora. Vaginal introital cultures were performed at
baseline and then weekly for 1 month. The prevalence of Escherichia coli vaginal
colonization and of abnormal vaginal Gram stain scores (Nugent criteria)
increased significantly among women using a cervical cap or diaphragm-spermicide
but not among women using OCPs. Women with E. coli colonization were
significantly more likely to have an abnormal Nugent score and an absence of
lactobacilli. In a multivariate model, use of spermicidal contraception in the
preceding week was associated with an abnormal Nugent score and with colonization
with E. coli, Enterococcus species, and anaerobic gram-negative rods. Thus,
spermicidal methods of contraception are associated with alterations of the
vaginal microflora that consequently may predispose women to genitourinary
infections.
PMID- 10669344
TI - Expression of and cytokine activation by Escherichia coli curli fibers in human
sepsis.
AB - Curli organelles are expressed by commensal Escherichia coli K12 and by
Salmonella typhimurium at temperatures <37 degrees C, which bind serum proteins
and activate the contact-phase system in vitro. This study demonstrates, by means
of an anti-CsgA (curli major subunit) antibody, that a significant fraction of E.
coli isolates (24 of 46) from human blood cultures produce curli at 37 degrees C
in vitro. Serum samples from 12 convalescent patients with sepsis, but not serum
from healthy controls, contained antibodies against CsgA (n=12). This study
further demonstrates that a curli-expressing E. coli strain and a noncurliated
mutant secreting soluble CsgA induce significantly (P<.05) higher levels of
proinflammatory cytokines (tumor necrosis factor-alpha, interleukin [IL]-6, and
IL-8) in human macrophages differentiated from THP-1 cells. These data,
therefore, provide direct evidence that curli are expressed in vivo in human
sepsis and suggest a possible role for curli and CsgA in the induction of
proinflammatory cytokines during E. coli sepsis.
PMID- 10669345
TI - Interleukin 10 inhibits the release of CC chemokines during human endotoxemia.
AB - Sixteen healthy subjects were intravenously injected with lipopolysaccharide
(LPS), once with placebo and once with recombinant human interleukin (IL)-10 (25
microgram/kg), to determine the effect of IL-10 on LPS-induced production of
macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and monocyte
chemoattractant protein (MCP)-1. LPS induced transient increases in serum MIP
1alpha, MIP-1beta, and MCP-1. Pretreatment with IL-10 inhibited LPS-induced
release of MIP-1alpha, MIP-1beta, and MCP-1. In whole blood in vitro, the IL-10
induced inhibition of MIP-1alpha and MIP-1beta release was equally potent in the
presence or absence of an anti-tumor necrosis factor (TNF) antibody. Although
isolated peripheral blood mononuclear cells produced more MIP-1alpha and MIP
1beta than neutrophils, the latter cells were more sensitive to the inhibiting
effect of IL-10. IL-10 attenuates LPS-induced production of CC chemokines in
human endotoxemia, whereby in vitro experiments suggest that, in the case of MIP
1alpha and MIP-1beta release, this effect is independent from an inhibitory
effect on TNF production.
PMID- 10669346
TI - Prognostic value of cytokine concentrations (tumor necrosis factor-alpha,
interleukin-6, and interleukin-10) and clinical parameters in severe melioidosis.
AB - Raised serum concentrations of tumor necrosis factor (TNF)-alpha, interleukin
(IL)-1beta, IL-6, or IL-10 are associated with mortality in patients with sepsis,
but it is not known whether elevated cytokine levels are independently predictive
of mortality. Cytokine assays (TNF-alpha, IL-6, and IL-10) were performed on
admission plasma samples from 172 adult Thai patients with severe melioidosis.
Mortality was 31.4%. APACHE II score; septicemia; plasma lactate; TNF-alpha, IL
6, and IL-10 concentrations; and IL-10/TNF-alpha and IL-6/IL-10 ratios were each
associated with outcome (P=.001 for all variables). Only the APACHE II score
and either IL-6 or IL-10 concentration were independent predictors of mortality,
as determined by use of multiple logistic regression (with cytokine
concentrations and ratios entered separately). In a multivariate analysis,
including both IL-6 and IL-10, the IL-10 concentration was no longer predictive.
Therefore, APACHE II scores and either IL-6 or IL-10 concentration may be the
most reliable parameters for stratification of patients in future studies of
severe gram-negative sepsis.
PMID- 10669347
TI - Factors associated with Helicobacter pylori infection by a cagA-positive strain
in children.
AB - Although infection with a cagA-positive Helicobacter pylori strain is considered
a risk factor for the development of duodenal peptic ulcer in adults, this
association has not been demonstrated in children. The presence of cagA was
investigated by polymerase chain reaction in H. pylori strains isolated from 27
children with duodenal ulcer and 53 without duodenal ulcer. All patients (100%)
with duodenal ulcer and 33 (62.3%) without ulcer were colonized by a cagA
positive strain (P=.00007). A cagA-positive status was also associated with a
more marked macroscopic gastritis, with a greater inflammatory infiltrate of both
mononuclear and polymorphonuclear cells in the antral and oxyntic gastric mucosae
and degenerative and regenerative changes of the gastric mucosa. Increased cagA
positivity was also associated with increased age, but no association between
cagA-positive status and sex was observed.
PMID- 10669348
TI - Invasive group A streptococcal disease in the Netherlands: evidence for a
protective role of anti-exotoxin A antibodies.
AB - As part of a nationwide surveillance in The Netherlands during 1994-1997, 53
patients with invasive group A streptococcal (GAS) infections were evaluated for
medical history, symptoms, and outcome. Patients' isolates were tested for the
production of pyrogenic exotoxins A (SPE-A) and B (SPE-B). Acute-phase sera from
all patients and convalescent sera from 12 patients were investigated for the
presence of antibodies against SPE-A and SPE-B. Twenty-three patients developed
toxic shock-like syndrome and 16 died. Absence of antibodies against SPE-A and/or
SPE-B was a risk factor for developing invasive streptococcal disease. Toxic
shock and mortality were associated with a lack of anti-SPE-A antibodies
(P<.025). Anti-SPE-A antibodies were found in convalescent sera from all patients
infected by speA-positive isolates. Virtually all invasive speA-positive
streptococci expressed SPE-A protein in vitro. Thus antibodies against SPE-A
appeared vital for mediating the outcome of invasive GAS disease in this
population.
PMID- 10669349
TI - A pivotal role for interferon-gamma in protection against group A streptococcal
skin infection.
AB - Administration of exogenous recombinant interleukin-12 (rIL-12) either
prophylactically or therapeutically provides significant protection against
lethal group A streptococcal skin infection in a mouse model. Treatment of mice
with rIL-12 before infection with group A streptococci induced expression of
interferon-gamma (IFN-gamma) at the infection site. In vivo neutralization of IFN
gamma increased susceptibility to lethal infection and completely abrogated the
protective effects of rIL-12. IFN-gamma knockout mice were also more susceptible
to lethal infection. Although IL-12 treatment provided protection, higher doses
induced significantly elevated levels of IFN-gamma transcription that were
associated with increased susceptibility to lethal infection. These results
support the hypothesis that IFN-gamma at the infection site is critical for
protection but suggest that increased systemic levels are detrimental to survival
after infection with group A streptococci.
PMID- 10669351
TI - Maternal antibody transfer in baboons and mice vaccinated with a group B
streptococcal polysaccharide conjugate.
AB - Two animal models were used to study maternal transfer of antibody to a group B
Streptococcus (GBS) type III polysaccharide-tetanus toxoid (III-TT) conjugate.
The III-TT vaccine protected all 27 mouse pups born to vaccinated dams against a
GBS challenge. In a separate study of vaccinated mouse dams and pups, maternal
sera contained all 4 subclasses of polysaccharide-specific IgG, with IgG1
accounting for 83% of total IgG. Specific IgG subclass distribution
(IgG1>>IgG2a=IgG2b=IgG3) in newborn pups closely resembled that in their mothers.
Seven of 9 female baboons given the III-TT vaccine had 5- to 36-fold increases in
specific antibody from baseline levels; they transferred 26%-185% of specific
antibody to their offspring. Matched maternal and neonatal sera obtained at
delivery were functionally equivalent in an in vitro opsonophagocytosis assay.
These preclinical studies provide further evidence for effective immunogenicity
of GBS conjugate vaccine and efficient transport of functionally active maternal
antibody.
PMID- 10669350
TI - Role of Streptococcus pneumoniae and Haemophilus influenzae in the development of
acute otitis media and otitis media with effusion in a gerbil model.
AB - The efficacy of amoxicillin/clavulanate and cefuroxime was determined in a gerbil
model of otitis media with a mixed Streptococcus pneumoniae plus Haemophilus
influenzae middle ear (ME) infection. Results were compared with those obtained
in a previous single H. influenzae model. All untreated animals inoculated with
the mixed inoculum developed acute otitis media (AOM), whereas 86.7% of those
inoculated with H. influenzae developed otitis media with effusion (OME).
Antibiotics eradicated H. influenzae from the ME more efficiently in AOM than in
OME, and this difference was highly significant (P=.001) after administration
of 5 mg/kg of either drug (amoxicillin/clavulanate, 100% vs. 10%; cefuroxime,
73.3% vs. 10%). Efficacy was predicted by the relation of in vitro susceptibility
and ME antibiotic concentration, which was 2.7 times higher in AOM than in OME.
In the mixed otitis model, the most efficacious antibiotic was able to prevent
AOM, but >80% of animals developed culture-negative OME.
PMID- 10669352
TI - Analysis of the pathogenicity locus in Clostridium difficile strains.
AB - The genes for Clostridium difficile toxins A and B (tcdA and tcdB) are part of a
19.6-kb pathogenicity locus (PaLoc) that includes the genes tcdD, tcdE, and tcdC.
To determine whether the C. difficile PaLoc is a stable and conserved genetic
unit in toxigenic strains, a multiplex polymerase chain reaction was used to
analyze 50 toxigenic, 39 nontoxigenic, and 2 toxin-defective isolates. The
respective amplicons were identified for tcdA-E in the toxigenic isolates; these
were absent in the nontoxigenic isolates. C. difficile P-829 lacked at least a
fragment of tcdD, tcdB, tcdE, and tcdC, but tcdA was present. C. difficile 8864
had deletions in the tcdA and tcdC genes. These data suggest that the PaLoc is
highly stable in toxigenic C. difficile, nontoxigenic isolates lack the unit, and
isolates with a defective PaLoc can still cause clinical disease. Further studies
are needed to define the role of individual genes in the pathogenesis of C.
difficile-associated diarrhea.
PMID- 10669353
TI - Quinolone antibiotics induce Shiga toxin-encoding bacteriophages, toxin
production, and death in mice.
AB - Shiga toxin-producing Escherichia coli (STEC) cause significant disease;
treatment is supportive and antibiotic use is controversial. Ciprofloxacin but
not fosfomycin causes Shiga toxin-encoding bacteriophage induction and enhanced
Shiga toxin (Stx) production from E. coli O157:H7 in vitro. The potential
clinical relevance of this was examined in mice colonized with E. coli O157:H7
and given either ciprofloxacin or fosfomycin. Both antibiotics caused a reduction
in fecal STEC. However, animals treated with ciprofloxacin had a marked increase
in free fecal Stx, associated with death in two-thirds of the mice, whereas
fosfomycin did not. Experiments that used a kanamycin-marked Stx2 prophage
demonstrated that ciprofloxacin, but not fosfomycin, caused enhanced
intraintestinal transfer of Stx2 prophage from one E. coli to another. These
observations suggest that treatment of human STEC infection with bacteriophage
inducing antibiotics, such as fluoroquinolones, may have significant adverse
clinical consequences and that fluoroquinolone antibiotics may enhance the
movement of virulence factors in vivo.
PMID- 10669355
TI - Genetic evidence for the role of the Lv locus in early susceptibility but not IL
10 synthesis in experimental coccidioidomycosis in C57BL mice.
AB - Loci on chromosome 4 near Lv and on chromosome 6 near Tnfr1 are associated with
resistance to coccidioidomycosis in mice. To assess the importance of the Lv
locus, we compared C57BL/6 (B6) with C57BL/10 (B10), strains that are nearly
congenic for the Lv locus. Fourteen days after intraperitoneal infection, B6 mice
had nearly 100-fold more Coccidioides immitis in their lungs than did B10 mice
(log 6.2 vs. log 4.8). Furthermore, the time to 50% deaths was 15 days for B6 and
22 days for B10. Nevertheless, 90% of B10 mice had died by day 28. In other mouse
strains, we found a direct correlation between lung colony-forming units and
levels of interleukin (IL)-10 and IL-4 mRNA, but B10 mice had 100-fold higher
lung levels of IL-10 and 10-fold higher levels of IL-4 mRNA than did B6 mice,
despite having less C. immitis. In the absence of IL-10, B10 mice are resistant
to lethal infection. These results suggest that a locus near Lv is responsible
for early resistance to coccidioidomycosis but not for modulating the IL-10 and
IL-4 responses. This locus is not sufficient to make C57BL mice resistant to
coccidioidomycosis.
PMID- 10669354
TI - Rapid neutrophil response controls fast-replicating intracellular bacteria but
not slow-replicating Mycobacterium tuberculosis.
AB - Being one of the first cells to invade the site of infection, neutrophils play an
important role in the control of various bacterial and viral infections. In the
present work, the contribution of neutrophils to the control of infection with
different intracellular bacteria was investigated. Mice were treated with the
neutrophil-depleting monoclonal antibody RB6-8C5, and the time course of
infection in treated and untreated mice was compared by using intracellular
bacterial species and strains varying in virulence and replication rate. The
results indicate that neutrophils are crucial for the control of fast-replicating
intracellular bacteria, whereas early neutrophil effector mechanisms are
dispensable for the control of the slow-replicating Mycobacterium tuberculosis.
PMID- 10669356
TI - Host immune reactivity determines the efficacy of combination immunotherapy and
antifungal chemotherapy in candidiasis.
AB - In immunocompetent mice with candidiasis, successful therapy with amphotericin B
and fluconazole relies on the induction of protective, T helper (Th) type 1
responses, an effect potentiated by concomitant interleukin (IL)-4
neutralization. To assess the therapeutic efficacy of combined treatments with
antifungals and immunomodulators in conditions of immunosuppression, leukopenic
or neutropenic mice with disseminated candidiasis were treated with amphotericin
B or fluconazole alone or in combination with soluble IL-4 receptor (sIL-4R) or
recombinant (r) IL-12 or IL-10 neutralizing monoclonal antibodies. We found that
(1) the synergistic effect of sIL-4R and antifungals is retained in
immunocompromised mice; (2) synergism with amphotericin B was superior to that
with fluconazole, particularly in leukopenic mice; (3) rIL-12 synergized with
fluconazole in neutropenic mice; and (4) IL-10 neutralization was always of
limited efficacy. This study indicates that the therapeutic efficacy of
antifungals is differentially potentiated by cytokines or cytokine antagonists
and is influenced by host immune reactivity.
PMID- 10669357
TI - An outbreak of cryptosporidiosis linked to a foodhandler.
AB - In September and October 1998, a cryptosporidiosis outbreak occurred on a
Washington, DC, university campus. In a case-control study of 88 case patients
and 67 control subjects, eating in 1 of 2 cafeterias was associated with
diarrheal illness (P<.001). Morbidity was associated with eating dinner on 22
September (odds ratio, 8.1; 95% confidence interval, 3.4-19.5); weaker
associations were found for 6 other meals. Cryptosporidium parvum was detected in
stool specimens of 16 (70%) of 23 ill students and 2 of 4 ill employees. One ill
foodhandler with laboratory-confirmed C. parvum prepared raw produce on 20-22
September. All 25 Cryptosporidium isolates submitted for DNA analysis, including
3 from the ill foodhandler, were genotype 1. This outbreak illustrates the
potential for cryptosporidiosis to cause foodborne illness. Epidemiologic and
molecular evidence indicate that an ill foodhandler was the likely outbreak
source.
PMID- 10669358
TI - Interferon-gamma expression in jejunal biopsies in experimental human
cryptosporidiosis correlates with prior sensitization and control of oocyst
excretion.
AB - To investigate the role of interferon (IFN)-gamma in human cryptosporidiosis,
jejunal biopsies from experimentally infected volunteers and chronically infected
AIDS patients were examined for IFN-gamma expression by in situ hybridization.
IFN-gamma expression was compared with oocyst excretion, baseline serum anti
Cryptosporidium antibody, and symptoms. IFN-gamma mRNA was detected in biopsies
from 13 of 26 volunteers after experimental infection but not in biopsies taken
before C. parvum exposure or in biopsies from patients with AIDS-associated
cryptosporidiosis. After challenge, 9 of 10 volunteers with baseline C. parvum
antibody produced IFN-gamma, compared with 4 of 16 volunteers without baseline
antibody (P<.01). Furthermore, IFN-gamma mRNA was detected in 9 of 13 volunteers
who did not excrete oocysts, compared with 4 of 13 with organisms (P<.05). Thus,
expression of IFN-gamma in the jejunum was associated with prior sensitization
and absence of oocyst shedding. IFN-gamma production may explain the resistance
to infection noted in sensitized persons but may not be involved in control of
human primary infection.
PMID- 10669359
TI - Continued transmission of West Nile virus to humans in southeastern Romania, 1997
1998.
AB - After an epidemic of West Nile (WN) virus neurologic infections in southeastern
Romania in 1996, human and animal surveillance were established to monitor
continued transmission of the virus. During 1997 and 1998, neurologic infections
were diagnosed serologically as WN encephalitis in 12 of 322 patients in 19
southeastern districts and in 1 of 75 Bucharest patients. In addition, amid a
countrywide epidemic of measles, the etiology of the febrile exanthem in 2 of 180
investigated cases was determined serologically to be WN fever; 1 case was
complicated by hepatitis. Sentinel chickens placed in Bucharest seroconverted to
WN virus during the summer months, indicating their potential value in monitoring
transmission. The continued occurrence of sporadic WN infections in southeastern
Romania in consecutive years after the 1996 epidemic is consistent with local
enzootic transmission of the virus.
PMID- 10669360
TI - Selection of multiresistant hepatitis B virus during sequential nucleoside
analogue therapy.
AB - Hepatitis B virus (HBV) drug resistance to lamivudine is always accompanied by
mutations in the viral polymerase gene at position 550, termed group 1 (M550V
with L526M) or group 2 (M550I) mutations. The latter mutation has not been
associated with famciclovir resistance. Thus, the addition of famciclovir to
lamivudine therapy in persons with group 2 lamivudine resistance may lead to
virus suppression. The effect of lamivudine/famciclovir combination therapy on
HBV infection was monitored in 5 lamivudine-resistant patients by quantitative
polymerase chain reaction and polymerase gene sequencing of serum virus. No
patients treated with combination therapy had a decline in HBV load >1 log10.
Continual evolution of the viral polymerase was detected in association with
virologic resistance to both drugs. Cloning experiments identified the
preexistence of these multidrug-resistant virus variants as minority species
prior to addition of famciclovir therapy. HBV resistance to lamivudine
monotherapy is associated with a complex mixture of variants that limit the
efficacy of second-line nucleoside-analogue therapy. First-line potent
combination therapy may reduce the emergence of HBV drug resistance.
PMID- 10669361
TI - Cytomegalovirus (CMV) DNA load predicts relapsing CMV infection after solid organ
transplantation.
AB - Cytomegalovirus (CMV) DNA load was analyzed as a marker for relapse of CMV
infection in 24 solid organ transplant patients with CMV infection or disease who
received a fixed 14-day course of intravenous ganciclovir. Viral load was
measured in blood samples obtained before and at the completion of treatment.
Eight (33%) of 24 patients developed relapsing CMV infection. Median pretreatment
viral loads were higher in the relapsing group (80,150 copies/106 leukocytes)
than in the nonrelapsing group (5500 copies/106 leukocytes; P=.007). The
relapsing group also had persistent detectable viral DNA (median, 5810 copies/106
leukocytes) after treatment, whereas it was undetectable in the nonrelapsing
group (P<. 0001). Primary CMV infection (seronegative recipients of seropositive
organs, D+R-) was an independent marker for CMV relapse (P=.03), and these
patients had higher pre- and posttreatment viral loads than did non-D+/R-
patients (P<.0001 and P=.0014, respectively). CMV DNA load is a useful marker for
individualizing antiviral treatment of CMV infection in solid organ transplant
recipients.
PMID- 10669362
TI - Uninfected and cytomegalic endothelial cells in blood during cytomegalovirus
infection: effect of acute rejection.
AB - After transplantation, human cytomegalovirus (HCMV) infections can cause vascular
damage to both the graft and the host. To study a possible relationship between
the degree of vascular injury, clinical symptoms of HCMV infection, and
transplant rejection, the appearance and numbers of endothelial cells (ECs) in
blood of 54 kidney transplant recipients were investigated in a prospective
clinical study. Two types of endothelial cells were identified: cytomegalic ECs
(CECs) were detected in patients with moderate or high HCMV antigenemia, and
uninfected ECs were observed in patients with and without HCMV infection. The
incidence of either CECs, ECs, or the combination of both was associated with
HCMV-related clinical symptoms (P<.01). Remarkably, the occurrence of rejection
episodes before HCMV infection was an important risk factor for the occurrence of
ECs in blood (ECs, CECs, or both) during HCMV infection (P<.001).
PMID- 10669363
TI - Comparison of the safety, vaccine virus shedding, and immunogenicity of influenza
virus vaccine, trivalent, types A and B, live cold-adapted, administered to human
immunodeficiency virus (HIV)-infected and non-HIV-infected adults.
AB - Fifty-seven human immunodeficiency virus (HIV)-infected (CDC class A1-2) and 54
non-HIV-infected adults, not prescreened for influenza susceptibility, were
randomized to receive trivalent live attenuated influenza vaccine (LAIV) or
placebo intranasally. LAIV was safe and well tolerated with no serious adverse
events attributable to vaccine. Reactogenicity rates were similar in LAIV and
placebo recipients except that runny nose/nasal congestion was significantly more
common in LAIV recipients regardless of HIV status. No prolonged shedding of LAIV
was observed in HIV-infected participants. HIV RNA levels were not increased and
CD4 counts were not decreased in HIV-infected LAIV recipients compared with
placebo recipients after immunization. Shedding of LAIV and increases in antibody
titers were infrequent, consistent with prior experience in unscreened adults.
The data suggest that inadvertent vaccination with LAIV in relatively
asymptomatic HIV-infected adults would not be associated with frequent
significant adverse events.
PMID- 10669364
TI - Human immunodeficiency virus-infected persons with mutations conferring
resistance to zidovudine show reduced virologic responses to hydroxyurea and
stavudine-lamivudine.
AB - The baseline predictors of poor virologic response (<0.5 log decrease in plasma
virus load) were examined in two 1996 pilot trials of combination nucleoside
analogue therapy. One trial examined the addition of hydroxyurea to didanosine
therapy; the other examined stavudine-lamivudine in combination. In both,
predictors of virologic response included the presence of mutations associated
with zidovudine resistance. For hydroxyurea, the odds ratio (OR) of failure to
achieve a short-term (4 weeks) virologic response in a bivariate logistic
regression model was 30.8 (95% confidence interval [CI], 1.75-543; P=.02) for use
of lower dose hydroxyurea (500 mg/day) and 14.7 (95% CI, 1.1-200; P=.04) for the
presence of a zidovudine-related mutation. For the stavudine-lamivudine study,
the OR of failure to achieve a virologic response at 4 weeks in a multivariate
logistic regression model was 23 (95% CI, 2.7-199; P=.004) for the presence of a
mutation at codon 215.
PMID- 10669365
TI - Effect of interleukin (IL)-15 priming on IL-12 and interferon-gamma production by
pathogen-stimulated peripheral blood mononuclear cells from human
immunodeficiency virus-seropositive and -seronegative donors.
AB - Hypoproduction of the cytokines interleukin (IL)-12 and interferon (IFN)-gamma is
thought to contribute to the impaired immunity seen in human immunodeficiency
virus (HIV)-infected persons. The effects of priming with IL-15 on the production
of IL-12 and IFN-gamma by stimulated peripheral blood mononuclear cells (PBMC)
from HIV-seronegative and -seropositive donors were studied. Stimuli included 3
pathogens that commonly infect HIV-positive persons-Cryptococcus neoformans,
Candida albicans, and Mycobacterium tuberculosis-plus Staphylococcus aureus.
Following IL-15 priming of HIV-negative PBMC, pathogen-stimulated IL-12 and IFN
gamma production increased 5-58-fold. However, for the HIV-positive PBMC, IL-15
priming did not lead to significant increases in pathogen-stimulated IL-12
production and caused only modest increases in IFN-gamma production. These data
suggest that IL-15 alone may be insufficient to correct the defect in IL-12 and
IFN-gamma production in HIV-positive persons.
PMID- 10669366
TI - Secretor polymorphism and human immunodeficiency virus infection in Senegalese
women.
AB - The FUT2 gene encodes the enzyme alpha (1,2) fucosyltransferase, which determines
expression of blood-group antigens on mucosal epithelial cell surfaces and in
secretions. Homozygotes for a specific stop mutation in FUT2 (nonsecretors)
cannot produce this enzyme and thus are unable to express blood group antigens.
Nonsecretor status is associated with a decreased risk of several respiratory
viral infections. By use of molecular genotyping, 2 populations of Senegalese
women were examined for polymorphisms of the FUT2 gene. Among Senegalese
commercial sex workers, absence of FUT2 (nonsecretor genotype) was associated
with reduced risk of human immunodeficiency virus (HIV) type 1 infection (odds
ratio [OR] adjusted for cervical and vaginal infection, 0.18; 95% confidence
interval [CI], 0.04-0.90) and HIV-2 infection (adjusted OR, 0.43; 95% CI, 0.13
1.39), although the latter was not statistically significant. Modification of
cell surface carbohydrates at mucosal surfaces determined by the FUT2 gene may
underlie the protective association against heterosexual HIV infection.
PMID- 10669367
TI - Antiretroviral resistance mutations in human immunodeficiency virus type 1
reverse transcriptase and protease from paired cerebrospinal fluid and plasma
samples.
AB - Twenty-four adults infected with human immunodeficiency virus type 1 (HIV-1) with
central nervous system symptoms were studied for antiretroviral resistance
mutations in HIV-1 RNA obtained from paired cerebrospinal fluid (CSF) and plasma
samples. Paired sequences were obtained from 21 and 13 patients for reverse
transcriptase (RT) and for protease, respectively. Mutations conferring
resistance to the RT inhibitors zidovudine, lamivudine, or nevirapine were
detected in 14 patients, including 11 pretreated and 3 drug-naive subjects. The
mutation patterns in the 2 compartments were different in most patients.
Genotypic resistance to protease inhibitors was detected in both plasma and CSF
from 1 patient treated with multiple protease inhibitors. However, accessory
protease inhibitor resistance mutations at polymorphic sites were different in
plasma and CSF in several patients. Partially independent evolution of viral
quasispecies occurs in plasma and CSF, raising the possibility that
compartmentalization of drug resistance may affect response to antiretroviral
treatment.
PMID- 10669368
TI - Effect of human immunodeficiency virus (HIV) type 1 viral genotype on mother-to
child transmission of HIV-1.
AB - The objective of this study was to determine whether the maternal infecting human
immunodeficiency virus (HIV) type 1 clade affects mother-to-child transmission
frequency. Mothers in the mother-to-child HIV-1 transmission study in Nairobi,
Kenya, were grouped by HIV-1 status of their first enrolled child: uninfected,
perinatally infected, or postnatally infected. Restriction fragment length
polymorphism (RFLP) analysis was used to determine HIV-1 viral clades of nested
polymerase chain reaction products from HIV-1 protease or p24 genes. When
inconclusive, sequencing determined the clade. Clade distributions within the
groups were compared. The 3 groups displayed a uniform clade distribution. The
predominant clades were A (59%) and D (20%). Clades B, C, F, mixed, and
recombinant infections comprised the remainder (21%). No significant association
was seen between clades A and D and either frequency or mode of vertical
transmission. RFLP analysis revealed 2 clade B infections, 9 mixed, and 5
p24/protease recombinant infections in the study population.
PMID- 10669369
TI - Stability of Borrelia burgdorferi outer surface protein C under immune selection
pressure.
AB - Outer surface protein (Osp) C immune pressure during persistent infection with
Borrelia burgdorferi was examined in relation to genetic variation of ospC. Mice
were infected with clonal B. burgdorferi sensu stricto (s.s.) N40 or B. afzelii
PKo and then were hyperimmunized with homologous recombinant OspC or with decorin
binding protein A (DbpA) (controls). After 6 months, B. burgdorferi isolates were
subjected to restriction enzyme analysis of the amplified ospC genes and were
found to have no differences among 9 B. burgdorferi s.s. N40 and 9 B. afzelii PKo
isolates from OspC hyperimmune mice or among 10 B. burgdorferi s.s. N40 and 10 B.
afzelii PKo isolates from DbpA hyperimmune mice, compared with input inocula.
Comparison of gene sequences among 4 B. burgdorferi s.s. N40 and 9 B. afzelii PKo
isolates from OspC-immunized mice revealed no ospC variation from input inocula.
Variation in ospC among B. burgdorferi isolates and species during chronic
infection is not likely to be an important mechanism for immune evasion.
PMID- 10669370
TI - Recombinant human interleukin-11 has anti-inflammatory actions yet does not
exacerbate systemic Listeria infection.
AB - To determine whether recombinant human (rh) interleukin (IL)-11 disrupts the
clearance of microbial pathogens, mice were challenged with Listeria
monocytogenes after receiving high-dose rhIL-11, anti-tumor necrosis factor (TNF)
monoclonal antibody (MAb), anti-IL-11 MAb, or saline control. The LD50 was not
affected by rhIL-11 but was 10-fold lower in the anti-TNF MAb group (P<.001).
Plasma IL-6, IL-1beta, and TNF-alpha levels were not different between rhIL-11
treated animals and the control group; however, interferon-gamma levels were
significantly reduced by IL-11 treatment (2477 vs. 0 pg/mL, P<.01). Compared with
the control group, the quantitative level of L. monocytogenes in hepatic and
splenic tissue was unchanged by rhIL-11 but was significantly increased by TNF or
IL-11 inhibition. The results indicate that IL-11 down-regulates cytokine
production but does not exacerbate systemic infection in the murine Listeria
infection model.
PMID- 10669371
TI - Pneumococcal vaccine response in cirrhosis and liver transplantation.
AB - Cirrhosis is a major risk factor for severe pneumococcal infection, and patients
evaluated for liver transplantation routinely receive pneumococcal vaccine. This
study followed serologic antibody levels of 45 adults evaluated for
transplantation and 13 age-matched control subjects. All received 23-valent
pneumococcal polysaccharide vaccine (PPS). Serum anti-PPS levels and antibodies
specific for capsular types 3 and 23 were measured by ELISA before and 1 and 6
months after vaccination. Antibody levels for the 25 patients who received
transplants also were measured immediately before and 3 months after
transplantation. Control subjects had higher IgG responses to the whole vaccine,
whereas patients appeared to produce more IgM and IgA. IgA, and possibly IgM
levels, also declined faster in patients than in control subjects. All anti-PPS
levels were at or below prevaccination baselines by 3 months after
transplantation. These data suggest that vaccination with PPS may not be
effective for patients during and after liver transplantation.
PMID- 10669372
TI - Meningococcal C polysaccharide vaccine induces immunologic hyporesponsiveness in
adults that is overcome by meningococcal C conjugate vaccine.
AB - Widespread use of meningococcal AC polysaccharide (MACP) vaccines has raised
concerns about induction of hyporesponsiveness to C polysaccharide. Whether
meningococcal C conjugate (MCC) vaccine overcomes any immunologic refractoriness
following MACP vaccination in adults was investigated. University students
vaccinated 6 months previously with MACP vaccine were randomized to receive MACP
or MCC vaccine, and antibody responses were compared with those of previously
unvaccinated students receiving MACP or MCC vaccine. In students primed with MACP
vaccine, MCC vaccine induced significantly higher IgG and serum bactericidal
antibody levels than did a second dose of MACP vaccine. Responses to a second
dose of MACP vaccine were significantly lower than to the first dose. Previous
receipt of MACP vaccine reduced serum bactericidal antibody but not IgG responses
to MCC vaccine compared with those in previously unvaccinated students. This
confirms that MACP vaccine induces immunologic hyporesponsiveness to C
polysaccharide in adults, but this can be overcome with MCC vaccine. Repeated
vaccination with MACP vaccine may be ineffective, and MCC vaccines should provide
better long-term protection.
PMID- 10669373
TI - Penetration of clinical isolates of Pseudomonas aeruginosa through MDCK
epithelial cell monolayers.
AB - Pseudomonas aeruginosa causes both invasive (bacteremic) and chronic noninvasive
infections. A simple in vitro system to screen P. aeruginosa clinical isolates
for their capacity to penetrate MDCK cell monolayers has been developed. By means
of this system, P. aeruginosa clinical isolates, including 32 blood and 45
respiratory isolates, were examined. When monolayers were infected with 3.5x107
cfu of bacteria, significantly more blood (93.7%) than respiratory (54.4%)
isolates (P<.001) were detected in the basolateral medium after 3 h. Penetration
ability was usually independent of cytotoxicity. Only 8 (4 blood and 4
respiratory) isolates were cytotoxic, possessed exoU, and passed through the
monolayer after epithelial cell death, associated with a marked drop in
transepithelial electrical resistance. Conversely, noncytotoxic isolates with
high penetration ability but without severe epithelial damage were invasive. This
system is well suited for screening clinical isolates and their mutants for
specific genes conferring the invasiveness phenotype.
PMID- 10669374
TI - Poly(sodium 4-styrene sulfonate): an effective candidate topical antimicrobial
for the prevention of sexually transmitted diseases.
AB - Presently marketed vaginal barrier agents are cytotoxic and damage the vaginal
epithelium and natural vaginal flora with frequent use. Novel noncytotoxic agents
are needed to protect women from sexually transmitted diseases. One candidate
compound is a high-molecular-mass form of soluble poly(sodium 4-styrene
sulfonate) (T-PSS). The antimicrobial activity of T-PSS was evaluated in primary
culture systems and in a genital herpes murine model. Results obtained indicate
that T-PSS is highly effective against herpes simplex viruses, Neisseria
gonorrhoeae, and Chlamydia trachomatis in vitro. A 5% T-PSS gel protected 15 of
16 mice from vaginal herpes, compared with 2 of 16 mice treated with a placebo
gel. Moreover, T-PSS exhibited little or no cytotoxicity and has an excellent
selectivity index. T-PSS is an excellent candidate topical antimicrobial that
blocks adherence of herpes simplex virus at low concentrations, inactivates virus
at higher concentrations, and exhibits a broad spectrum of antimicrobial
activity.
PMID- 10669375
TI - Vaccination with FimH adhesin protects cynomolgus monkeys from colonization and
infection by uropathogenic Escherichia coli.
AB - Escherichia coli FimH adhesin mediates binding to the bladder mucosa. In mice, a
FimH vaccine protects against bacterial challenge. In this study, 4 monkeys were
inoculated with 100 microgram of FimCH adhesin-chaperone complex mixed with MF59
adjuvant, and 4 monkeys were given adjuvant only intramuscularly. After 2 doses
(day 0 and week 4), a booster at 48 weeks elicited a strong IgG antibody response
to FimH in the vaccinated monkeys. All 8 monkeys were challenged with 1 mL of 108
E. coli cystitis isolate NU14. Three of the 4 vaccinated monkeys were protected
from bacteruria and pyuria; all control monkeys were infected. These findings
suggest that a vaccine based on the FimH adhesin of E. coli type 1 pili may have
utility in preventing cystitis in humans.
PMID- 10669376
TI - Characterization of enterotoxigenic Escherichia coli strains in patients with
travelers' diarrhea acquired in Guadalajara, Mexico, 1992-1997.
AB - The relationship between enterotoxigenic Escherichia coli (ETEC) and travelers'
diarrhea was examined in a high-risk area in 1992-1997. Toxin patterns,
colonization-factor antigens (CFAs), and in vitro antimicrobial susceptibility
were determined. In total, 928 US students with diarrhea acquired in Guadalajara,
Mexico, were screened for enteric pathogens. Diagnosis of ETEC infection was done
with oligonucleotide probes. ETEC was isolated in 19.9% of the travelers with
diarrhea. CFAs were identified in 51% of the ETEC strains. The highest CFA
frequency was observed among heat-stable isolates. Ampicillin, furazolidone, and
sulfisoxazole resistance of ETEC increased during the study period. ETEC
isolation rates and CFA patterns varied little during the 6 years of the study,
which has implications for immunoprophylactic strategies. The finding that
differences in the results of ribotyping and plasmid analysis change over time
suggests that multiple strains of ETEC were responsible for the illness in the
region studied.
PMID- 10669377
TI - Inflammatory cytokine mRNA expression during early and persistent Helicobacter
pylori infection in nonhuman primates.
AB - The role of mononuclear phagocytes in orchestrating the host responses to
Helicobacter pylori is inadequately understood. Therefore, gene expression for
the monocyte/macrophage-derived cytokines interleukin (IL)-1beta, IL-6, and tumor
necrosis factor (TNF)-alpha was determined before and during H. pylori infection
of rhesus monkeys by use of a highly sensitive quantitative reverse transcriptase
polymerase chain reaction. The numbers of molecules of IL-1beta, IL-6, and TNF
alpha mRNA in gastric tissue during early infection (7 weeks) significantly
exceeded the preinfection numbers (P<.03). Moreover, the numbers of IL-1beta, IL
6, and TNF-alpha mRNA molecules in persistently infected animals (6 years) also
were elevated compared with preinfection numbers (P<.02, P=.03, P=.16,
respectively). Cytokine gene expression coincided with progressive H. pylori
gastritis, confirmed by increased gastritis scores over preinfection scores
(P<.005). These findings provide quantitative evidence that H. pylori induces
local gene expression of monocyte/macrophage-derived inflammatory cytokines and
evokes an innate response in gastric tissue of nonhuman primates.
PMID- 10669378
TI - Chlamydia pneumoniae-induced transactivation of the major immediate early
promoter of cytomegalovirus: potential synergy of infectious agents in the
pathogenesis of atherosclerosis.
AB - Both cytomegalovirus (CMV) and Chlamydia pneumoniae have been associated with
atherosclerosis. CMV is believed to exist in host tissues in a latent state with
periodic reactivation. This study was designed to determine whether C. pneumoniae
infection stimulates the expression of CMV genes. Transactivation of the CMV
major immediate early promoter (MIEP) is essential for viral gene expression and
viral replication. HeLa cells were transfected with a construct containing a
reporter gene (chloramphenicol acetyl transferase) controlled by the MIEP. The
cells were then infected with Chlamydia at 102-106 infection-forming units (IFU)
per well at various times before assay of MIEP activity (72 h after
transfection). Peak transactivation occurred 6 h after infection at 104 IFU. C.
pneumoniae increased MIEP activity in a dose-response manner; maximal increase
was >2-fold. These results suggest that if CMV and C. pneumoniae do indeed
contribute to atherosclerosis, their copresence may synergistically contribute to
it.
PMID- 10669379
TI - Stimulation of macrophage inflammatory protein-1alpha, macrophage inflammatory
protein-1beta, and RANTES by Candida albicans and Cryptococcus neoformans in
peripheral blood mononuclear cells from persons with and without human
immunodeficiency virus infection.
AB - The beta-chemokine macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and
RANTES are critical for recruitment of inflammatory cells into infected tissue.
Moreover, by binding to the human immunodeficiency virus (HIV) coreceptor CCR5,
release of these chemokines could influence the course of HIV infection. beta
chemokine gene expression and release was determined by ELISA and RNase
protection assay, respectively, in peripheral blood mononuclear cells (PBMC) from
HIV-negative and -positive persons stimulated with Candida albicans and
Cryptococcus neoformans, 2 fungi common in HIV-infected persons. Gene expression
and/or release of all 3 chemokines was seen in response to both fungi although C.
albicans was more potent than C. neoformans. Fungal stimulated chemokine
production by HIV-positive PBMC was similar to that in HIV-negative PBMC,
suggesting that the scant inflammatory response often seen in AIDS patients with
cryptococcosis and candidiasis is not secondary to suboptimal beta-chemokine
release.
PMID- 10669380
TI - Visceral leishmanicidal activity of hexadecylphosphocholine (miltefosine) in mice
deficient in T cells and activated macrophage microbicidal mechanisms.
AB - Hexadecylphosphocholine (miltefosine), a membrane-active alkylphospholipid, may
be the first effective oral agent for visceral leishmaniasis, an intracellular
protozoal infection of tissue macrophages. In vitro, miltefosine stimulates T
cells and macrophages to respond to and secrete activating cytokines, including
interferon (IFN)-gamma, and enhances macrophage production of microbicidal
reactive nitrogen and oxygen intermediates (RNIs and ROIs, respectively). To
determine whether these effects mediate miltefosine's in vivo leishmanicidal
efficacy, genetically deficient mice were infected with Leishmania donovani.
Intracellular visceral killing was retained in mice lacking or deficient in T
cells, endogenous IFN-gamma, and macrophage generation of leishmanicidal RNIs and
ROIs. Although mutant mice responded to miltefosine in the absence of tissue
granulomas, treatment enhanced granuloma assembly in normal animals. These
results suggest that miltefosine's visceral leishmanicidal effect does not
require host T cell-dependent or activated macrophage-mediated mechanisms; thus,
this agent may potentially be useful in treating T cell-deficient patients with
kala-azar.
PMID- 10669382
TI - Reply.
PMID- 10669381
TI - Mastitis and human immunodeficiency virus transmission: chemokines and maternal
monocytes.
PMID- 10669383
TI - Preliminary falsification of EIA screening is cost-effective in the two-step
serodiagnosis of lyme disease.
PMID- 10669385
TI - Reply.
PMID- 10669384
TI - TT virus: evidence for transplacental transmission.
PMID- 10669386
TI - Neglected opportunities.
PMID- 10669388
TI - Reply.
PMID- 10669387
TI - Helicobacter pylori, lifestyle risk factors, and adenocarcinoma of the esophagus.
PMID- 10669389
TI - Reemergence of invasive Haemophilus influenzae type b disease in Alaska: Is it
because of vaccination with polyribosylribitol phosphate outer membrane protein
complex (PRP-OMPC) or failure to vaccinate with PRP-OMPC?
PMID- 10669390
TI - Reply.
PMID- 10669391
TI - Mortality in serologically unconfirmed Mediterranean spotted fever.
PMID- 10669392
TI - Reply.
PMID- 10669393
TI - Oropharyngeal Candida colonization and human immunodeficiency virus type 1
infection.
PMID- 10669394
TI - Reply.
PMID- 10669396
TI - Bioconversion of D-galactose into D-tagatose by expression of L-arabinose
isomerase.
AB - D-Tagatose is a potential bulking agent in food as a non-calorific sweetener. To
produce D-tagatose from cheaper resources, plasmids harbouring the L-arabinose
isomerase gene (araA) from Escherichia coli, Bacillus subtilis and Salmonella
typhimurium were constructed because L-arabinose isomerase was suggested
previously as an enzyme that mediates the bioconversion of galactose into
tagatose as well as that of arabinose to ribulose. The constructed plasmids were
named pTC101, pTC105 and pTC106, containing araA from E. coli, B. subtilis and S.
typhimurium respectively. In the cultures of recombinant E. coli with pTC101,
pTC105 and pTC106, tagatose was produced from galactose in 9.9, 7.1 and 6.9%
yields respectively. The enzyme extract of E. coli with the plasmid pTC101 also
converted galactose into tagatose with a 96.4% yield.
PMID- 10669397
TI - Characterization of N-linked oligosaccharides bearing sialyl lewis x moieties on
an alternatively glycosylated form of soluble complement receptor type 1 (sCR1).
AB - We sought to produce a complement inhibitory protein possessing oligosaccharides
specifically modified to contain the sialyl Lewis x (sLe(x)) moiety. This
modified glycoprotein could combine anti-complement activity with the ability to
inhibit selectin-mediated interactions and concentrate this activity to sites of
activated endothelium where selectins are upregulated. Soluble complement
receptor type 1 (sCR1), previously shown to be effective in inhibiting the
complement cascade, was produced in a cell line capable of adding fucose to N
linked oligosaccharides in the alpha1-3 linkage, which is necessary for sLe(x)
glycosylation. The glycoprotein purified from these cells was designated
sCR1sLe(x), and may prove to be more effective than sCR1 in some clinical
applications. Detailed analysis and characterization of sCR1sLe(x) was performed
to confirm that the N-linked oligosaccharides possessed sLe(x) moieties and also
to determine the extent of sLe(x) glycosylation. The glycoproteins were
characterized by oligosaccharide profiling, sequencing, linkage analysis and
quantified by differential enzymic digestion, using fluorophore-assisted
carbohydrate electrophoresis. The major glycans were identified as biantennary
oligosaccharides (including sialylated and non-core fucosylated glycans). The
linkages of sialic acid and the branched fucose were analysed by digestion with
linkage-specific enzymes and subsequent separation by electrophoresis. All data
were consistent with the presence of sLe(x) moieties on the N-linked
oligosaccharides of sCR1sLe(x). sCR1sLe(x) is a prime example of a recombinant
protein expressed with oligosaccharides engineered for a specific biological
function, and produced using a commercially viable method.
PMID- 10669398
TI - Affinity adsorbents for the vancomycin group of antibiotics.
AB - The vancomycin group of antibiotics kill Gram-positive bacteria by binding to
nascent bacterial cell-wall peptidoglycan bearing the C-terminal sequence-D-Ala-D
Ala. In this paper, affinity adsorbents for the vancomycin group of antibiotics
were prepared by immobilizing the peptidoglycan analogues -D-Ala-D-Ala, -succinyl
D-Ala and -succinyl-Gly on to crosslinked poly(N, N-dimethylacrylamide). The
adsorption capacities of the three adsorbents for demethylvancomycin were 0.59,
0.35 and 0.29 mmol/g, respectively. The adsorption capacity of the adsorbent with
D-Ala-D-Ala for vancomycin was 0.53 mmol/g. In contrast, the adsorbent bearing
succinyl-L-Ala hardly adsorbed demethylvancomycin. Aqueous sodium carbonate (0.4
M)/acetonitrile (7/3, v/v) completely desorbed demethylvancomycin adsorbed on the
adsorbents.
PMID- 10669399
TI - Selecting and expressing protective single-chain Fv fragment to stabilize L
asparaginase against inactivation by trypsin.
AB - Four non-inhibitory specific single-chain Fv (sc Fv) fragments directed against L
asparaginase (ASNase) of Escherichia coli were selected from a synthetic phage
display scFv library. The scFv46 fragment could enhance the resistance of ASNase
to trypsin proteolysis, with 70% of the initial ASNase activity present after the
ASNase-scFv46 complex had been treated with trypsin for 30 min at 37 degrees C,
whereas little residual activity was detected without the scFv46 fragment. The
scFv46 gene was cloned to an expression vector pET-21a and expressed at high
levels (about 45% of total cell protein) in E. coli BL21 (DE3) as inclusion
bodies. The refolded and purified scFv46 fragment was proved to protect ASNase,
and the protective effect was further confirmed by SDS/PAGE. It was found that
under optimum conditions of molar ratio of scFv to ASNase, incubation time and
temperature, the residual activity of the ASNase-scFv46 complex could reach about
78% after treatment with trypsin for 30 min at 37 degrees C. The results
demonstrated that scFv fragments prepared by phage-antibody library technology
could be used to protect target proteins.
PMID- 10669400
TI - Conformational issues in the characterization of proteins.
AB - The conformation of a protein refers to the three-dimensional arrangement of its
constituent atoms. Since expression of the biological activity of a protein
depends on its conformation, it is clear that full characterization of a protein
involves an understanding of its three-dimensional structure. This review
outlines the principal techniques for determining the conformation of a protein,
describes the crucial role played by the flexibility of proteins, and gives an
account of current theories of the mechanisms by which proteins fold. A final
section deals with strategies that can be adopted to preserve the conformational
integrity of proteins; an aspect that is of increasing importance as a greater
number of proteins are finding applications in industrial processes and as
therapeutic and diagnostic agents.
PMID- 10669401
TI - Relationship between conformational stability and lyophilization-induced
structural changes in chymotrypsin.
AB - The relationship between protein conformational stability in aqueous solution and
the magnitude of lyophilization-induced structural changes was investigated
employing alpha- and gamma-chymotrypsin. As a measure of the conformational
stability the melting temperature T(m) was determined in distilled water at
various pH values. The proteins were then lyophilized from those pH values where
the conformational stability was maximum (pH 4.5) and minimum (pH 7.8). Protein
secondary structure was quantitatively determined utilizing Fourier-transform
infrared spectroscopy employing two regions sensitive to protein structure, the
amide-I (1600-1700 cm(-1)) and amide-III (1215-1335 cm(-1)). Lyophilization
induced significant structural alterations in both proteins, characterized by a
slight decrease in the alpha-helix and a significant increase in the beta-sheet
content. However, regardless of the pH from which the proteins were lyophilized,
the secondary structures in the solid state were indistinguishable. This result
shows that there is no relationship between the conformational stability in
aqueous solution and the magnitude of lyophilization-induced structural changes.
We also investigated whether lyoprotectants could minimize lyophilization-induced
structural changes by increasing protein conformational stability in aqueous
solution. After having identified trehalose as being efficient in largely
preventing lyophilization-induced structural alterations, we conducted co
lyophilization experiments from various pH values. The results obtained exclude
any contribution from increased protein conformational stability caused by the
additive in aqueous solution to the beneficial structural preservation upon
lyophilization. This can be understood because the dehydration and not the
freezing process, as shown in an air-drying experiment, mainly causes protein
structural alterations.
PMID- 10669402
TI - Efficient utilization of starch by a recombinant strain of Saccharomyces
cerevisiae producing glucoamylase and isoamylase.
AB - Two plasmids, designated pRTI and pTI, were constructed to allow the integration
of a bacterial isoamylase gene (iso) into Saccharomyces cerevisiae G23-8
chromosome. The integrative plasmid pRTI comprises the iso gene from Pseudomonas
amyloderamosa, a portion of S. cerevisiae ribosomal DNA (rDNA), S. cerevisiae
trp1 gene deficient in promoter and the bacterial vector pSP72. The structure of
plasmid pTI is similar to that of pRTI, except that it lacks an rDNA segment. The
Aspergillus awamori glucoamylase and P. amyloderamosa isoamylase genes were
expressed in the recombinant strain of S. cerevisiae under the control of the
yeast alcohol dehydrogenase gene (adh1) promoter. Southern-blot analysis showed
that these plasmids were integrated into the yeast chromosome in tandem repeat
and dispersion copies. The recombinant strains could assimilate starch more
efficiently than the recipient strain with a conversion rate of greater than 95%.
PMID- 10669403
TI - Endoxylanase II from Trichoderma reesei has several isoforms with different
isoelectric points.
AB - Two minor xylanases present in Trichoderma reesei Rut C30 cultivation broth were
purified as a mixture using ion-exchange, hydrophobic-interaction and gel
chromatography. The purified enzyme preparation contained two active xylanases
with pI values of 7.1 and 8.1. Both components had a molecular mass of 20 kDa.
The purified xylanase preparation exhibited properties very similar to those of
the previously isolated XYL II (pI 9.0) of T. reesei Rut C30. The activity and
stability properties, apparent kinetic parameters as well as the titration curve
forms were similar. The major difference in enzymic properties was the
significantly lower specific activity of the pI-7.1+8.1 xylanase mixture (3350
nkat/mg) compared with the specific activity of XYL II (13500 nkat/mg). Amino
acid sequences of tryptic peptides (34% of the total amino acid sequence was
determined) were identical to the amino acid sequence of XYL II. Furthermore, in
vitro modification of the pI-9.0 form of XYL II to pI-8.1 and pI-7.1 forms was
demonstrated. Thus the purified xylanase preparation most probably contained two
modified forms of XYL II. The primary amino acid sequence of XYL II contains 28
glutamine and asparagine residues and theoretically deamination of one of them
lowers the pI to 8.06 and deamination of two amino acids lowers the pI to 7.02.
PMID- 10669404
TI - Conformational issues in the characterization of proteins.
PMID- 10669405
TI - Phase-specific optimization of multiple endotoxin-protein production with
genetically engineered Bacillus thuringiensis.
AB - An optimization approach was designed to specifically study the toxin-expression
phase of the fermentation process of a genetically engineered Bacillus
thuringiensis strain expressing dual toxin proteins (CryI and CryIII). The study
has resulted in the discovery of important nutrient and process factors affecting
toxin-protein yield. The results show that the existence of nitrogen sources in
the medium during the toxin-expression phase is detrimental to the toxin-protein
expression, while a high carbon-source level (40 g/l) encouraged protein
expression. The study also suggests that the depletion of nitrogen source is the
trigger for B. thuringiensis to initiate sporulation and toxin expression. A
temperature setting of 28 degrees C for B. thuringiensis fermentation processes
is optimal for protein yield, and reduces the oxygen requirement. It was found
that the optimal conditions for spore yield and for toxin-protein yield were not
the same, even though sporulation and toxin formation proceed simultaneously
during the fermentation process. Scale-up studies were also conducted to confirm
the optimal conditions obtained from a small-scale optimization study.
PMID- 10669406
TI - Quantization of multiparticle auger rates in semiconductor quantum dots
AB - We have resolved single-exponential relaxation dynamics of the 2-, 3-, and 4
electron-hole pair states in nearly monodisperse cadmium selenide quantum dots
with radii ranging from 1 to 4 nanometers. Comparison of the discrete relaxation
constants measured for different multiple-pair states indicates that the carrier
decay rate is cubic in carrier concentration, which is characteristic of an Auger
process. We observe that in the quantum-confined regime, the Auger constant is
strongly size-dependent and decreases with decreasing the quantum dot size as the
radius cubed.
PMID- 10669407
TI - Observation of antiferromagnetic domains in epitaxial thin films
AB - Antiferromagnetic domains in an epitaxial thin film, LaFeO(3) on SrTiO(3)(100),
were observed using a high-spatial-resolution photoelectron emission microscope
with contrast generated by the large x-ray magnetic linear dichroism effect at
the multiplet-split L edge of Fe. The antiferromagnetic domains are linked to 90
degrees twinned crystallographic regions in the film. The Neel temperature of the
thin film is reduced by 70 kelvin relative to the bulk material, and this
reduction is attributed to epitaxial strain. These studies open the door for a
microscopic understanding of the magnetic coupling across antiferromagnetic
ferromagnetic interfaces.
PMID- 10669408
TI - Molecules in a bose-einstein condensate
AB - State-selected rubidium-87 molecules were created at rest in a dilute Bose
Einstein condensate of rubidium-87 atoms with coherent free-bound stimulated
Raman transitions. The transition rate exhibited a resonance line shape with an
extremely narrow width as small as 1.5 kilohertz. The precise shape and position
of the resonance are sensitive to the mean-field interactions between the
molecules and the atomic condensate. As a result, we were able to measure the
molecule-condensate interactions. This method allows molecular binding energies
to be determined with unprecedented accuracy and is of interest as a mechanism
for the generation of a molecular Bose-Einstein condensate.
PMID- 10669409
TI - Zener model description of ferromagnetism in zinc-blende magnetic semiconductors
AB - Ferromagnetism in manganese compound semiconductors not only opens prospects for
tailoring magnetic and spin-related phenomena in semiconductors with a precision
specific to III-V compounds but also addresses a question about the origin of the
magnetic interactions that lead to a Curie temperature (T(C)) as high as 110 K
for a manganese concentration of just 5%. Zener's model of ferromagnetism,
originally proposed for transition metals in 1950, can explain T(C) of Ga(1
)(x)Mn(x)As and that of its II-VI counterpart Zn(1-)(x)Mn(x)Te and is used to
predict materials with T(C) exceeding room temperature, an important step toward
semiconductor electronics that use both charge and spin.
PMID- 10669410
TI - Ambipolar pentacene field-effect transistors and inverters.
AB - Organic field-effect transistors based on pentacene single crystals, prepared
with an amorphous aluminum oxide gate insulator, are capable of ambipolar
operation and can be used for the preparation of complementary inverter circuits.
The field-effect mobilities of carriers in these transistors increase from 2.7
and 1.7 square centimeters per volt per second at room temperature up to 1200 and
320 square centimeters per volt per second at low temperatures for hole and
electron transport, respectively, following a power-law dependence. The possible
simplification of the fabrication process of complementary logic circuits with
these transistors, together with the high carrier mobilities, may be seen as
another step toward applications of plastic electronics.
PMID- 10669411
TI - CsBi(4)Te(6): A high-performance thermoelectric material for low-temperature
applications
AB - Thermoelectric (Peltier) heat pumps are capable of refrigerating solid or fluid
objects, and unlike conventional vapor compressor systems, they can be
miniaturized without loss of efficiency. More efficient thermoelectric materials
need to be identified, especially for low-temperature applications in electronics
and devices. The material CsBi(4)Te(6) has been synthesized and its properties
have been studied. When doped appropriately, it exhibits a high thermoelectric
figure of merit below room temperature (ZT(max) approximately 0.8 at 225 kelvin).
At cryogenic temperatures, the thermoelectric properties of CsBi(4)Te(6) appear
to match or exceed those of Bi(2-x)Sb(x)Te(3-y)Se(y) alloys.
PMID- 10669412
TI - Physics of iron at Earth's core conditions
AB - The bulk properties of iron at the pressure and temperature conditions of Earth's
core were determined by a method that combines first-principles and classical
molecular dynamic simulations. The theory indicates that (i) the iron melting
temperature at inner-core boundary (ICB) pressure (330 gigapascals) is 5400 (+/
400) kelvin; (ii) liquid iron at ICB conditions is about 6% denser than Earth's
outer core; and (iii) the shear modulus of solid iron close to its melting line
is 140 gigapascals, consistent with the seismic value for the inner core. These
results reconcile melting temperature estimates based on sound velocity shock
wave data with those based on diamond anvil cell experiments.
PMID- 10669413
TI - Surface expression of HLA-E, an inhibitor of natural killer cells, enhanced by
human cytomegalovirus gpUL40.
AB - The nonclassical major histocompatibility complex (MHC) class I molecule HLA-E
inhibits natural killer (NK) cell-mediated lysis by interacting with CD94/NKG2A
receptors. Surface expression of HLA-E depends on binding of conserved peptides
derived from MHC class I molecules. The same peptide is present in the leader
sequence of the human cytomegalovirus (HCMV) glycoprotein UL40 (gpUL40). It is
shown that, independently of the transporter associated with antigen processing,
gpUL40 can up-regulate expression of HLA-E, which protects targets from NK cell
lysis. While classical MHC class I molecules are down-regulated, HLA-E is up
regulated by HCMV. Induction of HLA-E surface expression by gpUL40 may represent
an escape route for HCMV.
PMID- 10669414
TI - Localization of the G protein betagamma complex in living cells during
chemotaxis.
AB - Gradients of chemoattractants elicit signaling events at the leading edge of a
cell even though chemoattractant receptors are uniformly distributed on the cell
surface. In highly polarized Dictyostelium discoideum amoebas, membrane
associated betagamma subunits of heterotrimeric guanine nucleotide-binding
proteins (G proteins) were localized in a shallow anterior-posterior gradient. A
uniformly applied chemoattractant generated binding sites for pleckstrin homology
(PH) domains on the inner surface of the membrane in a pattern similar to that of
the Gbetagamma subunits. Loss of cell polarity resulted in uniform distribution
of both the Gbetagamma subunits and the sensitivity of PH domain recruitment.
These observations indicate that Gbetagamma subunits are not sufficiently
localized to restrict signaling events to the leading edge but that their
distribution may determine the relative chemotactic sensitivity of polarized
cells.
PMID- 10669415
TI - Polarization of chemoattractant receptor signaling during neutrophil chemotaxis.
AB - Morphologic polarity is necessary for chemotaxis of mammalian cells. As a probe
of intracellular signals responsible for this asymmetry, the pleckstrin homology
domain of the AKT protein kinase (or protein kinase B), tagged with the green
fluorescent protein (PHAKT-GFP), was expressed in neutrophils. Upon exposure of
cells to chemoattractant, PHAKT-GFP is recruited selectively to membrane at the
cell's leading edge, indicating an internal signaling gradient that is much
steeper than that of the chemoattractant. Translocation of PHAKT-GFP is inhibited
by toxin-B from Clostridium difficile, indicating that it requires activity of
one or more Rho guanosine triphosphatases.
PMID- 10669416
TI - Function of PI3Kgamma in thymocyte development, T cell activation, and neutrophil
migration.
AB - Phosphoinositide 3-kinases (PI3Ks) regulate fundamental cellular responses such
as proliferation, apoptosis, cell motility, and adhesion. Viable gene-targeted
mice lacking the p110 catalytic subunit of PI3Kgamma were generated. We show that
PI3Kgamma controls thymocyte survival and activation of mature T cells but has no
role in the development or function of B cells. PI3Kgamma-deficient neutrophils
exhibited severe defects in migration and respiratory burst in response to
heterotrimeric GTP-binding protein (G protein)-coupled receptor (GPCR) agonists
and chemotactic agents. PI3Kgamma links GPCR stimulation to the formation of
phosphatidylinositol 3,4,5-triphosphate and the activation of protein kinase B,
ribosomal protein S6 kinase, and extracellular signal-regulated kinases 1 and 2.
Thus, PI3Kgamma regulates thymocyte development, T cell activation, neutrophil
migration, and the oxidative burst.
PMID- 10669418
TI - Central role for G protein-coupled phosphoinositide 3-kinase gamma in
inflammation.
AB - Phosphoinositide 3-kinase (PI3K) activity is crucial for leukocyte function, but
the roles of the four receptor-activated isoforms are unclear. Mice lacking
heterotrimeric guanine nucleotide-binding protein (G protein)-coupled PI3Kgamma
were viable and had fully differentiated neutrophils and macrophages.
Chemoattractant-stimulated PI3Kgamma-/- neutrophils did not produce
phosphatidylinositol 3,4,5-trisphosphate, did not activate protein kinase B, and
displayed impaired respiratory burst and motility. Peritoneal PI3Kgamma-null
macrophages showed a reduced migration toward a wide range of chemotactic stimuli
and a severely defective accumulation in a septic peritonitis model. These
results demonstrate that PI3Kgamma is a crucial signaling molecule required for
macrophage accumulation in inflammation.
PMID- 10669417
TI - Roles of PLC-beta2 and -beta3 and PI3Kgamma in chemoattractant-mediated signal
transduction.
AB - The roles of phosphoinositide 3-kinase (PI3K) and phospholipase C (PLC) in
chemoattractant-elicited responses were studied in mice lacking these key
enzymes. PI3Kgamma was required for chemoattractant-induced production of
phosphatidylinositol 3,4,5-trisphosphate [PtdIns (3,4,5)P3] and has an important
role in chemoattractant-induced superoxide production and chemotaxis in mouse
neutrophils and in production of T cell-independent antigen-specific antibodies
composed of the immunoglobulin lambda light chain (TI-IglambdaL). The study of
the mice lacking PLC-beta2 and -beta3 revealed that the PLC pathways have an
important role in chemoattractant-mediated production of superoxide and
regulation of protein kinases, but not chemotaxis. The PLC pathways also appear
to inhibit the chemotactic activity induced by certain chemoattractants and to
suppress TI-IglambdaL production.
PMID- 10669419
TI - Requirement for DARPP-32 in progesterone-facilitated sexual receptivity in female
rats and mice.
AB - DARPP-32, a dopamine- and adenosine 3',5'-monophosphate (cAMP)-regulated
phosphoprotein (32 kilodaltons in size), is an obligate intermediate in
progesterone (P)-facilitated sexual receptivity in female rats and mice. The
facilitative effect of P on sexual receptivity in female rats was blocked by
antisense oligonucleotides to DARPP-32. Homozygous mice carrying a null mutation
for the DARPP-32 gene exhibited minimal levels of P-facilitated sexual
receptivity when compared to their wild-type littermates. P significantly
increased hypothalamic cAMP levels and cAMP-dependent protein kinase activity.
These increases were not inhibited by a D1 subclass dopamine receptor antagonist.
P also enhanced phosphorylation of DARPP-32 on threonine 34 in the hypothalamus
of mice. DARPP-32 activation is thus an obligatory step in progestin receptor
regulation of sexual receptivity in rats and mice.
PMID- 10669420
TI - Ethanol-induced apoptotic neurodegeneration and fetal alcohol syndrome.
AB - The deleterious effects of ethanol on the developing human brain are poorly
understood. Here it is reported that ethanol, acting by a dual mechanism
[blockade of N-methyl-D-aspartate (NMDA) glutamate receptors and excessive
activation of GABA(A) receptors], triggers widespread apoptotic neurodegeneration
in the developing rat forebrain. Vulnerability coincides with the period of
synaptogenesis, which in humans extends from the sixth month of gestation to
several years after birth. During this period, transient ethanol exposure can
delete millions of neurons from the developing brain. This can explain the
reduced brain mass and neurobehavioral disturbances associated with human fetal
alcohol syndrome.
PMID- 10669421
TI - Evidence for DNA loss as a determinant of genome size.
AB - Eukaryotic genome sizes range over five orders of magnitude. This variation
cannot be explained by differences in organismic complexity (the C value
paradox). To test the hypothesis that some variation in genome size can be
attributed to differences in the patterns of insertion and deletion (indel)
mutations among organisms, this study examines the indel spectrum in Laupala
crickets, which have a genome size 11 times larger than that of Drosophila.
Consistent with the hypothesis, DNA loss is more than 40 times slower in Laupala
than in Drosophila.
PMID- 10669423
TI - Nicotine addiction.
PMID- 10669422
TI - Conservation and novelty in the evolution of cell adhesion and extracellular
matrix genes.
AB - New proteins and modules have been invented throughout evolution. Gene "birth
dates" in Caenorhabditis elegans range from the origins of cellular life through
adaptation to a soil habitat. Possibly half are "metazoan" genes, having arisen
sometime between the yeast-metazoan and nematode-chordate separations. These
include basement membrane and cell adhesion molecules implicated in tissue
organization. By contrast, epithelial surfaces facing the environment have
specialized components invented within the nematode lineage. Moreover,
interstitial matrices were likely elaborated within the vertebrate lineage. A
strategy for concerted evolution of new gene families, as well as conservation of
adaptive genes, may underlie the differences between heterochromatin and
euchromatin.
PMID- 10669424
TI - Voluntary organisations: from Cinderella to white knight?
PMID- 10669425
TI - From CME to CPD: getting better at getting better?
PMID- 10669426
TI - Should doctors get CME points for reading?
PMID- 10669427
TI - The changing face of refractive surgery.
PMID- 10669428
TI - Doctors told to treat nicotine addiction as a disease.
PMID- 10669429
TI - Video guide to suicide is shown on television.
PMID- 10669431
TI - In brief
PMID- 10669430
TI - Breast cancer researcher accused of serious scientific misconduct.
PMID- 10669432
TI - Neurosurgical units working beyond safe capacity.
PMID- 10669433
TI - Solicitor in litigation case condemns tobacco industry.
PMID- 10669434
TI - Oral sex may be important risk factor for HIV infection.
PMID- 10669435
TI - Canada faces healthcare crisis
PMID- 10669436
TI - Medical research site in Berlin threatened.
PMID- 10669437
TI - Convalescent homes to make a comeback.
PMID- 10669438
TI - Milburn sets up inquiry into Shipman case.
PMID- 10669439
TI - BMA accused of contempt of court.
PMID- 10669440
TI - WHO study examines teenage health in 28 countries.
PMID- 10669441
TI - Radiation of the arteries can reduce narrowing
PMID- 10669442
TI - UK launches initiative on global health
PMID- 10669443
TI - Prospective investigation of transfusion transmitted infection in recipients of
over 20 000 units of blood. TTI Study Group.
AB - OBJECTIVES: To follow up recipients of 20 000 units of blood to identify any
transmissions of infections through blood transfusion. DESIGN: Follow up study of
recipients of transfusion. SETTING: 22 hospitals in north London. PARTICIPANT:
Adult patients who had recently been transfused. MAIN OUTCOME MEASURES: Patients
had further blood samples taken at 9 months that were tested for markers of
hepatitis B and C and HIV and human T cell leukaemia/lymphoma virus type I or II
(HTLV) infections. Recent infections were distinguished from pre-existing
infections by comparison with blood samples taken before transfusion. RESULTS:
9220 patients were recruited, and 5579 recipients of 21 923 units of blood were
followed up. No transfusion transmitted infections were identified. The incidence
of transfusion transmitted infections was 0 in 21 043 units (95% confidence
interval for risk 0 to 1 in 5706 recipients) for hepatitis B; 0 in 21 800 units
(0 to 1 in 5911 recipients) for hepatitis C; 0 in 21 923 units (0 to 1 in 5944
recipients) for HIV; and 0 in 21 902 units (0 to 1 in 5939 recipients) for human
T cell leukaemia/lymphoma virus. Three patients acquired hepatitis B during or
after hospital admission but not through transfusion; 176 (3%) had pre-existing
hepatitis B infection. Sixteen (0.29%) patients had hepatitis C, and five (0.09%)
had human T cell leukaemia/lymphoma virus. CONCLUSIONS: The current risk of
transfusion transmitted infections in the United Kingdom is very small, though
hospital acquired infections may arise from sources other than transfusion. A
considerable proportion of patients have pre-existing infections.
PMID- 10669444
TI - Psychological consequences for parents of false negative results on prenatal
screening for Down's syndrome: retrospective interview study.
AB - OBJECTIVE: To determine the psychological consequences for parents of children
with Down's syndrome of having received a false negative result on prenatal
screening. DESIGN: Comparison of adjustment of parents who received a false
negative result with that of parents not offered a test and those who declined a
test. SETTING: Parents were interviewed in their own homes. PARTICIPANTS: Parents
of 179 children with Down's syndrome (mean age 4 (range 2-6) years). MAIN OUTCOME
MEASURES: Anxiety, depression, parenting stress, attitudes towards the child, and
attributions of blame for the birth of the affected child. RESULTS: Overall,
regardless of screening history, parents adjusted well to having a child with
Down's syndrome. Compared with mothers who declined a test, mothers in the false
negative group had higher parenting stress (mean score 81.2 v 71.8, P=0.016, 95%
confidence interval for the difference 1.8 to 17.0) and more negative attitudes
towards their children (124.9 v 134.2, P=0. 009, -16.2 to -2.4). Fathers in the
false negative group had higher parenting stress test scores (77.8 v 70.0,
P=0.046, 1.5 to 14.2) than fathers not offered a test. Mothers in the false
negative group were more likely to blame others for the outcome than mothers who
had not been offered the test (28% v 13%, P=0.032, 3% to 27%). Mothers and
fathers in the false negative group were more likely to blame others for this
outcome than parents who had declined a test (mothers 28% v 0%, P=0.001, 19% to
37%; fathers 27% v 0%, P=0.004, 17% to 38%). Blaming others was associated with
poorer adjustment for mothers and fathers. CONCLUSIONS: A false negative result
on prenatal screening seems to have a small adverse effect on parental adjustment
evident two to six years after the birth of an affected child.
PMID- 10669445
TI - Exposure to foodborne and orofecal microbes versus airborne viruses in relation
to atopy and allergic asthma: epidemiological study.
AB - OBJECTIVE: To investigate if markers of exposure to foodborne and orofecal
microbes versus airborne viruses are associated with atopy and respiratory
allergies. DESIGN: Retrospective case-control study. PARTICIPANTS: 240 atopic
cases and 240 non-atopic controls from a population sample of 1659 participants,
all Italian male cadets aged 17-24. SETTING: Air force school in Caserta, Italy.
MAIN OUTCOME MEASURES: Serology for Toxoplasma gondii, Helicobacter pylori,
hepatitis A virus, measles, mumps, rubella, chickenpox, cytomegalovirus, and
herpes simplex virus type 1; skin sensitisation and IgE antibodies to relevant
airborne allergens; total IgE concentration; and diagnosis of allergic asthma or
rhinitis. RESULTS: Compared with controls there was a lower prevalence of T
gondii (26% v 18%, P=0.027), hepatitis A virus (30% v 16%, P=0.004), and H pylori
(18% v 15%, P=0.325) in atopic participants. Adjusted odds ratios of atopy
decreased with a gradient of exposure to H pylori, T gondii, and hepatitis A
virus (none, odds ratio 1; one, 0. 70; two or three, 0.37; P for trend=0.000045)
but not with cumulative exposure to the other viruses. Conversely, total IgE
concentration was not independently associated with any infection. Allergic
asthma was rare (1/245, 0.4%) and allergic rhinitis infrequent (16/245, 7%) among
the participants (245/1659) exposed to at least two orofecal and foodborne
infections (H pylori, T gondii, hepatitis A virus). CONCLUSION: Respiratory
allergy is less frequent in people heavily exposed to orofecal and foodborne
microbes. Hygiene and a westernised, semisterile diet may facilitate atopy by
influencing the overall pattern of commensals and pathogens that stimulate the
gut associated lymphoid tissue thus contributing to the epidemic of allergic
asthma and rhinitis in developed countries.
PMID- 10669446
TI - Reanalysis of epidemiological evidence on lung cancer and passive smoking.
AB - OBJECTIVE: To assess the epidemiological evidence for an increase in the risk of
lung cancer resulting from exposure to environmental tobacco smoke. DESIGN:
Reanalysis of 37 published epidemiological studies previously included in a meta
analysis allowing for the possibility of publication bias. MAIN OUTCOME MEASURE:
Relative risk of lung cancer among female lifelong non-smokers, according to
whether her partner was a current smoker or a lifelong non-smoker. RESULTS: If it
is assumed that all studies that have ever been carried out are included, or that
those selected for review are truly representative of all such studies, then the
estimated excess risk of lung cancer is 24%, as previously reported (95%
confidence interval 13% to 36%, P<0.001). However, a significant correlation
between study outcome and study size suggests the presence of publication bias.
Adjustment for such bias implies that the risk has been overestimated. For
example, if only 60% of studies have been included, the estimate of excess risk
falls from 24% to 15%. CONCLUSION: A modest degree of publication bias leads to a
substantial reduction in the relative risk and to a weaker level of significance,
suggesting that the published estimate of the increased risk of lung cancer
associated with environmental tobacco smoke needs to be interpreted with caution.
PMID- 10669447
TI - A randomised controlled trial and economic evaluation of a referrals facilitator
between primary care and the voluntary sector.
AB - OBJECTIVES: To compare outcome and resource utilisation among patients referred
to the Amalthea Project, a liaison organisation that facilitates contact between
voluntary organisations and patients in primary care, with patients receiving
routine general practitioner care. DESIGN: Randomised controlled trial with
follow up at one and four months. SETTING: 26 general practices in Avon.
PARTICIPANTS: 161 patients identified by their general practitioner as having
psychosocial problems. MAIN OUTCOME MEASURES: Primary outcomes were psychological
wellbeing (assessed with the hospital anxiety and depression scale) and social
support (assessed using the Duke-UNC functional social support questionnaire).
Secondary outcomes were quality of life measures (the Dartmouth COOP/WONCA
functional health assessment charts and the delighted-terrible faces scale), cost
of contacts with the primary healthcare team and Amalthea Project, cost of
prescribing in primary care, and cost of referrals to other agencies, over four
months. RESULTS: The Amalthea group showed significantly greater improvements in
anxiety (average difference between groups after adjustment for baseline -1.9,
95% confidence interval -3.0 to -0.7), other emotional feelings (average adjusted
difference -0.5, -0.8 to -0.2), ability to carry out everyday activities (-0.5,
0.8 to -0.2), feelings about general health (-0.4, -0.7 to -0.1), and quality of
life (-0.5, -0.9 to -0.1). No difference was detected in depression or perceived
social support. The mean cost was significantly greater in the Amalthea arm than
the general practitioner care arm ( pound153 v pound133, P=0. 025). CONCLUSION:
Referral to the Amalthea Project and subsequent contact with the voluntary sector
results in clinically important benefits compared with usual general practitioner
care in managing psychosocial problems, but at a higher cost.
PMID- 10669449
TI - In the line of duty
PMID- 10669448
TI - Regular review: tumour markers in malignancies.
PMID- 10669450
TI - ABC of heart failure. Management: diuretics, ACE inhibitors, and nitrates.
PMID- 10669451
TI - Continuing medical education and continuing professional development:
international comparisons.
PMID- 10669453
TI - Tuberculosis in prisons in countries with high prevalence.
PMID- 10669452
TI - Are generalists still needed in a specialised world? The renaissance of general
surgery.
PMID- 10669454
TI - Human population growth. Rich countries need education on resource conservation.
PMID- 10669455
TI - Registering trials is not enough to counter perceived irrelevance of much
research.
PMID- 10669456
TI - Coping with winter bed crises. Crises do not just happen in winter.
PMID- 10669457
TI - Prospective risk of stillbirth. Study's results are flawed by reliance on
cumulative prospective risk.
PMID- 10669458
TI - Treatment of venous leg ulcers. Nice study, pity about the sample size.
PMID- 10669459
TI - Stages of change model for smoking prevention and cessation in schools. Authors
applied adult dose for smoking to adolescents when smoking behaviour is different
in the two.
PMID- 10669460
TI - Medicine to serve an ageing society. Retired doctors could have a role.
PMID- 10669461
TI - Removing barriers to career development in public health.
PMID- 10669462
TI - Crinkly toenails. Toenail onychomycosis can cause serious problems.
PMID- 10669463
TI - Obituaries
PMID- 10669464
TI - Many medical chairs remain unfilled
PMID- 10669466
TI - The evolution of british general practice 1850-1948
PMID- 10669465
TI - Cardiovascular medicine: enhanced multimedia CD-ROM
PMID- 10669467
TI - Home sweet Home? the impact of poor housing on health
PMID- 10669468
TI - Exhibiting the mad psychiatrist
PMID- 10669469
TI - The new NHS smoking campaign
PMID- 10669470
TI - Consumers' health
PMID- 10669472
TI - This tablet may save your life
PMID- 10669471
TI - It could be you
PMID- 10669473
TI - How best to learn
PMID- 10669474
TI - Risk of infection from blood transfusion in UK is negligible
PMID- 10669475
TI - False negative result on prenatal Down's screening may damage parental adjustment
PMID- 10669476
TI - Food hygiene and declining orofecal infections may explain the allergy and asthma
epidemic
PMID- 10669477
TI - Lung cancer risk from passive smoking may be overestimated
PMID- 10669478
TI - Voluntary sector input benefits patients with psychosocial problems in primary
care
PMID- 10669479
TI - Improving TB control in prisons may lead to better national programmes
PMID- 10669480
TI - Ocular gaze is anchored to the target of an ongoing pointing movement.
AB - It is well known that, typically, saccadic eye movements precede goal-directed
hand movements to a visual target stimulus. Also pointing in general is more
accurate when the pointing target is gazed at. In this study, it is hypothesized
that saccades are not only preceding pointing but that gaze also is stabilized
during pointing in humans. Subjects, whose eye and pointing movements were
recorded, had to make a hand movement and a saccade to a first target. At arm
movement peak velocity, when the eyes are usually already fixating the first
target, a new target appeared, and subjects had to make a saccade toward it
(dynamical trial type). In the statical trial type, a new target was offered when
pointing was just completed. In a control experiment, a sequence of two saccades
had to be made, with two different interstimulus intervals (ISI), comparable with
the ISIs found in the first experiment for dynamic and static trial types. In a
third experiment, ocular fixation position and pointing target were dissociated,
subjects pointed at not fixated targets. The results showed that latencies of
saccades toward the second target were on average 155 ms longer in the dynamic
trial types, compared with the static trial types. Saccades evoked during
pointing appeared to be delayed with approximately the remaining deceleration
time of the pointing movement, resulting in "normal" residual saccadic reaction
times (RTs), measured from pointing movement offset to saccade movement onset. In
the control experiment, the latency of the second saccade was on average only 29
ms larger when the two targets appeared with a short ISI compared with trials
with long ISIs. Therefore the saccadic refractory period cannot be responsible
for the substantially bigger delays that were found in the first experiment. The
observed saccadic delay during pointing is modulated by the distance between
ocular fixation position and pointing target. The largest delays were found when
the targets coincided, the smallest delays when they were dissociated. In sum,
our results provide evidence for an active saccadic inhibition process,
presumably to keep steady ocular fixation at a pointing target and its
surroundings. Possible neurophysiological substrates that might underlie the
reported phenomena are discussed.
PMID- 10669481
TI - Damping actions of the neuromuscular system with inertial loads: soleus muscle of
the decerebrate cat.
AB - A transient perturbation applied to a limb held in a given posture can induce
oscillations. To restore the initial posture, the neuromuscular system must
provide damping, which is the dissipation of the mechanical energy imparted by
such a perturbation. Despite their importance, damping properties of the
neuromuscular system have been poorly characterized. Accordingly, this paper
describes the damping characteristics of the neuromuscular system interacting
with inertial loads. To quantitatively examine damping, we coupled simulated
inertial loads to surgically isolated, reflexively active soleus muscles in
decerebrate cats. A simulated force impulse was applied to the load, causing a
muscle stretch, which elicited a reflex response. The resulting deviation from
the initial position gave rise to oscillations, which decayed progressively.
Damping provided by the neuromuscular system was then calculated from the load
kinetics. To help interpret our experimental results, we compared our kinetic
measurements with those of an analogous linear viscoelastic system and found that
the experimental damping properties differed in two respects. First, the amount
of damping was greater for large oscillation amplitudes than for small (damping
is independent of amplitude in a linear system). Second, plots of force against
length during the induced movements showed that damping was greater for
shortening than lengthening movements, reflecting greater effective viscosity
during shortening. This again is different from the behavior of a linear system,
in which damping effects would be symmetrical. This asymmetric and nonlinear
damping behavior appears to be related to both the intrinsic nonlinear mechanical
properties of the soleus muscle and to stretch reflex properties. The muscle
nonlinearities include a change in muscle force-generating capacity induced by
forced lengthening, akin to muscle yield, and the nonlinear force-velocity
property of muscle, which is different for lengthening versus shortening. Stretch
reflex responses are also known to be asymmetric and amplitude dependent. The
finding that damping is greater for larger amplitude motion represents a form of
automatic gain adjustment to a larger perturbation. In contrast, because of
reduced damping at small amplitudes, smaller oscillations would tend to persist,
perhaps contributing to normal or "physiological" tremor. This lack of damping
for small amplitudes may represent an acceptable compromise for postural
regulation in that there is substantial damping for larger movements, where
energy dissipation is more critical. Finally, the directional asymmetry in energy
dissipation provided by muscle and reflex properties must be reflected in the
neural mechanisms for a stable posture.
PMID- 10669482
TI - Development of glutamatergic synaptic activity in cultured spinal neurons.
AB - The development of glutamatergic synapses involves a sequence of events that are
still not well understood. We have studied the time course of the development of
glutamatergic synapses in cultured spinal neurons by characterizing spontaneous
synaptic currents recorded from cells maintained in vitro for different times. At
short times in culture (2 days in vitro; DIV2), spontaneous synaptic activity
consisted almost solely of N-methyl-D-aspartate (NMDA) receptor (NMDAR) openings.
In contrast, older neurons (DIV5 to DIV8) displayed clear alpha-amino-3-hydroxy-5
methyl-4-isoxazolepropionic acid (AMPA) receptor (AMPAR)-mediated synaptic
currents, while the NMDAR-mediated activity remained small. Between 8 and 14 days
in vitro there was a large increase in the density of synaptically activated
NMDARs, although there was no significant increase in the density of the NMDAR
mediated current activated by exogenous glutamate. The results indicate that
there is a switch in NMDAR targeting from somatic to synaptic regions during the
course of the second in vitro week. Finally, our results support the conclusion
that the spontaneous synaptic activity displayed in culture depends on ongoing
NMDAR-mediated activity, even when the expression of synaptic NMDARs is low.
PMID- 10669483
TI - Inactivation properties of human recombinant class E calcium channels.
AB - The electrophysiological and pharmacological properties of alpha(1E)-containing
Ca(2+) channels were investigated by using the patch-clamp technique in the whole
cell configuration, in HEK 293 cells stably expressing the human alpha(1E)
together with alpha(2b) and beta(1b) accessory subunits. These channels had
current-voltage (I-V) characteristics resembling those of high-voltage-activated
(HVA) Ca(2+) channels (threshold at -30 mV and peak amplitude at +10 mV in 5 mM
Ca(2+)). The currents activated and deactivated with a fast rate, in a time- and
voltage-dependent manner. No difference was found in their relative permeability
to Ca(2+) and Ba(2+). Inorganic Ca(2+) channel blockers (Cd(2+), Ni(2+)) blocked
completely and potently the alpha(1E,)/alpha(2b)delta/beta(1b) mediated currents
(IC(50) = 4 and 24.6 microM, respectively). alpha(1E)-mediated currents
inactivated rapidly and mainly in a non-Ca(2+)-dependent manner, as evidenced by
the fact that 1) decreasing extracellular Ca(2+) from 10 to 2 mM and 2) changing
the intracellular concentration of the Ca(2+) chelator 1. 2-bis(2-aminophenoxy)
ethane-N,N,N',N'-tetraacetic acid (BAPTA), did not affect the inactivation
characteristics; 3) there was no clear-cut bell-shaped relationship between test
potential and inactivation, as would be expected from a Ca(2+)-dependent event.
Although Ba(2+) substitution did not affect the inactivation of alpha(1E)
channels, Na(+) substitution revealed a small but significant reduction in the
extent and rate of inactivation, suggesting that besides the presence of dominant
voltage-dependent inactivation, alpha(1E) channels are also affected by a
divalent cation-dependent inactivation process. We have analyzed the Ca(2+)
currents produced by a range of imposed action potential-like voltage protocols
(APVPs). The amplitude and area of the current were dependent on the duration of
the waveform employed and were relatively similar to those described for HVA
calcium channels. However, the peak latency resembled that obtained for low
voltage-activated (LVA) calcium channels. Short bursts of APVPs applied at 100 Hz
produced a depression of the Ca(2+) current amplitude, suggesting an accumulation
of inactivation likely to be calcium dependent. The human alpha(1E) gene seems to
participate to a Ca(2+) channel type with biophysical and pharmacological
properties partly resembling those of LVA and those of HVA channels, with
inactivation characteristics more complex than previously believed.
PMID- 10669484
TI - NMDA-Receptor-dependent synaptic activation of voltage-dependent calcium channels
in basolateral amygdala.
AB - Afferent stimulation of pyramidal cells in the basolateral amygdala produced
mixed excitatory postsynaptic potentials (EPSPs) mediated by N-methyl-D-aspartate
(NMDA) and non-NMDA glutamate receptors during whole cell current-clamp
recordings. In the presence of GABA(A) receptor blockade, the mixed EPSPs
recruited a large "all-or-none" depolarizing event. This recruited event was
voltage dependent and had a distinct activation threshold. An analogous
phenomenon elicited by exogenous glutamate in the presence of tetrodotoxin (TTX)
was blocked by Cd(2+), suggesting that the event was a Ca(2+) spike. Selective
glutamatergic blockade revealed that these Ca(2+) spikes were recruited readily
by single afferent stimulus pulses that elicited NMDA EPSPs. In contrast, non
NMDA EPSPs induced by single stimuli failed to elicit the Ca(2+) spike even at
maximal stimulus intensities although these non-NMDA EPSPs depolarized the soma
more effectively than mixed EPSPs. Elongation of non-NMDA EPSPs by cyclothiazide
or brief trains of stimulation were also unable to elicit the Ca(2+) spike.
Blockade of K(+) channels with intracellular Cs(+) enabled single non-NMDA EPSPs
to activate the Ca(2+) spike. The finding that voltage-dependent calcium channels
are activated preferentially by NMDA-receptor-mediated EPSPs provides a mechanism
for NMDA-receptor-dependent plasticity independent of Ca(2+) influx through the
NMDA receptor.
PMID- 10669485
TI - Recurrent excitatory connectivity in the dentate gyrus of kindled and kainic acid
treated rats.
AB - Repeated seizures induce mossy fiber axon sprouting, which reorganizes synaptic
connectivity in the dentate gyrus. To examine the possibility that sprouted mossy
fiber axons may form recurrent excitatory circuits, connectivity between granule
cells in the dentate gyrus was examined in transverse hippocampal slices from
normal rats and epileptic rats that experienced seizures induced by kindling and
kainic acid. The experiments were designed to functionally assess seizure-induced
development of recurrent circuitry by exploiting information available about the
time course of seizure-induced synaptic reorganization in the kindling model and
detailed anatomic characterization of sprouted fibers in the kainic acid model.
When recurrent inhibitory circuits were blocked by the GABA(A) receptor
antagonist bicuculline, focal application of glutamate microdrops at locations in
the granule cell layer remote from the recorded granule cell evoked trains of
excitatory postsynaptic potentials (EPSPs) and population burst discharges in
epileptic rats, which were never observed in slices from normal rats. The EPSPs
and burst discharges were blocked by bath application of 1 microM tetrodotoxin
and were therefore dependent on network-driven synaptic events. Excitatory
connections were detected between blades of the dentate gyrus in hippocampal
slices from rats that experienced kainic acid-induced status epilepticus. Trains
of EPSPs and burst discharges were also evoked in granule cells from kindled rats
obtained after > or = 1 wk of kindled seizures, but were not evoked in slices
examined 24 h after a single afterdischarge, before the development of sprouting.
Excitatory connectivity between blades of the dentate gyrus was also assessed in
slices deafferented by transection of the perforant path, and bathed in
artificial cerebrospinal fluid (ACSF) containing bicuculline to block GABA(A)
receptor-dependent recurrent inhibitory circuits and 10 mM [Ca(2+)](o) to
suppress polysynaptic activity. Low-intensity electrical stimulation of the
infrapyramidal blade under these conditions failed to evoke a response in
suprapyramidal granule cells from normal rats (n = 15), but in slices from
epileptic rats evoked an EPSP at a short latency (2.59 +/- 0.36 ms) in 5 of 18
suprapyramidal granule cells. The results are consistent with formation of
monosynaptic excitatory connections between blades of the dentate gyrus.
Recurrent excitatory circuits developed in the dentate gyrus of epileptic rats in
a time course that corresponded to the development of mossy fiber sprouting and
demonstrated patterns of functional connectivity corresponding to anatomic
features of the sprouted mossy fiber pathway.
PMID- 10669486
TI - Vasopressin increases GABAergic inhibition of rat hypothalamic paraventricular
nucleus neurons in vitro.
AB - This investigation used an in vitro hypothalamic brain slice preparation and
whole cell and perforated-patch recording to examine the response of
magnocellular neurons in hypothalamic paraventricular nucleus (PVN) to bath
applications of vasopressin (VP; 100-500 nM). In 22/38 cells, responses were
characterized by an increase in the frequency of bicuculline-sensitive inhibitory
postsynaptic potentials or currents with no detectable influence on excitatory
postsynaptic events. Perforated-patch recordings confirmed that VP did not have
an effect on intrinsic membrane properties of magnocellular PVN neurons (n = 17).
Analysis of intrinsic membrane properties obtained with perforated-patch
recording (n = 23) demonstrated that all of nine VP-sensitive neurons showed a
rebound depolarization after transient membrane hyperpolarization from rest. By
contrast, 12/14 nonresponding neurons displayed a delayed return to resting
membrane potentials. Recordings of reversed inhibitory postsynaptic currents with
chloride-loaded electrodes showed that responses to VP persisted in media
containing glutamate receptor antagonists but were abolished in the presence of
tetrodotoxin. In addition, responses were mimicked by vasotocin [Phe(2), Orn(8)],
a selective V(1a) receptor agonist, and blocked by [beta-Mercapto-beta, beta
cyclopentamethylenepropionyl(1),O-Me-Tyr(2), Arg(8)]-VP (Manning compound), a
V(1a)/OT receptor antagonist. Neither [deamino-Cys(1),Val(4),D-Arg(8)]-VP, a
selective V(2) receptor agonist, nor oxytocin were effective. Collectively, the
results imply that VP acts at V(1a) receptors to excite GABAergic neurons that
are presynaptic to a population of magnocellular PVN neurons the identity of
which features a unique rebound depolarization. Endogenous sources of VP may be
VP-synthesizing neurons in suprachiasmatic nucleus, known to project toward the
perinuclear regions of PVN, and/or the magnocellular neurons within PVN.
PMID- 10669487
TI - Control of cricket stridulation by a command neuron: efficacy depends on the
behavioral state.
AB - Crickets use different song patterns for acoustic communication. The stridulatory
pattern-generating networks are housed within the thoracic ganglia but are
controlled by the brain. This descending control of stridulation was identified
by intracellular recordings and stainings of brain neurons. Its impact on the
generation of calling song was analyzed both in resting and stridulating crickets
and during cercal wind stimulation, which impaired the stridulatory movements and
caused transient silencing reactions. A descending interneuron in the brain
serves as a command neuron for calling-song stridulation. The neuron has a dorsal
soma position, anterior dendritic processes, and an axon that descends in the
contralateral connective. The neuron is present in each side of the CNS. It is
not activated in resting crickets. Intracellular depolarization of the
interneuron so that its spike frequency is increased to 60-80 spikes/s reliably
elicits calling-song stridulation. The spike frequency is modulated slightly in
the chirp cycle with the maximum activity in phase with each chirp. There is a
high positive correlation between the chirp repetition rate and the interneuron's
spike frequency. Only a very weak correlation, however, exists between the
syllable repetition rate and the interneuron activity. The effectiveness of the
command neuron depends on the activity state of the cricket. In resting crickets,
experimentally evoked short bursts of action potentials elicit only incomplete
calling-song chirps. In crickets that previously had stridulated during the
experiment, short elicitation of interneuron activity can trigger sustained
calling songs during which the interneuron exhibits a spike frequency of
approximately 30 spikes/s. During sustained calling songs, the command neuron
activity is necessary to maintain the stridulatory behavior. Inhibition of the
interneuron stops stridulation. A transient increase in the spike frequency of
the interneuron speeds up the chirp rate and thereby resets the timing of the
chirp pattern generator. The interneuron also is excited by cercal wind
stimulation. Cercal wind stimulation can impair the pattern of chirp and syllable
generation, but these changes are not reflected in the discharge pattern of the
command neuron. During wind-evoked silencing reactions, the activity of the
calling-song command neuron remains unchanged, but under these conditions, its
activity is no longer sufficient to maintain stridulation. Therefore stridulation
can be suppressed by cercal inputs from the terminal ganglia without directly
inhibiting the descending command activity.
PMID- 10669488
TI - Neuropeptide Y(5) receptors reduce synaptic excitation in proximal subiculum, but
not epileptiform activity in rat hippocampal slices.
AB - Neuropeptide Y (NPY) potently inhibits excitatory synaptic transmission in the
hippocampus, acting predominantly via a presynaptic Y(2) receptor. Recent reports
that the Y(5) receptor may mediate the anticonvulsant actions of NPY in vivo
prompted us to test the hypothesis that Y(5) receptors inhibit synaptic
excitation in the hippocampal slice and, furthermore, that they are effective in
an in vitro model of anticonvulsant action. Two putative Y(5) receptor-preferring
agonists inhibited excitatory postsynaptic currents (EPSCs) evoked by stimulation
of stratum radiatum in pyramidal cells. We recorded initially from area CA1
pyramidal cells, but subsequently switched to cells from the subiculum, where a
much greater frequency of response was observed to Y(5) agonist application. Both
D-Trp(32)NPY (1 microM) and [ahx(8-20)]Pro(34)NPY (3 microM), a centrally
truncated, Y(1)/Y(5) agonist we synthesized, inhibited stimulus-evoked EPSCs in
subicular pyramidal cells by 44.0 +/- 5.7% and 51.3 +/- 3.5% (mean +/- SE), in 37
and 58% of cells, respectively. By contrast, the less selective centrally
truncated agonist, [ahx(8-20)] NPY (1 microM), was more potent (66.4 +/- 4.1%
inhibition) and more widely effective, suppressing the EPSC in 86% of subicular
neurons. The site of action of all NPY agonists tested was most probably
presynaptic, because agonist application caused no changes in postsynaptic
membrane properties. The selective Y(1) antagonist, BIBP3226 (1 microM), did not
reduce the effect of either more selective agonist, indicating that they
activated presynaptic Y(5) receptors. Y(5) receptor-mediated synaptic inhibition
was more frequently observed in slices from younger animals, whereas the
nonselective agonist appeared equally effective at all ages tested. Because of
the similarity with the previously reported actions of Y(2) receptors, we tested
the ability of Y(5) receptor agonists to suppress stimulus train-induced bursting
(STIB), an in vitro model of ictaform activity, in both area CA3 and the
subiculum. Neither [ahx(8-20)]Pro(34)NPY nor D-Trp(32)NPY were significantly
effective in suppressing or shortening STIB-induced afterdischarge, with <20% of
slices responding to these agonists in recordings from CA3 and none in subiculum.
By contrast, 1 microM each of [ahx(8-20)]NPY, the Y(2) agonist, [ahx(5-24)]NPY,
and particularly NPY itself suppressed the afterdischarge in area CA3 and the
subiculum, as reported earlier. We conclude that Y(5) receptors appear to
regulate excitability to some degree in the subiculum of young rats, but their
contribution is relatively small compared with those of Y(2) receptors, declines
with age, and is insufficient to block or significantly attenuate STIB-induced
afterdischarges.
PMID- 10669489
TI - Na(+) and K(+) concentrations, extra- and intracellular voltages, and the effect
of TTX in hypoxic rat hippocampal slices.
AB - Severe hypoxia causes rapid depolarization of CA1 neurons and glial cells that
resembles spreading depression (SD). In brain slices in vitro, the SD-like
depolarization and the associated irreversible loss of function can be postponed,
but not prevented, by blockade of Na(+) currents by tetrodotoxin (TTX). To
investigate the role of Na(+) flux, we made recordings from the CA1 region in
hippocampal slices in the presence and absence of TTX. We measured membrane
changes in single CA1 pyramidal neurons simultaneously with extracellular DC
potential (V(o)) and either extracellular [K(+)] or [Na(+)]; alternatively, we
simultaneously recorded [Na(+)](o), [K(+)](o), and V(o). Confirming previous
reports, early during hypoxia, before SD onset, [K(+)](o) began to rise, whereas
[Na(+)](o) still remained normal and V(o) showed a slight, gradual, negative
shift; neurons first hyperpolarized and then began to gradually depolarize. The
SD-like abrupt negative DeltaV(o) corresponded to a near complete depolarization
of pyramidal neurons and an 89% decrease in input resistance. [K(+)](o) increased
by 47 mM and [Na(+)](o) dropped by 91 mM. Changes in intracellular Na(+) and K(+)
concentrations, estimated on the basis of the measured extracellular ion levels
and the relative volume fractions of the neuronal, glial, and extracellular
compartment, were much more moderate. Because [Na(+)](o) dropped more than
[K(+)](o) increased, simple exchange of Na(+) for K(+) cannot account for these
ionic changes. The apparent imbalance of charge could be made up by Cl(-) influx
into neurons paralleling Na(+) flux and release of Mg(2+) from cells. The hypoxia
induced changes in interneurons resembled those observed in pyramidal neurons.
Astrocytes responded with an initial slow depolarization as [K(+)](o) rose. It
was followed by a rapid but incomplete depolarization as soon as SD occurred,
which could be accounted for by the reduced ratio, [K(+)](i)/[K(+)](o). TTX (1
microM) markedly postponed SD, but the SD-related changes in [K(+)](o) and
[Na(+)](o) were only reduced by 23 and 12%, respectively. In TTX-treated
pyramidal neurons, the delayed SD-like depolarization took off from a more
positive level, but the final depolarized intracellular potential and input
resistance were not different from control. We conclude that TTX-sensitive
channels mediate only a fraction of the Na(+) influx, and that some of the K(+)
is released in exchange for Na(+). Even though TTX-sensitive Na(+) currents are
not essential for the self-regenerative membrane changes during hypoxic SD, in
control solutions their activation may trigger the transition from gradual to
rapid depolarization of neurons, thereby synchronizing the SD-like event.
PMID- 10669490
TI - Low-voltage-activated calcium current does not regulate the firing behavior in
paired mechanosensory neurons with different adaptation properties.
AB - Low-voltage-activated Ca(2+) currents (LVA-I(Ca)) are believed to perform several
roles in neurons such as lowering the threshold for action potentials, promoting
burst firing and oscillatory behavior, and enhancing synaptic excitation. They
also may allow rapid increases in intracellular Ca(2+) concentration. We
discovered LVA-I(Ca) in both members of paired mechanoreceptor neurons in a
spider, where one neuron adapts rapidly (Type A) and the other slowly (Type B) in
response to a step stimulus. To learn if I(Ca) contributed to the difference in
adaptation behavior, we studied the kinetics of I(Ca) from isolated somata under
single-electrode voltage-clamp and tested its physiological function under
current clamp. LVA-I(Ca) was large enough to fire single action potentials when
all other voltage-activated currents were blocked, but we found no evidence that
it regulated firing behavior. LVA-I(Ca) did not lower the action potential
threshold or affect firing frequency. Previous experiments have failed to find
Ca(2+)-activated K(+) current (I(K(Ca))) in the somata of these neurons, so it is
also unlikely that LVA-I(Ca) interacts with I(K(Ca)) to produce oscillatory
behavior. We conclude that LVA-Ca(2+) channels in the somata, and possible in the
dendrites, of these neurons open in response to the depolarization caused by
receptor current and by the voltage-activated Na(+) current (I(Na)) that produces
action potential(s). However, the role of the increased intracellular Ca(2+)
concentration in neuronal function remains enigmatic.
PMID- 10669491
TI - Relationships between odor-elicited oscillations in the salamander olfactory
epithelium and olfactory bulb.
AB - Oscillations in neuronal population activity, or the synchronous neuronal spiking
that underlies them, are thought to play a functional role in sensory processing
in the CNS. In the olfactory system, stimulus-induced oscillations are observed
both in central processing areas and in the peripheral receptor epithelium. To
examine the relationship between these peripheral and central oscillations, we
recorded local field potentials simultaneously from the olfactory epithelium and
olfactory bulb in tiger salamanders (Ambystoma tigrinum). Stimulus-induced
oscillations recorded at these two sites were matched in frequency and slowed
concurrently over the time course of the response, suggesting that the
oscillations share a common source or are modulated together. Both the power and
duration of oscillations increased over a range of amyl acetate concentrations
from 2.5 x 10(-2) to 1 x 10(-1) dilution of saturated vapor, but peak frequency
was not affected. The frequency of the oscillation did vary with different
odorant compounds in both olfactory epithelium and bulb (OE and OB): amyl
acetate, ethyl fenchol and d-carvone elicited oscillations of significantly
different frequencies, and there was no difference in OE and OB oscillation
frequencies. No change in the power or frequency of OE oscillations was observed
after sectioning the olfactory nerve, indicating that the OE oscillations have a
peripheral source. Finally, application of 1.0 and 10 microM tetrodotoxin to the
epithelium blocked OE oscillations in a dose-dependent and reversible manner,
suggesting that peripheral olfactory oscillations are related to receptor neuron
spiking.
PMID- 10669492
TI - Prototypical imidazoline-1 receptor ligand moxonidine activates alpha2
adrenoceptors in bulbospinal neurons of the RVL.
AB - Moxonidine is an antihypertensive drug that lowers sympathetic vasomotor tone by
stimulating either alpha2-adrenergic (alpha2-AR) or imidazoline I1 receptors
within the rostral ventrolateral medulla (RVL). In this study, we investigated
the effects of moxonidine (10 microM) on RVL neurons in brain stem slices of
neonatal rats. We recorded mainly from retrogradely labeled RVL bulbospinal
neurons (putative presympathetic neurons) except for some extracellular
recordings. Prazosin was used to block alpha1-adrenoceptors. Moxonidine inhibited
the extracellularly recorded discharges of all spontaneously active RVL neurons
tested (bulbospinal and unidentified). This effect was reversed or blocked by the
selective alpha2-AR antagonist SKF 86466 (10 microM). In contrast, the I1
imidazoline ligand AGN 192403 (10 microM) had no effect on the spontaneous
activity. In whole cell recordings (holding potential -70 mV), moxonidine
produced a small and variable outward current (mean 7 pA). This current was
observed in both tyrosine hydroxylase-immunoreactive and other bulbospinal
neurons and was blocked by SKF 86466. Excitatory postsynaptic currents (EPSCs)
evoked by focal electrical stimulation were isolated by incubation with gabazine
and strychnine, and inhibitory postsynaptic currents (IPSCs) were isolated with 6
cyano-7-nitroquinoxaline-2,3-dione (CNQX). Moxonidine reduced the amplitude of
the evoked EPSCs (EC(50) = 1 microM; 53% inhibition at 10 microM) but not their
decay time constant (5.6 ms). The effect of moxonidine on EPSCs persisted in
barium (300 microM) and was reduced approximately 80% by SKF 86466. Moxonidine
also reduced the amplitude of evoked IPSCs by 63%. In conclusion, moxonidine
inhibits putative RVL presympathetic neurons both presynaptically and
postsynaptically. All observed effects in the present study are consistent with
an alpha2-AR agonist activity of moxonidine.
PMID- 10669493
TI - Effects of attention on MT and MST neuronal activity during pursuit initiation.
AB - The responses of neurons in monkey extrastriate areas MT (middle temporal) and
MST (medial superior temporal), and the initial metrics of saccadic and pursuit
eye movements, have previously been shown to be better predicted by vector
averaging or winner-take-all models depending on the stimulus conditions. To
investigate the potential influences of attention on the neuronal activity, we
measured the responses of single MT and MST neurons under identical stimulus
conditions when one of two moving stimuli was the target for a pursuit eye
movement. We found the greatest attentional modulation across neurons when two
stimuli moved through the receptive field (RF) of the neuron and the stimulus
motion was initiated at least 450 ms before reaching the center of the RF. These
conditions were the same as those in which a winner-take-all model better
predicted both the eye movements and the underlying neuronal activity. The
modulation was almost always an increase of activity, and it was about equally
frequent in MT and MST. A modulation of >50% was observed in approximately 41% of
MT neurons and 27% of MST neurons. Responses to all directions of motion were
modulated so that the direction tuning curves in the attended and unattended
conditions were similar. Changes in the background activity with target selection
were small and unlikely to account for the observed attentional modulation. In
contrast, there was little change in the neuronal response with attention when
the stimulus reached the RF center 150 ms after motion onset, which was also the
condition in which the vector average model better predicted the initial eye
movements and the activity of the neurons. These results are consistent with a
competition model of attention in which top-down attention acts on the activity
of one of two competing populations of neurons activated by the bottom-up input
from peripheral stimuli. They suggest that there is a minimal separation of the
populations necessary before attention can act on one population, similar to that
required to produce a winner-take-all mode of behavior in pursuit initiation. The
present experiments also suggest that it takes several hundred milliseconds to
develop this top-down attention effect.
PMID- 10669494
TI - Effect of high Ba(2+) on norepinephrine-induced inhibition of N-type calcium
current in bullfrog sympathetic neurons.
AB - The voltage-dependent inhibition of N-type calcium current by neurotransmitters
is the best-understood example of neuronal calcium channel inhibition. One of the
mechanisms by which this pathway is thought to inhibit the calcium current is by
reducing the permeation of divalent cations through the channel. In this study
one prediction of this hypothesis was examined, that high concentrations of
divalent cations reduce the maximum neurotransmitter-induced inhibition.
Norepinephrine (NE)-induced inhibition was compared in external solutions
containing either 2 or 100 mM Ba(2+). Initially, NE dose-response curves were
generated by averaging data from many neurons, and it was found that the
relationship was right shifted in the high-Ba(2+) external solution without an
effect on maximum inhibition. The IC(50) was 0.6 and 3 microM in 2 and 100 mM
Ba(2+), respectively. This shift was verified by comparing the effect of NE on
single neurons exposed to both 2 and 100 mM Ba(2+). The inhibition induced by 1
microM NE was reduced in 100 mM Ba(2+) compared with that in 2 mM Ba(2+).
However, the response to 100 microM NE was identical between high and low Ba(2+).
Thus, divalent cations appear to act as a competitive inhibitor of NE binding,
which likely results from these ions' interacting with negatively charged amino
acids that are important for catecholamine binding to adrenergic receptors.
Because the maximum inhibition induced by NE was similar in low and high Ba(2+),
the effect of inhibition on single N-type calcium channels was not altered by the
divalent cation concentration.
PMID- 10669495
TI - Conditioned eyeblink response consists of two distinct components.
AB - The aim of these experiments was to obtain a detailed knowledge of how the
orbicularis oculi muscle is activated during the execution of a conditioned
eyeblink response (CR). This is the first critical step to understand the
underlying neural mechanisms involved in the control of the CR. Decerebrate
ferrets were trained in a classical conditioning paradigm. The conditioned
stimulus (CS) was a train of electrical stimuli (15 pulses, 50 Hz, 1 mA) applied
to the forelimb, and the unconditioned stimulus (US) was a train of electrical
stimuli (3 pulses, 50 Hz, 3-4 mA) to the periorbital region. The CRs were studied
by recording electromyograms (EMGs) from the orbicularis oculi muscle. The
eyeblink CR in all animals showed a similar topography with at least two
different components, CR1 and CR2, which were expressed at different rates. CR1
appeared first during acquisition, had a shorter onset latency, and was more
phasic and more resistant to extinction than CR2. A marked pause in the muscle
activity separated the two components. To control that the two-component CR were
not species, paradigm or preparation specific, awake rabbits were trained with a
tone CS (300 ms, 4 kHz, 64 dB) and a train of periorbital stimuli as US (3
pulses, 50 Hz, 3 mA). CR1 and CR2 were present in the rabbit eyeblink CR. The
cerebellum is implicated in the control of CRs and to study whether separate
neural pathways were responsible for CR1 and CR2, direct brachium pontis
stimulation was used to replace the forelimb CS. CR1 and CR2 were present in the
CR elicited by the brachium pontis CS. The presence of CR1 and CR2 after a
unilateral lesion of the brachium conjunctivum shows that output from the
contralateral cerebellar hemisphere was not the cause for any of the components.
Other mechanisms that might be involved in the separation of the CR into two
components are discussed. The results show that the eyeblink CR consists of at
least two components, CR1 and CR2, which most likely originate either as a direct
central command from the cerebellum or in the output pathway before the facial
nucleus.
PMID- 10669496
TI - Intrinsic dynamics in neuronal networks. I. Theory.
AB - Many networks in the mammalian nervous system remain active in the absence of
stimuli. This activity falls into two main patterns: steady firing at low rates
and rhythmic bursting. How are these firing patterns generated? Specifically, how
do dynamic interactions between excitatory and inhibitory neurons produce these
firing patterns, and how do networks switch from one firing pattern to the other?
We investigated these questions theoretically by examining the intrinsic dynamics
of large networks of neurons. Using both a semianalytic model based on mean
firing rate dynamics and simulations with large neuronal networks, we found that
the dynamics, and thus the firing patterns, are controlled largely by one
parameter, the fraction of endogenously active cells. When no endogenously active
cells are present, networks are either silent or fire at a high rate; as the
number of endogenously active cells increases, there is a transition to bursting;
and, with a further increase, there is a second transition to steady firing at a
low rate. A secondary role is played by network connectivity, which determines
whether activity occurs at a constant mean firing rate or oscillates around that
mean. These conclusions require only conventional assumptions: excitatory input
to a neuron increases its firing rate, inhibitory input decreases it, and neurons
exhibit spike-frequency adaptation. These conclusions also lead to two
experimentally testable predictions: 1) isolated networks that fire at low rates
must contain endogenously active cells and 2) a reduction in the fraction of
endogenously active cells in such networks must lead to bursting.
PMID- 10669497
TI - Intrinsic dynamics in neuronal networks. II. experiment.
AB - Neurons in many regions of the mammalian CNS remain active in the absence of
stimuli. This activity falls into two main patterns: steady firing at low rates
and rhythmic bursting. How these firing patterns are maintained in the presence
of powerful recurrent excitation, and how networks switch between them, is not
well understood. In the previous paper, we addressed these issues theoretically;
in this paper we address them experimentally. We found in both studies that a key
parameter in controlling firing patterns is the fraction of endogenously active
cells. The theoretical analysis indicated that steady firing rates are possible
only when the fraction of endogenously active cells is above some threshold, that
there is a transition to bursting when it falls below that threshold, and that
networks becomes silent when the fraction drops to zero. Experimentally, we found
that all steadily firing cultures contain endogenously active cells, and that
reducing the fraction of such cells in steadily firing cultures causes a
transition to bursting. The latter finding implies indirectly that the
elimination of endogenously active cells would cause a permanent drop to zero
firing rate. The experiments described here thus corroborate the theoretical
analysis.
PMID- 10669498
TI - Kinetic and frequency-domain properties of reflex and conditioned eyelid
responses in the rabbit.
AB - Eyelid position and the electromyographic activity of the orbicularis oculi
muscle were recorded unilaterally in rabbits during reflex and conditioned
blinks. Air-puff-evoked blinks consisted of a fast downward phase followed
sometimes by successive downward sags. The reopening phase had a much longer
duration and slower peak velocity. Onset latency, maximum amplitude, peak
velocity, and rise time of reflex blinks depended on the intensity and duration
of the air puff-evoking stimulus. A flashlight focused on the eye also evoked
reflex blinks, but not flashes of light, or tones. Both delayed and trace
classical conditioning paradigms were used. For delayed conditioning, animals
were presented with a 350-ms, 90-dB, 600-Hz tone, as conditioned stimulus (CS).
For trace conditioning, animals were presented with a 10-ms, 1-k/cm(2) air puff,
as CS. The unconditioned stimulus (US) consisted of a 100-ms, 3-k/cm(2) air puff.
The stimulus interval between CS and US onsets was 250 ms. Conditioned responses
(CRs) to tones were composed of downward sags that increased in number through
the successive conditioning sessions. The onset latency of the CR decreased
across conditioning at the same time as its maximum amplitude and its peak
velocity increased, but the time-to-peak of the CR remained unaltered. The
topography of CRs evoked by short, weak air puffs as the CS showed three
different components: the alpha response to the CS, the CR, and the reflex
response to the US. Through conditioning, CRs showed a decrease in onset latency,
and an increase in maximum amplitude and peak velocity. The time-to-peak of the
CR remained unchanged. A power spectrum analysis of reflex and conditioned blink
acceleration profiles showed a significant approximately 8-Hz oscillation within
a broadband of frequencies between 4 and 15 Hz. Nose and mandible movements
presented power spectrum profiles different from those characterizing reflex and
conditioned blinks. It is concluded that eyelid reflex responses in the rabbit
present significant differences from CRs in their profiles and metric properties,
suggesting different neural origins, but that a common approximately 8-Hz neural
oscillator underlies lid motor performance. According to available data, the
frequency of this putative oscillator seems to be related to the species size.
PMID- 10669499
TI - Activity of reticulospinal neurons during locomotion in the freely behaving
lamprey.
AB - The reticulospinal (RS) system is the main descending system transmitting
commands from the brain to the spinal cord in the lamprey. It is responsible for
initiation of locomotion, steering, and equilibrium control. In the present
study, we characterize the commands that are sent by the brain to the spinal cord
in intact animals via the reticulospinal pathways during locomotion. We have
developed a method for recording the activity of larger RS axons in the spinal
cord in freely behaving lampreys by means of chronically implanted
macroelectrodes. In this paper, the mass activity in the right and left RS
pathways is described and the correlations of this activity with different
aspects of locomotion are discussed. In quiescent animals, the RS neurons had a
low level of activity. A mild activation of RS neurons occurred in response to
different sensory stimuli. Unilateral eye illumination evoked activation of the
ipsilateral RS neurons. Unilateral illumination of the tail dermal photoreceptors
evoked bilateral activation of RS neurons. Water vibration also evoked bilateral
activation of RS neurons. Roll tilt evoked activation of the contralateral RS
neurons. With longer or more intense sensory stimulation of any modality and
laterality, a sharp, massive bilateral activation of the RS system occurred, and
the animal started to swim. This high activity of RS neurons and swimming could
last for many seconds after termination of the stimulus. There was a positive
correlation between the level of activity of RS system and the intensity of
locomotion. An asymmetry in the mass activity on the left and right sides
occurred during lateral turns with a 30% prevalence (on average) for the
ipsilateral side. Rhythmic modulation of the activity in RS pathways, related to
the locomotor cycle, often was observed, with its peak coinciding with the
electromyographic (EMG) burst in the ipsilateral rostral myotomes. The pattern of
vestibular response of RS neurons observed in the quiescent state, that is,
activation with contralateral roll tilt, was preserved during locomotion. In
addition, an inhibition of their activity with ipsilateral tilt was clearly seen.
In the cases when the activity of individual neurons could be traced during
swimming, it was found that rhythmic modulation of their firing rate was
superimposed on their tonic firing or on their vestibular responses. In
conclusion, different aspects of locomotor activity-initiation and termination,
vigor of locomotion, steering and equilibrium control-are well reflected in the
mass activity of the larger RS neurons.
PMID- 10669500
TI - Responses of reticulospinal neurons in intact lamprey to vestibular and visual
inputs.
AB - A lamprey maintains the dorsal-side-up orientation due to the activity of
postural control system driven by vestibular input. Visual input can affect the
body orientation: illumination of one eye evokes ipsilateral roll tilt. An
important element of the postural network is the reticulospinal (RS) neurons
transmitting commands from the brain stem to the spinal cord. Here we describe
responses to vestibular and visual stimuli in RS neurons of the intact lamprey.
We recorded activity from the axons of larger RS neurons with six extracellular
electrodes chronically implanted on the surface of the spinal cord. From these
multielectrode recordings of mass activity, discharges in individual axons were
extracted by means of a spike-sorting program, and the axon position in the
spinal cord and its conduction velocity were determined. Vestibular stimulation
was performed by rotating the animal around its longitudinal axis in steps of 45
degrees through 360 degrees. Nonpatterned visual stimulation was performed by
unilateral eye illumination. All RS neurons were classified into two groups
depending on their pattern of response to vestibular and visual stimuli; the
groups also differed in the axon position in the spinal cord and its conduction
velocity. Each group consisted of two symmetrical, left and right, subgroups. In
group 1 neurons, rotation of the animal evoked both dynamic and static responses;
these responses were much larger when rotation was directed toward the
contralateral labyrinth, and the dynamic responses to stepwise rotation occurred
at any initial orientation of the animal, but they were more pronounced within
the angular zone of 0-135 degrees. The zone of static responses approximately
coincided with the zone of pronounced dynamic responses. The group 1 neurons
received excitatory input from the ipsilateral eye and inhibitory input from the
contralateral eye. When vestibular stimulation was combined with illumination of
the ipsilateral eye, both dynamic and static vestibular responses were augmented.
Contralateral eye illumination caused a decrease of both types of responses.
Group 2 neurons responded dynamically to rotation in both directions throughout
360 degrees. They received excitatory inputs from both eyes. Axons of the group 2
neurons had higher conduction velocity and were located more medially in the
spinal cord as compared with the group 1 neurons. We suggest that the
reticulospinal neurons of group 1 constitute an essential part of the postural
network in the lamprey. They transmit orientation-dependent command signals to
the spinal cord causing postural corrections. The role of these neurons is
discussed in relation to the model of the roll control system formulated in our
previous studies.
PMID- 10669501
TI - 2-Deoxyglucose-induced long-term potentiation of monosynaptic IPSPs in CA1
hippocampal neurons.
AB - In previous experiments on excitatory synaptic transmission in CA1, temporary (10
20 min) replacement of glucose with 10 mM 2-deoxyglucose (2-DG) consistently
caused a marked and very sustained potentiation (2-DG LTP). To find out whether 2
DG has a similar effect on inhibitory synapses, we recorded pharmacologically
isolated mononosynaptic inhibitory postsynaptic potentials (IPSPs; under current
clamp) and inhibitory postsynaptic currents (IPSCs; under voltage clamp); 2-DG
was applied both in the presence and the absence of antagonists of N-methyl-D
aspartate (NMDA). In spite of sharply varied results (some neurons showing large
potentiation, lasting for >1 h, and many little or none), overall there was a
significant and similar potentiation of IPSP conductance, both for the early (at
approximately 30 ms) and later (at approximately 140 ms) components of IPSPs or
IPSCs: by 35.1 +/- 10.25% (mean +/- SE; for n = 24, P = 0.0023) and 36.5 +/-
16.3% (for n = 19, P = 0.038), respectively. The similar potentiation of the
early and late IPSP points to a presynaptic mechanism of LTP. Overall, the LTP
was statistically significant only when 2-DG was applied in the absence of
glutamate antagonists. Tetanic stimulations (in presence or absence of glutamate
antagonists) only depressed IPSPs (by half). In conclusion, although smaller and
more variable, 2-DG-induced LTP of inhibitory synapses appears to be broadly
similar to the 2-DG-induced LTP of excitatory postsynaptic potentials previously
observed in CA1.
PMID- 10669502
TI - Sacrocaudal afferents induce rhythmic efferent bursting in isolated spinal cords
of neonatal rats.
AB - The ability of mammalian spinal cords to generate rhythmic motor behavior in
nonlimb moving segments was examined in isolated spinal cords of neonatal rats.
Stimulation of sacrocaudal afferents (SCA) induced alternating left-right bursts
in lumbosacral efferents and in tail muscles. On each side of the tail, flexors,
extensors, and abductors were coactive during each cycle of activity. This rhythm
originated mainly in the sacrocaudal region because it persisted in sacrocaudal
segments after surgical removal of the thoracolumbar cord. Sacrocaudal
commissural pathways were sufficient to maintain the left-right alternation of
lumbar efferent bursts, because their timing was unaltered after a complete
thoracolumbar hemisection. The lumbar rhythm originated in part from sacrocaudal
activity ascending in lateral and ventrolateral funiculi, because efferent bursts
in rostral lumbar segments were nearly abolished on a particular side by lesions
of the lateral quadrant of the cord at the L(4)-L(5) junction. Intracellular
recordings from S(2)-S(3) motoneurons, obtained during the rhythm, revealed the
presence of phasic oscillations of membrane potential superimposed on a tonic
depolarization. Bursts of spikes occurred on the depolarizing phases of the
oscillation. Between these bursts the membrane input conductance increased, and
hyperpolarizing drive potentials were revealed. The inhibitory drive and the
decreased input resistance coincided with contralateral efferent bursts,
suggesting that crossed pathways controlled it. Our studies indicate that pattern
generators are not restricted to limb-moving spinal segments and suggest that
regional specializations of pattern-generating circuitry and their associated
interneurons are responsible for the different motor patterns produced by the
mammalian spinal cord.
PMID- 10669503
TI - Impairments in prehension produced by early postnatal sensory motor cortex
activity blockade.
AB - This study examined the effects of blocking neural activity in sensory motor
cortex during early postnatal development on prehension. We infused muscimol,
either unilaterally or bilaterally, into the sensory motor cortex of cats to
block activity continuously between postnatal weeks 3-7. After stopping infusion,
we trained animals to reach and grasp a cube of meat and tested behavior
thereafter. Animals that had not received muscimol infusion (unilateral saline
infusion; age-matched) reached for the meat accurately with small end-point
errors. They grasped the meat using coordinated digit flexion followed by forearm
supination on 82.7% of trials. Performance using either limb did not differ
significantly. In animals receiving unilateral muscimol infusion, reaching and
grasping using the limb ipsilateral to the infusion were similar to controls. The
limb contralateral to infusion showed significant increases in systematic and
variable reaching end-point errors, often requiring subsequent corrective
movements to contact the meat. Grasping occurred on only 14.8% of trials,
replaced on most trials by raking without distal movements. Compensatory
adjustments in reach length and angle, to maintain end-point accuracy as
movements were started from a more lateral position, were less effective using
the contralateral limb than ipsilateral limb. With bilateral inactivations, the
form of reaching and grasping impairments was identical to that produced by
unilateral inactivation, but the magnitude of the reaching impairments was less.
We discuss these results in terms of the differential effects of unilateral and
bilateral inactivation on corticospinal tract development. We also investigated
the degree to which these prehension impairments after unilateral blockade
reflect control by each hemisphere. In animals that had received unilateral
blockade between postnatal weeks (PWs) 3 and 7, we silenced on-going activity
(after PW 11) during task performance using continuous muscimol infusion. We
inactivated the right (previously active) and then the left (previously silenced)
sensory motor cortex. Inactivation of the ipsilateral (right) sensory motor
cortex produced a further increase in systematic error and less frequent normal
grasping. Reinactivation of the contralateral (left) cortex produced larger
increases in reaching and grasping impairments than those produced by ipsilateral
inactivation. This suggests that the impaired limb receives bilateral sensory
motor cortex control but that control by the contralateral (initially silenced)
cortex predominates. Our data are consistent with the hypothesis that the normal
development of skilled motor behavior requires activity in sensory motor cortex
during early postnatal life.
PMID- 10669504
TI - Directionality derived from pinna-cue spectral notches in cat dorsal cochlear
nucleus.
AB - We tested two hypotheses to determine whether dorsal cochlear nucleus (DCN)
neurons are specialized to derive directionality from spectral notches: DCN
neurons exhibit greater spectral-dependent directionality than ventral cochlear
nucleus (VCN) neurons, and spectral-dependent directionality depends on response
minima (nulls) produced by coincidence of best frequency (BF) and spectral-notch
center frequency. Single-unit responses to 50-ms noise and tone bursts were
recorded in barbiturate-anesthetized cats (BFs: 4-37 kHz). Units were classified
using BF tone poststimulus time histograms. Pauser, onset-G (type II
interneurons), and some chopper units were recorded from the DCN. Primary-like,
onset-CIL (onset other than onset-G), and most choppers in the sample were
recorded from the VCN. Many pauser and onset-G units were highly directional to
noise. Chopper, onset-CIL, and primary-like units (collectively referred to as C
O-P units) were not. The difference in directionality depends on a monaural
mechanism as pausers were more directional to monaural noise than C-O-P units.
Contralateral inhibition produced a small increase in pauser directionality to
noise simulation but had no effect on directionality of C-O-P units. Pauser and C
O-P units exhibited similar low directionality to BF tone, showing that the
difference in noise directionality between groups depends on spectral cues. These
results show that spectral-dependent directionality is a DCN specialization.
Azimuth functions of highly directional units exhibited response nulls, and there
was a linear relationship between BFs in the range of 8-13 kHz and azimuthal
locations of nulls. This relationship parallels the known spatial distribution of
spectral-notch center frequencies on the horizontal plane. Furthermore spatial
receptive fields of pausers show response nulls that follow the expected diagonal
trajectory of the spectral notch in this frequency range. These results show that
DCN spectral-dependent directionality depends on response nulls produced by
coincidence of unit BF and spectral-notch center-frequency.
PMID- 10669505
TI - Pharmacological evidence of inhibitory and disinhibitory neuronal circuits in
dorsal cochlear nucleus.
AB - The dorsal cochlear nucleus (DCN) is rich in both glycine and GABA inhibitory
neurotransmitter systems, and the response properties of its principal cells
(pyramidal and giant cells) are strongly shaped by inhibitory inputs. For
example, DCN principal cells often display highly nonmonotonic (so-called type
IV) input-output functions in response to best-frequency (BF) tones. In this
study, the inhibitory inputs onto the principal cell types and onto response
types of known inhibitory interneurons were compared before and during
iontophoretic application of the glycine- and GABA(A)-receptor antagonists,
strychnine and bicuculline. Strychnine eliminates the central (on-BF) inhibitory
area in type IV units, resulting in monotonic BF rate-level curves. Unexpectedly,
bicuculline primarily enhances inhibition in principal-cell types; for example,
type IV units are inhibited at lower sound levels in the presence of bicuculline.
Principal cell types with weaker inhibitory inputs (type IV-T and type III units)
are more strongly inhibited in the presence of bicuculline and usually are
converted into type IV units. This enhancement of on-BF inhibition by bicuculline
suggests a disinhibitory process involving GABA(A) action on a non-GABA(A)ergic
inhibitory pathway. This latter pathway is probably glycinergic and involves type
II units (deep-layer vertical cells) and/or complex-spiking units (superficial
cartwheel cells) because both of these unit types are disinhibited by
bicuculline. One intrinsic GABA(A) source could be the superficial stellate cells
in DCN because bicuculline partly blocks the inhibition evoked by somatosensory
stimulated activation of the superficial granule-cell circuitry in DCN. Taken
together, the results suggest that glycinergic circuits mediate directly the
inhibition of DCN principal cells, but that GABA(A)ergic circuits modulate the
strength of the inhibition.
PMID- 10669506
TI - Contextual influence on orientation discrimination of humans and responses of
neurons in V1 of alert monkeys.
AB - We studied the effects of various patterns as contextual stimuli on human
orientation discrimination, and on responses of neurons in V1 of alert monkeys.
When a target line is presented along with various contextual stimuli (masks),
human orientation discrimination is impaired. For most V1 neurons, responses
elicited by a line in the receptive field (RF) center are suppressed by these
contextual patterns. Orientation discrimination thresholds of human observers are
elevated slightly when the target line is surrounded by orthogonal lines. For
randomly oriented lines, thresholds are elevated further and even more so for
lines parallel to the target. Correspondingly, responses of most V1 neurons to a
line are suppressed. Although contextual lines inhibit the amplitude of
orientation tuning functions of most V1 neurons, they do not systematically alter
the tuning width. Elevation of human orientation discrimination thresholds
decreases with increasing curvature of masking lines, so does the inhibition of
V1 neuronal responses. A mask made of straight lines yields the strongest
interference with human orientation discrimination and produces the strongest
suppression of neuronal responses. Elevation of human orientation discrimination
thresholds is highest when a mask covers only the immediate vicinity of the
target line. Increasing the masking area results in less interference. On the
contrary, suppression of neuronal responses in V1 increases with increasing mask
size. Our data imply that contextual interference observed in human orientation
discrimination is in part directly related to contextual inhibition of neuronal
activity in V1. However, the finding that interference with orientation
discrimination is weaker for larger masks suggests a figure-ground segregation
process that is not located in V1.
PMID- 10669507
TI - Silent NMDA receptor-mediated synapses are developmentally regulated in the
dorsal horn of the rat spinal cord.
AB - In vitro whole cell patch-clamp recording techniques were utilized to study
silent pure-N-methyl-D-aspartate (NMDA) receptor-mediated synaptic responses in
lamina II (substantia gelatinosa, SG) and lamina III of the spinal dorsal horn.
To clarify whether these synapses are present in the adult and contribute to
neuropathic pain, transverse lumbar spinal cord slices were prepared from
neonatal, naive adult and adult sciatic nerve transected rats. In neonatal rats,
pure-NMDA receptor-mediated excitatory postsynaptic currents (EPSCs) were
elicited in SG neurons either by focal intraspinal stimulation (n = 15 of 20
neurons) or focal stimulation of the dorsal root (n = 2 of 7 neurons). In
contrast, in slices from naive adult rats, no silent pure-NMDA EPSCs were
recorded in SG neurons following focal intraspinal stimulation (n = 27), and only
one pure-NMDA EPSC was observed in lamina III (n = 23). Furthermore, in rats with
chronic sciatic nerve transection, pure-NMDA EPSCs were elicited by focal
intraspinal stimulation in only 2 of 45 SG neurons. Although a large increase in
Abeta fiber evoked mixed alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
(AMPA) and NMDA receptor-mediated synapses was detected after sciatic nerve
injury, Abeta fiber-mediated pure-NMDA EPSCs were not evoked in SG neurons by
dorsal root stimulation. Pure-NMDA receptor-mediated EPSCs are therefore a
transient, developmentally regulated phenomenon, and, although they may have a
role in synaptic refinement in the immature dorsal horn, they are unlikely to be
involved in receptive field plasticity in the adult.
PMID- 10669508
TI - Effects of intracolonic opioid receptor agonists on polymodal pelvic nerve
afferent fibers in the rat.
AB - We studied the effects of intracolonic administration of opioid receptor agonists
(ORAs) on responses of pelvic nerve afferent fibers to colorectal distension
(CRD) and heat. Single-fiber recordings were made from the decentralized S1
dorsal rootlet in the rat. An approximately 7-cm length of descending colon was
isolated in situ to permit intracolonic perfusion with Krebs solution, which,
when the outflow was clamped, was used to distend the colon. Responses to noxious
CRD (40 mmHg, 30 s) were tested after intracolonic instillation of mu-, delta- or
kappa-ORAs. Intracolonic administration of the kappa-ORAs EMD 61,753 (n = 5/12)
and U62,066 (n = 8/11), but not either the mu-ORA fentanyl or the delta-ORA SNC
80, concentration-dependently inhibited responses of afferent fibers. For fibers
unaffected by intracolonic administration of EMD 61,753 or U62,066, intra
arterial administration of kappa-ORAs was effective. Forty-one of 54
mechanosensitive fibers also responded to intracolonic instillation of heated
Krebs solution (50 degrees C). Intra-arterial injection of fentanyl or SNC-80 did
not attenuate responses to heat. Either intracolonic or intra-arterial
administration of EMD 61,753 or U62, 066, however, inhibited afferent fiber
responses to heat. These results document that mechanical and thermal sensitivity
of polymodal pelvic nerve afferent fibers innervating the rat colon can be
inhibited peripherally by intracolonic instillation of kappa-ORAs.
PMID- 10669509
TI - Precision of the pacemaker nucleus in a weakly electric fish: network versus
cellular influences.
AB - We investigated the relative influence of cellular and network properties on the
extreme spike timing precision observed in the medullary pacemaker nucleus (Pn)
of the weakly electric fish Apteronotus leptorhynchus. Of all known biological
rhythms, the electric organ discharge of this and related species is the most
temporally precise, with a coefficient of variation (CV = standard deviation/mean
period) of 2 x 10(-4) and standard deviation (SD) of 0.12-1.0 micros. The timing
of the electric organ discharge is commanded by neurons of the Pn, individual
cells of which we show in an in vitro preparation to have only a slightly lesser
degree of precision. Among the 100-150 Pn neurons, dye injection into a pacemaker
cell resulted in dye coupling in one to five other pacemaker cells and one to
three relay cells, consistent with previous results. Relay cell fills, however,
showed profuse dendrites and contacts never seen before: relay cell dendrites dye
coupled to one to seven pacemaker and one to seven relay cells. Moderate (0.1-10
nA) intracellular current injection had no effect on a neuron's spiking period,
and only slightly modulated its spike amplitude, but could reset the spike phase.
In contrast, massive hyperpolarizing current injections (15-25 nA) could force
the cell to skip spikes. The relative timing of subthreshold and full spikes
suggested that at least some pacemaker cells are likely to be intrinsic
oscillators. The relative amplitudes of the subthreshold and full spikes gave a
lower bound to the gap junctional coupling coefficient of 0.01-0.08. Three drugs,
called gap junction blockers for their mode of action in other preparations,
caused immediate and substantial reduction in frequency, altered the phase lag
between pairs of neurons, and later caused the spike amplitude to drop, without
altering the spike timing precision. Thus we conclude that the high precision of
the normal Pn rhythm does not require maximal gap junction conductances between
neurons that have ordinary cellular precision. Rather, the spiking precision can
be explained as an intrinsic cellular property while the gap junctions act to
frequency- and phase-lock the network oscillations.
PMID- 10669510
TI - Gap junction effects on precision and frequency of a model pacemaker network.
AB - We investigated the precision of spike timing in a model of gap junction-coupled
oscillatory neurons. The model incorporated the known physiology, morphology, and
connectivity of the weakly electric fish's high-frequency and extremely precise
pacemaker nucleus (Pn). Two neuron classes, pacemaker and relay cells, were each
modeled with two compartments containing Hodgkin-Huxley sodium and potassium
currents. Isolated pacemaker cells fired periodically, due to a constant current
injection; relay cells were silent but slightly depolarized at rest. When coupled
by gap junctions to other neurons, a model neuron, like its biological correlate,
spiked at frequencies and amplitudes that were largely independent of current
injections. The phase distribution in the network was labile to intracellular
current injections and to gap junction conductance changes. The model predicts a
biologically plausible gap junction conductance of 4-5 nS (200-250 MOmega). This
results in a coupling coefficient of approximately 0.02, as observed in vitro.
Network parameters were varied to test which could improve the temporal precision
of oscillations. Increased gap junction conductances and larger numbers of cells
(holding total junctional conductance per cell constant) both substantially
reduced the coefficient of variation (CV = standard deviation/mean) of relay cell
spike times by 74-85% and more, and did so with lower gap junction conductance
when cells were contacted axonically compared with somatically. Pacemaker cell CV
was only reduced when the probability of contact was increased, and then only
moderately: a fivefold increase in the probability of contact reduced CV by 35%.
We conclude that gap junctions facilitate synchronization, can reduce CV, are
most effective between axons, and that pacemaker cells must have low intrinsic CV
to account for the low CV of cells in the biological network.
PMID- 10669511
TI - Modifications of seizure susceptibility in Drosophila.
AB - In a given population, certain individuals are much more likely to have seizures
than others. This increase in seizure susceptibility can lead to spontaneous
seizures, such as seen in idiopathic epilepsy, or to symptomatic seizures that
occur after insults to the nervous system. Despite the frequency of these seizure
disorders in the human population, the genetic and physiological basis for these
defects remains unclear. The present study makes use of Drosophila as a
potentially powerful model for understanding seizure susceptibility in humans. In
addition to the genetic and molecular advantages of using Drosophila, it has been
found that seizures in Drosophila share much in common with seizures seen in
humans. However, the most powerful aspect of this model lies in the ability to
accurately measure seizure susceptibility across genotypes and over time. In the
current study seizure susceptibility was quantified in a variety of mutant and
wild-type strains, and it was found that genetic mutations can modulate
susceptibility over an extremely wide range. This genetic modulation of seizure
susceptibility apparently occurs without affecting the threshold of individual
neurons. Seizure susceptibility also varied depending on the experience of the
fly, decreasing immediately after a seizure and then gradually increasing over
time. A novel phenomenon was also identified in which seizures are suppressed
after certain high-intensity stimuli. These results demonstrate the utility of
Drosophila as a model system for studying human seizure disorders and provide
insights into the possible mechanisms by which seizure susceptibility is
modified.
PMID- 10669512
TI - Altered regulation of potassium and calcium channels by GABA(B) and adenosine
receptors in hippocampal neurons from mice lacking Galpha(o).
AB - To examine the role of G(o) in modulation of ion channels by neurotransmitter
receptors, we characterized modulation of ionic currents in hippocampal CA3
neurons from mice lacking both isoforms of Galpha(o). In CA3 neurons from
Galpha(o)(-/-) mice, 2-chloro-adenosine and the GABA(B)-receptor agonist baclofen
activated inwardly rectifying K(+) currents and inhibited voltage-dependent
Ca(2+) currents just as effectively as in Galpha(o)(+/+) littermates. However,
the kinetics of transmitter action were dramatically altered in Galpha(o)(-/-)
mice in that recovery on washout of agonist was much slower. For example,
recovery from 2-chloro-adenosine inhibition of calcium current was more than
fourfold slower in neurons from Galpha(o)(-/-) mice [time constant of 12.0 +/-
0.8 (SE) s] than in neurons from Galpha(o)(+/+) mice (time constant of 2.6 +/-
0.2 s). Recovery from baclofen effects was affected similarly. In neurons from
control mice, effects of both baclofen and 2-chloro-adenosine on Ca(2+) currents
and K(+) currents were abolished by brief exposure to external N-ethyl-maleimide
(NEM). In neurons lacking Galpha(o), some inhibition of Ca(2+) currents by
baclofen remained after NEM treatment, whereas baclofen activation of K(+)
currents and both effects of 2-chloro-adenosine were abolished. These results
show that modulation of Ca(2+) and K(+) currents by G protein-coupled receptors
in hippocampal neurons does not have an absolute requirement for Galpha(o).
However, modulation is changed in the absence of Galpha(o) in having much slower
recovery kinetics. A likely possibility is that the very abundant Galpha(o) is
normally used but, when absent, can readily be replaced by G proteins with
different properties.
PMID- 10669513
TI - Dynamic properties of recurrent inhibition in primary visual cortex: contrast and
orientation dependence of contextual effects.
AB - A fundamental feature of neural circuitry in the primary visual cortex (V1) is
the existence of recurrent excitatory connections between spiny neurons,
recurrent inhibitory connections between smooth neurons, and local connections
between excitatory and inhibitory neurons. We modeled the dynamic behavior of
intermixed excitatory and inhibitory populations of cells in V1 that receive
input from the classical receptive field (the receptive field center) through
feedforward thalamocortical afferents, as well as input from outside the
classical receptive field (the receptive field surround) via long-range
intracortical connections. A counterintuitive result is that the response of
oriented cells can be facilitated beyond optimal levels when the surround
stimulus is cross-oriented with respect to the center and suppressed when the
surround stimulus is iso-oriented. This effect is primarily due to changes in
recurrent inhibition within a local circuit. Cross-oriented surround stimulation
leads to a reduction of presynaptic inhibition and a supraoptimal response,
whereas iso-oriented surround stimulation has the opposite effect. This mechanism
is used to explain the orientation and contrast dependence of contextual
interactions in primary visual cortex: responses to a center stimulus can be both
strongly suppressed and supraoptimally facilitated as a function of surround
orientation, and these effects diminish as stimulus contrast decreases.
PMID- 10669514
TI - Regional differences in hypoxic depolarization and swelling in hippocampal
slices.
AB - Pyramidal neurons in the CA1 region of the hippocampus are highly vulnerable to
damage from hypoxia-ischemia, whereas neurons in the CA3 region and the dentate
gyrus are more resistant. A similar pattern of vulnerability to loss of synaptic
and membrane function occurs in the in vitro hippocampal slice preparation,
suggesting that intrinsic factors are important in acute neuronal damage.
Simultaneous recordings of DC potential and imaging of changes in light
transmittance were made in slices from the middle one-third of the hippocampus to
characterize the initiation and spread of depolarization and swelling during
hypoxia-aglycemia. Hypoxic depolarization (HD) and associated optical changes
were initiated simultaneously in the stratum oriens of the CA1 region and
thereafter spread to the stratum radiatum of CA1 and later to the upper (inner)
blade of the dentate gyrus. A decrease in light transmittance was associated
consistently with depolarization in all regions (n = 22 slices). Investigation of
the sequence of activation in intact slices showed that activation of the dentate
gyrus arose independently of activation of the CA1 region. This was confirmed by
recordings made from minislices in which CA1, CA3, and dentate regions were
physically separated. HD and optical changes were never observed in the CA3
region, despite exposure to 40-60 min of combined hypoxia and aglycemia. In
contrast, exposure to hypoxia after pretreatment of slices with altered tonicity
or ion composition, which triggered episodes of spreading depolarization (SD),
provoked depolarization and optical changes simultaneously in both CA1 and CA3
regions. Similarly, pretreatment with agents that cause severe metabolic
impairment, such as dinitrophenol (DNP), also rendered the CA3 region vulnerable
to subsequent hypoxia. This suggests that the CA3 region in hippocampal slices is
normally resistant to HD and only becomes vulnerable after severe impairment of
metabolic capacity. The similar order of vulnerability of in vitro and in vivo
hippocampus to hypoxia-aglycemia supports the use of the hippocampal slice
preparation to investigate early changes potentially contributing to hypoxic
ischemic injury.
PMID- 10669515
TI - Spatial distribution and characteristics of voltage-gated calcium signals within
visual interneurons.
AB - Most of our knowledge about insect calcium currents is derived from studies on
cultured or dissociated somata. So far, only little data on calcium currents are
available for neurons including their dendritic and presynaptic structures. Here
we combined the switched-electrode voltage-clamp technique with optical recording
using calcium-sensitive dyes in identified fly visual interneurons in vivo to
characterize the voltage dependence and dynamics of calcium currents
quantitatively and in a spatially resolved way. For all three cell types
considered, i.e., centrifugal horizontal (CH), horizontal system (HS), and
vertical system (VS) cells, the activation curve is rather flat and covers a
voltage range from -60 to -20 mV in dendritic as well as presynaptic areas of the
cells. The calcium increase is fastest for CH cells with a time constant of
approximately 70 ms. In HS and VS cells, the time constant amounts to 400-700 ms.
The calcium dynamics as determined in different regions of the cells are similar
except for a small segment between the axon and the dendrite in HS and VS cells,
where the calcium increase is significantly faster. In summary, the results show
the existence of a low-voltage-activated calcium current with little or no
inactivation in dendritic as well as presynaptic regions of fly lobula plate
tangential cells.
PMID- 10669516
TI - Mapping of IP(3)-mediated Ca(2+) signals in single human neuroblastoma SH-SY5Y
cells: cell volume shaping the Ca(2+) signal.
AB - Fast confocal laser-scanning microscopy was used to study spatiotemporal
properties of IP(3)-mediated Ca(2+) release signals in human SH-SY5Y
neuroblastoma cells. [Ca(2+)](i) increases were not affected by ryanodine (30
microgM) or caffeine (10 mM) and largely insensitive to removal of external
Ca(2+), indicating predominance of IP(3)-induced Ca(2+) release. Ca(2+) signals
evoked by high concentration (10 microM) of the muscarinic agonist carbachol
appeared as self-propagating waves initiating in cell processes. At low carbachol
concentrations (500 nM) Ca(2+) changes in most cells displayed striking
spatiotemporal heterogeneity. The Ca(2+) response in the cell body was delayed
and had a smaller amplitude and a slower rise time than that in processes. Ca(2+)
changes in processes either occurred in a homogeneous manner throughout the whole
process or were sometimes confined to hot spots. Regional differences in surface
to-volume ratio appear to be critical clues that determine the spatiotemporal
pattern of intracellular Ca(2+) release signals.
PMID- 10669517
TI - Lateralized tinnitus studied with functional magnetic resonance imaging: abnormal
inferior colliculus activation.
AB - Tinnitus, the perception of sound in the absence of external stimuli, is a common
and often disturbing symptom that is not understood physiologically. This paper
presents an approach for using functional magnetic resonance imaging (fMRI) to
investigate the physiology of tinnitus and demonstrates that the approach is
effective in revealing tinnitus-related abnormalities in brain function. Our
approach as applied here included 1) using a masking noise stimulus to change
tinnitus loudness and examining the inferior colliculus (IC) for corresponding
changes in activity, 2) separately considering subpopulations with particular
tinnitus characteristics, in this case tinnitus lateralized to one ear, 3)
controlling for intersubject differences in hearing loss by considering only
subjects with normal or near-normal audiograms, and 4) tailoring the experimental
design to the characteristics of the tinnitus subpopulation under study. For
lateralized tinnitus subjects, we hypothesized that sound-evoked activation would
be abnormally asymmetric because of the asymmetry of the tinnitus percept. This
was tested using two reference groups for comparison: nontinnitus subjects and
nonlateralized tinnitus subjects. Binaural noise produced abnormally asymmetric
IC activation in every lateralized tinnitus subject (n = 4). In reference
subjects (n = 9), activation (i.e., percent change in image signal) in the right
versus left IC did not differ significantly. Compared with reference subjects,
lateralized tinnitus subjects showed abnormally low percent signal change in the
IC contralateral, but not ipsilateral, to the tinnitus percept. Consequently,
activation asymmetry (i.e., the ratio of percent signal change in the IC
ipsilateral versus contralateral to the tinnitus percept) was significantly
greater in lateralized tinnitus subjects as compared with reference subjects.
Monaural noise also produced abnormally asymmetric IC activation in lateralized
tinnitus subjects. Two possible models are presented to explain why IC activation
was abnormally low contralateral to the tinnitus percept in lateralized tinnitus
subjects. Both assume that the percept is associated with abnormally high
("tinnitus-related") neural activity in the contralateral IC. Additionally, they
assume that either 1) additional activity evoked by sound was limited by
saturation or 2) sound stimulation reduced the level of tinnitus-related activity
as it reduced the loudness of (i.e., masked) the tinnitus percept. In summary,
this work demonstrates that fMRI can provide objective measures of lateralized
tinnitus and tinnitus-related activation can be interpreted at a neural level.
PMID- 10669519
TI - Human cerebellum plays an important role in memory-timed finger movement: an fMRI
study.
AB - The purpose of this study was to determine, by using functional magnetic
resonance imaging, the areas of the brain activated during a memory-timed finger
movement task and compare these with those activated during a visually cued
movement task. Because it is likely that subjects engage in subvocalization
associated with chronometric counting to achieve accurate timing during memory
timed movements, the authors sought to determine the areas of the brain activated
during a silent articulation task in which the subjects were instructed to
reproduce the same timing as for the memory-timed movement task without any lip
movements or vocalization. The memory-timed finger movement task induced
activation of the anterior lobe of the cerebellum (lobules IV and V) bilaterally,
the contralateral primary motor area, the supplementary motor area (SMA), the
premotor area (PMA), the prefrontal cortex, and the posterior parietal cortex
bilaterally, compared with the resting condition. The same areas in the SMA and
left prefrontal cortex were activated during the silent articulation task
compared with the resting condition. The anterior lobe of the cerebellum on both
sides was also activated during the silent articulation task compared with the
resting condition, but these activations did not reach statistical significance
(P < 0.05 corrected). In addition, the anterior cerebellum on both sides showed
significant activation during the memory-timed movement task when compared with
the visually cued finger movement task. The visually cued finger movement task
specifically activated the ipsilateral PMA and the intraparietal cortex
bilaterally. The results indicate that the anterior lobe of the cerebellum of
both sides, the SMA, and the left prefrontal cortex were probably involved in the
generation of accurate timing, functioning as a clock within the CNS, and that
the dorsal visual pathway may be involved in the generation of visually cued
movements.
PMID- 10669520
TI - Characteristics of plateau activity during the latent period prior to
epileptiform discharges in slices from rat piriform cortex.
AB - The deep piriform region has an unusually high seizure susceptibility. Voltage
imaging previously located the sites of epileptiform discharge onset in slices of
rat piriform cortex and revealed the spatiotemporal pattern of development of two
types of electrical activity during the latent period prior to discharge onset. A
ramplike depolarization (onset activity) appears at the site of discharge onset.
Onset activity is preceded by a sustained low-amplitude depolarization (plateau
activity) at another site, which shows little if any overlap with the site of
onset. Because synaptic blockade at either of these two sites blocks discharges,
it was proposed that both forms of latent period activity are necessary for the
generation of epileptiform discharges and that the onset and plateau sites work
together in the amplification of electrical activity. The capacity for
amplification was examined here by studying subthreshold responses in slices of
piriform cortex using two different in vitro models of epilepsy. Under some
conditions electrically evoked responses showed a nonlinear dependence on
stimulus current, suggesting amplification by strong polysynaptic excitatory
responses. The sites of plateau and onset activity were mapped for different in
vitro models of epilepsy and different sites of stimulation. These experiments
showed that the site of plateau activity expanded into deep layers of neighboring
neocortex in parallel with expansions of the onset site into neocortex. These
results provide further evidence that interactions between the sites of onset and
plateau activity play an important role in the initiation of epileptiform
discharges. The site of plateau activity showed little variation with different
stimulation sites in the piriform cortex, but when stimulation was applied in the
endopiriform nucleus (in the sites of onset of plateau activity), plateau
activity had a lower amplitude and became distributed over a much wider area.
These results indicate that in the initiation of epileptiform discharges, the
location of the circuit that generates plateau activity is not rigidly defined
but can exhibit flexibility.
PMID- 10669518
TI - GABA(B) receptors couple to potassium and calcium channels on identified lateral
perforant pathway projection neurons.
AB - Activation of presynaptic GABA(B) receptors inhibits neurotransmitter release at
most cortical synapses, at least in part because of inhibition of voltage-gated
calcium channels. One synapse where this is not the case is the lateral perforant
pathway synapse onto dentate granule cells in the hippocampus. The current study
was conducted to determine whether the neurons that make these synapses express
GABA(B) receptors that can couple to ion channels. Perforant pathway projection
neurons were labeled by injecting retrograde tracer into the dorsal hippocampus.
The GABA(B) receptor agonist baclofen (10 microM) activated inwardly rectifying
potassium channels and inhibited currents mediated by voltage-gated calcium
channels in retrogradely labeled neurons in layer II of the lateral entorhinal
cortex. These effects were reversed by coapplication of the selective GABA(B)
receptor antagonist CGP 55845A (1 microM). Equivalent effects were produced by
100 microM adenosine, which inhibits neurotransmitter release at lateral
perforant pathway synapses. The effects of baclofen and adenosine on inward
currents were largely occlusive. These results suggest that the absence of
GABA(B) receptor-mediated presynaptic inhibition at lateral perforant pathway
synapses is not simply due to a failure to express these receptors and imply that
GABA(B) receptors can either be selectively localized or regulated at terminal
versus somatodendritic domains.
PMID- 10669521
TI - Saccade-related activity in the parietal reach region.
AB - In previous experiments, we showed that cells in the parietal reach region (PRR)
in monkey posterior parietal cortex code intended reaching movements in an eye
centered frame of reference. These cells are more active when an arm compared
with an eye movement is being planned. Despite this clear preference for arm
movements, we now report that PRR neurons also fire around the time of a saccade.
Of 206 cells tested, 29% had perisaccadic activity in a delayed-saccade task. Two
findings indicate that saccade-related activity does not reflect saccade planning
or execution. First, activity is often peri- or postsaccadic but seldom
presaccadic. Second, cells with saccade-related activity were no more likely to
show strong saccadic delay period activity than cells without saccade-related
activity. These findings indicate that PRR cells do not take part in saccade
planning. Instead, the saccade-related activity in PRR may reflect cross-coupling
between reach and saccade pathways that may be used to facilitate eye-hand
coordination. Alternatively, saccade-related activity may reflect eye position
information that could be used to maintain an eye-centered representation of
intended reach targets across eye movements.
PMID- 10669522
TI - Difference between visually and electrically evoked gaze saccades disclosed by
altering the head moment of inertia.
AB - Differences between gaze shifts evoked by collicular electrical stimulation and
those triggered by the presentation of a visual stimulus were studied in head
free cats by increasing the head moment of inertia. This maneuver modified the
dynamics of these two types of gaze shifts by slowing down head movements. Such
an increase in the head moment of inertia did not affect the metrics of visually
evoked gaze saccades because their duration was precisely adjusted to compensate
for these changes in movement dynamics. In contrast, the duration of electrically
evoked gaze shifts remained constant irrespective of the head moment of inertia,
and therefore their amplitude was significantly reduced. These results suggest
that visually and electrically evoked gaze saccades are controlled by different
mechanisms. Whereas the accuracy of visually evoked saccades is likely to be
assured by on-line feedback information, the absence of duration adjustment in
electrically evoked gaze shifts suggests that feedback information necessary to
maintain their metrics is not accessible or is corrupted during collicular
stimulation. This is of great importance when these two types of movements are
compared to infer the role of the superior colliculus in the control of orienting
gaze shifts.
PMID- 10669523
TI - Modulation of dendritic action currents decreases the reliability of population
spikes.
AB - During synchronous action potential (AP) firing of CA1 pyramidal cells, a
population spike (PS) is recorded in the extracellular space, the amplitude of
which is considered a reliable quantitative index of the population output.
Because the AP can be actively conducted and differentially modulated along the
soma and dendrites, the extracellular part of the dendritic inward currents
variably contributes to the somatic PS by spreading in the volume conductor to
adjacent strata. This contribution has been studied by current-source density
analysis and intracellular recordings in vivo during repetitive backpropagation
that induces their selective fading. Both the PS and the ensemble action currents
declined during high-frequency activation, although at different rates and
timings. The decline was much stronger in dendrites than in the somatic region.
At specific frequencies and for a short number of impulses the decrease of the
somatic PS was neither due to fewer firing cells nor to decreased somatic action
currents but to the blockade of dendritic action currents. The dendritic
contribution to the peak of the somatic antidromic PS was estimated at
approximately 30-40% and up to 100% at later times in the positive-going limb.
The blockade of AP dendritic invasion was in part due to a decreased transfer of
current from the soma that underwent a cumulative increase of conductance and
slow depolarization during the train that eventually extended into the axon. The
possibility of differential modulation of soma and dendritic action currents
during APs should be checked when using the PS as a quantitative parameter.
PMID- 10669524
TI - Early Life Influences and Interventions in Asthma. Introduction.
PMID- 10669525
TI - Prevalence and etiology of asthma.
AB - An increased understanding of the causes of asthma is coming from the
international comparisons of asthma prevalence, particularly those from the
European Community Respiratory Health Survey of asthma prevalence in adults and
the International Study of Asthma and Allergies in Childhood. From these and
other studies of asthma prevalence, it is possible to draw some tentative
conclusions as to the patterns of asthma prevalence worldwide. There are five
striking patterns: first, asthma prevalence is increasing worldwide; second,
asthma is generally more common in Western countries and less common in
developing countries; third, asthma is more prevalent in English-speaking
countries; fourth, asthma prevalence is increasing in developing countries as
they become more Westernized or communities become urbanized; and fifth, the
prevalence of other allergic disorders may also be increasing worldwide. These
five key features of the international patterns of asthma prevalence raise major
questions about the role of "established" risk factors for the development of
asthma. As a result, recent research has expanded to include the study of novel
factors that may "program" the initial susceptibility to sensitization or
contribute to the development of asthma independent of atopic sensitization.
These include various exposures in utero, which are reflected in various
perinatal factors measured at birth, and exposures (or lack of exposures) in the
early years of life that may make the infant more susceptible to the subsequent
development of asthma. These issues are now the focus of an intensive research
effort worldwide, and the next few years are likely to see exciting advances in
our understanding of the causes of asthma.
PMID- 10669526
TI - Issues in understanding childhood asthma.
AB - Asthma and related allergic disorders in childhood have increased considerably in
prevalence over the last few decades. During the same period of increasing
morbidity from childhood asthma in the community, there have been dramatic
advances in understanding of the basic immunopathologic features of the disease
and consequently the development of a far more rational approach to its
treatment. The immunopathologic condition of eosinophil-mediated airway
inflammation is established very early in the evolution of asthma in childhood.
It may even antedate the onset of symptoms. The present state of the art dictates
that early intervention with potent therapies cannot be justified on the basis of
symptoms alone and may in any case have no influence on the natural history of
the condition. This means that current cautious therapeutic guidelines should
continue to be followed. However, with the development of more accurate markers
predicting ongoing disease, it will be possible to evaluate a whole range of
early interventions in the future. Much evidence, though indirect, points to the
possibility that the only true prophylaxis that will affect the natural history
of asthma will need to be commenced before clinical features are manifest.
PMID- 10669527
TI - Mapping susceptibility genes for asthma and allergy.
AB - Allergy and asthma are related conditions caused by a complex interaction of
genetic factors and environmental influences. With family data from several
different populations, linkage analysis has been performed and used to identify
regions of the genome that contain susceptibility genes for these conditions. To
date, 4 genome screens have been completed and have successfully identified
several chromosomal locations that are likely to contain asthma and allergy
genes. Many of these regions contain potential biologic candidate genes that
modulate immunologic responses or airways inflammation. By focusing on the common
regions that have been replicated in these 4 genome screens, the major
susceptibility genes for asthma and allergy should be identified. This will lead
to an improved understanding of pathogenic factors that lead to development or
progression of asthma and allergic diseases.
PMID- 10669528
TI - Strategies for analyzing genotype-phenotype relationships in asthma.
AB - Asthma is a genetically complex disease with a multifaceted phenotype. Different
approaches including population-based and family-based methods for evaluating
genotype-phenotype relationships in asthma are discussed as well as the problems
that may obscure these determinations. Examples of similar efforts in cystic
fibrosis and breast cancer are considered in addition to interaction between
causative genes and etiologically relevant environmental exposure.
PMID- 10669529
TI - The pharmacogenetics of beta2-adrenergic receptors: relevance to asthma.
AB - The beta(2)-adrenergic receptor (beta(2)AR) is the molecular target for beta
agonists used in the treatment of asthma. In the human population, 4
polymorphisms of the beta(2)AR coding block have been found, 3 of which result in
receptors that have different properties compared with wild-type. To date,
clinical studies suggest that these beta(2)AR polymorphisms may alter asthmatic
phenotype and the response to beta-agonist therapy, making these variants the
first of undoubtedly several genetic loci that will ultimately be found that will
provide for individualized therapy in asthma.
PMID- 10669530
TI - Prenatal origins of allergic disease.
AB - The prevalence of asthma and related allergic disorders has increased
considerably over the last 25 years. Because genetic stock has not changed,
environmental factors must have influenced the phenotype. Infants who experience
the development of allergy already have an altered immune response at birth. We
have investigated the development of immune responses during gestation and the
effect of maternal allergen exposure during pregnancy and infant exposure in the
first month of life on the development of allergy and disease. There was higher
specific peripheral blood mononuclear cell proliferation to house dust mite and
birch pollen in the third trimester compared with the second trimester, with the
first positive responses seen at 22 weeks gestation. Maternal exposure to birch
pollen after 22 weeks resulted in higher infant peripheral blood mononuclear cell
responses to birch pollen at birth. Infants born at term, with at least 1 atopic
parent with asthma, who experienced the development of allergic symptoms and
positive skin prick test by 1 year of age had raised proliferative responses to
house dust mite at birth compared with those infants with no symptoms. In
genetically predisposed individuals, antenatal factors including maternal and
thereby fetal exposure to allergens and materno-placental-fetal immunologic
interactions are active in determining whether an allergic predisposition is
manifested as disease.
PMID- 10669531
TI - Viral and bacterial infections in the development and progression of asthma.
AB - Viral respiratory infections produce wheezing illnesses in patients of all ages.
In infancy, infections with respiratory syncytial virus and parainfluenza virus
are the major cause of bronchiolitis and croup, whereas infections with common
cold viruses such as rhinoviruses are the principal triggers for wheezing in
older children and adults with asthma. In addition to causing increased wheezing
in asthma, there is mounting evidence that infections early in childhood can
affect the development of the immune system and thereby modify the risk for the
subsequent development of allergies and asthma. Both of these effects appear to
be mediated by virus-induced immune responses. Early during the course of viral
infection, resident cells in the airway are activated in an antigen-independent
fashion, triggering antiviral responses but also activating and recruiting cells
to the airway that could contribute to airway obstruction and respiratory
symptoms. Virus-specific T- and B-cell responses may also have dual effects in
the presence of preexisting airway inflammation. Finally, there is evidence of
synergistic interactions between allergen- and virus-induced airway inflammation.
It is likely that greater definition of mechanisms of virus-induced inflammation
will provide therapeutic targets for the treatment and possibly the prevention of
allergies and asthma.
PMID- 10669532
TI - The relevance of allergen exposure to the development of asthma in childhood.
AB - Sensitization to 1 or more of the common indoor allergens has been consistently
associated with asthma among children and young adults (odds ratios for asthma, 3
18). For dust mite and cockroach allergens, there is a dose response relationship
between domestic exposure and sensitization. Given that allergen provocation can
induce many of the features of asthma, the findings strongly suggest that there
is a causal relationship between allergen exposure in the home and asthma.
However, it remains unclear at what time the critical exposure occurs (ie, in
infancy or later) and what role allergen exposure has played in the increasing
prevalence and severity of asthma. Objective evidence of an immune response to
allergens is generally not present until after 2 years of age. Viral infections
play several different roles in asthma in childhood. In infancy, respiratory
syncytial virus infection can induce bronchiolitis and set up recurrent wheezing
over the next few years. However, the risk factors for this are maternal smoking
and small lungs at birth, rather than allergy. By contrast, the role of
rhinovirus in precipitating attacks in children and young adults is strongly
associated with allergy. Thus the likely scenario is that allergen exposure over
the first few years of life induces sensitization (ie, T(H2) cells and IgE
antibodies). Continuing exposure can maintain inflammation in the nose and lungs.
However, many other factors contribute to wheezing such that there is no simple
relationship between allergen exposure and asthma. Nonetheless, it is clear that
the changes that have increased asthma have acted on allergic children.
PMID- 10669533
TI - Histopathologic features of early and progressive asthma.
AB - During the last decade, morphologic studies on bronchial biopsy specimens have
led to our present understanding of asthma as an inflammatory airways disease.
However, little knowledge exists about the sequence of cellular events during the
disease or of possible mucosal changes early in asthma. So far the primary cause,
the site of damage, and the mechanisms inducing the inflammatory reaction remain
to be elucidated. A multifactorial genetic susceptibility may be important for
the development of asthma. Suggested factors that may trigger changes in the
cells' morphologic and functional phenotype are viral infections, allergen
exposure, maternal factors, diet, and smoking. Current evidence has implied that
interactions between epithelial cells and the subepithelial connective tissue in
the mucosa are important for normal homeostatic balance. Changes in airway
epithelial phenotype possibly resulting from altered gene expression in its
lining cells may be very important even as a first line change in asthma.
PMID- 10669534
TI - Structural consequences of airway inflammation in asthma.
AB - Asthma represents a chronic inflammatory process of the airways followed by
healing, the end-result of which is an altered structure referred to as a
remodeling of the airways. Repair usually involves 2 distinct processes:
regeneration (which is the replacement of injured tissue by parenchymal cells of
the same type) and replacement by connective tissue and its eventual maturation
into scar tissue. In many instances both processes contribute to the healing
response and inflammation. In asthma the processes of cell dedifferentiation,
migration, differentiation, and maturation and connective tissue deposition can
be followed either by complete or altered restitution of airway structure and
function, the latter often seen as fibrosis and increase in smooth muscle and
mucus gland mass. These features result in an increased resistance to airflow,
particularly when there is bronchial contraction and bronchial
hyperresponsiveness. The effect on airflow is compounded by the presence of
increased mucous secretion and inflammatory exudate, which not only blocks the
airway passages but also causes an increased surface tension that favors airway
closure.
PMID- 10669535
TI - The role of proteoglycans in the regulation of airways inflammation and airways
remodelling.
PMID- 10669536
TI - Asthma: A disease of inflammation and repair.
AB - Mucosal inflammation and more recently airway remodeling continue to be a focus
of interest when considering both the pathophysiology and treatment of asthma.
Although a number of candidate genes relevant to inflammatory cell action have
been identified and linked to atopy and airway hyperresponsiveness, it is
important to understand genetic factors that might determine the extent of tissue
remodeling. The mechanisms regulating the allergic responses in the airways are
complex, involving antigen presenting cells and T lymphocytes, which process
antigens and orchestrate the response, and mast cells and eosinophils as effector
cells. Abundant evidence also points to a proinflammatory role for structural
cells, including epithelial and endothelial cells, and smooth muscle. Because of
the complex nature of the inflammatory changes in asthma, the exact relation
between individual inflammatory cells and their mediators on the one hand and
hyperresponsiveness of the airways and clinical manifestations on the other
remains unclear. The same applies to the phenomenon of airway remodeling because
it is uncertain exactly how the different components of restructuring affect the
airway physiology. If progress is to be made in the treatment of asthma, further
efforts will be needed to understand the regulation and link between the
mechanisms causing inflammation and those leading to fibrotic changes.
PMID- 10669537
TI - Mast-cell responses in the development of asthma.
AB - Many cells participate in the pathogenesis of asthmatic inflammation. The mast
cell is localized at the interface of the internal and external environment
within the lung where it may respond to allergens and other exogenous stimuli.
The activation of mast cells leads to the release of mediators that contribute to
the early phase of asthmatic inflammation. Mast-cell-derived products may also
contribute to the late-phase asthmatic response. This review summarizes the
developmental biologic features of the mast cell, its receptor-mediated
activation, and its range of preformed, newly synthesized, and induced mediators
that contribute to asthmatic inflammation.
PMID- 10669538
TI - Natural history of chronic asthma and its long-term effects on pulmonary
function.
AB - Although asthma is a disease that has intrigued physicians since antiquity, its
natural history has been incompletely determined. It has long been held that the
presence of asthma, per se, does not carry with it any long-term deterioration in
lung function, but recently this view has been challenged, and it has become
fashionable to define asthma as being only partially reversible. At present,
there are limited data to support such a view. All of the available information
indicates that the vast majority of patients do not experience the development of
a progressive decline in pulmonary mechanics or appear to be at risk for a
diminution in life expectancy.
PMID- 10669539
TI - Interaction between the growing lung and asthma: role of early intervention.
AB - Asthma is a syndrome where an imbalance exists between the forces that maintain
airway patency and the forces that act to narrow, or close, airways. The child
with asthma is a particular problem because of the rapid growth of the lung
during growth that leaves it vulnerable. There is some evidence that asthma leads
to impaired lung function in children because those children with untreated
asthma show a loss of lung growth velocity. For unclear reasons, asthma is more
frequent in boys. What drugs to use to treat childhood asthma is uncertain. Data
show that glucocorticoids prevent the structure of the lung from fully
developing. In children, the rationale for early intervention seems clear, but
the exact means and criteria for initiation of the intervention are uncertain.
Finally, childhood asthma raises fundamental issues and questions that are unique
to the child with asthma and presents unique and many unresolved treatment
dilemmas.
PMID- 10669540
TI - Molecular mechanisms of IgE regulation.
AB - IgE antibody plays an important role in allergic diseases. IgE synthesis by B
cells requires two signals. The first signal is delivered by the cytokines IL-4
or IL-13, which target the Cepsilon gene for switch recombination. The second
signal is delivered by interaction of the B cell surface antigen CD40 with its
ligand (CD40L) expressed on activated T cells. This activates deletional switch
recombination. We review the molecular mechanisms of IL-4 and CD40 signaling that
lead to IgE isotype switching and discuss the implications for intervening to
abort or suppress the IgE antibody response.
PMID- 10669541
TI - The consideration of immunotherapy in the treatment of allergic asthma.
AB - Immunotherapy has undergone rigorous trials to assess its therapeutic benefit in
the treatment of allergic respiratory disease. The tools of molecular biology
have provided a framework with which to begin to understand the mechanistic
effects of immunotherapy on the underlying inflammatory component of allergic
respiratory disease. The clinical relevance of these observations belies our
understanding of allergic inflammation as the subsoil for the development of
abnormal airway physiology, heightened bronchial reactivity, and the development
of chronic asthmatic symptoms. Immunotherapy provides the potential to
downregulate this inflammatory cascade, reduce IgE antibody production, and
attenuate symptoms. Conceptually, early intervention of allergic disease holds
the most promise as a therapeutic intervention capable of arresting the
progression of the disease, altering the severity of the disease, and/or
preventing the development of the respiratory disease process.
PMID- 10669542
TI - The effects of cromolyn sodium and nedocromil sodium in early asthma prevention.
AB - The possibility of irreversible obstruction and therefore the need for early
intervention is being much debated. Some investigators suggested that delay in
starting inhaled corticosteroids will result in irreversible obstruction. Our own
long-term study, specifically designed to detect irreversible obstruction showed
that a step-wise approach (starting with cromolyn sodium and switching to inhaled
corticosteroids if clinical control and pulmonary function tests are not
satisfactorily controlled) resulted in an increase in pulmonary function and not
a deterioration. There was no evidence that a delay in starting inhaled
corticosteroids will result in irreversible obstruction or clinical worsening.
However, delay in starting cromolyn sodium in patients treated with
bronchodilators alone did result in worsening pulmonary function tests and worse
clinical outcomes. One study from Finland and another study from Australia came
to the same conclusion. Even though some studies with cromolyn sodium did not
show benefit in the first year of life, other studies did show a good response.
The choice between nonsteroidal drugs, such as cromolyn sodium and inhaled
corticosteroids as first-line drugs, has to be made on the risk/benefit ratio of
these drugs. Although in severe asthma inhaled corticosteroids have greater
efficacy, in mild-to-moderate asthma there is comparable efficacy, and the
nonsteroidal drugs have better safety. A step-wise approach is still a logical
approach
PMID- 10669543
TI - Early interventions in asthma with inhaled corticosteroids.
AB - We have earlier shown epithelial damage in the airway mucosa in patients with
asthma. Later other structural changes have been recognized in asthma, such as
deposition of collagen and tenascin in the subepithelial basement membrane and
changes in the laminin subchain composition. These processes are modified by an
inflammatory process in the airways. Both the United States National Institutes
of Health and the British Thoracic Society guidelines on the management of asthma
emphasize the need for early use of anti-inflammatory drugs. Many clinical
studies that used airway biopsy specimens have shown a decrease in airway
inflammatory cell numbers after inhaled corticosteroid therapy. However, there is
very little information on the effects of asthma medication on the structural
components of the airways. Both the synthesis and degradation of many
extracellular matrix components may be affected by the disease process and the
drugs resulting in altered remodeling and gene expression in the airways. Because
there are only a few studies that try to identify early changes in asthma, it is
not known whether the anti-inflammatory treatment of asthma proposed by the
guidelines is started early enough.
PMID- 10669544
TI - New immunopharmacologic approaches to asthma: role of cytokine antagonism.
AB - This article involves an elucidation of the potential inflammatory mechanisms
associated with the treatment of allergic disease and asthma, and the possibility
of cytokine antagonism as a potential therapeutic mechanism for the treatment of
those diseases. There is a review of the role of cytokines in the allergic
process and a description of a number of studies done with the capacity of
certain cytokine antagonists to develop potential amelioration of immune
dysregulation in asthma and atopic states.
PMID- 10669545
TI - Signal transduction and cellular radiation responses.
AB - Exposure of cells to ionizing radiation results in complex cellular responses
resulting in cell death and altered proliferation states. The underlying
cytotoxic, cytoprotective and cellular stress responses to radiation are mediated
by existing signaling pathways, activation of which may be amplified by intrinsic
cellular radical production systems. These signaling responses include the
activation of plasma membrane receptors, the stimulation of cytoplasmic protein
kinases, transcriptional activation, and altered cell cycle regulation. From the
data presented, there is increasing evidence for the functional links between
cellular signal transduction responses and DNA damage recognition and repair,
cell survival, or cell death through apoptosis or reproductive mechanisms.
PMID- 10669546
TI - Alpha-particle-induced changes in the stability and size of DNA.
AB - The effect of alpha-particle radiation on the thermal stability and size of calf
thymus DNA molecules in deoxygenated aqueous solutions was investigated by
thermal transition spectrophotometry, pulsed-field gel electrophoresis, and
standard agarose gel electrophoresis. The thermal transition of DNA from helix to
coil was studied through analysis of the UV A(260) absorbance. The results
obtained for alpha particles of mean LET of 128 keV microm(-1) reveal a dual dose
response: a tendency for thermal stability of the DNA helix at "low" doses,
followed by an increasing instability at higher doses. The same phenomenon was
observed for the mean molecular weight of DNA molecules exposed to alpha
particles. The results reported here for alpha particles in the low-dose region
of 0-16 Gy are consistent with our previous hypothesis of inter- and
intramolecular interactions of a covalent character in gamma-irradiated DNA
molecules in the dose region of 0-4 Gy.
PMID- 10669547
TI - Iodine-125 decay in a synthetic oligodeoxynucleotide. I. Fragment size
distribution and evaluation of breakage probability.
AB - Lobachevsky, P. N. and Martin, R. F. Iodine-125 Decay in a Synthetic
Oligodeoxynucleotide. I. Fragment Size Distribution and Evaluation of Breakage
Probability. Incorporation of (125)I-dC into a defined location of a double
stranded oligodeoxynucleotide was used to investigate DNA breaks arising from
decay of the Auger electron-emitting isotope. Samples of the oligodeoxynucleotide
were also labeled with (32)P at either the 5' or 3' end of either the (125)I-dC
containing (so-called top) or opposite (bottom) strand and incubated in 20 mM
phosphate buffer or the same buffer plus 2 M dimethylsulfoxide at 4 degrees C
during 18-20 days. The (32)P-end-labeled fragments produced by (125)I decays were
separated on denaturing polyacrylamide gels, and the (32)P activity in each
fragment was determined by scintillation counting after elution of fragments from
the gel. The relative fragment size distributions were then normalized on a per
decay basis and converted to a distribution of single-strand break probabilities
as a function of distance from the (125)I-dC. The results of three to five
experiments for each of eight possible combinations of labels and incubation
conditions are presented as a table showing the relative numbers of (32)P counts
in different fragments as well as graphs of normalized fragment size
distributions and probabilities of breakage. The average numbers of single-strand
breaks per (125)I decay are 3. 3 and 3.7 in the top strand and 1.3 and 1.5 in the
bottom strand with and without dimethylsulfoxide, respectively. Every (125)I
decay event produces a break in the top strand, and breakage of the bottom strand
occurs in 75-80% of the events. Thus a double-strand break is produced by (125)I
decay with a probability of approximately 0.8.
PMID- 10669548
TI - Iodine-125 decay in a synthetic oligodeoxynucleotide. II. The role of auger
electron irradiation compared to charge neutralization in DNA breakage.
AB - Lobachevsky, P. N. and Martin, R. F. Iodine-125 Decay in a Synthetic
Oligodeoxynucleotide. II. The Role of Auger Electron Irradiation Compared to
Charge Neutralization in DNA Breakage. The dramatic chemical and biological
effects of the decay of DNA-incorporated (125)I stem from two consequences of the
Auger electron cascades associated with the decay of the isotope: high local
deposition of radiation energy from short-range Auger electrons, and
neutralization of the multiply charged tellurium atom. We have analyzed the
extensive data reported in the companion paper (Radiat. Res. 153, 000-000, 2000),
in which DNA breakage was measured after (125)I decay in a 41-bp oligoDNA. The
experimental data collected under scavenging conditions (2 M dimethylsulfoxide)
were deconvoluted into two components denoted as radiation and nonradiation, the
former being attributed to energy deposition by Auger electrons. The contribution
of the components was estimated by adopting various assumptions, the principal
one being that DNA breakage due to the radiation mechanism is dependent on the
distance between the decaying (125)I atom and the cleaved deoxyribosyl unit,
while the nonradiation mechanism, associated with neutralization of the multiply
charged tellurium atom, contributes equally at corresponding nucleotides starting
from the (125)I-incorporating nucleotide. Comparison of the experimental data
sets collected under scavenging and nonscavenging (without dimethylsulfoxide)
conditions was used to estimate the radiation-scavengeable component. Our
analysis showed that the nonradiation component plays the major role in causing
breakage within 4-5 nucleotides from the site of (125)I incorporation and
produces about 50% of all single-stranded breaks. This overall result is
consistent with the relative amounts of energy associated with Auger electrons
and the charged tellurium atom. However, the nonradiation component accounts for
almost four times more breaks in the top strand, to which the (125)I is bound
covalently, than in the bottom strand, thus suggesting an important role of
covalent bonds in the energy transfer from the charged tellurium atom. The
radiation component dominates at the distances beyond 8-9 nucleotides, and 36% of
the radiation-induced breaks are scavengeable.
PMID- 10669549
TI - Inducible repair and intrinsic radiosensitivity: a complex but predictable
relationship?
AB - Two groups have proposed a simple linear relationship between inducible
radioresistance in a variety of mammalian cells and their intrinsic
radiosensitivity at 2 Gy (Lambin et al., Int.J. Radiat. Biol. 69, 279-290, 1996;
Alsbeih and Raaphorst, unpublished results, 1997). The inducible repair response
(IRR) is quantified as a ratio, alpha(S)/alpha(R), i.e. the slope in the
hypersensitive low-dose region, alpha(S), relative to the alpha(R) term of the
classical linear-quadratic formula. These proposals imply that the intrinsic
radiosensitivity at clinically relevant doses is directly linked to the cell's
ability to mount an adaptive response as a result of exposure to very low doses
of radiation. We have re-examined this correlation and found that the more
extensive data set now available in the literature does not support the
contention of a simple linear relationship. The two parameters are correlated,
but by a much more complex relationship. A more logical fit is obtained with a
log-linear equation. A series of log-linear curves are needed to describe the
correlation between IRR and SF2, because of the spectrum of alpha/beta ratios
among the cell lines and hence the confounding effect of the beta term at a dose
of 2 Gy. The degree of repair competence before irradiation starts could also be
a major factor in the apparent magnitude of the amount of repair induced. There
appears to be a systematic difference in the data sets from different series of
cell lines that have been obtained using flow cytometry techniques in the
laboratory in Vancouver and using dynamic microscope imaging at the Gray
Laboratory. We suggest that the use of a brief exposure to a laser beam in flow
cytometry before the cells are irradiated might itself partially induce a stress
response and change the DNA repair capacity of the cells. The clinical
consequences of the relationship for predicting the benefits of altered
fractionation schedules are discussed. [ru5]
PMID- 10669550
TI - Radiation dose dependences in the atomic bomb survivor cancer mortality data: a
model-free visualization.
AB - Chomentowski, M., Kellerer, A. M. and Pierce, D. A. Radiation Dose Dependences in
the Atomic Bomb Survivor Cancer Mortality Data: A Model-Free Visualization. The
standard approach to obtaining nominal risk coefficients for radiation-related
cancer involves fitting linear or linear-quadratic dose-response functions. This
is usually complemented by a more direct visualization where the data are
subdivided into distinct dose categories and the effect level is quantified for
each of these categories. Such model-free computations, however, can be quite
dependent on the arbitrary choice of the cutpoints in dose. The method proposed
here largely avoids this arbitrariness by choosing a dose category width-constant
on a log scale-to obtain the desired degree of smoothing, and then superimposing
results for all placements of the resulting log-dose grids. The method is applied
to leukemia and solid cancer mortality of the A-bomb survivors.
PMID- 10669551
TI - Apoptosis and cell cycle progression in an acidic environment after irradiation.
AB - Apoptosis and cell cycle progression in HL60 cells irradiated in an acidic
environment were investigated. Apoptosis was determined by TUNEL staining, PARP
cleavage, DNA fragmentation, and flow cytometry. The majority of the apoptosis
that occurred in HL60 cells after 4 Gy irradiation took place after G(2)/M-phase
arrest. When irradiated with 12 Gy, a fraction of the cells underwent apoptosis
in G(1) and S phases while the rest of the cells underwent apoptosis in G(2)/M
phase. The apoptosis caused by 4 and 12 Gy irradiation was transiently suppressed
in medium at pH 7.1 or lower. An acidic environment was found to perturb
progression of irradiated cells through the cell cycle, including progression
through G(2)/ M phase. Thus it was concluded that the suppression of apoptosis in
the cells after 4-12 Gy irradiation in acidic medium was due at least in part to
a delay in cell cycle progression, particularly the prolongation of G(2)/M-phase
arrest. Irradiation with 20 Gy indiscriminately caused apoptosis in all cell
cycle phases, i.e. G(1), S and G(2)/M phases, rapidly in neutral pH medium and
relatively slowly in acidic pH medium. The delay in apoptosis in acidic medium
after 20 Gy irradiation appeared to result from mechanisms other than prolonged
G(2)/ M-phase arrest.
PMID- 10669552
TI - Dose-dependent biphasic accumulation of TP53 protein in normal human embryo cells
after X irradiation.
AB - The effects of various doses of X radiation on the kinetics of accumulation of
TP53 protein (formerly known as p53) were examined in normal human embryo cells.
We found that the rate of accumulation of TP53 protein was biphasic at X-ray
doses between 1 and 4 Gy, while monophasic accumulation was observed after X
irradiation with doses higher than 6 Gy. The first phase of accumulation was
detected within 1 h after irradiation, and a second phase of accumulation was
detected between 6 and 12 h after irradiation. The induction of CDKN1A (formerly
known as p21(WAF1/CIP1)) and MDM2 proteins was also biphasic after doses of 4 Gy
or less, while monophasic accumulation was observed after 6 Gy or higher. We
found that the proteasome inhibitor ALLN increased the constitutive level of TP53
protein, and no change was observed in the TP53 level after X irradiation when
cells were treated with ALLN. These results indicate that the dose-dependent
accumulation of TP53 is due to an inhibition of TP53 degradation, and that the
induction of MDM2 might be responsible in part for the different kinetics of
accumulation of TP53.
PMID- 10669553
TI - Dose-dependent changes in the spectrum of mutations induced by ionizing
radiation.
AB - We examined the influence of dose on the spectrum of mutations induced at the
hypoxanthine guanine phosphoribosyltransferase (Hprt) locus in Chinese hamster
ovary (CHO) cells. Independent CHO-K1 cell mutants at the Hprt locus were
isolated from cells exposed to 0, 0.5, 1.5, 3.0 and 6.0 Gy (137)Cs gamma rays,
and the genetic changes responsible for the mutations were determined by
multiplex polymerase chain reaction (PCR)-based exon deletion analysis. We
observed dose-dependent changes in mutation spectra. At low doses, the principal
radiation-induced mutations were point mutations. With increasing dose, multibase
deletion mutations became the predominant mutation type such that by 6.0 Gy,
there were almost three times more deletion mutations than point mutations. The
dose response for induction of point mutations was linear while that for
multibase deletions fit a linear-quadratic response. There was a biphasic
distribution of deletion sizes, and different dose responses for small compared
to large deletions. The frequency of large (>36 kb) total gene deletions
increased exponentially, implying that they develop from the interaction between
two independent events. In contrast, the dose response for deletion mutations of
less than 10 kb was nearly linear, suggesting that these types of mutations
develop mostly from single events and not the interactions between two
independently produced lesions. The observation of dose-dependent changes in
radiation-induced mutation spectra suggests that the types of alterations and
therefore the risks from low-dose radiation exposure cannot be easily
extrapolated from high-dose effects.
PMID- 10669554
TI - Inducible heat-shock protein 70 is involved in the radioadaptive response.
AB - Park, S-H., Lee, S-J., Chung, H-Y., Kim, T-H., Cho, C-K., Yoo, S-Y. and Lee, Y-S.
Inducible Heat-Shock Protein 70 Is Involved in the Radioadaptive Response. The
thermoresistant (TR) clone of radiation-induced fibrosarcoma (RIF) cells showed
an adaptive response, i.e. a reduced effect, after exposure to a higher
challenging dose (4 Gy) when the priming dose (1 cGy) was given 4 or 7 h earlier,
but RIF cells did not. Since inducible Hsp70 expression was different in cells of
these two cell lines, the role of inducible Hsp70 in the adaptive response was
examined. When inducible Hsp70 was transfected into RIF cells, the adaptive
response was acquired. Transfection of inducible Hsp70 to NIH 3T3 mouse embryo
cells also conferred radioresistance to the cells as assayed by clonogenic
survival, [(3)H]thymidine incorporation, and an ELISA cell death detection kit.
An increased tendency for the induction of an adaptive response was also
observed. Interestingly, basal levels of Ca(2+)-dependent and independent Pkc
activities were increased by transfection with inducible Hsp70 compared to those
of control vector cells. Irradiation with gamma rays induced activation of Pkc
within minutes in control vector cells, while transfection with inducible Hsp70
did not. Cellular redistribution to particulate fractions of Pkca, d and z after
exposure gamma rays also was not detected. Furthermore, radioresistance by
transfection with inducible Hsp70, as tested by clonogenic survival, disappeared
after pretreatment with Pkc inhibitors, 1-(5-isoquinolinesulfonyl)-2
methylpiperazine (H7), prolonged treatment with 12-O-tetradecanoylphorbol-13
acetate (TPA), and GF109203X. Taken together, these data suggest that
radioresistance inducible by Hsp70 is associated with an elevated level of Pkc
activity.
PMID- 10669555
TI - Effect of a combination of mild-temperature hyperthermia and nicotinamide on the
radiation response of experimental tumors.
AB - Ogawa, A., Griffin, R. J. and Song, C. W. Effect of a Combination of Mild
Temperature Hyperthermia and Nicotinamide on the Radiation Response of
Experimental Tumors. The effect of mild-temperature hyperthermia and nicotinamide
individually or combined on tumor radiosensitivity was investigated with SCK
tumors grown s.c. in the right hind limbs of A/J mice. An i.p. injection of
nicotinamide at 50-250 mg/kg slightly enhanced the cell killing caused by 10-20
Gy of ionizing radiation as determined by the in vivo/in vitro tumor excision
assay. Treatment of tumors with mild-temperature hyperthermia at 41.5 degrees C
for 60 min prior to tumor irradiation was significantly more effective than
nicotinamide and the combination of nicotinamide and hyperthermia was far more
effective than nicotinamide or hyperthermia alone in enhancing radiation-induced
cell killing. Radiation-induced tumor growth delay was enhanced by a factor of
1.2 by 50 mg/kg nicotinamide, 2.1 by hyperthermia, and 3.6 by the combination of
nicotinamide and hyperthermia. Taking these results and those of our previous
studies together, we conclude that mild-temperature hyperthermia increases tumor
blood flow and oxygenation and that combining mild-temperature hyperthermia and
nicotinamide is more effective than either of these alone in increasing tumor
radiosensitivity.
PMID- 10669556
TI - Immune effects of low-dose radiation: short-term induction of thymocyte apoptosis
and long-term augmentation of T-cell-dependent immune responses.
AB - We and others have shown that low-dose X or gamma irradiation of mice leads to an
increase in their survival after a subsequent lethal high-dose irradiation. The
greatest increase in radioresistance appears at a fixed window of dose and time,
e.g. 8 weeks after 5-10 cGy or 2 weeks after 50 cGy preirradiation. We show that
low-dose irradiation induces thymocyte apoptosis with a maximal level at 6 h
postirradiation that returns to background levels after 24 h. At the same time,
we observed no morphological alteration of splenocytes and no early modification
of the intensity of T-cell-dependent immune responses as measured by plaque
forming cell (PFC) counts. Nevertheless, we found that PFCs were increased 2
weeks after 50 cGy irradiation, which is the same time at which mice expressed
the optimal increase in survival after a second lethal irradiation. We also
examined thymocyte apoptosis and spleen PFCs in mice subjected to other stress
inducing pretreatments. Our results emphasize the existence of a lag time between
the time of low-dose irradiation in vivo and the appearance of radioresistance. A
mechanism that interconnects an environmental stimulus with the response of the
animal is proposed based on the evidence presented here and reported in the
literature.
PMID- 10669557
TI - Early radiation effects on muscarinic receptor-induced secretory responsiveness
of the parotid gland in the freely moving rat.
AB - Although the salivary glands have a low rate of cell turnover, they are
relatively radiosensitive. To study the possible mechanism behind this inherent
radiosensitivity, a rat model was developed in which saliva can be collected
after local irradiation of the parotid gland without the use of anesthetics or
stressful handling. Saliva secretion was induced by the partial muscarinic
receptor agonist pilocarpine (0.03-3 mg/kg) with or without pretreatment with the
beta-adrenoceptor antagonist propranolol (2.5 mg/kg), or the full muscarinic
receptor agonist methacholine (0.16-16 mg/min), and measured during 5 min per
drug dose before and 1, 3, 6 and 10 days after irradiation. The maximal secretory
response induced by pilocarpine plus propranolol was increased compared to that
with pilocarpine alone but did not reach the level of methacholine-induced
secretion, which was about five times higher. One day after irradiation a
decrease in maximal pilocarpine-induced secretion was observed (-22%) using the
same dose of pilocarpine that induces 50% of the maximal response (ED(50)), in
both the absence and presence of propranolol, indicating that the receptor-drug
interaction was not affected by the radiation at this time. The secretory
response to methacholine 1 day after irradiation, however, was normal. At day 3
after irradiation, the maximal methacholine-induced secretion was also affected,
whereas pilocarpine (+/-propranolol)-induced maximal secretion decreased further.
At day 6 after irradiation, maximal secretory responses had declined to
approximately 50% regardless of the agonist used, whereas ED(50) values were
still unaffected. No net acinar cell loss was observed within the first 10 days
after irradiation, and this therefore could not account for the loss in function.
The results indicate that radiation does not affect cell number or receptor-drug
interaction, but rather signal transduction, which eventually leads to the
impaired response. We hypothesize that the early radiation effect, within 3 days,
may be membrane damage affecting the receptor-G-protein signaltransfer. Later
critical damage, however, is probably of a different nature and may be located in
the second-messenger signal transduction pathway downstream from the G protein,
not necessarily involving cellular membranes.
PMID- 10669558
TI - Cellular commitment to radiation-induced apoptosis.
AB - The basic elements of the machinery of programmed cell death (apoptosis) are
built into all mammalian cells and are conserved evolutionarily from nematodes to
humans. The workshop on Commitment to Radiation-Induced Apoptosis at the 11th
International Congress of Radiation Research in Dublin, Ireland reviewed recent
information regarding the basic molecular mechanisms which are fundamental to the
understanding of the process of apoptosis after treatment with ionizing radiation
and some other agents.
PMID- 10669559
TI - Protease inhibitors: current status and future prospects.
PMID- 10669560
TI - A novel, potent, and selective 5-HT(7) antagonist: (R)-3-(2-(2-(4-methylpiperidin
1-yl)ethyl)pyrrolidine-1-sulfonyl) phen ol (SB-269970).
PMID- 10669561
TI - alpha-Substituted N-(sulfonamido)alkyl-beta-aminotetralins: potent and selective
neuropeptide Y Y5 receptor antagonists.
PMID- 10669562
TI - Discovery of a novel dopamine transporter inhibitor, 4-hydroxy-1-methyl-4-(4
methylphenyl)-3-piperidyl 4-methylphenyl ketone, as a potential cocaine
antagonist through 3D-database pharmacophore searching. Molecular modeling,
structure-activity relationships, and behavioral pharmacological studies.
AB - A novel, fairly potent dopamine transporter (DAT) inhibitor, 4-hydroxy-1-methyl-4
(4-methylphenyl)-3-piperidyl 4-methylphenyl ketone (3, K(i) values of 492 and 360
nM in binding affinity and inhibition of dopamine reuptake, respectively), with
significant functional antagonism against cocaine and a different in vitro
pharmacological profile from cocaine at the three transporter sites (dopamine,
serotonin, and norepinephrine) was discovered through 3D-database pharmacophore
searching. Through structure-activity relationships and molecular modeling
studies, we found that hydrophobicity and conformational preference are two
additional important parameters that determine affinity at the DAT site. Chemical
modifications of the lead compound (3) led to a high affinity analogue (6, K(i)
values of 11 and 55 nM in binding affinity and inhibition of dopamine reuptake,
respectively). In behavioral pharmacological testing, 6 mimics partially the
effect of cocaine in increasing locomotor activity in mice but lacks cocaine-like
discriminative stimulus effect in rats. Taken together, these data suggest that 6
represents a promising lead for further evaluations as potential therapy for the
treatment of cocaine abuse.
PMID- 10669563
TI - Structural basis of the thrombin selectivity of a ligand that contains the
constrained arginine mimic (2S)-2-amino-(3S)-3-(1-carbamimidoyl- piperidin-3-yl)
propanoic acid at P1.
AB - We have studied the thrombin and trypsin complexed structures of a pair of
peptidomimetic thrombin inhibitors, containing different P1 fragments. The first
has arginine as its P1 fragment, and the second contains the constrained arginine
mimic (2S)-2-amino-(3S)-3-(1-carbamimidoyl-piperidin-3-yl)-propano ic acid
(SAPA), a fragment known to enhance thrombin/trypsin selectivity of inhibitors.
On the basis of an analysis of the nonbonded interactions present in the
structures of the trypsin and thrombin complexes of the two inhibitors, the
calculated accessible surfaces of the enzymes and inhibitors in the four
complexes, data on known structures of trypsin complexes of inhibitors, and
factor Xa inhibitory potency of these compounds, we conclude that the ability of
this arginine mimic to increase thrombin selectivity of an inhibitor is mediated
by its differential interaction with the residue at position 192
(chymotrypsinogen numbering). Thrombin has a glutamic acid at residue 192, and
trypsin has a glutamine. The analysis also suggests that this constrained
arginine mimic, when present in an inhibitor, might enhance selectivity against
other trypsin-like enzymes that have a glutamine at residue position 192.
PMID- 10669564
TI - Design and synthesis of piperazine-based matrix metalloproteinase inhibitors.
AB - A new generation of cyclic matrix metalloproteinase (MMP) inhibitors derived from
dl-piperazinecarboxylic acid has been described. The design involves:
incorporation of hydroxamic acid as the bidentate chelating agent for catalytic
Zn(2+), placement of a sulfonamide group at the 1N-position of the piperazine
ring to fill the S1' pocket of the enzyme, and finally attachment of diverse
functional groups at the 4N-position to optimize potency and peroral absorption.
A unique combination of all three elements produced inhibitor 20 with high
affinity for MMPs 1, 3, 9, and 13 (24, 18, 1.9, and 1.3 nM, respectively). X-ray
crystallography data obtained for MMP-3 cocrystallized with 20 gave detailed
information on key binding interactions defining an overall scaffold geometry for
piperazine-based MMP inhibitors.
PMID- 10669565
TI - Molecular docking reveals a novel binding site model for fentanyl at the mu
opioid receptor.
AB - The ligand binding modes of a series of fentanyl derivatives are examined using a
combination of conformational analysis and molecular docking to the mu-opioid
receptor. Condensed-phase molecular dynamics simulations are applied to evaluate
potential relationships between ligand conformation and fentanyl substitution and
to generate probable "bioactive" structures for the ligand series. Automated
docking of the largely populated solution conformers identified a common binding
site orientation that places the N-phenethyl group of fentanyl deep in a crevice
between transmembrane (TM) helices II and III while the N-phenylpropanamide group
projected toward a pocket formed by TM-III, -VI, and -VII domains. An analysis of
the binding modes indicates the most potent fentanyl derivatives adopt an
extended conformation both in solution and in the bound state, suggesting binding
affinity may depend on the conformational preferences of the ligands. The results
are consistent with ligand binding data derived from chimeric and mutant receptor
studies as well as structure-activity relationship data reported on a wide range
of fentanyl analogues. The binding site model is also compared to that of N
phenethylnormorphine. An overlay of the bound conformation of the opiate and cis
3-methylfentanyl shows the N-phenethyl groups occupy equivalent binding domains
in the receptor. While the cationic amines of both ligand classes were found
docked to an established anchor site (D149 in TM-III), no overlap was observed
between the N-phenylpropanamide group and the remaining components of the opiate
scaffold. The unique binding mode(s) proposed for the fentanyl series may, in
part, explain the difficulties encountered in defining models of recognition at
the mu-receptor and suggest opioid receptors may display multiple binding
epitopes. Furthermore, the results provide new insight to the design of
experiments aimed at understanding the structural basis to the differential
selectivities of ligands at the mu-, delta-, and kappa-opioid receptors.
PMID- 10669566
TI - Derivation of pharmacophore and CoMFA models for leukotriene D(4) receptor
antagonists of the quinolinyl(bridged)aryl series.
AB - The present work focuses on the study of the three-dimensional (3D) structural
requirements for the leukotriene D(4) (LTD(4)) antagonistic activity of compounds
having the basic quinolinyl(bridged)aryl framework. An approach combining
pharmacophore mapping, molecule alignment, and CoMFA models was used to derive a
hypothesis for a series of LTD(4) antagonists having the basic diaryl-bridged
framework. In this compound series, the produced pharmacophore hypotheses have
shown to yield molecule alignments suitable to derive valuable CoMFA models.
Model selection focused on (1) obtention of coherent modeling results, (2)
consistency with the available SAR data, and (3) ability to predict the activity
of an independent set of congeneric molecules. This approach resulted in a
combined pharmacophore and CoMFA model that can generally represent the
antagonistic activity within a log unit of the measured value for compounds of
the series. The resulting pharmacophore (model C) consists of an acidic or
negative ionizable function (AC), a hydrogen-bond acceptor (HBA), and three
hydrophobic regions (HY) and produces chemically meaningful alignments with the
most active compounds of the series mapping the pharmacophore in a extended
energetically favorable conformation.
PMID- 10669567
TI - Successful virtual screening of a chemical database for farnesyltransferase
inhibitor leads.
AB - Virtual screening of chemical databases is an emerging approach in drug discovery
that uses computers to dock chemicals into the active site of a drug target to
identify leads through evaluation of binding affinities of the chemicals.
However, there are concerns about the validity and scope of the reported virtual
screens due to lack of studies to show that randomly selected chemicals are not
equally active and due to the fact that metalloproteins were rarely used as drug
targets. We have performed a virtual screening of a chemical database to identify
prototypic inhibitors of farnesyltransferase (FT) with zinc present in the active
site. Among the 21 compounds identified by computers, four inhibited FT in vitro
with IC(50) values in the range from 25 to 100 microM. The most potent inhibitor
also inhibited FT in human lung cancer cells. In contrast, none of 21 randomly
selected compounds have an IC(50) lower than 100 microM. The results demonstrate
the validity of virtual screening and the feasibility of applications of this
approach to metalloprotein drug targets, such as matrix metalloproteinases,
farnesyltransferase, and HIV-1 integrase, for the treatments of cardiovascular
diseases, cancers, and AIDS.
PMID- 10669568
TI - Syntheses and structure-activity relationships of 5,6,7, 8-tetrahydro-5,5,8,8
tetramethyl-2-quinoxaline derivatives with retinoic acid receptor alpha agonistic
activity.
AB - In the course of our studies on retinoic acid receptor (RAR) agonists, we have
designed and synthesized a series of quinoxaline derivatives. One of them, 4-[5
(5,6,7,8-tetrahydro-5,5,8, 8-tetramethyl-2-quinoxalinyl)-1H-2-pyrrolyl]benzoic
acid (3a), which possesses a 2,5-disubstituted pyrrole moiety, showed selectivity
for the RARalpha receptor and exerted highly potent cell-differentiating activity
on HL-60 cells.
PMID- 10669569
TI - Synthesis, molecular modeling, and pharmacological testing of bis-quinolinium
cyclophanes: potent, non-peptidic blockers of the apamin-sensitive Ca(2+)
activated K(+) channel.
AB - The synthesis and pharmacological testing of two series of novel bis-quinolinium
cyclophanes as blockers of the apamin-sensitive Ca(2+)-activated K(+) (SK(Ca))
channel are presented. In these cyclophanes the two 4-aminoquinolinium groups are
joined at the ring N atoms (linker L) and at the exocyclic N atoms (linker A). In
those cases where A and L contain two or more aromatic rings each, the activity
of the compound is not critically dependent upon the nature of the linkers. When
A and L each have only one benzene ring, the blocking potency changes
dramatically with simple structural variations in the linkers. One of these
smaller cyclophanes having A = benzene-1,4-diylbis(methylene) and L = benzene-1,
3-diylbis(methylene) (3j, 6,10-diaza-1,5(1,4)-diquinolina-3(1,3),8(1, 4)
dibenzenacyclodecaphanedium tritrifluoroacetate, UCL 1684) has an IC(50) of 3 nM
and is the most potent non-peptidic SK(Ca) channel blocker described to date.
Conformational analysis on the smaller cyclophanes using molecular modeling
techniques suggests that the differences in the blocking potencies of the
compounds may be attributable to their different conformational preferences.
PMID- 10669570
TI - Synthesis and in vitro and in vivo functional studies of ortho-substituted
phenylpiperazine and N-substituted 4-N-(o-methoxyphenyl)aminopiperidine analogues
of WAY100635.
AB - WAY100635 (2), N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2
pyridinyl)cyclohe xanecarboxamide, is a silent serotonin 5-HT(1A) antagonist,
which is now widely used to study the 5-HT(1A) receptor both in vivo and in
vitro. In this paper, we describe the synthesis and in vitro (5-HT(1A) affinity
and pA(2) values at guinea pig ileum strips) and in vivo (hypothermia and
ultrasonic vocalization) pharmacology at the serotonin 5-HT(1A) receptor of
several closely related analogues of 2. Test compounds 12 and 14, in which the
arylpiperazine moiety of 2 has been replaced by an arylaminopiperidine moiety,
showed no affinity or antagonistic activity at the 5-HT(1A) receptor.
Substitution of the o-methoxy group of 2 by larger fluoroalkoxy or sulfonyloxy
substituents did not alter the in vitro or in vivo pharmacology to any great
extent; in vivo both the fluoropropyl analogue 5 and the triflate analogue 7 are
equipotent to WAY100635 itself. The O-desmethyl analogue 3 proved to be the most
potent antagonist at the serotonin 5-HT(1A) postsynaptic receptor sites in this
series.
PMID- 10669571
TI - Water-soluble phosphate prodrugs of 1-propargyl-8-styrylxanthine derivatives,
A(2A)-selective adenosine receptor antagonists.
AB - Water-soluble prodrugs of potent, A(2A)-selective adenosine receptor (AR)
antagonists were prepared. 8-(m-Bromostyryl)-3, 7-dimethyl-1-propargylxanthine
(BS-DMPX, 11) and the analogous 8-(m-methoxystyryl)xanthine derivative (MS-DMPX,
5b) were used as starting points. It was found that polar functional groups
suitable for the attachment of a prodrug moiety were tolerated on the styryl ring
and even better on the 3-substituent. 8-(m-Hydroxystyryl)-DMPX (7) and 3-(3
hydroxypropyl)-8-(m-methoxystyryl)-1-propargylxanthine (5e, MSX-2) were the most
potent and A(2A)-selective compounds and were selected for prodrug formation. For
the preparation of 5e a new ring-closure method was applied. Treatment of 6-amino
1-(3-hydroxypropyl)-5-(m-methoxycinnamoylamino)-3-propa rgylur acil with
hexamethyldisilazane at high temperature resulted in higher yields of the target
xanthine than the standard ring-closure procedure using sodium hydroxide.
Phosphate prodrugs were prepared by classical phosphorylation using phosphorus
oxychloride and alternatively by using a phosphoramidite method. Phosphates of
the aliphatic alcohol 5e could be obtained by both methods in similar yields. The
phenolic compound 7, however, could be phosphorylated only by using the
phosphoramidite method. The disodium salts of the phosphate prodrugs exhibited
high water solubility (8-(m-methoxystyryl)-7-methyl-3-[3-O-phosphatylpropyl]-1-
propargylxan thine disodium salt, 9b: 17 mM, 9 mg/mL). Prodrug 9b was found to be
stable in aqueous solution (pH 7) but readily cleaved by phosphatases to liberate
5e (MSX-2). Compound 5e showed high affinity for rat A(2A) AR (K(i) = 8 nM),
human recombinant A(2A) AR (K(i) = 5 nM), and human native A(2A) AR (K(i) = 15
nM) and was highly selective versus rat A(1) AR (110-fold), human recombinant
A(2A) AR (500-fold), human A(2B) AR (>2000-fold), and human A(3) AR (>2000-fold).
PMID- 10669572
TI - 4-(1,3-Dimethoxyprop-2-ylamino)-2,7-dimethyl-8-(2, 4-dichlorophenyl)pyrazolo[1,5
a]-1,3,5-triazine: a potent, orally bioavailable CRF(1) receptor antagonist.
AB - Structure-activity studies in the pyrazolo[1,5-a]-1,3,5-triazine series led to
the discovery that compound 11i (DMP696) is a potent hCRF(1) receptor antagonist
(K(i) = 1.7 nM vs 7.5 nM for alpha-hel-CRF(9-41), hCRF(1) adenylate cyclase
IC(50) = 82 nM vs 286 nM for alpha-hel-CRF(9-41)). Compound 11i has excellent
oral pharmacokinetic profiles in rats and dogs (37% and 50% oral
bioavailabilities, respectively). This compound displays good activity in the rat
situational anxiety model (MED = 3 mg/kg (po)), whereas a literature standard 1
(CP154526-1) was inactive (MED > 30 mg/kg (po)). Analogue 11i reduced
stereotypical mouth movements in rhesus monkeys by 50% at 21 mg/kg (po) using the
human intruder paradigm. Overall, the profile of pyrazolotriazine 11i indicates
that hCRF(1) receptor antagonists may be anxiolytic agents, which have reduced
motor side effect profiles.
PMID- 10669573
TI - Design of cancer-specific antitumor agents based on
aziridinylcyclopent[b]indoloquinones.
AB - The merits of N-unsubstituted indoles and cyclopent[b]indoles as DNA-directed
reductive alkylating agents are described. These systems represent a departure
from N-substituted and pyrrolo[1, 2-a]-fused systems such as the mitomycins and
mitosenes. The cyclopent[b]indole-based aziridinylquinone system, when bearing an
acetate leaving group with or without an N-acetyl group, was cytotoxic and
displayed significant in vivo activity against syngeneic tumor implants. These
analogues were superior to the others studied in terms of both high specificity
for the activating enzyme DT-diaphorase and high percent DNA alkylation.
Alkylation by a quinone methide intermediate as well as by the aziridinyl group
could lead to cross-linking. The possible metabolites of the most active indole
species were prepared and found to retain cytotoxicity, suggesting that in vivo
activity could be sustained. The indole systems in the present study display
selectivity for melanoma and, depending on the substituents present, selectivity
for non-small-cell lung, colon, renal, and prostate cancers. The cancer
specificities observed are believed to pertain to differential substrate
specificities for DT-diaphorase.
PMID- 10669574
TI - Acid-catalyzed degradation of clarithromycin and erythromycin B: a comparative
study using NMR spectroscopy.
AB - One of the major drawbacks in the use of the antibiotic erythromycin A is its
extreme acid sensitivity, leading to degradation in the stomach following oral
administration. The modern derivative clarithromycin degrades by a different
mechanism and much more slowly. We have studied the pathway and kinetics of the
acid-catalyzed degradation of clarithromycin and of erythromycin B, a
biosynthetic precursor of erythromycin A which also has good antibacterial
activity, using (1)H NMR spectroscopy. Both drugs degrade by loss of the
cladinose sugar ring and with similar rates of reaction. These results suggest
that erythromycin B has potential as an independent therapeutic entity, with
superior acid stability compared with erythromycin A and with the advantage over
clarithromycin of being a natural product.
PMID- 10669575
TI - Drug delivery systems based on trimethyl lock lactonization: poly(ethylene
glycol) prodrugs of amino-containing compounds.
AB - A novel methodology for the synthesis of poly(ethylene glycol) (PEG) prodrugs of
amino-containing compounds has been developed which is based on the trimethyl
lock lactonization reaction. These PEG-modified double prodrugs are water
soluble, and by selective modification of the specifier or trigger, plasma half
lives can be adjusted at will to result in a wide range of values. Facile
syntheses of ester, carbonate, and carbamate functionalities were accomplished
and combined with greater or lesser degrees of steric hindrance in the spacer
group, or on the aromatic framework, to achieve predictable ranges of drug
concentration in plasma. In vivo screening of PEG prodrugs was done using a M109
syngeneic solid mouse tumor model. One of the PEG-daunorubicin prodrugs, with a
half-life of 2 h, was evaluated in an in vivo solid tumor panel and found to be
more efficacious against ovarian tumors (SKOV3) than equivalent amounts of
daunorubicin.
PMID- 10669576
TI - Potent and selective non-peptidic inhibitors of endothelin-converting enzyme-1
with sustained duration of action.
AB - Potent and selective non-peptidic inhibitors of human endothelin-converting
enzyme-1 (ECE-1) have been designed as potential modulators of endothelin (ET-1)
production in vivo. Because of its unique structural characteristics and long
duration of action in vivo, the dual ECE-1 and neutral endopeptidase 24.11 (NEP)
inhibitor, CGS 26303, was selected as an attractive lead for further optimization
of potency and selectivity. Replacement of the P(1)' biphenyl substituent of CGS
26303 by a conformationally restricted 3-dibenzofuranyl group led to more potent
and more selective ECE-1 inhibitors, such as the tetrazole 27. The remarkable
effect of this P(1)' modification allowed for the first time
phosphonomethylcarboxylic acids, such as 29, to display both potent (IC(50) = 22
nM) and selective (104-fold vs NEP) ECE-1 inhibition. Chemoenzymatic syntheses of
the new alpha-amino acid (S)-3-dibenzofuran-3-ylalanine intermediate were
developed, and improved procedures to generate substituted alpha
aminoalkylphosphonic acids were devised to support the production of various
analogues. Although additional gains in intrinsic ECE-1 inhibitory potency could
occasionally be achieved by addition of a P(1) side chain, these compounds (e.g.
43a) showed poor functional activity in vivo in the big ET-1 pressor test.
Phosphonoalkyl dipeptides featuring 3-dibenzofuranyl groups in both the P(1)' and
P(2)' positions were also very potent ECE-1 inhibitors, albeit lacking the
desired selectivity against NEP. Functionally, 27and 29 were the two most
efficacious compounds from this study, producing sustained inhibition of ECE-1
activity in rats, as measured by their ability to block the hypertensive effects
induced by big ET-1. This profile was similar to that of a potent ET(A)/ET(B)
dual receptor antagonist, SB 209670. Due to their favorable in vitro and in vivo
profiles, 27 (CGS 34043) and 29 (CGS 35066) constitute new pharmacological tools
useful in assessing the role of ECE-1 in pathological conditions.
PMID- 10669577
TI - Antimalarial activity of compounds interfering with Plasmodium falciparum
phospholipid metabolism: comparison between mono- and bisquaternary ammonium
salts.
AB - On the basis of a previous structure-activity relationship study, we identified
some essential parameters, e.g. electronegativity and lipophilicity, required for
polar head analogues to inhibit Plasmodium falciparum phospholipid metabolism,
leading to parasite death. To improve the in vitro antimalarial activity, 36
cationic choline analogues consisting of mono-, bis-, and triquaternary ammonium
salts with distinct substituents of increasing lipophilicity were synthesized.
For monoquaternary ammonium salts, an increase in the lipophilicity around
nitrogen was beneficial for antimalarial activity: IC(50) decreased by 1 order of
magnitude from trimethyl to tripropyl substituents. Irrespective of the polar
head substitution (methyl, ethyl, hydroxyethyl, pyrrolidinium), increasing the
alkyl chain length from 6 to 12 methylene groups always led to increased
activity. The highest activity was obtained for the N,N,N-tripropyl-N-dodecyl
substitution of nitrogen (IC(50) 33 nM). Beyond 12 methylene groups, the
antimalarial activities of the compounds decreased slightly. The structural
requirements for bisquaternary ammonium salts in antimalarial activity were very
similar to those of monoquaternary ammonium salts, i.e. polar head steric
hindrance and lipophilicity around nitrogen (methyl, hydroxyethyl, ethyl,
pyrrolidinium, etc.). In contrast, with bisquaternary ammonium salts, increasing
the lipophilicity of the alkyl chain between the two nitrogen atoms (from 5 to 21
methylene groups) constantly and dramatically increased the activity. Most of
these duplicated molecules had activity around 1 nM, and the most lipophilic
compound synthesized exhibited an IC(50) as low as 3 pM (21 methylene groups).
Globally, this oriented synthesis produced 28 compounds out of 36 with an IC(50)
lower than 1 microM, and 9 of them had an IC(50) in the nanomolar range, with 1
compound in the picomolar range. This indicates that developing a pharmacological
model for antimalarial compounds through choline analogues is a promising
strategy.
PMID- 10669578
TI - New selective and potent 5-HT(1B/1D) antagonists: chemistry and pharmacological
evaluation of N-piperazinylphenyl biphenylcarboxamides and biphenylsulfonamides.
AB - A series of new analogues of N-[4-methoxy-3-(4-methylpiperazin-1-yl)phenyl] 2'
methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)biphenyl-4-carboxamide (1; GR127935) as
potent and selective 5-HT(1B/1D) antagonists were synthesized and evaluated
pharmacologically. Their receptor binding profiles were comparable to that of 1.
The 1,3,4-oxadiazole isomer 2 and the 4'-aminocarbonyl and 4'-amidinyl analogues
(9 and 10) of 1 had higher affinities at the rat 5-HT(1B) receptor (IC(50) =
0.93, 1. 3, and 0.5 nM, respectively) and calf 5-HT(1D) receptor (IC(50) = 37,
10, and 3 nM, respectively) than did 1 (1.6 and 52 nM for rat 5-HT(1B) and calf 5
HT(1D) receptors, respectively). In the functional in vitro testing of 5
HT(1B/1D) antagonistic properties, 2, 9, 10, 11b (O-demethylated derivative of
2), 13a (O-methylsulfonyl analogue of 2), and 16 (which differs from 2 with a
sulfonamide linker) showed more pronounced effects in the K(+)-induced 5-HT
release in the cortex of guinea pig than did 1 and 3 (SB224289). Compounds 2, 9,
and 10 were equally potent as 1 in rabbit saphenous vein model (pA(2) > 9). A
biochemical study of 2 with in vivo microdialysis in the rat brain showed that it
is capable of augmenting citalopram (a selective serotonin reuptake inhibitor,
SSRI) induced 5-HT release in rat ventral hippocampus, while preventing the
decrease in acetylcholine release elicited by citalopram administration. The
molecular structure of 2 was determined by single-crystal X-ray analysis. The log
P and log D values of these compounds were calculated. This study contributes to
the SAR study of N-piperazinylphenyl biphenylcarboxamides as selective and potent
5-HT(1B/1D) antagonists.
PMID- 10669579
TI - Integrin-like proteins in Candida spp. and other microorganisms.
AB - The vertebrate integrins provide a paradigm for cell surface proteins involved in
adhesion and morphogenesis. However, homologs of integrins have been found in
more primitive organisms. This review will discuss the evidence for surface
proteins in Candida albicans and Candida tropicalis that contain motifs
reminiscent of integrins and will analyze the contributions of one of these
proteins, Int1p, to adhesion, morphogenesis, and virulence. Other microorganisms
thought to express integrin-like proteins will also be addressed.
PMID- 10669580
TI - To perforate a leaf of grass.
PMID- 10669581
TI - High levels of gene flow and heterozygote excess characterize Rhizoctonia solani
AG-1 IA (Thanatephorus cucumeris) from Texas.
AB - To date, much of the genetics of the basidiomycete Thanatephorus cucumeris
(anamorph = Rhizoctonia solani) remains unknown. Here, we present a population
genetics study using codominant markers to augment laboratory analyses. Seven
single-copy nuclear RFLP markers were used to examine 182 isolates of Rhizoctonia
solani AG-1 IA collected from six commercial rice fields in Texas. Thirty-six
multilocus RFLP genotypes were identified. Population subdivision analyses
indicated a high degree of gene flow/migration between the six geographic
populations. Tests for Hardy-Weinberg equilibrium (HWE) among the 36 multilocus
RFLP genotypes revealed that four of the seven loci did not significantly differ
from HWE. Subsequent analysis demonstrated that departures from HWE at the three
remaining loci were due to an excess of heterozygotes. Data presented here
suggest that R. solani AG-1 IA is actively outbreeding (heterothallic). Possible
explanations for heterozygote excess, which was observed at all seven RFLP loci,
are discussed.
PMID- 10669582
TI - Construction of a bacterial artificial chromosome library of Phytophthora
infestans and transformation of clones into P. infestans.
AB - A bacterial artificial chromosome (BAC) library of Phytophthora infestans was
constructed in a derivative of pBELOBACII that had been modified by adding a npt
selectable marker gene for transforming P. infestans. A total library of 8 genome
equivalents was generated and 16,128 clones with inserts averaging 75 kb (4.9
genome equivalents) were individually picked and stored as an arrayed library in
microtiter plates. This coverage was confirmed by screening the library for 11
DNA loci by colony hybridization and by polymerase chain reaction of DNA pools.
Transformation of P. infestans with BAC clones containing inserts of 93 to 135 kb
was demonstrated. The efficiency of transformation with most BACs was noticeably
higher than that with smaller plasmids. Detailed analyses of transformants
obtained with a 102-kb BAC indicated that entire inserts were present in about
one-quarter of the transformants.
PMID- 10669583
TI - Evidence that MRas1 and MRas3 proteins are associated with distinct cellular
functions during growth and morphogenesis in the fungus Mucor racemosus.
AB - The filamentous fungus Mucor racemosus provides a simple and unique model system
for defining the function of individual ras genes in a gene family which is
closely related to mammalian ras genes. The current study was designed to
investigate the role of Mras1 and Mras3 in different stages of fungal
morphogenesis, including sporangiospore germination, sporulation, and dimorphic
transitions. The overall patterns of Mras1 and Mras3 transcript and protein
accumulation were markedly different but, in general, transcripts and proteins
were present at low levels during spherical growth and their accumulated level
increased severalfold during polar growth (germ tube emergence and elongation).
In contrast to Mras1, relatively high levels of Mras3 transcript accumulated
during sporulation and MRas3 protein accumulated in sporangiospores.
Transformation of M. racemosus with an activated allele of Mras3 reduced growth
rate during aerobic sporangiospore germination, while a dominant-negative allele
of Mras3 caused a 40% decrease in viable asexual spores. An activated allele of
Mras1 increased growth rate during sporangiospore germination but neither
activated nor dominant-negative alleles of Mras1 affected total number of asexual
spores. Expression of MRas3 and MRas1 proteins appear to be subject to different
regulatory mechanisms: exogenous dibutyryl-cAMP and fusidienol caused a strong
repression of the level of MRas3 protein (but not MRas1) concurrent with the
inhibition of polar growth. Differential posttranslational modification and
intracellular localization of MRas1 and MRas3 proteins were also observed. The
data strongly suggest that Mras3 and Mras1 play different roles in regulation of
cell growth and morphogenesis in Mucor.
PMID- 10669584
TI - Invasive hyphal growth in Wangiella dermatitidis is induced by stab inoculation
and shows dependence upon melanin biosynthesis.
AB - Stab inoculation of agar medium with yeasts of the human pathogen Wangiella
dermatitidis resulted in induction of invasive hyphae. Mechanical penetration of
agar was indicated by the observation that an increase in medium gel strength
slowed the rate of substrate invasion. A melanized wild-type strain (8656)
exhibited much faster invasive growth through 2-8% agar than three melanin
deficient mutants. Inhibition of melanin synthesis in strain 8656 using
tricyclazole resulted in a decrease in its rate of invasive growth, while
scytalone restored melanin synthesis in the albino mel3 strain and boosted its
rate of invasive growth. Earlier research established that cellular melanization
is also associated with invasive hyphal growth in the mouse brain, and infections
with strain 8656 are invariably lethal. Together, these in vitro and in vivo data
indicate that biomechanical characteristics of fungi may be important
determinants of virulence and disease progression in human and animal mycoses.
PMID- 10669585
TI - Blue light signaling chains in Phycomyces: phototransduction of carotenogenesis
and morphogenesis involves distinct protein kinase/phosphatase elements.
AB - Carotenogenesis and morphogenesis represent two of the several responses
sensitive to blue light which characterize the lower eukaryote Phycomyces
blakesleeanus. Speculating that reversible phosphorylation may be an
intracellular event beyond the photoperception step, we resorted to the use of
first-choice inhibitors of protein phosphatases and protein kinases. The mycelial
beta-carotene content of dark-grown cultures was induced by all agents
administered, while the morphogenic output showed the typical trend effected by
light only with one of the protein kinase inhibitors. Our data provide convincing
evidence that protein phosphorylation plays a regulatory role in
photocarotenogenesis and photomorphogenesis of Phycomyces. According to the model
we propose, the putative signaling elements involved are anticipated to have a
repressive function in the dark so that the responses are maintained in the "off"
mode until the moment photon information has to flow through the regulatory
circuit.
PMID- 10669586
TI - Major surface glycoprotein genes from Pneumocystis carinii f. sp. ratti.
AB - Pneumocystis carinii occurs in a variety of mammals, each of which harbors one or
more genetically distinct "special forms" of the microbe. Laboratory rats can be
infected by two special forms, P. carinii f. sp. ratti and P. carinii f. sp.
carinii. P. carinii f. sp. carinii has a variable antigen, the major surface
glycoprotein (MSG), the expression of which is controlled by genetic
recombination. Recombination may involve the CRJE, a 23-bp DNA sequence element
invariant among P. carinii f. sp. carinii MSG genes. To better understand the
role of the CRJE in MSG gene expression and to explore the possible role of MSG
in P. carinii infection in rats, P. carinii f. sp. ratti MSG genes were studied.
These genes were found to be related to MSG genes of P. carinii f. sp. carinii,
but less so than MSG genes from P. carinii f. sp. carinii are to each other. P.
carinii f. sp. ratti MSG genes were present throughout the genome and were
expressed as an abundant mRNA species slightly smaller than that found in P.
carinii f. sp. carinii. P. carinii f. sp. ratti MSG transcripts included a CRJE
like sequence only 78% identical to the CRJE of P. carinii f. sp. carinii.
Comparison of MSG proteins from the two rat special forms of P. carinii to those
from human, ferret, and mouse P. carinii did not support the hypothesis that
growth in the rat lung requires certain primary MSG peptide sequences.
PMID- 10669587
TI - The frost gene of Neurospora crassa is a homolog of yeast cdc1 and affects hyphal
branching via manganese homeostasis.
AB - The Neurospora crassa mutant frost has a hyperbranching phenotype that can be
corrected by adding Ca(2+), suggesting that characterization of this gene might
clarify the mechanism of Ca(2+)-dependent tip growth. The wild-type allele was
cloned by sib selection using protoplasts from arthroconidia. RFLP analysis
revealed that the cloned DNA fragment mapped to the fr locus. The nucleotide
sequence of genomic and cDNA was determined. The deduced amino acid sequence
showed homology to the Saccharomyces cerevisiae CDC1 protein, implicated in
manganese homeostasis. The fr mutant was sensitive to Mn(2+), and a revertant
allele whose product differs by one amino acid was tolerant to Mn(2+). Mn(2+)
depletion induced the wild-type strain to hyperbranch, resulting in a morphology
similar to that of fr. The fr mutant was also sensitive to calcineurin
inhibitors. These results suggest that fr is involved in Mn(2+) homeostasis and
point to a role for Mn(2+) in Neurospora branching.
PMID- 10669589
TI - Cumulative organism index volumes 26-28
PMID- 10669588
TI - Phylogenetic analysis of a dataset of fungal 5.8S rDNA sequences shows that
highly divergent copies of internal transcribed spacers reported from
Scutellospora castanea are of ascomycete origin.
AB - Using a dataset comprising 5.8S rDNA sequences from a wide range of fungi, we
show that some sequences reported recently from the arbuscular mycorrhizal (AM)
fungus Scutellospora castanea most likely originate from Ascomycetes. Other ITS
and 5.8S sequences which were previously reported are confirmed as being clearly
of mycorrhizal origin and are variable within one isolate of S. castanea.
However, these results mean that previous conclusions which were drawn regarding
the heterokaryotic status of AM fungal spores remain unproven. We provide an
enlarged 5.8S rDNA dataset that can be used to check ITS sequences for conflicts
with well-established phylogenies of the organisms that they were obtained from.
PMID- 10669590
TI - The serine protease inhibitor canonical loop conformation: examples found in
extracellular hydrolases, toxins, cytokines and viral proteins.
AB - Methods for the prediction of protein function from structure are of growing
importance in the age of structural genomics. Here, we focus on the problem of
identifying sites of potential serine protease inhibitor interactions on the
surface of proteins of known structure. Given that there is no sequence
conservation within canonical loops from different inhibitor families, we first
compare representative loops to all fragments of equal length among proteins of
known structure by calculating main-chain RMS deviation. Fragments with RMS
deviation below a certain threshold (hits) are removed if residues have solvent
accessibilities appreciably lower than those observed in the search structure.
These remaining hits are further filtered to remove those occurring largely
within secondary structure elements. Likely functional significance is restricted
further by considering only extracellular protein domains. By comparing different
canonical loop structures to the protein structure database, we show that the
method is able to detect previously known inhibitors. In addition, we discuss
potentially new canonical loop structures found in secreted hydrolases, toxins,
viral proteins, cytokines and other proteins. We discuss the possible functional
significance of several of the examples found, and comment on implications for
the prediction of function from protein 3D structure.
PMID- 10669591
TI - Stabilization of poliovirus by capsid-binding antiviral drugs is due to entropic
effects.
AB - When poliovirus attaches to its receptor or is heated in hypotonic buffers, the
virion undergoes an irreversible conformational transition from the native 160 S
(or N) particle to the 135 S (or A) particle, which is believed to mediate cell
entry. The first-order rate constants for the thermally induced transition have
been measured as a function of temperature for virus alone and for complexes of
the virus with capsid-binding drugs that inhibit the receptor and thermally
mediated conversion. Although the drugs have minimum inhibitory concentrations
(MIC) that differ by almost three orders of magnitude, the activation energies
for the N to A transition for the drug complexes (145 kcal/mol) were
indistinguishable from each other or from that of the virus alone. We conclude
that the antiviral activity of these drugs derives from a novel mechanism in
which drug-binding stabilizes the virions through entropic effects.
PMID- 10669592
TI - Structure of human neutral endopeptidase (Neprilysin) complexed with
phosphoramidon.
AB - Neutral endopeptidase is a mammalian type II integral membrane zinc-containing
endopeptidase, which degrades and inactivates a number of bioactive peptides. The
range of substrates cleaved by neutral endopeptidase in vitro includes the
enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor.
Due to the physiological importance of neutral endopeptidase in the modulation of
nociceptive and pressor responses there is considerable interest in inhibitors of
this enzyme as novel analgesics and anti-hypertensive agents. Here we describe
the crystal structure of the extracellular domain (residues 52-749) of human NEP
complexed with the generic metalloproteinase inhibitor phosphoramidon at 2.1 A
resolution. The structure reveals two multiply connected folding domains which
embrace a large central cavity containing the active site. The inhibitor is bound
to one side of this cavity and its binding mode provides a detailed understanding
of the ligand-binding and specificity determinants.
PMID- 10669593
TI - Solution structure and dynamics of the DNA-binding domain of the adipocyte
transcription factor FREAC-11.
AB - Transcription factors of the forkhead type share a highly conserved DNA-binding
domain of about 100 amino acid residues. FREAC-11, expressed in adipocytes,
belongs to this class. Here, we report on NMR studies that established the three
dimensional structure of the FREAC-11, DNA-binding domain. Although apparent
similarities to the structures of other members within the forkhead family are
observed, the structure also reveals some remarkable differences. Along with the
complementary dynamics, the data provide insight into the fundamentals of
sequence specificity within a highly conserved motif.
PMID- 10669594
TI - Salmonella enteritidis fimbriae displaying a heterologous epitope reveal a
uniquely flexible structure and assembly mechanism.
AB - Two distinct Salmonella fimbrins, AgfA and SefA, comprising thin aggregative
fimbriae SEF17 and SEF14, respectively, were each genetically engineered to carry
PT3, an alpha-helical 16-amino acid Leishmania T-cell epitope derived from the
metalloprotease gp63. To identify regions within AgfA and SefA fimbrins amenable
to replacement with this epitope, PCR-generated chimeric fimbrin genes were
constructed and used to replace the native chromosomal agfA and sefA genes in
Salmonella enteritidis. Immunoblot analysis using anti-SEF17 and anti-PT3 sera
demonstrated that all ten AgfA chimeric fimbrin proteins were expressed by S.
enteritidis under normal growth conditions. Immunoelectron microscopy confirmed
that eight of the AgfA::PT3 proteins were effectively assembled into cell surface
exposed fimbriae. The PT3 replacements in AgfA altered Congo red (CR) binding,
cell-cell adhesion and cell surface properties of S. enteritidis to varying
degrees. However, these chimeric fimbriae were still highly stable, being
resistant to proteinase K digestion and requiring harsh formic acid treatment for
depolymerization. In marked contrast to AgfA, none of the chimeric SefA proteins
were expressed or assembled into fimbriae. Since each PT3 replacement constituted
over 10% of the AgfA amino acid sequence and all ten replacements collectively
represented greater than 75% of the entire AgfA primary sequence, the ability of
AgfA to accept large sequence substitutions and still assemble into fibers is
unique among fimbriae and other structural proteins. This structural flexibility
may be related to the novel fivefold repeating sequence of AgfA and its recently
proposed structure Proper formation of chimeric fimbrial fibers suggests an
unusual assembly mechanism for thin aggregative fimbriae which tolerates aberrant
structures. This study opens a range of possibilities for Salmonella thin
aggregative fimbriae as a carrier of heterologous epitopes and as an experimental
model for studies of protein structure.
PMID- 10669595
TI - Psoralen adducts induced by triplex-forming oligonucleotides are refractory to
repair in HeLa cells.
AB - The use of triple helix-forming oligonucleotides constitutes an attractive
strategy to regulate gene expression by inhibition of transcription. Psoralen
oligonucleotide conjugates form, upon irradiation, covalent triplexes and thereby
modify the specific target sequence. The processing of such photoproducts on the
promoter of the gene coding for the interleukin-2 receptor alpha chain was
investigated in HeLa cells and HeLa nuclear extracts. We demonstrate that
psoralen cross-links are not repaired within the cell extracts nor inside cells.
The mechanism of repair inhibition was elucidated in vitro: the presence of the
third strand oligonucleotide inhibits the incision step of the damaged target by
repair endonucleases. These results demonstrate the possibility of using this
approach to induce a persistent intracellular DNA damage at a specific site and
to afford prolonged transcription inhibition.
PMID- 10669596
TI - Bacteriophage P22 Abc2 protein binds to RecC increases the 5' strand nicking
activity of RecBCD and together with lambda bet, promotes Chi-independent
recombination.
AB - Bacteriophage P22 Abc2 protein binds to the RecBCD enzyme from Escherichia coli
to promote phage growth and recombination. Overproduction of the RecC subunit in
vivo, but not RecB or RecD, interfered with Abc2-induced UV sensitization,
revealing that RecC is the target for Abc2 in vivo. UV-induced ATP crosslinking
experiments revealed that Abc2 protein does not interfere with the binding of ATP
to either the RecB or RecD subunits in the absence of DNA, though it partially
inhibits RecBCD ATPase activity. Productive growth of phage P22 in wild-type
Salmonella typhimurium correlates with the presence of Abc2, but is independent
of the absolute level of ATP-dependent nuclease activity, suggesting a
qualitative change in the nature of Abc2-modified RecBCD nuclease activity
relative to the native enzyme. In lambda phage crosses, Abc2-modified RecBCD
could substitute for lambda exonuclease in Red-promoted recombination; lambda Gam
could not. In exonuclease assays designed to examine the polarity of digestion,
Abc2 protein qualitatively changes the nature of RecBCD double-stranded DNA
exonuclease by increasing the rate of digestion of the 5' strand. In this
respect, Abc2-modified RecBCD resembles a RecBCD molecule that has encountered
the recombination hotspot Chi. However, unlike Chi-modified RecBCD, Abc2-modified
RecBCD still possesses 3' exonuclease activity. These results are discussed in
terms of a model in which Abc2 converts the RecBCD exonuclease for use in the P22
phage recombination pathway. This mechanism of P22-mediated recombination
distinguishes it from phage lambda recombination, in which the phage
recombination system (Red) and its anti-RecBCD function (Gam) work independently.
PMID- 10669597
TI - Resolution of tethered antiparallel and parallel holliday junctions by the Flp
site-specific recombinase.
AB - Members of the integrase family site-specific recombinases (also called the
tyrosine family) bring about recombination in two steps by exchanging pairs of
single strands at a time. The product of the first exchange reaction is a four
way DNA junction, the Holliday intermediate. The conformational dynamics by which
the recombination complex "isomerizes" from the Holliday-forming to the Holliday
resolving mode are not well understood. Experiments with the lambda Int and
Escherichia coli XerC/XerD systems imply that the strand configurations at the
branch point of the protein-free junction dictate the resolution mode in the
protein-bound junction. We have examined the question of strand bias during
resolution for the Flp system by using a series of synthetic Holliday junctions
that are conformationally constrained by local sequences or by strand tethering.
We have not observed a strong resolution bias in favor of the strands designed to
assume the "crossed" configuration within the unbound junction. The resolution
patterns with antiparallel junctions in a variety of substrate contexts reveal
either parity in strand choice, or only modest disparity. On the other hand, the
highly biased resolutions observed in the case of tethered parallel junctions can
be explained by the non-equivalence in protein occupancy of the DNA arms of these
substrates and/or inefficient conversion of cleavage events to recombinants at
the tethered ends.
PMID- 10669598
TI - Extensive central disruption of a four-way junction on binding CCE1 resolving
enzyme.
AB - Junction-resolving enzymes are nucleases that are selective for the structure of
the four-way DNA junction that is important in genetic recombination. They
exhibit selectivity for the structure of the junction, but they also manipulate
the structure. Local disruption of DNA structure around the centre of the
junction by CCE1 of Saccharomyces cerevisiae has been investigated using 2
aminopurine fluorescence. On binding CCE1, 2-aminopurine bases located at the
point of strand exchange exhibit a large increase in fluorescence intensity (up
to 39-fold enhancement), consistent with complete unstacking. This was observed
for all positions around the centre of the junction, both 5' and 3' to the point
of strand exchange. Thymine bases complementary to the modified adenine bases
adjacent to the junction centre were strongly reactive to potassium permanganate.
The results indicate that binding of CCE1 results in a complete unpairing of the
four central base-pairs of the junction, with a lesser disruption of the next
base-pairs.
PMID- 10669599
TI - Sequence and expression of the kettin gene in Drosophila melanogaster and
Caenorhabditis elegans.
AB - Kettin is a large modular protein associated with thin filaments in the Z-disc
region of insect muscles. The sequence of a 21.3 kb contig of the Drosophila gene
has been determined. The corresponding protein sequence has 35 immunoglobulin
like (Ig) domains which are separated by shorter linker sequences, except near
the N and C termini of the molecule where linker sequences are short or missing.
This confirms a model in which each Ig domain binds to an actin protomer. The
Drosophila kettin gene is at 62C 1-3 on the third chromosome. Two P-element
insertions, l(3)j1D7 and l(3)rL182 are in the kettin gene, and complementation
tests showed that existing l(3)dre8 mutations are in the same gene. The RNA was
detected in wild-type Drosophila embryos at stage 11, first in the gut
invagination region of the mesoderm, and by stage 13 in both visceral and somatic
mesoderm. Somatic mesoderm expression became segmental at stage 13. RNA
expression was greatly reduced in embryos of P-element homozygotes but normal in
heterozygotes. The structure of the flight muscle in all the heterozygous mutants
was normal, including the myofibril-cuticle connections, and they were able to
fly. Kettin sequence homologous to the Drosophila protein, was identified in the
Caenorhabditis elegans genome database. The RNA was detected in pharyngeal, body
wall and anal depressor muscles of larvae and adult worms, as well as in the male
gonad. Antibody to insect kettin labelled the pharyngeal, body wall, anal
depressor and proximal gonadal muscles in adult worms. Body wall muscles were
labelled in an obliquely striated pattern consistent with the Z-disc localisation
in insect muscle. The relationship of kettin to D-titin, which has been assigned
to the same chromosomal locus in Drosophila, is discussed.
PMID- 10669600
TI - Direct visualisation of conformational changes in EF(0)F(1) by electron
microscopy.
AB - The isolated H(+)-ATPase from Escherichia coli (EF(0)F(1)) was investigated by
electron microscopy of samples of negatively stained monodisperse molecules,
followed by single-particle image processing. The resulting three-dimensional
maps showed that the F(1)-part is connected by a prominent stalk to a more
peripheral part of F(0). The F(1)-part showed stain-accessible cavities inside.
In three-dimensional maps from selected particles, a second stalk could be
detected which was thinner than the main stalk and is thought to correspond to
the stator.Three-dimensional maps of the enzyme in the absence and in the
presence of the substrate analogue adenyl-beta, gamma-imidodiphosphate (AMP-PNP)
were calculated. Upon binding of AMP-PNP the three-dimensional maps showed no
significant changes in the F(0)-part of EF(0)F(1), whereas a major conformational
change in the F(1)-part was observed. (1) The diameter of the F(1)-part decreased
upon binding of AMP-PNP mainly in the upper half of F(1). (2) Enzyme particles
prepared in the presence of AMP-PNP had a pointed cap at the top of the F(1)-part
which was missing in its absence. (3) The stain-accessible cavity inside the F(1)
part altered its pattern significantly.
PMID- 10669601
TI - Sepia officinalis hemocyanin: A refined 3D structure from field emission gun
cryoelectron microscopy.
AB - The extracellular respiratory pigment of the cuttlefish Sepia officinalis was
observed by cryoelectron microscopy with conventional LaB(6) and field emission
gun electron sources at 100 and 200 kV, respectively. Each image series was used
to compute one 3D reconstruction volume with correction of the contrast transfer
function by Wiener filtering. A strong boosting of the contrast was corrected by
band-pass filtering of the final volumes, and a qualitative gain in resolution
was observed when using the field emission gun electron microscope. In this
volume, a strong signal is present down to 1/18 A(-1) and some meaningful
information is obtained down to 1/12.5 A(-1). The complex is composed of five
pairs of polypeptide chains and resembles a hollow cylinder with five wall
oblique units and five inner arches. Three types of wall-wall connections termed
pillar P1 to P3 are visible in this volume and the four functional units present
in the arches are each linked to the wall by two arch-wall connections. The
dispositions of the functional units in the arches of Sepia and Octopus
hemocyanins share no common feature.
PMID- 10669602
TI - An EF-hand phage display study of calmodulin subdomain pairing.
AB - The interaction between the two EF-hands, EF3 and EF4, in the C-terminal domain
of vertebrate calmodulin is addressed using an EF-hand phage display library.
Significant specificity is observed in the presence of Ca(2+), as EF3-EF4
heterodimers are favored over EF3-EF3 and EF4-EF4 homodimers. Primarily EF4-type
(and not EF3-type) amino acids are selected when an EF3 peptide is used as the
target and vice versa. The results show that this specificity is promoted by
several factors. There are three positions, corresponding to Phe89, Ala102, and
Leu105, that are strongly selected as EF3-type hydrophobic residues with an EF4
target. When EF3 is the target peptide, EF4-type residues, Ile125, Tyr138 and
Phe141, are selected. Remarkably, this subset consists of the same three residue
positions in EF3 or EF4 and seems to be involved in specifying the heterodimer
preference in both cases. In addition, electrostatic repulsion between the acidic
monomers in an EF4 homodimer may further influence the preferred stability of
heterodimers. This hypothesis is based on the observation that positively charged
residues are strongly selected at four positions when EF4 is the target. A survey
of EF-hand pairs suggests that charge separation is a common way to achieve
efficient attraction of Ca(2+) without causing electrostatic repulsion between
the subdomains. No significant specificity of binding is observed in the ion free
state or in the presence of magnesium as no sequence is preferentially selected.
The residues at the interface between the two EF-hands are thus highly optimized
for the Ca(2+) bound state. At some residue positions, EF3-type amino acids are
chosen with EF3-target in the presence of Ca(2+). These residues are not involved
in the preference for heterodimer over homodimer formation, but represent key
positions to mutate in the intact domain to stabilize its Ca(2+)-bound state.
PMID- 10669603
TI - High copy display of large proteins on phage for functional selections.
AB - We have isolated mutations in the major coat protein P8 of M13 phage that greatly
increase the surface display of monomeric or oligomeric proteins. The monomeric
protein, human growth hormone (hGH), was fused to the N terminus of P8; libraries
of P8 variants were constructed and variants that increased hGH display were
selected by binding to the extracellular domain of the hGH receptor. The hGH-P8
fusion protein was found to be extremely tolerant of mutations, and a number of
P8 variants were found that increased display to levels that improved detection
of the hGH-P8 fusion by almost 100-fold. The increased display likely results
from better accommodation of the hGH-P8 fusion protein in the phage coat. Using
this high copy display format, it was possible for the first time to detect
variants of hGH with very weak affinities for the hGHbp (K(d)>1 microM). The
display of a tetrameric protein, streptavidin (approximately 50 kDa), was also
increased, suggesting the approach may be general to many proteins. The initial
product of a natural or invented selection from a naive library is often a weakly
functioning protein. These improvements in high copy display should facilitate
the broader goal for selection of proteins with novel functions.
PMID- 10669604
TI - Bacteriophage lambda display of complex cDNA libraries: a new approach to
functional genomics.
AB - We describe the construction and characterization of two lambda surface displayed
cDNA expression libraries derived from human brain and mouse embryo. cDNA inserts
were obtained by tagged random-priming elongation of commercially available cDNA
libraries and cloned into a novel lambda vector at the 3' end of the D capsid
protein gene, which produced highly complex repertoires (1x10(8) and 2x10(7)
phage). These libraries were affinity selected with a monoclonal antibody against
the neural specific factor GAP-43 and with polyclonal antibodies that recognize
the EMX1 and EMX2 homeoproteins. In both cases rapid identification of specific
clones was achieved, which demonstrates the great potential of the lambda display
system for generating affinity selectable cDNA libraries from complex genomes.
PMID- 10669605
TI - Structural basis of RXR-DNA interactions.
AB - The 9-cis retinoic acid receptor, RXR, binds DNA effectively as a homodimer or as
a heterodimer with other nuclear receptors. The DNA-binding sites for these RXR
complexes are direct repeats of a consensus sequence separated by one to five
base-pairs of intervening space. Here, we report the 2.1 A crystal structure of
the RXR-DNA-binding domain as a homodimer in complex with its idealized direct
repeat DNA target. The structure shows how a gene-regulatory site can induce
conformational changes in a transcription factor that promote homo-cooperative
assembly. Specifically, an alpha-helix in the T-box is disrupted to allow
efficient DNA-binding and subunit dimerization. RXR displays a relaxed mode of
sequence recognition, interacting with only three base-pairs in each hexameric
half-site. The structure illustrates how site selection is achieved in this large
eukaryotic transcription factor family through discrete protein-protein
interactions and the use of tandem DNA binding sites with characteristic
spacings.
PMID- 10669606
TI - X-ray structure of simian immunodeficiency virus integrase containing the core
and C-terminal domain (residues 50-293)--an initial glance of the viral DNA
binding platform.
AB - The crystal structure of simian immunodeficiency virus (SIV) integrase that
contains in a single polypeptide the core and the C-terminal deoxyoligonucleotide
binding domain has been determined at 3 A resolution with an R-value of 0.203 in
the space group P2(1)2(1)2(1). Four integrase core domains and one C-terminal
domain are found to be well defined in the asymmetric unit. The segment extending
from residues 114 to 121 assumes the same position as seen in the integrase core
domain of avian sarcoma virus as well as human immunodeficiency virus type-1 (HIV
1) crystallized in the absence of sodium cacodylate. The flexible loop in the
active site, composed of residues 141-151, remains incompletely defined, but the
location of the essential Glu152 residue is unambiguous. The residues from 210
218 that link the core and C-terminal domains can be traced as an extension from
the core with a short gap at residues 214-215. The C(alpha) folding of the C
terminal domain is similar to the solution structure of this domain from HIV-1
integrase. However, the dimeric form seen in the NMR structure cannot exist as
related by the non-crystallographic symmetry in the SIV integrase crystal. The
two flexible loops of the C-terminal domain, residues 228-236 and residues 244
249, are much better fixed in the crystal structure than in the NMR structure
with the former in the immediate vicinity of the flexible loop of the core
domain. The interface between the two domains encompasses a solvent-exclusion
area of 1500 A(2). Residues from both domains purportedly involved in DNA binding
are narrowly distributed on the same face of the molecule. They include Asp64,
Asp116, Glu152 and Lys159 from the core and Arg231, Leu234, Arg262, Arg263 and
Lys264 from the C-terminal domain. A model for DNA binding is proposed to bridge
the two domains by tethering the 228-236 loop of the C-terminal domain and the
flexible loop of the core.
PMID- 10669607
TI - Crystal structure of an active two-domain derivative of Rous sarcoma virus
integrase.
AB - Integration of retroviral cDNA is a necessary step in viral replication. The
virally encoded integrase protein and DNA sequences at the ends of the linear
viral cDNA are required for this reaction. Previous studies revealed that
truncated forms of Rous sarcoma virus integrase containing two of the three
protein domains can carry out integration reactions in vitro. Here, we describe
the crystal structure at 2.5 A resolution of a fragment of the integrase of Rous
sarcoma virus (residues 49-286) containing both the conserved catalytic domain
and a modulatory DNA-binding domain (C domain). The catalytic domains form a
symmetric dimer, but the C domains associate asymmetrically with each other and
together adopt a canted conformation relative to the catalytic domains. A binding
path for the viral cDNA is evident spanning both domain surfaces, allowing
modeling of the larger integration complexes that are known to be active in vivo.
The modeling suggests that formation of an integrase tetramer (a dimer of dimers)
is necessary and sufficient for joining both viral cDNA ends at neighboring sites
in the target DNA. The observed asymmetric arrangement of C domains suggests that
they could form a rotationally symmetric tetramer that may be important for
bridging integrase complexes at each cDNA end.
PMID- 10669608
TI - Crystal structures of Toxoplasma gondii adenosine kinase reveal a novel catalytic
mechanism and prodrug binding.
AB - Adenosine kinase (AK) is a key purine metabolic enzyme from the opportunistic
parasitic protozoan Toxoplasma gondii and belongs to the family of carbohydrate
kinases that includes ribokinase. To understand the catalytic mechanism of AK, we
determined the structures of the T. gondii apo AK, AK:adenosine complex and the
AK:adenosine:AMP-PCP complex to 2.55 A, 2.50 A and 1.71 A resolution,
respectively. These structures reveal a novel catalytic mechanism that involves
an adenosine-induced domain rotation of 30 degrees and a newly described anion
hole (DTXGAGD), requiring a helix-to-coil conformational change that is induced
by ATP binding. Nucleotide binding also evokes a coil-to-helix transition that
completes the formation of the ATP binding pocket. A conserved dipeptide, Gly68
Gly69, which is located at the bottom of the adenosine-binding site, functions as
the switch for domain rotation. The synergistic structural changes that occur
upon substrate binding sequester the adenosine and the ATP gi phosphate from
solvent and optimally position the substrates for catalysis. Finally, the 1.84 A
resolution structure of an AK:7-iodotubercidin:AMP-PCP complex reveals the basis
for the higher affinity binding of this prodrug over adenosine and thus provides
a scaffold for the design of new inhibitors and subversive substrates that target
the T. gondii AK.
PMID- 10669609
TI - Structures of adenylosuccinate synthetase from Triticum aestivum and Arabidopsis
thaliana.
AB - Catalyzing the first step in the de novo synthesis of adenylmonophosphate,
adenylosuccinate synthetase (AdSS) is a known target for herbicides and
antibiotics. We have purified and crystallized recombinant AdSS from Arabidopsis
thaliana and Tritium aestivum, expressed in Escherichia coli. The structures of
A. thaliana and T. aestivum AdSS in complex with GDP were solved at 2.9 A and 3.0
A resolution, respectively. Comparison with the known structures from E. coli
reveals that the overall fold is very similar to that of the E. coli protein. The
longer N terminus in the plant sequences is at the same place as the longer C
terminus of the E. coli sequence in the 3D structure. The GDP-binding sites have
one additional hydrogen-bonding partner, which is a plausible explanation for the
lower K(m) value. Due to its special position, this partner may also enable GTP
to initiate a conformational change, which was, in E. coli AdSS, exclusively
activated by ligands at the IMP-binding site. The dimer interfaces show up to six
hydrogen bonds and six salt-bridges more than in the E. coli structure, although
the contact areas have approximately the same size.
PMID- 10669610
TI - Structural basis for the higher Ca(2+)-activation of the regulated actin
activated myosin ATPase observed with Dictyostelium/Tetrahymena actin chimeras.
AB - Replacement of residues 228-230 or 228-232 of subdomain 4 in Dictyostelium actin
with the corresponding Tetrahymena sequence (QTA to KAY replacement: half chimera
1; QTAAS to KAYKE replacement: full chimera) leads to a higher Ca(2+)-activation
of the regulated acto-myosin subfragment-1 ATPase activity. The ratio of ATPase
activation in the presence of tropomyosin-troponin and Ca(2+) to that without
tropomyosin-troponin becomes about four times as large as the ratio for the wild
type actin. To understand the structural basis of this higher Ca(2+)-activation,
we have determined the crystal structures of the 1:1 complex of Dictyostelium
mutant actins (half chimera-1 and full chimera) with gelsolin segment-1 to 2.0 A
and 2.4 A resolution, respectively, together with the structure of wild-type
actin as a control. Although there were local changes on the surface of the
subdomain 4 and the phenolic side-chain of Tyr230 displaced the side-chain of
Leu236 from a non-polar pocket to a more solvent-accessible position, the
structures of the actin chimeras showed that the mutations in the 228-232 region
did not introduce large changes in the overall actin structure. This suggests
that residues near position 230 formed part of the tropomyosin binding site on
actin in actively contracting muscle. The higher Ca(2+)-activation observed with
A230Y-containing mutants can be understood in terms of a three-state model for
thin filament regulation in which, in the presence of both Ca(2+) and myosin
heads, the local changes of actin generated by the mutation (especially its
phenolic side-chain) facilitate the transition of thin filaments from a "closed"
state to an "open" state. Between 394 and 469 water molecules were identified in
the different structures and it was found that actin recognizes hydrated forms of
the adenine base and the Ca ion in the nucleotide binding site.
PMID- 10669611
TI - Bacteriophage T4 gene 59 helicase assembly protein binds replication fork DNA.
The 1.45 A resolution crystal structure reveals a novel alpha-helical two-domain
fold.
AB - The bacteriophage T4 gene 59 helicase assembly protein is required for
recombination-dependent DNA replication, which is the predominant mode of DNA
replication in the late stage of T4 infection. T4 gene 59 helicase assembly
protein accelerates the loading of the T4 gene 41 helicase during DNA synthesis
by the T4 replication system in vitro. T4 gene 59 helicase assembly protein binds
to both T4 gene 41 helicase and T4 gene 32 single-stranded DNA binding protein,
and to single and double-stranded DNA. We show here that T4 gene 59 helicase
assembly protein binds most tightly to fork DNA substrates, with either single or
almost entirely double-stranded arms. Our studies suggest that the helicase
assembly protein is responsible for loading T4 gene 41 helicase specifically at
replication forks, and that its binding sites for each arm must hold more than
six, but not more than 12 nucleotides. The 1.45 A resolution crystal structure of
the full-length 217-residue monomeric T4 gene 59 helicase assembly protein
reveals a novel alpha-helical bundle fold with two domains of similar size.
Surface residues are predominantly basic (pI 9.37) with clusters of acidic
residues but exposed hydrophobic residues suggest sites for potential contact
with DNA and with other protein molecules. The N-terminal domain has structural
similarity to the double-stranded DNA binding domain of rat HMG1A. We propose a
speculative model of how the T4 gene 59 helicase assembly protein might bind to
fork DNA based on the similarity to HMG1, the location of the basic and
hydrophobic regions, and the site size of the fork arms needed for tight fork DNA
binding. The fork-binding model suggests putative binding sites for the T4 gene
32 single-stranded DNA binding protein and for the hexameric T4 gene 41 helicase
assembly.
PMID- 10669612
TI - Crystal structures of an N-terminal fragment from Moloney murine leukemia virus
reverse transcriptase complexed with nucleic acid: functional implications for
template-primer binding to the fingers domain.
AB - Reverse transcriptase (RT) serves as the replicative polymerase for retroviruses
by using RNA and DNA-directed DNA polymerase activities coupled with a
ribonuclease H activity to synthesize a double-stranded DNA copy of the single
stranded RNA genome. In an effort to obtain detailed structural information about
nucleic acid interactions with reverse transcriptase, we have determined crystal
structures at 2.3 A resolution of an N-terminal fragment from Moloney murine
leukemia virus reverse transcriptase complexed to blunt-ended DNA in three
distinct lattices. This fragment includes the fingers and palm domains from
Moloney murine leukemia virus reverse transcriptase. We have also determined the
crystal structure at 3.0 A resolution of the fragment complexed to DNA with a
single-stranded template overhang resembling a template-primer substrate. Protein
DNA interactions, which are nearly identical in each of the three lattices,
involve four conserved residues in the fingers domain, Asp114, Arg116, Asn119 and
Gly191. DNA atoms involved in the interactions include the 3'-OH group from the
primer strand and minor groove base atoms and sugar atoms from the n-2 and n-3
positions of the template strand, where n is the template base that would pair
with an incoming nucleotide. The single-stranded template overhang adopts two
different conformations in the asymmetric unit interacting with residues in the
beta4-beta5 loop (beta3-beta4 in HIV-1 RT). Our fragment-DNA complexes are
distinct from previously reported complexes of DNA bound to HIV-1 RT but related
in the types of interactions formed between protein and DNA. In addition, the DNA
in all of these complexes is bound in the same cleft of the enzyme. Through site
directed mutagenesis, we have substituted residues that are involved in binding
DNA in our crystal structures and have characterized the resulting enzymes. We
now propose that nucleic acid binding to the fingers domain may play a role in
translocation of nucleic acid during processive DNA synthesis and suggest that
our complex may represent an intermediate in this process.
PMID- 10669613
TI - Solution structure and dynamics of the Rous sarcoma virus capsid protein and
comparison with capsid proteins of other retroviruses.
AB - The solution structure and dynamics of the recombinant 240 amino acid residue
capsid protein from the Rous sarcoma virus has been determined by NMR methods.
The structure was determined using 2200 distance restraints and 330 torsion angle
restraints, and the dynamics analysis was based on (15)N relaxation parameters
(R(1), R(2), and (1)H-(15)N NOE) measured for 153 backbone amide groups. The
monomeric protein consists of independently folded N- and C-terminal domains that
comprise residues Leu14-Leu146 and Ala150-Gln226, respectively. The domains
exhibit different rotational correlation times (16.6(+/-0.1) ns and 12.6(+/-0.1)
ns, respectively), are connected by a flexible linker (Ala147-Pro149), and do not
give rise to inter-domain NOE values, indicating that they are dynamically
independent. Despite limited sequence similarity, the structure of the Rous
sarcoma virus capsid protein is similar to the structures determined recently for
the capsid proteins of retroviruses belonging to the lentivirus and human T-cell
leukemia virus/bovine leukemia virus genera. Structural differences that exist in
the C-terminal domain of Rous sarcoma virus capsid relative to the other capsid
proteins appear to be related to the occurrence of conserved cysteine residues.
Whereas most genera of retroviruses contain a pair of conserved and essential
cysteine residues in the C-terminal domain that appear to function by forming an
intramolecular disulfide bond during assembly, the Rous sarcoma virus capsid
protein does not. Instead, the Rous sarcoma virus capsid protein contains a
single cysteine residue that appears to be conserved among the avian C-type
retroviruses and is positioned in a manner that might allow the formation of an
intermolecular disulfide bond during capsid assembly.
PMID- 10669614
TI - Electrostatic dependence of the thrombin-thrombomodulin interaction.
AB - The rate constants for the binding interaction between thrombin and a fully
active fragment of its anticoagulant cofactor, thrombomodulin, have been
determined by surface plasmon resonance. At physiological ionic strength, the
k(a) was 6.7x10(6) M(-1) s(-1 )and the dissociation rate constant was 0.033 s(
1). These extremely fast association and dissociation rates resulted in an
overall binding equilibrium constant of 4.9 nM, which is similar to previously
reported values. Changing the ionic strength from 100 mM to 250 mM NaCl caused a
tenfold decrease in the association rate while the dissociation rate did not
change significantly. A similar effect was observed with tetramethylammonium
chloride. A Debye-Huckel plot of the data had a slope of -6 and an intercept at 0
ionic strength of 10(9) M(-1) s(-1). The same slope and intercept were obtained
for data that was collected in the presence of glycerol to slow the association
rates. These results show that the thrombin-TM456 interaction is extremely rapid
and nearly completely electrostatically steered. An association model is
presented in which TM456 approaches thrombin along the direction of the thrombin
molecular dipole.
PMID- 10669615
TI - Energetics of a strongly pH dependent RNA tertiary structure in a frameshifting
pseudoknot.
AB - Retroviruses employ -1 translational frameshifting to regulate the relative
concentrations of structural and non-structural proteins critical to the viral
life cycle. The 1.6 A crystal structure of the -1 frameshifting pseudoknot from
beet western yellows virus reveals, in addition to Watson-Crick base-pairing,
many loop-stem RNA tertiary structural interactions and a bound Na(+).
Investigation of the thermodynamics of unfolding of the beet western yellows
virus pseudoknot reveals strongly pH-dependent loop-stem tertiary structural
interactions which stabilize the molecule, contributing a net of DeltaH
approximately -30 kcal mol(-1) and DeltaG degrees (37) of -3.3 kcal mol(-1) to a
total DeltaH and DeltaG degrees (37) of -121 and -16 kcal mol(-1), respectively,
at pH 6.0, 0.5 M K(+) by DSC. Characterization of mutant RNAs supports the
presence of a C8(+).G12-C26 loop 1-stem 2 base-triple (pK(a)=6.8), protonation of
which contributes nearly -3.5 kcal mol(-1) in net stability in the presence of a
wild-type loop 2. Substitution of the nucleotides in loop 2 with uridine bases,
which would eliminate the minor groove triplex, destroys pseudoknot formation. An
examination of the dependence of the monovalent ion and type on melting profiles
suggests that tertiary structure unfolding occurs in a manner quantitatively
consistent with previous studies on the stabilizing effects of K(+), NH(4)(+) and
Na(+) on other simple duplex and pseudoknotted RNAs.
PMID- 10669616
TI - Dimerisation mutants of Lac repressor. II. A single amino acid substitution,
D278L, changes the specificity of dimerisation.
AB - Assembly of the lactose repressor tetramer involves two subunit interfaces, the C
terminal heptad repeats, and the monomer-monomer interface. Dimerisation between
two monomers of Lac repressor of Escherichia coli lacking the two C-terminal
heptad repeats occurs through the interactions between three alpha-helices of
each monomer, which form a highly hydrophobic interface. Residues possibly
involved in specific dimer formation are known from X-ray studies and from the
phenotypes of more than 4000 single amino acid substitutions. During the
examination of numerous mutants within the dimerisation interface of Lac
repressor, we found that substitution of one amino acid, D278 to leucine, is
sufficient to change the specificity of dimerisation. Analysis of this single
substitution indicates that D278L mutant Lac repressor represses like wild-type.
However, it no longer forms heterodimers with wild-type Lac repressor.
PMID- 10669617
TI - Conformational changes in serpins: I. The native and cleaved conformations of
alpha(1)-antitrypsin.
AB - The serpins (SERine Proteinase INhibitors) are a family of proteins with
important physiological roles, including but not limited to the inhibition of
chymotrypsin-like serine proteinases. The inhibitory mechan- ism involves a large
conformational change known as the S-->R (stressed-->relaxed) transition. The
largest structural differences occur in a region around the scissile bond called
the reactive centre loop: In the native (S) state, the reactive centre is
exposed, and is free to interact with proteinases. In inhibitory serpins, in the
cleaved (R) state the reactive centre loop forms an additional strand within the
beta-sheet. The latent state is an uncleaved state in which the intact reactive
centre loop is integrated into the A sheet as in the cleaved form, to give an
alternative R state. The serpin structures illustrate detailed control of
conformation within a single protein. Serpins are also an unusual family of
proteins in which homologues have native states with different folding
topologies. Determination of the structures of inhibitory serpins in multiple
conformational states permits a detailed analysis of the mechanism of the S-->R
transition, and of the way in which a single sequence can form two stabilised
states of different topology. Here we compare the conformations of alpha(1)
antitrypsin in native and cleaved states. Many protein conformational changes
involve relative motions of large rigid subunits. We determine the rigid subunits
of alpha(1)-antitrypsin and analyse the changes in their relative position and
orientation. Knowing that the conformational change is initiated by cleavage at
the reactive centre, we describe a mechanism of the S-->R transition as a logical
sequence of mechanical effects, even though the transition likely proceeds in a
concerted manner.
PMID- 10669618
TI - Substrate binding site of naphthalene 1,2-dioxygenase: functional implications of
indole binding.
AB - The three-dimensional structure of the aromatic hydroxylating enzyme naphthalene
dioxygenase (NDO) from Pseudomonas sp. NCIB 9816-4 was recently determined. The
refinement of the structure together with cyclic averaging showed that in the
active site of the enzyme there is electron density for a flat aromatic compound.
This compound appears to be an indole adduct, which in Escherichia coli is
derived from tryptophan present in the rich culture medium. An indole-dioxygen
adduct has been built which fits the electron density convincingly. Support for
this interpretation was obtained from crystals of the enzyme purified from cells
grown in the absence of tryptophan which had an empty substrate pocket. These
types of crystals were soaked in indole solutions and the position of indole in
this complex was similar to the corresponding part in the modelled indole-oxygen
adduct. This suggests that a peroxide bound to iron end-on attacks the substrate
and forms this intermediate. The substrate position has implications for the
substrate specificity of the enzyme. Docking studies with indole, naphthalene and
biphenyl inside the substrate pocket of NDO suggest the presence of subpockets
where the one close to the active site iron is reserved for the binding of the
aromatic ring which is hydroxylated upon catalysis. The plausible location for
the binding of dioxygen is between this pocket and the catalytic iron. This is in
accordance with the enantiospecificity of the products.
PMID- 10669619
TI - Active-site gorge and buried water molecules in crystal structures of
acetylcholinesterase from Torpedo californica.
AB - Buried water molecules and the water molecules in the active-site gorge are
analyzed for five crystal structures of acetylcholinesterase from Torpedo
californica in the resolution range 2.2-2.5 A (native enzyme, and four inhibitor
complexes). A total of 45 buried hydration sites are identified, which are
populated with between 36 and 41 water molecules. About half of the buried water
is located in a distinct region neighboring the active-site gorge. Most of the
buried water molecules are very well conserved among the five structures, and
have low displacement parameters, B, of magnitudes similar to those of the main
chain atoms of the central beta-sheet structure. The active-site gorge of the
native enzyme is filled with over 20 water molecules, which have poor hydrogen
bond coordination with an average of 2.9 polar contacts per water molecule. Upon
ligand binding, distinct groups of these water molecules are displaced, whereas
the others remain in positions similar to those that they occupy in the native
enzyme. Possible roles of the buried water molecules are discussed, including
their possible action as a lubricant to allow large-amplitude fluctuations of the
loop structures forming the gorge wall. Such fluctuations are required to
facilitate traffic of substrate, products and water molecules to and from the
active-site. Because of their poor coordination, the gorge water molecules can be
considered as "activated" as compared to bulk water. This should allow their easy
displacement by incoming substrate. The relatively loose packing of the gorge
water molecules leaves numerous small voids, and more efficient space-filling by
substrates and inhibitors may be a major driving force of ligand binding.
PMID- 10669620
TI - ACE gene polymorphism and coronary artery disease: A question of persuasion or
statistical confusion?
PMID- 10669621
TI - IRS-1 variant: A new risk factor for coronary artery disease?
PMID- 10669622
TI - Congenital disorders of platelet signal transduction.
PMID- 10669623
TI - Macrophage scavenger receptor class A: A multifunctional receptor in
atherosclerosis.
AB - In atherogenesis, elevated plasma levels of low density lipoprotein (LDL) lead to
the chronic presence of LDL in the arterial wall. There, LDL is modified (eg,
oxidized), and these modified lipoproteins activate endothelial cells, which
attract circulating monocytes. These monocytes enter the vessel wall,
differentiate into macrophages, and subject the modified lipoproteins to
endocytosis through scavenger receptor pathways. This unrestricted uptake, which
is not limited by intracellular cholesterol levels, eventually leads to the
formation of lipid-filled foam cells, the initial step in atherosclerosis.
Macrophage scavenger receptor class A (SRA) is thought to be one of the main
receptors involved in foam cell formation, mediating the influx of lipids into
the macrophages. In addition to this role in modified lipoprotein uptake by
macrophages, the SRA has been shown to be important in the inflammatory response
in host defense, cellular activation, adhesion, and cell-cell interaction. Given
the importance of these processes in atherogenesis, these latter functions may
prove to make the SRA a multifunctional player in the atherosclerotic process.
PMID- 10669624
TI - Expression of Fas ligand in arteries of hypercholesterolemic rabbits accelerates
atherosclerotic lesion formation.
AB - Fas ligand (FasL) is expressed by cells of the arterial wall and is present in
human atherosclerotic lesions. However, the role of FasL in modifying the
initiation and progression of atherosclerosis is unclear. To investigate the role
of arterial FasL expression in the development of atherosclerosis, we first
established a model of primary lesion formation in rabbit carotid arteries. In
this model, infusion of adenoviral vectors into surgically isolated, nondenuded
arteries of hypercholesterolemic rabbits leads to the formation of human-like
early atherosclerotic lesions. Expression of FasL in arterial endothelium in this
model decreased T-cell infiltration and expression of vascular cell adhesion
molecule-1 but did not affect expression of intercellular adhesion molecule-1.
Intimal lesions grew more rapidly in FasL-transduced arteries than in arteries
transduced with a control adenovirus that did not express a transgene. Total
intimal macrophage accumulation was increased in FasL-transduced arteries;
however, the proportion of lesion area occupied by macrophages was not elevated.
The accelerated lesion growth was primarily due to the accumulation of intimal
smooth muscle cells with a synthetic proliferative phenotype. There was no
significant apoptosis in FasL-transduced or control arteries and no granulocytic
infiltrates. Thus, the net result of elevated FasL expression is to accelerate
atherosclerotic lesion growth by increasing lesion cellularity. Vascular
expression of FasL may contribute to the progression of atherosclerosis.
PMID- 10669625
TI - Vascular endothelial cells and smooth muscle cells differ in expression of Fas
and Fas ligand and in sensitivity to Fas ligand-induced cell death: implications
for vascular disease and therapy.
AB - Fas ligand (FasL) is a death factor that induces apoptosis in cells bearing its
receptor, Fas. Fas and FasL have been detected in the vessel wall, and it has
been proposed that Fas-mediated apoptosis has a role in physiological and
pathological cell turnover in the vasculature. Here, we evaluated the expression
of Fas in the presence and absence of cytokines on both endothelial cells (ECs)
and vascular smooth muscle cells (VSMCs). We also examined the sensitivity of ECs
and VSMCs to Fas-mediated apoptosis induced by exposure to multiple Fas agonists:
soluble FasL, anti-Fas antibody, and membrane-bound FasL resulting from
transduction with a replication-defective adenovirus expressing FasL (Adeno
FasL). Cell-surface FasL expression was detected on human ECs with the use of 4
anti-FasL antibodies, whereas cell-surface FasL expression was not detected on
VSMCs. Unstimulated ECs expressed relatively low levels of Fas, but expression
was upregulated after treatment with tumor necrosis factor-alpha (TNF-alpha) or
interferon gamma (IFN-gamma). In contrast, VSMCs expressed relatively high levels
of Fas, and treatment with TNF-alpha or IFN-gamma induced little or no
upregulation under the conditions of these assays. ECs were resistant to death
after exposure to soluble FasL or agonist anti-Fas antibody and also after
infection with Adeno-FasL in the presence or absence of cytokine treatment. In
contrast, VSMCs remained viable in the presence of soluble FasL or agonist anti
Fas antibody, but they underwent apoptosis after infection with Adeno-FasL. IFN
gamma enhanced Adeno-FasL-induced death of VSMCs, but TNF-alpha did not. These
findings provide insights about the potential role of Fas-mediated apoptosis in
the vessel wall and suggest strategies to treat proliferative vascular diseases
by exploiting the differential sensitivity of ECs and VSMCs to FasL-induced cell
death.
PMID- 10669626
TI - Warfarin-induced artery calcification is accelerated by growth and vitamin D.
AB - The present studies demonstrate that growth and vitamin D treatment enhance the
extent of artery calcification in rats given sufficient doses of Warfarin to
inhibit gamma-carboxylation of matrix Gla protein, a calcification inhibitor
known to be expressed by smooth muscle cells and macrophages in the artery wall.
The first series of experiments examined the influence of age and growth status
on artery calcification in Warfarin-treated rats. Treatment for 2 weeks with
Warfarin caused massive focal calcification of the artery media in 20-day-old
rats and less extensive focal calcification in 42-day-old rats. In contrast, no
artery calcification could be detected in 10-month-old adult rats even after 4
weeks of Warfarin treatment. To directly examine the importance of growth to
Warfarin-induced artery calcification in animals of the same age, 20-day-old rats
were fed for 2 weeks either an ad libitum diet or a 6-g/d restricted diet that
maintains weight but prevents growth. Concurrent treatment of both dietary groups
with Warfarin produced massive focal calcification of the artery media in the ad
libitum-fed rats but no detectable artery calcification in the restricted-diet,
growth-inhibited group. Although the explanation for the association between
artery calcification and growth status cannot be determined from the present
study, there was a relationship between higher serum phosphate and susceptibility
to artery calcification, with 30% higher levels of serum phosphate in young, ad
libitum-fed rats compared with either of the groups that was resistant to
Warfarin-induced artery calcification, ie, the 10-month-old rats and the
restricted-diet, growth-inhibited young rats. This observation suggests that
increased susceptibility to Warfarin-induced artery calcification could be
related to higher serum phosphate levels. The second set of experiments examined
the possible synergy between vitamin D and Warfarin in artery calcification. High
doses of vitamin D are known to cause calcification of the artery media in as
little as 3 to 4 days. High doses of the vitamin K antagonist Warfarin are also
known to cause calcification of the artery media, but at treatment times of 2
weeks or longer yet not at 1 week. In the current study, we investigated the
synergy between these 2 treatments and found that concurrent Warfarin
administration dramatically increased the extent of calcification in the media of
vitamin D-treated rats at 3 and 4 days. There was a close parallel between the
effect of vitamin D dose on artery calcification and the effect of vitamin D dose
on the elevation of serum calcium, which suggests that vitamin D may induce
artery calcification through its effect on serum calcium. Because Warfarin
treatment had no effect on the elevation in serum calcium produced by vitamin D,
the synergy between Warfarin and vitamin D is probably best explained by the
hypothesis that Warfarin inhibits the activity of matrix Gla protein as a
calcification inhibitor. High levels of matrix Gla protein are found at sites of
artery calcification in rats treated with vitamin D plus Warfarin, and chemical
analysis showed that the protein that accumulated was indeed not gamma
carboxylated. These observations indicate that although the gamma
carboxyglutamate residues of matrix Gla protein are apparently required for its
function as a calcification inhibitor, they are not required for its accumulation
at calcification sites.
PMID- 10669627
TI - Lesions in ryanodine channels in smooth muscle cells exposed to oxidized low
density lipoprotein.
AB - The purpose of the present investigation was to investigate the subcellular basis
responsible for the loss of vasoreactivity in atherosclerotic vessels. We have
chosen to focus on the potential of oxidized low density lipoprotein (oxLDL), an
important atherogenic agent, to alter sarcoplasmic reticulum (SR) structure and
function. Vascular smooth muscle cells (VSMCs) were exposed for 1 to 6 days to
low concentrations of minimally oxidized LDL. ATP was used to probe SR function
in VSMCs. ATP can increase [Ca(2+)](i) in control VSMCs because of a release of
Ca(2+) from the SR. However, after chronic exposure to oxLDL, cells lose their
ability to increase [Ca(2+)](i) in response to ATP. These cells also exhibit a
depressed rise in [Ca(2+)](i) after exposure to ryanodine. These effects were
associated with a decreased immunoreactivity for the ryanodine-sensitive Ca(2+)
release channels in the SR of oxLDL-treated cells. Immunohistochemical analysis
of aortic sections obtained from rabbits fed a cholesterol-supplemented diet
revealed a significant decrease in the immunoreactivity for ryanodine channels in
the plaque and in the medial layer underlying the plaque. In summary, our data
identify oxLDL as a component within the atherosclerotic milieu capable of
inducing a decrease in smooth muscle ryanodine channel density. This alteration
is associated with a significant defect in the ability of the SR within the
smooth muscle cell to regulate Ca(2+). These lesions may contribute to the
altered vasoreactivity exhibited by atherosclerotic vessels.
PMID- 10669628
TI - Mouse model of femoral artery denudation injury associated with the rapid
accumulation of adhesion molecules on the luminal surface and recruitment of
neutrophils.
AB - Techniques of arterial injury commonly used in animals to mimic endovascular
procedures are not suitable for small mouse arteries. This has limited
examination of the response to arterial injury in genetically modified mice. We
therefore sought to develop a model of transluminal injury to the mouse femoral
artery that would be reproducible and result in substantial levels of intimal
hyperplasia. Mice of the C57BL/6 strain underwent bilateral femoral artery
denudation by passage of an angioplasty guidewire. Intimal hyperplasia was
observed in 10% of injured arteries at 1 week, in 88% at 2 weeks, and in 90% at 4
weeks. The mean intimal-to-medial area ratio reached 1.1+/-0.1 at 4 weeks. No
intimal proliferation was found in control sham-operated arteries. One hour after
injury, the denuded surface was covered with platelets and leukocytes,
predominantly neutrophils. This was associated with the accumulation of P
selectin, intercellular adhesion molecule-1, and vascular cell adhesion molecule
1. Expression of these adhesion molecules was not seen in the underlying medial
smooth muscle cells. At 24 hours, few neutrophils remained on the denuded
surface. At 1 week, macrophages and platelets were present in the vessel wall,
partially covered by regenerated endothelium. Transluminal wire injury to the
mouse femoral artery induces abundant intimal hyperplasia formation by 2 and 4
weeks and elicits the rapid accumulation of leukocytes and adhesion molecules on
the denuded luminal surface. This model will be a valuable tool to study arterial
injury in genetically modified mouse models.
PMID- 10669629
TI - Mouse model of transplant arteriosclerosis: role of intercellular adhesion
molecule-1.
AB - Transplant-accelerated arteriosclerosis in coronary arteries is the major
limitation to long-term survival of patients with heart transplantation. The
pathogenesis of this disease is not fully understood. Herein, we describe a
simplified model of artery allografts in the mouse that allows us to take
advantage of transgenic, knockout, or mutant animals. Common carotid arteries or
aortic vessels were end-to-end allografted into carotid arteries between C57BL/6J
and BALB/c mice. Neointimal lesions were observed as early as 2 weeks after
surgery and had progressed at 4 and 6 weeks postoperatively. The lumen of grafted
arteries was significantly narrowed due to neointima hyperplasia 4 weeks after
transplantation. Using this model, we studied the role of intercellular adhesion
molecule-1 (ICAM-1) in the development of transplant arteriosclerosis in ICAM-1
deficient mice. Neointimal lesions of artery grafts from ICAM-1 -/- C57BL/6J to
BALB/c mice were reduced up to 60% compared with wild-type controls. MAC-1
(CD11b/18)-positive cells adhering to the surface of ICAM-1 -/- artery grafts
were significantly less as identified by en face immunofluorescence, and these
positive cells were more abundant in intimal lesions of artery grafts in wild
type mice. Furthermore, the major cell component of neointimal lesions 4 weeks
after surgery was found to be alpha-actin-positive smooth muscle cells, which
were significantly reduced in lesions of ICAM-1 -/- artery grafts. Thus, this
model has been proven to be useful for understanding the mechanism of transplant
arteriosclerosis. Our findings demonstrate that ICAM-1 is critical in the
development of allograft arteriosclerosis via mediation of leukocyte adhesion to,
and infiltration into, the vessel wall.
PMID- 10669630
TI - Adhesion of monocyte very late antigen-4 to endothelial vascular cell adhesion
molecule-1 induces interleukin-1beta-dependent expression of interleukin-6 in
endothelial cells.
AB - In atheroma, T cell-derived interferon-gamma (INF-gamma) stimulates endothelial
cells and facilitates recruitment of monocytes. We investigated potential
mechanisms by which these interactions could contribute to local and systemic
inflammatory responses. Specifically, we analyzed the expression of interleukin
(IL)-1beta and IL-6 in both cell types after coculture, the relevant adhesion
molecules in this interaction, and transcriptional control by NF-kappaB. We
studied coculture of purified peripheral blood monocytes with human umbilical
vein endothelial cells (HUVECs), which were stimulated with INF-gamma (10(6) U/L)
to model the activated endothelium of atherosclerotic lesions. Coculture of
monocytes with activated HUVECs resulted in release of IL-1beta (40. 6+/-3 pg/24
h, P=0.002) and IL-6 (46.6+/-7 ng/24 h, P=0.0015). Electrophoretic mobility gel
shift assay and Northern blotting in each cell type separately revealed NF-kappaB
activation in both cell types, IL-1beta mRNA expression predominantly in
monocytes, and IL-6 mRNA expression predominantly in HUVECs. The endothelial IL-6
release was IL-1-dependent, because it was suppressed by IL-1 receptor
antagonist. Experiments with blocking antibodies demonstrated that binding of
monocyte very late antigen-4 (VLA-4) to endothelial vascular cell adhesion
molecule-1 (VCAM-1) was necessary for the induction of IL-1beta in monocytes.
Binding of monocyte VLA-4 to endothelial VCAM-1 induces NF-kappaB activation in
both cell types with expression and release of IL-1beta by monocytes, which in
turn stimulates endothelial release of IL-6. The beta(1)-integrin-mediated
expression of IL-1beta and IL-6 could contribute to local and systemic
inflammatory reactions in atherosclerosis.
PMID- 10669631
TI - CD9 participates in endothelial cell migration during in vitro wound repair.
AB - CD9, a widely expressed membrane protein of the tetraspanin family, has been
implicated in diverse functions, such as signal transduction, cell adhesion, and
cell motility. We tested the effects of an anti-CD9 monoclonal antibody (ALMA.1)
on the migration and proliferation of human vascular endothelial cells (ECs)
during repair of an in vitro mechanical wound mimicking angiogenic processes.
ALMA.1 induced dose-dependent inhibition of wound repair with a 35+/-1.5%
decrease at 20 microg/mL. Only cell migration was affected, because the rate of
proliferation of ECs at the lesion margin was not modified and because the
inhibition of repair was also observed for nonproliferating irradiated ECs.
Monoclonal antibodies against CD63 tetraspanin (H5C6) and control mouse IgG (MOPC
21) were inactive. CD9, one of the most abundant proteins at the surface of ECs,
colocalized with beta(1) or beta(3) integrins on EC membranes in double-labeling
immunofluorescence experiments with ALMA.1 and an anti-beta(1) (4B4) or anti
beta(3) (SDF.3) monoclonal antibody. Moreover, ALMA.1 and 4B4 had additive
inhibitory effects on lesion repair, whereas 4B4 alone also inhibited EC
proliferation. In transmembrane Boyden-type assays, ALMA.1 induced dose-dependent
inhibition of EC migration toward fibronectin and vitronectin with 45+/-6% and
31+/-10% inhibition, respectively, at 100 microg/mL. 4B4 inhibited migration
toward fibronectin at 10 microg/mL but had no effect in the case of vitronectin.
Adhesion of ECs to immobilized anti-CD9 monoclonal antibodies induced tyrosine
phosphorylated protein levels similar to those observed during interactions with
beta(1) or beta(3) integrins. These results point to the involvement of CD9 in EC
adhesion and migration during lesion repair and angiogenesis, probably through
cooperation with integrins. As such, CD9 is a potential target to inhibit
angiogenesis in metastatic and atherosclerotic processes.
PMID- 10669632
TI - Insulin-like growth factor binding protein-4 expression is decreased by
angiotensin II and thrombin in rat aortic vascular smooth muscle cells.
AB - Insulin-like growth factor-I (IGF-I) is a ubiquitous peptide that regulates
cellular growth and differentiation and is involved in vascular proliferative
responses. The effects of IGF-I are modulated by several IGF-I binding proteins
(IGFBPs), including IGFBP-4, the main IGFBP produced by vascular smooth muscle
cells (VSMCs). We have previously shown that angiotensin II (Ang II)-induced and
thrombin-induced mitogenesis in VSMCs is dependent on autocrine IGF-I. In
addition, we have demonstrated that IGF-I and IGFBP-4 mRNA levels are upregulated
in the hypertensive aorta of abdominally coarcted rats, a high-renin hypertension
model. To obtain further insight into the IGF-I system and to specifically study
changes in IGFBP-4, a known inhibitor of IGF-I action, VSMCs were incubated with
Ang II or thrombin. Compared with control, Ang II induced an 87+/-2%
downregulation of IGFBP-4 mRNA levels at 24 hours, with a 61+/-6% decrease of
IGFBP-4 levels, as determined by Western ligand blot analysis. Thrombin had the
same depressor effects (87+/-2% for the mRNA levels and 61+/-3% for the protein
levels). Ang II and thrombin coincubation with (125)I-IGFBP-4 in the conditioned
media failed to reveal any increase in fragmentation, indicating that proteolytic
cleavage of IGFBP-4 was not involved in the observed effects. Exogenous
recombinant human IGFBP-4 decreased thrombin-induced DNA synthesis of human
aortic VSMCs by 64%, whereas anti-IGFBP-4 antibody potentiated thrombin-induced
DNA synthesis. These data suggest that downregulation of IGFBP-4 expression in
VSMCs may play a critical role in vascular growth response to Ang II and thrombin
in normal and diseased states, by increasing the bioavailability of IGF-I for its
cell-surface receptor.
PMID- 10669633
TI - Zinc finger transcription factor Egr-1 activates Flt-1 gene expression in THP-1
cells on induction for macrophage differentiation.
AB - Activation of macrophages is a hallmark of atherosclerosis. Stimulation of human
monocytic leukemia THP-1 cells with phorbol 12-myristate 13-acetate (PMA) is
known to induce a variety of genes whose function is relevant to activated
macrophages. Flt-1, a receptor tyrosine kinase for vascular endothelial growth
factor, is expressed in macrophages as well as in endothelial cells and mediates
the biological response to vascular endothelial growth factor. In this study, we
investigated the molecular mechanisms underlying the inducible expression of the
flt-1 gene during the activation of THP-1 cells. Reverse transcription-polymerase
chain reaction analysis showed that exposure of THP-1 cells to PMA increases flt
1 mRNA and protein levels. A transfected reporter gene, consisting of the human
flt-1 promoter region coupled to the luciferase gene, indicated a direct effect
of PMA on transcriptional activity. Transfection analysis of a series of 5'
deletion constructs and site-directed mutants localized the PMA-responsive region
to a DNA stretch from -174 to -166, which represents overlapping Egr-1/Sp1
transcription factor-binding sites. Competitive gel mobility shift assays and
supershift assays showed that PMA induces the binding of Egr-1 to this site.
Consistent with these findings, the Egr-1 expression plasmid strongly induced flt
1 promoter activity in a sequence-specific manner. Taken together, our data
demonstrate that PMA induces flt-1 gene transcription through an induction of Egr
1 in THP-1 cells, thus providing new evidence that the flt-1 gene is a direct
target of Egr-1, the transcription factor primarily induced on macrophage
differentiation.
PMID- 10669634
TI - Convergence of redox-sensitive and mitogen-activated protein kinase signaling
pathways in tumor necrosis factor-alpha-mediated monocyte chemoattractant protein
1 induction in vascular smooth muscle cells.
AB - Monocyte chemoattractant protein-1 (MCP-1) is an important component of the
inflammatory response of the vessel wall and has been shown to be regulated by
cytokines, such as tumor necrosis factor-alpha (TNF-alpha). However, the precise
signaling pathways leading to MCP-1 induction have not been fully elucidated in
vascular smooth muscle cells (VSMCs). Cytokine signal transduction involves
protein kinases as well as reactive oxygen species (ROS). The relation between
these 2 factors is not clear. In this study, we show that TNF-alpha induces a
parallel phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2)
and p38 mitogen-activated protein kinase (p38MAPK) and increases MCP-1 mRNA
expression in cultured VSMCs. Inhibition of ERK1/2 but not p38MAPK caused a
partial attenuation of MCP-1 induction (43+/-10% inhibition). Incubation of VSMCs
with multiple antioxidants (diphenylene iodonium, liposomal superoxide dismutase,
catalase, N-acetylcysteine, dimethylthiourea, and pyrrolidine dithiocarbamate)
had no effect on TNF-alpha-mediated MCP-1 upregulation. However, simultaneous
blockade of the ERK1/2 and ROS pathways by using PD098059 combined with
diphenylene iodonium or N-acetylcysteine potently enhanced the ability of MAPK
kinase inhibitors to abrogate MCP-1 mRNA expression (100+/-2% inhibition). Thus,
parallel ROS-dependent and ERK1/2-dependent pathways converge to regulate TNF
alpha-induced MCP-1 gene expression in VSMCs. These data unmask a complex but
organized integration of ROS and protein kinases that mediates cytokine-induced
vascular inflammatory gene expression.
PMID- 10669635
TI - Inducible expression of manganese superoxide dismutase by phorbol 12-myristate 13
acetate is mediated by Sp1 in endothelial cells.
AB - The expression of manganese superoxide dismutase (Mn-SOD), an important component
of the cellular defense system against oxidative stress, is induced in response
to a variety of stimuli, including cytokines and phorbol esters, in endothelial
cells. To define the molecular mechanisms regulating the expression of Mn-SOD, we
have characterized the promoter of the human Mn-SOD gene. In calf pulmonary
artery endothelial cells, phorbol 12-myristate 13-acetate (PMA) gradually
increased Mn-SOD mRNA levels, with a peak at 6 to 12 hours after stimulation. The
increase in Mn-SOD mRNA was significantly inhibited by a protein kinase C (PKC)
inhibitor (calphostin C) but not by a mitogen-activated protein kinase kinase-1
inhibitor (PD98059) or a p38 mitogen-activated protein kinase inhibitor
(SB203580). By reporter gene transfection experiments of a series of promoter
deletions and site-directed mutation constructs, we found 2 consensus Sp1 binding
sequences located at -97 and at -77 to play an important role in PMA-induced Mn
SOD transcription. Electrophoretic gel mobility shift assays have indicated that
this sequence serves as an Sp1 binding site. Northern and Western blot analysis
has revealed that PMA-induced promoter activity of Mn-SOD correlates with an
increased expression of Sp1. Nuclear proteins from PMA-treated calf pulmonary
artery endothelial cells displayed an increased DNA binding to the Sp1 site.
Furthermore, the Mn-SOD promoter was activated either by overexpression of Sp1 or
the constitutively activated form of PKCbeta in an Sp1 site-dependent manner.
These results suggest that PMA stimulates transcription of the Mn-SOD gene
through an increase in Sp1 expression and thus implicate Sp1 as an effector
mediating the PKC-signaling pathway elicited by extracellular signals.
PMID- 10669636
TI - Insulin-mediated stimulation of protein kinase Akt: A potent survival signaling
cascade for endothelial cells.
AB - Insulin exerts potent antiapoptotic effects in neuronal cells and has been
suggested to promote angiogenesis. Therefore, we investigated whether insulin
inhibits tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis in human
umbilical vein endothelial cells (HUVECs). Because insulin has been shown to
stimulate the protein kinase Akt, we investigated whether activation of Akt
contributes to the apoptosis-suppressive effect of insulin and characterized the
downstream signaling pathway. Incubation with insulin dose-dependently prevented
apoptosis induced by TNF-alpha (50 ng/mL). The extent of apoptosis suppression by
insulin was similar to the effect of vascular endothelial growth factor.
Pharmacological inhibition of Akt activation or overexpression of a dominant
negative Akt mutant prevented the antiapoptotic effect of insulin. Furthermore,
we investigated the effect of TNF-alpha on Akt phosphorylation by Western blot
analysis with the use of a phosphospecific Akt antibody. Incubation of HUVECs
with TNF-alpha induced a marked dephosphorylation of Akt. Insulin counteracted
this TNF-alpha-induced dephosphorylation of Akt. Furthermore, we investigated the
downstream signaling events. Akt has been shown to mediate its apoptosis
suppressive effects via phosphorylation of Bad or caspase-9. However, incubation
with insulin did not lead to enhanced phosphorylation of Bad at Ser 136 or Ser
112. In contrast, insulin inhibited caspase-9 activity and prevented caspase-9
induced apoptosis. Mutation of the Akt site within caspase-9 significantly
reduced the apoptosis-suppressive effect of insulin. The present study
demonstrates an important role for insulin-mediated Akt activation in the
prevention of endothelial cell apoptosis, which may importantly contribute to
cell homeostasis and the integrity of the endothelium. In endothelial cells, Akt
seems to mediate its antiapoptotic effect, at least in part, via phosphorylation
of caspase-9 rather than Bad.
PMID- 10669637
TI - Expression of tumor necrosis factor-alpha in cultured human endothelial cells
stimulated with lipopolysaccharide or interleukin-1alpha.
AB - Tumor-necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine with a wide
variety of biological effects. The most important source of this cytokine is
monocytes/macrophages. It is a potent agonist in the activation of endothelial
cells; however, the precise role of endothelial cells as a source of TNF-alpha is
not known. In the present study, we addressed the possibility that TNF-alpha is
produced by cultured human umbilical vein endothelial cells (HUVEC) stimulated
with factors such as lipopolysaccharide (LPS) or interleukin-1alpha (IL-1alpha).
LPS and IL-1alpha induced expression of TNF-alpha mRNA in HUVEC. IL-1alpha
induced expression and secretion of TNF-alpha protein, but LPS did not induce
production of TNF-alpha protein. Most of the TNF-alpha protein in cell lysate was
found in the membrane fraction. The mRNA for TNF-alpha-converting enzyme (TACE)
was expressed in unstimulated HUVEC, and its level was not altered by treatment
with LPS or IL-1alpha. Transfection of HUVEC with full-length cDNA encoding the
precursor TNF-alpha enhanced secretion of TNF-alpha protein by these cells, and
treatment of the cells with a TACE inhibitor reduced the secretion. These results
suggest that HUVEC produce TNF-alpha and have TACE activity. Secreted TNF-alpha
may be involved in autocrine activation of endothelial cells, and TNF-alpha
retained in cell membrane may serve as a juxtacrine system to activate target
cells on the endothelial surface.
PMID- 10669638
TI - Fluid flow releases fibroblast growth factor-2 from human aortic smooth muscle
cells.
AB - This study tested the hypothesis that fluid shear stress regulates the release of
fibroblast growth factor (FGF)-2 from human aortic smooth muscle cells. FGF-2 is
a potent mitogen that is involved in the response to vascular injury and is
expressed in a wide variety of cell types. FGF-2 is found in the cytoplasm of
cells and outside cells, where it associates with extracellular proteoglycans. To
test the hypothesis that shear stress regulates FGF-2 release, cells were exposed
to flow, and FGF-2 amounts were measured from the conditioned medium,
pericellular fraction (extracted by heparin treatment), and cell lysate. Results
from the present study show that after 15 minutes of shear stress at 25
dyne/cm(2) in a parallel-plate flow system, a small but significant fraction
(17%) of the total FGF-2 was released from human aortic smooth muscle cells. FGF
2 levels in the circulating medium increased 10-fold over medium from static
controls (P<0.01). A 50% increase in FGF-2 content versus control (P<0.01) was
found in the pericellular fraction (extracted by heparin treatment). Furthermore,
a significant decrease in FGF-2 was detected in the cell lysate, indicating that
FGF-2 was released from inside the cell. Cell permeability studies with
fluorescent dextran were performed to examine whether transient membrane
disruption caused FGF-2 release. Flow cytometry detected a 50% increase in mean
fluorescence of cells exposed to 25 dyne/cm(2) versus control cells. This
indicates that the observed FGF-2 release from human aortic smooth muscle cells
is likely due to transient membrane disruption on initiation of flow.
PMID- 10669639
TI - Homocysteine-induced inhibition of endothelium-dependent relaxation in rabbit
aorta: role for superoxide anions.
AB - Hyperhomocysteinemia is associated with endothelial dysfunction, although its
mechanism is unknown. Isometric tension recordings and lucigenin
chemiluminescence were used to assess the effects of homocysteine exposure on
endothelium-dependent and -independent relaxation in isolated rabbit aortic rings
and superoxide anion (O(2)(-)) production by cultured porcine aortic endothelial
cells, respectively. Homocysteine (0.1 to 10 mmol/L) produced a significant
(P<0.001) concentration- and time-dependent inhibition of endothelium-dependent
relaxation in response to both acetylcholine and the calcium ionophore A23187.
Only the intracellular O(2)(-) scavenger 4,5-dihydroxy-1,3-benzene disulfonic
acid (Tiron, 10 mmol/L) significantly (P<0.001) inhibited the effect of
homocysteine on acetylcholine- and A23187-induced relaxation. Incubation of
porcine aortic endothelial cells with homocysteine (0.03 to 1 mmol/L for up to 72
hours) caused a significant (P<0.001) time-dependent increase in the O(2)(-)
released by these cells on the addition of Triton X-100 (1% [vol/vol]), with
levels returning to values comparable to those of control cells at the 72-hour
time point. These changes in O(2)(-) levels were associated with a time-dependent
increase in endothelial cell superoxide dismutase activity, becoming significant
(P<0.001) after 72 hours. Furthermore, the homocysteine-induced increase in
endothelial cell O(2)(-) levels was completely inhibited (P<0.001) by the
concomitant incubation with either Tiron (10 mmol/L), vitamin C (10 micromol/L),
or vitamin E (10 micromol/L). These data suggest that the inhibitory effect of
homocysteine on endothelium-dependent relaxation is due to an increase in the
endothelial cell intracellular levels of O(2)(-) and provide a possible mechanism
for the endothelial dysfunction associated with hyperhomocysteinemia.
PMID- 10669640
TI - In vivo evidence of the importance of cardiac angiotensin-converting enzyme in
the pathogenesis of cardiac hypertrophy.
AB - Cardiac angiotensin-converting enzyme (ACE) may play an important role in
regulating cardiac hypertrophy. Angiotensin II (Ang II) stimulates cardiac
hypertrophy as well as the production of extracellular matrix. However, it is
still unclear whether Ang II exerts a direct effect on cardiac hypertrophy
independent of its effect on blood pressure or the circulating renin-angiotensin
system. Although ACE inhibitors and/or Ang II receptor antagonists have regressed
cardiac hypertrophy, classic pharmacological experiments cannot exclude the
contribution of hemodynamics and the circulating renin-angiotensin system. In
vivo gene transfer provides the opportunity of assessing the effects of increased
cardiac angiotensin in the intact animal without circulating angiotensin or blood
pressure. Therefore, we used a "gain of function" approach to obtain local
overexpression of cardiac ACE. Transfection of the human ACE vector into rat
myocardium resulted in a significant increase in cardiac ACE activity (P<0.01).
More interestingly, morphometry at 2 weeks after transfection revealed a
significant increase in the thickness and areas of cardiac myocytes in hearts
transfected with the ACE vector (P<0.01). In addition, transfection of the ACE
vector also resulted in a significant increase in collagen content (P<0.01). This
increase in cardiac hypertrophy was abolished by the administration of
perindopril. Local transfection of the ACE vector into the heart did not result
in systemic effects such as increased blood pressure, heart rate, or serum ACE
activity. In summary, we have demonstrated that increased autocrine/paracrine
angiotensin can directly cause cardiac hypertrophy independent of systemic
factors and hemodynamic effects. This approach has important potentials for
defining the role of autocrine/paracrine substances in cardiovascular disease.
PMID- 10669641
TI - Complete atherosclerosis regression after human ApoE gene transfer in ApoE
deficient/nude mice.
AB - The apolipoprotein E (apoE)-deficient mouse is a relevant animal model of human
atherosclerosis. Although the prevention of atherosclerosis development has been
documented after somatic gene transfer into animal models, regression of lesions
remains to be demonstrated. Thus, we used this genetically defined mouse model nn
the nude background to show atherosclerosis regression. ApoE-deficient nude mice
were infected with 5 x 10(8) or 10(9) plaque-forming units of a first-generation
adenovirus encoding human apoE cDNA. The secretion of human apoE resulted in a
rapid decrease of total cholesterol, which normalized the hypercholesterolemic
phenotype within 14 days (from 600+/-100 to <100 microg/mL). Transgene expression
was observed during a period of >4 months, with a normalization of cholesterol
and triglyceride levels during 5 months. At that time, we successfully reinjected
the recombinant adenovirus and observed the appearance of the human protein as
well as the correction of lipoprotein phenotype. In mice killed 6 months-after
the first infection, we observed a dose-dependent regression of fatty streak
lesions in the aorta. We showed sustained expression of a transgene with a first
generation adenoviral vector and a correction of dyslipoproteinemia phenotype
leading to lesion regression. These data demonstrate that somatic gene transfer
can induce plaque regression.
PMID- 10669642
TI - Leptin, peroxisome proliferator-activated receptor-gamma, and CCAAT/enhancer
binding protein-alpha mRNA expression in adipose tissue of humans and their
relation to cardiovascular risk factors.
AB - Obesity is a prevalent disorder that increases the risk for premature
cardiovascular disease. The adipose tissue itself plays an active role in the
regulation of fuel metabolism and energy homeostasis by expressing a number of
regulatory genes, such as leptin, peroxisome proliferator-activated receptor
gamma (PPARgamma), and CCAAT/enhancer binding protein-alpha (C/EBPalpha). To
study the in vivo relationships among these genes and their associations with
cardiovascular risk factors, plasma levels of leptin, lipids, apolipoproteins
(apo), insulin, and glucose were measured in 216 obese, 165 nonobese, and 36
weight-losing postobese subjects. mRNA expression of leptin, PPARgamma, and
C/EBPalpha in the extraperitoneal and intraperitoneal adipose tissue was
quantified in subsets of subjects. In obese individuals, plasma leptin was
associated with apoA-I (r=0.2346, P<0.001) and insulin (r=0.2125, P<0.002).
Leptin and C/EBPalpha mRNA expression in extraperitoneal and intraperitoneal
adipose tissue of obese patients was higher than in the respective tissues of
nonobese or postobese subjects. No significant differences among the study groups
were found for PPARgamma mRNA expression. Leptin, PPARgamma, and C/EBPalpha mRNA
levels correlated with each other in the intraperitoneal and extraperitoneal fat
of obese subjects, but multivariate analysis revealed that only C/EBPalpha was a
predictor of leptin expression in extraperitoneal tissue (partial r=0.6096,
P<0.001). Intraperitoneal PPARgamma expression was inversely related to fasting
insulin (r=-0.2888, P<0.017) and a fasting insulin resistance index (r=-0.2814,
P<0.021) in obese subjects. In postobese patients, intraperitoneal PPARgamma
expression was associated with plasma HDL cholesterol (r=0.5695, P<0.018) and
apoA-I (r=0.6216, P<0.008) but was inversely related to LDL cholesterol (r=
0.5101, P<0.03) and apoB (r=-0.6331, P<0.007). These findings suggest a
relationship between plasma leptin and HDL metabolism as well as adipose-tissue
site-dependent associations among leptin, C/EBP-alpha, and PPAR-gamma mRNA
expression. Furthermore, our results suggest that C/EBP-alpha enhances leptin
expression in vivo and that PPARgamma mRNA expression is inversely associated
with cardiovascular risk factors.
PMID- 10669643
TI - LCAT modulates atherogenic plasma lipoproteins and the extent of atherosclerosis
only in the presence of normal LDL receptors in transgenic rabbits.
AB - Elevated low density lipoprotein cholesterol (LDL-C) and reduced high density
lipoprotein cholesterol (HDL-C) concentrations are independent risk factors for
coronary heart disease. We have previously demonstrated that overexpression of an
enzyme with a well established role in HDL metabolism, lecithin:cholesterol
acyltransferase (LCAT), in New Zealand White rabbits not only raises HDL-C
concentrations but reduces those of LDL-C as well, ultimately preventing diet
induced atherosclerosis. In the present study, the human LCAT gene (hLCAT) was
introduced into LDL receptor (LDLr)-deficient (Watanabe heritable hyperlipidemic)
rabbits to (1) investigate the role of the LDLr pathway in the hLCAT-mediated
reductions of LDL-C and (2) determine the influence of hLCAT overexpression on
atherosclerosis susceptibility in an animal model of familial
hypercholesterolemia. Heterozygosity or homozygosity for the LDLr defect was
determined by polymerase chain reaction, and 3 groups of hLCAT-transgenic
(hLCAT+) rabbits that differed in LDLr status were established: (1) LDLr wild
type (LDLr+/+), (2) LDLr heterozygotes (LDLr+/-), and (3) LDLr homozygotes (LDLr
/-). Data for hLCAT+ rabbits were compared with those of nontransgenic (hLCAT-)
rabbits of the same LDLr status. Plasma HDL-C concentrations were significantly
elevated in the hLCAT+ animals of each LDLr status. However, LDL-C levels were
significantly reduced only in hLCAT+/LDLr+/+ and hLCAT+/LDLr+/- rabbits but not
in hLCAT+/LDLr-/- rabbits (405+/-14 versus 392+/-31 mg/dL). Metabolic studies
revealed that the fractional catabolic rate (FCR, d(-1)) of LDL apolipoprotein
(apo) B-100 was increased in hLCAT+/LDLr+/+ (26+/-4 versus 5+/-0) and
hLCAT+/LDLr+/- (4+/-1 versus 1+/-0) rabbits, whereas the FCR of LDL apoB-100 in
both groups of LDLr-/- rabbits was nearly identical (0.16+/-0.02 versus 0.15+/
0.02). Consistently, neither aortic lipid concentrations nor the extent of aortic
atherosclerosis was significantly different between hLCAT+/LDLr-/- and hLCAT
/LDLr-/- rabbits. Significant correlations were observed between the percent of
aortic atherosclerosis and both LDL-C (r=0.985) and LDL apoB-100 FCR (-0.745), as
well as between LDL-C and LDL apoB-100 FCR (-0.866). These data are the first to
establish that LCAT modulates LDL metabolism via the LDLr pathway, ultimately
influencing atherosclerosis susceptibility. Moreover, LCAT's antiatherogenic
effect requires only a single functional LDLr allele, identifying LCAT as an
attractive gene therapy candidate for the majority of dyslipoproteinemic
patients.
PMID- 10669644
TI - The Arg123-Tyr166 central domain of human ApoAI is critical for
lecithin:cholesterol acyltransferase-induced hyperalphalipoproteinemia and HDL
remodeling in transgenic mice.
AB - High density lipoprotein (HDL) metabolism and lecithin:cholesterol
acyltransferase (LCAT)-induced HDL remodeling were investigated in transgenic
mice expressing human apolipoprotein (apo) AI or an apoAI/apoAII chimera in which
the Arg123-Tyr166 domain of apoAI was substituted with the Ser12-Ala75 domain of
apoAII. Expression of apoAI and of the apoAI/apoAII chimera resulted in a
respective 3. 5-fold and 2.9-fold increase of HDL cholesterol. Human LCAT gene
transfer into apoAI-transgenic mice resulted in a 5.1-fold increase of endogenous
LCAT activity. This increase was associated with a 2. 4-fold increase of the
cholesterol ester-to-free cholesterol ratio of HDL, a shift from HDL(3) to
HDL(2), and a 2.4-fold increase of HDL cholesterol levels. Agarose gel
electrophoresis revealed that human LCAT gene transfer into human apoAI
transgenic mice resulted in an increase of pre-beta-HDL and of pre-alpha-HDL. In
contrast, human LCAT gene transfer did not affect cholesterol levels and HDL
distribution profile in mice expressing the apoAI/apoAII chimera. Mouse LCAT did
not "see" a difference between wild-type and mutant human apoAI, whereas human
LCAT did, thus localizing the species-specific interaction in the central domain
of apoAI. In conclusion, the Arg123-Tyr166 central domain of apoAI is not
critical for in vivo lipoprotein association. It is, however, critical for LCAT
induced hyperalphalipoproteinemia and HDL remodeling independent of the lipid
binding properties of apoAI.
PMID- 10669645
TI - Glucosylated glycerophosphoethanolamines are the major LDL glycation products and
increase LDL susceptibility to oxidation: evidence of their presence in
atherosclerotic lesions.
AB - Glycation of both protein and lipid components is believed to be involved in LDL
oxidation. However, the relative importance of lipid and protein glycation in the
oxidation process has not been established, and products of lipid glycation have
not been isolated. Using glucosylated phosphatidylethanolamine (Glc PtdEtn)
prepared synthetically, we have identified glycated diacyl and alkenylacyl
species among the ethanolamine phospholipids in LDL. Accumulation of these
glycation products in LDL incubated with glucose showed a time- and glucose
concentration-dependent increase. LDL specifically enriched with Glc PtdEtn (25
nmol/mg protein) showed increased susceptibility to lipid oxidation when dialyzed
against a 5-micromol/L Cu(2+) solution. The presence of this glucosylated lipid
resulted in a 5-fold increase in production of phospholipid-bound hydroperoxides
and 4-fold increase in phospholipid-bound aldehydes. Inclusion of glucosylated
phosphatidylethanolamine in the surface lipid monolayer of the LDL resulted in
rapid loss of polyunsaturated cholesteryl esters from the interior of the
particle during oxidation. Glycated ethanolamine phospholipids were also isolated
and identified from atherosclerotic plaques collected from both diabetic and
nondiabetic subjects. The present findings provide direct evidence for the
previously proposed causative effect of lipid glycation on LDL oxidation.
PMID- 10669646
TI - Intravascular ultrasound combined with Raman spectroscopy to localize and
quantify cholesterol and calcium salts in atherosclerotic coronary arteries.
AB - Coronary intravascular ultrasound (IVUS) can assess arterial wall architecture
and localize large intravascular deposits, but it does not provide quantitative
chemical information, which is essential in the evaluation of atherosclerotic
lesions. Previously, it has been shown that Raman spectroscopy can be used to
accurately quantify the relative weights of cholesterol, calcium salts,
triglycerides, and phospholipids in homogenized arterial tissue. In the present
study, we explore some benefits of combining IVUS and Raman spectroscopy to
evaluate the intact arterial wall. IVUS images were collected in vitro from human
coronary arterial segments in various stages of disease (n=7). The images were
divided into radial segments (11 to 28 per image, 332 in total), each of which
was classified visually as calcified or noncalcified tissue. The arteries were
opened longitudinally, and Raman spectra were collected from locations at 0. 5-mm
intervals across the arterial luminal circumference. The spectra were used to
calculate the chemical composition of the arterial wall at the examined
locations. Generally, locations containing large amounts of calcium salts, as
determined with Raman spectroscopy, were classified as calcified with IVUS.
However, small calcific deposits (<6% of weight) were not readily detected with
IVUS. The amounts and location of cholesterol determined with Raman spectroscopy
were correlated closely with the presence of cholesterol observed by
histochemistry, but these deposits could not be located accurately by IVUS. The
combination of Raman spectroscopy and IVUS applied in vitro provides detailed
information about the amount and location of calcific deposits and lipid pools in
atherosclerotic plaques. Future advances in optical fiber technology may allow
simultaneous collection of Raman spectra and IVUS images through the same
catheter in vivo.
PMID- 10669647
TI - ACE gene polymorphism in cardiovascular disease: meta-analyses of small and large
studies in whites.
AB - The objective of this study was to assess the influence of the ACE gene insertion
(I)/deletion (D) polymorphism on plasma ACE activity; blood pressure; and risk of
myocardial infarction, ischemic heart disease, and ischemic cerebrovascular
disease by comparing small and large studies. The meta-analyses are based on a
literature search of MEDLINE up until April 1998 and assessment of bibliographies
of published studies and reviews. Forty-six studies were selected, including a
total of 32 715 white individuals. Plasma ACE activity was increased 40% and 71%
for ID and DD versus II in small studies and 21% and 48% in large studies (small
versus large: P<0.001 and P<0.001). Blood pressure was not influenced by
genotype. Risk of myocardial infarction and ischemic heart disease was increased
by 47% and 29%, respectively, for DD versus ID and II genotypes in small studies
but not in large studies (small versus large: P<0.001 for risk of myocardial
infarction and P=0.01 for risk of ischemic heart disease). Risk of ischemic
cerebrovascular disease was not increased either in the small or in the largest
study. In conclusion, the ACE gene polymorphism affects plasma ACE activity but
not blood pressure and is not associated with increased risk of myocardial
infarction, ischemic heart disease, or ischemic cerebrovascular disease in the
largest studies.
PMID- 10669648
TI - Homocysteine and lipoprotein(a) interact to increase CAD risk in young men and
women.
AB - A biochemical link between homocysteine (tHcy) and lipoprotein(a) [Lp(a)] related
to fibrin binding has been proposed. This hypothesis has not been specifically
examined in human subjects. We sought to determine in a clinical setting whether
these risk factors would interact to increase coronary artery disease (CAD) risk.
We performed a cross-sectional analysis of 750 men and 403 women referred to a
preventive cardiology clinic at the Cleveland Clinic Foundation, in whom baseline
tHcy and Lp(a) data were available. Logistic regression after adjusting for
standard cardiovascular risk factors was used to estimate the relative risk of
CAD in patients with an Lp(a) >/=30 mg/dL and a tHcy >/=17 micromol/L. Neither
isolated high tHcy (odds ratio [OR]=1.06, P=0.89) nor isolated high Lp(a)
(OR=1.15, P=0.60) appeared to be associated with CAD in women. However, strong
evidence of an association was seen when both risk factors were present (OR=4.83,
P=0.003). Moreover, this increased risk showed evidence of an interactive effect
beyond that attributable to either additive or multiplicative effects of tHcy and
Lp(a) (P=0.03). In contrast, both elevated tHcy (OR=1.93, P=0. 05) and elevated
Lp(a) (OR=1.87, P=0.01) showed evidence of being independent risk factors for CAD
in men. The presence of both risk factors in men did not appear to confer
additional risk (OR=2.00, P=0.09), even though ORs as high as 12.4 were observed
within specific age intervals. Consistent with prior studies, tHcy and Lp(a) are
risk factors, either independently or in concert, for CAD in this clinical
population. More significantly, we found evidence that when both risk factors
were present in women, the associated risk was greater than what would be
expected if the 2 risks were simply acting independently. The absence of such an
interactive effect in men may be due to the confounding effects of age manifested
as "survivor bias." These clinical findings provide insights into the potential
roles of both tHcy and Lp(a) in the pathogenesis of atherosclerosis.
PMID- 10669649
TI - Stanol ester margarine alone and with simvastatin lowers serum cholesterol in
families with familial hypercholesterolemia caused by the FH-North Karelia
mutation.
AB - In heterozygous familial hypercholesterolemia (FH), serum low density lipoprotein
(LDL) cholesterol levels are already elevated at birth. Premature coronary heart
disease occurs in approximately 30% of heterozygous untreated adult patients.
Accordingly, to retard development of atherosclerosis, preventive measures for
lowering cholesterol should be started even in childhood. To this end, 19 FH
families consumed dietary stanol ester for 3 months. Stanol ester margarine
lowers the serum cholesterol level by inhibiting cholesterol absorption. Each
individual in the study replaced part of his or her daily dietary fat with 25 g
of 80% rapeseed oil margarine containing stanol esters (2.24 g/d stanols, mainly
sitostanol). The families who consumed this margarine for 12 weeks included 24
children, aged 3 to 13 years, with the North Karelia variant of FH (FH-NK), 4 FH
NK parents, and 16 healthy family members, and a separate group of 12 FH-NK
adults who consumed the margarine for 6 weeks and who were on simvastatin therapy
(20 or 40 mg/d). Fat-soluble vitamins were measured by high-pressure liquid
chromatography, and cholesterol precursor sterols (indexes of cholesterol
synthesis) and cholestanol and plant sterols (indexes of cholesterol absorption
efficiency) were assayed by gas-liquid chromatography. No side effects occurred.
Serum LDL cholesterol levels were reduced by 18% (P<0.001), 11%, 12% (P<0.001),
and 20% (P<0.001) in the 4 groups, respectively. The serum campesterol-to
cholesterol ratios fell by 31% (P<0.001), 29%, 23% (P<0.001), and 36% (P<0.001),
respectively, suggesting that cholesterol absorption efficiency was inhibited.
Serum lathosterol ratios were elevated by 38% (P<0.001), 11%, 15% (P<0.001), and
19% (P<0.001), respectively, suggesting that cholesterol synthesis was
compensatorily upregulated. The FH-NK children increased their serum lathosterol
ratio more than did the FH-NK adults treated with stanol ester margarine and
simvastatin (P<0.01). In the FH-NK children, serum retinol concentration and
alpha-tocopherol-to-cholesterol ratios were unchanged by stanol ester margarine,
but alpha- and beta-carotene concentrations and ratios were decreased. As assayed
in a genetically defined population of FH patients, a dietary regimen with stanol
ester margarine proved to be a safe and effective hypolipidemic treatment for
children and adults. In FH-NK adults on simvastatin therapy, serum LDL
cholesterol levels could be reduced even further by including a stanol ester
margarine in the regimen.
PMID- 10669650
TI - New functional promoter polymorphism, CETP/-629, in cholesteryl ester transfer
protein (CETP) gene related to CETP mass and high density lipoprotein cholesterol
levels: role of Sp1/Sp3 in transcriptional regulation.
AB - A new polymorphism located at position -629 (CETP/-629A/C) in the promoter of the
cholesteryl ester transfer protein (CETP) gene is described. The -629A allele was
associated with lower CETP mass (P<0. 0001) and higher high density lipoprotein
cholesterol (P<0.001) than the C allele in a sample of 536 control subjects from
the ECTIM study. Transfection studies in HepG2 cells with a luciferase expression
vector incorporating a 777-bp fragment of the CETP promoter and containing either
A or C at position -629 showed significantly lower luciferase activity with the
promoter fragment of the A allele (-25%, P<0.05). By gel-shift assay, DNA-protein
interactions were evaluated in nuclear extracts of HepG2 cells with the use of 2
probes (A or C probe) composed of 20 bp of the promoter sequence surrounding the
polymorphic site. Two specific complexes of distinct migration rate were
identified with the A and the C probe. Competition with an excess of
oligonucleotide containing the Sp1 consensus binding site showed that a
protein(s) of the Sp transcription factor family was implicated in complex
formation with the A probe but not with the C probe. Incubation with specific
antibodies indicated that Sp1 and Sp3 bound specifically to the A probe. We
introduced mutations in the -629-Sp1 binding site to test its functionality and
to define the characteristics of transcription factor binding. We showed, by gel
shift assay, that no nuclear proteins bound to the mutated sequence. Transient
transfection of HepG2 cells revealed that the expression of the mutated fragment
was significantly increased compared with that of the A promoter fragment (25%,
P<0.05). The mutated fragment displayed the same activity as that of the C
promoter. These results indicate that Sp1 and/or Sp3 repress CETP promoter
activity, whereas nuclear factors binding the C allele are without effect on
promoter expression.
PMID- 10669651
TI - Promoter polymorphisms of human paraoxonase PON1 gene and serum paraoxonase
activities and concentrations.
AB - Paraoxonase (PON) is a serum enzyme with a wide species distribution. It protects
lipoproteins from toxic oxidative modifications and is an antiatherogenic
mechanism of major potential. Activity levels of PON are major determinants of
the protective function; consequently, factors that influence PON levels are of
particular relevance. The present study has identified 3 polymorphisms in the
promoter region of the human PON1 gene. Cell transfection studies have revealed
their variable impact on promoter activity, with up to 2-fold differences in
reporter gene expression. Genotyping studies have established that the
polymorphisms are frequent in the population, a finding that is consistent with a
major impact on PON concentrations. The physiological relevance of the
polymorphisms was underlined by showing that they are associated with highly
significant differences in serum concentrations and activities of PON. The study
thus firmly establishes a genetic basis for variations in serum PON levels and,
consequently, serum PON activity. It is consistent with the suggestion that
variations in a major antioxidant function of high density lipoprotein are, to an
important degree, genetically determined.
PMID- 10669652
TI - Lipoprotein(a) in homozygous familial hypercholesterolemia.
AB - Lipoprotein(a) [Lp(a)] is a quantitative genetic trait that in the general
population is largely controlled by 1 major locus-the locus for the
apolipoprotein(a) [apo(a)] gene. Sibpair studies in families including familial
defective apolipoprotein B or familial hypercholesterolemia (FH) heterozygotes
have demonstrated that, in addition, mutations in apolipoprotein B and in the LDL
receptor (LDL-R) gene may affect Lp(a) plasma concentrations, but this issue is
controversial. Here, we have further investigated the influence of mutations in
the LDL-R gene on Lp(a) levels by inclusion of FH homozygotes. Sixty-nine members
of 22 families with FH were analyzed for mutations in the LDL-R as well as for
apo(a) genotypes, apo(a) isoforms, and Lp(a) plasma levels. Twenty-six
individuals were found to be homozygous for FH, and 43 were heterozygous for FH.
As in our previous analysis, FH heterozygotes had significantly higher Lp(a) than
did non-FH individuals from the same population. FH homozygotes with 2
nonfunctional LDL-R alleles had almost 2-fold higher Lp(a) levels than did FH
heterozygotes. This increase was not explained by differences in apo(a) allele
frequencies. Phenotyping of apo(a) and quantitative analysis of isoforms in
family members allowed the assignment of Lp(a) levels to both isoforms in apo(a)
heterozygous individuals. Thus, Lp(a) levels associated with apo(a) alleles that
were identical by descent could be compared. In the resulting 40 allele pairs,
significantly higher Lp(a) levels were detected in association with apo(a)
alleles from individuals with 2 defective LDL-R alleles compared with those with
only 1 defective allele. This difference of Lp(a) levels between allele pairs was
present across the whole size range of apo(a) alleles. Hence, mutations in the
LDL-R demonstrate a clear gene-dosage effect on Lp(a) plasma concentrations.
PMID- 10669653
TI - Distinct risk profiles of early and advanced atherosclerosis: prospective results
from the Bruneck Study.
AB - Most epidemiological surveys on risk factors of atherosclerosis were cross
sectional in design and did not consider the existence of pathologically distinct
processes. The Bruneck Study is a prospective survey in the general community
(age range, 40 to 79 years). The baseline examination and first reevaluation were
performed in the summers of 1990 and 1995 (participation, 92%; follow-up, 96%).
Carotid atherosclerosis was monitored with high-resolution duplex ultrasound.
Early (incidence and/or extension of nonstenotic lesions) and advanced (incidence
and/or progression of stenosis >40%) stages of atherogenesis were differentiated.
The risk profile of early atherogenesis consists of traditional risk factors,
such as hypertension, hyperlipidemia, and cigarette smoking (pack-years),
supplemented by a variety of less well-established risk conditions, including
high body iron stores, hypothyroidism, microalbuminuria, and high alcohol
consumption. In contrast, the risk profile of advanced atherogenesis includes
markers of enhanced prothrombotic capacity, attenuated fibrinolysis, and clinical
conditions known to interfere with coagulation: high fibrinogen, low
antithrombin, factor V Leiden mutation, lipoprotein(a) >0.32 g/L, high platelet
count, cigarette smoking, and diabetes. Hyperlipidemia and hypertension were of
only minor relevance. These findings, along with the epidemiological features of
advanced atherogenesis and emergence of an elevated fibrin turnover, suggest
atherothrombosis to be a key mechanism in the development of advanced stenotic
atherosclerosis. Supplementary 6-category logistic regression models illustrate
the changing association between major risk predictors and atherosclerosis of
increasing severity and substantiate appropriateness of the 40% threshold applied
for the definition of advanced stenotic atherosclerosis. Atherosclerosis is a
heterogeneous process that subsumes etiologically and epidemiologically distinct
disease entities. The multifactorial etiology of atherosclerosis, which goes far
beyond the traditional risk factors, has not yet achieved adequate attention in
clinical practice and disease prevention.
PMID- 10669654
TI - Insulin resistance syndrome predicts the risk of coronary heart disease and
stroke in healthy middle-aged men: the 22-year follow-up results of the Helsinki
Policemen Study.
AB - The interpretation of conventional multivariate analyses concerning the relation
of insulin to the risk of atherosclerotic disease is complex because of
correlations of insulin with other risk factors. Therefore, we applied factor
analysis to study the clustering of risk factors in the baseline data of the
Helsinki Policemen Study (970 healthy men aged 34 to 64 years) and investigated
whether these clusterings predict coronary heart disease (CHD) and stroke risk.
Areas under the glucose and insulin response curves (AUC glucose and AUC insulin)
were used to reflect glucose and insulin levels during oral glucose tolerance
tests. During the 22-year follow-up, 164 men had a CHD event, and 70 men had a
stroke. Factor analysis of 10 risk factor variables produced 3 underlying
factors: insulin resistance factor (comprising body mass index, subscapular
skinfold, AUC insulin, AUC glucose, maximal O(2) uptake, mean blood pressure, and
triglycerides), lipid factor (cholesterol and triglycerides), and lifestyle
factor (physical activity and smoking). In multivariate Cox models, the age
adjusted hazard ratio for insulin resistance factor during the 22-year follow-up
was 1.28 (95% CI 1.10 to 1.50) with regard to CHD risk and 1.64 (95% CI 1.29 to
2.08) with regard to stroke risk. Lipid factor predicted the risk of CHD but not
that of stroke, and lifestyle factor predicted a reduced CHD risk. Factor
analysis including only 6 risk factor variables proposed to be central components
of insulin resistance syndrome (body mass index, subscapular skinfold, AUC
insulin, AUC glucose, mean blood pressure, and triglycerides) produced only a
single insulin resistance factor that predicted the risk of CHD and stroke
independently of other risk factors.
PMID- 10669655
TI - Insulin therapy improves endothelial function in type 2 diabetes.
AB - A total of 75 in vivo endothelial function tests (intrabrachial artery infusions
of endothelium-dependent [acetylcholine] and -independent [sodium nitroprusside]
vasoactive agents) were performed in 18 type 2 diabetic patients (aged 58+/-2
years, body mass index 28.5+/-0.6 kg/m(2), and fasting plasma glucose 229+/-11
mg/dL) and 27 matched normal subjects. These tests were performed before and 6
months after combination therapy with insulin and metformin and before and 6
months after metformin therapy only. Before insulin therapy, blood flow responses
to acetylcholine (15 microg/min) were significantly blunted in type 2 diabetic
patients (7.5+/-0.7 mL x dL(-1) x min(-1)) compared with normal subjects (11.6+/
0.9 mL x dL(-1) x min(-1), P<0.01). During insulin therapy, the acetylcholine
response increased by 44% to 10.8+/-1.6 mL x dL(-1) x min(-1) (P<0.05). Insulin
therapy also significantly increased the blood flow responses to both low and
high doses of sodium nitroprusside. We conclude that insulin therapy improves
endothelium-dependent and -independent vasodilatation. These data support the
idea that insulin therapy has beneficial rather than harmful effects on vascular
function.
PMID- 10669656
TI - HMG CoA reductase inhibitors reduce plasminogen activator inhibitor-1 expression
by human vascular smooth muscle and endothelial cells.
AB - The clinical benefit of 3-hydroxy-3-methylglutaryl coenzyme A reductase
inhibitors (statins) may derive from a qualitative, functional change in
atherosclerotic lesions in addition to their lipid-lowering properties. We
examined whether statins altered expression of the major determinants of
fibrinolytic balance, plasminogen activator inhibitor-1 (PAI-1), and tissue-type
plasminogen activator (tPA) in human vascular smooth muscle (SMC) and endothelial
(EC) cells. Simvastatin reduced levels of PAI-1 antigen released from SMCs and
ECs stimulated with platelet-derived growth factor or transforming growth factor
beta (IC(50) approximately 1 micromol/L). Levels of EC-derived tPA increased 2
fold over the same concentrations of simvastatin that inhibited release of PAI-1.
Simvastatin's inhibitory effect was mimicked by C3 exoenzyme and prevented by
geranylgeranyl pyrophosphate, but not by farnesyl pyrophosphate, suggesting the
involvement of geranylgeranyl-modified intermediates. Decreased PAI-1 antigen was
correlated with reduced mRNA transcription and activity of the PAI-1 promoter. By
inhibiting expression of PAI-1 from SMCs and ECs while increasing expression of
tPA from ECs, simvastatin may alter the local fibrinolytic balance within the
vessel wall toward increased fibrinolytic capacity that, in turn, would reduce
thrombotic risk after plaque rupture.
PMID- 10669657
TI - Interaction of anti-phospholipid antibodies with late endosomes of human
endothelial cells.
AB - Anti-phospholipid antibodies (APLAs) are associated with thrombosis and/or
recurrent pregnancy loss. APLAs bind to anionic phospholipids directly or
indirectly via a cofactor such as beta(2)-glycoprotein 1 (beta(2)GPI). The lipid
target of APLA is not yet established. Recently, we observed that APLAs in vitro
can bind lysobisphosphatidic acid (LBPA). The internal membranes of late
endosomes are enriched in this phospholipid. The current study was undertaken to
determine to what extent binding of APLA to LBPA is correlated with binding to
cardiolipin and to beta(2)GPI and to determine whether patient antibodies
interact with late endosomes of human umbilical vein endothelial cells (HUVECs)
and thus modify the intracellular trafficking of proteins. Binding of patient
immunoglobulin G (n=37) to LBPA was correlated significantly with binding to
cardiolipin. Although LBPA binding was correlated to a lesser extent with
beta(2)GPI binding, we observed that beta(2)GPI binds with high affinity to LBPA.
Immunofluorescence studies showed that late endosomes of HUVECs contain LBPA.
Patient but not control antibodies recognized late endosomes, but not cardiolipin
rich mitochondria, even when we used antibodies that were immunopurified on
cardiolipin. Incubation of HUVECs with patient plasma samples immunoreactive
toward LBPA resulted in an accumulation of the antibodies in late endosomes and
led to a redistribution of the insulinlike growth factor 2/mannose-6-phosphate
receptor from the Golgi apparatus to late endosomes. Our results suggest that
LBPA is an important lipid target of APLA in HUVECs. These antibodies are
internalized by the cells and accumulate in late endosomes. By modifying the
intracellular trafficking of proteins, APLA could contribute to several of the
proposed pathogenic mechanisms leading to the antiphospholipid syndrome.
PMID- 10669658
TI - Effect of individual plasma lipoprotein(a) variations in vivo on its competition
with plasminogen for fibrin and cell binding: An in vitro study using plasma from
children with idiopathic nephrotic syndrome.
AB - Simultaneous natural changes in lipoprotein(a) [Lp(a)] and plasminogen occur in
the nephrotic syndrome and offer a unique opportunity to investigate their
effects on plasminogen activation under conditions fashioned in vivo.
Plasminogen, Lp(a), and apolipoprotein(a) in plasma were characterized, and their
competitive binding to carboxy-terminal lysine residues of fibrin and cell
membrane proteins was determined in nephrotic children during a flare-up of the
disease (61 cases) and after 6 weeks (33 cases) and 6 months (42 cases) of
remission. Low plasminogen concentrations (median 1.34 micromol/L, range 0.39 to
1.96 micromol/L) and high Lp(a) levels (median 0.27 g/L, range 0.07 to 2. 57 g/L)
were detected at flare-up. These changes were associated with an increased Lp(a)
binding ratio onto fibrin (3.13+/-0.48) and cells (1.53+/-0.24) compared with
binding ratios of control children (1.31+/-0.19 and 1.05+/-0.07, respectively)
with normal plasminogen and low Lp(a) (median 0.071 g/L). After 6 weeks and 6
months of remission, the values for net decrease in Lp(a) binding to fibrin were
1.7+/-0.22 (after 6 weeks) and 1.88+/-0.38 (after 6 months) and were correlated
with low Lp(a) concentrations (median 0.2 g/L, range 0.07 to 0.8 g/L; and median
0.12 g/L, range 0.07 to 1.34 g/L) and inversely associated with increased
plasminogen levels (median 1.82 micromol/L, range 1.4 to 2.1 micromol/L; and
median 1.58 micromol/L, range 1.1 to 2.1 micromol/L). These studies provide the
first quantitative evidence that binding of Lp(a) to lysine residues of fibrin
and cell surfaces is directly related to circulating levels of both plasminogen
and Lp(a) and that these glycoproteins may interact as competitive ligands for
these biological surfaces in vivo. This mechanism may be of relevance to the
atherothrombotic role of Lp(a), particularly in nephrotic patients.
PMID- 10669659
TI - Protective effect of a thrombin receptor (protease-activated receptor 1) gene
polymorphism toward venous thromboembolism.
AB - The human protease-activated receptor 1 (PAR-1) is activated by thrombin at the
surface of platelets and endothelial cells, 2 cells that are implicated in
hemostasis and thrombosis. We studied the PAR-1 gene in a large case-control
study from the Paris Thrombosis Study (PATHROS), and the possible implication of
polymorphisms in venous thromboembolism was evaluated. Two polymorphisms were
found in the 5' regulatory region. The first is a C to T transition that is 1426
nucleotides upstream from the translation start site (-1426 C/T), and the second
is a 13-bp insertion repeating the preceding -506 5'-CGGCCGCGGGAAG-3' sequence (
506 I/D, where I indicates insertion and D indicates deletion), a putative cis
acting element of the Ets family. The third polymorphism is an A to T
transversion in the intervening sequence (IVS) that is 14 nucleotides upstream
from the exon 2 start site (IVS-14 A/T). The distribution of the 3 polymorphisms
was otherwise similar in the 250 cases and the 1214 controls. A noteworthy sex
heterogeneity led us to analyze men and women separately with regard to the -506
I/D polymorphism. We found that allele I was less frequent in male cases than in
male controls (0.154 versus 0.247, P<0.01), with an odds ratio at 0.52 (95% CI 0.
32 to 0.82, P<0.01). Furthermore, a reduction of prothrombin fragment 1+2 levels
was observed in homozygous carriers of allele -506 I (P=0.04). Altogether, these
data suggested a protective effect in men of -506 I/D polymorphism for venous
thromboembolism.
PMID- 10669660
TI - Factor VII gene polymorphism, factor VII levels, and prevalent cardiovascular
disease: the Framingham Heart Study.
AB - Elevated factor VII levels have been associated with increased cardiovascular
risk in some studies. The arginine/glutamine (Arg/Gln) polymorphism of the factor
VII gene has been previously shown to modify factor VII levels. However, the
presence of a gene/environment interaction on factor VII levels or a link with
cardiovascular disease (CVD) remains uncertain. We studied subjects from the
Framingham Heart Study to determine (1) the extent to which this genetic
polymorphism affects factor VII levels; (2) whether interactions exist between
this polymorphism and environmental factors on factor VII levels; and (3) the
association between the polymorphism and CVD. Genotype data and factor VII
antigen levels were available in 1816 subjects. Factor VII levels differed
significantly among genotypes in an additive fashion: Gln homozygous, 82.7+/
2.5%; heterozygous, 92.2+/-0.7%; and Arg homozygous, 100. 5+/-0.4% (P<0.0001).
The polymorphism was the strongest, single predictor of factor VII levels,
explaining 7.7% of the total variance of factor VII levels, whereas other
traditional risk factors combined explained an additional 11.5% of the variance.
There was an interaction (P=0.02) between the genotype and total cholesterol on
factor VII levels, such that the correlation coefficient and slope (factor VII
level/total cholesterol) were greatest in Gln/Gln subjects. Among 3204 subjects
characterized for genotype and CVD, there was no significant relationship between
the genotype and CVD (P=0.12). In the Framingham Heart Study, the Arg/Gln
polymorphism was significantly associated with factor VII antigen levels. The
strength of the association suggests that genetic variation plays an important
role in determining factor VII levels. However, despite being associated with
factor VII levels, the Arg/Gln polymorphism was not associated with prevalent
CVD.
PMID- 10669661
TI - Determinants of population changes in fibrinogen and factor VII over 6 years: the
Atherosclerosis Risk in Communities (ARIC) Study.
AB - Although numerous cross-sectional studies have identified possible determinants
of plasma fibrinogen and factor VII levels, few prospective studies exist. We
assessed the longitudinal relation of changes in fibrinogen and factor VII over 6
years with changes to other cardiovascular risk factors in a sample of 440 men
and 549 women from the Atherosclerosis Risk in Communities (ARIC) study.
Fibrinogen increased more in older participants, those with or who developed
diabetes, those who at any time smoked, and those whose plasma HDL cholesterol or
triglycerides decreased and increased less in female participants who started
hormonal replacement therapy. Factor VII coagulant activity increased more in
younger participants, women, those who gained greater weight or developed
diabetes, those who quit smoking, those in whom plasma triglycerides decreased,
and female participants who received hormonal replacement therapy. Thus, our
longitudinal data suggest with some exceptions that adverse changes in
cardiovascular risk factors are accompanied by increases in plasma levels of
fibrinogen and factor VII.
PMID- 10669662
TI - Left atrial appendage myopathy: the importance of serial transesophageal
assessment in atrial fibrillation.
PMID- 10669663
TI - Transesophageal endoscopic ultrasound-guided mediastinal lymph node aspiration:
does the end justify the means?
PMID- 10669664
TI - Disorders of ventilation : weakness, stiffness, and mobilization.
PMID- 10669665
TI - Diagnosis and natural history of pulmonary infections in transplant recipients.
PMID- 10669666
TI - Epidural analgesia and cardiac surgery: worth the risk?
PMID- 10669667
TI - Unconventional cancer therapies : what We need is rigorous research, not closed
minds.
PMID- 10669668
TI - Association of follow-up change of left atrial appendage blood flow velocity with
spontaneous echo contrast in nonrheumatic atrial fibrillation.
AB - STUDY OBJECTIVES: To evaluate the time-related change of left atrial (LA)
appendage flow velocity in chronic atrial fibrillation (AF) by follow-up
transesophageal echocardiography (TEE) and to investigate its association with
the occurrence of LA spontaneous echo contrast. DESIGN: Prospective follow-up
study. SETTING: University-based, tertiary referral medical center. PATIENTS:
Forty-seven patients with chronic nonrheumatic AF. INTERVENTIONS: All studied
patients underwent both a baseline and follow-up TEE during a mean period of 13
+/- 7 months. MEASUREMENTS AND RESULTS: Baseline TEE revealed that LA spontaneous
echo contrast was present in 28 patients (group 1) and was absent in 19 patients
(group 2). The LA appendage flow velocity profiles at baseline were significantly
lower in group 1 than in group 2; on follow-up, the appendage flow velocities
decreased significantly in group 2, but were not significantly changed in group
1. Follow-up TEE revealed that spontaneous echo contrast was persistent in all
group 1 patients. In group 2, LA spontaneous echo contrast was newly observed in
9 patients (group 2A) but was persistently absent in 10 patients (group 2B). In
group 2A, all of the LA appendage flow velocity profiles decreased significantly
at the follow-up study. In group 2B, however, only LA appendage inflow velocity
integral showed significant decrease on follow-up; there were no significant
changes in LA appendage outflow velocity indexes and peak inflow velocity.
CONCLUSIONS: LA appendage flow velocity may decrease with time in some patients
with AF, and this change is associated with a new occurrence of LA spontaneous
echo contrast. For patients without LA spontaneous echo contrast, serial follow
up of the LA appendage flow velocity profiles may be useful for predicting future
development of spontaneous echo contrast. Once LA spontaneous echo contrast
occurs in AF patients, it tends to persist with time and the LA appendage is
usually under a persistently low flow state.
PMID- 10669669
TI - Left ventricular thrombus and subsequent thromboembolism in patients with severe
systolic dysfunction.
AB - STUDY OBJECTIVES: To determine the frequency of left ventricular (LV) thrombi by
echocardiography and to define the predictors of LV thrombus and subsequent
thromboembolism. DESIGN: Retrospective case-control design. SETTING: Single
tertiary care center. PATIENTS: Twenty-eight patients with LV thrombus in a
consecutive series of 144 patients with severe LV dysfunction and follow-up
period for a mean of 27.6 months. MEASUREMENTS AND RESULTS: Thirty-five clinical
and echocardiographic variables were evaluated. The mean age of patients with (n
= 28) vs patients without (n = 116) LV thrombus was 50.3 +/- 11.0 years vs 54.2
+/- 11.1 years (p = 0.09), with 22 patients (78.6%) and 78 patients (67.2%) being
male (p = 0.24), respectively. The mean ejection fraction (EF) for those with vs
those without LV thrombus was 17.5 +/- 5.5 vs 20.0 +/- 6.9 (p = 0. 08), with 16
patients (57.1%) and 42 patients (36.2%) having an EF < 20% (p = 0.04),
respectively. The groups were similar with respect to other baseline
characteristics, comorbid illnesses, and drug therapies other than
anticoagulants. All 28 patients with LV thrombus (100%) and 54 of those without
LV thrombus (46.6%) were treated with warfarin. Ischemic etiology of the
cardiomyopathy (odds ratio, 4.78; 95% confidence interval, 1.51 to 15.11; p =
0.008) and increased LV internal diastolic dimension (LVIDD; odds ratio, 1.10;
95% confidence interval, 1.03 to 1.18; p = 0.004) were found to be independent
predictors of thrombus formation. Peripheral embolism occurred in 5 patients
(17.9%) vs 13 patients (11.2%) of those with and without LV thrombi, respectively
(p = 0.35). Ischemic etiology of the cardiomyopathy (odds ratio, 3.79; 95%
confidence interval, 1. 13 to 12.64; p = 0.03) and EF (odds ratio, 0.91; 95%
confidence interval, 0.82 to 1.00; p = 0.04) were found to be independent
predictors of systemic embolization. The patients with an embolic event suffered
a significantly higher mortality (7 of 18 patients; 38.9%) during the follow-up
period when compared to those without an embolic event (13 of 126 patients;
10.3%; p < 0.0001). CONCLUSIONS: We conclude that ischemic cardiomyopathy and
dilated LV chamber sizes (LVIDD > 60 mm) are independently associated with LV
thrombi. A peripheral embolic event is related to poor long-term survival in this
patient group.
PMID- 10669670
TI - Ventilatory constraints during exercise in patients with chronic heart failure.
AB - We examined the degree of ventilatory constraint in patients with a history of
chronic heart failure (CHF; n = 11; mean +/- SE age, 62 +/- 4 years; cardiac
index [CI], 2.0 +/- 0.1; and ejection fraction [EF], 24 +/- 2%) and in control
subjects (CTLS; n = 8; age, 61 +/- 5 years; CI, 2.6 +/- 0.3) by plotting the
tidal flow-volume responses to graded exercise in relationship to the maximal
flow-volume envelope (MFVL). Inspiratory capacity (IC) maneuvers were performed
to follow changes in end-expiratory lung volume (EELV) during exercise, and the
degree of expiratory flow limitation was assessed as the percent of the tidal
volume (VT) that met or exceeded the expiratory boundary of the MFVL. CHF
patients had significantly (p < 0.05) reduced baseline pulmonary function (FVC,
76 +/- 4%; FEV(1), 78 +/- 4% predicted) relative to CTLS (FVC, 99 +/- 4%; FEV(1),
102 +/- 4% predicted). At peak exercise, oxygen consumption (VO(2)) and minute
ventilation (V(E)) were lower in CHF patients than in CTLS (VO(2), 17 +/- 2 vs 32
+/- 2 mL/kg/min; VE, 56 +/- 4 vs 82 +/- 6 L/min, respectively), whereas VE/carbon
dioxide output was higher (42 +/- 4 vs 29 +/- 5). In CTLS, EELV initially
decreased with light exercise, but increased as VE and expiratory flow limitation
increased. In contrast, the EELV in patients with CHF remained near residual
volume (RV) throughout exercise, despite increasing flow limitation. At peak
exercise, IC averaged 91 +/- 3% and 79 +/- 4% (p < 0.05) of the FVC in CHF
patients and CTLS, respectively, and flow limitation was present over > 45% of
the VT in CHF patients vs < 25% in CTLS (despite the higher VE in CTLS). The
least fit and most symptomatic CHF patients demonstrated the lowest EELV, the
greatest degree of flow limitation, and a limited response to increased inspired
carbon dioxide during exercise, all consistent with VE constraint. We conclude
that patients with CHF commonly breathe near RV during exertion and experience
expiratory flow limitation. This results in VE constraint and may contribute to
exertional intolerance.
PMID- 10669671
TI - Characteristics and prognosis of myocardial infarction in patients with normal
coronary arteries.
AB - STUDY OBJECTIVES: Myocardial infarction with angiographically normal coronary
arteries (MINC) is a life-threatening event with many open questions for
physicians and patients. There are little data concerning the prognosis for
patients with MINC. DESIGN: Retrospective follow-up study. SETTING: Tertiary
referral center. PATIENTS: Patients with MINC were investigated and compared to
age- and sex-matched control subjects with myocardial infarction due to coronary
artery disease (CAD). The patients were examined clinically using stress exercise
and hyperventilation tests. Migraine and Raynaud's symptoms were determined by
means of a standardized questionnaire. Serum lipoproteins; the seroprevalence of
cytomegalovirus, Helicobacter pylori, and Chlamydia pneumoniae infections; and
the most frequent causes of thrombophilia were assessed. MEASUREMENTS AND
RESULTS: From > 4,300 angiographies that were performed between 1989 and 1996, 21
patients with MINC were identified. The mean +/- SD patient age at the time of
myocardial infarction was 42 +/- 7.5 years. When compared to control subjects (n
= 21), patients with MINC had fewer risk factors for CAD. In contrast, MINC
patients had more frequent febrile reactions prior to myocardial infarction (six
patients vs zero patients; p < 0.05), and the migraine score was significantly
higher (7.1 +/- 6.3 vs 2.2 +/- 4.1; p < 0.01). The seroprevalence of antibodies
against cytomegalovirus, C pneumoniae, and H pylori tended to be higher in
patients with MINC and CAD as compared to matched healthy control subjects. Three
patients with MINC vs none with CAD had coagulopathy. During follow-up (53 +/- 37
months), no major cardiac event occurred in the MINC group; no patients with MINC
vs nine with CAD (p = 0.0001) underwent repeated angiography. CONCLUSION: High
migraine score and prior febrile infection together with a lower cardiovascular
risk profile are compatible with an inflammatory and a vasomotor component in the
pathophysiology of the acute coronary event in MINC patients. The prognosis for
these patients is excellent.
PMID- 10669672
TI - Role of transesophageal endosonography-guided fine-needle aspiration in the
diagnosis of lung cancer.
AB - STUDY OBJECTIVE: Bronchoscopic methods fail to diagnose lung cancer in up to 30%
of patients. We studied the role of transesophageal endosonography (EUS)-guided
fine-needle aspiration (FNA; EUS-FNA) in such patients. DESIGN: Prospective
study. The final diagnosis was confirmed by cytology, histology, or clinical
follow-up. SETTING: University hospital. PATIENTS: Thirty-five patients (30 male
and 5 female; mean age, 60.9 years; range, 34 to 88 years) with suspected lung
cancer in whom bronchoscopic methods failed. Patients with a known diagnosis,
recurrence of lung cancer, or mediastinal metastasis from an extrathoracic
primary were excluded. INTERVENTIONS: EUS and guided FNA of mediastinal lymph
nodes. RESULTS: The procedure was uneventful, and material was adequate in all.
The final diagnosis by EUS-FNA was malignancy in 25 patients (11 adenocarcinoma,
10 small cell, 3 squamous cell, and 1 lymphoma) and benign disease in 9 patients
(5 inflammatory, 2 sarcoidosis, and 2 anthracosis). Another patient with a benign
result had signet-ring cell carcinoma diagnosed on pleural fluid cytology
(probably false-negative in EUS-FNA). The sensitivity, specificity, accuracy, and
positive and negative predictive values were 96, 100, 97, 100, and 90%,
respectively. There were no complications. Reviewing the EUS morphology, the
nodes were predominantly located in levels 7 and 8 of American Thoracic Society
mediastinal lymph node mapping (subcarinal and paraesophageal region). In seven
patients, the punctured nodes were < 1 cm (four malignant and three benign),
which are difficult to sample by other methods. The malignant nodes had a
hypoechoic, homogenous echotexture. CONCLUSIONS: EUS-FNA is a safe, reliable, and
accurate method to establish the diagnosis of suspected lung cancer when
bronchoscopic methods fail, especially in the presence of small nodes.
PMID- 10669673
TI - Decision-tree sensitivity analysis for cost-effectiveness of chest 2-fluoro-2-D
[(18)F]fluorodeoxyglucose positron emission tomography in patients with pulmonary
nodules (non-small cell lung carcinoma) in Japan.
AB - CONTEXT: Recent studies have demonstrated the potential cost-effectiveness of
using 2-fluoro-2-D-[(18)F]fluorodeoxyglucose (FDG) positron emission tomography
(PET) in the management of non-small cell lung carcinoma (NSCLC), but because of
differences in health-care systems, those findings may not hold true in a
Japanese hospital. OBJECTIVE: To assess the cost-effectiveness of the chest CT
plus chest FDG-PET strategy in Japan. DESIGN: Decision-tree sensitivity analysis
based on the two competing strategies of chest CT-alone vs chest CT plus chest
FDG-PET. STUDY SELECTION: A simulation of 1,000 patients in whom NSCLC, stage
IIIB or less, was suspected was created using baselines of other relevant
variables in regard to sensitivity, specificity, mortality, life expectancy, and
cost from published data. METHODS: We surveyed the relevant literature for the
choice of variables. MAIN OUTCOME MEASURES: Expected marginal cost and expected
life expectancy gain for NSCLC patients. RESULTS: The chest CT plus chest FDG-PET
strategy yielded an expected life expectancy gain of 0.607 years (7.3 months) per
patient, compared with the alternative strategy of chest CT-alone. Using an FDG
PET examination cost of 1.0 x 10(5) yen (around $700 US) per study, the cost
increment was 2.18 x 10(5) yen/yr/patient. CONCLUSIONS: The chest CT plus chest
FDG-PET strategy in patients with NSCLC is unlikely to be cost-effective in
Japan. However, patient life expectancy gain would increase as a result of
improved staging of NSCLC. These preliminary results should be confirmed by
further studies for specific environments.
PMID- 10669674
TI - Non-small cell lung cancer in very young and very old patients.
AB - STUDY OBJECTIVE: A cancer registry was analyzed to determine if the
clinicopathologic characteristics, treatment modalities, and prognosis of non
small cell lung cancer (NSCLC) patients < 40 years of age at diagnosis differed
from patients > 80 years of age at diagnosis. DESIGN: Retrospective review of
patients with NSCLC diagnosed between 1987 and 1996. SETTING: General teaching
hospital in Taiwan. PATIENTS: There were 6,048 cases of NSCLC diagnosed during
this period. Among them, 127 patients were < 40 years old and 184 patients were >
80 years old. These patients were selected for our study. MEASUREMENTS: Data
regarding demographics, presentation symptoms, histology, tumor staging,
treatment modality, and survival were obtained from all patients. Pearson's
chi(2) test and the Kaplan-Meier method with a log-rank test were used for
statistical analysis. RESULTS: We found significantly more female patients (p <
0.001) and adenocarcinoma (p < 0.001) in the younger group, when compared with
the older patients. Cough was the most frequent presenting symptom in both age
groups, followed by dyspnea, chest pain, and hemoptysis. There was no statistical
difference in the severity of the disease in terms of staging between the two age
groups. Young patients received surgical intervention more frequently than the
aged (p = 0.025). The older patients received only supportive care more
frequently (p = 0.011) than the younger patients. Survival was better in young
patients, when compared with other patients or aged patients (p < 0.001).
CONCLUSIONS: The female sex and adenocarcinoma were predominant in young NSCLC
patients, when compared with the older patients. Young NSCLC patients tended to
receive more aggressive treatment and had better survival.
PMID- 10669675
TI - Final results of phase III trial in regionally advanced unresectable non-small
cell lung cancer: Radiation Therapy Oncology Group, Eastern Cooperative Oncology
Group, and Southwest Oncology Group.
AB - STUDY OBJECTIVES: The purpose of this phase III clinical trial was to test
whether chemotherapy followed by radiation therapy resulted in superior survival
to either hyperfractionated radiation or standard radiation in surgically
unresectable non-small cell lung cancer. DESIGN: Patients were prospectively
randomized to 2 months of cisplatin, vinblastine chemotherapy followed by 60 Gy
of radiation at 2.0 Gy per fraction or 1.2 Gy per fraction radiation delivered
twice daily to a total dose of 69.6 Gy, or 2.0 Gy per fraction of radiation once
daily to 60 Gy. Patients were enrolled from January 1989 through January 1992,
and followed for a potential minimum period of 5 years. SETTING: This trial was
an intergroup National Cancer Institute-funded trial within the Radiation Therapy
Oncology Group, the Eastern Cooperative Oncology Group, and the Southwest
Oncology Group. PATIENTS: Patients with surgically unresectable non-small cell
lung cancer, clinical stage II, IIIA, and IIIB, were required to have a Karnofsky
Performance Status of > or = 70 and a weight loss of < 5% for 3 months before
study entry. Four hundred ninety patients were registered on trial, of which 458
patients were eligible. CONCLUSION: Overall survival was statistically superior
for the patients receiving chemotherapy and radiation vs the other two arms of
the study. The twice-daily radiation therapy arm, although better, was not
statistically superior in survival for those patients receiving standard
radiation. Median survival for standard radiation was 11.4 months; for
chemotherapy and irradiation, 13.2 months; and for hyperfractionated irradiation,
12 months. The respective 5-year survivals were 5% for standard radiation
therapy, 8% for chemotherapy followed by radiation therapy, and 6% for
hyperfractionated irradiation.
PMID- 10669676
TI - Serum interleukin-10 levels as a prognostic factor in advanced non-small cell
lung cancer patients.
AB - STUDY OBJECTIVE: To investigate the prognostic significance of interleukin (IL)
10 serum levels in advanced non-small cell lung cancer (NSCLC) patients. DESIGN:
IL-10 serum levels were measured before chemotherapy, on completion of therapy,
and at follow-up by means of a commercially available enzyme-linked immunoassay.
The results were then analyzed in comparison with other prognostic variables, and
a model predicting overall survival (OS) and time to treatment failure (TTF) was
finally generated. SETTING: University hospital. PATIENTS: Sixty consecutive
patients with TNM stage III or IV NSCLC undergoing conventional platinum-based
regimens. RESULTS: Elevated levels of serum IL-10 were found in cancer patients
with respect to healthy control subjects (17.7 +/- 4.4 vs 9.2 +/- 1.5 pg/mL,
respectively; p < 0.05), with patients with metastatic disease showing
significantly higher levels than patients with undisseminated cancer (21.0 +/-
4.2 vs 14.3 +/- 1.2 pg/mL, respectively; p < 0.05). Following completion of
treatment, patients were classified as responders if they had achieved either one
of the following: complete response, partial response, or stable disease; and
nonresponders, in case of progressive disease. Retrospective analysis of basal IL
10 serum levels in these two subgroups showed a significant difference between
responders and nonresponders (15.2 +/- 2.2 vs 21.4 +/- 4.2 pg/mL, respectively; p
< 0.05). Moreover, a further significant increase in IL-10 serum levels was
observed in nonresponders at the end of therapy (21.4 +/- 4.2 vs 26.0 +/- 4.3
pg/mL, prechemotherapy and postchemotherapy, respectively; p < 0.05), whereas
values in responders were found to have significantly decreased (15.2 +/- 2.2 vs
14.8 +/- 2.2 pg/mL, prechemotherapy and postchemotherapy, respectively; p <
0.05). Using univariate and multivariate analyses, both OS and TTF were shown to
be affected by the mean pathologic levels of IL-10. Stepwise regression analysis
identified IL-10 serum level and stage as the prognostic factors related to OS,
and IL-10 serum level and performance status as the prognostic factors related to
TTF. CONCLUSIONS: In conclusion, this study shows that the measurement of
pretreatment IL-10 serum levels is of independent prognostic utility in patients
with NSCLC and may be useful for detection of disease progression.
PMID- 10669677
TI - Prognostic assessment of 2,361 patients who underwent pulmonary resection for non
small cell lung cancer, stage I, II, and IIIA.
AB - STUDY OBJECTIVES: Staging and classification in lung cancer are important for
both patient management and clinical research. Results of survival after
resection in patients with primary non-small cell lung cancer (NSCLC) are
analyzed in order to validate recent refinements of the staging system. DESIGN:
Retrospective study; period from 1970 to 1992; follow-up > or = 5 years.
PATIENTS: A total of 2,361 previously untreated patients who underwent resection
for stage I, II, or IIIA primary NSCLC. MEASUREMENTS: Survival was estimated from
the date of operation using the Kaplan-Meier survival analysis method. Deaths
within 30 days of operation were excluded. Survival comparisons of different
surgical-pathologic TNM classification (based on pathologic examination of
resected specimens) as well as further discriminative factors were analyzed by
log-rank test. RESULTS: Postoperative death occurred in 3.9% of patients. For
survival analyses, 2,263 patients were included. The overall 5-year survival was
937/2,263 (41.4%). Five-year survival in stage IA was 255/404 (63%); in stage IB,
367/797 (46%); in stage IIA, 43/83 (52%); in stage IIB, 210/642 (33%); and in
stage IIIA, 63/337 (19%). No significant difference in survival was demonstrated
between stages IB and IIA. Until 4 years after surgery, age at operation did not
influence survival; after 5 years, patients > 65 years old had a significantly
lower survival. CONCLUSION: The TNM staging system accurately reflects the
prognosis in primary NSCLC, but some stage definitions can be discussed. Despite
the fact that the staging system is built on clinical data, the present analysis,
which includes postsurgical data, confirms the similar survival of patients with
T2N0M0 and T1N1M0. These results also stress the use of two separate substages,
especially because these patients are offered surgery when possible.
PMID- 10669678
TI - Nosocomial tuberculosis prevention measures among two groups of US hospitals,
1992 to 1996.
AB - OBJECTIVE: To compare trends in nosocomial tuberculosis (TB) prevention measures
and health-care worker (HCW) tuberculin skin test (TST) conversion of hospitals
with HIV-related Pneumocystis carinii pneumonia (PCP) patients and other US
hospitals from 1992 through 1996. DESIGN AND SETTING: Surveys in 1992 and 1996 of
38 hospitals with PCP patients in four high-HIV-incidence cities and 136 other US
hospitals from the American Hospital Association membership list. PARTICIPANTS:
Twenty-seven hospitals with PCP patients and 103 other US hospitals. RESULTS: In
1992, 63% of PCP hospitals and other US hospitals had rooms meeting Centers for
Disease Control and Prevention (CDC) criteria (ie, negative air pressure, six or
more air exchanges per hour, and air directly vented to the outside) for acid
fast bacilli isolation; in 1996, almost 100% had such isolation rooms. Similarly,
in 1992, nonfitted surgical masks were used by HCWs at 60% of PCP hospitals and
68% at other US hospitals, while N95 respirators were used at 90% of PCP
hospitals and 83% of other US hospitals in 1996. There was a significant
decreasing trend in TST conversion rates among HCWs at both PCP and other US
hospitals; however, this trend varied among all hospitals. HCWs at PCP hospitals
had a higher risk of TST conversion than those at other US hospitals (relative
risk, 1.71; p < 0.0001). CONCLUSION: From 1992 through 1996, PCP and other US
hospitals have made similar improvements in their nosocomial TB prevention
measures and decreased their HCW TST conversion rate. These data show that most
hospitals are compliant with CDC TB guidelines even before the enactment of an
Occupational Safety and Health Administration TB standard.
PMID- 10669679
TI - Bronchoscopic assessment of the evolution of endobronchial tuberculosis.
AB - BACKGROUND: We previously classified forms of endobronchial tuberculosis (EBTB)
into seven subtypes by bronchoscopic finding: actively caseating, edematous
hyperemic, fibrostenotic, tumorous, granular, ulcerative, and nonspecific
bronchitic. STUDY OBJECTIVE: To evaluate the value of this classification in
predicting the therapeutic outcome of EBTB. DESIGN: A prospective study with
serial bronchoscopy performed from the diagnosis of EBTB to the completion of
antituberculosis chemotherapy. PARTICIPANTS: Eighty-one patients with biopsy
proven EBTB. INTERVENTIONS: Fiberoptic bronchoscopy was done every month until
there was no subsequent change in the endobronchial lesions, every 3 months
thereafter, and at the end of treatment. RESULTS: Twenty-two of the 34 cases of
actively caseating EBTB changed into the fibrostenotic type, and the other 12
healed without sequelae. Seven of the 11 cases of edematous-hyperemic EBTB
changed into the fibrostenotic type, and the other 4 healed. Nine of the 11 cases
of granular EBTB, 6 cases of nonspecific bronchitic EBTB, and 2 cases of
ulcerative EBTB resolved completely. However, the other two cases of granular
EBTB changed into the fibrostenotic type. Seven cases of fibrostenotic EBTB did
not improve despite antituberculosis chemotherapy. These various changes in
bronchoscopic findings occurred within 3 months of treatment. In 10 cases of
tumorous EBTB, 7 progressed to the fibrostenotic type. In addition, new lesions
appeared in two cases, and the size of the initial lesions increased in another
two cases, even at 6 months after treatment. CONCLUSIONS: The therapeutic outcome
of each subtype of EBTB can be predicted by follow-up bronchoscopy during the
initial 3 months of treatment, with the exception of the tumorous type. In
tumorous EBTB, close and long-term follow-up is advisable because the evolution
of the lesions during treatment is very complicated and bronchial stenosis may
develop at a later time.
PMID- 10669680
TI - Frequency of subspecialty physician care for elderly patients with community
acquired pneumonia.
AB - STUDY OBJECTIVES: Specialty societies have developed practice guidelines for the
treatment of community-acquired pneumonia (CAP). To aid in adapting specialty
recommendations for a pneumonia practice guideline at Intermountain Health Care,
we investigated which physicians care for pneumonia patients in Utah. We wanted
to understand who provides pneumonia care so as to appropriately target the
guideline and design tools for implementation. DESIGN: Retrospective
observational study. SETTING: Inpatient and outpatient multicenter. PATIENTS: The
study population comprised 13,919 (16,420 episodes of pneumonia) Utah resident
Medicare beneficiaries > or = 65 years of age who had CAP. Nursing home residents
were excluded. MEASUREMENTS: We used Health Care Financing Administration billing
records from 1993 through 1995 to identify the physicians involved in the care of
pneumonia patients by self-designated specialty. We linked patterns of physician
involvement to age, sex, residential zip code, 30-day mortality rate, and whether
or not the patient was hospitalized. RESULTS: The involvement of a pneumonia
specialist was limited to 11.7% of episodes, with involvement of a pulmonary
specialist in 10.6%, an infectious disease (ID) specialist in 0.9%, and the
involvement of both specialties in 0.2% of episodes. Greater specialty
involvement was observed in episodes resulting in pneumonia hospitalization
(20.0% vs 8.6%, respectively; p < 0.0001), death (20.5% vs 11.2%, respectively; p
< 0.0001), and episodes among patients with urban county residential zip codes
(13.7% vs 7.5%, respectively; p < 0.0001). CONCLUSION: Most episodes of
pneumonia, including those with serious consequences, are treated by primary care
physicians with little or no involvement from pulmonary or ID specialists. It is
not known whether greater or lesser specialty physician involvement would change
pneumonia costs or clinical outcomes.
PMID- 10669681
TI - The radiologic manifestations of Legionnaire's disease. The Ohio Community-Based
Pneumonia Incidence Study Group.
AB - STUDY OBJECTIVES: To study the serial radiographic manifestations of
Legionnaire's disease from the initial presentation on admission to recovery
using strict criteria for the diagnosis of infection. MATERIALS AND METHODS: We
prospectively studied the chest radiographs of patients hospitalized with a
diagnosis of community-acquired pneumonia in Summit County, Ohio between November
1990 and November 1992. Forty-three patients fulfilled strict criteria for
legionellosis. The diagnosis of infection was based on the criteria of "definite"
diagnosis as defined by the Ohio Community-Based Pneumonia Incidence Study Group
report. The criteria included the isolation of the microorganism, the presence of
a significant antibody rise, or the presence of Legionella antigen in the urine.
RESULTS: Forty of 43 patients had admission radiographs interpreted as compatible
with pneumonia. In spite of appropriate antimicrobial therapy, worsening of the
infiltrates was found in more than half of the patients within the first week.
Twenty-seven patients were observed to have pleural effusion during the course of
hospitalization: 10 effusions were found on admission, another 14 developed
during the first week, and 3 new effusions were discovered after the first week.
Cavitation was found in only one patient. None of the patients had apical
involvement. CONCLUSION: This study confirms previous reports using less
stringent etiologic diagnosis criteria that chest radiographic findings in
Legionnaire's disease are not specific. Even with appropriate therapy, more than
half of the patients will have worsening of the infiltrates during the first
week. Pleural effusion is common among our patients, and it is frequently
detected during the serial radiographic studies during the first week of
hospitalization. Chest radiography in Legionnaire's disease is useful only for
the monitoring of disease progression and not for diagnostic purposes. In
addition, worsening of infiltrates and pleural effusion are seen in more than
half of the patients in spite of appropriate therapy and clinical improvement.
PMID- 10669682
TI - Miliary coccidioidomycosis in the immunocompetent.
AB - BACKGROUND: Miliary coccidioidomycosis indicates hematogenous or lymphatic spread
of Coccidioides immitis and is characterized by the development of multiple small
granulomas throughout the lungs and other organs. Previous reports have suggested
that this disorder occurs almost exclusively in immunocompromised patients, with
most patients succumbing to progressive respiratory failure. In this article, we
describe the largest series of immunocompetent patients with miliary
coccidioidomycosis, define clinical characteristics, and outline important
aspects of diagnosis and treatment. MATERIALS AND METHODS: We identified eight
patients (five men and three women; age range, 23 to 65 years) with miliary
coccidioidomycosis diagnosed at Kern Medical Center (located in an endemic area)
from 1990 to 1997. Four of the patients were white, two were African American,
and two were Hispanic. A miliary pattern was defined as the presence of discrete
2- to 10-mm lesions diffusely distributed throughout both lung fields, as shown
on chest radiograph. Microscopic examination and culture of C immitis from
sputum, tissue, or body fluid confirmed diagnosis. Patients with HIV were
excluded. RESULTS: These patients constituted approximately 1% of those admitted
to our institution for coccidioidomycosis from 1990 to 1997. Four patients had
symptoms for < or = 1 week before admission (acute), and four had symptoms for
between 5 and 12 weeks (chronic). Four patients demonstrated a miliary pattern on
initial chest radiograph, and two of these patients received an initial diagnosis
of miliary coccidioidomycosis. Five patients required mechanical ventilation.
Arterial blood gas measurements revealed a mean PO(2) of 54.2 +/- 8. 6 mm Hg and
a mean PCO(2) of 32.5 +/- 3.2 mm Hg. Five patients developed ARDS. Five patients
had extrapulmonary involvement, with the meninges (n = 4) and skin (n = 4) being
the most common sites. All patients were treated with fluconazole and/or
amphotericin B. Three patients died; all had chronic involvement and received
mechanical ventilation. CONCLUSION: We present eight immunocompetent patients
with a lower mortality rate and better outcome than previously reported. In our
series, miliary coccidioidomycosis manifested as either an acute respiratory
illness or an advanced stage of a chronic illness occurring in the context of
widespread dissemination. All who died had chronic involvement. Prompt
recognition of miliary coccidioidomycosis is crucial, but may be hindered by the
large differential diagnosis. Important diagnostic factors include a history of
travel through endemic areas, ethnicity, immunologic status, involvement of
multiple organ sites, and pronounced hypoxemia not accounted for by the degree of
pulmonary involvement seen on chest radiograph.
PMID- 10669683
TI - Intrathoracic Kaposi's sarcoma in women with AIDS.
AB - STUDY OBJECTIVE: To describe the radiographic features of intrathoracic Kaposi's
sarcoma in women with AIDS. SUBJECTS AND METHODS: From 1987 to 1998, we
identified seven women with biopsy-proven (n = 4) or autopsy-proven (n = 3)
pulmonary Kaposi's sarcoma. Charts were reviewed for HIV risk factors, cutaneous
and/or oropharyngeal Kaposi's sarcoma, CD4 cell count, and differential diagnosis
of pulmonary disease prior to the diagnosis of pulmonary Kaposi's sarcoma. Chest
radiographs (n = 6), chest CT scans (n = 3), and reports of unavailable chest
radiograph (n = 1) closest to the time of diagnosis of pulmonary Kaposi's sarcoma
were reviewed for the following: nodular and peribronchovascular opacities;
thickened interlobular septa; pleural effusions; lymphadenopathy; and
radiographic stage. RESULTS: Mean patient age was 33 years (range, 27 to 42
years). HIV risk factors were IV drug use (n = 2), heterosexual contact (n = 3),
and both (n = 2). All patients had prior opportunistic infections. The median CD4
cell count was 18 /microL (mean, 63/microL; range, 5 to 210/microL). Cutaneous
Kaposi's sarcoma was diagnosed prior to pulmonary Kaposi's sarcoma in four
patients, subsequently in two patients, and not identified in one patient.
Oropharyngeal Kaposi's sarcoma was diagnosed prior to pulmonary Kaposi's sarcoma
in three patients. Only infection was considered in the differential diagnosis of
the patients' pulmonary disease in five patients. One patient presented with
acute hemoptysis and died, and one patient recently received a diagnosis of
pulmonary Karposi's sarcoma at another hospital. Chest radiographic findings were
the following: nodular opacities in five of seven patients (71%);
peribronchovascular opacities in six of seven patients (86%); thickened
interlobular septa in two of seven patients (29%); pleural effusion in three of
seven patients (43%); and lymphadenopathy in two of seven patients (29%). Five of
seven patients (71%) were determined to be in radiographic stage 3, one patient
in stage 1, and one patient in stage 2. CT demonstrated additional
lymphadenopathy in three of three patients, thickened interlobular septa in two
of three patients, and pleural effusion in one of three patients, but it did not
change the staging of disease in any patient. CONCLUSION: Pulmonary Kaposi's
sarcoma can cause diffuse lung disease in women with AIDS. The disease is usually
mistaken clinically for pulmonary infection.
PMID- 10669684
TI - Distribution of alpha(1)-antitrypsin alleles in patients with bronchiectasis.
AB - STUDY OBJECTIVES: Bronchiectasis has been reported in a few patients with
homozygous alpha(1)-antitrypsin (AAT) deficiency, but the distribution of AAT
alleles among bronchiectatic patients is not known. PATIENTS AND DESIGN: Two
hundred two patients, 104 men and 98 women, with a mean age (SD) of 63.7 +/- 15.4
years, had bronchiectasis diagnosed by CT scan alone (n = 178), bronchography
with or without CT scan (n = 17), or radiography alone (n = 7). AAT phenotypes
(classified according to the protease inhibitor [PI] system) were determined by
isoelectric focusing in blood samples obtained from all patients. Bronchiectasis
was primary in 121 cases and secondary in 81 patients. Allele and phenotype
frequencies were compared retrospectively between bronchiectatic patients and
healthy blood donors living in the same geographic area. RESULTS: The PI
phenotype frequencies among patients were the following: MM, 81.18%; MS, 11.88%;
MZ, 3.46%; IZ, 0.49%; IM, 0.49%; SS, 1.48%; SZ, 0.49%; and ZZ, 0.49%. The allelic
frequencies among patients were the following: M, 89.1%; S, 7.67%; Z, 2.72%; and
I, 0.49%. There was no difference in the distribution of alleles or phenotypes
either between patients and control subjects or between patients with secondary
and primary bronchiectasis. A significant difference was found between
bronchiectatic patients with and without coexisting emphysema (p = 0.028). This
difference was caused by an overrepresentation of PI*Z alleles in bronchiectatic
patients with coexisting emphysema. CONCLUSIONS: Our results do not support a
physiopathologic implication of the AAT genes in the development of
bronchiectasis. We suggest that bronchiectasis may be a consequence of emphysema
in PI*Z patients rather than a primary effect.
PMID- 10669685
TI - Sputum elastase in steady-state bronchiectasis.
AB - STUDY OBJECTIVES: To study the correlations between sputum elastase output with
clinical and sputum inflammatory and microbial factors in steady-state
bronchiectasis. DESIGN: Prospective recruitment of patients with bronchiectasis
(17 women; 48.5 +/- 16.5 years old; FEV(1)/FVC, 1.3 +/- 0.6/2.1 +/- 0.9) for
assessment of 24-h sputum output of elastase, bacteria, leukocytes, interleukin
(IL)-1beta, IL-8, tumor necrosis factor-alpha, and leukotriene B(4). Clinical
variables assessed concomitantly included 24-h sputum volume, lung spirometry,
number of lung lobes affected by bronchiectasis, and exacerbation frequency.
SETTING: Consecutive recruitment of outpatients (n = 30) in steady-state
bronchiectasis. MEASUREMENTS AND RESULTS: Twenty-four-hour sputum elastase output
correlated with 24-h sputum volume (r = 0.79, p = 0.0001); number of
bronchiectatic lung lobes (r = 0.54, p = 0.0026); percent predicted FEV(1) (r =
0. 48, p = 0.0068); percent predicted FVC (r = -0.49, p = 0.001); and leukocyte
output (r = 0.75, p = 0.0001). There was no correlation between the sputum output
of bacteria with either inflammatory or enzymatic factors (p > 0.05). CONCLUSION:
Our data highlight the importance of elastase and the possibility of independent
roles for enzymatic, inflammatory, and microbial components in the pathogenesis
of bronchiectasis. Further research on novel therapy targeting each of these
components should be pursued.
PMID- 10669686
TI - The effect of regular salbutamol on lung function and bronchial responsiveness in
patients with primary ciliary dyskinesia.
AB - STUDY OBJECTIVE: There is growing evidence that regular beta(2)-agonist use in
patients with asthma is associated with decreased airway caliber and increased
bronchial responsiveness. The aim of this study was to determine whether regular
treatment with beta(2)-agonists induces changes in lung function and bronchial
responsiveness in patients with primary ciliary dyskinesia. DESIGN: A randomized,
double-blind, placebo-controlled, crossover study. PATIENTS: Nineteen children
with primary ciliary dyskinesia. INTERVENTIONS: Subjects received inhaled
salbutamol or identical placebo (2 x 100 microg qid) for periods of 6 weeks with
a wash-out period of 4 weeks. MEASUREMENTS AND RESULTS: FEV(1) was measured
before and 3 weeks and 6 weeks after salbutamol or placebo treatment. High-dose
methacholine inhalation tests were performed before and 6 weeks after each
treatment. The provocative concentration of methacholine producing a 20% fall in
FEV(1) (PC(20)) and maximal airway narrowing (MDeltaFFEV(1)) was measured. No
significant change in FEV(1) was observed during the salbutamol or placebo
periods. No significant differences in the parameters of bronchial responsiveness
(PC(20) and MDeltaFFEV(1)) were noted as the result of either salbutamol or
placebo treatment. CONCLUSION: Our data have shown that salbutamol, inhaled
regularly for 6 weeks, did not cause either a decline in lung function or an
increase in bronchial responsiveness in subjects with primary ciliary dyskinesia.
PMID- 10669687
TI - Perceptions of asthma by adolescents at home.
AB - OBJECTIVES: To test symptom perception in asthma under natural circumstances and
to establish relationships between changes in airway obstruction as indicated by
wheeze, dyspnea, general sensations, and emotional state. DESIGN: Continuous in
vivo monitoring. METHOD: Symptom perception was tested in 30 adolescents with
severe, unstable asthma. They were continuously monitored in their homes for 72
h. Symptom perception was defined as the relation between self-reported dyspnea
and airway obstruction as evident from audible wheeze. Tracheal sounds were
continuously recorded with wireless telemetry for wheeze assessment. Dyspnea was
assessed four times per day on a Likert-type 10-point scale, as well as four
times randomly after pager remote command. The subjects kept records of use of
medication, daily activities, general symptoms, and mood state in a diary.
RESULTS: There were nine subjects with one or two wheeze episodes, another three
subjects with three or four episodes, and one subject with almost continuous
wheeze. The presence of wheeze in general related significantly to a rise (from
individual baseline) in dyspnea of > 2.5 scale points. Acute wheeze was the best
predictor of a rise in dyspnea, but prolonged wheeze correlated significantly
with negative mood and general symptoms. CONCLUSION: Patients with prolonged
airway obstruction perceived symptoms less well and were more vulnerable to
negative effects of asthma than patients with acute onset airway obstruction.
PMID- 10669688
TI - Low-dose budesonide with the addition of an increased dose during exacerbations
is effective in long-term asthma control. On behalf of the Italian Study Group.
AB - OBJECTIVES: This study was designed to compare the effects of a 6-month treatment
with budesonide 100 microg bid (low dose) and 400 microg bid (standard reference
dose) in controlling symptoms and lung function in a group of asthmatics with
moderate asthma (baseline FEV(1) > or = 50% and < or = 90% of predicted values)
previously treated with inhaled beclomethasone dipropionate (500 to 1,000
microg/d). Moreover, we investigated whether or not asthma exacerbations could be
treated by a short-term increase in the daily dose of budesonide. METHODS: After
a 2-week run-in period and 1-month treatment with a high dose of budesonide (800
microg bid), 213 patients with moderate asthma were assigned to randomized
treatments. Daily treatment included budesonide (bid) plus an additional
treatment in case of exacerbation (qid for 7 days). Treatments were as follows:
budesonide 400 microg plus placebo (group 1); budesonide 100 microg plus
budesonide 200 microg (group 2); and budesonide 100 microg plus placebo (group
3). Symptoms and a peak expiratory flow (PEF) diary were recorded and lung
function was measured each month. An exacerbation was defined as a decrease in
PEF > 30% below baseline values on 2 consecutive days. RESULTS: We found that
that 1-month treatment with a high budesonide dose remarkably reduced all asthma
symptoms. Moreover, symptoms were under control in all treatment groups
throughout the study period. Similarly, lung function improved and remained
stable, and no relevant differences between groups were observed. In each
treatment group, the majority of patients had no exacerbations. In patients
treated with the standard budesonide dose (group 1), the number of exacerbations
and days with exacerbations were significantly lower than in group 3 (intention
to-treat analysis). Additionally, patients treated with low budesonide dose plus
budesonide (group 2) experienced a significantly lower number of exacerbations
and days with exacerbations compared to group 3 (per-protocol analysis).
CONCLUSIONS: This study demonstrates that when patients with moderate asthma had
reached a stable clinical condition with a high dose of budesonide, a low dose of
budesonide (200 microg/d) is as effective as the standard dose (800 microg/d) in
the control of symptoms and lung function over a period of several months.
Furthermore, results showed that the addition of inhaled budesonide (800
microg/d) at onset of an asthmatic exacerbation has a beneficial clinical effect.
PMID- 10669689
TI - Mechanism of CO(2) retention in patients with neuromuscular disease.
AB - BACKGROUND: In many studies of patients with muscle weakness, chronic hypercapnia
has appeared to be out of proportion to the severity of muscle disease,
indicating that factors other than muscle weakness are involved in CO(2)
retention. In patients with COPD, the unbalanced inspiratory muscle loading-to
strength ratio is thought to trigger the signal for the integrated response that
leads to rapid and shallow breathing and eventually to chronic hypercapnia. This
mechanism, although postulated, has not yet been assessed in patients with
muscular dystrophy. SUBJECTS: Twenty consecutive patients (mean age, 47.6 years;
range, 23 to 67 years) were studied: 11 patients with limb-girdle dystrophy, 3
with Duchenne muscular dystrophy, 1 with Charcot-Marie-Tooth syndrome, 1 with
Becker muscular dystrophy, 1 with myotonic dystrophy, 1 with facioscapulohumeral
dystrophy, and 2 with amyotrophic lateral sclerosis, without any respiratory
complaints. Seventeen normal subjects matched for age and sex were studied as a
control group. METHODS: Routine spirometry and arterial blood gases, maximal
inspiratory and expiratory muscle pressures (MIP and MEP, respectively), and
pleural pressure during maximal sniff test (Pplsn), were measured. Mechanical
characteristics of the lung were assessed by evaluating lung resistance (RL) and
dynamic elastance (Eldyn). Eldyn was assessed as absolute value and as percent of
Pplsn; Eldyn (%Pplsn) indicates the elastic load per unit of inspiratory muscle
force. Breathing pattern was assessed in terms of time (inspiratory time [TI];
respiratory frequency [Rf]) and volume (tidal volume [VT]) components of the
respiratory cycle. RESULTS: A rapid shallow breathing pattern, as indicated by a
greater Rf/VT ratio and a lower TI, was found in study patients compared to
control subjects. Eldyn was greater in study patients, while MIP, MEP, and Pplsn
were lower. PaCO(2) inversely related to VT, TI, and Pplsn (p = 0.012, p = 0.019,
and p = 0.002, respectively), whereas it was directly related to Rf, Rf/VT,
Eldyn, and Eldyn (%Pplsn) (p < 0.004 to p < 0.0001). Also Eldyn (%Pplsn)
inversely related to TI, and the latter positively related to VT. In other words,
increase in Eldyn (%Pplsn) was associated with decrease in TI, and the latter was
associated with lower VT and greater PaCO(2). Mechanical and breathing pattern
variables were introduced in a stepwise multiple regression that selected Eldyn
(%Pplsn) (p < 0.0001; r(2) = 0.62) as a unique independent predictor of PaCO(2).
CONCLUSIONS: The present study shows that in patients with neuromuscular disease,
elastic load and respiratory muscle weakness are responsible for a rapid and
shallow breathing pattern leading to chronic CO(2) retention.
PMID- 10669690
TI - Hypercapnic ventilatory response in patients with and without obstructive sleep
apnea: do age, gender, obesity, and daytime PaCO(2) matter?
AB - STUDY OBJECTIVE: To evaluate the relationship between obstructive sleep apnea
(OSA) and ventilatory responsiveness to carbon dioxide in both men and women.
DESIGN: An analysis of 219 patients referred to an university-based sleep center
between 1989 to 1994 was conducted (104 with OSA and 115 without OSA; 43 women
and 176 men). These patients had spirometry and a daytime hypercapnic ventilatory
response (HCVR) test that was corrected to the patient's ability to attain
maximal ventilation. Comparisons between OSA and no-OSA groups, as well as
between men and women, were made using multivariate modeling techniques. RESULTS:
There was no significant difference in the slope of correlated HCVR (cHCVR)
between those with and without OSA (1.57 +/- 0.57 vs 1.63 +/- 0.66; p = 0.48). In
men, an inverse correlation between daytime PCO(2) and cHCVR was observed in both
crude and multivariate analyses (crude beta-coefficient = - 0.04 +/- 0.02, p =
0.02; adjusted beta-coefficient = 0.07 +/- 0.02, p < 0.01). Although age and
cHCVR did not share a significant relationship in the crude analysis (crude beta
coefficient = - 0.01 +/- 0.01, p = 0.10), with adjustments for confounding
variables, a significant inverse relationship between age and cHCVR was observed
(beta-coefficient = - 0.02 +/- 0.01, p = 0.04). On the other hand, in women, only
body mass index (BMI) was positively correlated with cHCVR (crude beta
coefficient = 0.03 +/- 0.01, p = 0.01; adjusted beta-coefficient = 0.04 +/- 0.01,
p < 0.01). CONCLUSION: OSA disorder is not associated with a blunted ventilatory
chemoresponsiveness to carbon dioxide. Elevated PaCO(2) and older age are
significant correlates for a low cHCVR in men. For women only, BMI was associated
with cHCVR. These findings suggest that men and women may have different
ventilatory control mechanisms.
PMID- 10669691
TI - Effects of sleep stage and age on short-term heart rate variability during sleep
in healthy infants and children.
AB - STUDY DESIGN: Power spectrum analysis of heart rate variability (HRV) is a
noninvasive technique that provides a quantitative assessment of cardiovascular
neural control. Using this technique, we studied the autonomic nervous system
changes induced by sleep in 14 healthy subjects: 7 infants (mean age, 9.40 +/-
2.32 months) and 7 children (mean age, 8.93 +/- 0.65 years) during a standard all
night polysomnographic recording. Our primary aim was to assess the effect of
sleep stage and age on short-term HRV during sleep in healthy infants and
children. Power spectral density was estimated by autoregressive modeling over
250 consecutive R-R intervals. In this study, we mainly considered two spectral
components: the high-frequency (HF) component (0.15 to 0.40 Hz), which reflects
parasympathetic cardiovascular modulation; and the low-frequency (LF) component
(0.04 to 0.15 Hz), generally considered due to both parasympathetic and
sympathetic modulation. RESULTS: Heart rate was higher (p < 0.01 in all sleep
stages) and total power lower (p < 0. 02) in infants than in children. HF power
was higher in children than in infants (p < 0.05). In infants and children, the
ratio between LF and HF powers changed with the various sleep stages (p < 0.02 in
infants; p < 0.01 in children): it decreased during deep sleep and increased
during rapid eye movement sleep. However, it was invariably lower in children
than in infants. CONCLUSION: These findings show that the sleep stage and age
both significantly influence short-term HRV during sleep in healthy infants and
children. Hence, to provide unbiased results, HRV studies investigating the
effects of age on autonomic nervous system activity should segment sleep into the
five stages. In addition, despite a relatively small study sample, our data
confirm greater parasympathetic control during sleep in children than in infants.
PMID- 10669692
TI - The effect of respiratory therapist-initiated treatment protocols on patient
outcomes and resource utilization.
AB - CONTEXT: Physicians frequently prescribe respiratory treatments to hospitalized
patients, but the influence of such treatments on clinical outcomes is difficult
to assess. OBJECTIVE: To compare the clinical outcomes of patients receiving
respiratory treatments managed by respiratory care practitioner (RCP)-directed
treatment protocols or physician-directed orders. DESIGN: A single center, quasi
randomized, clinical study. SETTING: Three internal medicine firms from an urban
teaching hospital. PATIENTS: Six hundred ninety-four consecutive hospitalized non
ICU patients ordered to receive respiratory treatments. MAIN OUTCOME MEASURES:
Discordant respiratory care orders, respiratory care charges, hospital length of
stay, and patient-specific complications. Discordant orders were defined as
written orders for respiratory treatments that were not clinically indicated as
well as orders omitting treatments that were clinically indicated according to
protocol-based treatment algorithms. RESULTS: Firm A patients (n = 239) received
RCP-directed treatments and had a statistically lower rate of discordant
respiratory care orders (24.3%) as compared with patients receiving physician
directed treatments in firms B (n = 205; 58.5%) and C (n = 250; 56.8%; p <
0.001). No statistically significant differences in patient complications were
observed. The average number of respiratory treatments and respiratory care
charges were statistically less for firm A patients (10.7 +/- 13.7 treatments;
$868 +/- 1,519) as compared with patients in firms B (12.4 +/- 12.7 treatments,
$1,124 +/- 1,339) and C (12.3 +/- 13.4 treatments, $1, 054 +/- 1,346; p = 0.009
[treatments] and p < 0.001 [respiratory care charges]). CONCLUSIONS: Respiratory
care managed by RCP-directed treatment protocols for non-ICU patients is safe and
showed greater agreement with institutional treatment algorithms as compared with
physician-directed respiratory care. Additionally, the overall utilization of
respiratory treatments was significantly less among patients receiving RCP
directed respiratory care.
PMID- 10669693
TI - Osteoporosis and lung transplantation: a prospective study.
AB - STUDY OBJECTIVE: Osteoporosis is a well-recognized complication of lung
transplantation that may significantly impair the quality of life of transplant
recipients. We performed a prospective study of bone mineral density (BMD) before
and after transplantation to determine the degree of bone mass loss associated
with lung transplantation Patients and design: We conducted a prospective study
of BMD in 28 patients with various end-stage respiratory diseases
pretransplantation and 6 to 12 months posttransplantation. The BMD of the lumbar
spine (LS) and femoral neck (FN) were measured. All 28 patients were treated only
with vitamin D and calcium supplementation posttransplant. The primary endpoint
was the percentage change in BMD. The secondary endpoint was the incidence of
fractures posttransplant. A univariate analysis was conducted to determine the
various risk factors associated with bone mass loss pretransplant and
posttransplant. RESULTS: Prior to transplantation, moderate to severe bone
disease was evident. The mean (+/- SD) pretransplant T score (the number of SDs
from the peak bone mass) and Z score (the number of SDs from the age-matched
mean) for the LS were -1.72 +/- 1.37 and -1.44 +/- 1.31, respectively. The mean
pretransplant T score and Z score for the FN were -2.65 +/- 1.01 and -1.5 +/-
1.43, respectively. Within 6 to 12 months posttransplant, the mean BMD for the LS
decreased by 4.76% (p < 0.001), while the mean BMD for the FN decreased by 5.3%
(p < 0.001). Five of the 28 patients (18%) suffered osteoporotic fractures
posttransplant, while no fractures were documented pretransplant. The cumulative
steroid dose posttransplant was associated with a drop in BMD for the LS and FN
(r = 0.39, p = 0.039 and r = 0.63, p < 0.001, respectively), while a negative
association was found between cumulative steroid use pretransplant and baseline
LS and FN T scores (r = -0.4, p = 0. 02 and r = -0.43, p = 0.023, respectively).
CONCLUSION: Within 6 to 12 months after lung transplantation, there is a
significant decrease in BMD at both the LS and FN levels (approximately 5%)
despite vitamin D and calcium supplementation. This drop in BMD is associated
with a relatively high incidence of osteoporotic fractures posttransplant.
PMID- 10669694
TI - Mediastinal fibrosis is associated with human leukocyte antigen-A2.
AB - OBJECTIVE: To determine the association between mediastinal fibrosis and human
leukocyte antigen (HLA) genes. DESIGN: Case-control study. SETTING: Vanderbilt
University Medical Center. SUBJECTS: Nineteen consecutive patients with
mediastinal fibrosis who presented to the pulmonary clinic at Vanderbilt
University Medical Center from 1987 to 1996. The control subjects were 21,086
whites who were cadaveric kidney donors from October 1987 through December 1993.
MEASUREMENTS: HLA testing was performed on blood samples from all 19 cases.
Information on HLA typing for the control subjects was obtained from the United
Network for Organ Sharing. Frequency of HLA class I and II antigens found in the
cases was compared with the frequency in the control subjects. RESULTS: The
relative risk of mediastinal fibrosis among subjects with the HLA-A2 antigen was
3.32 times that of those who lacked this antigen (95% confidence interval, 1.19
to 9. 2). CONCLUSION: HLA-A2 was strongly associated with mediastinal fibrosis,
suggesting that an abnormal immune response is important in the pathogenesis of
this disease. Key words: Histoplasma capsulatum; human leukocyte antigen-A2;
mediastinal fibrosis
PMID- 10669695
TI - Asbestos in extrapulmonary sites: omentum and mesentery.
AB - STUDY OBJECTIVES: Asbestos fibers have not been reported in tissues from the
peritoneal cavity. Therefore, omentum, mesentery, and lung tissues from 20
individuals in whom mesothelioma was diagnosed were analyzed for asbestos bodies
and asbestos fibers. DESIGN: Tissue was digested and prepared filters were
analyzed by light microscopy and analytical transmission electron microscopy.
RESULTS: Asbestos bodies were found in the lungs of 18 individuals, mesentery
samples from 5, and omentum samples from 2. Uncoated asbestos fibers were found
in lungs of 19 patients, 17 of whom had fibers in at least one extrapulmonary
site. The most common asbestos in the omentum and mesentery was amosite. Several
features of asbestos found in lung influenced the likelihood of amphibole fibers
being found in the omentum or mesentery. Lung features included total amphibole
fiber burden, length, aspect ratio, and ferruginous body burden. An increased
total ferruginous body burden was strongly associated with increased likelihood
of detecting amphiboles in the omentum (p < 0. 05). CONCLUSION: Asbestos fibers
reach areas in the peritoneal cavity where some mesotheliomas develop. This study
suggests their presence can be predicted based on concentrations and
characteristics of fiber burdens in lung tissue.
PMID- 10669696
TI - Etiology and microbial patterns of pulmonary infiltrates in patients with
orthotopic liver transplantation.
AB - STUDY OBJECTIVE: To evaluate the etiology and microbial patterns of pulmonary
infiltrates in liver transplant patients using a bronchoscopic diagnostic
approach and the impact of diagnostic results on antimicrobial treatment
decisions. DESIGN: A prospective cohort study. SETTING: A 1,000-bed tertiary-care
university hospital. PATIENTS AND METHODS: Fifty consecutive liver transplant
patients with 60 episodes of pulmonary infiltrates (33 episodes during mechanical
ventilation) were studied using flexible bronchoscopy with protected specimen
brush (PSB) and BAL. RESULTS: A definite infectious etiology was confirmed in 29
episodes (48%). Eighteen episodes corresponded to probable pneumonia (30%), 10
episodes had noninfectious etiologies (17%), and 3 remained undetermined (5%).
Opportunistic infections were the most frequent etiology (16/29, 55%, including 1
mixed etiology). Bacterial infections (mainly Gram-negative) accounted for 14 of
29 episodes (48%), including 1 of mixed etiology. The majority of bacterial
pneumonia episodes (n = 10, 71%) occurred in period 1 (1 to 28 days
posttransplant) during mechanical ventilation, whereas opportunistic episodes
were predominant in periods 2 and 3 (29 to 180 days and > 180 days
posttransplant, respectively; n = 14, 82%). Microbial treatment was changed
according to diagnostic results in 21 episodes (35%). CONCLUSIONS: Microbial
patterns in liver transplant patients with pulmonary infiltrates corresponded to
nosocomial, mainly Gram-negative bacterial pneumonia in period 1, and to
opportunistic infections in period 2 and, to a lesser extent, period 3. A
comprehensive diagnostic evaluation including PSB and BAL fluid examination
frequently guided specific antimicrobial therapy.
PMID- 10669697
TI - Assessment of prognosis in patients with community-acquired pneumonia who require
mechanical ventilation.
AB - STUDY OBJECTIVES: Knowing that mortality is high in patients who require
mechanical ventilation patients with community-acquired pneumonia (CAP), we
hypothesized that the severity of acute lung injury could be used along with
nonpulmonary factors to identify patients with the highest risk of death. We
formulated a prediction model to quantitate the risk of hospital mortality in
this population of patients. DESIGN: Historical prospective study using data
collected over the first 24 h of mechanical ventilation. We utilized a hypoxemia
index-(1 - lowest [PaO(2)/PAO(2)]) x (minimum fraction of inspired oxygen to
maintain PaO(2) at > 60 mm Hg) x 100], where PAO(2) is the alveolar partial
pressure of oxygen-to grade the severity of acute lung injury on a scale from 0
to 100. SETTING: Tertiary care university hospital ICU. PATIENTS: One hundred
forty-four adult patients mechanically ventilated for respiratory failure caused
by CAP. MEASUREMENTS AND RESULTS: Hospital mortality was 46% (n = 66).
Multivariate logistic regression analysis revealed five independent predictors of
hospital mortality: (1) the extent of lung injury assessed by the hypoxemia
index; (2) the number of nonpulmonary organs that failed; (3) immunosuppression;
(4) age > 80 years; and (5) medical comorbidity with a prognosis for survival < 5
years. At a 50% mortality threshold, the prediction model correctly classified
outcome in 88% of cases. All patients with > 95% predicted probability of death
died in hospital. CONCLUSIONS: Based on clinical parameters measured over the
first 24 h of mechanical ventilation, this model accurately identified critically
ill, mechanically ventilated patients with CAP for whom prolonged intensive care
may not be of benefit.
PMID- 10669698
TI - Topical antibiotics on tracheostoma prevents exogenous colonization and infection
of lower airways in children.
AB - INTRODUCTION: Patients requiring long-term ventilation are at high risk of lower
airway infections, generally of endogenous development. Patients on long-term
ventilation, in particular via a tracheostomy, may develop tracheobronchitis or
pneumonia of exogenous pathogenesis, ie, caused by microorganisms not carried in
the oropharynx. The frequency of exogenous colonization or infection has
previously been reported to be as high as 33%. A prospective observational cohort
study of 2 years was undertaken to evaluate the efficacy of topical antibiotics
in the prevention of exogenous colonization or infection of the lower airways.
The antibiotic combination of polymyxin E and tobramycin in a 2% paste was
applied four times a day on the tracheostoma. MATERIALS AND METHODS: A total of
23 children (median age, 4.1 months; range, 0 to 215 months) were enrolled in the
study from September 1, 1996, until August 30, 1998. Surveillance samples of the
oropharynx were obtained before tracheostomy and thereafter twice weekly.
Diagnostic samples of the lower airways were taken once weekly and on clinical
indication. RESULTS: Fourteen children (61%) had a total of 16 episodes of
tracheal colonization or infection with 20 potentially pathogenic microorganisms.
Only one child had tracheobronchitis with Streptococcus pneumoniae and
Haemophilus influenzae during the 2-year study. Of the 16 colonization episodes,
12 (75%) were of primary endogenous pathogenesis, ie, caused by microorganisms
present in the oropharynx at the time of tracheostomy. Community microorganisms
including S pneumoniae, H influenzae, Moraxella (Branhamella) catarrhalis, and
Staphylococcus aureus were the predominating bacteria. Three patients acquired
nosocomial bacteria Pseudomonas aeruginosa and Hafnia alvei in the oropharynx,
subsequently followed by secondary colonization of the lower airways. There was
one failure of the prophylaxis: one patient (4%) had exogenous colonization with
Pseudomonas pickettii. CONCLUSION: Topical antibiotics applied to the
tracheostoma were found to be effective in reducing the exogenous route of
colonization of the lower respiratory tract, compared with clinical experience
and the literature. This promising technique requires further evaluation in
randomized trials.
PMID- 10669699
TI - beta-agonistic bronchodilators: comparison of dose/response in working rat
hearts.
AB - STUDY OBJECTIVES: Different beta-agonists are compared with regard to their
cardiodepressive side effects. DESIGN: The metaphenolic bronchodilators
reproterol, salbutamol, fenoterol, and terbutaline were introduced at a dosage of
0.0005 micromol to a maximum of 10 micromol per gram of heart tissue into the
isolated working rat heart under hypoxic conditions, and the response was
observed during subsequent reoxygenation. As an index of external heart work,
aortic flow was measured. Heart rate, coronary flow, and developed pressure were
recorded. At the end of heart perfusion, mitochondria were isolated and analyzed
for adenosine triphosphatase activity, adenosine triphosphate (ATP) synthesis,
and membrane fluidity. Moreover, intact mitochondria and lipid peroxidation were
investigated using a model system. MEASUREMENTS AND RESULTS: Compared to
controls, reproterol gave the most favorable results, with an increase of 25 to
30% of aortic flow during reoxygenation at a concentration of 10 micromol/g heart
tissue. In contrast, both fenoterol and salbutamol at a concentration of 1
micromol/g heart tissue decreased aortic flow during reoxygenation, whereas
terbutaline had a negative influence on aortic flow at 0.01 to 0.1 micromol/g
heart tissue. Mitochondria of these hearts were isolated at the end of the
experiment. Mitochondrial ATP synthesis was increased above controls at nearly
all concentrations of reproterol. ATP synthesis was decreased at 1 micromol and
10 micromol fenoterol. As little as 0.0005 micromol terbutaline decreased ATP
synthesis by 50%. In intact mitochondria, adenosine diphosphate (ADP) to oxygen
ratios were found to be increased with terbutaline and fenoterol, indicating ADP
consumption by myokinase activation. Lipid peroxidation was increased in a model
system between concentrations of 0.002 micromol/mg and 0.04 micromol/mg
phosphatidylcholine by fenoterol and terbutaline, whereas a decrease was noted
with reproterol. Membrane fluidity was found increased after addition of
reproterol, which supports the evidence of efficient ATP synthesis by this
compound. CONCLUSIONS: Cardiodepressive side effects and greater toxicity of
fenoterol and terbutaline were found under the conditions of our experiment.
Salbutamol and, in particular, reproterol appear much better tolerated. In
addition to partial beta-adrenergic agonism, reproterol may exert an inhibitory
influence on adenosine receptor sites and phosphodiesterase, which could result
in membrane stabilization by saving cyclic adenosine monophosphate or ATP.
PMID- 10669700
TI - The drug-resistant pneumococcus: clinical relevance, therapy, and prevention.
AB - Streptococcus pneumoniae has been known for > 100 years as the most important
bacterial pathogen of the respiratory tract in adults and children. In recent
years, the pneumococcus has begun to exhibit increasing resistance to
antimicrobial agents. Because of the huge number of infections caused by this
organism, the development of resistance has changed the approach to many
infectious disease problems, particularly with regard to empiric antibiotic
therapy and prophylaxis. In our review of the antibiotic-resistant pneumococcus,
we review the microbiologic basis for resistance, risk factors for and clinical
relevance of infection by a resistant organism, and infection control measures.
PMID- 10669701
TI - Inhaled corticosteroids for asthma therapy: patient compliance, devices, and
inhalation technique.
AB - BACKGROUND: Patient compliance, inhalation devices, and inhalation techniques
influence the effectiveness of inhaled medications. METHODS: This article
presents the results of a systematic literature review of studies measuring
compliance with inhaled corticosteroids, measuring inhalation technique with
different inhalation devices, and estimating the proportion of inhaled drug that
is deposited in the lung. RESULTS: Overall, patients took the recommended doses
of inhaled medication on 20 to 73% of days. Frequency of efficient inhalation
technique ranged from 46 to 59% of patients. Education programs have been shown
to improve compliance and inhalation techniques. The lung deposition achieved
with different inhalers depends on particle size as well as inhaler technique.
CONCLUSION: This review demonstrates that multiple factors may come between a
prescription of an inhaled corticosteroid and the arrival of that medicine at its
target organ, the lung.
PMID- 10669702
TI - Neuraxial blockade and hematoma in cardiac surgery: estimating the risk of a rare
adverse event that has not (yet) occurred.
PMID- 10669703
TI - Long-term value of exercise testing after acute myocardial infarction: influence
of thrombolytic therapy.
AB - OBJECTIVES: To evaluate the long-term predictive value of exercise testing
performed early after acute myocardial infarction (AMI) in patients receiving
thrombolytic therapy. DESIGN: Nonblinded prospective follow-up study. SETTING:
Cardiac rehabilitation unit in a 900-bed university hospital. SUBJECTS: Four
hundred forty-three patients allowed to perform exercise testing 3 weeks after
AMI were followed for a median of 75 months; 183 received IV thrombolysis and 263
did not. RESULTS: Cardiac death hazard ratios were significantly increased in the
presence of reduced physical working capacity on exertion, left ventricular
dysfunction, and > or = 1-mm (but < 2-mm) ST-segment depression on exertion. In
the group receiving thrombolytic therapy, no patient with > or = 2-mm ST-segment
depression on exercise died; this group was characterized by a high rate of
revascularization, whereas the group with > or = 1-mm but < 2-mm ST-segment
depression was not. No parameter related to clinical or exercise testing
predicted recurrent infarction in the group receiving thrombolytic therapy. Among
patients not receiving thrombolysis, cardiac death was significantly related to >
or = 2-mm ST-segment depression on exertion, to reduced physical working
capacity, and to the lack of revascularization during follow-up. CONCLUSION:
Exercise test-derived parameters have variable value in predicting long-term
survival of patients performing exercise test after AMI depending on the
following: (1) whether thrombolytic therapy was given or not; (2) the degree of
ST-segment depression during exercise testing; and (3) the rate of
revascularization.
PMID- 10669704
TI - Clinical conference on management dilemmas: progressive infiltrates and
respiratory failure.
PMID- 10669705
TI - A prospective study of fever and bacteremia after flexible fiberoptic
bronchoscopy in children.
AB - STUDY OBJECTIVES: To assess the incidence of fever and bacteremia after
fiberoptic bronchoscopy in immunocompetent children. DESIGN: Prospective study.
PATIENTS: Immunocompetent children undergoing fiberoptic bronchoscopy between
January 1997 and June 1998. MEASUREMENTS AND RESULTS: Ninety-one children were
included in the study. Forty-four children (48%) developed fever within 24 h
following bronchoscopy. Bacteremia was not detected in any of the cases at the
time of the fever. Children who developed fever were younger than those who
remained afebrile (mean age, 2.4 +/- 3.6 years vs 4.2 +/- 3.7 years; p = 0.025).
In the fever group, 66% of the bronchoscopies were considered abnormal, compared
to 45% in the nonfever group (p = 0.04). Of the fever group, 40.5% of BAL fluid
cultures had significant bacterial growth, significantly higher compared to the
nonfever group (13.2%; p = 0.006). Of the 80 patients in whom BAL was performed,
fever occurred in 52.5% compared to only 18.2% in those who did not have BAL (p =
0.03). BAL fluid content of cell count, lipid-laden macrophages, and interleukin
8 were not significantly different in both groups. In a logistic regression
analysis, the significant predictors for developing fever were positive bacterial
culture (relative risk, 5.1; 95% confidence interval, 1.6 to 16.4; p = 0.007) and
abnormal bronchoscopic findings (relative risk, 3.1, 95% confidence interval, 1.2
to 8.3; p = 0.02). When age < 2 years was included in the model, this factor
became highly significant (relative risk, 5.01; 95% confidence interval, 1.83 to
13.75; p < 0.002). CONCLUSIONS: Fever following fiberoptic bronchoscopy is a
common event in immunocompetent children and is not associated with bacteremia.
Risks to develop this complication are age < 2 years, positive bacterial cultures
in BAL fluid, and abnormal bronchoscopic findings.
PMID- 10669706
TI - The invaluable pressure-volume curve.
AB - We present a case in which the pressure-volume (P-V) curve proved invaluable in
the diagnostic workup of a patient. The patient was a 43-year-old man who
presented with progressive dyspnea on exertion, restrictive spirometry, exercise
desaturation, and an unremarkable CT scan. Because of the unexpected finding of
an unremarkable CT scan, we wanted more data assuring the presence of an
indication for lung biopsy. Detailed pulmonary function tests, including a P-V
curve, were administered. The P-V curve was abnormal, thus prompting a biopsy,
which revealed hypersensitivity pneumonitis. In this report, we discuss the use
of P-V curves and the clinical presentation of hypersensitivity pneumonitis.
PMID- 10669707
TI - A 69-year-Old woman with CREST syndrome, dyspnea, and a mosaic CT attenuation
pattern.
PMID- 10669708
TI - Persistant right lower lobe consolidation.
PMID- 10669709
TI - Complete remission of pulmonary spindle cell carcinoma after treatment with oral
germanium sesquioxide.
AB - Spindle cell carcinoma (SCC) is a rare form of lung cancer representing 0.2 to
0.3% of all primary pulmonary malignancies. Even with combined surgery,
chemotherapy, and radiation therapy, these tumors are associated with a poor
prognosis and only 10% of patients survive 2 years after diagnosis. We describe a
patient with an unresectable SCC who, following no response to conventional
treatment with combined modality therapy, chose to medicate herself with daily
doses of germanium obtained in a health food store. She noted prompt symptomatic
improvement and remains clinically and radiographically free of disease 42 months
after starting her alternative therapy.
PMID- 10669710
TI - Asthma and Cushing's syndrome.
AB - A female patient was treated with high-dose inhaled fluticasone propionate for
her asthma. Over 2 years, she developed features of Cushing's syndrome with
proximal myopathy, osteopenia, hypertension, depressive psychosis, and cushingoid
appearance. She had biochemical evidence of marked adrenal suppression with a
9:00 AM serum cortisol of 20 nmol/L that returned to normal (315 mol/L) after her
therapy was changed to budenoside, 0.8 mg/d. Her appearance, mental state, and
myopathy also improved with no loss of asthma control. This case illustrates the
potential for developing clinically relevant adverse effects of inhaled
corticosteroids when given at licensed doses.
PMID- 10669711
TI - Acute massive pulmonary embolism in a Jehovah's witness: successful treatment
with catheter thrombectomy.
AB - A 71-year-old woman presented with an acute, massive pulmonary embolism. As a
Jehovah's Witness, she was not willing to accept thrombolysis because of the
potential risk of bleeding requiring blood transfusion. The patient was
successfully treated with catheter thrombectomy, using rheolytic and
fragmentation devices. (CHEST 2000; 117:594-597)
PMID- 10669712
TI - Carbamazepine-induced systemic lupus erythematosus presenting as cardiac
tamponade.
AB - Here we report the case of a patient who presented with acute cardiac tamponade
due to drug-induced systemic lupus erythematosus (SLE). The patient had been
treated for a seizure disorder with carbamazepine, a drug that has previously
been demonstrated to cause SLE-like syndromes. Further serologic analysis
demonstrated the likelihood of drug-induced SLE in this patient, with the rare
presentation of cardiac tamponade.
PMID- 10669713
TI - Pedal (99m)Tc-sulfur colloid lymphoscintigraphy in primary isolated
chylopericardium.
AB - Primary isolated chylopericardium is a rare disorder in which chylous fluid
accumulates in the pericardial space. In this case report of a 61-year-old man
with chylopericardium, pedal (99m)Tc-sulfur colloid (SC) lymphoscintigraphy was
performed after emergent pericardiocentesis, and when there was a recurrent
massive pericardial effusion. The results showed that (99m)Tc-SC
lymphoscintigraphy can clearly reveal the lymphodynamics in patients with primary
isolated chylopericardium. This noninvasive investigation is valuable and can be
easily performed either before or after pericardiocentesis.
PMID- 10669714
TI - A large false aneurysm of the right ventricle within a giant epicardial lipoma.
AB - Lipomas, which account for approximately 10% of all neoplasms of the heart, may
be detected in asymptomatic patients by chance during echocardiography, CT scan,
or MRI scan. Occasionally, lipomas are complicated by arrhythmias. We describe a
patient who presented with severe cardiomegaly and paroxysmal supraventricular
tachycardia. An MRI scan showed a large intrapericardial lipoma with two large
cavities inside communicating with each other and with the right ventricular
chamber through a defect of the right ventricular wall. The mass was partially
removed, and the right ventricle was patched. Surgery combined with
antiarrhythmic therapy resulted in a good short-term result.
PMID- 10669715
TI - Paraneoplastic pemphigus associated with bronchiolitis obliterans.
AB - Paraneoplastic pemphigus (PNP) is an autoantibody-mediated mucocutaneous
blistering disease associated with underlying neoplasms. Autoantibodies of PNP
bind to the plakin family of cytoplasmic proteins and desmogleins of cell-surface
target antigens. We describe a 36-year-old female patient with PNP who had non
Hodgkin's lymphoma, and who developed bronchiolitis obliterans and died of
respiratory failure. Autopsy findings confirmed luminal narrowing of bronchioles
by scarring, which is a histopathologic features of bronchiolitis obliterans.
After the onset of respiratory failure, the reaction of autoantibodies against
the plakins detected by immunoprecipitation at the onset of PNP disappeared with
negative immunofluorescence within the bronchial epithelium. It is thought that
autoantibodies against some of these antigens play a role in causing acute
inflammation of the respiratory epithelium. In treating PNP, the possibility of
the patient developing the lethal complication bronchiolitis obliterans should be
kept in mind. Furthermore, prevention of the initial autoantibody-mediated injury
to the respiratory epithelium should be an important treatment goal.
PMID- 10669716
TI - Factors contributing to pneumothorax after thoracentesis.
PMID- 10669717
TI - Longitudinal data on positive tuberculin skin tests from three US states.
PMID- 10669718
TI - Salmeterol and tolerance.
PMID- 10669719
TI - Use of fluticasone in asthma.
PMID- 10669720
TI - Confident diagnosis of solitary fibrous tumor of the pleura using cutting-needle
biopsy.
PMID- 10669721
TI - Fatal pulmonary hemorrhage during high-dose valproate monotherapy.
PMID- 10669722
TI - The mechanism of hypoxemia in liver disease with pulmonary hypertension.
PMID- 10669723
TI - Community-acquired chlamydia pneumoniae pneumonia.
PMID- 10669725
TI - TATA-binding protein mutants that increase transcription from enhancerless and
repressed promoters in vivo.
AB - Using a genetic screen, we isolated three TATA-binding protein (TBP) mutants that
increase transcription from promoters that are repressed by the Cyc8-Tup1 or Sin3
Rpd3 corepressors or that lack an enhancer element, but not from an equivalently
weak promoter with a mutated TATA element. Increased transcription is observed
when the TBP mutants are expressed at low levels in the presence of wild-type
TBP. These TBP mutants are unable to support cell viability, and they are toxic
in strains lacking Rpd3 histone deacetylase or when expressed at higher levels.
Although these mutants do not detectably bind TATA elements in vitro, genetic and
chromatin immunoprecipitation experiments indicate that they act directly at
promoters and do not increase transcription by titration of a negative regulatory
factor(s). The TBP mutants are mildly defective for associating with promoters
responding to moderate or strong activators; in addition, they are severely
defective for RNA polymerase (Pol) III but not Pol I transcription. These results
suggest that, with respect to Pol II transcription, the TBP mutants specifically
increase expression from core promoters. Biochemical analysis indicates that the
TBP mutants are unaffected for TFIID complex formation, dimerization, and
interactions with either the general negative regulator NC2 or the N-terminal
inhibitory domain of TAF130. We speculate that these TBP mutants have an unusual
structure that allows them to preferentially access TATA elements in chromatin
templates. These TBP mutants define a criterion by which promoters repressed by
Cyc8-Tup1 or Sin3-Rpd3 resemble enhancerless, but not TATA-defective, promoters;
hence, they support the idea that these corepressors inhibit the function of
activator proteins rather than the Pol II machinery.
PMID- 10669724
TI - Regulatory and signaling properties of the Vav family.
PMID- 10669726
TI - Insulin-like growth factor I-induced degradation of insulin receptor substrate 1
is mediated by the 26S proteasome and blocked by phosphatidylinositol 3'-kinase
inhibition.
AB - Insulin receptor substrate 1 (IRS-1) is a critical adapter protein involved in
both insulin and insulin-like growth factor (IGF) signaling. Due to the fact that
alteration of IRS-1 levels can affect the sensitivity and response to both
insulin and IGF-I, we examined the ability of each of these ligands to affect IRS
1 expression. IGF-I (10 nM) stimulation of MCF-7 breast cancer cells caused a
transient tyrosine phosphorylation of IRS-1 that was maximal at 15 min and
decreased thereafter. The decrease in tyrosine phosphorylation of IRS-1 was
paralleled by an apparent decrease in IRS-1 levels. The IGF-mediated decrease in
IRS-1 expression was posttranscriptional and due to a decrease in the half-life
of the IRS-1 protein. Insulin (10 nM) caused tyrosine phosphorylation of IRS-1
but not degradation, whereas high concentrations of insulin (10 microM) resulted
in degradation of IRS-1. IGF-I (10 nM) stimulation resulted in transient IRS-1
phosphorylation and extracellular signal-related kinase (ERK) activation. In
contrast, insulin (10 nM) caused sustained IRS-1 phosphorylation and ERK
activation. Inhibition of 26S proteasome activity by the use of lactacystin or
MG132 completely blocked IGF-mediated degradation of IRS-1. Furthermore,
coimmunoprecipitation experiments showed an association between ubiquitin and IRS
1 that was increased by treatment of cells with IGF-I. Finally, IGF-mediated
degradation of IRS-1 was blocked by inhibition of phosphatidylinositol 3'-kinase
activity but was not affected by inhibition of ERK, suggesting that this may
represent a direct negative-feedback mechanism resulting from downstream IRS-1
signaling. We conclude that IGF-I can cause ligand-mediated degradation of IRS-1
via the ubiquitin-mediated 26S proteasome and a phosphatidylinositol 3'-kinase
dependent mechanism and that control of degradation may have profound effects on
downstream activation of signaling pathways.
PMID- 10669727
TI - Distinct roles for Galpha(i)2 and Gbetagamma in signaling to DNA synthesis and
Galpha(i)3 in cellular transformation by dopamine D2S receptor activation in
BALB/c 3T3 cells.
AB - Control of cell proliferation depends on intracellular mediators that determine
the cellular response to external cues. In neuroendocrine cells, the dopamine D2
receptor short form (D2S receptor) inhibits cell proliferation, whereas in
mesenchymal cells the same receptor enhances cell proliferation. Nontransformed
BALB/c 3T3 fibroblast cells were stably transfected with the D2S receptor cDNA to
study the G proteins that direct D2S signaling to stimulate cell proliferation.
Pertussis toxin inactivates G(i) and G(o) proteins and blocks signaling of the
D2S receptor in these cells. D2S receptor signaling was reconstituted by
individually transfecting pertussis toxin-resistant Galpha(i/o) subunit mutants
and measuring D2-induced responses in pertussis toxin-treated cells. This
approach identified Galpha(i)2 and Galpha(i)3 as mediators of the D2S receptor
mediated inhibition of forskolin-stimulated adenylyl cyclase activity; Galpha(i)2
mediated D2S-induced stimulation of p42 and p44 mitogen-activated kinase (MAPK)
and DNA synthesis, whereas Galpha(i)3 was required for formation of transformed
foci. Transfection of toxin-resistant Galpha(i)1 cDNA induced abnormal cell
growth independent of D2S receptor activation, while Galpha(o) inhibited dopamine
induced transformation. The role of Gbetagamma subunits was assessed by ectopic
expression of the carboxyl-terminal domain of G protein receptor kinase to
selectively antagonize Gbetagamma activity. Mobilization of Gbetagamma subunits
was required for D2S-induced calcium mobilization, MAPK activation, and DNA
synthesis. These findings reveal a remarkable and distinct G protein specificity
for D2S receptor-mediated signaling to initiate DNA synthesis (Galpha(i)2 and
Gbetagamma) and oncogenic transformation (Galpha(i)3), and they indicate that
acute activation of MAPK correlates with enhanced DNA synthesis but not with
transformation.
PMID- 10669728
TI - Caveolin 1-mediated regulation of receptor tyrosine kinase-associated
phosphatidylinositol 3-kinase activity by ceramide.
AB - Previous studies have indicated that proapoptotic stresses downregulate the
phosphatidylinositol 3-kinase [PI(3)K]/Akt survival pathway via the activation of
acid-sphingomyelinase (A-SMase) and ceramide production. Ceramide induces
apoptosis and inhibits PI(3)K activity without altering expression, association,
or phosphorylation of receptors, adapter proteins, or PI(3)K subunits. PI(3)K
inhibition by ceramide is associated with recruitment of caveolin 1 to PI(3)K
associated receptor complexes within lipid raft microdomains. Overexpression of
caveolin 1 alone is sufficient to alter PI(3)K activity and sensitizes
fibroblasts to ceramide-induced cell death. Most importantly, antisense
expression of caveolin 1 dramatically reduces ceramide-induced PI(3)K
deregulation and results in a loss-of-function stress response similar to that in
A-SMase-deficient cells. Stress-induced recruitment of caveolin 1 to receptor
complexes was found to be dependent on A-SMase since cell lines deficient in A
SMase did not exhibit caveolin 1 association with PI(3)K receptor complexes.
Thus, a genetic link between A-SMase activation and caveolin 1-induced inhibition
of PI(3)K activity exists. These results led us to propose that stress-induced
changes in raft microdomains lead to altered receptor tyrosine kinase signal
transduction through the modulation of caveolin 1 by ceramide.
PMID- 10669729
TI - Complex protein interactions within the human polyadenylation machinery identify
a novel component.
AB - Polyadenylation of mRNA precursors is a two-step reaction requiring multiple
protein factors. Cleavage stimulation factor (CstF) is a heterotrimer necessary
for the first step, endonucleolytic cleavage, and it plays an important role in
determining the efficiency of polyadenylation. Although a considerable amount is
known about the RNA binding properties of CstF, the protein-protein interactions
required for its assembly and function are poorly understood. We therefore first
identified regions of the CstF subunits, CstF-77, CstF-64, and CstF-50, required
for interaction with each other. Unexpectedly, small regions of two of the
subunits participate in multiple interactions. In CstF-77, a proline-rich domain
is necessary not only for binding both other subunits but also for self
association, an interaction consistent with genetic studies in Drosophila. In
CstF-64, a small region, highly conserved in metazoa, is responsible for
interactions with two proteins, CstF-77 and symplekin, a nuclear protein of
previously unknown function. Intriguingly, symplekin has significant similarity
to a yeast protein, PTA1, that is a component of the yeast polyadenylation
machinery. We show that multiple factors, including CstF, cleavage
polyadenylation specificity factor, and symplekin, can be isolated from cells as
part of a large complex. These and other data suggest that symplekin may function
in assembly of the polyadenylation machinery.
PMID- 10669730
TI - Molecular mechanism for the Shp-2 tyrosine phosphatase function in promoting
growth factor stimulation of Erk activity.
AB - We have previously shown that activation of extracellular signal-regulated kinase
(Erk) by epidermal growth factor (EGF) treatment was significantly decreased in
mouse fibroblast cells expressing a mutant Shp-2 molecule lacking 65 amino acids
in the SH2-N domain, Shp-2(Delta46-110). To address the molecular mechanism for
the positive role of Shp-2 in mediating Erk induction, we evaluated the
activation of signaling components upstream of Erk in Shp-2 mutant cells. EGF
stimulated Ras, Raf, and Mek activation was significantly attenuated in Shp-2
mutant cells, suggesting that Shp-2 acts to promote Ras activation or to suppress
the down-regulation of activated Ras. Biochemical analyses indicate that upon EGF
stimulation, Shp-2 is recruited into a multiprotein complex assembled on the Gab1
docking molecule and that Shp-2 seems to exert its biological function by
specifically dephosphorylating an unidentified molecule of 90 kDa in the complex.
The mutant Shp-2(Delta46-110) molecule failed to participate in the Gab1
organized complex for dephosphorylation of p90, correlating with a defective
activation of the Ras-Raf-Mek-Erk cascade in EGF-treated Shp-2 mutant cells.
Evidence is also presented that Shp-2 does not appear to modulate the signal
relay from EGF receptor to Ras through the Shc, Grb2, and Sos proteins. These
results begin to elucidate the mechanism of Shp-2 function downstream of a
receptor tyrosine kinase to promote the activation of the Ras-Erk pathway, with
potential therapeutic applications in cancer treatment.
PMID- 10669731
TI - Nck-interacting Ste20 kinase couples Eph receptors to c-Jun N-terminal kinase and
integrin activation.
AB - The mammalian Ste20 kinase Nck-interacting kinase (NIK) specifically activates
the c-Jun amino-terminal kinase (JNK) mitogen-activated protein kinase module.
NIK also binds the SH3 domains of the SH2/SH3 adapter protein Nck. To determine
whether Nck functions as an adapter to couple NIK to a receptor tyrosine kinase
signaling pathway, we determined whether NIK is activated by Eph receptors
(EphR). EphRs constitute the largest family of receptor tyrosine kinases (RTK),
and members of this family play important roles in patterning of the nervous and
vascular systems. In this report, we show that NIK kinase activity is
specifically increased in cells stimulated by two EphRs, EphB1 and EphB2. EphB1
kinase activity and phosphorylation of a juxtamembrane tyrosine (Y594), conserved
in all Eph receptors, are both critical for NIK activation by EphB1. Although
pY594 in the EphB1R has previously been shown to bind the SH2 domain of Nck, we
found that stimulation of EphB1 and EphB2 led predominantly to a complex between
NIK/Nck, p62(dok), RasGAP, and an unidentified 145-kDa tyrosine-phosphorylated
protein. Tyrosine-phosphorylated p62(dok) most probably binds directly to the SH2
domain of Nck and RasGAP and indirectly to NIK bound to the SH3 domain of Nck. We
found that NIK activation is also critical for coupling EphB1R to biological
responses that include the activation of integrins and JNK by EphB1. Taken
together, these findings support a model in which the recruitment of the Ste20
kinase NIK to phosphotyrosine-containing proteins by Nck is an important proximal
step in the signaling cascade downstream of EphRs.
PMID- 10669732
TI - Recruitment of CREB binding protein is sufficient for CREB-mediated gene
activation.
AB - Phosphorylation of the transcription factor CREB leads to the recruitment of the
coactivator, CREB binding protein (CBP). Recent studies have suggested that CBP
recruitment is not sufficient for CREB function, however. We have identified a
conserved protein-protein interaction motif within the CBP-binding domains of
CREB and another transcription factor, SREBP (sterol-responsive element binding
protein). In contrast to CREB, SREBP interacts with CBP in the absence of
phosphorylation. We have exploited the conservation of this interaction motif to
test whether CBP recruitment to CREB is sufficient for transcriptional
activation. Substitution of six nonconserved amino acids from SREBP into the
activation domain of CREB confers high-affinity, phosphorylation-independent CBP
binding. The mutated CREB molecule, CREB(DIEDML), activates transcription in F9
teratocarcinoma and PC12 cells even in the absence of protein kinase A (PKA).
Addition of exogenous CBP augments the level of transcription mediated by
CREB(DIEDML), and adenovirus 12S E1A blocks transcription, implicating CBP in the
activation process. Thus, recruitment of CBP to CREB is sufficient for
transcriptional activation. Addition of PKA stimulates transcription induced by
CREB(DIEDML) further, suggesting that a phosphorylation event downstream from CBP
recruitment augments CREB signaling.
PMID- 10669733
TI - Timing of developmentally programmed excision and circularization of Paramecium
internal eliminated sequences.
AB - Paramecium internal eliminated sequences (IESs) are short AT-rich DNA elements
that are precisely eliminated from the germ line genome during development of the
somatic macronucleus. They are flanked by one 5'-TA-3' dinucleotide on each side,
a single copy of which remains at the donor site after excision. The timing of
their excision was examined in synchronized conjugating cells by quantitative
PCR. Significant amplification of the germ line genome was observed prior to IES
excision, which starts 12 to 14 h after initiation of conjugation and extends
over a 2- to 4-h period. Following excision, two IESs were shown to form
extrachromosomal circles that can be readily detected on Southern blots of
genomic DNA from cells undergoing macronuclear development. On these circular
molecules, covalently joined IES ends are separated by one copy of the flanking
5'-TA-3' repeat. The similar structures of the junctions formed on the excised
and donor molecules point to a central role for this dinucleotide in IES
excision.
PMID- 10669734
TI - Terminally differentiated human neurons repair transcribed genes but display
attenuated global DNA repair and modulation of repair gene expression.
AB - Repair of UV-induced DNA lesions in terminally differentiated human hNT neurons
was compared to that in their repair-proficient precursor NT2 cells. Global
genome repair of (6-4)pyrimidine-pyrimidone photoproducts was significantly
slower in hNT neurons than in the precursor cells, and repair of cyclobutane
pyrimidine dimers (CPDs) was not detected in the hNT neurons. This deficiency in
global genome repair did not appear to be due to denser chromatin structure in
hNT neurons. By contrast, CPDs were removed efficiently from both strands of
transcribed genes in hNT neurons, with the nontranscribed strand being repaired
unexpectedly well. Correlated with these changes in repair during neuronal
differentiation were modifications in the expression of several repair genes, in
particular an up-regulation of the two structure-specific nucleases XPG and
XPF/ERCC1. These results have implications for neuronal dysfunction and aging.
PMID- 10669735
TI - Nuclear import of IkappaBalpha is accomplished by a ran-independent transport
pathway.
AB - The inhibitor of kappa B alpha (IkappaBalpha) protein is able to shuttle between
the cytoplasm and the nucleus. We have utilized a combination of in vivo and in
vitro approaches to provide mechanistic insight into nucleocytoplasmic shuttling
by IkappaBalpha. IkappaBalpha contains multiple functional domains that
contribute to shuttling of IkappaBalpha between the cytoplasm and the nucleus.
Nuclear import of IkappaBalpha is mediated by the central ankyrin repeat domain.
Similar to previously described nuclear import pathways, nuclear import of
IkappaBalpha is temperature and ATP dependent and is blocked by a dominant
negative mutant of importin beta. However, in contrast to classical nuclear
import pathways, nuclear import of IkappaBalpha is independent of soluble
cytosolic factors and is not blocked by the dominant-negative RanQ69L protein.
Nuclear export of IkappaBalpha is mediated by an N-terminal nuclear export
sequence. Nuclear export of IkappaBalpha requires the CRM1 nuclear export
receptor and is blocked by the dominant-negative RanQ69L protein. Our results are
consistent with a model in which nuclear import of IkappaBalpha is mediated
through direct interactions with components of the nuclear pore complex, while
nuclear export of IkappaBalpha is mediated via a CRM1-dependent pathway.
PMID- 10669736
TI - Transient expression of cellular polypyrimidine-tract binding protein stimulates
cap-independent translation directed by both picornaviral and flaviviral internal
ribosome entry sites In vivo.
AB - The regulation of cap-independent translation directed by the internal ribosome
entry sites (IRESs) present in some viral and cellular RNAs is poorly understood.
Polypyrimidine-tract binding protein (PTB) binds specifically to several viral
IRESs. IRES-directed translation may be reduced in cell-free systems that are
depleted of PTB and restored by reconstitution of lysates with recombinant PTB.
However, there are no data concerning the effects of PTB on IRES-directed
translation in vivo. We transfected cells with plasmids expressing dicistronic
transcripts in which the upstream cistron encoded PTB or PTB deletion mutants
(including a null mutant lacking amino acid residues 87 to 531). The downstream
cistron encoded a reporter protein (chloramphenicol acetyltransferase [CAT])
under translational control of the poliovirus IRES which was placed within the
intercistronic space. In transfected BS-C-1 cells, transcripts expressing wild
type PTB produced 12-fold more reporter protein than similar transcripts encoding
the PTB null mutant. There was a 2.4-fold difference in CAT produced from these
transcripts in HeLa cells, which contain a greater natural abundance of PTB. PTB
similarly stimulated CAT production from transcripts containing the IRES of
hepatitis A virus or hepatitis C virus in BS-C-1 cells and Huh-7 cells (37- to 44
fold increase and 5 to 5.3-fold increase, respectively). Since PTB had no
quantitative or qualitative effect on transcription from these plasmids, we
conclude that PTB stimulates translation of representative picornaviral and
flaviviral RNAs in vivo. This is likely to reflect the stabilization of higher
ordered RNA structures within the IRES and was not observed with PTB mutants
lacking RNA recognition motifs located in the C-terminal third of the molecule.
PMID- 10669737
TI - The phosphorylation status of a cyclic AMP-responsive activator is modulated via
a chromatin-dependent mechanism.
AB - Cyclic AMP (cAMP) stimulates the expression of numerous genes via the protein
kinase A (PKA)-mediated phosphorylation of CREB at Ser133. Ser133
phosphorylation, in turn, promotes recruitment of the coactivator CREB binding
protein and its paralog p300, histone acetyltransferases (HATs) that have been
proposed to mediate target gene activation, in part, by destabilizing promoter
bound nucleosomes and thereby allowing assembly of the transcriptional apparatus.
Here we show that although histone deacetylase (HDAC) inhibitors potentiate
target gene activation via cAMP, they do not stimulate transcription over the
early burst phase, during which CREB phosphorylation and CBP/p300 recruitment are
maximal. Rather, HDAC inhibitors augment CREB activity during the late
attenuation phase by prolonging CREB phosphorylation on chromosomal but,
remarkably, not on extrachromosomal templates. In reconstitution studies,
assembly of periodic nucleosomal arrays on a cAMP-responsive promoter template
potently inhibited CREB phosphorylation by PKA, and acetylation of these template
bound nucleosomes by p300 partially rescued CREB phosphorylation by PKA. Our
results suggest a novel regulatory mechanism by which cellular HATs and HDACs
modulate the phosphorylation status of nuclear activators in response to cellular
signals.
PMID- 10669738
TI - The putative pore-forming domain of Bax regulates mitochondrial localization and
interaction with Bcl-X(L).
AB - Bax is a proapoptotic member of the Bcl-2 family of proteins which localizes to
and uses mitochondria as its major site of action. Bax normally resides in the
cytoplasm and translocates to mitochondria in response to apoptotic stimuli, and
it promotes apoptosis in two ways: (i) by disrupting mitochondrial membrane
barrier function by formation of ion-permeable pores in mitochondrial membranes
and (ii) by binding to antiapoptotic Bcl-2 family proteins via its BH3 domain and
inhibiting their functions. A hairpin pair of amphipathic alpha-helices (alpha5
alpha6) in Bax has been predicted to participate in membrane insertion and pore
formation by Bax. We mutagenized several charged residues in the alpha5-alpha6
domain of Bax, changing them to alanine. These substitution mutants of Bax
constitutively localized to mitochondria and displayed a gain-of-function
phenotype when expressed in mammalian cells. Furthermore, substitution of 8 out
of 10 charged residues in the alpha5-alpha6 domain of Bax resulted in a loss of
cytotoxicity in yeast but a gain-of-function phenotype in mammalian cells. The
enhanced function of this Bax mutant was correlated with increased binding to Bcl
X(L), through a BH3-independent mechanism. These observations reveal new
functions for the alpha5-alpha6 hairpin loop of Bax: (i) regulation of
mitochondrial targeting and (ii) modulation of binding to antiapoptotic Bcl-2
proteins.
PMID- 10669739
TI - Cubitus interruptus requires Drosophila CREB-binding protein to activate wingless
expression in the Drosophila embryo.
AB - CREB-binding protein (CBP) serves as a transcriptional coactivator in multiple
signal transduction pathways. The Drosophila homologue of CBP, dCBP, interacts
with the transcription factors Cubitus interruptus (CI), MAD, and Dorsal (DL) and
functions as a coactivator in several signaling pathways during Drosophila
development, including the hedgehog (hh), decapentaplegic (dpp), and Toll
pathways. Although dCBP is required for the expression of the hh target genes,
wingless (wg) and patched (ptc) in vivo, and potentiates ci-mediated
transcriptional activation in vitro, it is not known that ci absolutely requires
dCBP for its activity. We used a yeast genetic screen to identify several ci
point mutations that disrupt CI-dCBP interactions. These mutant proteins are
unable to transactivate a reporter gene regulated by ci binding sites and have a
lower dCBP-stimulated activity than wild-type CI. When expressed exogenously in
embryos, the CI point mutants cannot activate endogenous wg expression.
Furthermore, a CI mutant protein that lacks the entire dCBP interaction domain
functions as a negative competitor for wild-type CI activity, and the expression
of dCBP antisense RNAs can suppress CI transactivation in Kc cells. Taken
together, our data suggest that dCBP function is necessary for ci-mediated
transactivation of wg during Drosophila embryogenesis.
PMID- 10669741
TI - Two novel Drosophila TAF(II)s have homology with human TAF(II)30 and are
differentially regulated during development.
AB - TFIID is a multiprotein complex composed of the TATA binding protein (TBP) and
TBP-associated factors (TAF(II)s). The binding of TFIID to the promoter is the
first step of RNA polymerase II preinitiation complex assembly on protein-coding
genes. Yeast (y) and human (h) TFIID complexes contain 10 to 13 TAF(II)s.
Biochemical studies suggested that the Drosophila (d) TFIID complexes contain
only eight TAF(II)s, leaving a number of yeast and human TAF(II)s (e.g.,
hTAF(II)55, hTAF(II)30, and hTAF(II)18) without known Drosophila homologues. We
demonstrate that Drosophila has not one but two hTAF(II)30 homologues, dTAF(II)16
and dTAF(II)24, which are encoded by two adjacent genes. These two genes are
localized in a head-to-head orientation, and their 5' extremities overlap. We
show that these novel dTAF(II)s are expressed and that they are both associated
with TBP and other bona fide dTAF(II)s in dTFIID complexes. dTAF(II)24, but not
dTAF(II)16, was also found to be associated with the histone acetyltransferase
(HAT) dGCN5. Thus, dTAF(II)16 and dTAF(II)24 are functional homologues of
hTAF(II)30, and this is the first demonstration that a TAF(II)-GCN5-HAT complex
exists in Drosophila. The two dTAF(II)s are differentially expressed during
embryogenesis and can be detected in both nuclei and cytoplasm of the cells.
These results together indicate that dTAF(II)16 and dTAF(II)24 may have similar
but not identical functions.
PMID- 10669740
TI - Akt suppresses apoptosis by stimulating the transactivation potential of the
RelA/p65 subunit of NF-kappaB.
AB - It is well established that cell survival signals stimulated by growth factors,
cytokines, and oncoproteins are initiated by phosphoinositide 3-kinase (PI3K)-
and Akt-dependent signal transduction pathways. Oncogenic Ras, an upstream
activator of Akt, requires NF-kappaB to initiate transformation, at least
partially through the ability of NF-kappaB to suppress transformation-associated
apoptosis. In this study, we show that oncogenic H-Ras requires PI3K and Akt to
stimulate the transcriptional activity of NF-kappaB. Activated forms of H-Ras and
MEKK stimulate signals that result in nuclear translocation and DNA binding of NF
kappaB as well as stimulation of the NF-kappaB transactivation potential. In
contrast, activated PI3K or Akt stimulates NF-kappaB-dependent transcription by
stimulating transactivation domain 1 of the p65 subunit rather than inducing NF
kappaB nuclear translocation via IkappaB degradation. Inhibition of IkappaB
kinase (IKK), using an IKKbeta dominant negative protein, demonstrated that
activated Akt requires IKK to efficiently stimulate the transactivation domain of
the p65 subunit of NF-kappaB. Inhibition of endogenous Akt activity sensitized
cells to H-Ras(V12)-induced apoptosis, which was associated with a loss of NF
kappaB transcriptional activity. Finally, Akt-transformed cells were shown to
require NF-kappaB to suppress the ability of etoposide to induce apoptosis. Our
work demonstrates that, unlike activated Ras, which can stimulate parallel
pathways to activate both DNA binding and the transcriptional activity of NF
kappaB, Akt stimulates NF-kappaB predominantly by upregulating of the
transactivation potential of p65.
PMID- 10669742
TI - CIZ, a zinc finger protein that interacts with p130(cas) and activates the
expression of matrix metalloproteinases.
AB - p130(cas) (Cas) is a docking protein that contains an SH3 domain and multiple
tyrosine residues. p130(cas) is located at focal adhesions, is tyrosine
phosphorylated in response to integrin stimulation, and is thought to transmit
signals, via c-Crk and other proteins, for the remodeling of actin stress fibers
and cell movement. In a search for the ligands of the SH3 domain of p130(cas) by
far-Western screening, we cloned a novel protein named CIZ (for Cas-interacting
zinc finger protein). CIZ consists of the following: a putative leucine zipper; a
serine/threonine-rich region; a proline-rich sequence; five, six, or eight
Kruppel-type C(2)H(2) zinc fingers; and the glutamine-alanine repeat. CIZ binds
Cas in cells and is located in the nucleus and at focal adhesions. We showed that
CIZ is a nucleocytoplasmic shuttling protein, by using the transient interspecies
heterokaryon formation assay. In order to search for the targets of CIZ in
nucleus, we determined the DNA binding consensus of CIZ as (G/C)AAAAA(A) by
cyclic amplification and selection of targets analysis. The consensus-like
sequences are found in several promoters of matrix metalloproteinases (MMPs),
which are the enzymes used to degrade the extracellular matrix proteins. CIZ
binds to a consensus-like sequence in the MMP-1 (collagenase) promoter.
Overexpression of CIZ upregulates the transcriptions from MMP-1, MMP-3
(stromelysin), and MMP-7 (matrilysin) promoters, and this transactivation was
enhanced in the presence of Cas. Furthermore, the stable overexpression of CIZ
promoted the production of MMP-7 in culture medium. In summary, CIZ, a novel zinc
finger protein, binds Cas, is a nucleocytoplasmic shuttling protein, and
regulates the expression of MMPs.
PMID- 10669743
TI - Control of human telomere length by TRF1 and TRF2.
AB - Telomere length in human cells is controlled by a homeostasis mechanism that
involves telomerase and the negative regulator of telomere length, TRF1 (TTAGGG
repeat binding factor 1). Here we report that TRF2, a TRF1-related protein
previously implicated in protection of chromosome ends, is a second negative
regulator of telomere length. Overexpression of TRF2 results in the progressive
shortening of telomere length, similar to the phenotype observed with TRF1.
However, while induction of TRF1 could be maintained over more than 300
population doublings and resulted in stable, short telomeres, the expression of
exogenous TRF2 was extinguished and the telomeres eventually regained their
original length. Consistent with their role in measuring telomere length,
indirect immunofluorescence indicated that both TRF1 and TRF2 bind to duplex
telomeric DNA in vivo and are more abundant on telomeres with long TTAGGG repeat
tracts. Neither TRF1 nor TRF2 affected the expression level of telomerase.
Furthermore, the presence of TRF1 or TRF2 on a short linear telomerase substrate
did not inhibit the enzymatic activity of telomerase in vitro. These findings are
consistent with the recently proposed t loop model of telomere length homeostasis
in which telomerase-dependent telomere elongation is blocked by sequestration of
the 3' telomere terminus in TRF1- and TRF2-induced telomeric loops.
PMID- 10669744
TI - Sarcospan-deficient mice maintain normal muscle function.
AB - Sarcospan is an integral membrane component of the dystrophin-glycoprotein
complex (DGC) found at the sarcolemma of striated and smooth muscle. The DGC
plays important roles in muscle function and viability as evidenced by defects in
components of the DGC, which cause muscular dystrophy. Sarcospan is unique among
the components of the complex in that it contains four transmembrane domains with
intracellular N- and C-terminal domains and is a member of the tetraspan
superfamily of proteins. Sarcospan is tightly linked to the sarcoglycans, and
together these proteins form a subcomplex within the DGC. Stable expression of
sarcospan at the sarcolemma is dependent upon expression of the sarcoglycans.
Here we describe the generation and analysis of mice carrying a null mutation in
the Sspn gene. Surprisingly, the Sspn-deficient muscle maintains expression of
other components of the DGC at the sarcolemma, and no gross histological
abnormalities of muscle from the mice are observed. The Sspn-deficient muscle
maintains sarcolemmal integrity as determined by serum creatine kinase and Evans
blue uptake assays, and the Sspn-deficient muscle maintains normal force and
power generation capabilities. These data suggest either that sarcospan is not
required for normal DGC function or that the Sspn-deficient muscle is
compensating for the absence of sarcospan, perhaps by utilizing another protein
to carry out its function.
PMID- 10669745
TI - Tyrosine phosphorylation mediates both activation and downmodulation of the
biological activity of Vav.
AB - Vav works as a GDP/GTP exchange factor for Rac GTPases, thereby facilitating the
transition of these proteins from the inactive (GDP-bound) into the active (GTP
bound) state. The stimulation of Vav exchange activity during cell signaling is
mediated by tyrosine phosphorylation. To understand the roles of phosphorylation
in the regulation of Vav activity, we have initiated the characterization of the
residues of Vav that are phosphorylated during signal transduction. Here we show
that a Y-to-F mutation in one of these residues, Y174, leads to the oncogenic
activation of Vav and to the enhancement of other Vav-mediated signals such as
those for cytoskeletal reorganization, JNK activation, and stimulation of the
nuclear factor of activated T cells. The effect induced by the Y174F mutation is
further accentuated by mutations in residue Y142 or Y160. The Y174F mutation has
no effect on the exchange activity of Vav in vitro but results in higher levels
of phosphorylation in vivo. Using a phosphospecific antibody, we found that Y174
is phosphorylated following stimulation of mitogenic and antigenic receptors.
This phosphorylation event is conserved in Vav-2 and Vav-3, the other two members
of the Vav family. These results identify a previously unknown mechanism for the
oncogenic activation of Vav and suggest that the activity of this exchange factor
is modulated by two antagonistic phosphorylation events, one involved in Vav
activation and a second one implicated in Vav inactivation.
PMID- 10669746
TI - Inhibition of IkappaB kinase and IkappaB phosphorylation by 15-deoxy-Delta(12,14)
prostaglandin J(2) in activated murine macrophages.
AB - Activation of the macrophage cell line RAW 264.7 with lipopolysaccharide (LPS)
and gamma interferon (IFN-gamma) induces the expression of gene products involved
in host defense, among them type 2 nitric oxide synthase. Treatment of cells with
15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)) inhibited the LPS- and IFN
gamma-dependent synthesis of NO, a process that was not antagonized by similar
concentrations of prostaglandin J(2), prostaglandin E(2), or rosiglitazone, a
peroxisomal proliferator-activated receptor gamma ligand. Incubation of activated
macrophages with 15dPGJ(2) inhibited the degradation of IkappaBalpha and
IkappaBbeta and increased their levels in the nuclei. NF-kappaB activity, as well
as the transcription of NF-kappaB-dependent genes, such as those encoding type 2
nitric oxide synthase and cyclooxygenase 2, was impaired under these conditions.
Analysis of the steps leading to IkappaB phosphorylation showed an inhibition of
IkappaB kinase by 15dPGJ(2) in cells treated with LPS and IFN-gamma, resulting in
an impaired phosphorylation of IkappaBalpha, at least in the serine 32 residue
required for targeting and degradation of this protein. Incubation of partially
purified activated IkappaB kinase with 2 microM 15dPGJ(2) reduced by 83% the
phosphorylation in serine 32 of IkappaBalpha, suggesting that this prostaglandin
exerts direct inhibitory effects on the activity of the IkappaB kinase complex.
These results show rapid actions of 15dPGJ(2), independent of peroxisomal
proliferator receptor gamma activation, in macrophages challenged with low doses
of LPS and IFN-gamma.
PMID- 10669747
TI - Cloning and characterization of SCHIP-1, a novel protein interacting specifically
with spliced isoforms and naturally occurring mutant NF2 proteins.
AB - The neurofibromatosis type 2 (NF2) protein, known as schwannomin or merlin, is a
tumor suppressor involved in NF2-associated and sporadic schwannomas and
meningiomas. It is closely related to the ezrin-radixin-moesin family members,
implicated in linking membrane proteins to the cytoskeleton. The molecular
mechanism allowing schwannomin to function as a tumor suppressor is unknown. In
attempt to shed light on schwannomin function, we have identified a novel coiled
coil protein, SCHIP-1, that specifically associates with schwannomin in vitro and
in vivo. Within its coiled-coil region, this protein is homologous to human FEZ
proteins and the related Caenorhabditis elegans gene product UNC-76.
Immunofluorescent staining of transiently transfected cells shows a partial
colocalization of SCHIP-1 and schwannomin, beneath the cytoplasmic membrane.
Surprisingly, immunoprecipitation assays reveal that in a cellular context,
association with SCHIP-1 can be observed only with some naturally occurring
mutants of schwannomin, or a schwannomin spliced isoform lacking exons 2 and 3,
but not with the schwannomin isoform exhibiting growth-suppressive activity. Our
observations suggest that SCHIP-1 interaction with schwannomin is regulated by
conformational changes in schwannomin, possibly induced by posttranslational
modifications, alternative splicing, or mutations.
PMID- 10669748
TI - Inhibition of c-Jun N-terminal kinase 2 expression suppresses growth and induces
apoptosis of human tumor cells in a p53-dependent manner.
AB - c-Jun N-terminal kinase (JNK) plays a critical role in coordinating the cellular
response to stress and has been implicated in regulating cell growth and
transformation. To investigate the growth-regulatory functions of JNK1 and JNK2,
we used specific antisense oligonucleotides (AS) to inhibit their expression. A
survey of several human tumor cell lines revealed that JNKAS treatment markedly
inhibited the growth of cells with mutant p53 status but not that of cells with
normal p53 function. To further examine the influence of p53 on cell sensitivity
to JNKAS treatment, we compared the responsiveness of RKO, MCF-7, and HCT116
cells with normal p53 function to that of RKO E6, MCF-7 E6, and HCT116 p53(-/-),
which were rendered p53 deficient by different methods. Inhibition of JNK2 (and
to a lesser extent JNK1) expression dramatically reduced the growth of p53
deficient cells but not that of their normal counterparts. JNK2AS-induced growth
inhibition was correlated with significant apoptosis. JNK2AS treatment induced
the expression of the cyclin-dependent kinase inhibitor p21(Cip1/Waf1) in
parental MCF-7, RKO, and HCT116 cells but not in the p53-deficient derivatives.
That p21(Cip1/Waf1) expression contributes to the survival of JNK2AS-treated
cells was supported by additional experiments demonstrating that p21(Cip1/Waf1)
deficiency in HCT116 cells also results in heightened sensitivity to JNKAS
treatment. Our results indicate that perturbation of JNK2 expression adversely
affects the growth of otherwise nonstressed cells. p53 and its downstream
effector p21(Cip1/Waf1) are important in counteracting these detrimental effects
and promoting cell survival.
PMID- 10669749
TI - Overexpression of kinase-associated phosphatase (KAP) in breast and prostate
cancer and inhibition of the transformed phenotype by antisense KAP expression.
AB - Accumulating evidence suggests that phosphatases play an important role in
regulating a variety of signal transduction pathways that have a bearing on
cancer. The kinase-associated phosphatase (KAP) is a human dual-specificity
protein phosphatase that was identified as a Cdc2- or Cdk2-interacting protein by
a yeast two-hybrid screening, yet the biological significance of these
interactions remains elusive. We have identified the KAP gene as an overexpressed
gene in breast and prostate cancer by using a phosphatase domain-specific
differential-display PCR strategy. Here we report that breast and prostate
malignancies are associated with high levels of KAP expression. The
sublocalization of KAP is variable. In normal cells, KAP is primarily found in
the perinuclear region, but in tumor cells, a significant portion of KAP is found
in the cytoplasm. Blocking KAP expression by antisense KAP in a tetracycline
regulatable system results in a reduced population of S-phase cells and reduced
Cdk2 kinase activity. Furthermore, lowering KAP expression led to inhibition of
the transformed phenotype, with reduced anchorage-independent growth and
tumorigenic potential in athymic nude mice. These findings suggest that
therapeutic intervention might be aimed at repression of KAP gene overexpression
in human breast and prostate cancer.
PMID- 10669750
TI - A combinatorial code for gene expression generated by transcription factor Bach2
and MAZR (MAZ-related factor) through the BTB/POZ domain.
AB - Bach2 is a B-cell- and neuron-specific transcription repressor that forms
heterodimers with the Maf-related oncoproteins. We show here that Bach2 activates
transcription by interacting with its novel partner MAZR. MAZR was isolated by
the yeast two-hybrid screen using the BTB/POZ domain of Bach2 as bait. Besides
the BTB/POZ domain, MAZR possesses Zn finger motifs that are closely related to
those of the Myc-associated Zn finger (MAZ) protein. MAZR mRNA was coexpressed
with Bach2 in B cells among hematopoietic cells and in developing mouse limb
buds, suggesting a cooperative role for MAZR and Bach2 in these cells. MAZR forms
homo- and hetero-oligomers with Bach2 through the BTB domain, which oligomers
bind to guanine-rich sequences. Unlike MAZ, MAZR functioned as a strong activator
of the c-myc promoter in transfection assays with B cells. However, it does not
possess a typical activation domain, suggesting a role for it as an unusual type
of transactivator. The fgf4 gene, which regulates morphogenesis of limb buds,
contains both guanine-rich sequences and a Bach2 binding site in its regulatory
region. In transfection assays using fibroblast cells, the fgf4 gene was
upregulated in the presence of both MAZR and Bach2 in a BTB/POZ domain-dependent
manner. The results provide a new perspective on the function of BTB/POZ domain
factors and indicate that BTB/POZ domain-mediated oligomers of transcription
factors may serve as combinatorial codes for gene expression.
PMID- 10669751
TI - Multiple mitogen-activated protein kinase signaling pathways connect the cot
oncoprotein to the c-jun promoter and to cellular transformation.
AB - The serine/threonine kinase Cot is a member of the mitogen-activated protein
kinase (MAPK) kinase kinase family implicated in cellular transformation.
Enhanced expression of this protein has been shown to activate both the MAPK and
the c-Jun N-terminal kinase (JNK) pathways and to stimulate the nuclear factor of
activated T cells and NF-kappaB-dependent transcription. However, the nature of
the normal functions of the Cot protein and the molecular mechanisms responsible
for its oncogenic potential are still largely unknown. Here, we show that
overexpression of the cot proto-oncogene is sufficient to stimulate the
expression of c-jun and that, in turn, the activity of c-Jun is required for Cot
induced transformation. These observations prompted us to explore the molecular
events by which Cot regulates c-jun expression. We found that Cot potently
stimulates the activity of the c-jun promoter utilizing JNK-dependent and
independent pathways, the latter involving two novel members of the MAPK family,
p38gamma (ERK6) and ERK5. Molecularly, this activity was found to be dependent on
the ability of Cot to activate, in vivo, members of each class of the MAPK kinase
superfamily, including MEK, SEK, MKK6, and MEK5. Furthermore, the use of dominant
interfering molecules revealed that Cot requires JNK, p38s, and ERK5 to stimulate
the c-jun promoter fully and to induce neoplastic transformation. These findings
indicate that Cot represents the first example of a serine/threonine kinase
acting simultaneously on all known MAPK cascades. Moreover, these observations
strongly suggest that the transforming ability of Cot results from the
coordinated activation of these pathways, which ultimately converge on the
regulation of the expression and activity of the product of the c-jun proto
oncogene.
PMID- 10669752
TI - Sequential requirements of the N-terminal palmitoylation site and SH2 domain of
Src family kinases in the initiation and progression of FcepsilonRI signaling.
AB - Initial biochemical signaling originating from high-affinity immunoglobulin E
receptor (FcepsilonRI) has been ascribed to Src family kinases. To understand the
mechanisms by which individual kinases drive the signaling, we conducted
reconstitution experiments: FcepsilonRI signaling in RBL2H3 cells was first
suppressed by a membrane-anchored, gain-of-function C-terminal Src kinase and
then reconstructed with Src family kinases whose C-terminal negative regulatory
sequence was replaced with a c-myc epitope. Those constructs derived from Lyn and
Fyn, which are associated with detergent-resistant membranes (DRMs), physically
interacted with resting FcepsilonRI and reconstructed clustering-induced
signaling that leads to calcium mobilization and ERK1 and -2 activation. c-Src
derived construct, which was excluded from DRMs, failed to interact with
FcepsilonRI and to restore the signaling, whereas creation of palmitoylatable
Cys3 enabled it to interact with DRMs and with FcepsilonRI and to restore the
signaling. Deletion of Src homology 3 (SH3) domain from the Lyn-derived construct
did not alter its ability to transduce the series of signaling. Deletion of SH2
domain did not affect its association with DRMs and with FcepsilonRI nor
clustering-induced tyrosine phosphorylation of FcepsilonRI beta and gamma
subunits, but it almost abrogated the next step of tyrosine phosphorylation of
Syk and its recruitment to FcepsilonRI. These findings suggest that Lyn and Fyn
could, but c-Src could not, drive FcepsilonRI signaling and that N-terminal
palmitoylation and SH2 domain are required in sequence for the initial
interaction with FcepsilonRI and for the signal progression to the molecular
assembly.
PMID- 10669753
TI - Mouse A6/twinfilin is an actin monomer-binding protein that localizes to the
regions of rapid actin dynamics.
AB - In our database searches, we have identified mammalian homologues of yeast actin
binding protein, twinfilin. Previous studies suggested that these mammalian
proteins were tyrosine kinases, and therefore they were named A6 protein tyrosine
kinase. In contrast to these earlier studies, we did not find any tyrosine kinase
activity in our recombinant protein. However, biochemical analysis showed that
mouse A6/twinfilin forms a complex with actin monomer and prevents actin filament
assembly in vitro. A6/twinfilin mRNA is expressed in most adult tissues but not
in skeletal muscle and spleen. In mouse cells, A6/twinfilin protein is
concentrated to the areas at the cell cortex which overlap with G-actin-rich
actin structures. A6/twinfilin also colocalizes with the activated forms of small
GTPases Rac1 and Cdc42 to membrane ruffles and to cell-cell contacts,
respectively. Furthermore, expression of the activated Rac1(V12) in NIH 3T3 cells
leads to an increased A6/twinfilin localization to nucleus and cell cortex,
whereas a dominant negative form of Rac1(V12,N17) induces A6/twinfilin
localization to cytoplasm. Taken together, these studies show that mouse
A6/twinfilin is an actin monomer-binding protein whose localization to cortical G
actin-rich structures may be regulated by the small GTPase Rac1.
PMID- 10669754
TI - Sequestration and inhibition of Daxx-mediated transcriptional repression by PML.
AB - PML fuses with retinoic acid receptor alpha (RARalpha) in the t(15;17)
translocation that causes acute promyelocytic leukemia (APL). In addition to
localizing diffusely throughout the nucleoplasm, PML mainly resides in discrete
nuclear structures known as PML oncogenic domains (PODs), which are disrupted in
APL and spinocellular ataxia cells. We isolated the Fas-binding protein Daxx as a
PML-interacting protein in a yeast two-hybrid screen. Biochemical and
immunofluorescence analyses reveal that Daxx is a nuclear protein that interacts
and colocalizes with PML in the PODs. Reporter gene assay shows that Daxx
drastically represses basal transcription, likely by recruiting histone
deacetylases. PML, but not its oncogenic fusion PML-RARalpha, inhibits the
repressor function of Daxx. In addition, SUMO-1 modification of PML is required
for sequestration of Daxx to the PODs and for efficient inhibition of Daxx
mediated transcriptional repression. Consistently, Daxx is found at condensed
chromatin in cells that lack PML. These data suggest that Daxx is a novel nuclear
protein bearing transcriptional repressor activity that may be regulated by
interaction with PML.
PMID- 10669755
TI - Arrest of G(1)-S progression by the p53-inducible gene PC3 is Rb dependent and
relies on the inhibition of cyclin D1 transcription.
AB - The p53-inducible gene PC3 (TIS21, BTG2) is endowed with antiproliferative
activity. Here we report that expression of PC3 in cycling cells induced
accumulation of hypophosphorylated, growth-inhibitory forms of pRb and led to
G(1) arrest. This latter was not observed in cells with genetic disruption of the
Rb gene, indicating that the PC3-mediated G(1) arrest was Rb dependent.
Furthermore, (i) the arrest of G(1)-S transition exerted by PC3 was completely
rescued by coexpression of cyclin D1 but not by that of cyclin A or E; (ii)
expression of PC3 caused a significant down-regulation of cyclin D1 protein
levels, also in Rb-defective cells, accompanied by inhibition of CDK4 activity in
vivo; and (iii) the removal from the PC3 molecule of residues 50 to 68, a
conserved domain of the PC3/BTG/Tob gene family, which we term GR, led to a loss
of the inhibition of proliferation as well as of the down-regulation of cyclin D1
levels. These data point to cyclin D1 down-regulation as the main factor
responsible for the growth inhibition by PC3. Such an effect was associated with
a decrease of cyclin D1 transcript and of cyclin D1 promoter activity, whereas no
effect of PC3 was observed on cyclin D1 protein stability. Taken together, these
findings indicate that PC3 impairs G(1)-S transition by inhibiting pRb function
in consequence of a reduction of cyclin D1 levels and that PC3 acts, either
directly or indirectly, as a transcriptional regulator of cyclin D1.
PMID- 10669756
TI - A DNA helicase required for maintenance of the functional mitochondrial genome in
Saccharomyces cerevisiae.
AB - A novel DNA helicase, a homolog of several prokaryotic helicases, including
Escherichia coli Rep and UvrD proteins, is encoded by the Saccharomyces
cerevisiae nuclear genome open reading frame YOL095c on the chromosome XV. Our
data demonstrate that the helicase is localized in the yeast mitochondria and is
loosely associated with the mitochondrial inner membrane during biochemical
fractionation. The sequence of the C-terminal end of the 80-kDa helicase protein
is similar to a typical N-terminal mitochondrial targeting signal; deletions and
point mutations in this region abolish transport of the protein into
mitochondria. The C-terminal signal sequence of the helicase targets a
heterologous carrier protein into mitochondria in vivo. The purified recombinant
protein can unwind duplex DNA molecules in an ATP-dependent manner. The helicase
is required for the maintenance of the functional ([rho(+)]) mitochondrial genome
on both fermentable and nonfermentable carbon sources. However, the helicase is
not essential for the maintenance of several defective ([rho(-)]) mitochondrial
genomes. We also demonstrate that the helicase is not required for transcription
in mitochondria.
PMID- 10669757
TI - Calcium depletion dissociates and activates heterodimeric notch receptors.
AB - Notch receptors participate in a highly conserved signaling pathway that
regulates morphogenesis in multicellular animals. Maturation of Notch receptors
requires the proteolytic cleavage of a single precursor polypeptide to produce a
heterodimer composed of a ligand-binding extracellular domain (N(EC)) and a
single-pass transmembrane signaling domain (N(TM)). Notch signaling has been
correlated with additional ligand-induced proteolytic cleavages, as well as with
nuclear translocation of the intracellular portion of N(TM) (N(ICD)). In the
current work, we show that the N(EC) and N(TM) subunits of Drosophila Notch and
human Notch1 (hN1) interact noncovalently. N(EC)-N(TM) interaction was disrupted
by 0.1% sodium dodecyl sulfate or divalent cation chelators such as EDTA, and
stabilized by millimolar Ca(2+). Deletion of the Ca(2+)-binding Lin12-Notch (LN)
repeats from the N(EC) subunit resulted in spontaneous shedding of N(EC) into
conditioned medium, implying that the LN repeats are important in maintaining the
interaction of N(EC) and N(TM). The functional consequences of EDTA-induced N(EC)
dissociation were studied by using hN1-expressing NIH 3T3 cells. Treatment of
these cells for 10 to 15 min with 0.5 to 10 mM EDTA resulted in the rapid
shedding of N(EC), the transient appearance of a polypeptide of the expected size
of N(ICD), increased intranuclear anti-Notch1 staining, and the transient
activation of an Notch-sensitive reporter gene. EDTA treatment of HeLa cells
expressing endogenous Notch1 also stimulated reporter gene activity to a degree
equivalent to that resulting from exposure of the cells to the ligand Delta1.
These findings indicate that receptor activation can occur as a consequence of
N(EC) dissociation, which relieves inhibition of the intrinsically active N(TM)
subunit.
PMID- 10669758
TI - The neuron-enriched splicing pattern of Drosophila erect wing is dependent on the
presence of ELAV protein.
AB - Although the Drosophila melanogaster erect wing (ewg) gene is broadly transcribed
in adults, an unusual posttranscriptional regulation involving alternative and
inefficient splicing generates a 116-kDa EWG protein in neurons, while protein
expression elsewhere or of other isoforms is below detection at this stage. This
posttranscriptional control is important, as broad expression of EWG can be
lethal. In this paper, we show that ELAV, a neuron-specific RNA binding protein,
is necessary to regulate EWG protein expression in ELAV-null eye imaginal disc
clones and that ELAV is sufficient for EWG expression in wing disc imaginal
tissue after ectopic expression. Further, analysis of EWG expression elicited
from intron-containing genomic transgenes and cDNA minitransgenes in ELAV
deficient eye discs shows that this regulation is dependent on the presence of
ewg introns. Analyses of the ewg splicing patterns in wild-type and ELAV
deficient eye imaginal discs and in wild-type and ectopic ELAV-expressing wing
imaginal discs, show that certain neuronal splice isoforms correspond to ELAV
levels. The data presented in this paper are consistent with a mechanism in which
ELAV increases the splicing efficiency of ewg transcripts in alternatively
spliced regions rather than with a mechanism in which stability of specific
splice forms is enhanced by ELAV. Additionally, we report that ELAV promotes a
neuron-enriched splice isoform of Drosophila armadillo transcript. ELAV, however,
is not involved in all neuron-enriched splice events.
PMID- 10669759
TI - Molecular cloning of apobec-1 complementation factor, a novel RNA-binding protein
involved in the editing of apolipoprotein B mRNA.
AB - The C-to-U editing of apolipoprotein B (apo-B) mRNA is catalyzed by a
multiprotein complex that recognizes an 11-nucleotide mooring sequence downstream
of the editing site. The catalytic subunit of the editing enzyme, apobec-1, has
cytidine deaminase activity but requires additional unidentified proteins to edit
apo-B mRNA. We purified a 65-kDa protein that functionally complements apobec-1
and obtained peptide sequence information which was used in molecular cloning
experiments. The apobec-1 complementation factor (ACF) cDNA encodes a novel 64.3
kDa protein that contains three nonidentical RNA recognition motifs. ACF and
apobec-1 comprise the minimal protein requirements for apo-B mRNA editing in
vitro. By UV cross-linking and immunoprecipitation, we show that ACF binds to apo
B mRNA in vitro and in vivo. Cross-linking of ACF is not competed by RNAs with
mutations in the mooring sequence. Coimmunoprecipitation experiments identified
an ACF-apobec-1 complex in transfected cells. Immunodepletion of ACF from rat
liver extracts abolished editing activity. The immunoprecipitated complexes
contained a functional holoenzyme. Our results support a model of the editing
enzyme in which ACF binds to the mooring sequence in apo-B mRNA and docks apobec
1 to deaminate its target cytidine. The fact that ACF is widely expressed in
human tissues that lack apobec-1 and apo-B mRNA suggests that ACF may be involved
in other RNA editing or RNA processing events.
PMID- 10669760
TI - Mouse Zac1, a transcriptional coactivator and repressor for nuclear receptors.
AB - Transcriptional activation by nuclear hormone receptors is mediated by the 160
kDa family of nuclear receptor coactivators. These coactivators associate with
DNA-bound nuclear receptors and transmit activating signals to the transcription
machinery through two activation domains. In screening for mammalian proteins
that bind the C-terminal activation domain of the nuclear receptor coactivator
GRIP1, we identified a new variant of mouse Zac1 which we call mZac1b. Zac1 was
previously discovered as a putative transcriptional activator involved in
regulation of apoptosis and the cell cycle. In yeast two-hybrid assays and in
vitro, mZac1b bound to GRIP1, to CREB-binding protein (CBP) and p300 (which are
coactivators for nuclear receptors and other transcriptional activators), and to
nuclear receptors themselves in a hormone-independent manner. In transient
transfection assays mZac1b exhibited a transcriptional activation activity when
fused with the Gal4 DNA binding domain, and it enhanced transcriptional
activation by the Gal4 DNA binding domain fused to GRIP1 or CBP fragments. More
importantly, mZac1b was a powerful coactivator for the hormone-dependent activity
of nuclear receptors, including androgen, estrogen, glucocorticoid, and thyroid
hormone receptors. However, with some reporter genes and in some cell lines
mZac1b acted as a repressor rather than a coactivator of nuclear receptor
activity. Thus, mZac1b can interact with nuclear receptors and their coactivators
and play both positive and negative roles in regulating nuclear receptor
function.
PMID- 10669761
TI - The coactivator PGC-1 cooperates with peroxisome proliferator-activated receptor
alpha in transcriptional control of nuclear genes encoding mitochondrial fatty
acid oxidation enzymes.
AB - Peroxisome proliferator-activated receptor alpha (PPARalpha) plays a key role in
the transcriptional control of genes encoding mitochondrial fatty acid beta
oxidation (FAO) enzymes. In this study we sought to determine whether the
recently identified PPAR gamma coactivator 1 (PGC-1) is capable of coactivating
PPARalpha in the transcriptional control of genes encoding FAO enzymes. Mammalian
cell cotransfection experiments demonstrated that PGC-1 enhanced PPARalpha
mediated transcriptional activation of reporter plasmids containing PPARalpha
target elements. PGC-1 also enhanced the transactivation activity of a PPARalpha
Gal4 DNA binding domain fusion protein. Retroviral vector-mediated expression
studies performed in 3T3-L1 cells demonstrated that PPARalpha and PGC-1
cooperatively induced the expression of PPARalpha target genes and increased
cellular palmitate oxidation rates. Glutathione S-transferase "pulldown" studies
revealed that in contrast to the previously reported ligand-independent
interaction with PPARgamma, PGC-1 binds PPARalpha in a ligand-influenced manner.
Protein-protein interaction studies and mammalian cell hybrid experiments
demonstrated that the PGC-1-PPARalpha interaction involves an LXXLL domain in PGC
1 and the PPARalpha AF2 region, consistent with the observed ligand influence.
Last, the PGC-1 transactivation domain was mapped to within the NH(2)-terminal
120 amino acids of the PGC-1 molecule, a region distinct from the PPARalpha
interacting domains. These results identify PGC-1 as a coactivator of PPARalpha
in the transcriptional control of mitochondrial FAO capacity, define separable
PPARalpha interaction and transactivation domains within the PGC-1 molecule, and
demonstrate that certain features of the PPARalpha-PGC-1 interaction are distinct
from that of PPARgamma-PGC-1.
PMID- 10669762
TI - The BIR motifs mediate dominant interference and oligomerization of inhibitor of
apoptosis Op-IAP.
AB - The defining structural motif of the inhibitor of apoptosis (iap) protein family
is the BIR (baculovirus iap repeat), a highly conserved zinc coordination domain
of approximately 70 residues. Although the BIR is required for inhibitor-of
apoptosis (IAP) function, including caspase inhibition, its molecular role in
antiapoptotic activity in vivo is unknown. To define the function of the BIRs, we
investigated the activity of these structural motifs within Op-IAP, an efficient,
virus-derived IAP. We report here that Op-IAP(1-216), a loss-of-function
truncation which contains two BIRs but lacks the C-terminal RING motif, potently
interfered with Op-IAP's capacity to block apoptosis induced by diverse stimuli.
In contrast, Op-IAP(1-216) had no effect on apoptotic suppression by caspase
inhibitor P35. Consistent with a mechanism of dominant inhibition that involves
direct interaction between Op-IAP(1-216) and full-length Op-IAP, both proteins
formed an immunoprecipitable complex in vivo. Op-IAP also self-associated. In
contrast, the RING motif-containing truncation Op-IAP(183-268) failed to interact
with or interfere with Op-IAP function. Substitution of conserved residues within
BIR 2 caused loss of dominant inhibition by Op-IAP(1-216) and coincided with loss
of interaction with Op-IAP. Thus, residues encompassing the BIRs mediate dominant
inhibition and oligomerization of Op-IAP. Consistent with dominant interference
by interaction with an endogenous cellular IAP, Op-IAP(1-216) also lowered the
survival threshold of cultured insect cells. Taken together, these data suggest a
new model wherein the antiapoptotic function of IAP requires homo
oligomerization, which in turn mediates specific interactions with cellular
apoptotic effectors.
PMID- 10669763
TI - Posttranslational modification of Bcl-2 facilitates its proteasome-dependent
degradation: molecular characterization of the involved signaling pathway.
AB - The ratio of proapoptotic versus antiapoptotic Bcl-2 members is a critical
determinant that plays a significant role in altering susceptibility to
apoptosis. Therefore, a reduction of antiapoptotic protein levels in response to
proximal signal transduction events may switch on the apoptotic pathway. In
endothelial cells, tumor necrosis factor alpha (TNF-alpha) induces
dephosphorylation and subsequent ubiquitin-dependent degradation of the
antiapoptotic protein Bcl-2. Here, we investigate the role of different putative
phosphorylation sites to facilitate Bcl-2 degradation. Mutation of the consensus
protein kinase B/Akt site or of potential protein kinase C or cyclic AMP
dependent protein kinase sites does not affect Bcl-2 stability. In contrast,
inactivation of the three consensus mitogen-activated protein (MAP) kinase sites
leads to a Bcl-2 protein that is ubiquitinated and subsequently degraded by the
26S proteasome. Inactivation of these sites within Bcl-2 revealed that
dephosphorylation of Ser87 appears to play a major role. A Ser-to-Ala
substitution at this position results in 50% degradation, whereas replacement of
Thr74 with Ala leads to 25% degradation, as assessed by pulse-chase studies. We
further demonstrated that incubation with TNF-alpha induces dephosphorylation of
Ser87 of Bcl-2 in intact cells. Furthermore, MAP kinase triggers phosphorylation
of Bcl-2, whereas a reduction in Bcl-2 phosphorylation was observed in the
presence of MAP kinase-specific phosphatases or the MAP kinase-specific inhibitor
PD98059. Moreover, we show that oxidative stress mediates TNF-alpha-stimulated
proteolytic degradation of Bcl-2 by reducing MAP kinase activity. Taken together,
these results demonstrate a direct protective role for Bcl-2 phosphorylation by
MAP kinase against apoptotic challenges to endothelial cells and other cells.
PMID- 10669764
TI - Insect cells as HLA-restricted antigen-presenting cells for the IFN-gamma elispot
assay.
AB - Measurement of specific cellular immune responses in patients undergoing
immunotherapy is difficult. Established approaches, including cytotoxicity (e.g.,
51Cr release) and cytokine release assays, require in vitro culturing for several
weeks or more of patients' peripheral blood mononuclear cells (PBMC) and the
addition of exogenous cytokines. Therefore, the immunological response does not
reflect in vivo conditions. To address these disadvantages, we have used an
interferon-gamma (IFN-gamma) Elispot assay for detecting peptide-specific CD8(+)
lymphocytes in PBMC. A limitation of this assay is the lack of a reproducible
source of antigen-presenting cells (APCs). Currently available APCs often lead to
significant background levels. It has been shown that transfected insect cells
can express empty MHC class I molecules on their surface. We have transfected
Drosophila melanogaster S2 cells and the Lepidopteran line Sf9 with the gene
encoding human HLA-A2.1. We demonstrate that insect cells expressing a human HLA
molecule effectively function as APCs in the IFN-gamma Elispot assay. Initially
the feasibility of the assay was assessed using CD8(+) T cells from HLA-A2.1(+)
donors with known reactivity against an HLA-A2.1-binding epitope of the influenza
matrix protein. Use of insect cells as APCs abrogated background spots,
increasing sensitivity. We further observed that a short-term prestimulation of
PBMC with peptide-pulsed insect cells markedly enhanced the frequency of peptide
specific T cells that could be measured in the Elispot assay without increasing
the background. This approach was then used to measure CD8(+) T cell reactivity
to a peptide from tyrosinase, an antigen that is processed and presented by
melanoma cells. Insect cells expressing human HLA molecules provide a standard
APC for monitoring CD8(+) T cell responses to tumor and viral peptides during
immunotherapy.
PMID- 10669765
TI - Measurement of T-helper cytokines secreted by cord blood mononuclear cells in
response to allergens.
AB - It has been proposed that in utero factors may predispose towards the development
of childhood atopy. To test this hypothesis, it will be necessary to measure T
helper cell (Th) cytokines secreted by human cord blood mononuclear cells (CBMC)
stimulated by allergens. However, to date, it has proven impossible to measure
allergen-specific CBMC secretion of the key Th cytokine interleukin-4 (IL-4)
using conventional sandwich ELISA techniques. We report for the first time the
successful measurement of IL-4 secreted by CBMC stimulated by the allergens
timothy grass pollen and house dust mite extract. The method is an adaptation of
a novel cell-based ELISA (celELISA), which demonstrated an increased (up to 20
fold) sensitivity to detect IL-4. The method is simple, precise, is no more
costly than a conventional ELISA, and can identify individuals in a general
population whose CBMC exhibit different cytokine biases in response to allergens.
The frequency distribution of IL-4 and interferon-gamma (IFN-gamma) CBMC
responses to allergens in the general population approximates to a log-normal
distribution, which will permit the application of linear regression techniques
in the identification of in utero factors which influence Th bias.
PMID- 10669766
TI - Use of linear and multiple antigenic peptides in the immunodiagnosis of acute
hepatitis A virus infection.
AB - The reactivities of two panels of anti-HAV human sera from geographically
distinct areas (Chile and Spain) to synthetic peptides from the VP1, VP2 and VP3
hepatitis A virus capsid proteins were examined by an enzyme-linked immunosorbent
assay (ELISA) procedure. Two and four branched multiple antigenic peptides (MAPs)
and palmitoylated peptides were compared with free synthetic sequences for the
detection of IgM anti-HAV antibodies in the two panels of human sera. Our results
showed that acute hepatitis A patient sera recognized preferentially homogeneous
two branched MAPs and palmitic acid conjugated peptides. The palmitoyl-derived
VP3(110-121) peptide and the corresponding dimeric MAP were the most sensitive
and appropriate for serological studies of HAV-infected patients by ELISA,
sensitivity and specificity being higher than 90% and 95%, respectively. These
peptide-based tests open up new avenues in the development of peptide-based
immunosorbent assays for the detection of acute HAV disease.
PMID- 10669767
TI - A low budget luminometer for sensitive chemiluminescent immunoassays.
AB - We have designed a simple luminometer based on a reasonably priced Peltier-cooled
charge-coupled device (CCD) camera, housed in a light-tight box, with
straightforward lens imaging and a simple platform for a microtitre or other
assay format. The quantitative readout of the CCD image is recorded on a PC using
customised software. The instrument can be assembled in a standard university
workshop for under pound3000, compared with the cheapest commercial instruments
retailing at pound10,000 and above. Consistent with the general view on
chemiluminescent assays, the sensitivity is 10-100 times greater than that
obtained with parallel ELISA's using a chromogenic substrate. A unique feature of
the CCD format is that it enables assays to be carried out on arrays of minidots
and even nanodots of antigen on the floor of each microtitre well. This permits
direct comparison and standardisation of reactivity of a single sample against
several antigens and economy in the use of reagents, test sample and technician
time; finger-prick samples of blood can be analysed. The instrument should have
widespread applicability in developing countries and, indeed, in any laboratories
with hard-pressed budgets.
PMID- 10669768
TI - Zinc has no effect on IL-3-mediated apoptosis of BAF-3 cells but enhances CD95
mediated apoptosis of jurkat cells.
AB - The feasibility of using a zinc-inducible gene expression system for the study of
apoptosis-controlling genes in BAF-3 murine B cells and Jurkat human T cells was
evaluated. Initially, cell sensitivity to a range of zinc concentrations was
examined. It was found that zinc concentrations above 60 microM were toxic to BAF
3 cells and those above 50 microM were toxic to Jurkat cells. Secondly, the zinc
concentration required to achieve maximal gene expression was examined. BAF-3
cells transiently transfected with the pMTCB6+/luciferase vector were exposed to
zinc concentrations ranging from 0-120 microM, whilst stably transfected Jurkat
cells were exposed to 0-70 microM zinc. At zinc concentrations nontoxic to each
cell type, the maximum induction achieved was 20-fold (at 60 microM) in BAF-3
cells, and 7.5-fold (at 50 microM) in Jurkat cells. Thirdly, the effect of zinc
on apoptosis was examined. It was shown that exposure to nontoxic zinc
concentrations had no effect on IL-3 withdrawal-mediated apoptosis of BAF-3
cells. However, in the case of Jurkat cells, pre-exposure to zinc augmented CD95
mediated apoptosis. These results illustrate the importance of characterizing
individual cell lines when using zinc-inducible gene expression systems.
PMID- 10669769
TI - Development of a new method for the determination of immune responses in the
human stomach.
AB - The discovery of the gastric pathogen Helicobacter pylori has created a need for
accurate methods to study immune responses locally in the human stomach.
Therefore, we have developed a quick and easy method for extraction of antibodies
from gastric biopsies using saponin and compared this method with the more
laborious analysis of antibody-secreting cells (ASCs) from gastric biopsies. We
have also analyzed the antibody content in gastric aspirates, saliva and plasma.
There was a strong correlation between the total IgA levels in the biopsy
extracts and the frequencies of IgA-secreting cells. In addition, the IgA and IgG
levels against a H. pylori whole membrane preparation and purified urease in the
biopsy extracts correlated well with the frequencies of specific IgA and IgG
secreting cells. However, the antibody levels in gastric aspirates, saliva and
plasma specimens did not correlate with the frequencies of corresponding ASC in
the gastric biopsies. Thus, the saponin extraction method is suitable for
monitoring local antibody responses in the stomach, while analyses of gastric
aspirates, saliva or plasma are not appropriate for this purpose.
PMID- 10669770
TI - A simplified procedure for the preparation of MHC/peptide tetramers: chemical
biotinylation of an unpaired cysteine engineered at the C-terminus of MHC-I.
AB - Recently, a powerful approach for the detection of MHC/peptide-specific T cells
has been made possible by the engineering of soluble-tetrameric MHC/peptide
complexes, consisting of singly biotinylated MHC/peptide molecules bound to
fluorescent-labeled streptavidin. These tetrameric molecules are thought to
compensate for the low affinity and relative fast dissociation rate of the
TCR/MHC-peptide interaction by increasing the avidity of this interaction, thus
allowing the stable binding of MHC/peptide tetramers to TCR expressing cells.
Here we describe a new more simplified procedure for obtaining MHC/peptide
tetramers using the well-characterized H-2K(b)/VSV system. This procedure
consists of the incorporation of an unpaired cysteine residue at the C-terminus
of the H-2K(b) molecule, allowing site-specific biotinylation by a -SH-specific
biotinylating reagent. The H-2K(b)/VSV tetramers bound only to hybridomas
expressing H-2K(b)/VSV-specific TCRs. When coated on a plate, these tetramers
were able to induce IL-2 release by those hybridomas. Furthermore, H-2K(b)/VSV
tetramers bound to CTL populations obtained from mice immunized with VSV-peptide.
The specificity of the binding was further refined by studying cross-recognition
of VSV by CTL populations obtained from mice immunized with single amino acid
substituted VSV peptide variants. H-2K(b)/VSV tetramers bound only to those CTL
populations that cross-reacted with the wild-type VSV peptide. Our method
provides a simple, efficient and inexpensive procedure for making MHC/peptide
tetramers, a highly specific and very useful reagent with a number of important
applications in basic and clinical T cell research.
PMID- 10669771
TI - High-performance sodium dodecyl sulfate-capillary gel electrophoresis of
antibodies and antibody fragments.
AB - High-performance sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE)
has been used to separate antibodies and their fragments according to size. Under
non-reduced conditions, murine monoclonal antibodies generally show a predominant
peak with five to six apparent fragment peaks. The magnitude of the apparent
fragmentation is temperature-dependent and is more pronounced with rabbit, sheep
and bovine immunoglobulin G's than murine monoclonal antibodies. In addition to
temperature, pH and buffer also affect the fragmentation. Without heat treatment
during the preparation of the SDS-antibody complexes, the observed fragments
become nearly absent; however, some murine monoclonal antibodies exhibit several
peaks that group near the expected migration time of an immunoglobulin G,
presumably due to their anomalous interaction with sodium dodecyl sulfate. The
method can also be used to monitor the progress of peptic digestions to generate
murine F(ab')(2) antibody, to perform "gel-shift" assays, and to separate mouse
ascitic fluid. This high-performance electrophoretic technique is suitable for
quality control as well as the characterization of the antibodies under
experimental conditions.
PMID- 10669772
TI - Perfusion chromatography for very rapid purification of class I and II MHC
proteins.
AB - Major histocompatibility complex (MHC) proteins are surface glycoproteins that
are strongly associated with either self or foreign peptides. Their interaction
with the T-cell receptor on the T-cells initiates an immune response and help in
discriminating between self and non-self, respectively. We describe here a novel
means of rapidly purifying human MHC molecules on either small scale or large
scale from the cell lysate of lymphoblastoid B cell line and from insect cell
culture supernatants by using affinity perfusion chromatography. As
representative cases HLA-B2705, a class I MHC molecule, and HLA-DR1, a class II
MHC molecule were purified from EBV-transformed human lymphoblastoid B cells,
LG2. Soluble HLA-DR1 was also purified from the cell culture supernatant of
insect cells. The peptides eluted from the purified HLA-B2705 were pool sequenced
and found to have the same motif as has previously been published. This new
method provides a very rapid means of purifying MHC protein molecules, applicable
to both large scale and small scale purification, which in turn greatly enhances
the accuracy of further analysis of the associated peptides through mass
spectrometry.
PMID- 10669773
TI - Comparative study of two cytofluorometric methods of analysis.
AB - Cytofluorometry of lymphocytes is an important technique in experimental biology
and clinical medicine. One source of variability in the results with this
technique stems from the difficulty of delineating cell subpopulations on a
visual basis. We have evaluated the performance of a novel software method
(Attractor), which introduces cluster analysis for the more precise definition of
cell populations. Using 115 blood samples from patients with various
immunological diseases, we compared the results obtained for 19 lymphocyte cell
populations employing either the Attractor program or a conventional program
(Cellquest). The analysis focused on inter-observer and inter-method variability
and comparability. Inter-observer variability was significantly lower with the
Attractor software, particularly when quantifying small cell populations such as
activated subsets. The results obtained with both methods showed high correlation
coefficients except for some cell populations that were either very small or
which had to be calculated from the sum of other counts. The performance of the
novel flow cytometric software is similar to software programs currently in use,
but it offers an advantage for the definition of small and/or activated
lymphocyte subpopulations. Moreover, the consistency of the measurements is
better. A major disadvantage for statistical analysis, however, is that the
Attractor program has not been adapted for non-parametric data.
PMID- 10669774
TI - ELISA for a complexed antigen with a monoclonal antibody blocking reaction with
the free antigen-assay-specific for complexed prostate-specific antigen.
AB - We have developed an enzyme-linked immunoassay (ELISA) for serum complexed
antigen (prostate-specific antigen; PSA)(c-PSA) with simultaneous blocking of
free-antigen (PSA)(f-PSA). The assay utilizes three different monoclonal
antibodies (MAbs) recognising three distinct PSA epitopes. The detection limit
was established as 0.19 microg/l (n=20, mean of zero standard+2S.D.) and the
average recovery of f-PSA was 98-100%. The within-run and between-day
coefficients of variation (CV) ranged from 2.1% to 3.2% and 2.8% to 6.3%,
respectively. There was a good correlation between serum c-PSA measured by the
present ELISA and PSA-alpha(1)-antichymotrypsin complex (PSA-ACT) concentrations
(r=0.991). This method should provide a better tool for discriminating between
benign and malignant prostatic disease.
PMID- 10669776
TI - Identification of human TGF-beta1 signal (leader) sequence polymorphisms by PCR
RFLP.
AB - Links between disease susceptibility and genetically determined variation in
human cytokine expression have recently been described. This has led to a demand
for simple methods of identifying cytokine gene polymorphisms of potential
clinical relevance. Here, we describe a polymerase chain reaction-restriction
fragment length polymorphism (PCR-RFLP) method for identifying two human
transforming growth factor beta1 (TGF-beta1) signal (leader) sequence
polymorphisms, T869C (Leu10Pro) and G915C (Arg25Pro). This permits simple and
robust identification of TGF-beta1 leader sequence genotypes and demonstrates the
physical linkage in cis between T869C (Leu10Pro) and G915C (Arg25Pro). The method
does not require previously genotyped standards. The efficacy of enzyme digestion
is internally controlled by the presence of conserved restriction sites.
PMID- 10669775
TI - Generation of high-affinity rabbit polyclonal antibodies to the murine urokinase
receptor using DNA immunization.
AB - The urokinase receptor (uPAR) is a glycolipid anchored cell surface glycoprotein
that plays a central role in extracellular proteolysis during tissue remodeling
processes and cancer invasion. By intramuscular (i.m.) injection of rabbits with
plasmid DNA coding for a carboxy-terminally truncated secreted form of the murine
uPAR (muPAR), specific anti-sera with a titer of 64,000, as measured by ELISA,
have been obtained. Rabbits received a total of 10 monthly injections of 1 mg DNA
in phosphate-buffered saline. The antibody titer peaked between the 5th and 7th
injection and slowly declined after the 8th injection. After the final
immunization the immune response persisted for at least 6 months without further
injections. The antibodies generated by DNA immunization were useful for
immunohistochemistry and immunoblotting, recognizing the antigen both in its
native and in its reduced and alkylated form. Using the antibodies in
immunoblotting muPAR was identified in lysates of peritoneal macrophages, spleen
and lung tissue. Both the intact and cleaved form of muPAR were identified in
lysates of a murine monocyte cell line P388D.1. No cross-reaction with human uPAR
was observed. In immunohistochemical analysis of normal mouse lung tissue uPAR
immunoreactivity was located in the alveoli and pulmonary vessels, whereas the
bronchial epithelium was negative. These results demonstrate that DNA
immunization of rabbits using i.m. injection is a very effective and easy method
to raise polyclonal antibodies which can be used for characterization and
localization of muPAR in mouse tissue.
PMID- 10669777
TI - Production of monoclonal antibodies using recombinant baculovirus displaying gp64
fusion proteins.
AB - Generation of protein immunogens is often a rate-limiting step in the production
of monoclonal antibodies (Mabs). Expressing domains of proteins as fusions to the
baculovirus surface glycoprotein gp64 displays foreign proteins on the surface of
the virion. Antigen is produced by inserting a gene fragment in-frame between the
signal sequence and the mature protein domain of the gp64 nucleotide sequence.
This method allows immunization with whole virus, eliminating the need for
purification of target antigens. Affinity-matured Mabs to the human nuclear
receptors LXRbeta and FXR have been produced using baculovirus particles
displaying gp64/nuclear receptor fusion proteins as the immunizing agent.
Immunizations were performed directly with pelleted virus using the Repetitive
Immunization Multiple Sites (RIMMS) immunization strategy for rapid Mab
production. All Mabs were identified using insect cells infected with the
immunizing virus. Characterization of these antibodies shows them to be class
switched and specific for LXRbeta or FXR. Additionally, high affinity antibodies
that recognize gp64 and neutralize baculovirus infection of insect cells were
isolated. Use of the recombinant baculovirus gp64 display system makes possible
the production of Mabs once a partial DNA sequence is known. This allows the
generation of antibodies prior to the isolation of purified protein, in turn
providing antibodies to facilitate purification, characterization and
immunolocalization of proteins.
PMID- 10669778
TI - Transient expression of bacterial gene fragments in eukaryotic cells:
implications for CD8(+) T cell epitope analysis.
AB - CD8(+) T cells are potent effectors of acquired immunity against some viruses and
intracellular bacterial pathogens. Antigens recognized by CD8(+) T cells are
small, 8-9 amino acid peptides derived from proteins produced by the pathogen.
These peptides are presented by MHC class I molecules on the surface of the
infected cell. When characterizing the CD8(+) T cell response to a bacterial or
viral pathogen, it is often necessary to express an antigenic protein in a
eukaryotic host cell that is capable of processing and presenting peptide
epitopes to antigen-specific CD8(+) T cells. We describe a system designed to
transiently express bacterial polypeptides and MHC class I molecules in
eukaryotic cells. Recognition of these peptide-MHC complexes stimulates TNF
production by antigen-specific CD8(+) T cell lines. This system should be useful
for analysis of CD8(+) T cell epitope-containing bacterial gene fragments when
expression of the entire bacterial protein is detrimental to the eukaryotic cell,
or when overexpression of the bacterial gene is detrimental to the bacterial
cloning strain. Furthermore, this system can be used for the rapid mapping of
CD8(+) T cell epitopes within a protein.
PMID- 10669779
TI - A polymorphism in the mouse crg-2/IP-10 gene complicates chemokine gene
expression analysis using a commercial ribonuclease protection assay.
AB - The use of multiprobe RPAs is becoming an increasingly popular method for the
detection and quantitation of RNA levels in cells and tissues. Here we report
that due to a polymorphism in the 3'-noncoding region of the mouse Crg-2/IP-10
gene, the mCK-5 chemokine probe set available from Pharmingen can yield aberrant
signal patterns with RNA samples from BALB/c, MRL and possibly other mouse
strains that may lead to false conclusions regarding expression of the Crg-2/IP
10 and MCP-1 genes.
PMID- 10669780
TI - Cell-ELISA using beta-galactosidase conjugated antibodies.
AB - Cell-enzyme-linked immunosorbent assay (cell-ELISA) is a technique for the rapid,
convenient, and quantitative detection of molecules expressed on the cell
surface. Here we present an evaluation of beta-galactosidase as an antibody-tag
for cell-ELISA. In contrast to substrates for horseradish peroxidase (HRP) and
alkaline phosphatase, murine splenocytes do not hydrolyze the beta-galactosidase
substrate chlorophenolred-beta-D-galactopyranoside (CPRG). beta-Galactosidase
antibody conjugates show much lower background binding to murine T cells than
conjugates with HRP or alkaline phosphatase. We describe step-by-step procedures
for direct and indirect beta-galactosidase based cell-ELISA to quantitate the
expression of molecules on the surface of unfixed, live cells. Variations of the
basic protocol are suitable for adherent and non-adherent cells, large scale
screening for expression of cell surface molecules, and the screening of
hybridomas for production of antibodies to cell surface epitopes. Since
relatively few beta-galactosidase conjugated antibodies are commercially
available, we describe an efficient method to couple beta-galactosidase to
antibodies using a novel water soluble heterobifunctional crosslinker,
sulfosuccinimidyl 4-[N-maleimidomethyl]-cyclohexane-1-carboxylate (sulfo-SMCC).
We demonstrate the utility of this method by conjugating F(ab')(2) fragments of
an anti-B7-2 antibody, and using this conjugate to assay B7-2 on Fc-receptor
bearing cells.
PMID- 10669781
TI - The polyprotein lipid binding proteins of nematodes.
AB - The nematode polyprotein allergens/antigens (NPAs) are specific to nematodes, and
are synthesised as tandemly repetitive polypeptides comprising 10 or more
repeated units. The polyproteins are post-translationally cleaved at consensus
sites to yield multiple copies of the approximately 15-kDa NPA units. These units
can be highly diverse in their amino acid sequences, but absolutely conserved
signature amino acid positions are identifiable. NPA units are helix-rich and
possibly fold as four helix bundle proteins. The NPA units have relatively non
specific lipid binding activities, binding fatty acids and retinoids, with
dissociation constants similar to those of lipid transport proteins of
vertebrates. Fluorescence-based analysis has indicated that, like most lipid
transport proteins, the ligand is taken into the binding site in its entirety,
but the binding site environment is unusual. NPAs are synthesised in the gut of
nematodes, and presumably act to distribute small lipids from the gut, via the
pseudocoelomic fluid, to consuming tissues (muscles, gonads, etc.). In some
species, one of the units has a histidine-rich extension peptide which binds
haems and certain divalent metal ions. NPAs appear to be released by parasitic
nematodes, and may thereby be involved in modification of the local inflammatory
and immunological environment of the tissues they inhabit by delivering or
sequestering pharmacologically active lipids - they are known to bind arachidonic
acids and some of its metabolites, lysophospholipids, and retinoids. NPAs are the
only known lipid binding protein made as polyproteins, and are exceptions to the
rule that repetitive polyproteins are only produced by cells undergoing
programmed cell death and producing specialist products.
PMID- 10669782
TI - A conformational transition between an open and closed form of human pancreatic
lipase revealed by a monoclonal antibody.
AB - The interfacial activation of human pancreatic lipase (HPL) probably involves the
motion of a lid covering the active site of the enzyme. Here we observed that the
presence of either bile salts or a small proportion of water-miscible organic
solvents (called activator compounds) considerably enhances the enzymatic
activity of HPL on a monomeric solution of tripropionin. This finding suggests
that the activator compounds may favor the opening of the lid. This hypothesis
was checked by comparing the immunoreactivity of HPL and HPL with a mini-lid
(HPL(-lid)) towards anti-HPL monoclonal antibodies (mAbs), in the presence and
absence of the activator compounds. A single conformational mAb (248-31) fails to
immunoprecipitate HPL in the presence of activator compounds and HPL covalently
inhibited with diethyl p-nitrophenyl phosphate (DP.HPL). This loss of recognition
of HPL by mAb 248-31 was probably due to the motion of the lid, since HPL(-lid)
was always recognized in the presence or absence of activator compounds.
Furthermore, two other mAbs (81-23 and 146-40) immunoprecipitated HPL similarly
whether or not the activator compounds were present. MAb 248-31 therefore
specifically recognizes HPL in the closed but not the open conformation.
PMID- 10669783
TI - Tryptophanyl contributions to apomyoglobin fluorescence resolved by site-directed
mutagenesis.
AB - The individual emission properties of the two tryptophanyl residues of sperm
whale apomyoglobin have been resolved by examining the fluorescence variations
induced by denaturants, i.e., acid and guanidine, on apomyoglobin mutants W7F and
W14F. The fluorescence changes have been correlated to the conformational
transitions undergone by apomyoglobin on increasing denaturant concentration. The
results indicate that the fluorescence decrease, observed for sperm-whale
apomyoglobin on going from pH 8.0 to pH 6.0, cannot be ascribed to the formation
of a charge transfer complex between a nearby histidine residue and W14 as
reported in earlier papers but rather to minor structural changes affecting the
microenvironments of both residues. The formation of the acidic partly folded
state around pH 4.0 determines an increase of the fluorescence yield and a small
red shift (5 nm) of W7 due to removal of sterically interacting K79, which is
able to attenuate the emission of this residue in the native state. The
fluorescence intensity of the other residue, i.e., W14, is not affected by the
acidic transition. Guanidine denaturation experiments revealed an increase of
fluorescence yield of W14 upon the intermediate formation, whereas the
fluorescence of the other residue remained constant. The results suggest that the
unfolding pathway may be different depending on the chemical nature of the
denaturant used.
PMID- 10669784
TI - Implications of the S-shaped domain in the quaternary structure of human
arginase.
AB - Arginase I is a homotrimeric protein with a binuclear manganese cluster. At the C
terminus of each monomer, the polypeptide chain forms an unusual S-shaped
oligomerization motif where the majority of intermonomer contacts are located
[Z.F. Kanyo, L.R. Scolnick, D.E. Ash, D.W. Christianson, Nature 383 (1996) 554
557]. In order to study the implication of this motif in the quaternary structure
of human arginase I, we have constructed a truncated arginase lacking the 14 C
terminal amino acids, leaving Arg-308 as the last residue in the sequence. The
resulting protein retains its trimeric structure, as determined by gel filtration
(molecular mass 94 kDa). The same result was obtained in the presence of high
ionic strength (KCl 0.5 M). Both data indicate that neither the S-shaped motif
nor Arg-308 are fundamental in keeping the trimeric quaternary structure. Data
obtained from intrinsic anisotropy and fluorescence intensity studies allow us to
predict that the distance between the two unique tryptophans in the sequence is
2.9 nm in the native arginase and 4.1 nm for the truncated mutant. These
distances allow us to assume a different conformational state in the truncated
arginase without any change in its quaternary structure, suggesting that the
carboxy-terminal motif is not the most prominent domain implicated in the
quaternary structure of human arginase. Collisional quenching studies reinforce
this possibility, since using I(-) as quenching molecule we were able to
distinguish the two tryptophans in the truncated arginase. Moreover, kinetic
studies show that the truncated mutant was fully active. In summary, the main
conclusion about the structure of the human arginase I, derived from our study,
is that the C-terminal S-shaped motif is not basic to the maintenance of the
quaternary structure nor to the activity of the protein.
PMID- 10669785
TI - Characterisation of endoglucanases EGB and EGC from Fibrobacter succinogenes.
AB - The enzymatic properties of two endoglucanases from Fibrobacter succinogenes, EGB
and EGC, were analysed. EGB and EGC were purified from recombinant Escherichia
coli cultures expressing their gene. The failure of purification of EGB by
classical techniques led us to produce antipeptide antibodies that allowed
immunopurification of the protein from E. coli as well as its detection in F.
succinogenes cultures. Synthetic peptides were selected from the predicted
primary structure of EGB, linked to bovine serum albumin and used as immunogens
to obtain specific antibodies. One of the polyclonal antipeptide antisera was
used to purify EGB. EGC was purified by affinity chromatography with Ni-NTA
resin. The endo mode of action of the two enzymes on carboxymethyl-cellulose was
different. The values of K(m) and V(max) were respectively 13.6 mg/ml and 46
micromol/min mg protein for EGB, and 7 mg/ml and 110 micromol/min mg protein for
EGC. The reactivity of the antipeptide and the anti-EGC sera with F. succinogenes
proteins of molecular mass different from that of EGB and EGC produced in E. coli
suggested post-translational modification of the two enzymes in F. succinogenes
cultures. Expression of endB and endC genes in F. succinogenes was confirmed by
RT-PCR.
PMID- 10669786
TI - Engineering a compact non-native state of intestinal fatty acid-binding protein.
AB - The last three C-terminal residues (129-131) of intestinal fatty acid-binding
protein (IFABP) participate in four main-chain hydrogen bonds and two
electrostatic interactions to sequentially distant backbone and side-chain atoms.
To assess if these interactions are involved in the final adjustment of the
tertiary structure during folding, we engineered an IFABP variant truncated at
residue 128. An additional mutation, Trp-6-->Phe, was introduced to simplify the
conformational analysis by optical methods. Although the changes were limited to
a small region of the protein surface, they resulted in an IFABP with altered
secondary and tertiary structure. Truncated IFABP retains some cooperativity, is
monomeric, highly compact, and has the molecular dimensions and shape of the
native protein. Our results indicated that residues 129-131 are part of a crucial
conformational determinant in which several long-range interactions, essential
for the acquisition of the native state, are established. This work suggests that
carefully controlled truncation can populate equilibrium non-native states under
physiological conditions. These non-native states hold a great promise as
experimental models for protein folding.
PMID- 10669787
TI - Inactivation of N-terminal signaling domain of Sonic hedgehog by forming a
disulfide bond.
AB - The N-terminal domain of mouse Sonic hedgehog (Shh-N) expressed in mammalian
cells showed four-fold bands on non-reduced SDS-PAGE, though it was homogeneous
under reduced conditions. It contains three cysteine residues, Cys-25, Cys-103,
and Cys-184, which may be concerned with this heterogeneity. Therefore, we
examined the formation of a disulfide bond in the recombinant Shh-N and
identified three kinds of disulfides with a combination of peptide mapping and
NH(2)-terminal amino acid sequencing analysis. Among them, one type of the Shh-N
containing a disulfide bond of Cys-103/Cys-184 could be separated from the other
Shh-Ns using reverse phase HPLC and had no activity of alkaline phosphatase
induction in C3H10T1/2 cells. This molecule could also be made by denaturation of
the purified Shh-N with guanidine-HCl under non-reduced conditions. On the other
hand, the reduced Shh-N and the reduced S-methylated Shh-N at cysteine residues
showed approximately 10-fold higher activity compared to the originally purified
Shh-N. These results suggested that Shh-N was synthesized as an active form whose
three cysteine residues did not form disulfide and inactivated finally by forming
a disulfide bond between Cys-103 and Cys-184.
PMID- 10669788
TI - Aggregation of an amyloidogenic fragment of human islet amyloid polypeptide.
AB - Native human islet amyloid polypeptide (hIAPP) has been identified as the major
component of amyloid plaques found in the pancreatic islets of Langerhans of
persons affected by type 2 diabetes mellitus. Early studies of hIAPP determined
that a segment of the molecule, amino acids 20-29, is responsible for its
aggregation into amyloid fibrils. The present study demonstrates that the
aggregation of hIAPP 20-29-Trp is a nucleation-dependent process, displaying a
distinct lag time before the onset of rapid aggregation. Moreover, the lag time
can be eliminated by seeding the sample of unaggregated peptide with preformed
fibrils. In contrast to the expectation from the conventional model of nucleation
dependent aggregation, however, the lag time of hIAPP aggregation does not depend
on peptide concentration. To explain this observation, a modified version of the
standard model of nucleation-dependent aggregation is presented in which the
monomeric peptide concentration is buffered by an off-aggregation-pathway
formation of peptide micelles.
PMID- 10669789
TI - Escherichia coli cytosine deaminase: the kinetics and thermodynamics for binding
of cytosine to the apoenzyme and the Zn(2+) holoenzyme are similar.
AB - Recombinant Escherichia coli cytosine deaminase is purified as a mixture of
Zn(2+) and Fe(2+) forms of the enzyme. Fe(2+) is removed readily by o
phenanthroline to yield apoenzyme (apoCDase) that contains <0.2 mol of Zn(2+)per
mol of subunit. ApoCDase was efficiently reconstituted to Zn(2+)CDase by
treatment with ZnCl(2). The interaction of cytosine with apoCDase and Zn(2+)CDase
was investigated at pH 7.5 and 25 degrees C by monitoring changes in intrinsic
protein fluorescence. The values for the kinetic data K(1), k(2), and k(3) for
Zn(2+)CDase were 0.25 mM, 80 s(-1), and 38 s(-1), respectively. The value for k(
2) was statistically indistinguishable from zero. The analogous values for K(1),
k(2), and k(-2), (k(3)=0) for apoCDase were 0.157 mM, 186 s(-1) and approximately
0.8 s(-1), respectively. The overall dissociation constant of apoCDase for
cytosine was 0.00069 mM, whereas the K(m) of Zn(2+)CDase for cytosine was 0.20
mM. The pre-steady state phase of the reaction was associated with an absorbance
increase at 280 nm that was attributed to solvent perturbation of the spectrum of
cytosine or enzyme. Formation of the Fe(2+)CDase-cytosine complex was too rapid
to monitor by these techniques.
PMID- 10669790
TI - Construction and characterization of a catalytic fusion protein system: P
450(11beta)-adrenodoxin reductase-adrenodoxin.
AB - Cortisol is an important intermediate for the production of steroidal drugs and
can only be synthesized chemically by rather complicated multi-step procedures.
The most critical step is the 11beta-hydroxylation of 11-deoxycortisol, which is
catalyzed by a mitochondrial enzyme, P-450(11beta). Various fusion constructs of
P-450(11beta) with its electron transfer components, adrenodoxin and adrenodoxin
reductase, were produced by cDNA manipulation and were successfully expressed in
COS-1 cells from which the hydroxylation activities were assayed. It was
demonstrated that the fusion protein required both adrenodoxin reductase and
adrenodoxin for its activity and was not able to receive electrons from an
external source. The fusion protein with all three components had less activity
than P-450(11beta) alone, receiving electrons from coexpressed or internal
electron transfer components. The activities of the fusion proteins were
determined mainly by the fusion sequence. The fusion protein with a sequence of P
450(11beta)-adrenodoxin reductase-adrenodoxin was more active than that of P
450(11beta)-adrenodoxin-adrenodoxin reductase, 1.5- and 3-fold for bovine and
human P-450(11beta), respectively. Modification of the linker region by extending
the size of the linker with various peptide sequences in the bovine P-450(11beta)
adrenodoxin reductase-adrenodoxin fusion protein indicated that the linker did
not have significant effect on the P-450 activity. Taken together, the fusion
protein obtained here can serve as a model for the investigation of electron
transfer in P-450 systems and is of potential importance for biotechnological
steroid production.
PMID- 10669791
TI - Non-oxidative modification of lens crystallins by kynurenine: a novel post
translational protein modification with possible relevance to ageing and
cataract.
AB - In humans, the crystallin proteins of the ocular lens become yellow-coloured and
fluorescent with ageing. With the development of senile nuclear cataract, the
crystallins become brown and additional fluorophores are formed. The mechanism
underlying crystallin colouration is not known but may involve interaction with
kynurenine-derived UV filter compounds. We have recently identified a sulphur
linked glutathionyl-3-hydroxykynurenine glucoside adduct in the lens and
speculated that kynurenine may also form adducts with GSH and possibly with
nucleophilic amino acids of the crystallins (e.g. Cys). Here we show that
kynurenine modifies calf lens crystallins non-oxidatively to yield coloured (365
nm absorbing), fluorescent (Ex 380 nm/Em 450-490 nm) protein adducts.
Carboxymethylation and succinylation of crystallins inhibited kynurenine-mediated
modification by approx. 90%, suggesting that Cys, Lys and possibly His residues
may be involved. This was confirmed by showing that kynurenine formed adducts
with GSH as well as with poly-His and poly-Lys. NMR studies revealed that the
novel poly-Lys-kynurenine covalent linkage was via the epsilon-amino group of the
Lys side chain and the betaC of the kynurenine side chain. Analysis of tryptic
peptides of kynurenine-modified crystallins revealed that all of the coloured
peptides contained either His, Cys or an internal Lys residue. We propose a novel
mechanism of kynurenine-mediated crystallin modification which does not require
UV light or oxidative conditions as catalysts. Rather, we suggest that the side
chain of kynurenine-derived lens UV filters becomes deaminated to yield an
alpha,beta-unsaturated carbonyl which is highly susceptible to attack by
nucleophilic amino acid residues of the crystallins. The inability of the lens
fibre cells to metabolise their constituent proteins results in the accumulation
of coloured/fluorescent crystallins with age.
PMID- 10669792
TI - The binding of Na(+) to apo-enolase permits the binding of substrate.
AB - Enolase from rabbit muscle (betabeta-enolase) is inactivated by NaClO(4). Enolase
free of divalent cations is more susceptible to inactivation by NaClO(4) than is
enolase in the presence of Mg(2+). We find that substrate protects apo-enolase
against inactivation, indicating that substrate can bind to enolase in the
absence of a divalent cation. This binding is not due to contamination by trace
levels of divalent cations since (1) it occurs even in the presence of EDTA or
EGTA and (2) metal analysis by ICP (inductively coupled plasma) mass spectrometry
did not reveal sufficient contamination to account for the protection. The
binding of PGA to apo-enolase did require Na(+). When TMAClO(4) was used instead
of NaClO(4), there was no protection by PGA. Protection was restored when
TMAClO(4) plus NaCl were used. The inactivation of apo-enolase by NaClO(4) is due
to dissociation into inactive monomers. We conclude that Na(+) binds to apo
enolase, permitting substrate to then bind. Of the three known Me(2+) binding
sites on enolase, we believe the most likely binding site for Na(+) is the
carboxylate cluster of site 1, the highest affinity site of enolase.
PMID- 10669793
TI - Novel allosteric effectors of the tryptophan synthase alpha(2)beta(2) complex
identified by computer-assisted molecular modeling.
AB - Tryptophan synthase is a pyridoxal 5'-phosphate-dependent alpha(2)beta(2) complex
catalyzing the formation of L-tryptophan. The functional properties of one
subunit are allosterically regulated by ligands of the other subunit. Molecules
tailored for binding to the alpha-active site were designed using as a starting
model the three-dimensional structure of the complex between the enzyme from
Salmonella typhimurium and the substrate analog indole-3-propanol phosphate. On
the basis of molecular dynamics simulations, indole-3-acetyl-X, where X is
glycine, alanine, valine and aspartate, and a few other structurally related
compounds were found to be good candidates for ligands of the alpha-subunit. The
binding of the designed compounds to the alpha-active site was evaluated by
measuring the inhibition of the alpha-reaction of the enzyme from Salmonella
typhimurium. The inhibition constants were found to vary between 0.3 and 1.7 mM.
These alpha-subunit ligands do not bind to the beta-subunit, as indicated by the
absence of effects on the rate of the beta-reaction in the isolated beta(2)
dimer. A small inhibitory effect on the activity of the alpha(2)beta(2) complex
was caused by indole-3-acetyl-glycine and indole-3-acetyl-aspartate whereas a
small stimulatory effect was caused by indole-3-acetamide. Furthermore, indole-3
acetyl-glycine, indole-3-acetyl-aspartate and indole-3-acetamide perturb the
equilibrium of the catalytic intermediates formed at the beta-active site,
stabilizing the alpha-aminoacrylate Schiff base. These results indicate that (i)
indole-3-acetyl-glycine, indole-3-acetyl-aspartate and indole-3-acetamide bind to
the alpha-subunit and act as allosteric effectors whereas indole-3-acetyl-valine
and indole-3-acetyl-alanine only bind to the alpha-subunit, and (ii) the terminal
phosphate present in the already known allosteric effectors of tryptophan
synthase is not strictly required for the transmission of regulatory signals.
PMID- 10669794
TI - Heat shock protein (hsp90) interacts with smooth muscle calponin and affects
calponin-binding to actin.
AB - Interaction of smooth muscle calponin with 90 kDa heat shock protein (hsp90) was
analyzed by means of native gel electrophoresis and affinity chromatography.
Under conditions used, calponin and hsp90 form a complex with an apparent
dissociation constant in the micromolar range. The major hsp90-binding site is
located in the N-terminal (residues 7-144) part of calponin. Addition of calponin
to actin-tropomyosin complex results in formation of actin bundles. Hsp90
partially prevents bundle formation without affecting the molar ratio
calponin/actin in single actin filaments or actin bundles. At low ionic strength,
calponin induces polymerization of G-actin. Hsp90 decreases calponin-induced
polymerization of G-actin. It is supposed that hsp90 may be involved in the
assembly of actin filaments.
PMID- 10669795
TI - Primary structure determinants of the pH- and temperature-dependent aggregation
of thioredoxin.
AB - Thioredoxins are small proteins found in all living organisms. We have previously
reported that Chlamydomonas reinhardtii thioredoxin h exhibited differences both
in its absorption spectrum and its aggregation properties compared to thioredoxin
m. In this paper, we demonstrate, by site-directed mutagenesis, that the
particularity of the absorption spectrum is linked to the presence of an
additional tryptophan residue in the h isoform. The pH and temperature dependence
of the aggregation of both thioredoxins has been investigated. Our results
indicate that the aggregation of TRX is highly dependent on pH and that the
differences between the two TRX isoforms are linked to distinct pH dependencies.
We have also analyzed the pH and temperature dependence of 12 distinct variants
of TRX engineered by site-directed mutagenesis. The results obtained indicate
that the differences in the hydrophobic core of the two TRX isoforms do not
account for the differences of aggregation. On the other hand, we show the
importance of His-109 as well as the second active site cysteine, Cys-39 in the
aggregation mechanism.
PMID- 10669796
TI - Probing the interaction between N(1),N(4)-dibenzylputrescine and tRNA through
(15)N NMR: biological implications.
AB - NMR spectroscopy was used to characterize the binding properties of polyamines to
Escherichia coli tRNA. The (15)N NMR spectra of three (15)N-enriched N
substituted putrescine derivatives (DMP, DEP and DBP) were recorded in the
presence of tRNA, and the spin relaxation times of the nitrogen nuclei were
measured. From these data, the activation parameters for the rotational
correlation times of the (15)N nuclei were determined. The present data indicate
that the nature of the amino substituents does play a relevant role in
controlling the polyamine-tRNA interaction. This study also provides a rationale
for the in vivo antiproliferative effect of DBP against tumoral cells.
PMID- 10669797
TI - MALDI-TOF mass spectrometry analysis of substrate specificity of lebetase, a
direct-acting fibrinolytic metalloproteinase from Vipera lebetina snake venom.
AB - Lebetase is a direct-acting fibrinolytic zinc metalloendopeptidase related in
amino acid sequence to reprolysins which include both hemorrhagic and non
hemorrhagic proteinases. Despite apparent structural similarities, fibrinolytic
and hemorrhagic proteinases differ significantly in substrate specificity. In
this study, we have examined the activity of lebetase I against biologically
active peptides (bradykinin, kallidin, substance P) and 6-10 amino acid residues
containing peptides synthesized according to cleavage regions of alpha(2)
macroglobulin, pregnancy zone protein (PZP) and fibrinogen. Lebetase was found to
have no activity against studied hexapeptides. Surprisingly, the best substrates
for lebetase were substance P, and peptide fragment of PZP, both were cleaved at
position Pro-Gln. Identification of the hydrolysis products of 15 peptides by
MALDI-TOF mass spectrometry analysis indicates that lebetase possesses broad
substrate specificity. The MALDI-TOF MS technique was proven to be highly
efficient for the recovery and identification of the peptides released by
lebetase hydrolysis.
PMID- 10669798
TI - Anterograde axonal transport of Boc-Arg-Val-Arg-Arg-MCA hydrolyzing enzyme in rat
sciatic nerves: cleavage occurs between basic residues.
AB - Axonal transport of Boc-Arg-Val-Arg-Arg-MCA hydrolyzing enzyme activity was
studied in rat sciatic nerves from 12 to 120 h after double ligations. The
anterograde axonal transport increased and peaked 72 h after ligation. The
optimum pH for Boc-Arg-Val-Arg-Arg-MCA hydrolyzing enzyme activity was 6.5 to 6.9
and did not require Ca(2+) for the activity. Two molecular forms with enzyme
activity were identified by size-exclusion chromatography and the molecular
masses of the two enzymes were estimated to be 98 and 52 kDa. Two enzyme
activities were strongly inhibited by Hg(2+), Cu(2+) and trypsin inhibitors such
as TLCK, antipain and leupeptin. It cleaved the substrate, Boc-Arg-Val-Arg-Arg
MCA, between the dibasic sequence Arg-Arg, and needed a support of aminopeptidase
B-like enzyme activity for the liberation of 7-amino-4-methylcoumarin. These
results suggest that the enzyme is transported in rat sciatic nerves and involved
in the post-translational processing of precursor proteins under the anterograde
axonal transport. But there is absolutely no evidence for a role in precursor
processing and such a putative role is purely speculative.
PMID- 10669799
TI - Conformational studies of Actinobacillus actinomycetemcomitans leukotoxin:
partial denaturation enhances toxicity.
AB - A 114 kDa, water-soluble, cytotoxin secreted by the Gram-negative bacterium
Actinobacillus actinomycetemcomitans (Aa) is similar in sequence to Escherichia
coli alpha-hemolysin, but is non-hemolytic, killing leukocytes of select species,
including humans. In this work, we investigated aspects of the water-soluble
conformation of Aa toxin which relate to its biological, pore-forming activity.
The toxin has five native tryptophans and fluorescence spectra were monitored in
aqueous solutions in the presence of varying denaturants. Significant changes in
the fluorescence spectra, without significant wavelength shifts, were induced by
small additions of denaturants and changes in the temperature or pH. The
fluorescence changes suggested that small perturbations in the aqueous
environment resulted in structural changes in the toxin related not to a large
unfolding but to more subtle conformational changes. Analytical
ultracentrifugation showed the toxin to be a globular monomer in dilute aqueous
solution. Circular dichroism spectroscopy showed about 25% alpha-helical
structure which is largely maintained up to a temperature (65 degrees C) known to
deactivate toxin activity. Changes in the cytotoxic properties of the toxin were
monitored with flow cytometric analysis following preincubation of the toxin
under mild conditions similar to those used in the fluorescence studies. These
experiments showed that the pretreated toxin exhibited enhanced cell-killing
potency on toxin-sensitive cells. The correlation of cytotoxicity with the
changes in Trp fluorescence is consistent with the idea that partial unfolding of
Aa toxin is an early, obligate step in toxin-induced cell kill.
PMID- 10669800
TI - Rabbit phosphoglucose isomerase/neuroleukin/autocrine motility factor: cloning
via interspecies identity.
AB - Phosphoglucose isomerase is the first committed enzyme of glycolysis. The protein
also has a variety of biological activities on mammalian cells. The molecular
basis of these extracellular functions is unclear, and the high resolution three
dimensional structure of a mammalian enzyme has not been described. We report
here the cDNA and protein sequence for phosphoglucose isomerase from rabbit
muscle. The sequence was obtained directly by PCR without the need to screen
clones from a cDNA library and encoded active enzyme when expressed in bacterial
cells. The 558 amino acid rabbit coding sequence is the same length as and highly
similar (92% residue identity) to the sequences from human and pig and less so
(88%) to the mouse enzyme. Non-conservative amino acid changes between the four
mammalian sequences are concentrated in the first 35 and last five residues. The
rabbit protein has an additional Cys residue and amino acid changes at five
positions otherwise invariant in the mammalian enzymes.
PMID- 10669801
TI - Characterization of the gene encoding the [Fe]-hydrogenase from Megasphaera
elsdenii.
AB - The gene encoding the [Fe]-hydrogenase from the anaerobic bacterium Megasphaera
elsdenii has been cloned and sequenced. The gene is monocistronic, in keeping
with the protein being a monomer. The translated protein sequence (484 residues,
M(r)=53 kDa) comprises a small 2[4Fe-4S] ferredoxin-like domain and a large
domain containing the catalytic site. Comparisons with other [Fe]-hydrogenase
sequences, including two of which the crystal structures are known, show that the
M. elsdenii protein is among the smallest of these enzymes and provide useful
indications regarding the basic structural core common to all [Fe]-hydrogenases.
It is, nevertheless, to be noted that the genome of Thermotoga maritima encodes a
putative [Fe]-hydrogenase that would consist of only 301 residues.
PMID- 10669802
TI - A common motif in proparts of Cnidarian toxins and nematocyst collagens and its
putative role.
AB - In Cnidarians, cnidoblast cells contain organelles called cnidocysts, which are
believed to be the product of an extremely complex regulated secretory pathway.
When matured, these stinging organelles are capable of storing and delivering
toxins. We hypothesized that translated nematocyst proteins might comprise
specific sequences serving as signals in sorting to the organelle. A sodium
channel neurotoxin from the sea anemone Actinia equina was cloned and the toxin
precursor sequence was compared to those of nematocyst collagens, pore-forming
toxins and ion channel neurotoxins. It was found that all the analyzed sequences
possess a highly conserved stretch of nine amino acid residues ending with Lys
Arg N-terminally of the mature region.
PMID- 10669803
TI - Cloning and nucleotide sequence of a gene encoding a glycogen debranching enzyme
in the trehalose operon from Arthrobacter sp. Q36.
AB - A gene located just upstream of the treYZ operon was isolated from Arthrobacter
sp. strain Q36. The gene, designated treX, encoded an 823-amino acid protein. The
amino acid sequence of the protein had 50% identity with the TreX protein
(isoamylase) from Sulfolobus acidocaldarius ATCC 33909 which has a treZXY operon
on the genome. We suggest that Arthrobacter treX is an isoamylase gene, and that
it is a component of a treXYZ operon.
PMID- 10669804
TI - Crystallization and preliminary X-ray crystallographic analysis of alginate lyase
A1-II from Sphingomonas species A1.
AB - Alginate lyase A1-II of Sphingomonas species A1 was purified and crystallized
using the hanging drop vapor-diffusion method in 0.1 M Tris-HCl buffer containing
43% saturated ammonium sulfate, 8% polyethylene glycol 4000 and 0.2 M Li(2)SO(4)
at pH 8.5 and 20 degrees C. The crystals are tetragonal and belong to the space
group P4(3)2(1)2 or P4(1)2(1)2 with unit cell dimensions of a=b=144.07 and
c=296.38 A. The diffraction data up to 2.8 A were collected by a synchrotron
radiation source at SPring-8 in Japan.
PMID- 10669805
TI - [Chemical weapons: antidotes. View about the real means, perspectives].
AB - Chemical methods remain a credible threat in 1999. The doctrine for their use not
only includes the battlefield but also domestic terrorism as was disclosed during
the Tokyo metro attempt in 1995. International Treaties have not yet proven their
efficacy. The arsenal of chemical weapons has changed little since the second
World War but is now dispersed into many high-risk zones throughout the world.
There has also been little change in antidotes: therapeutic prevention with
pyridostigmine against organo-phosphorus compounds, protective treatment for
seizure-induced brain lesions using anticonvulsants in association with oxime for
acetylcholinesterase reactivation, and atropine are combined in a three
compartment syringe. Preventive measures against vesicants and other suffocating
or toxic intracellular substances (CN, AsH(3), fluorocarbons.) can only be
achieved with protective skin covering or protective breathing devices. There is
no specific treatment and we often have to use symptomatic medications. Future
perspectives include: phosphotriesterases as organo-phosphorus scavengers,
huperzine as pretreatment and gacyclidine (GCK 11) which would effectively
complete emergency multiple drug therapy against nerve agents. A new two
compartment syringe is now prepared with atropine, avisafone and HI6 or
pralidoxine. A gel made of cyclodextrines for external and eventually internal
use is under study.
PMID- 10669806
TI - [Pretreatment of organophosphate poisoning: potential interests of huperzine A].
AB - Pyridostigmine which is widely used as pretreatment of organophosphate poisoning
protects cholinesterases of peripheral nervous system. Other molecules able to
also protect the central nervous system are under study and, among them,
huperzine A. This paper gives an overview of the current investigations about the
efficacy and the innocuity of this molecule (study of the mechanisms of action,
biological targets, behavioural manifestations) and brings out its potential
interests.
PMID- 10669807
TI - [Interest in an glutamate antagonistic compound for the treatment of
organophosphate poisoning].
AB - Classical emergency treatment of organophosphate poisoning includes the combined
administration of a cholinesterase reactivator (an oxime), a muscarinic
cholinergic receptor antagonist (atropine) and a benzodiazepine anticonvulsant
(diazepam). In subjects taking pyridostigmine and trained to autoadminister at
least one autoinjector at the first signs of poisoning, classical emergency
treatment ensures survival but only an antiglutamatergic compound like
gacyclidine appears to be able to ensure optimal management of nerve agent
poisoning in terms of rapid normalization of EEG activity, clinical recovery and
total neuroprotection. All of this reinforces the therapeutical value of
gacyclidine, which is in the process of approval for human use in France for
treatment of head injury, as a central nervous system protective agent for the
treatment of OP poisoning.
PMID- 10669808
TI - [Substituted cyclodextrins as chelating reagents for ethers, thioethers and
yperite].
AB - The complexation of mustard gas Cl(CH(2))(2)S(CH(2))(2) Cl, HD, yperite) and of
ethers and thioethers derivatives by cyclodextrins: natural alpha-cyclodextrin
(ACD) and substituted B-cyclodextrins was studied by NMR. A 1/1 stoechiometry was
found in all cases, while affinity constants were found relatively weak (from 5
M(-1) to 100 M(-1)). However, these results show that chelation of HD by
cyclodextrins can be reasonably expected, especially if chemical modifications
provide stronger affinity constants.
PMID- 10669809
TI - [The threat represented by toxins: myth or reality?].
AB - The reasons underlying our fear of the use of toxins as new weapons different
from chemical agents are discussed together with the conditions required for
their use on the battlefield. The undeniable scientific contribution of toxins as
pharmacological tools for the study of neurosciences and disease genesis and
their prophylaxis is emphasized. In conclusion, the threat for mankind
constituted by proliferation of this novel class of agents is stressed.
PMID- 10669810
TI - [Natural biological risks and military biological risks].
AB - The Iraqi biological program, the activities of sect Aum in Japan and the
extensive endemicity of plague prove the existence of military, terrorist and
natural biological risks. Among the agents of natural risk (viruses, bacteria.),
plague is induced by modification of the ecosystem. Present since 1921 in the
high plateau of Madagaskar, the disease evolves under two modes, endemic
(natural) or epidemic (urban). Since the control of endemicity is impossible, the
decrease of incidence will be obtained by the control of the animal reservoir.
The military risk is part of the history of armed conquests. Anthrax and
botulinum toxins, are the most toxic agents, banned by the Convention of London
(1972). In 1995, 4 years after the end of Gulf war, UNSCOM obtained from
authorities the inventory of Iraqi biological program, with details on the
militarization of toxins and spores. These furtive weapons, are produced with
limited technological skills, often in dual manufactures and are difficult to
control.
PMID- 10669811
TI - [Risks related to the uncontrolled development of pharmacognosy in the United
States and France].
AB - A number of plants of ancestral tradition exhibit properties deserving
therapeutic applications. However, their use in conditions which do not guarantee
sufficient safety may lead to incidences and sometimes serious accidents. In the
US the weakness of the present provisions of the federal regulation do not allow
a satisfactory and preliminary control. Moreover, these plants are mostly
prescribed by non-medicals and outside the authority of pharmacists. This
situation would be highly prejudicial if it would be implemented in Europe.
France has a well conceived and satisfactory system, but which is unable to
benefit from new accessions, namely exotic plants. To ignore them would lead to
strengthening the already existing and parallel organizations. The authors
suggest that the health authorities should create a complementary system open to
new medicinal plants, avoiding uncontrolled sales. They suggest also that before
any acceptance a realistic probationary period would be applied in order to
evaluate the quality but overall the eventual toxicity of these plants.
PMID- 10669812
TI - [Pharmaceutical development concerning diseases predominating in tropical
regions: the concept of indigent drugs].
AB - When the WHO certified the eradication of smallpox in 1981, there was a general
impression that the fight against infectious diseases which began with Jenner and
Pasteur was entering a phase of achievement: poliomyelitis, dracunculasis,
leprosy, Chagas' disease and neonatal tetanus were also responding to eradication
campaigns. However, in 1995, infectious diseases are still an important cause of
mortality and morbidity and the rising incidence of emerging or re-emerging
diseases remains a matter of great concern. Although this situation can be
explained, at least partly, by the deterioration of health care systems and
diverse socio-economic and ecological disorders, important changes occurring in
the drug industry since 1980 have also played a role due to changes in pharmaco
epidemiology and new policies of drug development. Among the 1061 new drugs
developed from 1975 to 1994, less than 2.7% concern tropical diseases. Since
praziquantel, novel drugs have issued from veterinary medicine (ivermectin),
military research (halofantrine, mefloquine) or fortuitous analysis of
pharmacopoeia (artesunate). The cost of investments and the lack of market
potential and market security in developing countries have dampened interest in
developing drugs for tropical diseases. Observing the combined effect of
deficient pharmaceutical development, drug wear due to chemoresistance
(chloroquine, sulfadoxine-pyrimethamine, aminopenicillins), the cost barrier
(second generation molecules) and the potential abandon of major drugs
(eflornithine, melarsoprol) has led us to establish a classification of these
"indigent" drugs (in opposition to "orphan" drugs) into five classes: true
indigent drugs (eflornithine), indigent drugs by indication (pentamidine),
indigent drugs by function (ceftriaxone), indigent drugs by formulation
(melarsoprol) and indigent drugs by default (suramin). This analysis can serve as
a basis for a search for solutions (regulatory, administrative and financial
incentives) favoring a reactivation of drug development for diseases
predominating in intertropical regions.
PMID- 10669813
TI - Interactions between chitosan and glycosaminoglycans (chondroitin sulfate and
hyaluronic acid): physicochemical and biological studies.
AB - Chitosan is a polysaccharide well known for its numerous and interesting
biological properties, indeed, it is a biocompatible, bioresorbable and bioactive
biopolymer. It is therefore often introduced in the human body, where it happens
to be in contact with glycosaminoglycans (GAG's), especially chondroitin sulfates
and hyaluronic acid which play important part in living media. Thus it seems
interesting to consider systems associating chitosan and GAG's. The aim of our
work is to study the mechanism of formation of biomaterials constituted of
chitosan and GAG's which could have interesting biological properties such as
improving the wound-healing acceleration and the cellular assistance for skin and
cartilage recovery. In the same time, it was interesting to try to understand
what can happen when chitosan is introduced in a natural surrounding containing
GAG's. In a first part, the complexes between chitosan and GAG's were
characterised by various physicochemical techniques: pH-metry, conductometry and
Infra-red spectrometry. They appeared to be polyelectrolyte complexes obtained by
the formation of polyanion-polycation interactions held between ammonium
functions of chitosan and carboxylate and/or sulfate groups of GAG's. The
complexes formed are very strong and can, in some cases, even conduct to the
deprotonation of carboxylic functions. In a second part we considered the
biological properties of the complexes previously obtained. The hydrolysis
activity in presence of specific enzymes was investigated. We also studied the
cytocompatibility of chitosan alone and its complexes with the two considered
GAG's toward two kinds of cells (chondrocytes and keratinocytes). At the end of
the work, a short animal experimentation on rats was performed allowing the
comparison between in vitro and in vivo results.
PMID- 10669814
TI - [Transgenic mice expressing MTCP1: an animal model for T-cell prolymphocytic
leukemia].
AB - T-prolymphocytic leukemia (T-PLL) is a rare form of mature T-cell leukemia
associated with chromosomal rearrangements of band 14q11, containing the gene
TCRA/D, and bands 14q32.1 and Xq28, where the TCL1 and MTCP1 putative oncogenes
have been identified. These genes encode two homologous proteins, p14(TCL1) and
p13(MTCP1) respectively, which share no similarity with other known proteins. To
determine the oncogenic role of MTCP1, transgenic mice with an expression of
MTCP1 targetted to the T-cells were generated. A lymphoid malignancy similar to
Human T-PLL occurred in to independent transgenic lines with a high level of
expression of the transgene. The cumulative incidence of the disease at 20 months
was 100% and 50% respectively, and null in the control group. The oncogenic role
of MTCP1 is demonstrated, and the p13(MTCP1) and p14(TCL1) proteins form a new
oncoprotein family. The long latency period before emergence of tumors suggests
that activation of MTCP1 is not sufficient to generate the malignant
transformation. The secondary genetic events implicated in tumoral progression
remain to be elucidated, in order to reconstruct the molecular history of the
disease.
PMID- 10669816
TI - [ [In Process Citation]
PMID- 10669817
TI - [ [In Process Citation]
PMID- 10669815
TI - [The prescription in dispensary practice].
AB - Although the medical prescription is a well-established process, prescribing in
the pharmacy does not follow a well-defined set of rules as, in official terms,
there is no such thing as a pharmaceutical prescription. Despite this fact, daily
pharmacy practice involves giving professional advice and dispensing drugs not
only in fulfillment of a medical practitioner's prescription but also by selling
drugs the pharmacist personally advises use of. In this particular case, the
pharmacist must assess the patients desire for a specific treatment and determine
whether it is well founded. The pharmacist has to decide whether he/she can deal
with the presenting symptom or whether the person should be referred to a
practising physician. For example, often-recurring mouth disease such as mouth
ulcers and gingivitis can be handled within the pharmacy. The pharmacist may
think of implementing a suitable treatment involving dietary and hygienic
counselling and dispense carefully selected drugs. The situation is similar in
many other clinical conditions. As the pharmacist has had professional training
in drugs at the university and teaching hospital, he/she is the expert in drugs
and can rightly claim entitled to prescribing drugs within reasonable limits.
PMID- 10669818
TI - [2000-2010: bone and joint decade].
PMID- 10669819
TI - [Radiographic assessment of polyethylene wear in machined versus molded
polyethylene in total hip prosthesis].
AB - PURPOSE OF THE STUDY: Wear of polyethylene acetabular components is an important
issue in total hip arthroplasty. This study was designed to evaluate differences
in polyethylene wear rates between machined and direct compression molded
acetabular cups. METHODS: Two hundred thirty-nine prostheses underwent
radiographic evaluation using the technique of Chevrot-Kerboull. One hundred
thirty-one were all-polyethylene cups machined from extruded bar stock, and one
hundred eight were all-polyethylene cups direct compression molded. Both groups,
all operated on in 1988, were similar in the acetabular and femoral components,
were all cemented, and the acetabular components were all-polyethylene, non metal
backed. The femoral components were all Charnley-Kerboull MK III type. Patient
weight, average weight, the post-operative PMA score and the duration of the
follow-up were similar for the two groups (mean 7.4 years). RESULTS: Results
showed a mean linear wear rate of 0.06 mm per year for compression-molded
polyethylene and 0.08 mm per year for machined polyethylene. Results were not
significantly different. The number of acetabular radiolucencies in zone I (5.5
versus 5.3 p. 100) and the amount of lysis of the proximal part of the femur did
not differ between the two groups. The number of excessive wears did not differ
either. DISCUSSION AND CONCLUSION: Although polyethylene wear was lower with
compression molded acetabular cups than with ram-extruded acetabular cups,
results of this study suggest a non significant difference between the two types
of components. A more controlled experiment would have to be performed to
attribute a difference between two different types of UHMPE processing.
PMID- 10669820
TI - [Oxidation of ultra high molecular weight polyethylene as a result of
sterilization].
AB - PURPOSE OF THE STUDY: To improve (UHMWPE) Ultra High Molecular Weight
Polyethylene quality for use in arthroplastic components, sterilization related
oxidative changes were investigated in raw and manufactured material. MATERIAL:
To evaluate sterilization related effects, 15 x 15 mm samples of UHMWPE were
taken from a defined area of raw manufactured UHMWPE plates. The raw manufactured
plates were produced using the compression molding method. For sterilization,
gamma irradiation with and without air, ETO-sterilization and autoclave
sterilization were performed. METHODS: Infrared spectroscopy was used to detect
oxidation damage of the implant in superficial and deep layers of the material.
RESULTS: Gamma sterilization on air showed 40% more oxidation compared with air
free sterilization. The superficial oxidation on air was 0.33 and showed the
lowest value without air on argon with 0.155. Using ethylenoxide sterilization,
no great changes in superficial oxidation (0.229) were observed; the smallest
change (0.07) was observed at a depth of 2.79 mm. Autoclave sterilization caused
the greatest superficial oxidation with 0.622 but low oxidation at 0.094 mm
depth. In all samples, further oxidation and ongoing crystallinity was seen with
increasing storage time. CONCLUSION: Ethylenoxide sterilization should be
recommended for UHMWPE since oxidative changes is lowest. Gamma sterilization can
only be recommended without air and at low doses.
PMID- 10669821
TI - [Osteolysis after total knee prosthesis].
AB - PURPOSE OF THE STUDY: The aim of our work was to study X-rays showing osteolysis
after 5 years and more in 122 prosthesis and to try and assess such complication,
often described in the United States but seldom in Europ. MATERIAL: We are
dealing here with 122 retaining posterior cruciate ligament, mostly cementless
prothesis implanted between 1985 and 1992 84 chromium-cobalt prosthesis (PCA and
Themis) implanted in 34 males and 88 females with an average age of 67 (45-81),
87,7 p. 100 had femoral cementless components and 70 p. 100 tibial cementless
components. METHODS: All patients were examined and had X-rays at an average of
6,9 years. Specially considered were X-rays showing a possible osteolysis. We
looked for possible complication (external laxity, anterior femoral dislocation
and polyethylene wear), assessment of the mechanical axis and for clinical
results (Hungerford score) RESULTS: Revisions: 19 arthroplasties were revised for
PE wear tibial loosening metallosis or patella problems The postoperative score
according to Hungerford was 84,5 p. 100 for PCA prosthese and 87 p.100 for the
Themis. On the X-rays were only few osteolysis to be found: 9 cases (7,3 p. 100).
For the PCA series: 3 femoral osteolysis, 1 tibial at 12 years, and one patellar
osteolysis. For the Themis series: no femoral osteolysis, 3 tibial and one
patellar osteolysis. Osteolysis are apparent on X-rays in profile for the femur
and the patella, and in both profile and frontal X-rays for the tibia. Clinicaly
4 osteolysis really asymptomatic were not re-operated. 5 were revised: one 11
years later for femoral and tibial loosening, two for a patellar loosening, the
other two patients had to be reoperated on for metallism (titanium's femoral
component) and for those two instances osteolysis were discovered during the
complication. DISCUSSION: Osteolysis after TKA appears unusual in our experience
without bearing on frequency finded by american authors with a lesser follow-up
(Engh 11,1 p. 100 after 4,5y, Peters 16 p. 100 after 2,9 y, Robinson 9,18 p. 100
after 4,6 y). American litteratur analysis shows that the important number of
osteolysis is due to: - either to dual-metal using (Co-Cr component with Titanium
screws for exemple), - or bad quality of polyethylene (compressed), - or a bad
design of former prosthesis. CONCLUSION: Interface illness, linked to the
production of wear debris, osteolysis after total knee arthroplasty is rarer than
after a hip one, probably because size of debris is different, larger in knee
than in hip. It is likely that the improvement of PE quality, design of
prosthesis, as well as a better knowledge of osteolysis mechanism will allow to
delay this complication wich is in a long term ineluctable.
PMID- 10669822
TI - [Tibial fracture with intact fibula treated by reamed nailing].
AB - PURPOSE OF THE STUDY: The main difficulties encountered in the orthopedic
treatment of leg fractures with intact fibula are reduction of the tibial and an
unusually high rate of varus unions and non-unions. The aim of this retrospective
study was to assess the outcome after reamed nailing of tibial fractures with an
intact fibula. MATERIAL AND METHOD: Between 1986 and 1997, 38 fractures of the
tibia with an intact fibula were treated by first intention centromedullar
nailing. There were 28 men and 10 women, mean age 28 years, with a single
fracture in 25 cases. There were 25 motor vehicle accidents (17 two-wheel, 8 four
wheel), 5 sports accidents, 2 home falls, and 6 others. Fracture of the tibial
diaphysis was associated with a homolateral femoral fracture in 7 cases, 7
fractures were open (7 type 1, 2 type 2, 1 type 3), 7 fractures were associated
with abrasive skin lesions. Using the AO classification, the tibial fracture was
type A in 26 cases, type B in 11, and type C in 1. The fracture was in the middle
third of the tibia in 21 cases, the distal third in 15 and in the proximal third.
Grosse and Kempf nails were used exclusively. Static nailing was used in 27
cases, dynamic nailing in 8, and the nail was not locked in 3 cases. Nails of
diameter 9 to 13 were implanted after reaming 1 mm more. RESULTS: The fracture
gap increased during the reaming in 5 patients; 2 patients had to undergo a
secondary aponeurectomy due to a postoperative compartment syndrome and had no
further sequela. Consolidation was achieved after the first intention treatment
in 30 patients, after dynamization in 6. A non-union in 2 patients was also
successfully managed with new nailing and dynamization. Delay to consolidation
was a mean 175 days (range 60 - 480). Transverse fractures consolidated more
rapidly (mean 122 days). At last follow-up (minimum 1 year), active knee and
ankle mobility were normal in all patients. Nineteen patients complained of pain
at the site of the nail insertion, evaluated at 1 on a 10-point analogie scale by
10 of them and at 2 by the 9 others. Eight out of 10 patients felt cure had been
achieved 5 months postoperatively. DISCUSSION: These rapidly obtained clinical
results and the relatively low rate of non-union (5 p. 100) should be attributed
to the reamed nailing technique. We discuss the frequency of tibial fractures
with intact fibula and the underlying circumstances. The lack of patent fibular
fracture does not signify the fibula is intact. Trauma-induced tibio-fibular
dislocation (1 case in our series) can occur. A review of the literature
emphasizes the frequency of non unions and misalignment after orthopedic
treatment. The most widely used surgical technique is reamed nailing. This
technique has the inconvenience of possible pain at the insertion site which
usually disappears after ablation of the nail and also a compartment syndrome
where reaming is a possible aggravating factor. CONCLUSION: Nailing is a reliable
technique for the treatment of tibial fractures with an intact fibula. Weight
bearing should be encouraged as early as possible. The indication for a locked
nail depends on the anatomic type of the tibial fracture and its localization.
Immediate weight bearing should be recommended. Strict surveillance allows
dynamization with fibulotomy in case of late consolidation. Prospective
randomized studies comparing nailing with other therapeutic methods are needed to
confirm these data.
PMID- 10669823
TI - [Subcutaneous tenotomy of Achille's tendon in adults for ankle stiffness. A
review of 80 cases].
AB - PURPOSE OF THE STUDY: Lengthening of Achille's tendon is part of surgical program
for ankle stiffness in equinus deformity. Usually this lengthening is done by
opened surgery with all the well-knowned advantages in term of adjustment. We
used a percutaneous method for Achille lengthening with a two stages tenotomy.
The purpose of this study is to evaluate advantages, inconvenients and efficiency
of the subcutaneous method versus the open method. MATERIALS AND METHODS: We
present a retrospective study of a 80 percutaneous lengthening of Achille's
tendon in 78 patients done between August 85 and January 96. All patients who
went to surgery during this period were reviewed. Mean age was 36 years old and
there was 39 left sides and 41 right sides. We separated the extra-articular
stiffness (48 cases) and the intra-articular stiffness (32 cases) because in
extra-articular etiology the stiffness is a consequence of a primitive neuro
muscular disease as the ankle joint is healthy. 46 ankles had a past history of
surgery. The kind of surgery was directely related to the etiology of the
equinus. Most of the time, Achille lengthening was the last time of joint
mobilisation. Only 15 times lengthening of the equinus tendon was done isolated.
We looked at the early results for all patients and late results were only
evaluated for the patients who had an isolated lengthening of the Achille tendon
the for stastitical reasons. RESULTS: Median follow-up is two and an half years.
There was preoperatively 59 ankles equinus and correction was constantly obtained
with surgery postoperative improvment was 12 degrees of dorsal ankle flexion. In
sub population of isolated achillus lengthening mean gain is 17 degrees. Only one
patient had a per-operative complication with an heel anesthesia. We had no late
complication related to the method. DISCUSSION: Results of this reviewal confirms
efficency of the percutaneous technique in adult. Litterature is very poor
concerning Achille's tendon lengthening in adult surgery. It is a very widelly
spread method in children. Only few authors have published about it in adults
mainly about hemiplegic patients. Our method saves tourniquet time in heavy ankle
surgery. There are no painful and sticky scar. Morbidity is very low because we
only had one complication related to the method. Healing up of tendon is very
good, all patients being able to rase up on their toes. CONCLUSION: A review of
our cases showed us the real efficency of this technique. It's a very simple and
quick method giving good results with low morbidity. For us there is no
indication of open surgery for achille's tendon lengthening.
PMID- 10669824
TI - [Neurogenic mixed evoked potential monitoring during scoliosis surgery:
retrospective analysis of 149 cases].
AB - INTRODUCTION: We report a retrospective analysis of spinal cord monitoring with
neurogenic mixed evoked potentials (NMEPs) combined with somatosensory evoked
potentials (SSEPs) in 149 patients undergoing surgery for spinal deformity.
MATERIAL AND METHODS: 149 patients (104 females and 45 males), mean age 28 yrs
(13-72 yrs) were studied. NMEPs were elicited by electrical spinal cord
stimulation in the rostral part of the surgical field, via two needle electrodes
set in the epidural space and in the interspinous ligament above. They were
recorded from the sciatic nerve at the knee and the sural nerve at the ankle.
SSEPs were recorded from the scalp after stimulation of the posterior tibial
nerve at the ankle. A decrease in amplitude of more than 50 p. 100 and/or an
increase in latency of more than 10 p. 100 were defined as significant warning
criteria. RESULTS: No false-negative result was observed. NMEP modifications did
not reach critical value in 143 cases. In 6 cases, significant changes were
observed. Moving the stimulation electrodes along the spinal cord allowed spinal
lesion localization and helped the surgeon to perform the adapted maneuver,
clearly avoiding the occurrence of postoperative neurological defect in 5 of the
6 cases. CONCLUSION: NMEP monitoring is a sensitive and specific method useful
for detecting an impending lesion of the spinal cord. NMEPs are also helpful in
localizing the spinal level of the lesion. They represent a primary choice tool
for neuromonitoring during scoliosis surgery.
PMID- 10669825
TI - [Surgical treatment of hallux valgus in children and adolescents: 46 cases
treated with the Mitchell technique].
AB - PURPOSE OF THE STUDY: The aim of this study is to discuss special features of
hallux valgus in children and assess place of a surgical procedure in some
patients. MATERIAL AND METHOD: A retrospective study of 40 children (46 feet)
operated for hallux valgus was conducted. An etiology was identified in 10 per
cent of cases and 90 per cent were considered as idiopathic. From a clinical and
radiological analysis of 46 feet, we describe the anatomical particularities and
the indications of the surgical treatment. The Mitchell's technique is described
in detail. The correction of the metatarsal varus and the metatarsophalangial
valgus was obtained without breaking off the growth plate of the first
metatarsus. RESULTS: Clinically, results were satisfactory in 84 per cent of the
cases. Radiologically, results were excellents in 45 per cent and good in 35 per
cent. DISCUSSION AND CONCLUSION: Hallux valgus in the child is often
underestimated; operative treatment should be proposed in some patients.
Mitchell's technique gives good results with an early and simply correction.
PMID- 10669826
TI - [Primary leiomyosarcoma of bone. Report of 5 anatomo-clinical cases and review of
the literature].
AB - INTRODUCTION: Leiomyosarcoma is a malignant smooth muscle tumor occurring most
frequently in uterus or soft tissues and more rarely in bone. MATERIALS AND
METHODS: We report the clinicopathologic, immunohistochemical and ultrastructural
findings of five cases of primary leiomyosarcoma of bone treated in our
Department between 1991 and 1994. The pertinent medical literature is discussed.
RESULTS: The tumors were located respectively in the distal tibia (n=2), the
distal femur, the sternum and the ilium (n=1). Four lesions were high-grade and
one low-grade. All patients (3 women and 2 men) underwent wide surgical resection
associated with polychemotherapy in four cases. Two patients died of metastatic
disease, two had local recurrence and one is alive with no evidence of disease at
the last follow-up. DISCUSSION: Excluding cases which involve the facial
skeleton, there are to our knowledge 95 cases of primary leiomyosarcoma of bone
reported in the literature. This tumor arises more commonly in adults (mean age:
49 years) with an equal gender distribution and involves predominantly the long
bones near the knee. In the majority of cases, plain X-rays exhibit an osteolytic
lesion with cortical penetration and indistinct margins. The diagnosis is based
on microscopic features demonstrating fusiform tumor cells arranged in interwoven
bundles, and the immunohistochemical results of widespread cytoplasmic positivity
for smooth muscle actin. The best pronostic parameter is the histologic grade
correlated with both the recurrence and metastatic rates as well as the survival
rate. Surgery constitutes the main treatment since chemotherapy or radiotherapy
did not provide an improved prognosis over a wide resection.
PMID- 10669827
TI - [Pseudotumoral subacute osteomyelitis: a series of 41 children].
AB - PURPOSE OF THE STUDY: To confirm that subacute osteomyelitis in children is a
real entity, and give the main characteristics of this disease MATERIAL AND
METHODS: We reviewed 41 cases as well as the litterature. RESULTS: Pain without
fever was the only constant symptom. The erythrocyte sedimentation rate was
increased slightly. XRays were the most important investigation, showing a geode
in the metaphysis or more rarely in the epiphysis evoking a benign bone tumor in
a child. DISCUSSION: The treatment was most often surgical: scraping permits the
isolation of the microbe in 50 per cent of cases (staphylococcus most often) and
usualy leady to recovery. CONCLUSION: This form of osteomyelitis is relatively
frequent and must be discussed in front of a cystic tumoral image of the child's
long bone.
PMID- 10669828
TI - [Primary carpal bone defect].
AB - We present a review of management options in case of carpal bone defect, a
relatively frequent discovery. In the literature, diagnosis is usually a
fortuitous radiographic finding showing one or several images of carpal defect.
Pain is observed in some cases, more exceptionally pathological fracture. The
scaphoid, lunatum and hamatum are most frequently involved. Bilateral defects may
be observed. Different mechanisms have been put forward to explain the
development of intraosseous defects in the carpal bones including intraosseous
penetration of synovial tissue, or in situ metaplasia of bone tissue. The main
differential diagnoses are osteonecrosis sequellae (for the lunatum and the
scaphoid), subchondral defects due to hyperpression and arthropathies in dialysis
patients. All authors propose simple surveillance for asymptomatic images. In
case of pain, with soft tissue swelling or pathological fractures, filling
excision is warranted depending on the severity of the clinical signs. Prognosis
is generally good and recurrence exceptional.
PMID- 10669829
TI - [Extravasation injuries and subcutaneous aspiration in children].
AB - Complications of extravasation of intravenous fluid are not rare in pediatric
practice, and their local (skin necrosis) and regional (vasculo nervous)
implications can be severe. Two cases are presented in order to discuss the
different treatments options and to describe the subcutaneous aspiration
technique, which can be immediately efficient if proposed in a short delay.
PMID- 10669830
TI - [Double dislocation of the fifth metacarpal. A case report and review of the
literature].
AB - A case of traumatic double dislocation of the fifth metacarpal is reported. Both
dislocations, hamatometacarpal and metacarpophalangeal, were dorsal. This rare
combination of injury has been reported twice only. Our case was managed
successfully by closed reduction and immobilization. Eight month later, the
patient had a full range of wrist and finger movement, he was pain-free without
any residual disability.
PMID- 10669831
TI - [Aggressive osteoblastoma of the carpal scaphoid bone].
AB - We report a case of aggressive osteoblastoma of the scaphoid bone and discuss the
features of this tumor. The few reported cases emphazise the rarity of
osteoblastoma in hand and wrist localizations. Pathological examination is
mandatory before treatment due to lack of distinctive clinical and radiological
features. In our case, the rapidiy aggressive progression, similar to a malignant
tumor, required radical treatment with scaphoidectomy.
PMID- 10669832
TI - [Elastofibroma in the scapular region. A case report and review of the
literature].
AB - PURPOSE OF THE STUDY: We report a case of elastofibroma and have collected 280
cases in the literature. MATERIAL AND METHODS: A 56 year-old man presented with a
right subscapular mass. The patient was asymptomatic but he reported a
"clicking"sensation associated with mobilization of the shoulder. Physical
examination revealed a round mass clearly demonstrated with forward elevation of
the arm. The MRI scan showed a heterogeneous soft tissue composed of
inhomogeneous density with areas of more intense signal suggesting adipose
tissue. The tumor was surgically excised and the diagnosis of elastofibroma was
established by histopathologic examination. RESULTS: Six months after removal of
the mass, there were no functional complications. DISCUSSION: Elastofibromas
usually occur in active patients generally older than 55 years of age. They are
typically located in the right subscapular region. The tumor remains asymptomatic
in more than 50 percent of cases. 25 percent of the patients may report a simple
discomfort sometimes with a "clicking" or "catching" sensation associated with
mobilization of the arm. Pain is present in less than 10 percent of cases.
Physical examination may reveal a rubbery, asymptomatic mass located in the
subscapular region and barely noticable when the arm lies again the chest. Plain
radiographs and preoperative laboratory data were unremarkable. CT scan or MRI
scan may show an heterogeneous fibrous mass of intermediate density with
entrapped signals of higher intensity. However, a definitive diagnosis requires a
biopsy showing the distinctive feature of elastofibroma: elastic fibers in a
collagenized fibrous tissue with entrapped adipose tissue. Pathogenesis of
elastofibromas may result from the friction of the scapula against the thorax
thus generating tumor growth. CONCLUSION: Complete surgical excision in
symptomatic patients is considered to be the treatment of choice. However, once
the diagnosis of elastofibroma has been established, excision of lesions smaller
than 5 cm can be avoided in asymptomatic patients.
PMID- 10669833
TI - [Re: "Cadaver study of acetabular cup mobility in the healthy hip and hip
prosthesis by monopodal pressure simulation"].
PMID- 10669835
TI - [Pierre teinturier] [In Process Citation]
PMID- 10669834
TI - [Re: "Free musculo-tendinous flap stabilization-interposition of the palmaris
longus tendon after trapezium surgery in rhizoarthrosis].
PMID- 10669837
TI - Epithelial-mesenchymal interactions in the pathogenesis of asthma.
AB - During lung development, repair, and inflammation, local production of cytokines
(eg, transforming growth factor-beta) and growth factors (eg, epidermal growth
factor) by epithelial and mesenchymal cells mediate bidirectional growth control
effectively creating an epithelial-mesenchymal trophic unit. In asthma the
bronchial epithelium is highly abnormal, with structural changes involving
separation of columnar cells from their basal attachments and functional changes
including increased expression and release of proinflammatory cytokines, growth
factors, and mediator-generating enzymes. Beneath this damaged structure there is
an increase in the number of subepithelial myofibroblasts that deposit
interstitial collagens causing thickening and increased density of the
subepithelial basement membrane. Our recent studies suggest that the extent of
epithelial damage in asthma may be the result of impaired epidermal growth factor
receptor-mediated repair. In view of the close spatial relationship between the
damaged epithelium and the underlying myofibroblasts, we propose that impaired
epithelial repair cooperates with the T(H)2 environment to shift the set point
for communication within the trophic unit. This leads to myofibroblast
activation, excessive matrix deposition, and production of mediators that
propagate and amplify the remodeling responses throughout the airway wall.
PMID- 10669838
TI - Parasites and asthma/allergy: what is the relationship?
AB - Asthma prevalence is increasing in Western industrialized countries. The
infectious theory of asthma onset hypothesizes that lower levels of IL-12 result
in reduced T(H)1 stimulation and failure of the neonate to deviate from its T(H)2
bias at birth. Helminthic infections may influence T(H)2 immune responses and
hence immune development. Although ecologic data would support a protective
effect of parasitic infection on asthma development, this may be due to other
exposures. To date, there is no conclusive evidence that parasitic infection
protects against asthma development.
PMID- 10669840
TI - Urbanization and childhood asthma: an African perspective.
AB - The increasing prevalence of childhood asthma in the developed world is a cause
for concern. Much research is currently being conducted in an attempt to identify
possible reasons for this occurrence. A so-called Western lifestyle has been the
factor most commonly cited to explain this worrying increase in asthma
prevalence. In essence, this implies a way of life where children are exposed
from early infancy to a wide range of foods, infections, indoor and outdoor
allergens, and irritants and to the effects of motor vehicle pollution. Until
fairly recently, children in many African countries lived mainly in rural areas
and were not exposed to the effects of a Western lifestyle. Early studies in a
limited number of African countries showed a very low rural prevalence of
childhood asthma, especially where children lived according to a traditional
lifestyle. These same studies showed that asthma was not uncommon in urbanized
African children. There has been an increasing tendency over the past 20 years
for those in rural communities to move to the large urban centers. More recent
childhood asthma prevalence studies, especially those from Kenya and Ghana, have
confirmed the urban-rural differences but have shown a much narrower gap. In part
this may be the result of exposure of rural children to agricultural pesticides
and irritants as well as of an increasing tendency to adopt a more Westernized
lifestyle such as the use of beds with mattresses, pillows, and blankets. These
circumstances on the African continent provide a natural laboratory in the quest
for factors that influence the development of asthma in susceptible children.
Once more fully elucidated, it is possible that much valuable information will be
available to combat the relentless increase in childhood asthma both here as well
as in the developed world.
PMID- 10669839
TI - Molecular pathology of allergic disease. II: Upper airway disease.
AB - Allergic upper airway diseases such as allergic rhinitis and chronic sinusitis
are an increasing problem. Although the pathogenesis remains elusive, an
individual's genetic predisposition as well as exposure to the allergen are
currently considered factors in their development. Clinical symptoms of sneezing,
rhinorrhea, and congestion are primarily a consequence of granulocyte release of
chemical mediators such as histamine, prostanoids, and leukotrienes as well as
the infiltration of inflammatory cells. Observations subsequent to allergen
provocation are comparable to natural exposure and as such much of our
understanding of allergic responses is derived from this model. A prominence of
CD4(+) T cells and eosinophils, synthesis and release of T(H)2 cytokines, and the
coordinate expression of chemokines and adhesion molecules are all characteristic
of the allergic response observed in rhinitis and sinusitis. Corticosteroids and
immunotherapy target these inflammatory processes and have been observed to
successfully reduce and shift the predominantly T(H)2 environment toward T(H)1
cytokine expression. As our understanding of the pathophysiologic features of
allergic upper airway disease improves, as well as the relationship between their
development and that of lower airway disease, new strategies of diagnosis and
treatment will allow for more effective modulation of the allergic process and
associated morbidity.
PMID- 10669841
TI - IL-11 expression is increased in severe asthma: association with epithelial cells
and eosinophils.
AB - BACKGROUND: IL-11 is a pleiotropic cytokine produced by a variety of stromal
cells. Targeted overexpression of this cytokine in mice results in a remodeling
of the airways and the development of airway hyperresponsiveness and airway
obstruction. OBJECTIVES: Because these alterations mimic important pathologic and
physiologic changes in the airways of some asthmatic patients, we investigated
the expression of IL-11 messenger RNA (mRNA) within the airways of patients with
mild to severe asthma and nonasthmatic control subjects. METHODS: Fiberoptic
bronchoscopy to obtain bronchial biopsy specimens was performed on patients with
mild (n = 13), moderate (n = 10), and severe (n = 9) asthma and on nonasthmatic
control subjects (n = 9). RESULTS: These patients differed in their extent of
airway fibrosis with types I and III collagens being noted in greater quantities
in the biopsy specimens from the severe and moderate asthmatics than in those
from controls (P <.05). IL-11 mRNA expression was observed in the epithelial and
subepithelial layers of asthmatic and nonasthmatic control subjects. The number
of cells within the epithelium and subepithelium expressing IL-11 mRNA was
greater in those with moderate and severe asthma compared with mild asthma and
nonasthmatic subjects (P <.001). There were also greater numbers of IL-11 mRNA
positive cells within the subepithelium in severe compared with moderate asthma
(P <.001). Immunostaining for IL-11 within the airway tissues confirmed
translation of the mRNA into IL-11-immunoreactive protein in airway epithelial
cells. Colocalization of IL-11 mRNA and immunoreactivity with resident
inflammatory cells demonstrated that this cytokine was also expressed by major
basic protein-positive eosinophils. CONCLUSION: These results suggest that IL-11
is involved in the chronic remodeling seen in asthmatic airways and is associated
with increasing severity of the disease.
PMID- 10669842
TI - Bronchoalveolar lavage in bronchiolitis obliterans organizing pneumonia primed by
radiation therapy to the breast.
AB - BACKGROUND: Growing evidence indicates that unilateral lung irradiation for
breast cancer may "prime" the development of migratory lung infiltrates with
histologic features of bronchiolitis obliterans organizing pneumonia. OBJECTIVE:
Our purpose was to evaluate the cytologic and immunocytologic features of
bronchoalveolar lavage in this condition. METHODS: We analyzed the profile
bronchoalveolar lavage cell differentials and lymphocyte subpopulations of 11
women with bronchiolitis obliterans organizing pneumonia syndrome after radiation
therapy for breast cancer in comparison to 9 healthy women. RESULTS: The
bronchoalveolar lavage analysis demonstrated a significant increase in the
percentage of lymphocytes (36.7% +/- 5.4% vs 8.6% +/- 1.1%, P =.0002),
neutrophils (3.8% +/- 1.2% vs 0.6% +/- 0.2%, P =.005), eosinophils (2.4% +/- 1%
vs 0.3% +/- 0.1%, P =.01), and mast cells (1.4% +/- 0.6% vs 0.1% +/- 0.02%, P
=.05) with a significant decrease in the percentage of macrophages (56.1% +/- 6%
vs 90.3% +/- 1.4%, P =.0002) in patients with bronchiolitis obliterans organizing
pneumonia compared with the control subjects. The percentage of CD3(+) cells was
significantly increased in patients with bronchiolitis obliterans organizing
pneumonia (93.7% +/- 1.3% vs 70.9% +/- 4%, P =.0004), with a significant decrease
in CD4(+) cells (32.7% +/- 4.7% vs 55.4% +/- 2. 6%, P =.002) and a significant
increase in CD8(+) cells (61.2% +/- 4. 8% vs 37.5% +/- 2.9%, P =.003) in
comparison to control subjects. The CD4/CD8 ratio was significantly reduced in
patients with bronchiolitis obliterans organizing pneumonia compared with control
subjects (0.6% +/- 0.1% vs 1.5% +/- 0.1%, P =.001). CONCLUSION: These data add to
the view that unilateral lung irradiation for breast cancer may "prime" the
development of a syndrome quite similar to idiopathic bronchiolitis obliterans
organizing pneumonia.
PMID- 10669843
TI - Evaluation of a short form for measuring health-related quality of life among
pediatric asthma patients.
AB - BACKGROUND: This study was undertaken to derive and validate a short form parent
completed questionnaire to measure health-related quality of life (HRQL) in
pediatric asthma patients. OBJECTIVE: The objectives of this study were to (1)
use stepwise analysis to derive a shorter questionnaire from the original long
form questionnaire and (2) determine the tradeoff in precision between the long-
and short-form surveys. METHODS: One hundred eighty-one pediatric asthma patients
were enrolled from 4 sites. A parent of each patient completed a general and an
asthma-specific questionnaire during routine office visits from June 1995 to
January 1997. The questionnaire included the Child Health Questionnaire Parent
Form 50, a general HRQL survey, and a 17-item asthma-specific battery assessing
daytime symptoms, nighttime symptoms, and functional limitations. All scales were
scored from 0 to 100, with higher scores indicating better HRQL. Analysis of
variance models were used to derive short-form scales from the 17-item long-form
scales, and the final asthma-specific short-form scale structure was confirmed
with use of stepwise regression. Scale reliability was assessed with Cronbach's
alpha. Validity of the short-form questionnaire was assessed by comparing mean
scale scores according to the level of asthma severity defined by several
clinical criteria. Asthma severity was assessed with use of percent predicted
FEV(1), frequency and type of symptoms, parent rating of disease severity,
physician rating of disease severity, and resource use (emergency department use
and hospitalizations). The relative validity of each of the short-form scales was
measured by comparing the proportion of variance explained by each of the short
form scales compared with the respective long-form scales. RESULTS: The 17-item
asthma-specific battery was reduced to 8 items, the Integrated Therapeutics Group
Child Asthma Short Form. The daytime and nighttime symptom scales for each
contain 2 items and the functional limitations scale 4 items. Reliability was
greater than 0.70 for each of the short-form scales. The absence of ceiling and
floor effects indicates each scale's ability to detect changes at both low and
high levels of functioning. Lower (poorer) mean HRQL scores for severe cases
compared with mild cases, for all disease severity indicators, demonstrated
clinical validity. Relative validity estimates, comparing the proportion of
explained variance of the short-form scales with that of the long-form scales,
ranged from 0. 85 to 1.20, indicating a similar ability to measure change.
CONCLUSIONS: This study documents the development of a brief, multidimensional, 8
item questionnaire for measuring HRQL in pediatric asthma patients. The brevity
of the questionnaire makes it practical for use in practice settings and to
monitor patients.
PMID- 10669844
TI - Manchester Asthma and Allergy Study: low-allergen environment can be achieved and
maintained during pregnancy and in early life.
AB - BACKGROUND: Early exposure to dust mite allergens may be critical for primary
sensitization. Reducing exposure may offer a realistic chance for primary
prevention of sensitization and asthma, but it is essential to implement measures
that can achieve and maintain the low-allergen environment. OBJECTIVE: Our
purpose was to assess the effectiveness of mite allergen avoidance measures in
achieving and maintaining a low-allergen environment during pregnancy and in the
first year of life. METHODS: The Manchester Asthma and Allergy Study is a
prospective, prenatally randomized study that follows the development of asthma
and atopy in a cohort of infants at high risk (both parents atopic) who are
randomly allocated to full mite allergen avoidance or to a normal regimen.
Avoidance measures comprise (1) mite-proof covers (mattress, pillow, and quilt)
for parental bed, (2) high-filtration vacuum cleaner, (3) vinyl flooring in
infant's bedroom, (4) new crib and portable crib mattresses encased in mite-proof
material, (5) benzyl benzoate (Acarosan) applied on carpets and soft furniture,
(6) bed linens washed in hot water weekly, and (7) washable soft toys. Dust
samples from the parental bed, bedroom floor, living room floor, infant's
mattress, and nursery floor were collected between the 10th and 14th weeks of
pregnancy, immediately after birth, and then at age 6 months and 1 year, and Der
p 1 levels were determined by mAb-based ELISA. RESULTS: Recovered Der p 1 from
maternal mattress was reduced by 97. 25% (95% confidence interval [CI] 95.25%
98.41%) during the second and third trimesters of pregnancy, with the effect
persisting for 6 months (98% reduction, 95% CI 97.25%-99.1%) and 12 months (97.6%
reduction, 95% CI 95.7%-98.6%) after the birth (active vs control, P <.000001).
Total Der p 1 from bedroom floor in the active group was reduced by 53.7% (95% CI
25.7%-71.2%) in samples collected within 4 weeks of the child's birth, with the
percentage reduction being 62. 8% (95% CI 39.3%-77.2%) at 6 months and 26.5% (95%
CI -24% to 57.1%) at 1 year (active compared vs control, P <.007). Der p 1 levels
in crib mattress and nursery floor in the active group were extremely low (crib
mattresses geometric mean [95% CI] 2.3 ng [1.6-3.4] at birth, 6.8 ng [4.5-10] at
age 6 months, and 15.6 ng [9.8-24.8] at age 1 year [active vs control, P =.001];
nursery 1 ng [0.9-1.1] at birth, 1.7 ng [1.2-2.5] at age 6 months, and 2 ng [1.3
3.5] at age 1 year [active vs control, P <.00001]). The total amount of allergen
recovered at age 1 year was 29-fold (95% CI 15.1- to 56.7-fold) higher in the
control group than in the active group. CONCLUSIONS: The avoidance measures used
in this study achieved and maintained a low mite allergen environment during
pregnancy and in the first year of life in homes of infants at risk of atopy.
PMID- 10669845
TI - Longitudinal growth in infants and young children treated with budesonide
inhalation suspension for persistent asthma.
AB - BACKGROUND: Results of recent growth studies suggest that inhaled
glucocorticosteroids may affect growth in children. OBJECTIVE: Three 52-week,
open-label extension studies (studies A, B, and C) were conducted to compare the
effects of budesonide inhalation suspension (BIS) with conventional asthma
therapy (CAT) on long-term safety, including intermediate-term growth, in 3
different pediatric asthma populations. METHODS: Pediatric asthma patients (ages
6 months to 8 years) from 3 multicenter, randomized, 12-week, double-blind,
placebo-controlled studies were eligible to enroll in the 52-week, open-label
extension studies. The extension studies were multicenter, randomized, open
label, active-controlled, parallel-group studies performed at 26 centers in the
United States. Subjects in each extension study were randomized in a 2:1 ratio to
receive either BIS or CAT. BIS was initially administered at a dose of 0.5 mg
once (studies A and C) or twice daily (study B), with attempts made at each
clinical visit to gradually reduce the dose to the minimum effective dose that
maintains asthma control, as judged by the investigator. CAT consisted of any
available therapy for asthma, including inhaled glucocorticosteroids in studies B
and C only. Height SD scores, growth velocity, and skeletal age (only in studies
B and C) were examined. RESULTS: In total, 670 subjects were randomized; 223
subjects received CAT and 447 received BIS. Mean ages at entry were 63.0 months
and 60.9 months in CAT and BIS groups, respectively. Median total daily doses of
BIS ranged from 0.5 to 1. 0 mg and the mean duration of treatment exposure was
304 +/- 119 days and 342 +/- 83 days in CAT and BIS groups, respectively. Changes
in height SD scores differed significantly between the BIS and CAT groups in
study A (-0.19, P =.003), and there was a small, statistically significant
decrease in growth velocity (-0.8 cm/y, P =.002) in the BIS-treated group
compared with the CAT group. No significant differences were observed between BIS
and CAT groups in the changes in height SD scores or in growth velocities in
studies B (+0.10 and +0.7 cm/y, respectively) and C (+0.12 and +0.8 cm/y,
respectively). No differences in skeletal age were observed between BIS and CAT
groups in studies B and C. CONCLUSION: There was a small, statistically
significant decrease in growth velocity in the BIS-treated group compared with
the CAT group in the study (study A) where inhaled glucocorticosteroid use was
prohibited before entry and in the CAT group during the study. In the studies (B
and C) where inhaled glucocorticosteroids were allowed in the CAT group, no
differences were observed in height SD scores or growth velocity. The clinical
relevance of these effects, including impact on final adult height, remain to be
determined in prospectively planned studies that assess growth in children.
PMID- 10669846
TI - Carbon monoxide is endogenously produced in the human nose and paranasal sinuses.
AB - BACKGROUND: Carbon monoxide (CO) has recently emerged as an endogenously produced
gaseous mediator that, like nitric oxide (NO), appears to be involved in both
upper and lower airway inflammation. In healthy subjects a large part of the
exhaled NO seems to originate from the nasal airways, and the paranasal sinuses
have been described as a dominating site for NO production. OBJECTIVE: The
current study was designed to investigate whether CO could also be produced in
the nose and paranasal sinuses. METHODS: The occurrence in the nasal mucosa of
the enzyme heme oxygenase, the rate limiting step for CO production, was analyzed
with use of immunocytochemistry. CO in exhaled and sampled air was measured with
an infrared analyzer. Forty-two healthy subjects and two patients with a
tracheostoma volunteered for the study. RESULTS: Heme oxygenase-like
immunoreactivity was seen in the respiratory epithelium, in connection with
seromucous glands and in the vascular smooth muscle of the nose. When CO was
continuously sampled from one nostril during normal breathing through the mouth,
stable levels of CO could be measured within 40 seconds in all subjects tested (n
= 33). Repeated measurements indicated only minor variations in the values
obtained. Sampling through a drainage tube inserted into the maxillary sinus
revealed CO levels comparable to the levels obtained by sampling through the nose
(n = 6). Breathing through the nose increased the CO levels obtained in the
exhaled air (n = 33, P <. 001). CONCLUSION: These results imply that the nose and
paranasal sinuses contribute to the CO production of the human airways.
PMID- 10669847
TI - Does allergy in parents depend on allergy in their children? Recall bias in
parental questioning of atopic diseases. Multicenter Allergy Study Group.
AB - BACKGROUND: A positive atopic family history has proved to be one important risk
factor for the development of atopic diseases in offspring. However, many
epidemiologists are concerned about the accuracy and reliability of data because
responses to questionnaires can be biased for many reasons. OBJECTIVE: The study
investigated whether responses of parents questioned about their atopic diseases
change depending on the development of atopic symptoms in their children.
METHODS: During a prospective birth cohort study on atopy in children (the
Multicenter Allergy Study) parents filled out questionnaires twice within 2 years
about their atopic diseases. Differences between the 2 responses were examined by
log-linear and logistic regression models depending on the diagnosed atopy status
of the study children. RESULTS: Mothers tended to report more atopic diseases in
the second questioning than in the first, indicating a nondifferential
misclassification. Fathers were influenced by the development of atopic diseases
in their children: they reported significantly more atopic diseases if the child
developed atopic illness with atopic dermatitis. CONCLUSION: In parental
questioning about atopic diseases, a recall bias must be considered for the
association of atopic family history and atopy in children. Especially in case
control and cross-sectional studies, such misclassifications can result in biased
estimates of prognosis and risk factors.
PMID- 10669848
TI - Escherichia coli expression and purification of recombinant dog albumin, a cross
reactive animal allergen.
AB - BACKGROUND: Animal hair-dander represents an important source of indoor
allergens. Diagnosis and therapy of animal allergy would benefit from the
availability of defined recombinant allergens. They may be preferred to animal
derived proteins, particularly for in vivo application in patients. OBJECTIVE:
The purpose of this study was to express and purify recombinant dog albumin, an
important cross-reactive animal allergen. METHODS: Complementary (c)DNA sequences
coding for dog albumin were obtained by reverse transcription and subsequent PCR
amplification from dog liver RNA. Dog albumin-encoding cDNA sequences were
inserted into phage lambdagt11, and IgE-reactive phage clones were isolated by
immunoscreening with serum IgE from a patient with dog allergy. Dog albumin was
expressed as IgE-reactive recombinant protein in Escherichia coli and purified by
inclusion body preparation, resolubilization, and diethylaminoethyl cellulose
chromatography. Cross-reactivity of dog albumin with cat and human albumin was
examined by immunoblot, as well as ELISA inhibition experiments. RESULTS: A cDNA
sequence coding for complete dog albumin was obtained by reverse transcription
and subsequent PCR amplification from dog liver. The cDNA and deduced amino acid
sequence of dog albumin was highly homologous to the sequences of albumins from
animals to human subjects, thus explaining the extensive cross-reactivities among
albumins. Recombinant dog albumin was expressed in E coli and purified. It
reacted with serum IgE from patients allergic to dog albumin and a monoclonal
anti-human albumin antibody. Immunologic competition experiments performed with
serum IgE from patients allergic to dog albumin and a mouse monoclonal antihuman
albumin antibody indicated the presence of similar epitopes on dog, cat, and
human albumin. CONCLUSION: Recombinant dog albumin may be used for diagnostic
purposes to identify patients who are cross-sensitized to many animal species and
perhaps for specific immunotherapy of sensitized individuals.
PMID- 10669849
TI - Purification and characterization of an 18-kd allergen of birch (Betula
verrucosa) pollen: identification as a cyclophilin.
AB - BACKGROUND: Five birch pollen allergens have been identified so far. In a
previous study we detected new birch pollen allergens with an isoelectric point
in the range 9.0 to 9.3, present only in extracts prepared at controlled basic
pH. OBJECTIVE: The purpose of the current study was to purify and characterize
those allergens. METHODS: The target allergens were purified by ion exchange and
hydrophobic interaction chromatography. Analyses were carried out by SDS-PAGE,
isoelectric focusing, immunoblotting, and amino acid sequencing. The in vivo
reactivity of the allergens was evaluated by skin testing. RESULTS: An 18-kd
protein, which we named Bet v 7, was purified. This 18-kd protein corresponded to
3 bands on isoelectric-focusing immunoblots that probably represent isoforms. On
immunoblots up to 20.8% of birch pollen-allergic patients recognized those
allergens. The clinical relevance of Bet v 7 was demonstrated by positive
immediate-type skin testing on a patient allergic to birch pollen. Sequencing of
an internal peptide yielded an amino acid sequence showing high homology with
various plant cyclophilins. The rotamase activity of the protein, inhibited by
cyclosporin A, further confirmed that Bet v 7 belongs to the group of
cyclophilins. CONCLUSION: We have purified a novel allergen of birch pollen, Bet
v 7, belonging to the cyclophilin family. Because cyclophilins are highly
conserved proteins over the phylogeny, we may postulate that Bet v 7 is a member
of a new family of panallergens.
PMID- 10669850
TI - Genetic restrictions in olive pollen allergy.
AB - BACKGROUND: The major antigen of olive tree pollen, Ole e 1, produces an IgE
response restricted by DQ2. OBJECTIVE: Our purpose was to further analyze the
genetic restrictions associated with IgE and IgG antibodies against Ole e 1 and
IgE against the recently described antigen Ole e 3. METHODS: Twenty-two nuclear
olive pollen-allergic families (n = 88) were selected. DRB1 and DQB1, TCR-Valpha
8.1, the high-affinity receptor of IgE (FcepsilonRI-beta) Rsa I exon 7 and intron
2 and TNF-beta (LTalpha-Nco I) polymorphisms were determined by PCR and analyzed
for association with allergic traits by the multiallelic transmission
disequilibrium test. RESULTS: Significant associations were found among HLA
DQB1*0201 (n = 29) and high levels of IgG (P =.023) and IgE (P =.0136) antibodies
to Ole e 1 and with IgE specific to Ole e 3 (P =.0368). DRB1*0701 was associated
with high levels of total serum IgE (P =.04) and IgG against Ole e 1 (P =.025).
The FcepsilonRI-beta Rsa I exon 7, allele 1 (n = 39), was associated with high
levels of total serum IgE (P =. 01), IgE antibodies against Olea europaea extract
(P =.004), and specific antibodies to Ole e 1, IgG (P =.04), and IgE (P =.006).
The FcepsilonRI-beta Rsa I intron 2, allele 2 (n = 33), was associated with IgE
antibodies to O europaea extract (P =.003) and specific antibodies to Ole e 1,
IgG (P =.025), and IgE (P =.05). CONCLUSIONS: We found a new association between
IgE antibody response to Ole e 3 and DQB1*0201 and verified the previously
reported association between Ole e 1-specific response and DQB1*0201. Also, the
association between FcepsilonRI-beta and IgE antibodies against Ole e 1 was
demonstrated.
PMID- 10669851
TI - The role of IL-12 in the induction of late-phase cellular infiltration in a
murine model of allergic conjunctivitis.
AB - BACKGROUND: The applied murine model of allergic conjunctivitis mimics human
disease, and an immediate hypersensitivity reaction (IHR) and a late-phase
cellular reaction typically develop in sensitized mice after topical challenge
with the allergen. OBJECTIVE: We investigated the role of IL-4, IFN-gamma, and IL
12 in the early and late phases of ocular allergy with use of cytokine knockout
(KO) mice and neutralizing antibodies. METHODS: Ragweed-sensitized wild-type or
IL-4KO, IL-12KO, IFN-gamma KO, anti-IL-12 mAb-treated, recombinant murine IL-12
treated, and anti-IFN-gamma mAb-treated mice were challenged with the allergen 10
days after the immunization. IHR, cellular infiltration, lymphoproliferative
response, and cytokine production from draining lymph nodes were recorded and
compared among groups. RESULTS: We show that IL-12KO mice and anti-IL-12 antibody
treated wild-type animals failed to have a cellular infiltration into the
conjunctiva. Treatment with recombinant murine IL-12 also reduced the number of
infiltrating PMNs but increased the percentage of mononuclear cells in the
conjunctiva compared with controls. IFN-gamma KO mice had a significantly
stronger IHR and prolonged infiltration into the conjunctiva after challenge with
ragweed than controls. CONCLUSION: Our data suggest that the presence of IL-12,
although better known as a T(H)1-inducing cytokine, is important for the
development and the regulation of the late-phase pathologic features in ocular
allergy. Furthermore, IFN-gamma is a limiting factor in the late phase of allergy
and thus may be important in preventing chronic allergic disease.
PMID- 10669852
TI - Blood eosinophils from atopic donors express messenger RNA for the alpha, beta,
and gamma subunits of the high-affinity IgE receptor (Fc epsilon RI) and
intracellular, but not cell surface, alpha subunit protein.
AB - BACKGROUND: Blood eosinophils from hypereosinophilic donors were previously
reported to possess the functional high-affinity IgE receptor (Fc epsilon RI), so
providing a potential mechanism to account for eosinophil degranulation in atopic
allergic disease. Furthermore, tissue eosinophils from allergic tissue reactions
were shown to be mRNA(+) for the alpha, beta, and gamma subunits of Fc epsilon RI
and gave positive immunostaining with an anti-Fc epsilon RI-alpha antibody.
Recent studies, however, revealed negative surface staining on peripheral blood
eosinophils, but intracellular Fc epsilon RI-alpha protein was identified by
Western blot analysis. OBJECTIVE: Our purpose was to examine on peripheral blood
eosinophils from atopic subjects (1) surface expression and mRNA for Fc epsilon
RI-alpha, (2) up-regulation of Fc epsilon RI-alpha by allergy-associated tissue
factors, and (3) Fc epsilon RI-alpha-dependent release of eosinophil peroxidase
(EPO). METHODS: We measured (1) Fc epsilon RI mRNA expression by in situ
hybridization, (2) Fc epsilon RI-alpha by flow cytometry and immunocytochemistry
(with use of nonpermeabilized and permeabilized cells), and (3) Fc epsilon RI
alpha-dependent release of EPO. RESULTS: Eosinophils from atopic donors had
negligible surface expression of Fc epsilon RI-alpha, which was not enhanced by
culture with IgE, IL-3, IL-4, IL-5, GM-CSF, or fibronectin or coculture with
fibroblasts. Permeabilization, however, revealed appreciable intracellular
staining for Fc epsilon RI-alpha. The majority of eosinophils were mRNA(+) for
the alpha, beta, and gamma subunits of Fc epsilon RI. Small but significant (P
=.03) increases in alpha chain mRNA expression were observed after coculture of
eosinophils with fibroblasts but not with IgE, IL-4, or fibronectin. Cross
linking of Fc epsilon RI on the surface of eosinophils from atopic donors did not
lead to detectable EPO release. CONCLUSION: Human blood eosinophils express
negligible, nonfunctional membrane Fc epsilon RI-alpha but have intracellular Fc
epsilon RI-alpha protein and mRNA expression for the alpha, beta, and gamma
subunits.
PMID- 10669853
TI - Corticosteroids inhibit rhinovirus-induced intercellular adhesion molecule-1 up
regulation and promoter activation on respiratory epithelial cells.
AB - BACKGROUND: Rhinoviruses are associated with the majority of asthma
exacerbations. To date, the pathogenesis of virus-induced asthma exacerbations is
still unclear, and no safe effective therapy is available. Intercellular adhesion
molecule-1 (ICAM-1) has a central role in inflammatory cell recruitment to the
airways in asthma and is the receptor for 90% of rhinoviruses. We have previously
shown that rhinovirus infection of lower airway epithelium induces ICAM-1
expression by a transcriptional mechanism that is critically nuclear factor
kappaB-dependent. OBJECTIVE: The purpose of this study was to investigate the
effect of systemic (hydrocortisone [HC], dexamethasone [DM]) and topical
(mometasone furoate [MF]) corticosteroids on rhinovirus-induced ICAM-1 up
regulation. METHODS: Cultured primary bronchial or transformed (A549) respiratory
epithelial cells were pretreated with corticosteroids for 16 hours and infected
with rhinovirus type 16 for 8 hours. ICAM-1 surface expression was evaluated by
flow cytometry. In A549 cells ICAM-1 messenger RNA was evaluated by specific
reverse transcription-PCR and promoter activation by chloramphenicol
acetyltransferase assay. RESULTS: We observed inhibition of rhinovirus-induced
ICAM-1 up-regulation with corticosteroid pretreatment in both primary bronchial
epithelial and A549 cells. In A549 cells systemic and topical corticosteroids
demonstrated a dose-dependent inhibition with similar efficacy (inhibitory
concentration 50% 10(-10) mol/L, 10(-11) mol/L, and 10(-11) mol/L for HC, DM, and
MF respectively). MF also inhibited ICAM-1 messenger RNA induction by rhinovirus
infection in a dose-dependent manner. MF completely inhibited rhinovirus-induced
ICAM-1 promoter activation. HC, DM, and MF had no direct effect on rhinovirus
infectivity and replication in cultured cells. CONCLUSION: Corticosteroids
decrease rhinovirus-induced ICAM-1 up-regulation in respiratory epithelial cells
and modulate pretranscriptional mechanisms. This effect may be important for the
therapeutic control of virus-induced asthma exacerbations.
PMID- 10669854
TI - IL-4 production by PBMCs on stimulation with mite allergen is correlated with the
level of serum IgE antibody against mite in children with bronchial asthma.
AB - BACKGROUND: Although IL-4, IL-13, and IFN-gamma are known to affect IgE
synthesis, it remains unclear which one plays the most important role in in vivo
IgE synthesis in atopic patients. OBJECTIVE: The aim of this study is to clarify
the difference in importance among these cytokines in up-regulation of IgE
synthesis in atopic patients. METHODS: We measured IL-4, IL-13, and IFN-gamma
production by PBMCs on stimulation with house dust mite (HDM) in 23 children, 3
to 15 years old, with bronchial asthma (BA) and analyzed the correlation with HDM
specific IgE antibody levels expressed as HDM IgE radioallergosorbent test (RAST)
results. RESULTS: The production of IL-4 and IL-13 by PBMCs on stimulation with
HDM was significantly higher in children with BA than in nonatopic control
subjects (IL-4, 752.9 +/- 365.9 vs 312.3 +/- 230.0 fg/mL, P <.001; IL-13, 21.9
pg/ml [<12.0-77.6] vs <12.0, P <.01). IL-4 production showed a close positive
correlation with HDM IgE RAST (r = 0.71, P <.001), which was distinctly stronger
than that between IL-13 production and HDM IgE RAST (r = 0.46, P <.05). IFN-gamma
production was neither different between children with BA and nonatopic control
subjects (7. 24 [1.54-33.90] pg/mL vs 11.2 [1.66-75.9] pg/mL) nor correlated with
HDM IgE RAST levels. Essentially the same result was obtained by stimulation of
PBMCs with a purified HDM major allergen Der f 1. CONCLUSION: IL-4 is likely to
be the most important cytokine in up-regulation of in vivo IgE synthesis against
HDM in children with BA.
PMID- 10669856
TI - In vitro diagnosis of cypress pollen allergy by using cytofluorimetric analysis
of basophils (Basotest).
AB - BACKGROUND: Cupressaceae pollen allergy is a worldwide pollinosis, but its in
vitro diagnosis is notoriously difficult. The Basotest is a newly available in
vitro test for the detection of allergen-specific IgE based on the level of
cellular activation of basophils by using flow cytometry. OBJECTIVES: The
Basotest was compared with the measurement of cypress pollen-specific IgE in
highly selected patients. METHODS: We analyzed 34 patients allergic to cypress
pollen selected on the basis of a suggestive clinical history and positive skin
test and nasal challenge responses to cypress pollen extract. We also analyzed 8
patients with positive skin test responses to cypress pollen extract who did not
present symptoms during the pollen season (intermediate group) and 33 control
subjects. Sensitivity, specificity, and efficiency of the Basotest and serum
specific IgE levels measured by using the CAP System were determined in patients
allergic to cypress pollen. Histamine release was studied in a selected group of
patients. RESULTS: The Basotest was more sensitive (91.2%) than the CAP System
(76%) for the in vitro diagnosis of cypress pollen allergy. A dose-response curve
was observed in basophils obtained from patients allergic to cypress pollen.
There were no false-positive results with either test (specificity 100%). The
results of the Basotest or those of the CAP System did not correlate with the
patients' in vivo threshold sensitivity assessed by skin tests and nasal
challenge. CONCLUSIONS: The Basotest was found to be an effective diagnostic test
in patients allergic to cypress pollen.
PMID- 10669855
TI - Chemokine- and cytokine-induced expression of endothelin 1 and endothelin
converting enzyme 1 in endothelial cells.
AB - BACKGROUND: Endothelin 1 (ET-1) is a product of endothelial and many other cell
types that possesses a wide range of actions, including vasoconstriction,
bronchoconstriction, and mitogenic activity on smooth muscle cells and
fibroblasts. ET-1 release and expression is induced in several disease conditions
associated with inflammation and cellular injury. OBJECTIVE: The purpose of this
study is to determine the effects of alpha-chemokines (IL-8 and melanoma growth
stimulating activator), beta-chemokines (monocyte chemotactic protein 1,
macrophage inflammatory protein 1alpha [MIP-1alpha], MIP-1beta, and RANTES), and
proinflammatory cytokines (IL-1beta, TNF-alpha, and IFN-gamma) on the expression
of both ET-1 and endothelin-converting enzyme 1 (ECE-1) by human umbilical vein
endothelial cells. METHODS: Subconfluent monolayers of human umbilical vein
endothelial cells were incubated with each chemokine individually for 24 hours or
with a mixture (cytomix) of TNF-alpha, IL-1beta, and IFN-gamma for 6 and 24
hours. RESULTS: Incubation with the alpha-chemokines melanoma growth-stimulating
activity and IL-8 did not significantly increase ET-1 and ECE-1 messenger (m)RNA
expression and had no effect on ET-1 release. Monocyte chemotactic protein 1
exerted the most potent increase in ET-1 and ECE-1 mRNA and ET-1 release among
all chemokines studied (P <.05). MIP-1alpha and RANTES exerted a moderate, but
significant, increase on the ET system (P <.05). The cytomix resulted in a
significant increase in ET-1 and ECE-1 mRNA expression (P <.05). CONCLUSION:
These data demonstrate that, like cytokines, chemokines can induce endothelial ET
1 and ECE-1 in vitro and suggest a possible role for these inflammatory mediators
in the induction of the ET system in inflammatory and vascular diseases.
PMID- 10669857
TI - Helper T-cell responses elicited by Der p 1-pulsed dendritic cells and
recombinant IL-12 in atopic and healthy subjects.
AB - BACKGROUND: Environmental allergens, such as Dermatophagoides pteronyssinus group
1 antigen (Der p 1), induce T(H2)-type responses in atopic patients, whereas
healthy individuals have T(H1)-type responses to the same antigens. Because of
their efficient synthesis of IL-12, dendritic cells (DCs) are potent inducers of
T(H1)-type immune responses. OBJECTIVE: We sought to determine whether DCs would
skew allergen-specific T(H2)-type responses from atopic individuals. METHODS:
Purified CD4(+) T cells from healthy donors or atopic individuals were cultured
in the absence or presence of recombinant (r)IL-12 with DCs derived from PBMCs
and pulsed with Der p 1. Supernatants of DC-T cell cocultures were assayed by
ELISA for IL-5 and IFN-gamma. RESULTS: A T(H1)-type response developed in
purified CD4(+) T cells from healthy donors in response to Der p 1-pulsed DCs, as
indicated by high levels of IFN-gamma in culture supernatants. In contrast,
CD4(+) T cells from atopic donors displayed a T(H2)-type profile characterized by
high levels of IL-5 and low levels of IFN-gamma. The addition of rIL-12 (10
ng/mL) to DC-T cell cocultures resulted in the induction of IFN-gamma secretion
by Der p 1-specific CD4(+) T cells from atopic patients, whereas their production
of IL-5 was not inhibited. Using flow cytometry after intracytoplasmic staining,
we found that IFN-gamma and IL-5 were secreted by distinct CD4(+) T-cell
subpopulations. CONCLUSION: The cytokine profile of Der p 1-specific T(H2)-like
cells from atopic individuals is maintained when the allergen is presented by
DCs, even in the presence of exogenous rIL-12.
PMID- 10669858
TI - Urinary eosinophil protein X and serum eosinophil cationic protein in infants and
young children with atopic dermatitis: correlation with disease activity.
AB - BACKGROUND: Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) or
eosinophil-derived neurotoxin (EDN) are released by eosinophil granulocytes in
allergic diseases. Serum ECP (s-ECP) levels have been correlated with disease
activity in atopic dermatitis (AD) in adults and young patients, and high urinary
EPX (u-EPX) levels in asthmatic patients seem to reflect active disease. A
relationship between AD severity and u-EPX concentration in young children has
not been previously studied. OBJECTIVE: This study was performed to evaluate
whether the severity of AD in infants and young children was correlated with s
ECP and u-EPX levels. METHODS: Fifty-four infants and children (mean age, 17.7
months; range, 4-48 months) with AD and without other allergic conditions were
evaluated. The severity of AD was measured by using the SCORAD index. S-ECP,
serum total IgE, serum-specific IgE for common allergens, and peripheral blood
eosinophil counts (PBECs) were determined. In forty-two children u-EPX was also
measured. Seven age-matched control patients underwent the same determinations.
RESULTS: S-ECP and u-EPX were significantly higher in children with AD than in
control children (mean, 23.9 vs 3.5 microg/dL [P <.001] and 57.7 vs 6.0
microg/mmol creatinine [P <.001]). A significant correlation was found between
SCORAD and s-ECP (P =.002), u-EPX (P =.01), and PBECs (P =.01) and between
symptom index and uEPX (P =.0004). PBECs were strongly correlated to s-ECP and u
EPX (P <.0001). However, 5 patients with moderate and severe AD (11.9%) showed
low levels of s-ECP, u-EPX, and PBECs. CONCLUSION: S-ECP and u-EPX were useful
markers of AD activity in infants and young children. When taken together, the
two determinations could give more information about the clinical course of the
illness. Some patients seemed to have clinical exacerbations without an
involvement of eosinophils and their products.
PMID- 10669859
TI - Carbon dioxide inhalation challenges in idiopathic environmental intolerance.
AB - BACKGROUND: Idiopathic environmental intolerance (IEI) is associated with
unexplained physical symptoms, which overlap considerably with those of panic
disorder (PD). OBJECTIVE: This study tested the hypothesis that patients with
symptoms to suggest IEI exhibit features of PD in response to nonnoxious
environmental stimuli. METHODS: A single-blind, case-control 35% carbon dioxide
inhalation challenge was conducted at a university-based occupational health unit
with the use of standardized psychologic questionnaires involving 36 patients
with IEI and 37 healthy control subjects. The main outcome measures included
panic attack symptoms and scores on the Anxiety Sensitivity Index, a measure of
panic-related anxiety. RESULTS: Patients with IEI scored significantly higher on
the Anxiety Sensitivity Index than control subjects did (P <.05). Significantly
more patients with IEI (71%) than control subjects (26%) fulfilled panic attack
criteria after carbon dioxide (P <.001). Physiologic responses to the challenge
were not significantly different between groups. CONCLUSIONS: Results suggest
that, similar to patients with PD, patients with IEI display high anxiety
sensitivity and in response to carbon dioxide inhalation tend to experience
heightened anxiety and panic attacks.
PMID- 10669860
TI - Exposure-effect relationship of platinum salt allergy in a catalyst production
plant: conclusions from a 5-year prospective cohort study.
AB - BACKGROUND: There is a high incidence of occupational asthma and rhinitis caused
by platinum (Pt) salts in precious-metal refineries. OBJECTIVE: We sought to
assess exposure to Pt salts and the incidence of Pt salt allergy in a catalyst
production plant. METHODS: A 5-year prospective cohort study was performed in 159
catalyst production workers (94.6% of recruited), 50 craftsmen (92. 6% of
recruited), and 66 control subjects (76.7% of recruited) at yearly intervals.
Subjects were assigned to exposure categories of high levels of Pt (n = 115),
persistently low levels of Pt (n = 51), intermittently low levels of Pt (n = 61),
or no Pt (n = 48) after the initial survey according to job title and job
location. Skin prick test conversion from a negative response to a 4 mm or larger
wheal response with a 10(-2) mol/L hexachloroplatinic acid solution was chosen as
the outcome variable. RESULTS: Exposure assessment of airborne Pt and Pt in the
serum of workers demonstrated clear differences between exposure categories. The
threshold limit value of 2 microg/m(3) for soluble Pt was exceeded in 3 (4%) of
78 measurements. Thirteen subjects assigned to high exposure showed skin test
conversion, and new allergic symptoms were associated with exposure. Among the
high-exposure category, the incidence rate of skin prick test conversion was 5.9
per 100 person-years for newly employed subjects (n = 79) and 2.1 per 100 person
years for those who had already been employed at the time of the initial survey
(n = 36). A predicting factor for skin test conversion in highly exposed subjects
was smoking status (relative risk, 3.9; 95% confidence interval, 1.6-9.7) but not
atopy or bronchial hyperresponsiveness. CONCLUSION: Sensitization to Pt salts may
develop in workers of catalyst production plants. Both the exposure to Pt salts
and the incidence of Pt salt allergy were lower compared with reported data from
precious-metal refineries.
PMID- 10669861
TI - Evidence for a lipid transfer protein as the major allergen of apricot.
AB - BACKGROUND: Apricots are widely grown in Europe, and allergic reactions are
becoming more common, especially oral allergy syndrome. Apricot belongs to the
botanical subfamily of Prunoideae, which includes peach, the major allergen of
which was identified as a 9-kd protein, a lipid transfer protein (LTP).
OBJECTIVE: The aim of the study was to evaluate the IgE reactivity pattern to an
apricot extract in subjects with allergic reactions to apricot, as demonstrated
by a positive oral challenge response. METHODS: Thirty patients were
investigated. All the patients displayed oral allergy syndrome (2 with systemic
reactions) to apricot, with positive open food challenge responses, skin prick
test responses, and serum-specific IgE antibodies to apricot. The IgE reactivity
pattern to apricot extract was identified by using SDS-PAGE and immunoblotting.
The major allergen, a 9-kd protein, was then purified by HPLC and characterized
by periodic acid-Schiff stain, isoelectric point determination, and N-terminal
amino acid sequencing. RESULTS: The sera from all patients allergic to apricot
recognized the 9-kd protein, whereas none of the other allergens, with molecular
weights from 15 to 80 kd, acted as a major allergen. The 9-kd allergen has an
isoelectric point of 8.7 and is not glycosylated. Determination of the N-terminal
34 amino acid sequence showed that it belongs to the LTP family, with a 94%
homology with the LTP from peach. IgE blotting of the apricot extract was
completely inhibited by the 9-kd purified LTP from peach. CONCLUSIONS: The major
allergen of apricot is an LTP, which is highly cross-reactive with the LTP from
peach.
PMID- 10669862
TI - Mutational analysis of the IgE-binding epitopes of P34/Gly m Bd 30K.
AB - BACKGROUND: Peanuts and soybeans are 2 foods that have been shown to be
responsible for many atopic disorders. Because of their nutritional benefit,
soybean proteins are now being used increasingly in a number of food products.
Previous studies have documented multiple allergens in soybean extracts,
including glycinin, beta-conglycinin, and the P34/Gly m Bd 30K protein.
OBJECTIVE: Our overall goal was to identify soybean-specific allergens to begin
to understand molecular and immunochemical characteristics of legume proteins.
The specific aim of the current investigation was to identify the essential amino
acid residues necessary for IgE binding in the 5 distinct immunodominant epitopes
of P34/Gly m Bd 30K. METHODS: Serum IgE from 6 clinically sensitive soybean
allergic individuals was used to identify P34/Gly m Bd 30K in the native and
single amino acid substituted peptides with use of the SPOTS peptide synthesis
technique to determine critical amino acids required for IgE binding. RESULTS:
The intensity of IgE binding and epitope recognition by serum IgE from the
individuals varied substantially. With use of serum from 6 clinically soybean
sensitive individuals, 2 of the 5 immunodominant epitopes could be mutagenized to
non-IgE binding peptides. CONCLUSIONS: Single-site amino acid substitution of the
5 immunodominant epitopes of Gly m Bd 30K with alanine revealed that IgE binding
could be reduced or eliminated in epitopes 6 and 16 in the serum obtained from 6
soybean-sensitive patients.
PMID- 10669863
TI - Survey of patients after discontinuing venom immunotherapy.
AB - BACKGROUND: Venom immunotherapy rapidly reduces the risk of a systemic sting
reaction in adults from 30% to 70% to less than 2%. When venom immunotherapy is
stopped after 5 years or longer, the risk of a systemic sting reaction is 5% to
15% during the first few years after stopping treatment. It is uncertain whether
systemic sting reactions will occur more than 5 years after discontinuing venom
immunotherapy and whether treatment can be safely stopped in some patients after
less than 5 years. OBJECTIVE: The purpose of this study is to estimate the risk
of systemic reaction to a sting 10 years after discontinuing treatment and the
relative risk after 3 years of treatment compared with that after 5 years or more
of treatment. METHODS: Among all patients who had venom immunotherapy at our
center, we identified 395 patients who stopped treatment: some had dropped out of
therapy early (6-24 months), some stopped after 3 to 4 years, and most completed
5 years or more of venom immunotherapy and were advised to stop by the allergist
(many as part of our reported studies of discontinuing venom immunotherapy).
RESULTS: Contact was made with 194 patients, including telephone interviews for
sting history and requests to visit the office for skin testing and blood
sampling. Of these patients, 74 had been included in our original study of
patients who had 5 years or more of venom immunotherapy and had sting challenges
after 1 to 5 years off venom immunotherapy, as previously reported. Of the 74 in
that original study, 61 were reached for this survey, and 30 reported recent
stings, with 5 systemic sting reactions. Another 133 patients who had stopped
venom immunotherapy were reached: 82 had 5 or more years of venom immunotherapy,
20 had 3 to 4 years of venom immunotherapy, and 31 had less than 2 years of venom
immunotherapy. Of 51 patients stung from this group, 27 had 5 or more years of
venom immunotherapy (no systemic sting reactions), and 24 had less than 5 years
of venom immunotherapy (3 systemic sting reactions). We have now observed a total
of 113 patients who had 5 or more years of venom immunotherapy and were stung
after stopping. Sixteen (14%) had systemic sting reactions; most were mild, but 4
were severe. Systemic sting reactions occurred in 12 (10.7%) of 112 patients
stung in the first 4 years off venom immunotherapy and 5 (10%) of 50 stung more
than 5 years off venom immunotherapy. In 4 of 8 patients with current systemic
sting reactions, the skin test response was negative, although the venom-IgE
response was positive at the previous encounter. All systemic sting reactions
were similar in pattern and severity to prevenom immunotherapy reactions in the
same patient. CONCLUSIONS: We conclude that the risk of systemic sting reactions
when venom immunotherapy is stopped after 5 years or longer remains in the
reported range of 5% to 15% in the 5 to 10 years after stopping venom
immunotherapy. This risk of systemic sting reactions does not seem to decrease
over time, unlike the progressive decline in immunologic markers (skin test and
venom-IgE responses). To prospectively assess the risk of recurrent systemic
sting reactions, there is a need for sting challenge studies of patients who have
been off venom immunotherapy for 5 to 10 years and patients who have stopped
venom immunotherapy after just 3 to 4 years treatment.
PMID- 10669864
TI - Lack of correlation between Chlamydia pneumoniae antibody titers and adult-onset
asthma.
PMID- 10669865
TI - Body build and atopy.
PMID- 10669867
TI - Sequence analysis of two cosmids from the right arm of the Schizosaccharomyces
pombe chromosome II.
AB - We report the complete sequence of two cosmids, SPBC19C7 (34815 bp insert,
Accession No. AL023859) and SPBC15D4 (33203 bp insert, Accession No. AL031349),
localized on chromosome II of the S. pombe genome. Twelve open reading frames
(ORFs) were identified in SPBC19C7 and 16 in SPBC5D4. Two known genes were found
on each cosmid: cyr1 and uve1 on SPBC19C7, encoding adenylate cyclase and a UV
endonuclease, respectively, and gpt and pho2 on SPBC15D4, encoding an N
acetylglucosamine-1-phosphate transferase and a4-nitrophenylphosphatase,
respectively. Five ORFs similar to known proteins were found on SPBC19C7, and six
on SPBC15D4. They include putative genes for a ubiquitin protein ligase, a prolyl
tRNA synthetase, a tRNA splicing endonuclease, a voltage-gated chloride channel,
a mannosyl transferase, a kinesin-like protein, a histone transcriptional
regulator, an N-acetyltransferase, a cystathionine gamma-synthase and a TFIID
subunit. Two ORF products of SPBC15D4 do not have clear homologues: one encodes a
putative transcriptional regulator with a binuclear zinc domain and the other a
protein with six transmembrane domains. Two ORFs from SPBC15D4 are similar to
unknown ORFs, one from Saccharomyces cerevisiae and the other from Caenorhabditis
elegans. Finally, two ORFs of SPBC19C7 and six of SPBC15D4 correspond to orphan
genes. The frequent occurrence of introns and the short and degenerated intron
exon boundaries consensus sequences significantly complicated ORF predictions.
Two potential ORF-free regions spanning several kb were predicted, and a
clustering of ORFs transcribed in the same orientation was observed.
PMID- 10669868
TI - Isolation and molecular characterization of KlCOX14, a gene of Kluyveromyces
lactis encoding a protein necessary for the assembly of the cytochrome oxidase
complex.
AB - The yeast Kluyveromyces lactis was mutagenized with ethyl methane sulphonate and
mutants unable to grow on respiratory carbon sources were isolated. Functional
complementation of one of these mutants led to the isolation of KlCOX14, a gene
encoding a 64 amino acid protein which is the functional homologue of
Saccharomyces cerevisiae Cox14p, a protein necessary for the assembly of the
cytochrome oxidase holoenzyme (Glerum et al., 1995). The disruption of KlCOX14
resulted in the absence of the absorption bands relative to cytochromes a and
a(3) and in the complete loss of respiratory activity. Klcox14 mutants display
the typical phenotype of pet mutants and have a reduced growth rate. In addition,
unlike the wild-type, Klcox14 mutants are able to grow by fermentation also in
the presence of low glucose. The nucleotide sequence of KlCOX14 has been
deposited in the EMBL databank with Accession No. AJ238801.
PMID- 10669870
TI - CIp10, an efficient and convenient integrating vector for Candida albicans.
PMID- 10669869
TI - Secretory production of recombinant human chymase as an active form in Pichia
pastoris.
AB - We succeeded in expressing in a Pichia pastoris (P. pastoris) host a cDNA
encoding a mature human chymase (h-chymase) which was secreted directly into the
culture medium. Recombinant human heart chymase (rh-chymase) was purified from
the culture medium via a single one-step heparin-agarose column chromatography
tracing, using succinyl-Ala-Ala-Pro-Phe-para-nitroanilide (Suc-AAPF-pNA)
hydrolysing activity. On SDS-polyacrylamide gel electrophoresis (SDS-PAGE), the
rh-chymase showed a diffused protein band with molecular weight of 32-37 kDa.
After deglycosylation, however, rh-chymase changed to a sharp protein band with
molecular weight 28 kDa, which is equal in size to deglycosylated h-chymase. The
rh-chymase had an activity to convert one of the natural substrates, angiotensin
I, to angiotensin II. Double reciprocal plot analysis revealed that the K(m)
value ofrh-chymase against Suc-AAPF-pNA was approximately 5.1 mM, which is close
to that of purified h-chymase.
PMID- 10669871
TI - Protein disulphide isomerase genes of Kluyveromyces lactis.
AB - Two genes of Kluyveromyces lactis, KlPDI1 and KlMPD1, were studied. They code for
a protein disulphide isomerase and its structural and functional homologue,
respectively. The KlPDI1 product was 52.6% identical to Pdi1p and the KlMPD1
product 47% identical to Mpd1p of S. cerevisiae. Both genes contained the
thioredoxin-active site-related signature. Their C-termini showed a new variant
of the endoplasmic reticulum-retention signal, QDEL. A single copy of KlPDI1 was
able to complement the growth defect of a pdi1 mutation. KlMPD1 on a multicopy
vector partially suppressed the klpdi1 and pdi1 mutations. The Klpdi1 null
mutation was lethal. The klmpd1 disruptant was viable, but showed an increased
sensitivity to high temperature. Several stress response motifs were present in
the upstream sequence of KlMPD1, but not of KlPDI1, whilst the opposite is known
for the S. cerevisiae homologues. The viability of the klmpd1 mutant under
starvation for nitrogen or carbon source was not different from that of the wild
type. The syntenic relationship is discussed for the KlPDI1 gene regions with
respect to the duplicated segments PDI1/EUG1 in S. cerevisiae.
PMID- 10669872
TI - The ubiquitin-encoding genes of Kluyveromyces lactis.
AB - The ubiquitin encoding genes of Kluyveromyces lactis were cloned. Three genes,
KlUBI1, KlUBI3 and KlUBI4, were found in this yeast, while in Saccharomyces
cerevisiae there are four genes, UBI1, -2, -3 and -4. The UBI1/UBI2 duplication
is thus absent from the K. lactis genome. General structural features of
ubiquitin genes were very similar in these two species (presence of an intron in
KlUBI1, fusion to ribosomal protein genes in KlUBI1 and KlUBI3, spacer-less
polyubiquitin repeats in KlUBI4). Disruption or deletion of K. lactis ubiquitin
genes showed that: (a) disruption of KlUBI1 was lethal (in S. cerevisiae,
ubi1/ubi2 double deletion is lethal); (b) KlUBI3 is also an essential gene for
cell growth; (c) deletion of KlUBI4 led to an increased sensitivity to high
temperature, similar to the ubi4 mutation in S. cerevisiae, but, in contrast to
the latter, the klubi4 mutant was not sensitive to carbon or nitrogen source
starvation. The syntenic relationship of ubiquitin loci between K. lactis and S.
cerevisiae genomes is also described.
PMID- 10669873
TI - Identification of functionally important regions of the Saccharomyces cerevisiae
mitochondrial translational activator Cbs1p.
AB - Translation of cytochrome b mRNA in yeast mitochondria requires activation by the
nuclear-encoded Cbs1p. According to the current model, Cbs1p tethers cytochrome b
mRNA to the inner mitochondrial membrane via interaction with the 5'-untranslated
leader. Cbs1p is predicted to be a hydrophilic protein with two hydrophobic
segments near the carboxyl-terminal end, which are both too short to span the
membrane. Nevertheless Cbs1p is tightly associated with the mitochondrial
membrane, as shown by its behaviour in extraction experiments with
taurodeoxycholate. In an attempt to define functionally important regions of
Cbs1p, we created a number of mutant alleles by random and directed mutagenesis.
We report that a Cbs1p mutant protein lacking the mitochondrial presequence is
still able to complement a Deltacbs1 strain, suggesting that the presequence does
not contain essential mitochondrial targeting information. Mutations in a cluster
of positively charged amino acids at the extremeC-terminus have no effect on
Cbs1p function, but removal of this segment severely impairs Cbs1p function.
Truncation of 12 or more amino acids from the C-terminus results in a completely
defective protein. We further show that both short hydrophobic regions are
essential for Cbs1p function, although membrane association is observed even in
the absence of these regions.
PMID- 10669874
TI - Disruption and phenotypic analysis of six open reading frames from the left arm
of Saccharomyces cerevisiae chromosome VII.
AB - Six open reading frames (ORFs) from Saccharomyces cerevisiae chromosome VII were
deleted using the kanMX4 module and the long-flanking homology-PCR replacement
strategy in at least two different backgrounds. Among these ORFs, two of them
(YGL100w and YGL094c) are now known genes which encode well-characterized
proteins (Seh1p, a nuclear pore protein, and Pan2p, a component of Pab1p
stimulated poly(A) ribonuclease, respectively). The other four ORFs (YGL101w,
YGL099w, YGL098w and YGL096w) code for proteins of unknown function, although the
protein encoded by YGL101w has a strong similarity to the hypothetical protein
Ybr242p. Gene disruptions were performed in diploid cells using the KanMX4
cassette, and the geneticin (G418)-resistant transformants were checked by PCR.
Tetrad analysis of heterozygous deletant strains revealed that YGL098w is an
essential gene for vegetative growth in three backgrounds, whereas the other five
genes are non-essential, although we have found some phenotypes in one of them.
YGL099wDelta strain did not grow at all at 15 degrees C and showed a highly
impaired sporulation and a significantly lower mating efficiency. The other three
deletants did not reveal any significant differences with respect to their
parental strains in our basic phenotypic tests.
PMID- 10669875
TI - Disruption of six novel genes from chromosome VII of Saccharomyces cerevisiae
reveals one essential gene and one gene which affects the growth rate.
AB - Six ORFs of unknown function located on chromosome VII of Saccharomyces
cerevisiae were disrupted in two different genetic backgrounds, and the phenotype
of the generated mutants was analysed. Disruptions of ORFs YGR256w, YGR272c,
YGR273c, YGR275w and YGR276c were carried out using the disruption marker kanMX4
flanked by short homology regions, whereas ORF YGR255c was inactivated with a
long flanking homology (LFH) disruption cassette (Wach et al., 1994). Tetrad
analysis of the heterozygous disruptants revealed that ORF YGR255c, previously
identified as COQ6 and encoding a protein involved in the biosynthesis of
coenzime Q (Tzagoloff and Dieckmann, 1990), is an essential gene. The same
analysis also revealed that sporulation of the ygr272cDelta heterozygous diploid
produced two small colonies per ascus that were also G418-resistant, indicating
that the inactivation of ORF YGR272c could result in a slower growth rate. This
result was confirmed by growth tests of the haploid disruptants and by
complementation of the phenotype after transformation with a plasmid carrying the
cognate gene. No phenotypes could be associated to the inactivation of ORFs
YGR256w, YGR273c, YGR275w and YGR276c. Two of these genes have recently been
further characterized: ORF YGR255w, renamed RTT102, encodes a regulator of the
Ty1-element transposition, whereas ORF YGR276c was found to encode the 70 kDa
RNase H activity and was renamed RNH70 (Frank et al., 1999).
PMID- 10669876
TI - Electrospray multistep ion trap mass spectrometry for the structural
characterisation of poly
AB - Electrospray 'soft' ionisation (ESI) and multistep mass spectrometry (MS(n))
techniques enable characterisation of a bioactive polymer, poly[(R,S)-3
hydroxybutanoic acid] (a-PHB), containing covalently bonded benzylpenicillin. The
chemical structures of individual mass-selected bioactive macromolecules have
been determined, and their fragmentation mechanisms have been compared with those
of pure penicillin G. Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669877
TI - Studies in organic mass spectrometry. Part 25. Benzyl ion formation in chemical
ionisation (methane or isobutane) of some ortho-alkylhetero-substituted
diphenylcarbinols
AB - The behaviour of some ortho-alkylhetero-substituted diphenylcarbinols, including
deuterium labelled derivatives, under chemical ionisation (methane or isobutane)
conditions has been investigated. It has been determined that ortho-alkylhetero
diphenylmethyl cations formed by water elimination from the protonated molecule
undergo consecutive rearrangements which afford benzyl (or tropylium) ions
previously observed for ortho-substituted diphenylcarbenium ions generated by
electron ionisation. This reaction also occurs under low-energy collision
conditions. Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669878
TI - Validation of higher-throughput high-performance liquid
chromatography/atmospheric pressure chemical ionization tandem mass spectrometry
assays to conduct cytochrome P450s CYP2D6 and CYP3A4 enzyme inhibition studies in
human liver microsomes.
AB - In the early stage of drug discovery, thousands of new chemical entities (NCEs)
may be screened before a single drug candidate can be identified for development.
In order to accelerate the drug discovery process, we have developed higher
throughput enzyme assays to evaluate the inhibition of cytochrome P450 isoforms
2D6 (CYP2D6) and 3A4 (CYP3A4) in human liver microsomes. The assays are based on
high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS)
techniques. The analysis time for each sample was reduced from approximately 20
minutes for the conventional HPLC assay to 30 seconds for the LC/MS/MS assay. For
both LC/MS/MS assays, the linearity (r(2) > 0.99), precision (%CV < 15%) and
accuracy (% bias <15%) for both inter- and intraday validations were
satisfactory. Since the implementation of the LC/MS/MS assays, our sample
throughput has increased by over 40-fold.
PMID- 10669879
TI - Theoretical and numerical analysis of the behavior of ions injected into a
quadrupole ion trap mass spectrometer
AB - A numerical simulation method has been developed for the analysis of trapping
ions injected into an ion trap mass spectrometer. This method was applied to
clarify the effects of the following parameters on trapping efficiencies: (1)
initial phase of the radio frequency (RF) drive voltage, (2) ion injection
energy, and (3) RF peak voltage while injecting ions. The following conclusions
were obtained by theoretical and simulation approaches. 1. The second and third
dominant oscillations contribute significantly to the trapping mechanism of the
injected ions, even for low q values. 2. A formula relating the operating
parameters, which gives the maximum trapping efficiency, is derived. 3. Based on
the above-mentioned formula, an advanced injection method is proposed, in which
the RF peak voltage is decreased while injecting ions. The ability of this method
to solve the problem of unequal sensitivity among different ion species is
indicated by numerical simulation. Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669880
TI - Determination of disulfide bonds in highly bridged alpha-dendrotoxin by matrix
assisted laser desorption/ionization mass spectrometry
AB - A methodology which combines tryptic digestions, 1,4-dithiothreitol reduction,
and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF-MS)
allows verification of the location of the disulfide bridges in alpha-dendrotoxin
(C7-C57, C16-C40 and C32-C53). Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669881
TI - High throughput on-line solid phase extraction/tandem mass spectrometric
determination of paclitaxel in human serum.
AB - The feasibility of high throughput on-line solid phase extraction/tandem mass
spectrometry (SPE/MS/MS) is tested for target analysis of paclitaxel in human
serum. The use of a dual Prospekt system, with parallel SPE and elution directly
to the mass spectrometer, resulted in a cycle time of 80 seconds for the entire,
fully automated assay. The assay proved to be linear from 1 to 1000 ng/mL.
Cartridges packed with small sorbent particles functioned both as SPE cartridges
and as short analytical columns.
PMID- 10669882
TI - Analysis of solid-supported oligonucleotides by matrix-assisted laser
desorption/ionization time-of-flight mass spectrometry
AB - This study presents matrix-assisted laser desorption/ionization time-of-flight
mass spectrometry (MALDI-TOFMS) as a powerful tool to analyze and characterize
oligonucleotides covalently linked to a solid support during their synthesis. The
analysis of the fragment ions generated either in negative or positive mode
allows direct and easy access to the nucleotide sequence and identification of
the internucleosidic linkage. The mechanisms of the fragmentation of the solid
supported oligonucleotides induced by MALDI-TOFMS are discussed. Copyright 2000
John Wiley & Sons, Ltd.
PMID- 10669883
TI - Electrospray ionization mass spectrometry of synthetic oligonucleotides using 2
propanol and spermidine
AB - Oligonucleotides have become widely used tools in molecular biology and molecular
diagnostics. Their parallel synthesis in large numbers and the increasing
interest in microarray technology has raised the requirement for fast and
informative analytical tools for their quality control. A direct injection
electrospray ionization mass spectrometry (ESI-MS) technique based on the use of
aqueous 2-propanol as running eluent, and spermidine (or triethylamine) as DNA
modifiers, has been applied to analyze a large set of samples (about 200
synthetic oligonucleotides) ranging from 5 to 15 kDa (17-51mers) with good
results in terms of sensitivity, suppression of sodium adduct formation, and
speed of analysis. Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669884
TI - Ion trap MS(n) genealogical mapping-approaches for structure elucidation of novel
products of consecutive fragmentations of morphinans
AB - The analysis of data within multi-generational, genealogical, electrospray
ionization/MS(n) fragmentation maps is discussed in reference to the structure
elucidation of morphinans, an important class of pharmacological compounds.
Various general approaches to separate and understand observed processes are
discussed. These include: (1) Simple synthetic schemes incorporating deuterium
and (13)C into morphinans to study later-generation, O-methyl group migration;
(2) labeling to understand 'intense' signals for even-electron to odd-electron
ion 'switching' events; (3) gas phase 'synthesis' of proposed MS(3) ions via an
independent route, using chemical ionization (CI) MS/MS of naphthalenes and
analysis via a bench-top El/Cl ion trap; (4) a useful synthetic paradigm for
generating proposed carbonium ion structures at MS(4) via electrospray ionization
(ESI) of easily synthesized amines; (5) the analysis of an oxidation product and
correlation of MS(n) data of a switched, odd-electron species with electron
ionization and low-pressure, low-energy charge exchange data; and (6) a new way
of summarizing MS(n) data. Copyright -Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669886
TI - Origin of mass shifts in the quadrupole ion trap: dissociation of fragile ions
observed with a hybrid ion trap/mass filter instrument
AB - A novel hybrid tandem mass analyzer, coupling a quadrupole ion trap with a
quadrupole mass filter, has been constructed to permit mass analysis of ions
ejected from the ion trap. The initial application of this instrument is the
investigation of the origin of mass shifts in the ion trap due to ion fragility.
We hypothesize that fragile ions undergo mass shifts, characterized by peak
fronting, due to early ejection from the quadrupole ion trap. As these ions come
into resonance with the ejection frequency, they gain kinetic energy, collide
with buffer gas molecules and thus can dissociate to produce fragment ions. These
fragment ions will not be stable within the ion trap as they are situated past
the stability boundary at q(z) = 0. 908. Consequently the fragment ions are
ejected prematurely. This results in an apparent mass shift due to peak fronting.
The experiments reported here clearly document the production of fragment ions as
the origin of mass shifts during the resonant ejection of fragile ions. Copyright
2000 John Wiley & Sons, Ltd.
PMID- 10669885
TI - Elucidation of peptide metabolism by on-line immunoaffinity liquid chromatography
mass spectrometry.
AB - An immunoaffinity chromatography extraction capillary liquid chromatography
separation has been coupled to electrospray ionization mass spectrometry for on
line characterization of drug metabolites of a therapeutic peptide in plasma. It
is demonstrated that the selectivity, sensitivity and molecular weight data
provided by immunoaffinity chromatography coupled to liquid chromatography/mass
spectrometry provides a means of rapidly achieving qualitative determinations of
small amounts of material in complicated biological matrices such as plasma. The
ability to detect the peptide in rat plasma at a level of 10 ng/mL is
demonstrated using this method. In addition, experiments to study the epitope of
the peptide by enzymatic digestion and mass spectrometry are also discussed. The
method is proposed as an alternative approach to studying the metabolism of
therapeutic peptides.
PMID- 10669887
TI - Frozen shell approximation violation in negative ion formation from halogenated
benzenes via dissociative attachment
AB - A series of benzene derivatives (R(1)C(6)H(4)R(2)) has been studied by means of
electron capture negative ion mass spectrometry (ECNI-MS), and PM3 quantum
chemical calculations. The dissociation channel M(-.) --> Hal(-) + (M - Hal). is
analysed from the point of view of symmetry conservation. Generally, a symmetry
ban on dissociation may be avoided in at least two ways: (i) out-of-plane
vibrations of the halogen atom in the molecular negative ion (MNI), mixing pi-
and sigma-states of the anion; (ii) symmetrical in-plane vibration of the C-Hal
bond, changing the order of the empty levels in the MNI with subsequent
radiationless conversion into a sigma-state. Our analysis shows that neither of
them provides a satisfactory explanation of the ECNI mass spectra for
chlorobenzene, if one retains the usual assumption that an additional electron
goes into the LUMO of the neutral molecule. Thus, it may be concluded that in
this case electron capture causes a significant perturbation of the energy
ordering of vacant orbitals, thus making the frozen shell approximation
inapplicable. Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669888
TI - Determination of tetracyclines in bovine kidney by liquid chromatography/tandem
mass spectrometry with on-line extraction and clean-up.
AB - A novel, sensitive, high performance liquid chromatography/tandem mass
spectrometric (i.e. mass spectrometry/mass spectrometry) method with on-line
extraction and clean-up for the screening and confirmation of residues of
tetracyclines in kidney has been developed. After liquid extraction of
homogenised kidney with McIlvain buffer, an aliquot of the extract is directly
injected on the LC/MS/MS system with further extraction and clean-up of the
sample on-line. Detection of the analytes was achieved by positive electrospray
ionization followed by multiple reaction monitoring. For each tetracycline the
collisional decomposition of the protonated molecule to a unique, abundant
fragment ion was monitored. The method has been validated for tetracycline,
oxytetracycline, chlortetracycline and doxycycline. Calibration curves resulting
from spiked blank kidney samples at the 100-1200 microgram/kg level showed good
linear correlation. At the level of 600 microgram/kg both within- and between-day
precision, as measured by relative standard deviation (RSD), were less than 7%.
The limits of detection (LODs) for tetracycline, oxytetracycline,
chlortetracycline and doxycyline were 18, 23, 24 and 21 microgram/kg,
respectively. The limits of quantification (LOQs) for tetracycline,
oxytetracycline, chlortetracycline and doxycyline were 36, 46, 47 and 42
microgram/kg, respectively. The recoveries ranged from 71 to 91%. The procedure
provides a rapid, reliable and sensitive method for the determination of residues
of tetracyclines in bovine kidney. The advantage of this method over existing
methods is its decreased sample preparation and analysis time, which makes the
method more suitable for routine analysis.
PMID- 10669889
TI - On-line size-exclusion chromatography/electrospray ionisation mass spectrometry
of aquatic humic and fulvic acids
AB - Isolated aquatic humic and fulvic acids were analysed with on-line size exclusion
chromatography/electrospray ionisation mass spectrometry (SEC/ESI-MS). An eluent
composition which enabled electrospray ionisation was identified. The SEC
separation improved interpretability of mass spectra and may open up new
possibilities for molecular weight determination of humic substances. A linear
dose-response relationship over a factor of 20 was obtained and the limit of
detection was 50ng/uL for humic and fulvic acids. Spectral changes due to
different ionisation conditions (pH and cone voltage) were investigated. A
natural water sample from a Swedish lake was analysed. Copyright 2000 John Wiley
& Sons, Ltd.
PMID- 10669890
TI - Sample vial influences on the accuracy and precision of carbon and oxygen isotope
ratio analysis in continuous flow mass spectrometric applications
AB - Due to the small amounts of sample gas involved in continuous flow mass
spectrometric analysis, care should be taken to evaluate the influence of sample
containers on the carbon and oxygen isotope ratios of samples. Data indicate that
Na-glass and borosilicate glass vials, equipped with butyl rubber septa, can
cause significant changes in the isotopic composition of CO(2) gas, even where
sample gases are stored within the vial for less than one day. The magnitude of
these changes varies from vial to vial. Given the leverage that contamination can
potentially exert on small gas samples, each researcher should carefully evaluate
the effect of sample vials in order to eliminate unknown and unwanted changes in
the composition of samples. Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669891
TI - Characterization of organometallic coordinative cluster compounds of silver by
matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
AB - Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
(MALDI-TOFMS) was successfully applied to characterize the organosilver
coordinative cluster compounds, silver phenylacetylide and three silver
thiolates, namely, silver tertiary butylthiolate, silver 2,6
dimethylbenzenethiolate, and silver 2, 6-dichlorobenzenethiolate. Samples and
dithranol matrix were finely dispersed in 1:1 tetrahydrofuran (THF)/chloroform
(CHCl(3)) mixed solvent. In most cases the monomer units remained intact during
ionization, and the oligomeric molecular ions were produced through silver
cationization, with a general molecular ion formula [nM + Ag](+). This was
further verified by the relative abundances of the isotopic peaks within the
molecular ion clusters, which were in close agreement with those theoretically
calculated for nM cationized with one silver ion. In the case of silver 2, 6
dichlorobenzenethiolate, in addition to the dominant [nM + Ag](+) peaks, weak
peaks corresponding to the successive losses of hydrogen chloride molecules were
observed. Copyright 2000 John Wiley & Sons, Ltd.
PMID- 10669892
TI - Density-dependent dynamics and superinfection in an epidemic model.
AB - A mathematical model of the interaction between two pathogen strains and a single
host population is studied. Variable population size, density-dependent
mortality, disease-related deaths (virulence), and superinfection are
incorporated into the model. Results indicate that coexistence of the two strains
is possible depending on the magnitude of superinfection. Global asymptotic
stability of the steady-state that gives coexistence for both strains under
suitable and biologically feasible constraints is proved.
PMID- 10669893
TI - A Kermack-McKendrick model applied to an infectious disease in a natural
population.
AB - The dynamics of a fatal infectious disease in a population regulated by density
dependent constraints are represented as a system of nonlinear integral
equations. Survival probabilities and disease transmission coefficients may vary
with the time elapsed since infection, and horizontal and vertical modes of
transmission are allowed for. Criteria for the existence and stability of steady
states are derived, and an example based on the dynamics of tuberculosis is
presented. Finally, the relative merits of this approach, and the familiar
compartmental models based on differential equations are discussed.
PMID- 10669894
TI - Multihost, multiparasite systems: an application of bifurcation theory.
AB - The local analysis of multihost multiparasite models has been hampered by
algebraic intractability. There have been two responses to this difficulty:
extensive numerical investigation, and simplification to a level where analytical
techniques work. In this paper we describe another approach, based on bifurcation
theory, in which the qualitative properties of the model equilibrium structure
are realized on an array of maps drawn in parameter space. This approach is
described in the context of two models: the basic two-host shared microparasite S
I model and the single-host two-microparasite S-I (susceptible-infective) model.
The procedure involved does not require model simplification through a reduction
in dimensionality. It can handle intraspecific as well as parasite-mediated
competition and, in the second model, single-host parasite coexistence. The map
arrays provide a concise catalogue of the possible modes of behaviour of a system
and an explanation for changes in that behaviour. In particular, the reasons why
the conjectures made about the behaviour of the first of these models do not hold
throughout parameter space are immediately clear from the map structure, as are
the conditions for collusive and competitive behaviour between the two types of
parasite in the second model.
PMID- 10669895
TI - Modelling corneal epithelial wound closure in the presence of physiological
electric fields via a moving boundary formalism.
AB - A new framework for the modelling of corneal epithelial wound healing is
presented, which can include the presence of a physiological electric field. The
difficulty inherent in the inclusion of this biological phenomenon motivates our
use of a moving boundary formalism. A key conclusion is that the model predicts a
linear relation between the wound healing speed and the physiological electric
field strengths over a physiologically large range of electric field strength.
Another key point is that this linear relationship between electric field
strength and wound healing speed is robust to variations in critical parameters
that are difficult to estimate. The linearity is also robust to different
realizations of the modelling framework presented.
PMID- 10669896
TI - On a branching model of division-within-division.
AB - We consider a deterministic version of a stochastic model for division-within
division processes described by Kimmel (1997, In: Proceedings of the IMA Workshop
'Classical and Modern Branching Processes' (K. Arthreya and P. Jagers, eds.)????
:????). It is shown that the behaviour of the deterministic model can be analyzed
by using an associated Markov chain, using the methods of Barbour et al.
PMID- 10669897
TI - Pharmacokinetics of benflumetol given as a fixed combination artemether
benflumetol (CGP 56697) in Thai patients with uncomplicated falciparum malaria.
AB - The pharmacokinetics of benflumetol as a fixed combination, artemether
benflumetol (CGP 56697), following three regimens [regimen A: four tablets at 0,
8, 24 and 48 h (320 mg artemether, 1,920 mg benflumetol); regimen B: two tablets
at 0, 8, 24 and 48 h (160 mg artemether, 960 mg benflumetol); regimen C: four
tablets at 0, 8 and 24 h (240 mg artemether, 1,440 mg benflumetol)] were
investigated in 39 patients with acute uncomplicated falciparum malaria. All
patients showed a rapid initial response with a median parasite clearance time of
40, 41 and 39.5 h and a fever clearance time of 27.8, 32 and 24.5 h for regimens
A, B and C, respectively. In nine patients (two, four and three patients in
regimens A, B and C, respectively), however, parasitemia reappeared in the
peripheral blood smear between days 9 and 23. The pharmacokinetics of benflumetol
were highly variable, with coefficients of variation in pharmacokinetic
parameters ranging from 14.9% to 144%. Absorption and elimination of benflumetol
were relatively slow. Median Cmax per dose (first dose) was significantly higher
in regimen B (6.29 ng/ml/mg dose) than in regimen A (2.6 ng/ml/mg dose) and
regimen C (3.06 ng/ml/mg dose). Mean T1/2z in regimen C (2.65 h) was
significantly shorter than in regimen A (4.5 h) and regimen B (3.89 h). In
patients on regimens A and B who showed a sensitive response, plasma
concentrations of benflumetol were significantly higher than in those with
treatment failure.
PMID- 10669898
TI - Analgesic effects of diclofenac suppository and injection after preoperative
administration.
AB - Diclofenac sodium (100 mg) has been introduced in the Caribbean as a suppository
formulation. In a randomized single-blind (observer-blind) clinical trial, the
postoperative analgesic efficacy of diclofenac administered either as a
conventional intramuscular injection (75 mg) or as the available suppository
formulation (100 mg) was studied in 44 adult male patients undergoing
herniorrhaphy in same day surgery. Diclofenac was administered preoperatively at
induction of anesthesia to patients (grades ASA I and II) after they had given
informed consent. Evaluation of analgesia on the visual analog scale (VAS) did
not differ significantly between the two treated groups at three assessment
times: on admission to the recovery room, the postoperative ward and at
discharge. The times for requests for additional analgesia and the number of
patients requesting further analgesia did not differ. Patients who received the
suppository were discharged earlier than those who received the injection (40 min
vs. 65 min p = 0.02). This preliminary study of the two marketed formulations of
diclofenac demonstrated that both preparations provided equivalent analgesia but
patients who received the suppository preparation were discharged earlier.
PMID- 10669899
TI - Effect of a mineral water on gastric emptying of patients with idiopathic
dyspepsia.
AB - The antidyspeptic property of mineral waters has for many years been based on
empirical data. In the present paper we evaluated the effects of one type of
mineral water, Tettuccio water from Montecatini, on gastric emptying in patients
with idiopathic dyspepsia. Fourteen subjects, eight patients with idiopathic
dyspepsia and delayed gastric emptying at scintigraphy and six healthy subjects
with normal gastric emptying were studied. The gastric emptying of mineral water
was studied with a scintigraphic method and compared with that of tap water. In
patients with idiopathic dyspepsia, gastric emptying of both waters was slower
than in controls but the gastric emptying of mineral water was significantly
faster than that of tap water, both in dyspeptic patients and in healthy
subjects. In conclusion, this mineral water stimulates gastric emptying. Further
studies are needed on the possible role of this water in the management of
chronic idiopathic dyspepsia.
PMID- 10669900
TI - Efficacy and safety of sumatriptan 50 mg in patients not responding to standard
care, in the treatment of mild to moderate migraine. The Sumatriptan 50 mg
Italian Study Group.
AB - The tolerability and efficacy of oral sumatriptan 50 mg for the treatment of mild
to moderate migraine attacks were assessed in a double-blind, multicenter placebo
controlled study on a group of patients who had not responded sufficiently to
analgesic preparations. Three-hundred-and-twenty-eight migraine sufferers treated
a first migraine attack with a nontriptan standard care medication: a mixture
containing phenazone, butalbital and caffeine (optalidon) or indomethacin plus
prochlorperazine plus caffeine (difmetre) or paracetamol 100 mg (tachipirine),
depending on their habits. Of these patients, 32.6% reported headache relief with
this treatment and were not included in phase II of the study. The 219 patients
not reporting relief during the first phase of the study entered the second phase
and were randomized to sumatriptan 50 mg or to placebo; 167 of these patients
treated a second attack according to the protocol and were evaluated for
efficacy. Of the patients with migraine taking sumatriptan, 58% reported headache
relief compared with 35% of placebo-treated patients (p = 0.008). The reduction
of nausea and vomiting was significantly better in the sumatriptan group. No
differences were detected for the recurrence rate, while rescue medication was
used more by the placebo group. The safety profile of sumatriptan 50 mg was
confirmed. This study demonstrates the usefulness of this dose of oral
sumatriptan against the pain and the accompanying symptoms of mild and moderate
migraine.
PMID- 10669901
TI - Proliferation of spleen cells in culture stimulated by 7-thia-8-oxoguanosine:
evidence that both B- and T-cells are the targets of its action.
AB - 7-thia-8-oxoguanosine (immunosine) is a nucleoside analog showing efficient
antiviral activity in rodent models as a consequence of enhancement of the immune
response. However, little is known about the mechanisms of its action. In this
work the effect of immunosine on proliferation of mouse and rat splenocytes in
culture was studied. It was found that the compound stimulated proliferation of
lymphocytes in a dose-dependent manner without any additional stimuli. The effect
is predominantly mediated by interleukin-2 (IL-2) as judged by increased IL-2
production, upregulation of IL-2 receptor alpha (IL-2R alpha) expression and by
significant inhibition (60-75%) of cell proliferation by anti-IL-2R alpha
monoclonal antibodies (mAbs). Immunosine also stimulated proliferation both of T-
and B-cells purified by immunomagnetic sorting. The response of B-cells was much
higher than that of T-cells. The stimulatory effect of immunosine on both
lymphocyte subpopulations was further increased by the addition of enriched
splenic antigen-presenting cells or purified dendritic cells. Proliferation of
purified T-cells to immunosine was also significantly potentiated by an anti
alpha beta T-cell receptor mAb (R 73). All these data suggest that T-, B- and
accessory cells in splenic cultures are the targets of immunosine action.
PMID- 10669902
TI - Effects of newly synthesized analogs of MIF-1 containing unnatural amino acids on
electrically evoked smooth muscle contractions.
AB - New MIF-1 (Pro-Leu-Gly-NH2) analogs containing unnatural amino acids such as L
canavanine (Cav) and L-cysteic acid S-(2-aminoethyl)amide (sLys) have been
synthesized and in vitro experiments were performed to study their action on
neurotransmission in target tissues with adrenergic and cholinergic
neurotransmission. The experiments were carried out on electrically stimulated
proximal guinea pig ileum (GPI) and the prostatic part of rat and rabbit vasa
deferentia (VDR, VDRabb). The present results show that the newly synthesized
Cav2-MIF and sLys2-MIF might affect electrically evoked smooth muscle
contractions.
PMID- 10669903
TI - Involvement of spinal delta 1-opioid receptors in forced walking stress-induced
antinociception in the tail-flick test in mice.
AB - The purpose of this study was to elucidate the involvement of spinal delta-opioid
receptor subtypes in forced walking stress-induced antinociception mice. We first
confirmed that forced walking stress produced walking duration-dependent
antinociception in mice as determined by the tail-flick test. Intrathecal
treatment with 7-benzylidenenaltrexone, a selective delta 1-opioid receptor
antagonist, significantly attenuated forced walking stress-induced
antinociception. In contrast, intrathecal treatment with naltriben, a selective
delta 2-opioid receptor antagonist, had no significant effect on forced walking
stress-induced antinociception. Intracerebroventricular treatment with either 7
benzylidenenaltrexone or naltriben had no effect on the forced walking stress
induced antinociception. These results suggest that forced walking stress-induced
antinociception is mediated by spinal delta 1-opioid receptors in mice.
PMID- 10669904
TI - Effects of repeated selective serotonin reuptake inhibitor paroxetine treatments
on mouse forced swimming.
AB - Studies were performed in the mouse forced swimming model, a well known
experimental depression model, in order to detect the mechanism of the
antidepressive effects induced by repeated serotonin reuptake inhibitor (SSRI)
dosing. Five-day repeat dosing of a typical SSRI, paroxetine, increased climbing,
a distinctive antidepressive behavior, 1 h after but not 1 h before treatment.
The coinjection of paroxetine and serum in mice treated with four repeated doses
of paroxetine distinctively increased the behavior, but the coinjection of
paroxetine and serum in mice without paroxetine did not. These results indicate
that repeated dosing of paroxetine produces a serum substance related to the
antidepressive effects induced by serotonin neuron activities. Furthermore, the
behavior induced by 5-day repeated dosing of paroxetine was decreased by 100 and
10 micrograms/kg of ketanserin (5-HT2 antagonist) and 100 micrograms/kg of LY
278584 (5-HT3 antagonist). The present findings strongly suggest that repeated
dosing of paroxetine produces a serum substance stimulating the antidepressive
neuronal pathway sensitively mediated by 5-HT2 and 5-HT3 receptor activity.
PMID- 10669905
TI - Quinpirole, 8-OH-DPAT and ketanserin modulate catalepsy induced by high doses of
atypical antipsychotics.
AB - The effect of the selective dopamine D2 receptor agonist quinpirole, the
selective 5-HT1A receptor agonist 8-OH-DPAT and the selective 5-HT2A receptor
antagonist ketanserin on catalepsy induced by atypical antipsychotics clozapine,
risperidone, olanzapine and sertindole at higher doses was studied in rats.
Haloperidol (0.5, 1 and 2 mg/kg), clozapine (50 and 75 mg/kg) and olanzapine (15
and 30 mg/kg) produced catalepsy dose-dependently while sertindole at doses up to
40 mg/kg failed to produce catalepsy in rats. However, sertindole (15, 30 and 45
mg/kg) produced a cataleptic effect in mice in a dose-dependent manner. At a high
dose (5 mg/kg), risperidone produced catalepsy in rats. Quinpirole (0.05 and 0.1
mg/kg) reversed the cataleptic effect of haloperidol (2 mg/kg), risperidone (5
mg/kg), olanzapine (30 mg/kg) and sertindole (45 mg/kg). Quinpirole (0.05 and 0.1
mg/kg) reversed clozapine (75 mg/kg)-induced catalepsy. 8-OH-DPAT (0.15 and 0.3
mg/kg) dose-dependently reversed catalepsy induced by haloperidol (2 mg/kg) and
risperidone (5 mg/kg) without affecting the cataleptic effect of olanzapine.
However, the higher dose (0.45 mg/kg) of 8-OH-DPAT reversed it significantly. 8
OH-DPAT (0.3 mg/kg) reversed clozapine (75 mg/kg)-induced catalepsy. 8-OH-DPAT
(0.15, 0.3 and 0.45 mg/kg) failed to reverse sertindole-induced catalepsy.
Ketanserin (0.75 and 1.5 mg/kg) completely reversed catalepsy induced by
haloperidol (2 mg/kg) and risperidone (5 mg/kg). Ketanserin (0.75 and 1.5 mg/kg)
dose-dependently reversed olanzapine (30 mg/kg) and sertindole (45 mg/kg)-induced
catalepsy without any effect on clozapine (75 mg/kg)-induced catalepsy. A higher
dose (3 mg/kg) of ketanserin reversed clozapine-induced catalepsy. The present
study suggests that atypical antipsychotics show fewer extrapyramidal symptoms
(EPS) due to greater modulation of the serotonergic system. Therefore, an
antipsychotic with dopamine D2/5-HT2A antagonistic action and 5-HT1A agonistic
action may prove to be superior to the existing antipsychotics.
PMID- 10669906
TI - Role of nitric oxide in electroshock and pentylenetetrazole seizure threshold in
rats.
AB - There are contradictory reports on whether nitric oxide (NO) is a proconvulsant
or anticonvulsant. Hence a study was designed to investigate the effect of NO
donor l-Arginine and NO synthesis inhibitor N omega-nitro-L-arginine (NOARG) on
electroshock- and pentylenetetrazole (PTZ)-induced seizure threshold in rats. L
arginine was tested in three doses (75, 150 and 300 mg/kg), and NOARG was
administered in doses of 4, 8 and 16 mg/kg. L-Arginine increased the intensity of
current required to produce a threshold seizure, whereas NOARG had the opposite
effect. In PTZ-induced seizures, L-arginine significantly decreased the dose of
PTZ required to produce a threshold seizure, while NOARG increased it. Hence, it
was concluded that NO synthase inhibition had the opposite effect in electroshock
and PTZ-induced seizures, meriting further studies on the mechanism of effect.
PMID- 10669907
TI - Effects of histamine and related compounds on regional cerebral blood flow in
rats.
AB - The effects of histamine and related compounds on regional cerebral blood flow
(rCBF) in the hippocampus of conscious rats were studied. Intracerebroventricular
injection of histamine caused a dose-dependent increase in rCBF in the
hippocampus, and similar findings were observed with not only the H1 agonist, 2
thiazolylethylamine, but also the H2 agonist, dimaprit. Intraperitoneal injection
of L-histidine also resulted in an increase in rCBF in the hippocampus, in
parallel with elevation of histamine content in the brain. The increase in rCBF
in the hippocampus induced by L-histidine was antagonized by both H1 and H2
antagonists (diphenhydramine, pyrilamine and zolantidine). In addition, when both
antagonists were injected simultaneously, an additive effect was observed in
antagonism of the L-histidine-induced increase in rCBF. L-Histidine caused no
marked changes in blood pressure even at a dose of 1,500 mg/kg, which showed an
increase in rCBF in the hippocampus. These results indicate that histamine
elicited an increase in rCBF via both H1 and H2 receptors.
PMID- 10669908
TI - Enhanced cardiovascular reactivity to desmopressin in water-restricted rats:
facilitatory role of immunosuppression.
AB - There is considerable evidence suggesting that vasopressin may play an important
role in regulating cardiovascular homeostasis. In the present study the effects
of immunosuppressant drugs, ciclosporin and tacrolimus on arterial blood pressure
(BP) and heart rate (HR) responses to desmopressin (DDAVP) were compared in
anesthetized normally hydrated and 24-h water-restricted rats. When injected
intravenously, single bolus doses of DDAVP (0.5-8.0 micrograms/kg) elicited dose
dependent decreases in BP and also attenuated the HR. The enhancement of the
vasodepressor response to DDAVP (4 micrograms/kg) was produced 15 min after the
intravenous injection of either ciclosporin (3 mg/kg) or tacrolimus (25
micrograms/kg) accompanied by reduction in HR in water-restricted animals, but
the response in euhydrated animals remained less modified after the bolus
injections of immunosuppressants and DDAVP. To elucidate the possible
contribution of the renal vascular system in water-restricted rats, ciclosporin
was administered intravenously, followed 15 min later by 4 micrograms/kg
injections of arginine vasopressin (AVP) or DDAVP into the renal artery, but
there was no significant change in both the cardiovascular parameters as compared
with the responses obtained with agonists alone. The present results indicate
that the augmentation of the cardiovascular response to DDAVP by ciclosporin and
tacrolimus in water-restricted anesthetized rats appears to be mediated by the
release of endogenous vasodilatory mediators.
PMID- 10669909
TI - Bioequivalence study of rifampicin in fixed-dose combination of rifampicin and
isoniazid vs. separate formulations.
AB - The benefits of fixed-dose combinations of antituberculosis agents are well
recognized by the World Health Organization (WHO) and International Union Against
Tuberculosis and Lung Disease (IUATLD) and preferred over separate formulations.
Therefore, a comparative bioequivalence study of rifampicin and isoniazid
together in a fixed-dose combination and separately (at the same dose levels) was
performed on a group of 12 healthy subjects. The study was designed as a single
blind, crossover experiment. Nine blood samples were collected from each subject
over a period of 24 h. The plasma concentrations of rifampicin were assessed by a
method developed in this laboratory. Various pharmacokinetic parameters of
rifampicin such as AUC, Cmax, Tmax and t1/2 were also calculated. The study
demonstrates that a fixed-dose combination (test formulation) and separate
formulations (standard formulations) are bioequivalent for rifampicin.
PMID- 10669910
TI - Lack of pharmacokinetic interaction between grapefruit juice and phenytoin in
healthy male volunteers and epileptic patients.
AB - The present study was undertaken to determine the effects of grapefruit juice
(GFJ) on the oral bioavailability of phenytoin (DPH). Ten healthy male volunteers
received a single dose of 300 mg of DPH orally with 300 ml of water or fresh GFJ
in a randomized crossover fashion. In both instances, blood sampling was done at
0, 0.5, 1, 2, 4, 6, 9, 12, 24, 48, 72, 96 and 120 h. The study was also carried
out in 10 epileptic patients with uncontrolled seizures even after 3 to 4 weeks
regular therapy of DPH (100 mg three times a day). Blood samples were drawn at 0,
1, 2, 3, 4, 5, 6 and 8 h after DPH with 300 ml of water or fresh GFJ. No
significant difference was observed in any of the pharmacokinetic parameters like
Cmax, Cmin, Tmax, t1/2a, t1/2e and AUC of DPH after GFJ administration as
compared to control values in healthy volunteers and epileptic patients. It is
concluded that GFJ does not affect the oral bioavailability of DPH.
PMID- 10669911
TI - Double-blind placebo-controlled study with citicoline in APOE genotyped
Alzheimer's disease patients. Effects on cognitive performance, brain
bioelectrical activity and cerebral perfusion.
AB - Cytidine 5'-diphosphocholine (citicoline) is a an endogenous intermediate in the
biosynthesis of structural membrane phospholipids and brain acetylcholine.
Citicoline has been extensively used for the treatment of neurodegenerative
disorders associated with head trauma, stroke, brain aging, cerebrovascular
pathology and Alzheimer's disease. In this study we have investigated the
efficacy and safety of the treatment with citicoline versus placebo in patients
with Alzheimer disease. Thirty patients (age = 73.0 +/- 8.5 years; range = 57-87
years) with mild to moderate senile dementia (GDS: stages 3-6) of the Alzheimer
type were included in a double-blind, randomized and placebo-controlled clinical
trial. After a 2-week period of drug washout, patients were treated with i)
placebo (n = 17; age = 73 +/- 5 years) or ii) 1,000 mg/day of citicoline (n = 13;
age = 76 +/- 9 years) for 12 weeks (84 days). Examinations were done at baseline
(T0) and after the 12 weeks of treatment (T12). As compared to placebo,
citicoline improved cognitive performance in Alzheimer's disease patients with
APOE E4 (ADAS: difference between groups = -3.2 +/- 1.8 scores, p < 0.05; ADAS
cog: difference between groups = -2.3 +/- 1.5, ns); and this improvement on
cognition was more pronounced (ADAS, p < 0.01; ADAS-cog: difference between
groups = -2.8 +/- 1.3, p < 0.06) in patients with mild dementia (GDS < 5).
Citicoline also increased cerebral blood flow velocities in comparison with
placebo (p < 0.05) when transcranial Doppler recordings from both hemispheres
were considered together, as well as diastolic velocity in the left middle
cerebral artery (p < 0.05). Patients treated with citicoline showed an increase
in the percentage of brain bioelectrical activity of alpha (occipital electrodes)
and theta type (left side electrodes), accompanied by a decrease in relative
delta activity particularly marked in the left temporal lobe. Significant
differences with respect to placebo (p < 0.05) were observed for theta activity
in several fronto-parieto-temporal electrodes of the left hemisphere. Treatment
with citicoline tended to reduce serum IL-1 beta levels, mainly after 4 weeks of
administration, with no modified blood histamine content. In addition, neither
adverse side effects nor alterations in biological and hematological parameters
were induced by citicoline. The present data indicate that citicoline (1,000
mg/day) is well tolerated and improves cognitive performance, cerebral blood
perfusion and the brain bioelectrical activity pattern in AD patients. According
to our results, it seems that citicoline might be a useful treatment in
Alzheimer's disease, and that the efficacy of this compound is greater in
patients with mild mental deterioration and/or bearing the epsilon 4 allele of
the APOE.
PMID- 10669912
TI - Porcine insulin biodegradable polyester microspheres: stability and in vitro
release characteristics.
AB - The stability of porcine insulin in biodegradable polymers, i.e., poly(DL-lactide
co-glycolide) 50:50 (50:50 DL-PLGA) and poly(L-lactide) (L-PLA) was investigated.
Insulin encapsulated microspheres were fabricated from both polymers using double
emulsion-solvent evaporation and emulsion-solvent evaporation techniques and
subjected to accelerated stability studies at 40 degrees C and 75% relative
humidity. Porcine insulin was found to degrade in all microsphere formulations
with an average of < 50% of the initial loading amount remaining intact at the
end of 4 weeks. The two major degradation products observed in these formulations
were determined to be A-21 desamido insulin and covalent insulin dimer with trace
amounts of high molecular weight transformation products. In vitro release
studies in phosphate buffered saline at 37 degrees C resulted in very slow and
incomplete (< 30% in 30 days) release kinetics for all microsphere formulations.
Extraction and analyses of the unreleased insulin within the microspheres
revealed that an average of approximately 11% of the encapsulated insulin
remained intact. The degradation products observed consisted of approximately 15%
of three distinct deamidated hydrolysis products including A-21 desamido insulin,
approximately 22% covalent insulin dimer, and trace amounts of high molecular
weight transformation products. The degradation of porcine insulin within
biodegradable polyester microspheres during stability and release studies can be
attributed to the gradual decrease in the pH within the microspheres due to
progressive polymer hydrolysis resulting in the production of DL-lactic and
glycolic acids. The encapsulation of an acid-base indicator, bromophenol blue, in
50:50 PLGA microspheres (as a probe to estimate pH within the microspheres during
accelerated stability studies) indicated that the pH decreased to approximately
3.8 after 3 weeks.
PMID- 10669913
TI - An evaluation of fluid bed drying of aqueous granulations.
AB - The purpose of the work described was twofold: (a) to apply heat and mass balance
approaches to evaluate the fluid bed drying cycle of an aqueous granulation, and
(b) to determine the effect of the temperature and relative humidity of the
drying air on the ability to meet a predetermined moisture content specification.
Water content determinations were performed using Karl Fischer titration, and
Computrac and Mark 1 moisture analyzers. The water vapor sorption isotherms were
measured using a gravimetric moisture sorption apparatus with vacuum-drying
capability. Temperature, relative humidity, and air flow were measured during the
drying cycle of a production-scale fluid bed dryer. Heat and mass balance
equations were used to calculate the evaporation rates. Evaporation rates
calculated from heat and mass balance equations agreed well with the experimental
data, whereas equilibrium moisture content values provided useful information for
determination of the upper limit for inlet air humidity. Increasing the air flow
rate and inlet temperature reduced the drying time through the effect on the
primary driving force. As expected, additional drying of granules during the
equilibration period did not show a significant impact on reducing the final
moisture content of granules. Reducing the drying temperature resulted in
measurement of higher equilibrium moisture content for the granules, which was in
good agreement with the water vapor sorption data. Heat and mass balance
equations can be used to successfully model the fluid bed drying cycle of aqueous
granulations. The water vapor sorption characteristics of granules dictate the
final moisture content at a given temperature and relative humidity.
PMID- 10669914
TI - Effects of the metal type and the roughness of the die wall on the expended work
for tablet ejection.
AB - The aim of the present work was to obtain an impression about the consequences
for the tableting process when dies of different quality are used. Two hard metal
dies and one die made from tool steel, each with a distinct roughness of the die
wall, were compared by compacting dry-blended powder mixtures on an eccentric
tablet press. The feasibility of the tableting process was assessed by
quantifying the ejection force and the work expended by the lower punch during a
first phase of the ejection process. With decreasing amounts of lubricant, abrupt
permanent impacts were observed leading to conditions at which an ejection was no
longer possible. This observation did not depend on the roughness of the die wall
used or on the compaction pressure, but strongly depended on the metal type of
the die used and on the tested formulation. For the tool steel no difference was
found in this respect between the two tested formulations (0.5% versus 2% silica
aerogel). In either case, a concentration of 0.3% magnesium stearate was
sufficient; however, a concentration of 0.2% magnesium stearate was not
sufficient. For both hard metal dies, concentrations of 0.3% (0.5% silica
aerogel) and 0.5% magnesium stearate (2% silica aerogel) were definitely not
sufficient. Within the ranges above a minimum lubrication, the ejection force and
the ejection work increased with the degree of the die wall roughness on a scale
comparable to that of the tested formulation factors. In particular, if changes
of the die tooling are likely to occur in the life cycle of a product, it is
highly recommended that the quality of the dies be considered in the development
phase.
PMID- 10669915
TI - Influence of crystal habit on the surface free energy and interparticulate
bonding of L-lysine monohydrochloride dihydrate.
AB - The objective of the present study was to apply a technique to measure the
surface energy of crystalline powders without changing the surface properties by
compaction, and to relate such measurements to crystal habit and orientation. The
surface free energy of uncompacted L-lysine monohydrochloride dihydrate (LH),
determined using a modified sessile-drop method, reflected a combined value for
the various faces, and was influenced by the relative size of the faces and the
orientation of the crystals. The surface free energy values obtained from contact
angle measurements were within the possible range calculated from the crystal
structure. Discrepancies between the theoretical estimates of interparticulate
cohesive strengths and those measured from the tensile strength of powder
compacts were used to estimate the flaw sizes (or gaps between the particles)
that act as stress concentrators and reduce the tensile strength of the compacts.
The flaw sizes indicate packing and compressibility of the various crystal
habits. In the absence of compressive load, compacts made out of the
equidimensional crystals have the larger flaw sizes (wider cracks or wider gaps
between the particles). At higher compaction pressures, the compacts from long
rod-shaped crystals have longer crack lengths. The weakness of the compacts made
from the long rods at the higher compaction pressures may be because of the
longer crack length along the interparticulate boundary, which may result in a
higher stress intensity at the crack tip and increased fracture propensity.
PMID- 10669916
TI - Formation and stability of the dispersed particles composed of retinyl palmitate
and phosphatidylcholine.
AB - The purpose of this study was to develop an intravenous formulation composed of
retinyl palmitate (RP) for the treatment of cancer. RP was dispersed with soybean
phosphatidylcholine (PC) using sonication and the dispersal mechanism was
evaluated by characterizing the dispersed particles using dynamic light
scattering, fluorescence spectroscopy, and surface monolayer techniques. The
dispersions in the RP mole fraction range of 0.1-0.8 were stable at room
temperature for 3 days. A limited amount of RP was incorporated into PC bilayer
membranes (approximately 3 mol%). The excess RP separated from the PC bilayers
was stabilized as emulsion particles by the PC surface monolayer. When the PC
content was less than the solubility in RP, the PC monolayer did not completely
cover the hydrophobic RP particle surfaces and separation into oil/water
occurred. The miscibility between RP and PC and the lipid composition were
critically important for the stability of the dispersed particles (coexistence of
emulsion particles [surface monolayer of PC + core of RP] with vesicular
particles [bilayer]) of the lipid mixtures.
PMID- 10669917
TI - Characteristics of pharmaceutical grade phyllosilicate powders.
AB - The purpose of this paper was to evaluate the possible use of three types of
pharmaceutical grades of phyllosilicates as pharmaceutical excipients. Seven
samples (two smectites, three palygorskites, and two sepiolites) were studied. A
complete mineralogical and chemical characterization of each material was made
and powder texture was established by image analysis of scanning electron
micrographs. Powder flow properties were then determined and the influence of
textural characteristics on powder rheology and particle packing was assessed.
Mineral contents were adequate for the sepiolites (> 90% of main mineral) and
smectites (78 and 95%), but should be improved on the palygorskite samples
(around 50% of main mineral in two of the studied samples). According to the
textural characterization, the samples presented almost equal size distributions,
but exhibited two different morphologies (i.e., laminar for smectites and fibrous
for sepiolites and palygorskites). Both sepiolites possessed high flowability,
whereas this factor varied from medium to low in the other materials. The
compressibility of smectites was adequate, whereas that of palygorskites was high
and that of the sepiolites was low. All of the samples studied would be useful as
solid dosage form excipients (some samples would require improvement of their
flow properties or treatment to reduce the amount of mineral impurities).
PMID- 10669918
TI - Characteristics of pharmaceutical grade phyllosilicate compacts.
AB - The purpose of this paper was to determine the possible employment of three
groups of phyllosilicates (two smectites, three palygorskites, and two
sepiolites) as direct-compression tablet excipients. Compact lots of each
material were obtained after application of three different compression loads and
the elastic recoveries and tensile strengths of each lot were then determined.
The results showed that, in comparison with laminar minerals (smectite samples),
fibrous minerals (palygorskites and sepiolites) were found to have lower elastic
recovery, regardless of the compression load. Almost all elastic recovery
happened immediately after the ejection of the compacts. Then, and at least
during the next 24 hr, smectite compacts maintained their dimensions without any
significant variation, whereas fibrous compacts tended to continue increasing
slightly their dimensions. On the other hand, compacts made with laminar
particles had higher mechanical strength than those made with fibrous particles,
except for one sepiolite sample in which the strength was similar. Both particle
morphologies and the presence or absence of hydration water molecules were taken
into account in order to explain these differences. According to the compact
properties measured, at least two of the noncommercial samples (smectite from
Gador, Spain, and sepiolite from Vicalvaro, Spain) would be useful as direct
compression tablet excipients.
PMID- 10669919
TI - Tablet and capsule hydrophilic matrices based on heterodisperse polysaccharides
having porosity-independent in vitro release profiles.
AB - The purpose of the study was to investigate the release-controlling action of a
swellable hydrophilic material based on heterodisperse polysaccharides (HP) in
relation to the initial pore structure of the formulations. HP-based granules
were produced under carefully controlled conditions and compacted into matrix
tablets having equivalent tablet thickness. Quantification of pore structure
using mercury porosimetry showed that the tablets had substantially different
pore volumes and pore size distributions. Dissolution studies demonstrated that
release of a water-soluble model compound, benzamide, from swollen matrices was
affected neither by total porosity nor median pore diameter of the initial dry
matrix. To extend the concept of porosity-independent release further, HP-based
formulations containing either diclofenac sodium or propranolol HCl were
contained within hard gelatin capsules in the form of uncompacted granules. This
produced a dosage form with a high intraparticulate porosity in the dry state.
Equivalent weights of the same formulations were also compacted into tablets. The
in vitro release profiles from matrix tablets compacted from any of the
formulations did not differ significantly from release profiles obtained when the
same materials were contained uncompacted in hard gelatin capsules.
PMID- 10669920
TI - Waxy corn starch: a potent cofiller in pellets produced by extrusion
spheronization.
AB - The purpose of this study was to assess the usefulness of waxy corn (maize)
starch as a cofiller and diluent in pellets produced by aqueous extrusion
spheronization. Waxy corn starch was combined with microcrystalline cellulose
(MCC) in the range of 20-50% of the entire composition. Pellets containing
ordinary corn starch or lactose with MCC were used as reference. The shape of
pellets was characterized using an optical microscopic image analysis system. The
surface and cross-sectional structure were investigated by means of scanning
electron microscopy (SEM). The replacement of ordinary corn starch by waxy corn
starch made it possible to increase the amount of starch from 20 to 40%. The
pellets containing 50% waxy corn starch were of poorer quality but superior to
those containing 30% corn starch. The surface structure became slightly more
irregular with respect to the amount of either starch, and a cavity was formed
inside the pellet during the spheronization. The origin of starch did not affect
the surface structure of the pellets. Waxy corn starch is a potential cofiller:
the amount of MCC can be reduced in pellets produced by extrusion-spheronization
by using waxy corn starch as a cofiller. This enables the reduction of the
manufacturing cost of pellets with low drug load.
PMID- 10669922
TI - Color as an indicator of the organization and compactibility of binary powder
mixes.
AB - The aim of this study was to relate the color of several binary mixes to their
organization as observed by scanning electronic microscopy, and to their
compactibility. Binary mixes of niflumic acid (yellow) with ethyl cellulose,
hydroxypropylmethylcellulose, low-substituted hydroxypropylcellulose (L-HPC), and
ibuprofen (all white) were prepared using different particle size ranges. Colors
of the mixes were determined by diffuse reflectance spectroscopy using a
chromameter. Linear correlation was observed between the yellowness
index/whiteness index ratio (Y/W ratio) defined by the American Society for
Testing and Materials (ASTM) standards and the mean particle size difference of
the materials which governs the organization of the blend. Except for the least
interacting mix, the niflumic acid/L-HPC series, the color of the blend was also
related to the tensile strength of the tablets made from the binary mixes. Color
could be an interesting indicator of the organization of a powder mix. Diffuse
reflectance spectroscopy could be used as a quality control tool because any
modification of the color of the mix may be an indicator of a modification of its
compactibility.
PMID- 10669923
TI - Adsorption of esters of p-hydroxybenzoic acid by filter membranes: mechanism and
effect of formulation and processing parameters.
AB - The adsorption of esters of p-hydroxybenzoic acid (parabens) by filter membranes
was studied by a flow-through technique. The hydrophobic effect was the major
mechanism of adsorption. Propylparaben was more extensively adsorbed by all the
membranes than was methylparaben. Hydrophobic membranes exhibited the greatest
degree of adsorption, whereas adsorption was minimal for hydrophilic membranes.
The charge of the filter membrane did not affect paraben adsorption. Formulation
factors studied included the concentration of paraben, the presence of a tonicity
modifying agent (sodium chloride, mannitol, glycerin), and the presence of a
chelating agent (edetate sodium). Paraben adsorption was directly related to
paraben concentration. The presence of a tonicity modifier or chelating agent did
not alter paraben adsorption to membrane filters. Processing parameters studied
included flow rate, temperature, autoclaving, flow interruption, and filter
membrane presaturation. Presaturation of the filter membranes for up to 1 hr
reduced but did not eliminate paraben adsorption during simulated use.
Interrupting the flow of the paraben solution through the filter membrane allowed
for additional paraben adsorption and caused the concentration of paraben in the
restarted filtrate to be less than 100% of theory.
PMID- 10669921
TI - Mucoadhesive DL-lactide/glycolide copolymer nanospheres coated with chitosan to
improve oral delivery of elcatonin.
AB - The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide
copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the
physiological activity following oral administration. The desired PLGA
nanospheres with elcatonin were prepared by the emulsion solvent diffusion method
to coat the surface of the resultant nanospheres with a mucoadhesive polymer such
as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive
properties were evaluated by measuring the nanospheres adsorbed to a rat everted
intestinal sac (in vitro). The chitosan-coated nanospheres showed higher
mucoadhesion to the everted intestinal tract in saline than the other polymer
coated nanospheres. There was no mucoadhesion site-specificity of the chitosan
coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug
in the chitosan-coated nanospheres was successfully increased by using the
solvent diffusion method in oil. The pattern of drug release of the resultant
nanospheres did not differ markedly from that of uncoated nanospheres. The
chitosan-coated nanospheres with elcatonin were administered intragastrically to
fasted Wistar rats. The chitosan-coated nanosphere reduced significantly the
blood calcium level compared with elcatonin solution and uncoated nanospheres,
and the reduced calcium level was sustained for a period of 48 hr. Even under
nonfasting conditions, the mucoadhesion of chitosan-coated nanospheres was
unaltered and the reduction in blood Ca levels was maintained satisfactorily.
PMID- 10669924
TI - Hydraulic high-pressure nebulization of solutions and dispersions for respiratory
drug delivery.
AB - The purpose of this investigation was to assess hydraulic high-pressure
nebulization as a means for respiratory drug delivery. A hydraulic high-pressure
nebulizer was designed and constructed. In a design study, the output efficiency
and the aerosol particle size were determined for the nebulizer as a function of
nozzle diameter (5, 10, and 20 microns), gas flow rate (2 and 8 l/min), applied
hydraulic pressure (2200 and 4000 psig), and distance between the nozzle orifice
and impaction surface (0.25-4 cm) with an aqueous solution of fluorescein. The
output efficiency was also measured with an ethanol solution and an aqueous
phospholipid dispersion of liposomes. For the design study, each factor had an
effect. The efficiency tended to increase with a decrease in the nozzle diameter,
although the differences between the 5- and 10-micron nozzle were more sensitive
to the air flow rate and nozzle-to-impaction-surface distance. Greater
efficiencies were always obtained at the higher ancillary air flow rates.
Operating the nebulizer at different pressures caused a change in the functional
relationship between the efficiency and the nozzle-to-impaction-surface distance.
For the 5-micron nozzle at high pressure, efficiency fell with increasing nozzle
to-impaction-surface distance, whereas for the data obtained with the 20-micron
nozzle, the efficiency increased with nozzle-to-impaction-surface distance, with
lower efficiencies obtained at the higher pressures. For the remaining
observations made with the 5- and 10-micron nozzles, the efficiency as a function
of nozzle-to-impaction-surface distance appeared to be variable. For the 5- and
10-micron size nozzle, there was no significant effect of the air flow rate,
pressure, or nozzle-to-impaction-surface distance on the mass median aerodynamic
diameter and geometric standard deviation. For the 20-micron size nozzle, the
particles were not completely dried. Ethanol solutions gave somewhat higher
efficiencies, whereas the phospholipid dispersion gave efficiencies comparable to
the aqueous solutions nebulized under similar conditions. The efficiency of the
hydraulic high-pressure nebulizer appears to be correlated with the calculated
properties of the liquid jet. For respiratory drug delivery, the hydraulic high
pressure nebulizer provides reasonably high outputs of respirable particles
independent of time from a single pass of liquid through the nebulizer.
PMID- 10669925
TI - The effect of lyophilization on plasmid DNA activity.
AB - The effect of lyophilization of plasmid DNA's ability to express an encoded
protein was studied. Plasmid DNA, pRL-CMV expressing Renilla luciferase, was
purified and stored in Tris-ethylenedi-aminetetraacetic acid (EDTA) buffer.
Aliquots of the plasmid were lyophilized using analytical equipment, both alone
and in the presence of carbohydrate. Samples were rehydrated and subject to
functional and structural analyses. Analytical techniques included transfection
efficiency in COS-1 cells, agarose gel electrophoresis, dimethylethylenediamine
(DMED) assay for abasic sites, circular dichroism measurement, and UV
spectroscopy. The lyophilization of pRL-CMV plasmid DNA resulted in a
statistically significant loss of transfection efficiency (p < 0.05). Mono- and
disaccharides could completely restore transfection efficiency. Agarose gel
electrophoresis and the DMED assay demonstrated no change in gross plasmid
structure or increase in abasic sites during lyophilization, respectively.
Changes in DNA form, as measured by a change in ellipsisity, were observed on
lyophilization. However, these changes were transient and were not shown to be
responsible for loss of transfection efficiency. A hyperchromic effect was
observed at 260 nm after lyophilization and could be reversed by the presence of
carbohydrates. Lyophilization causes a decrease in plasmid DNA activity as
measured by an in vitro transfection assay. Carbohydrates can ameliorate this
decreased activity, which may be due to structural changes seen during the
lyophilization process.
PMID- 10669926
TI - Assessment of the myotoxicity of pharmaceutical buffers using an in vitro muscle
model: effect of pH, capacity, tonicity, and buffer type.
AB - The purpose of the present study was to investigate the myotoxicity of three
buffers containing carboxylic acid groups (i.e., acetate, succinate, and citrate)
as a function of their pH, capacity, and tonicity. The myotoxicity of these
buffers in the range of pH 2-6 and 0.001-0.1 M buffer capacity was assessed using
cumulative creatine kinase (CK) release from an isolated rodent muscle model
following injection. Phenytoin and 0.9% NaCl injection were used as positive and
negative controls, respectively. Buffer solutions were prepared. A lower pH and
higher buffer capacity was linked to increased myotoxicity for the acetate
buffers. However, for succinate and citrate buffers, pH appeared to influence the
extent of myotoxicity, whereas buffer capacity did not seem to have an effect.
When either NaCl or trehalose was used as a tonicity-adjusting agent at pH 6,
isotonic 0.01 M buffer solutions dramatically lowered the cumulative CK release
compared to those that were not isotonic. Isotonic succinate buffers displayed
the lowest myotoxicity, whereas citrate buffers displayed the highest values.
Citrate buffers containing three carboxylic acid groups showed higher myotoxicity
than succinate buffers and acetate buffers at 0.001 and 0.01 M buffer capacities,
whereas acetate buffer produced higher cumulative CK release than citrate and
succinate buffers at 0.1 M buffer capacity. The myotoxicity of pharmaceutical
buffers containing carboxylic acid groups appears to be directly affected by
lowering the pH of the solution.
PMID- 10669927
TI - Influence of drying temperature and granulation liquid viscosity on the inter-
and intragranular drug migration in tray-dried granules and compacts.
AB - The influence of the drying temperature and granulation liquid viscosity on the
inter- and intragranular migration of a poorly water-soluble compound in a
granulation mass and in a compact was quantitatively assessed. The intergranular
migration kinetics were investigated by evaluating the drug distribution at
different drying-time intervals. The results were analyzed by use of two-factor,
three-level, face-centered, central composite designs. Riboflavin was mixed with
alpha-lactose monohydrate 90 M and granulated with distilled water, except for
the viscosity experiments in which an aqueous polyvinylpyrrolidone (PVP)
(Kollidon K90) solution was used. The wet granules were dried in a hot-air oven
or compacted prior to drying. The drug concentration at different locations
inside the granulated mass and the compacts after drying was determined
spectrophotometrically and by use of diffuse light reflectance measurements. The
riboflavin distribution in the granulation masses and in the compacts was
characterized by drug-enriched outer layers and drug-depleted inner regions,
indicating a strong migration phenomenon. It was clear that the drying
temperature had no influence on the inter- and intragranular drug distribution.
The intergranular migration was avoided using the PVP as a binder in the
granulation liquid, whereas a minimal granulation liquid viscosity of 100 mPa.sec
was necessary to avoid the intragranular migration. The diffuse light reflectance
measurements can be used for the in-process control of granule samples containing
low drug concentrations without the destruction of the samples.
PMID- 10669928
TI - Biochemical and morphological identification of ceramide-induced cell cycle
arrest and apoptosis in cultured granulosa cells.
AB - We have investigated the effects of ceramide on the progression of cell cycle and
on apoptotic cell death in ovarian cultured granulosa cells. Rates of cellular
proliferation were measured by immunocytochemical staining for proliferating cell
nuclear antigen (PCNA) and flow cytometric cell cycle analysis. We also examined
for morphological and biochemical signs of apoptosis. The PCNA expression was
downregulated in a dose-dependent manner after treatment with C6-ceramide. Flow
cytometric analysis demonstrated that the exposure of granulosa cells to C6
ceramide markedly decreased the population associated with G0/G1 DNA content and
the reduction of cell numbers in G0/G1 phase was accompanied by the elevation of
the A0 phase. The exposure of granulosa cells to exogenous C6-ceramide induced
drastic morphological changes including cytoplasmic- or nuclear condensation and
typical apoptotic DNA degradation. We also observed that phorbol 12-myristate 13
acetate, a protein kinase C (PKC) activator, significantly inhibited the ceramide
induced apoptosis. These results suggested that ceramide might block the
progression of cell cycle at G0/G1 phase and as a consequence, granulosa cells
would be committed to apoptosis. Our findings also indicated that down-regulation
of the PKC activity might be involved in the ceramide-induced apoptosis in
cultured granulosa cells.
PMID- 10669929
TI - Increased expression of VE-cadherin correlates temporally with differentiation of
a restrictive endothelial barrier during normal angiogenesis in vivo.
AB - The purpose of this study was to evaluate temporal expression of VE- and N
cadherins within the angiogenic chick chorioallantoic membrane (CAM). Whether
their relative patterns of expression changed in conjunction with abrupt
differentiation of the restrictive CAM endothelial barrier between days 4.5 and
5.0 of the 21 days gestation was evaluated. Immunoblots against VE-cadherin
depicted an increase of VE-cadherin expression between days 4.5 and 5.0, but no
change in expression was detected between days 5.0 and 6.0. N-cadherin
expression, on the other hand, remained uniform from day 4.5 to day 6.0.
Immunogold-labeled anti-VE-cadherin was found exclusively on the CAM endothelium,
and principally along the lateral inter-endothelial junctions. Hence, VE-cadherin
expression by the angiogenic endothelium was similar to that of adult
endothelium. That VE-cadherin expression by the CAM endothelium was increased
between days 4.5 and 5.0 serves to suggest a temporal correlation with the
ontogeny of restrictive barrier function in angiogenic endothelium in vivo.
PMID- 10669930
TI - Human chondrocyte cell lines from articular cartilage of metatarsal phalangeal
joints.
AB - Chondrocytes can be isolated from human adult cartilage from metatarsal
phalangeal joints. After enzymatic digestion to isolate viable cells, confluent
monolayers were obtained 2-4 weeks after the start of cell division. Chondrocytes
cultures, initiated and maintained in HAM's F12 with bovine fetal serum without
the addition of other growth factors, produced in vitro a matrix rich in collagen
and proteoglycans. Although several studies reported phenotypic instability, our
results showed that the cell retain for more than 5 months in culture their
differentiated characteristics, including the ability to produce cartilage
specific molecules. Chondrocyte cell lines should be useful in studying the
functions of these cells from normal and abnormal tissue and for pharmacological
studies in vitro.
PMID- 10669931
TI - Tight junction of sinus endothelial cells of the rat spleen.
AB - The fine structure of the tight junctions between sinus endothelial cells of the
rat spleen and the permeability of such sinus endothelial cells were examined by
transmission electron microscopy, using freeze-fracture, triton extraction, and
lanthanum-tracer techniques. In freeze-fracture replicas, the segmented strands
and grooves of the tight junctions were frequently observed on the basolateral
surfaces of the sinus endothelial cells irrespective of the location of the ring
fiber. There were one or two wavy-strands or grooves which were, for the most
part, oriented parallel to the long cell axis thus forming networks at places. In
addition, some strands or grooves were discontinuous while some networks of the
junctional strands were not closed. These strands also occasionally lacked
intramembranous particles in the tight junctions. The junctional strands run
apicobasically at certain sites. In the vertical sections of the sinus
endothelial cells treated with lanthanum nitrate, although no tight junctions
were observed wherever the endothelial cells were apposed, most of them were
situated on the basal part of the lateral surfaces of the adjacent endothelial
cells. Several fusions of the junctional membranes were observed in a vertical
section of the lateral surfaces of the adjacent endothelial cells. The
intercellular spaces of the adjacent endothelial cells except for the fusion of
the junctional membranes, were electron dense and the infiltration of lanthanum
nitrate was found not to be interrupted by these tight junctions. Based on these
observations, the molecular 'fence' and paracellular 'gate' functions of the
tight junctions in the sinus endothelial cells are discussed.
PMID- 10669932
TI - Effects of prolonged ACTH-stimulation on adrenocortical accumulation of
lipofuscin granules in aged rats.
AB - Subcellular deposition of lipofuscin granules is a marker of aging. Human and
rodent adrenal cortices accumulate lipofuscin granules with age, but the
mechanism that leads to the accumulation is not known. The ultrastructural
appearance of lipofuscin granules resembles that of secondary lysosomes. Since
adrenocortical subcellular events are predominantly influenced by ACTH action, we
therefore studied the effect of prolonged ACTH-stimulation on adrenocortical
accumulation of secondary lysosome-like granules, designated herein as lipofuscin
granules. Using aged Fischer 344 male rats as a model, we found that a 7 day ACTH
stimulation exerts a reducing effect on adrenocortical lipofuscin accumulation.
Thus, adrenocortical accumulation of lipofuscin granules with age in vivo may not
be an irreversible process.
PMID- 10669933
TI - Desmosomal proteins in cultured and intact human periodontal ligament
fibroblasts.
AB - This study examined the kinds of desmosomal proteins in the human periodontal
ligament fibroblasts (PDLFs). The PDLFs obtained from young and older patients
were cultured and the amounts of desmosomal proteins were measured by ELISA with
antibodies to desmoplakins, desmogleins, and desmocollins. Cultured cells and
tissue sections of the human periodontal ligament were immunostained with the
same antibodies. Expression of desmosomal proteins in the PDLFs was clearly
demonstrated both by ELISA and the immunohistochemical studies, suggesting the
existence of desmosome-like junctions in the PDLFs. The junctions are considered
to protect gap junctions in the PDLFs against cell transformation caused by cell
contraction, which may relate to tooth eruption and repair of periodontal tissue,
and/or strong occlusal forces. Statistically significant differences (P < 0.0001)
in the expression of desmoplakins and desmogleins between younger and older
patients were observed in this study.
PMID- 10669934
TI - Distribution of actin bundles in Bowman's capsule of rat kidney.
AB - In this study we define the distribution of actin bundle arrangement in Bowman's
capsule of rat renal corpuscles. Parietal cells of Bowman's capsule were examined
by conventional light microscopy, electron microscopy and confocal microscopy.
Within each parietal cell individual actin bundles are arranged in a parallel
fashion running the length of the cell. Computer reconstructions obtained using
confocal microscopy clearly show the lengths of actin bundles to be arranged, on
a capsule level, end-to-end, at angles and perpendicular to bundles in adjacent
cells. The bundles stain positively for non-muscle myosin and vinculin. The
presence and arrangement of actin bundles in parietal cells is consistent with a
role in reinforcing capsule structure.
PMID- 10669935
TI - Immunolocalization of androgen receptors in testicular cells during postnatal
development of the bank vole (Clethrionomys glareolus, S.).
AB - Determination of the cellular distribution of the androgen receptors within the
testis is of great importance for an understanding of their essential role in
mediating of androgen action in the male gonad. In bank voles, which are
seasonally breeding rodents, photoperiod is one of the most important factors
inducing profound changes in the morphology and hormonal activity of the testes.
Immunolocalization of androgen receptors was found in all somatic cells such as
Sertoli cells, Leydig cells, and peritubular-myoid cells, however, distribution
of the androgen receptors in various cell types depended on age of animals.
Intensity of immunoreactivity was noticed as age and photoperiod-dependent. Males
reared under different light regimes showed a significant correlation between the
length of light and sexual maturation. Therefore, morphology of the testis from
young and adult bank voles was also presented.
PMID- 10669936
TI - The current prospects for neutrophil transfusions for the treatment of
granulocytopenic infected patients.
AB - Infection continues to be a major cause of morbidity and mortality in patients
undergoing aggressive chemotherapy and hematopoietic stem cell transplantation.
The provision of normal neutrophils to such patients is a logical therapeutic
approach, the success of which will likely be dependent on the dose of
neutrophils provided. Stimulation of normal leukapheresis donors with G-CSF or
dexamethasone causes marked neutrophilia and results in the collection of greatly
increased numbers of neutrophils. Transfusion recipients, on average, exhibit
large posttransfusion neutrophil increments that are sustained for 24 hours.
These cells are capable of migrating to extravascular sites. Although the
preliminary clinical impressions are encouraging, the clinical efficacy of
transfusing large numbers of neutrophils will have to be determined by randomized
controlled clinical trials.
PMID- 10669937
TI - Mechanisms and new approaches for the allogeneic blood transfusion-induced
immunomodulatory effects.
PMID- 10669938
TI - Prestorage versus poststorage white cell reduction for the prevention of the
deleterious immunomodulatory effects of allogeneic blood transfusion.
PMID- 10669939
TI - Leukocyte reduction of blood components: public policy and new technology.
PMID- 10669940
TI - Camouflaged blood cells: low-technology bioengineering for transfusion medicine?
AB - The small number of studies done on the covalent modification of RBC with PEG, or
PEG-derivatives, suggests that the immunocamouflage of intact cells significantly
reduces the antigenicity and immunogenicity of the foreign cell. Importantly,
this protective immunologic effect can be accomplished without adversely
affecting the structure, function, or viability of the modified cell (e.g., RBCs
and lymphocytes). As a consequence, PEG-RBC may have significant practical value
in the treatment of the chronically transfused patient as a prophylactic measure
against allosensitization. The PEG-RBC also may be useful in treating the already
allosensitized individual. As shown, preexisting antibodies do not effectively
recognize nor bind to the modified donor cells. A finding of further interest to
transfusion medicine is that pegylation of contaminating lymphocytes within RBC
products may prove efficacious in preventing graft-versus-host disease in the
immunocompromised patient. However, the main emphasis of our research continues
to be the immunocamouflage of RBC for use in chronic transfusion therapy of the
SCD and thalassemic patient.
PMID- 10669941
TI - Risk of hepatitis A virus infection in persons with hemophilia receiving plasma
derived products.
PMID- 10669942
TI - What we can learn from national and international platelet serology workshops.
PMID- 10669943
TI - Position-independent expression of transgenes in zebrafish.
AB - The variability in expression patterns of transgenes, caused by the influence of
neighboring chromatin, is called 'position effect'. Border elements are DNA
sequences, which have the ability to alleviate position effects. The abilities of
two types of border elements, scs/scs' from the D. melanogaster 87A7 heat shock
locus and the A-element from the chicken lysozyme gene, to protect transgenes
from position effects were quantified in developing zebrafish embryos. The
transgenic construct used was FV3CAT, which consists of the carp beta-actin
transcriptional regulatory region, the chloramphenicol acetyltransferase (CAT)
gene and the 3'-untranslated region from the Chinook salmon growth hormone gene.
FV3CAT constructs flanked by either scs/scs'-elements or A-elements were
introduced into zebrafish chromosomes and the spatial and temporal expression
patterns of the transgenes were quantified in multiple generations of transgenic
zebrafish. Levels of transgene expression were uniform in the pre-differentiated
and fully differentiated populations of cells present during embryonic
development. Levels of transgene expression were proportional to the numbers of
integrated transgenes. Expression of transgenes per cell varied less than two
fold in different transgenic lines. Both types of border elements were able to
prevent the influences of neighboring chromatin on transgene expression through
three generations of fish. The results are consistent with the ability of border
elements to function with equal efficiencies in the many cell types found in
vertebrates. Thus, inclusion of border elements in genetic constructs can provide
reliable and reproducible levels of gene expression in multiple lines of fish.
PMID- 10669944
TI - Zona pellucida glycoprotein mZP3 produced in milk of transgenic mice is active as
a sperm receptor, but can be lethal to newborns.
AB - Mouse egg zona pellucida glycoprotein mZP3 (approximately 83 kDa M(r)) serves as
a species-specific sperm receptor and acrosome reaction-inducer during
fertilization in mice. These biological activities are dependent on certain mZP3
serine/threonine- (O-) linked oligosaccharides present at the combining-site for
sperm. In an attempt to produce large amounts of biologically active mZP3, we
generated several transgenic mouse lines carrying the full-length mZP3 gene fused
to the beta-casein gene promoter and transcription termination sequence. We found
that different transgenic mouse lines have different amounts of recombinant mZP3
(approximately 63 kDa M(r)) in milk of lactating females, from approximately 0.3
to 3.5 micrograms/microliter of milk. In all cases, purified milk-mZP3 is active
as a sperm receptor and acrosome reaction-inducer in vitro. Unexpectedly, we also
found that development of litters from these transgenic mice is related to the
amount of mZP3 in the mother's milk. In the most extreme case, litters from the
highest expressers fail to live beyond about day-7 post partum unless placed
immediately after birth with surrogate wild-type mothers. Litters from lower
expressers initially display a complex phenotype that includes effects on hair
and body growth, but some of the mice survive and, in time, are restored to a
wild-type phenotype. These results demonstrate that relatively large amounts of
biologically active mZP3 can be produced in transgenic mouse milk for structural
and other studies, but that the presence of mZP3 in milk has dramatic
developmental effects on litters, ranging from retarded hair and body growth to
death of newborn pups.
PMID- 10669945
TI - Codon optimization, genetic insulation, and an rtTA reporter improve performance
of the tetracycline switch.
AB - The objective of this work was to further develop a tetracycline repressor (TetR)
protein system that allows control of transgene expression. First, to circumvent
the need for a binary approach, a single plasmid design was constructed and
tested in tissue culture. To indirectly assay integrations that express the
synthetic transcription factor (rtTA), a bicistronic gene was built which
included an internal ribosome entry site (IRES) and a green fluorescent protein
coding region (GFP) on the same expression cassette as the coding region of rtTA
(pTetGREEN). This construct did not produce fluorescent colonies when stably
integrated and provided minimal expression of GFP in the face of adequate
expression of rtTA. The coding region for TetR was then altered by introducing
156 silent point mutations to simulate mammalian genes. Replacement of wild-type
TetR gene (tetR) in pTetGREEN with 'mammalianized' tetR provided GFP expression.
Adjustment of codon usage in the tetR region of rtTA nearly doubled the
expression level of functional rtTA. To increase the number of rtTA expressing
lines, the chicken egg-white lysozyme matrix attachment region (MAR) was
introduced into the single plasmid design just upstream of the tetracycline
operators (tetO). Inclusion of the MAR doubled the number of colonies that
expressed rtTA (44% vs 88%). With the modifications described here, the number of
lines that express rtTA and provide induction from a single plasmid design can be
increased by the inclusion of a MAR and the level of rtTA expression can be
further increased by adjusting the base composition of the TetR coding region.
The MAR also insulates the inducible gene from the promoter driving rtTA.
PMID- 10669946
TI - Production of transgenic rats using cryopreserved pronuclear-stage zygotes.
AB - We investigated the application of cryopreserved pronuclear-stage zygotes for the
production of transgenic rats. Most of the pronuclear-stage zygotes cryopreserved
by conventional two-step freezing or vitrification appeared morphologically
normal, but the proportion of frozen zygotes that developed into fetuses
following transfer (59.7-60.2%) was higher than that of vitrified zygotes (5.5
22.1%). When the frozen-thawed zygotes were used for DNA microinjection, 97.5%
survived after DNA microinjection and 25.1% of the transferred zygotes developed
into fetuses. These proportions were comparable to those of the fresh control
zygotes (97.0 and 30.0%, respectively). The integration efficiency of the
exogenous DNA into fetuses was similar between the frozen group (3.3% per
injected zygote) and the control group (3.5%). These results indicate that
pronuclear-stage rat zygotes can be successfully cryopreserved by conventional
two-step freezing for production of transgenic rats.
PMID- 10669947
TI - Angiogenesis at the interface between basic and clinical research.
AB - The field of antiangiogenesis has shown a remarkably rapid evolution from the
discovery at the bench to translation into the clinic. Currently a wide variety
of compounds are in clinical trial as inhibitors of angiogenesis, and new
compounds are being frequently added. The target cell of most angiogenesis
inhibitors is the endothelial cell, with inhibitors that selectively affect a
number of endothelial cell functions acquired during angiogenesis, including
activation, proliferation, migration, invasion and survival. The endothelial cell
may also be targeted by chemotherapeutic agents currently in use. The high doses
and intermittent treatment schedules used to fight resistant tumor cells may be
altered towards lower doses and chronic administration to obtain selective
inhibition of angiogenic factor-stimulated endothelial cells as adjuvant therapy.
Finally, gene therapy is a promising route for the delivery of novel protein
inhibitors of angiogenesis, and is actively being investigated.
PMID- 10669948
TI - Models for studying angiogenesis in vivo.
AB - In vivo and in vitro techniques are available for research on the functions of
endothelial cells during angiogenesis. In this review we describe and evaluate
the methodology and specific features of some of the most frequently used in vivo
assays.
PMID- 10669949
TI - Biological parameters for the choice of antiangiogenic therapy and efficacy
monitoring.
AB - Angiogenesis is a tightly controlled process which depends on the balance between
stimulating and inhibiting factors. When this balance is disrupted, angiogenesis
acquires a pathological meaning. The list of molecules able to induce
angiogenesis is heterogeneous with respect to their chemical characteristics and
biological properties. Quantitative measurement of tumor angiogenesis is
necessary for the choice of therapeutic strategies and as an endpoint for
antiangiogenic therapy. We are developing a quantitative RT-PCR with measures the
expression of specific factors in real time. With the use of this rapid
technique, measurement of the expression of the angiogenic factors and inhibitors
is also possible in specimens as small as biopsies.
PMID- 10669950
TI - Assessment of tumor vascularization: immunohistochemical and non-invasive
methods.
AB - Growth of solid tumors beyond a certain mass is dependent on the vascular bed
from pre-existing host vasculature. The process of angiogenesis is essential not
only for primary tumor growth but also for metastasis. The number of microvessels
within the invasive component of a primary tumor reflects the degree of tumor
angiogenesis. At present the most widely used method to assess neovascularization
is the quantitation of intratumoral microvessel density (IMD) by
immunohistochemical methods in which specific markers for endothelial cells are
employed. In this paper we analyze the different methods used to assess IMD, as
well as their advantages and potential methodological pitfalls. Several studies
have shown a close correlation between IMD, tumor growth and the occurrence of
metastasis, suggesting that IMD is a prognostic indicator of clinical relevance.
Furthermore, preliminary studies suggest that determination of angiogenesis may
predict responsiveness to some forms of conventional anticancer therapy. Although
the histological microvessel density technique is the current gold standard to
characterize tumor angiogenesis, it may not be the ideal tool for clinical
purposes because it needs to be performed on biopsy material and does not assess
the functional pathways involved in the angiogenic activity of tumors. Non
invasive assessment of tumor vascularity is possible in vivo by means of Doppler
sonography, dynamic contrast-enhanced magnetic resonance imaging (MRI) and
positron emission tomography (PET). These methods may be preferable to
histological assay because they are non-invasive, survey the entire tumor,
reflect both anatomic and physiologic characteristics, and may be useful to
monitor the activity of antiangiogenic therapies.
PMID- 10669951
TI - MMP inhibitors: experimental and clinical studies.
AB - Matrix metalloproteases (MMPs) are a family of structurally related enzymes that
are capable of degrading proteins of the extracellular matrix. These enzymes play
a role in tissue remodelling associated with both physiological and pathogenic
processes. A high expression of MMPs is associated with cancer malignancy: it is
related to the tumor's ability to metastasize and to the process of angiogenesis.
Treatment with MMP inhibitors alone or in combination with cytotoxic therapy is
an interesting novel approach to control tumor progression. The expected
mechanism of action of these compounds and the difference in side effects
compared to cytotoxic drugs make the definition of endpoints and the assessment
of response difficult. Furthermore, it is not yet clear whether tumor
vascularization or, more specifically, MMP expression/activation should be a
criterion of eligibility for this kind of treatment. This review provides an
overview of the characteristics of MMPs and their role in tumor progression,
metastasis and angiogenesis. Preclinical and clinical studies with synthetic MMP
inhibitors are described. The presence of MMPs in biological fluids of patients
and their use in prognostic evaluation and in determining the efficacy of
treatment with MMP inhibitors is discussed.
PMID- 10669952
TI - Angiosuppression and chemotherapy: strategies aimed at their integration in
cancer patients.
AB - A number of antiangiogenic agents have been developed as pharmaceuticals and are
currently being tested in clinical studies. Potential strategies to enhance the
activity of angiogenesis inhibitors could be to combine them, or better still, to
administer them either sequentially or concurrently with cytotoxic drugs.
Chemotherapy would be a more appropriate initial choice for patients with
advanced disease since cytostatic agents can induce a fast regression of the
tumor and cancer-related symptoms. Antiangiogenic treatment could be used after
chemotherapy in patients who achieve disease remission to prolong the time to
progression, the symptom-free interval and the overall survival. Antiangiogenic
treatment is likely to attain an important role in the adjuvant setting. In fact,
it could be used for prolonged periods after radical surgery to maintain dormancy
of residual tumor cells. In spite of these promising preclinical data, several
points need to be clarified before the initiation of clinical trials. In fact,
certain misconceptions may interfere with their optimum design and result
analysis.
PMID- 10669953
TI - In vitro models of angiogenesis: the use of Matrigel.
AB - Tumor-induced angiogenesis is a key event for neoplastic progression. In vitro
assays are important for identification of potential angiogenic agents and rapid
screening for pharmacological inhibitors. The increased interest in this field of
study has generated several in vitro assays that recapitulate the steps of
endothelial cell activation and differentiation. In this short report we
emphasize the utility of Matrigel, a reconstituted basement membrane, to define
two different steps in the angiogenic process: invasion in response to growth
factors and organization of microvessels into a network with branching morphology
on a Matrigel substrate.
PMID- 10669954
TI - Quantitative RT-PCR assay for VEGF mRNA in human tumors of the kidney.
AB - Angiogenesis is the formation of new capillaries from pre-existing vessels, and
recent evidence has demonstrated that tumor growth is controlled mainly by
angiogenesis. Vascular endothelial growth factor (VEGF) is an endothelium
specific growth factor which is strongly angiogenic in vitro and in vivo. We have
developed a quantitative RT-PCR assay for the measurement of VEGF mRNA expression
using a real-time procedure based on the use of fluorogenic probes and the ABI
PRISM 7700 Sequence Detector System. The assay performance of this method in
terms of practicability and reliability is reported with results that seem
promising for its widespread use in the clinical laboratory. The method has been
applied to the measurement of mRNA of VEGF in human renal cell carcinomas (RCC).
Preliminary results show a significantly higher VEGF mRNA expression (ratio
values between 181 and 2222) in tumor specimens compared to non-adjacent, non
tumoral tissue of the same subjects.
PMID- 10669956
TI - Inhibition of angiogenesis by type I interferons in models of Kaposi's sarcoma.
AB - Kaposi's Sarcoma (KS) is a pathology which occurs with increased frequency and in
a particularly aggressive form in AIDS patients. The HIV-1 Tat protein appears to
be an important co-factor in the induction of the extensive neo-vascularization
associated with AIDS-KS. Tat acts as a chemoattractant for endothelial cells in
vitro, inducing both chemotactic and invasive responses. Several clinical trials
have been performed testing the effectiveness of diverse biological agents in
therapy of KS, among these the type I interferons. Type I IFNs have diverse
biological functions besides their anti-viral activity, including anti-angiogenic
properties. We have shown that IFN alpha and IFN beta are potent inhibitors of
both primary and immortalized endothelial cell migration and morphogenesis in
vitro as well as neo-angiogenesis induced by HIV-1 Tat in vivo. The inhibitory
effect of IFN class I on HIV-Tat associated angiogenesis further supports its use
as a therapy for epidemic Kaposi's sarcoma. The use of recombinant IFNs at the
levels required to obtain a therapeutic effect are associated with side effects
and toxicity, therefore we are now developing a gene therapy approach for
constant and local delivery type I IFNs.
PMID- 10669955
TI - Generation of expression plasmids for angiostatin, endostatin and TIMP-2 for
cancer gene therapy.
AB - Antiangiogenic therapy may represent a promising approach to cancer treatment.
Indeed, the efficacy of endogenous angiogenesis inhibitors, including
angiostatin, endostatin and TIMPs, has been demonstrated in many types of solid
tumors in animal models. In view of the possible problems associated with long
term administration of inhibitors as recombinant proteins, we propose their
delivery as nucleic acids through a gene therapy approach. To this end,
eukaryotic expression constructs for murine angiostatin and endostatin as well as
human TIMP-2 were generated, and characterized in vitro. All constructs carry the
relevant cDNAs under the control of the strong HCMV promoter/enhancer, and
cleavable leader signals to allow protein secretion. Expression of the
angiogenesis inhibitors was detected by in vitro transcription/translation
experiments as well as transfection of 293T cells, followed by Western blotting
(WB) or radioimmunoprecipitation analysis of both cell lysates and supernatants
(SNs). These constructs might be used for in vivo intramuscular delivery of
plasmid DNA and as a set of reagents for the development of retroviral as well as
adeno-associated viral (AAV) vectors expressing angiogenesis inhibitors.
PMID- 10669957
TI - Endostatin: a promising drug for antiangiogenic therapy.
AB - Angiogenesis, the formation of new blood vessels from existing capillaries, is
critical for tumors to grow beyond a few in size. Tumor cells produce one or more
angiogenic factors including fibroblast growth factor and vascular endothelial
growth factor. Surprisingly, antiangiogenic factors or angiogenesis inhibitors
have been isolated from tumors. Some angiogenesis inhibitors, such as
angiostatin, are associated with tumors while others, such as platelet-factor 4
and interferon-alpha are not. Endostatin, a C-terminal product of collagen XVIII,
is a specific inhibitor of endothelial cell proliferation, migration and
angiogenesis. The mechanism by which endostatin inhibits endothelial cell
proliferation and migration is unknown. Endostatin was originally expressed in a
prokaryotic system and, late, in a yeast system, thanks to which it is possible
to obtain a sufficient quantity of the protein in a soluble and refolded form to
be used in preclinical and clinical trials.
PMID- 10669958
TI - The role of the thiol N-acetylcysteine in the prevention of tumor invasion and
angiogenesis.
AB - We have extensively studied the effects of N-acetylcysteine (NAC), a
cytoprotective drug that can prevent in vivo carcinogenesis. Here we review our
findings NAC completely inhibits gelatinolytic activity of metalloproteases and
chemotactic and invasive activities of tumor cells. In addition, NAC reduces the
number of lung metastases when malignant murine melanoma cells are injected into
nude mice. NAC treatment decreases the weight of primary tumors and produces a
dose-related increase in tumor latency. Moreover, oral administration of NAC
reduces the formation of spontaneous metastases. In experimental metastasis
assays, we have found a synergistic reduction in the number of lung metastases
after treatment with doxorubicin (DOX) and NAC in nude mice. In tumorigenicity
and spontaneous metastasis assays, the combined administration of DOX and oral
NAC again has shown synergistic effects on the frequency and weight of primary
tumors and local recurrences and completely prevented the formation of lung
metastases. The addition of NAC to endothelial cells strongly reduces their
invasive activity in response to angiogenic stimuli. NAC inhibited the
degradation and release of radiolabeled type IV collagen by activated endothelial
cells, indicating that NAC blocks gelatinase activity. Oral administration of NAC
reduces the angiogenic response induced by KS tumor cell products, confirming the
ability of NAC to inhibit the invasive activity of endothelial cells in vivo and
thereby blocking angiogenesis.
PMID- 10669959
TI - Student report--the fight against cancer and angiogenesis inhibitors: are we
entering a new era?
AB - Chemoresistance is currently the main cause of failure in the treatment of cancer
which, despite extensive research, remains unsolved. In this report the
theoretical assumptions underlying antiangiogenic therapy are described and
future perspectives and limits are discussed.
PMID- 10669960
TI - Psychoanalysis, psychoanalytic psychotherapy and supportive psychotherapy:
contemporary controversies.
AB - The author explores the controversies involving psychoanalytic psychotherapy from
conceptual, clinical and educational perspectives. He proposes an integrated
concept of psychoanalytic modalities of treatment, and their subdivision into
standard psychoanalysis, psychoanalytic psychotherapy and psychoanalytically
based supportive psychotherapy. Indications and contra-indications for these
therapeutic approaches are outlined in the light of clinical experience and
psychoanalytic research on these issues. It is proposed that psychoanalytic
institutes teach psychoanalytic psychotherapy to candidates in psychoanalytic
training. The author stresses that we now possess a broad spectrum of
psychoanalytically based approaches to patients that significantly expand the
therapeutic effectiveness of our profession, and thus can strengthen the social
impact of psychoanalysis.
PMID- 10669961
TI - Disappointment and disappointedness.
AB - The author argues that the widespread affective experience of disappointment has
not received the analytic attention it deserves, and that this is particularly
the case for disappointedness as an outstanding feature of a way of life.
Disappointedness is presented as a pathological organisation or character
disorder that expresses specific unconscious fantasies and gives rise to
disruptive transference-countertransference manifestations. The author singles
out disappointedness as a special problem rather than, in the usual way,
subsuming it under depressiveness or masochism and then assigning it a subsidiary
or merely descriptive role. With the help of a case example, he attempts to
illustrate the benefits of heightened clinical awareness of disappointment and
disappointedness. These benefits include increased access to the compromise
formations that can stand in the way of effective analytic work.
PMID- 10669962
TI - Male gender identity and sexual behaviour.
AB - One consequence of a heightened interest in intersubjectivity in the current
psychoanalytic literature has been a relative neglect of the examination of
unconscious fantasies. Presenting material from the analysis of three males, each
of whom, in childhood and/or adolescence, hid his penis between his legs and
looked at himself in a mirror naked, the author demonstrates the importance of
attending to both unconscious fantasies and their manifestations within the
interactive field of analysis. The first patient is a young child with a gender
identity disorder, whose wish to be like his mother was a response to the
emotional loss of her during early childhood. The second patient is an
adolescent, whose behaviour in front of a mirror was a manifestation of his
desire to possess his mother and be her, to humiliate and sadistically control
her, and at the same time, to experience the masochistic sexual gratification of
being a seemingly helpless victim. The third patient, a 48-year-old male, came to
analysis filled with suicidal impulses and self-hatred related to homosexual
impulses. His repeated examination of himself in a mirror, with penis hidden,
reflected severe castration anxiety, related to an ambivalent relationship with
an angry mother and a longing for attention from an unavailable father. The
article closes with a description of the similarities and differences in the
dynamics of these three males as well as a discussion of the meaning of similar
behaviour in other males seen in consultation.
PMID- 10669963
TI - Erotic complications.
AB - The author argues that erotic transference-countertransference dynamics present
particular complexities when they develop between gender constellations other
than male analyst and female patient. She addresses the dynamics of a complicated
erotic transference in concert with an aversive countertransference response as
it evolved between a female analyst and female patient. The intense erotic
transference that developed defied classification as either maternallerotic or
oedipallerotic, and instead included both features in a rapidly shifting process
that was difficult to address analytically. The analyst's confused, often
aversive, response to her patient's erotic wishes ultimately revealed a subtle re
enactment involving split-off and erotised experiences of emotional penetration
and scrutiny. When these issues were addressed, the erotic transference
dissolved, and the analyst's experience of her patient shifted rather
dramatically. It is suggested that complex erotic transference sometimes contains
within it evidence of previously repressed object experiences that were not
primarily sexual in nature.
PMID- 10669964
TI - Narcissistic resistances in the analytic experience.
AB - The narcissistic resistances in the clinical experience and the supposed autonomy
of the patient to reproduce the narcissistic stage are studied in this paper. The
problem is examined through the analysis of a patient, who masturbated
compulsively. The relationship between the symptom and the transference is
investigated because the symptom related to specific behaviour from the object,
and in order to understand the meaning of the phantasy that underlines the auto
erotic activity. It is pointed out that, in order for defensive activity to
fulfil its sense of narcissistic refuge, an other (distinct from the subject)
must carry out an essential function of support of the narcissistic defence.
Narcissistic self-sufficiency is governed by a paradox, as it needs an object to
demonstrate that it can subsequently dispense with this object. A second paradox
occurs when the narcissistic subject can only succeed in dispensing with the
object if the object gives some sign indicating that he is affected by such
'doing without'. In the analytical relationship, this type of defence manifests
itself as narcissistic resistance. The analyst participates in the covering-up of
the dependency that the defensive system has on the external object and this is a
prerequisite for establishing the resistance.
PMID- 10669965
TI - The impact of a war experience on the inner world of a young child.
AB - The author uses material from the treatment of a young child whose development
became seriously arrested from the time of a traumatic experience during a war.
This experience, combined with the impact of the birth of a younger sibling while
he was still a baby himself, had catastrophic consequences. He could only
communicate his feelings of terror and fear of dying through the use of
projective identification. The persecutory anxiety of this child was such that
for a while he could not tolerate hearing the interpretations, and was prone to
violent outbursts. The author describes how she had to bear the projections and
manage the physical attacks while trying to maintain the capacity to observe and
think clearly. This setting produced an experience of containment that gradually
allowed this child to accept and understand interpretations which diminished the
power of feelings that had overwhelmed him in the past. Through introjection of
the experience of being understood during his sessions, he began to develop the
capacity to think about his feelings. This allowed him to gradually recover,
develop, and make use of his intelligence and imagination, and the behavioural
difficulties that brought him to treatment disappeared.
PMID- 10669966
TI - 'My bad diagnostic error': once more about Freud and Emmy v. N. (Fanny Moser).
AB - The author examines two aspects of the case of Fanny Moser (Emmy von N. in the
'Studies on Hysteria'): first, a hitherto unknown letter written by Sigmund Freud
to Fanny Moser's daughter in 1935, in which he revises his diagnosis of half a
century before, describing it as 'a bad diagnostic error' and apologising to the
daughter; second, the dates of Fanny Moser's treatment. All previous attempts
have failed to date it consistently. The author combines all the information
about the case of Fanny Moser and the circumstances of Freud's life in that
period and shows that Freud took over the case in 1888, not in 1889. In addition,
he suggests that Emmy von N. has had a significant influence on Freud's papers on
'Hysteria' and on his comparative study 'Organic and hysterical motor paralyses'.
PMID- 10669967
TI - Some reflections on identification.
AB - The author presents a view of identification based on a rereading of two of
Freud's key texts and an approach derived from an academic interpretation of
Hegel dating from the 1930s. These aspects are considered at length. The
importance of the human and anthropogenic element is stressed. The human subject
is presented as coming into being through language; being called upon to be what
he is not and not to be what he is, the subject appears as wishful in nature,
desiring the wish of the other at the same time as he desires the object of the
other's wish. The author argues that identification as a problem arises only in a
human being who speaks or has received an injunction to speak; this raises the
question of who or what he is and of being as such. Analytic treatment may in his
view therefore proceed in one of two directions, one based on the interplay of
projection and introjection with identification as an end, and the other on
resistance and repression where the Oedipus complex is seen as the nuclear issue.
Identification is seen in terms of overcoming the negative identity of not being
all other subjects, and identity is found to be a conscious response that might
even have a political element.
PMID- 10669968
TI - Tender love and transference: unpublished letters of C. G. Jung and Sabina
Spielrein.
AB - The author dissents from the widely accepted interpretation that the relationship
between Sabina Spielrein and Carl Jung in the years 1904-1910 included sexual
intercourse and constituted an ethical breach of the doctor-patient boundary in
the course of a treatment. Spielrein declared that her treatment ended with her
discharge from the Burgholzli hospital as Jung's patient in 1904-1905. Jung
maintained he 'prolonged the relationship' in order to prevent a relapse and also
referred to it as a friendship. Materials published in 1994 (letters, drafts,
diaries, hospital chart) and unpublished letters recently found by the author in
the Claparede archive in Geneva shed new light on previously published documents
and interpretations by Carotenuto that have dominated the secondary literature
since 1980. The new materials provide a more nuanced view of the Spielrein-Jung
relationship and point to the function of non-erotic love in the therapeutic
relationship. A new look at the Freud-Jung correspondence about the Spielrein
Jung relationship shows that Jung's perception that a sex scandal was initiated
by Spielrein resulted from Jung's misreading of rumors concerning another woman;
the episode had no ill effect on the relationship between Freud and Jung.
PMID- 10669969
TI - Psychoanalysis and the neurosciences: a topical debate on dreams.
AB - The author begins by pointing out that, whereas Freud first turned his attention
to dreams in 1895, they became an object of neuroscientific interest only in the
1950s, after the discovery of rapid-eye-movement (REM) sleep and the observation
that a subject woken in an REM phase could remember and narrate them. He
discusses the various brain structures found by the neuroscientists to be
implicated in dreaming and the associated hypotheses about their involvement in
the processes of remembering dreams, their spatial construction and semantic
organisation, and the dreamer's emotional participation in and narration of
dreams. Attention is drawn to recent psychophysiological research findings
indicating that dreaming occurs in all sleep phases and not only in REM episodes.
The cognitivist contribution is also discussed. The author goes on to demonstrate
the difference between the neuroscientific and psychoanalytic approaches to
dreams. Whereas the neuroscientists are interested in the structures involved in
dream production and in dream organisation and narratability, psychoanalysis
concentrates on the meaning of dreams and on placing them in the context of the
analytic relationship in accordance with the affective history of the dreamer and
the transference. The brain structures and functions of interest to the
neurosciences, while constituting the physical and biological substrate of these
aspects, are stated to be irrelevant to their psychoanalytic understanding.
PMID- 10669970
TI - The importance of capacities in psychoanalysis and the language of human
development.
AB - The author explores the human capacity to contain or hold experience--for self
and other--by analysing the word capacity itself. Underlying the discussion is
the proposition that hidden in the word capacity is a particular perspective on
mental mechanisms fundamental to object-relations theory and that specific
consideration of the word may, therefore, add to an understanding of these
mechanisms. The author suggests that the term may have entered the language of
psychoanalysis 'by mistake'. He then looks at its meaning in terms of its
etymology, grammatical 'flavour', metaphorical significance and conceptual use,
in particular by Bion and Winnicott. It is argued that psychoanalysis is part of,
and makes a significant contribution to, a long tradition of learning from
experience, in which development is understood as the progressive emergence or
evolution of capacities. The underlying meaning of the word suggests that
development is expansive rather than linear, step-by-step or cyclical (unlike,
for example, stage, level, phase, position or loop). The author suggests that the
notion of capacities may provide a framework for applying insights from the
theory and practice of psychoanalysis in other organisational and societal
contexts.
PMID- 10669971
TI - Knowledge, consensus and uncertainty.
AB - Some months ago the editors of this journal asked me if I would undertake a
series of short entries of a general sort on philosophical topics germane to
current discussions in psychoanalysis. Both authors and topics were left to my
discretion. I thought the series was a good idea and gladly agreed to do it. To
my surprise and pleasure, all the philosophers I invited accepted I am only sorry
that the series could not be longer as there are other philosophers as well who
would have been splendid participants, and other topics I would like to have
addressed. The essays that will follow in subsequent issues represent by and
large the tradition of analytic philosophy, though this has come in the last few
decades to comprise many of the themes we used to associate with the Continental
tradition. Future entries, by James Conant, Donald Davison, Pascal Engel, Dagfinn
Follesdal, James Hopkins, Ernest Le Pore, Jeffrey Malpas, Jerome Neu, Brian
O'Shaughnessy, Richard Rorty and Richard Wollheim, will address the following
topics: intersubjectivity, meaning and language, consciousness and perception,
pragmatism, knowledge and belief, norms and nature, metaphor, hermeneutics,
truth, self-deception, the emotions. The essay below on knowledge, which will
also be the topic of another entry by a different author later on, is the only
one in the series that I will write.
PMID- 10669972
TI - 'Getting in on the act: the hysterical solution'.
PMID- 10669973
TI - 'The Piggle'.
PMID- 10669974
TI - A neurocorrective approach for MMPI-2 use with brain-damaged patients.
AB - Conventional administration of the Minnesota Multiphasic Personality Inventory-2
(MMPI-2) to aetiologically distinct brain-damaged out-patients (n = 137) revealed
significant indications of psychological maladjustment. An adjustment for the
endorsement of aetiology-specific items pertaining to traumatic brain injury
(TBI), stroke, and whiplash was considered necessary, however, because these
items may represent potentially valid symptoms or manifestations of neurological
damage or dysfunction. These so-called neurologically relevant items (NRIs) were
identified in a previous study. With this corrective approach, based on the
complete MMPI-2 item pool, it was shown that T-score elevations could at least in
part be attributed to symptoms associated with brain injury, regardless of the
type of brain damage. Similarly, after prorated correction for the endorsement of
NRIs, code-typing appeared to be substantially changed with respect to both
occurrence and content of the MMPI-2 defined code-types. The validity of the NRI
concept was supported by comparing NRI/non-NRI endorsement ratios of
traumatically brain-injured patients with those of non-neurological patients, and
with those having anxiety and somatoform disorders. To prevent unjustified
interpretations when administering the MMPI-2 to brain-damaged patients, an
adjustment procedure for NRI-endorsement is proposed, and difficulties in
interpretation are discussed.
PMID- 10669975
TI - Distribution of psychological aspects in subgroups of chronic low back pain
patients divided on the score of physical performance.
AB - This study investigates whether different subgroups of chronic low back pain
patients (CLBPs) differ in psychological aspects assessed with the Symptom
Checklist (SCL-90) and the Multidimensional Pain Questionnaire (MPI-DLV). Four
subgroups of CLBPs are discerned using the results of lumbar dynamometry: 1.
Patients with performances lower than healthy subjects (expected performance; n =
45). 2. Patients with performances comparable to healthy subjects (normal
performance; n = 18). 3. Patients with inconsistent test behaviour (submaximal
performance; n = 6). 4. Patients with performances that could be either maximal
or submaximal (gray-zone performance; n = 10). Significant differences in
psychological aspects were found between patients with submaximal and patients
with expected performances but not between patients with normal and patients with
expected performances. All patients with submaximal performance report a high
degree of psychological distress, in contrast to 30% of those with normal
performance and 20% of those with expected performance. Because of the
differences found in psychological aspects between the CLBP subgroups, it is
thought that a physical screening together with a psychological screening
provides better insight in the two aspects of the deconditioning syndrome and
thus can give better treatment indications than a physical screening alone.
PMID- 10669976
TI - A multidimensional longitudinal analysis of family coping with brain injury.
AB - Longitudinal research is needed to advance knowledge and practice in the area of
family coping with brain injury. The purpose of this investigation was to examine
the dimensions that underlie family coping with brain injury across a 2-year time
period (1995 to 1997). Two-dimensional configurations of 30 family coping
behaviours indicated a like family coping pattern of cognitive versus behavioural
coping (Dimension 1) in both 1995 and 1997. The data also showed that families
had a differing, or changed, family coping pattern along Dimension 2 from brain
injury-focused coping versus family-to-community fit in 1995 to seeking
professional help versus intra-family coping in 1997. Results thus indicated both
changes and consistent coping patterns within the same group of families across
time. Such information can be used to guide clinical family intervention, the
development of long-term family support services, and future brain injury family
research.
PMID- 10669977
TI - Risk factors for disability pension among unemployed women on long-term sick
leave.
AB - BACKGROUND: In 1996 some 520,000 people (13% of Sweden's working force) were
either long-term sick-listed or on disability pensions. To reintroduce sick and
injured people to the workforce, vocational rehabilitation has received
increasing emphasis. Unemployed women seem particularly difficult to
rehabilitate. One explanation could be that unemployed women have more complex
problems than others; another could concern the selection of cases for vocational
rehabilitation programmes. AIM: The primary aim of this study was to test the
hypothesis that unemployed women on sick-leave have more severe problems than
others. A second purpose was to investigate whether the manner of selection for
vocational rehabilitation programmes is different for unemployed women than for
others. MATERIAL AND METHOD: The study analysed 364 registered long-term sick
leave cases (90 days or more) initiated during 1992-1994 in the city of
Stockholm, Sweden. RESULT: Our hypothesis was supported by the study. Unemployed
women were exposed to more risk factors than unemployed men or employed men and
women. Regarding the selection of cases for rehabilitation, no difference was
present between unemployed women and others. A finding, however not statistically
significant, was that people in vocational rehabilitation, regardless of sex and
employment status, were less exposed to risk factors than people not undergoing
rehabilitation.
PMID- 10669978
TI - Collaborative partnerships in evaluation and experimental rehabilitation
research.
AB - Changes in rehabilitation and clinical practice, the recognition of the role of
clients in achieving rehabilitation goals, and client participation in decision
making and administration of service delivery have contributed to the development
of new methodologies for research and evaluation. In this paper, the traditional
relationship between researchers and subjects in traditional rehabilitation
evaluation and research is contrasted with relationships between researchers and
clients-consumers in newer methodologies. The limitations and challenges to these
models are discussed. Collaborative research, characterized by shared power and
non-hierarchical authority between client-consumers and researchers, is described
as an alternative model for experimental and evaluative research. Collaborative
relationships provide a structure for building upon the knowledge and expertise
of each research partner. The authors draw upon their own experience of
collaborative research partnerships and models of research partnerships are
described. Research developed and conducted in a collaborative partnership can
include quantitative and qualitative approaches, maintain traditional scientific
perspectives of objectivity, reliability and replicability, and improve
participation rates, continuity of involvement for longitudinal studies and
utilization of researched methods into practice.
PMID- 10669979
TI - Patients with metastatic breast cancer: their physical and psychological
rehabilitation needs.
AB - Few studies have monitored the physical and psychological sequelae of a diagnosis
and treatment of metastatic breast cancer and the findings of the present study
enables members of the rehabilitation team to understand the range of problems
patients encounter, refer patients to other rehabilitation, and plan appropriate
treatment. The present study aimed to describe the levels of anxiety and
depression; to describe their rehabilitation status; and to ascertain whether any
relationship exists between mood disturbance and physical rehabilitation status
in a sample of women with metastatic breast cancer. Eighty patients with staging
confirmed metastatic breast cancer were interviewed at home every eight weeks
from diagnosis of metastases, on eight occasions using the Cancer Rehabilitation
Evaluation System--Short Form, the Hospital Anxiety and Depression Scale, and an
interview schedule to ascertain demographic and disease details. Results
suggested that patients had a range of rehabilitation needs throughout the course
of their disease. Mood disturbance was a significant problem in this sample of
patients with many patients scoring in the case range for anxiety and depression
on the HAD. A positive and strong relationship was found to exist between mood
disturbance and physical rehabilitation status. The results of the study are
discussed in the context of previous research and future research and clinical
implications for the rehabilitation team are discussed.
PMID- 10669980
TI - Psycho-social dysfunctions in patients after recovery from mania and depression.
AB - Contrary to popular opinion, complete functional recovery does not occur in
approximately 25% of patients with a diagnosis of mood disorders. The current
study aimed at finding the recovery status in major mood disorders. A sample
group of 122 patients (77 bipolar and 45 major depression) was selected from the
outpatient department, fulfilling the DSM-IV diagnostic criteria. All patients
had their index episodes at least one year prior to their date of inclusion and
were either asymptomatic or mildly symptomatic during that time. Manics and
depressives were rated with the Bech Raefelson Mania Scale (BRMS) and Hamilton
Depression Rating Scale (HDRS) respectively. All the patients were also rated on
the Brief Psychiatric Rating Scale (BPRS), Dysfunction Analysis Questionnaire
(DAQ) and Global Evaluation Scale of Disability Assessment Schedule by WHO
(GES/DAS). They were compared with 40 age and sex matched normal controls. It was
found that the symptomatic recovery was better than the functional recovery in
both manics and depressives and patients with major depression were marginally
more dysfunctional compared to those with mania. It is concluded that a majority
of patients of both mania and depression do not achieve complete functional
recovery and are in need of on-going psychosocial rehabilitation.
PMID- 10669981
TI - A survey of rehabilitative services and people coping with physical disabilities
in Uganda, East Africa.
AB - The impact of physical disability in the developing world is a tremendous health
issue. The developing world presents many challenges in the lives of these
people, many who cope without rehabilitative care. To determine how disabled
people manage in this setting, 49 mobility-impaired Ugandans were interviewed.
Functional capacity was assessed by determining the severity of lower extremity
impairment and identifying the use of assistive devices and personal assistance
needed in activities of daily living. Males appeared to have greater access to
rehabilitative equipment, namely wheelchairs, and to personal assistance. The use
of assistive devices was indicative of greater mobility, which subsequently
provided greater opportunities, such as formal education or employment. Subjects
with severe impairments without access to rehabilitative equipment were dependent
upon crawling for mobility and begged for economic survival. Although there were
a mix of responses towards perceived attitudes towards disabled subjects, more
reported being viewed in a positive than in a negative light. Findings suggest
that gender-related issues may limit access to rehabilitative equipment, due to
limited financial resources of women living in the developing world. Uganda
utilizes a viable political organization of people with disabilities to raise
awareness and to empower its citizens coping with disability.
PMID- 10669982
TI - Discharge to home among Hispanic and non-Hispanic stroke survivors: does family
make a difference?
PMID- 10669983
TI - Aberrant behaviour of persons with developmental disabilities as a function of
the characteristics of training tasks.
PMID- 10669985
TI - Social support in different communication environments.
PMID- 10669984
TI - Outcome of obturator nerve block with alcohol for the treatment of hip adductor
spasticity.
PMID- 10669986
TI - Rehabilitation needs as a result of firearm-related injury; a four-year
retrospective study from an inner-city hospital in the United States.
PMID- 10669987
TI - Educational and behavioural characteristics of autistic children in the United
Arab Emirates.
PMID- 10669988
TI - Previous endoscopic treatment does not affect complication rate and outcome of
laparoscopic Heller myotomy and anterior fundoplication for oesophageal
achalasia.
AB - BACKGROUND: Anedoctal reports suggest a detrimental effect of pneumatic dilation
and botulinum toxin injection in patients who are potential candidates for Heller
myotomy. AIMS: To assess symptomatic and objective outcome in patients undergoing
Heller myotomy as a primary procedure or after failed endoscopic treatment.
PATIENTS: Between November 1992 and December 1998, 92 patients with oesophageal
achalasia were treated. Sixty patients had primary surgery; 32 patients had
surgery after unsuccessful pneumatic dilation (n = 22), or botulinum toxin
injection (n = 10). METHODS: Laparoscopic Heller myotomy plus Dor fundoplication
with routine intraoperative endoscopy. Operative records, symptoms, and results
of radiological, manometric and scintigraphic assessment in the two groups of
patients were compared. RESULTS: The mean operative time, the rate of
intraoperative mucosal tears and the incidence of postoperative dysphagia were
similar in the two groups. Mucosal tears occurred more frequently during the
first 30 operations (p < 0.05). Median follow-up was 28 months (range 4-76). An
abnormal oesophageal acid exposure was documented in 2 patients in the primary
surgery group (7.7%), and in 2 patients in the pneumatic dilation/botulinum toxin
group (13.3%) (p = ns). Lower oesophageal sphincter pressure significantly
decreased in both groups (p < 0.01). The mean percentage of radionuclide residual
activity in the oesophagus at 1 and 10 minutes significantly decreased in both
groups (p < 0.01). CONCLUSIONS: There was only a trend, although not
statistically significant, towards an increased risk of complications and adverse
effects in patients previously treated by pneumatic dilation or botulinum toxin.
The higher incidence of mucosal tears during the first 30 operations suggests the
effect of the learning curve.
PMID- 10669989
TI - Helicobacter pylori eradication with dual and low-dose triple therapy in patients
with liver cirrhosis.
AB - BACKGROUND AND AIMS: Few data exist on the treatment of Helicobacter pylori
infection in cirrhotic patients. In this study we assessed the efficacy of
standard dual and one-week low-dose triple therapy on Helicobacter pylori
eradication in cirrhotics. PATIENTS AND METHODS: In a prospective study, 83
cirrhotic patients with epigastric pain were randomised to receive either a two
week course of dual therapy, composed of omeprazole 20 mg b.d. plus amoxycillin 1
g b.d. (n = 41) or a one-week course of triple therapy, composed of omeprazole 20
mg b.d., clarithromycin 250 mg b.d., and tetracycline 500 mg b.d (n = 42).
Helicobacter pylori infection at entry and eradication 6-8 weeks after the end of
therapy were assessed by rapid urease test and histology on biopsies from the
antrum and corpus. When eradication did not occur with either dual or triple
therapy, patients were given the alternative regimen. Helicobacter pylori
eradication in these patients was assessed 6-8 weeks after the end of treatment
by a further endoscopy. RESULTS: Helicobacter pylori eradication was achieved in
87.8% (36 out of 41; 95% confidence interval 77.8-97.8%) of patients after dual
therapy and in 85.7% (36 out of 42; 95% confidence interval 75.1-96.3%) of
patients treated with triple therapy (p = NS). In patients in whom initial
eradication was unsuccessful, re-treatment eradicated Helicobacter pylori in 4
out of 5 patients given the triple regimen and in all 5 patients who received the
dual therapy. One patient was lost to follow-up. No major side-effects were
reported for either treatment regimen. CONCLUSIONS: Our data show that both dual
and triple therapies are effective in Helicobacter pylori eradication in
cirrhotics as well as in eradication failure patients. Therefore, the use of the
dual therapy regimen is strongly suggested as an initial treatment for
Helicobacter pylori eradication in cirrhotic patients.
PMID- 10669990
TI - Differential features of gastric cancer patients, either Helicobacter pylori
positive or Helicobacter pylori negative.
AB - BACKGROUND: Helicobacter pylori infection is associated with an increased risk of
gastric cancer. In Helicobacter pylori negative patients, factors different from
those in Helicobacter pylori positive patients may be involved in gastric
carcinogenesis. METHODS: Thirty-nine recently diagnosed consecutive patients with
gastric cancer were investigated. Gastric biopsies were obtained for detection of
Helicobacter pylori (by immunohistochemistry), non-Helicobacter pylori flora (by
modified Giemsa and culture) and histological assessment according to the Sydney
classification by Haematoxylin-Eosin staining. In serum samples, Helicobacter
pylori antibodies were determined by IgG enzyme-linked immunosorbent assay, IgA
enzyme-linked immunosorbent assay, and Western blotting. Furthermore, serum
gastrin, pepsinogen A and C and plasma chromogranin A were determined. RESULTS:
Helicobacter pylori was detected by immunohistochemistry in 53.8%, by IgG in
56.4%, by IgA in 33.3%, and by Western blotting in 74.4% of the 39 patients. Ten
patients (25.6%) were negative by both histology and serology. Non-Helicobacter
pylori flora was detected in 27 of the 39 patients (69.2%) with a similar
frequency in Helicobacter pylori positive and negative patients. Helicobacter
pylori positivity was found significantly more often in diffuse than intestinal
type carcinoma patients (p < 0.05). Elevated gastrin levels and antrum-sparing
atrophic gastritis were more frequent in Helicobacter pylori negative than in
Helicobacter pylori positive patients (p < 0.05). CONCLUSIONS: In 10 out of 39
gastric cancer patients, no evidence of previous or current Helicobacter pylori
infection could be demonstrated. Non-Helicobacter pylori was found in 69.2% of
patients regardless of the Helicobacter pylori status. Further studies are needed
to establish the contribution of non-Helicobacter pylori flora as well as antrum
sparing atrophic gastritis with hypergastrinaemia to the development of gastric
cancer.
PMID- 10669991
TI - Is autoimmunity involved in the relationship between Helicobacter pylori
infection, atrophic gastritis and gastric cancer?
PMID- 10669992
TI - Macroamylase detection in serum using selective precipitation: a rapid and
reliable assay.
AB - BACKGROUND AND AIM: Available assays for measurement of pancreatic isoamylase in
serum based on specific immunoinhibition of salivary fraction are unable to
detect macroamylase. We combined a polyethylene glycol test which identifies
macroamylase by selective precipitation with an automated assay for total amylase
and pancreatic isoamylase measurement. METHODS: We analysed 24 sera proven
positive for macroamylase using gel filtration chromatography and 80 negative
sera. Precipitation of macroamylase with polyethylene glycol, colourimetric
measurement of total amylase activity and immunoinhibition for the determination
of pancreatic isoamylase were carried out. RESULTS: Macroamylasaemic sera showed
precipitation of at least 71% of the amylase activity, while sera with normal
sized amylase exhibited a maximum of 61%. In all the macroamylasaemic sera but
two, the immunoinhibition test showed a rise in pancreatic isoamylase, which was
found to be the prevalent fraction in 16. In 21 out of 24 sera with macroamylase
and 67 out of 80 with normal-sized amylase, the precipitated amylase activity was
also measured after immunoinhibition of non pancreatic activity. In
macroamylasaemic sera, the percentage of precipitated pancreatic isoamylase
activity ranged from 75% to 98%, while in samples with normal-sized amylase it
was less than 71%. CONCLUSIONS: Polyethylene glycol precipitation can easily be
combined with automated assays for the determination of pancreatic isoamylase and
should be carried out whenever dealing with hyperamylasaemia of unclear origin.
PMID- 10669993
TI - Clinical features and genotype-phenotype correlations in 41 Italian families with
adenomatosis coli.
AB - BACKGROUND: Familial Adenomatous Polyposis in an autosomal dominant disease in
which the large bowel is carpeted by polyps of various dimensions appearing
during the second or third decade of life. Several extracolonic manifestations
complete the clinical spectrum of Familial Adenomatous Polyposis. If untreated,
the disease leads invariably to colorectal cancer. The gene responsible for the
disease, adenomatous Polyposis Coli, has been localized at chromosome 5q21. AIMS:
To describe the clinical features of 156 Familial Adenomatous Polyposis patients
(from 41 families) and to analyze possible correlations between genotype and
phenotype. PATIENTS AND METHODS: Familial Adenomatous Polyposis was defined as
the presence of 100 or more polyps in the large bowel. In 17 families (41%), the
proband was the only affected individual (single cases). Adenomatous Polyposis
Coli gene mutations were studied on DNA extracted from peripheral white blood
cells and evaluated by polymerase chain reaction single strand conformation
polymorphism, followed by direct sequencing of samples showing abnormal banding
at single strand conformation polymorphism. RESULTS: The large majority of
Familial Adenomatous Polyposis patients underwent surgery; colectomy with
ileorectal anastomosis was the most frequent approach, however, cancer of the
rectal stump developed in 11.6% of patients submitted to colectomy and ileorectal
anastomosis. Adenomas were rare in the stomach (8.8%), but their frequency
increased in the duodenum (33.8%) and jejunum (55.0%, chi 2 for trend 23.7, p <
0.001). Desmoid tumours were diagnosed in 17 patients (10.9% of the total) and in
6 families. Mutations of the Adenomatous Polyposis Coli gene were studied in 20
out of 25 families (80%) and on a total of 75 individuals. The most frequent
alterations were 1 to 5 bp deletions leading to stop codons and truncated
proteins. Desmoid tumours, presence of duodenal or jejunal adenomas were
associated with an ample range of mutations, from codon 215 to codon 1464. In
contrast, particularly severe polyposis (mean age at appearance of polyps 11-16
years, and of cancer development 27-32 years) was associated with a "hotspot"
mutation site at codons 1303-1309. CONCLUSIONS: In patients with Familial
Adenomatous Polyposis, subtotal colectomy with ileorectal anastomosis is still
the treatment of choice. Adenomatous lesions seem to show a "gradient"
distribution from the stomach to the large bowel. Desmoid tumours are relatively
common, though their incidence is limited to some of the families. Constitutional
mutations can be detected in 80% of the investigated families. Genotype-phenotype
correlations showed a hot-spot at codons 1303-1309, frequently associated with
severe polyposis.
PMID- 10669994
TI - Circulating pro- and antioxidant factors in iron and porphyrin metabolism
disorders.
AB - BACKGROUND: Porphyria cutanea tarda and haemochromatosis are taken to be
spontaneous human models of oxidative cellular damage, with an increased risk of
fibrosis and cancer evolution. AIM: To define the relative pro-oxidant roles of
porphyrin and iron, in their different molecular forms, and their effects on
antioxidant biological systems. PATIENTS: A group of 17 patients with porphyria
cutanea tarda and a group of 14 patients with primary and secondary
haemochromatosis, were compared with 21 healthy controls. METHODS: Plasma
retinol, tocopherol, alpha- and beta-carotene, ascorbic acid, glutathione,
malonyldialdehyde and red blood cell free iron were determined using high
performance liquid chromatography. RESULTS: Only a modest increase in iron stores
was demonstrated in the porphyria cutanea tarda group; in the haemochromatosis
patients ferritin levels were almost seven times higher. By contrast, there was a
sharp and virtually identical increase in red blood cell free iron and
malonyldialdehyde in both the patient groups. A significant reduction was
observed in retinol, alpha-, beta-carotene and red blood cell glutathione levels
being more marked in porphyria cutanea tarda than in haemochromatosis patients.
CONCLUSIONS: The study confirms the strong pro-oxidant effects of porphyrins in
vivo, through an induction of the free toxic iron form, even though the total
iron pool is not greatly expanded. The additional free-iron and porphyrin oxidant
effects are documented both in red blood cell and plasma in the porphyria cutanea
tarda group. It confirmed that aging exerts a negative influence in terms of pro-
and antioxidant balance in all cases, but particularly in the haemochromatosis
group.
PMID- 10669995
TI - Small bowel schwannoma with diffuse subcutaneous lipomatosis. Case report and
literature review.
AB - A case of a small-bowel schwannoma with diffuse familiar lipomatosis is
described. This case underlines the rarity of the neoplasm and its probably
chance association with subcutaneous lipomatosis. The intestinal neoplasm was
diagnosed preoperatively by upper gastrointestinal endoscopy and a small-bowel
enema; computed tomography scan confirmed the intestinal lesion. Attention is
focused on the morphological features of intestinal schwannomas and their
biological behaviour.
PMID- 10669996
TI - Ischaemic necrotizing pancreatitis after cardiac surgery. A case report and
review of the literature.
AB - Ischaemia is a rare but often lethal aetiology of pancreatitis. A 67-year-old man
underwent aortocoronary by-pass. Postoperatively, he developed atrial
fibrillation and possibly acute myocardial infarction. Later, he had acute
pancreatitis and underwent laparotomy for purulent peritonitis due to a ruptured
pancreatic abscess. Cholesterolosis was found but no gallstones. The
postoperative period was heavily complicated and the patient eventually died due
to multiorgan failure. The occurrence of ischaemic pancreatitis should be more
readily suspected in patients with abdominal symptoms following surgery that
induces ischaemia of the pancreas. It is possible that delay in diagnosis
accounts for the high death rate of such postoperative complication.
PMID- 10669997
TI - Electrohydraulic lithotripsy treatment of gallstone after disimpaction of the
stone from the duodenal bulb (Bouveret's syndrome).
AB - A 75-year-old man with right upper quadrant abdominal pain was diagnosed by
gastroscopy to have an impacted gallstone in the duodenal bulb. Using the
polypectomy loop, the stone was extracted from the bulbus and mobilized into the
stomach. After failure to remove the stone from the stomach as well as
fragmentation by mechanical lithotripsy, electrohydraulic lithotripsy was used to
break up the stone, parts of which passed spontaneously through the bowel. Thus,
it was unnecessary to proceed with surgical enterolithotomy to remove, from the
duodenal bulb, the impacted gallstone responsible for the gastric outlet
obstruction.
PMID- 10669998
TI - Current role of magnetic resonance cholangiopancreatography in the diagnosis of
common bile duct and pancreatic diseases.
AB - Magnetic resonance cholangiopancreatography is a noninvasive procedure that is
increasingly used in patients with hepatobiliary and pancreatic diseases. The
accuracy of magnetic resonance cholangiopancreatography has dramatically improved
during the last few years, and there is no doubt that magnetic resonance
cholangiopancreatography will have a major impact on the gastroenterologist's
diagnostic work-up of patients. The key for success in dealing with hepatobiliary
and pancreatic diseases is the precise knowledge of their course, the indications
for treatment, and the therapy available. Thus, a team approach with strong
representation from gastroenterology and radiology will be the most optimal path
to an improved understanding of the value of Magnetic Resonance technology.
PMID- 10670000
TI - Evolving concepts on inflammatory bowel disease. Are we happy with the present
nosology?
AB - The term inflammatory bowel disease traditionally comprises ulcerative colitis,
Crohn's disease and indeterminate colitis, an intermediate variant of the two
major forms. The term is commonly used in the literature and in clinical practice
even though it has never been revised in a Consensus Conference. The present
nosology of inflammatory bowel disease seems not to be entirely satisfactory as
it is limited to chronic diseases only and does not include several recently
described idiopathic inflammatory bowel disorders. Although the aetiology of
inflammatory bowel disease remains unknown, both ulcerative colitis and Crohn's
disease are characterized by a similar pathogenesis which consists in a
persistent intestinal inflammation resulting from disregulation of the gut
mucosal immune system. The pathogenetic mechanisms could, therefore, provide a
suitable criterion for the classification of idiopathic inflammatory bowel
disease. A revised classification of inflammatory bowel disease is thus proposed.
It seems reasonable to subclassify inflammatory bowel disease into acute and
chronic forms. Acute forms should include the sudden attacks of ulcerative
colitis and Crohn's disease with rapid and complete resolution and the so-called
"acute self-limited colitis". The chronic forms should comprise, besides the
classical forms of ulcerative colitis, Crohn's disease and indeterminate colitis,
also other idiopathic inflammatory bowel conditions such as collagenous colitis,
lymphocytic colitis and eosinophilic gastroenteritis.
PMID- 10669999
TI - Echinococcal liver cysts: treatment with echo-guided percutaneous puncture PAIR
for echinococcal liver cysts.
AB - In spite of recent progress, treatment for liver echinococcal cysts is still far
from satisfying. In recent years, percutaneous drainage has been increasingly
used for this purpose and it has been shown to be an effective alternative to
surgery and chemotherapy alone. This technique is known as PAIR, from Puncture,
Aspiration, Injection (of a scolecidal agent), Reaspiration: here we present our
experience and the state of the art of PAIR. Patients from Italy and Turkana
(Kenya), harbouring 233 Gharbi type I, II and III echinococcal cysts were
successfully treated with PAIR: it was performed according to protocols
established at the Division of Infectious and Tropical Diseases, IRCCS-
Policlinico S. Matteo, University of Pavia. In Italy, one relapse was recorded,
four years after the procedure; the patient was treated again with PAIR; no cases
of anaphylactic shock or peritoneal dissemination were observed in a follow-up of
10 years; only 10 minor complications (biliary fistula, urticarioid reaction,
abscessualization of the cyst, anaphylactoid reactions) were reported. Long-term
results indicate that in Gharbi type I, II and III echinococcal cysts, and in
developing countries, in particular, PAIR is a first choice method for the
treatment of abdominal localizations of this disease.
PMID- 10670001
TI - Renovascular impedance after total paracentesis.
PMID- 10670002
TI - Conservative non-surgical management of congenital oesophageal stenosis
associated with oesophageal atresia.
PMID- 10670003
TI - AIDS care nursing: looking forward, thinking back.
PMID- 10670004
TI - An investigation of the relationship between vitamin B12 deficiency and HIV
infection.
AB - The symptoms of vitamin B12 deficiency and several symptoms common to HIV
infection overlap. Additionally, persons with HIV infection have frequently been
found to have vitamin B12 deficiency. Therefore, the issue of concern is the
prevalence of B12 deficiency in HIV-infected persons. A retrospective study of 63
medical records in a midwestern urban veterans affairs medical center provided
the data for this study. Data were collected and analyzed for relationships among
B12 levels, certain hematologic components, medications, symptomatology, and
immune status. A chi-square goodness-of-fit test demonstrated a significant
prevalence of B12 deficiency among persons with HIV disease, and chi-square two
way tables demonstrated significant relationships between B12 deficiency and
weight loss and diarrhea. Prevalence of B12 deficiency in persons with HIV
infection has been shown to be significant, indicating that B12 deficiency
screening in persons with HIV infection may need be done to aid the health care
provider in planning the best possible care. Further research is needed to
corroborate these findings.
PMID- 10670005
TI - The Client Adherence Profiling-Intervention Tailoring (CAP-IT) intervention for
enhancing adherence to HIV/AIDS medications: a pilot study.
AB - This article describes the Client Adherence Profiling-Intervention Tailoring (CAP
IT) intervention designed to enhance adherence to HIV/AIDS medications and
reports the results of a pilot study aimed at assessing the feasibility of CAP
IT. Initially, CAP-IT was designed to be implemented by nurse case managers
during regularly scheduled home visits; it is currently under revision for use in
an outpatient, ambulatory care setting. CAP-IT is an innovative, structured
nursing assessment and care-planning activity that allows a standardized
assessment of client needs and tailored highly active antiretroviral therapy
adherence intervention strategies. CAP-IT is significantly different from the
current standard nursing case management practice. Pilot study results in a
sample of 10 home care patients suggests that clients have knowledge and skill
deficits related to adherence and in the management of the side effects of
medications. In addition, the pilot study supported the acceptability of the
protocol to clients and the feasibility of integrating CAP-IT into nurse case
manager practice. The pilot study results also provided evidence for the efficacy
of CAP-IT. The next steps include testing CAP-IT in a randomized clinical trial
to determine its effectiveness.
PMID- 10670006
TI - A team approach to the treatment of AIDS wasting.
AB - Despite the aggressive use of antiretroviral agents, AIDS wasting (AW) affects
many persons infected with HIV. AW is characterized by a disproportionate loss of
metabolically active tissue, specifically body cell mass--tissue involved with
glucose oxidation, protein synthesis, and immune system function. AW correlates
with poor quality of life and clinical outcomes. This condition requires a
multidisciplinary team approach for effective management. Optimal maintenance of
lean body mass and reversal of AW involves a combination of appropriate
antiretroviral use, opportunistic infection prophylaxis, optimal nutrition,
exercise, body composition monitoring, anabolic agents including growth hormone
(rhGH[m]) and testosterone supplementation, mental health support, economic aid,
and legal assistance. The team approach to treatment of AW requires the
coordinated activity of nurses, dietitians, physicians, pharmacists, social
workers, case managers, reimbursement personnel, caregiver(s), physical
therapists, and the patient. This article, based on clinical experience treating
AW, explains how the condition is managed using a multidisciplinary team
approach.
PMID- 10670007
TI - The utility of the Transtheoretical Model of behavior change for HIV risk
reduction in injection drug users.
AB - The spread of HIV among injection drug users (IDUs) is the second most common
mode of transmission next to sexual contact. Although HIV infections can be
prevented by changing high-risk behaviors such as needle sharing, these high-risk
behaviors are highly complex. Initially developed for smoking cessation,
Prochaska's Transtheoretical Model (TTM) is well-suited to the IDU population
because it recognizes that chronic behavior patterns are usually under some
combination of biological, social, and self-control. The objective of this
article is to examine the utility of the TTM for promoting risk reduction
behaviors among IDUs. This article will outline (a) the challenges of applying
the TTM to IDU behaviors with respect to HIV prevention, (b) the four major
components of the TTM as they relate to IDUs, (c) how risk reduction
practitioners are currently using the TTM, and (d) current and future research
using the TTM.
PMID- 10670008
TI - The Transtheoretical Model and stress management practices in women at risk for,
or infected with, HIV.
AB - Although scientific inquiry using the Transtheoretical Model of Behavior (TTM)
supports various behavior changes in multiple samples, no research was found that
examined this model with women already infected with HIV. This article provides a
brief overview of the related literature and describes a pilot study that
evaluated TTM concepts in women at risk for, or infected with, HIV. The pilot
study examined preliminary psychometrics of the research measures in women at
risk for (n = 9), or infected with, HIV (n = 10), and examined predicted
differences in situational confidence and stress management practices by HIV
serostatus (positive vs. negative) and stage of change (precontemplation and
contemplation vs. preparation, action, and maintenance) implied by the TTM. This
pilot study supports use of the TTM to examine readiness to use stress management
behavior in women regardless of their HIV serostatus. Further TTM stress
management inquiry is encouraged to extend the knowledge base needed in caring
for this vulnerable population.
PMID- 10670009
TI - Immune reconstitution in the HAART era, Part 1: Immune abnormalities in HIV/AIDS.
AB - Highly active antiretroviral therapy (HAART) has dramatically altered the course
of HIV infection. HAART has been associated with a substantial decrease in HIV
related morbidity and mortality and an improved quality of life for many persons
living with HIV/AIDS. This improvement is due to suppression of viral replication
and subsequent repletion of CD4+ T lymphocytes. However, it is not known if HAART
can restore the deficits in immune function that are induced by HIV infection,
such as anergy and disturbances in cellular phenotypes. In this first part of a
two-part series, the immune abnormalities associated with HIV infection will be
reviewed, and the concept of immune reconstitution will be introduced. In Part 2,
the clinical significance of immune reconstitution will be discussed.
PMID- 10670010
TI - Nevirapine prevents vertical HIV-1 transmission.
PMID- 10670011
TI - Developing your idea for a research project.
PMID- 10670012
TI - Program offers recognition of extraordinary partnerships in HIV care.
PMID- 10670013
TI - Puncture-resistant gloves introduced.
PMID- 10670014
TI - Life: past, present and future.
AB - Molecular methods of taxonomy and phylogeny have changed the way in which life on
earth is viewed; they have allowed us to transition from a eukaryote-centric
(five-kingdoms) view of the planet to one that is peculiarly prokarote-centric,
containing three kingdoms, two of which are prokaryotic unicells. These
prokaryotes are distinguished from their eukaryotic counterparts by their
toughness, tenacity and metabolic diversity. Realization of these features has,
in many ways, changed the way we feel about life on earth, about the nature of
life past and about the possibility of finding life elsewhere. In essence, the
limits of life on this planet have expanded to such a degree that our thoughts of
both past and future life have been altered. The abilities of prokaryotes to
withstand many extreme conditions has led to the term extremophiles, used to
describe the organisms that thrive under conditions thought just a few years ago,
to be inconsistent with life. Perhaps the most extensive adaptation to extreme
conditions, however, is represented by the ability of many bacteria to survive
nutrient conditions not compatible with eukaryotic life. Prokaryotes have evolved
to use nearly every redox couple that is in abundance on earth, filling the
metabolic niches left behind by the oxygen-using, carbon-eating eukaryotes. This
metabolic plasticity leads to a common feature in physically stratified
environments of layered microbial communities, chemical indicators of the
metabolic diversity of the prokaryotes. Such 'metabolic extremophily' forms a
backdrop by which we can view the energy flow of life on this planet, think about
what the evolutionary past of the planet might have been, and plan ways to look
for life elsewhere, using the knowledge of energy flow on earth.
PMID- 10670015
TI - Unanswered questions in ecology.
AB - This is very much a personal view of what I think are some of the most important
unanswered questions in ecology. That is, these are the questions that I expect
will be high on the research agenda over the coming century. The list is
organized hierarchically, beginning with questions at the level of individual
populations, and progressing through interacting populations to entire
communities or ecosystems. I will try to guess both at possible advances in basic
knowledge and at potential applications. The only thing that is certain about
this view of the future is that much of it will surely turn out to be wrong, and
many of the most interesting future developments will be quite unforeseen.
PMID- 10670016
TI - Theoretical biology in the third millennium.
AB - During the 20th century our understanding of genetics and the processes of gene
expression have undergone revolutionary change. Improved technology has
identified the components of the living cell, and knowledge of the genetic code
allows us to visualize the pathway from genotype to phenotype. We can now
sequence entire genes, and improved cloning techniques enable us to transfer
genes between organisms, giving a better understanding of their function. Due to
the improved power of analytical tools databases of sequence information are
growing at an exponential rate. Soon complete sequences of genomes and the three
dimensional structure of all proteins may be known. The question we face in the
new millennium is how to apply this data in a meaningful way. Since the genes
carry the specification of an organism, and because they also record evolutionary
changes, we need to design a theoretical framework that can take account of the
flow of information through biological systems.
PMID- 10670017
TI - Developmental biology and the redirection or replacement of cells.
AB - The aim of developmental biology is to understand how an egg converts itself into
a complete organism through the processes of cell differentiation, morphogenesis
and size regulation. The principles that have emerged over recent decades include
the constancy of the genome in nearly all cells of an individual, the existence
of stem cells in many organs and the overwhelming importance of signalling
between cells for the determination of their fate. These and other
characteristics of development are discussed here in relation to the prospect of
achieving cell and tissue correction or replacement with the help of nuclear
transplantation and signalling factors. Nuclear transplantation offers a one-step
procedure for generating multipotent embryo cells from the cells of an adult
tissue such as skin. It should be possible to proliferate the resulting cells as
can be done for mouse embryonic stem cells. Embryo cells can be made to
differentiate in many directions by exposing them to various agents or to
different concentrations of a single factor such as the transforming growth
factor beta class signalling molecule activin. The possibility of a cancerous
condition being acquired during these experimental manipulations can be guarded
against by transfecting cells with a conditional suicide gene. Thus it may be
possible to generate replacement cells or tissues from an adult human for
transplantation back to the original donor, without the disadvantage of any
genetic incompatibility.
PMID- 10670018
TI - Structural biology.
AB - Protein crystallography has become a major technique for understanding cellular
processes. This has come about through great advances in the technology of data
collection and interpretation, particularly the use of synchrotron radiation. The
ability to express eukaryotic genes in Escherichia coli is also important.
Analysis of known structures shows that all proteins are built from about 1000
primeval folds. The collection of all primeval folds provides a basis for
predicting structure from sequence. At present about 450 are known. Of the
presently sequenced genomes only a fraction can be related to known proteins on
the basis of sequence alone. Attempts are being made to determine all (or as many
as possible) of the structures from some bacterial genomes in the expectation
that structure will point to function more reliably than does sequence. Membrane
proteins present a special problem. The next 20 years may see the experimental
determination of another 40,000 protein structures. This will make considerable
demands on synchrotron sources and will require many more biochemists than are
currently available. The availability of massive structure databases will alter
the way biochemistry is done.
PMID- 10670019
TI - Drugs for a new millennium.
AB - A millennium, a century, even a decade is a long time-frame for speculation about
anything. Advances in biomedical research in the last few decades have been so
extraordinary and escalating at an ever-accelerating pace that any prophecy is a
risky proposition. However, it is possible to divine the big, unanswered
questions and envisage ways in which they might reasonably be approached in the
next few decades, a task which I will try to essay. So many drugs treat so many
different medical conditions that a detailed and comprehensive coverage would
probably be tiresome. Instead, I will address certain broad themes and diseases
that offer both immense challenges and great potential for advances. Rather than
review detailed experimental issues, I will confine myself to the 'big picture'
issues, providing examples of specific research only in a few instances drawing
largely from areas I know best.
PMID- 10670020
TI - From genotype to phenotype: genetics and medical practice in the new millennium.
AB - The completion of the human genome project will provide a vast amount of
information about human genetic diversity. One of the major challenges for the
medical sciences will be to relate genotype to phenotype. Over recent years
considerable progress has been made in relating the molecular pathology of
monogenic diseases to the associated clinical phenotypes. Studies of the
inherited disorders of haemoglobin, notably the thalassaemias, have shown how
even in these, the simplest of monogenic diseases, there is remarkable complexity
with respect to their phenotypic expression. Although studies of other monogenic
diseases are less far advanced, it is clear that the same level of complexity
will exist. This information provides some indication of the difficulties that
will be met when trying to define the genes that are involved in common
multigenic disorders and, in particular, in trying to relate disease phenotypes
to the complex interactions between many genes and multiple environmental
factors.
PMID- 10670021
TI - Levels and loops: the future of artificial intelligence and neuroscience.
AB - In discussing artificial intelligence and neuroscience, I will focus on two
themes. The first is the universality of cycles (or loops): sets of variables
that affect each other in such a way that any feed-forward account of causality
and control, while informative, is misleading. The second theme is based around
the observation that a computer is an intrinsically dualistic entity, with its
physical set-up designed so as not to interfere with its logical set-up, which
executes the computation. The brain is different. When analysed empirically at
several different levels (cellular, molecular), it appears that there is no
satisfactory way to separate a physical brain model (or algorithm, or
representation), from a physical implementational substrate. When program and
implementation are inseparable and thus interfere with each other, a dualistic
point-of-view is impossible. Forced by empiricism into a monistic perspective,
the brain-mind appears as neither embodied by or embedded in physical reality,
but rather as identical to physical reality. This perspective has implications
for the future of science and society. I will approach these from a negative
point-of-view, by critiquing some of our millennial culture's popular projected
futures.
PMID- 10670022
TI - The impact of molecular biology on neuroscience.
AB - How our brains work is one of the major unsolved problems of biology. This paper
describes some of the techniques of molecular biology that are already being used
to study the brains of animals. Mainly as a result of the human genome project
many new techniques will soon become available which could decisively influence
the progress of neuroscience. I suggest that neuroscientists should tell
molecular biologists what their difficulties are, in the hope that this will
stimulate the production of useful new biological tools.
PMID- 10670024
TI - Splendours and miseries of the brain.
AB - In this speculative essay, I examine two evolutionary developments underlying the
enormous success of the human brain: its capacity to acquire knowledge and its
variability across individuals. A feature of an efficient knowledge-acquiring
system is, I believe, its capacity to abstract and to formulate ideals. Both
attributes carry with them a clash between experience of the particular and what
the brain has developed from experience of the many. Both therefore can lead to
much disappointment in our daily lives. This disappointment is heightened by the
fact that both abstraction and ideals are subject to variability in time within
an individual and between individuals. Variability, which is a cherished source
for evolutionary selection, can also be an isolating and individualizing feature
in society. Thus the very features of the human brain which underlie our enormous
evolutionary success can also be a major source of our misery.
PMID- 10670025
TI - The future of philosophy.
AB - There is no sharp dividing line between science and philosophy, but philosophical
problems tend to have three special features. First, they tend to concern large
frameworks rather than specific questions within the framework. Second, they are
questions for which there is no generally accepted method of solution. And third
they tend to involve conceptual issues. For these reasons a philosophical problem
such as the nature of life can become a scientific problem if it is put into a
shape where it admits of scientific resolution. Philosophy in the 20th century
was characterized by a concern with logic and language, which is markedly
different from the concerns of earlier centuries of philosophy. However, it
shared with the European philosophical tradition since the 17th century an
excessive concern with issues in the theory of knowledge and with scepticism. As
the century ends, we can see that scepticism no longer occupies centre stage, and
this enables us to have a more constructive approach to philosophical problems
than was possible for earlier generations. This situation is somewhat analogous
to the shift from the sceptical concerns of Socrates and Plato to the
constructive philosophical enterprise of Aristotle. With that in mind, we can
discuss the prospects for the following six philosophical areas: (1) the
traditional mind-body problem; (ii) the philosophy of mind and cognitive science;
(iii) the philosophy of language; (iv) the philosophy of society; (v) ethics and
practical reasons; (vi) the philosophy of science. The general theme of these
investigations, I believe, is that the appraisal of the true significance of
issues in the philosophy of knowledge enables us to have a more constructive
account of various other philosophical problems than has typically been possible
for the past three centuries.
PMID- 10670023
TI - The past, the future and the biology of memory storage.
AB - We here briefly review a century of accomplishments in studying memory storage
and delineate the two major questions that have dominated thinking in this area:
the systems question of memory, which concerns where in the brain storage occurs;
and the molecular question of memory, which concerns the mechanisms whereby
memories are stored and maintained. We go on to consider the themes that memory
research may be able to address in the 21st century. Finally, we reflect on the
clinical and societal import of our increasing understanding of the mechanisms of
memory, discussing possible therapeutic approaches to diseases that manifest with
disruptions of learning and possible ethical implication of the ability, which is
on the horizon, to ameliorate or even enhance human memory.
PMID- 10670026
TI - Smell diskettes as screening test of olfaction.
AB - A screening test of olfaction was developed with reusable diskettes as
applicators of 8 different odorants. Using a questionnaire with illustrations,
the test was designed as a triple forced multiple choice test resulting in a
score of 0 to 8 correct answers. To validate the test, 102 volunteers with normal
olfaction, as well as 22 patients with subjective hyposmia or anosmia, were
tested. To compare the developed test with an already validated method, the same
persons also performed the sniffin' sticks screening test. The results indicate
that the screening test with smell diskettes recognizes patients with normal
olfaction and consistently distinguishes them from patients with hyposmia or
anosmia.
PMID- 10670027
TI - A new approach to improving illumination in the nose during endonasal surgery.
AB - Despite improvements in light sources the problem of illumination during
endonasal surgery persists. This is particularly so in the presence of blood
which absorbs light and renders the operative field dark as a consequence. This
paper describes a series of in vitro experiments that show how improved
illumination is possible using readily available, inexpensive, sterilisable and
flexible materials. The hypothesis tested was that white coloured materials, when
placed into the nasal cavity during endonasal surgery, improve illumination of
the operative field by reflecting light onto the area of surgical interest. This
hypothesis was tested with the use of a light proof box into which were
introduced blood coloured and reflective materials. The light reflected back from
a fixed blood coloured surface within the box was measured. The introduction of
white materials into the box provided greater illumination than blue or foil
surfaces.
PMID- 10670028
TI - Management of sinonasal hemangiopericytomas.
AB - The purpose of the present study is to report four cases of sinonasal
hemangiopericytoma (HP) diagnosed and treated in our department between 1987 and
1998. The pretreatment findings and the treatment are described and discussed in
the light of the literature. HP are unusual vascular tumors, featuring pericytes
distributed around normal vascular channels. Two of these four cases were located
in the nasal cavity and the other two were located in the maxillary sinus. Inside
the nasal cavity, HP presented as a protruding reddish-gray mass with marked
bleeding on contact. Electron microscopy and immunohistochemical techniques are
essential for diagnosis and to distinguish HP from other sarcomatous tumors.
Preoperative assessment included routine CT, MRI, arteriography and selective
embolization. These tumors must be treated surgically with complete excision. An
endonasal approach was performed in two cases of intranasal HP, while a combined
external-endonasal approach was required for the other two cases of HP.
PMID- 10670029
TI - p53 over-expression and its correlation with PCNA index in nasal polyps.
AB - Our knowledge about the etiopathogenesis of nasal polyps (Nps) is still limited.
In this study, in order to define the biological features of these neoformations,
we investigated with immunohistochemistry the p53 over-expression and the
proliferating cell nuclear antigen (PCNA) in 32 cases of Nps and in normal mucosa
of 11 control cases. The evaluation of PCNA showed a wide range of indices (0.5
18.2%) with a mean value (6.8%) significantly higher than in normal mucosa
(2.9%). Over-expression of the p53 oncoprotein, observed in 50% of Nps, was
statistically related to a high PCNA-index (> 6.8%). Our results suggest that Nps
can behave, in a high percentage of cases, like tumours.
PMID- 10670030
TI - How to manage patients with hard-to-recognize postnasal drip?
AB - Postnasal drip (PND), commonly regarded as a phenomenon wherein nasal fluid drips
into the pharynx, is one of the main symptoms of chronic sinusitis and other
nasal lesions. This definition is controversial, however, because some patients
have PND with no evidence of fluid either in the oropharynx or around the
choanae. Among 220 patients in whom PND was diagnosed at the University of Tokyo
Hospital between January 1996 and December 1997, 19 (8.6%) had hard-to-recognize
PND on routine examination. Through careful observation, responsible lesions
could be identified in all patients with hard-to-recognize PND. Seven patients
had latent chronic sinusitis, 5 had nasopharyngeal lesions, such as Tornwaldt's
cyst and inflammation, 3 had "old man's PND", 2 had "reflux PND", and 2 had
polyps around the sphenoid ostium. Five patients received no treatment. In the
other patients, medical therapy, mainly long-term treatment with low doses of
macrolides, now regarded as a standard regimen for intractable chronic sinusitis
in Japan, was effective in alleviating symptoms regardless of the cause.
PMID- 10670031
TI - Non-specific nasal provocation test with histamine. Analysis of the dose-response
curve.
AB - Non-Specific Nasal Hyper-reactivity (NSNH) is described as a clinical condition
characterized by the presence of rhinitic symptoms that are a consequence of non
specific stimulations. Because of its effects on vascular, epithelial, and
glandular receptors, NSNP Test (NSNPT) with histamine allows the study of NSNH.
The aims of this study are 1. to analyze the behavior of NSNH both in non
allergic chronic vasomotory patients and in healthy control subjects 2. to
correlate total nasal resistance(TNR) to each dosage of histamine to derive the
dose/response curves and 3. to study these curves to analyze and possibly define
different stages according to the intensities of response of NSNH. We have
studied 26 subjects affected by non-allergic vasomotor rhinitis and 10 healthy
control subjects. We sprayed a NSNPT with histamine-phosphate (0.2-0.3-0.4-0.5
0.6-0.8 mg) in different sessions to avoid accumulation phenomena. Five minutes
before and five minutes after each challenge, TNR was determined by active
anterior rhinomanometry. TNR was correlated to the doses of histamine by an
empirical equation. The most important results of this study are as follows: a)
the variation of TNR follows a model of exponential curve, b) it is possible to
classify NSNH, as a function of the regression b coefficient belonging to the
empirical equation used, in reactivity classes, c) from one reactivity class to
another, post-stimulation TNRs double; 0.5 mg of histamine of the NSNPT is the
optimal dose, d) there is an overlap between the responses of some normal
subjects and rhinopathic patients that will be the subject of a further study.
Finally, our data suggest that, in a future perspective, it is possible to use
the NSNPT with histamine for diagnostic, prognostic and therapeutic control
purposes.
PMID- 10670032
TI - Experimentally induced nasal irritation.
AB - The aim of this study was to develop a method that is suited for the induction of
nasal irritation. For this purpose inflammatory responses were analysed after
challenging the nasal mucosa with experimentally induced cold, dry air (8 l/min,
22 degrees C, 20 %RH). To assess inflammatory effects we determined inflammatory
mediators (prostaglandin E2 [PGE2], thromboxane B2 TXB2[, peptide leukotrienes
pLT: LTC4, LTD4, LTE4[) in nasal lavage fluid which was sampled before,
immediately after suprathreshold stimulation, and one hour after termination of
the stimulation. In addition, subjects estimated the intensity of pain during the
stimulation. Cold, dry air produced strong painful sensations which increased
throughout the stimulation period. A significant increase of the inflammatory
mediator pLT was observed after stimulation; mean concentrations of PGE2 and TXB2
also showed a tendency to increase. One hour after termination of the stimulation
the concentration of these inflammatory mediators returned to baseline which
indicates the reversibility of the effects of nasal irritation. These data
suggest, that this model may be a useful tool in investigations of mucosal
irritation as, for example, induced by environmental agents.
PMID- 10670033
TI - Technical problems with protein extraction of chemokines featuring RANTES.
AB - Chemokines are known to be one of the sources for eosinophilic tissue
infiltration in eosinophilic inflammation. Detection of beta-chemokines such as
RANTES was possible in nasal tissue with or without eosinophilic infiltration.
The concentration of chemokines which has been measured in the same tissue
differs often in the literature. Aim of this study was to compare the different
techniques of protein extraction and help to understand and interpret the
investigation on RANTES secretion. Tissue of nasal polyps, inferior and middle
turbinate was cut into halves and every half on its own pulverized using liquid
nitrogen. The protein extraction was performed either with citric acid solution
(pH 2.5) or phosphate buffered saline (PBS). The samples were then lyophilized.
The concentration of RANTES was measured by a specific double sandwich ELISA.
Using the citric acid technique the average concentration of RANTES in middle
turbinates was 1.3 ng/mg, in inferior turbinates 1.6 ng/mg and in polyps 2.6
ng/mg tissue, using the PBS technique respectively 0.6 ng/mg, 0.5 ng/mg and 0.8
ng/mg tissue. Our data revealed a mismatch of 3.3:1 for polyps (citric acid:
PBS), 3.2:1 for inferior and 2.2:1 for middle turbinates, respectively.
Consequent comparison between the results of different techniques was not
possible. Of special interest was also the fact that different techniques had
different efficiencies of protein extraction in different tissues. Present
statements on RANTES concentrations as a prognostic factor in nasal tissues need
a technically careful standardization as far as this study shows.
PMID- 10670034
TI - An algorithm for the management of CSF rhinorrhoea illustrated by 36 cases.
AB - The diagnosis of cerebrospinal fluid (CSF) rhinorrhoea should be established
beyond reasonable doubt before surgical intervention is embarked upon. It is
important not to miss the diagnosis in view of the real potential complication of
meningitis if it is left untreated. We describe a management algorithm which
centers around the selective use of nasal endoscopy, immunofixation of beta2
transferrin, high resolution coronal CT scans, and fluorescein lumbar puncture.
This management strategy is illustrated with 36 cases. We have developed a
minimally invasive endoscopic technique to repair CSF leaks, and in 30 patients
we had a success rate of 93% after one procedure.
PMID- 10670035
TI - Intrasphenoidal encephalocele and spontaneous CSF rhinorrhoea.
AB - Intrasphenoidal encephalocele is a rare clinical entity. In the international
literature only 16 cases have been reported up today, with female predominance.
Clinically they manifest at middle and advanced ages (40-67 years), when
spontaneous CSF rhinorrhoea or recurrent meningitis occurs. We present our case,
a 46 years old female, who had CSF rhinorrhoea from the right vestibule for 10
months. The diagnosis was based on the history and the high-resolution brain and
skull base CT-scanning in conjunction with opaque fluid injection in the
subarachnoidal space through a lumbar puncture. She was successfully treated with
an operation, through an endonasal trans-ethmoid microendoscopic approach, using
the Draf and Stammberger technique. We discuss the pathogenesis of the
intrasphenoidal encephalocele, the existence of small occult defects in the skull
base, which cause, at the middle and advanced ages, CSF fistula with spontaneous
CSF rhinorrhoea and/or recurrent meningitis. Finally we emphasize the advantages
of the endonasal surgical approach for the treatment of this condition.
PMID- 10670036
TI - Paranasal mucous cyst: a rare finding following septorhinoplasty.
AB - Postoperative niucous cysts of the facial soft tissue are a rare complication
after septorhinoplasty. We present a case of postseptorhinoplasty mucous cyst
with a paranasal localisation. According to the literature available to us this
localisation is extremely rare and has not been described before. Aetiology and
possibilities to decrease the risk of such complications are discussed.
PMID- 10670037
TI - [New recommendations for the treatment of the hypertensive patient: a theoretical
concept or a useful tool in practice?].
PMID- 10670038
TI - [Highlights of rheumatology 1999: new developments between immunology and pain of
movement mechanisms].
PMID- 10670039
TI - [The craft of robotic orthopedic surgery and Y2K].
PMID- 10670040
TI - [Advances in urology: the responsibility of family practice development].
PMID- 10670041
TI - [Oncology 1999: advances in immunotherapy].
PMID- 10670042
TI - [Medical treatment of heart failure: old facts in new lights].
PMID- 10670043
TI - [Hematology: clarity on the 75th birthday--a start in the new year with new
ideas].
PMID- 10670044
TI - [Nephrology 1999: substantial Swiss contributions].
PMID- 10670045
TI - [Gynecology 1999].
PMID- 10670046
TI - [Hepatitis B: when to use lamivudine?].
PMID- 10670047
TI - [Arterioportal fistula as a cause of esophageal varices bleeding].
PMID- 10670048
TI - Imaging of middle ear pathology.
PMID- 10670049
TI - Imaging of salivary gland disease.
PMID- 10670050
TI - Oral cavity, oropharynx, and hypopharynx.
PMID- 10670051
TI - Imaging of the larynx.
PMID- 10670052
TI - Imaging of lymph nodes in the neck.
PMID- 10670053
TI - Appropriate use of ultrasonography in the neck.
PMID- 10670054
TI - Suprahyoid spaces of the head and neck.
PMID- 10670055
TI - Applications of interventional neuroradiology in the head and neck.
PMID- 10670056
TI - Imaging of postoperative larynx and neck.
PMID- 10670057
TI - Post-therapeutic imaging of upper aerodigestive tract tumors.
PMID- 10670058
TI - [Mobility of the back of the foot and myoelectric activity pattern in jumping
exercises under increased stretching].
PMID- 10670059
TI - [Achilles tendon rupture: epidemiology, etiology, diagnosis and current treatment
possibilities].
AB - Treatment of Achilles tendon rupture is up to date not standardized. Open
surgical repair in different techniques, percutaneous repair and conservative
treatment is controversial in discussion. The following paper shows the different
techniques used today in Achilles tendon rupture. Results are represented and
discussed. Followed by a recommendation of treatment in acute Achilles tendon
ruptures.
PMID- 10670060
TI - [Muscle strength after surgical treatment of ruptures of the long biceps tendon
by refixation to the short head].
AB - Operative treatment for ruptures of the long biceps tendon still is discussed
controversially. In the present literature surgical repair is advised for
sporting and high demand patients due to favourable functional results and low
loss of strength. Until now only few objective and reproducible results were
published. In the present literature the keyhole-technique is recommended due to
favourable bio-mechanical conditions. To evaluate postoperative strength 19
patients were investigated after an average follow-up of 6.5 years, by clinical
examination and isokinetic measurement. Compared with the non-operated shoulder
isokinetic determination of isometric maximal peak torque and strength during
concentric stress for elbow-flexion, shoulder-abduction and shoulder-flexion
yield to almost identical results for the operated shoulder. According to the
criteria of the Constant-Score all patients achieved very good and good results.
Refixation to the short head can be advised for treatment of ruptures of the long
biceps tendon due to the certain technique with a low complication rate and very
good functional outcome.
PMID- 10670061
TI - [Years of training: a new risk factor in acute badminton injuries].
AB - The incidence of badminton injuries is low compared with other sports, but acute
injuries are generally more severe. Little is known about the risk of competitive
badminton players to get an acute badminton injury. The purpose of this study was
to define for the first time "years of playing badminton on a competitive level"
as a risk factor for acute badminton injuries. 179 badminton injuries of 102
Austrian competitive badminton players, some of them being elite players in the
european championships, were retrospectively registered. The years 1993, 1994 and
1995 were covered by our investigation. Injury incidences were defined as
injuries/1000 h and were calculated separately for the 0. through the 21st year
of competitive badminton. The incidence of acute badminton injuries increased
constantly from the 0 to the 7th year of competitive badminton. The 6th and 7th
year of competitive badminton showed a threefold increased incidence of acute
badminton injuries when compared with the first year and the late years of the
career as a competitive badminton player. We found no correlation between the
incidence of acute badminton injuries and age, gender, hours played per year or
time of warming up. We conclude that players being engaged in competitive
badminton for 5 to 8 years represent a high risk population for acute badminton
injuries. In contrast players at the beginning and towards the end of the
competitive career showed a markedly lower risk for acute badminton injuries. We
recommend additional training efforts concerning technical skills and endurance
as well as proper rehabilitation of sports injuries for the high risk group of
badminton players.
PMID- 10670062
TI - [Injury and exertion patterns in football on artificial turf].
AB - This controlled non-selected cross-sectional study supplies a basic survey on the
topic analysing 1783 injuries in 433 of 736 athletes out of a closed collective.
Aged 11 to 40 years and having played an average of 3.7 years an artificial turf
the players had sustained 38% skin injuries (58% in the legs), 28% sprains (64%
in the ankle joints, 21% in the knee joints) and 17% muscle injuries. 76% of all
injuries were minor, i.e. leading to an interruption of under one week, only 8%
were severe with a break of over 3 weeks. The average risk of injury was 6 per
1000 hours of participation, similar to that in football on natural grass. More
than half of the players protocol pain in the joints, muscles or column
persisting even one day after the game, which only led to medical assistance in
3% of all cases. Playing football on artificial grass displays a specific pattern
of injuries and exertion syndromes without a higher rate or grade of injuries and
therefore shows no medical need for restriction.
PMID- 10670063
TI - [Injury mechanisms in windsurfing regatta].
AB - In a retrospective study, we evaluated the injuries of 44 semi-professional
competitors for the German Windsurf Cup, which were suffered from during one
windsurfing season. This Cup is the national qualification tour for the annual
"production fun board world championship". The subjects, participating in our
study were randomly chosen. There were no surf-specific differences between the
two groups. The average age was 24.63% had competitive surfing as their hobby,
37% were professional or semi-professional board sailors. The subjects surfed an
average of 85 days in 1995. 23 (52%) windsurfers did not get hurt during the
entire season. 21 (48%) of them got injured during the 1995 windsurf season. This
is an incidence of only one injury per 174 windsurfing days. Only three
windsurfers were injured during a competition. The other 18 occurred during
training sessions. Most accidents happened because of an overpower situation,
i.e. the sail was too big for the wind force (43%), or through negligence on the
part of the windsurfer (19%). The most frequent type of the accident was the so
called catapult crash (57%). The most common injuries were ligament ruptures of
the lower leg (33%) and head burst wounds (19%). Compared with other competitive
fun sports (e.g. snow boarding), windsurfing has a lower injury risk. In regard
to the injury mechanisms, prophylactic recommendations are made.
PMID- 10670064
TI - [Extra-articular localization of nodular synovitis: a case report].
AB - INTRODUCTION: The extra-articular nodular synovitis is regarded as a rare case of
the common pigmented villonodular synovitis. The following report points out a
case with wide extension in a young man's proximal lower leg. CASE-REPORT: A 24
year-old man complained about a non-painful tumor at his left proximal lower leg
without any clinical handicap. Some years before he got a fracture of the
proximal left tibia caused by an adequate sports trauma. So he had to undergo two
operative investigations. The radiographs showed a transparent soft tissue tumor,
which displaced the corticalis of the bone for some centimeters. The magnetic
resonance imaging did not hint at a malignant process. After operative treatment
the diagnosis was confirmed by histology. CONCLUSION: By operative and
histological investigation advice could given to a benign tumor. The etiology of
the extra-articular nodular synovitis is to be regarded as unknown. In our case a
dislocation of synovial cells to extra-articular should be discussed.
PMID- 10670065
TI - [Innovations in technique and use of ultrasound].
PMID- 10670066
TI - [Medical time requirements for abdominal ultrasound diagnosis].
PMID- 10670067
TI - [Ultrasound-guided transthoracic puncture].
AB - The diagnosis of peripheral lung foci may prove difficult. In addition to
transthoracic puncture under X-ray fluoroscopy or CT control, ultrasound-guided
puncture was shown to be a useful alternative. A prerequisite, however, is that
the lesion should extend up to the pleura. This overview covers 97 original
papers, of which 26 mainly consisted of lung punctures in a total of 1876
patients. The accuracy in carcinomas and metastases was 70 to 97%, on average
markedly higher than 90%. Benign lesions are histologically more difficult to
distinguish; here the accuracy is 70%. Partly due to pre-selection the method has
a very low rate of complications. The rate of pneumothorax is 2.6%, those
requiring drainage are about 1%. Haemoptyses occur 1-2% of the punctures, most
commonly in cases of chronic pneumonia; colour-coded Duplex sonography is
especially recommended in these cases because of the strong and regular
vascularisation. The rate of complication increases in direct proportion to
needle thickness. The possibilities of ultrasound-guided lung abscess drainage
are also discussed. An intrathoracic lesion that is accessible to ultrasound
imaging should be punctured today under ultrasound guidance, as this procedure is
minimally stressful for the patient, is accurate, has a low rate of complications
and is also cost effective.
PMID- 10670068
TI - [Project graph technique for time management in abdominal ultrasound
evaluations].
AB - PURPOSE: German insurance companies are cutting down the time required for
ultrasound examinations. To determine the minimal examination time to perform an
ultrasound examination a project graph technique was applied. MATERIALS AND
METHODS: Time measurements of abdominal ultrasound examinations were performed by
two independent observers. The different jobs for the performance of an
ultrasound examination were determined and the critical pathway method applied.
The total available time for abdominal ultrasound examinations (leeway) was
determined, the minimal time to perform each job was measured and the critical
time required for the procedure was calculated. RESULTS: 14 different jobs were
identified to complete one abdominal ultrasound examination. The project graph
displayed the shortest possible time of 24 minutes to perform an ultrasound
examination. The pure ultrasound exam without colour Doppler examination was 6
minutes ("hands on the ultrasound probe"). The jobs performed by the physician
were fully within the critical period. In consequence, the physician had no
leeway or time lag in relation to a total time of 24 minutes for an ultrasound
examination, whereas by contrast the nurse has a total leeway of 7.5 minutes.
CONCLUSIONS: The applied project graph technique is an effective instrument for
the purpose of quality management for hospitals as well as in private practice.
The workflow and actions necessary to perform a treatment or examination can be
analysed. Human resources management and cost planning should be performed on the
basis of project graphs.
PMID- 10670069
TI - [Intestinal B-mode sonography in patients with endemic sprue. Intestinal
sonography in endemic sprue].
AB - AIM: The value of ultrasonography in the diagnosis, follow-up and for the
detection of complications in patients with celiac sprue has not yet been
sufficiently evaluated. A pronounced back and forth motility with echo-rich hump
reflexes in a fluid-filled small bowel with a reduction of Kerckring's plicae
circulares and with a loss of their density and uniformity was empirically
defined as a diagnostic sign of celiac sprue. In the present study, the
sonographic signs of celiac sprue were examined as an indicator of active sprue.
METHOD: 50 patients with histologically proven celiac sprue were examined with
real time ultrasonography (3.5-7 MHz). The detection or exclusion of the defined
sonographic signs of celiac sprue with intensified motility and reduction of
Kerckring's plicae circulares with a loss of their density and uniformity were
evaluated by two independent examiners and documented without knowledge of the
clinical findings. The clinical activity (active vs. remission) was assessed
according to clinical criteria (diarrhea, steatorrhea, weight loss). 38 healthy
subjects and 50 patients with Crohn's disease served as controls. RESULTS: In all
138 patients and controls adequate visualization of the bowel was achieved. In
16/50 (32%) patients with active celiac sprue changes of motility and reduction
of Kerckring's plicae circulares with a loss of their density and uniformity were
detected, whereas all 34/50 (68%) of patients with celiac sprue in remission did
not have this pattern. In none of the controls with Crohn's disease or in the
healthy subjects comparative sonographic signs of active celiac sprue were
observed. In four patients with active celiac sprue a circumscript echopoor tumor
of the small bowel wall could be sonographically detected, which turned out to be
T-cell lymphoma in three and a carcinoma of the small intestine in one patient.
An increased number of and/or enlarged mesenteric lymph nodes were found in
patients with active celiac sprue. CONCLUSION: Changes of motility and reduction
of Kerckring's plicae circulares with loss of density and uniformity at
ultrasonography are a reliable indicator of active celiac sprue.
PMID- 10670070
TI - [A test object for quality control of the instrument for doppler (duplex)
ultrasonography, based on the Draft IEC 61685 Standard].
AB - PURPOSE: The authors, forming part of a multicenter project funded by the
European Community, summarize the validation of a tissue-mimicking flow Doppler
test object and of procedures for testing medical diagnostic Doppler equipment.
The results of the project are expected to contribute to a future international
IEC Standard concerning flow Doppler test objects (Draft IEC 61685 Standard) and
for the European Medical Device Directive (MD 93/42/EEC). METHODS: Within this
project a test protocol was developed that includes a set of different
procedures, suitable for checking Spectral and Colour Doppler systems. The
performance parameters for describing the image quality as well as the accuracy
and the correct functioning of a system are in accordance with the definitions
made in the Draft IEC 61685 Standard. RESULTS: A survey of the design and
materials used for this Doppler test object will be presented with a special
emphasis on the suitability of the procedures for routine measurement of
performance parameters in hospitals. CONCLUSION: The test object satisfies the
requirements of the Draft IEC 61685 Standard. The test procedures in combination
with this test object can be used for checking different transducer models with
nominal frequencies between 2.5-10.0 MHz.
PMID- 10670071
TI - [Deep vein thrombosis following total arthroplasty hip replacement.
Ultrasonographic screening in the rehabilitation phase].
AB - Deep vein thrombosis requires intensive therapy--either the patients require
hospitalisation or their rehabilitation scheme must be adjusted and medical
treatment applied. The total number of patients with deep vein thrombosis
undetected before admission to rehabilitation facilities is unknown. AIM: Study
parameters: 1. The occurrence of undetected deep vein thrombosis upon admittance
to a rehabilitation facility. 2. The value of sonography in diagnosing,
localising and determining the extent of deep vein thrombosis and 3. the
influence of prophylactic antithrombotic treatment applied in the surgical
hospital, as well as during the intermittent outpatient phase before admittance
to the rehabilitation centre, on the occurrence of deep vein thrombosis. METHODS:
305 patients were examined between Nov. 95 and Dec. 96. The first check was
carried out on the day of admission (on the 26th postoperative day, on average).
The second check was done on the day of discharge from the rehabilitation centre.
RESULTS: Deep vein thrombosis was found in 30 patients (10%). In 27 cases the
thrombosis was located in the thigh, in one case it was found in the
contralateral leg. 18 of these patients had been discharged from the surgical
hospital on the 22nd postoperative day, for an average time of 7 days of
outpatient care, before being admitted to the rehabilitation centre. 11 of these
patients had not received any prophylactic antithrombotic treatment. One patient
developed deep vein thrombosis of the thigh during the rehabilitation phase
despite of prophylactic treatment. CONCLUSION: Postoperative sonographic
screening of all patients undergoing hip surgery is a useful method to detect
deep vein thrombosis. Prophylactic postoperative antithrombotic treatment in the
rehabilitation phase is mandatory.
PMID- 10670072
TI - [Clinical manifestations of schizencephaly and its sonographic diagnosis].
AB - Schizencephaly is defined as a cerebral malformation of the CNS with various
clefts of the cerebral cortex. We report on two patients referred to our
department with neurological abnormalities. In both cases the cranial sonography
already provided for the clinical picture of schizencephaly. A MR-scan confirmed
the diagnosis. In addition one of the patients proved to have a migrational
disorder. The analysis of these cases and the relevant literature point out how
difficult the etiologic differentiation is and, on the other hand, how various
the manifestations of the malformation can be. The important role of cranial
sonography as a screening method is shown.
PMID- 10670073
TI - Pitfall: a pseudo tumor within the left liver lobe presenting with abdominal
pain, jaundice and severe weight loss.
AB - A 51 year old male patient with a history of chronic alcohol consumption and
recurrent pancreatitis was referred to our hospital with jaundice, epigastric
pain, severe diarrhoea and weight loss of 28 kg within the last 12 months. A CT
scan of the abdomen 4 months before admission had shown a pancreatitis with free
fluid around the corpus and tail of the pancreas as well as dilated intrahepatic
bile ducts and a cavernous transformation of the portal vein. Moreover, a tumor
(3.5 x 3.0 x 3.6 cm) with irregular contrast enhancement was seen within the left
liver lobe. The patient was referred to us for further evaluation and treatment.
The initial B-Mode sonogram revealed a bull's eye like well defined lesion (8.1 x
7.5 x 7.0 cm) within the left liver lobe, consistent with a tumour or abscess.
Prior to a diagnostic needle biopsy a PTCD was performed in this case presenting
with dilated intrahepatic bile ducts and having a history of Billroth II
operation. An additional colour coded Duplex Doppler ultrasonography demonstrated
a visceral artery aneurysm and prevented us from performing the diagnostic
puncture. The aneurysm was assumed to originate from a variant or a branch of the
left hepatic artery. Angiography revealed a pseudoaneurysm of the
pancreaticoduodenal artery and coil embolization was performed because of the
increasing size and the risk of a bleeding complication. Postinterventional
colour duplex ultrasound measurement showed no blood flow within the aneurysm.
Retrospectively, the pseudoaneurysm must have led to a compression of the common
bile duct, since the patient did not develop cholestasis after embolization and
removal of the PTCD. Thus, a pseudoaneurysm of the pancreaticoduodenal artery
must be included in the differential diagnosis of liver tumours in patients with
chronic pancreatitis, despite its unusual localization near the liver. Therefore,
we suggest that colour coded ultrasonography should be applied to any unclear,
bull's eye like lesion, even though this method alone cannot exactly determine
the origin of the pseudoaneurysm. Interventional angiography remains the gold
standard for the diagnosis and therapy of visceral artery aneurysm.
PMID- 10670074
TI - [On the article: Bock, U., Mollhoff, T., Forster, R.: Ultrasonography guided
versus anatomically oriented puncture of the internal jugular vein for central
venous catheterization].
PMID- 10670075
TI - Adaptation of pregnant ewes to an exclusive onion diet.
AB - A diet consisting entirely of cull onions fed to pregnant ewes produced Heinz
body hemolytic anemia in all sheep after 21 d. After 28 d of daily consumption of
20 kg of onions/ewe, the anemia stabilized, and for the remaining 74 d the packed
cell volume increased in the majority of sheep, although it did not return to
normal. Compared to control ewes fed an alfalfa and grain diet, the onion-fed
ewes had comparable body condition scores and fleece weights. There was no
significant difference (alpha = 0.05) in pregnancy or lambing rate, number of
lambs born/ewe exposed, or number of lambs born/ewe lambing. Greater numbers of
sulfate-reducing bacteria (Desulfovibrio spp) and more ruminal hydrogen sulfide
were present in onion-fed sheep compared to controls. Although an average 27%
reduction in packed cell volume and Heinz body anemia developed in the onion-fed
ewes, on the basis of this study it appears that pregnant ewes may be fed a pure
onion diet with minimal detrimental effects. This adaptation to a pure onion diet
is in part likely due to the apparent ability of the sheep's rumen to quickly
develop a population of sulfate-reducing bacteria that decrease the toxicity of
onion disulfides.
PMID- 10670076
TI - Histopathological effects of cyphenothrin on the gills of Lebistes reticulatus.
AB - We observed the histopathological effects of several doses of cyphenothrin. Adult
guppies (Lebistes reticulatus) were placed in water containing 34.8, 46.5, 53.5
or 60 micrograms cyphenothrin/L for 96-h and their gills examined. The most
common changes at all cyphenothrin doses were the lifting of the epithelial layer
from gill lamellae and some necrosis. Degeneration of secondary lamellae due to
edema, the shortening of secondary lamellae, and club-shaped lamellae were also
observed. The 96-h LC50 for cyphenothrin to Lebistes reticulatus was 48.7
micrograms/L.
PMID- 10670077
TI - Black walnut induced laminitis.
AB - A 5-y-old Paint horse gelding was evaluated for acute laminitis after exposure to
black walnut shavings. The gelding's feet were previously soaked in an ice bath
continuously for approximately 24 h. Treatment consisted of anti-inflammatory and
vasodilator therapy. Serial radiographs revealed progressive palmar deviation of
the third phalanx and subsolar abscesses in both forefeet. The gelding developed
purulent discharge from the right coronary band and the hoof wall detached
circumfrentially. Euthanasia was elected after 54 days. Continual exposure of the
gelding's feet to ice water temperatures may have caused decreased perfusion and
increased edema formation in the laminae resulting in decreased blood flow and
exacerbating the existing ischemic necrosis.
PMID- 10670078
TI - Anaphylactoid reaction to rattlesnake envenomation.
AB - The clinical manifestations of an anaphylactoid reaction are identical to true
anaphylaxis; however, a previous exposure to the offending agent is not needed to
manifest these symptoms. We present a case of an anaphylactoid reaction in a 62-y
o female following a first-time envenomation by a rattlesnake. The patient
required s.c. epinephrine and i.v. diphenhydramine, methylprednisolone, and
ranitidine. She had not been envenomated by a rattlesnake previously or received
any horse-derived antivenins in the past.
PMID- 10670079
TI - Cestrum laevigatum poisoning in goats in southeastern Brazil.
AB - Natural and experimental poisonings by Cestrum laevigatum are described in goats.
Histologically, livers had marked centrolobular and midzonal coagulative necrosis
and hemorrhage. Spontaneous toxicosis by this plant in goats has not been
previously reported.
PMID- 10670080
TI - Topical absorption of isopropyl alcohol induced cardiac and neurologic deficits
in an adult female with intact skin.
AB - Topical exposure to isopropyl alcohol has been reported in the literature to be
toxic if sufficient isopropyl alcohol is absorbed (1-5). A clinical case is
reported where a 48-y-old female presented with multiple unexplained cardiac and
neurological deficits. The woman had developed the deficits over a 6-mo period in
which she had been soaking towels with isopropyl alcohol and applying then to her
skin overnight to ease arm pain she was experiencing. Cessation of the isopropyl
alcohol exposure resolved her deficits within 3 d. A controlled repeat dermal
exposure to isopropyl alcohol under clinical observation reproduced the deficits
noted with corresponding serum and urine concentrations of isopropyl alcohol and
acetone. Cessation of topical isopropyl alcohol exposure lead to subsequent
resolution of all toxicities.
PMID- 10670081
TI - Weakness, tremors, and depression associated with macadamia nuts in dogs.
AB - The ASPCA National Animal Poison Center managed 29 cases of ingestion of
commercially available macadamia nuts in dogs during a 5-y period. Clinical signs
included, from most to least, weakness, depression, vomiting, ataxia, tremor,
hyperthermia, abdominal pain, lameness, stiffness, recumbency, and pale mucous
membranes. The onset of clinical signs was reported as < 12 h in 79% of the
cases. The duration of clinical signs for the majority of cases was < 24 h. The
amount of macadamia nuts ingested was estimated in 72% of the calls with a mean
of 11.7 g/kg bw. In an attempt to reproduce the syndrome, 4 dogs were gavaged
with 20 g macadamia nuts/kg bw in a water slurry. The experimentally dosed dogs
developed weakness, manifested by the inability to rise 12 h after dosing, mild
central nervous system depression, vomiting, and hyperthermia, with rectal
temperatures up to 40.5 C. Mild elevations in serum triglycerides and serum
alkaline phosphatase were detected. Lipase values peaked sharply at 24 h and
returned to normal by 48 h after dosing. Other serum biochemical and electrolyte
determinations were unremarkable. Serum lipoprotein electrophoresis
determinations were unchanged from baseline. The mechanism of the syndrome is
unknown. All field and experimental dogs recovered uneventfully within 1 to 2 d
whether treated by a veterinarian or not.
PMID- 10670082
TI - Mercury contamination of heavy metal collection containers.
AB - We investigated discordant urinary mercury testing results from 2 patients with
potential mercury exposures. Two patients had mercury levels of 634 and > 1,000
micrograms/L respectively. Although repeat 24 h urine mercury levels were
elevated, spot urines were negative. Investigation revealed that technical HCl
with high mercury content had been added to the 24 h urine collection containers.
Subsequently, 20 hospitals were contacted to determine their heavy metals testing
procedure and to analyze the acid used for mercury. Most hospitals contacted used
acid in the preparation of their urine heavy metal collection containers. Of 13
HCl samples tested, 5 had low levels of mercury and 1 had heavy mercury content.
Acid added to heavy metal collection containers should be of high purity grade to
avoid mercury contamination of samples.
PMID- 10670083
TI - A newly emerging toxic dinoflagellate, Pfiesteria piscicida: natural ecology and
toxicosis to fish and other species.
AB - Pfiesteria, a toxic dinoflagellate, recently has emerged as a cause of fish kills
near the East Coast. Recent research into one species. Pfiesteria piscicida, has
revealed a complex life cycle of at least 24 stages. Metamorphosis of one stage
to another often depends on presence or absence of fish. Growth of P piscicida is
promoted both directly and indirectly by nutrients such as inorganic phosphate
and nitrate, as well as organic phosphate, and may be related to effluent-induced
blooms. Sewage and agricultural runoff flowing into estuaries often provide these
nutrients and may be correlated with the majority of fish kills in the Atlantic
coastal region of the US (5). P piscicida is extremely toxic, with a low density
capable of killing fish within 3 minutes (1,3,12). Fish exposed to sublethal
doses of the toxin have prominent lesions. The syndrome leads to population level
death losses and associated economic losses in local fisheries.
PMID- 10670084
TI - Ivermectin: an assessment of its pharmacology, microbiology and safety.
AB - Ivermectin (IVM) is the drug of choice for a variety of parasitic diseases due to
its broad spectrum of activity and wide margin of safety. More than 18 million
people are treated with IVM each year. Delivery modes include oral, topical, and
s.c. injections. Its anti-parasitic activity depends upon species and
developmental stages. Although IVM is believed to act mainly through interactions
with invertebrate glutamate-gated chloride (GluCl) channel, other targets such as
spleen cells and aminobutyric acid receptors may play important roles in the anti
parasitic activity of IVM. As several organisms have evolved resistance to IVM
through mutations in p-glycoproteins and/or the GluCl channel itself, research
continues on improvement of IVM either through mode of administration or the
feasibility of alternative macrolides. An understanding of IVM's pharmacology is
essential before improved therapeutics are created.
PMID- 10670085
TI - Finding an optimal dose: considerations in accurate opioid dispensing.
AB - Morphine sulfate is widely prescribed for the relief of moderate to severe acute
and chronic pain. Unfortunately, medication errors associated with morphine
sulfate can result in patient harm; profound respiratory depression can result
from excessive doses in opioid-naive patients. An actual medication order
containing a potentially toxic overdose of morphine sulfate is examined. Patients
habituated to high doses of morphine sulfate are at risk from underdosing, a
hazard also of concern.
PMID- 10670086
TI - Examining the contribution of infant walkers to childhood poisoning.
AB - Parents frequently utilize baby walkers in their infants of approximately 5-15 mo
of age and create opportunities for traumatic accidents. Healthcare professionals
have tried to increase awareness of their dangers; despite this, between 1986 and
1991 reported walker-related accidents rose 45%. We determined if walkers were a
significant contributor to childhood poisonings and what toxins were encountered
most commonly. A 14-mo prospective study in a regional poison information center
determined the prevalence of accidental pediatric poisonings in children aged 5
15 mo old who suffered their exposure while in a baby walker. The regional poison
information center managed 7.058 poisoning exposures, 2.8% of which occurred
while the child was in an infant walker. The mean age was 8.25 mo (range 5-14
mo), with 96% less than 12 mo. Substances involved were: plants 56.7%, cleaning
products 9.9%, cosmetics 5.5%, construction supplies 5.0%, cigarettes 4.5%,
topicals 4.5%, oral medications 2.0%, chalk 2.0% and miscellaneous 9.9%. The
majority (95%) of children were asymptomatic. Infant walkers contributed
substantially less to infant poisonings than was anticipated. Despite the
innocuous nature of exposures, a vulnerable population was exposed to potential
poisons within reach of their grasp. Baby walker injuries are not limited to
trauma, and accidental poisonings should be included in the admonitions that
accompany their use.
PMID- 10670087
TI - Lead contamination of imported candy wrappers.
AB - Lead toxicity in a young Hispanic woman from sucking on a terra cotta candy
container led to investigating lead contamination in candy packaging materials
imported from Mexico. Printed cellophane candy wrappers may present a significant
risk for lead exposure.
PMID- 10670088
TI - Characterization of US poison centers: a 1998 survey conducted by the American
Association of Poison Control Centers.
AB - A 1998 survey of all 73 US poison centers, including 52 certified centers and 21
noncertified centers, is presented. Despite a continued decline of the number of
poison centers operating in the US, the volume of calls has steadily increased.
In 1997 these centers handled 3.65 million telephone consultations, including
2,475,010 human poison exposure cases, 134,646 animal poison exposures, and
1,036,148 information calls. Nearly the entire US population had access to a
poison center (99.9%), although only 78.5% of the US population was served by a
certified center. Certified poison centers handled 83.6% of human poison exposure
cases reported to US poison centers. Calls to certified centers were twice as
likely to be handled by staff who were certified as specialists in poison
information. On average, poison center utilization was 9.2 human exposure
consultations/1,000 population. Total national poison center expenses approached
$81 million. The average cost/human exposure case was $33.30 in certified
centers, a substantial savings when compared with the alternative of emergency
department management. State governments provided the single largest source of
funding. Poison center funding remains unstable, with 41% of centers reporting a
possible or definite budget reduction anticipated in the next budget year. In the
past 5 y, 47.9% of centers faced threat of closure. Center certification and
increased public education activity, especially the distribution of poison
prevention materials and number of media contacts, were associated with greater
utilization of the poison center in the region served.
PMID- 10670089
TI - A very long trip to gastric decontamination!
PMID- 10670090
TI - [Surgical infections. When is a minimally invasive procedure indicated?].
PMID- 10670091
TI - [Multiorgan surgery in rectal cancer--extended therapy or improvement of
prognosis?].
AB - About 10% of rectal cancers have to be treated by a multivisceral resection.
Within a period of 14 years we performed 103 of these operations, 60 for primary
cancers, 43 for recurrent cancers with a significant increase in the latter. The
total or partial removal of 204 extra-rectal organs allowed for a R0 resection in
67% of cases. 69% were confirmed as being pT4 by histologic examination. In
comparison with conventional rectal resection morbidity is higher at 32% while
mortality is identical with 4%. A significant benefit (p < 0.05) in terms of
survival is found for primary cancers as opposed to recurrences, R0 resections
compared to R1 or R2 resections, lymphnode negative compared to lymphnode
positive patients and patients who underwent IORT. The number of additionally
removed organs did not influence survival. Compared with the natural course even
palliative resections carry a survival benefit and allow the treatment of the
often devastating specific morbidity of the disease. Despite adjuvant multimodal
therapies the high rate of local and distant recurrences after multivisceral
resection of the rectum still poses a major problem.
PMID- 10670092
TI - [Tumor genesis and prognostic factors in colorectal carcinoma with special
consideration of tumor localization].
AB - The rising incidence of colorectal carcinoma, particularly in the industrial
nations of Europe and USA, directs the attention to the aetiological factors of
these tumors: nutrition, the association with colorectal adenoma, familiarly
genetic disorders as familiar adenomatous polyposis and hereditary non polyposis
colorectal cancer. Some aspects of molecular biology are discussed. Furthermore,
right and left part of the colon (divided by the Cannon-Boehm point) and the
neoplasms of these sections of the colon are different in embryology, function
and morphology. The cancers of the right colon develop without polypoid changes,
those of the left part in majority via the adenoma-carcinoma sequence. It is
possible to demonstrate differences between these two localizations in the DNA
content (diploid tumors on the right side), in the lost of allels (especially
distal tumors), in proliferation activity (lower in right side tumors) and in the
expression of oncofetal antigens. Besides, there are some histological
differences between neoplasms of the right and left colon (production of mucin,
"Crohns like lymphoid reaction" histological grading). In our own material of 262
patients with resected colon carcinoma we have investigated the distribution of
carcinoma in the right and left colon, furthermore the T-classification,
histological grading and the proportion of mucinous carcinoma in the different
tumor localizations.
PMID- 10670093
TI - [Surgical management of locoregional recurrence of gastric carcinoma].
AB - About half of the patients with gastric cancer subjected to total gastrectomy in
curative intention die of recurrence within a few years. Most of these local
recurrences occur in the first 2 years postoperatively. In an historic analysis
133 patients of the years 1985-1997 were investigated. Local recurrence was
observed in 29 cases within 60 months on average. An intensive follow-up will not
affect the long-term outcome of local recurrence. Improved results may be
expected only if more effective therapeutic strategies for local recurrence will
be developed.
PMID- 10670094
TI - [Demand for and use of blood supply for elective surgical procedures].
AB - In elective surgical operations on thyroid gland and breast gland, in
cholecystectomy, axillary or inguinal dissections and hernioplasties blood units
are usually ordered for the operation. The aim of the study was to analyse the
real requirement of transfusions during several years and to show that in the
above-mentioned operations only in exceptional cases blood units must stand by.
METHODS: At the Surgical Hospital I of the University Leipzig, a retrospective
analysis of the anaesthetic records and patient documentations from 1994 to 1997
was performed with regard to intraoperative blood transfusions. RESULTS: There
were 1122 operations on the thyroid gland (119 of it as total thyroidectomy), 465
operations on the breast gland, 413 cholecystectomies, 70 axillary and 60
inguinal dissections and 445 hernioplasties. Intraoperative transfusions were
necessary in nine operations on the thyroid gland (0.8%), in six operations on
the breast gland 1.3%), twice in cholecystectomy (0.5%) and only once in an
axillary dissection (1.4%). The analysis of the patients' records showed in
almost all of these cases special risk factors such as disorders of blood
coagulation or thyroidal function, anaemia, serious other diseases or a necessary
extension of the operation. CONCLUSION: It is justified to perform the above
mentioned operations without a routine order of blood units. This would lead to
enormous financial savings. Because the optimal care for the patients has
priority, it is necessary to estimate the individual risk of a required
transfusion preoperatively and to keep low the blood loss by the surgeon during
the operation.
PMID- 10670095
TI - [Is there a chronic appendicitis in childhood? Analysis of pediatric surgical
patients from 1993-1997].
AB - The right lower quadrant abdominal pain and the "chronic" appendicitis in
childhood and adolescence are frequently connected with a lot of different
diagnostical problems for the treating physician. Since the introduction of
diagnostical laparoscopy and laparoscopical appendectomy in our hospital the rate
of appendectomy has been increased to 35% in case of the histological diagnosis
of "chronic" appendicitis. A special problem in childhood and adolescence is the
request of the parents for clarification of chronic recurrent pain in their
children and therefore the demand of laparoscopy and not seldom appendectomy.
After appendectomy with the pathological-histological findings of "chronic"
appendicitis children are in 83% without any abdominal pain. Therefore the
question arises whether there exists a "chronic" appendicitis in childhood
justifying surgery in these cases. Although the rate of complications and
conversions (3.8%) in diagnostical laparoscopy and laparoscopical appendectomy is
quite low the indication should only be made after careful examination
considering differential diagnostical problems. In our hospital 56.5% of the
children with the histological diagnosis of "chronic" appendicitis suffered
retrospectively on other diseases, that had been caused the symptoms of
appendicitis. Before operation the patients should be informed on the
complications in detail.
PMID- 10670096
TI - [Chronic appendicitis. Recurrent abdominal pain in the right lower quadrant from
the viewpoint of the internist].
AB - There is no clear scientific evidence for a clinically relevant chronic form of
appendicitis in the absence of acute flares. Lacking typical symptoms of acute
appendicitis or corresponding imaging findings, no indication is given for
appendectomy from the internal medicine point of view. By contrast, chronic or
recurrent right lower quadrant pain is often of functional origin and may be part
of the Irritable Bowel Syndrome or the Functional Abdominal Pain Syndrome. These
syndromes are linked to a higher rate of appendectomies in the medical history.
The Irritable Bowel Syndrome may be diagnosed based on clinical symptoms alone.
But in doubt and in considering malignancy, the indication for diagnostic imaging
is given, after ultrasound particularly by colonoscopy. For positively diagnosing
these functional syndromes, the typical clinical presentation, extraintestinal
pain syndromes, and psychic factors should be evaluated. The visceral
hypersensitivity is the predominant pathophysiologic finding and measured by
rectal distention stimuli. Medical treatment comprises relaxatives of smooth
muscle and low dose antidepressants as modulators of visceral perception. These
are supplemented by the psychosocial management.
PMID- 10670097
TI - [Differential diagnostic problems of hepatocellular carcinoma in an abnormal
additional liver lobe in the lower abdomen].
AB - This case report describes a 36 years old patient with a known tumor in her lower
abdominal cavity which increased in size in the last 16 years. Intraoperatively
an additional liver lobe of the left liver located in the lower abdominal cavity
was found in combination with a multifocal hepatocellular carcinoma which could
be treated curatively.
PMID- 10670098
TI - [Localized Castleman disease. Diagnostic difficulties in a surgically treatable
disease].
AB - Castleman's disease is a rare cause for a retroperitoneal mass. The disorder can
be classified into two histopathological groups: the hyalin-vascular and plasma
cell types. The former type, particularly in its localized form, is often
asymptomatic and benign, the surgical therapy may cure the patient. The latter
type is frequently associated with systemic manifestations and an uncertain
prognosis. We present a case in which the diagnosis of localized Castleman's
disease proved to be extremely difficult. In these cases, the correct diagnosis,
however, is indispensable, as these patients can be cured by radical surgical
tumor excision.
PMID- 10670099
TI - [Thoracoscopic treatment of pleural empyema].
AB - From August 1991 to May 1997 46 patients with pleural empyema in the
fibrinopurulent phase underwent thoracoscopic surgery. There were 36 men and 10
women with an average age of 47 years ranging from 18 to 84. The average
operating time was 77 minutes. When only one thoracostomy drain was inserted, the
drainage time was 8.5 days, if two or three drainage tubes were used it was 10.5
days. The average hospital stay was 18.1 day (range from 7 to 45). We observed
ten complications. Four operations had to be converted to an open procedure
because of massive thickening and fibrosis of the pleura. Three patients did not
tolerate one lung ventilation, once the lung did not collapse due to technical
reasons and in one patient each we observed a laceration of the parenchyma and
bleeding from the parenchyma. In both cases the problem was dealt with
thoracoscopically. We observed a recurrent pleural empyema in four patients which
occurred between the 28th and 77th postoperative day. In summary, thoracoscopic
surgery in patients with pleural empyema in the fibrinopurulent phase is an
effective and well tolerated alternative to open thoracotomy.
PMID- 10670100
TI - [Laparoscopic cholecystectomy. A recommendable indication in acute
cholecystitis?].
AB - While laparoscopic cholecystectomy has become the procedure of choice for the
elective treatment of symptomatic cholecystolithiasis the question whether
patients with acute cholecystitis should be operated laparoscopically or
conventionally is still debated. Nevertheless, more and more surgeons tend to use
the laparoscopic approach even in patients with acute cholecystitis. Of 1006
laparoscopic cholecystectomies performed at our hospital 42 were done for acute
cholecystitis. Conversion to an open procedure was necessary in only one patient
because of severe inflammatory changes. The overall mortality was zero. The
average age was 45.9 years for all patients and 50.4 years for those with acute
cholecystitis. The average operating time in patients with acute cholecystitis
was 81 minutes compared to 62 minutes in patients who underwent elective
laparoscopic cholecystectomy. The complication rate and the average
hospitalization time did not differ significantly between the two groups. Our own
data as well as the data retrieved from the literature seem to indicate that
laparoscopic cholecystectomy is superior to the open procedure in the treatment
of acute cholecystitis. Prerequisite is that the operation is performed less than
72 hours after the onset of the symptoms by an experienced operating team and the
readiness to convert to open procedure if necessary. Under those circumstances
laparoscopic cholecystectomy seems to be the treatment of choice for acute
cholecystitis.
PMID- 10670101
TI - [Role of laparoscopy in the management of acute appendicitis].
AB - Minimal invasive surgery had a considerable impact on common surgical techniques
and has almost replaced established operative procedures such as cholecystectomy.
However, the laparoscopic approach for the treatment of acute appendicitis is
still not very popular. We discuss the role of laparoscopy for appendectomy and
include three studies from our institution (University Hospital Zurich,
Switzerland) and prospective studies reported in the literature. We conclude that
laparoscopic appendectomy, when compared with the open approach, has the
following advantages for the diagnosis and treatment of acute appendicitis. (1)
Diagnostic laparoscopy is an effective and relatively atraumatic tool to
investigate the abdominal cavity, which results in a sensitivity of almost 100%.
This allows for accurate decision making, which is especially advantageous in
young women and obese patients. (2) Prospective studies demonstrate that
laparoscopic appendectomy is at least as good as open appendectomy and that the
laparoscopic approach results in a reduced postoperative infection rate. (3) The
similar complication rate after laparoscopic appendectomy, when performed by
residents rather than staff surgeons, underlines the feasibility and teaching
potential of this minimal invasive procedure.
PMID- 10670102
TI - [Laparoscopy in intra-abdominal infection. Its diagnostic value and therapeutic
possibilities].
AB - In 550 patients with the clinical features of acute abdomen a surgical
laparoscopy was performed. In 121 cases there was found an unspecific reason of
the acute abdominal disease that did not require surgical therapy. In 349 cases a
regional peritonitis was found, 80 times a diffuse peritonitis. The diagnostic
validity of laparoscopy was 96% as compared to 42% for sonography. The
laparoscopic access resulted in a complication rate of 0.2%. In 239 cases (43%)
the disease could be managed laparoscopically, 190 cases (35%) required open
surgery.
PMID- 10670103
TI - [Laparoscopic management of echinococcal cysts of the liver].
AB - Even though echinococcal cysts have been cured by puncture and instillation of
scolicidal medications, surgery is still the mainstay of the treatment of hydatid
disease. The aim of the surgical treatment is the elimination of scolices, the
removal of all viable parts of the cyst and the obliteration of the remaining
cavity. This can be achieved by resective procedures, but also by a more
conservative approach with drainage and obliteration of the cyst. The latter
procedure can be done by open surgery or laparoscopically. The disadvantages of
the laparoscopic approach are the increased danger of contamination of the
abdominal cavity with scolices and difficulties to aspirate a highly viscous cyst
content. Furthermore, cysts which are located deep in the parenchyma of the liver
should not be approached laparoscopically because of the significant danger of
hemorrhage. The advantage of the laparoscopic approach in selected cysts, i.e.
those which are located superficially and having a liquid content, are a shorter
hospital stay, lower incidence of wound infection and the ability of the surgeon
to inspect the inside of the cyst more thoroughly and rule out daughter cysts and
connections to the biliary tract. A review of the literature (n = 76) indicates
that in most laparoscopically treated hydatid cysts of the liver a simple
drainage (59%) or an unroofing (31%) is performed. The complication rate is 21%.
Because there are no longterm observations after laparoscopic operations for
hydatid disease the question of recurrence cannot yet be answered.
PMID- 10670104
TI - [Laparoscopic sigmoid resection in diverticulitis].
AB - It is still difficult to determine the exact indication for a laparoscopic
sigmoid resection for diverticular disease. Frequently, the severity of
diverticulitis is not sufficiently defined. For this reason a modification of the
Hinchey classification is proposed to which a stage II b for fistula formation
and a differentiation between acute and chronic disease have been added. Another
problem is the lack of criteria which define a "laparoscopic" resection. A
sigmoid resection should be called "laparoscopic" if the mobilization of the
sigmoid colon, the transsection of the mesenteric vein and artery and the
mesentery itself and the distal transsection of the bowel are done
laparoscopically. The resection of the bowel and the introduction of the anvil of
the stapler device can be done extraabdominally, however, the anastomosis again
should be performed laparoscopi-cally. A so defined sigmoid resection can be done
in the chronic stage I. In the chronic stage II a there will be significant
problems due to adhesion formation, and in the acute stages II a and II b as well
as in the chronic stage II b a laparoscopic resection should not be attempted.
PMID- 10670105
TI - ["Identification of of the recurrent laryngeal nerve through intraoperative neuro
monitoring."].
PMID- 10670106
TI - ["Medical malpractice in laparoscopic cholecystectomy."].
PMID- 10670107
TI - [Therapeutic principles in extensive soft tissue injuries and basic principles of
plastic defect covering].
PMID- 10670108
TI - [General infection prevention in abdominal surgery with special reference to
intestinal decontamination].
AB - In surgery prophylaxis for infection is necessary, because patients are
immunocompromised due to the underlying disease and the operation while at the
same time being increasingly exposed to potentially pathogenic germs. Prophylaxis
is based on the control of endogenous and exogenous microorganisms. For this
purpose either systemic or locally active topical agents may be employed.
Systemically active substances are applied with the aim to kill and eliminate
invasive microorganisms in deep tissue levels, either by their own biological
activity or by stimulating specific or unspecific host immune reactions. Local
topical measures in contrast are to prevent the primary contact between
microorganisms and host. The central pillar of systemic measures is the
perioperative systemic antibiotic prophylaxis, immunonutrition is beginning to
gain importance, and in the future possibly substances such as G-CSF, which
directly stimulate the immune system, may be employed. Standard topical measures
are sterilization and desinfection while decontamination of the digestive tract
has until now not found a wide spread acceptance. For certain indications
especially high risk surgical resections with anastomoses at the level of the
oesophagus or the lower rectum it is possible to eliminate endogenous intestinal
microorganisms effectively using topical decontamination in combination with
systemic antibiotics and improve the surgical results, especially anastomotic
healing.
PMID- 10670109
TI - [Perioperative infection prophylaxis in gastrointestinal surgery].
AB - Antibiotic perioperative prophylaxis is known to reduce postoperative infections
and is generally administered as single-dose regimen today. Effective prophylaxis
requires plasma- and tissue concentrations above the MIC of the expected
bacterial spectrum throughout the whole operation from skin incision to wound
closure. In longlasting operations a second dose after 4 hours is recommended.
Indications for antibiotic prophylaxis are clean-contaminated or contaminated
procedures according to Cruse and in patients with elevated risk of infection.
Generally antibiotic prophylaxis is administered intravenously. Chinolons
achieving high tissue- and plasmalevels and showing a broad antibacterial
spectrum seem appropriate to be used for oral prophylaxis. In a prospective study
in 36 patients pharmocokinetics of ofloxacin were measured perioperatively and
proper plasma- and tissue concentrations were attained. A following prospective
randomized study in 56 patients undergoing colonic or pancreatic resections oral
prophylaxis did not show a higher infection rate compared with a standard
intravenous prophylaxis. Therefore oral prophylaxis seems to be an attractive
option, its effectivity needs to be proven by studies with sufficiently high
patient numbers.
PMID- 10670110
TI - [The influence of taurolidine on physiological and pathological blood coagulation
and implications for its use].
AB - Taurolidine is an anti-infective agent with an unusually broad spectrum of
effectivity against gram-positive and gram-negative bacteria, anaerobic
organisms, and fungi. The effective principle is explained by the decomposition
of the substance and the transfer of methylol groups to specific molecular
structures of the cell walls of microbes. The acceptors are amino groups of the
amino sugars and the lysine residues of glycoproteids. More recent investigations
have shown that the effect of taurolidine is not limited to microorganisms, but
can be detected in cells of the macrorganism as well. Here the influence of
taurolidine on different blood clotting factors is described. The results can be
explained by a transfer of methylol groups to residues of arginine and histidine
in the active region, in analogy to the transfer to lysine residues in
microorganisms. It is therefore to be expected that taurolidine will influence
other vital systems of the macroorganism, dependently of concentration, as long
as their biological function is connected to residues of arginine or histidine.
Examples are the complement system and the fibrinolysis system. The implications
of these observations have to do with new indications in connection with clotting
phenomena in extracorporal circulatory systems or with thrombolysis, as well as
with known indications in cases of shock and sepsis.
PMID- 10670111
TI - [Treatment of septic complications od secondary peritonitis].
AB - The authors review the current management goals of surgical and antibiotic
therapy in secondary peritonitis. Basic therapeutic regimen is the surgical
elimination of the infectious source by means of a rational and risk-adapted
operative procedure. Other technical procedures (such as intra- and postoperative
lavage, drainage of the abdominal cavity, decompression, etc.) are critically
reviewed and reduced to the scientific background. A calculated antibiotic
therapy should be performed to eliminate the leading pathogens. The golden
standard seems to be the short-term application of a third generation
cephalosporin in combination with metronidazole. Antibiotic-induced
endotoxinemia, bacterial shifting to grampositive species, and escalating
antibiotic resistance require the examination of new therapeutic regimens (e.g.
with quinolones).
PMID- 10670112
TI - [Prophylaxis and therapy of infectious complications of lung surgery].
AB - Postoperative infections are a dreaded complication in pulmonal surgery. Besides
the optimal preparation of the patients and careful operative technique,
perioperative antibiotic prophylaxis represents an important factor in avoiding
infectious consequences. Owing particularly to the high proportion of patients
with malignant, consumptious illnesses in thorax surgery, immune deficiencies
must be reckoned with in this group of patients. The spectrum of germs to be
expected within the framework of pulmonal surgery determines to some extent which
antibiotic shall be used. We have investigated the efficacy of a standardized
antibiotic prophylaxis using cefotaxime (Claforan) in 200 pulmonal patients.
Pleural empyema is a rare, but nonetheless important infectious illness, as a
consequence of pulmonal operations, or also following pneumonia. Whilst the early
stages of an empyema can often be successfully treated using only drainage
treatment, chronic empyema usually requires a thoracotomy with empyema dissection
and excortication, as well as subsequent irrigation-suction drainage treatment.
In spite of specific surgical sanitation and irrigation-suction drainage
treatment, therapy is often complicated by persistent germs in the thoracic
cavity. Instillation therapy with taurolidine can lead to faster healing of the
infection in such cases. Purulent mediastinitis is an extremely rare illness, but
dreaded owing to its high mortality. The causes of the illness lie in injuries of
the trachea, of the bronchial tubes, and of the oesophagus. With the introduction
of medial sternotomy as operative entry, mediastinitis as a postoperative
complication has increased noticeably in frequency. Mediastinitis occurs as a
descending infection as a consequence of odontogenic affections. Owing to
frequently late diagnosis, infection is usually advanced, so that simple drainage
treatment of the mediastinum no longer suffices in many cases. We introduce our
concept of treatment using our own patient collective.
PMID- 10670113
TI - The role of NMDA antagonist in perioperative pain management.
PMID- 10670114
TI - Comparison of rocuronium and vecuronium pretreatment for prevention of
fasciculations, myalgia and biochemical changes following succinylcholine
administration.
AB - BACKGROUND: The purpose of this study was to assess the effect of rocuronium
pretreatment on the succinylcholine-induced fasciculations, myalgia and
biochemical changes, and to compare it with vecuronium pretreatment. METHODS: We
have studied 60 female patients undergoing minor elective surgery, in a
prospective double blinded method. Three groups of 20 patients each was
pretreated with either saline (control group), rocuronium 0.05 mg/kg (rocuronium
group) or vecuronium 0.007 mg/kg (vecuronium group). Three min after the
pretreatment, 1.5 mg/kg succinylcholine was injected. Single twitch responses to
electrical stimulation were measured. Serum potassium and creatine kinase were
respectively measured 5 min after succinylcholine and 24 h after operation.
Fasciculations and myalgia on postoperative day 1 and day 2 were evaluated.
RESULTS: The incidence of fasciculations was lowest in the rocuronium group,
followed by the vecuronium group, and was highest in the control group. The
incidence of myalgia on postoperative day 1 was lower in the rocuronium and
vecuronium groups than the control group. The increase of serum creatine kinase
was similar among the three groups, but there was no increase in serum potassium
concentration in any group. No differences of the single twitch responses to
electrical stimulation were found between the rocuronium and vecuronium groups.
CONCLUSIONS: Rocuronium pretreatment was more effective in reducing
fasciculations than was vecuronium pretreatment, but both were equally effective
in preventing myalgia on postoperative day 1. This difference may reflect the
differential activities of rocuronium and vecuronium at the neuromuscular
junction. The increase of creatine kinase was not attenuated by any regimen.
PMID- 10670115
TI - Postoperative intramuscular dextromethorphan injection provides postoperative
pain relief and decreases opioid requirement after hemorrhoidectomy.
AB - BACKGROUND: Previous studies have shown that dextromethorphan (DM) produces an
analgesic/antihyperalgesic effect. This study was designed to examine whether
postoperative DM intramuscular (i.m.) injection could reduce post
hemorrhoidectomy pain. METHODS: At the end of the surgery, patients in the study
group (n = 30) were given an intramuscular injection of 40 mg DM and 20 mg
chlorpheniramine (CPM) while in the study group (n = 30), the patients were given
intramuscular 20 mg CPM only. Pethidine (1 mg/kg, i.m.) was prescribed for
postoperative pain relief if required. The time to first pethidine injection,
total pethidine consumption, worst pain score, and pethidine-related side effects
were recorded for 48 h postoperatively. RESULTS: The time from the end of
operation to the first pethidine injection was 5.4 +/- 1.6 h and 17.8 +/- 3.7 h
(P = 0.006) in the control group and the study group, respectively. Total
pethidine consumption was 139.5 +/- 11.5 mg and 77.5 +/- 12.2 mg (P < 0.001) in
the control group and the study group, respectively. The worst VAS score was 7.5
+/- 0.2 and 7.1 +/- 0.2 (P = 0.09) in the control and the study groups,
respectively. The number of patients who required pethidine injection was 29 and
21 (P < 0.005) in the control and the study groups, respectively. The number of
patients who suffered pethidine-related side effects was 7 and 1 (P < 0.025) in
the control and the study groups, respectively. CONCLUSIONS: We found that
intramuscular DM given at the end of operation could provide good postoperative
pain relief and decrease the pethidine requirement after hemorrhoidectomy.
PMID- 10670116
TI - Is sedation necessary for demented patients under infiltration anesthesia?
AB - BACKGROUND: Sedation for intraoperative patients under infiltration anesthesia is
often used, however, disadvantages of sedation for demented patients may
sometimes exceed its advantages because some of the demented patients are already
apathetic about their surroundings. The authors prospectively investigated
whether sedation for alert or demented patients receiving surgery under
infiltration anesthesia is useful and safe for intraoperative management.
METHODS: Sixty patients undergoing irrigation and drainage of chronic subdural
hematoma under infiltration anesthesia were divided into four groups. Patients in
Group A were non-sedated alert patients. Patients in Group B were non-sedated
demented patients. Patients in Group C were sedated alert patients. Patients in
Group D were sedated demented patients. Intraoperative variables, adverse
effects, and the postoperative satisfaction represented by five-point score were
recorded. RESULTS: The heart rate in group A during operation was significantly
faster than the control value. The postoperative satisfaction score in group A
was significantly lower than any other groups. A patient in group D required a
nasal airway to improve respiration during operation. CONCLUSIONS: These results
suggest that there is no evidence to show that advantages of sedation for
demented surgical patients under infiltration anesthesia excel the disadvantages
although sedation for alert patients may be an effective and rational conduct in
intraoperative management.
PMID- 10670117
TI - The effects of tramadol versus fentanyl in attenuating hemodynamic response
following tracheal intubation.
AB - BACKGROUND: Tramadol is a novel central acting analgesic. It has been used as a
complement to general anesthesia and an effective agent for postoperative
analgesia. However, the influence of tramadol on the hemodynamic response
following laryngoscopy and tracheal intubation is less known. METHODS: Forty
patients of both sexes, 16-50 year old, ASA physical status I or II, scheduled
for elective surgery were randomly divided into equal groups in this prospective,
double blind study. After obtaining the baseline data, the patient was given 3
micrograms/kg fentanyl (Group F) or 3 mg/kg tramadol (Group T). Then induction of
anesthesia in a uniform and standardized manner was carried out by an
anesthesiologist who was blind to the medication. The hemodynamic parameters were
measured and recorded immediately after induction but prior to laryngoscopy, 3,
6, and 9 min after intubation, and before incision. We also observed any unusual
effect in the postoperative care unit. Chi-square test, Student's t-test and
paired t-test were used for statistical comparison. A P less than 0.05 was
considered statistically significant. RESULTS: All patients had a successful
induction and intubation. Differences in baseline values were not significant,
nor were the differences in the values following induction. After laryngoscopy
and intubation, heart rate increased significantly above the baseline level in
both groups. The increase of heart rate was significantly more at 6 and 9 min (P
< 0.05) and lasted longer in the tramadol group. After intubation, systolic, mean
and diastolic arterial pressure (SAP, MAP, DAP) increased significantly above
baseline in both groups too, except for DAP in fentanyl group. At 6 and 9 min,
the MAP and DAP were significantly higher in tramadol than in fentanyl group (P <
0.05). Six patients in tramadol group had mild pain on injection of tramadol.
CONCLUSIONS: When administered right before thiopental induction, 3 mg/kg
tramadol did not display a better attenuation against the increase of hemodynamic
profiles than did 3 micrograms/kg fentanyl following tracheal intubation.
PMID- 10670118
TI - New frontiers in mechanisms and therapy of painful peripheral neuropathies.
AB - Ten years ago we had no more than informed speculations about the pathogenesis of
neuropathic pain, and our ability to give these patients relief was so limited
that neuroablative therapy or even deep brain stimulation via an implanted
electrode was often the only hope. We now have a thorough emperically based,
although undoubtedly still incomplete, understanding of the pathophysiology.
Moreover, we have discovered new classes of drugs that specifically relieve
neuropathic pain. It is not unreasonable to hope that in the near future patients
with painful peripheral neuropathy will never again have to suffer unrelieved
pain.
PMID- 10670119
TI - Acute fatal vasoplegia and asystole induced by intravenous amiodarone after
cardiopulmonary bypass in a patient with preoperative cardiogenic shock.
AB - Single dose intravenous amiodarone has been widely used and shown to be effective
to treat supraventricular and ventricular arrhythemias in cardiac surgery. We,
herein, report a 60-year-old female patient, sustaining cardiogenic shock in the
course of percutaneous transluminal coronary angioplasty (PTCA) for unstable
angina unrelieved by medication including nitroglycerin, succumbed to a life
saving emergent coronary artery bypass grafting (CABG) operation at the end of
cardiopulmonary bypass (CPB) following a 180 mg bolus dose of amiodarone (3
mg/kg) directed at the ventricular arrhythmias, triggered by protamine and
unresponsive to lidocaine treatment. Amiodaroneinduced asystole and vasoplegia
were thought to be the causation of the failure of resuscitation. The causes of
the development of these complications, the potential hazards of its use and the
management relative to the consequential complications are reviewed and
discussed.
PMID- 10670120
TI - Postoperative myocardial infarction in a patient with perioperative ST-depression
-a case report.
AB - Often we ignore electrocardiogram (EKG) evidence of ischemia and no adverse
events occur. However, once in a while these ischemic episodes will turn into a
full-blown myocardial infarction. Therefore, studying perioperative events which
tilt the balance over to postoperative myocardial infarction (PMI) can enlighten
our knowledge in postoperative myocardial infarction (MI) prevention. We present
a case of ST depression in perioperative EKG evolving into postoperative MI. In
this paper we attempt to explore various possibilities which could have altered
this patient from her ischemic state into an infracted event.
PMID- 10670121
TI - Postoperative right atrial and pulmonary embolism after prolonged spinal surgery.
AB - Perioperative pulmonary thromboembolism can proceed rapidly with grave prognosis,
in which immediate or accurate diagnosis and management is not easy. According to
the literatures, patients receiving spinal surgery are at relatively lower risk
of developing thromboembolism. We would like to present a case of postoperative
pulmonary thromboembolism which developed after a prolonged lumbar spinal
surgery. Tachycardia and unstable hemodynamics were noted postoperatively.
Pulmonary and right atrial thrombi were disclosed by transesophageal
echocardiography. Although cardiotomy and thrombectomy were immediately
performed, the patient finally died 3 days after the operation. The pathogenesis
of venous thromboembolism (VTE) in the surgical patients, the risk factors which
predispose a patient to VTE, diagnosis, and treatment as well as the prophylactic
measures of VTE are herein reviewed and discussed.
PMID- 10670122
TI - Unilateral vocal cord paralysis following endotracheal intubation--a case report.
AB - A 41-year-old man of ASA physical status class I was scheduled to receive the
video-assisted thoracoscopic T2 sympathectomy for hyperhidrosis palmaris. The
elective surgery was performed smoothly under general anesthesia with
endotracheal intubation. However, the patient complained of hoarseness in the
postoperative period. A stroboscopic examination showed that the left vocal cord
remained stationary in the paramedian position, signifying left vocal cord
paralysis. In the case, we believed it was most likely that endotracheal
intubation might be responsible for the unilateral vocal cord paralysis. The
possible cause was that during placement or thereafter during positioning, the
endotracheal tube was malposed or slipped upward, rendering its inflated cuff to
rest against the vocal cords. Another reason was that the cuff which was over
inflated made the vocal cords under constant pressure. Both conditions may cause
damage to the anterior branch of the recurrent laryngeal nerve. We also discussed
the general management and prophylaxis for the unilateral vocal cord paralysis.
PMID- 10670123
TI - [Immunohistochemistry applied to urology].
PMID- 10670124
TI - [Radical prostatectomy in clinically localized prostatic adenocarcinoma. Study of
patients with positive margins and their impact on survival free from biochemical
progression].
AB - OBJECTIVES: Margins involvement in T1-T2 patients undergoing radical
prostatectomy is a negative prognostic factor. We aimed to: a) Study the clinical
and pathological features of patients with surgical margins involvement; b)
Elucidate the influence of margins involvement on the progression-free survival.
MATERIAL AND METHOD: The study included the group with "positive margins" out of
a series of 160 patients with localised prostate adenocarcinoma who underwent
radical prostatectomy at the Clinica Universitaria de Navarra between 1988-1997.
statistics used: Fisher's or Pearson's test for qualitative variables. Kaplan
Meyer, Log-rank and Cox's multivariate tests for the survival study. RESULTS: The
group accounts for 28% (45/158) of all patients undergoing radical prostatectomy.
Mean PSA (22 +/- 14 ng/ml) is similar to the remaining group although there is
greater significant rates of PSA > 15 ng/ml (p: 0.006), worse Gleason (p: 0.01),
higher proportion of T2bc (p: 0.003) and node involvement (0.001). Progression
free survival (BPFS) is significantly lower in this group (32 +/- 12% vs 61 +/-
6% at 5 years). Margins are the single factor with higher influence (RR:5) in the
multivariate study. Influence is clear in patients with Gleason < 5 (0% vs 87%)
and PSA < 30 ng/ml (33 +/- 14 vs 70 +/- 7%), but has no influence on BPFS of
patients with PSA > 30 ng/ml or Gleason 5-10. CONCLUSIONS: Positive margins in
patients undergoing radical prostatectomy is associated to higher PSA, worse
Gleason and higher stage. They are the most significant independent risk factor
(except for PSA > 30 ng/ml) for biochemical progression-free survival as
evidenced in the multivariate study, although it is likely this influence is
diluted in patients with PSA > 30 ng/ml and/or Gleason 5-10.
PMID- 10670125
TI - [Randomized prospective study comparing BCG and BCG plus oral tegafur in the
prevention of stage T1 superficial tumors of the bladder. Results after 2.5
years].
AB - We present our experience in eighty patients with superficial bladder cancer
stage T1. They have been randomized to receive BCG 27 mg weekly x 6 and monthly
until complete one year (Group A) or the same schedule plus Tegafur 800 mg daily
until complete one year. Results are similar in both groups. With a median follow
up of two years and a half, 33% in Group A and 20% in Group B have had
recurrence; 7.6% in group A and 3% in group B have had progression in stage.
Differences are not significant in both cases. Tolerance of Tegafur is good with
only 11% of secondary effects. We concluded that there are no differences in both
treatments but there is a trend to better results with combinant therapy. It is
necessary more patients to achieve definitive results.
PMID- 10670126
TI - [Incidental prostatic cancer].
AB - OBJECTIVE: To evaluate the incidence of incidental prostate cancer and PSA
ability to predict its presence. MATERIAL AND METHOD: Retrospective study of 862
patients undergoing prostate surgery between 1994 and 1997, both inclusive.
Digital rectal examination provided no suspicion of neoformation. Mean age was 68
+/- 7.5 years. Mean PSA, 8.3 +/- 10 ng/ml (Hybritech). 15% patients had
previously undergone at least one ultrasound-guided biopsy in the peripheral
area. 55% patients underwent retropubic surgery and the remaining 45% prostate
transurethral resection. Ultrasound prostate volume for both patient groups was
107 +/- 63 cc and 45 +/- 25 cc, respectively. RESULTS: Incidental cancer was
found in 6% patients; 65% were T1a and 35% T1b. Mean PSA concentration in cancer
patients was almost significantly (p = 0.05) higher than in patients with BPH.
Patients with PSA > 10 ng/ml presented a significantly higher incidence of cancer
(p = 0.02). Patients with previous prostate biopsy showed a cancer incidence rate
of 12% versus 5% patients with no previous biopsy (p = 0.001). CONCLUSIONS:
Incidence of incidental prostate cancer was 6%. PSA was not a good predictor of
incidental cancer. Patients with PSA > 10 ng/ml, showed higher incidence of
cancer. Younger patients with PSA > 10 ng/ml, and at least one negative biopsy of
the peripheral area should undergo biopsy of the transitional area prior to
surgery.
PMID- 10670127
TI - [Bone abnormalities. Muscular dystrophy and lithiasis: lithogenic factors and
therapeutic difficulties].
AB - Duchenne's muscular dystrophy with kypho-scoliosis, progressive muscle weakness
and abnormal fatigue of the muscles results in an immobilisation syndrome with
increased bone resorption and hypercalciuria. The accompanying chest deformity
alters the respiratory capacity, causing pulmonary insufficiency, acidosis and
acid urine. Dorso-lumbar kypho-scoliosis, occasionally very serious, alters the
status of the upper urinary tract affecting urine transportation (stasis). Thus,
hypercalciuria, urinary acidosis, stasis and infection will determine the
formation of urinary lithiasis that can take place in these patients. MATERIAL
AND METHODS: 15 patients with a variety of myopathies (Duchenne's disease,
Myasthenia gravis,...) or serious skeletal deformities with metabolic renal
lithiasis (pyelic or calyceal) were seen by our group. Other patients presented
post-traumatic (paraplegia, hemiplegia,...) or poliomyelitic skeletal sequels or
Pott's disease, with septic lithiasis. After evaluating all likely approaches
including ESWL, the latter was chosen being the least aggressive. Conventional
surgery, either percutaneous or endoscopic, foretells technical problems in terms
of lithiasis approach. Both the case introducing the subject, Duchenne's muscular
dystrophy, with bilateral renal lithiasis and the others are a reflection of
complexity of finding the righ approach for these patients, including ESWL.
RESULTS: Scoliosis was not a technical obstacle, since patients could be placed
in lateral/oblique position to situate the stone in the right spot for
lithotrity. Debris removal was easy, with no obstructive complications, in spite
of the significant immobilisation of these patients. CONCLUSION: Immobilisation
syndrome, acidosis, stasis and infection could jointly determine the lithogenesis
mechanism in patients with muscle diseases or serious skeletal deformities and
with renal lithiasis. ESWL has an opportunity in serious cases, where other
techniques including surgery have major difficulties.
PMID- 10670128
TI - [Our clinical experience with the use of ++sildenafil citrate to treat erectile
dysfunction].
AB - OBJECTIVE: To evaluate the response and adverse effects to treatment with
Sildenefil in those patients with an erectile dysfunction who, according to our
protocol, were considered as candidates for this therapeutic option. MATERIALS
AND METHODS: We reviewed the clinical histories of 180 patients seen in our
service from november 1988 to February 1999 as a result of an erectile
dysfunction. Those patients in whom the use of Sildenefil was not contraindicated
were prescribed this product at does of 50 mg. The response to treatment was
subjectively evaluated based on the option of the patient when comparing his
quality of life before and after treatment. RESULTS: Out of 180 patients, 144
started treatment as indicated. Of these, 67% expressed a positive response,
while 33% did not respond to treatment. Adverse effects were notice by 26% of
patients, but in 97% of them they were not severe enough to withdraw the
medication. CONCLUSIONS: Two-thirds of 144 patients with erectile dysfunctions of
heterogeneous origin responded positively to treatment with Sildenefil. One
fourth of them reported some ort of adverse effect, but almost none of them
stopped the medication for this reason.
PMID- 10670129
TI - [Impact of transplantectomy of the first graft on the clinical course of cadaver
renal retransplantation].
AB - PURPOSE: At the present time a number of prediction factors on the outcome of
second cadaver renal transplants are known, in particular the influence of
recipient response to the first graft. However, we do not know if retaining or
removing the non-functioning organ has any repercussion on subsequent
transplants. This is the object of the present study. MATERIAL AND METHODS: A
retrospective study was carried out on the clinical records of 80 patients who
had undergone a second cadaver renal transplant under CyA between 1985-1995 at
Hospital 12 de Octubre. Data on the characteristics and outcome of the first and
second transplants were collected, plus those concerning the recipient and donor.
These variables were used to construct a multivariant analysis model of graft
survival. The nephrectomy of the non-functioning graft was only carried out when
absolutely necessary (n = 58). RESULTS: The multivariant analysis showed that the
nephrectomy of the non functioning graft did not modify the risk of recipient
sensitization or the probability of developing acute or chronic rejection of the
second graft. However, it reduced the risk of losing this second graft at medium
or long term significantly (p = 0.009). CONCLUSIONS: These data constitute the
first solid argument in favor of elective nephrectomy in candidates for a second
cadaver renal transplant. Nevertheless, a more thorough study should be carried
out of the immunological mechanism involved before recommending this as a general
procedure.
PMID- 10670130
TI - [Meningeal carcinomatosis in bladder tumor].
AB - We report a strange case of a bladder whose first metastasic manifestation, after
two years of the diagnosis, was a peripheric polyneuropathia. This patient was
treated with immunotherapy with BCG for superficial carcinoma of the bladder
during one year. Gradually central neurological symptoms appeared and the patient
died one month later. A meningeal carcinomatosis was identify as the cause. No
bone metastases existed, which is the most frequent way of tumours extension
towards leptomeninges. We argue about the way to arrive at meninges.
PMID- 10670131
TI - [Report of a new case of small-cell carcinoma of the bladder and review of the
literature].
AB - We report a case of small cell carcinoma of the urinary bladder in 71-year-old
male patient. Oat cell of the urinary bladder is extremely uncommon, and up to
date only 135 cases have been reported in word literature. Histologic,
microscopic, and immunohistochemical characteristics are similar to oat cell
carcinoma of the lung and other extrapulmonary oat cell carcinomas. We conclude
this report with immunohistochemical study with PGP 9.5, neuron-specific enolase
a synaptophisine.
PMID- 10670133
TI - [Encrusted alkaline cystitis and malacoplakia].
AB - Urinary infection due to urea splitting bacteria leads to a rise in urinary pH,
favouring the precipitation of calcium salts and struvita crystals. If deposited
on the surface of a bladder with chronic inflammation or some other previous
lesion, may produce an alkaline encrusted cystitis, now a rare condition. In the
case here presented, occurred in a 69-year-old male. Corynebacterium urealyticum
grown in the urine, and some foci of malakoplakia were found in the area of
encrustation endoscopically excised. This case seems to be the third example of
alkaline encrusted cystitis associated with malakoplakia reported in the
bibliography. These two conditions share similar clinical signs and may probably
have a common aetiopathogenesis.
PMID- 10670132
TI - [Extragonadal germ cell tumor with "burned-out" phenomenon in the testis].
AB - The "burned-out" phenomenon in germ-cell neoplasias is defined by the presence of
an extragonadal germ-cell tumour with no tumour at the testis level where a
series of distinctive histological lesions can be detected indicative of the
earlier presence of an already disappeared testicle tumoration. Extragonadal germ
cell tumours with "burned-out" phenomenon show better evolution than their
primary counterparts and are treated similarly to primary tumours of the testis.
Currently, in the presence of retroperitoneal tumoration, a scrotal ultrasound
study with high frequency transducers can lead to a suspected picture of tumoral
involution. This paper contributes one retroperitoneal seminoma with "burned-out"
phenomenon in the homolateral testis in a 35-year old patient. Available clinical
and radiological criteria were enough to reach a suspected diagnosis. Homolateral
orchiectomy and biopsy of retroperitoneal tumoration were performed, rounding
treatment up with polychemotherapy. Evolution was good with immediate complete
response.
PMID- 10670134
TI - [Ask-Upmark kidney: description of a case and review of the literature].
AB - We present a 15-year-old male patient diagnosed histopathologically as suffering
from Ask-Upmark kidney, in the absence of vesicoureteral reflux and with
hypertension. The first clinical manifestation was completely atypical: right
loin pain, with so many agudisation treated at our emergency serve that justified
a thorough study. The pathogenesis of the Ask-Upmark kidney is still unknown;
some authors defend the congenital malformation hypothesis, as it was first
described in 1929, but there are groups who support the Ask-Upmark kidney as a
form of reflux nephropathy. After our description we present a review of the
literature.
PMID- 10670135
TI - [Acute urologic symptoms associated with uterine myoma].
AB - While prevalence of uterine leiomyoma is high, its presentation affecting the
urinary tract is uncommon. We contribute the cases of two adult women with
symptoms of nephritic colic and urinary retention. Etiology was acute obstruction
of the urinary tract due to previously asymptomatic urine myomas. Management in
both patients was surgery, using hysterectomy to resolve the urinary obstruction.
A brief review of the literature is included.
PMID- 10670136
TI - [Tuberculous orchiepididymitis as clinical onset of human immunodeficiency virus
(HIV) infection].
AB - The emergence of acquired immunodeficiency syndrome has changed the natural
history of tuberculosis which has now become the second most common infection
associated to human immunodeficiency virus infection. It is only rarely that a
tuberculous infection has an urogenital location, and extrapulmonary locations
are generally related to severe immunosuppression. This paper presents one case
of tuberculous orchitis that presented as the clinical onset of acquired
immunodeficiency syndrome. Discussion of the clinical evolution and the
therapeutic approach that consisted in orchiectomy associated to treatment with
tuberculostatics.
PMID- 10670137
TI - [Penile fracture involving cavernous bodies and urethra].
AB - Reports on fracture of the penis are scarce in the spanish urological literature
and in most cases injury appear limited to the corpora cavernosa. In this report
a case of rupture of both corpora cavernosa and the urethra during sexual
intercourse is presented. Early surgical treatment rendered good results. A
literature review on currently recommended diagnostic and treatment practices is
presented.
PMID- 10670138
TI - [Hemorrhaging eso-gastro-duodenal ulcers: epidemiology and management. A
multicenter prospective study].
AB - The aim of this study was to estimate the incidence, and to describe the
characteristics and medical care in patients with bleeding upper gastrointestinal
ulcers in the general population. PATIENTS AND METHODS: A study was performed
over six months in 1996 in 4 French geographical areas: Finistere, Gironde, Seine
Maritime, and the Somme (3 million people minimum 18 years). All public or
private hospitals, and specialist gastroenterologists in private practice
participated in the study, based on a standardized questionnaire. RESULTS: Over 6
months 793 patients with bleeding ulcers were identified, corresponding to 27 per
100,000 inh./year or 24,000 cases in France. Most patients were men (60%) and
40.1% were 75 years and older. The ulcer was oesophageal (6%), gastric (47%), or
duodenal (69%). In 406 patients (51.2%) a chronic disease was present (cancer,
cirrhosis, circulatory, respiratory or cardiac disease). In 237 cases (29.9%) the
ulcer occurred in patients, 453 patients (57.1%) were admitted and 103 patients
(13%) were managed as outpatients. Gastrotoxic drugs were taken by 349 patients
(44%): non steroidal anti-inflammatory drugs (18.7%), aspirin (21.2%, including
2/3 with doses under 330 mg/day), corticosteroids (7.8%) and 24.3% had
anticoagulant therapy. Patients were managed in university hospitals (39.3%),
other public or non profit hospitals (44.2%) or private hospital (16.5%) with
geographical differences between the 4 areas. Therapeutic endoscopy was performed
in 16.9% and a surgical procedure was performed in 5.9%. The mortality rate
(outpatients excluded) was 13.5% (n = 93), but only 2% (n = 16) of death were
associated with a bleeding ulcer: mortality was higher in inpatients (24.1%) than
in out patients (8.1%). A chronic disease was also associated with higher
mortality (17.9% versus 8.1%). CONCLUSION: Bleeding ulcers are frequent and
severe, especially in inpatients or associated with chronic conditions. A
gastrotoxic drug used is found in about fifty percent of the cases.
PMID- 10670139
TI - [Results and indications of lateral ileostomy functionally terminated in
colorectal surgery].
AB - Loop ileostomy (LI) ensures fecal diversion to protect an anastomosis or anatomic
colorectal or ano-perineal damage. The aim of this retrospective study was to
evaluate loop ileostomy morbidity in emergency and planned colorectal surgery.
PATIENTS AND METHODS: From 1991 to 1996, 145 loop ileostomies were performed in
139 patients, 77 men and 62 women with a mean age of 48.7 years (15-82). The
etiology was a rectal tumor (cancer or large villous tumor n = 47), inflammatory
bowel disease (n = 47, ulcerative colitis = 37 and Crohn's disease = 10) Familial
Adenomatous Polyposis (n = 13) and other diseases (n = 32). 80% LI (n = 116)
protected ileo-anal anastomoses (n = 46) colo-anal anastomoses (n = 45, 26 with
colonic pouch), ileo-rectal anastomoses (n = 11) and other anastomoses (n = 15).
20% LI (n = 29) dysfunctional ano-perineal lesions (n = 8), anastomosis leak (n =
4) or distal bowel without intestinal resection (n = 17). RESULTS: 7 deaths were
not stoma-related. 91% LI were closed after a mean diversion time of 3.6 months.
LI closure was performed by a parastomal (n = 128) or laparotomy procedure (n =
4). Morbidity during LI diversion was observed in 24 patients (16.5%) 12 of whom
(8.3%) were operated for small bowel obstruction (n = 6; 4.2%) stoma revision (n
= 5; 3.5%) and prolapse (n = 1; 0.7%). 2 patients had peristomal skin
excoriations, and 5 patients required readmission for dehydration due to high LI
output. Morbidity after LI closure was observed in 12 patients (8.6%) 5 of whom
were operated for anastomotic leak (n = 4) or small bowel obstruction (n = 1).
Low morbidity and defunctioning efficiency confirm the indications for LI. LI is
our first-line stoma in planned or emergency colorectal surgery.
PMID- 10670140
TI - [Regulatory aspects of disinfection of endoscopes].
AB - The circular on the sterilization and the law of july 1, 1998 enact clearly that
the medical devices that support steam sterilization must be sterilized with an
organization of sterilization that ensure quality. Endoscope that enter normally
sterile tissues should be subjected to a sterilization procedure before each use;
if this is not feasible, they should receive high-level disinfection to destroy
bacterial spores. The endoscope must be immersed for at least one hour in aqueous
solution of 2% glutaraldehyde. This lengthened duration of processing must be
integrate in the organization of medical department. The endoscopes not
penetrating in a sterile cavity are disinfected with manual processing according
to the protocol of the circular of april 1996, or with automated endoscope
reprocessing machine. The different types of automated machine used to wash and
disinfect endoscope must now answer to criterion concerning their design
described in the circular of july 15, 1998. A significant work has to be made in
hospitals to conform automated machine and procedure, to control the risk
dependent with their use.
PMID- 10670141
TI - [Traceability of sterilizable medical devices].
AB - Device traceability means recording and storing of data collected during the
various steps of reprocessing of medical devices. We describe the purpose and
methods to achieve device traceability.
PMID- 10670142
TI - [Role of surgery in the treatment of refractory ascites in cirrhotic patients].
AB - Ascites, generally directly reflecting portal hypertension, is the commonest
cause of hospitalisation in patients with cirrhosis. In almost 10% of patients
with ascites, optimal medical treatment combining bed rest, salt and water
restriction, and diuretic treatment, is unable to induce sodium excretion and
decrease the volume of the ascites, corresponding to the definition of refractory
ascites. In other cases, it is the treatment of ascites itself (salt and water
restriction and diuretics) which induce complications: water and electrolyte
disturbances, functional renal failure, encephalopathy, the development of which
also corresponds to refractory ascites. The therapeutic armamentarium for the
management of refractory ascites remains varied, with the use of aspiration of
ascites with compensation, peritoneovenous shunts, transhepatic or surgical porto
systemic anastomoses, and finally, liver transplantation. At the present time,
each therapeutic measure must be taken while keeping in mind the possibility of
subsequent liver transplantation and the potential risk of compromising liver
transplantation by inappropriate treatments. In this context, the authors review
and analyse the respective places of the various therapeutic modalities in the
management of refractory ascites in cirrhotic patients.
PMID- 10670143
TI - [Colorectal surgery].
PMID- 10670144
TI - [Hereditary colorectal cancer without associated polyadenomatosis].
AB - Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant
condition in which affected individuals develop colorectal cancer or extracolonic
cancer, most commonly endometrial, at an early age. Recent advances in molecular
genetics have led to the identification of a germline mutation of DNA mismatch
repair genes to be responsible for the majority of HNPPC cases. Since clinical
screening of gene carriers can help to prevent cancer, it is important to devise
strategies applicable to this syndrome. Recommendations for current management,
especially screening and surgical treatment are under study, as they have not yet
been clearly established. This paper reviews the clinical presentation, the
molecular genetic diagnosis and therapeutic approaches of this syndrome including
the controversies concerning prophylactic colectomy for cancer or gene carriers.
PMID- 10670145
TI - [Hereditary colorectal cancer associated with polyposis syndromes].
AB - This study reviews different aspects of hereditary colorectal cancer associated
with three polyposis syndromes: familial adenomatous polyposis, juvenile
polyposis coli and Peutz-Jeghers syndrome. All these syndromes share some
similarities: low incidence, autosomal dominant inheritance, genetic
predisposition to colorectal cancer and/or other extracolonic cancers. Classical
familial adenomatous polyposis is clinically defined by the presence of hundreds
of adenomatous polyps in the colon and rectum, whereas less than 100 polyps are
found in attenuated familial adenomatous polyposis. Without prophylactic
colectomy, colorectal cancer develops inevitably by the age of 40. Restorative
proctocolectomy with ileal anal-pouch anastomosis is the operation of choice in
familial adenomatous polyposis. In juvenile polyposis coli, 50-200 hamartomatous
polyps are found in the colon, rectum, stomach and small bowel. Life-time
cumulative risk for colorectal cancer is estimated to be 50%. Prophylactic
colectomy is required only in cases in which endoscopic surveillance is not able
to control polyp development. Hereditary mixed polyposis syndrome is a variant
form of juvenile polyposis coli, consisting of multiple mixed adenomatous,
hyperplastic and hamartomatous polyps. Peutz-Jeghers syndrome is characterized by
multiple hamartomatous polyps located in the small bowel, colon and stomach.
Small bowel follow through and colonoscopy is advised for surveillance. Surgery
is warranted only in cases of polyps larger than 1 cm. The causative genes of
these syndromes have been cloned. Molecular genetic testing of affected and at
risk individuals is proposed in order to advise surveillance and management.
PMID- 10670146
TI - [Surgical anatomy of pelvic nerves].
AB - A good knowledge of the anatomy of the mesorectum and pelvic autonomic nerves
allows the colorectal surgeon to reconcile both oncologic and functional results
in rectal cancer excision. The author describes the anatomy of the systemic and
autonomic pelvic nerves and describes techniques designed to avoid nerve damage
during rectal cancer excision.
PMID- 10670147
TI - [Surgery of rectal cancer: total exeresis of the mesorectum].
AB - The authors review the recent literature about total mesorectal excision for
rectal cancer. They report the actual management of such patients.
PMID- 10670148
TI - Total mesorectal excision with autonomic nerve preservation: a new foundation for
the evaluation of multi-disciplinary adjuvant therapy in the management of rectal
cancers.
AB - Local and distant recurrence rates and disease-free and overall survival are
markedly improved by total mesorectal excision, with little increase in
morbidity, compared with other techniques of resection of rectal cancer. Adjuvant
therapy is associated with significant morbidity and initial results suggest it
may not be beneficial in the aggregate. Adjuvant therapy must be re-evaluated in
trials using TME as standard operative technique. Different subgroups of
patients, defined by clinical and pathological criteria will be best served by
different forms of therapy and should be studied based on rates of local and
distant recurrence. Selected groups of patients will be best served by undergoing
no adjuvant therapy of any kind.
PMID- 10670149
TI - [Preoperative radiotherapy of rectal cancer. The Lyons experience, 1985-1996.
Prognostic study apropos of 312 patients].
AB - AIM OF STUDY: Preoperative radiotherapy is used increasingly in rectal cancer in
Europe. This study is a retrospective analysis of a series of 312 patients with
rectal adenocarcinoma treated by preoperative radiotherapy. MATERIAL AND METHOD:
From 1985 to 1996, 312 patients were included in this study. Preoperative staging
was: T2: 83, T3: 192 et T4: 21. On digital rectal examination, 25 patients were
classified as N1. Endorectal sonographic staging was: uT1: 3, uT2: 77, uT3: 163,
uN0: 122, uN1-2: 127. After surgery, pathological staging was: pT0: 43 (14%), pT1
24, pT2: 81, pT3: 151, pN0: 229, pN1-2: 81. Radiotherapy was delivered to the
posterior pelvis with an accelerated schedule 39 Gy/13 fractions/17 days with x
18 MV. RESULTS: Median follow-up is 54 months. For pM0 patients (297 patients),
the overall 5-year survival rate is 67%. Local failure rate is 9%. Since 1986,
the rate of sphincter saving surgery is close to 65%. Various parameters related
to the tumor were found to be significant prognostic factors on multivariate
analysis in relation to 5-year overall survival rate: the T stage as judged by
digital rectal examination and endorectal sonography, the N stage as evaluated on
digital rectal examination but not with endorectal sonography. Pathological
examination of the operative specimen retains a very strong prognostic value for
pT and pN. CONCLUSION: Pathological examination of the specimen of rectal
carcinoma retains a very strong prognostic value after preoperative radiation
therapy. Endorectal sonography is of interest to evaluate T staging of the tumor
but is not reliable for N stage.
PMID- 10670150
TI - [Established data and practical recommendations concerning pre- and postoperative
chemotherapy of rectal cancer].
AB - Adjuvant chemotherapy appears to be active in stage II-III rectal cancers; the
NSAPB R01 trial demonstrated a survival advantage for patients receiving
chemotherapy using the MOF protocol and 3 meta-analyses are in favor of the
efficacy of adjuvant chemotherapy in rectal cancer. Three randomized trials have
also demonstrated that combinations of radiation and chemotherapy are superior to
surgery alone or adjuvant radiotherapy and demonstrated the major role of
systemic chemotherapy combined with radiotherapy. However this efficacy of
adjuvant chemotherapy alone or combined with radiation therapy is still debated
and specific trials must be conducted to test the value of chemotherapy using
more active regimens than those previously tested and taking into account the
quality of surgery and radiotherapy; such trials are in progress, especially the
trial conducted by the EORTC and the FFCD. The efficacy of neoadjuvant
chemotherapy has never been clearly demonstrated, although a combination of
radiotherapy and chemotherapy as first-line treatment for locally advanced rectal
cancer and in the case of synchronous metastasis seems to facilitate surgical
resection. It is a reasonable and tolerable approach with manageable toxicity
which gives substantial results in 2/3 of patients. This strategy also allows
better selection of patients likely to benefit from surgical resection of their
primary tumor and in some cases of their synchronous metastases. However, the
efficacy of perioperative treatments should not decrease the quality of the
surgical resection and especially mesorectal excision as well as the need for
high quality pathological examination which must be very thorough with analysis
of a sufficient number of lymph nodes. The efficacy of combined treatment in
advanced rectal cancers is a major argument in favor of the multidisciplinary
coordination required for optimal treatment of patients with rectal cancer.
PMID- 10670151
TI - [Role of subtotal/total colectomy in emergency treatment of occlusive cancer of
the left colon].
AB - PURPOSE: The aim of this study was to evaluate the results of management of
acutely obstructed carcinoma of the left colon by emergency subtotal/total
colectomy (STC) with immediate anastomosis without diversion. METHODS: STC was
performed in 60 consecutive patients (mean age 72 years). Inclusion criteria were
reasonable operative risk, resectable acutely obstructed carcinoma, massively
distended colon of dubious viability, signs of impending cecal perforation.
RESULTS: Postoperative mortality was 6.6% (n = 4): 3 patients over 85 years of
age died postoperatively as a result of cardiopulmonary complications; an 83 year
old female died as a result of an anastomotic dehiscence. Morbidity was 10% (n =
6) including one fistula which recovered without surgery. There were 5
synchronous colon cancers. Six months after surgery, the mean daily stool
frequency was 2 after STC, and 3 after TC. CONCLUSION: Emergency STC achieves one
stage relief of bowel obstruction and tumor resection by encompassing a massively
distended and fecal-loaded colon with ischemic lesions, ensures restoration of
gut continuity via a "safe" anastomosis and removes a possible synchronous
carcinoma.
PMID- 10670152
TI - [Left colectomy with immediate anastomosis in emergency surgery].
AB - PURPOSE OF THE STUDY: A retrospective study of our experience with one-stage left
colectomy for acute diverticulitis and obstruction with a review of the
literature to more clearly define the indications of this procedure. PATIENTS AND
METHODS: 30 patients were operated for acute diverticulitis (group 1) and 47 for
obstruction (group 2). Only 7 patients (23%) of group 1 had an intraoperative
colonic lavage while this was performed for all the patients of group 2. RESULTS:
The postoperative morbidity and mortality for the patients of group 1 and 2 were
37 and 28%, and 7 and 11% respectively. None of the patients of group 1 had
clinical anastomotic leak, while this occurred in 2 patients (4%) of group 2. The
mean hospital stay was 26 days for patients of group 1 and 17 days for patients
of group 2. CONCLUSIONS: Bowel obstruction should be treated by one-stage left
colectomy and intraoperative colonic lavage for patients with low anaesthetic
risks (ASA 1 and 2). Immediate anastomosis protected by colostomy or ileostomy
could be proposed for patients with an intermediate risk (ASA 3). Patients with
acute diverticulitis and a localized abscess or peritonitis should be treated
with one-stage colectomy; an immediate protected anastomosis could be performed
in patients with generalized purulent peritonitis while a Hartmann's type
colectomy should be the reasonable option for fecal generalized peritonitis.
Intraoperative colonic lavage does not seem mandatory.
PMID- 10670153
TI - [Self-expandable metal stent in the treatment of obstructive cancer of the left
colon. Preliminary results and review of the literature].
AB - AIM: To report our preliminary experience with self-expandable metal stent in the
treatment of acute malignant obstruction of the left colon and to review the
literature on this specific subject. PATIENTS AND METHODS: From March to
September 1999, 8 consecutive patients with a mean age 71 were admitted as an
emergency for acute malignant obstruction of the left colon. A self-expandable
metal stent was inserted under radioscopic and, in 4 cases, endoscopic guidance.
The patients then underwent bowel preparation before operation, if required.
RESULTS: There was no mortality. Bowel preparation was satisfactory in 6 cases.
Complications occurred in 1 patient, who was operated on day one for peritonitis
due to perforation of the tumour by the prosthesis inserted after dilatation.
Another six patients were operated: 2 had resection followed by anastomosis; 3
had resection and anastomosis protected by ileostomy; 2 had Hartmann's procedure.
The last patient retained the prosthesis as palliation. In the literature, self
expandable metal stent application in obstructed carcinoma of the left colon
gives satisfactory results. CONCLUSION: Based on our experience and a review of
the literature, we provide practical recommendations when inserting self
expandable metal stents for acute malignant left colonic obstruction.
PMID- 10670154
TI - [Colonic diverticulosis and laparoscopy. Analysis of a series of 60 cases].
AB - AIM: This is a retrospective analysis of a series of 60 cases diverticular
disease. MATERIAL AND METHOD: From May 1991 to April 1999, 60 laparoscopic
colorectal resections were performed for diverticulitis. RESULTS: Conversion to a
classical procedure was necessary in 3 patients (5%). There was no mortality and
9 postoperative complications (3 reoperations). The mean length of hospital stay
was 9 days, and 6.3 days for patients in whom surgery was performed after January
1998. CONCLUSION: Laparoscopic surgery for diverticular disease is associated
with acceptable morbidity and mortality rates and a short median postoperative
stay.
PMID- 10670155
TI - [Laparoscopic ileo-colic resection in Crohn's disease].
AB - The objective was to evaluate the reliability and safety of laparoscopic
ileocolic resection for Crohn's disease. PATIENTS AND METHODS: From June 1995 to
February 1999, 40 patients underwent a laparoscopic ileocolic resection for
Crohn's disease. Fistulizing disease, phlegmons and patients with previous
laparotomy were excluded. Early morbidity, postoperative comfort and clinical
recurrence were rates evaluated. RESULTS: No intra-operative incident or
conversion occurred. Mean operating time was 163 min. Complications occurred in
three patients: 1 pelvic hematoma with super-infection, 1 protracted ileus (7
days), 1 venous thrombosis. Opiate analgesics were used for a mean period of 3.1
days. Delay before bowel movements was 3.2 days. Post-operative hospital stay was
8 days. Mean size of the wound was 4.1 cm. Twelve patients (30%) developed long
term clinical recurrence; the mean disease-free interval was 10 months. No
patient required secondary re-operation. CONCLUSION: Laparoscopic ileocolic
resection was reliable and safe in the treatment of Crohn's ileal strictures. The
possible role of this method in the treatment of fistulizing disease or
recurrence has to be evaluated.
PMID- 10670156
TI - [Spontaneous colonic ischemia].
AB - Spontaneous ischemic colitis is a frequent disease, affecting mostly elderly
people and predominantly localised on the left and sigmoid colon. It is due to
alterations of small vessels of the colon and/or modifications of the splanchnic
blood flow. Spontaneous evolution is generally favorable with restitution ad
integrum of the disease colon. The diagnosis of ischemic colitis is established
from the clinical picture, CT-scan and colonoscopy. Surgery, under the form of
colonic resection, is required in 15% of cases approximately, in case of colonic
necrosis.
PMID- 10670157
TI - [Concerning "Intraperitoneal polyglactin 910 absorbable prosthesis: a risk-free
preventive method?"].
PMID- 10670158
TI - [Interest in ophthalmologic examination for familial adenomatous polyposis].
AB - We describe the clinical history of four patients belonging to a familial
adenomatous polyposis (FAP) family. We stress the importance of a fundus
examination for the screening of carriers of the gene responsible for familial
adenomatous polyposis.
PMID- 10670159
TI - [Congenital toxoplasmosis: presentation of a case].
AB - We report a case of a 4 months old boy with esotropia of the left eye with large
bilateral chorioretinal toxoplasmic macular scars. Chorioretinal scars are the
most common eye finding in congenital toxoplasmosis and are often located in the
macular region. Most infants with congenital infection are asymptomatic at birth
but will develop retinal and/or neurologic damage later in life with consequent
loss of vision. A routine examination of the fundus and computed tomography of
the head can be negative. Serologic testing is essential for the diagnosis and
the follow-up of the infection. Every infant with evident or suspected congenital
infection by Toxoplasma gondii must be treated by Pyrimethamine, Sulphadiazine
and Folinic Acid during at least the first year of life with regular serologic
testing and ophthalmologic examination. Neurologic outcome is better with
treatment and the risk of chorioretinitis seems reduced.
PMID- 10670160
TI - Silicone oil vs. gas for the treatment of full-thickness macular hole.
AB - The purpose of this study is to evaluate the anatomic and visual outcomes, as
well as the complications, of macular hole surgery with SF6-gas tamponade versus
silicone-oil tamponade. Fifty-four (54) eyes with idiopathic macular hole
underwent vitrectomy and peeling of the internal limiting membrane (ILM) around
the hole. Nineteen (19) eyes were treated with SF6-gas tamponade (group 1) and
the other thirty-five (35) eyes with silicone-oil tamponade (group 2). An
excellent anatomic success rate was obtained in both groups (94.7% in group 1 and
97.1% in group 2). Nevertheless, the postoperative visual acuity (VA) in the
group treated with silicone-oil tamponade was significantly better than in the
group treated with gas tamponade (P = 0.0217). Forty-seven (47) of the eyes in
group 1 and 74% in group 2 achieved a VA = 0.4 or better. The most frequent
potentially vision threatening complication we observed was RPE alterations in
35% of the eyes in group 1 and in only one eye in group 2. None of the eyes
developed a retinal detachment during the follow-up period. In conclusion, the
treatment of idiopathic macular holes by vitrectomy and ILM peeling provides a
very good anatomic success rate. An excellent recovery of visual acuity, up to
1.0, was more frequently observed in the group treated with silicone oil
tamponade.
PMID- 10670161
TI - [Placoid pigment epitheliopathy and cerebral vasculitis: a clinical case].
AB - We report the case of a 21 year old man who has severe headache and blurred
vision since 2 weeks. Ophthalmologic examination discloses typical lesions of
acute posterior multifocal placoid pigment epitheliopathy and an homonymous right
inferior quadrantanopsia. An inflammatory syndrome and a cerebrospinal fluid
lymphocytosis are found. Cerebral imagery is normal. Headache improves only with
corticotherapy. We conclude that the neurological attack associated with this
acute posterior multifocal placoid pigment epitheliopathy is most likely due to a
cerebral vasculitis.
PMID- 10670162
TI - Radiation-associated choroidal neovasculopathy, exudative detachment and
neovascular glaucoma. A case report.
AB - Radiotherapy remains a controversial type of therapy for subfoveal
neovascularization. Recently a peculiar pattern of neovascular growth of the
irradiated choroidal neovascular membrane has been described. This evolution may
be associated with extensive exudative reaction. In one of our patients with this
complication, the disease progressed to a total exudative retinal detachment and
neovascular glaucoma.
PMID- 10670163
TI - Target pressures in glaucoma.
AB - Despite exciting progress in the field of neuro-protection, lowering the
intraocular pressure is still the only available option to treat glaucoma
patients. The level to which the intraocular pressure should be lowered is
different for each individual patient. The formula proposed to calculate the
"target pressure" takes into account the pressure at which the glaucomatous
damage presumably occurred (the "maximum pressure") and the risk of future
damage. This target pressure should be re-evaluated periodically.
PMID- 10670164
TI - Acanthamoeba keratitis: a review.
AB - Acanthamoeba keratitis is caused by protozoa and characterised by a protracted
course. All patients presenting with a therapy-resistant keratitis, even non
contact lens wearers, should be examined for the presence of Acanthamoeba by
means of specific cultures, histopathological stainings and--if necessary--a
corneal biopsy. The combination of clinical signs, such as excessive pain, a
radial keratoneuritis and in a later phase a stromal ring infiltrate, together
with a suggestive history (contact lenses, polluted water) is an important factor
for the early diagnosis. Because of improved clinical detection and earlier
diagnosis, the infection can often be controlled with a combination therapy of
polyhexamethylene biguanide or chlorhexidine with propamidine and neomycine. This
results in a better visual prognosis and a decreased need for therapeutic
keratoplasty.
PMID- 10670165
TI - Comparison of the effect of Healon vs. Viscoat on endothelial cell count after
phacoemulsification and posterior chamber lens implantation.
AB - To evaluate the protective effect of 1% sodium hyaluronate (Healon) vs. a mixture
of 4% chondroitin sulfate and 3% sodium hyaluronate (Viscoat) on the central
corneal endothelium during surgery, we prospectively examined 20 eyes of 20
patients who underwent clear corneal phacoemulsification and implantation of an
intracapsular posterior chamber intraocular lens (PC-IOL) with either Healon (10
eyes) or a combined use of Viscoat and Healon (10 eyes) as viscoelastic material.
We compared the central endothelial cell counts, recorded by specular microscopy,
preoperatively and 6 weeks postoperatively. Our results suggest that Viscoat
offers no significant better endothelial cell protection during
phacoemulsification than Healon.
PMID- 10670166
TI - A one year experience with the multislice helical CT.
AB - New detector morphology and increased computer power have led to a second leap in
CT technology. With multislice helical CT, four slices per rotation are
reconstructed resulting in a 3 to 6 times reduction of the examination time.
During our one-year experience with the multislice CT, we have learnt that the
major advantage of the technique is the possibility to cover a large volume with
thin slices. Combination of both makes it possible to scan an entire anatomic
region during the optimal enhancement phase (after i.v. contrast injection) with
a high spatial resolution. New diagnostic possibilities can be explored by CT
together with improved and more detailed post-processing tools.
PMID- 10670167
TI - [Alveolar proteinosis: signs and prognosis using high-resolution computed
tomography in 5 patients].
AB - Pulmonary alveolar proteinosis is a rare idiopathic diffuse airspace disease
characterized by intraalveolar accumulation of large quantities of
lipoproteinaceous material. The clinical presentation and course are variable and
the definite diagnosis is made by biopsy or broncho-alveolar lavage (BAL) that
also constitutes the unique and empiric treatment. We report the extremely
typical HRCT features of the disease found in a series of five patients diagnosed
in our institution over a ten-year period. The HRCT signs and their evolution are
discussed. A continuous spectrum of findings going from isolated ground glass
opacities to lobular consolidation is found, but the most common and invariably
present pattern consists of ground glass areas with superimposed smooth septal
thickening; these areas have a patchy or geographic distribution--often termed
the "crazy-paving" pattern--and are unlike pulmonary findings in any other
disease.
PMID- 10670168
TI - An undescribed coexistence of a subserosal exophytic gastric leiomyoma with a
serous microcystic pancreatic adenoma.
AB - We present the case of a 66-year-old woman with complaints of odynophagia but
normal gastro-oesophagoscopic findings. On computed tomographic examination, a
presumptive diagnosis of a cystic liver tumor and a microcystic pancreatic
adenoma was made. Histopathological examination of the hepatic mass, however,
revealed a subserosal exophytic gastric leiomyoma. Considerations to avoid the
potential pitfall of diagnosing an exogastric leiomyoma as a liver tumor are
emphasized. Moreover, the unique association of an exogastric leiomyoma and a
serous microcystic pancreatic adenoma is discussed.
PMID- 10670169
TI - Leptomeningeal metastases from ethmoid sinus adenocarcinoma: clinico-radiological
correlation.
AB - A patient with sinonasal adenocarcinoma is presented with leptomeningeal
metastases affecting multiple cranial nerves and spinal nerve roots. Head and
neck cancer is known to be an extremely rare source for leptomeningeal metastatic
spread. The cranial nerves, the spinal cord and roots and the cerebral
hemispheres can be affected in case of leptomeningeal metastatic spread.
Examination of the CSF is the hallmark of the diagnosis if leptomeningeal
metastatic spread is suspected, but this case illustrates that the combination of
specific clinical features on one hand and specific lesions on the Gd-enhanced T1
weighted MRI study on the other hand is reliable enough to make a presumed
diagnosis if the CSF analysis remains negative. We suggest that in our patient
direct leptomeningeal spread occurred through the cribriform plate to the CSF,
followed by further spread in a gravity dependent way.
PMID- 10670170
TI - Confrontation of mammography systems in flanders with the European Guidelines for
Quality Assurance in mammography screening. Analysis of initial results.
AB - From May 1997 to April 98, 30 radiological centers made an agreement with the
Leuvens Universitair Centrum voor Kankerpreventie (LUCK) for the work out of
physical and technical quality control in mammography screening. A protocol was
used based on the European Guidelines for Quality Assurance. The reports of all
30 acceptance tests were retrospectively reviewed. The following parts showed to
be most critical: alignment of radiation field and film in the bucky, tube
voltage precision, automatic exposure controller, average optical density of a
standard exposure, dark room and its safe lights. The mean film gradient was in
the majority of the centers higher than what is prescribed in the European
document. This is acceptable and even desirable whenever daily quality control
shows that the development system is sufficiently stable. Although it is
difficult to compare the scores for the specific tests with results in other
countries, there is evidence that the tendencies are very similar.
PMID- 10670171
TI - Tumours of the oropharynx and oral cavity: perineural spread and bone invasion.
AB - Clinical examination of the oral cavity and oropharynx provides essential
information in the assessment of neoplastic lesions. A precise evaluation of
their deep spread along the most common growth pathways can be achieved by
imaging, ranging from the basic, but nowadays incomplete, information of
conventional X-ray, to the sophisticated details obtained by MR. Three
oncological questions must be faced: the three dimensional evaluation of primary
tumour spread; the assessment of nodal involvement; the post-treatment survey
with the early detection of local recurrences, during the follow up. Either CT or
MR accurately assesses the deep extension of neoplasms, nevertheless, the most
cost-effective protocol is provided by a combination of CT and ultrasound
(staging respectively T and N). MR is the technique of first choice when an
infiltration of the base of the tongue or perineural spread is suspected, because
of its superior ability to detect muscular invasion and segmental abnormalities
of cranial nerves. Bone involvement can be adequately showed by MR not only
because focal erosions of the cortical rim are well demonstrated, but also by
means of the early demonstration of bone marrow abnormalities. Moreover, MR plays
an essential role during the follow up, as it is the only morphological imaging
technique permitting to differentiate recurrent tumour and necrosis from scar
tissue.
PMID- 10670172
TI - Cross-sectional anatomy of the facial nerve.
AB - The length and complexity of the anatomical course of the facial nerve explains
the difficulty of its accurate morphologic evaluation. CT and MR appear to be
complementary techniques to precisely depict the nerve from its pontine origin to
the parotid gland. Anatomical variations exist in length or thickness of all
intrapetrous segments or as frequent dehiscences which can lead to false positive
results or at the opposite falsely negative diagnoses. Close relations with the
antero-inferior cerebellar artery in the intracisternal and intracanalicular
segments must be known. Gadolinium enhancement is usual in the fallopian canal
with variable intensity and thickness and should be differentiated from
pathological enhancement. Finally the intrapetrous course of the chorda tympani
can be precisely displayed on CT in the intra-osseous canal and in the middle ear
near the ossicles.
PMID- 10670173
TI - Aorto-enteric fistula.
PMID- 10670174
TI - Clinical aspects of pulmonary sarcoidosis.
AB - Pulmonary sarcoidosis has a variable natural course from an asymptomatic state to
a progressive life-threatening condition. Radiographic abnormalities are
frequently an important clue to the diagnosis. The diagnosis usually requires a
tissue biopsy that demonstrates noncaseating granulomas that cannot be ascribed
to another clinical condition. The lung may be biopsied, but extrapulmonary sites
may be biopsied for the diagnosis if such sites are involved with disease. When
the lung is biopsied, a transbronchial lung biopsy with a flexible bronchoscope
is the procedure of choice, even if the chest radiograph shows thoracic
adenopathy alone without obvious parenchymal infiltration. On occasion the
diagnosis can be made on clinical grounds without biopsy when the presentation is
highly specific for sarcoidosis, such as Lofgren's Syndrome. Treatment for
pulmonary sarcoidosis has not been standardized. Since many patients have
spontaneous remissions and the benefits of therapy do not affect the long-term
outcome, therapy is reserved for patients with severe or progressive pulmonary
symptoms and/or pulmonary dysfunction. Corticosteroids are the primary therapy
for pulmonary sarcoidosis. Corticosteroid therapy involves six phases: initial
high dose, taper to a maintenance dose, a maintenance dose, taper off
corticosteroids, monitor off therapy, and treatment of relapse if it occurs.
PMID- 10670175
TI - Alzheimer's disease in South Carolina, 1998.
PMID- 10670176
TI - Curricular renewal for the new millennium at the Medical University of South
Carolina College of Medicine.
AB - The MUSC College of Medicine is engaged in a curricular renewal process that
emphasizes increased integration of the basic and clinical sciences throughout
all four years of the curriculum, more self-directed learning, and earlier
patient contact for students. Several basic science courses have been modified
and a new "Doctoring Curriculum" has been introduced to develop students'
clinical skills and preparation for medical practice. Changes to the third year
of the curriculum include the new Deans' Rural Primary Care Clerkship. Other
third-year curricular changes include small-group case discussion sessions that
emphasize the integration of basic and clinical sciences in medical practice, and
the incorporation of nutrition throughout all fours of the curriculum. The
changes described in this manuscript are designed to address a wide range of
educational needs of future physicians, including the acquisition of the
attributes endorsed by the AAMC MSOP--altruism, knowledge, skillfulness and
dutifulness. This new curriculum will evolve over time and the goal remains to
help equip future physicians with the requisite knowledge, skills and attitudes
for medical practice in the new millennium.
PMID- 10670177
TI - Y2K.1. The tree of knowledge and the tree of life.
PMID- 10670178
TI - [Levels of total plasma homocysteine after methionine intake in a group of
healthy subjects in Northern + Italy. Relationship with age, gender, and
nutritional status].
PMID- 10670179
TI - [Risk factors of cardiovascular pathology after kidney transplantation. New
perspectives].
PMID- 10670180
TI - [I/D polymorphism of the ACE gene and A1166C of the AT1R gene as risk factors for
restenosis after coronary angioplasty].
PMID- 10670181
TI - [The genes that codify angiotensin converting enzyme and type 1 receptor for
angiotensin II have a different effect on longevity].
PMID- 10670182
TI - Molecular evidences for a hypercoagulable state in non insulin diabetes mellitus
patients with a history of thrombotic episodes.
PMID- 10670183
TI - [Vascular disease and asymptomatic diabetic patients].
PMID- 10670184
TI - [Apolipoprotein-E4, lipid profile and vascular dementia].
PMID- 10670185
TI - [Vascular risk factors, cognitive status, and affective tone in 2 groups of
elderly patients].
PMID- 10670186
TI - [Thrombophilic states. Prevalence and clinical correlations].
PMID- 10670187
TI - [Lp(a): a new risk factor for deep venous thrombosis?].
PMID- 10670188
TI - [The C1166 allele of the AT1R gene associated with ACE DD phenotype increases the
risk for deep venous thrombosis].
PMID- 10670189
TI - [Deep vein thrombosis in patients undergoing medical treatment. One-year
experience at a rehabilitation hospital].
PMID- 10670190
TI - [Important risk factors for venous thromboembolism. Analysis of 758 patients
studied at a thrombosis center].
PMID- 10670191
TI - [Diagnostic accuracy of various methods for the measurement of D-dimers in
patients with suspected deep venous thrombosis].
PMID- 10670192
TI - [Asymptomatic deep vein thrombosis in the bedridden elderly. Role of D-dimer as
screening test].
PMID- 10670193
TI - [Recurrences and new vein thrombotic events during oral anticoagulant therapy in
patients treated for previous vein thromboembolism. Data from the literature and
results of the ISCOAT study].
PMID- 10670194
TI - [Pretreatment with monoclonal antibody anti-CD18 prevents the trans-cellular
biosynthesis of sulfidopeptide-leukotrienes in vitro and in vivo and protects
from the subsequent functional changes in the isolated rabbit heart].
PMID- 10670195
TI - [Marfan's syndrome. Clinical and molecular characterization of 51 Italian
patients].
PMID- 10670196
TI - [Hyperhomocysteinemia and abdominal aortic aneurysm].
PMID- 10670197
TI - [Thoracic aortic aneurysm. New evidence for fibrillin-1 involvement].
PMID- 10670198
TI - [Changes in fibrinolysis after primary PTCA].
PMID- 10670199
TI - [Persistent generation of thrombin after coronary angioplasty].
PMID- 10670200
TI - [Effects of an angiotensin II receptor antagonist (valsartan) on macro- and
microcirculatory hemodynamics of the arm in hypertensive patients].
PMID- 10670201
TI - [Passive smoking and endothelial dysfunction].
PMID- 10670202
TI - [Does the presence of obliterative arteriopathy of the legs change the long term
mortality and survival of patients surgically treated for abdominal aortic
aneurysm?].
PMID- 10670203
TI - [Preliminary experience in the treatment of thoracic aortic aneurysm with covered
self-expandable endoprosthesis].
PMID- 10670204
TI - [Aneurysm of the lumbar aorta treated with a transluminal approach. Experience at
one center in 24 months].
PMID- 10670205
TI - [Use of endoprosthesis in aortoiliac aneurysms].
PMID- 10670206
TI - [Aneurysm of popliteal artery caused by extrinsic compression].
PMID- 10670207
TI - [Surgical treatment of aneurysm of the popliteal artery. Immediate and long-term
results].
PMID- 10670208
TI - [Significance of early diagnosis in vascular prosthetic infections].
PMID- 10670209
TI - [Late arterial thrombolysis. Indications, methods, and results of our
experience].
PMID- 10670210
TI - [Structural changes of the radial artery in patients with peripheral
atherosclerotic arteriopathy].
PMID- 10670211
TI - [Peripheral arteriopathy in pseudoxanthoma elasticum].
PMID- 10670212
TI - [Atherogenic risk factors in patients with obliterative arteriopathy of the
legs].
PMID- 10670213
TI - [Prevalence, topographic distribution, and pathogenesis of macro- and
microangiopathic vascular lesions in patients with diabetes mellitus.
Retrospective study].
PMID- 10670214
TI - [Relationship between hyperhomocysteinemia and endothelial activation in patients
with obliterative arteriopathy of the legs].
PMID- 10670215
TI - [Hyperhomocysteinemia and endothelial damage in abdominal aortic aneurysm].
PMID- 10670216
TI - [Cardiopulmonary baroreceptors activity and skin microcirculation in patients
with peripheral obliterative arteriopathy].
PMID- 10670217
TI - [Prognostic value of transcutaneous oximetry in critical ischemia].
PMID- 10670218
TI - [Proposed guidelines for the correct application of ultrasonography methods in
the diagnosis of deep venous thrombosis of the legs].
PMID- 10670219
TI - [Sural vein thrombosis and recurrence prevention. Which therapy?].
PMID- 10670220
TI - [Radiology in the prevention of pulmonary embolism. Vena cava filters].
PMID- 10670221
TI - [Home use of an ambulatory monitor for the determination of prothrombin time
(coaguchek) in patients treated with oral anticoagulants. Multicenter prospective
study].
PMID- 10670222
TI - [Venous and arterial thromboembolism: autoimmune syndrome with heparin-induced
thrombocytopenia. Unusual severe adverse reaction or the tip of the iceberg?].
PMID- 10670223
TI - [Quantification of venous reflux of the legs with scanner duplex method].
PMID- 10670224
TI - [Role of color Doppler ultrasonography in the study of venous ulcer of the leg].
PMID- 10670225
TI - [ULTRO protocol in the study and treatment of stasis ulcer of the leg].
PMID- 10670226
TI - [Changes of endothelium-dependent vasodilation in healthy subjects with familial
atherosclerosis of the supra-aortic branches].
PMID- 10670227
TI - [Dermal microcirculatory response to various stimulation tests assessed with
Doppler laser].
PMID- 10670228
TI - [Quantitative assessment of irrigation dermal microcirculation with computerized
biomicroscopy].
PMID- 10670229
TI - [Endothelial function of dermal microcirculation in patients with essential
arterial hypertension].
PMID- 10670230
TI - [Site specificity of biomicroscopic pattern in diabetic patients].
PMID- 10670231
TI - [Local anesthesia in carotid surgery].
PMID- 10670232
TI - [Indications and results of carotid TEA in the 90's].
PMID- 10670233
TI - [Perioperative myocardial ischemia in patients treated with carotid surgery.
Impact of the type of anesthesia (locoregional vs general].
PMID- 10670234
TI - [Selective use of shunts in carotid surgery. Personal experience].
PMID- 10670235
TI - [Carotid stenting. Immediate and long-term results].
PMID- 10670236
TI - [Incidence of atherogenic risk factors, carotid atherosclerosis, and eventual
correlations between etiology and clinical outcome in a group of patients with
cerebral ischemia. Retrospective study].
PMID- 10670237
TI - [Carotid atherosclerosis and juvenile stroke. First results of a longitudinal
study].
PMID- 10670238
TI - [Helicobacter pylori, Chlamydia pneumoniae, reactive C protein, and
cerebrovascular diseases].
PMID- 10670239
TI - [In situ activation of metalloproteinases by the fibrinolytic system as
pathogenetic mechanism of rupture of the atherosclerotic plaque].
PMID- 10670240
TI - [Ultrasonography tissue characterization of the carotid wall with integrated
backscatter signal analysis. A new alternative for the early diagnostic
assessment of atherosclerosis].
PMID- 10670241
TI - [Thickness of the intima media and coronary disease].
PMID- 10670242
TI - [Doppler color ultrasonography in the assessment of epiaortic vessels in giant
cell arteritis].
PMID- 10670243
TI - [Transcranial color coded sonography (TCCS) in the diagnosis and follow up of
spontaneous dissection of the internal carotid artery].
PMID- 10670244
TI - [Comparison between L-propionyl carnitine and physical-rehabilitative exercise in
diabetics with obliterative arteriopathy of the legs (Fontaine's stage IIa)].
PMID- 10670245
TI - [Alprostadil combined with antithrombotic drugs. Effects on hemorrhage time].
PMID- 10670246
TI - [Effects of infusion treatment once a day for 4 weeks with alprostadil-alpha
cyclodextrin on blood levels of endothelin-1 in patients with chronic
obliterative arteriopathy of the legs at Leriche-Fontaine stage 2].
PMID- 10670248
TI - Short term treatment with prostanoids in critical limb ischaemia: three months
follow-up.
PMID- 10670247
TI - [Shunt effect in iloprost treatment of obliterative arteriopathy].
PMID- 10670249
TI - [Treatment with prostanoid drugs. Analysis of 131 cases].
PMID- 10670250
TI - [Medical treatment of peripheral arteriopathies with alprostadil-alpha
cyclodextrin. Comparative analysis at national level of the expense/reimbursement
ratio].
PMID- 10670251
TI - [Gene therapy of critical ischemia of the legs. Improvement of genetic
transfection efficiency of endothelial cells in vitro, using cationic liposomes
and protamine sulfate].
PMID- 10670252
TI - Intimal-medial thickness of the common carotid arteries and lower limbs
atherosclerosis in the elderly.
AB - BACKGROUND: In the present study, the authors consider the possible association
between intimal-media thickness of the common carotid arteries and lower limb
atherosclerosis, in a group of elderly patients; the authors also consider the
presence of cardiovascular risk factors. METHODS: B-mode ultrasound measurement
of the intimal-media thickness of the common carotid arteries was performed on 80
subjects. Lower limbs atherosclerosis was defined as the presence of intermittens
claudicatio and/or ankle-arm index < 0.9. Baseline clinic examination and blood
tests were performed in all subjects to consider the presence of cardiovascular
risk factors. Linear regression analysis was used to assess the linear
relationship between intimal-media thickness of the common carotid arteries and
lower limb atherosclerosis. RESULTS: Linear regression analysis showed a
statistical association between increased values of intimal-media thickness of
the common carotid arteries and lower limb atherosclerosis. Sixty-four (80%)
subjects presented one or more associated cardiovascular risk factors.
CONCLUSIONS: The results of the the present study confirm that intimal-media
thickness of the common carotid arteries is a marker for the identification of
generalized atherosclerosis and may be useful for the identification of subjects,
even at early stages, at risk of cardiovascular diseases.
PMID- 10670253
TI - Recurrent aneurysms: late complication for patients previously submitted to graft
replacement for abdominal aortic aneurysm.
AB - BACKGROUND: The possibility to perform easy and cheap ultrasonographic
examinations of the abdomen allows us to face the problem of possible development
of new paraanastomotic aneurysms or aneurysms on native arteries in subjects
already submitted to endoaneurysmectomy of the abdominal aorta. The idea of
planning accurate programs of ultrasonographic follow-up of operated patients is
sustained by the hypothesis that the aortic aneurysm is an expression of a
systemic disease due to a connectival defect of genetic nature. METHODS: Two
different follow-up experiences are described: the first was a simple follow-up
based only on clinical evaluation of patients previously submitted to aortic
surgery in the last ten years at the Department of General and Cardiovascular
Surgery of the University of Milan, and the second experience a planned follow-up
programme based on instrumental evaluation of the patients. RESULTS: Thirty-one
cases of recurrent aneurysms of native arteries in 13 subjects already operated
for AAA from 3 to 13 years before are described. Despite the patients were evenly
inserted in a clinical follow-up, as a matter of fact, 25 of these lesions were
detected during occasional investigations performed for other reasons or for
rupture, while during the last two years, the planned ultrasonographic follow-up
of 95 patients detected 6 new aneurysms. CONCLUSIONS: Incidental detections of
new paraanastomotic true aneurysms or ectasia of native arteries far from the
graft are more and more frequent in patients already submitted to aortic
replacement for abdominal aneurysm. In the international literature only few
papers have been published about perspective studies based on instrumental follow
up of operated patients. The planning of such controls is mandatory, at present,
also in order to evaluate the clinical development of aneurysmatic disease.
PMID- 10670254
TI - Relationships between serum hyperhomocysteinemia and carotid atherosclerosis in
geriatric patients.
AB - BACKGROUND: Evaluate the relationships between serum total hyperhomocysteinemia
and carotid atherosclerosis. METHODS: The 102 consecutive patients over the age
of 65 epiaortic vessels were examined by means of a high-resolution echo-Doppler
and Doppler cw. Depending on the size of the atherosclerotic plaques in the
carotid the patients were divided into two groups: a) patients with lesions at
high thromboembolic risk (heterogeneous and/or ulcerated plaques, hemodynamically
significant stenoses > 70%); b) individuals with low risk carotid involvement
(IMT normal and/or thickened by > 0.8 mm and/or lumen stenosed by homogeneous
plaques < 70%). The quantitative assay of serum total homocysteinemia (tHCY) was
carried out by means of an immunofluorescent method (FPIA). Depending on their
tHCY values, the patients were broken down into those with normal tHCY (cut-off
14 mumol/l for the women and 16 mumol/l for the men; 62 patients, M/F = 34/28,
mean age 71 +/- 4); patients with mild hyperhomocysteinemia (tHCY 14-18 mumol/l
for the women; 16-20 mumol/l for the men; 19 patients, M/F = 11/8; mean age 74 +/
7); patients with moderate hyperhomocysteinemia tHCY 18 mumol/l for the women; >
20 mumol/l for the men; 21 patients, M/F = 18/3; mean age 74 +/- 7). RESULTS: As
against the individuals with normal serum concentrations of HCY (Fig. 2; chi 2: p
< 0.05), the patients with mild hyperhomocysteinemia (Odds ratio: OR = 1.48) and,
above all, patients with moderate hyperhomocysteinemia (OR = 4.6) were found to
have a greater prevalence of carotid lesions at high thromboembolic risk. No
significant differences within the three groups were found with regard to
distribution by age, gender and the prevalence of the more common cardiovascular
risk factors (smoking, diabetes mellitus, arterial hypertension,
hyperdyslipidemia). CONCLUSIONS: Hyperhomocysteinemia is associated with highly
severe carotid lesions at higher risk for cerebrovascular events.
PMID- 10670255
TI - [Carotid lesions and vascular risk factors].
AB - BACKGROUND AND AIMS: Recent studies have underlined a significant incidence of
peripheral arterial occlusive disease (PAOD) of the lower limbs in the general
population which is often wrongly diagnosed. The "classic" risk factors--like
dyslipidemia--are not always present in significant percentages in patients
suffering from PAOD of the lower limbs. The aim of this study was to evaluate the
incidence of the most common vascular risk factors (smoking, hypertension,
hyperglycemia, dyslipidemia) in patients suffering from stenosing lesions of the
extracranial carotid axes, comparing the data with similar findings in lower
limbs. Moreover, the authors evaluated the association between these risk
factors, carotid atheromatous lesions and ischemic cardiomyopathy (CI). METHODS:
A retrospective study was performed to evaluate the data from 1643 patients
examined consecutively. A total of 636 (age > 40, carotid stenosis > 40%,
presence of risk factors) were considered eligible. RESULTS: The results showed
that, contrary to the findings in patients suffering from PAOD, diabetes was not
among the most frequently associated risk factors, whereas a relatively large
number of patients had a history of smoking, including both smokers and ex
smokers. CONCLUSIONS: The difference in the most frequent risk factors identified
for PAOD and carotid lesions suggests different etiopathogenetic mechanisms for
the two districts.
PMID- 10670256
TI - Hemorheology and tissue oxygenation in hypertensives with lipoidoproteinosis and
peripheral occlusive arterial disease (POAD) treated with sulodexide and
pravastatine and evaluated with laser assisted optical rotational red cell
analyzer (LORCA) and transcutaneous oxymetry.
AB - BACKGROUND: During arterial hypertension it is often possible to find other
factors like lipoidoproteinosis and peripheral arterial disease (POAD), which can
accentuate blood rheological abnormalities in hypertensive subjects. A group of
hypertensives with lipoidoproteinosis (LP) and POAD were therefore examined to
evaluate the relationship between these factors and blood rheological disorders
and, if possible, to correct it. METHODS: We studied a group of 27 hypertensives
with LP and POAD (15 males and 12 females in menopause for at least 1 year, aged
48 +/- 4 years), with WHO stage I hypertension, obesity (BMI = 30 +/- 2), stage
II type "a" POAD, class 2 type "b" lipoidoproteinosis (acc. to Fredrick-son's
classification) and hyperfibrinogenemia. All patients received oral medication
with 500 lipidic units (ULS) sulodexide a day, 20 mg pravastatin o.d. orally, and
were put on a low-salt and low-calorie diet (1400 kcal/day) during a follow-up of
60 days. Blood rheology status was evaluated before and after treatment (red
blood cell--RBC--deformability and aggregability) using a new computerized
instrument, which uses laser rays: the laser assisted optical rotational red cell
analyzer (LORCA) (acc. to Hardeman) and RBC deformability using optical
microscopy under immersion (acc. to Zipursky and Forconi). Transcutaneous
oxymetry was also used to evaluate tissue oxygenation. RESULTS AND CONCLUSIONS:
At the end of the study a significant improvement (p < 0.01) was noted in the
blood rheological patterns of peripheral perfusion and tissue oxygenation. This
underlined the positive influence of sulodexide with pravastatin in improving
hemorheological patterns and modulating hypercholesterolemia and
hyperfibrogenemia in hypertensives with POAD II "a" and LP 2 "b" and blood
rheology disorders.
PMID- 10670257
TI - [Formulating a non-fat diet to induce essential fatty acid deficiency in rats].
AB - OBJECTIVE: To describe the manufacture of an experimental diet to cause essential
fatty acids deficiencies in rats. MATERIAL AND METHODS: Rats. We used Wistar rats
that were given a diet consisting of skimmed milk, starch, and dextrino maltose.
The fatty acids were measured by means of gas chromatography. RESULTS: The
prepared diet is considerably cheaper than laboratory animal feed and it is
effective in causing a fatty acid deficiency.
PMID- 10670258
TI - [Descriptive analysis of the nutritional support in a polyvalent intensive care
unit. Complications of enteral nutrition].
AB - OBJECTIVE: Description of the nutritional support in an intensive care unit.
REFERENCE POPULATION: Patients hospitalized in our ICU over a period of 48 months
(October 1994-September 1998). INTERVENTIONS: The study was carried out by means
of a review of the two data bases generated, one by using the clinical history
management program, and the other by using the artificial nutrition program.
RESULTS: Nutritional support is used in 31% of the non-coronary patients,
predominantly medical (61%), and followed by surgical (29%) and trauma (9%)
cases. These patients presented an APACHE (17.7 +/- 15), a hospitalization (15.8
+/- 14.9) and a mortality (26%) that was greater than that in non-coronary
patients who did not require the nutritional support. The delay in starting the
nutritional support is 2.8 +/- 1.9 days. In decreasing order, the nutritional
support is most used in medical (42%), trauma (37%) and surgical (18%) patients.
The access route is similar, enteral in 55% of the cases, with a predominance of
medical patients, and parenteral in 45% of the cases, with a predominance of
surgical patients. In 100 patients with a nutritional support in excess of 10
days, it was found that 87% at some time were given this enterally. In this group
we studied the gastrointestinal complications, finding these in 61% of these
patients, with the most frequent complication being an increase in the gastric
residue (44%). Diarrhea was found in 14% and broncho-aspiration in 3.4%. The
enteral route as the initial access failed in 25% of these cases, thus requiring
parenteral nutrition. CONCLUSIONS: In our unit we used nutritional support in 31%
of the non coronary patients, and these presented a greater severity, longer
hospitalization, and higher mortality than those patients who did not require
this. The beginning of the nutritional support is relatively early. The
gastrointestinal complications derived from enteral nutrition are very common,
with a predominance of gastric retention. In 25% of the critical patients who
begin enteral nutrition, this fails, and thus they require parenteral nutrition.
PMID- 10670259
TI - [The usual diet of a group of adolescents from Valencia].
AB - Adolescents are considered a high nutritional risk group because their
nutritional needs are increased with respect to other age groups, and because
this period of life coincides with changes in life style that affect, often
negatively, their eating habits. Our overall goal is to study the usual eating
pattern of Valencian adolescents together with their drink and tobacco
consumption, but the first stage focuses on setting up, validating and correcting
methods to be applied. The present study was therefore carried out in a sample
composed of 64 adolescents, ranging from 16 to 20 years of age. A self
administered survey developed in our Department was used to explore their food
preferences, eating habits, smoking habits and alcohol and coffee intake. The
following results were obtained: The number of daily meals was of 3.7 +/- 0.9.
The 91% takes the breakfast daily (milk with cereals or sweet rolls) and the
majority of the students eat a second mid-morning breakfast. Lunch is of the
traditional type, consisting of two courses. The first is rice or pasta, followed
by meat, fish or eggs usually accompanied by a side dish or salad. Fresh fruit is
the dessert eaten, almost daily by the majority of the sample. The most usual
drink is water. The 70% of the sample have one supplementary afternoon intake
"merienda". All of the surveyed people like fruits, pasta and chicken meat.
While, liver and legumes are disliked by the majority. The intakes of soft
drinks, snacks, alcohol, coffee and tobacco are moderate, being, all these
products mainly consumed during the weekend. The mean diet offers an excess of
proteins and saturated fat, while complex carbohydrates and dietetic fiber are
scarce. Nutritional intakes of iron, magnesium and zinc in girls, and magnesium,
folates and vitamin A in boys are estimated insufficient to fulfil their needs.
PMID- 10670260
TI - [Methods for registering food intake in laboratory animals].
AB - Registering the ingestive activity of laboratory animals can be carried out by
using electronic scales connected to personal computers, thus gathering data
files that allow calculation of the daily ingestion standards. The ingestion
parameters most often used in the standard analysis include the number, size, and
duration of the meals, the speed of ingestion, and intervals between feedings,
and the hunger and satiation indexes. It is necessary to know a minimum interval
between meals to distinguish between true meals and pauses within one and the
same meal.
PMID- 10670261
TI - [A patient with visceromegaly: risk factor for performing percutaneous endoscopic
gastrostomy. A clinical case].
AB - Percutaneous endoscopic gastrostomy is an easy and safe technique to provide an
enteral access for patients needing long-term enteral nutrition. Minor
complications may occur in 9% to 13% of patients. Life-threatening complications
appear in 1-3% of cases. Perforation of a hollow viscus leading to peritonitis is
a rare condition; hepatic perforation after placing a percutaneous endoscopic
gastrostomy (PEG) has not been reported previously. In patients with massive
visceromegaly an abdominal ultrasound may help in localizing the place of
punction avoiding surrounding organs.
PMID- 10670262
TI - [Anesthetic status monitoring: reality or pending matter?].
PMID- 10670263
TI - [Comparison of sevoflurane and propofol in the maintenance of and recovery from
anesthesia].
AB - OBJECTIVE: To compare the recovery of patients after anesthesia with sevoflurane
or propofol during open urological surgery or lumbar column surgery of
intermediate duration. PATIENTS AND METHODS: Thirty-six ASA I, II or II patients
were enrolled prospectively and randomly assigned to two groups to receive either
sevoflurane (n = 19) or proporol (n = 17). Anesthetic induction was accomplished
with thiopental, fentanil and vecuronium. During anesthetic maintenance a mixture
of 60% nitrous oxide in oxygen plus the drug under study was adjusted to keep
blood pressure and/or heart rate within +/- 20% of baseline. After surgery we
recorded time until eye opening, spontaneous breathing, extubation, orientation,
and identification of parts of the body. Side effects were likewise recorded. In
the postanesthetic recovery ward patient condition was assessed using the Aldrete
scale, the Newman-Trieger test and a visual analog scale for postoperative pain.
Consumption of analgesic during the first 24 h after surgery was monitored.
RESULTS: No significant differences were found in demographic data; duration of
anesthesia; anesthetic doses; or time until spontaneous breathing, extubation,
orientation or identification of parts of the body. Only time until eye opening
was shorter in the sevoflurane group than in the propofol group (6.9 +/- 3.3 vs
11.5 +/- 4.8 min; p < 0.05). No differences were recorded on scales reflecting
intermediate-term recovery. Analgesic consumption and the incidence of side
effects were similar in both groups. CONCLUSIONS: Sevoflurane and propofol are
comparable for anesthetic maintenance in urological and neurological procedures
of intermediate duration.
PMID- 10670264
TI - [Efficacy of 0.1 mg of subarachnoid morphine combined with bupivacaine on
postoperative analgesia in total hip arthroplasty].
AB - OBJECTIVES: To analyze the analgesic efficacy, safety and side effects of
subarachnoid morphine (0.1 mg) with bupivacaine in patients undergoing total hip
arthroplasty. PATIENTS AND METHODS: Thirty patients scheduled for total hip
replacement under spinal anesthesia with bupivacaine were randomly assigned to
two groups according to whether local anesthetic with 0.1 mg subarachnoid
morphine was also provided or not (group M [n = 15] and group S n = 15[,
respectively). Top-up analgesia with morphine was available through a patient
controlled device. Postoperative pain was assessed on a visual analogue scale
(VAS) and consumption of intravenous morphine in the first 48 hours after surgery
was recorded. RESULTS: VAS scores (mean +/- SD) were significantly lower in the
first six hours in group M, but no differences between the two groups were
observed thereafter. Total consumption of morphine at 48 hours was much lower in
group M (6.80 +/- 7.74 mg) than in group S (31.38 +/- 13.17 mg). The incidence of
nausea was high in both groups (46%). Slight pruritus affected 26.6% of patients
in group M. Urinary retention necessitating temporary placement of a catheter was
observed only in group M, where the incidence was 35.7%. No cases of respiratory
depression occurred. Drowsiness was observed in 26.6% of patients in group S in
comparison with 6.6% in group M. CONCLUSIONS: Combining 0.1 mg morphine and
bupivacaine for total spinal anesthesia during hip arthroplasty significantly
decreased the consumption of intravenous morphine during the first 48 hours after
surgery. No respiratory depression occurred and the only side effects were
urinary retention and mild pruritus and drowsiness.
PMID- 10670265
TI - [Changes in oxygen saturation in the jugular bulb during cardiac surgery].
AB - OBJECTIVE: Heart surgery with cardiopulmonary bypass (CPB) leads to changes in
supply and consumption of cerebral oxygen (DO2 and VO2C). Monitoring jugular bulb
oxygen saturation (SjO2) detects changes in the DO2C/VO2C ratio that occur in
patients undergoing heart surgery. The objective of this study was to determine
the evolution of SjO2, of the arteriovenous difference of cerebral oxygen and of
cerebral oxygen extraction, as well as the possible relation between those
variables and changes in mean arterial pressure, hemoglobin counts and
temperature in patients undergoing heart surgery with CPB. PATIENTS AND METHOD: A
prospective study carried out in 31 patients who underwent coronary valve
surgery. To monitor SjO2, each patient's internal jugular vein was cannulated
with an oximetric catheter in a retrograde direction to monitor SjO2. RESULTS:
Baseline SjO2 (68 +/- 7.4%), obtained after anesthetic induction, was similar to
SjO2 before (65 +/- 6%) and after (67 +/- 8.2%) CPB. However, SjO2 upon starting
CPB (60 +/- 8.6%) and during rewarming (63 +/- 3%) were significantly lower than
at baseline. SjO2 was significantly higher during hypothermic bypass (78 +/- 5%)
than at baseline. SjO2 ranged from a low of 60 +/- 8% as CPB was initiated to a
high of 78 +/- 5% during hypothermic CPB. Mean arterial pressure was
significantly lower at the start of bypass (44 +/- 6 mmHg) than anesthetic
induction (83.5 +/- 13.1 mmHg) and the decrease correlated with a significant
decrease in SjO2. Changes in mean arterial pressure were unrelated to significant
changes in SjO2 at other moments, however. Nor was there a significant relation
between changes in temperature or hemoglobin and the evolution of SjO2. At least
one episode of SjO2 desaturation (= 50%) occurred in 29% of the patients, with
the lowest values being recorded at the start of CPB and during rewarming.
CONCLUSIONS: The greatest risk of cerebral oxygen imbalance between supply and
demand occurs at the start of CPB and during rewarming, as shown by decreases in
SjO2 levels below baseline at those times.
PMID- 10670266
TI - [Transfusion needs during intraoperative and immediate postoperative periods in
arthroplasty of the hip and knee].
AB - OBJECTIVES: To determine the factors associated with immediate perioperative
transfusion requirements of hip or knee arthroplasty patients who have not been
enrolled in a blood salvage program. PATIENTS AND METHODS: This prospective study
collected demographic (age, sex, weight, height, etc.), physiological (hemoglobin
levels, coagulation times, preoperative platelet counts, etc.), clinical history
and anesthetic and surgical data (type of anesthesia, surgical diagnosis,
duration of procedure) in 112 patients undergoing orthopedic surgery: 19 cases of
primary knee arthroplasty, 77 cases of hip arthroplasty and 16 replacements of
hip arthroplasty. Logistic regression analysis of the aforementioned variables
was performed to search for factors related to transfusional needs during and
after hip arthroplasty or after knee arthroplasty, which was performed with a
tourniquet applied to render intraoperative transfusion unnecessary. RESULTS: The
variables that increased the risk of transfusion during surgery were duration of
procedure exceeding 120 min (OR 15.24; p = 0.01) and loss of over 500 ml of blood
during surgery (OR 11.4; p = 0.02). The variables associated with perioperative
transfusion were loss of over 500 ml in the postanesthetic recovery room (OR
12.6; p < 0.0001), hypotensive episodes during recovery (OR 11.7; p = 0.0001),
prosthetic replacement (OR 6.33; p = 0.005), height < 160 cm (OR 5.03; p = 0.02),
preoperative hemoglobin level < 13.5 g/dl (OR 4.97; p = 0.02), and surgery for
reasons other than osteoarthritis (arthritis, pathological fractures, etc.) (OR
4.60; p = 0.04). Variables associated with transfusion of over two units of
packed red cells were a history of neoplastic disease unrelated to arthroplasty
(OR 378.67; p = 0.005), prosthetic replacement (OR 49.71; p = 0.009), diabetes
(OR 36.49; p = 0.02) and a hypotensive event while in the postanesthetic recovery
room (OR 29.12; p = 0.02). CONCLUSION: These results suggest that certain
modifiable factors increase the risk of blood transfusion in knee and hip
arthroplasty. Specifically, they are duration of surgery, intra- and
postoperative bleeding, preoperative hemoglobin level and instances of
perioperative hypotension. Other factors outside our control are height or
patient clinical history.
PMID- 10670267
TI - [Ropivacaine].
AB - This paper describes the pharmacological, pharmacokinetic and pharmacodynamic
features of ropivacaine on both an experimental and clinical level. Ropivacaine
is an amide-type local anesthetic whose chemical structure is related to that of
mepivacaine and bupivacaine and whose duration of effect falls between the two.
Ropivacaine is a less potent effector of motor blockade than bupivacaine, and its
toxic effects on the central nervous system and myocardial tissue is likewise
less. Ropivacaine has been employed for epidural anesthesia and analgesia
(including through a caudal approach), for peripheral motor blockade, for local
infiltration (in gel form), and for intravenous regional anesthesia in
ophthalmologic surgery involving peri- and retrobulbar blockade. Subarachnoid use
has not yet been accepted in Spain, although phase IV clinical trials of this
application have begun. Concentrations of 2 mg/ml (0.2%) and 7.5 mg/ml (0.75%)
and 10 mg/ml (1%) are available in Spain.
PMID- 10670268
TI - [Headache caused by endocranial hypotension secondary to sacrococcygeal trauma in
a patient with a congenital arachnoid cyst].
AB - Headache caused by intracranial hypotension after sacrococcygeal trauma, is a
rare syndrome with very similar symptoms and physiopathology to post dural
puncture headache. In both situations, cerebrospinal fluid (CSF) leaks through a
dural tear, leading to a decrease in its pressure. A 13 year old patient
presented a frontal and occipital positional headache, after undergoing
sacrococcygeal trauma. In magnetic resonance images, the presence of a spinal
arachnoid diverticulum (cyst) and CSF leak were confirmed. After the
establishment of conservative medical treatment, complete clinical remission was
observed. The diagnosis of intracranial hypotension headache syndrome is mainly
clinical, once other possible headache etiologies have been discarded. Magnetic
resonance imaging can be used to detect small CSF leaks, and in this case,
magnetic resonance imaging clearly showed the existence of an arachnoid cyst. The
presence of some meningeal diverticulums such as arachnoid cyst, constitute a
risk to undergo this syndrome, due to the possibility of its rupture by minor
traumatisms. The initial treatment should be conservative, as the dural tear
seals spontaneously and the liquid is reabsorbed.
PMID- 10670269
TI - [Remifentanil and sevoflurane in laparoscopic bariatric surgery].
PMID- 10670270
TI - [Paradoxical air embolism during catheterization of the right subclavian vein].
PMID- 10670271
TI - [Pre-eclampsia and treatment with urapidil].
PMID- 10670272
TI - [Difficult intubation in a case of ankylopoeitica spondylitis].
PMID- 10670273
TI - [Complete obstruction of a urinary catheter caused by urate deposits associated
with a continuous perfusion of propofol (ivofol)].
PMID- 10670274
TI - [Anterior bridges with the IPS-Empress-2 System after alveolar ridge
augmentation. A case report].
AB - The success of a prosthesis is judged according to optimal function, good chewing
comfort, adequate phonetics and white and pink esthetics. The aim of a treatment
is to approach the perfection of nature. For anterior bridgework, the all-ceramic
System IPS Empress 2 offers light transmission and reflection comparable to that
of natural teeth, provided that the pink esthetics are optimised in the
preprosthetic phase. The provision of an anterior bridge in the IPS Empress 2
system is presented here in the form of a case report. After extraction of the
anterior teeth, a ridge augmentation including preparation of the pontic bed was
carried out. The type of post and core, preparation and cementation are important
parameters for the success of all-ceramic restorations.
PMID- 10670275
TI - [The pregnant patient in dental care. Survey results and therapeutic guidelines].
AB - In a telephone survey using a standardized questionnaire, 78 resident dentists in
Germany, Switzerland and Austria were interviewed with respect to several aspects
of the dental treatment of pregnant women. Only 58% of the interviewees decided
clearly in favour of local anaesthetics, 59% supported the use of analgesics, 70%
a possible antibiotic therapy and 33% a radiological examination during
pregnancy. In addition, according to references in the specialist literature
guidelines for the dental treatment, drug therapy and radiological diagnosis of
pregnant women are presented. The local anaesthetics should have a high plasma
protein bonding (articain, bupivacain, etidocain) and a minimum adrenaline
concentration. Paracetamol is the analgesic of choice. If an antibiotic treatment
is required, penicillin, cephalosporin and erythromycin are recommended. In
particular during the first three-month period, radiological examinations should
be restricted to the absolute minimum and performed only if no reasonable
alternative is available, even though the radiological burden on the foetus falls
500,000 times short of the limit value of 50 mgray (5 rad) in the case of a
microradiogram, and 50,000 times short of the limit value in the case of an
orthopantomogram.
PMID- 10670277
TI - [Antibiotic resistance: current data from around the world and Tunisia].
PMID- 10670276
TI - [Consumption of antibiotics in Tunisia].
PMID- 10670278
TI - [Methods for estimating the cost of nosocomial infections].
PMID- 10670279
TI - [Markers of viral hepatitis in blood donors. Study apropos of 300 donors].
AB - In order to locate the rate of positivity of the different markers of hepatitis
that can be transmitted through blood (Ag HBs, anti-HBc Ab, anti-HCV Ab and
transaminases (ALAT)), we have conducted a study over 300 blood donors and who
are sale, equally shared between the parts of age and of sex. The ALAT were
superior to the normalcy in 10.66% of the cases, the male sex being 3 times more
affected than that of the female. The Ag HBs was positive in 4.66% of the cases.
The male sex is twice as affected as the female sex. One of three persons who
donated blood (37.33%) had anti-HBc Ab. Finally none of the 300 blood donors has
the anti-HCV Ab. There's a very weak recovering between the presence of Ag HBs
and of ALAT superior to the normalcy, a weak recovering between Ag HBs and anti
HBc Ab and a certain recovering between ALAT superior to the normalcy and the
presence of anti-HBc Ab. There is no recovering between the anti-HCV Ab and the
indirect markers. Eventually, the systematization of all these tests over each
donation engenders the elimination of more than 2/5 of the collected products.
PMID- 10670280
TI - [Diagnostic and therapeutic aspects of lymphatic tuberculosis: apropos of 42
cases].
AB - We report a retrospective study of 42 cases of lymph node tuberculosis. We noted
symptoms of tuberculosis impregnation in 92%, cervical localization in 71%,
positive tuberculin intra-dermo-reaction in 77%, and accelerated erythrocyte
sedimentation rate in 73% of the cases. Koch bacillus was detected in
expectoration, urine or gastric liquid at the rate of 11% of the cases. Lymph
node function was suggestive in 4 out of 12 patients, showing giant cells with or
without caseum. Lymph node biopsy, performed in 32 patients, was contributive in
94% of them. Another tuberculous localization was found in 14 cases mainly
pulmonary (8 cases).
PMID- 10670281
TI - [Detection and molecular typing of human papillomaviruses: prevalence of cervical
infection in the Tunisian central region].
AB - There are compelling molecular and epidemiological data which indicate that
infection with certain genital human papillomaviruses (HPVs), such as HPV 16 and
HPV 18, has a critical role in initial changes that lead to cervical and probably
other anogenital cancers. These observations prompted us to investigate the
prevalence of cervical infection with genital human papillomaviruses in Tunisia.
We used the polymerase chain reaction (PCR) to detect and type HPV DNA. The
prevalence of HPV infection in a population of 106 Tunisian women recruited at
the Offices Nationaux de la Famille et de Population (ONFP) was 13.6%. Molecular
HPV typing indicated a high prevalence of HPV at high oncogenic risk; Our results
indicate that the infection with genital human papillomaviruses is frequent in
the Tunisian population.
PMID- 10670282
TI - [Cavopulmonary shunts: apropos of 40 observations].
AB - Fourty patients with univentricular heart, underwent a cavopulmonary shunt
procedure. The majority have an excellent hemodynamic status with ventricular end
diastolic pressure > 12 mmHg and a mean pulmonary artery pressure > 15 mmHg.
However, 11 patients have ventricular dysfunction, 9 have an incompetent systemic
atrio-ventricular valve and 6 have mean pulmonary artery pressure > 15 mmHg. The
pulmonary arteries were of a good size in all cases with a Nakata index > 100
mm2/m2. Cavopulmonary connections are satisfactory palliative procedures in the
treatment of univentricular cardiac disease.
PMID- 10670283
TI - [Spontaneous contrast of the left atrium in mitral valve stenosis].
AB - The left atrial spontaneous contrast is uncommon finding during transthoracic
echocardiography. Transesophageal echocardiography provides superior imaging of
the left atrium and left spontaneous contrast has been detected more frequently
by this technique in rheumatic mitral stenosis. In order to analyze the
significance of spontaneous contrast, we have studied 100 patients with mitral
stenosis. Trans thoracic and transesophageal echocardiography were performed in
all patients. Left atrial spontaneous echo contrast was detected in 60 patients
(group A) and was absent in 40 patients (group B) The mean of mitral valvular
area was 0.9 10.2 mm in group A and 48 9.5 mm in group B (p < 0.001). Ther was a
high incidence of atrial fibrillation in group A; 63% VS 12% in group B (p <
0.001). A systemic embolization was noted in 20% of patients in group A; No one
of group B has presented this complication (p < 0.001).
PMID- 10670284
TI - [Prognosis of intraventricular septal rupture in myocardial infarct: apropos of
13 cases].
AB - The authors report the experience about 13 cases of postinfarction ventricular
septal rupture. Patients (9 men and 4 women) aged 60 to 76 years average 68
years. The site of necrosis was the anterior wall in 8 cases and the posterior
wall in 5 cases. The diagnosis of septal rupture was confirmed by
echocardiography and/or angiography. 6 patients died after averages: 7 days.
Surgical intervention was performed in 7 cases after a mean of 51 days following
the date of the myocardial infarction after an intensive care. We emphasize to
demonstrate the helpful of intensive care and the role of early surgery for a
good prognosis.
PMID- 10670286
TI - [Postpartum myocardial infarct (apropos of a case)].
AB - We report the case of a 26 years old woman, who was hospitalized for an acute
anterior myocardial infarction, which happened 17 days after delivery. The
culprit lesion was a coronary dissection observed on the coronary angiogram which
was performed on the 7th day. This dissection cicatrised spontaneously at the
control coronarography performed 3 months later. Conventional medical treatment
seems to be sufficient, although the use of thrombolysis in our case was safe and
successful.
PMID- 10670285
TI - [Mixed form of total anomalous pulmonary venous connection: apropos of a case].
AB - As opposed to partial anomalous of pulmonary venous connection, it is frequent
and benigns, the total anomalous of pulmonary venous connection is extremely rare
and more serious. The anomalous is severe because all pulmonary venous
connection, instead of left heart it go to the right heart. The age of diagnosis
is closely tied up anatomics characteristics, so various clinical cases are
present. The TAPVC of new born is a surgical emergency, especially where it's
block up and release++ cardiorespiratory distress syndrome secondary to OAP. For
great children, the total anomlous of pulmonary venous connection can be assumed
to a case of atrial septal defect. This study intend to clear up this clinical
and anatomical polymorphism and to report an exceptional-form of this congenital
anomaly which is mixed total anomalous of pulmonary venous connection.
PMID- 10670287
TI - [Colonic tuberculosis: an exceptional cause of a massive surgical hemorrhage
apropos of a case and review of the literature].
AB - Colonic tuberculosis rarely causes massive bleeding, as a matter of fact less
than twenty cases have been reported in medical literature. Resorting to surgery
in this context is even more exceptional. We have not found any case operated on
in the literature we have consulted. Endoscopy together with histological study
of biopsies is the best exam for the diagnosis of this disease. We report the
case of a 37 year old male, coronarian, carrying a caecal lesion evocative of
tuberculosis at the endoscopic exam, who had an emergency right hemicolectomy for
massive bleeding caused by caecal tuberculosis. The surgical indication was
dictated by the abundance and the persistence of the bleeding. The post-operative
course was uneventful.
PMID- 10670288
TI - [Effect of fasting on glycemia and proteinemia in young and adult rats].
AB - The aim of Our work has consisted of studying the effects of a severe three-day
fast on the evolution of the body weight, on glycemia and on proteinemia among
the young and mature male rats. The decrease in body weight which is more marked
among young rats after starvation shows that the loss of body mass due to fasting
decreases with the age of the rats. The physiological perturbations of nutritive
constants that have been recorded during this period of fast show that the mature
rat first attacks its non-protein stocks or glucides, which leads to a decrease
in its glycemia and in its lipids; whereas the young rat uses its proteins after
only three days of starvation because of its small stock of lipids.
PMID- 10670289
TI - Healthcare professionals must learn to say sorry.
PMID- 10670290
TI - Can doctors' work really be expert nursing?
PMID- 10670291
TI - Case 7: breach of confidentiality. Psychiatric nurse talks about a client to a
newspaper and radio.
PMID- 10670292
TI - Evaluating the Pegasus Trinova: a data hierarchy approach.
AB - Understanding the efficacy of patient support surfaces is essential if pressure
sore management is to be both efficient and effective. However, laboratory and
clinical studies in this area are fraught with well recognized problems. This
investigation reports a combination of laboratory, randomized controlled trial
(efficacy data) and measures of effectiveness to illustrate the beneficial role
of a new dynamic integrated mattress and seat cushion system: the Pegasus
Trinova. Successful prevention of sores among a vulnerable patient population,
along with positive comments regarding the system's comfort and 'user
friendliness' are supported by laboratory measures of interface pressure to
provide a hierarchy of data. Such an approach may present one solution to the
lack of timeliness of most mattress clinical trials, thus allowing decisions
regarding new support surfaces to be made upon the basis of evidence, not on
anecdote or solely upon marketing claims.
PMID- 10670293
TI - A practical approach to dressing wounds in difficult positions.
AB - Despite the availability of an increasing number of innovative dressing products,
many patients' wounds remain a challenge to dress in practice. However, the
creative use of widely available products and other resources can help to address
some of the difficulties that are regularly encountered. If different sizes of
dressing (to allow for cutting and shaping) or more innovatively shaped products
(which may be more expensive per item) are used, this can result in a better
dressing fit and therefore increase product wear time which is both clinically
effective and cost-effective. When a good solution is found for dealing with
certain wound types then great benefit can be gained from publishing the
information to prevent others from struggling to overcome the same difficulties.
PMID- 10670294
TI - Family carers. 4: Designing services to support family carers in Sweden.
AB - This, the last of four articles focusing on family caregiving in Sweden,
considers ways in which services can be designed to better support and complement
care provided by the family. Drawing on the results presented in the previous
three articles (Vol 8(9): 582-8; Vol 8(10): 647-52; Vol 8(11): 735-40) the need
to provide flexible and responsive services will be highlighted. While
acknowledging the importance of services which help with the physical aspects of
caring, emphasis will be placed on the need to develop an expanded range of
interventions which recognize and respond to the social and emotional impact of
caring.
PMID- 10670295
TI - Confidentiality. 4: Patient confidentiality and the courts.
PMID- 10670296
TI - Autonomy or non-compliance in adolescent diabetes?
AB - Many physical, psychological, social and cognitive changes take place in
adolescence. Emerging personal values and beliefs, an acute awareness of body
image and a desire for peer conformity and increasing independence can make the
transition to adulthood troublesome. For teenagers with diabetes, usual
adolescent needs and concerns are complicated by the demands of a complex
treatment regimen. This can result in non-adherence to the recommended programme
of care and, consequently, poor glycaemic control, which increases the risks for
diabetes-related complications in later life. This situation poses a major
problem for healthcare professionals. Teenagers, however, are frequently
preoccupied with the present, and are unable to perceive, or will ignore, their
vulnerability to long-term health problems. This article discusses these
difficult issues and, taking into account the increasing need for autonomy and
independence in adolescence, makes recommendations for nursing practice.
PMID- 10670297
TI - The benefits of preparing children and parents for day surgery.
AB - Hospital admission for children inevitably provokes feelings of anxiety for both
parent and child. The development of day surgery has in some respects eased many
of these anxieties; however, without the support of both verbal and written
information and the development of quality preparation from children's nurses
anxiety will continue to exist. This article seeks to explore the benefits of
preparing children and parents for day surgery using preadmission education, and
suggests how improvements may be made to practice, education and research.
PMID- 10670298
TI - Cervical cancer. 2: Colposcopy, treatment and patient education.
AB - In the first article in this two-part series (Vol 8(11): 730-34) the issue of
cervical screening and the cervical smear test was described and discussed. This
article looks at colposcopy. When a woman receives an abnormal smear test result,
she will often require further examination of the cervix in order to identify the
degree and area of dyskaryosis. Colposcopy can often provoke feelings of fear and
anxiety in women and the nurse must help to alleviate these fears and anxieties.
Colposcopy and cervical intraepithelial neoplasia are discussed and the treatment
(if any) is outlined.
PMID- 10670299
TI - Cardiopulmonary resuscitation: are practitioners being realistic?
AB - Cardiopulmonary resuscitation (CPR) is now established medical practice for all
in-hospital cardiac arrests except where a specific 'do not resuscitate' (DNR)
order is in place. This article explores many of the ethical and moral issues
surrounding CPR and the use of DNR orders. It examines the success rate of in
hospital CPR and raises the question of what constitutes outcome success by
illustrating that at best only 15% of resuscitated patients survive to hospital
discharge. The article proposes that both patients and healthcare professionals
grossly overestimate the success of CPR and suggests that many elderly patients
might choose not to be resuscitated if they were allowed to make an informed
choice. It concludes by suggesting that further work needs to be undertaken with
regard to early assessment of all in-hospital patients, combined with realistic
and frank communication between healthcare professionals and patients if futile,
undignified and costly deaths are to be avoided.
PMID- 10670300
TI - EasiCath: an advanced alternative to indwelling urethral catheters.
AB - This article looks at EasiCath, the single-use hydrophilic catheter manufactured
by Coloplast Ltd. EasiCath is now widely used throughout the UK and Europe. Since
the launch of EasiCath, Coloplast has continued to develop its lubricated
catheters and with the recent inclusion of the 30 cm EasiCath on the Drug Tariff,
Coloplast now provides the most extensive range of lubricated catheters in the
UK. In recent trials looking at the cell count on the surface of hydrophilic
catheters following catheterisation, EasiCath performed well, indicating that it
is a safe choice of lubricated catheter (Biering-Sorensen et al, 1999). This,
combined with the benefits of the precoated, polished eyelets and the potential
cost saving to the GP (4.60 Pounds per box of 25) over a number of other
catheters available, means that EasiCath has become the first choice of
hydrophilic catheter for many patients.
PMID- 10670301
TI - Healthcare risk management: 18. Clinical audit systems.
PMID- 10670302
TI - Nurse anaesthetists should not be encouraged.
PMID- 10670303
TI - Nutrition and hydration are not options but rights.
PMID- 10670304
TI - Protecting people with disabilities from abuse.
PMID- 10670305
TI - Case 8: misappropriation of ward funds. Ward manager who took money from the ward
and a patient.
PMID- 10670306
TI - Measuring the size of the leg ulcer problem in an acute trust.
AB - The majority of patients with leg ulceration are cared for in the community.
There is insufficient evidence of the numbers of these patients who are being
cared for in acute hospitals. This study sought to identify the size of the
problem in one acute trust by means of a point prevalence survey. From a study
population of 931 patients, 17 had leg ulcers, giving a prevalence of 1.8%. Out
of 52 wards and units, staff on 44 (84.6%) said that patients with leg ulcers
were admitted on occasion. In the case of 19 (36.5%) wards and units this was as
infrequently as one or two patients a year. The results of this survey have
considerable implications for ensuring that all patients receive optimum care.
PMID- 10670307
TI - Inflammatory bowel disease. 1: Aetiology and pathogenesis.
AB - Inflammatory bowel disease, a chronic lifelong condition, affects between 15 and
30 people per 10,000 of the UK population. Despite the large number affected,
there seems to be a paucity of information on this subject in the British nursing
press. Hence, nurses have little or no understanding of the impact of this
illness, and there is a danger that the distress and debilitation that
inflammatory bowel disease can have on people's lives is underestimated. However,
a healthcare professional, armed with the appropriate knowledge and attitude, can
make a real difference to the quality of care that these patients receive. This
article is the first in a series of three that shall review the aetiology,
treatment and concept of patient participation in inflammatory bowel disease. The
series aims to enhance nurses' understanding and stimulate further investigation
into this chronic illness.
PMID- 10670308
TI - Confidentiality. 5: The rights of transplant recipients and donors.
PMID- 10670309
TI - Learning disabilities: supporting nurses in delivering primary care.
AB - This article introduces an educational project supported by The Queen's Nursing
Institute and sponsored by the Hertfordshire Nursing Trust. It reports on the
initial results from a literature review and its implications for nursing. There
is broad acknowledgement of a problem in the delivery of primary care nursing for
people with a learning disability, but little consensus on how to move either
medical or nursing practice forward. It was proposed, therefore, to
systematically assess the learning needs of nurses delivering primary care and to
develop an evaluated methodology for responding to those needs. A comprehensive
literature review was undertaken. Three consistent themes emerged: knowledge and
training needs; role definitions and liaison; and clinical issues. Implications
for nursing, and the future development of the project are considered.
PMID- 10670310
TI - Preventing rape and sexual assault of people with learning disabilities.
AB - This article will explore the increased prevalence of rape and sexual assault
among people with a learning disability and identify factors that exist which
increase this client group's vulnerability to becoming a victim of sexual abuse.
There is significant under-reporting of such incidents and very few cases end up
in prosecution. Within the nursing profession, there is much more that can be
done to help decrease the level of vulnerability of people with a learning
disability and to work with other agencies to advocate for legal justice and
therapeutic redress for individuals.
PMID- 10670311
TI - Nocturia, nocturnal polyuria and secondary nocturnal voiding.
AB - Getting up once to the toilet at night is normal. Getting up more than once may
be abnormal. Potential causes include: nocturia, which is bladder related;
nocturnal polyuria, which is cardiac in origin; and being awake for a variety of
reasons that are not linked to the bladder. Bladder problems, therefore, are not
always the reason for frequency in micturition at night and treatment will only
be effective if the correct cause and/or causes are identified. The most useful
investigation to help with diagnosis is a frequency volume chart linked to an
assessment identifying causes of secondary nocturnal voiding and nocturnal
polyuria. Getting up to the toilet at night will not always be successfully
treated by anticholinergics. Charting is the key to diagnosis, appropriate
interventions and successful outcomes. This article will focus on working
definitions, prevalence, causes, investigations and treatment options for
nocturia, nocturnal polyuria and secondary nocturnal voiding.
PMID- 10670312
TI - Current recommendations for isolation practices in nursing.
AB - Attitudes have changed drastically over the centuries towards people with
infections and how to contain them. Only as we approach the end of the 20th
century are we starting to base our practices on scientific evidence and not on
ritual, although rational thought is still not found in many practices and
confusion surrounds the terminology used. With the introduction of clinical
governance, and the statutory duty of health organizations to provide a quality
service for patients supported by evidence-based practice, this article discusses
isolation practices.
PMID- 10670313
TI - Ethics and nursing research. 1: Development, theories and principles.
AB - This article, the first of two looking at nursing ethics and research, outlines
the foundations and development of an ethical framework for nursing research. The
two dominant theories of ethics--utilitarianism and deontology--are described as
they relate to the rights of individuals undergoing the research. Each of these
approaches has limitations and in some instances choosing the right action may be
difficult. The guiding ethical standards of beneficence/non-maleficence, respect
for human dignity, justice, informed consent and vulnerable subjects are reviewed
for the reader as they relate to undertaking research. This knowledge will help
nurses conduct, participate in, or use research that is based on ethically sound
principles. The second article will explore and explain the relationship between
these guiding principles and the elemental steps of the research process.
PMID- 10670314
TI - Clinical nurses urgently need a career structure.
PMID- 10670315
TI - Cultural competency in nursing.
PMID- 10670316
TI - The skin's antioxidant systems.
AB - The skin is supplied with an antioxidant system that includes enzymatic and
nonenzymatic components. This complex system is the skin's first-line defense
against free-radical attacks. Antioxidants are essential in protecting the
epidermis from damage by free radicals generated both by environmental and
endogenous factors. This role of free radicals in etiology of disease and how
antioxidants are used to offset or prevent oxidative damage are discussed.
PMID- 10670317
TI - Heparin-induced skin necrosis: nurses beware.
AB - As the prophylactic use of heparin continues to increase, nurses must be aware
that heparin use may cause heparin-induced skin necrosis--a rare but serious
complication. Although even more severe complications may occur from heparin use,
this discussion will focus on skin necrosis caused by subcutaneous heparin.
Should heparin-induced skin necrosis develop, heparin therapy must be
discontinued immediately. This case presentation illustrates one patient's
reaction to this complication.
PMID- 10670318
TI - What's your assessment? Nummular eczema with eczema craquele.
PMID- 10670319
TI - Pain management for dermatologic laser surgery: a nursing perspective.
AB - Pain after laser surgery is one of the most commonly experienced patient
problems. It is a pervasive part of laser treatment and a problem with which
nurses and physicians are expected to deal. The nurse's most important role is
preoperative patient teaching. Prior to undergoing the prescribed treatment,
patients must have a realistic understanding of the laser procedure, including
the expected sensations associated with the surgery. Education will not only
correct misconceptions and reduce anxiety, but will also allow patients to play
an active role in their surgery and to optimize fully from pain-reducing
techniques and strategies.
PMID- 10670320
TI - Dermatology nurse certified--now what does that mean?
AB - What is certification and what does it mean to professionalization of dermatology
nursing? The certification process is explored through one personal experience.
Some discussion of the Dermatology Nurses Association's role in professionalism
is included.
PMID- 10670321
TI - A guideline for high-quality patient care.
PMID- 10670322
TI - Autoimmune bullous diseases: diagnosis and management.
AB - Bullous diseases constitute a wide group of disorders in which blistering of the
skin and/or mucous membranes occurs. Patients may develop other lesions in
addition to blisters. It is important for dermatology nurses to understand the
pathogenesis of these disorders, the means for making an accurate diagnosis, and
systemic and local management of the diseases.
PMID- 10670323
TI - The beginnings of dermatology: a brief review.
AB - Dermatology emerged as a distinct medical specialty in the mid-1800s. The
background that led to this development, and the contributions made to the
specialty by pioneering physicians in England, France, the German-speaking
countries, and the United States are discussed.
PMID- 10670324
TI - A review of cutaneous disease in African-American patients.
AB - It is often difficult to determine the role race may play in diagnosis, most
notably in patients with deeply pigmented skin. Among the members of any
population, there are a significant range of skin colors and hair types which
makes generalizing impossible. Deep pigmentation can mask anticipated cutaneous
reactions or predispose to severe postinflammatory hypopigmentation and
hyperpigmentation. It is imperative that professionals in dermatology recognize
reactions in patients with deeply pigmented skin in order to diagnose and treat
effectively.
PMID- 10670325
TI - What's your assessment? Streptococcal sepsis.
PMID- 10670326
TI - Traumatic wound care.
AB - The scope and importance of traumatic wound care, assessment, debridement, pre
and postoperative management, and subsequent skin care during the course of
treatment cannot be over-emphasized, and indeed, are the most important
considerations for functional and cosmetic outcome. Care begins in the emergent
phase and continues through acute and convalescent phases. Efforts are directed
at methods and techniques which prevent infection, facilitate wound healing,
promote comfort, and at the same time, maintain optimal function and minimize
deformities.
PMID- 10670327
TI - Lasers for vascular lesions.
AB - Recent developments in laser technology have revolutionized the treatment of
various cutaneous disorders. Lasers provide effective and safe treatment of many
conditions for which previous therapy was either unavailable, ineffective, or
unacceptable. Basic laser principles, laser safety, available laser systems for
treatment vascular lesions, clinical applications, preoperative considerations,
anesthesia, postoperative changes, side effects/complications, nursing measures,
and patient education are described.
PMID- 10670328
TI - A new treatment option for acne scars: allograft dermis.
AB - Unsightly facial scars resulting from acne can be the source of painful emotional
trauma. A new option for treating acne scars is described. It is pre-packaged
dermal graft material that is easy to use, safe, and effective. A review of
current treatment options and the steps for using this material are presented.
PMID- 10670329
TI - Wound assessment and evaluation. Diabetic neuropathic ulcer.
PMID- 10670330
TI - Patient education for adults with chronic eczema.
AB - Seven patients with severe eczema participated in an individual education
project. The aim of the education program was to maintain and improve health by
providing knowledge in self-care treatment. Patients were provided with new
knowledge of their disease and received sufficient information to enable them to
apply self-care of their eczema.
PMID- 10670331
TI - What's your assessment? The diagnosis is herpes simplex.
PMID- 10670332
TI - Alternative therapies, should we discourage or educate?
PMID- 10670333
TI - Managing atopic dermatitis.
AB - "Itchy" rashes occurring in patients (usually an infant or child) with a personal
and/or family history of itching, sneezing, and/or wheezing should be considered
part of the spectrum of skin problems labeled "atopic dermatitis" (AD). Multiple
factors influence AD, and effective management requires that none be overlooked.
The complicated nature of treatment means parents and family members require
repeated reinforcement and education, particularly in avoiding "triggers of
itch;" and use of medications. When all the aspects of AD are adequately
addressed, more than 90% of patients with AD can be effectively managed.
PMID- 10670334
TI - What's your assessment? Epidermoid inclusion cyst.
PMID- 10670335
TI - Biomedical ethics and the role of the nurse: a case study and discussion.
AB - Ethical issues are becoming of increasing concern to dermatology nurses as they
struggle to maintain their role as patient advocate in the midst of cost
constraints in the health care system. A case study is presented of one such
dilemma. Suggestions are given for keeping nursing principles and advocacy at the
forefront of patient care.
PMID- 10670336
TI - Wound assessment and evaluation. Unstageable pressure ulcer due to eschar
formation.
PMID- 10670337
TI - Update on acne therapy.
AB - Current therapy of acne vulgaris is very effective. It consists of a combination
of topical comedolytic agents, antibacterial agents, and combinations of both.
The use of systemic therapy with antibiotics, isotretinoin, and hormones is
necessary for cystic acne. The management of patients with the various
combinations of topical and systemic medications is discussed.
PMID- 10670338
TI - The soul of managed care.
PMID- 10670339
TI - Patient compliance: an issue for nursing.
PMID- 10670340
TI - Emergency room dermatology.
AB - Dermatologic problems are seen very often in the urgent care setting. Common
acute problems such as urticaria, pruritus, and less common but potentially
devastating dermatologic diseases will be discussed in this review. Emphasis will
be placed on an efficient and cost-effective initial approach to diagnosis and
treatment.
PMID- 10670341
TI - Development of dermatology nursing certification.
AB - In February 1998 the first Dermatology Nursing Certification exam was
administered to registered nurses. This added credential beyond licensure serves
as a demonstration that Dermatology Nurse Certified (DNC) nurses have acquired a
core body of specialized knowledge and adhere to specialized nursing standards.
In addition to providing a sense of professional achievement, certification can
serve other purposes: peer and collegial respect, documentation of advanced
knowledge and skills, increased earning power, increased job satisfaction, and in
the future, third-party reimbursement.
PMID- 10670342
TI - What's your assessment? Impetigo.
PMID- 10670343
TI - Alopecia areata: identification and current treatment approaches.
AB - Alopecia areata is a disease which occurs in 1.7% of the population (Safavi et
al., 1995), often with devastating effects to patients and their families. In the
past, this condition has been misunderstood and treated inadequately. New
treatment modalities and support systems are offering hope to patients with
alopecia areata.
PMID- 10670344
TI - Wound assessment and evaluation. Venous stasis ulceration.
PMID- 10670345
TI - Lymphedema awareness.
PMID- 10670346
TI - Competency in the 21st century.
PMID- 10670347
TI - Health care needs better towers.
PMID- 10670348
TI - The relationship between skin cancer knowledge and preventive behaviors used by
parents.
PMID- 10670349
TI - Brown recluse spider bites.
AB - The bite of the brown recluse spider (BRS) is the most severe arthropod cause of
necrotic skin lesions. The severity of cutaneous injury due to BRS bites vary
from mild erythema to severe necrosis. Rarely, severe systemic reactions occur.
Diagnosis may be difficult, since the victim may not feel the bite or see the
spider. Treatment must be individually tailored. Proper treatment, reassurance,
and rapid followup are helpful in reducing the cutaneous and psychologic
discomfort associated with BRS bites.
PMID- 10670350
TI - Wound assessment and evaluation. Bullous pemphigoid.
PMID- 10670351
TI - What's your assessment? Fixed drug eruption.
PMID- 10670352
TI - Study habits and test-taking tips.
AB - Everyone experiences test anxiety to some degree. Helpful suggestions about how
to reduce test anxiety, how to study for tests, and how to develop good study
habits can reduce this anxiety. Studying is different for different types of
tests. It is important to learn how to study for multiple choice, true/false,
short answer, and essay tests. These skills are also helpful when preparing for a
certification examination such as the Dermatology Nurses Certification Exam. Use
these tips and techniques to become better prepared for tests, and the suggested
methods for reducing anxiety prior to and during tests.
PMID- 10670353
TI - Achieving excellence in health care.
PMID- 10670354
TI - What's wrong with this picture?
PMID- 10670355
TI - Epidermolysis bullosa: a nursing perspective.
AB - Caring for patients affected with epidermolysis bullosa (EB) can be one of the
biggest challenges a dermatology nurse can face. Being familiar with EB and its
associated complications is of utmost importance in caring for those individuals,
otherwise patient care can be compromised. To provide the quality care that these
individuals need, education is required for those affected and their family
members as well as for health care providers involved in their care.
PMID- 10670356
TI - The biopsychosocial burden of genital herpes: evidence-based and other approaches
to care.
AB - Genital herpes, an incurable disease, is increasing in epidemic proportions in
the United States (Eng & Butler, 1997). Updated information on the epidemiology
and psychosocial aspects of genital herpes is necessary to understand the
biopsychosocial burden of living with the disease. Data from both qualitative and
quantitative research are used to support evidence-based and other approaches to
care.
PMID- 10670357
TI - What's your assessment? Bowen's disease.
PMID- 10670358
TI - The diagnosis of skin disease.
AB - While there are certain common features in taking a history and doing a physical
examination, every health care specialty has its own approach to gathering
information. Dermatology is no exception. The purpose of this article is to
outline in some detail the history taking and the physical examination commonly
used to make a dermatologic diagnosis.
PMID- 10670360
TI - Wound assessment and evaluation. Brown recluse spider bite.
PMID- 10670359
TI - Patient education in the long-term management of atopic dermatitis.
AB - Among the various forms of eczema, atopic dermatitis is the most common,
distinctive, and difficult to manage. Educating patients about avoiding flare
factors and proper use of moisturizers along with rational use of topical
corticosteroids is crucial to effective long-term management. Openly reviewing
facts and fallacies about allergies can help keep the focus on necessary skin
care while dealing with patients' allergy concerns. The team approach of
physician and nurse helps clarify confusing issues and maximizes patients'
ability to effectively treat a chronic but controllable condition.
PMID- 10670361
TI - Nursing problems. A study.
PMID- 10670362
TI - Nurses and fight against tuberculosis--II.
PMID- 10670363
TI - The Fifth Central Pay Commission. Salaries and allowances of nursing personnel.
PMID- 10670364
TI - Nursing care of alcoholic liver disease.
PMID- 10670365
TI - A survey on yellow oleander poisoning.
PMID- 10670366
TI - Safe motherhood. A matter of human rights and social justice.
PMID- 10670367
TI - Reproductive child health programme. An approach to reach 'Health for All by 2000
AD'.
PMID- 10670368
TI - Geriatric problems and their management. The nursing perspective.
AB - Geriatric problems and its Nursing care is not like any other speciality which
deals with one group of diseases. Older adults suffer from various disabilities
and diseases. Geriatric group will lose memory power, bearing, eyesight, etc. The
Nurse who deals with geriatric patients is expected to be well versed in all the
aspects. She approaches the patients through Nursing process. She plans and
directs the day-to-day Nursing care according to the situation that arises.
Because of the scientific knowledge and modern techniques acquired by the Nurses
and health care workers they are able to give a fairly comfortable life to the
elderly people.
PMID- 10670369
TI - World Health Day. April 7, 1998. Safe motherhood.
PMID- 10670370
TI - Building partnerships for community health.
PMID- 10670371
TI - The community as main partner in health.
PMID- 10670372
TI - Job stress perception among nurses. The ICU scenario.
PMID- 10670373
TI - Knowledge of urban mothers about high risk conditions during pregnancy. A case
study.
PMID- 10670374
TI - Oxygen therapy for children. Need-based preparation and evaluation of a self
instructional module for staff nurses on care of a child receiving oxygen
therapy.
AB - The present study was carried out with the objectives of determining the learning
needs of Staff Nurses regarding care of children receiving Oxygen Therapy;
finding association between learning needs and selected variables: age, total
years of experience, experience in Paediatric Ward, married with or without
children; determining validity of self-instructional module, on "care of child
receiving Oxygen Therapy", and evaluating the effectiveness of the self
instructional module or SIM. The study was conducted in two phases. A survey
approach was used for Phase-I and one group pre-test post-test design was adopted
for Phase-II. The total sample of the study was 30 Staff Nurses, of 6 months
experience in Paediatric Ward. The findings of the study showed high learning
need status in most of the areas and the Staff Nurses also expressed the
desirable need for learning in detail. It was found that age, total years of
experience, experience in Paediatric Ward and married with or without children
were independent of their learning need. SIM was effective in terms of gain in
knowledge score as well as acceptability and utility scores of Staff Nurses.
PMID- 10670376
TI - The Trained Nurses' Association of India. State SNA advisors list.
PMID- 10670375
TI - Awareness effect on nursing students of planned teaching programmes on AIDS.
PMID- 10670377
TI - Nurse's role in pain management.2.
PMID- 10670378
TI - Hygienic measures by mothers during breast feeding.
PMID- 10670379
TI - Infant and mental health.
PMID- 10670380
TI - Nurses as health educators. A special teachers' day feature.
PMID- 10670381
TI - Nurses' role in pain management.
AB - In the first part of this article (NJI, August, 1998), the author defined 'Pain'
and dwelt on Pain Characteristics, Pain Components, Pain Theories and some
Factors Affecting Pain. In this concluding part she describes other factors and
goes on to deal with the issues regarding assessment of the pain experience and
the aspect of precention of intensification of pain and the Nurses' role in
providing pain relief.
PMID- 10670382
TI - Holistic nursing. From knowledge of disease to knowledge of human beings.
PMID- 10670383
TI - Growth pattern of children between 1 and 3 years.
PMID- 10670384
TI - Nursing service administration for better patient care. A report on the TNAI
Workshop. Trained Nurses' Association of India.
PMID- 10670385
TI - Importance of human relations in nursing.
PMID- 10670386
TI - Shaping future dietetics professionals: what's in it for you?
PMID- 10670387
TI - Institute of Medicine urges Medicare coverage of medical nutrition therapy.
PMID- 10670388
TI - To read or not to read original research articles: it should not be a question.
PMID- 10670389
TI - Foodservice benchmarking: practices, attitudes, and beliefs of foodservice
directors.
AB - OBJECTIVES: To identify foodservice directors' use of performance measures and to
determine their current practices of, and attitudes and beliefs about,
benchmarking. DESIGN: A survey was conducted using a researcher-developed
questionnaire that had been validated in a pilot-test. The questionnaire was
mailed to 600 randomly selected foodservice directors; 247 (41%) responses were
analyzed. SUBJECTS/SETTING: Subjects were foodservice directors in the United
States from 4 categories of foodservice operations: college/university,
correctional, health care, and school. STATISTICAL ANALYSES: Results were
analyzed using descriptive statistics and chi 2 tests to investigate associations
between variables of interest. RESULTS: The most common performance measures used
by foodservice directors were food cost percentage, cost per unit or area of
service, and meals per labor hour. Internal benchmarking had been used by 71% of
the respondents, external benchmarking by 60%, and functional/generic by 25%.
Seventy-seven percent of the respondents thought benchmarking had some or great
importance in their jobs. Category of foodservice operation was associated with
type of benchmarking partner and was related to certain performance measures.
Sixty-one percent of respondents reported needing knowledge and skills about
benchmarking. APPLICATIONS/CONCLUSIONS: Foodservice directors, regardless of
category of foodservice operation, perceive benchmarking as a useful management
tool to improve processes, products and services. Foodservice directors can use
benchmarking to compare their financial performance with that of other
organizations and learn how to improve their facility by examining best-practice
processes of successful organizations.
PMID- 10670390
TI - Computer-based simulations enhance clinical experience of dietetics interns.
AB - OBJECTIVE: To determine the impact of computer-based simulations on the
performance of dietetics interns in initial clinical rotations. DESIGN: Interns
used either a simulation program (Care Planning Simulation System CPSS[) or a
computer-based tutorial (Nutrition Care Planning Tutorial NCPT[) during their
orientation. Performance of these interns on nutrition care skills was evaluated
during their initial clinical rotations. SUBJECTS/SETTING: Participants were 108
dietetics interns from 8 different programs. Each internship had at least 8
interns, and none of the internships awarded a graduate degree. INTERVENTION:
Subjects in the experimental group completed nutrition assessment and care
planning activities for 3 simulated patients. Subjects in the control group
completed a tutorial on assessment and care planning. MAIN OUTCOME MEASURES:
Likert scale ratings of 31 behaviors were recorded by clinical preceptors.
Behavior statements were grouped into 8 categories and average ratings for each
category were determined. STATISTICAL ANALYSIS: Repeated-measures analysis of
variance and linear regression were used to compare performance ratings between
groups. RESULTS: There were no differences in overall evaluations of the
simulation and tutorial groups for the 8-week period. Interns who started
clinical rotations immediately after orientation (CPSS-I and NCPT-I groups) were
rated lower in all categories than those who began their clinical rotations later
(CPSS-D and NCPT-D groups). Maturation and acquisition of general skills likely
influenced ratings of interns with delayed clinical rotations. For most
categories of behavior the rate of improvement in rating scores was greatest for
interns who used CPSS. APPLICATIONS: Computer-based simulations are a promising
supplement to current techniques in didactic instruction and may be useful in
both didactic and practice settings. Computer-based simulations can provide more
varied practice experiences to didactic students and interns in preparation for
more skilled entry-level positions in dietetics.
PMID- 10670391
TI - Genetic taste markers and preferences for vegetables and fruit of female breast
care patients.
AB - OBJECTIVE: To explore links between genetic responsiveness to the bitter taste of
6-n-propylthiouracil (PROP) and self-reported preferences for vegetables and
fruit of female breast care patients. METHODS: PROP tasting was defined by
detection thresholds and by perceived bitterness and hedonic ratings for PROP
solutions. Nontasters, medium tasters, and supertasters were identified by their
PROP thresholds and by the ratio of perceived bitterness of PROP to the perceived
saltiness of sodium chloride solutions. Subjects rated preferences for vegetables
and fruit using 9-point category scales. SUBJECTS/SETTING: A clinical sample of
170 patients with newly diagnosed breast cancer and 156 cancer-free control
subjects were recruited from the University of Michigan Breast Care Center.
STATISTICAL ANALYSES: Principal components factor analysis, one-way analyses of
variance, and Pearson correlations and chi 2 tests were used to analyze taste and
food preference data. RESULTS: Genetic responsiveness to PROP was associated with
lower acceptance of cruciferous and selected green and raw vegetables (P < .05).
Women who reported disliking such foods were medium tasters or supertasters of
PROP. Preference ratings for fruit were unrelated to PROP taster status.
APPLICATIONS/CONCLUSIONS: Women who are PROP tasters may be less likely to comply
with dietary strategies for cancer prevention that emphasize consumption of
cruciferous vegetables and bitter salad greens. Alternatively, PROP-sensitive
women may seek to reduce bitter taste by adding fat, sugar, or salt.
PMID- 10670392
TI - Early adopters of olestra-containing foods: who are they?
AB - OBJECTIVE: To identify the characteristics of people consuming olestra-containing
foods when first introduced at a test-marketing site. DESIGN: Data are from the
Olestra Postmarketing Surveillance Study (OPMSS). After the introduction of
olestra into a large test-marketing site, study participants received 3 follow-up
telephone calls, at 3-month intervals, in which they were questioned about their
diets during the previous month. SUBJECTS/SETTING: 1,007 adults in Indianapolis,
Ind, who participated in a baseline clinic visit (before introduction of olestra
into the food market) and completed at least 2 of 3 follow-up telephone calls
(after the introduction of olestra into the market). STATISTICAL ANALYSES
PERFORMED: Logistic regression was used to examine associations between olestra
consumption and sociodemographic characteristics, health conditions, attitudes
toward health and diet, and health-related behaviors. RESULTS: Olestra
consumption on at least 1 of the follow-up telephone calls was reported by 41.5%
of the study sample, and consumption on 2 or more telephone calls was reported by
20.0% of the sample. Factors associated with early adoption of olestra-containing
foods included white ethnicity, higher education, overweight, absence of
diabetes, attitudes indicative of diet and health concerns (e.g.; perceptions
that there is a strong relationship between diet and disease), and a lower fat
intake. APPLICATIONS/CONCLUSIONS: In spite of the controversy surrounding the
introduction of olestra into the food market persons with attitudes indicative of
diet and health concerns were likely to be early adopters of olestra-containing
foods. Dietitians and other health care providers should inquire about intake
levels of foods with fat substitutes and ensure that these foods are not being
consumed in excessive amounts or being consumed instead of nutrient-dense foods
that are naturally low in fat.
PMID- 10670393
TI - Assessing food selection in a health promotion program: validation of a brief
instrument for American Indian children in the southwest United States.
AB - OBJECTIVE: Brief dietary assessment instruments are needed to evaluate behavior
changes of participants in dietary intervention programs. The purpose of this
project was to design and validate an instrument for children participating in
Pathways to Health, a culturally appropriate, cancer prevention curriculum.
DESIGN: Validation of a brief food selection instrument, Yesterday's Food Choices
(YFC), which contained 33 questions about foods eaten the previous day with
response choices of yes, no, or not sure. Reference data for validation were 24
hour dietary recalls administered individually to 120 students selected randomly.
SUBJECTS: The YFC and 24-hour dietary recalls were administered to American
Indian children in fifth- and seventh-grade classes in the Southwest United
States. STATISTICAL ANALYSES PERFORMED: Dietary recalls were coded for food items
in the YFC and results were compared for each item using percentage agreement and
the kappa statistic. RESULTS: Percentage agreement for all items was greater than
60%; for most items it was greater than 70%, and for several items it was greater
than 80%. The amount of agreement beyond that explained by chance (kappa
statistic) was generally small. Three items showed substantial agreement beyond
chance (kappa > or = 0.6); 2 items showed moderate agreement (kappa = 0.40 to
0.59) most items showed fair agreement (kappa = 0.20 to 0.39). The food items
showing substantial agreement were hot or cold cereal, low-fat milk, and mutton
or chile stew. Fried or scrambled eggs and deep-fried foods showed moderate
agreement beyond chances. CONCLUSIONS: Previous development and validation of
brief food selection instruments for children participating in health promotion
programs has had limited success. In this study, instrument-related factors that
apparently contributed to poor agreement between data from the YFC and 24-hour
dietary recall were inclusion of categories of foods vs specific foods; food
knowledge, preparation, and vocabulary, item length, and overreporting of
attractive foods. Collecting and scoring the 24-hour recall data may also have
contributed to poor agreement. Further development of brief instruments for
evaluating changes in children's behavior in dietary programs is necessary.
Factors related to the YFC that need further development may be issues that are
also important in the development of effective, brief dietary assessments for
children as individual clients or patients.
PMID- 10670394
TI - Randomized multicenter trial documenting the efficacy and safety of a lactose
free and a lactose-containing formula for term infants.
AB - OBJECTIVE: To evaluate the efficacy and safety of a new lactose-free infant
formula. DESIGN: Randomized, prospective, double-blind, controlled, outpatient,
multicenter, parallel 12-week trial. SETTING: Ambulatory-care facilities of the
participating centers. SUBJECTS: 137 healthy term infants (approximately 7 days
old at the time of study enrollment). INTERVENTION: Healthy term infants, whose
mothers had decided not to breast-feed, were randomly assigned 1 of the 2 study
formulas. MAIN OUTCOME MEASURES: Weight, length, and occipitofrontal
circumference measurements were obtained at baseline and when the infant was 2,
4, 8, and 12 weeks old. Formula acceptance and tolerance were also assessed at
weeks 2, 4, 8, and 12. Serum albumin concentration, creatirune level, and blood
urea nitrogen were determined at baseline and week 12. Adverse events were
assessed throughout the study. STATISTICAL ANALYSES PERFORMED: Each baseline
anthropometric and laboratory variable was analyzed for comparability between
groups using the Student t test and was also analyzed using a repeated-measures
analysis of variance method. Covariance analysis was applied to the final
laboratory data using the respective baseline data as covariates. Decisions about
equality of mean responses to formula effects were based on the .05 level of
significance in all cases. RESULTS: One hundred four infants completed the study.
No significant differences between the 2 formula groups were noted for any of the
growth and blood parameters. APPLICATIONS: This new formula is an effective and
safe lactose-free nutrition alternative for infants who require such a diet.
PMID- 10670395
TI - Dietitian intervention improves lipid values and saves medication costs in men
with combined hyperlipidemia and a history of niacin noncompliance.
AB - We asked if medical nutrition therapy (MNT) administered by registered dietitians
could lead to beneficial clinical and financial outcomes in men with combined
hyperlipidemia (hypercholesterolemia and hypertriglyceridemia). A retrospective
chart review was conducted on 73 men with combined hyperlipidemia who were being
considered for statin therapy because of a previous history of noncompliance with
niacin therapy. Subjects participated in an 8-week dietitian intervention program
as a qualifying requirement, before statin therapy. Patient records were reviewed
to determine the beginning and ending serum lipid concentrations and the number
and length of dietitian sessions. Complete information was available on 43
subjects, aged 60.7 +/- 10.1 years (mean +/- standard deviation). Total dietitian
intervention time was 169 +/- 19 minutes in 2.7 +/- 0.6 sessions (range = 2 to 4
sessions) during 6.5 +/- 2.2 weeks of MNT (range = 4 to 8 weeks). MNT lowered
levels of total cholesterol 11% (P < .001), low-density lipoprotein cholesterol
9% (P < .001), and triglycerides 22% (P < .0001) and body mass index 2% (P <
.0001); MNT raised high-density lipoprotein cholesterol levels 4%. After
dietitian intervention, only 15 of 30 eligible patients required
antihyperlipidemic medications, which led to an annual cost savings of $27,449.10
or $638.35 per patient. A cost saving of $3.03 in statin therapy was realized for
each dollar spent on MNT. We conclude that an average of 3 individualized
dietitian visits of 1 hour each over an 8-week period has a beneficial effect in
treating patients with combined hyperlipidemia and recommend consideration of MNT
as a cost-effective intervention.
PMID- 10670396
TI - Diabetes training for dietitians: needs assessment, program description, and
effects on knowledge and problem solving.
AB - Recent changes in management and medical nutrition therapy for diabetes mellitus
have produced a need to retrain many practicing dietitians. To meet this need, a
multidisciplinary group experienced in medical nutrition therapy and educational
methods used a formal needs-assessment process to design a new training program.
Sugar is Not a Poison (SNAP): The Dietitian's New Role in Diabetes Management is
a 2 1/2-day program that uses written text, didactic presentation, and exercises
that simulate patient encounters to accomplish 12 learning objectives. Program
evaluations show high levels of participant satisfaction. Mean (+/- standard
deviation) scores on pre- and postests of knowledge and problem solving were 69
+/- 13% and 86 +/- 9%, respectively (P < 0.01). The SNAP program needs
assessment, training methods, and knowledge problem-solving test are relevant to
all types of education programs in clinical dietetics.
PMID- 10670397
TI - Caffeine intake in young children differs by family socioeconomic status.
PMID- 10670398
TI - Serving portion size influences 5-year-old but not 3-year-old children's food
intakes.
PMID- 10670399
TI - Overconcern about thinness in 10- to 14-year-old schoolgirls in Taiwan.
PMID- 10670400
TI - Comparison of body weight and body fat classifications of competitive school-age
club swimmers.
PMID- 10670401
TI - Validity and reliability of qualitative dietary fat index questionnaires: a
review.
PMID- 10670402
TI - Ground ostrich: a comparison with ground beef.
PMID- 10670403
TI - Position of the American Dietetic Association: food irradiation.
AB - Food irradiation has been identified a sa safe technology to reduce the risk of
foodborne illness as part of high-quality food production, processing, handling,
and preparation. Food irradiation's history of scientific research , evaluation,
and testing spans more than 40 countries around the world and it has been
endorsed or support by numerous national and international food and organizations
and professional groups. Food irradiation utilizes a source of ionizing energy
that passes through food to destroy harmful bacteria and other organism. Often
referred to as "cold pasteurization," food irradiation offers negligible loss of
nutrients or sensory qualities in food as it does not substantially raise the
temperature of the food during processing. Food irradiation does not replace
proper food production, processing, handling, or preparation, nor can it enhance
the quality of or prevent contact with foodborne bacteria after irradiation. In
the United States, manufacturers are required to identify irradiated food sold to
consumers with an international symbol (Radura) and and terminology describing
the process on product labels. In addiction, food irradiation facilities are
thoroughly regulated and monitored for worker and environmental safety. Members
of The American Dietetic Association (ADA) and other food, nutrition, and health
professionals have a responsibility to educate consumers, food processors,
manufacturers and retailers about the safety and application of the technology.
When consumers are educated about food irradiation, many prefer irradiated
products because of their increased safety. It is the position of ADA that food
irradiation enhances the safety and quality of the food supply and helps protect
consumers from foodborne illness. The ADA encourages the government, food
manufactures, food commodity groups, and qualified food and nutrition
professionals to work together to educate consumers about this additional food
safety tool and make this choice available in the marketplace.
PMID- 10670404
TI - Case problem: presenting conventional and complementary approaches for relieving
nausea in a breast cancer patient undergoing chemotherapy.
PMID- 10670405
TI - Severe hypophosphatemia. Pathophysiologic implications, clinical presentations,
and treatment.
AB - We conducted this review to heighten the awareness and describe pathologic
manifestations of hypophosphatemia. We present 3 cases of varied manifestations
of hypophosphatemia where recognition was delayed. In certain settings, severe
hypophosphatemia has significant morbidity and potential mortality. Appreciation
of the pathophysiologic basis for organ dysfunction in severe hypophosphatemia
should result in early recognition and treatment. We reviewed the English
language literature for reported cases and research studies dealing with
pathophysiologic mechanisms subserving clinical manifestations. We observed that
depletion of adenosine triphosphate (ATP) would explain most of the derangement
noted in cellular functions. Phosphate plays a key role in the delivery of oxygen
to the tissue. Lack of phosphate, therefore, leads to tissue hypoxia and hence
disruption of cellular function. Severe hypophosphatemia becomes clinically
significant when there is underlying phosphate depletion. Otherwise, short-term
acute hypophosphatemia is not usually associated with any specific disorder.
Chronic hypophosphatemia, on the other hand, results in hematologic,
neuromuscular, and cardiovascular dysfunction, and unless corrected, the
consequences can be grave. Most of the time hypophosphatemia results from renal
loss of phosphate, diagnosed by a fractional secretion of phosphate > 5%. It is
hard to provide precise estimates of how many patients are seen with
hypophosphatemia annually at academic medical centers. This is complicated by use
of chemistry panels that do not measure inorganic phosphate unless specifically
ordered. This often leads to delay in correct diagnosis, and, therefore,
additional delay in providing appropriate management. A high index of suspicion
alone avoids the unnecessary withholding of treatment that can be life saving.
PMID- 10670406
TI - Assessing the effects of thyroid suppression on benign solitary thyroid nodules.
A model for using quantitative research synthesis.
AB - Systematic review of the available information with a modified, largely
quantitative method of research synthesis disclosed that an initial trial of
thyroid hormone suppression therapy leads to clinically significant (> or = 50%)
reduction of nodule size or arrest of nodule growth in a subset of patients with
benign solitary thyroid nodules. In fact, in addition to objective improvements
due to decreasing nodule size, L-T4 suppression therapy may benefit patients by
reducing perinodular thyroid volume. Consequently, both pressure symptoms and
cosmetic complaints may improve (9, 68). Additional studies for the assessment of
the risks versus benefits of supraphysiologic doses of L-T4, the optimal level of
thyroid suppression and the dose needed to achieve this magnitude of reduction,
the optimal length of the initial trial, and the conditions for the continuation
of L-T4 thyroid suppression therapy, as well as the identification of markers for
patients most likely to respond to this therapy, are warranted. Finally,
quantitative assessment of available evidence as described here may be applicable
to the review of other controversial issues as well.
PMID- 10670407
TI - The adult patient with Ebstein anomaly. Outcome in 72 unoperated patients.
AB - Knowledge of the long-term outcome in unoperated adult patients with Ebstein
anomaly is limited, and the therapeutic approach is still controversial. We
studied unoperated adult patients with Ebstein anomaly to define the patterns of
presentation, anatomic characteristics, outcome, and predictive factors for
survival. Seventy-two unoperated survivors of Ebstein anomaly aged over 25 years
attended from 1972 to 1997 were reviewed and followed-up from 1.6 to 22.0 years.
Patients were classified in 3 groups of severity according to the
echocardiographic appearance of the septal leaflet attachment of tricuspid valve.
The mean age at diagnosis was 23.9 +/- 10.4 years, and the most common clinical
presentation was an arrhythmic event (51.4%). There were 30 (42%) deaths,
including 6 from arrhythmia, 12 related to heart failure, 7 sudden, 2 unrelated,
and 3 unascertained. According to Cox regression analysis, predictors of cardiac
related death included age at diagnosis (hazard ratio 0.89 for each year of age,
95% confidence intervals CI[ 0.84-0.94), male sex (3.93, 95% CI, 1.50-10.29),
degree of echocardiographic severity (3.34, 95% CI, 1.78-6.24), and
cardiothoracic ratio > or = 0.65 (3.57, 95% CI, 1.15-11.03). During follow-up,
morbidity was mainly related to arrhythmia and refractory late hemodynamic
deterioration. The magnitude of tricuspid regurgitation, cyanosis, and the New
York Heart Association (NYHA) functional class at time zero were significant risk
factors according to the univariate analysis, but not after multivariable
confrontation. The results of this study suggest that pattern of presentation,
clinical course, and prognosis of unoperated adult patients with Ebstein anomaly
are influenced by several factors. Although the initial symptoms are usually mild
and commonly related to supraventricular arrhythmias, these are not associated
with the long-term outcome. The severity of the morbid anatomy was the main
determinant of survival only in extreme cases, but not in those with mild or
moderate deformations, which are more common in adults. Other independent risk
factors such as cardiothoracic ratio, sex, age at diagnosis, and the
echocardiographic evaluation may help to determine the therapeutic approach.
Adult patients with Ebstein anomaly should not be considered as a simple low-risk
group.
PMID- 10670408
TI - Pyoderma gangrenosum. A comparison of typical and atypical forms with an emphasis
on time to remission. Case review of 86 patients from 2 institutions.
AB - Pyoderma gangrenosum (PG) is an idiopathic, inflammatory, ulcerative disease of
undetermined cause. The diagnosis is based on clinical and pathologic features
and requires exclusion of conditions that produce ulcerations. An atypical
bullous variant (atypical pyoderma gangrenosum, APG) exists with clinical
features similar to those of Sweet syndrome. Because PG is a rare disease, few
large case series have been reported. Pyoderma gangrenosum was first recognized
as a unique disease entity in the first half of the 20th century. Cumulative
knowledge of PG is based on a handful of case series and multiple individual case
reports. To augment that knowledge, we present our experience with a large number
of patients over a significant time. We performed a retrospective analysis of the
medical records of 86 patients with PG who were evaluated and treated over 12
years at 2 university-based dermatology departments. The mean (+/- standard
deviation) age of onset of PG and APG, respectively, was 44.6 +/- 19.7 years and
52.2 +/- 15.3 years. Lower extremity involvement was most common in PG, whereas
upper extremity involvement was most common in APG. Associated relevant systemic
diseases were seen in 50% of patients. Inflammatory bowel disease was the most
common association in patients with PG, whereas hematologic disease or malignancy
was most common in those with APG. Although a few patients were managed with
local measures or nonimmunosuppressive treatment, the majority required oral
corticosteroid therapy, often with systemic immunosuppressive treatment. PG
patients required a mean 11.5 +/- 11.1 months of treatment to achieve remission
compared with 9.0 +/- 13.7 months for patients with APG. Five patients (5.8%) had
disease that was extremely refractory to multiple intensive therapies. The
prognosis and disease associations for PG and APG appear to be different.
Compared with PG, APG is more often associated with hematologic disease or
malignancy, and remits more quickly.
PMID- 10670409
TI - Extrahepatic manifestations associated with hepatitis C virus infection. A
prospective multicenter study of 321 patients. The GERMIVIC. Groupe d'Etude et de
Recherche en Medecine Interne et Maladies Infectieuses sur le Virus de l'Hepatite
C.
AB - From January 1996 to January 1997, 321 patients with an average age of 46 +/- 16
years and chronically infected with hepatitis C virus (HCV) were prospectively
enrolled in a study designed to determine the prevalence of extrahepatic
manifestations associated with HCV infection in a large cohort of HCV patients,
to identify associations between clinical and biologic manifestations, and to
compare the results obtained in human immunodeficiency virus (HIV)-positive
versus HIV-negative subsets. In a cross-sectional study, clinical extrahepatic
manifestations, viral coinfections with HIV and/or hepatitis B virus, connective
tissue diseases, and a wide panel of autoantibodies were assessed. Thirty-eight
percent (122/321) of patients presented at least 1 clinical extrahepatic
manifestation including arthralgia (60/321, 19%), skin manifestations (55/321,
17%), xerostomia (40/321, 12%), xerophthalmia (32/321, 10%), and sensory
neuropathy (28/321, 9%). Main biologic abnormalities were mixed cryoglobulins
(110/196, 56%), thrombocytopenia (50/291, 17%), and the presence of the following
autoantibodies: antinuclear (123/302, 41%), rheumatoid factor (107/280, 38%),
anticardiolipin (79/298, 27%), antithyroglobulin (36/287, 13%) and antismooth
muscle cell (27/288, 9%). At least 1 autoantibody was present in 210/302 (70%) of
sera. By multivariate logistic regression analysis, 4 parameters were
significantly associated with cryoglobulin positivity: systemic vasculitis (p =
0.01, odds ratio OR[ = 17.3), HIV positivity (p = 0.0006, OR = 10.2), rheumatoid
factor positivity (p = 0.01, OR = 2.8), and sicca syndrome (p = 0.03, OR = 0.27).
A definite connective tissue disease was noted in 44 patients (14%), mainly
symptomatic mixed cryoglobulinemia and systemic vasculitis, HIV coinfection (23%)
was associated with 3 parameters: anticardiolipin (p = 0.003, OR = 4.18),
thrombocytopenia (p = 0.01, OR = 3.56), and arthralgia or myalgia (p = 0.017, OR
= 0.23). HIV-positive patients presented more severe histologic lesions (p =
0.0004). Extrahepatic clinical manifestations in HCV patients involve primarily
the skin and joints. The most frequent immunologic abnormalities include mixed
cryoglobulins, rheumatoid factor, antinuclear, anticardiolipin, and
antithyroglobulin antibodies. Cryoglobulin positivity is associated with systemic
vasculitis and rheumatoid factor and HIV positivity. HIV coinfection is
associated with arthralgia or myalgia, anticardiolipin antibodies, and
thrombocytopenia.
PMID- 10670410
TI - Can neurologic manifestations of Hughes (antiphospholipid) syndrome be
distinguished from multiple sclerosis? Analysis of 27 patients and review of the
literature.
AB - Hughes (antiphospholipid) syndrome (APS) can mimic multiple sclerosis (MS). We
analyzed the clinical, laboratory, and imaging findings of MS-like expression in
a cohort of patients with APS in an attempt to identify parameters that might
differentiate the 2 entities. We studied 27 patients who were referred to our
unit with the diagnosis of probable or definite MS made by a neurologist. All
patients were referred to our lupus clinic because of symptoms suggesting an
underlying connective tissue disease, uncommon findings for MS on magnetic
resonance imaging (MRI), atypical evolution of MS, or antiphospholipid antibody
(aPL) positivity. aPL, antinuclear antibody (ANA), anti-dsDNA, and anti
extractable nuclear antigen (ENA) antibodies were measured by standard methods.
MRI was performed in every patient and compared with MRI of 25 definite MS
patients who did not have aPL. An index severity score was calculated based on
the size and number of increased signal intensity areas in MRI. In the past
medical history, 8 patients with primary APS and 6 with APS secondary to systemic
lupus erythematosus (SLE) had had symptoms related to these conditions.
Neurologic symptoms and physical examination of the patients were not different
from those common in MS patients. Laboratory findings were not a useful tool to
distinguish APS from MS. When MRI from APS patients was compared globally with
MRI from MS patients, MS patients had significantly increased severity score in
white matter (p < 0.001), cerebellum (p = 0.035), pons (p < 0.015), and when all
areas were taken together (p < 0.001). Patients with APS had significantly
increased scores in the putamen (p < 0.01). No differences were noticed in the
degree of atrophy. When taken individually, MRI from APS patients could not be
distinguished from MRI from MS patients. Most of the patients with primary APS
showed a good response to oral anticoagulant treatment. In patients with
secondary APS, the outcome was poorer. Hughes syndrome (APS) and MS can be
difficult to distinguish. A careful medical history, a previous history of
thrombosis and/or fetal loss, an abnormal localization of the lesions in MRI, and
the response to anticoagulant therapy might be helpful in the differential
diagnosis. We believe that testing for aPL should become routine in all patients
with MS.
PMID- 10670411
TI - Delta-opioid receptor-mediated increase in cortical extracellular levels of
cholecystokinin-like material by subchronic morphine in rats.
AB - Numerous pharmacological data indirectly support the idea that interactions
between cholecystokinin (CCK) and opioids participate in the development of
tolerance to morphine. Biochemical investigations were performed with the aim of
directly assessing the status of such interactions in morphine treated rats.
Tolerance to the alkaloid after s.c. implantation of morphine pellets for three
days was not associated with any change in the levels of both CCK like-material
(CCKLM) and proCCK mRNA in the frontal cortex. However, microdialysis in the
freely moving rat showed that this morphine treatment produced a significant
increase (+40%) of the cortical spontaneous CCKLM outflow, which could be
completely prevented by intracortical infusion of naloxone (10 microM). The
opioid receptors responsible for morphine-induced cortical CCKLM overflow
appeared to be of the delta type because intracortical infusion of selective
delta-opioid receptor antagonists such as naltriben (10 microM) and 7
benzylidenenaltrexone (10 microM) also prevented the effect of morphine, whereas
CTOP (10 microM), a selective mu-opioid receptor antagonist, and nor
binaltorphimine (10 microM), a selective K-opioid receptor antagonist, were
inactive. These data indicate that morphine tolerance is associated with delta
opioid receptor mediated activation of cortical CCKergic systems in rats.
PMID- 10670412
TI - Pharmacological comparison of P2X receptors on rat coeliac, mouse coeliac and
mouse pelvic ganglion neurons.
AB - Characteristics of P2X receptors on neurons of the rat coeliac, mouse coeliac and
mouse pelvic ganglia have been studied using the whole cell voltage-clamp
technique. Fast application of ATP (100 microM) on to isolated neurons voltage
clamped at -70 mV induced a slowly desensitising inward current in 96% of the
cells tested. Concentration-response curves for ATP yielded EC50 values of 86
microM, 64 microM and 123 microM, for rat coeliac, mouse coeliac and mouse pelvic
ganglion neurons, respectively, while alpha,beta-methylene ATP was inactive. The
response to ATP was antagonised by suramin, Cibacron blue and pyridoxalphosphate
6-azophenyl-2',4'-disulphonic acid (PPADS). The potency of ATP was increased by
extracellular acidification and by co-application of micromolar concentrations of
Zn2+, while raising pH decreased it. On rat coeliac ganglion neurons, the EC50
values for ATP were 35 microM and 253 microM at pH 6.8 and 8.0, respectively. On
mouse coeliac and pelvic ganglion neurons, altering the pH produced comparable
changes. In conclusion, our results indicate that, in contrast to the guinea-pig
coeliac ganglion, the characteristics of the P2X receptors present on rat
coeliac, mouse coeliac and mouse pelvic ganglia are all identical to those
present on rat pelvic ganglion, i.e. they are homomeric P2X2 receptors, or
heteromultimers with P2X2 being the dominant subunit.
PMID- 10670413
TI - The prostaglandin E series modulates high-voltage-activated calcium channels
probably through the EP3 receptor in rat paratracheal ganglia.
AB - The modulation of high-voltage-activated (HVA) Ca2+ channels by the prostaglandin
E series (PGE1 and PGE2) was studied in the paratracheal ganglion cells.
Prostaglandin E1, E2, STA2 (a stable analogue of thromboxane A2), 17-phenyl
trinor-PGE2 (an EP1-selective agonist) and sulprostone (an EP3-selective agonist)
inhibited the HVA Ca2+ current (HVA ICa) dose-dependently, and the rank order of
potency to inhibit HVA Ca2+ channels was sulprostone>PGE2, PGE1>STA2>>17-phenyl
trinor-PGE2. SC-51089 (10(-5) M), a selective EP1-receptor antagonist, showed no
effect on the PGE1- or PGE2-induced inhibition of the HVA ICa, thereby indicating
that PGE1- and PGE2-induced inhibition of the HVA Ca2+ channels is possibly
mediated by the EP3 receptor. The PGE1-sensitive component of the current was
markedly reduced in the presence of omega-conotoxin-GVIA (3x10(-6) M), but not
with nifedipine (3x10(-6) M). PGE1 and PGE2 also inhibited the remaining ICa in a
saturating concentration of nifedipine, omega-conotoxin-GVIA and omega-conotoxin
MVIIC, suggesting that R-type Ca2+ channels are involved. The inhibitory effect
of PGE1 or sulprostone was prevented by pretreatment with pertussis toxin [islet
activating protein (IAP)] or phorbol-12-myristate-13-acetate (PMA), and the
protein kinase C (PKC) inhibitor chelerythrine blocked the action of PMA. It was
concluded that PGE1 selectively reduces both N- and R-type Ca2+ currents by
activating a G-protein probably through the EP3 receptor in paratracheal ganglion
cells.
PMID- 10670414
TI - Dopamine activates inward rectifier K+ channel in acutely dissociated rat
substantia nigra neurones.
AB - The effect of dopamine (DA) was investigated on acutely dissociated rat
substantia nigra pars compacta (SNc) neurones by using patch clamp recording. The
SNc neurones could be classified into two groups. About 75% of large neurones
(>30 microm in diameter) were tyrosine hydroxylase (TH) positive while almost all
small neurones (<20 microm) were TH negative. In the large neurones, DA
hyperpolarized the membrane, resulting in a reduction of the frequency of
spontaneous action potentials in current-clamp mode and induced an inward
rectifier K+ current in voltage-clamp mode. Quinpirole, a D2 receptor agonist,
mimicked the DA action. S(-)-sulpiride, a D2 receptor antagonist, inhibited the
DA-induced current (I(DA)) more effectively than SKF83566, a D1 receptor
antagonist. Intracellular application of either guanosine 5'-O-(2
thiodiphosphate) (GDP-betaS) or pertussis toxin (IAP) suppressed I(DA). Guanosine
5'-O-(3-thiotriphosphate) (GTP-gammaS) sustained the DA response. Modulators for
cAMP such as forskolin and isobutylmethylxathine, H-89, a protein kinase A
inhibitor, and chelerythrine, a protein kinase C inhibitor, had no effect on
I(DA). The frequency of DA-induced single channel currents in the inside-out
patch configuration, for which the unitary conductance was 56.6pS, was greatly
reduced by the replacement of GTP with GDP perfused at the cytosolic side. These
results suggest that DA acts on a D2-like receptor and activates directly an IAP
sensitive G protein coupled with inward rectifier K+ channels, resulting in a
decrease in the spontaneous firing activities of rat SNc dopaminergic neurones.
PMID- 10670415
TI - Sensitivity of native and cloned hippocampal delayed-rectifier potassium channels
to verapamil.
AB - The effects of the phenylalkylamine verapamil on native and cloned hippocampal
voltage-operated potassium channels were investigated. Native channels were
studied in acutely isolated CA1 neurons from the guinea pig with the whole-cell
patch-clamp technique. Cloned channels were expressed in oocytes of Xenopus
laevis and studied with the two-electrode voltage-clamp technique. Native
potassium channels: Verapamil suppressed the potassium currents in micro- and
submicromolar concentrations. The current suppression increased during the
voltage step. The IC50 value of verapamil was 3 micromol/l and the Hill
coefficient was 0.5 indicating a mixed population of potassium channels with
distinct verapamil sensitivity. Cloned potassium channels: The hippocampal
potassium channels Kv1.1, Kv1.2, Kv1.3, Kv2.1, Kv3.1 and Kv3.2 were affected by
verapamil in micromolar concentrations. The effect increased with depolarization
time, was voltage-dependent, reached 90% of the maximum within around 40 s after
start of verapamil application, recovered slowly after wash-out and did not reach
control values even after wash-out times of six minutes. The IC50 values differed
markedly and were 35 micromol/l for the Kv1.1 channel, 98 micromol/l for the
Kv1.2 channel, 12 micromol/l for the Kv1.3 channel, 226 micromol/l for the Kv2.1
channel, 6 micromol/l for the Kv3.1 channel and 11 micromol/l for the Kv3.2
channel.
PMID- 10670416
TI - Neuroprotective effects of an AMPA receptor antagonist YM872 in a rat transient
middle cerebral artery occlusion model.
AB - The neuroprotective effects of YM872 ([2,3-dioxo-7-(1H-imidazol-1-yl)6-nitro
1,2,3,4-tetrahydro-1-quinoxal inyl]acetic acid monohydrate), a novel alpha-amino
3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor antagonist with high
water solubility, were examined in rats with transient middle cerebral artery
(MCA) occlusion. The right MCA of male SD rats was occluded for 3 h using the
intraluminal suture occlusion method. YM872 significantly reduced the infarct
volume 24 hours after occlusion, at dosages of 20 and 40 mg/kg/h (iv infusion)
when given for 4 h immediately after occlusion. Furthermore, delayed
administration of YM872 (20 mg/kg/h iv infusion for 4 h, starting 2 or 3 h after
the occlusion) also reduced the infarct volume and the neurological deficits
measured at 24 h. Additionally, the therapeutic efficacy of YM872 persisted for
at least seven days after MCA occlusion in animals treated with YM872 for 4 h
starting 2 h after MCA occlusion. These data demonstrate that AMPA receptors
contribute to the development of neuronal damage after reperfusion as well as
during ischemia in the focal ischemia models and that the acute effect of the
blockade of AMPA receptors persists over a long time period. YM872 shows promise
as an effective treatment for patients suffering from acute stroke.
PMID- 10670417
TI - Dynamics of NMDAR-mediated neurotoxicity during chronic ethanol exposure and
withdrawal.
AB - We have utilized a hippocampal brain slice explant system to assess cellular and
synaptic mechanisms underlying the expression of alcohol withdrawal
hyperexcitability. Previously, we observed a role for NMDA receptors in the
expression of electrographic seizures (EGS) observed immediately upon withdrawal
from chronic ethanol exposure in this system. One possible cellular mechanism
responsible for these prior results involves NMDAR-mediated neurotoxicity, which
was assessed in the present study. Explants were exposed to 35 or 75 mM ethanol
for 6 or 12 days and incubated with propidium iodide (PI) to label non-viable
cells and then imaged digitally. PI labeling was significantly reduced (36% of
control levels) following chronic ethanol exposure (75 mM). When tested following
ethanol withdrawal, PI labeling remained significantly reduced in the 75 mM
exposed group. We next assessed the effect of an NMDA challenge 24 h following
withdrawal. The 35 mM and 75 mM ethanol exposed groups displayed significant 6
fold and 13-fold NMDAR-mediated increases in PI labeling respectively; control
explants displayed a 3-fold increase. These data suggest that chronic ethanol
exposure prior to withdrawal has a minor neuroprotective effect that slightly
diminishes within 24 h of ethanol withdrawal. Furthermore, the data indicate that
direct NMDAR activation is required for induction of ethanol withdrawal
neurotoxicity.
PMID- 10670418
TI - Chronic modulation of the GABA(A) receptor complex regulates Y1 receptor gene
expression in the medial amygdala of transgenic mice.
AB - NPY exerts anxiolytic effects, which are mediated by activation of Y1 receptors
in the amygdala. It has been shown that diazepam counteracts the anxiogenic
effect of Y1 receptor antagonists, suggesting that NPYergic and GABAergic systems
are coupled in the regulation of anxiety. We used a transgenic mouse model,
expressing a mouse Y1 receptor-beta-galactosidase fusion gene (Y1R/LacZ), to
study the effect of positive or negative modulators of GABA(A) receptors on Y1
receptor gene expression. Mice were treated for 14 days with diazepam (4 or 20
mg/kg), the anxiolytic beta-carboline-derivative abecarnil (0.3 or 6 mg/kg) and
the anxiogenic beta-carboline FG7142 (20 mg/kg). Transgene expression was
determined by quantitative analysis of beta-galactosidase histochemical staining
in the medial amygdala and in the medial habenula as a control region. Chronic
treatment with 20 mg/kg diazepam or 6 mg/kg abecarnil significantly increased,
whereas FG 7142 decreased, transgene expression in the medial amygdala. A
transient decrease in transgene expression was observed in the medial amygdala
six hours after the acute treatment with 20 mg/kg FG 7142 but not with diazepam
or abecarnil. No significant changes were observed in the medial habenula. These
data suggest that modulation of GABA(A) receptor function may regulate Y1
receptor gene expression in medial amygdala.
PMID- 10670419
TI - Loreclezole inhibition of recombinant alpha1beta1gamma2L GABA(A) receptor single
channel currents.
AB - Loreclezole had two different effects on GABA(A) receptor (GABAR) currents. When
applied to GABARs that contained a beta2 or beta3 subunit subtype, but not a
beta1 subtype, loreclezole potentiated the peak current evoked by sub-maximal
concentrations of GABA. Loreclezole also increased the rate and degree of
apparent desensitization of GABAR whole-cell currents, an effect that was
independent of the beta subunit subtype, suggesting that potentiation and
inhibition of GABAR current by loreclezole occurred through separate sites. We
used patch-clamp recording from outside-out and inside-out patches from L929
fibroblasts transiently transfected with rat GABAR subunits to examine the
properties of inhibition of alpha1beta1gamma2L single channel currents by
loreclezole. Loreclezole decreased the mean open time of the channel by
decreasing the average durations of the open states. Loreclezole also increased
the occurrence of a closed component with an average duration near 20 ms.
Inhibition by loreclezole was not voltage-dependent. Loreclezole was equally
effective when applied to the intracellular side of the receptor, suggesting that
its binding site was readily accessible from both sides of the membrane. Pre
application of loreclezole effectively inhibited the GABAR current in
macropatches, indicating that binding did not require an open channel. These
findings were consistent with a mechanism of allosteric modulation at a site
formed by the membrane spanning regions of the receptor.
PMID- 10670420
TI - Impaired inhibition of epileptiform activity by baclofen, but not by adenosine in
the weaver hippocampus.
AB - The weaver defect results in a loss of baclofen- and adenosine-gated K+
conductance in the hippocampus of adult homozygous (wv/wv) mice. In addition,
suppression of hippocampal epileptiform activity by baclofen is impaired
(Jarolimek, W., Baurle, J., Misgeld, U., 1998. Pore mutation in a G protein-gated
inwardly rectifying K+ channel subunit causes loss of K+ dependent inhibition in
weaver hippocampus. Journal of Neuroscience 18, 4001-4007). We used wv/wv and
wild-type (+/+) mice to determine whether K+ conductance increases are essential
for the suppression of epileptiform activity by R-baclofen and adenosine in
disinhibited hippocampal slices. In wv/wv mice R-baclofen was less potent by two
orders of magnitude in reducing the frequency of spontaneous synchronous burst
discharges than in +/+ mice. Endogenous adenosine and adenosine A1 receptor
agonists differed only slightly in their efficacy to inhibit spontaneous
synchronous burst discharges in wv/wv and +/+ mice. The findings on adenosine A1
receptors suggest that the varied efficacy of R-baclofen in wv/wv and +/+ mice
may not be explained solely on the basis of a loss of ligand-gated K+
conductance. Therefore, we investigated the affinity of GABA(B) receptors for the
antagonist CGP55845A in wv/wv and +/+ hippocampi. Schild plot analysis revealed a
K(D) for the GABA(B) antagonist CGP55845A 10 fold higher in wv/wv than in +/+
mice. The data suggest that an alteration of GABA(B) receptors could contribute
to the reduced efficacy of R-baclofen to suppress hippocampal epileptiform
activity in weaver mice, while the suppression by adenosine remains largely
unaffected.
PMID- 10670421
TI - Effects of valproate derivatives I. Antiepileptic efficacy of amides, structural
analogs and esters.
AB - Derivatives of the antiepileptic drug valproate (VPA, 2-propylpentanoic acid)
have been synthesized and tested in order to improve the intracellular
availability of VPA. The buccal ganglia of Helix pomatia were used as a test
nervous system and antiepileptic efficacies were reconfirmed using rat cortex in
vivo. Epileptiform activities consisted of typical paroxysmal depolarization
shifts (PDS) which appeared in the identified neuron B3 with application of
pentylenetetrazol. Epileptiform activities were found to be accelerated,
unaffected or blocked. (i) The Amide-derivatives 2-propylpentanamide and N,N
dipropyl-2-propylpentanamide, and short chain ester derivatives 1-O-(2
propylpentanoyl)-2,3-propandiol, 2,2-di(hydroxymethyl)-1-O-(2-propylpentanoyl)
1,3-propanediol and 2,2-di(hydroxymethyl)-1,3-di-O-(2-propylpentanoyl)-1,3
propanediol accelerated epileptiform activities. Membrane potential often shifted
to a permanent depolarization which corresponded to the PDS-inactivation level.
(ii) The structural analogs 1-cycloheptene-1-carboxylic acid and
cyclooctanecarboxylic acid accelerated epileptiform activities only slightly or
were without effects. (iii) The small VPA-ester, 2-propylpentanoic acid ethyl
ester, decreased the epileptiform activities in a way that is comparable to the
effects of VPA well known from previous studies. It thus could be thought as a
VPA-pro-drug. (iv) The mannitol-esters 1-O-(2-propylpentanoyl)-D-mannitol and
3,4;5,6-Di-O-isopropylidene-1-O-(2-propylpentanoyl)-D-mannitol blocked the PDS in
a way which is different from the known effects of VPA. These substances are
interpreted not to exert their effects after being metabolized to VPA and thus
they are thought to be new antiepileptic substances.
PMID- 10670422
TI - Effects of valproate derivatives II. Antiepileptic efficacy in relation to
chemical structures of valproate sugar esters.
AB - The structure effect relationships of derivatives of the antiepileptically active
ester of valproate (VPA) 3,4:5,6-Di-O-isopropylidene-1-O-(2-propylpentanoyl)-D
mannitol (1) have been studied using intracellular recording to record the
membrane potential of single neurons (buccal ganglia, Helix pomatia).
Epileptiform activity was induced by the epileptogenic drug pentylenetetrazol.
The effects of several derivatives on epileptiform activity were compared with
those of the relay compound 1. Most of the synthesized agents decreased the
duration of paroxysmal depolarization shifts (PDS) and increased their repetition
rate. It was considered that a decreased the duration of PDS is antiepileptic and
an increased repetition rate is pro-epileptic. Compared with the effects of
compound 1, the following relationships were found: (1) Derivatives containing
glucitol or galactitol were of similar antiepileptic potency. (2) Introduction of
pyranoses or furanoses rendered the substances inactive or even pro-epileptic.
(3) VPA in position 1 and 6 at the sugar acted as an antiepileptic whereas in
position 3 and 4 it proved to be ineffective. (4) Replacement of VPA by
ethylhexanoyl reduced the antiepileptic potency slightly and pivaloyl strongly.
(5) Replacement of isopropylidene bridges by penta-O-acetyl or cyclohexylidene
residues led to largely inactive substances. (6) Compounds having isopropylidene
bridges in position 2,4;3,5 proved to be antiepileptic whereas bridges especially
in positions 2,3:4,5 slightly enhanced epileptic activities.
PMID- 10670423
TI - Agonist-stimulated [35S]GTPgammaS binding in brain modulation by endogenous
adenosine.
AB - Coupling of receptors to G-proteins can be assessed by the ability of specific
agonists to stimulate [35S]GTPgammaS binding in both brain membranes and sections
in the presence of excess GDP. In some brain regions, however, high basal
activity makes it difficult to detect agonist-stimulated [35S]GTPgammaS binding.
The present study suggests a modification of the assay to reduce basal
[35S]GTPgammaS binding and thus increase the signal:noise ratio. Adenosine A1
receptors belong to the class of G-protein-coupled receptors that activate Gi/Go
proteins in brain. In the present study, the A1 agonist R(-)N6-(2
phenylisopropyl)adenosine (R-PIA) stimulated [35S]GTPgammaS binding in brain
regions known to contain A1 receptors, including cerebellum, hippocampus and
dentate gyrus, medial geniculate body, superior colliculus, certain thalamic
nuclei, cerebral cortex, piriform cortex, caudate-putamen, and nucleus accumbens.
Treatment of sections and membranes with adenosine deaminase (ADase), which is
typically used in adenosine assays to eliminate endogenous adenosine, reduced
basal [35S]GTPgammaS binding. In addition, for cannabinoid and mu-opioid
agonists, the percent stimulation of [35S]GTPgammaS binding was approximately
doubled when ADase was included in the assay. These results suggest that
endogenous adenosine contributes significantly to basal [35S]GTPgammaS binding in
certain brain regions, and that this activity may be reduced by the addition of
ADase, thus improving the signal:noise ratio of agonist-stimulated [35S]GTPgammaS
binding.
PMID- 10670424
TI - Nicotine-evoked [3H]5-hydroxytryptamine release from rat striatal synaptosomes.
AB - The aim of this study was to characterize the pharmacology of presynaptic
nicotinic cholinoceptors (nAChRs) that modulate release of 5-hydroxytryptamine (5
HT) from superfused rat brain synaptosomes preloaded with [3H]5-HT. Nicotine
increased 5-HT release from striatal synaptosomes (maximally by 15-30%) but not
from cerebral cortex or hippocampal synaptosomes. Release of striatal 5-HT was
increased in a concentration-dependent manner by nicotine, epibatidine, cytisine,
and ACh (with added esterase inhibitor and muscarinic antagonist). Respective
EC50 values were: 0.5, 0.003, 0.1 and 0.7 microM. The maximal effect of each
agonist was virtually completely blocked by a high concentration of the
insurmountable nicotinic antagonist mecamylamine; at a higher concentration of
epibatidine (3 microM), a mecamylamine-insensitive effect was revealed. Nicotine,
ACh and epibatidine appeared equally efficacious, whereas cytisine was of lower
efficacy (60-70% of ACh). Release evoked by a half-maximal concentration of
nicotine was inhibited by the nicotinic antagonists dihydro-beta-erythroidine
(IC50 0.04 microM) and methyllycaconitine (IC50 0.06 microM). Nicotine-evoked 5
HT release was not reduced by tetrodotoxin given in a concentration that blocked
veratridine-evoked release. These findings provide functional evidence for a
direct action of nicotine on 5-HT neurons in the brain. The presynaptic nAChRs
that modulate striatal 5-HT release appear to possess a novel pharmacological
profile.
PMID- 10670425
TI - Anxiogenic effects of nicotine in the dorsal hippocampus are mediated by 5-HT1A
and not by muscarinic M1 receptors.
AB - After direct administration into the dorsal hippocampus nicotine decreased the
time spent in social interaction, without changing locomotor activity, indicating
an anxiogenic effect. The possibility that post-synaptic M1 muscarinic receptors
mediated this effect was examined by determining whether dorsal hippocampal
administration of a specific M1 receptor agonist (McN-A-343) had anxiogenic
effects, and whether the anxiogenic effect of nicotine could be reversed by co
administration of the M1 receptor antagonist, pirenzepine. McN-A-343 (0.3, 1.6,
3.2, 15.8 nmol) was without effect on social interaction, and pirenzepine (0.7
and 2.4 nmol) injection into the dorsal hippocampus failed to reverse the
decrease in social interaction caused by nicotine (6.3 nmol) injection into this
area. However, the decrease in social interaction after nicotine (50 nmol) was
completely reversed by the specific 5-HT1A receptor antagonist, WAY 100635 (0.4
nmol) after co-administration of both drugs into the dorsal hippocampus. Thus,
the anxiogenic effect of nicotine in this brain region seems to be mediated by 5
HT1A, but not M1, receptors. In contrast to the effect of nicotine in naive
animals, those retested after a second injection of 50 nmol did not show a
significant anxiogenic effect. The theoretical implications of this are discussed
and from a practical point of view this suggests caution in the retesting of
animals after central injections.
PMID- 10670426
TI - Exon-intron organization of the human 5-HT3A receptor gene.
AB - The gene structure of the human 5-HT3A receptor gene was analyzed by exon to exon
polymerase chain reaction and subsequent sequencing. The results were confirmed
by restriction analysis and genomic Southern blotting. The coding region of the
human gene was found to be split by eight introns at identical positions as in
the murine 5-HT3A receptor gene. All exon-intron boundaries exhibited fully
conserved splice donor and acceptor consensus sequences. The alternative splice
acceptor in intron eight of the murine gene was not found in the human
counterpart. The length of particular introns differs markedly from the murine
gene. With the exception of intron 5, all human introns are longer than their
murine counterparts. From the start to the stop codon the human gene stretches
over about 14.5 kb. The human exon sequences confirm one of three published human
5-HT3A receptor cDNA sequences. Knowledge of the gene structure, including 1.9 kb
of the 5' noncoding region, all introns and the exon-intron boundaries of the
human 5-HT3A receptor gene should facilitate investigation of its potential role
in psychiatric disorders.
PMID- 10670427
TI - The effect of the NK1 receptor antagonist CP-99,994 on emesis and c-fos protein
induction by loperamide in the ferret.
AB - The site of the anti-emetic action of the neurokinin1 receptor antagonist CP
99,994 was studied in the ferret using the centrally acting opiate receptor
agonist loperamide at a dose (0.5 mg/kg s.c.) which induced emesis in all animals
tested. CP-99,994 (1 mg/kg, s.c.x2) abolished the emetic response (retching and
vomiting) and the behaviours (licking, wet dog shakes, mouth scratching and
gagging) induced by loperamide over a 2-h observation period. The enantiomer of
this compound CP-100,263 (1 mg/kg, s.c.x2) did not have any significant effect on
emesis or related behaviours. Loperamide (0.5 mg/kg s.c.) administration (but not
its vehicle) resulted in dense fos-like immunoreactivity (FLI) mainly throughout
the rostro-caudal extent of the nucleus tractus solitarius but not the area
postrema. Although CP-99,994 (1 mg/kgx2) abolished the loperamide-induced emesis,
it did not have any statistically significant effect on FLI in the brainstem. In
loperamide and CP-100,263 (1 mg/kg, s.c.x2) treated animals FLI was comparable to
that in animals treated with loperamide and CP-99,994. The results from this
study taken together with those from previous studies indicate that loperamide
exerts its emetic effect via nucleus tractus solitarius dendrites projecting into
the area postrema. The lack of significant effect of CP-99,994 on the FLI induced
by loperamide in this nucleus suggests that it is acting at a site "deep" in the
nucleus tractus solitarius or elsewhere. The marked reduction in behaviours
associated with loperamide administration by CP-99,994 provides a preliminary
indication that NK1 receptor antagonist (as represented by CP-99,994) may in the
clinic have effects on behaviours induced by emetic agents in addition to their
previously described effects on retching and vomiting.
PMID- 10670428
TI - Rolipram suppresses experimental autoimmune neuritis and prevents relapses in
Lewis rats.
AB - Rolipram, a phosphodiesterase type 4 inhibitor, can markedly down-regulate
antigen-driven T cell proliferation and suppress TNF-alpha production in vitro
and in vivo. Here we report the effects of Rolipram on experimental autoimmune
neuritis (EAN), which can be induced by immunization with myelin components of
the peripheral nervous system (PNS) combined with Freund's complete adjuvant
(FCA), and which represents a CD4+ T cell-mediated animal model for human
Guillain-Barre syndrome. EAN induced in Lewis rats by inoculation with the PNS P2
protein peptide 57-81 and FCA was strongly suppressed by Rolipram administered
twice daily intraperitoneally from day 9 post immunization (p.i.), i.e. after
onset of clinical EAN. Suppression of EAN was associated with down-regulated
myelin antigen-induced T cell responses as well as down-regulated IFN-gamma and
TNF-alpha production. A relapse of clinical EAN occurred upon treatment of a
short duration (7 days), while prolongation of treatment resulted in the
prevention of clinical EAN relapse. There was no relationship between clinical
EAN relapse and high levels of TNF-alpha. The immunomodulatory effects of
Rolipram call for further research into the potential role of drugs acting on the
immune system in the treatment of autoimmune diseases.
PMID- 10670429
TI - A unique hormonal and behavioral hyporesponsivity to both forced novelty and d
amphetamine in periadolescent mice.
AB - The identification of critical ontogenetic periods of increased vulnerability to
the effects of drugs of abuse could have a great psychobiological and clinical
therapeutical importance. Potential age-related differences in the response of
the hypothalamic-pituitary-adrenal (HPA) axis to both stress and psychostimulants
has been tested here in an animal model of adolescence. Periadolescent (PND 33
43) and Adult (PND>60) mice of both sexes were injected with d-amphetamine (AMPH,
0, 2, or 10 mg/kg i.p.) and immediately faced with a mild psychological stress
experience, i.e. placement in a novel environment. A detailed time-course
analysis of both hormonal and behavioral profiles was performed, with animals
being sacrificed for trunk-blood collection at different time-points during the
test (before the injection, NT group; 15, 30, or 120 min after the injection).
Basal corticosterone (CORT) levels (NT group) were consistently higher in
periadolescents than in adults. As a whole, a marked increment of blood CORT
levels was found in mice of both ages exposed to forced novelty. However,
important age-related differences were also observed, with Saline-injected
periadolescents still exhibiting elevated levels of locomotion at the end of the
120-min test session and failing to show the increasing profile of CORT release
over the baseline that was typical of adults. Upon an AMPH 2 administration,
periadolescents exhibited a much lower profile of locomotor hyperactivity than
adults, and also failed to show an increase across the course of the session in
CORT release, that was observed in adults. When treated with the high AMPH 10
dose, a marked locomotor hyperactivity was found in periadolescents, which
however showed much lower levels of the stereotyped licking and gnawing behavior,
that was typical of adults. The present results suggest a unique profile of
integrated behavioral and physiological hyporesponsivity in mice during
periadolescence. The latter also represents a very useful model for the study of
the issue of psychobiological risk factors involved in vulnerability to drugs of
abuse in human adolescents.
PMID- 10670430
TI - Involvement of tyrosine kinase in the pyrogenic fever exerted by NOS pathways in
organum vasculosum laminae terminalis.
AB - Nitric oxide synthase (NOS) is an enzyme which has a distinct cytokine-inducible
isoform (iNOS). Many cytokine receptors have an intracellular tyrosine kinase
domain. Here we have used two tyrosine kinase inhibitors (genistein and
lavendustin A) to investigate the potential role of tyrosine kinase activation in
the induction on both iNOS and fever caused by lipopolysaccharide (LPS) in
rabbits. Direct administration of LPS into the organum vasculosum laminae
terminalis (OVLT) increased iNOS expression. These increases paralleled the
increase in deep body temperature in unanesthetized rabbits. Pretreatment with
genistein or lavendustin A not only reduced the fever but also attenuated the
iNOS expression in the OVLT following an intra-OVLT dose of LPS. These results
suggest that tyrosine phosphorylation is part of the signal transduction
mechanism that mediates the induction of both iNOS and fever elicited by LPS in
the OVLT of rabbit brain.
PMID- 10670431
TI - Developmental neuroplasticity in a model of cerebral hemispherectomy and stroke.
AB - Cerebral hemispherectomy, a last resort treatment for childhood epilepsy, is a
standard procedure which dramatically illustrates the resilience of the brain to
extensive damage. If this operation, also mimicking long-term, extensive
unilateral capsular stroke, is performed in postnatal cats of up to 60 days of
age, there is a remarkable recovery/sparing of neurological functions that is not
seen when the lesion occurs during late fetal life or in adulthood. A long-term
effect at all ages is loss of neurons in bilateral brain areas remote from the
resection site. This is pronounced in adult cats and shows intriguing,
paradoxical features in fetal animals, but is substantially attenuated in
neonatal cats. Similarly, large-scale reinnervation of subcortical sites
(sprouting) by neurons of the remaining, intact hemisphere is prominent in young
cats, but not in fetal or adult animals. These and other restorative processes
(described herein) in young postnatal animals are matched by relatively higher
rates of local cerebral glucose utilization, supporting the notion that they
underlie the improved behavioral outcome. Thus, during a critical, defined stage
of maturation, presumably common to higher mammals including humans, the brain
entirely remodels itself in response to extensive but focal injury. Perhaps the
molecular environment allowing for rescue of neurons and enhanced reinnervation
at a specific developmental stage could be recreated in subjects with brain
lesions at less favorable ages, thereby helping to restore circuitry and spare
neurons. However, replacement via transplantation of neurons eliminated by the
damage appears to be crucial in attempts to further preserve cells located
remotely but yet destined to die or decrease in size. This article presents
abundant evidence to show that there is a surprisingly comprehensive long-term
morphological remodeling of the entire brain after extensive unilateral damage
and that this occurs preferentially during a discrete period of early life.
Additional evidence strongly suggests that the remodeling underlies the
outstanding behavioral and functional recovery/sparing following early cerebral
hemispherectomy. We argue that this period of reduced brain vulnerability to
injury also exists in other higher mammals, including man, and suggest ways to
enhance restorative processes after stroke/hemispherectomy occurring at other
ages.
PMID- 10670432
TI - Impaired neurotransmitter release and elevated threshold for cortical spreading
depression in mice with mutations in the alpha1A subunit of P/Q type calcium
channels.
AB - The P/Q type voltage-gated Ca2+ channels are involved in membrane excitability
and Ca2+-dependent neurotransmitter release within the CNS. Mutations in the
CacnalA gene encoding the alpha1A subunit of the P/Q type Ca2+ channel have
recently been reported in tottering mice and a more severely affected allele,
leaner. Here we show using in vivo cortical microdialysis that evoked increases
of extracellular glutamate levels are markedly attenuated in both mutants upon
KCl-induced depolarization compared with wild-type mice. Tottering and leaner
mice also show a 10-fold resistance to cortical spreading depression induced by
cortical electrical stimulation or KCl application to the pial surface. A slower
transcortical propagation speed and failure to sustain regenerative spread of the
depolarizing wave were more pronounced in leaner neocortex. Both signaling
defects appeared unrelated to the developmental history of repeated cortical
spike-wave discharges, since neither were observed in the stargazer mouse, a Ca2+
channel gamma2 subunit mutant with a similar seizure phenotype. These data
demonstrate two cortical excitability defects revealed by prolonged
depolarization in cerebral networks expressing mutant P/Q type Ca2+ channels, and
are the first to identify a gene linked to a spreading depression phenotype.
PMID- 10670433
TI - The medial prefrontal cortex plays an important role in the excitation of A10
dopaminergic neurons following intravenous muscimol administration.
AB - Intravenous muscimol administration increases the activity of dopaminergic
neurons of the A10 cell group, located in the ventral tegmental area. Evidence
suggests that this increase in activity is produced by disinhibition following
the inhibition of GABAergic ("non-dopaminergic") cells in the ventral tegmental
area. We hypothesized that the activation of A10 cells by muscimol is likely to
be at least partly caused by the action of excitatory afferents. To verify this,
A10 cells were isolated from ipsilateral afferent sources which utilise
excitatory amino acids (which play an important role in the activity of these
neurons), using hemisections at the level of the subthalamic nucleus (or just
anterior to the subthalamic nucleus), electrolytic lesions of the
pedunculopontine tegmental nucleus, or a combination of both. Following
hemisections, and hemisections combined with lesions of the pedunculopontine
tegmental nucleus, muscimol inhibited rather than excited A10 dopaminergic
neurons. The pedunculopontine tegmental nucleus itself appeared to make little
intrinsic contribution to muscimol-induced excitation, although the results
suggested that part of the excitation which originates in the forebrain may be
conducted to A10 cells via the pedunculopontine tegmental nucleus. The source of
the effective forebrain excitation was investigated using electrolytic lesions of
documented sources of excitatory amino acidergic afferents to the ventral
tegmental area: the medial prefrontal cortex, certain nuclei of the amygdalar
complex and the lateral habenular nucleus. In the medial prefrontal cortex
lesioned group, muscimol again produced inhibition, an effect qualitatively and
quantitatively similar to that in the hemisected groups. Habenular lesions
blocked muscimol-induced excitation without producing inhibition, whilst
amygdalar lesions produced no significant change in the effects of muscimol. The
results suggest that under normal circumstances, an active excitation counteracts
and exceeds the direct inhibitory effects of muscimol on the activity of A10
dopaminergic neurons. Furthermore, this activation appears to be produced by the
action of excitatory (probably excitatory amino acidergic) afferents arising from
the medial prefrontal cortex, and possibly the lateral habenular nucleus. Insofar
as the excitation of A10 dopaminergic neurons, which is produced by certain drugs
of abuse, and which may play a crucial role in their sustained use, has its basis
in excitation following disinhibition, this excitation may provide a novel target
for therapeutic intervention in addiction.
PMID- 10670434
TI - Sensorimotor cortical influences on cuneate nucleus rhythmic activity in the
anesthetized cat.
AB - This work aimed to study whether the sensorimotor cerebral cortex spreads down
its rhythmic patterns of activity to the dorsal column nuclei. Extracellular and
intracellular recordings were obtained from the cuneate nucleus of chloralose
anesthetized cats. From a total of 140 neurons tested (106 cuneolemniscal), 72
showed spontaneous rhythmic activity within the slow (< 1 Hz), delta (1-4 Hz),
spindle (5-15 Hz) and higher frequencies, with seven cells having the delta
rhythm coupled to slow oscillations. The spindle activity recorded in the cuneate
was tightly coupled to the thalamo-cortico-thalamic spindle rhythmicity.
Bilateral or contralateral removal of the frontoparietal cortex abolished the
cuneate slow and spindle oscillations. Oscillatory paroxysmal activity generated
by fast electrical stimulation (50-100 Hz/1-2 s) of the sensorimotor cortex
induced burst firing synchronized with the paroxysmal cortical "spike" on all the
non-lemniscal neurons, and inhibitory responses also coincident with the cortical
paroxysmal "spike" in the majority (71%) of the cuneolemniscal cells. The
remaining lemniscal-projecting neurons showed bursting activity (11%) or
sequences of excitation-inhibition (18%) also time-locked to the cortical
paroxysmal "spike". Additionally, the cerebral cortex induced coherent
oscillatory activity between thalamic ventroposterolateral and cuneate neurons.
Electrolytic lesion of the pyramidal tract abolished the cortically induced
effects on the contralateral cuneate nucleus, as well as on the ipsilateral
medial lemniscus. The results demonstrate that the sensorimotor cortex imposes
its rhythmic patterns on the cuneate nucleus through the pyramidal tract, and
that the corticocuneate network can generate normal and abnormal patterns of
synchronized activity, such as delta waves, spindles and spike-and-wave
complexes. The cuneate neurons, however, are able to generate oscillatory
activity above 1 Hz in the absence of cortical input, which implies that the
cerebral cortex probably imposes its rhythmicity on the cuneate by matching the
intrinsic preferred oscillatory frequency of cuneate neurons.
PMID- 10670435
TI - Cytotoxic lesion of the medial prefrontal cortex abolishes the partial
reinforcement extinction effect, attenuates prepulse inhibition of the acoustic
startle reflex and induces transient hyperlocomotion, while sparing spontaneous
object recognition memory in the rat.
AB - The partial reinforcement extinction effect refers to the increase in resistance
to extinction of an operant response acquired under partial reinforcement
relative to that acquired under continuous reinforcement. Prepulse inhibition of
the acoustic startle response refers to the reduction in startle reactivity
towards an intense acoustic pulse stimulus when it is shortly preceded by a weak
prepulse stimulus. These two behavioural phenomena appear to be related to
different forms of attentional processes. While the prepulse inhibition effect
reflects an inherent early attentional gating mechanism, the partial
reinforcement extinction effect is believed to involve the development of
acquired inattention, i.e. the latter requires the animals to learn about what to
and what not to attend. Impairments in prepulse inhibition and the partial
reinforcement extinction effect have been independently linked to the
neuropsychology of attentional dysfunctions seen in schizophrenia. The proposed
neural substrates underlying these behaviourial phenomena also appear to overlap
considerably: both focus on the nucleus accumbens and emphasize the functional
importance of its limbic afferents, including that originating from the medial
prefrontal cortex, on accumbal output/activity. The present study demonstrated
that cytotoxic medial prefrontal cortex lesions which typically damaged the
prelimbic, the infralimbic and the dorsal anterior cingulate areas could lead to
the abolition of the partial reinforcement extinction effect and the attenuation
of prepulse inhibition. The lesions also resulted in a transient elevation of
spontaneous locomotor activity. In contrast, the same lesions spared performance
in a spontaneous object recognition memory test, in which the lesioned animals
displayed normal preference for a novel object when the novel object was
presented in conjunction with a familiar object seen 10 min earlier within an
open field arena. The present results lend support to the hypothesis that medial
prefrontal cortex dysfunction might be related to some forms of attentional
abnormality central to the symptomatology of schizophrenia. Relevance of the
present findings in relation to the neural substrates underlying the partial
reinforcement extinction effect and prepulse inhibition is further discussed.
PMID- 10670436
TI - Orbital cortex neuronal responses during an odor-based conditioned associative
task in rats.
AB - Neuronal activity in the rat orbital cortex during discrimination of various
odors [five volatile organic compounds (acetophenone, isoamyl acetate,
cyclohexanone, p-cymene and 1,8-cineole), and food- and cosmetic-related odorants
(black pepper, cheese, rose and perfume)] and other conditioned sensory stimuli
(tones, light and air puff) was recorded and compared with behavioral responses
to the same odors (black pepper, cheese, rose and perfume). In a
neurophysiological study, the rats were trained to lick a spout that protruded
close to its mouth to obtain sucrose or intracranial self-stimulation reward
after presentation of conditioned stimuli. Of 150 orbital cortex neurons recorded
during the task, 65 responded to one or more types of sensory stimuli. Of these,
73.8% (48/65) responded during presentation of an odor. Although the mean breadth
of responsiveness (entropy) of the olfactory neurons based on the responses to
five volatile organic compounds and air (control) was rather high (0.795), these
stimuli were well discriminated in an odor space resulting from multidimensional
scaling using Pearson's correlation coefficients between the stimuli. In a
behavioral study, a rat was housed in an equilateral octagonal cage, with free
access to food and choice among eight levers, four of which elicited only water
(no odor, controls), and four of which elicited both water and one of four odors
(black pepper, cheese, rose or perfume). Lever presses for each odor and control
were counted. Distributions of these five stimuli (four odors and air) in an odor
space derived from the multidimensional scaling using Pearson's correlation
coefficients based on behavioral responses were very similar to those based on
neuronal responses to the same five stimuli. Furthermore, Pearson's correlation
coefficients between the same five stimuli based on the neuronal responses and
those based on behavioral responses were significantly correlated. The results
demonstrated a pivotal role of the rat orbital cortex in olfactory sensory
processing and suggest that the orbital cortex is important in the manifestation
of various motivated behaviors of the animals, including odor-guided motivational
behaviors (odor preference).
PMID- 10670437
TI - Identification of two persistently activated neurotrophin-regulated pathways in
rat hippocampus.
AB - Brain-derived neurotrophic factor contributes profoundly to modulate activity
dependent synaptic plasticity in adult brain areas such as the hippocampus, but
the mechanisms underlying this important role still remain unclear. Recently, we
have shown that two serine/threonine kinases, calcium/calmodulin-dependent
protein kinase-2 and casein kinase-2, are capable of mediating brain-derived
neurotrophic factor responses in adult rat hippocampus. In the present study,
using hippocampal slices from adult rat, we show that phospholipase C-regulated
calcium signals couple the brain-derived neurotrophic factor receptor to two
distinct pathways: a pathway in which calcium/calmodulin-dependent protein kinase
2 stimulates a signalling module involving the p38 subfamily of mitogen-activated
protein kinases and its downstream target, usually named mitogen-activated
protein kinase-activated protein kinase-2; and a pathway in which the
extracellular signal-regulated kinase subfamily of mitogen-activated protein
kinases activates casein kinase-2. Our results suggest that: (i) extracellular
signal-regulated kinase is activated by B-Raf in response to a calcium-sensitive
adenylate cyclase; and (ii) extracellular signal-regulated kinase activates
casein kinase-2 via a protein phosphatase(s) that may be of the PP1 and/or PP2A
type. Interestingly, we also show that neurotrophin-induced activation of the two
signalling cascades promotes a sustained activation of mitogen-activated protein
kinase-activated protein kinase-2 and casein kinase-2 in slices. Considering the
ability of these two kinases to be persistently activated, and that most of the
protein kinases which lie in these pathways are believed to be important for
multiple events underlying neuronal plasticity, it is suggested that the
mechanisms described here might contribute both to rapid synaptic changes through
local effects and to long-lasting synaptic responses through new gene
transcription in the hippocampus.
PMID- 10670438
TI - The histological validation of post mortem magnetic resonance imaging-determined
hippocampal volume in Alzheimer's disease.
AB - For 11 AD cases and four normal elderly controls, post mortem volumes of the
hippocampal subdivisions were calculated by using magnetic resonance imaging and
histological sections. After at least six weeks of fixation in formalin, brains
were examined on a 1.5-T Philips Gyroscan imager producing T1-weighted coronal
images with a 3-mm slice thickness. Brains were then processed and embedded in
paraffin. Serial coronal sections, 3 mm apart and stained with Cresyl Violet,
were used for the planimetry and unbiased estimation of the total numbers of
neurons in the hippocampal subdivisions. For all 15 cases, magnetic resonance
imaging- and histology-based measurements were performed along the whole
rostrocaudal extent of the hippocampal formation and included three subvolumes:
(i) the hippocampus (CA1-CA4 and the dentate gyrus); (ii) hippocampus/subiculum;
and (iii) hippocampus/parahippocampal gyrus. After controlling for shrinkage,
strong correlations were found between magnetic resonance imaging and
histological measurements for the hippocampus (r = 0.97, P < 0.001),
hippocampus/subiculum (r = 0.95, P < 0.001) and hippocampus/parahippocampal gyrus
(r = 0.89, P < 0.001). We also calculated the total number of neurons in the
hippocampus and hippocampus/subiculum subvolumes. Strong correlations between the
magnetic resonance imaging subvolumes and neuronal counts were found for the
hippocampus (r = 0.90, P < 0.001) and the hippocampus/subiculum subvolume (r =
0.84, P < 0.001). We conclude that very accurate volumetric measurements of the
whole hippocampal formation can be obtained by using a magnetic resonance imaging
protocol. Moreover, the strong correlations between magnetic resonance imaging
based hippocampal volumes and neuronal numbers suggest the anatomical validity of
magnetic resonance imaging volume measurements.
PMID- 10670439
TI - The effect of insulin and glucose on the plasma concentration of Alzheimer's
amyloid precursor protein.
AB - The deposition of beta amyloid is a critical event in the pathogenesis of
Alzheimer's disease. This peptide is a metabolite of the amyloid precursor
protein. Recent research suggests that there is a correlation between plasma
insulin and glucose concentrations and memory performance in Alzheimer's disease
sufferers. Additionally, in vitro evidence suggests that both insulin and glucose
may affect the metabolism of amyloid precursor protein and therefore the
production of beta amyloid--however, to our knowledge no in vivo data have yet
been published. We investigated the effect of elevated plasma levels of glucose
and insulin on the plasma concentration of amyloid precursor protein in non
Alzheimer's disease subjects. As would be expected following ingestion of a
glucose drink, blood insulin and glucose levels significantly increased.
Interestingly, however, plasma amyloid precursor protein concentration decreased.
Whilst no correlation was observed between insulin or glucose levels and plasma
amyloid precursor protein concentration, the decrease in plasma amyloid precursor
protein concentration was affected by the apolipoprotein E genotype of the
subject. Possession of an epsilon4 allele resulted in a reduced decrease in
plasma amyloid precursor protein in response to glucose ingestion when compared
to non-epsilon4 subjects. We conclude that glucose ingestion, and the subsequent
elevation of plasma levels of glucose and insulin leads to a decrease in plasma
amyloid precursor protein concentration. Further studies are required to
determine the clinical significance of these physiological changes in plasma
amyloid precursor protein and the implications for Alzheimer's disease
pathogenesis.
PMID- 10670440
TI - Status epilepticus results in an N-methyl-D-aspartate receptor-dependent
inhibition of Ca2+/calmodulin-dependent kinase II activity in the rat.
AB - Status epilepticus is a major medical emergency that results in significant
alteration of neuronal function. Status epilepticus involves seizure activity
recurring frequently enough to induce a sustained alteration in brain function.
This study was initiated to investigate how status epilepticus affects the
activity of calcium and calmodulin-dependent kinase II in the brain. Calcium and
calmodulin-dependent kinase II is a neuronally enriched signal transducing system
involved in the regulation of neurotransmitter synthesis and release,
cytoskeletal function, gene transcription, neurotransmitter receptor function and
neuronal excitability. Therefore, alteration of this signal transduction system
would have significant physiological effects. Status epilepticus was induced in
rats by pilocarpine injection, allowed to progress for 60 min and terminated by
repeated diazepam injections. Animals were killed at specific time-points and
examined for calcium and calmodulin-dependent kinase II activity. Calcium and
calmodulin-dependent kinase II activity was significantly reduced in cerebral
cortex and hippocampal homogenates obtained from status epilepticus rats when
compared with control animals. Once established, the status epilepticus-induced
inhibition of calcium and calmodulin-dependent kinase II activity was observed at
all time-points tested following the termination of seizure activity. However,
calcium and calmodulin-dependent kinase II activity was not significantly
decreased in thalamus and cerebellar homogenates. In addition, status epilepticus
induced inhibition of calcium and calmodulin-dependent kinase II activity was
dependent upon activation of N-methyl-D-aspartate subtype of glutamatergic
receptors. Thus, status epilepticus induced a significant inhibition of calcium
and calmodulin-dependent kinase II activity that involves N-methyl-D-aspartate
receptor activation. The data support the hypothesis that inhibition of calcium
and calmodulin-dependent kinase II activity may be involved in the alteration of
neuronal function following status epilepticus.
PMID- 10670441
TI - Ca2+ channels that activate Ca2+-dependent K+ currents in neostriatal neurons.
AB - It is demonstrated that not all voltage-gated calcium channel types expressed in
neostriatal projection neurons (L, N, P, Q and R) contribute equally to the
activation of calcium-dependent potassium currents. Previous work made clear that
different calcium channel types contribute with a similar amount of current to
whole-cell calcium current in neostriatal neurons. It has also been shown that
spiny neurons possess both "big" and "small" types of calcium-dependent potassium
currents and that activation of such currents relies on calcium entry through
voltage-gated calcium channels. In the present work it was investigated whether
all calcium channel types equally activate calcium-dependent potassium currents.
Thus, the action of organic calcium channel antagonists was investigated on the
calcium-activated outward current. Transient potassium currents were reduced by 4
aminopyridine and sodium currents were blocked by tetrodotoxin. It was found that
neither 30 nM omega-Agatoxin-TK, a blocker of P-type channels, nor 200 nM
calciseptine or 5 microM nitrendipine, blockers of L-type channels, were able to
significantly reduce the outward current. In contrast, 400 nM omega-Agatoxin-TK,
which at this concentration is able to block Q-type channels, and 1 microM omega
Conotoxin GVIA, a blocker of N-type channels, both reduced outward current by
about 50%. These antagonists given together, or 500 nM omega-Conotoxin MVIIC, a
blocker of N- and P/Q-type channels, reduced outward current by 70%. In addition,
the N- and P/Q-type channel blockers preferentially reduce the
afterhyperpolarization recorded intracellularly. The results show that calcium
dependent potassium channels in neostriatal neurons are preferentially activated
by calcium entry through N- and Q-type channels in these conditions.
PMID- 10670442
TI - The immunophilin ligand FK506, but not GPI-1046, protects against neuronal death
and inhibits c-Jun expression in the substantia nigra pars compacta following
transection of the rat medial forebrain bundle.
AB - The immunophilin ligand FK506 (Tacrolimus) is used for prevention of graft
rejection following organ transplantation. FK506 is a high-affinity ligand for
FK506-binding proteins, an immunophilin subgroup of peptidyl-prolyl-cis/trans
rotamases abundant in the mammalian brain. Here, we demonstrate that FK506 is a
potent survival factor that prevents neuronal cell death following axotomy of
central intrinsic neurons. Administration of FK506 (2 mg/kg, s.c., per day for
two days pre-axotomy and for up to eight days post-axotomy) effectively delayed
and reduced the death of axotomized neurons in the substantia nigra pars compacta
following transection of the medial forebrain bundle. In saline-treated controls,
75%, 89% and 92% of nigral neurons died after 25, 50 and 60 days post-axotomy,
respectively. In contrast, application of FK506 resulted in survival of 46%, 44%
and 28% of the axotomized nigral neurons, and the majority of these surviving
neurons showed continuous expression of tyrosine hydroxylase, the pacemaker
enzyme for dopamine synthesis. Moreover, FK506 significantly reduced the
expression of the inducible transcription factor c-Jun and its N-terminal
phosphorylation and prevented the axotomy-induced suppression of the constitutive
transcription factor ATF-2 in neurons of the substantia nigra and mammillary
body. The latter is also axotomized by the coincident transection of the
mammillothalamic tract, but the mammillary neurons survive the axotomy. In
contradistinction to FK506, the non-immunosuppressive FK506-binding protein
ligand GPI-1046 (25 or 12.5 mg/kg, applied once or twice per day for two days pre
axotomy and for eight days post-axotomy) was completely ineffective for all these
parameters investigated. Finally, FK506, but not GPI-1046, impressively
accelerated the recovery from surgery. Our data provide the first evidence that
FK506 acts as a neuroprotective molecule that rescues axotomized otherwise
degenerating central intrinsic neurons in the adult mammalian brain by mechanisms
that interfere with the transcriptional program of the axotomy-induced cell body
response, such as activating transcription factor-2 suppression and c-Jun
expression and phosphorylation.
PMID- 10670443
TI - Serotonergic transmission in the periaqueductal gray matter in relation to
aversive behaviour: morphological evidence for direct modulatory effects on
identified output neurons.
AB - Intracellular recordings were made from 21 cells in the dorsolateral
periaqueductal gray matter in coronal midbrain slices. In the majority (n = 20)
bath application of 5-hydroxytryptamine (30 or 150 mM) evoked either
hyperpolarizing (n = 11) or depolarizing (n = 9) responses. Reconstructions of 11
neurons in the dorsolateral periaqueductal gray matter after filling with
biocytin revealed a population of output neurons whose axons followed a
dorsolateral trajectory towards the perimeter of the ipsilateral periaqueductal
gray matter. In seven cells, the axon could be followed into the adjacent
mesencephalic reticular formation. At the light microscopic level, immunostaining
for 5-hydroxytryptamine revealed immunoreactive processes throughout the
dorsolateral periaqueductal gray matter but no labelled somata or dendrites.
Close associations (i.e. no discernible gap) were observed between serotonergic
profiles and the somata and dendrites of biocytin-filled cells. At the
ultrastructural level, serial sections through 21 appositions on to biocytin
filled dendrites in three slices revealed 19 true appositions (i.e. having
closely parallel plasma membranes with no intervening glial cell profiles) with
the biocytin-filled dendrite. Only four of the appositions (21%) showed evidence
of synaptic specializations which included aggregations of synaptic vesicles, and
some thickening of the apposing membrane. The dense reaction product in the
biocytin-filled cells precluded identification of the ultrastructure of
postsynaptic elements. However, examination of contacts between 5
hydroxytryptamine-immunoreactive profiles and unlabelled elements in material
taken from the contralateral side of the periaqueductal gray matter (i.e. no
biocytin present) or in material taken from perfusion-fixed whole brain, in which
ultrastructural preservation was superior compared with slices, revealed a
similar incidence (21% and 23%, respectively) of synaptic specializations. The
data indicate that serotonergic transmission on to output neurons in the
dorsolateral periaqueductal gray matter is largely mediated by non-junctional
contacts, suggesting that the actions of 5-hydroxytryptamine on these cells are
mediated predominantly by volume rather than wiring transmission.
PMID- 10670444
TI - Activation of the parapyramidal region in the ventral medulla stimulates gastric
acid secretion through vagal pathways in rats.
AB - Neurons synthesizing thyrotropin-releasing hormone, substance P and serotonin in
the medullary caudal raphe nuclei project to the dorsal vagal complex and play a
role in the central vagal regulation of gastric function. Neurons in the
parapyramidal region in the ventral medulla share similar biochemical coding and
projections as those in the caudal raphe nuclei. The role of the parapyramidal
region in the autonomic regulation of gastric acid secretion was investigated in
urethane-anesthetized rats. Unilateral microinjection of kainate into the
parapyramidal region at 10, 15 and 20 ng induced a dose-related stimulation of
gastric acid secretion (net increases: 22.2+/-11.2, 40.5+/-8.5 and 89.8+/-19.4
micromol/60 min, respectively), while injection of vehicle had no effect (net
change: -0.1+/-1.4 micromol/60 min). Time-course studies showed a nine-fold peak
increase over basal at 30 min after parapyramidal injection of kainate (20 ng)
and acid secretion returned to basal level at 70 min. Microinjections of kainate
(15-20 ng) outside the parapyramidal region or into the parapyramidal region in
vagotomized rats had no effect. Exposure to cold (4 degrees C) for 2 h, which is
known to induce vagally mediated gastric secretory and motor responses through
medullary thyrotropin-releasing hormone pathways, increased the number of Fos
positive cells in the caudal, middle and rostral parts of the parapyramidal
region to 4.3+/-0.4, 9.4+/-0.9 and 18.4+/-1.6/section, respectively, compared
with 0.1+/-0. 1, 0.1+/-0.0 and 0.7+/-0.6/section, respectively, in rats
maintained at room temperature. Most of the Fos-labeled cells co-expressed pro
thyrotropin-releasing hormone messenger RNA signal and/or were serotonin
immunoreactive. These data show that chemical activation of neurons in the
parapyramidal region results in a vagal-dependent stimulation of gastric acid
secretion and that acute cold exposure activates parapyramidal neurons containing
pro-thyrotropin-releasing hormone and/or serotonin, suggesting a potential role
of the parapyramidal region, in addition to the caudal raphe nuclei, as medullary
sites involved in the vagal regulation of gastric function.
PMID- 10670445
TI - Characterization of spinal amino acid release and touch-evoked allodynia produced
by spinal glycine or GABA(A) receptor antagonist.
AB - Intrathecal strychnine (glycine antagonist) or bicuculline (GABA(A) antagonist)
yields a touch-evoked agitation that is blocked by N-methyl-D-aspartate receptor
antagonism. We examined the effects of intrathecal strychnine and bicuculline on
touch-evoked agitation and the spinal release of amino acids. Fifty-two Sprague
Dawley rats were prepared under halothane anesthesia with a lumbar intrathecal
catheter and a loop dialysis catheter. Four days after implantation, rats were
randomized to receive an intrathecal injection of N-methyl-D-aspartate (3
microg), strychnine (3 microg) or bicuculline (10 microg), or a combination of N
methyl-D-aspartate with bicuculline or strychnine. The agitation produced by
brief light tactile stroking of the flank (tactile allodynia), and the
spontaneous spinal release of glutamate, taurine and serine was measured.
Intrathecal N-methyl-D-aspartate, strychnine and bicuculline produced similar
touch-evoked allodynia. Intrathecal bicuculline and N-methyl-D-aspartate alone
evoked a transient spinal release of glutamate and taurine, but not serine, in
the 0- 10 min sample, while strychnine did not affect spinal transmitter release
at any time. As GABA(A) but not glycine receptor inhibition at equi-allodynic
doses increases glutamate release, while the allodynia of both is blocked by N
methyl-D-aspartate receptor antagonism, we hypothesize that GABA(A) sites
regulate presynaptic glutamate release, while glycine regulates the excitability
of neurons postsynaptic to glutamatergic terminals.
PMID- 10670446
TI - Evaluation of the activity of a novel metabotropic glutamate receptor antagonist
(+/-)-2-amino-2-(3-cis and trans-carboxycyclobutyl-3-(9-thioxanthyl)propionic
acid) in the in vitro neonatal spinal cord and in an in vivo pain model.
AB - The cyclobutylglycine (+/-)-2-amino-2-(3-cis and trans-carboxycyclobutyl-3-(9
thioxanthyl)propionic acid) (LY393053) has been identified as a functionally
potent metabotropic glutamate receptor antagonist. It is most potent on the two
group I metabotropic glutamate receptors, 1alpha and 5alpha, with IC50 values of
1.0+/-0.4 microM and 1.6+/-1.4 microM, respectively. In this study, LY393053 has
also been evaluated electrophysiologically on native group I metabotropic
glutamate receptors in an in vitro spinal cord preparation as well as
behaviourally, in a mouse model of visceral pain. LY393053 dose-dependently
antagonised group I agonist, (RS)-3, 5-dihydroxyphenylglycine, or a broad
spectrum agonist (1S,3R)-amino-1,3-cyclopentanedicarboxylic acid-induced
depolarisation of spinal motoneurons. The apparent Kd values were estimated to be
0.3 microM against (RS)-3, 5-dihydroxyphenylglycine-induced depolarisation and
0.5 microM against (1S,3R)-amino-1,3-cyclopentanedicarboxylic acid-induced
depolarisation, respectively. On the other hand, the dorsal root-ventral root
potential elicited at 8 x threshold was depressed by LY393053 with IC50 values of
9.0+/-0.7 microM and 12.7+/-1.7 microM on monosynaptic and polysynaptic
responses, respectively. When investigated using the mouse acetic acid writhing
test, LY393053 showed significant analgesic effects at doses of 1-10 mg/kg
intraperitoneally. An ED50 value of 6.0 mg/kg was obtained in this test. By
revealing a potent effect of LY393053 in antagonising the native group I
metabotropic receptor-mediated responses in the spinal cord in rodents, and an
antinociceptive efficacy in a mouse visceral pain model, these results,
therefore, provide additional evidence in support of the analgesic potential of
metabotropic glutamate receptor antagonists.
PMID- 10670447
TI - Sensory thresholds and the antinociceptive effects of GABA receptor agonists in
mice lacking the beta3 subunit of the GABA(A) receptor.
AB - A line of mice was recently created in which the gabrb3 gene, which encodes the
beta3 subunit of the GABA(A) receptor, was inactivated by gene-targeting. The
existence of mice with a significantly reduced population of GABA(A) receptors in
the CNS enabled an investigation of the role of GABA and GABA(A) receptors in
nociception. The present study examined the sensory thresholds of these mice, as
well as the antinociceptive effects of subcutaneously or intrathecally
administered GABA(A) and GABA(B) receptor agonists. Homozygous null (beta3-/-)
mice displayed enhanced responsiveness to low-intensity thermal stimuli in the
tail-flick and hot-plate test compared to C57BL/6J and 129/SvJ progenitor strain
mice, and their wild-type (beta3+/+) and heterozygous (beta3+/-) littermates. The
beta3-/- mice also exhibited enhanced responsiveness to innocuous tactile stimuli
compared to C57BL/6J, 129/SvJ and to their beta3+/+ littermates as assessed by
von Frey filaments. The presence of thermal hyperalgesia and tactile allodynia in
beta3-/- mice is consistent with a loss of inhibition mediated by presynaptic and
postsynaptic GABA(A) receptors in the spinal cord. As expected, subcutaneous
administration of the GABA(A) receptor agonist 4,5,6,7-tetrahydroisoxazolo-(5,4
c)pyridin-3-ol did not produce antinociception in beta3-/- mice, whereas it
produced a dose-dependent increase in hot-plate latency in C57BL/6J, 129/SvJ,
beta3+/+ and beta3+/- mice. However, the antinociceptive effect of the GABA(B)
receptor agonist baclofen in the tail-flick and hot-plate tests was also reduced
in beta3-/- mice compared to the progenitor strains, beta3+/+ or beta3+/- mice
after either subcutaneous or intrathecal administration. This finding was
unexpected and suggests that a reduction in GABA(A) receptors can affect the
production of antinociception by other analgesic drugs as well.
PMID- 10670448
TI - Antinociceptive effects of the neuroactive steroid, 3alpha-hydroxy-5alpha-pregnan
20-one and progesterone in the land snail, Cepaea nemoralis.
AB - Results of investigations with vertebrates have implicated neuroactive steroids
and in particular 5alpha-reduced metabolites of progesterone such as 3alpha
hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THP/3A5P and originally
allopregnanolone) in the rapid modulation of diverse functions including that of
nociceptive sensitivity. These effects have been indicated to involve modulation
of GABA receptors. Results of recent phylogenetic studies have revealed the
presence of GABA receptors in invertebrates that may also be subject to
modulation by steroids and neuroactive steroids. The present study examined the
effects of the neuroactive steroid, 3alpha-hydroxy-5alpha-pregnan-20-one, as well
as progesterone on aversive thermal (nociceptive) responses in a mollusc, the
land snail, Cepaea nemoralis. 3alpha-Hydroxy-5alpha-pregnan-20-one had
significant dose-related (0.01-1.0 microg) antinociceptive effects in Cepaea
increasing the latency of response to a 40 degrees C surface, with maximum
effects being evident 15-30 min after administration. These effects of 3alpha
hydroxy-5alpha-pregnan-20-one were stereospecific, with the stereoisomer 3beta
hydroxy-5alpha-pregnan-20-one (3B5P) failing to affect nociceptive responses.
Progesterone also had significant dose-related (0.10-10 microg) antinociceptive
effects that, however, were delayed in onset and relatively prolonged (60-120
min), suggestive of the formation of active metabolites. The presence of
endogenous progesterone (12.36+/-0.17 ng/g tissue) was ascertained by a
radioimmunoassay further supporting a functional role for steroids in Cepaea. The
antinociceptive effects of 3alpha-hydroxy-5alpha-pregnan-20-one and progesterone
were blocked by the GABA antagonists, bicuculline and picrotoxin, while being
relatively insensitive to opioid and N-methyl-D-aspartate antagonists. These
results suggest an early evolutionary development and phylogenetic continuity of
neuroactive steroid and GABA involvement in the mediation of nociception.
PMID- 10670449
TI - Tachykinin receptor inhibition and c-Fos expression in the rat brain following
formalin-induced pain.
AB - Recent pharmacological evidence has implicated substance P and neurokinin A,
natural ligands for neurokinin-1 and neurokinin-2 receptors, respectively, as
neurotransmitters in brain neuronal circuits activated upon noxious stimulation.
The expression of the inducible transcription factor, c-Fos, was used to identify
areas in the brain activated by a noxious stimulus (the subcutaneous injection of
formalin), and to investigate the effects of intracerebroventricular
administration of selective, nonpeptide antagonists for neurokinin-1 and
neurokinin-2 tachykinin receptors on the neural activity in these areas and on
the behavioural response to formalin-induced pain. Formalin (5%, 50 microl),
injected subcutaneously through a chronically implanted catheter in the region of
the lower hindlimb, increased c-Fos expression in a number of brain areas related
to nociceptive transmission or the integration of stress responses. Grooming
behaviour, licking and biting directed to the injected site, was the most
frequent behavioural response. Intracerebroventricular pretreatment of rats with
either RP 67580 (500 pmol), the active enantiomer of a neurokinin-1 receptor
antagonist, or with SR 48968 (500 pmol), the active enantiomer of a neurokinin-2
receptor antagonist, reduced the formalin-induced c-Fos staining in the
prefrontal cortex, dorsomedial and ventromedial nuclei of the hypothalamus, the
locus coeruleus and the periaqueductal gray. The neurokinin-1, but not the
neurokinin-2, receptor antagonist attenuated the formalin-induced activation of c
Fos in the paraventricular nucleus of the hypothalamus. Simultaneous
intracerebroventricular pretreatment with both neurokinin-1 and neurokinin-2
receptor antagonists did not produce any additional inhibitory effect on the post
formalin c-Fos expression. None of the tachykinin receptor antagonists had an
effect on the formalin-induced c-Fos expression in the septohypothalamic nucleus,
medial thalamus, parabrachial nucleus and central amygdaloid nucleus, indicating
that neurotransmitters other than neurokinins are most probably responsible for
the activation of these areas in response to noxious stimulation. While both
tachykinin receptor antagonists reduced the grooming behaviour to formalin, the
neurokinin-1 receptor antagonist was clearly more effective than the neurokinin-2
receptor antagonist. Intracerebroventricular pretreatment of rats with the
inactive enantiomers of the tachykinin receptor antagonists, RP 68651 and SR
48965, was without effect. Our results show that (i) the modified formalin test
elicited an intense grooming behaviour and expression of c-Fos in numerous
forebrain and brainstem areas, (ii) both tachykinin receptor antagonists were
able to attenuate the behavioural response to pain and to reduce the formalin
induced c-Fos expression in some, but not all, brain areas, and (iii) the
neurokinin-1 antagonist, RP 67580, was more effective in inhibiting the
behavioural response to formalin and the pain-induced activation of c-Fos than
the antagonist for neurokinin-2 receptors, SR 48968, indicating that neurokinin-1
receptors are preferentially activated in neurokinin-containing pathways
responding to noxious stimuli. Our results demonstrate that blockade of brain
tachykinin receptors, especially of the neurokinin-1 receptor, reduces the
behavioural response to pain and the pain-induced c-Fos activation in distinct
brain areas which are intimately linked with nociceptive neurotransmission and
the initiation and integration of central stress responses. Together with the
previous findings of the inhibition of hypertensive and tachycardic responses to
pain, the present data indicate that tachykinin receptor antagonists can
effectively inhibit the generation of an integrated cardiovascular and
behavioural response pattern to noxious stimuli.
PMID- 10670450
TI - Heme oxygenase-1, heme oxygenase-2 and biliverdin reductase in peripheral ganglia
from rat, expression and plasticity.
AB - The expression of inducible and constitutive heme oxygenase and biliverdin
reductase was studied in normal and cultured peripheral ganglia from adult rats,
using immunocytochemistry and in situ hybridization. Dramatic changes were
induced by one to two days' culturing of dorsal root ganglia, nodose ganglia,
otic ganglia, sphenopalatine ganglia and superior cervical ganglia. An up
regulation of inducible heme oxygenase was found in satellite cells of the
cultured nodose ganglia, dorsal root ganglia, sphenopalatine ganglia and otic
ganglia, whereas only a few satellite cells in the superior cervical ganglia
responded with an increase in inducible heme oxygenase immunoreactivity. In the
superior cervical ganglia inducible heme oxygenase also appeared in a
subpopulation of macrophages. During culturing, expression of inducible heme
oxygenase immunoreactivity also increased in axons and in nerve cell bodies. In
situ hybridization corroborated the immunocytochemical findings, revealing a
strong up-regulation of inducible heme oxygenase messenger RNA in satellite
cells, and less pronounced up-regulation in nerve cell bodies. Constitutive heme
oxygenase immunoreactivity was found in most neurons in all of the ganglia
studied. No significant changes in constitutive heme oxygenase immunoreactivity
could be observed in cultured ganglia. Biliverdin reductase immunoreactivity was
barely detectable in any of the normal ganglia; however, after culturing it
appeared in axons, single nerve cell bodies and nerve cell nuclei. The results
show that inducible heme oxygenase is up-regulated in peripheral ganglia after
axonal injury, and suggest a role for carbon monoxide in cellular signaling and a
requirement for the antioxidant (bilirubin) during the regeneration process.
PMID- 10670451
TI - Selective neuroprotective effects with insulin-like growth factor-1 in phenotypic
striatal neurons following ischemic brain injury in fetal sheep.
AB - Severe perinatal asphyxia can lead to injury and dysfunction of the basal
ganglia. Post insult administration of insulin-like growth factor-1 is
neuroprotective, particularly in the striatum. Insulin-like growth factor-1 is
also known to be a neuromodulator of several types of striatal neurons. The
striatum comprises various phenotypic neurons with a complex neurochemical
anatomy and physiology. In the present study, we examined the specificity of
neuronal rescue with insulin-like growth factor-1 on different striatal neurons.
Bilateral brain injury was induced in near term fetal sheep by 30 min of
reversible carotid artery occlusion. A single dose of 3 microg of insulin-like
growth factor-1 was infused over 1 h into the lateral ventricle 90 min following
ischemia. The histological and immunohistochemical outcome were examined after 4
days recovery using paraffin tissue preparations. Insulin-like growth factor-1
treatment (n = 11) significantly reduced the percentage of neuronal loss in the
striatum compared with the vehicle treated group (n = 10, 28.3+/-5.1% vs 55.5+/
17.3%, P < 0.005). Immunohistochemical studies showed that ischemia resulted in a
significant loss of calbindin-28kd, choline acetyltransferase, parvalbumin,
glutamate acid decarboxylase, neuronal nitric oxide synthase and neuropeptide Y
immunopositive neurons, compared with sham controls. Insulin-like growth factor-1
markedly prevented the loss of calbindin-28kd (n = 7, P < 0.05), choline
acetyltransferase (n = 7, P < 0.05), neuropeptide Y (n = 7, P < 0.05), neuronal
nitric oxide synthase (n = 8, P < 0.05) and glutamate acid decarboxylase (n = 9,
P < 0.05) immunopositive neurons, but failed to protect parvalbumin (n = 6)
immunopositive neurons. The present study indicates that the therapeutic effect
of insulin-like growth factor-1 in the basal ganglia is selectively associated
with cholinergic and some phenotypic GABAergic neurons. These data suggest a
potential role for insulin-like growth factor-1 in preventing cerebral palsy due
to perinatal asphyxia.
PMID- 10670452
TI - Distribution of glutamate and preproenkephalin messenger RNAs following transient
focal cerebral ischemia.
AB - Middle cerebral artery occlusion may result in increased activation of N-methyl-D
aspartate- or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)-type
receptors by glutamate and lead to neuronal cell death. To characterize molecular
events that precede cell death following transient focal ischemia, in situ
hybridization histochemistry was used to measure levels of glutamate receptor
subunit 1 (GluR1), GluR2, GluR3, N-methyl-D-aspartate receptor subunit 1 (NR1)
and preproenkephalin messenger RNAs in adult rats at various recirculation times
(1.5, 3 and 24 h) following a 90-min period of middle cerebral artery occlusion.
At 1.5 and 3 h recirculation, autoradiography showed pronounced but differential
decreases in AMPA, NR1 and preproenkephalin messenger RNA expression throughout
the infarcted ipsilateral striatum. Non-uniform patterns of in situ hybridization
grains emerged such that many striatal neurons were depleted of AMPA and
preproenkephalin messenger RNAs, while others retained control levels. In
cortical regions destined to undergo infarction, GluR2 and NR1 messenger RNAs
were preferentially reduced relative to the contralateral side (to 75+/-8.5% and
66+/-4.5%, respectively); GluR1, GluR3 and preproenkephalin messenger RNAs were
unaltered. At 24 h recirculation, depletion of striatal and cortical messenger
RNAs became less selective. GluR3 and preproenkephalin messenger RNAs were up
regulated in ipsilateral spared regions of the striatum, and GluR1 and GluR2
messenger RNAs increased bilaterally in the cingulate cortex and in selective
nuclei of the amygdala. Histological cell death or neurodegeneration was not
detected in areas of reduced glutamate and preproenkephalin messenger RNA
expression in either the ipsilateral striatum or cortex before 24 h. These
findings suggest that complex and long-lasting decreases in messenger RNA
expression occur prior to significant cell loss in regions destined to undergo
infarction. Increased formation of Ca2+-permeable AMPA receptor assemblies may
occur in "unspared" and "spared" regions via different mechanisms and contribute
to alterations in post-ischemic synaptic activity. The possibility arises that
there may be altered relationships between glutamatergic and enkephalin synapses,
since the dorsolateral striatum, where preproenkephalin messenger RNA expression
is acutely reduced, receives innervation by the affected ipsilateral cortical
region.
PMID- 10670454
TI - Patterns of developmental expression of the RNA editing enzyme rADAR2.
AB - To date, two structurally related RNA-editing enzymes with adenosine deaminase
activity have been identified in mammalian tissue: ADAR1 and ADAR2 [Bass B. I. et
al. (1997) RNA 3, 947-949]. In rodents, ADAR2 undergoes alternative RNA splicing,
giving rise to two splice variants that differ by the presence or absence of a 10
amino-acid insert in the carboxy-terminal catalytic domain. However, the
physiological significance of the splicing and its regional and developmental
regulation are as yet unknown. The present study examined spatial and temporal
patterns of ADAR2 gene transcripts within specific neuronal populations of rat
brain. The two rodent ADAR2 isoforms were expressed at comparable levels at all
ages examined. rADAR2 messenger RNA expression was first detectable in the
thalamic nuclei formation at embryonic day E19. The rADAR2b insert and rADAR2a
splice probes produced images similar to that of the rADAR2 pan probe. At birth,
rADAR2a messenger RNA splice variants were abundantly expressed in the thalamic
nuclei. No signal for any probe was detectable in other brain regions, including
neocortex, hippocampus, striatum and cerebellum at this stage of development.
During the first week of postnatal life, rADAR2 messenger RNA expression
(detected with the pan probe) increased gradually in several brain regions, with
low expression detected at postnatal day P7 in the olfactory bulb, inferior
colliculus, and within the pyramidal and granule cell layers of the hippocampus.
Hybridization patterns of the rADAR2a variant probe reached peak expression at
about the second week of life, while peak expression of the rADAR2b probe was
reached at about the third week of life. At the end of the first week of life
(P7), expression of both splice variants was strongest in the thalamic nuclei. By
P14, rADAR2 messenger RNA expression was more consolidated in the deeper
structures, including the thalamic nuclei and the granule cell layer of the
cerebellum. By P21, maximal levels of rADARb expression were observed in the
thalamic nuclei, inferior colliculus, cerebellum and pontine nuclei. In the
adult, rADAR2 messenger RNA expression was of highest intensity in the thalamic
nuclei, with high levels of expression in the olfactory bulb, inferior
colliculus, cerebellum and pontine nuclei. At the level of the hippocampus,
positive labelling was restricted to the CA3 region of the Ammon's horn and the
dentate gyrus, with weak signals in the CA1 subfield. rADAR2 pan expression was
at near background levels throughout the neocortex and caudate putamen. In
summary, our study shows that ADAR2 messenger RNA expression is regulated in a
cell-specific manner throughout development. At early ages, ADAR2 messenger RNA
is expressed only within (and restricted to) the thalamic nuclei. By the third
postnatal week, expression of the editase enzyme is more widely distributed
throughout the olfactory bulb, CA3 and dentate gyrus of the hippocampus,
thalamus, inferior colliculus and the molecular cell layer of the cerebellum.
ADAR2 is thought to act at specific nucleotide positions in primary transcripts
encoding glutamate receptor subunits, thereby altering gating and ionic
permeability properties of AMPA- and kainate-activated channels. ADAR2 also acts
at pre-messenger RNA encoding the serotonin 5HT-2C receptor to alter G-protein
coupling. Thus, RNA editing may be an important mechanism for fine-tuning of the
physiological and pharmacological properties of transmitter receptors of the
central nervous system.
PMID- 10670453
TI - Induction of gap junctional intercellular communication, connexin43 expression,
and subsequent differentiation in human fetal neuronal cells by stimulation of
the cyclic AMP pathway.
AB - Expression of gap junction proteins and cell-cell communication was studied in
the human neural-glial cell line, SVG, as a first step in defining whether the
SVG cells could be used as a model system to study the role of gap junctions in
neuronal precursor cells. SVG cells were found to express connexin43 protein that
co-migrated with WB-F344 rat liver connexin43 and that reacted with connexin43
specific antibodies on Western blots. However, fluorescence recovery after
photobleaching analysis of 5,6-carboxyfluorescein-loaded cells failed to show
significant dye coupling. Agents that stimulate the adenylyl cyclase/cAMP pathway
were used to induce gap junctional intercellular communication in the SVG
cultures. A 24-48 h treatment of SVG cells with 5 microM forskolin or 5 microM
forskolin + 200 microM 3-isobutyl-1-methylxanthine increased the percentage of
dye-coupled cells from 5-65%, using the fluorescent recovery after photobleaching
method. The increase in dye coupling induced by forskolin or forskolin + 3
isobutyl-1-methylxanthine was inhibited by octanol, which is known to block gap
junction-mediated cell communication. Western blot analysis of total protein
extracts revealed the appearance of a higher molecular weight connexin43 protein
band after treatment of SVG cells with forskolin or forskolin + 3-isobutyl-1
methylxanthine, that was not observed in vehicle-treated controls. Alkaline
phosphatase treatment of total protein extracts from forskolin or forskolin + 3
isobutyl-1-methylxanthine-treated cells reduced the higher molecular weight band
to approximately 41,000 the same as observed in the control extracts. The
alkaline phosphatase treatment demonstrates that the higher molecular weight band
was due to a phosphorylation event stimulated by forskolin or the forskolin + 3
isobutyl-1-methylxanthine combination. In addition, treatment of the SVG cells
with the forskolin or forskolin + 3-isobutyl-l-methylxanthine stimulated
outgrowth of neurite-like processes from the cell body which immunostained
positive for the connexin43 protein as well as protein markers for neurons and
oligodendrocytes. We hypothesize that the SVG cells may represent a neuronal
progenitor cell population that has the ability to differentiate when exposed to
the appropriate signals.
PMID- 10670455
TI - Immunolabeling of the rat central nervous system with antibodies partially
selective of the short form of the 5-HT3 receptor.
AB - Polyclonal antibodies were raised against a synthetic hexadecapeptide
corresponding to the portion of the second intracytoplasmic loop of the short
form of the mouse 5-hydroxytryptamine-3A receptor subunit (5-HT3A-S), which
differs from the long form (5-HT3A-L) by the removal of six amino acids.
Antibodies were detected by enzyme-linked immunosorbent assay as soon as two
months after the first injection to rabbits of the peptide coupled to keyhole
limpet hemocyanin. Immunoblot detection of fusion proteins comprising glutathione
S-transferase and the second intracellular loop of 5-HT3A-S or 5-HT3A-L, and
immunoprecipitation of cloned receptors showed that antibodies exhibited some
selectivity for the short variant. Affinity chromatography allowed the
purification of selective anti-5-HT3A-S antibodies which yielded a strong
positive labeling of plasma membrane, reticulum and Golgi apparatus of COS-7
cells expressing murine 5-HT3A-S. In contrast, COS-7 cells expressing similar
levels of 5-HT3A-L exhibited only a very weak labeling. Selectivity was also
observed on immunoblots of cloned receptors transiently expressed in COS-7 cells,
or stably expressed in CHO cells, both systems showing an immunolabeled component
at 53,000-54,000 mol. wt. Immunoautoradiographic labeling of central nervous
system sections showed that 5-HT3A-S-like immunoreactivity was found mostly
within the nucleus of the solitary tract, the nucleus of the spinal tract of the
trigeminal nerve, and the dorsal horn of the the spinal cord in the rat. After
unilateral ablation of the nodose ganglion, 5-HT3A-S-like immunoreactivity
decreased markedly in the ipsilateral part of the nucleus of the solitary tract,
as expected of the presynaptic localization of 5-HT3 receptors. Finally,
immunohistochemistry at the light and electron microscope levels revealed that 5
HT3A-S-like immunoreactivity was associated essentially with terminals and axonal
profiles. All these results demonstrate that the immunolabeling exhibited by
these antibodies is consistent with a specific and partially selective
recognition of the short isoform of the 5-HT3A subunit. Because the pattern of
immunoautoradiographic labeling matches the distribution previously established
with selective radioligands, it can be inferred that these antibodies probably
recognized the same fully assembled form of the 5-HT3A-S receptor subunit.
PMID- 10670456
TI - Immunolocalization of the arachidonic acid and mechanosensitive baseline traak
potassium channel in the nervous system.
AB - TRAAK is the sole member of the emerging class of 2P domain K+ channels to be
exclusively expressed in neuronal cells. TRAAK produces baseline K+ currents
which are strongly stimulated by arachidonic acid and by mechanical stretch, and
which are insensitive to the classical K+ channel blockers tetraethylammonium,
Ba2+, and Cs+. This report describes the immunolocalization of TRAAK in brain,
spinal cord, and retina of the adult mouse. The most striking finding is the
widespread distribution of the TRAAK immunoreactivity, with a prominent staining
of the cerebellar cortex, neocortex, hippocampus, dentate gyrus, subiculum, the
dorsal hippocampal commissure, thalamus, caudate-putamen, olfactory bulb, and
several nuclei in the brainstem. Virtually all neurons express TRAAK, and the
highest immunoreactivity was seen in soma, and to a lesser degree in axons and/or
dendrites in most areas in brain and spinal cord. In the retina, the TRAAK
protein is concentrated to the soma of ganglion cells and to the dendrites of all
other neurons. Taken together, these results show a wide distribution of TRAAK, a
mechanosensitive and arachidonic acid-stimulated neuron-specific baseline K+
channel, in brain, spinal cord and retina.
PMID- 10670457
TI - Regional brain variations of cytochrome oxidase activity and motor co-ordination
in staggerer mutant mice.
AB - A mutant mouse with cerebellar cortical atrophy, staggerer, was examined in tests
of motor activity and co-ordination as well as in regional brain metabolism as
assessed by cytochrome oxidase activity. Compared with non-ataxic controls,
staggerer mutants had inferior performances in the open field, the wooden beam,
the wooden edge, and the rotorod tests. An increase in cytochrome oxidase
activity in the deep cerebellar nuclei and in some cerebellar efferent regions,
such as the lateral vestibular nucleus, the parvicellular red nucleus, and the
ventral tegmental area, was found in staggerer mutant mice. Abnormally high
cytochrome oxidase activity in the interpositus and the dentate nuclei was
linearly correlated with poor performance on the wooden beam and on the rotorod.
High cytochrome oxidase activity in the lateral vestibular nucleus was also
associated with poor performance on the wooden beam. Moreover, high cytochrome
oxidase activity in the fastigial nucleus was associated with poor performance on
the wooden beam but with high motor activity in the open field. These results
indicate that a lack of innervation of Purkinje cells to the deep cerebellar
nuclei is in part the cause of motor co-ordination deficits in staggerer mutant
mice.
PMID- 10670458
TI - Separate roles for beta2- and beta3-adrenoceptors in memory consolidation.
AB - Consolidation of a labile memory which would not normally be stored can be
achieved by intracerebral administration of noradrenaline. In a series of
experiments using discriminated, one trial passive avoidance learning with the
day-old chick, the effect of noradrenaline has been shown to be due to actions at
different subtypes of adrenoceptors. The effect of noradrenaline is dose
dependent, with a moderate dose producing memory consolidation. However, higher
doses of noradrenaline (0.3-10 nmol/hemisphere) prevent consolidation, an effect
not seen with isoprenaline suggesting that these doses stimulate alpha
adrenoceptors. The promotion of memory consolidation by noradrenaline or
isoprenaline at low doses was attributable to beta3-adrenoceptors and at medium
doses to beta2-adrenoceptors. At higher doses of noradrenaline, there was alpha1
adrenoceptor-mediated inhibition of memory consolidation. Consolidation can also
be achieved by administration of either beta2- or beta3-adrenoceptor agonists at
specific times after training. Although these two adrenoceptors both promoted
memory consolidation, there was a differential action on the stages of memory
formation. The dose-response curve to the beta3- and the beta2-agonists was
shifted by the appropriate antagonist but not by the antagonist at the other beta
adrenoceptor. Although beta1-adrenoceptors are present in chick brain, they do
not seem to have a role in memory formation. These results explain why
noradrenaline, acting at different adrenoceptors, can have different effects on
memory formation with memory being either consolidated or inhibited depending on
the dose. The findings also demonstrate a role in memory formation for beta3
adrenoceptors found in the brain. Agonists acting specifically at beta2- or beta3
adrenoceptors may be of value in diseases involving cognitive impairment.
PMID- 10670459
TI - Long-term depolarization changes morphological parameters of PC12 cells.
AB - It is well known that neuronal differentiation is strongly dependent on the
intracellular level of free calcium ions ([Ca2+]i). In the present study the
morphological and intracellular free calcium concentration changes were compared
on PC12 pheochromocytoma cells cultured in control conditions and in a medium
with high KCl level. Culturing PC12 cells in a medium with 20-30 mM KCl deprived
of nerve growth factor supported cell proliferation and rapid growth of small
neurite-like processes. However, their lengths did not increase with prolongation
of the time of culturing. During culturing with 40 mM KCl the growth of these
processes became blocked; the cells stopped proliferating and showed signs of
degeneration. Measurements of [Ca2+]i level during the first days of PC12 cells
culturing in a hyperpotassium medium indicate that such changes in this level
could be an important factor in the induction of the observed morphological
alterations; however, other effects induced by membrane depolarization may also
be responsible for them.
PMID- 10670460
TI - Biochemistry of visual pigment regeneration: the Friedenwald lecture.
PMID- 10670461
TI - Self-destructive and self-protective processes in the damaged optic nerve:
implications for glaucoma.
PMID- 10670462
TI - Genes upregulated in the human trabecular meshwork in response to elevated
intraocular pressure.
AB - PURPOSE: To identify genes upregulated in perfused, intact human trabecular
meshwork (TM) in response to elevated intraocular pressure (IOP). METHOD: Two
pairs of anterior segments of normal human eyes from postmortem donors were
placed in culture and perfused 24 hours at constant flow (3 microl/min). After
reaching baseline, the flow of one eye from each pair was raised to obtain an
incremental pressure (deltaP) of 50 mm Hg for 6 hours. The anterior segments were
then quickly frozen in liquid nitrogen, and their TMs were dissected for RNA
extraction. SMART cDNA libraries were generated from control and high-pressure
human TM RNAs and hybridized to sets of identical high-density cDNA gene arrays.
These arrays contained 18,376 human expressed sequence tags (ESTs), corresponding
to both characterized and unknown genes. Differentially expressed genes were
identified by different-intensity hybridization signals and confirmed by semi
quantitative polymerase chain reaction. RESULTS: Eleven genes were found to be
consistently upregulated in the human TM by elevated IOP: interleukin-6,
preprotachykinin-1, secretogranin-II, cathepsin-L, stromelysin-1, thymosin-beta4,
alpha-tubulin, alphaB-crystallin, glyceraldehyde-3-phosphate dehydrogenase,
metallothionein and Cu/Zn superoxide dismutase. The products of these genes are
involved in vascular permeability, secretion, extracellular matrix remodeling,
cytoskeleton reorganization, and reactive oxygen species scavenging. CONCLUSIONS:
Elevated IOP induced specific upregulation of 11 physiologically relevant genes.
On the basis of their known activities, the products of each of these genes might
predict homeostatic mechanisms similar to those involved in the regulation of
blood vessel permeability. We hypothesize that similar mechanisms might be
involved in regulating flow through Schlemm's Canal endothelium.
PMID- 10670463
TI - Advanced glycation end products in diabetic corneas.
AB - PURPOSE: Corneal complications are often associated with diabetes mellitus and
can be vision threatening. Corneas in diabetic patients are exposed to increased
glucose concentration despite cornea's avascular property, and this condition may
contribute to the accumulation of advanced glycation end products (AGEs). The
focus of this study was to examine the role of AGEs in the pathogenesis of
diabetic keratopathy. METHODS: An anti-AGE monoclonal antibody (6D12), which
recognizes a N(epsilon)-carboxymethyl lysine (CML)-protein adduct as an epitope,
was prepared. Immunohistochemical localization of CML was examined in human age
matched diabetic and nondiabetic corneas (8 of each). In vitro, type I collagen-,
type IV collagen-, or laminin-coated 96-well plates were glycated by glucose
phosphate. In some experiments, aminoguanidine was present in the incubation
mixture. The amounts of CML-protein adducts in the extracellular matrix (ECM)
were determined by enzyme-linked immunosorbent assay using 6D12. SV40
immortalized human corneal epithelial cells were seeded onto modified or
unmodified ECM in 96-well plates and allowed to attach for 3 hours. Attached
cells were fixed, and the areas of attached cells in each condition were
measured. Attached cells without fixation were removed, and cell number was
counted. RESULTS: In all of the 8 diabetic corneas, CML immunoreactivity was
observed in the epithelial basement membrane, whereas CML immunoreactivity was
not found in the corresponding area in 7 of 8 nondiabetic corneas. In vitro,
nonenzymatic glycation of laminin on the culture dish attenuated adhesion and
spreading of corneal epithelial cells. The presence of amninoguanidine in the
incubation mixture during glycation inhibited CML formation and promoted the
adhesion and spreading of corneal epithelial cells in a dose-dependent manner.
CONCLUSIONS: The accumulation of AGEs on the basement membrane, particularly on
laminin, may play a causative role in the corneal epithelial disorders of
diabetic patients.
PMID- 10670464
TI - Corneal stromal changes induced by myopic LASIK.
AB - PURPOSE. Despite the rapidly growing popularity of laser in situ keratomileusis
(LASIK) in correction of myopia, the tissue responses have not been thoroughly
investigated. The aim was to characterize morphologic changes induced by myopic
LASIK in human corneal stroma. METHODS: Sixty-two myopic eyes were examined once
at 3 days to 2 years after LASIK using in vivo confocal microscopy for
measurement of flap thickness, keratocyte response zones, and objective grading
of haze. RESULTS: Confocal microscopy revealed corneal flap interface particles
in 100% of eyes and microfolds at the Bowman's layer in 96.8%. The flaps were
thinner (112 +/- 25 microm) than intended (160 microm). The keratocyte activation
in the stromal bed was greatest on the third postoperative day. Patients with
increased interface reflectivity due to abnormal extracellular matrix or
activated keratocytes at > or = 1 month (n = 9) had significantly thinner flaps
than patients with normal interface reflectivity (n = 18; 114 +/- 12 versus 132
+/- 22 microm, P = 0.027). After 6 months the mean density of the most anterior
layer of flap keratocytes was decreased. CONCLUSIONS: Keratocyte activation
induced by LASIK was of short duration compared with that reported after
photorefractive keratectomy. The flaps were thinner than expected, and microfolds
and interface particles were common complications. The new findings such as
increased interface reflectivity associated with thin flaps and the apparent loss
of keratocytes in the most anterior flap 6 months to 2 years after surgery may
have important clinical relevance.
PMID- 10670465
TI - Experimental corneal endotheliitis in rabbit.
AB - PURPOSE: Corneal endotheliitis may cause permanent visual loss due to endothelial
decompensation. The pathogenesis underlying this distinct clinical entity is not
known. In the current study, a rabbit herpetic corneal endotheliitis model was
made of induced anterior chamber-associated immune deviation (ACAID). METHODS:
One group of rabbits received left-eye intracameral inoculation of UV-inactivated
herpes simplex virus (HSV)-1 (strain McKrae). The second group received cell
medium in the same manner as the first group. The third group subcutaneously
received the same inoculum as the first group. Seven days later, all right eyes
were intracamerally infected with 2.5 x 10(4) plaque-forming units of infectious
HSV-1. Eyes were evaluated by slit lamp examination. Two weeks after infection,
rabbits were killed, and right eyes were examined by immunohistochemical staining
and electron microscopy. Aqueous humor was detected for HSV-1 DNA and antibody.
RESULTS: Nonspecific inflammation occurred in the anterior segments of the eyes
from the second and third groups. In contrast, at 14 days after infection, the
first group of rabbits showed a specific pattern of inflammation that greatly
resembled clinical features of corneal endotheliitis. Viral antigen was detected
only in the endothelial layer. Electron microscopy revealed enlarged
intercellular gaps and infiltration of inflammatory cells that are characteristic
of endothelial defects. HSV-1 DNA was detected at a significantly higher number
in the aqueous humor aspirates from endotheliitis rabbits. In addition, ACAID was
shown to be induced in the rabbits with corneal endotheliitis. CONCLUSIONS: HSV-1
infection can induce corneal endotheliitis and ACAID may play the pivotal role in
this entity.
PMID- 10670466
TI - Cholinergic-induced Ca2+ elevation in rat lacrimal gland acini is negatively
modulated by PKCdelta and PKCepsilon.
AB - PURPOSE: To investigate the role of protein kinase C (PKC) in cholinergic agonist
induced Ca2+ elevation in lacrimal gland acini. METHODS: Lacrimal gland acini
were prepared by collagenase digestion, and changes in intracellular Ca2+
([Ca2+]i) were measured using fura-2 as a fluorescent probe. RESULTS:
Preactivation of PKC by phorbol 12-myristate 13-acetate (PMA), or inhibition of
protein phosphatase type 1/2A (PP1/2A) by calyculin A, decreased both the [Ca2+]i
transient and the plateau of [Ca2+]i induced by increasing concentrations of
carbachol, a cholinergic agonist. Staurosporine, an inhibitor of PKC, completely
reversed the effect of PMA. Inhibition of the Ca(2+)-independent PKC isoforms
PKCdelta and -epsilon, but not the Ca(2+)-dependent isoform PKCalpha
substantially reversed the inhibitory effect of PMA on cholinergic agonist
induced Ca2+ elevation. The inhibitory effect of PMA was obtained only in the
presence of extracellular Ca2+, suggesting that PKC inhibits the influx of Ca2+.
PMA completely inhibited the cholinergic agonist-induced plateau of [Ca2+]i. PMA
and calyculin A decreased both the [Ca2+]i transient and the plateau of [Ca2+]i
induced by thapsigargin, further supporting the idea that PKC modulates the entry
of Ca2+. CONCLUSIONS: In the lacrimal gland, agonist-induced changes in [Ca2+]i
are negatively regulated by PKC-dependent phosphorylation of a target protein(s)
that is sensitive to PP1/2A.
PMID- 10670467
TI - Effect of myopic LASIK on corneal sensitivity and morphology of subbasal nerves.
AB - PURPOSE: To investigate whether the morphology of the subbasal nerves corresponds
to corneal sensitivity after laser in situ keratomileusis (LASIK). METHODS: In a
case series study, 59 patients were examined at 2 to 4 hours, 3 days, 1 to 2
weeks, 1 to 2 months, 3 months, or 6 or more months after undergoing LASIK for
myopia, by using a Cochet-Bonnet esthesiometer and an in vivo confocal
microscope, and were compared with control subjects. Corneal sensitivity and
confocal images of subbasal nerves were obtained centrally and 2 mm nasally and
temporally. Subbasal nerve fiber bundles (NFBs) were grouped as follows: corneas
with no nerve images; corneas with short (<200 microm), unconnected NFBs; corneas
with long (> or =200 microm) NFBs without interconnections; and corneas with long
NFBs with interconnections. RESULTS: Corneal sensitivity was at its lowest at 1
to 2 weeks after LASIK. Sensitivity of the hinge area was higher than temporal or
central areas at every time point. At 6 or more months the sensitivity values
were comparable with the values observed in control subjects. The central area
showed mainly short, unconnected subbasal NFBs, even at 6 months. In general, the
temporal area presented with long NFBs from 3 months onward, whereas the nasal
area showed long NFBs at every time point. CONCLUSIONS: The results suggest that
the corneal areas with no nerve images or short, unconnected NFBs are associated
with lower sensitivities than corneal areas with long NFBs with or without
interconnections. In vivo confocal microscopy reveals LASIK-induced alterations
of subbasal nerve morphology and thus enables a direct comparison of corneal
sensory innervation and sensitivity.
PMID- 10670468
TI - Membrane-associated mucins in normal human conjunctiva.
AB - PURPOSE: To examine the presence of specific membrane-associated mucins in normal
human conjunctiva. METHODS: Glycoconjugates were extracted from membranes with
two detergents: octylglucoside and Triton X114. Mucins were separated by cesium
chloride density gradient centrifugation. Size was assessed by gel filtration on
Sepharose CL2B and charge by ion-exchange chromatography on MonoQ. Cross reaction
with antibodies against mucin gene products was assessed in blots of
electrophoresis gels. RESULTS: Extraction of total tissue membranes yielded
material with a buoyant density typical of mucins. Gel filtration showed material
reacting with antimucin antibodies in a range of molecular sizes. Agarose
electrophoresis confirmed the presence of MUC1 and MUC4 and the absence of MUC2
or MUC5AC. Isolation of membrane mucins by sequential, exhaustive extraction with
octylglucoside followed by Triton X114 suggested the existence of mucins in
different membrane environments. Reagents to carbohydrate epitopes revealed high
mobility material, comigrating with MUC1 and MUC4. Low mobility membrane-bound
mucins did not cross-react with any antibodies to mucin genes known to be
expressed in human conjunctiva. CONCLUSIONS: Membrane-associated mucins are
distinct from secreted mucins in normal human conjunctiva. MUC1 and MUC4 mature
products decorate the membranes of conjunctival epithelial cells. Their
segregation between octyl glucoside and the detergent and aqueous phases of
Triton X114 suggests a variety of membrane anchoring modes.
PMID- 10670470
TI - Motion VEPs, stereopsis, and bifoveal fusion in children with strabismus.
AB - PURPOSE: The link between nasal-temporal motion asymmetries and anomalous
binocular sensory function in infantile esotropia (ET) has led to the idea that
visual evoked potential responses to horizontal motion (mVE) is an alternative
measure of sensory binocularity to stereopsis. A second hypothesis is that the
mVEP response is a marker for bifoveal fusion. The purpose of this study was to
directly evaluate these two hypotheses by examining the correspondence between
the mVEP response and both stereoacuity and bifoveal fusion in a cohort of
strabismic patients with variable binocular sensory function. METHODS: Motion
VEPs, random dot stereopsis, and bifoveal fusion were measured in 94 children: 20
with infantile ET, 16 with infantile accommodative ET, 22 with late-onset
accommodative ET, 10 with intermittent infantile strabismus, and 26 normal
control participants. RESULTS: Patients with infantile ET and infantile
accommodative ET had high concordance between mVEP responses and stereoacuity and
mVEP responses and bifoveal fusion. Asymmetric mVEP responses were highly
concordant with both no measurable stereopsis and an absence of fusional
vergence. Patients with late-onset accommodative ET and intermittent infantile
strabismus revealed discordance between the mVEP response and stereoacuity and
high concordance between the mVEP response and bifoveal fusion. Asymmetric mVEP
responses were highly concordant with the absence of bifoveal fusion and the
minimum-size prism to elicit fusional vergence. CONCLUSIONS: The qualitative and
quantitative relationship between the mVEP response and fusional vergence
suggests that the mVEP response is an objective measure of bifoveal fusion. The
availability of such a test will facilitate studies of normal development of
bifoveal fusion and development of monofixation syndrome in strabismus.
PMID- 10670469
TI - Overexpression of MMP-1 and MMP-3 by cultured conjunctivochalasis fibroblasts.
AB - PURPOSE: To determine whether conjunctivochalasis, denoting redundant, loose,
nonedematous inferior bulbar conjunctiva, is associated with increased expression
and activity of matrix metalloproteinases (MMPS) over their tissue inhibitors
(TIMPs). METHODS: Expression of transcripts and proteins of MMPs, TIMPs, and
urokinase plasminogen activator (uPA) by cultured normal human conjunctival and
conjunctivochalasis fibroblasts was determined by Northern hybridization, enzyme
linked immunosorbent assay (ELISA), and Western blot analysis, respectively.
Gelatin and casein zymography and quantitative collagenase activity assay were
performed in the serum-free conditioned media. RESULTS: Compared with normal
conjunctival fibroblasts from six subjects, conjunctivochalasis fibroblasts from
eight patients showed markedly increased transcript expression of MMP-1 (5- to 32
fold) and MMP-3 (4 to 30-fold), whereas that of MMP-2, TIMP-1, TIMP-2, and uPA
was similar between the two groups. Protein levels were increased in the serum
free conditioned media of conjunctivochalasis fibroblasts for MMP-1 (3.5- to 7.6
fold) and MMP-3 (2.3- to 13-fold), determined by ELISA and Western blot analysis.
There was increased caseinolytic activity of MMP-3 and collagenolytic activity of
MMP-1 (2.2-fold) by conjunctivochalasis fibroblasts, whereas no difference was
noted between these two types of fibroblasts in the protein and gelatinolytic
activity of MMP-2 or expression of TIMP-1 and TIMP-2 proteins, although that of
TIMP-1 transcript was slightly higher in some conjunctivochalasis fibroblasts. No
expression of MMP-9 was detected. CONCLUSIONS: Overexpression of MMP-1 and MMP-3
mRNA by conjunctivochalasis fibroblasts is correlated with their increased
protein levels and proteolytic activities. Collectively, these data help explain
how conjunctivochalasis manifests excessive degradation of the conjunctival
matrix and Tenon's capsule.
PMID- 10670471
TI - Response variability in the visual field: comparison of optic neuritis, glaucoma,
ocular hypertension, and normal eyes.
AB - PURPOSE: To compare the relationship between sensitivity and response variability
in the visual field of normal eyes and eyes with optic neuritis (ON), glaucoma
(POAG), and ocular hypertension (OHT). METHODS: Frequency-of-seeing (FOS) data
were collected from four visual field locations in one eye of 71 subjects (12 ON,
25 POAG, 11 OHT, and 23 normal), using a constant stimulus method on an Henson
4000 perimeter (Tinsley Instruments, Croydon, UK). At each location, at least 20
stimuli (subtending 0.5 degrees) were presented for 200 ms at six or more
intensities above and below the estimated threshold. The mean and SD of the
probit fitted cumulative Normal function were used to estimate sensitivity and
response variability. Cluster regression analysis was carried out to determine
whether there were differences in the sensitivity-log (variability) relationship
between the four groups. RESULTS: Variability was found to increase with
decreased sensitivity for all four groups. The combined data from the four groups
was well represented (R2 = 0.57) by the function log(e)(SD) = A.sensitivity (dB)
+ B, where the constants A and B were -0.081 (SE, +/-0.005) and 3.27 (SE, +/
0.15), respectively. Including other statistically significant covariates (false
negative errors, P = 0.004) and factors (diagnosis, P = 0.005) into the model
increased the proportion of explained variance to 62% (R2 = 0.62). Stimulus
eccentricity (P = 0.34), patient age (P = 0.33), fixation loss rate (P = 0.10),
and false-positive rate (P = 0.66) did not reach statistical significance as
additional predictors of response variability. CONCLUSIONS: The relationship
between response variability and sensitivity is similar for ON, POAG, OHT, and
normal eyes. These results provide supporting evidence for the hypothesis that
response variability is dependent on functional ganglion cell density.
PMID- 10670472
TI - Mediation of laser trabeculoplasty-induced matrix metalloproteinase expression by
IL-1beta and TNFalpha.
AB - PURPOSE: Laser trabeculoplasty of the anterior uveal region of the trabecular
meshwork induces sustained matrix metafloproteinase expression within the
juxtacanalicular region of the meshwork. Studies were conducted to test the
hypothesis that a factor mediates this response and to identify the factor.
METHODS: Human anterior segment organ cultures were subjected to laser treatment
using standard clinical parameters and were returned to culture for 8 hours. The
resultant 8-hour-conditioned culture medium was then tested for factor activity
by evaluating its ability to produce two typical trabecular responses to laser
treatment, that is, to induce stromelysin expression or to trigger cell division,
when applied to fresh organ cultures or to cell cultures. Confocal
immunohistochemistry of the laser-treated organ cultures and western immunoblot
analysis of the conditioned medium were used to evaluate changes in potential
candidates for the factor activity. The ability of the interleukin (IL)-1
receptor antagonist (IL-1ra)- and of tumor necrosis factor alpha (TNFalpha)-
blocking antibodies to eliminate the stromelysin induction was evaluated.
RESULTS: Medium conditioned for 8 hours induced typical trabecular cell division
in anterior segment organ cultures. Medium conditioned for 8 hours, but not for
30 minutes, induced typical increases in stromelysin expression in these organ
cultures and in cell cultures. After 8 hours, both trabecular cells in laser
treated organ cultures and in the conditioned medium contained elevated levels of
IL-1beta and TNFalpha. The laser-treated organ cultures contained elevated levels
of IL-1alpha, but it was not secreted into the medium. The ability of conditioned
media to induce stromelysin expression was partially blocked by either the IL-1ra
or the TNFalpha-blocking antibody. CONCLUSIONS: Laser trabeculoplasty induces
the expression and secretion of both IL-1beta and TNFalpha within the first 8
hours after treatment. These cytokines then mediate increased trabecular
stromelysin expression. Putatively, this initiates remodeling of the
juxtacanalicular extracellular matrix, a likely site for the aqueous outflow
resistance, and thus restores normal outflow facility.
PMID- 10670473
TI - Chronology of optic nerve head and retinal responses to elevated intraocular
pressure.
AB - PURPOSE: To determine the chronology of optic nerve head and retinal responses to
elevated intraocular pressure (IOP). METHODS: After 1 to 39 days of unilaterally
elevated IOP, experimental and fellow rat eyes were examined for morphology and
immunohistochemical labeling alterations and for ganglion cell DNA fragmentation.
RESULTS: Mean IOP for the experimental eyes was 36 +/- 8 mm Hg, an approximately
15-mm Hg elevation above normal values. By 7 days of pressure elevation above 40
mm Hg, endogenous immunostaining for brain-derived neurotrophic factor and
neurotrophin 4/5 was absent from the nerve head and superior retina, whereas
normal labeling was present in the inferior retina and distal optic nerve of
these same eyes. These changes were preceded by a loss of gap junctional
connexin43 labeling and astrocytic proliferation in the nerve head and by
increased retinal ganglion cell layer apoptosis in the retina. Nerve head
depletion of neurotrophins coincided with evidence of axonal degeneration, loss
of astrocytic glial fibrillary acidic protein staining, and spread of collagen VI
vascular immunolabeling. After longer durations at these same pressures,
neurotrophin labeling returned to nerve head glia and scattered retinal ganglion
cells. CONCLUSIONS: Optic nerve head and retinal responses, including the
depletion of endogenous neurotrophins, are readily identified in the rat eye
after experimental IOP elevation. However, the apparent chronology of these
responses suggests that the withdrawal of neurotrophic support was not the only
determinant of retinal ganglion cell apoptosis and axonal degeneration in
response to pressure.
PMID- 10670474
TI - Epithelium-deficient corneal allografts display immune privilege beneath the
kidney capsule.
AB - PURPOSE: To determine whether corneal tissue as an allograft displays immune
privilege in a nonprivileged site and, if so, whether CD95 ligand expression
contributes to the privileged status. METHODS: Syngenic and allogeneic corneal
tissues deprived of epithelium were transplanted beneath the kidney capsule of
normal mice. Syngeneic BALB/c, allogeneic C57BL/6, and allogeneic B6Smn.C3H-gld
(CD95 ligand-deficient) mice were used as donors for BALB/c recipients, and
syngeneic C3H/HeJ-gld (CD95 ligand-deficient) mice were used for normal C3H/HeJ
recipients. Allogeneic conjunctival segments served as positive grafting
controls. Graft fate was assessed by visual inspection at 4, 7, 14, and 21 days
and was confirmed by histologic study. Viability of graft endothelium was
assessed by immunocytochemical analysis. RESULTS: Syngeneic corneas and C57BL/6
corneas survived almost indefinitely beneath the kidney capsule. Both the stroma
and the endothelial layers remained healthy and intact. Allogeneic conjunctiva
evoked a strong inflammatory response attended by neovascularization. Similarly,
B6-gld corneas deficient in CD95 ligand expression showed acute destruction
beneath the kidney capsule. Circumstantial evidence implicates alloimmune
rejection as the mechanism. CONCLUSIONS: Epithelium-deprived corneas from normal
mice possess inherent immune privilege that protects them from alloimmune
rejection even at nonprivileged sites. Constitutive expression of CD95 ligand
contributes to the privileged status. It is inferred that the extraordinary
success of orthotopic corneal allografts owes as much to the qualities of the
graft as an immune-privileged tissue as to the qualities of the eye as an immune
privileged site.
PMID- 10670475
TI - Bystander activation of CD4+ T cells accounts for herpetic ocular lesions.
AB - PURPOSE: Stromal keratitis is an immunopathologic consequence of herpes simplex
virus (HSV) infection of the cornea. The lesion is immunopathologic, but the
identities of molecules that drive the reaction remain unresolved. To exclude
viral antigen recognition as a necessary step in the disease process, ocular HSV
infection was followed in Tg-RAG mice (OVA-TCR transgenic mice crossed to RAG2
deficient mice) whose limited T-cell repertoire did not include immune
responsiveness to HSV. METHODS: Mice with T-cell specificity to OVA peptide (Tg
RAG mice) as well as control DO11.10 and BALB/c mice were infected with HSV on
the scarified cornea and subjected to clinical, histologic, and immunologic
analysis. To evaluate involvement of OVA-specific CD4+ T cells in lesion
development in Tg-RAG mice, monoclonal antibody to CD4+ T cells was used for in
vivo CD4+ T-cell depletion. RESULTS: Tg-RAG mice were capable of eliciting ocular
lesions in the absence of detectable reactivity to viral antigens. Lesion
manifestation in Tg-RAG mice was CD4+ T-cell dependent and the cellular
infiltrates and their inflammatory products in the HSV-infected cornea were
comparable to similarly infected BALB/c and DO11.10 mice. CONCLUSIONS: The
authors conclude that mechanisms other than viral antigen recognition, and hence
molecular mimicry, are at play and are sufficient to cause HSV-induced stromal
keratitis. The data imply a significant role for non-virus-specific CD4+ T cells
that could become activated by an inflammatory milieu consisting of enhanced
accessory molecules and proinflammatory cytokines in the cornea.
PMID- 10670476
TI - Efficacy of topical cidofovir on multiple adenoviral serotypes in the New Zealand
rabbit ocular model.
AB - PURPOSE: The goal of the present study was to determine the efficacy of topical
0.5% cidofovir twice daily for 7 days on the replication of multiple adenovirus
(Ad) serotypes of subgroup C (Ad1, Ad5, Ad6) in the New Zealand rabbit ocular
model. METHODS: In duplicate experiments for each serotype, a total of 20 rabbits
(Ad5) or 16 rabbits each (Ad1 and Ad6) were inoculated topically in both eyes,
with 1.5 X 10(6) pfu/eye of the appropriate virus. Twenty-four hours later, the
rabbits in each serotype group were randomly divided into two topical treatment
groups: I, 0.5% cidofovir; II, control vehicle. Treatment was twice daily for 7
days. All eyes were cultured for virus on days 0, 1, 3, 4, 5, 7, 9, 11, and 14.
RESULTS: Compared to the control, treatment with 0.5% cidofovir reduced the
following: mean Ad titer (days 1 to 7) for Ad1 (6.3 +/- 20 x 10(1) versus 2.5 +/-
3.9 X 102 pfu/ml; P < 0.0003), Ad5 (3.4 +/-5.8 x 102 versus 1.6 +/- 2.0 x 10(3)
pfu/ml; P < 0.000001), and Ad6 (1.2 +/- 5.1 x 10(2) versus 5.5 +/-14 x 10(2)
pfu/ml; P = 0.015); reduced Ad-positive eyes/total for Adl [45/128 (35%) versus
84/128 (66%); P = 0.000002], Ad5 [84/160 (53%) versus 131/152 (86%); P <
0.000001], and Ad6 [36/128 (28%) versus 82/128 (64%); P < 0.000001]: and reduced
the duration of Ad shedding forAdl (4.9 +/-1.9 versus 9.3 +/- 3.3 days; P <
0.00007), Ad5 (6.4 +/- 2.8 versus 11.5 +/- 2.3 days; P < 0.0001), and Ad6 (4.4 +/
2.1 versus 8.4 +/- 2.5 days; P < 0.00004). CONCLUSIONS: Topical 0.5% cidofovir
twice daily for 7 days demonstrated significant antiviral activity against
multiple adenoviral serotypes (Ad1, Ad5, and Ad6) in the New Zealand rabbit
ocular model. These in vivo data expand in vitro studies indicating the efficacy
of cidofovir against different adenovirus serotypes and support its use in
clinical trials.
PMID- 10670477
TI - Truncated forms of Pax-6 disrupt lens morphology in transgenic mice.
AB - PURPOSE: Extensive literature shows that Pax-6 is critical for lens development
and that Paxb mutations can result in aniridia in humans. In addition, it has
been reported that truncated Pax-6 molecules can act as dominant-negative
repressors of wild-type Pax-6 activity in cultured cells. This study was designed
to determine whether Pax-6 molecules without either the activation domain (AD) or
the homeodomain (HD) and the AD can function as dominant-negative repressors in
vivo and alter the phenotype of the lens. METHODS: Transgenic mice were created
harboring the alphaA-crystallin promoter linked to a cDNA encoding either a
truncated Pax-6 without the C terminus (paired domain [PD] + homeodomain) or Pax
6 consisting of only the PD. The phenotype of the resultant animals was
investigated by light and electron microscopy as well as atomic absorption
spectroscopy. RESULTS: Two lines of PD + HD mice and three lines of PD mice were
generated, all of which exhibit posterior nuclear and/or cortical cataracts of
variable severity. The lenses from mice transgenic for either Pax-6 truncation
are smaller and more hydrated than normal. Morphologically, the mice expressing
the PD + HD of Pax-6 have swollen lens fibers with attenuated ball-and-socket
junctions. In contrast, the lenses from mice overexpressing the PD of Pax-6 have
posterior nuclear cataracts composed of cell debris, whereas the remaining fiber
cells appear generally normal. CONCLUSIONS: The presence of truncated Pax-6
protein in the lens is sufficient to induce cataract in a wild-type genetic
background. The simplest explanation for this phenomenon is a dominant-negative
effect; however, a number of other possible mechanisms are presented.
PMID- 10670478
TI - Noncontact specular microscopy of human lens epithelium.
AB - PURPOSE: To obtain in vivo specular images of human lens epithelial cells (LECs)
from persons with or without age-related cataract (ARC); to identify features
that describe individual aspects of these complex images; to develop feature
scales to quantify the severity of each feature; and to study the association of
these features with LEC count, age, Lens Opacity Classification System III (LOCS
III) classifications and microscopic features of lens epithelium in ARC. METHODS:
One hundred fifty-two individuals underwent ophthalmic examinations and LOCS III
cataract classifications. Specular images of lenses were captured using a
modified noncontact corneal specular microscope (SML-2; Konan, Hyogo, Japan).
Enhanced images were graded in a masked fashion, and the presence or absence and
severity of each of four features in the specular image ("columnar organization,"
"linear furrows," "puffy clouds," and "black holes") was graded on a four-step
scale. The generalized linear model with intraclass correlation was used to
ascertain the statistical significance of associations between age, sex, LOCS III
grade, cell count, and feature grade. Capsulorrhexis specimens from 29 patients
were studied with correlative light and electron microscopy. RESULTS: LEC density
declined with age and was inversely correlated with the scalar grade for puffy
clouds and for the size and number of black holes. The scalar grade for columnar
organization was inversely associated with the severity of posterior subcapsular
and nuclear cataracts, which was the only feature associated with the LOCS III
grade of ARC. No statistically significant associations were found between
average cell count and LOCS III grade. CONCLUSIONS: With the use of the corneal
specular microscope excellent in vivo specular images of the LECs were obtained,
the features in these images that correlated well with microscopic findings were
classified, and cell density in vivo was estimated.
PMID- 10670479
TI - Use of a lipophilic cation to monitor electrical membrane potential in the intact
rat lens.
AB - PURPOSE: Tetraphenylphosphonium (TPP+) is a permeant lipophilic cation that
accumulates in cultured cells and tissues as a function of the electrical
membrane potential across the plasma membrane. This study was undertaken to
determine whether TPP+ can be used for assessing membrane potential in intact
lenses in organ culture. METHODS: Rat lenses were cultured in media containing 10
microM TPP+ and a tracer level of 3H-TPP+ for various times. 3H-TPP+ levels in
whole lenses or dissected portions of lenses were determined by liquid
scintillation counting. Ionophores, transport inhibitors, and neurotransmitters
were also added to investigate their effects on TPP+ uptake. RESULTS. Incubation
of lenses in low-K+ balanced salt solution and TC-199 medium, containing
physiological concentrations of Na+ and K+, led to a biphasic accumulation of
TPP+ in the lens that approached equilibrium by 12 to 16 hours of culture. The
TPP+ equilibrated within 1 hour in the epithelium but penetrated more slowly into
the fiber mass. The steady state level of TPP+ accumulation in the lens was
depressed by 90% when the lenses were cultured in a medium containing high K+.
The calculated membrane potential for the normal rat lens in TC-199 was -75 +/- 3
mV. Monensin (1 microM) and nigericin (1 microM), Na+H+ and K+H+ exchangers
respectively, as well as the protonophore carbonylcyanide-m-chlorophenylhydrazone
(CCCP, 10 microM) and the calcium ionophore A23187 (10 microM), abolished TPP+
accumulation and caused cloudiness of the lenses. The neurotransmitter
acetylcholine at 50 microM decreased TPP+ accumulation in the lens, but this
effect could be prevented by simultaneous application of 1 mM atropine.
CONCLUSIONS: TPP+ accumulation can be used as an indicator of changes in membrane
potential in intact lenses, but because of the long time required to reach steady
state, its utility is limited. The slow accumulation of TPP+ and its slow efflux
from the lens under conditions known to depolarize membranes are consistent with
a diffusion barrier in the deep cortex and nucleus of the lens.
PMID- 10670481
TI - Autofluorescence distribution associated with drusen in age-related macular
degeneration.
AB - PURPOSE: To determine whether drusen in patients with age-related maculopathy and
macular degeneration (ARM/AMD) are associated with focal changes in retinal
pigment epithelium (RPE) lipofuscin fluorescence. METHOD: A new autofluorescence
imaging device was used to study lipofuscin distribution associated with
individual drusen in 20 patients with ARM/AMD. Paired monochromatic and
autofluorescence fundus images were used for detailed analysis of the topography
of autofluorescence at specific sites containing drusen. In four eyes, image
analysis was used to compare the spatial distribution of the autofluorescence
with the location of drusen and to quantify the autofluorescence distribution
over individual drusen (54 drusen). REsuLTs. A specific pattern of
autofluorescence was frequently found to be spatially associated with hard drusen
and soft drusen between 60 and 175 microm in size. The pattern is characterized
by a central area of decreased autofluorescence surrounded, in most cases, by an
annulus of increased autofluorescence. The location of this pattern was highly
correlated with the position of individual distinct drusen. The central low
autofluorescence focus was on average 16% below the surrounding background, and
the annulus, when present, was on average 6% more fluorescent than the
background. Soft drusen larger than 175 microm and confluent soft drusen show
either multifocal areas of low autofluorescence or a more heterogeneous
distribution. CONCLUSIoNs. Autofluorescence imaging permits measurement of RPE
lipofuscin at specific sites. RPE overlying drusen have altered autofluorescence,
suggesting changes in RPE health.
PMID- 10670480
TI - Basolateral Na(+)-K(+)-2Cl(-) cotransport in cultured and fresh bovine corneal
endothelium.
AB - PURPOSE: To examine whether Na(+)-K(+)-2Cl(-) cotransport has the potential to
contribute to corneal endothelial ion and fluid transport in cultured and fresh
bovine corneal endothelial cells. METHODS: Cl- and Na+ sensitive fluorescent dyes
were used to measure furosemide-dependent ion fluxes in cultured and fresh
endothelial cells. Immunoblot analysis and immunofluorescence were used to
determine expression and location of the Na(+)-K(+)-2Cl(-)cotransporter (NKCC1).
RESULTS: Application of furosemide (50-100 microM) reduced Cl- and Na+ influx in
approximately 50% of trials using cultured cells and only 10% of trials with
fresh cells; however, in all cases pretreatment with furosemide slowed Cl- efflux
when cells were bathed in Cl(-)-free Ringer's. Double-sided perfusion of cultured
cells indicated that furosemide-sensitive Cl- fluxes were located on the
basolateral side. Immunoblot analysis revealed 174-kDa bands in both fresh and
cultured cells, but the bands were denser in fresh endothelial cells.
Immunofluorescence showed distinct lateral membrane staining in addition to
significant amounts of perinuclear staining. CONCLUSIONS: The Na(+)-K(+)-2Cl(-)
cotransporter is present in both fresh and cultured bovine corneal endothelium,
and the expression is apparently higher in the fresh cells. The cotransporter is
present on the lateral membrane consistent with a role in loading endothelial
cells with Cl-, thereby possibly contributing to a transendothelial Cl- flux.
However, in the resting cell, net flux through the transporter is often not
apparent.
PMID- 10670482
TI - Erbium: YAG laser ablation of retinal tissue under perfluorodecaline:
determination of laser-tissue interaction in pig eyes.
AB - PURPOSE: To evaluate the effect of Er;YAG laser on pig retina using a
perfluorodecaline/retina interphase with the goal of precisely determining the
extent of retinal tissue ablation. METHODS: Free running (tau = 250 microsec)
Er:YAG laser pulses were transmitted through a zirconium fluoride (ZrF4) fiber
guarded by quartz rod (d = 1000 microm). Laser pulses were applied to the retinal
surface of enucleated pig eyes. Eyes were mounted in a specially designed
rotating sample holder. The fiber probe was elevated 1.0 +/- 0.3 mm above the
retinal surface with perfluorodecaline serving as transmitting medium. The laser
energy was applied in a circular pattern with a radius of 3.0 mm. Radiant
exposures were set to 1, 3, 5, and 10 J/cm2. RESULTS: Tissue ablation linearly
increased with radiant exposure from 3.2 +/- 3.7 microm at 1 J/cm2 up to 40.9 +/-
12.9 microm at 10 J/cm2. Thermal tissue changes extended 70 +/- 10 microm
vertically into the retina and 25 +/- 5 microm horizontally. Distortion of outer
photoreceptor segments was noticed when the retina was exposed to radiant
exposures of 3 J/cm2 or higher. CONCLUSIONS: The Er:YAG laser in combination with
perfluorodecaline produced precise ablation of the pig retina, which suggests the
feasibility of this technique for safe ablation of epiretinal membranes.
PMID- 10670483
TI - Multifocal electroretinogram in occult macular dystrophy.
AB - PURPOSE: Occult macular dystrophy (OMD) is an unusual macular dystrophy
presenting with an essentially normal fundus and fluorescein angiography but with
progressive central visual loss. The authors studied the function of local
retinal areas in the posterior pole of patients with OMD using multifocal
electroretinograms (ERGs). METHODS: Multifocal ERGs were recorded using the
Visual Evoked Response Imaging System with 61 hexagonal elements within a visual
field of 30 degrees radius from 8 OMD patients and 20 age-matched, normal
subjects. The amplitudes and implicit times of the patients and normal control
subjects were compared at the various retinal eccentricities. RESULTs. The
amplitudes of the multifocal ERGs in the OMD patients were markedly reduced in
the central 7 degrees of the fovea. The difference of the ERG amplitudes between
OMD and normal subjects became smaller toward the peripheral retina. Most OMD
patients had slight but significantly delayed implicit times across the whole
testing field, and the differences between the OMD and the normal subjects did
not change with retinal eccentricity. CONCLUSIONS: Our results for multifocal ERG
amplitudes support the idea that OMD patients have localized retinal dysfunction
distal to the ganglion cells in the central retina. The delayed implicit times
across the whole test field suggest that the retinal dysfunction has a broader
boundary than expected by ERG amplitudes and psychophysical perimetric results.
PMID- 10670484
TI - Schwann cell grafting into the retina of the dystrophic RCS rat limits functional
deterioration. Royal College of Surgeons.
AB - PURPOSE: To examine whether congenic Schwann cells grafted into the subretinal
space of dystrophic Royal College of Surgeons (RCS) rats can prevent
photoreceptor loss and maintain visual function. METHODS: Purified neonatal
Schwann cells derived from congenic rats were grafted into the subretinal space
of 3- to 4-week-old dystrophic RCS rats. Graft placement was confirmed using
Schwann cells labeled in vitro with the fluorescent dye Hoechst 33342 or in
grafted eyes processed for electron microscopy (48-hour to 1-month survival). At
longer intervals, up to 9 months after surgery, animals were examined for
photoreceptor survival; preservation of a visual reflex, head-tracking to moving
stripes; and preservation of visual receptive fields associated with the region
of graft placement. RESULTS: One week after the graft was performed, Schwann
cells had integrated into the subretinal space with little evidence of a reactive
response. When screened for head-tracking to moving stripes, Schwann cell-grafted
animals performed better than sham-treated or control dystrophic animals.
Threshold sensitivity measurements and visual field assessment made by recording
from the superior colliculus also showed a significant level of preserved
function compared with control animals. Functional rescue was correlated with
photoreceptor survival and could be observed for at least 9 months after
grafting. CONCLUSIONS: Schwann cells injected into the subretinal space limit
functional deterioration and prolong photoreceptor survival. It is suggested that
they act by local release of growth factors that either support photoreceptors
directly and/or stimulate phagocytosis in RPE cells.
PMID- 10670485
TI - Tractional force generation by porcine Muller cells: paracrine stimulation by
retinal pigment epithelium.
AB - PURPOSE: To examine the ability of retinal pigment epithelial (RPE) cells to
modulate Muller cell extracellular matrix contraction through secreted promoters.
METHODS: Freshly isolated RPE cells were maintained in continuous culture until
the morphologic and immunocytochemical changes associated with myofibroblastic
dedifferentiation were complete. Secretory products collected from these cells
during extended incubations in serum-free medium and at different stages of
dedifferentiation were examined for the ability to promote extracellular matrix
contraction by Muller cells. The contributions of specific growth factors to RPE
secreted activity were examined with growth factor-neutralizing antibodies.
RESULTS: Secretory products from RPE cells throughout dedifferentiation contained
biologically active quantities of Muller cell contraction promoters. Secretory
activity increased during extended incubation in serum-free medium and during
myofibroblastic dedifferentiation. Growth factor-specific neutralizing antibodies
enabled the determination that insulin-like growth factor- and platelet-derived
growth factor-related proteins were the secreted species to which Muller cells
responded. Finally, gene expression of insulin-like growth factor 1 and platelet
derived growth factor A chain by porcine RPE cells was confirmed using reverse
transcription-polymerase chain reaction. CONCLUSIONS. RPE cells are a viable
source of biologically active quantities of two growth factors that stimulate
extracellular matrix contraction by Muller cells. This secretory profile persists
for extended periods in an otherwise serum-free environment and is enhanced
during myofibroblastic dedifferentiation.
PMID- 10670486
TI - Progressive optic axon dystrophy and vacuslar changes in rd mice.
AB - PURPOSE: To examine how the vascular plexuses in the rd mouse retina are affected
by the loss of photoreceptors and how this compares with the Royal College of
Surgeons (RCS) rat. To examine whether the profound effects of vascular pathology
on retinal ganglion cells (RGCs) and their axons seen in RCS rats are also found
in rd mice. METHODS: Vascular patterns were studied in flatmounted and sectioned
retinas using either nicotinamide adenine dinucleotide phosphate(NADPH)
diaphorase histochemistry or vessel filling with horseradish peroxidase. Optic
axons were visualized using RT97 (an antibody against the 200-kDa neurofilament
subunit), and RGCs were labeled by retrograde transport of fluorescence label,
the Fluorogold, applied to the superior colliculus. RESULTS: The present study
showed that in the rd mouse, similar to the RCS rat, vascular complexes developed
in association with retinal pigment epithelial cells at the outer border of the
retina. The number and distribution of complexes were very different from the
rat, but as in the rat, progressive axonal dystrophy was seen in the optic fiber
layer. RGC loss, rather than being local was more broadly distributed, but some,
at least, appeared to be secondary to axonal dystrophy caused by vessels
supplying vascular formation. CONCLUSIONS: Photoreceptor loss in the rd mouse
leads to RGC axonal dystrophy and loss. The lesser degree and different
distribution of RGC loss caused by abnormal vasculature associated with vascular
formations in the outer retina in the rd mouse may be due to the early atrophy of
the deep vascular plexus in this animal.
PMID- 10670487
TI - Differential expression of cadherin adhesion receptors in neural retina of the
postnatal mouse.
AB - PURPOSE: To determine the expression pattern of multiple subtypes of cadherin
adhesion receptor in postnatal mouse neural retina. METHODS: The expression of N
cadherin, R-cadherin, cadherin-6, cadherin-8, and cadherin-11 in retinas at
postnatal days 0 to 42 was analyzed by in situ hybridization of mRNA as well as
by immunohistochemistry. RESULTS: Each cadherin was expressed by different cell
populations of the retina, and the following expression patterns were established
by postnatal day 14: in the ganglion cell layer, all these molecules were
expressed, but each occurred only in a subset of the cells. Likewise, in the
inner nuclear layer, R-cadherin and cadherin-6 and -8 were expressed by a
restricted population of amacrine cells, and cadherin-8 also by a subpopulation
of bipolar cells. All horizontal cells expressed R-cadherin, and Muller cells
expressed N-cadherin and cadherin-11. Proteins of R-cadherin and cadherin-6 were
concentrated in neuropil layers. CONCLUSIONS: The pattern of differential
expression of the five cadherins supports the idea that these molecules may play
a role in selective cell interactions within the heterogeneous cell pool of the
neural retina.
PMID- 10670488
TI - Expression of ciliary neurotrophic factor activated by retinal Muller cells in
eyes with NMDA- and kainic acid-induced neuronal death.
AB - PURPOSE: To elucidate the role of retinal Muller cells in N-methyl-D-aspartate
(NMDA)- or kainic acid (KA)induced retinal damage. METHODS: In experimental eyes,
NMDA or KA was injected into the vitreous of rat eyes. Immunohistochemistry and
western blot analysis were conducted to elucidate expression and localization of
glial fibrillary acidic protein (GFAP) and ciliary neurotrophic factor (CNTF). In
addition, the neuroprotective effects of CNTF were calculated by counting cells
in the ganglion cell layer (GCL) and by measuring the thickness of the various
retinal layers. RESULTS: Morphometric analysis of retinal damage in NMDA- and KA
injected eyes showed significant cell loss in the GCL and thinning of the inner
plexiform layer (IPL) of the retina, but not of other retinal layers.
Immunohistochemistry demonstrated disappearance and/or decrease in
immunoreactivities of calbindin- and calretinin- positive cells and their
neurites and upregulated expression of both GFAP and CNTF in experimental eyes.
Western blot analysis showed an increase in protein expression for CNTF in
retinas of experimental eyes. Confocal images and sequential localization
demonstrated colocalization of CNTF and GFAP in the inner retinal layer and
possibly in Muller cells. In addition, pretreatment with CNTF (1 microg) before
the intravitreal injection of NMDA (or KA) demonstrated that CNTF has
neuroprotective effects against NMDA- or KA-induced neuronal death in the retina.
CONCLUSIONS: These studies revealed the upregulated expression of CNTF and GFAP
in Muller cells in response to NMDA- and KA-induced neuronal death, suggesting
that production of CNTF in Muller cells may be a part of the endogenous
neuroprotective system in the retina.
PMID- 10670489
TI - Production and accumulation of thrombospondin-1 in human retinal pigment
epithelial cells.
AB - PURPOSE: To investigate the production and release of thrombospondin-1 (TSP-1), a
natural inhibitor of angiogenesis, by human retinal pigment epithelial (RPE)
cells to clarify the possible role of TSP-1 in maintaining intraocular
angiogenesis. METHODS: Human RPE cells were isolated from a human cadaveric eye
and cultured in medium with 5% newborn calf serum. TSP-1 messages in the purified
RNA of RPE cells were analyzed by reverse transcription-polymerase chain reaction
(RT-PCR). Intracellular TSP-1 peptides were detected by cytofluorographic
analysis. TSP-1 peptides in the culture medium on RPE cells were measured by
sandwich enzyme-linked immunosorbent assay (ELISA). TSP-1 specific
immunofluorescent staining was tested in RPE cells cultured on glass slides and
in a human retinal tissue specimen. RESULTS: mRNA specific for TSP-1 was found in
RT-PCR products from RPE cells, and it showed a time-dependent increase from the
beginning of the culture. Intracellular staining for TSP-1 was identified by flow
cytometry. The sandwich ELISA identified a time-dependent increase of TSP-1
peptides in the culture medium of RPE cells. Immunostaining for TSP-1 was
observed in the cytoplasm of RPE cells cultured on glass slides. Positive
immunostaining of TSP-1 was observed in the cytoplasm of the RPE layer in the
human retinal tissue specimen. CONCLUSIONS: RPE cells can produce and release TSP
1 in vitro, and TSP-1 accumulates in the cytoplasm of RPE cells in vivo as well
as in vitro. The production of TSP-1 by RPE cells is influenced by the state of
proliferation and/or cell density. TSP-1 appears to be an important control
factor in retinal and choroidal neovascularization.
PMID- 10670490
TI - Rapid upregulation of fibroblast growth factor receptor 1 (flg) by rat
photoreceptor cells after injury.
AB - PURPOSE: To determine the mechanism by which basic fibroblast growth factor
(bFGF) exerts its neuroprotective effects on degenerating or injured
photoreceptors. METHODS: Confocal immunofluorescence microscopy was used to
identify sites of bFGF and FGF receptor 1 (FGFR1) expression after focal injury
or experimental retinal detachment in adult rats. FGFR1 expression was analyzed
immunohistochemically and at the transcription level in single photoreceptor
cells, after reverse transcription (RT), using the polymerase chain reaction
(PCR). Real time quantitative RT-PCR was used to measure changes in FGFR1 mRNA
levels in the retina in response to injury or detachment. RESULTS: Confocal
immunofluorescence observations showed that FGFR1 immunoreactivity in the rat
retina is concentrated primarily in the perinuclear cytoplasm of photoreceptor
cell bodies. Reverse transcription of total RNA derived from dissociated rat
photoreceptor cells, followed by amplification of FGFR1 cDNA using the PCR,
verified the presence of FGFR1 transcripts in normal rat photoreceptor cells; in
contrast, no evidence of bFGF transcription was detected. Collectively, these
results provide compelling evidence for FGFR1 gene expression by rat
photoreceptors in situ. Within hours after experimental retinal detachment or
focal injury, there is a twofold increase in FGFR1 immunoreactivity in the outer
nuclear layer that persists for at least 7 days; a similar increase in bFGF
immunoreactivity in the interphotoreceptor matrix is also apparent. This increase
in FGFR1 protein levels after detachment and injury also was confirmed by western
blot analysis. Real time quantitative RT-PCR analyses revealed that a rapid
upregulation of FGFR1 mRNA occurred within 12 hours after retinal
injury/detachment, but then declined to near baseline levels by 24 hours.
CONCLUSIONS: This body of evidence strongly suggests that the photoreceptor
rescue effect elicited by retinal injury as well as by injection of exogenous
bFGF is mediated, at least in part, by upregulation of the FGFR1 by the
photoreceptor cells.
PMID- 10670491
TI - The use of adenovirus-mediated gene transfer to develop a rat model for
photoreceptor degeneration.
AB - PURPOSE: To investigate the effects of recombinant adenovirus-mediated
downregulation of cathepsin S (CatS) on the retinal pigment epithelium and/or
neural retina in vivo. METHODS: The expression of green fluorescent protein (gfp)
after subretinal injection of a recombinant adenovirus, Ad.gfp, into rat eyes was
first established by in vivo fundus fluorescence photography and fluorescence
microscopy. The autofluorescent debris accumulation in Ad.CatSAS (recombinant
adenovirus carrying the antisense CatS gene)injected rat eyes was monitored by
fluorescence microscopy, and the antisense CatS RNA expression was demonstrated
by in situ hybridization. Changes in the retinal morphology were assessed by
light microscopy. ResuLTS. The gfp expression was present in 30% to 90% of the
injection area at 3 days and was absent 9 days after Ad.gfp injection. In
Ad.CatSAS-injected eyes, the expression of antisense CatS RNA was demonstrated by
in situ hybridization. Autofluorescent debris accumulation was significantly
higher in Ad.CatSAS-injected eyes than in control eyes. The shortening of
photoreceptor outer segments in Ad.CatSAS-injected eyes coincided with intense
autofluorescent debris accumulation. The number of layers of photoreceptor cells
decreased with time and were 11, 9, and 8 at 7, 14, and 28 days after Ad.CatSAS
injection, respectively. In control eyes, the number of layers of photoreceptor
cells (14) remained unchanged. CONCLUSIONS: These results demonstrate that
recombinant adenovirus-mediated transient modulation of gene expression in
retinal pigment epithelial (RPE) cells could induce changes in the retina, and,
in spite of the low expression of endogenous CatS in RPE cells, this enzyme plays
an important role in maintenance of normal retinal function.
PMID- 10670492
TI - Antisense knockdown of GLAST, a glial glutamate transporter, compromises retinal
function.
AB - PURPOSE: To elucidate the role of the glial glutamate transporter GLAST, in the
regulation of retinal function. METHODS: Antisense oligonucleotides to GLAST were
injected intravitreally into the left eye of Wistar rats. Sense oligonucleotides
(control) were injected into the right eye over a period of 3 days. Scotopic
flash electroretinograms were recorded over a 20-day period. To assay whether the
antisense oligonucleotides caused a reduction in the expression or the activity
of GLAST, retinas were exposed to D-aspartate, a nonendogenous substrate of
glutamate transporters. The retinas were immunolabeled with specific antibodies
for D-aspartate. Retinal GLAST and glutamate distributions also were determined
immunocytochemically. RESULTS: Antisense oligonucleotides markedly suppressed the
electroretinogram b-wave, whereas sense oligonucleotides had no significant
effect. Significant changes in the electroretinogram were apparent 5 days after
injection of antisense oligonucleotide and were sustained for at least 20 days. A
marked reduction of D-aspartate uptake into Muller cells of retinas that had been
exposed to the antisense oligonucleotides 5 days previously suggests a reduction
of GLAST activity. The retinas, however, displayed no evidence of excitotoxic
neuronal degeneration, and the distribution of glutamate was unaffected by
antisense treatment. CONCLUSIONS: The observed lack of neuronal degeneration
suggests that reduced glutamate uptake into Muller cells does not cause
excitotoxic tissue damage. A direct perturbation of glutamatergic signaling is
more likely, because the rapid clearance of glutamate is necessary for light
elicited signaling between photoreceptors and bipolar cells. This suggests that
GLAST is essential for the maintenance of normal retinal transmission.
PMID- 10670493
TI - Bone morphogenetic proteins-2 and -4: negative growth regulators in adult retinal
pigmented epithelium.
AB - PURPOSE: To determine the relative level and localization of bone morphogenetic
protein (BMP-4 mRNA in the retina and retinal pigmented epithelium (RPE) under
normal and pathologic conditions, to seek clues regarding possible functions.
METHODS: Clones isolated from an RPE cDNA library were sequenced and used as
probes for northern blot analysis. Expression in the retina and RPE was
investigated in mouse models using reverse transcription-polymerase chain
reaction (RT-PCR) and in situ hybridization. The effect of recombinant proteins
on RPE proliferation was investigated by thymidine incorporation. RESULTS: Bovine
clones with high homology to BMP-2 and BMP4 were isolated from a subtracted RPE
cDNA library. Northern blot analysis using the clones as probes demonstrated
abundant and differential expression in adult bovine RPE, but with RT-PCR and in
situ hybridization, expression was also demonstrated in mouse retinal neurons. In
mice with oxygen-induced ischemic retinopathy there was a striking decrease in
BMP-4 mRNA in the retina within 6 hours of the onset of hypoxia that was
maintained for at least 5 days. In mice with inherited photoreceptor
degeneration, there was a dramatic decrease in BMP4 mRNA in retina and RPE during
and after the degeneration. mRNA for the type II BMP receptor was observed in
freshly isolated and cultured RPE cells, isolated retina, and freshly isolated
bovine aortic endothelial cells. Thymidine incorporation in early-passage RPE
cells showed a 14-fold stimulation above control with 5% serum that was decreased
to 322%, 393%, and 313% in the presence of BMP-2 (10 ng/ml), BMP4 (10 ng/ml), and
transforming growth factor (TGF)-,1 (2 ng/ml), respectively. CONCLUSIONS: BMP-2
and BMP-4 may serve as negative growth regulators in the retina and RPE that are
downregulated by injury, to allow tissue repair. Modulation of expression of the
BMPs may provide a means to control the exaggerated wound repair that occurs in
proliferative retinopathies.
PMID- 10670494
TI - Human platelet suspension stimulates porcine retinal glial proliferation and
migration in vitro.
AB - PURPOSE: To characterize the cellular and molecular mechanisms underlying the
efficacy of autologous platelet suspension adjuvant therapy in the treatment of
macular hole. METHODS: Platelet suspensions were: paid from whole blood samples
obtained from informed volunteers. For proliferation assays, platelet suspensions
or purified growth factors were added to semi-confluent cultures of porcine real
glial cells for 24 hours, followed by [3H]thymidine for 15 hours, after which
time cells were washed, solubilized, and counted for uptake of radioactive
tracer. For cell migration assays, confluent glial cultures were scrape wounded
and maintained in the presence or absence of platelet suspension or identified
platelet constituents. Cell migration into the denuded area was scored as a
function of time. In certain cases, specific pharmacologic inhibitors of growth
factor action were added at the same time as platelet adjuvant or growth factors.
RESULTS: Platelet suspension adjuvant induced strong mitogenic and chemotactic
responses in cultured glia, in a dose-dependent manner. Maximal incorporation of
thymidine was two- to threefold that of control levels, with an ED50
approximately 5 x 10(6) platelets/ml, and migration was enhanced up to 80-fold
after 48 hours. Platelet suspension-induced proliferation was completely blocked
by addition of 25 microM genistein, a tyrosine kinase receptor inhibitor.
However, the same concentration only partially blocked the cell migration
response. Addition of any single growth factor or protein identified from ELISA
analysis, or a combination of all factors, did not significantly stimulate
proliferation or cell migration. CONCLUSIONS: Human platelet suspensions exert
both proliferative and chemotactic influences on retinal glial cells in vitro,
suggesting that the same responses may occur in platelet-induced macular hole
repair in humans. Growth factors or proteins that have been identified within the
suspensions do not mimic these responses in vitro, implying that additional
currently unidentified trophic activities are also present.
PMID- 10670495
TI - Noninvasive assessment of retinal function in rats using multifocal
electroretinography.
AB - PURPOSE: To assess the applicability of multifocal electroretinograms (mfERGs)
for evaluation of function in this small-eyed animal with a rod-dominant retina
that is often used to model retinal diseases. METHODS: Noninvasive monocular
mfERGs were recorded in anesthetized albino (Sprague-Dawley) and pigmented (Long
Evans) rats. Achromatic stimuli subtending a 49 degrees by 53 degrees field
consisted of 61 hexagons that were generated and presented (at varying rates and
luminances) using a Visual Evoked Response Imaging System (VERIS; EDI, San Mateo,
CA). The VERIS also was used to calculate individual responses and for analysis.
RESULTS: mfERGs were recorded from pigmented and albino rats by slowing the rate
of stimulus presentation to allow for the slow recovery time of the rod system.
In each rat strain, responses varied systematically with changes in stimulus
parameters. Peak response amplitude increased as the rate of stimulation was
slowed and as stimulus luminance was increased. Response latency decreased as
stimulus intensity was increased. The local nature of the response was assessed
by several independent measures. CONCLUSIONS: The present work demonstrated the
feasibility and limitations of using mfERG to assess topographical changes in the
rat retina. It showed that despite the problems of the unavoidable self-adapting
nature of the stimulus, the small eye of the animal, and the high potential for
light scatter within the retina, multifocal responses with a good signal-to-noise
ratio can be obtained from the rat.
PMID- 10670496
TI - Comments on vasectomy closure techniques.
PMID- 10670498
TI - Comments on vasectomy closure techniques.
PMID- 10670497
TI - Comments on vasectomy closure techniques.
PMID- 10670499
TI - Who should operate in carotid disease?
PMID- 10670500
TI - Controversy in otitis media management: should we follow the CDC recommendations?
PMID- 10670501
TI - Acute otitis media caused by resistant pneumococci.
PMID- 10670502
TI - Topical therapy for acne.
AB - Acne is a common problem in adolescents and young adults. The disorder is caused
by abnormal desquamation of follicular epithelium that results in obstruction of
the pilosebaceous canal. This obstruction leads to the formation of comedones,
which can become inflamed because of overgrowth of Propionibacterium acnes.
Topical retinoids such as tretinoin or adapalene are effective in many patients
with comedonal acne. Patients with inflammatory lesions benefit from treatment
with benzoyl peroxide, azelaic acid or topical antibiotics. Frequently, the use
of comedonal and antibacterial agents is required.
PMID- 10670503
TI - Urinary catheter management.
AB - The use of urinary catheters should be avoided whenever possible. Clean
intermittent catheterization, when practical, is preferable to long-term
catheterization. Suprapubic catheters offer some advantages, and condom catheters
may be appropriate for some men. While clean handling of catheters is important,
routine perineal cleaning and catheter irrigation or changing are ineffective in
eliminating bacteriuria. Bacteriuria is inevitable in patients requiring long
term catheterization, but only symptomatic infections should be treated.
Infections are usually polymicrobial, and seriously ill patients require therapy
with two antibiotics. Patients with spinal cord injuries and those using
catheters for more than 10 years are at greater risk of bladder cancer and renal
complications; periodic renal scans, urine cytology and cystoscopy may be
indicated in these patients.
PMID- 10670504
TI - Update on the prevention and treatment of sexually transmitted diseases.
AB - The Centers for Disease Control and Prevention updated its guidelines for the
treatment of sexually transmitted diseases. The guidelines include the following
information: recommendations for hepatitis A immunization and expanded
indications for hepatitis B vaccination; updated diagnostic criteria for pelvic
inflammatory disease and parenteral treatment regimens; information on two
additional antiviral agents for the treatment of genital herpes; a recommendation
for use of a single 1-g dose of azithromycin (Zithromax) to treat urethritis and
chlamydial cervicitis; information on the use of quinolones in the treatment of
gonococcal infections; information on podofilox and imiquimod, which are both
patient-applied medications, in the treatment of noncervical human papillomavirus
infection; updated guidelines for the prevention and detection of congenital
syphilis; and information on how to prevent the spread of sexually transmitted
diseases by educating patients about the importance of changing their sexual
behaviors. To have a significant impact on the current rate of transmission of
sexually transmitted diseases, family physicians should develop a plan to
integrate the guidelines into their practices.
PMID- 10670505
TI - Perianal streptococcal dermatitis.
AB - Perianal streptococcal dermatitis is a bright red, sharply demarcated rash that
is caused by group A beta-hemolytic streptococci. Symptoms include perianal rash,
itching and rectal pain; blood-streaked stools may also be seen in one third of
patients. It primarily occurs in children between six months and 10 years of age
and is often misdiagnosed and treated inappropriately. A rapid streptococcal test
of suspicious areas can confirm the diagnosis. Routine skin culture is an
alternative diagnostic aid. Treatment with amoxicillin or penicillin is
effective. Follow-up is necessary, because recurrences are common.
PMID- 10670506
TI - When to operate in carotid artery disease.
AB - Carotid endarterectomy has proved to be beneficial in the prevention of stroke in
selected patients. The procedure is indicated in symptomatic patients with
carotid-territory transient ischemic attacks or minor strokes who have carotid
artery stenosis of 70 to 99 percent. With a low surgical risk, carotid
endarterectomy provides modest benefit in symptomatic patients with carotid
artery stenosis of 50 to 69 percent. Platelet antiaggregants and risk factor
modification are recommended in symptomatic patients with less than 50 percent
stenosis. In the Asymptomatic Carotid Atherosclerosis Study, carotid
endarterectomy was beneficial in patients who had asymptomatic carotid artery
stenosis of 60 percent or greater and whose general health made them good
candidates for elective surgery, provided that the arteriographic and surgical
complication rates were low. However, in asymptomatic patients, surgery reduced
the absolute risk of stroke by only 1 percent per year.
PMID- 10670507
TI - Knee braces: current evidence and clinical recommendations for their use.
AB - Methods of preventing and treating knee injuries have changed with the rapid
development and refinement of knee braces. Prophylactic knee braces are designed
to protect uninjured knees from valgus stresses that could damage the medial
collateral ligaments. However, no conclusive evidence supports their
effectiveness, and they are not recommended for regular use. Functional knee
braces are intended to stabilize knees during rotational and anteroposterior
forces. They offer a useful adjunct to the treatment and rehabilitation of
ligamentous knee injuries. Patellofemoral knee braces have been used to treat
anterior knee disorders and offer moderate subjective improvement without
significant disadvantages. Additional well-designed studies are needed to
demonstrate objectively the benefits of all knee braces. Knee braces should be
used in conjunction with a rehabilitation program that incorporates strength
training, flexibility, activity modification and technique refinement.
PMID- 10670508
TI - Smell and taste disorders: a primary care approach.
AB - Smell and taste disorders are common in the general population, with loss of
smell occurring more frequently. Although these disorders can have a substantial
impact on quality of life and may represent significant underlying disease, they
are often overlooked by the medical community. Patients may have difficulty
recognizing smell versus taste dysfunction and frequently confuse the concepts of
"flavor" and "taste." While the most common causes of smell disturbance are nasal
and sinus disease, upper respiratory infection and head trauma, frequent causes
of taste disturbance include oral infections, oral appliances (e.g., dentures),
dental procedures and Bell's palsy. Medications can interfere with smell and
taste, and should be reviewed in all patients with reported dysfunction. In
addition, advancing age has been associated with a natural impairment of smell
and taste ability. A focused history and a physical examination of the nose and
mouth are usually sufficient to screen for underlying pathology. Computed
tomographic scanning or magnetic resonance imaging of affected areas, as well as
commercially available standardized tests, may be useful in selected patients.
The causes of olfactory dysfunction that are most amenable to treatment include
obstructing polyps or other masses (treated by excision) and inflammation
(treated with steroids). Enhancement of food flavor and appearance can improve
quality of life in patients with irreversible dysfunction.
PMID- 10670509
TI - 1999 USPHS/IDSA Guidelines for the Prevention of Opportunistic Infections in
Persons Infected with HIV: Part II. Prevention of the first episode of disease.
U.S. Department of Health and Human Services, Public Health Service, Centers for
Disease Control and Prevention. U.S. Public Health Service/Infectious Diseases
Society of America.
PMID- 10670510
TI - The U.S. blood supply.
PMID- 10670511
TI - American Thoracic Society issues consensus statement on sarcoidosis.
PMID- 10670512
TI - ACOG practice bulletin on management of herpes in pregnancy. American College of
Obstetricians and Gynecologists.
PMID- 10670513
TI - AHA examines cardiovascular problems in diabetes. American Heart Association.
PMID- 10670514
TI - Semen cryopreservation in domestic animals: a damaging and capacitating
phenomenon.
PMID- 10670515
TI - Risky business? Helping the HIV-infected have babies.
PMID- 10670516
TI - Rationale, interpretation, validation, and uses of sperm function tests.
PMID- 10670517
TI - DNA integrity in human spermatozoa: relationships with semen quality.
AB - The literature contains conflicting evidence regarding the existence of DNA
damage in spermatozoa from infertile male patients. To examine this phenomenon,
we have studied ejaculated spermatozoa from normozoospermic semen donors and from
a group of the unselected male partners of couples attending an infertility
clinic for initial investigation. Classical semen analysis according to World
Health Organization (WHO) guidelines was undertaken with computer-assisted sperm
analysis (CASA). Spermatozoa were prepared by sequential washing and
centrifugation and were analyzed for DNA fragmentation using three assays: 1) a
single-cell gel electrophoresis (comet) assay, 2) in situ nick translation with
prior chemical decondensation (ISNT-decondensed), and 3) in situ nick translation
without prior chemical decondensation (ISNT-condensed). In addition, reactive
oxygen species (ROS) generation by spermatozoa was measured, and seminal plasma
was analyzed for its total reactive antioxidant potential (TRAP). When the donor
and patient groups were compared, the latter had lower levels of semen quality
and higher levels of DNA damage, which was particularly apparent using the comet
assay. Highly significant negative correlations were observed between DNA
fragmentation, detected by all three assays, and semen quality, particularly
sperm concentration. In addition, multiple regression analysis indicated that
other attributes of semen quality, such as sperm movement and ROS generation,
were also related to DNA damage. We conclude that a significant proportion of
infertile men have elevated levels of DNA damage in their ejaculated spermatozoa.
PMID- 10670518
TI - In vitro and xenogenous capacitation-like changes of fresh, cooled, and
cryopreserved stallion sperm as assessed by a chlortetracycline stain.
AB - Like the human female, the mare experiences reproductive tract pathology that may
sometimes be circumvented by the use of assisted reproductive technologies
(ARTs). One such technology, gamete intrafallopian transfer (GIFT), may be used
in mares that exhibit ovulatory, oviductal, or uterine abnormalities that limit
the use of common ARTs, such as embryo transfer. Homologous GIFT has been
successfully performed in the horse; however, the logistics, costs, and
associated risks of surgically transferring gametes to the oviducts of a
recipient mare are considerably high. Use of a less costly species in a
heterologous or xenogenous procedure would therefore be beneficial. This study
represents the preliminary investigation into the use of sheep as recipients for
xenogenous GIFT procedures using equine gametes. We investigated the capacitation
response of fresh, cooled, or frozen stallion sperm after 1) in vivo incubation
in the reproductive tract of estrous and anestrous ewes as well as 2) in vitro
incubation in a modified Krebs/ Ringer extender at 37 degreesC with and without
the addition of heparin at 10 IU/mL for up to 8 hours. A chlortetracycline (CTC)
fluorescent stain was used to assess the capacitation response of sperm. Findings
indicated that oviductal fluid samples recovered from estrous ewes had
significantly higher numbers of sperm exhibiting capacitation-like staining
patterns when compared to samples recovered from anestrous ewes (P < .05). Fresh
semen yielded higher capacitation-like staining patterns after in vivo incubation
than did frozen-thawed or cooled samples. A transition from majority CTC
unreacted sperm to majority CTC non-acrosome intact sperm was demonstrated for
both in vivo and in vitro studies. In vitro incubation of stallion sperm with
heparin did not result in an increased capacitation-like staining response over
time when compared with nonheparinized samples. Results from this study suggest
that xenogenous capacitation of stallion sperm may occur in the estrous ewe.
PMID- 10670519
TI - Comparison of zinc concentrations in blood and seminal plasma and the various
sperm parameters between fertile and infertile men.
AB - The aim of the study was to examine the relationships between concentrations of
zinc in blood and seminal plasma and sperm quality among infertile and fertile
men. One hundred seven male (infertile group) partners of couples who were
undergoing investigation for infertility with no known cause for the infertility
and 103 men (fertile group) whose wives were pregnant at the time of the study
were recruited. The subjects' blood and seminal plasma concentration of zinc were
determined by atomic absorption spectroscopy. Except for semen volume, all the
other semen parameters for the infertile men were significantly lower than those
for the fertile group. The geometric means of the seminal plasma zinc
concentration were significantly lower in the infertile group compared with those
in the fertile group; 183.6 mg/L (range, 63-499) versus 274.6 mg/L (range, 55
420). There were no significant differences in the geometric means of the blood
zinc concentration between the 2 groups. Seminal plasma zinc concentration was
significantly correlated with sperm density (r = 0.341, P < .0001), motility (r =
0.253, P < .0001), and viability (r = 0.286, P < .0001). On the basis of the
findings of this study and those of other reports, zinc may contribute to
fertility through its positive effect on spermatogenesis.
PMID- 10670520
TI - Spontaneous hyperplasia of the ventral lobe of the prostate in aging genetically
hypertensive rats.
AB - Recent studies have shown that the prostatic autonomic innervation takes part in
its homeostasis and growth. Other works showed that spontaneously hypertensive
rats (SHR) show excessive sympathetic activity, accompanied by lower urinary
tract symptoms, increased growth capacity of prostatic stromal cells, and
increased levels of androgens and their receptors. Furthermore, young SHR were
reported to present incipient stages of benign prostatic hyperplasia (BPH). The
aim of the present study was to examine whether this strain indeed develops
spontaneous BPH with age, and can thus serve as a genuine natural model for this
disorder. For this purpose, ventral lobes of prostates of one-year-old, male SHR
and their normotensive counterparts, Wistar Kyoto (WKY) rats, were examined
histopathologically, and the degree of hyperplasia was evaluated according to a
score-chart protocol (histoscore). SHR exhibited severe adenomatous spontaneous
BPH, characterized by piling-up of epithelial cells, with papillary formations,
accompanied by a mild increase in the amount of fibrocytes and smooth muscle
cells in the stroma. This was reflected by histoscore values of 38 +/-2.
Thickening of prostatic arterioles also was noted, as well as mild chronic
inflammatory exudate. WKY rats did not show any of these features of BPH despite
their age (histoscore 17 +/- 3, significantly different from that of SHR). We
conclude that SHR can serve as a rodent model for the spontaneous development of
BPH with age, most probably due to the excessive neuroendocrine activity
characteristic of this rat strain.
PMID- 10670521
TI - Correlation of CASA velocity and linearity parameters with sperm mobility
phenotype in turkeys.
AB - Since all domestic turkeys are produced through artificial insemination, a
measurable sperm characteristic that would be predictive of fertility would allow
for the culling of poor males, resulting in improved reproductive efficiency. The
sperm mobility test (SMT), which quantifies sperm penetration into an Accudenz
solution, has been shown to correlate highly with fertilization potential of
individual turkeys. Since this sire-selection test is based on the differences in
sperm mobility between whole ejaculates from individual males, the objective of
this study was to determine whether specific sperm velocity parameters would
correlate with the SMT and to determine whether these characteristics could
account for phenotypic differences in sperm mobility observed between males. The
SMT was used to rank males within a flock (n = 110) in triplicate and to classify
them into high, average, and low sperm mobility phenotypes on the basis of the
sperm mobility index. Several sperm velocity parameters were evaluated for each
male by a computer-aided sperm analysis (CASA) system, the Hobson Sperm Tracker.
The types of measurements taken of 200 sperm tracks/ejaculate included the
following: curvilinear velocity (VCL), average path velocity (VAP), straight-line
velocity (VSL), linearity (LIN), beat-cross frequency (BCF), and mean angular
displacement (MAD). Significant positive correlations were found between VSL,
LIN, BCF, and sperm mobility, and a significant negative correlation was seen
between MAD and sperm mobility. Subpopulations of sperm that had penetrated the
Accudenz solution were isolated from each mobility phenotype and were analyzed by
CASA, and significant correlations were again observed between VSL, LIN, BCF, and
sperm mobility. We conclude that sperm velocity and linearity contribute to
overall sperm mobility phenotype and are important characteristics of turkey
sperm function. Key words: Motility, computer, spermatozoa.
PMID- 10670522
TI - Age-related decrease in hypothalamic gonadotropin-releasing hormone (GnRH) gene
expression, but not pituitary responsiveness to GnRH, in the male Brown Norway
rat.
AB - As is the case in humans, aging male Brown Norway (BN) rats exhibit both primary
and secondary (hypothalamic/pituitary) testicular failure. We hypothesized that
secondary testicular failure in aging BN rats is due to alterations in both
hypothalamic and pituitary function. In order to determine whether gonadotropin
releasing hormone (GnRH) gene expression is altered with aging, we compared
hypothalamic preproGnRH (ppGnRH) mRNA by in situ hybridization histochemistry and
GnRH peptide content in microdissected brain areas by radioimmunoassay in intact
(or sham-operated) young, middle-aged, and old male rats. In addition, we
determined hypothalamic-pituitary responsiveness to the removal of testicular
feedback by comparing ppGnRH messenger RNA (mRNA) and gonadotropin levels in sham
operated and orchidectomized young, middle-aged, and old rats. In sham-operated
rats, both the cellular ppGnRH mRNA content and the number of neurons expressing
ppGnRH mRNA were lower in old compared with young and middle-aged rats. In
addition, GnRH content decreased with aging in intact rats in 2 of the 3 brain
areas examined, and GnRH content tended to decrease with aging in the third
region. Morning serum luteinizing hormone (LH) levels were unchanged with aging,
whereas follicle-stimulating hormone (FSH) was significantly increased in old
compared with younger intact rats. The cellular ppGnRH mRNA content also
decreased with aging in orchidectomized rats, although the number of neurons
expressing ppGnRH mRNA was unchanged with aging in these rats. Within age groups,
the cellular ppGnRH mRNA content was higher in orchidectomized than in sham
operated rats, though there was no effect on the number of neurons expressing
GnRH. In a second study, we compared pituitary responsiveness to GnRH by
measuring serum LH and FSH levels after GnRH administration in intact BN rats of
different ages. The LH response to GnRH was unchanged with aging, whereas the FSH
response to GnRH tended to increase with aging. Despite similar LH responses, the
testosterone (T) response to GnRH declined progressively with aging. A third
study assessed age-related changes in the circadian rhythm of circulating LH, T,
and corticosterone (B) levels. LH levels over a 24-hour period decreased with
aging and tended to be lower in the morning hours in all age groups, and
circadian rhythmicity was blunted in middle-aged and old compared with young
rats. T levels over 24 hours declined progressively with aging, and these levels
showed a bimodal diurnal variation in young rats, a variation that was not
evident in older animals. B levels over a 24-hour period were lower in old than
in younger animals, and with aging, there was dampening of the amplitude of the
circadian rhythm of B. Taken together, these findings suggest that secondary
testicular failure in aging male BN rats is due in part to decreased GnRH gene
expression rather than to decreased pituitary responsiveness to GnRH. This
reduction in GnRH gene expression with aging is not dependent on testicular
feedback factors. Finally, the blunted circadian rhythmicity of LH and T
secretion with aging provides further evidence of altered hypothalamic regulation
of gonadal hormone secretion in old animals.
PMID- 10670523
TI - Transdermal electromotive multi-drug administration for Peyronie's disease:
preliminary results.
AB - The purpose of this study was to clarify the actual therapeutic potential of a
new transdermal drug delivery system (electromotive drug administration; EMDA)
for selected patients with Peyronie's disease. Forty patients with Peyronie's
disease were treated by electromotive administration of the 3-drug association
orgotein-dexamethasone-lidocaine in a double-blind, placebo-controlled, partial
crossover study (study 1). Another 25 patients were treated by EMDA with a
combination of verapamil-dexamethasone in an uncontrolled study (study 2).
Treatment sessions lasted 20 minutes each and took place 3 times a week for 3
weeks with a current of 3 mA. Patients were assessed before treatment and at 1-
and 3-month follow-up examinations. Assessments were based on sexual history,
physical examination, and dynamic color Doppler ultrasonographic results. Adverse
effects of EMDA were not reported. In study 1, the clinical results observed
after treatment proved to be significantly better than those of the placebo.
Penile pain disappeared in all patients in both studies. Penile lesion (nodule or
plaque) either disappeared or significantly improved in 79% and 90% of patients
treated by the 3- and 2-drug association, respectively. The improvement of penile
deformity also was notable although it did not match the effect observed on
penile nodules or plaque (62% and 88%, in studies 1 and 2, respectively). In both
studies, more than 80% of patients reported a definite amelioration of penile
rigidity, which paralleled the improvement of penile dynamic color Doppler
ultrasonographic parameters. Overall, the combination of verapamil-dexamethasone
achieved better clinical results than the 3-drug combination. Electromotive drug
administration is a novel technique capable of safely achieving satisfactory
results in selected patients with Peyronie's disease not only in terms of
improvement of patient's symptoms but also due to the reduced need for penile
surgery.
PMID- 10670524
TI - Androgen receptor gene polymorphism and prostate zonal volumes in Australian and
Chinese men.
AB - Prostate diseases are age and androgen dependent. The evolution of clinically
overt pathology requires decades of exposure to adult male levels of circulating
testosterone, but the precise relationship between age and androgen circulation
remains poorly understood. A marker of integrated androgen action over prolonged
periods would therefore be a valuable tool for clinical and epidemiologic
research into the origins of prostate disease. In order to evaluate these 2
factors, we have studied the CAG-repeat length polymorphism of the androgen
receptor gene and the size of the total, central, and peripheral zones of the
prostate, estimated by planimetric ultrasound in 2 populations with widely
different susceptibility to death from invasive prostate cancer. From a larger
epidemiologic study of the effects of ethnicity and migration on the origins of
prostate disease, a nested-case control study was undertaken with 50 Chinese men
living in Yue Yang, China and 50 non-Chinese men living in Sydney, Australia. All
men had undergone planimetric transrectal prostate ultrasound together with blood
sampling to determine CAG-repeat length by polymerase chain reaction and
immunoassay of plasma testosterone, estradiol, dihydrotestosterone (DHT), sex
hormone-binding globulin (SHBG), and prostate-specific antigen (PSA). Australian
men had larger central (7.9 +/- 0.4 vs 3.3 +/- 0.3 mL) and total (29.8 +/- 1.2 vs
25.5 +/- 1.1 mL) but not peripheral (22.0 +/- 0.9 vs 22.2 +/- 0.8 mL) prostate
volumes compared with Chinese men. Even after adjustment for differences in body
size (the Australian men were taller and heavier), the central-zone volume
remained lower by approximately 50% in Chinese men (P < 0.001), whereas testis
and total-prostate volumes were no longer significantly different. The length of
CAG repeats was no different between Australian men (22.5 +/- 0.5 repeats) and
Chinese men (22.5 +/- 0.5 repeats), and there was no correlation within or
between populations in CAG repeats or any measure of prostate volume or hormones.
DHT concentration was 20% lower in Chinese men compared with Australian men (1.6
+/- 0.1 vs 2.0 +/- 0.1 nmol/L, P = 0.005), a difference that persisted after age
adjustment (P = 0.039) but that was removed by adjustment for differences in
total-prostate size (P = 0.12). Blood testosterone, estradiol, SHBG, and PSA
concentrations were not different between the 2 populations. Hence, the
hypothesis is refuted that the CAG repeat polymorphism in the androgen receptor
gene (within the nonpathologic range) and the central-prostate zone volume might
be markers of long-term androgen sensitivity. Whether either factor alone may
constitute a marker of androgen sensitivity remains to be established by other
means, and a long-term marker of integrated androgen action suitable for clinical
and epidemiologic research is still lacking.
PMID- 10670525
TI - The mouse sperm glycine receptor/chloride channel: cellular localization and
involvement in the acrosome reaction initiated by glycine.
AB - Previously, we reported that glycine initiates the in vitro acrosome reaction
(AR) of porcine and human sperm by a mechanism that includes the glycine
receptor/Cl- channel (GlyR) and that this receptor/channel is required for the
zona-pellucida-initiated AR. Because mouse sperm are important tools in the study
of fertilization, we investigated whether glycine initiated the mouse sperm AR
and whether the sperm GlyR was involved in that initiation. Glycine (250 microM
to 1 mM) initiated the AR of capacitated but not noncapacitated mouse sperm. The
glycine-initiated AR was significantly inhibited by 50 nM strychnine, a neuronal
GlyR antagonist. The neuronal GlyR agonists taurine and beta-alanine did not
initiate the AR at 1 mM or 5 mM. A monoclonal antibody against the rat spinal
cord GlyR significantly inhibited the glycine-initiated AR but not the
spontaneous AR. Indirect immunofluorescence localization studies with that
monoclonal antibody and postfixed live sperm detected 3 patterns of
immunoreactivity involving 2 sites in the periacrosomal plasma membrane. These
patterns were as follows: type A localization on the plasma membrane overlying
the tip of the anterior acrosomal region; type B localization on the plasma
membrane overlying the posterior part of the acrosomal equatorial segment and/or,
in acrosome-reacted sperm, the posterior part of the modified equatorial segment;
and type C localization that included both type A and type B. Type A and type C
localization were only observed on the acrosome-intact sperm. During
capacitation, the number of the sperm showing type A localization increased. Our
results demonstrate that mouse sperm provide an excellent model for studying the
role of the GlyR in the acrosome reaction.
PMID- 10670526
TI - Morphologic changes in efferent ductules and epididymis in estrogen receptor
alpha knockout mice.
AB - Estrogen has been shown to have an important role in fluid reabsorption in
efferent ductules of the testis. Our previous study of the estrogen receptor
alpha knockout mouse (ERKO) showed that the efferent ductules and rete testis
were primary targets of estrogen receptor function. In the present study, a more
comprehensive evaluation of the ERKO male reproductive tract was performed to
determine the severity of effects in efferent ductules as well as the epididymis.
The following observations were found in ERKO males: 1) blind-ending efferent
ductules were more prevalent in ERKO than in wild type (WT) tissues; 2) glycogen
containing cells were observed at the rete testis-efferent ductule junction; 3)
the tubular diameters of the efferent ductules and initial segment epididymides
were dilated; 4) efferent ductules were dilated between 130 to 300% over wild
type ductules; 5) efferent ductule epithelial height was reduced nearly 50%; 6)
microvilli of nonciliated cells of efferent ductules were 64% shorter in length;
7) cilia were reduced in number; 8) initial segment epithelium was displaced into
regions adjacent to the rete testis and in short segments of the common region of
efferent ductule; 9) apical, narrow, and clear cells of the epididymis also were
abnormal in some regions; 10) in the corpus and cauda regions, sperm granulomas
were noted in one third of the ERKO males. In conclusion, the entire reproductive
tract is affected in ERKO males. The cells showing the greatest effects were
estrogen receptor-positive cells. It appears that in the ERKO mouse there are
developmental anomalies that must be considered separately from adult
dysfunctional changes in the male reproductive tract.
PMID- 10670527
TI - Circulating and luminal testicular factors affect LRP-2 and Apo J expression in
the epididymis following efferent duct ligation.
AB - Apolipoprotein J (clusterin or sulfated glycoprotein-2) has been shown to be
secreted by the epididymal principal cells, whereupon it binds to sperm in the
lumen. Apolipoprotein J also is endocytosed by principal cells along the
epididymis. Recently, it has been demonstrated that low-density lipoprotein
receptor-related protein-2 (LRP-2) mediates the endocytosis of Apo J and is
present in the epididymis. The purpose of the present study was to determine the
factors regulating the synthesis of these 2 proteins in various experimentally
treated animals. The epididymides of adult rats were fixed with Bouin's fluid and
examined with anti-Apo J and anti-LRP-2 antibodies by a light microscope
immunocytochemical method. In normal adult animals, expression of Apo J was
evident in principal cells of all epididymal regions except the proximal initial
segment. Diffuse cytoplasmic staining indicated Apo J secretion. Reactive apical
vesicles, presumably endosomal in nature, suggested endocytosis of Apo J.
Lipoprotein receptor-related protein-2 expression was solely apical in nature and
was seen as an intense apical band in principal cells of all regions except the
proximal and distal initial segment and distal caput regions of the epididymis.
Hypophysectomy, up to 28 days after the procedure, did not affect expression of
Apo J or LRP-2 in principal cells along the entire epididymis. Orchidectomy, with
or without testosterone replacement at all time intervals examined, also did not
affect LRP-2 expression along the entire epididymis. This also was noted for Apo
J expression in all regions except the proximal initial segment. Thus, expression
of these 2 proteins does not appear to be regulated by testicular or pituitary
factors. In contrast, bilateral as well as unilateral (intact and ligated sides)
efferent duct ligation resulted in dramatic differences in LRP-2 and Apo J
expression in principal cells in the various epididymal regions. In the case of
LRP-2, a complete absence of reaction was noted in principal cells along the
entire epididymis. As for Apo J, expression in the distal initial segment,
intermediate zone, and caput region remained unchanged compared with that in
normal adult animals, whereas in the corpus and cauda epididymides, results of
cytoplasmic staining were negligible. These results suggest that under conditions
of efferent duct ligation, a circulating factor emanates from the testis to
inhibit expression of LRP-2 and Apo J in these epididymal regions. Furthermore,
because Apo J was affected in a region-specific manner, unlike the case for LRP
2, different factors appear to be involved for each protein. These factors may be
produced to inhibit proteins from being synthesized by the epididymis in the
absence of luminal testicular input and may exist in cases of congenital and
pathologic epididymal tubule blockages as well as after vasectomy. In the case of
immunostaining for Apo J in the proximal initial segment only, normally
unreactive principal cells in control adult animals became intensely reactive
after orchidectomy as well as bilateral and unilateral (ligated side only)
ligation. As this was not the case for hypophysectomized animals and the intact
side of unilateral efferent duct-ligated animals, it is suggested that a
testicular factor entering via the lumen of the efferent ducts serves to inhibit
Apo J expression in this area. The present data also reveal that after efferent
duct ligation, there are circulating factors that inhibit Apo J expression in a
region-specific manner (corpus and cauda) and that inhibit LRP-2 expression along
the entire epididymis and that these are derived from the testis. Furthermore,
the data reveal that a testicular luminal factor appears to inhibit Apo J
expression in the proximal initial segment of normal adult animals. Key words:
Principal cells, orchidectomy, glycoprotein 330, clusterin, sulfated glycoprotein
2.
PMID- 10670528
TI - Semen quality and human fertility: a prospective study with healthy couples.
AB - Measures of semen quality are used as surrogate measures of male fertility in
clinical andrology, reproductive toxicology, epidemiology, and risk assessment.
However, only limited data are available to relate those measures to fertility.
This prospective study with 210 reproductive-age couples was conducted to provide
information on the value of semen quality measures for predicting human male
fertility potential and for development of models to estimate the effects of
changes in semen quality on fertility in a given population for risk assessment.
Couples without known risk factors for infertility and who had discontinued
contraception to have a child were accepted. The study followed each couple for
up to 12 menstrual cycles while they attempted to conceive and evaluated semen
quality measures from multiple ejaculates per man with known abstinence
intervals. For each cycle, the day of ovulation was predicted, and the couple was
advised to have intercourse multiple times on that day and on the days around it.
Among the demographic variables assessed, parity, contraception status prior to
entering the study, male education level, and male smoking were associated
significantly with 12-cycle pregnancy rate. Several semen quality measures also
were associated significantly with pregnancy rate, with percentage
morphologically normal sperm by strict criteria and measures involving total
number of sperm showing particularly strong associations. Localized regression
smoothing plots of semen quality data against proportion of couples pregnant
suggested levels below which fertility declines for several semen quality
measures. These results have applications in both clinical andrology and in
assessment of risk to male fecundity from environmental or pharmaceutical
exposures. In particular, they contribute information on behavior of fertility
with varying semen quality and can allow development of models to predict effects
on fertility in populations from decrements in semen quality.
PMID- 10670530
TI - Establishment of the Male Reproductive Biology Club.
PMID- 10670529
TI - Maturation of epididymal spermatozoa in the nondomesticated guinea pigs Cavia
aperea and Galea musteloides.
AB - The physiological changes occurring in spermatozoa in the male reproductive tract
of 2 nondomesticated species of South American guinea pigs with different mating
systems were studied. Cavia aperea, the wild ancestor of the domesticated guinea
pig, has a polygynous mating system, whereas Galea musteloides exhibits
promiscuous mating behavior. The epididymis of both species resembled that of the
domesticated guinea pig, with a swathe of tubule convolutions (linking the 2
major parts of the organ) that was of smaller size in Cavia but not Galea. Higher
relative epididymal weight was demonstrated in the promiscuous species. During
their journey through the epididymis, spermatozoa from Galea developed their
potential for motility expression more proximally than did those of Cavia, but
motility developed into forward progression in the same region in both species.
The maximal velocities exhibited by mature Cavia sperm in vitro were greater than
those of Galea. Spermatozoa from Cavia were twice the length of those from Galea,
they had larger heads, and the acrosomes of single sperm were more sensitive to
disruption during morphological preparation. Only in Cavia did agglutination of
sperm into rouleaux occur, after the potential for motility had been developed.
Migration of the cytoplasmic droplet along the midpiece occurred in the same
regions in both species and before agglutination in Cavia. It is suggested that
the male's reproductive strategy (polygyny vs promiscuity) dictates the size of
the testis and epididymis, whereas the female's reproductive physiology (induced
ovulation vs cyclicity) influences the posttesticular development of sperm
morphology and motility in the epididymis.
PMID- 10670531
TI - The American Society of Andrology.
PMID- 10670532
TI - Over population is the biggest problem faced by our planet.
PMID- 10670533
TI - Andrology as a discipline.
PMID- 10670534
TI - The future for andrology.
PMID- 10670535
TI - The future of andrology in the next millennium.
PMID- 10670536
TI - The future of andrology.
PMID- 10670537
TI - What may transpire in the field of andrology in the early part of the next
century.
PMID- 10670538
TI - The future of ASA. American Society of Andrology.
PMID- 10670539
TI - The future of andrology is bright.
PMID- 10670541
TI - The future of andrology.
PMID- 10670540
TI - The future of andrology.
PMID- 10670542
TI - The future of andrology.
PMID- 10670544
TI - The future of andrology.
PMID- 10670543
TI - Andrology at the time of the second millennium.
PMID- 10670545
TI - Risk factors for human herpesvirus 8 seropositivity and seroconversion in a
cohort of homosexual men.
AB - Sexual and nonsexual modes of transmission of human herpesvirus 8 (HHV8) have
been suggested, but specific routes remain unclear. Therefore, the objective of
this study was to assess risk factors for HHV8 seropositivity and determine
specific sexual practices associated with HHV8 seroconversion. Sera from 1,458
homosexual men (Amsterdam Cohort Study, 1984-1996) were tested for antibodies to
HHV8 with a modified version of an enzyme immunoassay, using recombinant HHV8
lytic phase capsid (ORF65) and latent phase nuclear (ORF73) proteins. HHV8
seroprevalence at study entry was 20.9% (305/1,458); was highest among those with
positive human immunodeficiency virus (HIV) status, no steady partner, and
southern European or Latin American nationality; and increased with older age and
higher number of sexual partners. During follow-up, 215 men seroconverted for
HHV8 (incidence: 3.6/100 person-years). Both prevalence and incidence rates
remained more or less stable during the study period. Orogenital insertive sex
(odds ratio (OR) = 5.95; 95% confidence interval (CI): 2.88, 12.29) or orogenital
receptive sex (OR = 4.29; 95% CI: 2.11, 8.71) with more than five partners in the
past 6 months, older age (OR = 2.89; 95% CI: 1.13, 7.34, when older than 45
years), and preceding HIV infection (OR = 2.47; 95% CI: 1.53, 3.99) were
independent predictors for HHV8 seroconversion. The authors found strong evidence
for orogenital transmission of HHV8 among homosexual men.
PMID- 10670546
TI - Invited commentary: determining specific sexual practices associated with human
herpesvirus 8 transmission.
AB - Laboratory and epidemiologic studies have established human herpesvirus 8 (HHV8)
as an etiologic agent of Kaposi's sarcoma. With strong evidence linking HHV8
infection with the number of sexual partners among homosexual men, the challenge
now is to determine the specific sexual acts associated with HHV8 transmission.
Initial studies of specific practices, however, have differed in their
conclusions; the paper by Dukers et al. in this issue of the Journal is the first
to associate penile-oral intercourse with HHV8 transmission. Many sources of bias
may contribute to the conflicting findings of studies reported to date: HHV8
research still lacks an adequately specific and sensitive serologic assay;
identification of relevant exposure periods and measurement of sexual practices
are imperfect; and sufficient adjustment for confounding is problematic. These
numerous potential biases may be particularly important when trying to detect
underlying associations that may be of low-order magnitude. The study by Dukers
et al. (Am J Epidemiol 2000;151:213-24) is an important contribution to research
on HHV8 transmission, but we do not yet know enough about the possible sexual
routes of transmission to recommend avoiding any single behavior. For now, the
best prevention advice is to reinforce the more general safe sex practices that
have been promoted to prevent human immunodeficiency virus and other sexually
transmitted diseases.
PMID- 10670547
TI - Paternal military service and risk for childhood leukemia in offspring.
AB - To assess the association between paternal military service and risk for
childhood leukemia, the authors analyzed data from three case-control studies
conducted by the Children's Cancer Group from 1983 to 1993. A total of 605 acute
myeloid leukemia (AML, age < or = 18 years) cases, 2,117 acute lymphoblastic
leukemia (ALL, age < or = 14 years) cases, and 3,155 individually matched
controls were included in these studies. Paternal military history and other
exposure data were obtained in 2,343 matched case-control sets, including 1,805
ALL and 528 AML cases. Paternal general military service was not associated with
the leukemia risk. A small, but significant, increase in the risk for AML was
seen, however, among offspring of veterans who had served in Vietnam or Cambodia
(odds ratio (OR) = 1.7; 95% confidence interval (CI): 1.0, 2.9), after adjustment
for paternal education, race, income, smoking, X-ray exposure, and marijuana use.
The risk was predominantly present in children diagnosed before the age of 2 (OR
= 4.6; 95% CI: 1.3, 16.1), although there were inconsistencies in the risks
associated with length of time served and interval between service and diagnosis
of leukemia. Military service in Vietnam or Cambodia was unrelated to the risk
for ALL. The etiologic importance, if any, of these observations has yet to be
determined.
PMID- 10670548
TI - Environmental tobacco smoke and lung cancer: a case-control study in Germany.
AB - To assess the association between exposure to environmental tobacco smoke (ETS)
and lung cancer, the authors personally interviewed 292 lifelong nonsmoking lung
cancer cases (recruited from 15 hospitals in the study area) and 1,338 nonsmoking
controls (randomly selected by population registries) between 1990 and 1996 in
Germany. Subjects were asked by a standardized questionnaire about exposure to
ETS in childhood, by spouse, at work, and in transportation and social settings.
Several indicators of these different sources of exposure were investigated,
using not or low exposed subjects as the reference category. The most informative
quantification index was weighted duration of exposure (hours x level of
smokiness). No effect of ETS exposure during childhood and no clear effect of
spousal ETS were observed. However, for the highest category of exposure, clear
effects of ETS at the workplace (odds ratio (OR) = 1.93; 95% confidence interval
(CI): 1.04, 3.58), in vehicles (OR = 2.64; 95% CI: 1.30, 5.36), and from all
sources combined (OR = 1.39; 95% CI: 0.96, 2.01) were found. Adjustment for
occupational carcinogens, radon, and diet did not appreciably change the results.
These findings suggest that exposures to high levels of ETS at the workplace and
in other public indoor settings appear to be important risk factors for lung
cancer risk in nonsmokers.
PMID- 10670549
TI - Saliva cotinine levels in smokers and nonsmokers.
AB - The authors collected by mail self-reported data on smoking habits and saliva
samples that were analyzed for cotinine concentration in 222 smokers and 97
nonsmokers. Participants were members of the University of Geneva (Switzerland)
in 1995. The 207 cigarette-only smokers smoked on average 10.7 cigarettes/day and
had a median concentration of cotinine of 113 ng/ml. The cotinine concentration
was moderately associated with the number of cigarettes smoked per day (+14 ng/ml
per additional cigarette, p < 0.001, R2 = 0.45) and was 54 ng/ml higher in men
than in women after adjustment for cigarettes per day and for the Fagerstrom Test
for Nicotine Dependence. The cotinine level was not associated with the nicotine
yield of cigarettes (r= 0.08). In nonsmokers, the median concentration of
cotinine was 2.4 ng/ml. The cotinine concentration was 1.5 times higher in
nonsmokers whose close friends/spouses were smokers than in nonsmokers whose
close friends/spouses were nonsmokers (p = 0.05). A cutoff of 7 ng/ml of cotinine
distinguished smokers from nonsmokers with a sensitivity of 92.3% and a
specificity of 89.7%; a cutoff of 13 ng/ml provided equally satisfactory results
(sensitivity, 86.5%; specificity, 95.9%). This study provides evidence for the
construct validity of both questionnaires and saliva cotinine for the assessment
of active and passive exposure to tobacco smoke.
PMID- 10670550
TI - Environmental exposure to tremolite and respiratory cancer in New Caledonia: a
case-control study.
AB - A case-control study on respiratory cancers was conducted in New Caledonia (South
Pacific), where a high incidence of malignant pleural mesothelioma had been
observed. The disease pattern suggested an environmental exposure to asbestos.
The first results showed that, in some areas, tremolite asbestos derived from
local outcroppings was used as whitewash (locally named "po"). All cases
diagnosed between 1993 and 1995 (including 15 pleural mesotheliomas, 228 lung
cancers, and 23 laryngeal cancers) and 305 controls were included in the study.
Detailed information on past or present use of the whitewash, residential
history, smoking, diet, and occupation was collected. The risk of mesothelioma
was strongly associated with the use of the whitewash (odds ratio (OR) = 40.9;
95% confidence interval (CI): 5.15, 325). All Melanesian cases had been exposed.
Among Melanesian women, exposure to the whitewash was associated with an
increased risk of lung cancer (OR = 4.89; 95% CI: 1.13, 21.2), and smokers
exposed to po had an approximately ninefold risk (OR = 9.26; 95% CI: 1.72, 49.7)
compared with women who never smoked and had never used the whitewash. In
contrast, no association was noted between exposure to po and lung cancer risk
among Melanesian men, probably because of lower exposure levels. Among non
Melanesians, the numbers of exposed subjects were too small to assess the effect
of exposure to po. There was no indication of elevated risks for the other cancer
sites.
PMID- 10670551
TI - An iatrogenic epidemic of benign meningioma.
AB - Head irradiation, the acceptable mode of treatment for tinea capitis in the past,
is recognized today as a causative factor for meningioma. This treatment was
applied en mass to immigrants coming to Israel from North Africa and the Middle
East during the 1950s. In order to estimate the effect of the differential
radiation treatment on the rates of meningioma in the total population, the
authors assessed time trends of this disease in Israel over the past 40 years by
main ethnic origin. Cohort analysis shows a marked incidence rise in the North
African-born cohorts born in 1940-1954 starting from the 1980s. A similar pattern
is seen in the Middle Eastern born, although the increase is not as sharp. In
consequence, there is a crossover of the interethnic incidence curves in the 1940
1949 cohort. Comparison of the relative risk between 1940-1954 cohorts that
comprised most of the irradiated with 1930-1939 cohorts, who were largely free of
the radiation, shows that the North African born have the largest relative risk
of 4.62, followed by the Middle Eastern born, with a relative risk of 1.95, while
the European-American born have a relative risk close to 1. The differences
between the three areas of birth are statistically significant. The data
illustrate the potential risk of administering highly potent therapy for an
essentially benign disease that led, in turn, to a drastic change in the national
meningioma pattern.
PMID- 10670552
TI - Examination of the relation between periodontal health status and cardiovascular
risk factors: serum total and high density lipoprotein cholesterol, C-reactive
protein, and plasma fibrinogen.
AB - Using data from the Third National Health and Nutrition Examination Survey (1988
1994), the authors examined the relation between periodontal health and
cardiovascular risk factors: serum total and high density lipoprotein
cholesterol, C-reactive protein, and plasma fibrinogen. A total of 10,146
participants were included in the analyses of cholesterol and C-reactive protein
and 4,461 in the analyses of fibrinogen. Periodontal health indicators included
the gingival bleeding index, calculus index, and periodontal disease status
(defined by pocket depth and attachment loss). While cholesterol and fibrinogen
were analyzed as continuous variables, C-reactive protein was dichotomized into
two levels. The results show a significant relation between indicators of poor
periodontal status and increased C-reactive protein and fibrinogen. The
association between periodontal status and total cholesterol level is much
weaker. No consistent association between periodontal status and high density
lipoprotein cholesterol was detectable. Similar patterns of association were
observed for participants aged 17-54 years and those 55 years and older. In
conclusion, this study suggests that total cholesterol, C-reactive protein, and
fibrinogen are possible intermediate factors that may link periodontal disease to
elevated cardiovascular risk.
PMID- 10670553
TI - Social patterning of myocardial infarction and stroke in Sweden: incidence and
survival.
AB - Cardiovascular disease morbidity and mortality rates show marked social
patterning in industrialized countries. The aim of this study was to analyze if
not only incidence but also survival after acute myocardial infarction (AMI) and
stroke differ among socioeconomic groups. Within the framework of the population
based World Health Organization's Multinational Monitoring of Trends and
Determinants in Cardiovascular Disease (MONICA) Project, all first-ever AMI (ages
25-64 years) and stroke (ages 25-74 years) events were recorded in northern
Sweden during the period 1985-1994. The numbers of first-ever AMI and stroke
patients included in the study were 3,466 and 4,215, respectively. Incidence
rates for both AMI and stroke showed a distinct social pattern, with high rates
in workers and self-employed nonprofessionals and low rates in professionals. The
pattern was similar in men and women. In men, early survival after an AMI follows
the same socioeconomic pattern, whereas it is less clear if socioeconomic
differences in survival contribute to explain differences in mortality in AMI
among women and mortality in stroke (both sexes). The high case fatality among
male workers and self-employed professionals with AMI is, in turn, attributed to
a very marked increase in the risk for sudden death.
PMID- 10670554
TI - Associations of light, moderate, and vigorous intensity physical activity with
longevity. The Harvard Alumni Health Study.
AB - Physical activity is associated with better health; however, the optimal
intensity of activity remains unclear. A total of 13,485 men (mean age, 57.5
years) from the Harvard Alumni Health Study reported their walking, stair
climbing, and sports/recreation in 1977. Between 1977 and 1992, 2,539 died. After
adjusting for the different activity components, distance walked and storeys
climbed independently predicted longevity (p, trend = 0.004 and <0.001,
respectively). Light activities (<4 multiples of resting metabolic rate (METs))
were not associated with reduced mortality rates, moderate activities (4-<6 METs)
appeared somewhat beneficial, and vigorous activities (> or =6 METs) clearly
predicted lower mortality rates (p, trend = 0.72, 0.07, and <0.001,
respectively). These data provide some support for current recommendations that
emphasize moderate intensity activity; they also clearly indicate a benefit of
vigorous activity.
PMID- 10670555
TI - Deaths attributable to childbearing in Matlab, Bangladesh: indirect causes of
maternal mortality questioned.
AB - Little is known about the nature of diseases aggravated by pregnancy or the
magnitude of mortality from causes indirectly related to pregnancy. This study
aims at clarifying the contribution of indirect causes to maternal mortality by
analyzing the problem from an epidemiologic perspective, using population-based
data from Matlab, Bangladesh, for the period 1976-1993. The time spent during
pregnancy and the puerperium was considered a transitory exposure period in
women's lives, and death rates were calculated for women aged 15-44 years, while
exposed and while not exposed. During or shortly after pregnancy, death rates
from all causes are more than twice as high as outside this period. Once direct
obstetric causes and injuries are excluded, the death rates among women while
exposed are substantially lower than the death rates among women while not
exposed. Several interpretations of this finding are discussed, particularly the
role of selective factors ("healthy pregnant woman effect"?). This study
highlights the complexity of the concept of indirect causes of maternal mortality
and clearly illustrates the inherent difficulties in estimating the excess risk
of death attached to pregnancy and the puerperium.
PMID- 10670556
TI - US Department of Veterans Affairs medical care system as a resource to
epidemiologists.
AB - Epidemiologists have utilized several health care systems with large numbers of
enrollees and centralized databases to achieve their research aims. Although
containing many of the features that have made certain health care systems
valuable to the conduct of epidemiologic research, the US Department of Veterans
Affairs (VA) medical care system has not been well utilized by epidemiologists.
This article will describe existing and planned features of this health care
system that should be of interest to epidemiologists, including centralized
databases that capture hospital discharge and outpatient clinic diagnostic data,
a planned enrollment file that would contain all persons eligible for VA medical
care, and the size and national dispersion of VA medical care facilities. Also,
VA leadership has demonstrated an interest in the promotion of epidemiologic
research by initiating several new programs, including the creation of three
Epidemiologic Research and Information Centers (ERICs) to foster VA epidemiologic
research, and announcing a program to support investigator-initiated
epidemiologic research projects with VA funding. Epidemiologists with interests
in medical problems that afflict veterans should consider partnerships with VA
investigators to achieve their research aims.
PMID- 10670557
TI - Do health interview surveys yield reliable data on chronic illness among older
respondents?
AB - Previous research evaluating quality of health interview survey data has
generally relied upon comparisons of household interview data with medical
records or other external sources of information. However, "gold standards" are
not always satisfactory or available. This paper illustrates an alternative
approach to the evaluation of data quality-examination of the reliability of
reports of chronic conditions in longitudinal surveys. The data come from
national samples of older Americans (First National Health and Nutrition
Examination Survey Epidemiologic Followup Study, 1971-1975, 1982-1984, 1986) and
older Taiwanese (Survey of Health and Living Status of the Elderly, 1989, 1993,
1996). The results show that, among respondents who reported a chronic condition
at a given interview, the likelihood that the condition was acknowledged at the
subsequent interview was higher for hypertension and diabetes than for arthritis
and stroke. Low levels of consistency for stroke appear to result partly from the
poor wording of questions. In Taiwan, younger, more educated persons and those
experiencing severe conditions were somewhat more likely to acknowledge the
condition at follow-up compared with their respective counterparts. Women and
persons of high cognitive status in the United States and respondents in both
countries who used a proxy to report the occurrence of a stroke were also more
likely to acknowledge conditions at follow-up.
PMID- 10670558
TI - Genetic distances for the study of infectious disease epidemiology.
AB - Molecular epidemiologic studies of infectious pathogens 1) generate genetic
patterns from a collection of microorganisms, 2) compare the degree of similarity
among these patterns, and 3) infer from these similarities infectious disease
transmission patterns. The authors propose a quantitative approach using genetic
distances to study the degree of similarity between patterns. Benefits of such
genetic distance calculations are illustrated by an analysis of standard DNA
fingerprints of Mycobacterium tuberculosis in San Francisco collected during the
period 1991-1997. Graphical representation of genetic distances can assist in
determining if the disappearance of a specific pattern in a community is due to
interruption of transmission or ongoing evolution of the microorganism's
fingerprint. Genetic distances can also compensate for varying information
content derived by DNA fingerprints of contrasting pattern complexity. To study
demographic and clinical correlates of transmission, the authors calculated the
smallest genetic distance from each patient sample to all other samples. With
correlation of genetic distances and nearest genetic distances with previously
understood notions of the epidemiology of M. tuberculosis in San Francisco,
factors influencing transmission are investigated.
PMID- 10670559
TI - Re: "Biased tests of association: comparisons of allele frequencies when
departing from Hardy-Weinberg proportions".
PMID- 10670560
TI - Reducing the use of antimicrobial agents in animals and man.
PMID- 10670561
TI - Expression of putative virulence factors by clinical isolates of Klebsiella
planticola.
AB - A total of 92 clinical isolates of Klebsiella planticola from man was examined
with respect to the production of haemagglutinins and siderophores, serum
resistance and distribution of capsular types. For comparison, a group of 207
clinical isolates of K. pneumoniae was also studied. The percentages of K.
planticola strains able to express mannose-sensitive haemagglutination,
indicating type 1 fimbriae (83%) and mannose-resistant and Klebsiella-like
agglutination, indicating type 3 fimbriae (69%), as well as to produce the
siderophores enterobactin (100%) and aerobactin (2.2%) were almost identical to
those of the K. pneumoniae strains. Similarly, the proportion of serum-resistant
strains (30%) was comparable to that of K. pneumoniae (25%). The capsule types
most often detected in K. planticola were K14 (13%), K2 (9%) and K70 (9%). The
incidence of K2, which is the predominant capsular type in K. pneumoniae, was
similar in both species. These findings show that K. planticola, which is being
detected with increasing frequency in clinical specimens from man, has the
ability to express similar putative virulence factors to K. pneumoniae,
suggesting that they may have similar pathogenicity.
PMID- 10670562
TI - Production of an enterotoxin by a gastro-enteritis-associated Aeromonas strain.
AB - The potential of motile Aeromonas species to cause human gastrointestinal
infections has been recognised recently. Considerable worldwide epidemiological,
microbiological and clinical investigations have shown that some strains of the
different motile aeromonads are of increasing enteropathogenic significance,
especially in children, the elderly and in immunocompromised individuals. Some of
the diarrhoeal symptoms of Aeromonas-associated gastro-enteritis have been
attributed to enterotoxins. In this study, 15 Aeromonas isolates from clinical
and non-clinical sources, representing the three motile aeromonads commonly
associated with gastro-enteritis (A. caviae, A. hydrophila and A. veronii biovar
sobria), were tested for their ability to cause fluid accumulation in infant mice
by the suckling mouse technique. Eight isolates were found to produce
enterotoxin. Of these, an A. veronii biovar sobria strain (AS15), isolated from
lamb kidney, was found to produce the highest enterotoxin score. An enterotoxin
of c. 40 kDa produced by A. veronii biovar sobria AS15 was purified by Sephacryl
S-100 gel filtration and high-performance liquid chromatography. This enterotoxin
caused marked fluid accumulation in infant mice by the suckling mouse technique.
The purified enterotoxin cross-reacted with cholera toxin antibodies and was
readily inactivated by heating at 56 degrees C for 10 min. The production of a
'cholera-like' enterotoxin by Aeromonas isolates from samples of animal origin
suggests that these organisms could be of public health significance in food
products.
PMID- 10670563
TI - Biological activities of lipopolysaccharides of Proteus spp. and their
interactions with polymyxin B and an 18-kDa cationic antimicrobial protein
(CAP18)-derived peptide.
AB - The saccharide constituents of lipopolysaccharides (LPS) of Proteus spp. vary
with the strain and contain unique components about which little is known. The
biological activities of LPS and lipid A from S- and R-forms of 10 Proteus
strains were examined. LPS from all S-form Proteus strains was lethal to D-(+)
galactosamine (GalN)-loaded, LPS-responsive, C3H/HeN mice, but not to LPS-hypo
responsive C3H/HeJ mice. P. vulgaris 025 LPS evoked strong anaphylactoid
reactions in N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP)-primed C3H/HeJ mice.
LPS from S- and R-form Proteus strains induced production of nitric oxide (NO)
and tumour necrosis factor (TNF) by macrophages isolated from C3H/HeN but not
C3H/HeJ mice. Lipid A from Proteus strains also induced NO and TNF production,
although lipid A was less potent than LPS. The effects of LPS were mainly
dependent on CD14; LPS-induced NO and TNF production in CD14+ J774.1 cells was
significantly greater than in CD14-J7.DEF.3 cells. All LPS from Proteus strains,
and especially from P. vulgaris 025, exhibited higher anti-complementary activity
than LPS from Escherichia coli or Pseudomonas aeruginosa. Polymyxin B inactivated
proteus LPS in a dose-dependent manner, but these LPS preparations were more
resistant to polymyxin B than E. coli LPS. CAP18(109-135), a granulocyte-derived
peptide, inhibited proteus LPS endotoxicity only when the LPS:CAP18(109-135)
ratio was appropriate, which suggests that CAP18(109-135) acts through a
different mechanism than polymyxin B. The results indicate that LPS from Proteus
spp. are potently endotoxic, but that the toxicity is different from that of LPS
from E. coli or Salmonella spp. and even varies among different Proteus strains.
The variation in biological activities among proteus LPS may be due to unique
components within the respective LPS.
PMID- 10670564
TI - Ultrastructural study of Mycobacterium avium infection of HT-29 human intestinal
epithelial cells.
AB - Mycobacterium avium is a common pathogen in AIDS patients and, in a large
percentage of those patients, M. avium infection appears to be acquired via the
gastrointestinal tract. M. avium is able to bind to and enter human and murine
intestinal epithelial cells in vitro and in vivo. The invasion by and
intracellular fate of M. avium in the HT-29 intestinal epithelial cell line was
examined in an ultrastructural study. Bacterial contact with polarised cells was
observed 10-15 min after monolayer infection and in polarised monolayers this
always occurred in areas lacking microvilli. Contact with HT-29 cells did not
appear to take place in a preferential area on the bacterial cell. Following
invasion, M. avium was encountered within vacuoles containing either single or
multiple bacteria; the latter evolved to contain only an individual bacterium.
Vacuoles containing more than one bacterium were seen early in the infection and
eventually underwent segmentation, with each bacterium occupying a vacuole. No
bacteria were observed outside vacuoles up to 5 days after infection.
PMID- 10670565
TI - Development and evaluation of a solid-phase enzyme immunoassay based on Andes
hantavirus recombinant nucleoprotein.
AB - Hantavirus pulmonary syndrome (HPS) with high mortality rate has been reported in
five countries in South America. Rapid accurate methods are important both for
monitoring acute infections and for epidemiological studies. The Andes virus
nucleoprotein amino acid sequence has a high identity percentage compared with
other sequences of this region and has been chosen for the development of
diagnostic reagents. Andes nucleoprotein expressed in Escherichia coli was
applied as antigen in IgG, IgA and mu-capture IgM enzyme-linked inmunosorbent
assays (ELISAs). An evaluation of this reagent was conducted to establish its
usefulness for differential diagnosis of HPS and seroprevalence studies. Samples
from 135 reverse transcription (RT)-PCR-confirmed HPS cases, 77 individuals with
other respiratory infections and 957 healthy inhabitants from endemic and non
endemic areas were analysed. The hantavirus-infected patients had an early and
strong IgM, IgG and IgA serum antibody response, in most of the cases as early as
1, 7 and 1 days following onset of symptoms, respectively. IgM and IgG detection
showed a specificity and sensitivity of 100%. Andes-specific IgM antibodies were
found in all patients in the first available sample, which remained detectable
for at least 43 days. Specific IgA antibodies were also detected in saliva of
patients with acute HPS. The short duration of the disease and the risk for
contacts due to person-to-person transmission of Andes virus necessitate the use
of highly sensitive tests which might lead to earlier detection of infected
people and improve the treatment and management of patients with HPS.
PMID- 10670567
TI - Identification and partial characterisation of a new protective antigen of
Brucella abortus.
AB - Two novel Brucella abortus proteins were isolated from B. abortus strain RB51 and
their immunological properties were determined. These proteins precipitated in
the 40-60% saturated concentration range of ammonium sulphate and had a molecular
mass of 32.2 kDa and 22.9 kDa, respectively. Both were able to induce a strong in
vitro blast transformation in lymphoid cells obtained from mice previously
sensitised with a crude brucella protein extract. The protection studies showed
that the 22.9-kDa protein used as a protective immunogen was as effective as the
live B. abortus RB51 vaccine but the 32.2-kDa protein had a poor protective
effect under similar conditions. The amino-terminal sequence of the 22.9-kDa and
32.2-kDa proteins was determined and analysed in a database. The lack of homology
with other known B. abortus proteins indicated that both proteins were novel
antigens.
PMID- 10670566
TI - A nasal whole-cell pertussis vaccine induces specific systemic and cross-reactive
mucosal antibody responses in human volunteers.
AB - A whole-cell pertussis vaccine, each dose consisting of 250 microg of protein,
was given intranasally four times at weekly intervals to six adult volunteers.
All vaccinees responded with increases in nasal fluid IgA antibodies to
Bordetella pertussis whole-cell antigen. Three vaccinees with high nasal antibody
responses also developed increased serum IgA and IgG antibodies to this antigen.
Salivary antibody responses to the whole-cell antigen, as well as antibodies in
serum and secretions to pertussis toxin (PT) and filamentous haemagglutinin (FHA)
were negligible, except for a moderate increase in nasal fluid antibodies to FHA.
Unexpectedly, the same vaccinees developed significant rises in nasal and
salivary IgA antibodies to meningococcal outer-membrane antigens, whereas
corresponding serum IgA and IgG antibodies were unchanged. Thus it appears that
mucosal immunisation may induce secretory antibodies with broader specificities
than can be found in serum.
PMID- 10670568
TI - Role of interleukin-6 in determining the course of murine Tyzzer's disease.
AB - Clostridium piliforme is an obligately intracellular bacterium that causes
enterohepatic disease in many domestic and laboratory animal species.
Susceptibility to infection is known to vary with the host immune status, species
and strain, but little is known about specific immune mechanisms that regulate
this disease. Subclinical infection was induced in weanling C. piliforme
susceptible DBA/2 or resistant C57BL/6 mice with either a toxic or a non-toxic C.
piliforme isolate. Hepatic lesions and bacteria were evident in both mouse
strains for 14 days after inoculation with the toxigenic bacterial isolate, but
were never demonstrated following inoculation with the non-toxigenic isolate. All
mice demonstrated increased interleukin-6 (IL-6) levels that were largely
independent of host strain susceptibility to infection or virulence of the
bacterial isolate. The severity of C. piliforme-induced hepatic lesions was
increased by polyclonal anti-IL-6 treatment in both resistant (DBA/2) and
susceptible (C57BL/6) mouse strains. These data indicate that IL-6 is important
in mediating the course of murine C. piliforme infections but is not involved in
determining host susceptibility to acute infection, nor is it influenced by the
virulence of the C. piliforme isolate.
PMID- 10670569
TI - Clonal groups of enteropathogenic Escherichia coli isolated in case-control
studies of diarrhoea in Bangladesh.
AB - Recent case-control studies in Bangladesh showed a high prevalence of
enteropathogenic Escherichia coli (EPEC) strains (identified by DNA probes for
virulence genes) associated with childhood diarrhoea. However, the clonal status
of these strains is not known. A total of 94 EPEC isolates from 80 children with
diarrhoea and 14 healthy matched controls isolated during 1991-1992 and 1993-1994
was characterised by serogrouping, enterobacterial repetitive intergenic
consensus sequence PCR, and by a biochemical fingerprinting method (the phene
plate or PhP system). Twelve O serogroups were found with O114 (n = 19) and O127
(n = 23) being the dominant serogroups. Most strains of O114 belonged to the same
PhP/PCR types. Strains of O127 contained 16 that produced cytolethal distending
toxin (CDT) and seven that did not; both were found among patients as well as
controls. Results of PCR and PhP typing showed that CDT-positive strains belonged
to the same clonal group and were related to one of the two PhP/PCR types of CDT
negative O127 strains. Thirty-one EPEC strains were O non-typable and 21 strains
belonged to other less prevalent serogroups. These strains belonged to diverse
PhP/PCR types and did not show any similarity to the strains of two major
serogroups, O114 and O127. The results suggest that two clonal groups of EPEC
strains are predominantly associated with childhood diarrhoea in Bangladesh.
PMID- 10670570
TI - Spread of the Brazilian epidemic clone of a multiresistant MRSA in two cities in
Argentina.
AB - Methicillin-resistant Staphylococcus aureus (MRSA) is recognised as an important
cause of nosocomial infection. The spread of some MRSA epidemic clones is well
documented. In Brazil, and more recently in Portugal, a considerable number of
hospital infections has been caused by a unique multiresistant MRSA clone
designated as the Brazilian epidemic clone. This paper describes the spread of
this clone in hospitals in two cities in Argentina.
PMID- 10670571
TI - Distribution and expression of bca, the gene encoding the c alpha protein, by
Streptococcus agalactiae.
AB - A total of 52 clinical isolates of group B streptococci (GBS) was tested for
expression of the c protein c(alpha) by a fluorescent antibody test (FAT) and by
PCR amplification of a 202-bp stretch within the repeat unit of the bca gene
encoding the c(alpha) protein. The strains were categorised as follows: c(alpha)
FAT positive and PCR positive with amplification products of multiple sizes
(category A, n = 12); FAT negative and with PCR products of multiple sizes
(category B, n = 11); FAT negative and with a single PCR product of c. 200 bp
(category C, n = 5); negative in both tests (category D, n = 24). A single
amplification product of minimum size and additional products of larger sizes
corresponded to one and more bca repeats, respectively. Five of the 11 category B
strains showed expression of low Mr c(alpha) in whole cell-based Western
blotting. The results showed that a proportion of the GBS isolates harboured bca
gene elements that either were not expressed or they expressed c(alpha) molecular
variants which could not be detected by the whole cell-based FAT. This
genotype/phenotype discrepancy should be considered in relation to GBS typing,
including the selection of antibody reagents and the technical approach to
c(alpha) protein detection.
PMID- 10670572
TI - Phenotypic characterisation of Candida albicans isolated from chronic
hyperplastic candidosis.
AB - The phenotypes of 35 Candida albicans isolates from 19 patients with chronic
hyperplastic candidosis (CHC) and 35 isolates from 30 patients with non-CHC
infections were compared. Typing was based on carbohydrate assimilation, chemical
sensitivity and serology. Eight carbohydrate assimilation profiles were evident
with the API-20C system and a single profile predominated for isolates from CHC
(17 of 19 patients; 89%) and non-CHC (18 of 30 patients; 63%). Chemical
sensitivity tests revealed four profiles with no significant difference between
CHC and non-CHC isolates. Serotype A predominated for isolates from both CHC (15
of 19 patients; 79%) and non-CHC (25 of 30 patients; 83%) infections. Boric acid
resistance was more prevalent in CHC isolates, although a significant difference
was not apparent. In summary, there was no overall difference in the phenotypes
of isolates from CHC and non-CHC patients, and clonal restriction of CHC isolates
was not demonstrated.
PMID- 10670573
TI - c-Kit and c-kit mutations in mastocytosis and other hematological diseases.
AB - Mast cells (MC) are tissue elements derived from hematopoietic stem cells. Their
differentiation and proliferation processes are under the influence of cytokines,
including one of utmost importance known as stem cell factor (SCF). SCF receptor
is encoded by the protooncogene c-kit, belongs to the type III receptor tyrosine
kinase subfamily, and is also expressed on other hematopoietic or non
hematopoietic cells. Ligation of c-kit receptor by SCF induces its dimerization,
followed by induction of multiple intracellular signaling pathways leading to
cell proliferation and activation. Mastocytosis, a relatively rare group of
diseases characterized by accumulation of MC in various tissues, are found
isolated or sometimes associated with other hematological malignancies in humans.
Although the initial events leading to mastocytosis are not yet unraveled,
alterations of the c-kit gene have been described. Particularly interesting are
acquired mutations resulting in a constitutively activated receptor, possibly
involved in the increased numbers of MC in tissues. For this reason, future
strategies might be envisaged to target specifically the mutated c-kit and/or its
intracellular signaling.
PMID- 10670574
TI - Extracellular matrix moieties, cytokines, and enzymes: dynamic effects on immune
cell behavior and inflammation.
AB - Tissue injury caused by infection or physical damage evokes inflammatory
reactions and events that are necessary for regaining homeostasis. Central to
these events is the translocation of leukocytes, including monocytes,
neutrophils, and T lymphocytes, from the vascular system, through endothelium,
and into the extracellular matrix (ECM) surrounding the injured tissue. This
transition from the vasculature into the site of inflammation elicits remarkable
changes in leukocyte behavior as cells adhere to and migrate across ECM before
carrying out their effector functions. Growing evidence suggests that, through
its interactions with cytokines and degradative enzymes, the ECM microenvironment
has a specialized role in providing intrinsic signals for coordinating leukocyte
actions. Recent advances also reveal that enzymatic modifications to ECM moieties
and cytokines induce distinctive cellular responses, and are likely part of the
mechanism regulating the perpetuation or arrest of inflammation. This article
reviews the findings that have elucidated the dynamic relationships among these
factors and how they communicate with immune cells during inflammation.
PMID- 10670575
TI - Reduced brain edema after traumatic brain injury in mice deficient in P-selectin
and intercellular adhesion molecule-1.
AB - Platelet (P-) selectin and intercellular adhesion molecule-1 (ICAM-1) mediate
accumulation of neutrophils in brain. However, the mechanisms regulating
neutrophil accumulation and damage after traumatic brain injury (TBI) are poorly
defined. We hypothesized that mice deficient in both P-selectin and ICAM-1 (-/-)
would have decreased brain neutrophil accumulation and edema, and improved
functional and histopathological outcome after TBI compared with wild-type (+/+).
In Protocol I, neutrophils and brain water content were quantified at 24 h after
TBI. No difference in brain neutrophil accumulation was observed between groups;
however, brain edema was decreased in dual P-selectin and ICAM-1 -/- (P < 0.05
vs. +/+ mice). In Protocol II, after TBI, tests of motor and memory function and
histopathology were assessed over 21 days. No difference in motor or memory
function or histopathological damage was observed between +/+ and -/- mice. A
role for adhesion molecules in the pathogenesis of brain edema independent of
leukocyte accumulation in brain is suggested.
PMID- 10670576
TI - Homing and adhesion molecules in autoimmune gastritis.
AB - The pathogenesis of autoimmune gastritis is the result of lymphocyte infiltration
of the gastric mucosa, however, the events leading to the selective extravasation
of autoreactive lymphocytes are unclear. Here we have examined the expression of
adhesion molecules in the gastric mucosa of BALB/c mice with neonatal thymectomy
induced gastritis. The overall area of vascular endothelium was not significantly
different between gastritic and non-gastritic mice. However, a significant
increase in the area of mucosal endothelium expressing MAdCAM-1 in gastritic mice
was observed. Treatment of neonatally thymectomized BALB/c mice with a MAdCAM-1
specific monoclonal antibody (MECA 367) reduced the incidence of autoimmune
gastritis from 80 to 26%. Treatment with a monoclonal antibody (R1-2) directed to
the MAdCAM-1 ligand, alpha4beta7, also resulted in a reduction in the incidence
of gastritis to 40%. These findings identify the alpha4beta7/MAdCAM-I interaction
as a pivotal event in the initiation of autoimmune gastritis.
PMID- 10670577
TI - In vivo administration of GM-CSF promotes the clearance of apoptotic cells:
effects on monocytes and polymorphonuclear leukocytes.
AB - The clearance of apoptotic cells is crucial to avoid chronic inflammation and
autoimmunity. Little is known about the factors that regulate it in vivo. We show
that granulocyte-macrophage colony-stimulating factor (GM-CSF) administration to
carcinoma patients confers to their leukocytes a significantly higher ability to
phagocytose apoptotic cells than before (P < 0.005). GM-CSF increased the
concentration of monocytes and polymorphonuclear leukocytes in the peripheral
blood and activated circulating polymorphonuclear leukocytes. Both effects abated
early after treatment, whereas phagocytosis of apoptotic cells was still
significantly higher after 18 days compared with basal values (P < 0.005 and P <
0.025 for monocytes and polymorphonuclear leukocytes, respectively). On in vitro
phagocytosis of apoptotic cells monocytes, but not polymorphonuclear leukocytes,
up-regulated MHC class II membrane expression. These findings are consistent with
the possibility that GM-CSF endows both scavenger and antigen-presenting
leukocytes with the ability to internalize apoptotic tumor cells.
PMID- 10670578
TI - Serglycin secreted by leukocytes is efficiently eliminated from the circulation
by sinusoidal scavenger endothelial cells in the liver.
AB - This study was undertaken to determine the fate of the circulating chondroitin
sulfate proteoglycan serglycin. The human monocytic cell line THP-1 was cultured
under serum-free conditions in the presence of [35S]sulfate. The conditioned
medium was harvested and 35S-macromolecules were purified by Q-Sepharose anion
exchange chromatography and Superose 6 gel chromatography. After labeling with
125I, the purified material was treated with chondroitinase ABC and subjected to
sodium dodecyl sulfate polyacrylamide gel electrophoresis. A major band with mr
of approximately 14 kDa appeared, consistent with the core protein of serglycin.
The identity of the proteoglycan was confirmed by amino-terminal amino acid
sequencing. Purified serglycin, labeled either with [35S]sulfate or 125I and
fluorescein isothiocyanate, was injected intravenously into rats. The blood
content of radiolabeled serglycin fell by 50% from 1 to 2.4 min after injection,
indicating an initial t1/2 of 1.4 min or shorter. Approximately 90% of the
recovered radioactivity was localized in the liver, 5% in the blood, and 5%
altogether in urine, kidneys, and spleen about 30 min after injection. Isolation
of liver cells at the same time point showed that 70% of the radioactivity was
taken up by the sinusoidal scavenger endothelial cells, and 23 and 7% by the
hepatocytes and Kupffer cells, respectively. When excess amounts of unlabeled
hyaluronan was coinjected with radiolabeled serglycin, the elimination of
serglycin was significantly inhibited, indicating that the hyaluronan receptor on
the sinusoidal scavenger endothelial cells is responsible for the elimination of
serglycin.
PMID- 10670579
TI - Role of endothelins on lymphocyte accumulation in allergic pleurisy.
AB - Endothelins participate in different aspects of inflammatory reactions, including
edema formation and eosinophil accumulation in allergic reaction. In this study,
we demonstrated a role for endogenous endothelins in eosinophil and T lymphocyte
recruitment and cytokine secretion in a murine model of allergic inflammation.
Intrathoracic stimulation with endothelin-1 triggered a neutrophil accumulation
at 4 h, concomitant with an increase of CD4+ and CD8+ T lymphocyte populations.
Antigen challenge in sensitized animals leads to an increase in eosinophil and
mononuclear cell numbers at 24 h. Treatment with ETA receptor antagonist (BQ123)
inhibited antigen-induced eosinophil and mononuclear cell migration, whereas the
selective ETB receptor antagonist BQ-788 was ineffective. The latter effect of BQ
123 was due to inhibition of CD4+ and CD8+ T lymphocytes. Treatment with BQ-123
also inhibited interleukin-5 levels in the exudate and plasma as well as
intracellular staining of interleukin-4, interleukin-5, and interferon-gamma in
CD4+ lymphocytes. These findings suggest that endogenous endothelins contribute
to allergic inflammation by modulating lymphocyte recruitment and cytokine
production.
PMID- 10670580
TI - CD11b/CD18-coated microspheres attach to E-selectin under flow.
AB - Neutrophils can attach to E-selectin under flow. Proposed ligands for E-selectin
carry SLe(x)-type glycans. The leukocyte beta2 integrins are glycosylated with
SLe(x). Thus, we speculated that beta2 integrins could support attachment to E
selectin. To test this hypothesis, we coated 10-microm-diameter microspheres with
purified CD11b/CD18 (alphaMbeta2) and investigated the adhesion of the resulting
alphaMbeta2 microspheres to E-selectin. Under in vitro flow conditions, the
alphaMbeta2 microspheres attached to Chinese hamster ovary cells expressing E
selectin (CHO-E) and 4-h interleukin-1beta-activated human umbilical vein
endothelial cells (HUVEC). At a shear stress of 1.8 dynes/cm2, the attachment
events were eliminated by pretreatment of the cellular monolayers with a mAb to E
selectin. alphaMbeta2 microspheres did not attach to untransfected CHO cells or
unactivated HUVEC at 1.8 dynes/cm2. Taken together, the results strongly suggest
that the CD11b/CD18-E-selectin bond has sufficient biophysical properties to
mediate attachment of neutrophil-sized particles to E-selectin under flow.
PMID- 10670581
TI - Langerhans cells acquire a CD8+ dendritic cell phenotype on maturation by CD40
ligation.
AB - Dendritic cell (DC) reconstitution experiments and phenotypic analysis of DC
subpopulations have allowed the definition in the mouse of two main DC
categories: CD8+ lymphoid DCs and CD8- myeloid DCs. With regard to Langerhans
cells (LCs), which represent immature DCs differentiating into mature DCs on
migration to the lymph nodes after an antigenic stimulation, although classically
considered as myeloid DCs, there is no experimental evidence of their origin. It
has been recently shown that mouse LCs, negative for CD8 and LFA-1, undergo
CD8/LFA-1 up-regulation on migration, suggesting that LCs belong to the CD8+
lymphoid DC lineage. To further reinforce this hypothesis, we have analyzed the
modulation of CD8 expression by LCs on culture with molecules known to induce LC
maturation. Our results show that LC acquired a CD8+ lymphoid phenotype on CD40
ligation.
PMID- 10670582
TI - P47(phox)-deficient NADPH oxidase defect in neutrophils of diabetic mouse
strains, C57BL/6J-m db/db and db/+.
AB - Deficiencies in neutrophil NADPH oxidase proteins have been demonstrated in
humans with chronic granulomatous disease. However, no spontaneous mutation in
murine NADPH oxidase has been reported. In this study we report that neutrophils
from the diabetic mouse strains, C57BL/6J-m heterozygous lean (lepr(db/+)) and
homozygous obese (lepr(db/db)) mice produced no superoxide on stimulation. An
absence of intact p47(phox) but not other oxidase proteins was observed in both
mouse strains through the use of immunoblotting. Molecular analysis by reverse
transcriptase-polymerase chain reaction identified three abnormal p47phox mRNA
transcripts. Sequencing of genomic DNA of p47(phox) revealed a point mutation at
the -2 position of exon 8, which is consistent with aberrant splicing of the
p47(phox) transcript. These results indicate that the C57BL/6J-m db/db and db/+
mice are the first spontaneously derived murine model of NADPH oxidase deficiency
involving a p47(phox) mutation.
PMID- 10670583
TI - Differential role of tyrosine phosphorylation in adhesion-induced transcription,
mRNA stability, and cytoskeletal organization in human monocytes.
AB - Monocyte adhesion resulted in rapid tyrosine phosphorylation and subsequent
cytokine mRNA induction. The objective of this study was to determine the role of
specific tyrosine phosphorylation events, particularly those involving members of
the MAP kinase family, in regulating adhesion-induced cytokine expression. Using
nuclear run-on analyses, we demonstrated that on adhesion, monocytes rapidly
transcriptionally activated numerous cytokine mRNAs, coincident with the
activation of the transcription factors NF-KB and AP-1. Both an inhibitor of
tyrosine phosphorylation, genistein, and the cytoplasmic tyrosine phosphatase
PTP1B, were unable to prevent adhesion-mediated transcriptional activation.
However, both blocked adhesion-induced ERK and JNK but not p38 kinase activation
and at the same time decreased the stability of interleukin-1beta (IL-1beta) and
IL-8 transcripts. In addition, whereas adhesive events occurred in the presence
of genistein and PTP1B, monocyte spreading was markedly inhibited. Our results
suggest that the majority of protein phosphorylation events are associated with
adhesion-induced cytokine expression through transcript stabilization and
cytoskeletal organization. A minority of protein phosphorylation events, not
sensitive to genistein or PTP1B exposure, may be instrumental in regulating
transcription. Thus the spectrum of protein tyrosine kinases required for
transcription appear distinct from those involved in maintaining the stability of
some cytokine mRNAs and the integrity of the cytoskeleton to which mRNA destined
for translation must be associated.
PMID- 10670584
TI - Particulate adjuvants can induce macrophage survival, DNA synthesis, and a
synergistic proliferative response to GM-CSF and CSF-1.
AB - The mode of action of immunological adjuvants is not yet completely understood.
Many are particulate. Certain antigen-presenting (dendritic) cell populations
belong to the monocyte/macrophage lineage and, like other members of the lineage,
in some tissues appear to be short-lived. We report that many poorly degradable,
particulate adjuvants, for example, aluminum hydroxide, oil-in-water emulsions,
calcium phosphate, and silica, enhance murine bone marrow-derived macrophage
survival; induction of DNA synthesis was even observed. No evidence could be
found for a requirement for endogenous granulocyte-macrophage colony-stimulating
factor (GM-CSF) or macrophage-CSF (M-CSF or CSF-1). Synergy for the proliferative
effects was noted in the presence of added GM-CSF or CSF-1. It is suggested from
these in vitro findings that one function of certain particulate adjuvants may be
to increase by enhanced survival or even proliferation the number of cells
available for subsequent antigen presentation and cytokine production.
PMID- 10670585
TI - Antimicrobial effects of alpha-MSH peptides.
AB - The presence of the ancient anti-inflammatory peptide alpha-melanocyte
stimulating hormone [alpha-MSH (1-13), SYSMEHFRWGKPV] in barrier organs such as
gut and skin suggests a role in the nonspecific (innate) host defense. alpha-MSH
and and its carboxy-terminal tripeptide (11-13, KPV) were determined to have
antimicrobial influences against two major and representative pathogens:
Staphylococcus aureus and Candida albicans. alpha-MSH peptides significantly
inhibited S. aureus colony formation and reversed the enhancing effect of
urokinase on colony formation. Antimicrobial effects occurred over a broad range
of concentrations including the physiological (picomolar) range. Small
concentrations of alpha-MSH peptides likewise reduced viability and germ tube
formation of the yeast C. albicans. Antimicrobial influences of alpha-MSH
peptides could be mediated by their capacity to increase cellular cAMP. Indeed,
this messenger was significantly augmented in peptide-treated yeast and the
potent adenylyl cyclase inhibitor dideoxyadenosine (ddAdo) partly reversed the
killing activity of alpha-MSH peptides. Reduced killing of pathogens is a
detrimental consequence of therapy with anti-inflammatory drugs. Because alpha
MSH has potent anti-inflammatory effects we determined influences of alpha-MSH on
C. albicans and S. aureus killing by human neutrophils. alpha-MSH peptides did
not reduce killing but rather enhanced it, likely as a consequence of the direct
antimicrobial activity. alpha-MSH peptides that combine antipyretic, anti
inflammatory, and antimicrobial effects could be useful in treatment of disorders
in which infection and inflammation coexist.
PMID- 10670586
TI - Expression of serum- and glucocorticoid-regulated kinase (sgk) mRNA is up
regulated by GM-CSF and other proinflammatory mediators in human granulocytes.
AB - Stimulation of human peripheral blood granulocytes with the proinflammatory
cytokine, granulocyte-macrophage colony-stimulating factor (GM-CSF), increases
incorporation of [3H]uridine into RNA. We investigated the nature of the RNA
synthesized under these conditions. Using transcription inhibitors, gel
electrophoresis, and high-salt precipitation, it was concluded that as much as
90% of this radiolabeled RNA represents polymerase II transcripts. Differential
display reverse transcription-polymerase chain reaction was used to identify and
clone GM-CSF-responsive mRNAs. Serum- and glucocorticoid-regulated kinase (sgk)
mRNA was identified that could be up-regulated 10- to 20-fold by > or =0. 1 ng/mL
recombinant human GM-CSF. The 2.6-kb sgk mRNA was induced rapidly (within 30 min)
by GM-CSF and remained at high levels for at least 12 h. Up-regulation was
blocked completely by the transcription inhibitor, actinomycin D, but not by the
translation inhibitor, cycloheximide, nor by the tyrosine kinase inhibitor,
genistein. Up-regulation did not appear to be caused by enhanced mRNA stability.
Other inflammatory mediators could also increase sgk mRNA levels (GM-CSF > >
lipopolysaccharide > fMLP = tumor necrosis factor alpha). The function of sgk in
granulocytes remains unknown.
PMID- 10670587
TI - Rottlerin, a PKC isozyme-selective inhibitor, affects signaling events and
cytokine production in human monocytes.
AB - The implication of select protein kinase C (PKC) isoenzymes in cytokine
production by human monocytes was investigated using an isozyme-selective
inhibitor of PKC, rottlerin. We found that lipopolysaccharide (LPS) triggers
cytosol-to-membrane translocation of PKCalpha and delta isoenzymes, whereas
phorbol ester (PMA) induces translocation of several PKC isoforms. Moreover, we
show that in LPS- and PMA-stimulated monocytes rottlerin affects several cellular
responses. (1) At low (15 microM) concentration it blocks translocation of
PKCdelta, diminishes DNA binding activity of AP-1 transcription factor, and
attenuates cytokine production [tumor necrosis factor alpha (TNF-alpha) >
interleukin-1beta (IL-1beta)]. (2) At high (50 microM) concentration it prevents
translocation of PKCalpha, and subsequently inhibits ERK1/ERK2 phosphorylation,
DNA binding activities of AP-1 and nuclear factor-KB transcription factors, and
the production of both tested cytokines. Thus, we propose that cytosol-to
membrane translocation of PKCalpha and PKdelta isoenzymes may represent early
steps in the signaling cascades that lead to TNF-alpha and IL-1beta production in
human monocytes.
PMID- 10670589
TI - Facing the problems of faculty recruitment and retention.
PMID- 10670588
TI - AP-1 activity is negatively regulated by cannabinol through inhibition of its
protein components, c-fos and c-jun.
AB - Regulation of the activator protein-1 (AP-1) complex is very intricate because it
involves phosphorylation state, protein-protein, and protein-DNA interactions. In
these studies, the regulation of AP-1 activity, with emphasis on c-fos and c-jun
regulation, was investigated using cannabinol (CBN) in primary mouse splenocytes
in vitro. Cannabinoid compounds exhibit immunosuppressive actions that are
putatively mediated through Gi-protein coupled receptors that negatively regulate
adenylate cyclase. However, recent studies suggest that cannabinoids modulate
other signaling cascades. Indeed, we demonstrate that CBN inhibited binding to AP
1-containing sites from the interleukin-2 promoter. This inhibition of binding
was, in part, due to decreased nuclear expression of c-fos and c-jun. We further
determined that the effects of CBN were due to posttranslational modifications of
these phosphoproteins and showed that CBN inhibited the activation of ERK MAP
kinases. Thus, cannabinoid-induced immunosuppression involves disruption of the
ERK signaling cascade.
PMID- 10670590
TI - Anticoagulation and minor oral surgery: should the anticoagulation regimen be
altered?
AB - PURPOSE: This study was performed to assess the extent of bleeding in
anticoagulated patients undergoing minor oral surgery procedures when compared
with patients who stop their anticoagulation regimen before surgery and patients
who have never been anticoagulated. MATERIALS AND METHODS: Patients on
anticoagulant medications undergoing dentoalveolar surgery procedures either
stopped their anticoagulation regimen 72 to 96 hours before the planned surgical
intervention or continued their regular regimen throughout the time of surgery.
Blood loss was measured by weighing sponges used in the procedures, and groups
were compared for differences in blood loss. They were also compared with an
additional control group that had never been on anticoagulant therapy. RESULTS:
There was no difference in blood loss detected among any of the experimental or
control groups. No bleeding complications occurred in any anticoagulated patient.
CONCLUSIONS: The data suggest that many patients can safely undergo routine
outpatient oral surgical procedures without alteration of their regular
therapeutic anticoagulation regimens and without additional medical intervention.
However, a larger experimental population may be needed to elucidate the
appropriateness of this approach to perioperative care.
PMID- 10670591
TI - Obesity: prevalence and considerations in oral and maxillofacial surgery.
AB - PURPOSE: This article examines the prevalence of obesity in an urban hospital
based office population and describes the associated health risks and systemic
complications. PATIENTS AND METHODS: A total of 225 randomly selected patient
charts were reviewed. The patients' height and weight were recorded, and a body
mass index (BMI) was calculated. Patients were considered to have a normal weight
with a BMI between 20 and 24.9 kg/m2, to be overweight with a BMI between 25 and
29.9 kg/m2, and to be obese with a BMI of 30 kg/m2 or greater. Comparisons
between sex, age, and race were examined. RESULTS: Eighty-five males and 140
females were included in the study. The ages ranged from 9 to 86 years, with a
mean age of 37.4+/-16.4 years. The BMIs ranged from 13.9 to 57.7 kg/m2, with a
mean BMI of 26.5+/-6.8 kg/m2. Over half (51%) of the population studied was
overweight, and 23% were obese. Forty-three percent of males were considered
overweight, and 18.8% of males were obese. Women tended to be more overweight:
55.7% of women were overweight and 25.7% were obese. The African-American females
had mean BMIs that were considered overweight in all age-groups and obese in most
age-groups, which included the less than 29-year-old and over 50-year-old groups.
Caucasian females had normal mean BMIs at all ages except for the 30- to 39-year
old and 40- to 49-year-old groups. CONCLUSION: The increasing prevalence of
overweight and obese populations has several considerations in oral and
maxillofacial surgery. The associated health risks and increased morbidity and
mortality pose a serious threat to the patient being treated in an outpatient
setting.
PMID- 10670592
TI - Cervical necrotizing fasciitis of odontogenic origin: a case report and review of
12 cases.
AB - PURPOSE: This article reviews the demographics, presentation, cause, clinical
findings, and treatment of 12 cases of cervical necrotizing fasciitis of
odontogenic origin. PATIENTS AND METHODS: A retrospective chart review of 12
cases treated between 1987 and 1997 was done. RESULTS: Most cases resulted from
an abscessed mandibular molar. The most common significant medical conditions in
the patient's history were diabetes, hypertension, obesity, and substance abuse.
All patients were treated surgically within 24 hours of admission. Hyperbaric
oxygen (HBO) was used as adjunctive treatment in all cases. The average length of
hospital stay was 31 days. All patients recovered. CONCLUSION: Early surgical
intervention and the use of HBO decreases morbidity and improves the clinical
outcome.
PMID- 10670593
TI - Nutritional status of substance abusers with mandible fractures.
AB - PURPOSE: The purposes of this study were 1) to assess the validity of patient
self-report in identifying illegal substance abuse and 2) to identify nutritional
deficiencies in substance abusers presenting for treatment of mandible fractures.
PATIENTS AND METHODS: To address the research purposes, a prospective cohort
study was conducted of patients presenting for treatment of mandible fractures. A
urine drug screen was used to determine the validity of patient self-report of
substance abuse. For purposes of assessing nutritional status, 2 categories of
substance abusers were identified: illegal and legal (alcohol). The nutritional
status was measured using various laboratory markers. RESULTS: The sample was
composed of 93 subjects. Urine drug studies were available for 32 patients. Of
the 22 patients who denied illegal drug use, 12 (55%) had a positive drug screen.
Of the 10 patients reporting a positive history of illicit drug use, 7 (70%) had
a positive urine drug screen (P = .47). A positive correlation was found between
alcohol exposure and serum aspartate aminotransferase, mean corpuscular volume,
and lactate dehydrogenase. Positive drug screens also were associated with
increased serum ferritin levels. CONCLUSIONS: The results of this study suggest
that patient self-report of illicit drug use may be unreliable. The findings also
suggest that legal and illegal substance abusers presenting for treatment of
mandible fractures have minimal nutritional deficiencies.
PMID- 10670594
TI - The use of the buccal fat pad for reconstruction of oral defects: review of the
literature and report of 15 cases.
AB - PURPOSE: Although the buccal fat pad (BFP) was originally used as an alternative
method for the closure of small to medium-sized oroantral and oronasal
communications, its use has now been extended to use after excision of oral
malignancies. This report describes experience with this technique. PATIENTS AND
METHODS: The BFP was used as a pedicled graft to reconstruct medium-sized
surgical defects of the oral soft and hard tissues in 15 patients suffering from
oral malignant tumors. Six of the defects were in the maxilla, 3 in the
retromandibular area, and 6 in the cheek and oral commissure. The BFP was left
uncovered to epithelialize in 14 patients, and in one it was covered with
lyophilized dura. RESULTS: The BFP healed without complications within 3 to 4
weeks in 13 patients, whereas in 2 patients with maxillary defects there was
partial loss of the graft, requiring the additional use of an obturator in 1 case
and a tongue flap in another to prevent oronasal leakage. Harvesting the graft
proved to be extremely easy, and care was only necessary to avoid severing the
supporting vascular plexus and the thin capsule covering the BFP. CONCLUSIONS:
The findings support the view that the BFP is a useful, easy, and uncomplicated
alternative method for the reconstruction of small to medium-sized surgical
defects of the oral hard and soft tissues.
PMID- 10670595
TI - Free fat transplantation for facial tissue augmentation.
AB - PURPOSE: This article reviews the lipofilling technique using a fat tissue
suspension obtained by manual or vacuum machine-assisted suction. PATIENTS AND
METHODS: Between 1989 and 1997 14 patients were treated by lipofilling. All
patients were female; 6 were treated for cheek and zygomatic area augmentation
for Romberg syndrome (2 cases) and bilateral facial lipodystrophy (4 cases); 4
were treated for nasolabial fold correction, 3 for lip augmentation, and 1 for
correction of systemic lupus erythematosus (LES) scars. RESULTS: Good results
were obtained in the treatment of the moderate Romberg syndrome case, with 3
stages of fat tissue transplantation from the abdominal area, in the severe
Romberg syndrome case that was treated with 3 stages of lipofilling after a
primary surgical procedure consisting of augmentation of the zygomatic region
using a composite temporal flap of calvaria bone and temporal muscle, in the 4
cases of bilateral facial lipodystrophy, and in the 4 cases of nasolabial fold
correction with 3 to 4 stages of lipofilling. Poor results were obtained in lip
augmentation, and bad results were obtained in correction of the LES scars.
CONCLUSIONS: Using the lipofilling technique with cannulas of 3 to 4 mm in
diameter and low-power manual aspiration to preserve the integrity of the fat
cells, good results were achieved in 10 of the 14 patients treated. The poor
results occurred in areas of reduced vascularity and high motility.
PMID- 10670596
TI - Force level and strain patterns during bilateral mandibular osteodistraction.
AB - PURPOSE: Recent reports have demonstrated that device orientation is important
during mandibular distraction osteogenesis. The purpose of this study was to
evaluate the force level and strain patterns on the mandible during bilateral
osteodistraction with devices oriented either parallel to the body of the
mandible or parallel to the sagittal axis of distraction. MATERIALS AND METHODS:
Five unembalmed human cadaver mandibles were placed in a specially designed
apparatus for stabilization of the proximal segments during distraction. A force
transducer was attached to the lateral aspect of the inferior ramus, and strain
gauges were attached to the mandibular bone segments proximal and distal to the
distraction device. Lateral force and bone strains were then measured at 5 and 10
mm of distraction. Osteodistraction proceeded first with the devices placed
parallel to the mandibular body, then parallel to the axis of distraction.
RESULTS: Significantly greater lateral forces were seen when the devices were
oriented parallel to the mandibular body. With this device orientation, increased
tensile strains were seen at the labial symphysis and medial ramus, and increased
compressive strains were found at the lingual symphysis and lateral ramus.
However, when the devices were oriented parallel to the axis of distraction, the
forces and strains were not detected. CONCLUSIONS: The results suggest that
device orientation has important biomechanical effects on lateral forces and
strain patterns during mandibular osteodistraction.
PMID- 10670597
TI - Prostaglandin E2 in temporomandibular joint synovial fluid and its relation to
pain and inflammatory disorders.
AB - PURPOSE: The aim of this study was to investigate temporomandibular joint (TMJ)
synovial fluid (SF) levels of prostaglandin E2 and its relation to general
inflammatory activity and its influence on specific TMJ pain in patients with
inflammatory TMJ disorders. PATIENTS AND METHODS: The study comprised 24 patients
(30 joints) with inflammatory TMJ disorders and 4 healthy persons (6 joints). TMJ
pain at rest, tenderness to palpation of the TMJ, and TMJ pressure pain
threshold, as well as pain during joint movements (PM), were assessed. PGE2
levels were analyzed in synovial fluid samples (SF-PGE2) and blood plasma (P
PGE2). The erythrocyte sedimentation rate (B-ESR) as well as the serum levels of
C-reactive protein (S-CRP) and antinuclear antibodies were determined. RESULTS:
PGE2 was undetectable in the plasma and in the TMJ SF of the healthy persons. In
the patients, PGE2 was detectable in 20 of the 30 (67%) SF samples. SF-PGE2 was
significantly and positively correlated to PM in the patients. There were
significant correlations between P-PGE2 and B-ESR as well as the S-CRP.
CONCLUSIONS: This study shows that the synovial fluid in patients with TMJ
inflammatory disorders frequently has a detectable level of PGE2 that is related
to TMJ allodynia. The plasma levels of PGE2 seem to be related to the general
inflammatory activity in these patients.
PMID- 10670598
TI - Effect of estrogen replacement on temporomandibular joint remodeling in
ovariectomized rats.
AB - PURPOSE: The investigation was performed to elucidate the effect of estrogen on
the temporomandibular joint (TMJ) and to evaluate the therapeutic effect of
17beta-estradiol replacement in growing rats. MATERIALS AND METHODS: Thirty 4
week-old female albino Wistar rats were divided into 3 groups. Ten rats were
ovariectomized followed by intramuscular administration of 17beta-estradiol for
hormone replacement (OVX + E2), 10 were sham operated (CTL), and 10 were
ovariectomized without hormone replacement (OVX). Five rats from each group were
killed at 1 and 2 weeks postoperatively, and the serum estrogen was determined to
verify the adequacy of replacement. The temporomandibular joints of the age
matched sham-operated control and ovariectomized groups were
histomorphometrically evaluated at the same periods. RESULTS: In OVX animals, the
thickness of the articular soft tissue was increased by a concomitant increase of
the transitional and cartilage zones in the anterior and posterior portions at 1
and 2 weeks postoperatively. However, the bone volume was decreased in the
anterior and posterior portions at 2 weeks after the surgery and the condyle was
flattened. Replacement with 17beta-estradiol restored most of the
histomorphometric parameters. The thickness of articular soft tissue was
increased in the anterior portion by an increase in the cartilage zone in the OVX
+ E2 group at 2 weeks postoperatively. Increase of bone volume was found at 2
weeks after hormone replacement with a corresponding increased osteoid surface
and decreased quiescent surface in the central portion at 1 week postoperatively.
A flattened condyle was still noted at 2 weeks postoperatively in the OVX + E2
animals despite the hormone replacement. CONCLUSIONS: Estrogen in a physiologic
concentration may play an important role in TMJ remodeling. Progesterone may be
indispensable for remodeling, particularly contributing to morphogenesis.
PMID- 10670599
TI - Management of heparin therapy in the high-risk, chronically anticoagulated, oral
surgery patient: a review and a proposed nomogram.
AB - PURPOSE: This study analyzes the use of a standard nomogram that can help reduce
the level of anticoagulation preoperatively to effectively manage perioperative
heparin therapy in chronically anticoagulated oral surgery patients who are at
high risk for thromboembolism. PATIENTS AND METHODS: Twenty patients with
significant cardiovascular disease, ranging in age from 56 to 79 years and
requiring oral surgery, were randomly divided into 2 groups. All patients were on
chronic warfarin therapy, and perioperative heparinization was recommended by
their cardiologist. Group A (n = 10) had their anticoagulation therapy managed
with the use of a standard nomogram. The heparin therapy for group B (n = 10) was
managed without the use of the nomogram. The records of all patients were
analyzed for therapeutic efficacy of heparinization, number of laboratory tests
required, duration of hospitalization, and complications related to
heparinization. RESULTS: Patients in group A did significantly better in all
parameters when compared with group B patients. There were no complications in
group A, whereas there was a 20% incidence of complications related to
anticoagulation therapy in group B. CONCLUSIONS: The use of a standard nomogram
to manage anticoagulation therapy in the oral surgery patient requiring
heparinization is strongly recommended. This provides optimal therapeutic
benefit, decreases the incidence of complications, and makes the hospitalization
less costly and more comfortable for the patient.
PMID- 10670600
TI - Tender swelling of the chin 40 years after genioplasty.
PMID- 10670601
TI - Current trends in the treatment of maxillofacial injuries in the United States.
AB - This report presents the results of a 1997 survey of the members of the America
Association of Oral and Maxillofacial Surgeons to assess the current national and
regional trends in the management of maxillofacial trauma. Comparisons are made
with the nearly identical survey done in 1987. The results show practitioner age
related differences and changes in reported practice across time. The
significance of these findings are discussed.
PMID- 10670602
TI - Ganglion cyst of the temporomandibular joint: report of case and review of
literature.
PMID- 10670603
TI - Management of early relapse after a sagittal split ramus osteotomy by gradual
callus distraction: a case report.
PMID- 10670604
TI - Surgical management of lingual thyroid: a report of four cases.
PMID- 10670605
TI - Joint formation between an osteochondroma of the coronoid process and the
zygomatic arch (Jacob disease): report of case and review of literature.
PMID- 10670606
TI - Brown tumor of the maxilla in a patient with secondary hyperparathyroidism: a
case study involving immunohistochemistry and electron microscopy.
PMID- 10670607
TI - Traumatic intracranial impaction of the zygoma: case report.
PMID- 10670608
TI - Descending necrotizing mediastinitis caused by an odontogenic infection: a case
report.
PMID- 10670609
TI - Is trabecular bone in the mandible different?
PMID- 10670610
TI - Pesticide safety training.
PMID- 10670611
TI - Survivors of torture.
PMID- 10670612
TI - Involving a community in a marine safety investigation.
PMID- 10670613
TI - 44.3 million in US lack health insurance.
PMID- 10670615
TI - NIH launches new publishing website.
PMID- 10670614
TI - GAO looks at state Medicaid enrollment post-welfare reform.
PMID- 10670616
TI - Providers, health plans clash over patient care.
PMID- 10670617
TI - Infertility: from a personal to a public health problem.
AB - The inability to conceive a child is most often viewed as a private matter, but
public health perspectives and skills can contribute greatly to our knowledge
about infertility, and the development of effective and rational public policy
for prevention, access to health care, and regulation of new technologies. We
offer a primer of public health aspects of infertility in an effort to encourage
the broad spectrum of public health professionals to become more knowledgeable
about these topics and join in the national debate about preventive strategies,
cost-benefit assessment, resource allocation, and ethics.
PMID- 10670618
TI - Mercury risks: controversy or just uncertainty?
PMID- 10670619
TI - Winston's "No Additives" campaign: "straight up"? "no bull"?
AB - OBJECTIVE: The author used data from a larger study to examine adolescents' and
adults' responses to Winston cigarettes' "No Additives" advertising campaign.
METHODS: The author analyzed responses from 400 adolescents ages 12-17 and 203
adults ages 30-50 who were asked what they believed the meaning of the "No
Additives" slogan to be. The author also analyzed adolescents' responses to
questions about four specific Winston "No Additives" ads. RESULTS: Two-thirds of
adolescents and 27% of adults believed that "No Additives" meant one or more of
the following: that Winston cigarettes are healthier than other cigarettes, that
they are less likely to harm health, or that they are less likely to be
addictive. Adolescents perceived the models in three ads to be younger than 25
years old. Among adolescent respondents, smokers were more likely than nonsmokers
to like the ads and to believe the ads made smoking more appealing. CONCLUSIONS:
The "No Additives" slogan was perceived by a majority of adolescents and about a
quarter of adults as implying one or more health claims. The results of this
analysis suggest that the Federal Trade Commission's action in requiring a
disclaimer on the "No Additives" ads is well founded but the disclaimer should be
strengthened.
PMID- 10670620
TI - A community strategy for Medicaid child dental services.
AB - OBJECTIVES: The authors present second-year utilization data and first- and
second-year cost data for a community-based program in Spokane County,
Washington, designed to increase access to dental care for Medicaid-enrolled
children from birth to 60 months of age. METHODS: The authors used Medicaid
eligibility and claims data for 18,727 children 5 years of age and younger to
determine utilization of dental care from January 15, 1996, through January 15,
1997. They also used accounting records from the agencies involved to calculate
the first- and second-year costs of the program. RESULTS: A child in the ABCD
program was 7.2 times as likely to have at least one dental visit as a Medicaid
enrolled child not in the program. Estimated costs per child with at least one
dental visit (in 1995 dollars) were $54.30 for the first year and $44.38 for the
second year, or $20.09 per enrolled child for the first year and $18.77 for the
second year. CONCLUSION: Public-private joint efforts are effective in improving
access to dental care for Medicaid-enrolled children.
PMID- 10670621
TI - Reducing firearm injuries: the role of local public health departments.
AB - OBJECTIVE: The purpose of this study was to gather data regarding local public
health departments' involvement in activities to prevent firearm-related
morbidity and mortality. METHODS: A questionnaire was sent to local public health
departments serving cities with populations > or =60,000 to assess their
perceptions of the magnitude of the firearm injury problem in their jurisdictions
and the activities in which they were engaged to reduce firearm-related injuries.
RESULTS: Almost half (49.7%) of respondents said that their departments had not
seriously thought about being involved in activities to reduce firearm-related
injuries, and fewer than one in five (17.8%) reported that their departments were
involved in such activities. Respondents identified three barriers to involvement
in activities to reduce firearm injuries: limited financial resources (62.7% of
respondents), lack of expertise (50.8%), and not enough time (47%). CONCLUSIONS:
Despite the extent of firearm injuries in the US, systematic collection of local
data on firearm morbidity and mortality to help guide policy development is
lacking.
PMID- 10670622
TI - Welfare reform: advocacy and intervention in the health care setting.
AB - Welfare reform has drastically altered the lives of poor families in the US. In
its wake, many former recipients are not receiving whatever transitional benefits
and other safeguards to which they remain entitled under federal and state laws.
Families are losing access to Medicaid and are not receiving the child care
assistance or Food Stamps for which they continue to be eligible. Ill-served by
stringent time limits and work requirements, lack of child care assistance, and
lack of training and educational opportunities for the development of skills that
will lead to better jobs, families need help to navigate the complexities of the
new welfare system. Boston Medical Center's Department of Pediatrics has
instituted a welfare screening project to educate families about their rights
under welfare reform and assist them in advocating for themselves and their
children.
PMID- 10670623
TI - Alaska's model program for surveillance and prevention of occupational injury
deaths.
AB - The National Institute for Occupational Safety and Health (NIOSH) established its
Alaska Field Station in Anchorage in 1991 after identifying Alaska as the highest
risk state for traumatic worker fatalities. Since then, the Field Station,
working in collaboration with other agencies, organizations, and individuals, has
established a program for occupational injury surveillance in Alaska and formed
interagency working groups to address the risk factors leading to occupational
death and injury in the state. Collaborative efforts have contributed to reducing
crash rates and mortality in Alaska's rapidly expanding helicopter logging
industry and have played an important supportive role in the substantial progress
made in reducing the mortality rate in Alaska's commercial fishing industry
(historically Alaska's and America's most dangerous industry). Alaska experienced
a 46% overall decline in work-related acute traumatic injury deaths from 1991 to
1998, a 64% decline in commercial fishing deaths, and a very sharp decline in
helicopter logging-related deaths. Extending this regional approach to other
parts of the country and applying these strategies to the entire spectrum of
occupational injury and disease hazards could have a broad effect on reducing
occupational injuries.
PMID- 10670624
TI - A forgotten enemy: PHS's fight against the 1918 influenza pandemic.
PMID- 10670625
TI - A collaborative effort to develop a data collection system.
PMID- 10670627
TI - Transplantation of highly differentiated immortalized human hepatocytes to treat
acute liver failure.
AB - BACKGROUND: Temporary support of a damaged liver by a bioartificial liver (BAL)
devise is a promising approach for the treatment of acute liver failure. Although
human primary hepatocytes are an ideal source of hepatic function in BAL,
shortage of human livers available for hepatocyte isolation is the limiting
factor for the use of this modality. A clonal human hepatocyte cell line that can
grow economically in culture and exhibit liver-specific functions should be an
attractive solution to this problem. METHODS: To test this alternative, primary
human fetal hepatocytes were immortalized using Simian virus 40 large T antigen.
To investigate the potential of the immortalized cells for BAL, we transplanted
the cells into the spleen of adult rats and performed a 90% hepatectomy 12 hr
later. RESULTS: One of the cloned human liver cell lines, OUMS-29, showed highly
differentiated liver functions. Intrasplenic transplanting of 20x10(6) OUMS-29
cells protected the animals from hyperammonemia and the associated hepatic
encephalopathy. Survival was significantly prolonged in 90% of hepatectomized
rats receiving OUMS-29 cells. CONCLUSIONS: A highly differentiated immortalized
human hepatocyte cell line, OUMS-29, was able to provide metabolic support during
acute liver failure induced by 90% hepatectomy in rats. Essentially unlimited
availability of OUMS-29 cells may be clinically useful for BAL treatment.
PMID- 10670626
TI - Long-term functional islet mass and metabolic function after xenoislet
transplantation in primates.
AB - BACKGROUND: Pancreatic islet transplantation (PIT) is an attractive alternative
for patients with type I diabetes mellitus. PIT is not yet an effective clinical
reality due in part to the high incidence of rejection and early loss of
functional islet mass. In addition, current immunosuppressive drugs have toxic
effects on islets and increase the risk of morbidity and mortality. In the
present study, the effects of PIT on glycemic parameters were assessed in
spontaneously diabetic primates. METHODS: Five insulinopenic nonhuman primates
(three Macacca fascicularis, one Ceropithecus aethiops, and one Macacca mulatta)
were studied. All required twice-daily treatment with 4-10 U of insulin. For
immunosuppression, the animals received anti-CD3-immunotoxin (100
microg/kg(initially infused 2 hr before transplantation and again on day +1),
cyclosporine (CsA) (20 mg/kg(i.v./2 hr before transplantation), cyclosporine
microemulsion (Neoral) 60 mg/kg/b.i.d. on days +1 to +3 with dose adjusted by
blood levels, and methylprednisolone (15 mg/kg day 0 to +3). Three recipients
were given islets from a single donor (M mulatta). The islets were prepared by a
semiautomated technique using Liberase. A mean of 13,136 islet equivalents/kg was
infused into the portal vein. Two animals (M fascicularis and M mulatta) were
used as a diabetic, nontransplanted control. Several metabolic parameters were
evaluated. RESULTS: All monkeys that underwent transplantation experienced
reversal of diabetes mellitus with normalization of all diabetic glycemic
parameters. In the nontransplanted primates given the same immunosuppression but
no PIT, diabetic metabolic parameters were unchanged after 9 months of follow-up.
In contrast, all three PIT recipients established fasting and nonfasting
euglycemia within 1-2 weeks, and none required exogenous insulin after day 10.
Normal intravenous glucose tolerance tests were observed at day 15, and no
significant differences in the glucose disappearance rate (Kg) were observed at
days 15, 45, 190, and 365 days after transplantation. The acute insulin response
to glucose indicated no significant reduction of functional islet mass.
CONCLUSIONS: PIT in severely insulinopenic type I diabetes mellitus primates
resulted in restoration of normal glycemic parameters and durable islet mass.
Operational tolerance was achieved with only 4 days of drug administration,
sparing the animals from chronic exposure to potentially diabetogenic
immunosuppressive drugs. These results offer an exciting new potential for type I
diabetes mellitus treatment.
PMID- 10670628
TI - IG-therasorb immunoapheresis in orthotopic xenotransplantation of baboons with
landrace pig hearts.
AB - BACKGROUND: The major problem of xenotransplantation is, that hyperacute
xenograft rejection (HXR) causes graft failure within minutes or a few hours
because of natural antibodies and activation of the complement system. As a
preclinical model we transplanted pig hearts orthotopically into baboons. To
prevent HXR after orthotopic xenotransplantation (oXHTx), the immunoglobulins
(Ig) and natural antibodies were adsorbed to reusable Ig-Therasorb
immunoadsorption (IA) columns. METHODS: We performed three oXHTx of landrace pig
hearts into baboons (19+/-6.8 kg), using extracorporeal circulation (ECC)
connected to the IA unit. After separating the recipient's blood into plasma and
cellular fraction by a plasma filter, plasma flow was directed to the Ig
Therasorb column coated with polyclonal sheep-antibodies against human IgG, IgM,
and IgA. Intraoperative treatment consisted of 4 cycles of IA. For a control, we
transplanted one pig heart into a baboon (16.9 kg) without applying IA.
Perioperatively, serum concentrations of Ig, anti-pig-antibodies, complement and
cardiac enzymes were determined. Tissue samples of myocardium were collected at
the end of the study for immunohistochemical examinations, light microscopic
examination (LM) and electron microscopic examination (EM). For cardiac
monitoring after oXHTx, we used ECG, echocardiography, and invasive measurement
of cardiac output. To prevent a mismatch of donor and recipient heart size, the
donor pig had a 30-40% lower body weight than the recipient baboon. RESULTS: Four
cycles of IA removed >80% of IgG, IgM, and IgA from plasma. The graft of the
control animal failed after 29 min. The first oXHTx with IA was intentionally
terminated after 100 min, the second oXHTx after 11 hr and the third oXHTx after
21 hr. All xenografts showed no histological signs of HXR. After weaning off ECC,
these donor hearts worked in sinus rhythm without electrocardiographic ST-segment
elevation. An excellent cardiac output was measured by echocardiography and
thermodilution (2 L/min). Serological parameters indicating cardiac damage were
significantly lower after IA if compared with the control experiment.
Macroscopically, the xenograft of the control animal showed massive hemorrhage in
comparison with the almost inconspicuous grafts after IA. The myocardium of the
IA group demonstrated fewer deposits of Ig and complement components compared
with the control animal. CONCLUSION: Baboons do not hyperacutely reject a porcine
xenograft after antibody depletion by the Ig-Therasorb column. In our experiment
only 4 cycles of immunoapheresis effectively prevented HXR after oXHTx of
baboons. The Ig-Therasorb column is a reusable device, which can be handled
easily in combination with the ECC. IA must be tested in oXHTx longterm survival
experiments, especially in combination with transgenic pig organs, which could be
a reliable preclinical approach for future clinical xenotransplantation.
PMID- 10670629
TI - Hepatocyte growth factor is essential for amelioration of hyperglycemia in
streptozotocin-induced diabetic mice receiving a marginal mass of intrahepatic
islet grafts.
AB - BACKGROUND: It is crucial for clinical islet transplantation to find a procedure
to improve the success rate of insulin independence after islet transplantation.
In the present study, we determined whether hepatocyte growth factor (HGF) has a
favorable effect on amelioration of hyperglycemia in streptozotocin (STZ, 200
mg/kg)-induced diabetic mice (C57BL/6) receiving a marginal mass of intrahepatic
islet isografts. METHODS: Isolated syngeneic islets were transplanted into the
liver of recipients. HGF with dextran sulfate (DS) was administered
intraperitoneally once a day at day 0, 2, 4, 6, and 8 relative to islet
transplantation. DS has been known to enhance the effect of HGF. RESULTS: It was
found that the number of 250 islets was a marginal mass as donor islets in this
model, in which 2 out of 14 diabetic mice receiving 250 islets became
normoglycemic by 90 days after transplantation. The treatment with HGF (100
microg) in conjunction with DS (200 microg) produced normoglycemia in all mice (n
= 5). Morphological study as well as intraperitoneal glucose tolerance test
revealed the beneficial effects of HGF. To our surprise, six out of nine mice
receiving 250 islets and treated with DS alone became normoglycemic. Additional
anti-HGF antibody treatment (100 microg, day -1, 0, 2, 4, 6, and 8) abolished the
effects of DS, indicating that the effect by DS is mediated via the endogenous
HGF. The effects of DS were not observed when the renal subcapsular space was the
site of islet transplantation. There was a significant increase in plasma HGF
levels in mice after the intrahepatic grafts but not the renal subcapsular one.
CONCLUSIONS: These findings demonstrate that HGF is essential for amelioration of
hyperglycemia in STZ-induced diabetic mice when a marginal mass of islets was
grafted into the liver. As the liver is the site of clinical islet
transplantation and the inability to achieve insulin independence after
transplantation is a major obstacle for successful transplantation, HGF may
facilitate to overcome such an important issue for clinical islet
transplantation.
PMID- 10670630
TI - Major histocompatibility complex class I peptide-pulsed host dendritic cells
induce antigen-specific acquired thymic tolerance to islet cells.
AB - BACKGROUND: As T-cell receptor-major histocompatibility complex (MHC) class
I/self peptide interaction regulates T-cell development in the thymus, we
reasoned that presentation of peptides by self dendritic cells (DC) to developing
T cells in the thymus might induce acquired thymic tolerance. This hypothesis is
based on the finding that intrathymic injection of allopeptides in the adult
animal induces acquired tolerance. To examine this hypothesis, we studied the
effects of intrathymic (IT) injection of a single immunodominant Wistar-Furth
(WF) MHC class I (RT1.Au) peptide-pulsed host DC on islet allograft survival in
the WF-to-ACI rat combination. METHODS: Bone marrow-derived ACI DC expressing MHC
class I and II, OX62, and ED2 present allopeptides to naive and specifically
peptide-primed syngeneic T cells in mixed lymphocyte reaction. Host DC pulsed
with RT1.Au peptide 5 (residues 93-109) were injected into the thymus of
streptozotocin-induced diabetic ACI that were transplanted 7 days later with
donor-type (WF) or third-party (Brown Norway [BN]) islets. RESULTS: Whereas IT
injection of 300 microg of peptide 5 alone led to normoglycemia and permanent
islet survival in three of six diabetic ACI recipients, similar treatment
combined with simultaneous intraperitoneal injection of 0.5 ml of anti-lymphocyte
serum (ALS) on day -7 led to 100% permanent islet allograft survival (>200 days)
compared to a mean survival time of 15.0+/-2.3 days in controls treated with ALS
alone. In contrast, similarly prepared animals rejected the third-party (BN)
islets in an acute fashion. To address the question of indirect allorecognition
in acquired thymic tolerance, we examined the effect of peptide-pulsed host DC on
graft survival. Whereas IT injection of peptide-pulsed host DC alone resulted in
permanent islet survival in two of five animals, IT injection of peptide-pulsed
host DC combined with 0.5 ml of ALS induced 100% donor-specific permanent islet
allograft survival in the WF-to-ACI rat combination. These results suggest that
thymic DC take up, process, and present the administered peptide to the
developing T cells by the indirect allorecognition pathway in the induction of
acquired thymic tolerance. CONCLUSION: We have demonstrated a novel approach to
inducing transplant tolerance to islet allografts with IT injection of
allopeptide-pulsed host DC. This finding suggests that immunization strategies
using DC expressing MHC allopeptides or peptide analogue might be potentially
useful in the treatment of autoimmune diabetes mellitus.
PMID- 10670631
TI - NOX 100, a nitric oxide scavenger, enhances cardiac allograft survival and
promotes long-term graft acceptance.
AB - BACKGROUND: We examined the role of nitrosative stress in allograft destruction.
METHODS: Rats undergoing cardiac transplants received NOX-100, a water-soluble
nitric oxide (NO) scavenger with antioxidant properties, with or without low-dose
cyclosporine (CsA). Graft survival, NO production, and nuclear factor kappa B (NF
kappaB) activity were studied. RESULT: Using NOX-100 daily until rejection
prolonged graft survival (11.6+/-0.6 vs. 7.4+/-0.2 days; P<0.05). Daily low-dose
CsA (2.5 mg/kg im) for 7 days or until rejection also prolonged survival (12.6+/
0.5 and 21.6+/-1.6 days, respectively; P<0.01 vs. Controls). Low-dose CsA for 7
days and NOX-100 for 30 days prolonged graft survival (45.0+/-4.7 days; P<0.01
vs. all groups.). NOX-100 had no effect on whole blood CsA levels. Combination
therapy until Day 100 resulted in 1 graft loss at Day 116 and indefinite survival
in 3 animals (>300 days), which accepted a second WF strain heart without further
immunosuppressive therapy but promptly rejected a third party (ACI) cardiac
allograft. NOX-100 and CsA reduced nitrate and nitrite, and combination therapy
completely normalized NO through to Day 30. Electron paramagnetic resonance
spectroscopic analysis demonstrated reduction of signals for nitrosylmyoglobin
and nitrosyl-heme with NOX-100 and elimination of signals with CsA alone or
combination therapy. Activity of myocardial NF-kappaB decreased with monotherapy
vs. untreated allografts. Combination therapy resulted in further inhibition of
NF-kappaB up to Day 30. The extent of graft survival correlated with the extent
of NO scavenging and NF-kappaB inhibition. Short-term combination therapy had no
effect on graft lymphocytic infiltrate on Days 15, 20, and 30. CONCLUSION: These
data support a role for both oxidative and nitrosative stress in rejection and
the immunoregulatory potential of antioxidant therapy after transplantation.
PMID- 10670632
TI - Effect of surrogate tolerogenesis on the vascular rejection of pig heart
xenografts.
AB - BACKGROUND: Organ xenografts are fulminantly rejected by antibody-mediated
vascular rejection. Surrogate tolerogenesis (ST), the induction of tolerance
within the donor, is effective with aorta xenografts. This preliminary study
assesses the effect of ST on preformed antibodies and rejection of porcine heart
xenografts. METHODS: Tolerance to the donor pig was induced by infusing recipient
marrow into fetal pigs. Later, pig splenocytes were transfused and heterotopic
pig hearts transplanted using chimeric or nonchimeric pigs. Anti-pig antibodies
were assessed. RESULTS: With ST alone, xenografts developed cellular rejection at
4-6 days, whereas control grafts developed vascular rejection at 3-4 days
(cellular vs. vascular, P<0.03). There was a reduction in preformed antibodies
(P<0.03). ST combined with moderate cyclosporine prevented rejection at 9+ and 25
days in sensitized recipients compared with vascular rejection at 0.5-2 days for
controls (P<0.07). CONCLUSIONS: ST seems to provide protection against vascular
rejection. The cellular rejection seems sensitive to cyclosporine.
PMID- 10670633
TI - Prolongation of canine liver allograft survival by a novel immunosuppressant,
FTY720: effect of monotherapy and combined treatment with conventional drugs.
AB - BACKGROUND: The immunosuppressive effect and other properties of a novel
immunosuppressant, FTY720, have been studied mostly in the experimental
transplantation of various extrahepatic organs. In this experiment, we evaluated
the antirejection potency and adverse effects of this agent on liver grafts using
a canine liver transplantation model. METHODS: Forty-eight orthotopic liver
transplantations were performed by the standard technique under a veno-venous
bypass. Liver recipients were divided into two studies: a single-dose study with
FTY720 at various doses and a combined dose study with conventional
immunosuppressants (cyclosporine or tacrolimus) alone and combined with FTY720.
Survival, biochemical and hematological tests, blood levels of
immunosuppressants, and postmortem histology were determined. RESULTS: The median
survival of untreated control animals was 9 days, whereas treatment with FTY720
at a dose of 0.1 mg/kg/day prolonged graft survival to 49.5 days. FTY720 at 1
mg/kg/day showed a slight but insignificant prolongation to 16 days, but when the
dose was increased to 5 mg/kg/day, the graft was rejected at 10 days. The
combination of FTY720, 0.1 mg/kg/day, with a subtherapeutic dose of cyclosporine,
5 mg/kg/ day, prolonged median animal survival from 40 days with cyclosporine
alone to 74 days. A combination of FTY720 (0.1 mg/kg/day) with tacrolimus (0.5
mg/kg/ day) compromised animal survival, reducing survival from 83.5 days with
tacrolimus alone to 30.5 days due to infectious complication and emaciation by
overimmunosuppression. No evident drug-induced side effects were observed.
CONCLUSIONS: FTY720 has a potent immunosuppressive effect when used alone at 0.1
mg/kg/day in canine liver transplantation. FTY720 is a promising candidate for
future clinical application in orthotopic liver transplantation.
PMID- 10670634
TI - Bile acids in xenogeneic ex-vivo liver perfusion: function of xenoperfused livers
and compatibility with human bile salts and porcine livers.
AB - BACKGROUND: In recent years, hepatic support systems using xenogeneic cells have
been developed to support patients in fulminant hepatic failure. The extent to
which xenogeneic hepatocytes metabolize and excrete human organic anions is
unclear. In these studies we examined the ability of the ex vivo porcine liver to
clear human bile acids during extracorporeal liver perfusion (ELP). METHODS: Four
patients with fulminant hepatic failure underwent extracorporeal liver perfusion
with 9 porcine livers. The venovenous circuit was designed as previously
described (NEJM,1994,331:234) as were the immunologic features (Transplantation
1994,58:1162). Bile from the porcine liver and serum samples were collected
hourly during perfusion. Three bile acids (glycocholic, glycodeoxycholic,
taurodeoxycholic acid) were selected as markers for human bile and three
(glycohyocholic, glycohyodeoxycholic, and glyco-3alpha-hydroxy-6-oxo-5beta
cholanoic acid) for markers of pig bile. Bile acids from both serum and bile were
processed and analyzed through high performance liquid chromatography. The
Students' t test was used for statistical analysis. RESULTS: The mean duration of
perfusions was 4.1+/-1.5 hr. The mean total bile acid clearance from serum (243+/
44 micromol/h) was similar to the total bile acid biliary excretion (286+/-84
micromol/hr, P = 0.06). After 1 hr of perfusion, bile samples demonstrated a
predominance of pig bile salts (65%). After 3 hr of perfusion, human bile acids
made up 85% of total biliary bile acids. Pig bile acids appeared in patients'
sera after 1 hr of perfusion, and after 3 hr, 35% of serum bile salts were pig
specific. CONCLUSIONS: Porcine livers perfused with human blood can clear the
serum of potentially toxic human bile acids and excrete them into bile.
Simultaneously, the percentage of pig-specific bile acids in patient serum
increases during xenogeneic perfusion for unknown reasons. The relative hepatic
uptake of bile acid from serum is similar to bile acid excretion in bile. Further
development of systems using porcine livers or hepatocytes is warranted.
PMID- 10670635
TI - The influence of pulsatile preservation on renal transplantation in the 1990s.
AB - BACKGROUND: Unlike simple cold storage (CS), pulsatile machine preservation (MP)
of kidneys for transplantation permits pharmacologic manipulation of the
perfusate and aids in the pretransplant assessment of the kidney graft. These
characteristics of MP may have importance in the era of increasing use of
extended criteria donor kidneys. The overall aim of this article is to critically
assess practices at our preservation unit with respect to graft function.
Specific aims are to (1) compare the influence of MP versus CS on graft function,
(2) determine which pretransplant variables have significance in pretransplant
assessment, and (3) determine whether pharmacologic manipulation during MP is
advantageous. METHODS: There were 650 consecutive kidneys preserved in our
laboratory between January 1, 1993 and March 1, 999, by either MP or CS. All MP
kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer
MPS or Belzer II solution. Perfusion parameters and electrolytes were measured
serially during pulsatile perfusion. All CS kidneys were stored in University of
Wisconsin solution. All kidneys obtained from donors exhibiting extended criteria
features underwent pretransplant frozen section biopsies. Transmission electron
microscopy (EM) was performed on a subset of kidneys undergoing pharmacologic
manipulation. Four agents were assessed prospectively for their ability to
influence MP characteristics when added to perfusate: PGE1, trifluoperazine,
verapamil, and papaverine. RESULTS: MP was associated with improved immediate, 1
, and 2-year graft function and reduced length of initial hospital stay when
compared with CS grafts. Changes in the machine perfusion variables flow and
resistance, and the [Ca++] in perfusate, were significantly associated with
delayed graft function (DGF) after the transplant. Biopsy information was not
predictive of DGF. The addition of PGE1 to perfusate improved MP characteristics,
reduced the release of [Ca++] into perfusate, and ameliorated mitochondrial
ischemic injury in transmission EM images. Early graft function was improved in
the presence of PGE1+MP, compared with function in the presence of other
pharmacologic agents or CS alone. CONCLUSIONS: MP is associated with improved
early and long term renal function. Moreover, PGE1 augments MP in improving graft
function. The combination of MP+PGE1 may be important in optimizing the ability
to use extended donor criteria kidneys and, thereby, improve the overall
efficiency of cadaveric renal transplantation.
PMID- 10670636
TI - Right lobe graft in living donor liver transplantation.
AB - BACKGROUND: For the sake of donor safety in living donor liver transplantation
(LDLT), the left lobe is currently being used most often for the graft. However,
size mismatch has been a major obstacle for an expansion of the indication for
LDLT to larger-size recipients, because a left lobe graft is not safe enough for
them. METHODS: In 1998, LDLT using a right lobe graft was introduced and
performed on 26 recipients to overcome the small-for-size problem. The right
lobe, which does not include the middle hepatic vein of the donor, was used.
Initially, indication for right lobe LDLT was basically defined as an estimated
left lobe graft volume/recipient body weight ratio (GRWR) of <0.8%, which was
later raised to <1.0%. RESULTS: All the donors recovered from the operation
without persistent complications. Two donors with transient bile leakage were
successfully treated with a conservative approach. A right lobectomy resulted in
more blood loss (337+/-175 ml), and a longer operative time (6.67+/-0.85 hr) than
a lateral segmentectomy, but not a left lobectomy. Grafts with a GRWR >0.8% were
implanted in all recipients, except for two, who received relatively smaller
right lobes (GRWR of 0.68% and 0.66%). In one of these two, the right lobe from
the donor was used as the orthotopic auxiliary graft. Postoperative transitory
increases in total bilirubin and aspartate transaminoferase for right lobe donors
were higher than those for the left lateral segmentectomy. Nineteen recipients
(73.1%) were successfully treated with this procedure. The causes of death were
not specific for right lobe LDLT, except for one patient with a graft that had
multiple hepatic venous orifices. These multiple and separate anastomoses of the
hepatic veins caused an outflow block as a result of a positional shift of the
graft, which finally led to graft loss. CONCLUSION: Our experience suggests that
right lobe grafting is a safe and effective procedure, resulting in the expansion
of the indication for LDLT to large-size recipients. How to deal with the
possible variation in the anatomy of the right lobe graft should be given
attention throughout the procedure.
PMID- 10670637
TI - Results of pancreas transplantation after steroid withdrawal under tacrolimus
immunosuppression.
AB - PURPOSE: The results of steroid withdrawal in pancreas transplant recipients
under tacrolimus immunosuppression were analyzed. METHODS: From July 4, 1994
until April 30, 1998, 147 pancreas transplantations were performed in 141
patients, including 126 simultaneous pancreas-kidney transplantations, 13
pancreas after kidney transplantation, and 8 pancreas transplantations alone.
Baseline immunosuppression consisted of tacrolimus and steroids without
antilymphocyte induction. Twenty-three patients were excluded from analysis
because of early graft loss in 17 cases, retransplantation in 5 cases, and
simultaneous pancreas-kidney transplantation after heart transplantation in 1
patient. RESULTS: With a mean follow-up of 2.8+/-1.1 years (range 1.0 to 4.8
years), complete steroid withdrawal was achieved in 58 (47%) patients with a mean
time to steroid withdrawal of 15.2+/-8 months (range 4 to 40 months after
transplantation). Of the entire cohort of 141 patients, overall 1-, 2-, and 4
year patient survival rates were 98%, 95.5%, and 86%, respectively. Overall 1-, 2
, and 4-year graft survival rates were 83%, 80%, and 71% (pancreas) and 95%, 91%,
and 84% (kidney), respectively. Of the 124 patients analyzed for steroid
withdrawal, 1-, 2-, and 4-year patient survival rates were 98%, 97%, and 92%,
respectively. Overall 1-, 2-, and 4-year graft survival rates were 98%, 91.5%,
83% (pancreas) and 97%, 95%, and 91% (kidney). Patient, pancreas, and kidney
survival rates at 1 year were 100%, 100%, and 98% (off steroids) versus 97%, 91%,
and 96% (on steroids, all NS) and at 4 years were 100%, 94%, and 95% (off
steroids) versus 78%, 68%, and 85% (on steroids, P = 0.01, 0.002, and NS,
respectively). The cumulative risk of rejection at the time of follow-up was 76%
for patients on steroids versus 74% for patients off steroids (P = NS). Seven
patients originally tapered off steroids were treated for subsequent rejection
episodes, which were all steroid sensitive, and two of these seven patients are
currently off steroids. Thirteen patients received antilymphocyte therapy for
steroid-resistant rejection, five of whom are now off steroids. Tacrolimus trough
levels were 9.3+/-2.4 ng/ml (off steroids) and 9.7+/-4.3 (on steroids, P = NS).
Mean fasting glucose levels were 98+/-34 mg/dl (off steroids) and 110+/-41 mg/dl
(on steroids, P = NS). Mean glycosylated hemoglobin levels were 5.2+/-0.9% (off
steroids) and 6.2+/-2.1% (on steroids, P = 0.02), and mean serum creatinine
levels were 1.4+/-0.8 mg/dl (off steroids) and 1.7+/-1.0 mg/dl (on steroids, P =
0.02). CONCLUSION: These data show for the first time that steroid withdrawal can
be safely accomplished in pancreas transplant recipients maintained on tacrolimus
based immunosuppression. Steroid withdrawal is associated with excellent patient
and graft survival with no increase in the cumulative risk of rejection.
PMID- 10670638
TI - Liver allotransplantation after extracorporeal hepatic support with transgenic
(hCD55/hCD59) porcine livers: clinical results and lack of pig-to-human
transmission of the porcine endogenous retrovirus.
AB - BACKGROUND: Whole organ extracorporeal perfusion of a genetically modified
humanized (transgenic) pig liver has been proposed as a technology that may
sustain patients with severe liver failure while awaiting human liver
transplantation. METHODS: We report on two cases of successful extracorporeal
perfusion of a transgenic pig liver in patients awaiting transplantation for
fulminant hepatic failure. The pig livers used were transgenic for human CD55
(decay-accelerating factor) and human CD59. These transgenic modifications are
designed to reduce or eliminate the hyperacute rejection inherent in pig-to
primate xenotransplants. We also report on the results of serial surveillance
testing for presence of the porcine endogenous retrovirus (PoERV) in these two
patients. RESULTS: Extracorporeal perfusion in two patients was performed for 6.5
and 10 hr, respectively, followed by the successful transplantation of a human
liver and resultant healthy patients (18 and 5 months later as of this writing).
The porcine livers showed evidence of synthetic and secretory function
(decreasing protime and bilirubin, bile production). Serial polymerase chain
reaction analysis of these patients' peripheral blood mononuclear cells has
failed to show presence of PoERV DNA sequences. CONCLUSIONS: The CD55/CD59
transgenic porcine liver appears capable of safely "bridging" a patient to liver
transplantation. Human PoERV infection from these livers has yet to be
demonstrated.
PMID- 10670639
TI - Outcome in recipients of dual kidney transplants: an analysis of the dual
registry patients.
AB - BACKGROUND: A novel but controversial method to increase the utilization of aged
donor kidneys is the transplantation of both kidneys as a dual transplant.
Initial single-center reports demonstrated outcomes similar to single kidneys
from younger donors. In this report, we compare outcome in recipients of kidneys
from donors > or =54 years of age who received a single kidney transplant
reported to the United Network for Organ Sharing Scientific Registry versus a
dual kidney transplant reported to the Dual Kidney Registry. METHODS: A
retrospective analysis was performed, comparing four donor and nine recipient and
outcome variables between recipients of a single versus a dual transplant between
March 1993 and March 1999. RESULTS: Dual versus single transplants from donors >
or =54 years of age have a significantly decreased incidence of delayed graft
function, and lower serum creatinines up to 2 years after transplant despite
having kidneys from significantly older donors with poorer HLA matching.
CONCLUSIONS: Dual kidney transplants improve graft performance and outcome in
recipients of kidneys from donors > or =54 years of age.
PMID- 10670640
TI - The kinetics of tolerance induction by nondepleting anti-CD4 monoclonal antibody
(RIB 5/2) plus intravenous donor alloantigen administration.
AB - BACKGROUND: CD4+ T cells play an essential role in allograft rejection. The
monoclonal anti-rat CD4 antibody, RIB 5/2, has been shown to modulate the CD4
glycoprotein without eliminating the recipient T cells. We have successfully
induced tolerance to rat heart allografts by recipient pretreatment with a single
dose of RIB 5/2 plus intravenous administration of donor splenocytes. In this
study, we explored whether this potent regimen could induce tolerance to the more
resistant kidney and skin allografts. Furthermore, we examined the kinetics and
requirements for tolerance to be met by a single dose of RIB 5/2 plus i.v.
alloantigen. METHODS: The efficacy of a single i.p. dose of 20 mg/kg RIB 5/2 plus
i.v. donor antigen (25x10(6) splenocyte) pretreatment 0, 21, or 40 days before
receipt of an MHC-mismatched Lewis (RT1l) to Buffalo (RT1b) rat cardiac, renal,
or skin allograft was studied. Another group of Buffalo recipients treated with
RIB 5/2 plus an i.v. alloantigen +/-thymectomy received kidney transplants after
40 days. Attempts to prevent tolerance used interleukin-2 or prior sensitization.
Mixed lymphocyte cultures, cytotoxic assays, and precursor frequencies of helper
and cytotoxic cells, by limiting dilution analysis, serially measured in vitro
cell-mediated immunity. RESULTS: RIB 5/2 administration combined with i.v.
alloantigen 21 days before induced tolerance to heart and kidney allografts but
did not prolong skin graft survival. In contrast, kidney allografts delayed for
40 days after pretreatment were acutely rejected and survival was not affected by
the thymectomy. MLC, CTL, and pTH, and pCTL precursor frequencies from recipients
of long-term grafts were specifically suppressed to donor, but not third party,
alloantigen. CONCLUSION: A single dose of the nondepleting anti-CD4 monoclonal
antibody, RIB 5/2, plus i.v. alloantigen is a potent inducer of tolerance to
heart and kidney, but not skin, allografts. The RIB 5/2-induced donor
unresponsiveness to a delayed kidney or cardiac allograft is time dependent but
can be prolonged if specific alloantigen is present. Suppression of cell-mediated
allo-immune responsiveness correlates with allograft acceptance.
PMID- 10670641
TI - Brief cyclosporine treatment prevents intrathymic (IT) tolerance induction and
precipitates acute rejection in an IT rat cardiac allograft model.
AB - BACKGROUND: Intrathymic (IT) alloantigen combined with administration of rabbit
anti-rat anti-lymphocyte serum (ALS) intraperitoneally induces donor-specific
tolerance to rat cardiac transplants. The purpose of this study was to examine
the effect of a brief course (4 days) of cyclosporine (CsA) on the development of
IT tolerance. METHODS: Buffalo (BUF) (RT1b) rats were given 25x10(6) fully MHC
mismatched Lewis (LEW) (RT1l) splenocytes by IT injection plus 1.0 ml of ALS
intraperitoneally. Twenty-one days later, IT donor-specific LEW (group 1) or
third-party (ACI, RT1a) (group 2) hearts were heterotopically transplanted to the
abdominal aorta A third group of BUF (group 3) were given daily CsA (10 mg/kg) by
oral gavage for 4 days before administration of IT LEW cells and ALS. Rejection
as defined by the cessation of a palpable heartbeat was confirmed by histology.
Cytokine profiles of allografts from all groups were then analyzed using a multi
probe RNase protection assay. RESULTS: Sixty-seven percent of IT/ALS-treated BUF
recipients not pretreated with CsA accepted LEW heart grafts for greater than 90
days. However, 86% of animals treated with CsA for 4 days before IT injection and
ALS rejected allografts at 10.7+/-3.2 days. Third-party allografts (ACI) were
uniformly rejected (7.0+/-0.0 days). Histology confirmed cellular rejection in
CsA-treated allografts and cytokine analysis detected increased interleukin (IL)
3, IL-5, and tumor necrosis factor-alpha when compared to increased IL-2 and
interferon-gamma in rejecting untreated controls. CONCLUSIONS: CsA can prevent
the induction of intrathymic alloantigen tolerance. These results support the
development of a CsA-sensitive, but IL-2-independent, active regulatory mechanism
after intrathymic exposure to donor-specific alloantigen and depletion of mature
peripheral T cells.
PMID- 10670642
TI - Both ischemic and pharmacological preconditioning decrease hepatic
leukocyte/endothelial cell interactions.
AB - BACKGROUND: Ischemic preconditioning has been shown to protect some tissues from
ischemia/reperfusion (I/R) injury. Adenosine is believed to play an important
role by attenuating leukocyte-endothelial cell adhesive interactions.
Dipyridamole increases adenosine bioavailability. The purpose of this study was
to evaluate the effects of mechanical (MPC) and pharmacological preconditioning
(PPC) on leukocyte endothelial cell interaction in hepatic I/R injury. METHODS:
C57BL6 mice were subjected to 30 min of ischemia to the left lobe of the liver.
Groups tested at 30 min, 2, 5, 12, and 24 hr of reperfusion had 1) sham
laparotomy (n = 10, 2) I/R (n = 25), 3) ischemic preconditioning with 5 min of
ischemia and 10 min reperfusion before I/R (n = 25), and 4) (PPC) with
dipyridamole (n = 25). Intravital microscopic examination was used to assess
leukocyte/endothelial cell adhesion. Blood was drawn for leukocyte counts and
liver function tests. RESULTS: A significant decrease in leukocyte rolling was
observed at 30-min and 5-hr reperfusion intervals in the PPC and ischemic
preconditioning groups compared with the I/R group. A significant decrease in
leukocyte saltation was also observed in the PPC and MPC groups at 2, 5, and 12
hr of reperfusion when compared with the I/R group. aspartate aminotransferase
was significantly decreased in the 5-hr preconditioning groups. There was not a
significant decrease in the white blood cell count because of PPC or MPC vs. I/R
CONCLUSIONS: Preconditioning decreases endothelial/ leukocyte interaction and
reduces liver damage as measured by aspartate aminotransferase. These data prove
that IPC and PPC provide some degree of hepatic protection in I/R injury.
PMID- 10670643
TI - Defining hepatocellular chimerism in a liver failure patient bridged with
hepatocyte infusion.
AB - BACKGROUND: A practical method of monitoring engraftment by transplanted
hepatocytes for the purpose of bridging human liver failure to native
regeneration is described. METHODS: A previously healthy 37-year-old female with
a 2-week history of a febrile illness presented with fulminant liver failure.
Findings on admission included the following: illicit drug use, serum hepatitis B
surface antigen positive, grade 1 encephalopathy, prothrombin time (pt) >100 sec,
F7<1%, NH3 150 micromol/L, alanine aminotransferase 4079 U/L, total bilirubin
level 11.4 mg/dl, and glucose 70 mg/dl (on IV D10). With immunosuppression,
8.8x10(8), 96% viable human hepatocytes were intraportally infused. Clinical
chemistries, total sHLA class I, and ELISA to measure donor-specific sHLA-A1 and
B8 were recorded. Serial transjugular liver biopsies were performed and pooled
for histological examination, DNA extraction, and HLA DNA typing. RESULTS: The
patient fully recovered. At months 3 and 4 with donor biopsy specimen class I HLA
DNA no longer detectable, immunosuppression was tapered off. The patient is
clinically normal, serum hepatitis B surface antigen negative at 10 months of
follow-up. CONCLUSIONS: Bridging liver failure with donor hepatocytes with HLA
class I antigen disparate from recipients is clinically feasible, and allows for
a marker, combined with serial graft histology, to safely wean immunosuppression
when native liver regeneration succeeds.
PMID- 10670644
TI - Experience with daclizumab in liver transplantation: renal transplant dosing
without calcineurin inhibitors is insufficient to prevent acute rejection in
liver transplantation.
AB - BACKGROUND: Daclizumab is a monoclonal antibody directed against the alpha chain
of the interleukin 2 receptor. We review our experience with the use of
daclizumab in liver transplant recipients. METHODS: Thirty-two patients were
given daclizumab as induction therapy in the setting of hepatic transplantation.
Seven of these patients were enrolled in a pilot study to determine the efficacy
of daclizumab in conjunction with corticosteroids and mycophenolate mofetil
without the initial use of calcineurin inhibitors (CI). The remaining 25 patients
received daclizumab, mycophenolate mofetil, and steroids, with the institution of
CI generally within the first postoperative week. The majority of these patients
(n = 17) had some degree of renal insufficiency. RESULTS: The pilot study was
halted after the first seven patients were enrolled because of an unacceptably
high rate of rejection (7/7 = 100%). The patients outside of this pilot study,
however, had a much lower rate of rejection (36%). The incidence and severity of
rejection correlated with the delay in institution of CI. The described dosing
schedule resulted in subtherapeutic daclizumab levels in liver transplant
recipients. CONCLUSIONS: Daclizumab used in liver transplant recipients without
any CI was ineffective and can potentially lead to steroid-resistant rejection.
The dosing regimen used in renal transplant recipients is most likely
insufficient for liver transplant patients. However, daclizumab can be used
safely in patients with preexisting or postoperative renal dysfunction in
conjunction with low doses of CI given within the first week postoperatively.
PMID- 10670645
TI - Cadaveric versus living donor kidney transplantation: a Medicare payment
analysis.
AB - BACKGROUND: We found previously that the clinical advantages of living donor (LD)
renal transplantation lead to financial cost savings compared to either cadaveric
donation (CAD) or dialysis. Here, we analyze the sources of the cost savings of
LD versus CAD kidney transplantation. METHODS: We used United States Renal Data
System data to merge United Network for Organ Sharing registry information with
Medicare claims data for 1991-1996. Information was available for 42,868 CAD and
13,754 LD transplants. More than 5 million Medicare payment records were
analyzed. We calculated the difference in average payments made by Medicare for
CAD and LD for services provided during the first posttransplant year. RESULTS:
Average total payments were $39,534 and $24,652 for CAD and LD, respectively
(P<0.0001) during the first posttransplant year. The largest source of the
difference in payments was in inpatient hospitals, representing $10,653.67
(P<0.0001). For patients who had Medicare as the primary payer, average
transplant charges were significantly higher for CAD donation ($79,730 vs.
$69,547, P<0.0001); average transplant payments demonstrated no statistical
differences ($28,483 vs. $28,447, P = 0.858). Therefore, inferred profitability
was significantly higher for LD. CONCLUSIONS: Medicare payments are remarkably
lower for LD compared to CAD in every category. The single largest cost saving
comes from inpatient hospital services. A portion of the savings from LD could be
invested in programs to expand living kidney donation.
PMID- 10670646
TI - Influence of surgical procedures on interleukin-6 and monocyte chemotactic and
activating factor responses: CABG vs. valvular surgery.
AB - Interleukin-6 (IL-6) and monocyte chemotactic and activating factor/monocyte
chemoattractant protein-1 (MCAF/MCP-1) play pivotal roles in systemic
inflammation, immune response, and tissue damage after cardiopulmonary bypass
(CPB). Previous reports have described transient rises in IL-6 and MCAF after
CPB, but the data seem to vary according to the different surgical procedures
used. To evaluate the influence of the different surgical procedures on the
proinflammatory cytokine responses, we compared perioperative serum IL-6 and MCAF
release in coronary artery bypass grafting (CABG) and valvular surgery cases.
Eighteen CABG (CABG group) and 7 single valvular cardiac surgery patients (valve
group) were included in this study. Blood samples were taken to measure the serum
concentrations of IL-6 at the induction of anesthesia, at the removal of the
aortic cross-clamp, at the end of CPB, at the end of surgery, and 24 h after the
termination of surgery. Serum IL-6 and MCAF were assayed by ELISA. Serum IL-6
increased immediately after aortic declamping and reached its peak at the end of
surgery in both groups. Serum IL-6 concentrations at the end of surgery and 24 h
after surgery were significantly higher in the valve group than in the CABG group
(123.9 +/- 21.7 pg/ml vs. 79.7 +/- 10.4 pg/ml, p = 0.049; 113.6 +/- 25.0 pg/ml
vs. 39.9 +/- 11.5 pg/ml, p = 0.006, respectively). Serum MCAF increased
immediately after aortic declamping, and the MCAF level at the end of surgery was
significantly higher in the valve group than in the CABG group (1118.4 +/- 353.9
pg/ml vs. 241.0 +/- 71.2 pg/ml, p = 0.002, respectively). IL-6 and MCAF may play
important roles in the pathophysiology of surgical damage with CPB, and the
different surgical procedures appear to affect the proinflammatory cytokine
release after cardiac surgery differently.
PMID- 10670647
TI - Orthodontic movement induces high numbers of cells expressing IFN-gamma at mRNA
and protein levels.
AB - Cytokines are important signaling proteins that are liberated during immune
challenges and exhibit many modulatory activities. However, their role in
periodontal modeling during orthodontic tooth movement is not fully understood.
The aim of this study was to analyze effects of mechanical force during
orthodontic tooth movement, in the pressure zone, on the induction of interferon
gamma (IFN-gamma) as a proinflammatory cytokine of Th1 type and interleukin-4 (IL
4)/IL-10 as anti-inflammatory cytokines of Th2 type. In 12 Wistar rats 40-45 days
old, the maxillary first molar was moved mesially by means of a closed coil
spring for 3, 7, and 10 days. The contralateral side served as a control. IFN
gamma, IL-4, and IL-10 mRNA were determined by in situ, hybridization, and
protein levels of IFN-gamma was measured by immunohistochemistry. Induction of
IFN-gamma at both mRNA and protein levels was significantly higher on the
experimental side than on the contralateral control side on day 3. The signal
gradually became stronger on day 7 and remained high on day 10. Cytokines of the
Th2 type (IL-4 and IL-10) were not detected at all examined time points in both
pressure and contralateral control sides. Considering the potential
immunoregulatory roles played by IFN-gamma, our data suggest that IFN-gamma may
be involved in periodontium remodeling during orthodontic tooth movement.
PMID- 10670648
TI - A Stat1alpha factor regulates the expression of the human vimentin gene by IFN
gamma.
AB - Vimentin is an intermediate filament protein normally expressed in cells of
mesenchymal origin. Here, we report an increase in vimentin gene transcription
induced by the cytokine interferon-y (IFN-gamma). Northern blot analysis and
reporter gene assays reveal that IFN-gamma induces vimentin gene transcription in
HeLa cells. However, no increase in vimentin mRNA synthesis was observed de novo
in MCF-7 cells, which do not already express vimentin. Band shift analysis shows
that the Stat1alpha protein mediates vimentin induction by IFN-gamma. A human
mutant fibroblast cell line (U3A), which lacks Stat1alpha but expresses vimentin
mRNA, yields no increase in vimentin mRNA levels on the addition of IFN-gamma.
These results suggest that the induction of vimentin gene expression might be an
important part of a complex cellular response to IFN-gamma.
PMID- 10670649
TI - Transduction and utility of the granulocyte-macrophage colony-stimulating factor
gene into monocytes and dendritic cells by adeno-associated virus.
AB - The genetic manipulation of antigen-presenting dendritic cells (DC) offers
promise for stimulating the immune response, in particular for anticancer and
antiviral protocols. As adeno-associated virus (AAV) has shown promise as a gene
delivery vector for transducing a variety of hematopoietic cell types, we have
investigated AAV's ability to genetically alter DC. In this analysis, we modified
the standard granulocyte-macrophage colony-stimulating factor (GM-CSF) and
interleukin-4 (IL-4) treatment of adherent monocytes to generate DC. In our
protocol, adherent monocytes were first infected with an AAV/GM-CSF/Neo vector,
and the addition of IL-4 was delayed for 2 days to allow for a brief period of
monocyte proliferation. AAV-mediated transduction of the GM-CSF and Neo genes
into monocytes/DC precursors was demonstrated by G418 selection, GM-CSF
secretion, GM-CSF RNA expression (reverse transcriptase-polymerase chain reaction
amplification [RT-PCR]), and cell proliferation. Cells resulting from infection
with AAV/GM-CSF/Neo virus, and subsequent IL-4 and tumor necrosis factor-alpha
(TNF-alpha) treatment, displayed multiple classic markers consistent with mature
DC. Finally, chromosomal integration of the AAV vector was also demonstrated in
sorted CD83+ DC. These data strongly suggest that AAV vectors will be useful for
the genetic manipulation of DC and suggest that the transduction of the GM-CSF
gene was able to fully replace the need for exogenous GM-CSF in the production of
mature DC.
PMID- 10670650
TI - Restoration of cytotoxic T lymphocyte function in malignant pleural effusion:
interleukin-15 vs. interleukin-2.
AB - The present study attempts to define the role of interleukin-15 (IL-15), as
compared with IL-2, in generating cytotoxic T lymphocytes (CTL) from the
malignant effusions of cancer patients. Effusion-associated lymphocytes (EAL)
from malignant effusion were incubated with IL-15 or IL-2 with or without
alphaCD3. Proliferation and cytotoxicity assays were performed. IL-15 was found
to have at least an equivalent, if not higher, activity to IL-2 in terms of
lymphocyte proliferation and generation of CTL from EAL. The proliferative
response of EAL, cocultured with IL-15, with or without alphaCD3, was partly
inhibited by pretreatment with an anti-IL2 receptor beta chain monoclonal
antibody (mAb). The proliferative response of EAL, cocultured with alphaCD3, IL
2, or both, was partly inhibited by pretreatment with an anti-IL-2 receptor alpha
chain mAb. Overnight [5lCr] release assays against K562, Daudi, and the patients'
autologous tumor cells were done to evaluate EAL's cytolytic activity. MHC class
I Ab blocked the stimulated cytolytic activity of EAL against autologous tumors.
An mAb depletion assay showed that the phenotype of the restored EAL was CD16-CD4
CD8+; thus, the restored activity of EAL was CTL activity. The results suggest
that both IL-15 and IL-2 can restore CTL activity from EAL in the presence of T
cell receptor (TCR)-CD3 engagement, but the effect of IL-15 was superior.
PMID- 10670651
TI - Acute-phase proteins and hematologic values in ovine lentivirus-infected lambs
treated with recombinant ovine IFN-tau.
AB - To evaluate changes in complete blood cell (CBC) counts, haptoglobin and
fibrinogen in ovine lentivirus (OvLV)-infected lambs treated with recombinant
ovine interferon-tau (rOVIFN-tau), 24 lambs were allocated to one of four groups
(n = 6 per group): (1) virus + rOvIFN-tau, VI, (2) virus + placebo, VP, (3) no
virus + rOVIFN-tau, NVI, and (4) no virus + placebo, NVP. Three lambs in each
group were treated once a day for 12 weeks, and the remaining 3 lambs were
treated for 33 weeks. Blood was collected at days 0, 7, and 10 and at weeks 2-10,
12, 32, and 33 to determine CBC counts, as well as haptoglobin and fibrinogen
levels. Hematologic values remained within normal limits in all groups. However,
hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin
concentration (MCHC), and packed cell volume (PCV) values decreased (p < 0.05) in
the two rOvIFN-tau-treated groups (VI and NVI) compared with the placebo-treated
(VP and NVP) groups. Both rOvIFN-upsilon and OvLV had a mild negative effect on
neutrophil numbers. Although Hb, MCV, MCHC, PCV, and neutrophil values declined
in the rOvIFN-tau-treated lambs compared with the placebo-treated lambs, these
values remained within the reference range for sheep. Experimental lambs did not
show adverse clinical signs associated with OvLV infection or as a result of
rOvIFN-tau treatment. The lack of significant side effects of high-dose rOvIFN
tau in sheep and previous reports of broad-spectrum and cross-species antiviral
activity suggest that rOvIFN-tau warrants further investigation as an antiviral
therapeutic agent.
PMID- 10670652
TI - Characterization of the cytokine network at a single cell level in mice with
collagen-induced arthritis using a dual color ELISPOT assay.
AB - Collagen-induced arthritis (CIA) in mice has been classified as a Thl-mediated
disease. However, most evidence for this has been obtained by indirect
experiments; for example, the administration of neutralizing anti-interferon
gamma (IFN-gamma) antibody reduced the severity of arthritis. To obtain direct
evidence about the cytokine balance in CIA mice, we analyzed the cytokine
secreting cell in CIA mice at the single cell level using a dual color enzyme
linked immunospot (ELISPOT) assay, which enabled us to analyze interleukin-2 (IL
2)-secreting cells or IL-4-secreting cells or both simultaneously. Furthermore,
to characterize the cytokine network in the pathogenesis of CIA, the frequency of
the cells secreting IL-12, which induced the development of naive Th cells into
Th1 cells, was analyzed. The results show that in the prearthritic phase, the
number of IL-12-secreting cells in spleen and peritoneal exuded cells is
increased, and Th1 cells in lymph node and spleen are dominant. In contrast,
after the onset of clinical arthritis, the number of IL-12-secreting cells in
spleen, lymph node, and peritoneal exuded cells is decreased, and there is a
shift from a Thl-dominant to a Th2-dominant state in lymph node and spleen. The
results indicated that the pathogenesis of CIA is associated with a disruption in
the normal ratio of Th1/Th2 at cell level.
PMID- 10670653
TI - The capacity to produce IFN-gamma rather than the presence of interleukin-4
determines the resistance and the degree of susceptibility to Leishmania donovani
infection in mice.
AB - The immune response against Leishmania donovani infection has been investigated
in one resistant mouse strain (C3H/HeJ) and three susceptible mouse strains
(C57BL/6, BALB/c, and B10D2/n). In order to correlate the strain-specific course
of infection with the individual T cell response phenotype, the ex vivo cytokine
secretion patterns of splenic lymphocytes were assessed by ELISA (interferon-y
[IFN-gamma], interleukin-4 [IL-4], IL-10) or by bioassay (IL-2). The strain
dependent differences in the course of infection correlated closely with the
potency of T cells to produce IFN-gamma. C3H/HeJ mice produced high amounts of
IFN-gamma before and during infection, whereas susceptible mice produced low
amounts of IFN-gamma early during L. donovani infection. However, C57BL/6 mice,
which recovered from the infection rapidly after the acute stage, developed
marked IFN-gamma response within the first 30 days of infection. In contrast, in
BALB/c and B10D2/n mice, the IFN-gamma production diminished during the acute
stage, and this was associated with a delay in recovery and with subsequent
switching into the chronic stage. Interestingly, CD8+ T cells contributed
significantly to IFN-gamma production during this phase. In contrast to IFN-y,
the levels of IL-4 in response to antigen or mitogen ex vivo were always very
low. Moreover, neutralization of endogenous IL-4 in vivo by treatment with
soluble murine IL-4 receptor did not result in significant decreases in the
parasite burdens in spleen and liver but did cause a decrease in the serum IgE
level of L. donovani-infected BALB/c mice. These results confirm that in visceral
leishmaniasis a Thl-dominated immune response is protective against the L.
donovani parasites and, furthermore, that the capacity to produce IFN-gamma
rather than the presence of IL-4 determines the efficacy of the immune response
in susceptible mice. The data show that CD8+ T cells represent an important
source of IFN-gamma during L. donovani infection in susceptible mice, implying a
role for this cell type in healing and development of protective immunity.
PMID- 10670654
TI - A sensitive and versatile bioassay for ligands that signal through receptor
clustering.
AB - The induced expression of xanthine-guanine phosphoribosyl transferase (XGPRT) by
low concentrations (-2 pg/ml) of interferon-alpha (IFN-alpha) or IFN-beta, in the
2fTPGH cell line caused a 50% cytotoxicity when these cells were grown in medium
containing 6-thioguanine. We extended the application of this sensitive,
reliable, and easy bioassay to other members of the cytokine family. To activate
the IFN signaling pathway, we made receptor chimeras, consisting of the IFN type
I receptor intracellular and transmembrane domains, fused to either the
interleukin-5 (IL-5) receptors or erythropoietin (Epo) receptor extracellular
domains as model systems. 2fTGH cells, stably transfected with these receptor
chimeras, responded to very low concentrations of IL-5 or Epo (IC50 values of
approximately 15 pg and 3 pg/ml, respectively) and thus can be used as a very
sensitive bioassay for both ligands. Background activity of IL-5, Epo, tumor
necrosis factor (TNF), IL-6, or leptin on cells that did not carry the receptor
chimeras was very low. This methodology can in principle be extended to any
ligand that acts via clustering of its receptors.
PMID- 10670655
TI - Resistance to Paracoccidioides brasiliensis infection is linked to a preferential
Th1 immune response, whereas susceptibility is associated with absence of IFN
gamma production.
AB - The secretion of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-4, IL-5,
and IL-10 by antigen-stimulated lymph node cells, eosinophil maturation, and the
antibody isotypes produced were examined during intraperitoneal infection of
susceptible (B10.A) and resistant (A/Sn) mice with Paracoccidioides brasiliensis.
Lymph node cells from resistant mice produced early and sustained levels of IFN
gamma and IL-2, whereas susceptible animals secreted low to undetectable amounts
of these type 1 cytokines. Both mouse strains presented late and transient
production of IL-4, whereas IL-10 was produced constantly throughout the course
of disease. Resistant animals produced increasing levels of IL-5 in the chronic
phase of the infection (from the eighth week on), whereas susceptible mice showed
two peaks of IL-5 production, at the first and twelfth weeks after infection.
Only the susceptible strain presented medullary and splenic eosinophilia
concomitant with the raised IL-5 production. In resistant mice, the levels of
IgG2a antibodies were significantly higher than those observed in susceptible
mice, which preferentially secreted IgG2b and IgA isotypes. Taken together, these
results demonstrate that a sustained production of IFN-gamma and IL-2 and a
predominant secretion of IgG2a antibodies are associated with resistance to P.
brasiliensis. In contrast, the production of low levels of IFN-gamma, early
secretion of high levels of IL-5 and IL-10, eosinophilia, and a preferential
secretion of IgG2b and IgA isotypes characterize the progressive disease in
susceptible animals.
PMID- 10670656
TI - Leptin expression is reduced with acute endotoxemia in the pig: correlation with
glucose, insulin, and insulin-like growth factor-1 (IGF-1).
AB - Leptin has been implicated in the regulation of anorexia associated with cachexia
in rodents and humans. Regulation of leptin expression is under complex endocrine
and metabolic control. To determine if leptin expression is regulated by acute
inflammation and to define the endocrine and metabolic factor(s) that regulates
leptin expression during acute inflammation, castrate male pigs (ad libitum fed,
used as their own controls) were treated with saline (control period) and
endotoxin (lipopolysaccharide [LPS] period). Frequent blood samples were
collected to identify dynamic changes in hormones and metabolites that are known
to regulate leptin expression. LPS caused fever and elevated plasma cortisol (p <
0.0004), tumor necrosis factor-alpha (TNF-alpha) (p < 0.0001), and plasma
nonesterified fatty acids (NEFA) (p < 0.001) compared with control. Circulating
insulin (p < 0.01), glucose (p < 0.003), and insulin-like growth factor-1 (IGF-1)
(p < 0.0001), as well as adipose leptin mRNA abundance (p < 0.01), were
profoundly reduced following LPS treatment compared with control. Our data
indicate that during acute endotoxemia (1-10 h after injection), leptin gene
expression is decreased compared with ad libitum fed animals and is more closely
related to energy homeostasis than cytokine profiles in plasma.
PMID- 10670657
TI - IFN-alpha1 plasmid construct affords protection against HSV-1 infection in
transfected L929 fibroblasts.
AB - The purpose of the present study was to evaluate the resistance against herpes
simplex virus type 1 (HSV-1) using an interferon-alpha1 (IFN-alpha1) transgene in
specifically targeted cells in vitro. Transfection of mouse fibroblast L929 cells
with an IFN-alpha1 plasmid construct reduced viral load and viral gene expression
in a time-dependent fashion. Supernatants from IFN-alpha1-transfected cells
augmented natural killer (NK) cell activity, and such an effect was antagonized
with neutralizing antibody to IFN-alpha/beta. In addition, transfected cells
displayed an increase in the IFN inducible genes (2',5'-oligoadenylate synthetase
[2',5'-OAS], T cell-specific guanine nucleotide triphosphate-binding protein, IFN
regulatory factor 1 [IRF-1], and major histocompatibility complex [MHC] class I)
compared with plasmid vector-treated controls. Collectively, these results show
that IFN-alpha1 transfection of cells in vitro induces or upregulates a spectrum
of IFN-regulated genes involved in the direct or indirect antiviral action of
this cytokine. In addition, the transgene significantly increases the resistance
of transfected cells in vitro to HSV-1 infection.
PMID- 10670658
TI - Models for predicting subjective quality of life in individuals with traumatic
brain injury.
AB - The objective of this study was to compare the utility of ICIDH-based models and
needs-based models for predicting subjective quality of life in individuals with
traumatic brain injury (TBI). Using an existing data base of individuals with TBI
living in the community, seven predictive models were tested using multiple
regression analyses. In comparing adjusted R2 associated with each of seven
models, it was concluded that needs-based models using subjective indicators
clearly predict more variance in measures of life satisfaction, or subjective
well-being, than do either type of model relying on objective measures. It is
suggested that, in documenting 'outcomes' of rehabilitation, the degree to which
the focal individual's important needs are met defines more directly his/her well
being than do measures of impairment, disability or handicap.
PMID- 10670659
TI - The sensitivity and specificity of self-reported symptoms in individuals with
traumatic brain injury.
AB - In this study, self-reported symptoms (cognitive, physical,
behavioural/affective) from the TIRR Symptom Checklist are compared across six
panels: 135 individuals with mild TBI, 275 with moderate/severe TBI, 287 with no
disability, 104 with spinal cord injury, 197 who are HIV positive and 107 who had
undergone liver transplantation. Participants with TBI and SCI were at least 1
year post-injury. Individuals with TBI reported significantly more symptoms than
other panels. Symptom reports in the TBI panels were independent of demographic
variables (gender, education, income, ethnicity, age), as well as time since
injury and depression. Five of the 67 symptoms were found to be
sensitive/specific to TBI in general; 25 symptoms were sensitive/specific to mild
TBI (23 were cognitive, one physical and one behavioural/affective). Implications
of these results in terms of current debates about the 'reality' of symptom
reports in individuals with mild TBI are discussed, as well as implications for
using symptom checklists for TBI screening.
PMID- 10670660
TI - The unveiling of traumatic brain injury in an HIV/AIDS population.
AB - This study examines the frequency of traumatic brain injury (TBI) in an HIV/AIDS
population and its associated symptomatology. A panel of 173 individuals with HIV
were split into two groups--those who have experienced a blow to the head within
their lifetime (n = 128) and those who have not (n = 45). Self-reported symptoms
from the TIRR Symptom Checklist were compared across both HIV panels, individuals
who identified as traumatically brain injured (n = 416), and individuals with no
disability (n = 282). Six clusters of symptoms (total, cognitive, physical,
affective/behavioural, five symptoms sensitive and specific to TBI in general and
25 symptoms sensitive and specific to mild TBI) were analysed in a MANOVA,
controlling for the demographic variables that were correlated with total
symptoms, including panel membership, education, annual household income and
substance use history. Significant main effects were found for panel membership.
Individuals with HIV and a history of blow to the head reported a higher number
of total symptoms and the 25 symptoms specific to mild TBI. The significance of
these findings acknowledges the need to recognize the frequency of TBI in an HIV
population and the subsequent need to provide the appropriate interventions that
will lead to an enhanced overall quality of life.
PMID- 10670661
TI - Axis II psychopathology in individuals with traumatic brain injury.
AB - PRIMARY OBJECTIVES: To determine the frequency and nature of post-TBI personality
disorders (PDs) in a community-based sample of individuals with TBI. RESEARCH
DESIGN: One hundred individuals with TBI were administered a structural clinical
interview to determine Axis II psychopathology. METHODS OF PROCEDURES: The
Structured Clinical Interview for DSM-IV Personality Disorders, Clinician Version
(SCID II) was used to determine 12 Axis II personality disorders. SCID II
questions were modified so that symptom onset could be rated as occurring pre
injury vs. post-TBI. Data were analysed using student T-tests, chi-square
analysis and one way analyses of variance. OUTCOMES AND RESULTS: Pre-TBI PDs were
diagnosed in 24% of the sample; antisocial PD and obsessive-compulsive PD were
the most common diagnoses. Post-TBI, 66% of the sample met criteria for at least
one PD, with PDs independent of TBI severity, age at injury, and time since
injury. The most common post-TBI PDs were: borderline, avoidant, paranoid,
obsessive-compulsive and narcissistic. Men were more likely to be diagnosed with
antisocial PD and narcissistic PD. Individuals with pre-TBI PDs were at greater
risk of acquiring additional psychopathology post-TBI. Personality traits
endorsed by more than 30% of the sample post-TBI reflected loss of self
confidence, attempts to cope with cognitive and interpersonal failures and
negative affect. CONCLUSION: These findings argue against a specific TBI
personality syndrome, but rather a diversity of personality disorders reflective
of the persistent challenges and compensatory coping strategies developed by
individuals post-TBI. Prospective need for clinical assessment, pro-active
education and focused treatment approaches are discussed.
PMID- 10670662
TI - Predictive validity of the Neurobehavioural Cognitive Status Examination (NCSE)
in a post-acute rehabilitation setting.
AB - Within the context of a post-acute rehabilitation setting, association and
agreement between results from the Neurobehavioural Cognitive Status Examination
(NCSE) and from the neuropsychological (NP) evaluation are examined. All
participants (n = 48) had sustained a severe traumatic brain injury and NCSE
testing preceded NP testing by an average of 1 month. A significant relationship
and fair classification agreement (i.e. presence or absence of cognitive
impairment) was found between the overall results from NCSE and NP evaluation.
Significant relationships were also observed between most NCSE subtests and
paired NP tests thought to be assessing the same cognitive domains. However, the
classification agreement (i.e. the presence or absence of deficient performance)
between most NCSE subtests and paired NP tests was poor. The findings are
discussed from the standpoint of individual treatment planning.
PMID- 10670663
TI - Correlates of depression in adults with severe traumatic brain injury and their
carers.
AB - Although it is generally accepted that social support plays a role in the
maintenance of psychological well-being, there has been relatively little direct
investigation of the role that social support may play in affecting post-injury
depressive symptoms and mediating the effects of traumatic brain injury (TBI).
Consequently, social support was selected as the framework within which to
investigate possible indicators of depression in adults with severe TBI and their
carers. The authors were interested in the degree of association between social
support and the criterion variable of depression in the context of demographic
and disability-related variables that have been identified as significant
correlates of depression. Thirty-five adults with severe TBI (PTA > 7 days) and
their primary carers participated in the study. Time post-injury ranged from 3.5
10 years and all the participants were living in the community. Fifty-seven per
cent of the adults with TBI and 60% of their carers were classified as showing
significant symptoms of depression. As hypothesized, social support contributed
significantly to the prediction of depression. In particular, strong-tie support
appeared to be an important indicator of well-being for both the participants
with TBI and their carers.
PMID- 10670664
TI - Interpretation and comprehension of linguistic humour by adolescents with head
injury: a group analysis.
AB - The aim of the present study was to determine the ability of adolescents with a
head injury to interpret and comprehend linguistic humour. Nine adolescents with
head injury aged between 12 years 1 month and 15 years 4 months, and nine
individually matched adolescents aged between 12 years 1 month and 16 years 1
month were administered a humour test, a standard language battery, the CELF-3,
and the Self-Esteem Index. The test of humour abilities required each subject to
recognize and select an explanation from a group of three, as to what made each
item funny. Items were based on morphological, semantic and syntactic humour
elements. Comparison at a group level demonstrated that adolescents with head
injury performed significantly poorer in the interpretation and comprehension of
linguistic humour than a group of individually matched peers. Contrary to
expectations, a relationship between the level of self-esteem and humour
comprehension did not exist. The findings of the present study suggest that
further research into the effects of head injury on linguistic humour in
adolescents is warranted, particularly from a case-by-case perspective.
PMID- 10670665
TI - Feather pecking in groups of growing bantams in relation to floor litter
substrate and plumage colour.
AB - 1. As part of a programme investigating the causation of pecking damage in fowls,
this experiment tested a proposal that birds may receive more feather pecks when
their plumage colour contrasts with floor litter colour, because litter particles
on plumage (as a consequence of dustbathing) may then have greater stimulus
value. 2. Groups consisting of 7 light- and 7 dark-coloured bantams were reared
from 1 to 11 weeks of age in pens with either wood shavings (light coloured, n=6)
or peat (dark coloured, n=6) floor litter. 3. Feather loss from pecking commenced
in the 3rd week of life and increased thereafter, but observed pecking damage
scores were not consistent with the hypothesis being tested. 4. Despite many more
pecks at birds being seen (over 10 weeks) in the wood shavings groups' (661 at
particles on plumage, 1795 not at particles) than in peat groups (205, 787),
there was no effect of litter substrate on pecking damage. The only evidence
supporting the proposal was the finding that, in groups on wood shavings,
significantly more pecks at particles on plumage were directed from light
coloured birds towards dark ones, than from light to light, dark to light, or
dark to dark. 5. Feather eating was confirmed from the presence of feather
material in 2% to 15% of faecal droppings collected from each group at 11 weeks,
but these proportions were not correlated with pecking damage scores. 6. The
results imply that only some feather pecks/pulls were damaging and only some
eaten feathers were pulled from other birds.
PMID- 10670666
TI - Day length affects feeding behaviour and food intake in adult male emus (Dromaius
novaehollandiae).
AB - 1. In south-western Australia, male and female emus decrease their food intake
when they start breeding in early winter and increase their intake during spring
and summer when the breeding season and egg incubation are finished. 2. This
annual feeding cycle seems to be under the influence of several environmental
factors. Here, we tested the importance of photoperiod using male emus kept in
light-controlled rooms with ad libitum access to food and water. 3. Long days
increased food intake whereas short days decreased it. Emus fed only during the
light hours. 4. Frequency of meals was similar under the 2-day lengths but meal
duration was shorter when the emus were on short days than when they were on long
days. Thus, day length seemed to affect appetite but not interest in food. 5.
Further investigations are needed to test whether these changes in feeding
behaviour are a direct consequence of day length or if they are secondary to
photoperiod-driven changes in sexual activity.
PMID- 10670667
TI - Incidence of pecking damage in growing bantams in relation to food form, group
size, stocking density, dietary tryptophan concentration and dietary protein
source.
AB - 1. This paper reports 4 experiments with groups of 10 to 20 growing bantams in
multi-unit brooders, which investigated effects of certain environmental and
dietary factors on development of feather pecking damage to 6 weeks of age.
Damage was assessed according to a subjective scoring system. 2. A test of food
form (pellets, mash, mash diluted with 100 g/kg powdered cellulose) confirmed
that pecking damage tends to be greater with pellets than with mash but there was
no significant difference between the low damage scores associated with undiluted
and diluted mash treatments. 3. A test of group size (10, 20 birds) and stocking
density (744, 372, 186 cm2/bird) showed that variation in pecking damage was
associated with group size x density interactions. 4. A test of dietary
supplementation with L-tryptophan (0, 10, 20 g/kg) showed suppression of pecking
damage with the higher (20 g/kg) dose, compared with the control (0 g/kg)
treatment. 5. A test of dietary protein source (plant, mainly animal, mainly
semipurified) showed no difference in pecking damage scores between treatments.
PMID- 10670668
TI - Stress-induced oviposition delays in laying hens: duration and consequences for
eggshell quality.
AB - 1. This study investigated relationships between the timing of stress, duration
of oviposition delays and consequences for eggshell quality, in 2 experiments
with ISA Brown hens. 2. Periods of up to 6 h of environmental stress (relocation
from an individual cage to a larger one containing 3 unfamiliar hens), commencing
up to 4.5 h before predicted oviposition time, reliably induced oviposition
delays. Many hens still retained their egg when stress ended. 3. Ovipositions
that occurred during stress were never delayed for more than 3.0 h beyond the
expected time. Ovipositions that occurred after the period of stress ended
usually did so after <1 h if the delay at the end of stress was less than about
2.4 h. Delays that ended either during stress or <2 h after stress ended were
classified as short-term. 4. If an oviposition delay was more than about 2.4 h
when stress ended, the egg concerned was usually laid much later, after a delay
of 7 to 15 h. Delays that ended >5 h after stress ended were classified as long
term. 5. Eggs delayed long-term were white-banded and the subsequent egg was slab
sided, or occasionally soft-shelled. Short-term delays often caused eggshell
dusting with varying amounts of superficial calcification. Hence, duration of
oviposition delay affects both the number of abnormal eggshells and the degree of
abnormality. 6. The present findings are of potential importance to both the egg
industry and breeders, because abnormal eggshells cause downgrading and can
impair embryonic development. Also, numbers of abnormal eggshells and degree of
abnormality can be used as indicators of environmental stress.
PMID- 10670669
TI - Effects of environmental enrichment, fluorescent and intermittent lighting on
injurious pecking amongst male turkey poults.
AB - 1. Under commercial and experimental conditions domestic turkeys often cause
injuries to pen-mates by repeated pecking, sometimes fatally. Environmental
enrichment or lighting manipulations might be used to mitigate such injurious
pecking. 2. This study examined responses to 4 treatments (2 rooms/treatment) of
8 groups of 100, non-beak trimmed, non-desnooded, male domestic turkeys from 1 to
35 d of age. 3. Birds of 1 treatment were reared under conditions approximating
to commercial rearing (12L:12D incandescent, Control) whereas the experimental
treatments were 12L:12D incandescent plus supplemental ultraviolet radiation,
straw supplementation of litter, pecking substrates and visual barriers
(Enriched), 12L:12D fluorescent lighting (Fluorescent), and 2(2L:3D):2L:12D
incandescent (Intermittent). 4. Compared to control birds, the incidence of
injuries caused by wing or tail pecking were both lower in the Enriched but not
significantly different in the Fluorescent or Intermittent. 5. Injuries caused by
head pecking did not occur in the Enriched rooms but were observed in at least 1
of the rooms with Control, Fluorescent and Intermittent treatments. 6. Despite
considerable environmental differences between treatments, there was remarkable
consistency within each type of injurious pecking in age at which injuries were
1st recorded (wing pecking, 9.38+/-1.31 d; tail pecking, 20.43+/-2.42 d; head
pecking, 27.8+/-2.13 d). The roles of feather emergence, hierarchy formation in
wild turkey poults and appearance of feathers are discussed as possible
explanations of these consistencies.
PMID- 10670670
TI - Analysis of risk factors for the occurrence of feather pecking in laying hen
growers.
AB - 1. Potential risk factors for the occurrence of feather pecking in laying hen
growers raised under commercial conditions were investigated on Swiss farms with
more than 500 rearing places. On-farm interviews were conducted on a sample of 64
flocks which represented 42.6% of all farms concerned. 2. All variables
considered were dichotomised and their univariate correlation with the occurrence
of feather pecking was tested for significance at P <0.20 using chi2 tests.
Logistic regression with backward elimination was then used with the significant
variables to identify the potentially most important factors influencing feather
pecking. These variables included stocking density, light intensity, intensity of
care, access to elevated perches, access to a roofed and littered outdoor area
('bad weather run'), time of access to the feeding facilities of the housing
system, stocking density in the restricted area at the beginning of the rearing
period, additional open feeding areas in the beginning and air quality. 3. The
final model contained stocking density and access to elevated perches as
significant factors (P<0.05). Flocks kept in high density (> or = 10 birds per
m2) and with no access to elevated perches were 6.4 (95% Confidence interval 1.7
to 24.2) and 4.0 (95% Confidence interval 1.2 to 12.9) times more likely to be
affected by feather pecking, respectively. 4. The study identified 2 risk factors
for the occurrence of feather pecking in flocks of laying hen growers reared
under commercial conditions. It is concluded that in order to reduce feather
pecking chicks should be reared at low density and with access to elevated
perches.
PMID- 10670671
TI - Heritabilities and genetic correlations of body weights and feather length in
growing Muscovy selected in Taiwan.
AB - 1. Heritabilities and genetic correlations in the base population of a closed
strain of Muscovy duck, moderately selected for body weight at 10 weeks of age,
have been estimated from the data of 9 successive generations for the following
traits: male and female body weight at 10 and 18 weeks of age (BW10m, BW18m,
BW10f, BW18f) and length of the 8th primary feather at 10 weeks of age (F110m,
F110f). 2. Multivariate REML with an animal model was used, pooling data from the
9 generations (3283 and 3289 male and female offspring respectively). The same
trait expressed in male and female was considered as 2 different traits. 3. The
8th primary feather was longer in females than in males by 6% to 22% at 10 weeks
of age. Body weight was heavier in males than in females by 42% to 58% at 10
weeks of age and by 57% to 75% at 18 weeks of age. 3. The heritability estimates
for body weight traits showed moderate values, being a little higher for females
than for males at the same age, increasing with age from h2=0.24 at BW10m to
h2=0.43 at BW18f. 4. The heritability estimates for feather length showed that a
greater response would be obtained in selection for male feather length (h2=0.37)
than for female length (h2=0.14). Both have high genetic correlations with body
weight so they could be indirectly improved. 5. Heritabilities of the difference
in body weights between males and females at 10 weeks (h2=0.07) and 18 weeks of
age (h2=0.10) were small, as well as for feather length (h2=0.10). It would
probably be difficult to modify sexual dimorphism in body weight through
selection. 6. Genetic correlations between BW10m, BW18m and BW10f, BW18f were
respectively r(g)=0.77 and r(g)=0.80. They were larger for body weight at the
same ages between males and females, r(g)=0.90 (r(g)=0.88 between F110m and
F110f). Body weight in males and females at the same age should be better
considered as 2 different traits in a selection programme. 7. The cumulated
predicted genetic gains expressed per unity of the genetic standard deviation
(sigma(g)) over the 8 generations of selection were 1.3 sigma(g) and 1.4 sigma(g)
respectively for the BW10m and BW10f. The predicted correlated responses were 1.2
sigma(g) for body weights at 18 weeks of age, 0.9 sigma(g) and 0.7 sigma(g) for
F110f and F110m respectively.
PMID- 10670672
TI - Haematological and immunological variables in a domesticated and wild subspecies
of ostrich (Struthio camelus).
AB - 1. Domesticated ostriches have been selected rigorously for productive traits
with little concern for immunological responses, in contrast to wild ostriches.
2. We hypothesised that the immunological responses of wild and domesticated
ostriches would differ. Total leucocyte counts, differential counts, heterophil:
lymphocyte ratios, phagocytic activity, lysosome levels and anti-sheep red blood
cell (SRBC) antibody titres (total, IgG, IgM) were compared between domesticated
(n=3) and wild (n=3) ostrich subspecies. 3. Total leucocytes, lymphocytes and
heterophils were similar in the 2 subspecies, but basophils and eosinophils were
lower in the wild than in the domesticated ostriches. Lysosome concentrations and
phagocytic activities were higher in the wild ostriches. 4. Total and IgM
antibody titres to SRBC reached peak values quicker in the domesticated than in
wild ostriches. IgG development patterns were similar. 5. The results suggest
that a stronger non-specific immune response was shown by the wild ostriches
(higher phagocytosis and lysozymes) whereas a stronger specific immune response
was shown by the domesticated ostriches (peak values of anti-SRBC antibody titres
were reached more quickly).
PMID- 10670673
TI - Efficacy of a commercial competitive exclusion product against Campylobacter
jejuni.
AB - 1. Newly-hatched broiler chicks were treated orally with a commercial competitive
exclusion product (Broilact) in 3 replicate trials 2. After 24 h the treated
chicks and untreated control chicks were challenged orally with approximately
10(4) cfu of Campylobacter jejuni. 3. The caeca of the birds were examined
quantitatively for campylobacter 12 d after the challenge. 4. In 3 separate
trials, the treatment prevented or reduced colonisation of the challenge
organisms in the caeca. The percentage of colonised birds varied from 0% to 62%
in the treated groups and was 100% in the control groups. The average number of
campylobacter was considerably lower in the treated groups than in the control
groups.
PMID- 10670674
TI - Tenderness, moisture loss and post-mortem metabolism of broiler Pectoralis muscle
from electrically stimulated and air chilled carcases.
AB - 1. This study was to evaluate the effects of post-mortem electrical stimulation
(ES) on carcase moisture loss and on tenderness, R-value and pH of breast fillets
following air chilling. 2. In each of 4 replications, 8 birds were electrically
stimulated and 12 birds were controls. The ES birds were stimulated at the head
in a 1% saline bath (450 V, 0.45 A, 2 s on/1 s off for 7 pulses). After
evisceration the carcases were air chilled in a cooler at 1 to 2 degrees C with
an average relative humidity of 91% and an air speed of 44 m/min. 3. Breast
fillets were harvested at 2 and 4 h postmortem from both ES and control carcases
and also at 8 h postmortem from control carcases to determine moisture loss pH
and R-value. 4. Although there was no significant effect of ES on shear value at
2 h postmortem, the ES fillets had a lower shear value mean than the control
fillets at 4 h postmortem. There was no significant difference between the shear
value means of the ES 4 h fillets and the control 8 h fillets. 5. ES accelerated
the normal post-mortem decline in pH at both 2 and 4 h postmortem. 6. The R-value
means for the control and ES samples were similar 2 h but the R-value mean of the
ES samples was greater than the control at 4 h postmortem. 7. The results suggest
that, when followed by air chilling, ES accelerates postmortem metabolism,
reduces ageing by up to 50%, and has no effect upon evaporative moisture loss.
PMID- 10670675
TI - Transmission electron microscopy of the vertical crystal layer and cuticle of the
eggshell of the domestic fowl.
AB - 1. Eggshell pieces (1 cm2) were decalcified using a solution of EDTA (200
g/litre, pH 6.9 to 7.0) in paraformaldehyde (2 g/litre) and glutaraldehyde (0.5
g/litre) in phosphate buffer. 2. They were prepared for transmission electron
microscopy (TEM). 3. TEM identified a vertically aligned matrix associated with
the vertical crystal layer (VCL). It is hypothesised that the vertical
orientation of calcite crystals in the VCL is closely linked to this vertical
matrix. 4. TEM also revealed the presence of a 2-layered cuticle, the inner layer
containing vesicles which were absent in the outer. 5. Cuticular vesicles contain
hydroxyapatite and are thought to play a role in the termination of shell
formation. The current paper presents data relating to microbial apatitic systems
that strengthen this hypothesis.
PMID- 10670676
TI - Features of eggshell formation in guinea fowl: kinetics of shell deposition,
uterine protein secretion and uterine histology.
AB - 1. Rate of calcium carbonate deposition, duration of eggshell formation, organic
composition of the uterine fluid, morphology of the egg shells and histochemistry
of the uterus were studied in guinea fowl to analyse the origin of such thick,
strong egg shells. 2. The egg shell was linearly deposited from 6.4 h to 21.8 h
after the oviposition of the previous egg. The rate of egg shell deposition was
similar to that in laying hens. However, the duration of linear shell deposition
was increased by 2.1 h relative to that in hens. This explained the increased egg
shell weight observed in the guinea fowl. 3. Intervals between oviposition of
intra-clutch eggs were 24 h throughout the laying period. Ovulation occurred just
after oviposition of the previous egg in the guinea fowl, as previously observed
in hens but the duration of egg white protein deposition, of plumping and of
initiation of shell mineralisation were all 1.5 h shorter than in domestic hen.
4. Uterine fluid can only be collected during the growth and terminal phase of
shell formation. The electrophoretic profiles of the uterine fluid differed
between phases and were somewhat different from those previously observed in the
hen. Ovalbumin and ovocleidin-17 were both present in the uterine fluid and also
in egg shell extract. Ovocleidin-17 was predominant during the growth phase. 5.
The histology of the uterus differed slightly in guinea fowl compared to hens.
Ovocleidin and ovalbumin are both secreted by the tubular glands. 6. Examination
of radial ultrathin sections of eggshell showed, above the mammillary layer,
intricate interlacing of adjacent exospherite in guinea fowl in contrast to the
continuous columnar microstructure in hens. 7. The kinetics of egg shell
deposition largely explains the increased egg shell weight of guinea fowl. The
organic matrix proteins may be associated with the contrast between the
structural organisation of the guinea fowl egg shell and that of the hen egg
shell.
PMID- 10670677
TI - Composition of vitamin supplements in Spanish poultry diets.
AB - 1. The composition of 106 vitamin supplements used in about 85% of the Spanish
poultry production diets were studied. Vitamin supplements were grouped by
production classes and, for broilers and pullets, also by feeding periods. 2.
Four vitamins (niacin, alpha-tocopherol, pantothenic acid, and riboflavin)
comprised over 87% of the vitamin supplements by weight (choline excluded),
whereas alpha-tocopherol and retinol represented from 51% to 60% of the total
vitamin cost. 3. The highest and lowest vitamin supplementation rates were for
broilers in the starter and withdrawal periods (106 and 44 mg/kg, respectively)
and the mean values for breeders, pullets and layers were 104, 58, and 48 mg/kg,
respectively. 4. Supplements with higher vitamin contents showed less variability
in their composition. Retinol, cholecalciferol, riboflavin and pantothenic acid
showed the lowest variability within supplements (6% to 36% CV), whereas alpha
tocopherol, menadione, thiamin and biotin showed the highest (40% to 224% CV). 5.
Vitamin supplementation rates were compared with requirements, taking into
account the dietary contribution. In general, vitamin fortification exceeded the
NRC recommendations, using a high safety margin for some vitamins such as vitamin
A (from 2.6 to 7.8) and for some poultry classes such as breeders (3.2).
PMID- 10670678
TI - Energy utilisation of carbohydrate, fat and protein sources in newly hatched
broiler chicks.
AB - 1. TME, TMEn and metabolisability (TME/gross energy) of energy-yielding
foodstuffs were determined in 1, 3 and 10 d old broiler chicks, using the assay
method developed by Murakami et al. (1994), in order to characterise energy
utilisation during the 10 d after hatching. 2. TME, TMEn and metabolisability of
dextrin and starch were low in chicks aged 1 d, and increased with age up to 10
d. Energy values of glucose and maltose at days 1 and 3 could not be determined
because of the sudden death of birds soon after the feeding. TMEn and
metabolisability of cereal sources were lower in d-old chicks than in those aged
3 and 10 d. At all ages, maize was better utilised than wheat and sorghum. 3. In
the fat sources (coconut oil, beef tallow and safflower oil) no age dependency
was observed in TME, TMEn and metabolisability. 4. Bioavailability of soyabean
meal and fish meal was lower at 1 d than at 3 d and 10 d. Energy utilisation from
casein was the highest among the protein sources tested and it was not age
dependent. 5. It is concluded that energy utilisation of carbohydrate and protein
sources during 10 d post-hatch tended to increase with age. Among the energy
yielding foodstuffs fat sources seem to be better utilised, with no age
dependency.
PMID- 10670679
TI - Response of broiler chickens to microbial phytase supplementation as influenced
by dietary phytic acid and non-phytate phosphorus contents. I. Effects on bird
performance and toe ash.
AB - 1. Seven-day old male broilers (n=900) were fed on wheat-sorghum-soyabean meal
based diets containing 3 concentrations of phytic acid (10.4, 13.2 and 15.7 g/kg;
equivalent to 2.9, 3.7 and 4.4 g/kg phytate phosphorus), 2 of non-phytate
phosphorus (2.3 and 4.5 g/kg) and 3 of microbial phytase (Natuphos 5000 L; 0, 400
and 800 FTU/kg) in a 19-d trial. The dietary phytic acid contents were
manipulated by the inclusion of rice pollard. 2. Each dietary treatment was fed
to 5 pens (10 birds/pen) from 7 to 25 d of age. Records of body weight, food
intake and mortality were maintained. On d 25, all surviving birds were killed
and toe samples were obtained for toe ash measurements. 3. Increasing dietary
phytic acid negatively influenced body weight gain, food intake and food/gain.
These adverse effects were partially overcome by the addition of microbial
phytase. 4. Supplemental phytase caused improvements in weight gain and food
efficiency of broilers but the magnitude of the responses was greater in low non
phytate phosphorus diets, resulting in significant non-phytate phosphorus x
phytase interactions. 5. Toe ash contents were improved by phytase addition but
the response was greater at the highest concentration of phytic acid, resulting
in a significant phytic acid x phytase interaction. Responses were also greater
in low non-phytate phosphorus diets as indicated by significant non-phytate
phosphorus x phytase interaction. 6. In general, there was very little difference
in the responses to phytase additions at 400 and 800 FTU/kg. 7. The performance
responses to added phytase in birds receiving adequate non-phytate phosphorus
diets provide evidence for the influence of the enzyme on animal performance
independent of its effect on phosphorus availability.
PMID- 10670680
TI - Optimum inclusion of field peas, faba beans, chick peas and sweet lupins in
poultry diets. I. Chemical composition and layer experiments.
AB - 1. Experiments were undertaken to determine the chemical composition and apparent
metabolisable energy (AME) of field peas, faba beans, sweet lupins and chick peas
and the production of hens when each was included in nutritionally similar diets
at 250 g/kg in 2 experiments. 2. Amino acid composition, crude protein and AME
agreed well with previously published measurements. Detailed analysis of the non
starch polysaccharides (NSPs) showed that sweet lupins were much higher than the
other grain legumes in the soluble NSPs and that the NSPs were particularly high
in arabinose. The condensed tannin content was highest in field peas followed by
faba beans. 3. In the 1st layer experiment over 40 weeks, hen-day egg production
was lowest on the faba bean-based diet and egg weight and egg mass were also
lowest. Relative viscosity of digesta in the small intestine of hens fed on the
sweet lupin-based diet was highest, followed by that of hens fed on field peas.
Enlargement of the pancreas was observed in hens consuming chick peas. 4. In
experiment 2, in which only sweet lupins and faba beans were used, steam or cold
pelleting showed few effects, nor did dehulling of faba beans but egg weight was
lower when diets were steam pelleted. Daily food intake was 5.7 g/bird lower on
the steam than cold pelleted diets and food conversion ratio tended to be
improved (P=0.082). 5. It was concluded that field peas could support good
production at 250 g/kg of layer diet. Although chick peas and sweet lupins
supported good performance, there was concern about the increased weight of the
pancreas and high gut viscosity respectively. Faba beans showed similar hen-d egg
production in the 2nd experiment to that of sweet lupins but egg weight tended to
be about 0.8 g lower than when on the sweet lupin-based diets.
PMID- 10670681
TI - Optimum inclusion of field peas, faba beans, chick peas and sweet lupins in
poultry diets. II. Broiler experiments.
AB - 1. Three experiments were undertaken to determine the optimum inclusion rates of
field peas, faba beans, chick peas and sweet lupins in broiler starter and
finisher diets in amounts up to 360 g/kg. 2. In experiment A chickens in cages
grown to 21 d on diets with field peas and faba beans gave better growth rate and
feed efficiency than those with sweet lupins and chick peas. Growth rate and Food
conversion ratio (FCR) improved with increasing amounts of faba beans in the diet
while for chick peas growth rate and FCR declined. Digesta viscosity and excreta
stickiness scores were much higher on diets with sweet lupins. Steam pelleting
improved growth rate and FCR on all diets. 3. In experiment B birds were in cages
and grown from 21 to 42 d. There were no differences between grain legumes (when
combined for all inclusions) for growth rate, food intake or FCR. Viscosity was
again much higher on the sweet lupin-based diets while the pancreas was
significantly enlarged on the diets with chick peas, as observed previously in
chickens grown to 21 d. Steam pelleting of diets gave a consistent and positive
response for weight gain and FCR. 4. Experiment C was carried out in pens each
holding 60 birds under semi-commercial conditions and grown to 42 d on starter
and finisher diets with the same grain legumes as used previously but each at 2
rates of inclusion similar to those in commercial practice. Field peas at 200 to
300 g/kg and chick peas at 150 to 220 g/kg gave inferior growth to faba beans
(150 to 180 g/kg) and sweet lupins (120 g/kg). 5. The results of these
experiments allowed tentative recommendations to be made to industry for
inclusion rates of these cultivars of the 4 grain legumes. These were: field peas
300 g/kg; faba beans 200 g/kg, chick peas 100 g/kg and sweet lupins <100 g/kg.
Wet droppings and high gut viscosity were serious problems with sweet lupins
although these were not so obvious in experiment C.
PMID- 10670682
TI - Influence of dietary energy, supplemental fat and linoleic acid concentration on
performance of laying hens at two ages.
AB - 1. The aim of this study was to investigate the influence of metabolisable energy
(ME), supplemental fat (SFAT) and linoleic acid (LIN) content of the diet on the
productive performance and weight of eggs and egg components of Isabrown hens of
22 or 74 weeks of age. 2. Six diets were formulated to contain the following
concentrations of ME (MJ/kg), SFAT (g/kg) and LIN (g/kg), respectively: A) 11.8,
0 and 11.5; B) 11.8, 40 and 11.5; C) 11.8, 40 and 16.5; D) 11.2, 40 and 16.5; E)
11.2, 40 and 11.5; and F) 11.2, 0 and 11.5. Data were collected for 28 d and
analysed using linear contrasts to test the effect of SFAT, LIN, ME and their
interactions. 3. When the LIN content of the diets was maintained constant at
11.5 g/kg, an increase in the SFAT from 0 to 40 g/kg increased egg weight (63.8
vs 64.5 g; P<0.05), food intake (119 vs 124 g; P<0.01) and energy intake (1.36
vs. 1.42 MJ/d; P<0.01) and body weight change of the hens (-85 vs. 27 g;
P<0.001). Supplemental fat also increased yolk (15.8 vs. 16.3 g; P<0.001) and
albumen weight (40.8 vs. 42.3 g; P<0.01) but yolk to albumen ratio was not
modified. 4. Egg and albumen weights were improved by SFAT in early but not in
late producing hens. As a result, yolk to albumen ratio decreased in the younger
hens, from 0.371 to 0.357, but increased in the older hens, from 0.408 to 0.415;
P<0.01) with fat addition. 5. An increase in the LIN content of the diets from
11.5 to 16.5 g/kg did not modify any of the traits studied. 6. It was concluded
that the LIN requirement of the hens for maximal productivity and weight of eggs
is 11.5 g/kg or less. Supplemental fat increased the weight of eggs and albumen
in the younger but not in older hens and the beneficial effect was independent of
its LIN content.
PMID- 10670683
TI - Effect of dietary methionine on performance, carcase characteristics and breast
meat composition of heterozygous naked neck (Na/na+) birds under spring and
summer conditions.
AB - 1. Heterozygous naked neck (Na/na+) birds and their normally feathered
counterparts (na+/na+) were fed from 0 to 7 weeks on 3 diets differing in
methionine concentrations. From 0 to 3 and 3 to 7 weeks, respectively, the
concentrations were: low containing 4.3 and 3.3 g/kg; optimum containing 5.0 and
3.8 g/kg and; high with 5.7 and 4.4 g/kg under spring (optimum ambient
temperature) and summer conditions (high ambient temperature). Performance,
carcase characteristics and breast meat chemical composition were determined. 2.
Summer rearing resulted in a decrease in body weight, body weight gain, food
consumption, and yields of carcase and breast. The summer temperature effect was
more pronounced in males. Under summer temperatures, the protein content of the
breast decreased while the fat content increased compared to birds reared in
spring. 3. By 7 weeks of age, both genotypes reached similar body weights in the
spring experiment while, in summer Na/na+ birds were 3.3% heavier and gained more
in the period from 3 to 7 weeks than na+/na+ birds. Carcase and breast yields of
Na/na+ birds were greater than in na+/na+ birds. 3. Second order polynomial
coefficients of the dietary methionine effect were found to be significant for
body weight at 3 and 7 weeks. Daily body weight gain between 3 and 7 weeks was
linearly affected by the dietary methionine concentration. There was no
interaction between genotype and methionine. 4. Methionine had no significant
effect on carcase yield. Second order polynomial coefficients of the dietary
methionine effect were found to be significant for breast yield while the
methionine effect on abdominal fat was linear. Na/na+ females fed on the low
methionine diet had lower protein content than the Na/na+ males. 5. It is
concluded that the methionine requirement of Na/na+ birds did not differ from
that of their normally feathered counterparts under either spring or summer
ambient temperature conditions.
PMID- 10670684
TI - Effect of dried tomato pulp on the performance and egg traits of laying hens.
AB - 1. Grouped laying hens were fed on experimental diets containing dried tomato
pulp (DTP) at inclusion rates up to 120 g/kg and two control diets (A and
A+Carophyll). 2. The addition of DTP did not significantly affect egg production,
food consumption and efficiency, egg weight and shell thickness. 3. There was a
significant improvement in the egg yolk colour in treatments containing DTP.
However, this improvement was significantly lower in comparison to the diet which
contained carophyll.
PMID- 10670685
TI - Intracerebroventricular injection of orexins does not stimulate food intake in
neonatal chicks.
AB - 1. Recently, 2 novel neuropeptides were discovered, both derived from the same
precursor by proteolytic processing, which bind and activate 2 closely related
orphan G protein-coupled receptors, Named orexin-A and -B (Sakurai et al., 1998).
Both stimulate food intake when administered centrally to rats. 2. Our aim was to
elucidate whether central injection of mammalian orexin-A or -B stimulates food
intake in the chick. 3. Under conditions of free access to food, orexin-A did not
alter the food intake of chicks, but cumulative food intake was significantly
suppressed by orexin-B. 4. The orexin-B was then administered to chicks deprived
of food for 3 h to confirm its suppressive effect. No significant effect of
orexin-B on food intake was detected. 5. Central injection of orexin-B did not
modify food intake when appetite was stimulated by fasting. 6. Neither of these
orexins appears to stimulate feeding in chicks.
PMID- 10670686
TI - Persistent hypoglycemia induced by continuous insulin infusion in broiler
chickens.
AB - 1. Persistent hypoglycaemia was experimentally induced by insulin infusion to
improve understanding of the regulatory mechanisms of blood glucose
concentrations specific to chickens. 2. An osmotic minipump containing bovine
insulin was implanted to deliver insulin in vivo at a constant rate (11.25 to 45
U/kg BW/d) for 5 d in 4-week-old broiler chickens force-fed a maintenance diet
once a d. Birds infused with the highest dose of insulin died within 3 to 4 d. 3.
In chickens continuously infused with insulin at 22.5 U/kg BW/d, fasting glucose
concentrations in plasma determined every 3 h during the 3rd day of infusion were
consistently and significantly lower than in controls. 4. Continuous infusion of
insulin at 22.5 U/kg BW/d induced persistent hypoglycaemia (almost one-half the
normal blood glucose concentration) lasting for at least 4 d in broiler chickens.
5. Insulin infusion did not significantly change plasma NEFA or protein
concentrations and increased plasma GOT activity only at 1 of the daily
experimental sampling points.
PMID- 10670687
TI - Production and physical characteristics of composted poultry carcases.
AB - 1. Experiments were designed to determine whether composting could be a safe and
effective method for the disposal of poultry carcases in the UK climate. Laying
hen carcases (125) were composted in a wooden compost bin over autumn and winter
months, using the United States Department of Agriculture method. 2. The process
took 8 weeks and effectively decomposed the carcases to leave only leg and breast
bones. The compost was turned once, which ensured that all the material reached
the high temperatures (60 degrees to 70 degrees C) required to control pathogens.
Salmonella was fully heat-inactivated, indicating that many poultry-associated
bacterial pathogens would also have been inactivated. 3. It is concluded that
this method is suitable for use in the UK and provides a sanitised fertiliser
supplement.
PMID- 10670689
TI - Effects of altering dietary fatty acid composition on prostaglandin synthesis and
fertility.
AB - Several studies over the past 20 years have demonstrated that subjects on diets
composed of substances with high levels of n-3 polyunsaturated fatty acids
(PUFAs) (e.g. fish) have a decreased incidence of heart disease. On this basis, a
recent report from the Department of Health has advised UK consumers to decrease
the proportion of saturated as opposed to unsaturated fats in their diet and to
increase the ratio of n-3 to n-6 PUFAs. This could be achieved by altering the
amounts of these constituents in milk and meat. n-3 Fatty acids can most easily
be added to animal feed as either fish oil or linseed oil and can be increased in
the blood and milk of ruminants following protection to avoid hydrogenation in
the rumen. In western countries the ratio of consumption of n-6 to n-3 PUFAs is
greater than 10 and current evidence tends to suggest that a ratio nearer 5 would
be more desirable and compatible with cardiovascular well being. As fertility in
the UK dairy herd is already poor, it is important to establish whether
alterations in dietary n-3 and n-6 PUFAs affects herd fertility before widespread
changes in animal diets are recommended. Therefore, this review considers the
role played by PUFAs and eicosanoids in fertility, with particular reference to
the implications for farm livestock production. The evidence reviewed shows that
alteration of the concentration and ratio of n-6 and n-3 PUFAs in feeds can
influence prostaglandin synthesis/metabolism in a number of mammalian systems.
The changed patterns of prostaglandin synthesis can as a consequence, affect the
diverse functions (e.g. hormone secretion) that are normally mediated via
prostaglandins. Similarly, changes in prostaglandin synthesis effected through
manipulation of PUFAs has a major bearing on fertility (as PGs affect many
reproductive parameters, e.g. ovulation). Several studies in cattle and other
mammals, show that feeding or infusing different types of fat with varying PUFA
content to females can alter: the number and size of ovarian follicles, the
ovulation rate, progesterone production by the corpus luteum, the timing of
luteolysis and gestational length. In the male most recent work has focussed on
sperm production and experiments in fowl have demonstrated clear effects of
dietary PUFAs on both the sperm membrane phospholipid composition and on
fertilizing ability.
PMID- 10670688
TI - Sphingolipids stimulate cell growth via MAP kinase activation in osteoblastic
cells.
AB - Ceramide, ceramide-1-phosphate (C1P) sphingosine (SPH) and sphingosine-1
phosphate (S1P) effects on proliferation and extracellular-signal regulated
kinases, ERKs (also known as MAPKs), activation were investigated in human and
rat osteoblastic cells. MAPK activation was sphingolipid-specific in cells from
both species. In human osteoblastic cells, S1P and C1P markedly stimulated ERK2
phosphorylation with a slight increase in phosphorylation of ERK1. SPH nor
ceramide induced phosphorylation of either ERK isoform. In rat osteoblastic
cells, SIP, ceramide and SPH stimulated phosphorylation of both isoforms. C1P did
not induce phosphorylation of ERK1 but produced a mild increase in
phosphorylation of ERK2. In human cells, only S1P significantly (P<0.05)
increased osteoblastic cell proliferation, while in the rat cells all four
sphingolipids significantly (P<0.05) induced proliferation. The calcium channel
blocker verapamil blocked (P<0.05) these effects in both cell types. The MAPK
inhibitor, PD98059, inhibited (P<0.05) the mitogenic effect of SIP in human
cells. In rat cells, PD98059 effects were less substantial but significant for
S1P and C1P. This study demonstrates that sphingolipids are mitogens for both
human and rat osteoblastic cells with the MAPK pathway and calcium mediating in
part these effects in a species specific manner.
PMID- 10670690
TI - The effects of a diet rich in docosahexaenoic acid on organ and vascular fatty
acid composition in spontaneously hypertensive rats.
AB - Previous research has shown that dietary docosahexaenoic acid (DHA) attenuates
the development of high blood pressure in young spontaneously hypertensive rats
(SHR). The purpose of this study was to investigate the effects of dietary DHA on
organ and vascular fatty acid composition in SHR. Given the important structural
and functional role of fatty acids in cell membranes, alterations in fatty acid
composition may contribute to the antihypertensive effect of DHA. SHR were fed a
purified diet containing either a corn/soybean oil mixture (CSO, control) or a
DHA-enriched oil for 6 weeks. The DHA diet markedly increased the levels of DHA
in the aorta, renal artery, plasma, liver, heart, kidney, and lung by 5-, 15-, 7
, 6-, 3.8-, 3.5-, and 8.8-fold (P<0.001), respectively. The levels of
eicosapentaenoic acid were also increased while there was a concomitant reduction
in arachidonic and adrenic acids. Therefore, dietary DHA increases the
incorporation of omega-3 polyunsaturated fatty acids in specific organs and
vascular tissue in SHR at the expense of omega-6 polyunsaturated fatty acids.
PMID- 10670691
TI - A comparison of the effects of indomethacin and NS-398 (a selective prostaglandin
H synthase-2 inhibitor) on implantation in the rat.
AB - Indomethacin (25 microM) inhibited the amount of prostaglandin (PG) E2, PGF2alpha
and 6-keto-PGF1alpha synthesized by homogenates of day 5 pregnant rat uterus by
80-92%. In contrast, 25 microM NS-398, a selective inhibitor of prostaglandin H
synthase-2 (PGHS-2), inhibited the synthesis of these three prostaglandins by
homogenates of the same tissue by only 37-60%. Since it has been reported that
idomethacin and NS-398 inhibit PGHS-2 with similar potencies and that
indomethacin (unlike NS-398) is a potent inhibitor of PGHS-1, it may be concluded
that prostaglandin production by homogenates of the rat uterus on day 5 of
pregnancy is due to the activities of both PGHS-1 and PGHS-2. The administration
of indomethacin (3 mg/kg) twice daily on days 3 and 4 of pregnancy reduced the
implantation rate by 77%, whereas the similar administration of NS-398 (6 mg/kg)
had no significant effect on implantation. It may be concluded that either the
dose of NS-398 used was too low to affect uterine PGHS-2 activity in vivo
sufficiently to prevent implantation, or that inhibiting uterine PGHS-2 activity
in vivo has no effect on the implantation mechanisms or is compensated for by
increased PGHS-1 activity such that the implantation process is not impaired.
PMID- 10670692
TI - Effects of prostaglandin E1 on high density lipoprotein-phospholipid composition.
AB - Serum high-density phospholipids (HDL-phospholipids) composition was determined
in rats treated with prostaglandin E1 (PGE1) and control group treated with
isotonic saline. Total phospholipids and HDL-phospholipids levels at serum were
found lower in rats treated with PGE1, than in controls. Considering the
individual phospholipid classes of HDL, we observed that phosphatidylocholine
(PC), phosphatidylinositol (PI) and diphosphatidylglycerol (DPG) serum
concentrations were significantly higher in treated rats than in controls
(P<0.001, P<0.005 and P<0.05 respectively). Furthermore, the serum concentrations
of lysophosphatidylocholine (LPC) and phosphatidylserine (PS) were significantly
lower in treated rats than in controls (P<0.01 and P<0.001 respectively). These
findings suggest that PGE1 influences the composition of HDL-phospholipids and
possibly modifies their action on lipid metabolism.
PMID- 10670693
TI - Prostaglandins and cyclic nucleotides in the urinary bladder of a rabbit model of
partial bladder outlet obstruction.
AB - Bladder outlet obstruction (BOO) is a common disorder that is associated with
altered bladder structure and function. For example, it is well established that
BOO results in hypertrophy and hyperplasia of the bladder smooth muscle as well
as detrusor instability. Since prostaglandins (PGs) and cyclic nucleotides
(cyclic AMP [cAMP] and cyclic GMP [cGMP]) mediate both smooth muscle tone and
proliferation, it is reasonable to suggest that changes in their levels may be
involved in the pathophysiology of BOO-associated bladder disorders. Hence, the
objective of this study was to investigate cyclic AMP, cyclic GMP and
prostaglandins in the bladder of a rabbit model of BOO. BOO was induced in adult
male New Zealand White rabbits. After 3 weeks, urinary bladders were excised,
weighed and cut into segments. They were then incubated with stimulators of PGs,
cAMP and cGMP and the formation of PGs, cAMP and cGMP were measured using
radioimmunoassays. There was a significant increase in the obstructed bladder
weights (P=0.002). The formation of PGE2, PGI2, cAMP and cGMP was significantly
diminished in the detrusor (P<0.05) and bladder neck (P<0.05) in the BOO bladders
compared to age-matched controls. Since PGE2, PGI2, cAMP and cGMP are known to
inhibit the proliferation of smooth muscle cells (SMCs), the decreased synthesis
of these factors, in BOO, may play a role in bladder SMC hypertrophy/hyperplasia.
Our study points to the possible use of drugs that modulate the NO-cGMP and/or PG
cAMP axes in BOO-associated bladder pathology.
PMID- 10670694
TI - Involvement of cyclooxygenase-2 in proliferation and morphogenesis induced by
transforming growth factor alpha in gastric epithelial cells.
AB - Transforming growth factor alpha is one of the most potent growth factors for
gastrointestinal epithelium. In this study, we examined the roles of
cyclooxygenase-2 on proliferation and morphogenesis of RGM1 rat gastric
epithelial cells after stimulation with transforming growth factor alpha in
vitro, RGM1 cells increased expression of cyclooxygenase-2 messenger RNA 20-60
min after stimulation with transforming growth factor alpha. Transforming growth
factor alpha stimulated [3H]thymidine incorporation and tubulogenesis of RGM1
cells in collagen matrix, both of which were significantly suppressed by
treatment with a cyclooxygenase-2 specific inhibitor, NS-398 or cyclooxygenase-2
antisense oligonucleotide. Both of the treatment lowered prostanoid production by
enzyme immunoassay. The transforming growth factor alpha-induced expression of
cyclooxygenase-2 is followed by cell proliferation and development of tubular
morphology of RGM1 gastric epithelial cells. Treatment with cyclooxygenase-2
inhibitor and cyclooxygenase-2 antisense oligonucleotide suppressed these
responses induced by transforming growth factor alpha suggesting the involvement
of cyclooxygenase-2 in proliferation and morphogenesis in gastric mucosal
epithelium.
PMID- 10670695
TI - Cytokines regulate prostaglandin H synthase-1 transcription in human amnion
derived cells.
AB - We have isolated the prostaglandin H synthase-1 (PGHS-1) promoter from the human
amnion cell line WISH by long template PCR. The fragment was 1124 base pairs in
length and shared a 96% sequence identity with the sequence in GenBank. The
putative transcription start site is located 18 bp upstream of the start codon.
The sequence is TATA-less, but contains multiple Sp-1 sites and a GC box at -132.
The fragment was subcloned into the promoterless reporter construct pBLCAT3 to
produce the promoter reporter construct pPGHS1CAT. pPGHS1CAT expression in amnion
derived AV3 cells was inhibited by the pro-inflammatory cytokines tumor necrosis
factor-alpha (TNF-alpha) and interleukin 1-beta (IL-1beta). PGHS-1 mRNA levels
however, were unchanged over a 16-h time course with either treatment. These
results suggest that PGHS-1 transcription is regulated in a negative manner by
cytokines in human amnion-derived cells.
PMID- 10670696
TI - Cytotoxicity of combined essential fatty acids on a human prostate cancer cell
line.
AB - In this study the effect of single and concomitantly added n-6 or n-3
polyunsaturated fatty acids (PUFAs) was investigated on human prostate cells.
Data obtained from the single fatty acids (FAs) experiments showed that except
for oleic acid (OA), arachidonic (AA) and linoleic acid (LA), which had very
little (less than 10% cells dead) effect on the cells, an increase in dead cells
was observed at physiological concentrations of, eicosapentaenoic acid (EPA),
gamma-linolenic acid (GLA) and alpha-linolenic acid (ALA). However, this was not
the case when combining these acids at physiological concentrations. A slight
increase in cell death was only obtained with three combinations of ALA, namely
with AA, OA, or GLA. Other combinations with ALA, such as with LA or EPA, had
respectively no effect on cell number or increased the cell number by causing
less cells to die. Other PUFAs combinations tested, did not show the three groups
mentioned with ALA, but only the last two types, namely, no effect, or a decrease
in the amount of cell death. The latter might mean that the FA combination had
stimulated the cells, since a decrease in the amount of dead cells was observed.
Therefore, it is concluded that the characteristics of combined FAs may differ
from single FAs, which may explain some controversies in the literature and in
response to treatments.
PMID- 10670697
TI - Disease patterns in field and bank vole populations during a cyclic decline in
central Finland.
AB - Declining field vole (Microtus agrestis) and bank vole (Clethrionomys glareolus)
populations were sampled (117 field voles and 34 bank voles) in south-central
Finland during the winter of 1988-89. The last surviving field voles were caught
in April and bank voles in February. A subsample (16) of the April field voles
were taken live to the laboratory for immunosuppression. The histopathology of
the main internal organs and the presence of aerobic bacteria and certain
parasites were studied. In the lungs, an increase in lymphoid tissue, probably
caused by infections, was the most common finding (52% of all individuals). The
prevalences in the voles, in the whole material, of Chrysosporium sp. and
Pneumocystis carinii in lungs were 13 and 10% in field voles, and 9 and 0% in
bank voles, respectively. Cysts of Taenia mustelae (9 and 27%) were the most
common pathological changes in the liver. Enteritis was also rather common (14
and 34%). In field voles the prevalences of Frenkelia sp. in the brain and
Sarcocystis sp. in leg muscles were low (both 6%). Bordetella bronchiseptica was
commonly (31%) isolated from field vole lungs and Listeria monocytogenes from the
intestines (34%). Salmonella spp. could not be found. The dynamics and abundance
of inflammations in the lungs and intestines, as well as B. bronchiseptica
isolations from the lungs, indicate that obvious epidemics took place in
declining vole populations. Of the Luhanka subsample of 16 field voles brought to
the laboratory in April, one died of listeriosis, two of Bordetella, and five
died for unknown reasons. Even if small mustelids are the driving force in
microtine cycles, it is possible that diseases also contribute to the decline.
PMID- 10670698
TI - Natural killer activity in mice infected with rabies virus and submitted to P.
acnes (Propionibacterium acnes) as immunomodulator.
AB - The natural killer (NK) activity and lethality were evaluated in swiss mice
experimentally infected with street rabies virus and submitted to
immunomodulation by P. acnes (formerly Corynebacterium parvum). The infected
animals were sacrificed at different times and spleen non-adherent cells were
obtained through ficoll-hypaque gradient and depletion of glass-adherent cells.
Immunosuppression was observed in rabies virus infected mice correlated with
lower NK activity in clinically ill animals. Higher NK activity and percentual of
survival were observed in the group submitted to P. acnes. The increased survival
correlated with higher NK activity induced by P. acnes suggests a protective role
of this natural barrier against rabies virus infection in mice.
PMID- 10670699
TI - Identification and localization of a schistosome-associated fucosyllactose
determinant expressed by Fasciola hepatica.
AB - A Biomphalaria alexandrina-derived lectin (BaSII), of proven specificity to a
Schistosoma mansoni-associated fucosyllactose [(Fuc alpha1-2) Gal beta1-4 Glc]
determinant, was employed to investigate the putative antigenic cross-reactivity
between Schistosoma mansoni and Fasciola hepatica in terms of this structurally
defined oligosaccharide sequence. BaSII affinity column chromatography of
extracts of adult worms metabolically radiolabelled with 35S-methionine and
analysis by two-dimensional gels established the expression of the fucosyllactose
determinant in multiple copies among heterogeneous, acidic glycoproteins
synthesized by adult Fasciola hepatica. Direct fluorescence microscopy revealed
that determinant-bearing glycoproteins were localized to the external glycocalyx
and perikarya of the tegument as well as the epithelial lining of the intestinal
caeca and vitelline ducts and glands. Determinant expression was also evident in
embryonated cells of eggs and miracidia as well as the intermediate cellular wall
of encysted metacercariae, suggesting its conservation during the course of
development of the parasite. Based on the structural relatedness of the cross
reactive fucosyllactose determinant to the antigenic mammalian blood group H
trisaccharide, our observations may have implications in serodiagnosis and
immunoprophylaxis of schistosomiasis/fascioliasis.
PMID- 10670700
TI - Identification of a collectin-like protein in pig serum that binds a component in
perienteric fluid from Ascaris suum.
AB - A collectin-like protein (CLP) of the acute phase protein family that binds the
polysaccharides mannan and alpha-1-6 dextran was isolated from the serum of pigs
infected with Ascaris suum. A monoclonal antibody generated against this protein
and used to characterize the CLP revealed on SDS-PAGE and western blot analysis
that the protein had a molecular weight of approximately 48 kDa under reducing
conditions and greater than 100 kDa under nonreducing conditions. Enzyme-linked
immunosorbent assay (ELISA) showed that the CLP bound to substances in the
perienteric fluid of Ascaris suum (APF). Molecular weight fractionation of APF
demonstrated that CLP binds primarily to APF substances of greater than 100 kDa.
Binding of CLP to APF was partially blocked by phosphatidylinositol. This is the
first report of a porcine CLP and the binding of a CLP to components of the
common nematode Ascaris suum.
PMID- 10670701
TI - Human contact with cattle, dogs and monkeys and genetic diversity of measles
viruses.
AB - There is a very close contact among humans, cattle, dogs and monkeys in
developing countries. That could lead to genetic alteration in morbillivirus
isolates of measles, rinderpest, canine distemper. Emergence of novel
morbillivirus strains and failures of prophylactic viral vaccines should be
monitored by characterisation of genetic profiles of isolates in different
species. Incorporation of additional epitopes in existing prophylactic vaccines
should minimise vaccine failures attributable to such novel strains.
PMID- 10670702
TI - Selenium and vitamin E effect on antibody production of sheep vaccinated against
enzootic abortion (Chlamydia psittaci).
AB - The effect of selenium (Se) and vitamin E (vit E) on antibody production of sheep
vaccinated against Chlamydia psittaci (ovis) was investigated. Thirty-two sheep,
one year old, seronegative to Chlamydia infection, vaccinated against
enterotoxemia and dewormed were used. Injectable sodium selenite (0.1 mg/kg b.w.)
was given twice to animals of the first group (gSe), with a three week interval.
The sheep of the second group (gE) received 1 g vit E each orally, six times at
weekly intervals. The animals of the third group (gSeE) were given Se and vit E
in doses and routes of administration as in gSe and gE. The animals of the fourth
group served as controls (gC) and injected normal saline. The first vaccination
was made at the time that the second Se injection was given. Revaccination was
made two weeks later. The experiment lasted 29 weeks. The results indicated that
Se alone led to a significant increase of Chlamydia antibody response (P < 0.05),
but not when it was given in combination with vit E. Animals that received vit E
(gE) had much lower titres, just above of those of the controls.
PMID- 10670703
TI - Anxiolytic 2,3-benzodiazepines, their specific binding to the basal ganglia.
AB - Over the past 20 years, several members of the 2,3-benzodiazepine family have
been synthesized. Some of these compounds--tofisopam (Grandaxin), girisopam,
nerisopam--exert significant anxiolytic and antipsychotic activities. Sites where
actions of 2,3-benzodiazepines are mediated differ from those of 1,4
benzodiazepines. Binding of 2,3-benzodiazepines to neuronal cells in the central
nervous system shows a unique and specific distribution pattern: their binding
sites are located exclusively to the basal ganglia. Chemical lesioning of the
striato-pallido-nigral system, surgical transections of the striato nigral
pathway and the activation of c-fos expression in the basal ganglia after
application of 2,3-benzodiazepines suggest that these compounds mainly bind to
projecting neurons of the striatum. The binding sites are transported from the
striatum to the substantia nigra and the entopeduncular nucleus. Recent studies
on mechanism of action of 2,3-benzodiazepines indicate their possible role in
opioid signal transduction since 2,3-benzodiazepines augment the agonist potency
of morphine to induce catalepsy and analgesia, and their action is diminished in
morphine tolerant animals. The possible biochemical target of 2,3-benzodiazepines
is an alteration in the phosphorylation of protein(s) important in the signal
transduction process. Agents affecting emotional responses evoked by endogenous
opioids without danger of tolerance and dependence may represent a new
therapeutic tool in the treatment of addiction and affective disorders.
PMID- 10670704
TI - Ethanol and amino acids in the central nervous system: assessment of the
pharmacological actions of acamprosate.
AB - Ethanol induces alterations in the central nervous system by differentially
interfering with a number of neurotransmitter systems, although the mechanisms by
which such effects are executed are not well understood. The present review
therefore, is designed to ascertain the effect of ethanol on both excitatory and
inhibitory amino acid neurotransmitters, as well as the sulphonated amino acid
taurine, assayed by the microdialysis technique within specific brain regions of
rat during different types of alcohol intoxication, acute and chronic, as well as
during the withdrawal period. Such an understanding of these pharmacological
actions of ethanol on neurotransmitters is essential in order to provide the
impetus for the development of appropriate therapeutic intervention to ameliorate
the multitude of neurochemical disorders induced by ethanol. In addition the
possible mode of action of a new therapeutic drug for the treatment of
alcoholism, acamprosate will be discussed. The first part of this review will be
limited to studies of the effect of ethanol on both amino acid neurotransmitters
and the sulphonated amino acid taurine, a possible neuromodulator. While, the
second part will seek to establish the possible mechanism of action of a new
therapeutic drug, acamprosate, which is used to combat the effects of ethanol,
particularly during the craving period, as well as maintaining abstinence in
weaned alcoholics.
PMID- 10670705
TI - Presenilins and Alzheimer's disease: biological functions and pathogenic
mechanisms.
AB - Alzheimer's disease (AD) is the most common cause of dementia in the elderly
population. Dementia is associated with massive accumulation of fibrillary
aggregates in various cortical and subcortical regions of the brain. These
aggregates appear intracellularly as neurofibrillary tangles, extracellularly as
amyloid plaques and perivascular amyloid in cerebral blood vessels. The causative
factors in AD etiology implicate both, genetic and environmental factors. The
large majority of early-onset familial Alzheimer's disease (FAD) cases are linked
to mutations in the genes coding for presenilin 1 (PS1) and presenilin 2 (PS2).
The corresponding proteins are 467 (PS1) and 448 (PS2) amino-acids long,
respectively. Both are membrane proteins with multiple transmembrane regions.
Presenilins show a high degree of conservation between species and a presenilin
homologue with definite conservation of the hydrophobic structure has been
identified even in the plant Arabidopsis thaliana. More than 50 missense
mutations in PS1 and two missense mutations in PS2 were identified which are
causative for FAD. PS mutations lead to the same functional consequence as
mutations on amyloid precursor protein (APP), altering the processing of APP
towards the release of the more amyloidogenic form 1-42 of Abeta (Abeta42). In
this regard, the physical interaction between APP and presenilins in the
endoplasmic reticulum has been demonstrated and might play a key role in Abeta42
production. It was hypothesized that PS1 might directly cleave APP. However,
extracellular amyloidogenesis and Abeta production might not be the sole factor
involved in AD pathology and several lines of evidence support a role of
apoptosis in the massive neuronal loss observed. Presenilins were shown to modify
the apoptotic response in several cellular systems including primary neuronal
cultures. Some evidence is accumulating which points towards the beta-catenin
signaling pathways to be causally involved in presenilin mediated cell death.
Increased degradation of beta-catenin has been shown in brain of AD patients with
PS1 mutations and reduced beta-catenin signaling increased neuronal vulnerability
to apoptosis in cell culture models. The study of presenilin physiological
functions and the pathological mechanisms underlying their role in pathogenesis
clearly advanced our understanding of cellular mechanisms underlying the neuronal
cell death and will contribute to the identification of novel drug targets for
the treatment of AD.
PMID- 10670706
TI - Endothelin and dopamine release.
AB - Endothelins and endothelin receptors are widespread in the brain. There is
increasing evidence that endothelins play a role in brain mechanisms associated
with behaviour and neuroendocrine regulation as well as cardiovascular control.
We review the evidence for an interaction of endothelin with brain dopaminergic
mechanisms. Our work has shown that particularly endothelin-1 and ET(B) receptors
are present at significant levels in typical brain dopaminergic regions such as
the striatum. Moreover, lesion studies showed that ET(B) receptors are present on
dopaminergic neuronal terminals in striatum and studies with local administration
of endothelins into the ventral striatum showed that activation of these
receptors causes dopamine release, as measured both with in vivo voltammetry and
behavioural methods. While several previous studies have focussed on the possible
role of very high levels of endothelins in ischemic and pathological mechanisms
in the brain, possibly mediated by ET(A) receptors, we propose that physiological
levels of these peptides play an important role in normal brain function, at
least partly by interacting with dopamine release through ET(B) receptors.
PMID- 10670707
TI - Modeling of separations by closed-loop steady-state recycling chromatography of a
racemic pharmaceutical intermediate.
AB - Closed-loop steady-state recycling (SSR) is a cyclic, one-column process that is
similar to simulated moving bed (SMB) chromatography in several respects. Both
processes are cyclic. In both SMB and SSR, fractions are collected from the
leading and trailing portions of the circulating chromatographic profile, and
fresh sample is injected into the interior of the profile. However, SMB is a
continuous process whereas SSR is a discontinuous, repetitive process. This paper
presents a model for the closed-loop SSR process and its experimental validation
in a case of practical importance. For this last purpose, we used the closed-loop
SSR separation of the enantiomers of a racemic pharmaceutical intermediate. The
experimental determination of the competitive adsorption equilibria was performed
by frontal analysis in a system composed of a chiral HPLC column as the
stationary phase and pure acetonitrile as the mobile phase. All the adsorption
data were well correlated by the Langmuir model. The Langmuir model was used to
calculate overloaded band profiles corresponding to the separation of racemic
mixtures at both analytical and preparative scales. Theoretical band profiles
were calculated using the equilibrium-dispersive model. With proper corrections
for the contributions of the sources of extra-column band broadening, the model
properly predicts the experimental band profiles obtained in the closed-loop SSR
setup and demonstrates that a cyclic steady-state develops after the completion
of a finite number of cycles. The results also show that the extra-column effects
must be accounted for in order to model the closed-loop SSR process accurately.
PMID- 10670708
TI - Simultaneous optimization of the analysis time and the concentration
detectability in open-tubular liquid chromatography.
AB - Scott's OT-LC minimal analysis time problem has been solved analytically and has
been extended to thick-film and/or large diameter columns. The optimisation
analysis has also been applied to a number of relative performance indexes
(Cmax/t(anal), Cmax x d/t(anal) and Cmax x u x d2/t(anal) which provide a
quantitative insight on the extent to which OT-LC allows to combine short
analysis times with a large concentration detectability.
PMID- 10670709
TI - Dissociation constants of phenols in methanol--water mixtures.
AB - A preferential solvation model that relates solute properties with solvent
composition in binary mixtures has been applied to the dissociation pKa values of
a set of 28 substituted phenols in methanol-water mixtures. The parameters of the
model allow estimation of the pKa value of each phenol for any methanol-water
composition. Moreover, it is demonstrated that the pKa values of the whole set of
phenols at any methanol-water composition are linearly related to the pKa values
of the phenols in water. Equations that relate the correlations' slope and
intercept values with the solvent composition have been derived and tested with
the set of phenols. The general parameters obtained for these equations allow an
accurate calculation of the pKa value of any phenol, even of those not included
in the original set, at any methanol-water composition solely from the pKa value
of the phenol in water. These calculated pKa values can be used for quantitative
structure-HPLC retention relationships. The method is tested by comparison of the
calculated pKa values with the HPLC determined pKa values of 26 phenols in a
polymeric column with a 50% methanol as mobile phase.
PMID- 10670710
TI - Ion exchange on resins with temperature-responsive selectivity IV. Influence of
solution and column parameters on efficiency of reagentless separation of copper
and zinc using thermo-induced concentration waves technique.
AB - The effect of solution and column parameters such as pH, ratio of metal ions and
the height of resin bed on formation of the thermo-induced concentration waves
(TICW) in the course of the thermostripping process of Cu2+ and Zn2+ ions from
iminodiacetic resin Lewatit TP-207 has been studied. The formation of TICW is
attributed by both different diffusivities of metal ions and the presence of the
third (H+) ion in the system. This effect makes it possible to carry out a
reagentless separation of metal ions by using either the metal depletion or metal
concentration mode of operation. The efficiency of the TICW-based separation
process by using the metal depletion mode appears to be the higher the lower
relative concentration of metal ion under removal (slower diffusing ionic
species). The mathematical model proposed allows for qualitative and quantitative
description of thermostripping processes in a wide range of pH and solution
compositions. The physical model of the TICW process proposed makes it possible
to account for the influence of different process parameters and generalise the
applicability of the TICW separation technique to the binary mixtures of any
metal ions with different diffusivities.
PMID- 10670711
TI - Visualization of solute migration in chromatographic columns quantitation of the
concentration in a migrating zone.
AB - The concentration distribution across a zone of iodine migrating along a column
made of glass, packed with C18-bonded silica, and eluted with carbon
tetrachloride was derived from a quantitative analysis of the photographs of the
zone. The photographs were scanned and turned into digital images. The intensity
distributions obtained from the measurement of the grayscale intensity were
converted into concentration profiles using a calibration method. This procedure
is illustrated and suitable corrections are introduced to account for the
transverse variation of the optical path length, as a result of using a
cylindrical detector cell (the column itself), and for the refraction of light
due to the differences between the refraction indices of the glass wall and the
liquids involved. An error analysis is also reported. It shows that the method
can reliably produce results with a precision of a few percent, allowing on
column evaluation of column performance and the derivation of the radial
distributions of the column efficiency, the migration velocity of the zone, and
the sample distribution at the head of the column.
PMID- 10670712
TI - High-sensitivity chromatographic detector incorporating three-dimensional charge
coupled device fluorimetry.
AB - This article describes a detector for liquid chromatography that provides three
dimensional, excitation-emission-intensity data of fluorescent compounds. The
instrument achieves multi-wavelength excitation by employing a polychromator that
disperses radiation along the vertical portion of a quartz capillary flow cell.
The ensuing sample fluorescence is collected in the horizontal plane and
dispersed using an emission polychromator to form a focused two-dimensional
excitation-emission image at a charge coupled device (CCD) pixel array. Each
vertical pixel equates to a narrowly defined excitation wavelength band, whilst
horizontal pixels equate to corresponding emission wavelengths, with the
intensity of light encroaching onto the CCD pixel elements providing the third
dimensional variable in the measurement. It is shown that the extreme sensitivity
of CCD detection coupled to the dual polychromator arrangement makes possible the
collection of fluorescence excitation-emission-intensity data of polycyclic
aromatic hydrocarbons in a flow stream in less than 0.05 s with nanogram per
millilitre limits of detection.
PMID- 10670713
TI - Size-exclusion chromatography--multiangle laser light scattering analysis of beta
lactoglobulin and bovine serum albumin in aqueous solution with added salt.
AB - The solution characteristics of beta-LGB (beta-lactoglobulin) and BSA (bovine
serum albumin) are reported as determined by size-exclusion chromatography with
on-line multiangle laser light scattering, differential refractive index and UV
detection. The order of the three in series placed detectors as well as the
interdetector volumes have been carefully pointed out. At concentrations below
2.5 mg/ml and at different values of pH the weight-average molecular mass of both
proteins have been obtained. They indicate the appearance of monomers, dimers and
higher order multimers. For beta-LGB the growth of self-associates could be
observed at the isoelectric point over a period of days. The range of
applicability of the method is discussed.
PMID- 10670714
TI - Enhanced performance of expanded bed chromatography on rigid superporous
adsorbent matrix.
AB - Rigid spherical macroporous adsorbent beads with surface hydroxyl groups were
prepared by cross-linking of cellulose. These beads had diameter in the range 100
200 microm and a mean pore size of about 3 microm with about 60% pore volume. The
matrix (bulk density approximately 1600 kg m(-3)) could be expanded into a stable
bed and used for protein chromatography. Chromatographic runs were performed on a
10 mm diameter column under non-retaining and retaining conditions on the
prepared matrix (called Celbeads) and performance of the runs was measured in
terms of the height equivalent to a theoretical plate (HETP). The HETP curves in
both packed and expanded bed modes followed profiles typical of macroporous
adsorbents, i.e. increasing and levelling with velocity. Unimpaired performance
of the matrix at increasing flow-rates permitted expanded bed elution of adsorbed
solutes without loss of efficiency in terms of purification factor and product
concentration. As a model system, Celbeads was used to purify lactate
dehydrogenase from porcine muscle homogenate by dye-affinity chromatography. The
prepared matrix provided about 100 theoretical plates per meter for the enzyme
system at a linear flow velocity of 1.27 cm x min(-1) in an expanded bed elution
mode, and gave enzyme yields of 100% with a purification factor of 31 using an
optimized procedure. The adsorbent could be cleaned in place with 5 M urea and
used repeatedly without loss of performance.
PMID- 10670715
TI - Effect of stationary phase hydrophobicity and mobile phase composition on the
separation of carboxylic acids in ion chromatography.
AB - In a previous work, we studied the retention behavior of monovalent and divalent
carboxylic acids on a highly cross-linked polystryene-divinylbenzene anion
exchange column (IonPac AS4A-SC) using a carbonate-based buffer, and a retention
model was applied to the chromatographic data obtained. In this work we
characterized the retention of carboxylates (formic, acetic, propionic, lactic,
pyruvic, oxalic, malonic, succinic, fumaric, maleic, tartaric, glutaric, adipic,
malic, mucic, trans-beta-hydromuconic, trans,trans-muconic acids) on a column
with higher hydrophilicity (IonPac AS11) according to analyte and stationary
phase properties, using previously investigated eluent compositions and comparing
the retention data obtained. Moreover, the effect of organic modifiers (CH3OH and
CH3CN) in the eluent on the retention factors was also evaluated. The
chromatographic data obtained on the IonPac AS11 column were fitted by the
retention model and allowed one to obtain and to compare ion-specific selectivity
constants (parameters of the model) with the ones obtained with the previous
column.
PMID- 10670716
TI - Comparative methodology in the determination of alpha-oxocarboxylates in aqueous
solution ion chromatography versus gas chromatography after oximation, extraction
and esterification.
AB - The alpha-oxocarboxylates (alpha-ketocarboxylates) and the corresponding alpha
oxoacids (alpha-ketoacids) have been reported as byproducts of ozonation of
potable water supplies. Some of these species also occur in biophysiological
systems. Five analytes were investigated in this study: oxoethanoate
(glyoxylate), 2-oxopropanoate (pyruvate), 2-oxobutanoate (2-ketobutyrate), 2
oxopentanoate (2-ketovalerate) and oxopropanedioate (ketomalonate, mesoxalate).
Ion chromatography (IC) and gas chromatography (GC) were evaluated for the
quantitation of these analytes at concentrations < or =200 ng ml(-1). For the IC
method, the samples are run directly with minimal to no pre-treatment. For the GC
method, the analytes must be derivatized with O-(2,3,4,5,6
pentafluorobenzyl)oxylamine to form oximes. The oximes are extracted into tert
butyl methyl ether and the carboxylic acid is esterified (methylated) with
diazomethane. It was concluded that the ion chromatographic determination is
significantly superior to the gas chromatographic method for these analytes.
PMID- 10670717
TI - Peptide map procedure using immobilized protease cartridges in tandem for
disulfide linkage identification of neu differentiation factor epidermal growth
factor domain.
AB - Immobilized proteolytic enzyme cartridges were used to rapidly digest neu
differentiation factor EGF domain in order to obtain improved peptide maps useful
for assignment of disulfide linkages. The procedure described here involves an on
line digestion of proteins using immobilized trypsin and endoproteinase Glu-C
cartridges connected in series, followed by on-line RP-HPLC separation of the
peptides. The entire process can be automated using a commercially available
workstation; and the total time required for both proteolytic digestion and the
HPLC separation can be shortened to within 1 h. Using these immobilized columns,
we demonstrated that disulfide structure assignment of the EGF domains of
recombinant human neu differentiation factor can be performed by isolation of
individual disulfide-containing peptides followed by assignment of disulfide
linkages with prompt fragmentation of peptides using matrix-assisted laser
desorption/ionization time-of-flight mass spectrometry. The use of immobilized
protease cartridges in tandem eliminates undesirable digestion artifacts
associated with longer digestion time and higher protease-to-substrate ratio and
results in the development of a reproducible and high quality peptide map.
PMID- 10670718
TI - New affinity nylon membrane used for adsorption of gamma-globulin.
AB - Microporous polyamide membranes were first modified by acid hydrolysis and
subsequently bound with hydroxy-ethylcellulose to amplify reactive groups and
reduce nonspecific interactions with proteins. Then 1,6-diaminohexane as space
arm and phenylalanine as ligand were immobilized onto the nylon membranes by s
triazine trichloride activation. Affinity membranes thus obtained were set in a
stack and used to adsorb gamma-globulin. The adsorption capacity (qm) of the
affinity membrane is 53 micro gamma-globulin per m2 membrane and the desorption
constant (Kd) is 2.35 x 10(-6) mol/l. The effects of feed, washing and elution
rates on adsorption and desorption behavior were investigated. The results showed
that affinity purification through these membranes could not be operated at very
high flow-rates. A stack of 20 membranes with 47 mm diameter can adsorb 7.8 mg
gamma-globulin with a purity of 91.6% from 4 ml of human plasma in a single-pass
mode.
PMID- 10670719
TI - Determination of phenoxyalkanoic acids and other herbicides at the ng/ml level in
water by solid-phase extraction with poly(divinylbenzene-co-N-vinylpyrrolidone)
sorbent and high-performance liquid chromatography--diode-array detection.
AB - A method for the determination of phenoxyalkanoic acids and other polar compounds
in environmental water samples without pH adjustment before extraction has been
developed. Recoveries were calculated from 500 ml of milliQ water spiked at the
level of 0.5 ng/ml using solid-phase extraction (SPE) and HPLC-DAD. Different SPE
materials (RP-C18, ENV+, ENV+-C8, SAX and Oasis HLB) were tested. After method
optimization, 15 of the 16 compounds studied could be extracted with recoveries
better than 70% on the most suitable copolymeric poly(divinylbenzene-co-N
vinylpyrrolidone) material (Oasis HLB cartridges).
PMID- 10670720
TI - Synthesis and characteristics of [60]fullerene polysiloxane stationary phase for
capillary gas chromatography.
AB - A new type of fullerene-containing polysiloxane was synthesized by reacting
[60]fullerene with azidopropyl polysiloxane directly. The polysiloxanes have been
used successfully as stationary phases for capillary gas chromatography. They
displayed high column efficiency, wide operational temperature and high
thermostability, and exhibited unique selectivity for many organic substances,
such as alkanes, alcohols, ketones and aromatic compounds. The stationary phase
was especially suitable for separation of high boiling-point compounds like
polycyclic aromatic hydrocarbons and phthalic esters, etc. It was also found that
some alcoholic or aromatic positional isomers could be well separated on the
column. The influence of the fullerene content on the separation was also
investigated.
PMID- 10670721
TI - Identification of compounds and specific functional groups in the wavelength
region 168-330 nm using gas chromatography with UV detection.
AB - A GC-UV instrumental set up with two different GC units has been used for
determination of specific functional groups and compounds in complex mixtures.
Separations have been made using a micro gas chromatograph built into a gas flow
cell and by means of an external capillary gas chromatograph linked to the same
gas flow cell. Four various applications (cigarette smoke, petroleum, dust,
flavour) have been performed in order to demonstrate the potential of the GC-UV
method. Gas phase UV spectra have been recorded in the region of 168-330 nm.
Based on a gas phase spectrum reference library the identification of unknowns as
well as the determination of specific functional groups have been achieved. A
table showing the spectral shapes and positions of the absorption bands for 50
specific functional groups is presented. The advantage of using derivative
spectra in order to amplify spectral details and improve selectivity is
discussed. Regarding sensitivity, it has been found that identifications can be
made in the mid-pg range and limit of detection for naphthalenes are at a level
of 0.5-3 pg/s.
PMID- 10670722
TI - On-line coupling of equilibrium-sorptive enrichment to gas chromatography to
determine low-molecular-mass pollutants in environmental water samples.
AB - On-line combination of equilibrium sorptive enrichment and gas chromatography is
used for the analysis of a group of pollutants varying widely in polarity and
volatility in aqueous samples at trace levels. For the ESE process open-tubular
traps were used. The newly developed hyphenated method shows a high sensitivity
for all the compounds under study. The detection limits were typically between
0.1 and 1 microg/l. The sample volumes required for the compounds to reach
equilibrium with the stationary phase are in the range of 20 ml for the aromatic
hydrocarbons included in the study (benzene, toluene and p-xylene), to 200 ml for
epichlorohydrin and dichlorohydrin. Within- and between-day precision of the
absolute peak areas varied between 3 and 16%. The performance of the new method
was tested by the analysis of different environmental water samples.
PMID- 10670723
TI - Ultra trace detection of a wide range of anabolic steroids in meat by gas
chromatography coupled to mass spectrometry.
AB - The control on use of anabolic agents in meat producing animals is generally
based on urine, faeces or hair analysis. This exercise, which is usually
performed in slaughterhouses or on farms, is not relevant to imported carcasses
or retail meat. A single sensitive method for a wide range of anabolic steroids
was developed. After extraction of the lyophilised meat, enzymatic hydrolysis was
used for deconjugation. Solid-phase extraction on a polymeric stationary phase
was performed prior to hydrolysis of ester residues under alkaline conditions.
Liquid-liquid partitioning was used to separate the analytes into two main
categories: phenol containing molecules, such as phenolic steroids, resorcylic
acid lactones and stilbenes, and delta4-3-one containing molecules, such as most
androgens and progestagens. Solid-phase extraction on silica columns was
performed before applying a specific derivatisation for each compound sub-group.
The combination of high-resolution chromatography with a quadrupole mass
spectrometer permitted detection of 23 steroids in the 5-100 ng/kg range. Ion
chromatograms for residue positive samples are shown and discussed.
PMID- 10670724
TI - Pesticide trace analysis using solid-phase extraction and gas chromatography with
electron-capture and tandem mass spectrometric detection in water samples.
AB - Gas chromatography (GC) with electron-capture detection (ECD), mass spectrometry
(MS) and tandem mass spectrometry (MS-MS) were employed for the identification of
12 pesticides in water samples. For this purpose, a solid-phase extraction
procedure with C18 cartridges was used, optimising the breakthrough volume and
the saturation concentration. In GC-MS-MS, the lowest detectable concentrations
for the pesticides were between 2 and 26 ng l(-1), recoveries ranged from 70 to
133% in water samples spiked at 100 ng l(-1) and the relative standard deviations
were in the range 5.3 to 17.4%. The proposed analytical methodology was applied
to analyse pesticides in wetland samples from Almeria (Spain).
PMID- 10670725
TI - Resolution optimisation in micellar electrokinetic chromatography using empirical
models.
AB - Theoretical and empirical models can be used to model the migration or separation
characteristics in micellar electrokinetic chromatography in order to optimise
the resolution. In this paper only empirical models were used, because it is
easier and more straightforward to obtain these models. Several empirical
approaches for the optimisation of the resolution were compared in order to
determine which response should be modelled preferably. The use of models of the
effective mobility in combination with average plate numbers proved to be the
most suitable approach to optimisation of the resolution, because the relative
prediction errors of the models of the effective mobility were a factor of 2-4
smaller than the relative prediction errors of the models of the apparent
mobility. Moreover for the least separated peak pair the resolutions based on the
models of the apparent and effective mobility showed relative prediction errors
that were approximately a factor of 2 smaller than the relative prediction errors
of the resolutions based on the models of the resolution and separation factor.
The predictions of the separation factor based on the different models generally
showed lower prediction errors than the predictions of the corresponding
resolutions. Although the relative prediction errors were large, particularly for
closely migrating compounds, the empirical approach will probably lead to the
optimum separation buffer composition.
PMID- 10670726
TI - Simultaneous determination of polycarboxylic acids by capillary electrophoresis
with a copper electrode.
AB - The simultaneous determination of polycarboxylic acids including oxalic acid,
citric acid, malonic acid, malic acid, tartaric acid, aspartic acid and glutamic
acid was achieved by capillary electrophoresis with a copper disk electrode (d =
200 microm). In the system. 0.2 mmol/l cetylpridinium bromide (CPB) was used as
an electroosmotic flow (EOF) modifier to reverse the direction of EOF. The
effects of the solution pH and CPB concentration on separation were evaluated to
achieve the optimum separation conditions. At the working potential of +0.14 V
(vs. saturated calomel electrode), the calibration curves for all polycarboxylic
acids studied were linear with 2 approximately 3-orders of magnitude and all the
detection limits (S/N = 3) were below 15 fmol except malonic acid. Furthermore,
the oxalic and citric acids in urine were successfully separated and determined
with high sensitivity.
PMID- 10670727
TI - Microchip capillary electrophoresis using on-line chemiluminescence detection.
AB - Chemiluminescence detection was used in capillary electrophoresis integrated on a
microchip. Quartz microchips have two main channels and four reservoirs. Dansyl
lysine and -glycine were separated and detected with bis[(2-(3,6,9
trioxadecanyloxycarbony)-4-nitrophenyl]oxalate as peroxyoxalate chemiluminescent
reagent. These dansyl amino acids came into contact with the chemiluminescence
reagent to produce visible light at the interface between the separation channel
and chemiluminescence reagent-containing reservoir. The detection limit (S/N = 3)
for dansyl-lysine was 1 x 10(-5) M, which corresponded to the very small mass
detection limit of ca. 0.4 fmol. However, the concentration sensitivity in the
present system was approximately two orders of magnitude lower than that in the
conventional capillary electrophoresis-chemiluminescence detection system. The
relative standard deviations of migration time and peak height for dansyl-lysine
were 4.2 and 4.5%, respectively. A channel conditioning before every run and an
appropriate control of voltages were needed for the reproducible results. The
present system had advantages in rapid separation time (within 40 s), small
(several 10 pI) and accurate sample injection method using a cross-shaped
injector, and simplification and miniaturization of the detection device.
PMID- 10670728
TI - Determination of phenols using simultaneous steam distillation-extraction.
AB - Simultaneous distillation-extraction was proposed as a preconcentration step for
the determination of phenol and its derivatives in aqueous and soil samples.
Detection limits of 0.01 mg l(-1) (water) and 0.1 mg kg(-1) (soil) were achieved
by gas chromatography-flame ionization detection. The described preconcentration
procedure was applied for the primary study of the adsorption equilibrium in a
water-soil system serving as a model of phenol behaviors in the environment.
PMID- 10670729
TI - Development of a protocol for the automated analysis of amino acids in brain
tissue samples and microdialysates.
AB - An automated precolumn derivatisation method has been developed for the
measurement of fourteen amino acids in brain tissue and microdialysate samples.
The method involves labelling amino acids with naphthalene-2,3-dicarboxaldehyde
(NDA) in the presence of cyanide (CN-). The resulting highly stable N-substituted
1-cyanobenz[f]isoindole (CBI) derivatives were separated using a binary gradient
elution profile and detected fluorometrically. The order of elution of the
derivatised amino acids was confirmed by using liquid chromatography with
fluorescence and mass spectrometric detection in tandem. Linear calibration plots
were obtained for all amino acids in the range studied (0.2-12.5 microM). The
limit of detection for CBI derivatives of amino acids was in the range 5-20 fmol
(S/N=2) using a 5 microl injection volume. The method has been used for the
measurement of amino acids in microdialysates from rat brain and tissue
homogenates from different regions of mouse brain.
PMID- 10670730
TI - Simultaneous determination of the enantiomers of leucine and [2H7]leucine in
plasma by capillary gas chromatography-mass spectrometry.
AB - A method for the stereoselective assay of D- and L-enantiomers of both leucine
and [2H7]leucine in rat plasma was developed using gas chromatography-mass
spectrometry-selected-ion monitoring. DL-[2H3]leucine was used as an internal
standard. The method involved purification by cation-exchange chromatography
using BondElut SCX cartridge and derivatization with hydrochloric acid in
methanol to form methyl ester followed by subsequent chiral derivatization with
(+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride to form
diastereomeric amide. The derivatization made the separation of the leucine
enantiomers possible with good gas chromatographic behavior. Quantitation was
performed by selected-ion monitoring of the quasi-molecular ions of the
diastereomers on the chemical ionization method. The sensitivity, specificity,
accuracy and reproducibility of the method were demonstrated to be satisfactory
for application to pharmacokinetic studies of leucine enantiomers.
PMID- 10670731
TI - Determination of dihydroergotamine in human plasma by high-performance liquid
chromatography with fluorescence detection.
AB - Dihydroergotamine, a 5-hydroxytryptamine antagonist, is used for the treatment of
vascular headaches. A high-performance liquid chromatography assay with
fluorescence detection is described for the determination of dihydroergotamine in
plasma. The assay was validated over the concentration range 0.1-10 ng/ml plasma
and applied to the analysis of plasma samples from subjects treated
intramuscularly and intranasally with 2 mg of dihydroergotamine.
PMID- 10670732
TI - Determination of nelfinavir, a potent HIV protease inhibitor, and its active
metabolite M8 in human plasma by high-performance liquid chromatography with
photodiode-array detection.
AB - We developed and characterized a high-performance liquid chromatographic assay
for the determination of nelfinavir (NFV), a potent HIV protease inhibitor, and
its active metabolite M8 in human plasma. Extraction of the internal standard, M8
and NFV from the plasma buffered at pH 9.5 was achieved by a liquid-liquid
extraction with a mixture of methyl-tert.-butyl ether and hexane. Following two
washes of the reconstituted sample with hexane, separation was achieved on an
octadecylsilyl analytical column with a mobile phase containing 0.1%
trifluoroacetic acid-acetonitrile-methanol (51:46:5, v/v). Detection was
performed using an ultraviolet photodiode-array detector. The signal was
monitored at a wavelength of 220 nm. The assay was found to be linear and has
been validated over the concentration range of 25 to 3000 microg/l for M8 and 25
to 6000 microg/l for NFV, from 500 microl of plasma. Recoveries were 98.9% (SD
8.9%), and 100.2% (SD 11.7%) for M8 and NFV, respectively. Concentrations that
gave a signal-to-noise ratio of three (15 microg/l for both M8 and NFV) were
selected to determine the limit of detection. The lower limit of quantification
(25 microg/l for both M8 and NFV) was defined as the concentration for which the
relative standard deviation and the percent deviation from the nominal
concentration were lower than 20%.
PMID- 10670733
TI - Determination of carnitine and acylcarnitines in biological samples by capillary
electrophoresis-mass spectrometry.
AB - Free carnitine and acylcarnitines (carnitine esters) play an important role in
the metabolism of fatty acids. Metabolic disorders can be detected by abnormal
levels of these compounds in biological fluids. Capillary electrophoresis-mass
spectrometry has the advantage of combining an efficient separation technique
with highly selective detection. Therefore, we have developed a method for the
determination of carnitine and several of its esters implementing electrospray
capillary electrophoresis-mass spectrometry in the positive ion selected reaction
monitoring mode. A sheath-flow interface with a mixture of 2-propanol or
methanol, water and acetic acid as sheath liquid and nitrogen as nebulizing gas
was used. The zwitterionic analytes migrated as cations in the applied electric
field using ammonium acetate-acetic acid or formic acid electrolytes. Separations
were performed in aqueous, mixed organic-aqueous and non-aqueous media. The
influence of the electrolyte composition on the separation efficiency was
investigated. The electrospray conditions have been optimized regarding ion
current stability and sensitivity. Ammonium acetate (10 mmol/l)-0.8% formic acid
in water or 6.4% formic acid in acetonitrile-water (1:1) were used as running
buffers for the determination of carnitine and acylcarnitines in human biological
samples. Methanol extracts of dried blood spots were analyzed as well as urine
and plasma following sample preparation via solid-phase or liquid-liquid
extraction. Recoveries approaching 100% were achieved depending on the analytes
and sample preparation procedures employed. Endogenous carnitine and
acetylcarnitine were determined at concentrations between 2.7 and 108 nmol/ml in
normal human urine and plasma. Other acylcarnitines were detected at levels of
below the limit of detection to 12 nmol/ml. Good precision (0.8 to 14%) and
accuracy (85 to 111%) were obtained; the achieved limits of quantitation (0.1 to
1 nmol/ml) are sufficient to characterize carnitine and acylcarnitine levels
occurring as markers for metabolic disorders.
PMID- 10670734
TI - Gas chromatographic-tandem mass spectrometric determination of anabolic steroids
and their esters in hair. Application in doping control and meat quality control.
AB - We have developed a powerful and simple sensitive method for testing hair for
anabolic steroids and their esters. A 100-mg amount of powdered hair was treated
with methanol in an ultrasonic bath for extraction of esters, then alkaline
digested with 1 M NaOH for an optimum recovery of other drugs. The two liquid
preparations were subsequently extracted with ethyl acetate, pooled, then finally
highly purified using a twin solid-phase extraction on amino and silica
cartridges. The residue was derivatized with N-methyl-N(trimethylsilyl)
trifluoracetamide (MSTFA) prior to injection. Analysis was conducted by gas
chromatography coupled to a triple quadrupole mass spectrometer. The generally
chosen parent ion was the molecular ion while two daughter ions were selected for
each compound with collision energies ranging from -16 to -21 eV. Internal
standards were nandrolone d3 for non-esterified drugs and testosterone phenyl
propionate for esters. The limits of detection calculated from an analysis of the
blanks (n=30) were 0.08 pg/mg for nandrolone, 6.20 pg/mg for boldenone, 0.07
pg/mg for methyl testosterone, 0.15 pg/mg for ethinyl estradiol, 2.10 pg/mg for
metandienone, 0.86 pg/mg for testosterone propionate, 0.95 pg/mg for testosterone
cypionate, 1.90 pg/mg for nandrolone decanoate, 3.10 pg/mg for testosterone
decanoate and 4.80 pg/mg for testosterone undecanoate. Application to doping
control has been demonstrated. In a series of 18 sportsmen, two tested positive
for anabolic steroids in hair whereas urinalysis was negative for both of them.
The first positive case was nandrolone and the second case concerned the
identification of testosterone undecanoate. Measured in 10 white males aged
between 22 and 31 years, the testosterone concentration was in the range 1.7-9.2
pg/mg (mean=5.0 pg/mg). The method was also applied in meat quality control. Of
the 187 analyses realized based upon hair and urine sampling in slaughter houses,
23 were positive for anabolic steroids in hair: one case for boldenone, one case
for metandienone, two cases for testosterone propionate, three cases for
nandrolone, five cases for testosterone decanoate and 11 cases for methyl
testosterone. In the meantime, urinalysis was always negative for these drugs or
their metabolites.
PMID- 10670735
TI - Immunopurification of the blood group RhD protein from human erythrocyte
membranes.
AB - Rh proteins are membrane proteins encoded by genes at the blood group RH locus.
They are of paramount importance in transfusion medicine, but their function is
still unknown. Biochemical and biophysical studies of these proteins are scarce
since only minute amounts of the very hydrophobic Rh proteins, can be purified
from human erythrocytes. Recently, a human monoclonal antibody (LOR-15C9) was
described as having the unique property to recognize the Rh30 protein carrying
the major blood group D specificity (RhD protein), either in a membrane detergent
extract or when blotted on a membrane. In this report, we describe one-step
purification of the RhD protein from detergent extracts of red cell membranes,
based on immunoaffinity chromatography carried out with immobilized LOR-15C9 IgG.
The technique yielded RhD protein with high purity which was devoid of other
associated proteins (RhAG, CD47, LW and GPB) that comprise the Rh complex in the
erythrocyte membrane. By contrast immunoprecipitation performed with the same
antibody led to co-isolation of both RhD and RhAG.
PMID- 10670736
TI - Determination of reduced and oxidized homocysteine and related thiols in plasma
by thiol-specific pre-column derivatization and capillary electrophoresis with
laser-induced fluorescence detection.
AB - A new sensitive and rapid capillary electrophoresis (CE) assay for measuring
reduced and oxidized thiols in human plasma has been developed. To prevent
oxidation of the thiols, whole blood was immediately centrifuged after collection
and the plasma proteins were precipitated with perchloric acid. The reduced
thiols in the supernatant were derivatized quantitatively at 25 degrees C, pH 7.5
with a fluorescent reagent, fluorescein-5-maleimide (FM). The total plasma
concentration of thiols, including the fraction coupled to proteins, was assayed
after an initial reduction of the disulfide linkage in plasma with
dithiothreitol. The separation of FM-thiols was performed in an acetonitrile/10
mM sodium phosphate-50 mM SDS buffer [25:75 (v/v); pH 7.0] using a fused-silica
capillary (57 cm x 75 microm I.D.) at 45 degrees C. A 3-mW argon-ion laser
(lambda(ex) 488 nm/lambda(em) 520 nm) was employed for FM-thiol detection. With
the electric field of 530 V/cm, the time needed for the separation of FM
homocysteine, FM-glutathione and FM-N-acetylcysteine was less than 8 min. The
lower limit of detection was 3 microM for the total thiols and 10 nM for the
reduced thiols. The method was applied to, the determination of homocysteine
levels in plasma from patients with end-stage renal disease.
PMID- 10670737
TI - Routine analysis of amphetamine class drugs as their naphthaquinone derivatives
in human urine by high-performance liquid chromatography.
AB - We describe a simple HPLC method which is suitable for the routine confirmation
of immunoassay positive amphetamine urine samples. The precolumn derivisation
method employing sodium naphthaquinone-4-sulphonate was found to have adequate
sensitivity, selectivity and precision for the measurement of amphetamine,
methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), 3,4
methylenedioxyamphetamine (MDA), and 3,4-methylenedioxyethylamphetamine (MDEA) at
500 microg/l cutoff level for confirmatory analysis of amphetamines in urine. The
specificity of the method is enhanced by detecting the peaks at two different
wavelengths. The ratios of the peak heights measured at the two wavelengths were
different for each of the 5 amphetamines analysed. There was no interference from
other phenylethylamine analogues that are commonly found in "over the counter"
preparations. The HPLC method is compared to a commercial TLC system for
detecting amphetamines in urine of drug abusers attending drug rehabilitation
programmes. The HPLC confirmatory method described is a viable alternative to GC
or to the more complex and costly GC-MS techniques for confirming amphetamine,
methamphetamine, MDMA, MDA and MDEA in urine of drug abusers especially when used
in a clinical care setting.
PMID- 10670738
TI - Simple and reliable high-performance liquid chromatography fluorimetric procedure
for the determination of amphetamine-derived designer drugs.
AB - The paper describes a HPLC-fluorimetric procedure for the determination of
methylenedioxyamphetamine, methylenedioxymethamphetamine,
methylenedioxyethamphetamine and N-methyl-1-(1,3-benzodioxol-5-yl)-2-butanamine
in urine, serum, saliva and street samples, that features interesting advantages
over other procedures previously described. The method requires a very small
sample volume (100 microl) and no extraction, lacks matrix effect, and is not
time consuming. Linearity was in the range 50-1000 ng/ml regardless of matrix.
Sensitivity and detection limit were 50 ng/ml and 10 ng/ml, respectively, but
they may reach 10 ng/ml and 2 ng/ml if a slight modification is introduced in the
procedure. Intra- and inter-day precision were always within 5% and 8%,
respectively. Recovery was satisfactory for all matrices. The described procedure
could be successfully used for clinical, epidemiological and forensic
applications.
PMID- 10670739
TI - Simultaneous assay of morphine, morphine-3-glucuronide and morphine-6-glucuronide
in human plasma using normal-phase liquid chromatography-tandem mass spectrometry
with a silica column and an aqueous organic mobile phase.
AB - Morphine (MOR) is an opioid analgesic used for the treatment of moderate to
severe pain. MOR is extensively metabolized to morphine-3-glucuronide (M3G) and
morphine-6-glucuronide (M6G). A rapid and sensitive method that was able to
reliably detect at least 0.5 ng/ml of MOR and 1.0 ng/ml of M6G was required to
define their pharmacokinetic profiles. An LC-MS-MS method was developed in our
laboratory to quantify all three analytes with the required sensitivity and a
rapid turnaround time. A solid-phase extraction (SPE) was used to isolate MOR,
M3G, M6G, and their corresponding deuterated internal standards from heparinized
plasma. The extract was injected on a LC tandem mass spectrometer with a turbo
ion-spray interface. Baseline chromatographic separation among MOR, M3G, and M6G
peaks was achieved on a silica column with an aqueous organic mobile phase
consisting of formic acid, water, and acetonitrile. The total chromatographic run
time was 3 min per injection, with retention times of 1.5, 1.9 and 2.4 min for
MOR, M6G, and M3G, respectively. Chromatographic separation of M3G and M6G from
MOR was paramount in establishing the LC-MS-MS method selectivity because of
fragmentation of M3G and M6G to MOR at the LC-MS interface. The standard curve
range in plasma was 0.5-50 ng/ml for MOR, 1.0-100 ng/ml for M6G, and 10-1000
ng/ml for M3G. The inter-day precision and accuracy of the quality control (QC)
samples were <7% relative standard deviation (RSD) and <6% relative error (R.E.)
for MOR, <9% RSD and <5% R.E. for M6G, and <3% RSD and <6% R.E. for M3G. Analyte
stability during sample processing and storage were established. Method
ruggedness was demonstrated by the reproducible performance from multiple
analysts using several LC-MS-MS systems to analyze over one thousand samples from
clinical trials.
PMID- 10670740
TI - Comparison of different elution conditions for the immunopurification of
recombinant hepatitis B surface antigen.
AB - An immunoaffinity chromatographic method was developed using a mAb immunosorbent
to purify recombinant hepatitis B surface antigen (r-HBsAg) from yeast. Elution
conditions using a mAb-coated ELISA were improved to select the best conditions
to purify r-HBsAg. The optimum results in terms of total quantitative recovery
were obtained using 20 mM Tris pH 11.6. An increase in the CB.Hep-1 mAb (anti
HBsAg) useful immunosorbents half-life and in its yield per cycle was obtained
when alkaline elution conditions were used. Moreover, the basic conditions do not
affect either the antigenic characteristics or the purity or the molecular
integrity of r-HBsAg.
PMID- 10670741
TI - Simple high-performance liquid chromatographic method for the determination of
tocotrienols in human plasma.
AB - A simple high-performance liquid chromatographic method using fluorescence
detection was developed for the determination of vitamin E especially delta-,
gamma- and alpha-tocotrienols in human plasma. The method entailed direct
injection of plasma sample after deproteinization using a 3:2 mixture of
acetonitrile-tetrahydrofuran. The mobile phase comprised 0.5% (v/v) of distilled
water in methanol. Analyses were run at a flow-rate of 1.5 ml/min with the
detector operating at an excitation wavelength of 296 nm and emission wavelength
of 330 nm. This method is specific and sensitive, with a quantification limit of
approximately 40, 34 and 16 ng/ml for alpha-, gamma- and delta-tocotrienol,
respectively. The mean absolute recovery values were about 98% while the within
day and between-day relative standard deviation and percent error values of the
assay method were all less than 12.0% for alpha-, gamma- and delta-tocotrienol.
The calibration curve was linear over a concentration range of 40-2500, 30-4000
and 16-1000 ng/ml for alpha-, gamma- and delta-tocotrienol, respectively.
Application of the method in a bioavailability study for determination of the
above compounds was also demonstrated.
PMID- 10670742
TI - Measurement of hyperforin a constituent of St. John's wort in plasma by high
performance liquid chromatography.
AB - Hyperforin is a constituent of Hypericum perforatum extracts (St. John's wort, H.
perforatum), which have antidepressant action. Hyperforin was extracted from
plasma utilising a solid-phase extraction procedure. Chromatography was performed
by isocratic reversed-phase high-performance liquid chromatography with UV end
point detection. The calibration curve was linear over the range 0.15-3 microg
per ml of plasma. The sensitivity for hyperforin was 4.5 ng on-column. Mean inter
and intra-assay relative standard deviations over the range of the standard
curve were less than 5%. The absolute recovery for hyperforin averaged 97.8%.
PMID- 10670743
TI - Chromatographic approach to study beta-cyclodextrin as a promoter of the
penetration of bifonazole into keratinic tissue.
AB - A high-performance liquid chromatographic method for the determination of
bifonazole in dimethyl sulfoxide solvent was developed to study its penetration
into sheephoof. The analytical method was linear over the concentration range
studied, i.e., from 0.1 mg/ml to 1 mg/ml. The relative standard deviation was
less than 2%. The data obtained showed that complex forming with beta
cyclodextrin greatly improved the penetration of bifonazole.
PMID- 10670744
TI - Determination of 5-fluorouracil in microvolumes of human plasma by solvent
extraction and high-performance liquid chromatography.
AB - In the present study, a new reversed-phase HPLC method has been developed and
validated for the quantitative determination of 5-fluorouracil (5-FU) in human
plasma using only 100-microl samples. The sample extraction and clean-up
procedure involved a simple liquid-liquid extraction after addition of 5
chlorouracil (5-CU), used as internal standard, with 5 ml ethyl acetate.
Chromatographic separations were performed on an Inertsil ODS-3 column (250x4.6
mm ID; 5 microM particle size), eluted with a mobile phase composed of acidified
water (pH 2.0). The column effluent was monitored by UV absorption measurement at
a wavelength of 266 nm. The calibration curves were constructed over a range of
0.20-50.0 microM and were fitted by weighted (1/x) linear regression analysis
using the ratio of peak heights of 5-FU and 5-CU versus concentrations of the
nominal standards. Extraction recoveries over the total range averaged 92 and 93%
for 5-FU and 5-CU, respectively. The lower limit of quantitation was established
at 0.20 microM (approximately 26 ng/ml), with within-run and between-run
precisions of 4.2 and 7.0%, respectively, and an average accuracy of 109.3%. The
within-run and between-run precisions at four tested concentrations analyzed in
quintuplicate over a time period of four days were < 1.4 and < 4.4%,
respectively. The accuracy at the tested concentrations ranged from 98.4 to
102.3%. Compared to previously described validated analytical methods for 5-FU,
our present assay provides equivalent to superior sensitivity, using only
microvolumes of sample.
PMID- 10670745
TI - Quantitative determination of endogenous tetrahydroisoquinoline salsolinol in
peripheral blood mononuclear cells by gas chromatography-mass spectrometry.
AB - Endogenous 1-methyl-1, 2, 3, 4-tetrahydro-6,7-dihydroxyisoquinoline (salsolinol)
could be a potential marker involved in the etiology of alcoholism. The amount of
salsolinol analyzed previously from plasma and urine by different methods depends
on several dietary conditions because nutrition has an important influence on
salsolinol excretion. Whereas plasma salsolinol is influenced by the diet the
salsolinol from peripheral mononuclear cells should be endogenously formed.
Therefore, a method for the quantification of S-and R-salsolinol from lymphocytes
by using gas chromatography-mass spectrometry was developed. The average amount
of salsolinol in 10(6) cells was 1.25 ng corresponding to 2.41 x 10(-5) M and was
shown to be much higher than the plasma salsolinol concentration (2.6 x 10(-9)
M).
PMID- 10670746
TI - Type 1 iodothyronine deiodinase in heart --effects of triiodothyronine and
angiotensin II on its activity and mRNA in cultured rat myocytes.
AB - We previously demonstrated that iodothyronine 5'-deiodination (5'D) activity is
present and increased by triiodothyronine (T3) and angiotensin II (Ang II) in
cultured rat cardiac myocytes. To further elucidate the stimulatory mechanism of
Ang II, we investigated the effect of intracellular Ca2+ and protein kinase C on
myocardial 5'D activity. Moreover, to elucidate the molecular mechanism of the
stimulatory effect of T3 and Ang II, we detected the mRNA levels by means of a
reverse-transcriptase polymerase chain reaction (RT-PCR). 5'D activity was
increased by adding Bay-k 8644, Ca2+ channel agonist and the effect of Bay-k 8644
was completely blocked by nifedipine, a Ca2+ channel antagonist. 12-O
tetradecanoylphorbol-13-acetate, a protein kinase C activator, similarly
stimulated 5'D activity. The addition of a high concentration (20-40 mM) of K+,
which caused the depolarization of the membrane had significant stimulatory
effects on 5'D activity. Type 1 deiodinase (D1) mRNA was evident in myocardial
cells by RT-PCR in a single 758 bp band similar to that in the liver. Cardiac
fibroblasts did not express the D1 mRNA. A significant increase in D1 mRNA was
also evident after adding T3 and Ang II. These findings indicate that 5'D
activity in myocardial cells is increased by activating the voltage sensitive
Ca2+ channel, protein kinase C, and membrane depolarization, and that the D1 mRNA
is present in cardiac myocytes and is increased by T3 and Ang II. This study
therefore suggests that Ang II could affect the action of thyroid hormone on the
heart by increasing the D1 gene expression.
PMID- 10670747
TI - Insulin resistance contributes to carotid arterial wall thickness in patients
with non-insulin-dependent-diabetes mellitus.
AB - The aim of this study was to clarify whether insulin resistance contributes to
atherosclerosis in patients with non-insulin-dependent diabetes mellitus (NIDDM).
Fifty-three NIDDM patients (36 males and 17 females, 53+/-10 years old (mean+/
SD)) were studied. As an index of atherosclerosis, we measured the average
thickness (IMT) as well as basal thickness excluding the maximum thickness and
the height of the maximum thickness of the carotid artery wall. Euglycemic
hyperinsulinemic glucose clamp was conducted for 90 min to evaluate average
glucose infusion rate (GIR) as an index of insulin sensitivity in the peripheral
tissues. For another 180 min after intake of oral glucose load with 0.3 g/kg, the
euglycemic hyperinsulinemic clamp was continued to measure ratio of splanchnic
glucose uptake (SGU) as an index of insulin sensitivity of the liver. The
patients were separated into three activity groups according to the grade of
their leisure-time physical activity. GIR (r = -0.32, p < 0.05) but not SGU
(r=0.139) showed a significant inverse relationship with IMT. Multivariant
regression analysis indicated that age and total cholesterol remain as
independent risk factors for basal thickness and GIR as only independent risk
factor for the height of the maximum thickness. Paralleling the degrees of
habitual exercise (low, moderate, and high active group), GIR was higher (6.19+/
1.02, 6.38+/-1.38, 7.44+/-1.80, respectively) and IMT was lower (1.34+/-0.33 mm,
1.20+/-0.31 mm, and 1.12+/-0.29 mm, respectively) in male NIDDM as well as in
female NIDDM. These data suggest that insulin resistance in the peripheral
tissues but not the splanchnic tissues may independently contribute to carotid
arterial wall thickness and especially to plaque lesion, and that habitual
exercise might reduce insulin resistance leading to attenuation of
atherosclerosis.
PMID- 10670748
TI - A Japanese case with Frasier syndrome caused by the splice junction mutation of
WT1 gene.
AB - The Wilms' tumor suppressor gene, WT1, plays an important role in the development
of the urogenital system and also subsequent normal function of this system.
Recently, the splice mutations in intron 9 of WT1 gene have been detected in
Frasier syndrome, which is characterized by streak gonads, pseudohermaphroditism,
slowly progressive nephropathy and frequent development of gonadoblastoma. Here
to elucidate the molecular basis in a Japanese patient of Frasier syndrome, WT1
gene was analyzed by polymerase-chain-reaction (PCR) and direct sequencing. We
identified the splice junction mutation in intron 9 of WT1, which is recognized
as a mutation hot-spot in intron 9. This finding concludes that 1) the mutation
in intron 9 might be the cause of Frasier syndrome, and 2) the mutation hot-spot
in Japanese and Caucasian patients is similar.
PMID- 10670749
TI - The increase of parathyroid hormone-related peptide and cytokine levels in
synovial fluid of elderly rheumatoid arthritis and osteoarthritis.
AB - We simultaneously measured the concentrations of parathyroid hormone related
peptide (PTHrP) and cytokines in synovial fluid (SF) to clarify the relationship
between PTHrP and cytokine network in the SF of elderly patients with arthritis.
SF was collected from knee joints of five RA patients aged 66+/-11 years old and
nine osteoarthritis (OA) patients aged 80+/-9 years old. PTHrP in SF was measured
by enzyme-linked immunosorbent assay (ELISA), whereas tumor necrosis factor-alpha
(TNF-alpha), interleukin-1beta (IL-1beta), interleukin-2 (IL-2), interleukin-4
(IL-4), interleukin-6 (IL-6) and interleukin-8 (IL-8) in SF were all measured by
ELISA. The PTHrP levels in the SF of RA patients (2.56+/-0.89 pmol/l) were
significantly (p<0.05) higher than those of OA patients (1.66+/-0.17 pmol/l). TNF
alpha, IL-1beta, IL-2 and IL-6 concentrations in SF of RA were also significantly
higher than those in SF of OA (TNF-alpha 22.5+/-14.8 vs 4.8+/-3.0 pg/ml, p<0.01;
IL-1beta 11.8+/-11.4 vs 1.4+/-1.3, p<0.05; IL-2 59.9+/-46.6 vs 12.5+/-8.0 pg/ml,
p<0.05; IL-6 18424+/-8901 vs 3547+/-2948 pg/ml, p<0.01). The concentrations of IL
4 and IL-8 in SF of RA were similar to those of OA. Immunohistochemical studies
revealed the presence of immunoreactive PTHrP in synovial fibroblasts from RA and
OA. Among cytokines, only IL-6 was positively correlated with PTHrP levels in SF
(r=0.685, p<0.01). In the culture of synovial cells from RA and OA, PTHrP was
produced in RA more than OA after phorbol 12-mysistate 13-acetate (TPA)
stimulation. These results indicate that PTHrP and cytokines, especially IL-6,
might be involved in the inflammatory processes of elderly RA and OA. This is the
first study in which PTHrP and cytokine levels were simultaneously examined in
synovial fluid of elderly RA and OA.
PMID- 10670750
TI - A novel mutation of the KAL1 gene in Kallmann syndrome.
AB - Kallmann syndrome is defined by the association of hypogonadotropic hypogonadism
and anosmia, for which three modes of transmission have been described: X-linked,
autosomal recessive and autosomal dominant. The KAL1 gene, responsible for the X
linked form of the disease, has been isolated and its intron-exon organization
determined. We report sequence analysis using PCR-direct sequencing method of the
entire coding region and splice site junctions of the KAL1 gene in three males
with Kallmann syndrome. We found a novel mutation in one case and no mutation in
the other two cases. The mutation consisted of a C to T substitution in exon 1
converting codon 66 (CAG) encoding glutamine into a termination codon
(TAG)/(Q66X). As a consequence of this mutation, the function of the KAL1 protein
consisting of 680 amino acids was severely truncated so as to be consistent with
Kallmann syndrome. As only this patient had unilateral renal hypoplasia among the
three cases, this would suggest the existence of KAL1 gene mutation in this
abnormality.
PMID- 10670751
TI - Effects of intravenous administration of high dose-diethylstilbestrol diphosphate
on serum hormonal levels in patients with hormone-refractory prostate cancer.
AB - The objective of this study was to elucidate the mechanism underlying the further
suppression of serum testosterone (T) by diethylstilbestrol diphosphate (DES-DP)
in patients with prostate cancer refractory to hormonal treatment. These patients
received an LHRH agonist with or without a non-steroidal androgen-receptor
blocker or a gestagen before DES-DP. We measured serum levels of total and free
T, dihydrotestosterone (DHT), estradiol (E2), dehydroepiandrosterone sulfate
(DHEA-S), dehydroepiandrosterone (DHEA), androstenedione, cortisol, aldosterone
before and during intravenous administration of high doses of DES-DP (500 or 1000
mg/day). DES-DP administration suppressed the serum levels of FSH (p=0.04) and
total T (p=0.02), and eliminated free T (p=0.04) and E2 (p=0.04) from serum,
while reducing serum DHEA-S to approximately two-thirds of the pretreatment level
(p=0.03). In contrast, serum levels of SHBG (p=0.02) and cortisol (p=0.02) were
markedly increased after DES-DP administration. The latter had no significant
effect on serum levels of LH, DHT, ACTH, 17alpha-hydroxypregnenolone, 17alpha
hydroxyprogesterone, DHEA, androstenedione, or aldosterone. The results suggest
that the potent suppression of circulating total T by DES-DP is caused, in part,
by the inhibitory effect of DES-DP on serum DHEA-S level. In most patients, high
dose DES-DP treatment completely suppressed the serum level of free T, while
possibly elevating serum SHBG and decreasing serum total T. The mechanisms that
maintain the serum level of serum DHT during DES-DP treatment require further
elucidation.
PMID- 10670752
TI - Serum leptin levels and bioelectrical impedance assessment of body composition in
patients with Graves' disease and hypothyroidism.
AB - We investigated whether thyroid status modulates serum leptin concentrations and
body composition as determined by bioelectric impedance analysis (BIA). The
percent body fat mass (%FM) in male Graves' disease was significantly lower than
that in age- and sex- matched normal subjects, at the levels of 11.4+/-6.4%
(mean+/-SD) vs 19.9+/-9.2% for men (n=12, P<0.05) but not for women (22.6+/-7.6%
vs 24.9+/-13.1%, n=28). In contrast, in female hypothyroidism (n=11) %FM was
significantly higher than that in normal subjects (32.9+/-11.5%, P<0.01). Among
other body composition parameters, the percentage of body water (%BW), and lean
body mass (LBM) were significantly lower in hypothyroid patients, and the ECM
(extracellular mass)/BCM (body cell mass) ratio was significantly (P<0.0001)
increased in Graves' disease which was the result of marked depletion of BCM with
concomitant expansion of ECM. The serum leptin levels were significantly
decreased in male Graves' patients (2.3+/-0.7 ng/ml, P<0.05), whereas in female
Graves' patients (8.8+/-5.9 ng/ml) and patients with hypothyroidism (9.5+/-7.6
ng/ml), the levels were not different from those of normal controls matched for
BMI or %FM. There was a positive correlation between serum leptin levels and %FM
in female Graves' patients (r=0.635, P=0.001) and in hypothyroid patients
(r=0.801, P=0.014) but not in male Graves patients. There was no significant
relationship between serum leptin levels and thyroid hormones, TRAb, or TSAb. In
euthyroid obese subjects there was a positive relationship between serum leptin
levels and serum TSH levels (r=0.37, P<0.01). These results suggest that
hyperthyroidism is characterized by the decreased fat mass and serum leptin
levels in men, but female patients appear to be resistant to the effect of
thyroid hormones. Together with previous reports, thyroid status has a minor role
in the regulation of serum leptin levels.
PMID- 10670753
TI - Human thyrotropin-releasing hormone-associated peptide 3 (hTAP-3) in serum.
AB - Human thyrotropin-releasing hormone (TRH)-associated peptide 3 (hTAP-3), one of
the cryptic peptides resulting from the proteolytic processing of preproTRH to
produce TRH, was measured in human plasma from normal, hyperthyroid, and
hypothyroid subjects. The dilution curve of hTAP-3 immunoreactivity in the serum
paralleled the standard curve of the radioimmunoassay. HPLC analysis revealed a
single strong immunoreactive peak, which corresponded to the authentic peptide,
hTAP-3. The half-life of hTAP-3 in serum was approximately 3.5 min, and the
addition of aprotinin and EDTA completely prevented its degradation. In
hyperthyroid patients, plasma concentrations of hTAP-3 were significantly higher
than those in the control group and hypothyroid patients, but no correlation was
found between its level and that of thyroid hormone. These findings indicate the
existence of intact hTAP-3 in the human serum and increases in plasma hTAP-3
levels in hyperthyroid patients, suggesting that blood hTAP-3 may be derived from
the peripheral organs rather than the hypothalamus.
PMID- 10670754
TI - Hyperphosphatemia accelerates parathyroid cell proliferation and parathyroid
hormone secretion in severe secondary parathyroid hyperplasia.
AB - We studied the role of phosphorus retention in parathyroid cell proliferation and
parathyroid hormone (PTH) oversecretion in severe secondary parathyroid
hyperplasia. Mice transplanted with human parathyroid tissue from a patient who
had undergone parathyroidectomy for severe secondary hyperparathyroidism were
divided into four groups; each group was given a diet with a different phosphorus
content (0.4, 0.7, 1.0, and 1.2%) to alter serum phosphorus concentrations.
Histologic examinations of grafts by hematoxylin-eosin or by bromodeoxyuridine
(BrdU) immunohistochemical staining were performed to assess parathyroid cell
proliferation. Changes in serum phosphorus concentrations unidirectionally
affected PTH secretion from the graft, because human PTH did not cross-react with
mouse PTH. Serum phosphorus concentrations of 1.0P and 1.2P groups were
significantly higher than those of 0.4P and 0.7P groups (p<0.05). Serum
phosphorus concentrations were significantly correlated with the gradient of
human PTH elevation with a coefficient of 0.48 and a p<0.05. Furthermore, serum
phosphorus concentrations and the gradient of human PTH elevation were
significantly higher in mice with BrdU-immunoreactive cells in the parathyroid
graft than in mice without immunoreactive cells in the graft. These results
indicate that uncontrolled hyperphosphatemia may accelerate the proliferation of
parathyroid cells, exacerbating PTH oversecretion.
PMID- 10670755
TI - A case of Hashimoto's thyroiditis with markedly elevated serum thyroglobulin and
evidence of its influence on the measurement of anti-thyroglobulin antibody by
highly sensitive assays.
AB - We present the case of a 66-year-old woman with Hashimoto's thyroiditis, who
showed extremely high concentrations of serum thyroglobulin (Tg). Serum Tg levels
were markedly elevated following a slight elevation of serum thyrotropin (TSH)
(22,000 ng/mL and 11.1 microU/mL, respectively). Although elevated concentrations
of serum Tg declined concomitant with decrease of serum TSH one month later, Tg
concentrations remained high (> 948 ng/mL) even at normal or suppressed TSH
levels. There was no evidence of massive thyroid tissue damage or thyroid tumor.
To our knowledge, there have been no case reports of such high concentrations of
serum Tg (> 2 x 10(4) ng/mL) in the clinical course of Hashimoto's thyroiditis.
Furthermore, we showed evidence that extremely high Tg levels could possibly
influence the measurement of anti-Tg autoantibody using highly sensitive
radioimmunoassays.
PMID- 10670756
TI - cDNA cloning and chromosomal mapping of rat Smad2 and Smad4 and their expression
in cultured rat articular chondrocytes.
AB - Smad proteins are known to transduce signalling of TGF-beta receptor superfamily.
We report here the entire sequences of rat Smad2 and Smad4 which have not been
identified yet. Entire sequences were identified by degenerated polymerase chain
reaction and following phage library screening and 5' RACE. The predicted amino
acid sequences of rat Smad2 and Smad4 are highly conserved among rat, human and
mouse. We also mapped these Smads to chromosome 18q.12.3. Unlike endothelial
cells, TGF-beta1 stimulates articular chondrocyte proliferation as well as
extracellular matrix production, and acts as a repairing agent against cartilage
destruction. Since both Smad2 and Smad4 are essential factors for TGF-beta
signalling, we examined their expression and regulation in cultured articular
chondrocytes. Northern blot analysis showed that TGF-beta1 significantly
increased the mRNA level of Smad2 but not of Smad4 in a dose- and time-dependent
manner, suggesting that the augmentation of TGF-beta1 action is caused by
increasing the expression of the downstream signalling molecule.
PMID- 10670757
TI - Changes in serum leptin concentration during behavioral therapy in obese
children.
AB - To determine the pathophysiological implications of serum leptin level in
obesity, we monitored the changes in serum leptin level during outpatient
treatment with life style modification in children. Fifty-five obese Japanese
children (34 boys and 21 girls; mean age, 9.64 years) were studied. The control
children consisted of 42 nonobese subjects (27 boys and 15 girls). The serum
leptin concentration was 4.35 +/- 0.46 ng/ml (mean +/- SEM) in the control girls
and 2.93 +/- 0.21 ng/ml in the control boys. The serum leptin concentrations in
the obese boys and girls were higher than those in their lean counterparts. The
concentration in the obese boys (16.28 +/- 1.41 ng/ml) was similar to that in the
obese girls (20.33 +/- 2.0 ng/ml). The logarithmic value of serum leptin
concentration at the first blood sampling in obese children was correlated with
percent overweight and percent body fat. In 36 obese children (24 boys and 12
girls) whose serum leptin concentrations were monitored serially during treatment
of obesity, the percent overweight was significantly decreased after the initial
sampling. In each individual, the changes in leptin concentration were roughly
parallel to those in percent overweight. The ratio of the leptin concentration at
the second blood sampling divided by the one at the first sampling in each
individual was closely correlated with the respective delta percent overweight.
These results suggest that the preceding course of obesity determines the serum
leptin level of obese children on longitudinal basis, and that the leptin level
reflects the degree of obesity on cross-sectional basis.
PMID- 10670758
TI - Effect of pregnancy, lactation and weaning on bone mineral density in rats as
determined by dual-energy X-ray absorptiometry.
AB - To elucidate the effect of pregnancy, lactation and weaning on bone mineral
density (BMD) in rats, a longitudinal study was done on the same individuals
measuring BMD by dual-energy X-ray absorptiometry (DXA) and comparing their
profiles with those of nonpregnant controls. Twenty-seven pregnant Wistar rats
which had been mated at 11 weeks old (baseline), lactated during the three weeks
postpartum period and weaned thereafter. Twenty-four rats of the same age served
as nonpregnant controls. BMDs in lumbar spine, distal femur and caudal spine of
all rats were measured weekly from 11 to 22 weeks except for the week of
parturition (14th week). During pregnancy, BMDs of the three sites increased
significantly from the baseline values, but no significant difference was
observed in comparison with the control. After parturition and during lactation,
BMD of the three sites decreased significantly from the pregnant values and
decreased even from baseline values. All the BMD values of the pregnant group
were significantly lower than those of the control group. After weaning, BMDs of
the three sites increased gradually and caught up to the control group at 22
weeks in the lumbar spine and the femur and at 21 weeks in the caudal spine. In
conclusion, pregnancy in itself does not significantly affect maternal BMDs of
rats, although the significant bone mineral loss during lactation is not
completely restored until at least 5 weeks after weaning.
PMID- 10670759
TI - Absence of proteolysis of insulin-like growth factor binding protein-3 in serum
from patients with growth hormone deficiency.
AB - Insulin-like growth factor-I (IGF-I) is predominantly bound to IGF binding
protein-3 (IGFBP-3), and free form of IGF-I (fIGF-I) may be bioactive in the
circulation. Proteolysis of IGFBP-3, as reported in pregnant serum, results in
the lowering of the affinity for IGF-I, thereby increasing the ratio of fIGF-I to
total IGF-I (f/t IGF-I ratio). Conflicting results have been reported regarding
the relationship between the proteolysis and growth hormone (GH)-IGF-I axis.
Proteolysis of IGFBP-3 was previously reported to be present late at night in
serum from pediatric subjects with GH receptor dysfunction (GHRD or "Laron-type
dwarfism"). Recently, it was reported that proteolysis of IGFBP-3 could not be
detected in adult patients with GH deficiency (GHD). The purpose of this study
was to investigate the possible relationship between proteolysis of IGFBP-3 and
GH in patients with GHD including pediatric cases. Here, proteolysis of IGFBP-3
measured by Western immunoblotting (ages 4-25 years; n=11) and f/t IGF-I ratio
measured by immunoradiometric assay (ages 4-25 years; n=10) were studied in
patients with GHD, which is similar to GHRD in terms of lowered GH function.
There was no significant proteolysis of IGFBP-3 in the sera from the 11 patients
with GHD. No proteolysis of IGFBP-3 was observed during a 24 hour period in sera
obtained every two hours from two patients with GHD. f/t IGF-I ratio was not
increased in plasma from the 10 patients with GHD. Our data suggest that
proteolysis of IGFBP-3 is independent of the GH-IGF-I axis.
PMID- 10670760
TI - Troglitazone improves insulin-stimulated glucose utilization associated with an
increased muscle glycogen content in obese Zucker rats.
AB - Recent studies have demonstrated that troglitazone has the capacity to improve
insulin resistance. The present study was undertaken to determine the effect of
troglitazone on in vivo insulin action, the activities of the pyruvate
dehydrogenase (PDH) complex and 3-hydroxyacyl-CoA dehydrogenase (3-HADH) in
muscle, and muscle GLUT-4 and glycogen content in obese and lean Zucker rats.
Rats were fed a normal chow diet with and without troglitazone as a food
admixture (0.2%) for 3 weeks. In vivo insulin action was measured by the
sequential euglycemic clamp technique at two different insulin infusion rates (6
and 30 mU/kg BW/min). At the basal (fasting) state and after the clamp studies,
the activities of PDH complex and 3-HADH, and the amounts of GLUT-4 and glycogen
contained in the red gastrocnemius muscles were determined. Troglitazone
treatment produced a significant rise in the metabolic clearance rate of glucose
(MCR) during the 6-mU/kg BW/min insulin clamp study (19.5+/-3.9 vs 9.9+/-1.5
ml/kg BW/min, mean+/-SE, P<0.05) in obese rats, but not in lean rats.
Troglitazone significantly increased the muscle glycogen content after the clamp
study, compared to non-treated rats, in obese rats (9.9+/-0.5 vs 6.5+/-0.4 mg/g
tissue, P<0.05) and has the tendency to increase the activity state of PDH
complex in obese and lean rats at the fasting state. However, no effect of the
drug on muscle GLUT-4 content was found. These results indicate that troglitazone
may improve insulin sensitivity associated with increased muscle glycogen
content.
PMID- 10670761
TI - A case of ectopic thyroid in lateral neck associated with Graves' disease.
AB - Thyroid follicles in the lateral position of the neck are usually thought to
represent the metastasis of thyroid carcinoma. Here we present a case of a 28
year-old woman with accessory ectopic thyroid associated with Graves' disease.
Despite a history of Graves' disease poorly controlled with large dose
propylthiouracil she was found to be pregnant and artificial abortion was
planned. Thyroid scintigraphy was carried out, which indicated an uptake into the
region above the left lobe as well as into both lobes of the thyroid gland. In
order to control hyperthyroidism and to exclude the possibility of metastasis,
total thyroidectomy with tumor resection was performed before the artificial
abortion. Pathological examinations of the thyroid gland indicated findings
compatible with Graves' disease. The lateral neck mass was revealed to be
composed of nonneoplastic thyroid tissue, showing similar histological findings
to those of the goiter, which were consistent with Graves' disease. Taken
together with several previous reports, it appears that there are some cases with
lateral ectopic thyroid tissue, whose pathogenetic mechanism remains to be
elucidated.
PMID- 10670762
TI - A novel sex-determining region on Y (SRY) missense mutation identified in a 46,XY
female and also in the father.
AB - Mutations in the sex-determining gene SR Y previously identified occur in the 46,
XY females. In this study, we investigated whether the SR Y mutation participates
in the onset of XY sex reversal. Genomic deoxyribonucleic acids (DNA) from five
XY sex-reversed females were analyzed for mutations in SR Y using polymerase
chain reaction (PCR) amplification and subsequent DNA sequencing. One of the 46,
XY females suffered a novel missense mutation at position 306 of SR Y gene,
wherein cytosine was replaced by adenine (CGC-->AGC), resulting in a substitution
of serine for arginine at amino acid position 76 of SR Y protein. This mutation
was located in Helix I of the high-mobility-group (HMG) domain. No other
mutations were found in the remaining regions of the gene. Analysis of the SR Y
gene in her father revealed that he carried the identical mutation version. This
substitution introduces a large basic for a small polar uncharged amino acid
residue in the HMG box. The fact that the father transmits the mutant SR Y copy
to his offspring implies that SR Y mutations do not always occur in association
with sex reversal, even when the ionic environment is altered.
PMID- 10670763
TI - An elderly patient with transient diabetes insipidus associated with lymphocytic
infundibulo-neurohypophysitis.
AB - We present the eldest case ever reported of central diabetes insipidus (DI)
associated with infundibulo-neurohypophysitis. A 77-year old woman, who
complained of recent development of excessive thirst, polyuria and polydipsia,
was referred to our hospital. The daily urine volume was markedly increased to 6
L. DDAVP administration effectively reduced urine volume and increased urine
osmolality. The loading test using high-osmolar sodium chloride showed impaired
excretion of vasopressin discordant with plasma osmolar changes. The anterior
pituitary function was normal. Pituitary magnetic resonance imaging (MRI) showed
thickening of the pituitary stalk and a lack of high-intensity signal of the
neurohypophysis on T1-weighted images, suggestive of lymphocytic infundibulo
neurohypophysitis. The thickness of pituitary stalk on MRI improved 6 months
later. DI was controlled with DDAVP for 40 days. This was followed by
stabilization of the daily urine volume to less than 2.5 L without DDAVP. Our
case is the eldest case of central DI associated with infundibulo
neurohypophysitis. The rapid remission of pituitary changes on MRI provides an
insight that spontaneously partial remission of central DI may occur, resulting
in transient polyuria and polydipsia.
PMID- 10670764
TI - Image analysis method to assess adhesion of Helicobacter pylori to gastric
epithelium using confocal laser scanning microscopy.
AB - We have used confocal scanning microscopy of FITC-labelled bacteria to assess
binding of Helicobacter pylori to stomach sections and to assess the effect of
inhibitors on binding to the Lewis antigens. We have quantified the binding using
an image manipulation package that is readily available on the web. Our results
demonstrate heterogeneity of binding of Helicobacter pylori to tissue sections
and that binding can be inhibited using synthetic Lewis B oligosaccharide.
PMID- 10670765
TI - An enzyme-release assay for the assessment of the lytic activities of complement
or antimicrobial peptides on extracellular Toxoplasma gondii.
AB - A method is described which allows the evaluation of the membrane lytic activity
of either complement or antimicrobial peptides against the extracellular stage of
the human protozoan parasite Toxoplasma gondii. The assay is based on lacZ
transgenic parasites, determining the activity of released cytoplasmic beta
galactosidase into the culture supernatant upon membrane disintegration. This
method was used to evaluate the lytic activities of (i) complement which is a
natural defense mechanism in infected hosts against extracellular parasites, and
(ii) antimicrobial peptides which have not been evaluated against T. gondii
before. The results show that the assay provides a simple and convenient way to
assess the membrane lytic activity of such compounds and that T. gondii, like
other protozoan parasites, is vulnerable to the membrane-lytic effect of
antimicrobial peptides.
PMID- 10670766
TI - Identification of major subgroups of ammonia-oxidizing bacteria in environmental
samples by T-RFLP analysis of amoA PCR products.
AB - A cloning-independent method based on T-RFLP (terminal restriction fragment
length polymorphism) analysis of amoA PCR products was developed to identify
major subgroups of autotrophic ammonia oxidizers of the beta-subclass of the
class Proteobacteria in total community DNA. Based on a database of 28 partial
gene sequences encoding the active-site polypeptide of ammonia monooxygenase
(amoA), defined lengths of terminal restriction fragments (= operational
taxonomic units, OTUs) of amoA were predicted to correlate in TaqI-based T-RFLP
analysis with phylogenetically defined subgroups of ammonia oxidizers. Members of
the genus Nitrosospira showed a specific OTU of 283 bp in length, while a
fragment size of 219 bp was indicative of Nitrosomonas-like sequence types
including N. europaea, N. eutropha, and N. halophila. Two amoA sequence clusters
designated previously as the lineages 'PluBsee' and 'Schohsee' [Rotthauwe, J.-H.,
Witzel, K.-P., Liesack, W., 1997. Appl. Environ. Microbiol. 63, 4704-4712] shared
a TaqI-based OTU with a fragment size of 48 bp, but sequence types of these two
lineages could be differentiated by AluI-based T-RFLP analysis. A survey of
various environmental samples and enrichment cultures by T-RFLP analysis and by
comparative analysis of cloned amoA sequences confirmed the predicted
correlations between distinct OTUs and phylogenetic information. Our data suggest
that amoA-based T-RFLP analysis is a reliable tool to rapidly assess the
complexity of ammonia-oxidizing communities in environmental samples with respect
to the presence of major subgroups, i.e. nitrosospiras versus nitrosomonads.
PMID- 10670767
TI - Using a green fluorescent protein gene-labeled p-nitrophenol-degrading Moraxella
strain to examine the protective effect of alginate encapsulation against
protozoan grazing.
AB - A gfp-labeled p-nitrophenol-degrading Moraxella strain G21 was used to study
grazing of a Tetrahymena thermophila strain in liquid medium. This allowed
visualization of the feeding process. Under an epifluorescent microscope,
individual G21 fluorescent cells could be seen in vacuoles within the protozoans.
Most of the G21 cells appeared to be lysed by T. thermophila and green
fluorescent protein released from the bacteria yielded brightly fluorescent food
vacuoles inside the protozoans, Examination of population dynamics of a mixed
culture of T. thermophila and Moraxella sp. G21 showed that the protozoan reduced
the bacterial density from 7.6 to 5.8 log CFU/ml in 2 days. Encapsulating the
bacteria in alginate prevented grazing by the protozoans and the density of G21
cells in the beads increased steadily from about 8.3 to 8.9 log CFU/ml in 15 days
regardless of the presence of the protozoans.
PMID- 10670768
TI - Comparative study of the abundance of various bacterial morphotypes in an
eutrophic freshwater environment determined by AODC and TEM.
AB - Transmission electron microscopy (TEM) and epifluorescence microscopy were used
to obtain comparative measurements of total bacterial counts, and to enumerate
abundances of various bacterial morphotypes in an eutrophic freshwater habitat.
Although particulate matter would have been expected to interfere with counting
by obscuring large areas of the electron microscope grids, estimates of total
bacterial abundance made by TEM were on average 1.2 times greater than those
obtained using the acridine orange direct counting method (AODC). However, the
precision of the AODC method was greater than that for TEM, with a coefficient of
variation (C.V.) of 4.0% versus 8.8%, respectively. The total bacterial abundance
ranged from 1.1 to 3.2 x 10(6) ml(-1). As was the case for total bacterial
density, the numbers of rod- and vibrio-shaped cells were lower when counted in
the epifluorescence microscope, indicating the presence of potential starvation
forms or ultramicrobacteria. Greatest variations in counts made by TEM and AODC
were found for filamentous and coccoid bacteria. Counts of filamentous bacteria
made by AODC were only about half of those detected by TEM. In contrast, cocci
were on average 1.5 times greater when counted by AODC compared to TEM estimates.
Both counting differences were probably caused by the morphology and low density
of filamentous and coccoid bacteria (1.7 and 1.4 x 10(5) ml(-1), respectively),
which led to an uneven distribution on polycarbonate filters as well as on
electron microscope grids. Besides, cocci might easily be mistaken for large
viral particles when counted by AODC. Hence, the study supports the use of TEM
over AODC for obtaining accurate estimates of total bacterial abundance and
especially bacterial morphotypes in natural waters.
PMID- 10670769
TI - Distinctness of spore and vegetative cellular fatty acid profiles of some aerobic
endospore-forming bacilli.
AB - A gas chromatographic analysis method was employed to determine the cellular
fatty acid (CFA) profiles of spores and vegetative cells of some aerobic
endospore-forming bacilli. The harvests of experimental strains were processed to
obtain pure spores and acquire whole cell fatty acid methyl esters for the
subsequent gas chromatographic analysis, and the corresponding vegetative cells
were set as control. Evaluation of reproducibility of spore CFA components
revealed that, provided under standardized experimental procedure, spore CFA
composition was stable enough for research purposes. Fatty acids recovered in
spores in greater quantities were saturated branched-chain acids containing 15
and 17 carbon atoms, similar to the vegetative cells. Commonly, the proportions
of saturated branched-chain acids in spores were greater than in vegetative
cells. The dendrograms obtained by cluster analysis provided some meaningful
taxonomic information of the experimental strains. The fatty acids analysis of
spores seems to be a promising supplementary tool for the chemotaxonomic research
of aerobic endospore-forming bacilli.
PMID- 10670770
TI - A culture apparatus for maintaining H2 at sub-nanomolar concentrations.
AB - We devised a microbial culture apparatus capable of maintaining sub-nanomolar H2
concentrations. This apparatus provides a method for study of interspecies
hydrogen transfer by externally fulfilling the thermodynamic requirement for low
H2 concentrations, thereby obviating the need for use of cocultures to study some
forms of metabolism. The culture vessel is constructed of glass and operates by
sparging a liquid culture with purified gases, thereby removing H2 as it is
produced. We used the culture apparatus to decouple a syntrophic association in
an ethanol-consuming, methanogenic enrichment culture, allowing ethanol oxidation
to dominate methane production. We also used the culture apparatus to grow pure
cultures of the ethanol-oxidizing, proton-reducing Pelobacter acetylenicus (WoAcy
1), and to study the bioenergetics of growth.
PMID- 10670771
TI - Assessment of the intracellular pH of immobilized and continuously perfused yeast
cells employing fluorescence ratio imaging analysis.
AB - The intracellular pH (pHin) of Saccharomyces cerevisiae was measured employing
fluorescence ratio imaging microscopy (FRIM). The yeast cells were fluorescently
labeled with the pH dependent probe 5(and-6)-carboxyfluorescein (cF) or 5(and-6)
carboxyfluorescein succinimidyl ester (cFSE), and subsequently attached to ferric
nitrate pretreated glass slides. The labeled and adhered cells could still divide
and were metabolically active. Measurement of the pHin was performed during
continuous perfusion of the cells with buffer or medium. Cells labeled with cF
are highly fluorescent and in non-energized cells the pHin could be easily
measured. However, in energized yeast cells cF was accumulated in the vacuoles
and/or exported to the extracellular environment, most likely by an energy
dependent transport system, thus limiting the time period over which the pHin can
be effectively measured. Therefore, cFSE (which conjugates with aliphatic amines
in the cytoplasm) was applied to prevent translocation of fluorescent probe to
the vacuole and/or extracellular environment. The continuous perfusion in
combination with the cFSE labeling of the immobilized cells was successfully
applied to determine the effect of low and high pHin and addition of glucose on
the pHin of individual yeast cells over a long time period.
PMID- 10670772
TI - Use of macroporous polypropylene filter to allow identification of bacteria by
PCR in human fecal samples.
AB - The detection of pathogenic bacteria directly in human fecal specimens by PCR,
requires removal of PCR-inhibitory substances. To investigate whether five
different macroporous filters (polypropylene, nylon, polyester, polyethylene,
fluorocarbon) could retain polysaccharides, major PCR inhibitors, an in vitro
model and human fecal samples were used. The in vitro model consisted of Xanthum
gum solutions (3 mg/ml PBS), a bacterial polysaccharide, to which Helicobacter
pylori cells were added. Fecal samples from healthy volunteers were spiked with
H. pylori and Mycobacterium paratuberculosis cells. Polysaccharide concentrations
were significantly reduced only by the polypropylene but not by the other
filters. Accordingly, both Xanthum gum solutions and spiked fecal specimens
became PCR positive only after filtration with the polypropylene filter. We
conclude that this filter can be used to prepare a bacterial DNA template
suitable for PCR analysis from human feces.
PMID- 10670773
TI - Migraine in childhood--are periodically occurring migraine attacks related to
dynamic changes of cortical information processing?
AB - Amplitudes and habituation of contingent negative variation (CNV) were analyzed
in relation to spontaneously occurring migraine attacks in ten children suffering
from migraine without aura. Recording took place during feedback training and
instrumental conditioning of slow brain potentials. Both the amplitude of the
early CNV component and its habituation deficit increase during the 5 days prior
to a migraine attack, with maximum abnormalities the day before the ictal
episode. Abrupt reduction of the amplitude and normalization of the CNV
habituation were observed during the attack. This study provides evidence for
neurophysiological periodicity in young migraineurs and emphasizes that the time
relative to the migraine attacks must be considered in studies of juvenile
migraine during the headache-free period.
PMID- 10670774
TI - Rat oligodendroglia express c-met and focal adhesion kinase, protein tyrosine
kinases implicated in regulating epithelial cell motility.
AB - Oligodendrocytes, the myelinating cells of the central nervous system, arise from
a profilerating pool of motile progenitor cells. The proliferation and survival
of these cells is dependent on signal transduction via several protein tyrosine
kinases (PTKs) including receptors for fibroblast growth factor -2, the platelet
derived growth factor receptors and the neurotrophin receptor, trkC. We
hypothesized that additional PTKs could also influence oligodendroglial
development. Utilizing RTPCR, we amplified from post-natal day 6 rat
oligodendroglia 17 distinct kinase domain sequences, 14 of which were not
previously known to be expressed by oligodendroglia. Amongst the sequences
identified were the c-met and Fak genes, whose protein products regulate the
motility of other epithelial cell types. Utilizing immunohistochemistry, we
confirmed that both c-met and Fak are expressed by cultured oligodendroglia,
suggesting that these proteins could also be implicated in regulating the
motility of these cells.
PMID- 10670775
TI - Lithium alters mu-opioid receptor expression in the rat brain.
AB - Lithium can potentiate the effects of antidepressant drugs and alters morphine
analgesia and phosphoinositide turnover. Analysis of mu-opioid receptor
immunostaining after chronic lithium administration in rats revealed an increase
in the density of cells expressing mu-opioid receptors in the caudatus-putamen,
the dentate gyrus, the lateral septum and the frontal, parietal and piriform
cortices. These data suggest that mu-opioid receptor expression in the rat
forebrain is altered by in vivo chronic lithium treatment. This could be a
compensatory mechanism, induced in part by the effects of lithium on mu-opioid
receptor transduction mechanism.
PMID- 10670776
TI - A cluster of single nucleotide polymorphisms in the 5'-leader of the human
dopamine D3 receptor gene (DRD3) and its relationship to schizophrenia.
AB - The association between schizophrenia and the Ser9Gly variant of the dopamine D3
receptor gene (DRD3) has been the subject of numerous studies. Under meta
analysis this site, or one or more in linkage disequilibrium with it, appears to
contribute a small increase to the relative risk of schizophrenia. In this study,
768 bp of the 5'-leader region of DRD3 mRNA was screened for polymorphisms to
assess their contribution to the association of DRD3 with schizophrenia. A
cluster of three single nucleotide polymorphisms (SNPs) was identified in tight
linkage disequilibrium with each other and with the Ser9Gly polymorphism. One of
the 5'-leader SNPs encodes a Lys9Glu variant within a 36 amino acid residue
stretch of an upstream open reading frame (uORF). Two common haplotypes are found
in the population examined; one is linked to the Ser9 coding variant and the
other to the Gly9 variant. A panel of 73 schizophrenic patients and 56 matched
controls recruited from the East Anglia region of the United Kingdom was screened
for disease association at these sites. Since the 5'-leader and coding sites are
in tight disequilibrium, the combined genotype of all 4 sites was scored for each
patient. A significant association was seen between disease and the frequency
distribution of these genotypes (chi2 = 13.19, d.f. = 3, P = 0.0042; Cochran
method for sparse cells applied). A 20% excess of one of the heterozygous
genotypes, in which the sequences differ at three of the four SNPs, including
Ser9/Gly9 in the receptor and Lys9/Glu9 in the uORF, was found in the patient
group. An absence of association of disease with the Ser9Gly polymorphism had
previously been reported for this panel. This suggests that these SNPs and the
corresponding coding changes may exert a combined or synergistic effect on
susceptibility to schizophrenia.
PMID- 10670777
TI - Increase of urocortin-like immunoreactivity in the supraoptic nucleus of Dahl
rats given a high salt diet.
AB - Urocortin-like immunoreactivity (Ucn-LI) in the supraoptic nucleus (SON) of Dahl
rats was examined. Dahl salt-sensitive (S) rats fed with a high salt diet
developed hypertension. Numbers of Ucn-LI neurons in the SON in Dahl S on a high
salt diet were markedly increased, compared with those in Dahl salt-resistant (R)
rats on the same. Sporadic Ucn-LI neurons were found in the SON of both Dahl S
and R on a normal diet. Numbers of Ucn-LI neurons in the SON of spontaneously
hypertensive rat (SHR) and stroke-prone SHR, genetic models of hypertension, and
control rats (Sprague-Dawley and Wistar-Kyoto) were similar. These results
suggest that Ucn in the SON is associated with salt loading-induced hypertension
rather than spontaneous hypertension.
PMID- 10670778
TI - Reduced number of striatal neurons expressing preprosomatostatin mRNA in rats
with oral dyskinesias after long-term haloperidol administration.
AB - Neuroleptic-induced oral dyskinesia in rats, a putative analogue to human tardive
dyskinesia, may be due to degeneration within the striatum. Using unbiased
stereological methods, a decreased number of striatal neurons expressing
preprosomatostatin mRNA was observed only in rats that developed pronounced oral
dyskinesias after 30 weeks of haloperidol administration. The amount of
preprosomatostatin mRNA in each striatal neuron, measured in terms of optical
densities of individual neurons, was not affected by haloperidol. A tendency
toward a reduction in the number of NADPH-diaphorase positive neurons was
observed in rats receiving haloperidol. These results indicate that the mechanism
by which neuroleptics induce oral dyskinesias in rats, and perhaps tardive
dyskinesia in humans, involves a functional disruption and possibly damage of a
subpopulation of interneurons in the striatum.
PMID- 10670779
TI - Early extrastriate activity without primary visual cortex in humans.
AB - Damage to the primary visual cortex (V1) destroys the major source of anatomical
input to extrastriate cortical areas (V2, V3, V4 and V5) and produces cortical
blindness--an absence of any sensation of light and colour--in the visual field
contralateral to the side of the lesion. Neuroimaging studies, nevertheless, have
recently demonstrated dorsal and ventral extrastriate activation for stationary
stimuli presented to the blind visual field in the absence of V1 activity in
human subjects. To clarify the moment in time that visual information reaches
extrastriate areas, by means of event-related potentials (ERPs) we tracked the
temporal course of responses to complex visual stimuli (faces) presented in the
blind field of a hemianopic patient. Stimulation of the normal visual field
elicited a positive occipital deflection (P1) at 140 ms. A P1 response was also
observed with stimulation of the blind field, although slightly delayed (20 ms)
and reduced. Its topography and timing demonstrate that early neural activity for
stationary stimuli takes place within extrastriate regions despite V1
denervation.
PMID- 10670780
TI - Harmonic partials facilitate pitch discrimination in humans: electrophysiological
and behavioral evidence.
AB - The effect of the spectral tone structure on pre-attentive and attentive pitch
discrimination was investigated. The mismatch negativity (MMN) component was
recorded from reading subjects to pitch changes of identical magnitude in pure
tones with only one sinusoidal frequency component and in spectrally rich tones
with two additional harmonic partials. In a separate condition, subjects were
asked to indicate detection of pitch change by a button press. The MMN was
elicited with a larger amplitude and shorter latency by change in spectrally rich
tones than by change in pure tones. Furthermore, the subjects' behavioral
responses were more accurate for spectrally rich tones than for sinusoidal tones.
Together these data indicate that pre-attentive and attentive pitch
discrimination is facilitated with spectrally rich sounds in comparison to pure
sinusoidal tones.
PMID- 10670781
TI - Brain-derived neurotrophic factor in patients with frontotemporal dementia.
AB - Brain-derived neurotrophic factor (BDNF) promotes survival and growth of various
nerve cell populations during normal development and following different insults
in the developing and adult brain. BDNF expression is reduced in Alzheimer
disease, but little is known about BDNF expression in other types of dementia.
Frontotemporal dementia (FTD) is a common cause of mental impairment in old age,
which is characterized by neuron loss in the upper cortical layers mainly of the
frontal and temporal cortex. BDNF protein expression has been examined by Western
blotting and immunohistochemistry in the cerebral cortex of individuals affected
by FTD. Examination of pathological samples (n = 8, mean age: 74.7 years; four
men, four women) was conducted in parallel with corresponding samples from age
matched controls (n = 8; mean age: 72.6 years; three men, five women). Post
mortem delay was between 2 and 6 h. Preserved BDNF expression, as revealed by
Western blotting, has been observed in the frontal and temporal cortices of
patients with FTD. Furthermore, immunohistochemistry has disclosed maintained
BDNF immunoreactivity in surviving neurons of the upper cellular layers, as well
as in neurons of the inner cellular layers in FTD. These results show that FTD is
not associated with a decay of BDNF in cortical neurons, and therefore, that BDNF
is differentially regulated in diseases causing dementia.
PMID- 10670782
TI - Characterization of [3H]mazindol binding sites in cultured monkey amniotic
epithelial cells.
AB - Our previous studies showed that monkey amniotic epithelial cells (MAEC)
synthesize and release catecholamines and possess D1 and D2 dopamine (DA)
receptors (Elwan, M.A., Ishii, T., Ono, F. and Sakuragawa, N., Evidence for the
presence of dopamine D1 receptor mRNA and binding sites in monkey amniotic
epithelial cells. Neurosci. Lett., 262 (1999) 9-12; Elwan, M.A., Ishii, T. and
Sakuragawa, N., Detection of dopamine D2 receptor mRNA and binding sites in
monkey amniotic epithelial cells. J. Neurosci. Res., 56 (1999) 316-322; Elwan,
M.A., Thangavel, R., Ono, F. and Sakuragawa, N., Synthesis and release of
catecholamines by cultured monkey amniotic epithelial cells. J. Neurosci. Res.,
53 (1998) 107-113). In the present study we tested the presence of DA transporter
(DAT) in MAEC using radioligand binding experiments. Saturation studies showed
that [3H]mazindol binds to a high affinity site with K(D) and Bmax values of 7.85
+/- 1.25 nM and 123.22 +/- 18.34 fmol/mg protein, respectively. Competition
studies indicated that selective DAT inhibitors are potent displacers of
[3H]mazindol binding, compared to inhibitors of other types of transporters. The
rank order of potency of the competing drugs is consistent with the pharmacology
of DAT. These results provide, for the first time, clear evidence that MAEC
natively possess DAT binding sites and suggest that MAEC may provide a potential
primate cell model to study DA release and uptake processes and to explore new
drugs active at this site.
PMID- 10670783
TI - No evidence for long CAG/CTG repeats in families with spastic paraplegia linked
to chromosome 2p21-24.
AB - Autosomal dominant familial spastic paraplegia (AD-FSP) is a genetically
heterogeneous, neurodegenerative disorder characterized by spasticity and
progressive weakness in the lower limbs. Anticipation has been suggested to occur
and an association between expanded CAG/CTG repeats and AD-FSP linked to the SPG4
locus (2p21-p24) has been described. In this study, 42 affected individuals from
six SPG4 families were screened for expanded CAG/CTG repeats using the repeat
expansion detection (RED) method. Large RED products (range 180-240 nucleotides)
corresponding in size to repeats at the ERDA1 locus were detected in eight
patients and at the CTG 18.1 locus in one patient. The large ERDA1 repeats did
not segregate with the disorder within families. Mean age at onset and index of
severity were not significantly different between patients with or without
expanded RED products. Furthermore, no abnormal proteins were found by Western
blot in 15 selected patient samples as compared with controls, using the 1C2
antibody, which detects long polyglutamine stretches. Thus, in contrast to
previous reports, our study provides evidence against the hypothesis that a large
translated CAG repeat expansion is the basis of SPG4. We propose that mechanisms
other than large pathogenic CAG/CTG repeats may account for the disease in the
SPG4 families tested here.
PMID- 10670784
TI - Intraseptal infusions of 8-OH-DPAT in the rat impairs water-maze performances:
effects on memory or anxiety?
AB - In the rat, 5-HT1A receptors are found on medial septal cholinergic neurons. The
effects of intraseptal infusions of the 5-HT1A receptor agonist 8-OH-DPAT (8
hydroxy-2-(di-n-propyl-amino)-tertralin) were assessed on reference memory
performances in a water maze. Compared with vehicle infusions, 0.5 and 4 microg
of 8-OH-DPAT significantly impaired (but did not prevent) acquisition of the task
and probe-trial performances. The results suggest that activation of 5-TH1A
receptors in the (medial) septal area impairs spatial learning, perhaps directly
by reducing the hippocampal cholinergic tonus, or indirectly by an effect on
anxiety.
PMID- 10670785
TI - Effects of extracellular Ca2+ on membrane and seal resistance in patch-clamped
rat thalamic and sensory ganglion neurons.
AB - We studied the effects of [Ca2+]ext changes on seal resistance in patch-clamp
experiments. Recordings were made on rat peripheral and thalamic neurons.
Increasing [Ca2+]ext from 0.5 to 4.5 mM, reduced the ionic currents evoked at
potentials from -100 to +50 mV, in cell-attached recordings, in all the neurons
tested. The effect was greater at negative potentials. The change in seal
conductance (deltaG) decreased with higher resistance seals and became very low
over 1 Gohm (<0.5 nS). However, the ratio deltaG/G(0.5 Ca2+) rose from close to 0
up to 0.6, indicating that Ca2+ has a stronger effect when the microelectrode and
the membrane are sealed more tightly. These findings suggest that changes in seal
resistance may be misleading in experiments in which extracellular Ca2+ changes
are used.
PMID- 10670786
TI - Gender and age-related variation in adenylyl cyclase activity in the human
prefrontal cortex, hippocampus and dorsal raphe nuclei.
AB - The influence of gender and age on adenylyl cyclase activity was investigated,
through a Dowex-alumina double step chromatographic procedure, in the prefrontal
cortex, hippocampus and dorsal raphe nuclei obtained from autopsy cadavers.
Results showed that forskolin-stimulated enzyme activity in raphe nuclei was
greater in men than in women; a region-dependent rank order of basal, forskolin
induced adenylyl cyclase activity and percentage forskolin-stimulation was
observed in women only. Lastly, basal values correlated positively with forskolin
stimulated adenylyl cyclase activity in all areas except the prefrontal cortex of
the male subjects. Positive significant correlations were also found between both
forskolin-stimulated enzyme activity and percentage forskolin stimulation and
aging in the prefrontal cortex. Overall, the findings suggest that sex and/or age
related differences in brain adenylyl cyclase vary from one cerebral region to
the other.
PMID- 10670787
TI - Target cells of apoptosis in the adult murine dentate gyrus and O4
immunoreactivity after ionizing radiation.
AB - The occurrence of radiation-induced apoptosis and the determination of target
cells were investigated by using the TdT-mediated dUTP-biotin nick end labeling
assay and immunohistochemical analyses. The O4 immunoreactivity, an
oligodendrocytes surface antigen, was also evaluated by using western blotting
analysis. C57BL/6J adult female mice were subjected to single dose irradiation of
10 Gy. Eight hours after irradiation, the most significant increase of apoptotic
cells was detected in the subgranular zone and the hilus of the dentate gyrus.
The target cells of radiation-induced apoptosis are the subgranular progenitor
cells and the oligodendrocytes in the hilus. The amount of the O4
immunoreactivity, a marker for premature oligodendrocytes, was unchanged until 8
h but enhanced after 12 h of irradiation. These results are the first to show the
increase of the O4 immunoreactivity after irradiation and may be associated with
the pathogenesis of radiation injury.
PMID- 10670788
TI - Evidence that N-terminal fragments of nociceptin modulate nociceptin-induced
scratching, biting and licking in mice.
AB - The intrathecal (i.t.) injection of 3.0 fmol nociceptin (orphanin FQ) elicited
scratching, biting and licking responses in mice. N-terminal fragments of
nociceptin, nociceptin (1-7), nociceptin (1-9) and nociceptin (1-13), induced no
characteristic behavioral response. When these N-terminal fragments of nociceptin
were injected simultaneously with nociceptin, the behavioral response induced by
nociceptin was reduced dose-dependently. Nociceptin (1-13) was much more potent
than nociceptin (1-7) and nociceptin (1-9) and antagonized nociceptin-induced
response at equimolar doses. No significant effects of the N-terminal fragments
were observed against the scratching, biting and licking response elicited by
i.t. administration of substance P or N-methyl-D-aspartate. These results suggest
that N-terminal fragments formed endogenously in the spinal cord may have an
antagonistic effect on nociceptin-induced behavioral responses.
PMID- 10670789
TI - S-100 protein-immunoreactive structures in the brains of the elasmobranchs
Scyliorhinus torazame and Mustelus manazo.
AB - S-100 protein-immunoreactive structures were investigated in the brains of two
species of elasmobranchs, Scyliorhinus torazame and Mustelus manazo. In both
species, immunoreactivity for S-100 protein was seen widely in the brain. It was
localized in astrocytes and tanycytes; superficial glial membrane, vascular
endfeet, and radial fibers were recognized clearly. However, no immunoreactivity
was found in the ependymal cells of non-tanycyte type, which were located in the
choroidal plexus, subcommissural organ, and saccus vasculosus. No neuronal cells
showed S-100 protein immunoreactivity. Immunoelectron microscopy revealed that
the antigen was present diffusely in the cytoplasmic matrix of the cells and also
associated with the plasma membrane, outer membrane of mitochondria, and
microtubule-like components.
PMID- 10670790
TI - Post-perfusion syndrome and disturbed microcirculation after cardiac surgery: the
role of angiotensin-converting-enzyme inhibitors.
AB - BACKGROUND: The sympathoadrenal and the renin-angiotensin system (RAS) are
involved in blood pressure regulation. They are known to be activated during
cardiac surgery. We investigated the influence of preoperative RAS-blockade using
angiotensin-converting-enzyme inhibitors (ACEI) on hemodynamic variables and on
the perioperative need for exogenous catecholamines. METHODS: 240 patients
undergoing coronary artery bypass grafting (CABG) or valve surgery were divided
into three matched groups (group A: pre- and postoperative ACEI; group B: ACEI
only pre-, not postoperatively; group C: no ACEI). In these three groups we
analyzed hemodynamic variables, the need for catecholamines and the incidence of
a "post-perfusion syndrome" or systemic inflammatory response syndrome (SIRS)
with impaired microcirculation. RESULTS: There were significant differences in
the intra- and postoperative need for catecholamines in groups A and B compared
to C (intraop. A: 35%, B: 35%, C: 15%; postop. A: 21.2%, B: 16.2%, C: 10%) (p <
0.05). In the ACEI groups (A and B) there were 9 patients with a postoperative
SIRS, only 2 cases in group C. Furthermore 4 patients of group B suffered from
disturbances of the intestinal microcirculation postoperatively. CONCLUSIONS:
Long-term ACEI treatment before cardiac surgery raises the perioperative need for
catecholamines. Patients with preoperative long-term use of ACEI who do not
receive ACEI postoperatively face an increased risk of impaired microcirculation.
The inhibition of angiotensin-II (AT II) generation causes the vasodilatatory
effects of ACEI, and could be one reason for a post-perfusion syndrome or a SIRS.
PMID- 10670791
TI - Oral administration of the dopamine prodrug docarpamine shortens need for drip
infusion of dopamine in patients with low cardiac output syndrome after cardiac
surgery.
AB - BACKGROUND: Docarpamine (DOC) is a dopamine prodrug which can be orally
administered. It has been found that oral docarpamine transforms into dopamine in
vivo, and increases cardiac output and renal blood flow as effectively as
intravenous dopamine. METHODS: We reviewed the records of 26 patients who had
developed low cardiac output syndrome (LOS) after cardiac surgery and received
docarpamine during the early postoperative course. Five patients discontinued
docarpamine within 2 days due to arrhythmia. There were 3 hospital deaths. The
remaining 18 patients were divided into two groups according to the timing of
docarpamine administration. In group A docarpamine was administered during and
after weaning from intravenous catecholamines, in group B only on demand after
weaning from intravenous catecholamines. RESULTS: There were 12 patients in group
A and 6 in group B, and the severity of LOS was relatively milder in group B than
in group A. Stable hemodynamics and sufficient daily urinary output were
maintained by oral administration of DOC in both groups just as well as by drip
infusion of catecholamines. CONCLUSION: Sinse continuous drip infusion of
catecholamine commonly slows recovery in LOS patients, it is considered that
switching from drip infusion of catecholamines to oral DOC administration is safe
and useful for earlier recovery in LOS patients after cardiac surgery.
PMID- 10670792
TI - Quadrileaflet stentless mitral valve replacement.
AB - BACKGROUND: The study evaluates clinical results and hemodynamic parameters one
year after implantation of a stentless quadrileaflet mitral valve (QMV). METHODS:
Since August 1997 28 patients received the QMV, patient age was 69 +/- 8 years;
13 had predominant mitral stenosis and 15 incompetence, preoperative NYHA
functional class was III or IV and cardiac index 1.8 +/- 0.6 L/min/m2. RESULTS:
Surgery was performed using a conventional (25) or a minimally invasive approach
(3). 20 patients received a medium and 8 a large-size prosthesis, crossclamp time
was 58 +/- 19 min. Additional procedures were myocardial revascularization in
four, tricuspid repair in two, and left-atrial radiofrequency ablation to restore
sinus rhythm in six patients. Perioperative mortality (1) was not valve-related.
All other patients were discharged on time. At postoperative, 6-, and 12-months
follow-up mean transvalvular pressure gradients were 4.2 +/- 1.5 / 4 +/- 0.9/ 3.8
+/- 1.4 mmHg and mitral valve orifice area index was 1.5 +/- 0.3 / 1.6 +/- 0.3 /
1.6 +/- 0.4, NYHA class was I or II. CONCLUSIONS: The QMV is well suited for
mitral valve replacement. The anulo-ventricular continuity is preserved and the
QMV function resembles native mitral valve function. If its performance is
maintained in the long term the QMV may be the mitral prosthesis of choice.
PMID- 10670793
TI - Perioperative factors influencing interleukin-10 release under cardiopulmonary
bypass.
AB - BACKGROUND: The cytokine response to cardiopulmonary bypass (CPB) is complex and
can be modified. Among several mediators, the anti-inflammatory interleukin-10
(IL-10, 'cytokine-secretion inhibitory factor') is particularly interesting
because of its ability to counteract pro-inflammatory cytokines triggering
endothelial and leukocyte activation in the immediate immune response to CPB. On
the other hand, during the delayed phase of the immune response, IL-10 may act as
a promotor of immunodeficiency in complicated courses. Therefore, it is of
interest to investigate special conditions of CPB that may influence the extent
of perioperative release of IL-10. METHODS: We analyzed 20 continuously
registered parameters during CPB, including an analysis of subgroups in the case
of application of aprotinin or steroids. 30 consecutive adult patients with
coronary artery disease (CAD) and normal left-ventricular function undergoing
elective CABG were prospectively studied. Arterial blood was sampled
perioperatively and levels of IL-10 were determined using ELISA tests. For
analysis, the time point of maximum IL-10 release was selected (30 min after end
of CPB). Simultaneously, CPB-registration protocols were analyzed concerning
standard parameters. RESULTS: We could state an exponential relationship between
IL-10 levels 30 min after end of CPB and the ischemia time (r = 0.76), duration
of CPB (r = 0.73) and the extent of negative base excess (BE, r = 0.66) in all
subgroups. An inverse relationship could be seen between IL-10 plasma levels and
venous O2 saturation: low values for O2 saturation correlated with high IL-10
levels as did low mean arterial pressure (MAP). Hypothermia reduced IL-10 release
(r = 0.80), whereas a long duration correlated with high IL-10 release (r =
0.67). In the case of longer duration of hypothermia, the protective effect
vanished. CONCLUSIONS: The results show a significant rise for IL-10 early after
starting CPB. Low values for venous O2 saturation and low MAP correlated with
high IL-10 levels. A good correlation could be seen between IL-10 plasma levels
and the duration of CPB, ischemia time, and negative base excess. Because of the
ability of persisting IL-10 production to induce a higher incidence of septic
complications, all actions for maintaining an optimum of perfusion and
oxygenation play an important role.
PMID- 10670794
TI - A new diagnostic procedure for assessing intracardiac flow disturbances in
patients with heart valve disease.
AB - BACKGROUND: Until now no diagnostic technique was available for the three
dimensional (3D) study of intracardiac blood flow abnormalities in patients with
heart valve disease. 3D color Doppler is a new diagnostic technique first
developed at our institution. METHODS: The 3D reconstructions of the blood flow
velocity data have been obtained from conventional multiplanar transesophageal or
transthoracic Doppler echocardiographic examinations. We analyzed 111
reconstructions of color Doppler data obtained from 85 patients with different
heart valve diseases who underwent intraoperative transesophageal
echocardiography. Sixty-nine patients had a significant mitral regurgitation, 7
mitral stenosis, 9 aortic regurgitation, 12 aortic stenosis, 14 tricuspid
regurgitation. Three patients had pulmonary regurgitation associated with mitral
valve disease. RESULTS: 3D color Doppler disclosed the complex spatial spreading
of the blood flow abnormalities caused by heart valve disease. New patterns of
intracardiac blood flow disturbances could be observed and classified.
CONCLUSIONS: This paper shows the first clinical applications of 3D color Doppler
in patients with heart valve disease. The new insights derived from the 3D study
of intracardiac blood flow dynamics revealed a great impact of this technique on
the clinical management of patients with heart valve disease.
PMID- 10670796
TI - Systemic blood pressure and cerebral blood flow velocity during carotid surgery.
AB - BACKGROUND: To evaluate the effect of mean arterial blood pressure (MAP) on
cerebral perfusion during carotid surgery, we investigated blood flow velocity in
the middle cerebral (Vs,mca) using transcranial Doppler ultrasonography (TCD).
METHODS: During carotid crossclamping, treatment included either phenylephrine
induced hypertension without shunting (Group XC; n = 11) or insertion of a shunt
(Group S; n = 12). RESULTS: Increasing MAP in Group XC before crossclamping (81 +
/-13 mmHg to 107 +/- 12 mmHg) caused an increase of Vs,mca (59 +/- 17 cm/s to 75
+/- 20 cm/s; p < 0.001). During crossclamping without a shunt, Vs,mca was not
dependent on MAP, and was reduced (mean 47 +/- 24 cm/s) in relation to preclamp
values. In Group S, Vs,mca was always dependent on MAP and the preclamp velocity
was maintained (before shunt: 75 +/- 26 cm/sec; during shunt: 79 +/- 30 cm/sec).
CONCLUSIONS: Although we found an impaired cerebral autoregulation, Vs,mca was
independent of MAP during carotid crossclamping. Thus, TCD measurements have to
be interpreted with caution during crossclamping, and the effect of induced
hypertension has to be confirmed with more invasive measures of cerebral blood
flow.
PMID- 10670795
TI - Cardiac surgery in patients with previous carcinoma of the breast and mediastinal
irradiation: is the internal thoracic artery graft obsolete?
AB - BACKGROUND: The increasing number of patients of more advanced age undergoing
cardiac surgery means the number of those with previous curative (relapse free)
mastectomy and irradiation of the chest is also increasing. A higher incidence of
postoperative complications such as sternal infection in these patients is
considered possible. Furthermore the question of whether mediastinal irradiation
leads to a relevant internal thoracic artery (ITA) gaft damage remains unclear.
In this context the benefit of arterial revascularization (CABG) using one or
both ITAs is not sufficiently proven by data available from clinical studies.
METHOD: 70 patients (49-85 years) with previous mastectomy or Hodgkin/non
Hodgkin's disease and mediastinal irradiation underwent CABG (n = 59) or an
aortic valve replacement (AVR, n = 11). 20 patients received bilateral internal
thoracic artery grafts, 34 a single internal thoracic artery graft, and in 16
patients an internal thoracic artery was not used. Perioperative data and data
concerning postoperative complications such as mortality, myocardial infarction,
and sternal infection or refixation was gathered and compared with all other
patients receiving CABG (n = 5102). An histological investigation of ITA segments
was done in 12 patients. RESULTS: There was no significant enhancement of the
perioperative risk in comparison with other patients of a corresponding age
group. Internal thoracic artery damage induced by irradiation was not present.
There was no increased incidence of sternal instability requiring refixation
observed. CONCLUSION: In the patient cohort investigated there is in general no
need for restrictive use of the ITA in CABG.
PMID- 10670797
TI - A human heterotopic transplant on the beating heart: an interim report of a
successful technique performed at Kocaeli University.
AB - Heterotopic heart transplantation is still indicated in selected patients mainly
with pulmonary vascular bed problems. Cardio-pulmonary bypass (CPB) has well
known deleterious effects on the pulmonary vascular bed due to leukocyte
sequestration as well as on the immune response of the patients. Also the
negative effects of the cardioplegia on the native heart is another drawback of
the classical heterotopic heart transplantation with the use of CPB. We want to
present our new implantation technique for heterotopic heart transplantation
without CPB, used successfully in our institution at the Kocaeli University on a
patient with resistant pulmonary hypertension and dilated cardiomyopathy.
PMID- 10670798
TI - Simultaneous coronary artery bypass grafting and transmyocardial laser
revascularization through a small left thoracotomy.
AB - We report a patient in whom coronary artery bypass grafting with the left
internal mammary artery to the left anterior descending coronary artery and laser
transmyocardial revascularization were simultaneously performed through a left
small thoracotomy. The patient recovered uneventfully and 9 months following
surgery he is free of angina and has increased effort tolerance. This case
underlines the feasibility of combining these two minimally invasive procedures
through the same approach in selected patients.
PMID- 10670800
TI - Respiratory insufficiency caused by an aneurysm with multiple vascular lesions.
AB - A 71-year-old woman, who presented tracheobronchial obstruction caused by a
thoracic aortic aneurysm, was admitted to our institution. Although she had
multiple cerebral infarctions, old myocardial infarction, bilateral iliofemoral
atherosclerotic lesions with abdominal aortic aneurysm, and superior vena cava
syndrome, aneurysmectomy was undertaken in order to rescue her from respiratory
insufficiency. The operation successfully relieved her of exertional dyspnea and
dysphagia.
PMID- 10670799
TI - Successful streptokinase lysis of a right-atrial thrombus in a heart-transplant
recipient.
AB - This report describes a mobile right-atrial thrombus formation diagnosed by
transthoracic echocardiography in a 22-year-old patient seven months after
orthotopic heart transplantation. To prevent embolic complication, systemic
streptokinase lysis was performed over 48 hours. Echocardiographic control
examinations have shown that this therapy completely removed the thrombus.
PMID- 10670801
TI - Tracheobronchial rupture after emergency intubation.
AB - Iatrogenic injuries of the trachea are rare. We report a case of tracheobronchial
rupture in a 77-year-old woman after emergency intubation. Early bronchoscopy
showed a rupture of the posterior wall of the trachea into the right main
bronchus with a total length of 9.5 cm. A right thoracotomy was performed and the
tracheal rupture was managed successfully by primary suture. Surgical treatment
and possible causes of this lesion are discussed with reference to the
literature.
PMID- 10670802
TI - A surgical management of aortic insufficiency concomitant with mediastinal well
differentiated liposarcoma.
AB - We present a rare case of a mediastinal liposarcoma concomitant with aortic
insufficiency due to myxoid degeneration of the aortic valve. Because the
patient's left ventricle was in moderate dilatation and a posterolateral
thoracotomy combined with median sternotomy was required in order to perform a
complete resection of a mediastinal liposarcoma, it was decided to carry out
aortic valve surgery and tumor excision in one operation.
PMID- 10670803
TI - Carbon dioxide insufflation aids video-assisted thoracic surgery in a young
child.
AB - A 3-year-old girl with pectus excavatum successfully underwent exploration using
video-assisted thoracic surgery. A complete pericardial defect was identified.
The lung was kept totally collapsed during the procedure using low-flow (1
L/min), low-pressure (7 mmHg) carbon dioxide insufflation. This technique is
expected to be a safe adjunct to thoracoscopic procedures in infants and small
children.
PMID- 10670804
TI - A congenital defect of the pericardium.
AB - Ten patients with congenital defects of the pericardium were treated in
Departments of Cardiac Surgery, Silesian School of Medicine in Zabrze and
Katowice between 1989 and 1998. There were eight children and two adults, eight
males and two females. In each case the pericardial defect was discovered
intraoperatively during surgery for congenital heart defect. There were no cases
with clinical symptoms that could be clearly related to the defect of the
pericardial sac. In the case of a child with a complete absence of the left
pericardial wall the heart was significantly rotated contrary to the defect. The
final outcome of the congenital heart defect surgery was satisfactory in each
case. An abbreviated historical review of the diagnosis and treatment of the
pericardial defects is presented with special attention placed on therapeutic
management. Surgical correction of pericardial defects is concluded to be
justified in patients with clinical symptoms. In most cases pericardial defects
are discovered intraoperatively, but when they are large the said defects do not
require any treatment.
PMID- 10670805
TI - Current practice of peri- and postoperative antibiotic therapy in cardiac surgery
in Germany. Working Group on Cardiothoracic Surgical Intensive Care Medicine of
the German Society for Thoracic and Cardiovascular Surgery.
AB - BACKGROUND: The increasing development of antimicrobial resistance of common
bacterial pathogens presents one of the most significant challenges to clinical
medicine, particularly intensive care medicine. One factor which has contributed
to this development is the (over)use of antibiotic treatment. Therefore the
objective of this study was to scrutinize the current practice of empiric
antibiotic therapy in cardiac surgery in Germany for 1) perioperative prophylaxis
and 2) postoperative therapy prior to the availability of susceptibility patterns
for the infecting pathogen. METHODS: A questionnaire was sent to all centers
performing cardiac surgery in Germany. Questions referred to drugs used as well
as dosage, homogeneity and duration of antibiotic prophylaxis, time and/or reason
for changing this regimen, drugs used for first-, second-, and third-line empiric
postoperative antibiotic treatment, and homogeneity of antibiotic usage. RESULTS:
All but 3 institutions (96.3%) answered. 1. Perioperative prophylaxis: All but 4
centers (94%) use first- (n = 32 = 43%) or second-generation cephalosporins (n =
38 = 51%) most commonly for 24 hours (n = 60 = 81%). Prophylaxis never exceeds 3
days. 74% of all institutions (n = 55) use the same antimicrobial agent for all
cardiac procedures performed, while 26% (n = 19) change their regimen in selected
patient groups, most commonly for heart transplantation. The entire prophylaxis
is changed mainly according to susceptibility patterns (n = 63 = 85%), 7 centers
(10%) change according to a fixed time schedule, while 4 institutions (5%) never
change the antimicrobial drug. 2. Empiric postoperative therapy: A total of 29
different antibiotics out of 8 subclasses are used. No major differences between
1st-, 2nd-, and 3rd-line therapy could be detected, with the exception of a
decreasing usage of beta-lactams (carbapenems excluded) from 60% in 1st-line to
23% in 3rd-line therapy and an increasing usage of glycopeptides from 5% in 1st
line to 18% in 3rd-line therapy. 41 institutions (55%) use the same antibiotic
regimen on the intensive care unit and the normal ward, 9 centers (12%) use the
same drug for perioperative prophylaxis and postoperative therapy, and 12
institutions (16%) prescribe a combination therapy. CONCLUSIONS: Perioperative
prophylaxis in cardiac surgery in Germany is performed on a relatively uniform
basis and at low cost. The heterogeneity of antibiotic regimens for postoperative
therapy may indicate the need for recommendations and/or guidelines for this type
of treatment. The indications for the usage of reserve antibiotics, e.g.
vancomycin, implying the possible risk of creating pathogens with untreatable
resistance patterns, as well as strategies aimed at preventing the development of
resistance should be the subject of further discussions.
PMID- 10670806
TI - Kinetic study of the mass transfer of bovine serum albumin in anion-exchange
chromatography.
AB - A kinetic study was made on the mass transfer phenomena of bovine serum albumin
(BSA) in two different anion-exchange columns (Resource-Q and TSK-GEL-DEAE-5PW).
The analysis of the concentration dependence of the lumped mass transfer rate
coefficient (km,L) provided the information about the kinetics of the several
mass transfer processes in the columns and the anion exchangers, i.e., the axial
dispersion, the fluid-to-particle mass transfer, the intraparticle diffusion, and
the adsorption/desorption. In the Resource-Q column, the intraparticle diffusion
had a dominant contribution to the band broadening compared with those of the
other processes. The surface diffusion coefficient (Ds) of BSA showed a positive
concentration dependence, by which the linear dependence of km,L on the BSA
concentration seemed to be interpreted. On the other hand, in the TSK-GEL-DEAE
5PW column, the contribution of the adsorption/desorption was also important and
almost same as that due to the intraparticle diffusion. There are some
differences between the intrinsic properties of the mass transfer kinetics inside
the two anion exchangers. It was likely that the positive concentration
dependence of Ds was explained by the heterogeneous surface model.
PMID- 10670807
TI - Synthesis of a silica-bonded bovine serum albumin s-triazine chiral stationary
phase for high-performance liquid chromatographic resolution of enantiomers.
AB - A novel method of synthesizing protein chiral stationary phase (protein-CSP) is
proposed with 2,4,6-trichloro-1,3,5-triazine as the activator. The bovine serum
albumin (BSA) based chiral columns (150 x 4.6 mm I.D.) were prepared successfully
within 8 h. With tryptophan as the probe solute, it was observed that the BSA
immobilized by this method had a better ability to distinguish enantiomers than
that activated by glutaric dialdehyde. This may be due to the well-maintained BSA
conformation and the larger amount of BSA immobilized on the silica gel. The BSA
CSP prepared by this method was relatively stable under experimental conditions,
and the resolution of 13 chiral compounds was achieved. The coupling reaction in
this method is mild, reliable and reproducible; it is also suitable for the
immobilization of various biopolymers in the preparation of bioreactor, biosensor
and affinity chromatography columns.
PMID- 10670808
TI - Comparison of the enantioseparation of racemic uridine analogs on Whelk-O 1 and
ChiralPak-AD columns.
AB - The commercially available, brush-type (S,S)-Whelk-O 1 chiral stationary phase
(CSP) has been used to separate 10 racemates of structurally related uridine
analogs, potentially anti-viral agents, under various mobile phase compositions,
using various temperatures. The enantioseparation was evaluated by comparing the
Whelk-O 1 column performance with that of ChiralPak-AD column, reported
previously. The comparison involved the role of some distinctive structural
features of the racemates, type and composition of the solvent modifiers, as well
as effect of temperature on the chiral discrimination. Despite the fact that both
columns separate almost all the uridine analogs, significant differences were
observed in their chiral recognition, as revealed from their retention,
selectivity, resolution and elution order. The chiral recognition processes,
responsible for enantioseparation on the Whelk-O 1 column, were relatively more
systematic and easier to manipulate than on ChiralPak-AD column.
Enantioseparation on the latter are of more complex nature and frequently gave
results that were contradictory to the expectations. On the other hand, the
performance in the ChiralPak-AD column was superior to that of the Whelk-O 1
column. Limitations in column handling and maintenance (pressure and
temperatures) as well as limited solvent choice lead to the preference of the
Whelk-O 1 column, in spite of its lower (but adequate) performance.
PMID- 10670809
TI - Tandem solid-phase extraction of atrazine ozonation products in water.
AB - The preconcentration of aqueous solutions containing atrazine degradation
products was investigated using solid-phase extraction on octadecyl and cation
exchanger silica phases. The retention and elution steps were studied and
evaluated separately in order to define and optimize the critical experimental
parameters involved. A strategy which combines sequentially both phases is
proposed to fractionate compounds into two groups of increasing polarities:
firstly, the native pesticide, hydroxyatrazine and most chlorotriazines on
octadecyl support, and secondly monodealkylated hydroxytriazines, ammeline and
ammelide on cation-exchanger. This tandem procedure was successfully applied for
analysing and quantifying atrazine ozonation products and its efficiency
demonstrated using [U-ring 14C]-labelled atrazine experiments.
PMID- 10670810
TI - New operational modes for multidimensional and comprehensive gas chromatography
by using cryogenic modulation.
AB - Historically, hardware and method-related concerns have limited the use of
multidimensional gas chromatography in the routine laboratory. This paper
presents a new approach that offers the potential to significantly alter the
manner in which multidimensional gas chromatography is conducted, based on the
use of a modulated cryogenic trap which can be moved longitudinally along the
column. Two columns are directly coupled, and no switching valves are used. It is
demonstrated that a heartcut section can be cryofocused and zone-compressed, and
then rapidly remobilized at the prevailing column oven temperature without any
supplementary heating. A short second dimension column is used, giving fast
second dimension analysis. This allows a large number of heartcuts to be
programmed for any one analysis. The 'ultimate' manifestation of multidimensional
gas chromatography is the comprehensive GC technique (GC X GC). This is now
simply effected by performing very rapid heartcuts at intervals on the order of
1/5th of the peak width of primary dimension peaks, and requires that the second
dimension be able to complete the analysis of each collected zone on a similar
timeframe. This paper uses a semi-volatile aromatic mixture to demonstrate these
selected operational modes, that can be achieved with the longitudinal modulation
method. The flexibility that arises from this approach is shown by the ability to
swap between selected whole-peak enhancement and comprehensive modes during the
one analytical run. The increased sensitivity that follows from peak compression
is a further advantage, which would be beneficial for trace analysis.
PMID- 10670811
TI - Enantiomer separation of polychlorinated biphenyl atropisomers and
polychlorinated biphenyl retention behavior on modified cyclodextrin capillary
gas chromatography columns.
AB - Seven commercially-available chiral capillary gas chromatography columns
containing modified cyclodextrins were evaluated for their ability to separate
enantiomers of the 19 stable chiral polychlorinated biphenyl (PCB) atropisomers,
and for their ability to separate these enantiomers from achiral congeners,
necessary for trace environmental analysis of chiral PCBs. The enantiomers of
each of the 19 chiral PCBs were at least partially separated on one or more of
these columns. Enantiomeric ratios of eleven atropisomers could also be
quantified on six columns as they did not coelute with any other congener
containing the same number of chlorine atoms, so could be quantified using gas
chromatography-mass spectrometry. Analysis of a lake sediment heavily
contaminated with PCBs showed enantioselective occurrence of PCB 91, proof
positive of enantioselective in situ reductive dechlorination at the sampling
site.
PMID- 10670812
TI - Gas chromatographic quantification of amino acid enantiomers in food matrices by
their N(O,S)-ethoxycarbonyl heptafluorobutyl ester derivatives.
AB - Several amino acid enantiomer derivatives were prepared with different
chloroformates and analysed by gas chromatography (GC) on a Chirasil-L-Val GC
column, at a temperature below 200 degrees C. Among them the N(O,S)
ethoxycarbonyl heptafluorobutyl esters presented the best compromise between
short retention times, high yield responses and good resolution for almost all
the tested amino acids. These derivatives proved to be suited for quantification
of amino acids in aqueous media, with L-p-chlorophenylalanine as internal
standard. The developed procedure was applied to several food samples for
determination of their free amino acid profiles.
PMID- 10670813
TI - Selective extraction of hydrocarbons, phosphonates and phosphonic acids from
soils by successive supercritical fluid and pressurized liquid extractions.
AB - Hydrocarbons, dialkyl alkylphosphonates and alkyl alkylphosphonic acids are
selectively extracted from spiked soils by successive implementation of
supercritical carbon dioxide, supercritical methanol-modified carbon dioxide and
pressurized water. More than 95% of hydrocarbons are extracted during the first
step (pure supercritical carbon dioxide extraction) whereas no organophosphorus
compound is evidenced in this first extract. A quantitative extraction of
phosphonates is achieved during the second step (methanol-modified supercritical
carbon dioxide extraction). Polar phosphonic acids are extracted during a third
step (pressurized water extraction) and analyzed by gas chromatography under
methylated derivatives (diazomethane derivatization). Global recoveries for these
compounds are close to 80%, a loss of about 20% occurring during the
derivatization process (co-evaporation with solvent). The developed selective
extraction method was successfully applied to a soil sample during an
international collaborative exercise.
PMID- 10670814
TI - Study of dead volume measurement in packed subcritical fluid chromatography with
ODS columns and carbon dioxide-modifier mobile phases.
AB - Studies were done for providing a simple, rapid and reliable procedure of void
volume measurement in packed subcritical fluid chromatography (pSubFC), with CO2
modifier mobile phases containing high modifier amounts. Methods used in RPLC
with ODS columns were applied in pSubFC: gravimetric, homologous series
linearisation and unretained marker injection. Results lead us to propose the
method of marker injection to determine the void volume in pSubFC. Acetonitrile
was chosen as the void volume marker among six tested markers. Furthermore, void
volume variations vs. the modifier volume (from 5 to 45%) were studied for nine
organic modifiers. The void volume variations were related both to adsorption
desorption phenomena between the mobile phase and the stationary phase and to
mobile phase density changes. These variations allowed the classification of the
modifiers into four groups on the basis of the molecular interactions.
PMID- 10670815
TI - Micellar electrokinetic chromatography for the analysis of D-amygdalin and its
epimer in apricot kernel.
AB - We have developed a simple, rapid and reproducible method for the determination
of D-amygdalin and its epimer by using micellar electrokinetic chromatography
(MEKC). Separation of D-amygdalin was performed in a 20 mM sodium borate buffer
(pH 8.5) containing 300 mM sodium dodecyl sulfate using a bare fused-silica
capillary. The eluates were monitored by the absorbance at 210 nm. The applied
electric field was 278 V/cm, and the time needed for the separation of D
amygdalin did not exceed 6 min. The calibration curve for D-amygdalin showed
excellent linearity in the concentration range of 5-500 microg/ml. The migration
time and the corrected peak area show relative standard deviations (n=6) of 0.86%
and 1.48%, respectively. The limit of detection (S/N=3) for D-amygdalin was 2
microg/ml. Under acidic and neutral conditions, amygdalin exists only as the D
form; however, under basic conditions, it shows both the D- and L-forms with a
concentration ratio of 1:1.3 (D-amygdalin/L-amygdalin). Results of HPLC, UV-Vis
spectrophotometry, and mass spectrometry reconfirmed the identification of D
amygdalin and its epimer. The number of theoretical plates of D-amygdalin is
about 100,000 in MEKC, which is significantly higher than approximately 8,000 of
HPLC. This method has been successfully applied to the determination of amygdalin
epimers in various apricot kernel extracts and pharmaceutical products.
PMID- 10670816
TI - Comparative studies on the analysis of glycosylation heterogeneity of sialic acid
containing glycoproteins using capillary electrophoresis.
AB - Comparative studies concerning glycoform analysis of sialoglycoproteins by
capillary electrophoresis were performed using a few separation modes hitherto
reported. Glycoprotein samples examined in the present study were successfully
separated to their respective glycoforms using surface-modified capillaries
commercially available for capillary gas chromatography in the running buffer
near their isoelectric points. The analysis times were less than 50 min and
reproducibilities in migration times were excellent (less than 2.0% RSD for both
run-to-run and day-to-day analyses). We present a method for the glycoform
analysis of alpha1-acid glycoprotein in sera by simple pre-treatment as an
application. The present technique will become one of the general methods for the
evaluation of glycosylation heterogeneity of commercially available glycoprotein
drugs.
PMID- 10670817
TI - Analysis of coptisine, berberine and palmatine in adulterated Chinese medicine by
capillary electrophoresis-electrospray ion trap mass spectrometry.
AB - Chinese medicine preparations contaminated with coptisine, berberine and
palmatine were studied by capillary electrophoresis-electrospray ion trap mass
spectrometry. The dubious adulterants were identified by their retention times,
molecular ions and specific fragment ions produced from collision induced
dissociation. The results showed that, in comparison with CE-UV and capillary
electrophoresis-electrospray mass spectrometry (CE-ESI-MS), more reliable
identification could be achieved with CE-ESI-MS-MS using ion trap mass
spectrometry.
PMID- 10670818
TI - Chromatographic separation of 3,4-difluorophenylacetic acid and its positional
isomers using five different techniques.
AB - The separation of five positional isomers from 3,4-difluorophenylacetic acid was
investigated using normal- and reversed-phase high-performance liquid
chromatography, capillary zone electrophoresis, gas chromatography and
supercritical fluid chromatography. Operating parameters of each technique, such
as temperature, type of stationary phase, mobile phase pH, ionic strength,
organic modifiers and additives were varied in order to elucidate the separation
mechanisms. Based on the advantages and disadvantages of each methodology, a
simple and practical RPLC method was selected. The method was validated in terms
of linearity, limit of detection, accuracy, recovery, ruggedness and precision.
PMID- 10670819
TI - Capillary electrophoretic determination of sanguinarine and chelerythrine in
plant extracts and pharmaceutical preparations.
AB - Capillary electrophoresis was employed to determine the principal quaternary
benzo[c]phenanthridine alkaloids, sanguinarine and chelerythrine, in two plant
extracts and one oral hygiene product. Phosphate-Tris buffer of pH 2.5 was used
as a background electrolyte, limits of detection were 3 micromol/l(-1)
(sanguinarine) and 2.4 micromol,l(-1) (chelerythrine) using UV detection at 270
nm. The method, which correlated well with HPLC, is suitable for serial
determination of sanguinarine and chelerythrine in plant products and
pharmaceuticals.
PMID- 10670820
TI - In vitro action of a combination of selected antimicrobial agents and chondroitin
sulfate.
AB - Chondroitin sulfate (CS), a highly anionic polymer and the most predominant
sulfated glycosaminoglycan in connective tissues, was investigated regarding to
its interaction with cationic disinfectants, which are used as antiinfectives in
humans. Combinations of cetylpyridiniumchloride (CPC), chlorhexidine (CHex), and
polyhexamethylene biguanide (PHMB) with CS, respectively, were prepared and the
resulting microbicidal activity of the mixtures was tested in the quantitative
suspension test without organic matter. Polyvidone-iodine and Ringer's solution
were used as controls. Even precipitated, the resulting test combinations behave
differently against Staphylococcus aureus, Enterococcus faecium, Escherichia
coli, Pseudomonas aeruginosa, and Candida albicans. CPC/CS demonstrated only
microbicidal activity against Gram-positive bacteria, and CHex/CS was more active
against Gram-negative bacteria and C. albicans. PHMB/CS, especially in
combination with CS-A, only revealed an antimicrobial effect against P.
aeruginosa after 60 min action. The interaction of cationic disinfectants with CS
showed depending on the investigated microorganism a more or less controlled
sustained release manner of the microbicidal agent from the precipitated complex,
with the only exception of PHMB in combination with CS-C, which is completely
neutralized. Polyvidone-iodine and Ringer's solution were not affected by CS.
PMID- 10670821
TI - Potentiation of thioacetamide hepatotoxicity by phenobarbital pretreatment in
rats. Inducibility of FAD monooxygenase system and age effect.
AB - The ability of phenobarbital to induce the expression and activity of microsomal
drug monooxygenases in the liver presents one of the most important issues in the
field of chemical interactions and in the toxicity of xenobiotics. The model of
rat liver injury induced by a single dose of thioacetamide (500 mg/kg
intraperitoneally) was used to study the effect of phenobarbital (80 mg/kg/day
intraperitoneally) for 5 days prior to thioacetamide. Serum parameters of liver
injury such as aspartate aminotransferase activity, gamma-glutamyl transferase
activity and the total bilirubin levels, as well as the activities of hepatic FAD
and cytochrome P450 microsomal monooxygenases, were assayed in 2- and 12-month
old rats. Samples of blood and liver were obtained from controls (injected at 0 h
with 0.5 ml of 0.9% NaCl) and at 12, 24, 48, 72 and 96 h of thioacetamide
intoxication either to non-treated or phenobarbital pretreated rats. Potentiation
of thioacetamide hepatotoxicity by phenobarbital pretreatment was demonstrated at
morphological level, and by significant increases in the activities of serum
aspartate aminotransferase and gamma-glutamyl transferase, and in the levels of
total bilirubin. The extent of potentiation of thioacetamide-induced liver injury
by phenobarbital pretreatment was similar in both age groups. Microsomal FAD
monooxygenase activity, the enzyme responsible for thioacetamide
biotransformation, was significantly enhanced (twofold) by phenobarbital
pretreatment, and also underwent a further increase following thioacetamide,
preceding the peak of necrosis. Cytochrome P450 monooxygenases were induced by
phenobarbital pretreatment more than sixfold, and sharply decreased when
phenobarbital was withdrawn and thioacetamide administered, showing at 48 h
intoxication values close to basal. Phenobarbital pretreatment potentiated
thioacetamide necrogenicity, and this potentiation was parallel to the induction
of the microsomal FAD monooxygenase system, both by phenobarbital and by
thioacetamide itself. The extent of thioacetamide-induced liver injury was
significantly higher in 12-month-old rats, but the effect of phenobarbital
pretreatment was similar in both age groups.
PMID- 10670822
TI - Conjugation of 1-naphthol in primary cell cultures of rat ovarian cells.
AB - The present study concerns conjugation of 1-naphthol in primary cultures of rat
ovarian cells. Two phase II enzymes catalyzing conjugation, i.e. phenol
sulfotransferase (P-SULT) and phenol UDP-glucuronosyltransferase (P-UGT), were
measured using 1-naphthol as substrate. The rates of conjugation by the different
cell types of the rat ovary were the same at low concentrations and short
incubation times. However, after 20 h of incubation the rate of conjugation in
cells isolated from ovaries enriched in corpora lutea (CL) exceeded the rate in
cells isolated from ovaries enriched in preovulatory follicles. In addition, when
the granulosa cells were removed from the preovulatory follicles, the rate of
conjugation was 1.7-fold higher, i.e. in the theca/stroma cells. When the cells
were incubated with 1-[14C]naphthol and conjugates were subsequently separated by
thin-layer chromatography, naphthyl glucuronide was the only conjugate observed.
Pentachlorophenol (PCP), a commonly used inhibitor of P-SULT, inhibited 1
naphthol conjugation 50% in cell cultures, as well as in microsomal preparations.
alpha-Naphthoflavone (ANF) and ellipticine (ELP), both cytochrome P450 (CYP)
inhibitors, affected the conjugation of 1-naphthol in different ways; ANF did not
affect P-UGT activity in microsomal preparations, but inhibited 1-naphthol
conjugation in cell cultures by as much as 90%. On the other hand, ELP inhibited
the conjugation of 1-naphthol up to 99% in the cell cultures, but only 75% in
microsomal fractions. Testosterone (TST) and estradiol inhibited this activity
approximately equal 50% in both of these experimental systems. Clomiphene citrate
(CLF), a drug used to induce ovulation and demonstrating both estrogenic and
antiestrogenic effects, did not influence the conjugation of 1-naphthol
significantly in the cell cultures. The present findings demonstrate that P-UGT
is by far the major enzyme conjugating 1-naphthol in the rat ovary and that
commonly used inhibitors of P-SULT and CYPs also inhibit P-UGT activity, either
directly or via other mechanisms.
PMID- 10670823
TI - Induction by perfluorinated fatty acids with different carbon chain length of
peroxisomal beta-oxidation in the liver of rats.
AB - The potency of the induction of peroxisomal beta-oxidation was compared between
perfluorinated fatty acids (PFCAs) with different carbon chain lengths in the
liver of male and female rats. In male rats, perfluoroheptanoic acid (PFHA) has
little effect, although perfluorooctanoic acid (PFOA), perfluorononanoic acid
(PFNA) and perfluorodecanoic acid (PFDA) potentially induced the activity. By
contrast, PFHA and PFOA did not induce the activity of peroxisomal beta-oxidation
in the liver of female rats while PFNA and PFDA effectively induced the activity.
The induction of the activity by these PFCAs was in a dose-dependent manner, and
there is a highly significant correlation between the induction and hepatic
concentrations of PFCAs in the liver regardless of their carbon chain lengths.
These results strongly suggest that the difference in their chemical structure is
not the cause of the difference in the potency of the induction. Hepatic
concentrations of PFOA and PFNA was markedly higher in male compared with female
rats. Castration of male rats reduced the concentration of PFNA in the liver and
treatment with testosterone entirely restored the reduction. In contrast to the
results obtained from the in vivo experiments, the activity of peroxisomal beta
oxidation was induced by PFDA and PFOA to the same extent in cultured hepatocytes
prepared from both male and female rats. These results, taken together, indicate
that difference in accumulation between PFCAs in the liver was responsible for
the different potency of the induction of peroxisomal beta-oxidation between
PFCAs with different carbon chain lengths and between sexes.
PMID- 10670824
TI - Induction of rat hepatic drug metabolizing enzymes by dimethylcyclosiloxanes.
AB - Low molecular weight dimethylcyclosiloxanes (DMCS) are important precursors in
the synthesis of polydimethysiloxane polymers widely used in industry, and in
medical and personal care products. The objective of this study was to
characterize the ability of two DMCS, octamethylcyclosiloxane (D4) and
decamethylcyclopentasiloxane (D5) to induce drug metabolizing enzymes in rats.
Male and female Sprague-Dawley rats were administered 1, 5, 20, or 100 mg/kg D4
or D5 in corn oil daily by gavage for 4 days. Changes in the levels of activity
and/or immunoreactivity of CYP1A1/2, CYP2B1/2, CYP3A1/2 and NADPH cytochrome P450
reductase in liver microsomes were examined. Significant increases were observed
in the liver to body weight ratio in female rats administered either D4 or D5 at
doses > or = 20 mg/kg. Increases in the liver to body weight ratio were observed
in male rats treated with > or = 100 mg/kg D5 but not with D4. Relatively large
increases in CYP2B1/2 enzymatic activity and immunoreactive protein were observed
with increasing concentrations of both D4 and D5. Significant increases in 7
pentoxyresorufin O-depentylase (PROD) activity were also detected in male and
female rats given D4 at doses > or = 5 mg/kg. D5 increased PROD activity in male
rats at doses > or = 20 mg/kg and in female rats at doses > or = 5 mg/kg. 7
Ethoxyresorufin O-deethylase (EROD) activity was increased in both male and
female rats receiving > or = 20 mg/kg D4 or > or = 5 mg/kg D5; however, no
changes were detected in CYP1A1/2 immunoreactive protein in rats of either sex.
D4 and D5 caused significant increases in CYP3A1/2 immunoreactive protein in only
male rats treated with 100 mg/kg of either compound. However, significant
increases were detected in CYP3A1/2 immunoreactive protein in female rats at D4
doses > or = 20 mg/kg and D5 doses > or = 5 mg/kg. Induction of NADPH cytochrome
P-450 reductase immunoreactive protein was observed with D4 in female rats and in
both male and female rats with D5. Induction of CYP2B/1/2, CYP3A1/2 and NADPH
cytochrome P450 reductase was observed in rats treated with 50 mg/kg
phenobarbital by intraperitoneal injection. Maximal CYP2B induction detected with
D4 was approximately 50% of the increase observed with phenobarbital. In summary,
D4 and D5 induced CYP2B1/2 in adult rat liver in a manner similar to that
observed with phenobarbital; however, differences were observed between D4 and D5
in their ability to induce CYP3A1/2 and NADPH cytochrome P450 reductase. Female
rats were more sensitive to the inductive properties of low doses of both DMCS
than male rats whereas male rats were more responsive to phenobarbital induction.
PMID- 10670825
TI - Renal production of thromboxane and prostaglandins in a rat model of type 2
diabetes.
AB - In an investigation of the involvement of prostanoids in the pathogenesis of
nephropathy in type 2 diabetes, we repeatedly measured the urinary excretion of
prostanoids in both diabetic and healthy rats as the rats aged. Seven rats of the
Otsuka Long-Evans Tokushima Fatty strain were used as rats with a model of type 2
diabetes and seven rats of the Long-Evans Tokushima Otsuka strain were used as
rats without diabetes. Thromboxane (TX) B2 and 6-keto-prostaglandin (PG) F1alpha,
the amounts of which reflect renal production of TXA2 and PGI2, respectively, and
PGE2 in urine collected in metabolic cages were assayed when rats were 14, 30,
46, and 54 weeks old. Plasma glucose and urinary protein excretion also were
measured periodically. The mean plasma glucose concentration of the diabetic rats
was higher than that of the healthy rats throughout the study. At 30 weeks and
later, urinary protein excretion by the diabetic rats was greater than that of
the healthy rats, and it increased with age. Urinary excretion of TXB2 by the
diabetic rats was higher than that of the healthy rats at 14 weeks (52.4+/-23.5
vs. 27.0+/-2.6 ng/day; mean +/- SD, P = .015) and the difference continued to the
end of the experiment. Urinary excretion of 6-keto-PGF1alpha by the diabetic rats
was high at 14 weeks (52.3+/-12.8 vs. 26.9+/-4.6 ng/day; mean +/- SD, P<.001) but
decreased with age and was the same as that of the healthy rats at 54 weeks. The
urinary excretion of PGE2 by the two groups of rats was not significantly
different. These results suggest that altered renal production of TXA2 and PGI2
is involved in the pathogenesis of diabetic nephropathy in rats with type 2
diabetes.
PMID- 10670826
TI - (N-stearyl, norleucine17) VIP hybrid inhibits the growth of pancreatic cancer
cell lines.
AB - The effects vasoactive intestinal peptide (VIP) antagonists were investigated on
pancreatic cancer cell lines. (N-Stearyl, Norleucine17) VIP hybrid ((SN)VIPhyb)
inhibited 125I-VIP binding to human Capan-2 cells with an IC50 value of 0.01
microM whereas VIP hybrid had an IC50 value of 0.2 microM. By RT-PCR and Northern
blot, VPAC1 receptor mRNA was detected in CAPAN-2 cells. One microM (SN)VIPhyb
and 10 microM VIPhyb inhibited the ability of 30 nM VIP to elevate cyclic AMP and
increase c-fos mRNA. (SN)VIPhyb, 1 microM inhibited the clonal growth of CAPAN-2
cells in vitro. In vivo, (SN)VIPhyb (10 microg/day s.c.) inhibited CAPAN-2
xenograft growth in nude mice. These results indicate that (SN)VIPhyb is a
pancreatic cancer VPAC receptor antagonist.
PMID- 10670827
TI - Somatosensory evoked potential, neurological examination and magnetic resonance
imaging for assessment of cervical spinal cord decompression.
AB - The present study was designed to determine the relationship between neurological
testing, anatomical imaging, and electrophysiological monitoring for assessing
outcome of cervical spinal cord decompression. We prospectively studied 28
consecutive patients (age 39-76 yr) who were subjected to presurgical-(1-3 wk)
and postsurgical (3-4 mo) neurological examination and recording of the median
nerve somatosensory evoked potential (SEP). In 13 patients, magnetic resonance
imaging (MRI) was also performed. Changes in neurological function, SEP and MRI
were evaluated and graded as (1) improvement,(2) no change or (3) deterioration.
Neurological outcome (NO) was based on changes in motor grade strength, sensory,
reflexes and gait. The SEP outcome was based on changes in latency and
disappearance of SEP waveform components whereas MRI evaluation was based on
changes in spinal cord and canal diameters. Significance of association between
NO, SEP and MRI was determined by Pearson's Chi-Square statistic (P<.05). The SEP
improved in 71% (20/28) and deteriorated in 28% (8/28) of the subjects. An
association between SEP changes and NO was found in 82% (23/28) of the subjects
(P = .0038). Decompression increased the spinal canal diameter in 92% (12/13),
and the spinal cord diameter in 38% (5/13) of the subjects. An association
between NO, or SEP and MRI was not detected. Changes in median nerve SEP latency
appear to be predictive of the neurological status of patients subjected to
cervical spinal cord decompression. Postoperative increments in SEP latency or
disappearance of the SEP waves were indicative of poor outcome after surgical
decompression of the cervical spinal cord.
PMID- 10670828
TI - Differential effects of hemorrhage and LPS on tissue TNF-alpha, IL-1 and
associate neuro-hormonal and opioid alterations.
AB - LPS administration and hemorrhage are frequently used models for the in vivo
study of the stress response. Both challenges stimulate cytokine production as
well as activate opiate and neuro-endocrine pathways; which in turn modulate the
inflammatory process. Differences in the magnitude and tissue specificity of the
proinflammatory cytokine and neuro-hormonal responses to these stressors are not
well established. We contrasted the tissue specificity and magnitude of the
increase in circulating and tissue cytokine (TNF-alpha, IL-1alpha and IL-1beta)
content in response to either fixed-pressure hemorrhage (approximately 40 mm Hg)
followed by fluid resuscitation (HEM) or lipopolysaccharide (LPS; 100 microg/100
g BW) administration. LPS and HEM elevated circulating levels of TNF-alpha, while
neither stress altered circulating IL-1-alpha and IL-beta. LPS-induced increases
in TNF-alpha content were greater than those elicited by HEM in all tissues
studied except for the lung, where both stressors produced similar increases.
Tissue (lung, spleen and heart) content of IL-1alpha was increased by HEM but was
not affected by LPS. Tissue (lung, spleen, and heart) content of IL-1beta was
increased by LPS but was not affected by HEM. HEM produced greater increases than
LPS in epinephrine (16- vs. 4-fold) and norepinephrine (4-fold vs. 60%) levels
and similar elevations in beta-endorphin. LPS produced greater elevation in
corticosterone levels (2-fold) than HEM (50%). These results suggest differential
tissue cytokine modulation to HEM and LPS, both with respect to target tissue and
cytokine type. The hormonal milieu to HEM is characterized by marked
catecholaminergic and moderate glucocorticoid while that of LPS is characterized
by marked glucocorticoid with moderate catecholaminergic influence.
PMID- 10670829
TI - Chinese green tea lowers cholesterol level through an increase in fecal lipid
excretion.
AB - Lung Chen Tea, a Chinese green tea, has been found to lower serum and liver
cholesterol. In this study, its dose response and mechanisms of action on
cholesterol lowering in diet-induced hypercholesterolemic Sprague-Dawley rats
were investigated. The activities of three major lipid metabolizing enzymes, 3
hydroxy-3-methylglutaryl-coenzyme A (HMG-Co A) reductase, cholesterol 7alpha
hydroxylase and fatty acid synthase (FAS), as well as fecal excretion of bile
acids and cholesterol were examined. Lung Chen Tea administration for eight weeks
significantly lowered the serum cholesterol in the 2% and 4% groups. The
activities of the three enzymes were not affected by Lung Chen Tea, but the fecal
bile acids and cholesterol excretions were significantly increased. These results
demonstrated that Lung Chen Tea lowered plasma cholesterol by increasing fecal
bile acids and cholesterol excretion. Further investigation is required to
evaluate the exact mechanisms of action of Lung Chen Tea.
PMID- 10670830
TI - Augmented platelet calcium uptake in response to serotonin stimulation in
patients with major depression measured using Mn2+ influx and 45Ca2+ uptake.
AB - There is an augmented platelet intracellular calcium response to serotonin
stimulation in major depression. The role that calcium influx has in this process
is not known. The objective of this study was to determine platelet calcium
influx in response to serotonin by two methods, Mn2+ influx and 45Ca2+ uptake, in
order to observe if the uptake response to serotonin was augmented in major
depression by comparing the response to normal controls. The use of the two
methods of calcium influx showed that serotonin stimulates calcium uptake into
platelets. Furthermore, patients with major depression have significantly
augmented platelet calcium uptake in response to serotonin. The interesting
finding was that calcium uptake into platelets is biphasic, occurring immediately
and after five minutes. These results may support the two pool model for calcium
oscillations within cells whereby extracellular calcium is needed for
intracellular calcium release, and for replenishment of depleted stores once
intracellular calcium is released.
PMID- 10670831
TI - Antinociceptive effect of (S)-N-desmethyl trimebutine against a mechanical
stimulus in a rat model of peripheral neuropathy.
AB - Trimebutine (2-dimethylamino-2-phenylbutyl 3,4,5-trimethoxybenzoate, hydrogen
maleate) relieves abdominal pain in humans. In the present study, the
antinociceptive action of systemic (S)-N-desmethyl trimebutine, a stereoisomer of
N-monodesmethyl trimebutine, the main metabolite of trimebutine in humans, was
studied in a rat model of neuropathic pain produced by chronic constriction
injury to the sciatic nerve. Mechanical (vocalization threshold to hindpaw
pressure) stimulus was used. Experiments were performed two weeks after surgery
when the pain-related behaviour has fully developed. (S)-N-desmethyl trimebutine
(1, 3, 10 mg/kg s.c.) produced dose-dependent antinociceptive effects on the
nerve-injured and the contralateral hindpaw. The effect of the lowest dose (1
mg/kg s.c.) of (S)-N-desmethyl trimebutine on the nerve-injured paw was equal to
that seen after a ten time stronger dose on the contralateral paw. The effect of
(S)-N-desmethyl trimebutine (1 mg/kg) was not naloxone reversible. The results
suggest that systemic (S)-N-desmethyl trimebutine may be useful in the treatment
of some aspects of neuropathic pain.
PMID- 10670832
TI - Effects of ouabain and flecainide on CO(2)-induced slowly adapting pulmonary
stretch receptor inhibition in the rabbit.
AB - The inhibitory effect of CO2 on slowly adapting pulmonary stretch receptors
(SARs) was examined before and after administration of ouabain, a Na+-K+ ATPase
inhibitor, and flecainide, a Na+ channel blocker. The experiments were performed
in anesthetized, artificially ventilated rabbits after vagus nerve section. CO2
inhalation (maximal tracheal CO2 concentration ranging from 9.2 % to 10.4%) for
about 60 sec decreased the receptor activity during both inflation and deflation.
The magnitude of decreased SAR activity during deflation was greater than that
seen during inflation. Administration of ouabain (25 microg/kg) initially
stimulated SAR activities during inflation and deflation, and after 20 min, the
SAR response was still kept excitatory in both inflation and deflation phases.
Under these conditions, CO2 inhalation inhibited SAR activities during inflation
and deflation. Flecainide treatment (3 mg/kg) that abolished veratridine (30
microg/kg)-induced SAR excitation had no significant effect on the inhibitory
responses of SAR activity to CO2. These results suggest that the inhibitory
effect of CO2 occurs when ouabain results in intracellular Na+ concentration
([Na+]i) increases in the SAR endings, and that CO2-induced SAR inhibition may
not be related to the reduction of influx of Na+ through voltage-gated Na+
channels.
PMID- 10670833
TI - Acute orexin effects on insulin secretion in the rat: in vivo and in vitro
studies.
AB - Orexin-A and orexin-B are members of a family of newly described orexigenic
hypothalamic neuropeptides. Scanty data are available suggesting the involvement
of orexins in regulation of the secretion of pituitary hormones and in control of
energy homeostasis. Present studies aimed to explain whether orexins affect blood
insulin concentration and insulin secretion in the rat. To check this
possibility, adult female rats were subcutaneously injected with different doses
(1 or 2 nmol) of orexin-A or orexin-B. A bolus administration of orexin-A
resulted in an increase in blood insulin (up to min 120) and glucose (60 min
after injection) concentration. The higher dose of orexin-B, on the other hand,
exerted effect on insulin secretion only at min 60 of experiment and neither
doses changed blood glucose level. Only orexin-A stimulated insulin secretion in
an in vitro perfusion system of the rat pancreas preparation, while orexin-B was
less effective. The results demonstrate that orexins belong to a group of
neuropeptides influencing insulin secretion and acting directly on the pancreas.
Direct, at least partial, effect of orexin on insulin secretion may be connected
with the regulation of metabolism by this peptide.
PMID- 10670834
TI - Oxidized LDL from subjects with different dietary habits modifies atherogenic
processes in endothelial and smooth muscle cells.
AB - Low-density lipoprotein (LDL) activates a number of processes involved in
atherogenesis and vasoconstriction. Evidence suggests that oxidation increases
the atherogenicity of LDL. We investigated the effects of oxidized LDL (ox-LDL)
on cytotoxicity, prostacyclin (PGI2), and cyclic guanosine-3',5'-monophosphate
(cGMP) production in rat vascular smooth muscle cell (VSMC) and rat heart
endothelial cell (EC) culture, as well as EC- and VSMC-mediated LDL oxidation.
Native LDL (n-LDL) was isolated from subjects on three long-term diets with
differing fatty acid content (control diet rich in saturated fat and vegetarian
and fish diets). The Cu2+-catalyzed oxidation of n-LDL was monitored using
conjugated diene formation and stopped at various time points to achieve 20%,
45%, 70%, and 100% levels of ox-LDL. The lag phase of oxidation by Cu2+ was
shortest and thiobarbituric acid-reactive substance (TBARS) formation by VSMC
mediated oxidation was highest with n-LDL obtained from the fish diet group.
There were no differences between the ox-LDLs obtained from the different diet
groups in their cytotoxicity in EC culture. The degree of oxidation did not
influence LDL cytotoxicity. In VSMC culture PGI2 production was increased by ox
LDLs from all diet groups. In EC culture only the extensively oxidized LDLs
obtained from the vegetarian diet group were able to induce PGI2 production. The
LDLs did not affect basal cGMP production in either EC or VSMC culture.
PMID- 10670835
TI - Thromboxane A2 receptor-mediated tonic contraction is attributed to an activation
of phosphatidylcholine-specific phospholipase C in rabbit aortic smooth muscles.
AB - Thromboxane A2 (TXA2) analogue STA2 produced a tonic contraction in rabbit aortic
smooth muscles. In the present study, we examined phosphatidylcholine (PC)
hydrolysis as a signaling pathway for the tonic contraction in rabbit aortic
smooth muscles. In the primary cultured cells labeled with [3H]choline, STA2
caused an accumulation of [3H]phosphorylcholine, a metabolite of PC by PC
specific PLC, in a concentration-dependent manner. The accumulation of
[3H]phosphorylcholine was inhibited by SQ29548, a TXA2 receptor antagonist. In
the muscle strips, STA2-induced tonic contraction was potently inhibited by D609,
an inhibitor of PC-specific phospholipase C in a concentration-dependent manner
with the IC50 of about 10 microM. Norepinephrine-induced tonic contraction was
also inhibited by D609 with a weaker potency. These results strongly suggest that
stimulation of TXA2 receptor results in the activation of PC-specific
phospholipase C to yield diacylglycerol that contributes to the tonic
contraction.
PMID- 10670836
TI - Grepafloxacin inhibits tumor necrosis factor-alpha-induced interleukin-8
expression in human airway epithelial cells.
AB - We examined the effect of grepafloxacin (GPFX), a new fluoroquinolone
antimicrobial agent, on interleukin-8 (IL-8) expression in tumor necrosis factor
alpha (TNF-alpha)-stimulated human airway epithelial cells (AEC). GPFX inhibited
IL-8 protein production as well as mRNA expression in a concentration-dependent
manner (2.5 - 25 micro g/ml), but the inhibition of IL-8 expression by
corresponding concentrations of GPFX to serum and airway lining fluids was not
complete. We discuss the modulatory effect of GPFX on IL-8 production in the
context of its efficacy on controlling chronic airway inflammatory diseases.
PMID- 10670837
TI - NF-kappaB regulatory mechanisms in alveolar macrophages from patients with acute
respiratory distress syndrome.
AB - Activation of the nuclear regulatory factor NF-kappaB occurs in the lungs of
patients with the acute respiratory distress syndrome (ARDS) and may contribute
to the increased expression of immunoregulatory cytokines and other
proinflammatory mediators in this setting. Because of the important role that NF
kappaB activation appears to play in the development of acute lung injury, we
examined cytoplasmic and nuclear NF-kapppaB counterregulatory mechanisms,
involving IkappaB proteins, in alveolar macrophages obtained from 7 control
patients without lung injury and 11 patients with established ARDS. Cytoplasmic
levels of the NF-kappaB subunits p50, p65, and c-Rel were significantly decreased
in alveolar macrophages from patients with ARDS, consistent with enhanced
migration of liberated NF-kappaB dimers from the cytoplasm to the nucleus.
Cytoplasmic and nuclear levels of IkappaBalpha were not significantly altered in
alveolar macrophages from patients with established ARDS, compared with controls.
In contrast, nuclear levels of Bcl-3 were significantly decreased in patients
with ARDS compared with controls (P = 0.02). No IkappaBgamma, IkappaBbeta, or
p105 proteins were detected in the cytoplasm of alveolar macrophages from control
patients or patients with ARDS. The presence of activated NF-kappaB in alveolar
macrophages from patients with established ARDS implies the presence of an
ongoing stimulus for NF-kappaB activation. In this setting, appropriate
counterregulatory mechanisms to normalize nuclear levels of NF-kappaB and to
suppress NF-kappaB-mediated transcription, such as increased cytoplasmic and
nuclear IkappaBalpha levels or decreased Bcl-3 levels, appeared to be induced.
Nevertheless, even though counterregulatory mechanisms to NF-kappaB activation
are activated in lung macrophages of patients with ARDS, NF-kappaB remains
activated. These results suggest that fundamental abnormalities in
transcriptional mechanisms involving NF-kappaB and important in the inflammatory
response occur in the lungs of patients with ARDS.
PMID- 10670838
TI - Altered calcium regulation and function of human neutrophils during multiple
trauma.
AB - Altered intracellular Ca2+ concentration is a pivotal regulatory mechanism of
leukocyte function. Since polymorphonuclear neutrophils (PMN) are involved in
traumatic organ dysfunction, we prospectively investigated Ca2+ regulation and
function of circulating PMN multiple trauma patients (Group A: ISS < 27; Group B:
ISS > or = 27). Circulating PMN were isolated during 12 days, followed by
determination of formyl-methionyl-leucyl-phenylalanine (fMLP)-induced PMN
superoxide production (PMN-SOP) by SOD-inhibitable ferricytochrome C reduction,
and PMN cytosolic Ca2+ concentration ([Ca2+]i) by fluorescent fura2/AM (340/380
ratio). PMN-SOP was significantly higher in Group B (mean ISS: 39.9 +/- 2; n =
21) at day of admission than in controls and Group A (mean ISS: 18.2 +/- 1; n =
22) (P< 0.05). In Group B, the significant rise of basal [Ca2+]i between Day 2
and Day 4 was associated with significant lower PMN-SOP during that period (P <
0.05). The fMLP-induced [Ca2+]i response was supranormal in both groups. PMN
elastase concentrations were substantially higher in Group B compared with Group
A until Day 4. Circulating IL-6, IL-8, and soluble TNF-receptor (55 kD) were
significantly increased in Group B compared with Group A at the day of trauma (P
< 0.05). Severe trauma is characterized by a biphasic pattern of neutrophil
priming characterized by early increase and secondary suppression. The
association of depressed neutrophil superoxide production (deactivation) and
elevated basal [Ca2+]i suggests Ca2+-mediated disturbance of neutrophil NADPH
oxidase metabolism.
PMID- 10670839
TI - Peritonitis in the baboon: a primate model which stimulates human sepsis.
AB - The physiological, hemostatic, and immunological responses of 12 chronically
instrumented conscious baboons with sepsis due to Escherichia coli peritonitis
were compared with that of similarly instrumented controls. Chronic indwelling
cannulae were placed in the aorta and pulmonary artery to monitor pressure,
cardiac output, and obtain blood samples. At t = 0 a sterile or E. coli-laden
fibrin clot containing 1.9-6.7 x 10(11) CFU/kg was introduced into the peritoneal
cavity. The control animals were group 1 (n = 3). The animals with peritonitis
were divided into three groups depending on their clinical response. Group 2
animals (n = 3) were clinically well at the time of sacrifice (day 14), group 3
(n = 4) survived but were obviously sick on day 14, and group 4 (n = 5) died of
sepsis. Implantation of a sterile fibrin clot was well tolerated with little
hemodynamic change and a transient minimal inflammatory response in group 1.
Implantation of an E. coli-containing clot elicited a hyperdynamic cardiovascular
response and evoked a marked inflammatory reaction and a disseminated
intravascular coagulopathy. Five of 12 (42%) E. coli animals died from sepsis. In
general, the physiological, hemostatic, and immunological disturbances tended to
be greatest in these animals. Autopsy revealed residual peritoneal inflammation
and varying degrees of inflammation in the lungs, adrenal, spleen, liver, and
kidneys in all the animals that received E. coli with the inflammatory infiltrate
increasing in severity from group 2 through group 4. Tissue necrosis was observed
only in the latter group. We conclude that the cardiovascular, hemostatic, and
immunological responses of baboons with sepsis due to E. coli peritonitis exhibit
a variable course that resembles the clinical manifestations of gram-negative
sepsis in humans.
PMID- 10670840
TI - Comparison of the mortality and inflammatory response of two models of sepsis:
lipopolysaccharide vs. cecal ligation and puncture.
AB - Sepsis remains a serious clinical problem despite intense efforts to improve
survival. Experimental animal models of sepsis have responded dramatically to
immunotherapy blocking the activity of cytokines. Despite these preclinical
successes, human clinical trials have not demonstrated any improvement in
survival. We directly compared the mortality, morbidity, and immunopathology in
two models of sepsis, one due to lipopolysaccharide (LPS) and the other to cecal
ligation and puncture (CLP). BALB/c mice were injected intraperitoneally with 250
microg of LPS or subjected to CLP with an 18-gauge needle. Both models yielded
similar mortality (> 85%) and morbidity. Additionally, neutropenia and
lymphopenia developed in both groups. Plasma and peritoneal levels of cytokines
(TNF, IL-1, IL-6, and the chemokines KC and MIP-2) were measured at 1.5, 4, and 8
h after challenge. LPS induced substantially higher levels of cytokines in both
compartments with peak levels between 1.5 and 4 h that began to decline at 8 h.
In contrast, cytokine levels in the CLP model were continuing to increase at the
8 h-time point and often exceeded the LPS-induced values at this time. Our data
demonstrate that the LPS and CLP models have similar mortality but significant
differences in the kinetics and magnitude of cytokine production. Immunotherapy
for sepsis based on cytokine production after LPS challenge is misdirected
because the LPS model does not accurately reproduce the cytokine profile of
sepsis.
PMID- 10670841
TI - Pulmonary endothelial and epithelial integrity and neutrophil infiltration after
endotoxin in interleukin-1 receptor knockout mice.
AB - Previously we found the structural integrity of the aortic endothelium was
maintained after the administration of endotoxin in type 1 interleukin-1 (IL-1)
receptor knockout mice. In this study, we investigated further the integrity of
pulmonary vascular endothelium, airway epithelial, pulmonary microvasculature,
and neutrophil infiltration into the microvasculature and respiratory air spaces.
Adult male C57BL/129J wild-type mice and C57BL/129J knockout mice possessing a
homozygous deletion of the type 1 IL-1 receptor received the following
intraperitoneal injections; 1) Escherichia coli endotoxin (ENDT) (10 mg/kg), 2)
ENDT (2 mg/kg given for 4 days), or (3) saline vehicle. Wild-type and knockout
control animals receiving saline vehicle showed normal endothelial and epithelial
ultrastructure with intact membranes. Pulmonary endothelial cell damage was found
only in wild-type mice given a single 10 mg/kg endotoxin dose. Airway epithelial
damage was found only in wild-type mice given a repetitive dose of endotoxin (2
mg/kg for 4 days). Neutrophil infiltration increased only in mice given a single
dose of endotoxin (10 mg/kg) with the wild-type increasing by 32% and the
knockouts by 6% compared with the saline control for that group respectively.
Serum IL-6 and nitric oxide (indicators of septic shock severity and lethality)
significantly increased only in the mice given 10 mg/kg of endotoxin. The
maintenance of pulmonary endothelial and epithelial cell integrity and the
decrease of neutrophil infiltration in the IL-1 knockout mice suggest that IL-1
contributes significantly to the severity of endotoxin-induced sepsis.
PMID- 10670842
TI - Effects of nicaraven on nitric oxide-related pathways and in shock and
inflammation.
AB - Expression of the inducible isoform of nitric oxide (NO) synthase, and the
formation of peroxynitrite from NO and superoxide are responsible for some of the
pathophysiological alterations seen during reperfusion injury and in various
inflammatory conditions. Some of the effects of peroxynitrite are related to DNA
single-strand breakage, and activation of poly (ADP-ribose) synthetase. Here we
investigated the effect of nicaraven (2(R,S)-1,2-bis(nicotinamido)propane), a
known hydroxyl radical scavenger compound and neuroprotective agent, on several
NO- and peroxynitrite related pathways in vitro, and in shock and inflammation in
vivo. Nicaraven, at 10 microM-10 mM, failed to inhibit the peroxynitrite-induced
oxidation of dihydrorhodamine 123, indicating that the agent does not act as a
scavenger of peroxynitrite. In RAW murine macrophages stimulated with
peroxynitrite, nicaraven caused a dose-dependent, slight inhibition of poly (ADP
ribose) synthetase activation, possibly due to a direct inhibitory effect on the
catalytic activity of poly (ADP-ribose) synthetase. Nicaraven partially protected
against the peroxynitrite-induced suppression of mitochondrial respiration in RAW
macrophages and caused a slight, dose-dependent inhibition of nitrite production
in RAW macrophages stimulated with bacterial lipopolysaccharide. We next
investigated the effect of nicaraven treatment in a variety of models of
inflammation and reperfusion injury. Nicaraven (at 10-100 microg/paw) exerted
significant protective effects in the carrageenan-induced paw edema model and (at
100 mg/kg i.v.) reduced neutrophil infiltration and histological damage in
splanchnic artery occlusion-reperfusion injury. However, nicaraven failed to
alter the course of hemorrhagic and endotoxic shock and arthritis in rodent
models. The current data indicate the limited role of hydroxyl radicals in the
pathogenesis of the inflammatory conditions tested.
PMID- 10670843
TI - Nitric oxide synthase inhibitor ameliorates oral total parenteral nutrition
induced barrier dysfunction.
AB - The expression of inducible nitric oxide synthase (iNOS) is increased in the
intestine and results in mucosal damage after endotoxin challenge. Although the
oral administration of total parenteral nutrition (TPN) solution promotes
bacterial translocation (BT) and increases the intestinal permeability, the role
of NO in the nutrition-induced loss of mucosal barrier function remains unclear.
The distribution of fluorescein isothiocyanate-dextran (FITC-dextran, 4400)
across the lumen of small intestine in rat was examined to investigate the role
of NOS activity on the intestinal permeability under oral TPN feeding. Fifty-one
rats were randomly divided into 4 groups. Group I (control group) was fed with
rat chow, group II received TPN solution orally. Groups III and IV received TPN
solution supplemented with NOS inhibitors. On day 9, FITC-dextran was injected
into the intestinal lumen. After 30 min, blood samples were taken from portal
vein and analyzed for plasma FITC-dextran level by fluorescence
spectrophotometry. Samples of small intestine were frozen and sectioned in a
cryostat for morphological and NOS histochemical studies. Homogenates of small
intestine were used for NOS activity measurement. The plasma level of FITC
dextran showed a significant increase (P < 0.05) in rats fed with oral TPN
compared with the control ones. Supplement with NOS inhibitors significantly
decreased the intestinal permeability in groups III and IV compared with group
II. Similarly, the total NOS activities showed a significant 2-fold increase (P<
0.05) in group II, and NOS inhibitors decreased the elevated NOS activity. These
data suggest that oral TPN feeding for 9 days leads to an increase in
permeability to dextran and the total NOS activity of small intestine, and both
induction of the intestinal permeability and NOS activity were inhibited by
treatment with NOS inhibitors. Addition of S-methylisothiourea (SMT), an iNOS
selective inhibitor, profoundly inhibited 66% of the induced iNOS activity (P <
0.05) and reduced 74% of the diet-induced increase in intestinal permeability (P
< 0.05) in group II. The induced permeability change in rats receiving oral TPN
is mainly due to the activity of intestinal mucosal iNOS. The induction of iNOS
is an important mediator for intestinal barrier dysfunction. Administration of
SMT, which specifically decreases iNOS activity, is useful in the prevention of
diet-induced barrier failure.
PMID- 10670844
TI - Kinetics of P-selectin expression in regional vascular beds after resuscitation
of hemorrhagic shock: a clue to the mechanism of multiple system organ failure.
AB - Leukocyte-endothelial cell interactions play an important role in mediating organ
dysfunctions observed after hemorrhagic shock. P-selectin is the first
endothelial cell adhesion molecule to be upregulated after an ischemic insult.
The objective of this study was to define kinetics of P-selectin expression in
different regional vascular beds of mice exposed to hemorrhagic shock. In-vivo P
selectin expressions were determined using dual radiolabeled monoclonal antibody
technique in lungs, heart, liver, kidneys, intestinal mesentery, stomach, small
bowel, and colon 0.5, 1, 2, 5, 10, and 24 h after resuscitation of 40 mmHg
hemorrhagic shock. In another group, P-selectin expression was determined in same
organs 5 h after resuscitation of 30 mmHg hemorrhagic shock. Hemorrhagic shock of
40 mmHg caused significant upregulation of P-selectin in lungs and liver at 30
min after resuscitation (P < 0.001). There was a second and more pronounced
upregulation of P-selectin in lungs and liver at 5 h after resuscitation (P <
0.001). In heart, intestinal mesentery, stomach, small bowel, and colon, P
selectin was not upregulated until 5 h after resuscitation from 40 mmHg
hemorrhagic shock (P < 0.001). While hemorrhagic shock of 40 mmHg did not cause P
selectin upregulation in kidneys, hemorrhage to 30 mmHg did elicit a significant
increase at 5 h after resuscitation (P < 0.001). We conclude that P-selectin is
upregulated after resuscitation of hemorrhagic shock in lungs, liver, heart,
stomach, and intestines. P-selectin upregulation in kidneys only takes place
after more severe hemorrhagic shock.
PMID- 10670845
TI - A role for nitric oxide in endotoxin-induced depletion of the peripheral
catecholamine stores.
AB - Endotoxemia is associated with increased sympathetic nerve activity and depletion
of norepinephrine (NE) and epinephrine (EPI) contents in the adrenal gland and in
sympathetically innervated tissues. Endotoxin (bacterial lipopolysacchride [LPS])
causes an increased production of nitric oxide (NO) by inducing nitric oxide
synthase (iNOS) expression in various tissues. This increased production of NO
contributes significantly to the hypotension associated with endotoxemia. At high
concentrations, NO also can act as a neurotoxin. In this study we tested the
hypothesis that increased production of NO is involved in depletion of
catecholamine content in various tissues from rats treated with a nonlethal dose
of LPS. Catecholamine content was measured by high-performance liquid
chromatography with electrochemical detection (HPLC-EC) and NOS activity was
measured by the 3H-I-arginine to 3H-I-citrulline conversion method. The NE
content was decreased in rat adrenal gland, lung, spleen, tail artery, and aorta
after LPS. The maximal decrease was at 24 h and returned to control levels at 6
days (144 h). There was no depletion of the NE content in the heart. The EPI
content in the adrenal gland was greatly depleted (91%) from 12 to 72 h after
LPS. LPS increased the NOS activity in all tissues examined. The time course for
NOS activity showed an increase at 3 h, a further increase at 6 h, and a return
to control level at 48 h after LPS. The increase in NOS activity occurred before
maximal catecholamine depletion. Aminoguanidine, a relatively selective iNOS
inhibitor, completely prevented NE depletion in all tissues and partially
prevented adrenal EPI depletion induced by LPS. These results are consistent with
the hypothesis that LPS-induced production of NO plays a role in depletion of
tissue NE and EPI.
PMID- 10670846
TI - Bovine hemoglobin-based oxygen carrier (HBOC-201) for resuscitation of
uncontrolled, exsanguinating liver injury in swine. Carolina Resuscitation
Research Group.
AB - In the setting of rapidly exsanguinating hemorrhage, resuscitation with
intravenous (i.v.) crystalloid solution may not sustain survival before
availability of allogenic blood transfusion and surgery. This study tested the
hypothesis that bovine hemoglobin-based oxygen carrier, HBOC-201, would improve
resuscitation and extend early survival from exsanguinating hemorrhage. This
study simulated the prehospital scenario of rapidly exsanguinating hemorrhage
with prolonged prehospital time and lack of blood availability. Severe
hemorrhagic shock was induced in swine by using multiple liver lacerations. At 9
min after the onset of bleeding, swine were randomized to receive approximately
10 mL/kg/min of i.v. lactated Ringer's solution (n = 10) or HBOC-201 (n = 7) to
achieve a mean aortic pressure (MAP) of 60 mmHg. Thereafter, infusion rate was
adjusted to maintain MAP at 60 mmHg for up to 2 h. All animals were initially
successfully resuscitated. The results showed 2-h survival was 1 of 10 with
lactated Ringer's and 7 of 7 with HBOC-201 (P = 0.0004). Nine lactated Ringer's
swine had cardiovascular collapse at 36 +/- 10 min. Lactate at 30 min was 18 +/-
3 mmol/L with lactated Ringer's and 12 +/- 2 mmol/L with HBOC-201 (P < 0.05).
Hematocrit was <1% in 9 of 10 lactated Ringer's and 6 of 7 HBOC-201 animals.
These data indicate that HBOC-201 improved early survival and stabilized
hemodynamic and metabolic parameters vs. lactated Ringer's in this swine model of
liver injury with uncontrolled, lethal hemorrhage that simulates the prehospital
care environment where allogenic blood is unavailable.
PMID- 10670847
TI - Suppression of lethal toxicity of endotoxin by biscoclaurine alkaloid
cepharanthin.
AB - Suppressive effects of Cepharanthin (CE) on lipopolysaccharide (LPS)-induced
tumor necrosis factor alpha (TNFalpha) production followed by liver injury were
investigated. Pretreatment with CE reduced limulus activity of LPS.
Intraperitoneal treatment with CE 10 min before an i.v. challenge of LPS resulted
in protection from LPS lethality in D-galactosamine (GalN)-sensitized BALB/c but
not in C57BL/6 and C57BL/10ScSn mice. Treatment with CE before the LPS challenge
significantly reduced serum TNF levels in a dose-dependent manner. The
suppression was most effective when CE was administered 10 min before the LPS
challenge. Increased levels of enzymes released from hepatocytes into the
circulation, as a result of LPS-induced liver injury, were reduced by CE
administration. Histological evaluation demonstrated that massive cell
infiltration after severe injury developed in liver of mice injected with LPS
plus D-GalN unless they were pretreated with CE. Apoptotic cells decreased by
treatment with CE. Treatment with CE retarded lethal shock induced by an
infection with 10(8) CFU Salmonella typhimurium deltaaroA mutant. These results
suggest that action of CE is initiated through suppression of LPS-induced TNF
production.
PMID- 10670848
TI - Strategic planning for survival of surgical societies in the new millennium.
PMID- 10670849
TI - Surgical progress and understanding in the treatment of the melanoma epidemic.
PMID- 10670850
TI - The role of the gastrointestinal tract in postinjury multiple organ failure.
AB - Despite intensive investigation, the pathogenesis of postinjury multiple organ
failure (MOF) remains elusive. Laboratory and clinical research strongly
implicate that the gastrointestinal tract plays a pivotal role. Shock with
resulting gut hypoperfusion appears to be one important inciting event. While
early studies persuasively focused attention on bacterial translocation as a
unifying mechanism to explain early and late sepsis syndromes that characterize
postinjury MOF, subsequent studies suggest that other gut-specific mechanisms are
operational. Based on our Trauma Research Center observations and those of
others, we conclude that: 1) bacterial translocation may contribute to early
refractory shock; 2) for patients who survive shock, the reperfused gut appears
to be a source of proinflammatory mediators that may amplify the early systemic
inflammatory response syndrome; and 3) early gut hypoperfusion sets the stage for
progressive gut dysfunction such that the gut becomes a reservoir for pathogens
and toxins that contribute to late MOF.
PMID- 10670851
TI - Radiation safety with breast sentinel node biopsy.
AB - BACKGROUND: Sentinel lymph node biopsy with Technetium 99m sulfur colloid (Tc99m)
is an evolving technique that offers the potential for improved staging of breast
cancer with decreased morbidity. However, the use of radioactive materials in the
operating room generates significant concern about radiation exposure. The
purpose of this study was to evaluate radiation exposure to operating room
personnel, pathologist, and equipment from specimens during breast sentinel lymph
node biopsy. METHODS: Twenty patients were injected with 0.7 to 1.1 mCi of Tc99m
sulfur colloid 1.5 to 3 hours before sentinel lymph node biopsy. A calibrated
Geiger counter was used to measure dose rates from the breast injection site
before skin incision (n = 20), lumpectomy specimens (n = 8), and sentinel nodes
(n = 20) at distances of 3, 30, and 300 cm. This represented exposure to the
surgeon's hands, surgeon's torso, and scrub nurse, respectively. Exposure to the
pathologist's hands and torso was represented as dose-rate measurements from
lumpectomy and nodal specimens. The operative instruments, trash receptacles,
suction canisters, pathology slides, and cryostat machines were measured at 3 cm
at the conclusion of each procedure. Specimens or equipment emitting radiation
doses equal to background levels (0.04 mRem/h) were exempt from special handling
and disposal. RESULTS: The highest exposure rate was to the surgeon's hands from
the breast injection site before skin incision (34.25 mRem/h). Exposure to the
surgeon's torso measured 1.33 mRem/h, and exposure to the scrub nurse's torso
measured 0.15 mRem/h from the injection site. Exposure to the pathologist's hands
was 18.62 and 0.06 mRem/h from the lumpectomy specimen and sentinel node,
respectively. Exposure to the pathologist's torso measured 0.34 and 0.04 mRem/h
from the lumpectomy specimen and sentinel node, respectively. One hundred percent
of lumpectomy specimens measured above the exempt level. Thirty-two of 46 (70%)
sentinel lymph nodes emitted radiation equal to the exempt background level.
Seventeen of 20 trash receptacles (85%) and 4 of 12 (33%) suction canisters
measured equal to background levels. All operative instruments, pathology slides,
and cryostat machines were equal to background levels. CONCLUSIONS: Radiation
exposure to operating room personnel, pathologists, and operative equipment
during a breast sentinel node biopsy using Tc99m is minimal. A primary surgeon
can perform 2,190 hours, a scrub nurse 33,333 hours, and a pathologist 14,705
hours of procedural work before surpassing Occupational Safety and Health
Administration limits. Operative instruments, pathology slides, and cryostat
machines do not require special handling. All lumpectomy specimens should be
stored for decontamination until the dose rate equals background levels.
Intraoperative dose-rate monitoring allows selective decontamination of nodal
specimens, trash receptacles, and suction canisters, which decreases disposal
time and cost.
PMID- 10670852
TI - Is laparoscopic approach to lumbar spine fusion worthwhile?
AB - BACKGROUND: Laparoscopic lumbar spine fusion has been recently described. The aim
of this study is to evaluate the safety and efficacy of this procedure for single
and multiple-level degenerative disc disease. METHODS: Twenty-four consecutive
laparoscopic interbody lumbar fusions were evaluated prospectively (18 single
level were compared with 6 multiple-level procedures). Results of the
laparoscopic multiple-level procedures were further compared with 12 open
multiple-level operations. RESULTS: Twenty procedures were completed
laparoscopically. The conversions were related to iliac vein lacerations (3
cases) and a mesenteric tear. Single-level cases had lower morbidity (22% versus
83%), shorter hospital stay (2 versus 10 days), and higher fusion rate (88%
versus 50%) than multiple-level procedures. Overall results in the latter group
were worse than in the matched open group. CONCLUSIONS: Laparoscopic single-level
fusion (L5-S1) is safe and carries the benefits of minimal access surgery.
Morbidity after multiple level approach is high, and this procedure cannot be
advocated at this time.
PMID- 10670853
TI - Cholecystectomy is an effective treatment for biliary dyskinesia.
AB - BACKGROUND: An increasing number of reports indicate symptomatic relief of
biliary colic symptoms after cholecystectomy for biliary dyskinesia. Despite
this, cholecystectomy as a treatment for biliary dyskinesia remains
controversial. Our aim was to determine efficacy of cholecystectomy in
alleviating biliary dyskinesia symptoms and the correlation with histologic
findings. METHODS: Records of patients with gallbladder ejection fraction <35%
between January 1994 and February 1999 were reviewed. Gallbladder pathology and
degree of symptomatic improvement were determined on follow-up. RESULTS: Of the
27 cholecystectomy patients, 24 (89%) had significant improvement, 2 (7%) had
partial improvement, and 1 (4%) had minimal improvement. Ten patients (43%) had
normal gall-bladder, and 9 (90%) of them had significant improvement after
cholecystectomy. Of the 6 nonsurgical patients, none had significant improvement,
4 (67%) had partial improvement, and 2 (33%) had minimal improvement.
CONCLUSIONS: Biliary dyskinesia patients who underwent cholecystectomy had
significantly greater symptom improvement compared with nonsurgical patients.
Pathologic correlation suggests chronic inflammation may not be the only cause of
gallbladder dysfunction. Cholecystectomy should be a first-line therapy for
biliary dyskinesia patients.
PMID- 10670854
TI - Breast conservation therapy in affiliated county, university, and private
hospitals.
AB - BACKGROUND: Breast conservation therapy (BCT) offers equivalent survival to
modified radical mastectomy in patients with early-stage (I and IIa) breast
cancer, but is utilized in less than 50% of eligible patients. While patient
demographics have been linked to BCT rates, we suspected that physician influence
was a major factor. The purpose of this study was to compare BCT at three
affiliated centers staffed by similarly trained surgeons yet serving widely
disparate populations, in order to assess the importance of physician influence
on the utilization of BCT. METHODS: Tumor registry data were reviewed from 1993
through 1997 at affiliated city/county (CH), university (UH), and private
hospitals (PH). Data were analyzed for clinical stage, treatment, and age of
patient. RESULTS: The utilization of BCT for stage I and IIa breast cancer is
similar at the three hospitals: 45% of patients at CH, 55% of patient at UH, and
57% of patients at PH (P>0.05). Rates of BCT were similar across all patient age
groups at all sites. CONCLUSIONS: Similar BCT utilization rates can be achieved
despite widely disparate patient populations. The three affiliated hospitals are
staffed by surgeons with similar training, and all offer a multidisciplinary
approach to breast cancer care. This suggests that physician influence may
override patients' socioeconomic issues in providing optimal breast cancer
therapy.
PMID- 10670855
TI - Low use of breast conservation surgery in medically indigent populations.
AB - BACKGROUND: Breast conservation surgery (BCS) with radiation is an acceptable
treatment for early-stage breast cancer. METHODS: Data were obtained from
hospital cancer registries on women surgically treated for Stage 0 to II breast
cancer from 1993 to 1997. Data on 1,747 patients were analyzed for surgical
treatment, hospital type (private versus public), disease stage, and ethnic
origin. RESULTS: In this study, 34% of women received BCS. Women treated in
private hospitals received BCS more often than women treated in public hospitals.
Women with stage II disease received BCS less often than women with earlier stage
disease. Hospital type (public versus private) and disease stage were strong,
independent predictors for use of BCS. When hospital type and disease stage were
statistically controlled, no treatment differences across ethnic groups were
identified. CONCLUSIONS: Use of BCS in this study was low compared with National
Cancer Database statistics. Women treated in publicly funded hospitals and those
with stage II disease were significantly less likely to receive BCS.
PMID- 10670856
TI - Accuracy of surgeon-performed gallbladder ultrasound.
AB - BACKGROUND: Symptomatic cholelithiasis is among the most common of general
surgery referrals. With an appropriate clinical presentation, definitive
diagnosis requires documentation of gallstones by ultrasonography (US). The
authors evaluated the accuracy of surgeon-performed US for identifying gallstones
in patients with a nonacute indication for study. METHODS: Patients referred for
symptomatic cholelithiasis and who provided informed consent received an US
examination by one or more of the surgical investigators. Surgeon-performed US
findings were correlated with radiologist US findings and pathologic diagnoses.
RESULTS: Seventy-seven patients received a total of 128 examinations by the
investigators. Surgeon-performed US examination agreed with the radiologist US
findings for 112 of 122 studies (92%) with a sensitivity of 100% and a
specificity of 95%. Surgeon-performed US findings correlated with the pathologic
diagnoses for 83 of 86 studies (97%). CONCLUSIONS: Surgeons can perform
gallbladder US in the nonacute setting with a high degree of accuracy.
PMID- 10670857
TI - The efficacy of magnetic resonance cholangiography for the evaluation of patients
with suspected choledocholithiasis before laparoscopic cholecystectomy.
AB - BACKGROUND: Endoscopic retrograde cholangiography is the most commonly utilized
tool for the identification of common bile duct stones (CBDS) before laparoscopic
cholecystectomy, whereas the role of magnetic resonance cholangiography (MRC) for
patient evaluation before laparoscopic cholecystectomy is currently undefined.
METHODS: We prospectively evaluated the efficacy of MRC for the identification of
CBDS among patients with high risk for choledocholithiasis. Patient selection was
based on clinical, sonographic, and laboratory criteria. Standard cholangiograms
were obtained when possible for verification of MRC results. RESULTS: Ninety-nine
patients underwent evaluation with preoperative MRC. CBDS was visualized in 30%
of patients. MRC sensitivity, specificity, positive predictive value, negative
predictive value, and accuracy were 85%, 90%, 77%, 94%, and 89%, respectively.
CONCLUSIONS: MRC is useful for the evaluation of patients with suspected
choledocholithiasis. Advantages of MRC include its noninvasive nature, ease of
application, and accuracy in identifying and estimating the size of CBDS.
Application of MRC in this setting reduces the need for diagnostic endoscopic
retrograde cholangiography. Future investigations should be directed at the
development of cost-effective utilization strategies for MRC application.
PMID- 10670858
TI - The role of computed tomography in the diagnosis of acute appendicitis.
AB - BACKGROUND: Routine contrast-enhanced computed tomography (CECT) has been
described as an accurate diagnostic imaging modality in patients with acute
appendicitis. However, most patients with acute appendicitis can be diagnosed by
clinical findings and physical exam alone. The role of CECT in patients suspected
of having appendicitis but with equivocal clinical exams remains ill defined.
METHODS: One hundred and seven consecutive patients who were thought to have
appendicitis but with equivocal clinical findings and/or physical exams were
imaged by CECT over a 12-month period. Oral and intravenous contrast-enhanced,
spiral abdominal and pelvic images were obtained using 7-mm cuts. CECT images
were interpreted by a board-certified radiologist. Main outcome measures included
CECT sensitivity, specificity, positive predictive value (PPV), negative
predictive value (NPV), and accuracy in the diagnosis of acute appendicitis,
comparing CECT with ultrasound, and determining the impact of CECT on the
clinical management of this patient population. RESULTS: A group of 107 patients
consisting of 44 males (41%) and 63 females (59%) with a median age of 33 years
(range 13 to 89 years) were imaged with CECT to evaluate suspected appendicitis.
Of the 107 CECTs performed, 11 false-positive and 3 false-negative readings were
identified, resulting in a sensitivity of 92%, specificity of 85%, PPV of 75%,
NPV of 95%, and an overall accuracy of 90%. Forty-three patients were imaged with
ultrasound and CECT, and CECT had significantly better sensitivity and accuracy
(30% versus 92% and 69% versus 88%, P<0.01). With regard to clinical management,
100% (36/36) of patients with appendicitis, and 4.2% (3/71) of patients without
appendicitis underwent appendectomy. Therefore, the overall negative appendectomy
rate was 7.6% (3/39). CONCLUSIONS: CECT is a useful diagnostic imaging modality
for patients suspected of having acute appendicitis but with equivocal clinical
findings and/or physical exams. CECT is more sensitive and accurate than
ultrasound and is particularly useful in excluding the diagnosis of appendicitis
in those without disease.
PMID- 10670859
TI - Laparoscopic ultrasound imaging of adrenal tumors during laparoscopic
adrenalectomy.
AB - BACKGROUND: The purpose of this study was to determine the usefulness of
laparoscopic ultrasound (LUS) during laparoscopic adrenalectomy (LA) and to
define the ultrasound imaging characteristics of various adrenal tumors. METHODS:
LUS was utilized in 27 patients who underwent LA (including one bilateral
adrenalectomy) from May 1994 to October 1998. Tumor size ranged from 1.0 to 5.5
cm (mean 3.3 cm), and a transabdominal lateral approach to LA was used. RESULTS:
LUS localized the adrenal gland and tumor in all 28 adrenalectomies and
demonstrated the relationship of the tumor to the kidney and adjacent vascular
structures (renal artery/vein and inferior vena cava). The adrenal vein was
visualized sonographically in only six cases (21 %). Pheochromocytomas were mild
to markedly heterogenous, whereas most aldosteronomas and cortical adenomas were
homogenous. LUS provided useful information to the surgeon in 11 of 28 cases
(39%) by: 1) localizing the adrenal gland and tumor and/or guiding the
dissection; 2) demonstrating that tumors > or =4 cm were confined to the adrenal
gland; and 3) investigating suspected pathology in other organs. Mean operating
time for LUS was 10.9 min (range 5 to 24 min) and calculated hospital charges
were $602. CONCLUSIONS: LUS accurately localizes adrenal tumors, helps define
their relationship to adjacent structures, and provides confirmation that larger
tumors are amenable to laparoscopic resection. LUS is a useful adjunct to
laparoscopic adrenalectomy in selected patients.
PMID- 10670860
TI - Role of breast magnetic resonance imaging in determining breast as a source of
unknown metastatic lymphadenopathy.
AB - BACKGROUND: Occult primary breast cancer (OPBC) represents less than 1% of breast
cancer. In only a third of cases, mammography identifies a primary tumor. We
hypothesized that rotating delivery of excitation off-resonance breast magnetic
resonance imaging (MRI) would identify or exclude the breast as a primary site in
patients with OPBC. METHODS: In a retrospective review, 10 patients were
identified with OPBC in which MRI was performed. Malignant appearing lesions were
correlated with histopathologic findings at biopsy or surgery. RESULTS: MRI
identified the primary site in 8 of 10 cases as breast (80%), and excluded it in
2 cases. The extent of disease and location was accurately predicted when
compared with histopathologic specimen. CONCLUSIONS: As we continue to focus on a
cure of early breast cancer, it is imperative that diagnostic images become more
sensitive and specific. MRI accurately predicted OPBC in this subset of patients.
PMID- 10670861
TI - Complete myocardial revascularization on the beating heart.
AB - BACKGROUND: Complete myocardial revascularization with excellent visualization,
exposure, and stabilization can be accomplished on the beating heart without
cardiopulmonary bypass (CPB). METHODS: Three hundred patients were totally
revascularized via median sternotomy with myocardial stabilization using the
CardioThoracic System. All patients who underwent coronary artery bypass grafting
were considered for the off-pump procedure. Pericardial sutures were placed at
the level of the left atrial appendage and were pulled upwards to the right. The
stabilizer was applied sequentially from circumflex, obtuse marginal,
intermediate, diagonal, left anterior descending, and right coronary artery.
Coronaries were occluded using the Calafiore technique, and multiple arterial
grafts were inserted. RESULTS: The average number of grafts was 3.4 per patient.
Six percent had to be converted to standard CPB. Comorbidity was not a limiting
factor with 8% redos, 48% having diabetes, and acute myocardial infarctions in
28%. The unadjusted mortality was 2.3%, and stroke rate was 0.7%. CONCLUSIONS:
These results indicate that complete revascularization can safely be accomplished
without CPB.
PMID- 10670862
TI - Comparison of carotid endarterectomy using primary closure, patch closure, and
eversion techniques.
AB - BACKGROUND: This study was undertaken to evaluate the role of eversion
endarterectomy in the management of extracranial carotid occlusive disease.
METHODS: A retrospective review was performed of all patients undergoing carotid
endarterectomy between July 1994 and July 1998. After reviewing the records,
patients were assigned to one of three groups: eversion (ECEA); open with primary
closure (CEA); or open with patch closure (CEAP). Statistical comparisons were
made. RESULTS: The 190 index cases comprised 33 ECEA (17%), 15 CEA (8%), and 142
CEAP (75%). Both ECEA and CEA were more likely to be done on males versus females
compared with CEAP (P = 0.01). For the entire 190 cases, stroke occurred in 1
patient (0.5%); and myocardial infarction in 2 patients (1%), resulting in death
in both. Two patients (1.4%) in the CEAP group have undergone redo surgery at 8
and 24 months. CONCLUSIONS: This study demonstrates that eversion endarterectomy
achieves early results similar to open endarterectomy with and without patch
closure.
PMID- 10670863
TI - Surgical complications from hemostatic puncture closure devices.
AB - BACKGROUND: For securing immediate hemostasis following percutaneous arterial
catheterization, the Food and Drug Administration has approved three hemostatic
puncture closure devices. We reviewed our institutional experience with one
device (Angio-Seal). METHODS: A retrospective, single-center, nonrandomized
observational study was made of all vascular complications following femoral
cardiac catheterization. RESULTS: An immediate mechanical failure of the device
was experienced in 34 (8%) patients. Surgical repair was required in 1.6% (7 of
425) of patients following Angio-Seal versus 0.3% (5 of 1662) following routine
manual compression (P = 0.004). In 5 patients, the device caused either complete
occlusion or stenosis of the femoral artery. The polymer anchor embolized in 1
patient and was retrieved with a balloon catheter at surgery. CONCLUSION: During
the first year of utilization of a percutaneous hemostatic closure device
following cardiac catheterization, we observed a marked increase in arterial
occlusive complications requiring surgical repair. Surgeons must be familiar with
the design of these devices to achieve precise repair of surgical complications.
PMID- 10670864
TI - Optimizing screening for blunt cerebrovascular injuries.
AB - BACKGROUND: The recognition that early diagnosis and intervention, prior to
ischemic neurologic injury, has the potential to improve outcome following blunt
cerebrovascular injuries (BCVI), led to a policy of aggressive screening for
these injuries. The resultant epidemic of BCVI has created a dilemma, as
widespread screening is impractical. We sought to identify independent predictors
of BCVI, to focus resources. METHODS: Cerebral arteriography was performed based
on signs or symptoms of BCVI, or in asymptomatic patients with high-risk
mechanisms (hyperextension, hyperflexion, direct blow) or injury patterns.
Logistic regression analysis identified independent predictors. RESULTS: A total
of 249 patients underwent arteriography; 85 (34%) had injuries. Independent
predictors of carotid arterial injury were Glasgow coma score < or =6, petrous
bone fracture, diffuse axonal brain injury, and LeFort II or III fracture. Having
one of these factors in the setting of a high-risk mechanism was associated with
41% risk of injury. Of patients with cervical spine fracture, 39% had vertebral
arterial injury. CONCLUSIONS: Patients sustaining high-risk injury mechanisms or
patterns should be screened for BCVI. In the face of limited resources, screening
efforts should be focused on those with high-risk predictors.
PMID- 10670865
TI - The laparoscopic management of appendicitis and cholelithiasis during pregnancy.
AB - BACKGROUND: Laparoscopic management of appendicitis and symptomatic
cholelithiasis during pregnancy remains controversial. We report the single
largest series of laparoscopic cholecystectomies and appendectomies during
pregnancy. METHODS: Medical records of all pregnant patients who underwent open
or laparoscopic management of appendicitis/cholelithiasis at LDS Hospital from
1990 to 1998 were reviewed. RESULTS: Eighteen open appendectomies (OA) and 13
open cholecystectomies (OC) were performed. Forty-five laparoscopic
cholecystectomies (LC) and 22 laparoscopic appendectomies (LA) were performed
without birth defects, fetal loss or uterine injury. Preterm delivery rates (PTD)
in the LA and OA groups were similar (15.8% versus 11.8%, P>0.9). The PTD rate in
the LC group was not significantly different than in the OC group (11.9% versus
10.0%, P>0.9). Neither birth weights nor Apgar scores were significantly
different across groups. CONCLUSIONS: Laparoscopic management of appendicitis and
symptomatic cholelithiasis during pregnancy can be performed with minimal fetal
and maternal morbidity when accepted management guidelines are followed.
PMID- 10670866
TI - Laparoscopic splenectomy in patients with hematologic malignancies.
AB - BACKGROUND: Although laparoscopic splenectomy (LS) for benign hematologic disease
is well accepted, its role in hematologic malignancies is not clearly defined.
This study examined the efficacy and feasibility of LS for hematologic
malignancies. METHODS: Records were reviewed from patients who underwent LS at
two university hospitals. Charts from 77 open splenectomies for malignancy (OM)
during the same period were also reviewed. RESULTS: Fifty-three patients
underwent LS, 22 for hematologic malignancies (LM) and 31 for benign hematologic
disorders (LB). Median splenic weight was greater in the LM group (930 g) than in
the LB group (164 g, P = 0.001). LM was associated with longer operations and
greater blood loss than was LB. LM had a 41% conversion rate. Morbidity,
mortality, and transfusion rates were similar. Median hospital stay was shorter
for LM (4 days) than for OM (6 days, P = 0.001). CONCLUSIONS: LS is feasible in
hematologic malignancies but is associated with increased operative time and
blood loss and a high conversion rate. Morbidity and mortality, however, was
similar. Shorter hospital stays for LM compared with OM may translate into
earlier recovery and initiation of antineoplastic therapy.
PMID- 10670867
TI - A state-wide evaluation of appendectomy in children.
AB - BACKGROUND: Traditional management of appendicitis in children involves open
appendectomy (OA), an operation that is relatively inexpensive and carries few
risks and complications. However, little information is available regarding the
use, cost, and complication of laparoscopic appendectomy (LA) in children.
METHODS: Our initial aim was to determine if LA is frequently performed in
children (<15 years). We then compared the surgical results of OA versus LA. In
conjunction with the Missouri Department of Health, we evaluated 793 children
treated for appendicitis throughout the state between January 1997 and June 1997.
The authors were blinded to the patient, surgeon, and hospital; no children were
excluded. RESULTS: LA was infrequently performed in children with advanced
disease. Overall, children undergoing LA were older and had a shorter
hospitalization but no difference in hospital charge. When separated by child
age, LA was associated with a shorter length of stay in all groups (0 to 5, 6 to
10, and 11 to 15 years) but only children in the 6 to 10 year range had a lower
hospital charge when compared with patients undergoing OA. CONCLUSIONS: LA is
becoming a common surgical approach for older children with simple appendicitis.
Furthermore, these data suggest that LA, independent of individual surgeon or
medical center, is associated with a decreased length of hospitalization without
a significant difference in hospital charge.
PMID- 10670868
TI - Laparoscopic refundoplications after failed antireflux surgery.
AB - BACKGROUND: Open and laparoscopic antireflux procedures may require reoperation
for failures of the initial procedure in about 3% to 6% of cases. The purpose of
this study is to describe our operative experiences, postoperative results, and
patients' view of outcome following laparoscopic refundoplication. METHODS:
Thirty patients (18 men, 12 women), mean age 56 years (range 37 to 77) underwent
laparoscopic redo surgery. In 18 patients the initial surgery was done by the
open technique, and 3 had surgery twice previously. Twelve patients had previous
laparoscopic antireflux surgery. Indications for redo surgery were recurrent
reflux (n = 17), dysphagia (n = 6), and the combination of both (n = 7). RESULTS:
Twenty-eight patients were completed laparoscopically, 21 with a floppy Nissen
and 7 with a Toupet fundoplication. Two patients were converted to the open
procedure because of intraoperative technical problems. In 5 cases there was an
injury to the stomach wall, successfully managed laparoscopically.
Postoperatively 1 patient had dysphagia and required pneumatic dilatation,
another had gas bloat. There was a significant increase in lower esophageal
sphincter pressure at 3 months (12.4+/-4.8 mm Hg; n = 30) and 1 year (12.3+/-4.5
mm Hg; n = 30). Twenty-four hour pH monitoring showed a decrease of the DeMeester
Score at 3 months after surgery from 14.7+/-10.6 (n = 30) and 1 year after
surgery from 12.1+/-8.7 (n = 30). Gastrointestinal quality of life index
increased from 87 points preoperatively to 121 at 3 months and 123 at 1 year,
which is comparable with a healthy population (123 points). CONCLUSIONS:
Laparoscopic refundoplication is a feasible and effective procedure with
excellent postoperative results, independent of whether the primary procedure was
done by the open or laparoscopic technique.
PMID- 10670869
TI - Surgical management of biliary gallstone disease during pregnancy.
AB - BACKGROUND: Biliopancreatic gallstone disorders (BPD) manifesting during
pregnancy are relatively rare. The management of these conditions remains
controversial. Although perioperative problems and fetal loss have been reported,
recent publications have advocated an early surgical approach. PATIENTS AND
METHODS: Thirty-two pregnant women underwent operation for BPD between January
1993 and December 1997. The mean age was 29 years and ranged from 18 to 41 years.
RESULTS: Twelve patients underwent a laparoscopic cholecystectomy (LC), and 20
open cholecystectomies (OC), including two conversions from laparoscopic. Seven
of the OC patients required additional open CBD exploration and intraoperative
choledochoscopy for CBD stones. No maternal mortality was observed. A single
fetal demise (3%) occurred for a patient with gallstone pancreatitis who
underwent open cholecystectomy during her 14th week of gestation. CONCLUSIONS:
Early involvement of the obstetric team, with preoperative and postoperative
fetal monitoring, and adequate management of anesthetic and tocolytic agents make
cholecystectomy a safe procedure at any stage of pregnancy.
PMID- 10670870
TI - Autologous blood transfusion does not reduce postoperative infection rates in
elective surgery.
AB - BACKGROUND: The influence of blood transfusions in the risk of postoperative
infection remains controversial. We examined the association between autologous
(AB) and homologous (HB) blood transfusions with postoperative infection in
elective surgery. METHODS: The medical records of 991 Medicare patients aged > or
=65 years submitted to hysterectomy and hip and knee replacement were reviewed.
Logistic regression analysis was used to control for age, comorbidity, year, and
type of procedure. RESULTS: Overall, 451 (46%) patients required transfusions. AB
was given to 324 (72%), HB to 94 (21%); 33 (7%) patients received both. Forty-two
patients (4%) developed postoperative infections. The infection rate was not
different among patients receiving HB (7%), AB (5%), AB+HB (0), and nontransfused
patients (4%); P = 0.18). After adjustment for confounders, HB and AB remained
not associated with infections. CONCLUSION: In elective surgery with small volume
transfusion, neither AB nor HB transfusions were associated with an increased
risk of postoperative infections.
PMID- 10670871
TI - Attenuating tumor necrosis factor alpha does not ameliorate other cytokine and
peroxidase products during sepsis.
AB - BACKGROUND: Recent trials utilizing single anticytokine agents have shown no
consistent survival benefit in improving the outcome of sepsis. Since an entire
cascade of mediators contributes to the underlying pathophysiology, it is not
surprising that monotherapy has proven unsuccessful. The purpose of this study
was to measure the effects of attenuating tumor necrosis factor (TNF)alpha early
in sepsis. METHODS: Three groups of Sprague-Dawley rats were studied. All animals
were infused with live Escherichia coli, with group I and group II rats
additionally receiving a matrix metalloproteinase inhibitor. Serum levels of
TNFalpha, interleukin (IL)-6, malondialdehyde (MDA), and lipid hydroperoxide
(LOOH) were compared. RESULTS: TNFalpha showed a significant decrease, yet IL-6,
MDA, and LOOH (markers of sepsis) levels remained abnormally elevated.
CONCLUSION: Despite significantly attenuating TNFalpha, the septic response
continued. This supports the concept that in sepsis, monotherapy directed at
attenuating a single cytokine cannot overcome the tissue-damaging effects of an
entire cascade of mediators.
PMID- 10670872
TI - An evaluation of two methods for chronic central venous access device placement.
AB - BACKGROUND: Chronic venous access devices (CVADs), placed for phlebotomy and the
administration of medications and nutrition, require fluoroscopy to confirm
correct catheter position. Long-term central venous catheters placed using an
electromagnetic catheter locating system (EMCLS) could result in decreased
radiation exposure and decreased cost without compromising accuracy of position.
METHODS: Charts of patients who underwent placement of CVADs at University of New
Mexico (UNM) Hospital or UNM Cancer Center were reviewed. Inclusion criteria
included age >20 years and placement of a central CVAD utilizing fluoroscopy
(group 1) or the EMCLS (group 2). Radiation exposure, complications, cost, and
accuracy of placement were determined for each technique. RESULTS: Between June
1996 and June 1998, 196 patients underwent placement of CVADs. Complete data sets
were available for 46 patients in each group. There were no statistically
significant differences in age, gender, complications, or operating room times (P
= 0.26). Fluoroscopy and EMCLS were equally accurate for the correct placement of
the tip of the line (P = 0.12). Mean patient radiation exposure was EMCLS, 30
mRem, and fluoroscopy, 771 mRem. EMCLS significantly decreased cost (P = 0.025)
when compared with fluoroscopic assisted catheter placement. CONCLUSIONS: The use
of EMCLS for CVAD placement reduces radiation exposure and cost without
compromising the accuracy of placement when compared with standard fluoroscopic
assisted placement.
PMID- 10670873
TI - Release of anti-inflammatory mediators after major torso trauma correlates with
the development of postinjury multiple organ failure.
AB - BACKGROUND: Soluble tumor necrosis factor receptor (sTNFr) and interleukin-1
receptor antagonist (IL-1ra) have been identified as endogenous inhibitors of TNF
alpha and IL-1beta. While TNF-alpha and IL-1beta levels are not systematically
elevated in postinjury patients who developed multiorgan failure (MOF), their
involvement at the tissue level has been suggested. Our study hypothesis was that
levels of sTNFr-I and IL-1ra would discriminate patients at risk for postinjury
MOF. METHODS: Serial plasma levels of sTNFr and IL-1ra were measured in 29 trauma
patients at high risk for postinjury MOF. RESULTS: sTNFr-I levels were higher in
MOF compared with non-MOF patients at 12, 84, and 132 hours postinjury. MOF
patients also had higher IL-1ra values 36, 60, 84, and 132 hours postinjury.
CONCLUSIONS: Anti-inflammatory mechanisms are activated after trauma. Since
increased levels of sTNFr and IL-1ra correlate with postinjury MOF, they may
contribute to our understanding of the pathogenesis as well as prediction of
outcome. High levels of antagonists to TNF-alpha and IL-1beta suggest tissue
level involvement of these cytokines in postinjury hyperinflammation.
PMID- 10670874
TI - Age of transfused blood is an independent risk factor for postinjury multiple
organ failure.
AB - BACKGROUND: Blood transfusion has repeatedly been demonstrated to be an
independent risk factor for postinjury multiple organ failure (MOF). Previously
believed to represent a surrogate for shock, packed red blood cell (PRBC)
transfusion has recently been shown to result in neutrophil priming and pulmonary
endothelial cell activation. We have previously observed that the generation of
inflammatory mediators is related to the length of PRBC unit storage. The purpose
of this study was to determine if age of transfused PRBC is a risk factor for the
development of postinjury MOF. METHODS: Using our prospective database of trauma
patients at risk for developing MOF, we identified patients who developed MOF
(MOF+) and received 6 to 20 units of PRBCs in the first 12 hours following
injury. A similar cohort of patients, matched for ISS and transfusion
requirement, who did not develop MOF (MOF-) were also identified. The age of each
unit of PRBC transfused in the first 6 hours was determined. Multiple logistic
regression was performed to determine if age of transfused blood is an
independent risk factor. RESULTS: Sixty-three patients were identified, 23 of
whom were MOF+. There was no difference in ISS and transfusion requirement
between MOF+ and MOF- groups. MOF+ patients, however, were significantly older
(46+/-4.7 years versus 33+/-2.3 years). Moreover, mean age of transfused blood
was greater in the MOF+ patients (30.5+/-1.6 days versus 24+/-0.5 days).
Similarly, the mean number of units older than 14 and 21 days old were greater in
the MOF+ patients. Multivariate analysis identified mean age of blood, number of
units older than 14 days, and number of units older than 21 days as independent
risk factors for MOF. CONCLUSION: The age of transfused PRBCs transfused in the
first 6 hours is an independent risk factor for postinjury MOF. This suggests
that current blood bank processing and storage technique should be reexamined.
Moreover, fresh blood may be more appropriate for the initial resuscitation of
trauma patients requiring transfusion.
PMID- 10670875
TI - Attenuation of renal ischemia-reperfusion injury with selectin inhibition in a
rabbit model.
AB - BACKGROUND: The selectin glycoproteins are involved in the pathogenesis of renal
ischemia-reperfusion injury. We investigated the ability of glycyrrhizin, a known
selectin inhibitor, to attenuate renal ischemia-reperfusion injury. METHODS:
Eighteen New Zealand white rabbits underwent midline laparotomy with renal artery
cross-clamping. After 30 minutes of reperfusion, group 1 (control, n = 10)
animals received a saline infusion, while group 2 (GLY, n = 8) animals received a
glycyrrhizin infusion. Renal function was compared between the two groups after
72 hours of reperfusion. A t test was utilized, with alpha set at P<0.05.
RESULTS: Group 1 and group 2 animals had similar baseline renal function.
However, after 72 hours of reperfusion, group 1 animals had a significantly
higher mean blood urea nitrogen creatinine ratio than group 2 animals (P<0.01),
indicating preserved renal function in rabbits treated with glycyrrhizin.
CONCLUSIONS: Selectin blockade using glycyrrhizin attenuates renal ischemia
reperfusion injury when given 30 minutes after the onset of reperfusion in a
rabbit model.
PMID- 10670876
TI - Fibrin glue reduces the severity of intra-abdominal adhesions in a rat model.
AB - BACKGROUND: The purpose of this study was to determine whether fibrin glue
inhibits intra-abdominal adhesions. METHODS: Twenty rats underwent midline
laparotomy. To maximize adhesions, bilateral peritoneal muscular defects were
created and covered with polypropylene mesh sewn with a braided suture. The bowel
was abraded with dry gauze. Rats were randomized to either fibrin glue (FG)
sprayed over the mesh or to control (no further treatment) groups. At 1 week, the
adhesion density (graded 0 to 3), the percentage of the patch covered by adhesion
(0% to 100%), and adhesion type were recorded. RESULTS: The mean adhesion density
was 1.45+/-0.33 for FG versus 2.8+/-0.11 for controls (P = 0.001). The mean
percentage of adhesions was 36+/-9.9 for the FG group and 94+/-3.7 for controls
(P = 0.0002). Bowel or solid organs were adherent to the patch in 6 of 20 (30%)
in the FG group versus 12 of 20 (70%) in controls (P = 0.057). CONCLUSIONS:
Topical fibrin glue reduces the density and severity of intra-abdominal adhesions
in a rat model.
PMID- 10670877
TI - Splenectomy in high-risk patients with splenomegaly.
AB - BACKGROUND: Splenectomy in patients with massive splenomegaly and hematologic
malignancy results in higher morbidity and mortality with primarily palliative
benefit. METHODS: From a 14-year experience with 172 splenectomies, the
perioperative course of 39 high-risk patients with splenomegaly was reviewed for
comorbidities, indications, complications, and mortality. RESULTS: Twenty-three
males and 16 females with a mean age of 54.2 years and a mean 12.8-day
postoperative length of stay were reviewed. Sixteen patients (41%) had 23 major
complications related to age (P = 0.047) and operative time (P = 0.01).
Intraoperative transfusion was related to splenic size (P = 0.04), and estimated
blood loss (P = 0.02) was inversely related to use of splenic artery preligation.
Three perioperative deaths were secondary to sepsis and multi-organ system
failure. CONCLUSION: Splenomegaly and comorbidities of the primary disease result
in higher morbidity and mortality. Splenic artery preligation is valuable to
limit intraoperative blood loss and facilitate splenectomy.
PMID- 10670878
TI - Total colectomy versus limited colonic resection for acute lower gastrointestinal
bleeding.
AB - BACKGROUND: Acute lower gastrointestinal bleeding (ALGB) of the colon can be
problematic to diagnose. The purpose of this study was to review our experience
with ALGBs and to determine any differences between limited colon resection (LCR)
and total/subtotal colon resection (TCR). METHODS: A retrospective study located
77 patients with ALGB, who required 2 or more units of packed red blood cells
prior to surgery, and who were taken to the operating room from 1987 to 1997.
RESULTS: Fifty LCRs and 27 TCRs were performed during this 10-year period.
Recurrent bleeding was significantly more common in the LCR group than in the TCR
group (18% versus 4%). Morbidity and mortality were not significantly different.
CONCLUSIONS: Owing to the misconception of a higher morbidity with TCR, it has
been considered a "last resort" instead of a more expeditious therapy with
similar morbidities and mortalities. TCR should be considered more often in the
management of these patients.
PMID- 10670879
TI - Intraoperative radiofrequency ablation or cryoablation for hepatic malignancies.
AB - BACKGROUND: The majority of patients with primary or metastatic malignancies
confined to the liver are not candidates for resection because of tumor size,
location, multifocality, or inadequate functional hepatic reserve. Cryoablation
has become a common treatment in select groups of these patients with
unresectable liver tumors. However, hepatic cryoablation is associated with
significant morbidity. Radiofrequency ablation (RFA) is a technique that destroys
liver tumors in situ by localized application of heat to produce coagulative
necrosis. In this study, we compared the complication and early local recurrence
rates in patients with unresectable malignant liver tumors treated with either
cryoablation or RFA. PATIENTS AND METHODS: Patients with hepatic malignancies
were entered into two consecutive prospective, nonrandomized trials. The liver
tumors were treated intraoperatively with cryoablation or RFA; intraoperative
ultrasonography was used to guide placement of cryoprobes or RFA needles. All
patients were followed up postoperatively to assess complications, treatment
response, and local recurrence of malignant disease. RESULTS: Cryoablation was
performed on 88 tumors in 54 patients, and RFA was used to treat 138 tumors in 92
patients. Treatment-related complications, including 1 postoperative death,
occurred in 22 of the 54 patients treated with cryoablation (40.7% complication
rate). In contrast, there were no treatment-related deaths and only 3
complications after RFA (3.3% complication rate, P<0.001). With a median follow
up of 15 months in both patient groups, tumor has recurred in 3 of 138 lesions
treated with RFA (2.2%), versus 12 of 88 tumors treated with cryoablation (13.6%,
P<0.01). CONCLUSIONS: RFA is a safe, well-tolerated treatment for patients with
unresectable hepatic malignancies. This study indicates that (1) complications
occur much less frequently following RFA of liver tumors compared with
cryoablation of liver tumors, and (2) early local tumor recurrence is infrequent
following RFA.
PMID- 10670880
TI - Isoperistaltic bowel lengthening for short bowel syndrome in children.
AB - BACKGROUND: Short bowel syndrome, secondary to a variety of causes, can be lethal
in infancy and childhood. Isoperistaltic bowel lengthening, performed by
longitudinal division of dilated small bowel with end-to-end anastomosis, has
shown early promise but long-term outcome is unknown. METHODS: Sixteen infants
and children (aged 3 months to 14 years) had short bowel syndrome from
necrotizing enterocolitis (8), gastroschisis (4), atresia (2), and volvulus (2).
All of these patients were partially or totally dependent on parenteral nutrition
and have undergone isoperistaltic bowel lengthening for short bowel syndrome
(length <100 cm). Bowel length was increased by 22% to 85% (mean 42%) with the
procedure. Studies of intestinal function were performed preoperatively and
postoperatively. RESULTS: Isoperistaltic bowel lengthening resulted in
significant improvement in stool counts, intestinal transmit time, intestinal
clearance of barium, D-xylose absorption, and fat absorption at 6 months and 12
months postoperatively. Fourteen of 16 patients (88%) have been weaned from
parenteral nutrition. CONCLUSIONS: These data show that isoperistaltic bowel
lengthening can be an effective operation for short bowel syndrome in children,
improving absorption and motility, and allowing weaning from parenteral
nutrition.
PMID- 10670881
TI - Bone substitutes.
AB - The search for the ideal bone substitute began hundreds of years ago, and
continues today. While numerous choices have been proposed and tested, with
varying degrees of success, there remain many challenges related to the use of
bone substitutes in craniofacial reconstruction. This paper presents a review of
the history of bone substitute research, a discussion of currently popular
materials, and elucidation of the challenges to be faced as we approach the new
millennium.
PMID- 10670882
TI - A new technique for the quantitative analysis of cranial suture biology.
AB - OBJECTIVE: Our objective was to assess the ability of the microcomputed
tomography scanner to correctly image normal and synostosed cranial sutures at
the ultrastructural level. DESIGN AND METHODS: Two specimens of coronal sutures
were collected from operative specimens. After appropriate preparation,
histological sections were obtained and stained with toluene blue for evaluation.
Representative histological sections were compared to microcomputed tomography
slices. RESULTS AND CONCLUSIONS: With microcomputed tomography, we successfully
imaged one normal and one synostosed human coronal suture and performed a
quantitative analysis of these specimens. Microcomputed tomography scanning was
found to be a highly accurate imaging device for the evaluation of cranial suture
development. Microcomputed tomography offers three-dimensional imaging at the
microscopic level and allows for rapid quantitative analysis of bone
architecture, including several measurements unavailable through histologic
analysis. We believe that microcomputed tomography can play an important role in
imaging and in the quantitative analysis of the stereology of bone
microarchitecture. Among its advantages, microcomputed tomography is able to
image many more slices than are obtainable through histology, and the method is
not prone to human error. Microcomputed tomography slices are generated without
destruction of the specimen and without loss or corruption of reproducible data.
Structure-oriented slices from microcomputed tomography together with cellular
oriented sections from histology are complementary in the overall quantitative
analysis of cranial sutures.
PMID- 10670883
TI - Dentoalveolar relations in children born with a unilateral cleft lip and palate
(UCLP) in Western Australia.
AB - OBJECTIVE: Our objective was to evaluate complete unilateral cleft lip and palate
repair outcome in the Cleft Unit in Perth, Western Australia, by assessment of
dentoalveolar relationships. DESIGN: This is a retrospective study. SETTING: Our
subjects were individuals under the care of the cleft team in Perth, Western
Australia. PARTICIPANTS: All patients with unilateral cleft lip and palate and
available 6-year casts who had been born since January 1, 1985, were identified
from the cleft unit's database. The nature of the cleft was verified by
examination of birth study models and photographs. A total of 54 such patients
were identified. MAIN OUTCOME MEASURES: Main outcome measures were identified
through dental arch relationship grading of study models using the 5 Year Old
Study Model Index. RESULTS: Interexaminer and intraexaminer agreement kappa
statistics revealed good to very good agreement using this index. The results
indicate that the surgical outcome was graded as excellent, good, or fair for 77%
of patients and poor or very poor for 23% of patients. CONCLUSIONS: The results
of the Western Australia study compare favorably to the overall U.K. outcome (the
Clinical Standards Advisory Group study) but unfavorably to the results of some
European centers, such as Oslo.
PMID- 10670884
TI - The adult unoperated cleft patient: absence of maxillary teeth outside the cleft
area.
AB - OBJECTIVE: The purpose of this study was to investigate the possible absence of
teeth in the postcanine region of the upper jaw of the unoperated adult cleft
patient. METHOD: The study was performed on 266 dental casts of fully unoperated
adult cleft patients. The patients were divided into four groups according to the
type of the cleft: unilateral cleft lip and alveolus, unilateral cleft lip and
palate, bilateral cleft lip and alveolus, and bilateral cleft lip and palate.
RESULTS: No absence of permanent teeth in the canine and postcanine area of the
upper jaw could be found. CONCLUSION: The results are in contradiction with the
established hypothesis that absence of teeth outside the cleft area of the
maxilla is due to an unknown congenital factor. On the contrary, the findings
support the hypothesis that surgery for the closure of the hard palate in early
childhood is the most important etiological factor for the absence of teeth
outside the cleft area in the early operated cleft patient. The superficial
position of the tooth germs (at the time of the palatal surgery), especially
those of the premolars, supports this hypothesis.
PMID- 10670885
TI - Radiographic determination of the position of the maxillary lateral incisor in
the cleft alveolus and parameters for assessing its habilitation prospects.
AB - OBJECTIVE: Develop patient selection criteria and guidelines for the diagnostic
work-up for early secondary alveolar bone graft designed to accommodate a lateral
incisor in the cleft. DESIGN: A literature review with clinical examples.
INTERVENTIONS: For the majority of cleft lip and palate (CLP) patients, the
timing of the secondary alveolar bone graft procedure is devised to accommodate
the eruption of the maxillary canine. However, when the lateral incisor is
present in the cleft area, a decision may be made to perform early grafting in
order to salvage an additional tooth. Appropriate case selection for this
intervention is the key for successful dental habilitation in the cleft area.
RESULTS AND CONCLUSIONS: Attempts to maintain the lateral incisor are recommended
only if the tooth contributes to the comprehensive orthodontic and restorative
patient care and when the presence of a lateral incisor with adequate size,
shape, and proper position may be demonstrated. For optimal decision making, the
position, form, and periodontal ligament support of the lateral incisor should be
assessed. Evaluation of these parameters is based chiefly on radiographic
imaging. Occlusal projections and traditional tomography may augment the
information available from periapical and panoramic radiographs. However, each of
these has benefits and drawbacks that require consideration.
PMID- 10670886
TI - The basis for presurgical orthopedic treatment of infants with unilateral
complete cleft lip and palate.
AB - OBJECTIVE: The purpose of this study was to describe the posttreatment morphology
of the upper part of the oral cavity of complete unilateral cleft lip and palate
(UCLP) patients and to compare it to noncleft contemporaries. Patients were
treated according to a protocol designed to keep a proper resting posture of the
oral cavity. DESIGN: Retrospective study on dental casts. SETTING: The study was
performed at a maxillofacial center serving a population of 2 million
inhabitants. Data for noncleft subjects are the result of a longitudinal study at
the same institution. PATIENTS: Twenty-one Caucasian UCLP patients (13 males, 8
females) aged 5 to 9 years with no other congenital anomalies and no
postoperative orthodontic treatment. INTERVENTIONS: Each patient received 5 to 6
months of preoperative orthopedics with a passive plate and external nonelastic
strapping with definitive lip repair at age 5 to 7 months, soft palate repair at
11 to 15 months, and hard palate repair with mucoperiosteal closure of the
alveolus at 30 to 36 months. Each patient was compared to the mean values
obtained from a longitudinal study of a group of 25 healthy noncleft children of
the same ethnic group (11 males, 14 females). RESULTS: Analysis of dental casts
indicated that 16 patients had a width, depth, and length of the alveolar arch in
the range of the mean normal values minus two standard deviations. Their analyzed
palates were flatter than normal. Six of 21 children had too small an alveolar
arch for their ages, and they did not acquire a correct posture of the oral
cavity. CONCLUSION: The results indicate that the upper part of the oral cavity
of UCLP patients can reach the dimensions of noncleft contemporaries despite
surgery.
PMID- 10670887
TI - Genetics of nonsyndromic cleft lip and palate: a review of international studies
and data regarding the Italian population.
AB - The aims of this review are (1) to illustrate current knowledge of the mode of
inheritance and the loci involved in the cleft lip and palate and (2) to
summarize the results of our investigations, which were carried out in Italy. It
is well established that nonsyndromic cleft of the lip with or without the palate
(CL+/-P) and cleft palate only (CPO) are separate entities. Genetic heterogeneity
has been observed in CL+/-P, which involves different chromosome regions, mainly
6p23 (OFC1), 2q13 (OFC2), and 19q13.2 (OFC3), as well as other loci, such as 4q25
4q31.3 and 17q21. Furthermore, an interaction between different genes has been
suggested in the oligogenic model. In one case at least, an OFC1 and OFC2
interaction has been demonstrated. The mode of inheritance of CPO is compatible
with a recessive single major gene model, while an association with a candidate
gene, mapping on the chromosome region 2q13/TGFalpha, remains to be confirmed.
PMID- 10670888
TI - Associated malformations in cases with oral clefts.
AB - OBJECTIVE: Infants with oral clefts (OCs) often have other associated congenital
defects. The reported incidence and the types of associated malformations vary
between different studies. The purpose of this investigation was to assess the
prevalence of associated malformations in a geographically defined population.
METHOD: The prevalences at birth of associated malformations in infants with OCs
were collected between 1979 and 1996 on all infants born in the area covered by
the registry of congenital anomalies of Northeastern France in 238,942
consecutive births. RESULTS: Of the 460 cleft infants born during this period,
36.7% had associated malformations. Associated malformations were more frequent
in infants who had cleft palate (46.7%) than in infants with cleft lip and palate
(36.8%) or infants with isolated cleft lip (13.6%). Malformations in the central
nervous system and in the skeletal system were the most common other anomalies,
followed by malformations in the urogenital and cardiovascular systems. Weight,
length, and head circumference of children with OCs and multiple associated
malformations were lower than in controls, as was the weight of the placenta.
Prenatal diagnosis was rarely done by fetal ultrasonographic examination in
isolated clefts. However, even in multiple associated malformations, prenatal
diagnosis by fetal ultrasonographic examination had a low sensitivity, 31.6%.
CONCLUSION: The overall prevalence of malformations, which was one in more than
three infants, emphasizes the need for a thorough investigation of infants with
clefts. A routine screening for other malformations especially skeletal, central
nervous system, and cardiac defects may need to be considered in infants with
clefts, and genetic counseling seems warranted in most of these complicated
cases.
PMID- 10670889
TI - A three-dimensional quantitative analysis of lips in normal young adults.
AB - OBJECTIVE: To supply information about (1) sex-related dimensions (linear
distances and ratios, vermilion area, volume) of normal adult lips, (2) presence
of sexual dimorphism, and (3) correlations between anthropometric characteristics
of the lip and nose. METHODS: The three-dimensional coordinates of soft tissue
landmarks on the lips and nose were obtained using an optoelectronic instrument
in 90 healthy young adult women and 90 healthy young adult men. From the
landmarks, several linear distances (mouth width, total vermilion height, nose
height, anatomic nose width, total lip height, upper lip height), the ratio of
vermilion height to mouth width, and some areas (vermilion of the upper lip,
vermilion of the lower lip, total vermilion) and volumes (upper lip volume, lower
lip volume, total lip volume) were calculated. Linear correlation analyses
between pairs of variables were also conducted within each sex. RESULTS: All lip
dimensions (distances, areas, and volumes) were significantly larger in men than
in women (p<.005), but no sex differences were found in the vermilion height to
mouth width ratio. Overall, mouth and nose dimensions were not significantly
correlated, with the exceptions of the upper and lower lip volumes in both sexes
and of the mouth and nose widths in the female sample, in which a modest part of
the variance in one measurement could be explained by the other. CONCLUSION: The
dimensions of the mouth and the nose did not seem to be strictly related. Data
collected in the present investigation could represent a database for the
quantitative description of human lip morphology in adult subjects.
PMID- 10670890
TI - Histological evaluation of autogenous iliac particulate cancellous bone and
marrow grafted to alveolar clefts--a preliminary report of five young adult
cases.
AB - OBJECTIVE: We histologically evaluated iliac particulate cancellous bone and
marrow (PCBM) grafted to alveolar clefts in five young adults with cleft lip and
palate. PATIENTS AND METHODS: Five young adults with cleft lip and palate
underwent secondary alveolar bone grafting. The mean age of the patients was 21.2
years (range = 17 to 27 years). Bone specimens were taken from the graft site 5
to 10 months after the surgery simultaneously with implant fixture placement (two
cases), vestibuloplasty (two cases), and rebone grafting (one case). These five
bone specimens were prepared and stained with hematoxylin and eosin and examined
microscopically. RESULT: One specimen, taken 5 months after surgery, showed
immature trabecular bone partially lined by osteoblasts. The remaining four
specimens showed well-mineralized trabeculae and fatty change in the marrow
space. CONCLUSION: In young adult cases, PCBM remodeled after grafting and became
mature bone about 5 to 6 months after the surgery.
PMID- 10670891
TI - Laryngeal airway resistance in cleft palate children with complete and incomplete
velopharyngeal closure.
AB - OBJECTIVE: This study investigated the effect of velopharyngeal insufficiency on
aerodynamic measures of laryngeal function in children with cleft palate. DESIGN:
Data were analyzed using analysis of covariance. The independent variable was
velopharyngeal closure, and the dependent variables were laryngeal resistance,
laryngeal airflow, and transglottal pressure. Age and gender were covariates.
SETTING: The data were collected at The Craniofacial Center, University of
Illinois, a tertiary health care center located in Chicago. PATIENTS: Thirty-six
children with cleft palate were recruited from among the patients at The
Craniofacial Center. Ten children with velopharyngeal areas >5 mm2 during oral
speech were placed in the incomplete closure group, while 26 children with areas
<1 mm2 were placed in the complete closure group. OUTCOME MEASURES: The three
dependent variables (transglottal pressure, transglottal airflow, and laryngeal
resistance) were measured. RESULTS: Laryngeal resistance and transglottal
pressure were significantly higher, and transglottal airflow was significantly
lower in the group with complete closure. CONCLUSIONS: In summary, cleft palate
patients with complete velopharyngeal closure exhibited higher laryngeal
resistances than those with incomplete closure.
PMID- 10670892
TI - Mental development in infants with cleft lip and/or palate.
AB - OBJECTIVE: Investigated mental development in infants and toddlers with cleft lip
and/or palate (CLP). DESIGN: This was a retrospective analysis of developmental
scores on qualified children between 4 and 36 months of age. Cross-sectional
analysis included children in four age groups (6, 12, 18, and 24 months);
longitudinal analysis included children at mean age 9.1 (range = 4 to 15) months
at Time 1 and 24 months (range = 16 to 36) at Time 2. PARTICIPANTS: Cross
sectional analysis included 180 children (59% male participants) in four
diagnostic groups (cleft lip only [CL], cleft lip and palate [CLP], cleft palate
only [CP], and Pierre Robin). The longitudinal sample included 85 children (64%
male children) in the same diagnostic groups. MAIN OUTCOME MEASURES: Mental Scale
(MDI) of the Bayley Scales of Infant Development. RESULTS: Mean MDIs were in the
average range but decreased significantly between youngest and oldest groups in
both cross-sectional (F(3,179) = 4.9, p<.01) and longitudinal samples (F(1,84) =
6.87, p<.01). There was a significant difference among cleft types (F(3,179) =
3.5, p<.025). Infants with CL obtained the highest scores, and infants with
Pierre Robin Sequence obtained the lowest. Perceptual-motor development in the
first year of life was predictive of developmental status at age 2. CONCLUSIONS:
The number of children with CLP who may be at risk for developmental problems
during the second year of life is greater than would be expected. Children at
greatest risk may demonstrate early delays in acquisition of perceptual-motor
skills during the first year of life.
PMID- 10670893
TI - Facial growth in a cleft palate patient treated with the Herbst appliance: a long
term profile roentgenographic and roentgen stereometric analysis of profile
changes and displacement of the jaws.
AB - OBJECTIVE: To monitor facial development in a patient with cleft palate who was
treated with the Herbst appliance. Monitoring was in terms of changes in the
skeletal profile and growth in the circummaxillary sutures and temporomandibular
joints (TMJs). DESIGN: Prospective profile roentgenography (between the ages of 6
and 20 years) and roentgen stereometric analysis (between the ages of 8 and 19
years). SETTING: Center for Craniofacial Anomalies and Department of Plastic and
Reconstructive Surgery, Malmo University Hospital, Malmo, Sweden. PATIENT: Boy
with cleft of the soft and posterior part of the hard palate and marked facial
convexity. INTERVENTIONS: Surgical repair of the soft palate at age 9 months,
velopharyngeal flap at age 8 years, and insertion of implants under general
anesthesia and treatment with the Herbst appliance at age 11 years. Roentgen
examinations were performed in connection with continued clinical evaluations and
treatment. MAIN OUTCOME MEASURES: Profile roentgenograms were traced and measured
by one of the authors using conventional point-based analysis. Stereo
roentgenograms were digitized by the Department of Orthopedic Surgery, Malmo
University Hospital. RESULTS: The direction of profile changes was partly
discordant with the direction of articular growth in the circummaxillary sutures
and TMJs. The successful treatment result was accomplished by a temporary
influence on sagittal growth direction in the circummaxillary sutures and on
rotational growth direction in the TMJs, combined with a favorable natural
remodeling and articular growth pattern. CONCLUSIONS: The mode of growth by which
treatment aims were reached was partly unexpected, i.e., discordant with the
generally accepted principal concept that treatment with the Herbst appliance
positions the mandible forward.
PMID- 10670894
TI - Crouzon syndrome with acanthosis nigricans: case report and mutational analysis.
AB - OBJECTIVE: To describe the 22nd case of Crouzan syndrome with acanthosis
nigricans, a hyperkeratotic skin disorder with hyperpigmentation. METHODS: DNA
analysis and sequencing of the FGFR3 gene were performed. RESULTS: The 13-year
old Japanese boy described here also had dyspnea, facial palsy, sensorineural
hearing loss, and skeletal and mental retardation. Examination of a skin biopsy
specimen revealed the typical findings of acanthosis nigricans. Genetic analysis
revealed the Ala391Glu mutation in one FGFR3 gene. CONCLUSIONS: Crouzon syndrome
with acanthosis nigricans is a distinct clinical entity different from classic
Crouzon syndrome.
PMID- 10670895
TI - Epignathus teratoma: report of three cases with a review of the literature.
AB - Three cases of epignathus teratoma associated with other midline anomalies are
reported. The first case involved Pierre Robin sequence and a bifid tongue. The
second case was characterized by two teratomas, a meningoencephalocele, and a
cleft lip and nose. The third case had Pierre Robin sequence associated with
duplication of the pituitary gland and hypoplasia of the corpus callosum.
PMID- 10670896
TI - Effects of maxillary protraction combined with chin-cap therapy in unilateral
cleft lip and palate patients.
AB - OBJECTIVE: This study investigated the treatment effects of maxillary protraction
combined with chin-cap therapy in complete unilateral cleft lip and palate
patients at the deciduous and early mixed dentition stages. METHOD: Twenty-six
Japanese children (10 boys and 16 girls) with complete unilateral cleft lip and
palate were examined. All had undergone pushback operations for palatal repair at
approximately 18 months of age. Maxillary protraction began between 5 and 7 years
of age and continued for 10 to 38 months. Lateral cephalograms were used to
analyze skeletal changes during the first and second years of treatment, and the
relationship between pretreatment midfacial morphology and forward displacement
of the maxilla during the first year was investigated. RESULTS AND CONCLUSIONS:
During the first year of treatment, the mean increase in the ANB angle for all
cases was 2.37 degrees. The forward displacement of the maxilla varied
considerably, from 0.23 mm to 3.03 mm. The treatment response was significantly
smaller in the second year, and no benefit from treatment longer than 1 year was
established. The amount of maxillary forward displacement was significantly
correlated with the pretreatment posterior upper facial height. Patients with
smaller posterior upper facial height showed a poorer treatment response, whereas
patients with a greater posterior upper facial height responded better to
treatment. Individual differences in maxillary growth acceleration may be related
to growth inhibition associated with postsurgical scar tissue on the palates.
PMID- 10670897
TI - Combined bone grafting and delayed closure of the hard palate in patients with
unilateral cleft lip and palate: facilitation of lateral incisor eruption and
evaluation of indicators for timing of the procedure.
AB - OBJECTIVE: To compare outcomes of bone grafting performed before eruption of the
lateral incisor to outcomes of grafting performed before eruption of the canine
and to evaluate the long-term results of bone grafting combined with delayed
closure of the hard palate during mixed dentition. DESIGN: Seventy consecutive
patients (52 men and 18 women) with complete unilateral cleft lip and palate were
studied. All patients underwent bone grafting with simultaneous closure of the
cleft in the hard palate at the stage of mixed dentition. The velum had been
repaired in infancy. Mean age for the bone grafting procedure was 8.4 years. Bone
grafting was performed to facilitate eruption of the lateral incisor in 43 (61%)
of the patients and to facilitate eruption of the canine in the remaining 27
(39%) patients. Intraoral radiographs were used to evaluate the morphologic
characteristics of the cleft and the stage of eruption of the permanent lateral
incisor and canine before bone grafting. Mean follow-up time was 4.0 years
(range, 1-10.1 years). RESULTS: The mean time for the surgery, which included
bone grafting and repair of the residual cleft in the hard palate, was 109
minutes, and the mean amount of bleeding was 121 ml. The rate of dehiscence in
the flap covering the alveolar bone graft was 14%, and the rate of total failure
of bone grafting was 3%. An oronasal fistula developed in the hard palate of 13%
of patients, but the fistula was of sufficient size to serve as an indication for
reoperation in only 6%. The postoperative alveolar bony height in the cleft area
was more than 75% of the normal height in 94% of patients. Closure of the cleft
space in the dental arch was performed or planned to be achieved orthodontically
in 91% of patients. When bone grafting was performed to facilitate eruption of
the lateral incisor, the cleft space was closed orthodontically in 100% of
patients. The optimal indicator for timing of the bone grafting procedure from an
orthodontic point of view was when the permanent lateral incisor or the canine
close to the cleft was covered by a thin shell of bone (i.e., 7-9 years of age).
PMID- 10670898
TI - NMR determination of dynamic parameters of CH3 groups in P(CH3)4SbCl6.
AB - The longitudinal relaxation time T1 and the second moment M2 of 1H NMR line in a
wide temperature range have been measured for P(CH3)4SbCl6. It was found that two
different methyl groups in each tetramethylphosphonium cation perform two
different rates of C3 motions. The reduction of the proton second moment M2 just
below the temperature of the phase transition Tc2 = 350 K may suggest that the
isotropic tumbling of the whole cation [P(CH3)4]+ is involved in the structural
change of the crystal lattice induced by the movements of the [SbCl6]- anion.
PMID- 10670899
TI - CP-MAS 207Pb with 19F decoupling NMR spectroscopy: medium range investigation in
fluoride materials.
AB - The isotropic chemical shift of 207Pb is used to perform structural
investigations of crystalline fluoride compounds (PbF2, Pb2ZnF6, PbGaF5,
Pb3Ga2F12 and Pb9Ga2F24) and transition metal fluoride glasses (TMFG) of the PZG
family (PbF2-ZnF2-GaF3). Using 207Pb Cross Polarisation Magic Angle Spinning (CP
MAS) NMR with 19F decoupling, it is shown that the isotropic chemical shift of
207Pb varies on a large scale (1000 ppm) and that the main changes of its value
are not due to the nearest neighbour fluorines but may be related to the number
of next nearest neighbour (nnn) Pb2+ ions. In this way, it is demonstrated that
207Pb chemical shift is an interesting probe to investigate medium range order in
either crystalline or glassy fluoride systems. The 207Pb delta(iso) parameter has
been linearly correlated to the number of nnn Pb2+ ions.
PMID- 10670900
TI - Proton magnetic resonance microimaging of human trabecular bone.
AB - Proton magnetic resonance (1H magnetic resonance imaging (MRI)) images of human
trabecular bone were acquired and discussed for two samples with different
porosity. Three-dimensional 3D Spin Echo (3D SE) and Multi-Slice Multi-Echo
(MSME) pulse sequences were examined. A very high slice resolution of (38
microm)2 was achieved (MSME). The intensity histograms were found useful for the
characterization of the bone porosity. A spatial distribution of the spin-spin
relaxation time T2 was monitored with the MSME pulse program. The work
demonstrates the great potential of the proton MRI technique in the study of the
trabecular bone morphology.
PMID- 10670901
TI - NMR microscopy of polyurethane foams.
AB - NMR microimaging has been applied to the characterization of foam materials, in
order to understand their properties and gain deeper insight into their
structures. The structure of "open cell" foams can be visualized with sufficient
resolution to obtain the size and shape of cells, as well as their spatial
distribution within specimens. Statistics of cell sizes have been calculated from
NMR microscopy and are in good agreement with results obtained from electron
microscopy. We demonstrate that the local density of foams, which are parameters
largely inaccessible by other analytical methods, readily can be determined by
NMR microscopy.
PMID- 10670902
TI - 207Pb NMR of minium, Pb3O4: evidence for the [Pb2]4+ ion and possible
relativistic effects in the Pb-Pb bond.
AB - Solid Pb3O4 has been studied with 207Pb nuclear magnetic resonance (NMR)
spectroscopy. The 207Pb NMR chemical-shift tensor of the Pb2+ site has principal
values of delta11 = 1980 +/- 5 ppm, delta22 = 1540 +/- 5 ppm, and delta33 = -1108
+/- 10 ppm; delta(iso) = 804 +/- 10 ppm. The chemical-shift tensor of the Pb4+
site is axial, with principal values delta(parallel) = -1009 +/- 3 ppm and
delta(perpendicular) = 1132 +/- 3 ppm; delta(iso) = -1091 +/- 3 ppm. The Pb4+
Pb2+ scalar coupling constant J(Pb-Pb) = 2.3 +/- 0.1 kHz. The main contribution
to the Pb2- chemical-shift anisotropy is proposed to arise from an exchange
interaction in the Pb2+-Pb2+ pairs, conventionally regarded as molecular [Pb2]4+
ions.
PMID- 10670903
TI - 6Li and 7li solid-state NMR spectroscopy of nitrogen ceramic phases.
AB - Two nitrogen ceramic phases, the oxynitride LiSiON and the nitride LiSi2N3, have
been studied by 6Li and 7Li NMR. Magic angle spinning (MAS) NMR experiments have
been carried out at two magnetic field strengths (7.05 and 14.1 T). The spectra
give evidence of the relative effects of the quadrupolar and chemical shift
interactions. The electric field gradient tensor of both phases has been
determined accurately by iterative fitting of the 6Li and 7Li MAS NMR line shapes
at the two magnetic field strengths. Due to the fact that for 7Li the quadrupolar
interaction is much larger than the chemical shift interaction, it is shown that
neither the small chemical shift anisotropy nor the relative orientation of the
two interaction tensors can be determined accurately by 7Li MAS NMR. For 6Li, the
two interactions are comparable and the value of these parameters obtained from
the fits of the 6Li experimental MAS line shapes are therefore much more
reliable.
PMID- 10670904
TI - 207Pb chemical shift thermometer at high temperature for magic angle spinning
experiments.
AB - The temperature dependence of 207Pb chemical shift in magic angle spinning (MAS)
NMR spectrum of Pb(NO3)2 provides a sensitive method to calibrate sample
temperatures in MAS NMR. The temperature dependence is uniform in the temperature
range between 30 degrees C and 400 degrees C. The NMR sensitivity and the line
width are also favorable.
PMID- 10670905
TI - From crystalline to glassy gallium fluoride materials: an NMR study of 69Ga and
71Ga quadrupolar nuclei.
AB - Owing to the implementation of acquisition techniques specific for nuclei with
very large quadrupolar interaction (full shifted echo and variable offset
cumulative spectra (VOCS)), NMR spectra of 69Ga and 71Ga are obtained in
crystallised (PbGaF5, Pb3Ga2F12, Pb9Ga2F24 and CsZnGaF6) and glassy (PbF2-ZnF2
GaF3) gallium fluorides. Simulations of both static (full echo or VOCS) and 15
kHz MAS spectra allow to obtain consistent determinations of isotropic chemical
shifts and very large quadrupolar parameters (nuQ up to 14 MHz). In the
crystalline compounds whose structures are unknown, the number and the local
symmetry of the different gallium sites are tentatively worked out. For the
glassy systems, a continuous Czjzek's distribution of the NMR quadrupolar
parameters accounts for the particular shape of the NMR spectrum.
PMID- 10670906
TI - Nicotinamide inhibits enhanced in vitro production of interleukin-12 and tumour
necrosis factor-alpha in peripheral whole blood of people at high risk of
developing type 1 diabetes and people with newly diagnosed type 1 diabetes.
AB - Macrophages and T lymphocytes are the first cells to appear in pancreatic islets
in the development of autoimmune diabetes. It has been suggested that cytokines
released by monocytes/macrophages, including interleukin-1beta (IL-1beta),
interleukin-12 (IL-12) and tumour necrosis factor-alpha (TNF-alpha) could have an
initial role in islet B-cell damage. The aim of the present study was to estimate
the effect of human insulin and nicotinamide on the levels of monocyte/
macrophage derived cytokines in the peripheral blood of humans at risk of Type 1
diabetes, and in patients with newly diagnosed Type 1 diabetes compared to
healthy control subjects. The study was carried out on three groups of subjects:
20 first degree relatives of people with Type 1 diabetes (with two or more
antibodies against pancreatic B-cell antigens); 22 patients with recent onset of
Type 1 diabetes (duration of the disease 3-6 months); and 25 age- and sex-matched
healthy subjects. Cytokine levels (IL-1beta, IL-12, and TNF-alpha) in the
supernatants of whole blood cultures incubated with PHA alone (10 microg/ml), or
PHA + human insulin (50 microg/ml), or PHA + nicotinamide (100 micromol/l) were
quantified by ELISA. In the cultures with nicotinamide the concentration of IL-12
and TNF-alpha was significantly lower in the prediabetic group, diabetic
patients, and the healthy controls than in the cultures with PHA only or with PHA
+ insulin. There were no significant differences in IL-1beta production in the
cultures after incubation with the different stimuli in the studied groups and
healthy controls. No significant influence of human insulin on
macrophage/monocyte cytokines secretion in in vitro cultures of the peripheral
blood was found. This suggests that nicotinamide could influence
monocyte/macrophage function in peripheral blood by inhibiting production of IL
12 and TNF-alpha.
PMID- 10670907
TI - Methods for assessing diabetic polyneuropathy: validity and reproducibility of
the measurement of sensory symptom severity and nerve function tests.
AB - The usefulness of sensory symptoms in the assessment of diabetic polyneuropathy
is unclear. In the present study, we studied the hypothesis that pain is
associated with small nerve fibre function, and that sensory alteration is
associated with large nerve fibre function. In addition, we assessed the
reproducibility and the ability to detect changes in clinical status over time of
the nerve function tests currently used in clinical trials. Patients (78) with
stable diabetic polyneuropathy were examined on three separate occasions with a
test-retest interval of 17 and 52 weeks. Small nerve fibre function was measured
using temperature discrimination thresholds for warmth (TDTwarmth) and cold
(TDTcold). Large nerve fibre function was measured by testing sensory and motor
nerve conduction velocities (SNCV and MNCV) and vibration perception thresholds
(VPT). Neuropathic pain was only significantly associated with TDTcold, and with
the MNCV of the tibial nerve. Sensory alteration was associated with almost all
nerve function tests except the SNCV and MNCV of the ulnar nerve. The
measurements of symptom severity and the nerve function tests all proved to be
sufficiently reproducible. The standardized smallest detectable difference on
group level (SDD) of the measurement of sensory alteration and neuropathic pain
were almost the same (9% and 12%, respectively). Among the nerve function tests,
the SNCV and MNCV had the smallest SDD (3-4%), and were, therefore, potentially
the most responsive instruments. The SDD of the TDT was greater than the VPT (9
14% vs 21-28%, respectively). In conclusion, neuropathic pain was not associated
with small nerve fibre function, and sensory alteration was associated with both
large and small fibre function. In addition, the standardized measurement of
symptom severity, the SNCV and MNCV tests, and the VPT test appear to be useful
for monitoring the course of polyneuropathy in clinical trials.
PMID- 10670908
TI - Delapril versus manidipine in hypertensive therapy to halt the type-2-diabetes
mellitus-associated nephropathy.
AB - Thirty-nine hypertensive patients with type 2 diabetes mellitus were followed
under long-term treatment (mean, 20.7 months) with manidipine hydrochloride, a Ca
antagonist, or delapril hydrochloride, an ACE inhibitor, at nine institutions.
Both the treatments showed similar antihypertensive effects, although slight but
significantly larger decreases were observed in systolic and mean blood pressures
at months 12 and 24 in the patients treated with manidipine (P < 0.02). The
urinary albumin excretion index (AEI) tended to increase throughout the study in
both treatment groups, but no significant difference in AEI was observed between
the two treatment groups at any time point. Overt albuminuria developed in four
patients on manidipine but did not appear in any of the patients on delapril. The
risk of progression to overt albuminuria was significantly different between
manidipine and delapril groups (P = 0.011). No increase in serum creatinine (Cr)
was observed with delapril. The average excretion indexes of tubular markers such
as beta2-microglobulin, alpha1-microglobulin, and NAG tended to be higher in the
patients on manidipine than in those on delapril. Taken in sum, these findings
suggest that the ACE inhibitor delapril is more beneficial than the Ca antagonist
manidipine in the treatment of diabetic renal diseases via mechanisms other than
the blood pressure regulation, partly through their different effects on tubular
function. In conclusion, delapril was significantly more effective than
manidipine in inhibiting progression to overt albuminuria in hypertensive type 2
diabetes mellitus patients.
PMID- 10670909
TI - Normal pressure hydrocephalus in diabetic patients with recurrent episodes of
hypoglycemic coma.
AB - The pathophysiology of brain damage induced by severe hypoglycemia is still
unknown. We experienced a case with type 1 diabetes and recurrent severe
hypoglycemic coma who showed a central brain atrophy and an abnormal
cerebrospinal fluid flow, suggesting normal pressure hydrocephalus. Following
this case, the CSF flow was studied using 111In-DTPA cisternography in six
consecutive diabetic patients admitted for repeated episodes of hypoglycemic
coma. All the patients showed the central brain atrophy on computed tomography
and four of them (67%) had the ventricular reflux, with delayed clearance of
111In-DTPA. Two patients with abnormal CSF flow showed cognitive dysfunction by
WAIS or WAIS-R. In contrast, none of five randomly selected diabetic patients,
without hypoglycemic coma showed abnormal CSF flow. Our results suggest the
presence of normal pressure hydrocephalus in diabetic patients with recurrent
hypoglycemic coma. It may associate with the cognitive dysfunction.
PMID- 10670910
TI - Out-patient management does not impair outcome of pregnancy in women with type 1
diabetes.
AB - In recent years, out-patient protocols have mainly displaced historical obstetric
management of diabetic pregnancy. The impact of the change from centralized in
patient to decentralized out-patient treatment on glycaemic control and its
effects on the outcome of newborns in diabetic pregnancies was therefore studied
using the population-based data on 296 pregnancies in 224 women with type 1
diabetes over 10 years (1986-1995) in the two northernmost provinces of Finland.
The area comprises one tertiary level and four other central hospitals. The
change of policy was effected in 1990 and to determine the impact of this change,
the study period was divided in two (period 1, 1986-1990, n = 135; period 2, 1991
1995, n = 161). At the first antenatal contact (mean 9.9 weeks of gestation) 73%
of women had unsatisfactory glycaemic control, but it improved rapidly with
pregnancy and was significantly better (P < 0.05) in the second study period. The
incidence of congenital malformations was somewhat greater (NS) in period 2 but
perinatal mortality did not change. Out-patient management does not impair
outcome in type 1 diabetic pregnancy.
PMID- 10670911
TI - Serum sialic acid in young type-1 diabetic patients.
AB - It is well established that serum total sialic acid (TSA) is elevated in patients
with type-2 diabetes mellitus (NIDDM) compared to non-diabetics. However, it is
not clear whether serum TSA is also elevated in type-1 diabetic patients (IDDM).
Twenty-one type-1 patients were studied along with age and sex matched normal non
diabetic subjects (ten males and 11 females). Their ages were 24.8+/-3.4 years
(20-30) and 23.5+/-3.9 years (18-30) respectively. The duration of diabetes
mellitus was 12.6+/-6.7 years (1-24) with a HBA1c of 9.0+/-2.2% (6.0-14.9). There
was no significant difference in serum TSA of the type-1 diabetic patients 689+/
107 mg/l versus 670+/-119 mg/l in the normal subjects. Nor was there a
significant correlation between serum TSA with patient age (r = -0.31), urine
albumin/creatinine ratio (ACR) (r = 0.25), HBA1c (r = 0.36), plasma random
glucose (r = -0.04) or diabetes duration (r = -0.09) in the diabetic patients.
However, there was a significant correlation between serum TSA and mean daily
insulin dose (r = 0.51, P<0.02) and also serum cholesterol and triglyceride (r =
0.58, P<0.01 and r = 0.49, P<0.04, respectively) in the type-1 diabetic patients.
In summary, we conclude that serum TSA is not elevated in young type-1 diabetic
patients compared with normal age and sex matched control subjects. However, the
relationship between serum TSA and serum lipids and also mean daily insulin dose
merits further research.
PMID- 10670912
TI - Painful diabetic polyneuropathy: epidemiology, pain description, and quality of
life.
AB - A prospective survey study was performed in patients with painful diabetic
polyneuropathy (PDN) to assess the nature and scope of their pain. Pain
associated with diabetic neuropathy is commonly encountered in clinical practice.
Yet, little is known regarding the pain experience and impact on quality of life
in persons with painful diabetic neuropathy. These 105 patients noted an average
of 6/10 pain, most often described as 'burning', 'electric', 'sharp', and
'dull/ache', which, for most, is worse at night time and when tired or stressed.
On average, patients reported that the pain caused substantial interference in
sleep and enjoyment of life and moderate interference in recreational activities,
normal work, mobility, general activity, social activities, and mood.
Unexpectedly, a potential genetic predisposition to the development of painful
neuropathy was suggested by the fact that a majority (56%) reported a family
member with PDN. Thus, this study found that pain associated with diabetic
neuropathy is a significant medical issue that has a substantial impact on the
quality of life of many people with this condition.
PMID- 10670913
TI - Limitations of glycosylated haemoglobin as an index of glucose intolerance.
AB - This study was conducted (a) to establish a normal cut-off value for glycosylated
haemoglobin measured as HbA1c in South Indian subjects, and (b) to evaluate its
usefulness in demarcating different categories of glucose intolerance. HbA1c
measurement was carried out in 1261 cases with no known history of diabetes,
while being tested by oral glucose tolerance test (M:F 850:411, mean age 40+/-12
years). An immunoturbidimetric procedure for HbA1c assay (Tina-Quant, Boehringer
Mannheim, Germany) was used. The specificity and sensitivity of HbA1c in
demarcating normal glucose tolerance (NGT) from abnormal tolerance were
calculated using the ROC procedure. By the ROC analysis, a cut-off value of HbA1c
> or = 6.0% gave a sensitivity of 88.5% and specificity of 62.8% using the WHO
criteria (2-h plasma glucose > or = 200 mg/dl). Using the ADA criterion (fasting
plasma glucose > 125 mg/dl) the sensitivity and specificity for the same cut-off
value were 85.2 and 61.2%. In NGT, only a small percentage of the variance in
HbA1c was explained by the fasting plasma glucose (FPG) values. The overall
correlation coefficient between the fasting plasma glucose and HbA1c was r = 0.8,
r2 = 0.64 and, in the case of 2-h post glucose, r = 0.82, r2 = 0.67. This showed
that more than 35% of the variations in HbA1c were not explained by the plasma
glucose values. The study showed that HbA1c values of > or = 6.0% gave a
reasonably high sensitivity and specificity for diagnosis using the WHO or ADA
criteria. However, nearly 35% of the variations in HbA1c were not explained by
the variations in plasma glucose. Wide inter-individual variations even in the
normoglycaemic range make the test unsuitable for diagnostic purpose.
PMID- 10670914
TI - Prevalence of type 2 diabetes mellitus and impaired glucose tolerance in the
Kashmir Valley of the Indian subcontinent.
AB - This cross-sectional population survey was undertaken to determine the prevalence
of type 2 diabetes and impaired glucose tolerance in subjects aged 40 years or
more in Kashmir Valley, India. The study was carried out in two phases. In phase
one, 6091 randomly selected subjects, 40 years or older, from all six districts
of the valley were surveyed for prevalence of known diabetes mellitus. In phase
two, 5083 subjects, 40 years or older, were screened with oral glucose tolerance
test for prevalence of undiagnosed (asymptomatic) diabetes mellitus and impaired
glucose tolerance. Abnormalities of carbohydrate intolerance were determined as
recommended by WHO. Of 6091 subjects interviewed, 115 were known cases of
diabetes mellitus with an overall prevalence of 1.89% (1.98% in males and 1.77%
in females). Results of glucose tolerance test revealed that mean fasting as well
as mean 2 h blood glucose was significantly more in females as compared to males
(4.68+/-0.91 and 6.40+/-2.12 vs. 4.49+/-0.96 and 5.94+/-2.03 mmol/l,
respectively, P < 0.0001). Of 5083 subjects who were subjected to glucose
tolerance test (GTT), 627 (12.34%) had an abnormal test; with 411 (8.09%) having
impaired glucose tolerance (IGT) and 216 (4.25%) having diabetes mellitus. The
prevalence of IGT as well as of diabetes was significantly more in females as
compared to males (P < 0.001). Subjects who had family history of diabetes had a
significantly higher prevalence of abnormal GTT. Prevalence of known diabetes as
well as that of abnormal GTT steadily increased with age, with a highest
prevalence in the age group of > or = 70 years (P < 0.001). Obese subjects had a
significantly higher basal as well as 2 h blood glucose in males as well as in
females. Subjects with diabetes on GTT had a higher waist/hip ratio. Overall the
prevalence of diabetes as well as IGT was significantly higher in the urban
population. We conclude that 1.89% of the general population have known diabetes,
4.25% have undiagnosed diabetes and 8.09% have impaired glucose tolerance test;
making the total load of abnormal glucose tolerance 14.23% in Kashmir Valley. In
subjects greater than 40 years of age having a family history of diabetes,
obesity, higher age (50 years or above), female sex, and urban origin have more
chance (odds ratio: 4.65, 2.30, 1.87, 1.49 and 1.16, respectively) of developing
abnormal glucose tolerance.
PMID- 10670915
TI - No difference in serum sialic acid in type 2 diabetic patients from the United
Arab Emirates with and without diabetic retinopathy.
AB - Serum total sialic acid (TSA) has recently been shown to be related to diabetic
retinopathy. However, there is some controversy as this may be true in European
Type 2 diabetic patients but not South Asians. There are few data looking at
serum TSA expression in Arab Type 2 diabetic patients from the United Arab
Emirates (UAE) and we wished to test the hypothesis that there may be different
serum TSA expression in Arab Type 2 diabetic patients as regard to retinopathy.
Sixty-five Type 2 diabetic patients from the UAE were studied (19 male and 46
female, age 57.5+/-9.8 (45-74) years, duration of diabetes 9.4+/-5.7 (0-22)
years. The serum TSA in 13 patients with diabetic retinopathy was 757+/-130 mg/l
and 782+/-163 mg/l in those without retinopathy (NS). There was no significant
correlation between serum TSA and patient age, serum fructosamine, diabetes
duration, or blood pressure. As in South Asians serum TSA does not appear to be
elevated in Type 2 diabetic patients from the United Arab Emirates with diabetic
retinopathy.
PMID- 10670916
TI - On the radioanalytical methods used to assay stainless-steel-encapsulated,
ceramic-based 90Sr-90Y intravascular brachytherapy sources.
AB - Very quantitative radiochemical procedures for the destructive assay of stainless
steel-encapsulated, ceramic-based 90Sr-90Y intravascular brachytherapy sources
(termed 'seeds') have been devised. These seeds, developed and provided by Bebig
Isotopentechnic und Umweltdiagnostik (Berlin, Germany) in collaboration with the
Novoste Corporation (Norcross, GA), are intended for use in the prophylactic
treatment of restenosis following balloon angioplasty in heart-disease patients.
The procedures were applied to the radionuclidic assay of both the bare-ceramic
source materials (of proprietary composition) contained within the seeds and to
the stainless-steel (SS) sealed sources. The approach consisted of extracting
some arbitrary fraction of the 90Sr activity from the ceramic-like material and
assaying the resulting solution by 4pi beta liquid scintillation (LS)
spectrometry with 3H-standard efficiency tracing. The fraction of extracted
activity was determined by ionization current measurements before and after the
chemical extraction. All of the ionization current and LS-based activity
determinations were made under the experimentally-verified conditional that 90Y
was in radioactive equilibrium with 90Sr. For the assay of the SS-jacketed seeds,
the encapsulation was initially dissolved and the resultant solution was also
assayed by LS spectrometry to determine the amount of activity removed by the SS
dissolution step. The developed protocol included provisions for accounting for
all possible losses of 90Sr activity in the chemical and source-handling
procedures, for the unrecovered activity in the extracted source material and for
any residual activity in the solution-transfer and source-handling tools. These
destructive assays were required for relating radiochromic-fill measurements of
the absorbed dose spatial distributions for the seeds to theoretic dose modelling
and for establishing calibration factors for subsequent non-destructive
radionuclidic measurements on the seeds.
PMID- 10670917
TI - Separation of 111Ag from neutron irradiated natural palladium using alumina as an
adsorbent.
AB - A simple method is presented for the separation of no-carrier-added 111Ag from
neutron irradiated natural palladium. The method is based on sorption of 111Ag in
0.01 M HCl on alumina. Palladium is removed by washing with 0.1 M HCl and the
111Ag is eluted with 4 M HCl. The overall yields of 111Ag are better than 85%
with < 1 microg/ml palladium as an impurity. The whole procedure from dissolving
the target to the final 111Ag solution takes about 2 h.
PMID- 10670918
TI - Evaluation of the contribution of smoking to total blood polonium-210 in Saudi
population.
AB - A preliminary study of 210Po concentrations in the blood of some smokers and
nonsmokers is presented in order to evaluate the contribution of smoking to total
blood 210Po in Saudi population. Blood samples were collected from 30 volunteers
and analyzed by high resolution alpha-spectrometry using a radiochemical
technique. The technique is based on the separation of polonium from other
components of the sample by wet ashing with an HNO3/H2O2 oxidizing mixture and
spontaneous deposition on a silver disc under the relevant conditions for alpha
particle counting. The results indicated that a significant fraction (about 30%)
of blood 210Po is related to smoking.
PMID- 10670919
TI - Cleaning of liquid radioactive wastes using natural zeolites.
AB - Natural zeolite, clinoptilolite, was used to eliminate liquid radioactive wastes
(LRW) 137Cs and 90Sr. The influence of several factors (pH of solution, grain
size of the zeolite, etc.) on the process effectivity was studied. It was shown
that clinoptilolite is an effective filter of the nuclides above.
PMID- 10670920
TI - Potential of rice husks for antimony removal.
AB - The adsorption behavior of rice husks for antimony ions from aqueous solutions
has been investigated as a function of appropriate electrolyte, equilibration
time, hydrogen ions, amount of adsorbent, concentration of adsorbate, effect of
diverse ions and temperature. The best conditions in which this material can be
used as adsorbent have been explored. The radiotracer technique was employed to
determine the distribution of antimony (122Sb) using a batch method. Maximum
adsorption was observed at 0.01 mol L(-1) acid solutions (HNO3, HCl, H2SO4 and
HClO4) using 1.0 g of adsorbent for 1.92 x 10(-5) mol L(-1) antimony
concentration in 10 min equilibration time. Studies show that the adsorption
decreases with the increase in the concentrations of all the acids. The
adsorption data follow the Freundlich isotherm over the range of 1.92 x 10(-5) to
2.05 x 10(-4) mol L(-1) antimony concentration. The characteristic Freundlich
constants i.e., 1/n = 0.82 +/- 0.05 and K = 4.61 +/- 0.07 m mol g(-1) have been
computed for the sorption system. The uptake of antimony increases with the rise
in temperature (299-323 K). Thermodynamic quantities i.e., deltaG0, deltaS0 and
deltaH0 have also been calculated for the system. The sorption process was found
to be endothermic.
PMID- 10670921
TI - Investigation of defects in high-energy heavy ion implanted GaAs.
AB - Undoped semi-insulating GaAs were implanted with 500 MeV Ne ions. Monte Carlo
simulation revealed that the largest concentration of vacancies induced was
around the end of the Ne ion range. Positron Annihilation measurement showed that
after lower dose implantation, divacancies were formed, which coexisted with
monovacancies. On increasing the dose, all the monovacancies changed to
divacancies. The temperature dependence of positron lifetime suggested the
existence of negatively charged antisites GaAs. Near infra-red spectra were also
measured to study the implantation induced amorphous layers.
PMID- 10670922
TI - Attenuation of fission neutrons by some hydrogeneous shield materials and the
exponential dependence of the attenuated total neutron dose rate on the shield
thickness.
AB - This work deals with the attenuation of fission neutrons by some hydrogeneous
shield materials. The attenuated fission neutrons are described by the energy
groups (fast, epithermal and thermal). The exponential decrease in the fast flux
is represented by the removal cross section concept. Each of the epithermal and
thermal fluxes is expressed using the diffusion equation including a pair of
arbitrary constants to be determined using the corresponding boundary conditions.
The solution obtained for the required arbitrary constants is then approximated
in a simplified form such that it may easily replace the corresponding exact
solution. The attenuation values, by which the neutron dose rate distributions
are exponentially decreased through certain thicknesses are also determined for
the given materials. They are compared to the corresponding experimental and
theoretical data. The results obtained for the total neutron dose rate
distributions in terms of a suitable range of layer thicknesses are then used to
determine--for each material--an average value for the total neutron dose rate
representing the exponential decrease during passage through the considered range
of layer thicknesses.
PMID- 10670923
TI - Synthesis of [18F]fluoromethyl iodide, a synthetic precursor for
fluoromethylation of radiopharmaceuticals.
AB - [18F]fluoroiodomethane was labeled via nucleophilic substitution of diiodomethane
with [18F]fluoride, and labeling conditions were optimized. The optimized
labeling yield was 40 +/- 8% (decay-corrected). The synthesis and purification of
[18F]fluoroiodomethane took 15 min. The reactions of [18F]fluoroiodomethane with
amine, carboxylic acid, thiol and phenoxide groups produced fluoromethylated
derivatives with various yields (12-95%). The results indicated that
[18F]fluoroiodomethane is a valuable synthetic precursor for the introduction of
an [18F]fluoromethyl group into radiopharmaceuticals.
PMID- 10670924
TI - Preparation and biodistribution of rhenium-188 labeled albumin microspheres B 20:
a promising new agent for radiotherapy.
AB - Intra-arterial infusion of labeled particles is an effective method for
endoradiotherapy of tumors. In this study, we radiolabeled biodegradable HSA
microspheres (mean diameter = 25 microm) with the short-lived beta-emitter 188Re
available from the aluminia-based 188W/188Re generator system. After 1 h 35-40%
of the relative large amount of Sn(II) chloride required for effective reduction
of Re(VII) for efficient attachment to the particles is precipitated as an
amorphous coat of tin hydroxid colloid on the particle surface. The final 188Re
bound to the particles was found to be stable in vitro. The radiolabelling yield
was > 90%. The biological half-life was > 250 h and demonstrated sufficient in
vivo stability after i.v. injection in Wistar rats. Because of the attractive
properties of 188Re and the uniform particle size and stability, in vivo, this
new agent is an attractive candidate for endoradiotherapy of tumors after
selective catheterization.
PMID- 10670925
TI - Syntheses and radiolabeling of cysteine-oximes and pharmacological behaviour of
their 99mTc complexes.
AB - Synthesis of two novel ligands using 2-oximino-butan-3-one and L-ethyl cysteinate
is described. The synthetic procedure involved the formation of Schiffs base by
the condensation of the amino group of L-ethyl cysteinate with the carbonyl group
of 2-oximino-butan-3-one to provide the ligand I, N'(butan-2-enyl-3-oximino)ethyl
cysteinate, followed by reduction of the Schiffs base with sodium borohydride to
ligand II, N'(3-oximinobutyl)ethyl cysteinate. The ligands were characterised by
NMR spectroscopy. Complexation studies with 99mTc were carried out using stannous
tartrate as the reducing agent. The complexes were characterised by paper
chromatography, thin layer chromatography and paper electrophoresis techniques.
The complexes are formed in high yields when the reactions were carried out at pH
7-9. The 99mTc complex with ligand I is formed instantaneously while the 99mTc
complex with ligand II is formed at a slower rate. The complexes were found to be
neutral but the lipophilicity of the complex with ligand I was higher than that
of the complex of ligand II. The stability of the complex with ligand I was
relatively poor as compared to that of the complex with ligand II.
Biodistribution studies of the 99mTc complexes of ligand I and II showed rapid
blood clearance with hepatobiliary uptake. Renal excretion of the complex of
ligand II was more than that observed for the complex of ligand I. The complexes
did not show significant uptake in brain in spite of their favourable properties
such as neutrality, lipophilicity and structural similarity with both ECD and
HMPAO.
PMID- 10670926
TI - In-target production of high specific radioactivity [15O]nitrous oxide by
deuteron irradiation of nitrogen gas.
AB - A simple and rapid production method for high specific radioactivity [15O]N2O has
been developed based on the 14N(d,n)15O reaction on high-purity nitrogen gas in a
flow-through target irradiated with a 0.5 microA beam of 7 MeV deuterons. The
[15O]N2O formed during irradiation is selectively concentrated from the target
effluent by adsorption on a zeolite during 150 s and subsequently released by
rapid heating into a pulse with a full width at half maximum of 3.5 s. The
radioactivity and specific radioactivity in the pulse amount to 4 MBq [15O]N2O
and 4.5 x 10(13) Bq/mol respectively with a radiochemical purity >99.95%. A
tenfold higher specific radioactivity may be feasible at larger beam currents. It
was shown that stable N2O was also formed during irradiation. Based on responses
to variations in various parameters during irradiation and on analyses performed
on the products, an explanation is given on the mechanisms of in-target [15O]N2O
and N2O formation, involving reaction of a particular excited state of O3 with
N2.
PMID- 10670927
TI - A new, convenient method for the preparation of 4-[18F]fluorobenzyl halides.
AB - A convenient method suitable for automated preparation of 4-[18F]fluorobenzyl
halides from no-carrier-added [18F]fluoride has been developed. 4
[18F]Fluorobenzaldehyde, synthesized from [18F]fluoride by aromatic nucleophilic
substitution on 4-trimethylammoniumbenzaldehyde triflate, was first retained on a
C18 cartridge and there efficiently reduced to 4-[18F]fluorobenzyl alcohol simply
by flowing an aqueous solution of NaBH4. The conversion of 4-[18F]fluorobenzyl
alcohol to 4-[18F]fluorobenzyl halide was investigated using PBr3, PI3, P2I4,
Ph3PBr2 and Ph3PI2 in CH2Cl2. 4-[18F]Fluorobenzyl halides were purified by
passing through a disposable silica cartridge. The conversion rapidly proceeded
in radiochemical yields of nearly 90% at 40 degrees C with P2I4 and almost
quantitatively at room temperature with Ph3PBr2. With this last reagent 4
[18F]fluorobenzyl bromide was obtained in overall radiochemical yields of 50-60%
within 30 min from EOB.
PMID- 10670928
TI - Investigations on thermal neutron reflection by activation method.
AB - The prompt neutron detection and the foil activation methods were compared for
the determination of the reflection cross-section of thermal neutrons and the
hydrogen content of bulk samples. The advantages and limitations of the two
methods are discussed.
PMID- 10670929
TI - Effect of lithium co-dopant on the thermoluminescence response of some phosphors.
AB - The effect of lithium co-dopant on the thermoluminescence of some TL phosphors
has been studied. These results show that lithium co-dopant when present in
CaSO4:Dy, CaSO4,Tm, CaF2:Mn, MgB4O7:Dy, MgB4O7:Tm, MgB4O7:Tb, MgB4O7:Mn,
CaB4O7:Dy and CaB4O7:Tm thermoluminescent phosphors induces higher luminescence
efficiency either due to better incorporation of activator ions or due to
improvement in energy transfer processes. Co-doping with Li of the above given
phosphors resulted in increasing the TL sensitivity from 1.2 to 3.4 times, when
compared with that of the TL phosphors without lithium co-dopant. The effect of
co-doping with lithium impurities on the thermoluminescence of various TL
phosphors is also studied in dependence of Li concentration, of the chemical form
of added lithium compounds and of the method of addition of Li co-dopant during
the TL phosphor preparation. It is observed that the addition of Li co-dopant
induces in some TL phosphors enhancement of the lower temperature peak which is
correlated with the increase of TL sensitivity. The high TL output of these TL
phosphors could be used in dosimetric practice for special short-term
measurements.
PMID- 10670930
TI - An iterative approach for TRIGA fuel burn-up determination using nondestructive
gamma-ray spectrometry.
AB - The purpose of this work is to establish a method for evaluating the burn-up
values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the
short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history
is not needed in this method. Short-lived fission-product activities were
established by reirradiating the spent fuels in a nuclear reactor. Based on the
measured activities, 235U burn-up values can be deduced by iterative
calculations. The complication caused by 239Pu production and fission is also
discussed in detail. The burn-up values obtained by this method are in good
agreement with those deduced from the conventional method based on long-lived
fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio.
PMID- 10670931
TI - Assessing the information content of phosphor produced medical images:
application to Zn2SiO4:Mn phosphor.
AB - In this study a method to assess the information content of medical images
produced by phosphors is described. The optical signal emitted by the phosphor
after X-ray excitation, the detective quantum efficiency (DQE), expressing the
signal-to-noise ratio (SNR) transfer efficiency, and the information capacity
were experimentally determined. The method was based on light flux and modulation
transfer function (MTF) measurements and was used to assess the imaging
performance of the Zn2SiO4:Mn phosphor. The latter was employed in the form of
laboratory prepared phosphor layers (test screens). Results showed that high
values for optical signal emission and DQE were obtained for medium thickness
phosphor layers (56 and 89 mg/cm2) at 20 kVp X-ray tube voltage. The information
capacity was found to decrease continuously with phosphor coating weight.
PMID- 10670932
TI - Borehole parametric study for neutron induced capture gamma-ray spectrometry
using the MCNP code.
AB - The MCNP Monte Carlo code has been used to simulate neutron transport from an Am
Be source into a granite formation surrounding a borehole. The effects of the
moisture and the neutron poison on the thermal neutron flux distribution and the
capture by the absorbing elements has been calculated. Thermal and nonthermal
captures for certain absorbers having resonance structures in the epithermal and
fast energy regions such as W and Si were performed. It is shown that for those
absorbers having large resonances in the epithermal regions when they are present
in dry formation or when accompanied by neutron poisons the resonance captures
may be significant compared to the thermal captures.
PMID- 10670933
TI - Indoor radon/thoron survey report from Hamirpur and Una districts, Himachal
Pradesh, India.
AB - A survey of indoor radon and thoron levels has been carried out in a number of
villages in the vicinity of uranium bearing sites in the Hamirpur and Una
districts of Himachal Pradesh (H.P.), India. Levels were analysed with reference
to the nature of building material, soil type and different seasons of the year.
The one year average for radon concentration was found to vary from a minimum of
19.7 to a maximum of 146.3 Bq/m3 while the minimum and maximum thoron
concentrations were 9.1 and 70.7 Bq/m3, respectively. The dose rate varied from
0.1 to 8.67 microSv/h. These are discussed in the light of ICRP recommendations.
PMID- 10670934
TI - Instrumental neutron activation analysis of rocks from Cayajabos petroleum ore.
AB - The relative INAA method under statistical control was used to measure the
concentrations of Sb, La, Eu, Co, Rb, Tb, Cs, Hf, Th, Cr, Lu, Yb, Ce, Sm, Gd, Nd.
Rare earth element (REE) Chondrite-normalized patterns are presented. The
La(cond)/Lu(cond) normalized concentration ratios obtained confirm the
carbonaceous character of the rocks.
PMID- 10670935
TI - Comparison between different types of glass and aluminum as containers for
irradiation samples by neutron activation analysis.
AB - Three different types of glass and four different kinds of aluminum sheet have
been analyzed using neutron activation analysis. The irradiation facilities of
the first Egyptian research reactor (ET-RR-1) and a hyper-pure germanium (HPGe)
detection system were used for the analysis. Among the 34 identified elements,
the isotopes 60Co, 65Zn, 110mAg, 123mTe, 134Cs, 152Eu and 182Ta are of special
significance because of their long half-lives, providing a background
interference for analyzed samples. A comparison between the different types of
containers was made to select the preferred one for sample irradiation.
PMID- 10670936
TI - Studies on microencapsulation of 5-fluorouracil with poly(ortho ester) polymers.
AB - Microencapsulation of 5-fluorouracil was successfully accomplished with
poly(ortho ester) polymers by the emulsification-solvent evaporation method.
While actual drug loading increased with increasing drug load (5-15% w/w), the
entrapment efficiency remained essentially unaffected, under a given set of
experimental conditions. Incorporation of sorbitan sesquioleate enhanced
entrapment efficiency, decreased the volume-surface mean diameter of the
poly(ortho ester) microspheres and provided controlled release of 5-fluorouracil.
The volume of the aqueous phase was more important than the concentration of
polyvinyl alcohol in it. The entrapment efficiency improved from 13 to 33% when
the volume of the aqueous phase was increased from 20 to 80 ml. The volume of
organic phase (methylene chloride) and the concentration of polymer in it played
an important role. The use of smaller volumes of more concentrated polymer
solution enhanced actual drug loading, entrapment efficiency and produced larger
microspheres. The release studies conducted in 0.01 M phosphate buffer at 37+/
1.0 degrees C demonstrated that the release of 5-FU from the microspheres
prepared with sorbitan sequioleate was nearly independent of the initial drug
load with a mean zero-order rate constant of 0.0063% per hour. The data suggested
that drug release was largely a diffusional process with contributions from
dissolution and polymer degradation.
PMID- 10670937
TI - In vitro delivery of a sparingly water soluble compound from PLA50
microparticles.
AB - The administration of a sparingly soluble drug is always problematic, especially
when the drug has to be released from the degradable matrix of a polymeric drug
delivery system. Attempts were made to achieve the complete release of 1-[2
(fluorobenzoyl) aminoethyl]-4-(7-methoxynaphtyl)piperazine (FAMP), a potential
anxiolytic and antidepressor hydrophobic compound, from racemic poly(lactic acid)
(PLA50)-based microparticles, 100% release was required at a low rate in order to
allow monthly repeated S.C. or I.M. injections of this potent compound. FAMP
polymer combinations were made in the form of microspheres by the solvent
evaporation technique. Release profiles were investigated under dynamic
conditions by using a constant flow rate of pH 7.4 0.15 M phosphate buffer, used
as a model of body fluids. Under these conditions, none of the microsphere
compositions led to total release within a month, even when hydrophilic
excipients, namely fructose and PEG were added. PLA50-FAMP microparticles with
compositions and sizes similar to those of the microspheres, were then made by
direct blending in dichloromethane, evaporation of the solvent, grinding and
sieving. These formulations also failed in providing total drug release within 30
days, even at a high drug load. FAMP/PLA50/water-soluble additive, ternary
grounded particles were finally prepared with fructose, PLA50 oligomers or
poly(ethylene glycol) (PEG) as the additive. Only PLA50 grounded particles with
percolating FAMP-PEG microdomains allowed 100% release of FAMP over a 30 day
period, at a quasi constant rate which depended primarily on solubility and
channelling provided the flow was slow enough. Data are discussed in terms of the
accessibility of the entrapped drug to the aqueous medium.
PMID- 10670938
TI - Preparation and some properties of water-insoluble, whey protein-based
microcapsules.
AB - A method, consisting of double emulsification and chemical cross-linking with
glutaraldehyde was used to prepare whey protein-based microcapsules containing
anhydrous milk fat as a model core. Effects of emulsion composition and pH on
core retention, microstructure, and water-solubility of microcapsules were
investigated. In all cases, core retention higher than 88% was accomplished and,
in most cases, was not significantly affected by emulsion composition. In all
cases, spherical microcapsules, 10-80 microm in diameter, were obtained. Outer
topography and the inner structure of microcapsules were significantly affected
by the pH of the emulsion. In all cases, microcapsules were practically water
insoluble. Microcapsules similar to the developed prototype may be suitable for
controlled core release in application fields where chemical cross-linking is
acceptable.
PMID- 10670939
TI - Poly(vinylbenzyl chloride) microsphere synthesis and their chemical
modifications.
AB - Vinylbenzyl chloride (VBC) was dispersion polymerized to give monodisperse
microspheres in the presence of poly(vinylpyrrolidone) (PVP) as a steric
stabilizer. The effect of PVP concentration on the size and on microsphere
stability during the polymerization process was investigated. Microsphere size
was examined when co-stabilizer molecules were employed with PVP during the
polymerization reaction. The built-in reactive chloromethyl groups of the
microspheres were the sites of the nucleophilic reaction of two amino-group model
molecules, glucosamine (G), a hexosamine implicated in processes of molecular
recognition, and also bovine serum albumin (BSA). Elemental analyses and Fourier
transform infrared spectroscopy (FTIR) spectra showed that poly(vinylpyrrolidone)
was associated with the microsphere network. Elemental analyses, attenuated total
reflection infrared spectroscopy (ATR-FTIR), and zeta potential measurements
confirmed G and BSA links at the microsphere surface.
PMID- 10670940
TI - Studies on the in vitro release characteristics of ibuprofen-loaded polystyrene
microparticles.
AB - Ibuprofen-loaded polystyrene microparticles were prepared by the emulsion-solvent
evaporation process from an aqueous system. The effects of different parameters
on the drug content and on the release of the drug from the microparticles were
investigated. The drug content, in all the formulations, was less than the
theoretical drug loading. The lower drug content was due to drug partitioning to
the external aqueous phase during formulation. Statistical analysis revealed that
the variation in the concentrations of the emulsion stabilizer and the organic
disperse phase volume did not significantly alter the release of the drug.
Although an increase in drug loading increased drug release from the
microparticles, a biphasic linear relationship was observed between the time
required for 50% drug release and the drug loading. The effect of size of the
microparticles on drug release was more important for the low drug-loaded
microparticles than that for the high drug-loaded microparticles. Such release
behaviour from the microparticles was explained on the basis of the morphological
structure of the microparticles.
PMID- 10670941
TI - Long-term stability of PBCA nanoparticle suspensions.
AB - In this study, the stability of poly(butyl cyanoacrylate) (PBCA) nanoparticle
suspensions was examined for up to 1 year by measuring the nanoparticle sizes.
The nanoparticles were prepared with different stabilizers (dextran 70.000,
poloxamer 188, or polysorbate 85), and the particle size was determined before
and after purification by centrifugation and after dilution with different
solutions (0.1 N HCl, 0.01 N HCl, H2O, and PBS). The most constant sizes were
with the untreated acidic nanoparticle suspensions. In all other cases,
agglomeration of the particles occurred: the extent of this agglomeration and the
time at which the agglomeration occurred depended on the experimental conditions.
Nanoparticle polymer degradation, as indicated by size decrease, was not
observed. Thus, PBCA nanoparticles can be stored as suspensions, making the
lyophilization and the sometimes problematic resuspension by ultrasonication,
unnecessary, which is advantageous for clinical applications.
PMID- 10670942
TI - The use of additives to modulate the release of a sparingly water soluble drug
entrapped in PLA50 microparticles.
AB - One of the major problems raised by the microencapsulation of drugs which are
sparingly soluble in water is the difficulty to achieve a controlled and total
release of the drug. It was previously shown that the microencapsulation of a
model water insoluble drug, namely 1-[2-(4-fluorobenzoyl)aminoethyl]-4-(7
methoxynaphthyl) piperazine hydrochloride (FAMP) with a hydrophilic additive like
low molar mass poly(ethylene glycol)s (PEG) can fulfil these requirements,
provided all the drug + additive matter is in contact with the surrounding liquid
medium via open pores and percolating channels. In this paper, PEG was replaced
by other additives, selected because of their potential ability to increase the
solubility of FAMP in pH = 7.4 isosomolar phosphate buffer (PBS). The idea was
that increasing the solubility locally in microparticles could allow the drug to
be released, despite its poor solubility in aqueous media like body fluids, and
be absorbed before recrystallization. The solubility in PBS of FAMP mixed with
additive, in the form of solid dispersions, was determined for various additives,
namely citric acid, dimyristoyl DL-alpha-phosphatidyl choline (DMPC), poloxamer
copolymers of different compositions and poly(dodecyl L-lysine citramidate)
(PLCAC12(100)), an aggregate-forming hydrophilic polyelectrolyte containing 100%,
hydrophobizing ester groups which can accommodate lipophilic compounds in
hydrophobic pockets present in the aggregates. PEG was taken as a reference. It
was found that DMPC, some poloxamers and the hydrophobized polyelectrolyte do
increase the solubility of FAMP in PBS. Investigation was made of the release of
FAMP from ground microparticles, whose loads were composed of FAMP combined with
these solubilization-promoting additives. It was found that the release rate of
FAMP from such systems can be increased and modulated to achieve an in vitro
sustained release over a 20-30 day period and secure exhaustion of the particles
at the end of this period.
PMID- 10670943
TI - The use of additives to modulate the release of a sparingly water soluble drug
entrapped in PLA50 microparticles: in vivo investigation.
AB - Sustained and total release of the sparingly water soluble compound, namely 1-[2
(4-fluorobenzoyl)aminoethyl]-4-(7-methoxynaphthyl) piperazine hydrochloride
(FAM), from poly (DL-lactic acid) (PLA50) microparticles was previously shown to
be feasible if the particles are obtained by grinding a solid mixture composed of
the polymer and a percolating array of the compound mixed with an additive. Such
microparticles, where the additive was poly (ethylene glycol) (PEG),
dimyristoylphosphatidylcholine (DMPC), or Poloxamer 6800, were administrated
subcutaneously to rats either as depot or using a liquid vehicle. The variations
of the plasma concentration vs time determined by high pressure liquid
chromatography and fluorometric detection, were plotted for the various
microparticle systems, blood being taken twice from each animal and each
measurement being triplicated. Data were analysed by non-compartmental analysis,
in order to evaluate the elimination constant, the half-life, the area under the
curve and the bioavailability for each system. Kinetics experiments were
performed over 24h and also for 7 days. It was found that, for the selected
formulations, the release of the sparingly water soluble compound depends on the
dissolution rate in vivo and on the physicochemical characteristics of the
additive, including solubility and micelle formation. Data correlated well with
the results of previous in vitro investigation.
PMID- 10670944
TI - Preparation of microcapsules for skin allergy testing by the solvent evaporation
process.
AB - Polyurethanes and polyvinyl alcohol modified by stearyl isocyanate are used as a
matrix for microparticles made by a solvent evaporation process to encapsulate
allergenic molecules, with petrolatum used as a neutral vehicle. The
encapsulation yields, depending on the agent to be encapsulated, vary from 22 to
45%.
PMID- 10670945
TI - Pea chloroplast carnitine acetyltransferase.
AB - The purpose of this study was to resolve the controversy as to whether or not
chloroplasts possess the enzyme carnitine acetyltransferase (CAT) and whether the
activity of this enzyme is sufficient to support previously reported rates of
fatty acid synthesis from acetylcarnitine. CAT catalyses the freely reversible
reaction: carnitine + short-chain acylCoA <--> short-chain acylcarnitine + CoASH.
CAT activity was detected in thc chloroplasts of Pisum sativum L. With membrane
impermeable acetyl CoA as a substrate. activity was only detected in ruptured
chloroplasts and not with intact chloroplasts, indicating that the enzyme was
located on the stromal side of the envelope. In crude preparations, CAT could
only be detected using a sensitive radioenzymatic assay due to competing
reactions from other enzymes using acetyl CoA and large amounts of ultraviolet
absorbing materials. After partial purification of the enzyme, CAT was detected
in both the forward and reverse directions using spectrophotometric assays. Rates
of 100 nmol of product formed per minute per milligram of protein were obtained,
which is sufficient to support reported fatty acid synthesis rates from
acetylcarnitine. Chloroplastic CAT showed optimal activity at pH 8.5 and had a
high substrate specificity, handling C2-C4 acyl CoAs only. We believe that CAT
has been satisfactorily demonstrated in pea chloroplasts.
PMID- 10670946
TI - Cirri of the stalked crinoid Metacrinus rotundus: neural elements and the effect
of cholinergic agonists on mechanical properties.
AB - Sea lilies are enigmatic animals due to their scarcity and their biology is
comparatively neglected. Cirri, arranged in whorls of five along the sea lily
stalk, anchor and support the animal. They consist of ossicles interconnected by
collagenous ligaments and by a central canal. Cirri have a well-developed nervous
system but lack muscular cells. A light and electron microscopic study was
performed to clarify the morphology of the nervous system of the cirri. Two
cellular networks were found, one of neuron-like cells and one of cells filled
with bullet-shaped organelles. Both networks ramify throughout the cirral
ossicles up to the interossicle ligaments. Mechanical tests were performed to
analyse the influence of cholinergic agonists on the mechanical properties of
these ligaments. In the tests, the cirral ligaments softened after the
application of acetylcholine, muscarinic agonists and nicotinic agonists. The
reaction time to muscarinic agonists was much slower than to acetylcholine and
nicotinic agonists. At low concentrations, muscarinic agonists caused active
development of force. No reaction to stimuli was observed in anaesthetized cirri.
The data clearly establish the existence of catch connective tissue which can
change its mechanical properties under nervous control mediated via nerves with
cholinergic receptors. The possible sources of the observed force production are
discussed and it is concluded that active contraction of collagenous ligaments
causes movement of cirri.
PMID- 10670947
TI - Coalition formation in animals and the nature of winner and loser effects.
AB - Coalition formation has been documented in a diverse array of taxa, yet there has
been little formal analysis of polyadic interactions such as coalitions. Here, we
develop an optimality model which examines the role of winner and loser effects
in shaping coalition formation. We demonstrate that the predicted patterns of
alliances are strongly dependent on the way in which winner and loser effects
change with contestant strength. When winner and loser effects decrease with the
resource-holding power (RHP) of the combatants, coalitions will be favoured
between the strongest members of a group, but not between the weakest. If, in
contrast, winner and loser effects increase with RHP, exactly the opposite
predictions emerge. All other things being equal, intervention is more likely to
prove worthwhile when the beneficiary of the aid is weaker (and its opponent is
stronger), because the beneficiary is then less likely to win without help.
Consequently, intervention is more probable when the impact of victory on the
subsequent performance of a combatant increases with that individual's strength
because this selects for intervention in favour of weaker combatants. The
published literature on hierarchy formation does not reveal how winner and loser
effects actually change with contestant strength and we therefore hope that our
model will spur others to collect such data; in this light we suggest an
experiment which will help to elucidate the nature of winner and loser effects
and their impact on coalition formation in animals.
PMID- 10670948
TI - Assessment of the prevalence of vCJD through testing tonsils and appendices for
abnormal prion protein.
AB - The objective of this study was to determine the age group or groups which will
provide the most information on the potential size of the vCJD epidemic in Great
Britain via the sampling of tonsil and appendix material to detect the presence
of abnormal prion protein (PrP(Sc)). A subsidiary aim was to determine the degree
to which such an anonymous age-stratified testing programme will reduce current
uncertainties in the size of the epidemic in future years. A cohort- and time
stratified model was used to generate epidemic scenarios consistent with the
observed vCJD case incidence. These scenarios, together with data on the age
distribution of tonsillectomies and appendectomies, were used to evaluate the
optimal age group and calendar time for undertaking testing and to calculate the
range of epidemic sizes consistent with different outcomes. The analyses
suggested that the optimal five-year age group to test is 25-29 years, although a
random sample of appendix tissue from all age groups is nearly as informative. A
random sample of tonsil tissue from all age groups is less informative, but the
information content is improved if sampling is restricted to tissues removed from
those over ten years of age. Based on the assumption that the test is able to
detect infection in the last 75% of the incubation period, zero detected
infections in an initial random sample of 1000 tissues would suggest that the
epidemic will be less than 870,000 cases. If infections are detected, then the
model prediction suggests that both relatively small epidemics (800+ cases if one
is detected or 8300+ if two are detected) and larger epidemics (21,000+ cases if
three or more are detected) are possible. It was concluded that testing will be
most informative if undertaken using appendix tissues or tonsil tissues removed
from those over ten years of age. Large epidemics can only be excluded if a small
number of infections are detected and the test is able to detect infection early
in the incubation period.
PMID- 10670949
TI - Longevity and the costs of reproduction in a historical human population.
AB - It has been argued that the priority that natural selection places on
reproduction negatively affects other processes such as longevity and the problem
posed by this trade-off underlies the disposable soma theory for the evolution of
human ageing. Here we examine the relationship between reproduction and longevity
in a historical human population (the Krummhorn, north-west Germany 1720-1870).
In our initial analyses, we found no support for the hypothesized negative
effects of reproduction on longevity: married women who remained childless lived
no longer than women who reproduced and women who had few children lived no
longer than women who had many children. However, more detailed analyses in
relation to socio-economic class revealed that the extent to which reproduction
has an effect on longevity is a function of the level of economic deprivation. We
found that, when possible sources of confound were controlled for (e.g. duration
of marriage and amount of time spent in fecund marriage), there is an
increasingly strong relationship between longevity and reproduction with
increasing poverty.
PMID- 10670950
TI - Resource allocation between reproductive phases: the importance of thermal
conditions in determining the cost of incubation.
AB - Changes in the resources allocated to particular stages of reproduction are
expected to influence allocation to, and performance in, subsequent reproductive
stages. Experimental manipulation of individual investment patterns provides
important evidence that such physiological trade-offs occur, and can highlight
the key environmental variables that influence reproductive costs. By temporarily
altering the thermal properties of starling nests, we reduced the energetic
demand of first-clutch incubation, and examined the effect of this manipulation
on performance during the same and the subsequent reproductive attempts. Compared
with controls, starlings investing less in incubation were more successful in
fledging young, and were more likely to hatch all their eggs if a subsequent
reproductive attempt was made. Our results show that incubation demands can limit
reproductive success, and that resources saved during incubation can be
reallocated to later stages of the same reproductive attempt and to future
reproductive attempts. This study also shows that small changes in thermal
environment can affect breeding success by altering the energetic demands imposed
on incubating parents, independently of the effect of temperature on other
environmental variables such as food supply.
PMID- 10670951
TI - Stable isotopes examined across a migratory divide in Scandinavian willow
warblers (Phylloscopus trochilus trochilus and Phylloscopus trochilus acredula)
reflect their African winter quarters.
AB - The C and N isotopes of feathers from two subspecies of willow warblers
Phylloscopus trochilus trochilus and Phylloscopus trochilus acredula) are
isotopically distinct. Our analysis of 138 adult males from 14 sites distributed
across Sweden shows that the mean delta15N and delta13C values of subspecies
acredula (from latitudes above 63 degrees N) were significantly higher than the
mean delta15N and delta13C values of subspecies trochilus (from latitudes below
61 degrees N). The analysed willow warbler feathers had been moulted in the
winter quarters and the observed isotopic signatures should thus reflect the
isotopic pattern of food assimilated in Africa. The isotopic data observed in
Sweden match the cline in morphology, both showing abrupt changes around 62
degrees N. This result agrees with data from ringing recoveries indicating that
the two subspecies occupy geographically and isotopically distinct wintering
grounds in Africa. Our isotopic data suggest that analysis of stable isotopes of
C and N is a promising method to track wintering quarters of European birds that
migrate to Africa.
PMID- 10670952
TI - Robustness of reserve selection procedures under temporal species turnover.
AB - Complementarity-based algorithms for the selection of reserve networks emphasize
the need to represent biodiversity features efficiently, but this may not be
sufficient to maintain those features in the long term. Here, we use data from
the Common Birds Census in Britain as an exemplar data set to determine
guidelines for the selection of reserve networks which are more robust to
temporal turnover in features. The extinction patterns found over the 1981-1991
interval suggest that two such guidelines are to represent species in the best
sites where they occur (higher local abundance) and to give priority to the rarer
species. We tested five reserve selection strategies, one which finds the minimum
representation set and others which incorporate the first or both guidelines
proposed. Strategies were tested in terms of their efficiency (inversely related
to the total area selected) and effectiveness (inversely related to the
percentage of species lost) using data on eight pairs of ten-year intervals. The
minimum set strategy was always the most efficient, but suffered higher species
loss than the others, suggesting that there is a trade-off between efficiency and
effectiveness. A desirable compromise can be achieved by embedding the concerns
about the long-term maintenance of the biodiversity features of interest in the
complementarity-based algorithms.
PMID- 10670953
TI - Better red than dead: carotenoid-based mouth coloration reveals infection in barn
swallow nestlings.
AB - Nestling birds solicit food from their parents by displaying their open brightly
coloured gapes. Carotenoids affect gape colour, but also play a central role in
immunostimulation. Therefore, we hypothesize that, by differentially allocating
resources to nestlings with more brightly coloured gapes, parents favour healthy
offspring which are able to allocate carotenoids to gape coloration without
compromising their immune defence. We demonstrated that, in the barn swallow
Hirundo rustica, (i) parents differentially allocate food to nestlings with an
experimentally brighter red gape, (ii) nestlings challenged with a novel antigen
(sheep red blood cells, SRBCs) have less bright gape colour than their control
siblings, (iii) nestlings challenged with SRBCs but also provided with the
principal circulating carotenoid (lutein) have more brightly coloured red gapes
than their challenged but unsupplemented siblings and (iv) the gape colour of
nestlings challenged with SRBCs and provisioned with lutein exceeds that of
siblings that were unchallenged. This suggests that parents may favour nestlings
with superior health by preferentially feeding offspring with the brightest
gapes.
PMID- 10670954
TI - Density-dependent aposematism in the desert locust.
AB - The ecological processes underlying locust swarm formation are poorly understood.
Locust species exhibit phenotypic plasticity in numerous morphological,
physiological and behavioural traits as their population density increases. These
density-dependent changes are commonly assumed to be adaptations for migration
under heterogeneous environmental conditions. Here we demonstrate that density
dependent nymphal colour change in the desert locust Schistocerca gregaria
(Orthoptera: Acrididae) results in warning coloration (aposematism) when the
population density increases and locusts consume native, toxic host plants.
Fringe-toed lizards (Acanthodactylus dumerili (Lacertidae)) developed aversions
to high-density-reared (gregarious-phase) locusts fed Hyoscyamus muticus
(Solanaceae). Lizards associated both olfactory and visual cues with locust
unpalatability, but only gregarious-phase coloration was an effective visual
warning signal. The lizards did not associate low rearing density coloration
(solitarious phase) with locust toxicity. Predator learning of density-dependent
warning coloration results in a marked decrease in predation on locusts and may
directly contribute to outbreaks of this notorious pest.
PMID- 10670955
TI - Sex-ratio-distorting Wolbachia causes sex-role reversal in its butterfly host.
AB - Sex-role-reversed mating systems in which females compete for males and males may
be choosy are usually associated with males investing more than females in
offspring. We report that sex-role reversal may also be caused by selfish genetic
elements which distort the sex ratio towards females. Some populations of the
butterflies Acraea encedon and Acraea encedana are extremely female biased
because over 90% of females are infected with a Wolbachia bacterium that is
maternally inherited and kills male embryos. Many females in these populations
are virgins suggesting that their reproductive success may be limited by access
to males. These females form lekking swarms at landmarks in which females exhibit
behaviours which we interpret as functioning to solicit matings from males. The
hypothesis that female A. encedon swarm in order to mate is supported by the
finding that, in release recapture experiments, mated females tend to leave the
swarm while unmated females remained. This behaviour is a sex-role-reversed form
of a common mating system in insects in which males form lekking swarms at
landmarks and compete for females. Female lekking swarms are absent from less
female-biased populations and here the butterflies are instead associated with
resources in the form of the larval food plant.
PMID- 10670956
TI - Genetic support for the evolutionary theory of reproductive transactions in
social wasps.
AB - Recent evolutionary models of reproductive partitioning within animal societies
(known as 'optimal skew', 'concessions' or 'transactional' models) predict that a
dominant individual will often yield some fraction of the group's reproduction to
a subordinate as an incentive to stay in the group and help rear the dominant's
offspring. These models quantitatively predict how the magnitude of the
subordinate's 'staying incentive' will vary with the genetic relatedness between
dominant and subordinate, the overall expected group output and the subordinate's
expected output if it breeds solitarily. We report that these predictions accord
remarkably well with the observed reproductive partitioning between conesting
dominant and subordinate queens in the social paper wasp Polistes fuscatus. In
particular, the theory correctly predicts that (i) the dominant's share of
reproduction, i.e. the skew, increases as the colony cycle progresses and (ii)
the skew is positively associated both with the colony's productivity and with
the relatedness between dominant and subordinate. Moreover, aggression between
foundresses positively correlated with the skew, as predicted by transactional
but not alternative tug-of-war models of societal evolution. Thus, our results
provide the strongest (quantitative support yet for a unifying model of social
evolution.
PMID- 10670957
TI - A simple method of removing the effect of a bottleneck and unequal population
sizes on pairwise genetic distances.
AB - In this paper, we derive the expectation of two popular genetic distances under a
model of pure population fission allowing for unequal population sizes. Under the
model, we show that conventional genetic distances are not proportional to the
divergence time and generally overestimate it due to unequal genetic drift and to
a bottleneck effect at the divergence time. This bias cannot be totally removed
even if the present population sizes are known. Instead, we present a method to
estimate the divergence times between populations which is based on the average
number of nucleotide differences within and between populations. The method
simultaneously estimates the divergence time, the ancestral population size and
the relative sizes of the derived populations. A simulation study revealed that
this method is essentially unbiased and that it leads to better estimates than
traditional approaches for a very wide range of parameter values. Simulations
also indicated that moderate population growth after divergence has little effect
on the estimates of all three estimated parameters. An application of our method
to a comparison of humans and chimpanzee mitochondrial DNA diversity revealed
that common chimpanzees have a significantly larger female population size than
humans.
PMID- 10670958
TI - Glucosinolate genetics and the attraction of the aphid parasitoid Diaeretiella
rapae to Brassica.
AB - The control of insect pests using parasitoids and carnivores has been
successfully applied in protected cropping systems, orchards and forestry. Their
success in annual field crops has been more limited due largely to the
difficulties of attracting and maintaining a sufficient density of parasitoids in
the crop before the levls of the insect herbivores become economically damaging.
Parasitoids are known to be attracted to host-plant volatiles; thus, manipulating
the host-plant chemistry may provide a means of enhancing the attraction of
parasitoids to their prey. In this study we describe the differential attraction
of the braconid wasp Diaeretiella rapae to two near-isogenic lines of Brassica
oleracea which differ in a gene which alters the chemical structure of the
isothiocyanates which are emitted following tissue damage. We demonstrate that,
by enhancing the production of but-3-enyl isothiocyanate in B. oleracea and
Brassica napus (oilseed rape), we can increase the attraction of D. rapae to
these plants under standard field conditions.
PMID- 10670959
TI - Loss of genetic diversity in the endemic Hector's dolphin due to fisheries
related mortality.
AB - The endemic New Zealand Hector's dolphin is considered the rarest species of
marine dolphin with a total abundance of less than 4000. The species is listed as
vulnerable because of fisheries-related mortality due to entanglement in set
nets. The vulnerability of this species is further increased by its fidelity to
local natal ranges and the genetic isolation of regional populations. Here we
present evidence, based on 108 contemporary samples and 55 historical samples
dating back to 1870, of a significant loss of mitochondrial DNA (mtDNA) diversity
in two regional populations of Hector's dolphin. The haplotype diversity (h) was
calculated from sequences of a 206 bp fragment in the mtDNA control region,
designed to identify 13 out of the 14 known maternal lineages. Over the last 20
years, the North Island population has been reduced from at least three lineages
(h = 0.41) to a single lineage (h = 0; p < 0.05). Given its small size,
reproductive isolation and reduced genetic diversity, this population is likely
to become extinct. The diversity of the East Coast South Island population has
declined significantly from h = 0.65 to h = 0.35 (p < 0.05). Based on trend
analysis of the mtDNA diversity, we predict that the East Coast population will
lose all mtDNA diversity within the next 20 years. This time-series of reduction
in genetic variation provides independent evidence of the severity of population
decline and habitat contraction resulting from fisheries and perhaps other human
activities.
PMID- 10670960
TI - Environmental health research: setting an agenda by spinning our wheels or
climbing the mountain?
AB - This paper examines the nature and characteristics of research in environmental
health, viewed as the effects of the environment on human health. It is argued
that most of this work has been predicated on an epidemiological approach which
has yielded significant (if sometimes equivocal) findings about exposure-outcome
relationships. This discussion, however, concentrates on the limited and somewhat
partial view of theory implied in this perspective. It advocates instead a broad
based approach to theory as the basis for understanding significant portions of
the social world. It posits, as illustrations, several social theories and with
examples tries to show how environmental health research might be different.
PMID- 10670961
TI - Managing risk in the city: the role of welfare professionals in managing risks
arising from vulnerable individuals in cities.
AB - Modern cities depend on individualism and the process of contracting. Contracts
between individuals contribute to stability and order in cities. However, this is
challenged by risks and uncertainties especially those relating to vulnerable
individuals who are unable or unwilling to enter into contractual relations. This
paper focuses on the role of caring professions and the impact of new strategies
for managing risks related to vulnerable adults and children, especially the
shift from managing risk in institutions to managing risk in the community. This
paper is based on research funded through the ESRC Risk and Human Behaviour
Programme.
PMID- 10670962
TI - Physician retention in rural communities: the perspective of experiential place
integration.
AB - Rural communities across the United States continue to struggle in their attempts
to recruit and retain physicians. In response to this ongoing problem, health
services researchers have focused on the recruitment of physicians. More
recently, however, researchers have recognized the importance of physician
retention. Nonetheless, there is a scarcity of theories to explain the process of
rural physician retention. This paper provides an overview of retention in health
services research. It then proposes a theoretical perspective on retention called
"experiential place integration." The paper subsequently presents an in-depth
qualitative study of rural physician integration in Kentucky from which a
practical framework of physician integration is constructed. The framework
represents integration as an active developmental process based on the
enhancement of security, freedom, identity and meaning in place.
PMID- 10670963
TI - Image-diagnosis: visualization of community health levels and the impacts of
determinants thereof.
AB - The objective of this study is to develop a tool that visualizes health-level of
communities and the determinants thereof. We developed Image-Diagnosis, which
consists of mapping and star-plotting procedures. This paper presents this method
by applying the statistics in Tokyo. The mapping shows the spatial variance of
health-level and health-determining factors; star-plotting depicts health-level,
as the circle, and health-determining factors, as the arms, in a star-shaped
diagram. The animation of star-plots presents variations in health levels
resulting from the specified changes in health-determining factors according to
the models. Potential contribution to the decision making in urban health policy
was discussed.
PMID- 10670964
TI - A turning tide? Reflections on ideology and health service restructuring in New
Zealand.
PMID- 10670965
TI - Social aspects of AIDS-related stigma in rural Uganda.
AB - In the process of collecting sexual behaviour data through in-depth interviews,
24 respondents offered information on stigma related to HIV-1 infection.
Observations of social relations in public places and families of infected
individuals were made. The findings suggest that although HIV/AIDS-related stigma
has had adverse effects on treatment seeking behaviour of PWAs and coping
mechanisms of their families, a more tolerant attitude is starting to emerge in
this area. Probably, due to improvements in counselling services and home care
schemes for those with AIDS. This supports the call for increased investments in
counselling and community development aimed at caring for people with AIDS
(PWAs).
PMID- 10670966
TI - Ageing and aged care in the People's Republic of China: national and local issues
and perspectives.
AB - China's population is rapidly ageing at a time when former socialist collective
provision and provision by the state in all sectors, especially in social
welfare, is being radically reduced because of economic reform and financial
stringency. The traditional Chinese approach to family care for elderly members
is being encouraged but may be difficult because of smaller family sizes and the
disruption of migration. This paper discusses some urban responses to pressures
for change in care of elderly people, drawing on the example of Guangzhou
(Canton) in southern China, which typifies many of the problems of caring for
elderly people in times of social and economic change. It notes the development
of homes and facilities for elderly people and the emergence of some prestige
homes, often occupied by the better off, which have received both local and
international investment. By contrast, the bulk of elderly people will not be
adequately provided for by a declining public/collective sector. The dilemmas
faced by the Chinese authorities attempting to stimulate local provision for all
elderly people are identified.
PMID- 10670967
TI - Happy in castlemilk? Deprivation and depression in an urban community.
AB - This paper reports findings from a survey conducted in Autumn 1993 in Castlemilk,
Glasgow. The purpose of the survey, commissioned by local service providers, was
to estimate the prevalence of sub-clinical depression, identify at-risk groups
and to specify how the interplay of different factors impacts on people's mental
health. Just under a quarter of residents experienced some emotional distress.
The factors associated with the observed distress were located both within the
biography of those surveyed and the structural features of the locality in which
they lived. It is concluded that service providers can devise strategies to
identify individuals at risk of emotional distress to help them confront their
private troubles. These should however be supplemented at regional and national
levels by a range of policies designed to address structural inequalities.
PMID- 10670968
TI - Consumerist ideology and the symbolic landscapes of private medicine.
AB - The consumption of health care has generally been examined by geographers in
terms of patterns of service utilization by patients. The sites of service
provision have been viewed as locations rather than as contributors to, and
constituents of, urban landscapes. In this paper we argue that perspectives of
the so-called "new" cultural geography can assist in interpreting the urban
landscapes of health care. The case of accident and medical clinics in New
Zealand is examined and used to argue that the underlying ideologies of private
provision and consumerism is reflected in the symbols used in both the built
environment and in advertising.
PMID- 10670969
TI - Spatial distribution of watery diarrhoea in children: identification of "risk
areas" in a rural community in Bangladesh.
AB - To assess the geographic variation of acute watery diarrhoea in children 0 to 5
years old in rural Bangladesh, all cases of "cholera-like" diarrhoea were plotted
on the map. A clustering pattern was noticed, and validated by a nonparametric
clustering test for in-homogeneous population. Several risk areas for the disease
were identified. In these areas, the point prevalence (8.7/1000) was notably
higher than outside the areas (0.41/1000), (95% confidence interval, 15.55
29.30). Parents' education, population density and use of sanitary latrines were
significantly related to the risk areas (p < or = 0.001). The results of this
study indicate that computer-assisted mapping may be useful in defining and
monitoring risk areas for watery diarrhoea in children.
PMID- 10670970
TI - Stigmatization, HIV/AIDS, and communities of color: exploring response to human
service facilities.
AB - HIV and AIDS are rapidly becoming leading causes of death for men and women in
large cities across the US. Epidemiological data indicate that persons of color
in particular have been disproportionately affected by HIV/AIDS. The continuing
growth in the incidence of HIV/AIDS among persons of color implies that human
service facilities will be needed in close proximity. However, there has been
little research exploring response to human service facilities associated with
HIV/AIDS in communities of color. This paper explores community response to
facilities associated with HIV/AIDS by analyzing in-depth interviews with fifteen
Vietnamese and Latino/Latina informal opinion leaders in Orange County,
California. These interviews indicate that the stigma surrounding HIV/AIDS
emanates to a large degree from the social construction of "HIV/AIDS as
homosexuality". Even with the deviance and marginalization associated with
HIV/AIDS, however, creative coping strategies have been developed by families
within the Latino and Vietnamese communities to enable the maintenance of family
ties with persons living with HIV/AIDS.
PMID- 10670971
TI - Uncertainty, reassurance and pollution: the politics of epidemiology in Teesside.
AB - This article focuses upon longstanding controversy surrounding the health impact
of air pollution from steel and chemical industries in the conurbation of
Teesside, in Northeast England. Drawing on Ulrich Beck's analysis of risk, it
presents a commentary on the ways in which epidemiological findings are
incorporated or marginalised in conflicting public health narratives in Teesside,
taking recent epidemiological research on mortality patterns for detailed
scrutiny. I argue that where public health issues are contentious and
politicised, inconclusiveness in such research plays a significant part in
sustaining a "narrative of reassurance" about the possible health or
environmental costs of living close to industrial operations.
PMID- 10670972
TI - Quantitative health research in an emerging information economy.
AB - This paper is concerned with the changing information environment in the U.K.
National Health Service and its implications for the quantitative analysis of
health and health care. The traditionally available data series are contrasted
with those sources that are being created or enhanced as a result of the post
1991 market-orientation of the health care system. The likely research
implications of the commodification of health data are assessed and illustrated
with reference to the specific example of the geography of asthma. The paper
warns against a future in which large-scale quantitative health research is only
possible in relation to projects which may yield direct financial or market
benefits to the data providers.
PMID- 10670973
TI - Urbanization and mental health in Brazil: social and economic dimensions.
AB - While there have been attempts to examine urbanization and the quality of urban
life as special risk factors in the generation of mental illness, the issue is
controversial and remains largely unresolved. In this article particular
consideration is given to the process of contemporary structural transformation
in the Brazilian society leading to urbanization. Selected Brazilian studies of
mental illness in urban areas are described. Economic displacement, or
unemployment, emerges as the most significant risk factor for mental ill-health
and is more important than, for example, rural to urban migration. Current
studies are then criticized for focusing too much on the search for single risk
factors instead of taking the social, structural context into account.
PMID- 10670974
TI - The contribution of coterminosity to joint purchasing in health and social care.
AB - This article examines the context within which coterminosity (the coincidence of
geographical boundaries between two or more organisations) is currently being re
defined, given the development of purchasing in health and social care agencies
in the British welfare system. It explores the current trends within purchasing
and especially the notion of "locality" as a means of promoting "joint working"
between purchasing agencies. In particular, the emergence of general practice as
a focus of purchasing is explored with reference to its involvement in joint
purchasing (or joint commissioning) and its interaction with the "locality". The
article concludes that coterminosity has a contribution to purchasing
organisations but increasingly at a local level such as the general practice or
locality. This local manifestation of coterminosity may minimise the effects of
fragmentation and encourage inter-agency collaboration.
PMID- 10670975
TI - Telecommunications and disabled people: a rural perspective.
AB - In the context of the National Health Service and Community Care Act 1990 this
paper focuses on the role of home- and community-based telecommunication services
in sustaining the life-style and independence of elderly and disabled people in
rural Britain. It draws on findings from a recent survey in the North Cotswolds
to evaluate four models of telecommunication support: telephone trees; community
alarm systems; community teleservice centres (CTCs); and on-line computer
systems. The arguments in favour of a "low-cost-voluntary-care-support-model", a
variant of the CTC, are discussed with respect to client need and community
setting.
PMID- 10670976
TI - Cattle markets and local festivals: development of HIV/AIDS prevention
interventions for specific risk situations in rural northeast Thailand.
AB - In rural Northeast Thailand, risk of sexual transmission of HIV is popularly
perceived to be site-specific. Risk of HIV transmission in local scenarios like
cattle markets and village festivals has not been adequately addressed. This
paper assesses the use of community consultation and formative research to
overcome prevailing assumptions about HIV risk by involving community members in
the process of identifying risks and developing HIV prevention strategies. This
participatory approach can be used to develop prevention programs that are
responsive to the specific context of risk behavior in rural environments.
PMID- 10670977
TI - Community pharmacy in South Africa: a changing profession in a society in
transition.
AB - The analysis of community pharmacy as a profession in transition acquires an
additional dimension in South Africa, since it is inextricably linked to its
social characteristics as well as to the political transformation taking place.
Using data collected by means of a documentary search, interviews with key
informants and a survey of community pharmacists, the paper presents the relevant
societal features and explores some of the complexities associated with the
existing as well as the potential future role of community pharmacy in the
context of changing health services in a society in transition. It concludes that
the changes in community pharmacy and the role it can play in the provision of
Primary Health Care to all the people of South Africa are linked to the greater
transition in society and its future health care services.
PMID- 10670978
TI - Therapeutic landscapes of the Jola, The Gambia, West Africa.
AB - This paper contributes to the 'new' medical geography through its analysis of the
therapeutic landscapes of the Jola of The Gambia. The paper advances the debate
surrounding the conceptualization of medicine and health through a review of
literature on African medicinal systems; it examines in detail the health care
system of the Jola of The Gambia, documenting indigenous human and
ethnoveterinary medical beliefs and practices and focusing in particular on the
role of herbal medicine; and it discusses the interactions and links between
indigenous medicine and biomedicine, thus demonstrating the importance of placing
an understanding of health care systems in different places within an awareness
of global power relations. The paper therefore links cultural perspectives with a
political economy analysis, to highlight the importance of place and specificity
of cultural context when investigating health care beliefs and practices. The
intention of the paper is to present a theoretically informed empirical case
study which reinforces the practical value of a 'new' medical geography.
PMID- 10670979
TI - Talk about cancer: environment and health in Oceanpoint.
AB - Based on an ethnographic study, this paper explores one Australian community's
'popular epidemiology' of the role of the environment on health. Residents
express concern about cancer risks due to contamination from a land-fill dump
site and from radioactivity from previous mining activities. These concerns carry
a range of meanings, not only regarding the threats to the physical place of
Oceanpoint, but the social space the community occupies and the values they
espouse. The perceptions of health risks in this location involve a contest over
the cultural politics of place, the political economy of development and the
sense of a former authentic 'community' that is being lost and disempowered from
controlling its future.
PMID- 10670980
TI - Moving experiences: a qualitative analysis of health and migration.
AB - This paper describes a qualitative analysis of the health and health care
experiences of South Asian Fijian women now living in the lower mainland area of
British Columbia, Canada. A particular focus is put on the health impacts of the
migration experience. A thematic analysis of in-depth interviews informs the
discussion of individual women's, as well as service providers', views of health
meanings, physical and emotional health concerns, experiences with the health
care system, and women's roles as care-givers. The findings have implications for
how health and illness are conceptualized, and how health services are provided
to particular groups in particular places.
PMID- 10670981
TI - The politics of methodology in 'post-medical geography': mental health research
and the interview.
AB - This paper argues that emerging 'post-medical geographies' require attention to
the methodological in order to fully appreciate how different geographical
knowledges are produced and contextualized within the politics of research
relationships. 'Geographies of mental health and illness' are focused upon in
order to argue that the 'peopling' of health research should also be accompanied
by debate about what sorts of methodologies we employ in accessing these
minds/bodies and voices. The research interview is a primary focus here. A
critique of psychoanalytic approaches to geographical research argues that such
'models' of interpretation and management can mean that participants or research
'subjects' can be framed in almost diagnostic categories of behaviour. Empirical
examples of mental health research in Nottingham are used to argue that more
flexible approaches which pay attention to perceived dualisms (such as 'sanity'
and 'insanity'), negotiation, embodiment, socio-spatial contexts and content
within the interview situation may aid in understanding the politics which
encompass geographical health research.
PMID- 10670982
TI - Mortality from non-Hodgkin lymphoma and UV exposure in the European Community.
AB - There has been a large, unexplained rise in the incidence of non-Hodgkin's
lymphoma (NHL) in many countries. It has been hypothesised that increased
exposure to solar ultraviolet (UV) radiation may have been a factor in this
increase. The hypothesis that exposure to ultraviolet radiation is a factor in
NHL can be tested by examining whether geographical variations in UV and in the
incidence of the disease are positively correlated. Previous studies have given
mixed results but some of these have failed to take into account confounding by
socio-economic factors and the multilevel structure of data derived from several
different countries. It was therefore decided to carry out a study using data on
NHL mortality for the period 1971-80 for level II administrative units in 9
countries in the European Community. Estimated levels of solar UV and per capita
GDP were also derived. Poisson regression models of the relationship between NHL
mortality, UV and per capita GDP, taking into account the multilevel structure of
the data, were fitted using the MLn package. Simple models that did not adjust
for the effects of variations in per capita GDP or account adequately for the
structure of the data produced apparent negative or quadratic associations
between NHL and UV. However, further models show that there is a highly
significant positive association between NHL and per capita GDP. Once this is
included in the fixed and random parts of the multilevel model the association
between NHL and UV becomes positive although non-significant (p = 0.081) at the
conventional 0.05 level. These results underline the need to control for socio
economic factors and to take into account the multilevel structure of the data.
Studies using international data that do not do this run the risk of producing
misleading results.
PMID- 10670983
TI - Advice-giving in community pharmacy: variations between pharmacies in different
locations.
AB - The advice and services provided by community pharmacies are viewed by policy
makers as having an increasingly important contribution to make as a primary
health care resource to local populations. However, little attention has been
given to the variations which may exist between pharmacies operating in different
localities. Findings from an ethnographic study of pharmacies illuminate
differences in the nature and quality of advice and services provided by
pharmacies operating in disparate localities. Analysis of qualitative data
suggests that differences in the environment within which pharmacies are located
and organised influence the type of service provided to local populations. The
possibility of an inverse care law operating in relation to the nature of
services in poor urban localities compared to those in rural areas is also
discussed.
PMID- 10670984
TI - Credentialling immigrant physicians in Israel.
AB - Credentialling of immigrant physicians is discussed in the context of two sets of
high-priority values which have remained constant in Israel since its founding:
(a) an open, non-selective migration policy which has resulted in the entry of
thousands of immigrant physicians, (b) the high priority accorded to quality
health care. These values and their social implications are discussed in terms of
the licensing procedures before 1988 and after that date when more stringent
procedures were initiated. These processes are discussed with special reference
to the large number of immigrant physicians that have come to Israel from the
former Soviet Union since 1989.
PMID- 10670985
TI - The geography of dementia: an approach through epidemiology.
AB - Dementia is an extremely common condition among the elderly. Over 100
epidemiological surveys have now been published from many countries.
Methodological differences make comparisons difficult, although meta-studies
carried out in Europe provide baseline material for developed countries. Surveys
within each geographical area which has been studied are discussed. Differences
in the distribution of sub-types of dementia and the resultant challenges to
governments and researchers are set out.
PMID- 10670987
TI - UK and western European late-age mortality: trends in cause-specific death rates,
1960-1990.
AB - Age, sex and cause-specific death rates for the elderly population of 16 western
European countries are examined for 1960, 1970, 1980 and 1990. Over the 30 years,
the all-cause rates have fallen by around 23-41% depending on age and sex.
Mortality from stroke has declined substantially and from cardiovascular
disorders has recently fallen, but cancer health rates have increased among men.
A comparison of the UK death rates with the west European and Swiss rates finds
relative improvement in the UK for male mortality, but that female mortality at
the younger ages has worsened sharply. Cardiovascular and stroke mortality is now
exceptionally high in the UK among females aged 60-64 years and the 1980s trends
for the 60-64 and 70-74 years age groups were unfavourable for several other
causes of death.
PMID- 10670986
TI - Home is where the governing is: social capital and regional health governance.
AB - The relationship between the civic nature of a community and effective political
governance by regional health boards in Canada is explored. A model is proposed
that identifies components of social capital such as trust, commitment and
identity, associationalism, civic participation and collaborative problem
solving. These concepts are then theoretically linked to effective governance, in
particular to reflection of health needs, policy implementation, population
health, fiscal responsibility and administrative efficiency. The generalizability
of this model is discussed, as are current research directions and policy
implications for governments. The conclusion is that governments might want to
incorporate a dual perspective encompassing both the political institutions and
the community structure.
PMID- 10670988
TI - A death in our street.
AB - How do neighbours relate to the dying, and what effect does a death have on a
neighbourhood? After briefly reviewing related literature, the article explores
the concepts of reciprocity and solidarity, using the recent work of Michael
Young to highlight limitations in the work of Philip Abrams. The potential of
suffering to generate neighbourhood solidarity in an increasingly affluent and
private society is considered.
PMID- 10670989
TI - Words in wards: language, health and place.
AB - The role of place in medical encounters which involve language is examined using
theoretical arguments backed by empirical studies. Links between language and
place, health and place and especially language and health are discussed. The
language-health link is developed in terms of explanatory models; how language is
used in medical encounters; and power, dominance and resistance relationships.
Then it is shown how considerations of place enhance knowledge about this link.
The paper closes with a set of research questions which focus on the role of
place.
PMID- 10670990
TI - Guthrie house: a rural community organizing for wellness.
AB - This paper is interested in the issue of community participation and empowerment
in health care provision and decision-making. In Canada, the present scope for
public involvement in planning or managing the state's health and social services
system is limited. This poses a particular problem for rural communities--places
where the provision of health care services has historically been limited when
compared to urban locations. These rural communities are now facing a double
burden as public policy moves increasingly towards a retrenchment of the welfare
state. This paper examines one rural community's response to this double burden.
The village of Elgin in rural Ontario recently established Guthrie House, a
community-based resource center for health and wellness services. Community
participation in this case involved a level of control whereby local citizens
together defined the health and social care services that they saw as best
meeting the needs of their community. This form of community participation is
considerably different from the forms of public involvement in the established
medical system and represents a critical link to 'empowering' the local community
as partners in health care. Through an examination of Guthrie House, the paper
presents a review of some critical 'characteristics' which mark successful
community self-help organizations and concludes with a discussion of the policy
implications for greater community participation. It is argued that such
community participation in health care is a policy option which government should
be paying particular attention to in these times of fiscal constraint, increasing
health care needs and increasing consumer dissatisfaction with government service
provision mechanisms.
PMID- 10670991
TI - National identity and controversy: New Zealand's clean green image and
pentachlorophenol.
AB - In the 1990s regulatory bodies in New Zealand worked to develop guide-lines to
clean up the contamination of land caused by the use of pentachlorophenol in the
treatment of timber. In contrast, there has been little effort to identify and
compensate workers contaminated at these sites. This paper explores some of the
reasons why action over the contaminated land was relatively quickly taken,
whilst there was a lingering controversy over the health of the workers who used
pentachlorophenol. The case study suggests that symbols of national identity can
play an important role in the resolution of controversy.
PMID- 10670992
TI - Primary care needs assessment and resourcing: complementary practice and
geographic perspectives.
AB - This paper considers the use of small area census data in deriving socio-economic
health need indices for primary care practices and assesses how far such indices
are related to practice activity. A particular goal is the derivation of
weightings for resourcing formulae which incorporate the effect of socio-economic
deprivation on activity as well as the more usual allowance for patient age
alone, so ensuring a closer match between needs and resources across both
practices and localities. A case study is undertaken of a health authority in
East London with a population of 380 thousand and 97 primary practices. Total
rates of inpatient and outpatient referral and of prescribing by practices all
show an influence of practice deprivation after allowing for age, and this effect
is enhanced for subcategories such as emergency referrals to A&E departments.
After taking account of practice age structure and deprivation, practice
characteristics themselves (e.g. number of GPs in relation to practice
population) are relatively unimportant influences on activity. The paper
discusses how variation in need may be incorporated into resourcing via
differential weighting.
PMID- 10670993
TI - Is there a geography of alternative medical treatment in The Netherlands?
AB - An increasing number of people are using alternative medical care. The literature
suggests that there are important between place variations, however. This paper
tries to assess the extent of these variations and mechanisms behind them for the
utilization of homeopathy, paranormal healing and manual therapy. Are these
variations a matter of level of supply, degree of urbanization, GP
characteristics or simply a matter of composition of populations? Data are
derived from the Dutch National Surgery of General Practice and analyzed using
multilevel logistic regression models. Between place variation in utilization of
homeopathy is mainly a matter of composition of populations with respect to
health locus of control and religion. With respect to paranormal healing, it is
exclusively a matter of religion. With respect to manual therapy, place
variations are a matter of individual, GP, as well as area characteristics, but a
relatively large amount remains unexplained.
PMID- 10670994
TI - Trauma systems and major injury centres for the 21st century: an option.
AB - Trauma, especially involving accidents and falls is now the leading cause of
death in the UK in the first four decades of life. This paper looks at the
existing pattern of Accident and Emergency Units and suggests that because it has
grown up in a fragmented and poorly co-ordinated fashion and because it is
subjected to demands that it was not designed for, it is inadequate in dealing
with the most severe injury cases. Following collaborative work with researchers
at the North Staffordshire Hospital, the authors propose a system of thirty major
trauma centres to cover the whole of the UK. Each would deal with the most severe
accident cases from surrounding hospitals. Using data from the census and from
health authorities, analysed within a GIS environment, a locational pattern for
these centres is suggested and their catchment areas are outlined.
PMID- 10670995
TI - Melanoma incidence in Connecticut by town of residence.
AB - In an analysis of 2,935 cases of invasive melanoma of the skin diagnosed among
residents of Connecticut's 169 towns in 1990-1994, 12 of the 17 towns with
statistically significantly elevated standardized incidence ratios (SIRs) were on
or near the ocean shoreline (in the extreme southern part of the State). The
distribution of melanoma thickness did not support the hypothesis of greater
detection of clinically less significant cancers in the ocean shoreline area with
high SIRs. In multiple regression analyses, town location (on the ocean
shoreline) was a statistically significant predictor of SIR by town, independent
of socioeconomic indicators and racial composition. Although the effects of
shoreline residence and latitude were difficult to separate, the results should
be useful in planning analytic epidemiologic (i.e. case-control) studies in
specific geographic areas for testing etiologic hypothesis as a basis for
planning public health interventions.
PMID- 10670996
TI - Environmental health metanarratives: an analysis of policy making in Ontario,
Canada.
AB - This paper provides a narrative analysis of a policy document, issued by the
Ontario Premier's Council on Health, Well-Being and Social Justice, entitled "Our
Environment, Our Health". It begins by outlining the background for the
production of the document and establishing the nature of narrative analysis. The
intention of this method is to reveal dominant and suppressed ideas through
identifying narrative, non-stories and counter-stories. It then goes on to
provide an analysis of the overall policy piece and its constituent parts,
healthy ecosystems, healthy communities and healthy workplaces. The document's
power is seen not only in its authorship but also in demonstrating the moral
basis of individual responsibility to achieve collective targets and to undertake
collection action.
PMID- 10670997
TI - Assessing ecologic proxies for household income: a comparison of household and
neighbourhood level income measures in the study of population health status.
AB - This paper examines the validity of using ecologic measures of socioeconomic
status as proxies for individual-level measures in the study of population
health. Based on a representative 5% sample of households in a Canadian province,
the study integrated three sources of information: administrative records of
individual health care utilization, records of deaths and 1986 census records
which contained information on household income and average neighbourhood income.
Thirteen measures of health status were developed from these sources of
information. The hypothesis that risk estimates derived from ecologic income
measures will be attenuated relative to estimates obtained from household income
was not supported. These results provide evidence for the use of ecologic-level
measures of income in studies which do not have access to individual-level income
measures.
PMID- 10670998
TI - Subject loss in spatial analysis of breast cancer.
AB - Possible selection bias from assignment of latitude-longitude coordinates to the
place of residence of all Connecticut women diagnosed with breast cancer from
1992 to 1995 (N = 11,470) was evaluated. Exact address-matching was accomplished
for 8,121 records (70.8%) and an additional 1,722 records (15.0%) were matched
using relaxed criteria. We did not address-match 1,627 records (14.1%) due to
missing address information or limitations of the Geographic Information Systems
street file. The age-adjusted likelihood of address-matching records was
significantly greater for women of color, those born within Connecticut,
residents of urban locales or census tracts with low median family incomes and
those cases diagnosed nearer to 1992. Few differences in address-matching were
attributable to tumor characteristics or therapeutic modality.
PMID- 10670999
TI - Sociodemographic and geographic patterns of firearm suicide in the United States,
1989-1993.
AB - This study identified the sociodemographic and geographic patterns of using
firearms to commit suicide in the United States. Data from the Mortality Detail
Files (1989-1993) were analyzed using logistic regression. The adjusted odds of
using firearms increased with age among men and decreased among women. Widowed
men and married women had the highest odds of using firearms. The odds were
highest among those without college education, in nonmetropolitan areas and in
the East South Central and West South Central geographic divisions. The
likelihood of using firearms to commit suicide varies significantly across
sociodemographic and geographic subgroups of the US population and parallels
patterns of gun ownership. The results of this study suggest that regional
cultural factors play an important role in accounting for the differential rates
in suicidal behavior involving firearms.
PMID- 10671000
TI - The decrease of life-expectancy at birth in Romania: some crisis contributing
factors.
PMID- 10671001
TI - Behind the crumbling walls; the re-working of a former asylum's geography.
AB - This paper attempts to examine the effects of deinstitutionalization on a former
asylum's human and physical geography, through a case study of St Lawrence's
Hospital, Bodmin, UK. It researches the inevitably impermanent geography of an
asylum in the process of being 'run down'. The paper includes an empirical
account of the rationalization of a former asylum, reconstructing an east to west
migration of activities across the site. It deals with St Lawrence's as a
'stigmatized' place unable to escape the mark of its asylum past, and as a place
that staff and local people cannot imagine being used for anything other than
land uses associated with 'mad people' or other marginal groups in society. The
paper deals with how St Lawrence's is regarded by some as a 'community', people
who recall with a measure of affection how the asylum used to be a 'home' as well
as a 'workplace', a nostalgia which rebounds into suspicion about the dismantling
process. Fundamentally, the paper aims to tease out and work through the hopes
and fears that now surround the former asylum's environment.
PMID- 10671002
TI - Integrating space into a reactive theory of the asylum: evidence from post-Civil
War Georgia.
AB - Absent from the geographical literature on the 19th century asylum is a reactive
theory of social control. Such an approach focuses on the importance that
families and communities of the insane played in guiding institutionalization.
Thus far, reactive theory has emphasized how social distance within communities
shaped public reaction to mental illness and hence the admission decision.
Unfortunately, it ignores the importance of spatial distance from the asylum in
molding utilization patterns. Using evidence from asylum admissions in post-Civil
War Georgia, this paper explores the necessity of adopting a reactive theory and
the even greater necessity of integrating space into reactive theory. Such a
project requires going beyond traditional treatments of spatial distance as a
geometric barrier and examining the politics of distance, that is, how the
meaning of journey to the asylum was open to competing and conflicting
constructions.
PMID- 10671003
TI - Sentenced in sorrow: the role of asylum in the Jean Gianini murder defence.
AB - This paper describes the role played by the notion of asylum in the legal battle
over confessed murderer Jean Gianini's mental competence and commitment. Gianini
was a 16 year old who murdered his former teacher in a small upstate New York
town in 1914. His trial was the first in the US to employ the Binet-Simon
intelligence test as a defence and featured a clash of expert witnesses whose
credibility was based upon their residence and work in asylums. The verdict of
'not guilty due to criminal imbecility' was due to the defence team's successful
portrayal of the asylum as a punishing prison from which the defendant would
never be released.
PMID- 10671004
TI - 'She thinks this is the Queen's Castle': women patients' perceptions of an
Ontario psychiatric hospital.
AB - Drawing on the detailed information contained in patient case files, this study
explores women patients' perceptions of the Ontario Hospital, Cobourg, a
psychiatric facility for women which operated from 1920 to 1974. The paper
concludes that, while twentieth-century psychiatry promoted an image of asylums
as modern medical facilities, women patients continued to view these institutions
as 'crazy houses', 'havens' and 'prisons'. It was not until the 1950s and 1960s,
the eve of the decline of the authority of scientific psychiatry, that some women
patients began to conceive of psychiatric hospitals as 'medical' facilities where
therapeutic care could be sought.
PMID- 10671005
TI - Across the water: reviewing geographical studies of asylums and other mental
health facilities.
AB - It is possible now to identify a small field of geographical studies exploring
how space, place, environment and landscape are bound up in the worlds of people
experiencing mental health problems. Some of these studies take seriously the
institutions which have been provided to shelter, control, care for and even cure
such people, and this interest has often touched upon the rise of the 'asylums'
in Europe and North America (chiefly as an eighteenth- and nineteenth-century
phenomenon). This paper surveys the geographical literature tackling asylums and
other mental health facilities, and then offers an interpretation of the
theoretical claims and substantive research undertaken in this respect by Michael
Dear and various co-workers. Running through the paper is an argument about the
need for studies of 'asylum geographies' to be attentive to what Gunnar Olsson
terms 'ontological transformations' between thoughts and things.
PMID- 10671006
TI - Moral architecture: the influence of the York Retreat on asylum design.
AB - Institutional and architectural history places the asylum alongside the prison
and other institutional types whose architectural characteristics emphasized
confinement and control. This history obfuscates important differences in how
ideas about treatment were represented in the particular design of these
institutions; in other words, how the structure of a place became part of its
discourse. What becomes obvious in nineteenth-century, asylum architecture is the
influence of a small Yorkshire private asylum built by a Quaker, William Tuke, in
1796. The York Retreat, in form, solidified the ideas of 'moral treatment' in
design and in turn assumed an exalted character in the design of late nineteenth
century asylums. Every researcher working in the field of the history of insanity
acknowledges the importance of this event and its impact on the discourse of
insanity for the century to follow. Few however talk about how its unique design
was incorporated as part of this discourse.
PMID- 10671007
TI - The geography of mental health in Dunedin, New Zealand.
AB - The process of deinstitutionalization of people with chronic mental disabilities
in Western countries has often produced a spatial concentration of ex-psychiatric
patients, and of mental health services, in inner city urban neighbourhoods. In
this paper, the geography of mental health services and patients in Dunedin is
examined, and it is shown that a concentration does exist in one neighbourhood.
The history and characteristics of this neighbourhood are described. The key
factors in contemporary New Zealand that have generated this spatial pattern are
then considered, and Dunedin's centralized mental health geography is contrasted
with the North American "zone of dependence" phenomenon. The paper concludes by
considering to what extent Dunedin's emergent geography of mental health provides
a supportive environment for people with mental illnesses, and exploring the
policy implications for health care planners and service providers.
PMID- 10671008
TI - Geographical change in residential care provision for the elderly in England,
1988-93.
AB - This paper offers an investigation of the spatial consequences of changes in the
structural organization of residential care in England between 1988 and 1993.
Data from various government publications were analysed using descriptive and
spatial statistical methods. While the study period witnessed an overall
levelling of residential care growth, the independent (i.e. private and
voluntary) sector's share of all elderly residents in England increased from 56%
to 73%. At both national and intra-regional scales, the structural changes
resulted in an increasing geographical concentration of public sector residents
and a moderate trend towards a more uniform spatial distribution of private
residents.
PMID- 10671009
TI - Dementia and help with household tasks: a comparison of cases and non-cases.
AB - This paper is based on data, relating to people aged 75+ living in the community,
from the city of Liverpool and from a rural area of North Wales. It compares
those suffering from cognitive brain disorders with those identified as being
cognitively unimpaired. Levels of need, and sources of help with a range of
domestic and home maintenance tasks are identified. Results show that most help
for those who are cognitively impaired comes from relatives living in the same
household, while help for those who are physically impaired comes primarily from
spouses or relatives living in different households. Cases do not demonstrate a
higher level of use of formal services than non-cases. Implications for policy
and practice are discussed.
PMID- 10671010
TI - Gendered health policies and a women's movement: the Gypsy case.
AB - Health concepts depend on socially constructed hygiene practices. Many accounts
of "traditional" Gypsy hygiene make gender differentiation primary, implying that
traditional health practices reinforce patriarchy and emphasizing the special
needs of Gypsy women. This paper argues, however, that the position of women is
contested in Romani society. Although prioritizing the more apparent health needs
of women and small children appeals to health professionals, this cannot by
itself create an effective critique of the health system's response to Gypsy
needs. The emergence of a Gypsy women's movement has led to a new critique, and
challenge to the victim image of women.
PMID- 10671011
TI - Nineteenth century Canada: indigenous place of dis-ease.
AB - During the nineteenth century period of intensive European Expansion into Canada,
place was experienced with dis-ease by indigenous people. Not only was there less
land available for people of the First Nations to live on as in the past
centuries, but their intimate relationship with the land was disturbed causing a
dis-ease, as their ability to experience place through ceremony was denied. The
effects of this process of Euro-Canadian invasion within Canada created a sense
of dis-ease, a sense of being out of place for indigenous people. It is my
contention that in order to understand health, an awareness of the dynamic
connection between a people and their land is needed, recognizing that a
quintessential human quality is to imbue the world with meaning in the creation
of sense of place. Through examination of a variety of published and unpublished
material, archival sources, memos, letters, official documentation, I explore the
effects of control of the place of First Nations, on the health and healing
practices of the indigenous people.
PMID- 10671012
TI - An entropy-based algorithm for detecting clusters of cases and controls and its
comparison with a method using nearest neighbours.
AB - A new method for detecting disease clustering based on entropy is presented. For
this method cases and controls are plotted on a map. The map is divided into
regions. The entropy of the space is calculated as the log of the number of
possible ways of placing the cases and controls in the various regions given the
total number of cases and controls and the number of cases and controls in each
region. The power of the entropy technique is tested against the power of the
nearest neighbour technique (NNT). The entropy method is shown to be
substantially more powerful than the NNT when there is more than one cluster in
the space or when the clusters are near the boundary of the space.
PMID- 10671013
TI - Allocating resources in health care: alternative approaches to measuring needs in
resource allocation formula in Ontario.
AB - Maintaining or improving the welfare of the population is a complex issue
involving individual and collective actions and institutions. Despite questions
regarding the relevance of health care systems to these aims, they remain vital
policy and treatment arenas with respect to curative and preventative regimes. As
a component of social welfare, health care resources should be distributed
equitably, according to need for health care. This paper evaluates alternative
indicators of health status within Ontario against self-reported health as a
means of allocating health care resources. Proxies of need for health care
include standardized mortality ratios (based on the population aged 0-64) and a
socioeconomic based indicator. Mortality indicators are found to be more closely
correlated with self-reported health status than the socioeconomic indicator,
suggesting that mortality is better able to reflect variations in health status
and health care needs.
PMID- 10671014
TI - Social and local variations in the use of urban neighbourhoods: a case study in
Glasgow.
PMID- 10671015
TI - Health and nature in the 19th century Australian women's popular press.
AB - This paper asks how health and nature are represented in the Australian women's
press during the late nineteenth century. A time of significant social change
during which women, and sympathetic male colleagues, challenged traditional roles
as pathological creatures of the domestic sphere, this period is explored through
the writing of women working for popular magazines. As women captured,
transformed and redeployed stereotypical views of them as essentially and
naturally ill, they consolidated their push into the public realm, while also
convincing themselves and others of their vital place in the private sphere, but
as capable, well and fit creators of people and of a nation.
PMID- 10671016
TI - Explaining geographies of health care: a critique.
AB - This paper considers the ways in which geographers have sought to explain the
spatial organisation of health care services. It does so at three interlocking
scales: the global/international, the national, and the local. It considers the
substantive adequacy and explanatory problems associated with different
perspectives and also discusses the normative implications of alternative
interpretations of patterns of health care services. The paper notes the ways in
which some conventional geographies of health care, which seemed to postulate
convergence towards greater egalitarianism in service provision between and
within states, have been challenged by changing economic circumstances, and by a
changing political and intellectual agenda. The paper also considers some
emerging geographies of community-based struggles around health services and
discusses their potential and limitations. Finally there is a discussion of the
potential contribution, if any, of a distinctively geographical perspective on
health care.
PMID- 10671017
TI - Modernization and health care in contemporary China.
AB - This paper provides an analysis of the changes that have occurred in the Chinese
health care system in the reform era, post-1978. The economic reforms have
brought significant benefits to many Chinese people, but the benefits have not
been distributed evenly throughout Chinese society. The paper evaluates some of
the evidence indicating deterioration in both the quality and quantity of health
care services in the reform era. There is some alarming evidence that rural
women, especially those living in the country's poorest regions, have been
experiencing lower levels of accessibility to health care, and increasing levels
of both morbidity and mortality. It is also evident that during the reform era
the gap between service levels in rural areas and the cities has widened, and
that chronic poverty still exists in large parts of the countryside. It is
important to stress that these inequalities were not created by the economic
reforms--in fact they were first observed during the supposedly egalitarian era
associated with Mao Zedong. The economic reforms and the widespread
implementation of market socialism in Chinese society, have, in general, been
associated with improved health status and greater access to health care. It is
also apparent, however, that pre-existing inequalities have not been eradicated
by the reforms, and, particularly along the lines of gender and geography, the
evidence points to a widening of inequality.
PMID- 10671018
TI - Does housing tenure predict health in the UK because it exposes people to
different levels of housing related hazards in the home or its surroundings?
AB - In the UK housing tenure (whether the dwelling is owner occupied or rented) has
consistently been found to be associated with longevity and with a number of
measures of health. It has been argued that it is a good measure of material
circumstances, and it is often incorporated into area based measures of social or
material deprivation. However there is little published research on whether
housing tenure predicts mortality and morbidity simply because it is an indicator
of material well being, or whether, in addition, different categories of housing
tenure expose people to different levels of health hazards in the dwelling itself
or in the immediate environment. In this paper we examine, using data on adults
aged 40 and 60 from socially contrasting neighbourhoods in Glasgow, Scotland,
whether housing tenure is associated with housing stressors (e.g. overcrowding,
dampness, hazards, difficulty with heating the home) and with assessment of the
local environment (e.g. amenities, problems, crime, neighbourliness, area
reputation and satisfaction), and whether this might help to explain tenure
differences in long-standing illness, limiting long-standing illness, anxiety and
depression. Controlling for income, age and sex, housing stressors independently
predicted limiting long-standing illness; assessment of the area and housing type
independently contributed to anxiety; and housing stressors, housing type and
assessment of the area independently contributed to depression. This suggests
that housing tenure may expose people to different levels of health hazards, and
has implications for urban housing policies.
PMID- 10671019
TI - Community characteristics as predictors of perceived HMO quality.
AB - We model the impact of community characteristics on people's perceptions of the
quality of their health care experiences in HMOs. We focus on three community
characteristics: sense of community, population density, and population
diversity. Sense of community refers to people's perception of interconnection,
shared responsibility, and common goals. Population density and population
diversity are community characteristics that affect transactions costs in terms
of time and energy, and affect people's perceptions of their community. We use
data from a 1993 Florida poll to estimate the relationship between HMO members'
perceptions of problems with health care experiences (cost, choice, access,
satisfaction) and community characteristics. We find that all three community
variables are significantly associated with perceptions of health care problems.
We also find that effects of community variables operate differently for those in
HMOs vs. those under traditional insurance. This study is consistent with
research showing that community characteristics impact the health status of
community institutions. Results suggest that providers may be able to improve
care by being more responsive to individuals' need for community, that providers
and communities can mutually gain by collaborating to improve community health,
and that it may be cost-beneficial to factor community issues more strongly into
health care policy.
PMID- 10671020
TI - Diminishing regional contrasts? The east-west-divide in health behaviour among
Finnish adolescents.
AB - We studied whether differences in health behaviour between Eastern and Western
Finland have changed between 1977 and 1993 and whether adjusting for socio
economic characteristics changes the relationship between region and health
behaviour. The Adolescent Health and Life-style Survey data have been collected
biannually by mailed questionnaires from nationally representative samples of 16-
and 18-year-olds (n = 27,785). The response rate varied from 79 to 83% by year.
According to logistic regression analyses, smoking and physical activity were as
prevalent and changes over time similar in both regions. In alcohol, high fat
milk and female butter use the East-West-difference persisted over time. Regional
differences were mainly explained by socio-economic variation between the two
regions.
PMID- 10671021
TI - African mortality and the new 'urban penalty'.
AB - This paper reviews trends in rural/urban under-5 mortality differentials in Sub
Saharan Africa in historical perspective, with particular attention to the case
of Kenya. The rural/urban mortality gap has narrowed within the last half
century, but while this was largely due to rapidly falling rural infant and
childhood mortality over most of the period, in recent years it has been due
primarily to a stalling and even upturn in urban under-5 mortality as urban
economic and environmental conditions have sharply deteriorated in rapidly
growing cities. Policy attention and resources need to be directed to large urban
areas to prevent further deterioration of urban mortality and associated health
conditions.
PMID- 10671022
TI - Measuring access to primary medical care: some examples of the use of
geographical information systems.
AB - This paper explores the potential for geographical information system technology
in defining some variables influencing the use of primary care medical services.
Eighteen general practices in Scotland contributed to a study examining the
accessibility of their services and their patients' use of the local Accident and
Emergency Department. Geo-referencing of information was carried out through
analysis of postcode data relating to practices and patients. This information
was analyzed using ARC/INFO GIS software in conjunction with the ORACLE
relational database and 1991 census information. The results demonstrate that GIS
technology has an important role in defining and analyzing the use of health
services by the population.
PMID- 10671023
TI - Violent death in young people in the city of Sao Paulo, 1991-1993.
AB - This paper aims to describe the principal causes of violent deaths among young
people in the city of Sao Paulo, Brazil. Data from routine mortality statistics
were used in the analysis. Young males were found to have a dramatically
increased risk of death from violent causes especially those resident in lower
income areas of the city. Possible explanations for these findings include
economic instability generating social and cultural inequalities.
PMID- 10671024
TI - Reply to Davis and colleagues: Twice weekly, directly observed treatment for HIV
infected and uninfected tuberculosis patients: cohort study in rural South
Africa.
PMID- 10671025
TI - [Neuroprotection and cerebral ischemia. Symposium proceedings].
PMID- 10671026
TI - [Self-expanding prosthesis and esophageal cancer].
PMID- 10671027
TI - Professor Andre Collet 1945-1999.
PMID- 10671028
TI - Current awareness in NMR in biomedicine.
PMID- 10671029
TI - Mycoplasma pneumoniae-associated Henoch-Schonlein purpura nephritis.
PMID- 10671030
TI - Ambulatory blood pressure monitoring for evaluation of hypertension in children.
PMID- 10671031
TI - Oxalate nephrocalcinosis in renal tubular dysgenesis.
PMID- 10671032
TI - Implementing clinical governance in the United Kingdom: the role of a regional
haematology group. Northern Regional Haematologists Group.
PMID- 10671034
TI - Selected papers from the 18th Annual Conference on Peritoneal Dialysis.
Nashville, Tennessee, USA. February 1998.
PMID- 10671033
TI - The geographic pattern of beta-thalassaemia mutations in the Portuguese
population.
PMID- 10671035
TI - British Society for Haemostasis and Thrombosis autumn meeting. Cambridge, United
Kingdom, 22-24 September 1999. Abstracts.
PMID- 10671036
TI - Inhibition of xanthine oxidase by flavonoids.
AB - Various dietary flavonoids were evaluated in vitro for their inhibitory effect on
xanthine oxidase, which has been implicated in oxidative injury to tissue by
ischemia-reperfusion. Xanthine oxidase activity was determined by directly
measuring uric acid formation by HPLC. The structure-activity relationship
revealed that the planar flavones and flavonols with a 7-hydroxyl group such as
chrysin, luteolin, kaempferol, quercetin, myricetin, and isorhamnetin inhibited
xanthine oxidase activity at low concentrations (IC50 values from 0.40 to 5.02
microM) in a mixed-type mode, while the nonplanar flavonoids, isoflavones and
anthocyanidins were less inhibitory. These results suggest that certain
flavonoids might suppress in vivo the formation of active oxygen species and
urate by xanthine oxidase.
PMID- 10671037
TI - [Health promotion and health care in public health service of Bavaria.
Proceedings of a meeting. Amberg, 19-21 October 1998].
PMID- 10671038
TI - Commentary: three decades of the inverse care law.
PMID- 10671039
TI - Commentary: impact on health needs assessing from different angles.
PMID- 10671040
TI - Decisions to withdraw treatment. Treatment can sometimes be withdrawn at home.
PMID- 10671041
TI - Decisions to withdraw treatment. Courts can help resolve disagreement in
difficult cases.
PMID- 10671042
TI - Decisions to withdraw treatment. Most decisions are based on subjective
appraisal.
PMID- 10671043
TI - Incidence of venous thromboembolism in users of combined oral contraceptives.
Risk is particularly high with first use of oral contraceptives.
PMID- 10671044
TI - Partnership with patients. Local communities have role in influencing health
policy.
PMID- 10671045
TI - Partnership with patients. Modern antipaternalism needs to be invigorated.
PMID- 10671046
TI - Partnership in patients. Perspectives must be reconciled.
PMID- 10671047
TI - Partnership with patients. Doctors in Egypt deal with patients in their own way.
PMID- 10671048
TI - Partnership with patients. Family doctors are part of team.
PMID- 10671049
TI - Partnership with patients. Teamwork is necessary.
PMID- 10671051
TI - Hyperbilirubinaemia in term infants. Hyperbilirubinaemia is a marker for
inadequate breast feeding.
PMID- 10671050
TI - Partnership with patients. A little knowledge can be a dangerous thing.
PMID- 10671052
TI - Intervention for late life depression in residential care. How much trial and
error should we tolerate in community trials?
PMID- 10671053
TI - Intervention for late life depression in residential care. Important research
seems to have been greeted with only two faint cheers.
PMID- 10671055
TI - Diagnosing Lyme disease. Patients have to learn to help themselves.
PMID- 10671054
TI - Intervention for late life depression in residential care. Cochrane preferred to
use "effective" where other people used "efficacious".
PMID- 10671056
TI - Intervention for late life depression in residential care. Cochrane may not have
been first to define efficacy and effectiveness.
PMID- 10671057
TI - Case report of a Thai male cystic fibrosis patinet with the 1898+ 1G-->T splicing
mutation in the CFTR gene: a review of East Asian cases. Mutations in brief no.
196. Online.
AB - Cystic fibrosis (CF) is the most common fatal autosomal recessive multisystem
disorder, which occurs mainly in European-derived populations. The incidence of
CF varies between 1 in 2000 to 3000 live-births in various ethnic groups. The
disease is rare in East Asians. Here we report a 9 year old Thai male patient,
who was diagnosed to have CF based on recurrent pneumonia, a slow weight gain,
pancreatic insufficiency and repeatedly elevated sweat chloride levels by two
different methods. A comprehensive genetic analysis showed the splicing mutation,
1898+ 1G-->T, which was apparently of maternal origin. Literature search found 39
documented cases of CF patients in East Asians. CFTR (MIM# 602421) genotyping was
performed in 14 patients including our patient and in 9 of them a CF allele was
identified. The findings seem to indicate that the splicing mutations, 1898+ 1G-
>T and 1898+ 5G-->T are more common in East Asian CF patients.
PMID- 10671058
TI - Mutation in the nerve-specific 5'non-coding region of Cx32 gene and absence of
specific mRNA in a CMTX1 Italian family. Mutations in brief no. 195. Online.
AB - Charcot-Marie-Tooth type I demyelinating neuropathies are genetically
heterogeneous disorders (chrmosome 17,1,X). There are at least three genes on X
chromosome, the more frequently involved being Cx32 in Xq13.1. Cx32 encodes for
connexin-32, a gap junction protein of 283 aminoacids. We report the results of
molecular studies in a CMTX1 Italian family, in which the mutation, found in the
5'-UTR, resulted in an abnormal mRNA connexin-32 expression. Mutations in PMP22
and P0 genes were also excluded in this family. Cx32 gene analysis carried out by
PCR-SSCP on family members genomic DNAs, running a 321 bp fragment spanning the
TATA box, the trasciptional start site, and the non coding exon 1b, revealed a
shift correlated with a transition from C to T at position 40 of exon 1b of the
12 affected members, while was not found in the controls. Then the RT PCR-SSCP on
cDNA from two peripheral nerve biopsies of two heterozygous females of the family
were sequenced showing only the wild-type alleles and suggesting that mutated
mRNAs were too unstable to be detected. The result also suggests a regulating
role of the 5'-UTR of Cx32 mRNA.
PMID- 10671059
TI - A novel mutation of the down-regulated in adenoma gene in a Japanese case with
congential chloride diarrhea. Mutations in brief no. 198. Online.
AB - Congenital chloride diarrhea (CLD) is an autosomal recessive disease
characterized by excretion of watery stool with a high chloride content.
Pathogenesis of CLD is a deficient absorption of chloride in exchange for
bicarbonate in the ileum and the colon. In 1996, it was reported that 36 patients
with CLD had mutations in the down-regulated in adenoma (DRA) gene; 32 Finnish
patients had a three base deletion (951delGGT), 2 Polish patients had a one base
mutation (371AtoT) and 2 Polish patients had a one base deletion (344delT). In
this study we analyzed the DRA gene in a Japanese boy patient with CLD and in
members of his family. The patient was found to have a two base deletion (TT) at
nucleotide 1526-1527 within codon 509 which results in a frameshift leading to a
permature stopping at codon 517. The patient was homozygous for the deletion, his
parents and brother were heterozygous, and his sister was normal. This is the
first case of CLD identified to carry a mutation of the DRA gene in Asia.
PMID- 10671060
TI - A novel splice site mutation of the EXT2 gene in a Finnish hereditary multiple
exostoses family. Mutations in brief no. 197. Online.
AB - Hereditary multiple exostoses is a dominantly inherited disease characterized by
multiple benign osteochondromas. The affected individuals have an increased risk
of developing sarcoma. A large Finnish family with hereditary multiple exostosis
was analyzed to find the disease-causing mutation. Blood samples were obtained
from 35 family members, including 21 affected and 14 unaffected individuals.
Using 2-point linkage analysis the EXT phenotype was shown to be linked to the
recently cloned EXT2 gene on chromosome 11p11. The coding region of the gene was
sequenced and a previously unreported splice site mutation found. This G to T
transversion within a 5-prime splice donor site following exon 6 was shown to
cause aberrant splicing of RNA. The described change is considered to be a novel
disease-causing mutation in the EXT2 gene.
PMID- 10671061
TI - Lys650Met substitution in the tyrosine kinase domain of the fibroblast growth
factor receptor gene causes thanatophoric dysplasia Type I. Mutations in brief
no. 199. Online.
AB - Thanatophoric dysplasia (TD) is one of the most common neonatal lethal skeletal
dysplasias with micromelic shortening of the limbs, relative macrocephaly, flat
vertebral bodies and a narrow thorax. TD has been divided into two types, type I
(TD1) and II (TD2), based on clinical, radiological, histological, and molecular
criteria. We identified a A to T heterozygous base subsitution at position 1949
predicted to cause a Lys650Met substitution in a term infant with TD1. This
mutation has been previously described in one case of TD1 and three cases of
severe achondroplasia with acanthosis nigricans and mental retardation.
Interestingly, all cases with the Lys650Met mutation have the same unusual
curvature of the tibia and/or fibula.
PMID- 10671062
TI - A genetic polymorphism in the human HOXB1 homeobox gene implying a 9bp tandem
repeat in the amino-terminal coding region. Mutations in brief no. 200. Online.
AB - In man there are 39 homeobox genes of the HOX family in four loci, HOXA, HOXB,
HOXC and HOXD on chromosomes 7, 17, 12, and 2. We discovered the existence of two
major alleles, termed a and b, of gene HOXB1. They differ at a specific position
in the 5' portion of the coding region. Sequencing the two alleles revealed that
the allele HOXB1A, contains two copies of the 9bp sequence 5'ACAGCGCCC3',
starting at position 65 of the coding region, whereas the allele HOXB1b contains
three copies of this sequence (Fig. 1). As a consequence, the allele HOXB1b
encodes a homeoprotein containing two copies of the tripeptide HisSerAla,
starting at amino acid residue 25, which is present in only one copy in allele
HOXB1a. We analyzed 250 individuals and found that the allelic frequencies of
HOXB1a and HOXB1b were 78.8% and 21.2%. The murine homologue contains only one
copy of the 9bp repeat (Fig. 1). 7 mouse strains, namely 129, BALB/c, C57BL/6,
C57BL/10, CAST/Ei, C3H and SPRET/Ei, are homozygous for this allele. The allele
present in gibbon and rhesus monkey appears to be identical to the human HOXB1b
(Fig. 1).
PMID- 10671063
TI - A new nonamyloid transthyretin variant, G101S, detected by electrospray
ionization/mass spectrometry. Mutations in brief no. 201. Online.
AB - Familial amyloidotic polyneuropathy is caused by transthyretin (TTR) variants.
The identification of new variants with and without amyloidosis may help to
clarify the mechanism of amyloid fibril formation. We detected several variant
TTRs from patients with and without symptoms of amyloidosis using mass
spectrometry (MS). TTR was isolated by mixing test serum with anti-transthyretin
antiserum, and the generated immunoprecipitate was analyzed by high performanced
liquid chromatography/electrospray ionization (HPLC/ESI) MS. Variant TTRs showed
extra peaks in addition to normal TTR peaks. A variant found in nonamyloid group
was sequenced by HPLC/ESI tandem MS using peptides obtained by protelytic
digestion of TTR and by DNA analysis. The structure was new, [G101S], and was
found in a 74 years old Japanese male. This mutation results from substitution in
a CpG hot spot. The substitution in the surface loop, 98-102, between F and G b
strands may not cause amyloid formation.
PMID- 10671064
TI - Hereditary nonpolyposis coloretal cancer: identification of novel germline
mutations in two kindreds not fulfulling the Amsterdam criteria. Mutations in
brief no. 203. Online.
AB - Hereditary nonpolyposis colon cancer results from heritable defects in the MLH1,
MSH2, PMS1 and PMS2 genes, which encode proteins involved in the mismatch repair
process. In this work we report the identification of two novel germline
mutations in the MLH1 gene from two unrelated HNPCC families. The two affected
families do not fulfill the Amsterdam criteria. In family 1 we found a missense
S93G mutation, which lies in a MLH1 domain critical for its MMR functions. In
family 2 we found a two nucleotide insertion (AG) in position 523 from the AUG
which determines an early stop codon at position 606 (codon 203). In both
families the mutant alleles cosegregate with the cancer phenotype.
PMID- 10671065
TI - Identification of 9 novel IDS gene mutations in 19 unrelated Hunter syndrome
(mucopolysaccharidosis Type II) patients. Mutations in brief no. 202. Online.
AB - Hunter syndrome is an X-linked lysosomal storage disorder caused by a deficiency
of the lysosomal enzyme iduronate-2-sulfatase (IDS). The IDS deficiency can be
caused by several different types of mutations in the IDS gene. We have performed
a molecular and mutation analysis of a total 19 unrelated MPS II patients of
different ethnic origin and identified 19 different IDS mutations, 9 of which
were novel and unique. SSCP analysis followed by DNA sequencing revealed four
novel missense mutations: S143F, associated with the 562C-->T polymorphism,
C184W, D269V and Y348H. Two novel nonsense mutations were found: Y103X (433C-->A)
and Y234X (826C-->G). In two patients two novel minor insertions (42linsA and
499insA) were identified. In one patient a complete IDS deletion was found,
extending from locus DXS1185 to locus DXS466).
PMID- 10671066
TI - Mutations of the human tyrosinase gene associated with tyrosinase related
oculocutaneous albinism (OCA1). Mutations in brief no. 204. Online.
AB - Mutations in the human tyrosinase gene produce tyrosinase-related oculocutaneous
albinism (OCA1, MIM #203100). Tyrosinase is a copper containing enzyme and is
responsible for catalyzing the rate limiting step in melanin biosynthesis, the
hydroxylation of tyrosine to dopaquinone. We report 13 new mutations in the
tyrosinase gene associated with OCA1A (without pigment) and OCA1B (with pigment)
including 9 missense mutations (H19Q, R521, R77C, G97R, C289R, L312V, P313R,
F340L and H404P), two nonsense mutations (W80X and R116X) and two frameshift
mutations (53delG and 223 delG). Our previous work has defined clusters of
missense mutations that appear to represent functional domains of the enzyme, and
three of the missense mutations fall into these clusters including two (F340L and
H404P) that flank the copper B bindng site and the missense mutation R52I that is
located in the amino terminal end cluster of the protein. The G97R missense
mutation is the first identified within the epidermal growth factor (EGF)-like
sequence and the H19Q missense mutation alters the cleavage site of the signal
peptide sequence. Mutational analysis can provide a definitive diagnosis of the
type of OCA as well as help structure/function analysis.
PMID- 10671067
TI - Mutations of the human P gene associated with Type II oculocutaneous albinism
(OCA2). Mutations in brief no. 205. Online.
AB - Mutations in the human P gene lead to oculocutaneous albinism type 2 (OCA2, MIM
#203200), the most common type of albinism in humans. The P gene encodes a 110
kDa protein that is associated with melonosomal membranes and contains 12
potential membrane spanning domains. The specific function of the P protein is
currently unknown. We report 7 new mutations in the P gene associated with OCA2.
This includes 6 missense mutations (S86R, C112F, A368V, T592I, A724P and A787V)
and one frameshift mutation (1047del7). We also report 8 polymorphisms including
one amino acid substitution, D/A257. We and others have found many polymorphisms
of the P gene in the coding region, several of which result in amino acid
substitutions, making molecular diagnosis problematic. In contrast to this is the
tyrosinase gene associated with OCA1, with a limited number of polymorphic
variations in the coding region. There is also no apparent clustering of P gene
missense mutations in contrast to the clustering observed by the tyrosinase gene
missense mutations that define functional domains of the protein. Further
mutational analysis is needed to help define the critical functional domains of
the P protein and to allow a definitive diagnosis of OCA2.
PMID- 10671068
TI - Twelve novel RB1 gene mutations in patients with hereditary retinoblastoma.
Mutations in brief no. 206. Online.
AB - Hereditary predisposition to retinoblastoma is caused by germline mutations in
the RB1 gene. Mutation analysis in this gene is important because knowledge of
the causative mutation is often required for accurate risk prediction in
relatives. We have performed RB1 gene mutation analysis in 45 patients with
hereditary retinoblastoma. Screening by heteroduplex and SSCP analysis resulted
in the identification of small mutations in 28 (62%) patients. Recurrent
mutations, mostly CpG-transitions, were found in 16 patients. Two patients with
isolated bilateral retinoblastoma showed missense mutations, S567L and C712R,
which have previously been reported in a patient with bilateral tumors and in a
family with low penetrance, respectively. Twelve of the mutations identified here
have not been reported to date. These include a novel missense mutation, L662P,
which was identified in two bilaterally affected siblings and their mother with
unilateral retinoma.
PMID- 10671069
TI - Proceedings from the XI Conference of Polish Association of Neuropathologists,
Part I: Tumors of the Nervous System. Warszawa, May 13-15, 1999.
PMID- 10671070
TI - The efficacy and effectiveness of a primary preventive dental programme in non
fluoridated areas of Victoria, Australia.
PMID- 10671071
TI - Survival after cardiac arrest outside hospital.
PMID- 10671072
TI - Exercise four hour redistribution thallium-201 SPECT and exercise induced ST
segment elevation in detecting viable myocardium in patients with acute MI.
PMID- 10671073
TI - Quality of life four years after myocardial infarction: short form 36 scores
compared with a normal population.
PMID- 10671074
TI - Exercise testing, symptoms, and clinical outcome in aortic stenosis.
PMID- 10671075
TI - Value of echocardiography in predicting long term outcome after heart
transplantation.
PMID- 10671076
TI - Good outcomes from cardiac surgery in the over 70s.
PMID- 10671077
TI - Seeing what Alzheimer saw--with magnetic resonance microscopy.
PMID- 10671078
TI - Statins: lower lipids and better bones?
PMID- 10671079
TI - China's first international HIV vaccine meeting: the war of the roses.
PMID- 10671080
TI - Embedded corneal foreign body in a child? Try a chalazion currette.
PMID- 10671081
TI - Cytomegalovirus retinitis in AIDS patients: 1999 update.
PMID- 10671082
TI - Bioengineering vs mechanical engineering for cardiovascular surgery in the next
century.
PMID- 10671084
TI - Report of the 25th Annual Meeting of the European Strabismological Association.
Jerusalem, Israel, September 26-29, 1999.
PMID- 10671083
TI - Venous thrombosis in traumatic brain injury.
PMID- 10671085
TI - Report of the Annual Meeting of the Gunter K. von Noorden Visiting Professorship
in Ophthalmology. Houston, Texas, September 16-17, 1999.
PMID- 10671086
TI - Report of the Annual Meeting of the Texas Society for Pediatric Ophthalmology.
Houston, Texas, September 18, 1999.
PMID- 10671087
TI - Asp 280 residue is important in the activity of the Escherichia coli leader
peptidase.
PMID- 10671088
TI - Embryonic Stem Cells as Developmental Model in vitro. Preface.
PMID- 10671090
TI - Planimetric models to evaluate the pennate muscle force length characteristics.
PMID- 10671089
TI - Conjugate vaccines.
PMID- 10671091
TI - Planimetric models to evaluate the pennate muscle force length characteristics.
PMID- 10671092
TI - The worst of both worlds: poverty and politics in the Balkans.
PMID- 10671093
TI - Defending JCAHO standards.
PMID- 10671094
TI - Recent advances in genetic epidemiology. Special issue in honor of Professor
Newton E. Morton's 70th birthday.
PMID- 10671095
TI - Eighth International Congress of Pediatric Dermatology, Paris, France, 20 May
1998.
PMID- 10671096
TI - Alopecia areata totalis/universalis and systemic corticosteroids.
PMID- 10671097
TI - Pemphigus vulgaris associated with systemic lupus erythematosus.
PMID- 10671098
TI - Tinea versicolor mimicking pityriasis rotunda.
PMID- 10671099
TI - Cutaneous leishmaniasis in Aydin, Turkey.
PMID- 10671100
TI - Lichenoid drug eruption due to cyanamide.
PMID- 10671101
TI - Aplasia cutis congenita of the scalp associated with meningoencephalocele and
situs inversus.
PMID- 10671102
TI - Liesegang rings in a giant proliferating trichilemmal tumor.
PMID- 10671103
TI - Phenelzine as adjuvant treatment for Behcet's disease?
PMID- 10671104
TI - Cutaneous side-effects caused by Tegafur.
PMID- 10671105
TI - Mycosis fungoides; evolution towards large-cell lymphoma.
PMID- 10671106
TI - Importance of OMT cannot be overemphasized.
PMID- 10671107
TI - Take the time to teach to ensure the legacy and future of our profession.
PMID- 10671108
TI - Welcome to our future.
PMID- 10671109
TI - Dietitians face the challenge of food allergies.
PMID- 10671110
TI - Staying on track: the benefits of exercise combined with healthful eating.
PMID- 10671111
TI - Role of closed mitral commissurotomy for mitral restenosis.
AB - Out of 1184 consecutive cases of rheumatic mitral stenosis treated surgically by
closed mitral commissurotomy (CMC) at NRS Medical College and Hospital, Calcutta,
20 (1.68%) were mitral valve restenosis. Twelve cases (60%) were females, The
median age was 32 years. Duration between the first operation and reappearance of
symptoms varied with a mean of 8 years. The previous operations were digital
dilatation and instrumental dilatation in 6 and 14 cases respectively. History of
thromboembolism was present in 4 cases. On echocardiography, calcification of the
mitral valve was present in 2 cases, left atrial clot in 4 cases, associated mild
to moderate mitral regurgitation in 6 cases and mild aortic regurgitation in 4
cases. All cases presented with New York Heart Association (NYHA) III and IV
symptoms. Critical stenosis (mitral valve orifice less than 0.5 cm2) was present
in 12 cases. Re-do CMC was undertaken in all cases with Tubb's dilator. Median
operating time was 2.5 hours. Satisfactory split was achieved in 13 cases. One
patient died during surgery. Four cases having less than satisfactory split were
asymptomatic on follow-up. In one case no split was possible and in another,
gross mitral regurgitation was noted postoperatively. These 2 cases had to
undergo open heart surgery. It is concluded that re-do CMC is a feasible and
suitable alternative in mitral restenosis even in the presence of complications.
PMID- 10671112
TI - Proceedings of the 8th International Symposium on Platinum and Other Metal
Coordination Compounds in Cancer Chemotherapy. Oxford, United Kingdom, 28-31
March 1999.
PMID- 10671113
TI - Postictal psychosis related regional cerebral hyperfusion.
PMID- 10671114
TI - Oncofetal matrix glycoproteins in cerebral arteriovenous malformations and
neighbouring vessels.
PMID- 10671115
TI - Hashimoto's encephalopathy presenting as "myxodematous madness".
PMID- 10671116
TI - Alien hand sign in Creutzfeldt-Jakob disease.
PMID- 10671117
TI - Recurrent peripheral neuropathy in a girl with celiac disease.
PMID- 10671118
TI - Frontal release signs in older people with peripheral vascular disease.
PMID- 10671119
TI - Factitious clock drawing adn constructional apraxia.
PMID- 10671120
TI - Anosognosia and mania associated with right thalamic haemorrhage.
PMID- 10671121
TI - Epileptic cardiac asystole.
PMID- 10671122
TI - Respiratory insufficiency in a patient with hereditary neuropathy with liability
to pressure palsy.
PMID- 10671123
TI - Spinal accessory neuropathy and internal jugular thrombosis after carotid
endarterectomy.
PMID- 10671124
TI - Ischaemic stroke in a sportsman who consumed MaHuang extract and creatine
monohydrate for body building.
PMID- 10671125
TI - Petroclival meningioma as a cause of ipsilateral cervicofacial dyskinesis.
PMID- 10671126
TI - Acute multifocal cerebral white matter lesions during transfer factor therapy.
PMID- 10671127
TI - Fahr's disease and Asperger's syndrome in a patient with primary
hypoparathyroidism.
PMID- 10671128
TI - Hypertrophic atlantoaxial ligaments: an unusual cause of compression of the upper
spinal cord.
PMID- 10671129
TI - Selective hemihypaesthesia due to tentorial coup injury against dorsolateral
midbrain: potential cause of sensory impairment after closed head injury.
PMID- 10671130
TI - Early diagnosis of subependymal giant cell astrocytoma in children with tuberous
sclerosis.
PMID- 10671131
TI - Toluene induced postural tremor.
PMID- 10671132
TI - Atypical form of amyotrophic lateral sclerosis: a new term to define a previously
well known form of ALS.
PMID- 10671133
TI - Isolated dysarthria.
PMID- 10671134
TI - Motor cortical excitability in Huntington's disease.
PMID- 10671135
TI - Critical closing pressure: a valid concept?
PMID- 10671136
TI - High frequency stimulation of the subthalamic nucleus and levodopa induced
dyskinesias in Parkinson's disease.
PMID- 10671137
TI - Nitric oxide in acute ischaemic stroke.
PMID- 10671138
TI - Historical note. Arnold Chiari, or "Cruvilhier Cleland Chiari" malformation.
PMID- 10671139
TI - The consultation in art.
PMID- 10671140
TI - More SANE program listings.
PMID- 10671141
TI - [Antineoplastic effect of novel agents, UCN-01 on human tumor cells transplanted
in nude mice].
PMID- 10671142
TI - Millennium bugs. AIDS in Africa threatens the United States. It should not act
accordingly.
PMID- 10671143
TI - Internet fervour hits genomics.
PMID- 10671144
TI - Lobbyists anticipate more money for all.
PMID- 10671145
TI - Should private enterprise take over.
PMID- 10671146
TI - [Is it possible to spare eyebrows while undergoing radiotherapy?].
PMID- 10671147
TI - [Renal tubular acidosis and deafness due to mutation in the gene encoding the B1
subunit of H+ATPase].
PMID- 10671148
TI - [Role and physiologic importance of megalin in the internalization of vitamin D
by endocytosis at the luminal pole of the proximal convoluted tubule].
PMID- 10671149
TI - [Does angiotensin II increase or decrease prostaglandin synthesis ?].
PMID- 10671150
TI - [ERA-EDTA Symposium on Renal Ischemia. Rimini, 6-9 June 1998].
PMID- 10671151
TI - Costs of otitis media?
PMID- 10671152
TI - Evaluation of vaginal infections in adolescent women: can it be done without a
speculum?
PMID- 10671153
TI - Cancer in children: is the sample biased.
PMID- 10671154
TI - Antibiotic use and parental home otoscopy.
PMID- 10671155
TI - Health care for children in Afghanistan.
PMID- 10671156
TI - Agricultural research. Windfall breeds fresh but vulnerable crop of grants.
PMID- 10671157
TI - E.U. grabs food safety by the horns.
PMID- 10671158
TI - Embryos attacked by mom's natural defenses.
PMID- 10671159
TI - How rotavirus causes diarrhea.
PMID- 10671160
TI - Reaping the plant gene harvest.
PMID- 10671162
TI - Taxonomy. Researchers cash in on personalized species names.
PMID- 10671161
TI - Meeting. Society for Integrative and Comparative Biology. Integrating the many
aspects of biology.
PMID- 10671163
TI - Science in response to basic human needs.
PMID- 10671164
TI - Childhood cancer.
PMID- 10671165
TI - Misallocation of CDC funds.
PMID- 10671166
TI - Societal responsibilities.
PMID- 10671167
TI - Societal responsibilities.
PMID- 10671168
TI - Societal responsibilities.
PMID- 10671169
TI - Societal responsibilities.
PMID- 10671170
TI - Considering manure and carbon sequestration.
PMID- 10671171
TI - Policy forum: genetic technologies. Monitoring and labeling for genetically
modified products.
PMID- 10671172
TI - Perspectives: plant biology. Some like it hot.
PMID- 10671173
TI - Perspectives: transcription. A tail of histone acetylation and DNA recombination.
PMID- 10671174
TI - Perspectives: protein synthesis. Unraveling the riddle of ProCys tRNA synthetase.
PMID- 10671175
TI - Techview: molecular biology. Bead-based fiber-optic arrays.
PMID- 10671176
TI - Discovery of the antidepressant and anti-emetic efficacy of substance P receptor
(NK1) antagonists.
AB - The development of small-molecule antagonists of the substance P (SP)-preferring
tachykinin NK1 receptor during the past decade represents an important
opportunity to exploit these molecules as novel therapeutic agents. On the basis
of its anatomical localization and function, SP has been implicated in diverse
pathophysiologies; of these, diseases of the CNS have been examined in the
greatest detail. Although SP is best known as a pain neurotransmitter, it also
controls vomiting and various behavioural, neurochemical and cardiovascular
responses to stress. Recent clinical trials have confirmed the efficacy of NK1
receptor antagonists to alleviate depression and emesis but, surprisingly, not
pain. Thus, multiple clinical trials, targeted to appropriate patient
populations, are necessary to define the therapeutic potential of novel
neurotransmitter ligands.
PMID- 10671177
TI - [Torsion of the small intestine caused by gangrenous Meckel's diverticulum].
PMID- 10671178
TI - [The 75th anniversary of the St. Petersburg Scientific Society of
Physiotherapists].
PMID- 10671179
TI - [Review of the materials of the 7th European Conference on Nutrition].
PMID- 10671180
TI - What topics will Acta cover in the new millenium?
PMID- 10671181
TI - Microwave emissions from police radar.
AB - This study evaluated police officers' exposures to microwaves emitted by traffic
radar units. Exposure measurements were taken at approximated ocular and
testicular levels of officers seated in patrol vehicles. Comparisons were made of
the radar manufacturers' published maximum power density specifications and
actual measured power densities taken at the antenna faces of those units. Four
speed-enforcement agencies and one transportation research institute provided 54
radar units for evaluation; 17 different models, encompassing 4 frequency bands
and 3 antenna configurations, were included. Four of the 986 measurements taken
exceeded the 5 mW/cm2 limit accepted by the International Radiation Protection
Association and the National Council on Radiation Protection and Measurement,
though none exceeded the American Conference of Governmental Industrial
Hygienists, American National Standards Institute, Institute of Electrical and
Electronic Engineers, or Occupational Safety and Health Administration standard
of 10 mW/cm2. The four high measurements were maximum power density readings
taken directly in front of the radar. Of the 812 measurements taken at the
officers' seated ocular and testicular positions, none exceeded 0.04 mW/cm2; the
highest of these (0.034 mW/cm2) was less than 1% of the most conservative current
safety standards. High exposures in the limited region directly in front of the
radar aperture are easily avoided with proper training. Results of this study
indicate that police officer exposure to microwave radiation is apparently
minimal. However, because of uncertainty in the medical and scientific
communities concerning nonionizing radiation, it is recommended that law
enforcement agencies implement a policy of prudent avoidance, including
purchasing units with the lowest published maximum power densities, purchasing
dash/rear deck-mounted units with antennae mounted outside the patrol vehicle,
and training police officers to use the "stand-by" mode when not actually using
radar.
PMID- 10671182
TI - Highly Unsaturated Fatty Acids in Nutrition and Disease Prevention. Proceedings
of an international conference. Barcelona, Spain, November 4-6, 1996.
PMID- 10671183
TI - Critical issues in academic orthodontics.
PMID- 10671184
TI - More on indirect bonding.
PMID- 10671185
TI - [Italian Bone Marrow Donor Registry].
PMID- 10671186
TI - Reductive dechlorination of tetrachloroethene to ethene by a two-component enzyme
pathway.
AB - Two membrane-bound, reductive dehalogenases that constitute a novel pathway for
complete dechlorination of tetrachloroethene (perchloroethylene [PCE]) to ethene
were partially purified from an anaerobic microbial enrichment culture containing
Dehalococcoides ethenogenes 195. When titanium (III) citrate and methyl viologen
were used as reductants, PCE-reductive dehalogenase (PCE-RDase) (51 kDa)
dechlorinated PCE to trichloroethene (TCE) at a rate of 20 micromol/min/mg of
protein. TCE-reductive dehalogenase (TCE-RDase) (61 kDa) dechlorinated TCE to
ethene. TCE, cis-1,2-dichloroethene, and 1,1-dichloroethene were dechlorinated at
similar rates, 8 to 12 micromol/min/mg of protein. Vinyl chloride and trans-1,2
dichloroethene were degraded at rates which were approximately 2 orders of
magnitude lower. The light-reversible inhibition of TCE-RDase by iodopropane and
the light-reversible inhibition of PCE-RDase by iodoethane suggest that both of
these dehalogenases contain Co(I) corrinoid cofactors. Isolation and
characterization of these novel bacterial enzymes provided further insight into
the catalytic mechanisms of biological reductive dehalogenation.
PMID- 10671187
TI - Physical training improves flow-mediated dilation in patients with the
polymetabolic syndrome.
AB - Endothelial dysfunction that can be detected as impaired flow-mediated dilation
by ultrasonography is an early event in atherogenesis and has been demonstrated
in healthy subjects with risk factors for atherosclerosis many years before the
appearance of atheromatous plaques. We examined the influence of physical
training on flow-mediated dilation in patients with the polymetabolic syndrome.
Twenty-nine asymptomatic men aged 40 to 60 years with the polymetabolic syndrome
were randomly divided between the control group and the training group, which
trained 3 times a week for 12 weeks. On high-resolution ultrasound images, the
diameter of the brachial artery was measured at rest, after reactive hyperemia
(causing flow-mediated, endothelium-dependent dilation), and after sublingual
glyceryltrinitrate (causing endothelium-independent vasodilation) in all subjects
before and after the training period. The training program induced an increase of
18% in physical fitness. Flow-mediated dilation increased from 5.3+/-2.8% to
7.3+/-2.7% (P<0. 05). There was no change in body mass index, blood pressure,
insulin resistance, lipids, and big endothelin-1 in either group. Flow-mediated
dilation measured before training was negatively correlated with resting heart
rate, waist-to-hip ratio, and insulin resistance. Resting heart rate emerged as
the only independent determinant, which explained 22% of the variation in flow
mediated dilation. In conclusion, our findings suggest that a 3-month physical
training program, which improved maximal exercise capacity, enhances flow
mediated dilation in patients with the polymetabolic syndrome.
PMID- 10671188
TI - Glucocorticoid production in the murine thymus.
AB - Glucocorticoid hormones are known to act as important modulatory factors in the
development of autoimmune diseases, and to play an important role in thymic T
cell selection. There seems to be a finely balanced equilibrium between the
apoptosis-inducing effects of glucocorticoid and T cell receptor ligand binding.
Here we are investigating whether glucocorticoid-induced T cell apoptosis is
mainly dependent on circulating glucocorticoid levels or if the thymus itself is
able to produce glucocorticoids. To this end, we attempted to demonstrate enzyme
activities of the whole set of steroidogenic enzymes for the synthesis of
glucocorticoids in murine thymic tissue. We isolated steroidogenic organelles
from thymic tissue, incubated these with radioactive (precursor) steroids in
vitro, and visualized the resulting products by thin-layer chromatography. Our
results show that the thymus possesses all enzymes and cofactors required for
glucocorticoid production. However, an intact thymic architecture is necessary
for glucocorticoid production, since 11beta-hydroxylase was not detected in
irradiated thymi or in a thymic epithelial cell line. The results of these
experiments show that the whole glucocorticoid metabolism takes place within the
thymus. This finding provides the biochemical basis for the in situ effects of
glucocorticoid hormones on thymocyte development and selection.
PMID- 10671189
TI - Endogenous IL-12 synthesis is not required to prevent hyperexpression of type 2
cytokine and antibody responses.
AB - Endogenous IL-12 production is hypothesized to play an essential role preventing
spontaneous expression of type 2 responses, acting as a natural inhibitor
limiting development of immediate hypersensitivity. Here, IL-12-deficient p35(- /
-) and p40(- / -) mice were used to examine the role of endogenous IL-12 and p40
homodimer during in vivo development of exogenous antigen-driven responses. In
the absence of deliberate immunization, IL-12-deficient mice exhibited greatly
reduced serum IgG2a but IgG1 / IgE levels no higher than controls. Immunization
to elicit polarized ovalbumin-specific type 1 or type 2 dominant responses, or
using Trichinella spiralis extract in the absence of adjuvants, led to IFN-gamma
production of approximately 10 % of C57BL / 6 controls yet the kinetics and
intensity of primary and secondary type 2 cytokine (IL-4, IL-5, IL-13) and
antibody (IgG1, IgE) responses, as well as functional IL-12 receptor expression,
were consistently unaltered. Thus, while IL-12 provides an important positive
signal for Th1 development, antigen exposure in its absence does not lead to
generalized enhancement of type 2 cytokine or antibody responses. The data argue
that endogenous IL-12 production is not required as a constitutive negative
regulator limiting induction or expression of type 2 effector responses.
PMID- 10671190
TI - Genetic dissection of B cell traits in New Zealand black mice. The expanded
population of B cells expressing up-regulated costimulatory molecules shows
linkage to Nba2.
AB - B cell abnormalities are a prominent feature of the immunologic derangement in
NZB and NZB / W mice. We recently demonstrated that these mice have an increased
proportion of splenic B cells expressing B7.1 and elevated levels of B7.2 and
ICAM-1 that possess the characteristics of marginal zone B cells (CD23(low / -)
CD5(-) CD44(hi) CD24(hi) IgD(- / low) IgM(hi)) and are found as early as 4 - 6
weeks of age. These findings suggest that activated B cells in NZB and NZB / W
mice could serve a costimulatory function leading to activation of autoreactive T
cells. However, it remains unclear whether there is any association between B
abnormalities and nephritis in these mice. Here we have used genetic mapping
techniques to address this issue. We show that increases in the proportion of B
cells expressing costimulatory molecules, serum IgM levels, the number of IgM
ELISpots, and IgG anti-single-stranded (ss) DNA antibody production, are
significantly associated with a chromosomal region that overlaps with Nba2, a
genetic locus previously linked to nephritis. Based on these findings we propose
that immune mechanisms leading to polyclonal B cell activation and up-regulation
of costimulatory molecules in these mice play a central role in the loss of
tolerance that leads to production of pathogenic autoantibodies.
PMID- 10671191
TI - CD3 activation induces concentrative nucleoside transport in human T lymphocytes.
AB - Nucleoside transport, assessed by measuring deoxythymidine influx, was
investigated in normal and CD3-activated human peripheral blood mononuclear cells
(PBMC) and in the CEM cell line. On both cell types, an equilibrative
nitrobenzylmercaptopurine (NBMPR)-sensitive (es) transporter encoded by the
hENT(1) gene was identified on resting cells, although the expression level was
about 20-fold higher on CEM cells than on resting peripheral T lymphocytes. After
stimulation with anti-CD3, a strong increase of nucleoside transport was observed
in PBMC accompanied by a mild augmentation of NBMPR binding sites on the cell
surface. Most of this improved transport capacity was NBMPR insensitive,
dependent on Na(+) concentration in the medium, and displayed the features of a
concentrative process. Similar results were obtained with CEM cells despite their
high basal es level, indicating that the induction of a concentrative process for
nucleoside salvage is a specific metabolic response associated with antigen
driven stimulation. In CEM cells, this induction did not affect the growth rate.
The concentrative transporter involved does not correspond to any of those which
have been cloned so far. Molecular characterization of this transporter should
provide a new marker of antigen stimulation and will allow to define whether
activation of the corresponding gene is under the control of TCR-CD3-induced
second messengers.
PMID- 10671192
TI - Different doses of agonistic ligand drive the maturation of functional CD4 and
CD8 T cells from immature precursors.
AB - MHC molecules are normally required for the development of thymocytes from the
CD4(+)CD8(+) double-positive to the CD4 or CD8 single-positive stage. Here we
show that mitogenic plant lectins can substitute for MHC molecules in driving the
differentiation of phenotypically and functionally mature CD4 as well as CD8 T
cells. Interestingly, lectin dosage determines whether CD4 or CD8 cells are
generated, indicating that variation of cumulative signal strength (not
necessarily signal quality) can result in an apparent switching of lineage
preference. Thymocyte perception of differentiation-inducing signals is modulated
by the cellular context, since stimuli that yield CD8 cells in the context of the
thymic microenvironment fail to do so in suspension culture and generate CD4
progeny instead. Finally, we show that lectin-generated single-positive
thymocytes retain the ability to respond to the ligands initially used to drive
their differentiation. Our results call into question generalizations and
predictions made from other experimental systems and reveal that thymocyte
selection is considerably more flexible than had been anticipated.
PMID- 10671193
TI - IL-10 deficiency prevents IL-5 overproduction and eosinophilic inflammation in a
murine model of asthma-like reaction.
AB - Eosinophilic inflammation and bronchial mucus secretion are among the
characteristic pathological changes in asthmatic reaction, which is mediated by
Th2 type responses. Although it belongs to Th2 cytokines especially in the mouse,
IL-10 is often considered an inhibitory cytokine for both Th1 and Th2 cells. In
the present study, using a murine asthma model induced by ovalbumin (OVA), we
demonstrated that endogenous IL-10 is critical for the development of asthma-like
responses. Specifically, in comparison with wild-type controls, IL-10 gene
knockout (KO) mice showed significantly reduced IL-5 production, eosinophilic
inflammation and mucus production without notable changes in IL-4 and IgE
responses following i. p. sensitization and subsequent intranasal challenge with
OVA. In addition, Th1-related cytokine (IFN-gamma and IL-12) production in IL-10
KO mice was significantly higher than that in wild-type mice. The results suggest
that endogenous IL-10 plays an important role in promoting pulmonary eosinophilic
inflammatory reaction and mucus production during asthmatic reaction. The data
also argue that IL-10 may be more influential in the development of IL-5
producing Th2 cells which differ from typical Th2 cells producing both IL-4 and
IL-5.
PMID- 10671194
TI - Co-stimulation of antigen-specific CD4 T cells by 4-1BB ligand.
AB - 4-1BB is a member of the TNF receptor family predominantly expressed on activated
T cells, and binds an inducible ligand found on B cells, macrophages and
dendritic cells. Whereas ligation of 4-1BB has been shown to enhance response of
purified CD8 T cells to mitogens, and to augment NK activity and generation of
cytotoxic T lymphocytes in vivo, there are little direct data on 4-1BB action
during CD4 responses. Using pigeon cytochrome c-presenting fibroblast antigen
presenting cells transfected with 4-1BB ligand (4-1BBL), we show that engaging 4
1BB on naive CD4 cells promotes proliferation, cell cycle progression and IL-2
secretion, and suppresses cell death, all to a similar extent as B7-1 engagement
of CD28. In addition, 4-1BBL synergizes with B7 and ICAM to enhance naive CD4
proliferation when antigen is limiting. 4-1BBL alone, and to a greater extent
with B7, also augmented IL-2 secretion resting antigen-experienced CD4 cells, as
typified by T helper clones, whereas short-term effector cells showed similar
levels of proliferation and cytokine secretion regardless of whether 4-1BB was
engaged. A major role in augmenting IFN-gamma, IL-4 or IL-5 was not demonstrated.
Blocking studies with activated B cells presenting antigen showed that 4-1BB
participates in promoting IL-2 production by resting CD4 cells, confirming that 4
1BBL can play a role in antigen-specific CD4 T cell responses.
PMID- 10671195
TI - Down-regulation of antigen-specific antibody production by TCR antagonist
peptides in vivo.
AB - The efficacy of TCR antagonist peptides in inhibition of antigen-specific
antibody production and T cell responses in vivo was evaluated. Among amino acid
substituted analogs of a peptide corresponding to residues 119 - 133 of bovine
beta-lactoglobulin (p119 - 133), pR124Q and pD129S, prepared by substitution of
Gln and Ser for Arg(124) and Asp(129), respectively, have been shown to display
TCR antagonist activity for three out of four distinct p119 - 133-specific T cell
clones and for polyclonal T cells derived from p119 - 133-immunized C57BL / 6
mice. Both pD129S and pR124Q inhibited in vivo priming and subsequent activation
of T cells by p119 - 133 when co-injected with p119 - 133 into mice, as shown by
the decreased proliferation of T cells in response to p119-133 in vitro. pD129S
significantly inhibited production of anti-p119 - 113 antibodies of IgG1, IgG2b
and IgE isotype in vivo when co-injected into mice together with p119 - 133 at
the time of the first immunization. However, pR124Q was totally ineffective in
inhibition of the antibody responses. Anti-p119 - 133 antibodies from p119 - 133
immunized mice could bind to pR124Q but not to pD129S, suggesting that the
difference in cross-reactivity is responsible for the different effect of these
two peptides on specific antibody production. Our findings demonstrate that a
single TCR antagonist peptide can inhibit antigen-specific polyclonal antibody
production when this antagonist peptide does not cross-react with the antibody
elicited in response to an antigenic peptide.
PMID- 10671196
TI - Direct anti-inflammatory effect of a bacterial virulence factor: IL-10-dependent
suppression of IL-12 production by filamentous hemagglutinin from Bordetella
pertussis.
AB - IL-12 plays a critical role in protective immunity against intracellular
pathogens by promoting the development of Th1 cells. Here we demonstrate that
filamentous hemagglutinin (FHA), a virulence factor of Bordetella pertussis, is
capable of suppressing IL-12 production by macrophages. FHA inhibited IL-12
secretion by a macrophage cell line or ex vivo alveolar macrophages in response
to Escherichia coli or B. pertussis lipopolysaccharide (LPS) and IFN-gamma.
Antibodies to FHA or denaturation of FHA abrogated the inhibitory effect.
Injection of mice with FHA suppressed IL-12 and IFN-gamma levels in the serum in
response to i. v. injection of LPS in a model of septic shock. The suppressive
effect of FHA was specific for IL-12, since the production of TNF-alpha, IL-6 and
IL-10 was not suppressed, and production of IL-6 and IL-10 was up-regulated.
Antibody blocking studies revealed that the inhibitory effect of FHA on IL-12
production was dependent on IL-10. Since FHA is secreted at high levels and local
T cell responses are suppressed during B. pertussis infection, the findings
suggest that FHA may be a critical virulence factor in facilitating pathogen
persistence in the respiratory tract by suppressing or delaying the development
of cell-mediated immunity.
PMID- 10671197
TI - A subunit vaccine candidate region of the Entamoeba histolytica galactose
adherence lectin promotes interleukin-12 gene transcription and protein
production in human macrophages.
AB - The cysteine-rich region of the 170-kDa subunit galactose-adherence lectin (Gal
lectin) of Entamoeba histolytica is a subunit vaccine candidate and a protective
antigen in the gerbil model of amebiasis. Macrophage-mediated immunity is
important for protection against E. histolytica and is activated by Th1
cytokines. As Th1 differentiation is promoted by IL-12, we investigated what
portion of the Gal-lectin could stimulate IL-12 in human THP-1 macrophages.
Native Gal-lactin stimulated IL-12 p40 / p35 mRNA expression in a dose- and time
dependent manner as measured by reverse transcriptase-PCR. Human immune serum and
Gal-lectin mAb inhibition studies identified amino acids (aa) 596 - 998 as
immunogenic and containing the IL-12 inducing domain. IFN-gamma priming augmented
Gal-lectin-induced IL-12 mRNA expression independent of TNF-alpha and IL-1beta,
and was required for IL-12 p70 protein production from macrophages and human
peripheral blood mononuclear cells. Gal-lectin plus IFN-gamma stimulated IL-12
p40 and p35 gene transcription with stable mRNA transcripts and a differential
requirement for protein synthesis. These results suggest that aa 596 - 998 of the
Gal-lectin can confer Th1-mediated protection against amebiasis through IL-12
induction.
PMID- 10671198
TI - Pristane-induced arthritis in mice selected for maximal or minimal acute
inflammatory reaction.
AB - The role of inflammatory and specific immune responses in pristane-induced
arthritis (PIA) was investigated in mouse lines produced by bi-directional
selective breedings for maximal (AIRmax) or minimal (AIRmin) acute inflammatory
reaction, comparing the outcome of PIA and the humoral and cellular response to
hsp65. Symptoms of arthritis were detected in 50 % AIRmax mice 120 days after
pristane injection, reaching a maximal incidence of 65 %, whereas only 7 % of
AIRmin mice developed arthritis within an observation period of 200 days. The
production of IgG antibody against hsp65 was found to be similar on both lines,
although the IgG1 isotype was predominant in AIRmax, and IgG2a in AIRmin line. In
vitro T cell proliferation to hsp65 was similar in the two lines, however,
ELISPOT assays carried out soon after pristane treatment, demonstrated higher
numbers of IL-6-, TNF-alpha- and IL-4-secreting cells in the spleen of AIRmax
than in AIRmin mice, while higher numbers of IFN-gamma-producing cells were found
in AIRmin mice. These results suggest a major participation of acute inflammatory
mechanisms in the susceptibility to PIA. The genetic background which determines
high or low AIR favors a Th2-like response in susceptible AIRmax and Th1-like
response in resistant AIRmin mice at the initial phase of arthritis induction.
PMID- 10671199
TI - Dichotomic effects of IFN-gamma on the development of systemic lupus
erythematosus-like syndrome in MRL-lpr / lpr mice.
AB - Systemic lupus erythematosus (SLE)-prone female MRL-lpr / lpr (MRL-lpr) mice were
treated with mouse or rat IFN-gamma under different experimental conditions, both
prophylactically in 6- to 8 week-old animals and therapeutically in 12- to 18
week-old SLE-affected mice. It was found that IFN-gamma heterogeneously modulated
the course of the disease in MRL-lpr mice. When administered prophylactically,
IFN-gamma favorably modulated the histological, serological and clinical signs of
the disease. Relative to untreated or PBS-treated control animals, the MRL-lpr
mice which received IFN gamma were virtually free of inflammatory infiltration of
the kidneys and the lungs, had lower levels of azotemia with reduction of both
circulating IgG1, IgG2a and IgG3 and anti-double strand (ds) and single strand
(ss) DNA antibodies, milder skin vasculitis, significantly reduced enlargement of
their lymph nodes and lower weight of the spleens. IFN-gamma also lowered the
rate of mortality of MRL-lpr mice. In contrast to these findings, therapeutically
administered IFN-gamma worsened the course of the disease in MRL-lpr mice, which
exhibited increased proteinuria, higher levels of IgG2a and IgG3 and anti-ds and
ss DNA antibodies, more aggressive nephritis and died at an earlier age than PBS
treated control mice. The dichotomic effect of IFN-gamma on disease manifestation
in MRL-lpr mice offers new insights into the complex role of this cytokine in the
regulation of systemic autoimmunity such as SLE.
PMID- 10671200
TI - Multiple cross-reactive self-ligands for Borrelia burgdorferi-specific HLA-DR4
restricted T cells.
AB - T cell recognition of self antigens is a key event in the pathogenesis of
autoimmune diseases. To date, the initial events that trigger autoreactive T
cells are unknown. The "molecular mimicry" hypothesis predicts that during an
infection T cells that recognize both a microbial antigen and a related self
peptide become activated and cause autoimmune disease. We have systematically
examined the recognition of self antigens by HLA-DR4-restricted T cells specific
for peptides of the outer surface protein A (OspA) of Borrelia burgdorferi, the
etiological agent of Lyme disease. We used the peptide spot synthesis technique
for complete peptide substitution analyses of two immunodominant OspA epitopes.
Each amino acid residue of the epitopes was substituted with all 20 naturally
occurring amino acids and the altered peptides were tested for recognition by a
panel of OspA-specific T cells. The binding motifs (supertopes) revealed by these
analyses were used to screen public databases for matching human or murine
peptides. Several hundred peptides were identified by this search and
synthesized. Of these, 28 were recognized by OspA-specific T cells. Thus, T cell
cross-reactivity is a common phenomenon and the existence of cross-reactive
epitopes alone does not imply molecular mimicry-mediated pathology and
autoimmunity.
PMID- 10671201
TI - The BOB.1 / OBF.1 co-activator is essential for octamer-dependent transcription
in B cells.
AB - The BOB.1 / OBF.1 / OCA-B protein (henceforth designated as BOB.1 / OBF.1) is a B
cell-specific co-activator of the Oct1 and Oct2 transcription factors. It is
involved in mediating the transcriptional activity of these proteins.
Surprisingly, animals deficient for BOB.1 / OBF.1 showed normal expression of
genes that contain an octamer motif in their regulatory regions. Here we have
addressed the role of BOB.1 / OBF.1 for octamer-dependent transcription. We show
that promoters exclusively dependent on functional octamer motifs are completely
inactive in BOB.1 / OBF. 1-deficient B cells. The lack of activity is a direct
consequence of lack of the co-activator. To show this, a hormone-regulated
conditional allele of BOB.1 / OBF.1 was introduced into the BOB.1 / OBF.1
deficient B cells. This resulted in the hormone-dependent transcriptional
activity of octamer-dependent reporters in these cells. The BOB.1 / OBF.1
requirement for octamer promoter function was also observed when an authentic
immunoglobulin kappa-promoter was assayed. BOB.1 / OBF.1 dependence could not be
overcome by including the strong enhancer element from the immunoglobulin heavy
chain gene. Induction of pre-B cells with lipopolysaccharide led to increased
Oct2 levels but did not significantly increase octamer-dependent transcription in
BOB.1 / OBF.1-deficient B cells. Thus, these results demonstrate that BOB.1 /
OBF.1 itself is a non-redundant protein in B cells and absolutely required for
octamer-dependent transcriptional activity.
PMID- 10671202
TI - Elevated type 1, diminished type 2 cytokines and impaired antibody response are
associated with hepatotoxicity and mortalities during Schistosoma mansoni
infection of CD4-depleted mice.
AB - During murine Schistosoma mansoni infections parasite eggs evoke a type 2
cytokine-dependent and CD4(+) T cell-mediated granulomatous response in the
liver. In this study CD4(+) T cell-depleted CBA / Ca mice developed hepatic
steatosis and had high mortalities during early acute schistosome infection. CD4
depleted mice had smaller liver granulomas and reduced hepatic fibrosis. The
hepatocytotoxicity was characterized by microvesicular steatosis and neutrophil
infiltration. The livers of depleted mice had similar levels of apoptosis as
control infected mice but had a marked increase in lipid peroxidation indicative
of their livers being under oxidative stress. CD4-depleted mice had impaired egg
excretion and exacerbated intestinal pathology. A type 1 cytokine-dominated
response was present in infected CD4-depleted mice and relatively reduced
production of type 2 cytokines. Antibody responses to parasite antigens were also
substantially reduced. Transfer of immune serum or IgG significantly delayed
mortalities in depleted mice and prevented hepatocyte damage. Although biasing
the cytokine dichotomy to a type 1-dominated response during murine schistosome
infection is desirable with respect to certain pathological processes, i. e. it
will reduce the granulomatous inflammation and hepatic fibrosis, these effects
contribute to fatal pathology if there is reduced protective type 2 cytokines and
a defect in antibody responses.
PMID- 10671203
TI - Mouse FcgammaRII is a negative regulator of FcgammaRIII in IgG immune complex
triggered inflammation but not in autoantibody-induced hemolysis.
AB - Murine low-affinity receptors for IgG, FcgammaRII and FcgammaRIII, differ by
their distinct capacities in mediating down-regulation or activation of cellular
effector functions, respectively. In this study, antibodies detecting the mouse
Ly-17.1 / 2 alloantigen system are demonstrated to be specific for FcgammaRII
with no cross-reactivities to other FcgammaR, including FcgammaRIII. Using these
FcgammaRII-specific monoclonal antibodies (mAb), the significance of FcgammaRII
inhibition of FcgammaRIII was examined in two models of autoantibody [autoimmune
hemolytic anemia (AIHA)]- and IgG immune complex-induced (Arthus reaction)
inflammation in C57BL / 6 mice in comparison with FcgammaRII(- / -) and
FcgammaRIII(- / -) mice. Our results demonstrate that both FcgammaRIII and
FcgammaRII contributed to the binding of erythrocytes opsonized with the
pathogenic IgG1 autoreactive anti-murine red blood cell antibody 105-2H. However,
the functional blocking with anti-FcgammaRII mAb in C57BL / 6 mice and the lack
of FcgammaRII expression in FcgammaRII(- / -) mice, which both lowered the
threshold level of FcgammaRIII-triggered phagocytosis in vitro, did not results
in enhanced disease development of 105-2H mAb-induced AIHA in vivo. This was in
sharp contrast to cutaneous Arthus reaction, where FcgammaRIII-mediated
activation was inhibited by FcgammaRII. Together these results show that murine
AIHA is markedly different from other FcgammaR-dependent inflammatory diseases
where FcgammaRIII is normally counterregulated by FcgammaRII.
PMID- 10671204
TI - Human afferent lymph from normal skin contains an increased number of mainly
memory / effector CD4(+) T cells expressing activation, adhesion and co
stimulatory molecules.
AB - We investigated the T cell population in the afferent lymph and the peripheral
blood with regard to expression of activation, adhesion and co-stimulatory
molecules and cytokine profile by immunohistochemistry and flow cytometry. The
majority of the lymphoid cell population in the afferent lymph were CD4(+),
CD45RO(+) T cells expressing the alpha beta TCR. An increased percentage of the T
cells expressed activation molecules like HLA-DR, CD25, CD26, CD69 as well as
adhesion and co-stimulatory molecules like CD54, CD154 / 40 ligand. Furthermore,
T cells in the afferent lymph predominantly expressed the type 1 cytokine IFN
gamma, whereas type 2 cytokines such as IL-4, IL-5, IL-10 were not or barely
detectable. Interestingly, dendritic cells expressing IL-12 were also found in
close association with some lymphocytes, indicating that these contacts may be
important in promoting Th 1 cells. In conclusion, an increased number of mainly
CD4(+) memory / effector T cells, expressing activation, adhesion and co
stimulatory molecules migrate through the afferent skin-derived lymph in humans.
Furthermore, our data demonstrate the dominance of a type 1 cytokine profile in
these T cells and suggest that they have an important function in the immune
surveillance against pathogens or other antigens in the skin and its associated
lymphoid tissue.
PMID- 10671205
TI - Inhibition of Th1 development and treatment of chronic-relapsing experimental
allergic encephalomyelitis by a non-hypercalcemic analogue of 1,25
dihydroxyvitamin D(3).
AB - 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] inhibits production of IL-12, a
cytokine involved in the development of Th1 cells and in the pathogenesis of Th1
mediated autoimmune diseases. Here, we show that 1,25(OH)(2)D(3) and a non
hypercalcemic analogue are selective and potent inhibitors of Th1 development in
vitro and in vivo without inducing a deviation to the Th2 phenotype.
Administration of 1,25(OH)(2)D(3) or its analogue prevents chronic-relapsing
experimental allergic encephalomyelitis (CR-EAE) induced by the myelin
oligodendrocyte glycoprotein (MOG) peptide 35 - 55 (MOG(35 - 55)) in Biozzi AB /
H mice. The inhibition of EAE induction is associated with a profound reduction
of MOG(35 - 55)-specific proliferation and Th1 cell development. Importantly, the
non-hypercalcemic analogue also provides long-term protection from EAE relapses
induced by immunization with spinal cord homogenate when administered for a short
time at symptom onset or even after the first peak of disease. Neuropathological
analysis shows a reduction of inflammatory infiltrates, demyelinated areas and
axonal loss in brains and spinal cords of treated mice. These resuls indicate
that inhibition of IL-12-dependent Th1 cell development is associated with
effective treatment of CR-EAE and suggest the feasibility of an approach based on
low molecular weight inhibitors of IL-12 production in the treatment of multiple
sclerosis.
PMID- 10671206
TI - A role for MHC class I down-regulation in NK cell lysis of herpes virus-infected
cells.
AB - NK cells represent an efficient first line of defense against virus infection,
preceding the generation of adaptive T cell responses. However, the NK cell
receptors involved in the recognition of virus-infected cells remain ill defined.
We studied the in vitro response of isolated human NK cell clones to cells
infected by the herpes viruses, herpes simplex virus (HSV) and human
cytomegalovirus (HCMV). Both HSV and HCMV were found to induce NK cell
cytotoxicity by down-regulating HLA-C molecules engaged in the triggering of
killer inhibitory receptors (KIR). This conclusion was further substantiated by
the finding that expression of viral genes known to interfere with MHC class I
expression, such as the TAP inhibitor ICP47 of HSV and the MHC class I-destroying
US11 protein of HCMV, was sufficient to trigger the cytotoxicity of NK cell
clones expressing an inhibitory KIR for HLA-C. These results show for the first
time that MHC class I down-regulation could render cells infected with herpes
viruses susceptible to NK cell killing, thus demonstrating a role for KIR in the
recognition of virally infected cells.
PMID- 10671207
TI - Lactate dehydrogenase A-dependent surface expression of immature thymocyte
antigen-1: an implication for a novel trafficking function of lactate
dehydrogenase-A during T cell development.
AB - A possible involvement of lactate dehydrogenase A (LDHA) in the translocation of
a thymic differentiation antigen, immature thymocyte antigen-1 (IMT-1), from
cytoplasm to cell surface membrane during thymocyte differentiation is described.
Transfection of cDNA for LDHA, but not LDHB, into EL4 cells, which expressed IMT
1 in the cytoplasm but not on the cell surface, induced the expression of IMT-1
on the cell surface. This translocation process seemed to be dependent on the
translation of LDHA cDNA in EL4 cells, as well as the native structure of LDHA
composing of coenzyme binding domain, catalysis domain, and subunit contact
domain. Immunoprecipitation analysis revealed that LDHA could be co-precipitated
with IMT-1 from the cell surface of EL4 cells that had been transfected with LDHA
cDNA, suggesting that some of LDHA is associated with cell surface IMT-1 on the
transfectants. Flow cytometry analysis of thymocyte subpopulations showed that
some thymocytes at the CD4(-)CD8(-) double negative stage express both IMT-1 and
LDHA on their surface. These data indicate that LDHA, in addition to its function
in the metabolism in the glycolytic pathway, may have a novel function in the
expression of a cell surface antigen during T cell development.
PMID- 10671208
TI - Differential effects on T cell and NK cell development by tissue-specific
expression of H-2D(d) transgene.
AB - The effect of tissue-specific expression of the MHC class I molecule H-2D(d) on T
cell and NK cell specificity was studied in transgenic mice expressing the H
2D(d) gene under the control of the mouse metallothionein-I promoter. MTD mice
expressed high amounts of H-2D(d) in the liver, intestine and testis, but only
minute amounts in the thymus, spleen and kidney. Zinc administration resulted in
a 1.5- and 8.5-fold increase in H-2D(d) expression in the liver and the
intestine, respectively, but did not affect expression in the other organs
tested. T cell tolerance developed towards H-2D(d) in MTD mice, even in the
absence of zinc. In contrast, NK cell-mediated natural resistance against
lymphoma grafts was not seen in MTD mice, despite zinc administration. NK cells
in MTD mice also failed to develop self tolerance to H-2D(d). The lack of
functional effects did not result from inability of NK cells in MTD mice to
interact with H-2D(d), as down-regulation of Ly49A receptor expression was
observed on liver NK cells in MTD mice. Our data reveal a difference between T
cells and NK cells in their requirements for MHC class I molecules in specificity
development.
PMID- 10671209
TI - The human immunoglobulin loci introduced into mice: V (D) and J gene segment
usage similar to that of adult humans.
AB - Variable gene segments of the human immunoglobulin loci are represented in the
human peripheral repertoire at different frequencies. XenoMouse strains contain
approximately 2 megabases of the human immunoglobulin heavy and kappa light chain
loci that functionally recapitulate the human humoral immune system. Analysis of
human antibody transcripts from XenoMouse spleens and lymph nodes revealed that
V, D and J gene segment utilization from these unimmunized animals were nearly
identical to the gene segment utilization reported for humans with extensive
antigenic histories.
PMID- 10671210
TI - Acellular components of Chlamydia pneumoniae stimulate cytokine production in
human blood mononuclear cells.
AB - Accumulating evidence suggest that infection with Chlamydia pneumoniae is
associated with atherosclerosis, but the mechanisms involved remain unclear.
Inflammation is important in the initial phase of atherogenesis, and cytokines
are important in the initiation and progression of inflammation. The aim of this
study was to assess the capacity of acellular components of C. pneumoniae to
stimulate the production of pro-inflammatory cytokines and chemokines. Peripheral
blood mononuclear cells were stimulated in vitro with sonicated C. pneumoniae.
Significant amounts of TNF-alpha, IL-1, IL-6, IL-8, monocyte chemoattractant
protein-1 (MCP-1) and macrophage inflammatory protein-1alpha (MIP-1alpha) were
produced. Inhibition of endotoxin using polymyxin B revealed that chlamydial
endotoxin plays a minor role in the cytokine induction. Neutralization of TNF by
TNF-binding protein and blockade of IL-1 receptors by IL-1 receptor antagonist
revealed that TNF, IL-1 and IL-6 production was independent from each other,
whereas IL-8 synthesis was strongly dependent on endogenous TNF and IL-1. In
contrast, synthesis of MCP-1 and MIP-1alpha was dependent on endogenous TNF, but
not IL-1. In conclusion, acellular components of C. pneumoniae are a potent
stimulus for cytokine production, and this mechanism may have an important role
in the inflammatory aspects of atherogenesis.
PMID- 10671211
TI - Differential expression of the B cell-restricted molecule CD22 on neonatal B
lymphocytes depending upon antigen stimulation.
AB - Newborns respond poorly to certain antigens and produce mainly IgM antibodies. By
flow cytometry we analyzed on neonatal and adult B cells the expression of CD22,
a B cell receptor (BCR)-associated membrane molecule, known as negative modulator
of BCR signaling. After T cell-independent (TI-)stimulation with anti-mu
F(ab')(2) fragments we found a dramatic decrease in the percentage of neonatal
CD22(+) B cells and CD22 mean fluorescence intensity (MFI) shift, whereas adult B
cells remained unaffected. Survival and proliferation rates of neonatal B cells
were higher compared to adult B cells whereas the degrees of apoptosis and
necrosis were comparable. Surprisingly, after stimulation with lower doses of
anti-mu apoptosis as well as proliferation increased significantly in contrast to
adult B cells. T cell-dependent (TD)-stimulation with anti-CD40 monoclonal
antibody and IL-4 resulted in a dramatic increase in the percentage of CD22(+)
neonatal B cells in contrast to unaffected adult B cells. CD22 MFI shifts showed
no significant changes, respectively. The survival rate was higher for adult B
cells, whereas apoptosis and cell death were comparable. These results suggest
that TI antigens lower the neonatal BCR signaling threshold via down-regulation
of CD22, resulting in hyperresponsive B cells apt to premature apoptosis. On the
other hand, up-regulation of CD22 after TD stimulation may allow increased
inhibiting influence of CD22 on neonatal BCR signaling, impairing B cell
activation and differentiation.
PMID- 10671212
TI - CXCR5-deficient mice develop functional germinal centers in the splenic T cell
zone.
AB - The chemokine receptor CXCR5 is thought to be essential for the migration of B
cells into the network of follicular dendritic cells in the spleen. However, as
shown here, B cells and follicular dendritic cells do co-localize, albeit
aberrantly, even in the absence of CXCR5. In mice lacking CXCR5 both cell types
are found in a broad ring around the sinuses of the marginal zones. Upon
immunization with the T cell-dependent antigen 2-phenyl-oxazolone, ectopic
germinal centers develop in the periarteriolar lymphocyte sheath. A network of
follicular dendritic cells forms in the vicinity of the central arteriole within
which the antigen-activated B cells proliferate. The analysis of the expressed V
gene repertoire revealed that during B cell proliferation, hypermutation is
activated and V region genes accumulate somatic mutations. The pattern of somatic
mutations suggests that affinity selection may occur. This analysis confirms that
in CXCR5-deficient mice, the organization of splenic primary follicles is
severely impaired. However, within the T cell zone a micro-environment is built
up, which provides all requirements needed for the affinity maturation to take
place.
PMID- 10671213
TI - Human KLRF1, a novel member of the killer cell lectin-like receptor gene family:
molecular characterization, genomic structure, physical mapping to the NK gene
complex and expression analysis.
AB - The human NK gene complex localized on chromosome 12p12.3 - p13.2 codes for
several lectin-like receptor genes expressed by NK cells as well as by other
hematopoietic cells. In this study, by using the expressed sequence tag database
we identified a novel receptor gene, designated as killer cell lectin-like
receptor, subfamily F, member 1 (KLRF1), encoding a putative type II
transmembrane glycoprotein. The KLRF1 gene has been localized on the high
resolution physical map of chromosome 12p. The genomic structure of the KLRF1
gene and the existence of one spliced variant are also described. KLRF1 was
expressed at the mRNA level in peripheral blood leukocytes, activated NK cells,
monocytes and NK and myeloid cell lines. The presence of two immunoreceptor
tyrosine-based inhibitory-like motifs within the cytoplasmic tail of KLRF1
suggests an inhibitory role in NK cell and monocyte activity.
PMID- 10671214
TI - CD7 expression distinguishes subsets of CD4(+) T cells with distinct functional
properties and ability to support replication of HIV-1.
AB - Enrichment of a subset of CD4(+)CD45R0(+)CD7(-) T cells has been observed in HIV
infected individuals. We have investigated the ability of CD7(+) and CD7(-) T
cells to support replication of HIV and show that virus replicates preferentially
in CD7(+) cells. Several possible mechanisms that may underlie such differences
in susceptibility to HIV were studied. Our data demonstrate that mitogen
stimulation induces poor expression of CD25 and IL-2 in CD7(-) compared with
CD7(+) cells. We also show that uninfected CD7(-) cells are more resistant to
mitogen-induced apoptosis than CD7(+) cells. Our data support the view that the
CD7(-) subset is inherently resistant to HIV replication and that this is due in
part to reduced CD25 expression and IL-2 production.
PMID- 10671215
TI - HLA-G inhibits the transendothelial migration of human NK cells.
AB - The expression of the non-classical MHC class I molecule HLA-G is normally
restricted to the placenta during pregnancy, where it is found on fetal
endothelial cells and on invasive cytotrophoblast cells, specifically those at
the maternal / fetal interface. Its precise physiological role has yet to be
defined. HLA-G may have nonimmune functions relating to angiogenesis and
placentation, but most evidence suggests that it protects fetal cells from lysis
by maternal uterine NK cells, which are found in large numbers around invading
trophoblast cells. This effect is due to specific interaction with inhibitory
receptors expressed on NK cells. We have examined the hypothesis that another
function of HLA-G is to inhibit NK cell migration. Using an in vitro
transmigration assay system, we present data to support this hypothesis. NK cell
migration across porcine endothelial cells transfected with HLA-G1 was
specifically inhibited compared to migration across HLA-A2-transfected
monolayers. HLA- G1 had no influence on the migration of a control T lymphocyte
line. These results support the idea that in vivo, HLA-G may inhibit NK cell
traffic across the placenta.
PMID- 10671216
TI - Heat shock proteins generate beta-chemokines which function as innate adjuvants
enhancing adaptive immunity.
AB - Heat shock proteins (HSP) are widely distributed and highly immunogenic
molecules. A novel property reported here is that stimulation with HSP70 of CD8
enriched T cells derived from naive non-human primates caused a dose-dependent
increase in concentrations of the beta-chemokines RANTES, macrophage inflammatory
protein (MIP)-1alpha or MIP-1beta. However, the concentrations of these beta
chemokines were greatly increased when the CD8 T cells derived from HSP70
immunized non-human primates were stimulated with HSP70. HSP linked to peptides
or proteins combined generation of beta-chemokines with an adjuvant function by
enhancing specific T cell proliferative responses and IgG and IgA antibodies. The
beta-chemokine and adjuvant functions were also elicited by topical mucosal
administration of HSP linked to an antigen. We postulate that microbial HSP can
stimulate beta-chemokine production which may be responsible for innate
adjuvanticity, as was found in cells eluted from normal rectal mucosal tissue,
and constitutes a significant component of the mucosal-associated lymphoid
system. Furthermore, stimulation of innate immunity may drive adaptive immunity
and account for the protective effects of HSP against tumors and viruses.
PMID- 10671217
TI - Xenopus NK cells identified by novel monoclonal antibodies.
AB - Early-thymectomized (Tx) Xenopus frogs, which are permanently deficient in T
cells, are used as a model sytem for the characterization of novel monoclonal
antibodies (mAb) which identify candidate NK cells at the amphibian level of
evolution. Hybridomas, generated from mice immunized with splenocytes from Tx
Xenopus following B cell and thrombocyte depletion, were screened by flow
cytometry. Three mAb (1F8, 4D4 and 1G5) were identified that stained increased
proportions of splenocytes from Tx compared with control frogs. These mAb
identified lymphoid populations from Xenopus spleen, liver and gut which, after
48 h culture in growth factor-rich medium, exhibited spontanous killing of MHC
deficient allotumor targets. mAb-defined splenocytes also rapidly induced
apoptosis of such tumor targets. Dual color analysis confirmed that NK cells are
neither T nor B cells. Cytospins of splenocytes isolated with anti-NK mAb
revealed large lymphoid cells with distinct pseudopodia. Immunohistology
indicated each anti-NK mAb routinely labeled cells within the gut epithelium but
NK cells were difficult to visualize in spleen sections. Western blotting of
spleen, liver and intestinal lysates subjected to sodium dodecyl sulfate
polyacrylamide gel electrophoresis showed that 1G5 reacted strongly with protein
bands of approximately 70 - 85 kDa, whereas mAb 1F8 and 4D4 stained less
intensely, but identified similar protein bands.
PMID- 10671218
TI - On the genetic mechanism of induction of CD3gamma-negative human T cell variants.
AB - Invariant CD3gamma molecules are important components in TCR complex formation
and function. Both CD3gamma alleles seem to be expressed co-dominantly. In the
present report, we present experimental data which indicate that the induction of
CD3gamma(-) Jurkat variants occurs with a frequency similar to that of TCRalpha(
) or TCRbeta(-) Jurkat cells. CD3delta(-), CD3epsilon(-) or CD3zeta(-) Jurkat
variants were never obtained despite extensive efforts. Our data suggest a
possible explanation for this genetic puzzle: the human CD3gamma gene has a
mutational hot spot in a nucleotide sequence of nine adenosines (9A) in the exon
3 encoding most of the external CD3gamma domain. Thus, both CD3gamma alleles are
easily mutated to either 8A or 10A sequences. Furthermore, absence of CD3gamma
molecules in Jurkat T cells causes severe defects in TCR / CD3 assembly and
function.
PMID- 10671219
TI - Unaltered phenotype, tissue distribution and function of Valpha14(+) NKT cells in
germ-free mice.
AB - The expression pattern of mouse CD1d and the tissue distribution of CD1d
restricted Valpha14-Jalpha281 NKT cells suggest that the liver and the marginal
zone of the spleen might be preferred sites of activation of this potent innate
pathway of early cytokine secretion. Because these tissues are particularly
involved with the filtration of blood-borne pathogens, and because NKT cells with
an activated / memory phenotype accumulate over the first weeks of life and their
CD1 ligands bind microbial glycolipids, it has been hypothesized that expansion
of the NKT cell subset may be driven by exposure to the microbial environment. To
test this hypothesis, we analyzed the frequency, surface phenotype and functional
properties of NKT cells in normal and in germ-free C57BL / 6 mice. Surprisingly,
we found that the NKT cell subset develops in the presence or absence of a
microbial environment. Although these results do not rule out the possibility
that NKT cells exert a protective function against some microbial agents, they
demonstrate that non microbial ligands, possibly self-antigens are sufficient for
the generation, maturation and peripheral accumulation of NKT cells.
PMID- 10671220
TI - Isolation of the intact white pulp. Quantitative and qualitative analysis of the
cellular composition of the splenic compartments.
AB - The spleen is anatomically and functionally divided into two compartments: the
red pulp, where particles are effectively removed from the blood, and the white
pulp, where specific immune responses are generated. Here the isolation of white
pulp from red pulp is described, allowing a detailed analysis of the cellular
components of both red and white pulp separately. A striking abundance of memory
T cells was found in the white and red pulp with an overall ratio of T and B
cells in the white pulp being similar to that in lymph nodes. Both NK and gamma
delta T cells can be found in white pulp and lymph nodes, but granulocytes are
absent. The distribution of dendritic cell subsets showed significant differences
between white pulp and lymph nodes. Furthermore, short-term homing experiments
showed that migration of lymphocytes into the white pulp greatly exceeded that
into lymph nodes, with significant differences in migration of various
lymphocytes subsets. This suggests a different migration and retention mechanism
in the white pulp. This new isolation technique will allow further analysis of
the functional capacities of the splenic compartments.
PMID- 10671221
TI - Conversion of p56(lck) to p60(lck) in human peripheral blood T lymphocytes is
dependent on co- stimulation through accessory receptors: involvement of
phospholipase C, protein kinase C and MAP-kinases in vivo.
AB - Activation of T cells requires co-stimulation of the TCR and accessory receptors
like CD2, CD4, CD8, CD11a or CD28. Engagement of the TCR without co-stimulation
results in anergy / apoptosis. Here we show that induction of the shift of the
tyrosine kinase p56lck from 56 kDa to apparent 60 kDa in resting human peripheral
blood T cells (PBT) is strictly dependent on co-stimulation through both TCR and
accessory receptors. In contrast, triggering of the TCR alone is only sufficient
to induce the lck shift in preactivated cells like T cell clones or the T
lymphoma line Jurkat. Our studies predict an involvement of a phospholipase C
isoform which surprisingly acts downstream of a phorbolester-sensitive, H7
insensitive protein kinase C. Inhibition of the lck shift in vivo by U73122, a
specific inhibitor of phospholipase C, correlates with reduced activation of the
MAP-kinases ERK1 / 2. Moreover, the MEK1-specific inhibitor PD98059 blocks the
lck shift in vivo. These findings demonstrate that activation of the MEK1-ERK1 /
2 pathway is required for lck conversion in vivo. The lck shift is not inducible
by co-stimulation through acidic sphingomyelinase or ceramides which even prevent
ERK2 activation in PBT. Moreover, it is resistant to treatment with W7, KN62 and
cyclosporin A.
PMID- 10671222
TI - CD69-triggered ERK activation and functions are negatively regulated by CD94 /
NKG2-A inhibitory receptor.
AB - CD69 represents a functional triggering molecule on activated NK and T cells,
capable of inducing cytotoxic activity and costimulating cytokine production. It
belongs to the C-lectin type superfamily, and its gene maps in the NK gene
complex, close to other genes coding for NK receptors. CD94 / NKG2-A complex is
the inhibitory receptor for the non classical MHC class I molecule HLA-E on human
NK cells. To investigate CD69-initiated signal transduction pathways, and to
evaluate CD94 / NKG2-A interference on CD69 triggering ability, we have generated
transfectants expressing both receptors in the RBL cell line. Here we report that
CD69 engagement leads to the activation of extracellular signal-regulated kinase
(ERK) enzymes belonging to the MAPK family, and that this event is required for
CD69-mediated cell degranulation. Moreover, we show that the co-engagement of
CD94 / NKG2-A inhibitory receptor effectively suppresses both CD69-triggered cell
degranulation in RBL transfectants, through the inhibition of ERK activation, and
CD69-induced cytotoxicity in human NK cells. Thus, here we provide new
information on the molecular mechanisms initiated by CD69 activation receptor,
and show that CD69-initiated signaling pathways and functional activity are
negatively regulated by CD94 / NKG2-A inhibitory complex.
PMID- 10671223
TI - A crucial role for p80 TNF-R2 in amplifying p60 TNF-R1 apoptosis signals in T
lymphocytes.
AB - Tumor necrosis factor-alpha (TNF-alpha) can elicit many cellular responses
including programmed cell death or apotosis. TNF-alpha-induced apoptosis has been
largely attributed to the p60 TNF-R1 receptor. The role of p80 in TNF-alpha
mediated apoptosis is largely unknown. We now present evidence that signaling
through p80 switches on the previously dormant apoptotic machinery associated
with p60. This effect on p60-associated apoptosis involves the proximal
activation of caspases and proceeds in the presence of strong NF-kappaB
induction. We evaluated the role of TRAF2 in p80-assisted apoptosis and found
that a decrease in TRAF2 protein occurs with p80 but not p60 stimulation.
However, the decrease in TRAF2 protein can be dissociated from apoptosis in the
presence of a caspase inhibitor. Hence, one means by which p80 TNF-R2 regulates
apoptosis is through its ability to amplify internally apoptotic signal
transduction from p60 TNF-R1.
PMID- 10671224
TI - T cell activation-induced and HIV tat-enhanced CD95(APO-1/Fas) ligand
transcription involves NF-kappaB.
AB - CD95(APO-1 / Fas) ligand (CD95L) gene expression is critically involved in
activation-induced T cell apoptosis. We and other have previously shown that HIV
1 Tat which is essential for efficient HIV gene expression sensitizes CD95
mediated apoptosis and up-regulates CD95L expression in T cells. In the present
study we have investigated the regulatory mechanism for CD95L expression. Two NF
kappaB binding sites are localized at - 537 to - 521 and - 57 to - 47 (relative
to the transcription start site) of the human CD95L promoter. We show that both
elements bind to NF-kappaB and SP-1 transcription factors and NF-kappaB is
involved in transactivation of the CD95L promoter upon T cell activation.
Mutations at each NF-kappaB site by two base pair substitutions resulted in 30 -
70 % reduction of the promoter activity. The effect of Tat on the human CD95L
promoter activity was mapped to the same sites. Mutation of each NF-kappaB site
also impaired the effect of Tat on CD95L promotor activity. We also show that
ectopic expression of Tat protein in Jurkat T cells greatly increases NF-kappaB
binding to its target DNA. Our studies provide evidence that Tat-enhanced CD95L
expression is regulated at least in part by the NF-kappaB sites of the promoter.
PMID- 10671225
TI - Effect of pre-existing cytotoxic T lymphocytes on therapeutic vaccines.
AB - Therapeutic vaccines which aim to induce CD8(+) cytotoxic T lymphocyte (CTL)
responses will often be required to perform in the presence of pre-existing CTL
which recognize epitopes within the vaccine. Here we explore the ability of a
viral vaccine vector presenting several co-dominant CTL epitopes to prime CTL
responses in animals that have a pre-existing CTL response to one of the epitopes
in the vaccine. The vaccine was usually capable of inducing multiple new
responses, suggesting that immunodomination effects of pre-existing CTL may
generally be minimal following vaccination. However, when large numbers of pre
existing CTL were present, a novel type of immune modulation was observed whereby
(1) the vaccine failed to prime efficiently new CTL responses that were
restricted by the same MHC gene as the pre-existing responses, and (2) vaccine
induced CTL responses restricted by other MHC genes were enhanced. These results
may have implications for therapeutic multi-epitope vaccines for diseases like
HIV and melanoma, which aim to broaden CTL responses.
PMID- 10671226
TI - Immune down-regulation and peripheral deletion of CD8 T cells does not require
TNF receptor-ligand interactions nor CD95 (Fas, APO-1).
AB - TNF receptor-ligand interactions and CD95 (Fas / APO-1) have been demonstrated to
be involved in activation-induced death of mature T cells. Here, we examined the
role of these molecules in the murine model of lymphocytic choriomeningitis virus
(LCMV) infection using LCMV TCR transgenic (tg) mice lacking TNF, TNF receptor I
(TNFR1), CD95 or both TNFR1 and CD95. This report demonstrates that neither TNF
receptor-ligand interactions nor CD95 was required for down-regulation of LCMV
specific CD8 T cells following acute LCMV infection in vivo. Even LCMV-specific
CD8 T cells lacking both TNFR1 and CD95 molecules declined after the acute phase
of the infection with normal kinetics. Furthermore, peripheral deletion of LCMV
specific CD8 T cells induced by LCMV peptide injection or by adoptive transfer of
tg spleen cells expressing the corresponding LCMV epitope was not impaired in
mice lacking TNF, TNFR1 and / or CD95. Our data speak against an indispensable
role of these molecules in antigen-induced apoptosis of CD8 T cells in vivo and
suggest that T cell homeostasis after antigen challenge is controlled by
additional mechanisms.
PMID- 10671227
TI - TNF receptor 1 (TNFR1) and CD95 are not required for T cell deletion after virus
infection but contribute to peptide-induced deletion under limited conditions.
AB - Deletion of mature T cells maintains cellular homeostasis and is involved in the
maintenance of self tolerance to some peripheral self antigens. Previous studies
have presented conflicting evidence for a role of the tumor necrosis factor
receptor (TNFR) family member CD95 (Fas) in peripheral T cell deletion using CD95
deficient mice. To evaluate cooperation between CD95 and another TNFR family
molecule, TNFR1, we generated mice deficient for both CD95 and TNFR1. We showed
that TNFR1 and CD95 do not contribute to the decline of antigen-specific
cytotoxic T lymphocytes after virus infection. Using TNFR1 / CD95-deficient mice
expressing the P14 TCR specific for a lymphocytic choriomeningitis virus-derived
peptide (p33) we showed that deletion of p33-specific CD8(+) T cells following
high dose p33 administration is also normal. However, in non-TCR-transgenic TNFR1
/ CD95-deficient mice treated with the same p33 regimen, tolerance induction was
defective. These data indicate that TNFR1 and CD95 are dispensable for deletion
of antigen-specific T cells after viral infection. However, under certain
conditions, both TNFR1 and CD95 appear to cooperate in CD8(+) T cell deletion.
PMID- 10671228
TI - B cell clonal elimination induced by membrane-bound self-antigen may require
repeated antigen encounter or cell competition.
AB - Transgenic mouse experiments indicate that autoreactive B cells are eliminated
upon encounter with membrane self-antigen. In this study we tested how B cell
tolerance to MHC class I antigens is affected by altering the frequency of
antigen-carrying cells in mixed bone marrow (BM) chimeras. When antigen-bearing
cells are present at low frequency, the reactive B cells and their antigens may
coexist in the peripheral lymphoid organs, but under these conditions the B cells
are functionally anergic and have a shortened lifespan. Such putative anergic
cells are strongly deleted in the presence of additional, non-antigen-bearing,
non-transgenic B cells. Since the antigen concentration on the surface of each
antigen-bearing cell should be high, these results suggest that for efficient
deletion of autoreactive B cells multiple antigen encounters may be required,
particularly when cellular competition is weak. These results have implications
for the therapeutic use of BM chimerism to induce B cell tolerance to grafts.
PMID- 10671229
TI - Molecular characterization of two novel C-type lectin-like receptors, one of
which is selectively expressed in human dendritic cells.
AB - We have identified two human C-type lectin-like receptors, CLEC-1 and CLEC-2.
Both display a single carbohydrate recognition domain and a cytoplasmic tyrosine
based motif. They are homologous to the NK cell receptors NKG2s and CD94 and also
to the oxidized low-density lipoprotein receptor 1. CLEC-1 and CLEC-2 are
preferentially transcribed in dendritic cells (DC) and in the liver,
respectively. Following transient transfection in COS cells, CLEC-1 is expressed
intracellularly, perhaps requiring an associated chain to reach the cell surface.
CLEC-2 is expressed on the surface of transfected cells as a protein of
approximately 33 kDa. CLEC-1 and CLEC-2 genes map to human chromosome 12, most
likely in linkage with the NK gene complex (NKC). Thus, the NKC may encode C-type
lectin-like receptors expressed not only in NK cells but also in other cells, and
at least one of these is of potential importance in regulating DC function.
PMID- 10671230
TI - Dendritic cell maturation is induced by mycoplasma infection but not by necrotic
cells.
AB - To identify environmental stimuli that induce dendritic cell (DC) maturation, we
exposed human monocyte-derived immature DC to apoptotic or necrotic cells and
measured the levels of expression of costimulatory molecules and cytokine
production. While most necrotic or apoptotic cells did not have any effect, some
induced DC maturation as detected by up-regulation of CD83 and B7.2 and
production of IL-12 and IL-6. The capacity of these cell lines to induce DC
maturation was due to their contamination by mycoplasma, since the maturation
inducing effect disappeared when the cells were treated with cyproxin.
Furthermore, cell lines deliberately infected with mycoplasma containing
supernatant acquired the capacity to induce DC maturation. Our results reveal
that DC are able to sense mycoplasma infection and mature as they do in response
to most viruses and bacteria. In contrast, apoptotic or necrotic cells fail to
induce DC maturation.
PMID- 10671231
TI - Activation of Cdk2 is a requirement for antigen-mediated thymic negative
selection.
AB - Apoptosis plays a critical role in T cell development and thymic selection.
Thymocytes which undergo antigen-induced negative selection have been
demonstrated to die by apoptosis. Despite this, relatively little is known about
the specific apoptotic pathway involved in negative selection. We have examined
the role of cyclin-dependent kinase 2 (Cdk2), a key regulator of thymocyte
apoptosis, in this process. Stimulation of thymocytes with cognate antigen leads
to a large increase in Cdk2 kinase activity. We also show that pharmacological
inhibitors of Cdk2 block thymocyte apoptosis in response to antigen. Our data
show that Cdk2 activity is essential for the apoptotic pathway used in negative
selection.
PMID- 10671232
TI - Impact of in utero Th2 immunity on T cell deviation and subsequent immediate-type
hypersensitivity in the neonate.
AB - It was the aim of this study to analyze the impact of maternal Th2 immune
responses on onset and subsequent development of allergen-specific immunity and
immediate-type hypersensitivity in early childhood. In a well characterized mouse
model of Th2 immunity, BALB / c mice were sensitized to ovalbumin (OVA) before
mating followed by allergen aerosol exposure during pregnancy. At the end of
pregnancy mice developed allergen-specific Th2 / Th0 immunity and immediate-type
hypersensitivity responses to OVA. T cells from these newborns, when restimulated
with PMA / ionomycin, demonstrated a lowered capacity to produce IFN-gamma. To
assess whether prenatal allergen exposure favors postnatal onset of a Th2-type
immune response, these offspring were immunized to a novel antigen by a single
injection of beta-lactoglobulin (BLG). In contrast to offspring from non
sensitized mothers, offspring from OVA-sensitized mice showed both higher anti
BLG immunoglobulin titers and higher frequencies of immediate-type skin test
responses. Our data suggest that Th2 / Th0 immunity present during pregnancy has
a decisive impact on shaping of the Th1 / Th2 T cell profile in the neonate.
Furthermore, this effect favors the development of Th2 immune responses, when
mice are exposed to a novel antigen during early childhood.
PMID- 10671233
TI - Post-transcriptional regulation of E2A proteins via lipopolysaccharide and CD40
signaling.
AB - The transcription factor E2A plays a crucial role in B cell development, the
control of immunoglobulin gene rearrangement and expression. Here we report that
in primary mouse B cells lipopolysaccharide (LPS) is able to induce the level of
E2A protein by over 50-fold in days of culture. In contrast, CD40 signaling is
insufficient to cause an E2A increase and can in fact prevent the LPS-mediated
induction of E2A. These results suggest that E2A induction requires both
proliferation and differentiation. We find that E2A protein induction is
regulated post-transcriptionally since E2A mRNA is not induced by LPS. We have
thus identified an important additional layer of regulation affecting the
activity of E2A transcription factors.
PMID- 10671235
TI - Highlights in the Renaissance of Amidometal Chemistry.
AB - Turning a disadvantage to an advantage: The rather disappointing reactivity of
the metal - nitrogen bond in comparison to the metal - carbon bond resulted in
the neglect of amidometal chemistry after its heyday at the end of the 1960s and
beginning of the 1970s. Today it is precisely this disadvantage which is being
applied through the use of amido ligands to produce inert complex fragments with
well-defined reaction centers. In this way the chemistry of the early transition
metals has been markedly enriched, and interesting alternatives to the
classically regarded cyclopentadienyl ligands are now available.
PMID- 10671234
TI - Dissecting the Chemistry of Protein Splicing and Its Applications.
AB - Protein splicing, the protein equivalent of RNA splicing, is a newly discovered
posttranslational process that proceeds through a branched protein intermediate
and produces two separate polypeptides from one gene. The experimental data used
to distinguish among the proposed protein-splicing mechanisms are presented along
with the progress made towards fully describing the mechanism. Numerous protein
engineering applications using modified inteins have been developed, including
the generation of alpha-thioesters in proteins, which circumvent the limits of
solid-phase peptide synthesis.
PMID- 10671237
TI - "Breaking the Rules": A Planar Phosphonium Cation.
AB - Long-standing tenets of a discipline must be questioned in an effort to fully
understand the fundamentals of science. This is exemplified by the synthesis of
planar-tetracoordinate compounds, such as the square-planar phosphonium ion 1 by
Driess et al., which provide exceptions to van't Hoff - Le Bel rules.
PMID- 10671236
TI - How Long Have Nonlinear Effects Been Known in the Field of Catalysis?
AB - The similarities and differences between nonlinear effects in asymmetric
synthesis (see diagram), predicted 60 years ago by W. Langenbeck, and the long
known amplification phenomenon in stoichiometric reactions with chiral starting
materials are discussed.
PMID- 10671238
TI - How Many Networks Can Be Made from Four-Coordinate Atoms?
AB - In how many ways can three-dimensional space be divided into tiles such that four
edges meet at every vertex? A procedure to calculate the number of possibilities
was recently presented by the mathematician A. Dress. Some of the tilings
correspond to the structures of zeolites and other networks.
PMID- 10671239
TI - How to Make Drugs Orally Active: A Substrate Template for Peptide Transporter
PepT1.
AB - By building key structural features into hydrophilic drugs, they can be
recognized by the PepT1 transporter system of the small intestine and rendered
orally active. The model shown provides, for the first time, a 3D template for
all known substrates of PepT1.
PMID- 10671240
TI - Cholesteric Solid Films Formed by Spin-Coating Solutions of Dicholesteryl Esters.
AB - Helical ordering of molecules is shown by solid films formed by spin-coating
solutions of nonpolymeric, high molecular weight dicholesteryl esters (shown
schematically). In these three-dimensionally organized films the axes of the
helices are perpendicular to the surface of the glass plate.
PMID- 10671241
TI - Al(30): A Giant Aluminum Polycation.
AB - Simple hydrothermal treatment of the well-known aluminum polycation varepsilon
Al(13) produces the novel Al(30) structure (see picture), the largest polycation
yet observed. Its characterization, by X-ray diffraction and NMR spectroscopy,
also solved previously unassigned signals in (27)Al NMR spectra of other Al - O
species.
PMID- 10671242
TI - The Vibrational Inelastic Neutron Scattering Spectrum of Dodecahedrane:
Experiment and DFT Simulation.
AB - Vibrational frequencies that are forbidden in Raman and IR absorption can be
observed by inelastic neutron scattering. In the case of the I(h)-symmetrical
molecule dodecahedrane (shown schematically), the resulting spectrum agrees with
a DFT calculation.
PMID- 10671243
TI - Supramolecular Materials with Electroactive Chemical Functions.
AB - A diblock coil with diphenylaminophenyl side chains, oligoethylene oxide
segments, and a rigid molecular pentamer of phenylene vinylene are present in the
molecule studied here (see formula). When films of this material were
investigated, the material was found to organize into nanostructures 12 nm in
dimension.
PMID- 10671244
TI - Kinetic Footprinting of an RNA-Folding Pathway Using Peroxynitrous Acid.
AB - Following footprints to discover a path is easier with peroxynitrous acid. The
folding of the Tetrahymena ribozyme was studied using this readily available
reagent to generate hydroxyl radicals for kinetic footprinting studies. The
different domains of the ribozyme appear to assemble at different rates following
an ordered, hierarchical pathway (see scheme).
PMID- 10671245
TI - Solvation of the Carbonyl Compound as a Predominant Factor in the Diastereofacial
Selectivity of Nucleophilic Addition.
AB - Temperature-dependent selectivity in nucleophilic additions is affected by the
solvent. The inversion temperature (marked with arrows in the graph) that appears
in the nonlinear Eyring plots of ln (anti/syn) versus temperature for the
addition of butyllithium to an O-protected alpha-hydroxy aldehyde 1 does not
depend on nucleophiles (nBuLi (black triangle), tBuLi (*)), but on the solvent.
Its value can be obtained from a plot of the (13)C NMR chemical shift of C=O
versus temperature. TBDMS=tBuMe(2)Si.
PMID- 10671246
TI - Novel Single- and Double-Layer and Three-Dimensional Structures of Rare-Earth
Metal Coordination Polymers: The Effect of Lanthanide Contraction and Acidity
Control in Crystal Structure Formation.
AB - Lanthanide atom sizes (the lanthanide contraction) directly control the type of
structure formed by the coordination of a single multidentate ligand, 3,5
pyrazoledicarboxylic acid (H(3)pdc). Single-layer, double-layer
([Eu(2)(Hpdc)(3)(H(2)O)(6)], see picture), and three-dimensional networks were
found. Control of the reaction pH plays a key role in the structure formation in
this system.
PMID- 10671247
TI - Synthesis of an alpha-(2,3)-Sialylated, Complex-Type Undecasaccharide.
AB - Only two building blocks were necessary to provide efficient access to the
complex undecasaccharide 1 by means of two stereo- and regioselective
glycosylation reactions. Stereocontrolled p-methoxybenzyl-assisted beta
mannosylation afforded the critical beta-mannoside linkage in 1, which is a
constituent of the human glycoproteins follitropin and gonadotropin.
PMID- 10671248
TI - Construction of Heterometallic Cubanes
AB - Incorporation of M(CO)(3) fragments by trinuclear Ti complexes
[{Ti(3)Cp(u(3)-CR)}(u-O)(3)] and
[{Ti(3)Cp(u(3)-N)}(u-NH)(3)] (Cp*=eta(5)
C(5)Me(5)) leads to the formation of an unprecedented class of heterometallic
clusters with cubane structure [e.g., Eq. (a)]. Density functional calculations
on these complexes indicate the existence of electron delocalization in the
Ti(3)M cores (M=Cr, Mo, W).
PMID- 10671249
TI - Coupling of Alkynes on a Pd-Pd Bond to Generate an Electrophilic u
Butenediylidene Moiety.
AB - The first dipalladium u-PPh(3) complex (1) was obtained by the facile loss of two
CH(3)CN ligands from [Pd(2)(PPh(3))(2)(CH(3)CN)(4)](PF(6))(2) in CH(2)Cl(2).
Coupling of p-tolylacetylene (p-TolC identical withCH) with 1 or its precusor
afforded the u-butenediylidene complex 2, treatment of which with CH(3)CN
resulted in PPh(3) migration to give 3.
PMID- 10671250
TI - Evidence for an Equilibrium between an N-heterocyclic Carbene and Its Dimer in
Solution.
AB - Evidence for the Wanzlick equilibrium between carbene 1 and
dibenzotetraazafulvalene (1)(2) at ambient temperature has been found (see
scheme). Enetetramines of type (1)(2) can also be cleaved by coordinatively
unsaturated transition metal compounds to form dicarbene complexes.
PMID- 10671251
TI - Chromophore Alignment in a Chiral Host Provides a Sensitive Test for the
Orientation - Intensity Rule of Induced Circular Dichroism.
AB - Different inclusion modes can be realized for a bicyclic azoalkane in beta
cyclodextrin (see picture). Variations in the alignment of the azo chromophore
relative to the host can be detected through NMR spectroscopy and induced
circular dichroism. The latter technique produces a positive signal for the
lateral conformer and a negative, significantly weaker peak for the frontal one.
This is in keeping with the orientation-intensity rule.
PMID- 10671252
TI - Macrocyclic Imidazolylboranes.
AB - Cycles, not chains: 1-imidazolylboranes exist in polymeric form as a consequence
of donor/acceptor interactions. Through the use of suitable substituents and
under high dilution tetrameric and pentameric macrocyclic imidazolylboranes were
synthesized. The picture shows the structure of the tetrameric 4,5
dimethylimidazolylborane (black: C, gray: B, white: N).
PMID- 10671253
TI - Nitrophenolate as a Building Block for Lanthanide Chains and Clusters.
AB - Infinite, extended chains or tetradecanuclear lanthanide clusters (see structure)
can be formed, depending on conditions, from the reaction of potassium o
nitrophenolate with different lanthanide trichlorides.
PMID- 10671254
TI - Molecular Recognition of Carbohydrates by Artificial Polypyridine and
Polypyrimidine Receptors.
AB - Despite their acyclic structure, the simple host molecules 1 and 2 can
effectively hydrogen bond to monosaccharides. They show marked binding affinities
to glucopyranosides in chloroform, and they are able to participate in three
dimensional recognition of monosaccharides.
PMID- 10671255
TI - Sequential Nucleophilic Substitution: A Powerful Strategy for the Solid-Phase
Production of Diverse Compound Libraries.
AB - Polyfunctionalized, unprotected reagents (e.g. amines and thiols) can be used in
the production of highly diverse compound libraries by performing sequential
nucleophilic substitutions on support-bound polyelectrophiles (see scheme). The
procedure reported here enables the efficient preparation of new beta-alanine
derivatives which are suitable for lead discovery. E*=polyelectrophile, *=solid
support.
PMID- 10671256
TI - New Solvatochromic Dyes of the 5-Dimethylamino-5'nitro-2,2'-bithiophene Type.
AB - The first serious competitor to the known solvatochromic pyridiniumphenolate
betaines has been uncovered with the 5-dimethylamino-5'-nitro-2,2'-bithiophene 1
a (X=Z=S, Y=CH, R=CH(3)), which has the added benefit of being notably sensitive
to solvent in acidic media. By simple heterocyclization further compounds of the
general type 1 have been synthesized, and their suitability as solvent indicators
was investigated. In this way a new record was set with the selenophene analogue
of 1 a.
PMID- 10671257
TI - Doubly meso-beta-Linked Diporphyrins from Oxidation of 5,10,15-Triaryl
Substituted Ni(II)- and Pd(II) - Porphyrins.
AB - Lower oxidation potentials than for the monomeric starting materials are
displayed by the diporphyrins obtained by one-electron oxidation with tris(4
bromophenyl)ammonium hexachloroantimonate [see, for example, Eq. (1)]. This and
the strong red shift observed for the Soret bands of the product are indicative
of extensively delocalized pi-electron systems in the fused diporphyrin. Ar=3,5
di-tert-butylphenyl.
PMID- 10671258
TI - [Ni]
AB - How do [NiFe] hydrogenases activate H(2)? Hydrogenases are key enzymes in the
biological hydrogen and energy metabolism; the mechanism of H(2) activation,
however, is unclarified. In particular, the oxidation states of the metals
involved are discussed controversially. The title complex demonstrates that a
distorted diamagnetic Ni(II) center and thiolate donors are sufficient (see
picture) to catalyze the key reaction of hydrogenases, the H(2) heterolysis.
PMID- 10671259
TI - A New Synthetic Route to Unsymmetrical 1,2-Bis(phosphanyl)ethanes and 1,2
Arsanyl(phosphanyl)ethanes with and without a Stereogenic Center.
AB - A one-pot reaction affords unsymmetrical 1,2-bis(phosphanyl)ethanes 2 and 1,2
arsanyl(phosphanyl)ethanes 3 from the cyclic sulfate 1 in high yield. Similarly,
chiral 1,2-bis(phosphanyl)ethanes and 1,3-bis(phosphanyl)propanes could be
obtained in enantiomerically pure form. R, R'=alkyl, phenyl.
PMID- 10671260
TI - A Novel Polymer-Supported Scandium Catalyst Which Shows High Activity in Water.
AB - Lewis acids in water on a polymer support (1) have been used, for the first time,
as a catalyst. The organic solvent-free catalytic activity, first tested with
allylation reactions with tetraallyltin, extended to other Lewis acid catalyzed
reactions with a range of carbonyl compounds to afford the corresponding alcohol;
reactions of aromatic, aliphatic, heterocyclic aldehydes and even ketones
proceeded smoothly. Catalyst recovery was quantitative after simple filtration.
PMID- 10671262
TI - Diastereoselective Ce(OiPr)(3)-Catalyzed Pinacol Couplings of Aldehydes.
AB - Aliphatic aldehydes as well as aromatic aldehydes can be converted by means of
cerium-catalyzed pinacol coupling [Eq. (1)]. The coupling reaction products can
be isolated with good to very good diastereoselectivities in favor of rac isomers
(rac:meso>88:12). R=alkyl, aryl.
PMID- 10671261
TI - A New Variant of the Claisen Rearrangement from Malonate-Derived Allylic
Trimethylsilyl Ketene Acetals: Efficient, Highly Enantio- and Diastereoselective
Syntheses of (+)-Methyl Dihydroepijasmonate and (+)-Methyl Epijasmonate.
AB - Complete chirality transfer occurs in the smooth Claisen rearrangement of the
trimethylsilyl (TMS) ketene acetals, which were prepared from allylic malonates
(R)-1 (R=pentyl, 2-(Z)-pentenyl). These are in turn accessible by
enantioselective reduction/esterification or by enzymatic kinetic resolution. The
cis configuration in (+)-3 was achieved by highly syn-selective epoxidation of
(+)-2, followed by suprafacial 1,2-H migration.
PMID- 10671263
TI - The First Functionalized 6,12-Diazatetrakishomocubanes.
AB - The photodimerization of asymmetric 4-aryl-1,4-dihydropyridines results, totally
unexpectedly, in the new 6,12-diazatetrakishomocubanes 1. This is in contrast to
the previously observed [2+2] photocycloaddition reactions of symmetrical 4-aryl
1,4-dihydropyridines
PMID- 10671264
TI - Formation of a Novel Cage Compound with a Pentacyclo
AB - Abnormally long C-C single bonds are found in the polycyclic caged diol with a
pentacyclo[6.3.0.1(4,11).0(2,6).0(5,10)]dodecane skeleton formed by photolysis
(see scheme). This skeleton resembles the structure of diamantane, but instead of
having six cyclohexane rings in a chair conformation it contains only two
cyclohexane rings in a distorted chair conformation and four cyclopentane rings,
which makes it more highly strained than diamantane.
PMID- 10671265
TI - How Stable Are Epoxides? A Novel Synthesis of Epothilone B.
AB - Remarkable stability of the oxirane function is displayed over a number of
synthetic operations in a novel synthesis of the antitumor compound epothilone B
(see scheme). The cis-epoxide, generated very early by dihydroxylation of an (E)
olefin, was resistant to more than ten synthetic steps under a wide variety of
reaction conditions. TBS=tert-butyldimethylsilyl.
PMID- 10671266
TI - Identification of Toxic 2,4-Decadienal in Oxidized, Low-Density Lipoprotein by
Solid-Phase Microextraction.
AB - The oxidation of low-density lipoprotein (LDL) in vitro was studied by a
combination of solid-phase microextraction and GC/MS. 2-trans,4-cis-2,4
Decadienal, which is strongly toxic in vitro, was detected as the early oxidation
product. This compound is degraded further to hexanal and (by cyclization of 4
hydroxy-2-nonenal) to 2-pentylfuran.
PMID- 10671267
TI - Oxidation of Linoleic Acid in Low-Density Lipoprotein: An Important Event in
Atherogenesis.
AB - Contrary to earlier views the main oxidation products of low-density lipoprotein
(LDL) are derived from linoleic acid and not arachidonic acid, as determined by
GC/MS investigations of the in vitro oxidation of LDL samples. A similar product
spectrum, in which epoxyhydroxyoctadecenoic acids such as 1 and 2 have been
identified for the first time, is obtained from minimally oxidized (that is,
aged) LDL. Since this is still recognized by the LDL receptor, it is concluded
that toxic oxidation products are introduced in endothelial cells in vivo and
cause damage there.
PMID- 10671268
TI - Radical Intermediates in the Jacobsen - Katsuki Epoxidation.
AB - Insight into the controversial mechanism of the Mn - salen-catalyzed epoxidation
of olefins is provided in a theoretical study based on density functional theory.
The calculations suggest that radical species A, but not manganaoxetanes B, are
likely candidates for viable intermediates.
PMID- 10671269
TI - Molecular Design of Liquid-Crystalline Block Molecules: Semifluorinated
Pentaerythritol Tetrabenzoates Exhibiting Lamellar, Columnar, and Cubic
Mesophases.
AB - Fluid assemblies of star-shaped molecules like 1 form a range of thermotropic
liquid crystalline phases, and represent a borderline case between anisometric
mesogens, surfactants, and block copolymers. The low molecular mass molecules
(<5.5 kDa) consist of a semipolar central core and a shell of semifluorinated
chains.
PMID- 10671270
TI - New Building Blocks for the Design of Oligonuclear Copper Complexes Based on
Amino Carbohydrates.
AB - Remarkably high magnetic coupling and O(2)-activation ability analogous to that
of catechol oxidase are characteristics of the first structurally defined, low
symmetry oligonuclear copper complexes of tridentate beta-oxoenamine ligands
based on amino carbohydrates (the structure of a
bis(acetylbutenonylaminoglucosidato)bis(u-acetato)tricopper(II) complex is
shown).
PMID- 10671271
TI - Simple Synthesis of a Chlorin - Fullerene Dyad with a Novel Ring-Closure
Reaction.
AB - To model the photosynthetic reaction center, the chlorin - fullerene dyad 1 was
synthesized in a one-pot reaction from a linear tetrapyrrole and C(60). It is the
first dyad of this type which contains a fullerene and a chlorin unit, the
chromophore of naturally occurring photosynthetic systems.
PMID- 10671272
TI - The First Crystal Structure of a Germanium(II) Amide with a Germanium - Lithium
Bond and Its Behavior Towards Oxygen and Water.
AB - The Ge-Li bond in 1 reacts readily with water and oxygen to give 2 (Li/H
exchange) and 3 (insertion), respectively. In both cases the partial charge and
the oxidation state of the germanium atom changes. All compounds were
characterized by X-ray crystallography.
PMID- 10671273
TI - Crystal Design of Barium Sulfate using Double-Hydrophilic Block Copolymers.
AB - Peach, peanut, fiber, and flower (see picture) crystal morphologies are achieved
from the precipitation of simple minerals in the presence of specifically
adsorbing polymers. These crystal design effects are illustrated using BaSO(4)
and double-hydrophilic block copolymers, the latter featuring carboxylate,
sulfonate, phosphonate, and aspartic acid groups.
PMID- 10671274
TI - Three-Strand Conducting Ladder Polymers: Two-Step Electropolymerization of
Metallorotaxanes.
AB - Sequential polymerization of supramolecular metallorotaxane complexes results in
three-stranded conducting ladder polymers. The internal polymer is "sandwiched"
between the other two polymers to give molecular wires that are effectively
insulated when the outer polymers are in their nonconducting state (shown
schematically). The intermolecular conductivity can be mediated by the
Cu(1+)/Cu(2+) redox couple.
PMID- 10671275
TI - Polar Thin Films Produced by Phosphonium Liquid Crystals: Two-Dimensional Self
Assembled Ionic Layers with Spontaneous Polarization.
AB - Nonlinear optical properties are shown by the smectic phase formed by simple
dialkyl phosphonium salts. The molecules form into layers, featuring ion pairs
separated by insulating glassy alkyl coating to produce a spontaneous
polarization (P(s)) in the sheets (see picture). Applications of this material
are currently leading to the development of novel electrical and electrooptical
devices.
PMID- 10671276
TI - Global Chirality in Rigid Decametallic Ruthenium Dendrimers.
AB - Metallodendrimers with ten chiral Ru centers have been prepared in a
stereospecific fashion (see picture; *=chiral Ru(diimine)(3) center). These
molecules are conformationally rigid and exhibit well-defined global topologies:
some diastereomers exhibit macroscopically chiral structures, others show a
disklike topology. This difference in global or tertiary structure is exemplified
by differences in their colloidal behavior, as observed in electric birefringence
measurements.
PMID- 10671277
TI - On the Location of Li(+) Cations in the Fast Li-Cation Conductor
La(0.5)Li(0.5)TiO(3) Perovskite.
AB - Lithium cations sit in the center of the oxygen "windows" defined by the vertex
sharing TiO(6) octahedra of the title compound (see picture), as shown from
neutron diffraction data. The octahedra are tilted to optimize the bond distances
between the atoms. The unusual coordination and the partially unoccupied
sublattice (occupancy factors 1/6 and (1/2) for Li and La, respectively) account
for the high mobility of the Li(+) cations.
PMID- 10671278
TI - New Synthetic Technology for the Rapid Construction of Novel Heterocycles-Part 1:
The Reaction of Dess - Martin Periodinane with Anilides and Related Compounds.
AB - The unusual behavior of hypervalent iodine reagents, Dess - Martin periodinane
and IBX, with an array of anilides leads to the formation of complex heterocycles
in only one synthetic operation (see scheme). Furthermore, the substrates for
these transformations are available in one step from readily available commercial
building blocks. The mechanism by which these periodinanes interact with anilides
is also explored. This exciting new class of chemical reactions was discovered
during the course of the total synthesis of the CP molecules and leads to
compounds which are relevant to chemical biology investigations and
pharmaceutical research.
PMID- 10671279
TI - New Synthetic Technology for the Rapid Construction of Novel Heterocycles-Part 2.
The Reaction of IBX with Anilides and Related Compounds.
AB - The unusual behavior of hypervalent iodine reagents, Dess - Martin periodinane
and IBX, with an array of anilides leads to the formation of complex heterocycles
in only one synthetic operation (see scheme). Furthermore, the substrates for
these transformations are available in one step from readily available commercial
building blocks. The mechanism by which these periodinanes interact with anilides
is also explored. This exciting new class of chemical reactions was discovered
during the course of the total synthesis of the CP molecules and leads to
compounds which are relevant to chemical biology investigations and
pharmaceutical research.
PMID- 10671280
TI - Cationic Phosphonolipids Containing Quaternary Phosphonium and Arsonium Groups
for DNA Transfection with Good Efficiency and Low Cellular Toxicity**
AB - Replacing the ammonium polar head in cationic lipids 1 (A=N) by a phosphonium or
an arsonium group (A=P, As) improves their properties as synthetic vectors for
DNA transfection. The increased volume of the cationic head is supposed to modify
the interactions of the vector with the solvent and DNA.
PMID- 10671281
TI - Phosphane Sulfide/Octacarbonyldicobalt-Catalyzed Pauson - Khand Reaction Under an
Atmospheric Pressure of Carbon Monoxide.
AB - Convenient access to cyclopentenones is provided by catalytic intra- and
intermolecular Pauson - Khand reactions in the presence of octacarbonyldicobalt
and tributylphosphane sulfide (see scheme). In contrast to other reactions of
this type, they proceed under mild conditions (70 degrees C, 1 atm CO), and
commercially available [Co(2)(CO)(8)] can be used without further purification.
PMID- 10671282
TI - Synthesis and Properties of an Overcrowded Silabenzene Stable at Ambient
Temperature.
AB - Solid-state, room-temperature stability for silabenzene 1 is granted by the bulky
silane rendering kinetic inertness. Silabenzene 1 is synthesized in good yield
from the crowded chlorosilane 2 with tert-butyllithium. The delocalized, aromatic
nature of 1 was confirmed by NMR spectroscopy and the (1)J(Si-C) value, as well
as calculations on an analogous silabenzene.
PMID- 10671283
TI - Catalytic Intermolecular Pauson - Khand Reactions in Supercritical Ethylene.
AB - Ethylene is not only a substrate, but also a solvent: Catalytic intermolecular
Pauson - Khand reactions of terminal alkynes were carried out in supercritical
ethylene to provide 2-substituted cyclopentenones in moderate to high yields [Eq.
(1)]. Under these conditions, even a low pressure of CO (5 atm) is sufficient for
the reaction to take place.
PMID- 10671284
TI - The First Red Azo Lake Pigment whose Structure is Characterized by Single Crystal
Diffraction.
AB - A model for red azo pigment Ca4B was characterized structurally using synchrotron
radiation. This highly anisotropic ladder structure represents a new structural
class in azo pigment chemistry. The picture shows that the calcium atoms
coordinate in a complex manner to three azo ligands (one terdentate, one
bidentate, and one monodentate) and two water molecules simultaneously.
PMID- 10671285
TI - Detection of Toxoplasma gondii soluble antigen, SAG-1(p30), antibody and immune
complex in the cerebrospinal fluid of HIV positive or negative individuals.
AB - Active infection by T. gondii was evaluated by immunoassay for soluble SAG-1
(p30), the major surface antigen from T. gondii, specific antibodies and immune
complexes in human cerebrospinal fluid (CSF) samples. A total of 263 samples of
CSF were collected from hospitalized patients presenting neurological disorders
and analyzed for antibodies to HIV. Patients were divided into two groups: HIV
positive (n = 96) or HIV negative (n =167). The results of the assays showed that
45% of all samples were positive for soluble SAG-1. Toxoplasma Ag/Ab immune
complexes were detected in 19% of the CSF samples and 62% were positive for T.
gondii- specific IgG. A combination of these assays in the presence of clinical
findings consistent with active Toxoplasma infection may predict the presence of
toxoplasmic encephalitis. Moreover, detection of soluble SAG-1 in the CSF of
these individuals appears consistent with active infection.
PMID- 10671286
TI - Diagnosis of plague and identification of virulence markers in Yersinia pestis by
multiplex-PCR.
AB - We have developed a procedure for the rapid diagnosis of plague that also allows
the identification of prominent virulence markers of Y. pestis strains. This
procedure is based upon the use of a single polymerase chain reaction with
multiple pairs of primers directed at genes present in the three virulence
plasmids as well as in the chromosomal pathogenicity island of the bacterium. The
technique allowed the discrimination of strains which lacked one or more of the
known pathogenic loci, using as template total DNA obtained from bacterial
cultures and from simulated blood cultures containing diluted concentration of
bacteria. It also proved effective in confirming the disease in a blood culture
from a plague suspected patient. As the results are obtained in a few hours this
technique will be useful in the methodology of the Plague Control Program.
PMID- 10671287
TI - Partial chemical characterization of antigenic preparations of
chromoblastomycosis agents.
AB - Antigenic preparations (saline, methylic, metabolic and exoantigens) of four
agents of chromoblastomycosis, Fonsecaea pedrosoi, Phialophora verrucosa,
Cladophialophora (Cladosporium) carrionii and Rhinocladiella aquaspersa were
obtained. Partial chemical characterization of these antigenic preparations was
obtained by determination of the levels of total lipids, protein, and
carbohydrates, and identification of the main sterols and carbohydrates. Methylic
antigens presented the highest lipid contents, whereas metabolic antigens showed
the highest carbohydrate content. Total lipid, protein, and carbohydrate levels
were in the range of 2.33 to 2.00 mg/ml, 0.04 to 0.02 mg/ml and 0.10 to 0.02
mg/ml, respectively, in the methylic antigens and in the range of 0. 53 to 0.18
mg/ml, 0.44 to 0.26 mg/ml, and 1.82 to 1.02 mg/ml, respectively, in saline
antigens. Total lipid, protein, and carbohydrate contents were in the range of
0.55 to 0.20 mg/ml, 0.69 to 0.57 mg/ml and 10.73 to 5.93 mg/ml, respectively, in
the metabolic antigens, and in the range of 0.55 to 0.15 mg/ml, 0.62 to 0.20
mg/ml and 3.55 to 0.42 mg/ml, respectively, in the exoantigens. Phospholipids
were not detected in the preparations. Saline and metabolic antigens and
exoantigens presented hexose and the methylic antigen revealed additional pentose
units in their composition. The UV light absorption spectra of the sterols
revealed squalene and an ergosterol fraction in the antigens. The
characterization of these antigenic preparations may be useful for serological
evaluation of patients of chromoblastomycosis.
PMID- 10671288
TI - PCR with Paracoccidioides brasiliensis specific primers: potential use in
ecological studies.
AB - The precise microenvironment of Paracoccidioides brasiliensis has not yet been
discovered perhaps because the methods used are not sensitive enough. We applied
to this purpose the polymerase chain reaction (PCR) using three sets of specific
primers corresponding to two P. brasiliensis genes. This fungus as well as
several other fungi, were grown and their DNA obtained by mechanical disruption
and a phenol chloroform isoamylalcohol-based purification method. The DNA served
for a PCR reaction that employed specific primers from two P. brasiliensis genes
that codify for antigenic proteins, namely, the 27 kDa and the 43 kDa. The lowest
detection range for the 27 kDa gene was 3 pg. The amplification for both genes
was positive only with DNA from P. brasiliensis; additionally, the mRNA for the
27 kDa gene was present only in P. brasiliensis, as indicated by the Northern
analysis. The standardization of PCR technology permitted the amplification of P.
brasiliensis DNA in artificially contaminated soils and in tissues of armadillos
naturally infected with the fungus. These results indicate that PCR technology
could play an important role in the search for P. brasiliensis' habitat and could
also be used in other ecological studies.
PMID- 10671289
TI - Jorge Lobo's disease: experimental inoculation in Swiss mice.
AB - Sixty-four isogenic Swiss mice were intradermically inoculated in both hind foot
pads. The inocula, consisting of fungal suspensions from biopsies obtained from
Jorge Lobo's Disease patients, had the total number of fungi and the viability
index determined using a Neubauer chamber and the fluorescein diacetate-ethidium
bromide technique (FD-EB), respectively. The animals were sacrificed at times
ranging from ten days to eighteen months after inoculation. The cellular
infiltrate, mainly consisting of macrophages containing fungi, increased
progressively up to end of the study; however, no macroscopic alterations were
observed in the inoculated feet. After nine months, small numbers of Langhans'
giant cells started to appear in the infiltrate. A considerable number of fungi
was observed at the end of the experimental period, but only a few were viable
when stained by the FD-EB technique. This fact suggests that there is a
multiplication of fungal cells, which are destroyed by the macrophages but remain
in the tissue for a long time due perhaps to the difficulties in their
elimination. These findings led us to conclude that in spite of the maintenance
of the infection in these animals, Swiss mice cannot be considered an ideal model
to study Jorge Lobo's Disease. However, the authors call attention to the
possibility of other mouse strains being more susceptible to Paracoccidioides
loboi.
PMID- 10671290
TI - Nosocomial infection in long-term care facilities. A survey in a Brazilian
psychiatric hospital.
AB - Nosocomial infection among male patients in a public psychiatric hospital was
studied and the definitions for use in long-term care facilities were employed
for diagnosis. The overall nosocomial infection rate was 6.7 per 1,000 day
inpatients; 55.6% of these infections were identified in the respiratory tract,
50% of them being respiratory viral diseases; 38.9% of the nosocomial infections
involved the eyes, ears, nose, throat and mouth, and 5.6% involved the skin and
soft tissues. The epidemiological characteristics and the main clinical
alterations of these inpatients were also identified.
PMID- 10671291
TI - Gamma (60)Co DL(50/30) of Biomphalaria glabrata (SAY, 1818).
AB - The variation of resistance to (60)Co gamma-rays of Biomphalaria glabrata was
studied. A population of 480 mollusks was observed during 30 days - distributed
in 8 groups of snails isolated and 8 groups of snails in colonies - after
exposure (30 snails per group per dose) to increasing doses of gamma radiation.
Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell (60)Co
irradiator, were applied to the test groups and two groups control (non
irradiated) of snails - isolated and colony - were kept apart. After have been
exposed, the snails were drew back to the aquaria where they were maintained
before. The survival was estimated on a daily score of the alive animals in each
group-dose, starting after the irradiation exposure day. As a result, the
survival self-fertilization forms (DL(50/30) = 218.2 Gy) was found greater than
in cross-fecundation forms. These data point to a low radio-resistance on the
cross-fertilization forms - the sexual reproductive form - which is most found in
nature. The lower radio-resistance of the cross-fertilization forms suggests the
presence of some sex-linked hormonal factor related to this phenomenon.
PMID- 10671292
TI - Listeria monocytogenes in renal transplant recipients.
AB - Five cases of Listeria monocytogenes bacteremia were observed from April to
December 1985, among renal transplant recipients from the same hospital in Sao
Paulo, Brazil. The patients were adults (mean age: 40.6 years), and the basic
complaint was fever, with no report of meningeal syndrome. Laboratory tests
revealed the presence of two serovars, (1/2)a and 4b, which were classified into
three lysotypes. The four strains of serovar 4b showed the same antibiotype, with
resistance to cefoxitin, clindamycin, oxacillin and penicillin.
PMID- 10671293
TI - Flt3 ligand (FL) and its influence on immune reactivity.
AB - Flt3 (fms-like tyrosine kinase 3) ligand (FL) is a potent hematopoietic cytokine
that affects the growth and differentiation of progenitor and stem cells both in
vivo and in vitro. Its capacity to augment strikingly the numbers of dendritic
cells (rare antigen-presenting cells that induce and regulate immune responses)
in mice and humans has stimulated considerable interest in its value as an
investigational tool and therapeutic agent. In this review, we survey the
hematopoietic properties and immunobiology of FL, and examine its therapeutic
potential.
PMID- 10671294
TI - Cloning, characterization and genomic organization of LCC-1 (scya16), a novel
human CC chemokine expressed in liver.
AB - By homology search of expressed sequence tags (EST) in GenBank a novel member of
the CC chemokine family was identified. The full-length sequence of this liver
specific CC chemokine (LCC-1) predicted a mature protein of 97 amino acids with
31-48% identity to other CC chemokines. There was a characteristic amino acid C
term extension when aligned with other chemokines. Northern blot analysis from a
panel of human tissues revealed that LCC-1 mRNA expression is restricted to adult
and fetal liver. Different polyadenylation results in two mRNA species of 1.5 kb
and 0.5 kb in size. LCC-1 is constitutively expressed in human HepG2 hepatoma
cells and is induced by hypoxic exposure. The promoter region of the LCC-1 gene
contains potential HIF-1 binding sites. The EST for LCC-1 has been previously
mapped to the CC chemokine cluster on human chromosome 17q11.2. The organization
of the LCC-1 gene (scya16) into three exons interrupted by two introns is
identical to that found for other members of the CC chemokine family.
PMID- 10671295
TI - Effects of stimulus and cell type on the expression of the -308 tumour necrosis
factor promoter polymorphism.
AB - The authors have previously demonstrated that the tumour necrosis factor (TNF)
308 G/A polymorphism affects the binding of transcription factors. In transient
transfection assays in PMA stimulated U937 monocytes and Jurkat T cells, the A
containing TNF2 promoter has a 2-3-fold greater transcriptional activity than the
TNF1 promoter in the presence of the TNF 3'UTR. In this study it was found that a
difference in TNF1 and TNF2 promoter activities was only observed in U937 and
Jurkat cells, and not in Raji (B cell line), HeLa (epithelial carcinoma cell
line), HepG2 (hepatoma cell line) or THP-1 (monocyte), suggesting cell-type
specific transcription factors or modifications may be involved in the formation
of the -308 protein/DNA complex. Physiological stimulators, TNF and interferon
gamma (IFN-gamma) did not cause differential promoter activity between TNF1 and
TNF2, but LPS did with only the TNF2 promoter/3'UTR construct being significantly
responsive to lipopolysaccharide (LPS) in U937 cells. In U937 cells, the -308
polymorphism affected transcription following differentiation by phorbol
myristate acetate (PMA), retinoic acid, PMA plus LPS and PMA plus retinoic acid
with an increase in nuclear factor binding to both TNF1 and TNF2 in the -323 to
285 region being observed. The greatest difference between TNF2 and TNF1 promoter
activities (5-fold) was observed following PMA plus retinoic acid treatment of
transfected U937 cells for 48h. During this time, U937 differentiated into cells
with a macrophage-like morphology. An understanding of the cell type and stimuli
specific requirements for differential expression of the -308 polymorphism may
help elucidate the role the TNF -308 polymorphism plays in diseases where
elevated TNF levels are thought to be important.
PMID- 10671296
TI - Pseudoexons and regulatory elements in the genomic sequence of the beta
chemokine, alternative macrophage activation-associated CC-chemokine (AMAC)-1.
AB - Recently, the authors reported the cloning of a novel human CC chemokine of
alternatively activated macrophages (AMAC-1), whose expression is induced by Th2
associated cytokines such as interleukin 4 (IL-4), IL-13 and IL-10; vice versa,
AMAC-1 expression is inhibited by Th1-associated cytokines such as interferon
gamma (IFN-gamma). In order to study the genomic organization and transcriptional
regulation of the AMAC-1 gene, genomic clones were isolated by screening a human
lambda genomic library. Sequencing of a clone with a 1.7-kb insert gave a partial
genomic sequence for the AMAC-1 gene. The complete AMAC-1 genomic sequence was
obtained by bioinformational methods and the whole region spanning the AMAC-1
gene was verified by PCR amplification of subfragments and sequencing. The AMAC-1
gene consists of three exons. Whereas exons 2 and 3 were separated by a small
intron of 411 bp, exon 1 and exon 2 were separated by 6 kb of non-translated
genomic sequence containing two pseudoexons that are not expressed although they
feature intact exon/intron boundaries and complete open reading frames. In order
to allow a detailed analysis, a 2.7-kb fragment containing the promoter region
and the first exon of AMAC-1 gene was cloned into a reporter gene construct. In
the AMAC-1 promoter, two possible transcription start points were identified. In
addition, several putative regulatory sequences for IL-4- and IFN-gamma-dependent
transcriptional pathways were found including STAT6 and STAT1 binding sites as
well as several AP-1 and C/EBP elements. Interestingly, a combined STAT6/STAT1
binding element is located in the direct vicinity of the first putative
transcription start point. Competitive binding of IL-4-induced STAT6 versus IFN
gamma-induced STAT1 to this site may explain the antagonistic effects these
cytokines exert on AMAC-1 expression.
PMID- 10671298
TI - Regulated expression of alternate transcripts from the mouse oncostatin M gene:
implications for interleukin-6 family cytokines.
AB - Oncostatin M (OSM) is a member of the IL-6 family of polyfunctional cytokines.
The characterized murine OSM transcript consists of three exons and encodes a
secreted protein. Investigations of mOSM expression using the ribonuclease
protection assay demonstrated novel sites of expression in undifferentiated but
not differentiated pluripotent cells, and revealed the existence of alternatively
spliced mOSM transcripts. cDNAs representing a novel mOSM transcript (mOSM 13)
containing exon 1 spliced directly to exon 3 were isolated from bone marrow using
Rapid Amplification of cDNA Ends (RACE) PCR and RT-PCR approaches. Expression of
the mOSM 13 transcript was regulated in a tissue-specific manner and
independently of mOSM transcript production, suggesting that its production is
biologically significant. Splicing of exon 1 directly to exon 3 disrupts the OSM
open reading frame of mOSM 13. Initiation of translation at sites within exon 3
of mOSM 13 would yield N-terminally truncated OSM proteins that are localized
within the cell. The omission of exon 2 by alternate splicing and the production
of intracellular proteins with alternate biological activities are conserved
among several IL-6 family cytokines and are one manifestation of a more general
phenomenon; the production of alternate cytokine transcripts encoding
intracellular and extracellular proteins.
PMID- 10671297
TI - Tyrosine 462 of the membrane-proximal F'-G' loop of murine Mpl is not essential
for high-affinity binding of thrombopoietin.
AB - The ligand binding site of Mpl, the thrombopoietin (Tpo) receptor, has not been
determined. Tyr(462)of murine Mpl corresponds to Tyr(421)of the common beta chain
of the human IL-3, IL-5 and GM-CSF receptors. Tyr(421)has been identified as
essential for high-affinity ligand binding. To determine whether Tyr(462)is
similarly required for Tpo binding, wild-type murine Mpl (Mpl-WT) or mutant
receptors containing an alanine (Y462A) or lysine (Y462K) in place of
Tyr(462)were expressed in BaF3 cells. In proliferation studies, the Y462A
mutation had no effect on Tpo-induced growth. In contrast, the Y462K mutation led
to an attenuated proliferative response to Tpo. In single-point binding studies,
both Mpl-WT and Y462A cells were able to bind [(125)I]Tpo in a specific manner.
In contrast, there was a marked reduction in binding of [(125)I]Tpo by Y462K
cells. Mpl-WT cells bound Tpo with a K(d)of approximately 330 pM, while Y462A
cells bound Tpo with a K(d)of approximately 268 pM. The binding affinity of Y462K
cells was below that quantifiable by Scatchard analysis. This study suggests that
unlike the corresponding Tyr(421)of the common human beta chain, Tyr(462)of
murine Mpl is not required for high-affinity ligand binding, although it may be
located in proximity to the ligand binding site.
PMID- 10671299
TI - Tumour necrosis factor alpha enhances the expression of hydroxyl lyase,
cytoplasmic antiproteinase-2 and a dual specificity kinase TTK in human
chondrocyte-like cells.
AB - Tumour necrosis factor alpha (TNF-alpha) is a cytokine with pleiotropic effects
on cells ranging from proliferation to apoptosis. These biological effects of TNF
alpha are believed to be elicited by the induction or enhancement of the
expression of TNF-alpha responsive genes in the target cells. TNF-alpha is pro
inflammatory and a principal mediator in the pathogenesis of arthritis. The
activation of an inflammatory cascade by TNF-alpha in arthritis results in the
degradation of cartilage, joint destruction and loss of function. Because TNF
alpha is an important mediator in the pathogenesis of arthritis, the present
study addresses the identification of novel TNF-alpha responsive genes in HTB-94
cell line which is of human origin and maintains a chondrocytic phenotype. The
three identified cDNAs were previously not known to be induced or upregulated by
TNF-alpha in chondrocytes or cells of chondrocytic lineage. One of the identified
cDNAs had sequence similarity to human hydroxyl lyase mRNA (PLOD), an enzyme
involved in collagen biosynthesis and its metabolism; the second cDNA had
sequence similarity to the human cytoplasmic anti-proteinase-2 mRNA (CAP-2), a
member of a group of proteins shown to be associated with protecting cells from
TNF-alpha-induced apoptosis; and the third cDNA had sequence similarity to a dual
specificity kinase, TTK, which is associated with cell proliferation. Relative
gene expression level analysis by PCR and by Northern blotting revealed that
treatment with TNF-alpha enhanced the expression of PLOD, CAP2 and TTK
transcripts which confirmed the results obtained with display gels. Furthermore,
TTK mRNA expression was also induced in human articular chondrocytes treated with
TNF-alpha but not in untreated chondrocytes. Our results suggest that these genes
may play a role in chondrocytic responses to TNF-alpha-mediated stimuli affecting
the cartilage homeostasis.
PMID- 10671300
TI - Soluble glycoprotein 130 (gp130) attenuates OSM- and LIF-induced cartilage
proteoglycan catabolism.
AB - Oncostatin M (OSM) and leukaemia inhibitory factor (LIF) exhibit pleiotropic
biological activities and share many structural and genetic features. The two
cytokines bind with high affinity to the same receptor (LIF/OSM receptor), which
consists of the LIF receptor alpha chain (LIFRalpha) and the signal transduction
unit gp130. A soluble form of the beta chain of the receptor complex called
soluble gp130 (sgp130) has been cloned. In this study, we sought to determine
whether recombinant sgp130 or anti-gp130 Ab could attenuate the resorption of
proteoglycans induced by OSM and LIF in articular cartilage explants. The results
show that at high concentrations sgp130 is capable of attenuating both LIF and
OSM mediated resorption. In contrast, anti-gp130 Ab selectively inhibited the
stimulation of proteoglycan (PG) release by OSM, albeit minimally. The failure of
anti-gp130 to attenuate LIF stimulated PG resorption may be due to the normal
interaction of LIF with LIFRalpha and unfettered heterodimerization of LIFRalpha
with gp130 in the presence of the antibody. The results indicate that sgp130 and
anti-gp130 can modulate cartilage PG metabolism in vitro. Whether sgp130 may have
therapeutic activity in models of arthritis or indeed in arthritic diseases
remains to be determined.
PMID- 10671301
TI - Total serum IL-12 and IL-12p40, but not IL-12p70, are increased in the serum of
older subjects; relationship to CD3(+)and NK subsets.
AB - Interleukin 12 (IL-12), a central cytokine acting on T and natural killer (NK)
cells, directs proliferation of activated T lymphocytes towards a Th1 phenotype.
The heterodimeric molecule IL-12p70, equates with IL-12 biological activity,
while IL-12p40 may antagonize IL-12 and inhibit cytotoxic T lymphocyte (CTL)
generation in vitro. This study characterizes age-related changes in serum total
IL-12, IL-12p70 and IL-12p40 relating them with CD3(+), NK and related subsets
from subjects, aged 30-96 years. Total IL-12, IL-12p40 and the IL-12p40/IL-12p70
ratio, but not IL-12p70, increased significantly with age (P<0.0001). Increases
in total IL-12 and IL-12p40 were negatively associated with CD3(+)(P=0.003,
P=0.002), CD3(+)CD4(+)(P=0.004, P=0.003), CD3(+)CD8(+)(P=0.04;P=0. 04) and
CD4(+)45RA(+)(P=0.0003;P=0.0007) subsets, respectively. Conversely, increases in
IL-12p40 showed a non-significant trend for association with increases in
NK(P=0.07) and a related CD8(+low)CD57(+)(P=0.07) subset. These findings may have
important implications for understanding the functional activity of IL-12 and its
p40 and p70 subunits in vivo and with respect to T-or NK-cell activation in
aging.
PMID- 10671302
TI - Analysis of soluble interleukin 6 receptor in cerebrospinal fluid in inflammatory
and non-inflammatory conditions.
AB - The objective of this study was to investigate the pathophysiological roles of
soluble interleukin 6 receptor (sIL-6R) in cerebrospinal fluid (CSF). CSF was
obtained from patients suspected with meningitis. Eight patients without any
meningeal signs or symptoms were enrolled as controls. An additional 34 CSF
samples were collected to measure both biologically active and immunoreactive sIL
6R. All CSF samples were proven to be aseptic. IL-6 and sIL-6R were measured
using specific ELISAs. Patients were divided into three groups on the basis of
cell number in CSF; inflammatory group (cell number >5 microl, mean 241+/-363.1,
n=61); non-inflammatory group (cell number < or =5 microl, mean=2.1+/-1.7, n=12)
and controls (cell number < or =5 microl, mean=0.3+1.7, n=8). Among these three
groups, the differences in protein (F (2,78)=8.274, P<0.0001) and IL-6
concentration (F (2,78)=6.475, P<0.001) were statistically significant but those
of sIL-6R concentration were not. There were only weak correlations between log
(sIL-6R) versus log (cell number) (r=0.23, P=0.0375), log (protein) (r=0.239,
P=0.0358) and log (IL-6) (r=0.27, P=0.0167). Amounts of immunoreactive and
biologically active sIL-6R were closely correlated (r=0.62, n=34, P<0.005). It
was concluded that sIL-6R is present constitutively in CSF and its level may not
increase significantly in inflammatory conditions; infiltrating cells in CSF are
not the main source of sIL-6R; and sIL-6R in CSF can bind IL-6.
PMID- 10671303
TI - Randomized controlled trial of recombinant human granulocyte-macrophage colony
stimulating factor for the treatment of chronic hepatitis c.
AB - Granulocyte-macrophage colony-stimulating factor (GM-CSF) was administered
subcutaneously to 45 chronic hepatitis C patients, randomly assigned to receive
0.5, 1 or 2 microg GM-CSF/kg b.w. daily/6 weeks (n=30), or no treatment (n=15).
Alanine transaminase (ALT) values normalized in four out of 10 (40%) patients
administered 2 microg GM-CSF [1 cleared hepatitis C virus (HCV) RNA] but in none
given 0.5 or 1 microg or untreated controls (P=0.0079). Following 4 weeks of
rest, patients received 5 million units of interferon (IFN)alpha2b every other
day/6 months, alone (n=30), or combined with 2 microg GM-CSF/daily for 3 months
(n=15). At treatment end, ALT levels in patients administered the combination
normalized more frequently than in those given monotherapy (73% vs 47%, P=0.089).
Viraemia decreased significantly in 11/15 (73%) patients administered GM
CSF/IFNalpha2b combination (mean log HCV RNA copies/ml+/-SEM: 4.13+/-0.40 vs
5.29+/-0.23;P=0.011), and in 20/30 (67%) receiving IFNalpha2b monotherapy (4.27+/
0.28 vs 5. 31+/-0.14;P=0.004); 27% and 20% of patients given the combination and
monotherapy, respectively, cleared HCV RNA. One patient in each regime had a
sustained response after 12 months. 2', 5'-Oligoadenylate synthetase activity (2
5AS) increased during GM-CSF therapy (P=0.033 with the 2 microg dose). 2-5AS
increased more in the GM-CSF/IFN-alpha2b combination than with IFNalpha2b
monotherapy (P<0.02). GM-CSF provoked a skin reaction at the injection site,
accompanied by moderate and reversible rises in eosinophil and leucocyte counts.
In summary, daily s.c. GM-CSF administration is safe and shows effects against
HCV; the GM-CSF/IFNalpha2b combination has an additional-but transient-antiviral
activity in chronic hepatitis C.
PMID- 10671304
TI - Linkage disequilibrium testing of four interleukin-1 gene-cluster polymorphisms
in Danish multiplex families with insulin-dependent diabetes mellitus.
AB - The molecules of the interleukin 1 (IL-1) system have been suggested to play a
role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM), and
polymorphisms in the genes encoding IL-1beta (IL1B), the IL-1 Type 1 receptor
(IL1RTI) and the IL-1 receptor antagonist (IL1RN) molecules have been associated
with IDDM in case-control studies. It can be difficult to exclude selection
biases in case-control studies leading to spurious association. This risk is
eliminated when using the transmission disequilibrium test (TDT). Hence, by means
of the TDT we have investigated four intragenic IL-1 gene-cluster polymorphisms,
the IL1B AvaI, the IL1B TaqI, the IL1RTI PstI and the IL1RN 2(nd)intron
polymorphisms, for linkage and intra-familial association with IDDM in Danish
IDDM multiplex family material comprising 245 families. We found no evidence for
overall linkage or intra-familial association between any of the polymorphisms
and IDDM. In addition, we did not find linkage between any of the polymorphisms
and IDDM in HLA-DR3/4 heterozygous or HLA-non-DR3/4 heterozygous IDDM subjects,
respectively. In conclusion, by means of intra-familial TDT analysis we found no
linkage or intra-familial association between IDDM and the four IL-1 gene-cluster
polymorphisms in Danish IDDM multiplex family material.
PMID- 10671305
TI - Placental cytokine expression in preterm labour and the fetal inflammatory
response.
PMID- 10671306
TI - Gap junctions.
PMID- 10671307
TI - Use of antibodies in the analysis of connexin 43 turnover and phosphorylation.
AB - A series of antipeptide antibodies designed to recognize specific sequences of
the gap junction protein connexin 43 (Cx43) were developed and characterized
immunochemically and immunohistologically. These antibodies bound to gap
junctions and, on Western blots, to 43-kDa (often resolved as a doublet) and 41
kDa proteins in samples from heart, leptomeningeal cells, and brain. Relatively
little of the 41-kDa protein was detectable in heart homogenates. Cultured rat
leptomeningeal cells expressed high levels of the gap junction protein Cx43 and
were used to analyze its turnover and phosphorylation. Pulse-chase experiments in
leptomeningeal cells with [(35)S]methionine indicated that the 41-kDa form of
connexin 43 was the first immunoprecipitable translation product. Radiolabel
subsequently appeared in the lower band of the doublet at 43 kDa, followed by a
shift into the higher band and turnover of the protein with a t(1/2) of 2.7 h.
Pulse-chase labeling with [(32)P]P(i) indicated that phosphorylation of connexin
43 was limited to the 43-kDa protein, with a t(1/2) of 1.7 h. Treatment with
alkaline phosphatase shifted the apparent molecular mass of the 43-kDa protein
doublet such that it comigrated with the 41-kDa form. Hence, the 43-kDa protein
observed on Western blots of both leptomeningeal cells and heart arises by
phosphorylation of the 41 kDa precursor. Phosphorylation of serine residues
accounts for most, if not all, of Cx43 phosphorylation in this system.
PMID- 10671308
TI - Electron crystallographic methods for investigating gap junction structure.
AB - Gap junctions are clusters of closely packed intercellular membrane channels
embedded in the plasma membranes of two adjoining cells. The central pore of the
membrane channels serves as a conduit between cell cytoplasms for molecules less
than 1000 Da in size. Advances in the purification of gap junctions and electron
cryocrystallography and computer reconstruction techniques have produced new
insights into the intercellular channel structure. Methods are described here for
the purification of gap junction membranes, biochemical treatments to produce
hemichannel layers ("split junctions"), assessment of the purity of gap junction
preparations, electron cryomicroscopy, image processing and reconstruction, three
dimensional visualization, and interpretation. The critical step in electron
crystallographic structure determination remains the isolation of crystalline
material in sufficient and pure quantities for recording of electron microscope
images. Along with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and
Western blotting, the quality of gap junction purification is assessed using
electron microscopy of negatively stained preparations. Electron microscopy is
also used to assess the crystallinity of the purified gap junctions and split
junctions. Electron cryocrystallography is a powerful technique for high
resolution structural characterization. Image processing is used to combine and
enhance two-dimensional images. Electron crystallographic analysis is used to
generate a three-dimensional structure from a set of electron micrographs. This
three-dimensional information is extracted from a set of images recorded after
tilting the specimen in the electron microscope stage and recombined using
Fourier analysis techniques analogous to those used in X-ray crystallography.
Computer modeling of the three-dimensional gap junction structures is a useful
tool for analyzing hemichannel docking.
PMID- 10671309
TI - Analysis of connexin intracellular transport and assembly.
AB - Central to understanding the establishment and regulation of gap junction
mediated intercellular communication is a detailed knowledge of how these complex
structures are assembled. In this article, we describe methods to modulate and/or
monitor the transport of connexins from the endoplasmic reticulum to the Golgi
complex and from the trans Golgi network to the cell surface. We also present
techniques that we have developed to assay assembly of newly synthesized connexin
monomers into connexons and gap junctional plaques.
PMID- 10671310
TI - Cell-free synthesis for analyzing the membrane integration, oligomerization, and
assembly characteristics of gap junction connexins.
AB - For gap junction channels to function, their subunit proteins, referred to as
connexins, have to be synthesized and inserted into the cell membrane in their
native configuration. Like other transmembrane proteins, connexins are
synthesized and inserted cotranslationally into the endoplasmic reticulum
membrane. Membrane insertion is followed by their assembly and transport to the
plasma membrane. Finally, the end-to-end pairing of two half-channels, referred
to as connexons, each provided by one of two neighboring cells, and clustering of
the channels into larger plaques complete the gap junction channel formation. Gap
junction channel formation is further complicated by the potential assembly of
homo- as well as heterooligomeric connexons, and the pairing of identical or
different connexons into homo- and heterotypic gap junction channels. In this
article, I describe the cell-free synthesis approach that we have used to study
the biosynthesis of connexins and gap junction channels. Special emphasis is
placed on the synthesis of full-length, membrane-integrated connexins, assembly
into gap junction connexons, homo- as well as heterooligomerization, and
characterization of connexin-specific assembly signals.
PMID- 10671311
TI - Connexin and gap junction degradation.
AB - Many of the subunit proteins (connexins) that form gap junctions are rather
dynamic, with half-lives of only a few hours. Thus, alterations in connexin
turnover and degradation may represent significant mechanisms for the regulation
of intercellular communication. We describe a pharmacological approach to
determining pathways of connexin degradation. Cell cultures are left untreated or
treated with inhibitors of lysosomal or proteasomal proteolysis. Changes in
connexin levels, localization, or decay curves (derived from pulse-chase
experiments) are assessed by immunoblotting, immunofluorescence, and
immunoprecipitation, respectively. Such experiments have provided evidence that
connexin43 degradation involves both the lysosome and the proteasome.
PMID- 10671312
TI - Chemical gating of gap junction channels.
AB - Chemical gating of gap junction channels is a complex phenomenon that may involve
intra- and intermolecular interactions among connexin domains and a cytosolic
molecule (calmodulin?) that may function as channel plug. This article focuses on
the methodology we have employed for studying the molecular basis of chemical
gating by lowered cytosolic pH. Our approach has combined molecular genetics and
biophysics, using exposure to 100% CO(2) for assaying chemical gating efficiency.
Chimeras of connexin 32 (Cx32) and connexin 38 (Cx38) and Cx32 mutants modified
at residues of the cytoplasmic loop, the initial C-terminus domain, or both have
been expressed in Xenopus oocytes, and channel expression and gating have been
tested electrophysiologically by double voltage clamp. In addition, various
channel forms, including homotypic, heterotypic, and heteromeric channel
combinations, have been evaluated for chemical gating sensitivity.
PMID- 10671313
TI - Analysis of connexin phosphorylation sites.
AB - Most connexins, the proteins that form gap junction channels, are
phosphoproteins. Connexin phosphorylation has been thought to regulate gap
junctional protein trafficking, gap junction assembly, channel gating, and
turnover. Connexin phosphorylation has been investigated in a variety of ways.
Some connexins show mobility shifts in sodium dodecyl sulfate-polyacrylamide gel
electrophoresis on phosphorylation. Kinase modulators can change the level of
connexin phosphorylation and affect gap junctional communication levels.
Metabolic labeling of cultured cells has allowed both phosphoamino acid
identification and generation of phosphotryptic peptide maps. However,
identification of the location of phosphorylated residues within the connexin
sequence has required either targeted peptide synthesis, in vitro phosphorylation
of known sites, and two-dimensional comigration studies or liquid chromatographic
separation and N-terminal sequencing of peptides. In addition to these
conventional methods, we discuss new applications of mass spectrometry to the
identification of phosphorylated peptides and the specific residues
phosphorylated within the connexin-derived peptide.
PMID- 10671314
TI - General or cell type-specific deletion and replacement of connexin-coding DNA in
the mouse.
AB - Here we describe several gene targeting approaches currently used in our
laboratory for the generation of deletion or replacement mutants of connexin
genes in the mouse and discuss the advantage of the double-replacement strategy
for the generation of conditional mutants. For the analysis of complementary
functions of connexins, it will be necessary to generate mice with mutations in
several connexin genes. We also report how this can be effectively accomplished.
The replacement of targeted connexin-coding DNA with a reporter gene, to mimic
expression of the deleted gene product, is currently being used in several
laboratories. The use of different reporter genes or their differently localized
gene products could allow distinction of promoter activity in double or triple
connexin mutant mice.
PMID- 10671315
TI - Identification of connexin-interacting proteins: application of the yeast two
hybrid screen.
AB - Protein-protein interactions are recognized as one of the fundamental mechanisms
for relaying the intra- and intercellular signals that are required for normal
cellular activities affecting growth, development, and maintenance of homeostasis
in tissues and organs. The yeast two-hybrid screen has become a valuable tool for
identifying protein-protein interactions. The gap junction protein connexin 43
(Cx43) has been implicated in a number of biological processes including
development and cellular growth control. To further advance our understanding of
the ways in which Cx43 may influence these cellular activities, and to extend our
knowledge of the regulation of Cx43 function and/or processing, we have employed
the yeast two-hybrid screen technique to identify Cx43-interacting proteins. We
present detailed methods for the yeast two-hybrid screen of a mouse embryonic
cDNA library using the C terminus of Cx43 as "bait." We also describe additional
methods to confirm the interactions between Cx43 and the identified proteins.
These methods include in vitro binding assays, coimmunoprecipitation, and
subcellular localization using immunofluorescence microscopy.
PMID- 10671316
TI - Probing the function of connexin channels in primary tissues.
AB - Connexin channels provide for a widespread mechanism of cell-to-cell cross-talk
within primary tissues, which is mediated by intercellular exchanges of
cytoplasmic ions and molecules. Experimental and clinical studies have recently
provided evidence that these exchanges are most likely to play multiple roles,
which are critical for the proper development and function of primary tissues.
There is also increasing evidence that major clinical disorders may result when
the formation and function of connexin channels are altered. Still, the
physiological functions that the cell-to-cell communication mediated by connexin
channels subserve in most primary tissues are still uncertain. Here, I review two
approaches that may aid in identifying these specific functions.
PMID- 10671317
TI - Gap junctions and the regulation of cellular functions of stem cells during
development and differentiation.
AB - In multicellular organisms, the role of gap junction intercellular communication
(GJIC) in the regulation of cell proliferation, cell differentiation, and
apoptosis is becoming increasingly recognized as one of the major cellular
functions from the start of the fertilized egg, through normal development of the
embryo and fetus, to the sexual maturation of the adult and ultimately to the
maintenance of health of the aging adult. Given that the function of this
membrane-associated protein channel is to synchronize electrotonic or metabolic
functions, differential regulation of function at the transcriptional,
translational, and posttranslational levels of a family of highly evolutionarily
conserved genes (connexins) needs to be considered. Both inherited mutations and
environmental modulation of GJIC could, in principle, affect the function of gap
junctions to control cell proliferation, cell differentiation, and apoptosis,
thereby leading to a wide variety of pathologies. We review a few techniques used
to characterize the ability of stem and progenitor cells to perform GJIC.
PMID- 10671318
TI - Immunohistochemical analysis of cerebral cortical and vascular lesions in the
primate Microcebus murinus reveal distinct amyloid beta1-42 and beta1-40
immunoreactivity profiles.
AB - Recent reports have shown that amyloid beta deposits in the brains of Alzheimer's
disease patients consist mainly of two distinct species of amyloid beta protein
(Abeta) with different C-termini, Abeta1-42 (Abeta42) and Abeta1-40 (Abeta40).
The nature of the Abeta species in Microcebus murinus brain was investigated
immunocytochemically using polyclonal antibodies with clear specificity for the
Abeta42 and Abeta40 C-termini. The cortical vascular deposits were immunopositive
for both Abeta42 and Abeta40. However, most of the diffuse plaques were strongly
positive for Abeta42 whereas only a subset of deposits were positive for Abeta40.
Numerous cortical plaques were Abeta42-immunopositive but tested negative for
Abeta40. This suggests that Abeta42 is probably associated with early stages of
plaque maturation. This neuropathological feature reminiscent of that observed in
brains affected by Alzheimer's disease further supports the idea that M. murinus
could be used as a potential model of the early stages of this neurological
disease.
PMID- 10671319
TI - Behavioral disturbances without amyloid deposits in mice overexpressing human
amyloid precursor protein with Flemish (A692G) or Dutch (E693Q) mutation.
AB - The contribution of mutations in the amyloid precursor protein (APP) gene known
as Flemish (APP/A692G) and Dutch (APP/E693Q) to the pathogenesis of Alzheimer's
disease and hereditary cerebral hemorrhage with amyloidosis of the Dutch type,
respectively, was studied in transgenic mice that overexpress the mutant APP in
brain. These transgenic mice showed the same early behavioral disturbances and
defects and increased premature death as the APP/London (APP V717I), APP/Swedish
(K670N, M671L), and other APP transgenic mice described previously. Pathological
changes included intense glial reaction, extensive microspongiosis in the white
matter, and apoptotic neurons in select areas of the brain, while amyloid
deposits were absent, even in mice over 18 months of age. This contrasts with
extensive amyloid deposition in APP/London transgenic mice and less pronounced
amyloid deposition in APP/Swedish transgenic mice generated identically. It
demonstrated, however, that the behavioral deficiencies and the pathological
changes in brain resulting from an impaired neuronal function are caused directly
by APP or its proteolytic derivative(s). These accelerate or impinge on the
normal process of aging and amyloid deposits per se are not essential for this
phenotype.
PMID- 10671320
TI - Oxidative insults are associated with apolipoprotein E genotype in Alzheimer's
disease brain.
AB - The epsilon4 allele of the apolipoprotein E gene (APOE) is associated with
sporadic and familial late-onset Alzheimer's disease (AD). Oxidative stress is
believed to play an important role in neuronal dysfunction and cell death in AD.
We now provide evidence that in the hippocampus of AD, the level of
thiobarbituric acid-reactive substances (TBARS) and the APOE genotype are linked.
Within AD cases, the levels of TBARS were found to be higher among epsilon4
carriers while the apoE protein concentrations were lower. The relationship
between the levels of TBARS and apoE proteins was corroborated by the results
from the APOE-deficient mice, in which the levels of TBARS were higher than those
in wild-type mice. Among AD cases, tissues from patients with the epsilon4 allele
of APOE displayed lower activities of catalase and glutathione peroxidase and
lower concentration of glutathione than tissues from patients homozygous for the
epsilon3 allele of APOE. Together these data demonstrate that, in AD, the
epsilon4 allele of APOE is associated with higher oxidative insults.
PMID- 10671321
TI - BDNF blocks caspase-3 activation in neonatal hypoxia-ischemia.
AB - Hypoxic-ischemic (H-I) injury to the brain in the perinatal period often leads to
significant long-term neurological deficits. In a model of neonatal H-I injury in
postnatal day 7 rats, our previous data have shown that cell death with features
of apoptosis is prominent between 6 and 24 h after H-I and that neurotrophins,
particularly BDNF, can markedly protect against tissue loss. During brain
development, caspase-3 is required for normal levels of programmed cell death.
Utilizing an antibody specific for the activated form of caspase-3, CM1, we now
show that caspase-3 is specifically activated in neuronal cell bodies and their
processes beginning at 6 h and peaking 24 h following unilateral carotid ligation
and exposure to hypoxia in postnatal day 7 rats. Caspase-3 activation began to
occur in cortex at 6 h and in striatum and hippocampus at 12-18 h. Caspase-3
activation was also observed in developing oligodendrocytes.
Intracerebroventricular injection of BDNF prior to H-I injury almost completely
abolished evidence of H-I-induced caspase-3 activation in vivo. Utilizing a
specific molecular marker of an apoptotic pathway, these findings demonstrate
that H-I injury to the developing brain is a strong apoptotic stimulus leading to
caspase-3 activation, that BDNF can block this process in vivo, and that the
ability of BDNF to inhibit caspase activation and subsequent apoptosis likely
accounts in large part for its protection against neuronal injury in this model.
PMID- 10671322
TI - Enhanced synaptic potentiation in transgenic mice expressing presenilin 1
familial Alzheimer's disease mutation is normalized with a benzodiazepine.
AB - Mutations in presenilin 1 (PS1) are the most common causes of familial
Alzheimer's disease (FAD). We examined synaptic physiology in hippocampal brain
slices of transgenic mice expressing the FAD-linked PS1 deletion of exon 9
variant. Basal excitatory transmission and paired-pulse facilitation in PS1
mutant mice were unchanged. Short- and long-term potentiation of excitatory
transmission following high-frequency stimulation were greater in transgenic mice
expressing mutant PS1. Mutants had enhanced synaptic inhibition, which may be a
compensatory change offsetting an abnormally sensitized plasticity of excitatory
transmission. Increasing inhibitory transmission in mutant animals even more with
a benzodiazepine reverted synaptic potentiation to the levels of controls. These
results support the potential use of benzodiazepines in the treatment of familial
Alzheimer's disease.
PMID- 10671323
TI - New uses for new and old quinolones and the challenge of resistance.
PMID- 10671324
TI - Neutropenia, neutrophil dysfunction, and bacterial infection in patients with
human immunodeficiency virus disease: the role of granulocyte colony-stimulating
factor.
AB - Neutropenia frequently complicates infection due to human immunodeficiency virus
(HIV). The etiology of neutropenia in this setting includes bone marrow infection
or infiltration, myelosuppressive therapies, the presence of antibodies to HIV,
and accelerated apoptosis. Protection against microbial invaders by neutrophils
is further compromised by impaired chemotaxis and phagocytosis, production of
toxic oxygen species, and expression of cellular adhesion molecules. Neutropenia
is a significant risk factor for bacterial infection in HIV-infected patients.
Endogenous cytokines, such as granulocyte colony-stimulating factor (G-CSF) and
granulocyte-macrophage colony-stimulating factor, regulate neutrophil count and
function. Treatment with recombinant human methionyl G-CSF (filgrastim) has
lessened neutropenia in patients with HIV infection. Clinical trials have shown
that the incidence of bacterial infections and the number of consequent days of
hospitalization for HIV-infected patients receiving filgrastim therapy are lower.
Filgrastim treatment also allows administration of larger doses of
myelosuppressive agents.
PMID- 10671325
TI - Herpes simplex virus type 2 shedding in human immunodeficiency virus-negative men
who have sex with men: frequency, patterns, and risk factors.
AB - We investigated the frequency, site, and risk factors for herpes simplex virus
(HSV) shedding in 30 human immunodeficiency virus (HIV)-negative HSV type 2 (HSV
2)-seropositive men who have sex with men. Subjects collected daily HSV culture
samples from genital, perianal, and oral areas for 100 days and maintained
diaries of signs and symptoms. Sixteen men (53.3%) shed HSV-2, and 9 (56.3%) of
16 men who were also HSV type 1 (HSV-1)-seropositive shed HSV-1. Overall, HSV-2
was isolated on 3.1% of the days; 68% of the isolations were on days that lesions
did not occur. HSV-2 shedding was predominantly perianal (83.3%). HSV-1 was
isolated on 2.1% of the days; 23 of 24 HSV-1 isolates were from oral areas. Rates
of perianal or genital shedding were 6.6% on the days that participants reported
prodromal symptoms and 1.9% on the days that participants did not report
prodromal symptoms (P<.001). Men seropositive for both HSV-1 and HSV-2 were
significantly more likely to shed HSV-2 (odds ratio, 4.1; 95% confidence
interval, 1.4-11.9) than were HSV-2-seropositive men. HSV-2-seropositive men who
have sex with men have frequent subclinical HSV-2 shedding, usually from the
perianal area, and more frequent prodromal HSV-2 shedding.
PMID- 10671326
TI - Asymptomatic herpes simplex virus shedding and Russian roulette.
PMID- 10671327
TI - Risk factors for radial artery harvest site infection following coronary artery
bypass graft surgery.
AB - Radial arteries increasingly are used during coronary artery bypass graft (CABG)
surgery. Although risk factors for saphenous vein harvest site infection (HSI)
have been reported, rates of and risk factors for radial artery HSI are not well
established. We compared rates of radial artery HSI that were detected by 2
surveillance methods, regular and heightened. Risk factors were determined by a
case-control study. We identified 35 radial artery HSIs ("case sites") in 26 case
patients. The radial artery HSI rate was significantly higher during heightened
surveillance than during routine surveillance (12.3% vs. 3.1%, respectively;
P=.002). Multivariate analysis showed that diabetes mellitus with a preoperative
glucose level >/=200 mg/dL (odds ratio [OR], 4.4; P=. 01) and duration of surgery
>/=5 h (OR, 3.1; P=.02) were independent risk factors for radial artery HSI.
Infection is a common complication of radial artery harvesting for CABG surgery,
and infection rates are dependent on the intensity of surveillance. We identified
preoperative hyperglycemia and surgery duration as independent risk factors for
radial artery HSI.
PMID- 10671328
TI - Invasive disease due to group B Streptococcus in pregnant women and neonates from
diverse population groups.
AB - From 1993 through 1996, surveillance for invasive disease due to group B
Streptococcus (GBS) in neonates aged <7 days and in peripartum pregnant women was
performed in a racially and ethnically diverse cohort in 4 cities in the United
States. In a birth population of 157,184, 130 neonatal cases (0.8 per 1000) and
54 maternal cases (0.3 per 1000) were identified. Significant correlates with
neonatal disease were black or Hispanic race and a birth weight <2500 g. The
attack rate for peripartum maternal infection varied widely by city and may have
been influenced by the frequency of administration of intrapartum antibiotics or
of evaluating febrile women by performance of blood cultures. Pregnancy loss or
GBS disease in the infant occurred in 28% of these maternal cases. Among neonatal
and maternal GBS isolates, serotypes Ia (34%-37%) and III (25%-26%) predominated,
and type V was frequent (14%-23%). These results provide a description of
invasive GBS perinatal infection during the period in which guidelines for
prevention were actively disseminated.
PMID- 10671329
TI - A 5-year review of recurrent group B streptococcal disease: lessons from twin
infants.
AB - Recurrent invasive disease due to group B Streptococcus (GBS) in twin infants has
not been reported. We report 2 cases of recurrent GBS afflicting both siblings of
a set of dichorionic twin infants. The maternal and infant colonizing and
invasive strains were identical by serotyping and pulsed-field gel
electrophoresis (PFGE). Despite attempts at eradication with different antibiotic
regimens, the infants remained colonized after treatment of the second episode. A
5-year review of recurrent invasive GBS disease in infants in our affiliated
hospitals was undertaken, and 6 further cases were identified. Serotyping and
PFGE of isolates from initial and second episodes were genotypically identical
for each case. Three infants each had GBS serotype Ia or V disease and 2 had GBS
serotype III disease. The exact pathogenesis of recurrent GBS disease remains
unclear, but our data support the hypothesis that persistent mucosal colonization
with the original GBS strain rather than new acquisition is a pivotal factor in
disease recurrence.
PMID- 10671330
TI - Early results (at 6 months) with intermittent clarithromycin-including regimens
for lung disease due to Mycobacterium avium complex.
AB - We initiated a prospective noncomparative trial of treatment for lung disease due
to Mycobacterium avium complex (MAC) in human immunodeficiency virus-negative
patients, with a regimen of clarithromycin (1000 mg), rifabutin (300-600 mg), and
ethambutol (25 mg/kg) administered 3 times per week. Fifty-nine patients were
enrolled. Twelve (20%) were lost to follow-up, and 6 (10%) developed
clarithromycin intolerance. The remaining 41 patients (69%) completed the initial
6 months of therapy. The sputum of 32 of these patients (78%) converted to
negative. When results were compared with the sputum response rates at 6 months
in previous studies with a regimen including daily clarithromycin and regimens
including intermittent (3 times per week) azithromycin with the same companion
drugs, no differences in treatment responses were evident. Adverse reactions
related to rifabutin were a major problem, and for 24 (41%) of 59 patients the
dosage was decreased or the drug was withdrawn. Intermittent (3 times per week)
administration of clarithromycin appears to be as effective as daily
administration in effecting sputum conversion in pulmonary MAC disease.
PMID- 10671331
TI - A population-based survey of tuberculosis symptoms: how atypical are atypical
presentations?
AB - There is scant information on tuberculosis symptoms from a population-based
perspective. We prospectively identified 526 tuberculosis cases reported in Los
Angeles County over a 6-month period. Of 313 persons who completed our
questionnaire, 72.7% had cough, 48.2% for >2 weeks, and 52.3% had fever, 29.4%
for >2 weeks. Among those with pulmonary disease, only 52.4% had cough for >2
weeks. In a multivariate model, persons with significant symptoms typical of
tuberculosis disease (defined as cough or fever for >2 weeks, weight loss, or
hemoptysis) were associated with lack of medical insurance, negative tuberculin
skin test, diagnosis during a process other than screening, and non-Asian race.
In summary, classic symptoms of prolonged cough and fever are insensitive
predictors of tuberculosis. Our data suggest that Asians may need to be added to
the list of persons who present with tuberculosis atypically. We believe that the
Infectious Diseases Society of America guidelines for community-acquired
pneumonia should emphasize demographic features in addition to clinical symptoms
when suggesting which patients require evaluation for Mycobacterium tuberculosis.
PMID- 10671332
TI - A double-blind, randomized, placebo-controlled trial of itraconazole capsules as
antifungal prophylaxis for neutropenic patients.
AB - To evaluate the efficacy of itraconazole capsules in prophylaxis for fungal
infections in neutropenic patients, we conducted a prospective, double-blind,
placebo-controlled, randomized trial. Patients with hematologic malignancies or
those who received autologous bone marrow transplants were assigned either a
regimen of itraconazole (100 mg orally twice daily; n=104) or of placebo (n=106).
Overall, fungal infections (superficial or systemic) occurred more frequently in
the placebo group (15% vs. 6%; P=.03). There were no differences in the empirical
use of amphotericin B or systemic fungal infections. Among patients with
neutropenia that was profound (<100 neutrophils/mm3) and prolonged (for at least
7 days), those receiving itraconazole used less empirical amphotericin B (22% vs.
61%; P=.0001) and developed fewer systemic fungal infections (6% vs. 19%; P=.04).
For patients with profound and prolonged neutropenia, itraconazole capsules at
the dosage of 100 mg every 12 h reduce the frequency of systemic fungal
infections and the use of empirical amphotericin B.
PMID- 10671333
TI - A prospective search for ocular lesions in hospitalized patients with significant
bacteremia.
AB - The purpose of this study was to determine the prevalence, risk factors, and
prognostic value of ocular lesions in unselected patients with bacteremia. A
total of 202 bacteremic patients, 101 nonbacteremic septic patients, and 90
nonseptic control patients were compared in a prospective, controlled,
observational study. Ocular lesions related to bacteremia were found in 12% of
the bacteremic group, 5% of the septic group, and 2% of the control group. Ocular
lesions were significantly more frequent in the bacteremic patients than in the
control patients (P=.007). The severity of the clinical condition and the
presence of fungemia predict independently a higher risk of ocular lesions.
Mortality rates among bacteremic patients with and without ocular lesions were,
respectively, 32% and 8% (P<.01; OR, 3.99). The asymptomatic nature of most
ocular lesions in patients with bloodstream infections and the impossibility of
amelioration in most cases lead us to recommend ophthalmologic examination for
bacteremic patients only when prognostic information is needed.
PMID- 10671335
TI - An outbreak of Streptococcus pneumoniae serotype 1 in a closed community in
southern Israel.
AB - An outbreak of Streptococcus pneumoniae serotype 1 occurred in a closed community
that was characterized by poverty and crowding. Vaccine was administered to
individuals aged >2 years; no new cases occurred among vaccine recipients. Six
weeks after vaccination, carriage of serotype 1, but not of other serotypes,
decreased 8.8-fold. This suggests that the reduction in serotype 1 carriage
reflects the natural course of the outbreak rather than a vaccine effect.
Polysaccharide vaccine may be helpful in terminating pneumococcal outbreaks but
may not affect pneumococcal carriage.
PMID- 10671334
TI - Combination therapy with amprenavir, abacavir, and efavirenz in human
immunodeficiency virus (HIV)-infected patients failing a protease-inhibitor
regimen: pharmacokinetic drug interactions and antiviral activity.
AB - Patients with plasma viral RNA >50,000 copies/mL, despite a protease-inhibitor
regimen, received abacavir, amprenavir, and efavirenz to assess efavirenz
amprenavir drug interactions and to evaluate safety and antiviral response.
Patients first received amprenavir with abacavir and other nucleoside analogs.
Amprenavir levels were measured before and after adding efavirenz. Patients then
received a second protease inhibitor. There was evidence of genotypic and
phenotypic resistance at study entry. No patient had study drugs discontinued
because of toxicity. Efavirenz decreased the steady-state area under the curve,
maximum plasma concentration, and minimum plasma concentration of amprenavir by
24%, 33%, and 43%, respectively. Three of 10 patients had >1.5 log10 viral
response to abacavir and amprenavir. All 8 patients who added efavirenz had >0.5
log10 decline in viral load, and this response lasted >24 weeks for 3 of the
patients. A combination regimen that included abacavir, amprenavir, and efavirenz
was well tolerated and had sustained activity in some patients. Concomitant
efavirenz therapy decreases amprenavir concentrations.
PMID- 10671336
TI - Methicillin-resistant Staphylococcus aureus: the other emerging resistant gram
positive coccus among liver transplant recipients.
AB - We undertook a study of the characteristics and clinical impact of infections due
to methicillin-resistant Staphylococcus aureus (MRSA) after liver
transplantation. Of 165 patients who received liver transplants at our
institution from 1990 through 1998, 38 (23%) developed MRSA infections. The
predominant sources of infection were vascular catheters (39%; n=15), wound (18%;
n=7), abdomen (18%; n=7), and lung (13%; n=5). A significant increase in MRSA
infections (as a percentage of transplant patients infected per year) occurred
over time (P=.0001). This increase was greater among intensive care unit patients
(P=.001) than among nonintensive care unit hospital patients (P=.17).
Cytomegalovirus seronegativity (P=.01) and primary cytomegalovirus infection were
significantly associated with MRSA infections (P=.005). Thirty-day mortality
among patients with MRSA infections was 21% (8/38). Mortality was 86% in patients
with bacteremic MRSA pneumonia or abdominal infection and 6% in those with
catheter-related bacteremia (P=.004). Thus the incidence of MRSA infection has
increased exponentially among our liver transplant recipients since 1990. These
infections have unique risk factors, time of onset, and a significant difference
in site-specific mortality; deep-seated bacteremic infections, in particular,
portend a grave outcome.
PMID- 10671337
TI - Molecular epidemiology of Blastomyces dermatitidis.
AB - The inhalation of conidia of Blastomyces dermatitidis, a fungus found in soil,
causes disease in humans and animals. We studied the genetic diversity of this
pathogen by extracting DNA yeasts and analyzing them with a polymerase chain
reaction (PCR)-based typing system we developed, which used restriction fragment
analysis of amplicons from the regions between the rDNA repeats and allowed us to
class isolates into 3 major groups. Strains were further differentiated by use of
PCR fingerprinting with 3 different primers. Fifty-nine isolates collected over
35 years from 15 regions (United States, India, Africa, Canada) were analyzed.
Genotypic groups A, B, and C contained 17, 23, and 19 isolates, which were
divided into 5, 15, and 12 types, respectively. All 16 isolates from North
America in group A were from the upper midwestern United States or Canada,
whereas 0 of 20 isolates from the southeastern United States were in group A.
Studies of the largest collection from 1 locale (Eagle River, WI), revealed that
the soil isolates studied were not responsible for the majority of cases in this
outbreak, as previously proposed, and that >1 strain was present in the
environment and in patients. Overall, these results provide a tool for the
epidemiological study of blastomycosis and illuminate the genetic and geographic
diversity of this important pathogen.
PMID- 10671338
TI - Bicuspid aortic valve--A silent danger: analysis of 50 cases of infective
endocarditis.
AB - We analyzed 50 cases of bicuspid aortic valve endocarditis in patients who
presented to St. Thomas' Hospital from 1970 through 1998. These represented 12.3%
of the 408 cases of native valve endocarditis (NVE). All patients were male, and
their mean age was 39 years. Forty-five of the 50 cases were pathologically
proven; 47 were clinically definite according to the Duke criteria and 49
according to our modifications of the Duke criteria. Viridans streptococci and
staphylococci accounted for 72% of cases. The prevalences of clinical features
were similar to those seen in NVE: fever (temperature >/=38 degrees C, 74%) and
malaise (70%), although dyspnea was more frequent (36%). There was a high
incidence of serious complications (72% heart failure; 30% periannular
abscesses). Surgery was required during the initial admission in 82% of cases.
Overall mortality was 14%, and surgical mortality was 9%. Few patients knew they
had a "heart condition," and a bicuspid aortic valve was detected in only 35% of
echocardiograms performed before surgery.
PMID- 10671339
TI - Granulocyte-macrophage colony-stimulating factor as immunomodulating factor
together with influenza vaccination in stem cell transplant patients.
AB - The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the
serological response at influenza vaccination was studied in 117 patients who had
undergone stem cell transplantation (SCT). The vaccine response was evaluated as
significant increases in levels of influenza hemagglutination-inhibition (HAI)
antibodies and of IgG antibodies measured by enzyme-linked immunosorbent assay
(ELISA). There was no difference in antibody response to either influenza A or B
in 64 patients who received GM-CSF at vaccination, compared with the 53 who did
not. In the subgroup of allogeneic SCT patients, HAI showed that the response
rate to the influenza B vaccine was significantly higher in the treatment group
(P<.05). ELISA showed that autologous SCT patients with breast cancer who
received GM-CSF had a better response to influenza A (P<.05) and B (P<.01). At
early vaccination, 4-12 months after stem cell transplantation, these responses
were more pronounced. GM-CSF appears to improve the response to influenza
vaccination in some groups of SCT patients, but only to a limited extent.
PMID- 10671340
TI - Hyphal forms in the central nervous system of patients with coccidioidomycosis.
AB - Coccidioides immitis is a dimorphic fungus that grows as a filamentous mold in
soil and as a spherule at human body temperature. The hyphal or soil form is
found rarely in human tissue. We report 5 cases of coccidioidomycosis in which
hyphae were found in brain tissue or spinal fluid. The presence of central
nervous system plastic devices appears to be associated with morphological
reversion to the saprophytic form. This reversion has implications for diagnosis
and therapy and may increase the risk of obstruction of the device(s).
PMID- 10671341
TI - Nosocomial transmission of Mycobacterium bovis bacille Calmette-Guerin to
children receiving cancer therapy and to their health care providers.
AB - A previous report of nosocomial infection due to Mycobacterium bovis bacille
Calmette-Guerin (BCG) implicated contamination of chemotherapy solutions
reconstituted under the same biosafety hood as BCG vaccine used for bladder
cancer therapy. We report 3 similar BCG infections in children and describe
evidence of respiratory transmission to health care workers (HCWs) from 1
patient. These children were receiving chemotherapy for leukemia when they
presented with active tuberculosis. Each isolate was identified biochemically and
by both gas-liquid chromatography and major polymorphic tandem repeat-polymerase
chain reaction. Pulsed-field gel electrophoresis showed that 2 isolates were
identical strains and identical to the Tice and Connaught strains licensed in the
United States for bladder chemotherapy. The third isolate differed by a single
fragment after DraI restriction. One patient with heavily positive sputum exposed
numerous HCWs. Of 41 HCWs, 2 (5%) converted their purified protein derivatives
(PPD) skin test. These data underscore the risk of nosocomial BCG transmission by
contamination of chemotherapy solutions and demonstrate the potential for
transmission to HCWs from patients with active pulmonary disease.
PMID- 10671342
TI - Herpes simplex virus DNA in amniotic fluid without neonatal infection.
AB - Twenty-one pregnant women were studied to determine the distribution of herpes
simplex virus (HSV): 10 had symptomatic genital herpes, including 1 with primary
cervical HSV infection, and 11 had asymptomatic genital herpes. Samples from
vesicles, the cervix, and amniotic fluid (AF) were analyzed with 2 separate
polymerase chain reaction (PCR) tests and with viral culture. For newborns,
clinical examinations and pharyngeal HSV cultures were performed, and cord blood
IgM antibodies to HSV were measured. HSV DNA was present in the AF of 3 women
with symptomatic HSV infection, but all cultures were negative. HSV was detected
more often with PCR than with culture, in both vesicle and cervical samples. For
the asymptomatic group, all AF samples were negative, whereas 4 cervical samples
were positive by PCR (none were positive by culture). All isolates were HSV type
2. All infants were healthy, and none had cord blood IgM antibodies to HSV,
including those with PCR-positive AF.
PMID- 10671343
TI - Pathogenic significance of methicillin resistance for patients with
Staphylococcus aureus bacteremia.
AB - To assess whether methicillin resistance is a microbial characteristic associated
with deleterious clinical outcome, we performed a cohort study on 908 consecutive
episodes of Staphylococcus aureus bacteremia and a case-control study involving
163 pairs of patients matched for preexisting comorbidities, prognosis of the
underlying disease, length of hospitalization, and age. Of 908 bacteremic
episodes, 225 (24.8%) were due to methicillin-resistant S. aureus (MRSA).
Multivariate analysis did not reveal that methicillin resistance was an
independent predictor for mortality when shock, source of bacteremia, presence of
an ultimately or rapidly fatal underlying disease, acquisition of the infection
in an intensive care unit (ICU), inappropriate empirical therapy, female sex, and
age were taken into account. Nonetheless, methicillin resistance was an
independent predictor for shock. The case-control study could not confirm that
shock was linked to MRSA when prior antimicrobial therapy, inappropriate
treatment, ICU residence, and female sex were considered. Our data suggest that
cohort studies tend to magnify the relationship of MRSA with clinical markers of
microbial pathogenicity and that this effect is a shortcoming of these kind of
studies that is caused by inadequate control for underlying diseases.
PMID- 10671344
TI - Right-side endocarditis in injection drug users: review of proposed mechanisms of
pathogenesis.
AB - Infective endocarditis of the right-side heart valves occurs commonly in
injection drug users. Although a variety of hypotheses have been put forward to
explain this clinical observation, no single hypothesis is adequate. In this
article, basic scientific, clinical, and microbiological data on this topic are
presented. It is apparent that no clear unifying mechanism emerges to explain the
well-documented clinical predilection for the infection of the right-side heart
valves in this population. Further investigation of this topic utilizing large
international clinical registries may help to clarify matters further.
PMID- 10671345
TI - Detection of Legionella DNA in peripheral leukocytes, serum, and urine from a
patient with pneumonia caused by Legionella dumoffii.
AB - The polymerase chain reaction (PCR) has been used to detect Legionella DNA in
respiratory tract, serum, and urine samples from patients with pneumonia. In
addition, a preliminary study using a guinea pig model suggested that testing of
peripheral leukocytes by PCR may be more sensitive than testing of other samples.
We used PCR to detect Legionella DNA in serial peripheral leukocyte (buffy coat),
serum, and urine samples from a patient with pneumonia caused by Legionella
dumoffii. Legionella DNA was detected in all 3 sample types when first collected.
Buffy coat and urine samples remained positive up to 56 days after the onset of
symptoms, whereas serum samples were positive from 10 up to 16 days after the
onset of symptoms. Sequencing of PCR amplicons indicated the presence of L.
dumoffii DNA in positive samples. It appears that buffy coat may be a useful
sample to test for Legionella DNA, but further study is required to determine the
precise sensitivity and to make comparisons with other sample types.
PMID- 10671346
TI - Sustained bacteremia associated with transjugular intrahepatic portosystemic
shunt (TIPS).
AB - Transjugular intrahepatic portosystemic shunt (TIPS) has become a routine
procedure in patients with portal hypertension, yet there are few data concerning
the incidence of bacteremia associated with this shunt. All patients who
underwent TIPS placement at a university hospital from January 1992 through
January 1999 were studied. Ninety-nine TIPS were placed, and 10 patients
subsequently developed sustained bacteremia; 5 patients had no identifiable
source of bacteremia despite rigorous evaluation and were presumed to represent
TIPS infections, for an estimated annual incidence of 7 cases/1000 TIPS
procedures. Case patients developed bacteremia a median of 100 days after TIPS
placement (range, 6-732 days). Bacteremia resolved in all patients after
treatment with appropriate intravenous antibiotics (median, 2 weeks of therapy).
Although the incidence of TIPS-associated bacteremia appears low, the increasing
frequency of this procedure suggests that more information is needed to define
this entity and to develop appropriate treatment recommendations.
PMID- 10671347
TI - Nose blowing propels nasal fluid into the paranasal sinuses.
AB - Intranasal pressures were measured in adults during nose blowing, sneezing, and
coughing and were used for fluid dynamic modeling. Sinus CT scans were performed
after instillation of radiopaque contrast medium into the nasopharynx followed by
nose blowing, sneezing, and coughing. The mean (+/-SD) maximal intranasal
pressure was 66 (+/-14) mm Hg during 35 nose blows, 4.6 (+/-3.8) mm Hg during 13
sneezes, and 6.6 (+/-3.8) mm Hg during 18 coughing bouts. A single nose blow can
propel up to 1 mL of viscous fluid in the middle meatus into the maxillary sinus.
Sneezing and coughing do not generate sufficient pressure to propel viscous fluid
into the sinus. Contrast medium from the nasopharynx appeared in >/=1 sinuses in
4 of 4 subjects after a nose blow but not after sneezing or coughing.
PMID- 10671348
TI - Residual low-level viral replication could explain discrepancies between viral
load and CD4+ cell response in human immunodeficiency virus-infected patients
receiving antiretroviral therapy.
AB - We report the evolution of chronic infection with human immunodeficiency virus
type 1 (HIV-1) in a patient treated with stavudine plus didanosine, whose CD4+
lymphocyte count progressively decreased, despite a sustained plasma viral load
<20 copies/mL. After 12 months of therapy, treatment was switched to zidovudine
plus lamivudine plus nelfinavir. CD4+ T cell count decreased from 559 x 10(6)/L
at month 0 to 259 x 10(6)/L at month 12. Plasma viral load decreased from 21,665
HIV-1 RNA copies/mL at baseline (month 0) to <20 copies/mL after 1 month of
therapy with stavudine plus didanosine, and remained below 20 copies/mL until
month 12, but always >5 copies/mL. Viral load in tonsilar tissue at month 12 was
125,000 copies/mg of tissue. After the change to triple-drug therapy, the plasma
viral load decreased to 5 copies/mL, the CD4+ T cell count increased to 705 x
10(6)/L, and the viral load in tonsilar tissue decreased to <40 copies/mg of
tissue at month 24. A low level of HIV-1 replication could explain the lack of
immunologic response in patients with apparent virological response.
PMID- 10671349
TI - Shiga toxin-producing Escherichia coli urinary tract infection associated with
hemolytic-uremic syndrome in an adult and possible adverse effect of ofloxacin
therapy.
PMID- 10671350
TI - Streptococcus intermedius: A cause of lobar pneumonia with meningitis and brain
abscesses.
PMID- 10671351
TI - Central nervous system pneumocystosis in AIDS: antemortem diagnosis and
successful treatment.
PMID- 10671352
TI - Francisella tularensis endocarditis.
PMID- 10671354
TI - Cost implications of reporting nonpathogenic protozoa.
PMID- 10671353
TI - Trovafloxacin-induced acute hepatitis.
PMID- 10671356
TI - Reply
PMID- 10671355
TI - Successful treatment of vancomycin-resistant Enterococcus faecium bacteremia with
linezolid after failure of treatment with synercid (quinupristin/dalfopristin).
PMID- 10671358
TI - Reply
PMID- 10671357
TI - Detection of Mycoplasma pneumoniae DNA in cerebrospinal fluid and local immune
response.
PMID- 10671359
TI - Screening for Chlamydia trachomatis infection in college women with a polymerase
chain reaction assay.
PMID- 10671360
TI - Factors associated with incomplete virological response to highly active
antiretroviral therapy.
PMID- 10671361
TI - Rash and opportunistic pneumonia in a malnourished infant adopted from China.
PMID- 10671362
TI - Does hepatitis C virus really have no effect on survival in cases of infection
with human immunodeficiency virus?
PMID- 10671363
TI - Adverse effects of minocycline versus doxycycline in the treatment of Lyme
neuroborreliosis.
PMID- 10671364
TI - Reply
PMID- 10671365
TI - Roles of caspases in apoptosis, development, and cytokine maturation revealed by
homozygous gene deficiencies.
AB - Caspases are a group of cysteine proteases critical for apoptosis of eukaryotic
cells. Deletion of genes that encode murine caspases suggests that caspases are
involved not only in apoptosis but also in cytokine maturation and cell growth
and differentiation. Among them, caspase-1 and caspase-11 are primarily involved
in the processing of pro-inflammatory cytokines. Caspase-3 and caspase-9 are
essential for apoptosis during brain development. Caspase-8 is required for the
development of heart muscle, cell proliferation in the hematopoietic lineage and
death-receptor-mediated apoptosis. These studies suggest that caspases function
in cell signaling events including apoptosis, cell growth and differentiation.
PMID- 10671366
TI - The actin cytoskeleton of Dictyostelium: a story told by mutants.
AB - Actin-binding proteins are effectors of cell signalling and coordinators of
cellular behaviour. Research on the Dictyostelium actin cytoskeleton has focused
both on the elucidation of the function of bona fide actin-binding proteins as
well as on proteins involved in signalling to the cytoskeleton. A major part of
this work is concerned with the analysis of Dictyostelium mutants. The results
derived from these investigations have added to our understanding of the role of
the actin cytoskeleton in growth and development. Furthermore, the studies have
identified several cellular and developmental stages that are particularly
sensitive to an unbalanced cytoskeleton. In addition, use of GFP fusion proteins
is revealing the spatial and temporal dynamics of interactions between actin
associated proteins and the cytoskeleton.
PMID- 10671367
TI - Epithelial stem cell-mediated development of the human respiratory mucosa in SCID
mice.
AB - We have developed an in vivo assay for progenitor cells of the human
tracheobronchial epithelium relying on the transplantation of human prenatal
respiratory tissues into severe combined immunodeficiency mice. Engrafted
embryonic or fetal open tracheobronchial rudiments are rapidly closed at each end
by a neoformed membrane that we named the operculum. After 2-4 weeks,
differentiated human respiratory epithelium covers both the native airway matrix
and the new operculum. Human epithelial cells dissociated from either emerging
embryonic lung primordia or mature xenografts were seeded in host human airway
grafts, of which native epithelium had been eliminated by several cycles of
freezing and thawing. All grafts seeded with donor epithelial cells and implanted
back into SCID mice recovered a surface mucociliary epithelium expressing
expected markers and secreting mucus. Spontaneous epithelium regrowth was never
observed in control unseeded, denuded grafts. In some experiments, donor
epithelial cells and host denuded airway were sex-mismatched and the donor origin
of newly formed epithelial structures was confirmed by sex chromosome detection.
After two rounds of seeding and reimplantation, a normal epithelium was observed
to line the 3rd generation operculum. These observations substantiate a
functional assay for human candidate airway epithelium stem cells.
PMID- 10671368
TI - Live fluorescence imaging reveals early recruitment of emerin, LBR, RanBP2, and
Nup153 to reforming functional nuclear envelopes.
AB - We determined the times when the nuclear membrane, nuclear pore complex (NPC)
components, and nuclear import function were recovered during telophase in living
HeLa cells. Simultaneous observation of fluorescently-labeled NLS-bearing
proteins, lamin B receptor (LBR)-GFP, and Hoechst33342-stained chromosomes
revealed that nuclear membranes reassembled around chromosomes by 5 minutes after
the onset of anaphase (early telophase) whereas nuclear import function was
recovered later, at 8 minutes. GFP-tagged emerin also accumulated on chromosomes
5 minutes after the onset of anaphase. Interestingly, emerin and LBR initially
accumulated at distinct, separate locations, but then became uniform 8 minutes
after the onset of anaphase, concurrent with the recovery of nuclear import
function. We further determined the timing of NPC assembly by immunofluorescence
staining of cells fixed at precise times after the onset of anaphase. Taken
together, these results showed that emerin, LBR, and several NPC components
(RanBP2, Nup153, p62), but not Tpr, reconstitute around chromosomes very early in
telophase prior to the recovery of nuclear import activity.
PMID- 10671369
TI - Fibronectin fragments induce MMP activity in mouse mammary epithelial cells:
evidence for a role in mammary tissue remodeling.
AB - Mammary gland form and function are regulated by interactions between epithelium
and extracellular matrix. Major glycoprotein components of extracellular matrix
have been identified that give survival, proliferation and differentiation
signals to mammary epithelial cells. We provide evidence that proteolytic
fragments of the extracellular matrix glycoprotein, fibronectin, suppress growth
and can promote apoptosis of mouse mammary epithelial cells. During mammary gland
involution, total fibronectin and fibronectin fragment levels are increased. The
peak levels of fibronectin protein and fragments are observed 4-6 days post
weaning, coincident with the peak in epithelial cell death. Using a model for
hormone withdrawal-induced death of mammary epithelium, elevated levels of
fibronectin proteolytic fragments were associated with apoptosis in TM-6 cells, a
tumorigenic mouse mammary epithelial cell line. Treatment of TM-6 cells with
exogenous fibronectin fragments (FN120) reduced cell number, and induced
apoptosis and matrix degrading protease activity. Inhibition of matrix protease
activity rescued TM-6 cell viability, indicating that FN120-induced cell loss is
mediated through matrix protease activity. In a three-dimensional model for
mammary gland development, FN120 reduced alveolar-like and promoted ductal-like
development by a matrix protease-dependent mechanism. These data suggest that
during post-lactational involution, fibronectin fragments may contribute to
epithelial cell loss and dissolution of mammary alveoli by inducing matrix
degrading proteinases.
PMID- 10671370
TI - Brain derived versican V2 is a potent inhibitor of axonal growth.
AB - In this paper, we identify the chondroitin sulfate proteoglycan versican V2 as a
major inhibitor of axonal growth in the extracellular matrix of the mature
central nervous system. In immunohistochemical and in situ hybridization
experiments we show that this tissue-specific splice variant of versican is
predominantly present in myelinated fiber tracts of the brain and in the optic
nerve, most likely being expressed by oligodendrocytes. We demonstrate that
isolated versican V2 strongly inhibits neurite outgrowth of central and
peripheral neurons in stripe-choice assays using laminin-1 as permissive
substrate. The inhibitory character of versican V2 is maintained after removal of
chondroitin sulfate and N- and O-linked oligosaccharide side chains, but it is
abolished after core protein digestion with proteinase-K. Our data support the
notion, that intact versican V2 prevents excessive axonal growth during late
phases of development and hereby participates in the structural stabilization of
the mature central nervous system.
PMID- 10671371
TI - Mitotic phosphorylation of SUV39H1, a novel component of active centromeres,
coincides with transient accumulation at mammalian centromeres.
AB - Centromeres of eukaryotes are frequently associated with constitutive
heterochromatin and their activity appears to be coregulated by epigenetic
modification of higher order chromatin. Recently, we isolated murine (Suv39h1)
and human (SUV39H1) homologues of the dominant Drosophila suppressor of position
effect variegation Su(var)3-9, which is also related to the S. pombe silencing
factor Clr4. We have shown that mammalian Su(var)3-9 homologues encode novel
centromeric proteins on metaphase-arrested chromosomes. Here, we describe a
detailed analysis of the chromatin distribution of human SUV39H1 during the cell
cycle. Although there is significant heterochromatic overlap between SUV39H1 and
M31 (HP1(beta)) during interphase, mitotic SUV39H1 displays a more restricted
spatial and temporal association pattern with metaphase chromosomes than M31
(HP1(beta)), or the related HP1(&agr;) gene product. SUV39H1 specifically
accumulates at the centromere during prometaphase but dissociates from
centromeric positions at the meta- to anaphase transition. In addition, SUV39H1
selectively associates with the active centromere of a dicentric chromosome and
also with a neocentromere. Interestingly, SUV39H1 is shown to be a phosphoprotein
with modifications at serine and, to a lesser degree, also at threonine residues.
Whereas SUV39H1 steady-state protein levels appear constant during the cell
cycle, two additional phosphorylated isoforms are detected in mitotic extracts.
This intriguing localisation and modification pattern would be consistent with a
regulatory role(s) for SUV39H1 in participating in higher order chromatin
organisation at mammalian centromeres.
PMID- 10671372
TI - Calcium regulation of microtubule sliding in reactivated sea urchin sperm
flagella.
AB - The changes in the bending pattern of flagella induced by an increased
intracellular Ca(2+) concentration are caused by changes in the pattern and
velocity of microtubule sliding. However, the mechanism by which Ca(2+) regulates
microtubule sliding in flagella has been unclear. To elucidate it, we studied the
effects of Ca(2+) on microtubule sliding in reactivated sea urchin sperm flagella
that were beating under imposed head vibration. We found that the maximum
microtubule sliding velocity obtainable by imposed vibration, which was about 170
180 rad/second in the presence of 250 microM MgATP and <10(-9) M Ca(2+), was
decreased by 10(-6)-10(-5) M Ca(2+) by about 15-20%. Similar decrease of the
sliding velocity was observed at 54 and 27 microM MgATP. The Ca(2+)-induced
decrease of the sliding velocity was due mainly to a decrease in the reverse bend
angle. When the plane of beat was artificially rotated by rotating the plane of
vibration of the pipette that held the sperm head, the asymmetric bending pattern
also rotated at 10(-5) M Ca(2+) as well as at <10(-9) M Ca(2+). The rotation of
the bending pattern was observed at MgATP higher than 54 microM ( approximately
100 microM ATP). These results indicate that the Ca(2+)-induced decrease of the
sliding velocity is mediated by a rotatable component or components (probably the
central pair) at high MgATP, but is not due to specific dynein arms on particular
doublets. We further investigated the effects of a mild trypsin treatment and of
trifluoperazine on the Ca(2+)-induced decrease in sliding velocity. Axonemes
treated for 3 minutes with a low concentration (0.1 microgram/ml) of trypsin beat
with a more symmetrical waveform than before the treatment. Also, their
microtubule sliding velocity and reverse bend angle were not affected by high
Ca(2+) concentrations. Trifluoperazine (25-50 microM) had no effect on the
decrease of the sliding velocity in beating flagella at 10(-5) M Ca(2+). However,
the flagella that had been 'quiescent' at 10(-4) M Ca(2+) resumed asymmetrical
beating following an application of 10-50 microM trifluoperazine. In such beating
flagella, both the sliding velocity and the reverse bend angle were close to
their respective values at 10(-5) M Ca(2+). Trypsin treatment induced a similar
recovery of beating in quiescent flagella at 10(-)(4) M Ca(2+), albeit with a
more symmetrical waveform. These results provide first evidence that, at least at
ATP concentrations higher than approximately 100 microM, 10(-6)-10(-5) M Ca(2+)
decreases the maximum sliding velocity of microtubules in beating flagella
through a trypsin-sensitive regulatory mechanism which possibly involves the
central pair apparatus. They also suggest that calmodulin may be associated with
the mechanism underlying flagellar quiescence induced by 10(-4) M Ca(2+).
PMID- 10671373
TI - The large intracytoplasmic loop of the glucose transporter GLUT2 is involved in
glucose signaling in hepatic cells.
AB - The hypothesis that the glucose transporter GLUT2 can function as a protein
mediating transcriptional glucose signaling was addressed. To divert the putative
interacting proteins from a glucose signaling pathway, two intracytoplasmic
domains of GLUT2, the C terminus and the large loop located between transmembrane
domains 6 and 7, were transfected into mhAT3F hepatoma cells. Glucose-induced
accumulation of two hepatic gene mRNAs (GLUT2 and L-pyruvate kinase) was
specifically inhibited in cells transfected with the GLUT2 loop and not with the
GLUT2 C terminus. The dual effects of glucose were dissociated in cells
expressing the GLUT2 loop; in fact a normal glucose metabolism into glycogen
occurred concomitantly with the inhibition of the glucose-induced transcription.
This inhibition by the GLUT2 loop could be due to competitive binding of a
protein that normally interacts with endogenous GLUT2. In addition, the GLUT2
loop, tagged with green fluorescent protein (GFP), was located within the
nucleus, whereas the GFP and GFP-GLUT2 C-terminal proteins remained in the
cytoplasm. In living cells, a fraction (50%) of the expressed GFP-GLUT2 loop
translocated rapidly from the cytoplasm to the nucleus in response to high
glucose concentration and conversely in the absence of glucose. We conclude that,
via protein interactions with its large loop, GLUT2 may transduce a glucose
signal from the plasma membrane to the nucleus.
PMID- 10671374
TI - Nidogen-1 regulates laminin-1-dependent mammary-specific gene expression.
AB - Nidogen-1 (entactin) acts as a bridge between the extracellular matrix molecules
laminin-1 and type IV collagen, and thus participates in the assembly of basement
membranes. To investigate the role of nidogen-1 in regulating cell-type-specific
gene expression in mammary epithelium, we designed a culture microecosystem in
which each component, including epithelial cells, mesenchymal cells, lactogenic
hormones and extracellular matrix, could be controlled. We found that primary and
established mesenchymal and myoepithelial cells synthesized and secreted nidogen
1, whereas expression was absent in primary and established epithelial cells. In
an epithelial cell line containing mesenchymal cells, nidogen-1 was produced by
the mesenchymal cells but deposited between the epithelial cells. In this mixed
culture, mammary epithelial cells express (beta)-casein in the presence of
lactogenic hormones. Addition of either laminin-1 plus nidogen-1, or laminin-1
alone, to mammary epithelial cells induced (beta)-casein production. We asked
whether recombinant nidogen-1 alone could signal directly for (beta)-casein.
Nidogen-1 did not induce (beta)-casein synthesis in epithelial cells, but it
augmented the inductive capacity of laminin-1. These data suggest that nidogen-1
can cooperate with laminin-1 to regulate (beta)-casein expression. Addition of
full-length nidogen-1 to the mixed cultures had no effect on (beta)-casein gene
expression; however, a nidogen-1 fragment containing the laminin-1 binding
domain, but lacking the type IV collagen-binding domain, had a dominant negative
effect on (beta)-casein expression. These data point to a physiological role for
nidogen-1 in the basement membrane-induced gene expression by epithelial cells.
PMID- 10671375
TI - Assembly of the exogenous extracellular matrix during basement membrane formation
by alveolar epithelial cells in vitro.
AB - We found that immortalized alveolar type II epithelial cells (SV40-T2 cells) that
were cultured on dense fibrillar collagen supplemented with Matrigel gel formed a
thin and continuous lamina densa beneath them. Immunohistochemical analysis of
laminin-1, type IV collagen, entactin (nidogen) and perlecan in the culture
indicated that all these components were integrated into a sheet structure of
basement membrane beneath the cells. Analysis of the temporal and spatial
distribution of the basement membrane macromolecules revealed that the initial
deposits of laminin-1 and entactin were significantly greater in area in the
presence of Matrigel. These globular deposits and the coarse mesh of basement
membrane macromolecules developed into a flat membranous basement membrane. In
the absence of Matrigel, the SV40-T2 cells failed to form a continuous lamina
densa, and the deposits stayed in the coarse mesh. The major biotinylated
Matrigel components that were integrated into the basement membrane were laminin
1 and entactin. Furthermore, SV40-T2 cells supplemented with exogenous laminin-1
alone as well as laminin-1 contaminated with entactin formed a continuous lamina
densa. These results indicate that the laminin-1 and entactin supplied from the
Matrigel were incorporated into a basement membrane beneath the SV40-T2 cells,
and contributed to the formation of basement membrane. Therefore, we concluded
that the alveolar epithelial cells synthesize laminin-1, entactin, type IV
collagen, and perlecan, but that they also needed to assemble exogenous laminin-1
into the basement membrane to complete its formation in vitro.
PMID- 10671376
TI - Integrin binding specificity of laminin-10/11: laminin-10/11 are recognized by
alpha 3 beta 1, alpha 6 beta 1 and alpha 6 beta 4 integrins.
AB - Laminin-10/11, the laminin isoforms containing the alpha 5 chain, are major
components of basement membranes of many fetal and adult tissues. Laminin-10/11
purified from the conditioned medium of human lung carcinoma cells were potent in
mediating adhesion of the carcinoma cells in an integrin alpha 3 beta 1-dependent
manner. To further define the type(s) of integrins involved in cell adhesion to
laminin-10/11, we examined the effects of a panel of function-blocking anti
integrin antibodies on the adhesion of different cell types to laminin-10/11.
Although anti-integrin beta 1 antibody inhibited the adhesion of all cell types
tested, anti-alpha 3 antibody inhibited the adhesion of carcinoma and glioma
cells but not fibroblastic cells. Adhesion of fibroblastic cells was inhibited,
however, by a combination of anti-alpha 3 and anti-alpha 6 antibodies, suggesting
that both alpha 3 beta 1 and alpha 6 beta 1 integrins function as laminin-10/11
receptors in these cells. To explore this possibility, we examined the adhesion
of K562 leukemic cells transfected with integrin alpha 3 or alpha 6 subunit to
laminin-10/11 or other laminin isoforms. Laminin-10/11 were potent adhesive
ligands for both the alpha 3 beta 11 and alpha 6 beta 1 transfectants, whereas
laminin-5 was the preferred ligand for the alpha 3 beta 1 transfectants. Upon
stimulation with the activating anti-integrin beta 1 antibody, both transfectants
became more adherent to the substratum regardless of the type of laminins coated,
although their preference for laminin isoforms remained unaltered. K562 cells
transfected with alpha 6 and beta 4 subunits were also capable of adhering to
laminin-10/11, indicating that integrin alpha 6 beta 4 is another receptor for
laminin-10/11. Even with lung carcinoma cells, the alpha 6-containing integrins
partly contributed to adhesion to laminin-10/11 at higher coating concentrations,
although non-integrin receptor(s) might also be involved under such conditions.
These results indicated that laminin-10/11 are potent and versatile adhesive
ligands in basement membranes capable of binding to both alpha 3 beta 1 and alpha
6 beta 1 integrins with high avidity and also to alpha 6 beta 4 integrin.
PMID- 10671377
TI - ARP1 in Golgi organisation and attachment of manchette microtubules to the
nucleus during mammalian spermatogenesis.
AB - Actin related protein of vertebrate, Arp1, is a major component of the dynactin
complex. To characterise and localise Arp1 during mammalian spermatogenesis,
polyclonal antibodies were raised against a human recombinant Arp1. Anti-Arp1
antibodies were used for western-immunoblotting, indirect immunofluorescence and
immunoelectron microscopy. In round spermatids, Arp1 was detected at the
centrosome and at the Golgi apparatus. In elongated spermatids, Arp1 was
predominantly found along microtubules of the manchette and at their site of
attachment to the nuclear envelope. In maturing spermatids, Arp1 was still
present in the pericentriolar material, but in testicular spermatozoa it was not
detectable. These various localisations of Arp1 and their changes during
spermatid differentiation suggest that the dynactin complex in association with
dynein might contribute to several activities: the functional organisation of the
centrosome and of the Golgi apparatus and the shaping of the nucleus by manchette
microtubules.
PMID- 10671378
TI - Selective activation of pre-replication complexes in vitro at specific sites in
mammalian nuclei.
AB - As the first step in determining whether or not pre-replication complexes are
assembled at specific sites along mammalian chromosomes, nuclei from G(1)-phase
hamster cells were incubated briefly in Xenopus egg extract in order to initiate
DNA replication. Most of the nascent DNA consisted of RNA-primed DNA chains 0.5
to 2 kb in length, and its origins in the DHFR gene region were mapped using both
the early labeled fragment assay and the nascent strand abundance assay. The
results revealed three important features of mammalian replication origins.
First, Xenopus egg extract can selectively activate the same origins of bi
directional replication (e.g. ori-beta) and (beta') that are used by hamster
cells in vivo. Previous reports of a broad peak of nascent DNA centered at ori
(beta/(beta)' appeared to result from the use of aphidicolin to synchronize
nuclei and from prolonged exposure of nuclei to egg extracts. Second, these sites
were not present until late G(1)-phase of the cell division cycle, and their
appearance did not depend on the presence of Xenopus Orc proteins. Therefore,
hamster pre-replication complexes appear to be assembled at specific chromosomal
sites during G(1)-phase. Third, selective activation of ori-(beta) in late G(1)
nuclei depended on the ratio of Xenopus egg extract to nuclei, revealing that
epigenetic parameters such as the ratio of initiation factors to DNA substrate
could determine the number of origins activated.
PMID- 10671379
TI - Import of proteins into the trypanosome nucleus and their distribution at
karyokinesis.
AB - In all eukaryotic organisms proteins are targeted to the nucleus via a receptor
mediated mechanism that requires a specific nuclear localization sequence (NLS)
in the protein. Little is known about this process in trypanosomatid protozoa
that are considered amongst the earliest divergent eukaryotes. We have used the
green fluorescent protein (gfp) and beta-galactosidase reporters to identify the
NLS of two trypanosomal proteins, namely the Trypanosoma brucei La protein
homologue and histone H2B of T. cruzi. A monopartite NLS was demonstrated at the
C terminus of the La protein, whereas a bipartite NLS was identified within the
first 40 amino acids of histone H2B. Treatment of live trypanosomes with poisons
of ATP synthesis resulted in exit of the La NLS-gfp fusion from the nucleus.
Interestingly, this fusion protein accumulated at several discrete sites in the
cytoplasm, rather than equilibrating between the nucleus and the cytoplasm. When
ATP levels returned to normal, the protein reentered the nucleus, demonstrating
that the process was energy dependent. Finally, using fusion proteins that
localize to the nucleoplasm or the nucleolus, we identified a subpopulation of
mitotic cells in which the chromosomes have segregated but the daughter nuclei
remain connected by a thin thread-like structure. We propose that cells
containing this structure represent a late stage in nuclear division that can be
placed after chromosome segregation, but before completion of karyokinesis.
PMID- 10671381
TI - Images in neuroscience. Cognition: procedural memory.
PMID- 10671382
TI - How can we learn about developmental processes from cross-sectional studies, or
can we?
AB - OBJECTIVE: Cross-sectional studies are often used in psychiatric research as a
basis of longitudinal inferences about developmental or disease processes. While
the limitations of such usage are often acknowledged, these are often
understated. The authors describe how such inferences are often, and sometimes
seriously, misleading. METHOD: Why and how these inferences mislead are here
demonstrated on an intuitive level, by using simulated data inspired by real
problems in psychiatric research. RESULTS: Four factors with major roles in the
relationship between cross-sectional studies and longitudinal inferences are
selection of time scale, type of developmental process studied, reliability of
measurement, and clarity of terminology. The authors suggest how to recognize
inferential errors when they occur, describe how to protect against such errors
in future research, and delineate the circumstances in which only longitudinal
studies can answer crucial questions. CONCLUSIONS: The simple conclusion is that
one must always use the results of cross-sectional studies to draw inferences
about longitudinal processes with trepidation.
PMID- 10671383
TI - Late-onset schizophrenia and very-late-onset schizophrenia-like psychosis: an
international consensus. The International Late-Onset Schizophrenia Group.
AB - OBJECTIVE: Although schizophrenia is generally regarded as an illness with onset
in late adolescence or early adult life, a sizeable minority of patients first
become ill in middle or old age. Inconsistencies in diagnostic systems and
nomenclature, coupled with a tendency among most schizophrenia researchers to
ascribe late-onset psychoses to organic factors, have led to such cases occupying
an ambiguous position in relation to schizophrenia. Through systematic review of
the literature and publication of a consensus statement from an international
group of experts in the field, this article aims to clarify the positions of late
onset schizophrenia and very-late-onset schizophrenia-like psychosis. METHOD: The
authors conducted a MEDLINE literature review and developed a consensus statement
summarizing the findings from 2 days of debate and discussion by members of the
International Late-Onset Schizophrenia Group. RESULTS: The group achieved
consensus on diagnosis, nomenclature, treatment guidelines, and future research
directions. CONCLUSIONS: In terms of epidemiology, symptom profile, and
identified pathophysiologies, the diagnoses of late-onset schizophrenia (illness
onset after 40 years of age) and very-late-onset schizophrenia-like psychosis
(onset after 60 years) have face validity and clinical utility. General adoption
of these categories will foster systematic investigation of such patients.
PMID- 10671384
TI - Risk of recurrence of bipolar disorder in pregnant and nonpregnant women after
discontinuing lithium maintenance.
AB - OBJECTIVE: Pregnancy poses major challenges for the treatment of bipolar
disorder, and information to guide clinical care remains very sparse. The authors
sought to determine the illness recurrence risk for women with bipolar disorder
who discontinue lithium maintenance during pregnancy. METHOD: The authors
retrospectively compared recurrence rates and survival functions for 101 women
with DSM-IV bipolar disorder (68 type I, 33 type II) during pregnancy and
postpartum (N=42) or during equivalent periods (weeks 1-40 and 41-64) for age
matched nonpregnant subjects (N=59) after either rapid (1-14 days) or gradual (15
30 days) discontinuation of lithium. Recurrence rates also were obtained for the
year before discontinuing lithium. RESULTS: Rates of recurrence during the first
40 weeks after lithium discontinuation were similar for pregnant (52%) and
nonpregnant women (58%) but had been much lower for both in the year before
treatment was discontinued (21%). Among subjects who remained stable over the
first 40 weeks after lithium discontinuation, postpartum recurrences were 2.9
times more frequent than recurrences in nonpregnant women during weeks 41-64 (70%
versus 24%). Depressive or dysphoric-mixed episodes were more prevalent in
pregnant than nonpregnant women (63% versus 38% of recurrences). Recurrence risk
was greater after rapid than after gradual discontinuation, and for patients with
more prior affective episodes, but was similar for diagnostic types I and II.
CONCLUSIONS: Rates of recurrence during the first 40 weeks after lithium
discontinuation were similar for pregnant and nonpregnant women but then sharply
increased postpartum. Risk was much lower during preceding treatment and less
with gradual discontinuation. Treatment planning for potentially pregnant women
with bipolar disorder should consider the relative risks of fetal exposure to
mood stabilizers versus the high recurrence risks after discontinuing lithium.
PMID- 10671385
TI - Paroxetine in human breast milk and nursing infants.
AB - OBJECTIVE: The purpose of this study was to determine the extent of infant
medication exposure through breast-feeding during maternal treatment with
paroxetine. METHOD: Breast milk and paired maternal and infant sera were
collected after 10 days of maternal treatment with paroxetine at a stable daily
dose (10-50 mg/day). All samples were analyzed by means of high-performance
liquid chromatography with ultraviolet detection and a limit of detection of 2
ng/ml. RESULTS: Breast milk paroxetine concentrations were highly variable (2-101
ng/ml) and were present in all breast milk samples (N=108). A significant
gradient effect was observed, with greater paroxetine concentrations found in
later portions of breast milk (hind milk) than in early portions (fore milk). No
clear time course of paroxetine excretion into breast milk was demonstrated,
although maternal paroxetine daily dose reliably predicted both trough and peak
breast milk concentrations over a 24-hour period. In 16 mother and infant serum
pairs, no detectable concentrations of paroxetine were found in the serum of the
nursing infants. CONCLUSIONS: This study extends previous data by demonstrating
the presence of paroxetine in the breast milk of nursing women treated with this
medication. The low concentrations of paroxetine in infant serum and lack of any
observable adverse effects after maternal use of this medication while breast
feeding parallels the available data on other selective serotonin reuptake
inhibitors.
PMID- 10671386
TI - Further evidence of relation between prenatal famine and major affective
disorder.
AB - OBJECTIVE: In a previous study, the authors demonstrated an association between
prenatal famine in middle to late gestation and major affective disorders
requiring hospitalization. In this study, they sought to examine the association
by using newly identified cases from the Dutch birth cohort used previously to
examine the gender specificity of the association and to assess whether this
relation is present for both unipolar and bipolar affective disorders. METHOD:
The authors compared the risk of major affective disorder requiring
hospitalization in birth cohorts who were and were not exposed, in each trimester
of gestation, to famine during the Dutch Hunger Winter of 1944-1945. These cases
of major affective disorder requiring hospitalization were newly ascertained from
a national psychiatric registry. A larger data set from this registry was used
for analysis by gender and diagnostic subtype. RESULTS: For the newly ascertained
cases, the risk of developing major affective disorder requiring hospitalization
was increased for subjects with exposure to famine in the second trimester and
was increased significantly for subjects with exposure in the third trimester,
relative to unexposed subjects. For the cases from the entire period of
ascertainment, the risk of developing affective disorder was significantly
increased for those exposed to famine during the second and the third trimesters
of gestation. The effects were demonstrated for men and women and for unipolar
and bipolar affective disorders. CONCLUSIONS: These results provide support for
the authors' previous findings on the association between middle to late
gestational famine and affective disorder.
PMID- 10671387
TI - Hypoxic-ischemia-related fetal/neonatal complications and risk of schizophrenia
and other nonaffective psychoses: a 19-year longitudinal study.
AB - OBJECTIVE: Epidemiologic evidence linking obstetric complications to
schizophrenia has been positive but inconclusive. One reason for the lack of
conclusive evidence may be the inconsistency in measuring disturbances of
fetal/neonatal brain development based on general obstetric markers of maternal
health. The authors used data from the National Collaborative Perinatal Project
to examine the relationship between schizophrenia and other nonaffective
psychoses and a theoretically derived measure of hypoxic-ischemia-related
fetal/neonatal complications. METHOD: Six hundred ninety-three men and women
(average age 23) born to a community sample of women between 1959 and 1966 were
followed up an average of 19 years after early childhood assessments. Subjects
with DSM-IV schizophrenia and other nonaffective psychoses were identified using
the Diagnostic Interview Schedule and best-estimate consensus diagnoses. RESULTS:
Hypoxic-ischemia-related fetal/neonatal complications were associated with a
doubling of the risk of developing a psychotic disorder, compared with no
relevant complications (6.9% versus 1.4%). When mood disorders were excluded from
the group of psychotic diagnoses, the risk of schizophrenia and other
nonaffective psychoses associated with hypoxic-ischemia-related fetal/neonatal
complications was strikingly elevated, compared with no relevant complications
(5.75% versus 0.39%). Nonpsychotic mood disorders were unrelated to these
fetal/neonatal complications. Schizophrenia and other nonaffective psychoses were
most strongly associated with hypoxic-ischemia-related fetal/neonatal
complications of disordered growth and development. CONCLUSIONS: The data show a
strikingly elevated, graded, independent risk of schizophrenia and other
nonaffective psychoses associated with this classification of antecedent hypoxic
ischemia-related fetal/neonatal complications.
PMID- 10671388
TI - Relationship of obstetric complications and differences in size of brain
structures in monozygotic twin pairs discordant for schizophrenia.
AB - OBJECTIVE: The aim of the study was to determine whether a history of obstetric
complications and congenital minor physical anomalies are related to differences
in the characteristics of brain structures observed within monozygotic twin pairs
discordant for schizophrenia. METHOD: The size of the bilateral hippocampi and
cerebral ventricles was studied by magnetic resonance imaging in 22 monozygotic
twin pairs discordant for schizophrenia. Obstetric complications and minor
physical anomalies were independently assessed through parental report and
examination, respectively. RESULTS: Compared with the well co-twins, the ill
twins consistently had smaller left and right hippocampi as well as larger left
lateral ventricles and third ventricles. Relatively small left and right
hippocampi were each significantly related to labor-delivery complications and to
prolonged labor per se. Relatively large right lateral ventricle size and large
total ventricle size were significantly related to labor-delivery complications,
prolonged labor, neonatal complications, and total complications for the entire
reproductive sequence. In contrast, these brain size differences were not
significantly associated with pregnancy complications or minor physical
anomalies. CONCLUSIONS: Trauma at the time of labor and delivery and especially
prolonged labor appear to be of importance for brain structure anomalies
associated with schizophrenia.
PMID- 10671389
TI - Phenomenology and outcome of subjects with early- and adult-onset psychotic
mania.
AB - OBJECTIVE: This study examined clinical differences between subjects with early
onset and adult-onset psychotic mania. METHOD: Subjects were from an
epidemiologically derived, hospitalized sample who met criteria for definite
bipolar disorder after 24 months of follow-up and whose index episode had been
manic. Information collected regarding demographic characteristics, psychotic and
depressive symptoms, childhood behavior problems and school functioning,
substance/alcohol use disorders, and episode recurrence for two subgroups were
compared: those whose illness first emerged before age 21 (early onset) (N=23)
and those whose first episode occurred after age 30 (adult onset) (N=30).
RESULTS: A larger proportion of the early-onset subjects were male, had childhood
behavior disorders, had substance abuse comorbidity, exhibited paranoia, and
experienced complete episode remission less frequently during 24-month follow-up
than the adult-onset subjects. CONCLUSIONS: These data add to the body of
evidence that has suggested that many subjects with early-onset psychotic mania
have a more severe and developmentally complicated subtype of bipolar disorder.
PMID- 10671390
TI - Two-year syndromal and functional recovery in 219 cases of first-episode major
affective disorder with psychotic features.
AB - OBJECTIVE: Psychotic affective disorders are the most prevalent idiopathic
psychoses, but their outcome from onset has rarely been studied. In this study,
the authors determined the rate and latency of syndromal recovery and rates of
functional recovery after first lifetime hospitalization in patients with first
episode psychotic affective disorders. METHOD: From first lifetime
hospitalization in 1989-1996, 219 patients with a DSM-IV psychotic affective
illness were assessed at intervals over 24 months. Time to syndromal recovery (no
longer meeting DSM-IV episode criteria) was assessed by survival analysis, and
functional recovery (regaining baseline vocational and residential status) was
rated. Factors associated with recovery were identified by bivariate and
multivariate methods. RESULTS: By 3, 6, 12, and 24 months after first
hospitalization, syndromal recovery was attained by 65.1%, 83.7%, 91.1%, and
97.5%, respectively, of subjects. Time to syndromal recovery (6.1 weeks to 50% of
subjects recovered) was shorter for patients who had bipolar disorder, were
married, were age 30 or older at onset, lacked comorbidity, required relatively
brief hospitalization, and received fewer medicines. Functional recovery by 6
(30.4%) and 24 months (37. 6% of patients) was 2.6-2.7 times less likely than
syndromal recovery; 63.1% of those recovering syndromally did not recover
functionally by 2 years. Functional recovery was associated with older age at
onset and shorter hospitalization. Annual recovery rates remained stable as mean
hospital length of stay decreased 3. 6-fold over the 8-year study period.
CONCLUSIONS: Syndromal recovery was attained by most psychotic affective disorder
patients soon after hospitalization, but only one-third recovered functionally by
24 months. The findings suggest that these very common psychotic illnesses can
carry a grave functional prognosis from the initial episode and first
hospitalization.
PMID- 10671391
TI - Multiple recurrences of major depressive disorder.
AB - OBJECTIVE: The authors of this study examined multiple recurrences of unipolar
major depressive disorder. METHOD: A total of 318 subjects with unipolar major
depressive disorder were prospectively followed for 10 years within a multicenter
naturalistic study. Survival analytic techniques were used to examine the
probability of recurrence after recovery from the index episode. RESULTS: The
mean number of episodes of major depression per year of follow-up was 0. 21, and
nearly two-thirds of the subjects suffered at least one recurrence. The number of
lifetime episodes of major depression was significantly associated with the
probability of recurrence, such that the risk of recurrence increased by 16% with
each successive recurrence. The risk of recurrence progressively decreased as the
duration of recovery increased. Within subjects, there was very little
consistency in the time to recurrence. CONCLUSIONS: Major depressive disorder is
a highly recurrent illness. The risk of the recurrence of major depressive
disorder progressively increases with each successive episode and decreases as
the duration of recovery increases.
PMID- 10671392
TI - Lack of seasonal mood change in the Icelandic population: results of a cross
sectional study.
AB - OBJECTIVE: The prevalence of seasonal affective disorder-as measured by the
Seasonal Pattern Assessment Questionnaire-has been found to be unexpectedly low
among Icelanders. The aim of this cross-sectional study was to measure seasonal
variations in the prevalence of anxiety and depression among Icelanders assessed
with the Hospital Anxiety and Depression Questionnaire. METHOD: Four 1, 000
person cohorts, age 20-70 years, selected at random from the Icelandic National
Register, were sent the Hospital Anxiety and Depression Scale by mail in either
January, April, July, or October. Only responses from the 4-week period after
each mailing were considered in the subsequent analysis. RESULTS: The mean
anxiety and depression scores in winter were not higher than those in summer for
either sex. There was no significant difference between winter and summer in
rates of actual or borderline cases of anxiety or depression or for the two
categories combined. CONCLUSIONS: This lack of seasonality in anxiety and
depression is in sharp contrast to findings from similar cross-sectional studies
and may reflect the low propensity for seasonal affective disorder that has been
described in the Icelandic population.
PMID- 10671393
TI - Female sexual dysfunction associated with antidepressant administration: a
randomized, placebo-controlled study of pharmacologic intervention.
AB - OBJECTIVE: Few controlled trials of pharmacologic intervention in women with
antidepressant-associated sexual dysfunction have been reported, and there is
uncertainty about the usefulness of putative treatments and the assessment
methodologies. The authors evaluated the efficacy of buspirone and amantadine in
the treatment of sexual dysfunction associated with fluoxetine administration.
METHOD: Women who had been successfully treated with fluoxetine for at least 8
weeks and who had reported a deterioration in sexual function not present before
the initiation of fluoxetine entered a 4-week assessment period. After assessment
they were randomly assigned to an 8-week treatment trial with buspirone (N=19),
amantadine (N=18), or placebo (N=20). Outcomes were assessed by using a patient
rated daily diary and a clinician-rated structured interview. RESULTS: While the
amantadine-treated women did report significantly greater improvements in energy
levels than women in the placebo group, all treatment groups experienced
improvement in overall sexual function as well as in most individual measures.
There were no statistically significant differences among the three groups.
CONCLUSIONS: Neither buspirone nor amantadine was more effective than placebo in
ameliorating antidepressant-associated sexual dysfunction. All groups experienced
marked nonspecific improvement during treatment, which suggests the importance of
placebo-controlled trials for this condition.
PMID- 10671394
TI - Victims of criminal homicide in Sweden: a matched case-control study of health
and social risk factors among all 1,739 cases during 1978-1994.
AB - OBJECTIVE: The psychiatric and medical characteristics of victims of homicide
have not been systematically studied and are often confounded by race. This study
was undertaken to determine health and social factors contributing to the risk of
being murdered in the Swedish, predominantly Caucasian population. METHOD: All
1,739 homicides between 1978 and 1994 in Sweden were studied in terms of
variables in national case registers regarding health, crimes, immigration, and
marital status. The same data were extracted for matched comparison persons in
the general population, with controls for time of exposure. The data were
analyzed by conditional logistic regression on matched pairs. RESULTS: Traumatic
brain injury, physical abuse, alcohol dependence, and criminal recidivism
conferred risk of being murdered. CONCLUSIONS: To the authors' knowledge, this is
the first report of traumatic brain injury, in both men and women, as a risk
factor for being murdered. Brain injury may mark risk-taking behavior in general
or may cause provocative behavior.
PMID- 10671395
TI - Impact of psychiatric conditions on health-related quality of life in persons
with HIV infection.
AB - OBJECTIVE: Little is known about the impact of comorbid psychiatric symptoms in
persons with HIV. This study estimates the burden on health-related quality of
life associated with comorbid psychiatric conditions in a nationally
representative sample of persons with HIV. METHOD: The authors conducted a
multistage sampling of urban and rural areas to produce a national probability
sample of persons with HIV receiving medical care in the contiguous United States
(N=2,864). Subjects were screened for psychiatric conditions with the short form
of the Composite International Diagnostic Interview. Heavy drinking was assessed
on the basis of quantity and frequency of drinking. Health-related quality of
life was rated with a 28-item instrument adapted from similar measures used in
the Medical Outcomes Study. RESULTS: HIV subjects with a probable mood disorder
diagnosis had significantly lower scores on health-related quality of life
measures than did those without such symptoms. Diminished health-related quality
of life was not associated with heavy drinking, and in drug users it was
accounted for by presence of a comorbid mood disorder. CONCLUSIONS: Optimization
of health-related quality of life is particularly important now that HIV is a
chronic disease with the prospect of long-term survival. Comorbid psychiatric
conditions may serve as markers for impaired functioning and well-being in
persons with HIV. Inclusion of sufficient numbers of appropriately trained mental
health professionals to identify and treat such conditions may reduce unnecessary
utilization of other health services and improve health-related quality of life
in persons with HIV infection.
PMID- 10671396
TI - Auditory startle response in trauma survivors with posttraumatic stress disorder:
a prospective study.
AB - OBJECTIVE: Previous studies have shown elevated autonomic responses to startling
tones in trauma survivors with chronic posttraumatic stress disorder (PTSD). The
origin of these abnormal responses is obscure. The present study attempted to
clarify this issue by prospectively evaluating responses to sudden, loud tones in
individuals who arrived at a hospital emergency room after psychologically
traumatic events. METHOD: By using a previously established protocol, autonomic
and muscular responses to the tones were evaluated at 1 week, 1 month, and 4
months after the traumatic event. Structured diagnostic interviews performed at 4
months classified subjects into groups with (N=36) and without (N=182) PTSD,
which were further subdivided according to the presence or absence of major
depressive disorder as follows: neither PTSD nor depression (N=166), depression
alone (N=16), PTSD alone (N=21), and both PTSD and depression (N=15). RESULTS:
The groups showed comparable physiological responses to the tones at 1 week
posttrauma. However, at 1 and 4 months posttrauma, the subjects with PTSD showed
a greater heart rate response and required more stimulus trials to reach the
criteria of skin conductance and orbicularis oculi electromyogram nonresponse.
These findings were not significantly influenced by comorbid depression and were
not explained by the severity of the traumatic event or by the intensity of the
initial symptoms. CONCLUSIONS: Differences in physiological response to startling
tones develop along with PTSD in the months that follow a traumatic event. This
pattern supports the theories that associate PTSD with progressive neuronal
sensitization.
PMID- 10671397
TI - Asperger's disorder.
PMID- 10671398
TI - Images in psychiatry. Crichton royal hospital.
PMID- 10671399
TI - Striatal dopamine transporter binding in neuroleptic-naive patients with
schizophrenia studied with positron emission tomography.
AB - OBJECTIVE: Recent in vivo imaging studies indicate a dysregulated presynaptic
function of the striatal dopaminergic system in patients with schizophrenia. To
further explore the basis of this phenomenon, the authors studied brain dopamine
transporter binding in vivo in patients with first-episode, never-medicated
schizophrenia. METHOD: Nine patients with schizophrenia and nine healthy matched
comparison subjects were recruited. Striatal dopamine transporter binding was
measured with positron emission tomography and a specific dopamine transporter
ligand, [(18)F]CFT, a radiolabeled form of 2beta-carbomethoxy-3beta-(4
fluorophenyl)tropane. RESULTS: Average caudate and putamen dopamine transporter
binding potentials were almost identical in the patients and comparison subjects,
but the patients lacked the right-left asymmetry of the caudate dopamine
transporter binding seen in the comparison group. CONCLUSIONS: Average striatal
dopamine transporter density is unaltered in neuroleptic-naive patients with
schizophrenia. However, patients lack asymmetry in caudate dopamine transporter
binding, which conforms with disrupted brain lateralization in this disorder.
PMID- 10671400
TI - Genetic influence on laterality in schizophrenia? A twin study of neurological
soft signs.
AB - OBJECTIVE: This study explored the genetic basis of neurological soft signs in
schizophrenia and addressed disturbed hemispheric lateralization. METHOD: The
authors investigated neurological soft signs in 30 monozygotic twin pairs, 13
pairs discordant for schizophrenia or schizoaffective disorder and 17 healthy
comparison twin pairs. RESULTS: The twins with schizophrenia showed higher total
scores for neurological soft signs than did the comparison subjects. The total
scores for neurological soft signs of the nonaffected discordant twins were
significantly higher than those of the comparison twins. There was a significant
difference between the nonaffected and affected discordant twins in total scores
for neurological soft signs. In contrast to the comparison subjects, the
nonaffected and affected twins of the discordant pairs showed a trend toward
higher scores for neurological soft signs on the left body half. CONCLUSIONS:
These results suggest that the occurrence of neurological soft signs and, more
specifically, their lateralization to the left body half are genetically
transmitted.
PMID- 10671401
TI - Verbal working memory impairment in schizophrenia patients and their first-degree
relatives: evidence from the digit span task.
AB - OBJECTIVE: The evidence for verbal working memory deficits in schizophrenia has
been inconsistent. Few studies have evaluated verbal working memory in the first
degree relatives of schizophrenia patients, who likely share the genetic
diathesis for schizophrenia but not the potential confounds associated with
chronic mental illness. METHOD: The Wechsler Digit Span Task was used to
investigate verbal working memory in 52 schizophrenia patients, 56 of their first
degree relatives, and 73 nonpsychiatric comparison subjects. RESULTS: The
nonpsychotic relatives showed no impairment on the forward digit span task, a
measure of general attention, but did show impairment on the backward digit span
task, a measure of verbal working memory. Schizophrenia patients showed
impairment on both the forward and backward digit span tasks. CONCLUSIONS: These
results indicate that the forward and backward digit span tasks tap different
cognitive abilities that are differentially associated with the diathesis for
schizophrenia. Working memory deficits associated with schizophrenia appear to be
generalized and not limited to the spatial modality.
PMID- 10671402
TI - Alterations in the functional anatomy of working memory in adult attention
deficit hyperactivity disorder.
AB - OBJECTIVE: The authors used a functional neuroimaging study with a working memory
probe to investigate the pathophysiology of attention deficit hyperactivity
disorder (ADHD). Their goal was to compare regional cerebral blood flow (rCBF)
changes related to working memory in adults with and without ADHD. METHOD: Using
[(15)O]H(2)O positron emission tomography (PET) studies, the authors compared the
sites of neural activation related to working memory in six adult men diagnosed
with ADHD and six healthy men without ADHD who were matched in age and general
intelligence. RESULTS: Task-related changes in rCBF in the men without ADHD were
more prominent in the frontal and temporal regions, but rCBF changes in men with
ADHD were more widespread and primarily located in the occipital regions.
CONCLUSIONS: These data suggest the use of compensatory mental and neural
strategies by subjects with ADHD in response to a disrupted ability to inhibit
attention to nonrelevant stimuli and the use of internalized speech to guide
behavior.
PMID- 10671403
TI - MRI assessment of children with obsessive-compulsive disorder or tics associated
with streptococcal infection.
AB - OBJECTIVE: The authors assessed selective basal ganglia involvement in a subgroup
of children with obsessive-compulsive disorder (OCD) and/or tics believed to be
associated with streptococcal infection. METHOD: Using computer-assisted
morphometric techniques, they analyzed the cerebral magnetic resonance images of
34 children with presumed streptococcus-associated OCD and/or tics and 82 healthy
comparison children who were matched for age and sex. RESULTS: The average sizes
of the caudate, putamen, and globus pallidus, but not of the thalamus or total
cerebrum, were significantly greater in the group of children with streptococcus
associated OCD and/or tics than in the healthy children. The differences were
similar to those found previously for subjects with Sydenham's chorea compared
with normal subjects. CONCLUSIONS: These results support the hypothesis that
there is a distinct subgroup of subjects with OCD and/or tics who have enlarged
basal ganglia. These findings are consistent with the hypothesis of an autoimmune
response to streptococcal infection.
PMID- 10671404
TI - Altered cAMP-dependent protein kinase A in platelets of patients with obsessive
compulsive disorder.
AB - OBJECTIVE: The purpose of this study was to assess cAMP-dependent protein kinase
A in patients with obsessive-compulsive disorder (OCD). METHOD: The levels and
the activity of protein kinase A were evaluated in whole platelets obtained from
12 unmedicated patients with OCD and 15 healthy comparison subjects. RESULTS: The
immunolabeling of protein kinase A regulatory subunits type I and II were
significantly greater but that of the catalytic subunit significantly lower in
patients with OCD than in healthy subjects. The cAMP-stimulated activity in
patients with OCD was significantly lower than that in healthy subjects.
CONCLUSIONS: These data suggest a possible role of protein kinase A in the
pathophysiology of OCD.
PMID- 10671405
TI - Use of the selective serotonin 3 receptor antagonist ondansetron in the treatment
of neuroleptic-induced tardive dyskinesia.
AB - OBJECTIVE: The authors examined the efficacy, tolerability, and safety of
ondansetron, a selective serotonin 3 receptor antagonist, in patients with
tardive dyskinesia. METHOD: Twenty patients with schizophrenia who had
neuroleptic-induced tardive dyskinesia were given 12 mg/day of ondansetron for 12
weeks in an open-label study. RESULTS: Administration of ondansetron resulted in
a statistically significant improvement in tardive dyskinesia and psychotic
symptoms. CONCLUSIONS: Ondansetron may be an effective and safe therapy to
control tardive dyskinesia and psychosis in patients with schizophrenia.
PMID- 10671406
TI - Prediction of detached personality in healthy subjects by low dopamine
transporter binding.
AB - OBJECTIVE: Low striatal dopamine D(2) receptor binding in healthy human subjects
has been associated with detached personality in studies using positron emission
tomography (PET) and the Karolinska Scales of Personality questionnaire. The
authors investigated whether a similar correlation exists between striatal
dopamine transporter binding and detached personality. METHOD: Eighteen healthy
volunteers participated in a PET study with the specific dopamine transporter
ligand [(18)F]CFT ([(18)F]WIN 35,428) and completed the Karolinska Scales of
Personality questionnaire form. RESULTS: Age-corrected dopamine transporter
binding in the putamen, but not in the caudate, correlated negatively with
detachment personality scores, especially in the right hemisphere. CONCLUSIONS:
This finding supports the hypothesis that low dopaminergic neurotransmission is
associated with detached personality. Furthermore, since [(18)F]CFT binding is
thought to reflect the density of dopaminergic nerve terminals in the brain, the
authors suggest that the neurodevelopmental formation of the brain dopaminergic
system may influence adult personality traits.
PMID- 10671419
TI - Bright light therapy's effect on postpartum depression.
PMID- 10671420
TI - Risperidone treatment for psychosis in end-stage Friedreich's ataxia.
PMID- 10671421
TI - Intoxication with olanzapine.
PMID- 10671422
TI - Dextromethorphan-induced psychosis.
PMID- 10671424
TI - Cost-effectiveness of psychiatrists.
PMID- 10671425
TI - Conflicted caregivers.
PMID- 10671427
TI - Magnetic resonance imaging abnormalities and psychiatric illness.
PMID- 10671428
TI - Cost-effectiveness of psychiatrists.
PMID- 10671429
TI - Cognitive effects of testosterone supplementation.
PMID- 10671431
TI - Theoretical-clinical-empirical approach to classifying axis II disorders.
PMID- 10671434
TI - Sympathoadrenal hyperactivity and neuroleptic malignant syndrome.
PMID- 10671435
TI - Comparison of clozapine and risperidone.
PMID- 10671437
TI - Cyanobacterial cell walls: news from an unusual prokaryotic envelope.
PMID- 10671438
TI - Role of the H protein in assembly of the photochemical reaction center and
intracytoplasmic membrane in Rhodospirillum rubrum.
AB - Rhodospirillum rubrum is a model for the study of membrane formation. Under
conditions of oxygen limitation, this facultatively phototrophic bacterium forms
an intracytoplasmic membrane that houses the photochemical apparatus. This
apparatus consists of two pigment-protein complexes, the light-harvesting antenna
(LH) and photochemical reaction center (RC). The proteins of the photochemical
components are encoded by the puf operon (LHalpha, LHbeta, RC-L, and RC-M) and by
puhA (RC-H). R. rubrum puf interposon mutants do not form intracytoplasmic
membranes and are phototrophically incompetent. The puh region was cloned, and
DNA sequence determination identified open reading frames bchL and bchM and part
of bchH; bchHLM encode enzymes of bacteriochlorophyll biosynthesis. A puhA/G115
interposon mutant was constructed and found to be incapable of phototrophic
growth and impaired in intracytoplasmic membrane formation. Comparison of
properties of the wild-type and the mutated and complemented strains suggests a
model for membrane protein assembly. This model proposes that RC-H is required as
a foundation protein for assembly of the RC and highly developed intracytoplasmic
membrane. In complemented strains, expression of puh occurred under semiaerobic
conditions, thus providing the basis for the development of an expression vector.
The puhA gene alone was sufficient to restore phototrophic growth provided that
recombination occurred.
PMID- 10671439
TI - Enhanced nitrogenase activity in strains of Rhodobacter capsulatus that
overexpress the rnf genes.
AB - In the photosynthetic bacterium Rhodobacter capsulatus, a putative membrane-bound
complex encoded by the rnfABCDGEH operon is thought to be dedicated to electron
transport to nitrogenase. In this study, the whole rnf operon was cloned under
the control of the nifH promoter in plasmid pNR117 and expressed in several rnf
mutants. Complementation analysis demonstrated that transconjugants which
integrated plasmid pNR117 directed effective biosynthesis of a functionally
competent complex in R. capsulatus. Moreover, it was found that strains carrying
pNR117 displayed nitrogenase activities 50 to 100% higher than the wild-type
level. The results of radioactive labeling experiments indicated that the
intracellular content of nitrogenase polypeptides was marginally altered in
strains containing pNR117, whereas the levels of the RnfB and RnfC proteins
present in the membrane were four- and twofold, respectively, higher than the
wild-type level. Hence, the enhancement of in vivo nitrogenase activity was
correlated with a commensurate overproduction of the Rnf polypeptides. In vitro
nitrogenase assays performed in the presence of an artificial electron donor
indicated that the catalytic activity of the enzyme was not increased in strains
overproducing the Rnf polypeptides. It is proposed that the supply of reductants
through the Rnf complex might be rate limiting for nitrogenase activity in vivo.
Immunoprecipitation experiments performed on solubilized membrane proteins
revealed that RnfB and RnfC are associated with each other and with additional
polypeptides which may be components of the membrane-bound complex.
PMID- 10671440
TI - Autoinduction of 2,4-diacetylphloroglucinol biosynthesis in the biocontrol agent
Pseudomonas fluorescens CHA0 and repression by the bacterial metabolites
salicylate and pyoluteorin.
AB - The antimicrobial metabolite 2,4-diacetylphloroglucinol (2,4-DAPG) contributes to
the capacity of Pseudomonas fluorescens strain CHA0 to control plant diseases
caused by soilborne pathogens. A 2, 4-DAPG-negative Tn5 insertion mutant of
strain CHA0 was isolated, and the nucleotide sequence of the 4-kb genomic DNA
region adjacent to the Tn5 insertion site was determined. Four open reading
frames were identified, two of which were homologous to phlA, the first gene of
the 2,4-DAPG biosynthetic operon, and to the phlF gene encoding a pathway
specific transcriptional repressor. The Tn5 insertion was located in an open
reading frame, tentatively named phlH, which is not related to known phl genes.
In wild-type CHA0, 2, 4-DAPG production paralleled expression of a phlA'-'lacZ
translational fusion, reaching a maximum in the late exponential growth phase.
Thereafter, the compound appeared to be degraded to monoacetylphloroglucinol by
the bacterium. 2,4-DAPG was identified as the active compound in extracts from
culture supernatants of strain CHA0 specifically inducing phlA'-'lacZ expression
about sixfold during exponential growth. Induction by exogenous 2,4-DAPG was most
conspicuous in a phlA mutant, which was unable to produce 2, 4-DAPG. In a phlF
mutant, 2,4-DAPG production was enhanced severalfold and phlA'-'lacZ was
expressed at a level corresponding to that in the wild type with 2,4-DAPG added.
The phlF mutant was insensitive to 2,4-DAPG addition. A transcriptional phlA-lacZ
fusion was used to demonstrate that the repressor PhlF acts at the level of
transcription. Expression of phlA'-'lacZ and 2,4-DAPG synthesis in strain CHA0
was strongly repressed by the bacterial extracellular metabolites salicylate and
pyoluteorin as well as by fusaric acid, a toxin produced by the pythopathogenic
fungus Fusarium. In the phlF mutant, these compounds did not affect phlA'-'lacZ
expression and 2, 4-DAPG production. PhlF-mediated induction by 2,4-DAPG and
repression by salicylate of phlA'-'lacZ expression was confirmed by using
Escherichia coli as a heterologous host. In conclusion, our results show that
autoinduction of 2,4-DAPG biosynthesis can be countered by certain bacterial (and
fungal) metabolites. This mechanism, which depends on phlF function, may help P.
fluorescens to produce homeostatically balanced amounts of extracellular
metabolites.
PMID- 10671441
TI - Expression of a new operon from Bacillus subtilis, ykzB-ykoL, under the control
of the TnrA and PhoP-phoR global regulators.
AB - The ykzB and ykoL genes encode two peptides, of 51 and 60 amino acids, the
functions of which are unknown. The ykzB and tnrA genes are contiguous and
transcribed divergently. Expression of ykzB and ykoL is induced by glutamate and
is under the control of the TnrA global regulator of nitrogen utilization. TnrA
regulated its own synthesis in glutamate minimal medium. Two DNA sequences
(TnrAB1 and TnrAB2) homologous to the TnrA binding site are present in the region
between tnrA and ykzB. Deletion mapping indicated that the TnrAB2 binding site
was involved in activation of the ykzB promoter. In addition, transcription of
tnrA depends on the presence of the TnrAB1 binding site. The ykzB and ykoL genes
are probably in the same transcriptional unit. A single promoter involved in
transcription in the presence of glutamate was mapped by primer extension. ykoL
expression was induced by phosphate limitation and depended on the PhoP-PhoR two
component regulatory system. Its promoter was mapped to the region between ykoL
and ykzB. Four boxes similar to the PhoP binding site are present upstream from
the ykoL promoter. These boxes are probably recognized by PhoP approximately P
during the activation of transcription in phosphate limitation conditions.
PMID- 10671442
TI - Characterization and role of tbuX in utilization of toluene by Ralstonia
pickettii PKO1.
AB - The tbu regulon of Ralstonia pickettii PKO1 encodes enzymes involved in the
catabolism of toluene, benzene, and related alkylaromatic hydrocarbons. The first
operon in this regulon contains genes that encode the tbu pathway's initial
catabolic enzyme, toluene-3-monooxygenase, as well as TbuT, the NtrC-like
transcriptional activator for the entire regulon. It has been previously shown
that the organization of tbuT, which is located immediately downstream of
tbuA1UBVA2C, and the associated promoter (PtbuA1) is unique in that it results in
a cascade type of up-regulation of tbuT in response to a variety of effector
compounds. In our efforts to further characterize this unusual mode of gene
regulation, we discovered another open reading frame, encoded on the strand
opposite that of tbuT, 63 bp downstream of the tbuT stop codon. The 1,374-bp open
reading frame, encoding a 458-amino-acid peptide, was designated tbuX. The
predicted amino acid sequence of TbuX exhibited significant similarity to several
putative outer membrane proteins from aromatic hydrocarbon-degrading bacteria, as
well as to FadL, an outer membrane protein needed for uptake of long-chain fatty
acids in Escherichia coli. Based on sequence analysis, transcriptional and
expression studies, and deletion analysis, TbuX seems to play an important role
in the catabolism of toluene in R. pickettii PKO1. In addition, the expression of
tbuX appears to be regulated in a manner such that low levels of TbuX are always
present within the cell, whereas upon toluene exposure these levels dramatically
increase, even more than those of toluene-3-monooxygenase. This expression
pattern may relate to the possible role of TbuX as a facilitator of toluene entry
into the cell.
PMID- 10671443
TI - KorSA from the Streptomyces integrative element pSAM2 is a central
transcriptional repressor: target genes and binding sites.
AB - pSAM2, a 10.9-kb mobile integrative genetic element from Streptomyces
ambofaciens, possesses, as do a majority of Streptomyces conjugative plasmids, a
kil-kor system associated with its transfer. The kor function of pSAM2 was
attributed to the korSA gene, but its direct role remained unclear. The present
study was focused on the determination of the KorSA targets. It was shown that
KorSA acts as a transcriptional repressor by binding to a conserved 17-nucleotide
sequence found upstream of only two genes: its own gene, korSA, and pra, a gene
positively controlling pSAM2 replication, integration, and excision. A unique
feature of KorSA, compared to Kor proteins from other Streptomyces conjugative
plasmids, is that it does not directly regulate pSAM2 transfer. KorSA does not
bind to the pSAM2 genes coding for transfer and intramycelial spreading. Through
the repression of pra, KorSA is able to negatively regulate pSAM2 functions
activated by Pra and, consequently, to maintain pSAM2 integrated in the
chromosome.
PMID- 10671444
TI - Regulation of cold shock-induced RNA helicase gene expression in the
Cyanobacterium anabaena sp. strain PCC 7120.
AB - Expression of the Anabaena sp. strain PCC 7120 RNA helicase gene crhC is induced
by cold shock. crhC transcripts are not detectable at 30 degrees C but accumulate
at 20 degrees C, and levels remain elevated for the duration of the cold stress.
Light-derived metabolic capability, and not light per se, is required for crhC
transcript accumulation. Enhanced crhC mRNA stability contributes significantly
to the accumulation of crhC transcripts, with the crhC half-life increasing
sixfold at 20 degrees C. The accumulation is reversible, with the cells
responding more rapidly to temperature downshifts than to upshifts, as a result
of the lack of active mRNA destabilization and the continuation of crhC
transcription, at least transiently, after a temperature upshift. Translational
inhibitors do not induce crhC expression to cold shock levels, indicating that
inhibition of translation is only one of the signals required to activate the
cold shock response in Anabaena. Limited amounts of protein synthesis are
required for the cold shock-induced accumulation of crhC transcripts, as normal
levels of accumulation occur in the presence of tetracycline but are abolished by
chloramphenicol. Regulation of crhC expression may also extend to the
translational level, as CrhC protein levels do not correlate completely with the
pattern of mRNA transcript accumulation. Our experiments indicate that the
regulation of crhC transcript accumulation is tightly controlled by both
temperature and metabolic activity at the levels of transcription, mRNA
stabilization, and translation.
PMID- 10671445
TI - Identification of a chitin-binding protein secreted by Pseudomonas aeruginosa.
AB - One of the major proteins secreted by Pseudomonas aeruginosa is a 43-kDa protein,
which is cleaved by elastase into smaller fragments, including a 30-kDa and a 23
kDa fragment. The N-terminal 23-kDa fragment was previously suggested as
corresponding to a staphylolytic protease and was designated LasD (S. Park and D.
R. Galloway, Mol. Microbiol. 16:263-270, 1995). However, the sequence of the gene
encoding this 43-kDa protein revealed that the N-terminal half of the protein is
homologous to the chitin-binding proteins CHB1 of Streptomyces olivaceoviridis
and CBP21 of Serratia marcescens and to the cellulose-binding protein p40 of
Streptomyces halstedii. Furthermore, a short C-terminal fragment shows homology
to a part of chitinase A of Vibrio harveyi. The full-length 43-kDa protein could
bind chitin and was thereby protected against the proteolytic activity of
elastase, whereas the degradation products did not bind chitin. The purified 43
kDa chitin-binding protein had no staphylolytic activity, and comparison of the
enzymatic activities in the extracellular medium of a wild-type strain and a
chitin-binding protein-deficient mutant indicated that the 43-kDa protein
supports neither chitinolytic nor staphylolytic activity. We conclude that the 43
kDa protein, which was found to be produced by many clinical isolates of P.
aeruginosa, is a chitin-binding protein, and we propose to name it CbpD (chitin
binding protein D).
PMID- 10671446
TI - FabF is required for piezoregulation of cis-vaccenic acid levels and piezophilic
growth of the deep-Sea bacterium Photobacterium profundum strain SS9.
AB - To more fully explore the role of unsaturated fatty acids in high-pressure, low
temperature growth, the fabF gene from the psychrotolerant, piezophilic deep-sea
bacterium Photobacterium profundum strain SS9 was characterized and its role and
regulation were examined. An SS9 strain harboring a disruption in the fabF gene
(strain EA40) displayed growth impairment at elevated hydrostatic pressure
concomitant with diminished cis-vaccenic acid (18:1) production. However, growth
ability at elevated pressure could be restored to wild-type levels by the
addition of exogenous 18:1 to the growth medium. Transcript analysis did not
indicate that the SS9 fabF gene is transcriptionally regulated, suggesting that
the elevated 18:1 levels produced in response to pressure increase result from
posttranscriptional changes. Unlike many pressure-adapted bacterial species such
as SS9, the mesophile Escherichia coli did not regulate its fatty acid
composition in an adaptive manner in response to changes in hydrostatic pressure.
Moreover, an E. coli fabF strain was as susceptible to elevated pressure as wild
type cells. It is proposed that the SS9 fabF product, beta-ketoacyl-acyl carrier
protein synthase II has evolved novel pressure-responsive characteristics which
facilitate SS9 growth at high pressure.
PMID- 10671447
TI - Characterization of a thermostable DNA glycosylase specific for U/G and T/G
mismatches from the hyperthermophilic archaeon Pyrobaculum aerophilum.
AB - U/G and T/G mismatches commonly occur due to spontaneous deamination of cytosine
and 5-methylcytosine in double-stranded DNA. This mutagenic effect is
particularly strong for extreme thermophiles, since the spontaneous deamination
reaction is much enhanced at high temperature. Previously, a U/G and T/G mismatch
specific glycosylase (Mth-MIG) was found on a cryptic plasmid of the archaeon
Methanobacterium thermoautotrophicum, a thermophile with an optimal growth
temperature of 65 degrees C. We report characterization of a putative DNA
glycosylase from the hyperthermophilic archaeon Pyrobaculum aerophilum, whose
optimal growth temperature is 100 degrees C. The open reading frame was first
identified through a genome sequencing project in our laboratory. The predicted
product of 230 amino acids shares significant sequence homology to [4Fe-4S]
containing Nth/MutY DNA glycosylases. The histidine-tagged recombinant protein
was expressed in Escherichia coli and purified. It is thermostable and displays
DNA glycosylase activities specific to U/G and T/G mismatches with an uncoupled
AP lyase activity. It also processes U/7,8-dihydro-oxoguanine and T/7,8-dihydro
oxoguanine mismatches. We designate it Pa-MIG. Using sequence comparisons among
complete bacterial and archaeal genomes, we have uncovered a putative MIG protein
from another hyperthermophilic archaeon, Aeropyrum pernix. The unique conserved
amino acid motifs of MIG proteins are proposed to distinguish MIG proteins from
the closely related Nth/MutY DNA glycosylases.
PMID- 10671448
TI - Autophosphorylation of phosphoglucosamine mutase from Escherichia coli.
AB - Phosphoglucosamine mutase (GlmM) catalyzes the formation of glucosamine-1
phosphate from glucosamine-6-phosphate, an essential step in the pathway for UDP
N-acetylglucosamine biosynthesis in bacteria. This enzyme must be phosphorylated
to be active and acts according to a ping-pong mechanism involving glucosamine-1,
6-diphosphate as an intermediate (L. Jolly, P. Ferrari, D. Blanot, J. van
Heijenoort, F. Fassy, and D. Mengin-Lecreulx, Eur. J. Biochem. 262:202-210,
1999). However, the process by which the initial phosphorylation of the enzyme is
achieved in vivo remains unknown. Here we show that the phosphoglucosamine mutase
from Escherichia coli autophosphorylates in vitro in the presence of [(32)P]ATP.
The same is observed with phosphoglucosamine mutases from other bacterial
species, yeast N-acetylglucosamine-phosphate mutase, and rabbit muscle
phosphoglucomutase. Labeling of the E. coli GlmM enzyme with [(32)P]ATP requires
the presence of a divalent cation, and the label is subsequently lost when the
enzyme is incubated with either of its substrates. Analysis of enzyme
phosphorylation by high-pressure liquid chromatography and coupled mass
spectrometry confirms that only one phosphate has been covalently linked to the
enzyme. Only phosphoserine could be detected after acid hydrolysis of the labeled
protein, and site-directed mutagenesis of serine residues located in or near the
active site identifies the serine residue at position 102 as the site of
autophosphorylation of E. coli GlmM.
PMID- 10671449
TI - WhiD and WhiB, homologous proteins required for different stages of sporulation
in Streptomyces coelicolor A3(2).
AB - The whiD locus, which is required for the differentiation of Streptomyces
coelicolor aerial hyphae into mature spore chains, was localized by map-based
cloning to the overlap between cosmids 6G4 and D63 of the minimal ordered library
of Redenbach et al. (M. Redenbach et al., Mol. Microbiol. 21:77-96, 1996).
Subcloning and sequencing showed that whiD encodes a homologue of WhiB, a protein
required for the initiation of sporulation septation in S. coelicolor. WhiD and
WhiB belong to a growing family of small (76- to 112-residue) proteins of unknown
biochemical function in which four cysteines are absolutely conserved; all known
members of this family are found in the actinomycetes. A constructed whiD null
mutant showed reduced levels of sporulation, and those spores that did form were
heat sensitive, lysed extensively, and were highly irregular in size, arising at
least in part from irregularity in septum placement. The whiD null mutant showed
extreme variation in spore cell wall deposition; most spores had uniformly thin
(20- to 30-nm) walls, but spore chains were frequently observed in which there
was irregular but very pronounced (up to 170 nm) cell wall thickening at the
junctions between spores. whiD null mutant spores were frequently partitioned
into irregular smaller units through the deposition of additional septa, which
were often laid down in several different planes, very close to the spore poles.
These "minicompartments" appeared to be devoid of chromosomal DNA. Two whiD
promoters, whiDp1 and whiDp2, were identified, and their activities were analyzed
during development of wild-type S. coelicolor on solid medium. Both promoters
were developmentally regulated; whiDp1 and whiDp2 transcripts were detected
transiently, approximately at the time when sporulation septa were observed in
the aerial hyphae.
PMID- 10671450
TI - Differential distribution of novel restriction-modification systems in clonal
lineages of Neisseria meningitidis.
AB - Using representational difference analysis, we isolated novel meningococcal
restriction-modification (R-M) systems. NmeBI, which is a homologue of the R-M
system HgaI of Pasteurella volantium, was present in meningococci of the ET-5
complex and of lineage III. NmeAI was found in serogroup A, ET-37 complex, and
cluster A4 meningococci. NmeDI was harbored by meningococci of the ET-37 complex
and of cluster A4, but not by serogroup A meningococci. Two of the R-M systems,
NmeBI and NmeDI, were located at homologous positions between the phenylalanyl
tRNA synthetase genes pheS and pheT, which appeared to be a preferential target
for the insertion of foreign DNA in meningococci. The distribution of the three R
M systems was tested with 103 meningococcal strains comprising 49 sequence types.
The vast majority of the strains had either NmeBI, NmeAI, or both NmeAI and
NmeDI. Using cocultivation experiments, we could demonstrate that NmeBI, which
was present in ET-5 complex meningococci, was responsible for a partial
restriction of DNA transfer from meningococci of the ET-37 complex to
meningococci of the ET-5 complex.
PMID- 10671451
TI - Extracellular glycanases of Rhizobium leguminosarum are activated on the cell
surface by an exopolysaccharide-related component.
AB - Rhizobium leguminosarum secretes two extracellular glycanases, PlyA and PlyB,
that can degrade exopolysaccharide (EPS) and carboxymethyl cellulose (CMC), which
is used as a model substrate of plant cell wall cellulose polymers. When grown on
agar medium, CMC degradation occurred only directly below colonies of R.
leguminosarum, suggesting that the enzymes remain attached to the bacteria.
Unexpectedly, when a PlyA-PlyB-secreting colony was grown in close proximity to
mutants unable to produce or secrete PlyA and PlyB, CMC degradation occurred
below that part of the mutant colonies closest to the wild type. There was no CMC
degradation in the region between the colonies. By growing PlyB-secreting
colonies on a lawn of CMC-nondegrading mutants, we could observe a halo of CMC
degradation around the colony. Using various mutant strains, we demonstrate that
PlyB diffuses beyond the edge of the colony but does not degrade CMC unless it is
in contact with the appropriate colony surface. PlyA appears to remain attached
to the cells since no such diffusion of PlyA activity was observed. EPS defective
mutants could secrete both PlyA and PlyB, but these enzymes were inactive unless
they came into contact with an EPS(+) strain, indicating that EPS is required for
activation of PlyA and PlyB. However, we were unable to activate CMC degradation
with a crude EPS fraction, indicating that activation of CMC degradation may
require an intermediate in EPS biosynthesis. Transfer of PlyB to Agrobacterium
tumefaciens enabled it to degrade CMC, but this was only observed if it was grown
on a lawn of R. leguminosarum. This indicates that the surface of A. tumefaciens
is inappropriate to activate CMC degradation by PlyB. Analysis of CMC degradation
by other rhizobia suggests that activation of secreted glycanases by surface
components may occur in other species.
PMID- 10671452
TI - Partitioning of the linear chromosome during sporulation of Streptomyces
coelicolor A3(2) involves an oriC-linked parAB locus.
AB - Candidate partitioning genes (parA and parB) for the linear chromosome of
Streptomyces coelicolor were identified by DNA sequencing in a series of seven
genes located between rnpA and trxA near the chromosomal replication origin. The
most likely translation start point of parB overlapped the parA stop codon,
suggestive of coregulation, and transcription analysis suggested that the two
genes formed an operon. Deletion of part of parB had no effect on the growth or
appearance of colonies but caused a deficiency in DNA partitioning during the
multiple septation events involved in converting aerial hyphae into long chains
of spores. At least 13% of spore compartments failed to inherit the normal DNA
allocation. The same phenotype was obtained with a deletion removing a segment of
DNA from both parA and parB. Reinforcing the idea of a special role for the par
locus during sporulation, the stronger of two parAB promoters was greatly
upregulated at about the time when sporulation septation was maximal in colonies.
Three copies of a 14-bp inverted repeat (GTTTCACGTGAAAC) were found in or near
the parAB genes, and at least 12 more identical copies were identified within 100
kb of oriC from the growing genome sequence database. Only one perfect copy of
the 14-bp sequence was present in approximately 5 Mb of sequence available from
the rest of the genome. The 14-bp sequence was similar to sequences identified as
binding sites for Spo0J, a ParB homologue from Bacillus subtilis believed to be
important for DNA partitioning (D. C.-H. Lin and A. D. Grossman, Cell 92:675-685,
1998). One of these sites encompassed the transcription start point of the
stronger parA promoter.
PMID- 10671453
TI - Novel phospholipase A activity secreted by Legionella species.
AB - Bacterial phospholipases are regarded as a major virulence factor in infection.
In bacteria associated with pneumonia, destruction of lung surfactant and host
cell membranes by bacterial phospholipases secreted during infection is thought
to contribute to the disease. Phospholipase C (PLC) activity has been described
in several Legionella species (W. B. Baine, J. Gen. Microbiol. 134:489-498, 1988;
W. B. Baine, J. Gen. Microbiol. 131:1383-1391, 1985). By using detection methods
such as thin-layer chromatography and mass spectrometry, PLC activity could not
be detected in several strains of Legionella pneumophila. Instead, phospholipid
degradation was identified to be caused by a novel PLA activity. We could
demonstrate that PLA secretion starts at the mid-exponential-growth phase when
bacteria were grown in liquid culture. Several Legionella species secreted
different amounts of PLA. Legionella PLA may act as a powerful agent in the
mediation of pathogenicity due to destruction of lung surfactant and epithelial
cells.
PMID- 10671454
TI - Effect of temperature on stability and activity of elongation factor 2 proteins
from Antarctic and thermophilic methanogens.
AB - Despite the presence and abundance of archaea in low-temperature environments,
little information is available regarding their physiological and biochemical
properties. In order to investigate the adaptation of archaeal proteins to low
temperatures, we purified and characterized the elongation factor 2 (EF-2)
protein from the Antarctic methanogen Methanococcoides burtonii, which was
expressed in Escherichia coli, and compared it to the recombinant EF-2 protein
from a phylogenetically related thermophile, Methanosarcina thermophila. Using
differential scanning calorimetry to assess protein stability and enzyme assays
for the intrinsic GTPase activity, we identified biochemical and biophysical
properties that are characteristic of the cold-adapted protein. This includes a
higher activity at low temperatures caused by a decrease of the activation energy
necessary for GTP hydrolysis and a decreased activation energy for the
irreversible denaturation of the protein, which indicates a less thermostable
structure. Comparison of the in vitro properties of the proteins with the
temperature-dependent characteristics of growth of the organisms indicates that
additional cytoplasmic factors are likely to be important for the complete
thermal adaptation of the proteins in vivo. This is the first study to address
thermal adaptation of proteins from a free-living, cold-adapted archaeon, and our
results indicate that the ability of the Antarctic methanogen to adapt to the
cold is likely to involve protein structural changes.
PMID- 10671455
TI - Succinyl coenzyme A synthetase of Pseudomonas aeruginosa with a broad specificity
for nucleoside triphosphate (NTP) synthesis modulates specificity for NTP
synthesis by the 12-kilodalton form of nucleoside diphosphate kinase.
AB - Pseudomonas aeruginosa secretes copious amounts of an exopolysaccharide called
alginate during infection in the lungs of cystic fibrosis patients. A mutation in
the algR2 gene of mucoid P. aeruginosa is known to exhibit a nonmucoid
(nonalginate-producing) phenotype and showed reduced activities of succinyl
coenzyme A (CoA) synthetase (Scs) and nucleoside diphosphate kinase (Ndk),
implying coregulation of Ndk and Scs in alginate synthesis. We have cloned and
characterized the sucCD operon encoding the alpha and beta subunits of Scs from
P. aeruginosa and have studied the role of Scs in generating GTP, an important
precursor in alginate synthesis. We demonstrate that, in the presence of GDP, Scs
synthesizes GTP using ATP as the phosphodonor and, in the presence of ADP, Scs
synthesizes ATP using GTP as a phosphodonor. In the presence of inorganic
orthophosphate, succinyl-CoA, and an equimolar amount of ADP and GDP, Scs
synthesizes essentially an equimolar amount of ATP and GTP. Such a mechanism of
GTP synthesis can be an alternate source for the synthesis of alginate as well as
for the synthesis of other macromolecules requiring GTP such as RNA and protein.
Scs from P. aeruginosa is also shown to exhibit a broad NDP kinase activity. In
the presence of inorganic orthophosphate (P(i)), succinyl-CoA, and either GDP,
ADP, UDP or CDP, it synthesizes GTP, ATP, UTP, or CTP. Scs was previously shown
to copurify with Ndk, presumably as a complex. In mucoid cells of P. aeruginosa,
Ndk is also known to exist in two forms, a 16-kDa cytoplasmic form predominant in
the log phase and a 12-kDa membrane-associated form predominant in the stationary
phase. We have observed that the 16-kDa Ndk-Scs complex present in nonmucoid
cells, synthesizes all three of the nucleoside triphosphates from a mixture of
GDP, UDP, and CDP, whereas the 12-kDa Ndk-Scs complex specifically present in
mucoid cell predominantly synthesizes GTP and UTP but not CTP. Such regulation
may promote GTP synthesis in the stationary phase when the bulk of alginate is
synthesized by mucoid P. aeruginosa.
PMID- 10671456
TI - Characterization of SotA and SotB, two Erwinia chrysanthemi proteins which modify
isopropyl-beta-D-thiogalactopyranoside and lactose induction of the Escherichia
coli lac promoter.
AB - The expression, in Escherichia coli, of variants of the Erwinia chrysanthemi
secretion genes outB and outS under the Ptac promoter is toxic to the cells.
During attempts to clone E. chrysanthemi genes able to suppress this toxicity, I
identified two genes, sotA and sotB, whose products are able to reduce the
isopropyl-beta-D-thiogalactopyranoside (IPTG) induction of the E. coli lac
promoter. SotA and SotB belong to two different families of the major facilitator
superfamily. SotA is a member of the sugar efflux transporter family, while SotB
belongs to the multidrug efflux family. The results presented here suggest that
SotA and SotB are sugar efflux pumps. SotA reduces the intracellular
concentration of IPTG, lactose, and arabinose. SotB reduces the concentration of
IPTG, lactose, and melibiose. Expression of sotA and sotB is not regulated by
their substrates, but sotA is activated by the cyclic AMP receptor protein (CRP),
while sotB is repressed by CRP. Lactose is weakly toxic for E. chrysanthemi. This
toxicity is increased in a sotB mutant which cannot efficiently efflux lactose.
This first evidence for a physiological role of sugar efflux proteins suggests
that their function could be to reduce the intracellular concentration of toxic
sugars or sugar metabolites.
PMID- 10671457
TI - Feruloyl esterase activity of the Clostridium thermocellum cellulosome can be
attributed to previously unknown domains of XynY and XynZ.
AB - The cellulosome of Clostridium thermocellum is a multiprotein complex with endo-
and exocellulase, xylanase, beta-glucanase, and acetyl xylan esterase activities.
XynY and XynZ, components of the cellulosome, are composed of several domains
including xylanase domains and domains of unknown function (UDs). Database
searches revealed that the C- and N-terminal UDs of XynY and XynZ, respectively,
have sequence homology with the sequence of a feruloyl esterase of strain PC-2 of
the anaerobic fungus Orpinomyces. Purified cellulosomes from C. thermocellum were
found to hydrolyze FAXX (O-(5-O-[(E)-feruloyl]-alpha-L-arabinofuranosyl)-(1-->3)
O-beta-D- xyl opyranosyl-(1-->4)-D-xylopyranose) and FAX(3) (5-O-[(E)-feruloyl]
[O-beta-D-xylopyranosyl-(1-->2)]-O-alpha-L- arabinofuranosyl-[1-->3])-O-beta-D
xylopyranosyl-(1-->4)-D-xylopyranose) , yielding ferulic acid as a product,
indicating that they have feruloyl esterase activity. Nucleotide sequences
corresponding to the UDs of XynY and XynZ were cloned into Escherichia coli, and
the expressed proteins hydrolyzed FAXX and FAX(3). The recombinant feruloyl
esterase domain of XynZ alone (FAE(XynZ)) and with the adjacent cellulose binding
domain (FAE-CBD(XynZ)) were characterized. FAE-CBD(XynZ) had a molecular mass of
45 kDa that corresponded to the expected product of the 1,203-bp gene. K(m) and
V(max) values for FAX(3) were 5 mM and 12.5 U/mg, respectively, at pH 6.0 and 60
degrees C. PAX(3), a substrate similar to FAX(3) but with a p-coumaroyl group
instead of a feruloyl moiety was hydrolyzed at a rate 10 times slower. The
recombinant enzyme was active between pH 3 to 10 with an optimum between pH 4 to
7 and at temperatures up to 70 degrees C. Treatment of Coastal Bermuda grass with
the enzyme released mainly ferulic acid and a lower amount of p-coumaric acid.
FAE(XynZ) had similar properties. Removal of the 40 C-terminal amino acids,
residues 247 to 286, of FAE(XynZ) resulted in protein without activity. Feruloyl
esterases are believed to aid in a release of lignin from hemicellulose and may
be involved in lignin solubilization. The presence of feruloyl esterase in the C.
thermocellum cellulosome together with its other hydrolytic activities
demonstrates a powerful enzymatic potential of this organelle in plant cell wall
decomposition.
PMID- 10671458
TI - Respiration of 2,4,6-trinitrotoluene by Pseudomonas sp. strain JLR11.
AB - Under anoxic conditions Pseudomonas sp. strain JLR11 can use 2,4, 6
trinitrotoluene (TNT) as the sole N source, releasing nitrite from the aromatic
ring and subsequently reducing it to ammonium and incorporating it into C
skeletons. This study shows that TNT can also be used as a terminal electron
acceptor in respiratory chains under anoxic conditions by Pseudomonas sp. strain
JLR11. TNT-dependent proton translocation coupled to the reduction of TNT to
aminonitrotoluenes has been observed in TNT-grown cells. This extrusion did not
occur in nitrate-grown cells or in anaerobic TNT-grown cells treated with
cyanide, a respiratory chain inhibitor. We have shown that in a membrane fraction
prepared from Pseudomonas sp. strain JLR11 grown on TNT under anaerobic
conditions, the synthesis of ATP was coupled to the oxidation of molecular
hydrogen and to the reduction of TNT. This phosphorylation was uncoupled by
gramicidin. Respiration by Pseudomonas sp. strain JLR11 is potentially useful for
the biotreatment of TNT in polluted waters and soils, particularly in
phytorhizoremediation, in which bacterial cells are transported to the deepest
root zones, which are poor in oxygen.
PMID- 10671459
TI - Gene families encoding phase- and size-variable surface lipoproteins of
Mycoplasma hyorhinis.
AB - A prototype family of seven genes encoding the variable surface lipoproteins
(Vlps) of Mycoplasma hyorhinis is characterized in the pathogenic SK76 strain,
using long-range PCR to amplify and analyze the single chromosomal region
containing expressed genes vlpA to -G, each of which is subject to phase and size
variation. Smaller families of vlp genes in subclones of SK76 or in another
strain of M. hyorhinis, GDL, can be attributed to deletions of specific vlp genes
from the prototype array described here. Two genes, vlpA and the newly revealed
vlpG, contain repeat motifs in their 3' coding regions that differ from the short
tandem repeats in other vlp genes yet retain structural features common to all
vlp gene products. SK76 and GDL vlp gene families are similarly organized and
show sequence similarity between corresponding individual vlp genes. In light of
the extensive potential for diversity within the vlp gene system, such
conservation provides a provisional basis to hypothesize that vlp genes may exist
in specific arrays that endow selected functions while retaining common
structural features required during phase-variable expression of this set of gene
products.
PMID- 10671460
TI - The UspA1 protein and a second type of UspA2 protein mediate adherence of
Moraxella catarrhalis to human epithelial cells in vitro.
AB - The UspA1 and UspA2 proteins of Moraxella catarrhalis are structurally related,
are exposed on the bacterial cell surface, and migrate as very high-molecular
weight complexes in sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Previous analysis of uspA1 and uspA2 mutants of M. catarrhalis strain 035E
indicated that UspA1 was involved in adherence of this organism to Chang
conjunctival epithelial cells in vitro and that expression of UspA2 was essential
for resistance of this strain to killing by normal human serum (C. Aebi, E. R.
Lafontaine, L. D. Cope, J. L. Latimer, S. R. Lumbley, G. H. McCracken, Jr., and
E. J. Hansen, Infect. Immun. 66:3113-3119, 1998). In the present study, isogenic
uspA1, uspA2, and uspA1 uspA2 mutations were constructed in three additional M.
catarrhalis strains: 012E, TTA37, and 046E. The uspA1 mutant of strain 012E had a
decreased ability to attach to Chang cells. However, inactivation of the uspA1
gene in both strain TTA37 and strain 046E did not cause a significant decrease in
attachment ability. Inactivation of the uspA2 gene of strain TTA37 did result in
a loss of attachment ability. Nucleotide sequence analysis revealed that the
predicted protein encoded by the uspA2 genes of both strains TTA37 and 046E had a
N-terminal half that resembled the N-terminal half of UspA1 proteins, whereas the
C-terminal half of this protein was nearly identical to those of previously
characterized UspA2 proteins. The gene encoding this "hybrid" protein was
designated uspA2H. PCR-based analysis revealed that approximately 20% of M.
catarrhalis strains apparently possess a uspA2H gene instead of a uspA2 gene. The
M. catarrhalis uspA1, uspA2, and uspA2H genes were cloned and expressed in
Haemophilus influenzae cells, which were used to prove that both the UspA1 and
UspA2H proteins can function as adhesins in vitro.
PMID- 10671461
TI - Streptococcus gordonii biofilm formation: identification of genes that code for
biofilm phenotypes.
AB - Viridans streptococci, which include Streptococcus gordonii, are pioneer oral
bacteria that initiate dental plaque formation. Sessile bacteria in a biofilm
exhibit a mode of growth that is distinct from that of planktonic bacteria.
Biofilm formation of S. gordonii Challis was characterized using an in vitro
biofilm formation assay on polystyrene surfaces. The same assay was used as a
nonbiased method to screen isogenic mutants generated by Tn916 transposon
mutagenesis for defective biofilm formation. Biofilms formed optimally when
bacteria were grown in a minimal medium under anaerobic conditions. Biofilm
formation was affected by changes in pH, osmolarity, and carbohydrate content of
the growth media. Eighteen biofilm-defective mutants of S. gordonii Challis were
identified based on Southern hybridization with a Tn916-based probe and DNA
sequences of the Tn916-flanking regions. Molecular analyses of these mutants
showed that some of the genes required for biofilm formation are involved in
signal transduction, peptidoglycan biosynthesis, and adhesion. These
characteristics are associated with quorum sensing, osmoadaptation, and adhesion
functions in oral streptococci. Only nine of the biofilm-defective mutants had
defects in genes of known function, suggesting that novel aspects of bacterial
physiology may play a part in biofilm formation. Further identification and
characterization of biofilm-associated genes will provide insight into the
molecular mechanisms of biofilm formation of oral streptococci.
PMID- 10671462
TI - Substrate range and genetic analysis of Acinetobacter vanillate demethylase.
AB - An Acinetobacter sp. genetic screen was used to probe structure-function
relationships in vanillate demethylase, a two-component monooxygenase. Mutants
with null, leaky, and heat-sensitive phenotypes were isolated. Missense mutations
tended to be clustered in specific regions, most of which make known
contributions to catalytic activity. The vanillate analogs m-anisate, m-toluate,
and 4-hydroxy-3,5-dimethylbenzoate are substrates of the enzyme and weakly
inhibit the metabolism of vanillate by wild-type Acinetobacter bacteria. PCR
mutagenesis of vanAB, followed by selection for strains unable to metabolize
vanillate, yielded mutant organisms in which vanillate metabolism is more
strongly inhibited by the vanillate analogs. Thus, the procedure opens for
investigation amino acid residues that may contribute to the binding of either
vanillate or its chemical analogs to wild-type and mutant vanillate demethylases.
Selection of phenotypic revertants following PCR mutagenesis gave an indication
of the extent to which amino acid substitutions can be tolerated at specified
positions. In some cases, only true reversion to the original amino acid was
observed. In other examples, a range of amino acid substitutions was tolerated.
In one instance, phenotypic reversion failed to produce a protein with the
original wild-type sequence. In this example, constraints favoring certain
nucleotide substitutions appear to be imposed at the DNA level.
PMID- 10671463
TI - Regulation of the cnr cobalt and nickel resistance determinant from Ralstonia sp.
strain CH34.
AB - Ralstonia sp. strain CH34 is resistant to nickel and cobalt cations. Resistance
is mediated by the cnr determinant located on plasmid pMOL28. The cnr genes are
organized in two clusters, cnrYXH and cnrCBA. As revealed by reverse
transcriptase PCR and primer extension, transcription from these operons is
initiated from promoters located upstream of the cnrY and cnrC genes. These two
promoters exhibit conserved sequences at the -10 (CCGTATA) and -35 (CRAGGGGRAG)
regions. The CnrH gene product, which is required for expression of both operons,
is a sigma factor belonging to the sigma L family, whose activity seems to be
governed by the membrane-bound CnrY and CnrX gene products in response to Ni(2+).
Half-maximal activation from the cnrCBA operon was determined by using
appropriate lacZ gene fusions and was shown to occur at an Ni(2+) concentration
of about 50 microM.
PMID- 10671464
TI - Regulation of the cnr cobalt and nickel resistance determinant of Ralstonia
eutropha (Alcaligenes eutrophus) CH34.
AB - The linked resistance to nickel and cobalt of Ralstonia eutropha-like strain CH34
(Alcaligenes eutrophus CH34) is encoded by the cnr operon, which is localized on
the megaplasmid pMOL28. The regulatory genes cnrYXH have been cloned,
overexpressed, and purified in Escherichia coli. CnrY fractionated as a 10.7-kDa
protein in in vitro translation assays. CnrX, a periplasmic protein of 16.5 kDa,
was overproduced and purified as a histidine-tagged fusion protein in E. coli.
His-CnrX was found to possess a secondary structure content rich in alpha-helical
and beta-sheet structures. CnrH, a sigma factor of the extracytoplasmic function
family, was purified as an N-terminally histidine-tagged fusion. In gel shift
mobility assays, His-CnrH, in the presence of E. coli core RNA polymerase enzyme,
could retard at least two different promoter DNA targets, cnrYp and cnrHp,
localized within the cnrYXH locus. These promoters and their transcription start
sites were confirmed by primer extension. Purified His-CnrX did not inhibit the
DNA-binding activity of His-CnrH and is therefore unlikely to be an anti-sigma
factor, as previously hypothesized (EMBL M91650 description entry). To study the
transcriptional response of the regulatory locus to metals and to probe promoter
regions, transcriptional fusions were constructed between fragments of cnrYXH and
the luxCDABE, luciferase reporter genes. Nickel and cobalt specifically induced
the cnrYXH-luxCDABE fusion at optimal concentrations of 0.3 mM Ni(2+) and 2.0 mM
Co(2+) in a noncomplexing medium for metals. The two promoter regions P(Y)
(upstream cnrY) and P(H) (upstream cnrH) were probed and characterized using this
vector and were found to control the nickel-inducible regulatory response of the
cnr operon. The cnrHp promoter was responsible for full transcription of the
cnrCBA structural resistance genes, while the cnrYp promoter was necessary to
obtain metal-inducible transcription from the cnrHp promoter. The zinc resistance
phenotype (ZinB) of a spontaneous cnr mutant strain, AE963, was investigated and
could be attributed to an insertion of IS1087, a member of the IS2 family of
insertion elements, within the cnrY gene.
PMID- 10671465
TI - Influence of mutations in the mexR repressor gene on expression of the MexA-MexB
oprM multidrug efflux system of Pseudomonas aeruginosa.
AB - Several nalB-type multidrug-resistant mutants of Pseudomonas aeruginosa
overexpressed MexAB-OprM and carried mutations in the local regulatory gene,
mexR. Others, dubbed nalC types, carried mutations elsewhere and overexpressed
MexAB-OprM less extensively than the nalB strains. Available evidence showed that
MexR acted solely as repressor. Disruption of the mexR gene at various places
suggested that the 5' end of mexR may be a part of the mexAB-oprM promoter.
PMID- 10671466
TI - Physical map of the chromosome of the apple proliferation phytoplasma.
AB - A physical map of the apple proliferation phytoplasma strain AT chromosome was
constructed from genomic DNA extracted from diseased tobacco plants. The map was
generated with single and double digestions of the chromosome with BssHII, SmaI,
MluI, and ApaI restriction endonucleases and resolving the fragments by pulsed
field gel electrophoresis. Partial digestion and Southern blot analysis were used
to assist in the arrangement of the 14 contiguous restriction fragments obtained.
From the restriction fragments generated by double digestions, the size of the
circular chromosome was calculated to be approximately 645 kb. Locations of the
two rRNA operons, the operon including the fus and tuf genes, and three other
genes were placed on the map. Genome sizes and BssHII restriction profiles of
apple proliferation strain AP15 and the pear decline and European stone fruit
yellows phytoplasmas were different from that of strain AT.
PMID- 10671467
TI - Effects of calcium and calcium chelators on growth and morphology of Escherichia
coli L-form NC-7.
AB - Growth of a wall-less, L-form of Escherichia coli specifically requires calcium,
and in its absence, cells ceased dividing, became spherical, swelled, developed
large vacuoles, and eventually lysed. The key cell division protein, FtsZ, was
present in the L-form at a concentration five times less than that in the
parental strain. One interpretation of these results is that the L-form possesses
an enzoskeleton partly regulated by calcium.
PMID- 10671468
TI - Cpx two-component signal transduction in Escherichia coli: excessive CpxR-P
levels underlie CpxA* phenotypes.
AB - In Escherichia coli, the CpxA-CpxR two-component signal transduction system and
the sigma(E) and sigma(32) response pathways jointly regulate gene expression in
adaptation to adverse conditions. These include envelope protein distress, heat
shock, oxidative stress, high pH, and entry into stationary phase. Certain mutant
versions of the CpxA sensor protein (CpxA* proteins) exhibit an elevated ratio of
kinase to phosphatase activity on CpxR, the cognate response regulator. As a
result, CpxA* strains display numerous phenotypes, many of which cannot be easily
related to currently known functions of the CpxA-CpxR pathway. It is unclear
whether CpxA* phenotypes are caused solely by hyperphosphorylation of CpxR. We
here report that all of the tested CpxA* phenotypes depend on elevated levels of
CpxR-P and not on cross-signalling of CpxA* to noncognate response regulators.
PMID- 10671469
TI - Requirement for homologous recombination functions for expression of the mutA
mistranslator tRNA-induced mutator phenotype in Escherichia coli.
AB - Expression of the Escherichia coli mutA mutator phenotype requires recA, recB,
recC, ruvA, and ruvC gene, but not recD, recF, recO, or recR genes. Thus, the
recBCD-dependent homologous recombination system is a component of the signal
pathway that activates an error-prone DNA polymerase in mutA cells.
PMID- 10671470
TI - Novel missense mutations that affect the transport function of MalK, the ATP
binding-cassette subunit of the Salmonella enterica serovar typhimurium maltose
transport system.
AB - We report on novel mutations in the malK gene of Salmonella enterica serovar
Typhimurium, encoding the ATPase subunit of the maltose transporter (MalFGK(2)).
Biochemical analysis suggests that (i) L86 might be involved in a signaling step
during substrate translocation and (ii) E306 may be critical for the structural
integrity of the protein.
PMID- 10671471
TI - Mutational analysis of ligand recognition by tcp, the citrate chemoreceptor of
Salmonella enterica serovar typhimurium.
AB - The chemoreceptor Tcp mediates taxis to citrate. To identify citrate-binding
residues, we substituted cysteine for seven basic or polar residues that are
chosen based on the comparison of Tcp with the well-characterized chemoreceptors.
The results suggest that Arg-63, Arg-68, Arg-72, Lys-75, and Tyr-150 (and
probably other unidentified residues) are involved in the recognition of citrate.
PMID- 10671472
TI - Cytochrome c' from Rhodobacter capsulatus confers increased resistance to nitric
oxide.
AB - We report the cloning and sequencing of the gene containing cytochrome c' (cycP)
from the photosynthetic purple bacterium Rhodobacter capsulatus and the regions
flanking that gene. Mutant strains unable to synthesize cytochrome c' had
increased sensitivity to nitrosothiols and to nitric oxide (which binds to the
heme moiety of cytochrome c').
PMID- 10671473
TI - Utilization of subsidiary chromosomal replication terminators in Bacillus
subtilis.
AB - The Bacillus subtilis merodiploid strain GSY1127 contains a large nontandem
duplication of a portion of its chromosome within its left (anticlockwise)
replication segment. This causes displacement of the replication terminus region
to a noticeably asymmetric location relative to oriC. The utilization of the
subsidiary replication terminators, TerIII and TerV, in the merodiploid strain
has been compared with that in B. subtilis 168. It is shown that TerIII is
utilized to a significant extent in GSY1127 and that TerV is used only marginally
at the most. Neither of these terminators is used to a measurable extent in the
168 strain. It is concluded that TerIII and TerV do indeed function as backups to
the major terminator TerI, as has been generally thought. It is further concluded
that, in the 168 strain, the vast majority of clockwise forks are arrested at the
highly efficient TerI terminator, with fork fusion between the approaching forks
occurring frequently while the clockwise fork is stationary at TerI.
PMID- 10671474
TI - Stress triggers a process that limits activation of the Bacillus subtilis stress
transcription factor sigma(B).
AB - Stress-induced activation of the Bacillus subtilis transcription factor sigma(B)
is transitory. To determine whether the process that limits sigma(B) activation
is itself triggered by stress, B. subtilis strains in which the stress pathway
was artificially activated by the induced expression of a positive regulatory
protein (RsbT) were exposed to ethanol stress and were monitored for the
persistence of sigma(B) activity. Without ethanol treatment, the induced cultures
displayed continuously high sigma(B) activity. Ethanol treatment restricted
ongoing sigma(B) activity, but only in strains with intact rsbX and -S genes. The
loss of other gene products (RsbR and Obg) known to participate in the stress
activation pathway had little influence in blocking the ethanol effect. The data
argue that stress upregulates the activity of the RsbX-S regulatory pair to
restrict sigma(B) induction following stress.
PMID- 10671475
TI - A tripartite nuclear localization signal in the PDZ-domain protein L-periaxin.
AB - The murine Periaxin gene encodes two PDZ-domain proteins in myelin-forming
Schwann cells of the vertebrate peripheral nervous system (Dytrych, L., Sherman,
D. L., Gillespie, C. S., and Brophy, P. J. (1998) J. Biol. Chem. 273, 5794-5800).
Here we show that L-periaxin is targeted to the nucleus of embryonic Schwann
cells. Subsequently, the protein redistributes to the plasma membrane processes
of the myelinating Schwann cell where it is believed to function in a signaling
complex. In contrast, L-periaxin remains in the nucleus when expressed
ectopically in oligodendrocytes, the myelin-forming glia of the central nervous
system. The nuclear localization signal (NLS) is basic and tripartite and
comprises three signals that act synergistically. Nuclear targeting of L-periaxin
is energy-dependent and is inhibited by cell-cell contact. These data show that L
periaxin is a member of a growing family of proteins that can shuttle between the
nucleus and cortical signaling/adherence complexes.
PMID- 10671476
TI - Activation of human T lymphocytes is inhibited by peroxisome proliferator
activated receptor gamma (PPARgamma) agonists. PPARgamma co-association with
transcription factor NFAT.
AB - T lymphocyte activation is highlighted by the induction of interleukin-2 (IL-2)
gene expression, which governs much of the early lymphocyte proliferation
responses. Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a
member of the nuclear receptor superfamily of ligand-activated transcription
factors. PPARgamma mRNA expression was found in human peripheral blood T
lymphocytes, raising the possibility of PPARgamma involvement in the regulation
of T cell function. Here we show that PPARgamma ligands, troglitazone and 15
deoxy-Delta(12,14) prostaglandin J(2), but not PPARalpha agonist Wy14643,
inhibited IL-2 production and phytohemagglutinin-inducible proliferation in human
peripheral blood T-cells in a dose-dependent manner. This inhibitory effect on IL
2 was restricted to the PPARgamma2-expressing, not the PPARgamma-lacking,
subpopulation of transfected Jurkat cells. The activated PPARgamma physically
associates with transcriptional factor NFAT regulating the IL-2 promoter,
blocking NFAT DNA binding and transcriptional activity. This interaction with T
cell-specific transcription factors indicates an important immunomodulatory role
for PPARgamma in T lymphocytes and could suggest a previously unrecognized
clinical potential for PPARgamma ligands as immunotherapeutic drugs to treat T
cell-mediated diseases by targeting IL-2 gene expression.
PMID- 10671477
TI - Stimulation of slow skeletal muscle fiber gene expression by calcineurin in vivo.
AB - Adult skeletal muscle fibers can be categorized into fast and slow twitch
subtypes based on specialized contractile and metabolic properties and on
distinctive patterns of muscle gene expression. Muscle fiber-type characteristics
are dependent on the frequency of motor nerve stimulation and are thought to be
controlled by calcium-dependent signaling. The calcium, calmodulin-dependent
protein phosphatase, calcineurin, stimulates slow fiber-specific gene promoters
in cultured skeletal muscle cells, and the calcineurin inhibitor, cyclosporin A,
inhibits slow fiber gene expression in vivo, suggesting a key role of calcineurin
in activation of the slow muscle fiber phenotype. Calcineurin has also been shown
to induce hypertrophy of cardiac muscle and to mediate the hypertrophic effects
of insulin-like growth factor-1 on skeletal myocytes in vitro. To determine
whether activated calcineurin was sufficient to induce slow fiber gene expression
and hypertrophy in adult skeletal muscle in vivo, we created transgenic mice that
expressed activated calcineurin under control of the muscle creatine kinase
enhancer. These mice exhibited an increase in slow muscle fibers, but no evidence
for skeletal muscle hypertrophy. These results demonstrate that calcineurin
activation is sufficient to induce the slow fiber gene regulatory program in vivo
and suggest that additional signals are required for skeletal muscle hypertrophy.
PMID- 10671478
TI - Isolation, structural characterization, and bioactivity of a novel neuromedin U
analog from the defensive skin secretion of the Australasian tree frog, Litoria
caerulea.
AB - We report the isolation of a novel bioactive peptide, neuromedin U-23 (NmU-23),
from the defensive skin secretion of the Australasian tree frog, Litoria
caerulea. The primary structure of the peptide was established by a combination
of microsequencing, mass spectroscopy and site-directed antiserum
immunoreactivity as SDEEVQVPGGVISNGYFLFRPRN-amide (M(r) 2580.6). A synthetic
replicate of frog NmU-23 displaced monoradioiodinated rat NmU-23 from uterine
membranes in a dose-dependent fashion indistinguishable from nonisotopically
labeled rat NmU-23. In a rat uterine smooth muscle strip preparation, synthetic
frog NmU-23 produced dose-dependent contractions identical to porcine NmU-25.
However, in a preparation of human urinary bladder muscle strip, the synthetic
frog peptide was more potent than porcine NmU-25 in eliciting contraction and
produced desensitization of the preparation to the latter peptide. This report
demonstrates that the defensive skin secretion of a frog contains a novel peptide
exhibiting a high degree of primary structural similarity to the endogenous
vertebrate peptide, NmU, and that this frog skin analog displays biological
activity in mammalian tissues.
PMID- 10671479
TI - Fhit-nucleotide specificity probed with novel fluorescent and fluorogenic
substrates.
AB - Fhit, a member of the histidine triad superfamily of nucleotide-binding proteins,
binds and cleaves diadenosine polyphosphates and functions as a tumor suppressor
in human epithelial cancers. Function of Fhit in tumor suppression does not
require diadenosine polyphosphate cleavage but correlates with the ability to
form substrate complexes. As diadenosine polyphosphates are at lower cellular
concentrations than mononucleotides, we sought to quantify interactions between
Fhit and competitive inhibitors with the use of diadenosine polyphosphate analogs
containing fluorophores in place of one nucleoside. Appp-S-(7-diethylamino-4
methyl-3-(4-succinimidylphenyl)) coumarin (ApppAMC), Appp-S-(4-4-difluoro-5,7
dimethyl-4-bora-3a, 4a-diaza-s-indacine-3-yl) methylaminoacetyl (ApppBODIPY), and
GpppBODIPY, synthesized in high yield, are effective Fhit substrates, producing
AMP or GMP plus fluorophore diphosphates. GpppBODIPY cleavage is accompanied by a
5.4-fold increase in fluorescence because BODIPY fluorescence is quenched by
stacking with guanine. Titration of unlabeled diadenosine polyphosphates,
inorganic pyrophosphate, mononucleotides, and inorganic phosphate into
fluorescent assays provided values of K(m) and K(I) as competitive inhibitors.
The data indicate that Fhit discriminates between good substrates via k(cat) and
against cellular competitors in equilibrium binding terms. Surprisingly,
pyrophosphate competes better than purine mononucleotides.
PMID- 10671480
TI - Plasma membrane calcium channels in human carcinoma A431 cells are functionally
coupled to inositol 1,4,5-trisphosphate receptor-phosphatidylinositol 4,5
bisphosphate complexes.
AB - In most nonexcitable cells, calcium (Ca(2+)) release from inositol 1,4,5
trisphosphate (InsP(3))-sensitive intracellular Ca(2+) stores is coupled to
Ca(2+) influx (calcium release-activated channels (I(CRAC))) pathway. Despite
intense investigation, the molecular identity of I(CRAC) and the mechanism of its
activation remain poorly understood. InsP(3)-dependent miniature calcium channels
(I(min)) display functional properties characteristic for I(CRAC). Here we used
patch clamp recordings of I(min) channels in human carcinoma A431 cells to
demonstrate that I(min) activity was greatly enchanced in the presence of anti
phosphatidylinositol 4, 5-bisphosphate antibody (PIP(2)Ab) and diminished in the
presence of PIP(2). Anti-PIP(2) antibody induced a greater than 6-fold increase
in I(min) sensitivity for InsP(3) activation and an almost 4-fold change in
I(min) maximal open probability. The addition of exogenous PIP(2) vesicles to the
cytosolic surface of inside-out patches inhibited I(min) activity. These results
lead us to propose an existence of a Ca(2+) influx pathway in nonexcitable cells
activated via direct conformational coupling with a selected population of
InsP(3) receptors, located just underneath the plasma membrane and coupled to
PIP(2). The described pathway provides for a highly compartmentalized Ca(2+)
influx and intracellular Ca(2+) store refilling mechanism.
PMID- 10671481
TI - Temperature-dependent chaperone activity and structural properties of human
alphaA- and alphaB-crystallins.
AB - The chaperone activity and biophysical properties of recombinant human alphaA-
and alphaB-crystallins were studied by light scattering and spectroscopic
methods. While the chaperone function of alphaA-crystallin markedly improves with
an increase in temperature, the activity of alphaB homopolymer appears to change
very little upon heating. Compared with alphaB-crystallin, the alphaA-homopolymer
is markedly less active at low temperatures, but becomes a more active species at
high temperatures. At physiologically relevant temperatures, the alphaB
homopolymer appears to be modestly (two times or less) more potent chaperone than
alphaA homopolymer. In contrast to very similar thermotropic changes in the
secondary structure of both homopolymers, alphaA- and alphaB-crystallins markedly
differ with respect to the temperature-dependent surface hydrophobicity profiles.
Upon heating, alphaA-crystallin undergoes a conformational transition resulting
in the exposure of additional hydrophobic sites, whereas no such transition
occurs for alphaB-crystallin. The correlation between temperature-dependent
changes in the chaperone activity and hydrophobicity properties of the individual
homopolymers supports the view that the chaperone activity of alpha-crystallin is
dependent on the presence of surface-exposed hydrophobic patches. However, the
present data also show that the surface hydrophobicity is not the sole
determinant of the chaperone function of alpha-crystallin.
PMID- 10671483
TI - Studies on the interleukin-6-type cytokine signal transducer gp130 reveal a novel
mechanism of receptor activation by monoclonal antibodies.
AB - The transmembrane glycoprotein gp130 belongs to the family of hematopoietic
cytokine receptors. It represents the common signal transducing receptor
component of the so called interleukin-6-type cytokines. For several cytokine
receptors including gp130 it has been shown that receptor activation cannot only
be achieved by the natural ligand but also by single monoclonal antibodies raised
against the receptor ectodomain. These findings have been interpreted in a way
that dimerization of cytokine receptors is sufficient for receptor activation.
Here we show that the recently described gp130-activating antibody B-S12 actually
consists of two different monoclonal antibodies. By subcloning of B-S12 the
monoclonal antibodies B-S12-A5 and B-S12-G7 were obtained. The individual
antibodies are biologically inactive, in combination they exert B-S12-like
activity on hepatoma cells. On Ba/F3 cells stably transfected with gp130 a
combination of B-S12-G7 with another monoclonal gp130 antibody, B-P8, is required
to stimulate proliferation. Using gp130 deletion mutants we show that all three
antibodies map to domains 2 and 3 of gp130 which constitute the cytokine binding
module. The individual antibodies inhibit activation of the signal transducer by
interleukin-6 and interfere with binding of interleukin-6 to gp130.
Interestingly, the combination of B-S12-G7 and a Fab fragment of B-P8 retains
biological activity. We conclude from our data that (i) the monoclonal antibodies
activate gp130 by mimicking the natural ligand and (ii) enforcement of gp130
dimerization is not sufficient for receptor activation but additional
conformational requirements have to be fulfilled.
PMID- 10671482
TI - Identification of Cox20p, a novel protein involved in the maturation and assembly
of cytochrome oxidase subunit 2.
AB - We have identified Cox20p, a 23.8-kDa protein of the mitochondrial inner membrane
that is involved in the biogenesis of the yeast cytochrome oxidase complex.
Cytochrome oxidase subunit 2 (Cox2p) accumulates as a precursor in cox20 mutants,
suggesting a defect in biogenesis of this mitochondrially encoded protein. The
inability of cox20 mutants to process the subunit 2 precursor (pCox2p) is not due
to impaired export of the protein across the inner membrane or to an inactive
Imp1p/Imp2p peptidase. Rather, Cox20p specifically binds the newly synthesized
pCox2p, a step required to present the exported pCox2p as a substrate to the
Imp1p peptidase. All of the endogenous pCox2p accumulated in an Deltaimp1 mutant,
and a small fraction of Cox2p in wild type yeast, is detected in a complex with
Cox20p. Following maturation Cox2p remained associated with Cox20p, prior to
assembling into the cytochrome oxidase complex. We propose that Cox20p acts as a
membrane-bound chaperone necessary for cleavage of pCox2p and for interaction of
the mature protein with other subunits of cytochrome oxidase in a later step of
the assembly process.
PMID- 10671484
TI - Partial occlusion of both cavities of the eukaryotic chaperonin with antibody has
no effect upon the rates of beta-actin or alpha-tubulin folding.
AB - The eukaryotic chaperonin containing T-complex polypeptide 1 (CCT) is required in
vivo for the production of native actin and tubulin. It is a 900-kDa oligomer
formed from two back-to-back rings, each containing eight different subunits
surrounding a central cavity in which interactions with substrates are thought to
occur. Here, we show that a monoclonal antibody recognizing the C terminus of the
CCTalpha subunit can bind inside, and partially occlude, both cavities of apo
CCT. Rabbit reticulocyte lysate was programmed to synthesize beta-actin and alpha
tubulin in the presence and absence of anti-CCTalpha antibody. The binding of the
antibody inside the cavity and its occupancy of a large part of it does not
prevent the folding of beta-actin and alpha-tubulin by CCT, despite the fact that
all the CCT in the in vitro translation reactions was continuously bound by two
antibody molecules. Furthermore, no differences in the protease susceptibility of
actin bound to CCT in the presence and absence of the monoclonal antibody were
detected, indicating that the antibody molecules do not perturb the conformation
of actin folding intermediates substantially. These data indicate that complete
sequestration of substrate by CCT may not be required for productive folding,
suggesting that there are differences in its folding mechanism compared with the
Group I chaperonins.
PMID- 10671485
TI - Trypsin stimulates integrin alpha(5)beta(1)-dependent adhesion to fibronectin and
proliferation of human gastric carcinoma cells through activation of proteinase
activated receptor-2.
AB - Trypsin is widely expressed in various non-pancreatic tissues at low levels and
overexpressed in some types of human cancers. In the present study, we found that
trypsin stimulates integrin-dependent adhesion and growth of MKN-1 human gastric
carcinoma cells. MKN-1 cells expressed both proteinase-activated receptor-1 (PAR
1) and PAR-2, which are activated by thrombin and trypsin, respectively. Both
trypsin and the PAR-2 ligand SLIGKV promoted integrin alpha(5)beta(1)-mediated
adhesion of MKN-1 cells to fibronectin, and less effectively integrin
alpha(v)beta(3)-mediated cell adhesion to vitronectin, but not that to type IV
collagen or laminin-1 at all. Thrombin and the PAR-1 ligand SFLLRN promoted the
cell adhesion to vitronectin more strongly than trypsin or the PAR-2 ligand, but
not the cell adhesion to fibronectin at all. The cell adhesion-stimulating effect
of the PAR-2 ligand was significantly reduced by the pre-treatment of cells with
trypsin, indicating that the effect of trypsin is mediated by PAR-2 activation.
The trypsin-stimulated cell adhesion to vitronectin, but not to fibronectin, was
effectively inhibited by the G(i) protein blocker pertussis toxin, and both cell
adhesions were completely inhibited by the Src kinase inhibitor herbimycin A.
Furthermore, trypsin and the PAR-2 ligand stimulated growth of MKN-1 cells more
strongly than thrombin or the PAR-1 ligand. These results show that trypsin
regulates cellular adhesion and proliferation by inducing PAR-2/G protein
signalings, and that the integrin alpha(5)beta(1)- and integrin alpha(v)beta(3)
dependent cell adhesions are regulated by different PAR/G protein signalings.
PMID- 10671486
TI - Elucidation of the structural features of heparan sulfate important for
interaction with the Hep-2 domain of fibronectin.
AB - The interaction of fibronectin with cell surface heparan sulfate proteoglycans is
important biologically in inducing reorganization of the cytoskeleton and the
assembly of focal adhesions. The major heparan sulfate-binding site in
fibronectin, which is also implicated in these morphological events, is the COOH
terminal Hep-2 domain. We describe the first extensive study of the structural
determinants required for the interaction between heparan sulfate/heparin and Hep
2. It is clear that, in heparan sulfate, there is a very prominent role for N
sulfate groups, as opposed to a relatively small apparent contribution from
carboxyl groups. Furthermore, a minimal octasaccharide binding sequence appeared
to contain at least two 2-O-sulfated iduronate residues, but no 6-O-sulfate
groups. However, affinity was enhanced by the presence of 6-O-sulfates, and the
interaction with Hep-2 also increased progressively with oligosaccharide size up
to a maximum length of a tetradecasaccharide. This overall specificity is
compatible with recent information on the structure of Hep-2 (Sharma, A., Askari,
J. A., Humphries, M. J., Jones, E. Y., and Stuart, D. I. (1999) EMBO J. 18, 1468
1479) in which two separate, positively charged clusters, involving up to 11
basic amino acid residues (mostly arginines with their preferential ability to co
ordinate sulfate groups), could form a single extended binding site.
PMID- 10671487
TI - GLUTX1, a novel mammalian glucose transporter expressed in the central nervous
system and insulin-sensitive tissues.
AB - Based on homology with GLUT1-5, we have isolated a cDNA for a novel glucose
transporter, GLUTX1. This cDNA encodes a protein of 478 amino acids that shows
between 29 and 32% identity with rat GLUT1-5 and 32-36% identity with plant and
bacterial hexose transporters. Unlike GLUT1-5, GLUTX1 has a short extracellular
loop between transmembrane domain (TM) 1 and TM2 and a long extracellular loop
between TM9 and TM10 that contains the only N-glycosylation site. When expressed
in Xenopus oocytes, GLUTX1 showed strong transport activity only after
suppression of a dileucine internalization motif present in the amino-terminal
region. Transport activity was inhibited by cytochalasin B and partly competed by
D-fructose and D-galactose. The Michaelis-Menten constant for glucose was
approximately 2 mM. When translated in reticulocytes lysates, GLUTX1 migrates as
a 35-kDa protein that becomes glycosylated in the presence of microsomal
membranes. Western blot analysis of GLUTX1 transiently expressed in HEK293T cells
revealed a diffuse band with a molecular mass of 37-50 kDa that could be
converted to a approximately 35-kDa polypeptide following enzymatic
deglycosylation. Immunofluorescence microscopy detection of GLUTX1 transfected
into HEK293T cells showed an intracellular staining. Mutation of the dileucine
internalization motif induced expression of GLUTX1 at the cell surface. GLUTX1
mRNA was detected in testis, hypothalamus, cerebellum, brainstem, hippocampus,
and adrenal gland. We hypothesize that, in a similar fashion to GLUT4, in vivo
cell surface expression of GLUTX1 may be inducible by a hormonal or other
stimulus.
PMID- 10671488
TI - The ubiquitin-related BAG-1 provides a link between the molecular chaperones
Hsc70/Hsp70 and the proteasome.
AB - The BAG-1 protein modulates the chaperone activity of Hsc70 and Hsp70 in the
mammalian cytosol and nucleus. Remarkably, BAG-1 possesses a ubiquitin-like
domain at its amino terminus, suggesting a link to the ubiquitin/proteasome
system. Here we show that BAG-1 is indeed associated with the 26 S proteasome in
HeLa cells. Binding of the chaperone cofactor to the proteolytic complex is
regulated by ATP hydrolysis and is not mediated by Hsc70 and Hsp70. The presented
findings reveal a role of BAG-1 as a physical link between the Hsc70/Hsp70
chaperone system and the proteasome. In fact, targeting of BAG-1 to the
proteasome promotes an association of the chaperones with the proteolytic complex
in vitro and in vivo. A regulatory function of the chaperone cofactor at the
interface between protein folding and protein degradation is thus indicated.
PMID- 10671489
TI - A redox mechanism controls differential DNA binding activities of hypoxia
inducible factor (HIF) 1alpha and the HIF-like factor.
AB - Hypoxia-inducible factor 1alpha (HIF-1alpha) and the HIF-like factor (HLF) are
two highly related basic Helix-Loop-Helix/Per-Arnt-Sim (bHLH/PAS) homology
transcription factors that undergo dramatically increased function at low oxygen
levels. Despite strong similarities in their activation mechanisms (e.g. they
both undergo rapid hypoxia-induced protein stabilization, bind identical target
DNA sequences, and induce synthetic reporter genes to similar degrees), they are
both essential for embryo survival via distinct functions during vascularization
(HIF-1alpha) or catecholamine production (HLF). It is currently unknown how such
specificity of action is achieved. We report here that DNA binding by HLF, but
not by HIF-1alpha, is dependent upon reducing redox conditions. In vitro DNA
binding and mammalian two-hybrid assays showed that a unique cysteine in the DNA
binding basic region of HLF is a target for the reducing activity of redox factor
Ref-1. Although the N-terminal DNA-binding domain of HIF-1alpha can function in
the absence of Ref-1, we found that the C-terminal region containing the
transactivation domain requires Ref-1 for full activity. Our data reveal that the
hypoxia-inducible factors are subject to complex redox control mechanisms that
can target discrete regions of the proteins and are the first to establish a
discriminating control mechanism for differential regulation of HIF-1alpha and
HLF activity.
PMID- 10671490
TI - Function of the membrane fusion protein, MexA, of the MexA, B-OprM efflux pump in
Pseudomonas aeruginosa without an anchoring membrane.
AB - Resistance of Pseudomonas aeruginosa to multiple species of antibiotics is
largely attributable to expression of the MexA, B-OprM efflux pump. The MexA
protein is thought to be located at the inner membrane and has been assumed to
link the xenobiotics-exporting subunit, MexB, and the outer membrane channel
protein, OprM. To verify this assumption, we analyzed membrane anchoring and
localization of the MexA protein. n-[9, 10-(3)H]Palmitic acid incorporation
experiments revealed that MexA was radiolabeled with palmitic acid, suggesting
that the MexA anchors the inner membrane via the fatty acid moiety. To evaluate
the role of lipid modification and inner membrane anchoring, we substituted
cysteine 24 with phenylalanine or tyrosine and tested whether or not these mutant
MexAs function properly. When the mutant mexAs were expressed in the strain
lacking chromosomal mexA in the presence of n-[9,10-(3)H]palmitic acid, we found
undetectable radiolabeling at the MexA band. These transformants restored
antibiotic resistance to the level of the wild-type strain, indicating that lipid
modification is not essential for MexA function. These mutant strains contained
both processed and unprocessed forms of the MexA proteins. Cellular fractionation
experiments revealed that an unprocessed form of MexA anchored the inner membrane
probably via an uncleaved signal sequence, whereas the processed form was
undetectable in the membrane fraction. To assure that the lipid-free MexA
polypeptide could be unbound to the membrane, we analyzed the two-dimensional
membrane topology by the gene fusion technique. A total of 78 mexA-blaM fusions
covering the entire MexA polypeptide were constructed, and all fusion sites were
shown to be located at the periplasm. To answer the question of whether or not
membrane anchoring is essential for the MexA function, we replaced the signal
sequence of the MexA protein with that of the azurin protein, which contains a
cleavable signal sequence but no lipid modification site. The signal sequence of
the azurin-MexA hybrid protein was properly processed and bore the mature MexA,
which was fully recovered in the soluble fraction. The transformant, which
expressed azurin-MexA hybrid protein restored the antibiotic resistance to a
level indistinguishable from that of the wild-type strain. We concluded from
these results that the MexA protein is fully functional as expressed in the
periplasmic space without anchoring the inner membrane. This finding questioned
the assumption that the membrane fusion proteins connect the inner and outer
membranes.
PMID- 10671491
TI - N(alpha)-acetylation and proteolytic activity of the yeast 20 S proteasome.
AB - N(alpha)-acetylation, catalyzed co-translationally with N(alpha)
acetyltransferase (NAT), is the most common modifications of eukaryotic proteins.
In yeast, there are at least three NATs: NAT1, MAK3, and NAT3. The 20 S
proteasome subunits were purified from the normal strain and each of the deletion
mutants, nat1, mak3, and nat3. The electrophoretic mobility of these subunits was
compared by two-dimensional gel electrophoresis. Shifts toward the alkaline side
of the gel and unblocking of the N terminus of certain of the subunits in one or
another of the mutants indicated that the alpha1, alpha2, alpha3, alpha4, alpha7,
and beta3 subunits were acetylated with NAT1, the alpha5 and alpha6 subunits were
acetylated with MAK3, and the beta4 subunit was acetylated with NAT3.
Furthermore, the Ac-Met-Phe-Leu and Ac-Met-Phe-Arg termini of the alpha5 and
alpha6 subunits, respectively, extended the known types of MAK3 substrates. Thus,
nine subunits were N (alpha)-acetylated, whereas the remaining five were
processed, resulting in the loss of the N-terminal region. The 20 S proteasomes
derived from either the nat1 mutant or the normal strain were similar in respect
to chymotrypsin-like, trypsin-like, and peptidylglutamyl peptide hydrolyzing
activities in vitro, suggesting that N(alpha)-acetylation does not play a major
functional role in these activities. However, the chymotrypsin-like activity in
the absence of sodium dodecyl sulfate was slightly higher in the nat1 mutant than
in the normal strain.
PMID- 10671492
TI - The low M(r) protein-tyrosine phosphatase is involved in Rho-mediated
cytoskeleton rearrangement after integrin and platelet-derived growth factor
stimulation.
AB - The low molecular weight protein-tyrosine phosphatase (LMW-PTP) is an enzyme that
is involved in the early events of platelet-derived growth factor (PDGF) receptor
signal transduction. In fact, LMW-PTP is able to specifically bind and
dephosphorylate activated PDGF receptor, thus modulating PDGF-induced
mitogenesis. In particular, LMW-PTP is involved in pathways that regulate the
transcription of the immediately early genes myc and fos in response to growth
factor stimulation. Recently, we have found that LMW-PTP exists constitutively in
cytosolic and cytoskeleton-associated localization and that, after PDGF
stimulation, c-Src is able to bind and phosphorylate LMW-PTP only in the
cytoskeleton-associated fraction. As a consequence of its phosphorylation, LMW
PTP increases its catalytic activity about 20-fold. In this study, our interest
was to investigate the role of LMW-PTP phosphorylation in cellular response to
PDGF stimulation. To address this issue, we have transfected in NIH-3T3 cells a
mutant form of LMW-PTP in which the c-Src phosphorylation sites (Tyr(131) and
Tyr(132)) were mutated to alanine. We have established that LMW-PTP
phosphorylation by c-Src after PDGF treatment strongly influences both cell
adhesion and migration. In addition, we have discovered a new LMW-PTP substrate
localized in the cytoskeleton that becomes tyrosine-phosphorylated after PDGF
treatment: p190Rho-GAP. Hence, LMW-PTP plays multiple roles in PDGF receptor
mediated mitogenesis, since it can bind and dephosphorylate PDGF receptor, and,
at the same time, the cytoskeleton-associated LMW-PTP, through the regulation of
the p190Rho-GAP phosphorylation state, controls the cytoskeleton rearrangement in
response to PDGF stimulation.
PMID- 10671493
TI - Potent growth inhibition of leukemic cells by novel ribbon-type antisense
oligonucleotides to c-myb1.
AB - We studied the effects of antisense oligonucleotides (AS oligos) with a novel
structure. The AS oligos were covalently closed to avoid exonuclease activities
by enzymatic ligation of two identical molecules. The AS oligos of a ribbon type
(RiAS oligos) consist of two loops containing multiple antisense sequences and a
stem connecting the two loops. Three antisense sequences targeting different
binding sites were placed in a loop that was designed to form a minimal secondary
structure by itself. RiAS oligos were found to be stable because they largely
preserved their structural integrity after 24 h incubation in the presence of
either exonuclease III or serums. When a human promyelocytic cell line, HL-60,
was treated with RiAS oligos to c-myb, c-myb expression was effectively ablated.
Cell growth was inhibited by >90% determined by both the 3-[4,5-dimethythiazol-2
yl]-2,5-diphenyltetrazolium bromide assay and [(3)H]thymidine incorporation.
Further, when the leukemic cell line K562 was treated with c-myb RiAS oligos,
colony formation on soft agarose was reduced by 92 +/- 2%. These results suggest
that RiAS oligos may be employed for developing molecular antisense drugs as well
as for the functional study of a gene.
PMID- 10671494
TI - Inhibition of the Staphylococcus aureus NADPH-dependent enoyl-acyl carrier
protein reductase by triclosan and hexachlorophene.
AB - Enoyl-acyl carrier protein reductase (FabI) plays a determinant role in
completing cycles of elongation in type II fatty acid synthase systems and is an
important target for antibacterial drugs. The FabI component of Staphylococcus
aureus (saFabI) was identified, and its properties were compared with Escherichia
coli FabI (ecFabI). ecFabI and saFabI had similar specific activities, and saFabI
expression complemented the E. coli fabI(Ts) mutant, illustrating that the Gram
positive FabI was interchangeable with the Gram-negative FabI enzyme. However,
ecFabI was specific for NADH, whereas saFabI exhibited specific and positive
cooperative binding of NADPH. Triclosan and hexachlorophene inhibited both ecFabI
and saFabI. The triclosan-resistant ecFabI(G93V) protein was also refractory to
hexachlorophene inhibition, illustrating that both drugs bind at the FabI active
site. Both the introduction of a plasmid expressing the safabI gene or a missense
mutation in the chromosomal safabI gene led to triclosan resistance in S. aureus;
however, these strains did not exhibit cross-resistance to hexachlorophene. The
replacement of the ether linkage in triclosan by a carbon bridge in
hexachlorophene prevented the formation of a stable FabI-NAD(P)(+)-drug ternary
complex. Thus, the formation of this ternary complex is a key determinant of the
antibacterial activity of FabI inhibitors.
PMID- 10671495
TI - Essential role of phosphoinositide 3-kinase in leptin-induced K(ATP) channel
activation in the rat CRI-G1 insulinoma cell line.
AB - The mechanism by which leptin increases ATP-sensitive K(+) (K(ATP)) channel
activity was investigated using the insulin-secreting cell line, CRI-G1.
Wortmannin and LY 294002, inhibitors of phosphoinositide 3-kinase (PI3-kinase),
prevented activation of K(ATP) channels by leptin. The inositol phospholipids
phosphatidylinositol bisphosphate and phosphatidylinositol trisphosphate
(PtdIns(3,4,5)P(3)) mimicked the effect of leptin by increasing K(ATP) channel
activity in whole-cell and inside-out current recordings. LY 294002 prevented
phosphatidylinositol bisphosphate, but not PtdIns(3,4,5)P(3), from increasing
K(ATP) channel activity, consistent with the latter lipid acting as a membrane
associated messenger linking leptin receptor activation and K(ATP) channels.
Signaling cascades, activated downstream from PI 3-kinase, utilizing
PtdIns(3,4,5)P(3) as a second messenger and commonly associated with insulin and
cytokine action (MAPK, p70 ribosomal protein-S6 kinase, stress-activated protein
kinase 2, p38 MAPK, and protein kinase B), do not appear to be involved in leptin
mediated activation of K(ATP) channels in this cell line. Although
PtdIns(3,4,5)P(3) appears a plausible and attractive candidate for the messenger
that couples K(ATP) channels to leptin receptor activation, direct measurement of
PtdIns(3,4,5)P(3) demonstrated that insulin, but not leptin, increased global
cellular levels of PtdIns(3,4,5)P(3). Possible mechanisms to explain the
involvement of PI 3-kinases in K(ATP) channel regulation are discussed.
PMID- 10671496
TI - Identification of two major sites in the type I interleukin-1 receptor
cytoplasmic region responsible for coupling to pro-inflammatory signaling
pathways.
AB - Type I interleukin-1 receptor is the prototype for a family of proteins, which
play a central role in early responses to injury and infection. The similarity of
function across the family is reflected in similarity in signaling: all members
tested couple to activation of NFkappaB and stress kinases. The coupling to these
pathways is mediated by a 200-residue intracellular domain (the Toll/interleukin
1 receptor domain), in which sequence conservation is primarily confined to three
short motifs (boxes 1, 2, and 3) located at amino acid residue positions 10 (box
1), 60 (box 2), and 170 (box 3). We have analyzed the contribution of these
motifs to function by alanine scanning mutagenesis of the human interleukin-1
receptor type I. Mutant receptors were tested for expression, ligand binding,
activation of receptor-associated kinase(s), NFkappaB, stress kinases, and
transcription. Mutations in all three motifs led to low cell surface expression.
Mutants in box 3 were, however, wild type for signaling, whereas mutants in boxes
1 and 2 were defective. We conclude that the conserved motifs box 1 and box 2
mediate the coupling of molecules in the family to inflammation signaling
pathways.
PMID- 10671497
TI - Regulation of cytochrome bd expression in the obligate aerobe Azotobacter
vinelandii by CydR (Fnr). Sensitivity to oxygen, reactive oxygen species, and
nitric oxide.
AB - Azotobacter vinelandii is an obligately aerobic bacterium in which aerotolerant
nitrogen fixation requires cytochrome bd. Regulation of cytochrome bd expression
is achieved by CydR (an Fnr homologue), which represses transcription of the
oxidase genes cydAB. cydAB mRNA was mapped by primer extension; the
transcriptional start site was determined, and putative -10 and -35 regions were
deduced. Two "CydR boxes," one at the +1 site and one upstream of the -35 region,
were identified. Transcriptionally inactive, purified CydR was converted, by
adding NifS, cysteine, and Fe(2+), into an active form possessing acid-labile
sulfide and spectra suggesting a [4Fe-4S](2+) cluster. Reconstituted CydR
specifically bound both CydR boxes cooperatively, with higher affinity for the
nearer consensus +1 site. Low concentrations of O(2) or NO ([O(2)]/[[CydR] or
[NO]/[CydR] = 0.1-0. 6) elicited loss of the 420 nm absorbance attributed to the
[4Fe-4S](2+) cluster, formation of a 315 nm species, and loss of ability to
retard DNA migration. Retardation by reconstituted CydR was enhanced by
superoxide dismutase and/or catalase, suggesting a role for reactive oxygen
species in CydR inactivation. The role of CydR in regulating cydAB expression in
the supposedly anoxic cytoplasm of A. vinelandii and similarities to cydAB
regulation by Fnr in Escherichia coli are discussed.
PMID- 10671498
TI - Molecular aspects of complement-mediated bacterial killing. Periplasmic
conversion of C9 from a protoxin to a toxin.
AB - As part of the membrane attack complex complement protein C9 is responsible for
direct killing of bacteria. Here we show that in the periplasmic space of an
Escherichia coli cell C9 is converted from a protoxin to a toxin by periplasmic
conditions missing in spheroplasts. This conversion is independent of the pathway
by which C9 enters the periplasm. Both, C9 shocked into the periplasm and plasmid
expressed C9 targeted to the periplasm via a signal sequence are toxic. Toxicity
requires disulfide-linked C9 because export into the periplasm of cells defective
in disulfide bond synthesis (dsbA and dsbB mutants) is not toxic unless N
acetylcysteine is added externally to promote cystines. A N-terminal fragment,
C9[1-144], is not toxic nor is cytoplasmically expressed C9, even in trxB mutants
that are able to form disulfide bonds in the cytoplasm. Importantly, expression
of full-length C9 in complement-resistant cells has no effect on their viability.
Expression and translocation into the periplasm may provide a novel model to
identify molecular mechanisms of other bactericidal disulfide-linked proteins and
to investigate the nature of bacterial complement resistance.
PMID- 10671499
TI - Gbetagamma-dependent phosphoinositide 3-kinase activation in hearts with in vivo
pressure overload hypertrophy.
AB - Activation of phosphoinositide 3-kinases is coupled to both
phosphotyrosine/growth factor and G protein-coupled receptors. We explored the
role of phosphoinositide 3-kinase activation in myocardium during in vivo
pressure overload hypertrophy in mice. Cytosolic extracts from wild type
hypertrophied hearts showed a selective increase in the phosphoinositide 3-kinase
gamma isoform. To address the role of G protein-coupled receptor-mediated
activation of phosphoinositide 3-kinase, we used transgenic mice with cardiac
specific overexpression of a Gbetagamma sequestering peptide. Extracts from
hypertrophied transgenic hearts showed complete loss of phosphoinositide 3-kinase
activation, indicating a Gbetagamma-dependent process. To determine the class of
G proteins that contribute Gbetagamma dimers for in vivo phosphoinositide 3
kinase activation, two strategies were used: 1) transgenic mice with cardiac
specific overexpression of a G(q) inhibitor peptide and 2) pertussis toxin
treatment prior to pressure overload in wild type mice. Pressure overloaded G(q)
inhibitor transgenic mice showed a complete absence of phosphoinositide 3-kinase
activation, whereas pretreatment with pertussis toxin showed robust
phosphoinositide 3-kinase activation. Taken together, these data demonstrate that
activation of the phosphoinositide 3-kinase during in vivo pressure overload
hypertrophy is Gbetagamma-dependent and the Gbetagamma dimers arise from
stimulation of G(q)-coupled receptors.
PMID- 10671500
TI - Evidence for intersubunit communication during acetyl-CoA cleavage by the
multienzyme CO dehydrogenase/acetyl-CoA synthase complex from Methanosarcina
thermophila. Evidence that the beta subunit catalyzes C-C and C-S bond cleavage.
AB - The carbon monoxide dehydrogenase/acetyl-CoA synthase (CODH/ACS) from
Methanosarcina thermophila is part of a five-subunit complex consisting of alpha,
beta, gamma, delta, and epsilon subunits. The multienzyme complex catalyzes the
reversible oxidation of CO to CO(2), transfer of the methyl group of acetyl-CoA
to tetrahydromethanopterin (H(4)MPT), and acetyl-CoA synthesis from CO, CoA, and
methyl-H(4)MPT. The alpha and epsilon subunits are required for CO oxidation. The
gamma and delta subunits constitute a corrinoid iron-sulfur protein that is
involved in the transmethylation reaction. This work focuses on the beta subunit.
The isolated beta subunit contains significant amounts of nickel. When proteases
truncate the beta subunit, causing the CODH/ACS complex to dissociate, the amount
of intact beta subunit correlates directly with the EPR signal intensity of
Cluster A and the activity of the CO/acetyl-CoA exchange reaction. Our results
strongly indicate that the beta subunit harbors Cluster A, a NiFeS cluster, that
is the active site of acetyl-CoA cleavage and assembly. Although the beta subunit
is necessary, it is not sufficient for acetyl-CoA synthesis; interactions between
the CODH and the ACS subunits are required for cleavage or synthesis of the C-C
bond of acetyl-CoA. We propose that these interactions include intramolecular
electron transfer reactions between the CODH and ACS subunits.
PMID- 10671501
TI - LexA repressor forms stable dimers in solution. The role of specific dna in
tightening protein-protein interactions.
AB - Cooperativity in the interactions among proteins subunits and DNA is crucial for
DNA recognition. LexA repressor was originally thought to bind DNA as a monomer,
with cooperativity leading to tighter binding of the second monomer. The main
support for this model was a high value of the dissociation constant for the LexA
dimer (micromolar range). Here we show that the protein is a dimer at nanomolar
concentrations under different conditions. The reversible dissociation of LexA
dimer was investigated by the effects of hydrostatic pressure or urea, using
fluorescence emission and polarization to monitor the dissociation process. The
dissociation constant lies in the picomolar range (lower than 20 pM). LexA
monomers associate with an unusual large volume change (340 ml/mol), indicating
the burial of a large surface area upon dimerization. Whereas nonspecific DNA has
no stabilizing effect, specific DNA induces tightening of the dimer and a 750
fold decrease in the K(d). In contrast to the previous model, a tight dimer
rather than a monomer is the functional repressor. Accordingly, the LexA dimer
only loses its ability to recognize a specific DNA sequence by RecA-induced
autoproteolysis. Our work provides insights into the linkage between protein
protein interactions, DNA recognition, and DNA repair.
PMID- 10671502
TI - Enhancement of (45)Ca(2+) influx and voltage-dependent Ca(2+) channel activity by
beta-amyloid-(1-40) in rat cortical synaptosomes and cultured cortical neurons.
Modulation by the proinflammatory cytokine interleukin-1beta.
AB - Beta-amyloid protein is thought to underlie the neurodegeneration associated with
Alzheimer's disease by inducing Ca(2+)-dependent apoptosis. Elevated neuronal
expression of the proinflammatory cytokine interleukin-1beta is an additional
feature of neurodegeneration, and in this study we demonstrate that interleukin
1beta modulates the effects of beta-amyloid on Ca(2+) homeostasis in the rat
cortex. beta-Amyloid-(1-40) (1 microM) caused a significant increase in
(45)Ca(2+) influx into rat cortical synaptosomes via activation of L- and N-type
voltage-dependent Ca(2+) channels and also increased the amplitude of N- and P
type Ca(2+) channel currents recorded from cultured cortical neurons. In
contrast, interleukin-1beta (5 ng/ml) reduced the (45)Ca(2+) influx into cortical
synaptosomes and inhibited Ca(2+) channel activity in cultured cortical neurons.
Furthermore, the stimulatory effects of beta-amyloid protein on Ca(2+) influx
were blocked following exposure to interleukin-1beta, suggesting that interleukin
1beta may govern neuronal responses to beta-amyloid by regulating Ca(2+)
homeostasis.
PMID- 10671503
TI - Inhibition of the RelA(p65) NF-kappaB subunit by Egr-1.
AB - Induction of transcription from the human immunodeficiency virus 1 long terminal
repeat by the RelA (p65) NF-kappaB subunit has been shown to be dependent upon an
interaction with the zinc finger DNA-binding domain of Sp1. It was unknown,
however, whether NF-kappaB could also interact with other zinc finger-containing
transcription factors. In this study we demonstrate that the early growth
response transcription factor Egr-1, whose DNA-binding domain shares a high
degree of homology with that of Sp1, can also interact with RelA in vitro and
regulate NF-kappaB transcriptional activity in vivo. Similar to the interaction
with Sp1, the Rel homology domain of RelA interacts with the zinc finger domain
of Egr-1. Surprisingly, and in contrast to Sp1, Egr-1 specifically represses RelA
transcriptional activity through its zinc finger domain. Moreover, the
interaction between RelA and the Egr-1 zinc fingers is mutually exclusive with
DNA binding suggesting a model in which Egr-1 directly sequesters NF-kappaB from
its target promoters. Because Egr-1 is induced by many of the same stimuli that
activate NF-kappaB, this novel transcriptional regulatory mechanism has many
implications for the involvement of both factors in cellular processes such as
apoptosis and the response to stress and infection.
PMID- 10671504
TI - Different sterol regulatory element-binding protein-1 isoforms utilize distinct
co-regulatory factors to activate the promoter for fatty acid synthase.
AB - Sterol regulatory element-binding proteins (SREBPs) activate genes of cholesterol
and fatty acid metabolism. In each case, a ubiquitous co-regulatory factor that
binds to a neighboring recognition site is also required for efficient promoter
activation. It is likely that gene- and pathway-specific regulation by the
separate SREBP isoforms is dependent on subtle differences in how the individual
proteins function with specific co-regulators to activate gene expression. In the
studies reported here we extend these observations significantly by demonstrating
that SREBPs are involved in both sterol regulation and carbohydrate activation of
the FAS promoter. We also demonstrate that the previously implicated Sp1 site is
largely dispensable for sterol regulation in established cultured cells, whereas
a CCAAT-binding factor/nuclear factor Y is critically important. In contrast,
carbohydrate activation of the FAS promoter in primary hepatocytes is dependent
upon SREBP and both the Sp1 and CCAAT-binding factor/nuclear factor Y sites.
Because 1c is the predominant SREBP isoform expressed in hepatocytes and 1a is
more abundant in sterol depleted established cell lines, this suggests that the
different SREBP isoforms utilize distinct co-regulatory factors to activate
target gene expression.
PMID- 10671505
TI - The monoclonal antibody 1F6 identifies a pH-dependent conformational change in
the hydrophilic NH(2) terminus of NhaA Na(+)/H(+) antiporter of Escherichia coli.
AB - One of the most interesting properties of the NhaA Na(+)/H(+) antiporter of
Escherichia coli is the strong regulation of its activity by pH. This regulation
is accompanied by a conformational change that can be probed by digestion with
trypsin and involves the hydrophilic loop connecting the transmembrane helices
VIII-IX. In the present work we show that a monoclonal antibody (mAb), 1F6,
recognizes yet another domain of NhaA in a pH-dependent manner. This antibody
binds NhaA at pH 8.5 but not at pH 4.5, whereas two other mAbs bind to NhaA
independently of pH. The epitope of mAb 1F6 was located at the NH(2) terminus of
NhaA by probing proteolytic fragments in Western blot analysis and amino acid
sequencing. The antibody bound to the peptide HLHRFFSS, starting at the third
amino acid of NhaA. A synthetic peptide with this sequence was shown to bind mAb
1F6 both at acidic and alkaline pH suggesting that this peptide is accessible to
mAb 1F6 in the native protein only at alkaline pH. Although slightly shifted to
acidic pH, the pH profile of the binding of mAb 1F6 to the antiporter is similar
to that of both the Na(+)/H(+) antiporter activity as well as to its sensitivity
to trypsin. We thus suggest that these pH profiles reflect a pH-dependent
conformational change, which leads to activation of the antiporter. Indeed, a
replacement of Gly-338 by Ser (G338S), which alleviates the pH dependence of both
the NhaA activity as well as its sensitivity to trypsin, affects in a similar
pattern the binding of mAb 1F6 to NhaA. Furthermore, the binding site of mAb 1F6
is involved in the functioning of the antiporter as follows: a double Cys
replacement H3C/H5C causes an acidic shift by half a pH unit in the pH dependence
of the antiporter; N-ethylmaleimide, which does not inhibit the wild-type
protein, inhibits H3C/H5C antiporter to an extent similar to that exerted by mAb
1F6.
PMID- 10671506
TI - Stereospecificity of hydrogen abstraction in the conversion of arachidonic acid
to 15R-HETE by aspirin-treated cyclooxygenase-2. Implications for the alignment
of substrate in the active site.
AB - The initial and rate-limiting step in prostaglandin biosynthesis is
stereoselective removal of the pro-S hydrogen from the 13-carbon of arachidonic
acid. This is followed by oxygenation at C-11, formation of the five-membered
ring, and a second oxygenation at C-15 to yield the endoperoxide product,
prostaglandin G(2). Aspirin treatment of cyclooxygenase-2 is known to acetylate
an active site serine, block prostaglandin biosynthesis, and give 15R
hydroxyeicosatetraenoic acid (15R-HETE) as the only product. 15R-HETE and
prostaglandins have opposite stereoconfigurations of the 15-hydroxyl. To
understand the changes that lead to 15R-HETE synthesis in aspirin-treated COX-2,
we employed pro-R- and pro-S-labeled [13-(3)H]arachidonic acids to investigate
the selectivity of the initial hydrogen abstraction. Remarkably, aspirin-treated
COX-2 formed 15R-HETE with removal of the pro-S hydrogen at C-13 (3-9% retention
of pro-S tritium label), the same stereoselectivity as in the formation of
prostaglandins by native cyclooxygenase. To account for this result and the
change in oxygenase specificity, we suggest that the bulky serine acetyl group
forces a realignment of the omega end of the arachidonic acid carbon chain. This
can rationalize abstraction of the C-13 pro-S hydrogen, the blocking of
prostaglandin synthesis, and the formation of 15R-HETE as the sole enzymatic
product.
PMID- 10671507
TI - Characterization of chimeric lipopolysaccharides from Escherichia coli strain
JM109 transformed with lipooligosaccharide synthesis genes (lsg) from Haemophilus
influenzae.
AB - Previously, we reported the expression of chimeric lipopolysaccharides (LPS) in
Escherichia coli strain JM109 (a K-12 strain) transformed with plasmids
containing Haemophilus influenzae lipooligosaccharide synthesis genes (lsg) (Abu
Kwaik, Y., McLaughlin, R. E., Apicella, M. A., and Spinola, S. M. (1991) Mol.
Microbiol. 5, 2475-2480). In this current study, we have analyzed the O
deacylated LPS and free oligosaccharides from three transformants (designated
pGEMLOS-4, pGEMLOS-5, and pGEMLOS-7) by matrix-assisted laser desorption
ionization, electrospray ionization, and tandem mass spectrometry techniques,
along with composition and linkage analyses. These data show that the chimeric
LPS consist of the complete E. coli LPS core structure glycosylated on the 7
position of the non-reducing terminal branch heptose with oligosaccharides from
H. influenzae. In pGEMLOS-7, the disaccharide Gal1--> 3GlcNAc1--> is added, and
in pGEMLOS-5, the structure is extended to Gal1-->4GlcNAc1-->3Gal1-->3GlcNAc1-->.
PGEMLOS-5 LPS reacts positively with monoclonal antibody 3F11, an antibody that
recognizes the terminal disaccharide of lacto-N-neotetraose. In pGEMLOS-4 LPS,
the 3F11 epitope is apparently blocked by glycosylation on the 6-position of the
terminal Gal with either Gal or GlcNAc. The biosynthesis of these chimeric LPS
was found to be dependent on a functional wecA (formerly rfe) gene in E. coli. By
using this carbohydrate expression system, we have been able to examine the
functions of the lsg genes independent of the effects of other endogenous
Haemophilus genes and expressed proteins.
PMID- 10671508
TI - Transport and processing of endogenously synthesized ApoE on the macrophage cell
surface.
AB - We have previously established the presence of a pool of apoE sequestered on the
macrophage cell surface by demonstrating its displacement from a cell monolayer
at 4 degrees C. In this series of experiments, we use a cell surface
biotinylation protocol to directly quantitate apoE on the macrophage cell surface
and evaluate its transport to and from this cell surface pool. In human monocyte
derived macrophages labeled to equilibrium and in a mouse macrophage cell line
transfected to constitutively express human apoE3, approximately 8% of total
cellular apoE was present on the surface, but only a portion of this surface pool
served as a direct precursor to secreted apoE. The half-life of apoE on the
macrophage cell surface was calculated to be approximately 12 min. On SDS
polyacrylamide gel electrophoresis, the apoE isolated from the surface fraction
of cells labeled to equilibrium migrated in an isoform pattern distinct from that
observed from the intracellular fraction, with the surface fraction migrating
predominantly in a higher molecular weight isoform. Pulse labeling experiments
demonstrated that newly synthesized apoE reached the cell surface by 10 min but
was predominantly in a low molecular weight isoform. There was also a lag between
appearance of apoE on the cell surface and its appearance in the medium.
Biotinylated apoE, which accumulated in the medium, even from pulse labeled
cells, was predominantly in the high molecular weight isoform. Additional
experiments demonstrated that low molecular weight apoE present on the cell
surface was modified to higher molecular weight apoE by the addition of sialic
acid residues prior to secretion and that this conversion was inhibited by
brefeldin A. These results demonstrate an unexpected complexity in the transport
and cellular processing of macrophage cell surface apoE. Factors that modulate
the size and turnover of the cell surface pool of apoE in the macrophage remain
to be identified and investigated.
PMID- 10671509
TI - Oxidized low density lipoproteins regulate synthesis of monkey aortic smooth
muscle cell proteoglycans that have enhanced native low density lipoprotein
binding properties.
AB - Oxidized low density lipoproteins (Ox-LDL) affect several biological processes
involved in atherogenesis. However, it is not known whether Ox-LDL can regulate
proteoglycan expression and thus affect arterial wall lipoprotein retention. This
study evaluated whether Ox-LDL, as compared with native LDL, regulates
proteoglycan expression by monkey arterial smooth muscle cells in vitro and
whether proteoglycans synthesized in the presence of Ox-LDL exhibit altered
lipoprotein binding properties. Ox-LDL stimulated glycosaminoglycan synthesis, as
measured by (35)SO(4) incorporation, by 30-50% over that of native LDL. The
effect was maximal after 72 h of exposure to 5 microg/ml of Ox-LDL. The molecular
sizes of versican, biglycan, and decorin increased in response to Ox-LDL, as
indicated by size exclusion chromatography and SDS-polyacrylamide gel
electrophoresis. These effects could be mimicked by the lipid extract of Ox-LDL.
These size increases were largely due to chain elongation and not to alterations
in the ratio of (35)SO(4) to [(3)H]glucosamine incorporation. Affinity
chromatography indicated that Ox-LDL stimulated the synthesis of proteoglycans
with high affinity for native LDL. Ox-LDL also specifically stimulated mRNA
expression for biglycan (but not versican or decorin), which was correlated with
increased expression of secreted biglycan. Thus, Ox-LDL may influence lipoprotein
retention by regulating synthesis of biglycan and also by altering
glycosaminoglycan synthesis of vascular proteoglycans so as to enhance
lipoprotein binding properties.
PMID- 10671510
TI - Protein stability and domain topology determine the transcriptional activity of
the mammalian glial cells missing homolog, GCMb.
AB - The glial cells missing (GCM) family of transcription factors consists of
Drosophila GCM and the mammalian proteins GCMa and GCMb. They are expressed in a
highly restricted manner during development and are known or assumed to be
important regulators of developmental fate decisions. As the biochemical
properties of GCMb have not been studied so far, we have undertaken a detailed
structure-function analysis of the mouse GCMb (mGCMb) protein. DNA-binding
specificity was very similar to that of other GCM proteins. Nevertheless, mGCMb
was only a weak transcriptional activator in a number of different tissue culture
systems. Interestingly, this was not due to an intrinsic absence of
transactivation potential. In effect, we were able to identify two separate
transactivation domains within mGCMb, one carboxyl-terminally adjacent to the DNA
binding domain and the second within the extreme carboxyl terminus. Activity of
both transactivation domains was, however, modulated by an inhibitory region
unique to mGCMb and located between the two transactivation domains. Furthermore,
pulse-chase experiments proved that the mGCMb protein has a half-life
approximately four times shorter than mGCMa. Introduction of the above mentioned
inhibitory domain of mGCMb into mGCMa shortened the half-life of mGCMa to a value
typical of mGCMb with a concomitant reduction in transactivation potential. Given
the strong correlation between protein stability and transactivation potential,
functional differences between the two mammalian GCM homologs are likely due to
differences in stability with a single inhibitory region in mGCMb being involved
in the reduction of both.
PMID- 10671511
TI - Group V phospholipase A(2)-mediated oleic acid mobilization in lipopolysaccharide
stimulated P388D(1) macrophages.
AB - P388D(1) macrophages prelabeled with [(3)H]arachidonic acid (AA) respond to
bacterial lipopolysaccharide (LPS) by mobilizing AA in a process that takes
several hours and is mediated by the concerted actions of the group IV cytosolic
phospholipase A(2) and the group V secretory phospholipase A(2) (sPLA(2)). Here
we show that when the LPS-activated cells are prelabeled with [(3)H]oleic acid
(OA), they also mobilize and release OA to the extracellular medium. The time and
concentration dependence of the LPS effect on OA release fully resemble those of
the AA release. Experiments in which both AA and OA release are measured
simultaneously indicate that AA is released 3 times more efficiently than OA.
Importantly, LPS-stimulated OA release is strongly inhibited by the selective
sPLA(2) inhibitors 3-(3-acetamide-1-benzyl-2-ethylindolyl-5-oxy)propane sulfonic
acid and carboxymethylcellulose-linked phosphatidylethanolamine. The addition of
exogenous recombinant sPLA(2) to the cells also triggers OA release. These data
implicate a functionally active sPLA(2) as being essential for the cells to
release OA upon stimulation with LPS. OA release is also inhibited by methyl
arachidonyl fluorophosphonate but not by bromoenol lactone, indicating that the
group IV cytosolic phospholipase A(2) is also involved in the process. Together,
these data reveal that OA release occurs during stimulation of the P388D(1)
macrophages by LPS and that the regulatory features of the OA release are
strikingly similar to those previously found for the AA release.
PMID- 10671512
TI - Characterization of the insulin-regulated endocytic recycling mechanism in 3T3-L1
adipocytes using a novel reporter molecule.
AB - The endocytic trafficking of the GLUT4 glucose transporter and the insulin
regulated aminopeptidase (IRAP) are regulated by insulin. We have used a chimera
between the intracellular domain of IRAP and the extracellular and transmembrane
domains of the transferrin receptor (vpTR) to characterize IRAP-like trafficking
in 3T3-L1 adipocytes. Our data demonstrate that the cytoplasmic domain of IRAP is
sufficient to target vpTR to the insulin-regulated, slow recycling pathway in
adipocytes and that the dynamic retention of vpTR is dependent on a di-leucine
motif. Our kinetic analysis demonstrates that vpTR recycles as a single kinetic
pool and that vpTR is very efficiently sorted from endosomes to the insulin
regulated recycling pathway. An implication of these findings is that the key
step in the dynamic retention of vpTR occurs within the early endosomal system.
We have previously shown that vpTR is trafficked by an insulin-regulated pathway
in Chinese hamster ovary cells (Johnson, A. O., Subtil, A., Petrush, R.,
Kobylarz, K., Keller, S., and Mc Graw, T. E. (1998) J. Biol. Chem. 273, 17968
17977). The behavior of vpTR in Chinese hamster ovary cells is similar to its
behavior in 3T3-L1 adipocytes. The main difference is that insulin has a larger
effect on the trafficking of vpTR in the adipocytes. We concluded that the
insulin-regulated slow recycling endocytic mechanism is expressed in many
different cell types and therefore is not a unique characteristic of cells that
express GLUT4.
PMID- 10671513
TI - Regulation of tumor cell chemotaxis by type IV collagen is mediated by a Ca(2+)
dependent mechanism requiring CD47 and the integrin alpha(V)beta(3).
AB - Studies from our laboratories demonstrated that synthetic peptides from the non
collagenous (NC-1) domain of the alpha3 (IV) chain of type IV collagen (COL IV)
enhanced tumor cell adhesion (Han, J., Ohno, N., Monboisse, J. C., Pasco, S.,
Borel, J. P., and Kefalides, N. A. (1997) J. Biol. Chem. 272, 20395-20401). We
have isolated the receptors for the alpha3(IV)185-203 peptide from melanoma and
prostate tumor cells and identified them as CD47/integrin-associated protein and
the integrin alpha(V)beta(3) (Shahan, T. A., Ziaie, Z., Pasco, S., Fawzi, A.,
Bellon, G., Monboisse, J. C., and Kefalides, N. A. (1999) Cancer Res. 59, 4584
4590). In the present study we have examined the effect of CD47 and the integrin
alpha(V)beta(3) on in vitro tumor cell chemotaxis and Ca(2+)(i) modulation in
response to COL IV, from the anterior lens capsule (ALC-COL IV) and peptides from
its NC-1 domain. COL IV as well as the alpha3(IV) peptide promoted tumor cell
chemotaxis with an immediate increase in intracellular [Ca(2+)]. Treating tumor
cells with CD47 and integrin alpha(V)beta(3)-reactive antibodies reduced
chemotaxis as well as the rise in [Ca(2+)](i) in response to ALC-COL IV or the
alpha3(IV)185-203 peptide but not to Engelbreth-Holm-Swarm-COL IV or fibronectin.
The alpha3(IV)185-203 synthetic peptide stimulated an increase in calcium from
intracellular stores exclusively, whereas ALC-COL IV, Engelbreth-Holm-Swarm-COL
IV, and fibronectin stimulated Ca(2+) flux from both internal and external
stores. Furthermore, treatment of the cells with Ca(2+) chelator bis-(O
aminophenoxyl)ethane-N,N,N',N'-tetraaceticacid- acetomethoxy ester inhibited
chemotaxis toward both ALC-COL IV and the alpha3(IV)185-203 peptide. These data
indicate that CD47 and integrin alpha(V)beta(3) regulate tumor cell chemotaxis in
response to COL IV and the alpha3(IV)185-203 peptide through a Ca(2+)-dependent
mechanism.
PMID- 10671514
TI - Differential regulation of the phosphatidylinositol 3-kinase/Akt and p70 S6
kinase pathways by the alpha(1A)-adrenergic receptor in rat-1 fibroblasts.
AB - Phosphatidylinositol (PI) 3-kinase and its downstream effector Akt are thought to
be signaling intermediates that link cell surface receptors to p70 S6 kinase. We
examined the effect of a G(q)-coupled receptor on PI 3-kinase/Akt signaling and
p70 S6 kinase activation using Rat-1 fibroblasts stably expressing the human
alpha(1A)-adrenergic receptor. Treatment of the cells with phenylephrine, a
specific alpha(1)-adrenergic receptor agonist, activated p70 S6 kinase but did
not activate PI 3-kinase or any of the three known isoforms of Akt. Furthermore,
phenylephrine blocked the insulin-like growth factor-I (IGF-I)-induced activation
of PI 3-kinase and the phosphorylation and activation of Akt-1. The effect of
phenylephrine was not confined to signaling pathways that include insulin
receptor substrate-1, as the alpha(1)-adrenergic receptor agonist also inhibited
the platelet-derived growth factor-induced activation of PI 3-kinase and Akt-1.
Although increasing the intracellular Ca(2+) concentration with the ionophore
A23187 inhibited the activation of Akt-1 by IGF-I, Ca(2+) does not appear to play
a role in the phenylephrine-mediated inhibition of the PI 3-kinase/Akt pathway.
The differential ability of phenylephrine and IGF-I to activate Akt-1 resulted in
a differential ability to protect cells from UV-induced apoptosis. These results
demonstrate that activation of p70 S6 kinase by the alpha(1A)-adrenergic receptor
in Rat-1 fibroblasts occurs in the absence of PI 3-kinase/Akt signaling.
Furthermore, this receptor negatively regulates the PI 3-kinase/Akt pathway,
resulting in enhanced cell death following apoptotic insult.
PMID- 10671515
TI - A hemoglobin with an optical function.
AB - Hemoglobins are best known as oxygen transport proteins. Here we describe a
hemoglobin from the parasitic nematode Mermis nigrescens (Mn-GLB-E) that has an
optical, light shadowing function. The protein accumulates to high concentration
as intracellular crystals in the ocellus of mature phototactic adult females
while also being expressed at low concentration in other tissues. It differs in
sequence and expression pattern from Mn-GLB-B, a second Mermis globin. It retains
the structure and oxygen-binding and light-absorbing properties typical of
nematode hemoglobins. As such, recruitment to a shadowing role in the eye appears
to have occurred by changes in expression without modification of biochemistry.
Both globins are coded by genes interrupted by two introns at the conserved
positions B12.2 and G7.0, which is in agreement with the 3exon/2intron pattern
model of globin gene evolution.
PMID- 10671516
TI - Proton delivery in NO reduction by fungal nitric-oxide reductase. Cryogenic
crystallography, spectroscopy, and kinetics of ferric-NO complexes of wild-type
and mutant enzymes.
AB - Fungal nitric-oxide reductase (NOR) is a heme enzyme that catalyzes the reduction
of NO to N(2)O through its ferric-NO complex, the first intermediate of the
catalysis. Crystal structures of the ferric-NO forms of wild type (WT) fungal
NOR, and of the Ser(286) --> Val and Ser(286) --> Thr mutant enzymes were
determined to 1.7-A resolution at cryogenic temperature (100 K). This shows a
slightly tilted and bent NO binding to the heme iron, in sharp contrast to the
highly bent NO coordination found in ferrous hemoproteins. In the WT structure, a
specific hydrogen-bonding network that connects the active site to the solvent
was identified, H(2)O(Wat(74))-Ser(286)-H(2)O(Wat(33))-Asp(393)-solvent. Wat(74)
is located 3.10 A from the iron-bound NO. Replacement of Ser(286) with Val or Thr
scarcely alters the NO coordination structure but expels the water molecules,
Wat(74) from the active site. The Asp(393) mutation does not influence the
position of Wat(74), but disrupts the hydrogen-bonding network at Wat(33), as
evidenced by enzymatic, kinetic, and spectroscopic (resonance Raman and IR)
results. The structural changes observed upon the Ser(286) or the Asp(393)
mutation are consistent with the dramatic loss of the enzymatic activity for the
NO reduction of fungal NOR. We have conclusively identified the water molecule,
Wat(74), adjacent to the iron-bound NO as a proton donor to the Fe-NO moiety. In
addition, we find the hydrogen-bonding network, H(2)O(Wat(74))-Ser(286)
H(2)O(Wat(33))-Asp(393), as a proton delivery pathway in the NO reduction
reaction by fungal NOR.
PMID- 10671517
TI - ERO1-L, a human protein that favors disulfide bond formation in the endoplasmic
reticulum.
AB - Oxidizing conditions must be maintained in the endoplasmic reticulum (ER) to
allow the formation of disulfide bonds in secretory proteins. Here we report the
cloning and characterization of a mammalian gene (ERO1-L) that shares extensive
homology with the Saccharomyces cerevisiae ERO1 gene, required in yeast for
oxidative protein folding. When expressed in mammalian cells, the product of the
human ERO1-L gene co-localizes with ER markers and displays Endo-H-sensitive
glycans. In isolated microsomes, ERO1-L behaves as a type II integral membrane
protein. ERO1-L is able to complement several phenotypic traits of the yeast
thermosensitive mutant ero1-1, including temperature and dithiothreitol
sensitivity, and intrachain disulfide bond formation in carboxypeptidase Y. ERO1
L is no longer functional when either one of the highly conserved Cys-394 or Cys
397 is mutated. These results strongly suggest that ERO1-L is involved in
oxidative ER protein folding in mammalian cells.
PMID- 10671518
TI - A dynactin subunit with a highly conserved cysteine-rich motif interacts directly
with Arp1.
AB - Dynactin is a multisubunit complex and a required cofactor for most, or all, of
the cellular processes powered by the microtubule-based motor cytoplasmic dynein.
Using a dynein affinity column, the previously uncharacterized p62 subunit of
dynactin was isolated and microsequenced. Two peptide sequences were used to
clone human cDNAs encoding p62. Sequence analysis of the predicted human
polypeptide of 53 kDa revealed a highly conserved pattern of eleven cysteine
residues, eight of which fit the consensus sequence for a Zn(2+)-binding RING
domain. We have characterized p62 as an integral component of 20 S dynactin by
biochemical and immunocytochemical methods. Affinity chromatography experiments
demonstrate that p62 binds directly to the Arp1 subunit of dynactin.
Immunocytochemistry with antibodies to p62 demonstrates that this polypeptide has
a punctate cytoplasmic distribution as well as centrosomal distribution typical
of dynactin. In transfected cells, overexpression of p62 did not disrupt
microtubule organization or the integrity of the Golgi but did cause both
cytosolic and nuclear distribution of the protein, suggesting that this
polypeptide may be targeted to the nucleus at very high expression levels.
PMID- 10671519
TI - MAN1, an inner nuclear membrane protein that shares the LEM domain with lamina
associated polypeptide 2 and emerin.
AB - The "MAN antigens" are polypeptides recognized by autoantibodies from a patient
with a collagen vascular disease and localized to the nuclear envelope. We now
show that one of the human MAN antigens termed MAN1 is a 82.3-kDa protein with an
amino-terminal domain followed by two hydrophobic segments and a carboxyl
terminal tail. The MAN1 gene contains seven protein-coding exons and is assigned
to human chromosome 12q14. Its mRNA is approximately 5.5 kilobases and is
detected in several different cell types that were examined. Cell extraction
experiments show that MAN1 is an integral membrane protein. When expressed in
transfected cells, MAN1 is exclusively targeted to the nuclear envelope,
consistent with an inner nuclear membrane localization. Protein sequence analysis
reveals that MAN1 shares a conserved globular domain of approximately 40 amino
acids, which we term the LEM module, with inner nuclear membrane proteins lamina
associated polypeptide 2 and emerin. The LEM module is also present in two
proteins of Caenorhabditis elegans. These results show that MAN1 is an integral
protein of the inner nuclear membrane that shares the LEM module with other
proteins of this subcellular localization.
PMID- 10671520
TI - Molecular cloning of a novel human I-mfa domain-containing protein that
differently regulates human T-cell leukemia virus type I and HIV-1 expression.
AB - Regulation of viral genome expression is the result of complex cooperation
between viral proteins and host cell factors. We report here the characterization
of a novel cellular factor sharing homology with the specific cysteine-rich C
terminal domain of the basic helix-loop-helix repressor protein I-mfa. The
synthesis of this new factor, called HIC for Human I-mfa domain-Containing
protein, is controlled at the translational level by two different codons, an ATG
and an upstream non-ATG translational initiator, allowing the production of two
protein isoforms, p32 and p40, respectively. We show that the HIC protein
isoforms present different subcellular localizations, p32 being mainly
distributed throughout the cytoplasm, whereas p40 is targeted to the nucleolus.
Moreover, in trying to understand the function of HIC, we have found that both
isoforms stimulate in T-cells the expression of a luciferase reporter gene driven
by the human T-cell leukemia virus type I-long terminal repeat in the presence of
the viral transactivator Tax. We demonstrate by mutagenesis that the I-mfa-like
domain of HIC is involved in this regulation. Finally, we also show that HIC is
able to down-regulate the luciferase expression from the human immunodeficiency
virus type 1-long terminal repeat induced by the viral transactivator Tat. From
these results, we propose that HIC and I-mfa represent two members of a new
family of proteins regulating gene expression and characterized by a particular
cysteine-rich C-terminal domain.
PMID- 10671521
TI - Tumor necrosis factor-alpha induces differentiation of and bone resorption by
osteoclasts.
AB - Osteoclast progenitors differentiate into mature osteoclasts in the presence of
receptor activator of NF-kappaB (RANK) ligand on stromal or osteoblastic cells
and monocyte macrophage colony-stimulating factor (M-CSF). The soluble RANK
ligand induces the same differentiation in vitro without stromal cells. Tumor
necrosis factor-alpha (TNF-alpha), a potent cytokine involved in the regulation
of osteoclast activity, promotes bone resorption via a primary effect on
osteoblasts; however, it remains unclear whether TNF-alpha can also directly
induce the differentiation of osteoclast progenitors into mature osteoclasts.
This study revealed that TNF-alpha directly induced the formation of tartrate
resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs), which
produced resorption pits on bone in vitro in the presence of M-CSF. The bone
resorption activity of TNF-alpha-induced MNCs was lower than that of soluble RANK
ligand-induced MNCs; however, interleukin-1beta stimulated this activity of TNF
alpha-induced MNCs without an increase in the number of MNCs. In this case,
interleukin-1beta did not induce TRAP-positive MNC formation. The osteoclast
progenitors expressed TNF receptors, p55 and p75; and the induction of TRAP
positive MNCs by TNF-alpha was inhibited completely by an anti-p55 antibody and
partially by an anti-p75 antibody. Our findings presented here are the first to
indicate that TNF-alpha is a crucial differentiation factor for osteoclasts. Our
results suggest that TNF-alpha and M-CSF play an important role in local
osteolysis in chronic inflammatory diseases.
PMID- 10671522
TI - Carboxypeptidase Z is present in the regulated secretory pathway and
extracellular matrix in cultured cells and in human tissues.
AB - Carboxypeptidase Z (CPZ) is a newly reported member of the
metallocarboxypeptidase gene family, but unlike other members of this family, CPZ
contains an N-terminal domain that has amino acid sequence similarity to Wnt
binding proteins. In order to gain insights as to the potential function of CPZ,
the intracellular localization of this protein was determined in cell culture and
in human tissues. When expressed in the AtT-20 mouse pituitary cell line, CPZ
protein is routed to the regulated secretory pathway and secreted upon
stimulation. A fraction of the secreted CPZ remains associated with the
extracellular matrix. Endogenous CPZ in the PC12 rat pheochromocytoma cell line
is also associated with the extracellular matrix. In human placenta, CPZ is
present within invasive trophoblasts and in the surrounding extracellular space,
indicating an association with extracellular matrix. CPZ is also present in
amnion cells, but is not readily apparent in the extracellular matrix of this
cell type. A human adenocarcinoma of the colon shows expression of CPZ in the
extracellular matrix adjacent to malignant cells. Taken together, CPZ appears to
be a component of the extracellular matrix in some cell types, where it may
function in the binding of Wnt.
PMID- 10671523
TI - The molecular structure of hyperthermostable aromatic aminotransferase with novel
substrate specificity from Pyrococcus horikoshii.
AB - Aromatic amino acid aminotransferase (ArATPh), which has a melting temperature of
120 degrees C, is one of the most thermostable aminotransferases yet to be
discovered. The crystal structure of this aminotransferase from the
hyperthermophilic archaeon Pyrococcus horikoshii was determined to a resolution
of 2.1 A. ArATPh has a homodimer structure in which each subunit is composed of
two domains, in a manner similar to other well characterized aminotransferases.
By the least square fit after superposing on a mesophilic ArAT, the ArATPh
molecule exhibits a large deviation of the main chain coordinates, three
shortened alpha-helices, an elongated loop connecting two domains, and a long
loop transformed from an alpha-helix, which are all factors that are likely to
contribute to its hyperthermostability. The pyridine ring of the cofactor
pyridoxal 5'-phosphate covalently binding to Lys(233) is stacked parallel to F121
on one side and interacts with the geminal dimethyl-CH/pi groups of Val(201) on
the other side. This tight stacking against the pyridine ring probably
contributes to the hyperthermostability of ArATPh. Compared with other ArATs,
ArATPh has a novel substrate specificity, the order of preference being Tyr > Phe
> Glu > Trp > His>> Met > Leu > Asp > Asn. Its relatively weak activity against
Asp is due to lack of an arginine residue corresponding to Arg(292)* (where the
asterisk indicates that this is a residues supplied by the other subunit of the
dimer) in pig cytosolic aspartate aminotransferase. The enzyme recognizes the
aromatic substrate by hydrophobic interaction with aromatic rings (Phe(121) and
Tyr(59)*) and probably recognizes acidic substrates by a hydrophilic interaction
involving a hydrogen bond network with Thr(264)*.
PMID- 10671524
TI - Locking regulatory myosin in the off-state with trifluoperazine.
AB - Scallop striated adductor muscle myosin is a regulatory myosin, its activity
being controlled directly through calcium binding. Here, we show that millimolar
concentrations of trifluoperazine were effective at removal of all regulatory
light chains from scallop myosin or myofibrils. More important, 200 microM
trifluoperazine, a concentration 10-fold less than that required for light-chain
removal, resulted in the reversible elimination of actin-activated and intrinsic
ATPase activities. Unlike desensitization induced by metal ion chelation, which
leads to an elevation of activity in the absence of calcium concurrent with
regulatory light-chain removal, trifluoperazine caused a decline in actin
activated MgATPase activity both in the presence and absence of calcium.
Procedures were equally effective with respect to scallop myosin, myofibrils,
subfragment-1, or desensitized myofibrils. Increased alpha-helicity could be
induced in the isolated essential light chain through addition of 100-200 microM
trifluoperazine. We propose that micromolar concentrations of trifluoperazine
disrupt regulation by binding to a single high-affinity site located in the C
terminal domain of the essential light chain, which locks scallop myosin in a
conformation resembling the off-state. At millimolar trifluoperazine
concentrations, additional binding sites on both light chains would be filled,
leading to regulatory light-chain displacement.
PMID- 10671525
TI - Pairwise interactions between neuronal alpha(7) acetylcholine receptors and alpha
conotoxin PnIB.
AB - This work uses alpha-conotoxin PnIB to probe the agonist binding site of neuronal
alpha(7) acetylcholine receptors. We mutated the 13 non-cysteine residues in CTx
PnIB, expressed alpha(7)/5-hydroxytryptamine-3 homomeric receptors in 293 HEK
cells, and measured binding of each mutant toxin to the expressed receptors by
competition against the initial rate of (125)I-alpha-bungarotoxin binding. The
results reveal that residues Ser-4, Leu-5, Pro-6, Pro-7, Ala-9, and Leu-10 endow
CTx PnIB with affinity for alpha(7)/5-hydroxytryptamine-3 receptors; side chains
of these residues cluster in a localized region within the three-dimensional
structure of CTx PnIB. We next mutated key residues in the seven loops of
alpha(7) that converge at subunit interfaces to form the agonist binding site.
The results reveal predominant contributions by residues Trp-149 and Tyr-93 in
alpha(7) and smaller contributions by Ser-34, Arg-186, Tyr-188, and Tyr-195. To
identify pairwise interactions that stabilize the receptor-conotoxin complex, we
measured binding of receptor and toxin mutations and analyzed the results by
double mutant cycles. The results reveal a single dominant interaction between
Leu-10 of CTx PnIB and Trp-149 of alpha(7) that anchors the toxin to the binding
site. We also find weaker interactions between Pro-6 of CTx PnIB and Trp-149 and
between both Pro-6 and Pro-7 and Tyr-93 of alpha(7). The overall results
demonstrate that a localized hydrophobic region in CTx PnIB interacts with
conserved aromatic residues on one of the two faces of the alpha(7) binding site.
PMID- 10671526
TI - Binding and phosphorylation of a novel male germ cell-specific cGMP-dependent
protein kinase-anchoring protein by cGMP-dependent protein kinase Ialpha.
AB - cGMP-dependent protein kinase (cGK) is a major cellular receptor of cGMP and
plays important roles in cGMP-dependent signal transduction pathways. To isolate
the components of the cGMP/cGK signaling pathway such as substrates and
regulatory proteins of cGK, we employed the yeast two-hybrid system using cGK
Ialpha as a bait and isolated a novel male germ cell-specific 42-kDa protein,
GKAP42 (42-kDa cGMP-dependent protein kinase anchoring protein). Although the N
terminal region (amino acids 1-66) of cGK-Ialpha is sufficient for the
association with GKAP42, GKAP42 could not interact with cGK-Ibeta, cGK-II, or
cAMP-dependent protein kinase. GKAP42 mRNA is specifically expressed in testis,
where it is restricted to the spermatocytes and early round spermatids.
Endogenous cGK-I is co-immunoprecipitated with anti-GKAP42 antibody from mouse
testis tissue, suggesting that cGK-I physiologically interacts with GKAP42.
Immunocytochemical observations revealed that GKAP42 is localized to the Golgi
complex and that cGK-Ialpha is co-localized to the Golgi complex when coexpressed
with GKAP42. Although both cGK-Ialpha and -Ibeta, but not cAMP-dependent protein
kinase, phosphorylated GKAP42 in vitro, GKAP42 was a good substrate only for cGK
Ialpha in intact cells, suggesting that the association with kinase protein is
required for the phosphorylation in vivo. Finally, we demonstrated that the
kinase-deficient mutant of cGK-Ialpha stably associates with GKAP42 and that
binding of cGMP to cGK-Ialpha facilitates their release from GKAP42. These
findings suggest that GKAP42 functions as an anchoring protein for cGK-Ialpha and
that cGK-Ialpha may participate in germ cell development through phosphorylation
of Golgi-associated proteins such as GKAP42.
PMID- 10671527
TI - A eukaryotic alanine racemase gene involved in cyclic peptide biosynthesis.
AB - The cyclic tetrapeptide HC-toxin is an essential virulence determinant for the
plant pathogenic fungus Cochliobolus carbonum and an inhibitor of histone
deacetylase. The major form of HC-toxin contains the D-isomers of Ala and Pro.
The non-ribosomal peptide synthetase that synthesizes HC-toxin has only one
epimerizing domain for conversion of L-Pro to D-Pro; the source of D-Ala has
remained unknown. Here we present the cloning and characterization of a new gene
involved in HC-toxin biosynthesis, TOXG. TOXG is present only in HC-toxin
producing (Tox2(+)) isolates of C. carbonum. TOXG is able to support D-Ala
independent growth of a strain of Escherichia coli defective in D-Ala synthesis.
A C. carbonum strain with both of its copies of TOXG mutated grows normally in
culture, and although it no longer makes the three forms of HC-toxin that contain
D-Ala, it still makes a minor form of HC-toxin that contains Gly in place of D
Ala. The addition of D-Ala to the culture medium restores production of the D-Ala
containing forms of HC-toxin by the toxG mutant. The toxG mutant has only
partially reduced virulence. It is concluded that TOXG encodes an alanine
racemase whose function is to synthesize D-Ala for incorporation into HC-toxin.
PMID- 10671528
TI - Reconciling structure and function in HhaI DNA cytosine-C-5 methyltransferase.
AB - Pre-steady state partitioning analysis of the HhaI DNA methyltransferase directly
demonstrates the catalytic competence of the enzyme.DNA complex and the lack of
catalytic competence of the enzyme.S-adenosyl-L-methionine (AdoMet) complex. The
enzyme.AdoMet complex does form, albeit with a 50-fold decrease in affinity
compared with the ternary enzyme.AdoMet.DNA complex. These findings reconcile the
distinct binding orientations previously observed within the binary enzyme.AdoMet
and ternary enzyme. S-adenosyl-L-homocysteine.DNA crystal structures. The
affinity of the enzyme for DNA is increased 900-fold in the presence of its
cofactor, and the preference for hemimethylated DNA is increased to 12-fold over
unmethylated DNA. We suggest that this preference is partially due to the
energetic cost of retaining a cavity in place of the 5-methyl moiety in the
ternary complex with the unmethylated DNA, as revealed by the corresponding
crystal structures. The hemi- and unmethylated substrates alter the fates and
lifetimes of discrete enzyme.substrate intermediates during the catalytic cycle.
Hemimethylated substrates partition toward product formation versus dissociation
significantly more than unmethylated substrates. The mammalian DNA cytosine-C-5
methyltransferase Dnmt1 shows an even more pronounced partitioning toward product
formation.
PMID- 10671529
TI - Probing the structure of photosystem II with amines and phenylhydrazine.
AB - Photosynthetic oxygen evolution is catalyzed at the manganese-containing active
site of photosystem II (PSII). Amines are analogs of substrate water and
inhibitors of oxygen evolution. Recently, the covalent incorporation of (14)C
from [(14)C]methylamine and benzylamine into PSII subunits has been demonstrated
(Ouellette, A. J. A., Anderson, L. B., and Barry, B. A. (1998) Proc. Natl. Acad.
Sci. U. S. A. 95, 2204-2209). To obtain more information concerning these
labeling reactions, t-[(14)C]butylamine and phenylhydrazine were employed as
probes. Neither compound can be oxidized by a transamination or
addition/elimination mechanism, but both can react with activated carbonyl
groups, produced as a result of posttranslational modification of amino acid
residues, to give amine-derived adducts. (14)C incorporation into the PSII
subunits D2/D1 and CP47 was obtained upon treatment of PSII with either t
[(14)C]butylamine or [(14)C]phenylhydrazine. For t-butylamine and methylamine,
the amount of labeling increased when PSII was treated with denaturing agents.
Labeling of CP47, D2, and D1 with methylamine and phenylhydrazine approached a
one-to-one stoichiometry, assuming that D2 and D1 each have one binding site.
Evidence was obtained suggesting that reductive stabilization and/or access are
modulated by PSII light reactions. These results support the proposal that PSII
subunits D2, D1, and CP47 contain quinocofactors and that access to these sites
is sterically limited.
PMID- 10671530
TI - General anesthetic action at an internal protein site involving the S4-S5
cytoplasmic loop of a neuronal K(+) channel.
AB - The structural bases of general anesthetic action on a neuronal K(+) channel were
investigated using the series of homologous 1-alkanols, electrophysiology, and
mutational analysis. Domain swapping between dShaw2 (alkanol-sensitive) and
hKv3.4 (alkanol-resistant) and site-directed mutagenesis demonstrated that a 13
amino acid cytoplasmic loop (S4-S5) determines the selective inhibition of native
dShaw2 channels by 1-alkanols. The S4-S5 loop may contribute to a receptor for
both 1-alkanols and the inactivation particle, because the enhanced 1-alkanol
sensitivity of hKv3.4 channels hosting S4-S5 mutations correlates directly with
disrupted channel inactivation. Evidence of a discrete protein site was also
obtained from the analysis of the relationship between potency and alkyl chain
length, which begins to level off after 1-hexanol. Rapid application to the
cytoplasmic side of inside-out membrane patches shows that the interaction
between dShaw2 channels and 1-alkanols equilibrates in <200 ms. By contrast, the
equilibration time is >1000-fold slower when the drug is applied externally to
outside-out membrane patches. The data strongly favor a mechanism of inhibition
involving a discrete internal site for 1-alkanols in dShaw2 K(+) channels. A new
working hypothesis proposes that 1-alkanols lock dShaw2 channels in their closed
conformation by a direct interaction at a crevice formed by the S4-S5 loop.
PMID- 10671531
TI - In vitro selection of RNA molecules that inhibit the activity of ricin A-chain.
AB - The cytotoxin ricin disables translation by depurinating a conserved site in
eukaryotic rRNA. In vitro selection has been used to generate RNA ligands
(aptamers) specific for the catalytic ricin A-chain (RTA). The anti-RTA aptamers
bear no resemblance to the normal RTA substrate, the sarcin-ricin loop (SRL), and
were not depurinated by RTA. An initial 80-nucleotide RNA ligand was minimized to
a 31-nucleotide aptamer that contained all sequences and structures necessary for
interacting with RTA. This minimal RNA formed high affinity complexes with RTA
(K(d) = 7.3 nM) which could compete directly with the SRL for binding to RTA. The
aptamer inhibited RTA depurination of the SRL and could partially protect
translation from RTA inhibition. The IC(50) of the aptamer for RTA in an in vitro
translation assay is 100 nM, roughly 3 orders of magnitude lower than a small
molecule inhibitor of ricin, pteroic acid, and 2 orders of magnitude lower than
the best known RNA inhibitor. The novel anti-RTA aptamers may find application as
diagnostic reagents for a potential biological warfare agent and hold promise as
scaffolds for the development of strong ricin inhibitors.
PMID- 10671532
TI - RNA aptamers that bind to and inhibit the ribosome-inactivating protein, pepocin.
AB - Pepocin, isolated from Cucurbita pepo, is a ribosome-inactivating protein (RIP).
RIPs site-specifically recognize and depurinate an adenosine at position 4324 in
rat 28 S rRNA, rendering the ribosome incapable of interacting with essential
elongation factors. Aptamers that target pepocin were isolated from a degenerate
RNA pool by in vitro selection. A conserved hairpin motif, quite different from
the sequence of the toxin-substrate domain in rat 28 S rRNA, was identified in
the aptamer sequences. The aptamers selectively bind to pepocin with dissociation
constants between 20 and 30 nM and inhibit the N-glycosidase activity of pepocin
on rat liver 28 S rRNA. Competitive binding experiments using aptamer variants
suggest that the conserved hairpin region in the anti-pepocin aptamer binds near
the catalytic site on pepocin and prevents the interaction of pepocin and 28 S
rRNA. Anti-RIP aptamers have potential use in diagnostic systems for the
detection of pepocin or could be used as therapy to prevent the action of pepocin
in mammalian cells.
PMID- 10671533
TI - Benzo[a]pyrene induces the transcription of cyclooxygenase-2 in vascular smooth
muscle cells. Evidence for the involvement of extracellular signal-regulated
kinase and NF-kappaB.
AB - Polycyclic aromatic hydrocarbons, such as benzo[a]pyrene (B[a]P) present in
tobacco smoke and tar, have been implicated in the development of atherosclerosis
as well as cancer. Increased expression of cyclooxygenase-2 (COX-2) has been
detected both in atherosclerotic lesions and in epithelial cancers. To determine
whether polycyclic aromatic hydrocarbons might directly affect COX expression in
vascular cells, we investigated the effects of B[a]P on COX-2 expression in human
and rat arterial smooth muscle cells (SMC). Treatment with B[a]P increased levels
of COX-2 protein and mRNA and enhanced prostaglandin synthesis. Nuclear runoff
assays and transient transfections revealed increased COX-2 gene transcription
after treatment with B[a]P. Experiments were done to define the signaling
mechanism by which B[a]P induced COX-2. B[a]P caused a rapid increase in
phosphorylation of extracellular signal-regulated kinase (ERK); pharmacologic
inhibition of mitogen-activated protein kinase kinase blocked B[a]P-mediated
induction of COX-2. Depletion of the intracellular antioxidant, glutathione, with
buthionine sulfoximine significantly increased B[a]P-mediated induction of COX-2
while exposure to N-acetylcysteine, a precursor of glutathione, suppressed the
induction of COX-2 by B[a]P. Several lines of evidence suggest that the induction
of COX-2 by B[a]P is mediated, at least in part, by NF-kappaB. Treatment with
B[a]P increased binding of NF-kappaB to DNA. Moreover, B[a]P-mediated stimulation
of COX-2 promoter activity was blocked when a construct containing a mutagenized
NF-kappaB site was used. Pharmacological inhibitors of NF-kappaB blocked the
induction of COX-2 protein and the stimulation of COX-2 promoter activity by
B[a]P. Taken together, these data are likely to be important for understanding
the atherogenic effects of tobacco smoke.
PMID- 10671534
TI - Distinct repair activities of human 7,8-dihydro-8-oxoguanine DNA glycosylase and
formamidopyrimidine DNA glycosylase for formamidopyrimidine and 7,8-dihydro-8
oxoguanine.
AB - 7,8-dihydro-8-oxoguanine (8-oxoG) and 2,6-diamino-4-hydroxyformamidopyrimidine
(Fapy) are major DNA lesions formed by reactive oxygen species and are involved
in mutagenic and/or lethal events in cells. Both lesions are repaired by human 7,
8-dihydro-8-oxoguanine DNA glycosylase (hOGG1) and formamidopyrimidine DNA
glycosylase (Fpg) in human and Escherichia coli cells, respectively. In the
present study, the repair activities of hOGG1 and Fpg were compared using defined
oligonucleotides containing 8-oxoG and a methylated analog of Fapy (me-Fapy) at
the same site. The k(cat)/K(m) values of hOGG1 for 8-oxoG and me-Fapy were
comparable, and this was also the case for Fpg. However, the k(cat)/K(m) values
of hOGG1 for both lesions were approximately 80-fold lower than those of Fpg.
Analysis of the Schiff base intermediate by NaBH(4) trapping implied that lower
substrate affinity and slower hydrolysis of the intermediate for hOGG1 than Fpg
accounted for the difference. hOGG1 and Fpg showed distinct preferences of the
base opposite 8-oxoG, with the activity differences being 19.8- (hOGG1) and 12
fold (Fpg) between the most and least preferred bases. Surprisingly, such
preferences were almost abolished and less than 2-fold for both enzymes when me
Fapy was a substrate, suggesting that, unlike 8-oxoG, me-Fapy is not subjected to
paired base-dependent repair. The repair efficiency of me-Fapy randomly
incorporated in M13 DNA varied at the sequence level, but orders of preferred and
unpreferred repair sites were quite different for hOGG1 and Fpg. The distinctive
activities of hOGG1 and Fpg including enzymatic parameters (k(cat)/K(m)), paired
base, and sequence context effects may originate from the differences in the
inherent architecture of the DNA binding domain and catalytic mechanism of the
enzymes.
PMID- 10671535
TI - Human peroxisomal multifunctional enzyme type 2. Site-directed mutagenesis
studies show the importance of two protic residues for 2-enoyl-CoA hydratase 2
activity.
AB - Beta-oxidation of acyl-CoAs in mammalian peroxisomes can occur via either
multifunctional enzyme type 1 (MFE-1) or type 2 (MFE-2), both of which catalyze
the hydration of trans-2-enoyl-CoA and the dehydrogenation of 3-hydroxyacyl-CoA,
but with opposite chiral specificity. Amino acid sequence alignment of the 2
enoyl-CoA hydratase 2 domain in human MFE-2 with other MFE-2s reveals conserved
protic residues: Tyr-347, Glu-366, Asp-370, His-406, Glu-408, Tyr-410, Asp-490,
Tyr-505, Asp-510, His-515, Asp-517, and His-532. To investigate their potential
roles in catalysis, each residue was replaced by alanine in site-directed
mutagenesis, and the resulting constructs were tested for complementation in a
yeast. After additional screening, the wild type and noncomplementing E366A and
D510A variants were expressed and characterized. The purified proteins have
similar secondary structural elements, with the same subunit composition. The
E366A variant had a k(cat)/K(m) value 100 times lower than that of the wild type
MFE-2 at pH 5, whereas the D510A variant was inactive. Asp-510 was imbedded in a
novel hydratase 2 motif found in the hydratase 2 proteins. The data show that the
hydratase 2 reaction catalyzed by MFE-2 requires two protic residues, Glu-366 and
Asp-510, suggesting that their catalytic role may be equivalent to that of the
two catalytic residues of hydratase 1.
PMID- 10671536
TI - Cloning, expression, characterization, and nucleophile identification of family
3, Aspergillus niger beta-glucosidase.
AB - The beta-glucosidase from Aspergillus niger (CMI CC 324262) was purified, and an
N-terminal sequence and two internal sequences were determined. BglI genomic gene
and the cDNA were cloned from a genomic library and by reverse transcriptase
polymerase chain reaction, respectively. The cDNA was successfully expressed in
Saccharomyces cerevisiae and Pichia pastoris. Sequence analysis revealed that the
gene encodes a 92-kDa enzyme that is a member of glycosidase family 3. (1)H-NMR
analysis of the reaction catalyzed by this enzyme confirmed that, in common with
other family 3 glycosidases, this enzyme hydrolyzes with net retention of
anomeric configuration. Accordingly, the enzyme was inactivated by 2-deoxy-2
fluoro beta-glucosyl fluoride, with kinetic parameters of k(i) = 4.5 min(-1),
K(I) = 35.4 mM, through the trapping of a covalent glycosyl enzyme intermediate.
The catalytic competence of this intermediate was demonstrated by the fact that
incubation with linamarin resulted in reactivation, presumably via a
transglycosylation mechanism. Peptic digestion of the 2-deoxy-2-fluoroglucosyl
enzyme and subsequent analysis of high pressure liquid chromatography eluates by
electrospray ionization triple quadrupole mass spectrometry in the neutral loss
mode allowed the localization of a 2-deoxy-2-fluoroglucosyl-peptide. Sequence
determination of this labeled peptide by tandem mass spectrometry in the daughter
ion scan mode permitted the identification of Asp-261 as the catalytic
nucleophile within the sequence VMSDW. Asp-261 is fully conserved within this
family, consistent with its key role, and aligns with the aspartic acid residue
previously identified in the Aspergillus wentii enzyme by labeling with
conduritol B epoxide (Bause, E., and Legler, G. (1974) Hoppe-Seyler's Z. Physiol.
Chem. 355, 438-442).
PMID- 10671537
TI - Mannose trimming targets mutant alpha(2)-plasmin inhibitor for degradation by the
proteasome.
AB - We have previously characterized the molecular and cellular mechanisms of
alpha(2)-plasmin inhibitor (alpha(2)PI) deficiency. The mutant alpha(2)PI-Nara
and alpha(2)PI-Okinawa proteins were found to be retained and degraded in cells
stably expressing these mutant forms of alpha(2)PI. Degradation of the two mutant
alpha(2)PI proteins, mediated by proteasomes, occurred after a lag time of 1.5 h
during which glucose trimming took place. The mutant alpha(2)PI proteins were not
ubiquitinated. Inhibition of mannosidase activity blocked the degradation of the
mutant alpha(2)PI proteins without resulting in any changes in their binding to
calnexin. Inhibition of glucose removal completely blocked the interaction
between the alpha(2)PI proteins and the molecular chaperone calnexin. Under these
conditions, mannose residues were removed from the oligosaccharides even when
glucose residues were not processed. With mannose removal, the glucose-untrimmed
mutant forms of alpha(2)PI, which failed to bind to calnexin, were degraded by
proteasomes. The initiation of mannose trimming was a prerequisite for their
degradation. Our findings show that modification of oligosaccharides of the
mutant forms of alpha(2)PI determines their recognition by the degradation
apparatus and that mannose trimming is important for targeting the mutant
alpha(2)PI proteins for the degradation pathway.
PMID- 10671538
TI - Cloning and characterization of the alpha(1,3/4) fucosyltransferase of
Helicobacter pylori.
AB - The gastric pathogen Helicobacter pylori can express the histo blood group
antigens, which are on the surface of many human cells. Most H. pylori strains
express the type II carbohydrates, Lewis X and Y, whereas a small population
express the type I carbohydrates, Lewis A and B. The expression of Lewis A and
Lewis X, as in the case of H. pylori strain UA948, requires the addition of
fucose in alpha1,4 and alpha1,3 linkages to type I or type II carbohydrate
backbones, respectively. This work describes the cloning and characterization of
a single H. pylori fucosyltransferase (FucT) enzyme, which has the ability to
transfer fucose to both of the aforementioned linkages in a manner similar to the
human fucosyltransferase V (Fuc-TV). Two homologous copies of the fucT gene have
been identified in each of the genomes sequenced. The characteristic adenosine
and cytosine tracts in the amino terminus and repeated regions in the carboxyl
terminus are present in the DNA encoding the two UA948fucT genes, but these genes
also contain differences when compared with previously identified H. pylori
fucTs. The UA948fucTa gene encodes an approximately 52-kDa protein containing 475
amino acids, whereas UA948fucTb does not encode a full-length FucT protein. In
vitro, UA948FucTa appears to add fucose with a greater than 5-fold preference for
type II chains but still retains significant activity using type I acceptors. The
addition of the fucose to the type II carbohydrate acceptors, by UA948FucTa, does
not appear to be affected by fucosylation at other sites on the carbohydrate
acceptor, but the rate of fucose transfer is affected by terminal fucosylation of
type I acceptors. Through mutational analysis we demonstrate that only FucTa is
active in this H. pylori isolate and that inactivation of this enzyme eliminates
expression of all Lewis antigens.
PMID- 10671539
TI - A pattern-recognition protein for beta-1,3-glucan. The binding domain and the
cDNA cloning of beta-1,3-glucan recognition protein from the silkworm, Bombyx
mori.
AB - The beta-1,3-glucan recognition protein (betaGRP) has strong specific affinity
for beta-1,3-glucan, a component of the fungal cell wall. Its interaction with
beta-1,3-glucan initiates the activation of the prophenoloxidase cascade, which
is an important defense system in invertebrates of many species. We cloned the
cDNA of the betaGRP of the silkworm Bombyx mori. The betaGRP mRNA transcript was
constitutively expressed in the hemocytes, fat body, and epithelial cells of the
naive silkworm. At the same time, a bacterial or yeast challenge was indicated to
intensify the transcription. Comparison of the deduced amino acid sequence with
known sequences revealed that the betaGRP contained a region (Thr(264) to
Pro(386)) displaying significant similarity to the catalytic regions of bacterial
beta-1,3-glucanases and much higher similarity to the glucanase-like regions of
Gram-negative bacteria-binding proteins found in the silkworm B. mori and the
mosquito Anopheles gambiae. The region (Thr(264) to Pro(386)) of the betaGRP,
however, was demonstrated not to have appreciable affinity for beta-1,3-glucan. A
recombinant peptide corresponding to an N-terminal region (Tyr(1) to Ala(102)) of
the betaGRP bound strongly to beta-1,3-glucan. These results indicate that the
binding domain of the betaGRP for beta-1,3-glucan is located in the N-terminal
region. Glucanases and the current pattern-recognition proteins that contain a
glucanase-like region seem to have a common origin in their molecular evolution.
PMID- 10671540
TI - The regulatory beta subunit of protein kinase CK2 mediates formation of
tetrameric CK2 complexes.
AB - Protein kinase CK2 is a tetrameric enzyme composed of two catalytic (alpha and/or
alpha') subunits and two regulatory (beta) subunits. Because CK2beta is
synthesized in excess of CK2alpha, we hypothesized that formation of CK2beta
homodimers precedes the incorporation of the catalytic subunits of CK2 into
complexes. To test this hypothesis, we cotransfected cells with two epitope
tagged variants of CK2beta. The results of these cotransfection studies
demonstrate that interactions between two CK2beta subunits take place in the
absence of CK2alpha. Together with results from previous biosynthetic labeling
studies, these results suggest that formation of CK2beta homodimers occurs before
incorporation of catalytic subunits of CK2 into CK2 complexes. We also
cotransfected Cos-7 cells with a deletion fragment of CK2beta (i.e. Myc-beta1
166) together with full-length hemagglutinin (HA)-tagged CK2beta and/or
CK2alpha'. Although complexes between Myc-beta1-166 and HA-beta were readily
detected, we obtained no evidence of direct interactions between Myc-beta1-166
and HA-CK2alpha'. These results suggest that residues within the N-terminal 166
amino acids of CK2beta are sufficient for interactions between CK2beta subunits,
whereas the C-terminal domain of CK2beta is required for complex formation with
the catalytic subunits of CK2. Finally, we observed that expression of full
length HA-beta promotes phosphorylation of Myc-beta1-166 by HA-CK2alpha'.
PMID- 10671541
TI - Translocation of hormone-sensitive lipase and perilipin upon lipolytic
stimulation of rat adipocytes.
AB - Adipocyte lipolysis was compared with hormone-sensitive lipase (HSL)/perilipin
subcellular distribution and perilipin phosphorylation using Western blot
analysis. Under basal conditions, HSL resided predominantly in the cytosol and
unphosphorylated perilipin upon the lipid droplet. Upon lipolytic stimulation of
adipocytes isolated from young rats with the beta-adrenergic agonist,
isoproterenol, HSL translocated from the cytosol to the lipid droplet, but there
was no movement of perilipin from the droplet to the cytosol; however, perilipin
phosphorylation was observed. By contrast, upon lipolytic stimulation and
perilipin phosphorylation in cells from more mature rats, there was no HSL
translocation but a significant movement of perilipin away from the lipid
droplet. Adipocytes from younger rats had markedly greater rates of lipolysis
than those from the older rats. Thus high rates of lipolysis require
translocation of HSL to the lipid droplet and translocation of HSL and perilipin
can occur independently of each other. A loss of the ability to translocate HSL
to the lipid droplet probably contributes to the diminished lipolytic response to
catecholamines with age.
PMID- 10671542
TI - Fatty acid and lipoic acid biosynthesis in higher plant mitochondria.
AB - Fatty acid and lipoic acid biosynthesis were investigated in plant mitochondria.
Although the mitochondria lack acetyl-CoA carboxylase, our experiments reveal
that they contain the enzymatic equipment necessary to transform malonate into
the two main building units for fatty acid synthesis: malonyl- and acetyl-acyl
carrier protein (ACP). We demonstrated, by a new method based on a complementary
use of high performance liquid chromatography and mass spectrometry, that the
soluble mitochondrial fatty-acid synthase produces mainly three predominant acyl
ACPs as follows: octanoyl(C8)-, hexadecanoyl(C16)-, and octadecanoyl(C18)-ACP.
Octanoate production is of primary interest since it has been postulated long ago
to be a precursor of lipoic acid. By using a recombinant H apoprotein mutant as a
potential acceptor for newly synthesized lipoic acid, we were able to detect
limited amounts of lipoylated H protein in the presence of malonate, several
sulfur donors, and cofactors. Finally, we present a scheme outlining the new
biochemical pathway of fatty acid and lipoic acid synthesis in plant
mitochondria.
PMID- 10671543
TI - Estrogen stimulates heat shock protein 90 binding to endothelial nitric oxide
synthase in human vascular endothelial cells. Effects on calcium sensitivity and
NO release.
AB - Estradiol (E(2)) causes endothelium-dependent vasodilation, mediated, in part, by
enhanced nitric oxide (NO) release. We have previously shown that E(2)-induced
activation of endothelial nitric oxide synthase (eNOS) reduces its calcium
dependence. This pathway of eNOS activation is unique to a limited number of
stimuli, including shear stress, the response to which is herbimycin-inhibitable.
Consistent with this, herbimycin and geldanamycin pretreatment of human umbilical
vein endothelial cells (HUVEC) abrogated E(2)-stimulated NO release and cGMP
production, respectively. These benzoquinone ansamycins are potent inhibitors of
Hsp90 function, which has recently been shown to play a role in stimulus
dependent eNOS activation. As in response to shear, E(2) induced an Hsp90-eNOS
association, peaking at 30 min and completely inhibited by the conventional
estrogen receptor antagonist ICI 182,780. These findings suggest that Hsp90 plays
an important role in the rapid, estrogen receptor-mediated modulation of eNOS
activation by estrogen.
PMID- 10671544
TI - Apoptotic cleavage of scaffold attachment factor A (SAF-A) by caspase-3 occurs at
a noncanonical cleavage site.
AB - Members of the caspase family of cysteine proteases play essential roles in the
disintegration of cellular architecture during apoptosis. Caspases have been
grouped into subfamilies according to their preferred cleavage sites, with the
"apoptotic executioner" caspase-3 as the prototype of DEXD-dependent proteases.
We show here that caspase-3 is more tolerant to variations of the cleavage site
than previously anticipated and present an example of a noncanonical recognition
site that is efficiently cleaved by caspase-3 in vitro and in vivo. The new
cleavage site was identified in human scaffold attachment factor A, one of the
major scaffold attachment region DNA-binding proteins of human cells thought to
be involved in nuclear architecture by fastening chromatin loops to a
proteinaceous nuclear skeleton, the so-called nuclear matrix or scaffold. Using
an amino-terminal recombinant construct of scaffold attachment factor A and
recombinant caspase-3, we have mapped the cleavage site by matrix-assisted laser
desorption ionization/time of flight mass spectrometry and Edman sequencing. We
find that cleavage occurs after Asp-100 in a sequence context (SALD) that does
not conform to the hitherto accepted DEXD consensus sequence of caspase-3. A
point mutation, D100A, abrogates cleavage by recombinant caspase-3 in vitro and
during apoptosis in vivo, confirming SALD as a novel caspase-3 cleavage site.
PMID- 10671545
TI - Parathyroid hormone regulation of the rat collagenase-3 promoter by protein
kinase A-dependent transactivation of core binding factor alpha1.
AB - Previously we showed that the activator protein-1 site and the runt domain
binding site in the collagenase-3 promoter act cooperatively in response to
parathyroid hormone (PTH) in the rat osteoblastic osteosarcoma cell line, UMR 106
01. Our results of the expression pattern of core binding factor alpha1 (Cbfa1),
which binds to the runt domain site, indicated that there is no change in the
levels of Cbfa1 protein or RNA under either control conditions or after PTH
treatment. The importance of posttranslational modification of Cbfa1 in the
signaling pathway for PTH-induced collagenase-3 promoter activity was analyzed.
PTH stimulation of collagenase-3 promoter activity was completely abrogated by
protein kinase A (PKA) inhibition. To determine the role of PKA activity with
respect to Cbfa1 activation (in addition to its known activity of phosphorylating
cAMP-response element-binding protein to enhance c-fos promoter activity), we
utilized the heterologous Gal4 transcription system. PTH stimulated the
transactivation of activation domain-3 in Cbfa1 through the PKA site. In vitro
phosphorylation studies indicated that the PKA site in the wild type activation
domain-3 is a substrate for phosphorylation by PKA. Thus, we demonstrate that PTH
induces a PKA-dependent transactivation of Cbfa1, and this transactivation is
required for collagenase-3 promoter activity in UMR cells.
PMID- 10671546
TI - Distinct central amphipathic alpha-helices in apolipoprotein A-I contribute to
the in vivo maturation of high density lipoprotein by either activating lecithin
cholesterol acyltransferase or binding lipids.
AB - Recombinant adenoviruses with cDNAs for human apolipoprotein A-I (wild type (wt)
apoA-I) and three mutants, referred to as Delta4-5A-I, Delta5-6A-I, and Delta6-7A
I, that have deletions removing regions coding for amino acids 100-143, 122-165,
and 144-186, respectively, were created to study structure/function relationships
of apoA-I in vivo. All mutants were expressed at lower concentrations than wt
apoA-I in plasma of fasting apoA-I-deficient mice. The Delta5-6A-I mutant was
found primarily in the lipid-poor high density lipoprotein (HDL) pool and at
lower concentrations than Delta4-5A-I and Delta6-7A-I that formed more buoyant
HDL(2/3) particles. At an elevated adenovirus dose and earlier blood sampling
from fed mice, both Delta5-6A-I and Delta6-7A-I increased HDL-free cholesterol
and phospholipid but not cholesteryl ester. In contrast, wt apoA-I and Delta4-5A
I produced significant increases in HDL cholesteryl ester. Further analysis
showed that Delta6-7A-I and native apoA-I could bind similar amounts of
phospholipid and cholesterol that were reduced slightly for Delta5-6A-I and
greatly for Delta4-5A-I. We conclude from these findings that amino acids (aa)
100-143, specifically helix 4 (aa 100-121), contributes to the maturation of HDL
through a role in lipid binding and that the downstream sequence (aa 144-186)
centered around helix 6 (aa 144-165) is responsible for the activation of
lecithin-cholesterol acyltransferase.
PMID- 10671547
TI - Removal of a putative inhibitory element reduces the calcium-dependent calmodulin
activation of neuronal nitric-oxide synthase.
AB - Neuronal nitric-oxide synthase (NOS) and endothelial NOS are constitutive NOS
isoforms that are activated by binding calmodulin in response to elevated
intracellular calcium. In contrast, the inducible NOS isoform binds calmodulin at
low basal levels of calcium in resting cells. Primary sequence comparisons show
that each constitutive NOS isozyme contains a polypeptide segment within its
reductase domain, which is absent in the inducible NOS enzyme. To study a
possible link between the presence of these additional polypeptide segments in
constitutive NOS enzymes and their calcium-dependent calmodulin activation, three
deletion mutants were created. The putative inhibitory insert was removed from
the FMN binding regions of the neuronal NOS holoenzyme and from two truncated
neuronal NOS reductase enzymes in which the calmodulin binding region was either
included or deleted. All three mutant enzymes showed reduced incorporation of FMN
and required reconstitution with exogenous FMN for activity. The combined removal
of both the calmodulin binding domain and the putative inhibitory insert did not
result in a calmodulin-independent neuronal NOS reductase. Thus, although the
putative inhibitory element has an effect on the calcium-dependent calmodulin
activation of neuronal NOS, it does not have the properties of the typical
autoinhibitory domain found in calmodulin-activated enzymes.
PMID- 10671548
TI - Class- and splice variant-specific association of CD98 with integrin beta
cytoplasmic domains.
AB - CD98 is a type II transmembrane protein involved in neutral and basic amino acid
transport and in cell fusion events. CD98 was implicated in the function of
integrin adhesion receptors by its capacity to reverse suppression of integrin
activation by isolated integrin beta(1A) domains. Here we report that CD98
associates with integrin beta cytoplasmic domains with a unique integrin class
and splice variant specificity. In particular, CD98 interacted with the
ubiquitous beta(1A) but not the muscle-specific splice variant, beta(1D), or
leukocyte-specific beta(7) cytoplasmic domains. The ability of CD98 to associate
with integrin cytoplasmic domains correlated with its capacity to reverse
suppression of integrin activation. The association of CD98 with integrin
beta(1A) cytoplasmic domains may regulate the function and localization of these
membrane proteins.
PMID- 10671549
TI - Cu,Zn-superoxide dismutase-dependent apoptosis induced by nitric oxide in
neuronal cells.
AB - Nitric oxide (NO) challenge to human neuroblastoma cells (SH-SY5Y) ultimately
results in apoptosis. Tumor suppressor protein p53 and cell cycle inhibitor p21
accumulate as an early sign of S-nitrosoglutathione-mediated toxicity. Cytochrome
c release from mitochondria and caspase 3 activation also occurred. Cells
transfected with either wild type (WT) or mutant (G93A) Cu, Zn-superoxide
dismutase (Cu,Zn-SOD) produced comparable amounts of nitrite/nitrate but showed
different degree of apoptosis. G93A cells were the most affected and WT cells the
most protected; however, Cu, Zn-SOD content of these two cell lines was 2-fold
the SH-SY5Y cells under both resting and treated conditions. We linked decreased
susceptibility of the WT cells to higher and more stable Bcl-2 and decreased
reactive oxygen species. Conversely, we linked G93A susceptibility to increased
reactive oxygen species production since simultaneous administration of S
nitrosoglutathione and copper chelators protects from apoptosis. Furthermore,
G93A cells showed a significant decrease of Bcl-2 expression and, as target of NO
derived radicals, showed lower cytochrome c oxidase activity. These results
demonstrate that resistance to NO-mediated apoptosis is strictly related to the
level and integrity of Cu,Zn-SOD and that the balance between reactive nitrogen
and reactive oxygen species regulates neuroblastoma apoptosis.
PMID- 10671550
TI - The differentially conserved residues of carbamoyl-phosphate synthetase.
AB - Carbamoyl-phosphate synthetase (CPS) from Escherichia coli is a heterodimeric
protein. The larger of the two subunits (M(r) approximately 118,000) contains a
pair of homologous domains of approximately 400 residues each that are
approximately 40% identical in amino acid sequence. The carboxy phosphate
(residues 1-400) and carbamoyl phosphate domains (residues 553-933) also contain
approximately 79 differentially conserved residues. These are residues that are
conserved throughout the bacterial evolution of CPS in one of these homologous
domains but not the other. The role of these differentially conserved residues in
the structural and catalytic properties of CPS was addressed by swapping segments
of these residues from one domain to the other. Nine of these chimeric mutant
enzymes were constructed, expressed, purified, and characterized. A majority of
the mutants were unable to synthesize any carbamoyl phosphate and the rest were
severely crippled. True tandem repeat chimeric proteins were constructed by the
complete substitution of one homologous domain sequence for the other. Neither of
the two possible chimeric proteins was structurally stable. These results have
been interpreted to demonstrate that the two homologous domains in the large
subunit of CPS are functionally and structurally nonequivalent. This
nonequivalence is a direct result of the specific functions each of these domains
must perform during the overall synthesis of carbamoyl phosphate in the wild type
enzyme and the specific structural alterations imposed by the differentially
conserved residues.
PMID- 10671551
TI - The thioredoxin system of Helicobacter pylori.
AB - This paper describes the purification of thioredoxin reductase (TR) and the
characterization, purification, and cloning of thioredoxin (Trx) from
Helicobacter pylori. Purification, amino acid sequence analysis, and molecular
cloning of the gene encoding thioredoxin revealed that it is a 12-kDa protein
which possesses the conserved redox active motif CGPC. The gene encoding Trx was
amplified by polymerase chain reaction and inserted into a pET expression vector
and used to transform Escherichia coli. Trx was overexpressed by induction with
isopropyl-1-thio-beta-D-galactopyranoside as a decahistidine fusion protein and
was recovered from the cytoplasm as a soluble and active protein. The redox
activity of this protein was characterized using several mammalian proteins of
different architecture but all containing disulfide bonds. H. pylori thioredoxin
efficiently reduced insulin, human immunoglobulins (IgG/IgA/sIgA), and soluble
mucin. Subcellular fractionation analysis of H. pylori revealed that thioredoxin
was associated largely with the cytoplasm and inner membrane fractions of the
cell in addition to being recovered in the phosphate-buffered saline-soluble
fraction of freshly harvested cells. H. pylori TR was purified to homogeneity by
chromatography on DEAE-52, Cibacron blue 3GA, and 2',5'-ADP-agarose. Gel
filtration revealed that the native TR had a molecular mass of 70 kDa which
represented a homodimer composed of two 35-kDa subunits, as determined by SDS
polyacrylamide gel electrophoresis. H. pylori TR (NADPH-dependent) efficiently
catalyzed the reduction of 5,5'-dithiobis(nitrobenzoic acid) in the presence of
either native or recombinant H. pylori Trx. H. pylori Trx behaved also as a
stress response element as broth grown bacteria secreted Trx in response to
chemical, biological, and environmental stresses. These observations suggest that
Trx may conceivably assist H. pylori in the process of colonization by inducing
focal disruption of the oligomeric structure of mucin while rendering host
antibody inactive through catalytic reduction.
PMID- 10671552
TI - Casein kinase II phosphorylation of E-cadherin increases E-cadherin/beta-catenin
interaction and strengthens cell-cell adhesion.
AB - Beta-catenin, a member of the Armadillo repeat protein family, binds directly to
the cytoplasmic domain of E-cadherin, linking it via alpha-catenin to the actin
cytoskeleton. A 30-amino acid region within the cytoplasmic domain of E-cadherin,
conserved among all classical cadherins, has been shown to be essential for beta
catenin binding. This region harbors several putative casein kinase II (CKII) and
glycogen synthase kinase-3beta (GSK-3beta) phosphorylation sites and is highly
phosphorylated. Here we report that in vitro this region is indeed phosphorylated
by CKII and GSK-3beta, which results in an increased binding of beta-catenin to E
cadherin. Additionally, in mouse NIH3T3 fibroblasts expression of E-cadherin with
mutations in putative CKII sites resulted in reduced cell-cell contacts. Thus,
phosphorylation of the E-cadherin cytoplasmic domain by CKII and GSK-3beta
appears to modulate the affinity between beta-catenin and E-cadherin, ultimately
modifying the strength of cell-cell adhesion.
PMID- 10671553
TI - Utilization of distinct signaling pathways by receptors for vascular endothelial
cell growth factor and other mitogens in the induction of endothelial cell
proliferation.
AB - This study was initiated to identify signaling proteins used by the receptors for
vascular endothelial cell growth factor KDR/Flk1, and Flt1. Two-hybrid cloning
and immunoprecipitation from human umbilical vein endothelial cells (HUVEC)
showed that KDR binds to and promotes the tyrosine phosphorylation of
phospholipase Cgamma (PLCgamma). Neither placental growth factor, which activates
Flt1, epidermal growth factor (EGF), or fibroblast growth factor (FGF) induced
tyrosine phosphorylation of PLCgamma, indicating that KDR is uniquely important
to PLCgamma activation in HUVEC. By signaling through KDR, VEGF promoted the
tyrosine phosphorylation of focal adhesion kinase, induced activation of Akt,
protein kinase Cepsilon (PKCepsilon), mitogen-activated protein kinase (MAPK),
and promoted thymidine incorporation into DNA. VEGF activates PLCgamma,
PKCepsilon, and phosphatidylinositol 3-kinase independently of one another. MEK,
PLCgamma, and to a lesser extent PKC, are in the pathway through which KDR
activates MAPK. PLCgamma or PKC inhibitors did not affect FGF- or EGF-mediated
MAPK activation. MAPK/ERK kinase inhibition diminished VEGF-, FGF-, and EGF
promoted thymidine incorporation into DNA. However, blockade of PKC diminished
thymidine incorporation into DNA induced by VEGF but not FGF or EGF. Signaling
through KDR/Flk1 activates signaling pathways not utilized by other mitogens to
induce proliferation of HUVEC.
PMID- 10671554
TI - Cloning and expression of glycolipid transfer protein from bovine and porcine
brain.
AB - Glycolipid transfer protein (GLTP) is a small (23-24 kDa), basic protein (pI
congruent with 9.0) that accelerates the intermembrane transfer of various
glycolipids. Here, we report the first cloning of cDNAs that encode the bovine
and porcine GLTPs. The cDNA open reading frame for bovine GLTP was constructed by
bridge-overlapping extension polymerase chain reaction (PCR) after obtaining
partial coding cDNA clones by hot start, seminested, and rapid amplification of
cDNA ends-PCR. The cDNA open reading frame for porcine GLTP was constructed by
reverse transcriptase-PCR. The encoded amino acid sequences in the full-length
bovine and porcine cDNAs were identical, consisting of 209 amino acid residues,
and were nearly the same as the published sequence determined by Edman
degradation. The cDNA encoded one additional amino acid at the N terminus
(methionine), arginine at positions 10 and 200 instead of lysine, and threonine
at position 65 instead of alanine. Expression of GLTP-cDNA in Escherichia coli
using pGEX-6P-1 vector resulted in glutathione S-transferase (GST)-GLTP fusion
protein. Regulation of growth and induction conditions led to approximately 50%
of expressed fusion protein being soluble and active. Proteolytic cleavage of GST
GLTP fusion protein (bound to GST-Sepharose) and affinity purification resulted
in fully active GLTP. Northern blot analyses of bovine tissues showed a single
transcript of approximately 2.2 kilobases and the following hierarchy of mRNA
levels: cerebrum > kidney > spleen congruent with lung congruent with cerebellum
> liver > heart muscle. Reverse transcriptase-PCR analyses of mRNA levels
supported the Northern blot results.
PMID- 10671555
TI - E5 oncoprotein mutants activate phosphoinositide 3-kinase independently of
platelet-derived growth factor receptor activation.
AB - The E5 oncoprotein of bovine papillomavirus type 1 is a Golgi-resident, 44-amino
acid polypeptide that can transform fibroblast cell lines by activating
endogenous platelet-derived growth factor receptor beta (PDGF-R). However, the
recent discovery of E5 mutants that exhibit strong transforming activity but
minimal PDGF-R tyrosine phosphorylation indicates that E5 can potentially use
additional signal transduction pathway(s) to transform cells. We now show that
two classes of E5 mutants, despite poorly activating the PDGF-R, induce tyrosine
phosphorylation and activation of phosphoinositide 3-kinase (PI 3-K) and that
this activation is resistant to a selective inhibitor of PDGF-R kinase activity,
tyrphostin AG1296. Consistent with this independence from PDGF-R signaling, the
E5 mutants fail to induce significant cell proliferation in the absence of PDGF,
unlike wild-type E5 or the sis oncoprotein. Despite differences in growth factor
requirements, however, both wild-type E5 and mutant E5 cell lines form colonies
in agarose. Interestingly, activation of PI 3-K occurs without concomitant
activation of the ras-dependent mitogen-activated protein kinase pathway. The
known ability of constitutively activated PI 3-K to induce anchorage-independent
cell proliferation suggests a mechanism by which the mutant E5 proteins transform
cells.
PMID- 10671556
TI - Catalytic sites for 3' and 5' incision of Escherichia coli nucleotide excision
repair are both located in UvrC.
AB - Nucleotide excision repair in Escherichia coli is a multistep process in which
DNA damage is removed by incision of the DNA on both sides of the damage,
followed by removal of the oligonucleotide containing the lesion. The two
incision reactions take place in a complex of damaged DNA with UvrB and UvrC. It
has been shown (Lin, J. -J., and Sancar, A. (1992) J. Biol. Chem. 267, 17688
17692) that the catalytic site for incision on the 5' side of the damage is
located in the UvrC protein. Here we show that the catalytic site for incision on
the 3' side is in this protein as well, because substitution R42A abolishes 3'
incision, whereas formation of the UvrBC-DNA complex and the 5' incision reaction
are unaffected. Arg(42) is part of a region that is homologous to the catalytic
domain of the homing endonuclease I-TevI. We propose that the UvrC protein
consists of two functional parts, with the N-terminal half for the 3' incision
reaction and the C-terminal half containing all the determinants for the 5'
incision reaction.
PMID- 10671557
TI - The role of disulfide-linked dimerization in interleukin-3 receptor signaling and
biological activity.
AB - Cysteine residues 86 and 91 of the beta subunit of the human interleukin (hIL)-3
receptor (hbetac) participate in disulfide-linked receptor subunit
heterodimerization. This linkage is essential for receptor tyrosine
phosphorylation, since the Cys-86 --> Ala (Mc4) and Cys-91 --> Ala (Mc5)
mutations abolished both events. Here, we used these mutants to examine whether
disulfide-linked receptor dimerization affects the biological and biochemical
activities of the IL-3 receptor. Murine T cells expressing hIL-3Ralpha and Mc4 or
Mc5 did not proliferate in hIL-3, whereas cells expressing wild-type hbetac
exhibited rapid proliferation. However, a small subpopulation of cells expressing
each mutant could be selected for growth in IL-3, and these proliferated
similarly to cells expressing wild-type hbetac, despite failing to undergo IL-3
stimulated hbetac tyrosine phosphorylation. The Mc4 and Mc5 mutations
substantially reduced, but did not abrogate, IL-3-mediated anti-apoptotic
activity in the unselected populations. Moreover, the mutations abolished IL-3
induced JAK2, STAT, and AKT activation in the unselected cells, whereas
activation of these molecules in IL-3-selected cells was normal. In contrast, Mc4
and Mc5 showed a limited effect on activation of Erk1 and -2 in unselected cells.
These data suggest that whereas disulfide-mediated cross-linking and hbetac
tyrosine phosphorylation are normally important for receptor activation,
alternative mechanisms can bypass these requirements.
PMID- 10671558
TI - Direct cleavage by the calcium-activated protease calpain can lead to
inactivation of caspases.
AB - Caspases, a unique family of cysteine proteases involved in cytokine activation
and in the execution of apoptosis can be sub-grouped according to the length of
their prodomain. Long prodomain caspases such as caspase-8 and caspase-9 are
believed to act mainly as upstream caspases to cleave downstream short prodomain
caspases such as caspases-3 and -7. We report here the identification of caspases
as direct substrates of calcium-activated proteases, calpains. Calpains cleave
caspase-7 at sites distinct from those of the upstream caspases, generating
proteolytically inactive fragments. Caspase-8 and caspase-9 can also be directly
cleaved by calpains. Two calpain cleavage sites in caspase-9 have been identified
by N-terminal sequencing of the cleaved products. Cleavage of caspase-9 by
calpain generates truncated caspase-9 that is unable to activate caspase-3 in
cell lysates. Furthermore, direct cleavage of caspase-9 by calpain blocks dATP
and cytochrome-c induced caspase-3 activation. Therefore our results suggest that
calpains may act as negative regulators of caspase processing and apoptosis by
effectively inactivating upstream caspases.
PMID- 10671559
TI - Cholesterol depletion of enterocytes. Effect on the Golgi complex and apical
membrane trafficking.
AB - Intestinal brush border enzymes, including aminopeptidase N and sucrase
isomaltase, are associated with "rafts" (membrane microdomains rich in
cholesterol and sphingoglycolipids). To assess the functional role of rafts in
the present work, we studied the effect of cholesterol depletion on apical
membrane trafficking in enterocytes. Cultured mucosal explants of pig small
intestine were treated for 2 h with the cholesterol sequestering agent methyl
beta-cyclodextrin and lovastatin, an inhibitor of hydroxymethylglutaryl-coenzyme
A reductase. The treatment reduced the cholesterol content >50%. Morphologically,
the Golgi complex/trans-Golgi network was partially transformed into numerous 100
200 nm vesicles. By immunogold electron microscopy, aminopeptidase N was
localized in these Golgi-derived vesicles as well as at the basolateral cell
surface, indicating a partial missorting. Biochemically, the rates of the Golgi
associated complex glycosylation and association with rafts of newly synthesized
aminopeptidase N were reduced, and less of the enzyme had reached the brush
border membrane after 2 h of labeling. In contrast, the basolateral Na(+)/K(+)
ATPase was neither missorted nor raft-associated. Our results implicate the Golgi
complex/trans-Golgi network in raft formation and suggest a close relationship
between this event and apical membrane trafficking.
PMID- 10671560
TI - Functional association between SLAP-130 and SLP-76 in Jurkat T cells.
AB - T cell antigen receptor (TCR) engagement results in protein-tyrosine kinase
activation which initiates signaling cascades leading to induction of the
interleukin-2 gene. Previous studies identified two substrates of the TCR-induced
protein-tyrosine kinases, SH2 domain-containing leukocyte specific protein of 76
kDa (SLP-76) and SLP-76-associated phosphoprotein of 130 kDa (SLAP-130). While
SLP-76 appears to couple the TCR with downstream signals, SLAP-130 may play a
negative regulatory role in T cell activation. In this study, we demonstrate that
consistent with its ability to abrogate the SLP-76 augmentation of TCR-induced
activation of the NFAT/AP1 region of the interleukin-2 promoter, overexpression
of SLAP-130 also interferes with the rescue of signaling in SLP-76-deficient
Jurkat cells in co-transfection experiments. The effect of SLAP-130 on SLP-76
function is specific for regulating TCR-induced ERK activation, but not
phospholipase Cgamma 1 phosphorylation. By generating both deletion and point
mutants of SLAP-130, we identified tyrosine 559 as critical for the interaction
between SLP-76 and SLAP-130. We show that mutation of this residue in context of
full-length SLAP-130 diminishes the ability of SLAP-130 to abrogate SLP-76
function. These data suggest that the SLAP-130/SLP-76 association is important
for the negative regulatory role that SLAP-130 appears to play in T cell
signaling.
PMID- 10671561
TI - Structure and activity associated with multiple forms of Schizosaccharomyces
pombe DNA polymerase delta.
AB - DNA polymerase delta (Pol delta) isolated from Schizosaccharomyces pombe (sp)
consists of at least four subunits, Pol3, Cdc1, Cdc27, and Cdm1. We have
reconstituted the four-subunit complex by simultaneously expressing these
polypeptides in baculovirus-infected insect cells. The properties of the purified
cloned spPol delta were identical to the native spPol delta isolated from S.
pombe cells. In addition, we also isolated a three-subunit complex containing
Pol3, Cdc1, and Cdm1. Both three- and four-subunit complexes required replication
factor C and proliferating cell nuclear antigen for DNA replication. However, in
the presence of low levels of polymerase complexes, the three-subunit complex was
less efficient than the four-subunit complex in supporting DNA replication. The
inefficient synthesis of DNA by the three-subunit complex can be remedied by the
addition of Cdc27, the subunit missing in the three-subunit complex. Gel
filtration analysis demonstrated that the three-subunit complex is a monomer of
the heterotrimer (Pol3, Cdc1, and Cdm1) and that the four-subunit complex is a
dimer of the heterotetramer (Pol3, Cdc1, Cdc27, and Cdm1), similar to the
structure of native spPol delta. We have further shown that Cdc1 and Cdc27
interact to form a heterodimeric complex. Gel filtration studies indicate that
the structure of this complex is dimeric. These observations suggest that the
Cdc27 subunit may play an important role contributing to the dimerization of Pol
delta.
PMID- 10671562
TI - Effects of jasplakinolide on the kinetics of actin polymerization. An explanation
for certain in vivo observations.
AB - Jasplakinolide paradoxically stabilizes actin filaments in vitro, but in vivo it
can disrupt actin filaments and induce polymerization of monomeric actin into
amorphous masses. A detailed analysis of the effects of jasplakinolide on the
kinetics of actin polymerization suggests a resolution to this paradox.
Jasplakinolide markedly enhances the rate of actin filament nucleation. This
increase corresponds to a change in the size of actin oligomer capable of
nucleating filament growth from four to approximately three subunits, which is
mechanistically consistent with the localization of the jasplakinolide-binding
site at an interface of three actin subunits. Because jasplakinolide both
decreases the amount of sequestered actin (by lowering the critical concentration
of actin) and augments nucleation, the enhancement of polymerization by
jasplakinolide is amplified in the presence of actin-monomer sequestering
proteins such as thymosin beta(4). Overall, the kinetic parameters in vitro
define the mechanism by which jasplakinolide induces polymerization of monomeric
actin in vivo. Expected consequences of jasplakinolide function are consistent
with the experimental observations and include de novo nucleation resulting in
disordered polymeric actin and in insufficient monomeric actin to allow for
remodeling of stress fibers.
PMID- 10671563
TI - Two heme-binding domains of heme-regulated eukaryotic initiation factor-2alpha
kinase. N terminus and kinase insertion.
AB - In heme deficiency, protein synthesis in reticulocytes is inhibited by activation
of heme-regulated alpha-subunit of eukaryotic initiation factor-2alpha (eIF
2alpha) kinase (HRI). Previous studies indicate that HRI contains two distinct
heme-binding sites per HRI monomer. To study the role of the N terminus in the
heme regulation of HRI, two N-terminally truncated mutants, Met2 and Met3
(deletion of the first 103 and 130 amino acids, respectively), were prepared.
Met2 and Met3 underwent autophosphorylation and phosphorylated eIF-2alpha with a
specific activity of approximately 50% of that of the wild type HRI. These
mutants were significantly less sensitive to heme regulation both in vivo and in
vitro. In addition, the heme contents of purified Met2 and Met3 HRI were less
than 5% of that of the wild type HRI. These results indicated that the N terminus
was important but was not the only domain involved in the heme-binding and heme
regulation of HRI. Heme binding of the individual HRI domains showed that both N
terminus and kinase insertion were able to bind hemin, whereas the C terminus and
the catalytic domains were not. Thus, both the N terminus and the kinase
insertion, which are unique to HRI, are involved in the heme binding and the heme
regulation of HRI.
PMID- 10671564
TI - Endothelial nitric-oxide synthase (type III) is activated and becomes calcium
independent upon phosphorylation by cyclic nucleotide-dependent protein kinases.
AB - Endothelial nitric-oxide synthase (NOS-III) is defined as being strictly
dependent on Ca(2+)/calmodulin (CaM) for activity, although NO release from
endothelial cells has been reported to also occur at intracellular free Ca(2+)
levels that are substimulatory for the purified enzyme. We demonstrate here that
NOS-III, but neither NOS-I nor -II, is rapidly and strongly activated and
phosphorylated on both Ser and Thr in the presence of cGMP-dependent protein
kinase II (cGK II) and the catalytic subunit of cAMP-dependent protein kinase
(cAK) in vitro. Phosphopeptide analysis by mass spectrometry identified
Ser(1177), as well as Ser(633) which is situated in a recently defined CaM
autoinhibitory domain within the flavin-binding region of human NOS-III.
Phosphoamino acid analysis identified a putative phosphorylation site at Thr(495)
in the CaM-binding domain. Importantly, both cAK and cGK phosphorylation of NOS
III in vitro caused a highly reproducible partial (10-20%) NOS-III activation
which was independent of Ca(2+)/CaM, and as much as a 4-fold increase in V(max)
in the presence of Ca(2+)/CaM. cAK stimulation in intact endothelial cells also
increased both Ca(2+/)CaM-independent and -dependent activation of NOS-III. These
data collectively provide new evidence for cAK and cGK stimulation of both
Ca(2+)/CaM-independent and -dependent NOS-III activity, and suggest possible
cross-talk between the NO and prostaglandin I(2) pathways and a positive feedback
mechanism for NO/cGMP signaling.
PMID- 10671565
TI - Alternative splicing of GAD67 results in the synthesis of a third form of
glutamic-acid decarboxylase in human islets and other non-neural tissues.
AB - Two forms of glutamic-acid decarboxylase (GAD) have been identified in mammalian
tissues: a 65-kDa form (GAD65) and a 67-kDa form (GAD67). Alternate splicing
produces one or two smaller variants of GAD67 in the brain of embryonic mice and
rats. Additionally, a short, heretofore unidentified transcript homologous to
GAD67 has been detected in human testis RNA. Because GAD, the enzyme responsible
for gamma-aminobutyric acid production and a key autoantigen in type I diabetes,
has unclear function in non-neural tissue, it is important to understand its
pattern of expression. Unlike GAD65, GAD67 is not produced in human pancreatic
islets. Here, we describe a novel splice variant of GAD67 that is produced in
human islets, testis, adrenal cortex, and perhaps other endocrine tissues, but
not in brain. This transcript directs the synthesis of a protein without GAD
enzymatic activity: GAD25. A unique peptide sequence at the carboxyl terminus of
GAD25 is highly conserved between mice, rats, and humans. We conclude that humans
produce a third form of GAD in non-neural tissues and that human islets, although
they do not synthesize full-length GAD67, do express this shortened variant.
PMID- 10671566
TI - LeSBT1, a subtilase from tomato plants. Overexpression in insect cells,
purification, and characterization.
AB - The cDNA of a tomato subtilase designated LeSBT1 was cloned from a tomato flower
cDNA library. The deduced amino acid sequence indicated for LeSBT1 the structure
of a prepro-protein targeted to the secretory pathway by virtue of an amino
terminal signal peptide. LeSBT1 was expressed in the baculovirus/insect cell
system and a processed 73-kDa form of LeSBT1, lacking both signal peptide and
prodomain, was purified to homogeneity from culture supernatants. This 73-kDa
LeSBT1, however, lacked proteolytic activity. Zymogen activation to yield 68-kDa
LeSBT1 required the additional processing of an amino-terminal autoinhibitory
peptide in a strictly pH-dependent manner. Mature 68-kDa LeSBT1 showed highest
activity at acidic pH consistent with its presumed localization in the apoplast
of the plant cell. In comparison to other plant subtilases, LeSBT1 exhibited a
narrower substrate specificity in that it cleaves only polypeptide substrates
preferentially but not exclusively carboxyl-terminal of glutamine residues. The
possible involvement of LeSBT1 in selective proprotein processing is discussed
with reference to the related mammalian proprotein convertases.
PMID- 10671567
TI - Glucose regulation of mouse S(14) gene expression in hepatocytes. Involvement of
a novel transcription factor complex.
AB - Transcription of genes encoding enzymes required for lipogenesis is induced in
hepatocytes in response to elevated glucose metabolism. We have previously mapped
the carbohydrate-response elements (ChoREs) of the rat liver-type pyruvate kinase
(L-PK) and S(14) genes and found them to share significant sequence similarity.
However, progress in unraveling this signaling pathway has been hampered due to
the difficulty in identifying the key factor(s) that bind to these ChoREs. To
gain further insight into the nature of the carbohydrate-responsive transcription
factor, the glucose regulatory sequences from the mouse S(14) gene were examined
in primary hepatocytes. Three elements were found to be essential for supporting
the glucose response: a thyroid hormone-response element between -1522 and -1494,
an accessory factor site between -1421 and -1392, and the ChoRE between -1450 and
-1425. Of these, only the accessory factor site was conserved between the rat and
mouse S(14) genes. Investigation of the ChoRE sequence indicated that two half E
box motifs are critical for the response to glucose. Electrophoretic mobility
shift assays revealed a complex formed between the mouse S(14) ChoRE and liver
nuclear proteins. This complex was also formed by ChoREs from the rat S(14) and L
PK genes but not by mutants of these sites that are inactive in supporting the
glucose response. These results suggest the presence of a novel transcription
factor complex that mediates the glucose-regulated transcription of S(14) and L
PK genes.
PMID- 10671568
TI - Requirement for protein-tyrosine phosphatase SHP-2 in insulin-induced activation
of c-Jun NH(2)-terminal kinase.
AB - Mitogen-activated protein kinases, including extracellular signal-regulated
kinases and c-Jun NH(2)-terminal kinases (JNKs), are activated by insulin.
Although the mechanism by which the insulin receptor activates extracellular
signal-regulated kinases is relatively well defined, the pathway that leads to
JNK activation is poorly understood. Overexpression of a catalytically inactive
mutant (SHP-2C/S) of the protein-tyrosine phosphatase SHP-2 in Rat-1 fibroblasts
that also express human insulin receptors has now revealed that activation of
JNKs by insulin and epidermal growth factor, but not that by anisomycin or
sorbitol, requires SHP-2. A dominant negative mutant (RasN17) of Ha-Ras blocked
insulin-induced JNK activation, whereas a dominant negative mutant (RacN17) of
Rac1 or a specific inhibitor (LY294002) of phosphoinositide 3-kinase did not,
indicating a role for Ras, but not for Rac or phosphoinositide 3-kinase, in this
effect. SHP-2C/S markedly inhibited Ras activation in response to insulin without
affecting insulin-induced tyrosine phosphorylation of cellular substrates or the
dissociation of the Crk-p130(Cas) complex. In contrast, SHP-2C/S did not inhibit
activation of JNKs induced by a constitutively active mutant (RasV12) of Ha-Ras.
Furthermore, expression of myristoylated SOS, which functions as a potent
activator of Ras, induced JNK activation even when SHP-2 was inactivated. These
results suggest that SHP-2 contributes to JNK activation in response to insulin
by positively regulating the Ras signaling pathway at the same level as, or
upstream from, SOS.
PMID- 10671569
TI - Identification of a novel sterol-independent regulatory element in the human low
density lipoprotein receptor promoter.
AB - The cytokine oncostatin M (OM) activates human low density lipoprotein receptor
(LDLR) gene transcription through a sterol-independent mechanism. Previous
studies conducted in our laboratory have narrowed the OM-responsive element to
promoter region -52 to +13, which contains the repeat 3 and two TATA-like
sequences. We now identify LDLR promoter region -17 to -1 as a sterol-independent
regulatory element (SIRE) that is critically involved in OM-, transcription
factor CCAAT/enhancer-binding protein (C/EBP)-, and second messenger cAMP
mediated activation of LDLR transcription. The SIRE sequence overlaps the
previously described TATA-like element and consists of an active C/EBP-binding
site (-17 to -9) and a functional cAMP-responsive element (CRE) (-8 to -1). We
demonstrate that (a) mutations within either the C/EBP or CRE site have no impact
on basal or cholesterol-mediated repression of LDLR transcription, but they
completely abolish OM-mediated activation of LDLR transcription; (b) replacing
the repeat 3 sequence that contains the Sp1-binding site with a yeast
transcription factor GAL4-binding site in the LDLR promoter construct does not
affect OM inducibility, thereby demonstrating that OM induction is mediated
through the SIRE sequence in conjunction with a strong activator bound to the
repeat 3 sequence; (c) electrophoretic mobility shift and supershift assays
confirm the specific binding of transcription factors C/EBP and cAMP-responsive
element-binding protein to the SIRE; (d) cotransfection of a human C/EBPbeta
expression vector (pEF-NFIL6) with the LDLR promoter construct pLDLR234 increases
LDLR promoter activity; and (e) OM and dibutyryl cAMP synergistically activate
LDLR transcription through this regulatory element. This study identifies, for
the first time, a cis-acting regulatory element in the LDLR promoter that is
responsible for sterol-independent regulation of LDLR transcription.
PMID- 10671570
TI - R-Ras contains a proline-rich site that binds to SH3 domains and is required for
integrin activation by R-Ras.
AB - R-Ras contains a proline-rich motif that resembles SH3 domain-binding sites but
that has escaped notice previously. We show here that this site in R-Ras is
capable of binding SH3 domains and that the SH3 domain binding may be important
for R-Ras function. A fusion protein containing the SH3 domains of the adaptor
protein Nck interacted strongly with the R-Ras proline-rich sequence and with the
intact protein. The binding was independent of whether R-Ras was in its GDP or
GTP form. The Nck binding, which was mediated by the second of the three SH3
domains of Nck, was obliterated by mutations in the proline-rich sequence of R
Ras. The interaction of Nck with R-Ras could also be shown in yeast two-hybrid
assays and by co-immunoprecipitation in human cells transfected with Nck and R
Ras. Previous results have shown that the expression of a constitutively active R
Ras mutant, R-Ras(38V), converts mouse 32D monocytic cells into highly adherent
cells. Introducing the proline mutations into R-Ras(38V) suppressed the effect of
R-Ras on 32D cell adhesion while not affecting GTP binding. These results reveal
an unexpected regulatory pathway that controls R-Ras through an SH3 domain
interaction. This pathway appears to be important for the ability of R-Ras to
control cell adhesion.
PMID- 10671571
TI - Platelet-derived growth factor rapidly increases activity and cell surface
expression of the EAAC1 subtype of glutamate transporter through activation of
phosphatidylinositol 3-kinase.
AB - Na(+)-dependent glutamate transporters are the primary mechanism for removal of
excitatory amino acids (EAAs) from the extracellular space of the central nervous
system and influence both physiologic and pathologic effects of these compounds.
Recent evidence suggests that the activity and cell surface expression of a
neuronal subtype of glutamate transporter, EAAC1, are rapidly increased by direct
activation of protein kinase C and are decreased by wortmannin, an inhibitor of
phosphatidylinositol 3-kinase (PI3-K). We hypothesized that this regulation could
be analogous to insulin-induced stimulation of the GLUT4 subtype of glucose
transporter, which is dependent upon activation of PI3-K. Using C6 glioma, a cell
line that endogenously and selectively expresses EAAC1, we report that platelet
derived growth factor (PDGF) increased Na(+)-dependent L-[(3)H]-glutamate
transport activity within 30 min. This effect of PDGF was not due to a change in
total cellular EAAC1 immunoreactivity but was instead correlated with an increase
cell surface expression of EAAC1, as measured using a membrane impermeant
biotinylation reagent combined with Western blotting. A decrease in
nonbiotinylated intracellular EAAC1 was also observed. These studies suggest that
PDGF causes a redistribution of EAAC1 from an intracellular compartment to the
cell surface. These effects of PDGF were accompanied by a 35-fold increase in PI3
K activity and were blocked by the PI3-K inhibitors, wortmannin and LY 294002,
but not by an inhibitor of protein kinase C. Other growth factors, including
insulin, nerve growth factor, and epidermal growth factor had no effect on
glutamate transport nor did they increase PI3-K activity. These studies suggest
that, as is observed for insulin-mediated translocation of GLUT4, EAAC1 cell
surface expression can be rapidly increased by PDGF through activation of PI3-K.
It is possible that this PDGF-mediated increase in EAAC1 activity may contribute
to the previously demonstrated neuroprotective effects of PDGF.
PMID- 10671572
TI - Essential role of human leukocyte antigen-encoded proteasome subunits in NF
kappaB activation and prevention of tumor necrosis factor-alpha-induced
apoptosis.
AB - The multisubunit proteasome complex is the principal mediator of nonlysosomal
protein degradation. The proteasome subunit varies minimally between cells with
the exception of LMP2, LMP7, and LMP10 subunits in rodent and human cells. LMP2
and LMP7 subunits are encoded by the human lymphocyte antigen region, and they
optimize proteolytic mediated antigen presentation. The proteasome is also
important for the function of transcription factor nuclear factor-kappaB (NF
kappaB). It is required for NF-kappaB subunits p50 and p52 generation and
catalyzes degradation of phosphorylated IkappaBalpha. These proteasome-mediated
reactions have now been shown to be defective in T2 cells, a human lymphocyte
cell line that lacks both LMP2 and LMP7. Although T2 cells contain normal
expression of p100 and p105, the abundance of p50 and p52 was greatly reduced.
Tumor necrosis factor-alpha (TNF-alpha) induced normal phosphorylation of
IkappaBalpha but failed to induce degradation of phosphorylated IkappaBalpha.
Both DNA binding assays and luciferase assays revealed that TNF-alpha-induced NF
kappaB activation is defective in T2 cells. Unlike parental cells, T2 cells were
susceptible to TNF-alpha-induced apoptosis. These data indicate human leukocyte
antigen-linked proteasome subunits are essential for NF-kappaB activation and
protection of cells from TNF-alpha-induced apoptosis.
PMID- 10671573
TI - Thoracic radiology: the past 50 years.
AB - The radiology of 50 years ago was a primitive science compared with the radiology
of today. Hospital departments were small and radiologists few in number. Night
call was uncommon. Examinations consisted primarily of radiographs of the chest,
bones, and gastrointestinal tract, although some early neuroradiologic studies
were performed. Chest fluoroscopy was common. Film processing was done manually,
often with poor results. Radiographic examinations of the chest were likewise
unsophisticated by today's standards. Chest radiographs were made with low
kilovoltage, calcium tungstate phosphors and relatively large focal spots. There
were no image intensifiers, nuclear medicine studies, ultrasonography, computed
tomography, or magnetic resonance studies. How far we have come!
PMID- 10671574
TI - 2000 RSNA leadership
PMID- 10671575
TI - An endangered art: teaching.
PMID- 10671576
TI - Public policy: the case for lobbying in radiology.
PMID- 10671577
TI - MR angiography in the evaluation of atherosclerotic peripheral vascular disease.
AB - Magnetic resonance (MR) angiography of lower extremity occlusive vascular disease
has evolved into a feasible diagnostic imaging option. The previous emphasis on
time-of-flight techniques was associated with lengthy acquisition times and
artifactual signal losses. Those limitations presented an obstacle to widespread
clinical implementation. However, the emergence of rapid imaging sequences
combined with gadolinium chelate enhancement offers time-efficient alternatives
that can yield a truer representation of the vascular anatomic structure. The
technology is now poised to serve as a routine screening study, provided that
radiologists understand all factors needed to generate clinically relevant MR
angiograms. This article is intended to provide a useful resource directed toward
achieving that understanding.
PMID- 10671578
TI - The dog leg sign.
PMID- 10671579
TI - Symptomatic vertebral hemangiomas: treatment by means of direct intralesional
injection of ethanol.
AB - PURPOSE: To describe the technique and results of injecting ethanol directly into
symptomatic vertebral hemangiomas. MATERIALS AND METHODS: Eleven patients with
paraplegia (n = 6) or radiculopathy (n = 5) due to vertebral hemangioma were
treated by means of injecting ethanol (5-50 mL) directly into the lesion with
computed tomographic (CT) guidance. CT angiograms were essential prior to
treatment to identify functional vascular spaces of the hemangioma and direct
needle placement. RESULTS: All hemangiomas were obliterated completely at follow
up angiography and gadolinium-enhanced magnetic resonance imaging. Five of six
patients with paraplegia recovered completely: One who was treated recently was
walking with assistance. Four of five patients with radiculopathy improved. No
immediate complications were associated with ethanol injection. The two patients
who received the largest volumes of ethanol, 42 and 50 mL, developed pathologic
fractures of the involved vertebrae 4 and 16 weeks after treatment. CONCLUSION:
Direct injection of ethanol into symptomatic vertebral hemangioma is an effective
and safe treatment, provided the dose is less than 15 mL.
PMID- 10671580
TI - Transarterial chemoembolization for hepatocellular carcinoma: volumetric and
morphologic CT criteria for assessment of prognosis and therapeutic success
results from a liver transplantation center.
AB - PURPOSE: To evaluate the prognostic value of volumetric computed tomography (CT)
for therapy control in patients treated with repeated transarterial
chemoembolization (TACE) for hepatocellular carcinoma (HCC). MATERIALS AND
METHODS: Eighty-five patients with histologically proved HCC underwent 182 TACE
procedures with 50 mg/m(2) doxorubicin hydrochloride, 50 mg/m(2) cisplatin, 10
mL/m(2) iodized oil, and amilomer microspheres. The volumes of liver and tumor
were measured with a region-of-interest CT technique. Iodized oil retention was
estimated with CT performed 24-48 hours after treatment. RESULTS: Tumor volume
expressed as a percentage of liver volume was less than 5% in 26, less than 15%
in 33, and 15% or greater in 26 patients. The overall 1-year survival rate was
57.6% (mean, 534 days; median, 428 days). There was a statistically significant
prolongation of survival when the tumor volume was less than 200 mL (P <.02) and
less than 5% of the liver volume (P <.01). Complete (>/=75%) and good (50%-74%)
iodized oil retention raised the median survival significantly (P <.001 and P
<.07, respectively). Significantly reduced survival correlated with diffuse tumor
growth pattern (P <.05) and presence of more than nine lesions (P <.03).
CONCLUSION: TACE resulted in significant prolongation of survival in patients
with tumor volumes of less than 200 mL, tumor-to-liver volume ratios of less than
5%, and iodized oil retention greater than or equal to 75%.
PMID- 10671581
TI - Percutaneous incision of stenotic uroenteric anastomoses with a cutting balloon
catheter: long-term results.
AB - PURPOSE: To describe the technique and results of incision of strictures in
anastomotic urinary diversions with a commercially available cutting balloon
catheter. MATERIALS AND METHODS: Thirty-seven stenoses were treated in 32
patients. Most (28 [88%]) of the patients had undergone surgery for bladder
cancer 17.7 months +/- 17.4 (SD) (range, 3-72 months) before incision. Thirteen
patients had undergone ileal conduit diversion, and nineteen had undergone
enterocystoplasty. All stenoses were shorter than 3 cm. The presence of adjacent
ileal loops and/or iliac vessels was assessed with computed tomography before
incision. The cutting wire was oriented anteriorly or anterolaterally, and the
balloon was inflated with diluted contrast material during the incision. A Kaplan
Meier survival curve was constructed to illustrate the success rates over time.
RESULTS: No major complications occurred. Twelve (32%) stenoses recurred in nine
patients 15 months +/- 10 (range, 6-36 months) after stent removal; the failure
rate was 53% (eight of 15 stenoses) for ileal conduits and 18% (four of 22
stenoses) for enterocystoplasties. Late failure (>12 months) was observed in four
patients. The patency of the other 25 stenoses (23 patients) was checked 25
months +/- 11 after stent removal (range, 5-43 months). The actuarial patency
rate was 77% at 1 year, 68% at 2 years, and 62% at 3 years. CONCLUSION: Cutting
balloon incision is a safe and simple alternative to surgery, particularly when
the urinary diversion is enterocystoplasty.
PMID- 10671582
TI - Improved uniformity of aortic enhancement with customized contrast medium
injection protocols at CT angiography.
AB - PURPOSE: To compare the uniformity of aortoiliac opacification obtained from
uniphasic contrast medium injections versus individualized biphasic injections at
computed tomographic (CT) angiography. MATERIALS AND METHODS: Thirty-two patients
with an abdominal aortic aneurysm underwent CT angiography. In 16 patients (group
1), 120 mL of contrast material was administered at a flow rate of 4 mL/sec. In
the other 16 patients (group 2), biphasic injection protocols were computed by
using mathematic deconvolution of each patient's time-attenuation response to a
standardized test injection. Attenuation uniformity was quantified as the
"plateau deviation" of enhancement values, which were calculated as the SD of the
time-contiguous attenuation values observed during the 30-second scanning period.
RESULTS: Group 2 patients received between 77 and 165 mL (mean, 115 mL) of
contrast medium. Initial flow rates ranged from 4.1 to 10.0 mL/sec (mean, 6.8
mL/sec) for the first 4-6 seconds; continuing flow rates ranged from 2.0 to 4.8
mL/sec (mean, 3.1 mL/sec) for the remaining 24-26 seconds. The plateau deviation
was significantly smaller in group 2 patients (19 HU) versus group 1 patients (38
HU, P <.001). CONCLUSION: At CT angiography, tailored biphasic injections led to
more uniform aortoiliac enhancement, compared with standard uniphasic injections
of contrast medium.
PMID- 10671583
TI - Renal arterial stenosis: prospective comparison of color Doppler US and breath
hold, three-dimensional, dynamic, gadolinium-enhanced MR angiography.
AB - PURPOSE: To compare color Doppler ultrasonography (US) with fast, breath-hold,
three-dimensional, gadolinium-enhanced magnetic resonance (MR) angiography in
detecting renal arterial stenosis. MATERIALS AND METHODS: Forty-five patients
with clinical suspicion of renovascular disease were prospectively examined with
intra- and extrarenal color Doppler US and breath-hold, gadolinium-enhanced MR
angiography. Digital subtraction arteriography (DSA) was the standard of
reference in all patients for the number of renal arteries and degree of
stenosis. RESULTS: DSA depicted 103 arteries and 52 stenoses. Color Doppler US
was nondiagnostic in two examinations. Significantly more of 13 accessory renal
arteries were detected with MR angiography (n = 12) than with color Doppler US (n
= 3; P <.05). For assessing all stenoses, the sensitivity and accuracy were 94%
and 91%, respectively, for MR angiography and 71% and 76%, respectively, for US
(P <.05). The sensitivity was higher for MR angiography (100%) than for US (79%;
P <.05) in diagnosing stenoses with at least 50% narrowing. The specificity,
accuracy, and negative predictive value in diagnosing stenoses of at least 50%
narrowing were 93%, 95%, and 100% for MR angiography and 93%, 89%, and 90% for
US. CONCLUSION: Breath-hold, gadolinium-enhanced MR angiography is superior to
color Doppler US in accessory renal artery detection. Although the specificity of
MR angiography is similar to that of color Doppler US, MR angiography has a
better sensitivity and negative predictive value in depicting renal arterial
stenoses.
PMID- 10671584
TI - Vascularity of hepatocellular carcinoma: assessment with contrast-enhanced second
harmonic versus conventional power Doppler US.
AB - PURPOSE: To compare contrast material-enhanced harmonic power Doppler
ultrasonography (US) with conventional power Doppler US in depicting the
vascularity of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty
patients with nodular HCCs (2.6-13.2 cm in diameter; mean diameter, 4.8 cm) were
prospectively examined with both conventional and harmonic power Doppler US. US
was performed with a 2-4-MHz curved linear-array transducer according to a
standard examination protocol (1,000-Hz pulse repetition frequency, medium wall
filter, and power gain of 55%-84% for conventional power Doppler US; 700-Hz pulse
repetition frequency, low wall filter, and power gain of 95%-98% for harmonic
power Doppler US). Serial, dynamic scans were obtained before intravenous
injection of the contrast agent (SH U 508A) and at 30, 60, 90, 120, 180, 240, and
300 seconds after injection with both techniques. RESULTS: The number of
intratumoral power Doppler US signals was similar with both techniques at 30-90
seconds after contrast agent injection; however, after 90 seconds, conventional
power Doppler US depicted significantly more signals than did harmonic power
Doppler US. Harmonic power Doppler US was superior to conventional power Doppler
US in terms of power Doppler artifacts such as "blooming" or motion-related
artifacts. CONCLUSION: Although the effective enhancement duration is relatively
short compared with that for conventional power Doppler US, contrast-enhanced
harmonic power Doppler US can be effective in evaluating the vascularity of HCCs
because of the advantage of fewer power Doppler artifacts.
PMID- 10671585
TI - Variability of Doppler US measurements along the common carotid artery: effects
on estimates of internal carotid arterial stenosis in patients with
angiographically proved disease.
AB - PURPOSE: To determine the effect of variability of common carotid arterial (CCA)
velocities on velocity ratios used to assess internal carotid arterial (ICA)
stenosis. MATERIALS AND METHODS: Doppler ultrasonographic (US) velocity
measurements were obtained at three levels in the CCA and in the carotid bulb and
ICA in all patients referred for carotid US between September 1996 and October
1997. Only ICAs (n = 98, in 57 patients) without ipsilateral CCA disease at
angiography were analyzed. The range of CCA peak systolic velocities (PSVs) and
end diastolic velocities (EDVs) and velocity ratios were calculated for each CCA
measurement. For each ICA/CCA velocity ratio, receiver operating characteristic
analysis was performed. RESULTS: CCA PSV and EDV ranges averaged 23.1 cm/sec +/-
15.7 (SD) and 5.1 cm/sec +/- 3.6, respectively. For a given side, the difference
averaged 1.0 +/- 1.3 for PSV ratios and 2.7 +/- 6.9 for EDV ratios, depending on
where CCA measurements were taken. By using a threshold of 60% stenosis as
indication for endarterectomy, variability in CCA velocities could have altered
recommendations in 16 (28%) of 57 patients. Receiver operating characteristic
analysis showed that ratios made by using the three CCA velocities or their mean
were not significantly different. CONCLUSION: Variability in velocity
measurements along the course of the CCA in patients with ICA disease can be
substantial and can result in inaccuracies in assessment of carotid stenosis.
PMID- 10671586
TI - Parathyroid glands: combination of (99m)Tc MIBI scintigraphy and US for
demonstration of parathyroid glands and nodules.
AB - PURPOSE: To determine the appropriate choice of imaging techniques for
localization of nodular lesions of parathyroid glands. MATERIALS AND METHODS:
First, computed tomographic (CT), magnetic resonance (MR), ultrasonographic (US),
and technetium 99m methoxyisobutyl-isonitrile (MIBI) scintigraphic images in 49
patients with primary hyperparathyroidism were retrospectively evaluated. A
single-blind, prospective study that included 16 patients with primary
hyperparathyroidism was then conducted. MR, US, scintigraphic, and color Doppler
US images of the neck were obtained and analyzed. RESULTS: In the retrospective
study, CT, MR imaging, and US had low sensitivity (13%, 17%, and 27%,
respectively) and specificity (39%, 65%, and 65%, respectively). Scintigraphy had
57% sensitivity and 85% specificity. In the prospective study, the use of latest
generation MR and US equipment and the participation of experienced operators led
to improved sensitivity and specificity for these techniques. The combination of
US and scintigraphy resulted in improved sensitivity (96%), specificity (83%),
and positive and negative predictive values (88% and 94%, respectively), relative
to the results obtained with either method alone. Doppler US was of little help
in the setting of small glands. CONCLUSIONS: The combination of (99m)Tc MIBI
scintigraphy and US performed by well-trained operators with up-to-date
instruments appeared to be the best diagnostic tool for the preoperative
diagnosis of parathyroid disease.
PMID- 10671587
TI - Hippocampal structures: anteroposterior N-acetylaspartate differences in patients
with epilepsy and control subjects as shown with proton MR spectroscopic imaging.
AB - PURPOSE: To determine the distribution of proton metabolites along the long axis
of the hippocampus. MATERIALS AND METHODS: Proton magnetic resonance (MR)
spectroscopic imaging measurements were performed in the hippocampi of 14 control
subjects and nine patients with unilateral mesial temporal lobe epilepsy.
RESULTS: Control subjects showed significantly lower ratios of N-acetylaspartate
(NAA) to choline-containing compounds (Ch) and creatine plus phosphocreatine (CR)
(NAA/[Cr + Ch]) in the anterior as compared with the posterior part of the
hippocampus. Furthermore, a similar anteroposterior (AP) difference in NAA/(Cr +
Ch) values was found in both ipsilateral and contralateral hippocampi of
patients. In the patients compared with the control subjects, ipsilateral NAA/(Cr
+ Ch) levels were reduced in every part of hippocampal tissue with an average
reduction of 17%, and contralateral NAA/(Cr + Ch) was reduced by about 10%. In
the patients compared with the control subjects, the proportional reduction in
ipsilateral NAA/(Cr + Ch) was greatest in voxels from anterior hippocampal
regions. CONCLUSION: AP differences could be a result of fewer neurons in the
anterior compared with the posterior hippocampus or of the increasing thickness
of the hippocampus from posterior to anterior, which leads to different
contributions from adjacent tissue. Measurements of T2 showed that T2 differences
are probably not responsible for these changes.
PMID- 10671588
TI - Central nervous system sarcoidosis: follow-up at MR imaging during steroid
therapy.
AB - PURPOSE: To document the changes observed at sequential magnetic resonance (MR)
imaging of sarcoidosis lesions of the central nervous system (CNS) during
treatment with corticosteroids. MATERIALS AND METHODS: The abnormalities detected
in 24 patients (mean follow-up, 36 months) were compared before and after
therapeutic periods (n = 75) that were divided into attack (high-dose), upkeep
(decreased-dose), and minimal (low-dose) periods. Parenchymal lesions were
classified as type 1 (enhanced with gadolinium), type 2 (demyelinating), or type
3 (lacunar) and were assessed as regressing, stable, or progressing. RESULTS:
Seven of the 24 patients had several types of lesions. Isolated type 3 lesions
(six patients) were the only lesions not associated with neurologic deficit. Type
1 lesions (13 patients) regressed in 22 of 22 attack periods and progressed in
nine of 27 upkeep and minimal periods. MR imaging depicted relapses in patients
with multifocal CNS involvement or long-standing CNS impairment or in those who
had previously received steroid therapy. Type 2 (seven patients) and type 3 (13
patients) lesions remained stable in 68 of 68 therapeutic periods. Type 1 lesions
appeared in three patients with type 2 and type 3 lesions during two upkeep and
three minimal periods. Findings at follow-up MR imaging contributed to the
reintroduction of high-dose corticosteroid therapy in eight patients. CONCLUSION:
MR imaging can be used to differentiate between reversible and irreversible
lesions in CNS sarcoidosis. MR imaging can be a useful tool for adjusting
treatment to prevent irreversible CNS damage.
PMID- 10671589
TI - Hematologic toxic reaction to radiation therapy adjuvant to autologous peripheral
blood stem cell transplantation for recurrent or refractory Hodgkin disease.
AB - PURPOSE: To evaluate the hematologic toxic reaction to external-beam radiation
therapy after high-dose chemotherapy with peripheral blood stem cell (PBSC)
support in patients with Hodgkin disease. MATERIALS AND METHODS: A retrospective
study of 30 cases of Hodgkin disease in patients who underwent high-dose
carmustine, etoposide, and cyclophosphamide chemotherapy with PBSC support was
performed. Thirteen patients underwent radiation therapy (28.8-39.0 Gy) a median
of 45 days after PBSC repeat infusion. RESULTS: Radiation therapy was delivered
as planned, without interruption, in all patients. Five patients developed
thrombocytopenia (one with grade 1 thrombocytopenia; two, grade 2; and two, grade
3) and included three with progressive disease prior to radiation therapy and two
with a history of prior irradiation. None developed a bleeding complication or
required transfusion support. Five patients who underwent irradiation had
thrombocytopenia (three with grade 1 and two with grade 2) 100 days after PBSC
repeat infusion, compared with three patients (two with grade 1 and one with
grade 3) who did not undergo posttransplantation irradiation. At the most recent
follow-up, no patient without evidence of disease had a platelet count of less
than 100 x 10(9)/L. CONCLUSION: External-beam radiation therapy was well
tolerated in the posttransplantation setting in patients with Hodgkin disease.
Thrombocytopenia was common but was not related to clinical complications.
PMID- 10671590
TI - Multiple pulmonary nodules in AIDS: usefulness of CT in distinguishing among
potential causes.
AB - PURPOSE: To determine whether the computed tomographic (CT) appearances of
multiple pulmonary nodules in patients with acquired immunodeficiency syndrome
(AIDS) can help differentiate the potential infectious and neoplastic causes.
MATERIALS AND METHODS: The thoracic CT scans obtained in 60 patients with AIDS
and multiple pulmonary nodules were reviewed retrospectively by two thoracic
radiologists who were blinded to clinical and pathologic data. The scans were
evaluated for nodule size, distribution, and morphologic characteristics. CT
findings were correlated with final diagnoses. RESULTS: Thirty-six (84%) of 43
patients with opportunistic infection had a predominance of nodules smaller than
1 cm in diameter, whereas 14 (82%) of 17 patients with a neoplasm had a
predominance of nodules larger than 1 cm (P <.001). Of the 43 patients with
opportunistic infection, 28 (65%) had a centrilobular distribution of nodules;
only one (6%) of 17 patients with a neoplasm had this distribution (P <.001).
Seven (88%) of eight patients with a peribronchovascular distribution had Kaposi
sarcoma (P <.001). CONCLUSION: In patients with AIDS who have multiple pulmonary
nodules at CT, nodule size and distribution are useful in the differentiation of
potential causes. Nodules smaller than 1 cm, especially those with a
centrilobular distribution, are typically infectious. Nodules larger than 1 cm
are often neoplastic. A peribronchovascular distribution is suggestive of Kaposi
sarcoma.
PMID- 10671591
TI - Segmental and subsegmental pulmonary arteries: evaluation with electron-beam
versus spiral CT.
AB - PURPOSE: To compare contrast agent-enhanced spiral and electron-beam computed
tomography (CT) for the analysis of segmental and subsegmental pulmonary
arteries. MATERIALS AND METHODS: CT angiography of the pulmonary arteries was
performed in 56 patients to rule out pulmonary embolism. Electron-beam CT was
performed in 28 patients. The other 28 patients underwent spiral CT with
comparable scanning protocols. The depiction of segmental and subsegmental
arteries was analyzed by three independent readers. The contrast enhancement in
the main pulmonary artery was measured in each patient. RESULTS: Analysis was
performed in 1,120 segmental and 2, 240 subsegmental arteries. One segmental
(RA7, P =.010) and two subsegmental (LA7b, P =.029; RA6a+b, P =.038) arteries in
paracardiac and basal segments of the lung were depicted significantly better
with electron-beam CT. There was no statistically significant difference between
electron-beam and spiral CT in the total number of analyzable peripheral arteries
depicted. The mean contrast enhancement in the main pulmonary artery was 362 HU
in electron-beam CT studies versus 248 HU in spiral CT studies. CONCLUSION:
Detailed visualization of peripheral pulmonary arteries is well within the scope
of advanced CT techniques. Electron-beam CT has minor advantages in analyzing
paracardiac arteries, probably because of reduction of motion artifacts and
higher contrast enhancement. Further studies are needed to establish whether
electron-beam CT allows a more confident diagnosis of emboli in these vessels.
PMID- 10671592
TI - Pulmonary lymphangioleiomyomatosis: correlation of ventilation-perfusion
scintigraphy, chest radiography, and CT with pulmonary function tests.
AB - PURPOSE: To determine the findings on ventilation-perfusion (V-P) scintigrams,
computed tomographic (CT) scans, and chest radiographs and correlate them with
pulmonary function test results in patients with lymphangioleiomyomatosis.
MATERIALS AND METHODS: V-P scintigraphy, chest radiography, conventional and thin
section CT, and pulmonary function tests were performed in 39 patients. The
images were graded on a scale of 0 (normal) to 3 (severely abnormal). RESULTS:
Imaging abnormalities were found on 92% of ventilation scintigrams, 92% of
perfusion scintigrams, 79% of chest radiographs, 100% of CT scans, and 100% of
thin-section CT scans. On ventilation scintigrams, 28 (72%) patients demonstrated
a speckling pattern. On CT scans, all patients had pulmonary cysts. Univariate
analysis showed that extent of disease on chest radiographs and CT scans, cyst
size, V-P abnormalities, and degree of speckling were inversely correlated with
forced expiratory volume in one second (FEV(1)), diffusing capacity of lung for
carbon monoxide, and the ratio of FEV(1) to forced vital capacity (FVC) (P <.01)
but not with FVC and total lung capacity. Larger cyst size correlated with extent
of disease at CT, but not significantly (P =.056). CONCLUSION: Scintigraphic and
radiologic abnormalities are seen in a majority of patients with
lymphangioleiomyomatosis. On ventilation scintigrams, a frequently seen speckling
pattern may be related to accumulation of radionuclide in pulmonary cysts-a
hallmark of the disease at CT. Findings with each imaging modality correlate with
certain pulmonary functions.
PMID- 10671593
TI - Coronary arterial stent patency: assessment with electron-beam CT.
AB - PURPOSE: To evaluate electron-beam computed tomography (CT) for stent
localization and noninvasive assessment of stent patency in patients with
coronary arterial stents and coronary bypass stents. MATERIALS AND METHODS: CT in
the single-section volume mode was performed in 202 patients with 321 coronary
arterial stents in 221 vessels to localize the stents. Patency was evaluated in
the multisection flow mode with an intravenous bolus injection of contrast
material. All electron-beam CT images were reviewed by an observer who had no
knowledge of the coronary angiographic results. Electron-beam CT findings were
then compared with coronary angiographic findings. RESULTS: The stents could be
visualized and related to the coronary arterial segments in 216 of 221 vessels
with electron-beam CT. Of the 221 vessels, 207 were correctly evaluated with
electron-beam CT. Compared with coronary angiography, electron-beam CT permitted
the detection of 18 of 23 high-grade stenoses (sensitivity, 78%) and correctly
depicted the absence of high-grade stenoses in 189 of 193 vessels with stents
(specificity, 98%). Altogether, 18 stenoses were detected correctly at electron
beam CT; the interpretation was false-positive in four vessels (positive
predictive value, 82% [18/22 vessels]) and false-negative in five (negative
predictive value, 97% [189/194 vessels]). CONCLUSION: Electron-beam CT may be
helpful in localizing intracoronary stents and assessing stent patency
noninvasively to delay the intervals between catheterizations in an increasing
number of patients.
PMID- 10671594
TI - Three-dimensional systolic strain patterns in the normal human left ventricle:
characterization with tagged MR imaging.
AB - PURPOSE: To present a database of systolic three-dimensional (3D) strain
evolution throughout the normal left ventricle (LV) in humans. MATERIALS AND
METHODS: In 31 healthy volunteers, magnetic resonance (MR) tissue tagging and
breath-hold MR imaging were used to generate and then detect the motion of
transient fiducial markers (ie, tags) in the heart every 32 msec. Strain and
motion were calculated from a 3D displacement field that was fit to the tag data.
Special indexes of contraction and thickening that were based on multiple strain
components also were evaluated. RESULTS: The temporal evolution of local strains
was linear during the first half of systole. The peak shortening and thickening
strain components were typically greatest in the anterolateral wall, increased
toward the apex, and increased toward the endocardium. Shears and displacements
were more spatially variable. The two specialized indexes of contraction and
thickening had higher measurement precision and tighter normal ranges than did
the traditional strain components. CONCLUSION: In this study, the authors
noninvasively characterized the normal systolic ranges of 3D displacement and
strain evolution throughout the human LV. Comparison against this
multidimensional database may permit sensitive detection of systolic LV
dysfunction.
PMID- 10671595
TI - Arterial switch procedure for D-transposition of the great arteries: quantitative
midterm evaluation of hemodynamic changes with cine MR imaging and phase-shift
velocity mapping-initial experience.
AB - PURPOSE: To evaluate cine magnetic resonance (MR) imaging and phase-shift
velocity mapping for assessment of the hemodynamic relevance of stenotic segments
or specific hemodynamic changes in the great vessels after an arterial switch
procedure for correction of D-transposition of the great arteries. MATERIALS AND
METHODS: Twenty consecutive patients (age range, 2-17 years) with an acoustic
window that was insufficient for Doppler transthoracic echocardiography were
included in the study. Flow and diameter measurements of the pulmonary arterial
trunk and its primary branches were performed with phase-shift velocity mapping
and cine MR imaging. RESULTS: There were good correlations between pressure
gradients in the pulmonary arteries estimated with MR imaging and those measured
with Doppler echocardiography (r = 0.83, n = 15) and cardiac catheterization (r =
0.90, n = 13). Cine MR imaging revealed that the diameters of the right and left
pulmonary arteries decreased with the expansion of the aorta during systole,
which increased the peak velocity. This temporary stenosis was more severe in the
right than in the left pulmonary artery and was accompanied by a significantly (P
<.05) lower volume flow in the right artery. CONCLUSION: The anatomic situation
after arterial switch repair tended to produce temporary stenoses in the primary
pulmonary arterial branches, with significant changes in hemodynamics. These
changes may affect the long-term outcome and go undetected with other imaging
modalities.
PMID- 10671596
TI - Pancreatoblastoma: imaging findings in 10 patients and review of the literature.
AB - PURPOSE: To describe the features of pancreatoblastoma at magnetic resonance (MR)
imaging, computed tomography (CT), and ultrasonography (US). MATERIALS AND
METHODS: Imaging and surgical findings in 10 patients (age range, 2-20 years;
mean age, 6.8 years) with pathologically proved pancreatoblastoma were reviewed
for tumor size, organ of origin, definition and quality of tumor margins, tumor
heterogeneity, calcification, enhancement, ascites, biliary and/or pancreatic
ductal dilatation, local invasion, adenopathy, vascular invasion, vascular
encasement, metastases, and signal intensity on MR images. Results from 10 CT,
seven US, and three MR imaging examinations were reviewed. RESULTS: Five of the
10 tumors were pancreatic; four others appeared to be pancreatic or hepatic. Most
had well-defined margins (nine of 10), were heterogeneous (nine of 10), and
enhanced (10 of 10). Other findings included calcification (two of 10), biliary
and pancreatic ductal dilatation (one of 10), and ascites (three of 10). Hepatic
(two patients) and pelvic (two patients) metastases were present. Adenopathy (two
patients) and vascular invasion (one patient) were not identified radiologically.
Tumors had low to intermediate signal intensity on T1-weighted images and high
signal intensity on T2-weighted images. CONCLUSION: Pancreatoblastoma is
typically a heterogeneous tumor with well-defined margins that may appear to
arise from the pancreas or liver. It may behave aggressively, with localized
vascular or bowel invasion or with widespread metastatic disease. Although it is
rare, it should be considered in the differential diagnosis of an upper abdominal
mass in a child.
PMID- 10671597
TI - Detection of small, functional islet cell tumors in the pancreas: selection of MR
imaging sequences for optimal sensitivity.
AB - PURPOSE: To determine the sensitivity and specificity of magnetic resonance (MR)
imaging for depicting pancreatic small, functional islet cell tumors and the
minimum number of sequences for expedient diagnosis. MATERIALS AND METHODS:
Twenty-eight patients clinically suspected to have functional islet cell tumors
underwent T1- and T2-weighted spin-echo (SE) MR imaging with and without fat
suppression, T2-weighted fast SE imaging, and spoiled gradient-echo (GRE) imaging
before and after injection of gadopentetate dimeglumine. Sensitivity,
specificity, and the best and minimum number of sequences for definitive
diagnosis were determined. RESULTS: MR images depicted proved islet cell tumors
in 17 of 20 patients (sensitivity, 85%). Images were true-negative in eight
patients with negative follow-up examination results for more than 1 year.
Specificity was 100%; positive predictive value, 100%; and negative predictive
value, 73%. Among 20 patients with tumor, T1-weighted SE images with fat
suppression and nonenhanced spoiled GRE images each showed lesions in 15 (75%);
T2-weighted conventional SE with fat suppression, in 13 (65%); gadolinium
enhanced spoiled GRE, in 12 (60%); and T2-weighted fast SE, in seven of 10
patients (70%). CONCLUSION: MR imaging accurately depicts small islet cell
tumors. T2-weighted fast SE and spoiled GRE sequences usually suffice. Gadolinium
enhanced sequences are needed only if MR imaging results are equivocal or
negative.
PMID- 10671598
TI - Anatomy of the right anterosuperior area (segment 8) of the liver: evaluation
with helical CT during arterial portography.
AB - PURPOSE: To evaluate the segmental anatomy of the right anterosuperior area
(segment 8) of the liver by using helical computed tomography during arterial
portography (CTAP). MATERIALS AND METHODS: Twenty-seven patients without lesions
at segment 8 underwent helical CTAP. Three-dimensional portograms were
reconstructed to verify the course of the portal veins. The number of
subsegmental branches, in addition to the branching point and the distribution in
segment 8, was assessed. RESULTS: In 25 (93%) patients, the dorsal branch of
segment 8 gave rise to dorsally directed branches posterior to the right hepatic
vein. In only four (25%) of 16 patients in whom the medial branch of segment 8
arose near the porta hepatis, the long paracaval portal branch of the caudate
lobe extended upward above the interval between the middle and right hepatic
veins. CONCLUSION: In most of the patients, the dorsal branches of segment 8
supplied the dorsocranial area of the right lobe posterior to the right hepatic
vein. The paracaval portion of the caudate lobe was limited to below the interval
between the middle and right hepatic veins in the majority of patients who showed
medial branches of segment 8 arising near the porta hepatis. Recognition of this
vascular anatomy is clinically important for preoperative evaluation of hepatic
tumors in segment 8 because it may contribute to a safer surgical approach.
PMID- 10671599
TI - Diagnosis of gastric cancers: comparison of conventional radiography and digital
radiography with a 4 million-pixel charge-coupled device.
AB - PURPOSE: To evaluate the differences in accuracy and observer performance at
conventional radiography and at digital radiography with a 4 million-pixel charge
coupled device (CCD) for the diagnosis of gastric cancers. MATERIALS AND METHODS:
A prospective study was performed of 225 patients with suspected gastric cancer
who were referred to our hospital from January 1997 through February 1997. One
hundred twelve patients were examined at conventional radiography and 113 were
examined at digital radiography, and 24 and 27 patients had gastric cancer,
respectively. Six radiologists interpreted the images, with attention to tumor
findings. They were blinded to the clinical details, and their interpretations
were rated against those of three other radiologists who examined the patients
and who were aware of the clinical information such as endoscopic features and/or
histopathologic findings in biopsy specimens. Receiver operating characteristic
(ROC) analysis was used to compare the differences in observer performance for
the diagnosis of gastric cancers at conventional radiography and at digital
radiography. RESULTS: The overall sensitivity was 64.6% at conventional
radiography versus 75.3% at digital radiography (P =. 287); specificities were
84.5% and 90.5%, respectively (P =.011); and the positive predictive values were
53.1% and 71.3%, respectively (P =.036). ROC analysis clearly showed higher
diagnostic performance at digital radiography than at conventional radiography.
CONCLUSION: The data demonstrate the high diagnostic value of digital radiography
with a 4 million-pixel CCD for gastric cancers. The technique has considerable
potential as an alternative to conventional gastrointestinal radiography.
PMID- 10671600
TI - MR imaging for the preoperative planning of sphincter-saving surgery for tumors
of the lower third of the rectum: use of intravenous and endorectal contrast
materials.
AB - PURPOSE: To evaluate the value of magnetic resonance (MR) imaging with a flexible
surface coil in predicting the resectability of tumors in the lower rectum and
the feasibility of sphincteral salvage. MATERIALS AND METHODS: In a prospective
study, 61 patients with histologically proved primary adenocarcinoma of the lower
or middle third of the rectum (<12 cm from the pectinate line) were examined at
double-contrast-material-enhanced MR imaging with a circular polarized flexible
surface coil. RESULTS: Assessment of anal sphincteral infiltration at MR imaging
was excellent, with a specificity of 98% and a sensitivity of 100%. In the
determination of tumor infiltration into adjacent organs (T4), the specificity
was 100%, and the sensitivity was 90%, with surgical and histologic findings as
the standards. While MR imaging showed negative nodes in 40 patients (stage N0 at
MR imaging), histologic examination showed negative nodes in 27 patients and
positive nodes in 34. At MR imaging, sensitivity was 68%, and specificity was
24%. CONCLUSION: While preoperative staging at MR imaging according to the TNM
system still has limited value and accuracy, MR imaging provides the surgeon with
valuable information regarding the presence of sphincteral invasion and the
surrounding structures in patients with cancers in the lower third of the rectum.
PMID- 10671601
TI - Ileal endometriosis: radiographic findings in five cases.
AB - PURPOSE: To determine the radiographic findings in five patients with ileal
endometriosis. MATERIALS AND METHODS: A search of radiology files revealed five
patients with surgically proved endometriotic implants in the ileum at
enteroclysis (three patients), at small-bowel follow-through (one patient), and
at double-contrast barium enema study (one patient). The radiographic findings
were reviewed retrospectively. Clinical, surgical, and histopathologic findings
were also reviewed. RESULTS: All five patients were nulliparous women (mean age,
34.4 years; age range, 28-41 years). Four patients presented with abdominal
and/or pelvic pain, but only one of these four had cyclic pain that coincided
with menstruation. Barium studies revealed endometriotic implants in the terminal
ileum within 10 cm of the ileocecal valve in four patients and in the mid-ileum
in one. The radiographic findings consisted of extrinsic mass effect with
variable spiculation and tethering of folds in two patients, annular lesions with
spiculated folds and abrupt or tapered borders in two, and a plaque-like lesion
in one. In four patients who underwent double-contrast barium enema studies,
associated endometriotic implants were found in the rectosigmoid colon.
CONCLUSION: Ileal endometriosis usually involves the terminal ileum within 10 cm
of the ileocecal valve and manifests as a spectrum of findings on barium studies.
Ileal endometriosis should therefore be considered when these findings are
present in young, nulliparous women with abdominal or pelvic pain.
PMID- 10671602
TI - Isolated infarction of the cecum: CT findings in two patients.
AB - Colonic ischemia isolated to the cecum is a rare entity. The authors evaluated
two patients who underwent computed tomography (CT) because appendicitis was
suspected at clinical examination. CT findings were suggestive of isolated cecal
ischemia or infarction. Surgical-histopathologic findings helped confirm the
presumptive CT diagnoses. Isolated cecal infarction should be included in the
differential diagnosis of acute right lower quadrant pain.
PMID- 10671603
TI - Mucosal detail at CT virtual reality: surface versus volume rendering.
AB - PURPOSE: To evaluate computed tomographic virtual reality with volumetric versus
surface rendering. MATERIALS AND METHODS: Virtual reality images were
reconstructed for 27 normal or pathologic colonic, gastric, or bronchial
structures in four ways: the transition zone (a) reconstructed separately from
the wall by using volume rendering; (b) with attenuation equal to air; (c) with
attenuation equal to wall (soft tissue); (d) with attenuation halfway between air
and wall. The four reconstructed images were randomized. Four experienced imagers
blinded to the reconstruction graded them from best to worst with predetermined
criteria. RESULTS: All readers rated images with the transition zone as a
separate structure as overwhelmingly superior (P <.001): Nineteen cases had
complete concurrence among all readers. The best of the surface-rendering
reconstructions had the transition zone attenuation equal to the wall attenuation
(P <.001). The third best reconstruction had the transition zone attenuation
equal to the air attenuation, and the worst had the transition zone attenuation
halfway between the air and wall attenuation. CONCLUSION: Virtual reality is best
with volume rendering, with the transition zone (mucosa) between the wall and air
reconstructed as a separate structure.
PMID- 10671604
TI - Case 23(1)
PMID- 10671605
TI - Diagnosis please. Case 19: enteroliths in a Meckel diverticulum.
PMID- 10671606
TI - Primary hyperaldosteronism (Conn syndrome): MR imaging findings.
AB - PURPOSE: To describe the magnetic resonance (MR) imaging features of the adrenal
glands in primary hyperaldosteronism and assess MR imaging in the detection and
characterization of aldosterone-producing adenoma (APA). MATERIALS AND METHODS:
The authors retrospectively reviewed the cases of 20 patients (13 female and
seven male patients; age range, 14-67 years; median age, 46 years) with primary
hyperaldosteronism who underwent 1.5-T MR imaging between 1995 and 1998. All
patients underwent transverse T1- and T2-weighted imaging, and chemical shift
imaging was performed in 17 patients. Imaging results were correlated with
findings at biochemical testing, venous sampling, or surgery. RESULTS: Among the
20 patients, 10 (50%) had APA and 10 (50%) bilateral adrenal hyperplasia (BAH).
In the detection of APA, MR imaging had a sensitivity of 70%, specificity of
100%, and accuracy of 85%. APAs (mean size, 20 x 16 mm) were iso- or hypointense
relative to the liver on T1-weighted images and slightly hyperintense on T2
weighted images. With chemical shift imaging, the signal intensity decreased on
the out-of-phase images in six of seven (86%) patients with APA and in eight of
nine (89%) patients with BAH. CONCLUSION: MR imaging has a high specificity in
the detection of APA. As with nonhyperfunctioning adenoma, APA and BAH show
evidence of intracellular lipid at chemical shift imaging.
PMID- 10671607
TI - Cerebellar and frontal lobe hypoplasia in fetuses with trisomy 21: usefulness as
combined US markers.
AB - PURPOSE: To confirm that cerebellar hypoplasia is ultrasonographically
recognizable in second-trimester fetuses with Down syndrome and determine whether
the combination of frontal lobe shortening and cerebellar hypoplasia is superior
to either measurement alone as a marker of this abnormality. MATERIALS AND
METHODS: The frontothalamic distance (FTD) and transcerebellar diameter (TCD)
were measured in 52 middle-trimester fetuses with euploid karyotypes and in 52
fetuses with Down syndrome. Receiver operating characteristic (ROC) curves were
constructed with various thresholds for observed-to-expected ratios (O/Es) of the
FTD, TCD, and average of these two parameters. RESULTS: The area under the
average ROC curve, 0.80, was greater than that for either the FTD alone (0.75) or
the TCD alone (0.76). At a 6% false-positive rate, the sensitivity for the
detection of Down syndrome obtained with the average parameter was 34% better
than that obtained with only the FTD and 12% better than that obtained with only
the TCD. With an O/E threshold of 0.92 for the average parameter, an odds ratio
of 16.3 and positive predictive value of 12.7% in the high-risk population were
achieved. CONCLUSION: Although both measurements are individually statistically
significant, the combination of TCD and FTD measurements may be superior to the
use of either parameter alone as a marker of trisomy 21.
PMID- 10671608
TI - Cartilaginous tumors: fast contrast-enhanced MR imaging.
AB - PURPOSE: To differentiate between benign and malignant cartilaginous tumors with
fast contrast material-enhanced magnetic resonance (MR) imaging. MATERIALS AND
METHODS: In 37 patients, fast contrast-enhanced MR images were obtained in eight
enchondromas, 11 osteochondromas, and 18 chondrosarcomas. Start of enhancement
early, within 10 seconds after arterial enhancement; delayed, between 10 seconds
and 2 minutes; late, after 5 minutes on spin-echo images-and progression of
enhancement were represented with three types of time-signal intensity curves.
Findings were correlated with the surgical specimen in 27 cases, curettage
material in three cases, and biopsy combined with long-term follow-up findings in
seven cases. RESULTS: Start of enhancement and the combination of start and
progression of enhancement correlated significantly (P <.001) with benign and
malignant tumors. Early enhancement was seen in chondrosarcoma, not seen in
enchondroma, and seen in osteochondroma only when growth plates were unfused. The
sensitivity was 89%, specificity 84%, positive predictive value 84%, and negative
predictive value 89%. Differentiation of malignancy from benignity on the basis
of early and exponential enhancement was possible with a sensitivity of 61%,
specificity 95%, positive predictive value 92%, and negative predictive value
72%. CONCLUSION: Preliminary results show that in the adult population fast
contrast-enhanced MR imaging may assist in differentiation between benign and
malignant cartilaginous tumors.
PMID- 10671609
TI - Rates and correlates of discomfort associated with mammography.
AB - PURPOSE: To explore the rates and correlates of discomfort at mammography in
asymptomatic women aged 50-74 years from six San Diego, Calif, mammography
facilities. MATERIALS AND METHODS: Subjects (N = 1,800) completed a 43-item
telephone interview approximately 3 weeks after screening mammography. Bivariate
associations between variables were analyzed with chi(2) analysis. Logistic
regression was used to assess the independent predictors of discomfort at
mammography while controlling for all other factors. RESULTS: Nine hundred thirty
three (52%) women reported moderate to extreme discomfort at mammography.
Discomfort was not related to the intention to undergo future mammography (P
=.95). Factors that were significantly associated with discomfort in multivariate
analyses were facility (P <.001), satisfaction with care (P <.04), and perception
of the technologist's "roughness" (P <.001). CONCLUSION: Discomfort, although not
related to the intention to undergo future mammography, had a relatively high
incidence.
PMID- 10671610
TI - Gynecomastoid hyperplasia: imaging findings in six patients.
AB - This case series describes the radiologic appearances of gynecomastoid
hyperplasia of the breast in our experience. The clinical histories, breast
images, and histopathologic findings in six women were reviewed. At mammography,
there was no abnormality in two women, an enlarging asymmetric density in three
women, and a nodule in one woman. Breast ultrasonography showed a hypoechoic
nodule in one woman. Gynecomastoid hyperplasia has a varied radiologic
appearance.
PMID- 10671611
TI - Bovine type I collagen as an endovascular stent-graft material: biocompatibility
study in rabbits.
AB - PURPOSE: To study the biocompatibility of a bovine type I collagen preparation as
a material for small-vessel stent-grafts in rabbits. MATERIALS AND METHODS: A
composite nitinol-collagen endovascular stent-graft with a 4-mm inner diameter
was deployed in the abdominal aorta in nine rabbits. Angiography was performed,
and the rabbits were sacrificed at 1, 2, and 7 days and at 1 and 3 months. The
portion of the aorta containing the stent-graft was excised and was
histologically evaluated. RESULTS: All stent-grafts were patent at all time
points. On days 1, 2, and 7 after implantation, scattered red and white blood
cells adhered to the stent-graft. At 1 month, the stent-graft was endothelialized
and was infiltrated with fibroblasts that deposited collagen within the
interstices of the implanted collagen material. At 3 months, there was additional
collagen deposition within the interstices of the stent-graft that did not narrow
the lumen of the stent-grafts. CONCLUSION: Type I collagen as a intravascular
stent-graft material is biocompatible for at least 3 months in rabbits. It is
rapidly endothelialized and does not cause reactive stenosis. As a versatile and
biocompatible polymer, collagen is potentially useful in the construction of
endovascular stent-grafts for use in human arteries.
PMID- 10671612
TI - Effect of barium sulfate on wound healing in the gastrointestinal tract of the
rat.
AB - PURPOSE: To study the effect of barium sulfate on wound healing in the
gastrointestinal tract of the rat. MATERIALS AND METHODS: Sixty rats weighing
approximately 320 g were divided into four groups: Fifteen control rats had
gastric, small-bowel, and colonic incisions; 15 rats had gastric incision; 15
rats had small-bowel incision; and 15 rats had colonic incision. Barium sulfate
was placed into the incision before closure in all rats except those in the
control group, and the effects were documented clinically and histopathologically
for 3 months. Autopsy was performed in five rats from each group at 1, 4, and 12
weeks. The incisions in the rats receiving barium sulfate were compared with
those in the control rats. RESULTS: There was no difference in the clinical
course (weight gain, activity, and viability) between the control and
experimental groups. Early and late autopsy findings and histopathologic grading
of healing and inflammatory response were similar for both the control and
experimental groups. CONCLUSION: Under the conditions of this study, the effect
of barium sulfate on visceral transmural wound healing in the gastrointestinal
tract of the rat was minimal.
PMID- 10671613
TI - Tumoral distribution of long-circulating dextran-coated iron oxide nanoparticles
in a rodent model.
AB - PURPOSE: To investigate the accumulation and cellular uptake of long-circulating
dextran-coated iron oxide (LCDIO) particles in malignant neoplasms in vivo.
MATERIALS AND METHODS: A gliosarcoma rodent model was established to determine
the distribution of a model LCDIO preparation in tumors. LCDIO accumulation in
tissue sections was evaluated with multichannel fluorescence microscopy with
rhodaminated LCDIO, green fluorescent protein as a tumor marker, and Hoechst
33258 dye as an intravital endothelial stain. Uptake into tumor cells was
corroborated with results of immunohistochemical and cell culture uptake
experiments. The effect of intratumoral LCDIO uptake on magnetic resonance (MR)
imaging signal intensity was evaluated with a 1.5-T superconducting magnet.
RESULTS: Tumoral accumulation of LCDIO was 0.11% +/- 0.06 of the injected dose
per gram of tissue in brain tumors and was sufficient for detection at MR
imaging. In tumor sections, LCDIO was preferentially localized in tumor cells
(49.0% +/- 4.6) but was also taken up by macrophages in tumors (21.0% +/- 3.1)
and by endothelial cells in the areas of active angiogenesis (6.5% +/- 1.4). In
cell culture, LCDIO uptake was strongly correlated with growth rate of tumor cell
lines. CONCLUSION: Tumoral LCDIO accumulation was not negligible and helped
explain MR imaging signal intensity changes observed in clinical trials.
Microscopically, LCDIO accumulated predominantly in tumor cells and tumor
associated macrophages. Uptake into tumor cells appeared to be directly
proportional to cellular proliferation rates.
PMID- 10671614
TI - Optimal section spacing in single-detector helical CT.
AB - To define the section spacing that maximizes longitudinal resolution without
needless section overlap, the optimal percentage of overlap was computed
theoretically and expressed as a constant relative to the effective section
thickness. For imaging applications that require maximal longitudinal resolution,
single-detector helical computed tomographic images should be reconstructed with
at least 60% overlap relative to the effective section thickness.
PMID- 10671615
TI - US with extended field of view: phantom-tested accuracy of distance measurements.
AB - To evaluate the accuracy of distance measurements obtained with the extended
field-of-view (FOV) software of a commercially available ultrasonographic
scanner, two custom-designed phantoms that allowed scanning of flat and curved
surfaces were used. Five hundred forty measurements of various known distances in
the phantoms were made by three examiners using various transducers. Although
minor differences were observed between operators and transducers, 99.4% (537 of
540) of the distance measurements were accurate within plus or minus 4%. This
extended-FOV technology provides accurate measurements of large objects in vitro.
PMID- 10671616
TI - Lesions entirely removed during stereotactic biopsy: preoperative localization on
the basis of mammographic landmarks and feasibility of freehand technique-
initial experience.
AB - Seven patients with mammographic lesions entirely removed at percutaneous core
needle biopsy that required wider excision underwent freehand localization of the
site of the prior lesion with orthogonal and reproducible mammographic landmarks
to guide needle placement. Successful excision was accomplished in all cases, as
evidenced by similar histopathologic findings, fibrin bands or collagen, and core
needle biopsy tract at microscopy.
PMID- 10671617
TI - Head and neck tumors: fractionated frameless stereotactic interstitial
brachytherapy-initial experience.
AB - The authors used a frameless stereotactic navigation system, the Vogele-Bale
Hohner head holder, and a targeting device to reproducibly position brachytherapy
needles for fractionated interstitial brachytherapy in 12 patients with
inoperable cancers of the head and neck. In all cases, deviations of the needle
relative to the planned position were within 1-15 mm depending on the location of
the tumor.
PMID- 10671618
TI - Helical CT cholangiography with oral cholecystographic contrast material.
AB - Twenty asymptomatic volunteers underwent helical computed tomographic (CT)
cholangiography 10-12 hours after ingesting iopanoic acid. Three observers
assessed the images for the extent of bile duct visualization and image quality.
The common bile duct and common hepatic duct were adequately visualized in 19
(95%) subjects. Helical CT cholangiography with oral cholecystographic contrast
material is feasible and deserves further clinical studies.
PMID- 10671619
TI - Potential hazards in the use of tungsten mechanical detachable coils.
PMID- 10671620
TI - Proper CT viewing.
PMID- 10671621
TI - Compression of the celiac trunk by the median arcuate ligament.
PMID- 10671622
TI - Crescent sign origin and the thrombus-to-lumen ratio in abdominal aortic
aneurysm.
PMID- 10671623
TI - Guide wire-assisted placement of non-end-hole nasoenteric feeding tubes.
PMID- 10671624
TI - Abstracts of current literature
PMID- 10671625
TI - Renal nutrition in the new millennium.
PMID- 10671626
TI - Further analysis in renal nutrition.
PMID- 10671627
TI - The best way to manage hypertension after renal transplantation.
AB - Hypertension in renal allograft recipients is a common problem arising from
multiple factors, including peripheral vascular damage caused by pretransplant
hypertension, side effects of immunosuppressive medications, allograft
dysfunction, renal artery stenosis, recurrent glomerulonephritis, synthesis of
vasoconstrictive hormones by the native kidneys, and excessive dietary salt
intake. Identification of modifiable factors causing hypertension and concurrent
medical conditions, and measurement of glomerular filtration rate,
cyclosporine/tacrolimus blood levels, and magnitude of proteinuria are essential
to tailor treatment for an individual patient. Lifestyles that exacerbate
hypertension should be modified. For pharmacological therapy, diuretics and
calcium channel blockers are first-line agents in patients on cyclosporine
shortly after transplant. Angiotensin-converting enzyme inhibitors are good
choices for patients with significant proteinuria. Reduction of immunosuppression
will improve hypertension in some patients, but entails a potential risk of
rejection or graft loss. Angioplasty is necessary in patients with a functionally
significant stenosis of the allograft renal artery. Other patients on maximal
medical therapy may benefit from native nephrectomy.
PMID- 10671628
TI - Protein-energy malnutrition as a risk factor for increased morbidity in long-term
hemodialysis patients.
AB - This prospective nonintervention single-center study was undertaken to
investigate the role of protein-energy malnutrition (PEM) as a risk factor for
morbidity in patients on long-term hemodialysis. Thirty-seven patients from the
renal unit of Tygerberg Hospital, Tygerberg, South Africa, were studied for a
mean period of 26 months. Morbidity was the main outcome and was defined as the
number of hospitalizations and days of hospitalization per patient per year.
Investigations included 4-monthly determinations of interdialytic protein
catabolic rate (PCR), dietary intake of protein and energy, blood levels of
albumin and urea, lymphocyte count, adequacy of dialysis (Kt/V), body weight,
intradialytic weight loss, fat mass (FM), fat-free mass (FFM), body mass index
(BMI), and bone-free arm muscle area (BF-AMA). A PEM composite score was derived
from postdialysis serum albumin, BF-AMA, FM, FFM, and BMI. All-cause morbidity as
defined by number of hospitalizations (see text for other definitions of
morbidity) showed a significant correlation with the mean and baseline PEM score
(P <.01), and a negative correlation with predialysis and postdialysis serum
albumin (P <.05) and age (P <.05). There was no significant relationship with
PCR, percentage intradialytic weight loss, Kt/V, reuse of dialyzer, period on
maintenance hemodialysis, sex, race, and type of dialyzer membrane. When "only
infection-related" morbidity was considered, the factors that showed a
significant correlation were the mean (P <. 001) and baseline PEM score (P <.01),
and percentage intradialytic weight loss (P <.01). There was no significant
deterioration in the nutritional status of patients followed up for at least 24
months. It is concluded that infection-related morbidity was associated most
strongly with the PEM score and the percentage intradialytic weight loss. The
results suggest that PEM is one of the important contributing factors to
morbidity, possibly via an effect on the immune system and infection.
PMID- 10671629
TI - Selenate-supplemented nutritional formula increases plasma selenium in
hemodialysis patients.
AB - OBJECTIVE: The purpose of this study was to determine the short-term effect of
feeding selenium-supplemented formulas on the selenium status of end-stage renal
disease patients on hemodialysis. DESIGN AND SETTING: The prospective,
randomized, single-blind study of parallel design was conducted at three
hemodialysis clinics. PATIENTS: A total of 79 hemodialysis patients were randomly
assigned into one of three groups. INTERVENTION: Liquid nutritional formula
supplemented with either selenite (28 microg Se/8 oz, n = 26), selenate (28
microg Se/8 oz, n = 26), or nonfortified (7 microg Se/8 oz, n = 27) was fed to
hemodialysis patients as their sole source of nutrition for 14 days. MAIN OUTCOME
MEASURE: Plasma and red blood cell (RBC) selenium and glutathione peroxidase
(GPX) activities were measured in predialysis blood both before (day 1) and after
(day 8) a 7-day baseline period, and after subjects received the formula as the
sole source of nutrition (approximately 35 kcal/kg/d) for 14 days (day 22).
RESULTS: Selenium intake (Mean +/- SEM, microg/d) was 134 +/- 9, 140 +/- 9, and
35 +/- 2 for patients receiving selenite-, selenate-, or non-supplemented
formula, respectively. On day 22, plasma selenium (micromol/L) was greater (P
<.032) in the selenate-supplemented group (1.5 +/- 0.1) compared with the
nonsupplemented group (1.2 +/- 0.1), but not compared with the selenite
supplemented group (1.4 +/- 0.1). Plasma GPX activity was 44% to 60% that of
healthy controls and not different among groups. RBC selenium and GPX activities
were within the normal range and were not different among groups. CONCLUSION: The
results of this study indicate that a liquid formula supplemented with selenium
as selenate is successful at maintaining selenium concentrations within normal
range, as well as significantly increasing plasma selenium levels compared with
nonsupplementation.
PMID- 10671630
TI - Oral vitamin intake in children receiving long-term dialysis.
AB - OBJECTIVE: To evaluate dietary and oral supplement vitamin intake in children
submitted to dialysis (peritoneal dialysis and hemodialysis). DESIGN: Prospective
clinical trial in a 12-month follow-up period. SETTING: Children with end-stage
renal disease (ESRD) who attended the pediatric nephrology clinic of Universidade
Federal de Sao Paulo-Escola Paulista de Medicina (UNIFESP-EPM), Sao Paulo,
Brazil. PATIENTS: Thirty children (18 girls, 23 in peritoneal dialysis, 7 in
hemodialysis) with age 9.3 +/- 7.4 years. INTERVENTION METHODOLOGY: Six
successive assessments of both anthropometric indexes and 3-day dietary diaries
in children receiving a daily dose of oral water-soluble vitamin supplement. MAIN
OUTCOME MEASURES: Anthropometric indexes (weight/age [W/A], height/age [H/A],
midarm muscle area/age [MAMA/A], and fat area/age [FA/A]) and dietary adequacy-%
recommended dietary allowance (RDA) (computerized nutritional analysis from 3-day
dietary intake diary). RESULTS: Anthropometric indexes analysis showed that 53%
of children were <-2.0 standard deviation score (SDS) of W/A, 63% were <-2.0 SDS
of H/A, and 43.3% were <-1.65 SDS of MAMA/A, suggesting growth deficit and low
muscle wasted. Total caloric intake was lower than 100% of RDA in 90% of
children. Dietary intake of water-soluble vitamins was <100% of RDA in the
majority of children, as follows: vitamin C (24/30), B1 (28/30), B2 (22/30), B3
(27/30), B6 (26/30), B12 (1/30), pantothenic acid (24/30), and folic acid (9/30).
The combined dietary and vitamin supplement intake resulted in excessive oral
intake for almost all the vitamins. CONCLUSION: Dietary intake of water-soluble
vitamins is lower than the RDA in the majority of children with ESRD;
supplementation is necessary to reach the RDA. The use of the available vitamin
supplement resulted in vitamin intakes that exceeded the RDA for almost all of
the vitamins. However, we do not know if these intakes exceeded the children's
requirements, nor whether they had any clinically significant harmful effects.
PMID- 10671631
TI - Can low-fat/cholesterol nutrition counseling improve food intake habits and
hyperlipidemia of renal transplant patients?
AB - OBJECTIVE: To assess the impact of low-fat/cholesterol nutrition counseling on
food intake habits and blood lipid levels of renal transplant patients. DESIGN:
Prospective practice-based outcome study. SETTING: Acute care hospital post-renal
transplant outpatient clinic. PATIENTS: Forty-three renal transplant patients not
on lipid-lowering medications referred to the renal dietitian for low
fat/cholesterol nutrition counseling between September 1994 and September 1997.
INTERVENTION: Individual assessment and counseling using the Healthy Heart
Nutrition Guidelines Step 1 diet (<30% of total calories from fat, <300 mg
cholesterol, and <10% of total calories from saturated fatty acids). MAIN OUTCOME
MEASURES: Three-day food records precounseling and 3-day food records (n = 13) or
descriptive intake changes (n = 30) postcounseling (time interval: 2 to 8
months). Fasting/random serum total cholesterol, high-density lipoprotein
cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C), as
available. RESULTS: Total cholesterol (n = 43) and LDL-C (n = 22) decreased
significantly (0. 54 mmol/L P <.000 and 0.53 mmol/L P <.000, respectively). There
were no significant changes in HDL-C and triglycerides. Twenty percent of
patients (n = 43) reached target levels of total cholesterol <5.2 mmol/L, and 35%
of patients (n = 22) reached target levels of LDL-C <3.4 mmol/L. Percentage of
total calories from fat decreased significantly (7.58% P <.03). Descriptive
intake changes of lower fat choices were reported in the no post-food records
group. CONCLUSION: Patients can make changes in food intake habits after
nutrition counseling. Serum lipid levels can improve after nutrition counseling,
but many patients may still require lipid lowering medications to reach target
levels. Nutrition counseling should be considered for the initial treatment of
hyperlipidemia in renal transplant patients.
PMID- 10671632
TI - The effects of megestrol acetate on nutritional parameters in a dialysis
population.
AB - OBJECTIVE: To examine the effect of megestrol acetate on nutritional parameters
in a hemodialysis population. DESIGN: Prospective case studies of hemodialysis
patients. SETTING: A freestanding, nonprofit, hemodialysis unit. SUBJECTS:
Seventeen patients were studied. They were included regardless of gender, age, or
cause of renal disease. They had to be on dialysis for at least 2 months, had a
serum albumin <3.5 g/dL for these 2 months, and had to be at high nutritional
risk. There were 8 women and 9 men. Ages were 44 to 87 years. Eight were
diabetics, and 9 were nondiabetics. INTERVENTIONS: Megestrol acetate 400 mg
orally twice daily was prescribed, and patients were studied for 6 months.
OUTCOME MEASURES: Pre-evaluation and postevaluation were performed by patient
questionnaire, Subjective Global Assessment (SGA), dry weight, and anthropometric
measurements. Monthly laboratory monitoring included albumin, prealbumin, blood
urea nitrogen (BUN), cholesterol, triglycerides, carbon dioxide, platelets,
hematocrit, alanine aminotransferase (ALT), aspartate aminotransferase (AST),
gammaglutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), alkaline
phosphatase, and glucose. Glycohemoglobin and hemoglobin A1c were monitored in
diabetic patients. RESULTS: Three patients were able to take megestrol acetate
for 5 to 6 months. They reported improved appetite and showed an increase in dry
weight. The annualized mortality rate was about 59%. Side effects included
diarrhea, confusion, hyperglycemia, headaches, dizziness, and elevated LDH.
CONCLUSION: Megestrol acetate may help stimulate appetite in the hemodialysis
patient, but it is risky and must be monitored closely. Eight hundred milligrams
per day is probably too large a dose for the end-stage renal disease (ESRD)
patient.
PMID- 10671633
TI - Computers and the Internet: tools for lifelong learning.
AB - Mastery of computer technology and the resources it brings to renal dietitians
will be essential for future practice. The Internet, probably the most valuable
resource computers bring to clinical practice, is a potential tool to fulfill
goals of lifelong learning. A basic introduction to the Internet and a review of
search engines and successful search strategies are provided. Major flaws of the
Internet include uncertain quality and accuracy of many materials it provides.
Guidelines to evaluate World Wide Web (WWW) materials are similar to guidelines
dietitians use to assess written materials. The identification of certain anchor
WWW sites with reliable information is a key to successful information retrieval
on the Internet.
PMID- 10671635
TI - Message from the chairperson
PMID- 10671634
TI - Grocery list for people on hemodialysis! (Food your patients CAN eat).
PMID- 10671636
TI - Duplicated regions of AF-4 intron 4 at t(4;11) translocation breakpoints.
AB - BACKGROUND: AF-4 is a common partner gene of MLL. AF-4 breakpoints occur in
introns, but most AF-4 introns are uncharacterized. METHODS AND RESULTS: We
cloned AF-4 intron 4 and examined the frequency of breakpoints in this intron.
The 5.8-kb intron is rich in repeat sequences and was the site of translocation
in 3 of 17 leukemias with t(4;11). We cloned the der (11) and der (4) breakpoints
and isolated the fusion transcripts in the cell line MV4-11 and in a de novo
acute lymphoblastic leukemia (ALL). Both translocations joined MLL intron 6 and
AF-4 intron 4. In MV4-11, 249 bases from AF-4 were present in both derivative
chromosomes, indicating duplication. In the de novo ALL, duplication of 446 bases
from MLL and AF-4 occurred. Reciprocal fusion transcripts were expressed.
CONCLUSIONS: Intronic sequence of AF-4 is useful for molecular diagnosis of
t(4;11). Duplicated intronic regions suggest staggered chromosomal breakage.
PMID- 10671638
TI - Pharmacogenetics becomes pharmacogenomics: wake up and get ready.
PMID- 10671637
TI - Improved detection of human immunodeficiency virus type 1 variants by analysis of
replicate amplification reactions: relevance to studies of human immunodeficiency
virus type 1 vertical transmission.
AB - BACKGROUND: Human immunodeficiency virus type 1 (HIV-1)-infected individuals
typically harbor mixtures of HIV-1 variants. For HIV-1 transmission studies,
methods used for genotypic analysis should reliably detect variant mixtures. Such
studies typically analyze complementary DNAs (cDNAs) from a single polymerase
chain reaction (PCR) amplification. This approach may fail to detect variant
mixtures in some samples because of analytic bias. METHODS: To evaluate the
impact of analytic bias on the detection of HIV-1 variants, we analyzed samples
from a mother and infant known to contain both subtypes A and D HIV-1. The env
third variable region of HIV-1 gp120 (V3 region) was amplified and cloned in five
replicate experiments using a single plasma sample from each individual. Ten
cDNAs from each experiment were analyzed. RESULTS: The subtype mixture was
detected in only four of 10 amplification experiments (three of five for the
mother and one of five for the infant). Sequencing of uncloned PCR products
showed that a single subtype, either A or D, was preferentially amplified in each
experiment. However, the subtype mixture was detected for each sample by
analyzing the five replicate experiments as a group. CONCLUSIONS: This shows that
mixtures of HIV-1 variants may be more readily detected when replicate
amplification reactions are analyzed. This approach may be useful for
characterizing HIV-1 variants for studies of HIV-1 transmission.
PMID- 10671639
TI - Impact of pharmacogenomics on the clinical laboratory.
AB - Clinical pharmacogenomics promises to increase the safety and efficacy of drug
prescription, decrease the incidence of adverse drug reactions, help improve
public health, and presage in an era of personalized, predictive, and
prophylactic medicine. Clinical pharmacogenomics stands to be broad based and
include the following laboratory components: new and expanded pharmacogenetic
tests, disease profiles, chemopredictive testing, and risk profiling. There is a
growing body of evidence that variable drug responsiveness is caused by
polymorphisms within multiple genes, protein products of which are involved in
critical metabolic and/or physiologic pathways relevant for drug action.
Different pharmacogenomic approaches will be used to discover a new generation of
unique and highly predictive pharmacogenetic tests that the clinical laboratory
will employ to help identify patient responder populations. Disease profiling and
chemopredictive testing will routinely be applied to accurately screen for
disease and help guide therapeutic course of action. A growing number of risk
profiling tests will assist in predicting a patient's predisposition to disease.
Clinical pharmacogenomics stands to become the basis for the new millennium's
practice of medicine and have a profound impact on the clinical laboratory.
PMID- 10671640
TI - Populations and genetic polymorphisms.
AB - BACKGROUND: Population frequencies of many polymorphic genes of pharmacogenetic
interest depend on race or ethnic specificity. Association of these genes with
person-to-person differences in drug effectiveness (hypersensitivity or
resistance) and drug toxicity may also depend on the racial or ethnic
characteristics of a population. Information about ethnic specificity is an
integral part of pharmacogenetics because it can suggest a starting point for
further study of these traits, tailoring drug therapy to the individual patient,
and rational development and clinical trials of new drugs. Ethnic specificities
of several medically important metabolic traits serve to illustrate these ideas.
Among the traits considered is primaquine sensitivity, a sex-linked trait
attributed to glucose-6-phosphate dehydrogenase deficiency that mainly affects
males among African, Mediterranean, and Oriental people. Additional examples
include the remarkable sensitivity of the Japanese to alcohol (ethanol) compared
with whites; the ethnic specificity of the cytochrome P-450 enzyme CYP2D6*
(debrisoquine/sparteine) polymorphism that results in poor, extensive, and
ultrarapid metabolizers of at least 30 drugs; the CYP2C19* (mephenytoin)
polymorphism that accounts for variable metabolism of proguanil, omeprazole, and
certain barbiturates; and the polymorphic (NAT2*) acetylation of hydrazine and
aromatic amine drugs, such as isoniazid, hydralazine, and sulfasalazine.
PMID- 10671641
TI - Single-nucleotide polymorphisms, haplotypes, and their relevance to
pharmacogenetics.
AB - Recognition that there is a vast quantity of human genetic variation has had a
pervasive impact on modern medicine, facilitating the identification of scores of
genes that underlie monogenic clinical disorders, as well as genes involved in
complex disease processes. The next logical step for human genetics is the
exploration and elucidation of genes involved in differential pharmacological
response: responders, nonresponders, and those with adverse side effects. An
understanding of the role that genes have in pharmacological response is the
cornerstone of personalized medicine. Pharmacogenetic activities have swiftly
embraced these tenets, leading to a proliferation of resources and approaches
meant to enable and expedite targeted drug discovery and development. To realize
the potential of these efforts, it will be necessary to incorporate a better
understanding of the population genetic and evolutionary processes that have
shaped genetic variation in modern humans. This article introduces these concepts
to provide context and guidelines for the use of this variation (primarily single
nucleotide polymorphisms and haplotypes) in pharmacogenetics.
PMID- 10671642
TI - Mining the Swedish clinical archives to develop pharmacogenomic tests.
AB - Eurona Medical is a Swedish company that develops diagnostic tests to predict
response to drugs or treatment. Sweden offers unparalleled retrospective clinical
data resources, with epidemiological registers and collections of tissue samples
built up over decades. Efficient pharmacogenomic research can be performed using
these registers and sample collections in collaboration with experienced medical
researchers. Eurona's tests are based on Genetic Signatures, groups of
polymorphic, polygenic genomic positions linked to and therefore predictive of
drug response. These are elucidated from complex data sets using unique
applications of multivariate and combinatorial statistics and a multigenic
approach. The company develops tests applicable to current medical practice and
is preparing to launch its first within the hypertension field. Quality control
(including ISO9001 certification) and clinical regulatory compliance are applied
throughout all programs to produce data that can be directly translated into
clinical tests.
PMID- 10671643
TI - Inherited variations in drug-metabolizing enzymes: significance in clinical
oncology.
AB - Pharmacogenetics has emerged as a novel and challenging area of interest in
oncology. Cancer chemotherapy is characterized by major intersubject variability
in tumor responses and host toxicity. This variation may be caused by genetic
differences in the enzymes involved in the metabolism of anticancer agents.
Anticancer agents, such as 6-mercaptopurine, 5-fluorouracil, and irinotecan, have
a narrow therapeutic index that can sometimes result in severe life-threatening
toxicities. The impact of polymorphisms in metabolizing enzymes (thiopurine S
methyltransferase, dihydropyrimidine dehydrogenase, and uridine diphosphate
glucuronosyltransferase) that participate significantly in the disposition of
these anticancer agents is discussed.
PMID- 10671644
TI - Apolipoprotein E: a pharmacogenetic target for the treatment of Alzheimer's
disease.
AB - BACKGROUND: The discovery that the apolipoprotein E4 (apoE4) allele is strongly
linked to both sporadic and familial late-onset Alzheimer's disease (AD) raises
the possibility that a dysfunction of the lipid transport system could seriously
affect lipid homeostasis in the brain. We recently proposed that the abnormally
low concentrations of apoE observed in the brains of apoE4 AD subjects could
compromise cholesterol, fatty acid, and phospholipid transport in the central
nervous system. This, in turn, would indirectly impair the cholinergic system,
which, in contrast to other neurotransmitters in the central nervous system,
relies heavily on lipids to synthesize acetylcholine. Several independent
investigators have now confirmed the original observation of an inverse
relationship between apoE4 allele copy number and residual brain choline
acetyltransferase activity and nicotinic-receptor binding sites in the brains of
subjects with AD. More importantly, it has been shown that the presence of the
apoE4 allele differentially affects the quality and size of drug responsiveness
in subjects with AD treated with cholinomimetic and noncholinomimetic agents. We
also examine the role of apoE as a potent therapeutic target for AD.
PMID- 10671645
TI - Technologies for detecting genetic polymorphisms in pharmacogenomics.
AB - BACKGROUND: Pharmacogenomics is an emerging scientific discipline examining the
genetic basis for individual variations in response to therapeutics. METHODS AND
RESULTS: Genetic polymorphisms are a major cause of individual differences in
drug response. Metabolic phenotyping can be accomplished by administering a probe
drug or substrate and measuring the metabolites and clinical outcomes. However,
this approach tends to be labor intensive and requires repeated sample collection
from the individual being tested. Alternatively, genotyping allows determination
of individual DNA sequence differences for a particular trait. Commonly used
genotyping methods include gel electrophoresis-based techniques, such as
polymerase chain reaction (PCR) coupled with restriction fragment length
polymorphism analysis, multiplex PCR, and allele-specific amplification.
Fluorescent dye-based high-throughput genotyping procedures are increasing in
popularity, including oligonucleotide ligation assay, direct heterozygote
sequencing, and TaqMan (Perkin Elmer, Foster City, CA) allelic discrimination.
High-density chip array and mass spectrometry technologies are the newest
advances in the genotyping field, but their wide application is yet to be
developed. Novel mutations/polymorphisms also can be identified by conformation
based mutation screening and direct high-throughput heterozygote sequencing.
CONCLUSIONS: Rapid and accurate detection of genetic polymorphisms has great
potential for application to drug development, animal toxicity studies,
improvement of human clinical trials, and postmarket monitoring surveillance for
drug efficacy and toxicity.
PMID- 10671646
TI - Clinical, genetic, and pharmacogenetic applications of the Invader assay.
AB - The Invader technology has been developed for the detection of nucleic acids. It
is a signal amplification system able to accurately quantify DNA and RNA targets
with high sensitivity. Exquisite specificity is achieved by combining
hybridization with enzyme recognition, which provides the ability to discriminate
mutant from wild-type at ratios greater than 1/1000 (mutant/wt). The technology
is isothermal and flexible and incorporates a homogeneous fluorescence readout.
It is therefore readily adaptable for use in clinical reference laboratories, as
well as high-throughput applications using 96-, 384-, and 1,536-well microtiter
plate formats. The molecular mechanism of the system and specific applications
for use in clinical and research laboratories are described. These include direct
analysis of unamplified human genomic DNA to detect mutations and single
nucleotide polymorphisms associated with factor V Leiden, factor II, cystic
fibrosis, and apolipoprotein E, and gene expression assays that quantify
messenger RNA levels in cells using direct lysates.
PMID- 10671647
TI - Pharmacogenetics in the practice of laboratory medicine.
AB - BACKGROUND: The clinical laboratory forms an essential bridge between fundamental
discoveries in biological sciences and their transition into effective medical
practice. The genetic basis for individuality in drug metabolism and response is
the result of a finite number of inherited sequence variants (alleles) of genes
encoding drug-metabolizing enzymes and drug receptors. Pharmacogenetics (PG)
links differences in gene structure with pharmacological differences in
pharmacokinetics and pharmacodynamics. The next step in the process of applying
PG (or pharmacogenomic) information to individualized therapeutic management is
dissemination of this information to practicing physicians by clinical
laboratorians. Transitioning PG analysis into clinical practice will require
professionals in laboratory medicine to identify relevant polymorphisms, develop
sensitive and specific testing strategies, and, in conjunction with physicians
and pharmacologists, communicate interpretive guidelines regarding appropriate
indications for testing and rational dose adjustment. We review these concepts
and provide examples of how PG can be applied to support therapeutic decision
making.
PMID- 10671648
TI - The use of aptamers in large arrays for molecular diagnostics.
AB - BACKGROUND: Aptamers are single-stranded oligonucleotides derived from an in
vitro evolution protocol called systematic evolution of ligands by exponential
enrichment (SELEX). They bind tightly and specifically to target molecules; most
aptamers to proteins bind with Kds (equilibrium dissociation constant) in the
range of 1 pM to 1 nM. METHODS AND RESULTS: The SELEX protocol has been
automated; therefore, hundreds to thousands of aptamers can be made in an
economically feasible fashion. Blood and urine can be analyzed on chips that
capture and quantitate proteins. SELEX has been adapted to the use of 5-bromo (5
Br) and 5-iodo (5-I) deoxyuridine residues. These halogenated bases can be
specifically cross-linked to proteins. Selection pressure during in vitro
evolution can be applied for both binding specificity and specific photo-cross
linkability. These are sufficiently independent parameters to allow one reagent,
a photo-cross-linkable aptamer, to substitute for two reagents, the capture
antibody and the detection antibody, in a typical sandwich array. After a cycle
of binding, washing, cross-linking, and detergent washing, proteins will be
specifically and covalently linked to their cognate aptamers. CONCLUSIONS:
Because no other proteins are present on the chips, protein-specific stain will
now show a meaningful array of pixels on the chip. Learning algorithms and
retrospective studies should lead to a robust, simple, diagnostic chip.
PMID- 10671649
TI - Whither the chips may fall?
PMID- 10671650
TI - Overestimation of HFE C282Y homozygous hemochromatosis prevalence as the result
of a common primer-binding site polymorphism.
PMID- 10671651
TI - Gynecologic cancer: evolving management issues. Introduction.
PMID- 10671652
TI - Complete surgical staging of early endometrial adenocarcinoma: optimizing patient
outcomes.
AB - Endometrial adenocarcinoma is the most common gynecologic malignancy. Strategies
for treatment of this disease should not only emphasize quality of care resulting
in cure of disease, but also use health care resources in the most efficient
manner possible. Based on available data, we recommend that all patients with the
diagnosis of endometrial carcinoma undergo complete surgical staging with lymph
node dissection. Radiation therapy is reserved only for patients with evidence of
extrauterine disease. This approach maximizes the amount of information available
for treatment planning and offers the potential therapeutic advantage of lymph
node dissection. Additionally, in a cost analysis, this approach appears to be
the most cost-effective.
PMID- 10671653
TI - Complete surgical staging in endometrial cancer provides prognostic information
only.
AB - Endometrial cancer is the most common gynecologic malignancy in the United
States. Surgical resection provides the best chance for cure and guides the
potential need for adjuvant therapy. Controversy exists regarding the extent of
surgical staging, in particular, the necessity and rationale for removing or
sampling the draining lymphatics. An emerging practice in the United States is to
perform more aggressive lymph node dissections. The data indicate that surgical
staging provides prognostic information only and may indirectly influence
survival only through guiding adjuvant therapy.
PMID- 10671654
TI - The role of radiotherapy for high-risk endometrial cancer.
AB - High-risk endometrial cancer comprises an uncommon group of tumors, which
includes pathological stage III adenocarcinoma and all stages of papillary serous
carcinoma. Optimal management of this class of malignant female genital neoplasms
is surgical resection, including debulking of any gross abdominopelvic disease.
This article analyzes the literature concerning the use of adjunctive
radiotherapy. The data presented suggest that postoperative whole abdominal
radiotherapy may improve outcome in selected subsets of patients within this high
risk group. Future clinical investigations will greatly benefit from the
anticipated published results of two completed prospective cooperative group
clinical trials that involve whole abdominal irradiation.
PMID- 10671655
TI - Adjuvant chemotherapy for high-risk endometrial cancer.
AB - Identification of histopathologic factors that predict the risk of tumor
recurrence allows for selection of women with endometrial cancer who might
benefit from adjuvant therapy. Most studies of adjuvant treatment have focused on
external-beam irradiation or oral progestational agents and have failed to
document a survival advantage for treated patients. Although recurrent or
metastatic endometrial tumors often respond to salvage treatment with cytotoxic
agents, there is relatively little experience with postoperative systemic
chemotherapy used in an adjuvant setting. A few nonrandomized trials-using
doxorubicin/platinum-based regimens-have suggested that adjuvant chemotherapy may
be beneficial in some patient subsets. Data from larger-scale, randomized trials
do not exist. Additional clinical experience is needed before a definite role for
adjuvant chemotherapy can be established.
PMID- 10671656
TI - Tailoring radiation to the extent of disease for uterine-confined endometrial
cancer.
AB - More than 50 years ago, endometrial cancer was found to be sensitive to
radiation, and adjuvant radiation was observed to decrease the incidence of
pelvic recurrences. Over the last 2 decades, substantial progress has been made
in the understanding of prognostic factors for survival and patterns of disease
recurrence for patients with endometrial cancer. Few randomized trials have been
done because of the relatively few patients who are at risk of recurrence and the
strong bias of many oncologists toward the use of adjuvant radiation. Principles
guiding treatment recommendations are based predominately on retrospective
publications containing variance in pathological evaluation, surgical evaluation,
and patient selection. Preliminary analysis of a randomized Gynecologic Oncology
Group trial is reviewed. Optimal therapy for many patients remains to be better
defined.
PMID- 10671657
TI - Optimizing radiation parameters for cervical cancer.
AB - The treatment of cervical cancer has become increasingly sophisticated with
evidence-based guidelines generated from randomized trials directing combined
modality programs. The radiotherapeutic guidelines have been derived largely from
single institutional experiences coupled with data from the Patterns of Care
Studies. The design of external-beam fields has improved because of a better
understanding of the anatomy of the cervix, uterus, parametrium, and draining
lymph nodes from surgical, lymphangiogram, computed tomography scan, and magnetic
resonance imaging series. An improvement in survival and local control with dose
intensity (a reduction in overall treatment time and increase in overall dose)
has been shown for cervical cancer, especially for locally advanced disease, and
these series are highlighted. The use of intracavitary radiation, which is
technically accurate, dramatically improves outcome and allows for dose
intensity. Alternative brachytherapy techniques, such as high-dose-rate, and
interstitial, are discussed. Ways to improve the therapeutic ratio for radiation,
including biological factors, are reviewed. More research is necessary to
understand the complex dose distribution of external-beam and intracavitary
brachytherapy and its relationship to tumor control.
PMID- 10671658
TI - Concurrent chemotherapy and radiation for locally advanced cervical cancer: the
new standard of care.
AB - Radical pelvic irradiation has constituted the definitive therapy for patients
with large cervical cancers. No substantial improvements have been made in
treatment outcomes. In the past year, however, a series of large, well-conducted
randomized trials has evaluated the role of concurrent chemotherapy with pelvic
irradiation in cervical cancer. These trials include definitive treatment of
patients with stage IB2 to IVA disease and adjuvant treatment after radical
surgery in stage IB2-IIA disease. Five trials have shown a consistent 30% to 50%
reduction in the risk of death from disease when concurrent chemotherapy is used.
Questions still remain as to what constitutes the best chemotherapy dose and
schedule. In all of the positive trials, cisplatin was used, but three also used
5-fluorouracil. The level of survival improvement that occurs when chemotherapy
is added to optimal irradiation and whether patients with stage IIIB and IVA
benefit are also unclear. Improvements in survival rates for patients with solid
tumors occur slowly. Based on the evidence, it is likely that concurrent
chemotherapy with radiation will become the new standard of care for bulky and
advanced cervix cancer.
PMID- 10671659
TI - Adjuvant therapy for high-risk, early stage cervical cancer.
AB - The identification of various pathologic risk factors after primary surgical
management of early stage cervical cancer portends a higher rate of relapse and
decreased survival. Historical attempts to improve outcome focused mainly on the
use of adjuvant pelvic radiation, with limited success overall. Analysis of
patterns of failure after radical hysterectomy led to better stratification of
patients into risk groups and incorporated testing of systemic agents in those
considered at high risk of distant failure. Two recently reported randomized,
clinical trials have greatly advanced our understanding of the role of
postoperative therapy in cervix cancer. In patients with positive nodes, the use
of combined adjuvant chemotherapy and radiation significantly improves relapse
free survival and overall survival, compared with radiation alone. For node
negative patients with other primary tumor risk features, pelvic radiation
significantly improves relapse-free survival, compared with no further therapy.
An observed improvement in survival for irradiated patients awaits statistical
confirmation after maturation of the data. Further improvements in adjuvant
therapy for high risk, early stage cervical cancer will come from enhanced
definition of prognostic variables, better patient selection, and refinements in
both local and systemic therapies.
PMID- 10671660
TI - Integrating radiation therapy in the curative management of ovarian cancer:
current issues and future directions.
AB - Although important advances in surgery, chemotherapy (CT), and radiation therapy
(RT) have been made, overall survival for patients with ovarian cancer (OC) has
not changed significantly. Despite its long history in the treatment of OC and
its proven curative role in patients with microscopic or minimal residual
disease, the proper role of RT in the management of OC is not clearly
established. Although the use of primary adjuvant RT (whole abdominal
irradiation) has declined in the last 15 years, there has been a resurgence of
interest in RT as part of a combined modality approach and as salvage therapy for
patients with small-volume persistent disease after primary cytoreductive surgery
and platinum-based CT. This article reviews the evidence supporting the use of RT
alone or combined with chemotherapy as primary adjuvant therapy or in the salvage
setting. Current issues in the radiotherapeutic management are discussed along
with ideas for future clinical research directions.
PMID- 10671661
TI - Differential effects of retinoids on nitric oxide production by promonocytic U937
cells and ZR-75-1 human breast cancer cells.
AB - We demonstrated the presence of inducible and endothelial nitric oxide synthases
in histiocytic lymphoma U937 cells by staining with anti-iNOS and anti-eNOS
antibodies. We also investigated the effects of retinol and retinoic acid on
nitric oxide production by both U937 cells and ZR-75-1 human breast cancer cells.
U937 cells which had been treated with either retinol or retinoic acid (10-10-10
6 M) exhibited no significant difference in nitric oxide secretion into
conditioned medium. Conversely, for ZR-75-1 cells, both retinol and retinoic acid
(10-10-10-6 M) caused a significant (p<0.001) increase in the amount of nitrite
secreted. Our results indicate that retinoid induced growth inhibition of breast
cancer cells is associated with an increase in NO production, however, an
increase in NO synthesis does not mediate retinoid induced differentiation of
U937 cells.
PMID- 10671662
TI - A novel monoclonal antibody, H9, directed against the core protein of MUC1 mucin.
AB - MUC1 mucin is a target protein for many monoclonal antibodies. Human MUC1
detected by a murine anti-KL-6 monoclonal antibody that recognizes a sialylated
carbohydrate chain has been designated KL-6/MUC1. Given the heterogeneous
antigenicity of KL-6/MUC1, we established a new murine monoclonal antibody, H9,
that reacts with epitope DTRP (Asp-Thr-Arg-Pro) peptides within the
immunodominant region of the tandem repeat of MUC1 mucin. The reactivity of the
H9 antibody differs from that of other previously reported antibodies that
recognize the tandem repeat region of MUC1. Immunohistochemical experiments
indicate that the reactivity of the H9 antibody is similar to that of other
antibodies directed against MUC1 core proteins. A new cancer-associated protein
detected by a sandwich assay using the H9 antibody as a catcher and the KL-6
antibody as a tracer is designated HK9. Serum HK9 levels showed a high expression
level in lung cancer: 51% (19/37 cases) for adenocarcinoma, 39% (11/28 cases) for
squamous cell carcinoma, and 67% (10/15 cases) for small cell carcinoma. The HK9
expression in lung cancer increased with cancer progression. These findings
suggest monoclonal antibody H9 to be a novel antibody that reacts with an epitope
within the tandem repeat region of MUC1, and that the cancer-associated antigen
HK9 may have useful tumor-associated properties.
PMID- 10671663
TI - pS2 expression as a possible diagnostic marker of colorectal carcinoma in
ulcerative colitis.
AB - This study was performed to evaluate the significance of pS2 and MUC1 expressions
in ulcerative colitis (UC)-associated colorectal neoplasias. Tissues were
collected from 6 patients with UC-associated colorectal neoplasias treated
surgically. Specimens were 13 adenocarcinomas, 40 dysplasias (20 high-grade
dysplasias, 20 low-grade dysplasias), and 60 normal mucosae. Tissues were also
collected from patients without UC treated surgically or endoscopically. pS2,
p53, and MUC1 expressions were examined immunohistochemically and compared. The K
ras codon 12 mutation was investigated by single-strand conformation polymorphism
analysis. In patients with UC, the incidence of pS2 expression was significantly
higher (p<0.01) in adenocarcinomas than it was in dysplasias, and no pS2
expression was seen in normal mucosae. p53 overexpression was detected in 50%
(10/20) even in low-grade dysplasias. MUC1 expression was seen only in invasive
carcinomas, but it was seen in 100% of cases (3/3). K-ras gene mutations were
detected in 2 (20%) of 10 carcinomas. In low and high-grade dysplasias, the
incidences of pS2 expression were significantly (p<0.01) lower than the
incidences of p53 overexpression, however, in UC-associated carcinomas there was
no significant difference; pS2 expression and p53 overexpression were detected in
13 of 13 (100%) cases and in 12 of 13 (92%) cases, respectively. These results
suggest that p53 overexpression may be a diagnostic marker of neoplasia, and that
pS2 expression may be a diagnostic marker of colorectal carcinoma in case of UC.
PMID- 10671664
TI - A favorable impact of preoperative FPLC chemotherapy on patients with gastric
cardia cancer.
AB - The aim of this study is to evaluate the effects of preoperative chemotherapy
with fluorouracili polyphase liposome composita pro orale (FPLC) on the tumour
cells and the survival rate of the patients with gastric cardia cancer. Sixty
patients with gastric cardia cancer were randomly divided into two groups. Thirty
patients were treated with FPLC prior to surgical resection, the other 30, as
controls, did not receive the preoperative chemotherapy. Pathological responses
of the tumours to the FPLC chemotherapy were determined by gross and microscopic
assessments of tumour size, tumour emboli, cell degeneration and necrosis.
Expressions of nm23 and CD44 were detected by flow cytometry. All patients were
followed up to 5 years. In the FPLC-treated patients, the tumour size (p<0. 01),
the number of tumour emboli (p=0.04) and the intensity of CD44 expression
(p<0.001), were significantly reduced, while cell degeneration (p<0.001),
necrosis (p<0.01) and the expression of nm23 (p<0.001) were increased, when
compared with those observations seen in the controls. The postoperative 5-year
survival rate was 40% in the FPLC-treated group and 23% in the controls (p=0.17).
Preoperative FPLC chemotherapy might improve the survival rate of patients with
gastric cardia cancer by inhibiting tumour proliferative, invasive and metastatic
activities, and stimulating the patient's immune system.
PMID- 10671665
TI - Is a woman's date of birth related to her risk of developing breast cancer?
AB - Some previous reports have shown seasonality in the date of birth in patients
with breast cancer, others have not. In this study of 1,110 women with unilateral
breast carcinoma significantly more cases had been born in the first than the
second half of the year. This finding could, however, not be linked to the later
development of breast cancer as their case-matched controls showed a similar
trend. These results underline the importance of using relevant control material
in such studies.
PMID- 10671666
TI - A simultaneous monitoring of Lens culinaris agglutinin A-reactive alpha
fetoprotein and des-gamma-carboxy prothrombin as an early diagnosis of
hepatocellular carcinoma in the follow-up of cirrhotic patients.
AB - To elucidate the risk factors for developing hepatocellular carcinoma (HCC)
during the follow-up of patients with liver cirrhosis (LC), outpatients with LC
were examined periodically by means of serum biochemical assessments,
ultrasonography, and computed tomography. Risk factors for HCC were statistically
analyzed. We also examined an efficacy of Lens culinaris agglutinin A-reactive
profiles of alpha-fetoprotein (AFP-L3%) and des-gamma-carboxy prothrombin (DCP)
value using a highly sensitive DCP determination kit (ED036) for the early
recognition of HCC. The AFP-L3% and the ED036 value were retrospectively
determined with stored serum samples. HCC was diagnosed in 21 of the 78 patients
with LC during the follow-up period (mean follow-up period: 42 months). The
estimated cumulative incidence of HCC was 25% with 3 years and 48% with 5 years.
The most significant risk factor for the development of HCC in LC patients was
found to be the mean serum AFP concentration from the year before the HCC
detection (p=0.02). At the time of the recognition of HCC, the positive rates of
the tumor markers were: serum AFP concentration 14%, serum DCP value 5%, AFP-L3%
was 33%, and that of ED036 43%. The positive rate in collaborative use of AFP-L3%
and ED036 was 67%. The simultaneous determination of the AFP-L3% and the ED036
value was shown to be effective for the early detection of HCC.
PMID- 10671667
TI - In vivo chemosensitivity of human malignant cystosarcoma phyllodes xenografts.
AB - Malignant cystosarcoma phyllodes (MCSP) is a rare breast tumor. Chemotherapeutic
regimens for treatment of MCSP have not been established. We previously
established an MCSP xenograft line MC-3-JCK. In this study, we established a new
MCSP xenograft line, MC-10-JCK, by serial transplantation in nude mice. We
studied the chemosensitivity of these two MCSP tumor xenografts to anticancer
drugs in vivo. We also examined the expression of multidrug resistance-related
proteins such as p-glycoprotein (Pgp) and multidrug resistance-associated protein
(MRP) by immunohistochemical analysis. These two xenografts were sensitive to
doxorubicin, vincristine and cyclophosphamide in vivo. Immunohistochemically,
clinical specimens and xenografts were negative for Pgp and MRP expression. These
results are consistent with the chemosensitivity of human MCSP to lipophilic
anticancer compounds.
PMID- 10671668
TI - Induction of p53-dependent apoptosis in vivo by nedaplatin and ionizing
radiation.
AB - p53 protein expression, apoptosis and growth delay induced by nedaplatin, a novel
platinum compound, were investigated in vivo, and compared with those induced by
ionizing radiation. A human ependymoblastoma with wild-type p53 was transplanted
subcutaneously to the thighs of nude mice. The incidences of p53 protein-positive
cells and apoptosis in tumors increased following exposure to ionizing radiation.
In tumors treated with nedaplatin, they also increased, but the incidences of p53
protein-positive cells and apoptosis induced by 32 mg/kg nedaplatin, 1/2 LD50,
were lower than those induced by 1 Gy irradiation. However, growth-delay assay
showed no significant difference between the efficacy of 32 mg/kg nedaplatin and
that of 1 Gy irradiation. These results suggest that the main antineoplastic
activity caused by nedaplatin may be mediated through different mechanisms than
those of the p53-dependent early apoptosis.
PMID- 10671669
TI - Comparison of effects of doxorubicin and radiation on p53-dependent apoptosis in
vivo.
AB - The effects of doxorubicin and radiation on apoptosis, p53 expression, and tumor
growth in human tumor xenografts were investigated. Human ependymoblastoma (NNE),
primitive neuroectodermal tumor (YKP), glioblastoma (KYG) and small cell lung
carcinoma (GLS) that are all transplantable to nude mice were treated with
doxorubicin (8 mg/kg) or radiation (1 Gy). The histological study was performed
by using TUNEL and p53 staining. Cytotoxic effects of doxorubicin and radiation
were compared with no-treatment group by the growth curves and apoptotic index of
tumor to each treatment. In NNE with wild-type p53, doxorubicin induced growth
delay of tumors (tumor volume doubling time; 13.7+/-3.3 days in control group vs
30.4+/-1.5 days in doxorubicin group), but no growth delay of tumors in KYG and
GLS with mutant type p53. While radiation-induced apoptosis appeared most
frequently at 6 h after irradiation, doxorubicin-induced apoptosis had a tendency
to appear later. Furthermore, although the frequency of doxorubicin-induced
apoptosis was lower than that of apoptosis by 1 Gy irradiation, apoptotic cells
appeared for many hours after the treatment. Doxorubicin-induced apoptosis may be
correlated with p53 phenotype because apoptosis was induced only in tumor with
wild-type p53, but it appeared less frequently and later than radiation-induced
apoptosis.
PMID- 10671670
TI - Perioperative quantitative analysis of cytokeratin 20 mRNA in peripheral venous
blood of patients with colorectal adenocarcinoma.
AB - Hematogenous dissemination is a significant short-coming of colorectal carcinoma
treatment. To screen patients with high risk for such blood-borne metastasis, we
previously developed a highly sensitive system for the detection of cytokeratin
20 (CK-20) mRNA in blood. For a more practical application, we improved this
system by making it quantitative and capable of analyzing peripheral venous blood
for the detection of perioperative changes in CK-20 mRNA. CK-20 mRNA was not
always detected in the preoperative blood, even in patients in an advanced stage,
but it was identified without fail in intra- and post-operative blood. In
addition, more copies of CK-20 mRNA were observed in the intra-operative blood
than in pre- and post-operative blood. This study suggests that analysis of
perioperative changes may provide important information for the precise
evaluation of hematogenous dissemination and of the effect of surgical maneuvers
on recurrence.
PMID- 10671671
TI - Expression of estrogen and progesterone receptors in carcinomas of the female
breast in Tanzania.
AB - In Africa breast cancer has been reported to occur frequently in young females
and to show an aggressive histological and clinical picture, suggesting that this
malignancy might have a different biology from this disease in Western females.
To investigate this, the present study assessed by immunohistochemistry the
expression of estrogen receptors (ER) and progesterone receptors (PgR) in 60
fresh frozen breast cancer tissues from indigenous Tanzanian patients. This
prospective study collected tissues from routine patients treated at the
Muhimbili Medical Center, Dar es Salaam, Tanzania. These markers have not been
previously investigated in indigenous sub-Saharan females with breast cancer.
Patients in this study expressed lower frequencies of ER (33%) and PgR (18%) as
compared to literature reports including those about African-Americans.
Expression of these markers, however, correlated with the demographic, clinical
and histological characteristics in a similar way as observed elsewhere. A
compounding effect of younger patients' age, advanced disease or late stage at
hospital presentation and race in this geographical region could be responsible
for the poor expression of hormonal receptors in the majority of patients as
observed in this study. A surprising finding was that the proportion of hormonal
receptor positive tumors increased with disease duration. In view of the low
frequency of expression of hormonal markers, only 26.7% of the patients would be
expected to benefit from hormonal therapy based on their expression of the
hormone receptors. There is great need to undertake an inter-African study that
would evaluate the hormonal status of more African women with breast cancer in
different geographical regions of sub-Saharan Africa and document the true
picture of their hormonal status. The outcome of these results could be important
for treatment strategies for the second most common cancer among African women.
PMID- 10671672
TI - Bcl-2 related proteins are dramatically induced at the early stage of
differentiation in human liver cancer cells by a histone deacetylase inhibitor
projecting an anti-apoptotic role during this period.
AB - Expression of the Bcl-2 family members in a human hepatocellular carcinoma cell
line (HCC-T) after sodium butyrate-treatment was investigated. Sodium butyrate, a
histone deacetylase inhibitor, induced differentiation of the cell line into its
normal counterpart without inducing apoptosis at the concentration of 2 mmol/l.
Since sodium butyrate has effects on both differentiation and apoptosis, we
investigated the expression profile of bcl-2 related genes in HCC-T. The
expression of Bcl-2 and Mcl-1/EAT was up-regulated 4-12 h after the treatment
while Bcl-XL was up-regulated 2-3 days after the stimulation. On the other hand,
the expression levels of Bax protein remained unchanged during differentiation.
The HCC-T cells entered a cell cycle arrest at G1 and showed neither cellular
fragmentation nor apoptosis during this period, which was concomitantly
associated with up-regulated expression of a cell cycle regulator, p21WAF-1.
These results demonstrate that induction of anti-apoptotic bcl-2 related proteins
at an early stage of differentiation is important for the maintenance of HCC-T
cell differentiation by antagonizing pro-apoptotic molecules such as Bax.
PMID- 10671673
TI - Experimental study of the effects on apoptosis of docetaxel alone and in
combination with irradiation.
AB - The effects of docetaxel alone and in combination with irradiation were
experimentally investigated in terms of induction of apoptosis. A human
ependymoblastoma was transplanted into nude mice, and they were intravenously
injected with docetaxel, followed or preceded by irradiation with a single dose
of 2 Gy. Apoptosis was less common in the docetaxel-alone group than in the
irradiation-alone group. When administration of docetaxel was followed by
irradiation, apoptosis was equal to or less common than in the irradiation-alone
group. Apoptosis was most common in the irradiation-followed-by-docetaxel group.
The incidence of mitosis was lower in the irradiation-alone group and the
irradiation-followed-by-docetaxel group than in the docetaxel-alone group and the
docetaxel-followed-by-irradiation group. The combined effect of irradiation and
docetaxel appears to be useful in inducing apoptosis, but the sequence of
irradiation and docetaxel is important.
PMID- 10671674
TI - Immunohistochemical study on primary and recurrent tumors in patients with local
recurrence in the conserved breast.
AB - One hundred and seventy patients received breast-conserving therapy in the Second
Department of Surgery, Gunma University School of Medicine. Six (3.5%) out of the
170 patients showed breast recurrence. We investigated the breast recurrent cases
clinicopathologically. The age at the initial operation ranged from 38 to 78
(mean 57) years. One patient was clinical stage I and the others were clinical
stage II. Surgical margin at the initial operation was negative in two patients
and positive in four. Histological type was invasive ductal cancer in all cases.
Three patients had lymph node involvement. The interval from the initial
operation to breast recurrence ranged from 19 to 68 months. Five cases were
nodular type and one was diffuse type of breast recurrence. Histological type of
breast recurrence was the same as the initial one. We performed salvage surgery
for all breast recurrent patients, mastectomy for four patients and local
resection for two. One patient who showed diffuse type of recurrence could not be
controlled with any surgical treatment, and later died of breast cancer. We
investigated the expression of estrogen receptor, progesterone receptor, pS2, c
erbB-2 and p53 on both initial and recurrent specimens of the six patients. The
expression of each protein on the recurrent specimens was the same as the initial
one. We conclude that breast recurrence after breast-conserving therapy has its
origin in the residue of cancer cells at the initial operation, even if surgical
margins are histopathologically negative.
PMID- 10671675
TI - DNA double-strand break rejoining in human follicular lymphoma and glioblastoma
tumor cells.
AB - Follicle center cell lymphoma is among the most radioresponsive of human cancers.
To assess whether this radioresponsiveness might be a result of a compromised
ability of the tumor cells to accomplish the biologically-effective repair of DNA
double-strand breaks (DSBs), we have measured i) the extent of the mechanical
rejoining of radiation-induced DSBs in biopsy-derived follicle center cell
lymphoma cells and ii) the fidelity with which nuclear protein extracts from
these cells rejoin restriction enzyme-induced DSBs. Cell suspensions derived from
two lymphoma biopsies, designated FCL1 and FCL2, as well as two established human
glioblastoma cell lines, M059J and M059K, were exposed to 30 Gy of gamma-rays and
evaluated for their ability to rejoin DSBs using a Southern transfer-pulsed-field
gel electrophoresis assay. The fidelity of rejoining of restriction enzyme
induced DSBs was assessed using a cell-free plasmid reactivation assay. Both
lymphoma suspensions rejoined DSBs relatively slowly and exhibited a similar
phenotype to the known DSB-rejoining deficient M059J line. The level of DSB mis
rejoining in the cell-free plasmid reactivation assay was also similar in M059J
and FCL2 cells and was considerably ( approximately 6-fold) higher than in M059K
cells. Because of insufficient numbers of cells, we were unable to perform this
assay with the FCL1 lymphoma. These limited data suggest that follicle center
cell lymphoma cells may be intrinsically deficient in performing the biologically
effective rejoining of DSBs. Such a deficiency might contribute to the
radioresponsiveness of this disease and may be exploitable in the development of
improved treatment strategies, such as radioimmunotherapy.
PMID- 10671676
TI - Dose-intensive weekly alternating chemotherapy for patients with small cell lung
cancer: randomized trial, can it improve survival of patients with good
prognostic factors?
AB - We conducted a randomized trial of dose-intensive weekly alternating chemotherapy
(CAV/PE-W) and standard alternating chemotherapy (CAV/PE) in small cell lung
cancer (SCLC) patients with good prognostic factors. A total of 76 patients with
SCLC was randomized. The CAV/PE-W consisted of 4 alternating cycles of
cyclophosphamide: 500 mg/m2, doxorubicin: 30 mg/m2, and vincristine: 1 mg/m2 (day
1) and cisplatin: 50 mg/m2 (day 8) and etoposide: 75 mg/m2 (days 8 and 9). The
CAV/PE consisted of 2 alternating cycles of cyclophosphamide: 800 mg/m2,
doxorubicin: 50 mg/m2, and vincristine: 1.4 mg/m2 (day 1), cisplatin: 100 mg/m2
(day 22) and etoposide: 100 mg/m2 (days 22, 23 and 24). Eligibility criteria were
no prior therapy, no active concomitant malignancy, ECOG PS of 0 or 1, age < or
=75, adequate hematologic functions and no brain metastasis. The complete
response (CR) rate for CAV/PE-W (14/38, 36.8%) was significantly higher than that
for CAV/PE (6/38, 15.8%, chi2; p=0. 032). However, the response rate in patients
on CAV/PE-W (36/38, 94. 7%) was not significantly higher than the rate for CAV/PE
(31/38, 81. 6%, chi2; p=0.076). Progression-free survival for patients on CAV/PE
W was significantly longer than that of patients on CAV/PE (41.4 weeks vs. 21.3
weeks, log-rank; p=0.0007, generalized Wilcoxon; p=0.0034) as was overall median
survival (67.0 weeks vs. 51.2 weeks, log-rank; p=0.028). Actual dose-intensity of
CAV/PE-W was 1.74 times that of CAV/PE. Hematological toxicities were equally
frequent and G-CSF contributes to treatment efficacy by allowing administration
of dose-intensive chemotherapy. The CAV/PE-W achieved a higher CR rate and longer
survival, than the CAV/PE.
PMID- 10671677
TI - Retrospective study of the prognostic factors of remission induction for single
agent chemotherapy with cisplatin in advanced epithelial ovarian cancer.
AB - A retrospective study to explore the prognostic factor was conducted in 39
patients with advanced epithelial ovarian cancer, FIGO stage III-IV, who
underwent single-agent adjuvant chemotherapy with cisplatin following primary
debulking surgery. The survival rate following the adjuvant chemotherapy was
50.9% after 3 years and 44. 7% after 5 years, with a median survival time of 40.4
months. The actual dose intensity of the cisplatin ranged from 14.38 to 46.30
mg/m2/week, and the total dose/m2 was 143.79 to 645.83 mg/m2. Under these
therapeutic conditions, the actual dose intensity was found to correlate with
survival time (p<0.05), but there was no correlation between the total dose/m2
and survival time.
PMID- 10671678
TI - Genomic DNA analyses of spontaneous hepatocellular carcinomas in LEC rat liver
using a new technique.
AB - An inbred rat strain, LEC (long evans cinnamon) has been used as a model of human
Wilson's disease. This animal suffers from a severe type of hepatitis, the
clinical manifestations of which are similar to human fulminant hepatitis for 4-5
months which is caused by accumulation of copper in the liver. The surviving rats
develop chronic hepatitis, followed by the development of spontaneous hepatoma.
In contrast to studies with hepatocellular carcinomas (HCCs), the studies have
great advantages in that the animals have identical genetic background, can be
raised under a fixed condition, and the development of HCC is reproducible. We
took two HCC samples and analysed their genomic DNA using RLGS (restriction
landmark genomic scanning), which involves two-dimensional electrophoresis of
genomic DNA allowing the survey of some 1,000 NotI sites throughout the genome.
Using this technique, we discovered landmark spots that were either decreased or
increased in intensity in HCC and compared them with the RLGS profile obtained
from the DNA of control normal LEC rat liver. Approximately 1,300 spots were
compared, and the intensity of two spots was found to be decreased about half and
one was increased 1.3-1.7 folds. Although the mechanism of these changes and the
properties of the changed DNA are yet to be studied, recurrent genomic changes in
the LEC rat HCC could prove to be a good model system for elucidating the
essential genetic events in association with hepatocarcinogenesis.
PMID- 10671679
TI - Prognostic comparison between peripheral and central types of squamous cell
carcinoma of the lung in patients undergoing surgical resection.
AB - In order to define whether the location of the tumor [peripheral (P) or central
(C)] may have some influence on the prognosis for patients with squamous cell
carcinoma of the lung, we analyzed 235 patients under 80 years of age (P-group =
129, C-group = 106) who had undergone surgical resection between January 1985 and
December 1997. There was no significant difference in the prognosis between the
two groups with stages I(0)-IIIB of the disease. We concluded that as a whole the
location of the tumor may not have significant influence on the prognosis in
patients with squamous cell carcinoma of the lung undergoing surgical resection.
PMID- 10671680
TI - Mutational analysis of the CTNNB1 (beta-catenin) gene in human endometrial
cancer: frequent mutations at codon 34 that cause nuclear accumulation.
AB - Recently, CTNNB1 (beta-catenin) has been found to function as an oncoprotein that
works in the Wnt signaling pathway, and mutation of this gene has been reported
in various human cancers. In this study, we analyzed 44 endometrial cancers and
found somatic missense mutations in five (11%) tumors. Interestingly, four (80%)
of the five tumors with mutations would cause amino acid alterations at residues
next to Ser 33, one of the targets for phosphorylation of glycogen synthase
kinase (GSK)-3beta. The tumors with mutations showed accumulation of the CTNNB1
protein in cytoplasm and nucleus. This is the first report of frequent somatic
mutation of the CTNNB1 gene at codons adjacent to those encoding to Ser/Thr
residues in endometrial cancer.
PMID- 10671681
TI - Exploratory study of effective chemotherapy to clear cell carcinoma of the ovary.
AB - Although clear cell carcinoma of the ovary is considered to be a tumor with poor
prognosis, the clinical characteristics has not been defined. The aim of this
study was to evaluate the response of clear cell carcinoma of the ovary to first
and second-line chemotherapy and explore effective chemotherapy. Fifty-three
patients with clear cell carcinoma of the ovary were enrolled between 1988 and
1997 at our department. Since taxol was not available in Japan at that time,
cisplatin-based combination chemotherapy has been exclusively used as a standard
first-line chemotherapy. Retrospective analyses of clinical characteristics and
the response to first or second-line chemotherapy were performed. Median age was
52 years (range 27-71 years). Tumors were 34% (18/53) stage I, 19% (5/53) stage
II, 38% (20/53) stage III, and 9% (5/53) stage IV. All patients with I or II
stage disease had optimal cytoreduction. Out of 25 patients with III or IV stage
disease 20% (5/25) had negative residual tumor, 36% (9/25) had <2 cm residual
tumor, and 44% (11/25) had >/=2 cm residual tumor. All patients received
postoperative platinum-based chemotherapy. Of 23 patients with measurable
residual tumor 8.7% (2/23) completely and 13% (3/23) partially responded to first
line chemotherapy consisting of cisplatin, adriamycin and cyclophosphamide (CAP)
or cisplatin and cyclophosphamide (CP) by CT scan or second look laparotomy.
Presence of endometriosis was 55% (29/53) but was not a prognostic factor.
Although overall response rate of ovarian clear cell carcinoma to first-line
chemotherapy by CAP or CP was about 22%, EP or EJ consisting of etoposide and
cisplatin or carboplatin used as a second-line chemotherapy showed 29% response
rate, while CPT-P consisting of CPT-11 and cisplatin showed 40% response rate.
Clear cell carcinomas were frequently present at early stage, with association of
endometriosis and with poor overall prognosis. Although patients with advanced
ovarian clear cell carcinoma seemed to have better response to CPT-P than
conventional platinum-based chemotherapy, further studies are required with
larger number of patients to draw firm conclusions.
PMID- 10671682
TI - Clinical significance of serum vascular endothelial growth factor in colorectal
cancer patients: correlation with clinicopathological factors and tumor markers.
AB - Vascular endothelial growth factor (VEGF) is known as a potent inducer of
angiogenesis in various human cancers. Serum VEGF concentrations of colorectal
cancer patients was assessed for their clinical significance as a tumor marker.
Serum samples were obtained at admission from 24 healthy volunteers and 111
patients with colorectal cancer. Preoperative serum VEGF concentrations, which
are significantly higher than those of healthy controls, reflect clinical stage
progression, depth of invasion, liver metastasis, lymph node metastasis and
lymphatic invasion. Consequently, detection of VEGF could serve as a clinically
useful marker for colorectal cancer progression and metastasis independent of
other markers.
PMID- 10671683
TI - Neoadjuvant chemotherapy for osteosarcoma of the extremities with synchronous
lung metastases: treatment with cisplatin, adriamycin and high dose of
methotrexate and ifosfamide.
AB - We report on the clinical course and outcome of 28 patients, treated at The
Istituti Ortopedici Rizzoli between 1995 and 1997 for osteosarcoma of the
extremities metastatic to the lung at presentation. The treatment for these
patients was the following: primary chemotherapy with cisplatin, adriamycin and
high dose of methotrexate and ifosfamide followed by simultaneous resection of
primary and metastatic lesions (when feasible), and further chemotherapy. After
primary chemotherapy, lung metastases disappeared in 6 patients, whereas
metastases in 3 remained surgically unresectable. These 9 patients received
surgical treatment of the primary tumor only. In the remaining 19 patients, after
chemotherapy, a simultaneous resection of the primary and metastatic tumor was
performed. The resection of metastatic lesions was complete in 18 cases and
incomplete in one. Three of the 4 patients who did not achieve a tumor-free
status died in a few months and one is still alive with uncontrolled disease.
With a median follow-up of 32 months (19-43) of the 24 patients who achieved
remission, 12 (55%) remained continuously free of disease, 11 relapsed with new
metastases and 1 died of chemotherapy-related toxicity. The 2-year DFS and OS
were 36% and 53% respectively. These results are much worse than those achieved
in 114 contemporary patients with localised disease (2-year DFS: 81%) treated in
the same period and they are superimposible to the results achieved in 23
patients previously treated with the same protocol, but with standard dose of
ifosfamide (2-year DFS: 32%). However, it must be underlined that, as regards
prognosis, patients with metastatic disease at presentation are a hetero-geneous
group. The DFS was significantly higher for patients with only one or two
metastatic lesions than for patients with 3 or more lesions (2 year DFS: 78% vs.
28%). In 12 of the 19 patients who had a complete simultaneous resection of the
primary and metastatic tumor, a strong correlation between the degree of necrosis
of the primary and metastatic lesions was found. We conclude that in patients
with osteosarcoma of the extremity with lung metastases at presentation: a) the
combination of aggressive chemotherapy with simultaneous resection of primary and
metastatic tumors works very well only for those patients who present with one or
two metastatic nodules whereas for patients with 3 or more pulmonary metastases
the prognosis is very poor; b) within the 4-drug regimen used in this study, the
increment of ifosfamide dose from 10 g/m2 to 15 g/m2 for cycle does not improve
prognosis; c) the strong correlation found between the histologic response of the
primary tumor and metastases supports the strategy, largely used nowadays in the
neoadjuvant treatment of osteosarcoma, of tailoring postoperative chemo-therapy
on the basis of the primary tumor histologic response to preoperative
chemotherapy.
PMID- 10671684
TI - Antiproliferative action of melatonin on human prostate cancer LNCaP cells.
AB - Recent experimental evidence suggests that melatonin, the major pineal hormone,
might possess oncostatic properties. The present experiments were performed to
verify whether melatonin might modulate the growth of androgen-dependent prostate
cancer cells (LNCaP) and to obtain information on its possible mechanism of
action. We have shown that melatonin, when given in the nanomolar range,
significantly inhibits the proliferation of LNCaP cells; moreover, the pineal
gland hormone affects cell cycle distribution by inducing an accumulation of the
cells in G0/G1 and a decrease in S phase. To investigate the mechanism of action
of melatonin, by RT-PCR analysis we were able to demonstrate the expression, in
prostate cancer cells, of a mRNA coding for the membrane Mel1a melatonin
receptor. However, by radioreceptor assay, no detectable binding of 2
[125I]iodomelatonin could be observed in membrane preparations from these cells,
suggesting that the levels of translation of the mRNA for Mel1a are possibly too
low to mediate the antiproliferative action of the hormone. This hypothesis is
further supported by the following observations: i) melatonin analogs,
specifically acting through membrane receptors (i.e., 2-bromomelatonin), were
completely ineffective in modulating prostate cancer cell proliferation; ii)
melatonin failed to prevent forskolin-induced cAMP accumulation. These results
indicate that melatonin, at nanomolar concentrations, exerts a direct
antiproliferative action on androgen-dependent prostate cancer cells,
significantly affecting their distribution throughout the cell cycle. Membrane
receptors do not seem to be involved in the oncostatic action of the pineal gland
hormone.
PMID- 10671685
TI - Correlation of immunohistochemical staining and mutations of p53 in human
hepatocellular carcinoma.
AB - Mutations of the p53 tumor suppressor gene are common in hepatocellular
carcinomas (HCCs). Detection of mutations by sequencing provides more information
than immunohistochemical staining, but the equipment needed and the time required
make it less practical for use in large-scale studies or in studies in developing
countries. The degree of correlation between results obtained with these two
methods has been studied in various tumors but has not been well-established in
human HCCs. Paraffin sections of HCCs of 28 patients from Qidong, China were
immunohistochemically stained using monoclonal antibody to p53. In addition,
exons 5-8 of the p53 gene were sequenced in these HCCs. Of the 28 HCCs, nine had
0-9% of nuclei stained for p53, and 19 had 50-95% stained. Mutations in p53 exons
5-8 were found in 17/28 (61%) HCCs, including 15 at codon 249 (exon 7), one at
codon 198 (exon 6), and one at codon 175 (exon 5). Among these 17 cases with p53
mutations, 16 cases (94%) had 50-95% of nuclei stained. Among 11 HCCs with no
mutations by sequencing, 8 were also negative by immunohistochemistry (0-9% of
nuclei stained) (73%) (the five HCCs with no staining whatsoever all had wild
type p53). Immunohistochemical staining to detect p53 mutations in human HCCs
detected most mutations that were detected by sequencing (94% sensitivity, 73%
specificity), and this method is therefore suitable when sequencing cannot be
performed.
PMID- 10671686
TI - Serum interleukin-10 is an independent prognostic factor in advanced solid
tumors.
AB - Interleukin (IL)-10 is a Th2 type pleiotropic cytokine that has been found to be
produced at the tumor site and to be increased in sera of patients suffering from
different types of cancer. IL-10 has been shown to hinder a number of immune
functions, i.e., T lymphocyte proliferation, Th1 type cytokine production,
antigen presentation, and lymphokine-activated killer cell cytotoxicity. To
assess its prognostic value, we measured serum levels of IL-10 in 118 patients
with advanced solid tumors before treatment, after completion of therapy, and
during follow-up. Other prognostic variables, to which IL-10 results were
compared, were analyzed as well. IL-10 serum levels were found significantly
elevated in cancer patients with respect to healthy controls. Of interest, a
significant decrease in IL-10 serum levels was observed in the responder group,
whereas a significant increase was recorded in the non-responder group. Using
univariate and multivariate analyses, a significant relationship was shown
between IL-10 serum levels and both overall survival (OS) and time to treatment
failure (TTF). Stepwise regression analysis selected IL-10 serum level,
performance status (PS), and stage as the best association of variables with
significant impact on OS and TTF. In conclusion, this study shows that IL-10 has
an independent prognostic significance in patients with advanced solid tumors and
may be useful for monitoring disease progression.
PMID- 10671687
TI - Bovine seminal ribonuclease inhibits in vivo growth of human neuroblastoma cells.
AB - Bovine seminal ribonuclease (BS-RNase) is a homologue of RNase A with specific
antitumor activities. It is selectively toxic for neuroblastoma (NB) cells in
vitro with no significant effects on the viability of normal human cells. We
evaluated the antitumoral effects of BS-RNase on human NB xenografts from UKF-NB
3 cells in athymic (nude) mice. The efficacy of direct intraneoplastic,
subcutaneous and systemic delivery of BS-RNase was explored. Systemic
administration of BS-RNase (12.5 mg/kg/day intraperitoneally, for 20 days in the
course of four weeks) suppressed tumor growth but was not able to induce any
cures. Subcutaneous injections (12.5 mg/kg/day for 20 days in the course of four
weeks) and intratumoral BS-RNase treatment using the same schedule resulted in
complete tumor regression. During 30 days following cessation of treatment no
tumor regrowth was observed and animals were free of tumors. Toxic effects of BS
RNase (e.g., on bone marrow and inner organs) were not apparent. This data
indicates that BS-RNase fulfills important criteria for a candidate antitumor
agent specific for NB.
PMID- 10671688
TI - Frequent genotype changes at -308 of the human tumor necrosis factor-alpha
promoter region in human uterine endometrial cancer.
AB - This study was designed to test the hypothesis that genotypic changes of tumor
necrosis factor alpha (TNF-alpha) promoter region are associated with endometrial
cancer. TNF-alpha gene encodes a cytokine involved in angiogenesis and
oncogenesis of several cancers. Some uncommon alleles are reported to be
associated with increased production of TNF-alpha and the onset of various
cancers. Studies of such alleles are lacking in endometrial cancer. In this
study, we examined the genetic changes at the polymorphic 3 loci of TNF-alpha
promoter regions (-238, -308 and 488) in 41 Japanese patients with uterine
endometrial carcinomas (UEC). Nine of 41 UEC samples (22%) had genotype changes
from GA to A at -308 promoter region of the TNF-alpha gene. There were no
genotype changes at -238 and 488 regions of TNF-alpha in UEC samples. The results
of our study demonstrate for the first time that genotype changes from GA to A in
UEC patients. We conclude that the genotype changes at -308 promoter region of
TNF-alpha may play an essential role in the malignant transformation of
endometrial cells.
PMID- 10671689
TI - The effect of external beam irradiation after endoscopic palliation of esophageal
carcinoma.
AB - The aim of this study was to verify the value of additional external beam
irradiation (EBR) after endoscopic palliation, regarding quality of life and
survival rate. From January 1988 to December 1995, 99 patients with esophageal
carcinoma (squamous cell carcinoma 61; adenocarcinoma 38) were reviewed, there
were 84 males (mean age: 67 years) and 16 females (mean age: 65 years). Seventeen
patients were in stage IIb, 45 stage III and 37 patients in stage IV. HDR
brachyradiotherapy (mean: 14.7 Gy) was carried out in all patients. Additional
EBR (mean: 47.8 Gy) after endoluminal palliation was done in 51 cases. At 6
months follow-up swallowing of a semi-solid diet at least was possible in all
patients and dysphagia was found with significant difference in favour to EBR
only in stage IV (p=0.011). The Karnovsky performance status showed a difference
in favour of EBR for stage III and IV (p=0.040 and p=0. 049, respectively). The
median overall survival for EBR compared to no EBR was 10 and 7 months, with a 12
months survival rate of 60% and 16% (p=0.0012). However, considering different
stages and EBR versus no EBR a significant difference in survival could only be
found for stage IIb (p=0.031), a trend in favour of EBR could be found for stage
III (p=0.0985) and stage IV (p=0.0543). Tumor regrowth 6-12 months after
treatment occurred in 31 cases and was successfully treated with Nd-YAG laser in
25 and stenting in 6 cases. Postirradiation fibrotic stenosis occurred in 12
cases. Improved survival rates after additional EBR can only be expected in stage
IIb. However, in case of advanced esophageal carcinoma and fair performance
status, EBR after endoluminal palliation help to maintain quality of life.
PMID- 10671690
TI - p53 inactivating mutations in chinese breast carcinomas.
AB - While previous reports on breast cancers indicate that Caucasian women have a low
frequency of p53 mutations, higher frequencies of mutations are reported in some
Japanese populations. There are few reports regarding p53 mutations in Chinese
breast carcinomas. Using a previously established sensitive p53 yeast functional
assay, we screened 23 Chinese breast carcinomas for mutations. The p53 was
mutated in 5/23 (21.7%) specimens. Two of these mutations were detected in exon 5
and one was detected in each of exons 6, 7 and 8. All of these mutations have
previously been shown to be mutated in Caucasian and Japanese breast cancers, but
two have not previously been observed in Chinese breast cancers and one has also
not been observed in Japanese.
PMID- 10671692
TI - High fat diet elevates the activity of inducible nitric oxide synthase and 1,2
dimethylhydrazine-induced aberrant crypt foci in colon of rats.
AB - Rats were examined for the effect of dietary level of fat (beef tallow or
safflower oil) on colonic activity of inducible nitric oxide synthase (iNOS)
which has been suggested to be associated with colon carcinogenesis. In
experiment 1, feeding high fat diets (20%) for 3 weeks caused higher activity of
the iNOS compared to feeding low fat diets (5%). In experiment 2, rats were fed
20% or 5% beef tallow diet for 11 or 32 days, and given an injection of a
carcinogen, 1,2-dimethylhydrazine on day 4. The activity of colonic iNOS and the
development of colonic aberrant crypt foci were enhanced by high fat diet.
PMID- 10671691
TI - Susceptibility to the induction of glutathione S-transferase positive hepatic
foci in offspring rats after gamma-ray exposure during gestation.
AB - Glutathion S-transferase positive (GST-P+) hepatic foci development was used as a
means of determining whether the offspring of gestating maternal rats, which were
subjected to genetically-damaging levels of gamma-ray radiation, were more
susceptible to the development of cancer after treatment with diethylnitrosamine
(DEN), a known carcinogen. A single dose of 10, 30, 60, and 90 rads involving
whole body exposure to gamma-rays was given to pregnant rats at day 14, and
during postnatal week 4. DEN was intraperitoneally injected to their offspring
twice in one week. Thirteen weeks after birth, the rats were sacrificed.
Irradiation of maternal rats with 30 rad gamma-rays before mating significantly
increased both the incidence and the size of GST-P+ foci in the livers of both
male and female pups, when combined with DEN treatment, whereas other dose levels
had no such effect. Using a rat-liver model, the results of this study indicate
that a low dose of radiation during the embryonic stage increases the
susceptibility to carcinogens. In addition, under certain circumstances low doses
of radiation, an externally applied cancer-inducing stimulus, may increase the
likelihood of cancer, whereas higher doses may not.
PMID- 10671693
TI - Efficacy and safety profile of amifostine in the preoperative combined therapy of
esophageal cancer patients.
AB - The aim of this study was to assess the protective effect and the safety profile
of amifostine in 16 esophageal cancer patients undergoing neoadjuvant chemo
radiation therapy (group A) compared to 21 matched patients (group B), treated
with the same schedule without receiving amifostine, and considered as controls.
Haematological and extra-haematological toxicity were evaluated according to WHO
criteria and considered as result of amifostine activity. The bone marrow
toxicity was globally lower in group A than in group B. We recorded 4 cases of
mucosities in group B compared to 1 case in group A. amifostine-related side
effects were few (2 cases of hypotension and 1 of vomiting), mild, and well
controlled. In conclusion, amifostine seems to be effective and safe when used as
protective agent also in esophageal cancer.
PMID- 10671694
TI - Cytogenetic and molecular abnormalities in astrocytic gliomas (Review).
AB - In recent years, there have been great advances in our understanding of the
genetic events and the molecular biology of human brain gliomas. Cytogenetic
information has suggested that a pattern of non-random abnormalities involving
numerical deviations such as the gain, partial deletion, or total loss of
chromosomes as well as translocations and structural rearrangements of certain
chromosome lesions are characteristic features for some tumors. In addition, the
somatic activation of cellular oncogenes and inactivation of tumor suppressor
genes represent important genetic alterations leading to progressive disorder of
normal cellular growth control mechanisms. This review describes the abnormal
chromosomal and molecular abnormalities that occur during formation of brain
tumors of astrocytic origin, particularly fibrillary astrocytic neoplasms. The
most frequent genetic alterations include inactivation of the p53, p16, Rb and
PTEN genes, and overexpression of the CDK4, EGFR and VEGF genes. Other less well
defined abnormalities include aberrations in chromosomes 1, 9, 10, 11, 19 and 22.
PMID- 10671695
TI - Giant cell tumor of tendon sheath, tenosynovial giant cell tumor, and pigmented
villonodular synovitis: defining the presentation, surgical therapy and
recurrence.
AB - Giant cell tumor of the tendon sheath (GCTTS), tenosynovial giant cell tumor
(TGCT), and pigmented villo-nodular synovitis (PVNS) are the common names for a
group of rare proliferative disorders that involve synovial joints and tendon
sheaths. Considerable confusion exists about the surgical treatment and diagnosis
of these disorders. This review evaluates the presentation, surgical therapy and
recurrence of these three proliferative disorders. We retrospectively reviewed
the clinical data from all cases of GCTTS, TGCT, and PVNS from 1985 to 1997. A
total of 35 patients were identified: GCTTS (n=8), TGCT (n=1), and PVNS (n=26),
there were 18 men and 17 women. The median age was 48 years (range 6-84 years).
The most common site of involvement was the knee (15), followed by wrist (7),
elbow (4), and hip (4). Seven patients had extra-articular involvement, and 19
were found incidentally at operations for other reasons. Among the 4 patients who
developed recurrent disease, 2 had extra-articular disease at the time of their
original diagnosis. None died, and none required major amputation. One patient
was treated with adjuvant radiotherapy following resection of a recurrence. It is
important to distinguish between focal and diffuse forms of synovial involvement.
If focal, simple surgical excision is appropriate. If diffuse, complete
synovectomy is indicated for disease confined to the joint, and resection of all
gross disease is indicated for extra-articular disease. Radical resection with
negative margins is not necessary in most instances. In rare aggressive cases,
local recurrence may necessitate more extensive resection and radiation therapy.
PMID- 10671696
TI - Alterations in the retinoblastoma pathway of cell cycle control in parathyroid
tumors.
AB - Mutations in proto-oncogenes and tumor suppressor genes have been associated with
tumor development and/or progression in many neoplasms. It has been reported that
parathyroid tumors have deletions affecting the retinoblastoma gene (RB), and
overexpression of cyclin D1 (Cyc D1). The aim of the present study was to
evaluate the alterations in the components of the pRB pathway in parathyroid
adenomas and parathyroid aggressive tumors, including patterns of expression of
pRB, Cyc D1, and p16/INK4A. Paired normal and tumor DNA from 6 parathyroid
adenomas and 5 aggressive tumors were analyzed for loss of heterozygosity (LOH)
at the RB locus. The expression of pRB, Cyc D1 and p16 was studied in 4 adenomas
and 5 aggressive tumors. RB LOH was found in 1 of 6 adenomas, and in 1 of 2
informative aggressive tumors. Immunohistochemical analysis revealed undetectable
pRB in 4 of 5 aggressive tumors and presence of pRB in all adenomas. Conversely,
Cyc D1 expression was found in 3 of 4 aggressive tumors, but was undetectable in
the adenomas. Expression of p16 was identified only in one aggressive tumor.
Thus, alterations in the pRB pathway seem to prevail in the aggressive form of
parathyroid neoplasms. Our results warrant further investigation of these cell
cycle regulators in order to determine their potential role as tumor markers in
parathyroid tumors.
PMID- 10671697
TI - Allelic imbalance at NBS1 is frequent in both proximal and distal colorectal
carcinoma.
AB - Nijmegen breakage syndrome (NBS) is a hereditary disorder involving chromosomal
instability, cancer risk and radiosensitivity. NBS carriers have an increased
risk of cancer, though the significance of mutations in the NBS1 gene in sporadic
cancer has not yet been investigated. Because the loss of NBS1 is associated with
increased chromosomal re-arrangements, and tumors of the colon are particularly
prone to chromosomal anomalies, we have begun to study the NBS1 locus in
colorectal cancer (CRC). DNA was isolated from 99 microdissected colorectal
tumors, and microsatellite markers flanking the NBS1 locus at 8q21.3 as well as
elsewhere on 8q were analyzed. Normal lymphocyte DNA from each patient served to
normalize the amplification of each allele, and a reduction of at least 35% in
the intensity of one allele was taken as evidence of allelic imbalance (AI). In
proximal and distal CRCs we found 25.9 and 36.2% with AI at 8q21.3, respectively.
AI in proximal CRC tended not to extend to marker D8S555 at 8q24.1, whereas in
distal CRC the region of AI frequently included all the informative markers. AI
of 8q21.3 was not associated with any clinical variable. These results suggest
that 8q21.3 contains a tumor suppressor gene involved in proximal CRC, possibly
NBS1. The large regions of AI make it difficult to determine the importance of AI
at the NBS1 locus in distal CRC.
PMID- 10671698
TI - High-resolution DNA flow cytometry in oral verrucous carcinoma.
AB - The classification of verrucous carcinoma as an entity unto itself or as a
variant of well differentiated squamous cell carcinoma is controversial. To
contribute new insights into the biological behavior of this rare tumor, we
applied DNA flow cytometry to three node-negative verrucous carcinomas of the
oral cavity. All tumors expressed a single aneuploid cell population. One of the
patients experienced three courses with local recurrence. All secondary tumors
retained the initially established aneuploid clone. The development of aneuploidy
is thus a cytogenetic event common to both verrucous and squamous carcinoma of
the oral cavity.
PMID- 10671699
TI - Homeopathic treatment of mild traumatic brain injury: A randomized, double-blind,
placebo-controlled clinical trial.
AB - BACKGROUND: Mild traumatic brain injury (MTBI) affects 750,000 persons in the
United States annually. Five to fifteen percent have persistent dysfunction and
disability. No effective, standard pharmacological treatment exists specifically
for this problem. We designed a pilot research project to study the clinical
effectiveness of homeopathic medicine in the treatment of persistent MTBI.
METHOD: A randomized, double-blind, placebo-controlled trial of 60 patients, with
a four-month follow-up (N = 50), was conducted at Spaulding Rehabilitation
Hospital (SRH). Patients with persistent MTBI (mean 2.93 years since injury, SD
3.1) were randomly assigned to receive a homeopathic medicine or placebo. The
primary outcome measure was the subject-rated SRH-MBTI Functional Assessment,
composed of three subtests: a Difficulty with Situations Scale (DSS), a Symptom
Rating Scale (SRS), and a Participation in Daily Activities Scale (PDAS). The SRH
Cognitive-Linguistic Test Battery was used as the secondary measure. RESULTS:
Analysis of covariance demonstrated that the homeopathic treatment was the only
significant or near-significant predictor of improvement on DSS subtests (P
=.009; 95% CI -.895 to -.15), SRS (P =.058; 95% CI -.548 to.01) and the Ten Most
Common Symptoms of MTBI (P =.027; 95% CI -.766 to -.048). These results indicate
a significant improvement from the homeopathic treatment versus the control and
translate into clinically significant outcomes. CONCLUSIONS: This study suggests
that homeopathy may have a role in treating persistent MTBI. Our findings require
large-scale, independent replication.
PMID- 10671700
TI - Measuring psychosocial recovery after traumatic brain injury: psychometric
properties of a new scale.
AB - OBJECTIVES: To determine the psychometric properties of the Sydney Psychosocial
Reintegration Scale (SPRS), an instrument developed to quantify disability and
handicap in persons with traumatic brain injury (TBI). DESIGN: Descriptive
correlational study. SETTING: Brain Injury Rehabilitation Unit and Brain Injury
Outpatient Clinic. PARTICIPANTS: Two samples, a "subacute" group (n = 20) and a
"long-term" group (n = 40), were studied to examine responsiveness (subacute
group), reliability, and validity (long-term group) of the SPRS. MAIN OUTCOME
MEASURE: The SPRS is a 12-item questionnaire measuring three domains of everyday
living commonly disrupted after severe TBI: occupational activities,
interpersonal relationships, and independent living skills. PROCEDURE: Patients
in the subacute group were rated with the SPRS by a clinician at admission to the
rehabilitation unit and again three months later or at discharge from the unit
(whichever occurred first). For individuals from the long-term group attending
the outpatient clinic, a close relative was interviewed with the SPRS and other
validating measures. The SPRS was readministered one month later. RESULTS:
Internal consistency of the SPRS was high (alpha coefficient = .90), as was
agreement between raters and stability over a one-month period (r(i) = .95 and
.90, respectively). Reliability and stability coefficients for the three domains
of the scale were also high, ranging from.86 to.94 for reliability and.77 to.93
for stability. Preliminary evidence for construct validity was established with a
number of standard instruments, with evidence of both convergent and discriminant
construct validity from the Sickness Impact Profile (SIP). The SPRS was sensitive
to group differences on the Glasgow Outcome Scale (GOS) and to changes occurring
during the period of active recovery. CONCLUSIONS: The results suggest that the
SPRS has sound psychometric properties, being a reliable, stable, sensitive, and
valid instrument. It is potentially useful in both clinical and research
settings.
PMID- 10671701
TI - Functional outcome of individuals with traumatic brain injury and lower extremity
deep venous thrombosis.
AB - OBJECTIVE: To determine the impact of acute lower extremity (LE) deep venous
thrombosis (DVT) on functional outcome after traumatic brain injury (TBI).
SETTING: Tertiary university medical center rehabilitation unit. SUBJECTS: Ninety
two TBI rehabilitation patients (46 patients with DVT and 46 patients without
DVT). Forty-six TBI patients with a diagnosis of LE DVT were 1:1 matched with non
DVT TBI patients. Matching criteria included: primary diagnosis of TBI, admission
Functional Independence Measure (FIM), Glasgow Coma Scale (GCS), and age. OUTCOME
MEASURES: FIM (admission, discharge, change, and efficiency), FIM subscores
(activities of daily living [ADL], mobility, cognition), length of stay ([LOS]
acute and rehabilitation), and discharge living disposition. DESIGN: Cohort study
utilizing prospectively collected data. DVT diagnoses were made upon
rehabilitation admission using color flow duplex Doppler ultrasonography.
Descriptive statistics were run on demographic variables. Analyses of variance
(ANOVAs) were performed on the sample with regard to outcome measures, including
FIM scores, FIM subscores, and LOS (acute and rehabilitation). RESULTS: No
significant between-group differences were found concerning LOS, rehabilitation
costs, FIM total, or FIM subgroup scores. Chi-squared analyses revealed
significant differences between groups with regard to discharge living
disposition (chi(2) = 4.7, P <.03). CONCLUSION: Lower extremity DVT does not
appear to interfere with functional outcome after TBI. The data suggest that this
patient population is appropriate for admission or continued participation in
acute inpatient rehabilitation, despite the presence of LE DVT.
PMID- 10671702
TI - Sex offending as a psychosocial sequela of traumatic brain injury.
AB - OBJECTIVE: To describe the nature and extent of sexual offending after traumatic
brain injury (TBI). DESIGN: Retrospective file review. SETTING: A brain injury
unit providing inpatient and outpatient rehabilitation services. PARTICIPANTS: A
review of five years of admissions to the Brain Injury Rehabilitation Unit (N =
477) identified a sample of 29 males who committed 128 incidents of sex
offending. MAIN OUTCOME MEASURES: A protocol to record data on demographic,
injury, radiological, and psychosocial variables and offending behaviors.
RESULTS: Of the total population of 445 clients with TBI, 6.5% (n = 29) were
identified as having committed some form of sexual offense. Alcohol was a factor
in only three (2.3%) of the incidents, and only two clients had a preinjury
history of sexual offending. The most common offenses were the "touching"
offenses, followed by exhibitionism and overt sexual aggression. Staff members
were the most common targets of the offenses, followed by members of the general
public, other people with TBI, and family members. CONCLUSIONS: Sex offending is
a significant clinical problem among a small minority of men after TBI. The
absence of alcohol and preinjury histories of sexual offending suggest that the
brain injury and contingent sequelae were a significant etiological factor
underlying the offenses. A number of implications for the clinical management of
clients with sexually aberrant behaviors is identified and discussed.
PMID- 10671703
TI - Neuropsychological significance of anosmia following traumatic brain injury.
AB - OBJECTIVES: To investigate the incidence of anosmia following traumatic brain
injury (TBI) using a standardized instrument and to test hypotheses that post-TBI
anosmics perform significantly more poorly than do post-TBI normosmics on
measures of executive skills and functional outcome. DESIGN: Prospective quasi
experimental between-groups design. PARTICIPANTS: Sixty-eight adults diagnosed
with TBI. SETTING: Brain injury rehabilitation program based at a Midwestern
medical center. MAIN OUTCOME MEASURES: University of Pennsylvania Smell
Identification Test (UPSIT), selected neuropsychological measures of executive
skills, the Disability Rating Scale (DRS), and the Community Integration
Questionnaire (CIQ). RESULTS: Forty-four subjects (65%) demonstrated impaired
olfaction; only 13 (30%) acknowledged smell dysfunction. Anosmic and normosmic
groups did not differ in demographics, IQ, chronicity, or admission Glasgow Coma
Scale (GCS). Anosmics had longer coma (P =. 01), more severe deficits in complex
attention (Trailmaking Test, Part B, P =.01), new learning/memory (California
Verbal Learning Test Trial V [CVLT-V], P =.001), and problem solving (Wisconsin
Card Sorting Test [WCST], P =.001), leading to greater functional impairment
(Disability Rating Scale [DRS], P =.003). No differences emerged on the CIQ.
CONCLUSIONS: Anosmia is a common sequela of TBI, although only a minority of
patients are aware of this deficit. Further, anosmics demonstrated greater
impairment in a variety of frontal-lobe mediated executive functions, as well as
greater functional disability.
PMID- 10671704
TI - Interaction of posttraumatic stress disorder and chronic pain following traumatic
brain injury.
AB - OBJECTIVE: To investigate the association between posttraumatic stress disorder
(PTSD) and chronic pain in patients who had sustained a severe traumatic brain
injury (TBI). DESIGN: Correlational relationships between pain variables and PTSD
measures were examined in a cohort study. SETTING: An adult tertiary care center
brain injury clinic. PATIENTS: Ninety-six persons with severe TBI. OUTCOME
MEASURES: The Posttraumatic Stress Disorder Interview (PTSD-I), a modified McGill
Pain Questionnaire, the Beck Depression Inventory (BDI), the General Health
Questionnaire (GHQ), the Community Integration Questionnaire (CIQ), the
Satisfaction with Life Scale (SWL), and the Coping Style Questionnaire (CSQ).
RESULTS: More persons with chronic pain reported PTSD than did those without
pain. The relationship between pain severity and depression, functional
adjustment, and satisfaction with life was mediated by severity of PTSD. Pain
severity was significantly associated with an avoidant coping style. CONCLUSIONS:
Effective rehabilitation of persons with chronic pain following severe TBI should
recognize the role of posttraumatic stress in the maintenance of dysfunctional
reactions. Specific interventions that address adaptive coping mechanisms to
reduce PTSD may enhance rehabilitation for persons with TBI who suffer chronic
pain.
PMID- 10671705
TI - Comparison of remedial and compensatory interventions for adults with acquired
brain injuries.
AB - OBJECTIVE: To examine the effects of a compensatory intervention versus a
remedial intervention for deficits in visual processing of adults with acquired
brain injuries (ABI). SETTING: A cognitive rehabilitation program at a large
comprehensive rehabilitation hospital in the New York City metropolitan area.
PATIENTS: Thirty adults with ABI were matched according to severity of injury,
gender, age, and time post-injury, and randomly assigned to the remedial or
compensatory group. INTERVENTIONS: The remedial intervention consisted of four 45
minute sessions (once weekly) of participation in computer tasks without
instruction in compensatory strategies. The compensatory intervention consisted
of four 45-minute sessions of instruction in the use of three internal
compensatory strategies, including verbalization, chunking, and pacing. MAIN
OUTCOME MEASURES: Pretest/posttest measures included three functional computer
tasks. Weekly measures included a computerized version of the Paced Auditory
Serial Addition Task (PASAT) and two computerized matching tasks. RESULTS: Both
groups exhibited statistically significant improvement of comparable degree on
posttests and weekly measures. Further analysis revealed that 80% of both groups
used compensatory strategies, regardless of intervention method. Those who used
strategies demonstrated better performance than those who did not. CONCLUSION:
The ability to use internal compensatory strategies may be a significant confound
in research examining the effects of the various cognitive rehabilitation
intervention methods.
PMID- 10671706
TI - Traumatic brain injury in the United States: A public health perspective.
AB - Traumatic brain injury (TBI) is a leading cause of death and disability among
persons in the United States. Each year, an estimated 1.5 million Americans
sustain a TBI. As a result of these injuries, 50,000 people die, 230,000 people
are hospitalized and survive, and an estimated 80,000-90,000 people experience
the onset of long-term disability. Rates of TBI-related hospitalization have
declined nearly 50% since 1980, a phenomenon that may be attributed, in part, to
successes in injury prevention and also to changes in hospital admission
practices that shift the care of persons with less severe TBI from inpatient to
outpatient settings. The magnitude of TBI in the United States requires public
health measures to prevent these injuries and to improve their consequences.
State surveillance systems can provide reliable data on injury causes and risk
factors, identify trends in TBI incidence, enable the development of cause
specific prevention strategies focused on populations at greatest risk, and
monitor the effectiveness of such programs. State follow-up registries, built on
surveillance systems, can provide more information regarding the frequency and
nature of disabilities associated with TBI. This information can help states and
communities to design, implement, and evaluate cost-effective programs for people
living with TBI and for their families, addressing acute care, rehabilitation,
and vocational, school, and community support.
PMID- 10671707
TI - Mapping variation in brain structure and function: implications for
rehabilitation.
AB - The recognition of structural and functional variability of the human brain
promoted the development of a system to organize and analyze the rapidly growing
body of knowledge acquired among diverse disciplines. The Human Brain Project
(HBP) was initiated and has evolved as a means of establishing an information
infrastructure through tools related to the emerging science of neuroinformatics.
This article will briefly describe the implications that such an endeavor has for
the field of traumatic brain injury (TBI) rehabilitation.
PMID- 10671708
TI - [Q.A.L.Y. index and assessment of cost efficiency of the cochlear implant in
acquired profound deafness].
AB - Cost utility analysis is a method of cost-effectiveness analysis which provides
results in terms of cost per quality-adjusted life-year (Q.A.L.Y.). This method
is progressively largely used for medical technology assessment. It permits cost
effectiveness comparisons between medical interventions. The cost per Q.A.L.Y. of
cochlear implant was determined in 30 adult patients suffering from acquired
profound deafness. This study indicates that this technology provides significant
improvements and is quite cost-effective. However, as far as profound deafness is
concerned, the reliability of Q.A.L.Y. needs to be improved.
PMID- 10671709
TI - [Signs and symptoms, etiologies and clinical course of parosmia + in a series of
84 patients].
AB - Eighty-four patients (72% females and 28% males) consulted between January 1995
and January 1998 for olfactory disorders with parosmia (erroneous olfactory
response to stimuli). Parosmia occurred immediately after or during the course of
acute rhinitis (n=70, 83%), head trauma (n=7, 9%), naso-sinus polyposis (n=5,
6%), chronic rhinitis (n=1) or frontal tumor (n=1). Quantitative and qualitative
olfactory disorders were analyzed and products producing the parosmia were
identified. The only cases where parosmia regressed concerned patients who
developed parosmia after acute rhinitis (n=28 cases, 33%). The prognosis of
parosmia appeared to be better when it was a secondary phenomenon: i) the
percentage of improvements was higher though not significant (41% versus 26.7%
compared with primary parosmia), ii) delay to improvement was shorter (8.4 +/-
2.1 months versus 14.5 +/- 4.4 months for primary parosmia, p<10(-4) ), iii)
there were no cases of persistent parosmia where quantitative disorders improved
(compared with 7 cases of persistent primary parosmia, p<0.05). In addition, the
prognosis of associated quantitative disorders was the same for both primary and
secondary parosmia. Only the delay to improvement appeared to be shorter in case
of secondary parosomia (though the difference was not significant). Products
which produced the parosmic perception were identified by nearly all the patients
(85%). The most frequently cited products were coffee, perfume, certain fruits
(melon, banana, citric fruits), tobacco or chocolate. All these products contain
tannic acid, a water-soluble polyphenol with many biological properties
(influence feeding habits and metabolism in the rate, antioxidant and
antimutagenic properties). Thus acid tannic could induce parosmic perception due
to its antioxidant properties susceptible of integrating the P-450 cytochromes of
the mucosal cells or olfactory neuroepithelium supporting cells.
PMID- 10671710
TI - [Orbital complications of sinusitis in adults].
AB - Orbital complications of sinusitis are rare in adults but delayed diagnosis is
vision and life threatening. We report our experience in 6 patients to present
clinical history, bacteriology and discuss the modality of treatment. There were
4 young men and 2 women, aged from 16 to 79 years old. Only one patient had an
immunocompromised underlying condition (HIV infection). Four patients had
preseptal abscesses and three post septal cellulitis or abscess (one patient had
preseptal abscess and post septal abscess and hematoma). Two patients had a
complete unilateral loss of light perception. Pathogens encountered were
Streptococcus species: 4, strict anaerobes: 1, Pseudomonas aeruginosa: 1 (patient
with AIDS). Patients recovered from infection with antibiotics in 6 and surgery
in 5 but sequellar blindness occurred in 2 patients. Our experience emphasizes
the necessity of antibiotic treatment in bacterial sinusitis and importance of
early diagnosis and appropriate management of complications.
PMID- 10671711
TI - [Swallowing disorders in unilateral recurrent laryngeal nerve paralysis].
AB - Swallowing difficulties in isolated recurrent laryngeal nerve paralysis are
rarely reported in the literature, although it is frequently mentioned in lesions
of both recurrent laryngeal and superior laryngeal nerves. The aim of this
prospective study was to evaluate the incidence of aspiration in patients with
unilateral recurrent laryngeal nerve paralysis after head and neck or thoracic
surgery. Eighteen patients were included and evaluated within the first week and
eleven two months postoperatively. Position, tone and tension of the vocal fold
as well as assessment of the glottic axis, arytenoid position and mobility,
laryngeal sensibility, status of the pyriform sinus and salivary stasis were
studied. Swallowing evaluation was performed using flexible fiberoptic
videolaryngoscopy during dry swallowing, thick cream and methylene blue liquid
swallowing. Five patients had symptomatic aspiration, one silent aspiration and
twelve patients had no aspiration. The type of regimen feeding used was
classified as a normal, mixed, or blended diet. Added specific treatment
performed was also described. We conclude that aspiration may occur in unilateral
recurrent laryngeal nerve paralysis and have to be systematically evaluated after
pneumomectomy, because adequate treatment can be proposed.
PMID- 10671712
TI - [Replacement of tracheo-esophageal Provox prosthesis].
AB - OBJECTIVES: To compare anesthesic techniques used between 1992 and 1997 at
Laennec Hospital for replacement by tracheo-esophageal Provox prosthesis: local
and general anesthesia. Theoretical financial cost for replacement was estimated
according to anaesthetic techniques. PATIENTS AND METHODS: Provox in situ
lifetime was calculated in 58 patients who underwent 115 and 49 replacements
under general and local anaesthesia respectively. Age, sex, surgical and
radiotherapy backgrounds, complications and anaesthetic techniques were studied
as potential factors correlated with Provox in situ lifetime. Theoretical
financial cost for replacement was estimated according to anaesthetic techniques.
RESULTS: In 1992, 12% of Provox prosthesis were inserted under local anaesthesia
and 54% in 1997. Provox in situ lifetime was either not influenced by anaesthetic
techniques or other factors under analysis. The theoretical financial cost was
estimated at 14, 341 FFrs and 6,048 FFrs for replacement under general and local
anaesthesia respectively. CONCLUSION: Due to increased control of health care
costs, we advocated local anaesthesia for Provox prosthesis replacement if
control endoscopy is not required.
PMID- 10671713
TI - [Thyroid cancer treatment].
AB - INTRODUCTION: Thyroid diseases are common although cancer is rare. There are some
controversial issues concerning the extent of surgical treatment of thyroid
cancer. MATERIALS AND METHODS: We have studied 614 cases of thyroidectomy
inducing 82 of mostly papillary and follicular thyroid cancers. RESULTS AND
DISCUSSION: We observed that differentiated thyroid cancer has a predilection for
the right lobe and one third of papillary tumors are multifocal. We have seen
that fine needle aspiration cytology is the most useful preoperative study.
Intraoperative frozen biopsy has a good specificity but sensitivity is low in our
series, specially for follicular neoplasms. The treatment in our series consisted
in total thyroidectomy and, in differentiated cancers, postoperative I-131.
Survival is very good for differentiated cancers. Prognosis is poor for
anaplastic carcinoma in the short term.
PMID- 10671714
TI - [Interest of free flaps for cranial base reconstruction].
AB - We describe our experience in treating 7 patients who underwent skull base
reconstruction with free flap (6 latissimus dorsi, 1 rectus abdominis) between
October 1996 and November 1998. Four patients underwent temporal bone resection
with auricular resection, 2 patients underwent anterior and middle cranial fossa
resection, 1 patient underwent frontotemporal resection. There have been no
failures of the free flaps and one cerebrospinal fluid leak. We advocate free
flap reconstruction after temporal bone resection with auricular resection, and
after anterior or middle cranial fossa resection when local flap options are not
available or with complex dead space.
PMID- 10671715
TI - [Endoscopic resection of the frontal sinus floor].
PMID- 10671716
TI - [ [In Process Citation]
PMID- 10671717
TI - [ [In Process Citation]
PMID- 10671718
TI - [Cardiac MR: morphological and functional imaging].
PMID- 10671719
TI - [Abdominal complications of Crohn's disease: CT features].
AB - Crohn's disease is characterized by transmural inflammation and chronic disorder
of the gastrointestinal tract. Abdominal complications of Crohn's disease are
frequent and quite variable and their diagnosis is commonly performed with CT.
The purpose of this article is to review the CT features of the abdominal
complications of Crohn's disease, including ileocolitis, abscess, phlegmon,
fistula, bowel obstruction, portal vein gas, colonic distention, as well as
urinary, hepatobiliary and pancreatic complications.
PMID- 10671720
TI - [A joint continuing medical education program for practitioners and radiologists:
a positive preliminary experience].
AB - PURPOSE: A common reflective continuing medical education (CME) approach has been
promoted by the French National CME Association (UNAFORMEC) and French Radiologic
Organizations to improve imaging prescriptions performed by general practitioners
(GP) as well as their relationships with radiologists to fit the best decision
resources for an optimal patient care. This new practice based CME is a
multidisciplinary learning model. MATERIALS AND METHODS: A learning model that
could satisfy GP and favor improved communication between them and radiologists
was elaborated. Two organization groups worked simultaneously during one year
before the first CME session could be achieved. This kind of CME involves a small
group (30 participants, 3/4 of general practitioners and 1/4 of radiologists),
and includes 3 sessions; on the basis of fictive medical situations, the first
one addresses to the formulation of a pertinent imaging prescription, including
data that are useful to the radiologist; the second one involves a critical point
of view of the imaging interpretation by the radiologist; the last one emphasizes
the communication between the patient, the GP and the radiologist. RESULTS: At
the present time two CMEs have been performed. Immediate participant appreciation
was enthusiastic and only some minor revisions were needed. Further evaluation
upon changes of practices has now to be made. CONCLUSION: This CME deserves to
provide not only a new practice learning model, but also a humanistic
perspective.
PMID- 10671721
TI - [Value of brain MR imaging in infants with a severe idiopathic apparent life
threatening event].
AB - OBJECTIVE: Prognostic value of a magnetic resonance imaging (MRI) scoring system
in infants with a severe apparent life threatening event (ALTE). METHODS: Ten
infants with an ALTE (aged between 6 and 31 weeks) were clinically graded
according to the PRISM score and evaluated with EEG, evoked potentials and MRI.
The 18 MRIs obtained were distributed in 3 classes according to the delay after
which they were obtained; class A (n=5): within the first 48 hours after the
event, class B (n=7): between day 3 and 8 and class C (n=6): between day 9 and
50. The 18 MRIs were evaluated retrospectively using a scoring system based on 3
categories of lesions: edema, basal ganglia injury and watershed injuries. Five
infants died between day 2 and day 15 after the event. The five surviving infants
had follow up neurodevelopmental testing after 38 to 77 months. RESULTS: There
was no correlation between the 5 MRIs of class A and the neurological outcome.
For the MRIs of class B and C, the scoring system can be of great value when
combined with the scores of EEG, EP and PRISM. CONCLUSIONS: The scoring system
for MRI performed within 48 hours after the event is falsely reassuring. MRI can
be helpful as early as 3 days after the event when combined with the score of the
electrophysiological investigations and the PRISM.
PMID- 10671723
TI - [Carney's triad: update and report of one case].
AB - The Carney's syndrome associates three different tumors on the same subject, a
young woman generally: a gastric leiomyosarcoma, a pulmonary chondroma and a non
adrenal paraganglioma. The authors report a new case of that unfrequent syndrome
of unexplained pathogeny.
PMID- 10671722
TI - [Lumbar intraspinal synovial cysts: imaging and treatment by percutaneous
injection. Report of thirteen cases].
AB - PURPOSE: The CT and MR imaging findings in 13patients with lumbar intra spinal
synovial cysts were retrospectively analysed and the results of facet
corticosteroid injection were evaluated. PATIENTS AND METHODS: Over a 7 year
period, 13patients with radicular pain were identified as having lumbar intra
spinal synovial cysts. They ranged from 42 to 87 years of age. All patients were
evaluated by CT without contrast material and underwent facet arthrography
associated with corticosteroid injection and CT arthrography. MR imaging was
performed in all patients either before or after percutaneous treatment. CT scans
and MR images were reviewed and patient outcome was evaluated at 1and 6month
followup. RESULTS: CT scan revealed a cystic structure adjacent to a degenerated
facet joint in 9 patients (69% sensitivity). MRI showed more accurately the cyst
on T2 weighted and/or axial images. Complete or good relief of radicular pain and
functional restrictions were achieved in 9 patients (69%) at 1 month follow up,
still to be found in 6patients (46%) at 6months. CONCLUSION: In patients with
radiculopathy and facet degenerative changes, intra spinal synovial cysts must be
looked for. Facet corticosteroid injection is a useful alternative to surgical
removal.
PMID- 10671724
TI - [Atypical sonographic findings of bacterial colitis].
AB - We report three pediatric cases of infectious colitis that were misinterpreted on
US examination as Crohn's disease. These colitis were limited to the left colon
and presented with transmural hypoechoic thickening of the wall and homogenous
hyperechoic appearance of the surrounding fat.
PMID- 10671725
TI - [Angiosarcoma of the breast. Radiological aspects. About one case].
AB - Angiosarcoma of the breast in an uncommon entity. The authors report a well
documented case of angiosarcoma. The patient, a 23 years old woman, had a
voluminous mass of the left breast without inflammation. The evolution was
rapidly fatal. Physical examination revealed a large painful breast mass with
purplish discoloration cutaneous area in front of the lesion. The palpation
revealed a thrill. The mammography had shown an area of increased density in the
left breast. A complementary ultrasound examination detected a well circumscribed
voluminous mass with hypoechogenic heterogenous echostructure. The Doppler
examination detected a venous blood flow in the tumor. This finding was
compatible with vascular tumor as angioma or angiosarcoma. The angioscanner
showed a peripheral vascular enhancement and a centripetal diffusion of the
contrast product. This vascular kinetic is seen commontly in the angioma.
Magnetic resonance imaging in the T1 and T2 relaxation times detected an
intermediate signal mass with bleeding areas. The patient had had a mastectomy
and the histopathologic examination confirmed the diagnostic of angiosarcoma. The
radiological aspacts of angiosarcoma of the breast are discussed depending on the
literature data.
PMID- 10671726
TI - [Cortical septic osteitis: two cases].
AB - Cortical septic osteitis is defined as a predominant or exclusive infection of
the cortex which may lead to diagnosis pitfalls. With the two cases presented
here, principal radiological features allowing a correct diagnosis are recalled.
PMID- 10671727
TI - [What is it? Left-sided appendicitis].
PMID- 10671728
TI - [Percutaneous osteosynthesis of pelvic fractures with CT control].
AB - Pelvis fractures, most often multiple, are frequently unstable. Orthopedic
treatment is hardly bearable (traction in bed sometimes up to 45 days), the open
reduction and internal fixation (ORIF) is heavy. Percutaneous fluoroscopy guided
fixation lacks precision in depth. Percutaneous screw fixation with CT scan
control answers these drawbacks and represents a quick solution, with few hazard
when performed by a trained team and allows a very early resumption of standing.
PMID- 10671729
TI - [Resection of osteoid osteoma].
PMID- 10671749
TI - Embryonic stem cells and nuclear transfer strategies. Present state and future
prospects.
PMID- 10671750
TI - A role for epithelial-mesenchymal interactions in tail growth/morphogenesis and
chondrogenesis in embryonic mice.
AB - Neurulation involves development from primary germ layers before any
differentiation of embryonic mesenchyme. Subsequently, secondary organogenesis is
via epithelial-mesenchymal interaction. It is unclear whether formation of the
caudal body axis and tail bud in vertebrate embryos is by temporal and causal
extension of primary neurulation, by secondary neurulation, or by secondary
induction (epithelial-mesenchymal interactions) as seen in organogenesis of the
limb buds, kidneys, heart and other embryonic regions. Reports of a ventral
ectodermal ridge (VER) associated with tail bud development in rodent embryos
imply that tail bud development may share features with limb bud development, in
which the apical ectodermal ridge (AER) directs limb bud outgrowth and skeletal
patterning. Organ culture or grafting to the chorioallantoic membranes of host
chick embryos, of tail bud mesenchyme with or without tail epithelium,
demonstrates that both survival and growth of tail mesenchyme depend on the
presence of tail epithelium. Initiation of chondrogenesis of tail mesenchyme was
similarly dependent on tail epithelium until 10.5 days of gestation, which is
when the VER is at its maximal extent. Initiation of myogenesis was independent
of the presence of tail epithelium. These results are discussed in relation to
the similarity of tail bud to limb bud developed, and to the different mechanisms
employed in differentiation of the cranial and caudal ends of vertebrate embryos.
Secondary induction of the caudal body region is argued to be fundamental in
vertebrate embryogenesis.
PMID- 10671751
TI - Leptin expression during the differentiation of subcutaneous adipose cells of
human embryos in situ.
AB - In this study, the immunocytochemical expression of leptin in the developing
subcutaneous tissue of human embryos at 6-10 weeks of gestation was investigated
using the avidin-biotin peroxidase method. Immunocytochemical staining for leptin
was observed in the cytoplasm of the differentiating preadipose cells. The other
cells present in the embryonal subcutis (mesenchymal cells differentiating into
fibroblasts, fibrocytes, endothelial cells) were leptin-negative. The developing
skin epithelium lying above it and the blood cells in the capillaries also did
not express leptin. The results suggest that the leptin is produced by the
developing fat cells from the beginning of lipidogenesis and differentiation. It
possibly acts as a hormonal factor regulating the embryonal growth, development
and body fat storage.
PMID- 10671752
TI - Intraepithelial leucocytes in the bovine uterine tube.
AB - The epithelium of the uterine tube consists of ciliated cells and secretory
cells. Basal cells are a third cell type observed in tubal epithelium and they
are located principally in the basal part of the epithelium. The objectives of
this study were to characterize these basal cells in normal and superovulated
heifers and to determine whether they participate in the replacement of the
ciliated and secretory cell populations. All heifers received cloprostenol (PG)
to induce oestrus (day 0). Superovulated heifers received 24 mg pFSH at doses of
4.5, 3.5, 2.5 and 1.5 mg given twice daily. Control and superovulated heifers
were slaughtered on days 1, 3, 5 and 7 of the oestrous cycle. Another group of
normal cycling heifers was slaughtered on days 2-3 and 11-13 of the oestrous
cycle and used for immunocytochemistry. Samples from ampulla, pre-isthmus and
isthmus of the uterine tube were collected and processed for light and
transmission electron microscopy. Quantitative examination by light microscopy
showed that there was a significant difference in the number of basal cells
between the regions of the heifers' uterine tube. On the basis of ultrastructure
two populations of basal cells were observed. One (type I) had a nucleus with
much condensed heterochromatin and very sparse cytoplasmic organelles. The second
cell (type II) had a nucleus with heterochromatin typically clumped around the
nuclear envelope. Its cytoplasm contained many organelles including a number of
lysosomes. The ultrastructural features of these cells were similar in all
regions and at all days of the oestrous cycle examined. Immunocytochemistry
revealed that type I basal cells were lymphocytes and type II basal cells were
macrophages.
PMID- 10671753
TI - Immunocytochemical and immunoelectron-microscopic study of somatotrophs in ICR
and nonobese diabetic mice.
AB - Somatotrophs (GH cells) were classified immunoelectron microscopically into three
types mainly on the basis of the size of secretory granules in the mouse
pituitary of ICR strain. Type I cells contained large secretory granules. Type II
cells contained both large secretory granules and small secretory granules. Type
III cells contained small secretory granules. All three types of GH cells were
found from the neonatal ages to adult. The relative proportion of three types did
not change with age, and no sex differences in the relative proportion of the
cell types were detected. Type I cells predominate in all age groups observed. In
60-day-old male mice percentages of each type were as follows: type I 93.7 +/-
0.1%, type II 5.4 +/- 0.8%, and type III 0.9.0 +/- 0.4% (n = 5), and in 60-day
old female mice type I 95.2 +/- 0.1%, type II 2.7 +/- 0.5%, and type III 2.1 +/-
0.9% (n = 5). The maximum diameters of the large secretory granules increased
from 7 to 60 days of age. The small secretory granules similarly increased in
size in female mice, but those in male mice did not change. In the diabetic
female mice of the nonobese diabetic (NOD) strains, GH cells in diabetic mice
became smaller, and the number and size of secretory granules decreased,
indicating diminished GH secretion. However, the relative proportion of each
subtype of GH cells did not differ irrespective of the occurrence of diabetes.
PMID- 10671754
TI - Distribution of interglobular dentine in human tooth roots.
AB - The present study was designed to examine the distribution of interglobular
dentine in human tooth roots. The material comprised 17 teeth, of which 3 were
premolars extracted for orthodontic reasons from children 10-12 years of age and
the other teeth (4 incisors, 3 canines and 7 molars) were extracted for
periodontitis from individuals aged 32-63 years. All teeth were free of caries
and cervical dentine defects. Ground sections of the teeth cut longitudinally
were stained with basic fuchsin and observed by fluorescence and confocal
microscopy as well as transmitted light microscopy. Basic fuchsin stained the
dentinal tubules, interglobular dentine and the granular layer of Tomes. These
structures appeared intense blue to faint violet with transmitted light
microscopy, whereas their staining displayed intense fluorescence with
fluorescence microscopy. Therefore, the interglobular dentine could be detected
more sensitively with fluorescence and confocal microscopy than with transmitted
light microscopy. Typical interglobular dentine was present in coronal dentine in
most of the teeth. In the radicular dentin, position and size of the
interglobular dentine was different among the teeth examined. Most of the teeth
had the interglobular dentine in the cervical part of the roots (type A). Two
premolars displayed the interglobular dentine in the coronal half of the root
(type B). The types A and B contained large interglobular areas. A small amount
of interglobular dentine was restricted to the apical half of the roots of two
canines and one molar (type C). In contrast to types A and B which were seen at
both labial or buccal and lingual sides of roots, the interglobular dentine of
type C was seen only at one side, labial or lingual. Some of the tooth roots did
not show any interglobular dentine (type D). Most of the incisors, canines and
premolar were types A, B, and C, respectively, and the molars were mixed types A,
C, and D. These results suggest that the factors affecting dentinogenesis during
root formation are unique for each tooth.
PMID- 10671755
TI - Effects of muscle contraction on the load-strain properties of frog aponeurosis
and tendon.
AB - The mechanical properties of the frog semitendinosus (ST) tendon and aponeurosis
were measured during passive tensile loading to a force equal to ST maximum
tetanic tension and during active isometric muscle contraction. During active
contraction, both the tendon and aponeurosis regions initially strained at rates
exceeding 400%/s while near the end of the muscle contraction, strain rates were
nearly zero. At this point, the strain in the tendon region was equal to that
observed during slow passive loading to the same tension level. However, for the
aponeurosis, even near the zero strain rate, strain at the end of the active
contraction was significantly below that observed during slow passive loading (p
< 0. 001). Specifically, when aponeurosis strain rate was almost zero,
aponeurosis strain was 13.8 +/- 3% (means +/- SEM, n = 10), which was
significantly below that measured during passive loading (23.7 +/- 5%) suggesting
that active contraction actually altered aponeurosis material properties. These
data demonstrate that, while the tendon and aponeurosis regions have different
passive biomechanical properties and both demonstrate viscosity typical of other
connective tissues, the aponeurosis region of the frog ST actually changed its
intrinsic properties during muscle contraction. Thus, extrapolation of
biomechanical data obtained at nonphysiological strain rates or under conditions
where the muscle-tendon junction has been interrupted should be made with
caution.
PMID- 10671756
TI - Evaluation of neutropenic fever: value of serum and plasma parameters in clinical
practice.
AB - Treatment-related mortality due to infectious complications following potentially
curable aggressive chemotherapy remains a major clinical problem. However, the
diagnosis of neutropenic infections is difficult. Although it is common practice
to institute empirical broad-spectrum antibiotics in neutropenic fever, liberal
use of antibiotics may contribute to increasing resistance and superinfection
such as systemic mycosis. Clinicians are searching for a highly specific and
sensitive marker indicating early infection. Serum concentrations of several
acute-phase proteins (C-reactive protein, serum amyloid A), proinflammatory
cytokines (TNFalpha, IL-1, IFNgamma, IL-6, IL-8), soluble adhesion molecules
(soluble E-selectin, vascular cell adhesion molecule 1, intercellular adhesion
molecule 1) and more recently procalcitonin have been investigated as to whether
these may contribute to identifying infections as the cause of neutropenic fever.
Unfortunately, at present, based on the small and inconsistent amount of data
available from the literature one is tempted to conclude that the predictive
values of all these parameters are too low to influence the clinically based
initial treatment decisions in patients with neutropenic fever.
PMID- 10671757
TI - Flucytosine: correlation between toxicity and pharmacokinetic parameters.
AB - Flucytosine (5-fluorocytosine, 5-FC) is a systemic antimycotic drug the major
toxicities of which are bone marrow depression and hepatotoxicity. The purpose of
this observational and retrospective study was to assess a possible relationship
between toxicity and 5-FC pharmacokinetics within a group of 53 intensive care
unit patients. The presented results reveal that thrombocytopenia is associated
with a decreased 5-FC clearance and that the thrombocyte nadir is linearly
related to the 5-FC clearance. Furthermore, patients experiencing 5-FC levels
exceeding 100 mg 5-FC/l were found to be at a higher risk of developing
thrombocytopenia and hepatotoxicity as compared to those not exceeding this
level.
PMID- 10671758
TI - In vitro and in vivo antibacterial activities of biapenem in the fields of
obstetrics and gynecology.
AB - Biapenem is a new injectable carbapenem antibiotic which has favorable
pharmacokinetic properties, and is stable to hydrolysis by dehydropeptidase I.
Biapenem inhibited more than 90% of clinical isolates of Streptococcus
agalactiae, Escherichia coli, Peptostreptococcus magnus, Bacteroides fragilis and
Prevotella bivia at the concentration of 3.13 mg/l. The MIC(90) of biapenem
against Pseudomonas aeruginosa was lower than that of panipenem, equivalent to
that of imipenem, and greater than that of meropenem. The in vivo efficacy of
biapenem was evaluated using the experimental infection model of uterine
endometritis. The accumulation of neutrophils in the uterus in the biapenem-
treated group was less marked than in the nontreated group, as well as
bacteriological response. These results suggest that the new antimicrobial agent
biapenem might be useful for the treatment of polymicrobial infections in the
fields of obstetrics and gynecology.
PMID- 10671759
TI - Fluconazole inhibits pseudohyphal growth in Saccharomyces cerevisiae.
AB - The ergosterol-depleting antifungal fluconazole, when given at concentrations not
affecting growth, inhibited pseudohyphal growth in Saccharomyces cerevisiae, a
genetically tractable fungus closely related to the human pathogen Candida
albicans. These results suggest that S. cerevisiae could serve as a useful
genetic system to study the morphogenetic effects induced by azoles in pathogenic
yeast.
PMID- 10671760
TI - In vitro susceptibilities of enterococcal blood culture isolates from the Hamburg
area to ten antibiotics.
AB - Treatment of enterococcal infections is often difficult because of intrinsic and
acquired resistance to a variety of antimicrobial agents. Between January 1993
and May 1997, enterococci were isolated from blood cultures of 117 patients at
the Institute of Medical Microbiology and Immunology, University Hospital
Eppendorf, Hamburg, Germany. Eightynine (76%) isolates were phenotypically
identified as Enterococcus faecalis, and 24 (21%) as Enterococcus faecium. All E.
faecalis isolates, but only 17% of the E. faecium isolates were susceptible to
ampicillin. Two E. faecium isolates (8%) but no E. faecalis were vancomycin
resistant (vanA genotype). Quinupristin/dalfopristin shows a high degree of
susceptiblity of E. faecium (79%) and may be suitable for the therapy of
infections caused by glycopeptide-resistant E. faecium strains.
PMID- 10671761
TI - Effect of Varidase (streptokinase) on biofilm formed by Staphylococcus aureus.
AB - Staphylococcus aureus forms a fibrin-rich biofilm in the presence of plasma which
is highly resistant to attack by the human immune system and to chemotherapy.
Varidase, composed mainly of streptokinase, is used for hydrolyzing clots. In
this study, we attempted to destroy the biofilm of S. aureus with Varidase and to
apply this drug in the treatment of staphylococcal infections. Four clinical
isolates were used in the experiments. These organisms formed a several
millimeter-thick biofilm on type IV collagen coated coverslips in trypticase soy
broth containing 50% human plasma. The biofilm was composed of bacterial cell
which adhered to fibrillar fibers and of sediment derived from plasma. 10,000
U/ml of Varidase, the dose which is used clinically, removed the sediment and
reduced the number of live bacteria in biofilms to less than 20% of control. 200
U/ml of Varidase was also effective against biofilms of the organisms. An equal
combination of Varidase and ofloxacin had an additive effect on the bacteria. The
results of this study demonstrate that Varidase is highly effective in destroying
biofilms of S. aureus in vitro and suggest that this drug would be useful for
treating staphylococcal infections.
PMID- 10671762
TI - Efficacy of amikacin, ofloxacin, pefloxacin, ciprofloxacin, enoxacin and
fleroxacin in experimental left-sided Pseudomonas aeruginosa endocarditis.
AB - The efficacies of amikacin, ofloxacin, pefloxacin, ciprofloxacin, enoxacin and
fleroxacin, each as monotherapy, were evaluated in a rabbit model of induced left
sided Pseudomonas aeruginosa endocarditis. Therapy started 48 h after infection
and lasted 5 days. All agents were given intramuscularly; amikacin at 7 mg/kg/12
h, and each quinolone at 35 mg/kg/12 h. All animals survived except for 1 of the
group that received amikacin, and 2 of the untreated control group. No sterile
vegetations were found in the untreated group and the group of fleroxacin, while
3 animals from the amikacin, ofloxacin, and enoxacin groups, and 2 from the
ciprofloxacin and pefloxacin groups had sterile vegetations. All agents used
significantly reduced the number of CFU per gram of vegetation versus untreated
controls. Enoxacin and ciprofloxacin were equipotent and more effective than
pefloxacin, ofloxacin and amikacin. Fleroxacin had a weaker activity.
PMID- 10671763
TI - Bactericidal activity of gatifloxacin (AM-1155) against Pseudomonas aeruginosa
and Enterococcus faecalis in an in vitro bladder model simulating human urinary
concentrations after oral administration.
AB - The bactericidal activity of gatifloxacin, a new 6-fluoro-8-methoxy quinolone,
was determined in a dynamic in vitro model mimicking complicated lower urinary
tract infection. Strains of Pseudomonas aeruginosa and Enterococcus faecalis with
different susceptibility were exposed to changing gatifloxacin concentrations,
simulating human urinary concentrations afer oral treatment with 200 mg twice
daily for 3 consecutive days. Bacterial numbers of P. aeruginosa (minimal
inhibitory concentrations, MIC: < or =32 microg/ml) and of E. faecalis (MIC: 16
microg/ml) were reduced to undetectable levels during exposure. For the strains
with lower susceptibility, gatifloxacin showed bactericidal activity, but
eradication was not complete. Thus, in a complicated urinary tract infection
model, breakpoint MICs of gatifloxacin for uropathogenic organisms were presumed
to range from 16 to 32 microg/ml. At least 86% of recent clinical isolates of P.
aeruginosa and E. faecalis were inhibited at its breakpoint MIC. These results
suggest that gatifloxacin may be useful in the treatment of urinary tract
infections.
PMID- 10671764
TI - Effects of antibiotics on adherence of Pseudomonas aeruginosa and Pseudomonas
fluorescens to A549 pneumocyte cells.
AB - The aim of this study was to evaluate the effect of antibiotics at subminimal
inhibitory concentrations (sub-MIC) on fluorescent pseudomonas adherence to A549
pneumocyte cells. Pseudomonas fluorescens MF0 isolated from contaminated raw milk
and Pseudomonas aeruginosa NK125502 isolated from a cystic fibrosis patient's
lung adhered to A549 cells. As previously shown for P. aeruginosa, P. fluorescens
bound to A549 cells in a dose-dependent manner over a wide range of bacterial
concentrations. Bacterial growth in the presence of polymyxin B or gentamicin at
MIC/2 had no effect on the adherence of NK125502 and MF0 to A549 cells. Instead,
MIC/2 and MIC/8 of cefsulodin or chloramphenicol decreased the adherence of the
two strains. A decrease in MF0 adherence was also observed with cefsulodin at
MIC/32. We conclude that, in addition to their antibacterial activity, cefsulodin
and chloramphenicol could be effective in preventing Pseudomonas adherence to
respiratory epithelium.
PMID- 10671765
TI - In vitro effects of meropenem and imipenem/cilastatin on some functions of human
natural effector cells.
AB - Meropenem, a new carbapenem antibiotic, was assessed to evaluate its effects on
some functional parameters of human polymorphonuclear (PMN) and natural killer
(NK) cells in comparison with imipenem/cilastatin. Both drugs significantly
inhibited PMN phagocytosis and chemotaxis at concentrations of 2,000 and 4,000
microg/ml. They affected PMN microbicidal activity, evaluated against Candida
albicans, only at 4,000 microg/ml. A study of the effects of both drugs on
peripheral NK populations and the human NK line (NK-92) showed that even at 4,000
microg/ml there was no effect on antitumor activity. These data indicate that
meropenem can reduce some PMN antimicrobial functions only at very high
concentrations like imipenem/cilastatin, whereas no concentration influenced NK
activity.
PMID- 10671766
TI - In vitro cytotoxicity of three 4,9-diazapyrenium hydrogensulfate derivatives on
different human tumor cell lines.
AB - DNA intercalating agents interfere with DNA's role as a template in replication
and transcription by inserting an intercalator molecule between adjacent base
pairs. We synthesized three potential novel intercalators, 4,9-diazapyrenium
hydrogensulfate derivatives: 5, 10-diphenyl-4,9-dimethyl-4,9-diazapyrenium
hydrogensulfate (FDAP), 4, 9-dimethyl-4,9-diazapyrenium hydrogensulfate (GDAP)
and 2,4,7, 9-tetramethyl-4,9-diazapyrenium hydrogensulfate (MDAP) and tested
their biological effects in vitro on four human tumor cell lines (SKBr3: breast
carcinoma, HeLa: cervical carcinoma, CaCo2: colon carcinoma and SW620: poorly
differentiated cells from lymph node metastasis of colon carcinoma). Cytotoxic
effects on cell growth and viability were determined using tetrazolium dye (MTT)
assay. DNA synthesis and proliferation of treated cells were studied by the
[(3)H]-thymidine incorporation test. DNA fragmentation was analyzed by agarose
gel electrophoresis. The growth inhibitory effect was cell-specific and dose
dependent. The most pronounced antiproliferative effect was observed on SKBr3
cells for FDAP (10(-5) M) 91.8%, for MDAP (10(-5) M) 85.3% and on SW620 cells for
GDAP (10(-5) M) 65.3%. The DNA ladder fragmentation of treated HeLa and SKBr3
cells, as a hallmark of apoptosis, was observed. Based on specific DNA
fragmentation, morphological changes (reduced cell volume, round cell shape,
condensed chromatin) and growth inhibition of treated human tumor cells we
conclude that tested substances induced apoptotic cell death.
PMID- 10671767
TI - Adequate levofloxacin treatment schedules for uterine cervicitis caused by
Chlamydia trachomatis.
AB - The in vivo efficacy of levofloxacin (LVFX), one of the most standard new
quinolone antimicrobial agents, in the different treatment schedules of Chlamydia
trachomatis uterine cervicitis in women was evaluated. Cervical C. trachomatis
was detected by polymerase chain reaction. LVFX at a dosage of 300 mg t.i.d. for
5, 7 and 14 days was orally administered to 18, 33 and 35 Japanese patients,
respectively. The eradication rate and the recurrence rate in the different
treatment schedules of C. trachomatis were evaluated. The eradication rate in 5-,
7- or 14-day cases was 44.4, 87.9 or 88.6%, respectively. The recurrence rate of
5-, 7- or 14-day cases was 50.0, 0 or 0%, respectively. Seven-day treatment with
LVFX is adequate for and effective in C. trachomatis uterine cervicitis.
PMID- 10671768
TI - Barrett's esophagus: disregulation of cell cycling and intercellular adhesion in
the metaplasia-dysplasia-carcinoma sequence.
AB - The incidence of both esophageal adenocarcinoma and Barrett's esophagus, a
premalignant condition predisposing to this cancer, is rising rapidly. There is
growing evidence that both of these conditions are related to the reflux of acid
and bile into the esophagus. This results in inflammation and cell damage which
initiates a sequence of events termed the metaplasia-dysplasia-carcinoma sequence
in which the squamous epithelium is replaced by columnar epithelium exhibiting
increasing degrees of dysplasia and overt malignancy. This sequence of events is
underpinned by changes in cell cycling, such as accumulation of p16 and p53
mutations and increased cyclin D1 activity. Progression along this pathway is
characterized by changes in intercellular adhesion, in particular, loss of
adenomatous polyposis coli, reduced cadherin expression and increased catenin
phosphorylation resulting in its nuclear translocation. Herein, we detail these
molecular defects and propose how they may interrelate in an ordered progression
in the development of esophageal adenocarcinoma.
PMID- 10671769
TI - Gastroesophageal reflux disease: prevalence, clinical, endoscopic and
histopathological findings in 1,128 consecutive patients referred for endoscopy
due to dyspeptic and reflux symptoms.
AB - BACKGROUND AND AIMS: Gastroesophageal reflux disease (GERD) reportedly has
increased in prevalence while Helicobacter pylori infection and peptic ulcer
disease have been on the decrease. The aim of the present study was to examine
the prevalence of GERD as well as the clinical, endoscopic and histologic
variables that associate with GERD in patients referred for endoscopy. PATIENTS
AND METHODS: The study population was drawn from 1,562 consecutive patients
referred for endoscopy. The exclusion criteria were previous H. pylori
eradication, gastric surgery, anemia and weight loss. Thus 1,128 patients were
enrolled in the present study. RESULTS: Of the 1,128 patients, 199 (18%) were
referred for endoscopy due to heartburn and/or regurgitation. GERD, defined as
chronic (>6 months) heartburn and/or regurgitation with or without erosive
esophagitis, Barrett's esophagus, esophageal ulcer or stricture, was detected in
248 (22%) patients. Of the 248 GERD patients, 81 (33%) had endoscopy-negative
GERD, but of those aged <50 years (n = 67), 57 (85%) were endoscopy-negative. The
overall incidence of GERD was 307 per 100,000 population/year and that of
endoscopy-positive GERD 207/100,000/year. The positive and negative predictive
values of heartburn and regurgitation for endoscopy-positive GERD were 0.37 (95%
CI 0.31-0.44) and 0.90 (95% CI 0.88-0.92), respectively. Independent risk factors
for GERD were male sex (OR 1.9, 95% CI 1.3-2.7), previous medication for upper
gastrointestinal symptoms (OR 2.7, 95% CI 1.7-4.1), the use of nonsteroidal anti
inflammatory drugs (NSAIDs; OR 2.0, 95% CI 1.3-3. 0), histologic esophagitis (OR
2.2, 95% CI 1.5-3.2) and incomplete intestinal metaplasia at the gastroesophageal
junction (OR 1.7, 95% CI 1.0-3.1). Chronic gastritis was protective against GERD
(OR 0.7, 95% CI 0.5-0.9). No association was observed between GERD and H. pylori
infection. The risk of patients aged <50 years (n = 407) of having major lesion
(Barrett's esophagus, esophageal stricture, peptic ulcer, esophageal/gastric
carcinoma) was significantly lower than that of patients aged >50 years (n = 721;
OR 0.5, 95% CI 0.3-0. 9, p = 0.01). CONCLUSIONS: The correlation between reflux
symptoms and endoscopy-positive GERD is poor and most GERD patients aged <50
years have endoscopy-negative GERD. The use of NSAIDs is a risk factor for GERD,
whereas chronic gastritis, but not H. pylori infection, may protect against GERD.
Incomplete intestinal metaplasia at the gastroesophageal junction is associated
with GERD.
PMID- 10671770
TI - In search of immunogenic Helicobacter pylori proteins by screening of expression
library.
AB - BACKGROUND: Prevention of Helicobacter pylori infection may help to control
related gastritis, peptic ulcer and cancer. Of the possible preventive measures,
immunization was successfully employed in various animal studies. However, no
immunization protocol has been accepted for humans. A better characterization of
the immune response against the pathogen may be required before a human vaccine
is developed. AIM: To identify bacterial proteins which induce an immune response
in infected humans or H. pylori-immunized rabbits. METHODS: An expression library
of H. pylori genes was screened with sera from infected humans and from immunized
rabbits. Positive clones were partially sequenced and identified on the basis of
a homology search of a H. pylori genome database. Encoded proteins were expressed
directly from positive clones and analyzed by SDS-PAGE/Western blot techniques.
RESULTS: 114 positive clones were isolated: 79 by screening with human sera and
35 by screening with rabbit sera. Western blot analysis demonstrated that
selected clones encoded one or more strongly immunoreactive proteins. 64 clones
selected with human sera had no counterparts among clones from screening with
rabbit serum. 13 of these clones encoded a total of 21 unknown H. pylori
proteins. 17 clones selected with rabbit sera were not immunostained with human
sera. They represent 2 various regions of the H. pylori genome which encoded 3
bacterial proteins of unknown function. CONCLUSIONS: Screening of H. pylori
expression library identified immunogenic proteins - potential vaccine antigens.
PMID- 10671771
TI - 40- to 100-kD protein(s) of Helicobacter pylori stimulate DNA synthesis in
epithelial cell lines without affecting apoptosis.
AB - BACKGROUND: Previous in vitro studies have demonstrated that water extracts and
sonicates of Helicobacter pylori increase DNA synthesis in a small intestinal
epithelial cell line. The aim of this study was to identify mitogenic factor(s)
in a water extract of a H. pylori strain and to examine their effects on DNA
synthesis and apoptosis in vitro. METHODS: IEC-6 and FHs 74 cells were incubated
for 24 h with different dilutions of a water extract of H. pylori (cytotoxic
strain 88-23) or with 6 protein fractions obtained by gel filtration. Cells were
labeled with tritiated thymidine and processed for autoradiography. DNA synthesis
was evaluated by the labeling index (LI%). The proportion of IEC-6 cells
undergoing apoptosis and/or necrosis was evaluated by flow cytometry using
fluorescein isothiocyanate (FITC)-labeled annexin-V and propidium iodide. In
vitro caspase activity was also determined as an alternative method for detection
of apoptosis. RESULTS: The water extract of H. pylori 88-23 markedly increased
DNA synthesis in both epithelial cell lines (p < 0.01). A marked stimulation of
DNA synthesis was also observed in IEC-6 cells incubated with fraction II-
containing proteins of a molecular weight ranging between 40 and 100 kD (p <
0.01). A lesser stimulation of DNA synthesis was observed in cells incubated with
higher concentrations of the other protein fractions (p < 0.01). Neither the
water extract of H. pylori 88-23 nor the protein fraction II (40-100 kD) induced
apoptosis in IEC-6 cells. CONCLUSION: A water extract of H. pylori 88-23 and a
protein fraction containing proteins with molecular weights of 40-100 kD
stimulate DNA synthesis in a rat and human small intestinal cell line. Apoptosis
was unaffected by the water extract and by protein fraction II, which indicate
that the H. pylori-derived mitogen(s) have the capacity to directly enhance
epithelial cell proliferation in vitro.
PMID- 10671772
TI - Increased mitogen-activated protein kinase activities stimulated with interleukin
1-beta and mechanism(s) of the kinase signaling pathways in rat gastric
epithelial cells.
AB - Interleukin (IL)-1beta, a multifunctional cytokine, is associated with
inflammatory gastric mucosa, but the responses of gastric epithelial cells
stimulated by IL-1beta are not known. We determined whether IL-1beta activates
the two subfamilies of mitogen-activated protein (MAP) kinases, extracellular
signal-regulated kinases (ERKs) and c-Jun NH(2)-terminal kinases (JNKs), in rat
gastric epithelial cells (RGM1) using in-gel kinase assays. In addition, we
examined the mechanism(s) underlying their signaling pathways and the effect on
proliferation of these cells. IL-1beta (0-5 x 10(3) pg/ml) dose dependently
induced activation of ERKs (p44ERK and p42ERK) and JNKs (p46JNK and p55JNK) in
RGM1 cells; maximal activities were attained with 1,000 pg/ml of IL-1beta. These
activities were increased with time, and were maximal 20 min after stimulation
with IL-1beta (100 pg/ml). Pretreatment with neutralizing antibody against IL
1beta inhibited IL-1beta-induced activation of ERKs and JNKs. Genistein (100
microM), a tyrosine kinase inhibitor, and GF109203X (2 microM), a protein kinase
C inhibitor, inhibited the IL-1beta-induced activation of ERKs and JNKs. Six-
hour pre-incubation with IL-1beta inhibited proliferation of these cells by 40%
at 24 h of incubation, but the inhibition was recovered at 48 h. These findings
suggest that IL-1beta activated ERKs and JNKs in rat gastric epithelial cells and
inhibited cell proliferation, possibly via the specific receptor for IL-1beta.
Activation of MAP kinases by IL-1beta may be mediated by tyrosine kinase and
protein kinase C.
PMID- 10671773
TI - Protective effect of lafutidine against indomethacin-induced intestinal
ulceration in rats: relation to capsaicin-sensitive sensory neurons.
AB - BACKGROUND/AIM: We examined the prophylactic effect of lafutidine, a novel
histamine H(2)-receptor antagonist [(+/-)-2-(furfurylsulfinyl)-N-[4-[4
(piperidinomethyl)-2-pyr idyl]oxy- (Z)-2 butenyl]acetamide], on indomethacin
induced small intestinal ulcers in rats and investigated the relation of this
action to capsaicin-sensitive sensory neurons. METHODS AND RESULTS:
Subcutaneously administered indomethacin (10 mg/kg) provoked ulceration in the
small intestine, mainly the jejunum and ileum, accompanied by increases in
myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities as
well as the enterobacterial numbers invading the mucosa. Intestinal ulcerogenic
response to indomethacin was prevented by 16,16-dimethyl prostaglandin E(2) (10
microg/kg, p.o.) and capsaicin (10 mg/kg, p.o. ) as well as ampicillin (800
mg/kg, p.o.), but not omeprazole (100 mg/kg, p.o.). Likewise, lafutidine (1-10
mg/kg, p.o.), but not cimetidine (100 mg/kg, p.o.), reduced the occurrence of
intestinal ulcers in response to indomethacin in a dose-dependent manner, and a
significant effect was observed at 3 mg/kg or greater. The protective action of
lafutidine as well as capsaicin was almost totally abolished by chemical ablation
of capsaicin-sensitive sensory neurons. Both lafutidine and capsaicin
significantly suppressed the increases in MPO and iNOS activities as well as
enterobacterial numbers in the mucosa. These agents also significantly enhanced
mucus secretion in the small intestine. CONCLUSION: These results suggest that
lafutidine protects the small intestine against ulceration via stimulation of
capsaicin-sensitive sensory neurons. This action may be attributable to
inhibition of enterobacterial invasion in the intestinal mucosa, probably by
increasing the mucus secretion.
PMID- 10671774
TI - Intracellular transport of high-density lipoprotein 3 in intestinal epithelial
cells (Caco-2) is tubulin associated.
AB - BACKGROUND: A retroendocytotic pathway for high-density lipoprotein 3 (HDL(3)) in
cultured intestinal epithelial cell lines has been described. In small intestinal
crypt cells and Caco-2, HDL(3) is internalized, transported to lipid droplets
and, after solubilization of these lipid droplets, resecreted. In the present
study we examined the mechanisms of intracellular transport of HDL(3) in the Caco
2 cell line. METHODS: Apolipoprotein E free HDL(3 )was gold-labeled for
transmission electron microscopy and 1, 1'-dioctadecyl-3,3,3',3'
tetramethylindocarbocyanine iodide [DiI(3)] labeled for fluorescence and confocal
laser scanning microscopy. For tubulin desintegration Caco-2 cells were incubated
with taxol, colchicine and beta- and gamma-lumicolchicine. Tubulin staining was
performed using a FITC labeled antibody. Uptake of HDL(3) was quantified by FACS
analysis. RESULTS: HDL(3) was rapidly internalized and found to be in contact
with lipid droplets in the perinuclear region after 10 min. By transmission
electron microscopy a frequent colocalization of HDL(3)-containing vesicles and
tubular structures was demonstrated. The close association of HDL(3)-containing
vesicles with fluorescence stained tubulin could be confirmed by confocal laser
scanning microscopy. Preincubation of the cells with taxol and colchicine did not
completely prevent internalization but reduced it during a 2-hour incubation
period to less than 50% of the control cells. The transport of DiI(3)-labeled
HDL(3) to the lipid droplets in the perinuclear region was almost completely
blocked by taxol and colchicine. CONCLUSION: Internalization and intracellular
transport of HDL(3) in intestinal epithelial cells (Caco-2) is dependent on a
tubulin-mediated mechanism.
PMID- 10671775
TI - Regulation of PepT1 peptide transporter expression in the rat small intestine
under malnourished conditions.
AB - BACKGROUND AND AIMS: Many investigations suggested that peptide nutrition had a
clinical advantage for nitrogen absorption. Recently, the cDNA encoding the
H(+)/peptide cotransporter PepT1 was cloned. However, the regulatory mechanism of
PepT1 expression under malnourished conditions has not been elucidated. The aim
of this study was to clarify regulatory mechanisms of PepT1 expression. METHODS:
Sprague-Dawley rats were starved for 4 days, semistarved (50% amount of control)
for 10 days, or given total parenteral nutrition (TPN) for 10 days. Rats with
free feeding were used as control. Among those groups, the changes of PepT1 mRNA
level in the jejunal mucosa and PepT1 protein density at the brush-border
membranes were examined by Northern blot and by Western blot analysis,
respectively. RESULTS: Both starvation and TPN treatment caused a significant
decrease in mucosal weight by 41 and 50% respectively. PepT1 mRNA level increased
to 179% in the starved group and also to 161 and 164% in the TPN and semistarved
groups, respectively. In contrast, sodium-dependent glucose transporter 1 mRNA
expression showed no significant change. PepT1 protein density showed similar
changes with the mRNA. CONCLUSIONS: PepT1 gene expression was significantly
enhanced under the malnourished conditions in spite of atrophic changes of
intestinal mucosa.
PMID- 10671776
TI - Tumor necrosis factor-alpha in ileal mast cells in patients with Crohn's disease.
AB - BACKGROUND: Reports that both intestinal and extraintestinal Crohn's disease (CD)
had healed successfully after treatment with anti-tumor necrosis factor-alpha
(TNF-alpha) antibody have strengthened the hypothesis that it has a role in the
treatment of CD. The macrophage is one source of TNF-alpha. Intestinal mast cells
are also thought to have a role in CD, but it is not known if human ileal mast
cells express TNF-alpha. AIM: To find out whether TNF-alpha is expressed by mast
cells in the ileal wall in CD patients and controls. METHODS: TNF-alpha was
sought immunohistochemically in full thickness specimens of ileal wall from
patients with CD (histologically normal, n = 9; inflamed, n = 6) and controls
(patients with colonic cancer, n = 8). Mast cells were identified by
metachromasia and anti-mast cell tryptase immunoreactivity. RESULTS: In all
layers of the ileal wall, and in every specimen investigated, mast cells were the
main cell type that expressed TNF-alpha immunoreactivity out of the TNF-alpha
labelled cells. The number of TNF-alpha- labelled mast cells was greater in the
muscularis propria in patients compared with controls, both in uninflamed (1.7
fold, p < 0.05) and in inflamed bowel (4.6-fold, p < 0.002); greater in the
submucosa in inflamed compared with uninflamed CD (1.6-fold, p < 0. 01), and less
in the lamina propria in inflamed compared with uninflamed CD (0.4-fold, p <
0.05). CONCLUSION: Mast cells are an important source of TNF-alpha in all layers
of the ileal wall, and the increased density of TNF-alpha-positive mast cells in
the submucosa and muscularis propria may contribute to the tissue changes and
symptoms in CD.
PMID- 10671777
TI - Current status of minimally invasive treatment options for localized prostate
carcinoma.
AB - INTRODUCTION: Prostate cancer is the leading malignancy in men today and an
increase in detected localized prostate cancers is expected in the years to come.
Even though radical prostatectomy is an effective treatment, it is associated
with a considerable morbidity in some cases and efforts are made to provide
minimally invasive alternative treatment options with equal efficacy but fewer
side effects. METHODS: Cryosurgical ablation of the prostate (CSAP),
brachytherapy, high-intensity focused ultrasound (HIFU) and radiofrequency
interstitial tumor ablation (RITA) were evaluated after a literature review from
a Medline Search (1966-1998). Furthermore, personal experience and latest data
from the authors were taken into account. RESULTS: All alternative treatments
nowadays make use of sophisticated technology, including the latest ultrasound
devices for exact planning and monitoring of treatment, leading to increased
safety compared to treatments in the 1960s and 1970s. Five-year results of CSAP
show a PSA <1 ng/ml in 60% of cases whereas brachytherapy is able to achieve PSA
<1 ng/ml in 80% of cases in a selected group. Recent outcome data come close to
results of radical prostatectomy series. HIFU and RITA are promising new
technologies that proved to be able to induce extensive necrosis, but the follow
up is too short to determine their definite places in the treatment of prostate
cancer. CONCLUSION: Two alternative treatment options for localized prostate
carcinoma, CSAP and brachytherapy, have been studied with a sufficient number of
patients and an adequate follow-up. The overall results of brachytherapy are
favorable when compared to CSAP and are in the same range as the outcome after
radical prostatectomy. HIFU and RITA are relatively new techniques based on
sophisticated technology that are very promising at present, but a longer follow
up is mandatory.
PMID- 10671778
TI - Intrathecal catheter with subcutaneous port for clonidine test bolus injection. A
new route and type of treatment for detrusor hyperreflexia in spinal cord-injured
patients.
AB - INTRODUCTION AND OBJECTIVES: The objective of this study was to assess the
feasibitity, technical data and use of intrathecal catheter implantation with
subcutaneous port for clonidine test injections and individual evaluation.
METHODS: According to approval of the local ethics committee, 9 consecutive SCI
patients (6 men, 3 women) had catheter and port implantation between January 1998
and May 1999. All did not respond to systemic drug therapy in combination to self
clean intermittent catheterisation (SCIC). Implantation was done under general
anesthesia. Needle and catheter were Medtronic Infusion Synchromed Intraspinal
catheter (Induratrade mark, 8703W). Clonidine test injections were allowed at D5.
RESULTS: There were no complications during operation. Follow-up was 8.2 months
(0.5-17). After clonidine bolus injection test and validation, 6 patients decided
to have permanent pump implantation, 2 chose other therapies and one did not
tolerate clonidine intrathecal injections for blood arterial pressure side
effects. CONCLUSIONS: Intrathecal clonidine may represent a useful conservative
treatment of both severe bladder hyperreflexia and spinal spasticity. Its short
term effects can be individually evaluated through bolus injection in
subcutaneous port before definitive pump implantation.
PMID- 10671779
TI - Natural history of residual renal stone fragments after ESWL.
AB - OBJECTIVE: After extracorporeal shock wave lithotripsy (ESWL), residual fragments
(RF) 4 mm or less are usually considered as clinically insignificant. We
retrospectively reviewed the natural history and clinical significance of 97
noninfected and isolated RF (4 mm or less) observed 3 months after the last ESWL
session on renal tomography. PATIENTS AND METHODS: They represented 83 among 1,
216 patients treated by ESWL over a 9-year period (1989-1997). These RF were
mostly localized in the inferior calyx (62%). Median follow-up was 40.6 months
(range: 7-96 months). Renal tomography was always performed at the end of follow
up. RESULTS: Stone-free status, or a decreased, stable or increased amount of
residual stone occurred in 27 (33%), 1 (1%), 24 (29%) and 31 (37%) of the 83
patients, respectively. During this study, 18 patients (22%) were proposed for a
complementary treatment related to a size increase of the residual fragments (13
ESWL, 1 retrograde endoscopy, 3 percutaneous nephrolithotomy, and 1 polar
inferior nephrectomy). CONCLUSION: The term clinically insignificant should not
be employed to describe RF after ESWL. Efforts should be performed to obtain true
stone-free status after ESWL.
PMID- 10671780
TI - Increase in the prevalence of symptomatic upper urinary tract stones during the
last ten years.
AB - PURPOSE: In industrialized countries the prevalence of upper urinary tract stones
has continually increased during the 20th century, but there are considerable
differences between countries and also within the same country. To study whether
there is still an increase in the frequency of renal stones, an investigation was
undertaken to determine the prevalence of stone formers in a village near Milan,
Italy, during two time periods, with an interval of 12 years. MATERIALS AND
METHODS: Questionnaires were administered in 1986 and 1998 to all adult (age >25
years) occupants of two random samples of households in the village. Participants
were asked whether they had experienced a kidney stone during their lifetime.
RESULTS: The overall prevalence of stone formers among males was 6.8% in 1986 and
10.1% in 1998; that among females was 4.9% in 1986 and 5.8% in 1998. In all age
classes, the respondents in the 1998 survey more frequently reported a history of
stones than in 1986, but the prevalence of renal stones was significantly higher
in 1998 than in 1986 only among males aged 31-40 and 51-60 years. The yearly
incidence was estimated at 0.4%, with 0.6 and 0.18% in men and women,
respectively. CONCLUSIONS: This marked increase in renal stones could be the
result of environmental factors such as dietary habits and lifestyle, in
particular the influence of an increased consumption of animal protein should be
considered.
PMID- 10671781
TI - Extracorporeal shockwave lithotripsy for ureterolithiasis in patients with
urinary bilharziasis: efficacy and variables that influence treatment outcome.
AB - OBJECTIVES: Schistosomiasis affecting the ureter is commonly accompanied by
ureteric dilatation with or without ureteric stricture and altered ureteric wall
motility that can influence extracorporeal shockwave lithotripsy (ESWL) results.
This study attempts to identify variables that may influence the outcome of ESWL
in the treatment of ureterolithiasis in patients with urinary bilharziasis.
PATIENTS AND METHODS: Forty-three patients with urinary schistosomiasis and
ureterolithiasis treated with ESWL were reviewed. The study data include
characteristics of patients, stones, urinary tract treated and details of ESWL
treatment. RESULTS: Thirty-five patients (81.3%) were stone-free at 3 months.
Multivariate analysis with logistic regression identified two significant
variables that influenced treatment outcome, namely the presence of ureteric
stricture (p = 0.004) and the ESWL voltage (p = 0.003). Ten ureteric strictures
were encountered in 9 patients (21%), the majority of these were diagnosed post
ESWL when patients failed to pass well-fragmented stones in spite of pre-ESWL
evaluation. CONCLUSIONS: In situ ESWL is a safe and effective first line of
treatment for urinary stones in bilharzial ureters. The presence of concomitant
bilharzial stricture is a significant variable which affects the treatment
outcome. Every effort should be made to rule out and deal with possible
complicating factors such as ureteric strictures in the pretreatment period.
PMID- 10671782
TI - Prevalence and risk factors for urinary incontinence in Italy.
AB - OBJECTIVES: To analyze the frequency and risk factors for urinary incontinence
(UI) in Italy. METHODS: Eligible for this cross-sectional study were men aged
>/=50 years and women aged >/=40, randomly identified among registered subjects
of a network of general practitioners during the period March-October 1997. All
subjects were invited by telephonic interview to determine the presence of UI,
reported by the subjects as loss of urine in the last year. The subjects with UI
were further questioned at home for evaluation of the type, degree and frequency
of UI episodes. RESULTS: Of the 5,488 subjects interviewed (2,767 women and 2,721
men), 92 (3%) men and 316 (11%) women reported at least one episode of UI during
the year before the interview. The frequence of UI increased with age both in men
and women, being 2 and 11% in men and women, respectively, aged 50-60 years and 7
and 16% in those aged >/=70. Of the subjects with UI identified, 229 women and 64
men and a group of 289 subjects without UI were questionned at home using a
detailed questionnaire. Six and 55% of men and women, respectively, reported
stress incontinence, 20 and 12% urge incontinence and 20 and 24% mixed
incontinence. The risk of UI increased with body mass index in women. A history
of recurrent urinary infection was associated with UI in men and less markedly in
women. No association emerged between education, smoking and alcohol or coffee
consumption and risk of UI. Parity was directly associated with the risk of UI in
women. CONCLUSIONS: The study offers a quantitative estimate of the prevalence of
UI and its main risk factors in this Italian population.
PMID- 10671783
TI - A comparison of health care financing policies for incontinence products in
European countries.
AB - OBJECTIVES: This paper offers an overview of the different health care financing
policies for incontinence products in 16 European countries and provides health
care decision-makers with a framework for positioning their financing policy for
incontinence products versus other European countries. METHODS: A questionnaire
was sent to institutions or persons acquainted with the health care financing
system towards incontinence products in 19 countries. Further details were
collected by additional telephone interviews and information from several
informants. Three countries did not provide information. RESULTS: Financing
systems for incontinence products differ widely from country to country. In all
countries, hospitalized incontinent patients are better covered than patients
residing in institutions for geriatric care. It is furthermore a common
phenomenon that patients living at home receive even less coverage. Moreover,
most countries apply a fairly uniform type of financing system, meaning that,
once assessed in need, financial coverage is very similar for all patients (i.e.
not very much differentiated with respect to the nature and severity of their
incontinence problems). CONCLUSION: Given the serious potential impact of
incontinence on citizens' quality of life and given the substantial variations in
degree of incontinence, most countries could improve their utilization of
(scarce) health care resources devoted to incontinence by developing more
'selective' payment policies, whereby reimbursement is 'tailored' to patients'
needs.
PMID- 10671784
TI - Frequency and determinants of erectile dysfunction in Italy.
AB - OBJECTIVE: To analyze the prevalence and risk factors for erectile dysfunction
(ED) in Italy in a cross-sectional study. METHODS: Eligible for the study were
men aged 18 years or more, randomly identified by 143 general practitioners among
their registered patients during the period January 1996 to February 1997. ED was
defined as the impossibility to achieve and maintain an erection sufficient for
satisfactory sexual performance. RESULTS: Of the 2, 010 men interviewed, 257
(12.8%) reported ED. The prevalence increased with age, from 2% in men aged 18-39
to 48% in those >70 years (tested for trend, p = 0.0001). A history of
cardiopathy, diabetes, hypertension, neuropathy, thrombotic/hemorrhagic stroke,
peripheral vascular disorders, pelvic/medullary injury and pelvic
surgery/radiation all increased the risk of ED. The association of hypertension
and diabetes tends to increase the risk of ED. In comparison with nondiabetic and
nonhypertensive men, the odds ratio (OR) was 1.4 (95% confidence interval (CI),
0.7-3.2) for hypertensive men without diabetes, 4.6 (95% CI, 1.6-13.7) for
diabetic men without hypertension and 8.1 (95% CI, 1.2-55.0) for men with
diabetes and hypertension. In comparison with never smokers, the OR of ED was 1.7
(95% CI, 1.2-2.4) for current smokers and 1.6 (95% CI, 1.1-2.3) for ex-smokers
and increased with duration of the habit. CONCLUSIONS: The study offers a
quantitative estimate of the prevalence of ED and of its main risk factors in
Italian men.
PMID- 10671785
TI - AMS three-piece inflatable implants for erectile dysfunction: a long-term multi
institutional study in 200 consecutive patients.
AB - OBJECTIVES: The aim of this study was to assess the longterm mechanical
reliability of AMS (American Medical Systems) three-piece inflatable implants and
their impact on patient-partner satisfaction in 200 consecutive patients with
erectile dysfunction who underwent surgery in five different institutions.
METHODS: Patient charts included in the study were collected and extensively
assessed to record pre- and intraoperative data and postoperative complications.
All patients and 120 partners were then seen often in the office at a mean follow
up of 59 months (range 6-130) and they were extensively questioned about function
of the device and its impact on the couple's sexual life. RESULTS: At the long
term follow-up, 185 patients (92.5%) were still engaging in sexual intercourse
with a mean frequency of 1.7/week. Patients and partners reported prosthetic
erections as excellent, satisfactory or poor in 96 (48%), 100 (50%) and 4 (2%)
cases, and in 20 (17%), 80 (66%) and 20 (17%) cases, respectively. Postoperative
sexual activity was considered excellent, satisfactory or poor by 140 (70%), 44
(22%) and 16 (8%) patients and by 34 (28%), 81 (68%) and 5 (4%) partners,
respectively. Reasons for patients' complaints included postoperative penile
shortening in 60 (30%) cases and poor glandular engorgement in 40 (20%) cases.
Partners' main complaint was unnaturalness of the prosthetic erection, a factor
reported by 30 (25%) subjects. Complications requiring surgical exploration
included infection in 12 patients (6%) and mechanical failure in 8 patients (4%).
Kaplan-Meier estimates demonstrated significantly decreased mechanical survival
for the Ultrex type of cylinders compared to the CX type of cylinders.
CONCLUSIONS: AMS three-piece inflatable implants provide an overall patient and
partner satisfaction rate of 92 and 96%, respectively. However, postoperative
penile shortening and poor glandular engorgement were the causes of some
complaints among the patient population as well as the unnaturalness of
prosthetic erection among female partners. In the long-term, mechanically
speaking, CX cylinders seem to be more reliable than the Ultrex ones.
PMID- 10671786
TI - Glide wires for delayed catheterization of severely obstructed ureters.
AB - OBJECTIVE: Failure to retrogradely catheterize an obstructed ureter may require a
nephrostomy. We describe an endoscopic technique to catheterize a severely
obstructed ureter when the obstruction does not permit passage of a ureteral
catheter over a wire. METHODS: Using a cystoscope, a wire is passed beyond the
obstruction. When the attempt to insert a ureteral catheter over the wire fails,
the wire is left in place, fixed externally to a Foley catheter. A second attempt
to insert a ureteral catheter is carried out 24-48 h later. RESULTS: The
procedure was performed in 5 patients. Ureteral catheterization, which was
initially impossible, was performed successfully and without complications.
CONCLUSIONS: Maintaining a wire in place over a short period of time facilitates
a subsequent ureteral catheterization.
PMID- 10671787
TI - Nephrectomy - indications, complications and postoperative mortality in 646
consecutive patients.
AB - OBJECTIVE: To gain information about the indications for and complications of
conventional nephrectomy, also to create standards for future evaluation of
nephrectomies performed by minimal invasive techniques. METHODS: We present a
historical 20 years' series of 646 consecutive nephrectomies performed in the
period of 1978-1997. Malignant disease led to the operation in 437 cases, of
which 98 were urothelial tumors in the renal pelvis or ureter. 209 kidneys were
removed due to benign conditions. The incidence of nephrectomy for benign
conditions has declined from 75 in the first 5-year period to 32 in the last.
RESULTS AND DISCUSSION: Postoperative complications occurred in 100 patients
(15.5%). Nephrectomy for malignant disease had a significantly higher rate of
complications than operations for benign conditions (p<0.001), especially
hemorrhagic complications and pneumonias were more frequent. There were no
differences as a result of the operative approach. Reoperation was carried out in
3.0% of the cases. Overall mortality rate (<30 days) was 3.1%.
PMID- 10671788
TI - Comparative study of two different TRUS-guided sextant biopsy techniques in
detecting prostate cancer in one biopsy session.
AB - OBJECTIVE: The aim of this study was to compare a transrectal ultrasound (TRUS)
guided sextant biopsy technique, which puts more emphasis on the apical region of
the prostate where most prostate carcinomas (PCs) develop, with the standard
sextant biopsy technique. METHODS: A total of 280 patients with suspected PC were
included in this analysis. Twelve biopsy cores were obtained from all patients.
Six biopsy cores were taken within a lateral parasagittal plane from each lobe at
the apex, middle and basis, with an angle of approximately 45 degrees (technique
A), and 6 further biopsy cores were taken from the left to the right lateral
margin always penetrating the prostate in the apex with the same angle (socalled
fan-shaped technique, technique B). Technique A predominantly samples in the
sagittal and technique B samples more in the transversal plane with emphasis on
the apical region where most PCs develop. The sensitivity in detecting PCs for
both techniques was calculated and correlated to the serum prostate-specific
antigen (PSA) levels. RESULTS: A total of 72 PCs (25.7%) were diagnosed. We
subsequently performed subgroup analysis depending on the serum PSA levels: in
patients with a PSA of =10 ng/ml (n = 27) technique A has a PC sensitivity of
88.8% (p = 0.037) and technique B 96.2% (p = 0.326) as compared to our reference
standard of 100% by sampling 12 biopsy cores in the same prostate. The number of
positive biopsy cores using technique B was superior in 12 cases as compared to 3
cases with technique A (p = 0.04). In 12 patients the number of positive biopsy
cores was identically. In patients with a PSA of >10 ng/ml (n = 45) technique A
has a PC sensitivity of 93.3% (p = 0.083) and technique B 88.8% (p = 0.023) as
compared to our reference standard. The number of positive core biopsies using
technique A was superior in 14 cases as compared to 12 with technique B (p =
0.154). In 19 patients the number of positive biopsies was identical. CONCLUSION:
Our data suggest that in patients with PSA of =10 ng/ml technique B bring
significant benefit with regard to the number of positive core biopsies, as well
as an enhanced PC detection rate which is near the 12-core biopsy. Due to the
fact that technique B samples more in the apical region where most cancers
develop, it should be performed in suspected early stage cancers of the prostate
(PSA=10 ng/ml).
PMID- 10671789
TI - A study of pelvic floor function pre- and postradical prostatectomy using
clinical neurourological investigations, urodynamics and electromyography.
AB - OBJECTIVES: Incontinence after radical prostatectomy is addressed to sphincter
damage and/or bladder dysfunction. Taking into account a high cure rate of
incontinence by pelvic floor biofeedback treatment, the search for further
mechanisms of a complex physiological concept seems feasible. METHODS: To
characterize pelvic floor function, 18 patients were prospectively evaluated
before and after radical prostatectomy by clinical neurourological tests,
urodynamics and needle/surface electromyography (EMG). RESULTS: In all patients
(mean age 62 years) investigations were completed successfully. The outcomes of
neurourological investigations (sacral reflexes, voluntary pelvic floor
contraction and relaxation) and needle EMG showed no significant changes in the
pre-/postoperative comparison. Only by using surface EMG polygraphy change of
activation patterns during pelvic floor contraction (decreased mean and medium
frequency) could be found. CONCLUSION: In patients without preexisting bladder
dysfunction and with a basically normal operative and postoperative course, fine
motoric changes of pelvic floor function are the main finding. This cannot be
explained by a pure anatomical approach. Neurophysiological events, like a
barrage of nociceptive information, caused by surgical dissection and an
inflammatory reaction due to the healing process, contribute to altered
processing within the central nervous system. The appreciation of these
mechanisms, well studied in neuroscience and pain research, offers a better
understanding of surgery-related short- and longterm morbidity after pelvic
surgery, i.e., urinary incontinence and erectile dysfunction.
PMID- 10671790
TI - Serum anti-p53 antibodies and p53 protein status in the sera and tumors from
bladder cancer patients.
AB - OBJECTIVES: The purpose of this study was to evaluate the association between the
serum anti-p53 antibodies (Abs) status and the p53 protein status in the sera and
tumors as well as clinical or pathological parameters in bladder cancer patients
retrospectively. METHODS: Serum samples from 100 patients with bladder cancer
were assayed for anti-p53 Abs and p53 protein by enzyme-linked immunosorbent
assay (ELISA). A monoclonal antibody DO7 was used for immunohistochemical
staining of tumor p53 protein. RESULTS: Prevalences of serum anti-p53 Abs, serum
p53 protein and tumor p53 protein were 12, 1 and 63%, respectively. There was a
significant correlation between serum anti-p53 Abs status and factors including
tumor stage, tumor grade, and tumor p53 protein status. In the univariate
analysis, tumor stage, tumor grade, serum anti-p53 Abs status, and tumor p53
protein status were significantly associated with an increased risk of death.
Multivariate analysis showed that tumor stage was the only independent prognostic
factor among the factors examined. CONCLUSIONS: The present study suggests that
serum anti-p53 Abs had a limited value as a tumor marker in bladder cancer
patients. Further studies to elucidate the mechanism of anti-p53 Abs production
will be necessary for a better understanding of the immune status in bladder
cancer patients.
PMID- 10671791
TI - Pure squamous cell carcinoma of the bladder in western countries. Report on 19
consecutive cases.
AB - INTRODUCTION: Pure squamous carcinoma (SCC) is a rare entity in western regions.
The management of SCC still remains similar to that of transitional carcinoma,
although it is a different entity. A retrospective review can be helpful in
understanding the biological behavior of this uncommon vesical tumour. MATERIAL
AND METHODS: Nineteen consecutive cases of pure SCC of the bladder, not related
to bilharziasis or spinal cord injury, are herein reported. Fifteen patients were
submitted to radical cystectomy, combined with emasculation in 1 case and
unilateral nephroureterectomy in another. Partial cystectomy was performed in 1
patient and transurethral resection followed by radiotherapy in 3 more cases.
Involvement of prostatic urethra and upper urinary tract was evident in 9 (47.3%)
and 5 patients (26.3%), respectively. Four patients were submitted to neoadjuvant
chemotherapy and 1 to presurgical radiotherapy without any objective response.
Adjuvant chemotherapy was performed in 3 patients. At a mean follow-up of 52
months, 6 patients (31.5%) are alive without any evidence of disease. SCC antigen
was monitored in 5 patients. The possible role of this marker in bladder SCC is
discussed. CONCLUSIONS: Invasion of the upper urinary tract and prostatic urethra
seems more common in SCC than in transitional cell carcinoma. Distant metastases
are rare. Most patients die after attempts of locoregional control of the tumor
have failed. Extensive surgery is recommended. Preoperative radiotherapy should
be considered since pelvic recurrences are the leading cause of progression in
squamous cell carcinoma.
PMID- 10671792
TI - Transitional cell carcinoma in dialysis patients.
AB - OBJECTIVE: The aim of our study was to determine whether there is an increased
incidence of urothelial cancer, especially transitional cell carcinoma (TCC), in
uremic patients on dialysis. METHODS: Retrospective chart analyses were completed
for 1,910 uremic patients undergoing maintenance dialysis between January 1987
and December 1997. The incidence of urinary tract cancer was assessed. Only the
patients with cancers diagnosed after start of dialysis were enrolled in the
study. RESULTS: Of the 1,910 patients, 70 had concomitant urinary tract cancers.
Nineteen patients (0.99%), including 17 patients with TCC and 2 patients with
renal cell carcinoma, were diagnosed after the initiation of dialysis. The
average duration from dialysis to TCC diagnosis was 38.3 (range 2-144) months.
Painless gross hematuria was the cardinal symptom in 16 of the 17 patients with
TCC. In the 17 patients with TCC, no distant metastases were found at the time of
diagnosis. Fourteen patients (82.3%) were stage 0 or A, and 1 patient was stage
B1. CONCLUSIONS: The 0.89% incidence of TCC in our dialysis patients was high as
compared with that of the general population. The risks of developing urinary TCC
in dialysis patients were examined, and we suggest that immunosuppressive stage,
dialysis procedure, and chronic bladder irritation (decreased urinary wash
effect) may play a part in the development of urinary TCC in dialysis patients.
Early detection of hematuria due to regular visits and decreased exposure of
urinary tract epithelium to carcinogens from urine may explain why early-stage
TCC was seen in most of our patients.
PMID- 10671793
TI - Sexual and social life of men operated in childhood for hypospadias and phimosis.
A comparative study.
AB - OBJECTIVE: Hypospadiacs have been reported to be sexually less active, make their
sexual debut later, have more negative genital appraisal and have less qualified
professions than other men. We studied whether the reported differences are due
to circumcised-like penile appearance. METHODS: We compared the social and sexual
life of hypospadias patients to circumcised patients. A detailed questionnaire
was mailed to 64 patients operated for hypospadias and to 64 age-matched patients
circumcised for phimosis 18-31 years ago. RESULTS: Fortysix (75.0%) hypospadiacs
and 43 controls (67.2%) returned the questionnaire. Sexual life and success in
life in general among hypospadiacs did not differ from those of circumcised
patients. Hypospadiacs were markedly more dissatisfied with the result of the
operation (33 vs. 5%). Ten hypospadiacs and one control were dissatisfied with
the appearance of their penis (p<0. 01). Thirty-seven hypospadiacs (80.4%) had
voiding problems compared to 20 controls (46.5%) (p<0.01). CONCLUSIONS: Our
results demonstrate that even patients with a less than perfect technical result
are able to live a satisfactory sexual life and to succeed in life in general.
Minor differences observed in sexual life between men operated for hypospadias
and other men seem not to be due to the circumcised appearance of the penis even
in cultures where circumcision is uncommon.
PMID- 10671794
TI - Tubularized incised plate urethroplasty for distal and mid-penile hypospadias.
AB - Tubularized incised plate urethroplasty was performed to repair 20 distal and 5
mid-penile hypospadias cases. In distal hypospadias repair meatal stenosis
occurred in 1 patient and urethral fistula in another. The overall complication
rate in this group was thus 10%. Among midpenile hypospadias cases meatal
stenosis was observed in 1 (20%) patient. As a conclusion, tubularized incised
plate urethroplasty was found to be a successful method for treating distal
hypospadias and encouraging results were obtained in mid-penile hypospadias
cases.
PMID- 10671795
TI - Pediatric urolithiasis in sub-saharan Africa: a comparative study in two regions
of Cameroon.
AB - OBJECTIVE: To determine the composition of caculi and the predisposing factors
for stone nucleation and growth in children from two regions of Cameroon.
METHODS: This was a cross-sectional study involving 21 children, 17 from the
northern and 4 from the southern region, over a 6-year period. Data on age, diet,
residence, clinical presentation, location of stone, and results of stone
analysis were collated following a preestablished proforma. A computerized
analysis of the data was carried out. The constituents of stone sections and
nidus were assembled so as to determine the principal causes of stone nucleation
and growth. RESULTS: Pediatric urolithiasis was more common in the northern
Sahelian belt of Cameroon. Males and rural dwellers were more commonly affected.
Endemic (bladder) stone disease was found in the majority of the patients. All
stones were mixed. The most frequent constituents of the stones were ammonium
urate, struvites, and whewellite in descending order of percentage mean volume
per stone. The nidus was available for study in only 10 stones, and its
composition revealed heterogeneity of causes of nucleation. The commonest cause
for stone formation and growth were infection and hyperuricosuria (malnutrition).
CONCLUSIONS: Pediatric bladder stone disease is not uncommon in northern
Cameroon. Many factors combined to predispose to stone nucleation and growth, but
the level of socioeconomic development was preponderant. Stone composition
indicated that urolithiasis in children was a heterogeneous disorder, but
hyperuricosuria, insufficient diuresis, and infection associated with
malnutrition seemed to be the most common causes.
PMID- 10671796
TI - Endoscopic urethroplasty with a free graft on a biodegradable polyglycolic acid
spiral stent. A new technique.
AB - OBJECTIVES: Explore the possibility of an endoscopic urethroplasty with a free
graft on a biodegradable, self-reinforced polyglycolic acid spiral stent.
METHODS: Urethral strictures, failures of previous urethrotomies, which still can
be incised endoscopically are selected. Strong fibrotic strictures which are bad
indications for the use of a free graft are excluded. A free graft (skin on
mucosa) is sutured around the stent and brought at the place of the
endoscopically opened stricture where the graft is fixed with a suture through
skin, bulbar muscles and spongiosum. A suprapubic diversion is left for 10 days.
The stent keeps the graft in contact with surrounding well vascularized tissue
where it can take. Other parts of the graft become necrotic. The stent hydrolyses
in about 3 weeks. MATERIAL AND RESULTS: 10 patients with bulbar strictures from 2
to 4 cm in length and failed previous urethrotomies were treated successfully
with this technique. The follow-up varies from 39 to 3 months (mean: 21 months).
After 2 years 1 stricture recurred in a man who underwent regular endoscopies for
recurrent bladder tumors. All other patients were successful until now. One stent
got lost in the bladder during the procedure but could be brought at the right
place. Other complications were 1 hematuria, 1 urosepsis, 1 perineal pain, 1
painful evacuation of a part of the stent 16 days after operation, and 1
difficult micturition. CONCLUSION: The preliminary experiences indicate that this
technique is a possible treatment of short bulbar strictures after failure of
endoscopic treatment.
PMID- 10671797
TI - Clinical and therapeutical guidelines for chronic prostatitis. from
bacteriological importance to neuromuscular considerations.
PMID- 10671798
TI - Evaluation of nucleolar organizer regions in human bladder cancers.
PMID- 10671799
TI - Immediate and delayed management of renal trauma
PMID- 10671800
TI - Ups and downs of aging studies in vitro: the crooked path of science.
AB - Different approaches using cell culture techniques to study the biology of aging
are critically described. Most of the studies concerned the relationship between
cell division potential and aging. The growth potential of cells is fundamental
for aging of the organism, since it relates to phenomena such as the regeneration
of tissues, wound healing, the immune response, and stem cell renewal.
Unfortunately many experiments were misinterpreted disregarding the physiology of
the mammalian organism. The terminal postmitotic cell, on which most research has
been concentrated, seems irrelevant for aging of the organism. Nevertheless, some
experiments yielded important contributions to the understanding of the biology
of cell division. Future research should ascertain such interesting suggestions
as the terminal differentiation hypothesis of the human fibroblast life cycle. It
is important to elucidate the significance of the increased number of postmitotic
cells in pathological processes. A neglected area should be further explored: the
relationships between structural modifications of the cell, decreased probability
of activating energy barriers, and decline of the division potential.
PMID- 10671801
TI - Plasma leptin concentrations in relation to sick euthyroid syndrome in elderly
patients with nonthyroidal illnesses.
AB - BACKGROUND: Leptin, the ob gene product, seems to be involved in regulating
energy expenditure in humans, but its role in the pathophysiology of the energy
imbalance in chronically ill patients is largely unknown. OBJECTIVE: To evaluate
plasma leptin concentrations and thyroid function in elderly patients with
nonthyroidal illnesses (NTI). METHODS: Sixty-four NTI elderly patients (75.0 +/-
6.3 years, 27 males and 37 females) and 21 age- and sex-matched healthy controls
(73.0 +/- 5.5 years, 9 males and 12 females) were enrolled in the study. In all
subjects tri-iodothyronine (T(3)), thyroxine (T(4)), reverse T(3) (rT(3)), free
T(3) (fT(3)), free T(4) (fT(4)), TSH, and plasma leptin concentrations were
measured. Nutritional status was also evaluated in all subjects studied by the
measurement of body mass index (BMI), lymphocytes, serum iron, hemoglobin, plasma
albumin, transferrin and total cholesterol. RESULTS: The data on thyroid hormones
enabled us to identify three groups: group A, subjects (15 patients) with T(3)
and fT(3) levels comparable to those of controls; group B, subjects (25 patients)
with T(3) and fT(3) levels lower than controls and rT(3) levels comparable to
those of controls; group C, subjects (24 patients) with T(3) and fT(3) levels
lower than those of controls and high rT(3) levels. The patients of group C
showed lower plasma leptin levels than the controls, 6.6 (5.5-14.2) and 16.3 (7.2
23.7) ng/ml (median with interquartile range in parentheses, p < 0.05),
respectively. Females also showed higher plasma leptin levels than males in the
controls, group A and group B, but not in group C. Moreover, plasma leptin
concentrations were directly correlated to BMI in all the groups studied, while a
negative correlation between leptin and rT(3) was detectable in group C (r =
0.44, p < 0.05), also after adjusting for BMI and sex. CONCLUSIONS: The
concurrence of modifications in plasma leptin and thyroid hormones concentrations
found in elderly NTI patients with a sick euthyroid syndrome could reflect a
particular neuroendocrine status, leading to a reduction in the catabolic
processes in the course of chronic diseases.
PMID- 10671802
TI - Relationship between left ventricular geometry and brain natriuretic peptide
levels in elderly subjects.
AB - BACKGROUND: The plasma brain natriuretic peptide (BNP) level in elderly patients
is elevated, but the mechanism of this increase is not clear. OBJECTIVE: To
examine the relationship between left ventricular geometry and BNP levels in
elderly subjects. METHODS: We investigated the effects of left ventricular (LV)
geometry on plasma BNP levels by measuring these levels in elderly patients with
or without LV hypertrophy. Patients were classified into 4 groups based on
echocardiographic data: normal geometry; concentric remodeling; eccentric
hypertrophy (EH), and concentric hypertrophy (CH). The samples were analyzed for
BNP and endothelin-1 (ET-1). RESULTS: Among the 4 groups, there were no
differences in plasma ET-1 levels, ejection fraction, percent fractional
shortening, or indices of diastolic function. Plasma BNP levels in EH and CH were
higher than those in the normal geometry and concentric remodeling groups. There
was a good correlation between plasma BNP levels and the relative wall thickness
in EH, and between plasma BNP levels and the posterior wall thickness in CH (r =
0.474, r = 0.396, respectively, both p < 0.05). There were also good correlations
between plasma BNP levels and LV mass index (LVMI). A stepwise multiple
regression analysis showed that age and LVMI were significant independent
contributors to plasma BNP levels. CONCLUSIONS: These results suggest that aging,
increased wall stress and the extent of cardiac hypertrophy contribute to
elevated BNP levels in the elderly.
PMID- 10671803
TI - Barium enema in frail elderly patients.
AB - BACKGROUND: Barium enema (BE) examinations for the investigation of suspected
colonic disease are often unsuccessful in elderly patients. OBJECTIVE: The
purpose of this study was to evaluate the success rate of BE in hospitalized
frail elderly patients. METHODS: Four hundred and seventy-two elderly patients
hospitalized for different reasons underwent BE examinations. The medical charts
and radiological reports were retrospectively reviewed. RESULTS: One hundred and
ninety-two (41%) BE examinations were considered inadequate; mostly (32%) because
of inappropriate preparation. Sixty-seven patients (14%) were not cooperative and
could not retain the contrast material, and in 25 patients (5%), the examination
failed due to both these reasons. The characteristics associated with
unsuccessful BE examination were the mean number of medical problems (p < 0.001),
the mean number of scheduled medications (p < 0.05) and in particular the long
term use of laxatives (p < 0.01) or antiparkinsonian drugs (p < 0.01). Of great
significance in predicting an inadequate BE were the patient's functional status
(p < 0.001) and the presence of dementia (p < 0.001). CONCLUSIONS: The high
percentage of unsuccessful BEs in the frail elderly suggests that clinicians
should carefully consider the need for that examination in these patients. We
suggest that only in patients where there is a clear suspicion of a bleeding or
obstructing tumor should a BE examination be performed, and even in these cases,
colonoscopy or CT may be preferable as the initial examination in the frail
elderly.
PMID- 10671804
TI - A randomized controlled trial of fall prevention strategies in old peoples'
homes.
AB - BACKGROUND: Falls are a major cause of morbidity in old age. A small number of
fall prevention trials in cognitively intact community-dwelling older people have
been effective. This study set out to examine the preventability of falls in
older people living in institutional care. OBJECTIVE: To evaluate the
effectiveness of falls risk factor assessment/modification and seated balance
exercise training in reducing falls among elderly people living in residential
care. METHODS: 133 residents with a mean age of 84+/- (SD) 6.8 years were
allocated at random by home to receive either a 6-month falls risk factor
assessment/modification and seated balance exercise training programme (n = 77)
or 6 months of reminiscence therapy (n = 56). The risk factors targeted were
postural hypotension, polypharmacy, visual acuity, and ambient lighting levels.
Falls risk factor assessments and recommendation for modifications were performed
at baseline in the intervention group and assessments repeated at 6 months.
Functional reach, reaction time, timed up-and- go, grip strength, spinal
flexibility, and Philadelphia Geriatric Centre Morale Scale and Mini-Mental State
Examination scores were determined at baseline and at 6 months by a 'blind'
observer. Falls and fractures were then monitored in both groups during a 7- to
12-month falls-monitoring follow-up period. RESULTS: Only 90 of 133 (67.7%)
residents completed the 6-month intervention period, and 84 (63.2%) completed the
7- to 12-month falls-monitoring follow-up period. Both prevalence of postural
hypotension (p = 0.0005) and poor visual acuity (p = 0.04) were reduced in the
intervention group. There was no difference between the groups in the number of
falls sustained, the risk of falling [odds ratio 0.45 (95% CI 0.19-1.14)], or in
the risk of recurrent falling [odds ratio 1.07 (95% CI 0.40-2.97)]. No
significant differences were found between the groups with regard to change in
other outcome measures. CONCLUSIONS: The high drop-out rate reduced the power of
this study to detect any effect of the interventions used. It is possible that
either the exercises were not sufficiently vigorous or that to improve balance
exercises must be performed standing. Further research is required to identify
effective fall prevention strategies for elderly people in residential settings.
PMID- 10671805
TI - A critical point for the onset of falls in the elderly. A pilot study.
AB - BACKGROUND: Falls in the elderly during walking often result in very serious
injuries. Gait analysts have meticulously explored the causes of these falls and
reported age-related changes in gait parameters. It has not been possible to
determine the level of derangement of gait parameters that is critical for falls
in this population. There is the need to identify age-related interaction
patterns of gait parameters. Such an interaction pattern could at least provide a
mirror image of how the neural system adjusts to the age-related derangement.
OBJECTIVE: The purpose of this study was to utilize the interaction of gait
parameters in the velocity field diagram (VFD) to explore the causes of falls in
the elderly during walking. The VFD is a graph of the numerical values of gait
parameters versus speed numbers derived by serially numbering the five speeds of
walking from very slow to very fast. METHODS: The gaits of healthy elderly
persons (fallers and nonfallers) were recorded with those of healthy younger
controls. The subjects walked along a 5-meter walkway in their shoes, but without
walking aids. The subject walked from very slow to very fast according to what
he/she considered to represent the respective speeds. Strides were counted, and
the time taken to walk the distance was noted with a stopwatch. Numerical values
of velocity (m/s), stride length (m), and stride frequency (strides/s) were used
to construct the VFD. RESULTS: The x-axis value of the equality point (E(1)) of
the numerical values of velocity and stride frequency of the three study groups
differed significantly (Anova alpha = 0.05, F = 22.94, p = 0. 001). The E(1) was
formed in relation to gait efficiency. The x-axis value of the E(1) was least in
controls and greatest in fallers, while the reverse was the case for gait
efficiency. The E(1) of nonfallers defined a critical point for the precipitation
of falls in the elderly. The value on the x-axis of the VFD of the critical point
for the precipitation of a fall was 3.5 velots. A vertical line passing through
E(1) and abutting on the x-axis at 3.5 velots was described as fall precipitation
line. CONCLUSION: Since the x-axis value of the critical point for the
precipitation of a fall was 3.5 velots, it was suggested that elderly persons who
equalize the numerical values of velocity and stride frequency at 3.5 velots
should be provided with adequate preventive measures against falls.
PMID- 10671806
TI - Pancreas and aging: a study using ultrasonography.
AB - BACKGROUND: The pancreas undergoes a continuous aging process leading to
alterations such as atrophy, fatty infiltration and fibrosis. OBJECTIVE: The aim
of this study was to determine the normal ultrasonic aspect of the pancreas and
any relationship to age with special regard to pancreatic echogenicity and
pancreatic duct diameter. METHODS: In the study on pancreatic echogenicity 131
patients (56 male, 75 female), aged 18-92 (median 52) years, with normal weight
were examined prospectively. The echogenicity of the pancreas was compared with
the normal liver and divided into four different categories. The prospective
investigation into any age relationship of pancreatic duct diameter was performed
on 101 patients (44 male, 57 female), ages 18-91 (median 53) years, with normal
weight. In both studies, the patients were split into seven age groups. For
statistical analysis the chi-square test for independence was used. RESULTS: With
advancing age, ultrasonography demonstrated an increasing echogenicity of the
pancreas, beginning in the 4th decade of life. Most patients over 50 years, and
all patients over 80 had a marked echogenicity, distinctly higher than that found
in the liver. The mean pancreatic duct diameter of all patients in the second
study was 1.9 mm. Younger subjects had a smaller diameter - average 1.5 mm in the
group 18-29 years - but with advancing age a distinct duct enlargement was
observed: mean 1. 9 mm in the group 40-49 years, mean 2.3 mm in patients over 80
years, but not exceeding 3 mm. CONCLUSION: On ultrasonography, the aging process
of the pancreas leads to an increase of echogenicity. In the aged, a very high
echogenicity is a normal ultrasonic finding. The pancreatic duct diameter also
increases with advancing age. Even in advanced age, a diameter of more than 3 mm,
however, should be regarded as a pathological finding.
PMID- 10671807
TI - Effects of endurance training on selected parameters of immune function in
elderly women.
AB - BACKGROUND: Immune function decreases with age, rendering the elderly more
susceptible to infection and tumor development. In addition, intense exercise has
been shown to decrease immune function in some populations. Few studies have
examined the effects of exercise on immune function in the elderly and, to our
knowledge, no studies have examined the effects of exercise on a population of
active, but nonexercising elderly. OBJECTIVE: The purpose of this study was to
examine the effects of a 10-week endurance training program on selected
parameters of immune function in active elderly women. METHODS: A total of 29
healthy, active women, aged 70-87, were randomly assigned to either an exercise
(76 +/- 5 years, n = 15) or control (77 +/- 6 years, n = 14) group. The exercise
group walked 3 days/week at 70% heart rate reserve (HRR). The duration on day 1
was 20 min and it was increased by 5 min each day until subjects were walking for
50 min (week 3). It remained at 50 min for the duration of the study, while
controls maintained normal activity. Blood samples were obtained from both groups
at rest, and from the exercise group after 20 min of walking at 70% HRR and after
2 h of recovery. Blood samples were collected prior to endurance training and
again after 10 weeks of endurance training. RESULTS: There was a significant
decrease in 1-mile walk times as well as heart rate at completion of the walk in
the exercise group. Natural cell-mediated cytotoxicity (NCMC) was significantly
higher post-exercise, compared to pre-exercise both before and after training.
After training it remained significantly elevated 2 h post-exercise. The resting
NCMC was significantly decreased in controls at week 10 but not in the exercise
group. CONCLUSION: Ten weeks of endurance training resulted in a significant
decrease in both the 1-mile walk time and the post-walk heart rate in the
exercisers but not the controls, without resulting in either an acute or chronic
suppression of immune function. Further, endurance training may lead to an
attenuation of the decrease in cellular immune measures which occurs during the
winter, since the control group experienced a decrease in NCMC and the exercisers
did not.
PMID- 10671808
TI - Natural death.
AB - BACKGROUND: The increasing age of every human being is the beginning of the end
of life, an obviously natural process, but any attempt to define the term
'natural death' soon encounters difficulties in defining what is meant by
'natural'. In the industrialized countries of the West, for example 'natural
death' is thought of as the opposite of non-natural types of death such as
accidental death, suicide, and homicide. OBJECTIVE: The aim of our present survey
is to discuss the meaning of the term 'natural death' under a clinical, a
forensic and a scientific point of view with regard to recent developments
especially in molecular biology. CONCLUSION: If there are 'external' physical
influences, a medical-technical manipulation, a therapeutic or molecular
biological intervention cannot be definitely ruled out as the cause of death,
then use of the term 'natural death' in general is open to question. It will only
remain meaningful if it can be applied with a specific meaning in definite
practical situations. Current research and medical technology, however, do not
allow use of the term 'natural death' in its conventional sense: it can thus be
stricken from the medical vocabulary.
PMID- 10671809
TI - Prognosis of elderly patients with dysphagia in Japan.
PMID- 10671810
TI - Effect of danazol and ovariectomy on matrix metalloproteinases in rat uteri.
AB - The experiments described in this report were designed to study the effects of
danazol on matrix metalloproteinases in the rat uterus. Proteinases were analyzed
by zymography in gels copolymerized with either gelatin or transferrin. There
were no apparent effects of danazol on proteinases from rat uteri when analyzed
in gelatin gels. However, in transferrin gels, not only did more bands appear in
control samples but also there was a clear negative effect of danazol on the
production of these proteinases. Similar results were obtained from uteri of
ovariectomized rats. Again no differences were observed in gelatin gels but the
control bands which appeared only on transferrin gels were missing in transferrin
gels as a result of ovariectomy. These results indicate that there is an effect
of estrogen on the synthesis of specific matrix metalloproteinases in the rat
uterus and that these proteinases are only observed by zymography when gels are
developed in transferrin but not collagen.
PMID- 10671811
TI - Placental levels of human decidua- associated protein 200 in normal pregnancy and
missed abortion.
AB - Levels of human decidua-associated protein (hDP)200 were measured in homogenized
placental tissue samples obtained from 26 induced and 24 missed abortions at 8-23
weeks of pregnancy. No significant difference in the level of placental hDP200
was observed comparing normal pregnancies and missed abortions. Moreover, no
significant change in the level of placental hDP200 was demonstrated throughout
normal pregnancies and those ending with missed abortions. Our results show that
the level of hDP200 in placental tissue, measured by double-site ELISA, is
probably incompatible with the normal continuation of pregnancy.
PMID- 10671812
TI - Factor XII deficiency in women with recurrent miscarriage.
AB - Congenital thrombophilia is known to cause significant maternal complications,
and possibly has an adverse effect on normal fetal development. The aim of this
study was to assess the prevalence of factor XII (FXII) deficiency in women with
a history of recurrent miscarriage. Two hundred and forty-one consecutive
Japanese women with a history of two or more recurrent miscarriages were
prospectively assessed for their etiology by conventional screening methods.
Seven women were found to have reduced FXII activity (19. 2-46.1%) and prolonged
activated partial thromboplastin time (33. 3-51.3 s). Of these 7 women, 6 had
experienced early pregnancy losses, while 1 woman had experienced repeated mid
trimester fetal losses with coincidental gestational thrombocytopenia. In 241
women with a history of recurrent miscarriage, the prevalence of FXII deficiency
was 2.9%.
PMID- 10671813
TI - Nitric oxide affects angiotensin II pressor response: possible mechanism of
attenuated pressor response during pregnancy and etiology of pregnancy-induced
hypertension.
AB - OBJECTIVE: To investigate the mechanism of attenuated pressor responses to
several vasoconstrictors during gestation, we sought to characterize the effects
of N(G)-monomethyl-L-arginine (L-NMMA) and L-arginine (L-Arg) on the pressor
response to the infusion of angiotensin II in rats. METHODS: L-NMMA and L-Arg
were infused intraperitoneally into rats at a constant rate by means of an
osmotic minipump. The L-NMMA group received an infusion of L-NMMA (3 mg/day)
daily for 13 days, whereas the L-NMMA plus L-Arg group received L-NMMA (3 mg/day)
daily for 4 days, followed by L-NMMA plus L-Arg (12 mg/day) daily for 9 days.
Sham-operated rats served as controls. The animals were anesthetized on day 13,
and catheters were placed into the femoral artery and vein. After the animals had
recovered from anesthesia, the pressor response to intravenous bolus doses of
angiotensin II (50, 100, 200, and 400 ng/kg) were determined after recovery from
anesthesia. RESULTS: While the baseline mean arterial blood pressure was not
affected by L-NMMA, with or without L-Arg, the pressor response to angiotensin II
in the L-NMMA group was significantly increased as compared with that in the
control group, at doses of 50, 100, and 200 ng/kg. The response of the L-NMMA
plus L-Arg group did not differ significantly from that of the control group.
CONCLUSION: Results indicate that the infusion of a nitric oxide synthase
inhibitor, at a dose insufficient to produce hypertension, increases the pressor
response to angiotensin II.
PMID- 10671814
TI - Effects of inflammatory cytokines on prostaglandin E(2) production from human
amnion cells cultured in serum-free condition.
AB - The effects of five inflammatory cytokines, i.e. interleukin(IL)-1alpha, IL
1beta, IL-6, IL-8 and tumor necrosis factor-alpha (TNF-alpha) on prostaglandin
E(2) (PGE(2)) production from amnion cells cultured in a serum-free condition was
evaluated. After human amnion cells obtained from term placenta were incubated
with the inflammatory cytokines at various concentrations, PGE(2) production in
the culture supernatant was determined using an enzyme immunoassay method. Under
a serum-free culture condition, an increase in PGE(2) production by IL-1alpha and
IL-1beta was observed at concentrations of 10 and 100 ng/ml compared to control
cultures. However, the increases in PGE(2) production by IL-6 and IL-8 were found
at relatively high concentrations, i.e. at 100 and 200 ng/ml. TNF-alpha induced a
significant increase in PGE(2) production at 50 and 100 ng/ml, but not at 200
ng/ml. These data suggest that these inflammatory cytokines directly stimulate
PGE(2) production from amnion cells and may initiate premature labor if amniotic
inflammatory cytokines are elevated, e.g. following intrauterine infection.
PMID- 10671815
TI - The incidence of pregnancy rhinitis.
AB - The purpose of this study was to define the cumulative incidence of pregnancy
rhinitis, and to study whether smoking, asthma, hayfever or month of conception
are risk factors. A questionnaire was delivered during 1 year in 10 antenatal
care centers in one Swedish county. Questions were asked by midwives on the
ordinary check-up visits throughout pregnancy. Five centers with response rates
of 70% or more, including 599 women, were evaluated. The cumulative incidence of
pregnancy rhinitis was 22%. Smokers had a significantly increased incidence with
a relative risk enhancement of 69%, whereas hayfever, asthma, and month of
conception had no statistically significant influence on incidence. Pregnancy
rhinitis was shown to appear at any time during gestation.
PMID- 10671816
TI - Aspiration of simple pelvic cysts during pregnancy.
AB - Traditional management of persistent ovarian cysts in pregnancy is explorative
laparotomy at 16-20 weeks of gestation and resection of the tumor. Scheduling
surgery to this time of pregnancy is accepted in order to prevent abortions that
are common whenever surgery is done in the first trimester, without delaying
treatment of ovarian tumors which harbor a malignant potential. In the following
article we report of 10 cases where simple ovarian cysts diagnosed during
pregnancy were successfully treated by sonographically guided cyst aspiration.
This new approach is justified with no fear of missing a malignant ovarian tumor
due to strict ultrasonic characteristics of benign cysts that include unilocular
simple appearing cyst with no solid echogenic parts, septations or papillary
structures. For 5 of the 10 women undergoing aspiration, this constituted the
definitive treatment, while the remaining 5 were later operated. We conclude that
aspiration of simple cysts during pregnancy is safe, may save surgical
intervention and in some cases this will be the definitive treatment.
PMID- 10671817
TI - Hormonal parameters in gestational diabetes mellitus during the third trimester:
high glucagon levels.
AB - Hormonal parameters during the last trimester of pregnancy contribute to a
natural increase of insulin resistance. It is not known whether any of these are
further involved in the manifestation of gestational diabetes mellitus (GDM) in
affected individuals. Basal levels of adrenocorticotropic hormone, cortisol,
growth hormone, insulin-like growth factor-I, prolactin, glucagon, estradiol,
progesterone, human placental lactogen and human chorionic gonadotropin were
investigated in 15 nonobese women with GDM and 26 matched normal pregnant women
(N). A linear discriminant analysis was performed to further compare the
predictive value of the basal hormone levels. Plasma glucagon levels were
significantly higher in the GDM group (p = 0.014); this difference was even
higher (p = 0.007) when the number of women was increased (GDM = 33, N = 62). No
significant differences were found in the levels of any of the other hormones. It
is not clear whether elevated glucagon levels have any involvement in the
pathogenesis of GDM or simply reflect the relative insulin deficiency of these
women.
PMID- 10671818
TI - Alterations in the immune system of patients with imminent preterm labour.
AB - Premature labour is the major cause of perinatal morbidity and mortality. The
aetiology of most cases of preterm labour remains unknown. We tried to estimate
whether immunological changes are present in patients with preterm labour.
Fourteen patients with imminent preterm labour and 12 healthy women with
uncomplicated pregnancies were included in the study. The specific lymphocyte
antigens were determined using direct staining with monoclonal antibodies and
analysed by flow cytometry. We observed that CD8+ lymphocyte percentage was
significantly lower in the group of patients with preterm labour when compared to
controls (p < 0.001). This deficit was related to T CD8+11b+ suppressor
lymphocytes, while the percentage of T CD8+11b- cytotoxic lymphocytes did not
differ in both studied groups. Furthermore, the percentage of T CD3+ lymphocytes
was significantly lower and that of B CD19+ cells higher in the study group when
compared to controls. Similarly, the percentage of CD4+45RA naive cells was
higher in the group of patients with imminent preterm labour, while the
percentage of memory CD4+45RO+ cells was lower in the study group in comparison
with the control group. These observations suggest that alterations in maternal
immunological parameters can be associated with the mechanisms mediating preterm
labour.
PMID- 10671819
TI - Relative abundance of placental pro-atrial natriuretic factor mRNA in normal
pregnancy and pre-eclampsia.
AB - Atrial natriuretic factor (ANF), produced by cytotrophoblast cells of the human
placenta, may be involved in the regulation of uteroplacental blood flow. Pre
eclampsia is associated with maternal hypertension and reduced uteroplacental
perfusion. The relationship between pre-eclampsia and placental production of ANF
is not known. This study measured pro-ANF mRNA levels by Northern blot analysis
in placentae delivered by caesarean section at preterm and term gestations from
women with normotensive and pre-eclamptic pregnancies and found no significant
difference between pre-eclampsia and normal pregnancy at either gestation. This
result suggests that placental production of ANF is not altered at the
pretranslational level during pre-eclampsia.
PMID- 10671820
TI - Serum leptin profiles in the normal menstrual cycles and gonadotropin treatment
cycles.
AB - Circulating levels of leptin, estradiol (E(2)) and progesterone (P(4)) throughout
normal menstrual cycles (n = 13), and controlled, stimulated cycles (n = 33) were
examined using sensitive specific radioimmunoassays in order to investigate the
relationships between sex hormones (E(2), P(4)). Serum leptin levels during the
normal menstrual cycle remained constant. However, in the ovulation induction
cycle, E(2) levels and circulating leptin levels increased in parallel with the
process of stimulation. In addition, leptin/body mass index ratios for all
samples were significantly correlated with log(10)E(2). We conclude that
particularly high levels of E(2) may have an effect on the secretion of leptin
from adipose tissue.
PMID- 10671821
TI - Implications of asymptomatic endocervical leukocytosis in infertility.
AB - Genital tract infection is a known cause of male and female infertility. In this
retrospective study, we investigated the effect of treatment of asymptomatic
cervical leukocytosis on pregnancy rates. Twenty-five infertile women with
asymptomatic cervical leukocytosis received broad-spectrum antibiotic treatment
(100 mg doxycycline, 200 mg ofloxacin, and 500 mg metronidazole twice a day for 7
10 days). Pregnancy rates and resolution of leukocytosis were evaluated 6 months
after treatment. Eleven patients (44%) had persistent cervical leukocytosis and
16 (64%) had become pregnant within 6 months after treatment. Successful
treatment of cervical leukocytosis resulted in an increase in the pregnancy rate:
13 of the 14 patients (93%) who were cured of leukocytosis became pregnant, while
3 of the 11 (27%) who did not become pregnant were cured (p = 0.002). Patients
who did not achieve pregnancy were older (p = 0. 002) than those who did.
Patients who were not cured were also older than those who were (p = 0.014). Our
findings suggest that the treatment for cervical leukocytosis is less effective
for older patients than for younger patients. However, treatment of asymptomatic
cervical leukocytosis appears to help preserve the fertility of patients with
this disease.
PMID- 10671822
TI - Follow-up of patients with unexplained infertility who previously underwent
natural cycle in vitro fertilization.
AB - One hundred and seventeen couples with unexplained infertility who underwent
natural cycle in vitro fertilization (NIVF) in the years 1991-1993 at the
Sheffield Fertility Centre (SFC) formed the basis of this analysis, where they
were followed in the following years. Seventy-six of the 117 patients who did not
conceive came back for further treatment and they were offered either stimulated
intrauterine insemination (SIUI) or stimulated in vitro fertilization (SIVF). If
fertilization was confirmed at NIVF they then received SIUI for three treatment
cycles and a change to SIVF treatment. If fertilization was not confirmed at NIVF
they were then subjected to SIVF. Only 41 patients out of 117 (35%) did not come
back for further treatment. The remaining 76 patients (65%) had 130 cycles of
treatment, 58 cycles of SIUI and 72 cycles of SIVF. An implantation rate of 23.4%
per cycle completed was achieved in the SIUI group. The rate of implantation for
the SIVF group was 19.4% per cycle completed. We conclude that patients with
unexplained infertility who failed fertilization at NIVF showed fertilization and
implantation at SIVF and SIUI, and the implantation rate was similar in both
groups.
PMID- 10671824
TI - High-risk pregnancy in beta-thalassemia major women. Report of three cases.
AB - Reproductive failure is common in beta-thalassemia major patients because of
endocrine damage resulting from iron overload. Here 3 full-term pregnancies
following spontaneous ovulation in 2 splenectomized beta-thalassemia major women
are reported. The main echocardiographic parameters, such as left ventricular end
diastolic and end-systolic diameters, fractional shortening and ejection
fraction, were within the normal range before pregnancy, but worsened during
gestation, and 1 patient developed pre-congestive heart failure. Deferoxamine
therapy was continued throughout 2 pregnancies, while in the other it was stopped
after 8 weeks: no abnormalities were noted in the children. Thanks to the
currently applied therapies, an increased number of pregnancies may now be
expected in beta-thalassemia major women: it is important to find out more about
the pregnancy-related problems and their management in these patients.
PMID- 10671823
TI - Endothelial nitric oxide synthase expression in leiomyoma and parental
myometrium.
AB - The aim of this study was to determine the expression of endothelial nitric oxide
synthase (eNOS) in leiomyomatous tissue as a possible mediator of the growth
process. Nine patients had myoma enucleation during the follicular phase. The
myomata and adjacent myometrial tissues were fixed in formol until study.
Immunohistochemical localization of leiomyomatous and myometrial tissue eNOS
expression was performed using specific monoclonal antibodies to eNOS.
Statistical comparisons were made using the Mann-Whitney Wilcoxon rank-sum test
for the expression of eNOS. The test was considered significant when p values
were <0.05. Immunostaining for eNOS was seen in the cytoplasm of myometrial
endothelial and smooth muscle cells in both tissue sections. eNOS expression was
significantly higher in the smooth muscle cells of leiomyomata, compared to
parental myometrium (p < 0.0005). The expression of eNOS in vascular endothelial
cells was not different in the leiomyoma and myometrium (p > 0.05). To our
knowledge, this is the first study to document marked expression of eNOS in
leiomyomatous tissue, compared to parental myometrium. We also conclude that the
mechanism(s) of the growth-promoting effect of estrogen on leiomyomata is
mediated by more synthesis of NO.
PMID- 10671825
TI - Severe unilateral hydrothorax as the only manifestation of the ovarian
hyperstimulation syndrome.
AB - BACKGROUND: Unilateral hydrothorax is rarely the sole manifestation of the
ovarian hyperstimulation syndrome (OHSS) and is suggestive of the severity of the
disease. CASE: A 35-year-old woman presented with mild dyspnea 2 weeks after
ovarian stimulation with hMG and hCG and IVF-ET. Chest X-ray revealed a large
pleural effusion on the right side. Three consecutive thoracocenteses were needed
to drain a total of 6,800 cm(3) of fluid. Following drainage, the respiratory
symptoms disappeared. An uneventful pregnancy is in progress. CONCLUSIONS:
Thoracocentesis is safe and efficient for the treatment of hydrothorax and may be
repeated as often as necessary. Clinicians should be aware of the possibility of
unilateral hydrothorax as the sole symptom of OHSS.
PMID- 10671826
TI - Magnetic resonance imaging diagnosis of metastasis of chronic myelocytic leukemia
to the uterus.
AB - We report a case of chronic myelocytic leukemia (CML) in which the initial
manifestation of blastic crisis was massive genital bleeding. The bleeding was
diagnosed as being caused by CML metastasis to the uterus on the basis of the
magnetic resonance imaging findings.
PMID- 10671827
TI - Cognitive behavior therapy in panic disorder and comorbid major depression. A
naturalistic study.
AB - BACKGROUND: There is a lack of evidence about the effectiveness of cognitive
behavior therapies (CBT) in settings of routine clinical care as well as in the
treatment of panic and comorbid disorders. METHODS: We investigated a group
oriented CBT approach for 80 patients with panic disorder including 35 patients
with current comorbid major depression. Assessments took place 6 months before
treatment, at the beginning and end of treatment, and 1 year later. Structured
interviews and multiple clinical self-rating scales were used. RESULTS: Panic
patients with comorbid major depression showed higher anxiety-specific and
nonspecific pathology. The most striking benefits were in reducing avoidance
behavior, while improvements concerning catastrophic beliefs were smaller, but
still significant. For most self-rating scale results, patients with and without
comorbid depression improved to a comparable degree. However, the end-state
functioning of patients with panic disorder and current comorbid depression at
admission is significantly lower than for patients with panic disorder alone.
CONCLUSIONS: The results point to the necessity to develop and improve treatment
approaches for patients with comorbidity of panic disorder and current major
depression.
PMID- 10671828
TI - Impact of management change and an intervention program on health care personnel.
AB - BACKGROUND: There has been a major shift in the organization and responsibility
for the provision of geriatric care in Sweden. This was believed to be stressful.
We therefore decided to launch a controlled intervention program on health care
personnel aimed at enhancing their adaptation and ability to cope. The purpose of
this study was to assess the impact of management change on psychosocial
parameters of health care personnel and the effects, if any, of a structured
intervention program. METHODS: Two separate wards were randomly allocated to be
either intervention (I) or control (C) ward. The I-ward personnel were subjected
to a psychologist's structured 10-session intervention program for 20 weeks. The
program consisted of an initial educational part followed by a practical problem
solving discussion part. A structured questionnaire on psychosocial issues was
answered by the participants before (0 weeks), immediately after (20 weeks), and
10 weeks after the intervention (30 weeks). RESULTS: There were no significant
changes in the psychosocial parameters of the C-ward personnel. In the I-ward,
however, there was a significant increase in work demand as well as in positive
feelings about work, as compared to the C-ward at the 30-week follow-up. There
was also significantly better work comfort in the I-ward. CONCLUSIONS: We did not
find any anticipated negative psychosocial effects on health care personnel
undergoing an organizational change. However, by offering a structured
intervention program to one group of health care personnel, we found some
positive psychosocial effects. Future research is needed to pinpoint which factor
or factors in the intervention program were the most crucial for the effects to
occur.
PMID- 10671829
TI - Coping with unfair treatment at work--what is the relationship between coping and
hypertension in middle-aged men and Women? An epidemiological study of working
men and women in Stockholm (the WOLF study).
AB - BACKGROUND: An important hypothesis in psychosomatic medicine is that exposure to
psychosocial factors that arouse anger may accelerate the onset of hypertension,
particularly if the subject is not allowed to show anger or to deal
constructively with the factor that evoked it. For working men and women, being
treated in an unfair way at work may be crucial. The present study was designed
to answer the question whether the pattern of coping - primarily directed towards
the aggressor (open) or directed inwards or towards others (covert) - is
associated with hypertension among working men and women. STUDY GROUP: Five
thousand seven hundred and twenty working men and women aged 15-64 participated
in the study. The participation rate was 76%. METHODS: The coping pattern was
studied by means of a Swedish version of a self-administered questionnaire that
was originally introduced by Harburg et al. RESULTS: Significant results were
confined to the age group 45-54. All analyses were adjusted for age and body mass
index. Smoking habits and social class had no effect on the relationships. Low
scores (lowest quartile) for open coping tended to be associated with an elevated
prevalence ratio (PR) of hypertension both among men (PR 1.3, 95% confidence
interval, CI, 0.9-1.7) and women (PR 1.4, 95% CI 1.0-2.0). High scores for covert
coping (highest quartile) were associated with an elevated PR of hypertension
among men (PR 1.6, 95% CI 1.2-2.2) but not in women. If the analysis was confined
to cases without medication, the relationship between a high level of covert
coping and high blood pressure was still significant for men. For women, however,
no significant findings were made after this operation. Accordingly, the
relationship between a low level of open coping and hypertension in women was
confined to women with medication. Coping patterns were correlated with
psychosocial work environment factors, in particular decision latitude.
CONCLUSION: In men, covert coping was associated with prevalence of hypertension.
In women, there tended to be a relationship between low scores for open coping
and hypertension.
PMID- 10671830
TI - Social support and psychological distress in primary care attenders. Ferrara SIMG
Group.
AB - BACKGROUND: Growing evidence has been collected about the high prevalence of
psychological distress in primary care. The role of psychosocial variables,
namely the role of support from the patients' interpersonal ties, has not been
extensively explored. METHODS: The study investigated the relationship between
perceived social support, as evaluated by the Multidimensional Scale of Perceived
Social Support, and psychological distress, as measured by the Brief Symptom
Inventory, in 1,341 primary care attenders. RESULTS: In comparison with highly
supported patients, lowly supported subjects showed higher scores on distress
dimensions (e.g. depression, anxiety, phobia) and a higher prevalence of
psychological morbidity ('caseness' = 37.3 vs. 11%). CONCLUSION: The findings
suggest that, in the setting of primary care, the GPs' assessment of their
patients' social support system may be useful in identifying those more
vulnerable to psychological stress.
PMID- 10671831
TI - The relationship between semantic organization and memory in obsessive-compulsive
disorder.
AB - BACKGROUND: A variety of evidence suggests that frontostriatal dysfunction is
involved in obsessive-compulsive disorder (OCD). This evidence includes both
neuroimaging findings and results from studies using neuropsychological
assessments. Previous studies have documented nonverbal memory deficits in
individuals with OCD, whereas verbal learning and memory were less affected.
METHODS: The present study examined both verbal and nonverbal memory in a sample
of 17 untreated outpatients with OCD. We also evaluated the effects of encoding
strategies which are believed to be mediated by frontostriatal system
functioning. RESULTS: OCD patients were significantly impaired in both verbal and
nonverbal memory performance. This deficit was correlated with impairments in
organizational and semantic clustering strategies at the time of encoding.
CONCLUSIONS: Deficits in organizational strategies are consistent with
frontostriatal dysfunction models in OCD.
PMID- 10671832
TI - Dissociative disorder associated with a colloid cyst of the third ventricle:
organic or psychogenic amnesia?
PMID- 10671833
TI - A case report showing that subclinical hypothyroidism rather than hyperthyroidism
stabilizes rapidly cycling bipolar illness.
PMID- 10671834
TI - Stress in trainee anaesthetists.
PMID- 10671835
TI - The New Deal - a poor deal for service and training?
PMID- 10671836
TI - Airway obstruction with cricoid pressure.
AB - Cricoid pressure may cause airway obstruction. We investigated whether this is
related to the force applied and to the technique of application. We recorded
expired tidal volumes and inflation pressures during ventilation via a face-mask
and oral airway in 52 female patients who were anaesthetised and about to undergo
elective surgery. An inspired tidal volume of 900 ml was delivered using a
ventilator. Ventilation was assessed under five different conditions: no cricoid
pressure, backwards cricoid pressure applied with a force of 30 N, cricoid
pressure applied in an upward and backward direction with a force of 30 N,
backwards cricoid pressure with a force of 44 N and through a tracheal tube. An
expired tidal volume of < 200 ml was taken to indicate airway obstruction. Airway
obstruction did not occur without cricoid pressure, but did occur in one patient
(2%) with cricoid pressure at 30 N, in 29 patients (56%) with 30 N applied in an
upward and backward direction and in 18 (35%) patients with cricoid pressure at
44 N. Cricoid pressure applied with a force of 44 N can cause airway obstruction
but if cricoid pressure is applied with a force of 30 N, airway obstruction
occurs less frequently (p = 0.0001) unless the force is applied in an upward and
backward direction.
PMID- 10671837
TI - A comparison of patient-controlled epidural analgesia following gynaecological
surgery with and without a background infusion.
AB - We conducted a randomised, controlled study to investigate the effect of adding a
background infusion to patient-controlled epidural analgesia for postoperative
pain relief. Forty-two patients scheduled for elective lower abdominal
gynaecological surgery received patient-controlled epidural analgesia
postoperatively using a mixture of 0.2% ropivacaine and 2.0 microg x ml-1
fentanyl. Patients in group B (n = 20) were given a background infusion of 5 ml x
h-1, whereas those in group N (n = 21) were not. There was no difference in pain
scores or patient satisfaction scores between the two groups. Patients in group B
had a higher total drug consumption (156.8 +/- 34.8 ml vs. 89.5 +/- 41.0 ml; p <
0.0001) and incidence of side-effects (71.4% vs. 30.0%; p = 0.007). Motor
blockade during the 24-h study period was also greater in group B (median [range]
area under the curve 7.5 [0.0-39.0] h vs. 3.0 [0.0-36.0] h; p = 0.035). We
conclude that the addition of a background infusion to patient-controlled
epidural anaesthesia is not recommended as it confers no additional benefits.
PMID- 10671838
TI - Haemoconcentration by gelatin-induced acceleration of erythrocyte sedimentation
rate.
AB - Erythrocyte sedimentation rates from 40 suspensions of packed red blood cells in
modified fluid gelatin, 4% albumin solution, 6% hydroxyethyl starch and normal
saline were measured at room temperature using Westergren's method. The
erythrocyte sedimentation rate was extremely high in gelatin and this increase
was significant after 10-60 min when compared with the other fluids. Erythrocyte
sedimentation rates in albumin, hydroxyethyl starch and normal saline were low
and there were no differences between these fluids [erythrocyte sedimentation
after 60 min, median (interquartile range): gelatin 128 (111.2-130.0) mm, albumin
2 (1.5-2.0) mm, hydroxyethyl starch 1.5 (1.0-1.6) mm, normal saline 2 (1.9-2.5)
mm, p < 0.0001]. The addition of twice the volume of modified fluid gelatin to a
volume of red blood cells leads to rapid acceleration of the erythrocyte
sedimentation rate. This is caused by increased erythrocyte aggregation, and in
clinical practice this effect may be useful for the haemoconcentration of diluted
blood from cardiopulmonary bypass circuits or cell-saver autotransfusion in
paediatric surgery.
PMID- 10671839
TI - Risk factors for pressure sores in the critically ill.
AB - Pressure sore development in the critically ill is a well-recognised problem and
several risk factors have been put forward as being relevant; however, none has
been proved valid in this population. This study examines the effects of specific
risk factors for the development of pressure sores in the critically ill. Data on
22 specific risk factors were recorded every 8 h. Of 286 patients who were
identified as having a minimum set of three predetermined risk factors, 77
developed pressure sores. Using univariate regression analysis, 18 of the 22
specific factors were identified as being significant (p < 0.05) in the
development of pressure sores. Multivariate analysis identified five of these 18
specific risk factors as being independently significant (p < 0.05) in pressure
sore development. These five factors were norepinephrine infusion, APACHE II
score, faecal incontinence, anaemia and length of stay.
PMID- 10671840
TI - Evoked potential monitoring in anaesthesia and analgesia.
AB - Electrophysiological monitoring of selected neural pathways of the brain,
brainstem, spinal cord and peripheral nervous system has become mandatory in some
surgery of the nervous system where preventable neural injury can occur. Evoked
potentials are relatively simple methods of testing the integrity of various
aspects of the nervous system. This review covers the variety of evoked
potentials that can be monitored and outlines the principles of their
measurement. Their use in specific situations and how factors such as anaesthesia
might affect them is presented.
PMID- 10671841
TI - Bispectral index monitoring: comparison of two types of electrode.
AB - Bis-monitoring is a new method of monitoring anaesthetic depth. Bis-monitoring is
easy to perform, but the Bis-monitor and the original, disposable electrodes are
expensive. The aim of this study was to determine whether the original Zipprep
electrodes could be replaced by the much cheaper electrocardiogram electrodes. We
compared bispectral index measurements, conducted using both types of electrode
in the same patients before anaesthesia, and during light and deep anaesthesia,
in patients randomly allocated to receive either sevoflurane or propofol
anaesthesia. We found very good agreement between the measurements from the two
different sets of electrodes. The impedance in the electrocardiogram electrodes
was higher than in the Zipprep electrodes, but this did not affect the bispectral
index. No other problems with either type of electrode were detected. It is
concluded that Zipprep electrodes can be replaced by electrocardiogram electrodes
in normal clinical practice.
PMID- 10671842
TI - Evaluation of a needle-free injection system for local anaesthesia prior to
venous cannulation.
AB - We evaluated a single-use, disposable, carbon-dioxide-powered, needleless
injector (J-Tip, National Medical Products Inc., CA, USA), which is claimed to
deliver a virtually painless, subcutaneous injection. Seventy-two patients
undergoing various types of surgery had a large-bore intravenous cannula inserted
prior to induction of general anaesthesia. Three minutes beforehand, a
subcutaneous injection of 0.3 ml of 1% plain lidocaine was administered. Subjects
were randomly allocated to receive the lidocaine either by the needleless
injector or from a conventional syringe and a 25 G needle. Pain scores were
recorded on injection of the lidocaine and on insertion of the cannula. There was
significantly less pain on injection with the needleless injector than with the
25 G needle (p < 0.001) but, surprisingly, there was more pain on cannulation (p
< 0. 001). We conclude that the device certainly delivers a less painful
subcutaneous injection than a 25 G needle, but perhaps provides less effective
skin anaesthesia for venous cannulation at sites where the subcutaneous space is
small; its use might be better suited to areas where the subcutaneous space is
deeper.
PMID- 10671843
TI - An assessment of the thermal safety of microwave warming of crystalloid fluids.
AB - We performed an in vitro study to determine the thermal safety of a domestic
microwave to warm intravenous crystalloid solutions. Five-hundred-millilitre bags
of crystalloid, randomly allocated to groups which differed in power setting,
timer setting and whether or not agitation was performed after warming, were
heated in a microwave oven to a calculated temperature of 39 degrees C. Timer
accuracy was checked by stopwatch. Bag temperature was measured using an infrared
tympanic temperature probe and fluid temperature was measured with an in-line
thermocouple. Mean times measured by stopwatch were higher than set. No in-line
temperatures reached 40 degrees C. Wider overall ranges and a higher mean were
found with the tympanic probe compared with in-line temperature measurement.
There were significant differences between the in-line temperatures of shaken and
unshaken bags at each power setting, but not when groups were added together.
There was no change in colour or odour of bags or fluid. One bag developed a
pinhole leak when the packaging was removed.
PMID- 10671844
TI - Target-controlled infusion of propofol and remifentanil combined with bispectral
index monitoring for awake craniotomy.
AB - We describe the target-controlled administration of propofol and remifentanil,
combined with monitoring of the bispectral index, during an awake craniotomy for
removal of a left temporo-parietal tumour near the motor speech centre. Target
concentrations of the two drugs were adjusted according to the patient's
responses to painful stimuli and surgical events, and the need for speech
testing. Allowing the effect-site concentrations of propofol and remifentanil to
decrease during surgery allowed the performance of cortical speech mapping and
the testing of the patient's ability to speak. Although the bispectral index was
not used as a guide for the administration of the drugs, its value correlated
better with the patient's responsiveness than did the predicted effect-site
concentrations of propofol. Side-effects, comprising hypotension, respiratory
depression and airway obstruction, were related to rapid increases in drug
infusion rates and were easily managed.
PMID- 10671845
TI - Towards a pain-free venepuncture.
AB - A randomised, prospective trial was conducted to assess the efficacy of various
means of alleviating the pain of subcutaneous lidocaine infiltration. One hundred
and twenty-two patients were randomly allocated to different groups to receive
buffered lidocaine 1%, warmed lidocaine 1% or infiltration by the counter
irritation technique. A visual analogue pain score was recorded at different
stages of cannulation and results showed that pain scores were significantly
lower in the group receiving buffered lidocaine 1% (p < 0.02) and in the counter
irritation group (p < 0.05). Thus buffering lidocaine 1% and administration of
lidocaine 1% by the counter-irritation technique is effective in relieving the
pain of lidocaine infiltration.
PMID- 10671846
TI - The effect of cricoid pressure on the cricoid cartilage and vocal cords: an
endoscopic study in anaesthetised patients.
AB - Cricoid pressure is used to protect the lungs from contamination with gastric
contents during tracheal intubation. We studied the effect of cricoid pressure
applied with a yoke on 30 anaesthetised patients examined fibreoptically through
a laryngeal mask airway. We assessed the effect of 20, 30 and 44 N on the
internal appearance of the cricoid and vocal cords. Difficulty in ventilation was
also recorded. At 44 N, cricoid deformation occurred in 27/30 patients (90%) and
15/30 (50%) had cricoid occlusion [13/30 (43%) had cricoid occlusion at 30 N and
7/30 (23%) at 20 N]. Associated difficulty in ventilation was present in 15
patients (50%) and 18/30 (60%) had vocal cord closure with associated difficult
ventilation, at forces up to 44 N. Cricoid occlusion was unrelated to age and
body mass index but females were at greater risk. Orthodox values of cricoid
pressure, applied with a yoke, may produce obstruction at the level of the
cricoid cartilage or vocal cords, with implications for tracheal intubation and
ventilation by mask.
PMID- 10671847
TI - Effect of clonidine premedication on haemodynamic responses to fibreoptic
bronchoscopy.
AB - The usual haemodynamic response to fibreoptic bronchoscopy is an increase in
heart rate and blood pressure. We therefore compared, in a prospective,
randomised, double-blind study, the effect of two doses of oral clonidine
premedication (150 microg or 300 microg) with placebo (control group) on the
haemodynamic alterations in 62 patients who underwent elective fibreoptic
bronchoscopy. Significant increases in blood pressure and heart rate were
observed during fibreoptic bronchoscopy only in the control group. Clonidine 150
microg blunted the haemodynamic response to fibreoptic bronchoscopy (p < 0.05).
Significant decreases in systolic blood pressure (< 90 mmHg) were observed in all
patients premedicated with 300 microg clonidine. Throughout the study nine
patients (75%) in the 300 microg clonidine group were treated at least once for
hypotension. Compared with the control group, time to awakening was significantly
longer only in patients premedicated with 300 microg clonidine. In conclusion,
premedication with 150 microg oral clonidine attenuates haemodynamic responses to
fibreoptic bronchoscopy, without causing excessive haemodynamic depression and
sedation. These data encourage the administration of clonidine as premedication
in patients undergoing fibreoptic bronchoscopy, particularly in those with, or at
risk for, coronary artery disease.
PMID- 10671848
TI - A new practical classification of laryngeal view.
AB - A new practical classification of laryngeal view at laryngoscopy is presented and
evaluated. The best laryngeal view obtained with or without anterior laryngeal
pressure is recorded. The laryngeal view is easy (E) when the laryngeal inlet is
visible. The view is restricted (R) when the posterior glottic structures
(posterior commissure or arytenoids) are visible or the epiglottis is visible and
can be lifted; this includes some grade 2 and some grade 3 views as classified by
Cormack and Lehane. A difficult (D) view is present when the epiglottis cannot be
lifted or when no laryngeal structures are visible. Five hundred patients were
studied. Laryngoscopy, with the patient anaesthetised and paralysed, was
performed with a Macintosh laryngoscope. If the vocal cords were not visible, a
gum elastic bougie was used to aid intubation. Other aids were used only if this
did not allow intubation. Each laryngeal view was graded according to the new
classification and that of Cormack and Lehane. Intubation was timed and the
equipment needed to facilitate intubation was recorded. The new classification
stratified increasing difficulty with intubation (time for intubation longer and
increasingly complex methods needed) better than the Cormack and Lehane
classification. The new classification is as sensitive and more specific than the
Cormack and Lehane classification in predicting difficult intubation. It is also
more sensitive and more specific in predicting easy intubation.
PMID- 10671849
TI - Haemodynamic changes during laparoscopic anterior fundoplication measured by
trans-oesophageal Doppler ultrasound.
AB - We investigated the cardiovascular effects of pneumoperitoneum and steep head-up
tilt during laparoscopic fundoplication using an intra-oesophageal Doppler
ultrasound probe. Repositioning of the probe proved sufficient to maintain the
signal throughout the procedure despite the pneumomediastinum. There was a
statistically significant increase in mean arterial blood pressure and a fall in
stroke distance but not in systemic vascular resistance. Increasing or decreasing
the blood pressure with drugs improved stroke distance. The oesophageal Doppler
ultrasound proved a satisfactory method for assessing cardiovascular changes
during fundoplication.
PMID- 10671865
TI - BJU international volume 85, number 2, january 2000 european urology update
series 2000:1 prostatitis: lessons from the 20th century
PMID- 10671850
TI - Pretreatment with ketorolac and venous occlusion to reduce pain on injection of
propofol.
AB - We performed a randomised, double-blind, prospective trial to discover whether
intravenous ketorolac 10 mg made up to 2 ml with saline, with or without venous
occlusion for 2 min, reduces the pain on injection of propofol. In 90 patients,
pain scores were obtained during injection of propofol following pretreatment of
the vein with saline, ketorolac or ketorolac with venous occlusion. Pain on
injection of ketorolac was more common than with saline (p = 0.02). The incidence
of severe pain following propofol was reduced by ketorolac with venous occlusion
(p = 0.019) compared with saline or ketorolac without venous occlusion. There was
no difference in venous sequelae at 7 days postoperatively between the groups.
Our results suggest that pain on injection of propofol may be related to release
of local kininogens and that nonsteroidal anti-inflammatory drugs may have a role
in reducing that pain.
PMID- 10671866
TI - Prostatitis: lessons from the 20th century.
PMID- 10671867
TI - Acute urinary retention.
PMID- 10671868
TI - Transurethral electrovaporization and vapour-resection of the prostate: an
appraisal of possible electrosurgical alternatives to regular loop resection.
PMID- 10671869
TI - Human papillomavirus and urological tumours: II. Role in bladder, prostate, renal
and testicular cancer.
PMID- 10671870
TI - Drugs and intravenous contrast media.
PMID- 10671871
TI - Unilateral pedal lymphography in patients with filarial chyluria.
AB - OBJECTIVE: To evaluate the usefulness of unilateral pedal lymphography in
patients with filarial chyluria. PATIENTS AND METHODS: Of 114 patients with
filarial chyluria, all underwent lymphography (unilateral pedal in 106) and 55
underwent selective ureteric sampling for chyle. RESULTS: Unilateral pedal
lymphography in the 106 patients detected lymphaticorenal fistulae (LRF) in 104
(98%). Lymphatic crossover was seen in all 106 patients, from the second sacral
segment to the first lumbar segment. The most frequent crossover site was at the
L5 level (87%). There was complete correlation between the side of LRF and the
side of chyluria as assessed by selective ureteric sampling. CONCLUSION:
Unilateral pedal lymphography can detect LRF via lymphatic crossover even when it
is on the opposite side from that injected with contrast agent. The advantages of
unilateral lymphography over bilateral procedures are that it is easy to identify
crossover channels, and the discomfort for the patient is reduced because there
are fewer incisions and it is quicker. Unilateral lymphography is recommended as
the initial method when lymphography is indicated in filarial chyluria.
PMID- 10671872
TI - Is bowel preparation useful before radiography of the renal tract in patients
with spinal cord injury?
AB - OBJECTIVES: To assess, in a blinded study, the usefulness of bowel preparation in
improving the quality of radiography of the renal tract in patients with spinal
cord injury (SCI). PATIENTS AND METHODS: Plain abdominal radiographs of 56
patients with SCI were selected; 24 of the patients had received bowel
preparation and 32 had not. The films were independently assessed by one
radiologist and one urologist unaware of the treatment and identity of the
patients. Each film was divided into five regions of interest and scores of 1-4
(1 for least and 4 for best visibility) assigned to each area. In films with a
low aggregate visibility score (= 12), the cause of poor visibility was
assessed in relation to faecal residue and gas. RESULTS: The difference between
the overall mean visibility score for bowel-prepared and unprepared patients was
not statistically significant. In films with poor visibility, gas shadows
predominated over bowel shadows in the bowel-prepared group, although this trend
was not statistically significant. Of the five areas, the bladder was scored as
being the most clearly seen in both groups. CONCLUSIONS: These findings suggest
that bowel preparation does not increase the diagnostic value of radiographs of
the renal tract in patients with SCI.
PMID- 10671873
TI - Metallic stents for malignant and benign ureteric obstruction.
AB - OBJECTIVE: To report our experience of using metallic stents to treat ureteric
obstruction caused by malignant or benign disease. PATIENTS AND METHODS: Nine
patients with obstruction in 11 ureters caused by malignant or benign disease
(mean age 61 years, range 35-82, mean follow-up 7 months, range 3-11) were
treated using metallic stents. A balloon-expandable metallic stent was used in
one patient and self-expandable metallic stents in the remaining eight. All
stents were inserted via a percutaneous antegrade approach. RESULTS: Of the 11
ureters, nine remained patent with no further manipulation during the follow-up
of 3-11 months. An additional stent was placed in continuity with the first in
two ureters of two patients at 4 and 5 weeks after the first procedure because of
persistent obstruction. After the second intervention, their obstruction was
improved. Transient vesico-ureteric reflux occurred in two of three stented
distal ureters, but the reflux resolved spontaneously within 2 months after stent
implantation. Ureteric patency was maintained in all patients and no major
complications related to stenting occurred during the follow-up. Two patients
died from cervical cancer at 3 and 5 months after stenting. CONCLUSION: In
patients with difficult ureteric obstructions a metallic stent provides a safe
and effective alternative to an indwelling double-pigtail catheter or
percutaneous nephrostomy.
PMID- 10671874
TI - Early experience of intra-ureteric capsaicin infusion in loin pain haematuria
syndrome.
AB - OBJECTIVES: To evaluate early results of the intra-ureteric instillation of
capsaicin for the treatment of loin pain haematuria syndrome (LPHS). PATIENTS AND
METHODS: Ten patients with LPHS were treated using intra-ureteric capsaicin
instillation. A solution of capsaicin was infused into the affected ureter
through an embolectomy catheter, under anaesthesia. The success of the treatment
was assessed using patient questionnaires and the quantitative reduction in the
patients' analgesic requirements measured. RESULTS: During a mean follow-up of 6
months, six of the 10 patients had short- to medium-term symptomatic relief after
one or more treatments; four had no relief from their symptoms. One patient had a
mucosal ulceration in the bladder after extravasation of the capsaicin solution.
Two patients subsequently underwent simple nephrectomy for symptomatic
nonfunctioning kidneys. CONCLUSION: These results are consistent with other
preliminary reports of the efficacy of capsaicin treatment in LPHS and such
treatment therefore has a definite therapeutic role in this difficult condition.
We are uncertain if the treatment contributed to the deterioration of the excised
kidneys. This early experience suggests a need for careful consideration when
contemplating this treatment, with attention directed to both the initial
diagnosis and possibly the technique of capsaicin/instillation. We include a
protocol to follow when preparing patients for capsaicin treatment.
PMID- 10671875
TI - The effect of intravesical capsaicin on the suburothelial innervation in patients
with detrusor hyper-reflexia.
AB - OBJECTIVE: To determine the effect of intravesical capsaicin on the suburothelial
innervation in patients with detrusor hyper-reflexia, in whom a single dose of
intravesical capsaicin (1-2 mmol/L) increases the bladder capacity for 3-6
months. PATIENTS AND METHODS: Thirteen patients with detrusor hyper-reflexia
underwent cystometry and had flexible cystoscopic biopsies taken before and 6
weeks after receiving instillations of intravesical capsaicin (1 mmol/L). Similar
biopsies were also obtained from a control group of 12 neurologically normal
patients with microscopic haematuria and normal bladders. Frozen sections were
stained using antibodies to S100 and PGP 9.5. Using computerized analysis, the
mean nerve density scores were expressed as nerves/mm2 for S100-positive
structures and 'red%' and 'red in frame' for PGP 9.5. RESULTS: The mean (SEM)
functional bladder capacity increased from 193.2 (28.17) mL before to 396.3
(41.96) mL at 6 weeks after treatment with capsaicin, in nine of the 13 patients.
The mean nerve density of S100-positive structures in the control group was 83
(3.18) nerves/mm2. In hyper-reflexic patients who responded to capsaicin by
improved bladder capacity, the mean nerve density of S100-positive structures was
reduced from 100 (12.2) before to 66 (9.4) nerves/mm2 6 weeks after treatment. In
those who did not respond to capsaicin there was no significant difference in
these scores. Similarly the 'red%' and 'red in frame' reduced from 3.41 (1.06) to
1.15 (0.32) and 824.7 (246.3) to 297.9 (83.5) units, respectively, before and 6
weeks after capsaicin treatment. The difference in those not responding was not
significant. CONCLUSIONS: Intravesical capsaicin causes a reduction in
suburothelial nerve densities in the bladder of patients with detrusor hyper
reflexia. This may explain its prolonged beneficial effect in these patients.
PMID- 10671876
TI - The after-contraction: a true detrusor contraction or a late dyssynergic urethral
sphincter contraction?
AB - OBJECTIVE: To evaluate the mechanism and significance of the after-contraction,
recorded in bladder pressure by urodynamics, at the end of micturition. PATIENTS
AND METHODS: The urodynamic recordings showing an after-contraction of the
detrusor in 65 patients of all ages and with a variety of pathologies were re
examined. Special attention was directed to the anal or urethral sphincter needle
electromyographic activity and to the monitored urethral pressure, to determine
any relationships with the patterns of detrusor pressure. RESULTS: An after
contraction was noted in 61 patients with detrusor instability and in 11 with
urethral instability. In 59 patients it was evident that the after-contraction,
i.e. a renewed increase in detrusor pressure during the declining contraction,
correlated with a sphincter contraction preceding it by a fraction of a second.
Similar increases in detrusor pressure were apparent in patients with detrusor
sphincter dyssynergia throughout voiding. In six patients the relationship was
less clear mainly because there were artefacts in the curves. CONCLUSION: The
after-contraction arises by a sudden stopping of the outflow of urine, provoked
by a sphincter contraction. This may occur by involuntary dyssynergia or by an
early voluntary interruption of the voiding stream. The 'milk back' of urine from
the proximal urethra to the bladder and the inhibited detrusor contraction (if
the perineal contraction is prolonged) may cause some postvoid residual urine. It
occurs mainly in the presence of detrusor and/or urethral instability.
PMID- 10671877
TI - The effectiveness of terazosin, an alpha1-blocker, on bladder neck obstruction as
assessed by urodynamic hydraulic energy.
AB - OBJECTIVE: To investigate the effectiveness of terazosin, an alpha1-adrenoceptor
blocking agent, on bladder neck obstruction (BNO), by assessing the urodynamic
hydraulic energy profile. Patients, subjects and methods The study included 17
men (mean age 60.1 years, range 24-84), comprising 11 patients with BNO (mean age
66.5 years) and six normal volunteers (mean age 48.1 years). A five-transducer
microtip catheter was used to measure the pressure in the bladder and at the
bladder neck, and in the membranous and bulbous urethra during voiding. All the
subjects then received terazosin, 1 mg/day orally for 2 weeks, and were re
assessed. RESULTS: The bladder neck diameter at maximum flow significantly (P <
0.02) increased in the 11 patients with BNO after treatment with terazosin. The
relative hydraulic energy profiles before terazosin treatment showed the greatest
hydraulic energy loss between the membranous and the bulbous urethra in the
normal subjects, and between the bladder neck and the membranous urethra in the
men with BNO. After terazosin treatment, the greatest energy loss was between the
membranous and the bulbous urethra in men with BNO, similar to that in the normal
controls, i.e. the whole profile of relative hydraulic energy became normal.
CONCLUSION: Terazosin was effective in opening the bladder neck and improving the
hydraulic energy profile in men with BNO.
PMID- 10671878
TI - Conservative treatment of urge urinary incontinence in women: a systematic review
of randomized clinical trials.
AB - OBJECTIVE: To assess the efficacy of physical therapies for first-line use in the
treatment of urge urinary incontinence (UUI) in women, using a systematic review
of randomized clinical trials (RCTs). MATERIALS AND METHODS: A computer-aided and
manual search was carried out for RCTs published between 1980 and 1999
investigating the treatment of UUI defined by the keywords 'physical therapies',
e.g. bladder (re)training (including 'behavioural' treatment), pelvic floor
muscle (PFM) exercises, with or without biofeedback and/or electrical
stimulation. The methodological quality of the included trials was assessed using
methodological criteria, based on generally accepted principles of interventional
research. RESULTS: Fifteen RCTs were identified; the methodological quality of
the studies was moderate, with a median (range) score of 6 (3-8.5) (maximum
possible 10). Eight RCTs were considered of sufficient quality, i.e. an internal
validity score of >/= 5.5 points on a scale of 0-10, and were included in a
further analysis. Based on levels-of-evidence criteria, there is weak evidence to
suggest that bladder (re)training is more effective than no treatment (controls),
and that bladder (re)training is better than drug therapy. Stimulation types and
parameters in the studies of electrical stimulation were heterogeneous. There is
insufficient evidence that electrical stimulation is more effective than sham
electrical simulation. To date there are too few studies to evaluate effects of
PFM exercise with or without biofeedback, and of toilet training for women with
UUI. CONCLUSION: Although almost all studies included reported positive results
in favour of physical therapies for the treatment of UUI, more research of high
methodological quality is required to evaluate the effects of each method in the
range of physical therapies.
PMID- 10671879
TI - The use of cadaveric fascia lata in the treatment of stress urinary incontinence
in women.
PMID- 10671880
TI - The immunohistochemical assessment of occult regional lymph node metastases in
patients with T3pN0M0 prostate cancer before definitive radiotherapy.
AB - OBJECTIVE: To detect occult regional lymph node metastases in patients with
T3pN0M0 prostate cancer not recognized by routine haematoxylin and eosin
staining, and to evaluate the clinical relevance of this finding. PATIENTS AND
METHODS: Formalin-fixed and paraffin-embedded pelvic lymph nodes (1118) from 92
patients were evaluated by immunohistochemistry using antibodies for prostate
specific antigen (PSA) and pancytokeratin (AE1/AE3). Of the tumours, 14% were
well, 69% moderately and 17% poorly differentiated. The extent of tumour was
categorized as T3pN0M0 in all patients, who were referred for definitive
radiotherapy after pelvic staging lymphadenectomy. The median (range) serum PSA
value before treatment was 18.5 (0.4-342) microg/L. After radiotherapy, the
patients were followed by assessing biochemical progression, pelvic recurrence
and/or development of distant metastases. The median (range) observation time for
all patients was 61 (16-136) months. RESULTS: Occult lymph node metastases were
detected in four (4.4%) of the 92 patients. Patients with or without occult
metastases had similar serum PSA levels and histological grades. None of the four
patients with occult metastases progressed, compared with 37 of the 88 (42%) with
no such metastases. CONCLUSION: Using immunohistochemistry the detection rate of
occult lymph node metastases in patients with T3pN0M0 prostate cancer is low. The
occurrence of such metastases is probably unrelated to the serum PSA value before
treatment. The short-term outcome of patients subsequently treated with
definitive radiotherapy does not seem to be associated with the finding of occult
lymph node metastases, but long-term follow-up is needed. So far, the results do
not justify the search for occult lymph node metastases as a routine procedure in
these patients
PMID- 10671881
TI - Elevated serum vascular endothelial growth factor in patients with hormone
escaped prostate cancer.
AB - OBJECTIVE: To investigate the role of serum vascular endothelial growth factor
(VEGF) in the assessment of patients with prostate cancer. Patients, subjects and
methods Serum from 78 men was assayed for VEGF using a commercially available
enzyme-linked immunosorbent assay kit. Forty-eight patients had a
histopathological diagnosis of prostate cancer (16 local disease, 32 metastatic),
nine had benign prostatic hyperplasia (BPH) and 21 were healthy controls.
RESULTS: The mean serum VEGF level was significantly higher in patients with
hormone-escaped prostate cancer than in all other groups (P = 0. 02). There
were no significant differences in serum VEGF levels among the other groups. In
18 patients with serial measurements there was no significant difference in serum
VEGF level during either response to or escape from hormonal therapy.
CONCLUSIONS: The significantly higher serum VEGF level in patients with hormone
escaped prostate cancer suggests a role in the pathogenesis of advanced disease.
However, the lack of significant differences among the other groups and the
failure to indicate either response to or escape from hormonal therapy suggests
that serum VEGF in this setting is of limited use.
PMID- 10671882
TI - Cryoablation for clinically localized prostate cancer using an argon-based
system: complication rates and biochemical recurrence.
AB - OBJECTIVE: To determine the complication rates and biochemical recurrence after
cryoablation of the prostate, using an argon gas-based system, in patients with
localized prostate cancer. PATIENTS AND METHODS: Between October 1997 and June
1999, 35 patients underwent cryoablation of the prostate (19 after radiation
therapy failure and 16 as a primary treatment for localized prostate cancer). All
patients had biopsy-confirmed prostate cancer with no seminal vesicle invasion,
negative bone scans and a negative lymph node dissection. Patients received 3
months of combined hormonal therapy before cryosurgery. One surgeon performed all
the procedures. Biochemical recurrence was defined by an increase in prostate
specific antigen (PSA) of >/= 0.2 ng/mL above the PSA nadir. RESULTS: The
complications were rectal pain (26%), urinary infection (3%), scrotal oedema
(12%), haematuria (6%) and incontinence (6%). Complication rates were higher in
those patients who failed after radiation therapy than in those who did not
receive radiation (incontinence 11% vs 0%, rectal pain 37% vs 12%) but the
difference was not statistically significant. Twenty-two patients (63%) had an
undetectable serum PSA nadir (< 0.1 ng/mL) after cryotherapy and 30 (84%)
patients had a PSA value of < 1.0 ng/mL. After a mean follow-up of 8.3 months
(range 0.2-18), nine patients had biochemical recurrence. The biochemical
recurrence-free survival (BRFS) was 70% at 9 months. Patients who had an
undetectable PSA nadir had a statistically higher BRSF at 9 months than did
patients who had a detectable PSA nadir (89% vs 55%, respectively, P = 0.03).
Similarly, patients with a preoperative serum PSA level of < 10 ng/mL had a
statistically higher BRFS than patients who had a PSA level of > 10 ng/mL (86% vs
42% at 9 months, P < 0.001). CONCLUSION: A PSA level before cryotherapy of < 10
ng/mL and an undetectable PSA nadir after cryotherapy were associated with the
highest BRFS. Cryoablation of the prostate, with low morbidity, seems to be a
viable option in managing patients by salvage therapy after radiation therapy and
for the primary treatment of clinically localized prostate cancer.
PMID- 10671883
TI - Radical retropubic prostatectomy: time trends, morbidity and mortality in Japan.
AB - OBJECTIVES: To assess the time trends, morbidity and mortality of contemporary
anatomical radical retropubic prostatectomy (RRP) in a multi-institutional study
in Japan, where RRP has become more popular in the last decade. PATIENTS AND
METHODS: Between January 1991 and August 1998, 638 patients underwent RRP at
seven urological centres in Japan. Major complications (within 30 days of
surgery) and the 30-day mortality were reviewed retrospectively. Of the patients,
12.9% were < 60 years old, 56.3% were 60-69 years old and 30.9% were >/= 70 years
old (median age 67). Results The number of RRPs increased markedly, by more than
sevenfold, from 1991-92 to 1996-97, mainly because there were more patients
undergoing RRP in their sixth decade. The contribution of T1c disease increased
in absolute and relative terms, from 13.9% in 1991-92 to 37.9% in 1997-98. Over
time, the mean blood loss and the allogeneic transfusion rate decreased steadily.
There was a trend toward more favourable outcomes for pathological variables (an
increased percentage of organ-confined disease, decreased margin positivity and a
decreased incidence of positive lymph node metastasis). The most common
complications were wound-related (7.5%), or anastomotic leakage (4.1%). Major
cardiopulmonary complications occurred in only two patients (0.31%, both
pulmonary embolisms). One patient died from cerebral haemorrhage within 30 days
of surgery, giving a mortality rate of 0.16%. CONCLUSION: s This study indicates
a trend towards selecting patients most likely to benefit from RRP. Although the
procedure is technically demanding, it can have an acceptably low rate of early
complications, little mortality and need for allogeneic transfusion. The
assessment of morbidity suggests a lower incidence of catastrophic thrombo
embolic and cardiac complications in Japanese patients than in Western men. The
present data may be useful in decision-analysis models evaluating the role of
therapy for Asian men with early-stage prostate cancer.
PMID- 10671884
TI - Genital self-mutilation: there is no method in this madness.
PMID- 10671885
TI - The histological extent of the local spread of carcinoma of the penis and its
therapeutic implications.
AB - OBJECTIVE: To explore the possibility of reducing the margin of clearance at
surgery for carcinoma of the penis without causing an increase in the incidence
of local tumour recurrence, so that the functional and cosmetic compromise
associated with penectomy might be minimized. PATIENTS AND METHODS: Sixty-four
patients underwent partial or total penectomy based on the extent of tumour. The
specimens were evaluated histologically for grade and for proximal microscopic
extensions beyond the grossly visible tumour margin, by examining serial proximal
5 mm sections. The histological grade of the lesion was correlated with its
clinical site, morphology and proximal microscopic spread. Differences were
assessed using the chi-squared test. RESULTS: Of 64 tumours, 31% were grade 1,
50% grade 2 and the remaining 19% grade 3. Higher grade lesions were more likely
to involve the penile shaft. The maximum proximal histological extent was 5 mm
for grades 1 and 2, and 10 mm for grade 3 tumours; there was no discontinuous
spread. CONCLUSIONS: Histological grading is mandatory in the management of
carcinoma of the penis. A 10-mm clearance is adequate for grade 1 and 2 lesions,
and 15 mm for grade 3 tumours. This approach would qualify more patients for
partial rather than total amputation; the residual length of the penis would then
be cosmetically and functionally more acceptable.
PMID- 10671886
TI - Testicular adenomatoid tumours: clinical and ultrasonographic characteristics.
AB - OBJECTIVE: To determine if benign testicular tumours can be identified clinically
and ultrasonographically before surgery. PATIENTS AND METHODS: The clinical and
ultrasonographic findings of six patients with testicular adenomatoid tumours and
16 with testicular germ cell tumours were assessed retrospectively and compared.
RESULTS: All adenomatoid tumours were characterized on physical examination by a
well-defined, painful and unfixed nodule, contrasting with the painless and ill
defined malignant lesions. On ultrasonography, of the six adenomatoid tumours,
two appeared hypoechoic, one hyperechoic, two isoechoic and one was normal,
whereas none of the 16 tumours appeared normal or isoechoic. CONCLUSIONS: While
isoechogenicity was not apparent in the group of testicular malignancies, the two
groups had hypo- and hyperechoic patterns. Small, superficial, painful and
unfixed testicular tumours that appear isoechoic on ultrasonography should be
biopsied through an inguinal approach, with frozen sections assessed, instead of
the patients undergoing immediate radical orchidectomy.
PMID- 10671887
TI - Low-grade left varicocele in patients over 30 years old:the effect of spermatic
vein ligation on fertility.
AB - OBJECTIVES: To evaluate the effect of spermatic vein ligation in patients over 30
years old and with low-grade left varicocele, and thus help to establish whether
such patients might benefit from surgery. PATIENTS AND METHODS: A randomized
study was conducted on 68 infertile patients (30-38 years old) with evidence of
sperm abnormalities and who had low-grade varicocele (grade I according to
Hirsch), comparing left spermatic vein ligation with no treatment. The outcome
was assessed by standard sperm analysis and eventual paternity. RESULTS: There
was no improvement in sperm quality in either of the groups one year after
surgery, and no significant difference in paternity. CONCLUSIONS: Left spermatic
vein ligation for low-grade varicocele in patients more than 30 years old cannot
be recommended.
PMID- 10671888
TI - The role of the renal resistive index ratio in diagnosing obstruction and in the
follow-up of children with unilateral hydronephrosis.
AB - OBJECTIVE: To assess the role of the renal resistive index ratio (RIR) in
discriminating equivocal upper urinary tract dilatation in children, and thus in
establishing the need for surgery, in comparison with traditional diagnostic
tools. PATIENTS AND METHODS: The study comprised 40 children with unilateral
hydronephrosis unrelated to vesico-ureteric reflux, posterior urethral valves,
megaureter or a duplex system. In all patients one or more of the following
'indices of obstruction' were positive; an anteroposterior renal pelvic diameter
of >20 mm, a half-time diuretic 'washout' (T/2) of > 20 min, a separate renal
function of < 40%, and symptoms of obstruction (pain, sepsis). All these
variables were measured on admission and after a mean (range) follow-up of 9 (2
24) months. After this period, all patients who were symptomatic or with two or
more of the variables above the normal range were considered as obstructed and
underwent a dismembered pyeloplasty. The variables were then re-assessed 6 months
after surgery. The RIR was evaluated using duplex Doppler ultrasonography with a
3.5-5 MHz transducer, by the same operator. Differences between obstructive and
unobstructive unilateral hydronephrosis were estimated from the mean values of
the variables assessed and Student's t-test used to determine significant
differences. The correlation between the T/2 and RIR before and after surgery was
also evaluated. RESULTS: During follow-up the RIR was abnormal in 27 of 30
patients with hydronephrosis who were considered to be 'obstructed'. Twenty-three
of these patients, selected for surgery, had a positive diuretic renogram; 11 had
loss of differential renal function and 16 had recurrent clinical symptoms. There
were significant differences in the mean RIR and T/2 between obstructed and
unobstructed patients. Six months after dismembered pyeloplasty, the RIR returned
to normal in all patients except three in whom it was previously > 1.1. The
diuretic renogram, if initially showing pathology, always became normal. The RIR
did not change in patients with an unchanged and severe loss of differential
renal function before and after surgery. CONCLUSIONS: In this study the RIR was a
good index of obstruction in children with unilateral hydronephrosis and it
correlated well with the results of diuretic renography. The specificity of the
RIR was reduced whenever there was severe renal damage.
PMID- 10671889
TI - The efficacy and parenchymal consequences of extracorporeal shock wave
lithotripsy in infants.
AB - OBJECTIVES: To determine the efficacy of extracorporeal shock-wave lithotripsy
(ESWL) in young children and to evaluate, using renal scintigraphy, any possible
adverse effects on renal parenchyma. PATIENTS AND METHODS: From January 1991 to
October 1998, 19 infants (aged 5-24 months) underwent ESWL for kidney
urolithiasis using a Sonolith 3000 (14 kV, Technomed Corp, Lyon, France) or a
Nova (14-20 kV, Direx Medical Systems, Paris, France) lithotripter. The treatment
and its effects were evaluated using a physical examination, conventional imaging
(plain abdominal X-ray and ultrasonography) and renal scintigraphy 24 h before
ESWL and again at least 6 months after the last session of treatment. RESULTS:
Ten children were rendered stone-free by ESWL after one session and 18 after two
sessions. At the follow-up (8 months to 8 years, mean 36 months) no hypertension
was recorded and no acquired parenchymal damage was detected with conventional
imaging. No scars or significant variation of differential function attributable
to ESWL were identified on renal scintigraphy. CONCLUSION: ESWL is clearly
effective for treating infant urolithiasis. There were no renal parenchymal
lesions associated with ESWL, even in previously damaged kidneys or after the
treatment of staghorn calculi. A long-term follow-up (assessing blood pressure)
is mandatory and renal scintigraphy before and 6 months after ESWL in infants is
recommended to confirm these results in a larger series.
PMID- 10671890
TI - Schistosoma haematobium infection in children in Britain.
AB - OBJECTIVE: To highlight the existence of Schistosoma haematobium in certain
ethnic minority groups in Britain and in English citizens who have recently
visited Africa and the Middle East, so that general practitioners and paediatric
nephrologists/urologists are aware of its occurrence and consider it among the
differential diagnoses in children presenting with haematuria. PATIENTS AND
METHODS: Over a 2-year period, six consecutive boys (mean age 13.5 years, range 8
15) presented with haematuria and were subsequently diagnosed to be infected with
S. haematobium. All patients were from Africa and had recently visited their
native country. There had all reported paddling in freshwater lakes and streams.
RESULTS: Dysuria and haematuria was noted 2-3 months after the infection.
Terminal urine samples taken after exercise at midday were positive for S.
haematobium ova. Praziquantel anti-schistosomal chemotherapy was effective in
treating the infection. CONCLUSION: S. haematobium infection is treatable in the
early stages and the changes are reversible before the development of fibrotic
lesions, which may result in anatomical obstruction. A terminal urine sample
taken at midday after exercise was diagnostic in showing Schistosoma ova in all
cases. This infection must be considered in the differential diagnoses of
haematuria in some ethnic minority British citizens and in those Britons who have
visited Africa or the Middle East in the recent past.
PMID- 10671891
TI - In vitro contractile responses of detrusor to carbachol and neurokinin A, in
children with recurrent urinary tract infection or day wetting.
AB - OBJECTIVE: To investigate whether a history of recurrent urinary tract infection
(UTI) and/or the presence of day-wetting/urge symptoms might influence the
contractile responses to the cholinergic agonist carbachol or to the sensory
neuropeptide neurokinin A (NKA) in the urinary bladder in children. PATIENTS AND
METHODS: Small detrusor strips were taken from the margin of the cystotomy
incision of the bladder dome during surgery to correct vesico-ureteric reflux
(VUR) in 62 children (aged 4 months to 12 years) or for unrelated bladder
conditions in five controls (aged 3 months to 13 years). Concentration-response
curves to carbachol and NKA were constructed using organ-bath techniques, and
results compared for age, sex, weight of the detrusor strip, UTI history or day
wetting syndrome. RESULTS: The contractile responses to NKA were no different for
any of the features investigated. The contractile response to carbachol and NKA
in detrusor from control and VUR patients was not significantly different. The
children with a history of UTI were significantly older than those without. The
contractility in response to carbachol was greater in older girls (aged 4-12
years) than younger girls (< 4 years) and than in all boys (< 4 years and 4-12
years; ANOVA P = 0.013). The mean (SEM) maximum contractile response to carbachol
in the group of 20 young children (4-30 months) with previous UTI was 3.0 (0.3)
g, whereas the maximum response in the age-matched group of 11 without UTI was
1.8 (0.3) g (P = 0.046). There were no significant differences in maximum
responses between those with day-wetting and those without (aged > 4 years),
although there was a significant difference in pD2 value, at 6.19 (0.13) and 5.58
(0.14), respectively (P = 0.018). CONCLUSION: Carbachol produced a larger
contractile response in detrusor from children with a history of UTI than from
those without, indicating possible alterations in muscarinic receptor
characteristics. An increased sensitivity to muscarinic stimulation in day
wetting children was also suggested, whereas NKA is unlikely to be involved in
any of these pathophysiological conditions.
PMID- 10671892
TI - Apoptosis in the erectile tissues of diabetic and healthy rats.
AB - OBJECTIVE: To compare the frequency of apoptosis in the erectile tissue of
chronic diabetic and healthy rats. MATERIALS AND METHODS: Fourteen chronic
diabetic and 10 healthy Sprague-Dawley rats were killed, their penises harvested
and stored at -70 degrees C until staining and flow cytometric analysis for
apoptosis. A cell suspension was obtained from the penile tissue by scraping the
inside of the cavernosum with a scalpel and filtering through a mesh. Samples of
the cell suspension (0.5 x 106 cells) were stained with Annexin V (an indicator
of apoptosis) and propidium iodide (PI, which stains dead cells), incubated for
15 min at room temperature and analysed by flow cytometry. The DNA content was
also analysed in each sample. RESULTS: In normal erectile tissue, a mean of 6.2%
of cells were stained with Annexin V, while only 2.7% were stained with PI; DNA
content analyses showed 7.5% were hypodiploid cells. In diabetic rats 19.5% of
cells were stained with Annexin V and 5.2% with PI; 22.9% of cells were
hypodiploid. CONCLUSION: The ratio of apoptotic cells in the erectile tissues of
diabetic rats was significantly greater than in normal rats. The high rate of
apoptosis in diabetic rats may play a role in the pathophysiology of erectile
dysfunction.
PMID- 10671893
TI - Do experimentally induced ipsilateral testicular torsion, vas deferens
obstruction, intra-abdominal testis or venous obstruction damage the
contralateral testis through a common mechanism?
AB - OBJECTIVE: To evaluate if various conditions affecting the ipsilateral testis
which also damage the contralateral testis share a common pathway for their
effects. MATERIALS AND METHODS: The study comprised five groups of 10 adult rats
which underwent surgery to produce (on their left sides); group 1, a sham
operation (control); group 2, testicular torsion; group 3, vas deferens
obstruction; group 4, an intra-abdominal testis; and group 5, venous obstruction.
The ipsilateral and contralateral testes were harvested 4 weeks after surgery.
The relative proportions of haploid cells, the mean seminiferous tubular diameter
(MSTD), mean testicular biopsy scores (MTBS), and lactate and hypoxanthine levels
were determined and compared. RESULTS: The proportions of haploid cells in the
ipsilateral and the contralateral testes of groups 2-5 were significantly lower
than those of the corresponding testes of the control group. The MSTD and MTBS of
the ipsilateral testes in groups 2-5 were also significantly lower than the
ipsilateral testes of controls and the contralateral testes within the same
groups. While the MSTD and MTBS of the contralateral testes of groups 1 and 5
were not significantly different, those of the contralateral testes of groups 2-4
were significantly less than that of group 1. The lactic acid and hypoxanthine
levels of the ipsilateral and contralateral testes were significantly increased
in groups 2 and 3. While only the hypoxanthine level of group 5 increased
significantly, both variables were not significantly different between the
ipsilateral testes of groups 1 and 4. CONCLUSIONS: These four treatments damaged
both the ipsilateral and contralateral testes. As the lactic acid and
hypoxanthine levels within the contralateral testis were greater than in the
controls, testicular torsion and vas deferens obstruction seem to share a common
pathway (which may be a reflex decrease in contralateral testicular blood flow)
for their effects on the contralateral testis.
PMID- 10671894
TI - Increased intra-abdominal pressure alters the contractile properties of rabbit
bladder.
AB - OBJECTIVE: To evaluate the effects of increased intra-abdominal pressure (IAP) on
the contractility of the rabbit bladder, as the dynamics of the bladder may be
impaired in conditions associated with a high IAP, e.g. constipation and
pregnancy. Material and methods The study comprised 22 adult male New Zealand
rabbits; six served as the control group, eight had an IAP of 7 cmH2O imposed for
10 days by instilling air into the abdominal cavity and this IAP was maintained
for 60 days in a further eight rabbits. After treatment, the rabbits were killed,
and the bladders removed and cut into 3 x 12 mm strips. The contractile activity
of the muscle strips was then recorded isometrically. Electrical field
stimulation (EFS) was applied using a pair of platinum ring electrodes in trains
of 3 s duration every 100 s (1 ms, 100 V, 2-100 Hz). Contractile responses to
carbachol and isotonic KCl were also evaluated. RESULTS: EFS induced a frequency
dependent increase in contractile activity in all bladder strips. Ten days of
high IAP resulted in an increased responsiveness to EFS, but high IAP for 60 days
reduced the EFS-induced responses to the control levels. Carbachol (10-9-10-3
mol/L) elicited concentration-dependent contractions in all groups. From the
concentration-response curves of carbachol, the log EC50 values (the
concentration producing half the maximum effect) of the control and 60-day
treated animals were comparable, at -6.24 (0.05) and -6.25 (0.04), respectively.
However, the log EC50 of the 10 day-treated group was -4.97 (0.08) and
significantly (P < 0.01) lower than that of both groups. Isotonic KCl produced
contractions in all preparations; these contractions in the control and 60-day
treated animals were similar, while the 10 day-treated group had significantly (P
< 0.05) higher contraction amplitudes. CONCLUSION: Increased IAP alters the
contractile properties of the bladder and its responsiveness to carbachol and
KCl. As the intravesical pressure closely reflects the IAP, both should be
increased in the present experimental design.
PMID- 10671895
TI - Continence and some properties of the urethral striated muscle of male
greyhounds.
AB - OBJECTIVE: To determine the properties of the striated muscle of the greyhound
(dog) urethra and to consider its role in maintaining continence. Materials and
methods The thickness of the muscle layers and the muscle types were determined
by examining sections stained with haematoxylin and eosin or Masson's trichrome.
These factors were correlated with the mechanical and electrical responses of
muscle strips to nerve stimulation, and compared with muscle from other breeds of
dog and other parts of the animal. RESULTS: The striated muscle formed
approximately 70% of the membranous urethra and was predominantly (68%) type IIa
muscle (i.e. fast but fatigue-resistant). The mean resting membrane potential was
-74 mV; nerve stimulation produced an action potential with a mean amplitude of
97 mV and contraction lasting about 200 ms. All responses were abolished by D
tubocurarine. The contractions were well maintained with continuous or
intermittent stimulation. The properties were intermediate between those of the
anconeus (slow) and the extensor carpi radialis (fast) muscles. CONCLUSIONS: The
distribution, fibre type and contractile characteristics would enable the
striated urethral muscle to maintain tension for continence at rest and provide
additional continence during sprints.
PMID- 10671896
TI - The effect of pregnancy and delivery on the function and ultrastructure of the
rat bladder and urethra.
AB - OBJECTIVE: To examine the effect of pregnancy and delivery on the function and
ultrastructure of the bladder and urethra in rats. Material and methods The study
comprised six virgin and 18 pregnant rats; both groups underwent cystometry (at
the 19th day of gestation, and 2 days and 6 weeks after parturition). Tissues
from the bladder and urethra were collected for electron microscopy, western
blotting and immunostaining for caveolin-1 and caveolin-3. RESULTS: The bladder
capacity was greater and the modified leak-point pressures lower in pregnant and
2-day postpartum rats than in virgin and 6-week postpartum rats. The residual
volume was significantly higher in the pregnant group. Electron microscopy showed
more sarcolemmal caveolae in the smooth muscle cells of both the bladder and
urethra of virgin rats than in the other groups. Lipid droplets and
subsarcolemmal mitochondria accumulated in pregnant and 2-day postpartum rats.
Caveolin-1 protein was detected in the cytoplasmic membrane of urethra and
bladder smooth muscle cells. Caveolin-3 was detected in the membrane of striated
muscle in the intrinsic sphincter. Western blotting showed increased caveolin-1
protein expression in the bladder and urethra of 2-day postpartum rats; in
contrast, levels of caveolin-1 were lower in pregnant rats than in virgin and 6
week postpartum rats. CONCLUSION: s During pregnancy there was a significant
decrease in sarcolemmal caveolae and caveolin-1 in the smooth muscle cells of the
rat bladder and urethra. The changes in caveolae and the membrane protein
caveolin may play a role in the functional changes associated with pregnancy and
after delivery.
PMID- 10671897
TI - Homologous bladder augmentation in dog with the bladder acellular matrix graft.
AB - OBJECTIVE: To determine the functional potential and antigenicity of the
homologous bladder acellular matrix graft (BAMG) in a dog model. MATERIALS AND
METHODS: Seven mongrel dogs underwent partial cystectomy (20-50%) and grafting
with an equal-sized BAMG; two control animals underwent partial cystectomy (40%)
only. The dogs were killed after 30 (one), 120 (one) and 210 days (five dogs).
Blood samples were obtained before and at 1, 2, 4, 7, 14, 30, 90 and 210 days
after surgery. The dogs underwent cystography, intravenous pyelography and
ultrasonography before and after surgery, and on the day they were killed, with
cystoscopy carried out just before death. The grafted tissue was assessed using
routine and immunohistochemical techniques. RESULTS: All the dogs survived
surgery; a complete blood cell count, chemical panel and white blood cell count
showed no significant difference between the experimental and control animals.
Cystography, cystoscopy and ultrasonography revealed no pathological changes in
the upper urinary tract. After 7 months, the mean bladder capacity in the
augmented dogs was significantly higher (P = 0.035) than in the controls (264 vs
172 mL). Histological evaluation showed an invasion of all bladder wall
components during the first month; at 7 months, the morphological examination
showed essentially complete regeneration. CONCLUSION: In this dog model, the
potential of the BAMG as a bladder augmentation graft was confirmed, having
minimal antigenicity with maximal acceptance. The reconstructed bladder matched
the morphological and functional properties of the normal bladder.
PMID- 10671898
TI - The treatment of chronic radiation proctitis with hyperbaric oxygen in patients
with prostate cancer.
PMID- 10671899
TI - Vesicovaginal fistula associated with a vaginal foreign body.
PMID- 10671900
TI - Numb-chin syndrome: an unusual presentation of metastatic prostate cancer.
PMID- 10671901
TI - Drug trials in children: problems and the way forward.
PMID- 10671902
TI - The effect of staggered dosing of sucralfate on oral bioavailability of
sparfloxacin.
AB - AIMS: To investigate the effect of sucralfate on sparfloxacin absorption when
administered concurrently or at strategically spaced dosing times designed to
avoid the potential interaction. METHODS: The study was a four-way crossover
design where eight healthy Japanese volunteers were randomized to one of four
treatment sequences at entry. A 300 mg dose of sparfloxacin was administered
alone for treatment A (control). Treatments B, C and D included sucralfate 1.5 g
every 12 h for five doses. For treatment B, the fifth dose of sucralfate was
administered concurrently with sparfloxacin 300 mg. For treatment C, 300 mg
sparfloxacin was given 2 h prior to the fifth dose of sucralfate. Treatment D
consisted of sparfloxacin 300 mg given 4 h prior to the fifth dose of sucralfate.
Blood and urine samples were collected at predetermined time intervals for 72 h.
Sparfloxacin concentrations in plasma and urine and the concentrations of
sparfloxacin metabolite in urine were determined by high performance liquid
chromatography assays. RESULTS: Sucralfate administrated concurrently with
sparfloxacin decreased the mean AUC(0,infinity) of sparfloxacin 2-fold (P<0.001)
and the mean Cmax 2.1-fold (P<0.001) compared with sparfloxacin alone. When
sucralfate was administrated 2 h after sparfloxacin, the mean AUC(0,infinity) was
decreased 1.5-fold (P<0.01) and the mean Cmax 1.4-fold (P<0.01). Sucralfate did
not alter the extent of absorption of sparfloxacin when it was given 4 h after
the administration of sparfloxacin. The relative bioavailabilities for treatments
B, C and D were 0.50 (95% CI: 0.35-0.65), 0.64 (95% CI: 0. 51-0.77), and 0.92
(95% CI: 0.81-1.03), respectively, relative to sparfloxacin alone. The mean
percentage of the sparfloxacin dose recovered in urine was significantly lower
after sparfloxacin was administered with sucralfate than after sparfloxacin was
administered alone or 2 h before the sucralfate dose (P<0.001). Treatments B, C
and D were demonstrated to be equivalent to treatment A in the rate of
absorption. The tmax, CLr and t1/2 were not significantly affected by sucralfate.
The metabolism of sparfloxacin was not altered in the presence of sucralfate.
CONCLUSIONS: Oral administration of sucralfate with sparfloxacin or 2 h after
sparfloxacin, decreased the extent of sparfloxacin absorption. When both drugs
are to be administered together, sucralfate should be administered 4 h after
sparfloxacin, allowing thus sufficient time for sparfloxacin absorption prior to
the sucralfate dose and thereby minimizing the chance of a significant
interaction.
PMID- 10671903
TI - Non-linear pharmacokinetics of MDMA ('ecstasy') in humans.
AB - AIMS: 3,4-Methylenedioxymethamphetamine (MDMA, commonly called ecstasy) is a
synthetic compound increasingly popular as a recreational drug. Little is known
about its pharmacology, including its metabolism and pharmacokinetics, in humans
in controlled settings. A clinical trial was designed for the evaluation of MDMA
pharmacological effects and pharmacokinetics in healthy volunteers. METHODS: A
total of 14 subjects were included. In the pilot phase six received MDMA at 50
(n=2), 100 (n=2), and 150 mg (n=2). In the second phase eight received MDMA at
both 75 and 125 mg (n=8). Subjects were phenotyped for CYP2D6 activity and were
classified as extensive metabolizers for substrates, such as MDMA, whose hepatic
metabolism is regulated by this enzyme. Plasma and urine samples were collected
throughout the study for the evaluation of MDMA pharmacokinetics. Body fluids
were analysed for the determination of MDMA and its main metabolites 3,4
methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxy-methamphetamine (HMMA) and 4
hydroxy-3-methoxy-amphetamine (HMA). RESULTS: As the dose of MDMA administered
was increased, volunteers showed rises in MDMA concentrations that did not follow
the same proportionality which could be indicative of nonlinearity. In the full
range of doses tested the constant recovery of HMMA in the urine combined with
the increasing MDMA recovery seems to point towards a saturation or an inhibition
of MDMA metabolism (the demethylenation step). These observations are further
supported by the fact that urinary clearance was rather constant while nonrenal
clearance was dose dependent. CONCLUSIONS: It has previously been postulated that
individuals genetically deficient for the hepatic enzyme CYP2D6 (about 10% of the
Caucasian people) were at risk of developing acute toxicity at moderate doses of
MDMA because the drug would accumulate in the body instead of being metabolized
and inactivated. The lack of linearity of MDMA pharmacokinetics (in a window of
doses compatible with its recreational use) is a more general phenomenon as it
concerns the whole population independent of their CYP2D6 genotype. It implies
that relatively small increases in the dose of MDMA ingested are translated to
disproportionate rises in MDMA plasma concentrations and hence subjects are more
prone to develop acute toxicity.
PMID- 10671904
TI - Effects of sibutramine alone and with alcohol on cognitive function in healthy
volunteers.
AB - AIMS: To investigate the effects of sibutramine in combination with alcohol in a
double-blind, randomised, placebo-controlled, four-way crossover study in 20
healthy volunteers. METHODS: On each study day each volunteer received either:
sibutramine 20 mg+0.5 g kg-1 alcohol; sibutramine 20 mg+placebo alcohol; placebo
capsules+0.5 g kg-1 alcohol; or placebo capsules+placebo alcohol. Alcohol was
administered 2 h following ingestion of the study capsules. During each study
day, assessments of cognitive performance were made prior to dosing, and at 3,
4.5, 6 and 10 h post dosing. Blood alcohol concentration was estimated using a
breath alcometer immediately prior to each cognitive performance test session.
Each study day was followed by a minimum 7 day washout period. RESULTS: Alcohol
was found to produce statistically significant impairments in tests of attention
(maximum impairment to speed of digit vigilance=49 ms) and episodic memory
(maximum impairment to speed of word recognition=74 ms). Alcohol also increased
body sway (maximum increase 17.4 units) and lowered self rated alertness (maximum
decrease 13.6 mm). These effects were produced by an inferred blood alcohol level
of 53.2 mg dl-1. Sibutramine was not found to potentiate any of the effects of
alcohol. There was a small, yet statistically significant, interaction effect
observed on the sensitivity index of the picture recognition task. In this test,
the combined effects of sibutramine and alcohol were smaller than the impairments
produced by alcohol alone. Sibutramine, when dosed alone, was associated with
improved performance on several tasks. Sibutramine improved attention (mean speed
of digit vigilance improved by 21 ms), picture recognition speed (improvement at
3=81) and motor control (tracking error at 3 h reduced by 1.58 mm). Also
sibutramine improved postural stability (reducing body sway at 3 h by 14.2
units). Adverse events reported were unremarkable and consistent with the known
pharmacology of sibutramine and alcohol. CONCLUSIONS: There was little evidence
of a clinically relevant interaction of sibutramine with the impairment of
cognitive function produced by alcohol in healthy volunteers. The single
statistically significant interaction indicated a reduction, rather than a
worsening, of alcohol-induced impairment when sibutramine is taken concomitantly.
Sibutramine when administered alone is associated with improved performance on
several tasks.
PMID- 10671905
TI - Pharmacodynamics of milnacipran in young and elderly volunteers.
AB - AIMS: To investigate the pharmacodynamics of milnacipran in healthy young and
elderly volunteers. METHODS: Randomized double-blind crossover designs were
employed and a standardized psychometric battery was administered pre and post
dose for both studies. In the first study 10 healthy young volunteers received
milnacipran 12.5 mg, 25 mg, 50 mg, 100 mg as a single dose or matched placebo.
The test battery was administered at baseline and at 1, 2, 4 and 6 h post dose.
The second study compared the effects of milnacipran 75 mg (50 mg+25 mg) per day,
amitriptyline 50 mg (25 mg+25 mg) per day and placebo for 3 days' dosing in
healthy volunteers aged over 65 years. The test battery was administered at
baseline and at 2, 10 and 24 h post dose. The psychometric battery included
critical flicker fusion (CFF), choice reaction time (CRT), compensatory tracking
(CTT) and tests of short-term memory (STM), subjective sedation (LARS) and
subjective sleep (LSEQ). RESULTS: Milnacipran produced no significant dose
related effects in the young volunteers. For the elderly, milnacipran
significantly (P<0.05) raised CFF scores compared with placebo but had no
significant effects on any of the other measures used. Amitriptyline, in
contrast, significantly (P<0. 05) lowered CFF threshold, lengthened CRT and
increased error on the CTT. On the subjective variables, LARS and LSEQ,
amitriptyline increased ratings both of sedation and of difficulty in waking from
sleep. CONCLUSIONS: The results showed that milnacipran at single doses of up to
100 mg in healthy young volunteers is free from disruptive effects on cognitive
function and psychomotor performance. In addition, milnacipran 75 mg (50+25 mg)
appears to be free of negative effects on cognitive function in elderly
volunteers, where it seemingly improves performance on CFF. In contrast, the
tricyclic antidepressant amitriptyline, used here as a positive internal control,
significantly impaired performance in the elderly on the majority of psychometric
measures used in this study. This finding not only validated the sensitivity of
this current test battery but also indicates the potential behavioural toxicity
of amitriptyline in clinical use in the elderly.
PMID- 10671906
TI - Comparison of the vasoconstrictor effects of the selective 5-HT1D-receptor
agonist L-775,606 with the mixed 5-HT1B/1D-receptor agonist sumatriptan and 5-HT
in human isolated coronary artery.
AB - AIMS: Vasoconstriction in human coronary artery can be mediated via activation of
both 5-HT2 and 5-HT1B-receptors. Coronary vasoconstriction is a rare, but
potential adverse effect of the antimigraine drug sumatriptan. In order to
investigate the receptor population involved we compared the vasoconstrictor
effects of sumatriptan (a mixed 5-HT1B/1D-receptor agonist) with those of L-775,
606 (a selective 5-HT1D-receptor agonist) and 5-HT (the endogenous ligand) in
human isolated coronary arteries. METHODS: Coronary arteries were obtained from
human hearts removed prior to transplant surgery. Several endothelium denuded
ring segments (4 mm in length) were obtained from each artery and mounted for
isometric tension recording. Each segment was first exposed to 45 mm KCl and then
to 5-HT (1 nm-100 microm ). Concentration-effect curves to L-775,606 (1-(3-(5
(1,2, 4-triazol-4-yl)-1H-indol-3-yl)propyl)-4-(2-(3-fluorophenyl)ethyl)p ipe
razine) and sumatriptan were then performed in a consecutive and random manner.
The response to repeated application of 5-HT was obtained in separate segments.
RESULTS: Twenty-five segments from seven different coronary arteries were
studied. Concentration-effect curves were fitted to the data using nonlinear
regression analysis. The maximum contraction for L-775,606 was significantly less
than that for sumatriptan with Emax values (% relative to 45 mm KCl=100%) of
30.1+/-4.22 and 41.5+/-2.7, respectively. L-775,606 was significantly (30-fold)
less potent than sumatriptan in causing contraction compared with sumatriptan
(EC50 values were 6.0 microm and 0.2 microm, respectively). For comparison the
Emax value for 5-HT was 77.2% and the EC50 value was 0.2 microm. CONCLUSIONS: The
selective 5-HT1D-receptor agonist L-775,606 has less propensity towards
vasoconstriction in human isolated coronary artery (endothelium-denuded) than was
mixed 5-HT1B/1D-receptor agonist sumatriptan. The contractions produced were at
concentrations where L-775,606 would be expected to occupy 5-HT1B-receptors.
PMID- 10671907
TI - Pharmacokinetics and pharmacodynamics of R- and S-gallopamil during multiple
dosing.
AB - AIMS: Using a stable isotope technique we investigated the pharmacokinetics and
pharmacodynamics of gallopamil after administration of 50 mg pseudoracemic
gallopamil every 12 h for 7 doses (72 h). METHODS: Six male healthy volunteers
were studied. After the seventh dose the pharmacokinetics and pharmacodynamics
were assessed. Serum levels of gallopamil were measured by gas
chromatography/mass spectrometry. Effects of gallopamil were measured by ECG
recording. RESULTS: The apparent oral clearances (R: 4.8 l min-1 (95% CI: 2.9
6.8); S: 5.5 l min-1 (95% CI: 2.5-8.5)) and half-lives (R: 6.2 h; S: 7.2 h) of R-
and S-gallopamil were similar (P >0.05). The serum protein binding (fu R: 0.035
(95% CI: 0.026-0. 045); S: 0.051 (95% CI: 0.033-0.069)) and the renal elimination
(% of dose R: 0.49%; S: 0.71%) were enantioselective. Gallopamil had a potent
effect on the PR interval (% prolongation 35.7% (95% CI: 14. 0-57.3)). No changes
in other electrocardiographic or cardiovascular parameters were observed.
CONCLUSIONS: The pharmacokinetics and bioavailability of the racemic drug
gallopamil are not stereoselective at steady-state and are therefore not
substantially altered compared with the single dose administration of gallopamil.
PMID- 10671908
TI - Formation of omeprazole sulphone but not 5-hydroxyomeprazole is inhibited by
grapefruit juice.
AB - AIMS: To determine the effect of grapefruit juice on omeprazole metabolism in
vivo. METHODS: This was a randomized crossover study with a 2 week washout
period. Omeprazole (20 mg) was taken orally by 13 healthy volunteers after an
overnight fast with either grapefruit juice or water. Serial blood samples were
obtained over 12 h and standardized meals were served 3 and 10 h after the
administration of omeprazole. Plasma concentrations of omeprazole and its major
metabolites, 5-hydroxyomeprazole and omeprazole sulphone, were determined by high
performance liquid chromatography (h.p.l.c.). RESULTS: Mean area under the plasma
concentration vs time curve (AUC) between 0 and 12 h for omeprazole sulphone was
approximately 20% lower (P<0.01) in the group receiving grapefruit juice. There
was no significant difference in the mean AUC of 5-hydroxyomeprazole or
omeprazole. The AUC ratio of omeprazole sulphone to omeprazole, an index of
CYP3A4 activity, was decreased by 33% (P<0.001) after administration of
grapefruit juice whereas the AUC ratio of 5-hydroxyomeprazole to omeprazole, an
index of CYP2C19 activity, did not differ between the two phases of the study.
Although the time to peak concentration (tmax ) and terminal half-life (t1/2,z)
of omeprazole and its two main metabolites were not altered, the peak
concentration (Cmax ) of omeprazole sulphone was significantly reduced after
administration of grapefruit juice. CONCLUSION: Administration of grapefruit
juice decreased the formation of omeprazole sulphone but not 5-hydroxyomeprazole.
These results indicate that activities of CYP3A4, but not of CYP2C19, are
inhibited by the simultaneous administration of grapefruit juice.
PMID- 10671909
TI - Phenotypic polymorphism and gender-related differences of CYP1A2 activity in a
Chinese population.
AB - AIMS: To investigate the distribution characteristics of CYP1A2 in a Chinese
population, and to examine gender-related differences in CYP1A2 activity.
METHODS: Two hundred and twenty-nine healthy subjects, 120 men and 109 women,
were enrolled in this study. CYP1A2 activity was measured by plasma
paraxanthine/caffeine (1,7X/1,3,7X) ratio 6 h after administration of 300 mg
caffeine. The concentrations of paraxanthine and caffeine in plasma were detected
by h.p.l.c. RESULTS: A 16-fold variation of CYP1A2 activity (range 0. 09 to 1.46)
was shown in this study. The coefficient of variation (CV %) of CYP1A2 activity
was 62.9%. Non-normal distribution of CYP1A2 activity was indicated by the
Shapiro-Wilk test (P<0.001). Probit plots of CYP1A2 activity revealed a bimodal
distribution with breakpoint of 1,7X/1,3,7X ratio of 0.12. The percentage of poor
metabolizers (PMs) was 5.24% (95% CI: 2.35% approximately 8.13%) in this Chinese
population. Residual analysis of the data also supported bimodality (P<0.01). The
CYP1A2 activity of men was higher than that of women (median: 0.33 vs 0.23,
P<0.001). A probit plot of CYP1A2 activity in men was shifted to the left
compared with that in women. Based on phenotype, the gender-related difference
was observed in extensive metabolizers (EMs) (P<0.001), but not in PMs (P >0.1).
In addition, there was no sex-related difference in the incidence of PMs (P
>0.1). CONCLUSIONS: There is a phenotypic polymorphism in CYP1A2 activity in this
Chinese population, and CYP1A2 activity is higher in men than that in women.
PMID- 10671910
TI - Stereoselective glucuronidation of formoterol by human liver microsomes.
AB - AIMS: Formoterol is a beta2-adrenoceptor agonist marketed as a racemic mixture of
the active (R; R)- and inactive (S; S)-enantiomers (rac-formoterol). The drug
produces prolonged bronchodilation by inhalation but there is significant
interpatient variability in duration of effect. Previous work has shown that in
humans formoterol is metabolized by conjugation with glucuronic acid but little
is known about the stereoselectivity of this reaction. The aim of the present
study was to investigate the glucuronidation of formoterol enantiomers in vitro
by human liver microsomes. METHODS: The kinetics of formation of formoterol
glucuronides during incubation of racemate and of single formoterol enantiomers
with human liver microsomes (n=9) was characterized by chiral h.p.l.c. assay.
RESULTS: The kinetics of glucuronidation of the two formoterol enantiomers obeyed
the Michaelis-Menten equation. Glucuronidation of formoterol was stereoselective
and occurred more than two times faster for (S; S)-formoterol than for (R; R)
formoterol. In incubations with single formoterol enantiomers, the median (n=9)
Km values for (R; R)-glucuronide and (S; S)-glucuronide were 827.6 and 840.4
microm, respectively, and the median V max values were 2625 and 4304 pmol min-1
mg-1, respectively. Corresponding values determined in incubations with rac
formoterol were 357.2 and 312.1 microm and 1435 and 2086 pmol min-1 mg-1 for (R;
R)- and (S; S)-glucuronide, respectively. Interindividual variation was large
with the ratio of V max/Km (S; S/R; R) ranging from 0.57 to 6.90 for incubations
with rac-formoterol. CONCLUSIONS: Our study demonstrates that glucuronidation of
formoterol by human liver microsomes is stereoselective and subject to high
interindividual variability. These findings suggest that clearance of formoterol
in humans is subject to variable stereoselectivity which could explain the
variation in duration of bronchodilation produced by inhaled formoterol in
patients with asthma.
PMID- 10671911
TI - Epidemiology of drug exposure and adverse drug reactions in two swiss departments
of internal medicine.
AB - AIMS: To explore drug exposure, frequency of adverse drug reactions (ADRs), types
of ADRs, predisposing risk factors and ADR-related excess hospital stay in
medical inpatients. METHODS: Structured data regarding patient characteristics,
'events' (symptoms, laboratory results), diagnoses (ICD10) and drug therapy were
collected using a computer-supported data entry system and an interface for data
retrieval from electronic patient records. ADR data were collected by 'event
monitoring' to minimize possible bias by the drug monitor. The causality of each
event was assessed in relation to disease(s) and drug therapy. RESULTS: The
analysis included 4331 (100%) hospitalizations. The median observation period was
8 days. The median number of different drugs administered per patient and day was
6 and varied between 4 (Q1 ) and 9 (Q3 ) different drugs in 50% of all hospital
days. In 41% of all hospitalizations at least one disease-unrelated event could
be possibly attributed to drug therapy. Clinically relevant ADRs occurred in 11%
of all hospitalizations. In 3.3% of all hospitalizations ADRs were the cause of
hospital admission. The incidence of possibly ADR-related deaths was 1.4. Factors
predisposing for clinically relevant ADRs were female gender and polypharmacy.
ADR-related excess hospital stay accounted for 8. 6% of hospital days.
CONCLUSIONS: These data demonstrate the feasibility of the developed 'event
monitoring' system for quantitative analysis of ADRs in medical inpatients. With
increasing numbers of recorded patients the pharmacoepidemiological database
provides a valuable tool to study specific questions regarding drug efficacy and
safety in hospitalized patients.
PMID- 10671912
TI - Modification of general practitioner prescribing of antibiotics by use of a
therapeutics adviser (academic detailer).
AB - AIMS: This was a pilot study of the use of a clinical pharmacist as a
therapeutics adviser (academic detailer) to modify antibiotic prescribing by
general practitioners. METHODS: Following a visit by the adviser (March-May), 112
general practitioners were recruited and randomised to control or active groups.
A panel of experts prepared a best practice chart of recommended drugs for upper
and lower respiratory tract infections, otitis media and urinary tract
infections. The adviser made a 10-15 min visit to each prescriber in the active
group (June-July), gave them the chart and discussed its recommendations briefly.
Doctors in the control group were not visited nor given the chart. Prescription
numbers for all prescribers were obtained from the Commonwealth Health Insurance
Commission for the pre(March-May) and postdetailing (August-September) periods
using a three month lag time for data collection. Data for total numbers of
prescriptions and for selected individual antibiotics used in these two periods
were analysed using nonparametric statistics. RESULTS: Prescribing patterns were
similar for the control and active groups in the predetailing period. For both
groups, there were significant (P<0.03) increases (45% for control and 40% for
active) in total number of antibiotic prescriptions in the post compared with the
predetailing period. This trend was anticipated on the basis of the winter
seasonal increase in respiratory infections. In line with the chart
recommendations for first-line treatment, doctors in the active group prescribed
significantly more amoxycillin (P<0.02) and doxycycline (P<0.001) in the post vs
predetailing periods. By contrast, doctors in the control group prescribed
significantly more cefaclor (P<0.03) and roxithromycin (P<0.03), drugs that were
not recommended. The total cost of antibiotics prescribed by doctors in the
control group increased by 48% ($37 150) from the preto postdetailing periods. In
the same time period, the costs for the active group increased by only 35% ($21
020). CONCLUSIONS: We conclude that the academic detailing process was successful
in modifying prescribing patterns and that it also decreased prescription numbers
and costs. Application of the scheme on a nationwide basis could not only improve
prescriber choice of the most appropriate antibiotic but also result in a
significant saving of health care dollars.
PMID- 10671913
TI - Sleeping with the enemy? A randomized controlled trial of a collaborative health
authority/industry intervention to influence prescribing practice.
AB - AIMS: To evaluate the effectiveness of a health authority/pharmaceutical company
collaborative intervention to influence the choice of proton pump inhibitors
METHODS: Randomized controlled trial, with general practices forming the unit of
allocation and analysis. RESULTS: Constructive working relationships were
achieved with five of six pharmaceutical companies involved. One hundred and two
out of 140 practitioners in intervention group practices received at least one
visit from an industry representative. There were no reports of representatives
operating outside their agreed remit. Prescribing in both the intervention and
control group moved towards that recommended by the guidelines but there was no
difference between the groups in either the proportion of prescriptions in line
with the guidelines or the overall cost. CONCLUSIONS: Health authorities can
achieve professional working relationships with the pharmaceutical industry
although no changes in practice attributable to the intervention are achieved.
Further work is required to develop effective means to influence prescribing in
line with independent guidelines especially in the context of the development of
Primary Care Groups.
PMID- 10671915
TI - Neuroendocrine tumours of the pancreas.
PMID- 10671914
TI - Inhibition of debrisoquine hydroxylation with quinidine in subjects with three or
more functional CYP2D6 genes.
AB - AIMS: To study whether the CYP2D6 capacity in ultrarapid metabolizers of
debrisoquine due to duplication/multiduplication of a functional CYP2D6 gene, can
be 'normalised' by low doses of the CYP2D6 inhibitor quinidine and whether this
is dose-dependent. METHODS: Five ultrarapid metabolizers of debrisoquine with 3,
4 or 13 functional CYP2D6 genes were given single oral doses of 5, 10, 20, 40, 80
and 160 mg quinidine. Four hours after quinidine intake, 10 mg debrisoquine was
given. Urine was collected for 6 h after debrisoquine administration.
Debrisoquine and its 4-hydroxymetabolite were analysed by h.p.l.c. and the
debrisoquine metabolic ratio (MR) was calculated. RESULTS: Without quinidine the
MR in the ultrarapid metabolizers ranged between 0.01 and 0.07. A dose-effect
relationship could be established for quinidine with regard to the inhibitory
effect on CYP2D6 activity. To reach an MR of 1-2, subjects with 3 or 4 functional
genes required a quinidine dose of about 40 mg, while the sister and brother with
13 functional genes required about 80 mg quinidine. After 160 mg quinidine, the
MRs, in the subjects with 3, 3, 4, 13 and 13 functional genes, were 12.6, 10.1,
9.2, 2.4 and 2.2, respectively. CONCLUSIONS: A dose-effect relationship could be
established for quinidine inhibition of CYP2D6 in ultrarapid metabolizers. The
clinical use of low doses of quinidine as an inhibitor of CYP2D6 might be
considered in ultrarapid metabolizers taking CYP2D6 metabolized drugs rather than
giving increased doses of the drug. Normalizing the metabolic capacity of CYP2D6,
by giving a low dose of quinidine, may solve the problem of 'treatment
resistance' caused by ultrarapid metabolism.
PMID- 10671916
TI - What should surgeons write?
PMID- 10671917
TI - COPE: Committee on Publication Ethics. Guidelines on good publication practice.
PMID- 10671918
TI - The 'failed' embolectomy.
PMID- 10671919
TI - Xenotransplantation.
AB - BACKGROUND: The success of clinical transplantation has led to a large
discrepancy between donor organ availability and demand; considerable pressure
exists to develop an alternative source of organs. The use of animal organs for
donation is a possible solution that is not yet clinically applicable. METHODS
AND RESULTS: A literature review was performed based on a Medline search to find
articles on xenotransplantation. Keywords included hyperacute, acute vascular,
xenograft rejection combined with concordant and discordant. Additional
references cited in these articles from journals not included in Medline were
obtained from the British Library. Limited information on unpublished,
preliminary work has been included from sources known to the authors, based on
their research work in the field. One hundred and forty-six references and four
personal communications have been included in this review article. CONCLUSION: A
greater understanding of the pathogenesis of xenograft rejection is developing
rapidly. Strategies to abrogate hyperacute rejection have proved successful, but
control of antibody-driven acute vascular rejection has not yet been achieved.
The safety and viability of xenotransplantation as a therapeutic modality are
still unproven.
PMID- 10671920
TI - Genetic predisposition to breast cancer: a surgical perspective.
AB - BACKGROUND: Molecular alterations in proto-oncogenes, tumour suppressor genes,
and genes that function in DNA damage recognition and repair are considered to be
hallmarks of a carcinogenic process, including breast carcinogenesis. METHODS: A
computer-assisted search of the English literature (Medline database, 1990-1999)
was performed, followed by a manual search of the reference list of pertinent
articles retrieved. RESULTS: Hereditary breast cancer accounts for 5-10 per cent
of all breast cancer cases. About 90 per cent of hereditary breast cancers
involve mutation of the BRCA1 and/or BRCA2 genes. Other cancer-related genes
(including myc, c-erbB2, Tsg101 and Mdgi) are involved in breast carcinogenesis,
but they do not give rise to familial breast cancer syndromes. Risk estimation is
the most important clinical implication. Management options for the high-risk
mutation carriers include cancer surveillance and preventive strategies
(prophylactic surgery or chemoprevention). CONCLUSION: Despite inadequate
knowledge about the genetic predisposition to breast cancer and its clinical
implications, the demand for genetic testing is likely to expand rapidly. In
addition to risk estimation, cancer surveillance and preventive strategies, gene
therapy offers a new and theoretically attractive approach to breast cancer
management.
PMID- 10671921
TI - Management of the axilla in operable breast cancer treated by breast
conservation: a randomized clinical trial. Edinburgh Breast Unit.
AB - BACKGROUND: In the treatment of operable breast cancer by breast conservation,
the extent of axillary dissection, the need for radiotherapy to the axilla and
the morbidity associated with these procedures have not been assessed adequately.
METHODS: Patients with operable breast cancer were randomized to have level III
axillary node clearance (232 patients) or axillary node sample (234 patients).
Radiotherapy to the axilla was given selectively. Radiotherapy was not given to
those who had an axillary clearance. In the early part of the study all patients
who had node sample were treated by radiotherapy (54 patients); subsequently this
was modified to include only those who were node positive. The morbidity to the
shoulder and arm was assessed before and after operation by measuring upper limb
volume and circumference, and combined glenohumeral and scapular movement and
muscle power. RESULTS: Comparing the two surgical policies, no difference was
found in local (axillary clearance 14 versus sample 15), axillary (eight versus
seven) or distant (29 versus 29) recurrence. There was no statistically
significant difference in 5-year survival rate (clearance 82.1 versus sample 88.6
per cent). Morbidity was least in those who had a node sample and no radiotherapy
to the axilla. Radiotherapy to the axilla in patients who had a node sample
resulted in a significant reduction in range of movement of the shoulder, e.g.
mean(s.e.) 2.2(0.6) cm reduction in lateral rotation at 3 years. Surgical
axillary clearance was associated with significant lymphoedema of the upper limb,
e.g. 4.1(0.7) per cent increase in arm volume at 3 years. CONCLUSION: A selective
policy for the management of the axilla is associated with no increase in
axillary recurrence or mortality rate compared with routine axillary node
clearance. Patients who are node negative after axillary sample can avoid
radiotherapy or axillary clearance.
PMID- 10671922
TI - Mutations of the cationic trypsinogen gene in patients with hereditary
pancreatitis.
AB - BACKGROUND: Hereditary pancreatitis has been shown to be caused by one of two
mutations (R117H and N21I) of the cationic trypsinogen gene (PRSS1). Families
with hereditary pancreatitis in the north of England were investigated for these
mutations. The clinical features associated with each mutation were compared.
METHODS: In individuals from nine families with hereditary pancreatitis, DNA was
screened for the R117H and N21I mutations. All five exons of the cationic
trypsinogen gene were also sequenced to search for additional mutations.
Haplotype analysis was carried out to identify common ancestors. Clinical data
were collected. RESULTS: The R117H mutation was identified in three families and
N21I in a further five. The R117H mutation was associated with a more severe
phenotype than N21I in terms of mean(s.d.) age of onset of symptoms (8.4(7.2)
versus 16. 5(7.1) years; P = 0.007) and requirement for surgical intervention
(eight of 12 versus four of 17 patients respectively; P = 0.029). Haplotype
analysis suggested that each mutation had arisen more than once. CONCLUSION: Two
mutations in the cationic trypsinogen gene cause hereditary pancreatitis in eight
of nine families originating in this region. The R117H mutation is associated
with a more severe form of the disease in terms of age at onset of symptoms and
requirement for surgical intervention.
PMID- 10671923
TI - Role of relaparoscopy in the management of minor bile leakage after laparoscopic
cholecystectomy.
AB - BACKGROUND: Bile leakage in the absence of major ductal injury may occur from the
liver bed or from the cystic duct remnant after cholecystectomy. The early
limitations of minimally invasive surgery led to reliance on endoscopic methods
to manage this complication. However, repeat laparoscopy permits drainage of the
bile collection and direct control of the site of leakage in selected situations.
METHODS: Details of 15 patients with bile leakage after laparoscopic
cholecystectomy were recorded prospectively and are reviewed. RESULTS:
Postoperative bile leakage occurred after 15 (0.8 per cent) of 1779 laparoscopic
cholecystectomies. Two patients with bile in drainage fluid had spontaneous
resolution. Ten patients with a subvesical duct leak had repeat laparoscopy. The
leak was successfully controlled by suturing in eight patients, and by a
laparoscopically placed drain in two. One patient required a subsequent
laparotomy for a loculated pelvic collection. Three patients had cystic duct
stump leakage. This was managed successfully by laparoscopy in one case but
required endoscopic management in two. CONCLUSION: Laparoscopy is useful in the
management of minor bile leaks after laparoscopic cholecystectomy. Selection of
appropriate patients relies on a characteristic clinical presentation after an
otherwise uncomplicated cholecystectomy.
PMID- 10671924
TI - Role of biliary scintiscan in predicting the need for cholangiography.
AB - BACKGROUND: Currently used predictors for bile duct calculi in patients
undergoing cholecystectomy have low specificity resulting in unnecessary
cholangiograms being performed. The role of biliary scintiscan in predicting the
presence of bile duct calculi was assessed. METHODS: Seventy-five patients with
symptomatic gallstone disease were studied prospectively regard- ing the value of
a history of jaundice or acute pancreatitis, raised serum bilirubin and serum
alkaline phosphatase levels, and visualization of stones or presence of dilated
bile ducts on ultrasonography (standard criteria) in detecting bile duct calculi.
Results of biliary scintiscan were evaluated against a combination of standard
criteria. The 'gold standard' for evaluation was endoscopic or peroperative
cholangiography. RESULTS: Biliary scintiscan had a higher sensitivity and
specificity (93 and 94 per cent) than a combination of the above standard and
modified predictors for biliary calculi (89 and 71 per cent). A combination of
ultrasonography and selective use of scintiscan, in the absence of bile duct
dilatation only, had higher values (96 and 98 per cent). CONCLUSION: A
combination of ultrasonography and biliary scintiscan can accurately predict bile
duct calculi and could be used as a guide for selective cholangiography.
PMID- 10671925
TI - Spontaneous carotid artery aneurysms.
AB - BACKGROUND: Spontaneous carotid artery aneurysms are infrequently reported, and
are almost always non-atherosclerotic. METHODS: The records of 29 patients with a
spontaneous carotid aneurysm treated in an academic vascular unit between 1990
and 1998 were reviewed. RESULTS: All 29 patients were black South Africans; three
had bilateral aneurysms. There were 24 men and five women, of mean age 35 (range
13-62) years. Some 25 aneurysms involved the common carotid artery, 12 of which
affected the bifurcation, and seven were located in the internal carotid artery.
Twenty-five aneurysms were managed surgically, four of which were ligated owing
to sepsis. Histo- logical evaluation showed human immunodeficiency virus-related
arteritis in four, tuberculous aneurysms in ten, Takayasu's arteritis in two,
atherosclerosis in three and non-specific chronic inflammation in four patients.
Microbiological examination was negative in all but one patient who had
Salmonella sp. cultured. Outcome was generally favourable, but one patient died
from massive hemispheric infarction. There were no other new neurological
deficits. CONCLUSION: Carotid aneurysms pose a considerable surgical challenge
but are amenable to operative intervention with good result. Ligation appears to
be well tolerated in this group of predominantly non-atherosclerotic aneurysms.
PMID- 10671926
TI - Influence of gender on outcome from ruptured abdominal aortic aneurysm.
AB - BACKGROUND: The aim of the present study was to compare outcomes following
ruptured abdominal aortic aneurysm (AAA) in men and women. METHODS: Overall
mortality from ruptured AAA was compared in men and women using the Western
Australia Health Services Research Database. The linked chains of de-identified
hospital morbidity and death records were selected using the ICD-9-CM
(International Classification of Diseases - Clinical Modification) diagnostic and
procedure codes pertaining to AAA. Cases were divided into three groups for
analysis: patients who died without admission to hospital, those admitted to
hospital with a ruptured AAA but who did not undergo operation, and patients who
underwent operation for ruptured AAA. RESULTS: Ruptured AAA occurred in 648 men
and 225 women over the age of 55 years during the decade 1985-1994. Only 50 per
cent of women, compared with 59 per cent of men, were admitted to hospital. Of
those admitted to hospital only 37 per cent of women underwent operation,
compared with 63 per cent of men. The overall mortality rate from ruptured AAA
was 90 per cent in women and 76 per cent in men (chi2 = 50.34, 1 d.f., P <
0.0001). Although women were, on average, 6 years older than men, this
unfavourable pattern occurred across all age groups. CONCLUSION: Women with a
ruptured AAA are more likely to die than men. More research is required to
identify the causes of this sex difference.
PMID- 10671927
TI - Quantifying the risks of hypertension, age, sex and smoking in patients with
abdominal aortic aneurysm.
AB - BACKGROUND: The prevalence of abdominal aortic aneurysm (AAA) in a community
based sample of men and women aged 65-79 years was correlated with known risk
factors. In addition, the effect of high blood pressure and the use of
antihypertensive medication on growth of AAAs were studied. METHODS: Aortic
diameter was assessed by ultrasonography and data on risk factors were collected
by self-administered questionnaire for 5356 men and women as part of a randomized
controlled trial. RESULTS: Current hypertension increased the risk of having an
aortic aneurysm by 30-40 per cent while use of antihypertensive medication
increased the risk by 70-80 per cent, adjusting for current blood pressure. There
was no clear relationship between hypertension and growth rates of existing
aneurysms in this study, although these results were largely from data on small
aneurysms. Men were nearly six times more likely to develop an AAA than women;
the risk increased by 40 per cent every 5 years after the age of 65 years.
Smoking was an independent risk factor for AAA, with level of exposure being more
significant than duration. CONCLUSION: Male sex, smoking and hypertension are
strong risk factors for the development of AAA. In this study hypertension did
not significantly increase the growth rate of existing aneurysms. Smoking remains
the most important avoidable risk factor for AAA. The analyses presented here
suggest that selection for screening, other than by age and sex, is not
worthwhile.
PMID- 10671928
TI - Diaphragmatic dysfunction secondary to experimental lower torso ischaemia
reperfusion injury is attenuated by thermal preconditioning.
AB - BACKGROUND: Preconditioning describes the process whereby tissue exposure to a
subcritical stress confers protection from subsequent injuries. This study
assessed diaphragmatic muscle function after lower torso ischaemia-reperfusion
(IR) and the role of thermal preconditioning in attenuation of this injury.
METHODS: Sprague-Dawley rats were randomized into three groups (24 per group): a
control group, an IR group that had aortic cross-clamping for 1 h followed by
reperfusion, and a third group that received thermal preconditioning 18 h before
IR. Diaphragmatic function was assessed at 24 h, 48 h and 7 days. RESULTS: IR
resulted in significant diaphragmatic twitch and tetanic dysfunction compared
with control muscle. Thermal preconditioning significantly attenuated this injury
(P < 0.05). Mean(s.e.m.) muscle twitch and tetanic forces in the IR group were
204.9(17.2) and 282.7(19.2) g respectively at 24 h. Corresponding twitch and
tetanic forces in preconditioned muscle were 270.4(25.1) and 552.0(35.2) g.
CONCLUSION: This study demonstrated that systemic IR injury produced a
respiratory muscle mechanical dysfunction that was attenuated by thermal
preconditioning, at 24 h, 48 h and 7 days. Preconditioning may have a role in
clinical practice, particularly before elective surgery.
PMID- 10671929
TI - Bladder and sexual dysfunction after mesorectal excision for rectal cancer.
AB - BACKGROUND: Urinary and sexual dysfunction are recognized complications of rectal
excision for cancer. The aim of this study was to examine the frequency of such
complications after mesorectal excision, shortly after this method was
introduced. METHODS: Spontaneous flowmetry, residual volume of urine measurement
and urodynamic examination, including cystometry and simultaneous detrusor
pressure and urinary flow recording, was carried out before and 3 months after
curative rectal excision. Urinary symptoms and sexual function were evaluated by
means of questionnaires before and after operation. Each patient served as his or
her own control. RESULTS: Forty-nine consecutive patients, 39 of whom had a total
mesorectal excision (TME) and ten a partial mesorectal excision, were examined
before surgery and 35 again after operation. In two patients, a weak detrusor was
detected before operation. Two patients developed signs of bladder denervation
after operation. Transitory moderate urinary incontinence appeared in four other
women. Six of 24 men reported some reduction in erectile function and one became
impotent. Two men reported retrograde ejaculation. All the complications were
seen in the TME group. CONCLUSION: Mesorectal excision for rectal cancer resulted
in a low frequency of serious bladder and sexual dysfunction.
PMID- 10671930
TI - Prolonged ambulatory recording of antroduodenal motility in slow-transit
constipation.
AB - BACKGROUND: Slow-transit constipation may be part of a pan-enteric motor
disorder. To test this hypothesis 24-h ambulatory antroduodenal manometry was
performed and orocaecal transit time determined in patients with slow-transit
constipation and in healthy controls. METHODS: Antroduodenal motility was
recorded with a five-channel solid-state catheter. Postprandial motility was
recorded after consumption of two standardized test meals and interdigestive
motility was recorded nocturnally. Manometry tracings were analysed for
quantitative and qualitative abnormalities. Orocaecal transit time was determined
by means of the lactulose hydrogen breath test. RESULTS: Postprandial motility
was no different between patients and controls. However, some minor changes of
interdigestive motility were observed. The proportion of phase II activity of the
nocturnal cycles of the interdigestive migrating motor complex was increased in
patients while phase I activity was decreased. The total number of observed phase
III fronts was no different in patients and controls, although the number of
phase III fronts with antral onset was decreased. Furthermore, the amplitude of
phase III activity of duodenal onset was also decreased. Specific motor
abnormalities such as retrograde propagation of phase III fronts were more
frequent in patients. Orocaecal transit time was delayed in patients. CONCLUSION:
In patients with slow-transit constipation, orocaecal transit time is delayed but
antro- duodenal motility is generally well preserved with only minor alterations.
Presented as a poster to the Digestive Disease Week meeting in New Orleans,
Louisiana, USA, May 1998, and published in abstract form as Gastroenterology
1998; 114: A820
PMID- 10671931
TI - Evaluation of Delorme's procedure as a treatment for full-thickness rectal
prolapse.
AB - BACKGROUND: Delorme's procedure is a well tolerated perineal operation for full
thickness rectal prolapse. However, prolapse recurrence is common and reported
recurrence rates vary widely. This study attempted to standardize outcome
assessment for recurrence following primary and subsequent Delorme's operations.
Patient and operative factors were analysed to identify any that might improve
patient selection. METHODS: Some 101 primary and 17 secondary Delorme's
procedures were carried out on 113 consecutive patients presenting with rectal
prolapse, who were followed for a minimum of 12 months, unless death or recurrent
prolapse intervened. The rate of prolapse recurrence was calculated using the
Kaplan-Meier method of analysis. Patient age, sex, grade of incontinence,
presence of diverticular disease, length of mucosal resection and position in the
operative series were analysed to identify factors affecting recurrence. RESULTS:
The predicted recurrence-free period for 50 per cent of patients undergoing
primary and secondary Delorme's procedures was 91 (95 per cent confidence
interval 77-105) and 27 (15-39) months respectively. None of the patient or
operative factors analysed was related to recurrent prolapse. CONCLUSION:
Delorme's procedure is a simple operation with satisfactory functional results
which can be considered in all patients of all ages. However, high recurrence
rates for primary and repeat operations should be explained to patients when
planning their surgical management.
PMID- 10671932
TI - Lymphocyte activation after non-thermal trauma.
AB - BACKGROUND: Severe injury causes immunological changes that may contribute to a
poor outcome. Longitudinal characterization of lymphocyte response patterns may
provide further insight into the basis of these immunological alterations.
METHODS: Venous blood obtained seven times over 2 weeks from 61 patients with
injury severity scores above 20 was assessed for lymphocyte phenotypic and
activation markers together with serum levels of interleukin (IL) 2, IL-4,
soluble IL-2 receptor (sIL-2R), soluble CD4 (sCD4), soluble CD8 (sCD8) and
interferon gamma. RESULTS: Severe injury was associated with profound changes in
the phenotypic and activation profile of circulating lymphocytes. Activation was
indicated by increased numbers of T cells expressing CD25, CD69 and CD71, and
raised serum levels of IL-2, sIL-2R, sCD4 and sCD8. Relatively higher levels of
sIL-2R and sCD4 were found in patients with sepsis syndrome. CONCLUSION:
Polytrauma is associated with dramatic alterations in the phenotypic and
activation profile of circulating lymphocytes which are generally independent of
clinical course. In contrast, several lymphocyte soluble factors, including sCD4
and sIL-2R, paralleled the clinical course. These data provide new insight into
lymphocyte responses after injury and suggest that further assessment of soluble
factors as clinical correlates, including those related to lymphocyte activation
or generalized inflammation, may be warranted.
PMID- 10671933
TI - Acrylate yellow filters in operating lights protect against photosensitization
tissue damage.
AB - BACKGROUND: Photosensitized patients are exposed to bright lights when undergoing
intraoperative photodynamic therapy or fluorescence measurements. Acrylate yellow
filters might reduce unwanted tissue damage. METHODS: To investigate the
protective value of these filters, the spectral power distribution of the
operating lights and light energy densities with and without an acrylate yellow
filter were measured. Subsequently the effects of light exposure on the survival
of a human hepatocellular carcinoma cell line and the photodamage induced in pig
tissues after the administration of 5-aminolaevulinic acid were also studied.
RESULTS: The light energy density in the ultraviolet and blue region of the light
spectrum emitted by the operating light was reduced up to 50 per cent by the
acrylate yellow filter. The survival of photosensitized cells was longer and
photodamage induced in pig tissues was less when exposed to filtered light.
CONCLUSION: Photodamage induced by operating lights can be reduced by filtering
out ultraviolet and blue light by means of acrylate yellow filters.
PMID- 10671934
TI - Recurrence following curative resection for gastric carcinoma.
AB - BACKGROUND: The diagnosis and treatment of recurrent gastric cancer remains
difficult. The aim of this study was to determine the risk factors for recurrence
of gastric cancer and the prognosis for these patients. METHODS: Of 2328 patients
who underwent curative resection for gastric cancer from 1987 to 1995, 508 whose
recurrence was confirmed by clinical examination or reoperation were studied
retrospectively. The risk factors that determined the recurrence patterns and
timing were investigated by univariate and multivariate analysis. RESULTS: The
mean time to recurrence was 21.8 months and peritoneal recurrence was the most
frequent (45.9 per cent). Logistic regression analysis showed that serosal
invasion and lymph node metastasis were risk factors for all recurrence patterns
and early recurrence (at 24 months or less). In addition, independent risk
factors involved in each recurrence pattern included younger age, infiltrative or
diffuse type, undifferentiated tumour and total gastrectomy for peritoneal
recurrence; older age and larger tumour size for disseminated, haematogenous
recurrence; and older age, larger tumour size, infiltrative or diffuse type,
proximally located tumour and subtotal gastrectomy for locoregional recurrence.
Other risk factors for early recurrence were infiltrative or diffuse type and
total gastrectomy. Reoperation for cure was possible in only 19 patients and the
mean survival time after conservative treatment or palliative operation was less
than 12 months. CONCLUSION: The risk factors for each recurrence pattern and
timing of gastric cancer can be predicted by the clinicopathological features of
the primary tumour. Since the results of treatment remain dismal, studies of
perioperative adjuvant therapy in an attempt to reduce recurrence are warranted.
PMID- 10671935
TI - Surgical treatment for recurrent gastro-oesophageal reflux disease after failed
antireflux surgery.
AB - BACKGROUND: Recurrent or persistent symptoms occur in 10-15 per cent of patients
after antireflux surgery. Failure of surgery is not uniform in its presentation.
The cause of failure is not easily detected and even harder to treat. Different
approaches have been proposed and few reports are available on the objective and
subjective outcome of reoperation. METHODS: This study focuses on 30 patients (16
men and 14 women; age range 20-69 years) with recurrent symptomatic gastro
oesophageal reflux disease (GORD) resistant to medical treatment. In all patients
reoperation was by the Belsey Mark IV antireflux operation. A clinical history,
endoscopy and oesophageal manometry were obtained in all patients, and 24-h pH
monitoring was performed in 27 of 30 before and in most patients after the Belsey
procedure. RESULTS: Symptomatic improvement was reported in 24 of 30 patients.
Oesophagitis (present before operation in 19 patients) was cured or remained
absent in 24 of 30 patients, stabilized in one, improved in four and deteriorated
in one. Relief of symptoms combined with absence of oesophagitis was obtained in
21 of 30 patients, with concomitant normalization of the 24-h pH profile in 11 of
22 patients. The median basal lower oesophageal sphincter (LOS) pressure
increased significantly from 6. 9 to 9.0 mmHg (P < 0.01). Redo surgery had no
effect on oesophageal body motility. CONCLUSION: Reoperation performed for
documented recurrent GORD had a good and lasting effect on symptoms, on
oesophagitis (both in 24 of 30 patients) and on the combination of both (21 of
30). In these patients reoperation increased basal LOS pressure and decreased
reflux time. Overall, the results approximate to those of primary operation.
PMID- 10671936
TI - Screening children at risk of developing inherited endocrine neoplasia syndromes.
PMID- 10671937
TI - New causes of Cushing's syndrome: abnormal adrenal regulation of cortisol
production.
PMID- 10671938
TI - CTLA4 variants in type 1 diabetes: some stirrups serve better backing endocrine
autoimmunity.
PMID- 10671939
TI - Application of a disease-specific, quality-of-life measure (QoL-AGHDA) in growth
hormone-deficient adults and a random population sample in sweden: validation of
the measure by rasch analysis.
PMID- 10671940
TI - Application of a disease-specific, quality-of-life measure (QoL-AGHDA) in growth
hormone-deficient adults and a random population sample in Sweden: validation of
the measure by rasch analysis.
AB - OBJECTIVE: Growth hormone deficiency (GHD) in adults has been associated with
impaired health status and quality of life (QoL) in several studies using generic
measures, and in a few studies using recently developed disease-specific
measures. Theoretically, disease-specific measures may be more sensitive and
succinct than generic measures, and hence prove convenient for general use in
clinical practice. The present study sought to validate the scaling properties of
the disease-specific QoL-AGHDA measure through the implementation of Rasch
analysis. The study also sought to compare, by using the QoL-AGHDA, the QoL of a
relatively large Swedish cohort of adults with untreated GHD with that of a
reference population also from Sweden. PATIENTS: The QoL of 111 adults with
untreated GHD from Stockholm and Goteborg was compared with that of 1448 adult
subjects randomly selected from the population of Goteborg. MEASUREMENTS: The
scaling properties of the QoL-AGHDA were assessed by investigating its fit to a
dichotomous Rasch model. Rasch-transformed QoL scores from the QoL-AGHDA
questionnaire were stratified by age and gender, and 95% confidence intervals
were calculated. RESULTS: Rasch analysis of the QoL-AGHDA indicated the measure
to be robust in terms of its unidimensionality and ordering properties, and lack
of differential item functioning. The raw scores produced by the QoL-AGHDA are at
the ordinal level. Non-overlapping 95% confidence intervals of Rasch-transformed
interval scores in most age categories indicated that men and women with GHD had
significantly lower QoL than the reference population. CONCLUSION: The Swedish
QoL-AGHDA has good scaling properties, and hence can be considered a robust
measure. It is suitable for assessing quality of life in adults with GH
deficiency, and for making comparisons with adults who are not growth hormone
deficient. Adult GH deficiency is associated with a significant impairment in
QoL.
PMID- 10671941
TI - Association of CTLA4 gene A-G polymorphism with type 1 diabetes in Chinese
children.
AB - OBJECTIVE: The CTLA4 (cytotoxic T lymphocyte associated antigen-4) gene encodes
the T cell receptor involved in the control of T cell proliferation and mediates
T cell apoptosis. Thus it is a strong candidate gene for T cell-mediated
autoimmune disease. There is polymorphism at position 49 in exon 1 of the CTLA4
gene, providing a A-G exchange. This polymorphism is reportedly associated with
type 1 diabetes in Caucasians but not in a small data set of Chinese. We wished
to test this polymorphism in a larger and more homogeneous data set of Chinese
children with type 1 diabetes and normal adult controls. DESIGN: A population
based case-control study of a CTLA4 gene 49 A-G polymorphism was performed to
look for an association with type 1 diabetes in Chinese children. PATIENTS: We
analysed this polymorphism in 253 unrelated children (128 boys) with type 1
diabetes (age at diagnosis 7.1 +/- 3.7 years) and 91 randomly selected normal
adults. All individuals were Han Chinese. RESULTS: The genotype and gene
frequencies of children with type 1 diabetes differed significantly from those of
adult controls (P = 0.0091 and P = 0.0051, respectively). Genotype CTLA4 49 G/G
and G allele conferred a risk of type 1 diabetes (RR = 2.13, 95% CI = 1.31-3.46,
P = 0.0022; RR = 1.68, 95% CI = 1.17-2.43, P = 0.0051, respectively).
CONCLUSIONS: This study demonstrates that CTLA4 49 A-G polymorphism is associated
with type 1 diabetes in Han Chinese children. The CTLA4 49 G allele confers an
increased risk of type 1 diabetes.
PMID- 10671942
TI - Insulin sensitivity and secretion influence the relationship between growth
hormone-binding-protein and leptin.
AB - BACKGROUND: A direct relationship between body mass index (BMI), visceral adipose
tissue, insulin levels and growth hormone-binding protein (GHBP) activity has
consistently been reported. It was recently described that GHBP directly depends
on serum leptin levels. Since leptin co-varies with insulin secretion and/or
sensitivity, we aimed to study the influence of these variables on plasma GHBP
activity. SUBJECTS: In order to isolate the effects of obesity per se from those
of insulin secretion, three groups of subjects were prospectively studied: 14
lean, 10 obese and nine obese subjects with glucose intolerance. MEASUREMENTS:
The percentage of body fat was measured through bioelectric impedance. Insulin
sensitivity and secretion were determined through a frequently sampled
intravenous glucose tolerance test with minimal model analysis. Serum leptin was
measured by radioimmunoassay. GHBP activity was determined by the high
performance liquid chromatography-gel filtration method. RESULTS: Plasma GHBP
activity was found to correlate with BMI (r = 0. 65, P < 0.0001), fat mass (r =
0.51, P = 0.003), waist circumference (r = 0.64, P < 0.0001), waist-to-hip ratio
(r = 0.42, P = 0.01), insulin sensitivity (SI, r = - 0.61, P = 0.0001), insulin
secretion (expressed as the acute insulin response to intravenous glucose, AIRg)
(r = 0.48, P = 0.006) and leptin concentration (r = 0.49, P = 0.004). The
associations with SI (r = - 0.42, P = 0.02) and AIRg (r = 0.38, P = 0.03)
persisted even after controlling for fat mass. Since insulin secretion and
insulin sensitivity usually covary in glucose tolerant subjects (an increased
insulin secretion is necessary to compensate a decreased insulin sensitivity), we
constructed a multiple linear regression to predict GHBP activity. In this model,
SI (P = 0.005), AIRg (P = 0.02) and SD score-leptin (P = 0.03) independently
contributed to 34, 10 and 8% of the variability in serum GHBP activity.
CONCLUSIONS: Our results suggest that plasma GHBP activity is simultaneouslly
influenced by insulin secretion and sensitivity and leptin. Perhaps leptin,
through increased insulin secretion, might induce GHBP/GH secretion, explaining
the normal to high insulin-like growth factor (IGF)-I levels found in
overnutrition.
PMID- 10671943
TI - Serum levels of growth hormone binding protein in children with normal and
precocious puberty: relation to age, gender, body composition and gonadal
steroids.
AB - AIM: To study the regulation of GHBP serum levels by gonadal steroids in normal
and precocious puberty. STUDY PROTOCOL: We studied GHBP levels in relation to
age, sex, pubertal maturation, body composition as well as to circulating IGF-I
and gonadal steroid levels in 320 healthy children. Furthermore, we studied the
regulation of circulating GHBP in 33 girls with central precocious puberty before
and during gonadal suppression with GnRH agonist. METHODS: GHBP was determined by
a time-resolved fluoroimmunoassay (GHBP TR-FIA) based on a commercially available
immunoassay for GH, the DELFIA GH assay. RESULTS: In healthy children GHBP levels
were significantly higher in normal girls compared with boys, and there was no
significant increase in GHBP in puberty in both sexes. GHBP levels did not
correlate with height (SDS), age, pubertal stage, IGF-I or
testosterone/oestradiol levels in boys and girls, respectively. There were
significant correlations between BMI and GHBP in boys and girls (R 2 = 0.14 and R
2 = 0.12, both P < 0.0001). Furthermore, GHBP correlated highly significantly
with the percentage body fat, determined by BIA in 43 healthy girls (R 2 = 0. 40,
P < 0.0001). GHBP levels were significantly higher in girls with central
precocious puberty (CPP) (1.31 SDS (1.26), mean (SD)) compared to prepubertal
controls (P < 0.0001), and above + 2 SD in 10 out of 33 patients. In girls with
CPP, GHBP correlated inversely with oestradiol before treatment (R 2 = 0.26, P <
0.01) and there was a tendency towards a positive correlation with BMI (R 2 =
0.13, P = 0.078). By contrast, there were no signficant correlations between GHBP
and IGF-I or height SDS. Gonadal suppression with GnRH agonist treatment caused a
transient significant increase of 0.57 SD after 2 months of treatment (P <
0.001), but decreased to baseline levels hereafter. CONCLUSION: We conclude that
in children, as in adults, body fat is the primary determinant for the
circulating level of GHBP, and that the difference in body fat is probably the
main factor for the higher levels of serum GHBP in girls compared with boys, as
well as for the negative influence of testosterone levels in boys and of
oestrogen levels in girls. The elevation in GHBP levels observed in girls with
central precocious puberty is probably due their higher body fat content.
PMID- 10671944
TI - Administration of recombinant human growth hormone on alternate days is
sufficient to increase whole body protein synthesis and lipolysis in growth
hormone deficient adults.
AB - OBJECTIVE: At present, the duration of the effect of recombinant human growth
hormone (rhGH) on the rates of protein synthesis and lipolysis in GH deficient
(GHD) adults is unknown. This study was designed to establish the frequency of
rhGH administration necessary to provide the beneficial metabolic effects of the
hormone in GHD adults. DESIGN AND PATIENTS: Two different studies (A and B) were
performed in two groups of five GHD men. In study A, whole body protein and lipid
kinetics was determined in the basal state (Bas), 12 (GH12h) and 36 (GH36h) h
after the last of seven injections of rhGH (3.3 microg/kg), given at bedtime on
alternate days. In study B, the same parameters were determined in the basal
state (Bas), 60 (GH60h) and 84 (GH84h) h after the last of seven injections of
rhGH (3.3 microg/kg), given at bedtime at 3 day intervals. MEASUREMENTS: The
rates of protein metabolism were estimated by infusing [1-13C]leucine, and those
of lipolysis by infusing [1,1,2,3, 3-D5]glycerol. RESULTS: Leucine oxidation
decreased (P < 0.01) by approximately 30% after GH12h and GH36h but did not
change after GH60h and GH84h. Non-oxidative leucine disposal increased after
GH12h and GH36h by approximately 13% (P < 0.05) whereas it did not change after
GH60h and GH84h. Glycerol appearance increased (P < 0. 01) by approximately 45%
after GH12h and GH36h but did not change after GH60h and GH84h. CONCLUSIONS: The
effects on protein and lipid metabolism following the injection of rhGH last
longer than 36 and less than 60 h. In fact, rhGH administration on alternate days
induced a sustained increase in the rates of protein synthesis and lipolysis of
GHD adults, whereas a longer interval of administration (3 days) had no effect by
60 h.
PMID- 10671945
TI - Insulin-like growth factor I administration induces fluid and sodium retention in
healthy adults: possible involvement of renin and atrial natriuretic factor.
AB - OBJECTIVE: Growth hormone induces fluid and sodium retention. The underlying
mechanism is, however, incompletely understood. A possible mediator could be IGF
I. To investigate the impact of IGF-I administration on body fluid distribution
and sodium homeostasis in healthy subjects, we examined normal subjects during
six days IGF-I treatment and during a six-day control period. DESIGN AND
MEASUREMENTS: Eight normal male subjects aged 23-30 years were randomised to
receive IGF-I 50 microg/kg subcutaneously thrice daily during a six day study
period, and to a six day control period. After each study period, extracellular
volume and plasma volume (ECV, PV) were determined using 82Br and 125I-albumin.
Blood samples, urinary sodium excretion, and bioimpedance were measured every
second day of each study period. RESULTS: Serum IGF-I (microg/l) increased during
active treatment (control, 293 +/- 9; IGF-I, 628 +/- 42; P < 0.01). ECV (l) was
expanded by IGF-I (control, 18.42 +/- 0.28; IGF-I, 19.72 +/- 0.50; P < 0.05)
whereas PV (l) remained unaffected (control, 3.76 +/- 0.11; IGF-I, 3.80 +/- 0.16;
n.s.). Likewise, bioimpedance and body weight were unchanged by IGF-I. Plasma
renin (mU/l) increased but not significantly during IGF-I (control, 28.7 +/- 2.7;
IGF-I, 39.9 +/- 4.3; P = 0.08), and plasma aldosterone was unaffected by IGF-I. N
Terminal proANF (pmol/l) was suppressed during IGF-I administration (control, 422
+/- 32; IGF-I, 330 +/- 20; P < 0.05). Diurnal sodium excretion (mmol) was reduced
during IGF-I administration (control, 151 +/- 8; IGF-I, 124 +/- 7; P < 0.05).
CONCLUSION: IGF-I treatment causes fluid and sodium retention. This may be
mediated by increased renin release and suppression of atrial natriuretic factor.
The present data suggest that the fluid and sodium retaining effect of GH is at
least partly mediated through IGF-I.
PMID- 10671946
TI - Association of elevated insulin-like growth factor binding protein-1 with insulin
resistance in hyperthyroidism.
AB - OBJECTIVE: Insulin-like growth factor binding-protein-1 (IGFBP-1) has a role in
glucose homeostasis and is present at high concentrations in hyperthyroidism. We
have investigated the relationship between IGFBP-1 concentration and glucose
homeostasis in hyperthyroidism. DESIGN: Patients and controls had intravenous
glucose tolerance tests (IVGTT) and/or oral glucose tolerance tests (OGTT).
Patients were tested when hyperthyroid and when euthyroid whilst the controls
were tested once. The IVGTT was used to assess insulin sensitivity and the OGTT
to establish that the study group had abnormal glucose tolerance. The
hyperthyroid patients were treated with methimazole to restore euthyroidism.
PATIENTS: Ten patients (9 females) and 13 healthy controls (9 females) consented
to the study. Ten patients and nine controls (7 females) had IVGTT. Six patients
(5 females) and six controls (4 females) had OGTT. MEASUREMENTS: Glucose,
insulin, glucagon, GH and IGFBP-1 were measured during GTT. IGF-I, free thyroid
hormones, and TSH concentrations were measured basally. RESULTS: Hyperthyroid
subjects were insulin resistant and 67% had impaired glucose tolerance. Fasting
IGFBP-1 levels were doubled in hyperthyroid subjects compared to healthy controls
and correlated positively with free T4 (r = 0.84, P < 0.0001), with peak glucose
during the OGTT (r = 0.68, P < 0.005) with peak insulin during the IVGTT (r =
0.51, P < 0.005) and negatively with glucose disappearance constant (r = - 0.52,
P < 0.005). IGFBP-1 was highly phosphorylated in hyperthyroid and control
subjects. Fasting insulin and IGFBP-1 levels were unrelated but IGFBP-1
suppressed acutely during GTT in all groups. GH levels fell less in patients with
hyperthyroidism than in normals during GTTs. CONCLUSIONS: We conclude that in
hyperthyroidism thyroid hormones directly increase fasting IGFBP-1 concentration
but acute regulation of IGFBP-1 by insulin is normal and that elevated fasting
phosphorylated IGFBP-1 concentration is associated with insulin resistance.
PMID- 10671947
TI - Testicular dysfunction in men with primary hypothyroidism; reversal of
hypogonadotrophic hypogonadism with replacement thyroxine.
AB - OBJECTIVE: Primary hypothyroidism can cause disturbances in normal gonadal
function. The aim of this study was to investigate the relationship in men
between hypogonadism and primary hypothyroidism and the extent to which free and
total testosterone levels rose after introduction of replacement thyroxine.
DESIGN: Paired study of patients in a hypothyroid and thyroxine treated state.
PATIENTS: Ten men with primary hypothyroidism. MEASUREMENTS: Free and total
testosterone, gonadotrophin and prolactin levels before and after thyroxine
replacement therapy. RESULTS: Low free testosterone levels (161 +/- 62 pmol/l)
demonstrated at the time the men were hypothyroid rose significantly with the
commencement of thyroxine replacement (315 +/- 141 pmol/l; P < 0.001).
Gonadotrophin levels were not elevated consistent with hypogonadotrophic
hypogonadism. Hyperprolactinaemia, which can occur in primary hypothyroidism and
cause hypogonadotrophic hypogonadism, was not present in the majority of these
patients. However a reduction in prolactin level was evident with thyroxine
replacement and a rise in free testosterone levels. CONCLUSION: This suggests an
effect of hypothyroidism on gonadotrophin secretion at the level of the
hypothalamus-pituitary, either directly or through modulation of prolactin
secretion. Low free testosterone may also be a contributing factor to some of the
symptoms and signs of hypothyroidism in men.
PMID- 10671948
TI - Parathyroidectomy for primary hyperparathyroidism induces positive uncoupling and
increases bone mineral density in cancellous bones.
AB - OBJECTIVE: Osteopenia is an important feature of primary hyperparathyroidism
(PHP). However, little is known about the change of bone mineral density (BMD) in
PHP after surgery. The aim was to investigate the mechanisms of increased BMD
after parathyroidectomy in patients with PHP. DESIGN: Prospective observational
study. PATIENTS: Ten patients with PHP (7 women, 3 men; mean age 53.2+/-9.1
years). All patients underwent parathyroidectomy for excision of parathyroid
adenoma. MEASUREMENTS: BMDs of two cancellous bone-rich sites (L2-L4 lumbar spine
and ultra-distal end of the radius, RUD) and one cortical bone-rich site (distal
third of the radius, R33%) were measured using dual energy X-ray absorptiometry,
before, and 3, 6 and 12 months after surgery. Serum intact PTH, intact
osteocalcin, bone type alkaline phosphatase (b-ALP), alkaline phosphatase,
calcium, and urinary deoxypyridinoline (Dpd) were measured before, and 1 and 3
days, and 1, 2, 3, 4, 6, 8, 12, and 24 weeks after surgery. RESULTS:
Parathyroidectomy resulted in a significant increase in BMDs of L2-L4 and RUD at
3 months postoperatively. Urinary Dpd levels decreased within a few days after
surgery, while b-ALP and osteocalcin decreased more slowly throughout the first
few months after surgery. The ratio of osteocalcin/Dpd at 1 week after surgery
correlated significantly with the percentage change in BMD of L2-L4 at 3 and 6
months after surgery. The ratio of osteocalcin/Dpd at 2 weeks correlated
significantly with the percentage change in BMD of L2-L4 at 3, 6 and 12 months
after surgery. The preoperative values of osteocalcin, b-ALP, PTH and calcium
were positively correlated with the change in BMD of RUD at 3 months and L2-L4 at
12 months, RUD at 6 months, RUD at 3 months and L2-L4 at 12 months, respectively.
CONCLUSIONS: In primary hyperparathyroidism patients, the major increase in bone
mineral density following parathyroidectomy occurs within 3 months.
Parathyroidectomy resulted in a marked increase in bone mineral density of
cancellous bones compared to that of cortical bones. The early increase in bone
mineral density was due to a preferential activation of bone formation over bone
resorption as evidenced by changes in bone metabolic markers. Our results also
showed that the preoperative levels of bone metabolic markers may predict the
gain in bone mineral density after parathyroidectomy.
PMID- 10671949
TI - Consequences of vitamin D receptor gene polymorphisms for growth inhibition of
cultured human peripheral blood mononuclear cells by 1, 25-dihydroxyvitamin D3.
AB - OBJECTIVE: In the vitamin D receptor (VDR) gene a BsmI restriction fragment
length polymorphism (RFLP) in intron 8 and a translational start-site
polymorphism, identified as a FokI RFLP, have been described. Crucial for a
proper interpretation of these polymorphisms in association studies is the
knowledge whether they have direct consequences for 1,25-(OH)2D3 action at
cellular level. The present study was designed to assess functional significance
of the FokI and BsmI VDR gene polymorphisms in peripheral blood mononuclear cells
(PBMC) with a natural occurring VDR genotype for cell growth inhibition by 1,25
(OH)2D3. DESIGN: PBMC of women were isolated, VDR genotyped and in vitro
inhibition by 1,25-(OH)2D3 of Phytohemagglutinin (PHA)-stimulated growth of PBMC
was examined in relation to VDR genotype. RESULTS: PHA-stimulated growth and
maximal growth inhibition were independent of VDR genotype. However, the FF
genotype had a significant lower ED50 than the Ff genotype corresponding to an
allele dose effect of 0.32 nM per f allele copy (P = 0.0036). For BsmI genotypes
no differences in ED50 were observed. CONCLUSION: The present study demonstrates
for the first time in cells with a natural VDR genotype a direct functional
consequence of the VDR gene translational start-site polymorphism for the action
of 1,25-(OH)2D3. Especially under conditions of vitamin D insufficiency these
findings might have clinical implications.
PMID- 10671950
TI - Nasogastric feeding enhances nutritional status in paediatric liver disease but
does not alter circulating levels of IGF-I and IGF binding proteins.
AB - OBJECTIVE: Complications of childhood cirrhosis include abnormal growth and
malnutrition, associated with abnormalities in circulating IGFs and IGFBPs.
Controlled studies suggest that intensive enteral feeding enhances nutritional
status. The aim was to ascertain whether nasogastric feeding improves nutritional
status in clinical practice and to assess the effect of feeding on serum IGF-I
and IGFBPs. PATIENTS: Thirty-three children (median age 0.6 years) with biliary
atresia and failure to thrive who were treated with nasogastric feeding.
MEASUREMENTS: Height, weight and triceps skin fold thickness were measured prior
to feeding and regularly for 1 year or until feeding was stopped. Serum IGF-I and
IGFBPs were measured by immunoassay at the same intervals. RESULTS: The median
duration of feeding was 3.7 months. Twenty-two stopped feeding after liver
transplantation, while 10 stopped electively and 1 boy died. Before feeding, the
children were losing weight and height centile. Triceps skin fold thickness,
weight and height SD scores improved with feeding. Baseline serum IGF-I and IGFBP
3 were low, while IGFBP-1 and IGFBP-2 were raised. IGF-I and IGFBP-1 did not
change with feeding. IGFBP-2 fell and reached a nadir by 3 months, while IGFBP-3
rose temporarily for 4-6 weeks. CONCLUSIONS: Nasogastric feeding improves body
composition in paediatric liver disease but circulating IGF-I and IGFBPs remain
abnormal and do not play a major role in mediating these changes. This does not
exclude a paracrine or autocrine effect of IGF-I.
PMID- 10671951
TI - Raloxifene reduces atherosclerosis: studies of optimized raloxifene doses in
ovariectomized, cholesterol-fed rabbits.
AB - OBJECTIVE: We have previously shown that raloxifene, a selective oestrogen
receptor modulator, 35 mg/day inhibits atherosclerosis in ovariectomized,
cholesterol-fed rabbits. This effect was only partial as compared to 17beta
oestradiol 4 mg/day; however, plasma raloxifene concentrations were low relative
to those obtained in raloxifene-treated women. We therefore investigate the
effects of raloxifene at higher doses. DESIGN: The study on atherosclerosis in
ovariectomized, cholesterol-fed rabbits (n = 80) compared raloxifene 70 mg/day
and 210 mg/day to 17beta-oestradiol 4 mg/day and placebo. RESULTS: After 48 weeks
of therapy, the aortic cholesterol content in the 70 mg/day and 210 mg/day
raloxifene treatment groups were 471 +/- 56 nmol/mg protein and 456 +/- 56
nmol/mg protein, respectively. This was significantly less than in the placebo
group (654 +/- 69 nmol/mg protein; P < 0.05). In the oestrogen-treated group, the
aortic cholesterol content was 357 +/- 62 nmol/mg protein (P < 0.01 as compared
to placebo). Differences in serum lipids between the treatment groups could only
partly explain the effect on aortic cholesterol content, indicating that
additional anti-atherogenic mechanisms may contribute to the decrease in aortic
atherosclerosis. This anti-atherosclerotic activity of raloxifene was observed at
plasma concentrations comparable to those in postmenopausal women during
raloxifene treatment. CONCLUSIONS: We conclude that clinically relevant
raloxifene treatment inhibits aortic atherosclerosis in ovariectomized,
cholesterol-fed rabbits.
PMID- 10671952
TI - GIP-dependent adrenal Cushing's syndrome with incomplete suppression of ACTH.
AB - ACTH-independent Cushing's syndrome may be due to the development of ectopic
hormone receptors in adrenal tissue. Thus, in food-dependent Cushing's syndrome
the adrenals aberrantly express receptors for gastric inhibitory polypeptide
(GIP). We present the case of a 60-year-old woman with food-dependent Cushing's
syndrome whose cortisol levels increased after stimulation with CRH. In this
patient with Cushing's syndrome the finding of low basal plasma cortisol levels
in the late night and early morning as well as a paradoxical rise of plasma
cortisol during a 7-h infusion with dexamethasone (carried out without any
restriction in food intake), suggested that cortisol production was stimulated at
times of food intake. Hourly measurements of plasma cortisol for 48 h revealed
prominent meal-related peaks. A plasma cortisol response, elicited by oral
glucose administration, could be prevented by octreotide. Plasma ACTH was low or
undetectable. CRH administration was followed by a ACTH response from 3 to 16
ng/l and a plasma cortisol response from 230 to 680 nmol/l. Octreotide treatment
for nearly five months induced a partial clinical and biochemical remission.
Total bilateral adrenalectomy was performed. The left adrenal was grossly
enlarged (7 x 5.5 x 4 cm) and the right adrenal was slightly enlarged (6 x 4 x
1.8 cm). Microscopy revealed bilateral nodular hyperplasia. Cell suspensions of
adrenal tissue from the patient did respond in a dose-dependent fashion to
stimulation with GIP and were very sensitive to stimulation with synthetic ACTH1
24. However, CRH had no significant effect on cortisol production in vitro. Using
RT-PCR amplification and cDNA hybridization, GIP receptor was found to be
overexpressed in the left and right adrenal tissues from this patient as compared
to adrenal tissues from a normal individual or from non GIP-dependent adrenal
Cushing's syndrome. There was no evidence of presence of adrenal CRH receptors.
Thus, in this patient with food-dependent Cushing's syndrome, the CRH-induced
plasma ACTH and cortisol response is probably mediated by an incomplete
suppression of the HPA axis as a result of the intermittent food-dependent nature
of Cushing's syndrome.
PMID- 10671953
TI - Complete resolution of protease inhibitor induced diabetes mellitus.
PMID- 10671954
TI - Metformin and polycystic ovary syndrome.
PMID- 10671955
TI - Metformin and ovarian steroidogenesis in PCOS women.
PMID- 10671956
TI - Metformin and polycystic ovary syndrome
PMID- 10671957
TI - Carbenoxolone effects in congenital adrenal hyperplasia.
PMID- 10671958
TI - Carbenoxolone effects in congenital adrenal hyperplasia
PMID- 10671959
TI - Screening for diabetes in obese women: comparison between the New American
Diabetes Association and WHO criteria.
PMID- 10671960
TI - Interferon-alpha therapy for melanoma.
AB - Although surgery may be curative in early malignant melanoma, its effect on
survival lessens with each succeeding stage of the disease. A wide variety of
immunological strategies have therefore been used to improve the prognosis of
patients with malignant melanoma, but adjuvant therapy with interferon (IFN)
alpha is the only treatment to show a therapeutic benefit in randomized
controlled studies. The current data indicates that where IFN-alpha is used at
low dose, its main effect is on disease-free survival, whereas high-dose regimens
may improve overall survival as well. This paper will review the published data
on IFN-alpha therapy in patients with intermediate and high-risk melanoma and
explore future avenues for managing patients with this difficult disease.
PMID- 10671961
TI - Treatment options for giant congenital naevi.
AB - Giant congenital naevi (GCN) are disfiguring, potentially malignant pigmented
naevi present at birth. The naevus cells in GCN are found throughout the dermis
and sometimes penetrate the subcutaneous septa. It is claimed that superficial,
more heavily pigmented and biologically different naevus cells reside in the
upper dermis. Partial removal of these superficial naevus cells by dermabrasion,
laser therapy, curettage or shave excision is less traumatic than excision
surgery and produces an acceptable cosmetic result. However, none of these
techniques or excision of GCN to superficial fat completely removes the risk of
malignant transformation.
PMID- 10671962
TI - An evaluation of educational requirements for community nurses treating
dermatological patients.
AB - In a questionnaire to community nurses treating dermatological patients, 14 out
of 69 (20%) either treated children or gave advice to parents regarding childhood
eczema, 35 (51%) treated adult eczema, 11 (16%) treated psoriasis, 55 (80%)
treated leg ulcers, and 30 (43%) treated other dermatological problems. Specific
questions regarding confidence to treat or educate were analysed in relation to
the tasks being performed. All but 15% (8/55) treating leg ulcers were confident
about their ability to apply four-layer bandaging. However, 8 out of 11 (72%)
respondents treating psoriasis were not confident about their ability to treat
scalp scaling, 11 out of 14 (79%) of those treating childhood eczema were not
confident about applying body suiting, and 26 out of 36 (72%) of those treating
eczema (any age), were not confident about ability to recognize infection as a
cause or complication of dermatoses. The favoured educational modalities were
visits to the local dermatology department (60/69, 87%), availability of a
dermatology Nurse Practitioner or Liaison Nurse, or access to a hospital nurse
run dermatology clinic (both 44/69, 63%), or attendance at courses (36/69, 52%).
Community nurses have an important role in treating and educating patients who
may not require or be able to attend hospitals for treatment; they will achieve
this best by provision of relevant locally based education, with allocation of
adequate study time.
PMID- 10671963
TI - Chloroxylenol and zinc oxide containing cream (Nels cream) vs. 5% benzoyl
peroxide cream in the treatment of acne vulgaris. A double-blind, randomized,
controlled trial.
AB - Forty-one subjects completed a double-blind controlled randomized study comparing
the following: (i) Nels cream (containing chloroxylenol and zinc oxide); (ii) 5%
benzoyl peroxide cream; and (iii) the vehicle of the Nels cream. Patients applied
the medications twice daily for 8 weeks. At the end of the test period there was
no significant difference in the reduction of inflammatory and noninflammatory
lesion counts achieved by Nels cream and benzoyl peroxide. Both creams proved
superior to the vehicle. Efficacy grading by subjects and investigators showed no
significant difference between Nels cream and benzoyl peroxide. However, side
effects such as peeling and dryness caused by the treatment were significantly
less in the Nels cream group.
PMID- 10671964
TI - Yellow nail syndrome: the nail that grows half as fast grows twice as thick.
AB - We report a case of a 51-year-old man with yellow nail syndrome (YNS).1 During a
23-week period of study, the dynamics of thumbnail growth were compared between
one affected thumb and the normal contralateral thumb. Longitudinal nail growth
was normal (0.46 mm/week) in the normal thumb and double that of the affected
thumb (0.23 mm/week). Thickness of nail at the free edge in the affected thumb
(0.97 mm) was twice that of the normal thumb (0.57 mm). Within the nail plate in
the dorso-ventral axis there were 50% more cells in the affected thumb (358) in
comparison with the contralateral control (242). This case illustrates that rate
of longitudinal growth does not necessarily reflect nail plate production.
PMID- 10671965
TI - Pulmonary toxicity in a patient with psoriasis receiving methotrexate therapy.
AB - We report a 34-year-old woman with psoriasis who developed shortness of breath
during methotrexate therapy. Methotrexate had been started 4 months earlier and
the patient had ingested a cumulative dose of 232 mg. Pulmonary function tests
showed a reduction in transfer factor to 76% of predicted. Methotrexate was
stopped and her symptoms rapidly resolved. Pulmonary function tests deteriorated
further despite stopping methotrexate but with no recurrence of symptoms with a
transfer factor of 66% of predicted 2 months later. At 5 months after stopping
methotrexate the patient remained well and pulmonary function had improved with a
transfer factor of 79% of predicted. Pulmonary toxicity is a rare but important
adverse effect of methotrexate therapy in patients with psoriasis.
PMID- 10671966
TI - Welding and non-melanoma skin cancer.
AB - This paper reports on five cases of nonmelanoma skin cancer (NMSC) occurring in
welders, an occupation in which there is potential for intense exposure to
nonsolar ultraviolet irradiation. The status of ultraviolet light as the major
aetiological factor in NMSC is well established, and in the great majority of
cases solar irradiation is the source. The possible role of nonsolar sources of
ultraviolet irradiation should not be overlooked.
PMID- 10671967
TI - Protean manifestations of lipoid proteinosis in a 16-year-old boy.
AB - We report a 16-year-old Japanese male with lipoid proteinosis showing various
skin manifestations. The patient was born to nonconsanguineous parents and none
of his relatives was similarly affected. The patient suffered from a hoarse voice
and refractory temporal epilepsy from early childhood. Computed tomography
scanning of the brain showed bilateral calcification in the temporal lobes, a
characteristic feature of lipoid proteinosis. On physical examination, various
skin manifestations, including papules and haemorrhagic blisters, acne-like scars
at sites of minor trauma or friction, and beads of small papules along the free
margins of the eyelids were noted. A skin biopsy showed deposits of homogeneous
hyaline-like material, positive on periodic acid-Schiff staining, throughout the
dermis, particularly around small blood vessels. It is noteworthy that a range of
characteristic skin lesions can be present in a patient with lipoid proteinosis
even with mild systemic involvement.
PMID- 10671968
TI - Renal angiogram abnormalities in a case of cutaneous polyarteritis nodosa.
AB - The existence of a limited cutaneous form of polyarteritis nodosa remains
controversial. It has been characterized and contrasted with systemic
polyarteritis nodosa by running a chronic course and having a relatively good
long-term prognosis. We report a case with clinical features fitting the criteria
for cutaneous polyarteritis nodosa but also showing evidence of associated renal
aneurysms on selective visceral angiography. These findings suggest that the
differentiation between systemic and cutaneous forms might be an
oversimplification and we discuss the relationship between the two forms.
PMID- 10671969
TI - Oesophageal lichen planus.
AB - We present a case of lichen planus affecting the oesophagus of an 80-year-old
woman. Symptomatically, the lesions manifested themselves as dysphagia requiring
repeated oesophageal dilatations. The patient was unable to tolerate several
conventional treatments and so pulsed methylprednisolone was given with some
beneficial short-term effects. Due to potential for malignant change in lichen
planus of the mucous membranes it is important to remember this complication and
investigate patients with oesophageal symptoms.
PMID- 10671970
TI - Combined cutaneous hamartoma encompassing benign melanocytic naevus, vellus hair
cyst and epidermoid cyst.
AB - We describe a combined cutaneous hamartoma in a 57-year-old man, which comprised
a vellus hair cyst, an epidermoid cyst and an intradermal melanocytic naevus in a
single facial tumour. The vellus hair cyst was filled with keratinous material
with unusual slit-like lacunae. While numerous cases of epidermoid cyst have been
reported in association with an intradermal melanocytic naevus, our case is a
rare example of a lesion combining several hamartomatous elements.
PMID- 10671971
TI - Epidermodysplasia verruciformis: association with isolated IgM deficiency and
response to treatment with acitretin.
AB - We describe a 25-year-old woman, who had extensive, large viral warts consistent
with epidermodysplasia verruciformis (EV) since she was 6-year-old. Laboratory
studies revealed an isolated IgM-deficiency, but the patient demonstrated no
other abnormalities. She was treated with oral acitretin (0.5-1 mg/kg/day) for
six months and her skin lesions improved slightly. However, after discontinuing
the treatment, the lesions came back but she declined further treatment.
PMID- 10671972
TI - Association of multiple familial cutaneous leiomyoma with a uterine symplastic
leiomyoma.
AB - We describe a patient who has familial cutaneous leiomyoma in association with a
symplastic uterine leiomyoma. This association has not been described previously.
PMID- 10671973
TI - Facial cutaneous tuberculosis: an unusual presentation.
AB - Periocular cutaneous tuberculosis is a rare occurrence. We describe a 75-year-old
Caucasian woman with tuberculosis of the left periocular region which responded
completely to standard antituberculosis therapy. We hypothesize this unusual
presentation may be due to minor trauma followed by inoculation.
PMID- 10671974
TI - Phakomatosis pigmentovascularis IIb with renal anomaly.
AB - Phakomatosis pigmentovascularis (PPV) is a rare congenital naevoid syndrome; most
case reports originate in Japan. The major clinical manifestations consist of
coexisting extensive naevus flammeus and pigmentary naevus with or without
systemic involvement. We report an 8-year-old Taiwanese boy, who was born with
extensive naevus flammeus and other anomalies comprising persistent aberrant
Mongolian spot-like pigmentary patches, leg-length discrepancy, pelvic obliquity,
scoliosis and bilateral melanosis oculi bulbi. Further investigation also
revealed agenesis of the right kidney. The cutaneous lesions remained unchanged
over a 3-year follow-up period. Within the classification of PPV, this boy's
disorder represents an example of PPV IIb. Right kidney agenesis, which has never
been observed in PPV, may be an incidental finding.
PMID- 10671975
TI - Subcutaneous sarcoidosis associated with vitiligo, pernicious anaemia and
autoimmune thyroiditis.
AB - We report a patient with pernicious anaemia, primary autoimmune hypothyroidism
and vitiligo, who presented with subcutaneous nodules. Histopathology of the
nodules revealed noncaseating granulomas, consistent with a diagnosis of
sarcoidosis. Mild pulmonary sarcoid was also detected. Although an association
between sarcoidosis and other autoimmune diseases is well-recognized, the
presence of the particular autoimmune diseases in our patient and the involvement
of subcutaneous fat in the sarcoidal inflammation, appears to represent a most
unusual clinicopathological combination.
PMID- 10671976
TI - Bacterial superantigens and inflammatory skin diseases.
AB - Bacteria seem to play an important role in the induction and maintenance of
inflammatory skin diseases such as psoriasis and atopic dermatitis. Toxins from
bacteria including Streptococcus and Staphylococcus aureus, have been shown to
function as a new type of allergen termed 'superantigen'. Superantigens bypass
the normal control of T-cell activation and activate all T-cell clones bearing
certain types of variable chain on the T-cell receptor: this leads to vigorous T
cell activation and cytokine release. These bacterial superantigens may be
involved in induction and aggravation of inflammatory skin diseases. Guttate
psoriasis is often preceded by a streptococcal throat infection and T cells
specific for streptococcal superantigens have been identified in the skin of
patients. The skin of patients with atopic dermatitis is often colonized with
superantigen-releasing Staph. aureus, and application of a staphylococcal
superantigen to human skin induces an eczematoid reaction.
PMID- 10671977
TI - Population-based surveys on the frequency of common skin diseases in adults--is
there a risk of response bias?
AB - Population-based surveys on the frequency of common skin diseases are important
in determining the health needs of a community. As they rely on voluntary
presentation, there is a risk of response bias which may compromise the quality
of the data obtained. The aim was to determine in what way and to what degree
response bias may occur in a population-based survey on the frequency of common
skin diseases in adults. A follow-up study was conducted on 1043 out of 2500
adults who did not attend for examination as part of a randomized population
based survey on the frequency of common skin diseases amongst adults in
Maryborough, Central Victoria, Australia. Nonrespondents were more likely to be
at the extremes of age, retired, unemployed and less likely to report that they
had a history of skin disease than the respondents. Subsequent examination of a
sample of the nonrespondents revealed they were more likely to have skin cancers
and Campbell de Morgan angiomas than the respondents. These differences cannot be
fully explained on the basis of an age-related response bias alone. Response bias
is a risk in population-based surveys of common skin diseases which rely on
voluntary presentation. Some attempt should be made to sample the nonrespondents
in these surveys to determine the nature and extent of any bias and to adjust for
it, if necessary.
PMID- 10671978
TI - Evaluation of a contact allergy clinic.
AB - This study aims to assess the value of patch testing in a specialist contact
allergy clinic as compared to testing carried out by general dermatologist for
the diagnosis of contact allergy. One hundred consecutive patients referred for
patch testing were tested to the European standard and specialized series. A
comparison was made between patch tests read and interpreted by a consultant
dermatologist with an interest in contact allergic dermatitis and by an
experienced registrar who had not yet received any formalized specialized
training. Results of testing with additional allergens acquired following the
establishment of the specialist clinic were examined. In addition patients with a
hand problem and/or symptoms suggestive of contact urticaria underwent skin prick
testing. There was a variation in patch test reading and interpretation between
the consultant and registrar in 10 patients. Patch testing using allergens from
the additional series revealed additional relevant contact allergies in 19
patients. In 14 patients, allergies would have been missed by a limited
additional series. Contact urticaria was detected in seven patients. This study
has confirmed the value of a specialist contact clinic in the diagnosis of
contact allergy. The importance of formalized training in patch test reading and
interpretation, testing with additional series and prick testing for the
diagnosis of contact urticaria are highlighted.
PMID- 10671979
TI - Two type XVII collagen (BP180) mRNA transcripts in human keratinocytes: a long
and a short form.
AB - We have analysed BP180 mRNA expression in normal human keratinocytes. Here we
report the presence in normal keratinocytes of two COL17A1 transcripts which
differ by 0.6 kb in length. Both mRNAs hybridized on Northern blot with probes
directed to sequences encoding intracellular and extracellular fragments of
BP180. By BLAST homology search alignments we extended the 3' untranslated region
(3'UTR) of the known BP180 mRNA sequence by 877 bases to completion. Three of 20
cDNAs identified by BLAST searches contained a 610 bp deletion in this new 3'UTR
sequence. Northern blot analysis with a probe complementary to this deleted
sequence showed binding only to the larger mRNA. The deletion of 610 nucleotides
in the smaller mRNA was verified by reverse transcription-PCR and sequencing.
Genomic PCR showed the new sequence to be an extension of exon 56 of the COL17A1
gene which suggests that the second mRNA is generated by differential splicing.
In normal keratinocytes the level of the smaller transcript was 5-15% of that of
the larger transcript whereas in a squamous cell carcinoma cell line this ratio
was reversed, the smaller mRNA being three times more abundant than the larger
mRNA. The biological significance of this newly identified transcript in protein
synthesis and tissue expression or in cell differentiation, proliferation or
adhesion is as yet unknown.
PMID- 10671980
TI - A 20-year epidemiological study of cutaneous melanoma in the Rijeka district of
Croatia.
AB - A retrospective study was made of the incidence of cutaneous melanoma among the
population of the district of Rijeka (Croatia) during the period 1977-96. A total
of 397 patients with cutaneous melanoma was documented during this period. Over
the 20-year period the incidence of the tumour increased, the mean annual rate
being 4. 8 (4.0 in males and 5.4 in females) in the first 10-year period and 7.16
in the second (7.1 in males and 7.3 in females). The number of registered cases
in males and females was almost identical (1 : 1.05). The number of melanoma
cases increased with age in both sexes, whereas it was rare in children. The most
affected anatomical location was the trunk in males and the lower limbs in
females. The results indicate the need for active prevention and educational
programmes in this population.
PMID- 10671981
TI - Choosing a dermatological hero for the millennium. Erasmus Wilson (1809-1884).
PMID- 10671982
TI - Erasmus Wilson (1809-1884).
PMID- 10671983
TI - Choosing a dermatological hero for the millennium. Robert Willan (1757-1812).
PMID- 10671984
TI - Choosing a dermatological hero for the millennium. Hippocrates of Cos (460-377
BC).
PMID- 10671985
TI - Choosing a dermatological hero for the millennium. Daniel Turner (1667-1741).
PMID- 10671986
TI - Choosing a dermatological hero for the millennium. Jean-Louis Alibert (1768
1837).
PMID- 10671987
TI - Choosing a dermatological hero for the millennium. William Shakespeare (1564
1616).
PMID- 10671988
TI - Autologous blood transfusion.
PMID- 10671989
TI - Lifetime treatment costs of beta-thalassaemia major.
AB - Beta-thalassaemia major is a serious genetic disorder, which results in a
considerable increase in both acute and chronic morbidity, and mortality.
Although beta-thalassaemia major is a rare disease affecting approximately 600
people in the UK, treatment is intensive and predictions of the costs incurred
may aid health care planning. In this report, the cost to the health service of
providing treatment services for beta-thalassaemia major patients, over the
course of a lifetime, is calculated in order to assist resource allocation
decisions. A cost model was developed, incorporating data from disparate sources.
The undiscounted lifetime cost of treating a beta-thalassaemia major patient was
estimated to be pound 803,002, although when the costs were discounted at a rate
of 6%, the lifetime cost was reduced to pound 219,068. Within sensitivity
analyses, the discounted cost ranged from approximately pound 188,000 to pound
226,000. This report may act as a guide to those involved in the planning of
health care provision with regard to the resources required to treat beta
thalassaemia major patients. Such information may also be incorporated into the
decision-making process for the provision of antenatal screening programmes for
beta-thalassaemia major.
PMID- 10671990
TI - Highly fluorescent reticulocyte count predicts haemopoietic recovery after
immunosuppression for severe aplastic anaemia.
AB - Highly fluorescent reticulocyte (HFR) counts are the most reliable and sensitive
index of haemopoietic recovery after bone marrow or peripheral blood stem cell
transplantation. We report the behaviour of HFRs during haemopoietic recovery in
two patients who were affected by severe aplastic anaemia (SAA) and treated with
horse antithymocyte globulin (ATG), cyclosporin A (CsA) and granulocyte colony
stimulating factor (G-CSF). A HFR value > 5% of the total reticulocyte count, a
reticulocyte count > 30 x 10(9)/l, and a polymorphonuclear (PMN) count > 0.5 x
10(9)/l were found after 9 and 8, 20 and 46, and 16 and 22 days, respectively,
after the end of ATG. HFR recovery to > 5% anticipated the rise of PMN > 0.5 x
10(9)/l by at least 7 and 14 days, respectively. Thus, HFR evaluation could be
used as a reliable and early marker of response to immunosuppression in severe
aplastic anaemia.
PMID- 10671991
TI - Microvolume fluorimetry for the determination of absolute CD4 and CD8 lymphocyte
counts in patients with HIV: a comparative evaluation.
AB - This study compared CD4 and CD8 lymphocyte counts obtained by microvolume
fluorimetry (MVF) with those derived by flow cytometry (FC). Samples from 192
patients with known or suspected HIV were analysed, and the distribution of CD4
counts for these samples ranged from 0 and 1,279/microl, with 142/192 (74%) of
the samples having CD4 values of less than 400/microl. Good agreement between FC
and MVF CD4 counts was found (MVF = 0.98 x FC + 7.30) although there was a minor
constant inter-method bias of approximately +7 cells/microl for the MVF data. For
CD8 counts there was a constant bias between the two methods of approximately +23
cells/microl for FC. Most outliers were associated with higher FC CD8 counts.
Supplementary analyses showed a high level of agreement between FC and MVF
methods for the CD4:CD8 ratios (MVF = 0.98 x FC). This suggests that observed
discrepancies between FC and MVF methods were almost certainly a result of the
influence of the absolute lymphocyte counts obtained from the haematology
analyser. The results confirm that the IMAGN 2000 microvolume fluorimeter system
can be used as an alternative to conventional flow cytometry for the enumeration
of CD4 and CD8 counts.
PMID- 10671992
TI - Wiskott Aldrich syndrome presenting as congenital thrombocytopenia.
AB - The application of molecular biology to haematology has provided the opportunity
to revisit previous diagnoses, many of which can now be redefined. This report is
on a local family previously diagnosed and published as having X-linked
thrombocytopenia in 1974, and shows how the application of molecular screening
has confirmed the true diagnosis of Wiskott Aldrich syndrome.
PMID- 10671993
TI - Factor V Leiden and allogeneic bone marrow transplantation: chimerism as a
confounding factor in genetic test interpretation.
AB - Factor V Leiden is one of the most common genetic conditions predisposing to
venous thrombosis. Diagnosis is currently made by plasma activity assay for
activated protein C (APC) resistance or polymerase chain reaction (PCR)-based DNA
assay. The occurrence of factor V Leiden is reported in a patient affected by
acute myeloid leukaemia submitted to allogeneic bone marrow transplantation from
an HLA identical sister. The donor was not affected by the factor V mutation. The
patient did not develop thrombosis during induction and consolidation
chemotherapy and the post-transplantation course was not complicated by
thrombosis or veno-occlusive disease. At engraftment, PCR analysis showed the
disappearance of factor V Leiden. Genetic tests on DNA after allogeneic marrow
transplantation should be carefully interpreted as a result of donor chimerism.
PMID- 10671994
TI - Paediatric myelodysplastic syndrome (MDS) and juvenile chronic myelogenous
leukaemia (JCML) detected by cytogenetic and FISH techniques.
AB - This report presents two rare cases, one of paediatric myelodysplastic syndrome
(MDS) and the other juvenile chronic myeloid leukaemia (jCML). In the first case,
there were clinical and biological features of MDS-refractory anaemia with excess
blasts (RAEB). The bone marrow (BM) karyotype demonstrated a monosomy 7 which was
confirmed by fluorescence in situ hybridization (FISH). In addition, FISH
analysis showed that an alpha-satellite DNA sequence had been transferred from
chromosomes 13/21 to one homologue of chromosomes 22. The BCR-ABL rearrangement
was negative. In the second case, at diagnosis, the karyotype was 46,XX. FISH
analysis with the simultaneous and individual application of abl and bcr probes
for chromosome 9 and 22, respectively, revealed the presence of the BCR-ABL
rearrangement in addition to an extra ABL sequence locating chromosome 20. A
clone that was BCR-ABL gene rearrangement negative but with an extra ABL DNA
sequence on chromsome 20, and another clone that was BCR-ABL gene rearrangement
negative were detected by DC-FISH and uni-colour (UC-) FISH analysis. No monosomy
7 was detected by conventional cytogenetic or FISH analyses.
PMID- 10671995
TI - Delayed haemolytic transfusion reaction caused by anti-M antibody in a patient
receiving interleukin-2 and interferon for metastatic renal cell cancer.
AB - Anti-M is usually a naturally occurring cold-reactive immunoglobulin M (IgM)
antibody, often with an immunoglobulin G (IgG) component, and is seldom
implicated in delayed haemolytic transfusion reactions (DHTR). However, cases
have been reported. In the majority, a DHTR is not suspected until further blood
is requested and a new antibody is detected on pretransfusion testing. We
describe the case of a young man receiving therapy with interleukin-2 (IL-2) and
interferon-alpha (IFN-alpha) for metastatic renal cell cancer who developed a
clinically suspected DHTR that was confirmed serologically to be caused by anti
M, reactive at 37 degrees C. We discuss the possible role of his biochemotherapy
in the development of the DHTR.
PMID- 10671996
TI - Sickle cell disease and nitrous oxide-induced neuropathy.
AB - We report three cases of peripheral neuropathy in patients with sickle cell
disease. All had a history of frequent painful crises and regular attendance at
our Accident and Emergency department where nitrous oxide analgesia was
administered for prolonged periods. All three patients (one male and two females)
presented with difficulty in walking associated with paraesthesiae, and
neurological examination revealed signs compatible with a peripheral sensorimotor
neuropathy, later confirmed by nerve conduction studies. Serum vitamin B12 levels
were mildly reduced in two patients and very low in one patient (< 10 ng/l).
Haemoglobin levels in all the patients were unchanged compared with their steady
state levels but one had developed a macrocytosis (103 fl). Schilling tests were
normal in two patients, and two patients had negative gastric parietal
antibodies. All three patients were given intramuscular vitamin B12 in addition
to avoiding further exposure to nitrous oxide, and their neurological symptoms
improved completely. As nitrous oxide is known to cause a neuropathy similar to
that seen in pernicious anaemia, we postulate that nitrous oxide analgesia
combined with low B12 levels was the cause of the marked neuropathy in these
patients. As a result of our observations and the probable association, we now do
not use nitrous oxide analgesia in the management of patients with sickle cell
disease.
PMID- 10671997
TI - Systemic lupus erythematosus presenting with haemorrhagic manifestation.
AB - A 26-year-old female presented with an episode of severe mucus membrane bleeding.
Investigations revealed prolonged prothrombin time (PT), and partial
thromboplastin time (PTT), normal thrombin time (TT) and reptilase time,
thrombocytopenia, a positive test for lupus anticoagulant (LA), as well as anti
cardiolipin antibodies (ACL). A toxicology screen for toxic drugs and coumadin
was negative. Coagulation factor assays revealed low levels for factor II and
XII. Low level inhibitor to factor II was demonstrated. Patient had a negative
VDRL test and positive anti-nuclear antibodies (ANA). The diagnosis of acquired
hypoprothrombinaemia secondary to circulating inhibitor induced by LA was made,
and then the patient was started on prednisone, which led to cessation of the
bleeding and normalization of PT and PTT, as well as an increase of factor II and
factor XII levels. A few months later, the patient developed arthralgia and
alopecia, and antibodies against double-stranded DNA were detected, and the
diagnosis of systemic lupus erythematosis (SLE) was confirmed. The patient
continued to have mild prolongation of PT and PTT while on a low dose of
prednisone, but she had no bleeding symptoms. A computed tomography scan of the
brain was carried out for unexplained central nervous system (CNS) symptoms, and
it revealed mild hydrocephalus, which was thought to be part of the CNS
manifestations of SLE. It was concluded that patients with SLE may present with
haemostatic defects that are a result of either platelet-related causes
(quantitative or qualitative) or coagulation factor deficiency secondary to
circulating inhibitor, or both, in the absence of other features of SLE which may
appear later.
PMID- 10671998
TI - A change in reaction specificity of sheep liver serine hydroxymethyltransferase.
Induction of NADH oxidation upon mutation of His230 to Tyr.
AB - Both serine hydroxymethyltransferase and aspartate aminotransferase belong to the
alpha-class of pyridoxal-5'-phosphate (pyridoxalP)-dependent enzymes but exhibit
different reaction and substrate specificities. A comparison of the X-ray
structure of these two enzymes reveals that their active sites are nearly
superimposable. In an attempt to change the reaction specificity of serine
hydroxymethyltransferase to a transaminase, His 230 was mutated to Tyr which is
the equivalent residue in aspartate aminotransferase. Surprisingly, the H230Y
mutant was found to catalyze oxidation of NADH in an enzyme concentration
dependent manner instead of utilizing L-aspartate as a substrate. The NADH
oxidation could be linked to oxygen consumption or reduction of
nitrobluetetrazolium. The reaction was inhibited by radical scavengers like
superoxide dismutase and D-mannitol. The Km and kcat values for the reaction of
the enzyme with NADH were 74 microM and 5. 2 x 10-3 s-1, respectively. This
oxidation was not observed with either the wild type serine
hydroxymethyltransferase or H230A, H230F or H230N mutants. Thus, mutation of H230
of sheep liver serine hydroxymethyltransferase to Tyr leads to induction of an
NADH oxidation activity implying that tyrosyl radicals may be mediating the
reaction.
PMID- 10671999
TI - A switch in the direction of the effect of insulin on the partitioning of hepatic
fatty acids for the formation of secreted triacylglycerol occurs in vivo, as
predicted from studies with perfused livers.
AB - The direct effects of insulin on hepatic triacylglycerol secretion are important
because they may determine the degree of postprandial hyperlipidaemia, a known
risk factor for the development of atherosclerotic lesions. Previous work from
this laboratory, conducted on isolated perfused rat livers [Zammit, V.A.,
Lankester, D.J., Brown, A.M. & Park, B.S. (1999) Eur. J. Biochem. 263, 859-864],
has indicated that the effect of insulin on hepatic triacylglycerol secretion is
dependent on the prior physiological state of the donor animals. In this paper,
we demonstrate that a switch in the direction of insulin action on hepatic
partitioning of fatty acyl moieties towards triacylglycerol secretion also occurs
in vivo between the fed, normoinsulinaemic state and the fasted or severely
insulin-deficient states. The partitioning of fatty acids in the liver of awake,
unstressed rats was studied using selective labelling of hepatic fatty acids
during hyperinsulinaemic-euglycaemic clamps achieved through the use of
hepatocyte-targeted liposome-encapsulated insulin preparations. The data show
that, whereas in the fed, normoinsulinaemic state, insulinization of the liver
raises the proportion of fatty acids directed towards secreted triacylglycerol,
in the fasted or insulin-deficient states, insulin inhibits the partitioning of
acyl moieties into secreted triacylglycerol. These data show that observations on
the direction of insulin action on hepatic triacylglycerol secretion obtained
using isolated perfused rat livers are reflected in the effects of the hormone on
hepatic fatty acid partitioning in vivo. They offer an explanation for the
positive relationship between chronic hyperinsulinaemia, hepatic VLDL
triacylglycerol secretion and hypertriglyceridaemia observed previously in
insulin-resistant states.
PMID- 10672000
TI - Regiospecific glycosidase-assisted synthesis of lacto-N-biose I (Galbeta1
3GlcNAc) and 3'-sialyl-lacto-N-biose I (NeuAcalpha2-3Galbeta1-3GlcNAc).
AB - The all-transglycolytic synthesis of lacto-N-biose I (Galbeta1-3GlcNAc) and 3'
sialyl-lacto-N-biose I (NeuAcalpha2-3Galbeta1-3GlcNAc) was performed. The
disaccharide lacto-N-biose I was obtained by use of p-nitrophenyl beta-D
galactopyranoside as the donor, 2-acetamido-2-deoxy-D-glucopyranose as the
acceptor and Xanthomonas manihotis beta-D-galactosidase as the catalyst. The
reaction was shown to be regiospecific, with a high molar yield (about 55%) with
respect to the donor. Lacto-N-biose I obtained by this method was used as the
acceptor for a subsequent enzymatic reaction catalyzed by Trypanosoma cruzi trans
sialidase in which 2'-(4-methylumbellyferyl)-alpha-D-N-acetylneuraminic was used
as the donor of the N-acetylneuraminil moiety. The reaction generated the
product, 3'-sialyl-lacto-N-biose I, regiospecifically and with a molar yield of
about 35%.
PMID- 10672001
TI - Electron transfer rates and equilibrium within cytochrome c oxidase.
AB - Intramolecular electron transfer (ET) between the CuA center and heme a in bovine
cytochrome c oxidase was investigated by pulse radiolysis. CuA, the initial
electron acceptor, was reduced by 1-methyl nicotinamide radicals in a diffusion
controlled reaction, as monitored by absorption changes at 830 nm. After the
initial reduction phase, the 830 nm absorption was partially restored,
corresponding to reoxidation of the CuA center. Concomitantly, the absorption at
445 nm and 605 nm increased, indicating reduction of heme a. The rate constants
for heme a reduction and CuA reoxidation were identical within experimental error
and independent of the enzyme concentration. This demonstrates that a fast
intramolecular electron equilibration is taking place between CuA and heme a. The
rate constants for CuA --> heme a ET and the reverse (heme a --> CuA) process
were found to be 13 000 s-1 and 3700 s-1, respectively, at 25 degrees C and pH
7.4. This corresponds to an equilibrium constant of 3.4 under these conditions.
Thermodynamic and activation parameters of the ET reactions were determined. The
significance of these results, particularly the observed low activation barriers,
are discussed within the framework of the known three-dimensional structure, ET
pathways and reorganization energies.
PMID- 10672002
TI - Insulin stimulates NHE1 activity by sequential activation of phosphatidylinositol
3-kinase and protein kinase C zeta in human erythrocytes.
AB - The signaling cascade linking insulin receptor stimulation to the activation of
Na/H exchanger (NHE) was investigated in human erythrocytes, a simple cell model
expressing the NHE1 isoform and protein kinase C (PKC) alpha and zeta isoforms
only. Our results demonstrate the presence of phosphatidylinositol (PtdIns) 3
kinase in these cells and its activation by insulin. With a similar time-course,
insulin also promoted both the translocation and activation of PKC zeta, but had
no effect on PKC alpha. Inhibition of PtdIns 3-kinase with wortmannin prevented
the activation of PKC zeta by insulin. Stimulation of NHE1 was observed after 10
min of insulin treatment and persisted for at least 60 min. This effect was
totally abolished by wortmannin or GF 109203X, an inhibitor of all PKC isoforms,
but not by Go 6976, a specific inhibitor of conventional and novel PKCs (e.g. PKC
alpha). These data indicate that PKC zeta activation is mediated by a PtdIns 3
kinase-dependent mechanism and that NHE1 stimulation involves the sequential
activation of PtdIns 3-kinase and PKC zeta. In addition, insulin stimulation of
NHE1 occurred without altering the phosphorylation state of the exchanger,
suggesting that the phosphorylation of an ancillary protein by PKC zeta would be
responsible for activation of the transporter.
PMID- 10672003
TI - Regulation of phenobarbital induction of the cytochrome P450 2b9/10 genes in
primary mouse hepatocyte culture. Involvement of calcium- and cAMP-dependent
pathways.
AB - Phenobarbital (PB) has long been known as an inducer of drug-metabolizing enzymes
in liver, but the molecular mechanism underlying this induction is still poorly
understood. Using primary mouse hepatocyte culture, we have investigated the
possible involvement of different regulatory pathways in PB action, by exposing
PB-treated cells to various protein kinase/phosphatase modulators. Our results
showed a negative role of the cAMP-dependent pathway, as treatment with cAMP
dependent protein kinase (PKA) activators (10 microM dibutyryl-cAMP and 50 microM
forskolin) dramatically inhibited PB-induced Cyp2b9/10 mRNA accumulation, whereas
PKA inhibitor potentiated the PB responsiveness of this gene. The cGMP-dependent
protein kinase (PKG) seems to play a positive role as PKG inhibitor reduced the
PB-induced level of Cyp2b9/10 mRNA. We also obtained two lines of evidence for
the involvement of Ca2+ in modulating PB action. Firstly, measurements of
intracellular Fura-2 fluorescence ratio in murine hepatocytes showed that long
term PB incubation (24 and 48 h) led to a significant increase of [Ca2+]i.
Secondly, treatment with an intracellular Ca2+ chelator (BAPTA-AM) nearly
completely abolished PB-induced Cyp2b9/10 expression. Ca2+ thus appeared to
mediate PB action likely via Ca2+/calmodulin-dependent protein kinase II, as
KN62, a specific inhibitor of this enzyme, also dramatically inhibited PB
induction of the Cyp2b9/10 genes.
PMID- 10672004
TI - Transforming growth factor beta induction of insulin gene expression is mediated
by pancreatic and duodenal homeobox gene-1 in rat insulinoma cells.
AB - Although transforming growth factor-beta (TGF-beta) stimulates pancreatic islet
cells to synthesize and secret insulin, the mechanism underlying this effect is
not known. To investigate this question, we examined the insulin promoter
activity focusing on a transcription factor, pancreatic and duodenal homeobox
gene-1 (PDX-1) that binds to the A3 element of the rat insulin promoter. Studies
performed using the rat insulinoma cell line, INS-1 showed that TGF-beta
stimulation of endogenous insulin mRNA expression correlated with increased
activity of a reporter construct containing the insulin promoter. A potential
mechanism for this increase arose from, electrophoretic mobility shift assay
showing that the nuclear extract from TGF-beta treated cells contained higher
levels of A3 binding activity. Western blot analysis confirmed that PDX-1 was
increased in the nuclear extract from INS-1 cells treated with TGF-beta. As
expected, a mutant insulin promoter that lacked the PDX-1 binding site was not
stimulated by TGF-beta. In summary, the results of these studies show that TGF
beta stimulates the transcription of insulin gene and this action is mediated by
the transcription factor, PDX-1.
PMID- 10672005
TI - Activity and stability of a neutral protease from Vibrio sp. (vimelysin) in a
pressure-temperature gradient.
AB - The apparent second-order rate constant of hydrolysis of Fua-Gly-LeuNH2 by
vimelysin, a neutral protease from Vibrio sp. T1800, was measured in a variable
pressure-temperature gradient (0. 1-400 MPa and 5-40 degrees C). The apparent
maximum rate was observed at approximately 15 degrees C and 150-200 MPa; the
pressure-activation ratio (kcat/Km(max)/kcat/Km(0.1 MPa)) was reached about
sevenfold. The pressure dependence of the kcat and Km parameters at constant
temperature (25 degrees C) revealed that the pressure-activation below 200 MPa
was mainly caused by a change in the kcat parameter. The change in the intrinsic
fluorescence intensity of vimelysin was also measured in a pressure-temperature
plane (0.1-400 MPa and -20 to +60 degrees C). The fluorescence intensity was
found to decrease by increasing pressure and temperature, and the isointensity
contours were more or less circular. The tangential lines to the contours at high
temperatures and low to medium pressures seem to have slightly positive slopes,
which was reflected by the higher residual activities left after incubations at
higher temperatures and medium pressure (200 MPa and 50 degrees C) and by the
almost intact secondary structure left after 1 h of incubation at 200 MPa and 40
degrees C, as studied by circular dichroism. These results were compared with the
corresponding results for thermolysin, a moderately thermostable protease from
Bacillus thermoproteolyticus. Apparent differences that might be related to the
temperature adaptations of the respective source microbes are also discussed.
PMID- 10672006
TI - Inhibition of phosphatidylserine synthesis during Jurkat T cell activation. The
phosphatase inhibitor, sodium ortho-vanadate bypasses the CD3/T cell receptor
induced second messenger signaling pathway.
AB - Sodium ortho-vanadate (Na3VO4), an inhibitor of protein tyrosine phosphatase,
induces a rapid (15 min) and strong inhibition of phosphatidylserine synthesis
with an IC50 = 100 microM. The mode of action of Na3VO4 was compared to that of
CD3 mAbs. It was found that Na3VO4 bypasses the major CD3-induced T cell
activation signals including protein tyrosine phosphorylation, p56lck activation
and the generation of second messengers including inositol phosphates and its
subsequent Ca2+ mobilization as well as diacylglycerol production. These facts
were confirmed by using a panel of Jurkat clones that differs by the expression
of either tyrosine kinases involved in the CD3-induced T cell activation pathway
such as p56lck, p72syk and ZAP-70 or some cell surface receptors such as the
CD3/TCR complex or the CD45 phosphatase.
PMID- 10672007
TI - Sulfite and membrane energization induce two different active states of the
Paracoccus denitrificans F0F1-ATPase.
AB - Activation of the latent ATPase activity of inside-out vesicles from plasma
membranes of Paracoccus denitrificans was studied. Several factors were found to
induce activation: heat, membrane energization by succinate oxidation, methanol,
oxyanions (sulfite, phosphate, arsenate, bicarbonate) and limited proteolysis
with trypsin. Among the oxyanions, sulfite induced the higher increase in ATPase
activity. Sulfite functioned as a nonessential activator that slightly modified
the affinity for ATP and increased notoriously the Vmax. There was a competitive
effect between sulfite, bicarbonate and phosphate for ATPase activation; their
similar chemical geometry suggests that these oxyanions have a common binding
site on the enzyme. Dithiothreitol did not affect the ATPase activity. ATPase
activation by sulfite was decreased by uncoupler, enhanced by trypsin and
inhibited by ADP, oligomycin and venturicidin. In contrast, activation induced by
succinate was less sensitive to ADP, oligomycin, venturicidin and trypsin. It is
proposed that the active states induced by sulfite and succinate reflect two
conformations of the enzyme, in which the inhibitory subunit epsilon is
differently exposed to trypsin.
PMID- 10672008
TI - Dual regulatory effects of nitric oxide on plasminogen activator inhibitor type 1
expression in endothelial cells.
AB - In this report we compared the mechanism by which nitric oxide (NO), generated
exogenously and endogenously, affects the plasminogen activator inhibitor type 1
(PAI-1) expression in endothelial cells. For this purpose, we stimulated the
endothelial cell line EA.hy 926 with tumour necrosis factor alpha (TNFalpha) in
the presence of the exogenously NO-releasing donors, sodium nitroprusside (SNP)
and S-nitroso-N-acetylpenicillamine, or regulators of nitric oxide synthase (NOS)
inhibitor N-nitro-L-arginine-methyl ester hydrochloride and substrate L-Arg.
Expression of PAI-1 in EA.hy 926 cells was determined by measuring the level of
mRNA, using relative quantitative reverse transcriptase PCR, and protein, using
ELISA. In addition, we estimated the level of activation of two mitogen-activated
protein kinases (MAPKs), extracellular signal-regulated kinase (ERK1/2) and c-Jun
N-terminal kinase (JNK1/2), in the cells before and after treatment with
TNFalpha, in the presence or absence of NO donors and inhibitors. In contrast to
exogenously released NO that significantly reduced mostly basal PAI-1 expression,
endogenously generated NO by NOS potentiated TNFalpha-induced upregulation of PAI
1 expression. Exogenously and endogenously generated NO causes different effects
on activation of the MAPKs ERK1/2 and JNK1/2. Specifically, the SNP-released NO
activates only ERK1/2, while endogenously generated NO in a pathway induced by
TNFalpha activates both MAPKs. Thus our data indicate that due to different
cellular locations and mechanisms of generation, NO may participate in various
signalling pathways leading to opposite effects on PAI-1 expression in
endothelial cells.
PMID- 10672009
TI - High resolution solution structure of the protein part of Cu7 metallothionein.
AB - The three-dimensional solution structure of the protein part of Cu7
metallothionein (Cu7MT) of Saccharomyces cerevisiae has been attempted by 1H two
dimensional NMR spectroscopy at 800 MHz. The protein part constitutes 53 amino
acids. A total of 1192 NOEs, of which 1048 are meaningful, were used to determine
the solution structure of the first 40 residues, the last 13 residues being
disordered. A family of 30 structures was generated. Root-mean-square deviation
(rmsd) values from the average structure of 0.32 +/- 0.13 A and 0.61 +/- 0.15 A
for backbone and all heavy atoms, respectively, were obtained for the residues 2
40. The ten copper-coordinating cysteine sulfurs and the empty spaces around them
are well defined. The structure of the protein part is similar but not identical
to the available ones of the same holoprotein and of the Ag7 metallothionein, and
is qualitatively superior. If the same metal-sulfur connectivities reported in
the literature from 1H-109Ag heteronuclear multiple quantum coherence
spectroscopy are assumed to hold for the present copper derivative, a peptide
structure is obtained which is again similar, but still not identical, within
indetermination, to that available. The structure of the copper polymetallic
center may well be different from that proposed for the silver derivative, and
indeed a number of different arrangements of the seven copper ions are consistent
with the present highly refined structure of the protein part.
PMID- 10672010
TI - Specific inhibition of barley alpha-amylase 2 by barley alpha-amylase/subtilisin
inhibitor depends on charge interactions and can be conferred to isozyme 1 by
mutation.
AB - alpha-Amylase 2 (AMY2) and alpha-amylase/subtilisin inhibitor (BASI) from barley
bind with Ki = 0.22 nM. AMY2 is a (beta/alpha)8-barrel enzyme and the segment
Leu116-Phe143 in domain B (Val89-Ile152), protruding at beta-strand 3 of the
(beta/alpha)8-barrel, was shown using isozyme hybrids to be crucial for the
specificity of the inhibitor for AMY2. In the AMY2-BASI crystal structure [F.
Vallee, A. Kadziola, Y. Bourne, M. Juy, K. W. Rodenburg, B. Svensson & R. Haser
(1998) Structure 6, 649-659] Arg128AMY2 forms a hydrogen bond with Ser77BASI,
while Asp142AMY2 makes a salt-bridge with Lys140BASI. These two enzyme residues
are substituted by glutamine and asparagine, respectively, to assess their
contribution in binding of the inhibitor. These mutations were performed in the
well-expressed, inhibitor-sensitive hybrid barley alpha-amylase 1 (AMY1)-(1
90)/AMY2-(90-403) with Ki = 0.33 nM, because of poor production of AMY2 in yeast.
In addition Arg128, only found in AMY2, was introduced into an AMY1 context by
the mutation T129R/K130P in the inhibitor-insensitive hybrid AMY1-(1-161)/AMY2
(161-403). The binding energy was reduced by 2.7-3.0 kcal.mol-1 as determined
from Ki after the mutations R128Q and D142N. This corresponds to loss of a
charged interaction between the protein molecules. In contrast, sensitivity to
the inhibitor was gained (Ki = 7 microM) by the mutation T129R/K130P in the
insensitive isozyme hybrid. Charge screening raised Ki 14-20-fold for this latter
mutant, AMY2, and the sensitive isozyme hybrid, but only twofold for the R128Q
and D142N mutants. Thus electrostatic stabilization was effectively introduced
and lost in the different mutant enzyme-inhibitor complexes and rational
engineering using an inhibitor recognition motif to confer binding to the
inhibitor mimicking the natural AMY2-BASI complex.
PMID- 10672011
TI - A class of zinc fingers involved in protein-protein interactions biophysical
characterization of CCHC fingers from fog and U-shaped.
AB - Zinc fingers (ZnFs) are extremely common protein domains. Several classes of ZnFs
are distinguished by the nature and spacing of their zinc-coordinating residues.
While the structure and function of some ZnFs are well characterized, many others
have been identified only through their amino acid sequence. A number of proteins
contain a conserved C-X2-C-X12-H-X1-5-C sequence, which is similar to the spacing
observed for the 'classic' CCHH ZnFs. Although these domains have been implicated
in protein-protein (and not protein-nucleic acid) interactions, nothing is known
about their structure or function at a molecular level. Here, we address this
problem through the expression and biophysical characterization of several CCHC
type zinc fingers from the erythroid transcription factor FOG and the related
Drosophila protein U-shaped. Each of these domains does indeed fold in a zinc
dependent fashion, coordinating the metal in a tetrahedral manner through the
sidechains of one histidine and three cysteine residues, and forming extremely
thermostable structures. Analysis of CD spectra suggests an overall fold similar
to that of the CCHH fingers, and indeed a point mutant of FOG-F1 in which the
final cysteine residue is replaced by histidine remains capable of folding.
However, the CCHC (as opposed to CCHH) motif is a prerequisite for GATA-1 binding
activity, demonstrating that CCHC and CCHH topologies are not interchangeable.
This demonstration that members of a structurally distinct subclass of genuine
zinc finger domains are involved in the mediation of protein-protein interactions
has implications for the prediction of protein function from nucleotide
sequences.
PMID- 10672012
TI - Structural comparison of psychrophilic and mesophilic trypsins. Elucidating the
molecular basis of cold-adaptation.
AB - Structural rationalizations for differences in catalytic efficiency and stability
between mesophilic and cold-adapted trypsins have been suggested from a detailed
comparison of eight trypsin structures. Two trypsins, from Antarctic fish and
Atlantic cod, have been constructed by homology modeling techniques and compared
with six existing X-ray structures of both cold-adapted and mesophilic trypsins.
The structural analysis focuses on the cold trypsin residue determinants found in
a more extensive comparison of 27 trypsin sequences, and reveals a number of
structural features unique to the cold-adapted trypsins. The increased substrate
affinity of the psychrophilic trypsins is probably achieved by a lower
electrostatic potential of the S1 binding pocket particularly arising from
Glu221B, and from the lack of five hydrogen bonds adjacent to the catalytic
triad. The reduced stability of the cold trypsins is expected to arise from
reduced packing in two distinct core regions, fewer interdomain hydrogen bonds
and from a destabilized C-terminal alpha-helix. The helices of the cold trypsins
lack four hydrogen bonds and two salt-bridges, and they have poorer van der Waals
packing interactions to the body of the molecule, compared to the mesophilic
counterparts.
PMID- 10672013
TI - Resonance Raman study of multihemic c-type cytochromes from Desulfuromonas
acetoxidans.
AB - Two multihemic cytochromes c from the sulfur reducing bacteria Desulfuromonas
acetoxidans have been studied by optical and resonance Raman spectroscopy:
cytochrome c551.5, a trihemic cytochrome and cytochrome c Mr 50 000, a recently
isolated high molecular mass cytochrome. The redox and Raman characteristics of
cytochrome c551.5 are compared to those of the tetrahemic cytochromes c3 from
Desulfovibrio. While the redox behavior, followed by spectroelectrochemistry, is
similar to that of cytochrome c3, showing the same conformational change after
reduction of the highest potential heme, the Raman data show a contribution from
a His- form of the axial ligands and lead to the assignment of a band at 218 cm-1
to the Fe(III)-(His)2 stretching vibration. The Raman data on cytochrome c Mr 50
000 are in favor of an entirely low spin species with two different sets of axial
ligands. A partially reduced state is easily accessible by ascorbate addition.
PMID- 10672014
TI - Complementation of NADPH oxidase in p67-phox-deficient CGD patients p67-phox/p40
phox interaction.
AB - Chronic granulomatous disease (CGD) is due to a functional defect of the O2-
generating NADPH oxidase of phagocytes. Epstein-Barr-virus-immortalized B
lymphocytes express all the constituents of oxidase with activity 100 times less
than that of neutrophils. As in neutrophils, oxidase activity of Epstein-Barr
virus-immortalized B lymphocytes was shown to be defective in the different forms
of CGD; these cells were used as a model for the complementation studies of two
p67-phox-deficient CGD patients. Reconstitution of oxidase activity was performed
in vitro by using a heterologous cell-free assay consisting of membrane-suspended
or solubilized and purified cytochrome b558 that was associated with cytosol or
with the isolated cytosolic-activating factors (p67-phox, p47-phox, p40-phox)
from healthy or CGD patients. In p67-phox-deficient CGD patients, two cytosolic
factors are deficient or missing: p67-phox and p40-phox. Not more than 20% of
oxidase activity was recovered by complementing the cytosol of p67-phox-deficient
patients with recombinant p67-phox. On the contrary, a complete restoration of
oxidase activity was observed when, instead of cytosol, the cytosolic factors
were added in the cell-free assay after isolation in combination with cytochrome
b558 purified from neutrophil membrane. Moreover, the simultaneous addition of
recombinant p67-phox and recombinant p40-phox reversed the previous
complementation in a p40-phox dose-dependent process. These results suggest that
in the reconstitution of oxidase activity, p67-phox is the limiting factor; the
efficiency of complementation depends on the membrane tissue and the cytosolic
environment. In vitro, the transition from the resting to the activated state of
oxidase, which results from assembling, requires the dissociation of p40-phox
from p67-phox for efficient oxidase activity. In the process, p40-phox could
function as a negative regulatory factor and stabilize the resting state.
PMID- 10672015
TI - Cytochrome cM from synechocystis 6803. Detection in cells, expression in
Escherichia coli, purification and physical characterization.
AB - Based on DNA sequence data a novel c-type cytochrome, cytochrome cM, has been
predicted to exist in the cyanobacterium Synechocystis 6803. The precursor
protein consists of 105 amino acids with a characteristic heme-binding motif and
a hydrophobic domain located at the N-terminal end that is proposed to act as
either a signal peptide or a membrane anchor. For the first time we report the
detection of cytochrome cM in Synechocystis 6803 using Western blot analysis. The
soluble portion cytochrome cM has been overexpressed in Escherichia coli in two
forms, one with a poly histidine tag to facilitate purification and one without
such a tag. The overexpressed protein has been purified and shown to bind heme,
exhibiting an absorption peak in the Soret band near 416 nm and a peak in the
alpha band at 550 nm. The extinction coefficient of cytochrome cM is 23.2 +/- 0.5
mM-1.cm-1 for the reduced minus oxidized alpha band peak (550-535 nm). The
isoelectric point of cytochrome cM is 5.6 (without the histidine tag), which is
significantly lower than the pI of 7.2 predicted from the amino acid sequence.
The redox midpoint potential of cytochrome cM expressed in E. coli is 151 +/- 5
mV (pH 7.1), which is quite low compared to other c-type cytochromes in which a
histidine and a methionine residue serve as the axial ligands to the heme. This
work opens the way for determining the three-dimensional structure of cytochrome
cM and investigating its function in cyanobacteria.
PMID- 10672016
TI - Contribution of Are1p and Are2p to steryl ester synthesis in the yeast
Saccharomyces cerevisiae.
AB - In the yeast Saccharomyces cerevisiae, two acyl-CoA:sterol acyltransferases
(ASATs) that catalyze the synthesis of steryl esters have been identified, namely
Are2p (Sat1p) and Are1p (Sat2p). Deletion of either ARE1 or ARE2 has no effect on
cell viability, and are1are2 double mutants grow in a similar manner to wild-type
despite the complete lack of cellular ASAT activity and steryl ester formation
[Yang, H., Bard, M., Bruner, D. A., Gleeson, A., Deckelbaum, R. J., Aljinovic,
G., Pohl, T. M., Rothstein, R. & Sturley, S. L. (1996) Science 272, 1353-1356;
Yu, C., Kennedy, J., Chang, C. C. Y. & Rothblatt, J. A. (1996) J. Biol. Chem.
271, 24157-24163]. Here we show that both Are2p and Are1p reside in the
endoplasmic reticulum as demonstrated by measuring ASAT activity in subcellular
fractions of are1 and are2 deletion strains. This localization was confirmed by
fluorescence microscopy using hybrid proteins of Are2p and Are1p fused to green
fluorescent protein (GFP). Lipid analysis of are1 and are2 deletion strains
revealed that Are2p and Are1p utilize sterol substrates in vivo with different
efficiency; Are2p has a significant preference for ergosterol as a substrate,
whereas Are1p esterifies sterol precursors, mainly lanosterol, as well as
ergosterol. The specificity towards fatty acids is similar for both isoenzymes.
The lack of steryl esters in are1are2 mutant cells is largely compensated by an
increased level of free sterols. Nevertheless, terbinafine, an inhibitor of
ergosterol biosynthesis, inhibits growth of are1are2 cells more efficiently than
growth of wild-type. In a growth competition experiment are1are2 cells grow more
slowly than wild-type after several rounds of cultivation, suggesting that Are1p
and Are2p or steryl esters, the product formed by these two enzymes, are more
important in the natural environment than under laboratory conditions.
PMID- 10672017
TI - Changes in integrity and association of eukaryotic protein synthesis initiation
factors during apoptosis.
AB - Induction of apoptosis results in inhibition of the rate of overall protein
synthesis in a variety of cell types. We have shown previously that polypeptide
chain initiation factor eIF4GI is rapidly cleaved by caspase-3, whereas other
components of the eIF4F complex are much more stable during apoptosis in BJAB and
Jurkat cells. We have now extended our analysis to other factors involved in the
initiation of protein synthesis and we report here that eIF4B, the p35 subunit of
eIF3, and minor proportions of the alpha subunit of eIF2 and the eIF4E-binding
protein 4E-BP1 are also cleaved to give rise to discrete fragments. These
cleavages occur with delayed kinetics relative to that seen for eIF4GI, and
eIF2beta and eIF2gamma levels also decrease at a relatively late stage of
apoptosis. In contrast, the second form of eIF4G described recently, eIF4GII, is
cleaved as rapidly as eIF4GI under the same conditions. Purified recombinant
caspase-3 is able to degrade eIF4B and eIF3(p35) in vitro, producing fragments of
the same sizes as those seen in intact cells. Induction of apoptosis also results
in a biphasic change in the association of 4E-BP1 with eIF4E. Thus the progress
of apoptosis is characterized by a complex programme of changes in several
initiation factors, including the specific fragmentation or complete degradation
of some and alterations in the association status of others. These events are
likely to contribute to the inhibition of protein synthesis seen under these
conditions.
PMID- 10672018
TI - Functional characterization and mechanism of action of recombinant human
kynurenine 3-hydroxylase.
AB - The mitochondrial outer membrane enzyme kynurenine 3-hydroxylase (K3H) is an
NADPH-dependent flavin mono-oxygenase involved in the tryptophan pathway, where
it catalyzes the hydroxylation of kynurenine. K3H was transiently expressed in
COS-1 cells as a glutathione S-transferase (GST) fusion protein, and the pure
recombinant protein (rec-K3H) was obtained with a specific activity of about 2000
nmol.min-1.mg-1. Rec-K3H was shown to have an optimum pH at 7.5, to use NADPH
more efficiently than NADH, and to contain one molecule of non-covalently bound
FAD per molecule of enzyme. The mechanism of the rec-K3H-catalyzed reaction was
investigated by overall initial-rate measurements, and a random mechanism in
which combination of the enzyme with one substrate does not influence its
affinity for the other is proposed. Further kinetic studies revealed that K3H
activity was inhibited by both pyridoxal phosphate and Cl-, and that NADPH
catalyzed oxidation occurred even in the absence of kynurenine if 3
hydroxykynurenine was present, suggesting an uncoupling effect of 3
hydroxykynurenine with peroxide formation. This observation could be of clinical
interest, as peroxide formation could explain the neurotoxicity of 3
hydroxykynurenine in vivo.
PMID- 10672019
TI - The N-terminal beta-barrel structure of lipid body lipoxygenase mediates its
binding to liposomes and lipid bodies.
AB - Phospholipase A2 and a particular isoform of lipoxygenase are synthesized and
transferred to lipid bodies during the stage of triacylglycerol mobilization in
germinating cucumber seedlings. Lipid body lipoxygenase (LBLOX) is post
translationally transported to lipid bodies without proteolytic modification.
Fractionation of homogenates from cucumber cotyledons or transgenic tobacco
leaves expressing LBLOX showed that a small but significant amount was detectable
in the microsomal fraction. A beta-barrel-forming N-terminal domain in the
structure of LBLOX, as deduced from sequence data, was shown to be crucial for
selective intracellular transport from the cytosol to lipid bodies. Although a
specific signal sequence for targeting protein domains to the lipid bodies could
not be established, it was evident that the beta-barrel represents a membrane
binding domain that is functionally comparable with the C2 domains of mammalian
phospholipases. The intact beta-barrel of LBLOX was demonstrated to be sufficient
to target in vitro a fusion protein of LBLOX beta-barrel with glutathione S
transferase (GST) to lipid bodies. In addition, binding experiments on liposomes
using lipoxygenase isoforms, LBLOX deletions and the GST-fusion protein confirmed
the role of the beta-barrel as the membrane-targeting domain. In this respect,
the cucumber LBLOX differs from cytosolic isoforms in cucumber and from the
soybean LOX-1. When the beta-barrel of LBLOX was destroyed by insertion of an
additional peptide sequence, its ability to target proteins to membranes was
abolished.
PMID- 10672020
TI - Characterization of hydroxylaminobenzene mutase from pNBZ139 cloned from
Pseudomonas pseudoalcaligenes JS45. A highly associated SDS-stable enzyme
catalyzing an intramolecular transfer of hydroxy groups.
AB - Hydroxylaminobenzene mutase is the enzyme that converts intermediates formed
during initial steps in the degradation of nitrobenzene to a novel ring-fission
lower pathway in Pseudomonas pseudoalcaligenes JS45. The mutase catalyzes a
rearrangement of hydroxylaminobenzene to 2-aminophenol. The mechanism of the
reactions and the properties of the enzymes are unknown. In crude extracts, the
hydroxylaminobenzene mutase was stable at SDS concentrations as high as 2%. A
procedure including Hitrap-SP, Hitrap-Q and Cu(II)-chelating chromatography was
used to partially purify the enzyme from an Escherichia coli clone. The partially
purified enzyme was eluted in the void volume of a Superose-12 gel-filtration
column even in the presence of 0.05% SDS in 25 mM Tris/HCl buffer, which
indicated that it was highly associated. When the enzymatic conversion of
hydroxylaminobenzene to 2-aminophenol was carried out in 18O-labeled water, the
product did not contain 18O, as determined by GC-MS. The results indicate that
the reaction proceeded by intramolecular transfer of the hydroxy group from the
nitrogen to the C-2 position of the ring. The mechanism is clearly different from
the intermolecular transfer of the hydroxy group in the non-enzymatic Bamberger
rearrangement of hydroxylaminobenzene to 4-aminophenol and in the enzymatic
hydroxymutation of chorismate to isochorismate.
PMID- 10672021
TI - The wide binding properties of a wheat nonspecific lipid transfer protein.
Solution structure of a complex with prostaglandin B2.
AB - The 3D solution structure of wheat nonspecific lipid transfer protein (ns-LTP)
complexed with prostaglandin B2, a lipid with both vinyl and hydroxylated groups,
has been determined by 1H 2D NMR. The global fold of the protein is close to the
previously published structures of wheat, maize, barley and rice ns-LTPs. The
ligand is almost completely embedded in the hydrophobic core of the protein.
Structure comparisons of free and bound wheat ns-LTP reveal that the binding of
prostaglandin B2 hardly affects the global fold of the protein. The structural
data on this unusual complex are discussed and compared with other known ns-LTP
lipid-complexes.
PMID- 10672022
TI - The RadA protein from a hyperthermophilic archaeon Pyrobaculum islandicum is a
DNA-dependent ATPase that exhibits two disparate catalytic modes, with a
transition temperature at 75 degrees C.
AB - The radA gene is an archaeal homolog of bacterial recA and eukaryotic RAD51
genes, which are critical components in homologous recombination and
recombinational DNA repair. We cloned the radA gene from a hyperthermophilic
archaeon, Pyrobaculum islandicum, overproduced the radA gene product in
Escherichia coli and purified it to homogeneity. The purified P. islandicum RadA
protein maintained its secondary structure and activities in vitro at high
temperatures, up to 87 degrees C. It also showed high stability of 18.3 kcal.mol
1 (76.5 kJ.mol-1) at 25 degrees C and neutral pH. P. islandicum RadA exhibited
activities typical of the family of RecA-like proteins, such as the ability to
bind ssDNA, to hydrolyze ATP in a DNA-dependent manner and to catalyze DNA strand
exchange. At 75 degrees C, all DNAs tested stimulated ATPase activity of the
RadA. The protein exhibited a break in the Arrhenius plot of ATP hydrolysis at 75
degrees C. The cooperativity of ATP hydrolysis and ssDNA-binding ability of the
protein above 75 degrees C were higher than at lower temperatures, and the
activation energy of ATP hydrolysis was lower above this break point temperature.
These results suggest that the ssDNA-dependent ATPase activity of P. islandicum
RadA displays a temperature-dependent capacity to exist in two different
catalytic modes, with 75 degrees C being the critical threshold temperature.
PMID- 10672023
TI - Insertion of light-harvesting chlorophyll a/b protein into the thylakoid
topographical studies.
AB - The major light-harvesting chlorophyll a/b-binding protein (Lhcb1,2) of
photosystem II is inserted into the thylakoid via the signal recognition particle
dependent pathway. However, the mechanism by which the protein enters the
membrane is at this time unknown. In order to define some topographical
restrictions for this process, we constructed several recombinant derivatives of
Lhcb1 carrying hexahistidine tags at either protein terminus or in the stromal
loop domain. Additionally, green fluorescent protein (GFP) was fused to either
terminus. None of the modifications significantly impair the pigment-binding
properties of the protein in the in vitro reconstitution of LHCII. With the
exception of the C-terminal GFP fusion, all mutants stably insert into isolated
thylakoids in the absence of Ni2+ ions. The addition of low concentrations of
Ni2+ ions abolishes the thylakoid insertion of C-terminally His-tagged mutants
whereas the other His-tagged proteins fail to insert only at higher Ni2+
concentrations. The C-terminus of Lhcb1 must cross the membrane during protein
insertion whereas the other sites of Lhcb1 modification are positioned on the
stromal side of LHCII. We conclude that a Ni2+-complexed His tag and fusion to
GFP inhibit translocation of the protein C-terminus across the thylakoid. Our
observations indicate that the N-terminal and stromal domain of Lhcb1 need not
traverse the thylakoid during protein insertion and are consistent with a loop
mechanism in which only the C-terminus and the lumenal loop of Lhcb1 are
translocated across the thylakoid.
PMID- 10672024
TI - Reciprocal relationship between alpha1,2 mannosidase processing and
reglucosylation in the rough endoplasmic reticulum of Man-P-Dol deficient cells.
AB - The study of the glycosylation pathway of a mannosylphosphoryldolichol-deficient
CHO mutant cell line (B3F7) reveals that truncated Glc(0-3)Man5GlcNAc2
oligosaccharides are transferred onto nascent proteins. Pulse-chase experiments
indicate that these newly synthesized glycoproteins are retained in intracellular
compartments and converted to Man4GlcNAc2 species. In this paper, we demonstrate
that the alpha1,2 mannosidase, which is involved in the processing of Man5GlcNAc2
into Man4GlcNAc2, is located in the rough endoplasmic reticulum. The enzyme was
shown to be inhibited by kifunensine and deoxymannojirimycin, indicating that it
is a class I mannosidase. In addition, Man4GlcNAc2 species were produced at the
expense of Glc1Man5GlcNAc2 species. Thus, the trimming of Man5GlcNAc2 to
Man4GlcNAc2, which is catalyzed by this mannosidase, could be involved in the
control of the glucose-dependent folding pathway.
PMID- 10672025
TI - Sulfakinin neuropeptides in a crustacean. Isolation, identification andtissue
localization in the tiger prawn Penaeus monodon.
AB - The sulfakinin (SK) family of neuropeptides are characterized by a C-terminal
octapeptide sequence that begins with two acidic residues (most commonly DD), and
ends with YGHMRF-NH2, usually with the tyrosyl residue sulfated. So far,
sulfakinins have only been identified in insects and the present study was
initiated to investigate if the family is more widely distributed within the
arthropods. Purification of an extract of the central nervous system of the giant
tiger prawn Penaeus monodon has revealed three novel members of the sulfakinin
peptide family. One of the peptides, Pem SKI, has the sequence 95%) for a major clade of Pao-like retrotransposons, which
includes five mosquito sequences and the recently discovered Drosophila
retrotransposons BEL and ninja. This appears to represent a new family of Pao
like LTR-retrotransposons distinct from the Copia and Gypsy families.
PMID- 10672080
TI - Editorial
PMID- 10672079
TI - Edgewalking to internationalize nursing.
PMID- 10672081
TI - Best hope or last hope: access to phase III clinical trials of HER-2/neu for
advanced stage breast cancer patients.
AB - Breast cancer is a major public health problem, with a 12% incidence among women.
The over-expression of the proto-oncogene HER-2/neu is associated with 30% of
breast and ovarian cancers that are very aggressive and do not respond to
standard therapeutic regimens. Entrance into clinical trials can represent the
best hope and even the last hope for these patients. Entrance, however, is based
on satisfying eligibility criteria. In examining advanced stage breast cancer
patients' access to phase III clinical trials for HER-2/neu, two specific
arguments regarding eligibility will be addressed. First, if research is to
provide the utilitarian goal of the 'greatest good to the greatest number',
delineation of the population receiving the 'good', rather than a homogeneous sub
set of this population, must be addressed, along with patients' values and goals,
very relevant to determining a 'good life', how to achieve it, and whether a
treatment is a part of that process. Second, the 'good' being generated should
involve realistic, practical values of quality ways of living with advanced
breast cancer and not just increased survival, or cure. Arguments for relaxing
criteria are based on an accurate versus over-simplified interpretation of
utilitarian principles and concepts of human flourishing. Only through addressing
these issues can the true 'good' of clinical trials and research be given to the
greatest number of people.
PMID- 10672082
TI - Equipoise: an appropriate standard for ethical review of nursing research?
AB - When using control-group methodologies, the provision of different forms of
treatment, which may vary in efficacy, to similar groups of research subjects
must be ethically justified. The conventional justification is the existence of a
state of clinical equipoise, defined as a lack of consensus among the expert
community on the relative efficacy of the treatments. Control groups are
justified when the profession does not know which treatment confers more benefit;
otherwise, the provision of treatment known to be less effective than other
available treatment is unethical. The concept of equipoise was developed to
justify clinical trials of medical interventions. Equipoise has proven a durable
standard in studies of interventions that confer benefit regardless of the
subject's perception. However, equipoise does not apply when a substantive
benefit is conferred by the subject's perception. In psychosocial interventions,
a subject's experience of the intervention confers benefit and is used to
evaluate benefit. Therefore the subject is in a valid position to prefer one
treatment over the other and equipoise does not apply.
PMID- 10672083
TI - Advanced nursing practice: the case of nurse practitioners in three Australian
states.
AB - This paper provides insight into the work of nurse practitioners in three
Australian states. Using a case study approach, the aim of the study is to give
an account of some of the types of cases/patients who consult with the nurse
practitioners in the states visited and to offer insight into one of the policy
changes required to support the introduction of the nurse practitioner role. A
snowball sampling technique was used to obtain the sample population of both 10
nurse practitioners and other health care personnel. Semi-structured interviews
were conducted with the 39 respondents in both samples. The analysis of the 10
nurse practitioner interviews reported here shows that these nurses undertook a
wide range of roles. The results of the semi-structured interviews with the nurse
practitioners are described using four of the 10 interviews and reporting them as
case studies. The results highlighted the need to address legislation issues and
to prepare nurses adequately for their clinical setting and address the
difficulties of continuing education of rural nurses.
PMID- 10672084
TI - Assessment of older people: politics and practice in primary care.
AB - This paper reviews some of the key policy changes in the United Kingdom in
relation to older people that have influenced assessment practice across health
and social care, and have implications for nursing within emerging primary care
groups. The role of assessment in purchasing care packages raises tensions and
paradoxes for health and social care professionals that the paper sets out to
elucidate with particular reference to district nurses. The issues for nursing
have not been well described previously and questions such as key accountability,
rationing, multiagency and interprofessional working, and the consumer voice, are
discussed.
PMID- 10672085
TI - Graduate nurses: critical thinkers or better decision makers?
AB - This study evaluates the difference in development of critical thinking across
four groups of nurses at different stages of the academic process and their
perception of their decision-making ability in practice. With the move of nurse
education into institutes of higher education nationally, there are no empirical
data in the UK to suggest that graduates practice any differently from their non
graduate colleagues. An opportunistic sample of 82 nurses, was chosen from recent
admission on a pre-registration degree programme, to mature graduates, as well as
a group of experienced, non-graduate practitioners. A quasi-experimental, between
subjects design was used. A series of one-way ANOVAs was used to analyse the
difference in critical thinking across all four groups, employing the Watson
Glaser Critical Thinking Appraisal. Additionally, the Jenkins Clinical Decision
Making in Nursing Scale was used to determine the differences in decision-making
ability in practice across three of the groups with clinical experience.
Furthermore, a correlation was undertaken to determine what relationship, if any,
existed between critical thinking and decision-making in practice. It was found
that there was no significant difference in the critical thinking skills across
all groups studied, supporting the findings of other studies in the USA, which
examined the cognitive skills of students undertaking graduate programmes.
However, in their practice, it was found that those exposed to the academic
process were significantly better at decision-making than their non-academic
colleagues. Finally, no relationship could be found between the development of
critical thinking and decision-making in practice, suggesting that more work
needs to be done to look carefully at both critical thinking skills and decision
making in practice and the tools used to measure these.
PMID- 10672086
TI - Implementing contract learning in a clinical context: report on a study.
AB - This paper reports on a study of the implementation and evaluation of learning
contracts in a clinical context for a group of students who were in their third
year of study in a pre-registration bachelor of nursing degree programme in Hong
Kong. A learning contract was implemented as a learning tool in the students'
clinical placement in mental health nursing. An action research approach was used
in this study. Data were collected from questionnaires and interviews with
students and clinical instructors. Results showed that students and clinical
instructors generally agreed that there was an increase in students' autonomy and
motivation in learning with the use of a learning contract. It also increased the
sharing between students and clinical instructors. The findings of the
questionnaire and interviews supported each other. However, the lack of
experience in using contract learning and the limited time in the clinical areas
created difficulties for both students and clinical instructors. Despite the
limitations, contract learning is considered beneficial to students' learning and
has the potential to be used in clinical learning.
PMID- 10672087
TI - The minimization to clients of screen-detected breast cancer: a qualitative
analysis.
AB - Previous research has shown a low incidence of psychological morbidity in women
with screen-detected breast cancer when compared to women with symptomatic breast
cancer. Farmer et al. suggested that this might be due to the way the diagnosis
of breast cancer is given to women with screen-detected disease. In order to test
this hypothesis a detailed, in-depth, qualitative study was undertaken. The
sample consisted of women with symptomatic breast cancer (n=5), women with screen
detected invasive breast cancer (n=6) and women with screen-detected in-situ
breast cancer (n=5). The 'bad news consultations' with the surgeons, and
subsequent meetings with the breast care nurses (BCN), were tape recorded. The
women were also interviewed in their own homes within 7 days. The results
suggested that the women with screen-detected breast cancer received more
reassurance than the women with symptomatic breast cancer and that the benefits
of breast screening were emphasized by the surgeons and the BCNs. This led to
minimization of the significance of screen-detected disease. Women were found to
draw on a new conceptual model of early curable breast cancer which appears to be
associated with a low incidence of psychological morbidity.
PMID- 10672088
TI - How women receiving adjuvant chemotherapy for breast cancer cope with their
treatment: a risk management perspective.
AB - Retrospective interviews were undertaken with 12 women who had received an 18
week course of adjuvant chemotherapy for positive node breast cancer 1 year
previously, and who had not experienced cancer recurrence. The nonstandardized
interviews covered women's preconceptions about adjuvant chemotherapy, their
information needs, and the impact of treatment. The qualitative data analysis
drew upon the theoretical ideas of patient career, trajectory projection and
qualitative risk analysis. Some women regarded adjuvant chemotherapy as no more
than an 'insurance policy'. This perception may have arisen because doctors,
attempting to minimize patient anxiety, did not discuss the high risk of disease
recurrence which they faced. Other women equated adjuvant with curative
chemotherapy, and anticipated hair loss or almost certain death. The women tried
to cope with the physical and mental suffering associated with adjuvant
chemotherapy through normalizing strategies, such as keeping a brave face,
maintaining previous patterns of life, looking for humour and restructuring time.
However, the rapid alterations in physical and mental state resulting from cycles
of adjuvant chemotherapy resulted in a 'rollercoaster' experience for women which
made normalization more difficult. Health professionals caring for women who must
cope with uncertain future trajectories need to manage a risk communication
dilemma. A strategy of fully informing women about the risks they face may cause
anxiety or depression, and even impede recovery, given the evidence for
psychological influences on health outcomes. But, if women do not understand the
medical thinking on which their treatment is based, their misconceptions may be
equally damaging.
PMID- 10672089
TI - The patient's thoughts and feelings about their transfer from intensive care to
the general ward.
AB - This qualitative, phenomenological study was undertaken to find out how patients
felt about being transferred from the intensive care unit to the ward. The six
patients who took part in the study, had been in intensive care for more than 4
days. Their transfer was planned as part of their recovery from a critical
illness. Following transfer to the ward, the patients were interviewed using a
semi-structured approach. The interviews were audio-taped, and transcriptions
from the tapes were analysed for meaning and interpretation. Findings supported
the literature that was reviewed, in that transfer from intensive care to the
ward was a traumatic experience for the patient, who often found it confusing,
stressful and tiring. Improvements to the transfer process can be guided using
the information from the literature review and findings of the study.
PMID- 10672090
TI - Children visiting family and friends on adult intensive care units: the nurses'
perspective.
AB - Recent surveys show that children are still restricted from visiting their
critically ill family and friends on many adult intensive care units throughout
the country. The purpose of this small-scale exploratory pilot study was to
examine and describe the experiences and perceptions of trained nurses towards
children visiting within this setting. The aim of the study was to gain greater
insight and understanding into the reason why, despite evidence to support the
benefits to children of visiting their critically ill family and friends, they
remain discouraged and restricted. It is hoped that the study will act as an
initial enquiry to generate themes and further research questions. A qualitative
research approach was adopted and in-depth focused interviews used as a method of
data collection. The participants of the study were trained nurses working on an
adult intensive care unit in a district general hospital in England. A total of
12 individual interviews were conducted which were audiotaped in full and
analysed using a method of thematic content analysis. The value of the research
is to promote family-centred care within an adult intensive care environment to
meet the neglected needs of the well children of the critically ill person. The
findings suggest that the participants in the study attempted to offer valuable
support to children visiting their critically ill family and friends, but,
despite an open visiting policy, children rarely visited within this setting. The
desire of the well parent to protect and shield the child from the crisis of
critical illness was perceived by the participants to be the main reason why they
did not visit. To provide family-centred care within an adult intensive care
setting has many implications for practice and several of these important issues
are discussed. These include the educational and training needs of nursing staff
and the importance of adopting a collaborative team approach to providing care
for the critically ill person and their family. The need to generate research and
literature from within the United Kingdom's health care system has also been
identified and recommendations for further studies are proposed.
PMID- 10672091
TI - The development of competency standards for specialist critical care nurses.
AB - In defining the contemporary role of the specialist nurse it is necessary to
challenge the concept of nursing as merely a combination of skills and knowledge.
Nursing must be demonstrated and defined in the context of client care and
include the broader notions of professional development and competence. This
qualitative study sought to identify the competency standards for nurse
specialists in critical care and to articulate the differences between entry-to
practice standards and the advanced practice of specialist nurses. Over 800 hours
of specialist critical care nursing practice were observed and grouped into
'domains' or major themes of specialist practice using a constant comparison
qualitative technique. These domains were further refined to describe attributes
of the registered nurses which resulted in effective and/or superior performance
(competency standards) and to provide examples of performance (performance
criteria) which met the defined standard. Constant comparison of the emerging
domains, competency standards and performance criteria to observations of
specialist critical care practice, ensured the results provided a true reflection
of the specialist nursing role. Data analysis resulted in 20 competency standards
grouped into six domains: professional practice, reflective practice, enabling,
clinical problem solving, teamwork, and leadership. Each of these domains is
comprised of between two and seven competency standards. Each standard is further
divided into component parts or 'elements' and the elements are illustrated with
performance criteria. The competency standards are currently being used in
several Australian critical care educational programmes and are the foundation
for an emerging critical care credentialling process. They have been viewed with
interest by a variety of non-critical care specialty groups and may form a common
precursor from which further specialist nursing practice assessment will evolve.
PMID- 10672092
TI - Family members' experience of familial amyloidotic polyneuropathy disease--an
infernal struggle and a fact of life.
AB - Familial amyloidotic polyneuropathy is a fatal, hereditary, systemic, progressive
amyloidosis. No previous qualitative study of the family members' experience of
the disease has been published. The purpose of this phenomenological study was to
understand the lived experience of family members whose nearest and dearest
suffered from familial amyloidotic polyneuropathy. In-depth interviews were
conducted with six family members. The analysis of the data was inspired by
Colaizzi's method. Two major theme categories, difficult to accept and forced to
accept, emerged from the interviews. Implications for nursing practice, such as
genetic counselling and support, are discussed.
PMID- 10672093
TI - Illness narratives of persons with post-polio syndrome.
AB - This qualitative study investigated the lifetime illness experience of
individuals with the 'late effects' of polio or post-polio syndrome. Fifteen
individuals were interviewed twice about their illness experience and the
interviews were transcribed verbatim. The empirical material first underwent a
categorization process. The preliminary categories generated through this
analysis were then condensed into broader categories which in the final analysis
gave rise to the following temporal pattern or stages of the illness experience:
(1) the acute phase of polio and subsequent treatment and care; (2)
rehabilitation and care at institutions for the disabled; (3) adaptation to a new
life; (4) living with the post-polio syndrome today, and finally, (5) memories of
the past and apprehensions concerning the future. In spite of the difficult
experiences of falling ill and slowly recovering from a life-threatening disease,
these individuals have had a good life and accomplished most of their ambitions
in the areas of work and family life. Their present psychosocial situation is
complicated by the symptoms of the post-polio syndrome which make them more
vulnerable to stress, but they are able to handle this burden except when any
added strain makes it overwhelming. This potential vulnerability may sometimes
express itself as a sudden flashback to traumatic polio experiences and it is
therefore important that nurses are aware of the illness history of this patient
group.
PMID- 10672094
TI - Psychiatric nurses' thoughts and feelings about restraint use: a decision
dilemma.
AB - Patients continue to be physically restrained in psychiatric in-patient units.
Studies concerned with staff-related variables have suggested that the emotional
reactions of professionals to violent or potentially violent patients may
influence their use of restrictive measures. However, no research existed that
described psychiatric nurses' thoughts and feelings while they were involved in
restraint situations nor what effects their thoughts and feelings had on their
decision to restrain. Therefore, an ethnographic qualitative study was conducted
in order to describe systematically nurses' thoughts and feelings toward
restraint use in the in-patient psychiatric setting. The conceptual approach
guiding the study was Etzioni's (1992) theoretical work on the role of normative
affective factors in decision making. Following ethical approval of the study,
ethnographic interviews were conducted with six nurses from an in-patient
psychiatric unit who had participated in a situation involving the physical
restraint of a patient. The analysis of the nurses' thoughts and feelings
revealed that the restraint situation represented a decision dilemma for them.
This overall finding was supported by four themes: (1) the framing of the
situation: the potential for imminent harm; (2) the unsuccessful search for
alternatives to physical restraints; (3) the conflicted nurse; and (4) the
contextual conditions of restraint. The results indicated that restraint use is
more complex than is currently conveyed in the literature in that normative
affective factors influenced nurses' restraint decisions. The findings advance
our understanding of why restraints continue to be used in psychiatric units.
Further research is necessary to examine the findings in other settings and with
a larger and more diverse population in order to draw definitive conclusions
about the continued use of physical restraints in the care of patients on
psychiatric units in hospitals.
PMID- 10672095
TI - Patients' perceptions of seclusion: a qualitative investigation.
AB - Twelve patients receiving acute in-patient psychiatric care in Queensland,
Australia, participated in semi-structured interviews to elicit their perceptions
of seclusion. All respondents had experienced time in seclusion within the 7 days
prior to interview. Interviews were audiotaped, transcribed and analysed using
content analysis. Five major themes emerged: use of seclusion, emotional impact,
sensory deprivation, maintaining control and staff-patient interaction. The
prevailing negativity towards seclusion underscores the need for ongoing critical
review of its use. In particular, the relationship between patient responses to
seclusion and the circumstances in which seclusion takes place requires greater
consideration. Interventions such as providing information to patients about
seclusion, increased interaction with patients during seclusion, attention to
privacy and effective debriefing following seclusion may help to reduce the
emotional impact of the practice.
PMID- 10672096
TI - What do people need psychiatric and mental health nurses for?
AB - The study reported here aimed to describe, by consulting with psychiatric
practitioners of different disciplines, what people in contact with mental health
services need nurses for, in terms of core nursing activity. Yet, recent trends
have also been towards consumer-led definitions of good practice. The views of
service and ex-service users can contribute much to an exploration of the role of
psychiatric and mental health nurses and these perspectives were incorporated
into the study. Given the lack of existing theory, a qualitative, grounded theory
methodology was selected. In order to generate data rich enough for the analysis,
focus groups of psychiatric nurses, social workers, service users, psychiatrists,
carers and professions allied to medicine were sampled (13 groups, n=92) on the
basis of the themes emerging from the data. Using critical incident technique
(Flanagan 1954), the groups were invited to give examples of effective and
ineffective nursing interventions, in relation to specific patient needs. The
taped material was transcribed and analysed with the help of a computer package
(QSR NUD.IST). This led to the selection of a core category, 'knowing you,
knowing me', which described service users' and professionals' expectations that
nurses are best placed to second guess the needs of patients and present
themselves accordingly. Thus, nurses were expected, moment by moment, to know
whether to be the patient's friend, a friendly professional, or take a more
distant professional stance. The continuum entails different levels of knowledge
and power, different language forms and different approaches to structuring time.
Nurses themselves are most likely to prefer a position of friendly professional,
from which they can move to a more intimate or distant role. Further study is
needed to explore how nurses predict patients' expectations of them using a
symbolic interactionist framework.
PMID- 10672097
TI - Psychiatric nursing and compulsory psychiatric care.
AB - Community psychiatric nurses (CPNs) have long been involved in the operations of
the English Mental Health Acts. Research has shown that compulsory detention is
not used uniformly or consistently. Rates of involuntary hospitalization are
reported to vary widely across Europe, but there is some consensus on patient
profiles. The ethnicity, social status and gender of the patient, the involvement
of the police, the availability of care, problems caused to relatives, and the
country and particular legislative system where these judgements take place, all
influence who is compulsorily detained. This article reviews recent evidence from
Europe and argues that involuntary psychiatric care can no longer be seen as
entirely dependent on the symptoms and behaviour of the patient and that CPNs
should be aware of and reflect upon these factors before invoking the detention
process.
PMID- 10672098
TI - Are patients who self-administer their medicines in hospital more satisfied with
their care?
AB - Patient self-administration of medicines in hospital prior to discharge is being
seen increasingly as good practice by health professionals. Previous studies have
looked for increased compliance and knowledge or asked whether patients liked
self-administration and have not clearly demonstrated the benefits. This study
surveys patients' views on self-administration and on their care. In particular
it looks at the discharge process and the way information was given to the
patient on discharge. Questionnaires were distributed to 309 patients being
discharged from general medical wards of a teaching hospital in Central England
to be completed by the patients after their discharge from hospital. Of these,
202 were returned to a separate university department for analysis. Although this
study has been undertaken on only two wards, the survey has potential for large
scale use. Findings which were consistent with previous work were that a great
majority of patients who had self-administered their medicines would like to
again, whilst those who had not had that opportunity were less likely to choose
to self-administer in the future. However, this study found that a majority of
patients under 60-years-old would choose to self-administer their medicines in
hospital even if they had not been given the opportunity to do so recently. It
was also found that patients who had administered their own medicines in hospital
were more likely to report their overall care as excellent and were more
satisfied with the discharge process than patients who had not.
PMID- 10672099
TI - An evaluation of the safety and effectiveness of telephone triage as a method of
patient prioritization in an ophthalmic accident and emergency service.
AB - Service changes in the accident and emergency service at Manchester Royal Eye
Hospital in England resulted in a telephone triage-based referral service for
health care professionals. It became clear that this service needed evaluation in
order to assure both providers and users of the service that this referral
strategy, based on experienced nurse practitioners making decisions about patient
priority, was safe and effective. The evaluation was extended to encompass the
other area of the service where telephone referrals tend to be directly from
patients. A mixed method was used. Information gained within the telephone triage
conversation was compared with a final diagnosis through retrospective analysis
of secondary data; the documentation of those patients who were not given access
to the service initially was followed-up to ensure that this decision was safe
and a number of nurses were questioned about telephone information gathering,
using partially structured interviews. The study showed that nurse practitioners
within the accident and emergency service were able to elicit accurate
information from the telephone triage conversation on which to base a decision
about patient access in most cases (76% over the whole service). This resulted in
the appropriate prioritization of patients. No patient who needed urgent access
to the service was denied it. The decisions made to deny urgent appointments to a
number of patients were safe in all cases. It appears that one of the problem
areas in the gathering of information for prioritization purposes is in the
nurses' telephone triage discussions with some, but by no means all, doctors.
Some general practitioners seemed unwilling to discuss the patient and give
accurate information to a nurse and this is an area which appears to need some
further work.
PMID- 10672100
TI - Exploring the risks associated with induction of labour: a retrospective study
using the NIMATS database. Northern Ireland Maternity System.
AB - Induction of labour is a valuable obstetric procedure, providing obstetricians
with the means to intervene should the health of the fetus be in jeopardy.
Currently the most common reason for induction of labour is prolonged pregnancy,
as obstetricians and midwives are concerned about the risks of postmaturity such
as stillbirth, intrapartum asphyxia and birth trauma which are often associated
with prolonged pregnancy (Lagrew & Freeman 1986). A retrospective comparative
study was carried out in a large maternity unit to identify whether or not there
was clinical evidence to support a policy of elective induction for post-term
pregnancy. Three years' data were extracted from the Northern Ireland Maternity
System (NIMATS) by writing new queries to the system. These data on 3262 women
who delivered during 1994-96 were analysed to compare the outcomes for women who
were induced with women who delivered spontaneously. Although the findings from
the study in many instances failed to demonstrate statistical significance
between the groups they did however, have important clinical significance. For
example, those women who were induced had a 5% higher rate of caesarean section,
17% higher rate of epidural analgesia and on average a greater estimated blood
loss. Statistical significance was evident when the apgar scores of the infants
were compared; those induced had lower Apgars at 1 minute (7. 78 in the induced
group compared to 7.9 in the spontaneous group [P < 0.01]) and at 5 min (8.99 in
the induced group compared to 9.05 in the spontaneous group [P < 0.02]).
PMID- 10672101
TI - Normal labour: a concept analysis.
AB - Midwives practice within the normal childbirth paradigm. It is argued that
midwives failure to define normality has allowed increasing technicalization and
medicalization of the normal physiological process of birth because doctors so
closely define abnormality. A concept analysis model is used to clarify what is
meant by the term 'normal labour'; the emphasis being on understanding what
normal labour is as it applies to midwifery practice today. This analysis
highlights the importance of movement and the sequential nature of normal labour,
and reveals how this is implicit within the other uses of both the words normal
and labour. The final definition of normal labour offered is intended to be
complimentary to existing medical determinants of progress of normal labour,
because as the body of the text stresses, medical knowledge is fundamentally
enmeshed in midwifery care.
PMID- 10672102
TI - Critical thinking and nursing scripts: the case for the development of both.
AB - It is argued that contemporary nursing education's emphasis on the conscious
development of nurses' critical reasoning skills fails to take account of the
complexity of both human cognition and clinical nursing practice. Human cognition
centrally includes unconscious or tacit processes and clinical nursing practice
is typified by the simultaneous presentation of clinical and non-clinical cues
and competing clinical goals. Contemporary emphases on conscious critical
thinking are largely consistent with the differing theoretical frameworks which
have informed the study of nurses' clinical reasoning in the last 30 years, most
of which permit the use of simulated case study. These frameworks, that is,
decision theory, information processing and skills acquisition theory, are
described and their limitations highlighted. In addition, an alternative
theoretical framework, that of schema or script theory, which does take account
of the complexities of cognition and practice, is discussed. Its implications for
nursing practice and education are also outlined.
PMID- 10672103
TI - Dialysis as 'deus ex machina': a critical analysis of haemodialysis.
AB - This paper examines the context of dialysis from a critical and philosophical
standpoint. The traditional attitude of dialysis as an all-saving medical wonder
is examined. An alternative interpretation is offered using the analogy of
'experiment' to emphasize the uncertainty, power and control surrounding the
treatment of end-stage renal disease. In order for the experiment (of dialysis)
to occur, variables (patients) need to be controlled. Control can be found in the
social structures around the experiment of dialysis which provide an environment
conducive to its success.
PMID- 10672104
TI - Cognitive behaviour therapy: teaching a client the ABC model--the first step
towards the process of change.
AB - Research suggests that clients need to be made aware of the relationship between
thinking and emotional and behavioural reactions at the start of the therapeutic
work. This paper looks at the clinical processes of educating the client about
this relationship in a seven-step ABC model. Rationales for each of the seven
steps are given. The model illustrates the process of generating alternative
beliefs in relation to a negative event and shows consequences of holding helpful
and unhelpful beliefs.
PMID- 10672105
TI - Aggression and violence in health care professions.
AB - Although violence is increasing in most workplaces, it has become a significant
problem in health care professions. Not only has the number of incidents
increased but also the severity of the impact has caused profound traumatic
effects on the primary, secondary and tertiary victims. More health care
professionals than ever are suffering from symptoms of post-traumatic stress
disorder. Addressing the problem of violence in the workplace has been
exacerbated by a lack of a clear definition of what constitutes aggression and
violence. As a result, some administrators have been slow to commit resources to
prevent further incidents and mitigate the impact. This article describes the
magnitude of the problem from both an academic research and an operational
perspective. A definition is presented as an initial step towards standardizing
the research, and establishing an appropriate baseline upon which intervention
policies and procedures can be created. This benchmark will also help to
encourage empirical research into aggression and violence in health care
professions and other professions. Further research needs to be conducted to
create a comprehensive instrument that can more accurately measure the range of
incidents and the severity of the impact.
PMID- 10672106
TI - Educational input and patient outcomes: exploring the gap.
AB - Over the last two decades, the health care professions in the United Kingdom have
seen an unparalleled expansion of continuing professional education (CPE) and
development (CPD) programmes; however, there is little empirical evidence that
these enhance the care delivered to patients. Further research is also needed to
demonstrate that these initiatives are linked to improved patient outcomes. If
health care educators are to move towards an 'evidence-based curriculum', some
restructuring of courses may be needed. Priorities should be set and decisions
made, based on the results of reliable and valid research into the clinical
outcomes of CPE. To evaluate courses and demonstrate educational effectiveness
solely in terms of student satisfaction is not enough; to survive in the world of
evidence-based care, educators must also demonstrate their contribution to
clinical effectiveness. However, the neoteric field of impact evaluation lacks
not only validated research methods, but also an agreed agenda for future
research. Drawing on interviews undertaken with nurses who have participated in
education evaluations and the relevant literature, this paper discusses the
available data collection instruments and the development of viable research
designs and methods, which are urgently needed to assess the outcomes of
professional education programmes.
PMID- 10672107
TI - Community development: a critical review of approaches to evaluation.
AB - With the growing interest in community-based initiatives, this discussion paper
focuses upon the evaluation of community development. It reviews three areas and
highlights the complex and contentious nature of evaluation in this field.
Commencing with approaches to evaluation, it critically reviews proposed methods
and suggests that, rather than provide clarity and guidance, the competing
designs are confusing for the potential researcher. Second, the discussion moves
to evaluative terms that are applied to community development, suggesting that
there is a mismatch between professional and lay interpretations with an ultimate
impact upon the validity of their measurement. It uses the terms community and
empowerment to make these differences more explicit. Finally, the paper argues
that, although the aim of community-based initiatives is to bring about community
health gain, gauging the pervasiveness of discreet project work is testing. It
concludes by suggesting that a move away from an evaluative model based upon
empowerment towards one which considers health and social capital may be a way
forward.
PMID- 10672108
TI - Validation of a new method for patient classification, the Oulu Patient
Classification.
AB - At Vasa Central Hospital in Western Finland a further development of the Oulu
Patient Classification (OPC) has been made by the development of weight
coefficients and by estimating the nursing care intensity per nurse. The daily
level of nursing care intensity of a ward is expressed by the number of nursing
care intensity points per nurse. This article presents results from a validity
test of the OPC at Vasa Central Hospital. The test was carried out by comparing
the daily patient classifications by means of the OPC against measurements made
by means of a new measuring instrument, the 'Professional Assessment of Optimal
Nursing Care Intensity Level' (PAONCIL) developed at the Vasa Central Hospital.
The study was implemented in eight wards during a period of 3 months. The data
material consisted of two parts, the daily patient classifications based on the
OPC (n = 19 324) and the measurements by means of the PAONCIL forms (n = 8458).
Simple and multiple linear regression analyses were used as statistical methods
in quantifying the linear relationship between the two interval-scaled variables.
In the test of concurrent validity the coefficient of determination was 0.366,
i.e. the association between these two indicators is fairly strong (36.6%). The
testing of construct validity showed that the construct validity of the indicator
hardly deteriorates as a result of the patients being placed in separate nursing
care intensity categories. There was a clear correlation between the scores
allotted by the indicator to the six different sub-areas of nursing care. When
examining the construct validity of the OPC, no factors with independent
explanatory power in predicting PAONCIL values were discovered other than those
of the OPC. The OPC proved on the basis of this research material and these
statistical methods to possess fairly adequate validity, and thus there is a good
basis for further research and a development of nursing care.
PMID- 10672109
TI - Patient preferences for care by general internists and specialists in the
ambulatory setting.
AB - OBJECTIVE: To investigate patients' preferences for care by general internists
and specialists for common medical conditions. DESIGN: Telephone interview.
SETTING: A convenience sample of general internal medicine practices at 10
eastern academic medical centers. PATIENT/PARTICIPANTS: A probability sample of
314 participants who had at least one visit with their primary care physician
during the preceding 2 years. MEASUREMENTS AND MAIN RESULTS: Items addressed
patients' attitudes concerning continuity of care, preferences for care by
general internists or specialists for common medical problems, and perceptions
about the competency of general internists and specialists to manage these
problems. Continuity was important to participants, with 63% reporting they
preferred having one doctor. Respondents were willing to wait 3 or 4 days to see
their regular doctor (85%) and wanted their doctor to see them in the emergency
department (77%) and monitor their care while in the hospital (94%). A majority
(>60%) preferred care from their regular doctor for a variety of new conditions.
Though respondents valued continuity, 84% felt it was important to be able to
seek medical care from any type of physician without a referral, and 74%
responded that if they needed to see a specialist, they were willing to pay out
of-pocket to do so. Although most participants (98%) thought their regular doctor
was able to take care of usual medical problems, the majority thought that
specialists were better able to care for allergies (79%) and better able to
prescribe medications for depression (65%) and low-back pain (72%). CONCLUSIONS:
Participants preferred to see their general internist despite their perceptions
that specialists were more competent in caring for the conditions we examined.
However, they wanted unrestricted access to specialists to supplement care
provided by general internists.
PMID- 10672110
TI - Screening and intervention for alcohol problems. A national survey of primary
care physicians and psychiatrists.
AB - OBJECTIVE: To describe adult primary care physicians' and psychiatrists' approach
to alcohol screening and treatment, and to identify correlates of more optimal
practices. DESIGN: Cross-sectional mailed survey. PARTICIPANTS: A national
systematic sample of 2,000 physicians practicing general internal medicine,
family medicine, obstetrics-gynecology, and psychiatry. MEASUREMENTS: Self
reported frequency of screening new outpatients, and treatment recommendations in
patients with diagnosed alcohol problems, on 5-point Likert-type scales. MAIN
RESULTS: Of the 853 respondent physicians (adjusted response rate, 57%), 88%
usually or always ask new outpatients about alcohol use. When evaluating patients
who drink, 47% regularly inquire about maximum amounts on an occasion, and 13%
use formal alcohol screening tools. Only 82% routinely offer intervention to
diagnosed problem drinkers. Psychiatrists had the most optimal practices; more
consistent screening and intervention was also associated with greater confidence
in alcohol history taking, familiarity with expert guidelines, and less concern
that patients will object. CONCLUSIONS: Most primary care physicians and
psychiatrists ask patients about alcohol use, but fewer use recommended screening
protocols or offer formal treatment. A substantial minority of physicians miss
the opportunity to intervene in alcohol problems. Efforts to improve physicians'
screening and intervention for alcohol problems should address their confidence
in their skills, familiarity with expert recommendations, and beliefs that
patients object to their involvement
PMID- 10672111
TI - Bridging cultural differences in medical practice. The case of discussing
negative information with Navajo patients.
AB - BACKGROUND: Cultural differences between doctors and their patients are common
and may have important implications for the clinical encounter. For example, some
Navajo patients may regard advance care planning discussions to be a violation of
their traditional values. OBJECTIVE: To learn from Navajo informants a culturally
competent approach for discussing negative information. DESIGN: Focused
ethnography. SETTING: Navajo Indian reservation, northeast Arizona. PARTICIPANTS:
Thirty-four Navajo informants, including patients, traditional healers, and
biomedical health care providers. MEASUREMENT: In-depth interviews. MAIN RESULTS:
Strategies for discussing negative information were identified and organized into
four stages. Assessment of patients is important because some Navajo patients may
be troubled by discussing negative information, and others may be unwilling to
have such discussions at all. Preparation entails cultivating a trusting
relationship with patients, involving family members, warning patients about the
nature of the discussion as well as communicating that no harm is intended, and
facilitating the involvement of traditional healers. Communication should proceed
in a caring, kind, and respectful manner, consistent with the Navajo concept k'e.
Reference to a third party is suggested when discussing negative information, as
is respecting the power of language in Navajo culture by framing discussions in a
positive way. Follow-through involves continuing to care for patients and
fostering hope. CONCLUSIONS: In-depth interviews identified many strategies for
discussing negative information with Navajo patients. Future research could
evaluate these recommendations. The approach described could be used to
facilitate the bridging of cultural differences in other settings.
PMID- 10672112
TI - Intensive care unit use and mortality in the elderly.
AB - OBJECTIVE: To examine utilization and outcomes of intensive care unit (ICU) use
for the elderly in the United States. DESIGN: We used 1992 data from the Health
Care Financing Administration to examine ICU utilization and mortality by age and
admission reason for hospitalizations of elderly Medicare beneficiaries. MAIN
RESULTS: Use of the ICU was least likely for the oldest elderly overall (85+
years, 21.1% of admissions involved ICU; 75-84 years, 27.9%; 65-74 years, 29.7%),
but more likely during surgical admissions. Eighty-three percent of the Medicare
patients who received intensive care survived at least 90 days. Of the oldest
elderly, 74% survived. Even among the 10% most expensive ICU hospitalizations,
77% of all patients and 62% of those 85 years and older survived at least 90
days. CONCLUSIONS: The likelihood of ICU use among these elderly decreased with
age, especially among those 85 years or older. Diagnostic mix importantly
influenced ICU use by age. The great majority of the elderly, including those 85
years and older and those receiving the most expensive ICU care, survived at
least 90 days.
PMID- 10672113
TI - The impact of leaving against medical advice on hospital resource utilization.
AB - OBJECTIVE: To assess the effect of hospital discharge against medical advice
(AMA) on the interpretation of charges and length of stay attributable to
alcoholism. DESIGN: Retrospective cohort. Three analytic strategies assessed the
effect of having an alcohol-related diagnosis (ARD) on risk-adjusted utilization
in multivariate regressions. Strategy 1 did not adjust for leaving AMA, strategy
2 adjusted for leaving AMA, and strategy 3 restricted the sample by excluding AMA
discharges. SETTING: Acute care hospitals. PATIENTS: We studied 23,198 pneumonia
hospitalizations in a statewide administrative database. MEASUREMENTS AND MAIN
RESULTS: Among these admissions, 3.6% had an ARD, and 1.2% left AMA. In strategy
1 an ARD accounted for a $1,293 increase in risk-adjusted charges for a
hospitalization compared with cases without an ARD ( p =.012). ARD-attributable
increases of $1,659 ( p =.002) and $1,664 ( p =. 002) in strategies 2 and 3
respectively, represent significant 28% and 29% increases compared with strategy
1. Similarly, using strategy 1 an ARD accounted for a 0.6-day increase in risk
adjusted length of stay over cases without an ARD ( p =.188). An increase of 1
day was seen using both strategies 2 and 3 ( p =.044 and p =.027, respectively),
representing significant 67% increases attributable to ARDs compared with
strategy 1. CONCLUSIONS: Discharge AMA affects the interpretation of the relation
between alcoholism and utilization. The ARD-attributable utilization was greater
when analyses adjusted for or excluded AMA cases. Not accounting for leaving AMA
resulted in an underestimation of the impact of alcoholism on resource
utilization.
PMID- 10672114
TI - Cost-effectiveness of low-molecular-weight heparin in the treatment of proximal
deep vein thrombosis.
AB - OBJECTIVE: To estimate the cost-effectiveness of low-molecular-weight heparin
(LMWH) in the treatment of proximal lower extremity deep venous thrombosis.
DESIGN: Cost-effectiveness analysis that includes the treatment of the index case
and simulated 3-month follow-up. SETTING: Acute care facility. PATIENTS AND
PARTICIPANTS: Hypothetical cohorts of 1,000 patients who present with proximal
deep venous thrombosis. INTERVENTIONS: Intravenous unfractionated heparin (UH),
LMWH (40% at home, 60% in hospital), or selective UH/LMWH (UH for hospitalized
patients and LMWH for patients treated at home). MEASUREMENTS AND MAIN RESULTS:
The outcomes were recurrent thrombosis, mortality, direct medical costs, and
marginal cost-effectiveness ratios from the payer's perspective. At the base-case
and under most assumptions in the sensitivity analysis, the LMWH and the
selective UH/LMWH strategies dominate the UH strategy i.e., they result in fewer
cases of recurrent thrombosis and fewer deaths, and they save resources. The
savings occur primarily by decreasing the length of stay. The LMWH strategy
resulted in lower costs as compared with the UH strategy when the proportion of
patients treated at home was more than 14%. Treating 1, 000 patients with the
LMWH strategy as compared with the UH/LMWH strategy would result in 10 fewer
cases of recurrent thrombosis, 1.2 fewer deaths, at an additional cost of
$96,822; the cost-effectiveness ratio was $9,667 and $80,685 per recurrent
thrombosis or death prevented, respectively. CONCLUSIONS: Treatment with LMWH
leads to savings and better outcomes as compared with UH in patients with lower
extremity deep venous thrombosis. The selective UH/LMWH strategy is an
alternative option.
PMID- 10672115
TI - Health and health care among housestaff in four U.S. internal medicine residency
programs.
AB - BACKGROUND: Although there have been many studies of the health care services
that resident physicians provide, little is known about the health care services
they receive. OBJECTIVE: To describe residents' perceptions of the health care
they receive. DESIGN: Anonymous mailed survey. SUBJECTS: All 389 residents in
four U.S. categorical internal medicine training programs. MAIN RESULTS: Three
hundred sixteen residents responded (83%). In aggregate, 116 (37%) reported
having no primary care physician, and 36 (12%) reported that they are their own
primary care physician. These figures varied substantially across the four
programs. Most residents reported receiving basic screening and preventive
services; however, their attitudes toward their health and health care differed
across postgraduate level, gender, and program. Many residents reported that
their long and unpredictable hours interfered with their ability to schedule
clinician visits, that their health had declined because of residency, that
programs and other residents were unsupportive of residents' health care needs,
and that residency raised special issues of privacy that limited access to health
care. CONCLUSIONS: Despite high rates of receipt of preventive services, these
internal medicine residents identified several barriers that limited their access
to health care. Program directors should explore these barriers and, at the same
time, reevaluate the messages being sent to resident physicians about maintaining
their health and health care.
PMID- 10672116
TI - Is the professional satisfaction of general internists associated with patient
satisfaction?
AB - BACKGROUND: The growth of managed care has raised a number of concerns about
patient and physician satisfaction. An association between physicians'
professional satisfaction and the satisfaction of their patients could suggest
new types of organizational interventions to improve the satisfaction of both.
OBJECTIVE: To examine the relation between the satisfaction of general internists
and their patients. DESIGN: Cross-sectional surveys of patients and physicians.
SETTING: Eleven academically affiliated general internal medicine practices in
the greater-Boston area. PARTICIPANTS: A random sample of English-speaking and
Spanish-speaking patients (n = 2,620) with at least one visit to their physician
(n = 166) during the preceding year. MEASUREMENTS: Patients' overall satisfaction
with their health care, and their satisfaction with their most recent physician
visit. MAIN RESULTS: After adjustment, the patients of physicians who rated
themselves to be very or extremely satisfied with their work had higher scores
for overall satisfaction with their health care (regression coefficient 2.10; 95%
confidence interval 0.73-3.48), and for satisfaction with their most recent
physician visit (regression coefficient 1.23; 95% confidence interval 0.26-2.21).
In addition, younger patients, those with better overall health status, and those
cared for by a physician who worked part-time were significantly more likely to
report better satisfaction with both measures. Minority patients and those with
managed care insurance also reported lower overall satisfaction. CONCLUSIONS: The
patients of physicians who have higher professional satisfaction may themselves
be more satisfied with their care. Further research will need to consider factors
that may mediate the relation between patient and physician satisfaction.
PMID- 10672117
TI - Evidence-based medicine training in internal medicine residency programs a
national survey.
AB - To characterize evidence-based medicine (EBM) curricula in internal medicine
residency programs, a written survey was mailed to 417 program directors of U.S.
internal medicine residency programs. For programs offering a freestanding
(dedicated curricular time) EBM curriculum, the survey inquired about its
objectives, format, curricular time, attendance, faculty development, resources,
and evaluation. All directors responded to questions regarding integrating EBM
teaching into established educational venues. Of 417 program directors, 269 (65%)
responded. Of these 269 programs, 99 (37%) offered a freestanding EBM curriculum.
Among these, the most common objectives were performing critical appraisal (78%),
searching for evidence (53%), posing a focused question (44%), and applying the
evidence in decision making (35%). Although 97% of the programs provided MEDLINE,
only 33% provided Best Evidence or the Cochrane Library. Evaluation was performed
in 37% of the freestanding curricula. Considering all respondents, most programs
reported efforts to integrate EBM teaching into established venues, including
attending rounds (84%), resident report (82%), continuity clinic (76%), bedside
rounds (68%), and emergency department (35%). However, only 51% to 64% of the
programs provided on-site electronic information and 31% to 45% provided site
specific faculty development. One third of the training programs reported
offering freestanding EBM curricula, which commonly targeted important EBM
skills, utilized the residents' experiences, and employed an interactive format.
Less than one half of the curricula, however, included curriculum evaluation, and
many failed to provide important medical information sources. Most programs
reported efforts to integrate EBM teaching, but many of these attempts lacked
important structural elements.
PMID- 10672118
TI - Racial differences in the utilization of oral anticoagulant therapy in heart
failure: a study of elderly hospitalized patients.
AB - To assess racial differences in the use of oral anticoagulant therapy for
patients with heart failure, we conducted a cohort study of 30 hospitals in
northeast Ohio. For 12,911 Medicare enrollees consecutively admitted in 1992
through 1994 with heart failure, crude and adjusted odds of being on oral
anticoagulation were determined. The crude and adjusted odds of being African
Americans on oral anticoagulant therapy relative to whites were 0.57 (95%
confidence interval 0.47-0.69) and 0.55 (95% confidence interval 0. 45-0.67),
respectively. African-Americans with heart failure were much less likely than
whites to receive oral anticoagulant therapy, even after adjusting for other
variables associated with anticoagulant use.
PMID- 10672119
TI - Entering the electronic age: risks and challenges for JGIM.
PMID- 10672121
TI - Reflections
PMID- 10672120
TI - I can't get no patient or practitioner satisfaction.
PMID- 10672122
TI - Reflections
PMID- 10672123
TI - Journal of internal medicine and the new century.
PMID- 10672124
TI - Internal medicine in the 21st century. Introduction.
PMID- 10672125
TI - The educated patient: new challenges for the medical profession.
AB - The medical profession is facing significant changes in the way the rest of
society relates to it. Mass education, mass media and mass consumerism have
boomed in the 20th century, putting an increasing amount of pressure on
professionals to meet rising public expectations. If doctors are to continue to
provide a service that meets the demands of citizens and taxpayers, they need to
develop a new relationship with patients, acting not as instructors but as
guides, to help people make decisions about their own health. They will have to
be more accountable for the quality of care they provide and work with a wider
range of health and non-health professionals to meet patients' needs. Doctors
need not only to accept the consumer society but also, I will argue, to encourage
it. They can work to ensure that the benefits of the information revolution are
felt by people excluded from consumerism because of poverty and social isolation,
working to create an empowered, informed public whose members are given the best
opportunity to look after their own health.
PMID- 10672126
TI - Epidemics of vascular toxicity and pulmonary hypertension: what can be learned?
AB - Epidemics of vascular disease caused by toxins and infectious agents affecting
both humans and animals have been common in history. Examples of agents
implicated include anorexients, ergotamine, mercury, arsenic, vinyl chloride,
thorotrast, plant alkaloids, nitrites, toxic oil, tryptophan and bacterial, viral
and parasitic infections. A major characteristic of these disorders is
endothelial dysfunction, which may manifest itself in vasospastic disorders,
sclerodermiform skin lesions, fibrosis, osteolytic lesions, polyneuropathy and
portal and pulmonary hypertension. Angiosarcoma may also be a late outcome. These
diseases are more common than is generally appreciated. The aetiology is usually
multifactorial. This and other factors contribute to delayed recognition.
PMID- 10672127
TI - Long-term outcome of the Malmo preventive project: mortality and cardiovascular
morbidity.
AB - OBJECTIVES: To analyse the effects on mortality and cardiovascular morbidity in a
population-based sample, invited to an intervention programme incorporating a
baseline screening examination and treatment programmes for subjects with
cardiovascular risk factors, high alcohol intake and, in women, suspicion of
breast cancer on mammography. SETTING: Section of Preventive Medicine, Department
of Medicine, University Hospital, Malmo, Sweden. SUBJECTS: Birth cohorts (aged 32
51 years) invited to screening examination (men = 9. 923; women = 4.422) were
compared to birth cohorts not invited (men = 6.655; women = 4.290). Mean
participation rate in the invited cohorts was 71% (range 64-78%). SCREENING
EXAMINATION: Between 1974 and 1992 a baseline screening including a physical
examination, blood pressure, a questionnaire regarding, e.g. family history,
lifestyle, and socio-economic factors, laboratory tests of serum cholesterol,
triglycerides, gamma-glutamyl-transferase, blood glucose before and after an oral
glucose load, as well as a mammography examination in women, was performed.
INTERVENTIONS: Subjects with hypertension; hyperlipidaemia; diabetes or glucose
intolerance; high alcohol intake; or, in women, suspicion of breast cancer were
referred to special outpatient clinics. MAIN OUTCOME MEASURES: Total and cause
specific mortality, nonfatal myocardial infarction, and stroke, from the
screening examination until the end of 1995, was followed in both the
intervention and control groups, using national and/or local registries. RESULTS:
Total mortality did not differ significantly between the intervention group and
control group. Cause-specific deaths were also similar except for 'other' deaths
amongst men being significantly lower in the intervention group, mainly due to a
lower mortality from 'other' causes (suicide, alcohol related deaths) in men
under 40 years of age at baseline. Women under 40 years of age had a
significantly lower mortality from cancer in the intervention group than in the
control group. Nonfatal myocardial infarction and stroke did not differ between
intervention and control group in either sex. Within the invited birth cohorts,
nonparticipants had a higher total and cause-specific mortality. CONCLUSIONS:
Risk factor screening for major diseases such as cardiovascular disease, alcohol
abuse, diabetes mellitus and breast cancer, and subsequent treatment of the
detected risk factors/diseases - The Malmo Preventive Project - did not reduce
total mortality in the intervention group as a whole. In subjects under 40 years
of age at entry, total mortality was lower in the intervention group than in the
control group. In men, this seemed to be due to a reduction of alcohol-related
deaths, whilst in women death from cancer was reduced.
PMID- 10672128
TI - Meal pattern and risk factor evaluation in one-year completers of a weight
reduction program for obese men - the 'Gustaf' study.
AB - OBJECTIVES: To evaluate changes in meal patterns and in obesity related risk
factors after 1 year of treatment in obese men. DESIGN: Data from two 24-h
dietary recalls, performed at base-line and after 1 year of treatment, were
related to changes in medical risk factors. SETTING: Academic obesity unit.
SUBJECTS: Sixty-three men, aged 44 (eight) years (mean [SD]) and Base-line Body
Mass Index (BMI) 37.4 (4.6) kg m-2, who had completed 1 year of treatment. The
men were subdivided by tertiles according to weight change: tertile I (n = 21),
mean +0.3 kg, tertile II (n = 21), mean -5.8 kg and tertile III (n = 21), mean
14.2 kg. MAIN OUTCOME MEASURES: Weight loss, changes in meal patterns and in
obesity related medical risk factors. RESULTS: The reported mean energy intake
decreased after treatment in tertiles II and III by 700 (1300) kcal (P < 0.05)
and 700 (900) kcal (P = 0.001), respectively. In tertile III the energy-% from
fat decreased (P < 0.05) with a reciprocal increase in energy-% from protein (P <
0.05). The frequency of snacks of a low nutritional quality decreased (P < 0.01)
in tertile III together with an increase in energy-% from 'hot meals of good
quality' (P < 0.05). Obesity related risk factors (anthropometry, blood pressure,
serum lipid concentrations, blood glucose and plasma insulin) improved in a
beneficial way only in tertile III. CONCLUSIONS: The weight loss in the
successful tertile III men was to a great extent explained by fewer low quality
snacks but more energy from high quality meals. These changes reflected the
behaviour modification strategy recommended.
PMID- 10672129
TI - Relation between incidence of pneumonia and protective reflexes in post-stroke
patients with oral or tube feeding.
AB - OBJECTIVES: Although attenuated protective reflexes have been implicated in the
development of aspiration pneumonia, the relation between the incidence of
pneumonia and the state of these reflexes has not been investigated. Furthermore,
the role of feeding tube placement in preventing pneumonia in patients with
attenuated protective reflexes is unknown. We studied the relationship between
the incidence of pneumonia and the state of cough and swallowing reflexes in post
stroke patients with oral or tube feeding. DESIGN: The incidence of pneumonia was
prospectively analysed for 1 year in three groups of post-stroke patients on the
basis of the following clinical conditions: oral feeding without dysphagia (n =
43); oral feeding with dysphagia (n = 48); and nasogastric tube feeding with
dysphagia (n = 52). We also studied the incidence of pneumonia in bedridden
patients with nasogastric tube feeding (n = 14). Before the start of the study,
the swallowing and cough reflexes of each patient were measured. The swallowing
reflex was evaluated according to latency of response, which was timed from the
injection of 1 mL of distilled water into the pharynx through a nasal catheter to
the onset of swallowing. The cough threshold of citric acid aerosols was defined
as the concentration at which the patient coughed five times. RESULTS.;: The
incidence of pneumonia was observed in patients having both a latency of response
longer than 5 s and a cough threshold for citric acid higher than a concentration
of 1.35 (log mg mL-1). The incidence of pneumonia was significantly higher in
patients with oral feeding than in those with tube feeding (54.3 vs. 13.2%, P <
0.001). In bedridden patients with tube feeding, the latency of response was
longer than 20 s and no patient coughed at the highest concentration of citric
acid. The incidence of pneumonia was 64.3% in such patients. CONCLUSIONS: The
state of protective reflexes had a significant relation to the incidence of
pneumonia. Feeding tube placement may have a beneficial role in preventing
aspiration pneumonia in mildly or moderately disabled post-stroke patients with
attenuated protective reflexes. Bedridden patients who were tube-fed had the
highest incidence of pneumonia.
PMID- 10672130
TI - Plasma lipoprotein particle concentrations in postmenopausal women with unstable
coronary artery disease. Analysis of diagnostic accuracy using receiver operating
characteristics.
AB - BACKGROUND: The contribution of plasma lipids to cardiovascular risk is usually
evaluated by measuring plasma concentrations of total cholesterol, triglycerides
and HDL cholesterol, and calculating LDL cholesterol concentration. We
investigated plasma concentrations of apolipoproteins and lipoprotein particles
in women with unstable coronary artery disease (CAD) to evaluate whether these,
better than the routine lipid status, could differentiate women with and without
coronary atherosclerosis. METHODS: Blood samples for lipid analyses were
collected from 119 angiographically examined postmenopausal 49-79-year-old women
with unstable CAD, and from 101 age-matched controls. Mean plasma concentrations
were compared and the discriminatory ability of the different variables were
tested using receiver operating characteristics (ROC). RESULTS: At coronary
angiography 19% had normal vessels and 81% had coronary atherosclerosis. A
disturbed triglyceride metabolism was the most pronounced lipid abnormality in
women with unstable CAD and coronary atherosclerosis. ROC showed that none of the
evaluated variables had a particularly high discriminatory power regarding
unstable CAD or coronary atherosclerosis. The ratio cholesterol/HDL cholesterol
was best with an ROC area of 0.79. Furthermore, the newer lipid variables, i.e.
lipoprotein particles and apolipoproteins, were no better than the traditional
variables. CONCLUSION: Lipoprotein changes reflecting a disturbed triglyceride
metabolism are most pronounced in women with unstable CAD and coronary
atherosclerosis. Lipoprotein particles and apolipoproteins alone were no better
than lipids and lipoproteins in separating women with from those without coronary
atherosclerosis. Our study does not support the measurement of apolipoproteins
and lipoprotein particles on the basis of diagnostic accuracy alone.
PMID- 10672131
TI - Trends in lipid levels and hypercholesterolemia in hypertensive and normotensive
finnish adults from 1982 to 1997.
AB - OBJECTIVES: To assess the trends in lipid levels and awareness of
hypercholesterolemia in hypertensive and normotensive population in Finland from
1982 to 97. DESIGN: Four independent cross-sectional population surveys conducted
in 1982, 1987, 1992 and 1997. SETTING: The provinces of North Karelia and Kuopio
in eastern Finland and the region of Turku-Loimaa in south-western Finland.
SUBJECTS: Men and women aged 25-64 years, selected randomly from the national
population register. The subjects were classified to four groups according to
their blood pressure level and treatment status: normotensive, unaware
hypertensive, aware but not treated hypertensive and treated hypertensive. The
total number of participants was 24 083. MAIN OUTCOME MEASURES: We assessed the
mean serum total cholesterol and HDL cholesterol concentrations, the prevalence
of hypercholesterolemia (total cholesterol >/=6.5 mmol L-1 or the use of lipid
lowering drugs), the prevalence of a high ratio of total cholesterol to HDL
cholesterol (ratio >/=5) and the awareness of hypercholesterolemia amongst the
four study groups. RESULTS: Mean total cholesterol, the prevalence of
hypercholesterolemia and the prevalence of a high ratio of total to HDL
cholesterol decreased, whereas the awareness of hypercholesterolemia increased
significantly in all study groups. The decline in mean total cholesterol was
largest in treated hypertensive subjects of both sexes (13% in men, 14% in
women). Mean HDL cholesterol increased significantly in all study groups except
in the unaware hypertensive men, but it remained significantly lower in treated
hypertensive patients in both sexes compared with the other groups (P < 0.001).
CONCLUSIONS: The lipid profile of both the hypertensive and normotensive
population has significantly improved in both the hypertensive and normotensive
population in Finland from 1982-97. The introduction of newer antihypertensive
drugs has not had any effect on the HDL cholesterol level amongst treated
hypertensive patients at the population level.
PMID- 10672132
TI - Altered bone metabolism in inflammatory bowel disease: there is a difference
between Crohn's disease and ulcerative colitis.
AB - OBJECTIVES: The aims of this study were to assess bone metabolism in inflammatory
bowel disease (IBD) patients and to evaluate potential differences between
Crohn's disease (CD) and ulcerative colitis (UC) with respect to the mechanisms
underlying bone loss in this group of diseases. DESIGN AND SETTING: This was a
cross-sectional study which started in 1992. Patients were randomly selected for
invitation to participate and were examined during the years 1992-95 in one
research clinic in Milan. SUBJECTS AND METHODS: Fifty-one patients suffering from
CD (30 women and 21 men, mean age 38.7 +/- 13.2 years) and 40 with UC (15 women
and 25 men, mean age 34.4. +/- 12.5 years) entered the study. Thirty healthy
subjects were selected as sex- and age-matched controls (C). Spine and femoral
neck bone mineral density (expressed as T score), calciotropic hormones
(parathyroid hormone, PTH; 25-hydroxycholecalciferol, 25(OH)D3; 1,25
hydroxycholecalciferol, 1, 25(OH)D3) and biochemical markers of bone turnover
(ostecalcin, OC; total alkaline phosphatase, ALP; type I collagen C-terminal
telopeptide, ICTP) were evaluated. RESULTS: Spine and femur T scores were similar
in the two groups (spine: CD = -1.49 +/- 1.46; UC = -1. 67 +/- 1.13; femur: CD =
1.80 +/- 1.36; UC = -1.60 +/- 1.03). Based upon the WHO guidelines, only 8% of CD
patients and 15% of UC patients had a normal bone mineral density (BMD), 55% (CD)
and 67% (UC) were osteopenic, and 37% (CD) and 18% (UC) were osteoporotic. The
distribution amongst the three different diagnostic groups was not significantly
different between CD and UC groups (P = 0.11). PTH and 25(OH)D3 concentrations
were not significantly different between CD and UC patients and controls, whilst
1,25(OH)D3 concentrations were significantly lower in both CD and UC patients
compared with controls (P < 0.05). Bone turnover was increased in UC but not in
CD patients, as shown by significantly increased concentrations in UC patients of
both OC (CD = 7.77 +/- 5.06, UC = 10.03 +/- 6.24, C = 6. 58 +/- 2.87, P < 0.05
vs. C) and ICTP (CD = 5.74 +/- 3.94, UC = 10.2 +/- 8.47, C = 3.48 +/- 0.95, P <
0.05 vs. CD and C). In a stepwise regression that included age, sex, disease
duration and cumulative prednisolone dose as independent variables, the femur T
score was significantly inversely related to disease duration (r2 = 0.125, F =
6.06) in CD patients. In UC patients, the spine T score was inversely related to
age (r2 = 0.107, F = 5.49) and significantly related to sex (more negative in
males: r2 = 0.3, F = 16.1); the femur T score was significantly related to sex
(more negative in males) and inversely related to the cumulative prednisolone
dose (r2 = 0.283, F = 7.3). CONCLUSIONS: These data show that IBD patients have a
diffuse osteopenia, the degree of which is not different in CD and UC; however,
bone turnover is significantly higher in UC. Finally, osteopenia is related to
disease duration in CD, whilst it is related to the male sex and glucocorticoid
treatment in UC.
PMID- 10672133
TI - Angiotensin converting enzyme (ACE) gene polymorphism in sarcoidosis in relation
to associated autoimmune diseases.
AB - OBJECTIVES: To investigate the significance of ACE gene insertion/deletion (I/D)
polymorphism in the frequency of autoimmune manifestations in sarcoidosis.
DESIGN: In patients with sarcoidosis the ACE gene I/D polymorphism was detected
with PCR on genomic DNA. The patients with sarcoidosis were divided according to
the presence (n = 30) or absence (n = 32) of autoimmune manifestations. The
former group was subdivided into thyroid autoimmunity (n = 10), gluten immune
reactivity (n = 10) and gastric autoimmunity (n = 17). SETTINGS: The patients
were recruited at the Department of Pulmonary Medicine, and the study was
conducted at the Department of Endocrinology, University of Lund, Malmo
University Hospital, Malmo, Sweden. SUBJECTS: Sixty-two patients with documented
sarcoidosis (30 females, 32 males, median age/range at diagnosis of sarcoidosis
31.5/19-75 years, median age/range at study 47.5/22-81 years) were examined. A
total of 107 healthy unrelated subjects without sarcoidosis (60 females, 47
males, median age/range at study 58/40-82 years) served as controls. RESULTS: S
ACE values were significantly increased in patients compared to controls (P =
0.00001). The same was true in the subgroup of sarcoidosis patients with
associated autoimmunity compared with those with isolated sarcoidosis (P =
0.0328). A significant association was seen between ACE gene polymorphism (II,
ID, DD genotypes) and S-ACE levels in both patients and controls according to the
order II < ID < DD. The observed genotype frequency distributions in the
different study groups agreed the Hardy-Weinberg equilibrium without significant
differences between the patients and the controls. Within the group with
autoimmune manifestations the DD genotype was significantly over-represented in X
ray stage III compared to the other X-ray stages (P = 0.0181) and a significant
increase in the DD genotype in X-ray stage III (P = 0.035) in the group with
autoimmune manifestations compared to isolated sarcoidosis was detected.
CONCLUSION: We confirmed that the S-ACE levels corresponded to the order II < ID
< DD in patients with sarcoidosis as well as in healthy controls. S-ACE levels
were significantly higher in sarcoidosis patients with autoimmune manifestations.
The frequency of the DD genotype was significantly increased in patients with
autoimmune manifestations and major granuloma mass (X-ray stage III). The ACE D
allele in its homozygous form may confer susceptibility for autoimmune
manifestations in sarcoidosis, possibly via the high levels of S-ACE it encodes.
PMID- 10672134
TI - Hypomagnesemia in heart failure with ventricular arrhythmias. Beneficial effects
of magnesium supplementation.
AB - OBJECTIVE: To assess the role of electrolyte imbalance in cardiac arrhythmias
associated with congestive heart failure. DESIGN: Serum magnesium and potassium
levels, urine magnesium excretion and the incidence of ventricular arrhythmias
were assessed throughout the study. The patients who displayed complex
arrhythmias after the first week of hospital medication were randomized 2:1 to
double-blind magnesium supplementation or placebo. SETTING: The study was carried
out in one municipal hospital, providing primary care. SUBJECTS: A total of 588
consecutive patients were screened for eligibility (clinical heart failure >/=6
months; NYHA class II-IV; left ventricular ejection fraction =40%; sinus
rhythm; serum creatinine =2 mg dL-1). A total of 78 patients entered and 68
patients completed the study. INTERVENTIONS: Intravenous administration of
magnesium (magnesium sulphate 8 g in 250 mL of 5% glucose) or placebo (250 mL of
5% glucose) over 12 h. MAIN OUTCOME MEASURES: (i) Incidence of ventricular
arrhythmias in patients with hypomagnesemia; (ii) effects of magnesium
supplementation on ventricular arrhythmias. RESULTS: On admission, hypomagnesemia
was found in 38% and excessive magnesium loss in 72% of patients. Serum magnesium
levels were lower and urine magnesium excretion was greater in patients with
complex ventricular arrhythmias, both on admission and after treatment for heart
failure. Intravenous administration of magnesium caused a significant decrease in
the number of ventricular ectopic beats (P < 0.0001), couplets (P < 0.003) and
episodes of nonsustained ventricular tachycardia (P < 0.01). CONCLUSIONS:
Hypomagnesemia, probably related to increased urine magnesium excretion, is an
essential feature of heart failure associated with complex ventricular
arrhythmias. These arrhythmias can be alleviated/abolished by magnesium
supplementation.
PMID- 10672135
TI - Evaluation of a computer-based decision support system for treatment of
hypertension with drugs: retrospective, nonintervention testing of cost and
guideline adherence.
AB - OBJECTIVE: To evaluate a computerized decision support system (DSS) for drug
treatment of hypertension, regarding quality, safety, and cost compared to actual
antihypertensive drug treatment. DESIGN: The medical profiles of 338 hypertensive
patients treated with drugs against hypertension were processed by the DSS. The
drug treatment proposed by the system was then compared to actual treatment given
by their physician. SETTING: Four health centres in the county of Vasterbotten,
in Sweden. SUBJECTS: A list of hypertensive patients was extracted from the
computerized medical records of each health centre and every fifth patient's
medical profile was assessed by the system. INTERVENTIONS: None. MAIN OUTCOME
MEASURES: Drug used, drug used in relation to certain major diseases such as
diabetes mellitus, asthma, ischaemic heart disease (IHD), and previous myocardial
infarction. Adherence to hypertension guidelines, safety, and cost. RESULTS: The
DSS suggested significantly more thiazides and significantly fewer calcium
antagonists than the physicians had prescribed, with a total cost reduction of 33
40%, depending on doses chosen. The DSS drug profile was more adherent to
guidelines in patients with major complicating diseases, suggesting an
improvement in treatment quality for these patients by the DSS. CONCLUSION: The
DSS which fully implements current guidelines may improve the quality of
antihypertensive treatment, concurrently leading to a considerable reduction in
drug costs.
PMID- 10672136
TI - Randomized controlled trials and consensus as a basis for interventions in
internal medicine.
AB - OBJECTIVES: To estimate the proportion of routine clinical interventions in
internal medicine that are supported by the results of randomized controlled
trials or consensus amongst experienced internists. DESIGN: Retrospective review
of case records allowed one or more major diagnosis-intervention combination(s)
to be identified for each patient. The scientific literature was searched for
metaanalyses and randomized controlled trials in electronic databases that
supported the specific intervention used. When support from randomized trials was
lacking, possible consensus on management was sought by asking national expert
panels of experienced clinicians. SETTING: Department of Medicine at a Swedish
teaching hospital. SUBJECTS: At total of 197 consecutively admitted medical
inpatients. RESULTS: Fifty per cent of the diagnosis-intervention combinations
(186/369) were supported by results from randomized controlled trial evidence and
34% (125/369) were supported by consensus amongst experienced clinicians. The
proportion of interventions based on randomised controlled trials was highest in
patients with cardiac (64%) and other circulatory diagnoses (73%). There were no
important differences between sexes or between age groups. CONCLUSIONS: Half of
the interventions used in routine clinical practice amongst medical inpatients
are supported by results from randomized controlled trials. These results refute
popular claims that only a small proportion of medical interventions are
supported by scientific evidence.
PMID- 10672137
TI - Predicting the outcome of invasive treatment of renal artery disease.
AB - OBJECTIVE: Analysis of the factors influencing the outcome of performed or
attempted invasive treatment for renal artery disease (RAD). SETTING: University
Hospital. STUDY PATIENTS: Thirty-five hypertensive patients with 31 stenoses and
14 occlusions of renal artery. INTERVENTIONS: Angioplasty was performed on 25
patients (attempted for 30), primary stenting on one, nephrectomy on three, and
renal resection on one patient. MAIN OUTCOME MEASURE: A decrease of diastolic
blood pressure (DBP) by >/=15 mmHg after intervention. RESULTS: A DBP response
was seen in 24 patients. In 11 patients, invasive treatment did not result in a
DBP response or failed technically. Compared with these patients, the responders
were younger (55 +/- 11 vs. 66 +/- 8 years, P = 0.001) and tended to have higher
DBP (100 +/- 8 vs. 93 +/- 11 mmHg, P = 0.065). The function of the affected
kidney, or that of the more affected kidney if RAD was bilateral, was better
preserved in responders (relative clearance on captopril renography 23 +/- 15 vs.
8 +/- 4%, P = 0.008). A response was more often seen in unilateral than in
bilateral RAD (81% vs. 33%, P = 0.015). A relative clearance of =10% on
captopril renography had sensitivity of 88% and specificity of 81% for renal
artery occlusion. Step-wise logistic analysis. (1) When DBP was< 95 mmHg with two
antihypertensives, the response rate was 1/6 vs. 24/29 for more severe
hypertension (P = 0.004). (2) Elderly patients had a response rate of 2/5 vs.
22/24 in younger patients (P = 0.024). (3) Response rates in bilateral and
unilateral disease were not different, nor did the function of the affected
kidney impact the DBP response. However, three of the four responders with =10%
relative clearance had an occluded renal artery and underwent nephrectomy.
CONCLUSIONS: Middle-aged patients with easily controlled hypertension and elderly
hypertensives do not usually have a blood pressure response to the performed or
attempted invasive treatment of RAD. Therefore, it seems recommendable not to
screen such patients for RAD, unless their renal function is deteriorated. If the
affected kidney functions poorly on captopril renography, angioplasty is usually
not applicable and seldom leads to a blood pressure response.
PMID- 10672138
TI - Secular changes in cardiovascular risk factors over 30 years in Swedish men aged
50: the study of men born in 1913, 1923, 1933 and 1943.
AB - OBJECTIVES: To study secular trends in cardiovascular risk factors in men aged 50
over a period of 30 years. DESIGN: Cross-sectional studies of successive cohorts
of men from 1963 to 1993. SETTING: City of Goteborg, Sweden. SUBJECTS: Four
random population samples of men born in 1913, 1923, 1933 and 1943, aged 50 when
they were examined in 1963, 1973, 1983, and 1993 (n = 855, 226, 776, and 798,
respectively). MAIN OUTCOME MEASURES: Anthropometric measurements, blood
pressure, serum cholesterol and triglycerides and smoking habits over three
decades. RESULTS: Over 30 years, men increased in weight from a mean (SD) of 75.9
(11.0) kg to 82.8 (12.1) kg and gained 3.4 cm in height, with a net increase in
body mass index from 24.8 (3.2) to 26.0 (3.4) kg m-2 (P < 0.0001), and a
concomitant increase in waist circumference. The proportion of men who were
overweight but not obese (BMI = 25-30 kg m-2) increased from 38 to 47%, whereas
the prevalence of frank obesity (more than 30 kg m-2) increased from 6% in 1963
to 11% in 1993. Despite the increase in weight, mean systolic blood pressure fell
by almost 10 mmHg (P < 0.0001). Mean serum cholesterol concentration decreased
from 6.42 (1.12) to 5.88 (1.04) (P < 0.0001). Serum triglycerides increased from
1.26 (0.77) to 1.69 (1.04) mmol L-1 (P = 0.001). The proportion of men who smoked
decreased from 56% in 1963 to 30% in 1993 (P < 0.0001). This was due more to an
increase in smoking cessation rates than to an increase in the proportion of men
who had never smoked. In particular, smokers and former smokers are now more
obese than the corresponding categories 30 years ago and smokers are no longer
leaner than men who have never smoked. CONCLUSIONS: Over a period of 30 years,
serum cholesterol as well as systolic blood pressure and the prevalence of
smoking decreased. This favourable decline in coronary risk factors was offset by
an appreciable increase in body mass index and waist circumference.
PMID- 10672139
TI - Comparison of biochemical markers for the detection of minimal myocardial injury:
superior sensitivity of cardiac troponin--T ELISA.
AB - OBJECTIVES: Patients with minimal myocardial injuries who present clinically with
unstable angina, early stages of myocardial infarction or myocarditis require
different therapy strategies to those without. The newer diagnostic assays for
detecting myocardial lesions (cardiac Troponin T and cardiac Troponin I [cTnT,
cTnI], glycogenphosphorylase - BB [GPBB]) are reported to be more sensitive and
specific than common biochemical markers such as CK and myoglobin. Our study
tested whether the recently developed four assays cTnT-ELISA (in vitro), cTnT
rapid bedside assay, cTnI rapid bedside assay, and GPBB (Immunoenzymetric assay)
are effective in detecting minimal myocardial injuries caused by endomyocardial
biopsy. We compared them with CK activity (CK-cat), CK-MB activity (CK-MBcat), CK
MB-concentration (CK-MB-mass) and Myoglobin concentration (Myo-conc.). PATIENTS
AND METHODS: Twenty-four patients [six female, 18 male, age (mean): 47 years (20
65)] underwent diagnostic endomyocardial biopsy. Between four and six biopsies
were taken from the mid-right ventricular aspect of the interventricular septum
of the heart. Blood was drawn before catheterization (baseline), 10 min after the
biopsy, in the next morning, and in the morning of the second day after (days 1
and 2). RESULTS AND CONCLUSION: Because of very low CKcat it was not possible to
analyse CK-MBcat with reliable precision. The assay for GPBB and cTnI rapid
bedside assay did not indicate this minimal myocardial injury. The CK cat, CK-MB
mass, and myoglobin assays indicated significant increase at 10 min after biopsy
but remained within reference range. cTnT rapid bedside assay indicated this
minimal myocardial injury in 50% (P < 0.05). cTnT-ELISA (in vitro) was increased
above the reference limit in 54%. This increase was 3. 6-fold the upper reference
limit (P < 0.01). In our study, due to superior discriminating power, cTnT-ELISA
(in vitro) was the most sensitive assay for minimal myocardial injuries.
PMID- 10672140
TI - The distribution of two different vitamin D receptor polymorphisms (BsmI and
start codon) in primary hyperparathyroidism.
AB - INTRODUCTION: The bb genotype of the BsmI polymorphism of the vitamin D receptor
(VDR) is more common in primary hyperparathyroidism (HPT) than in the general
population in Swedish and German women. However, little is known about the
association of HPT with the start codon polymorphism of the VDR (defined by
FokI). OBJECTIVE: To study the distribution of the VDR genotypes in a group of
women with HPT compared with a control group. The bone mineral density (BMD) of
different genotypes was also investigated. METHODS: VDR alleles were typed by
polymerase chain reaction (PCR) assay around the polymorphic BsmI or FokI
restriction sites in 67 control women (48.5 +/- 10 years) and 53 women with HPT
(61.4 +/- 11 years). They were all Caucasian and born in the Canary Islands.
Lumbar and proximal femur BMDs were measured by dual X-ray absorptiometry (DXA)
and quantitative computed tomography (QCT). RESULTS: The 'bb' genotype was
equally frequent in controls and HPT subjects (46.3 and 45.3%, respectively).
There was a trend towards a lower prevalence of the FF genotype amongst women
with HPT as compared with controls (41.5 vs. 57.1%; P = 0.09). BMD was lower in
patients with HPT compared with controls in the lumbar spine and the proximal
femur. CONCLUSIONS: The association of the BsmI polymorphism of the VDR gene with
HPT is not applicable to all geographical areas. In Canarian postmenopausal women
suffering from HPT, VDR genotype distribution is similar to that found in
controls. A possible association of HPT with the FokI polymorphism deserves
further investigation.
PMID- 10672141
TI - Non-linear effects of blood pressure and glycosylated haemoglobin on progression
of diabetic nephropathy.
AB - OBJECTIVE: To describe the long-term simultaneous impacts of blood pressure and
glycosylated haemoglobin values on the risk of progression of diabetic
nephropathy. DESIGN: Prospective, multicentre, 6-year follow-up study. SETTING:
One reference centre (university department of internal medicine) and nine
general hospitals. SUBJECTS: A total of 601 type 1 diabetic patients on intensive
insulin therapy with and without diabetic nephropathy. MAIN OUTCOME MEASURES:
Progression of nephropathy was defined as change for the worse within five stages
of nephropathy by at least one of these stages during the study period. By the
use of logistic regression, the relationship between metabolic and blood pressure
control and the risk of nephropathy progression was quantified. RESULTS: The main
determinants of nephropathy progression were glycosylated haemoglobin and blood
pressure, which were both non-linearly associated with the risk of progression.
No significant threshold levels for any of the predictors of progression were
identified. CONCLUSIONS: The results of this study underline the importance of
optimizing metabolic and blood pressure control to arrest the progression of
diabetic nephropathy without the evidence for a clinically relevant threshold
effect.
PMID- 10672142
TI - LPA gene: interaction between the apolipoprotein(a) size ('kringle IV' repeat)
polymorphism and a pentanucleotide repeat polymorphism influences Lp(a)
lipoprotein level.
AB - OBJECTIVES: In order to search for factors influencing the Lp(a) lipoprotein
level, we have examined the apolipoprotein(a) (apo(a)) size polymorphism as well
as a pentanucleotide (TTTTA) repeat polymorphism in the 5' control region of the
LPA gene. DESIGN: Lp(a) lipoprotein levels were compared between individuals with
different genotypes as defined by pulsed field gel electrophoresis of DNA plugs,
and PCR of DNA samples followed by polyacrylamide gel electrophoresis. DNA plugs
and DNA were prepared from blood samples collected from blood donors. RESULTS:
Twenty-seven different K IV repeat alleles were observed in the 71 women and 92
men from which apo(a) size polymorphism results were obtained. Alleles encoding
26-32 Kringle IV repeats were the most frequent. Alleles encoding seven to 11
TTTTA repeats were detected in the 84 women and 122 men included in the
pentanucleotide polymorphism study, and homozygosity for eight TTTTA repeats was
the most common genotype. The eight TTTTA repeat allele occurred with almost any
apo(a) allele. An inverse relationship between number of K IV repeats and Lp(a)
concentration was confirmed. The contributions of the apo(a) size polymorphism
and the pentanucleotide repeat polymorphism to the interindividual variance of
Lp(a) lipoprotein concentrations were 9.7 and 3.5%, respectively (type IV sum of
squares). Nineteen per cent of the variance in Lp(a) lipoprotein level appeared
to be the result of the multiplication product (interaction) between the apo(a)
size polymorphism and the pentanucleotide repeat polymorphism. CONCLUSIONS: The
contribution of the apo(a) size polymorphism alone to the variation in Lp(a)
lipoprotein level was lower than previously reported. However, the multiplicative
interaction effect between the K IV repeat polymorphism and the pentanucleotide
repeat polymorphism may be an important factor explaining the variation in Lp(a)
lipoprotein levels among the populations.
PMID- 10672143
TI - Fatal hepatitis and renal failure during treatment with nimesulide.
AB - A healthy 70-year-old woman who took nimesulide for 5 days, presented 2 weeks
later with jaundice for which no other cause was found. Laboratory evidence of
coagulopathy, hypoalbuminaemia and hypoglycaemia were present on admission, and
liver biopsy showed massive necrosis of hepatocytes and severe inflammatory
infiltrate. Despite supportive and corticosteroid treatment, her jaundice
deepened and progressive acute renal failure developed, characterized by a
'prerenal' profile changing into irreversible acute tubular necrosis pattern,
coma, occult Gram-negative sepsis and death. Although rare, nimesulide-associated
hepatotoxicity and nephrotoxicity may occur and should be recognized as early as
possible, to ensure immediate drug withdrawal and treatment.
PMID- 10672144
TI - Pulp reactions to different preparation techniques on teeth exhibiting
periodontal disease.
AB - To evaluate the histopathological outcome of two preparation techniques
(featheredge preparation/shoulder preparation) on teeth exhibiting pulp reactions
due to age and periodontal disease, 11 teeth were prepared for full veneer
crowns. Laboratory made resin crowns were fixed with a zinc phosphate cement for
a period of 90 days. After extraction, adjacent pulpal areas were
histopathologically rated according to the BRD criteria comprising the parameters
(i) Bacterial invasion, (ii) Regenerative parameters, (iii) Degenerative
parameters. Degenerative reactions were more correlated with tooth preparation
than with advanced periodontal disease. The severity of endondontal reactions
depends more on remaining dentin thickness than on the type of preparation.
PMID- 10672145
TI - Effect of etching and sandblasting on bond strength to sintered porcelain of
unfilled resin.
AB - This study determined the bond strength of an unfilled resin joined to a
feldspathic porcelain for the purpose of evaluating the retentive performance of
the prepared material surfaces. Porcelain disks (VMK 68 dentin) were either air
abraded with alumina (AAA) or etched with one of the following five etchants: (1)
ammonium hydrogen bifluoride (AHB); (2) acidulated phosphate fluoride (APF); (3)
hydrofluoric acid (HFA); (4) phosphoric acid (PHA); and (5) sulfuric acid
hydrofluoric acid (SHF). Specimens ground with abrasive paper were also used as
controls. After surface preparation, the two different sized porcelain disks were
bonded together with a methyl methacrylate-based resin initiated with tri-n
butylborane (MMA-TBB resin). Shear bond strengths were determined both before and
after thermocycling. Before the thermocycling, the greatest bond strengths (21.3
and 23.7 MPa) were generated with the use of the SHF and HFA agents, followed by
the AHB agent (18.4 MPa). Reduction in bond strength after thermocycling was
significant for all groups, although the SHF- and HFA-treated groups exhibited
bond strengths greater than 15 MPa even after the thermocycling. The results
indicated the effectiveness of the SHF- or HFA-etching for retaining the acrylic
resin to the porcelain. However, ageing testing also revealed insufficient
retentive characteristics of the acrylic resin by etching alone.
PMID- 10672146
TI - The effect of interfacial failure around a class V composite restoration analysed
by the finite element method.
AB - Partial failure around the tooth-composite interface of a class V restoration is
common due to the effects of polymerization shrinkage. The effect that this has
on the force distribution of the remaining intact interfaces has not been
investigated. The aim of this study was to quantify the effect that partial
failure of an isolated cavity wall interface had on the force distribution around
the remaining intact interfaces of a class V composite restoration in a lower
first premolar using a two-dimensional plane strain finite element model. Partial
failure resulted in a 4-6-fold increase in peak tensile and shear forces compared
to a tooth with a fully intact cavity wall interface. In some instances, the peak
stresses were greater than the known bond strengths of composite to dentine.
PMID- 10672147
TI - The effect of polishing systems on microleakage of tooth coloured restoratives:
Part 1. Conventional and resin-modified glass-ionomer cements.
AB - The purpose of this in vitro study was to investigate the effect of polishing
systems on the microleakage of conventional and resin-modified glass-ionomer
cements. Class V cavities were prepared at the cemento-enamel junction of 80
freshly extracted posterior teeth. The prepared teeth were randomly divided into
two groups and restored with conventional or resin-modified glass-ionomer
cements. The restored teeth were stored in distilled water at 37 degrees C for 1
week after removal of excess restorative with diamond finishing burs. The
restored teeth were then divided into four groups of 10 and finished and polished
using the following systems: Two Striper MFS; Sof-Lex XT; Enhance Composite
Finishing and Polishing System; Shofu Composite Finishing Kit. The finished
restorations were subjected to dye penetration testing. Results showed that the
microleakage at dentin margins of conventional glass-ionomer cements and enamel
margins of resin-modified glass-ionomer cements are significantly affected by the
different polishing systems.
PMID- 10672148
TI - Interactions between thermal cycled resilient denture lining materials, salivary
and serum pellicles and Candida albicans in vitro. Part II. Effects on fungal
colonization.
AB - In the present study, the growth of a single isolate of Candida albicans on
saliva-, serum-coated or protein free (uncoated), thermocycled (4-70 degrees C
for 1 min, respectively; 0, 1000 and 10 000 times) seven commercial soft lining
materials were investigated, by adenosine triphosphate (ATP) analysis. In the
case of control resilient liners (not thermocycled and uncoated), the fungal
colonization appeared to depend upon the type of commercial resilient liner used.
Thus, the lowest colonization was observed with fluoric and heat-cured silicone
materials, cold-cured silicone materials, except for one product, and heat-cured
acrylic resin exhibited the highest colonization capacity, and cold-cured acrylic
resilient liners exhibited the intermediate. However, the fungal colonization on
the materials was significantly promoted both by thermal cycling (ANOVA, P<0.01)
and a layer of protein coating (saliva, P<0.01; serum, P<0.01). These results,
taken together, suggest that the ageing of the materials and the biological
fluids of the host promote yeast colonization on resilient lining materials.
PMID- 10672149
TI - Titanium for removable denture bases.
AB - The aim of the present study was to compare titanium-base and resin-base
maxillary complete dentures. In 13 patients with a maxillary complete denture
with a titanium base (group I) and in 12 patients with a maxillary complete
denture with a resin base (group II), the (a) patient's adaptation to the
denture, (b) denture retention and (c) appearance of the mucosa under the denture
were evaluated. In all cases, the adaptation was assessed with a questionnaire,
while the retention and the appearance of the mucosa were assessed by clinical
examination. None of the three measures considered (adaptation, retention and
mucosa appearance) differed significantly between patients with titanium-base
dentures and patients with resin-base dentures. Titanium bases are suitable for
dentures likely to be subject to severe mechanical stresses (as in the case of
maxillary complete dentures opposing natural teeth), and in patients who show
hypersensitivity responses to other materials.
PMID- 10672150
TI - Effects of acids and additives on the susceptibility of human dentine to
denaturation.
AB - The purpose of this study was to evaluate the efficacy of a number of additives
to acid conditioners at reducing the denaturation of dentine collagen. Dentine
collagen is normally not very susceptible to trypsin attack. After denaturation,
however, it becomes more susceptible to the action of trypsin. Slabs of human
dentine were dipped in water or acidic conditioners (10% citric acid or 37%
phosphoric acid) containing no additives, 5 or 10% NaCl, 3 or 6% ferric chloride
or 50% hydroxyethylmethacrylate (HEMA) for 15 or 60 s, followed by rinsing. The
slabs were then exposed to trypsin for 24 h to solubilize any denatured collagen.
The solubilized collagen was hydrolysed to liberate hydroxyproline that was
quantitated spectrophotometrically. The amount of hydroxyproline (HOP) liberated
was indicative of the amount of dentine collagen that was denatured by the test
solutions. The only additive that consistently reduced HOP release was 50% HEMA,
and this only occurred in the 60 s exposure group. Thus, the use of salt
additives to acidic conditioners has little protective effect.
PMID- 10672151
TI - The post-orthodontic prevalence of temporomandibular disorder and functional
occlusion contacts in surgical and non-surgical cases.
AB - This study aimed to assess mandibular mobility and the prevalence of functional
occlusal contacts in subjects treated to a Class 1 incisor relationship by fixed
orthodontic appliance therapy. Two hundred and thirty subjects participated (mean
age=18 years) of whom 42 underwent orthognathic surgery. All subjects were in
retention with a mean time of 7 months between debond and examination. Maximal
mandibular opening, lateral and protrusive excursions were all significantly
reduced in the surgical cases compared to the non-surgical group. Centric and
eccentric non-ideal occlusal contacts were not different between surgical and non
surgical groups. Non-working side contacts occurred in 30% of subjects, posterior
contacts on protrusion in 20% and RCP-ICP prematurities in 18% of subjects. Non
working side contacts were significantly more frequent in post-graduate cases
compared to staff cases (P<0.05). An overbite less than the mean of 2.4 mm
resulted in a reduced likelihood of canine guidance on the working side (P<0.001)
and an increased frequency of non-working side contacts and posterior contacts on
protrusion (P<0.001).
PMID- 10672152
TI - Effect of intrinsic and extrinsic moisture on bond strength to dentine.
AB - OBJECTIVES: The aim of this in vitro study was to investigate the effects of
simulated pulpal pressure (PP) and moist bonding (MB) on the shear bond strength
of three different dentine bonding systems (DBSs). METHODS: Dentine surfaces were
exposed on 120 extracted human molars and bonded with one out of three
restorative systems (A. R.T. Bond/Brilliant, OptiBond FL/Herculite XRV,
Scotchbond 1/Z100). In one-half of the specimens, the DBSs were applied under
hydrostatic pulpal pressure of 30 cm H2O (PP). Forty specimens were prepared for
each DBS according to the following experimental groups (each n=10): no PP/no MB;
with PP/no MB; no PP/with MB; with PP/with MB. Shear bond strengths after 24 h
were measured in a universal testing machine (Zwicki 1120) and statistically
analysed by 2-way ANOVA. Fractured surfaces were investigated for the type of
failure under an optical stereomicroscope and by SEM. RESULTS: In all DBSs,
pulpal pressure resulted in a decrease of dentinal bond strength. This effect was
significant in A.R.T. Bond and OptiBond FL (P<0.001), but not in Scotchbond 1
(P=0.060). Moist bonding significantly increased the bond strength of Scotchbond
1 (P<0.001), significantly decreased the bond strength of A.R.T. Bond (P=0.032),
but had no effect in the case of OptiBond FL (P=0.691). In A.R.T. Bond, the
combination of hydrostatic pulpal pressure and moist bonding resulted in complete
failure of most of the specimens prior to the debonding tests. The fracture
patterns as detected by SEM fracture analyses were typical for each DBS and
specific bonding condition and consistent with the results of the bond strength
measurements. SIGNIFICANCE: The results indicate that continuous intrinsic
moisture in the form of hydrostatic pulpal pressure adversely affects the
efficacy of DBSs, while limited extrinsic moisture by moist bonding is acceptable
or even essential. The effect of moist bonding on the efficacy of DBSs seems to
depend not only on the monomers used and the solvents per se, but also on the
water content of the dentine primer and the self-priming adhesive, respectively.
PMID- 10672153
TI - Investigation of a possible relationship between kinematic points and condylar
attachments of the lateral ligaments.
AB - Kinematic points are proposed as reference for assessment of condyle motion. They
are defined by coincidence between open-closing and protrusive trajectories.
According to anatomical findings, this feature should also apply to the condylar
attachment of the lateral ligament that should guide the condyle on an arc around
its tubercular fixation. Our aim was to examine if evidence for a correspondence
between the kinematic point and the condylar attachment of the ligament could be
derived from condylar dynamics. In 60 asymptomatic volunteers, open-closing and
protrusive jaw movements were recorded with 6 d.f. Kinematic points were found 2.
5+/-2.9 mm anterior and 4.3+/-2.9 mm inferior from the terminal-hinge point.
Their coinciding traces could be fitted by arcs with radii of 11.7+/-2.2 mm. The
centres of the arcs were found 10.4+/-1.6 mm anterior and 4.9+/-2.4 mm superior
from the kinematic points. When compared to anatomy, the local distributions of
kinematic points and arc centres corresponded well to the condylar and tubercular
fixation areas of the ligament. The findings provide circumstantial evidence for
a correspondence between kinematic points and the attachment of the lateral
ligament. Kinematic points could provide a better means to assess condyle motion
than other posterior landmarks, when in addition, movements of adjacent points
and rotational properties are considered.
PMID- 10672154
TI - Effect of eccentric clenching on mandibular deviation in the vicinity of
mandibular rest position.
AB - Although the mechanical compression of the temporomandibular joint (TMJ), which
could be caused by bruxism, would probably result in a slight change of the
occlusal relationship, the effect of clenching in the eccentric mandibular
position on the occlusal contact has not yet been clarified. This study aimed to
investigate the effect of eccentric clenching on bilateral condylar position and
thus to estimate any change of occlusal contact. Before and after voluntary
clenching, with one third of the maximal voluntary clenching force, for 3 min at
the canine edge-to-edge position, vertical deviation of the bilateral condyles
was measured at the 1 mm open mandibular position. This was regulated by the
three-dimensional position of the anterior reference point which stands for the
incisor point. The mean vertical displacement of the highly deviated side of the
condyle was 141+/-55 microm, and the calculated mean displacement of the
mandibular first molar region of the highly deviated side was 65+/-27 microm.
From the results of this study, it was revealed that the eccentric clenching gave
rise to three-dimensional deviation of the mandible even when the mandible was in
the vicinity of the rest position.
PMID- 10672155
TI - Hereditary sensory and autonomic neuropathy: review and a case report with dental
implications.
AB - Hereditary sensory and autonomic neuropathy (HSAN) is a rare syndrome which is
seen in early childhood. Five different types are described. Absence of pain and
self-mutilation are characteristic findings of this syndrome. Teeth in the oral
cavity can cause damage to the oral tissues and tongue. When it is diagnosed,
there should be co-operation between dentist and neurologist. Using an oral
shield prevents the biting and, thus, traumatization of the tissues can be
prevented. A case report which is diagnosed as HSAN type 4 is presented and
information submitted about its treatment.
PMID- 10672156
TI - Mating frequency and genetic structure of the Argentine ant Linepithema humile.
AB - The nest and population genetic structures of the Argentine ant, Linepithema
humile were investigated using eight microsatellite loci. Genotypes of the sperm
from spermathecae of 87 queens were consistent with all queens being singly
inseminated. The probability of a double mating remaining undetected was low
(0.012) suggesting that no queens or only a very low proportion mate multiply.
The relatedness between the queens and their mates was negative (R = -0.164 +/-
0.044) and significantly different to zero (P = 0.020). However, the high
negative relatedness value was caused by a significant allele frequency
difference between the sexes at a single locus (Lhum-28). When this locus was
removed from the analyses, the relatedness was not significantly different from
zero (R = 0.013 +/- 0.050, P = 0.812). Analysis of 10 nests revealed that the
genetic differentiation among nests was weak (FST = 0.003) and not
distinguishable from zero (P = 0.468). Similarly, the overall relatedness among
nestmate females was not significantly different from zero (R = 0.007 +/- 0.018,
P = 0.706). These results are consistent with the lack of distinct nest
boundaries and the large number of queens per nest in the population studied.
Although mating takes place inside the nest, the inbreeding coefficient was close
to zero (F = 0.007 +/- 0.025, P = 0.786). Overall, these data indicate
substantial local gene flow mediated by movement of reproductives among colonies.
PMID- 10672157
TI - A microsatellite-based estimation of clonal diversity and population subdivision
in Zostera marina, a marine flowering plant.
AB - We examined the genetic population structure in eelgrass (Zostera marina L.), the
dominant seagrass species of the northern hemisphere, over spatial scales from 12
km to 10 000 km using the polymorphism of DNA microsatellites. Twelve populations
were genotyped for six loci representing a total of 67 alleles. Populations
sampled included the North Sea (four), the Baltic Sea (three), the western
Atlantic (two), the eastern Atlantic (one), the Mediterranean Sea (one) and the
eastern Pacific (one). Microsatellites revealed substantial genetic variation in
a plant group with low allozyme diversity. Average expected heterozygosities per
population (monoclonal populations excluded) ranged from 0.32 to 0.61 (mean = 0.
48) and allele numbers varied between 3.3 and 6.7 (mean = 4.7). Using the
expected frequency of multilocus genotypes within populations, we distinguished
ramets from genetic individuals (i.e. equivalent to clones). Differences in
clonal diversity among populations varied widely and ranged from maximal
diversity (i.e. all ramets with different genotype) to near or total
monoclonality (two populations). All multiple sampled ramets were excluded from
further analysis of genetic differentiation within and between populations. All
but one population were in Hardy-Weinberg equilibrium, indicating that Zostera
marina is predominantly outcrossing. From a regression of the pairwise population
differentiation with distance, we obtained an effective population size Ne of
2440-5000. The overall genetic differentiation among eelgrass populations,
assessed as rho (a standardized estimate of Slatkin's RST) was 0.384 (95% CI 0.34
0.44, P < 0.001). Genetic differentiation was weak among three North Sea
populations situated 12-42 km distant from one another, suggesting that tidal
currents result in an efficient exchange of propagules. In the Baltic and in Nova
Scotia, a small but statistically significant fraction of the genetic variance
was distributed between populations (rho = 0.029-0. 053) at scales of 15-35 km.
Pairwise genetic differentiation between European populations were correlated
with distance between populations up to a distance of 4500 km (linear
differentiation-by-distance model, R2 = 0.67). In contrast, both Nova Scotian
populations were genetically much closer to North Sea and Baltic populations than
expected from their geographical distance (pairwise rho = 0.03-0.08, P < 0.01). A
biogeographical cluster of Canadian with Baltic/North Sea populations was also
supported using a neighbour-joining tree based on Cavalli-Sforza's chord
distance. Relatedness between populations may be very different from predictions
based on geographical vicinity.
PMID- 10672158
TI - The linkage disequilibrium between chloroplast DNA and mitochondrial DNA
haplotypes in Beta vulgaris ssp. maritima (L.): the usefulness of both genomes
for population genetic studies.
AB - The structure and evolution of the plant mitochondrial genome may allow recurrent
appearance of the same mitochondrial variants in different populations. Whether
the same mitochondrial variant is distributed by migration or appears recurrently
by mutation (creating homoplasy) in different populations is an important
question with regard to the use of these markers for population genetic analyses.
The genetic association observed between chloroplasts and mitochondria (i.e. two
maternally inherited cytoplasmic genomes) may indicate whether or not homoplasy
occurs in the mitochondrial genome. Four-hundred and fourteen individuals sampled
in wild populations of beets from France and Spain were screened for their
mitochondrial and chloroplast polymorphisms. Mitochondrial DNA (mtDNA)
polymorphism was investigated with restriction fragment length polymorphism
(RFLP) and chloroplast DNA (cpDNA) polymorphism was investigated with polymerase
chain reaction PCR-RFLP, using universal primers for the amplification. Twenty
and 13 variants for mtDNA and cpDNA were observed, respectively. Most exhibited a
widespread geographical distribution. As a very strong linkage disequilibrium was
estimated between mtDNA and cpDNA haplotypes, a high rate of recurrent mutation
was excluded for the mitochondrial genome of beets. Identical mitochondrial
variants found in populations of different regions probably occurred as a result
of migration. We concluded from this study that mtDNA is a tool as valuable as
cpDNA when a maternal marker is needed for population genetics analyses in beet
on a large regional scale.
PMID- 10672159
TI - Genetic diversity and gene flow among southeastern Queensland koalas
(Phascolarctos cinereus).
AB - Habitat fragmentation and destruction associated with the rapid urban and rural
development of southeast Queensland presents an immediate threat to the survival
of koala populations within this region. A sensitive method combining
heteroduplex analysis (HDA) with temperature gradient gel electrophoresis (TGGE)
was optimized to detect within-species variation in a mitochondrial DNA (mtDNA)
control-region fragment, approximately 670 bp in length, from the koala. Eight
different haplotypes were characterized in koalas, of which four were novel.
Analysis of mtDNA diversity in 96 koalas from five populations in southeast
Queensland revealed that the number of haplotypes in a single population ranged
from one to five, with an average within-population haplotype diversity of 0.379
+/- 0.016, and nucleotide diversity of 0.22 +/- 0.001%. Nucleotide divergence
between populations averaged 0.09 +/- 0.001% and ranged from 0.00 to 0.14%.
Significant genetic heterogeneity was observed among most populations, suggesting
that koala populations may be spatially structured along matrilines, although
this may not be universal. The limited distribution of the central phylogenetic
haplotype suggested the possibility of historical population bottlenecks north of
the Gold Coast, while the presence of two highly divergent haplotypes at the
Moreton site may indicate the occurrence of one or more undocumented
translocation events into this area.
PMID- 10672160
TI - Phylogeography of a post-glacial colonizer: Microtus longicaudus (Rodentia:
muridae).
AB - The molecular phylogeography of Microtus longicaudus was investigated with DNA
sequences of the mitochondrial cytochrome b gene. We used phylogenetic and
pairwise distance methods to reconstruct the history of the species with
particular emphasis on the Pacific Northwest. Genetic variation across the
species was consistent with vicariant events during the Pleistocene and
subsequent northern postglacial expansion following the receding Laurentide and
Cordilleran ice sheets. The largest break (> 6% uncorrected sequence divergence)
was found to exist between populations found southeast of the Colorado River
(eastern Arizona, Colorado, Wyoming and New Mexico) and all other western
populations. Other well-supported subclades were composed of samples from: (i)
the islands and north coast of southeast Alaska; (ii) eastern Alaska, British
Columbia, Washington and Oregon; and (iii) northern California, Idaho and
Montana. Within subclades, divergence was low. Our results suggest that the close
relationships among haplotypes within northern subclades are a result of recent
colonization, whereas higher among-subclade divergence is caused by genetic
differentiation during prolonged periods of isolation, possibly as a result of
mid-Pleistocene climatic events.
PMID- 10672161
TI - Species-specific oligonucleotide probes for macroalgae: molecular discrimination
of two marine fouling species of Enteromorpha (Ulvophyceae).
AB - The green seaweeds Enteromorpha intestinalis and E. compressa are important
fouling organisms commonly found in polluted and nutrient-enriched marine and
brackish water habitats, where they are used in environmental monitoring.
Discrimination of the two species is extremely difficult because of overlapping
morphological characters. In this study a quick molecular method for species
identification was developed based on the nuclear rDNA ITS2 sequence data of 54
E. intestinalis samples and 20 E. compressa samples from a wide geographical
range. Oligonucleotide probes were designed for species-specific hybridization to
dot-blots of the PCR-amplified ITS1, 5.8S gene and ITS2 fragment of both E.
intestinalis and E. compressa. Specificity of the oligonucleotide probes was
confirmed by tests with taxonomically diverse species that could morphologically
be confused with E. intestinalis or E. compressa. This is the first use of
species-specific probes for macroalgae. The restriction endonuclease NruI
digested specifically the amplified PCR product from E. compressa into two
fragments detectable on agarose gels, but no suitable restriction sites were
identifiable in the PCR product of E. intestinalis.
PMID- 10672162
TI - Sex ratio and fledging success of supplementary-fed Tengmalm's owl broods.
AB - A nest box population of Tengmalm's owls (Aegolius funereus) in northern Sweden
was studied to investigate the effects of extra food on the sex ratio between
hatching and fledging in this sexually size-dimorphic species. The brood size and
brood sex ratio of supplementary-fed and control broods were compared. Newly
hatched nestlings were blood sampled and sexed by polymerase chain reaction (PCR)
amplification of the sex-linked CHD1Z and CHD1W genes. The brood sex ratio at
hatching was strongly male biased (65%); this was also the case in broods where
all eggs hatched (72%). There was no relationship between hatch order and sex
ratio, and hatching sex ratio did not vary significantly with laying date. Brood
size decreased between hatching and fledging, but did not differ between fed and
control broods at either stage. Brood sex ratio did not differ between hatching
and fledging, and fledging sex ratio did not differ between fed and control
broods. It was concluded that, at least during the year in which the study was
carried out, feeding had no effect on brood reduction, and that male and female
nestlings did not show any differential mortality. The mechanisms behind the male
biased sex ratio at hatching, and any possible adaptive reasons for it, are not
known.
PMID- 10672163
TI - A phylogenetic analysis of body size evolution in the Anolis roquet group
(Sauria: Iguanidae): character displacement or size assortment?
AB - The important role that competition plays in structuring communities is well
documented; however, the role of competition in an evolutionary context remains
unclear. Evolutionary investigations into the role of competition have often
focused on the process of character displacement, and a good example of this is
the evolution of body size in the Anolis lizards of the Caribbean islands.
Previous work on the A. roquet species group has taken a phylogenetic approach
and concluded that patterns of body size differences are not caused by character
displacement but are a result of size assortment. Using a phylogenetic
reconstruction based on the sequence of the cytochrome b gene (cyt-b) and
ancestral character-state reconstruction methods, we investigated the roles of
character displacement and size assortment. Our results indicated that size
assortment alone was insufficient to explain the observed patterns of body size
differences. Furthermore, we found that change in body size was associated with a
change in allopatry/sympatry, thus supporting the character-displacement
hypothesis. We conclude that patterns of body size differences in the A. roquet
species group appear to be the result of a combination of character displacement
and size assortment because character displacement was only found to be possible
on three occasions.
PMID- 10672164
TI - Sex, parthenogenesis and genetic structure of rotifers: microsatellite analysis
of contemporary and resting egg bank populations.
AB - Cyclically parthenogenetic rotifers are a valuable model for investigating the
relationship between reproductive mode and population structure, although
advances in this field have been hindered by low allozyme variability in these
organisms. A high genotypic diversity is predicted after population
establishment, which would be eroded by clonal selection during the
parthenogenetic phase. The resting egg bank, produced sexually, is presumed to
store high levels of genetic diversity, with subsequent effects on planktonic
population structure. Here, we provide the first application of microsatellite
markers to a rotifer planktonic population and its associated resting egg bank.
Seven polymorphic microsatellite loci were screened in populations of the rotifer
Brachionus plicatilis in a temporary pond to analyse: (i) the genetic structure
of the resting egg bank; (ii) the changes in the genetic structure of rotifer
populations during the parthenogenetic phase; and (iii) the population structure
after its initiation from resting eggs. Microsatellites proved to be a useful
tool for clone identification, revealing a surprisingly high clonal diversity in
rotifer populations. The last sample in the parthenogenetic phase showed evidence
of clonal selection, as indicated by a low observed clonal diversity and the
appearance of linkage disequilibria. The resting egg bank, analysed
comprehensively for the first time in any zooplankter, is in Hardy-Weinberg and
linkage equilibrium, and contains a high genotypic diversity. Unexpectedly, the
resting egg bank differed from the planktonic population in its allelic
composition, suggesting that resting egg hatching is biased.
PMID- 10672165
TI - Screening of Mhc variation in Atlantic salmon (Salmo salar): a comparison of
restriction fragment length polymorphism (RFLP), denaturing gradient gel
electrophoresis (DGGE) and sequencing.
AB - We compared three different molecular methods currently used for screening of Mhc
variation in population studies of Atlantic salmon. Restriction fragment length
polymorphism (RFLP) of the entire class II gene detected 22 haplotypes. Seventeen
exon 2 sequences were obtained from individuals carrying the 22 haplotypes, two
of which had not been detected by RFLP. The six alleles (27%) detected by RFLP
and not by exon 2 sequencing probably resulted from sequence variation outside
exon 2. Within exon 2, RFLP differentiated 88% of the sequences. Alternatively,
denaturing gradient gel electrophoresis (DGGE) performed under two run conditions
detected 94% of the sequence variation. Both RFLP using different probes, and the
two PCR-based methods using three different primer pairs, suggest that there is
only a single Mhc class II B gene in the Baltic populations of Atlantic salmon.
PMID- 10672166
TI - Genetic divergence between Atlantic and Indo-Pacific stocks of bigeye tuna
(Thunnus obesus) and admixture around South Africa.
AB - Two mitochondrial DNA segments of the bigeye tuna (Thunnus obesus) were amplified
by polymerase chain reaction (PCR), and restriction fragment length polymorphism
(RFLP) analyses of these segments were used for the genetic stock study. The
variation in a segment flanking the ATPase and COIII genes was low; only two
genotypes (alpha and beta) were detected by RsaI digestion. Yet a large
difference in the genotype distribution was observed between ocean basin samples.
The alpha type predominated in four Atlantic samples, where 178 of 244
individuals were the alpha type. In contrast, only one of 195 individuals
collected in the Indo-Pacific was the alpha type? The frequency of the alpha type
varied considerably from 0 to 80% among seven samples collected off the Cape of
Good Hope. The variation found in the other segment, containing the D-loop
region, was much higher; two endonucleases (DpnII and RsaI) detected five
genotypes each and 15 composite genotypes. A highly significant difference in
genotype frequencies was observed between the Atlantic and Indo-Pacific samples,
but no heterogeneity was observed among the four Atlantic or among four Indo
Pacific samples. These results clearly indicate that not only gene flow, but also
fish migration, between the Atlantic and Indian Oceans are severely restricted,
and that fishes from these distinct stocks are intermingling around South Africa.
The simple and diagnostic genetic marker found in this study can be used to
estimate mixing ratios between Atlantic and Indian stocks around South Africa.
PMID- 10672167
TI - The use of random amplified polymorphic DNA (RAPD) markers to identify strawberry
varieties: a forensic application.
AB - The random amplified polymorphic DNA (RAPD) technique was applied to settle a
lawsuit involving unauthorized commercialization of a patented strawberry variety
of high economical relevance ('Marmolada'). Because of economical involvements,
the molecular approach was added to the more traditional morphological
examination in a double-blind test. All plants belonging to the patented variety
were unambiguously identified (13 plants among a total of 31 plants examined).
The results were accepted as evidence in the court. This study confirms that the
RAPD technique is especially suitable for identification of asexually reproduced
plant varieties for forensic or agricultural purposes.
PMID- 10672168
TI - Screening for intron-length polymorphisms in penaeid shrimps using exon-primed
intron-crossing (EPIC)-PCR.
PMID- 10672169
TI - Polymorphic microsatellites in the common cuttlefish Sepia officinalis
(Cephalopoda).
PMID- 10672170
TI - Development of tri- and tetranucleotide repeat microsatellite loci in Atlantic
cod (Gadus morhua).
PMID- 10672171
TI - Characterization of microsatellite loci in Sebastes alutus and their conservation
in congeneric rockfish species.
PMID- 10672172
TI - Highly polymorphic microsatellite markers in the white-lined bat (Saccopteryx
bilineata).
PMID- 10672173
TI - beta-1,6-Glucan synthesis in Saccharomyces cerevisiae.
AB - beta-1,6-Glucan is an essential fungal-specific component of the Saccharomyces
cerevisiae cell wall that interconnects all other wall components into a lattice.
Considerable biochemical and genetic effort has been directed at the
identification and characterization of the steps involved in its biosynthesis.
Structural studies show that the polymer plays a central role in wall structure,
attaching mannoproteins via their glycosylphosphatidylinositol (GPI) glycan
remnant to beta-1,3-glucan and chitin. Genetic approaches have identified genes
that upon disruption result in beta-1,6-glucan defects of varying severity, often
with reduced growth or lethality. These gene products have been localized
throughout the secretory pathway and at the cell surface, suggesting a possible
biosynthetic route. Current structural and genetic data have therefore allowed
the development of models to predict biosynthetic events. Based on knowledge of
beta-1,3-glucan and chitin synthesis, it is likely that the bulk of beta-1,6
glucan polymer synthesis occurs at the cell surface, but requires key prior
intracellular events. However, the activity of most of the identified gene
products remain unknown, making it unclear to what extent and how directly they
contribute to the synthesis of this polymer. With the recent availability of new
tools, reagents and methods (including genomics), the field is poised for a
convergence of biochemical and genetic methods to identify and characterize the
biochemical steps in the synthesis of this polymer.
PMID- 10672174
TI - A bacterial genome in flux: the twelve linear and nine circular extrachromosomal
DNAs in an infectious isolate of the Lyme disease spirochete Borrelia
burgdorferi.
AB - We have determined that Borrelia burgdorferi strain B31 MI carries 21
extrachromosomal DNA elements, the largest number known for any bacterium. Among
these are 12 linear and nine circular plasmids, whose sequences total 610 694 bp.
We report here the nucleotide sequence of three linear and seven circular
plasmids (comprising 290 546 bp) in this infectious isolate. This completes the
genome sequencing project for this organism; its genome size is 1 521 419 bp
(plus about 2000 bp of undetermined telomeric sequences). Analysis of the
sequence implies that there has been extensive and sometimes rather recent DNA
rearrangement among a number of the linear plasmids. Many of these events appear
to have been mediated by recombinational processes that formed duplications.
These many regions of similarity are reflected in the fact that most plasmid
genes are members of one of the genome's 161 paralogous gene families; 107 of
these gene families, which vary in size from two to 41 members, contain at least
one plasmid gene. These rearrangements appear to have contributed to a
surprisingly large number of apparently non-functional pseudogenes, a very
unusual feature for a prokaryotic genome. The presence of these damaged genes
suggests that some of the plasmids may be in a period of rapid evolution. The
sequence predicts 535 plasmid genes >/=300 bp in length that may be intact and
167 apparently mutationally damaged and/or unexpressed genes (pseudogenes). The
large majority, over 90%, of genes on these plasmids have no convincing
similarity to genes outside Borrelia, suggesting that they perform specialized
functions.
PMID- 10672175
TI - Acid- and multistress-resistant mutants of Lactococcus lactis : identification of
intracellular stress signals.
AB - Lactococcus lactis growth is accompanied by lactic acid production, which results
in acidification of the medium and arrest of cell multiplication. Despite growth
limitation at low pH, there is evidence that lactococci do have inducible
responses to an acid pH. In order to characterize the genes involved in acid
tolerance responses, we selected acid-resistant insertional mutants of the L.
lactis strain MG1363. Twenty-one independent characterized mutants were affected
in 18 different loci, some of which are implicated in transport systems or base
metabolism. None of these genes was identified previously as involved in
lactococcal acid tolerance. The various phenotypes obtained by acid stress
selection allowed us to define four classes of mutants, two of which comprise
multistress-resistant strains. Our results reveal that L. lactis has several
means of protecting itself against low pH, at least one of which results in
multiple stress resistance. In particular, intracellular phosphate and guanine
nucleotide pools, notably (p)ppGpp, are likely to act as signals that determine
the level of lactococcal stress response induction. Our results provide a link
between the physiological state of the cell and the level of stress tolerance and
establish a role for the stringent response in acid stress response regulation.
PMID- 10672176
TI - Genetic and biochemical evidence of a Campylobacter jejuni capsular
polysaccharide that accounts for Penner serotype specificity.
AB - Campylobacter jejuni, a Gram-negative spiral bacterium, is the most common
bacterial cause of acute human gastroenteritis and is increasingly recognized for
its association with the serious post-infection neurological complications of the
Miller-Fisher and Guillain-Barre syndromes. C. jejuni lipopolysaccharide (LPS) is
thought to be involved in the pathogenesis of both uncomplicated infection and
more serious sequelae, yet the LPS remains poorly characterized. Current studies
on C. jejuni suggest that all strains produce lipooligosaccharide (LOS), with
about one-third of strains also producing high-molecular-weight LPS (referred to
as O-antigen). In this report, we demonstrate the presence of the high-molecular
weight LPS in all C. jejuni strains tested. Furthermore, we show that this LPS is
biochemically and genetically unrelated to LOS and is similar to group II and
group III capsular polysaccharides. All tested kpsM, kpsS and kpsC mutants of C.
jejuni lost the ability to produce O-antigen. Moreover, this correlated with
serotype changes. We demonstrate for the first time that the previously described
O-antigen of C. jejuni is a capsular polysaccharide and a common component of the
thermostable antigen used for serotyping of C. jejuni.
PMID- 10672177
TI - Trypanosomes lacking trypanothione reductase are avirulent and show increased
sensitivity to oxidative stress.
AB - In Kinetoplastida, trypanothione and trypanothione reductase (TRYR) provide an
intracellular reducing environment, substituting for the glutathione-glutathione
reductase system found in most other organisms. To investigate the physiological
role of TRYR in Trypanosoma brucei, we generated cells containing just one
trypanothione reductase gene, TRYR, which was under the control of a tetracycline
inducible promoter. This enabled us to regulate TRYR activity in the cells from
less than 1% to 400% of wild-type levels by adjusting the concentration of added
tetracycline. In normal growth medium (which contains reducing agents),
trypanosomes containing less than 10% of wild-type enzyme activity were unable to
grow, although the levels of reduced trypanothione and total thiols remained
constant. In media lacking reducing agents, hypersensitivity towards hydrogen
peroxide (EC50 = 3.5 microM) was observed compared with the wild type (EC50 = 223
microM). The depletion of TRYR had no effect on susceptibility to melarsen oxide.
The infectivity and virulence of the parasites in mice was dependent upon
tetracycline-regulated TRYR activity: if the trypanosomes were injected into mice
in the absence of tetracycline, no infection was detectable; and when
tetracycline was withdrawn from previously infected animals, the parasitaemia was
suppressed.
PMID- 10672178
TI - Differential post-transcriptional regulation of yeast mRNAs in response to high
and low glucose concentrations.
AB - Glucose regulates yeast gene expression at both transcriptional and post
transcriptional levels. Glucose strongly represses the transcription of the
gluconeogenic genes, FBP1 and PCK1, and accelerates the degradation of their
mRNAs. Together these mechanisms are responsible for the rapid decrease in
gluconeogenic enzyme synthesis when yeast cells switch to glycolytic metabolism.
In this study, we show that accelerated gluconeogenic mRNA degradation can be
triggered by low concentrations of glucose (<0. 02%). This sets the FBP1 and PCK1
mRNAs apart from other glucose-sensitive mRNAs, such as the Ip mRNA, which only
responds to high glucose concentrations (>1%). We also show that accelerated
gluconeogenic mRNA degradation is co-ordinated with transcriptional repression by
common signalling components that include sugar kinases and Ras-cAMP signalling.
Furthermore, the ability of the low glucose signal to trigger accelerated
gluconeogenic mRNA degradation depends upon the low glucose sensor, Snf3p, but
not on the high glucose sensor, Rgt2p. Also, this response is influenced by reg1
and ume5 mutations, but not by grr1 or rgt1 mutations. Our data suggest that
several signalling pathways co-ordinate differential post-transcriptional and
transcriptional responses in yeast, depending upon the amount of glucose
available in the medium.
PMID- 10672179
TI - A genomic analysis of two-component signal transduction in Streptococcus
pneumoniae.
AB - A genomics-based approach was used to identify the entire gene complement of
putative two-component signal transduction systems (TCSTSs) in Streptococcus
pneumoniae. A total of 14 open reading frames (ORFs) were identified as putative
response regulators, 13 of which were adjacent to genes encoding probable
histidine kinases. Both the histidine kinase and response regulator proteins were
categorized into subfamilies on the basis of phylogeny. Through a systematic
programme of mutagenesis, the importance of each novel TCSTS was determined with
respect to viability and pathogenicity. One TCSTS was identified that was
essential for the growth of S. pneumoniaeThis locus was highly homologous to the
yycFG gene pair encoding the essential response regulator/histidine kinase
proteins identified in Bacillus subtilis and Staphylococcus aureus. Separate
deletions of eight other loci led in each case to a dramatic attenuation of
growth in a mouse respiratory tract infection model, suggesting that these signal
transduction systems are important for the in vivo adaptation and pathogenesis of
S. pneumoniae. The identification of conserved TCSTSs important for both
pathogenicity and viability in a Gram-positive pathogen highlights the potential
of two-component signal transduction as a multicomponent target for antibacterial
drug discovery.
PMID- 10672180
TI - The Brucella abortus Lon functions as a generalized stress response protease and
is required for wild-type virulence in BALB/c mice.
AB - The gene encoding a Lon protease homologue has been cloned from Brucella abortus.
The putative Brucella abortus Lon shares > 60% amino acid identity with its
Escherichia coli counterpart and the recombinant form of this protein restores
the capacity of an Escherichia coli lon mutant to resist killing by ultraviolet
irradiation and regulate the expression of a cpsB:lacZ fusion to wild-type
levels. A sigma32 type promoter was identified upstream of the predicted lon
coding region and Northern analysis revealed that transcription of the native
Brucella abortus lon increases in response to heat shock and other environmental
stresses. ATP-dependent proteolytic activity was also demonstrated for purified
recombinant Lon. To evaluate the capacity of the Brucella abortus Lon homologue
to function as a stress response protease, the majority of the lon coding region
was removed from virulent strain Brucella abortus 2308 via allelic exchange. In
contrast to the parent strain, the Brucella abortus lon mutant, designated GR106,
was impaired in its capacity to form isolated colonies on solid medium at 41
degrees C and displayed an increased sensitivity to killing by puromycin and
H2O2. GR106 also displayed reduced survival in cultured murine macrophages and
significant attenuation in BALB/c mice at 1 week post infection compared with the
virulent parental strain. Beginning at 2 weeks and continuing for 6 weeks post
infection, however, GR106 and 2308 displayed equivalent spleen and liver
colonization levels in mice. These findings suggest that the Brucella abortus Lon
homologue functions as a stress response protease that is required for wild-type
virulence during the initial stages of infection in the mouse model, but is not
essential for the establishment and maintenance of chronic infection in this
host.
PMID- 10672181
TI - A folding variant of alpha-lactalbumin with bactericidal activity against
Streptococcus pneumoniae.
AB - This study describes an alpha-lactalbumin folding variant from human milk with
bactericidal activity against antibiotic-resistant and -susceptible strains of
Streptococcus pneumoniae. The active complex precipitated with the casein
fraction at pH 4.6 and was purified from casein by a combination of anion
exchange and gel chromatography. Unlike other casein components, the active
complex was retained on the ion-exchange matrix and eluted only with high salt.
The eluted fraction showed N-terminal and mass spectrometric identity with human
milk alpha-lactalbumin, but native alpha-lactalbumin had no bactericidal effect.
Spectroscopic analysis demonstrated that the active form of the molecule was in a
different folding state, with secondary structure identical to alpha-lactalbumin
from human milk whey, but fluctuating tertiary structure. Native alpha
lactalbumin could be converted to the active bactericidal form by ion-exchange
chromatography in the presence of a cofactor from human milk casein,
characterized as a C18:1 fatty acid. Analysis of the antibacterial spectrum
showed selectivity for streptococci; Gram-negative and other Gram-positive
bacteria were resistant. The folding variant of alpha-lactalbumin is a new
example of naturally occurring molecules with antimicrobial activity.
PMID- 10672182
TI - The cell wall architecture of Candida albicans wild-type cells and cell wall
defective mutants.
AB - In Candida albicans wild-type cells, the beta1, 6-glucanase-extractable
glycosylphosphatidylinositol (GPI)-dependent cell wall proteins (CWPs) account
for about 88% of all covalently linked CWPs. Approximately 90% of these GPI-CWPs,
including Als1p and Als3p, are attached via beta1,6-glucan to beta1,3-glucan. The
remaining GPI-CWPs are linked through beta1,6-glucan to chitin. The beta1,6
glucanase-resistant protein fraction is small and consists of Pir-related CWPs,
which are attached to beta1,3-glucan through an alkali-labile linkage. Immunogold
labelling and Western analysis, using an antiserum directed against Saccharomyces
cerevisiae Pir2p/Hsp150, point to the localization of at least two differentially
expressed Pir2 homologues in the cell wall of C. albicans. In mnn9Delta and
pmt1Delta mutant strains, which are defective in N- and O-glycosylation of
proteins respectively, we observed enhanced chitin levels together with an
increased coupling of GPI-CWPs through beta1,6-glucan to chitin. In these cells,
the level of Pir-CWPs was slightly upregulated. A slightly increased
incorporation of Pir proteins was also observed in a beta1, 6-glucan-deficient
hemizygous kre6Delta mutant. Taken together, these observations show that C.
albicans follows the same basic rules as S. cerevisiae in constructing a cell
wall and indicate that a cell wall salvage mechanism is activated when Candida
cells are confronted with cell wall weakening.
PMID- 10672183
TI - The putative DNA translocase SpoIIIE is required for sporulation of the
symmetrically dividing coccal species Sporosarcina ureae.
AB - The spoIIIE gene of Sporosarcina ureae encodes a 780-residue protein, showing 58%
identity to the SpoIIIE protein of Bacillus subtilis, which is thought to be a
DNA translocase. Expression of the S. ureae spoIIIE gene is able to restore
sporulation in a B. subtilis spoIIIE mutant. Inactivation of the S. ureae spoIIIE
gene blocks sporulation of S. ureae at stage III. Within the limits of detection,
the sporulation division in S. ureae shows the same symmetry, or near symmetry,
as the vegetative division (in contrast to the highly asymmetric location of the
sporulation division for B. subtilis), and so it is inferred that SpoIIIE
facilitates chromosome partitioning during sporulation, even when the division is
not grossly asymmetric. It is suggested that chromosome partitioning lags behind
division during sporulation but not during vegetative growth.
PMID- 10672184
TI - Promoter discrimination by the related transcriptional activators MarA and SoxS:
differential regulation by differential binding.
AB - MarA and SoxS are closely related proteins ( approximately 45% identical) that
transcriptionally activate a common set of unlinked genes, resulting in multiple
antibiotic and superoxide resistance in Escherichia coli. Both proteins bind as
monomers to a 20 bp degenerate asymmetric recognition sequence, the 'marbox',
located upstream of the promoter. However, the proteins differ widely in the
extents to which they activate particular promoters, with the consequence that
overexpression of SoxS leads to greater superoxide resistance than does
overexpression of MarA. This 'discrimination' between activators by promoters was
demonstrated in vivo, using promoters fused to lacZ, and in vitro, using purified
RNA polymerase, promoter DNA and MarA or SoxS. The marbox was found to be a
critical element in discrimination by in vivo and in vitro assays of hybrid
promoters containing the marbox from one gene and the core promoter from another.
Furthermore, by sequential mutation of its marbox, a promoter that discriminated
35-fold in favour of SoxS was converted into one that did not discriminate. The
relative activation of a promoter by MarA or SoxS was paralleled by the relative
binding of the two activators to the promoter's marbox as assayed by band shift
experiments. Thus, differential recognition of closely related marbox sequences
by the closely related activators is the primary basis for promoter
discrimination. Discrimination enables the cell to customize its response to the
stresses that trigger synthesis of the activators.
PMID- 10672186
TI - BasT, a membrane-bound transducer protein for amino acid detection in
Halobacterium salinarum.
AB - Halophilic archaea, such as eubacteria, use methyl-accepting chemotaxis proteins
(MCPs) to sense their environment. We show here that BasT is a halobacterial
transducer protein (Htp) responsible for chemotaxis towards five attractant amino
acids. The C-terminus of the protein exhibits the highly conserved regions that
are diagnostic for MCPs: the signalling domain for communication with the
histidine kinase and the methylation sites that interact with the
methylation/demethylation enzymes for adaptation. Hydropathy analysis predicts an
enterobacterial-type transducer protein topology for BasT, with an extracellular
putative ligand-binding domain flanked by two transmembrane helices and a
cytoplasmic domain. BasT-inactivated mutant cells are missing a membrane protein
radiolabelled with L-[methyl-3H]-methionine in wild-type cells, confirming that
BasT is methylatable and membrane bound. Behavioural analysis of the basT mutant
cells by capillary and chemical-in-plug assays demonstrates complete loss of
chemotactic responses towards five (leucine, isoleucine, valine, methionine and
cysteine) of the six attractant amino acids for Halobacterium salinarum, whereas
they still respond to arginine. The volatile methyl group production assays also
corroborate these findings and confirm that BasT signalling induces methyl group
turnover. Our data identify BasT as the chemotaxis transducer protein for the
branched chain amino acids leucine, isoleucine and valine as well as for
methionine and cysteine. Thus, BasT and the arginine sensor Car cover the entire
spectrum of chemotactic responses towards attractant amino acids in H. salinarum.
PMID- 10672185
TI - Characterization of two novel regulatory genes affecting Salmonella invasion gene
expression.
AB - A Salmonella typhimurium chromosomal deletion removing approximately 19 kb of DNA
at centisome 65 reduces invasion of cultured epithelial cells as well as the
expression of lacZY operon fusions to several genes required for the invasive
phenotype. As the deleted region contains no genes previously known to affect
Salmonella invasion, we investigated the roles of individual genes in the deleted
region using a combination of cloning, complementation and directed mutation. We
find that the deletion includes two unrelated regulatory genes. One is the
Salmonella homologue of Escherichia coli barA (airS ), which encodes a member of
the multistep phosphorelay subgroup of two-component sensor kinases. The action
of BarA is coupled to that of SirA, a member of the phosphorylated response
regulator family of proteins, and includes both HilA-dependent and HilA
independent components. The other regulatory gene removed by the deletion is the
Salmonella homologue of E. coli csrB, which specifies a regulatory RNA implicated
in controlling specific message turnover in E. coli. These results identify a
protein that is likely to play a key role in the environmental control of
Salmonella invasion gene expression, and they also suggest that transcriptional
control of invasion genes could be subject to refinement at the level of message
turnover.
PMID- 10672187
TI - The response regulator RssB, a recognition factor for sigmaS proteolysis in
Escherichia coli, can act like an anti-sigmaS factor.
AB - sigmaS (RpoS) is the master regulator of the general stress response in
Escherichia coli. Several stresses increase cellular sigmaS levels by inhibiting
proteolysis of sigmaS, which under non-stress conditions is a highly unstable
protein. For this ClpXP-dependent degradation, the response regulator RssB acts
as a recognition factor, with RssB affinity for sigmaS being modulated by
phosphorylation. Here, we demonstrate that RssB can also act like an anti-sigma
factor for sigmaS in vivo, i.e. RssB can inhibit the expression of sigmaS
dependent genes in the presence of high sigmaS levels. This becomes apparent when
(i) the cellular RssB/sigmaS ratio is at least somewhat elevated and (ii)
proteolysis is reduced (for example in stationary phase) or eliminated (for
example in a clpP mutant). Two modes of inhibition of sigmaS by RssB can be
distinguished. The 'catalytic' mode is observed in stationary phase cells with a
substoichiometric RssB/sigmaS ratio, requires ClpP and therefore probably
corresponds to sequestering of sigmaS to Clp protease (even though sigmaS is not
degraded). The 'stoichiometric' mode occurs in clpP mutant cells upon
overproduction of RssB to levels that are equal to those of sigmaS, and therefore
probably involves binary complex formation between RssB and sigmaS. We also show
that, under standard laboratory conditions, the cellular level of RssB is more
than 20-fold lower than that of sigmaS and is not significantly controlled by
stresses that upregulate sigmaS. We therefore propose that antisigma factor
activity of RssB may play a role under not yet identified growth conditions
(which may result in RssB induction), or that RssB is a former antisigma factor
that during evolution was recruited to serve as a recognition factor for
proteolysis.
PMID- 10672188
TI - Homologous gene knockout in the archaeon Halobacterium salinarum with ura3 as a
counterselectable marker.
AB - To facilitate the functional genomic analysis of an archaeon, we have developed a
homologous gene replacement strategy for Halobacterium salinarum based on ura3,
which encodes the pyrimidine biosynthetic enzyme orotidine-5'-monophosphate
decarboxylase. H. salinarum was shown to be sensitive to 5-fluoroorotic acid (5
FOA), which can select for mutations in ura3. A spontaneous 5-FOA-resistant
mutant was found to contain an insertion in ura3 and was a uracil auxotroph.
Integration of ura3 at the bacterioopsin locus (bop ) of this mutant restored 5
FOA sensitivity and uracil prototrophy. Parallel results were obtained with a
Deltaura3 strain constructed by gene replacement and with derivatives of this
strain in which ura3 replaced bop. These results show that H. salinarum ura3
encodes functional orotidine-5'-monophosphate decarboxylase. To demonstrate ura3
based gene replacement, a Deltabop strain was constructed by transforming a
Deltaura3 host with a bop deletion plasmid containing a mevinolin resistance
marker. In one approach, the host contained intact ura3 at the chromosomal bop
locus; in another, ura3 was included in the plasmid. Plasmid integrants selected
with mevinolin were resolved with 5-FOA, yielding Deltabop recombinants at a
frequency of > 10-2 in both approaches. These studies establish an efficient new
genetic strategy towards the systematic knockout of genes in an archaeon.
PMID- 10672189
TI - A chromosomally encoded regulator is required for expression of the Yersinia
enterocolitica inv gene and for virulence.
AB - The primary invasion factor of Yersinia enterocolitica, invasin, is encoded by
inv. inv expression is regulated in response to pH, growth phase and temperature.
In vitro, inv is maximally expressed at 26 degrees C, pH 8.0, or 37 degrees C, pH
5.5, in early stationary phase. At 37 degrees C, pH 8.0, inv is weakly expressed.
To identify which gene(s) are required for inv regulation, we screened for
transposon insertions that decreased expression of an inv-'phoA chromosomal
reporter at 26 degrees C. Of 30 000 mutants screened, two were identified that
had negligible inv expression in all conditions tested. Both of these independent
mutants had an insertion into the same gene, designated rovA (regulator of
virulence). RovA has 77% amino acid identity to the Salmonella typhimurium
transcriptional regulator SlyA. Complementation with the wild-type rovA allele
restores wild-type inv expression as monitored by Western blot analysis, tissue
culture invasion assay and alkaline phosphatase assay. There is also a
significant decrease in invasin levels in bacteria recovered from mice infected
with the rovA mutant; therefore, RovA regulates inv expression in vivo as well as
in vitro. In the mouse infection model, an inv mutant has a wild-type LD50, even
though the kinetics of infection is changed. In contrast, the rovA mutant has
altered kinetics, as well as a 70-fold increase in the LD50 compared with wild
type. Furthermore, because the rovA mutant is attenuated in the mouse model, this
suggests that RovA regulates other virulence factors in addition to inv. Analysis
of other proposed virulence factors such as Ail, YadA and the Yop proteins shows
no regulatory role for RovA. The more severe animal phenotype combined with the
lack of impact on known virulence genes aside from inv suggests RovA regulates
potentially novel virulence genes of Y. enterocolitica during infection.
PMID- 10672190
TI - A NapC/NirT-type cytochrome c (NrfH) is the mediator between the quinone pool and
the cytochrome c nitrite reductase of Wolinella succinogenes.
AB - Wolinella succinogenes can grow by anaerobic respiration with nitrate or nitrite
using formate as electron donor. Two forms of nitrite reductase were isolated
from the membrane fraction of W. succinogenes. One form consisted of a 58 kDa
polypeptide (NrfA) that was identical to the periplasmic nitrite reductase. The
other form consisted of NrfA and a 22 kDa polypeptide (NrfH). Both forms
catalysed nitrite reduction by reduced benzyl viologen, but only the dimeric form
catalysed nitrite reduction by dimethylnaphthoquinol. Liposomes containing
heterodimeric nitrite reductase, formate dehydrogenase and menaquinone catalysed
the electron transport from formate to nitrite; this was coupled to the
generation of an electrochemical proton potential (positive outside) across the
liposomal membrane. It is concluded that the electron transfer from menaquinol to
the catalytic subunit (NrfA) of W. succinogenes nitrite reductase is mediated by
NrfH. The structural genes nrfA and nrfH were identified in an apparent operon
(nrfHAIJ) with two additional genes. The gene nrfA encodes the precursor of NrfA
carrying an N-terminal signal peptide (22 residues). NrfA (485 residues) is
predicted to be a hydrophilic protein that is similar to the NrfA proteins of
Sulfurospirillum deleyianum and of Escherichia coli. NrfH (177 residues) is
predicted to be a membrane-bound tetrahaem cytochrome c belonging to the
NapC/NirT family. The products of nrfI and nrfJ resemble proteins involved in
cytochrome c biogenesis. The C-terminal third of NrfI (902 amino acid residues)
is similar to CcsA proteins from Gram-positive bacteria, cyanobacteria and
chloroplasts. The residual N-terminal part of NrfI resembles Ccs1 proteins. The
deduced NrfJ protein resembles the thioredoxin-like proteins (ResA) of
Helicobacter pylori and of Bacillus subtilis, but lacks the common motif CxxC of
ResA. The properties of three deletion mutants of W. succinogenes (DeltanrfJ,
DeltanrfIJ and DeltanrfAIJ) were studied. Mutants DeltanrfAIJ and DeltanrfIJ did
not grow with nitrite as terminal electron acceptor or with nitrate in the
absence of NH4+ and lacked nitrite reductase activity, whereas mutant DeltanrfJ
showed wild-type properties. The NrfA protein formed by mutant DeltanrfIJ seemed
to lack part of the haem C, suggesting that NrfI is involved in NrfA maturation.
PMID- 10672191
TI - Ascaris lumbricoides infection is associated with protection from cerebral
malaria.
AB - Following reports of increased IgE in severe malaria and hypothesizing that
helminth coinfections could modify its outcome, we conducted a retrospective case
control study to establish whether helminths affect the evolution of Plasmodium
falciparum malaria. Some 182 severe cases, 315 mild controls and 40 controls with
circulating schizonts were examined for intestinal helminths. Comparing cerebral
malaria with mild controls, Ascaris lumbricoides was associated with a protective
adjusted odds ratio (OR) of 0.58 (0. 32-1.03) P = 0.06, for coinfection with
Ascaris and Necator americanus, OR = 0.39 (0.17-0.88) P = 0.02. Protection
followed a dose-effect trend (P = 0.008). When comparing cerebral malaria cases
and controls with circulating schizonts the OR was 0.25 (0.009-0.67) P = 0.006.
We hypothesized that Ascaris infected patients may have had decreased cyto
adherence, possibly through endothelial cell receptor downregulation and/or
decreased splenic clearance leading to the absence of selection of virulent P.
falciparum strains. IgE-anti-IgE immune complexes resulting from helminth
preinfection may have an important role in influencing clinical presentation of
severe malaria, and in establishing malaria tolerance, through the CD23/NO
pathway.
PMID- 10672192
TI - Secretion of IL-12 by murine macrophages activated by immunoglobulin receptor
mediated internalization of the surface coat of Trichinella spiralis larvae.
AB - Trichinella spiralis larvae incubated with a rabbit antiserum raised against the
larval surface coat bound murine macrophages to the parasite surface. Cell
binding was not observed without the antisurface coat serum, or with incubation
of larvae in normal rabbit serum, or with antibodies to keyhole limpet
haemocyanin which identify a cryptic T. spiralis larval antigen. Cell adherence
to the larval surface was lost by treatment of the cells with the lysosomotropic
drug primaquine, implicating a receptor-mediated mechanism. Cells adhering to the
parasite surface internalized parasite surface coat material, which was
subsequently concentrated into endosomes. Culture supernatants from these cells
contained enhanced levels of IL-12. Thus, the initial Th1 response to T. spiralis
infection may be explained by these data.
PMID- 10672193
TI - Costimulatory signal through CD86 is important in Th2 response in Trichinella
spiralis infected mice.
AB - In order to study the role of the costimulatory signals in Th2 cytokine
production, monoclonal antibodies (mAbs) against cell adhesion molecules (CAMs)
were added to cultured cells obtained from the mesenteric lymph nodes (MLNs) of
mice infected with Trichinella spiralis, followed by a determination of
interleukin (IL)-5 and IL-4 in the culture supernatant. IL-5 production by MLN
cells stimulated with somatic antigen was significantly reduced by addition of
anti-CD86 but not by anti-CD80 mAb. Combination of anti-CD80 and anti-CD86 mAbs
reduced IL-5 production most effectively. IL-4 production induced by anti-CD3 mAb
was suppressed only by the addition of anti-CD86 mAb. Blockade of the ICAM-1/LFA
1 and VCAM-1/VLA-4 interactions was less effective on the production of IL-5 and
IL-4 than the addition of anti-CD86 mAb alone. In contrast to the in vitro
cytokine production, intraperitoneal injection of anti-CD80, anti-CD86 mAb, or
both, similarly suppressed the peak of the eosinophilia on day 21. Elevation of
somatic antigen-specific IgE and IgG1 levels as well as total IgE was not
inhibited by the administration of anti-CD80, anti-CD86 mAb or both. In-vitro and
in-vivo effects of CTLA-4 immunoglobulin were similar to those of combined
treatment with anti-CD80 and anti-CD86 mAbs. These results suggest that the
interaction between antigen-presenting cells and CD4 T cells through CD86 are
most important in Th2 response during T. spiralis infection.
PMID- 10672195
TI - Relationship between parasite-specific antibody responses and intensity of
Opisthorchis viverrini infection in hamsters.
AB - The kinetics of parasite-specific antibody responses in relation to worm burden
and egg output were investigated in hamsters infected with 25, 50 and 100
Opisthorchis viverrini metacercariae (MC). Levels of antibody to egg, excretory
secretory (ES) and somatic antigens were examined by ELISA on days 1, 3, 7, 14
and month 1 postinfection (p.i.), and repeated monthly up to 6 months. The
antibody responses were first detected as early as 14 days after infection.
Hamsters that were infected with 100 MC and 50 MC showed higher antibody levels
than those of 25 MC, during early infection until 1 month p.i. Then, the antibody
levels were increased rapidly to a plateau at approximately month 2 p.i. and,
subsequently, were relatively stable in all groups. The average antibody levels
to egg and somatic, but not to ES antigens, were significantly higher in hamsters
infected with 25 MC than those of 50 MC and 100 MC. These antibody responses,
particularly to egg and ES antigens, were not correlated with worm burden or egg
output. Overall, higher antibody responses were found in the order: ES, somatic
and egg antigens. The significant lower antibody responses in chronic and heavy
infections than those with mild infection may a result of immunosuppression.
PMID- 10672194
TI - Vaccination of Manchego lambs against Haemonchus contortus with a somatic
fraction (p26/23) of adult parasites.
AB - A low molecular weight fraction from adult Haemonchus contortus containing two
peptides (p26/23) was used to vaccinate Manchego female lambs between 3.5 and 5
months of age. Immunizing injections were given three times on days 0, 14 and 28
of the experiment. On day 43, lambs were challenged with 400 third stage
larvae/kg live weight. Vaccination induced a lengthening of prepatent periods,
significant reduction (> 60%) in mean faecal egg counts and smaller variations in
packed cell volume values. At necropsy, average worm burden in the vaccinated
lambs was significantly lower (61.6%) than that found in unvaccinated challenged
animals. A clear correlation was found between protection and serum antibody
response in immunized lambs.
PMID- 10672196
TI - Fasciola hepatica infection downregulates Th1 responses in mice.
AB - Immune responses induced with helminth parasites have been extensively studied,
but there is limited information on those to Fasciola hepatica, especially on the
subtype of T cell induced with this parasite. We investigated the local and
systemic T cell responses of different strains of mice following oral infection
with doses of metacercariae from F. hepatica. Spleen cells from BALB/c and
129Sv/Ev mice given a low-dose (5 metacercariae) infection exhibited a Th2
response, producing high levels of the cytokines IL-4 and IL-5, and low levels of
IFN-gamma and IL-2. In contrast, C57BL/6 mice showed a mixed Th1/Th2 response. A
more marked polarization to a Th2 response was observed in BALB/c, 129Sv/Ev
exposed to a high-dose (15 metacercariae) infection and the C57BL/6 mice also
exhibited a clear Th2 response. IL-4 defective (IL-4-/-) C57BL/6 mice infected
with 5 metacercariae produced less IFN-gamma and more IL-5 compared to their wild
type C57BL/6 counterparts, suggesting that IL-4 is important in establishing the
Th2 type response in murine fasciolosis. However, the secretion of IFN-gamma and
IL-2 was completely suppressed in the high-dose infection and this was also
observed in IL-4-/- mice. Thus, liver flukes may secrete molecules that
downregulate Th1 responses. T cell responses in the mesenteric (MLN) and hepatic
lymph nodes (HLN) were also examined since newly excysted juveniles infect
through the intestinal wall of their host before migrating to the hepatic tissue.
Cells from both MLN and HLN secreted higher levels of IL-4 and IL-5 compared to
spleen cells. We also observed a difference in cytokine profiles secreted by the
MLN and HLN, which may reflect responses to antigens liberated by newly excysted
juveniles and hepatic stage parasites, respectively.
PMID- 10672197
TI - Interferon-gamma-independent CD8+ T cell-mediated protective anti-malaria
immunity elicited by recombinant adenovirus.
AB - Recombinant adenovirus, expressing the CS protein of Plasmodium yoelii, AdPyCS,
was shown to induce a comparable degree of T cell-mediated protection against
malaria as a single dose of irradiated P. yoelii sporozoites, causing inhibition
of liver stage development. We now report that differently from sporozoite
induced immunity, interferon (IFN)-gamma does not mediate the protective immunity
induced by AdPyCS, since a similar degree of protection was observed in AdPyCS
immunized mice lacking IFN-gamma-/- and the IFN-gamma receptor (IFN-gammaR-/-)
compared to that in wild-type mice. Depletion of CD8+ T cells from these
immunized mice almost completely abolished the AdPyCS-induced immunity,
indicating that the immunization with AdPyCS induces CD8+ T cell-mediated
protective anti-malaria immunity, which is independent of IFN-gamma.
PMID- 10672198
TI - Do we negotiate human health?
PMID- 10672199
TI - Reliability of malaria microscopy in epidemiological studies: results of quality
control.
AB - To assess the interrater reproducibility of malaria microscopy in epidemiological
studies, 711 thick blood films from population-based surveys were randomly
selected and reread by 4 experienced microscopists. Sample estimates of the
prevalence of P. falciparum infection, geometric mean parasite density and the
proportion of samples above various parasite density cut-off levels were almost
identical in the routine and quality control readings. Differences were, however,
encountered in the sample estimates for gametocyte ratio, proportion of mixed
infection and average density index. In all three cases the quality control
result was significantly higher than the routine evaluation. On the level of the
individual slide there was good interrater agreement for the presence of P.
falciparum infections (Kappa index kappa = 0.79) which was even better when
parasite densities between 4 and 100/microl were excluded (kappa = 0.94). With
respect to the assessment of parasite density, a high level of disagreement was
found. While the mean difference between the two readings was not different from
0, the second reading was between 0.12 and 10 times that of the first. However,
the level of disagreement significantly fell with increasing parasite densities.
Thus malaria microscopy is very reliable for the estimation of parasite ratios
and geometric mean parasite densities within and between studies as long as the
same methodology is used, but tends to underestimate the gametocyte ratio and
proportion of mixed infections. Care must be taken, however, when individual
parasite density is related to other explanatory variables, due to the high
degree of variability in the parasite enumeration.
PMID- 10672200
TI - Severe anaemia in Zambian children with Plasmodium falciparum malaria.
AB - BACKGROUND: Severe anaemia and cerebral malaria are highly prevalent
complications of Plasmodium falciparum malaria among African children. The
mechanisms of severe malarial anaemia, and the relative importance of this
condition in comparison to cerebral malaria, are not known for many regions of
Africa. METHODS We reviewed the records of 6200 children up to 6 years of age
admitted to one rural Zambian hospital between 1994 and 1996. Severe malarial
anaemia was defined as an haemoglobin concentration < 5.0 g/dl in a patient with
asexual forms of P. falciparum in the peripheral blood. Cerebral malaria was
defined as impaired consciousness (Blantyre coma score < 5) not attributable to
any other cause in a patient with a positive malaria smear. RESULTS Severe
malarial anaemia was found in 590 children (9.5% of paediatric admissions) and
strictly defined cerebral malaria occurred in 286 children (4.6% of paediatric
admissions); 98 of these patients had the combination of both complications.
Severe malarial anaemia correlated strongly with the degree of parasitaemia, with
malnutrition as indicated by low weight for age, with absence of fever and with
presentation late in the malaria season. In comparison, patients with cerebral
malaria were more often febrile and presented earlier in the malaria season. The
case fatality rate of severe malarial anaemia (0.088) was about half that of
cerebral malaria (0.189), but because severe malarial anaemia was more common,
these two forms of complicated malaria were implicated in similar numbers of in
hospital paediatric deaths. CONCLUSION Severe anaemia is a more common
complication of P. falciparum malaria in hospitalized Zambian children than
cerebral malaria and is associated with a similar number of deaths. Malnutrition
and changes in immune response patterns due to prolonged exposure to P.
falciparum may contribute to the development of this complication.
PMID- 10672201
TI - Malaria prevalence and a brief entomological survey in a village surrounded by
rice fields in Khammouan province, Lao PDR.
AB - We surveyed Nongceng, a village in a south-eastern province of Lao PDR, for
malaria and its vectors. Nongceng is situated in a basin and surrounded by rice
fields. In February 1998 (dry season), 28.6% of 126 villagers were infected with
malaria, and in September 1998 (rainy season), 16.3% of 147 villagers. The
prevalence of malaria infection was consistently high in children under 10, and
the predominant malaria species was Plasmodium falciparum. In brief surveys of
the mosquitoes performed on the same day as the malaria surveys, 2007 Anopheles
females from 12 species were collected by means of human bait, animal bait and
resting collections. Of the vector species known to be important in transmitting
malaria in neighbouring Thailand - An. minimus, An. dirus, and An. maculatus
groups - only An. minimus was found. Its density was, however, very low in both
seasons and it was therefore unlikely to be the vector. In fact, An. nivipes
accounted for more than 65% of all mosquitoes collected and was the most common
species collected from human baits. The results of this study show that endemic
areas of malaria in Lao PDR are not necessarily related to forest. Rather, An.
nivipes is suspected to be the most important vector.
PMID- 10672202
TI - Domestic hygiene and diarrhoea - pinpointing the problem.
AB - Improving domestic hygiene practices is potentially one of the most effective
means of reducing the global burden of diarrhoeal diseases in children. However,
encouraging behaviour change is a complex and uncertain business. If hygiene
promotion is to succeed, it needs to identify and target only those few hygiene
practices which are the major source of risk in any setting. Using biological
reasoning, we hypothesize that any behaviours which prevent stools from getting
into the domestic arena, the child's main habitat, are likely to have a greater
impact on health than those practices which prevent pathogens in the environment
from being ingested. Hence safe stool disposal, a primary barrier to
transmission, may be more important than hand-washing before eating, which
constitutes a secondary barrier, for example. We review the epidemiological
evidence for the effect of primary and secondary barrier behaviours and suggest
that it supports this conclusion. In the absence of local evidence to the
contrary, hygiene promotion programmes should give priority to the safe disposal
of faecal material and the adequate washing of hands after contact with adult and
child stools.
PMID- 10672203
TI - Validity of data-derived algorithms for ascertaining causes of adult death in two
African sites using verbal autopsy.
AB - background Verbal autopsy (VA) is used to ascertain causes of death using
information obtained from bereaved relatives. Causes of death can be ascertained
from VA questionnaires by a panel of physicians or from predefined algorithms. In
a previous study, we developed data-derived algorithms using VA data from 796
adult deaths in hospitals in Tanzania, Ethiopia, and Ghana (primary sites). These
computerized algorithms accurately estimated the cause-specific mortality
fractions (CSMFs) for deaths due to injuries, meningitis, TB/AIDS and diarrhoeal
diseases in the primary sites. Since the same data were used to generate and to
validate the algorithms, the accuracy of our algorithms may have been
overestimated. We report here on the validity of the algorithms when they were
applied to VA data from two secondary sites in Ghana and Tanzania. Here,
'validity' is taken to mean the degree to which the algorithms replicated the
physician-generated CSMF for major causes of death, when applied to the same VA
data. methods VA interviews were conducted in two secondary sites: in Navrongo,
Ghana, on 406 adult deaths, where three local physicians independently reviewed
the questionnaires and assigned a cause of death. In Morogoro, Tanzania, VA
interviews were conducted on 209 adult deaths, and a panel of physicians
independently reviewed the VA questionnaires together with the hospital death
certificates or hospital records to determine the cause of death. The CSMF
obtained using each algorithm was compared with the CSMF obtained using physician
review. results For injuries and meningitis, the algorithms and physician review
estimated a similar CSMF in the Morogoro and Navrongo data. For TB/AIDS, the
algorithm estimated a similar CSMF as the physicians in Morogoro. The algorithm
for diarrhoeal diseases did not agree closely with the physicians in Morogoro or
Navrongo. conclusions In general, our data-derived algorithms for assigning
causes of death due to injuries, meningitis, and TB/AIDS estimated a similar CSMF
as the physicians in the secondary sites. Recommendations for further validation
and refinement are discussed. Computerized algorithms offer a potentially quick,
affordable, and feasible method for assigning causes of death in mortality
surveillance or studies using VA.
PMID- 10672204
TI - HIV heterogeneity and proximity of homestead to roads in rural South Africa: an
exploration using a geographical information system.
AB - objective To describe heterogeneity of HIV prevalence among pregnant women in
Hlabisa health district, South Africa and to correlate this with proximity of
homestead to roads. methods HIV prevalence measured through anonymous
surveillance among pregnant women and stratified by local village clinic.
Polygons were created around each clinic, assuming women attend the clinic
nearest their home. A geographical information system (GIS) calculated the mean
distance from homesteads in each clinic catchment to nearest primary (1 degrees )
and to nearest primary or secondary (2 degrees ) road. results We found marked
HIV heterogeneity by clinic catchment (range 19-31% (P < 0.001). A polygon plot
demonstrated lower HIV prevalence in catchments remote from 1 degrees roads. Mean
distance from homesteads to nearest 1 degrees or 2 degrees road varied by clinic
catchment from 1623 to 7569 m. The mean distance from homesteads to a 1 degrees
or 2 degrees road for each clinic catchment was strongly correlated with HIV
prevalence (r = 0.66; P = 0.002). conclusions The substantial HIV heterogeneity
in this district is closely correlated with proximity to a 1 degrees or 2 degrees
road. GIS is a powerful tool to demonstrate and to start to analyse this
observation. Further research is needed to better understand this relationship
both at ecological and individual levels, and to develop interventions to reduce
the spread of HIV infection.
PMID- 10672205
TI - Acceptance and use of communal filtration units in guinea worm eradication.
AB - The use of cloth to filter drinking water for guinea worm prevention is a long
standing control strategy and part of a mixed approach that includes the
provision of wells, chemical treatment of ponds and protection of water supplies.
As the goal of eradication nears, filters are a useful component of the quick
response needed to implement case containment at village level. Various designs
of filters have been used. Individual hand-sewn filters (HSFs) using monofilament
nylon cloth have played a central role in village-based control to date. Problems
such as the need to continually reinforce correct habitual filtering behaviour
have led to the design and testing of communal filtration units (CFUs) made from
metal oil drums with filter cloth inserted in the top and spigots at the bottom.
Approximately one year after the introduction of CFUs in the South-western Zone
of Nigeria, village surveys were conducted to determine opinions about the two
types of filters and reported use. Percentage use was calculated by dividing the
number of times water was filtered in the week preceding the survey by the number
of times water was collected in that week. Those respondents with access to CFUs
filtered an average of 91.9% of the time compared to 75.7% of those with HSFs.
Using the village as level of analysis since it was the main level of
intervention, the average percent of times villagers in CFU villages filtered was
91.1% compared to 77.8% in HSF villages. Although CFUs were more expensive in the
short run, their greater acceptance by villagers is a factor to recommend their
wider implementation to speed up elimination of guinea worm from Nigeria.
PMID- 10672206
TI - Control of urinary schistosomiasis: an investigation into the effective use of
questionnaires to identify high-risk communities and individuals in Niger State,
Nigeria.
AB - Schistosomiasis is a public health problem in Nigeria. Although there is a
national programme for its control, there is the need for reliable and simple
means of rapidly diagnosing communities to provide a detailed map on the
distribution of the disease in the country, in order to prioritize control
activities, as well as to monitor the effectiveness of control operations. A
rapid assessment technique using school questionnaires was tested in Borgu Local
Government Area (LGA), Niger State, north-western Nigeria. Following a series of
focus group discussions, the questionnaires were adapted before they were
administered through the school system to 60 primary schools in Borgu LGA.
Correctly completed questionnaires were returned from 58 schools (97%) within 4
weeks. Questionnaires were validated by reagent stick tests performed by trained
teachers. Their results proved to be reliable compared to those obtained by our
research team in 20 randomly selected schools. Overall prevalences of
microhaematuria at 1+ and 2+ levels were 45.7% and 27. 1%, respectively. Highly
significant correlations were obtained between school prevalence of
microhaematuria and reported schistosomiasis, as well as reported blood in urine.
The diagnostic performance of the questionnaires at the 2+ level of
microhaematuria was very good. The design of our study also allowed data analysis
on an individual level, and multivariate analysis revealed highly significant
odds ratios for reported schistosomiasis and reported blood in urine to detect an
individual with urinary schistosomiasis. Our results are in good agreement with
reports from other African countries, and questionnaires can be recommended for
rapid identification of communities at highest risk of urinary schistosomiasis in
Nigeria, so that scarce resources of the national control programme can be used
most effectively.
PMID- 10672207
TI - Development of rapid assessment procedures for the delimitation of lymphatic
filariasis-endemic areas.
AB - Lymphatic filariasis caused by Wuchereria bancrofti is a major public health
problem in 73 tropical and subtropical countries including India. Delimitation of
endemic areas is essential to plan control operations. The current method of
night blood survey (NBS) for delimitation is cumbersome, time-consuming and
expensive. Therefore, there is a need to develop assessment procedures which can
rapidly delimit endemic areas. For this purpose we evaluated three procedures:
direct interviewing of key informants using structured questionnaires, an
indirect method of a self-administered questionnaires to key informants and
physical examination by health workers for the presence of chronic filarial
disease. Thirty rural communities in a filariasis-endemic region in Cuddalore
district in Tamil Nadu State in southern India constituted the study population.
The determination of filariasis endemicity in the village communities assessed by
the above procedures was compared in terms of rapidity, specificity, sensitivity
and cost with the microfilaria rate and disease rate obtained by night blood
sample survey and clinical examination by physicians. Prevalence score, control
preference score and weighted mean number of cases with filarial disease per
village were calculated using the key informant questionnaire techniques. While
the prevalence and control preference score showed low sensitivity and moderate
specificity, weighted mean number of cases showed high sensitivity and moderate
specificity in identifying endemic villages. The prevalence of disease as
determined by the physical examination of a sample population by health workers
was highly sensitive in identifying communities endemic for filariasis. The
degree of association between the disease rates estimated by physician and
trained health workers was significant (r = 0.56; P < 0.05). These observations
suggest that the weighted mean number of cases per village obtained through key
informant techniques may be considered at a primary level to crudely identify
endemic areas, followed by physical examination by health workers for filariasis,
since it is relatively cheap and rapid.
PMID- 10672208
TI - Detection of praziquantel resistance in schistosomes.
PMID- 10672209
TI - [Diversity of feeding behavior of Glossina palpalis palpalis in the forest belt
of the Ivory Coast: relation to the prevalence of human African trypanosomiasis].
AB - The feeding habits of Glossina palpalis palpalis, the main vector of human
African trypanosomiasis (HAT) were retrospectively analysed using data collected
between 1984 and 1994 in five areas in the forest belt in the mid-west of Cote
d'Ivoire. The authors compare the feeding habits of the vector in these different
foci. This analysis is aimed at determining if there is any relationship between
the feeding pattern of tsetse-flies and the prevalence rates of HAT. The feeding
pattern was measured using two indices: the conventional index of Shannon and
Weaver (Ish) and a new one, the zoophily/anthropophily index (Za). The latter is
an estimate of the ratio of the percentage of animal blood meals divided by the
percentage of human blood meals. There was no correlation between apparent
density and prevalence rate. A high Ish and a high Za were observed in the foci
of Vavoua, Zoukougbeu and Sinfra where prevalence rates of HAT were high.
Conversely, a low Ish and a low Za were observed in the hypoendemic areas of
Daniafla and Gagnoa. Both indices are highly but not significantly correlated
with prevalence rates. The Za index seemed to be more strongly correlated to the
disease rate as compared to the Ish index. The epidemiological significance of
these observations is discussed.
PMID- 10672210
TI - Vertical dimension is a compounding problem.
PMID- 10672211
TI - Eruption Guidance Appliance effects in the treatment of Class II, Division 1
malocclusions.
AB - The objective of this research was to cephalometrically evaluate the possible
effects of the Eruption Guidance Appliance on the craniofacial complex in a
sample of 30 patients, over a treatment period of 26 months. The experimental
sample consisted of 30 patients (13 females and 17 males), 27 of which presented
with a Class II, Division 1 malocclusion and 3 with a Class I malocclusion. The
mean initial chronologic age was 9 years; the treatment period lasted 26 months.
A control group was used for comparison and consisted of 30 subjects (13 females
and 17 males) of similar ages and spanned a similar observation period. Twenty
six subjects of this control group had Class II, Division 1 malocclusions, and 4
had Class I malocclusions. Lateral cephalometric headplates were obtained for the
experimental group initially and after 26 months of treatment. The subjects in
the control group were randomly selected from a serial growth study sample from
the Orthodontic Department at Bauru Dental School, University of Sao Paulo, for
whom cephalometric headplates were obtained annually from 4 to 18 years of age.
Comparative statistics were used to assess possible differences between the
experimental and control groups during the 26-month period of observation.
Results demonstrated statistically significant increases in mandibular growth,
degree of mandibular protrusion, lower anterior and total anterior face height,
mesial migration of the lower molars, and mandibular posterior dentoalveolar
height. There was also lingual tipping and retrusion of the upper incisors,
linear protrusion of the lower incisors, improvement in the maxillomandibular
relationship and in molar relationship, as well as a significant decrease in the
overjet and overbite and an inhibition of the vertical development of the upper
incisors. The study demonstrated no significant changes in maxillary growth
during the evaluation period. It was concluded from these results that the
effects of the Eruption Guidance Appliance during this time period were mostly
dentoalveolar, with a smaller, but significant, skeletal effect.
PMID- 10672212
TI - Two-year follow-up of distraction osteogenesis: its effect on mandibular ramus
height in hemifacial microsomia.
AB - Distraction osteogenesis has been used to lengthen the mandible in patients with
hemifacial microsomia. Questions regarding soft tissue and skeletal growth after
distraction osteogenesis have not been clearly elucidated in the literature. In
this case report, a 2-year follow-up of distraction osteogenesis in a 7 year old
boy is documented with lateral and posterior/anterior cephalometric analysis. The
analysis was performed preoperatively and at specific postsurgical periods to
evaluate the facial soft tissue and skeletal growth patterns. Objective analysis
of this growing patient after distraction osteogenesis clearly demonstrates that
the anteroposterior elongation of the mandible is relatively stable, whereas the
vertical lengthening and soft tissue effects are minimal. Critical evaluation of
other patients who have undergone distraction osteogenesis is needed to determine
if this was an isolated incident or the expected result in similar patients.
PMID- 10672213
TI - An inference modeling of human visual judgment of sagittal jaw-base relationships
based on cephalometry: part I.
AB - When there appears to be a contradiction between a cephalometric tracing and what
is seen, the clinician tends to place more reliance on the appearance of the face
in profile than on a formal cephalometric evaluation of the sagittal jaw
relationship. With this in mind, we derived a multiple regression model with
cephalometric variables to explain the visual influences that affect the
subjective classification of sagittal jaw relationships made by experienced
orthodontists. The regression model that showed the highest coefficient of
determination, 0.90, was constructed from a linear combination of the angle ANB,
the anteroposterior position of gnathion, the SN length, and the mandibular body
length. The performance reliability of the inference system has been tested for
175 female adult cases and will be reported in Part II of this article.
PMID- 10672214
TI - Cleft lip and palate management with maxillary expansion and space opening for a
single tooth implant.
AB - An adult Class I malocclusion with a unilateral cleft lip and palate is
presented. The maxillary transverse deficiency was managed with orthopedic
expansion and the missing lateral incisor with space opening, bone grafting, and
single tooth implant. The mild maxillary retrognathia and deficient lip support
was managed with dental compensation.
PMID- 10672215
TI - Reconstruction of an alveolar cleft for orthodontic tooth movement.
AB - Bone grafting to repair an alveolar cleft has long been an integral part of the
treatment of persons with unilateral and bilateral clefts of the lip and
alveolus. The presence of the cleft places a limitation on the orthodontist who
would like to move teeth in the area of the cleft. Various grafting materials
have been placed in alveolar clefts in an attempt to solve this problem. The case
to be presented is a patient with a Class II, Division 2, malocclusion with a
left unilateral alveolar cleft and a repaired cleft lip. Ten months after
initiating orthodontic treatment, a free gingival graft procedure was performed
because of insufficient vestibular depth and the narrow width of the keratinized
attached gingiva at the left maxillary lateral and central incisor region. Two
months after periodontal surgery, a mix of decalcified freeze-dried bone
allograft and a granular bioactive glass graft material (1:1) were applied
subperiostally on the buccal aspect of the edentulous cleft region. Six months
later, the teeth adjacent to the grafted alveolar cleft were orthodontically
moved into the edentulous area. The treatment results indicated that orthodontic,
periodontal, and surgical interventions resulted in a successful closure of the
alveolar cleft as well as improved periodontal conditions of the teeth adjacent
to the cleft area. From the orthodontic point of view, tooth movement can be
achieved successfully into a bone graft made of freeze-dried bone and bioactive
glass.
PMID- 10672216
TI - Effect of light-cure time on the initial shear bond strength of a glass-ionomer
adhesive.
AB - With the introduction of photosensitive (light-cured) restorative materials in
dentistry, various methods were suggested to enhance the polymerization of these
materials including layering and the use of more powerful light-curing devices.
The purpose of this study was to determine the effects of increasing the light
cure time on the initial shear bond strength (in the first half hour) of a resin
modified glass-ionomer adhesive. Eighty-six teeth were divided into 4 groups
according to either; (1) the adhesive system used, namely resin, reinforced glass
ionomer, or composite, and (2) the light-cure time for the glass ionomer
adhesive, namely 40, 45, and 50 seconds. The bonding approach followed the
manufacturer's instructions unless otherwise specified. The results of the
analysis of variance comparing the 4 experimental groups (F = 19.4) indicated the
presence of significant differences between the groups (P =. 0001). In general,
the shear bond strength was greater for the composite adhesive system (?x(-) =
5.2 +/- 2.9 MPa), followed by the 2 groups bonded with the resin-reinforced glass
ionomer adhesive and light cured for 50 seconds (?x(-) = 3.8 +/- 1.1 MPa) and 45
seconds (?x(-) = 3.4 +/- 2.7 MPa). On the other hand, the shear bond strength was
significantly lower for the group bonded with the glass ionomer adhesive and
light cured for 40 seconds only (?x(-) = 0.4 +/- 1.0 MPa). The present findings
indicated the following: (1) the resin-reinforced glass-ionomer adhesive has a
significantly lower shear bond strength in the first half hour after bonding when
compared to a composite resin adhesive; (2) the initial bond strength of the
glass-ionomer adhesive was significantly increased by increasing the light-cure
time for an additional 5 to 10 seconds; (3) the mean increase in the shear bond
strength between 5 and 10 seconds of additional light curing was not significant
but the variability was less with the longer cure time.
PMID- 10672217
TI - Interarch tooth size relationships of 3 populations: "does Bolton's analysis
apply?".
AB - This study evaluates whether Bolton's interarch ratios extend across populations
and genders. The data were derived from systematically collected preorthodontic
casts of 180 patients, including 30 males and 30 females from each of 3
populations (black, Hispanic, and white). Forty-eight mesiodistal contact points
were digitized on each model, and the lengths of the anterior, posterior, and
overall arch segments were calculated. The results showed significant (P <.05)
ethnic group differences in all 6 arch segment lengths and in all 3 interarch
ratios. Whites displayed the lowest overall ratio (92.3%), followed by Hispanics
(93.1%), and blacks (93.4%). The group differences were due primarily to the
relationships between the posterior segments. The arch segments of males were
significantly larger than females; the overall and posterior ratios were also
significantly larger in males than in females. Multiple regression analyses
showed that individual differences in the overall ratio were most closely
associated with the size of the lower second premolar, followed by the upper
lateral incisors, upper second premolars, and the lower central incisors. In
combination, these 4 teeth explained approximately 50% of the variation in the
overall ratio between subjects. We conclude that interarch tooth size
relationships are population and gender specific. Bolton ratios apply to white
females only; the ratios should not be indiscriminately applied to white males,
blacks, or Hispanics.
PMID- 10672218
TI - Human tooth movement in response to continuous stress of low magnitude.
AB - Conventional orthodontic therapy often uses force magnitudes in excess of 100 g
to retract canine teeth. Typically, this results in a lag phase of approximately
21 days before tooth movement occurs. The current project was undertaken to
demonstrate that by using lower force magnitudes, tooth translation can start
without a lag phase and can occur at velocities that are clinically significant.
Seven subjects participated in the 84-day study. A continuous retraction force
averaging 18 g was applied to 1 of the maxillary canines, whereas a continuous
retraction force averaging 60 g was applied to the other. The magnitude was
adjusted for each canine to produce equivalent compressive stresses between
subjects. Estimated average compressive stress on the distal aspect of the canine
teeth was 4 kPa or 13 kPa. The moment-to-force ratios were between 9 and 13 mm.
Tooth movement in 3 linear and 3 rotational dimensions was measured with a 3-axis
measuring microscope and a series of dental casts made at 1- to 14-day intervals.
The results showed a statistical difference in the velocity of distal movement of
the canines produced by the 2 stresses (P =.02). The lag phase was eliminated and
average velocities were 0.87 and 1.27 mm/month for 18 and 60 g of average
retraction force. Interindividual velocities varied as much as 3 to 1 for
equivalent stress conditions. It was concluded that effective tooth movement can
be produced with lower forces and that because loading conditions were
controlled, cell biology must account for the variability in tooth velocities
measured in these subjects.
PMID- 10672220
TI - AAO foundation: A celebration of success: preliminary program of the 100th annual
session, april 28 - may 3, 2000
PMID- 10672221
TI - George S. Uchiyama, DDS, MS, 1922 to 1999
PMID- 10672219
TI - The effect of tooth size discrepancy on occlusion: An experimental study.
AB - The purposes of this experimental study are the following: (1) to compare the
anterior and overall tooth size ratios reported by Bolton to values reported in
epidemiologic studies, (2) to assess the accuracy of tooth size discrepancy
measurements, (3) to investigate to what extent generalized tooth size
discrepancy affects occlusion, (4) to investigate the effect of leveling the
curve of Spee, and (5) to evaluate the effect of extraction therapy of 4
premolars on occlusion. For the first part of the study, Bolton's mean anterior
and overall tooth size ratio (as well as the extraction values) were compared
with calculations derived from 4 publications reporting mean mesiodistal tooth
width by using the t test (P =.05). The second part of the study was carried
out on a setup made from 1 dental cast of a male patient judged to have an ideal
occlusion at the end of a nonextraction treatment. Our data reveal (1) no
significant difference between the overall tooth size ratios of the Bolton values
compared to 4 studies, but the anterior ratios were significantly different, (2)
high reproducibility (99%) of tooth size discrepancy measurements, (3) that
severe tooth size discrepancy affects the occlusion only a little, (4) that an
excessive (6 mm) curve of Spee creates the poorest setup result, and (5) that
extraction therapy only slightly affected the final occlusion. The effect of
generalized tooth size discrepancy appears to be limited.
PMID- 10672222
TI - Robert murray ricketts, DDS, MS
PMID- 10672223
TI - Clinical implications of digital orthodontics.
PMID- 10672224
TI - Litigation, legislation, and ethics. Admissability of board certification.
PMID- 10672225
TI - Glutamate excitotoxicity and neuronal energy metabolism.
AB - The bioenergetic properties of the in situ mitochondria play a central role in
controlling the susceptibility of neurons to acute or chronic neurodegenerative
stress. The mitochondrial membrane potential, delta psi m is the parameter that
controls three interrelated mitochondrial functions of great relevance to
neuronal survival: namely, ATP synthesis, Ca2+ accumulation, and superoxide
generation. The in vitro model we study is the rat cerebellar granule cell in
primary culture and its susceptibility to NMDA receptor-mediated necrosis, which
is preceded by a delayed failure of cytoplasmic Ca2+ homeostasis ("delayed Ca2+
deregulation," DCD). DCD is not caused by a failure of mitochondrial ATP
synthesis since it also occurs in cells maintained purely by glycolysis. The in
situ mitochondria maintain a delta psi m sufficient for ATP synthesis throughout
the exposure of the cells to glutamate until DCD occurs. Even at that stage it
appears that mitochondrial depolarization may be an effect of DCD rather than a
primary cause. This somewhat unorthodox view resolves a number of apparent
paradoxes, such as observations of enhanced superoxide generation by in situ
mitochondria during excitotoxic exposure, since isolated mitochondria generate
superoxide only under conditions of high delta psi m. Mitochondrial
depolarization by selective inhibitors that do not deplete cellular ATP is
acutely neuroprotective.
PMID- 10672226
TI - Fundamental aspects of reactive oxygen species, or what's the matter with oxygen?
AB - A byproduct of normal aerobic metabolism is the generation of dangerously
reactive intermediates of the reduction of O2. These include O2-, H2O2, and HO.
and arise because of the predisposition of O2 for univalent reductions. These
reactive oxygen species (ROS), and others that they can engender, threaten all
cellular macromolecules, and defenses are needed. Among those known to date are:
superoxide dismutases to convert O2- into O2 + H2O2; catalases to dismute H2O2
into O2 + H2O; and peroxidases to reduce H2O2 into 2H2O) and to reduce ROOH into
ROH and H2O. These defenses are aided by enzymes that repair or recycle
oxidatively damaged nucleic acids and proteins. A role for such oxidative damage
in aging and neurodegenerative diseases is well supported.
PMID- 10672227
TI - Ca(2+)-mediated mitochondrial dysfunction and the protective effects of Bcl-2.
AB - Mitochondrial Ca2+ sequestration likely contributes to cell death in
excitotoxicity and ischemia reperfusion injury, and may also be involved in
chronic forms of neurodegeneration in which a compromise in bioenergetic function
alters cellular Ca2+ homeostasis. Bcl-2 overexpression is known to protect
against Ca(2+)-mediated death; the mechanism of protection remains unresolved.
Our data of the ability of Bcl-2 to potentiate mitochondrial Ca2+ uptake capacity
and resistance to Ca(2+)-induced damage is discussed in light of current
information on apoptotic signaling pathways.
PMID- 10672228
TI - Mitochondrial membrane potential and the permeability transition in
excitotoxicity.
AB - Acute neuronal injury caused by activation of glutamate receptors in neurons, or
excitotoxicity, can be triggered by the activation of N-methyl-D-aspartate
receptors and the entry of large amounts of Ca2+. Recent studies have suggested
that mitochondria have a critical role in the excitotoxicity injury mechanism.
Mitochondria accumulate large amounts of Ca2+ following glutamate stimulation,
and also generate reactive oxygen species. Moreover, the prevention of
mitochondrial Ca2+ accumulation protects neurons from injury. The target for the
actions of Ca2+ in the mitochondrial matrix has not yet been established. The
permeability transition pore has the characteristics of a mechanism that is well
suited to mediate neuronal injury. However, evidence for activation of the
permeability transition pore in intact neurons is rather indirect, and these data
suffer from some ambiguities that make it difficult to conclude that permeability
transition is a critical contributor to mitochondrially mediated neuronal injury.
PMID- 10672229
TI - Oxidative phosphorylation disease diagnosis.
AB - Although the mtDNA encodes only 13 polypeptide subunits of the OXPHOS enzymes,
approximately 1,000 proteins are estimated to be necessary for proper OXPHOS
function. Over the past 10 years a wide variety of adult and pediatric OXPHOS
diseases were found to be caused by or associated with mitochondrial DNA (mtDNA)
mutations and nuclear DNA mutations. These advances enhanced the ability to
definitively diagnose patients, develop management plans, and provide genetic
counseling. Recently described nuclear DNA and mtDNA mutations are enhancing our
understanding of this complex group of diseases. The impact of these advances on
our understanding of OXPHOS disease pathogenesis will be reviewed.
PMID- 10672230
TI - The alpha-ketoglutarate dehydrogenase complex.
AB - The alpha-ketoglutarate dehydrogenase complex (KGDHC) is an important
mitochondrial constituent, and deficiency of KGDHC is associated with a number of
neurological disorders. KGDHC is composed of three proteins, each encoded on a
different and well-characterized gene. The sequences of the human proteins are
known. The organization of the proteins into a large, ordered multienzyme complex
(a "metabolon") has been well studied in prokaryotic and eukaryotic species.
KGDHC catalyzes a critical step in the Krebs tricarboxylic acid cycle, which is
also a step in the metabolism of the potentially excitotoxic neurotransmitter
glutamate. A number of metabolites modify the activity of KGDHC, including
inactivation by 4-hydroxynonenal and other reactive oxygen species (ROS). In
human brain, the activity of KGDHC is lower than that of any other enzyme of
energy metabolism, including phosphofructokinase, aconitase, and the electron
transport complexes. Deficiencies of KGDHC are likely to impair brain energy
metabolism and therefore brain function, and lead to manifestations of brain
disease. In general, the clinical manifestations of KGDHC deficiency relate to
the severity of the deficiency. Several such disorders have been recognized:
infantile lactic acidosis, psychomotor retardation in childhood, intermittent
neuropsychiatric disease with ataxia and other motor manifestations, Friedreich's
and other spinocerebellar ataxias, Parkinson's disease, and Alzheimer's disease
(AD). A KGDHC gene has been associated with the first two and last two of these
disorders. KGDHC is not uniformly distributed in human brain, and the neurons
that appear selectively vulnerable in human temporal cortex in AD are enriched in
KGDHC. We hypothesize that variations in KGDHC that are not deleterious during
reproductive life become deleterious with aging, perhaps by predisposing this
mitochondrial metabolon to oxidative damage.
PMID- 10672231
TI - Oxidative stress and a key metabolic enzyme in Alzheimer brains, cultured cells,
and an animal model of chronic oxidative deficits.
AB - Oxidative stress and diminished metabolism occur in several neurodegenerative
disorders. Brains from Alzheimer's disease (AD) patients exhibit several
indicators of oxidative stress and have reduced activities of the alpha
ketoglutarate dehydrogenase complex (KGDHC), a key mitochondrial enzyme. Whether
these abnormalities are secondary to neurodegenerative processes or are inherent
properties of the cells cannot be determined in autopsy brain. Studies in
cultured fibroblasts suggest that AD-related differences in oxidative stress and
KGDHC reflect inherent properties of AD cells. KGDHC is sensitive to oxidative
stress whether the enzyme is studied in cells, in purified mitochondria, or as an
isolated protein. Reductions of brain KGDHC in living rodents lead to oxidative
stress and selective cell death. The results suggest that KGDHC participates in a
deleterious cascade of events related to oxidative stress that are critical in
selective neuronal loss in neurodegenerative diseases.
PMID- 10672232
TI - The use of transgenic and mutant mice to study oxygen free radical metabolism.
AB - To distinguish the role of Mn superoxide dismutase (MnSOD) from that of
cytoplasmic CuZn superoxide dismutase (CuZnSOD), the mouse MnSOD gene (Sod2) was
inactivated by homologous recombination. Sod2 -/- mice on a CD1 (outbred) genetic
background die within the first 10 days of life (mean, 5.4 days) with a complex
phenotype that includes dilated cardiomyopathy, accumulation of lipid in liver
and skeletal muscle, metabolic acidosis and ketosis, and a severe reduction in
succinate dehydrogenase (complex II) and aconitase (a TCA cycle enzyme)
activities in the heart and, to a lesser extent, in other organs. These findings
indicate that MnSOD is required to maintain the integrity of mitochondrial
enzymes susceptible to direct inactivation by superoxide. On the other hand,
Lebovitz et al. reported an independently derived MnSod null mouse (Sod2tmlLeb)
on a mixed C57BL/6 and 129Sv background with a different phenotype. Because a
difference in genetic background is the most likely explanation for the
phenotypic differences, the two mutant lines were crossed into different genetic
backgrounds for further analyses. To study the phenotype of Sod2tmlLeb mice CD1
background, the Sod2tmlLeb mice were crossed to CD1 for two generations before
the -/+ mice were intercrossed to generate -/- mice. The life span distribution
of CD1 < Sod2-/- > Leb was shifted to the left, indicating a shortened life span
on the CD1 background. Furthermore, the CD1 < Sod2-/- > Leb mice develop
metabolic acidosis at an early stage as was observed with CD1 < Sod2-/- > Cje.
When Sod2tmlCje was placed on C57BL/6J (B6) background, the -/- mice were found
to die either during midgestation or within the first 4 days after birth.
However, when the B6 < Sod2 -/+ > Cje were crossed with DBA/2J (D2) for the
generation of B6D2F2 < Sod2-/- > Cje mice, an entirely different phenotype,
similar to that described by Lebovitz et al., was observed. The F2 Sod -/- mice
were able to survive up to 18 days, and the animals that lived for more than 15
days displayed neurological abnormalities including ataxia and seizures. Their
hearts were not as severely affected as were those of the CD1 mice, and
neurological degeneration rather than heart defect appears to be the cause of
death.
PMID- 10672233
TI - The blood-brain barrier and cerebrovascular pathology in Alzheimer's disease.
AB - The pathology of Alzheimer's disease (AD) is not limited to amyloid plaques and
neurofibrillary tangles. Recent evidence suggests that more than 30% of AD cases
exhibit cerebrovascular pathology, which involves the cellular elements that
represent the blood-brain barrier. Certain vascular lesions such as microvascular
degeneration affecting the cerebral endothelium, cerebral amyloid angiopathy and
periventricular white matter lesions are evident in virtually all cases of AD.
Furthermore, clinical studies have demonstrated blood-brain barrier dysfunction
in AD patients who exhibit peripheral vascular abnormalities such as
hypertension, cardiovascular disease and diabetes. Whether these vascular lesions
along with perivascular denervation are coincidental or causal in the
pathogenetic processes of AD remains to be defined. In this chapter, I review
biochemical and morphological evidence in context with the variable but distinct
cerebrovascular pathology described in AD. I also consider genetic influences
such as apolipoprotein E in relation to cerebrovascular lesions that may shed
light on the pathophysiology of the cerebral vasculature. The compelling vascular
pathology associated with AD suggests that transient and focal breach of the
blood-brain barrier occurs in late onset AD and may involve an interaction of
several factors, which include perivascular mediators as well as peripheral
circulation derived factors that perturb the endothelium. These vascular
abnormalities are likely to worsen cognitive disability in AD.
PMID- 10672234
TI - Neurological changes induced by stress in streptozotocin diabetic rats.
AB - Previous studies from our laboratory demonstrated that chronic stress produces
molecular, morphological, and ultrastructural changes in the rat hippocampus that
are accompanied by cognitive deficits. Glucocorticoid impairment of glucose
utilization is proposed as a causative factor involved in stress-induced changes.
Current studies have examined the neurological changes induced by stress in rats
with a preexisting strain upon their homeostatic load--namely, in streptozotocin
(stz)-diabetic rats. Administration of stz (70 mg/kg, i.v.) produced diabetic
symptoms such as weight loss, polyuria, polydipsia, hyperglycemia, and
neuroendocrine dysfunction. Morphological analysis of hippocampal neurons
revealed that diabetes alone produced dendritic atrophy of CA3 pyramidal neurons,
an effect potentiated by 7 days of restraint stress. Analysis of genes critical
to neuronal homeostasis revealed that glucose transporter 3 (GLUT3) mRNA and
protein levels were specifically increased in the hippocampus of diabetic rats,
while stress had no effect upon GLUT3 expression. Insulin-like growth factor
(IGF) receptor expression was also increased in the hippocampus of diabetic rats
subjected to stress. In spite of the activation of these adaptive mechanisms,
diabetic rats subjected to stress also had signs of neuronal damage and oxidative
damage. Collectively, these results suggest that the hippocampus of diabetic rats
is extremely susceptible to additional stressful events, which in turn can lead
to irreversible hippocampal damage.
PMID- 10672235
TI - Functional brain imaging in the resting state and during activation in
Alzheimer's disease. Implications for disease mechanisms involving oxidative
phosphorylation.
AB - In vivo brain imaging of patients with Alzheimer's disease (AD) using positron
emission tomography (PET) demonstrates progressive reductions in resting-state
brain glucose metabolism and blood flow in relation to dementia severity, more so
in association than primary cortical regions. During cognitive or psychophysical
stimulation, blood flow and metabolism in the affected regions can increase to
the same extent in mildly demented AD patients as in age-matched controls,
suggesting that energy delivery is not rate limiting. Activation declines with
dementia severity, and is markedly reduced in severely demented patients. These
results suggest that there is an initial "normal" functionally-responsive stage
in AD, followed by a late less responsive stage. Studies of biopsied and
postmortem brain indicate that the initial stage is accompanied by selective and
potentially reversible down-regulation of the brain enzymes, including cytochrome
oxidase, which mediate mitochondrial oxidative-phosphorylation.
PMID- 10672236
TI - Cellular and molecular mechanisms underlying perturbed energy metabolism and
neuronal degeneration in Alzheimer's and Parkinson's diseases.
AB - Synaptic degeneration and death of nerve cells are defining features of
Alzheimer's disease (AD) and Parkinson's disease (PD), the two most prevalent age
related neurodegenerative disorders. In AD, neurons in the hippocampus and basal
forebrain (brain regions that subserve learning and memory functions) are
selectively vulnerable. In PD dopamine-producing neurons in the substantia nigra
striatum (brain regions that control body movements) selectively degenerate.
Studies of postmortem brain tissue from AD and PD patients have provided evidence
for increased levels of oxidative stress, mitochondrial dysfunction and impaired
glucose uptake in vulnerable neuronal populations. Studies of animal and cell
culture models of AD and PD suggest that increased levels of oxidative stress
(membrane lipid peroxidation, in particular) may disrupt neuronal energy
metabolism and ion homeostasis, by impairing the function of membrane ion-motive
ATPases and glucose and glutamate transporters. Such oxidative and metabolic
compromise may there-by render neurons vulnerable to excitotoxicity and
apoptosis. Studies of the pathogenic mechanisms of AD-linked mutations in amyloid
precursor protein (APP) and presenilins strongly support central roles for
perturbed cellular calcium homeostasis and aberrant proteolytic processing of APP
as pivotal events that lead to metabolic compromise in neurons. Specific
molecular "players" in the neurodegenerative processes in AD and PD are being
identified and include Par-4 and caspases (bad guys) and neurotrophic factors and
stress proteins (good guys). Interestingly, while studies continue to elucidate
cellular and molecular events occurring in the brain in AD and PD, recent data
suggest that both AD and PD can manifest systemic alterations in energy
metabolism (e.g., increased insulin resistance and dysregulation of glucose
metabolism). Emerging evidence that dietary restriction can forestall the
development of AD and PD is consistent with a major "metabolic" component to
these disorders, and provides optimism that these devastating brain disorders of
aging may be largely preventable.
PMID- 10672237
TI - Use of cytoplasmic hybrid cell lines for elucidating the role of mitochondrial
dysfunction in Alzheimer's disease and Parkinson's disease.
AB - There is substantial evidence of mitochondrial defects in neurodegenerative
disorders such as Alzheimer's and Parkinson's diseases (AD and PD). We have
probed the molecular implications of mitochondrial dysfunction in these diseases
by transferring mitochondria from platelets obtained from disease and control
donors into mitochondrial DNA-depleted recipient neuron-based cells (rho 0
cells). This process creates cytoplasmic hybrid (cybrid) cells where the
mitochondrial DNA (mtDNA) from the donor is expressed in the nuclear and cellular
background of the host rho 0 cell. Differences in phenotype between disease and
control groups can thus be attributed to the exogenous mitochondria and mtDNA.
Key methodological issues relating to this approach were addressed by
demonstrating that recipient rho 0 cells have < 1 mtDNA copy/cell, and that
exclusive repopulation with donor mtDNA occurs in cybrid cells. Further, we
describe that sampling of heterogeneous cell populations is a valid approach for
cybrid analysis. Our studies show that the focal respiratory chain defects
reported in platelets of AD and PD cybrids can be recapitulated in AD and PD
cybrids. In addition, both AD and PD cybrids display increased oxidative stress
and perturbations in calcium homeostasis. These data suggest that the transfer of
a mtDNA defect from disease donor platelets is the likely cause of the cybrid
biochemical phenotype, and highlight the potential value of these cell lines as
cellular disease models.
PMID- 10672238
TI - Polyglutamine domain proteins with expanded repeats bind neurofilament, altering
the neurofilament network.
AB - Proteins with expanded polyglutamine (polyQ) repeats cause eight inherited
neurodegenerative diseases. Nuclear and cytoplasmic polyQ protein is a common
feature of these diseases, but its role in cell death remains debatable. Since
the neuronal intermediate filament network is composed of neurofilament (NF) and
NF abnormalities occur in neurodegenerative diseases, we examined whether
pathologic-length polyQ domain proteins interact with NF. We expressed polyQ
green fluorescent fusion proteins (GFP) in a neuroblast cell line, TR1.
Pathologic-length polyQ-GFP fusion proteins form large cytoplasmic aggregates
surrounded by neurofilament. Immunoisolation of pathologic-length polyQ proteins
co-isolated 68 kD NF protein demonstrating molecular interaction. These
observations suggest that polyQ interaction with NF is important in the
pathogenesis of the polyglutamine repeat diseases.
PMID- 10672239
TI - Bioenergetics in Huntington's disease.
AB - Huntington's disease (HD) is an autosomal dominant inherited neurodegenerative
disorder with relentless course and prototypical clinical symptoms. In 1993 HD
was associated with an expanded CAG triplet repeat stretch on chromosome 4 in the
coding region of its target protein, huntington. The length of the resulting
polyglutamine++ extensions correlates with lower age of onset and a higher
density of ubiquitin-positive neuronal intranuclear inclusions. Recently it has
been proposed that mutant huntington induces progressive neuronal cell death by
an apoptotic mechanism. There is strong evidence that disturbances in cellular
energy homeostasis and oxidative damage contribute to neurodegeneration. This
review will summarize and discuss the current concepts that point towards an
involvement of free radical-induced oxidative stress, glutamate excitotoxicity
and mitochondrial respiratory chain defects in pathogenesis of HD.
PMID- 10672240
TI - An integrated strategy for evaluation of metabolic and oxidative defects in
neurodegenerative illness using magnetic resonance techniques.
AB - The number of physiologic and metabolic phenomena amenable to analysis using
magnetic resonance (MR) techniques is increasing every year. MR techniques can
now evaluate tissue parameters relevant to TCA cyclemetabolism, anerobic
glycolysis, ATP levels, blood-brain barrier permeability, macrophage
infiltration, cytotoxic edema, spreading depression, cerebral blood flow and
volume, and neurotransmitter function. The paramagnetic nature of certain
oxidation states of iron leads to the ability to map out brain function using
deoxyhemoglobin as an endogenous contrast agent, and also allows for mapping of
local tissue iron concentrations. In addition to these metabolic parameters, the
number of ways to generate anatomic contrast using MR is also expanding; and in
addition to conventional anatomic scans, mapping of axonal fiber tracts can also
be performed using the anisotropy of water diffusion. A strategy for integration
of these multifarious parameters in a comprehensive neurofunctional exam in
neurodegenerative illness is outlined in this paper. The goals of the integrated
exam, as applied to a given neurodegenerative illness, can be subdivided into
three categories: etiology, natural history, and therapeutic end points. The
consequences of oxidative stress and/or mitochondrial dysfunction are explored in
the context of the various parameters that can be measured using the integrated
MR exam.
PMID- 10672241
TI - Apoptosis and necrosis in cerebrovascular disease.
AB - Neuronal death following ischemic insults has been thought to reflect necrosis.
However, recent evidence from several labs suggests that programmed cell death,
leading to apoptosis, might additionally contribute to this death. We have used
both in vitro and in vivo models to study the role of apoptosis in ischemic cell
death. Some features of apoptosis (TUNEL staining, internucleosomal DNA
fragmentation, sensitivity to cycloheximide) were observed following transient
focal ischemia in rats. Brief transient focal ischemia was followed by delayed
infarction more than 3 days later; this delayed infarction was sensitive to
cycloheximide. A cycloheximide-sensitive component of neuronal cell death was
also observed in cultured murine neocortical neurons deprived of oxygen-glucose
in the presence of glutamate receptor antagonists. This presumed ischemic
apoptosis was attenuated by caspase inhibitors, or by homozygous deletion of the
bax gene. Neurons may undergo both apoptosis and necrosis after ischemic insults,
and thus it may be therapeutically desirable to block both processes.
PMID- 10672242
TI - Effects of ebselen, a glutathione peroxidase mimic, in several models of
mitochondrial dysfunction.
PMID- 10672243
TI - EDTA-induced monovalent fluxes through the Ca2+ uniporter in brain mitochondria.
PMID- 10672244
TI - Signaling events in NMDA receptor-induced apoptosis in cerebrocortical cultures.
PMID- 10672245
TI - In vitro and in vivo protein oxidation induced by Alzheimer's disease amyloid
beta-peptide (1-42).
PMID- 10672246
TI - Depolarization of in situ mitochondria by hydrogen peroxide in nerve terminals.
PMID- 10672247
TI - Monoamine oxidase inhibits mitochondrial respiration.
PMID- 10672248
TI - Enhanced acetate and glucose utilization during graded photic stimulation.
Neuronal-glial interactions in vivo.
PMID- 10672249
TI - Calcium overload triggers rod photoreceptor apoptotic cell death in chemical
induced and inherited retinal degenerations.
PMID- 10672250
TI - Molecular mechanisms of free radical production and protective efficacies of
antioxidants in in vitro ischemia-reperfusion.
PMID- 10672251
TI - A disturbance in the neuronal insulin receptor signal transduction in sporadic
Alzheimer's disease.
AB - Disturbances of glucose and energy metabolism are hypothesized as pathogenetic
factors in sporadic dementia of Alzheimer type (SDAT). Insulin and is receptors
play an important role in the regulation of brain glucose metabolism and neuronal
growth. In postmortem brain cortex in SDAT, the densities of brain insulin
receptors were decreased compared to adult controls, but were increased in
relation to aged controls. Tyrosine kinase activity, a signal transduction
mechanism common to insulin and IGF-1 receptors, was reduced in SDAT in
comparison to middle-aged and age-matched control groups. The data are consistent
with a neurotrophic role of insulin in the human brain and an upregulation of
insulin receptors is SDAT brain as a compensatory mechanism, possibly due to
impaired signal transduction mechanism.
PMID- 10672252
TI - Modulation of presenilin-1 processing by nitric oxide during apoptosis induced by
serum withdrawal and glucose deprivation.
PMID- 10672253
TI - Metabolic and glutamatergic disturbances in the Huntington's disease transgenic
mouse.
PMID- 10672254
TI - Inhibition of the neuronal insulin receptor causes Alzheimer-like disturbances in
oxidative/energy brain metabolism and in behavior in adult rats.
PMID- 10672255
TI - Temporary axonal conduction block and axonal loss in inflammatory neurological
disease. A potential role for nitric oxide?
PMID- 10672256
TI - Maturational changes in rabbit brain phosphocreatine and creatine kinase.
PMID- 10672257
TI - Neurotoxicity and oxidative damage of beta amyloid 1-42 versus beta amyloid 1-40
in the mouse cerebral cortex.
AB - Senile plaques (SP), a neuropathological hallmark of Alzheimer's disease (AD),
are characterized by extracellular accumulations of beta amyloid (A beta). SP
predominantly contain A beta 42 with a small amount of associated A beta 40. We
determined the neurotoxic properties of A beta 42 as compared to A beta 40 by
injections into the frontal cortex of three month old C57BL/6 mice. A beta 42 was
associated with a significantly larger area of glial fibrillary acidic protein
(GFAP) immunoreactivity and a greater density of reactive astrocytes than A beta
40. Immunohistochemical staining for markers of oxidative damage against 3
nitrotyrosine (3-NT) and 8-hydroxydeoxyguanosine (8-OHDG) were significantly more
intense around the A beta 42 injection compared to the A beta 40 injection sites.
These findings are consistent with previous in vitro studies and suggest that A
beta 42 is more neurotoxic and may generate more free radical damage than A beta
40.
PMID- 10672258
TI - Ganglioside GD3, the mitochondrial permeability transition, and apoptosis.
PMID- 10672259
TI - Interactions between melatonin, reactive oxygen species, and nitric oxide.
AB - Accumulation of reactive oxygen species is critical for the neuropathology of
Alzheimer's disease. Melatonin hormone, an antioxidant, could play a key role in
aging and senescence. Nitric oxide, a biologically active unstable radical, is
synthesized by nitric oxide synthase when converting L-arginine to L-citrulline.
We have investigated whether the treatment of cultured cells with melatonin could
possibly reduce the release of free radicals and other ROS. We assayed NO
indirectly by measuring the level of its stable end products, nitrite/nitrate
(NOx), using the Griess reagent. When the neuroblastoma cells such as N1E-115
were treated with a NO donor such as sodium nitroprusside (SNP), a significant
level of NOx was detected in a time- and dose-dependent manner in the conditioned
medium compared to the untreated cells or SNP-containing media. In neuroblastoma
cells, the release of NOx as mediated by SNP was significantly inhibited by
treatment with (i) carboxy-PTIO, a NO scavenger; (ii) SOD-1, superoxide
dismutase; and (iii) melatonin. In these cells SNP-mediated NOx release was
mediated by superoxide ions and/or free radicals that can be inhibited by
melatonin. The ROS-scavenging function of melatonin along with its
neuroprotective and neurodifferentiating role can be utilized for the prevention
of neurodegenerative disorders such as AD.
PMID- 10672260
TI - Effect of oxidative stress on DNA damage and beta-amyloid precursor proteins in
lymphoblastoid cell lines from a Nigerian population.
AB - The epsilon 4 allele of apolipoprotein E (APOE) is strongly associated with late
onset Alzheimer's disease (AD) in Caucasian populations, but our studies suggest
that APOE epsilon 4 is not a risk factor for AD in Nigerian blacks and is a weak
risk factor in African-Americans. The prevalence of AD is lower in Nigerians than
in African-Americans. Increased oxidative damage to macromolecules in brain
tissue by reactive oxygen species (ROS) has been reported in AD. Here we examined
the effects of endogenous and induced oxidative stress on total (nuclear and
mitochondrial) DNA damage in lymphoblastoid cell lines (5 probable AD and 3
controls) from Ibadan, Nigeria. Cells were exposed to 200 microM t-butyl peroxide
(a generator of ROS) for 4 hours. Total DNA was isolated and digested with
nuclease P1 and alkaline phosphatase. DNA fragments were separated by HPLC and
the levels of 8-hydroxy-2'-deoxyguanosine (OH8dG, an indicator of DNA damage) and
deoxyguanosine (dG) determined. We did not detect a significant difference in the
OH8dG/dG ratio in untreated or treated cell lines in the two groups, and this was
independent of APOE genotype. We also examined, by Western blotting, the level of
beta-amyloid precursor protein (APP) which is involved in AD. The level of the
heat shock protein (HSP-70) was examined as a control. There was a slight
decrease in levels of APP and HSP-70 following treatment. Studies in cell lines
from Caucasian subjects have shown an increase in mitochondrial DNA damage
following oxidative challenge. Our preliminary results suggest that African
populations are less vulnerable to chemical-induced oxidative DNA damage.
PMID- 10672261
TI - Evidence for energy failure following irreversible traumatic brain injury.
PMID- 10672262
TI - Regulation of mitochondrial gene expression in differentiated PC12 cells.
PMID- 10672263
TI - Does dopamine contribute to striatal damage caused by impaired mitochondrial
function?
PMID- 10672264
TI - Discordance between traditional pathologic and energy metabolic changes in very
early Alzheimer's disease. Pathophysiological implications.
AB - These results suggest that neither the loss of entorhinal efferents nor
cholinergic deficit explains all the metabolic features seen in very early AD.
Given recent immunohistological evidence of massive glutamatergic synaptic
alteration in early AD cortex and insights into neuronal and glial mechanisms of
glucose metabolism, very early metabolic changes in AD probably reflect a
significant impairment of glycolytic activities in the cortico-cortical
glutamatergic systems in a preclinical stage of the disease. However, the exact
mechanisms of such impairment in these neurons are yet to be determined.
PMID- 10672265
TI - Low frequencies of mitochondrial DNA mutations cause cardiac disease in the
mouse.
PMID- 10672266
TI - Effects of the solvent 1,2,4-trimethylcyclohexane on respiratory burst in human
neutrophil granulocytes. A chemiluminescence and electron paramagnetic resonance
spectrometry study.
PMID- 10672267
TI - Neuronal RNA oxidation in Alzheimer's disease and Down's syndrome.
PMID- 10672268
TI - Ca(2+)-dependent permeability transition and complex I activity in lymphoblast
mitochondria from normal individuals and patients with Huntington's or
Alzheimer's disease.
PMID- 10672269
TI - Mitochondrial porin, a novel target to prevent ischemia-induced
neurodegeneration?
PMID- 10672270
TI - Bcl-2 and p53: role in dopamine-induced apoptosis and differentiation.
AB - The fate of a neuron in the developing brain to multiply, differentiate, or die
in an apoptotic manner depends on the expression of genes that are involved in
regulating the cell cycle. Recent studies determined the involvement of several
genes, including cyclin A and B2, in dopamine-induced apoptosis in cultured chick
sympathetic neurons. Another gene that plays a role in apoptosis and
differentiation of neurons, oligodendrocytes and PC12 cells is p53. It is also
known that DNA damage increases p53 levels, triggering repair or apoptosis in
response to moderate or severe damage, respectively. NMB cells express active and
inducible forms of p53, thus being particularly suitable to analyze the role of
this gene in dopamine-induced apoptosis and differentiation. The main observation
of this work is that low concentrations of dopamine induce differentiation while
high concentrations induce apoptosis, and that concentrations of dopamine that
induce apoptosis increased p53 levels. There peak increase in p53 was within 3-6
h, before cell death. Thus, treatment with a high dopamine concentration may
result in oxidation products and/or free radicals that heavily damage DNA, thus
increasing p53 levels and initiating a cascade of events leading to apoptosis.
Lower concentrations of dopamine apparently have a milder damaging effect on the
DNA and induce growth arrest and differentiation. In various systems Bcl-2
inhibits cell death, being apoptotic or necrotic. Bcl-2, and other members of the
family, such as Bax, are located downstream to p53 in the apoptotic pathway, and
they contain negative or positive p53 response elements. Bcl-2 also protects
cells by acting as antioxidant. Neuronal differentiation may be accompanied with
an increase in Bcl-2, though it was suggested that the role of Bcl-2 in
differentiation is less critical than in apoptosis. Herein, Bcl-2 was found to
inhibit dopamine neurotoxicity. Whether the expression of Bcl-2 is regulated by
different dopamine concentrations, or by dibutyryl-cAMP and DMSO, remains to be
determined.
PMID- 10672271
TI - Mitochondria mediate nitric oxide-induced cell death.
PMID- 10672273
TI - Measurement of oxidative DNA damage in the human p53 and PGK1 gene at nucleotide
resolution.
PMID- 10672272
TI - Induction of apoptosis and necrosis in human neuroblastoma cells by cholesterol
oxides.
PMID- 10672274
TI - The glucose paradox in cerebral ischemia. New insights.
AB - The present in vivo findings that lactate, accumulated during an ischemic
episode, is an essential aerobic energy substrate during the initial postischemic
period are in full agreement with out in vitro findings. Moreover, the beneficial
effects of hyperglycemia are also in agreement with our and others' in vitro
results that have demonstrated a neuroprotective effect of glucose against
hypoxic change. The aggravation of ischemic delayed neuronal damage by glucose
loading 15 min prior to the ischemic insult is likely the result of glucose
induction of a short-acting (30 to 60 min) systemic factor (hormonal?) that, when
combined with an ischemic insult, potentiates the ischemic damage.
PMID- 10672275
TI - Interactions of chloromethyltetramethylrosamine (Mitotracker Orange) with
isolated mitochondria and intact cells.
PMID- 10672276
TI - Attenuation of neuronal death by NMDA and oxygen-glucose deprivation in cortical
neurons maintained in high glucose.
PMID- 10672277
TI - Astrocyte nitric oxide causes neuronal mitochondrial damage, but antioxidant
release limits neuronal cell death.
PMID- 10672278
TI - Mechanisms of selective neuronal cell death due to thiamine deficiency.
AB - Multiple mechanisms contribute to the selective brain lesions observed in WKS and
experimental thiamine deficiency. Recent evidence of early microglial activation
and increased free radical production suggest that oxidative stress processes
play an important early role in the brain damage associated with thiamine
deficiency.
PMID- 10672279
TI - Inhibition of alpha-ketoglutarate dehydrogenase due to H2O2-induced oxidative
stress in nerve terminals.
PMID- 10672280
TI - ATPases of synaptic plasma membranes and vesicles from rat cerebral cortex during
aging and hypoxia.
PMID- 10672281
TI - Mitochondrial compartmentation at the cellular level: astrocytes and neurons.
PMID- 10672282
TI - Detection of respiratory chain defects in cultivated skin fibroblasts and
skeletal muscle of patients with Parkinson's disease.
PMID- 10672283
TI - Prevention of neurodegeneration by a neuroprotective radical scavenger.
PMID- 10672284
TI - Mitochondria, neurodegenerative diseases, and selective neuronal vulnerability.
PMID- 10672285
TI - Regional differences in mortality: a comparison between Austria, Hungary and
Switzerland.
AB - BACKGROUND: Important differences in mortality rates exist even between
neighbouring countries. This should facilitate the identification of the
lifestyle parameters underlying these differences. The mortality rates obtained
in Hungary, Austria and Switzerland were compared. METHODS: The mortality rates
for all-cause, total cardiovascular, total cancer and stroke mortality were
obtained from a special tape from WHO. Nutritional data were obtained from FAO
food balance sheets and from dietary surveys. Gompertz and polynomial equations
were calculated from the age-specific mortality rates. FINDINGS: Great
differences in mortality exist between the three countries. In the period from
1950 until 1995 mortality decreased in Austria and Switzerland, but increased in
Hungary. In men, total cancer and total cardiovascular mortality also increased
markedly in Hungary during the last 20 years. Hungary has a lower dietary P/S
ratio, a higher level of animal/vegetal fat and a lower consumption of fruit than
Austria and Switzerland, combined with a high level of salt consumption. The
level of cigarette smoking is similar in Hungary and Switzerland. The increase in
mortality rate in Hungary is less pronounced in women than in men.
INTERPRETATION: The major differences in lifestyle between the three countries
concern socio-economic and nutritional patterns. Epidemiological evidence favours
nutrition as the most important determinant of the differences in mortality rates
between the three countries.
PMID- 10672286
TI - The effects of halothane and sevoflurane on QT dispersion.
AB - QT dispersion is defined as the difference between QT (max) and QT (min) in the
12-lead surface ECG. It has been shown to reflect regional variations in
ventricular repolarization and is significantly greater in patients with
arrhythmic events than in those without them. The aim of this study was to
examine the effects of halothane and sevoflurane on QT and QTc dispersion during
inhalational induction of anaesthesia. The effects on QT and QTc dispersion of
halothane and sevoflurane have been investigated during induction of anaesthesia.
Forty-six ASA (American Society of Anaesthesiologists) physical status I-II
patients, aged 16-50 years, undergoing general anaesthesia were randomly
allocated to receive either halothane or sevoflurane. The mean baseline values
for QT and QTc dispersion were not significantly different between the two groups
(P > 0.05). QT dispersion was increased with halothane compared with baseline
values (50 +/- 16 ms vs. 29 +/- 9 ms, P < 0.01) and after sevoflurane compared
with baseline (48 +/- 15 vs. 33 +/- 8 ms, P < 0.01). Also, QTc dispersion was
increased with halothane compared with baseline values (48 +/- 13 ms vs. 31 +/- 9
ms, P < 0.001) and after sevoflurane compared with baseline (50 +/- 14 vs. 40 +/-
11 ms, P < 0.01). The QTc interval did not change by both sevoflurane (443 +/- 7
vs. 431 +/- 21 ms, P > 0.05) and halothane (419 +/- 33 vs. 431 +/- 19 ms, P >
0.05) compared with baseline. Both halothane and sevoflurane cause myocardial
repolarisation abnormalities in man in terms of increased QTc dispersion. This
may be relevant in the aetiology of arrhythmias in patients during anaesthesia
with halothane or sevoflurane.
PMID- 10672287
TI - Structural heart adaptations in triathletes.
AB - OBJECTIVE: To perform a triathlon in aerobic conditions, a variety of
cardiovascular, haemodynamic and metabolic adaptations are required. The heart is
the central concern and also the most important limiting factor. In this study we
investigate the structural and functional heart adaptations of a group of
triathletes. METHODS AND RESULTS: A group of 52 male triathletes was divided into
4 subgroups in function of their athletic results and compared with a control
group of 22 healthy, very active but no athletic men. The groups had comparable
anthropometric and general physical characteristics. Very significant differences
in cardiac structure and cardiac function were observed between the groups. In
the triathletes, we registered distinct signs of significantly mixed eccentric
and concentric hypertrophy. Unlike the findings in a pathological left
ventricular hypertrophy, the diastolic left ventricular function in triathletes
was completely normal and even better than in the control group. The late passive
diastolic filling period of the triathlete, in particular, seemed to have
specific characteristics. The comparison between the subgroups of triathletes
shows us that genetic factors probably play an important role in the cardiac
adaptations in triathletes. CONCLUSIONS: In our opinion the "athletic heart" in
triathletes is not a specific "physiological entity" but is a transitional phase
to a dilated hypertrophic cardiomyopathy. Our study yields some arguments for the
following proposition: "People are born as elite athletes, with specific
characteristics of the left ventricle and with a specifically supernormal
diastolic left ventricular function."
PMID- 10672288
TI - Secular trends in cardiovascular mortality in Iran, with special reference to
Isfahan.
AB - OBJECTIVE: There has been a general decline in mortality from cardiovascular
diseases (CVDs) in most of the developed countries since the beginning of the
1970s. Still, in recent years developing countries have seen an increasing
frequency in CVD mortality. However, mortality rate studies in these populations
are scarce. Here we report all-cause and CVD mortality rates for men and women
aged 25-74 years over a 16-year period in 24 cities in Iran with special
reference to the city of Isfahan. METHODS AND RESULTS: The study was based on
national death records using the ninth international classification of diseases
and age standardization was performed using the total population of Iran in 1985
as a standard. Due to limitations in available data, mortality rates for the
specific categories of CVD for the whole country could not be provided. The in
hospital death rates following myocardial infarction in coronary care units
(CCUs) and cardiology departments in Isfahan hospitals were also assessed. The
completed medical records from hospitals or the relatives of decedents were
reviewed by physicians certified in internal medicine, cardiology and neurology
to assess the reliability of death certificate data regarding CVD by determining
the sensitivity and specificity of the death certificates against the standard of
the reviewers. The official circulatory diseases proportional mortality ratio
continues to rise since 1981 with a steep increase since 1987, constituting 26.6%
and 47.3% of all deaths in 1981 and 1995, respectively. Age-adjusted all-cause
and CVD mortality data were decreasing since 1981 and increasing since 1990.
During those years age-adjusted CVD, stroke and other CVD mortality rates were
decreasing in Isfahan with a slight increase in ischaemic heart disease (IHD)
death rates in both sexes. Mortality rates based on sex showed a 38% and 24.8%
decline in all-cause and CVD mortality in men between 1981 to 1995, and a 35% and
34.9% decline for female mortality rates for the same period, respectively. The
in-hospital death rate following myocardial infarction in Isfahan was increasing
between 1993 and 1995 with a slight decrease thereafter. The results of death
certification assessment showed a specificity of 0.89 and a sensitivity of 0.43
with the positive and negative predictive values of 0.82 and 0.57, respectively.
CONCLUSION: These data indicate that circulatory diseases remain a serious public
health threat in Iran. It suggests the ongoing need for more regular, systematic
and innovative surveillance data to improve the capability of measuring,
explaining and predicting the disease trend on which the national public health
policy depends.
PMID- 10672289
TI - The effect of aminophylline infusion on the exercise capacity in patients with
syndrome X.
AB - Aminophylline was known to decrease effort angina and ischaemia in patients with
coronary artery disease and stable angina. This effect has been explained by the
antagonization of the vasodilatation caused by adenosine and the prevention of
the transmural myocardial maldistribution (steal phenomenon). In this study,
treadmill exercise tests (with Bruce protocol) were performed in 14 patients (11
women, 3 men, mean age 51 +/- 9.9 years) diagnosed with syndrome X (typical
anginal chest pain, abnormal stress test, normal coronary angiography) before
(basal condition) and after the acute i.v. aminophylline infusion (total dosage 6
mg/kg within 15 minutes). It was shown that aminophylline lengthened the time
before the occurrence of ischaemia in patients with syndrome X by increasing the
ischaemia threshold in spite of the occurrence of tachycardia but it had no
effect on the total exercise duration. Aminophylline infusion also exerted a
beneficial effect on exercise-induced chest pain. It has been suggested that the
role of the adenosine receptor could be important in the pathogenesis of syndrome
X.
PMID- 10672290
TI - Implantation of 500 consecutive cardiac pacemakers in the electrophysiology
laboratory.
AB - OBJECTIVE: The purpose of this study was to examine the practice of cardiac
bradycardia pacing in an electrophysiology laboratory and to evaluate the safety
and efficacy of pacemaker implantation by cardiologists in this setting. METHODS
AND RESULTS: We evaluated a consecutive series of the first 500 permanent
pacemakers (mean age of patients: 74 +/- 14 years) implanted entirely in the
electrophysiology laboratory at our institution. All procedures were performed by
two cardiologists. Three-hundred and four patients (60.8%) received a dual
chamber device. After 3 months of follow-up, procedure-related complications
occurred in 19 patients (3.8%). The most frequent complication was lead
dislodgement (1.4%). There were 2 postoperative infections (0.4%). The mean time
to hospital discharge after the implant was 2.9 +/- 1.6 days. CONCLUSIONS: These
results show that permanent pacemaker implantation may be successfully carried
out by cardiologists in the electrophysiology laboratory with a low complication
rate. Atrial lead dislodgement seems to be the most frequent complication in
centres with a high proportion of dual-chamber pacemaker implantations.
PMID- 10672291
TI - Prediction of peak exercise oxygen uptake by cardiopulmonary measurements at rest
in heart transplant candidates.
AB - OBJECTIVE: Peak oxygen uptake (VO2) is a powerful prognostic index, but maximal
exercise testing in heart transplant candidates has a number of disadvantages. It
is unknown whether it is possible to predict peak VO2 from a comprehensive
dataset with parameters of heart and lung function at rest. METHODS: One hundred
adult patients in sinus rhythm and with either idiopathic or ischaemic heart
failure performed a graded cycle ergometer test until volitional fatigue and
underwent radionuclide ventriculography, heart catheterization, and lung function
measurements at rest. RESULTS: Weight, height, age, gender and aetiology of heart
failure explained 48% of the variance of peak VO2. On top of these
anthropometric, demographic and clinical patient characteristics, 12% of the
variance of peak VO2 was additionally explained by all resting measurements
combined, i.e. radionuclide left ventricular ejection fraction, peak ejection
rate, peak filling rate, cardiac frequency, mean right atrial pressure, pulmonary
capillary wedge pressure, pulmonary artery pressures, cardiac output, forced
vital capacity, forced expiratory volume in one second, and pulmonary diffusing
capacity (cumulative R2 = 0.60); among these, pulmonary vascular resistance was
the most important predictor (+6%; P < 0.001). Analyses in a subset of 43 male
patients pointed out that systemic pressures and vascular resistance were not
related to peak VO2. CONCLUSION: On the basis of resting left ventricular
function, haemodynamics, and routine pulmonary measurements, it is unlikely to
accurately predict exercise tolerance in the majority of heart transplant
candidates, i.e. patients with either idiopathic or ischaemic heart failure and
able to exercise until exhaustion.
PMID- 10672292
TI - Coexistence of a left posteroseptal tract with persistent left superior vena
cava. Ablation through an anomalous superior vena cava.
AB - A case of a young male with WPW syndrome due to a left posteroseptal tract
associated with a persistent left superior vena cava is described. After
unsuccessful ablation attempts with a number of different approaches at
conventional target sites, the accessory connection was successfully ablated
within the coronary sinus. This was achieved only when the ablation catheter was
introduced through the persistent left superior vena cava.
PMID- 10672293
TI - Reversible hypertrophic cardiomyopathy in congenital hyperinsulinism.
AB - A neonate with congenital focal hyperinsulinism developed hypertrophic
cardiomyopathy that progressed until partial pancreatectomy was performed.
Surgery was followed by complete resolution of the condition. Hyperinsulinism may
be a cause of treatable cardiomyopathy.
PMID- 10672294
TI - Transoesophageal echocardiographic diagnosis of a dissected aorticovenous
anastomosis causing cardiac tamponade.
PMID- 10672295
TI - Intra-operative premature rupture of the cerebral aneurysms. Analysis of the
causes and management.
AB - The causes and management of intra-operative premature rupture are analysed and
discussed. During the past 6 years, the authors, performed 398 consecutive direct
surgical interventions for ruptured cerebral aneurysms. Intra-operative premature
rupture is defined as a rupture which occurs before the securing of the parent
arteries or the neck of the aneurysm and is out of control, at least temporarily.
The causes and management were retrospectively analyzed by reviewing video tape
recordings. Intra-operative premature ruptures which met the above definition
occurred in 24 cases (6.0%). The causes were as follows: 1.) dural opening and
arachnoid opening (8.3%), 2.) haematoma removal (12.5%), 3.) brain retraction
(16.7%), 4.) aneurysm dissection (62.5%). A double suction technique was used to
control bleeding and haemostasis with a small piece of cotton or a temporary
clip, performed in 20 cases (83.3%). However, in cases with premature rupture
immediately after the dural or arachnoid opening, the extension of the haematoma
into the subarachnoid space resulted in severe brain swelling and partial
resection of the brain had to be done to secure temporary clipping. The double
suction technique and primary haemostasis using a small piece of cotton or
temporary clip resulted in good outcome even in cases with premature rupture.
However, very early premature rupture also occurred although its incidence was
extremely rare. The removal of part of the brain can secure the working space but
the outcome was poor.
PMID- 10672296
TI - Complications associated with transvenous embolisation of cavernous dural
arteriovenous fistula.
AB - Results are presented of transvenous embolisation, via either the inferior
petrosal sinus (IPS) or the superior ophthalmic vein (SOV), for 19 patients with
cavernous dural arteriovenous fistula with special emphasis on complications. In
17 patients (89%) there was complete angiographic elimination of the shunts and
resolution of the symptoms. The remaining two patients also improved clinically,
regardless of the minimal residual shunts. Complications included forehead
dysaesthesia in one patient, blepharoptosis in two, and transient abducens nerve
palsy in three. Injury of the supra-orbital nerve and levator muscle occurred in
association with the exposure of the SOV in the patient with dysaesthesia of the
forehead and in those with blepharoptosis, respectively. In two patients,
abducens nerve palsy resulted from coil over-packing in the cavernous sinus and
from dissection of the clival dura during guidewire penetration of the thrombosed
IPS in one patient. We found that the complication rate decreased with time,
because we became better with this procedure. We believe that transvenous
embolisation is the best available treatment modality if one pays careful
attention to avoid complications related to the procedure.
PMID- 10672297
TI - Does additional discectomy and the degree of dural sac compression influence the
outcome of decompressive surgery for lumbar spinal stenosis?
AB - The discussion regarding factors that reliably predict the long-term surgical
results in patients with lumbar spinal stenosis is still going on. This
retrospective study analyses the relation between the dimensions of the dural sac
and patients' clinical status before and after decompressive operations performed
with or without additional discectomy. The type of surgery performed in 134
patients and the dural sac dimensions measured on postmyelograpic computed
tomography in 100 of these patients were related to the Prolo scores before
surgery and at follow-up (mean 46 months). The degree of dural sac compression
correlated significantly with the patients' postoperative Prolo score and with
the difference between the pre- and postoperative scores. The dural sac diameters
predicted outcome after surgery more reliably than the preoperative Prolo scores.
There was no statistically significant difference in the outcome when comparing
patients with and without additional discectomy. The results presented suggest
that the relief of symptoms after decompressive surgery for lumbar spinal
stenosis correlates with the degree of the dural sac compression and that the
simultaneous presence of disc herniation necessitating additional discectomy does
not influence the postoperative outcome. However, these results have to be
confirmed by prospective studies.
PMID- 10672298
TI - Radiosurgery of vestibular schwannomas: a minimally invasive alternative to
microsurgery.
AB - From April 1992 till December 1998 stereotactic radiosurgery (Gamma Knife) was
applied to 192 patients with vestibular schwannomas. 56 of them had radiosurgery
as primary treatment modality and were followed-up for at least 4 years (48-80
months, median 62). Without fatal complications, control of tumour growth was
achieved in all but three cases, useful hearing being preserved in more than one
half of the patients (62%). The neurological state improved in 30 patients (54%).
Irradiation-associated adverse effects (18%) comprised neurological signs
(incomplete facial palsy, four cases (two recovered completely), and mild
trigeminal neuropathy, three cases, respectively) and morphological changes
(three patients) marked by an enlargement of pre-existing cystic components
calling for additional surgical treatment: Microsurgical decompression was
performed in two cases, the third patient underwent a shunting procedure because
of hydrocephalus formation. Based on the present data, radiosurgery represents an
effective treatment for vestibular schwannomas associated with an exceptionally
low mortality rate and a good quality of life. With respect to the preservation
of cranial nerve function, results are comparable to microsurgical resection. A
short duration of hospitalization and a quick return to normal activities
constitute further advantages and contribute to cost effectiveness in public
health care.
PMID- 10672299
TI - Prolactin secreting pituitary adenomas: analysis of 429 surgically treated
patients, effect of adjuvant treatment modalities and review of the literature.
AB - OBJECTIVE: We performed this retrospective analysis to determine the efficacy of
surgery and radiotherapy over hormonal and volumetric control of prolactinomas,
many of which had failed during dopa-agonist therapy. In the same analysis, the
efficiency of topical bromocriptine application as a preliminary study was
compared with standard treatment modalities. MATERIALS AND METHODS: Between 1982
1997, 429 prolactinoma patients who underwent surgery at Hacettepe University
Neurosurgery Department and at Bayindir Medical Center were included in this
study. All patients were classified according to Hardy's classification scheme
and were further divided into 'invasive' and 'non-invasive' groups based on this
radiological classification system. The mean follow-up time was 38.4 months. One
hundred and thirty five patients had peroperative bromocriptine application into
the sellar cavity and these, either receiving radiotherapy (RT) or not, were
analysed separately from the other 294 patients. In the early post-operative
period, 104 of these patients were given conventional radiotherapy with median
dose of 4500 cGy. We focused on the effects of surgery and radiotherapy over
volumetric and hormonal tumour control on the basis of invasion characteristics
and the early results of topical bromocriptine application in macroprolactinoma
patients; and compared our results with the literature. RESULTS: Statistical
analysis revealed that radiotherapy was not effective over hormonal and
volumetric tumour control for prolactinomas. We did not observe any correlation
to dural invasion of the sellar floor, recurrence, and the disease-free survival
time. Topical bromocriptine application seemed to improve the volumetric control
in 135 selected macroprolactinoma patients but not hormonal response compared
with the standard treatment modalities. CONCLUSION: Conventional radiotherapy is
not as effective as expected for prolactinomas and should not be preferred
considering its adverse effects. Tumoural infiltration of the sellar dura mater
is not a prognostic criterion for recurrence expectation and, therefore, should
not be a criterion for radiotherapy after surgery. After subtotal removal,
postoperative dopa-agonist therapy should be considered even if the patient was
intolerant or resistant to previous treatment since surgery seems to improve
patients' drug tolerance and cooperation due probably to the lower dose
requirement. The early results of topical bromocriptine application seem to
improve volumetric tumour control but this should not be accepted as a judgement
since we need to wait for later results and to expand the sample size for more
reliable interpretation.
PMID- 10672300
TI - Comparison between monopolar and bipolar electrical stimulation of the motor
cortex.
AB - Intra-operative neurophysiological techniques allow reliable identification of
the sensorimotor region and make their anatomical and functional preservation
feasible. Monopolar cortical stimulation has recently been described as a new
mapping technique. In the present study this method was compared to the
"traditional" technique of bipolar stimulation. Functional mapping of the motor
cortex was performed in 35 patients during surgery in the central region. The
central sulcus (CS) was identified by somatosensory evoked potential (SEP) phase
reversal. Cortical motor mapping was first performed by monopolar anodal
stimulation with a train of 500 Hz (7-10 pulses) followed by bipolar stimulation
(pulses at 60 Hz with max. 4 sec train duration). Surgery was performed under
general anaesthesia without muscle relaxants. Of 280 motor responses elicited by
bipolar cortical stimulation, 54.23% [152] were located in the primary motor
cortex (PMC), 37.85% 106[ outside the motor strip in the secondary motor cortex
(SMC), and 8% 22[ posterior to the CS. Of 175 motor responses elicited by
monopolar cortical stimulation. 68.57% 120[ were located in the SMC, 23.42% 41[
in the SMC and 8% 14[ posterior to the CS. Contrary to the general clinical view,
there is considerable overlapping of primary motor units over a cortical area
much broader than the "classical" narrow motor strip along the CS. Bipolar
cortical stimulation is more sensitive than monopolar for mapping motor function
in the premotor frontal cortex. Both methods are equally sensitive for mapping
the primary motor cortex.
PMID- 10672301
TI - Nosocomial infections in a neurosurgery intensive care unit.
AB - In order to identify overall and site-specific nosocomial infection (NI) rates in
patients receiving neurosurgical intensive care therapy, a prospective study was
started in February 1997 in the eight-bed neurosurgical ICU of the University
Hospital of Freiburg, Germany. Case records were reviewed twice a week, all
microbiology reports were reviewed and ward staff was consulted. NI were defined
according to the CDC-criteria and were categorised into specific infection sites.
Within 20 months, 545 patients with a total of 5,117 patient days were
investigated (mean length of stay: 9.4 days). 113 NI were identified in 90
patients (72 pts. with one, 13 with two and 5 with three infections,
respectively). A moderate to high overall incidence (20.7/100 pts.) and a
moderate incidence density (22.1/1,000 patient days) of NI in the neurosurgical
ICU could be documented; these figures are well within the range of published
data. Site specific incidence rates and incidence densities were: 1 bloodstream
infection per 100 patients (0.9 central line-associated BSIs per 1,000 central
line-days), 9 pneumonias per 100 patients (15.1 ventilator-associated pneumonias
per 1,000 ventilator-days), 7.3 urinary tract infections per 100 patients (8.5
urinary catheter-associated UTIs per 1,000 urinary catheter-days). Additionally,
1.1 cases of meningitis, 0.7 brain abscesses/ventriculitis, and 1.7 other
infections (surgical site infection, bronchitis, catheter related local
infection, diarrhoea) were documented per 100 patients, respectively. 14.6% of
isolated pathogens were E. coli, 10.2% enterococci, 9.6% S. aureus, 6.4% CNS,
6.4% Klebsiella spp., 5% Enterobacter spp. and 5% Pseudomonas spp. In 11 cases of
NI no pathogen could be isolated.
PMID- 10672302
TI - DREZ surgery on conus medullaris (after failed implantation of vascular omental
graft) for treating chronic pain due to spine (gunshot) injuries.
AB - The results of DREZlesioning procedure used for the treatment of chronic
intractable pain due to deafferentation caused by gunshot injuries at the
thoracolumbar (T10-L1) spine level are reported in six patients. The specificity
of these cases arises from the fact that all the patients underwent, after
decompressive laminectomy, an implantation of vascularized omental graft on the
injured cord segments, 4-17 months after injury. Because of the failure of this
method, which did not improve spinal function nor hinder the development of pain,
surgery in the DREZ was performed 2-5 years after implantation. The results of
the microsurgical DREZotomy procedure in those patients, 7-12 months after the
surgery were: 4 patients with complete pain relief and 2 patients with pain
relieved of 80%. All the patients with well-confined segmental pain were
completely cured.
PMID- 10672303
TI - Neurological complications of childhood malignancies.
AB - Between Jan 1982 to Jun 1994, 154 children with malignant non-central nervous
system tumors, excluding leukemias and lymphomas, were admitted and treated at
the UKMC. Fifty-one (33%) of these cases suffered with 64 neurological
complications during the course of their diseases. Nine cases suffered with
multiple neurological complications. Nervous system metastasis was the most
common neurological complication (n = 24; 15.6%), which was followed by nervous
system infection (n = 17; 11%). Twelve (7.7%) cases had treatment related
peripheral or cranial neuropathies. Seven (4.5%) cases had new onset of grand
mall seizures. One case had paraneoplastic syndrome, one case had
panhypopituitarism secondary to whole brain radiation, and one case had Horner's
syndrome secondary to tumor removal. Ten cases suffered with neurological
sequelae secondary to neurological complications. Three of these cases suffered
with developmental delay and mental retardation. Fifty-one patients with
neurological complications were followed for 9 to 102 months. While 30 (19.7%)
patients were alive, 20 (13%) patients died and one case was lost during the
analysis of the results. Neuroblastoma/ganglioneuroblastoma has the highest rate
for causing neurological complication. IN CONCLUSION: neurological complications
were seen on 33% of childhood solid malignant tumors. Nervous system metastasis
had the worst prognosis and the most frequent neurological complication.
Neurological complications did not increase the mortality rate, but one-third of
surviving patients with neurological complications suffered with neurological
sequelae.
PMID- 10672304
TI - Reversal of cerebral vasospasm by the nitric oxide donor SNAP in an experimental
model of subarachnoid haemorrhage.
AB - The constant release of nitric oxide (NO) is essential to maintain basal
cerebrovascular tone. Oxyhaemoglobin, liberated by lysis of red blood cells after
subarachnoid haemorrhage binds NO and prevents its entry into vascular smooth
muscle cells. While endothelium-dependent vasoconstriction is preserved,
decreased levels of NO inhibit endothelium-dependent relaxation and may cause
vasospasm. S-nitrosothiols are potent vasodilators and precursors of NO. The
authors' aim was to determine whether S-nitroso-N-acetylpenicillamine (SNAP), a
stable S-nitrosothiol compound, could reverse vasospasm in an experimental
vasospasm model in rabbit. Experimental subarachnoid haemorrhage (SAH) was
induced in 37 New Zealand white rabbits. The animals were divided into four
groups. Control (no SAH), SAH only, SAH plus saline and SAH plus SNAP. SNAP (15
micrograms/kg/min) or 0.09% saline (equal volume) was infused 46 hours after
induction of SAH. All animals were killed by perfusion fixation 48 hours after
SAH occurred. Basilar arteries were removed, sectioned and their cross sectional
areas were evaluated in a blind manner, by light microscopy and by using computer
assisted morphometry. Experimental SAH elicited vasospasm in all animals of SAH
only and SAH plus saline group. In animals treated with SNAP, arterial narrowing
was markedly attenuated without producing systemic hypotension. This widening
achieved statistical significance when compared to the arteries of the SAH only
and SAH plus saline group (p < 0.01). This study indicates that the NO donor SNAP
is a potentially useful drug to reverse cerebral vasospasm due to SAH.
PMID- 10672305
TI - Experimental study of intracisternal administration of tissue-type plasminogen
activator followed by cerebrospinal fluid drainage in the ultra-early stage of
subarachnoid haemorrhage.
AB - This experimental study evaluated the effect of intrathecal injection of tissue
type plasminogen activator followed by cisternal drainage in the ultra-early
stage of aneurysmal subarachnoid haemorrhage to prevent vasospasm. Twenty
Japanese white rabbits were divided into five groups. Either tPA (groups A, B,
and E) or saline (groups C and D) was injected intrathecally 1 hour (groups A, B,
C, and D) or 21 hours (group E) after the intrathecal injection of blood.
Cerebrospinal fluid was drained 2, 4, and 6 hours after the intrathecal injection
of blood (groups A, C, and E). On day 4, the angiographic caliber of the basilar
artery in each group was as follows (mean +/- SD): A, 85.9 +/- 5.0%; B, 74.6 +/-
5.3%; C, 69.1 +/- 2.7%; D, 64.0 +/- 4.9%; E, 80.2 +/- 2.7% (compared with
baseline). In the two groups in which CSF was drained (groups A and C),
fibrinolysis with tPA significantly suppressed vasospasm. In the two groups
treated with tPA (groups A and B), cisternal drainage significantly suppressed
vasospasm. In the two groups treated with saline (groups C and D), however,
cisternal drainage did not suppress vasospasm. Examination of the series of CSF
samples (groups A and C) showed that fibrinolysis with tPA effectively cleared
clots early. In the two groups treated with tPA and CSF drainage (groups A and
E), early removal of subarachnoid clots reduced the degree of vasospasm. Early
fibrinolysis with tPA and early removal of subarachnoid clots by drainage is
effective for preventing vasospasm.
PMID- 10672306
TI - Ganglioside profiles in human gliomas: quantification by microbore high
performance liquid chromatography and correlation to histomorphology and grading.
AB - The composition and the content of gangliosides changes during physiological
growth and differentiation as well as in neoplastic cell transformation. In order
to determine if ganglioside profiles correlate with brain tumour malignancy, the
ganglioside distribution was determined in 31 gliomas of astrocytic origin and in
non-tumour tissue by a recently developed microbore high performance liquid
chromatography (HPLC) method. Glioma malignancy was graded according to the
grading system proposed by the World Health Organization (WHO) in 1993. In
general, an increase of GD3 and a decrease of normal brain gangliosides
correlated with a higher grade of malignancy. Pilocytic astrocytomas Grade I had
a distinctive ganglioside profile, histologically as well as biochemically.
Although they are low-grade gliomas, the pilocytic astrocytomas exhibited a GD3
content comparable to anaplastic gliomas and could only be biochemically
distinguished from other tumour grades by relatively high type "b" ganglioside
levels. Thus, ganglioside composition not only reflects anaplasia but can also be
used to indicate biological characteristics of tumours of different histogenetic
origin.
PMID- 10672307
TI - Cerebellopontine angle lipoma: case report and review of the literature.
AB - Intracranial lipomas located in the cerebellopontine angle are extremely rare.
These tumours are mal-developmental lesions which can cause slowly progressive
neurological symptoms. The clinical management of these tumours differs
significantly from other lesions in this region. A 27 year old woman presented
with a 2-month history of vertigo and a slowly progressive deterioration of
hearing in the left ear. Computed tomography (CT) revealed a large low-density
mass in the left cerebellopontine angle without any contrast-enhancement. In T1
weighted magnetic resonance imaging (MRI) the lesion was hyper-intense and did
not enhance after application of gadolinium. Areas of lower signal intensity
inside of the lesion were suggested as incorporated cranial nerves. A left retro
sigmoidal approach in a semi-sitting position was chosen to expose the tumour.
After reducing the tumour mass, the tumour was dissected from the cranial nerves
which were incorporated into the tumour. The residual tumour was adherent to the
brain stem and the encased lower cranial nerves, allowing only a near subtotal
resection of the highly vascularized tumour in order to avoid neurological
deficits. The histological examination revealed a lipoma. Attempts at complete
removal of cerebellopontine angle lipomas usually result in severe neurological
deficits. Conservative treatment should therefore be preferred. Limited surgery
is indicated if the patients suffer from disabling neurological symptoms and
signs e.g., vertigo, nausea, trigeminal neuralgia, facial weakness or facial
spasm.
PMID- 10672308
TI - Replantation of a totally avulsed scalp without microvascular anastomosis.
PMID- 10672309
TI - Malignant non-Hodgkin lymphoma presenting as a nerve root tumour.
PMID- 10672310
TI - Simultaneous transcranial and endoscopic transnasal approach for recurrent huge
pituitary adenoma.
PMID- 10672311
TI - Transient mutism after brain stem infarction.
PMID- 10672312
TI - Referring to the posterior fossa cranioectomy and tonsillar resection in order to
treat Chiari I malformation with syringomyelia.
PMID- 10672313
TI - Selective distribution of matrix metalloproteinase-3 (MMP-3) in Alzheimer's
disease brain.
AB - A growing amount of evidence indicates that matrix metalloproteinases (MMPs) may
play an important role in the pathogenesis of Alzheimer's disease (AD).
Stromelysin-1 (MMP-3) plays a central role in activating latent-type MMPs, which
are originally secreted as proenzymes. We examined MMP-3 immunoreactivity in the
brains of patients who had suffered from Alzheimer's disease and in those of
neurologically normal persons. The interstitium between myelinated axons and
astrocytes in the white matter of all brain tissues, and senile plaques in the
gray matter of the patients with AD were stained with a monoclonal antibody to
MMP-3. Comparison of the number of senile plaques stained with the antibody
against MMP-3 in the parietal cortex with that in the hippocampus showed that
fewer plaques were stained in the hippocampus. The selective distribution of MMP
3 in the human brain suggests that MMP-3 might play an important role in the
pathogenesis of AD, especially in the degradation of beta-amyloid protein.
PMID- 10672314
TI - Differential expressions of protein kinase C isozymes during proliferation and
differentiation of human skeletal muscle cells in vitro.
AB - The mechanism of skeletal muscle regeneration in vivo can be well modeled in
vitro by culturing skeletal muscle cells. In these cultures mononuclear satellite
cells fuse to form polynuclear myotubes by proliferation and differentiation. The
aim of this study was to determine how the different protein kinase C (PKC)
isozymes were expressed during differentiation of human skeletal muscle in vitro.
The expressions of desmin, used as a muscle-specific intermediate filament
protein marker of differentiation, and of different PKC isozymes were detected by
single and double immunohistochemical labeling, and by Western blot analysis. In
skeletal muscle cells we could identify five PKC isozymes (PKC alpha, -gamma,
etha, -theta and -zeta). The expressions of PKC alpha and -zeta did not change
significantly during differentiation; their levels of expression were high in the
early immature cells and remained unchanged in later phases. In contrast, the
expression levels of PKC gamma and -etha increased with differentiation.
Furthermore, the cellular localization of PKC gamma markedly altered during
differentiation, with a perinuclear-nuclear to cytoplasmic translocation. The
change in the level of expression of PKC theta during differentiation showed
different pattern; its expression was high during the early phases, but a
decreased immunostaining was detected in the matured, well-differentiated
myotubes. We conclude, therefore, that cultured human skeletal muscle cells
possess a characteristic PKC isozyme pattern, and that the different phases of
differentiation are accompanied by different expression patterns of the various
isozymes. These data suggest the possible functional and differential roles of
PKC isozymes in human skeletal muscle differentiation.
PMID- 10672315
TI - Morphological alterations of the choroid plexus in late-onset Alzheimer's
disease.
AB - Anomalies of the cerebrospinal fluid flow rate and composition that have been
reported in patients suffering from Alzheimer's disease (AD) could be related to
alterations of the choroid plexuses (CD). Here we report a photonic and electron
morphometric study in which we compared the height of CP epithelial cells and the
thickness of their basement membrane on post-mortem samples from AD patients, age
matched controls and two newborns. Ageing appeared associated with epithelial
atrophy and basement membrane thickening, but these features were significantly
accentuated in AD. These data suggest that a dramatic alteration of the secretion
and filtration could be involved in the multiparametric pathogenesis of late
onset AD.
PMID- 10672316
TI - Time course of ultrastructural changes and immunoelectron microscopic
localization of neurocalcin in motor endplates of the lumbrical muscles of rats
given a single administration of 2,5-di(tert-butyl)-1,4-hydroquinone.
AB - A time-course study of ultrastructural changes and immunoelectron microscopic
localization of neurocalcin was performed on motor endplates of the lumbrical
muscles of female Wistar rats given a single oral administration of 2,5-di(tert
butyl)-1,4-hydroquinone (DTBHQ) at a dose of 120 mg/kg. Toxic signs such as
salivation and muscle weakness of the hind legs appeared from 3 h after DTBHQ
administration. No remarkable macroscopic or light microscopic changes were noted
in the lumbrical muscles of the treated rats. At the ultrastructural level,
neurotoxicity characterized by a decreases or loss of synaptic vesicles and
mitochondria was observed after 24 h and at the 1-week time point, nerve endings
had disappeared in some of the motor endplates, while many neurite nerve endings
suggestive of early stage regeneration were apparent. After 6 weeks, newly formed
reinnervated endplates were observed. Immunoelectron microscopically, the
synaptic vesicle membranes were heavily labeled for neurocalcin in the control
rats, but not at 24 h after DTBHQ treatment. Synaptic vesicle membranes in the
DTBHQ group were weakly labeled at 1 week, but strongly at 6 weeks. The results
strongly suggest that DTBHQ targets the motor endplates in the rat lumbrical
muscles, causing depletion of neurocalcin in the synaptic vesicles followed by
their loss.
PMID- 10672317
TI - Tissue tears in the white matter after lateral fluid percussion brain injury in
the rat: relevance to human brain injury.
AB - A characteristic feature of severe diffuse axonal injury in man is radiological
evidence of the "shearing injury triad" represented by lesions, sometimes
haemorrhagic, in the corpus callosum, deep white matter and the rostral brain
stem. With the exception of studies carried out on the non-human primate, such
lesions have not been replicated to date in the multiple and diverse rodent
laboratory models of traumatic brain injury. The present report describes tissue
tears in the white matter, particularly in the fimbria of Sprague-Dawley rats
killed 12, 24, and 48 h and 7 days after lateral fluid percussion brain injury of
moderate severity (2.1-2.4 atm). The lesions were most easily seen at 24 h when
they appeared as foci of tissue rarefaction in which there were a few
polymorphonuclear leucocytes. At the margins of these lesions, large amounts of
accumulated amyloid precursor protein (APP) were found in axonal swellings and
bulbs. By 1 week post-injury, there was macrophage infiltration with marked
astrocytosis and early scar formation. This lesion is considered to be due to
severe deformation of white matter and this is the first time that it has been
identified reproducibly in a rodent model of head injury under controlled
conditions.
PMID- 10672318
TI - New haplotype of familial Creutzfeldt-Jakob disease with a codon 200 mutation and
a codon 219 polymorphism of the prion protein gene in a Japanese family.
AB - We report a new haplotype of familial Creutzfeldt-Jakob disease (CJD) with a
codon 200 mutation and a codon 219 polymorphism of the prion protein gene in a
Japanese family. There were four cases diagnosed with CJD neuropathologically,
one of which was identified with a codon 200 mutation (glutamic acid to lysine)
and a codon 219Lys polymorphism on the same allele. Clinicopathologically, two
cases had a long clinical course, whereas the others were similar to the cases
with a codon 200 mutation. Three cases was diagnosed with the panencephalopathic
type CJD neuropathologically and the other was diagnosed with the subacute
spongiform encephalopathy, a subtype of CJD. We consider that the
clinicopathological features in familial CJD are not steadily uniform and that it
is impossible to state definitely from this study whether the codon 219
polymorphism influences the clinicopathological aspects in familial CJD with a
codon 200 mutation (glutamic acid to lysine).
PMID- 10672319
TI - Glial cell line-derived neurotrophic factor (GDNF) and its receptor (GFR-alpha 1)
are strongly expressed in human gliomas.
AB - Glial cell line-derived neurotrophic factor (GDNF), a sequence-related factor of
the transforming growth factor-beta family, has been identified as a potent
neurotrophic factor for a variety of neuronal cell populations. At present, it is
still unknown whether human gliomas in vivo are also capable of producing GDNF.
We studied the expression of GDNF in 14 human glioblastomas, 1 gliosarcoma and 5
astrocytomas. Using an enzyme-linked immunosorbent assay, the amount of GDNF was
quantified in human gliomas and compared to GDNF-expression in C6 glioma cells,
mouse fibroblasts and normal human and rat brain. Mean concentration of GDNF in
gliomas was 937 +/- 140 pg GDNF/g tissue (n = 20). C6 cells revealed the highest
expression levels of 2,837 +/- 813 pg/g, whereas mouse 3T3 fibroblasts showed no
detectable GDNF protein. Mean GDNF tissue levels in normal human and rat brain
were significantly lower. Using reverse transcriptase-polymerase chain reaction,
GDNF mRNA was detected in human gliomas and in rat C6 cells. Immunohistochemistry
revealed strong GDNF- and GDNF receptor-alpha 1-expressing tumor cells in human
glioma tissue. These results show that glial tumors, even in the most
dedifferentiated form of glioblastoma, express GDNF at concentrations up to five
times higher compared to normal human brain. This overexpression of GDNF may be
of biological relevance for proliferation of glial tumors in humans.
PMID- 10672320
TI - Up-regulation of the hyaluronate receptor CD44 in canine distemper demyelinated
plaques.
AB - CD44 antigen (CD44), the principle cell surface receptor for hyaluronate, is up
regulated in the human demyelinating disease multiple sclerosis on fibrous
astrocytes. As astrocytes are the main target cell of canine distemper virus
(CDV), the consequences of a CDV infection on the CD44 expression and
distribution in brains with spontaneous demyelinating canine distemper
encephalitis (CDE) were of interest. Thirteen acute, 35 subacute, and 11 chronic
plaques of nine dogs with immunohistologically confirmed CDE and brains of
control dogs were included in the study. For light microscopy, 5-micron-thick
serial sections were stained with H&E and incubated with monoclonal antibodies
(mAbs) against CD44 and canine distemper virus nucleoprotein and polyclonal
antibodies (pAbs) against glial fibrillary acidic protein (GFAP) and myelin basic
protein (MBP). For immunoelectron microscopy, 90-nm-thick sections were double
stained with anti-GFAP and anti-CD44 mAbs to specify CD44-expressing structures.
In controls, CD44 was diffusely distributed in the white matter and single
meningeal cells exhibited a marginal expression of the antigen. In acute and more
prominently in subacute demyelinating encephalitis, there was a plaque-associated
up-regulation of CD44 which paralleled GFAP. In chronic demyelinating lesions, a
reduction of CD44 associated with a loss of GFAP-positive astrocytes was noted.
Additionally, in chronic plaques, CD44 was expressed on the cell membrane of
perivascular mononuclear cells. Immunoelectron microscopically, in controls, CD44
was rarely demonstrated on astrocytic cell processes. In contrast, in brains with
CDE CD44 was found on the cell membrane of broadened astrocytic cell processes.
In summary, CD44 is up-regulated on astrocytes in the early phase of CDE and
seems to represent a marker for the activation of immune cells in the late phase
of the infection.
PMID- 10672321
TI - Microglial and astrocytic reactions prior to onset of thalamic cell death after
traumatic lesion of the rat sensorimotor cortex.
AB - The temporospatial relationship between microglial and astrocytic reactions and
delayed thalamic cell death was examined 1-7 days following a traumatic cold
lesion of the rat sensorimotor cortex using immunocytochemistry in combination
with terminal deoxynucleotidyltransferase-mediated biotinylated dUTP nick end
labeling (TUNEL) of nuclear DNA fragmentation. No or only occasional TUNEL
positive cells were found in the thalamic relay nuclei up to 3 days after trauma.
After 7 days, on the other hand, a considerable number of TUNEL-positive cells
were seen in the ventrobasal, the ventrolateral and posterior thalamic nuclei.
Already 3 days after trauma, i.e., before cell injury was detectable, many
protoplasmic astrocytes, which were reactive for glial fibrillary acidic protein,
and ramified microglia, which were positive for complement receptor type 3b
(CR3b) but negative for major histocompatibility complex (MHC) class II antigen,
were noticed in the thalamus. The number of labeled astro- and microglia further
increased after 7 days, when DNA fragmentation became evident. At this time, the
morphology of microglia shifted towards bushy and rod-like cells, and microglia
became also reactive for MHC class II antigen. Clusters of CR3b- and MHC class II
positive microglia were found in the ventrobasal thalamus. The present findings
demonstrate that trauma-induced microglial and astrocytic reactions appear in the
thalamus prior the onset of cell damage.
PMID- 10672322
TI - alpha-Synuclein is expressed in a variety of brain tumors showing neuronal
differentiation.
AB - alpha-Synuclein is presynaptic nerve terminal protein and its immunoreactivity
has been observed in such neurodegenerative structures as senile plaques of
Alzheimer's disease or Lewy bodies of Parkinson's disease. The physiological role
of alpha-synuclein is still unknown. It is speculated that alpha-synuclein may be
expressed in brain tumors, especially in those showing neuronal differentiation.
We examined the immunohistochemical localization of alpha-synuclein in 77 human
brain tumors. alpha-Synuclein was widely distributed in the brain tumors showing
neuronal differentiation. As a result, positive immunostaining for alpha
synuclein was observed in ganglioglioma, medulloblastoma, neuroblastoma,
primitive neuroectodermal tumor, pineocytoma/pineoblastoma, and central
neurocytoma. Compared with other neuronal markers, the positive ratio of alpha
synuclein was not as high as synaptophysin, microtubule-associated protein 2,
neuron-specific enolase and tau, but it was higher than neurofilament and
chromogranin A. The expression of synaptophysin was diffusely observed in the
cytoplasm, cellular processes and nucleus in tumors showing neuronal
differentiation; however, the expression of alpha-synuclein was predominantly
observed in the cytoplasm of the tumors as well as in the cellular processes. On
the other hand, non-neuronal brain tumors such as astrocytic tumors or
meningiomas were totally negative for alpha-synuclein. In conclusion, the
appearance of an alpha-synuclein-positive structure was not limited to
neurodegenerative diseases, but could also be detected in neoplastic cells
showing neuronal differentiation.
PMID- 10672323
TI - Distribution of enzyme-bearing cells in GM2 gangliosidosis mice: regionally
specific pattern of cellular infiltration following bone marrow transplantation.
AB - Tissue distribution of beta-hexosaminidase was investigated using 5-bromo-4
chloro-3-indolyl N-acetyl beta-D-glucosaminide (X-Hex) as substrate in wild-type
mice, four GM2 gangliosidosis model mice (Hexa-/-, Hexb-/-, Gm2a-/- and Hexa-/
Hexb-/-) and Hexb-/- mice that received bone marrow transplantation (BMT). In
wild-type mice histochemical localization of beta-hexosaminidase was detected in
the perikarya of the majority of neurons, small process-bearing microglial cells,
perivascular macrophages, and macrophages in the choroid plexus and
leptomeninges. X-Hex positivity was also noted in the renal tubular epithelium
and macrophages in the liver and spleen. The staining pattern in the Gm2a-/- and
Hexa-/- mice was generally similar to those of wild type, but in these mice, X
Hex stain was also noted in some storage neurons with swollen perikarya. No X-Hex
positive cells were detected in Hexb-/- or Hexa-/-Hexb-/- (DKO) mice. In Hexb-/-
mice that received wild-type BMT (Hexb-/- +WBMT), many X-Hex-positive cells were
detected in the spleen, and to a far lesser extent, in liver and kidney. In the
CNS of these mice, X-Hex-positive cells were largely detected in the
leptomeninges and choroid plexus. Some positive cells were also detected, mostly
in the perivascular regions of the cerebrum, in particular in the regions of the
posterior thalamus, brain stem and spinal cord. Some of X-Hex-positive cells were
immunoreactive with Mac-1 and F4/80 antibodies and, thus, were cells of
microglia/macrophage lineage. X-Hex-positive staining was not detected in neurons
in these mice despite clinical improvement following BMT. This is the first time,
as far as we know, that the regional distribution of the donor cells in the CNS
has been investigated in a model of neuronal storage disease. Our study indicated
that donor-derived cells of microglia/macrophage lineage infiltrated the CNS in a
regionally specific manner following the BMT.
PMID- 10672324
TI - Postnatal profiles of myogenic regulatory factors and the receptors of TGF-beta
2, LIF and IGF-I in the gastrocnemius and rectus femoris muscles of dy mouse.
AB - The dystrophin-deficient mdx mouse presents muscle fiber necrosis but active
muscle regeneration, probably due to an extensive recruitment of myogenic
regulatory factors (MRF), several growth factors and cytokines, and favorable
interaction of satellite cells. In contrast, the laminin alpha 2 (merosin)
deficient dy mouse shows progressive muscle fiber necrosis and ineffective muscle
regeneration. Using Western blot and immunohistochemical analyses, we
investigated the adaptive changes in MRF, growth factors and cytokines and their
receptors in the muscles of dy mice during postnatal growth. The relative volume
of MyoD, myogenin and Myf-5 proteins was markedly lower in the gastrocnemius and
rectus femoris muscles of dy mice. Transforming growth factor-beta 2, leukemia
inhibitory factor (LIF) and basic fibroblast growth factor were not up-regulated
in the muscles of dy mice. The levels of the LIF receptor and insulin-like growth
factor-I receptor levels were markedly decreased in the muscles of dy mice during
the entire postnatal period observed in this study. Therefore, unlike the
situation in mdx mice, the milieu of regeneration following repetitive damage
seems to be degraded in the muscles of dy mice.
PMID- 10672325
TI - The adaptive response of transforming growth factor-beta 2 and -beta RII in the
overloaded, regenerating and denervated muscles of rats.
AB - Using a muscle cell line and satellite cell cultures, it has been shown that
transforming growth factor-beta (TGF-beta) has a powerful inhibitory effect on
myoblast replication and differentiation. However, little work has been done on
the possible role of TGF-beta in adult muscle in vivo. Using Western blot and
immunohistochemical analyses, we investigated normal distribution of TGF-beta 2
and TGF-beta RII proteins between slow and fast-type muscles, and the adaptive
response of these proteins in the mechanically overloaded muscles, in the
regenerating muscles following bupivacaine injection and in the denervated muscle
after section of sciatic nerve. Slight TGF-beta 2 immunoreactivity was detected
both in slow- and fast-type muscles of mature rat. The amount of TGF-beta RII
protein was markedly greater in fast-type muscles. In the overloaded muscle,
immunohistochemical analysis showed a marked increase in TGF-beta 2
immunoreactivity in the mononuclear cells (probably endothelial and perithelial
or smooth muscle cells of endomysial capillaries) of the extracellular space at 3
and 6 days post surgery. Rapid increase of TGF-beta 2 protein and concomitant
decrease of the receptor (TGF-beta RII) were observed in the mechanically
overloaded and regenerating muscles. On the other hand, denervation of slow- and
fast-type muscles showed a rapid increase in TGF-beta 2 protein, but did not
elicit a concomitant decrease of TGF-beta RII. These results indicate that TGF
beta RII is preferentially distributed in fast-type muscles. Furthermore, TGF
beta 2 may play an important role in muscle hypertrophy and regeneration by the
usage of TGF-beta RII.
PMID- 10672326
TI - Single-fiber analysis of mitochondrial A3243G mutation in four different
phenotypes.
AB - Five unrelated patients harboring the A3243G mutation in the mitochondrial DNA
(mtDNA) but presenting with different clinical phenotype were studied for their
percentage of mutation at the single muscle fiber levels. One patient had a
clinically and pathologically defined Leigh syndrome (LS), two showed
mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes
(MELAS), another showed progressive external ophthalmoplegia (PEO), and the other
showed mitochondrial diabetes mellitus (MDM). The mutation load was greater in
the muscle from the patient with LS (92%), who showed more than 80% even in the
non-ragged red fibers (RRF) and also presented the highest proportion of RRF. The
patients with MELAS had lower mutation levels as well as a lower proportion of
RRF, and these two parameters were even lower in the PEO and MDM patients. These
results were consistent with the concept that differences in the mutation load
and in the somatic distribution of the mutation among different cells and tissues
are responsible for the differences in phenotypical expression of the disease.
PMID- 10672327
TI - Expression of p67 (Munc-18) in adult human brain and neuroectodermal tumors of
human central nervous system.
AB - p67 (Munc-18), is a neuron-specific protein of 67 kDa, known for its ability to
bind with syntaxin and also to copurify with neuronal cdc2-like kinase. Earlier,
in situ hybridization and immunocytochemical analysis of rat trigeminal ganglion
and hippocampal cells demonstrated the specific localization of p67 in nerve
cells and its rich distribution in axons. In the present study, we have looked
for p67 expression in normal human brain and various neuroectodermal tumors.
Immunohistochemical and Western immunoblot analysis of normal human brain tissue
using antibodies against the N- and C-termini of p67 demonstrated the specific
localization of this protein in postmitotic neurons but not in glia. Among
neuroectodermal tumors, expression of p67 was observed in 100% of the tumors of
neuronal origin studied, especially in the mature neuronal cell population of
these tumors. Western immunoblot analysis of non-neuronal neuroectodermal tumors
failed to reveal the expression of this protein in majority of cases. However, in
gliomas and meningiomas, mild cytoplasmic immunohistochemical staining of
neoplastic cells was noted in 64.7% and 25% of cases, respectively. Observed mild
immunohistochemical staining of these tumors could be due to immunoreactivity to
low molecular weight degraded products of p67, as seen on Western blot. The
findings suggest that p67, by virtue of its ability to be expressed in
postmitotic neurons of adult human brain and in tumors of neuronal origin, may
serve as a molecular tool to understand the growth and differentiation of the
nervous system in general.
PMID- 10672328
TI - Practical measures to simplify the Braak tangle staging method for routine
pathological screening.
AB - The examination of neurofibrillary tangles is now recommended for the diagnosis
of Alzheimer's disease as their location and density can distinguish early,
intermediate and late disease stages. While the Braak tangle staging protocol can
identify these stages, it uses an uncommon silver stain and hippocampal sample.
The present study evaluates the Braak protocol using commonly used methods and
cases fulfilling either CERAD criteria for Alzheimer's disease, criteria for
dementia with Lewy bodies or without neurological disease. Temporal and occipital
cortices from 72 cases were stained using tau immunohistochemistry and the
Gallyas and modified Bielschowsky silver stains. The modified Bielschowsky silver
stain was equivalent to the Gallyas silver stain for tangle staging.
Semiquantitative evaluation of neurofibrillary tangles in the hippocampus and the
inferior temporal cortex provided equivalent information to that obtained using
the original Braak tangle staging protocol (kappa statistic of 0.97). Comparison
of this modification with the CERAD criteria provided moderate agreement (0.51)
between diagnostic categories when cases with dementia with Lewy bodies were
included, but substantially increased agreement (0.74) when they were excluded.
This simplification of the Braak tangle staging protocol is easy to apply, can be
readily incorporated into existing CERAD procedures, and helps to distinguish
cases with neurofibrillary tangles from those with Lewy bodies.
PMID- 10672329
TI - The cerebellar and thalamic degeneration in Fukuyama-type congenital muscular
dystrophy.
AB - We report a male autopsy case of Fukuyama-type congenital muscular dystrophy
(FCMD), with unusual neuropathological findings. The patient was a Japanese man
aged 26 years at the time of death. He had shown severe psychomotor retardation
and muscular dystrophy since early infancy, and was diagnosed as having FCMD at
the age of 5 years. He died of respiratory failure. The main neuropathological
finding was extensive cerebral and cerebellar cortical dysplasia, characteristic
of this disorder. In addition, degeneration of the cerebellar efferent pathway,
including the dentate nucleus, superior cerebellar peduncle, and red nucleus, and
that of the lateral thalamic nucleus were observed. These findings suggest the
possibility that the long survival can clarify the latent neurodegeneration in
the cerebellum and thalamus in FCMD, in addition to congenital malformations. The
system degeneration should be carefully evaluated in the pathological examination
of this disorder.
PMID- 10672330
TI - Eosinophilic inclusions in ependymoma represent microlumina: a light and electron
microscopic study.
AB - A study was undertaken to determine the pathological significance of previously
unrecognized intracytoplasmic eosinophilic inclusions (IEIs) in ependymoma. The
study group consisted of 58 ependymomas, all of which were pathologically
characterized and graded according to the 1993 WHO classification. Electron
microscopic studies were performed in 16 cases. The study showed that 33 (57%)
ependymomas had IEIs and that in 8 cases these were abundant. Round and
eosinophilic, their sizes varied from 10 microns to a tiny dot. Similar
eosinophilic bodies were also observed between tumor cells. The inclusions were
weakly PAS positive. On immunostains, IEIs were frequently positive for glial
fibrillary acidic protein, less often for S-100 protein, and for epithelial
membrane protein and CAM 5.2. They were negative for AE1/AE3, carcinoembryonic
antigen and Ber-EP4. Ultrastructurally, IEIs represented intracytoplasmic lumens
containing microvilli and cilia. These microlumina also frequently contained
granulo-tubular materials. With reference to tumor subtypes, IEIs occurred most
frequently in ordinary and clear cell ependymomas. IEIs were also present in 4 of
6 anaplastic ependymomas studied. In conclusion, IEIs represent microlumina and
occur in more than a half of ependymomas including malignant examples. Their
finding is a helpful diagnostic feature of ependymoma.
PMID- 10672331
TI - Histological and immunocytochemical data on the differentiation of intestinal
endocrine cells in human fetus.
AB - The differentiation of the argyrophil, argentaffin, 5-hydroxytryptamine (5-HT)-,
somatostatin (SOM)-, cholecystokinin (CCK)-, substance P (SP)-, methionine
enkephalin (Met-Enk)- and vasoactive intestinal polypeptide (VIP)-immunoreactive
entero-endocrine cells (EECs) was examined in human fetuses. A great increase in
the frequency of EECs in the duodenum and the rectum was observed between the 7th
and 12th gestation week. The differentiation of the EECs advanced distally in the
small intestine and proximally in the large intestine. In 24-25-week-old fetuses
the frequency of the EECs was also increased in the ileum and the colon. A
different time-course of the appearance and differentiation of the types of EECs
was observed. Met-Enk- and VIP-immunoreactive endocrine cells were not detected
at any age. A regional difference in the frequency and morphology of the
endocrine cell types was observed in the eldest fetuses.
PMID- 10672332
TI - Renal excretory function in conscious Long Evans and vasopressin deficient
(Brattleboro) rats after endothelin-A receptor inhibition.
AB - All experiments were performed on conscious, freely moving male Long Evans as
well as Diabetes incipidus (Brattleboro) rats (300-320 g). The endothelin-A (ETA)
receptor antagonist BQ-123 (Neosystem) was administered through femoral vein
cannula. Arterial blood pressure was measured trough femoral artery catheter. The
bladder was cannulated for urine collection via a small suprapubic incision.
After a 40 min control period BQ-123 infusion (16.4 nmol/kg/min, 25
microliters/min) was started and continued for 50 min. The effect of 32.8
nmol/kg/min BQ-123 infused in conscious Brattleboro rats was also investigated.
Plasma and urine concentrations of sodium, potassium and chloride as well as
osmolality were determined. Glomerular filtration rate (GFR) was estimated using
the clearance of endogenous creatinine. Endothelin-A receptor inhibition by 16.4
nmol/kg/min BQ-123 infusion in conscious Long-Evans rats decreased urine flow
rate by 38.4% (p < 0.02) and increased urine osmolality by 30.3% (p < 0.05).
Sodium, potassium, chloride excretion did not alter. Endothelin-A receptor
inhibition by 16.4 nmol/kg/min and by 32.8 nmol/kg/min BQ-123 infusion in
conscious Brattleboro rats did not produce any change in urine flow rate, urine
osmolality or excretion of the electrolytes studied. Endothelins acting via ETA
receptors may function as an inhibitor of water reabsorption in the kidneys of
conscious rats.
PMID- 10672333
TI - Spectral analysis of heart rate and arterial pressure variability after nitric
oxide synthase inhibition.
AB - The experiments were performed on male, conscious Wistar rats. Femoral arterial
pressure was registered by Statham GOULD P23 ID pressure transducer connected to
MP 100WS BIOPAC work station after analog to digital conversion during 40 minutes
long control period. Nitric oxide synthase inhibition was performed by injection
of 100 microliters, 10 mg/kg b.w. N-omega-nitro-L-arginine methyl ester (L-NAME)
in saline through femoral vein catheter. Twenty minutes later arterial pressure
registration was started and was continued for 40 minutes. The pulse-by-pulse
values of systolic, diastolic and mean arterial pressure as well as the pulse
intervals were measured by peak and rate detectors of the AcqKnowledge 2.0
software. Row data were processed using a virtual instrument developed in our
laboratory in the graphical programming environment Lab VIEW 3.1.1. L-NAME
increased systolic, diastolic and mean arterial pressure by 16.6%, 25% and 35%,
respectively. The PMF/PHF ratio in heart rate spectrum decreased, indicating an
increased vagal effect on the heart. Nitric oxide synthase inhibition increased
the low-frequency component of systolic arterial blood pressure variability by
39.5%. Nitric oxide is a physiological regulator of rapid fluctuations of
arterial blood pressure.
PMID- 10672334
TI - Neuropeptides of the cholecystokinin group: effects and mechanisms of action on
the gastro-intestinal and gall bladder motility.
AB - The neuropeptides of the cholecystokinin (CCK) group belong to the substances
usually referred to as "brain-gut" neuropeptides. They are synthesized in neurons
of the central nervous system, in the peripheral and in the autonomous nervous
systems, in endocrine cells (types "I", "K" and "A"), as well as in the enteric
nervous system of the gastro-intestinal tract and of the pancreas. The CCK-group
peptides realize their effects via several different mechanisms (Fig. 1):
endocrine or neuroendocrine (classic hormonal mechanism)--the peptide, released
by the endocrine cell or by the nerve terminal, is carried by the circulation to
the remote target organs; paracrine or neuroparacrine--the peptide, released in
the intercellular space, reaches the target effector cells via diffusion.
Similarly to the classic neurotransmitters, CCK and its analogues could play a
neurotransmitter role, also modulating the release of acetylcholine (ACh) and of
other neurotransmitters in enteric and CNS neurons. In the present review article
some smooth-muscle and neuromodulatory effects of CCK are described and compared
to the results of the authors' studies on the problem.
PMID- 10672335
TI - Does nitric oxide participate in the mechanism of action of dotarizine?
AB - Behavioral and nociceptive effects of dotarizine (DOT) and other substances
acting on migrainous attacks and nitric oxide (NO) metabolism were studied in
comparative experiments on rats. Behavioral effects were evaluated by the changes
induced in ambulations and rearings of rats in the Opto-Varimex apparatus;
effects on nociception were determined by the changes of pain threshold in
growing mechanical pressure on one of the rat paw. The data showed that (1) NO
did not participate directly in the mechanism of the behavioral actions of DOT. A
role could be ascribed to the modulating influence of DOT on the changes in NO
formation induced by other agents; (2) the NO system did not participate in the
mechanisms of the responses to the painful mechanical pressure on the rat paw;
(3) the behavioral effects of the substances with facilitating or inhibitory
action on the migrainous process (m-CPP and ergotamine) and the influence of
substances proved to affect NO formation (L-arginine, histamine, L-NAME) on these
effects suggest a role for NO as a modulating but not a basic factor in the
mechanisms of action of these pro- and antimigrainous substances; and (4) the
behavioral effects of DOT were similar to the effects of the antimigrainous drug
ergotamine and different from the promigrainous drug meta-chlorophenyl-piperazine
(m-CPP)--which suggest an antimigrainous activity of dotarizine.
PMID- 10672336
TI - An apparatus for measuring the optical density of human ocular media to blue
light.
AB - The paper describes an apparatus constructed by the authors and aimed at
evaluating the optical density of human ocular media by a non-invasive
psychophysical method described previously (Sample et al. 1988). The device has
two light sources within the wavelength bands of 437 +/- 6 nm and 557 +/- 6 nm,
respectively. They are a square-wave alternated at 1 Hz. The radiance of each can
be controlled by the subject and adjusted at visibility threshold or at
subjective equiluminance. Upon scotopic vision, the ratio between the two
thresholds (or ratio of radiances at equiluminance) is a function of the ocular
optical density at the short wavelength. The psychophysical procedures of
adjustment of the 437 nm source at the absolute threshold and at equality with
the 557 nm source had been tested with volunteers aged between 24 and 67 years.
The dependence of blue-light sensitivities on age, obtained with the two
procedures, suggests, in agreement with the literature, two main sources of
sensitivity decline with age: senile myosis and ocular-media density increase at
the short wavelength end of the visible spectrum.
PMID- 10672337
TI - Frog muscle fibre action potential and different extracellular calcium
concentration at lowered pH in the medium.
AB - This article is mainly concerned with the influence of Ca2+[o in acidified
extracellular medium on the intracellular action potentials (ICAPs) and total
ionic current (Ii) during ICAP of isolated skeletal muscle fibre. The bundles of
frog muscle fibres were bathed in Ringer's solution with standard Ca2+[o at pH
6.5 after which the fibres were exposed for 30 min to Ca(2+)-free solution and
Ca(2+)-enriched solution at pH 6.5. The ICAPs in standard Ca2+[o solution
(control) and after exposure for 30 min to Ringer's solutions with different
Ca2+[o at pH 6.5 were recorded and the Ii during ICAP was calculated. The ICAP
amplitude from the fibres in Ca(2+)-free solutions at pH 6.5 showed a significant
increase vs. control, while the time characteristics if the ICAPs in different
Ca2+[o decreased except for the ICAP depolarization phase duration in Ca(2+)
enriched solution. The Ii alterations reflect ICAP changes. It was suggested that
the changed Ca2+[o at pH 6.5 compensated to some extent the observed inhibitory
effect of lowered pH on ICAP parameters in solution with standard Ca2+[o.
PMID- 10672338
TI - The "small" polydisperse cytoplasmic extrachromosomal DNA of chicken leukaemic
myeloblasts and the avian myeloblastosis virus core-bound DNA seem to descend
from origin regions of chromosomal DNA replication.
AB - Nucleotide sequences are presented for 12, 7 and 12 cloned extrachromosomal DNAs
by nature harbored in nucleoprotein (NP) complexes forming chicken leukaemic
myeloblast (CHLM) post microsomal sediment (POMS) components A, B and C,
respectively, and for 11 cloned avian myeloblastosis virus (AMV) DNAs. Analysis
of the abundance of sequence motifs significant for eukaryotic chromosomal DNA
replication origin (ori) regions (and their initiation zones) has shown that
these DNAs are reminiscent of cell DNA fragments enriched in ori sequences (Rao
et al., 1990) and/or sequence features of several eukaryotic chromosomal oris
containing clusters of modular sequence elements (Dobbs et al., 1994).
Accordingly, these DNAs, with an (A + T) content prevalently higher than that of
the total cell DNA, revealed the presence of asymmetrically distributed (A + T)
rich stretches, scaffold attachment region (SAR) T consensuses, polypyrimidine
nucleotide (poly(Py)) tracts and minimal Saccharomyces cerevisiae autonomously
replicating sequence (ARS) consensus, in abundance comparable with that of these
sequences of DNA fragments enriched in oris. All these DNAs were found to be
enriched also in sequence elements held as primase (Pr) attachment sites.
Moreover, DNAs of POMS component B and those of AMV DNA were found to be enriched
in the asymmetric pyrimidine (Py) heptanucleotide motif of Waltz et al. (1996)
occurring in the initiation zones of ori region. Consequently, these
extrachromosomal DNAs, portion of which represents a precursor of AMV DNA, seem
to descent from initiation zones of various ori regions of an early replicating
chromosomal myeloblast DNA. In addition, a possible explanation of the
inclination of these DNAs to form multimers is presented.
PMID- 10672339
TI - Resistance to Friend leukemia virus in transgenic mice expressing the native Fv-4
gene.
AB - Fv-4 is a truncated ecotropic retrovirus gene that codes for an envelope protein
under control of a cellular promoter. It confers resistance to ecotropic murine
leukemia viruses. Transgenic mice were derived using the native Fv-4 gene as the
construct for microinjection. Two founder mice were derived. In both founder
lines, there was no detectable expression of the transgene or resistance to
Friend murine leukemia virus (FrMLV) in hemizygotes. In one line, the resistance
was observed in homozygotes with Fv-4 RNA formation in the thymus but not in the
spleen or in other tissues. In the other founder line, a homozygous male was
identified. Double integrants, derived from breeding this homozygous male to
homozygous females from the other founder line, were also resistant. These
results indicate that the native gene confers the resistance in homozygous
transgenic mice or double integrants derived from different founders but not
hemizygotes.
PMID- 10672340
TI - A Fe(3+)/DNA complex induces an anti-human immunodeficiency virus factor(s) in
CD4+ lymphocyte cell lines.
AB - Numerous cytokines and chemokines are involved in inflammatory and immune
response. Whereas some of them inhibit virus replication in vitro directly or
increase the patients' T4-lymphocyte level, others effects are not so clear.
Using human immunodeficiency virus (HIV) and cell cultures we have studied the
antiviral effect of complexes of salmon DNA with metals and of a new factor(s)
(antiviral factor, AVF) induced in cells by the complexes. The Fe3+/DNA complex
possessed the highest antiviral activity. It was found that MT-2, MT-4, CEM and
Jurkat cells treated with the complexes secreted AVF which inhibited the
replication of nine HIV-1 isolates, was noncytotoxic and stimulated cell
proliferation. AVF did not inactivate HIV. The molecular mass analysis of AVF
showed that its antiviral activity is associated with its fraction of M(r) of 3
K. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of mRNA from
MT-4 cells treated with the complexes showed an increase in the the expression of
genes for interleukin-1 alpha (IL-1 alpha), tumour necrosis factor alpha (TNF
alpha) and TNF-beta while expression of genes for IL-1-beta, IL-2, IL-4, IL-6, IL
8. IL-10, IL-12; 35p, 40p, IL-13, GMCSF, GSF and RANTES was not detected at all.
However, the anti-HIV activity of the cell culture supernatant in vitro cannot be
explained by mere presence of the inflammatory substances mentioned above,
because they do not possess such activity and their M(r) is higher than that of
AVF. Our findings raise the possibility that AVF(s) may be involved in the
mechanism of cell resistance against HIV.
PMID- 10672341
TI - Accumulation of helper component/proteinase and coat protein of turnip mosaic
virus in intact plants.
AB - The helper component/proteinase (HC/Pro) protein of turnip mosaic virus (TuMV)
was fused with glutathione S-transferase (GST) and expressed as a fusion protein
in Escherichia coli. The quality of antiserum raised against the GST-HC/Pro
fusion protein was compared to that of antiserum raised against coat protein (CP)
by image analyser. The result showed that these antisera were of similar quality.
Then the both antisera were used to follow the time course of accumulation of
HC/Pro protein and CP in intact TuMV-infected leaves. CP appeared first at day 3
post inoculation (p.i.) and gradually accumulated in uninoculated upper leaves,
whereas HC/Pro protein appeared first at day 4 p.i., accumulated up to day 7 p.i.
and then gradually decreased. Potyvirus proteins are encoded by a single
translation unit spanning most of the genome and are presumably synthesized in
equimolar ratios. Therefore, the reduced accumulation of HC/Pro protein in
relation to CP at one month p.i. in infected plants is presumed to be the result
of its degradation.
PMID- 10672342
TI - Interaction of V-Myb oncoprotein with spread chromatin of avian haematopoietic
cells.
AB - Interactions of v-Myb oncoprotein with spread chromatin of avian LSCC-BM2 cells
expressing v-myb oncogene were studied by means of immunoelectron microscopy. The
application of this technique using anti-Myb polyclonal antibody combined with
the Miller type spreading for visualisation of chromatin revealed the presence of
Myb protein on stretched chromatin fibres. Intense labelling was apparent on the
chromatin dispersed by hypotonic treatment, where the label was present
frequently in clusters, although individual marks along the fibrillar molecules
were also found. The combination of hypotonic and detergent treatment resulted in
better dispersal of chromatin, more frequent detection of active transcription
units, but also in removal of some proteins from chromatin fibres. The labelling
of chromatin with anti-Myb antibody was substantially reduced in this case and
was dependent on detergent concentration used. The marker was found less
frequently on chromatin fibres usually present in clusters on remaining protein
structures. Our findings confirmed direct interaction of v-Myb protein with
chromatin structure. This interaction is apparently affected by detergent
treatment.
PMID- 10672343
TI - Detection of single-stranded cohesive ends in the genome of Bacillus
thuringiensis temperate phage KK-88.
AB - Cohesive ends (cos sites) were detected in the genome of temperate KK-88 phage in
Bacillus thuringiensis after analysis of the phage DNA generated by the 3'-5'
exonuclease activity of Klenow fragment of DNA polymerase I. In addition, unlike
the 5'-protruding ends of coliphage lambda genome, the ends of KK-88 phage genome
were found to be 3'-protruding. The restriction map of the phage genome was also
constructed on the basis of position of the cos fragments.
PMID- 10672344
TI - A note on outbreaks caused by mixed foot-and-mouth disease virus infections.
AB - Two outbreaks of foot-and-mouth disease (FMD) in vaccinated cattle were
investigated wherein a mixed infection due to FMD virus (FMDV) types O and Asia 1
was detected by sandwich enzyme-linked immunosorbent assay (ELISA) and confirmed
by antigen capture polymerase chain reaction (PCR). The clinical picture and the
epidemiological data on these outbreaks are presented. The isolated virus strains
were compared to the respective vaccine strains by means of monoclonal antibody
(MAb) profiling and nucleotide sequence analysis. The probable cause of the mixed
FMDV infection and its significance in disease control are discussed.
PMID- 10672345
TI - Genetic homogeneity of human serotype G1 rotaviruses isolated during a single
epidemic season: implications for vaccine strategies.
AB - The extent of genetic variation of rotavirus isolates representing the common
serotype G1 circulating in Australian urban centres during 1996 was investigated.
The sequences of the major outer capsid glycoprotein, VP7, of three isolates from
Brisbane, Sydney and Melbourne were determined and found to be highly conserved
(> 99% nucleotide identity, > 98.3% amino acid identity and > 99% amino acid
similarity). In particular, the sequences of the neutralisation epitope regions
were absolutely conserved. These strains and those from other cities were
analysed by Northern blot hybridisation using a probe derived from a prototype
serotype G1 virus. For all strains, the eleven genomic RNA segments hybridised
with the probe indicating that these strains were not derived from genetic
reassortment between different rotavirus geno-groups. These results suggest that,
within a single epidemic season, rotavirus strains circulating in geographically
diverse communities share common genetic features.
PMID- 10672346
TI - Nucleotide sequences of the cylindrical inclusion protein genes of two Japanese
zucchini yellow mosaic virus isolates.
AB - The nucleotide sequences of the cylindrical inclusion protein (CIP) genes of two
Japanese zucchini yellow mosaic virus (ZYMV) isolates (ZYMV-169 and ZYMV-M) were
determined. The CIP genes of both isolates comprised 1902 nucleotides and encoded
634 amino acids containing consensus nucleotide binding motif. The sequence
similarities between the two isolates at the nucleotide and amino acid levels
were 91% and 98%, respectively. When the CIP gene sequences of the Japanese ZYMV
isolates were compared with those of previously reported ZYMV isolates, the
nucleotide and amino acid sequence similarities ranged between 81% and 97%, and
between 95% and 97%, respectively. Phylogenetic analysis of the deduced amino
acid sequences of the CIP genes indicated that the Japanese ZYMV isolates were
closely related to those of other ZYMV isolates.
PMID- 10672347
TI - Immunogenicity of interferon-alpha 2 in therapy: structural and physiological
aspects.
AB - Recombinant human interferon (rIFN)-alpha 2 has been approved for therapeutic
application in a range of human oncological and viral diseases. However, some
patients can develop strictly specific antibody response to rIFN-alpha 2, which
may diminish its therapeutic potential. Such humoral response appears to be quite
complex and obviously depends on multiple parameters. Our review is aimed
primarily to factors associated with structural modifications of rIFN-alpha 2
that we consider crucial for formation of therapy-induced antibodies. These
factors are either related to inherent conformational differences between three
IFN-alpha 2 subvariants or to immunogenically active contaminating derivatives
resulting from production, purification and storage of this recombinant protein.
In addition, the role of treatment regimen and physiological variables modulating
the immune response to rIFN-alpha 2 in the challenged organism are mentioned.
PMID- 10672348
TI - [Stoke: acute emergency, not fatal disease].
PMID- 10672349
TI - [Preclinical treatment of patients with stroke].
AB - Stroke is the third leading cause of death and number one cause of disability in
industrialised countries. Studies into the pathophysiology of acute ischaemic
stroke have indicated that treatment options are likely to be optimized when
early signs of stroke are recognized and treatment is initiated within 3 hours
from symptom onset. Therefore, new conceptions heading towards early diagnosis,
fast preclinical treatment, structured diagnostics, immediate initiation of acute
therapy as well as early initiation of rehabilitation are required. It is well
known that, for most patients, there is a long delay between the onset of
symptoms and the start of therapy. Many factors are responsible for the time
delay:signs and symptoms often go unrecognized and/or are minimized by patients,
relatives and bystanders. Unlike trauma or myocardial infarction, stroke is not
given a high priority by medical staff and/or emergency medical services (EMS).
Although a small number of stroke patients is treated as emergency and attended
to by the emergency medical services within this time window, this number could
easily be increased by intensified public and emergency personnel education. At
present the standard of care by the EMS personnel includes adequate cerebral
oxygenation, treatment of cardiac arrhythmia, management of hypertension as well
as therapy of hyperglycemia and hyperthermia. For the future, we hope that
emergency medical services will be able to initiate therapies which must be
administered within the first few hours of acute stroke after onset of symptoms.
Early notification of hospitals would enable a particular stroke team to be
present at the patient's admission.
PMID- 10672350
TI - [Respiratory pattern and respiratory strain in automatic tube compensation and
inspiratory pressure support].
AB - STUDY OBJECTIVE: To investigate whether automatic tube compensation (ATC) or
conventional pressure support (PS) is suitable to compensate for the work of
breathing imposed by the breathing circuit without altering the breathing
pattern. METHODS: Breathing pattern and work of breathing were measured in
healthy volunteers. After a 20 min period of quiet breathing through a mouth
piece (control) the volunteers were breathing through a 8.0 mm ID endotracheal
tube (ETT) with four different settings: CPAP at 0 mbar, ATC, PS 5 mbar, PS 10
mbar. Each mode was applied for a 20 min period. At the end of each period data
from 10 consecutive breaths were analyzed and averaged. Tidal volume (VT),
breathing frequency (f), and minute ventilation (Ve) were determined from the
stored gas flow tracings. Work of breathing was assessed as the pressure time
product (PTP) calculated from the transdiaphragmatic pressure (Pdi) using a
combined esophageal and gastric balloon catheter. RESULTS: During the control
period the breathing pattern was as follows: VT = 882 +/- 277 ml, f = 13.7 +/-
5/min, Ve = 11.5 +/- 4.2 L/min. Maximal Pdi was 9.2 +/- 5.4 mbar and PTP was 11.3
+/- 7.1 mbar x s. Breathing CPAP through the ETT resulted in a slight increase in
Pdi (10.8 +/- 5.4 mbar) and PTP (14.8 +/- 10.4 mbar x s) with an unchanged
breathing pattern. However, for the same amount of unloading from respiratory
workload ATC did not alter the breathing pattern, whereas PS 5 mbar and PS 10
mbar resulted in a clear increase in VT (1014 +/- 202 ml, 1336 +/- 305 ml,
respectively). CONCLUSION: From the presented data in healthy volunteers it might
be concluded that ATC and PS 5 mbar and 10 mbar are suitable modes for unloading
the respiratory system from work imposed by the breathing circuit. ATC does not
alter the breathing pattern in contrast to PS which results in an increased tidal
volume. Therefore, the exact compensation of the work imposed by the ETT during
ATC seems to be advantageous over ATC to assess the actual breathing pattern.
PMID- 10672351
TI - [Intraoperative blood requirements and allogeneic blood transfusion in
cardioanesthesia. Data analysis of 7729 patients in 12 cardiac surgical clinics].
AB - Allogeneic blood requirements in cardiac surgery shows a wide variation even for
comparable procedures. The aim of the present study was to compare the
intraoperative allogeneic blood requirement in defined cardiac operations among
12 cardiac centers in Germany. METHOD: A data set with 25 variables concerning
the intraoperative course in adult cardiac patients with myocardial
revascularization, valve replacement (aortic or/and mitral valve) or combined
procedures was distributed to the participating centers. The data of all patients
between January 1th 1998 and June 30th 1998 were included. Besides demographic
data, the intraoperative transfusion of allogeneic and autologous blood, fresh
frozen plasma and the concomitant hematocrit values were registered. Data were
analyzed for all centers and separated for each center. RESULTS: The data of
7,729 patients were analyzed. The intraoperative allogeneic blood requirement was
0.6 +/- 1.3 units for all patients. It varied among the centers from 0.25 +/- 0.6
units to 0.97 +/- 1.6 units (P < 0.05). The percentage of patients receiving
allogeneic blood was 27% and differed among the centers from 17% to 35%. Female
patients were transfused in 53% (36-39%) compared to male patients with 16% (9
20%) (P < 0.05). The rate of autologous blood predonation varied from 0.5% to
23%. Patients without autologous predonation were transfused in 28% compared to
4% in patients with predonation (P < 0.05). In patients with autologous
predonation the intraoperative transfusion of allogeneic blood was significantly
reduced (0.1 +/- 0.39 vs 0.6 +/- 1.4 units, P < 0.05). However, some centers with
a high percentage of autologous predonation also demonstrated a high rate of
perioperative allogeneic transfusion. CONCLUSION: The incidence of allogeneic
blood transfusion in cardiac surgery depends on the institution and not on the
surgical procedure. A common threshold value of hemoglobin for the transfusion of
blood trigger even for comparable procedures could not be detected among the
centers. Especially in female patients, there was a wide variation in allogeneic
blood transfusion. Autologous blood predonation reduces blood requirement
significantly, however, it is practiced with variing intensity. The data set did
not include information about transfusion regimen in the postoperative period,
thus, these data do not allow to draw conclusions for the whole perioperative
period.
PMID- 10672352
TI - [Postoperative cognition disorders in elderly patients. The results of the
"International Study of Postoperative Cognitive Dysfunction" ISPOCD 1)].
AB - OBJECTIVE: Cognitive dysfunction is a known problem after operations and may be
especially relevant in the elderly. The aim of this international multicentre
study was to investigate short- and long-term cognitive dysfunction in elderly
patients and to elucidate the relevance of hypoxaemia and hypotension as
causative factors. METHODS: 1218 patients aged 60 years and older and scheduled
for major non-cardiac surgery under general anaesthesia were investigated. Oxygen
saturation was measured by continuous pulse oximetry before surgery and
throughout the day of and the first 3 nights after surgery. Blood pressure was
recorded every 3 minutes during the operation and every 15-30 min for the rest of
that day and night. Cognitive testing was performed before and 1 week and 3
months after the operation. Cognitive dysfunction was identified with
neuropsychological tests compared with controls recruited from the UK (n = 176)
and the same countries as study centres (n = 145). RESULTS: Postoperative
cognitive dysfunction was present in 25.8% of patients 1 week after surgery and
in 9.9% 3 months after surgery, compared with 3.4% and 2.8%, respectively, of the
UK controls. Increasing age and duration of anaesthesia, little education, a
second operation, postoperative infections, and respiratory complications were
the risk factors for early postoperative cognitive dysfunction, but only age was
a risk factor for long-term postoperative cognitive dysfunction. Hypoxaemia and
hypotension were not significant risk factors at any time. CONCLUSION: With this
investigation long-term cognitive dysfunction could be proven definitively for
elderly patients after major operations under general anaesthesia. No factors
with prophylactic or therapeutic influence were detectable so that aetiology and
pathophysiology of POCD could not be further determined.
PMID- 10672353
TI - [Inadvertent potassium chloride infusion in an epidural catheter].
AB - In a 65 years old male patient 38 cc of a 7.45% potassium chloride-solution was
inadvertently infused within 3 hours into an epidural catheter on the first
postoperative day. The epidural potassium chloride administration resulted in a
paresis and painful paraesthesia of the patient's legs and a level of sensory
blockade to TH 11. Furthermore vegetative symptoms like hypertension and
tachycardia were observed. For therapy a single bolus of 40 mg dexamethasone was
administered intravenously followed by an epidural infusion of sodium chloride
0.9% 99 cc/h for several hours. About 6 hours after the start of infusion all
symptoms had disappeared. It is proposed that the use of colour-coded epidural
catheter devices and coloured electrolyte solutions as well as infusion-pumps
with a larger reservoir that reduce the frequency of syringe changes would be
helpful in avoiding such complications.
PMID- 10672354
TI - [Bilateral hydrothorax with hydromediastinum after accidental catheter
dislocation].
AB - We report a complication during the insertion time of a central venous catheter
in a patient with intracerebral bleeding. This complication was caused by an
inadvertent dislocation of a subclavian catheter. Hydromediastinum and bilateral
hydrothorax developed. There was a clear diagnosis followed by removal of the
central venous catheter after radiological investigations could explain the cause
of the complication and the clinical symptoms. In the course of events
mediastinitis was diagnosed. The clinical condition improved under antibiotic
therapy. The patient could be transferred to another clinical unit for
endovascular treatment of an arterio-venous cerebral malformation.
PMID- 10672355
TI - [Is the laryngeal mask a minimally invasive instrument for securing the airway?
Supplementary remarks on the paper "Injures and dangers in the use of the
laryngeal mask" by V. Hempel, Anaesthesist (1999)48:399-402].
AB - Minor laryngopharyngeal complaints following anaesthesia considerably determine
postoperative patient comfort. They cannot be eliminated but reduced by
experience and careful preparation and insertion technique. The incidence of
minor laryngopharyngeal symptoms following the use of the laryngeal mask airway
is similar to that following endotracheal intubation. However, there seems to be
a distinct pattern of complaints: discomfort with swallowing is more frequent
after LMA, whereas dysphonia is more often observed following endotracheal
intubation. The significance of LMA cuff pressures in the pathogenesis of
postoperative throat complaints remains unclear. There is sound evidence that
cuff pressure is not a representative measure for the effective pressure load
upon the pharyngeal mucosa. Measurement of cuff pressure is not obligatory,
instead reduction of cuff volume to a "just seal" situation seems to be a
reasonable approach. The laryngeal mask airway has definitely changed
anaesthesiology airway management. Whether this is due to its supposedly less
invasiveness compared to endotracheal intubation has not been proven by
scientific investigations.
PMID- 10672356
TI - [Cost control in the hospital. An introduction to cost and performance
management].
PMID- 10672357
TI - [Excitation following sevoflurane: a problem in pediatric anesthesia?].
PMID- 10672358
TI - [The history of the development of intensive care in Germany--contemporary
reflections. 12. The development of intravenous infusion techniques from personal
experience].
PMID- 10672359
TI - [The implementation of the International Classification of Diseases (ICD-10) in
Germany. Tools and information on the internet].
AB - ICD-10 is to be implemented for morbidity coding in Germany soon. The electronic
versions of ICD-10 are introduced. For everyday work with the classification and
for epidemiological research further tools are provided by DIMDI:ICD-10 meta
files, ICD conversion tables, ICD-10 thesaurus of diagnostic terms. All files are
available free of charge via the INTERNET.
PMID- 10672360
TI - [Perioperative hypothermia].
PMID- 10672361
TI - A comparative Golgi study of chicken (Gallus domesticus) and homing pigeon
(Columba livia) hippocampus.
AB - Neurons and fibres in the chick and homing pigeon hippocampus were described
following Golgi impregnation. Two principal classes of neurons were
distinguished: projection neurons with distant projecting axons and spiny
dendrites, and local circuit neurons. In the homing pigeon and chicken
hippocampus there are three types of projection neurons: pyramidal, pyramidal
like and multipolar. The pyramidal and pyramidal-like neurons are only found in
the central 'pyramidal' layer of the hippocampus whereas multipolar neurons are
present in the suprapyramidal, pyramidal and infrapyramidal layers. The axon of
projection neurons typically emits several varicose collaterals from the initial
section. Most of these collaterals extend along the infrapyramidal layer of the
hippocampus, while others ascend to the pyramidal and suprapyramidal layers where
they branch. The number of impregnated axon collaterals was higher in the homing
pigeon than in the chick hippocampus. A variety of multi-angular/ovoid local
circuit neurons ranging from small to large size are found in the homing pigeon
and chick hippocampus. Their axons develop local arborization of varicose
branches, the extent of which varies with the type of local circuit neurons. The
density of GABA immunopositive local circuit neurons was found to be greater in
the homing pigeon than in the chick. The profuse arborization of projection
neuron axon collaterals and the higher density of GABA-immunopositive local
circuit neurons in the homing pigeon hippocampus may underlie the differences in
hippocampal function between the homing pigeon and chick, and this complex local
connectivity may contribute to the ability of spatial orientation and memory.
PMID- 10672362
TI - Immunolocalization of the transcription factor Slug in the developing avian
heart.
AB - Slug is a transcription factor involved in processes such as the formation of
mesoderm and neural crest, two developmental events that imply a transition from
an epithelial to a mesenchymal phenotype. During late cardiac morphogenesis,
mesenchymal cells originate from two epithelia--epicardial mesothelium and
cushion endocardium. We aimed to check if Slug is expressed in these systems of
epithelial-mesenchymal transition. We have immuno-located the Slug protein in the
heart of quail embryos between Hamburger and Hamilton stages HH16 and HH30. In
the proepicardium (the epicardial primordium), Slug was detected in most cells,
mesothelial as well as mesenchymal. Slug immunoreactivity was strong in the
mesenchyme of the endocardial cushions and subepicardium from its inception until
HH24, but the immunoreactivity disappeared in later embryos. Only a small portion
of the endocardial cells located in the areas of epithelial-mesenchymal
transition (atrioventricular groove and outflow tract) were immuno-labelled,
mainly between HH16 and HH20. Endocardial cells from other cardiac segments were
always negative, except for a transient, weak immunoreactivity that coincided
with the development of the intertrabecular sinusoids of the ventricle. In
contrast, virtually all cells of the epicardial mesothelium were immunoreactive
until stage HH24. The mesenchymal cells that migrate to the heart through the
spina vestibuli were also conspicuously immunoreactive. The myocardium was not
labelled in the stages studied. Our results stress the involvement of Slug in the
epithelial to mesenchymal transition. We suggest that Slug can constitute a
reliable marker of the cardiac epithelial cells that are competent to transform
into mesenchyme as well as a transient marker of the epithelial-derived
mesenchymal cells in the developing heart.
PMID- 10672364
TI - The formation of the chick ileal muscle layers as revealed by alpha-smooth muscle
actin immunohistochemistry.
AB - The genesis of intestinal smooth muscle layers was immunohistochemically
investigated by use of an antibody to alpha-smooth muscle actin (alpha-SMA) in
the developing chick ileum. Myoblast cells positive for alpha-SMA were already
found in the presumptive circular muscle layer on E 8.5. On E 11.5 radially
oriented muscle fibers were protruded from the outermost layer of the developing
circular musculature and then formed a tuft-like aggregates. These radial muscle
bundles were bent into an L-shape. The long distal extension of muscle bundles
run parallel to the long axis of the ileal loop and developed into the
longitudinal muscle layer. The obliquely oriented muscle fibers, locating at the
intermuscular space of the muscularis propria, probably are to be considered a
remnant of the short extension of radial muscle bundles. The muscularis mucosae
was formed by the processes equivalent to the genesis of longitudinal muscle
layer. On E 14.5 centripetally oriented muscle fibers emerged from the innermost
layer of circular musculature. The long distal extension of centripetal fibers
lay along the inner surface of developing circular musculature. On E 19.5 the
longitudinal muscle layer of the muscularis mucosae was newly formed by
separating from the circular musculature. The villous myoblast cells initially
developed from the innermost layer of the muscularis mucosae on E 18.5, and were
widely distributed in the lamina propria mucosae on E 20.5. Temporal and
chronological pattern in expression of alpha-SMA was observed during the
development of the chick intestinal smooth muscle. By E 14.5 the entire layer of
the muscularis propria was intensely immunostained for alpha-SMA, but from E 15.5
onward the staining intensity gradually began to decrease from the outer half of
the circular musculature. Finally, the immunoreactivity was localized in the
inner layer of circular muscle and the longitudinal muscle layer. A possible
functional role of this inner layer of circular muscle is discussed.
PMID- 10672363
TI - "Rodent-like" and "primate-like" types of astroglial architecture in the adult
cerebral cortex of mammals: a comparative study.
AB - Previous observations disclosed that astroglia with interlaminar processes were
present in the cerebral cortex of adult New and Old World monkeys, but not in the
rat, and scarcely in the prosimian Microcebus murinus. The present report is a
more systematic and comprehensive comparative analysis of the occurrence of such
processes in the cerebral cortex of several mammalian species. Brain samples were
obtained from adult individuals from the following orders: Carnivora (canine),
Rodentia (rat and mouse), Marsupialia (Macropus eugenii), Artiodactyl (bovine and
ovine), Scandentia (Tupaia glis), Chiroptera (Cynopteris horsfieldii and C.
brachyotis), and Primate: Prosimian (Eulemur fulvus), non-human primate species
(Cebus apella, Saimiri boliviensis, Callithrix, Macaca mulatta, Papio hamadryas,
Macaca fascicularis, Cercopithecus campbelli and C. ascanius) and from a human
autopsy. Tissues were processed for immunocytochemistry using several antibodies
directed against glial fibrillary acidic protein (GFAP), with or without
additional procedures aimed at the retrieval of antigens and enhancement of their
immunocytochemical expression. The cerebral cortex of non-primate species had an
almost exclusive layout of stellate astrocytes, with only the occasional presence
of long GFAP-IR processes in the dog that barely crossed the extent of lamina I,
which in this species had comparatively increased thickness. Species of
Insectivora and Chiroptera showed presence of astrocytes with long processes
limited to the ventral basal cortex. Interlaminar GFAP-IR processes were absent
in Eulemur fulvus, at variance with their limited presence and large within- and
inter-individual variability as reported previously in Microcebus murinus. In New
World monkeys such processes were absent in Callithrix samples, at variance with
Cebus apella and Saimiri boliviensis. Overall, the expression of GFAP-IR
interlaminar processes followed a progressive pattern: bulk of non-primate
species (lack of interlaminar processes)--Chiroptera and Insectivora (processes
restricted to allocortex) < strepsirhini < haplorhini (platirrhini < catarrhini).
This trend is suggestive of the emergence of new evolutionary traits in the
organization of the cerebral cortex, namely, the emergence of GFAP-IR long,
interlaminar processes in the primate brain. Interlaminar processes may
participate in a spatially restricted astroglial role, as compared to the one
provided by the astroglial syncytium. It is proposed that the widely accepted
concept of an exclusively astroglial syncytium is probably linked with a specific
laboratory animal species ("rodent-type" or, rather, "general mammalian-type"
model) that misrepresents the astroglial architecture present in the cerebral
cortex of most anthropoid adult primates ("primate-type" model), including man.
PMID- 10672365
TI - Confocal microscopy of Tomes' granular layer in dog premolar teeth.
AB - Tomes' granular layer is the hypomineralized area of radicular dentin, but
knowledge concerning it is limited. The present study was designed to investigate
the structural characteristics of Tomes' granular layer in the dog's teeth by
confocal microscopy. Permanent premolars of four beagles, two at 7 months and the
other two at 14 months of age, were used for observation. During premolar root
formation, the 7-month-old dogs were injected with calcein and alizarin red S for
vital staining of dentin, and ground sections of the teeth were prepared. Both
ground and decalcified-paraffin sections were made from the teeth of the 14-month
old dogs and stained with basic fuchsin or with hematoxylin and eosin. All
sections were examined by fluorescence and confocal microscopy. In the ground
sections, granules of Tomes' layer and dentinal tubules were stained with basic
fuchsin and with calcein. The granules of Tomes' layer stained with calcein were
seen only near the labeling lines by calcein. The granules of Tomes' layer
appeared as bright spots in cross sections, and as lines in longitudinal
sections. When the sections were cut tangentially through the surface of dentin,
the granules of Tomes' layer showed a reticular structure. Most of the dentinal
tubules were seen to pass between the granules and terminated in the dentin
cementum junction. Looped tubules were not found in this area. In the paraffin
sections stained with hematoxylin and eosin, extracellular matrix of dentin
showed fluorescence of various intensities and dentinal tubules appeared dark. At
the surface of the radicular dentin, the granules of Tomes' layer appeared as
fluorescent fibers running parallel to the surface of dentin in the longitudinal
sections. The fibers appeared as bright spots in the cross sections and as a mesh
in the tangential sections. In the periodontal ligament, collagen fibers showed
intense fluorescence, whereas most cells were negative. From these results we
conclude that Tomes' granular layer of dog's teeth may be the collagen fiber
bundles that remained uncalcified or hypocalcified within the radicular dentin.
PMID- 10672366
TI - Development of full-length Trk B-immunoreactive structures in the prefrontal and
visual cortices of the macaque monkey.
AB - Distribution and morphological changes of cells containing the signal transducing
neurotrophin receptor, full-length Trk B (fl-Trk B), were investigated in the
prefrontal cortex (area FD) and the primary visual cortex (area OC) of the
macaque monkey between embryonic day 140 and the adult stage. In area FD at the
adult stage, fl-Trk B immunoreactivity was mainly observed in the pyramidal cells
in layers II/III, V and VI. Small numbers of granule cells in layer IV were
immunopositive. Bipolar and multipolar cells in layer II were rarely
immunoreactive. At embryonic day 140, the number of fl-Trk B immunoreactive
pyramidal cell was high, and gradually decreased until the adult stage. In layer
IV, the number of fl-Trk B-ir cells was also high at embryonic day 140, and
decreased remarkably from postnatal day 7 to the adult stage. On the other hand,
in area OC at the adult stage, cells in layers II/III, IV, V and VI were fl-Trk B
immunopositive. From embryonic day 140 until adulthood, the cells in layer IVc
were fl-Trk B immunoreactive. The strongest fl-Trk B immunoreactivity in areas FD
and OC occurred at postnatal month 6, coinciding with the time of the synapse
overproduction. These findings suggest that ligands of fl-Trk B, such as BDNF and
NT4/5 may be involved in the development and maintenance of the monkey cerebral
cortices.
PMID- 10672367
TI - Screening for surreptitious laxative abuse.
PMID- 10672368
TI - Clinical governance.
PMID- 10672369
TI - Principles, practice and paracetamol: when units matter.
PMID- 10672370
TI - Pitfalls in forensic toxicology.
PMID- 10672371
TI - Standardization of HbA1c measurements: a consensus statement.
PMID- 10672372
TI - The clinical need for HbA1c standardization.
PMID- 10672373
TI - Adult reference ranges for serum cystatin C, creatinine and predicted creatinine
clearance.
AB - Serum cystatin C measurement has been previously shown by ourselves and others to
be a better indicator of changes in glomerular filtration rate (GFR) than serum
creatinine. However, the available literature on reference values for cystatin C
concentration remains surprisingly sparse; we thus set out to determine an adult
reference range. Blood was taken from 309 healthy blood donors and creatinine and
cystatin C concentrations were measured using commercially available automated
methodologies. In addition, predicted creatinine clearances were calculated using
the Cockcroft and Gault formula. The 95% reference intervals for creatinine,
predicted creatinine clearance and cystatin C for all blood donors, regardless of
gender, were 68-118 mumol/L, 58-120 ml/min/1.73 m2 and 0.51-0.98 mg/L,
respectively. For women, the intervals were 68-98 mumol/L, 60-119 ml/min/1.73 m2
and 0.49-0.94 mg/L; for men, they were 78-123 mumol/L, 57-122 ml/min/1.73 m2 and
0.56-0.98 mg/L. This mean 95% reference interval for cystatin C in all donors
under 50 years of age was 0.53-0.92 mg/L; for those over 50 years of age it was
0.58-1.02 mg/L. The small difference between make and female ranges meant that a
single reference range for cystatin C could be established for all adults under
50 years of age without adjustment for body surface area. Serum cystatin C
measurement offers a simpler and more sensitive screening test than serum
creatinine for early changes in GFR.
PMID- 10672374
TI - Glomerular filtration rate by single-injection inulin clearance: definition of a
workable protocol for children.
AB - The total serum clearance of inulin after a single intravenous injection is an
established method for the determination of the glomerular filtration rate (GFR).
To optimize this procedure in children, we analyzed 117 serum inulin time-decay
curves in 59 children (age range 1.3-15.2 years)with renal disease. It was found
that the two-compartment model fitted statistically better to the disappearance
curves of serum inulin than the one-compartment model. The sampling frequency
could be reduced from 12 to a minimum of seven data points (t=0, 10, 20, 30, 65,
120 and 240 min) in 4 h without a relevant change in the fit of the two
compartment model to the date or in the calculated clearance of serum inulin. We
conclude that, by using a standardized 'seven-sample schedule', followed by a two
compartment analysis, the single-injection serum clearance of inulin is a
suitable compromise between practical convenience and clinical accuracy for the
determination of the GFR in children.
PMID- 10672375
TI - Enzyme inhibitory antibody to pyruvate dehydrogenase: diagnostic utility in
primary biliary cirrhosis.
AB - In primary biliary cirrhosis, autoantibodies are produced to the family of 2
oxoacid dehydrogenase complexes. These 'anti-mitochondrial' antibodies are
traditionally detected by immunofluorescence but this method of detection is
subjective and labour-intensive. We assessed an enzymatic mitochondrial antibody
(EMA) assay based on antibody inhibition of enzymatic activity of pyruvate
dehydrogenase complex in wells of microtitre plates with a colorimetric read-out.
We tested 48 Australian and 1947 Japanese patients with primary biliary
cirrhosis, 306 normal subjects and 691 patients with various hepatic and non
hepatic diseases. The overall sensitivity of the EMA for the diagnosis of primary
biliary cirrhosis, 82%, was slightly lower than that of immunofluorescence, 90%
The advantages of the EMA test include high specificity, >99%, and semi-automated
features facilitating objectivity, rapidity, simplicity and economy. The EMA test
could be particularly applicable to population screening for early primary
biliary cirrhosis.
PMID- 10672376
TI - Quantification of urinary oxalate with a chloride- and nitrate-insensitive
oxalate oxidase.
PMID- 10672377
TI - Hypertonic versus isotonic salt bridges and the measurement of ionized calcium.
PMID- 10672378
TI - Calculation of renal tubular reabsorption of phosphate: the algorithm performs
better than the nomogram.
PMID- 10672379
TI - Enzymatic assay for magnesium in serum.
PMID- 10672380
TI - Diagnostic dilemmas in Cushing's syndrome.
PMID- 10672381
TI - Traumatic chylous ascites.
PMID- 10672382
TI - A case of factitious hypercalcaemia.
PMID- 10672383
TI - Glycation rates in type 1 diabetes mellitus.
PMID- 10672384
TI - Creatinine clearance and glomerular filtration rate.
PMID- 10672385
TI - A pilot study of the efficacy and tolerability of intralesional recombinant human
beta-interferons in cervical intraepithelial neoplasia.
AB - Beta-interferons possess anti-viral, cell proliferation inhibition and
immunomodulatory characteristics which may be of use in the treatment of cervical
intraepithelial neoplasia (CIN). Intralesional administration may avoid systemic
side effects. Twenty-six women with cervical punch biopsy proven CIN I and II
were treated by interferon injection into the cervical transformation zone
according to three dosage regimens--6 million international units (IU) weekly for
six weeks, 9 million IU weekly for six weeks and 12 million IU bi-weekly for
three weeks. At the last treatment visit, cervical cytology and biopsy were taken
to ensure no disease progression and large loop excision of the transformation
zone (LLETZ) was carried out six months after treatment. Therapy was well
tolerated with 93% of the scheduled 156 treatments given. Side effects which
caused cessation of treatment included severe myalgia, headaches and prolonged
flu-like symptoms. The 2 patients who failed to attend for LLETZ at six months
and another 2 patients who received fewer than five scheduled treatments were
excluded from analysis. LLETZ histology was negative in 12 patients (54%), showed
inflammatory changes or squamous metaplasia in 4 (18%), was unchanged in 4
patients and had progressed in 2 (10%). Whilst intralesional beta-interferon
clearly has activity in CIN, the response rate is less than that seen for
excisional or ablative procedures. Nevertheless, it may have a role in the
management of CIN where, for medical reasons of patient preference, there is a
desire to avoid surgical therapy.
PMID- 10672386
TI - The effect of fenofibrate on insulin sensitivity and plasma lipid profile in non
diabetic males with low high density lipoprotein/dyslipidaemic syndrome.
AB - Non-diabetic males, particularly those with very low levels of high density
lipoprotein (HDL) type cholesterol and high levels of very low density type
lipoprotein (VLDL), are associated with insulin resistance and decreased insulin
sensitivity. The evidence that elevation of HDL cholesterol and diminution of
triglycerides with drugs, with improvement in insulin sensitivity is still
lacking. In the treatment of the dyslipidaemic syndromes with hypolipidaemic
drugs, the associated metabolic abnormality of insulin resistance/sensitivity has
to be addressed. We investigated the degree of decreased insulin sensitivity in
23 patients with low HDL and/or raised triglycerides by measuring the fasting,
first and second hour insulin levels during an oral glucose tolerance test (OGTT)
and repeated the measurements after a 6-month course of fenofibrate. The insulin
levels were correlated with the OGTT, blood pressure, total cholesterol, HDL
cholesterol, LDL cholesterol, and triglycerides measured before and at the end of
the trial. The serum insulin at the second hour of the OGTT fell from 100.79 +/-
42.79 mU/l to 54.56 +/- 25.43 mU/l (P < 0.0005) even though there was no change
in the blood glucose level at this point. Our study shows that fenofibrate
(Lipanthyl) 300 mg daily significantly raises the pretreatment low HDL
cholesterol (from 0.64 +/- 0.1 mmol/l to 0.99 +/- 0.2 mmol/l) as well as lowers
the triglyceride level (from 2.17 +/- 1.1 mmol/l to 1.43 +/- 0.64 mmol/l) in
patients with low HDL/dyslipidaemic syndrome. The data also support the
conclusion that treatment with fenofibrate increases insulin sensitivity as
measured by the corresponding insulin levels of the OGTT in the study subjects
who presented with very low HDL cholesterol level. There was also a decrease in
blood pressure readings in our study subjects. Throughout the trial, there was no
significant change in body weight or exercise level in the subjects studied.
PMID- 10672388
TI - Excimer laser phototherapeutic keratectomy for recurrent corneal erosions.
AB - The purpose of this paper was to review the Singapore National Eye Centre's
(SNEC) experience with excimer laser phototherapeutic keratectomy (PTK) for
treating recurrent corneal erosions (RCE). Thirty-five eyes of 32 patients who
had PTK between 1992 and 1997 in SNEC were studied retrospectively. There was a
history of previous ocular trauma in 15 eyes. Sixteen eyes had anterior corneal
dystrophy. All had received conventional therapy without improvement in symptoms.
The mean duration of symptoms prior to PTK was 19 months (range 1 to 71 months).
PTK was performed with one of two 193 nm excimer lasers (Summit UV200LA, Summit
Technology, Waltham, USA or Visx 20/20B, Visx Corp, Santa Clara, USA). An average
of 30 laser pulses were delivered to Bowman's membrane after debridement of the
corneal epithelium. The mean follow-up time was 12 months (range 0 to 56 months).
Among those with adequate length of follow-up, 26/27 eyes (96%) were symptom-free
for 3 months, 19/22 eyes (86%) were symptom-free for 6 months and 9/13 eyes (69%)
were symptom-free for 1 year. Three eyes had repeat PTK. Mild corneal haze was
seen in 3 eyes. No visually threatening complications were encountered. PTK is a
safe and effective procedure for RCE refractory to conventional treatment.
PMID- 10672387
TI - Use of EMLA cream or alfentanil for analgesia during ophthalmic nerve blocks.
AB - This prospective double-blind study compared the effectiveness of EMLA with
alfentanil and placebo in reducing the overall pain during ophthalmic nerve
blocks. Seventy-five patients scheduled for cataract surgery were divided into
three groups. Patients in the EMLA group had EMLA cream applied over skin areas
corresponding to injection sites for retrobulbar and facial nerve blocks one hour
before the nerve blocks, and placebo intravenous normal-saline injection 2
minutes before the first nerve block. The alfentanil group had placebo cream
applied and intravenous alfentanil 10 micrograms.kg-1 while patients in the
placebo group received placebo cream and intravenous normal-saline at similar
time intervals prior to the nerve blocks. Patients then received facial nerve
blocks and retrobulbar block by the same surgeon. Pain scores by patients and
independent observers were significantly lower in the EMLA and alfentanil groups
compared to placebo (P < 0.005) with no significant difference between the EMLA
and alfentanil groups.
PMID- 10672389
TI - Transscaphoid perilunate fracture/dislocations--results of surgical treatment.
AB - Sixteen cases of dorsal transscaphoid perilunate fracture/dislocations in 15
patients were treated by open reduction and internal fixation of the scaphoid
with a Herbert screw and/or Kirschner wires. All patients were male, with a mean
age of 31 years. The average follow-up period was 3 years. These perilunate
dislocations were transscaphoid in 13 cases, and transstyloid and transscaphoid
in 3 cases. There was one case of median nerve deficit preoperatively. Open
reduction was performed through a volar approach in all cases. Herbert screw
fixation of the scaphoid was performed on 13 cases, of which supplemental
Kirschner wires were used in 2 cases. Three cases had fixation with Kirschner
wires only. There were 2 cases of non-union which required bone grafting on
follow-up. A clinical evaluation scoring system assessing pain, occupational
ability, range of motion and grip strength was used. Based on this, there were 10
excellent to good (62.5%) and 6 fair results. For the majority of our patients,
surgical outcome is characterised by acceptable relief of pain, functional motion
and grip strength.
PMID- 10672390
TI - Perinatal drug abuse in KK Women's and Children's Hospital.
AB - No local figures are available in Singapore on the incidence of perinatal drug
abuse and its effect on the foetus and the neonate. The objectives of this study
were to determine the incidence of perinatal drug abuse and neonatal abstinence
syndrome; to identify a maternal profile at high risk for substance abuse and to
document the presenting features and treatment of infants with neonatal
abstinence syndrome. Out of 14,690 births during the period January 1994 to
December 1996, 38 (0.25%) had evidence of perinatal drug abuse. The study
revealed that a high-risk maternal profile for drug abuse comprised of single
mothers (52%); history of smoking (52%); no antenatal care (37%) and belonging to
the Malay ethnic group (82%); and younger maternal age. Self-reporting was
uncommon, occurring only in 8% and in 40% of cases, there was no known history of
maternal drug addiction. The drug abused in all cases was heroin. Human
immunodeficiency virus (HIV) screening was done only in a minority (21%) of the
mothers and it was negative in all. Eighteen (47%) infants had evidence of
neonatal abstinence syndrome with neurological manifestations being the
commonest. Urine toxicology screening was positive in 26% of cases and had only
70% sensitivity and 41% positive predictive value. On follow up, default rate was
high with 42% babies not attending follow up at the outpatient clinic. In
conclusion, there is a need to maintain a high index of suspicion of substance
abuse in those with high-risk maternal profile and their neonates should be
closely watched for features of neonatal abstinence syndrome. Alternative methods
of toxicology screening apart from urine need to be evaluated in order to improve
the drug detection rate.
PMID- 10672391
TI - Is staging of benign prostatic hyperplasia (BPH) feasible?
AB - With better understanding of the natural history of benign prostatic hyperplasia
(BPH), the treatment can be tailored to the severity of the disease. The aims of
this study were to determine the feasibility of staging BPH according to its
severity and choose the optimal therapeutic tool for each category, and for
comparing results of various modalities of treatment. Two hundred and twenty-five
patients with clinical BPH were seen between October 1994 and July 1995. Initial
assessment included the International Prostatic Symptom Score, and the quality of
life index, digital rectal examination, urinalysis, prostate specific antigen,
uroflow and residual urine estimation. Patients were then divided into: Stage 1,
those with no bothersome symptoms and no significant obstruction, they can
generally be watched. Stage 2, those with bothersome symptoms but without
significant obstruction, they can be treated with pharmacotherapy/thermotherapy.
Stage 3, those with significant obstruction defined as uroflow of less than 10
ml/s with persistent residual urine of > 100 ml, transurethral prostatic
resection (TURP) would be recommended. Stage 4, those with complications of BPH
such as chronic retention of urine and bladder stone, they would need TURP. One
hundred and fifty-nine patients had complete follow up data of at least 2 years.
Of the 70 patients who were originally in Stage 1, 59 (89%) remained in status
quo, 6 patients developed acute retention of urine and only 1 required TURP. Of
the 38 patients in Stage 2, 24 were down-staged to Stage 1 after medication and
thermotherapy but 4 still remained in Stage 2 and the other 10 had worsening of
symptoms requiring surgery. Of the 46 patients in Stage 3, 30 (65%) had TURP and
all except 1 were down-staged to Stage 1. All patients in Stage 4 had TURP and
improved. We conclude that staging of patients with clinical BPH is feasible. It
serves as a useful guide for management and improves cost effectiveness.
PMID- 10672392
TI - Focused abdominal sonography for trauma (FAST).
AB - This study aims to examine the feasibility of applying the focused ultrasound
examination (FAST) in the initial assessment of the trauma patient. Its advantage
over diagnostic peritoneal lavage lies in the speed in which it can be performed,
its non-invasiveness and repeatability. Over the period January 1997 to July
1998, the FAST examination (Acuson 128XP/10, 3.5 MHz probe) was used to assess
the presence of haemopericardium or haemoperitoneum in 38 multi-trauma patients
admitted to the Singapore General Hospital. The sample comprises mainly males
(82%) with a mean age of 34 years (range 17 to 77 years). The mechanism of injury
was predominantly blunt (95%). Mean Injury Severity Score (ISS) was 22. Eleven
patients presented in shock and 16 patients had abdominal tenderness on
examination. A single surgeon did the examination, which was performed during the
secondary survey phase of resuscitation. Time taken for the FAST examination
averaged 2.3 +/- 1.3 minutes. The results of the examination were compared to
diagnostic peritoneal lavage, CT scan, operative findings, serial examination
and/or post-mortem findings. Overall sensitivity was 67% and specificity 97%.
Although the FAST examination missed the small amount of free fluid seen in the
CT scan of 2 patients, these patients did not have to undergo laparotomy as their
abdominal examination was normal. We conclude that the FAST examination is
feasible and should be part of a general surgeon's armamentarium in the initial
assessment of trauma.
PMID- 10672393
TI - Outcome of tunnelled central venous haemodialysis catheters inserted by
radiologists.
AB - Radiologists have only recently been involved in the percutaneous placement of
tunnelled central venous haemodialysis catheters. We report our initial
experience with our first 60 catheters. All catheters were successfully inserted.
Immediate complications encountered included puncture site haemorrhage in 3
patients (5%) and puncture of the left brachiocephalic vein in 1 patient (1.7%).
These were managed conservatively without any clinical sequelae. About 80% of the
catheters were uncomplicated and removed electively. Slightly more than 80% of
the catheters were in place for more than 30 days. Infection and blocked
catheters were the most common short-term complications. Ten catheters (17%) were
infected resulting in premature removal of 9. There was 1 death from presumed
line sepsis. Mean duration before the onset of infection was 53 days; the rate of
infection was 0.28 episodes per 100 catheter days. Five catheters (8%) were
blocked or had poor flow. The mean duration before the onset of blockage was 39
days and the rate of blockage was 0.14 episodes per 100 catheter days. A higher
proportion of catheters inserted from the left encountered complications. In
conclusion, percutaneous insertion of tunnelled haemodialysis catheters by
radiologists is safe and effective. The right internal jugular vein should be the
preferred access site. Precautions should be taken to avoid infectious
complications given the high rate of catheter removal amongst infected catheters.
PMID- 10672394
TI - Video-assisted thoracoscopy: role in the management of intrathoracic pathology.
AB - A retrospective study was done from October 1992 to December 1996 of 48 patients
who underwent video-assisted thoracoscopy. A male to female ratio of 3.7:1 was
seen, with a mean age of 50 +/- 19 years. The underlying diagnoses included
spontaneous pneumothorax (n = 23), malignant pleural effusion (n = 16), lung
disease (n = 4), trauma (n = 2), empyema (n = 2) and oesophageal carcinoma (n =
1). The use of this modality is discussed in the treatment of various
intrathoracic pathologies.
PMID- 10672395
TI - An in vitro evaluation of epidural catheters: tensile strength and resistance to
kinking.
AB - The tensile strengths of 12 commercially available brands of epidural catheters
were assessed using an Instron material testing device. The mean values of the
tensile strengths ranged from 1.89 to 3.74 kilogram force. The extent of catheter
occlusion due to kinking was also studied using an in vitro apparatus designed to
simulate drug delivery at various degrees of flow restriction. It was determined
that reinforced catheters were less likely to be occluded secondary to kinking.
PMID- 10672396
TI - Repigmentation of vitiligo with autologous blister-induced epidermal grafts.
AB - Treatment of vitiligo can sometimes be difficult and disappointing. PUVA
treatments give fairly good results. However, acral regions like the hands or
feet or areas over bony prominences like the elbow, are resistant to PUVA.
Blister-induced epidermal grafts have been used to repigment vitiligo skin. This
study was carried out on patients with vitiligo areas unresponsive to either PUVA
treatments or who had segmental vitiligo. PUVA treatments were resumed after skin
grafting. Twenty-five patients with stable vitiligo were grafted with blister
induced epidermal grafts. Up to 70% of the whole vitiligo areas were grafted in
one sitting. A total of 105 grafts were done. In 9 grafts, no repigmentation was
seen. The remaining 96 grafts resulted in pigmentation. Twelve had partial and 84
had complete repigmentation. No Koebner phenomenon was noted in both the
recipient sites or the donor sites. Blister-induced epidermal graft is an
effective alternative to repigment stable vitiligo areas. It is easy to do and
results are good. In this study, 96 out of 105 (91%) grafts had repigmentation.
PMID- 10672397
TI - One-year review of pityriasis rosea at the National Skin Centre, Singapore.
AB - Pityriasis rosea is a common, acute, self-limited papulosquamous eruption of
possible viral aetiology. The aim of this study was to describe the profile of
pityriasis rosea seen at a referral skin centre in Singapore. A retrospective
chart review was conducted of all the patients with a diagnosis of pityriasis
rosea seen during 1996. There were 368 patients; their ages ranged from 9 months
to 82 years with a peak in the 20 to 29 years age group. There were slightly more
males (1.2:1). The clinic incidence was 6.5 per 1000 cases. No ethnic
predilection was noted and cases were seen evenly throughout the year. About a
quarter of the patients gave a history of a viral infection shortly before or
during the occurrence of the rash. Most cases had a typical truncal distribution.
The herald patch was observed in 63 patients (17%). Inverse distribution
involving mainly the extremities were seen in 22 cases (6%) and eczematised
lesions were noted in 20 cases (5.4%). The two main differential diagnoses
considered were tinea infection and secondary syphilis. A fungal scrape and a
rapid plasma reagin test were done in 58 and 59 patients, respectively, and the
results were negative. Treatment was symptomatic and consisted of topical
steroids and antihistamines. Thirty patients (8%) were given oral prednisolone
for extensive eruptions. The pattern of pityriasis rosea in Singapore is similar
to that reported in other countries except for a male predominance and absence of
monthly variation. A lower incidence and an older group of patients were also
seen in our series as compared to African patients.
PMID- 10672398
TI - Intracoronary brachytherapy: the beginning of the end of restenosis?
AB - Restenosis remains a major problem 20 years after the introduction of coronary
angioplasty. Pharmacological therapy has generally been disappointing in reducing
the incidence of neointimal hyperplasia. Intracoronary brachytherapy is the
latest anti proliferative agent that is showing promise in the fight against
restenosis. Radiation therapy has been used for decades in the treatment of
benign proliferative disorders. Animal studies have consistently demonstrated the
efficacy of radiation therapy in inhibiting neointimal hyperplasia. Clinical
trials, using different radioactive isotopes and radiation sources, are now
showing dramatic reduction in neointimal hyperplasia and restenosis rates
following balloon angioplasty and stenting. Intracoronary brachytherapy is
beginning to show promise as one of the truly effective agent against neointimal
hyperplasia and restenosis.
PMID- 10672399
TI - Somatisation among Asian refugees and immigrants as a culturally-shaped illness
behaviour.
AB - Epidemiological studies indicate a high prevalence of major depression and
anxiety disorder (including post-traumatic stress disorder) among Asian refugees
and immigrants living in North America. Yet there exists an alarming
underutilization of mental health services and underdiagnosis of psychiatric
illness in this rapidly growing minority group. In order to investigate a
culturally-derived basis for these observations, a critical review was conducted
on descriptive epidemiologic, sociologic, and anthropologic studies of
psychiatric illness among Asians and Asian refugees and immigrants reported in
the general psychiatric and trans-cultural psychiatric literature of the past
forty years. Studies examining the mode of illness presentation among Asian
refugees seeking medical care suggest a marked tendency to articulate somatic
rather than affective complaints when serious underlying psychiatric conditions
exist. In this context, somatisation among Asian refugees and immigrants may
reflect culturally-shaped beliefs regarding notions of disease aetiology and
treatment as well as what is deemed culturally-appropriate help-seeking behaviour
during illness. Misdiagnosis and underdiagnosis of psychiatric illness in this
and other minority populations can be minimised by establishing pluralistic norms
and multidimensional criteria which take into account the ethnically diverse
manifestations of illness behaviour encountered increasingly in Western primary
care and psychiatry clinics.
PMID- 10672400
TI - Atypical mycobacterium infection with sporotrichoid spread in a patient with
human immunodeficiency virus.
AB - A case of Mycobacterium marinum infection presenting with a sporotrichoid spread
in a HIV positive Chinese male is presented. The patient responded to oral
cotrimoxazole treatment. A brief review of the literature concerning atypical
mycobacterial infection presenting in such a fashion is discussed.
PMID- 10672402
TI - Bullous dermatomyositis associated with nasopharyngeal carcinoma--a case report.
AB - Cutaneous manifestations of dermatomyositis commonly include Gottron's papules,
heliotrope rash, photosensitivity, poikiloderma and nailfold telangiectasia.
Vesicles and bulla are rare. We report a patient with dermatomyositis who
presented with blisters and oral ulcers. It is important to recognise this
bullous variant in order to avoid a delay in diagnosis. Bullous dermatomyositis
may also portend a poorer prognosis. Our patient was subsequently diagnosed to
have undifferentiated nasopharyngeal carcinoma.
PMID- 10672401
TI - Case reports of linear IgA bullous dermatosis of childhood.
AB - Linear IgA bullous dermatosis of childhood (LADC) is an uncommon acquired
blistering skin disorder which affects young children. It is characterised by a
linear band of IgA at the epidermal basement membrane on direct
immunofluorescence. From 1984 to 1988 at the previous skin centre at Middle Road
Hospital, and 1989 to 1997 at the present National Skin Centre, a total of 4
cases were seen. All the patients were female and their ages ranged from 5 to 14
years (mean 8 years). There were 2 Chinese, 1 Caucasian and 1 Malay. All
presented with an acute onset of blistering of 1 to 3 weeks' duration. Their skin
biopsies showed subepidermal bullae with neutrophils, with/without eosinophils
and direct immunofluorescence tests revealed linear deposits of IgA along the
dermoepidermal junction. All were treated with prednisolone and dapsone with good
results. One patient developed dapsone-induced haemolysis and treatment was
changed to colchicine. We review the epidemiology, aetiology, current concepts
and treatment modalities of this condition.
PMID- 10672403
TI - Chryseobacterium meningosepticum (Flavobacterium meningosepticum)--a report of
five cases in a local hospital.
AB - Chrysobacterium meningosepticum (Flavobacterium meningosepticum) is a known cause
of meningitis in premature and newborn infants. Infection due to this organism in
adults is uncommon. We report 5 cases of Chrysobacterium meningosepticum in adult
patients. Most of these patients were elderly and had underlying co-morbidities.
PMID- 10672404
TI - Chronic subdural haematoma presenting with transient ischaemic attacks--a case
report.
AB - We report a middle-aged man who presented with repeated episodes of transient
ischaemic attacks (TIA) in the setting of a chronic subdural haematoma. This case
report discusses the various pathophysiologic mechanisms whereby such TIA may
occur in chronic subdural haematoma. We also highlight the importance of cranial
imaging in cases of TIA.
PMID- 10672405
TI - Haemorrhage into non-functioning adrenal cysts--report of two cases and review of
the literature.
AB - Adrenal cysts are a rare condition and are usually non-functioning and
asymptomatic. Most of the reported cases were incidental findings or discovered
at autopsy. However, large cysts have a tendency to develop complications such as
intracystic haemorrhage and rupture, which can present as an acute surgical
emergency. We report two cases of adrenal cysts with intracystic haemorrhage. One
patient presented with persistent non-specific upper abdominal pain,
investigations with ultrasound (US) scan and computed tomographic (CT) scan
revealed a left adrenal cyst and gallstones. Simultaneous cholecystectomy and
adrenalectomy was performed with resultant relief of symptoms. The second patient
presented with acute abdominal pain simulating acute surgical abdomen.
Preoperative CT scan showed a large cystic lesion in the region of the tail of
the pancreas with radiological evidence of haemorrhage but was unable to confirm
its origin. The cyst was found to have arisen from the left adrenal gland at
laparotomy; left adrenalectomy with complete excision of the cyst was done.
Histology showed pseudocyst with haemorrhage in both cases. Pseudocyst is the
commonest histological type encountered clinically. We believe the second case is
related to pregnancy and childbirth as the patient presented during puerperium
and the cyst, even though very large in size (25 x 15 x 15 cm), was not noted
during antenatal screening with US scan.
PMID- 10672406
TI - A case report of adult T-cell leukaemia/lymphoma (ATLL).
AB - Adult T-cell leukaemia/lymphoma (ATLL) is a unique disease with distinct
manifestations, a characteristic phenotype and a likely retroviral aetiology. It
is unusual in Southeast Asia, though more commonly seen in some countries like
Japan. We report a case of this disease in a 71-year-old man in Singapore who
presented with papular erythematous eruptions for 6 years and subsequently
developed generalised lymphadenopathy. He was diagnosed to have ATLL and, despite
an initial response, became resistant to combination chemotherapy. We discuss the
aetiology, characteristics and management of this interesting disease.
PMID- 10672407
TI - Incessant ectopic atrial tachycardia and tachycardia-related cardiomyopathy:
therapeutic options and potential for cure.
AB - Incessant ectopic atrial tachycardia (IEAT) is a rare cause of cardiomyopathy.
Cardiomyopathy is reversible by curative ablation using surgery or radiofrequency
current. We report our experience with 5 patients with IEAT. Three patients
presented with palpitations and were diagnosed to have paroxysmal
supraventricular tachycardia (2 patients) and atrial flutter with 1:1 conduction
(1 patient), but 2 presented insidiously with congestive cardiac failure. All the
initial echocardiograms showed left ventricular dysfunction. The patients
underwent electrophysiological studies which confirmed the diagnosis of IEAT. The
first patient had surgical cryoablation and the other patients had successful
radiofrequency catheter ablation. Follow-up for 2 to 7 years has shown no
recurrences. All patients had significant improvement in left ventricular
function on echocardiography. In conclusion, curative ablation by surgery or
radiofrequency current is safe and effective. Because of its low morbidity,
radiofrequency catheter ablation should be the treatment of choice for IEAT,
especially if complicated by tachycardia-related cardiomyopathy.
PMID- 10672408
TI - Reconstruction of a supinated hypoplastic thumb with combined Huber transfer and
derotation osteotomy: a case report.
AB - The use of the abductor digiti minimi transfer to restore opposition in patients
with hypoplasia of the thumb has been widely described in the literature. It has
been found to be effective in restoring abduction, but less so in restoring the
rotational component of opposition. In cases where there is concomitant
supination of the thumb, abductor digiti minimi transfer alone would not result
in a good pinch as the thumb pulp is rotated away from the opposing finger. We
present a case of a 6-year-old girl with a hypoplastic supinated left thumb which
resembled a digit. There was also hypoplasia of the index finger. The hand had
poor function as a result of lack of opposition of the thumb. The thumb function
was restored by combining a derotational osteotomy (80 degrees) with the abductor
digiti minimi transfer originally described by Huber. Patient was able to hold
small object using key pinch and she could pinch with opposition of the thumb
pulp to the middle, ring and little finger pulps when reviewed 2 years post
surgery.
PMID- 10672409
TI - Osteoid osteoma after a stress fracture of the tibia: a case report.
AB - A 24-year-old man presented with a stress fracture over his left tibia following
an infantry training 6 years ago. X-rays of his left tibia revealed a stress
fracture and bone scan showed marked tracer uptake at the fracture. He was
treated conservatively but his pain persisted since then. Five years later, X
rays and histological examination confirmed the diagnosis of osteoid osteoma. The
stress fracture may act as a trigger for the formation of osteoid osteoma and
caused a delay in diagnosis.
PMID- 10672410
TI - Multivariate statistical analysis: a brief introduction.
PMID- 10672411
TI - 9th Seah Cheng Siang Memorial Lecture: gastric cancer--where are we now?
AB - Gastric cancer, the second most common cancer in the world, kills about one
million people a year, almost half of whom are Chinese. Chinese, Japanese and
Koreans as well as east Europeans top the list with over 40 per 100,000
population per year, with a wide margin over Americans, Indians and Zimbabweans
in whom the rates are below 1 per 100,000. The excellent prognosis of early
gastric cancer is well established, and survival of cancer involving beyond the
submucosa remains poor and there is little new in management. However, recent
years have witnessed a breakthrough in the understanding of causative factors and
molecular genetic abnormalities in gastric cancer that should pave the way for
prevention, early detection and prognostication. Established carcinogens for
gastric cancer now include Helicobacter pylori and N-nitroso compounds; other
causative factors include salt and salted food intake, cigarette smoking, male
sex, and familial genetic abnormalities. H. pylori infection increases cancer
risk by about 5 in a 10-year period. Diet high in salt carries a relative risk of
up to 6, and a highly significant correlation between 24 h urinary salt content
and incidence of gastric cancer has been shown in 24 countries. The risk from
smoking and male sex is under 2. Many N-nitroso compounds, which come from
nitrites, which in turn come from nitrates in food following bacterial
transformation in a hypochlorhydric environment, are established carcinogens in
animals, but their risk for human gastric cancer is still debatable. The
intestinal type of gastric cancer, according to Correa's hypothesis, develops
from chronic inflammation leading to intestinal metaplasia, dysplasia and cancer,
and is more associated with H. pylori and early gastric cancer. The diffuse type
of gastric cancer does not go through these precancerous conditions and moves
straight from inflammation to cancer. Associated with inflammation are an
increase in proliferation and apoptosis, and this fine balance between
proliferation and apoptosis may be uncoupled by genetic mutations. It is believed
that as a result of the accumulation of molecular genetic abnormalities, a cancer
eventually develops and metastasizes. p53 mutation, cyclin overexpression
(especially in intestinal type), microsatellite instability, down regulation of E
cadherin (especially in diffuse type), and telomerase reactivation are some
prominent examples. These molecular abnormalities have the potential for
screening, early detection and prognostication. Fruits and vegetables, green tea,
alpha-tocopherol and other micronutrients such as selenium have been shown to
reduce the risk for gastric cancer. In fact, it has been reported that diet
consisting of vegetables and fruits, low in salt, together with the avoidance of
cigarette smoking would prevent two-thirds to three-quarters of gastric cancer.
Furthermore, eradication of H. pylori, and for that matter future vaccination,
has the theoretical potential of preventing gastric cancer, and the potential use
of COX2 inhibiting NSAID in inducing apoptosis may reverse precancerous
conditions of the stomach. Both approaches are being intensely studied.
PMID- 10672412
TI - Early 21st century professional practice: change and challenge.
PMID- 10672413
TI - Current continuing medical education provision in Singapore.
PMID- 10672414
TI - Dimerization kinetics of violamycin BI anthracycline--the influence of ionic
strength.
AB - Violamycin BI is an anthracycline derivative with two sugars hanging on, each of
them carries one positive charge. It dimerizes under conditions, which depend on
the concentration of the antibiotic, pH and the ionic strength of the solution.
By keeping a constant pH in a phosphate-EDTA buffer, the rate constants of
violamycin BI dimerization were determined at various ionic strengths by
temperature jump method. The dimerization constant Kd, resulting from the ratio
of these rate constants, confirmed the values obtained spectrophotometrically in
this study or elsewhere. The influence of ionic strength (0.02-0.2 M) on the rate
constant values suggested to us some speculations on the reaction mechanism of
the dimerization, in which, the specific mutual orientation of the monomers in
the encounter, and perhaps a specific conformation of their side groups is
required before a stabilizing action of the binding forces sets in.
PMID- 10672415
TI - Pathways involved in trifluoperazine-, dibucaine- and praziquantel-induced
hemolysis.
AB - This work elucidates differences in the hemolytic pathway developed by the
antipsychotic trifluoperazine (TFP), the local anesthetic dibucaine (DBC) and the
antihelminthic praziquantel (PZQ). Their partition coefficients (P) were measured
at pH 7.4 between n-octanol, microsomes, liposomes, erythrocyte ghosts and n
octanol/water. The effective drug:lipid molar ratios for the onset of membrane
solubilization (ReSAT) and complete hemolysis (ReSOL) were calculated from the
experimental P values and compared with a classical surface-active compound
treatment Lichtenberg, D. Biochim. Biophys. Acta 821 (1985) 470-478[. The
contribution of charged/uncharged forms of TFP and DBC for the hemolytic activity
was also analyzed. In all cases the hemolytic phenomena could be related to the
monomeric drug insertion into the membrane. Only for TFP at isosmotic condition
lysis occurs at concentrations beyond the CMC of the drug, indicating that
micellization facilitates TFP hemolytic effect, while DBC and PZQ reach a real
membrane saturation at their monomeric form.
PMID- 10672416
TI - A spectroscopic study of the molecular interactions of harmane with pyrimidine
and other diazines.
AB - FTIR, UV-vis, steady state and time-resolved fluorescence measurements show that
harmane (1-methyl-9H-pyrido/3,4-b/indole) interacts with pyrimidine and its
isomers pyrazine and pyridazine in its ground and lowest singlet states. The
mechanisms of interaction are dependent on both the structure of the diazine and
the nature of the solvent. Thus, in a low polar solvent such as toluene, harmane
forms ground state 1:1 hydrogen-bonded complexes with all the diazines. These
complexes quench the fluorescence of harmane and diminish its fluorescence
lifetime. Conversely, in buffered (pH 8.7) aqueous solutions, pyrimidine behaves
differently from the other diazines. Thus, whereas pyrimidine only interacts with
harmane in its ground state, pyrazine and pyridazine also interact in the excited
state. The harmane-pyrimidine ground state interaction is an entropic controlled
process. Therefore, we propose the formation of pi-pi stacked 1:1 complexes
between these substrates. Association constants for the different types of
complexes and quenching parameters are reported.
PMID- 10672417
TI - In vitro effects of sodium fluoride and sodium dichromate on dynamic properties
of human erythrocyte membrane.
AB - Sodium fluoride (NaF) and sodium dichromate (Na2Cr2O7) are two different toxic
compounds which are used as a dental caries prophylactic and as an oxidising
agent in various industrial areas, respectively. However, accidental fluoride and
chromate poisoning is not a rare occurrence, even death may result from cardiac
or respiratory failure. In the present work, alterations produced by NaF,
Na2Cr2O7 and temperature changes in the molecular dynamics of the human
erythrocyte membrane were studied, in vitro, by the spin-labelling ESR technique.
Human intact erythrocyte cells spin labelled with 5- and 16-doxyl stearic acids
(5-DSA and 16-DSA) and treated with 40 microM NaF and 5 microM Na2Cr2O7 at 37
degrees C were used to quantify membrane fluidity. This was performed by
measuring the changes in the order parameter (S), correlation time (tau) and
phase transition temperature using recorded electron spin resonance (ESR)
spectra. Experimental results show that 5 microM Na2Cr2O7 and 40 microM NaF do
not produce any significant effects on the order parameter of 5-DSA spin label
while they cause appreciable changes in the correlation time of the same label.
As for 16-DSA, while Na2Cr2O7 does not produce any measurable effect on the order
parameter of this label, NaF does in a certain extent. Although weak, the effects
of both compounds on the correlation time of 16-DSA are found to be well above
the experimental error limits. Change in temperature was observed to alter
significantly S and tau parameters which show biphasic character in the
temperature range of 5-50 degrees C. Activation energies of the hydrocarbon
chains above and below transition temperatures were also determined for untreated
and NaF or Na2Cr2O7 treated erythrocyte cells and the effect of NaF and Na2Cr2O7
on these energies and transition temperatures were discussed.
PMID- 10672418
TI - Self-assembled complexes of oligopeptides and metalloporphyrins: measurements of
the reorganization and electronic interaction energies for photoinduced electron
transfer reactions.
AB - Cationic porphyrins form ground state electrostatically associated complexes with
anionic oligo-electrolytes such as those formed by a series of glutamic acid (E)
residues. Temperature dependencies were measured of the rate constants for intra
complex electron transfer to the triplet state of Pd(II)TMPyP4+ from a tyrosine
(tyr, Y) or tryptophan (trp, W) moiety connected to a glutamic acid tetramer. In
complexes such as YE4, E2YE2, YE4G10E (G, glycine), and WE4 these data were used
to estimate the reorganization energy (lambda) and electronic interaction energy
(HDA) relevant to the process. For all tyr-peptide complexes, lambda values were
found to be large (lambda approximately 1.60 +/- 0.06 eV), reflecting a
relatively high medium polarity in the vicinity of tyr residues. It further
indicates that the tyr residues in all oligo-peptides are exposed to the aqueous
medium in a similar way irrespective of the position of the aromatic moiety in
the peptide chain. A significantly lower lambda value (lambda = 1.08 eV) was
derived for the tryptophan-containing peptide complex, indicating a relatively
higher hydrophobic character of trp compared to tyr. The electronic coupling
matrix elements (HDA) derived for tyr-peptide complexes (5.1 meV for YE4, 5.4 meV
for YE4G10E and 7.5 meV for E2YE2) were larger than that found for WE4 (1.1 meV).
Molecular dynamics calculations were employed to obtain structural features of
the porphyrin-peptide complexes. These showed average distances between the
center of mass (COM) of the porphyrin ring and the center of mass of the amino
acid aromatic ring of 816 +/- 140 pm (YE4), 800 +/- 80 pm (E2YE2), 900 +/- 130 pm
(YE4G10E) and 970 +/- 160 pm (WE4). The molecular dynamics calculations were
shown to be in good agreement with the experimentally determined electronic
interaction energies, strongly suggesting that HDA is primarily responsible for
the dependence of the electron-transfer rate constant (KET) on the donor-acceptor
separation distance and relative orientation. The higher HDA (7.55 meV) derived
for tyr incorporated into the middle of the peptide backbone (E2YE2) was presumed
to be associated with a higher degree of orbital overlap due to a more favorable
ring-ring orientation. Overlap parameters (beta derived for all peptide-porphyrin
complexes were similar (approximately 0.95 +/- 0.06 A-1), being in good agreement
with most literature values for similar systems. Finally, the intra-complex
electron-transfer ratio (ktrp/ktyr) derived from flash photolysis experiments and
the corresponding ratio derived from Marcus' theory combined with experimental
data from the temperature-dependence investigations and electrochemical
measurements were found to be in excellent agreement. This same consistency was
found for the couple E4Y and E2YE2. The empirical expression (Moser and Dutton)
governing the intraprotein electron-transfer rate constant in native systems
combined with our experimental data (kET, lambda, delta G0) yielded tunneling
pathway distances in excellent agreement with those arising from the molecular
modeling studies. The exception was for the long peptide YE4G10E, for which the
Quenched Molecular Dynamic (QMD) sampling technique was complicated and is
probably inadequate.
PMID- 10672419
TI - Complexes produced by associated forms of porphyrin bound with hydrophobic
hydrophilic copolymer and transition metal ions.
AB - Properties of protonated dimeric forms of meso-tetraphenylporphine (TPP) and meso
tetra(p-aminophenyl)porphine (TAPP) bound with copolymer and also complexes
produced by associated TAPP bound with copolymer, Mn2+, and Fe3+ are investigated
by absorption, luminescence, and Raman spectroscopy. According to absorption
spectra of protonated dimers of TPP, three dimeric forms of the porphyrin are
observed in the ground state. However, selective excitation of these forms
according to the fluorescence spectra reveals only two dimeric forms in the
excited state. In contrast, similar selective excitation of TAPP bound with
copolymer in aqueous-dioxane solution results in weak changes in the fluorescence
spectra, nevertheless, there is strong interaction between porphyrin and
macromolecular carboxyl groups in the ground state. In the case of the formation
of the complexes between associated TAPP bound with copolymer, Mn2+ and Fe3+, a
new band in the near IR region with a maximum at 840 nm is built up in the
fluorescence spectrum. However, this near IR emission is completely quenched when
new strong vibrational bands at approximately 1800 and 1900 cm-1 are revealed in
the resonance Raman spectra of the complexes. The observed effects are explained
in terms of direct participation of water molecules involved in the water
porphyrin dimeric complex in the processes of transformation of excitation
energy. The involvement of water in this dimeric complex can lead to
redistribution of flows of the energy degradation when transition metal ions play
a role of the agent which enhances the trapping properties of the porphyrin-metal
ions complexes.
PMID- 10672420
TI - Oscillations and bistability predicted by a model for a cyclical bienzymatic
system involving the regulated isocitrate dehydrogenase reaction.
AB - We analyze the dynamics of a bienzymatic system consisting of isocitrate
dehydrogenase (IDH, EC. 1.1.1.42), which transforms NADP+ into NADPH, and of
diaphorase (DIA, EC 1.8.1.4), which catalyzes the reverse reaction. Experimental
evidence as well as a theoretical model showed the possibility of a coexistence
between two stable steady states in this reaction system G.M. Guidi et al.
Biophys. J. 74 (1998) 1229-1240[, owing to the regulatory properties of IDH. Here
we extend this analysis by considering the behavior of the model proposed for the
IDH-DIA bienzymatic system in conditions where the system is open to an influx of
its substrates isocitrate and NADP+ and to an efflux of all metabolic species.
The analysis indicates that in addition to different modes of bistability
(including mushrooms and isolas), sustained oscillations can be observed in such
conditions. These results point to the isocitrate dehydrogenase reaction coupled
to diaphorase as a suitable candidate for further experimental and theoretical
studies of bistability and oscillations in biochemical systems. The results
obtained in this particular bienzymatic system bear on other enzymatic systems
possessing a cyclical nature, which are known to play significant roles in a
variety of metabolic and cellular regulatory processes.
PMID- 10672421
TI - Pneumocephalus associated with aqueductal stenosis: three-dimensional computed
tomographic demonstration of skull-base defects.
AB - Ventriculoperitoneal (VP) shunt placement in patients with aqueductal stenosis
has recently been reported as a cause of pneumocephalus. We report on a patient
with pneumocephalus associated with aqueductal stenosis treated by VP shunting. A
29-year-old woman who had undergone a shunt operation for aqueductal stenosis 7
years previously sustained a whiplash injury in a minor traffic accident.
Computed tomography (CT) revealed massive subdural pneumocephalus, and three
dimensional reconstructions of CT images clearly demonstrated defects in the
skull base overlying the ethmoid sinuses. Both endoscopic III ventriculostomy and
placement of external ventricular drainage were came free of symptoms and
rhinorrhea ceased. Three-dimensionally reconstructed CT images were useful in
detecting the extent of the patient's skull base defect. III Ventriculostomy was
not effective in this case. Direct closure of the skull base by craniotomy was
not necessary, and a programmable valve system was effective in preventing
recurrence of either pneumocephalus or rhinorrhea.
PMID- 10672422
TI - The treatment of Candida albicans shunt infections.
AB - Cerebrospinal fluid shunting procedures are performed for the treatment of
hydrocephalus. Infection of ventriculoperitoneal shunts may create significant
clinical management issues in these patients. The majority of these infections
are bacterial, but occasionally a Candida albicans shunt infection may occur. We
report two patients who acquired Candida albicans shunt infection and discuss
their clinical presentation, management, and successful outcome. The treatment
with or without removal of the shunt and the correct dosage and route of
administration of the antifungal agents is not well documented. The dilemma of
treatment of Candida albicans shunt infections in these patients and review of
the limited literature on this subject are the subjects of this report.
PMID- 10672423
TI - The management of desmoplastic neuroepithelial tumours in childhood.
AB - The authors report on the clinicopathological aspects of and management
strategies for the group of rare, large hemispheric childhood tumours recently
classified as desmoplastic infantile ganglioglioma (DIGG), desmoplastic
astrocytoma of infancy (DACI) and pleomorphic xanthoastrocytoma (PXA). Between
1985 and 1997, ten children (4 with DACIs, 4 with DIGGs and 2 with PXAs) with a
median age of 9.5 months were operated on. All these patients had complete
surgical resections, with two having a preoperative biopsy. This led to an
erroneous diagnosis in both cases of malignant grade 4 astrocytoma. As a result,
one patient had preoperative chemotherapy with no effect. There was one
perioperative death. Histology revealed heterogeneous tumours with malignant
looking areas in 8 of the specimens. None of the patients has had any
postoperative adjuvant treatment. All surviving patients are alive at follow-up
(median 4.2 years). Despite their often malignant appearance, these tumours have
an excellent prognosis, but they can present formidable surgical challenges when
they occur in very young age patients. We believe that surgical excision can
offer a cure and that adjuvant treatment is not necessary. Finally, biopsy is of
little value and may even lead to an erroneous diagnosis and subsequent
mismanagement.
PMID- 10672424
TI - Management of medulloblastoma and ependymoma in infants: a single-institution
long-term retrospective report.
AB - To reduce the sequelae from CNS irradiation (RT), 16 children younger than 3
years with medulloblastoma-PNET (13 cases) and ependymoma (3 cases) were treated
between 1987-1993 according to different postsurgical chemotherapy (CT) programs.
None of these patients presented with metastases. Eleven patients were rendered
disease-free by surgery, while 5 had residual tumor. Adjuvant therapy depended on
patients' age, postsurgical status and parents' consent to radiotherapy (RT).
Nine of the 16 infants remained alive in continuous complete remission from the
first neoplasm (median follow-up 7 years). Three of them had been treated with CT
alone and 6 with combined CT + RT (posterior fossa 4, whole CNS 2). Seven
patients relapsed a median of 13 months after diagnosis, and all 7 of them died
of their disease. Despite the omission of RT in 6 of the 16 patients and
administration of only focal RT in 8 of the 16, the outcome of this series was
satisfactory. Local failure (in 5/7 patients) was the major problem, despite the
high dose of RT used in 2 of these 5. In 4 of 6 evaluable children school
performance was satisfactory. One child in whom the entire CNS was irradiated
developed glioblastoma multiforme 120 months after the first diagnosis of
medulloblastoma.
PMID- 10672425
TI - Traumatic brain stem lesions in children.
AB - Glasgow Coma Scale (GCS) scores on admission may be predictors of outcome in
patients with brain injuries. This study correlated the outcomes of children with
traumatic brain stem lesions with their initial GCS scores and morphological
patterns of injury as shown on computed tomography (CT) or magnetic resonance
(MR) imaging. During the last 16 years, we have treated 1,108 children with brain
injuries. The entire series included only 21 (1.9%) children who had clinical
signs of brain stem lesions with morphological correlates on CT or MR imaging.
Clinical findings were assessed according to the GCS and compared with scores on
the Glasgow Outcome Scale (GOS). Of these 21 children, 16 (76%) had morphological
lesions seen on CT scans. In 5 (24%) of the children only the MR images revealed
brain stem lesions and their CT scans were negative. Generalized severe brain
swelling was present in 6 cases (28%). There was a significant difference in GOS
scores between patients with initial GCS scores of 3 and 4 and those with GCS
scores between 5 and 7 (P < 0.02). Children with intracranial pressure higher
than 40 mmHg had poorer outcomes than patients whose intracranial pressure was
lower, but the differences were not significant. Outcome did not correlate
significantly with morphological patterns of injury or the presence of
extracranial injuries. The GCS is a reliable indicator of severity of injury and
of outcome in children with brain stem injuries. MR imaging was more sensitive
than CT in detecting brain stem lesions.
PMID- 10672426
TI - Acute neuroradiologic findings in young children with inflicted or noninflicted
traumatic brain injury.
AB - Acute CT/MRI findings were examined in a prospective, longitudinal study of 60
children 0-6 years of age hospitalized for moderate to severe traumatic brain
injury (TBI). TBI was categorized as either inflicted (n = 31) or noninflicted (n
= 29). Glasgow Coma Scale scores and perinatal history were comparable in both
groups. Acute CT/MRI studies were visually inspected by a radiologist blind to
group membership. Compared with the noninflicted TBI group, the inflicted TBI
group had significantly elevated rates of subdural interhemispheric and convexity
hemorrhages as well as signs of pre-existing brain abnormality, including
cerebral atrophy, subdural hygroma, and ex vacuo ventriculomegaly.
Intraparenchymal hemorrhage, shear injury, and skull fractures were more frequent
after non-inflicted TBI. Subarachnoid hemorrhage and infarct/edema occurred with
comparable frequency in both groups. Characteristic acute neuroimaging findings
of inflicted TBI included multiple extraaxial hemorrhages in addition to the mild
atrophy, subdural hygromas, and ventriculomegaly that suggest prior brain
abnormality.
PMID- 10672427
TI - Stormy onset of benign childhood epilepsy with occipital paroxysmal discharges.
AB - We studied six children with ages ranging from 4 to 10 years who were affected by
childhood epilepsy with occipital paroxysms and presented after a stormy onset
with prolonged loss of consciousness for 6-14 h. In all these patients, seizures
were preceded by visual symptoms in the form of colored circular disks. A CT scan
was performed immediately after the onset of symptoms and was normal in all
patients. Routine laboratory and cerebrospinal fluid examinations were normal in
all patients. The interictal EEG was characterized by continuous or subcontinuous
occipital spike wave discharges, which disappeared after the patients' eyes
opened. We carried out a 7-year follow-up of all these patients. Only two
patients were treated with antiepileptic drugs. The therapy (phenobarbital,
clobazam) in the two patients did not induce changes in the EEG pattern. The
first did not suffer any further seizures. The second patient had two more
seizures (at 8 and 18 months from the onset) with phosphenes, confusional state,
and involuntary movements followed by loss of consciousness. Among the other four
patients, who did not receive any treatment, only one had any other seizures. The
stormy onset of the syndrome described in our six patients emphasizes the extreme
variability in the presentation of this type of childhood epilepsy. Our follow-up
confirms the good prognosis of this epilepsy even when it has a stormy onset.
PMID- 10672428
TI - Brain death in children: clinical, neurophysiological and radioisotopic
angiography findings in 125 patients.
AB - The objective of this study was to determine the main clinical,
neurophysiological and angiographic findings in brain death (BD) in children seen
at the Instituto Nacional de Pediatria, a third-level facility in Mexico City,
between 1991 and 1996. The following variables were retrospectively analyzed:
sex, age, etiology, associated morbidity, duration of stay in hospital, and the
results of two of three confirmatory studies (electroencephalogram, evoked
potentials, radioisotopic angiography). In all, 125 patients were studied 78
male, median age 2 years (range: 18 days to 17 years)[. The most frequent
etiology was infection (34%); 57% of the children developed associated morbidity.
In 111 of 122 patients electrocerebral silence was observed; 100 of 107 had brain
stem and somatosensory evoked potentials affording conclusive evidence of BD; and
83 of 90 patients had a positive radioisotopic angiography indicating BD. In 76
patients all three confirmatory studies were performed: for 15 there was at least
one false-negative test result. Our age cohort showed a predominance of children
less than 2 years old. BD etiologies in developing countries differ from those
reported in developed countries.
PMID- 10672429
TI - Period shift induction by intermittent stimulation in a Drosophila model of PER
protein oscillations.
AB - PER protein circadian oscillations in Drosophila have been described by Goldbeter
according to a five-dimensional model that includes the possibility of genetic
mutation described by changing one parameter, the maximum degradation rate of the
PER protein. Assuming that, in a mutant Drosophila this parameter is unreachable,
we modify another parameter, the translation rate between the mRNA and the
nonphosphorylated form of PER protein, by periodic intermittent activation or
inhibition. We show how such a modification, simulated in the model by a
periodic, on/off, piecewise constant stimulation (which increases or decreases
this parameter) allows the entrainment of oscillations exactly at, or close to, a
desired period. In a different context, this suggests that some diseases may be
corrected using pharmacological agents according to specific periodic delivery
schedules.
PMID- 10672430
TI - Pineal influence on annual nuclear volume changes in ventromedial hypothalamic
nucleus (VMH) neurons of the male Wistar rat.
AB - The ventromedial hypothalamic nucleus (VMH) regulates various autonomic,
endocrine, and behavioral activities. These activities show annual changes, and
the pineal gland is involved in their adjustment to environmental cues.
Therefore, this study investigated whether the VMH belongs to the effector
structures of the pineal gland. To abolish the rhythmic melatonin release, male
Wistar rats were subjected to pinealectomy (PX) or ganglionectomy (sympathetic
denervation of the pineal gland, GX) regularly at the beginning of any of the
four seasons. Brains from animals of PX-, GX-, and sham-operated control groups
were prepared 3 months later for measurement of the nuclear volume, which changes
according to the general gene activity. At each of the four seasons, 2000 nuclei
of VMH neurons stemming from 18 animals per group were measured to obtain both
seasonal daily mean values and annual mean values, respectively, as well as to
calculate annual curves of the nuclear volume using empirical regression and
locally adjusted polynomial approximation. The major findings are the following.
First, inactivation of the pineal function influences the nuclear activity of VMH
neurons, (2) PX and GX mainly depress the nuclear activity, indicating that the
pineal influence on the VMH may predominantly be a stimulatory one. Third, size
and direction of the changes caused by PX and GX vary in a seasonally dependent
manner. Fourth, the annual rhythm of the nuclear activity of the VMH is modified
by PX and GX. To explain how the pineal effects on the VMH may be mediated, a
possible inhibitory influence of the suprachiasmatic nucleus (SCN), which has
been activated in the same animals following both PX and GX, is discussed. In
conclusion, the results confirm that the nuclear activity of VMH neurons
underlies pineal influences. This also indicates an involvement of the pineal
gland in many VMH-regulated functions.
PMID- 10672431
TI - Quantitative tests of a dual circalunidian clock model for tidal rhythmicity in
the sand beach isopod Cirolana cookii.
AB - In constant conditions (constant darkness DD[, 20 degrees C), the sand beach
isopod Cirolana cookii exhibits spontaneous rhythmic swimming activity with an
average free-running period of 12.5 h. The rhythms are seen as temporal
adaptations to a complex interidal environment. These results support a dual
circalunidian clock model for tidal rhythms in which two components of the rhythm
have characteristic periods and active phase lengths and are hypothesized to be
controlled by separate circalunidian clocks. A quantitative model successfully
simulates many of the properties of endogenous swimming rhythms of C. cookii,
including free-running behavior, entrainment, and phase-response curves (PRCs).
PMID- 10672432
TI - Evidence of circadian rhythm of electric discharge in Eigenmannia virescens
system.
AB - The gymnotid electric fish, Eigenmannia virescens, exhibits electric discharge
rhythmicity both in alternate light-dark (LD; 12 h light, 12 h dark [LD 12:12])
and in constant dark (DD) conditions. It suggests that the electric discharge
rhythm is under control of the circadian clock. The free-running periods (FRPs)
of electric discharge rhythms at 21 degrees C in DD are greater than, but close
to, 24 h. The maximum of the electric discharge in the Eigenmannia system peaks
approximately at circadian time 6 (CT6) in the middle of the subjective day. The
circadian oscillator in the system is temperature compensated. This original
report reveals the relationship between electric discharge activity and the
circadian pacemaker in Eigenmannia and provides an alternative system to
investigate circadian rhythms in vertebrates.
PMID- 10672433
TI - The sleep of healthy people--a diary study.
AB - To provide baseline data for various research studies at the University of
Pittsburgh over a 10-year period, 266 healthy subjects (144 male, 122 female,
aged 20-50 years) meeting certain criteria each completed a 14-night sleep diary.
For each night, the diary allowed the subjective measurement of bedtime, wake
time, time in bed (TIB), sleep efficiency, number of minutes of wake after sleep
onset (WASO), alertness on awakening, and percentage of morning needing an alarm
(or a person functioning as one). Weeknight versus weekend night differences in
TIB (TIBdiff), weekday altertness, and reliance on alarms were examined as
possible indicators of sleep debt. In addition, general descriptive data were
tabulated. On average, bedtimes were at 23:48 and wake times at 07:23, yielding a
mean TIB of 7 hours 35 minutes. As expected, bedtimes and wake times were later
on weekend nights than on weeknights. Bedtimes were 26 minutes later, wake times
53 minutes later, yielding a mean weekend TIB increase of 27 minutes. Overall,
subjects perceived their sleep latency to be 10.5 minutes, reported an average of
one awakening during the night (with an average of 6.4 minutes of WASO), had a
diary sleep efficiency of 96.3%, and awoke with an alterness rating of 69.5%.
These variables differed little between weeknight and weekend nights. Subjects
used an alarm (or a person functioning as an alarm) on 60.9% nights overall,
68.3% on weeknights, 42.5% on weekends. When TIBdiff was used as an estimate of
sleep debt (comparing subjects with TIBdiff > 75 minutes with those with a
TIBdiff < 30 minutes), the group with more "catch-up sleep" on weekends had
shorter weeknight TIB durations (by about 24 minutes) and relied more on an alarm
for weekday waking (by about 22%), indicating the possible utility of these
variables as sleep debt indices.
PMID- 10672434
TI - Day-night pattern in accidental exposures to blood-borne pathogens among medical
students and residents.
AB - The purpose of this study was to determine whether the occurrence of accidental
blood-borne pathogen exposure incidents in medical students and residents in
training varies during the 24 h. A retrospective review of reported exposures was
conducted in a large urban teaching institution--the University of Texas Health
Science Center in Houston--between November 1993 and July 1998. Professional
level (year of student or level of resident), time of exposure, means/route of
exposure (needle stick, laceration, or splash), and type of medical service were
recorded. Analysis of the clock time of the 745 reported blood-borne pathogen
exposures showed they occurred more frequently during the day than night. Over
the nearly 5-year span, 531 incidents took place between 06:00 and 17:59 in
comparison to only 214 between 18:00 and 05:59. To account for the day-night
difference in medical student and resident hospital staffing, the data were
reexpressed as exposure rates, that is, in terms of the number of events per hour
per 1000 medical students and residents. Based on the total number of reported
exposures over the almost 5-year span of data collection, the average rate was 40
accidents per hour per 1000 doctors in training during the 12 h daytime span
(6:00-17:59). It was 50% greater at night (18:00-05:59), with 60 incidents per
hour per 1000 doctors in training. The day-night difference in rate of exposures
was statistically significant (p < .04). The relative risk ratio for residents
and students when working during the day shift compared to working the night
shift was 0.67. This means that doctors in training are at a 1.50 higher risk of
sustaining a blood-borne pathogen exposure when working nights than when working
days.
PMID- 10672435
TI - Effect of melatonin on sleep quality of COPD intensive care patients: a pilot
study.
AB - Sleep deprivation is extremely common in the intensive care unit (ICU), and this
lack of sleep is associated with low melatonin secretion. The objective of the
current study was to explore the effect of exogenous melatonin administration on
sleep quality in patients hospitalized in the pulmonary intensive care unit
(ICU). We performed a double-blind, placebo-controlled study in the pulmonary ICU
of a tertiary care hospital. Eight adult patients hospitalized in the pulmonary
ICU with respiratory failure caused by exacerbation of chronic obstructive
pulmonary disease (COPD) or with pneumonia were studied. Patients received either
3 mg of controlled-release melatonin or a placebo at 22:00, and sleep quality was
evaluated by wrist actigraphy. Treatment with controlled-release melatonin
dramatically improved both the duration and quality of sleep in this group of
patients. Our results suggest that melatonin administration to patients in
intensive care units may be indicated as a treatment for sleep induction and
resynchronization of the "biologic clock." This treatment may also help in the
prevention of the "ICU syndrome" and accelerate the healing process.
PMID- 10672436
TI - Algorithm for application of Fourier analysis for biorhythmic baselines of
pharmacodynamic indirect response models.
AB - The change of an indirect pharmacological response R(t) can be described by a
periodic time-dependent production rate kin(t) and a first-order loss constant
kout. If kin(t) follows some biological rhythm (e.g., circadian), then the
response R(t) also displays a periodic behavior. A new approach for describing
the input function in indirect response models with biorhythmic baselines of
physiologic substances is introduced. The present approach uses the baseline
(placebo) response Rb(t) to recover the equation for kin(t). Fourier analysis
provides an approximate equation for Rb(t) that consists of terms (usually two or
three) of the Fourier series (harmonics) that contribute most to the overall sum.
The model differential equation is solved backward for kin(t), yielding the
equation involving Rb(t). A computer program was developed to perform the square
L2-norm approximation technique. Fourier analysis was also performed based on
nonlinear regression. Cortisol suppression after inhalation of fluticasone
propionate (FP) was modeled based on the inhibition of the secretion rate kin(t)
using ADAPT II. The pharmacodynamic parameters kout and IC50 were estimated from
the model equation with kin(t) derived by the new approach. The proposed method
of describing the input function needs no assumption about the behavior of
kin(t), is as efficient as methods used previously, and is more flexible in
describing the baseline data than the nonlinear regression method.
PMID- 10672437
TI - Chronic fatigue syndrome beginning suddenly occurs seasonally over the year.
AB - The fact that many patients with chronic fatigue syndrome (CFS) have an
infectious like sudden onset to their illness has led to the hypothesis that CFS
is a medical illness. If CFS were, on the other hand, a psychiatric disorder
related to symptom amplification, one would expect illness onset to occur
randomly over the calendar year. This study tested that hypothesis with 69 CFS
patients whose illness was on the more severe side of the illness spectrum; all
patients reported sudden illness onset with the full syndrome of sore throat,
fatigue/malaise, and diffuse achiness developing over no longer than a 2-day
period. Date of illness onset was distinctly nonrandom. It peaked from November
through January and was at its lowest from April through May. These data support
the hypothesis that an infectious illness can trigger the onset of CFS.
PMID- 10672438
TI - Examination of the transcriptional specificity of an enological yeast. A pilot
experiment on the chromosome-III right arm.
AB - The adaptation of yeasts to industrial environments is thought to be largely
dependent on gene-expression specificity. To assess the transcriptional
specificity of an enological strain, we performed a pilot experiment and examined
the transcript level of 99 ORFs of the chromosome-III right arm with two strains,
an enological-derived strain and a laboratory strain, grown under three different
physiological conditions: respiration, standard alcoholic fermentation and
enological alcoholic fermentation. The use of 99 single ORF-derived probes led to
the detection of 49 transcripts, most of which were present at low levels and
were not regulated. Ethanol respiration induced transcripts, in a similar manner
with both strains. While standard alcoholic fermentation led to only minor
regulations, the enological fermentation conditions triggered the expression of
different genes. In addition, a specific transcriptional response to these
conditions was observed with the enological-derived strain. The known or
predicted functions of several genes induced under enological conditions is
related to either alcoholic fermentation or stress, suggesting that their
specific induction could reflect adaptation of the strain to the enological
environment. Our data suggest that systematic transcriptional studies are an
effective way to assess the molecular basis of yeast adaptation to industrial
environments.
PMID- 10672439
TI - The cyanobacterial origin and vertical transmission of the plastid tRNA(Leu)
group-I intron.
AB - We have surveyed the distribution and reconstructed the phylogeny of the group-I
intron that is positioned in the anticodon loop of the tRNA(Leu) gene in
cyanobacteria and several plastid genomes. Southern-blot and PCR analyses showed
that the tRNA(Leu) intron is found in all 330 land plants that were examined. The
intron was also found, and sequenced, in all but one of nine charophycean algae
examined. Conversely, PCR analyses showed that the tRNA(Leu) group-I intron is
absent from the red, cryptophyte and haptophyte algae, although it is present in
three members of the heterokont lineage. Phylogenetic analyses of the intron
indicate that it was present in the cyanobacterial ancestor of the three primary
plastid lineages, the Rhodophyta, Chlorophyta, and Glaucocystophyta. Its present
day distribution in plastids is consistent with a history of strictly vertical
transmission, with no losses in land plants, several losses among green algae,
and nearly pervasive loss in the Rhodophyta and its secondary derivatives.
PMID- 10672440
TI - Recombinant mitochondrial DNA molecules suggest a template switching ability for
group-II-intron reverse transcriptase.
AB - Degenerative processes in the filamentous fungus Podospora anserina are strongly
correlated with the instability of the mitochondrial genome. Among the sources of
instability is the mobile group-II intron COX1-i1, also called intron alpha,
which encodes a protein with a reverse transcriptase activity. In this paper we
characterize, through PCR experiments, mitochondrial recombinant DNA molecules
joining the 5' end of intron alpha to the 3' end of tRNA sequences including the
CCA motif. The structure of these junctions led us to propose that they were most
probably initiated by a RNA template switching of the reverse transcriptase
encoded in COX1-i1. This activity might be involved in a number of mitochondrial
rearrangements occurring in degenerative syndromes and in some long-lived
mutants.
PMID- 10672441
TI - Phylogenetic analysis of diatom coxI genes and implications of a fluctuating GC
content on mitochondrial genetic code evolution.
AB - In order to address the relationships among diatom groups and to investigate
possible changes in their mitochondrial (mt) genetic codes, we have analyzed a
1.1-kb region of the cytochrome c oxidase subunit I (coxI) gene from eight
diverse diatom species. A phylogenetic analysis of these coxI sequences including
representative species of the Phaeophyta, Xanthophyta, Eustigmatophyta and
Haptophyta showed that the diatoms (Bacillariophyta) formed a well-supported
monophyletic group. Of the eight species investigated, four have been classified
together as radial centric diatoms based on morphology. However, in our coxI
tree, the two radial centrics belonging to the order Thlassiosirales (Skeletonema
costatum and Thalassiosira nordenskioldii) were placed as the sister group to the
multipolar centric diatoms, while the other two radial centrics (Melosira ambigua
and Rhizosolenia setigera) were in another clade. Also, in two species of the
Tharassiosirales we found UGA codons that occur at conserved tryptophan (Trp)
sites in the coxI sequences, strongly indicating that UGA codes for Trp in these
diatoms. No evidence of a deviant genetic code was detected in the other analyzed
diatom species. There was no apparent relationship between the nucleotide third
position GC content of mtDNA (based on the sequenced coxI region) and the
presence of a deviant genetic code.
PMID- 10672442
TI - Variable number of tandem repeat loci in the mitochondrial genomes of beets.
AB - We found four unrelated tandem repeat loci (TR1, TR2, TR3 and TR4) in the
mitochondrial genomes of beets, with the TR1 locus embedded within a three
membered family of recombining repeat sequences (the rrn26-repeat). TR1 is
composed of an array of 32-bp tandem repeats, the number of which varies from 2
to 13 among the seven beet genotypes examined. It is interesting to note that TR1
has 7-bp direct repeats flanking the array, which may be involved in the
generation of the tandem repeat array. Such striking features are shared by the
remaining TR loci, and this is thus the first description of minisatellite
nucleotide sequences from a higher-plant mitochondrial genome.
PMID- 10672443
TI - Kalilo plasmids are a family of four distinct members with individual global
distributions across species.
AB - Kalilo is a linear 9-kb plasmid, isolated originally from Hawaiian strains of the
heterothallic fungus Neurospora intermedia. Its properties include terminal
inverted repeats, two ORFs coding for a presumptive DNA and an RNA polymerase,
and the ability to cause senescence in its original host and in the closely
related species Neurospora crassa. We have examined natural isolates alleged to
contain plasmids homologous to kalilo. Most of these isolates do in fact contain
plasmids with so close an identity to kalilo as to be certain relatives. We found
a new case of kalilo in Neurospora tetrasperma from Moorea-Tahiti, and a new case
of LA-kalilo (previously found only in N. tetrasperma) in N. crassa from Haiti. A
previously unreported, substantially shorter, kalilo variant has been found in
three geographically separate isolates of the heterothallic species Neurospora
discreta. Therefore, if the previously reported kalilo variant from the genus
Gelasinospora is included, in all there are four members of the kalilo plasmid
family. The main differences between these plasmids are in the terminal inverted
repeats (TIRs). The phylogeny of the TIR sequences is largely congruent with that
of nuclear DNA in the species in which they are found, suggesting that the
plasmids are related by vertical descent throughout the evolution of these
species. However, there are two cases of a plasmid found in a heterothallic and a
pseudohomothallic species in the same global area; these cases might have arisen
from more recent horizontal transmission or introgression.
PMID- 10672444
TI - Transcripts and sequence elements suggest differential promoter usage within the
ycf3-psaAB gene cluster on mustard (Sinapis alba L.) chloroplast DNA.
AB - The mustard chloroplast DNA region spanning the ycf3 gene and part of the psaAB
operon was investigated. The ycf3 gene reveals two class-II introns that are
removed during processing to give a mature 0.7-kb transcript, but no RNA editing
seems to be involved. RNase protection and RT-PCR experiments suggest
cotranscription of ycf3 with the downstream psaA gene, possibly from a NEP
promoter upstream of ycf3, whereas distinct ycf3 and psaA transcripts are each
initiated from PEP promoters. This situation is reminiscent of that for the trnK
psbA gene region. The implications for light-regulated versus light-independent
expression of photosystem core-protein genes are discussed.
PMID- 10672445
TI - Maternal inheritance of chloroplasts in the horsetail Equisetum variegatum
(Schleich.).
AB - Reliable data concerning the transmission of chloroplasts in the Pteridophyta are
needed both for phylogenies based on chloroplast DNA (cpDNA) sequences and in
order to study the evolution of this trait in conjunction with the evolution of
the life cycle and the sexual reproduction of land plants. For the first time,
this paper describes organelle transmission in the division Sphenophyta,
represented by the extant genus Equisetum. By following the fate of polymorphic
cpDNA during three intraspecific reciprocal crosses we found no trace of paternal
transmission in Equisetum variegatum. The seemingly strict maternal transmission
of cpDNA in this species suggests that uniparental chloroplast inheritance
preceded the evolution of heterospory in the seed-plant lineage.
PMID- 10672446
TI - Molecular characterization of a PDI-related gene prpA in Aspergillus niger var.
awamori.
AB - A gene (prpA) homologous to the protein disulfide isomerase gene was isolated
from Aspergillus niger by Southern hybridization using the pdi1 gene isolated
from Trichoderma reesei as a DNA probe. The corresponding cDNA of the prpA gene
has also been isolated from an A. niger var. awamori cDNA library. The prpA gene
does not belong to any currently recognized family of protein disulfide
isomerases since it contains only a single conserved thioredoxin domain at the N
terminus of the protein. The C-terminal two-thirds of the protein has no homology
to any known proteins in the database. The PRPA protein contains an ER retention
signal (HDEL) at its C-terminal end suggesting that it is located in the ER.
Southern hybridization at high stringency showed that it was present as a single
copy in the genome. Northern hybridization indicated that the transcript level of
the prpA gene was higher if the cells were secreting a heterologous protein,
bovine prochymosin. However, over-expression of the prpA gene from a multicopy
integrated vector had little effect on chymosin secretion. A strain containing a
deletion of the prpA gene was viable. However, deletion of the prpA gene appeared
to cause a reduction of bovine chymosin production.
PMID- 10672448
TI - The 20th century--the frame that we leave.
PMID- 10672447
TI - Cytochrome P450 oxidoreductase gene and its differentially terminated cDNAs from
the white rot fungus Phanerochaete chrysosporium.
AB - The white rot fungus Phanerochaete chrysosporium metabolizes a range of
xenobiotics via P450 mono-oxygenation, particularly under peroxidase-suppressing
culture conditions. Here we report the cloning and analysis of the gene from this
fungus for the cytochrome P450 oxidoreductase (CPR) and its differentially
terminated cDNAs. Using a PCR-based approach with degenerate primers, a 285-bp
genomic fragment was isolated from the two widely studied strains BKM-F 1767 and
ME 446, and was identified as a CPR gene segment based on sequence comparison
with the database. A clone containing the full-length CPR gene was isolated from
a BKM-F 1767 genomic library using the PCR-generated segment as a probe, and the
3937-bp insert was sequenced by gene walking. Based on the detection of conserved
CPR motifs, a coding region of 2381 bp was identified with a 991-bp segment 5' to
the putative ATG start codon. Two cDNAs with differentially terminated
transcripts were isolated and sequenced. Comparison of the gene and the cDNA
sequences confirmed the presence of three introns (62 bp, 50 bp, and 58 bp).
Sequence identity and a phylogenetic comparison of the deduced protein (736 aa)
with other CPRs in the database suggested that P. chrysosporium CPR is the
largest CPR known and is more closely related to animal (36-38%) and yeast (37
38%) CPRs than to plant CPRs (33-35%). The availability of this gene will
facilitate further studies on understanding the potent xenobiotic mono
oxygenation systems in this model white rot fungus.
PMID- 10672449
TI - The cost-effectiveness of different management strategies for type I diabetes: a
Swiss perspective.
AB - AIMS/HYPOTHESIS: A computer model was developed to determine the health outcomes
and economic consequences of different combinations of diabetes interventions in
newly diagnosed patients with Type I (insulin-dependent) diabetes in Switzerland.
METHODS: We modelled seven complications of diabetes: hypoglycaemia,
ketoacidosis, acute myocardial infarction, stroke, lower extremity amputation,
nephropathy, and retinopathy. Transition probabilities and costs were taken from
published literature. The Swiss health insurance payer perspective was taken.
Various combinations of diabetes management strategies, including intensive or
conventional insulin therapy and screening and treatment strategies for renal and
eye disease were defined. Life expectancy, cumulative incidences of
complications, and mean expected total lifetime costs per patient were calculated
under six different management strategies. Incremental cost-effectiveness ratios
were calculated in terms of costs per life-year gained compared with conventional
insulin therapy alone. RESULTS: The addition of screening for microalbuminuria
and retinopathy followed by appropriate treatment, if detected, were cost saving,
with reduction in cumulative incidence of end stage renal disease and blindness
respectively, and, in the case of microalbulminuria screening and treatment, an
improvement in life expectancy. Intensive therapy improved life expectancy but
increased total lifetime costs. CONCLUSION/INTERPRETATION: Optimal management of
Type I diabetic patients, including secondary and tertiary prevention, leads to
reduced complications and improved life expectancy, with the increased costs of
prevention offset to varying degrees by cost savings due to complications
avoided.
PMID- 10672450
TI - Effects of diabetic cardiomyopathy on regional electrophysiologic characteristics
of rat ventricle.
AB - AIMS/HYPOTHESIS: To identify the possible causes of the lengthening of the action
potential duration described in patients affected by diabetes mellitus. METHODS:
We studied the effects of streptozotocin-induced diabetes on the current density
of the repolarising potassium currents It(o), IK, Iss and IK1 in enzymatically
isolated myocytes from three different regions of rat heart: total right
ventricle, subepicardium at the apex of the left ventricle and subendocardium at
the base of the left ventricle. RESULTS: No changes in IK1 were found due to
diabetes, but there was a uniform decrease in It(o) (50%) and Iss (40%) current
densities in the three regions. In contrast, IK diminished unevenly, with the
greatest decrease in the subendocardium at the base of the left ventricle (48%),
followed by the subepicardium at the apex of the left ventricle (32%) and right
ventricle (10%). CONCLUSION/INTERPRETATION: These findings suggest the existence
of regional differences in ion channel expression associated with diabetes. The
decrease of these repolarising currents could account for the lengthening of
action potential and the consequent change in the Q-T interval of the ECG
observed in diabetic rats.
PMID- 10672451
TI - Functional and structural abnormalities in the nerves of type I diabetic baboons:
aminoguanidine treatment does not improve nerve function.
AB - AIMS/HYPOTHESIS: To improve understanding of the pathophysiology of diabetic
neuropathy and to establish a primate model for experimental studies, we examined
nerve changes in baboons with Type I (insulin-dependent) diabetes mellitus. We
also examined the effect of aminoguanidine (an inhibitor of the formation of
advanced glycation end products) on nerve function. METHODS: Male baboons (Papio
hamadryas) were assigned to four groups; control, diabetic, control and diabetic
treated with aminoguanidine. Diabetes was induced with streptozotocin (60 mg/kg,
intravenous). Insulin and aminoguanidine (10 mg/kg) were injected subcutaneously
daily. Motor and sensory nerve conduction velocity was measured using standard
techniques. Autonomic function was examined by measuring heart rate response to
positional change. Sural nerve morphometry was analysed in the diabetic group
(mean duration 5.5 years) along with their age-matched controls. RESULTS: The
diabetic groups were smaller in size with a mean HbA1c of 8.9 +/- 1.2%. The nerve
conduction velocity and heart rate response was reduced in the diabetic groups.
Morphometric analysis of the diabetic sural nerve showed smaller axon diameter
(2.99 +/- 0.06 microns vs 3.29 +/- 0.06 microns; p < 0.01) accompanied by thinner
myelin (1.02 +/- 0.02 microns vs 1.15 +/- 0.02 microns, p < 0.01) with no change
in the axon density. Treatment with aminoguanidine for 3 years had no effect on
glycaemic control and did not restore conduction velocity or autonomic
dysfunction in the diabetic animals, contrary to the studies in rats.
CONCLUSIONS/INTERPRETATION: These results show that the primate is a good model
to study diabetic neuropathy and suggest that the accumulation of advanced
glycation end products are not an early mechanism of nerve damage in this
disorder.
PMID- 10672452
TI - Excessive fat accumulation is associated with the TNF alpha-308 G/A promoter
polymorphism in women but not in men.
AB - AIMS/HYPOTHESIS: Tumour necrosis factor alpha (TNF alpha) is a candidate gene for
the development of obesity, which in turn is a major risk factor for diabetes
mellitus. The aim of our study was to investigate whether a previously known NcoI
sensitive polymorphism (-308 G/A) in the promoter region of the TNF alpha gene
was related to body weight. METHODS: Genotyping was done in 239 male and 342
female non-diabetic subjects with a marked variation in body mass index (BMI).
RESULTS: We found three genotypes; AA (n = 13), AG (n = 158) and GG (n = 410).
When the material was divided according to sex, allele specific phenotypic
differences were confined to women. The female subjects carrying the AA genotype
were markedly more obese than both the AG and GG carriers (mean BMI = 41.4 vs
32.3 and 31.7 kg/m2, respectively, p = 0.02). The body fat content of female AA
carriers was increased by one-third compared with AG/GG carriers (p = 0.02). We
found no differences between genotypes with respect to waist-to-hip ratio, blood
pressure or metabolic variables. Among obese female subjects (BMI > 27 kg/m2), we
also found that the BMI and body fat content of AA carriers (n = 7) were also
higher than for AG/GG carriers. CONCLUSION/INTERPRETATION: The AA-variant at
position -308 in the promoter region of the TNF alpha gene could be an important
genetic factor behind excessive fat accumulation in women.
PMID- 10672453
TI - Cloning of cDNA and the gene encoding human hepatocyte nuclear factor (HNF)-3
beta and mutation screening in Japanese subjects with maturity-onset diabetes of
the young.
AB - AIMS/HYPOTHESIS: Molecular defects of the genes for transcription factors,
hepatocyte nuclear factor (HNF)-4 alpha, HNF-1 alpha, HNF-1 beta and insulin
promoter factor-1 cause maturity-onset diabetes of the young (MODY1, 3, 5, and 4,
respectively). This suggests the HNF-related transcription cascade is important
in insulin secretion which is induced by glucose. These genes and the gene
encoding glycolytic enzyme glucokinase (MODY2) are, however, responsible for only
15-20% of cases of MODY in the Japanese. Searching for a novel form of MODY in
this population, we cloned a new candidate gene encoding human HNF-3 beta, a
winged helix transcription factor, which also belongs to the same HNF
transcription cascade. METHODS: The cDNA clone for human HNF-3 beta was isolated
from a liver cDNA library. The gene was also cloned from a genomic library and
its organization and chromosomal localization were determined. We screened 68
Japanese subjects with MODY/early-onset diabetes for mutations in this gene.
RESULTS: Human HNF-3 beta is composed of 457 amino acids. The human gene, which
was mapped to the segment 30 cR from SHGC-37039 on chromosome 20p by radiation
hybrid mapping, spans approximately 4.5 kb and consists of three exons. Direct
sequencing of the exons and flanking regions identified one missense mutation
A328 V and seven polymorphisms, although the functional significance of the
mutation in the pathogenesis of diabetes is not known. CONCLUSION/INTERPRETATION:
The characterization of the structure of the HNF-3 beta gene and its mapping in
the framework of markers will be helpful in genetic studies of the various forms
of diabetes mellitus.
PMID- 10672454
TI - Are randomized controlled trials sufficient evidence to guide clinical practice
in type II (non-insulin-dependent) diabetes mellitus?
AB - Randomized controlled trials (RCTs) are often considered the standard for
defining the practice of evidence-based medicine. Taken alone, they are, however,
often insufficient to guide clinical care. Randomized controlled trials are
clearly the best method to determine whether interventions are efficacious. They
have, however, numerous limitations which make them difficult to carry out or
limit applicability to routine clinical practice. Although observational studies
also have inherent limitations, they provide data which can help to further
explain the results of randomized controlled trials. The use of observational
studies to frame randomized trials can allow better application of randomized
controlled trial results to individual patients and can thus help to optimize
delivery of care, inform clinical practice and determine the need for further
such trials.
PMID- 10672455
TI - Hepatocyte nuclear factor-1 beta (MODY5) gene mutations in Scandinavian families
with early-onset diabetes or kidney disease or both.
PMID- 10672456
TI - Accuracy of fasting glucose to diagnose diabetes in Brazilian subjects.
PMID- 10672457
TI - Comments on the relation among GAD-65, IA-2 antibodies and body adiposity.
PMID- 10672458
TI - 125 years of enantiomers--back to the roots Jacobus Henricus van't Hoff 1852
1911.
PMID- 10672459
TI - Developing a chiral toolbox for asymmetric catalytic reactions.
AB - During the last several decades, chemists have made major progress in discovering
man-made catalysts to perform challenging asymmetric transformations. The
research in our group addresses fundamental and practical problems in this field
by developing a diverse set of chiral ligands that combine with transition metals
to form highly enantioselective catalysts. Families of tridentate ligands have
been developed for the enantioselective hydrogenation of unfunctionalized
substrates. In addition, we have developed several new bidentate phosphine
ligands for asymmetric catalysis. The common feature of these ligands are that
they contain rigid aromatic backbones or ring structures which restrict
conformational flexibility of the ligands. Several asymmetric reactions have been
studied: asymmetric hydrogenation of functionalized substrates such as N
acylaminoacrylic acids, enamides and enol acetates; asymmetric hydrogenation of
simple ketones, and imines; and asymmetric carbon-carbon bond forming reactions.
In addition, we have designed and synthesized several novel chiral monophosphines
for asymmetric catalytic reactions. Transition metal complexes with these
monophosphines have also been developed for asymmetric transformations.
PMID- 10672460
TI - Stereoselective conjugate additions to enoates.
PMID- 10672461
TI - Chemical process evolution of efavirenz, a potent non-nucleosidal HIV reverse
transcriptase inhibitor.
PMID- 10672462
TI - The origins of heterogeneous catalysis by platinum: Johann Wolfgang Dobereiner's
contributions.
AB - A number of examples of what Jons Jacob Berzelius was later (1835) to call
catalysis, have been known from antiquity. One of the most prominent of these,
dating from the early eighteenth century, was the action of platinum black on
hydrogen observed in 1823 by Johann Wolfgang Dobereiner (1780-1849), Professor of
Chemistry and Technology at the Universitat Jena (1810-1849), who is regarded as
the discoverer of platinum catalysis. His startling discovery led to his
invention of the widely used pneumatic gas lighter (Dobereinersches Feuerzeug)
and was cited by Berzelius in his formulation of the concept of catalysis.
PMID- 10672463
TI - Control of enantioselectivity in catalytic metal carbene reactions.
AB - Chiral dirhodium(II) complexes constructed from 2-oxopyrrolidine, 2
oxazolidinone, N-acyl-2-imidazolidinone, or 2-azetidinone ligands are exceptional
catalysts for enantioselective metal carbene transformations which provide
lactones and lactams via cyclopropanation, cyclopropenation, C-H insertion, and
ylide reactions with enantiomeric excesses greater than 90% and, usually, in very
high yields. These chiral catalysts present high diastereo-, regio- and
chemoselectivities, turnover numbers up to 1000, as well as recoverability and
reuse.
PMID- 10672464
TI - Mapping of c-Fos in the trigeminal sensory nucleus following high- and low
intensity afferent stimulation in the rat.
AB - Although previous studies have suggested that nociceptive afferents from intra
oral and facial structures are organized differently in the trigeminal sensory
nucleus (TSN), more detailed data are needed. The present study aimed to fill
this gap, by examining the changes in the expression of c-Fos within the rat TSN
following high- and low-intensity electrical stimulation applied to the Gasserian
ganglion (GG). A low-intensity stimulus (0.1 mA) induced c-Fos in many neurons in
the dorsomedial subdivision (Vodm) of the oral subnucleus (Vo; mean +/- SEM in a
certain segment = 163.0 +/- 42.7), in the medial part of the dorsomedial
subdivision (Vidm) of the interpolar subnucleus (Vi; 120.5 +/- 40.1), in the
medial corner of the magnocellular zone (VcIII/IV; 47.5 +/- 10.5), and in the
superficial layers (VcI/II; 1330.0 +/- 65.6) along the entire length of the
dorsomedial-ventrolateral axis of the caudal subnucleus (Vc). A modest number of
Fos-positive neurons were induced in the dorsal principal subnucleus (Vp; 10.0 +/
4.9) and in the lateral VcIII/IV (11.5 +/- 1.6). A high-intensity stimulus (1.0
mA) significantly increased the number of Fos-positive neurons in each
subdivision compared with the low-intensity stimulus (Vp 32.3 +/- 10.8; Vodm
270.3 +/- 75.3; Vidm 189.3 +/- 38.5; medial VcIII/IV 77.5 +/- 18.2; lateral
VcIII/IV 24.8 +/- 9.3; VcI/II, 2155.8 +/- 470.2). At both low- and high-intensity
stimulation, the fields where Fos-positive neurons appeared are restricted to the
dorsal or dorsomedial subdivisions of the rostral subnuclei, Vp, Vo and Vi, where
the main projectional fields of primary afferents from the intraoral structures
are found, while Fos-positive neurons were distributed in the entire VcI/II,
along the dorsomedial-ventrolateral axis of Vc, where the main projectional
fields of primary afferents from the facial skin are found. The threshold to
induce c-Fos is, however, different according to the fields. These results
suggest that nociceptive processing in the intra-oral region is mediated through
the entire length of the rostro-caudal axis of TSN, but is mediated primarily
through VcI/II in the facial region.
PMID- 10672465
TI - Effects of stimulus size and eccentricity on horizontal and vertical vergence.
AB - We measured the gain and phase of horizontal and vertical vergences of five
subjects as a function of stimulus area and position. Vergence eye movements were
recorded by the scleral search coil method as subjects observed dichoptic
displays oscillating in antiphase either from side to side or up and down with a
peak-to-peak magnitude of 0.5 degree at either 0.1 Hz or 1.0 Hz. The stimulus was
a central textured disc with diameter ranging from 0.75 degree to 65 degrees, or
a peripheral annulus with outer diameter 65 degrees and inner diameter ranging
from 5 degrees to 45 degrees. The remaining field was black. For horizontal
vergence at both stimulus frequencies, gain and the phase lag were about the same
for a 0.75 degree stimulus as for a 65 degrees central stimulus. For vertical
vergence, mean gain increased and mean phase lag decreased with increasing
diameter of the central stimulus up to approximately 20 degrees. Thus, the
stimulus integration area is much smaller for horizontal vergence than for
vertical vergence. The integration area for vertical vergence is similar to that
for cyclovergence, as revealed in a previous study. For both types of vergence,
response gains were higher and phase lags smaller at 0.1 Hz than at 1.0 Hz. Also,
gain decreased and phase lag increased with increasing occlusion of the central
region of the stimulus. Vergence gain was significantly higher for a 45 degrees
central disc than for a peripheral annulus with the same area. Thus, the central
retina has more power to evoke horizontal or vertical vergence than the same area
in the periphery. We compare the results with similar data for cyclovergence and
discuss their ecological implications.
PMID- 10672466
TI - Instructing subjects to make a voluntary response reveals the presence of two
components to the audio-vocal reflex.
AB - Previous findings have shown that subjects respond to an alteration, or shift, of
auditory feedback pitch with a change in voice fundamental frequency (F0). When
pitch shifts exceeding 500 ms in duration were presented, subjects' averaged
responses appeared to consist of both an early and a late component. The latency
of the second response was long enough to be produced voluntarily. To test the
hypothesis that there are two responses to pitch-shift stimuli and to clarify the
role of intention, subjects were instructed to change their voice F0 in the
opposite direction of the pitch-shift stimulus, in the same direction, or not to
respond at all. In a second group, subjects were tested under the above
conditions as well as under instructions to raise voice F0 or to lower F0 as
rapidly as possible upon hearing a pitch shift. Results showed that, when given
instructions to produce a voluntary response, subjects made both an early vocal
response (VR1) and a later vocal response (VR2). The second response, VR2, was
almost always made in the instructed direction, whereas VR1 was often made
incorrectly. The latency of VR1 was reduced under instructions to respond to
feedback pitch shifts by changing voice F0 in the opposite direction, compared
with that when told to ignore the pitch shifts. Latency and amplitude measures of
VR2 differed under the various experimental conditions. These results demonstrate
that there are two responses to pitch-shift stimuli. The first is relatively
automatic but may be modulated by instructions to the participant. The second
response is probably a voluntary one.
PMID- 10672467
TI - Effects of systemic 3-nitropropionic acid-induced lesions of the dorsal striatum
on cannabinoid and mu-opioid receptor binding in the basal ganglia.
AB - Systemic administration of 3-nitropropionic acid (3NPA) in experimental animals
produces bilateral striatal lesions similar to those seen in Huntington's disease
(HD) caudate and putamen. 3H[-CP55,940 binding to cannabinoid receptors in human
basal ganglia nuclei has been shown to be highly susceptible to the earliest
pathological changes in the HD brain. In this study, to assess further the
suitability of 3NPA-induced striatal lesions as a model for HD neuropathology, we
examined the effects of striatal lesions induced by the systemic administration
of 3NPA on the binding of 3H[-CP55,940 to pre- and postsynaptic cannabinoid
receptors in striatum, globus pallidus, entopeduncular nucleus and substantia
nigra pars reticulata and also the effect of 3NPA-induced striatal lesions on the
binding of 3H[-DAMGO to mu-opioid receptors in striatal striosomes. Systemic
administration of 3NPA induced bilateral and symmetrical lesions in dorsolateral
striatum. Within the lesion core, 3H[-CP55,940 and 3H[-DAMGO binding density was
reduced to background levels. Beyond the immediate borders of the central core of
the 3NPA-induced lesion, striatal binding density was not significantly different
from that measured in unlesioned rats. 3H[-CP55,940 binding in globus pallidus,
entopeduncular nucleus and substantia nigra in 3NPA-lesioned rats was
significantly reduced compared to controls, and the individual decreases were
similar for each site. However, these reductions were statistically marginal.
These data suggest that, while producing striatal lesions which bear some
similarity to those seen in HD, the consequences of 3NPA for striatopallidal and
striatonigral efferent projections do not reflect the reported neurodegenerative
changes seen in the HD brain.
PMID- 10672468
TI - Responses of vestibular nucleus neurons to tilt following chronic bilateral
removal of vestibular inputs.
AB - Recordings were made from the vestibular nuclei of decerebrate cats that had
undergone a combined bilateral labyrinthectomy and vestibular neurectomy 49-103
days previously and allowed to recover. Responses of neurons were recorded to
tilts in multiple vertical planes at frequencies ranging from 0.05 to 1 Hz and
amplitudes up to 15 degrees. Many spontaneously active neurons were present in
the vestibular nuclei; the mean firing rate of these cells was 43 +/- 5 (SEM)
spikes/s. The spontaneous firing of the neurons was irregular: the coefficient of
variation was 0.86 +/- 0.14. The firing of 27% of the neurons was modulated by
tilt. The plane of tilt that elicited the maximal response was typically within
25 degrees of pitch. The response gain was approximately 1 spikes/s/degree across
stimulus frequencies. The response phase was near stimulus position at low
frequencies, and lagged position slightly at higher frequencies (average of 35 +/
9 degrees at 0.5 Hz). The source of the inputs eliciting modulation of
vestibular nucleus activity during tilt in animals lacking vestibular inputs is
unknown, but could include receptors in the trunk or limbs. These findings show
that activation of vestibular nucleus neurons during vertical rotations is not
exclusively the result of labyrinthine inputs, and suggest that limb and trunk
inputs may play an important role in graviception and modulating vestibular
elicited reflexes.
PMID- 10672469
TI - Voluntary modification of automatic arm movements evoked by motion of a visual
target.
AB - We have investigated whether the processes underlying the visually evoked,
automatic adjustments to a reach are: (1) modifiable by the subject's intention,
and (2) available to initiate movement of a stationary arm. Unpredictable
movement of a target (80 m/s through 10 cm, left or right in a third of trials)
either evoked a mid-flight adjustment of a reaching movement or else acted as a
trigger to start an arm movement. Subjects were instructed to respond as rapidly
as possible by moving their finger either in the same or in the opposite
direction to the target. The target shift evoked an early (125-160 ms) and/or a
later (> 160 ms) class of response in the reaching arm. The early response was
highly automatic in that it could not be reversed (move opposite) by the
subjects' intention. However, the subjects' intention did influence the frequency
of occurrence and the size of this early response. The later response was totally
modifiable in that it changed direction according to the subjects' intention.
Similar classes of response were observed in stationary limbs, but the early,
more automatic response was substantially weaker than that elicited during a
reach. Two possible mechanisms are proposed to explain these results. The first
is a dual-pathway model, which assumes that the two response classes are each
generated by separate visuo-motor processes with different properties. The second
model assumes both responses are generated by a single visuo-motor mechanism that
is under the control of a higher, attentional process.
PMID- 10672470
TI - Flexibility of saccade adaptation in the monkey: different gain states for
saccades in the same direction.
AB - Saccadic accuracy, measured as the ratio of the size of a saccade to the size of
the target step that elicits it, i.e., saccade gain, can be altered by jumping
the target surreptitiously during the targeting saccade. The gain change produced
by this paradigm does not generalize or transfer to saccades of all sizes.
Instead, the amount of transfer decreases the more the tested saccade differs in
amplitude and direction from that adapted. Here, we tested the limits of this
saccade-size specificity by attempting to impose quite different gain states on
saccades in the same direction. We altered the saccadic gain by intrasaccadic
target jumps of 30% of the initial target step, either forward to produce a gain
increase or backward to produce a gain decrease. Three different conditions were
studied: (1) saccades to target steps of 20 degrees or 7 degrees were adapted in
individual sessions with backward and forward jumps, respectively; (2) saccades
to target steps of 20 degrees caused backward target jumps during the same
session in which saccades to 7 degrees target steps caused forward steps; (3) the
target jumps accompanying 20 and 7 degrees saccades were the same as in (2), but
in addition, there were intermediate-sized saccades to 13.5 degrees target steps
with no intrasaccadic target jumps. Saccadic gain adaptation was quite flexible.
In condition 2, we could simultaneously increase the gain of saccades to 7
degrees target steps while decreasing the gain of saccades to 20 degrees steps in
the same direction. Intermediate horizontal saccades to 13.5 degrees target steps
experienced gain reductions (average: 6.9%), which were not the sum of gain
changes expected from separate 20 degrees gain decreases and 7 degrees gain
increases alone, as predicted from condition 1. If adaptation at 20 degrees and 7
degrees occurred while an animal also tracked a non-adapting 13.5 degrees target
step (paradigm 3), the gain reduction of saccades to the 13.5 degrees step was
reduced considerably (3.4%). Thus, the mechanism that adapts saccade size can
support a robust gain increase for saccades of one size while simultaneously
supporting a robust gain decrease for saccades only 13 degrees larger.
Furthermore, the presence during adaptation of a non-adapted target step with a
size intermediate to the two adapting steps reestablishes a nearly normal gain
within only 6.5 degrees of a robust gain increase and decrease. These data
indicate that saccadic gain adaptation can set very different gain states for
saccades with rather similar vectors.
PMID- 10672471
TI - Electrophysiological correlates of human intrasaccadic processing.
AB - Visual discrimination performance is thought to be suppressed during saccades in
order to contribute to space constancy. However, under certain experimental
conditions, visual inhibition may not take place, suggesting a more complex
underlying mechanism. We tested the discrimination ability of 20 healthy subjects
during visually guided horizontal saccades and recorded simultaneously the evoked
brain activity from 30 channels over occipital, parietal, and temporal areas.
During the execution of saccadic eye movements, visual stimuli were presented for
30 ms. In order to prevent retinal afterimages, stimuli were followed by a visual
mask. In a control condition, the same stimuli were presented with stationary
eyes. Electro-oculogram (EOG) and electroencephalogram (EEG) signals were
recorded continuously together with information about the stimuli and the
subject's response. Evoked potentials were computed offline, and component
latency, field strength (global field power), and topography were compared
between conditions. During saccades, subjects showed only slightly reduced
discrimination performance which remained very high above the chance level; thus,
there was no evidence for strong saccadic suppression with the supra-threshold
stimuli employed. However, the cortical activation patterns exhibited large
alteration when a physically identical stimulus was presented during the eye
movement: around 130 ms latency, field strength was significantly smaller than
when stationary targets were processed, and scalp topography was also different.
These effects on evoked field distributions may be attributed to neural
interactions of an efference copy signal (linked to the oculomotor command) with
the afferent excitation following the visual stimulus.
PMID- 10672472
TI - Descending corticofugal neurons in layer 5 of rabbit S1: evidence for potent
corticocortical, but not thalamocortical, input.
AB - Extracellular recordings were obtained from descending corticofugal neurons of
layer 5 (CF-5 neurons) in primary somatosensory cortex (S1) of awake rabbits.
These cells were identified by antidromic activation via stimulation sites in
ventrobasal (VB) thalamus. Recordings were also obtained from putative GABA-ergic
interneurons (suspected inhibitory interneurons, SINs) located in the same
microelectrode penetrations, and in close proximity (+/- 300 microns) to the CF-5
neurons. In some experiments, the above populations were recorded simultaneously
with neurons in the topographically aligned VB thalamic barreloid. Each of
several experimental strategies failed to reveal evidence of monosynaptic
thalamic input to CF-5 neurons, but revealed a clear monosynaptic input to
neighboring SINs: (1) whereas CF-5 neurons responded at very long synaptic
latencies to intense electrical stimulation of VB thalamus, neighboring SINs
responded at short latencies; (2) whereas cross-correlations between CF-5 neurons
and topographically aligned VB neurons failed to show significant peaks
indicative of monosynaptic VB input, neighboring SINs did show such peaks; and
(3) whereas CF-5 neurons were unresponsive to microstimulation of topographically
aligned VB thalamic barreloids, neighboring SINs were very responsive to such
stimulation. Both CF-5 neurons and neighboring SINs responded to electrical
stimulation of the corpus callosum with a robust, short-latency synaptic
response. This finding demonstrates that CF-5 neurons are capable of vigorous,
short-latency responses to excitatory synaptic input. These data suggest
considerable specificity in the thalamocortical connectivity of subpopulations
within layer 5, and support the notion that CF-5 neurons are dominated by
corticocortical rather than thalamocortical input.
PMID- 10672473
TI - Oscillations in the premotor cortex: single-unit activity from awake, behaving
monkeys.
AB - We examined single-unit activity in the dorsal premotor cortex for evidence of
fast neuronal oscillations. Four rhesus monkeys performed a task in which
visuospatial instruction stimuli indicated the direction of forelimb movement to
be executed on each trial. After an instructed delay period of 1.5-3 s, movements
to either the right or left of a central origin were triggered by a second
visuospatial stimulus. From a database of 579 single units, 78 units (13%)
contained periodic peaks in their autocorrelation histograms (ACHs), with
oscillation frequencies typically 20-30 Hz (mean 27 Hz). An additional 26 units
(5%) had oscillatory features that were identified in joint interspike-interval
(ISI) plots. Three observations, taken together, suggest entrainment by rhythmic
drive extrinsic to these neurons: shuffling ISIs attenuated ACH peaks, indicating
a dependency on serial-order effects; oscillation frequency did not change during
either increases or decreases in firing rate; and joint ISI plots contained
features consistent with a rhythmicity interrupted by intervening discharges. In
some cells, oscillations occurred for only one of the two directions of movement.
During the delay period, such directional selectivity was observed in 37 units
(60% of delay-period oscillators). For at least 17 of these units, we could
exclude the possibility that oscillatory directional selectivity resulted from
the difficulty in detecting oscillations due to low discharge rates (for one of
the two movement directions). Directional selectivity in fast oscillations shows
that they can reflect specific aspects of an intended action.
PMID- 10672474
TI - Transfer of tritiated water, tyrosine, and propanol from the nasal cavity to
cranial arterial blood in rats.
AB - Respiration cools the nasal vein blood. This may, via counter current transfer in
the cavernous sinus/carotid artery complex, cool the brain arterial blood and,
therefore, decrease the brain temperature during heat stress. We investigated the
possible local transfer of substances from the nasal cavities to the brain via a
similar transfer between nasal venous blood and brain arterial blood. Tritiated
water (TW), 3H-tyrosine (T) and 14C-propanol (P) were infused into the nasal
cavity of anesthetized rats that had two catheters inserted into the same,
occluded carotid artery, one pointing towards the head, the other towards the
heart. Continuous, parallel blood samples were collected throughout 30-s periods
for 10 min, and the radioactivity measured in the separated plasma. After nasal
application of TW, the radioactivity increased in the head arterial plasma
samples compared with the parallel heart samples. When recirculation to the
general circulation was diminished, a larger and significant difference was found
for all three substances during the last 5 min of the collection period. No
difference between the parallel samples was observed after intravenous
administration of the three substances. Absorption of all three substances from
the nasal cavity was rapid and high. The results indicate that local transfer
takes place between the venous and arterial blood in the head, probably in the
area of the cavernous sinus-carotid artery complex, which in rat and man lacks a
Rete Mirabile. The local transfer raises the possibility of treating brain
diseases in man locally through nasal application of drugs.
PMID- 10672475
TI - Striate cortex in humans demonstrates the relationship between activation and
variations in visual form.
AB - Electrophysiologic and functional imaging studies have shown that the visual
cortex produces differential responses to the presence or absence of structure
within visual textures. To further define and characterize regions involved in
the analysis of form, functional magnetic resonance imaging (fMRI) was used to
detect changes in activation during the viewing of four levels of isodipole
textures. The texture levels systematically differed in the density of visual
features such as extended contours and blocks of solid color present within the
images. A linear relationship between activation level and density of structure
was observed in the striate cortex of human subjects. This finding suggests that
a special subpopulation of striate cortical neurons participates in the ability
to extract and process structural continuity within visual stimuli.
PMID- 10672476
TI - Activity in deep intermediate layer collicular neurons during interrupted
saccades.
AB - The activity of neurons located in the deep intermediate and adjacent deep layers
(hereafter called just deep intermediate layer neurons) of the superior
colliculus (SC) in monkeys was recorded during saccades interrupted by electrical
stimulation of the brainstem omnipause neuron (OPN) region. The goal of the
experiment was to determine if these neurons maintained their discharge during
the saccadic interruption, and thus, could potentially provide a memory trace for
the intended movement which ends accurately on target in spite of the
perturbation. The collicular neurons recorded in the present study were located
in the rostral three-fifths of the colliculus. Most of these cells tended to show
considerable presaccadic activity during a delayed saccade paradigm, and,
therefore, probably overlap with the population of SC cells called buildup
neurons or prelude bursters in previous studies. The effect of electrical
stimulation in the OPN region (which interrupted ongoing saccades) on the
discharge of these neurons was measured by computing the percentage reduction in
a cell's activity compared to that present during non-interrupted saccades.
During saccade interruption about 70% of deep intermediate layer neurons
experienced a major reduction (30% or greater) in their activity, but discharge
recovered quickly after the termination of the stimulation as the eyes resumed
their movement to finish the saccade on the target. Therefore, the pattern of
activity recorded in most of the deep intermediate layer neurons during
interrupted saccades qualitatively resembled that previously reported for the
saccade-related burst neurons which tend to be located more dorsally in the
intermediate layer. In contrast, some of our cells (30%) showed little or no
perturbation in their activity caused by the saccade interrupting stimulation.
Because all the more dorsally located burst neurons and the majority of our deep
intermediate layer neurons show a total or major suppression in their discharge
during interrupted saccades, it seems unlikely that the colliculus by itself
could maintain an accurate memory of the desired saccadic goal or the remaining
dynamic motor error required to account for the accuracy of the resumed movement
which occurs following the interruption. However, it remains possible that the
smaller proportion of our neurons whose activity was not perturbed during
interrupted movements could play a role in the mechanisms underlying saccade
accuracy in the interrupted saccade paradigm. Interrupted saccades have longer
durations than normal saccades to the same target. Therefore, we investigated
whether the discharge of our deeper collicular cells was also necessarily
prolonged during interrupted saccades, and, if so, how the prolongation compared
to the prolongation of the saccade. Sixty percent of our sample neurons showed a
prolongation in discharge that was approximately the same as the prolongation in
saccade duration (difference < 15 ms in magnitude). The, observation that
temporal discharge in our neurons was perturbed to roughly match saccadic
temporal perturbation suggests that dynamic feedback about ongoing saccadic
motion is provided to the colliculus, but does not necessarily imply that this
structure is the site responsible for the computation of dynamic motor error.
PMID- 10672477
TI - Functional reorganisation of the corticomotor projection to the hand in skilled
racquet players.
AB - While it is known that relatively rapid changes in functional representation may
occur in the human sensorimotor cortex in short-term motor-learning studies,
there have been few studies of changes in organisation of the corticomotor system
associated with the long-term acquisition of motor skills. In the present study,
we have used transcranial magnetic stimulation (TMS) to investigate the
corticomotor projection to the hand in a group of elite racquet players, who have
developed and maintained a high level of skill over a period of many years, and
have compared the findings with those in a group of social players and a group of
non-playing control subjects. Increased motor-evoked-potential (MEP) amplitudes
and shifts in the cortical motor maps for the playing hand were found in all of
the elite players and cortical motor thresholds were reduced in some players,
whereas in the social players all parameters were within the normal range. The
findings in the elite players are interpreted as being indications of a process
of functional reorganisation with the motor cortex or corticomotor pathway that
are associated with the acquisition and retention of complex motor skills.
PMID- 10672478
TI - Cooling of the brain through oxygen flushing of the nasal cavities in intubated
rats: an alternative model for treatment of brain injury.
AB - Local cooling of the brain by respiration has been found in several animal
species with a rete mirabile in the carotid artery/cavernous sinus complex. The
present experiment was made to investigate whether a similar cooling could be
found in the rat, which does not have a rete. Eleven rats were anesthetized and
intubated. Three thermoprobes were inserted into the brain (two probes) and
rectum, and the temperatures measured continuously. The nasal cavities were
flushed with oxygen (250-1000 ml/min) during 15-min periods, interrupted by 15
min control periods. The mean brain temperature decreased by 0.43 +/- 0.03 degree
C (n = 86, P < 0.005) with individual values up to 1.11 degrees C during the
flushing periods. The decrease was oxygen-flow dependent, but not correlated to
the rectal temperature. It is concluded that even an animal species without a
rete mirabile is able to decrease the brain temperature through nasal cooling.
The cooling was probably connected to the blood flow. If the results can be
extrapolated to man (no rete mirabile), brain temperature can be decreased by
nasal flushing with air or oxygen in intubated patients with hyperthermia. We
also suggest that this simple treatment will reduce the infarct volume after head
injury, trauma, or brain ischemia.
PMID- 10672479
TI - Intentional on-line adaptation of stride length in human walking.
AB - The intentional control of stride length is a fundamental basis for the
adaptation of the stride to environmental constraints (obstacle avoidance, for
example). Controlling the propulsive forces during the stance and/or controlling
the pendular movement of the oscillating leg constitute the two potential and non
exclusive mechanisms underlying intentional stride length modulation. The present
experiment was conducted in order to determine if these two mechanisms contribute
to voluntary length modulation and, if so, how they cooperate according to
whether the subject has to lengthen or shorten a stride and how these mechanisms
are implemented at the neuromuscular level. Subjects had to produce a temporarily
modulated stride of the same length, but originating from two different initial
steady-states: one from shorter stride length and one from longer stride length.
We found that the shortening was essentially realized by a swing-duration
decrease (an increased activity in the hip extensor--biceps femoris--during the
swing of the ipsilaterally shortened stride stopped the pendular leg movement
earlier). The lengthening was realized by two mechanisms: (1) an increase in the
propulsive forces (via an increased activity of the ankle extensor muscles-
soleus--and the hip extensors--biceps femoris--from the stance of the
ipsilaterally modulated stride, which was prolonged during the following stance
of the contralateral leg), and (2) an increase in swing duration on the
ipsilateral leg (an increased activity in hip and ankle flexors--rectus femoris
and tibialis anterior--maintained the ipsilateral leg in flexion during the
lengthened swing so that the foot landed later). In this experiment, the subjects
were faced with a spatial constraint of the same magnitude in the direction of
stride lengthening and stride shortening. However, under these conditions,
subjects used a different balance between swing control (that directly modifies
the foot trajectory without affecting the trajectory of the head-arm-trunk
system) and/or the control of propulsive forces (that indirectly influences foot
trajectory by modifying the trajectory of the head-arm-trunk system). In the
first case, this concerns a voluntary control of gesture produced by the legs and
usually implicated in the locomotor pointing; in the second case, this concerns a
voluntary control of propulsive forces.
PMID- 10672480
TI - Estimating the components of the gap effect.
AB - The gap effect refers to the finding that saccadic latencies are typically
reduced when a fixation point is removed prior to the appearance of a peripheral
target. This reduction in saccadic reaction time (SacRT) is thought to be due to
a general warning effect and an oculomotor specific fixation offset that occur
when the fixation point is removed. In order to estimate the contribution of each
of these effects to the overall gap effect, this paper introduces a new
manipulation, the partial-gap trial, where the fixation point undergoes a change
in size prior to the presentation of the target. The partial-gap trial is
presumed to provide the visual warning effect of the fixation offset (i.e.
similar to that in a gap trial) but does not provide the fixation offset effect
(FOE). When the fixation point was abruptly reduced in size before the
presentation of the target, the estimated decrease in SacRT due to the visual
warning effect was 5-7% and did not differ in the presence or absence of an
auditory warning signal. It was found that auditory warning effect and the FOE
interacted in reducing SacRTs. Additionally, when the fixation point was abruptly
increased in size before the presentation of the target, SacRTs were slower than
when the fixation point did not change in size and remained present for the
entire trial (i.e. an overlap trial). We conclude that this new partial-gap
paradigm is a useful method for researchers wishing to separately examine FOE and
visual warning effects.
PMID- 10672481
TI - Inhibition of return in saccadic eye movements.
AB - Inhibition of return (IOR) is a phenomenon in which responses generated to
targets at previously attended locations are delayed. It has been suggested that
IOR affords a mechanism for optimizing the inspection of novel locations and that
it is generated by oculomotor reflexes mediated by the superior colliculus. In
this investigation, we measured the effects of IOR on the metrics of saccadic eye
movements made to novel and previously attended locations. Saccades made to cued
target locations, as well as to other targets within the same hemifield, had
longer latencies than saccades made towards the novel, uncued hemifield. We
further found that the amplitudes of saccades towards the cued hemifield were
more hypometric, but only when the amplitude could not be pre-programmed. These
results provide evidence that IOR influences spatial, as well as temporal,
parameters of saccadic eye movements and suggest that the exogenous orienting of
attention, in addition to influencing target detection, also influences
oculomotor programming.
PMID- 10672482
TI - Visual and haptic feedback in the control of force.
AB - The ability to control index finger and elbow flexion forces was measured while
subjects used either haptic feedback or both haptic and visual feedback to
control the forces exerted. Over a 120-s time period subjects were able to
control the finger forces ranging from 2 to 6 N to within 1 N using only haptic
feedback, and elbow flexion forces to within 4.5 N over a force range of 10-30 N.
At the same force amplitude there was no significant difference between the two
muscle groups in the precision or accuracy with which the force could be
controlled, suggesting that there is not a proximal to distal gradient in force
control as has been found for the control of limb movement and position.
PMID- 10672483
TI - The Judd illusion: evidence for two visual streams or two experimental
conditions?
AB - In the Judd illusion, observers inaccurately bisect the shaft located between two
arrowheads pointing in the same direction. The magnitude of error is greater when
verbal judgements are compared to action based responses (reaching out and
grasping the centre of the bar). This difference has been attributed to the
presence of two visual streams within cortical processing. In contrast, we
provide evidence that the improved accuracy in the reaching condition may be due
to occlusion of the illusory background during the transport phase of the
movement. We suggest that caution is required when interpreting performance
differences between two conditions that are not strictly equivalent.
PMID- 10672484
TI - [Different clinical courses in borreliosis are caused by different pathogens].
PMID- 10672485
TI - Occupational and environmental medicine in Sweden.
AB - Great changes have taken place in the fields of occupational and environmental
medicine in Sweden during the past decade. Unemployment, work stress, and indoor
climate problems have become increasingly common. Chemical exposures in industry
and serious work accidents have continued to decrease. State subsidies to
occupational health services have been withdrawn and the legislation concerning,
for example, occupational diseases has been changed in order to decrease state
expenditure. Research has focused on, for instance, ergonomic and psycho-social
factors, electromagnetic fields and exposures causing allergy. There is a growing
awareness of the need for more emphasis on prevention, which should act in favour
of both hospital-based occupational and environmental medicine and the
occupational health services sector.
PMID- 10672486
TI - Environmental epidemiology--strengths and weaknesses.
PMID- 10672487
TI - Possible effects of environmental cadmium exposure on kidney function in the
Japanese general population.
AB - OBJECTIVES: To examine whether the current level of environmental exposure to
cadmium (Cd) is associated with kidney dysfunction among general populations in
Japan. METHODS: A nationwide survey was conducted in Japan from 1991 to 1997 at
30 survey sites (with no known environmental heavy metal pollution), by the
collection of 24-h food-duplicate samples, peripheral blood specimens and morning
spot urine samples. In practice, 607 non-smoking adult women provided these
samples. After being wet-ashed, the samples were analyzed for Cd in food
duplicates (Cd-F), in blood (Cd-B) and urine (Cd-U) by inductively-coupled plasma
mass spectrometry (ICP-MS). Urine samples were also analyzed for alpha 1
microglobulin (alpha 1-MG), beta 2-microglobulin (beta 2-MG) and retinol-binding
protein (RBP), creatinine (cr) and specific gravity. Possible tubular dysfunction
in association with Cd exposure was examined by simple, multiple and logistic
regression analyses, and comparison among three different Cd-dose groups. To
minimize the confounding effects of aging, 367 women from 41 to 60 years old were
selected and subjected to the same statistical analyses. RESULTS: The analysis of
a whole population of 607 women showed that alpha 1-MG and possibly beta 2-MG
increased as a function of Cd-F, Cd-B and Cd-U. When the analysis was repeated
with the selected population of 367 women aged 41-60, the Cd dose-dependent
changes in alpha 1-MG and beta 2-MG became less evident. The distribution of the
selected population with alpha 1-MG above two low cut-off values of > 4.9 and >
8.4 mg/g cr or with beta 2-MG above the lowest cut-off value of > 400
micrograms/g cr, was biased toward the group with higher Cd-Ucr, but such bias
was not significant for both alpha 1-MG and beta 2-MG when higher cut-off values
were employed. No bias was detected with RBP. Logistic regression analysis with
alpha 1-MG, beta 2-MG and RBP (with cut-off values given above) in combination
with age, Cd-F, Cd-B and Cd-Ucr gave essentially the same results. CONCLUSIONS:
The evidence for kidney dysfunction was of borderline significance in the present
study population for which geometric mean Cd-F, Cd-B and Cd-U were 24.7
micrograms/day, 1.76 micrograms/l, and 3.94 micrograms/g cr, respectively. The
findings might suggest at the same time that the safety margin is small for the
Japanese general population regarding environmental Cd exposure.
PMID- 10672488
TI - Cadmium exposure of women in general populations in Japan during 1991-1997
compared with 1977-1981.
AB - OBJECTIVES: The Japanese people are known to have high environmental exposure to
cadmium (Cd). The present survey was initiated to elucidate possible changes in
the intensity of Cd exposure to the population by comparison of the present
exposure level with the situation some 15 years ago. METHODS: During 1991-1997,
24-h food-duplicate samples, peripheral blood specimens and morning spot urine
samples were collected from 588 non smoking women from 27 survey sites in six
regions, where food-duplicate and blood samples had also been obtained during
1977-1981 from 399 women. The samples were wet-ashed (after homogenization in the
case of food-duplicates), and Cd in the wet-ashed samples was analyzed by
inductively-coupled plasma mass spectrometry for Cd intake via foods (Cd-F), Cd
concentration in blood (Cd-B) and Cd concentration in urine (Cd-U). The Cd-F and
Cd-B were compared with the Cd-F and Cd-B obtained at the same sites in the 1977
1981 survey. RESULTS: The exposure levels during 1991-1997 were such that Cd-F,
Cd-B and Cd-Ucr (Cd-U after correction for creatinine concentration) were 25.5
micrograms/day, 1.90 micrograms/l and 4.39 micrograms/g creatinine. Comparison
with the 1977-1981 survey results (i.e., 37.5 micrograms/day for Cd-F and 3.47
micrograms/l for Cd-B) showed that there were significant reductions (by 32 and
45%) in both parameters respectively during the last 15 years. The dietary route
was an almost exclusive (i.e., 99% of the sum of dietary and respiratory uptake)
route of Cd uptake, of which Cd in rice (11.7 micrograms/day) contributed about
40% of the total dietary intake. When compared among survey sites, inter-site
variation in dietary Cd intake was primarily due to differences in the intake
through boiled rice. Despite the recent reduction in Cd exposure, the current
exposure level for Japanese people is still higher than the levels among other
rice-dependent populations in Asia as well as in other parts of the world.
Comparison was made between the present findings in general populations and
observations among known Cd-pollution cases in Japan. CONCLUSIONS: Dietary uptake
is an almost exclusive route of Cd exposure in the general Japanese population.
Boiled rice is a strong determinant of variation in dietary Cd intake. Whereas
there was a substantial reduction in Cd exposure among Japanese populations in
the last 15 years, the current level is still high when compared internationally.
PMID- 10672489
TI - Lumbar spine loads during education and training with self-contained breathing
apparatus.
AB - OBJECTIVE: German fire fighters often complain of lumbar back pain after training
with a self-contained breathing apparatus while using a device called
'Schlaghammer' (SH). We investigated whether this training produces an excessive
load on the lumbar spine. METHOD: We developed a model to estimate the load on
the lumbar spine using a vector model similar to Jager et al.'s model. The force
at the SH's cable was recorded on-line, and the position of each subject was
registered with synchronized series of photos. The influence of the different
parameters was calculated by varying these data (+/- 10%) and computing the
model. RESULTS: There is no dangerous load for healthy persons using a correct
technique. Improper technique, however, caused by exhaustion or ignorance, can
result in high peaks of lumbar spine load. CONCLUSIONS: The lumbar spine loads
involved are acceptable if the exercise is performed with a straight back without
bending of the lumbar spine and without sudden acceleration. The direction of the
pull should be towards the lumbar spine.
PMID- 10672490
TI - The mechanism of a human reaction to vibration stress by palmar sweating in
relation to autonomic nerve tone.
AB - OBJECTIVES: To clarify the mechanism of a human reaction to vibration stress by
palmar sweating in relation to the autonomic nerve tone. METHODS: The autonomic
nerve tone was divided into four types by using digital
photoelectroplethysmography (PTG) with auditory stimuli: normal (N),
hyperreactive (I and D), and hyporeactive (P) types. Palmar sweating and digital
PTG were simultaneously measured on the right palm and middle finger,
respectively, in 20 healthy men. The left hand gripping the handle with a grasp
strength of 49 N was exposed to vibration at a frequency of 125 Hz and
acceleration magnitudes of 0 m/s2 (as a control), 30 m/s2, or 50 m/s2 for 3 min.
The volume of palmar sweating was recorded before, during, and 30 min after
vibration load. Three kinds of drugs related to the autonomic nervous system were
orally administered to the subjects. Then 80 min after administration, the
experiments were repeated. RESULTS: Of 20 subjects, 17 showed normal autonomic
nerve tone (N type), and 3 hyperreactive (I type). The palmar sweating reaction
to vibration in I-type subjects was greater and lasted longer than that in N-type
subjects. Vibration with an acceleration of 50 m/s2 produced the greatest
reaction which was about 7 times larger than that at 0 m/s2 and 2.5 times that at
30 m/s2 (P < 0.01). Sulpiride decreased palmar sweating during vibration, while
prazosin and scopolamine inhibited it. CONCLUSIONS: The palmar sweating reaction
to vibration stress was related to the background level of the autonomic nerve
tone. The sweating volume was in direct proportion to the acceleration magnitude
of vibration. The reaction of palmar sweating to vibration stress may be mediated
through both the adrenergic and cholinergic fibers of the autonomic nervous
system.
PMID- 10672491
TI - Questionnaire surveys on health and working conditions: development of an
instrument for risk assessment in companies.
AB - Periodic Occupational Health Surveys (POHS) are frequently used by occupational
health and safety services in the Netherlands as a risk assessment instrument.
These surveys include a questionnaire on work and health. Systematic attention is
paid in this questionnaire to a broad range of working conditions and health
complaints. In this article a method is presented to identify and evaluate work
risks and health problems in groups of workers. Working conditions and health in
any given company or department are assessed by comparing questionnaire data from
its worker populations with data from one or more reference populations.
Significant differences are interpreted as signals for both adverse working
conditions and health problems. Considerations and choices with regard to the
technical, operational and strategic quality of the method are elucidated.
Probabilities of alpha- and beta-errors, choice of significance levels, and
selection of reference populations are dealt with. Finally, a way of presentation
of the results is shown. The method is considered to be part of a broader
approach toward risk assessment. We recommend the combined use of questionnaire
results and other available information, such as workplace surveys and sickness
absence data. Questionnaires about work and health can be seen as one step in a
multi-phase design: like in many diagnostic processes, the latter phases can
enhance the precision of previous results. Recommendations are made for
validating and evaluating this instrument.
PMID- 10672492
TI - Evaluation of half-mask respirator protection in styrene-exposed workers.
AB - OBJECTIVE: The protection afforded by respirators to styrene (St)-exposed workers
varies considerably. Our objective was to study the effective 'in the field'
reduction in St exposure obtained by negative-pressure half-mask respirators worn
by a group of fiberglass-reinforced plastics (FRP) workers. Protection was
evaluated by measuring the reduction in urinary St (StU) excretion. METHODS:
Seven FRP workers not using respiratory protection devices were studied for a
week. External exposure to St was evaluated by personal passive sampling, and the
internal dose by StU measurement. Then workers were asked to use a half-mask
respirator for a week for the entire morning half-shift, and St exposure and
internal dose were re-assessed. RESULTS: Mean environmental levels of St during
the morning half-shift were 230-280 mg/m3, i.e., about three times the current
limit proposed by ACGIH; the difference among days was not significant. Using
respirators was accompanied by a large inter-individual and also intra-individual
variability: the estimated reduction of StU values ranged from 30% to 90% (mean
60%). Mean StU values increased by 50% from Monday to Friday, while environmental
St concentrations remained steady. Furthermore, the proportion of workers
exceeding the biological equivalent exposure limit (BEEL) was 14% on Monday,
double (33%) on Thursday, and triple (43%) on Friday. These data suggest a
decrease of protection during the week. CONCLUSIONS: The protection afforded by
negative-pressure half-mask respirators varies widely, which stresses the need to
assess the effective reduction of exposure whenever these devices are introduced
for St-exposed workers. If respirators are to be re-used for several days, their
performance must be evaluated during the last shift of use. Measurement of
urinary excretion of unmodified St proved a useful tool for the evaluation of
respirator effectiveness in exposed workers.
PMID- 10672493
TI - Aluminium dust-induced lung disease in the pyro-powder-producing industry:
detection by high-resolution computed tomography.
AB - OBJECTIVE: The aim of this case study was to investigate the suitability of high
resolution computed tomography (HRCT) for detecting early stages of lung fibrosis
induced by aluminium (Al) dust. METHODS: A 40-year-old worker was studied who had
worked as a stamper for 14 years in a plant producing aluminium powder and had
been exposed to high levels of aluminium dust during this time. The investigation
included the collection of general data on health and details on occupational
history, immunological tests, a physical examination, lung function analysis,
biological monitoring of Al in plasma and urine, chest X-rays and HRCT. RESULTS:
For many years the man has suffered from an exercise-induced shortness of breath.
Lung function analysis revealed a reduction of the vital capacity to 57.5% of the
predicted value. The Al concentration in plasma was 41.0 micrograms/l (upper
reference value 10 micrograms/l) and in urine 407.4 micrograms/l upper reference
value 15 micrograms/l, biological tolerance (BAT) value 200 micrograms/l[ at the
time of diagnosis. Chest X-ray showed unspecific changes. HRCT findings were
characterised by small, centrilobular, nodular opacities and slightly thickened
interlobular septae. Exposure to other fibrotic agents could be excluded.
CONCLUSIONS: HRCT was more sensitive than chest X-rays for detecting this early
stage of Al-dust-induced lung disease. The suitability of HRCT in the
surveillance of workers highly exposed to aluminium powder should be evaluated in
further studies. Biological monitoring can be used to define workers at high
risk.
PMID- 10672494
TI - Urinary nickel as bioindicator of workers' Ni exposure in a galvanizing plant in
Brazil.
AB - OBJECTIVES: We measured urinary nickel (U-Ni) in ten workers (97 samples) from a
galvanizing plant that uses nickel sulfate, and in ten control subjects (55
samples) to examine the association between occupational exposure to airborne Ni
and Ni absorption. METHODS: Samples from the exposed group were taken before and
after the work shift on 5 successive workdays. At the same time airborne Ni (A
Ni) was measured using personal samplers. Ni levels in biological material and in
the airborne were determined by a graphite furnace atomic absorption spectrometry
validated method. In the control group the urine samples were collected twice a
day, in the before and after the work shift, on 3 successive days. RESULTS: Ni
exposure low to moderate was detected in all the examined places in the plant,
the airborne levels varying between 2.8 and 116.7 micrograms/m3 and the urine
levels, from samples taken postshift, between 4.5 and 43.2 micrograms/g
creatinine (mean 14.7 micrograms/g creatinine). Significant differences in U-Ni
creatinine were seen between the exposed and control groups (Student's t test, P
< or = 0.01). A significant correlation between U-Ni and A-Ni (r = 0.96; P < or =
0.001) was detected. No statistical difference was observed in U-Ni collected
from exposed workers in the 5 successive days, but significant difference was
observed between pre- and postshift samples. CONCLUSIONS: Urinary nickel may be
used as a reliable internal dose bioindicator in biological monitoring of workers
exposed to Ni sulfate in galvanizing plants regardless of the day of the workweek
on which the samples are collected.
PMID- 10672495
TI - Ribosomal proteins in cell proliferation and apoptosis.
AB - Ribosomal proteins have the complex task of coordinating protein biosynthesis to
maintain cell homeostasis and survival. Recent evidence suggests that a number of
ribosomal proteins have secondary functions independent of their involvement in
protein biosynthesis. A number of these proteins function as cell proliferation
regulators and in some instances as inducers of cell death. Specifically,
expression of human ribosomal protein L13a has been shown to induce apoptosis,
presumably by arresting cell growth in the G2/M phase of the cell cycle. In
addition, inhibition of expression of L13a induces apoptosis in target cells,
suggesting that this protein is necessary for cell survival. Similar results have
been obtained in the yeast Saccharomyces cerevisiae, where inactivation of the
yeast homologues of L13a, rp22 and rp23, by homologous recombination results in
severe growth retardation and death. In addition, a closely related ribosomal
protein, L7, arrests cells in G1 and also induces apoptosis. Thus, it appears
that a group of ribosomal proteins may function as cell cycle checkpoints and
compose a new family of cell proliferation regulators.
PMID- 10672496
TI - The immunomodulatory role of CD4-positive cytotoxic T-lymphocytes in health and
disease.
AB - Among the CD4-positive (CD4+) T-lymphocytes a population exists which expresses
cytolytic activity. These 'killer' cells belong to the T helper type 1 (Th1)
subset and if activated, express Fas-ligand (FasL) which induces apoptosis in Fas
positive target cells. The major targets of these CD4+ cytotoxic T-lymphocytes
(CTL) are cells of the immune system, such as T, B cells and macrophages which
express Fas upon activation. Thus, CD4+ CTL play a major immunoregulatory part
through the elimination of activated myeloid and lymphoid cells during and upon
completion of an immune response. In certain diseases, such as in HIV-infection
and some autoimmune disorders, the functional activity of CD4+ CTL is disturbed
preferentially at the level of FasL-Fas interaction, further emphasizing their
important immunoregulatory role. Furthermore, Fas-ligand expressing tumors can
evade the attack of Fas-positive CD4+ CTL and other effector cells, thereby
giving them an opportunity to expand.
PMID- 10672497
TI - Apoptosis of murine neonatal T cells.
AB - Recent evidence supports the idea that T cells in neonatal animals are
developmentally mature in their capacity to mount protective helper and cytotoxic
responses. Nonetheless, neonates fall prey to infections which have little effect
on adults and they often fail to mount mature responses to environmental,
experimental, or vaccine antigens. To reconcile these observations, it may be
important to consider the potential role of apoptosis in neonatal immune
responses. In adults, apoptosis is well established as a centrally important
process in the homeostasis of cellular immune responses. Activated T cells
deprived of IL-2 undergo cytokine withdrawal-induced apoptosis. Previously
activated T cells can also be triggered by secondary stimulation to undergo
activation induced apoptosis. This review summarizes our current state of
knowledge of apoptosis of murine neonatal T cells and discusses the possible
impact(s) of this apoptosis on neonatal immune responses in vivo.
PMID- 10672498
TI - Molecular and cellular mechanisms regulating T and B cell apoptosis through
Fas/FasL interaction.
AB - Fas (CD95) and Fas ligand (FasL) are a receptor/ligand pair critically involved
in lymphocyte homeostasis and peripheral tolerance such that genetic defect in
either Fas or FasL results in an autoimmune lymphoproliferative syndrome. Fas is
a type I transmembrane protein and a member of the tumor necrosis factor receptor
(TNFR) family whereas FasL is a type II transmembrane protein and a member of TNF
family. Binding of Fas by FasL induces apoptosis of the Fas-expressing cells. In
the past few years, Fas/FasL interaction has been connected to a series of
important phenomena previously viewed as independent immune processes. The
activation-induced T cell death (AICD) and the FasL-mediated cytotoxicity by
activated T cells are two critical mechanisms that can account for most of these
phenomena. It is in the context of the two mechanisms that we discuss in this
review the molecular and cellular events that occur during T/T and T/B
interactions that account for the down-regulation of the immune response. We have
also discussed recent advances in the areas of FasL gene regulation, lymphokine
regulation of AICD, and regulation of B cell susceptibility to FasL.
Investigation in these areas should help elucidate the role of Fas/FasL in the
complex network of regulatory mechanisms that control immune response and
autoimmunity.
PMID- 10672499
TI - Macrophage suppression of T cell activation: a potential mechanism of peripheral
tolerance.
AB - The mechanisms of induction and maintenance of tolerance in self-reactive T cells
in the periphery are poorly understood. Current models assume that successful T
cell activation only occurs if ligation of the T cell receptor (signal 1) by
antigen presenting cells (APCs) is accompanied by a costimulatory signal (signal
2), and that signal 1 in the absence of signal 2 is either ignored or is
tolerizing. However, there is also evidence for the existence of macrophages (M
phi) capable of suppressing T cell activation both in vitro and in vivo. The
possibility of a more actively induced tolerance exists, in which the M phi
itself responds to T cell-mediated signals in a tolerogenic fashion. This would
help to resolve the paradox that tissue M phi, which act as scavengers of self
antigen, can also act as professional APCs. The ability of tissue macrophages to
actively suppress T cells would further underscore the importance of the innate
immune system in regulating adaptive immune responses.
PMID- 10672500
TI - Involvement of Fas-Fas ligand interactions in graft rejection.
AB - The Fas/Fas ligand (FasL) pathway has been shown to be important in T lymphocyte
mediated cell death and is a key peripheral immunoregulatory mechanism that
limits expansion of antigen-activated lymphocytes. The expression of Fas by
commonly transplanted organs such as the heart, lung, kidney, and liver suggests
that these tissues may be targets of FasL-expressing allospecific cytotoxic T
lymphocytes. In this review the current literature examining the Fas/FasL system
as a potential cellular effector pathway in tissue injury is discussed. In
addition to a deleterious role in destruction of graft tissue, Fas/FasL
interactions may have a beneficial role in transplantation. Recent studies
suggest that modulation of FasL in target tissue leads to deletion, via
apoptosis, of graft infiltrating lymphoid cells. However, an equally compelling
series of reports indicate that overexpression of FasL can lead to a heightened
immune response. These data are reviewed in the context of strategies to achieve
long term allograft survival.
PMID- 10672501
TI - Apoptosis and CD95 ligand in immune privileged sites.
PMID- 10672502
TI - Apoptosis in human autoimmune diseases.
AB - The description of apoptosis or programmed cell death nearly thirty years ago did
not initially stimulate a great deal of interest. However, the ways cells die is
clearly an essential part of biological homeostasis and well worth of study in
its own right as the enormous literature on the subject in the past 15 years
confirms. In the past decade new avenues of apoptosis research have opened up as
the relationship between this form of cell death and autoimmune disease has come
under increasing scrutiny. Although most research to date has been in animal
study models, there are a variety of studies which have begun to explore links
between apoptosis and a wider range of human autoimmune conditions. In this
review we analyse briefly the background to what is known about apoptosis and
focus on the increasing likelihood that abnormalities in apoptosis are
contributory factors in the development of human autoimmunity.
PMID- 10672503
TI - When immunization leads to autoimmunity: chronic inflammation as a result of
thymic and mucosal dysregulation in IL-2 knock-out mice.
PMID- 10672504
TI - Physician-hospital partnerships: incentive alignment through shared governance
within a performance improvement structure.
AB - BACKGROUND: Producing accessible, appropriate, and accountable medical care that
improves the health of the populations served requires collaborative physician
organization relationships within which performance measurement across the
continuum of care occurs. Governance and shared responsibility for performance
improvement (PI) through organizational structure and process have proven to be
particularly complex challenges. REDESIGN OF THE PI SYSTEM: The Health Alliance
of Central New York, based in Syracuse, New York, which consists in part of
Crouse Hospital; ambulatory medical care sites and physicians; a physician
organization, a physician-hospital organization, and an independent practice
association; in February 1997 established a plan for a redesign of the PI system.
IMPLEMENTING THE MODEL: In April 1998 the development of joint performance
indicators, the Family of Measures, was undertaken. Recommendations for
improvements necessary to correct process failures are referred to the medical
staff executive committee and/or the appropriate coordinating committee, which
then charges the appropriate service-line PI Council(s) with the responsibility
for making those improvements. DISCUSSION: Systemwide PI with collaborative
decision making by process stakeholders has been a major cultural transition
requiring a degree of organizational readiness. Support of the most senior levels
of management is critical. Institutional silos do not support shared,
participatory decision making and cannot be overcome without strong support from
senior management and in many cases the direct support and involvement of the
CEO. Integrating information systems represents a considerable challenge: to find
hardware and software that will interface properly to produce desired results, to
successfully interface computer support personnel into the PI process, and to
ensure the commitment to the financial resources to meet the information system
requirements. In addition, meaningful and material reengineering requires
substantial physician input. Simply reducing length of stay or cost per case is
not an outcome that is by and large a strong motivator for physicians. Projects
must have meaning at the level of the individual physician to raise interest and
create buy-in. Enduring success will be achieved only through achievement of
material and salient improvements (for both physicians and the institution) in
combination with careful alignment of physician and institutional incentives.
PMID- 10672505
TI - Continuous self-improvement: systems thinking in a personal context.
AB - BACKGROUND: Continuous quality improvement (CQI) thinking and tools have broad
applicability to improving people's lives--in continuous self-improvement (CSI).
Examples include weight loss, weight gain, increasing exercise time, and
improving relationship with spouse. In addition, change agents, who support and
facilitate organizational efforts, can use CSI to help employees understand steps
in CQI. A STEP-BY-STEP APPROACH: Team members should be involved in both the
definition of the problem and the search for the solution. How do everyday
processes and routines affect the habit that needs to change? What are the
precursors of the event? Clients list possible solutions, prioritize them, and
pilot test the items selected. One needs to change the daily routines until the
desired behavior is accomplished habitually and with little external decision.
DISCUSSION: CSI is successful because of its emphasis on habits embedded in
personal processes. CSI organizes support from process owners, buddies, and
coaches, and encourages regular measurement, multiple small improvement cycles,
and public reporting.
PMID- 10672506
TI - Does this patient need to be evaluated today? Designing a guideline-driven triage
process to determine the timing of care for adults with respiratory infection
symptoms.
AB - BACKGROUND: Physicians and nurses often make judgments about the urgency with
which patients require evaluation, yet few explicit process-of-care criteria are
available to guide these decisions. Using a multidisciplinary expert physician
panel and explicit, quantitative group judgment methods, standardized, clinically
detailed deferred care criteria were developed to guide emergency department and
ambulatory care triage decisions for same-day versus deferred care for patients
with respiratory infection symptoms. METHODS: Using a modified Delphi process, an
eight-member multidisciplinary expert physician panel rated the safety of
deferred care for standardized clinical scenarios. The ratings were converted
into explicit criteria and then compared with usual implicit judgment in terms of
nurse triage times. RESULTS: The panel achieved 100% consensus on 36 critical
clinical factors, each of which precludes deferring care for a patient with
respiratory infection symptoms. Based on combinations of 12 additional clinical
factors, 48 clinical scenarios were created that the panel rated for deferred
care safety. Panelists' ratings agreed for 90% of clinical scenarios. These were
formatted into screening criteria. Near-perfect interrater agreement (kappa =
0.9) was found in reproducibility testing. The difference in mean nurse triage
times using the criteria compared with implicit nurse judgment was 0.4 minutes
(95% confidence interval = -2.1 to 2.9 minutes). CONCLUSIONS: Application of
explicit criteria for deferring care of patients with respiratory infection
symptoms did not lengthen triage time. This approach may facilitate more
efficient resource management for ambulatory settings. However, widespread use
before these criteria's, our systematic criteria-based triage should be validated
in multicenter clinical trials against an outcome standard and the more common
implicit approach.
PMID- 10672507
TI - Setting thresholds for quality indicators derived from MDS data for nursing home
quality improvement reports: an update.
AB - BACKGROUND: Determining meaningful thresholds to reinforce excellent performance
and flag potential problem areas in nursing home care is critical for preparing
reports for nursing homes to use in their quality improvement programs. This
article builds on the work of an earlier panel of experts that set thresholds for
quality indicators (QIs) derived from Minimum Data Set (MDS) assessment data.
Thresholds were now set for the revised MDS 2.0 two-page quarterly form and
Resource Utilization Groups III (RUGS III) quarterly instrument. SETTING
THRESHOLDS: In a day-long session in October 1998, panel members individually
determined lower (good) and upper (poor) threshold scores for each QI, reviewed
statewide distributions of MDS QIs, and completed a follow-up Delphi of the final
results. REPORTING MDS QIS FOR QUALITY IMPROVEMENT: The QI reports compiled
longitudinal data for all residents in the nursing home during each quarter and
cumulatively displayed data for five quarters for each QI. A resident roster was
provided to the nursing home so that the quality improvement team could identify
the specific residents who developed the problems defined by each QI during the
last quarter. Quality improvement teams found the reports helpful and easy to
interpret. SUMMARY AND CONCLUSIONS: As promised in an earlier report, to ensure
that thresholds reflect current practice, research using experts in a panel to
set thresholds was repeated as needed. As the MDS instrument or recommended
calculations for the MDS QIs change, thresholds will be reestablished to ensure a
fit with the instrument and data.
PMID- 10672508
TI - Periodic solutions: a robust numerical method for an S-I-R model of epidemics.
AB - We describe and analyze a numerical method for an S-I-R type epidemic model. We
prove that it is unconditionally convergent and that solutions it produces share
many qualitative and quantitative properties of the solution of the differential
problem being approximated. Finally, we establish explicit sufficient conditions
for the unique endemic steady state of the system to be unstable and we use our
numerical algorithm to approximate the solution in such cases and discover that
it can be periodic, just as suggested by the instability of the endemic steady
state.
PMID- 10672509
TI - Transport effects on surface-volume biological reactions.
AB - Many cellular reactions involve a reactant in solution binding to or dissociating
from a reactant confined to a surface. This is true as well for a BIAcore, an
optical biosensor that is widely used to study the interaction of biomolecules.
In the flow cell of this instrument, one of the reactants is immobilized on a
flat sensor surface while the other reactant flows past the surface. Both
diffusion and convection play important roles in bringing the reactants into
contact. Usually BIAcore binding data are analyzed using well known expressions
that are valid only in the reaction-limited case when the Damkohler number Da is
small. Asymptotic and singular perturbation techniques are used to analyze
dissociation of the bound state when Da is small and O(1). Linear and nonlinear
integral equations result from the analysis; explicit and asymptotic solutions
are constructed for physically realizable cases. In addition, effective rate
constants are derived that illustrate the effects of transport on the measured
rate constants. All these expressions provide a direct way to estimate the rate
constants from BIAcore binding data.
PMID- 10672511
TI - Measured and modeled properties of mammalian skeletal muscle. II. The effects of
stimulus frequency on force-length and force-velocity relationships.
AB - Interactions between physiological stimulus frequencies, fascicle lengths and
velocities were analyzed in feline caudofemoralis (CF), a hindlimb skeletal
muscle composed exclusively of fast-twitch fibers. Split ventral roots were
stimulated asynchronously to produce smooth contractions at sub-tetanic stimulus
frequencies. As described previously, the peak of the sub-tetanic force-length
relationship was found to shift to longer lengths with decreases in stimulus
frequency, indicating a length dependence for activation that is independent of
filament overlap. The sub-tetanic force-velocity (FV) relationship was affected
strongly both by stimulus frequency and by length; decreases in either decreased
the slope of the FV relationship around isometric. The shapes of the force
transients following stretch or shortening revealed that these effects were not
due to a change in the instantaneous FV relationship; the relative shape of the
force transients following stretch or shortening was independent of stimulus
frequency and hardly affected by length. The effects of stimulus frequency and
length on the sub-tetanic FV relationship instead appear to be caused by a time
delay in the length-dependent changes of activation. In contrast to feline soleus
muscle, which is composed exclusively of slow-twitch fibers, CF did not yield at
sub-tetanic stimulus frequencies for the range of stretch velocities tested (up
to 2 L0/s). The data presented here were used to build a model of muscle that
accounted well for all of the effects described. We extended our model to account
for slow twitch muscle by comparing our fast-twitch model with previously
published data and then changing the necessary parameters to fit the data. Our
slow-twitch model accounts well for all previous findings including that of
yielding.
PMID- 10672512
TI - Troponin C regulates the rate constant for the dissociation of force-generating
myosin cross-bridges in cardiac muscle.
AB - It is well known that cardiac troponin C (cTnC) regulates the association of
force-generating myosin cross-bridges. We report here evidence for an additional
role for cTnC. This hypothesis states that Ca2+ binds more strongly to cTnC when
force-generating myosin cross-bridges are attached to actin and that removal of
this bound Ca2+ accelerates the dissociation of force-generating myosin cross
bridges. Intact Fura-2-loaded rat papillary muscles and skinned (permeabilized)
ventricular preparations were used. The preparations were mounted in the Guth
Muscle Research System which is capable of measuring simultaneously fluorescence
and force in response to length perturbations. All mechanical perturbations of
muscle length (isotonic shortening, quick stretches and releases, and length
vibrations) which cause dissociation of force-generating myosin cross-bridges
during a twitch resulted in Ca2+ being released from troponin as judged from
changes in the Ca2+ transients (Fura-2 (340/380) fluorescence ratio). Thus
dissociation of force-generating myosin cross-bridges cause Ca2+ to be released
from cTnC. Conversely, it would be expected that removal of strongly bound Ca2+
from cTnC would result in an increase in the rate of dissociation of force
generating myosin cross-bridges. To test this hypothesis actomyosin ATPase (NADH
fluorescence change) and isometric force were measured in skinned cardiac
preparations. The ratio of the ATPase/Force is proportional to the rate constant
(gapp) for the dissociation of force-generating myosin cross-bridges. The data
showed that decreasing the amount of Ca2+ bound to cTnC in skinned cardiac fibers
caused an increase in the ratio of ATPase/Force, the rate of dissociation (gapp)
of force-generating myosin cross-bridges.
PMID- 10672513
TI - The structure of the avian fast skeletal muscle troponin T gene: seven novel
tandem-arranged exons in the exon x region.
AB - To elucidate the mechanism that produces enormous molecular diversity in troponin
T (TnT) of fast skeletal muscle, we determined the 5'-half genomic sequence of
the chicken fast muscle TnT gene. The sequence of ca. 16 kb included seven exons
(exons 1, 2, 3, 4, w, 5, and 6), which have been reported previously and presumed
by sequencing TnT cDNAs. Additionally we found six 15 nt and one 18 nt sequences
in the region between exons 5 and 6 (i.e. the exon x region). They were
encompassed by consensus splice donor and acceptor sites and preceded by putative
branch sites, and designated herein as exons xa to xg. Our result shows that the
sequence derived from exons x1, x2, and x3, the exons presumed previously by cDNA
sequencing, is actually encoded by the seven exons xa to xg, establishing the
precise gene structure in the exon x region. Based on our data, together with
that on the 3'-half genomic sequence of the quail fast muscle TnT gene, we
conclude that the avian fast skeletal muscle TnT gene includes 27 exons, 16 of
which are alternatively spliced.
PMID- 10672510
TI - Understanding dystrophinopathies: an inventory of the structural and functional
consequences of the absence of dystrophin in muscles of the mdx mouse.
PMID- 10672514
TI - Nspl1, a new Z-band-associated protein.
AB - Molecular characterization of a novel gene designated Neuroendocrine-Specific
Protein-Like-1 (Nspl1) had revealed that this gene is expressed as two
transcripts, a 1.2 kb transcript found predominantly in skeletal muscle and a 2.1
kb transcript expressed in the brain. The exceptionally high level of skeletal
muscle expression prompted us to determine where the protein is localized to
skeletal muscle. In vitro studies were performed using two plasmid constructs
that generate full-length Nspl1 muscle-specific protein fused to the green
fluorescent protein (GFP). In one construct, the GFP cDNA was fused to the N
terminus of the Nspl1 cDNA while in the second construct, the GFP cDNA was fused
to the C-terminus of the Nspl1 cDNA. Transfection of either plasmid into
mononucleated myoblasts showed that the Nspl1-GFP chimeric protein was associated
with intermediate filaments. This was confirmed by using an antibody to stain
desmin and finding that GFP-Nspl1 colocalizes with desmin. Chick primary
myoblasts were transfected with the chimeric cDNAs and allowed to differentiate
into mature myotubes. Results from this analysis and the use of monoclonal
antibody to stain alpha-actinin, further localized the Nspl1 protein to the Z
band of mature myotubes. Confocal microscopy of the myotubes containing Nspl1-GFP
demonstrates that Nspl1 is distributed continuously throughout the Z-disks.
PMID- 10672515
TI - Expression and localisation of annexin VII (synexin) isoforms in differentiating
myoblasts.
AB - Annexin VII exists in a 47 kDa and a 51 kDa isoform with the 51 kDa protein being
the only isoform present in skeletal muscle. Expression of the 51 kDa isoform
during myogenesis and localization was studied in cells after conversion into
myogenic cells by transduction with MyoD and in mouse and human myogenic cell
lines. MyoD expression in NIH3T3 and C3H10T1/2 fibroblasts led to disappearance
of the mRNA specific for the 47 kDa isoform and appearance of the 51 kDa isoform
specific mRNA. The overall amount of annexin VII protein was reduced in myogenic
converted cells. Both in undifferentiated and differentiated cells annexin VII
was localized by immunofluorescence microscopy to punctate structures which were
distributed all over the cell. A GFP annexin VII fusion protein showed a similar
distribution. Cell fractionation studies indicated that annexin VII is equally
distributed between cytosol and membrane fractions in undifferentiated cells,
while in differentiated cells it is exclusively present in the membrane fraction.
By sucrose gradient centrifugation of postnuclear supernatants we identified two
distinct annexin VII-containing membrane populations that cofractionated with
caveolin 3- and sorcin-containing membranes.
PMID- 10672516
TI - Differences in the profile of unfused tetani of fast motor units with respect to
their resistance to fatigue in the rat medial gastrocnemius muscle.
AB - In most studies performed on motor units in mammalian muscles the division of
these units into fast and slow types has been based on the 'sag' visible in the
profile of unfused tetanus. The time course of the sag in unfused tetani of fast
motor units was analysed in the present study. Fast units of rat medial
gastrocnemius muscle were classified as fast fatigable (FF) or fast resistant to
fatigue (FR) on the basis of a fatigue index calculated during the standard
fatigue test. In middle-fused tetani (fusion index 0.25-0.75), it was observed
that for FF motor units the sag was shorter and occurred earlier than for FR
units. Moreover, in FF units, the sag was followed by potentiating tension,
whereas for FR units this potentiation was weaker or even absent. A tetanus shape
index, which expressed the ratio of the area of the first part of the tetanus
record (between the tension record and the baseline, from the beginning of
tetanus up to the lowest point during the sag in the tension record) to the area
under the second part of tetanus (from this lowest point up to the end of the
record) was introduced. For FF units, this index ranged from 0.13 to 0.47,
whereas for FR units it ranged from 0.54 to 17.8 (with one exception). These
results showed that the difference in unfused tetanus expressed in this tetanus
shape index could be used as an accurate alternative method of dividing fast
units into FF and FR groups. Moreover, the difference in sag time course in FF
and FR groups. Moreover, the difference in sag time course in FF and FR units
suggests that the metabolism responsible for this contractile phenomenon is
significantly different time courses in IIa and IIb muscle fibres, constituting
FF and FR units, respectively.
PMID- 10672517
TI - An electrophoretic study of myosin heavy chain expression in skeletal muscles of
the toad Bufo marinus.
AB - In this study we developed an SDS-PAGE protocol which for the first time
separates effectively all myosin heavy chain (MHC) isoforms expected to be
expressed in iliofibularis (IF), pyriformis (PYR), cruralis (CRU) and sartorius
(SAR) muscles of the toad Bufo marinus on the basis of previously reported fibre
type composition. The main feature of the method is the use of alanine instead of
glycine both in the separating gel and in the running buffer. The correlation
between the MHC isoform composition of IF, SAR and PYR muscles determined in this
study and the previously reported fibre type composition of IF and SAR muscles in
the toad and of PYR muscle in the frog was used to tentatively identify the MHC
isoforms expressed by twitch fibre types 1, 2 and 3 and by tonic fibres. The
alanine-SDS electrophoretic method was employed to examine changes in the MHC
composition of IF, PYR, CRU and SAR muscles with the ontogenetic growth of the
toad from post-natal life (body weight < 1 g) to late adulthood (body weight 200
450 g). The developmental changes in the MHC isoform composition of the toad IF
muscle observed in this study are in very good agreement with those in the fibre
type composition of the developing IF muscle reported in the literature.
PMID- 10672518
TI - Junctions between subsynaptic folds and rough sarcoplasmic reticulum of muscle
fibres.
AB - Serial sections through motor end plate regions of mouse muscle fibres
demonstrated junctions between the subsynaptic folds and the rough sarcoplasmic
reticulum of the sole plate nuclei. The shape of these structures resembles that
of the well-known peripheral couplings, diads and triads of muscle fibres.
However, the location of the new junctions between the surface membrane and the
sole plate nuclei at a large distance from myofibrils, indicates a different
function. The connection with the rough sarcoplasmic reticulum possibly influence
the regulation of fibre protein metabolism, for example, gene expression of
acetylcholine receptor synthesis.
PMID- 10672519
TI - The interface between MyBP-C and myosin: site-directed mutagenesis of the CX
myosin-binding domain of MyBP-C.
AB - Myosin-binding protein-C (MyBP-C or C-protein) is a ca. 130 kDa protein present
in the thick filaments of all vertebrate striated muscle. The protein contains
ten domains, each of ca. 90-100 amino acids; seven are members of the IgI family
of proteins, three of the fibronectin type III family. The motifs are arranged in
the following order (from N- to C-terminus): Ig-Ig-Ig-Ig-Ig-Fn-Fn-Ig-Fn-Ig. The C
terminal Ig motif (domain X or CX) contains its light meromyosin-binding site. A
recombinant form of CX, beginning at Met-1027, exhibits saturable binding to
myosin with an affinity comparable to the C-terminal 13 kDa chymotryptic fragment
of native MyBP-C. To identify the surface in CX involved in its interaction with
myosin, nine site-directed mutants (R37E, K43E, N49D, E52R, D56K, R73E, R74E,
G80D and R103E) were constructed. Using a new assay for assessing the binding of
CX with the light meromyosin (LMM) portion of myosin, we demonstrate that
recombinant CX, just as the full-length protein, is able to facilitate LMM
polymerization. Moreover, we show that residues Arg-37, Glu-52, Asp-56, Arg-73,
and Arg-74 are involved in this interaction with the myosin rod. All of these
amino acids interact with negatively charged residues of LMM, since the mutants
R37E, R73E and R74E are unable to bind myosin, whereas E52R and D56K bind myosin
with higher affinity than wild-type CX. Residues Lys-43 and Arg-103 show a small
but significant influence on the binding reaction; residues Asn-49 and Gly-80
seem not to be involved in this interaction. Based on these data, a model is
proposed for the interaction between MyBP-C CX and myosin filaments. In this
model, CX interacts with four molecules of LMM at four different sites of the
binding protein, thus explaining the effects of MyBP-C on the critical
concentration of myosin polymerization.
PMID- 10672520
TI - Comparison of cross-bridge cycling kinetics in neonatal vs. adult rat ventricular
muscle.
AB - The developmental shift in contractile protein isoform expression in the rodent
heart likely affects actin-myosin cross-bridge interactions. We compared the Ca2+
sensitivity for force generation and cross-bridge cycling kinetics in neonatal
(postnatal days 0-3) and adult (day 84) rats. The force-pCa relationship was
determined in Triton-X skinned muscle bundles activated at pCa 9.0 to 4.0. In
strips maximally activated at pCa 4.0, the following parameters of cross-bridge
cycling were measured: (1) rate of force redevelopment following rapid shortening
and restretching (ktr); and (2) isometric stiffness at maximal activation and in
rigor. The fraction of attached cross-bridges (alpha fs) and apparent rate
constants for cross-bridge attachment (fapp) and detachment (gapp) were derived
assuming a two-state model for cross-bridge cycling. Compared to the adult, the
force-pCa curve for neonatal cardiac muscle was significantly shifted to the
left. Neonatal cardiac muscle also displayed significantly smaller alpha fs,
slower ktr and fapp; however, gapp was not significantly different between age
groups. These data indicate that weaker force production in neonatal cardiac
muscle involves, at least in part, less efficient cross-bridge cycling kinetics.
PMID- 10672521
TI - A note on the caldesmon sequence.
PMID- 10672522
TI - Measurement of UV radiation using suspensions of microorganisms.
AB - The measurement of solar UV radiation is usually performed using physical devices
like photodiodes or photomultipliers or with chemical substances (actinometry).
The application of biological material such as microorganisms for this purpose
has gained increasing importance in the last few years. The microorganisms may be
dried and spread on a flat surface or they may be in aqueous suspensions
contained in UV-transparent vessels. If the measurements are done on flat
surfaces, the irradiance weighted by the action spectrum of the dried
microorganism used is the result of the measurement. If aqueous suspensions of
microorganisms are used, contained for instance in spherical vessels, the fluence
weighted by the action spectrum of the microorganisms in the aqueous suspension
is the result. A problem of this method of measurement can be that inside the
vessel the distribution of UV radiation is usually not homogeneous, causing
distributions of fluences among the irradiated microorganisms, which may result
in variation of the results depending on the mixing characteristics of the
suspension during irradiation.
PMID- 10672523
TI - Comparative measurements of solar UV radiation with spore dosimetry at three
European and two Japanese sites.
AB - Spore dosimetry of solar UV radiation has been employed in several field
intercomparison campaigns carried out in summer months in Japan and Europe. The
dose-rate profiles, total daily doses and personal daily exposures have been
determined and compared at five sites based on the spore inactivation dose (SID).
The maximum dose rate (0.83 SID/min) and the maximum daily dose (197 SID)
observed at subtropical Naha (26.2 degrees N) are about three times those
observed at subarctic Abisko (68.4 degrees N). The amounts of personal exposure
during three European campaigns are moderate and show a tendency of inverse
relationships with the daily doses.
PMID- 10672524
TI - 'Vitamin D' biodosimeter: basic characteristics and potential applications.
AB - The biologically important process of endogenous synthesis of vitamin D under UV
solar irradiation is widespread in the biosphere and inherent to most animals and
plants. A new method of biological dosimetry of UV radiation based on an in vitro
model of vitamin D synthesis ('D-dosimeter') is discussed. Unlike the vast
majority of biodosimeters, the action of which depends on the UV sensitivity of
DNA and thus reflects damaging effects of UV radiation, the process of vitamin D
synthesis is beneficial by its nature. To date, the complex network of photo- and
thermoreactions of vitamin D synthesis in vitro is well understood, and an
adequate mathematical model is available, ensuring a link between biological and
physical units. Original spectral analysis of the multicomponent photoisomer
mixture has been specially designed to provide the most effective use of the D
dosimeter in situ. Spectral selectivity (exceptional sensitivity of certain
parameters to the spectral composition of UV radiation) extends the usefulness of
the method.
PMID- 10672525
TI - The role of the spectral sensitivity curve in the selection of relevant
biological dosimeters for solar UV monitoring.
AB - To estimate the risk of enhanced UV-B radiation due to stratospheric ozone
depletion, phage T7 and uracil thin-layer biological dosimeters have been
developed, which weight the UV irradiance according to induced DNA damage. To
study the molecular basis of the biological effects observed after UV
irradiation, the spectral sensitivity curves of the two dosimeters and induction
of the two major DNA photoproducts, cyclobutane pyrimidine dimers (CPDs) and 6-4
photoproducts ((6-4)PDs), in phage T7 have been determined for polychromatic UV
sources. CPDs and (6-4)PDs are determined by lesion-specific monoclonal
antibodies in an immunodotblot assay. Phage T7 and uracil biological dosimeters
together with a Robertson-Berger (RB) meter have been used for monitoring
environmental radiation from the polar region to the equator. The biologically
effective dose (BED) established with the three different dosimeters increases
according to the changes in the solar angle and ozone column, but the degree of
the change differs significantly. The results can be explained based on the
different spectral sensitivities of the dosimeters. A possible method for
determining the trend of the increase in the biological risk due to ozone
depletion is suggested.
PMID- 10672526
TI - Influence of spectral and angular sensitivity on the readout of biological
dosimeters.
AB - Biological systems used as biological dosimeters can possess different angular
sensitivities from the detectors usually used in physical devices. A simple
experimental setup has been developed and used to measure the angular sensitivity
of uracil thin-layer biological dosimeters. Results of angular sensitivity
measurements for uracil thin-layer dosimeters are presented using a Xe arc lamp
as the UV source. According to the experiments described here, uracil thin-layer
dosimeters show a cosine-type angular dependence. In several indoor experiments
broadband UV meters are used to control the applied dose rate from a given
artificial UV source. The experimental setup has been designed and used to verify
experimentally the importance of spectral and angular sensitivity differences of
biological and physical UV meters applied in biological experiments. Model
calculations for two different irradiation systems, using different geometrical
arrangements of artificial UV sources, are also presented. For these arrangements
relative dose rates that could be measured with dosimeters of arbitrary spectral,
but different angular sensitivity have been calculated.
PMID- 10672527
TI - Biological UV dosimeters in the assessment of the biological hazard from
environmental radiation.
AB - To determine the impact of environmental UV radiation, biological dosimeters that
weight directly the incident UV components of sunlight have been developed,
improved and evaluated in the frame of the BIODOS project. Four DNA-based
biological dosimeters ((i) phage T7, (ii) uracil thin layer, (iii) spore
dosimeter and (iv) DLR-biofilm) have been assessed from the viewpoint of their
biological relevance, spectral response and quantification of their biological
effectiveness. The biological dosimeters have been validated by comparing their
readings with weighted spectroradiometer data, by comparison with other
biological doses, as well as with the determined amounts of DNA UV photoproducts.
The data presented here demonstrate that the biological dosimeters are
potentially reliable field dosimeters for measuring the integrated biologically
effective irradiance for DNA damage.
PMID- 10672528
TI - Photodynamic parameters in the chick chorioallantoic membrane (CAM) bioassay for
topically applied photosensitizers.
AB - The relative efficacy of Photofrin-based photodynamic therapy (PDT) has been
compared with that of the second-generation photosensitizers 5-aminolevulinic
acid (ALA), sulfonated chloro-aluminum phthalocyanine (AlPcSn), benzoporphyrin
derivative monoacid ring A (BPD-MA), and lutetium texaphyrin (Lutex). PDT-induced
vascular damage in the chick chorioallantoic membrane (CAM) is measured following
topical application of the photosensitizers. In order to make meaningful
comparisons, care is taken to keep treatment variables the same. These include
light dose (5 and 10 J/cm2), power density (33 and 100 mW/cm2), and drug uptake
time (30 and 90 min). The drug dose ranges from 0.1 microgram/cm2 for BPD to 5000
micrograms/cm2 for ALA. Results are also analyzed statistically according to CAM
vessel type (arterioles versus venules), vessel diameter, and vessel development
(embryonic age). For each photosensitizer, the order of importance for the
various PDT parameters is found to be unique. The differences between the
sensitizers are most likely due to variation in biophysical and biochemical
characteristics, biodistribution, and uptake kinetics.
PMID- 10672529
TI - Comparison of phototoxicity mechanism between pulsed and continuous wave
irradiation in photodynamic therapy.
AB - A study has been conducted in which HeLa cells are incubated with hematoporphyrin
derivative (HpD) for 1 h (1 microgram/ml of HpD in PBS) to compare the use of
continuous wave (CW) and pulsed laser (10 Hz repetition rate and 7-9 ns pulse
width) light for photodynamic therapy. Cytotoxic effects on the cells are
evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2-5-diphenyl-2H-tetrazolium bromide
(MTT) assay and the fluorescein diacetate (FDA)/propidium iodide (PI) stain
method using a flow cytometer. The type of cell death is estimated by analysis of
the DNA content and observation of the nuclear morphology. The cytotoxicity ratio
of cells irradiated by pulsed laser light is estimated to be lower than that for
CW laser light. The viability of cells that received pulsed laser light gradually
decreases, whereas no significant changes are found in the cells irradiated with
CW laser light with the elapse of post-irradiation time. The type of cell death
differs between the pulsed and CW laser light irradiations. These findings
suggest that the cytotoxic efficacy of the excitation light source is displayed
by the difference in the type of cell death, namely apoptosis or necrosis.
PMID- 10672530
TI - A theoretical and experimental study of two thiazole orange derivatives with
single- and double-stranded oligonucleotides, polydeoxyribonucleotides and DNA.
AB - The effect of interaction with DNA and oligonucleotides on the photophysical
properties of two thiazole orange (TO) derivatives, with different side chains (
(CH2)3-N+(CH3)3 and -(CH2)6-I)) linked to the nitrogen of the quinoline ring of
the thiazole orange, is presented here. The first one called TO-PRO1 is a
commercially available dye, whereas the second one called TO-MET has been
specially synthesized for further covalent binding to oligonucleotides with the
aim of being used for specific in situ detection of biomolecular interactions.
Both photophysical measurements and molecular calculations have been done to
assess their possible mode of interaction with DNA. When dissolved in buffered
aqueous solutions both derivatives exhibit very low fluorescence quantum yields
of 8 x 10(-5) and 2 x 10(-4), respectively. However, upon binding to double
stranded DNA, large spectroscopic changes result and the quantum yield of
fluorescence is enhanced by four orders of magnitude, reaching values up to phi F
= 0.2 and 0.3, respectively, as a result of an intercalation mechanism between
DNA base pairs. A modulation of the quantum yield is observed as a function of
the base sequence. The two derivatives also bind with single-stranded
oligonucleotides, but the fluorescence quantum yield is not so great as that when
bound to double-stranded samples. Typical fluorescence quantum yields of 7 x 10(
3) to 3 x 10(-2) are observed when the dyes interact with short oligonucleotides,
whereas the fluorescence quantum yield remains below 10(-2) when interacting with
single-stranded oligonucleotides. This slight but significant quantum-yield
increase is interpreted as a folding of the single strand around the dye, which
reduces the internal rotation of the two heterocycles around the central methine
bridge that links the two moieties of the dye. From these properties, it is
proposed to link monomer covalently to oligonucleotides for the subsequent
detection of target sequences within cells.
PMID- 10672531
TI - Horizontal and sun-normal spectral biologically effective ultraviolet
irradiances.
AB - The dependence of the spectral biologically effective solar UV irradiance on the
orientation of the receiver with respect to the sun has been determined for
relatively cloud-free days at a sub-tropical Southern Hemisphere latitude for the
solar zenith angle range 35-64 degrees. For the UV and biologically effective
irradiances, the sun-normal to horizontal ratio for the total UV ranges from 1.18
+/- 0.05 to 1.27 +/- 0.06. The sun-normal to horizontal ratio for biologically
effective irradiance is dependent on the relative effectiveness of the relevant
action spectrum in the UV-A waveband. In contrast to the total UV, the diffuse UV
and diffuse biologically effective irradiances are reduced in a sun-normal
compared with a horizontal orientation by a factor ranging from 0.70 +/- 0.05 to
0.76 +/- 0.03.
PMID- 10672532
TI - Photodynamic therapy using 5-aminolaevulinic acid for oesophageal adenocarcinoma
associated with Barrett's metaplasia.
AB - Photodynamic therapy (PDT) is a novel technique for local endoscopic treatment of
gastrointestinal neoplasia. Current photosensitisers for PDT may cause prolonged
skin phototoxicity. 5-Aminolaevulinic acid (ALA), a precursor of the
photosensitiser protoporphyrin IX (PpIX), is more acceptable because of its short
half-life and preferential accumulation in mucosa and mucosal tumour. We have
treated 12 patients, median age 73 years (range 55-88) with oesophageal
adenocarcinoma arising from Barrett's metaplasia (two carcinomas-in-situ, grade
0; 10 carcinomas, grade 1-11A based on endoluminal ultrasound in two and CT
scanning in 10 patients). ALA (60 and 75 mg/kg body weight) was given orally in
two or five equally divided doses. The PpIX distribution in stomach, normal
oesophagus, Barrett's mucosa and carcinoma was measured by quantitative
fluorescence photometry. PDT was performed using laser light (630 nm) delivered
via a cylindrical diffuser 4-6 h after the first dose of ALA. The patients
received one to four sessions of PDT. PpIX accumulation in the mucosa was two to
three times that in the lamina propria. The differential distribution between
carcinomatous and normal oesophageal mucosa was less marked (carcinoma:normal
mucosa ratio = 1.4). Higher doses of ALA increased PpIX accumulation in all
tissues but did not increase the differential PpIX distribution between tumour
and normal oesophageal mucosa. After PDT using ALA (ALA/PDT), all mucosa showed
superficial white necrotic changes and the histology confirmed fibrinoid
necrosis. One patient with carcinoma-in-situ had the tumour eradicated after one
treatment with no recurrence at 28 months. Another patient with a small T1 tumour
required four ALA/PDT treatments, and died of other disease after 36 months.
There was no evidence of recurrence. The tumour bulk in the other carcinomas was
not significantly reduced. ALA/PDT has a potential for the eradication of small
tumours but careful patient selection with endoluminal ultrasound is needed when
using ALA/PDT to treat oesophageal cancer.
PMID- 10672533
TI - Acid-base properties of chlorin e6: relation to cellular uptake.
AB - Chlorins are attractive compounds for photodynamic therapy because of their high
absorption in the red spectral region. In this study, the absorbance,
fluorescence excitation and fluorescence emission spectra of chlorin e6 have been
recorded as functions of pH in phosphate-buffered saline (PBS) solution with and
without fetal calf serum (FCS). For pure PBS solutions, variation of the pH of
the solution results in a shift of both the absorption and the fluorescence
spectrum as well as in a decrease of the fluorescence intensity.
Spectrophotometric and fluorimetric titration curves, based on observed changes,
have been plotted. There is an indication of aggregate formation at low pH values
(pH < 5). The presence of 5% FCS results in a shift of the titration curve, from
an inflection point at about 6.5 to one at about 7.6. Pronounced spectral changes
of the fluorescence emission spectra of protein-bound chlorin e6 (change of
spectral shape, decrease of peak intensity) are also observed. The partition
coefficients in the 1-octanol-water system increase with decreasing pH. Thus,
relatively more of the drug is incorporated in the octanol phase at low pH.
Cellular uptake of chlorin e6 in the presence of serum is significantly higher at
pH 6.7 as compared with that at 7.3 and 7.6. We conclude that a change in the pH
value of the surrounding medium leads to a change in the lipophilicity of chlorin
e6. Such a change is likely to influence its binding to the serum proteins as
well as its interaction with the plasma membrane of cells and may also be related
to the selective tumor uptake of the drug.
PMID- 10672534
TI - Synthesis, photochemistry and application of (7-methoxycoumarin-4-yl)methyl-caged
8-bromoadenosine cyclic 3',5'-monophosphate and 8-bromoguanosine cyclic 3',5'
monophosphate photolyzed in the nanosecond time region.
AB - New caged derivatives of hydrolysis-resistant 8-bromoadenosine cyclic 3',5'
monophosphate (8-Br-cAMP) and 8-bromoguanosine cyclic 3',5'-monophosphate (8-Br
cGMP) are described. The compounds are the axial and equatorial isomers of the (7
methoxycoumarin-4-yl)methyl (MCM) esters of cyclic nucleotides. Synthesis is
accomplished by treatment of 4-bromomethyl-7-methoxycoumarin with the tetra-n
butylammonium salts of the 8-bromo-substituted cyclic nucleotides or with the
free acids of 8-Br-cAMP and 8-Br-cGMP in the presence of silver(I) oxide. MCM
caged 8-Br-cAMP and MCM-caged 8-Br-cGMP liberate 8-Br-cAMP and 8-Br-cGMP during
irradiation with ultraviolet light within a few nanoseconds. They show favorable
absorption properties and quantum yields and are resistant to hydrolysis in
aqueous buffer solutions. The moderate fluorescence properties of the caged
compounds in comparison with the strongly fluorescent 4-hydroxymethyl-7
methoxycoumarin (MCM-OH) photoproduct allow the indirect estimation of the amount
of photolytically released cyclic nucleotides in aqueous buffer solutions using
fluorescence measurements. Their usefulness for physiological studies has been
examined in a mammalian cell line expressing the cyclic nucleotide-gated ion
channel of bovine olfactory sensory neurons using the patch-clamp technique and
confocal laser scanning microscopy. The caged compounds serve as efficient and
rapid intracellular sources of 8-Br-cAMP and 8-Br-cGMP. However, at least in HEK
293 cells, fluorescence signals cannot be used to monitor the photolysis of MCM
caged 8-Br-cAMP and 8-Br-cGMP, due to quenching of the fluorescence of MCM-OH.
PMID- 10672535
TI - Photothermal sensitization of amelanotic melanoma cells by Ni(II)-octabutoxy
naphthalocyanine.
AB - Incubation of B78H1 amelanotic melanoma cells with a potential photothermal
sensitizer, namely, liposome-incorporated Ni(II)-octabutoxy-naphthalocyanine
(NiNc), induces an appreciable cellular accumulation of the naphthalocyanine,
which is dependent on both the NiNc concentration and the incubation time. No
detectable decrease in cell survival occurs upon red-light irradiation
(corresponding to the longest-wavelength absorption bands of NiNc) in a
continuous-wave (c.w.) regime of the naphthalocyanine-loaded cells. On the other
hand, 850 nm irradiation with a Q-switched Ti:sapphire laser operating in a
pulsed mode (30 ns pulses, 10 Hz, 200 mJ/pulse) induces an efficient cell death.
Thus, ca. 98% decrease in cell survival is obtained upon 5 min irradiation of
cells that have been incubated for 48 h with 5.1 microM NiNc. The efficiency of
the photoprocess is strongly influenced by the NiNc cell incubation time prior to
irradiation. Photothermal sensitization with NiNc appears to open new
perspectives for therapeutic applications, as suggested by preliminary in vivo
studies with C57/BL6 mice bearing a subcutaneously implanted amelanotic melanoma.
PMID- 10672536
TI - Skin photosensitization with topical hypericin in hairless mice.
AB - Hypericin, a naturally occurring photosensitizer, exhibits interesting in vitro
photobiological activities, which suggest that the compound is a potential
antipsoriatic agent. In this study, the possibility of hypericin penetrating the
skin in photo-active concentrations has been studied. Hypericin is incorporated
in either emulsifying ointment supplemented with solketal (hypericin content:
0.05%) or in polyethylene glycol (PEG) ointment (hypericin content: 0.5%) and
applied to the skin of hairless mice for 4 h. After removing excess ointment, the
mice are then irradiated with different light doses using a 500 W halogen lamp.
As a positive control, intraperitoneally (i.p.) administered hypericin (10 and 40
mg/kg) has also been tested. Erythema, desquamation and erosions are demonstrated
in the mice treated with hypericin in emulsifying ointment with solketal using a
light dose of at least 4.5 J/cm2. In general, these reactions correlate well with
those of i.p. administered hypericin (40 mg/kg), indicating that hypericin
incorporated in emulsifying ointment with solketal is well absorbed by the skin
of the mice. However, for the i.p. administered hypericin (40 mg/kg), we could
not evaluate phototoxic reactions in the group of animals that received a light
dose of 108 J/cm2, as they all died 12-24 h after irradiation, indicating extreme
photosensitization with systemic hypericin at higher light doses. On the
contrary, there is no measurable skin photosensitivity induced by hypericin when
incorporated in PEG ointment or when 10 mg/kg hypericin is i.p. administered. Our
results show that hypericin incorporated in a suitable vehicle can be delivered
to the skin in photo-active concentrations. Using a vehicle such as emulsifying
ointment with solketal, it will be possible to explore the photo-activity of
hypericin in the treatment of psoriasis and other skin diseases.
PMID- 10672537
TI - Time-resolved detection of singlet oxygen luminescence in red-cell ghost
suspensions: concerning a signal component that can be attributed to 1O2
luminescence from the inside of a native membrane.
AB - For about ten years, it has been debated whether in principle it is possible to
detect 1O2 located within the cell membrane by performing experiments with cell
suspensions or even in tissue. In this paper we present our investigations on
photosensitized red-cell ghost suspensions (RCGSs) and our strategy for the
detection of luminescence of singlet oxygen (1O2) from the inside of the cell
membrane. Using a very sensitive apparatus for time-resolved 1O2 detection, a
very promising sensitizer and an adequate experimental strategy, a very small
amount of the detected luminescence indeed can be attributed to 1O2 from the
inside of the ghost membrane.
PMID- 10672538
TI - Analysis of UV-B-induced DNA damage and its repair in heat-shocked skin cells.
AB - The heat-shock response is a cellular defence mechanism against environmental
stresses that is evolutionarily conserved from bacteria to man. Numerous reports
demonstrate the beneficial effects of heat-shock protein induction on cell
survival under toxic or oxidative stress, e.g., in cardiac and cerebral ischemia
or prior to organ transplantation. However, there is little data on the effects
of heat treatment on damage caused by UV irradiation. Applying three independent
techniques, we have tested the influence of thermal pretreatment of skin cells (1
h, 43 degrees C) on the initial extent of UV-B-induced DNA damage and its
subsequent repair. For cultured human epidermal keratinocytes and dermal
fibroblasts we can show reduced levels of nucleotide-excision-repair-associated
DNA strand incision in the comet assay. Moreover, immunostaining and flow
cytometric quantitation of thymidine dimers immediately and one day after
irradiation, respectively, reveal that the initial DNA damage is not
(keratinocytes) or only moderately (fibroblasts) lower in heat-shocked cells as
compared to untreated controls. However, excision repair of dimers is
significantly attenuated during the first 24 h in both cell types. Furthermore,
using a modified host-cell reactivation assay, we are able to demonstrate that
repair of UV-B-damaged plasmid DNA is lower if the transfected cells are
previously heat shocked. In summary, heat treatment (1 h, 43 degrees C) inducing
heat-shock proteins reduces nucleotide excision repair of UV-B-mediated DNA
lesions in fibroblasts and keratinocytes during the following 24 h. This is not
necessarily caused by elevated heat-shock protein levels themselves. Possibly the
direct thermal damage of repair enzymes is more severe than the potential
protective effects of heat-shock proteins.
PMID- 10672539
TI - In vivo detection and staging of epithelial dysplasias and malignancies based on
the quantitative assessment of acetic acid-tissue interaction kinetics.
AB - A novel approach to the problem of non-destructive detection and staging of
tissue lesions is presented. The method relies on the in vivo quantitative
assessment of the spatial and temporal alterations of light-scattering
properties, induced in epithelial dysplasias and malignancies of the cervix and
larynx, after topical application of acetic acid solution. Initial clinical
trials show that the method is capable of detecting incipient lesions and that
differences in the dysplasia and malignancy grade are clearly manifested in the
measured temporal characteristics of the phenomenon.
PMID- 10672540
TI - Effects of partial blood engorgement and pretest carbohydrate availability on the
repellency of deet to Aedes albopictus.
AB - The pretest availability of 10% sucrose solution and/or partial blood engorgement
in Aedes albopictus Skuse significantly influenced mosquito attack rates and the
time of repellent protection in laboratory bioassays. In 46 cm L x 38 cm W x 37
cm H cages used in USDA repellent tests, non-blood-fed and partially blood-fed
mosquitoes attempted to bite at similar rates. In small cages (5 cm dia. x 4 cm
H), holding individual females, mean mosquito attack rates were reduced when
females were partially blood fed, compared with those not blood fed. The
protection period from bites by Ae. albopictus using 25% ethanolic deet (N,N
diethyl-3-methylbenzamide) increased significantly in small and USDA standard
cages when females had pretest access to sucrose solution, compared with females
starved for 12 h. Partial blood engorgement in mosquitoes affected repellent
protection time in USDA standard test cages but not in small cages.
PMID- 10672541
TI - A world checklist of genera, subgenera, and species of ticks (Acari: Ixodida)
published from 1973-1997.
AB - Researchers on ticks and tickborne diseases have been extremely fortunate in
having at their fingertips the tick bibliographies produced by Harry Hoogstraal
and his coworkers at the U.S. Naval facility at Cairo, Egypt, and by Mildred Doss
and her colleagues at the U.S. Department of Agriculture laboratory at
Beltsville, Maryland, USA. The Doss checklist of tick families, genera, species,
and subspecies is now 25 years out of date, and the following checklist of one
new genus, nine new subgenera, and 110 new species of Ixodida brings together the
nomenclature on ticks produced during the last quarter century.
PMID- 10672542
TI - Larval habitats of anopheline mosquitoes in the Upper Orinoco, Venezuela.
AB - Survey of larval habitats of anopheline mosquitoes was conducted in Ocamo in the
State of Amazonas, southern Venezuela. The sampled habitats belonged to three
different hydrological types: lagoons (26 habitats), forest pools including
flooded forest (16 habitats), and forest streams (4 habitats). Out of 46 habitats
surveyed, 31 contained anopheline larvae. Six species were found: Anopheles
darlingi, Anopheles triannulatus, Anopheles oswaldoi, Anopheles peryassui,
Anopheles punctimacula, and Anopheles mediopunctatus. Anopheles triannulatus was
the most abundant species. Significantly higher numbers of anopheline larvae, in
general, and of An. triannulatus specifically were found in lagoons with
submersed macrophytes and sparse emergent graminoids than in forest pools with
detritus.
PMID- 10672543
TI - Mosquito control and bacterial flora in water enriched with organic matter and
treated with Bacillus thuringiensis subsp. israelensis and Bacillus sphaericus
formulations.
AB - Three tests were conducted during July 17 to October 30, 1998 to study the impact
of two mosquitocidal microbial agents on mosquito larvae and their contribution
to bacterial flora in aquatic microcosms. Formulations of Bacillus thuringiensis
subsp. israelensis (Bti) and Bacillus sphaericus strain 2362 (Bsph) were applied
at various rates to outdoor tubs enriched with rabbit pellets and filled with
irrigation water from a reservoir. Mosquito larvae were effectively controlled by
all treatments; the magnitude of initial and persistent control depended on
materials and dosages applied. Bacterial flora were assessed in the irrigation
water as well as water in the enriched tubs before and after treatment with the
microbial agents. The irrigation water contained 800-1000 total bacterial
cells/ml. The populations of total bacteria and spore formers peaked on day 3
after enriching and filling the tubs, then declined progressively to the low
levels at the end of the tests. After treatment, the numbers of Bti and Bsph
spores in treated tubs prevailed at a dosage-dependent manner, their populations
peaked at three hours after treatment, and declined progressively thereafter. The
contribution of Bti and Bsph spores to the total bacterial flora was negligible
but significant to the counts of spore-forming bacteria. The gram-negative
bacteria made up more than 80% of the total bacterial flora during the test
periods; and, of these, gram-negative rods constituted the greatest proportion,
gradually increasing from the time of flooding to the end of the tests. Gram
negative cocci also occurred in relatively great proportion, but showed a reverse
trend as compared with the gram-negative rods, declining gradually from
pretreatment to the end of the tests. Gram-positive rods (spore formers),
including Bti and Bsph, occurred in low numbers in all the tests but increased
slightly in treated tubs due to the addition of Bti and Bsph spores. Gram
positive cocci occurred occasionally in some water samples.
PMID- 10672544
TI - Field efficacy of fipronil 3G, lambda-cyhalothrin 10%CS, and sumithion 50EC
against the dengue vector Aedes albopictus in discarded tires.
AB - The efficacy of three insecticides, fipronil 3G, lambda-cyhalothrin 10%CS, and
sumithion 50EC were evaluated against the dengue vector Aedes albopictus in
discarded tires in Kuala Lumpur, Malaysia. The dosage given for each insecticide
was 0.01 g of active ingredient/m2. Fipronil 3G was the most effective larvicide
with a residual activity of up to two weeks, causing 88% mortality in Aedes
albopictus. Lambda-cyhalothrin 10%CS was effective for one week causing 92%
larval mortality and two weeks with 63% larval mortality. Sumithion 50EC had a
residual efficacy of one week with 79% larval mortality.
PMID- 10672545
TI - Reproductive biology of Lutzomyia shannoni (Dyar) (Diptera: Psychodidae) under
experimental conditions.
AB - Baseline biological growth data of Lutzomyia shannoni (Dyar) were compared under
two experimental conditions within insulated styrofoam chests and in standard
laboratory incubators. The developmental time from egg to adult was 67 and 52
days, respectively. Based on cohorts of 100 females in each experiment,
horizontal life tables were constructed. The following predictive parameters were
obtained under each of the two conditions: net rate of reproduction (23.5 and
18.0 females per cohort female), generation time (11.4 and 9.4 weeks), intrinsic
rate of population increase (0.27 and 0.30), and finite rate of population
increment (1.31 and 1.36). The reproductive value for each class age of the
cohort females was calculated. The observed parameters were obtained under each
experimental condition: net rate of reproduction (1.9 and 2.5 females per cohort
female), generation time (11.7 and 9.6 weeks), intrinsic rate of population
increase (0.05 and 0.09), and finite rate of population increment (1.06 and
1.10). Vertical life tables were elaborated and mortality was described for every
generation in each cohort. In addition, for two successive generations, additive
variance and heritability for fecundity were estimated.
PMID- 10672546
TI - The fleas (Siphonaptera) of South Carolina with an assessment of their vectorial
importance.
AB - We document 25 species of fleas from South Carolina including new state records
for two species, the ctenophthalmids Epitedia cavernicola and Rhadinopsylla
orama. Host and other collection data, by county, are provided, including many
new records amassed from 1992-1998 and some older records gleaned from the
Clemson University Arthropod Collection. One flea species, the rhopalopsyllid
Polygenis gwyni, is especially common and widespread in South Carolina,
particularly on the cotton rat (Sigmodon hispidus) in coastal plain habitats. The
largest number of flea species (8) from a single host species was recorded from
the cotton mouse, Peromyscus gossypinus. Several flea species of potential
medical or veterinary importance were recorded, some of which are potential
vectors of pathogens, such as the agents of murine typhus, murine typhus-like
disease, sylvatic epidemic typhus, cat scratch disease, and rodent bartonellosis.
A host-flea list for South Carolina is included.
PMID- 10672547
TI - Experimental studies of interactions between wild turkeys and black-legged ticks.
AB - Wild turkeys are increasing in abundance and distribution in eastern North
America, but their potential role as hosts for ticks, or as predators on ticks,
is unknown. We performed two experiments, one to determine whether juvenile black
legged ticks (Ixodes scapularis) feed successfully on turkeys, and the other to
determine if turkeys depredate adult black-legged ticks in forest habitats. Of
550 larval ticks placed directly on 5 captive wild turkeys, none engorged and
only 7 (1.3%) were recovered; the remainder apparently were consumed during
preening. Of 165 nymphal ticks placed on the turkeys, 5 engorged and 8 unengorged
ticks were collected; 152 (93.3%) were apparently consumed. Of 250 adult ticks
introduced into forest enclosures exposed to turkey foraging, 89.5% were
recaptured, which was not significantly different from the 92.2% recaptured in
control enclosures from which turkeys were excluded. We conclude that wild
turkeys are unlikely to host juvenile black-legged ticks in nature, and that
turkey foraging is unlikely to reduce local density of adult ticks.
PMID- 10672548
TI - Susceptibility of the malaria vector Anopheles culicifacies (Diptera: Culicidae)
to DDT, dieldrin, malathion, and lambda-cyhalothrin.
AB - The susceptibility of the malaria vector Anopheles culicifacies to DDT, dieldrin,
malathion, and lambda-cyhalothrin was determined in Karnal, Yamunanagar, and
Ambala districts of Haryana State, India. The vector population showed a high
degree of resistance to DDT and dieldrin. The test mortality to DDT and dieldrin
ranged from 25% to 28% and 18% to 20%, respectively, in Nadasahib of Ambala
districts. The mortality of An. culicifacies to malathion ranged between 65% and
68%. All the tests with lambda-cyhalothrin resulted in 100% mortality of An.
culicifacies. DDT and dieldrin resistance did not confer cross-resistance to
lambda-cyhalothrin in An. culicifacies.
PMID- 10672549
TI - Bacteria and mosquito abundance in microcosms enriched with organic matter and
treated with a Bacillus thuringiensis subsp. israelensis formulation.
AB - Bacteria and mosquito abundance were studied in outdoor tubs unenriched and
enriched with 0.04% rabbit pellets during the winter, 1999. The irrigation water
used to fill the tubs contained a total bacterial count of 1.15-1.35 x 10(3)
cells/ml. Adding rabbit pellets for enrichment yielded a total bacterial count of
5.50-7.63 x 10(5) cells/g. Bacterial densities in unenriched water were
significantly lower than in enriched tubs on every sampling day. When bacterial
densities in both enriched and unenriched regimens reached peak populations on
day 3 post-flooding, their numbers in enriched water were 25-fold higher than the
unenriched water. Under cool weather conditions, mosquito oviposition activity
was low and larval development was very slow. Egg raft counts and larval
densities in enriched water were nevertheless higher than those in unenriched
water. After reaching peak populations on day 3 post-flooding, the natural
decline in bacterial densities in the top portion of enriched water without
mosquito larvae was lower compared with that in water with larvae. In water with
larval present, the decline of bacterial levels in top water was greater than in
bottom water on day 7 post-flooding. VectoBac G, a granular formulation of
Bacillus thuringiensis subsp. israelensis caused a reduction in larval numbers of
80, 93, 73% at the rate of 5.5 lb/ac and a reduction of 94, 93, 86% at the rate
of 10.6 lb/ac on days, 1, 3, 7 posttreatment, respectively. After treatment, the
reductions of bacterial densities in untreated tubs were greater than treated
tubs. These results indicate that mosquito larvae play an important role in the
decline of bacterial populations by their feeding activity.
PMID- 10672550
TI - Effects of neem products containing azadirachtin on blood feeding, fecundity, and
survivorship of Culex tarsalis and Culex quinquefasciatus (Diptera: Culicidae).
AB - When late 3rd or early 4th-instar larvae of Culex tarsalis Coquillett and Culex
quinquefasciatus Say mosquitoes were treated with sublethal dosages of neem
insecticide until pupation, the blood-feeding activity of the resulting adults
was essentially the same as that of untreated controls. In contrast, blood
feeding activity was suppressed when newly emerged adults were fed continuously
on 10 parts per million (ppm) or 50 ppm azadirachtin (AZ) in 10% sucrose solution
for seven days. Fecundity was also reduced by the various neem treatments. When
late 3rd or early 4th-instar larvae were treated with 0.010 ppm AZ to pupation,
the resultant females had a lower rate of oviposition than did the untreated
controls after a full blood meal. When late instar larvae were treated at 0.005
ppm and 0.010 ppm AZ, the resultant females produced smaller egg rafts after a
full blood meal, as compared to the controls, but egg viability was not affected.
In newly emerged adults feeding continuously on 10 ppm and 50 ppm AZ in 10%
sucrose for seven days (before blood feeding), the oviposition rate, size of egg
raft, and hatching rate of the eggs after a full blood meal were all reduced.
When newly blood-fed adults were fed continuously on 10 ppm and 50 ppm AZ in 10%
sucrose for five days, their oviposition rate was lower than controls in most
cases, but the egg raft size and viability of eggs were not affected. In freshly
blood-fed females topically treated with AZ with 1 or 5 micrograms/female, the
oviposition rate and size of egg rafts were generally reduced. The females
receiving topical treatment laid eggs and their hatching was not affected. The
longevity of adult females feeding continuously on 10 ppm and 50 ppm AZ in 10%
sucrose solution after emergence was reduced, whereas, the longevity of males was
only affected at the higher concentration.
PMID- 10672551
TI - Compatibility of Bacillus thuringiensis serovar israelensis and chemical
insecticides for the control of Aedes mosquitoes.
AB - The compatibility of the commercial aqueous Bacillus thuringiensis serovar
israelensis (B.t.i.) formulation, Vectobac 12AS, with the chemical insecticides
Actellic 50EC, Aqua Resigen, Resigen, and Fendona SC, for the simultaneous
control of Aedes larvae and adults was studied by dispersing nine different
formulations using a portable mist blower, in single story half-brick houses. The
effectiveness of the treatment was evaluated by measuring the larval mortality,
adult mortality, and droplet analysis at varying distances from the sprayer.
Persistence of the larvicidal activity of the chemical insecticides and B.t.i was
also determined by measuring the larval mortality in the test samples 7 days
posttreatment. The sprayed particles in all the trials were 50-60 microns in
size, indicating that the particles were those of mist spray. Test samples placed
within 3 m from the sprayer gave the maximum larval and adult mortality. Chemical
insecticides exhibited maximum larval mortality in the 1 h posttreatment test
samples and it was comparable to the larvicidal activity of B.t.i. The larvicidal
toxins of B.t.i were more stable and were able to affect sufficient larval
mortality for 7 days posttreatment. The larvicidal activity of the mixtures,
i.e., chemical insecticides with B.t.i, in the 1 h posttreatment test samples was
not significantly different from the larvicidal activity of the chemical
insecticides and it was comparable to the larvicidal activity of B.t.i alone.
However, the larvicidal activity of the mixtures was significantly more than the
chemical insecticides alone in the 7 days posttreatment test samples except for
the Actellic 50EC and Vectobac 12AS mixture. In all the trials, with or without
B.t.i, there was no significant difference in adult mortality, indicating that
this B.t.i formulation, Vectobac 12AS, was not antagonistic to the adulticidal
activity of the chemical insecticides. From this study, it can be concluded that
chemical insecticides can be used effectively for both adult and larval control,
but the chemical insecticides do not exhibit residual larvicidal activity. Hence,
for an effective control of both Aedes larvae and adults, it is advisable to add
B.t.i. to the chemical insecticides, as B.t.i is specifically larvicidal and is
also able to effect extended residual larvicidal activity.
PMID- 10672552
TI - Ticks of South Carolina (Acari: Ixodoidea).
AB - County and host records are reported for 19 species of ticks from South Carolina:
Amblyomma americanum, Amblyomma maculatum, Amblyomma tuberculatum, Aponomma
latum, Boophilus annulatus, Boophilus microplus, Dermacentor albipictus,
Dermacentor variablis, Haemaphysalis leporispalustris, Ixodes affinis, Ixodes
brunneus, Ixodes cookei, Ixodes marxi, Ixodes minor, Ixodes scapularis, Ixodes
texanus, Ixodes woodi, Rhipicephalus sanguineus, and Ornithodoros capensis.
Ixodes woodi is recorded from South Carolina for the first time. Boophilus
annulatus and Boophilus microplus probably no longer exist in South Carolina, and
Aponomma latum is an exotic species that is not established in South Carolina.
Brief notes follow each species.
PMID- 10672553
TI - [Seasonal variations in stroke incidence in North-Eastern Poland].
AB - The authors analysed seasonal and monthly incidence of and mortality from
ischaemic stroke (IS) in the region of Bialystok (North-Eastern Poland). 839
cases of IS (437 men and 402 women), aged 22 to 94 years, were hospitalised in
the Department of Neurology, Medical Academy in Bialystok during the analysed
period (1990-1997). Significant seasonality in IS incidence was observed in both
sex groups, with a nadir in summer. The lowest occurrence of infarcts was
observed in August in women, and in June in men. The peak month for IS,
independently of sex, was January. 240 patients (28.6%) died of stroke or its
complications during the analysed period. The occurrence of fatal IS followed
also a clear seasonal pattern with peak in autumn. The authors attempt to explain
this seasonal incidence and mortality pattern of IS in relation to variation in
temperature, diet, way of life (holidays in summer), and biochemical blood
changes, which occur in different seasons of the year.
PMID- 10672554
TI - [Clinical significance of oxidation and acetylation genetic polymorphism in
patients with Parkinson's disease].
AB - The relationship between genetically determined polymorphic oxidation and
acetylation and susceptibility to some disease has aroused much interest. The aim
of our study was to evaluate whether patients with Parkinson's disease differ
from healthy persons in their ability to oxidize sparteine and acetylate
sulfadimidine as model drugs. Oxidation and acetylation phenotypes were estimated
in 50 patients with Parkinson's disease. The control group consisted of 160
healthy volunteers for comparison of oxidation phenotype and 60 healthy
volunteers for comparison of acetylation phenotype. The phenotyping of oxidation
revealed two distinct populations among 50 patients with Parkinson's disease: 47
persons (94%) were extensive metabolizers of sparteine and 3 persons (6%) were
poor metabolizers. In 160 healthy persons, 146 persons (91.2%) were extensive
metabolizers of sparteine and 14 persons (8.8%) were poor metabolizers. The
difference between frequency distribution of PMs and EMs in healthy persons and
in patients with Parkinson's disease was not statistically significant. The
phenotyping of acetylation showed among 50 patients with Parkinson's disease 38
persons (76%) slow acetylators and 12 persons (24%) rapid acetylators. In 60
healthy volunteers the phenotype of slow acetylation was observed in 29 persons
(48.3%) and rapid acetylation in 31 persons (51.7%). The prevalence of slow
acetylators among patients with Parkinson's disease in comparison to healthy
volunteers was statistically significant (chi 2 = 8.7677/p < 0.003). The results
of our study may suggest that the slow acetylation phenotype is associated with
increased risk of the development of Parkinson's disease.
PMID- 10672555
TI - [Increased expression of aminopeptidase N on lymphocytes in multiple sclerosis].
AB - Aminopeptidase N is an ectoenzyme. Its expression on lymphocytes is the effect of
cell activation. We studied APN expression on peripheral blood lymphocytes of
multiple sclerosis (MS) patients and in the control group of patients with other
neurological diseases (OND). We observed increased APN expression on lymphocytes
of MS patients during acute exacerbation and in the course of chronic progressive
MS compared to MS remission and OND groups. No such differences were found in
CD11a molecule of LFA-1 integrin expression on lymphocytes. We suppose that APN
expression on lymphocyte surface can be a sensitive marker of these cell
activation in the course of MS.
PMID- 10672556
TI - [Pineal cyst in MRI: clinical symptoms and analysis].
AB - Application of magnetic resonance imaging (MRI) in radiology allows to estimate
and analyse pineal gland and pineal region pathology more precisely. We report 47
MRI brain studies of patients in whom pineal cyst was recognized as the only
pathologic finding. MRI of the brain was performed because of clinical symptoms
as headaches (32%), vertigo (26%) and altered behaviour (13%). Because of the
common occurrence of pineal cyst in MRI brain imaging it seems to be important to
decide whether these patients need neurosurgical intervention, especially if
together with morphologic abnormality definite clinical symptoms exist.
PMID- 10672557
TI - [Recording of vestibular myogenic evoked potentials in patients with disturbed
inner function].
AB - In this study, we measured VEMP in patients with disturbed function of inner ear.
We studied 4 patients with unilateral sensorineural deafness and normal
excitability of vestibular organs; 6 persons with unilateral weakness of
vestibular function and 10 healthy subjects. We found that in patients with
unilateral weakness of vestibular function VEMPs had short latencies and
diminished amplitudes whereas in patients with unilateral deafness VEMPs were
unchanged. These data strongly suggested that VEMPs were generated by stimulation
of vestibular and not cochlear part of inner ear-sacculus. Our data confirm that
VEMPs are a highly objective technique, simple, secure and comfortable for
patients to assess the vestibulo-spinal connections.
PMID- 10672558
TI - [Results of postoperative treatment of patients after brain tumor removal based
on the cerebral circulatory pressure index (CCPI) in comparison with ICP and
CPP].
AB - The aim of the study was the assessment of prognostic value of CCPI in relation
to the results of treatment of patients with increased intracranial pressure
after brain tumour operative treatment. The results of treatment of 107 patients
with intracerebral tumours according to neurological state at the introduction of
treatment (GCS) and initial values of ICP, CPP and CCPI as well as final results
of treatment (GOS) are analysed. A special normogram collecting all of these
parameters was constructed, as well as the directions of treatment depending on
the areas of MABP, ICP and CPP were established. The CCPI seems to be more a
sensitive and earlier signals suggesting the urgency and the direction of
treatment than ICP and especially CPP alone. There seems to be a great
consistence of the patient state evaluation according to GCS, GOS and CCPI which
is also a prognostic factor. All the patients with initial CCPI below 1.5 died
while all the patients with CCPI over 3.0 in good and very good neurological
state, and all the patients with initial CCPI between 1.5 and 3.0 had
neurological deficits.
PMID- 10672559
TI - [Analysis of own clinical material treated by conservative and aggressive control
of intracranial hypertension].
AB - These problems arising during the treatment of increased intracranial pressure
(ICP) were analysed on the basis of own clinical material with consideration of
different therapeutic methods--pharmacological and aggressive. Statistical
analysis (contingency tables) showed that the treatment consisting of
dexamethason, mannitol and furosemid was the most efficient in the group of
patient with increased ICP in the range 15-30 mmHg. In patients with ICP in the
range 30-50 mmHg, where other aggressive methods of treatment had failed, the
most efficient treatment was cranio-dural decompression.
PMID- 10672560
TI - [The proliferative potential of human pituitary macroadenomas on the basis of
morphometric analysis of nucleolus organizer regions].
AB - Cell kinetic information is an important adjuvant to histological typing and
grading of human brain tumours. In the current study detection of the
proliferating potential of adenomas was attempted using silver colloid technique
for argyrophilic protein associated with nucleolar organizer regions (AgNORs).
The expression of nucleolar organizer regions was assessed on paraffin sections
in 28 pituitary macroadenomas which included all the main types. Nucleolar
organiser regions have been quantified with computer-aided image analysis system
in order to evaluate the mean area of AgNORs and their number relative to an
internal reference, the number and areas of clusters of AgNORs and the area of
the nucleus. In the pituitary macroadenomas there were 1.48 +/- 0.30 (mean +/-
SEM) AgNORs per cell nucleus and corrected values were 1.66 +/- 0.27 (mean +/-
SEM) AgNORs. The mean nucleus area was 867.18 +/- 203.91 pixels. The mean AgNORs
size was 54.50 +/- 34.80 pixels. Correlation of nucleus area/AgNORs area was: r =
0.7085. On the number of the AgNORs it was possible to distinguish 3 subgroups of
macroadenoma with different proliferative potential: low < = 1.367 (1.479);
medium 1.367-1.733 (1.479-1.864) and high > 1.733 (1.864) AgNORs per cell nucleus
and corrected number of AgNORs per cell nucleus respectively. Thus, this method
provides useful information about the proliferative potential of human pituitary
adenoma.
PMID- 10672561
TI - [Dynamics of blood flow velocity in middle cerebral arteries in dyslexic
persons].
AB - The aim of our study was to investigate the blood flow in middle cerebral
arteries during the different forms of cognitive activity in dyslectic persons.
Two group of subjects were tested. The first group consisted of 10 students with
school difficulties, diagnosed neuropsychologically as having a particular form
of dyslexia, i.e. dysgraphy or dysorthography. 6 of them were right lateralized
and 4--left lateralized. The second contained 10 students without such problems.
7 of them were right lateralized and 3--left lateralized. We used four kinds of
cognitive tasks, during which the blood flow velocity in MCA in left and right
hemisphere was measured with the Transcranial Doppler method. The analysis of the
results showed differences between the groups of blood flow velocity levels,
without a difference in performance profile. The dysgraphic persons had
significantly higher blood flow velocity in the right hemisphere compared to the
reference group. The results suggest particularly important role of right
hemisphere in dyslexic persons, which is consistent with results obtained by
other authors. The analysis of lateralization showed that this factor influences
significantly the blood flow velocity level--the left lateralized persons showed
lower rise of blood flow velocity than the right lateralized, regardless of the
kind of task and measured hemisphere.
PMID- 10672562
TI - [Clinical autosomal dominating arteriopathy with subcortical infarcts and
leukoencephalopathy (CADASIL)].
AB - CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and
leukoencephalopathy) is a diffuse disease of small arteries, predominating in the
brain. It starts during mid-adulthood and is characterized by recurrent ischaemic
events (transient or permanent), attacks of migraine with aura, severe mood
disorders, subcortical dementia and at MRI white periventricular
leukoencephalopathy. CADASIL is an autosomal dominant disease. The gene Notch3 on
which the mutation was detected is located on chromosome 19. There is so far no
specific treatment and death occurs after a mean of twenty years.
PMID- 10672563
TI - [Radiological evaluation of pineal pathology and its regions].
AB - Contemporary neuroimaging procedures facilitate the differential diagnosis of
pineal region pathology. They are of particular importance in malignant pineal
tumours which may have non characteristic clinical presentation. Computed
tomography and magnetic resonance imaging with intravenous infusion of
paramagnetic contrast allow to determine tumour size and localization as well as
its morphologic features and growth dynamics. The diagnosis obtained is a valid
basis for treatment strategies.
PMID- 10672564
TI - [Neuropsychological rehabilitation of patients with cognitive function
disturbances in organic brain damage].
AB - A new neuropsychological method of rehabilitation of brain-injured patients with
cognitive disorders is presented in the paper. The so called cognitive
rehabilitation is based on computer programmes, prepared for typical syndromes of
cognitive disorders. Research studies in this review refer to the effectiveness
of that kind of therapy, indicating its confirmed values and some aspects to be
explained yet.
PMID- 10672565
TI - [Fixating techniques of craniocervical junction: selection criteria].
AB - Adequate choice of fixation technique at craniocervical junction depends on many
factors: anatomical conditions at fusion site (e.g. anterior dislocations of the
odontoid and rupture of the transverse ligament are contraindications for direct
odontoid screw fixation. Sublaminar wiring and interlaminar clamps are useless in
case of deficiency of posterior bony elements of C1 and C2 whether a result of
laminectomy or destruction), bone quality (osteopenic bone is contraindication
for screw techniques either transarticular or transpedicular). Enclosing of
occipital bone into instrumentation may be difficult in wire and clamping
techniques. In contrast screw techniques allow for easy grip the occipital bone.
Screw techniques seem ideal in cases requiring enclosing of the occipital bone.
The fusion rate at C1/C2 level seems independent of fixation techniques. When
supplemented with external immobilization even biomechanically inferior wiring or
interlaminar clamping provide nearly 100 rate of fusion. Screw techniques are
technically demanding but they seem the method of choice when occipital bone is
to be enclosed in instrumentation.
PMID- 10672566
TI - [Sequence of clinical changes and evolution of MR images in a case of chronic
SSPE].
AB - Slow course case of subacute sclerosing panencephalitis is reported. The onset
was at the age of 16 years and death followed after 5 years. He was observed
during nine successive hospitalizations and the authors describe the changing
clinical symptomatology parallelly with successive EEG records and brain MR
imaging evolution. Successive phases of the disease were associated with
hyperintense changes in T2-weighted.images, and were situated initially in
occipital lobes, and involved later on periventricular areas and finally the
whole white matter of both cerebral hemispheres. Subcortical brain atrophy
developed parallelly.
PMID- 10672567
TI - [Adrenomyeloneuropathy: a form of X-linked adrenoleukodystrophy. Report of a
family].
AB - A family with adrenoleucodystrophy linked to chromosome X (X-ALD) is reported.
Three patients, one man (proband) and two female monozygotic twins, had
adrenomyeloneuropathy (AMN) which is a form of the disease. The proband had
characteristic changes in MRI with demyelination of the white matter in the
cerebral hemispheres. Both women (one of them was proband's mother) has somewhat
less severe AMN form, but in her twin sister the syndrome was much more intense.
The clinical diagnosis of the disease was confirmed by biochemical investigations
-determination of the level of very long chain fatty acids, ALDP protein and the
activity of peroxysomal beta-oxidation.
PMID- 10672568
TI - [Cervical pain as the only complaint in a patient with metastatic advanced lung
carcinoma (case report)].
AB - Description of a case of metastatic advanced squamous cell lung carcinoma without
any symptoms of the original focus. The only complaint of the patient almost
throughout the course of the disease was cervical pain. Despite fast clinical
course of the disease considerable adaptation of spinal cord to compression by
metastatic focus in the vertebral column, may occur. Also numerous metastatic in
bones or large foci in suprarenal glands may remain silent for a longer time of
the disease. Examinations carried out: bons scinticsanning, CT of the abdominal
cavity and MRI of cervical spine allowed to suspect that process with great
probability, what was confirmed by autopsy.
PMID- 10672569
TI - [Hemicrania continua: a case report].
AB - Hemicrania continua is a rare idiopathic headache of unknown etiology. The
clinical course is characterized by usually unilateral, continuous headache.
There are some clinical variants of pain character and other symptoms.
Indomethacin (50-150 mg per day, rarely higher) leads to complete remission in
all patients. Current diagnostic procedures (including neuroimaging) should be
recommended in all cases to exclude organic cause of headache. The authors report
a case of a 46-year old woman with 3 years history of drug resistant, unilateral
headache. Complete remission after administration of indomethacin (75 mg TID) was
achieved. Problems of diagnostic, clinical course and treatment of hemicrania
continua are discussed.
PMID- 10672570
TI - [Trans-sternal approach to the cervicothoracic junction].
AB - Cervicothoracic junction and upper thoracic spine down to T4 can be reached
through anterior approach via sternotomy. Transsternal approach is the best route
to gain access to lesions localized within vertebral bodies of the upper thoracic
spine allowing for their resection, interbody fusion and replacement with bone
cement. Consecutive modifications of transsternal approach evolved toward less
extensive osteotomy from full median sternotomy, through manubriotomy with
clavicle resection and partial lateral manubriotomy. Less extensive modifications
provide limited lateral exposure of the spine and are more demanding technically.
We present two cases of upper thoracic spine tumours operated on through full
medial sternotomy. We believe that median sternotomy has several advantages over
less extensive modifications: it is technically simple to perform for trained
thoracic surgeon, safer as it provides better exposure of the mediastinum and
thus sufficient control of great vessels including subclavian ones, gives better
exposure of T3, T4 and even T5 vertebral bodies, allows perpendicular sight and
attack to anterior surface of the upper thoracic spine and therefore good
visualizing of the posterior longitudinal ligament and dura, do not destabilize
shoulder girdle nor affect function of the upper limb. Additional caudal exposure
of the thoracic spine as down as T5 can be obtained by dissecting a plane between
the brachiocephalic vein, vena cava superior and ascending aorta.
PMID- 10672571
TI - [Instability of atlanto-axial complex in a boy with isolated odontoid process].
AB - The authors present a case of a 14-years old boy, in whom, after a mild trauma,
massive signs of cervical spinal cord injury appeared. Isolated odontoid process
with instability of atlanto-axial complex proved to be the cause. In course of
therapy with methylprednisolone and rehabilitation full recovery was achieved.
The operative management consisted in posterior interlaminar stabilization C1-C2
with autologous bone transplant and titanium cable (Sof'wire). The etiology of
this disturbance is discussed and operation method is presented.
PMID- 10672572
TI - [Obituary to Professor Henryk Wisniewski].
PMID- 10672573
TI - [Report from the XVth day of child neurosurgery in Poznan on the topic of
"Neonatal neurosurgery" (March 8, 1999)].
PMID- 10672574
TI - Hydrocephalus enters the new millennium: an overview.
PMID- 10672575
TI - The CSF accumulator.
AB - The ability of the central nervous system (CNS) to store and release fluid energy
plays an important role in both health and disease. The stored fluid energy is
the product of the fluid volume and pressure. How changes in CNS fluid (CSF,
blood, or extracellular fluid) energy are distributed is determined by the
compliance of the fluid containers and their arrangement. Hydrocephalus and
related diseases not only interfere with the absorption of CSF but also interfere
with the exchange of CSF in response to positional changes, cardiorespiratory and
intraperitoneal energy changes. While shunts allow for the diversion of CSF when
the intracranial energy exceeds the absorbing receptacle energy, they do not
normalize the return of CSF to the intracranial compartment as needed with the
intracranial blood volume or pressure decreases (the accumulator function of the
CNS's CSF). A CSF shunt that has an artificial accumulator proximal to the valve
can potentially restore the accumulator function towards normal and prevent some
of the complications associated with CSF overdrainage.
PMID- 10672576
TI - Brain biomechanics: mathematical modeling of hydrocephalus.
AB - The considerable amount of literature on mathematical models of hydrocephalus and
other brain abnormalities is critically reviewed. These models have various
degrees of mathematical sophistication, and have influenced not only the
diagnosis of hydrocephalus, but also its treatment with CSF shunts. The
mathematical models are classified into two classes, pressure-volume models, and
consolidation models. Advantages and disadvantages of both types are pointed out
with a view to removing the confusion frequently generated by the technical
aspects of the subject. The conclusion is reached that, while none of the current
models are good enough to be of immediate use to the neurosurgeon, mathematical
models are likely in the future to be a powerful tool for the understanding and
the treatment of hydrocephalus, as well as other conditions related to brain
biomechanics. The amount of mathematics has been kept to the absolute minimum,
but it is cited and appended for those who would like to dig further into this
fascinating area of research.
PMID- 10672577
TI - Post-traumatic hydrocephalus.
AB - The syndrome of post-traumatic hydrocephalus (PTH) has been recognized since
Dandy's report in 1914. The incidence of symptomatic PTH ranges from 0.7%-29%. If
CT criteria of ventriculomegaly are used the incidence has been reported to be
from 30%-86%. Differences in diagnostic criteria and classification have
contributed to the variation in reported incidence. The diagnosis of PTH is
established using a combination of clinical, imaging and physiologic data.
Symptomatic PTH is to be distinguished from post-traumatic ventriculomegaly
resulting from atrophy. Symptomatic PTH patients are likely to improve when
treated by shunting. Ventriculomegaly secondary to atrophy is less likely to
respond to shunting. A series of traumatic brain injury patients at Wayne State
University has been followed since 1989. The overall incidence of shunt placement
in this group is 3.65%. Future studies of PTH should be aimed at refining
diagnostic classification and criteria. Analysis of a large PTH population may
then identify alterable risk factors in the early post-traumatic brain injury
period. Minimizing these factors will help prevent subsequent PTH and obviate the
need for shunting.
PMID- 10672578
TI - Pathology of the hippocampus in experimental feline infantile hydrocephalus.
AB - Hydrocephalus is responsible for many pediatric neurological deficits presumed to
be caused by neocortical pathophysiology. Relatively little is known about the
role of non-neocortical CNS structures in this condition. In the present work
experimental infantile hydrocephalus produced by intracisternal kaolin injection
was studied in a neonate kitten model. The hippocampal formation was processed
for electron microscopy, and the neuropil of the CA3 region was examined in
untreated, severely hydrocephalic and age-matched normal animals. Both
macroscopically and microscopically the thickness of the hippocampus was not
decreased. Hippocampal pyramidal neurons were found in varying stages of
cytoplasmic densification, and dendritic and axonal processes exhibited hydropic
cellular deterioration. The number of synaptic contacts was decreased. However,
there was no indication of edematous extracellular space and the ependymal
covering of the hippocampus was intact. The macroscopic structural integrity of
the hippocampus, as well as the dendritic, axonal and synaptic alterations,
suggest that the dark pyramidal neurons are the result of deafferentation, which
may have profound effects on learning and memory.
PMID- 10672579
TI - Pre-natal ventriculomegaly and hydrocephalus.
AB - Ultrasonic imaging of the human fetal brain has allowed ventriculomegaly and
hydrocephalus to be categorized. In this study 40 fetuses with ventriculomegaly
and 21 with an Arnold-Chiari malformation and a myelomeningocele had
ventriculomegaly that resolved, stabilised or progressed in utero. Within the
progressive group were those with hydrocephalus, hydrocephalus being defined as
expansion of the cerebral ventricular atria together with disproportionate
increase in the head circumference. The prognosis for fetuses with resolving and
stable ventriculomegaly was good, reflecting the fact that the ventricular
dilatation in these cases was probably caused by delayed parenchymal and
cerebrospinal fluid pathway development. Whereas the prognosis for progressive
ventriculomegaly was generally poor, suggesting that the causes were likely to
have been chromosomal, genetic, an infective agent or a catastrophic event which
had an adverse effect on parenchymal development. The causes of hydrocephalus
also adversely affected brain development but additional damage was caused by
raised intracranial pressure.
PMID- 10672580
TI - Cerebrospinal fluid flow through an implanted shunt.
AB - Although the circulation of cerebrospinal fluid enjoys an apparent simplicity,
its underlying basis is amazingly complex. Many factors influence how CSF flows
through the human central nervous system. In the presence of hydrocephalus and
subsequent shunt placement, this system is further complicated. The challenge
before us then is to advance our understanding of the mechanisms that underlie
CSF circulation, to place within that context the implications of shunt
dependency, and to design a shunt system capable of simultaneous redirection of
CSF and restoration of the CNS toward normal. Such a new shunt system would have
to overcome not only those complications that result from hydrocephalus, but also
those that result from the shunt's very placement. The purpose of this
publication is 1. to provide an overview of the CSF circulatory system in the
context of hydrocephalus and shunt dependency; 2. to explore resultant
complications within the framework of those factors that influence CSF
circulation within the human biological system as well as those that arise from
the factors that influence CSF flow through a shunt; and 3. to propose in brief
an alternative shunt valve designed to restore the accumulator function of the
CNS toward normal.
PMID- 10672581
TI - NMR spectroscopic evaluation of cerebral metabolism in hydrocephalus: a review.
AB - Cerebral ischemia contributes to cerebral damage in hydrocephalus. Many studies
have reported changes in cerebral blood flow and metabolism, supporting this
hypothesis. Magnetic resonance spectroscopy (MRS) enables us to investigate
cerebral metabolism in a non-invasive and longitudinal manner, thereby providing
a promising way of evaluating pathophysiological changes in experimental and
clinical hydrocephalus. In this review, the potential of 1H (proton) and 31P
(phosphorus) MRS in the assessment of cerebral metabolism will be summarized, and
a synopsis of in vitro and in vivo MRS studies in experimental and human
hydrocephalus will be presented. Changes in high-energy phosphate metabolism,
intracellular pH and lactate production in several MRS studies are presumed to
reflect cerebral ischemia. In vivo information on neuronal damage, maturational
delay and membrane phospholipid metabolism may also be derived from 1H and 31P
MRS data. Technical, methodological and pathophysiological considerations, which
are important for a correct interpretation and comparison of different MRS
studies, will be discussed. Finally, we will draw some conclusions on the
significance of these MRS findings and the applicability of MRS in the diagnosis
and evaluation of clinical hydrocephalus.
PMID- 10672582
TI - The initial treatment of hydrocephalus: an assessment of surgeons' preference
between third ventriculostomy and shunt insertion.
AB - Third ventriculostomy is an option for patients who have traditionally received a
ventriculoperitoneal shunt. This study has been conducted to determine: 1. How
common is third ventriculostomy as the initial treatment of hydrocephalus? 2.
Does the frequency of third ventriculostomy vary among surgeons? 3. What factors
influence surgeons' decision to choose third ventriculostomy? Surgeons completed
a questionnaire addressing patient selection and technique factors. Nine case
scenarios were reviewed by surgeons who were then asked to choose a
ventriculoperitoneal shunt or a third ventriculostomy as the initial treatment.
Forty-three responses were received. The proportion of new patients treated with
third ventriculostomy varied widely (0%-100%, median 13%). This was not related
to years in practice, type of training or presence of residents/fellows. Factors
that increased the chance of a third ventriculostomy were triventricular
hydrocephalus on CT/MR, isolated aqueduct stenosis, thin ballooned floor and
tectal tumor. Factors that decreased the chance of a third ventriculostomy were
dilated subarachnoid spaces, meningitis and head injury. The presence of
myelomeningocele or age < 1 year were less likely to influence the choice of
operation. Variation in the rate of third ventriculostomy as the first treatment
for hydrocephalus is large. It is unlikely that this degree of variation can be
explained by differences in patient populations. Further work to refine and
disseminate the indications for third ventriculostomy is warranted.
PMID- 10672583
TI - Hydrocephalus and the reproductive health of women: the medical implications of
maternal shunt dependency in 70 women and 138 pregnancies.
AB - An increasing number of women with cerebrospinal fluid shunts are surviving to
child-bearing age, and are making independent decisions in regard to planning
their families. As a result, a broad range of interdisciplinary health care
professionals will require information about the management of these patients,
especially during pregnancy and delivery. The purpose of this ongoing study is to
gather comprehensive data from shunted women regarding their clinical history
during pregnancy and within the six-month post-partum period. As part of this
study, the following questions were addressed: 1. How does maternal shunt
dependency influence the course of pregnancy and pregnancy outcomes? 2. What
neurosurgical complications characterize this population of patients? 3. What
complications of shunt dependency influence obstetrical management including pre
natal testing and delivery? 4. What are the implications of shunt dependency with
respect to general reproductive health concerns within this population? A total
of 70 respondents, 18-41 years old and accounting for 138 pregnancies, completed
a questionnaire providing information on maternal background, medical history,
shunt performance during pregnancy, management of delivery, pregnancy outcomes,
and unusual complications. One hundred three (103) pregnancies resulted in 105
live births including two surviving sets of twins; of these, 84 occurred in women
with ventriculoperitoneal shunts (including both mothers who gave birth to live
twins). Four women underwent therapeutic abortions, five delivered pre-term, one
mother delivered a stillborn infant, and 16 experienced 32 miscarriages
(including two ectopic pregnancies, and 33 fetal losses). Three women had
seizures during pregnancy. Nine mothers reported an increase in headache activity
during pregnancy. Twelve described abdominal pains during the course of pregnancy
with anecdotal reports of increased frequency of painful episodes during the
first and third trimesters. Twelve babies were diagnosed with congenital defects,
including one pair of fraternal twins individually diagnosed with symmetric
parietal foramina. Seven additional children were diagnosed with developmental
disabilities including attention deficit disorder (ADD), attention deficit
hyperactivity disorder (ADHD), pervasive developmental delay (PDD), and autism.
Shunt malfunctions and revisions occurred seven times (four women) during
pregnancy, and in 24 pregnancies (13 women) within six months of delivery. One
malfunction and revision followed the miscarriage of twins at 12 gestational
weeks. No acute malfunctions requiring immediate revision occurred during
delivery, although two women reported severe headaches during labor. Transient
signs of raised intracranial pressure occurred in 15 mothers over the course of
19 pregnancies which did not require surgical revision of the shunt following
delivery or termination of pregnancy. No signs of shunt malfunction were
identified in 100 of the pregnancies described in this series; 31 of these
resulting in miscarriage and 69 resulting in live births. This study extends
observations made previously to a larger population of shunt dependent mothers,
and nearly doubles the amount of data available in our last publication. The
results suggest that maternal shunt dependency carries a relatively high
incidence of complications for some patients, but that proper management of these
patients can lead to normal pregnancy and delivery.
PMID- 10672584
TI - Progressive tissue injury in infantile hydrocephalus and prevention/reversal with
shunt treatment.
AB - Infantile hydrocephalus, despite shunt treatment, can leave children with a
variety of persistent neurological deficits. A rat strain (H-Tx) with inherited
fetal-onset hydrocephalus, is a natural model for the study of progressive tissue
changes resulting from hydrocephalus and the effects of shunt placement. The
cerebral cortex of rat pups has been studied at post-natal day 4 (P4), early
stage hydrocephalus and equivalent to a third trimester human fetus, at P11,
intermediate stage hydrocephalus and equivalent to a newborn human infant, and at
P21 at advanced stage hydrocephalus. At P4, there is interstitial edema
(increased water, sodium and chloride) and a non-reversible change in membrane
lipids, particularly the phosphomonoesters. By P11, there are additional, non
reversible, changes in intracellular potassium and energy metabolites (ATP and
phosphocreatine). At P21, the cells are severely damaged and further
intracellular changes include a decrease in N-acetylaspartate (NAA) and loss of
amino acids and many organic osmolytes. The interstitial edema is approximately
75% reversed after shunt treatment. The loss of energy metabolites, NAA and
osmolytes can be prevented by early shunt treatment at P4, but the subsequent
potassium loss is not prevented. Shunt at P11 does not prevent loss of NAA or
aspartate, but osmolytes are normalized. It is concluded that persistent tissue
damage is initiated by changes in cell membrane components leading to a decrease
in energy metabolism and loss of cell homeostasis. A more complete understanding
of the mechanisms involved could lead to new approaches for therapy.
PMID- 10672585
TI - Hydrodynamic principles in hydrocephalus: the engineer's perspective.
AB - There have been significant improvements in the prognosis for patients suffering
from hydrocephalus stemming from the introduction of the cerebrospinal fluid
(CSF) shunt some 40 years ago. Currently, one of the major obstacles to effective
shunt treatment is the mismatch between the physiology of the patient and the
hydraulics of the shunt system. In order to maintain the proper relationship
between CSF and cerebrovascular pressures, the implanted shunt needs to establish
normal CSF outflow (absorption) and storage (compliance). Many of today's shunts
establish a limited range of normal CSF outflow (absorption) and storage
(compliance) once implanted, but a mismatch between CSF and cerebrovascular
pressures may exist when the patient changes body position during daily
activities. An uncoupling of these pressures creates mechanical strains within
cerebral tissues, which are implicated in pathologies related to shunt
malfunction. We suggest that re-establishment of normal CSF outflow resistance,
which by definition is an indicator of both absorption and compliance, is a
fundamental requirement for shunt treatment under most conditions.
PMID- 10672586
TI - Fibroblast growth factor and hydrocephalus.
AB - The immunohistochemical localization of basic fibroblast growth factor (bFGF) was
studied in ventricular ependyma and choroid plexus of aged-matched normotensive
and spontaneously hypertensive rats at different ages using a polyclonal antibody
against bFGF. The bFGF-like immunoreactivity was observed in brain ependyma and
choroid plexus of young and old normotensive rats. However, a progressive loss of
immunoreactivity was observed with age in spontaneously hypertensive rats, that
was associated with a progressive cerebroventricular dilation. These results show
a new neuroendocrine anomaly to be added to the many others previously observed
in this rat strain, when they develop hydrocephalus as they age.
PMID- 10672587
TI - The living shunt: a tissue engineering approach in the treatment of
hydrocephalus.
AB - Tissue engineering is the use of cultured cells seeded into biodegradable
polymers to create custom designed, living implantable devices. As a first
approach to the use of this technique in the treatment of hydrocephalus, we have
prepared chondrocyte-seeded polyglycolic acid (PGA) tubes coated with polylactic
glycolic acid (PGLA), implanted initially with thin silastic stents removed four
weeks after shunt insertion. The use of bovine xenograft cells in athymic (nude)
rats resulted in more efficient seeding with chondrocytes, stiffer tube walls,
and better patency. When implanted in 6-week-old rats made hydrocephalic by
cisternal injection of kaolin at 4 weeks of age, six of eight 'living shunts'
remained patent to radio-opaque contrast injection at two weeks after stent
removal. At four weeks after stent removal, all four of the shunts had occluded
at the ventricular end, three of the four apparently due to growth of the animal.
We conclude that polymer type, cell type, and cell density will require
considerable optimization, but a working tissue engineered shunt is feasible and
may one day address some problems of interactions of living tissue and inert
polymer.
PMID- 10672588
TI - Magnetic resonance imaging study of extracellular fluid tracer movement in brains
of immature rats with hydrocephalus.
AB - Hydrocephalus is associated with brain compression and accumulation of
neurotransmitter waste products in the brain and cerebrospinal fluid. We
postulated that the extracellular compartment is compressed and specifically
hypothesized that extracellular fluid tracer movement through brain would differ
between control and hydrocephalic rats. Gadolinium diethylenetriamine pentaacetic
acid (Gd-DTPA) was injected into the cerebral cortex of 4-week-old rats, 7-11
days after induction of hydrocephalus by kaolin injection into the cisterna
magna. The movement of this soluble paramagnetic compound was followed over
successive timed intervals from 20 min to 180 min with T1-weighted magnetic
resonance imaging. Non-hydrocephalic controls exhibited greater spread of the
tracer and greater change in T1-weighted signal intensity in the ipsilateral
cortex than hydrocephalic animals. Hydrocephalic animals exhibited preferential
accumulation of tracer in edematous white matter. Gd-DTPA penetrated the lateral
ventricles within 30 min in both control and hydrocephalic rats. The results
suggest that there is a relative impairment of extracellular fluid movement
through the cerebral cortex of young hydrocephalic rats.
PMID- 10672589
TI - Genetic and embryological approaches to studies of neural tube defects: a
critical review. NTD Collaborative Group.
AB - Experimental embryological models have suggested that the morphology and quantity
of neural tube defects may be governed by their position along the
anteroposterior axis of the embryo. Inductive interactions and genetic regulation
during axis development may play a role in the patterning of neural tube defects.
A major challenge in the study of human neural tube defects is determining
whether the spectrum of developmental neural tube anomalies found in individuals
and their families mirror experimental models and are regulated by similar
processes. We have found that the various neural tube defect phenotypes can be
clustered according to their position along the anteroposterior axis. The
findings correlate well to the pattern of early genes expression, inductive
models of the embryonic axis, and mutant NTD animal models. We suggest that NTD
should be studied by their location along the anteroposterior axis and that
specific mutant genes may be identified by the observed pattern of NTD in an
individual or a family.
PMID- 10672590
TI - A brief review of the effects of chronic hydrocephalus on the gonadotropin
releasing hormone system: implications for amenorrhea and precocious puberty.
AB - Precocious puberty and amenorrhea have been associated with hydrocephalus, but
the pathogenesis has not been determined. Approximately 22 cases of amenorrhea,
and a few cases of precocious puberty, have been reported in hydrocephalic
patients. Shunt treatment leads to initiation and maintenance of normal
reproductive cycles in most cases. An underlying mechanism responsible for
reproductive dysfunction may involve the role of gonadotrophin releasing hormone
(GnRH). The exact pathway by which hydrocephalus disrupts the hypothalamic GnRH
system is unknown. However, compressive forces, ischemia, and impairment of
neurotransmitter feedback loops are likely candidates.
PMID- 10672591
TI - Actualities in hydrocephalus classification and management possibilities.
AB - Retrospective analysis in co-operative study of hydrocephalus at institutions of
members of the Research Committee on Intractable Hydrocephalus sponsored by the
Ministry of Health and Welfare of Japan was performed to determine the functional
prognosis. For clinico-epidemiological study we classified non-tumoral
hydrocephalus into eight types based on its etiology and the time of onset.
Analysis of the 1,450 cases of hydrocephalus stored in the database obtained from
the study was performed in order to find intractable factors in terms of factors
related to patients and management. Analysis of the cases stored in the database
revealed that the following types and conditions were found to be intractable
factors: 1. Early fetal hydrocephalus. 2. Overt neonatal hydrocephalus. 3.
Hydrocephalus associated with such severe brain malformations as hydranencephaly,
holoprosencephaly and lissencephaly. 4. Hydrocephalus associated with severe
brain damage. 5. Hydrocephalus associated with epilepsy. 6. Hydrocephalus shunted
late after detection. 7. Hydrocephalus complicated by a shunting operation. It is
impossible to determine prior to treatment whether or not a shunting operation is
indicated for the patient with intractable factors, however, they may be a useful
pre-operative indicator of prognosis. For the management of hydrocephalus,
secondary intractable hydrocephalus may be preventable if we treat it
appropriately before it becomes intractable.
PMID- 10672593
TI - [The 1998 domestic state of development of cognitive enhancers].
AB - Recently, there is a great social problem that geriatric disorders, especially
senile dementia, are growing rapidly with the increasing percentage of aged
individuals in the total population. However, there is yet no drug that has
reliable effects on senile dementia on the market. Therefore, society requires
the development of new drugs that can support patients so that they can smoothly
live their daily lives by themselves. In this study, we attempted to investigate
the 1998 domestic state of development of cognitive enhancers by summarizing many
publications and by gathering questionnaires from pharmaceutical, food, synthetic
fiber and chemical manufacturing companies. There were 40 currently investigated
cognitive enhancers in Japan as of the end of March, 1999 including 37 newly
synthesized compounds and 3 new dosage forms or applications of additional
effects. On the classification according to the mechanism of drug action, 12 of
the investigated drugs are cholinomimetic agents, 12 are ameliorators of neuronal
transmission, 1 is an intracellular mediative substance, 3 are neuropeptides, 2
are cerebral metabolic activators, 2 are cerebral circulation enhancers and 7 are
neuronal cell protectors, and 1 is another type. For dementia of the Alzheimer's
type, there are 1, 3, 10 and 2 drugs in prerecognition, phase late II, early II
and I of clinical trials, respectively. For cerebrovascular dementia and
cerebrovascular disease, there are 19 drugs being investigated. Seven of these
compounds such as E2020 (donepedil HCl), DM-9384 (nefiracetam), TA-0910
(taltirelin), NS-3 (montirelin), TTC-909 (clinprost), DR-3305 (ebselen) and AVS
(nicaraven) are at the prerecognition stage for marketing. It is important that
effective cognitive enhancers will be supplied for clinical stage use as soon as
possible.
PMID- 10672592
TI - The effects of multiple shunt revisions on neuropsychological functioning and
memory.
AB - The focus of this study was to determine the effect of multiple shunt revisions
on cognition and memory. The present study attempted to document a discrepancy in
the functioning of children with hydrocephalus having numerous shunt revisions
compared to those with only an initial shunt surgery. Researchers have found an
increasing number of children with hydrocephalus requiring shunt revisions. In
the current literature there are many conflicting views regarding the effects of
hydrocephalus on cognition and memory. Many researchers report that properly
treated hydrocephalus will not have a negative impact on cognitive functioning.
Furthermore, researchers found that factors such as the total number of shunt
revisions do not negatively impact global intellectual ability. Forty-six
subjects between the ages of six and 16 years participated in the study. The
subjects were recruited from the Department of Neurosurgery at an urban pediatric
hospital. Specific inclusion and exclusion criteria were met. Independent
variables for the study included shunt revisions, seizures, and Attention Deficit
Hyperactivity Disorder (ADHD). Subject groupings were based on whether the
subjects required multiple shunt revisions or single shunt placement and the
presence or absence of seizures and ADHD. Dependent variables included the
subject's performance on measures of cognition and memory. Measures of
functioning included the Wechsler Intelligence Scale for Children--Third Edition
and the Wide Range Assessment of Learning and Memory-Screener. The results of
this study did not support the presence of cognitive or memory impairments as a
result of multiple shunt revisions. Anecdotal findings noted that seizures were
the only independent variable to significantly account for the observed variance
in scores of cognition, specifically Full Scale IQ, Verbal Comprehension, and
Perceptual Organization.
PMID- 10672594
TI - [Molecular cell biology of presenilins].
AB - Alzheimer's disease (AD), the most common cause of dementia in the elderly, is a
progressive neurodegenerative disorder characterized pathologically by the
presence of senile plaques and neurofibrillary tangles in the brains of affected
individuals. Senile plaques are composed of amyloid-beta peptides (A beta), a
proteolytic derivative of the beta-amyloid precursor protein (beta APP). A subset
of AD is inherited as an autosomal dominant trait (familial AD, FAD). Mutations
in genes encoding beta APP, presenilin (PS) 1 and PS2 are known to cause FAD.
Genetic mutations in all three genes that cosegregate with FAD increase the
production of the most amyloidogenic species, A beta 42. Moreover, PS1-deficient
neurons exhibit severe defects in the production of A beta, suggesting that PS1
plays an important role in gamma-cleavage that liberates the C terminus of A
beta. The physiological role of PS is still unknown, but data from studies in C.
elegans, Drosophila and PS1 knock out mice suggests that PS1 plays a crucial role
in Notch signaling, and recently it was shown that PS1 is required for the
proteolytic release of the intracellular domain of Notch following activation of
Notch by its ligand. Further studies on PS-mediated intra- and jaxtamembranous
proteolysis will lead to the understanding of the pathological mechanism of AD as
well as of a novel mode of membrane protein processing.
PMID- 10672595
TI - [Molecular pharmacology and physiology of nociceptin].
AB - The family of the G protein-coupled opioid receptors was recently extended by a
novel member that did not bind any of the typical opioid receptor ligands.
Identification of the orphan receptor in this way led to the advent of "reverse
pharmacology" to identify the corresponding physiological ligands. Nociceptin, a
heptadecapeptide, which was discovered as an endogenous ligand, first, attracted
us by its reported nociceptive or anti-opioid actions. However, following studies
revealed that this peptide has both nociceptive and antinociceptive actions under
different conditions; e.g., administration routes or doses affect its actions. In
our recent studies using a unique peripheral peripheral nociception test,
nociceptin given locally at lower doses was found to produce nociception through
substance P release from nociceptor endings, while at higher doses, it produced
antinociceptive actions through an inhibition of phospholipase C activity
stimulated by nociceptive substances. Such hypothetical mechanisms can be applied
to the mechanisms of nociceptin-induced paradoxical actions in the central
nervous system. The physiological role of nociceptin has recently been reported
using nociceptin receptor knock-out mice. Following the report of a hearing
problem in such mice, the nociceptin receptor was found to be involved in the
development of morphine analgesic tolerance. In this review, more findings on the
physiological roles of nociceptin or its receptor, such as pain control and
memory-learning, are discussed on the basis of reports using nociceptin receptor
knock-out mice.
PMID- 10672596
TI - [Analysis of intracellular calcium dynamics in enterochromaffin cells of small
intestine].
AB - Although serotonin (5-HT) release from enterochromaffin (EC) cells is considered
to be regulated by multiple receptor-mediated mechanisms, little is known about
the signal transduction. Here, we introduce the methods to isolate the mouse
ileal crypts, which consist of various types of cells including EC cells, and to
analyze the intracellular calcium dynamics. Ileal tissue was inserted with a
plastic straw and the smooth muscle layers were peeled off. The mucosa were
digested with collagenase and then suspended by moderate pipetting. Ileal crypts
were separated by stepwise filtrations through 2 different nylon-meshes. The
isolated crypt contained 0-3 EC cells as identified by immunostaining using anti
5-HT antibody followed by confocal microscopy. Isolated crypts were attached to a
coverglass by an adhesive material (Cell-Tak) and loaded with fura-2/AM.
Intracellular calcium dynamics in EC cells were obtained by digital video-imaging
analysis of fura-2 fluorescence followed by the identification of EC cells with
immunostaining of 5-HT granules. By these methods, it was suggested that
norepinephrine elicited a transient elevation of intracellular calcium
concentration in EC cells via alpha 2-adrenoceptors. These methods could be also
useful to analyze the signal transduction system in intestinal endocrine cells
that contain various intestinal hormones such as gastrin, cholecystokinin or
secretin.
PMID- 10672597
TI - [Usefulness of conditioned place preference (CPP) paradigm and its practical
application].
AB - The conditioned place preference (CPP) paradigm is used to evaluate motivational
properties such as rewarding or aversive effects of drugs. It was first
introduced in the early 1980s to compensate for methodological and interpretive
difficulties associated with the self-administration technique, the conventional
method for assessing rewarding properties of drugs. The CPP paradigm has become
the most frequently used method and its use has been reported more frequently
than the self-administration paradigm. Although the CPP paradigm has mainly been
performed in the rat, we have successfully established the CPP paradigm for the
mouse. Thus, the CPP paradigm is now widely accepted as the behavioral approach
to pave the way for the neural mechanisms of rewarding effect and for screening
drugs for abuse liability. In this review, I focused on the significance, one's
way of thinking, methodology, application and controversial points of the CPP
paradigm.
PMID- 10672598
TI - [Effects of nitrendipine on the development of hypertension and renal failure in
Dahl salt-sensitive rats].
AB - The present study investigated the development of hypertension and the functional
and morphological changes in the kidney in Dahl salt-sensitive (Dahl S) rats fed
with a normal salt diet during aging. Furthermore, the effects of calcium channel
antagonists nitrendipine and nicardipine on these changes were examined. The rats
showed proteinuria from 6 weeks of age and gradually developed hypertension
accompanied by the decrease in the glomerular filtration rate during aging.
Glomerular screlosis and degeneration of the renal tubule were found by
histological examinations at 17 weeks of age. Nitrendipine (20 mg/kg chow), given
from 7 weeks of age for 10 weeks, inhibited the elevation in systolic blood
pressure from 3 weeks after the dosing, whereas nicardipine (20 mg/kg chow)
inhibited it only at 5 weeks after dosing. Both drugs decreased glomerular
sclerosis, but did not affect the glomerular filtration rate, urine volume,
urinary excretion of protein and N-acetyl-beta-D-glucosaminidase and serum
concentrations of creatinine and urea nitrogen. These results demonstrated that
Dahl S rats fed with a normal salt diet spontaneously developed the renal
disorder in the early stage of hypertension and reinforce the validity of
nitrendipine for the treatment of hypertensive patients with renal failure.
PMID- 10672599
TI - [Correction of deformities of extremities I].
PMID- 10672600
TI - [Guided transosseous osteosynthesis. Modelling the size and shape of anatomical
structures of the spine].
PMID- 10672601
TI - [Behavior of soft tissue structures in surgical leg lengthening].
AB - Experimental animal studies and clinical investigations show three processes
going on during extremity lengthening with the Ilizarov-method. At first
degenerative changes including cell necroses in the muscles, the nerves and the
tendons [corrected] occur as well as denervation of muscle fibers resulting in
neurogenous muscle atrophies. These alterations are followed by reperative and
regenerative processes as well as the reinnervation of the denervated muscle
fibers. Secondly histoneogenesis occur which leads to a high increase of tissue
specific cells and a growth of the muscles, tendons and vessels. Therefore
tensile-stress is an important factor of tissue growth. Thirdly adaptive
processes proceed during leg lengthening. For example the high biosynthetic
activity during tissue growth seems to indicate an increase of vasa vasorum.
PMID- 10672602
TI - [Sonographic imaging of leg geometry].
AB - Posttraumatic malalignments are a frequent sequlae of IM nailing of lower
extremity fractures. Conventional US has proven to be inferior to CT
determinations of tibial or femural length and torsion. A new 3-D US method is
presented that allows for accurate single step determination of lower extremity
length and torsion without ionizing radiation. A regular US machine with a 5 Mhz
linear probe is combined with an US localizer. Reference markers affixed to the
lower extremity eliminate errors associated with patient position or motion. The
3-D US method was compared against CT (Ulm's method) in the measurement of
torsion and length of the tibia and femur in 50 adults and 50 children. In both
methods, the maximum difference of the intraindividual torsional angles and
length measurements was 7 degrees and 7 mm. The maximum standard deviation for
reproducibility in length measurement was 1.6 mm and 1.5 degrees for angular
torsion. The new 3-D US technique was superior to CT in terms of reliability and
reproducibility. Clinical advantages of the 3-D US technique include rapidity,
independence from patient motion or positioning and the avoidance of ionizing
radiation. Indications for 3-D torsional and length determinations include follow
up evaluation of adult and pediatric tibial and femoral fractures, pediatric limb
and gait evaluations, and osteotomy planning.
PMID- 10672603
TI - [Correction of leg deformities. Definition, estimation and realignment of axis
deviation and misalignment].
AB - The operative realignment of mechanical axis deviations (MAD) is necessary to
prevent early joint degeneration and to reach normal load-bearing. Modern types
of external fixation systems allow an alignment of the mechanical axis to exact
degrees. Predominantly this are corrections of angular deformities. In some cases
the analysis of the MAD does not show any angular deformity, but a parallel
staggering of the mechanical axis lines of a bone. Such parallel staggering of
the mechanical axis lines is defined as a translation deformity of the bone. In
combined deformities with angulation and translation the centre of deformity can
be established proximal or distal out of the limit of the bone. In translation
deformities the realignment of the mechanical axis requires a parallel re
staggering made by a translation-osteotomy or by a counter-angulated double
osteotomy. In complex deformities with angulation and translation, the
translation requires a separate corrective planning. By using external fixator
systems to perform acute or progressive corrective osteotomies the position of
the Axis of Correction of Angulation (ACA) in relation to the n-CORA of the
deformity has to be considered. If ACA position is not conform with the n-CORA
position relevant geometric effects in relation of length and translation occur.
These geometric effects to corrective osteotomies can be calculated by using
simple trigonometric formulas or graphical methods. Possibilities to compensate
translation and length effects are shown by using unilateral external fixator
systems.
PMID- 10672604
TI - [Management of fibular hemimelia].
AB - Fibular hemimelia is a congenital longitudinal deficiency that represents a
spectrum of deformities. The management of this condition is controversial and
our treatment options are changing with developments in limb reconstruction
techniques. For the severely affected child with a predicted limb length
discrepancy greater than 25 cm at maturity and with a poor foot and ankle
amputation is generally agreed to be the best option. For less severely affected
limbs, particularly those with a predicted limb discrepancy of 10 cm or less and
with a foot with 3 or more rays which can be made plantigrade, limb
reconstruction is recommended. Controversy remains about the best way to manage
children with an intermediate deformity.
PMID- 10672605
TI - [Cogenital femoral defect. Indication, therapy and complication management].
AB - Congenital femoral deficiencies remain a surgical challenge. There is no common
classification: both radiological and clinical methods are recommended. Depending
on the severity of the deformity, reconstructive and lengthening techniques are
performed, while accompanying deformations are taken into consideration. In
addition, amputation or fusion techniques together with orthotic devices are
used. A total of 35 patients (37 extremities) with congenital femoral
deficiencies have been treated at the Orthopaedic Hospital Vienna-Speising, from
1982 to 1998. 24 extremities were treated with reconstructive and/or lengthening
techniques. Results and complications are reported.
PMID- 10672607
TI - [Leg lengthening and correction of deformity using the femoral Albizzia nail].
AB - The albizzia femoral nail allows for lengthenings up to 10 cm. It can be used in
achondroplastic patients. Multiplane corrections can be addressed with a special
nail (3D-Albizzia) if multiple osteotomies are performed (e.g. for proximal and
distal femoral varus). A derotation and a flexion/extension osteotomy can also be
associated. IM nailing is suitable for patient with previous external fixators.
Surgical planning should be careful. The operation is currently performed
percutaneously, with a 1 to 2 cm skin incision for nail insertion, and a 6 mm
incision for distal femoral dome osteotomies. CPM machine is applied in recovery
room and rehabilitation resumes on day 1, allowing more than 120 degrees of knee
flexion by day 1. Ratcheting for gradual lengthening is begun on day 5 at a rate
of 1 mm/day. Muscle stretching and strengthening are maintained for one year. In
bilateral cases, a preoperative strengthening program is set. A 120 degrees knee
range of motion can be maintained all during lengthening. Intramedullary
lengthening allows for maintaining muscle and soft tissue suppleness which
protects from hyperpressure over joints and from long-term muscle waisting. The
Albizzia is currently a good tool once the surgeon get used to its physiotherapy
aspect. Previously reported general anaeshtesia for getting the ratcheting is
barely needed, when the technique has been done percutaneously and when the full
range of knee motion is recovered on day 1 and maintained thereafter.
PMID- 10672606
TI - [Fully implantable intramedullary distraction nail in shortening deformity and
bone defects. Spectrum of indications].
AB - Since the first clinical experiences with the fully implantable programmable
distraction nail nearly ten years ago, the system has been improved in Munich and
meanwhile used in 26 patients. During the first 10 cases there has been highest
interest in the reliability of the system, while in the following the expansion
of indications was more important. At the thigh a good indication beside
shortening is the combination of shortening and axis deviation, even if the
center of deviation is located near to the knee joint in the supracondylar area.
According to preoperative planing the deformity correction can be done acutely
while the lengthening procedure follows postoperatively automatically at night
time. If the stabilization with an intramedullary nail is possible, large bone
defects can be treated by bone transport using this system also. The fully
implantable intramedullary nail has proved its variable functions in cases of
large bone defects combined with shortening of the femur. The system is able to
perform the bone transport at first and the lengthening procedure automatically
without any further operation thereafter.
PMID- 10672608
TI - [External transpedicular fixation in the treatment of injuries of the spinal
column and spinal cord].
AB - Injuries to the spine and the spinal cord are an important problem. In the
present paper the application of external transpedicular fixation of the spinal
column for surgical treatment of patients in the acute phase of spinal cord
injuries is described. The results of treatment obtained in 54 patients in the
acute phase are presented. Decompression of the spinal cord can be accomplished
by way of a dorsal approach. In this way it is possible to remove the compressing
factor in stages. Positive results were achieved in the late phase in 84.22% of
patients with acute spinal and spinal cord injuries.
PMID- 10672609
TI - Introduction: magnetic resonance imaging.
PMID- 10672610
TI - From signal to image: magnetic resonance imaging physics for cardiac magnetic
resonance.
AB - Magnetic resonance imaging (MRI) is a powerful tool which enables the
visualization of anatomy and the assessment of many physiological aspects of
organ function. MRI and magnetic resonance angiography and magnetic resonance
spectroscopy will play critical roles in cardiac applications during the next
millennium. Thus, it is important to have a basic understanding of the most
important physical processes in MR--the generation of nuclear magnetic resonance
signals and their transformation into images. A conceptual description of these
processes is the primary focus of this article. Also discussed are some
additional signal manipulations specific to the needs of cardiac MRI, a field
readily identified as the most significant in modern MRI technology development.
PMID- 10672611
TI - Assessment of cardiovascular anatomy in patients with congenital heart disease by
magnetic resonance imaging.
AB - The following discussion addresses the assessment of cardiovascular anatomy in
patients with congenital heart disease by magnetic resonance (MR). The focus of
this review is on the techniques of performing the MR examination. In particular,
individual pulse sequences are described and illustrated with their strengths and
weaknesses. Imaging strategies using the described pulse sequences are proposed.
The pulse sequences described are widely available on most MR scanners.
Therefore, the proposed imaging strategies are clinically proven to be simple and
effective ways to perform cardiac MR examination for the assessment of
cardiovascular anatomy in patients with congenital heart disease. Functional
imaging, such as flow analysis and ventricular function assessment, are discussed
elsewhere in this issue.
PMID- 10672612
TI - Three- and four-dimensional visualization of magnetic resonance imaging data sets
in pediatric cardiology.
AB - The purpose of medical imaging technology in pediatric cardiology is to provide
clear representations of the underlying anatomy and physiology of the
cardiovascular system--representations that are easily understood and that
facilitate clinical decision making. However, standard projective and tomographic
imaging methods often yield results that are intelligible only to imaging
specialists. Three- and four-dimensional reconstructions from projective and
tomographic data sets are an alternative form of image display. Often, these
reconstructions are more readily comprehensible as representations of the reality
apparent in the operating room or the pathology laboratory than are the original
data sets. Furthermore, viewing of these reconstructions is much more time
efficient than viewing hundreds of separate tomographic images. Magnetic
resonance imaging inherently provides three-, four-, and even higher dimensional
data, and magnetic resonance data sets are commonly used to generate volumetric
reconstructions. This review will focus on the practical application of magnetic
resonance imaging to yield three- and four-dimensional reconstructions of
pediatric cardiovascular disorders.
PMID- 10672613
TI - The range of normal values of cardiovascular structures in infants, children, and
adolescents measured by magnetic resonance imaging.
AB - Magnetic resonance imaging (MRI) is a powerful diagnostic technique and research
tool for assessment of congenital heart disease due to its ability to accurately
assess anatomy, function, and flow in any orientation in the thorax. However,
little data exist on normative reference values for cardiac structures, except in
small study populations, and even fewer data exist for pediatric populations. In
this review, MRI acquisition and analysis methods for assessment of aortic size,
pulmonary artery size, and right and left ventricular function, volume, and mass
are presented along with reference data obtained in pediatric populations by MRI.
Where MRI data are not available, reference data obtained by echocardiography or
angiography are included.
PMID- 10672614
TI - Blood flow measurement by magnetic resonance imaging in congenital heart disease.
AB - Investigation of blood flow in the heart and vessels may provide insight into the
function of the cardiovascular system and aid patient management decisions. Phase
velocity cine magnetic resonance imaging (PVC MRI) is a powerful and accurate
noninvasive technique to quantitate and analyze blood flow. This article
describes the principles, performance, and potential limitations of PVC MRI
measurements. Clinical applications of PVC MRI are then reviewed with an emphasis
on the assessment of congenital heart disease.
PMID- 10672615
TI - Assessment of cardiac function by magnetic resonance imaging.
AB - Magnetic resonance imaging (MRI) is a unique and insightful tool for the
assessment of physiology and function in congenital heart disease, in both the
preoperative and postoperative state. MRI can accurately measure the volume and
mass of unusual ventricular shapes, perform myocardial tissue and blood tagging,
and can measure velocity and flow using phase-encoded velocity mapping. This has
added new dimensions to research in pediatric cardiology. Newer techniques such
as oxygen-sensitive MRI and echo-planar MRI promise further advances in the
field. This article describes contemporary MRI studies of the physiology of
complex congenital heart disease.
PMID- 10672616
TI - Clinical applications of cardiac magnetic resonance imaging after repair of
tetralogy of Fallot.
AB - In the past 15 years, cardiovascular magnetic resonance (MR) has evolved into an
imaging technique that provides adequate, and in part unique, information on
residual problems in the follow-up of patients operated for tetralogy of Fallot.
Spin-echo or gradient-echo cine magnetic resonance imaging allow detailed
assessment of intracardiac and large vessel anatomy, which is particularly
helpful in Fallot patients with residual abnormalities of right ventricular
outflow and/or pulmonary artery. Multisection gradient-echo cine MRI can be used
to obtain accurate measurements of biventricular size, ejection fraction, and
wall mass. This allows serial follow-up of biventricular function. MR velocity
mapping is the only imaging technique available that provides practical
quantification of pulmonary regurgitation volume. MR velocity mapping can also be
used to quantify right ventricular diastolic function in the presence of
pulmonary regurgitation.
PMID- 10672617
TI - Real-time magnetic resonance imaging: diagnostic and interventional applications.
AB - The advent of ultra-fast imaging techniques has extended the utility of magnetic
resonance imaging (MRI) from a static and purely diagnostic status to an imaging
modality ideally suited for a number of therapeutic applications. These advances-
along with the recent development and refinement of miniature intravascular
imaging catheters and MRI-compatible guidewires, balloon catheters, and
radiofrequency ablation catheters--have created an exciting forum of novel
approaches for detecting and treating both acquired and congenital cardiovascular
disease. This review covers the current state of the art in fast cardiovascular
MRI, catheter-tracking techniques for MR fluoroscopy, and currently available
interventional MRI systems. Early diagnostic and therapeutic applications, such
as high-resolution intravascular and intracardiac imaging, balloon angioplasty,
stent placement, and radiofrequency ablation techniques, are discussed and
extended to several potential approaches specific to pediatric cardiac
therapeutic catheterization. Lastly, safety aspects of MR-guided interventional
procedures are presented.
PMID- 10672618
TI - Microscopic and histochemical manifestations of hyaline cartilage dynamics.
AB - Structure and function of hyaline cartilages has been the focus of many
correlative studies for over a hundred years. Much of what is known regarding
dynamics and function of cartilage constituents has been derived or inferred from
biochemical and electron microscopic investigations. Here we show that in
conjunction with ultrastructural, and high-magnification transmission light and
polarization microscopy, the well-developed histochemical methods are
indispensable for the analysis of cartilage dynamics. Microscopically
demonstrable aspects of cartilage dynamics include, but are not limited to,
formation of the intracellular liquid crystals, phase transitions of the
extracellular matrix and tubular connections between chondrocytes. The role of
the interchondrocytic liquid crystals is considered in terms of the tensegrity
hypothesis and non-apoptotic cell death. Phase transitions of the extracellular
matrix are discussed in terms of self-alignment of chondrons, matrix guidance
pathways and cartilage growth in the absence of mitosis. The possible role of
nonenzymatic glycation reactions in cartilage dynamics is also reviewed.
PMID- 10672619
TI - Self-mutilation, masochism, and rigid character.
PMID- 10672620
TI - Flesh made word: cutting back to the mother.
PMID- 10672621
TI - Erotized transference and self-mutilation.
PMID- 10672622
TI - Some reflections on self-mutilation.
PMID- 10672623
TI - Further thoughts on "self-cutting": the intersubjective context of self
experience and the vulnerability to self-loss.
PMID- 10672624
TI - The lie: anorexia and the paternal metaphor.
PMID- 10672625
TI - "A right-sided facial neuralgia": or fragmenting the history of the "Dora"
manuscript.
PMID- 10672626
TI - Abuse liability assessment of sibutramine, a novel weight control agent.
AB - RATIONALE: Sibutramine (Meridia) is a serotonin and norepinephrine reuptake
inhibitor marketed for weight control. Previous studies demonstrated low abuse
potential for 20 and 30 mg sibutramine (doses near the therapeutic range);
however, no data existed on supratherapeutic doses. This study, therefore,
examined 25 and 75 mg sibutramine in humans compared to d-amphetamine (20 mg) as
a positive control and placebo as a negative control. OBJECTIVES: The study
examined the acute subjective, reinforcing, and physiological effects of
sibutramine to assess its abuse liability. METHODS: Twelve polydrug abusers with
no history of drug dependence participated in this double-blind,
inpatient/outpatient study. Volunteers participated in four drug sessions, in
which they completed subjective effects scales including the Profile of Mood
States (POMS), Visual Analog Scales (VAS), and the Addiction Research Center
Inventory (ARCI). The Multiple Choice Procedure (MCP) was used to evaluate
reinforcing efficacy. RESULTS: Sibutramine 25 mg produced subjective effects that
were indistinguishable from placebo. Sibutramine 75 mg produced significant
unpleasant effects, such as Anxiety, Confusion, and decreased Vigor. On the MCP,
volunteers chose to give up an average of $4.04 from their study pay rather than
receive the higher dose of sibutramine again. In contrast, d-amphetamine 20 mg
produced positive mood changes and was well liked. CONCLUSIONS: These data
indicate sibutramine lacks amphetamine-type abuse liability when administered
acutely.
PMID- 10672627
TI - Activation of the mesocorticolimbic dopaminergic system by stimulation of
muscarinic cholinergic receptors in the ventral tegmental area.
AB - OBJECTIVE: To investigate the function of muscarinic receptors in the ventral
tegmental area in vivo, the release of endogenous monoamines was simultaneously
measured in the somatodendritic (ventral tegmental area) and terminal (frontal
cortex and nucleus accumbens) regions of the mesocorticolimbic dopaminergic
system in rats, using dual probe microdialysis. METHODS: Rats were implanted with
dual microdialysis probes ipsilaterally into the ventral tegmental area (VTA) and
nucleus accumbens (NAC) or frontal cortex (FC). RESULTS: Intrategmental infusion
of the muscarinic agonist oxotremorine M (OXO M, 0.1 and 1 mM) increased
extracellular levels of dopamine and serotonin, but not noradrenaline, in the VTA
to a maximum of 200% over baseline in both urethane-anaesthetized and
unanaesthetized rats. In freely moving animals, this effect was accompanied by
strong motor agitation. Both VTA dopamine and serotonin levels dropped to 60% or
less of baseline when the perfusion medium was replaced by a calcium-free medium
containing OXO M. In the NAC and FC, a similar increase in extracellular
dopamine, but not serotonin and noradrenaline, was observed during OXO M infusion
in the VTA. The removal of calcium during OXO M infusion in the VTA did not cause
a decrease in NAC dopamine levels. Activation of serotonin and dopamine release
by OXO M in the VTA and FC was dramatically reduced or prevented by the co
infusion of the muscarinic antagonist N-methylscopolamine (0.1 mM). CONCLUSION:
These data demonstrate that VTA dopamine cells possess functional muscarinic
receptors whose activation stimulates the release of dopamine in the VTA, NAC and
FC. These results also suggest that muscarinic receptors may modulate the
synaptic release of serotonin in the VTA.
PMID- 10672628
TI - Sub-chronic inhibition of nitric-oxide synthesis modifies haloperidol-induced
catalepsy and the number of NADPH-diaphorase neurons in mice.
AB - RATIONALE: NG-nitro-L-arginine (L-NOARG), an inhibitor of nitric-oxide synthase
(NOS), induces catalepsy in mice. This effect undergoes rapid tolerance, showing
a significant decrease after 2 days of sub-chronic L-NOARG treatment. Nitric
oxide (NO) has been shown to influence dopaminergic neurotransmission in the
striatum. Neuroleptic drugs such as haloperidol, which block dopamine receptors,
also cause catalepsy in rodents. OBJECTIVES: To investigate the effects of
subchronic L-NOARG treatment in haloperidol-induced catalepsy and the number of
NOS neurons in areas related to motor control. METHODS: Male albino Swiss mice
were treated sub-chronically (twice a day for 4 days) with L-NOARG (40 mg/kg
i.p.) or haloperidol (1 mg/kg i.p.). Catalepsy was evaluated at the beginning and
the end of the treatments. Reduced nicotinamide adenine dinucleotide phosphate
diaphorase (NADPH-d) histochemistry was also employed to visualize NOS as an
index of enzyme expression in mice brain regions related to motor control.
RESULTS: L-NOARG sub-chronic administration produced tolerance of L-NOARG and of
haloperidol-induced catalepsy. It also induced an increase in the number of NADPH
d-positive cells in the dorsal part of the caudate and accumbens nuclei compared
with haloperidol and in the pedunculopontine tegmental nucleus compared with
saline. In contrast, there was a decrease in NADPH-d neuron number in the
substantia nigra, pars compacta in both haloperidol-treated and L-NOARG-treated
animals. CONCLUSIONS: The results give further support to the hypothesis that NO
plays a role in motor behavior control and suggest that it may take part in the
synaptic changes produced by antipsychotic treatment.
PMID- 10672629
TI - A lack of tolerance to the anxiolytic effects of diazepam on the plus-maze:
comparison of male and female rats.
AB - RATIONALE: The demonstration of tolerance to the anxiolytic effects of
benzodiazepines remains inconsistent. OBJECTIVES: The present study tested the
hypothesis that intact and gonadectomized male and female rats might exhibit
differential tolerance to the anxiolytic effects of diazepam (DZ). METHODS:
Following acute (3 days) or chronic (3 weeks) DZ exposure, all animals were
tested on the elevated plus-maze and immediately sacrificed for analysis of
corticosterone, adrenocorticotropin hormone, estrogen and progesterone levels in
serum. In experiment 2, following acute or chronic DZ exposure, animals were
treated with a DZ challenge dose on the test day. RESULTS: In experiment 1, both
acute and chronic DZ treatment similarly enhanced percentage open arm time and
entries, regardless of the hormonal status of the animal. The results of
experiment 2 showed that both acute and chronic DZ-treated animals exhibited a
significantly higher percentage open arm time than control animals after the DZ
challenge dose, and males and females did not differ in their responses to DZ
exposure. CONCLUSIONS: The findings from these experiments suggest that tolerance
to the anxiolytic effects of DZ did not develop in males or females, and that the
hormonal status of the animal does not significantly alter the anxiolytic effects
of DZ following either acute or chronic exposure. Following plus-maze exposure,
females had significantly higher corticosterone levels than males and acute DZ
treatment diminished this stress response.
PMID- 10672630
TI - Caffeine withdrawal increases cerebral blood flow velocity and alters
quantitative electroencephalography (EEG) activity.
AB - RATIONALE: Cessation of daily caffeine consumption produces a withdrawal syndrome
comprised of subjective symptoms and functional impairment. Few controlled
studies have examined the physiological effects of caffeine withdrawal.
OBJECTIVE: The present study examined the effect of caffeine withdrawal on
cerebral blood flow velocity and quantitative EEG. METHODS: Ten volunteers
reporting moderate caffeine intake (mean 333 mg/day) participated in this double
blind study. Subjects completed several tests when maintaining their normal diet
(baseline period) and during two 1-day periods during which they consumed
caffeine-free diets and received capsules containing placebo (placebo test
session) or caffeine (caffeine test session) in amounts equal to their baseline
daily caffeine consumption. Blood flow velocity was determined for four arteries:
right and left middle (MCA), and right and left anterior (ACA) cerebral arteries
using pulsed transcranial Doppler sonography. EEG was recorded for 3 min from
eight scalp sites while subjects sat, with eyes closed, in a sound-attenuated
electronically shielded chamber. Subjective effects were assessed with
questionnaires. RESULTS: Results showed an effect of the placebo (21-h
withdrawal) condition compared to the caffeine condition. Placebo significantly
increased the mean velocity, systolic velocity and diastolic velocity (cm/s) in
all four cerebral arteries. In the MCA, the pulsatility index was significantly
decreased following placebo. Placebo significantly increased EEG theta power.
Placebo also produces subjective effect changes, including increases in heavy
feelings in arms and legs and decreases in ability to concentrate. The caffeine
and baseline conditions produced similar results on both the physiological and
subjective measures. CONCLUSION: Cessation of daily caffeine consumption produced
changes in cerebral blood flow velocity and quantitative EEG. These changes may
be related to classic caffeine withdrawal symptoms of headache, drowsiness and
decreased alertness.
PMID- 10672631
TI - Effect of adjunctive paroxetine on serum levels and side-effects of tricyclic
antidepressants in depressive inpatients.
AB - RATIONALE: Previous studies showed that adjunctive paroxetine increases tricyclic
antidepressant (TCA) serum levels by inhibiting cytochrome P4502D6. This effect
has, however, been examined only in experimental studies using low doses of TCAs
in healthy volunteers. OBJECTIVE: The present study investigated TCA serum level
changes and side-effects after the addition of paroxetine in depressed patients
treated with doses customarily used for inpatients. METHODS: 14 patients who had
a moderate or severe depressive episode according to ICD-10 and who had not
sufficiently responded (< or = 25% reduction of the Hamilton depression scale) to
3-week monotherapy with amitriptyline (n = 9) or imipramine (n = 5) with daily
doses between 125 and 200 mg/day, received 20 mg/day paroxetine additionally
under steady state conditions. RESULTS: After 2 weeks the serum levels of the
metabolites nortriptyline (from 88 +/- 49 ng/ml to 176 +/- 57 ng/ml) and
desipramine (from 152 +/- 78 ng/ml to 338 +/- 104 ng/ml) had risen to a
significantly greater extent than those of the parent compounds amitriptyline
(123 +/- 50 ng/ml to 195 +/- 128 ng/ml) and imipramine (from 75 +/- 36 ng/ml to
98 +/- 51 ng/ml). It is noteworthy that, with the exception of one case of
incipient delirium, the combination therapy was well tolerated despite high TCA
serum level rises. CONCLUSION: The higher increase of the metabolites as compared
with the parent compounds can be explained by a paroxetine-induced inhibition of
the liver enzyme cytochrome P4502D6, which catalyses the second step of the TCA
metabolism, i.e. the hydroxylation of the metabolites. Blood levels should be
meticulously monitored, if TCAs are combined with paroxetine.
PMID- 10672632
TI - Effect of zopiclone and temazepam on sleep EEG parameters, psychomotor and memory
functions in healthy elderly volunteers.
AB - RATIONALE: The increased prevalence of sleep disturbance in old age is
accompanied by a higher prescription rate of hypnotics, predominantly
benzodiazepines in the elderly. In young volunteers zopiclone exerts a beneficial
effect on sleep continuity without suppression of SWS and REM sleep; psychomotor
performance and vigilance seemed to be less impaired than under classical
benzoediazepines. OBJECTIVE: The present study investigates the effects of
zopiclone on sleep EEG and cognitive performance in comparison to temazepam and
placebo in the elderly population. METHODS: Single oral doses of zopiclone (7.5
mg), temazepam (20 mg) and placebo were administered in a randomized double
blind, completely counterbalanced cross-over design to 12 healthy elderly men and
women (65.9 +/- 3.6 years, range 60-70 years). On each of the 3 study nights a
sleep EEG was registered from 10 p.m. to 6.30 a.m. and cognitive performance
tests were applied at 8 p.m., 2 a.m. (when subjects were awake for 30 min), 7
a.m. and 9 a.m. RESULTS: After zopiclone treatment, sleep continuity had
significantly improved and sleep stage 4 was increased compared to temazepam and
placebo. In addition, both active substances significantly reduced REM density.
Neither active compound substantially altered psychomotor and memory performance.
CONCLUSIONS: Zopiclone and temazepam can be considered as effective hypnotics in
elderly subjects when administered in that dosage. The superiority of zopiclone
on sleep architecture may be related to a more specific action of zopiclone at
the GABA-A benzodiazepine receptor complex. The suppression of REM density by
both compounds and their subtle effects on cognition may reflect a GABAergic
mediated reduction of cholinergic neuro-transmission.
PMID- 10672633
TI - Effects of a low dose of alcohol on recollective experience of illusory memory.
AB - RATIONALE: Memory illusions are currently a focus of memory research. Studies
using the Deese/Roediger and McDermott paradigm have shown a differential pattern
of illusory memories is associated with amnesia and ageing. The effects of
pharmacological agents in this paradigm are not yet known. OBJECTIVE: Using this
paradigm, the present study investigated the effects of a low dose of alcohol
upon recollective experience of illusory memories. METHODS: A double-blind cross
over design was used to compare the effects of alcohol (0.26-0.28 g.kg-1) with a
matched placebo drink. RESULTS: High levels of false recognition were obtained
across both treatments, replicating previous results. Although the small dose of
alcohol employed did not produce gross changes in measures of false memory, it
did modify the pattern of recollective experience in terms of remember and know
responses. Specifically, it increased the level of remember responses for falsely
recognised items (critical lures). CONCLUSION: These results are discussed in
terms of ethanol's effects on false recognition of information which was not
presented during the study episode. The effects of low dose alcohol on illusory
memory are similar to the pattern found in ageing rather than that found in
organic amnesia.
PMID- 10672634
TI - Acamprosate, but not naltrexone, inhibits conditioned abstinence behaviour
associated with repeated ethanol administration and exposure to a plus-maze.
AB - RATIONALE: Drugs that reduce relapse in alcoholics are thought to inhibit either
positive reinforcement for drinking (e.g. naltrexone) or negative reinforcement
(e.g. acamprosate), and may reduce the impact of conditioned stimuli associated
with previous alcohol use. We have developed a model for such conditioning by
repeatedly pairing ethanol administration with plus-maze exposure. Substitution
of saline for ethanol greatly increased stretched-attend postures and time in the
central square, conditioned to the environment. OBJECTIVE: To test the hypothesis
that if this behaviour indicates a negative affective state caused by the
expectation of ethanol, it should be inhibited by drugs that reduce negative, but
not positive, reinforcement. METHODS: The effects of naltrexone and acamprosate
on alcohol-conditioned abstinence behaviour were compared. RESULTS: Acute
administration of either drug alone produced no significant effects on plus-maze
behaviour in naive mice. Naltrexone had no significant effect on the alcohol
conditioned abstinence behaviour, but acamprosate reduced the incidence of
stretched-attend postures. CONCLUSIONS: The experiments replicated previous
findings for alcohol/environment conditioned behaviour, and demonstrated, as
predicted, that this was decreased by acamprosate but not by naltrexone. Effects
of acamprosate on conditioned negative reinforcement may be the cause of this
effect, but more work is required to establish the usefulness of this model in
evaluation of anti-relapse drugs.
PMID- 10672635
TI - 5-HT3- and 5-HT2C-antagonist properties of cyamemazine: significance for its
clinical anxiolytic activity.
AB - RATIONALE: Cyamemazine is a neuroleptic compound which possesses anxiolytic
properties in humans. On the other hand, 5-HT3- and 5-HT2C-receptors have been
implicated in anxiety disorders and a previous binding study has shown that
cyamemazine possesses high affinity for both serotonin receptor types. OBJECTIVE:
The present study was undertaken to establish whether cyamemazine antagonizes 5
HT3- and/or 5-HT2C-mediated responses, and whether it compares with reference
compounds. METHODS: Cyamemazine was tested for its ability to antagonize: (i) 5
HT3-dependent contraction of the isolated guinea-pig ileum and bradycardic
responses in the rat and (ii) 5-HT2C-dependent phospholipase C (PLC) stimulation
in rat brain membranes. RESULTS: In isolated guinea-pig ileum, cyamemazine
potently and competitively antagonized 5-HT-dependent contractions (pA2 = 7.52 +/
0.08; n = 5). In this test, cyamemazine was 5-7 times more potent (pIC50 = 6.75
+/- 0.13) than tropisetron (pIC50 = 6.02 +/- 0.04). In rats, cyamemazine i.v.
antagonized 5-HT-dependent bradycardic responses with ID50% = 3.2 +/- 1.5 mg/kg
(n = 4). Finally, in rat brain membranes cyamemazine antagonized 5-HT2C-dependent
PLC stimulation with Ki = 424 nM (mianserin exhibits a Ki = 113 nM). CONCLUSIONS:
Cyamemazine behaves as an antagonist at both 5-HT3- and 5-HT2C-receptors, which
compares well with reference compounds. These 5-HT3- and 5-HT2C-antagonistic
actions of cyamemazine can be involved, at least in part, in its beneficial
therapeutic actions in anxiety disorders.
PMID- 10672636
TI - Reduction of drug self-administration by an alternative non-drug reinforcer in
rhesus monkeys: magnitude and temporal effects.
AB - RATIONALE: Recent studies have shown that non-drug alternative reinforcers reduce
drug self-administration. A goal of the present study was to explore factors such
as magnitude of the alternative reinforcer and inter-session access to the
alternative to identify conditions that lead to optimal reductions in drug
intake. OBJECTIVES: To evaluate the effects of increasing the volume/delivery
(v/d) of saccharin on oral phencyclidine (PCP) self-administration in rhesus
monkeys given continuous access to PCP and saccharin during daily sessions using
a behavioral economic analysis. The effects of availability of a saccharin
solution during the inter-session period on session PCP consumption in drug
experienced monkeys was also investigated. METHODS: Subjects had access to PCP
(0.25 mg/ml) and either water or saccharin (0.03%) from two drinking spouts under
concurrent and independent fixed-ratio (FR) schedules during daily 3-h sessions.
The FR requirements for both available liquids were simultaneously increased (FR4
64). The v/d of saccharin or water was increased (from 0.3 ml to 1.2 ml), while
the v/d of PCP remained constant (0.6 ml). In a second experiment, subjects had
access to water or saccharin and water during the inter-session period (17.5 h)
under an FR1 schedule. PCP and water were available during daily 3-h sessions
under concurrent FR schedules. The FR for both liquids was increased (FR16-128).
RESULTS: PCP intake was reduced at all FRs and magnitude conditions when
saccharin (versus water) was concurrently available. Varying the v/d of saccharin
only had a modest effect on the extent to which PCP intake was decreased at the
higher FR values. Inter-session saccharin availability (versus water) reduced
session PCP intake and the magnitude of this effect was also greater at the
higher FR values. CONCLUSIONS: The magnitude of the saccharin delivery had an
effect on PCP consumption at higher FRs, suggesting that economic factors such as
high drug cost (FR) and low cost (responses/ml) of the alternative reinforcer
(saccharin) interact to produce a maximum suppression of drug intake. Between
session availability of saccharin also effectively reduced drug intake, and it
had a greater effect on the maintenance levels of drug self-administration when
the unit price of drug was high.
PMID- 10672637
TI - 3'- and 4'-chloro-substituted analogs of benztropine: intravenous self
administration and in vitro radioligand binding studies in rhesus monkeys.
AB - RATIONALE: The reinforcing effects of many psychomotor stimulants have been
related to increased dopaminergic neurotransmission. Drugs that block dopamine
(DA) uptake have generally been found to function as positive reinforcers.
Benztropine (BZT) and several of its halogenated analogs have previously been
characterized as potent DA-uptake inhibitors with behavioral profiles that
indicate diminished psychomotor stimulant effects relative to cocaine.
OBJECTIVES: The present experiments were designed to examine, in rhesus monkeys,
the reinforcing effects of the DA-uptake inhibitor BZT and two chloro-analogs 3'
Cl-BZT and 4'-Cl-BZT, and to compare self-administration and binding profiles.
METHODS: Four rhesus monkeys self-administered cocaine i.v. under a fixed-ratio
10 (FR10) schedule until stable responding was established. Saline, and various
doses of cocaine, BZT, and the BZT analogs were then made available for self
administration. Binding of these compounds to monoaminergic and cholinergic sites
in monkey brain were determined using standard radioligand binding techniques.
RESULTS: Self-administration was maintained by both 3'-Cl-BZT and 4'-Cl-BZT, but
not by BZT. Results suggested that 3'-Cl-BZT and 4'-Cl-BZT were weak positive
reinforcers. BZT and analogs bound DA transporters (DAT) with affinities higher
than that of cocaine and had affinity for muscarinic binding sites. CONCLUSIONS:
Surprisingly, high affinity at DATs was associated with weak or no reinforcing
effects. The mechanism(s) that may underlie this dissociation between DAT actions
and reinforcing effects remains to be established. These data support the
proposal that a lead for the discovery of a pharmacotherapeutic agent for cocaine
abuse may come from this group of compounds.
PMID- 10672638
TI - A behavioural model to reveal place preference to delta 9-tetrahydrocannabinol in
mice.
AB - RATIONALE: The rewarding properties of delta 9-tetrahydrocannabinol (THC) are
difficult to demonstrate in rodents using standard procedures. OBJECTIVE: To
evaluate the motivational responses of THC in the place conditioning paradigm in
mice after minimizing the dysphoric effects of the first drug exposure and/or the
consequences of its pharmacokinetic properties. METHODS: Mice were conditioned to
THC (1 or 5 mg/kg) using an unbiased procedure with an elevated number of
pairings and long conditioning time. RESULTS: A place aversion was observed with
5 mg/kg THC using a standard protocol. Similar results were obtained when the CB
1 receptor antagonist SR 141716A (1 mg/kg) was administered immediately after
each THC conditioning period. However, mice receiving a priming THC injection and
conditioned 24 h later showed a place preference with 1 mg/kg THC and no effect
with 5 mg/kg THC. CONCLUSION: THC produces a clear place preference in mice by
using a long period of conditioning and avoiding the possible dysphoric
consequences of the first drug exposure.
PMID- 10672640
TI - The 1999 Crafoord Prize Lectures. The idea of information in biology.
PMID- 10672639
TI - Experimental evidence that the aggressive effect of tryptophan depletion is
mediated via the 5-HT1A receptor.
PMID- 10672641
TI - The 1999 Crafoord Prize lectures. An evolutionist's perspective.
PMID- 10672642
TI - The 1999 Crafoord Prize lectures. The Tithonus error in modern gerontology.
AB - Tithonus asked Aurora for eternal life, when he meant eternal youth. Modern
gerontological research makes the same mistake in its preoccupation with death,
as if it were a programmed event in an organism's life history. Gerontology ought
instead to investigate senescence, the decreasing effectiveness of mechanisms by
which adult organisms avoid death or loss of fitness. Such studies should measure
rates of decline in a diversity of adaptations and compare them within and
between individuals and relate these rates and their correlations to genetic and
environmental factors. The death of a studied organism must necessarily end its
usefulness in providing valuable data. It is of little scientific significance.
PMID- 10672643
TI - The 1999 Crafoord Prize lectures. Neo-Lamarckian experimentalism in America:
origins and consequences.
AB - The 1890s and the first decades of the twentieth century saw a vigorous debate
about the mechanisms of evolutionary change. On one side, August Weismann
defended the selectionist hypothesis; on the other, Herbert Spencer defended neo
Lamarckian theory. Supporters of Spencer, notably the American paleontologist and
evolutionary theorist Henry Fairfield Osborn, recognized that the questions
raised by Weismann and Spencer could only be settled experimentally. They called
for the application of experimental methods, and the establishment of a new
institution for the purpose of confirming the inheritance of acquired characters.
To a great extent, the experimental program championed by Osborn and others was
implemented and, although it failed to reveal soft inheritance and was soon
eclipsed by Mendelian and chromosomal genetics, it did make significant and
lasting contributions to evolutionary biology. Thus the importance of
methodological and institutional innovation and theoretical pluralism to the
progress of science is illustrated and underscored.
PMID- 10672644
TI - [Inseparable by definition and history, maxillofacial surgery and stomatology
must build a program for the future together].
PMID- 10672645
TI - [What does the future hold for young maxillofacial surgeons?].
PMID- 10672646
TI - [Two or three things about the PMSI in stomatology and maxillofacial surgery].
AB - The Information Systems Medicalization Program (PMSI in French) was created in
1985 for Public Health Service Hospitalisation Structures. It appeared to be
directly derived from the North-American Diagnosis Related Groups (DRGs) system.
Since them, the PMSI has been progressively developed in private structures as
well. The authors have had the opportunity to use the latest version of the
computer program which was elaborated in order to share the patients into more
than 500 different groups of pathology. These groups were called "Homogeneous
Patients Groups" (GHM in French). To each group corresponds a "Synthetic Activity
Index" number (ISA in French). It is supposed to be representative of the average
cost of the management of each kind of patients, based on the diagnosis and the
surgery possibly done. Several astonishing findings have been made. Some of them
can be summarized as mentioned below: In maxillofacial Surgery, each group (GHM)
seems in fact to be extremely inhomogeneous: for example, total parotidectomy
with preservation of the facial nerve belongs to the same group as accessory
salivary gland exeresis. Total skin graft is in the same group as free composite
osseous flap with vascular anastomosis. Coding a surgical procedure leads often
to reduce the ISA number in comparison with the same patient without surgery:
"impacted third molar" gives 754 points without surgery but only 658 if surgery
is performed. Carcinologic surgery is wholly grouped in the same category, even
for rather short procedures as isolated partial glossectomy. This group
corresponds to a great number of ISA points (6486) while bimaxillary surgery or
free flap transfer gives less than 2500 points. In conclusion, the use of the
PMSI to allocate financial means can be extremely dangerous for maxillofacial
surgery units and consequently for the quality of the medical care in our
Specialty. Further studies are obviously necessary to complete a critical
analysis of the current system and to improve it.
PMID- 10672647
TI - [The P.M.S.I. and maxillofacial surgery].
PMID- 10672648
TI - [Arteriovenous malformations in the jaws. The place of intravascular therapy.
Apropos of 14 cases].
AB - PURPOSE: To analyze arteriovenous malformations (AVMs) of maxillo-mandibular
arcades seen in our department since 1977, and to determine adequate treatment.
MATERIAL AND METHODS: Fourteen AVMs were reviewed to determine their revelation,
their semiology, the treatment applied and the results that could be obtained.
All these lesions were true AV shunts involving bone with or without soft tissue
extension. RESULTS: Eight patients belonged to the pediatric population. Six
lesions were maxillary and 8 mandibular. All lesions were revealed during or
after puberty by local swelling, pain, mass effect or bruit. Hemorrhage was the
most frequent (71%) symptom. Teeth instability was detected in all these patients
and was origin of the bleeding. The lesions were suspected clinically and
confirmed radiologically. Angiography analyzed properly the architecture of the
lesion (4 arteriovenous fistulas). Embolization was the clinical treatment in all
patients: particles helped to stabilize the acute situations but failed to offer
stable results, necessitating complementary embolizations and/or surgery
(hemimandibulectomy in 2 patients). The use of acrylic glue (Histoacryl),
injected percutaneously (5 patients), or transarterially in the AVM (4 patients))
provided cure in 6 of these lesions (43%) and long term stabilization for all the
other AVMs. Teeth extraction could be performed thereafter in good conditions.
Antibiotics and anti-inflammatory treatment helped to stabilize the evolutive
risk of these lesions. CONCLUSION: Embolization is the therapy of choice in these
lesions. Appropriate use of glue offers a high rate of cure and/or clinical
stabilizations and avoids unneeded surgery.
PMID- 10672649
TI - Antimicrobial effectiveness of 2% glutaraldehyde versus other disinfectants for
hospital equipment, in an in vitro test based on germ-carriers with a high
microbial contamination.
AB - 2% glutaraldehyde is the reference disinfectant for hospital instruments.
However, its high environmental toxicity makes desirable to search for
alternatives. We compare the antimicrobial activity of 2% glutaraldehyde with
0.44% N-duopropenide (NDP), 0.66% NDP in 48 degrees alcoholic solution (NDP-alc),
0.13% glutaraldehyde-phenate, 1% or 3% persulphate (Virkon) and 0.1% or 0.5%
chlorhexidine, using a model that mimics non-regular surface instruments
contaminated with microbial strains (44 bacteria, 6 of which were Mycobacterium).
The contaminated carrier is soaked in the disinfectant solution. After 5 or 20
minutes contact the disinfectant is neutralized. The overall results on all
microorganisms in 20 minutes, show similar antibacterial activity for 2%
glutaraldehyde and 0.66% NDP-alc, followed by 0.44% NDP and after by the two
concentrations of Virkon and 0.5% chlorhexidine. The 0.13% glutaraldehyde-phenate
and 0.1% chlorhexidine exhibited significantly less effect than any other
disinfectant. 0.66% NDP-alc was faster antimicrobial activity than 2%
glutaraldehyde, destroying totally the inoculum in 5 minutes. Activity on
Mycobacterium showed great differences between 2% glutaraldehyde and the rest of
products (> 5 log versus < 3 log reduction in 20 minutes), with an exception: NDP
alc, with similar and faster activity (> 5 log in 5 minutes) than 2%
glutaraldehyde. With human blood, the survival microorganisms increase 0.3 log
(average) in all the disinfectants used. The aggressiveness on metallic devices
was greater in Virkon than in the other disinfectants. We conclude that NDP
(alone or in alcoholic solution) may be a good alternative to glutaraldehyde in
hospital instruments disinfection.
PMID- 10672650
TI - [Mandibular fractures in sports. Retrospective study of 48 cases].
AB - We present a retrospective study of 48 isolated mandibular fractures related to
athletic activities. We studied patient age, sex, sport involved, mandibular
location of the fracture and the therapeutic implication. The sex ratio was 4/1
and mean age 24 years. Rugby and cross-country biking were the more frequently
involved sports (79%). We recall preventive measures. Miniplate osteosynthesis
was used as often as possible in order to avoid intermaxillary fixation (IMF)
(40%) or to limit the duration of IMF. This allowed early return to sport
activities.
PMID- 10672651
TI - [Sports and facial injuries. Feasibility and limitations of an epidemiologic
study].
AB - Our aim was to conduct an epidemiological study in order to better assess the
frequency of maxillo-facial sport injuries. Only those activities that are
practised within a sport or game association are included in the study. A
standard letter was sent to all French sport and game associations (Olympic or
not) as well as to some major insurance companies (73 sport and game associations
and 11 insurance companies). However the scope of the study rapidly proved
limited since over the two-month period considered only 16 sport associations and
one insurance company returned an answer. The exploitable results are presented
and a brief overview of the recent relevant international studies is given.
PMID- 10672652
TI - [An unusual fracture of the orbital floor].
AB - The various anatomopathologic forms of orbital fractures correspond to precise
pathophysiologic mechanisms. We would like to detail an exceptional case of an
orbital fracture in professional a diver. This case can be associated to
barotraumatic accidents categories. After a brief review of the anatomy and the
pathophysiological fractures of the orbit, we examine the different mechanisms
which can be linked to this particular and unexpected pathology.
PMID- 10672653
TI - [Pulsed dye laser: principles and indications].
PMID- 10672654
TI - [Eversion carotid endarterectomy: advantages and disadvantages].
AB - A comparative analysis of results of 70 operations fulfilled by the method of
classical with autovein plasty of the internal carotid artery (ICA) and of 103
operations by the method of eversion carotid endarterectomy (CEAE) was made. The
time of compression of the carotid artery during the eversion CEAE proved to be
considerably less (22.5 +/- 6.5) min, than when using the "classical" method
(32.5 +/- 5.3) min. In the nearest postoperative period no neurological
complications of embologenic genesis or those associated with acute thrombosis of
ICA after the eversion CEAE were noted while after the "classical" method they
developed in 3 patients and 2 of them died. After the eversion CEAE 1 patients
died of myocardial infarction. In remote periods after the "classical" CEAE the
restenosis and reocclusions appeared in 6 patients, while after the eversion
method--in 3 patients. CEAE fulfilled by the eversion technique is an effective
operation reducing the amount of postoperative neurological complications as well
as of late restenosis and reocclusions. It can be used without the applying of
the internal bypass.
PMID- 10672655
TI - [Clinico-morphological evaluation of physical methods of dissection and
coagulation in stomach surgery (a preliminary report)].
AB - The article presents preliminary results of experimental investigations of
clinico-morphological alterations in the gastric wall occurring during operations
on the stomach performed with using high frequency electrosurgical apparatuses.
The authors stress the expedience of using the apparatuses with the working
frequency of electric current higher than 3 MHz for the abdominal surgery.
PMID- 10672656
TI - [Motor-evacuation disorders of the digestive tract in the early period after
stomach surgery. 3. Motor-evacuation disorders of the large intestine].
AB - The balloonographic method was used for studying the motor function of the
sigmoid in 15 healthy volunteers, 15 patients with peptic ulcer before operation
and in 25 patients at early terms after truncal vagotomy or resection of the
stomach. During the first 2-3 days independent of the type of surgical
intervention and of the degree of extra-organic denervation of the digestive
tract, the motor activity of the sigmoid has the autonomic regimen of regulation,
pathognomic structure of the motor cycle and is characterized by a sufficiently
high contractile activity at the expense of frequent and regular generation of
the migrating motor complexes. The restoration of the motor function is completed
by the 5th-6th day. The states of normo-, hypo- and adynamia of the sigmoid were
established on the basis of the contraction activity coefficient. The functional
motor-evacuatory disorders of the intestine of the middle and grave degree are
always accompanied by hypodynamia and transitory adynamia of the sigmoid.
PMID- 10672657
TI - [Pancreatoduodenal resection in cancer of the head of the pancreas].
AB - The nearest results of surgical treatment of 375 patients with carcinoma of the
pancreatic head and of 104 patients with cancer of other organs of the
pancreatoduodenal area are described. Radical operations were made on 62 of them.
Resectability was 16.5%, lethality--9.7%, postoperative complications were noted
in 35.5% of the patients.
PMID- 10672658
TI - [Cytoreductive surgery in the treatment of stage IV colorectal cancer].
AB - An analysis of immediate and long-term results of treatment of 34 patients with
colorectal cancer of the IV stage has shown the expedience of cytoreductive
operations in combination with postoperative chemotherapy and immuno-correction.
Such complex treatment allows to increase the average survival to (27.8 +/- 4)
months.
PMID- 10672659
TI - [Ways of improving the results of surgical treatment of colonic obstruction of
tumorous genesis].
AB - The work presents results of examinations and treatment of 522 patients with
intestinal obstruction due to stenosing cancer of different parts of the colon.
Operations were performed on 486 (93.1%) patients. It was established that the
widening of indications to radical operative interventions on patients of all age
groups independent of the level of localization of stenosing cancer of the colon
was one of perspective ways for the improvement of results of surgical treatment.
In patients with the acute obstruction of the left half of the colon it is
expedient to complete radical operations making primary anastomoses.
PMID- 10672660
TI - [Hemodynamic characteristics of the state of musculo-venous pump of the lower
limbs and pelvis in patients with varicose veins].
AB - The method of phlebotonometry developed by the authors was used in an analysis of
results of the state of musculo-venous pump of lower extremities and pelvis in
106 patients with varicose disease. The dynamics of phlebotonogram indices was
studied during isolated functional exercises of the muscles of prelum abdominale,
femur, leg and foot. In the first and second stages of the disease the function
of both the single pumps and the whole pump system is disturbed but mildly and
has no stage distinctions. Their pronounced impairment appears but in cases of a
complicated course of the disease. In valvular incompetence of deep veins the
musculo-venous pump looses its function: the greater the degree of valvular
incompetence, the worse the functioning of this structure.
PMID- 10672661
TI - [State and prospects of the development of war traumatology and orthopedics].
AB - The article deals with the achievements of the department of military
traumatology and orthopedics in treatment of different traumas of the locomotor
system, complications of these traumas and with different questions of treatment
of orthopedic pathologies. It is shown that organisation of specialized
orthopedic-traumatological centers in the system of military forces is necessary.
PMID- 10672662
TI - [Injuries of the duodenum].
AB - During 10 years there were 94 patients aged 16-68 years with injuries of the
duodenum. Their case histories were studied in order to establish the causes of
complications and lethality. Among them there were 48 patients with knife wounds,
5 patients with gunshot wounds, closed trauma of the abdomen was diagnosed in 40
patients, 1 patient had a iatrogenic wound of the duodenum. There were 17
isolated injuries of the gut and 77 combined and multiple injuries. Patients with
traumatic perforations in the duodenum made up 89.4%, 31% of them died. In 70
patients suture of the duodenum was put during operation, 10 patients had sutures
and intubation of the duodenum, in 6 patients the injured gut was excluded, in 1
patient resection of the duodenum was made and primary anastomosis was formed. 28
patients (29.8%) died. Among the causes of the deaths were non-compensated blood
loss resulting from hemorrhage from the vessels of the liver and other organs,
combined and multiple injuries. Pyo-septic complications led to death of 12
patients, duodenal fistula was found in 4 patients. An analysis of the material
has shown that most patients with traumas of the duodenum could be cured by
suturing the incised or lacerated wound of the duodenum. Exclusion of the
duodenum is thought to be a helpful addition to operation on the injured
duodenum, especially on large wounds. Pancreatoduodenectomy is necessary but
seldom in surgery of such traumas.
PMID- 10672663
TI - [Fractures of the zygomatic-orbital complex: diagnosis and choice of the
treatment method].
AB - The article presents an analysis of surgical treatment of 113 patients with
fractures of zygomatic-orbital complex. Operations were fulfilled on 77 patients
with using miniplates from titanium, on 25 men with application of the
osteosuture, in 7 cases with a combination of the osteosuture and the miniplate,
intrasinusal fixation was done on 4 patients. The problem of using computer
tomography in a pilot survey of the patients is considered. A possibility to
apply absorbable polymeric seam material (PDS-II) was shown in 24 observations.
PMID- 10672664
TI - [Surgical treatment of patients with injuries of the spine of the thoracic and
lumbar localization].
AB - Surgical treatment of 276 patients with uncomplicated (71.7%) and complicated
(28.3%) injuries of the spine of the thoracic and lumbar localization was taken
as the material for the article. The authors propose a rational strategy and
tactics of operative treatment of patients with traumas of the spine and also
they make an assessment of efficiency of some new surgical technologies. The
volume and optimum terms of the decompressive-stabilizing operations on the spine
are determined depending on the kind of the vertebral injury and the general
state of the patient. The effectiveness of the present-day systems of
stabilization of the spine (transpedicular constructions and plates for the
frontal fixation of the spine) was demonstrated.
PMID- 10672665
TI - [Characteristics of differential diagnosis and tactics of treatment of patients
with fractures of the condyles of the femur and tibia].
AB - The author has shown that the traditional conservative and operative methods of
treatment having a great number of unsatisfactory results and long period of
treatment do not conform to the tasks which, in the ideal variant, must result in
liquidation of consequences of the injury. Moreover, one of the main elements of
these methods of treatment--continuous plaster immobilization--should be
recognized as contraindicated. The program of treatment should include the use of
special apparatuses allowing the reposition, firm lateral compression of the
fractured fragments without an additional external immobilization, early
movements in the injured joint which make optimum conditions for the
consolidation of the fracture and simultaneous restoration of the joint function.
PMID- 10672666
TI - [Hemorrhage in cerebral gliomas].
AB - A study of 48 clinical cases with supra- and subtentorial localization to reveal
poor prognostic factors leading to intratumoral haemorrhage is offered.
Haemorrhage most frequently occurs in patients older than 40 years and
characterized by insult-like course. Poor prognostic factors of such condition
are: astrocytic type of structure, giant size of tumor, cystic degeneration, high
vascularity and partial removal of the tumour.
PMID- 10672667
TI - [Injuries the esophagus].
AB - An experience with treatment of 30 patients with ruptures of the esophagus of
different genesis is generalized. The differentiated approach to choice of the
method of treatment and character of surgical procedures, wider indications to
plastic interventions on the esophagus wound with its suturing layer-after-layer,
wide disclosure of the mediastinum and its purposeful drainage, use of the modern
detoxication means favoured the achievement of quite satisfactory results of
treatment. Lethality was 6.7%.
PMID- 10672668
TI - [Effects of ultraviolet irradiation of blood and sodium hypochlorite on aromatic
amino acid metabolism in phlegmons of the maxillofacial region].
AB - The investigation was performed in 39 patients with the severe course of
phlegmons of the maxillofacial area. The concentration of the phenyl-pyruvic and
para-hydroxyphenyl-pyruvic acids in the diurnal urine was found to be elevated
which suggested the disturbed functional state of the liver. Treatment including
the ultraviolet irradiation of blood and sodium hypochlorite resulted in rapid
normalization of the level of para-hydroxyphenyl-pyruvic acid and in lower
concentration of phenyl-pyruvic acid.
PMID- 10672669
TI - [Sphincter-valve gastroduodenal anastomosis in surgery of stomach ulcer].
AB - A method of gastroduodenoanastomosis has been developed which allows exclusion or
considerable reduction of the pathological effect of the duodenogastric reflux
upon the gastric stump mucosa after distal resection of the stomach in patients
with gastric ulcer. Complex examinations of the patients after operations have
shown that the developed by the authors sphincter-valvular
gastroduodenoanastomosis facilitates the rhythmic-portion evacuation of the
gastric contents and prevents the reflux of the duodenal contents into the
gastric stump.
PMID- 10672670
TI - [Does a sector resection of the breast cure nodal mastopathy?].
AB - Results of the clinico-morphological investigation of 265 patients with localized
mastopathy who were submitted to sectorial resection showed that in the margins
of the operative wound there were morphological signs of mastopathy in 252
(95.1%) patients. The results obtained confirm the opinion that structural
alterations of the tissues known to be the essential feature of fibroadenomatosis
can not be local, they are of diffuse character. So, the sectorial resection
performed for localized mastopathy can not be radical and is of no therapeutic
significance. The indication to surgical intervention must be determined not so
much by the necessary treatment as by the real risk of hypo-diagnosis of breast
cancer. So, there is no need to fulfil the sectorial resection for localized
mastopathy. It is enough to make operation of less volume (excision biopsy).
PMID- 10672671
TI - [Mediastinal lymphosarcoma complicated by recurrent hydropericardium].
PMID- 10672672
TI - [Effectiveness of the use of solcoseryl in intensive therapy of hemorrhagic
shock].
PMID- 10672673
TI - [Two-stage rupture of the spleen].
PMID- 10672674
TI - [Aneurysm of the splenic artery in liver cirrhosis and portal hypertension].
PMID- 10672675
TI - [Perforation of the Meckel's diverticulum by a pine needle].
PMID- 10672676
TI - [Incarcerated right-sided direct inguinal hernia with incarceration of the
Meckel's diverticulum and necrosis of its apex].
PMID- 10672677
TI - [Deontological views of surgeons-angiologists (data of a sociological
questionnaire)].
PMID- 10672678
TI - [Development of surgery in the Sakha Republic (Iakutia) during the last 75
years].
PMID- 10672679
TI - [The results of the scientific activities of the organizations under the Ministry
of Public Health of Ukraine in 1998].
AB - Data are submitted on the scientific potential of the system of the Ministry of
Health of Ukraine, its constituent parts, some features of financing and volume
of scientific research work done in 1998. Results are presented of scientific
investigations in basic fields of medicine and priority lines of activity of
medical science. The importance of introduction of scientific developments into
the health care practice is emphasized. Prerequisites for further development of
sectorial medical science under present-day social and economic conditions are
analyzed.
PMID- 10672680
TI - [The clinical course and histological characteristics of medullary hematopoiesis
in acute leukemia in those who worked in the cleanup of the aftermath of the
accident at the Chernobyl Atomic Electric Power Station].
AB - The course is analyzed of myeloblastic leukemia in twelve participants in the
elimination of the aftermath of the Chernobyl Atomic Power Plant breakdown. The
iliac trepanobiopsies bone-marrow hemopoiesis is studied. A gross depression of
normal hemopoiesis has been revealed together with a fibrous transformation of
the bone marrow, which fact suggests a profound damage to the hemopoietic micro
surroundings, being a cause of ineffective hemopoiesis, of grave course of the
illness, and of failure to respond to cytostatic therapy.
PMID- 10672681
TI - [The immunohistochemical determination of p53 and of proliferating cell nuclear
antigen in the epithelial nuclei of benign prostatic hyperplasia following the
accident at the Chernobyl Atomic Electric Power Station].
AB - With the purpose of studying into the morphogenesis and proliferous activity of
the prostatic epithelium under a long-term exposure to low doses of ionizing
radiation there have been conducted comparative histological and
immunohistochemical (expression of p53 and proliferous cellular nuclear antigen
PCNA) investigations designed to study benign prostatic hyperplasia in patients
living in those Ukraine territories affected by radionuclide contamination (group
III), residents of Kiev (group II), and patients having been operated on before
the Chernobyl accident, having constituted the control group I. It has been found
out that the incidence of prostatic intraepithelial neoplasia (PIN), the level of
nuclear expression of proteins p53 (in the PIN epithelium) and PCNA (in the
epithelium of both benign prostatic hyperplasia and PIN) of patients in groups II
and III are by far higher as compared with those in group I. The stroma of benign
prostatic hyperplasia in patients of groups II and III was clearly different from
that in the control group in that the former was characterized by apparent
phenomena of hyalinosis, sclerosis, fibrosis, and extensive inflammatory
infiltration, which changes can be explained by a long-term systematic exposure
of prostatic tissue to low doses of ionizing radiation.
PMID- 10672683
TI - [The sanogenic effects of reflex acupuncture therapy in regard to the
pathogenesis of hypertension].
PMID- 10672682
TI - [The importance of endothelin-1 in regulating the functions of the cardiovascular
system].
PMID- 10672684
TI - [Helicobacter pylori in the etiology and pathogenesis of chronic diseases of the
digestive tract].
PMID- 10672685
TI - [The biological properties and clinical significance of interleukin-8].
PMID- 10672686
TI - [The clinical problems of autoimmune thyroiditis].
PMID- 10672687
TI - [The characteristics of left ventricular remodelling in hypertensive heart
patients and the possibilities for its drug correction].
AB - In 85 patients with mild and moderately severe arterial hypertension presenting
with signs of hypertensive heart, processes of remodelling of the left ventricle
(LV) of the heart were studied using combined echocardiographic criteria. An
evaluation was done of effects of different groups of antihypertensive drugs on
the revealed changes in the LV structure and geometry. The patients were divided
into four groups depending on the antihypertensive drug taken (atenolol, cozaar,
norvask, enalapril). All groups patients were found to derive benefit from a 4
month monotherapy: against the background of normalization of arterial pressure
(AP) structural-and-geometric indices for LV have gotten improved together with
those for pulmonary gas exchange. The antagonist of receptors to angiotensin-II
(cozaar) and the inhibitor of the angiotensin-converting enzyme (enalapril) were
found to be the most efficacious drugs in the correction of the revealed
disturbances. Improvement in LV geometry and regression of its hypertrophy were
not directly related to AP normalization, witch fact indicates that there is no
relationship between antihypertensive and cardioreparative activities of the
drugs studied.
PMID- 10672688
TI - [The mechanism of the development of a fat microembolism in myocardial infarct].
AB - It was found out with the aid of morphological methods that during the acute
phase of myocardial infarction there develops fat embolism of the vascular bed of
not only pulmonary circulation but also systemic circulation. One of the sources
of fat embolism is the degenerated myocardium: during the process of its
contraction fat drops move out of the cardiomyocytes and may penetrate into the
capillary network.
PMID- 10672690
TI - [The use of angiotensin-converting enzyme inhibitors in patients with chronic
glomerulonephritis].
AB - Results are analyzed of a prolonged treatment with inhibitors of the angiotensin
converting enzyme (captopril, Capoten, 100 to 150 mg daily, Renitec, 10 to 20 mg
daily) in 53 patients with chronic glomerulonephritis. Of these, 23 patients
presented with nephrotic syndrome in prehypertensive stage, 30 were in the stage
of chronic renal insufficiency. The time-related course of proteinemia was
studied as were indices for systemic hemodynamics, azotemia. Shown in the study
was a significant effect of ACE inhibitors on proteinuria, indicators of systemic
hypertension. A tendency toward decline in indices for creatinemia was noted. A
concept is considered of multifactor effect of ACE inhibitors resulting in
inhibition of progression of renal insufficiency.
PMID- 10672689
TI - [Dynamic interphasic tensiometry of the blood in chronic hepatitis and liver
cirrhosis].
AB - Studied with the aid of the computerized tensiometer MPT2-Lauda (Germany) was
dynamic surface tension (ST) of blood serum in patients with chronic hepatitis
(ChH), hepatic cirrhosis (HC), and in essentially healthy people, with n = 44,
32, and 68 respectively. ChH was shown to be accompanied by a significant
increase in ST indices in the region of short (t = 0.01 sec) times of the surface
life as well as by a decrease in that of medium (t = 1 sec) and long (t-
>infinity) times. Rise in parameters of interphase tensiograms is a prognosis
negative sign with respect to the development of HC. Correlations have been
established of indices of blood ST to its content of protein, lipid, and
inorganic substances and to morphological signs of affection of the liver as
well.
PMID- 10672691
TI - [The communicative form of sexual dysadaptation in neurosis in men].
AB - Forty-one couple with the communicative form of sexual dysadaptation including
sexual aversion in which men suffered from different forms of neurosis
(neurasthenia, hysteric neurosis, obsessional neurosis) were examined using the
method of systems-structural analysis. The results of the studies made revealed
causes and mechanisms of development of the considered form of sexual
dysadaptation, with manifestations and consequences of the above dysadaptation
related disorders of sexual health of the family described in some detail. A
relation was found out between the form of neurosis in men and development of
sexual dysadaptation. The necessity is substantiated to consider the revealed
regularities in making a diagnosis or performing a correction of aversion in male
subjects with neurosis.
PMID- 10672692
TI - [Ultrasonic dopplerography in the diagnosis of vascular headache in children
against a background of thiotriazoline treatment].
AB - Overall twenty-four children aged 10 to 15 years suffering from headache were
examined. Doppler sonography technique employed in the study of vessels of the
brain and spine reveals a high level of anomalous vessels of the brain and spine
in the absence of manifest hemodynamic disturbances in the arterial bed of the
vertebral artery and in apparent changes in the venous system. Those patients
with headache having been exposed to thiotriasoline treatment demonstrated a
positive dynamics of indices for the venous circulation as evidenced by
dopplerography.
PMID- 10672693
TI - [Computed tomography of the brain in suppurative meningoencephalitis].
AB - The studies made showed that one-tenth patient with purulent meningoencephalitis
(PME) needs to be examined by axial computerized tomography (ACT) techniques. The
following items are indications for ACT: apparent or progressive neurological
symptomatology, protracted or relapsing course of PME, formation of the
intracranial liquor hypertension, apparent changes in echoencephalography, and
congestive disorders in the eyegrounds. Brain ACT permits finding a relevant
policy of treating patients (surgery or conservative option) together with
predicting the course and outcome of PME.
PMID- 10672694
TI - [The possibilities for preventive diagnosis and nondrug treatment in drug
allergy].
AB - The paper is dedicated to the matter of topical interest--that of diagnosing
allergic reactions during the preclinical stage and of potentialities of clearing
away adverse reactions to drugs without employment of medicinal agents. A
characteristic feature of the paper is an original approach based on the authors'
method. Reflected in the table are observations of the authors in respect of six
entities versus analogous diagnosis without allergy and essentially healthy
subjects--blood donors. The development of allergy is accompanied by a striking
augmentation of CIC, which fact is to be considered in routine medical practice
as a diagnostic criterion to be used together with the tests suggested by the
authors.
PMID- 10672695
TI - [An analysis of surgical treatment methods in femoral neck fractures based on a
patent information search].
AB - Patent inventive discoveries in the USSR over the period 1949-1989 are analyzed
together with the world patent discoveries, inventions, designs (Ukraine since
1989 included) over the period 1978-1998, which are divided into several groups
different in principle, criteria of analysis are singled out, new notions of
"cruel", dosage, dynamic compression are determined. By making use of principles
of biological low-invasive metallo-osteosynthesis and new notions of "cruel",
dosage, and dynamic compression optimal options were found for fixation of
fractures of the femoral neck: low-traumatic nail set in the neck at an angle of
130 degrees fit with a small-sized diaphyseal put-in lamina and a local
stimulation of union or spongiosa for the neck of the femur screw with an
attachment preventing caput femoris rotation, and a springy element combined with
a small-sized diaphyseal put-in lamina (that is, a modified system of the dynamic
screw for the neck of the femur).
PMID- 10672696
TI - [The conservative treatment of trophic soft-tissue lesions in patients with
inveterate complicated spinal trauma].
AB - The paper presented is based on the analysis of 216 patients who had suffered a
complicated spinal injury presenting with trophic lesions of soft tissues. The
above pathology is found with very high frequency in patients with a severe
degree of the spinal cord injury (groups A, B, C, and D according to Francel).
Large soft tissue trophic lesions are long noted to be present being
characterized by a high degree of microbial contamination. Our objective in this
study is improvement of results of treatment of patients with a complicated
spinal injury and the presence of trophic lesions of soft tissues with the aid of
conservative methods of treatment such as electrostimulation and external laser
therapy. A positive result of treatment was recordable in 30.9 percent of cases.
PMID- 10672697
TI - [The effect of vertebral artery deformation by the osteophytes of uncovertebral
areas on cerebral hemodynamics].
AB - Based on the analysis of 37 cases, an ultrasonic picture is described together
with the character of a change in dopplerographic indicators in compression of
the vertebral artery from osteophytes of the uncovertebral regions. In most cases
(94.6%) the deformation is not accompanied by a hemodynamically significant
compression (stenosing) of the artery and does not affect the indices for the
intracranial bloodflow. The vertebral artery deformation from osteophytes affects
parameters characterizing cerebral bloodflow when it is associated with other
pathology. Movements in the cervical region of the spine do not increase
compression of the vertebral artery from osteophytes of the uncovertebral region.
Significance of the vertebral artery compression in the extracranial region can
be adequately assessed mostly by indices for intracranial bloodflow. Thus, some
other factors or their association that are most often not taken account of can
play the leading part in the development of cerebral vascular insufficiency, such
as occlusive lesions, deformations of arteries, anomalies of development, reflex
vascular pathology etc. As a matter of fact, it is on extremely rare occasions
that osteophytosis has a pronounced hemodynamically significant effect on the
vertebral artery, it is not considered to be the only cause of cerebral
circulatory disorders in people under 58-60 years of age.
PMID- 10672698
TI - [The use of differential reflectometry in the EHF range as a new method in the
diagnosis of ischemic heart disease].
AB - Described in the article is a new method of EHF differential reflectometry for
ischemic heart disease (IHD), which relies on measurement of the anisotropy
factor (AF) in sites of precardiac integumentum of patients in the millimeter
range. A total of 30 patients were examined divided into six groups according to
different functional classes. It is for the first time that anisotropy zones have
been identified in IHD patients. The reflexogenic zone in the III intercostal
space along the parasternal line was found to be of the most informative value.
It is in this very zone that the largest AFmax values are achieved for myocardial
infarction (MI) group exceeding the corresponding values for the rest of
stenocardia groups by 20 to 100%. It follows from the foregoing that our method
of MM-reflectometry permits diagnosing IHD together with differentiating the
state of those patients presenting with angina pectoris and MI.
PMID- 10672699
TI - [The medical rehabilitation characteristics of patients after therapeutic
prophylactic operations in the early stages of rheumatoid arthritis].
AB - Overall 119 treatment and prophylactic operations were performed on those
patients in early phases of rheumatoid arthritis who derived no benefit from a
combined conservative treatment. With preliminary medial instability of the joint
in 19 patients the surgical intervention involved some elements making for
reinforcement of the capsular ligamentous apparatus. Good results of the above
operations occurred in 78% of cases. Relapses of synovitis were encountered in
eight percent of cases, which fact is related to the generalized advancing
disease. Satisfactory results were obtained in those patients (14%) who were free
from the origination of synovitis, which fact can be explained by lack of an
efficient system of complex medical rehabilitation in the outpatient stage. A
scheme is suggested of medical rehabilitation after treatment and prophylactic
interventions for patients with early stages of rheumatoid lesions of the knee
joint, that permits improving results of treatment in the above category of
patients.
PMID- 10672700
TI - [Intrathoracic compression of the respiratory tracts caused by broncho- and
enterogenic mediastinal cysts in children].
AB - Over the period 1983-1999 examination was done together with a surgical treatment
of ten children with bronchogenic (BG) and enterogenic (EG) cysts of the
mediastinum, their ages ranging between 2 months to 13 years, having been kept
under medical surveillance in the clinic for thoracoabdominal surgery of
developmental anomalies in children. In 80 percent of patients intrathoracic
compression of the respiratory tracts caused by the above cysts was diagnosed.
87.5 percent of patients had inflammatory bronchopulmonary problems, 12.5 percent
had secondary tracheomalacia as complications of BG and EG cysts. BG and EG
complications of the mediastinum affect the outcome of surgical treatment.
PMID- 10672701
TI - [The comparative characteristics of the autonomic indices of the cardiovascular
system in patients with combined gastroenterological diseases].
AB - As many as 32 patients with associated pathology of the digestive system were
followed up. Studied in the above series was the cardiovascular system vegetal
regulation-depended bodily adaptability. Those patients suffering from chronic
gastroduodenitis with concurrent chronic cholecystitis and chronic pancreatitis
were found out to have more manifest reactions of compensation and adaptation
than patients presenting with duodenal ulcer with concomitant chronic
cholecystitis and chronic pancreatitis.
PMID- 10672702
TI - [The differential diagnostic laparoscopy of acute appendicitis and acute diseases
of the internal genitalia in women].
AB - A total of 350 diagnostic laparoscopies were performed in the patients, we
suspected, had acute appendicitis or acute surgical pathology of organs of the
true pelvis. In patients with uncertain clinical signs laparoscopy yields a
valuable information that allows the significant differential diagnosis to be
carried out, with the optimal variant of the policy of treating patients to be
selected in a timely fashion.
PMID- 10672703
TI - [The characteristics of the course and treatment of caseous pneumonia in diabetic
patients].
AB - Highlighted in the paper are particular features of the clinical course of
caseous pneumonia in 18 patients with diabetes mellitus. An inter-aggravating
character of the two illnesses is shown, especially in those patients presenting
with a grave form of diabetes. The majority of patients have not derived much
benefit from intensive chemotherapy against the background of alimentary therapy
and insulinization. We consider it important to carry out surgical treatment in a
timely fashion in a combined therapy of the above patients.
PMID- 10672704
TI - [An analysis of the manifestations of the side effects of low-frequency
ultrasonic therapy in pulmonary tuberculosis patients].
AB - It has been ascertained that employment of low-frequency ultrasound therapy in
patients with pulmonary tuberculosis may provoke the appearance of such side
effects as total and focal reactions. These side events are of temporary
character, they are not considered to be contraindications to continuation of
treatment with ultrasound. The focal reaction needs to be assessed x-ray
carefully since its appearance can provoke aggravation of the specific process.
PMID- 10672705
TI - [The efferent substitution correction of blood trace element disorder in patients
with chronic kidney failure].
AB - Reasons are given for expediency of correction of dystraceelementemia in chronic
renal insufficiency. Following exposure to the treatment with the
multivitaminotraceelement drug three-we PLUS and alpha-erythropoietin eprex
patients with terminal renal failure prolonged by chronic hemodialysis (n = 16)
demonstrated a decrease in blood concentration of toxic trace elements and in
dysbalance of essential trace elements, alleviation of clinical symptoms,
increased tolerance to physical loads, improvement of hematological indices and
quality of life.
PMID- 10672706
TI - [The short-term effect of measured normobaric hypoxia on autonomic nervous system
function in persons with hypo- and hyperacidic syndromes].
AB - The functional activity of the vegetative nervous system was studied before and
after the exposure to graded normobaric hypoxia having been realized as breathing
with an artificial hypoxic mixture (AHM) during 10 to 40 minutes in subjects
presenting with hypo- and hyperacidic syndromes. A relationship was established
between activation of the sympathetic or parasympathetic regions and aggravation
of the antecedent history (bad habits). It is suggested that a short-term AHM
breathing be used as a test for preservation/failure of mechanisms of adaptation.
PMID- 10672707
TI - [The forensic psychiatric expertise of patients with epilepsy of traumatic origin
and moderately pronounced mental disorders].
AB - A total of 17 patients were examined with epilepsy of traumatic genesis
presenting with moderately severe mental disorder and unfavourable course of the
illness. Criteria were defined more exactly of forensic psychiatric assessment of
chronic mental disorders in this most challenging "borderline" (in the expert
respect) group of patients. Established in these cases were conditions of use of
juristical (psychological) criterion of the diminished responsibility formula:
the presence of manifest changes in the personality with moderately severe
("borderline") deterioration of intellect, social and occupational disadaptation,
predominance of psychopathological mechanisms in behaviour of patients including
those during their committing illegal actions, rapidly progredient type of
epilepsy course, and chronic alcoholism going in with the underlying condition.
PMID- 10672708
TI - [The complex diagnosis and treatment of sexually transmitted infections and their
complications].
AB - The article is dedicated to problems of diagnosis and treatment of those
infections transmitted by sexual intercourse (STI) and their complications. A
well-advised and feasible scheme of examining patients having applied for medical
advice is suggested. Principal groups of drugs are described together with
particular representatives of the above groups, the use of which will, we
believe, help in delivering medical care to STI patients in a most efficient way.
Levels of quality of delivering medical services are worked out depending on
optimality of employment of different groups of drugs and their combinations in
the treatment of STI and complications thereof. The data obtained during the
studies made are to be used in the following circumstances: prescription by
medical practitioners of particular schemes of STI treatment; control of quality
of the health services delivery in medical settings dealing with those patients
presenting with STI and complications thereof; planning of drug purchases by
medical institutions providing profile medical care.
PMID- 10672709
TI - [The effect of transcranial electroanalgesia on the neurophysiological indices in
patients with cerebral venous dystonia].
AB - In the paper, results are presented of investigation into the effects of
transcranial electroanalgesia (TCEA), a novel nonmedicamentous method of
treatment, on certain neurophysiological parameters in patients with cerebral
venous dystonia. TCEA is shown to be an efficient treatment option in the above
group of patients.
PMID- 10672710
TI - [The effect of chronic alcoholic intoxication on the development and course of
diphtheritic polyneuropathy].
AB - The article reports in some detail on pathogenetic features of affections of the
nervous system in those persons overindulging in alcohol. It is shown that the
existing pathologies in the nervous system of the above patients get strikingly
aggravated in diphtheria. Investigations designed to study the impact of chronic
alcohol intoxication in 30 diphtheria patients overindulging in alcohol showed
that there was a high case-fatality rate among persons falling into this category
secondary to affections of the nervous system. Also common in this patient
population were early developing grave lesions presenting as associations of the
bulbar syndrome and peripheral disorders.
PMID- 10672711
TI - [The effect of the initial level of immunity on the efficacy of antidiphtheria
inoculations in children and adults].
AB - Based on results of examination in the passive hemagglutination test of 1440
subjects at different ages, several distinguishing features were revealed of
formation of artificial active antidiphtheria immunity depending on the basic
level of immunity. Single revaccination of those subjects presenting with the
basic immunity of less than 0.03 IU/ml provides defence against diphtheria in
only 33.3 percent of adults and 50 percent of children, in those subjects
presenting with immunity between 0.03 to 0.99 IU/ml it is highly effective, in
the immunity 1 IU/ml and beyond the effect of further immunization is very low
since 25 to 33.3 percent of subjects demonstrate enhancement of immunity, whereas
16.7 to 25 percent show lowering of it. The analysis of the immunological
structure of the population shows that 45 to 60 percent of adults in different
age groups need to be exposed to single revaccination, 14 to 37 present will find
it insufficient, 3 to 36 percent redundant. We suggest that revaccination against
diphtheria be conducted under control of the level of antitoxic immunity.
PMID- 10672712
TI - [The systems analysis of protective-adaptive reactions in immunopathology].
AB - In the systems approach to the study into the closed control circuits (CCC) of
the self-regulation apparatus two combinations have been established of
functioning (variable) quantities. A decrease in somatotropin and hypoglycemia
and correspondingly an increment in somatostatin and insulin determine the
redundant measure of defence against injury, the converse values in the analyzed
parameters determine autoimmune processes. Alternation of the above parameters
accompanied by exacerbation-remission and remission-exacerbation is directed to
securing an adaptive final effect--recovery. Apparent structural-and-functional
disturbances in certain regulators of any CCC are accompanied by persisting
pathological conditions listed for each heading.
PMID- 10672713
TI - [Hereditary predisposition in the formation of allergic diseases in children].
AB - Results are submitted of investigations designed to gain insights into the part
hereditary aggravation (HA) in respect of atopy plays in the origination of
allergic disorders (AD) in early childhood and to study objective markers of
atopy and bronchial asthma (BA). Close correlation (P < 0.01) was established
between HA and AD development, increase in the total IgE level and skin
scarification tests. In BA, manifest bronchial hyperreactivity is accompanied by
rise in total IgE, which observation can be related to their associated
inheritance.
PMID- 10672714
TI - [The use of Doppler echography in the diagnosis of diffuse toxic goiter].
AB - Echodopplerography demonstrated a significant increase in the velocities of
bloodflow and indices for the thyroid gland in diffuse toxic goiter. The presence
of the increased velocity indexes and coefficients during remission permits
predicting recurrent course of the affliction.
PMID- 10672715
TI - [Ozone hemo- and antioxidant therapy and endogenous intoxication in gestosis].
AB - The content was studied of the endogenous intoxication syndrome markers (medium
size molecules) in red cells, blood plasma and urine of patients with grave
gestoses in view of the fact that underestimation of the syndrome considered
tends to significantly narrow the broadness of pathogenetic notions about the
given pathology and to negatively influence the effectiveness of intensive
therapy of patients. Besides, the problem gets more complicated because of
pathogenetic specificities of severe gestoses (the use of the well-known methods
of detoxication is made difficult in the patients). Ozone hemotherapy as an
efferent method of detoxication and employment of antioxidant in the complex of
intensive therapy of patients with severe gestoses make for lowering the degree
of catabolic disturbances by decreasing the level of medium-size molecules in
erythrocytes, blood plasma and urine.
PMID- 10672716
TI - [The mechanisms for the loss of correction in the surgical treatment of severe
forms of scoliosis].
AB - Of the 2719 patients presenting with grave forms of scoliosis who had undergone
4377 correction operations, 85 patients demonstrated serious complications in
respect of loss of correction, with six of these having developed myelopathy in
the long-term follow-up. Causes of the above problem included failure of internal
fixation with distractors through the breakage of the construction or supporting
structures of vertebrae and disturbances in external immobilization. As to its
mechanism, loss of correction occurred because of transplant incapsulation or
rearrangement of bone and plastic material, with the Loozer's zones,
pseudarthroses, or defects in spondylodesis being developed.
PMID- 10672717
TI - [The role of determining specific pregnancy proteins in the diagnosis of
progressing tubal pregnancy].
AB - The importance was studied of measurement of certain specific pregnancy proteins
(b1-glycoproteid, SP-1, PAPP-A, PP-5) for the diagnosis of advancing fallopian
pregnancy. The data secured suggest a statistically significant decrease in SP-1
and PAPP-A concentration in tubal implantation of a fetal egg as compared to
uterine pregnancy. Changes in blood serum concentration of PP-5 in women with
different variants of the fetal egg implantation were statistically
insignificant, which fact suggests that measurement of the quantitative indices
of the pregnant women blood serum SP-1 and PAPP-A may be regarded as an
investigational method of sufficient information value to be used in detection
and differential diagnosis of progressive pregnancy in a timely fashion.
PMID- 10672718
TI - [The clinico-hemodynamic effects of losartan in treating patients with chronic
heart failure].
AB - Clinical and hemodynamic effects were studied of the blockader of AII receptors
lozartan in patients with chronic cardiac insufficiency (ChCI). Inclusion of
losartan into the conventional therapy of ChCI is accompanied by a lowering of
the functional class in patients and improvement of haemodynamic maintenance of
the physical exercise performance as evidenced by veloergometry. An 8-week's
course of lozartan therapy leads also to a decrease in the anterior-posterior
dimensions of the left auricle and an increase in the left ventricular ejection
fraction in ChCI patients.
PMID- 10672719
TI - [The effect of enalapril on heart rate variability in patients with arterial
hypertension].
AB - Spectral indices were studied for variability of the heart's rhythm (HRV) in
patients with arterial hypertension (AH), depending on age, degree of severity of
hypertension under exposure to the enalapril maleate therapy. In AH patients, HRV
indices suggested high risk of sudden cardial death, especially in those persons
presenting with severe AH. Under exposure to enalapril maleate patients with
isolated systolic AH, severe and moderately severe AH demonstrated changes in
their HRV indices reflecting rise in the activity of the parasympathetic section
of the vegetative nervous system, which fact can serve as a positive prognostic
index of mortality in AH patients.
PMID- 10672720
TI - [Forlax in the treatment of the constipation syndrome in children with combined
digestive organ pathology].
AB - Submitted in the paper are data on efficacy of the drug Forlax (Beaufour Ipsen,
France) in the treatment of the constipation syndrome in those children
presenting with associated pathology of the digestive system. The drug was found
out to be effective in children, its therapeutic effect being recordable over one
month in 76% of patients, which fact warrants further study of the curative
potencies of the drug in children.
PMID- 10672721
TI - [The combined treatment of calculous pyelonephritis with the use of perfusion of
the kidney cavitary system with the preparation Palisan in the postoperative
period].
AB - Results are submitted of use of perfusion of the kidney cavitary system with the
drug Palisan in the postoperative period in a multimodality treatment of
calculous pyelonephritis. On the basis of bacteriological investigations a high
efficacy of the drug in carrying out perfusion of the caliceal-and-pelvic system
in treating the inflammatory process in the kidneys has been ascertained. An
optimal methodical approach to the carrying out of perfusion has been developed.
Also emphasized in the paper is value of perfusion of the kidney cavitary system
in metaphylaxis of urolithiasis.
PMID- 10672722
TI - [The efficacy of the preparation Fastum-gel in the combined treatment of patients
with different clinical syndromes of lumbar osteochondrosis].
AB - As a result of clinical and functional investigations conducted in 47 patients
with reflex and compression and radicular syndromes of lumbar osteochondrosis
efficacy was substantiated of inclusion into the combined physiobalneological
treatment of applications with the drug Factum-gel (Berlin-Chemie, Menarini
Group). The author suggests that quantitative electromyographic determinants be
used permitting the differentiation between reflex and compression and radicular
syndromes and allowing the follow-up to be carried out of those patients
presenting with the above clinical syndromes of lumbar osteochondrosis.
PMID- 10672723
TI - [The efficacy of amizon in the combined treatment of patients with epidemic
parotitis].
AB - Efficacy was studied of a new anti-inflammatory interferon-inducing drug
preparation amizon in a combined therapy of epidemic parotiditis in 118 patients
versus the group of comparison consisting of 147 patients. A positive effect was
ascertained of the drug on clinical parameters, decrease in the incidence rate
and in severity of complications (orchitis, pancreatitis), immune indices.
PMID- 10672724
TI - [Current aspects of the classification of cholelithiasis and the principles of
the therapeutic procedure in its different forms].
AB - A classification is submitted of cholelithiasis, taking account of stages of the
illness, its main clinical forms and complications, with the diagnostic criteria
and policy of treating it being pointed out. The use of the above classification
ensures succession of surgeons' and therapists' work in questions of diagnosis,
prophylaxis, and treatment of patients with cholelithiasis.
PMID- 10672725
TI - [The classification of cystic lesions of the pancreas].
AB - The paper focuses on different classifications of cystic affections of the
pancreas. The most simplified classification is proposed to be used in routine
practice, which facilitates clinical recognition and permits the selection of
optimum, in the first place, surgical, tactics.
PMID- 10672726
TI - [The use of preparations of plant origin in treating and rehabilitating elderly
patients with chronic hepatitis].
AB - The article contains data on use of vegetal drugs Hepatofalk Planta, chicory,
Achillea millefolium in the treatment and rehabilitation of chronic hepatitis in
elderly subjects.
PMID- 10672727
TI - [The principles, levels and sources of the financing for the medical care system
under the new socioeconomic conditions (a review of the literature)].
AB - A review is submitted of home and foreign literature on the state of financing of
the medical industry. The data presented reveal modern principles, levels, and
sources of financing of public health care systems in our country and abroad. The
experience studied suggest that unification of scientific and practical
achievements of Ukraine and economically developed countries, together with
further improvements in financing of the medical industry might contribute to
formation of national efficiently functioning public health care system.
PMID- 10672728
TI - [Morbidity and temporary loss of work capacity as a consequence of arterial
hypertension in rural inhabitants].
PMID- 10672729
TI - [The pharmacoeconomics of testicular cancer in Ukraine].
AB - An ever-growing cost of health care in Ukraine attest to the need for an optimum
employment of resources in diagnosing and treating disorders of major public
health significance, testicular carcinoma (TC) among their number. The authors
consider it expedient to ascertain TC costs and design an analytical framework
for the diagnostic and therapeutic options to be assessed properly. The following
combination chemotherapy regimens were found to be associated with high response
rates and acceptable longterm survival: BEP, PE programmes for primary treatment
and PEI programme for recurrent or refractory TC. The minimum cost of the above
regimens in one course of treatment (with 2 to 4 usually prescribed) for one
patient, his height 175 cm, weight 75 kg--S = 1.9 m2, is US$ 613.0, 385.9, 813.5
for BE100P, PE100, and PEI respectively. In the Lviv region with the population
about 2,750,000 TC cytostatic therapy is estimated to be about US$ 75,168.6 this
being 62.6% of the annual budget appropriation for drug therapy of all malignant
diseases taken together. The importance is emphasized of pharmaco-economic
principles in the clinical management of patients allowing for decisions to be
made with taking account of the cost and expected outcome of the therapy
instituted.
PMID- 10672730
TI - [The age-related structure of the morbidity of background and precancerous cervix
uteri pathology].
AB - For all breakthroughs in the treatment of cancer of the uterine cervix diagnosis
of the incipient stages of malignancy still poses unique problems. The studies
made on the basis of the clinical hospital N 16 and the Oncologic Centre of the
Ministry of Health of Ukraine, histological investigations conducted on the basis
of the clinical hospital N 25 and the Ukraine MH Oncological Centre permitted the
examination of 209 women who had applied for medical advice for background and
pretumour disorders of the neck of the womb. On having done the statistical
processing of data, analysis of the secured findings was performed. The choice of
the relevant method and theoretical preparation for the regression analysis were
put through as recommended by Lakin G. F. Thus, the uterine cervix background and
pretumour morbidity has two age peaks of different degree: the first--the main
peak--falls on age 25, the second peak--that of a weaker degree--falls on age 38
years. The above two peaks fall on the active reproductive period of life (25 to
40 years of age)--just that time in women's life during which high case rates are
recordable with background and pretumour pathology.
PMID- 10672731
TI - On the theory of behavioral mechanics.
AB - The Theory of Behavioral Mechanics is the behavioral analogue of Newton's laws of
motion, with the rate of responding in operant conditioning corresponding to
physical velocity. In an earlier work, the basic relation between rate of
responding and sessions under two FI schedules and over a range of commonly used
session values had been shown to be a power function. Using that basic relation,
functions for behavioral acceleration, mass, and momentum are derived here. Data
from other laboratories also support the applicability of a power function to VI
schedules. A particular numerical value is introduced here to be the standard
reference value for the behavioral force under the VI-60-s schedule. This
reference allows numerical values to be calculated for the behavioral mass and
momentum of individual animals. A comparison of the numerical values of the
momenta of two animals can be used to evaluate their relative resistances to
change, e.g., to extinction, which is itself viewed as a continuously changing
behavioral force being imposed on the animal. This overall numerical approach
allows behavioral force-values to be assigned to various experimental conditions
such as the evaluation of the behavioral force of a medication dosage.
PMID- 10672732
TI - Psychological variables associated with adolescents' identification with
significant groups.
AB - This research describes associations of identification of 300 adolescents with
significant group concepts and variables correlated with their development such
as self-esteem, cognitive moral reasoning, and self-perceptions of personality.
PMID- 10672733
TI - Holding emotional and linguistic rulers up to the poetry of Robert Frost.
AB - The words in a large and representative sample of Robert Frost's poetry were
compared with information in several data bases which provided estimates of the
poetry's pleasantness, arousal, emotionality, imagery, and linguistic complexity.
Findings confirmed that Frost's poetry was linguistically simple and emotionally
restrained in comparison to that of his cohort. They also highlighted the
increasing variability in Frost's poetry across time and its decreasing imagery.
Frost's poetry was more restrained than that of his male cohort but similar to
the poetry of his female cohort in its linguistic simplicity. Frost's
acknowledged death poems were in fact quite pleasant and passive in emotional
tone.
PMID- 10672734
TI - Girls' fearfulness as a product of mothers' fearfulness and fathers'
authoritarianism.
AB - Data from 27 girls of 10 to 12 years were obtained on the Fear Survey Schedule
for Children--Revised and from their parents on the Fear Survey Schedule for
Adults-III and the California F Scale. Analyses indicated fathers'
authoritarianism scores and mothers' fear scores have independent associations
with children's fears and suggested greater behavioural overcontrol by fathers
and the greater propensity of mothers to communicate threatening information.
PMID- 10672735
TI - Psychosocial factors associated with peptic ulcer in aged persons.
AB - The relationship between psychosocial factors and the occurrence and aggravation
of peptic ulcer was studied in elderly people. Thirty-nine (14 male) ulcer
patients and 79 (30 male) elderly people aged 65 years and over and living in the
community were tested. Information on health status, medication, lifestyle, and
psychosocial status was obtained by means of interviews using a questionnaire and
from the clinical records of the ulcer patients. The same questionnaire was
distributed to the residents. Logistic regression analysis adjusting for age
disclosed that peptic ulcer was significantly associated with having an
occupation and low exercise practice in men. However, the relationship weakened
below statistical significance after adjusting for some physical risk factors
besides age. Low education was significant but low instrumental support fell
short of statistical significance with peptic ulcer in women even after
adjustment for several physical risk factors besides age. Thus, the specific
psychosocial factors might be independently associated with the occurrence and
aggravation of peptic ulcer in at least elderly women.
PMID- 10672736
TI - Some social correlates of homicide rates in Italy.
AB - In Italy, as elsewhere, homicide rates are higher in poorer regions. Unemployment
rates associated strongly and positively with homicide rates, explaining up to
54% of variance in regional distribution of homicide rates across the 20 Italian
administrative regions.
PMID- 10672737
TI - Perceived control, autonomy, and self-regulated learning strategies among
Japanese high school students.
AB - This study investigated relations among measures of perceived control, autonomy,
and self-regulated learning strategies for 228 junior high school (90 in Grade 7
and 138 in Grade 8) and 306 senior high school (184 in Grade 11 and 122 in Grade
12) students. Participants completed three self-report questionnaires designed to
measure control beliefs, strategy beliefs, capacity beliefs, seven types of
motivation, and two types of self-regulated strategies. Confirmatory factor
analysis identified the structure of perceived control modeled by Skinner,
Chapman, and Baltes (1988), the seven-factor structure of autonomy by Vallerand,
Pelletier, Blais, Briere, Senecal, and Vallieres (1992, 1993), and the two types
of self-regulated learning strategies by Pintrich and De Groot (1990).
Significant "grade" differences were obtained in several measures. Canonical
correlation was used to investigate the relations between perceived control and
autonomy measures. Finally, multiple regression analysis was used to investigate
the relations between perceived control and self-regulated learning strategies
and between autonomy and self-regulated learning strategies. Implications of the
results are presented.
PMID- 10672738
TI - Obsession-compulsion in college students in the United States and Kuwait.
AB - American (n = 132) and Kuwaiti (n = 204) undergraduates responded to the Arabic
Obsessive-Compulsive Scale in English and Arabic languages, respectively.
Students in Kuwait scored as more obsessive-compulsive than their American
counterparts.
PMID- 10672739
TI - Job satisfaction and intent to continue working among individuals with serious
mental illness.
AB - This study investigated the relationship between job satisfaction and the
intention to continue working in a sample of 87 individuals with psychiatric
disabilities who worked in supported or supervised employment. Data were
collected from respondents in Columbus, Ohio in 1996. After controlling for
selected correlates (education, length of employment, contract type, social
support, and attitudes concerning pay and toward work), standard multiple
regression analyses indicated that job satisfaction was a significant predictor
of intent to continue working. Analyses also indicated that respondents who
completed high school and who said that they worked primarily for the money were
less likely to want to continue working at current jobs. These findings may be
used to improve the vocational success of individuals with psychiatric
disabilities who work in supported and supervised employment.
PMID- 10672740
TI - Methodological note on use of the Center for Epidemiological Studies--Depression
Scale with older samples.
AB - Samples of older adults (ns = 600, 251, and 214) given the Center for
Epidemiological Studies--Depression Scale by telephone seem to have composite
scores that are much lower than those who are interviewed face-to-face.
PMID- 10672741
TI - Religiosity and pathology.
AB - In a sample of 109 undergraduate students, religiosity was not associated with
the fear of death or with scores on a manic-depressive tendencies scale.
PMID- 10672742
TI - Forming clinical impressions during the first five minutes of the counseling
interview.
AB - The influence of earlier formed clinical impressions of the client on later
judgments within a counseling session were examined. It was predicted that
redundancy in judgments of counselors' clinical impressions of the client after 5
min. and after 30 min. of an interview would be greater for counselor-trainees
who are (a) more self-confident about their judgments and (b) lower in cognitive
complexity, than other counselor-trainees. A stimulus tape in which a male
counselor conducted an initial 30-min. interview with a depressed female client
was shown to 80 counselor-trainees. At the 5- and 30-min. marks, the tape was
stopped, and the counselor-trainees indicated their clinical impressions of the
client. These impressions included written thoughts and ratings of clinical
characteristics of the client. Analyses showed that both their self-confidence
and cognitive complexity were not associated with differences in redundant
judgments.
PMID- 10672743
TI - Effect of reduced immunity on murine behaviors.
AB - Reduction of immunity in 11 mice of the CD1 strain by administration of
methotrexate did not alter some reliable behaviors in the open-field (ambulation,
rearing, defecation) compared with 10 matched mice injected with saline. Perhaps
moderate depression of immunity may not affect some characteristic behaviors.
PMID- 10672744
TI - Beliefs in the paranormal: age and sex differences among elderly persons and
undergraduate students.
AB - Beliefs in the paranormal were rated stronger in younger as compared to elderly
adults by Emmons and Sobal in 1981, and sex correlates of paranormal beliefs
appeared to be stronger in women than in men by Irwin in 1994. This research
studied possible linkages between age and sex with a comparative analysis between
results of Vitulli and Luper's 1998 survey among undergraduate students and data
from elderly men (M = 72 yr., SD = 9.2, n = 21) and women (M = 69.3 yr., SD =
7.7, n = 55). Crawford and Christensen's 1995 12-item Extrasensory Perception
Survey was administered to elderly persons living in apartment complexes and
private homes, participating in activities in a recreation center, or attending a
continuing-education seminar. A 2 x 2 multivariate analysis of variance from
responses on the 12-item survey showed that undergraduate men and elderly women
had the highest ratings on paranormal beliefs. The self-selecting characteristics
of a segment of the elderly sample led to a post hoc univariate analysis of
variance by partitioning that sample into those who were attending a continuing
education seminar versus all other elderly persons. Summated ratings (total
scores) for this survey showed main effects for these subsamples and for sex. Sex
and age differences were discussed in the context of the hypothesis of social
marginality.
PMID- 10672745
TI - Domestic social integration and suicide in France.
AB - In 95 French Departements in 1970, suicides rates were higher where measures of
domestic social integration (marriage and divorce rates) were greater.
PMID- 10672746
TI - Chronological age and performance of persons with mental retardation on verbal
subtests of the Wechsler Intelligence Scale for Children--Revised, French
Version.
AB - The Influence of chronological age on verbal intelligence of persons with metal
retardation was studied using the French version of the Wechsler Intelligence
Scale for Children--Revised. Participants were 1,101 children and adolescents
divided into two groups according to the severity of metal retardation. The first
group included 551 participants with moderate mental retardation, the second 550
participants with mild mental retardation. Analyses indicated a significant
association between chronological age and raw scores on the four Verbal
Comprehension subtests, even with performance on Perceptual Organization and
Freedom from Distractibility subtests held constant. This finding suggests the
relationship between chronological age and verbal intelligence is valid for
persons with moderate mental retardation as well as for those with mild metal
retardation.
PMID- 10672748
TI - Panel-touch behavior of horses established by an autoshaping procedure.
AB - Panel-touch behavior of 3 geldings was successfully established by a response
termination type of autoshaping procedure. An omission or negative contingency
introduced after the training of an animal, however, decreased the response rate
to a near-zero level.
PMID- 10672747
TI - Correlations between parents' and teachers' ratings of social skills for a group
of developmentally disabled children in Iran.
AB - Parents' and teachers' ratings of social skills and behavioural problems for 89
special education students aged 8 to 15 yr. were measured using the Social Skills
Rating System of Gresham and Elliott. The sample was selected in a school for
educable mentally retarded children in Shiraz, Iran. The low to moderate
correlations between the two sets of ratings suggest that assessment of social
skills and behavioural problems should include the use of different rating scales
in more than one setting. Sex differences were not significant for parents' and
teachers' ratings of these disabled children. The scores showed high internal
consistency.
PMID- 10672749
TI - Economic consequences and lack of respite care.
AB - The study examined the influence of a lack of availability of respite care on the
careers of 574 parents having children with disabilities. Among these parents,
there was a relationship between age of child, severity of disability, and
parents missing hours of work or passing up occupational opportunities. These
findings have implications for advocating more available and accessible respite
services and more in-depth study of the cost effectiveness of respite care on
parental income and career progression.
PMID- 10672750
TI - Children and electronic games: a comparison of parents' and children's
perceptions of children's habits and preferences in a United States sample.
AB - Despite the popularity of violent electronic games, anecdotal evidence suggests
that many parents lack even basic information about children's game-playing
habits. The goal of the present study was to examine parental knowledge of
children's electronic game-playing habits by assessing the congruence between
children's and parents' perceptions of child's playing time, parental
supervision, game preference, and reaction to actual game-playing. 35 children in
Grades 3 to 5 and one parent of each child completed a background questionnaire
and played either a violent or nonviolent electronic game. In paired comparisons,
parents reported significantly higher estimates of supervision time than
children. Most parents either named an incorrect game or were not able to guess
their child's favorite game. In 70% of these incorrect matches, children
described their favorite game as violent. Parents may underestimate their child's
exposure to violence in electronic games. After playing the same electronic game
as part of the study, parents reported significantly higher frustration than
children. Higher frustration with game-playing could contribute to deficits in
parental knowledge of children's playing habits.
PMID- 10672751
TI - The Depression-Happiness Scale: test-retest data over two weeks.
AB - The present aim was to examine further the psychometric properties of the
Depression-Happiness Scale. Test-retest data over 2 wk. are reported for this
scale for a sample of 54 female Northern Irish university students. Stability was
fairly high as r = .70, and there was no significant change between Time 1 and
Time 2 (M = 49.7 and 50.8, respectively). The data suggest that the Depression
Happiness Scale might be considered a trait measure of happiness rather than a
state measure.
PMID- 10672752
TI - Attitudes toward abortion, capital punishment, and assisted suicide.
AB - In 51 college students, attitudes toward abortion, capital punishment, and
assisted suicide were not consistently anti- or pro-death.
PMID- 10672753
TI - Smokeless tobacco use among urban white and black South Africans.
AB - A telephone survey was conducted to compare the extent of smokeless tobacco use
and perception of related health risks by white and black urban South Africans.
Using systematic random sampling, one out of every 20 phone numbers was selected
from the Seshego (blacks) and Pietersburg (whites) telephone directory until 300
tobacco users in each site were identified. Among the white group, cigarette
smoking was clearly predominant (290) and only 10 used snuff, whereas among the
black sample almost half (46.7%) of the tobacco users used snuff, especially
women (40%). Although a majority acknowledged negative effects of snuff use on
their health and its addictive character, 42% either do not believe or do not
know that snuff contains nicotine and causes cancer.
PMID- 10672754
TI - Factor analysis of the continuous performance test and parent-teacher reports of
attention deficit disorder.
AB - The relationships between a computerized measure of attention deficit disorder
and scores from two commonly used parent-teacher reports were investigated. A
factor analysis of the raw omission and commission scores provided by the
Continuous Performance Test and Conners' Parent Rating Scale and the ADD-H
Comprehensive Teacher Rating Scale indicated that for a sample of 54 children the
Continuous Performance Test was most closely associated with measures of
impulsivity and hyperactivity provided by the Conners' rating. This finding was
congruent with the use of the Continuous Performance Test in the evaluation as a
measure of Attention Deficit Hyperactivity Disorder and suggestive of a positive
and significant relation between this computerized measure of behavior and
parents' perception of behavior. Little association was detected between scores
on the teachers' scale and omission and commission scores.
PMID- 10672755
TI - Commentary on the possibility that Viagra may contribute to transmission of HIV
and other sexual diseases among older adults.
AB - Many older male adults experiencing impotence are being treated with Viagra.
Scientific and media reports indicate that this medication is effective in re
establishing sexual relationships among these men. Despite the benefits that
Viagra may have in the treatment of impotence among older adults, increased
sexual activities could also facilitate the spread of HIV infection and other
sexually transmitted diseases. This holds for older adults who may lack factual
knowledge of HIV transmission and perceive themselves as nonsusceptible to this
disease. Prescription of Viagra in combination with HIV/AIDS prevention programs
may be helpful.
PMID- 10672756
TI - A new beginning in application of Frankl's work to emerging issues in
psychotherapy.
AB - Recent interest in Frankls' system of thought, supported by Langle, paves the way
for its critical and fruitful appropriation in psychotherapy and existential
analysis.
PMID- 10672757
TI - Relation of functioning with beliefs about coping, and future time perspective.
AB - 51 college students were administered the Reasons for Living Inventory,
Zimbardo's Time Perspective Inventory, and the Environmental Deprivation Scale
Questionnaire. Pearson product-moment correlations indicated that those
functioning well (low scores on the Environmental Deprivation Scale
Questionnaire) tended to have high scores on the future subscale of the Zimbardo
Time Perspective Inventory (r = -.45, p < .001). There were no significant
correlations with the Reasons for Living Inventory's total score or its Survival
and Coping Beliefs subscale (rs = .01 and .05, respectively). The results suggest
the use of multidimensional cognitive and behavioral data to guide intervention
to improve one's level of functioning. A limitation of the study is the small
number of participants.
PMID- 10672758
TI - The Leiden Quality of Work Questionnaire: its construction, factor structure, and
psychometric qualities.
AB - Based on two leading models in occupational stress research, the Job Demand
Control-Support model and the Michigan model, a comprehensive quality of work
questionnaire, was constructed--the Leiden Quality of Work Questionnaire. The
factor structure of this questionnaire was assessed and cross-validated in two
sub-samples of 2,000 men and women from a large sample of the Dutch working
population. Analysis indicated that the questionnaire measures 11 work
characteristics of Skill Discretion, Decision Authority, Task Control, Work and
Time Pressure, Role Ambiguity, Physical Exertion, Hazardous Exposure, Job
Insecurity, Lack of Meaningfulness, Social Support from Supervisor and Social
Support from Coworkers, and the outcome variable of Job Satisfaction in a
reliable way.
PMID- 10672759
TI - Alexithymic characteristics of HIV-positive patients.
AB - Despite extensive psychiatric research on HIV-positive patients, there are no
published studies on alexithymia. Alexithymic characteristics and related factors
were examined in a sample of 81 HIV-positive patients using the modified Beth
Israel Psychosomatic Questionnaire and the Social Support of Stress and Coping
Inventory. The severity of alexithymia was significantly higher in HIV patients
than healthy controls, suggesting the presence of secondary alexithymia. Scores
on two alexithymic characteristics, affect awareness and operational thinking,
significantly correlated with ratings of poor utilization and perception of
social support. As the severity of HIV infection progressed, affect awareness was
higher, controlling for poor utilization and perception of social support. These
results suggest that secondary alexithymia, associated with poor utilization and
perception of social support, may be manifest as a state reaction to approaching
death.
PMID- 10672760
TI - Relationship between belief in good luck and general health.
AB - 62 undergraduate university students were administered the 12-item Belief in Good
Luck Scale of Darke and Freedman and the General Health Questionnaire of Goldberg
and Williams. Scores on belief in good luck showed a significant correlation of
.29 with anxiety and -.35 with depression but correlations were not significant
for somatic symptoms (.15) and social dysfunction (.15).
PMID- 10672761
TI - A cross-cultural evaluation of depression in children in Egypt, Kuwait, and the
United States.
AB - The English version of the Arabic Children's Depression Inventory, constructed by
Abdel-Khalek, was applied to a sample of 535 U.S. students (11 to 18 years old).
Cronbach coefficients alpha were .88, .90, and .89 for boys, girls, and all
subjects, respectively. Seven factors were extracted by principal axis factor
analysis (Negative mood and self-depreciation, Fatigue, Lack of loneliness, Sleep
problems, Weak concentration, Pessimism, and Feeling happy), denoting clear
factorial structure; however, the scale was intended to be unidimensional. Sex
and racial differences for this American sample were not statistically
significant but the correlation of depression scores with age was .22. The scale
appears useful in studying depression in American school children and
adolescents. Also, cross-cultural differences in childhood depression between
samples from Egypt and Kuwait of previous studies and the present American sample
were examined. Based on the effect size, female Kuwaiti had a lower mean
depression score than either the Egyptian or American groups. The scale can be
used in cross-cultural research.
PMID- 10672762
TI - Job stress among general practitioners and nurses in primary care in England.
AB - This is a description comparing job stress, job satisfaction, and mental well
being of general practitioners (n = 205) and practice nurses (n = 119) in
England, based on responses to a questionnaire. General practitioners reported
lower job satisfaction and significantly greater pressure at work than did the
practice nurses. Also, male general practitioners had significantly higher scores
on anxiety and depression than a British normative population. Practice nurses,
on the other hand, reported lower scores on anxiety and depression. The results
should be interpreted with caution as the study is based on a small sample
limited to the northwest region only; however, it does provide information which
has important implications for the well-being of doctors and nurses in primary
care.
PMID- 10672763
TI - Three screening tests for patients with psychological problems who undergo
plastic and reconstructive surgery.
AB - To investigate their quality of life, screening tests of emotion, coping with
stress, and personality were developed for use with patients in plastic and
reconstructive surgery who had psychological problems. The validity and
reliability of each test were examined in a sample of 329 patients who were
admitted to the Department of Plastic and Reconstructive Surgery. The reliability
of each test was supported by factor analysis, adequate internal consistency, and
test-retest correlations. Also, validity was acceptable. Although further
examination is required, these screening tests seem suitable for use in research
among this type of patient in Japan.
PMID- 10672764
TI - Initial evaluation of the Secondary Trauma Questionnaire.
AB - Many measures exist to evaluate posttraumatic stress disorder (PTSD), but there
are few ways of assessing secondary traumatic stress disorder and these are
limited to specific populations. Secondary traumatic stress disorder involves the
transfer of trauma symptoms from those who have been traumatized to those who
have close and extended contact with trauma victims. Thus, family members of
those who have been traumatized and therapists who treat trauma survivors are
vulnerable to developing secondary traumatic stress disorder. In this initial
evaluation of the newly developed Secondary Trauma Questionnaire, 261 mental
health professionals and 157 college students were evaluated. Analysis indicated
that the questionnaire showed good internal consistency and was significantly
correlated with known measures of trauma. The Secondary Trauma Questionnaire is
presented as a promising way to measure secondary trauma symptoms and further
research using this questionnaire appears to be warranted.
PMID- 10672765
TI - Changes in women's fear of success and fear of appearing incompetent in business.
AB - The primary purpose of this research was to examine whether fear of success and
of appearing incompetent among women have changed recently. Another purpose was
to examine whether such fears differed among women who hold Traditional views and
those who hold Progressive views about the roles of women in the workplace. The
Fear of Success Scale, the Fear of Appearing Incompetent Scale, and the Attitude
Toward Women Scale were completed by 61 male and 52 female graduating seniors.
Significant differences were found between the groups for scores on the Attitude
Toward Women Scale, but none between the sexes for scores on the Fear of Success
Scale or the Fear of Appearing Incompetent Scale. Significant differences were
found, however, on the latter two scales when women were separated into
Traditional and Progressive groups.
PMID- 10672766
TI - Relationship between properties of words and elicitation of skin conductance
response.
AB - We investigated the association of subject-rated imagery, subject-rated
concreteness, subject-rated emotionality, frequency, date of entry into the
language, and word length with emotional imagery as measured by the skin
conductance response elicited by that word. 50 words in a list of 25 word-pairs
were rated by 96 university students; then their skin conductance response of
each word was measured for each word. In each pair, one word was concrete and one
was abstract but with related meaning, e.g., adolescent and adolescence. Stepwise
multiple regression indicated that 30% of variance in the later skin conductance
response was explained by imagery and subject-rated emotionality. Imagery alone
explained 24% of variance.
PMID- 10672767
TI - Accurate knowledge about suicide.
AB - Accurate knowledge about suicide among 150 English students was not associated
with age, sex, personality, or attitudes toward suicide.
PMID- 10672768
TI - Locus of control as a dispositional determinant of men's traditional sex-role
attitudes.
AB - The associations among measures of locus of control and attitudes toward women
who work were assessed using data from the National Longitudinal Survey of Youth
for 1,229 young adult males. Significant positive correlations, ranging from .09
to .14, were found among locus of control and men's negative stereotypes of women
who work, which suggests that males who feel a lack of personal control may
oppose women working outside of the home. The results also indicate that men with
greater personal control may be more accepting of women in nontraditional sex
roles than men with an external locus of control. Negative stereotypes of women
who work and male self-preservation may explain these relationships.
PMID- 10672769
TI - Description of older adults as depicted in magazine advertisements.
AB - Negative attitudes about aging have been widespread and films, television, radio,
and print media may serve as an important source of socialization or reflect the
current views of older adults. This study focused on examination of the frequency
of depictions of older men and women in 765 advertisements appearing in Time and
Newsweek national weekly news magazines, and on an analysis of their roles
suggested in photographs depicting a total of 2,505 persons. These were collected
over a one-year period and coded by three persons. Analysis indicated that older
adults, especially older women, were not only presented infrequently but, when
presented roles, were often passive or dependent as is consistent with social
stereotypes.
PMID- 10672770
TI - Comment on "manic-depressiveness and its correlates".
AB - Data from a sample of 612 college students showed that the Depression subscale of
the Manic-Depressiveness Scale had greater internal reliability than the Mania
subscale. Furthermore, correlates of the total scale score did not appear to
provide as useful information as use of the Depression and Mania subscales
separately.
PMID- 10672771
TI - [Apocalypse 2000: the end of science and the golden age of pseudo-medicine].
PMID- 10672772
TI - [Digestive emergencies of elderly patients].
AB - Evaluation of an elderly patient with acute abdominal conditions presents a
challenge to the physician on account of the general poverty of history and
clinical signs and the poor reliability of diagnostic procedures. The management
of these pathologies are analyzed: cholecystitis, appendicitis, incarcerated
hernia, small bowel obstruction, colonic diverticular disease, intestinal
ischemia and gastroduodenal ulcer. An early elective treatment of chronic
pathologies like gallstones, hernias and intestinal ischemia trends to avoid
complications.
PMID- 10672773
TI - [Autosomal dominant spinocerebellar ataxia].
AB - The autosomal dominant spinocerebellar ataxias (SCA) are a heterogeneous group of
degenerative diseases presenting with ataxic gait, limbs ataxia, dysarthria and
cerebellar oculomotor disturbances. Usually, cerebellar signs are associated with
pyramidal signs, extra-pyramidal signs, spinal signs and signs of peripheral
neuropathy. Neuropathological studies have disclosed an involvement of the
cerebellum and its afferent/efferent pathways, of the brainstem and of the spinal
cord. Distinct entities are now recognized: SCA1, SCA2, SCA3/Machado-Joseph
disease, SCA4, SCA5,SCA6, SCA7 and dentatorubropillidoluysian atrophy (DRPLA). In
most cases, a CAG trinucleotide repeat expansion has been demonstrated by genetic
investigations. Moreover, recent studies have shown that autosomal dominant
spinocerebellar ataxias are characterized by intra-nuclear inclusions containing
polyglutamine in affected cells. These complexes might pl ay a determinant role
in the neurodegenerative process. Cell death could be due to accumulation of a
polyglutamine as a result of trinucleotide repeats.
PMID- 10672774
TI - [Adenopathy and eosinophilia].
AB - The exercise topic is the persistence of adenopathies for many years in a young
marocan boy who also presents with peripheral blood eosinophilia.
PMID- 10672775
TI - [Reboxetine (Edronax)].
AB - Reboxetine is a new antidepressant acting by selective inhibition of
noradrenaline reuptake (NARI) at the synaptic cleft. The efficacy of reboxetine
is similar to other antidepressants such as tricyclic and Selective Serotonin
reuptake inhibitors once (SSRI). A faster onset of action (in a mean of 10 days)
is suggested by preliminary studies. Reboxetine seems also to improve social
adjustment of the treated depressed patients. Due to its selectivity, reboxetine
presents a favourable safety profile. Treatment of depression will certainly
benefit from this new compound. However, some issues need to be clarified such as
the use of reboxetine in combination with other antidepressants.
PMID- 10672776
TI - [The search for medical information on the World Wide Web].
AB - The internet has experienced tremendous growth over the past few years and has
currently many resources in the field of medicine. However, many physicians
remain unaware of how to gain access to this powerful tool. This article briefly
describes the World Wide Web and its potential applications for physicians. The
basics of web search engines and medical directories, as well as the use of
advanced search with boolean operators are explained.
PMID- 10672777
TI - [Ventricular repolarization anomalies in an asymptomatic patient].
PMID- 10672778
TI - [Albert Brachet, the "Standard of Anatomy"].
PMID- 10672779
TI - Exposure to environmental tobacco smoke and the risk of lung cancer: a meta
analysis.
AB - A meta-analysis was carried out to calculate a pooled estimate of relative risk
of lung cancer following exposure to environmental tobacco smoke (ETS) and to
determine whether there was any heterogeneity in the pooled estimates according
to selected characteristics of the studies. A total of 35 case-control and five
cohort studies providing quantitative estimates of the association between lung
cancer and exposure to ETS published between January 1981 and March 1999 were
identified. Using fixed- and random-effects models, we calculated pooled
estimates of relative risk for exposure to ETS from subjects' parents (during
childhood), spouses, and coworkers. As well, we investigated whether the pooled
estimates of relative risk varied by study location, degree of control of
potential confounding variables, proportion of cases confirmed histologically,
proportion of surrogate respondents, nonresponse rates, and year of publication.
The relative risk of lung cancer among non smoking women ever exposed to ETS from
their husbands' smoking was 1.20 (95% confidence interval (CI): 1.12-1.29). The
pooled relative risk was 1.19 (95% CI: 1.10-1.29) for case-control studies and
1.29 (95% CI: 1.04-1.62) for cohort studies. In various subgroup and meta
regression analyses, we found no statistically significant differences by
selected characteristics of the studies. In addition, we found that the risk of
lung cancer increased consistently with increasing levels of exposure. The 11
studies reporting relative risks among male non smokers yielded a pooled relative
risk of 1.48 (95% CI: 1.13-1.92) for ever exposed to ETS, and the relative risk
of lung cancer for ever being exposed to ETS at work was a 1.16 (95% CI: 1.05
1.28). These results are consistent with the hypothesis that exposure to ETS
increases the risk of lung cancer. While there may be alternative explanations to
the data, it is more likely that the observed association is not an artifact and
that ETS causes lung cancer in non smokers.
PMID- 10672780
TI - Prognostic impact of cathepsin B and matrix metalloproteinase-9 in pulmonary
adenocarcinomas by immunohistochemical study.
AB - The expression of Cathepsin B (CB) and matrix metalloproteinase-9 (MMP-9) in
extirpated tissues of adenocarcinomas in non-small cell lung cancer from 90 cases
was investigated immunohistologically, and the correlations between the extent of
the expression and the clinicopathological features were assessed for
investigating the process of tumor metastasis. It is important to reveal the
mechanisms of destruction of the basal membrane and infiltration of tumor cells
at the primary lesion. Sections were obtained from 10%-formalin-fixed and
paraffin-embedded tissues. They were reacted with an anti-human CB polyclonal
antibody or an anti-human MMP-9 polyclonal antibody. Of 90 patients, 58 (64.4%)
and 39 (48.3) cases were found to be positive for CB and MMP-9 expression,
respectively. A significantly higher extent of the CB expression was observed in
the tissues of patients who showed postoperative recurrence of the tumor (P =
0.013). Especially, a similar observation was obtained among early cases of T1N0
(P = 0.023). In contrast, no such tendency was demonstrated in the expression
profile of MMP-9. Furthermore, the enzyme expressions were compared among
different types of metastases. Patients with higher extents of CB expression
tended to show significantly higher rates of hematogenous and intrapulmonary
metastases (P = 0.023 and P = 0.010, respectively). However, there was no
significant correlation between MMP-9 expression and the prognostic factor of the
patients. Therefore, we suggested that evaluation of CB expression in the tumor
tissue might be useful as a postoperative prognostic factor of pulmonary
adenocarcinoma. Especially, early cancer of T1N0 cases showing higher expression
of CB may need postoperative adjuvant chemotherapy.
PMID- 10672781
TI - Immune cell infiltrates and prognosis in primary carcinoma of the lung.
AB - The prognostic significance of immune cell infiltrates in surgically resected
human lung cancer was investigated in 710 patients. Lymphoid infiltrates were
quantified on both standard H&E stained sections and, in a subset of 95 cases,
using immunohistochemistry and antibodies to CD3, CD8, CD57, CD68, CD79a and S100
to identify various immune cell types. Subjective grading (low, moderate, high)
of lymphoid cell infiltrates on H&E sections of tumour and measurement, using
image analysis, of overall level of tumour infiltration by any of the
immunohistochemically labelled specific immune cell types of the stained sections
showed no prognostic significance. However, when a distinction between
peritumoural and intratumoural infiltration by particular cell types was made,
intratumoural infiltration by high levels of CD3+ and S100+ cells was associated
with longer post-operative survival (P = 0.02 and P = 0.045, respectively). In
lung cancer, subjective assessment of tumour lymphoid infiltration and overall
levels of infiltration by particular immune cell types carries no prognostic
significance. Intratumoural infiltration by relatively high numbers of CD3+ T
lymphocytes and Langerhans cells (S100+) is associated with a better patient
outcome.
PMID- 10672782
TI - Phase II trial of induction high-dose chemotherapy followed by surgical resection
and radiation therapy for patients with marginally resectable non-small cell
carcinoma of the lung.
AB - The combination of carboplatin and paclitaxel is an active regimen in non-small
cell lung cancer (NSCLC). Historically, patients with stage III disease have
manifested higher response rates than patients with metastatic disease, and
patients achieving a pathologic complete response to induction chemoradiation
therapy prior to surgery have shown better long-term outcome. Based upon our
pilot data using high-dose carboplatin and paclitaxel, we designed a phase II
trial in patients with marginally resectable stage IIIA NSCLC. Ten patients, with
bulky nodal stage IIIA disease, initially received etoposide (2 g/m2) and
granulocyte colony-stimulating factor (G-CSF) to mobilize peripheral blood stem
cells (PBSC). Two cycles, 28 days apart, of carboplatin (AUC 12 in seven
patients; AUC 16 in three patients) and paclitaxel (250 mg/m2) were administered
with filgrastim (5 microg/kg) and PBSC support. After re-evaluation, patients
underwent a thoracotomy followed by radiotherapy (44-60 Gy) if deemed resectable,
or radiotherapy alone (60 Gy) if not resectable. The median age was 58.5 years
(48-66) with a median ECOG performance status of 0 (0-1). Histology was
adenocarcinoma in seven patients; the remainder had either squamous cell, large
cell or bronchoalveolar carcinoma. Based on CT radiography, the overall response
rate was 40%. Eight of ten patients underwent resection with four right
pneumonectomies, three right upper lobectomies and one wedge resection of the
right upper lobe. Six patients had a complete resection. Of eight patients
resected, four were downstaged by induction therapy, three remained unchanged and
one was found to have more extensive disease. The remaining two patients
developed metastatic disease while receiving chemotherapy. The median dose of
postoperative radiotherapy was 54 Gy (35-66 Gy). Actual median follow-up for all
patients was 89 weeks (25 to 136+). The actuarial median overall survival was 124
weeks (25 to 136+) and time to progression was 57 weeks (17 to 136+). The median
dose of carboplatin delivered expressed as mg/m2 was 779 (615-1540). Neutropenic
fever occurred in two patients during the initial mobilization cycle only. The
median number of units of RBC and/or platelets transfused was 0 (0-2 and 0-6,
respectively). There were no significant non-hematologic toxicities. High-dose
induction chemotherapy with stem cell rescue is feasible and safe with an
acceptable response rate. Thoracotomy, including pneumonectomy and postoperative
radiotherapy, were well tolerated by patients after undergoing high-dose
induction chemotherapy with no apparent increase in peri-operative morbidity. The
pathologic complete response rate was low--one out of ten patients. These results
indicate that dose escalation of induction chemotherapy does not improve response
rates even in this highly selected patient population. Accordingly, the
complexity and potential toxicity of high-dose chemotherapy, as delivered in this
trial as neoadjuvant treatment of non-small cell lung cancer, is not warranted.
PMID- 10672783
TI - Second-line treatment with gemcitabine and vinorelbine in non-small-cell lung
cancer (NSCLC) cisplatin failures: a pilot study.
AB - PURPOSE: This pilot study was designed to evaluate the efficacy and toxicity of
the gemcitabine/vinorelbine combination in non-small-cell lung cancer (NSCLC)
patients who had failed cisplatin-based first-line chemotherapy. PATIENTS AND
METHODS: Eligible patients had refractory or resistant NSCLC, WHO performance
status 0-2, adequate hematologic parameters and normal hepatic, renal and cardiac
function. Gemcitabine (1200 mg/m2) was administered on days 1, 8 and 15;
vinorelbine (25 mg/m2) was administered on days 1 and 8, every 4 weeks until
patients experienced disease progression. RESULTS: From September 1997 to March
1998, 16 patients were enrolled (six: stage IIIB: ten: stage IV). All 16 patients
were assessable for toxicity and evaluated for response. One complete (6.25%)
response and no partial responses were observed. Median survival was 25 weeks
(95% CI 19-30). A median of 3.31 courses per patient was administered, and the
median interval between courses was 28 days. The median delivered dose was 664.85
mg/m2 per week of gemcitabine and 10.71 mg/m2 per week of vinorelbine,
corresponding to a relative dose intensity of 0.73 and 0.85, respectively. Grade
2/3 thrombocytopenia occurred in 13 (24.52%) of 53 courses administered.
Neutropenia Grade 2/3 occurred in 14 courses (26.41%). There were seven (13.20%)
episodes of fever related to the drug administration. Mild asthenia was observed
in six (37.5%) patients. Other toxicities were mild to moderate. CONCLUSION:
These results suggest that this gemcitabine/vinorelbine combination is not an
active salvage regimen in patients with refractory NSCLC. The combination merits
further evaluation with modified regimens.
PMID- 10672784
TI - Primary primitive neuroectodermal tumor of the lung: report of two cases.
AB - Two cases of primitive neuroectodermal tumor of the lung are reported. The first
case is a 41-year-old man with a tumor in the left upper lung, and the second
case is a 30-year-old woman with a tumor in the right lower lung. In both cases,
the tumors originated in the lung but not in the chest wall. No distant
metastasis was detected. In case 1, transcutaneous fine-needle biopsy (TCNB)
revealed small round cell proliferation, although bronchoscopic examination
showed no abnormal findings. Both the expression of Mic2 protein and
t(11;22)(q24;q12) translocation were proved in the tumor cells. The tumor cells
were positive for periodic acid-Schiff (PAS), neuron-specific enolase (NSE), and
vimentin, but negative for Leu7, chromogranin A, and pro-gastrin-releasing
peptide (ProGRP). In case 2, bronchoscopic examination showed only compressive
change in right lower lobe bronchi. TCNB revealed small round tumor cells
expressing Mic2 protein. The tumor cells were negative for leukocyte common
antigen, S100 protein, pankeratin, chromogranin A, and desmin, but weakly
positive for NSE and moderately positive for Ki-67 (MIB1). Both patients were
successfully treated by the combination of surgical resection and chemotherapy,
and are alive with no sign of recurrence for approximately 22 months in case 1
and 16 months in case 2.
PMID- 10672785
TI - A pharmacokinetic model for multiple sites discontinuous gastrointestinal
absorption.
AB - PURPOSE: To build a pharmacokinetic model taking into account a discontinuous
absorption along the gut, from n successive sites, a non-absorbing intestinal
segment being always in between two successive sites. To solve the mathematical
model linked with the pharmacokinetic model to obtain the concentration and
contribution of each site to absorption, area under curve and bioavailability.
METHODS: Whatever the number n of sites, we obtained the Laplace transform of
amounts of drug in each site, then plasma concentration, so that concentration or
AUC were expressed analytically. When only two absorption sites are present,
concentration is obtained from Heaviside's theorem; but for n> or =3, Bromwich's
theorem is necessary, a pole being of the order of more than two. RESULTS:
Simulations performed with data gathered from the literature allow to find, with
n=2 sites, the particular case used for ranitinine and to show the efficacy of
each site. For n=3 sites, real data exhibiting three peaks of various magnitude
were fitted on our model. CONCLUSION: This general discontinuous oral absorption
pharmacokinetic model may be taken as a possible tool to characterize each site
of absorption and to estimate the area under curves or bioavailability.
PMID- 10672786
TI - Two methods for the measurement of voluntary contraction torque in the biceps
brachii muscle.
AB - Appropriate measurement of maximal voluntary contraction force of a single limb
muscle or of a muscle group is important in clinical and research situations. To
measure muscle force, one segment of an isometric measuring brace is fixed to a
support and force is applied to the other. The output of this arrangement is
affected by additional contributions such as pushing or pulling with the whole
body. This paper quantifies the differences between measurements of torque
produced by the biceps brachii with the brace fixed versus those produced when
the elbow joint was isolated by suspending the brace from cables. No
statistically significant differences were found between MVC values observed with
the two methods within subjects. However, a statistically significant difference
in EMG fatigue indices was observed and attributed to a different sharing of
force production among different muscles in the two conditions. We conclude that
different brace arrangements may lead to the same maximal force but to different
rates of myoelectric manifestations of muscle fatigue since the effort may be
shared differently among the muscles of synergic or stabilizing groups.
PMID- 10672787
TI - Ultrasound velocity and attenuation in relation to maximum trabecula stress in
the patella.
AB - The ultrasound velocity and attenuation were examined in 16 sets of human
patellae. The average ultrasound velocity of patella was shown to be greater in
the superior/inferior direction than in the anterior/posterior and medial/lateral
directions. The distribution of bone mineral density (BMD) was also examined. The
BMD of the patella varied with location. BMD values were largest at the superior
and lateral regions and decreased inferiorly and medially. A two-dimensional
finite element analysis was performed on each patella. The maximum von Mises
stress occurred along the cortical shell on the non-articular surface. The
trabecular von Mises stress existed in the posterior region of the patella.
Correlation study showed that patellar BMD was significantly associated with each
of three directional ultrasound velocities. The relationship between BMD and
ultrasound attenuation was not significant. It was also found that the ultrasound
velocity and attenuation were not significantly correlated with the maximum von
Mises stress.
PMID- 10672788
TI - Effect of aneurysmectomy on left ventricular shape and function: case studies.
AB - The three dimensional (3D) conformational changes in three patients with large
anterior aneurysm in the left ventricle (LV) were examined before and two years
after aneurysmectomy by using 3D Cine-computerized tomography (CT). Endocardial
and epicardial tracings of 6-9 short axis images encompassing the entire LV were
used to reconstruct the LV in 3D. Thickness and percent thickening were
calculated using our 3D-volume element approach. A regional wall stress index
(stress/pressure) was calculated from regional curvature and thickness. The
analysis showed that following resection of the aneurysm the end-diastolic volume
was reduced from 257+/-39 to 183+/-39 ml, end-systolic volume from 172+/-39 to
92+/-46 ml and, ejection fraction increased from 34+/-7 to 51+/-13%. The
endocardial aneurysm area decreased from 19.7+/-15.9 to 10.1+/-6.5 cm2, whereas
the normal zone area was minimally reduced from 87.4+/-17.6 to 79.8+/-10.8 cm2.
The percent thickening of the normal zone increased significantly. It is
documented here for the first time by detailed 3D analysis that the resection of
the LV aneurysm reduces the aneurysmal area and LV size and improves the global
and regional function of the remote normal zone. Therefore, the 3D approach can
help to design better surgical technique for this complex operation.
PMID- 10672789
TI - Analysis of volition latency on antisaccadic eye movements.
AB - The antisaccadic paradigm can be applied to test the suppression of reflexive
saccades and the activation of volitional saccades simultaneously. The impaired
frontal cortex has been shown to have difficulty in suppressing reflexive saccade
(prosaccade) to make a successful antisaccade. Degraded antisaccade performance
can also be observed in patients with Parkinson's disease (PD). The studies of PD
based on the prosaccadic and antisaccadic paradigms have shown controversial
findings; the latency between patients and age-matched controls could be either
with or without significant difference. Even with this inconsistency, our
previous study and recent analysis have supported that the latency of both
prosaccade and antisaccade increases significantly for patients with PD. The
objective of this study is to investigate whether prolonged antisaccade latency
is caused by the affected volitional decision process (volition latency) or
simply by the delayed initiation of saccade with direction opposite to the cue,
by measuring prosaccade and antisaccade latency from the intermingled paradigms.
Eleven mildly affected patients with idiopathic PD and eight age-matched normal
subjects were tested in this study. As compared to the age-matched control, the
results showed that prosaccade, antisaccadic, and volition latency of the
patients was significantly elevated (P<0.01). We conclude that antisaccade
performance for the PD patients was degraded for both the volition decision
process and the initiation of saccade with direction opposite to the cue. Also,
volition latency analysis is a more objective method than prosaccade and
antisaccade latency analysis, which can be compared among results obtained from
different analysis methodologies.
PMID- 10672790
TI - A 16-channel SQUID-device for biomagnetic investigations of small objects.
AB - Biomagnetic investigations in basic physiological research using animals require
measurement devices different from commercial biomagnetometers used in human
investigations. Two major problems have to be tackled in the design of such
biomagnetometers. First, the spatial sampling needs to be much higher. Second,
the distance between pick-up coils and the sources needs to be much shorter in
order to compensate the worse signal-to-noise ratio (SNR) due to the smaller pick
up coils. We designed and built a 16-channel biomagnetic measurement system
meeting these design criteria. The pick-up coil diameter of this new
biomagnetometer is 6.7 mm, thus allowing 16 channels on an area of 3.2x3.2 cm2.
The pick-up coils are located 3 mm above the dewar outer bottom, hence the
closest distance to the cortical surface can be a few millimetres. We provide as
an example of first measurements performed with the new biomagnetometer
investigations of epileptic spikes in adult rabbits by simultaneous
magnetoencephalogram (MEG) and electrocorticogram (ECoG) recordings. The high SNR
of the recorded MEG and the simultaneously detected electric potentials allow
investigations of the spatio-temporal pattern of neuronal processes of
epileptiform spikes with signal strengths of about 3.5 pT.
PMID- 10672791
TI - The incidence of radio-frequency impulsive noise within hospital buildings:
initial measurements in the 450 MHz band.
AB - This paper reports on the incidence and level of man-made electrical impulse
noise capable of causing interference to low-power, ASK and FSK radio
biotelemetry links. Measurements were made at two acute hospitals, one in a
residential area of Belfast, Northern Ireland and the other in an industrial part
of Berlin, Germany. Monitoring was effected in the 450 MHz band using a
communications receiver with its AGC line disabled and AM-detector AM output fed
to a PC-based logger. The RF bandwidth was 20 kHz and a rotatable folded-dipole
receiving antenna was used. Seven-day impulse counts were recorded at each
location, for separate RF input thresholds of -100, -110 and -120 dBm and a
common trigger window of 10 micros-10 ms. Histograms depicting the average pulse
count per minute are presented; values range from a maximum of 55x10(3)/min for
120 dBm sensitivity in Berlin, to a minimum of 1.2/min for -100 dBm sensitivity
in Belfast, both with vertical polarisation.
PMID- 10672792
TI - Variation of the spatial position computed by Roentgen Stereophotogrammetric
Analysis (RSA) under non-standard conditions.
AB - Roentgen Stereophotogrammetric Analysis (RSA) has been applied to different kinds
of research in order to obtain important information in the biomechanics field.
Operative requirements change according to the type of investigation and
sometimes practical conditions do not always permit one to respect standard
specifications. The aim of this paper is to verify the reliability of the system
under non-standard conditions, studying the effects of the focus-to-film distance
on the determination of 3D co-ordinates of markers. The application of
statistical analysis, consisting of two and three way ANalysis Of VAriance
(ANOVA), showed that focus-to-film distance is not a significant source of
variation, i.e., the system can correctly compute the marker position inside the
calibrated space under all conditions of magnification. Since we obtained a
fluctuation due to focal distance change of 10(-5) mm (LSD for 95% confidence
level), we can assert that this source causes a variation strictly within the
limits required by clinical investigations. Thus, this study contributes to
improving the flexibility of RSA in clinical applications, making the technical
requirements of the radiographic set-up less constraining.
PMID- 10672793
TI - Calculation of extracellular potentials produced by an inclined muscle fibre at a
rectangular plate electrode.
AB - Generally the anatomy of muscles is rather complex, and the fibres have various
inclination angles within the muscles. We suggest a fast and reliable way to
calculate extracellular potentials produced at a point or rectangular plate
electrode by a muscle fibre of finite length with an arbitrary inclination. A
muscle fibre was considered to be a linear timeshift-invariant system of
potential generation. Then, similar to the fibre without inclination, the
extracellular potential produced by an inclined fibre was represented as the
output signal of the system; it was calculated as the convolution of the input
signal and impulse response. Irrespective of the inclination, the input signal of
the system was the first temporal derivative of the intracellular action
potential. The impulse response of the system differed for the fibres with
inclination. This required a new method of analytical integration over the
rectangular electrode area. The approach provides a chance to simulate and
analyze motor unit potentials or F-, H- or M-responses produced by muscles of
complicated anatomy (circum-pennate or complex pennate type) at electrodes of
actual size and location in normals and patients with neuro-muscular disorders.
PMID- 10672794
TI - Dimensional change in muscle as a control signal for powered upper limb
prostheses: a pilot study.
AB - The vast majority of externally powered prostheses are controlled from the
myoelectric signal, measured at the skin surface using socket-located electrodes.
This signal has been well researched and sophisticated signal processing methods
developed. Nevertheless, the inherent properties of the signal, such as its broad
bandwidth and low voltage amplitude, make its use less than straightforward in
the control of low frequency activity such as powered prosthetic hand movement.
This paper reports on a pilot study of an alternative, a signal derived from
dimensional change in muscle. A new socket-located sensor was designed to measure
dimensional change in muscle, the linearised output of which is termed the
myokinemetric (MK) signal. This was used in a series of tasks aimed at
investigating the potential for its use in upper-limb prosthesis control. Six
amputee subjects were tested, of whom one was a regular user of the myoelectric
hand, one had some experience, and four had little or no previous experience of
controlling devices using their residual limb. Data is presented on the problems
of shift in signal range with time and socket donning and doffing and on the
ability of subjects to control the amplitude of the signal. The results show that
subjects were able to control the magnitude of the MK signal to a significant
degree, with typical errors averaging 0.1-0.3 mm, around 10% of the signal range.
The principal problem encountered was the shift in signal with time and socket
donning and doffing.
PMID- 10672795
TI - Bone donor site. Iliac crest or distal radius?
AB - In a series of 18 patients requiring bone-grafting procedures to the wrist, bone
structure and bone turnover characteristics were compared between samples of bone
harvested from the iliac crest and the distal radius. Histologically and
biologically the iliac crest bone was found to be superior to distal radial bone.
Axial bone was also shown to be more resistant to the ravages of increasing age
and chronic disease. However, in spite of these laboratory findings, clinically,
radial bone is equally successful as graft material. This, in all probability, is
due to the greater porosity of radial bone which allows better compaction, more
accurate filling of defects and easier nourishment of the graft by surrounding
body fluids.
PMID- 10672796
TI - Early active mobilization of primary repairs of the flexor pollicis longus
tendon.
AB - This study reports the treatment of divided flexor pollicis longus (FPL) tendons
from 1989 to 1998. The first 30 patients, in whom the tendon was repaired with a
Kessler suture and simple epitendinous suture and mobilized using early active
motion with only the thumb splinted, achieved 70/73% (White/Buck-Gramcko
assessments respectively), excellent or good results and a rupture rate of 17%.
The next 39 patients underwent the same treatment but in a splint with the thumb
position altered and the fingers also splinted, with 67/72% excellent or good
results and a rupture rate of 15%. The next 49 patients underwent repair with a
Kessler suture and a reinforced epitendinous suture and the same mobilization as
group 2, with 76/80% excellent or good results and a rupture rate of 8%. The
final combination of repair and early active mobilization for primary repair of
FPL tendons compares favourably with previous methods of treatment.
PMID- 10672797
TI - Flexor tendon repair using a stainless steel external splint. Biomechanical study
on human cadaver flexor tendons.
AB - A stainless steel external tendon splint was used in repair of cadaver tendons
and compared with standard tendon repairs with suture. The splint was combined
with a Kessler repair and tested against the Kessler, Becker, and Savage repairs
in fresh human cadaver flexor digitorum profundus tendons. Biomechanical testing
was done on a tensile testing machine, and load-displacement curves were
generated. The repairs using the external tendon splint demonstrated a range of
improvement of 32 to 146% in mean maximal tensile strength and a 20 to 185%
improvement of mean ultimate tensile strength compared with all other repairs.
The external tendon splint is relatively easy to apply to a tendon. The repair is
strengthened and becomes capable of withstanding early active range of motion
exercises. In vivo testing will be needed to assess the potential clinical
usefulness of such a device.
PMID- 10672798
TI - Cytotoxicity of cyanoacrylate adhesives to cultured tendon cells.
AB - The in vitro cytotoxicity of four cyanoacrylate adhesives was tested using
cultures of cells derived from human tendons. All four were found to be
cytotoxic, even at concentrations as low as 1.7%, over the experimental period of
up to 18 weeks. This study shows that such adhesives in their present state may
not be suitable for re-joining cut tendons as their initial and long-term
toxicity may hinder the slow healing process of tendons.
PMID- 10672799
TI - Open and closed arthrodesis of the rheumatoid wrist using a modified (Stanley)
Steinmann pin.
AB - In a series of 21 patients (22 wrists) with rheumatoid arthritis, arthrodesis of
the wrist was done using a modified Steinmann pin (Stanley) either by an open or
closed technique. The open technique, which included fragmenting the carpal bones
(12 cases), was mainly used when additional procedures were needed
simultaneously. The closed technique simply required insertion of the Stanley pin
under fluoroscan control through a small incision over the metacarpal head. Nine
out of 12 wrists treated with the open technique and nine out of ten of those
treated by the closed technique were successfully fused. Complications were few.
A single patient was dissatisfied due to continuing pain. Two out of the four
pins that migrated (both involving the open technique) have been removed.
PMID- 10672800
TI - Comparative results of resection of the distal ulna in rheumatoid arthritis and
post-traumatic conditions.
AB - The purpose of this study was to determine whether the results of resection of
the distal ulna differed depending upon the underlying aetiology of the
condition. Patients with rheumatoid arthritis were compared with patients with
post-traumatic wrist complaints. Fifty resections in 40 patients (eight male, 32
female) were assessed with respect to pain, range of motion, and grip strength.
Of the 23 rheumatoid wrists, 86% were pain-free following surgery; however, only
36% of the patients in the trauma group reported pain relief postoperatively.
Pain relief in post-traumatic patients was more predictable when distal
radioulnar joint arthrosis was identified as the sole cause of wrist pain.
PMID- 10672801
TI - Results of the wafer procedure for ulnar impaction syndrome in the ulnar negative
and neutral wrist.
AB - Thirteen wrists with ulnar neutral or negative variance were treated by open
distal ulna excision (the wafer procedure). The mean follow-up was 25 months
(range, 12-38). At final follow-up grip strength had increased a mean of 14 kgf
and 12 of the 13 patients were very satisfied with the functional outcome and
pain relief. In treatment of the ulnar impaction syndrome, the wafer procedure
provides excellent pain relief and functional restoration particularly in
patients with ulnar neutral or negative wrists in whom triangular fibrocartilage
tears have not yet developed.
PMID- 10672802
TI - Internal fixation of scaphoid fractures with an AO mini-fragment lag screw, using
temporary interoperative AO mini external fixation.
PMID- 10672803
TI - Repair of central slip avulsions using Mitek Micro Arc bone anchors. An in vitro
biomechanical assessment.
AB - In this study we evaluated the pullout strength of the Mitek Micro Arc anchor for
the reconstruction of central slip avulsions at the proximal interphalangeal
joint of the finger. Forty paired fresh frozen cadaver fingers were randomized
into treatment (anchor) and control groups (horizontal mattress repair) and
subjected to tensile loading to failure. The mean (SD) failure loads of the
repairs were: Mitek repair group 22.3 (4.7) N, and control group 24.7 (5.5) N.
There were no statistically significant differences between the failure loads or
the failure mechanisms of the two repairs. The pullout strength of the isolated
anchor-bone complex was evaluated by refitting five anchors with stainless steel
wire. The mean failure load of the isolated anchor was 400% higher than the
tendon-suture-anchor complex, indicating that the weakest link of the system is
not the bone-anchor interface.
PMID- 10672804
TI - Fixation of metacarpal fractures using absorbable hemi-cerclage sutures.
AB - We retrospectively reviewed the use of biodegradable hemi-cerclage sutures in the
treatment of 79 metacarpal fractures in 66 patients. The polyglycolic acid hemi
cerclages achieved sufficient fracture fixation to permit early motion exercises,
but fractures were also immobilized for a mean of 3.7 (range, 1.5-6) weeks
postoperatively, during which time physiotherapy was given. Adequate bony
stability was achieved after a mean of 4.5 (range, 3.5-7) weeks and fracture
redisplacement occurred in only one case.
PMID- 10672805
TI - Internal suture for mallet finger fracture.
AB - An internal suture technique has been used for mallet finger fractures involving
at least 30% of the articular surface. It provides fixation without a button or
transfixion of the fragment. An independent retrospective review was conducted of
ten patients at a mean follow-up of 17 months. Mean visual analogue score (0 to
10) for pain was 2.4 and satisfaction 7.9. Mean active range of motion was 13 to
49 degrees, passive motion was 2 to 56 degrees, pinch strength of effected finger
to thumb was 3.8 kgf (81% of the opposite finger), grip strength 37.9 kgf (95% of
the opposite hand). All fractures united and there were no neuromas.
Complications included two nail deformities, a superficial infection and a pin
track infection. One patient with a crush injury continued to have pain despite
an arthrodesis.
PMID- 10672806
TI - Nonunion following subcapital (neck) fractures of the proximal phalanx of the
thumb in children.
AB - Six cases of nonunion of subcapital (neck) fractures of the proximal phalanx of
the thumb in children were seen over a period of 5 years. Ages at the time of
injury ranged between 2 and 3 years. Entrapment of the thumb in a closing door
was the mechanism of injury in all cases. All fractures were closed and were
significantly displaced. Immediate management was by closed reduction and
splinting in four cases, closed reduction and K-wire fixation in one case and no
treatment in one case, which was later treated by delayed open reduction and K
wire fixation. Only two of the six ununited fractures were eventually treated
with bone grafts and both fractures united resulting in a stable thumb but with a
limited range of flexion of the interphalangeal joint. Factors that may increase
the risk of nonunion of these fractures in children are discussed.
PMID- 10672807
TI - Simultaneous fracture-dislocations of the distal and proximal interphalangeal
joints.
AB - Sixteen cases of simultaneous fracture-dislocations of both the distal
interphalangeal (DIP) and proximal interphalangeal (PIP) joints in the same
finger that were treated during the past 10 years were classified into three
types: the swan-neck injury (dorsal fragment of the base of the distal phalanx at
the DIP joint and palmar fragment of the base of the middle phalanx at the PIP
joint); the double-hyperextension injury (palmar fragments at the DIP and PIP
joints); and the straight-finger injury (with dorsal and palmar bone fragments at
the DIP joint). The results of treatment were more satisfactory in PIP joints
than in DIP joints.
PMID- 10672808
TI - The use of silicone tubing in the late repair of the median and ulnar nerves in
the forearm.
AB - A silicone tube segment was used for repairing the median and ulnar nerves in the
forearm. This study includes 26 patients (20 male and six female), with a mean
age of 23 years (range, 18-26). Injuries were caused by saw, knife and glass
accidents, the latter being most frequent. The mean interval between the injury
and repair was 101 days. Fourteen patients had median nerve injuries, eight had
ulnar nerve injuries and four had both median and ulnar nerve injuries. The
technique was effective in the repair of peripheral nerve injuries with gaps of
up to 3 cm, with better results in the ulnar nerves than in the median nerves.
PMID- 10672809
TI - The influence of delay and the effect of fibrin sealant on the cut surface of the
peripheral nerve. An experimental study in the rat.
AB - Thirty-two sciatic nerves in 16 rats were divided to investigate the effect of
delay in fixation and the use of fibrin sealant at the site of the division on
the nerve end. Specimens were assessed by morphological and morphometric criteria
using scanning electron microscopy and longitudinal sections. All specimens
showed a protruded nerve end. Wrapping the nerve with fibrin sealant before
division and immediate fixation of the specimen resulted in less protrusion.
PMID- 10672810
TI - Psychological aspects of toe to hand transfer in children. Comparison of views of
children and their parents.
AB - Thirty-seven children with congenital (n = 32) or post-traumatic (n = 5) hand
anomalies underwent unilateral or bilateral toe transfers. All had undergone
preoperative counselling. After rehabilitation and more than 1 year after
surgery, the children and their parents were reviewed by a clinical psychologist
to assess the psychosocial outcome of the surgery. A high level of satisfaction
was reported with regard to the surgery, in terms of function, cosmesis, donor
site, psychosocial wellbeing and the reactions of others. This was true
regardless of the gender of the child. However, there was a tendency for the
children to be more positive in their responses than their parents.
PMID- 10672811
TI - 4.5 year follow-up after surgical correction of upper extremity deformities in
spastic cerebral palsy.
AB - Reconstructive surgery was carried out on 27 upper extremities in 24 children
with deformities due to spastic cerebral palsy. Functional evaluation of the
affected extremities was made preoperatively, at 6 months and at a mean of 4.5
years postoperatively using a score added to the assessment system described by
the Committee on Spastic Hand Evaluation. According to the score, dysfunction of
the arm was significantly reduced 6 months after the reconstructive surgery and
the improvements remained essentially unchanged at the later follow-up. The
addition of a score to the original assessment system facilitated the overall
assessment of postoperative results.
PMID- 10672812
TI - Optimal position for the one-bone forearm. An analysis using a hinged brace in
normal subjects.
AB - The purpose of the present study was to determine whether there is an optimal
position for fixation of the one-bone forearm. Eight normal individuals were
fitted with a hinged brace which fixed the position of pronation and supination
and underwent functional hand testing using the tests of Jebsen et al. Our
results indicate that a one-bone forearm in a position of 30 degrees of pronation
will provide the best function for writing and working with small objects using
the dominant arm.
PMID- 10672813
TI - The role of Mepitel silicone net dressings in the management of fingertip
injuries in children.
AB - Forty-five children with isolated fingertip injuries were randomized for
treatment with either Mepitel silicone net dressings or paraffin gauze dressings.
Over a 4 week period, the objective adherence of the dressing, and the perceived
level of stress caused to the child by the dressing change were scored by linear
analogue scales. The wounds were also assessed for the progress of healing and
presence of infection. Twenty children received Mepitel dressings and 25 had
paraffin gauze dressings. There was no difference in duration of healing or
complication rates between the two groups. Statistically lower scores were seen
for the Mepitel group for the first 3 weeks in both adherence and stress scores.
These results suggest that silicone net dressings may be a less adherent and less
painful method of dressing fingertip injuries in children.
PMID- 10672815
TI - Congenital aneurysm of the ulnar artery in the palm.
AB - An aneurysm of the palmar ulnar artery is rare and usually follows penetrating or
blunt trauma to the hypothenar eminence. We report a case in which there was no
history of trauma and the aneurysm may have been of congenital origin.
PMID- 10672814
TI - Hypothenar hammer syndrome. Retrospective study of nine cases.
AB - The hypothenar hammer syndrome is an uncommon lesion of the ulnar artery caused
by repetitive trauma to the ulnar portion of the hand. It characteristically
occurs in the dominant hand of middle-aged craftsmen, but also in athletes
practising various types of sports. We present a retrospective study of nine
patients between 1988 and 1999. The follow-up ranged from 1 to 10 years. We
recommend surgical treatment, by resection of the involved arterial segment and
revascularization either by direct anastomosis or by means of a venous
interpositional graft.
PMID- 10672816
TI - Sympathetic block significantly improves reperfusion in skeletal muscle following
prolonged use of tourniquet.
AB - The effects of guanethidine sympathetic nerve blocks on reperfusion of skeletal
muscle was studied in rats. After 3 hours of ischaemia reperfusion was
significantly better in animals that had received guanethidine.
PMID- 10672817
TI - Delayed sequential ruptures of the index and thumb flexor tendons due to an
occult scaphoid nonunion.
AB - A case of sequential spontaneous loss of flexion in the thumb and index finger
over a 10 year period is reported. Previously unrecognized carpal collapse as a
consequence of a longstanding scaphoid nonunion was identified as the cause.
Fusion of the interphalangeal joint of the thumb and suture of the index
profundus tendon to the middle profundus tendon resulted in a good outcome.
PMID- 10672818
TI - Proximal row transcarpal fracture from a punching injury.
AB - We describe an unusual case of a 31-year-old woman who injured the right dominant
wrist when she punched an assailant's shoulder. She described a mechanism of
direct compression, with the wrist in hyperextension, radial deviation and the
forearm in pronation. She sustained an oblique transverse fracture of the
proximal pole of the scaphoid and a coronal plane fracture of the lunate and the
triquetrum. This unusual proximal row transcarpal fracture is in conflict with
the Mayfield sequence and was caused by a low velocity injury.
PMID- 10672819
TI - Periosteal chondroma of the distal radius.
AB - We report a case of periosteal chondroma in an unusual location at the distal end
of the radius.
PMID- 10672820
TI - Unusual complication of ligation of rudimentary ulnar digit.
AB - We report a case of rudimentary ulnar polydactyly of the hand of a 7-year-old
female child. Histological examination revealed a central traumatic neuroma which
branched into five digit-like projections covered with hyperkeratotic epidermis.
We think this was a result of suture ligation during the postnatal period.
PMID- 10672821
TI - Dupuytren's disease in Marfan's syndrome.
AB - We report a case of histologically confirmed Dupuytren's disease of the hand in a
young man with Marfan's syndrome.
PMID- 10672822
TI - Procedures on the distal end of the ulna are given the name of the surgeon or
surgeons who described them.
PMID- 10672824
TI - The Mantero technique is inappropriate because of a risk of infection due to
external material and burying it can overcome that problem
PMID- 10672823
TI - The Mantero flexor tendon repair in zone 1.
PMID- 10672825
TI - An aid to digit replantation: a new use for the Harris silicone tile.
PMID- 10672826
TI - Recurrent osteoblastoma of the hamate bone.
PMID- 10672827
TI - Classical Barrett esophagus contrasted with Barrett-type epithelium at normal
appearing esophagogastric junction. Central Finland Endoscopy Study Group.
AB - BACKGROUND: Incomplete intestinal metaplasia or specialized columnar epithelium
(SCE) is the histologic hallmark of Barrett esophagus (BE), but it may also occur
at a normal-appearing gastroesophageal junction without BE. We studied whether
differences occur between BE patients and those with SCE at the squamocolumnar
junction but without BE (abbreviated JSCE), in terms of endoscopic and histologic
signs of gastroesophageal reflux disease (GERD) and Helicobacter pylori
gastritis. METHODS: A total of 1059 consecutive patients referred for endoscopy
in one hospital district in Finland were enrolled in the study. Biopsy specimens
(at least two from each site) were obtained from the gastric antrum and the
corpus of the stomach and from the esophagogastric junction and distal esophagus.
RESULTS: Classical BE was detected in 25 (2%) and JSCE in 99 (9%) patients.
Dysplasia in the metaplastic mucosa was observed in six BE patients but in none
of the JSCE patients (P < 0.001). In multivariate analysis the independent risk
factors for BE were endoscopic erosive esophagitis (odds ratio (OR), 6.08; 95%
confidence interval (CI), 2.50-14.82), male sex (OR, 3.02; 95% CI, 1.20-7.65),
and age (OR, 1.02 per year; 95% CI, 1.00-1.06). The independent risk factors for
JSCE were endoscopic erosive esophagitis (OR, 1.88; 95% CI, 1.08-3.29) and age
(OR, 1.03; 95% CI, 1.02-1.05) but not H. pylori infection (OR, 1.57; 95% CI, 0.83
2.97) or chronic gastritis (OR, 0.88; 95% CI, 0.44-1.75). In univariate analysis,
however, JSCE was associated with antral-predominant atrophic gastritis (77% H.
pylori-positive). Unlike in JSCE patients, male sex strongly predominated among
BE patients (P = 0.01). The mean ages of BE and JSCE patients did not differ.
CONCLUSIONS: Both BE and JSCE without BE increase in prevalence with age, and
both associate with endoscopic erosive esophagitis but not with H. pylori
gastritis. However, because of the marked sex disparity, JSCE cannot be a direct
precursor of BE, and some factors other than GERD alone also play a role in the
pathogenesis of BE. Compared with BE, dysplasia is a rare finding in JSCE, and
endoscopic surveillance with biopsy specimens from JSCE patients without
dysplasia is not recommended.
PMID- 10672828
TI - Screening for oesophageal adenocarcinoma: an evaluation of a surveillance program
for columnar metaplasia of the oesophagus.
AB - BACKGROUND: Screening patients with columnar metaplasia of the oesophagus for
adenocarcinoma is controversial owing to the low cancer incidence and diverging
opinions as to whether screening improves the prognosis of these patients. Our
aim was to evaluate a screening program for adenocarcinoma in patients with
columnar metaplasia in the oesophagus, with focus on cancer incidence and costs.
METHODS: One hundred and ninety-nine patients with columnar metaplasia of the
oesophagus were identified through an endoscopy database, and the original
patient records were reviewed. RESULTS: The patients were followed up for 797
years in total and during this time were subjected to 1071 upper gastrointestinal
endoscopies. During the screening period 5 patients presented with
adenocarcinoma; thus the cancer-incidence was 1 in 159 patient-years. The cost of
detecting one cancer was 294,950 SEK (US$ 37,815). However, only four of the five
patients were suitable for oesophagectomy, and of these, one patient turned out
to have an advanced cancer. All patients developing cancer had columnar
metaplasia of the oesophagus longer than 3 cm and specialized columnar epithelium
(intestinal metaplasia/Barrett oesophagus). CONCLUSIONS: Low cancer incidence,
high costs, and the doubtful prognosis for the patients with identified cancer
question the benefits and cost-effectiveness of cancer screening among patients
with columnar metaplasia in the oesophagus.
PMID- 10672829
TI - The esophageal Z-line appearance correlates to the prevalence of intestinal
metaplasia.
AB - BACKGROUND: Intestinal metaplasia at the gastroesophageal junction is associated
with Barrett esophagus, gastric cardiac cancer, and gastritis. The aim of this
study was to determine the prevalence of intestinal metaplasia among patients
with symptoms suggestive of gastroesophageal reflux disease (GERD) and to study
clinical, endoscopic, and histologic associations with intestinal metaplasia at
the squamocolumnar junction. METHODS: One hundred and eighty-six patients with
symptoms indicating gastroesophageal reflux were included in the study. A new
classification of the Z-line appearance was used. RESULTS: The Z-line appearance
was found to correlate with the prevalence of intestinal metaplasia at the
squamocolumnar junction (P = 0.0001). Intestinal metaplasia at the squamocolumnar
junction was found in 15.0% of the patients. There was a statistically
significant association between intestinal metaplasia at the squamocolumnar
junction and tongues of columnar epithelium at the Z-line (P = 0.020), intestinal
metaplasia in the cardia (P = 0.020), positive CLO test (P = 0.026), smoking (P =
0.041), and age (P = 0.050). There was no association with endoscopic or
histologic signs of esophagitis or with the severity or duration of GERD
symptoms. CONCLUSION: Intestinal metaplasia at the squamocolumnar junction
correlates with the Z-line appearance, which would justify a new classification.
PMID- 10672830
TI - Expression of hepatocyte growth factor and c-met receptor in gastric mucosa
during gastric ulcer healing.
AB - BACKGROUND: Recent studies have shown that hepatocyte growth factor (HGF) has a
mitogenic and motogenic activity for gastric mucosal cells. The aim of this study
is to ascertain the clinical significance of the expression of HGF and its
receptor (c-met) during the course of gastric ulcer healing. METHODS: Ten
patients who underwent endoscopic mucosal resection (EMR) and developed acute
gastric ulcer and 20 patients with peptic ulcer of the stomach were enrolled in
this study. Tissue samples were serially obtained from both the edge of the ulcer
and its neighboring mucosa 0, 2, and 8 weeks after EMR or diagnosis. Gene
expression of HGF, c-met, c-myc, and proliferating cell nuclear antigen (PCNA)
was semiquantitatively examined by reverse transcription polymerase chain
reaction (RT-PCR) using beta-actin as an internal control. In addition,
expression of HGF and c-met mRNA with regard to the presence or absence of
Helicobacter pylori infection was studied. RESULTS: In patients after EMR HGF, c
met, c-myc, and PCNA mRNA in the ulcer lesion at 0 week was at the peak of its
expression and then decreased with time (P < 0.01, P < 0.05, P < 0.05, and P <
0.05, respectively). In patients who underwent EMR the intensity of HGF mRNA was
correlated with that of c-met, c-myc, and PCNA mRNA (P < 0.0001, P = 0.0095, and
P = 0.0009, respectively) and that of c-met mRNA was correlated with that of c
myc and PCNA mRNA (P = 0.012 and P < 0.0001, respectively). In patients with
peptic ulcer, expression of HGF mRNA decreased with time (0 week versus 8 weeks,
P < 0.05; 0 week versus 8 weeks, P < 0.01). c-Met expression was lower at 8 weeks
than at 0 week (P < 0.05). The intensity of c-met mRNA was correlated with that
of PCNA mRNA (P < 0.0001). H. pyiori-infected mucosa had a higher level of HGF
mRNA than non-infected mucosa. CONCLUSION: The present study suggests that HGF is
one of the growth factors acting together during healing of gastric ulcer.
PMID- 10672831
TI - Alpha1-antitrypsin deficiency may be a risk factor for duodenal ulcer in patients
with Helicobacter pylori infection.
AB - BACKGROUND: Most individuals with Helicobacter pylori infection in Western
countries have no evidence of peptic ulcer disease (PUD). We therefore assessed
the PiZ deficiency variant of the major plasma protease inhibitor alpha1
antitrypsin (alpha1AT) as a risk factor for PUD in H. pylori-infected
individuals. METHODS: The cohort comprised 100 patients with endoscopically or
surgically proven PUD (30 patients with duodenal ulcer (DU) and 70 patients with
gastric ulcer (GU)) and 162 age- and sex-matched controls with PUD-negative
endoscopic findings and no history of PUD. Plasma samples were screened for
alpha1AT deficiency (PiZ) with an enzyme-linked immunosorbent assay (ELISA) and
phenotyped by isoelectric focusing. H. pylori infection was evaluated with an IgG
ELISA technique. RESULTS: Among the 262 patients 17 (6.5%) were positive for the
PiZ alpha1AT deficiency, a frequency of the same magnitude as in the Swedish
general population (4.7%). Of the PiZ carriers 76% (13 of 17) had H. pylori
antibodies compared with 61% (151 of 245) of the non-PiZ carriers (NS). The
prevalence of DU tended to be higher in H. pylori-positive PiZ carriers than in
non-PiZ carriers (15.4%, 4 of 26 versus 0 of 4). Furthermore, among patients with
DU a high PiZ allele frequency (13.3%, 4 of 30) was found compared with the
general population (4.7%) (odds ratio (OR), 3.2; 95% confidence interval (CI),
1.09-8.94; P = 0.02). All DU patients carrying the PiZ allele were positive for
H. pylori. In addition, four of five PiZ carriers with H. pylori infection and
PUD had DU. CONCLUSIONS: The PiZ allele may be a contributing factor in the
development of DU in H. pylori-positive individuals.
PMID- 10672832
TI - Evaluation of the clinical relevance of the iceA1 gene in patients with
Helicobacter pylori infection in Japan.
AB - BACKGROUND: A novel Helicobacter pylori gene, iceA, has two allelic variants, and
the iceA1 strain is associated with peptic ulcer disease. The aims of this study
were to evaluate whether the possession of iceA1 gene is associated with gastric
cancer or the severity of gastritis. METHODS: Ninety-seven subjects (46 patients
with early gastric cancer and 51 control subjects) infected with H. pylori were
studied. DNA was extracted from isolated H. pylori strains, and the presence of
the iceA1 gene was examined by polymerase chain reaction. The features of
gastritis were graded in accordance with the updated Sydney System, using gastric
biopsy specimens. RESULTS: iceA1 was found in 61% of patients with gastric cancer
and 53% of control subjects (NS). The grade of gastritis in iceA1-positive and
negative gastric mucosa was compared. Higher polymorphonuclear cell infiltration
was observed in iceA1-positive subjects (P < 0.05). However, no significant
difference was observed in the grades of mononuclear cell infiltration, glandular
atrophy, and H. pylori density. CONCLUSIONS: Our results suggest that the iceA1
gene is not associated with the development of gastric cancer in Japan, whereas
the iceA1-positive strain may induce more enhanced active gastric inflammation in
cagA-positive and vacA s1/m1 strains.
PMID- 10672833
TI - Apoptosis of human gastric epithelial cells via caspase-3 activation in response
to Helicobacter pylori infection: possible involvement of neutrophils through
tumor necrosis factor alpha and soluble Fas ligands.
AB - BACKGROUND: Infection with Helicobacter pylori activates a proinflammatory gene
program in human gastric epithelial cells and neutrophils and is associated with
significant epithelial cell damage, including an increased level of apoptosis. We
evaluated whether immune mediators produced by neutrophils could modulate gastric
epithelial cell apoptosis in response to H. pylori infection. METHODS: After
gastric epithelial cells were infected with H. pylori in the presence of immune
mediators, including tumor necrosis factor alpha (TNF-alpha) and Fas ligand
(FasL), apoptosis and caspase-3 activity were assessed. The neutrophils were
obtained from healthy volunteers, and Western blot for FasL and quantitative
reverse transcription polymerase chain reaction for TNF-alpha transcripts were
performed. Fas expression in gastric epithelial cells was explored by flow
cytometric analysis. RESULTS: Activation of caspase-3 was first apparent 12 h
after bacterial infection, and the phenotypic expression of apoptosis was first
apparent 18 h after bacterial infection. The extent of apoptosis was similar in
cases of cagA+ cytotoxin+, cagA+ cytotoxin-, cagA- cytotoxin- H. pylori-infected
gastric epithelial cells. Approximately 20% of the Hs746T cells expressed Fas
within 24 h of H. pylori infection. The soluble FasL was upregulated in
neutrophils after treatment with H. pylori-soluble proteins for 24 and 48 h. The
addition of TNF-alpha and the soluble form of FasL, produced by neutrophils,
significantly increased H. pylori-infected cell apoptosis and caspase-3
activation. However, the combination of these two immune mediators showed only an
additive increase. CONCLUSION: These results suggest that H. pylori-induced
gastric epithelial cell apoptosis and caspase-3 activation can be modulated by
the immune response of neutrophils.
PMID- 10672834
TI - Usefulness of a novel enzyme immunoassay for the detection of Helicobacter pylori
in feces.
AB - BACKGROUND: In this study we assessed the reliability of a newly developed enzyme
immunoassay (HpSA) kit for detecting Helicobacter pylori antigen in stool.
METHODS: This study included 309 patients, 147 of whom were defined as positive
and 162 as negative by the 13C-urea breath test, rapid urease test, and
pathologic findings. From these patients fresh stool specimens were collected for
HpSA. RESULTS: When 0.100 was adopted as the cut-off value, in accordance with
the manufacturer's recommendations, the sensitivity, specificity, and accuracy of
the HpSA were 98.0%, 87.0%, and 92.2%, respectively. However, these values were
much improved when a cut-off value of 0.300 was adopted, which was obtained with
our receiver-operator characteristics curve; with this value the sensitivity,
specificity, and accuracy of HpSA were 93.9%, 95.7%, and 94.8%, respectively.
CONCLUSION: These results indicate that HpSA is a highly reliable diagnostic
method for H. pylori infection and is useful in confirming eradication.
PMID- 10672835
TI - Screening of patients with acute infectious diarrhoea: evaluation of clinical
features, faecal microscopy, and faecal occult blood testing.
AB - BACKGROUND: For optimal management of acute infectious diarrhoeal diseases, it is
necessary to utilize a screening process to distinguish between invasive and non
invasive diarrhoeas. The aim of this study was to compare the diagnostic
utilities of clinical features, faecal microscopy (FM), and faecal occult blood
testing (FOBT) in distinguishing invasive diarrhoeas from non-invasive ones.
METHODS: A total of 1008 patients with acute diarrhoea were evaluated. Rectal
swabs were cultured for Salmonella, Shigella, and Vibrio species; rectal swabs
from 109 of these patients were also examined for Campylobacter, enterotoxigenic
Escherichia coli, and rotavirus species. Isolation of faecal enteropathogens
served as the gold standard. FOBT was performed with a commercial modified guaiac
test. Specificity, sensitivity, positive predictive value (PPV), negative
predictive value (NPV), accuracy, and likelihood ratio were compared. RESULTS:
Among the 1008 patients 402 with a single identified enteropathogen were
available for analysis. Invasive and non-invasive enteropathogens were isolated
from 262 (65.2%) and 140 (34.8%) cases, respectively. The presence of visible
blood in faeces was almost a pathognomonic sign of invasive diarrhoea but had
poor sensitivity. Clinical features were useful but inadequate in differentiating
patients with non-bloody diarrhoea (74% of patients) into invasive and non
invasive categories. The sensitivities, specificities, PPVs, and NPVs of FM and
FOBT were 75%, 77%, 58%, 88%, and 85%, 68%, 53%, and 91%, respectively.
CONCLUSION: The presence of visible blood in faeces is a highly specific clinical
feature of invasive diarrhoea but suffers from low sensitivity. In non-bloody
diarrhoea FOBT is a valuable screening test and is comparable to FM, particularly
when interpreted in the clinical context.
PMID- 10672836
TI - No polymorphism in the tissue transglutaminase gene detected in coeliac disease
patients.
AB - BACKGROUND: The autoantigen for the anti-endomysial antibody (AEA) found in
coeliac disease has recently been reported to be the enzyme tissue
transglutaminase (tTG). Polymorphisms in the gene for tTG would result in
different enzymic isoforms being expressed. Certain isoforms may interact with
gliadin to create antigenic neoepitopes, which could then generate an immune
response in genetically predisposed individuals possessing major
histocompatibility complex (MHC) class II DQ2. METHODS: We have sequenced the
coding region of tTG in coeliac patients and normal controls. Total RNA was
extracted from mucosal biopsies from eight AEA-positive histologically proven
coeliac disease patients and four control patients with a histologically normal
duodenum and a negative AEA. The 2-kb coding region of tTG was amplified in
overlapping fragments by reverse transcription polymerase chain reaction (PCR),
using five sets of PCR primers. Each overlapping PCR fragment was sequenced using
the fmol DNA sequencing system. RESULTS: tTG transcripts were detected in all
samples. There was no difference in the coding sequence of tTG between the four
control and eight coeliac patients, even though we observed differences in
sequence between our study and the original published sequence. These differences
have also been reported in sequences published subsequent to the original
description. CONCLUSIONS: Polymorphisms in the tTG gene have not been observed in
coeliac disease patients and therefore cannot explain the creation of
neoepitopes.
PMID- 10672837
TI - Relationship between intestinal permeability and calprotectin concentration in
gut lavage fluid.
AB - BACKGROUND: Calprotectin is released from neutrophils and monocytes, and
increased calprotectin levels in stool may serve as a marker of intestinal
inflammation. Intestinal permeability is increased in inflammatory bowel
diseases, especially in Crohn disease. We studied the relationship between
intestinal permeability and calprotectin concentration in intestinal lavage fluid
in patients with known or suspected inflammatory bowel disease (IBD). METHODS:
Thirty-eight patients were examined; 17 had Crohn disease; 3, ulcerative colitis;
and 18, irritable bowel syndrome. Intestinal lavage was performed by means of a
nasojejunal tube positioned by gastroduodenoscopy. By means of a peristaltic pump
2 l isotonic polyethylene glycol solution (MW, 3350) containing 50 microCi 51Cr
labelled ethylenediaminetetraacetic acid (EDTA) were administered through the
tube over a period of 40 min. The first clear fluid passed per rectum was
collected and analysed for calprotectin levels with an enzyme-linked
immunosorbent assay method. Urine was collected for 5 h and analysed for gamma
radioactivity. 51Cr-EDTA excretion in urine was expressed as percentage of dose
administered (that is, intestinal permeability). RESULTS: Both intestinal
permeability and calprotectin concentration were significantly higher in patients
with IBD than in patients with functional conditions. In Crohn disease the values
depended on disease activity but not on whether the disease was located in the
small or in the large bowel. There was a highly significant correlation between
calprotectin concentration in gut lavage fluid and intestinal permeability
(r=0.79, P<0.0001). CONCLUSION: The significant correlation between calprotectin
concentration in gut lavage fluid and intestinal permeability supports the view
that increased intestinal permeability in IBD might, at least in part, be a
consequence of increased transepithelial migration of neutrophils.
PMID- 10672838
TI - Abdominal symptoms: do they predict gallstones? A systematic review.
AB - BACKGROUND: Our objective was to evaluate the diagnostic accuracy of abdominal
symptoms in gallstones in studies using ultrasonography or oral cholecystography
as the reference standard and to assess the extent to which variability in
diagnostic accuracy is explained by patient selection and other characteristics
of study design. METHODS: A Medline search (1966-1998) was conducted in
combination with reference checking for further relevant publications. Two
independent assessors selected controlled studies that included patients > or =18
years of age. Articles were excluded if sensitivity and specificity could not be
extracted or the included patients were at extraordinary risk for gallstones.
Seven abdominal symptoms were evaluated. Modification of the diagnostic accuracy
by clinical setting, extent of the disease, blinding, age, and sex was analysed
by using logistic regression. RESULTS: A total of 24 publications were included.
The symptoms 'biliary colic', 'radiating pain', and 'analgesics used' were
consistently related to gallstones. The setting of the study had a significant
effect on the diagnostic accuracy of these symptoms. The unadjusted, pooled
diagnostic odds ratios, however, were low (2.6 (95% confidence interval, 2.4
2.9), 2.8 (2.2-3.7), and 2 (1.6-2.5), respectively). The diagnostic odds ratio of
biliary colic increased with the extent of gallstone disease (13.3 (4.2-42).
CONCLUSIONS: Although biliary colic was specific for gallstones, 80% of the
referred patients with gallstones presented with other abdominal symptoms. There
is no current evidence that justifies the use of single abdominal symptoms, other
than biliary colic, in the diagnosis of symptomatic gallstones. Further research
should focus on the prognosis of patients with non-specific abdominal symptoms
and gallstones.
PMID- 10672839
TI - Preoperative diagnosis of bile duct strictures--comparison of intraductal
ultrasonography with conventional endosonography.
AB - BACKGROUND: The accuracy of intraductal ultrasonography (IDUS) and endoscopic
ultrasonography (EUS) were compared in diagnosing biliary obstruction and in
predicting surgical resectability. METHODS: Fifty-six patients with biliary
obstruction were investigated preoperatively with both conventional EUS and IDUS.
The ultrasonographic miniprobe was inserted into the bile duct system through the
working channel of the duodenoscope during endoscopic retrograde
cholangiopancreatography (ERCP). Conventional endosonography was performed with
echoendoscopes in a standard technique. Images of endoluminal ultrasonography
were prospectively reviewed and compared with intraoperative findings and
resection specimen analyses. RESULTS: IDUS exceeded EUS in terms of accuracy
(IDUS, 89.1%; EUS, 75.6%; P < 0.002), sensitivity (IDUS, 91.1%; EUS, 75.7%; P <
0.002), specificity (IDUS, 80%; EUS, 75%; NS), and T-staging (IDUS, 77.7%; EUS,
54.1%; P < 0.001). In bile duct carcinomas the accuracy rate for lymph node
staging using IDUS (60%) is comparable with that using EUS (62.5%). In pancreatic
carcinomas, however, lymph node staging using IDUS (13.3%) is significantly (P <
0.002) inferior to EUS (69.2%). Endoluminal ultrasonography may predict the
potential resectability of bile duct tumors (IDUS, 81.8%; EUS, 75.6%; P < 0.002).
CONCLUSIONS: IDUS proved to be accurate in preoperative diagnosing and T-staging
of malignant biliary strictures, whereas it is not suitable for lymph node
staging. IDUS using miniprobes during ERCP exceeds conventional EUS in terms of
depiction of bile duct obstruction, diagnostic accuracy, and sensitivity and in
the prediction of surgical tumor resectability. Additionally, different to EUS,
IDUS can conveniently be performed during ERCP in one and the same session.
PMID- 10672840
TI - Diet restriction increases ubiquinone contents and inhibits progression of
hepatocellular carcinoma in the rat.
AB - BACKGROUND: The aim of the present study was to evaluate the effect of a moderate
diet restriction on the progression of preneoplastic foci into hepatocellular
carcinomas (HCCs) and whether such an effect was related to altered cell
proliferation, apoptosis, and/or tumour contents of lipid-soluble antioxidants.
METHODS: Male Wistar rats were exposed to diethylnitrosamine as initiator and 2
acetylaminofluorene plus partial hepatectomy as promoter. Six weeks after
initiation the animals were given a diet restricted to 75%-80% of that given to
controls until being killed 45 weeks later. Macroscopic liver tumours were
histologically classified. In hepatocellular carcinomas the numbers of S-phase
(labelling index) and DNA-fragmented (apoptotic index) nuclei were calculated
immunohistochemically, and the tumour contents of alpha-tocopherol and ubiquinone
were determined. RESULTS: The number of animals with HCC and the number of HCCs
per animal were significantly reduced in restricted-diet animals compared with
controls. In HCCs the contents of ubiquinone-9 and -10 were significantly
increased, labelling indices were enhanced 3-fold, and apoptotic indices 12-fold
as a response to food restriction. Neither the size nor the differentiation of
HCCs was altered by food restriction. The numbers and areas of preneoplastic foci
were similar in restricted-diet animals compared with those of controls.
CONCLUSION: Moderate, long-term food restriction inhibits the progression of
preneoplastic liver foci into HCC. Possible mechanisms of this inhibition are a
shift in the balance between apoptosis and cell division towards cell death and
an adaptive response to oxidative stress by increased tumour contents of
ubiquinones.
PMID- 10672841
TI - C-met protooncogene expression and its regulation by cytokines in the
regenerating pancreas and in pancreatic cancer cells.
AB - BACKGROUND: Activation of the receptor c-met stimulates motility, mitosis,
morphogenesis, processes involved in organ regeneration, or progression of
malignancies. In the present study we investigated the expression of c-met
protein in the regenerating pancreas and characterized the influence of cytokines
on c-met expression. METHODS: Acute pancreatitis was induced in rats by cerulein
injection. Rat acini and rat and human pancreatic cancer cells were stimulated
with interleukin-1alpha (IL-1alpha), IL-6, tumor necrosis factor-alpha (TNF
alpha) or transforming growth factor-beta1 (TGF-beta1). C-met expression was
analyzed by means of Western blotting and localization in pancreatic tissue by
immunohistochemistry. RESULTS: C-met protein expression was significantly
upregulated in the regenerating pancreas and localized in areas of regenerating
tissue. Stimulation with cytokines resulted in a two- to threefold increase of c
met expression in vitro. CONCLUSION: Enhanced c-met expression after acute
pancreatitis suggests that HGF/met has an important role in pancreatic
regeneration, which is probably mediated by cytokines. This regulatory mechanism
is also of importance in pancreatic cancer.
PMID- 10672843
TI - Ultrasound-guided biopsies of abdominal organs with an automatic biopsy system. A
retrospective analysis of the quality of biopsies and of hemorrhagic
complications.
AB - BACKGROUND: Ultrasound-guided biopsies of abdominal organs are not without risks
for the patients; in particular, hemorrhagic complications may occur. Thus, over
the last few years, automatic biopsy guns have been developed to facilitate the
biopsy process. METHODS: The aim of our retrospective study was to examine the
quality of specimens and the complication rate of ultrasound-guided biopsies of
abdominal organs carried out in our institution using the automatic Autovac
biopsy system during a period of 1.5 years. Of the total number of 321 biopsies,
290 were performed with the 1.2-mm Autovac needle, and in 31 cases the 0.95-mm
needle was used. Among the 321 biopsies there were 211 of the liver parenchyma
(66%), 47 of a liver tumor (14%), 38 of the pancreas (12%), 15 of the kidney
parenchyma (5%), and 10 of a retroperitoneal tumor (3%). RESULTS: In 310 of the
321 biopsies it was possible to obtain sufficient diagnostically usable material
for the pathologist (96.6%). In the other 11 cases the material obtained did not
enable proper histologic diagnosis (3.4%). Two of these 11 biopsies were carried
out with the 0.95-mm needle, and the other 9 with the 1.2-mm needle. Twenty-four
hours after the biopsy each patient underwent routine ultrasound examination to
exclude a possible bleeding. In eight cases an afterbleeding occurred (total
hemorrhagic rate, 2.5%), four times without clinical consequences. The other four
bleeding complications were more serious (1.2% of all taps), and all occurred
after liver biopsies in patients with a history of liver complaints and abnormal
clotting variables. There were no fatalities among our biopsies (mortality rate,
0%). CONCLUSION: The automatic Autovac biopsy system is suitable and relatively
safe for obtaining sufficient histopathologic material from intra-abdominal
organs.
PMID- 10672842
TI - Vagal withdrawal during endoscopic retrograde cholangiopancreatography.
AB - BACKGROUND: Patients undergoing endoscopic retrograde cholangiopancreatography
(ERCP) are at risk of developing cardiorespiratory complications, but the
mechanism is still unknown. Treatment with metoprolol 2 h before the endoscopy
has been shown to decrease the incidence of myocardial ischaemia during ERCP. The
present study evaluated whether the endoscopic stress would decrease vagal tone
and whether metoprolol given before the procedure could prevent this defence-like
reaction. METHODS: Thirty-eight patients were randomized to receive either
placebo or 100 mg metoprolol 2 h before ERCP. During ERCP the patients were
monitored with a Holter tape recorder. Holter tapes from 31 patients (16
receiving metoprolol) were available to analyse the ratio of the standard
deviations of the RR intervals (SDRR) to the mean RR intervals (measure of vagal
tone) during ERCP. RESULTS: A decreased vagal tone during the ERCP was found, but
we observed no difference between the metoprolol and the placebo group. For both
groups the lowest vagal tone occurred at maximum heart rate during endoscopy. The
SDRR/meanRR ratio returned towards base line for the subsequent 60 min after
endoscopy. CONCLUSIONS: The existence of a defence-like reaction ('vagal
withdrawal') during ERCP has been shown. Metoprolol given 2 h before the
procedure did not affect the occurrence of this phenomenon. The interaction of
other periendoscopic factors is still unclear and should be studied further.
PMID- 10672844
TI - Actinomycosis of the colon: a rare form of presentation.
AB - Actinomycosis is an uncommon entity, caused by an anaerobic bacterium,
Actinomyces israelii, which is a component of the human oral and gastrointestinal
flora. The cervicofacial region is the commonest site of disease, and the abdomen
is the second commonest. In this situation the disease is almost always unifocal
and restricted to the right colon, especially to the cecum. We report here the
case of a patient with a very rare form of this entity, characterized by multiple
foci of abdominal involvement with the most severe lesions localized in the
transverse and sigmoid colon. The clinical presentation resembled a picture of
colon perforation by cancer or diverticulitis, and the diagnosis was made by
histopathologic examination of the lesions removed at surgery. No predisposing
factor was found. The infection was successfully treated with a prolonged course
of penicillin, after the surgical removal of the lesions.
PMID- 10672845
TI - Food intolerance and gallstones: erratum and update of a meta-analysis.
PMID- 10672846
TI - The role of Helicobacter pylori infection in gastroesophageal reflux disease.
PMID- 10672847
TI - Tetrahydrobiopterin improves endothelial function in patients with coronary
artery disease.
AB - Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide synthase
(NOS) and a scavenger of oxygen-derived free radicals. Decreased availability of
BH4 leads, under in vitro conditions, to reduced nitric oxide (NO) production and
increased superoxide formation. We studied the effect of exogenous BH4 on
endothelial function of angiographically normal vessel segments in patients with
coronary artery disease. Nineteen patients with coronary artery disease underwent
quantitative coronary angiography with simultaneous coronary flow velocity
measurements (Cardiometrics FloWire). Data were obtained in angiographically
normal segments of the left coronary artery at baseline, after intracoronary
(i.c.) administration of acetylcholine (Ach; 10(-4) M), after infusion of BH4
(10(-2) M), and after co-infusion of ACh and BH4. At the end of the study, 300
microg nitroglycerin (NTG) i.c. was administered to obtain maximal vasodilation.
At each step, flow velocity was determined before and after 18 microg adenosine
i.c. to assess coronary flow velocity reserve. In 15 patients, ACh induced
coronary vasoconstriction of -18 +/- 3% (endothelial dysfunction; p < 0.0001 vs.
baseline), and in four patients, vasodilation of +39 +/- 20%. In the 15 patients
with endothelial dysfunction, BH4 alone did not influence vessel area but
prevented vasoconstriction to ACh (+2 +/- 3%, NS, vs. baseline). Correspondingly,
calculated volume flow showed the highest value after co-infusion of ACh and BH4.
Coronary flow velocity reserve was comparable during the various infusion steps.
BH4 prevents ACh-induced vasoconstriction of angiographically normal vessels in
patients with coronary artery disease. Thus substitution of this cofactor of NOS
may represent a new approach for the treatment of endothelial dysfunction.
PMID- 10672848
TI - Treatment of atherosclerosis in apolipoprotein E-deficient mice with 4-(3
Bromobenzoyl)-6,7-dimethoxyquinazoline (WHI-P164), a potent inhibitor of
triglyceride synthesis.
AB - We identified a novel organic compound, 4-(3'-bromobenzoyl)-6,7
dimethoxyquinazoline (compound WHI-P164), as a potent inhibitor of triglyceride
(TG) synthesis. In an in vitro model of lipid synthesis, WHI-P164 (but not any
one of the three structurally similar control dimethoxyquinazoline compounds)
inhibited the accumulation of TG-rich intracellular lipid droplets in Caco-2
human intestinal cells in a concentration-dependent fashion. WHI-P164 caused no
acute toxicity associated with morbidity or mortality in mice when administered
at dose levels ranging from 0.5 to 80 mg/kg. In pharmacokinetic studies in mice,
WHI-P164 was rapidly eliminated from plasma with a terminal elimination half-life
of 26.1 +/- 1.3 min after intraperitoneal administration and 33.3 +/- 11.3 min
after intravenous administration. Treatment with 40 mg/kg WHI-P164 (but not one
of three structurally similar control dimethoxyquinazoline compounds)
administered intraperitoneally once daily for 7 consecutive treatment days
blocked the in vivo hepatic TG synthesis in both apoE-deficient and wild-type
C57B1/6 mice. In apoE-deficient mice maintained on a high-fat/high-cholesterol
Western diet, WHI-P164 substantially reduced the lipid accumulation in the liver
after 7 days of treatment and the lipid accumulation in the aorta after 1 month
of treatment. Our results in apoE-deficient mice show that lipid accumulation in
hepatocytes and foam cells are related events, and inhibiting TG synthesis with
WHI-P164 offers an effective means to treat atherosclerosis.
PMID- 10672849
TI - Effects of adenosine receptor agonists on efferent renal nerve activity in
anesthetized rats.
AB - The aim of this study was to investigate the effects of A1 and A2 adenosine
receptor activation on the sympathetic nervous system. The effects on efferent
renal nerve activity of selective A1 (CCPA; 2-chloro-N-6-cyclopentyladenosine)
and A2 (2HE-NECA; 2-hexynyl-5'-N-ethylcarboxamidoadenosine) adenosine-receptor
agonists were studied in anesthetized rats either with intact baroreflexes
(intact rats) or with bilateral sinoaortic denervation and vagotomy (denervated
rats). After a control period of 5 min, A1 or A2 agonist or vehicle were
intravenously infused for 8 min in separate groups of intact or denervated rats,
in which arterial pressure and heart rate were continuously recorded. CCPA (5.0
microg/kg/min) and 2HE-NECA (0.7 microg/kg/min) were selected to obtain
comparable blood pressure changes over the period of observation. Arterial
pressure significantly and equally decreased during the A1 (-41 +/- 8%), and A2 (
35 +/- 5%) agonist administration. Heart rate significantly decreased during A1
agonist infusion, but it did not change during A2 agonist administration.
Bilateral sinoaortic denervation and vagotomy did not modify the hemodynamic
responses to both drugs. The A1 and A2 administration caused a large and
significant increase in efferent renal nerve activity (+66 +/- 22% and +76 +/-
15%, respectively), and this effect was entirely abolished in denervated rats. A
linear relation with a significant negative slope between changes in arterial
pressure and changes in neural discharge was observed for each treatment. The
comparison of the regression slopes showed that the reflex increase of efferent
sympathetic activity caused by the administration of both agonists was
significantly smaller than the increment induced by equipotent hypotensive dose
of sodium nitroprusside (10 microg/kg). These data show that the selective
activation of A1 and A2 receptors elicits a reflex increase in efferent renal
nerve activity. This neural activation is smaller as compared with the effect of
equihypotensive doses of sodium nitroprusside, thus indicating a blunting effect
of both adenosine agonists on baroreceptor sensitivity.
PMID- 10672850
TI - Amlodipine enhances NO production induced by an ACE inhibitor through a kinin
mediated mechanism in canine coronary microvessels.
AB - Our previous study found that angiotensin-converting enzyme (ACE) inhibitors and
amlodipine induce NO release from coronary microvessels through a kinin-dependent
mechanism. The goal of this study was to determine whether amlodipine could
potentiate NO formation during ACE inhibition. Coronary microvessels were
isolated from 16 mongrel dogs. Nitrite, the hydration product of NO, from
coronary microvessels was quantified by using the Griess reaction. Bradykinin and
kallikrein all significantly increased nitrite release from coronary microvessels
in a concentration-dependent manner. The ACE inhibitor, ramiprilat, potentiated
these effects. Amlodipine also markedly potentiated nitrite production by
ramiprilat. For instance, amlodipine (10(-10) M) enhanced nitrite release induced
by ramiprilat (10(-7) M) from 122 +/- 9 to 168 +/- 14 pmol/mg (p < 0.05 vs.
ramiprilat). Nitrite release potentiated by ramiprilat and amlodipine was
entirely blocked by N(omega)-nitro-L-arginine methyl ester (L-NAME, an inhibitor
of NO synthase), HOE 140 (Icatibant, a specific B2-kinin receptor antagonist),
and dichloroisocoumarin (DCIC, a serine protease inhibitor that blocks local
kinin formation). These results clearly show that there is a synergistic effect
on NO formation when amlodipine is combined with ACE inhibition. Our data suggest
that kinin-mediated coronary NO production may contribute importantly to the
beneficial therapeutic action of ACE inhibitors, especially in combination with
amlodipine in the treatment of heart disease.
PMID- 10672851
TI - The protein kinase inhibitor fasudil protects against ischemic myocardial injury
induced by endothelin-1 in the rabbit.
AB - Endothelin-1 (ET-1) induces severe pathologic conditions such as coronary spasm
followed by vasospastic angina pectoris and acute myocardial infarction. The
related pathophysiologic mechanisms have remained obscure. Endothelin-1 receptor
(ET(A) and ET(B)) is reported to couple with several types of G protein-involved
pathways that participate in phospholipase C activation and atrial myofibrils
organization into sarcomeric units. Here we demonstrate that ET-1 induces
histologic and pathologic dysfunction in the rabbit myocardium and that such
pathologic events are prevented by the Rho-kinase inhibitor fasudil. Although the
bolus injection of ET-1 (1.4 nmol/kg) via the auricular vein of the rabbit
induced only transient T-wave elevation, irreversible, severe histologic changes
were observed in papillary muscles of the ventricle, and multifocal myocardial
necrosis with infiltration of neutrophils and macrophages in the left ventricle
occurred. Oral administration of fasudil (10 mg/kg) significantly reduced the
occurrence of myocardial injury determinants, whereas conventional Ca2+ channel
blockers (nifedipine, diltiazem) and a K+ channel opener (nicorandil; 10 mg/kg,
p.o. each) showed a lesser or no effect on such determinants. These results
suggest that ET-1 induces severe myocardial dysfunction based not only on the
occurrence of vasospastic ischemia but also on its direct effects on the
myocardium.
PMID- 10672852
TI - Methoxamine inhibits transient outward potassium current through alpha1A
adrenoceptors in rat ventricular myocytes.
AB - alpha1-Adrenoceptor agonists are known to reduce transient outward potassium
current (I(to)) in the heart. The aim of this study was to analyze the effect of
methoxamine (mtx) on I(to) and to elucidate which adrenoceptor subtype was
involved in this effect. We used the whole-cell configuration of the patch-clamp
technique to record I(to). Our experiments confirm that mtx induces a dose
dependent decrease of I(to) that is characterized by an acceleration of time to
peak (3.5 +/- 0.2 and 2.3 +/- 0.3 ms for control and mtx, respectively), and a
decrease in both inactivation time constants (T(fast) was reduced from 20.8 +/
2.6 to 14.9 +/- 1.1 ms, and tau(slow) was reduced from 138 +/- 32.1 to 114 +/-
28.7 ms; n = 7). All these effects were antagonized by prazosin and the alpha1A
antagonist 5-methylurapidil but not by the irreversible alpha1B-antagonist
chloroethylclonidine. These data indicate that stimulation of alpha1A
adrenoceptor subtype is involved in the methoxamine-induced reduction of I(to) in
rat ventricular myocytes.
PMID- 10672853
TI - Nitroprusside reverses lengthened time of contraction in stunned canine cardiac
myocytes.
AB - We tested the hypothesis that stunning reduces the function of isolated canine
ventricular myocytes and that nitroprusside (NP) reverses this effect. After
stunning (15 min occlusion, 45 min reperfusion), isolated myocytes were prepared
from control (circumflex artery) and stunned (left anterior descending) regions
of the hearts of seven dogs. The myocytes were examined at baseline and with NP
(10(-6,-5,-4) M) for oxygen consumption (MVO2, nl O2/min/10(5) cells), cyclic
guanosine monophosphate (cyclic GMP; fmol/10(5) cells), and cell contraction.
Basal MVO2 was not significantly different between control and stunned myocytes
(888 +/- 108 vs. 716 +/- 94). NP caused a dose dependent decrease in MVo2
(control, 262 +/-51; stunned, 287 +/- 59, NP 10(-4) M). Basal cyclic GMP levels
were comparable between control and stunned myocytes (117 +/-28 vs. 124 +/- 18).
NP produced a similar dose-dependent increase in cyclic GMP in control and
stunned myocytes. Baseline cell shortening (%) was similar in control vs. stunned
myocytes (12.1 +/- 1.2 vs. 11.0 +/- 0.9). NP reduced shortening (6.9 +/- 0.3 vs.
7.3 +/- 0.5, NP 10(-4) M). There was no baseline difference in maximal rate of
shortening (microm/s) between control and stunned myocytes (164 +/- 14, 157 +/-
20). With NP, a decrease in the maximal rate of shortening was seen in both
groups (128 +/- 12, 139 +/- 21, NP 10(-4) M). The time of contraction (s) was
significantly longer in stunned (0.20 +/- 0.03) versus control (0.13 +/- 0.01).
NP significantly lengthened the time of contraction in controls in a dose
dependent manner (0.33 +/-0.05, NP 10(-4) M). In stunned myocytes, however, low
dose NP (10(-6) M) caused a decrease in the time of contraction (0.15 +/-0.03).
High-dose NP (10(-4) M) did not significantly lengthen time of contraction in
stunned cells (0.23 +/- 0.02). The time of relaxation followed a similar pattern.
We conclude that part of the effect of NP in low doses in stunned myocardium is
to reduce the lengthened time of contraction and relaxation characteristic of
stunning.
PMID- 10672854
TI - Genistein potentiates the relaxation induced by beta1- and beta2-adrenoceptor
activation in rat aortic rings.
AB - In rat aortic rings, genistein, an inhibitor of tyrosine kinase, but not
daidzein, an inactive analogue of genistein, potentiated the relaxation induced
by isoproterenol. Atenolol, a beta1-adrenoceptor antagonist, or ICI-118,551, a
beta2-adrenoceptor antagonist, inhibited the relaxation induced by isoproterenol.
The potentiating effect of genistein on the relaxation induced by isoproterenol
in the presence of ICI-118,551 was apparently greater than that in the presence
of atenolol. In the presence of ICI-118,551, theophylline, an inhibitor of cyclic
adenosine monophosphate (cAMP)-dependent phosphodiesterase (cAMP-PDE), markedly
inhibited the potentiating effect of genistein on the isoproterenol-induced
relaxation, whereas in the presence of atenolol, theophylline only partly
inhibited the potentiating effect of genistein. The relaxation induced by
forskolin, an activator of adenylyl cyclase, was potentiated by genistein or
theophylline. In the presence of theophylline, the relaxation induced by
forskolin was not further affected by genistein. Genistein also inhibited the
activities of cAMP-PDE. In the presence of atenolol, but not ICI-118,551,
iberiotoxin, an inhibitor of Ca-activated K channels, inhibited the relaxation
induced by isoproterenol and the potentiating effect of genistein. In the
presence of atenolol, quinacrine, an inhibitor of phospholipase A2, and
metyrapone, an inhibitor of P-450 enzymes, but not alpha-naphthoflavone, an
inhibitor of P-450 enzymes, indomethacin, a cyclooxygenase inhibitor, or AA861, a
5-lipoxygenase inhibitor, inhibited the potentiating effect of genistein. These
results suggest that the potentiation of the beta1-adrenoceptor-induced
relaxation by activation of genistein may mostly be due to inhibition of cAMP-PDE
activities. In addition, the potentiation of the relaxation induced by activation
of beta2-adrenoceptors by genistein may be related to the inhibition of
arachidonic acid metabolism and cAMP-PDE activities.
PMID- 10672856
TI - Beneficial effects of the T- and L-type calcium channel antagonist, mibefradil,
against exercise-induced myocardial stunning in dogs.
AB - Abnormalities in calcium homeostasis such as calcium overload have been shown to
participate in the pathogenesis of myocardial stunning. The goal of this study
was to investigate the effects of mibefradil, a mixed T- and L-type calcium
channels antagonist on exercise-induced ischemia (i.e., high-flow ischemia). Nine
dogs were permanently instrumented to measure left ventricular wall thickening
(Wth) and coronary blood flow (Doppler). Infusion of saline or mibefradil (30 and
40 microg/kg/min, i.v., for 20 min) was started 10 min before exercise (10 min,
14 km/h; slope, 13%) and stopped at its end. Circumflex coronary artery stenosis
(pneumatic occluders) was set up 5 min before exercise to suppress exercise
induced increase in mean coronary blood flow without simultaneously affecting Wth
at rest. Mibefradil (30 microg/kg/min) was also administered at the beginning of
the recovery period in a subset of four dogs. During exercise with saline, Wth
was dramatically reduced (-77 +/- 7%; p < 0.05) and recovered only after 24 h.
Mibefradil at both doses significantly limited tachycardia during exercise (211
+/- 7 and 210 +/- 5 beats/min vs. 240 +/- 8 beats/min for mibefradil, 30
microg/kg/min, mibefradil, 40 microg/kg/min, and saline, respectively) but
exerted no negative inotropic effects. Mibefradil at both doses significantly
reduced the intensity of myocardial stunning and the time to recovery in Wth (3
h). Administration of mibefradil at the beginning of the recovery period did not
protect against myocardial stunning. Administration of a mixed T- and L-type
calcium channel antagonists before ischemia confers cardioprotection against
exercise-induced myocardial stunning. This may potentially be related to the
limitation of exercise-induced tachycardia and/or the prevention of calcium
overload.
PMID- 10672855
TI - Butanolic fraction from Cuphea carthagenensis Jacq McBride relaxes rat thoracic
aorta through endothelium-dependent and endothelium-independent mechanisms.
AB - This study evaluated the vasorelaxant properties of the crude hydroalcoholic
extract (CE) of Cuphea carthagenensis, as well as its butanolic (BF) and ethyl
acetate (EA) fractions, in rings of rat thoracic aorta. In endothelium-intact
rings contracted with phenylephrine (30-100 nM), cumulative additions of
increasing concentrations of CE, BF, and EA of C. carthagenensis (0.1 microg/ml-3
mg/ml) caused graded relaxations, with BF displaying the lowest median inhibitory
concentration (IC5; mean, 6.8 microg/ml; 95% confidence limits, 3.3-14.2). BF
induced relaxations of endothelium-intact rings were virtually abolished by prior
incubation with the NO-synthase inhibitor N(omega)-nitro-L-arginine (L-NOARG; 10
or 30 microM), and were markedly reduced after guanylate cyclase inhibition with
either methylene blue (10 microM) or ODQ (1 microM; 1H[1,2,4]oxadiazolo[4,3
a]quinoxalin-1-one). The inhibition of BF-induced relaxation by L-NOARG was
prevented to a large extent by simultaneous incubation with L-arginine (1 mM). In
endothelium-denuded rings contracted with phenylephrine, CE and BF caused graded
relaxations only at doses >100 microg/ml, whereas the NO-donors SNAP (S-nitroso-N
acetyl-penicillamine) and SIN-1 (3-morpholino-sydnonimine) induced full
relaxation at 1 microM. BF (100 microg/ml), which caused little relaxation per se
of endothelium-denuded rings, potentiated the relaxant effects of SNAP and even
more so of SIN-1 (which, unlike SNAP, also releases superoxide anion O2- in
addition to NO), in a manner qualitatively similar to that seen with SOD
(superoxide dismutase) against SIN-1. These data indicate that the BF of C.
carthagenensis induces relaxation of the rat thoracic aorta by two mechanisms:
(a) an endothelium-dependent component of action, which clearly depends on the
NO/cyclic guanosine monophosphate (cGMP) pathway and can be attributed, at least
in part, to free radical-scavenging properties; and (b) an endothelium
independent component of action, which becomes evident at higher doses (> or =
100 microg/ml) and remains to be further characterized. These results suggest
that this native South American plant might be beneficial in cardiovascular
disease.
PMID- 10672857
TI - Intracoronary enalaprilat improves metabolic coronary vasodilation in patients
with idiopathic dilated cardiomyopathy.
AB - Coronary flow reserve is reduced in patients with idiopathic dilated
cardiomyopathy (DCM). We examined acute effects of intracoronary enalaprilat on
metabolic coronary vasodilation during pacing tachycardia in patients. Coronary
blood flow (Doppler guidewire) and diameter (quantitative angiography) were
measured in seven patients with DCM and seven control subjects. In the DCM group,
tachypacing increased coronary blood flow by 37 +/- 22% from the baseline before
enalaprilat and by 65 +/- 22% (p < 0.01 vs. before treatment) after enalaprilat
(0.5 microg/kg/min for 5 min, i.c.) at comparable double product. Pacing-induced
dilation of the epicardial coronary artery also was greater after enalaprilat (p
< 0.05). Effects of enalaprilat on coronary blood flow and diameter during pacing
tachycardia were abolished by pretreatment with intracoronary administration of
the nitric oxide (NO) synthesis inhibitor, N(G)-monomethyl-L-arginine. These
beneficial effects of enalaprilat on large and small coronary vasodilation were
not observed in control patients. Thus, intracoronary enalaprilat acutely
augmented dilator responses of the large and small coronary arteries to pacing
tachycardia in patients with DCM, and NO appeared to play an important role in
mediating the effects of enalaprilat. These favorable effects of enalaprilat on
the coronary circulation may be of clinical significance in patients with heart
failure due to nonischemic DCM. Further long-term studies of the effects of
angiotensin-converting enzyme inhibition on coronary vasodilation will be needed
in this population.
PMID- 10672858
TI - Lipophilic HMG-CoA reductase inhibitors increase myocardial stunning in dogs.
AB - Pretreatment of dogs with simvastatin, a lipophilic 3-hydroxy-3-methylglutaryl
coenzyme A (HMG-CoA) reductase inhibitor, increases myocardial contractile
dysfunction during reperfusion after ischemia (stunning), with reduction of
tissue adenosine triphosphate (ATP). This was thought to be a consequence of
prevention of ubiquinone biosynthesis by the lipophilic inhibitor in the
myocardial cell. We examined whether other lipophilic HMG-CoA reductase
inhibitors also influence myocardial stunning in dogs. Vehicle, atorvastatin (2
mg/ kg/day), fluvastatin (4 mg/kg/day), or cerivastatin (40 microg/kg/ day) was
orally administered for 3 weeks. Hydrophilic pravastatin (4 mg/kg/day) also was
given. After 3 weeks, pentobarbital-anesthetized dogs were subjected to 15-min
left anterior descending coronary artery occlusion followed by 2-h reperfusion.
Myocardial segment function was determined by sonomicrometry. Tissue levels of
ATP were determined in 2-h reperfused hearts. All inhibitors significantly
decreased serum cholesterol level. The three lipophilic inhibitors resulted in a
worsening of segment function in the reperfused myocardium, as compared with the
vehicle group. The levels of ATP in the atorvastatin, fluvastatin, and
cerivastatin groups were significantly lower than that in the vehicle group.
These results confirm that lipophilic HMG-CoA reductase inhibitors enhance
myocardial stunning in association with ATP reduction after ischemia and
reperfusion.
PMID- 10672859
TI - Myocardial protection with red wine extract.
AB - Cardioprotective action of red wine was studied by preperfusing isolated rat
hearts with ethanol-free red wine extract for 15 min before subjecting them to 30
min of global ischemia followed by 2 h of reperfusion. Four other group of rats
were studied under identical conditions, of which one served as control; one was
treated with 10 microM trans-resveratrol (RVT), one of the major antioxidants
found in red wines; another, with 0.07% ethanol; and another, with 0.07% ethanol
plus 10 microM RVT. The results of our study demonstrated that both red wine
extract and RVT were equally cardioprotective, as evidenced by their abilities to
improve postischemic ventricular functions including developed pressure and
aortic flow. Developed pressure values at 60 min after reperfusion were 81.8 +/-
1.2 and 68.8 +/- 4.1 mm Hg for the red wine extract and RVT groups, respectively,
versus 49.7 +/- 2.7 mm Hg for the control group. These compounds also reduced
myocardial infarct size compared with the control hearts (20.1 +/- 0.5% and 10.5
+/- 0.3% for red wine extract and RVT groups, respectively, vs. 29.9 +/- 3.1% for
the control group). The ethanol-treated group displayed slightly better
functional recovery, which deteriorated sharply toward the end of the reperfusion
period, and the extent of infarction was comparable to that of the control group
(31.5 +/- 0.9%). In the ethanol plus RVT group, postischemic contractile function
was significantly better than control, and infarct size also was reduced to 20.9
+/- 0.7%. The amount of malonaldehyde formation in the postischemic myocardium
was reduced by red wine extract and RVT, indicating a reduction of oxidative
stress developed in the ischemic reperfused myocardium. In vitro studies revealed
that red wine extract is a potent antioxidant as evidenced by its ability to
scavenge peroxyl radical in vitro. Taken together, the results of our study
indicate that red wines are cardioprotective by their ability to function as an
in vivo antioxidant.
PMID- 10672860
TI - A peripheral site of action for the attenuation of baroflex-mediated bradycardia
by intravenous mu-opioid agonists.
AB - We previously reported that i.v. DAMGO (Tyr-D-Ala-Gly-NMePhe-Gly-ol), a selective
mu-opioid agonist, causes an increase in blood pressure with no change in heart
rate in unanesthetized sheep and subsequently demonstrated that DAMGO attenuates
baroreflex-mediated bradycardia. To determine the site and mechanism by which mu
agonists inhibit baroreflex sensitivity, we have carried out further
investigations by using DAMGO and another mu-agonist, DALDA (Tyr-D-Arg-Phe-Lys
NH2). The bradycardic response to norepinephrine (NE) was significantly blunted
after i.v. DAMGO or DALDA in both nonpregnant and pregnant sheep. In contrast,
the tachycardic response to sodium nitroprusside (SNP) remained unchanged in the
presence of DAMGO or DALDA. In view of the highly restricted distribution of
DALDA across the blood-brain barrier (BBB), we hypothesized that the blunting of
reflex-mediated bradycardia by mu-opioid agonists can occur peripherally.
Pretreatment with the quaternary opioid antagonist, naloxone methiodide (NM),
completely blocked the attenuation of baroreflex sensitivity by DAMGO and DALDA
in both nonpregnant and pregnant animals. These data suggest that in addition to
central mechanisms, mu-opioid agonists can inhibit baroreflex sensitivity at a
peripheral site, most likely by inhibiting vagal influence on heart-rate control
rather than by acting directly at baroreceptors.
PMID- 10672861
TI - Insulin-like growth factor-I improves recovery of cardiac performance during
reperfusion in isolated rat heart by a wortmannin-sensitive mechanism.
AB - Insulin-like growth factor-I (IGF-I) has been shown to produce a short-term
positive inotropic effect (PIE) in the myocardium under nonischemic conditions.
IGF-I also conferred cytoprotection against ischemia and reperfusion injury in
various organs. IGF-I may, therefore, facilitate the recovery of postischemic
cardiac function. Isolated and crystalloid-perfused rat heart was subjected to 25
min of normothermic ischemia followed by 30 min of reperfusion. IGF-I produced
PIE in a dose-dependent manner at concentrations ranging between 1 and 100 nM
under nonischemic conditions. Although 1 nM isoproterenol produced much greater
PIE and myocardial energy conversion efficiency (MECE) than did 65 nM IGF-I in
this condition, the same concentration of IGF-I administered during reperfusion
conferred better recovery of left ventricular function and MECE compared with
isoproterenol. The improved cardiac performance by IGF-I was associated with
lower release of creatine kinase (CK). Wortmannin (100 nM), a specific inhibitor
of phosphatidylinositol kinase (PI-3 kinase), abrogated IGF-I-induced improvement
of contractile function and inhibition of CK release in the postischemic heart.
We conclude that IGF-I administered during reperfusion accelerates recovery of
cardiac performance and mitigates myocardial injury through a wortmannin
sensitive mechanism.
PMID- 10672862
TI - The role of cromakalim and a nitric oxide synthase blocker in cardiac arrhythmia
in the intact baboon model.
AB - The arrhythmogenic effect of adenosine triphosphate (ATP)-sensitive potassium
channel openers is controversial and may be dependent on the type of animal model
used. Information on the effect of these drugs in the normal primate model is
limited. The purpose of this study was first to determine the arrhythmogenic
properties of cromakalim in the baboon and second to determine whether N-omega
nitro-L-arginine methyl ester (L-NAME) has any effect on the induced arrhythmia.
Adult (2-4 years old) baboons (Papio ursinus) were anesthetized with a continuous
i.v. infusion of ketamine (100 mg/ ml), diazepam (5 mg/ml), and saline (ratio
2:2:50) at a rate of 40-60 ml/h. Sympathetic responses were inhibited by
administration of propranolol (1 mg/kg) before the start of the experiments.
Cromakalim (30 microg/kg) was administered before and after L-NAME (7.5 mg/kg),
and the parameters were monitored for 15 min after each intervention. A Millar
double-tipped microcatheter was used to record left ventricular and aortic
pressures. Lead II of the ECG was monitored. During a 15-min period after
administration of cromakalim, 22.3 +/- 6.0 abnormal ventricular complexes were
recorded. L-NAME administration significantly reduced these abnormal complexes to
4.5 +/- 2 (paired t test, p < or = 0.05). We therefore conclude that cromakalim
has arrhythmogenic properties in the baboon and that these can be attenuated by L
NAME.
PMID- 10672863
TI - Effects of the K+ channel opener KRN4884 on the cardiovascular metabolic syndrome
model in rats.
AB - We examined the effects of the potassium channel opener KRN4884 (5-amino-N-[2-(2
chlorophenyl)ethyl]-N'-cyano-3-pyridinecarboxamidine ) on cardiovascular
metabolic syndrome (i.e., syndrome X), in rats. High-fructose diet rats developed
hypertension, hypertriglyceridemia, increased total cholesterol/HDL (high-density
lipoprotein)-cholesterol ratio, and hyperinsulinemia, KRN4884 (0.3-3.0 mg/kg,
twice a day for 14 days, p.o.) alleviated the risk factors in fructose-fed rats.
Furthermore, fructose-fed rats exhibited impairment of glucose tolerance and
excess insulin secretion when loaded with glucose orally. Treatment with KRN4884
(1.0 mg/kg, twice a day for 14 days, p.o.) improved the glucose intolerance and
inhibited hypersecretion of insulin in the glucose-loaded, fructose-fed rats. In
contrast, KRN4884 (0.3-1.0 mg/kg, twice a day for 10 days, p.o.) did not affect
serum triglyceride, cholesterol, glucose, or insulin concentrations in normal
rats. LPL (lipoprotein lipase) activities in skeletal muscle and adipose tissue,
and HTGL (hepatic triglyceride lipase) activity in liver were measured after
administration of KRN4884 or vehicle twice a day for 14 days in fructose-fed
rats. KRN4884 caused a significant increase in LPL activity in muscle and tended
to increase LPL activity in adipose tissue in fructose-fed rats. HTGL was
decreased in fructose-fed rats as compared with normal controls and was
unaffected by KRN4884. These findings suggested that KRN4884 enhances insulin
sensitivity and LPL activity, which are related to glucose and lipid metabolism
and may be useful for the treatment of syndrome X.
PMID- 10672864
TI - Sarpogrelate, a selective 5-HT2A serotonergic receptor antagonist, inhibits
serotonin-induced coronary artery spasm in a porcine model.
AB - Serotonin is one of the most important vasoactive substances and has been
implicated in the pathogenesis of coronary artery spasm and of acute coronary
syndrome. We have recently demonstrated that local and long-term treatment with
interleukin-1beta(IL-1beta) causes coronary arteriosclerotic changes and
hyperconstrictive responses to serotonin in pigs in vivo. However, it remains to
be examined which serotonergic (5-HT) receptor subtype mediates coronary spasm
and whether alterations in serotonergic receptors are involved in the
abnormality. In this study, we examined the inhibitory effect of sarpogrelate, a
selective 5-HT2A serotonergic receptor antagonist, on the serotonin-induced
coronary spasm as well as the possible alterations of serotonergic receptors in
our porcine model. A segment of the porcine coronary artery was carefully
dissected and aseptically wrapped with cotton mesh absorbing IL-1beta-bound
microbeads from the adventitia. Two weeks after the procedure, angiographic study
was performed, followed by binding assay for 5-HT1B and 5-HT2A serotonergic
receptors and reverse transcription-polymerase chain reaction (RT-PCR) analysis
for mRNA of those receptors. Angiographic study showed coronary vasospastic
responses to serotonin at the IL-1beta-treated site. Sarpogrelate dose
dependently inhibited the serotonin-induced coronary spasm, but it did not affect
the prostaglandin F2alpha-induced vasoconstriction. Radiolabeled receptor-binding
assay showed that receptor affinity or receptor number of the 5-HT1B, or 5-HT2A
receptors did not differ significantly between the spastic and the control sites.
Furthermore, RT-PCR analysis showed that the expression of neither 5-HT2A nor 5
HT1B receptor mRNA was significantly altered at the spastic site. These results
indicate that serotonin-induced coronary spasm is mediated primarily by 5-HT2A
receptor in our porcine model, although the 5-HT2A receptor was not up-regulated,
suggesting that alteration in the signal-transduction pathway for vascular smooth
muscle contraction beyond the 5-HT2A receptor plays a primary role in the
pathogenesis of coronary spasm in our porcine model.
PMID- 10672865
TI - RAR gamma agonists inhibit proliferation of vascular smooth muscle cells.
AB - The multifactorial and unpredictable nature of human restenosis will probably
necessitate interventional strategies that target multiple processes involved in
neointimal proliferation. Retinoids represent a growing class of pleiotropic
biologic response modifiers with demonstrable efficacy in managing several
pathologic conditions pertaining to neointimal proliferation. However, retinoid
treatment is associated with a high incidence of adverse effects. The action of
all-trans-retinoic acid is mediated by two families of nuclear receptors, RARs
and RXRs, each containing three isoforms alpha, beta, and gamma. Because
synthetic retinoids that are receptor and function specific have been shown to
differ from each other by several orders of magnitude in their potencies and are
associated with limited adverse effects, we examined the effect of synthetic
retinoids on serum- and serotonin-induced vascular smooth muscle cell (VSMC)
proliferation. Naturally occurring retinoids were used as controls. All-trans
retinoic acid at nanomolar concentrations inhibited smooth muscle cell
proliferation. In this study, we report that RAR gamma subgroup-specific agonists
are the most potent inhibitors of serum and serotonin VSMC proliferation, as
compared with other RAR pan-agonists and naturally occurring retinoids tested.
Our results indicate that RAR gamma subgroup-specific agonists should be assessed
further in in vivo models of neointimal proliferation.
PMID- 10672866
TI - Efficacy of the novel calcium antagonist R(+)-semotiadil in limiting the
ventricular rate during atrial flutter in isolated guinea pig hearts.
AB - Ca2+ antagonists slow the ventricular rate by blocking conduction in the
anterograde direction through the atrioventricular (AV) node. The aim of this
study was to investigate the efficacy of the novel Ca2+ antagonist semotiadil
compared with verapamil and diltiazem on the filtering capacity of the AV node
during simulated atrial flutter in isolated guinea-pig hearts perfused by the
method of Langendorff. During sinus rhythm, semotiadil as well as verapamil and
diltiazem induced comparable depressant effects on AV-nodal conduction time and,
during tachycardia, a comparable enhancement of this effect. The time constant
(tau-on) for the drug-specific rate-dependent effect on AV-nodal conduction
slowing was longest in the presence of verapamil compared with the long tau-on of
semotiadil and the short tau-on of diltiazem. Verapamil and semotiadil exhibited
a significantly greater effect than diltiazem on the mean ventricular cycle
length (VCLmeun), on the maximal ventricular cycle length (VCLmax) and on the
standard deviation of the VCL (SD(VCL)) during atrial flutter. Therefore the
kinetics of the rate adaptation of AV-nodal conduction time in the presence of
Ca2+ antagonists predicts the filtering capacity of the AV node during atrial
flutter. Semotiadil has a verapamil type of action on ventricular cycle length
during atrial flutter, whereas the disadvantageous prolongation of maximal VCL as
well as the dispersion of VCL with semotiadil was only about half those found
with verapamil.
PMID- 10672867
TI - Role of NPY Y1 receptors in cardiovascular control in the conscious rabbit.
AB - Prejunctional neuropeptide Y (NPY) Y1 receptors on cardiac sympathetic neurons
mediate transient inhibition of chronotropic responses in rabbit isolated right
atria. The function of these receptors remains speculative. We investigated a
possible functional role for these receptors in modulation of the baroreceptor
heart rate (HR) reflex in the conscious rabbit. Mean arterial pressure (MAP)
responses to a range of doses of the Y1 receptor agonist [Leu31,Pro34]NPY (1-8
microg/kg, i.v.) were constructed in ganglion-blocked rabbits. After
administration of the selective Y1 receptor antagonist GR231118(150 microg/kg,
i.v.), two-point [Leu31,Pro34]NPY dose-pressor responses were assessed. Linear
regression analysis of the relation between the shift in the [Leu31,Pro34]NPY
dose-pressor response lines against time was used as an estimate of the
functional half-life of GR231118. GR231118 shifted the two-point [Leu31,Pro34]NPY
dose-pressor response relation by 10- to 30-fold. A single estimate of the
functional half-life of a bolus dose of GR231118 was 25 +/- 2 min. This
determination allowed a steady-state Y1-receptor blockade to be established by a
bolus and infusion. In a separate group of rabbits, the baroreceptor-HR reflex
was assessed before and 30 min after administration of GR231118 (150 microg/kg
bolus, then 150 microg/ kg/h, i.v.). GR231118 caused an initial transient pressor
response and bradycardia, followed by a depressor response and a more sustained
tachycardia. Infusion of GR231118 had no effect on the baroreceptor-HR reflex.
Prejunctional Y1 receptors appear not to mediate a tonic inhibition of cardiac
sympathetic neurotransmission in the conscious rabbit during physiological
manipulations in MAP. However, activation of postjunctional Y1 receptors by
neuronal or circulating NPY may be important in maintenance of vascular tone in
the conscious rabbit.
PMID- 10672868
TI - Antagonism of coronary artery relaxation by adenosine A2A-receptor antagonist
ZM241385.
AB - We have tested the existence of functional A2A adenosine receptor in porcine
coronary artery using, for the first time, the new A2A antagonist ZM241385.
Nonselective agonist NECA and A2A-selective agonist CGS21680 produced
concentration-dependent relaxation of prostaglandin F2alpha (PGF2alpha)
precontracted endothelium intact (E+) and denuded (E-) rings. Relaxation was
significantly greater in E+ rings than in E-rings. A2A adenosine receptor
selective antagonist, ZM241385 (10(-6) M), significantly attenuated the
relaxation responses. The antagonism of ZM241385 was compared with that of
SCH58261 (10(-6)M), another A2A adenosine receptor-selective antagonist, which
also significantly attenuated the relaxation response to both agonists. However,
ZM241385 produced a significantly greater shift of the relaxation-response curves
to the right compared with SCH58261 both in E+ and E- rings. The data show for
the first time that ZM241385 is a potent A2A-receptor antagonist in porcine
coronary artery and a useful tool to study A2A-receptor function.
PMID- 10672869
TI - Relaxation to flavones and flavonols in rat isolated thoracic aorta: mechanism of
action and structure-activity relationships.
AB - The mechanism of the relaxant action and the structure-activity relation of
flavonols (fisetin, quercetin, and 3,3',4'-trihydroxyflavone) and flavones
(apigenin, chrysin, and luteolin) were examined in rat isolated thoracic aorta.
The control responses to flavonols and flavones were compared with responses
observed after the removal of the endothelium or in the presence of the L-type
Ca2+ channel blocker, nifedipine (10(-7) M). The effects of flavonoids on
contraction caused by the influx of extracellular Ca2+ and agonist-induced
release of intracellular Ca2+ also were investigated. The flavones exhibited
endothelium-independent vasorelaxation, whereas the removal of the endothelium
significantly decreased the sensitivity of the relaxant responses to the
flavonols without affecting the maximal relaxation. In the presence of
nifedipine, the responses to apigenin, luteolin, and quercetin were significantly
inhibited, but relaxation to chrysin, fisetin, and 3,3',4'-trihydroxyflavone was
unaffected. All flavonols and flavones caused concentration-dependent inhibition
of the contractile responses to exogenous application of Ca2+ and the release of
intracellular Ca2+ stimulated by phenylephrine. Of the six flavonoids examined,
3,3',4'-trihydroxyflavone was the most potent when causing vasorelaxation or
inhibition of contraction caused by the influx or release of Ca2+. In conclusion,
these studies provide evidence that the hydroxyl substitution in the carbon 3
position that characterizes the flavonols is important in stimulating endothelium
dependent vasorelaxation, and the absence of hydroxyl substitution on the A
phenolic ring enhances the relaxant action.
PMID- 10672870
TI - Analysis of the electrophysiologic effects of short-term oxybutynin on guinea pig
and rabbit ventricular cells.
AB - The objective of this study was to investigate the cardioactive properties of
oxybutynin, a drug that is widely prescribed for management of voiding
dysfunction. Membrane currents were recorded from whole-cell-configured guinea
pig ventricular myocytes, and action potentials were recorded from guinea pig and
rabbit papillary muscles. L-type Ca2+ current (I(Ca),L), inward-rectifier K+
current (I(K1)), and delayed-rectifier K+ current (I(K)) were unaffected by < or
= 1 microM oxybutynin, and inhibited by higher concentrations. The concentrations
that reduced the currents to one-half of predrug control amplitude (K0.5) were as
follows: 1(Ca),L, 16.1 microM, I(K1), 18.2 microM, rapidly activating
I(K)(I(Kr)), 11.4 microM, and slowly activating I(K)(I(Ks)), 28.7 microM. Action
potential durations at 20 and 90% repolarization (APD20, APD90) were unaffected
by oxybutynin < or =3 microM in guinea pig papillary muscles driven at 1 Hz;
higher concentrations selectively shortened the APD20 by as much as 25% (100
microM), and caused moderate reductions in maximal upstroke velocity. Changes in
the action potentials of rabbit papillary muscles were even smaller than in the
guinea pig muscles. Because the peak therapeutic plasma concentration of
oxybutynin is in the 0.01-0.1 microM range, the results suggest that the drug is
highly unlikely to have adverse effects on cardiac electrical activity.
PMID- 10672871
TI - Perillyl alcohol, an inhibitor of geranylgeranyl transferase, induces apoptosis
of immortalized human vascular smooth muscle cells in vitro.
AB - The isoprenoids geranylgeraniol and farnesol are required for lipid modification
of several important cellular proteins. In this study the effect of perillyl
alcohol (PA), an inhibitor of geranylgeranyl transferase, was examined on
proliferation and apoptosis of immortalized human vascular smooth muscle cells
(HVSMCs) derived from saphenous vein. PA induced a time- and concentration
dependent inhibition of cell proliferation over 3 days and 48 h exposure to PA
inhibited [methyl-3H-thymidine incorporation induced by 10% fetal calf serum in a
concentration-dependent manner. Flow cytometry analysis indicated that PA reduced
the proportion of cells in S phase and increased apoptosis. PA-induced apoptosis
was confirmed by terminal deoxynucleotidyl transferase (TdT) reagent-based
immunocytochemistry. In contrast, the selective inhibitors of farnesyl
transferase B581 and BZA-5B were without effect. In view of the proposed role of
proliferation and apoptosis in myointimal hyperplasia, inhibitors of
geranylgeranyl transferases may have therapeutic potential in cardiovascular
disease.
PMID- 10672872
TI - Design of computer-generated hologram with ring focus for nonmechanical corneal
trephination with Er:YAG laser in penetrating keratoplasty.
AB - PURPOSE: To calculate a beam-shaping optical element for homogeneous intensity
distribution within a focal ring to be used in nonmechanical trephination with
the Er:YAG laser in penetrating keratoplasty instead of a spot guiding device.
METHODS: The phase distribution behind a holographic optical element (HOE) k
psi(u) can be described by the addition of the hologram phase phiH(u) to the beam
phase phiE(u): k psi(u) = phiH(u) + phiE(u), k = 2pi/lambda, where u denotes the
coordinates inside the hologram aperture, k an integer, and lambda the laser
wavelength. To avoid discontinuous wavefronts leading to speckle noise, a smooth
phase function is necessary. After transforming the hologram aperture coordinates
into the focal plane x in a focal distance f, psi can be retrieved from the slope
equation: inverted delta psi(u) = x(u) - u/f. RESULTS: Creating a ring focus can
be reduced to an essentially one-dimensional problem by separation of variables
due to the symmetry condition. We calculated a computer-generated eight-level
phase-only HOE with 4096 x 4096 pixels from a Gaussian-distributed 2.94 Er:YAG
laser spot with a beam diameter of 10 mm and a focal distance of 100 mm. Thereby,
a ring focus with an inner/outer radius of 7/8 mm can be created. To avoid
Poisson's spo, the symmetry of the problem was broken by circular modulation of
the phase leading to a spiral-like structure. The calculated efficiency of the
HOE relating the energy within the ring to the total energy was 91%. CONCLUSION:
With an HOE it is possible to redistribute the energy along the desired focal
ring. The HOE design can be adapted to the intensity distribution of the
impinging laser beam with its characteristic aperture shape. A circular
homogeneous corneal trephination depth is possible, because the energy
fluctuation from pulse to pulse does not locally affect the ablation process. A
ring focus for the Er:YAG laser has the potential to render superfluous a manual
beam control via micromanipulator and to allow a more rapid and more regular
corneal trephination along aperture masks.
PMID- 10672873
TI - Expression of stress-response protein 60 in iritis associated with experimental
autoimmune encephalomyelitis.
AB - PURPOSE: To study the expression of stress-response proteins in the inflamed iris
of rats with experimental autoimmune encephalomyelitis (EAE). METHODS: EAE was
induced in Lewis rats by immunization with homogenized spinal cord of the guinea
pig emulsified in complete Freund's adjuvant (CFA) (group EAE). Control rats
included those immunized with only CFA (group CFA) and those that were untreated
(group Normal). Immunohistochemical study for the localization of stress-response
protein (srp) 27, srp 60, srp 72, ubiquitin, and alphaB-crystallin was performed.
RESULTS: All rats in group EAE developed iritis, whereas none of the rats in
group CFA and group Normal developed iritis. No expression of ubiquitin, alphaB
crystallin, srp 27, srp 60, or srp 72 was seen in the epithelium of the iris in
group CFA rats. In the eyes of rats in group EAE, srp 60 was expressed in the
epithelium of the iris in 20 of 22 (90.9%), ubiquitin in 4 of 22 (18.2%), and
alphaB-crystallin in 3 of 22 (13.6%). In the group Normal rats, only ubiquitin
was expressed in the epithelium of the iris in 1 of 6 (16.7%) eyes examined.
CONCLUSIONS: These results suggest that srp 60 may be a potential uveitogenic
antigen in the iris in EAE.
PMID- 10672874
TI - Prior topical anesthesia reduces time to full cycloplegia in Chinese.
AB - PURPOSE: To investigate the effect of prior anesthesia on the time to full
cycloplegia in young Chinese subjects. METHODS: The amplitude of accommodation
was monitored over a 50-minute interval after the application of 1%
cyclopentolate hydrochloride with a pretreatment of 0.4% benoxinate
(oxybuprocaine) or 0.9% saline solution (control). Using a nonlinear mathematical
model, the rate of accommodative loss (k) and the time required for 95% of total
cycloplegia (T95%) were determined. RESULTS: Statistical analysis revealed a
significantly faster rate of accommodative loss (P < .0001) after prior
anesthesia (0.129 +/- 0.05) compared with the controls (0.103 +/- 0.04). T95% was
noted at 26.43 +/- 10.22 minutes after prior anesthesia, which was significantly
shorter (P < .0001) than that after the saline treatment (35.28 +/- 16.51
minutes). CONCLUSIONS: Prior application of topical anesthetic can shorten the
time to full cycloplegia for people, such as the Chinese, with dark irides.
PMID- 10672875
TI - Sorsby's fundus dystrophy in two Japanese families with unusual clinical
features.
AB - PURPOSE: To describe two Japanese families with Sorsby's fundus dystrophy (SFD)
with unusual clinical features. METHODS: Two families from Kagoshima Prefecture
with senile-onset macular dystrophy were examined. Three affected individuals
through three successive generations of one family and three affected siblings in
another family were examined and followed. RESULTS: The initial symptom of these
patients was a rapid or slow central visual loss that occurred at an average age
of 67.4 years. The major ophthalmoscopic changes consisted of soft drusen and
hemorrhagic or atrophic lesions in the macula, which were progressive and
ultimately led to disciform scarring. They had no difficulty with night vision.
All the patients had normal peripheral retina with intact peripheral fields. They
maintained good ambulatory vision and could walk unguided until late in life.
These patients had a novel mutation in the tissue inhibitor of the
metalloproteinases-3 (TIMP3) gene. CONCLUSIONS: This is the first report of SFD
from the East. Its clinical features differ from those of SFD patients of the
West, appearing closer to features of age-related macular degeneration. These two
unrelated Japanese families with an identical mutation in the TIMP3 gene might be
descendants of a common ancestor who carried the mutant gene.
PMID- 10672876
TI - Effects of stimulus blocking, light scattering, and distortion on multifocal
electroretinogram.
AB - PURPOSE: To investigate how the multifocal electroretinogram (ERG) is altered in
conditions of blocking, light scattering, or distortion of the stimulus that are
seen in ocular pathologies. METHODS: A central 40 degree-diameter stimulus
pattern consisting of 61 hexagons was presented on a cathode ray tube monitor at
a rate of 75 Hz according to the pseudo-random binary M sequence by the Veris
computer program. Localized responses corresponding to each hexagon and ERG
topographies were displayed on the computer screen. Central scotoma was simulated
by blocking the central area of the stimulus, visual field constriction by
blocking the outer area of the stimulus, mild cataract by using acrylic filters
that caused light scatter, and epiretinal membrane by using a wavy plastic plate
that produced metamorphopsia. RESULTS: The responses from the blocked area were
nonrecordable whether blockage was central or peripheral; responses from the
adjacent unblocked area had a larger amplitude when large areas of the stimulus
were blocked. The light scatter that decreased vision from 20/20 to 20/70 did not
significantly decrease response amplitudes. Responses from areas in which the
stimulus pattern was distorted were minimally affected. CONCLUSIONS: The results
show that the system records local ERGs from the macula and outside the macula.
It can detect the area where the stimulus is blocked. Moderate light scattering
and distortion do not cause loss of local ERG characteristics.
PMID- 10672877
TI - Effect of continuous intravenous infusion of carteolol chloride on tissue blood
flow in rabbit optic nerve head.
AB - PURPOSE: To investigate the effect of an intravenous infusion of carteolol on
tissue blood flow in the optic nerve head (ONH) of rabbits. METHODS: Rabbits
received either a 3-week topical instillation, or a single intravenous injection
(10, 20, 30 microg/kg) or a continuous intravenous injection (2.5, 5, 20, 40, 80
microg/kg per hour) of carteolol. The plasma carteolol level was determined by
the gas chromatography negative-ion chemical ionization mass spectrometric
method. The ONH blood flow was determined by the hydrogen clearance method.
RESULTS: The plasma level of carteolol after a 3-week instillation was 5.55
ng/mL, and a continuous intravenous injection (5 microg/kg per hour) led to
approximately the same plasma level. The continuous intravenous infusion of 5
microg/kg per hour of carteolol significantly increased the ONH blood flow
compared to the controls from 30 minutes to 2 hours after the beginning of the
infusion (n = 10). The mean blood pressure and intraocular pressure (n = 6) were
not significantly changed during the continuous intravenous infusion of
carteolol. CONCLUSIONS: These results suggest that the plasma carteolol level in
rabbits after long-term instillation can increase the ONH blood flow. We conclude
that the increase resulted from a reduction in the vascular resistance in the
ONH.
PMID- 10672878
TI - Alterations of the electroretinogram by intravitreal kainic acid in the rat.
AB - PURPOSE: To relate the electrophysiological changes in the retina induced by the
excitatory neurotoxin, kainic acid (KA), to its receptor sites in the rat.
METHODS: Fifty-five Wistar rats were injected intravitreally with 100, 50, 25,
12.5, 6.25, 3.12, or 1.56 nmol of KA. The electroretinograms (ERGs) including
oscillatory potentials (OPs) elicited by a series of increasing intensities were
recorded before, and 6 hours, 1 day, 1 week, and 1 month after the injection of
KA. RESULTS: After KA injection, the a-waves showed no significant change at all
intensity levels (P > .05), but the amplitudes and implicit times of the b-wave
were significantly altered. The abolition of the b-wave by KA resulted in a
negative response, which decreased progressively with time. The implicit times of
the b-wave showed a marked prolongation after injection of 100 nmol of KA (P <
.01). The OPs disappeared at the KA dose of 6.25 nmol and higher; doses of 1.56
to 3.12 nmol of KA depressed the Ops. CONCLUSIONS: We conclude that KA altered
the above-mentioned ERG components in a dose-dependent manner. These alterations
of the ERG can be explained by alterations of neurons in the inner retinal
layers.
PMID- 10672880
TI - Sicca syndrome and HTLV-I-associated myelopathy/tropical spastic paraparesis.
AB - PURPOSE: The objective of this study is to describe the clinical and
immunological aspects observed in patients with both human T-cell lymphotropic
virus type I-associated myelopathy/tropical spastic paraparesis and ocular
dryness. METHODS: In 15 such patients, clinical and biological examinations
completed with a biopsy of secondary salivary glands were performed to assess the
etiology of the ocular dryness. RESULTS: Histological study of the biopsy
specimens indicated that 80% of the patients had grade 3 or grade 4 lesions,
according to the Chisholm scale. Polyclonal hypergammaglobulinemia was found in
60% of patients and lymphocytic alveolitis in 80%. Three patients had past
medical history of chronic uveitis. CONCLUSIONS: All findings in these patients
were compatible with Sjogren's syndrome; however, no immunological disorders
characteristic of the syndrome were found. Tests for antinuclear antibodies and
rheumatoid factor proved negative in all cases.
PMID- 10672879
TI - Ocular surface management in corneal transplantation, a review.
AB - PURPOSE: To discuss the importance of ocular surface management in corneal
transplantation, especially in limbal transplantation. METHODS: Since the corneal
epithelium is not completely recovered after corneal transplantation, meticulous
attention should be paid to the ocular surface to prevent infection and
rejection, which are the major causes of corneal transplantation failure.
Preoperative evaluations of the ocular surface should be carried out, followed by
appropriate surgical procedures, depending on the condition of each patient.
Vigorous immunosuppressive measures should be taken after surgery. RESULTS: In
both case reports presented in this study, each patient underwent successful
surgery and his condition was controlled by medication suited to his needs.
CONCLUSIONS: For those patients with stem cell deficiency, limbal
transplantation, possibly with the use of autologous serum drops, should be
considered to reconstruct and maintain the ocular surface. Ocular surface
management is necessary for the success of corneal transplantation, especially
for limbal transplantation.
PMID- 10672881
TI - Long-term follow-up of excimer laser phototherapeutic keratectomy.
AB - PURPOSE: To evaluate long-term follow-up results of excimer laser
phototherapeutic keratectomy (PTK) in a Japanese population. METHODS: Twenty-six
patients (31 eyes) with corneal opacity were treated with excimer laser PTK.
Preoperative diagnoses included 16 eyes with band keratopathy, 10 with granular
dystrophy, and 5 with corneal scar. Mean postoperative follow-up was 27 months.
RESULTS: Corneal opacity was reduced in all patients. At postoperative month 12,
best spectacle-corrected visual acuity (BSCVA) improved from the preoperative
level in 22 eyes of 28 eyes, did not change in 3 eyes, and declined in 3 eyes.
BSCVA at month 24 was better than the preoperative acuity in 17 eyes of 23 eyes,
similar in 1 eye, and worse in 5 eyes. Eyes with granular dystrophy showed
significantly better BSCVA improvement than those with band keratopathy. A
hyperopic shift of +1.0 diopter or more occurred in 14 eyes of 28 eyes at month
12 and in 12 eyes of 23 eyes at month 24. No serious adverse effects were
encountered during the 3-year follow-up period. CONCLUSIONS: Excimer laser PTK is
a safe and effective procedure for the treatment of Japanese patients with
superficial corneal opacity.
PMID- 10672882
TI - Therapeutic keratoplasty using preserved corneas from keratoconus eyes.
AB - PURPOSE: To report and discuss cases of lamellar keratoplasty using corneas
obtained during previous penetrating keratoplasty in keratoconus eyes. METHODS:
Corneal buttons were obtained from 7 keratoconus patients and stored in a
preserving solution for 7-60 days (average, 32.4 days) before use. The recipient
eyes comprised recurrent pterygium 3 eyes, primary pterygium 1 eye,
pseudopterygium 1 eye, corneal perforation with iris prolapse due to fungal
corneal ulcer 1 eye, and limbal dermoid 1 eye. RESULTS: The recipient eyes ran
favorable courses in general. Graft rejection developed in 2 eyes and was
successfully treated with topical and systemic corticosteroid. CONCLUSIONS:
Preserved corneas from keratoconus eyes were found useful in therapeutic lamellar
keratoplasty. By this procedure, the current inadequate supply of donor corneas
in eye banks in Japan can be augmented.
PMID- 10672883
TI - Strabismus surgery using the intraoperative adjustable suture method under
anesthesia with propofol.
AB - PURPOSE: To evaluate the feasibility and efficacy of using the intraoperative
adjustable suture method with anesthesia induced by intravenously administered
propofol for strabismus surgery. METHODS: Seven adult patients (mean age, 29.7 +/
18.5 years) with different types of strabismus were enrolled in this study. All
patients underwent full ophthalmological and general medical examinations before
surgery. Surgery was performed after induction of anesthesia using intravenously
administered propofol that was titrated to control consciousness. RESULTS:
Arousal of consciousness was observed at approximately 2 minutes after
discontinuation of the propofol infusion in each case, and the consciousness
level was sufficient to allow accurate cover-uncover testing and intraoperative
adjustment of sutures. Minor complications of nausea in three patients and
vomiting in one patient were noted after surgery. CONCLUSIONS: Strabismus surgery
using the adjustable suture method with propofol intravenous anesthesia appears
to be safe and useful for the treatment of adult strabismus.
PMID- 10672884
TI - Ultrasound biomicroscopy dark room provocative testing: a quantitative method for
estimating anterior chamber angle width.
AB - PURPOSE: To describe a quantitative method for measuring the iridocorneal angle
recess area, and, using this, to evaluate factors associated with appositional
angle-closure during dark room provocative testing using ultrasound biomicroscopy
(UBM). METHODS: All patients (178 patients, 178 eyes) with clinically narrow
angles referred for UBM dark room provocative testing between September 1996 and
March 1998 were enrolled in this study. Images of the inferior quadrant of the
angle taken under standardized dark and light conditions were analyzed. The angle
recess area (ARA) was defined as the triangular area demarcated by the anterior
iris surface, corneal endothelium, and a line perpendicular to the corneal
endothelium drawn from a point 750 microm anterior to the scleral spur to the
iris surface. ARA, and acceleration and gamma-intercept of the linear regression
analysis of the ARA were calculated. In the linear regression formula, y = ax +
b, the acceleration a describes the rate at which the angle widens from the
scleral spur; the y-intercept b describes the distance from the scleral spur to
the iris. RESULTS: Under dark conditions, the angles in 99 patients (55.6%)
showed evidence of appositional angle-closure during testing. ARA (0.11 +/- 0.04
vs. 0.15 +/- 0.05 mm2, P < .0001, Student t-test), acceleration a (0.22 +/- 0.15
vs. 0.26 +/- 0.17, P = .068), and y-intercept b (66 +/- 46 vs. 92 +/- 47 microm,
P = .0003) were smaller in eyes that were occluded. In the eyes that were not
occluded, y-intercept b showed no significant difference between light and dark
conditions (P = .1, paired t-test), while acceleration a did (P < .0001). In the
eyes that were occluded, both decreased significantly under dark conditions (P <
.0001). CONCLUSIONS The ARA linear regression formula provides useful
quantitative information about angle recess anatomy. The more posterior the iris
insertion on the ciliary face, the less likely the provocative test will be
positive.
PMID- 10672885
TI - Pigmentation on anterior chamber angle in eyes of patients with atopic
dermatitis.
AB - PURPOSE: To evaluate pigmentation on the anterior chamber angle in patients with
atopic dermatitis. METHODS: This study includes 61 patients suffering from atopic
dermatitis who visited our hospital between 1991 and 1995. Gonioscopy,
cycloscopy, and fundus examinations with a scleral depressor were performed on
every patient during the initial visit, and were repeated every 6 months.
Pigmentation on the anterior chamber angle was classified according to Scheie.
RESULTS: The pigmentation on the anterior chamber angle at the initial visit was
evaluated as grade 0 (15 eyes), grade 1 (81 eyes), grade 2 (21 eyes), and grade 3
(5 eyes). Retinal detachment was found in 9 eyes of the 26 eyes with grade 2 or 3
pigmentation, but in only one of the 96 eyes with grade 0 or 1. The pigmentation
on the anterior chamber angle correlated significantly with the incidence of
retinal detachment (P < .0001). Causative breaks were found in the peripheral
retina or ciliary epithelium in all eyes. CONCLUSIONS: Moderate to dense
pigmentation on the anterior chamber angle in patients with atopic dermatitis
seems to be a sign of breaks in the retina or ciliary epithelium, and the fundus
of these patients should be examined carefully for signs of retinal detachment.
PMID- 10672886
TI - Prevalence of normal-tension glaucoma and primary open-angle glaucoma in patients
with collagen diseases.
AB - PURPOSE: To investigate the prevalence of normal-tension glaucoma (NTG) and
primary open-angle glaucoma (POAG) in patients with collagen diseases and
determine whether an immunocompromised condition is present in a subset of
glaucoma patients. METHODS: Three glaucoma specialists prospectively examined
patients with collagen diseases. The diagnostic process included applanation
tonometry, slit-lamp examination, gonioscopy, direct ophthalmoscopy, and
automated static perimetry. Twenty-four-hour intraocular pressure monitoring was
done when necessary. Using the results of a population-based survey conducted in
Japan, we calculated an expected number of cases of NTG and POAG, and compared
these with the actual number of cases. RESULTS: Of the 153 patients with collagen
diseases examined, we found 6 patients with NTG and 2 patients with POAG. Of
these 8 patients, 2 with progressive systemic sclerosis (PSS), one with NTG, and
the other, POAG, had a history of being on systemic steroidal therapy. The
prevalence of NTG and POAG was significantly higher in women patients having
collagen diseases as compared with normal women (P = .027). CONCLUSION: Women
patients with collagen diseases are highly susceptible to NTG and POAG.
PMID- 10672887
TI - Vitreous changes after treatment of retinopathy of prematurity.
AB - PURPOSE: To investigate the vitreous findings in patients with cicatricial
retinopathy of prematurity (ROP) who underwent retinal cryopexy and/or
photocoagulation during the acute phase of the disease. METHODS: Vitreous
findings were evaluated in 15 patients (29 eyes) with cicatricial ROP by slit
lamp biomicroscopy and indirect ophthalmoscopy. RESULTS: The ocular examination
revealed that all eyes had extensive vitreous liquefaction that affected a large
segment of the vitreous. A great deal of fibrillar condensation of the vitreous
was present in membrane-like vitreous fibers that traversed the vitreous cavity
to the periphery of the degenerating retina. These vitreous changes were most
marked in the areas in which retinal cryopexy and/or photocoagulation had been
performed. Despite advanced liquefaction, the posterior cortical vitreous was not
separated from the retina in any eyes. CONCLUSION: In eyes with ROP that
underwent retinal cryopexy and/or photocoagulation during the acute phase of the
disease, the vitreous was abnormal, which may contribute to vitreoretinal
traction that eventually leads to retinal breaks and detachment.
PMID- 10672888
TI - Importance of fluorescein angiographic study in evaluating early retinal changes
in Takayasu disease.
AB - PURPOSE: To determine the usefulness of fluorescein angiography in studying
Takayasu disease. METHODS: We examined 31 eyes in 16 patients with Takayasu
disease using indirect ophthalmoscopy, color photography, and fluorescein
angiography. Ophthalmoscopic and fluorescein angiographic findings were compared.
RESULTS: Fluorescein angiography revealed no additional retinal changes in 10
eyes that had no retinal vein dilatation as seen by indirect ophthalmoscopy.
Seven (33%) of 21 eyes that had dilated retinal veins also had additional
abnormal findings, such as microaneurysms, arteriovenous shunts, retinal
neovascularization, and avascular areas. Some differences in grading the stages
of retinopathy were noted with these newly found retinal changes, as compared
with the classifications determined by ophthalmoscopy alone. CONCLUSIONS: In
Takayasu disease, studying the fundus of patients with fluorescein angiography is
particularly important in correctly classifying the stages of retinopathy when
the retinal vein appears dilated in ophthalmoscopic observation.
PMID- 10672889
TI - White thread-like retinal arterioles associated with antiphospholipid antibody
syndrome.
AB - BACKGROUND: Report of 2 patients with antiphospholipid antibody syndrome (APS)
who had elevated anti-beta2-glycoprotein I antibodies and showed white thread
like retinal arterioles. CASES: A complete ophthalmological examination was
conducted on 2 patients who presented with blurred or distorted vision.
Fluorescein angiography was used to examine the integrity of the retinal
circulatory system. Laboratory blood studies were conducted. OBSERVATIONS: In
both patients, some of the major retinal arterioles appeared white and had a
thread-like appearance. Fluorescein angiography demonstrated progressive
occlusion or stenosis of these major arterioles with extensive insufficiency of
the regional capillary bed. Patient 2 had systemic lupus erythematosus and was
treated with oral corticosteroid and aspirin. Recanalization occurred during a 3
year follow-up in one of the patients. CONCLUSIONS: APS should be considered in
cases of white thread-like retinal arterioles. Occlusion of the retinal
arterioles in APS may be progressive and responsible for the chronic hypoxia of
the retina.
PMID- 10672890
TI - The results of serial dynamic enhanced computed tomography in patients with
carotid-cavernous sinus fistulas.
AB - PURPOSE: To assess serial dynamic enhanced computed tomography (serial DE-CT) as
a diagnostic tool for carotid-cavernous sinus fistula (CCF). METHODS: Serial DE
CT was performed in seven patients (ages 31-74) with CCF. Contrast material was
injected intravenously at a dose of 60 mL with an injection speed of 4 mL per
second. Serial axial images of the cavernous sinus were undertaken every 3
seconds using a helical computed tomography system. This relatively low-risk
technique provides direct evidence of the arteriovenous shunt in the cavernous
sinus. RESULTS: In early imaging after the injection, enhancement of the
cavernous sinus on the side of the CCF was noted at the arterial phase in all
patients, whereas early enhancement of the cavernous sinus was not observed on
the contralateral uninvolved side. CONCLUSIONS: These findings suggest the
usefulness of serial DE-CT as a diagnostic tool for the initial diagnosis of both
high- and low-flow CCFs.
PMID- 10672891
TI - Iodine supplementation: benefits outweigh risks.
AB - In 1990, iodine deficiency affected almost one-third of the world population and
was the greatest single cause of preventable brain damage and mental retardation.
Following a resolution adopted by the World Summit for Children in 1990. major
programmes of iodine supplementation were implemented by the governments of the
affected countries with the support of major donors. Iodisation of salt was
recognised as the method of choice. Nine years later, by April 1999, 75% of the
affected countries had legislation on salt iodisation and 68% of the affected
populations had access to iodised salt. The prevalence of iodine deficiency
disorders decreased drastically in most countries and the deficiency disappeared
completely in some such as Peru. This result constitutes a public heath success
unprecedented with a non-infectious disease. However, occasional adverse effects
occurred. The principle effect is iodine-induced hyperthyroidism which occurs
essentially in older people with autonomous nodular goitres, especially following
iodine intake that is too rapid and of too massive an increment. The incidence of
the disorder is usually low and reverts spontaneously to the background rate of
hyperthyroidism or even below this rate after 1 to 10 years of iodine
supplementation. The possible occurrence of iodine-induced thyroiditis in
susceptible individuals has not been clearly demonstrated by large
epidemiological surveys. Iodine supplementation is followed by an increased
prevalence of occult papillary carcinoma of the thyroid discovered at autopsy but
the prognosis of thyroid cancer is improved due to a shift towards differentiated
forms of thyroid cancer that are diagnosed at earlier stages. Iodine-induced
hyperthyroidism and other adverse effects can be almost entirely avoided by
adequate and sustained quality control and monitoring of iodine supplementation
which should also confirm adequate iodine intake. Available evidence clearly
confirms that the benefits of correcting iodine deficiency far outweigh the risks
of iodine supplementation.
PMID- 10672892
TI - Use of routine healthcare data in safe and cost-effective drug use.
AB - Routine healthcare data is becoming widely available, usually as a result of
administrative systems. Other related data are also often available, such as
biochemistry results, mortality data, and sometimes prescribing data. These
records are often linked via a common identification system or by probability
matching techniques. These data sources offer many opportunities to undertake
research, and where prescription data are recorded and linked, the facility to
research the outcome of drug use often exists. There are now a number of research
agencies around the world that use these large routine data sources to undertake
drug safety and outcome studies. The purpose of this commentary is to describe
some of the history behind the development of these systems, illustrate some of
their uses with respect to postmarketing drug safety and to other healthcare
research objectives. The review then describes the data sources necessary to
develop a system that would offer an optimal system to undertake a range of
studies, including population drug safety surveillance. There are both positive
and negative considerations when using routine data. On the positive side, these
data come from 'real life' experiences and not from the clinical trial situation.
On the other hand, there are important biases to be aware of such as confounding
by indication. On the whole, it is argued that large databases originating from
routine healthcare procedures have an important role to play in the cost
effective prescription drug use in the postmarketing setting. These systems
cannot replace other methods of drug safety evaluation but they do offer an
important adjunct to spontaneous reporting systems.
PMID- 10672893
TI - Patient-oriented strategies for the prevention of drug interactions.
AB - Drug interactions are a common and serious problem arising from polypharmacy.
Strategies to reduce the likelihood of the co-prescription of hazardous drug
combinations are likely to enhance the quality of care provided for patients
requiring polypharmacotherapy. Drugs for which patient-oriented information
strategies may decrease the likelihood of drug interactions tend to be those of
low therapeutic index. and have interaction potential with other drugs commonly
prescribed or available without prescription.
PMID- 10672894
TI - Corticosteroid-induced adverse psychiatric effects: incidence, diagnosis and
management.
AB - Reports of corticosteroid-induced adverse psychiatric effects began to appear in
the literature soon after the introduction of these medications in the 1950s.
Unfortunately, early studies relied on informal classification and measurement
procedures and tended to utilise nonspecific descriptive terminology (such as
steroid psychosis'). A growing number of contemporary investigations have begun
to address these problems. However, the literature remains surprisingly
undeveloped from a pharmacoepidemiological perspective, consisting largely of
case reports and case series. The objective of this review is to summarise
published data concerning corticosteroid-induced adverse psychiatric effects. A
clinical perspective will be adopted since opportunities to minimise the impact
of corticosteroid-induced adverse effects tend to present themselves most readily
within the sphere of clinical management. Some of the psychiatric adverse effects
of corticosteroids are mild, and not necessarily clinically significant. However,
several serious psychiatric syndromes can be caused by corticosteroids: substance
induced mood disorders (with depressive, manic and mixed features), substance
induced psychotic disorders and delirium. While certain clinical groups may be at
greater risk of corticosteroid-induced adverse psychiatric effects,
corticosteroid-induced psychiatric toxicity is remarkably unpredictable. The
literature regarding prevention and treatment of corticosteroid-induced adverse
psychiatric effects is poorly developed. As a result, the emphasis of this review
is on clinical and epidemiological evidence linking specific adverse effects to
corticosteroid medications. However, clinical reports do provide some practical
guidance for prevention and treatment, and these are summarised as well. A
variety of pharmacological strategies for treatment and prevention have been
proposed. Education and support also appear to be important, and perhaps
neglected.
PMID- 10672895
TI - Utility of acetylcysteine in treating poisonings and adverse drug reactions.
AB - As recognition of the role of free radicals and reactive toxins in the
pathogenesis of disease, poisoning, and adverse drug reactions has evolved,
interest in the use of acetylcysteine as a modulator of these effects has
steadily increased in recent years. Acetylcysteine is commonly thought to serve
as a glutathione precursor and consequently can increase or sustain intracellular
glutathione which scavenges reactive oxygen species caused by toxins or
subsequent tissue injury. At least 10 additional mechanisms of action for
acetylcysteine have been demonstrated in various laboratory models, but a
unifying framework of its actions is still to be proposed. This paper reviews the
current experimental and therapeutic status of acetylcysteine for the treatment
of poisonings and adverse drug reactions. Of the 45 potential uses of
acetylcysteine that were identified for the treatment of poisonings or adverse
drug reactions, 14 of the toxic effects have little support for its use while
promising results have been demonstrated for 27 toxicities. Currently, treatment
of acute paracetamol (acetaminophen) poisoning is the only widely accepted
clinical indication for acetylcysteine as a treatment for poisoning or adverse
drug reactions. In many clinical situations acetylcysteine is used empirically
utilising modifications of dosage regimens employed for paracetamol poisoning.
Often it is difficult to determine the benefit of therapy with acetylcysteine
owing to the nature of the toxicity being treated, the use of other therapies,
the presence of comorbid conditions, and the small number of patients studied.
The diverse and positive nature of the investigations suggest that there is
considerable promise in acetylcysteine as a research tool and pharmacological
agent.
PMID- 10672896
TI - Managing the adverse effects of interferon-beta therapy in multiple sclerosis.
AB - Interferon-beta is an established therapy in relapsing-remitting multiple
sclerosis. Recently, it has also been shown that interferon-beta-1b is effective
in secondary progressive multiple sclerosis. However, adverse effects of
interferon-beta treatment are common, particularly during the first weeks of
treatment, and are a major concern. Flu-like symptoms, injection site reactions
and laboratory abnormalities are the most common adverse effects, and may result
in reduced compliance or even discontinuation of treatment in a number of
patients. Therefore, efforts to minimise these reactions, e.g. appropriate
comedication with analgesic/antipyretic drugs, use of correct preparation and
injection technique and sometimes modification of the dosage of interferon-beta,
are of considerable importance. This article provides an overview of the
management of clinically relevant adverse effects related to treatment with
interferon-beta, based on a literature review and personal experience. Essential
aspects of patient information are also stressed. If these recommendations are
followed, adverse effects related to interferon-beta may be substantially reduced
in the majority of patients.
PMID- 10672897
TI - Incidence and costs of adverse drug reactions during hospitalisation:
computerised monitoring versus stimulated spontaneous reporting.
AB - OBJECTIVE: To implement a computer-based adverse drug reaction monitoring system
and compare its results with those of stimulated spontaneous reporting, and to
assess the excess lengths of stay and costs of patients with verified adverse
drug reactions. DESIGN: A prospective cohort study was used to assess the
efficacy of computer-based monitoring, and case-matching was used to assess
excess length of stay and costs. SETTING: This was a study of all patients
admitted to a medical ward of a university hospital in Germany between June and
December 1997. PATIENTS AND PARTICIPANTS: 379 patients were included, most of
whom had infectious, gastrointestinal or liver diseases, or sleep apnoea
syndrome. Patients admitted because of adverse drug reactions were excluded.
METHODS: All automatically generated laboratory signals and reports were
evaluated by a team consisting of a clinical pharmacologist, a clinician and a
pharmacist for their likelihood of being an adverse drug reaction. They were
classified by severity and causality. For verified adverse drug reactions,
control patients with similar primary diagnosis, age, gender and time of
admission but without adverse drug reactions were matched to the cases in order
to assess the excess length of hospitalisation caused by an adverse drug
reaction. RESULTS: Adverse drug reactions were detected in 12% of patients by the
computer-based monitoring system and stimulated spontaneous reporting together
(46 adverse reactions in 45 patients) during 1718 treatment days. Computer-based
monitoring identified adverse drug reactions in 34 cases, and stimulated
spontaneous reporting in 17 cases. Only 5 adverse drug reactions were detected by
both methods. The relative sensitivity of computer-based monitoring was 74%
(relative specificity 75%), and that of stimulated spontaneous reporting was 37%
(relative specificity 98%). All 3 serious adverse drug reactions were detected by
computer-based monitoring, but only 2 out of the 3 were detected by stimulated
spontaneous reporting. The percentage of automatically generated laboratory
signals associated with an adverse drug reaction (positive predictive value) was
13%. The mean excess length of stay was 3.5 days per adverse drug reaction. 48%
of adverse reactions were predictable and detected solely by computer-based
monitoring. Therefore, the potential for savings on this ward from the
introduction of computer-based monitoring can be calculated as EUR56 200/year
($US59 600/year) [ 1999 values]. CONCLUSION: Computer monitoring is an effective
method for improving the detection of adverse drug reactions in inpatients. The
excess length of stay and costs caused by adverse drug reactions are substantial
and might be considerably reduced by earlier detection.
PMID- 10672898
TI - Selective loss of the transforming growth factor-beta apoptotic signaling pathway
in mutant NRP-154 rat prostatic epithelial cells.
AB - Retroviral insertional mutagenesis was used to select mutant NRP-154 rat prostate
carcinoma cells resistant to transforming growth factor (TGF)-beta-induced cell
death. Similar to the parental cells, a mutant clone, M-NRP1, expressed TGF-beta
receptors and was still responsive to induction both of direct target genes by
TGF-beta and of apoptosis by staurosporine or okadaic acid. In contrast,
indicators of cell growth, strongly suppressed by TGF-beta in the parental cells,
were unaffected in M-NRP1 cells. M-NRP1 cells overexpress the antiapoptotic
protein, Bcl-xL, and show dysregulated expression and localization of a protein
related to a novel human septin, ARTS (designation of apoptotic response to TGF
beta signals), cloned by homology to an exonic sequence flanked by the viral long
terminal repeats in M-NRP1 cells and shown to make cells competent to undergo
apoptosis in response to TGF-beta. We propose that ARTS might operate within the
same apoptotic pathway as Bcl-xL and that M-NRP1 cells could serve as a useful
model for characterization of this pathway.
PMID- 10672899
TI - Molecular cloning of a novel retinoic acid-responsive gene, HA1R-62, which is
also up-regulated in Hoxa-1-overexpressing cells.
AB - Using a PCR-based cDNA subtractive hybridization method (L. Diatchenko et al.,
Proc. Natl. Acad. Sci. USA, 93: 6025-6030, 1996), we cloned a cDNA fragment of a
novel gene that is highly expressed in F9-10; F9-10 is an F9 teratocarcinoma stem
cell line that expresses high levels of exogenous Hoxa-1 mRNA and protein in
comparison to F9 wild-type stem cells, which do not express endogenous Hoxa-1
mRNA in the absence of retinoic acid (RA). Rapid amplification of cDNA ends was
used to clone the full-length cDNA of this gene, designated HA1R-62 (Hoxa1
regulated-62). We have shown that HA1R-62 is also a RA-responsive gene and that
it is expressed (mRNA size, approximately 4.3 kb) in adult mouse thymus, lung,
kidney, and ovary as well as in 12.5-day mouse embryos. DNA sequence analysis and
in vitro translation experiments have shown that HA1R-62 encodes a protein with a
molecular mass of approximately 26 kDa. Elucidation of the function of the HA1R
62 gene product will provide new insights into the functions of RA and homeobox
genes.
PMID- 10672900
TI - Thrombin causes pseudopod detachment via a pathway involving cytosolic
phospholipase A2 and 12/15-lipoxygenase products.
AB - Thrombin causes rapid pseudopod detachment and shortening in Dunning rat
prostatic carcinoma (MAT-Lu) cells. As seen by interference reflection microscopy
and by immunofluorescence analysis with antibodies to paxillin and talin, the
primary event is disassembly of adhesion sites. Biochemically, thrombin is a
potent activator of cytosolic phospholipase A2 and increases eicosanoid
production in these cells. The pseudopod effects are blocked by lipoxygenase (but
not cyclooxygenase) inhibitors. Arachidonic acid and 12(S)
hydroxyeicosatetraenoic acid or 15(S)-hydroxyeicosatetraenoic acid mimic the
thrombin effect. We conclude that in certain cancer cells, thrombin is a
pseudopod repellent that exerts its effect via a cascade involving cytosolic
phospholipase A2, 12/15-lipoxygenase, and 12(S)- and/or 15(S)
hydroxyeicosatetraenoic acid.
PMID- 10672901
TI - Polyoma virus middle T and small t antigens cooperate to antagonize p53-induced
cell cycle arrest and apoptosis.
AB - Wild-type p53 triggers two distinct biological responses, cell cycle arrest and
apoptosis. Several small DNA tumor viruses encode proteins that bind p53 and thus
block the function of p53. This probably reflects the need of these viruses to
prevent p53-induced cell cycle arrest and apoptosis to allow viral DNA
replication. Unlike SV40 large T, polyoma virus large T does not bind p53, and it
is still unclear how polyoma virus blocks p53 function. To address this question,
we transfected polyoma virus middle T or small t alone or middle T and small t
together into J3D mouse T-lymphoma cells carrying temperature-sensitive p53 (ts
p53). Induction of wild-type p53 by temperature shift to 32 degrees C triggered
both G1 cell cycle arrest and apoptosis in parental J3D-ts p53 cells. In
contrast, J3D-ts p53 cells coexpressing middle T and small t showed only a weak
G1 cell cycle arrest response after induction of wild-type p53 at 32 degrees C.
Fluorescence-activated cell sorter analysis revealed that nearly half of the
middle T-expressing cells, 30% of the small t-expressing cells, and a majority of
the cells coexpressing middle T and small t were resistant to p53-induced
apoptosis. The phosphatidylinositol 3-kinase inhibitor wortmannin partially
abrogated the protective effect of middle T but not small t on p53-induced
apoptosis, indicating that middle T prevents p53-induced apoptosis through the
phosphatidylinositol 3-kinase signal transduction pathway. Our results thus
establish a mechanism for polyoma virus-mediated inhibition of p53 function.
PMID- 10672902
TI - Phosphospecific antibodies reveal focal adhesion kinase activation loop
phosphorylation in nascent and mature focal adhesions and requirement for the
autophosphorylation site.
AB - Focal adhesion kinase (FAK) is a key signaling molecule regulating cellular
responses to integrin-mediated adhesion. Integrin engagement promotes FAK
phosphorylation at multiple sites to achieve full FAK activation. Phosphorylation
of FAK Tyr-397 creates a binding site for Src-family kinases, and phosphorylation
of FAK Tyr-576/Tyr-577 in the kinase domain activation loop enhances catalytic
activity. Using novel phosphospecific antibody reagents, we show that FAK
activation loop phosphorylation is significantly elevated in cells expressing
activated Src and is an early event following cell adhesion to fibronectin. In
both cases, this regulation is largely dependent on Tyr-397. We also show that
the FAK activation loop tyrosines are required for maximal Tyr-397
phosphorylation. Finally, immunostaining analyses revealed that tyrosine
phosphorylated forms of FAK are present in both newly forming and mature focal
adhesions. Our findings support a model for reciprocal activation of FAK and Src
family kinases and suggest that FAK/Src signaling may occur during both focal
adhesion assembly and turnover.
PMID- 10672903
TI - Nonapoptotic cell death associated with S-phase arrest of prostate cancer cells
via the peroxisome proliferator-activated receptor gamma ligand, 15-deoxy
delta12,14-prostaglandin J2.
AB - 15-Deoxy-delta12,14-prostaglandin J2 (15d-PGJ2) is a highly specific activator of
the peroxisome proliferator-activated receptor gamma (PPAR-gamma). We
investigated the effect of 15d-PGJ2 on three human prostate cancer cell lines,
LNCaP, DU145, and PC-3. Western blotting demonstrated that PPAR-gamma1 is
expressed predominantly in untreated prostate cancer cells. Treatment with 15d
PGJ2 caused an increase in the expression of PPAR-gamma2, whereas PPAR-gamma1
remained at basal levels. PPARs alpha and beta were not detected in these cells.
Lack of lipid accumulation, increase in CCAAT/enhancer binding proteins (C/EBPs),
or expression of aP2 mRNA indicated that adipocytic differentiation is not
induced in these cells by 15d-PGJ2. 15d-PGJ2 and other PPAR-gamma activators
induced cell death in all three cell lines at concentrations as low as 2.5 microM
(similar to the Kd of PPAR-gamma for this ligand), coinciding with an
accumulation of cells in the S-phase of the cell cycle. Activators for PPAR-alpha
and beta did not induce cell death. Staining with trypan blue and propidium
iodide suggested that, although the plasma membrane appears intact by electron
microscopy, disturbances are evident as early as 2 h after treatment.
Mitochondrial transmembrane potentials are significantly reduced by 15d-PGJ2
treatment. In addition, treatment with 15d-PGJ2 resulted in cytoplasmic changes,
which are indicative of type 2 (autophagic), nonapoptotic programmed cell death.
PMID- 10672904
TI - Inhibition of RNA polymerase I transcription in differentiated myeloid leukemia
cells by inactivation of selectivity factor 1.
AB - Transcription by RNA polymerase I (pol I) regulates the rate of ribosome
biogenesis and the biosynthetic potential of the cell; therefore, it plays an
important role in the control of cell growth. Differentiation of the human
promyelocytic leukemic cell line U937 is accompanied by drastic decreases in pol
I transcriptional activity. We have used cell-free extracts prepared from
undifferentiated and differentiated U937 cells to investigate the molecular
mechanisms responsible for this inhibitory process. Our analysis indicates that
the activity of the TATA binding protein (TBP)/TBP-associated factor (TAF)
complex selectivity factor 1 (SL1), one of the factors required for accurate and
promoter-specific transcription by RNA pol I, is severely repressed in
differentiated U937 cells. Moreover, the reduction in SL1 activity is not a
consequence of a decrease in SL1, because there is no detectable difference in
the abundance of TBP or TAFs before and after U937 cell differentiation. In
conclusion, our results indicate that the selectivity factor SL1 is an important
target for the regulation of pol I transcription during cell differentiation.
PMID- 10672905
TI - Transgenic models as tools for studying the regulation of human renin expression.
AB - Transgenic mice and rats have become popular tools to study the regulation of
gene expression and the consequences of protein over-production. Over the past
decade, numerous transgenic models have been developed to study the mechanisms of
human renin gene expression and the participation of the renin-angiotensin system
in the development of hypertension. Herein we will provide an overview of what
has been learned from the use of transgenic models for studying the human renin
gene.
PMID- 10672906
TI - High fat maintenance diet attenuates hindbrain neuronal response to CCK.
AB - Rats maintained on a high fat diet reduce their food intake less in response to
exogenous cholecystokinin (CCK) than rats maintained on a low fat diet. In
addition, inhibition of gastric emptying by CCK is markedly attenuated in rats
maintained on a high fat diet. Both inhibition of food intake and gastric
emptying by CCK are mediated by sensory fibers in the vagus nerve. These fibers
terminate on dorsal hindbrain neurons of the nucleus of the solitary tract and
area postrema. To determine whether diet-induced changes in the control of
feeding and gastric emptying are accompanied by altered vagal sensory
responsiveness, we examined dorsal hindbrain expression of Fos-like
immunoreactivity (Fos-li) following intraperitoneal CCK injection of rats
maintained on high fat or low fat diets. Following CCK, there were numerous Fos
li nuclei in the area postrema and in the commissural and medial subnuclei of the
nucleus of the solitary tract of rats maintained on a low fat diet. However, Fos
li was absent or rare in the brains of rats maintained on a high fat diet. These
data suggest that the vagal sensory response to exogenous CCK is reduced in rats
maintained on a high fat diet. Our results also are consistent with our previous
findings that CCK-induced reduction of food intake and gastric emptying are both
attenuated in rats maintained on a high fat diet. In addition our results support
the hypothesis that attenuation of CCK-induced inhibition of food intake and
gastric emptying may be due to diet-induced diminution of vagal CCK
responsiveness.
PMID- 10672907
TI - An interaction of opioids and galanin in dorsal horn of the spinal cord in
mononeuropathic rats.
AB - The present study was performed in rats with experimentally induced
mononeuropathy after common sciatic nerve ligation. The hind-paw withdrawal
latencies to thermal and mechanical stimulation were increased significantly
after intrathecal injection of 3 nmol of galanin. The increased hind-paw response
latencies induced by galanin were attenuated by following intrathecal injection
of 22 nmol, but not 11 or 2.75 nmol of the opioid receptor antagonist naloxone.
Further, the increased hind-paw response latencies induced by galanin were
prevented by following intrathecal injection of 10 nmol of mu-opioid receptor
antagonist, beta-funaltrexamine (beta-FNA), but not by 10 nmol of delta-opioid
receptor antagonist, natrindole or 10 nmol of kappa-opioid receptor antagonist,
nor-binaltorphimine (nor-BNI). Intrathecal 10 nmol of beta-FNA alone had no
significant effects on the hind-paw withdrawal responses. These results
demonstrate the existence of a specific interaction between galanin and opioids
in the transmission of presumed nociceptive information in the spinal cord of
mononeuropathic rats. This interaction involves the activation of mu-opioid
receptor.
PMID- 10672908
TI - Release of neuropeptide Y and hemodynamic changes during surgical removal of
human pheochromocytomas.
AB - This study investigates the release of Neuropeptide Y from eight human
pheochromocytomas. Profil immunoreactive Neuropeptide Y (Ir-NPY) levels during
the management of surgery were compared with these of norepinephrine (NE) while
hemodynamics were monitored. Plasma IrNPY and NE levels increased during tumor
manipulation and returned to near normal one hour after operation. However, Ir
NPY levels remained high just after tumor resection while NE levels were
significantly decreased. At tumor manipulation and just after tumor resection,
plasma Ir-NPY levels were correlated with the systemic vascular resistances (SVR)
(r = 0.74; P<0.04 and r = 0.86; P<0.006 respectively). No correlation was found
either between plasma Ir-NPY and NE levels or between plasma NE levels and SVR.
The release of Ir-NPY from tumor tissue, studied by a superfusion method,
exhibited a significant correlation with the plasma Ir-NPY concentrations at the
time of corresponding tumor resection (r = 0.95; P<0.007). Chromatographic
analysis showed that Ir-NPY in plasma and outflow migrate as human NPY (1-36).
These results confirmed that in pheochromocytoma, plasma NPY mainly originates
from the tumor and argue for an important role of NPY in pheochromocytoma
hypertension as indicated by the correlation between the Ir-NPY levels and the
SVR.
PMID- 10672909
TI - GLP-1-analogues resistant to degradation by dipeptidyl-peptidase IV in vitro.
AB - Glucagon-like peptide-1 (GLP-1) stimulates insulin secretion and improves
glycemic control in type 2 diabetes. In serum the peptide is degraded by
dipeptidyl peptidase IV (DPP IV). The resulting short biological half-time limits
the therapeutic use of GLP-1. DPP IV requires an intact alpha-amino-group of the
N-terminal histidine of GLP-1 in order to perform its enzymatic activity.
Therefore, the following GLP- analogues with alterations in the N-terminal
position 1 were synthesized: N-methylated- (N-me-GLP-1), alpha-methylated (alpha
me-GLP-1), desamidated- (desamino-GLP-1) and imidazole-lactic-acid substituted
GLP-1 (imi-GLP-1). All GLP-1 analogues except alpha-me-GLP-1 were hardly degraded
by DPP IV in vitro. The GLP-1 analogues showed receptor affinity and in vitro
biological activity comparable to native GLP-1 in RINm5F cells. GLP-1 receptor
affinity was highest for imi-GLP-1, followed by alpha-me-GLP-1 and N-me-GLP-1.
Only desamino-GLP-1 showed a 15-fold loss of receptor affinity compared to native
GLP-1. All analogues stimulated intracellular cAMP production in RINm5F cells in
concentrations comparable to GLP-1. N-terminal modifications might therefore be
useful in the development of long-acting GLP-1 analogues for type 2 diabetes
therapy.
PMID- 10672910
TI - Gastric submucosal microdialysis: a method to study gastrin- and food-evoked
mobilization of ECL-cell histamine in conscious rats.
AB - Rat stomach ECL cells are rich in histamine and chromogranin A-derived peptides,
such as pancreastatin. Gastrin causes the parietal cells to secrete acid by
flooding them with histamine from the ECL cells. In the past, gastric histamine
release has been studied using anaesthetized, surgically manipulated animals or
isolated gastric mucosa, glands or ECL cells. We monitored gastric histamine
mobilization in intact conscious rats by subjecting them to gastric submucosal
microdialysis. A microdialysis probe was implanted into the submucosa of the acid
producing part of the stomach (day 1). The rats had access to food and water or
were deprived of food (48 h), starting on day 2 after implantation of the probe.
On day 4, the rats received food or gastrin (intravenous infusion), and sampling
of microdialysate commenced. Samples (flow rate 1.2 microl min(-1)) were
collected every 20 or 60 min, and the histamine and pancreastatin concentrations
were determined. The serum gastrin concentration was determined in tail vein
blood. Exogenous gastrin (4-h infusion) raised microdialysate histamine and
pancreastatin dose-dependently. This effect was prevented by gastrin receptor
blockade (YM022). Depletion of ECL-cell histamine by alpha-fluoromethylhistidine,
an irreversible inhibitor of the histamine-forming enzyme, suppressed the gastrin
evoked release of histamine but not that of pancreastatin. Fasting lowered serum
gastrin and microdialysate histamine by 50%, while refeeding raised serum gastrin
and microdialysate histamine and pancreastatin 3-fold. We conclude that histamine
mobilized by gastrin and food intake derives from ECL cells because: 1) Histamine
and pancreastatin were released concomitantly, 2) histamine mobilization
following gastrin or food intake was prevented by gastrin receptor blockade, and
3) mobilization of histamine (but not pancreastatin) was abolished by alpha
fluoromethylhistidine. Hence, gastric submucosal microdialysis allows us to
monitor the mobilization of ECL-cell histamine in intact conscious rats under
various experimental conditions not previously accessible to study. While gastrin
receptor blockade lowered post-prandial release of ECL-cell histamine by about
80%, unilateral vagotomy reduced post-prandial mobilization of ECL-cell histamine
by about 50%. Hence, both gastrin and vagal excitation contribute to the post
prandial release of ECL-cell histamine.
PMID- 10672911
TI - Interaction between brain natriuretic peptide and atrial natriuretic peptide in
caecal circular smooth muscle cells.
AB - Guinea pig caecal circular smooth muscle cells were used to determine whether
brain natriuretic peptide (BNP) can inhibit the contractile response produced by
cholecystokinin-octapeptide (CCK-8). In addition, we examined the effect of an
inhibitor of cAMP-dependent protein kinase, an inhibitor of particulate or
soluble guanylate cyclase, an atrial natriuretic peptide (ANP) antagonist (ANP 1
11), and selective receptor protection on the BNP-induced relaxation of these
muscle cells. The effect of BNP on cAMP formation was also examined. BNP
inhibited the contractile response produced by CCK-8 in a dose-response manner,
with an IC50 value of 8.5 nM, and stimulated the production of cAMP. The
inhibitor of cAMP-dependent protein kinase and the inhibitor of soluble guanylate
cyclase significantly inhibited the relaxation produced by BNP. In contrast, the
inhibitor of particulate guanylate cyclase did not have any significant effect on
the relaxation produced by BNP. ANP 1-11 significantly but partially inhibited
the relaxation produced by BNP. The muscle cells where CCK-8 and ANP binding
sites were protected completely preserved the inhibitory response to ANP, but
partially preserved the inhibitory response to BNP. The muscle cells where CCK-8
and BNP binding sites were protected completely preserved the inhibitory response
to both ANP and BNP. This study demonstrates that BNP induces relaxation of these
muscle cells via both ANP binding sites coupled to soluble guanylate cyclase and
distinct BNP binding sites coupled to adenylate cyclase.
PMID- 10672912
TI - Introduction: aging and the kidney.
PMID- 10672913
TI - The nature of chronic progressive nephropathy in aging rats.
AB - Increases in glomerular size and thickening of the glomerular basement membrane
are constant features that accompany growth and maturation in animals. Yet, some
animals have chronic progressive nephropathy characterized by glomerulosclerosis
and tubulointerstitial fibrosis. In these animals, clinically significant
reductions in glomerular filtration rate may compromise health, particularly when
other renal diseases occur concomitantly. Progressive thickening of the
glomerular basement membrane is accompanied by changes in its composition, which
may be responsible for changes in podocyte morphology and proteinuria. Within the
tubulointerstitium, generalized accumulation of fibronectin and thrombospondin
are accompanied by blood vessel proliferation. Fragility of these blood vessels
with intermittent bleeding may initiate an inflammatory process that leads to
focal areas of tubular atrophy and scarring. The pathogenesis of these lesions is
unknown. Genetic background, sex, and environmental factors influence the tempo
of progressive sclerosis, although these factors are not primary determinants of
this lesion. This review highlights the structural changes that occur in the
kidney with aging. Because the lesions are structurally similar, information
gleaned from studies of aging animals should be relevant to understanding the
loss of renal function that occurs in aging humans.
PMID- 10672914
TI - Biology of renal aging in humans.
AB - Advancing age is usually accompanied by a decline in glomerular filtration rate
and an increased incidence of certain renal and electrolyte disorders. These
include an increased susceptibility to acute renal failure, hypo- and
hypernatremia, hyperkalemia, and hypertension. This report discusses anatomic and
physiological observations related to the aged human kidney and explores the
various theories and postulated mechanisms underlying these changes.
PMID- 10672915
TI - Hypertension in older adults.
AB - Isolated systolic hypertension and combined systolic and diastolic hypertension
are clinical problems affecting significant numbers of older adults (>65 years).
Preventing the complications of hypertension, including stroke and coronary
artery disease, may potentially impact not only an individual's sense of well
being, but also their functional status and ability to live independently in the
community. Despite the increased absolute risk for cardiovascular events
associated with hypertension in older adults compared with younger adults,
significant numbers of individuals remain untreated or inadequately treated.
There is clinical data to show that treating both isolated systolic hypertension
and combined systolic and diastolic hypertension results in a significant
reduction in cardiovascular events in older adults. Although there is a growing
body of literature on treatment of hypertension in the 60- to 80-year-old, the
data on individuals greater than 80 years old is lacking. The challenge becomes
to treat hypertension safely in the presence of multiple medications and other
diseases.
PMID- 10672916
TI - Diabetes in the elderly population.
AB - Type 2 diabetes mellitus has emerged as an important condition of older patients
in which both microvascular and macrovascular complications are a common cause of
morbidity and mortality. In contrast to type 1 diabetes mellitus, this
endocrinopathy is clustered in minority populations and has both strong genetic
and environmental factors that influence disease manifestation. A number of
physiological alterations of glucose metabolism including hepatic overproduction
of glucose, and reduced glucose utilization by peripheral tissues as a result of
insulin resistance contribute to the development of the metabolic manifestations
of this disease. Ultimately, pancreatic failure and reduced insulin secretion
lead to hyperglycemia and the diabetic state. Frequently, many of these metabolic
manifestations, or what has been termed Syndrome X, antecede the development of
overt diabetes by many years. This syndrome is manifest clinically by such
cardiovascular risk factors as hypertension, dyslipidemia, and coagulation
abnormalities. This abnormal metabolic milieu contributes to the high prevalence
of macrovascular complications including coronary artery disease as well as more
generalized atherosclerosis. Microvascular complications have only more recently
been recognized as an important and frequent complication of type 2 diabetes.
Among the elderly and minority populations, this has become the single most
important cause of end-stage renal failure that necessitates renal replacement
therapies. The outcome for these patients on hemodialysis, the modality most
frequently selected, is poor, with the majority of these patients dying of
cardiovascular causes. Unfortunately, interventional strategies to reduce or
prevent the microvascular and macrovascular complications have only recently
received the needed attention and will require considerable effort and resources
to improve the clinical outcomes and life expectancies for these patients.
PMID- 10672917
TI - Renal replacement therapy in the elderly: medical, ethical, and psychosocial
considerations.
AB - As patients over the age of 65 become the fastest growing segment of our treated
end-stage renal disease (ESRD) population, nephrologists and allied healthcare
workers who care for these patients must become well versed in the many issues
specific to this group. Elderly patients contribute the greatest fraction to the
incidence and prevalence of the United States ESRD population. Their life
expectancy is greatly reduced compared with age-matched counterparts from the
general population. Cardiac disease is the leading cause of death. Although renal
transplantation remains the most successful form of renal replacement therapy,
only a small fraction of elderly ESRD patients are transplanted. The renal
research community has made great strides in improving patient outcomes on
dialysis over the last decade in many areas; however, little attention has been
focused on the elderly ESRD patient. The substantial mortality and comorbidity
experienced by this population makes their management an ongoing challenge. Many
unresolved issues remain for elderly ESRD patients in the timing of dialysis
initiation, choice of dialytic therapy, use of renal transplantation, and
management of cardiovascular disease. It is anticipated that future research in
these areas will identify optimal treatment strategies for elderly ESRD patients
starting on dialysis and improve patient outcomes.
PMID- 10672918
TI - Ethical issues in aging and renal disease.
AB - The incidence of elderly patients reaching end-stage renal disease (ESRD) and
requiring renal replacement is increasing. Better medical care is helping
patients live longer but, at the same time, is raising ethical questions.
Treatment decisions for ESRD patients present a forum for the consideration of
ethical questions surrounding the issues of scarce health care resource
allocation and the withholding or withdrawal of life-sustaining treatment. As
background for the consideration of ethical issues in ESRD patients, the quality
of life they experience and what they may expect as death approaches also are
discussed.
PMID- 10672919
TI - Successful aging and disease prevention.
AB - Substantial increases in the relative and absolute number of older persons in our
society pose a challenge for biology, social and behavioral science, and
medicine. Successful aging is multidimensional, encompassing the avoidance of
disease and disability, the maintenance of high physical and cognitive function,
and sustained engagement in social and productive activities. Research has
identified factors predictive of success in these critical domains. Two
additional research domains, resilience and wisdom, are suggested, and a national
initiative in health promotion and disease prevention is proposed.
PMID- 10672920
TI - Caring for the nursing home resident on dialysis: a search for solutions.
AB - The need for nursing home placement of dialysis patients continues to escalate.
Creative solutions are necessary to insure placement availability and optimal
care of residents on dialysis once admitted. Communication between the nursing
home and dialysis unit staff is key to reducing barriers to placement. The
National Kidney Foundation of Michigan is currently intervening through the
Nursing Home Manual to enhance training and communication.
PMID- 10672921
TI - Educating community providers changes beliefs towards caring for the ESRD
patient.
AB - End-Stage Renal Disease (ESRD) patients often have comorbid conditions
necessitating the involvement of multiple professionals from various settings
such as dialysis centers, primary care and skilled nursing facilities, group
homes, mental health, rehabilitation, and home health care agencies. This
provision of services can be fragmented and may be impeded by a lack of knowledge
regarding the specific needs of renal patients. "A Caring Community: An
Integrated Approach to Meeting the Needs of the Renal Patient" is a
multidisciplinary professional education program which has been shown to change
the beliefs of community providers regarding ESRD patients. Program attendee
survey responses were measured in accordance with a modified Health Belief Model.
This report identifies the need and demand for interdisciplinary renal education
and the potential benefits of such a community-wide intervention and makes
recommendations for future research.
PMID- 10672922
TI - Genetically engineered transgenic plants with the domain 1 sequence of tobacco
mosaic virus 126 kDa protein gene are completely resistant to viral infection.
AB - In many plant RNA viruses, Domains 1, 2 and 3 are conserved in replicase
proteins. In order to examine the interference of viral replication by the Domain
1 sequence, we generated transgenic plants transformed with DNA corresponding to
the Domain 1 sequence of the TMV 126 kDa protein. This DNA sequence includes the
TMV RNA from nucleotides 1 to 2,149, which comprises both the 5'-untranslated and
methyl transferase region. The transgenic plants obtained showed complete
resistance to TMV infection. The presence of the Domain 1 sequence in the plants
completely prevented local necrosis in Nicotiana tabacum cv. Xanthi nc, and any
systemic development of symptoms in Nicotiana tabacum Xanthi upon TMV
inoculation. Most transgenic plants sustained the conferred resistance even under
TMV inoculum concentrations up to as high as 1,000 microg/ml. To detect any
accumulation of TMV coat protein or viral RNA in infected transgenic plants,
immunochemical tests and Northern blot analyses were carried out. Neither viral
RNA or coat protein was detectable in the systemic leaves of the completely
resistant transgenic plants, whereas they were accumulated in large quantities in
all of the control plants. Because of the conservation of Domain 1 in many plant
RNA viruses, the acquisition of resistance to virus infection using the Domain 1
sequence appears to be a very effective strategy for breeding of viral resistant
plants.
PMID- 10672923
TI - Ectopic expression of tobacco MADS genes modulates flowering time and plant
architecture.
AB - MADS genes encode regulatory factors that are involved in various developmental
steps of the plant life cycle. During flower development, they regulate the early
step of specifying floral meristem identity as well as the later step of
determining the fate of floral organ primordia. Here, we report the isolation of
two cDNA clones, NsMADS2 and NsMADS3, from a long-day tobacco species, Nicotiana
sylvestris, which encode MADS domain-containing proteins. The NsMADS2 amino acid
sequence showed 66% identity to SQUA and 64% to AP1. NsMADS3 showed a high degree
of amino acid identity with FBP2 (98%), DEFH 72 (89%), DEFH 200 (88%), and AGL9
(76%). RNA blot analyses of NsMADS2 and NsMADS3 revealed that both transcripts
were present in floral organs, but not in vegetative organs such as the leaf,
root, stem, and 10 d old seedlings. The NsMADS2 transcript was localized in all
four whorls and the NsMADS3 transcript was restricted in the three inner whorls
of floral organs. The ectopic expression of NsMADS2 using the CaMV 35S promoter
caused early flowering and lengthened internode length in transgenic tobacco
plants. The ectopic expression of NsMADS3 also caused early flowering phenotype
in transgenic tobacco plants, but the plants exhibited reduced apical dominance.
Possible implications of these results in relation to the functions of NsMADS2
and NsMADS3 are discussed.
PMID- 10672924
TI - Generation of self-antigen reactive, anti-urocortin specific antibodies by
immunization of recombinantly expressed urocortin fusion proteins.
AB - Urocortin is a recently described 40-meric neuropeptide, which was originally
detected in the rat mid-brain and is believed to play a key role in response to
stress situations. While its function in the central nervous system is rather
well established, the biological role in the periphery is still to be determined.
To investigate its distribution and effect on peripheral cells and tissues, in
the present study, urocortin was recombinantly expressed and specific antibodies
were generated. So far, the immunological detection of urocortin in the rat was
largely dependent on antisera generated in rabbits. However, the polyclonal
nature of the serum and the remote species origin tend to show cross-reactivities
and higher backgrounds. On the other hand, generation of mouse antibodies to rat
urocortin was hampered since mouse and rat urocortin sequences are identical, and
such antibodies would represent auto-reactive antibodies. Despite such
restrictions, the immunization with a combination of various recombinantly
expressed urocortin fusion proteins resulted in the successful generation of
mouse antiurocortin antisera, whose specificities were confirmed by ELISA and
Western blot analysis. To produce the recombinant proteins for immunization, a
cDNA encoding the mature urocortin sequence was cloned and expressed in fusion
either with the glutathione-S-transferase, the maltose-binding protein,
thioredoxin, or a 6X His tag. Depending on the expression system, the solubility
and yield of the recombinant proteins greatly varied. Together with the newly
generated antibodies, these recombinantly expressed urocortin proteins will serve
as valuable tools in further investigations of the biological function of
urocortin.
PMID- 10672925
TI - Inhibition of trifluoperazine-induced DNA fragmentation by cyclic AMP mediated
signaling.
AB - Trifluoperazine (TFP), a phenothiazine antipsychotic agent with calmodulin
antagonist property, induces DNA fragmentation in a dose- and time-dependent
manner in PC12 cells. Various agents affecting calcium mediated intracellular
signal transduction such as calcium chelators, calcium ionopores, inhibitors of
phospholipase C, and activators/inhibitors of protein kinase C did not block TFP
induced DNA fragmentation. Some of these agents themselves induced DNA
fragmentation in the conditions under which they were examined. However, cholera
toxin (selective Gs activator), forskolin (adenylate cyclase activator) or
dibutyryl cyclic AMP (cyclic AMP analogue) inhibited TFP-induced DNA
fragmentation in a dose-dependent manner. These results suggest that it is not
the calcium but the Gs and adenylate cyclase pathways that play an important role
in TFP-induced DNA fragmentation in PC12 cells.
PMID- 10672926
TI - Cymbidium mosaic virus coat protein gene in antisense confers resistance to
transgenic Nicotiana occidentalis.
AB - The nucleotide sequence of the 3'-terminal region of the Korean isolate of
cymbidium mosaic virus (CyMV-Ca) from a naturally infected cattleya was
determined. The sequence contains an open reading frame (ORF) coding for the
viral coat protein (CP) at the 3'-end and three other ORFs (triple gene block or
movement protein) of CyMV. The CP gene encodes a polypeptide chain of 220 amino
acids with a molecular mass of 23,760 Da. The deduced CP sequence showed a strong
homology with those of two CyMVs reported. A construct of the CyMV-Ca CP gene in
the antisense orientation in the plant expression vector pMBP1 was transferred
via Agrobacterium tumefaciens-mediated transformation into Nicotiana occidentalis
which is a propagation host of CyMV. The T1 progeny of the transgenic plants were
inoculated with CyMV and found to be highly resistant to CyMV infection.
PMID- 10672927
TI - Peroral immunization of microencapsulated human VP8 in combination with cholera
toxin induces intestinal antibody responses.
AB - To develop an orally delivered subunit vaccine for rotavirus infection, a trypsin
cleavage product of VP4, recombinant VP8*, was expressed in Escherichia coli. The
recombinant VP8* (rVP8*), purified by affinity chromatography, was reactive
against human rotavirus positive serum in Western-blot analysis. To further
evaluate the immunogenicity of the oral-delivered rVP8*, it was encapsulated with
alginate-microsphere and administered in combination with cholera toxin (CT) as a
mucosal adjuvant perorally into mice. The ELISPOT assay showed that the number of
rVP8*-specific IgG1 antibody secreting cells increased about 3-fold and about 2
fold in spleen and Peyer's patch, respectively as compared to non-immune mice. In
addition, the number of rVP8*-specific IgA antibody secreting cells increased
about 2-fold in Peyer's patch. Finally, rVP8*-specific IgA antibody response was
significantly enhanced in the intestinal fluids from the mice immunized perorally
with encapsulated rVP8* and CT. Taken together, these results indicate that rVP8*
possessed proper immunogenicity and it would be potentially useful as a subunit
vaccine against rotavirus-associated disease through peroral immunization.
PMID- 10672928
TI - TCR internalization induced by peptide/MHC ligands requires the transmembrane
domains of alphabeta chains of TCR, but not the expression of CD8 and Thy-1
molecules.
AB - T-cell receptor (TCR) internalization occurs via TCR recognition of the
peptide/MHC molecule complex on antigen presenting cell (APC). In this study, the
requirements for inducing the internalization of TCR molecules on Ld major
histocompatibility complex (MHC) class I-restricted T-cells were investigated
with 2C cytotoxic T-lymphocyte (CTL) clones with defined peptides as the antigen.
To evaluate the function of the transmembrane region of TCR alphabeta chains in
TCR internalization, we generated T-cell transfectants expressing the wild type
and glycosylphosphatidyl inositol (GPI)-linked form of 2C TCR. Among all peptides
forming proper ligands to 2C TCR, only the Qp2Ca peptide induced TCR
internalization, which was known to have the highest affinity to both Ld MHC
class I molecules and TCR in association with Ld molecules. Such TCR
internalization was not observed in cells expressing the GPI-linked form of 2C
TCR. Furthermore, the expression of CD8 coreceptor and Thy-1 accessory molecules
were both not required for Qp2Ca-induced TCR internalization, and these molecules
did not accompany TCR internalization. Altogether, these results suggest that TCR
internalization on CTL is not a prerequisite for CTL function.
PMID- 10672929
TI - Isolation and characterization of mitochondrial manganese superoxide dismutase
(MnSOD) from Capsicum annuum L.
AB - A cDNA clone for a mitochondrial manganese superoxide dismutase (MnSOD) was
isolated and characterized from red pepper (Capsicum annuum L.). The clone
consisted of 941 bp containing one open reading frame (ORF) of 687 bp, 34 bp/220
bp of 5'/3'-untranslated region. Amino acid sequence of the ORF showed the
highest homology (86%) with that of Nicotiana plumbaginifolia. It encodes for a
polypeptide of 228 amino acids with a molecular mass of 25.5 kDa and a pI value
of 8.39. Genomic Southern hybridization suggested that more than one copy are
present. Northern hybridization showed that the MnSOD transcript was more
abundant in stems than in leaves and roots. When seedlings were treated with
arsenate (0.1-10 mM), the MnSOD transcript level increased slightly at 0.1 mM and
then dropped, while the Cu/ZnSOD transcript level increased at 1 mM, and also
dropped at higher concentrations.
PMID- 10672930
TI - The SH2-SH2-SH3 domain of phospholipase C-gamma1 directly binds to translational
elongation factor-1alpha.
AB - Phospholipase C-gamma1 (PLC-gamma1) is a lipase that hydrolyzes PIP2 to generate
two second messengers, IP3 and DAG. By using the yeast two-hybrid system, we
identified the translational elongation factor-1alpha (EF-1alpha) as a binding
protein of PLC-gamma1 from the human B-lymphocyte library. Direct interaction
between EF-1alpha and PLC-gamma1 was confirmed by the in vitro binding experiment
using purified PLC-gamma1. Furthermore, from the in vitro binding experiment, we
could demonstrate that the carboxyl terminal region of EF-1alpha is involved in
the interaction with PLC-gamma1, and that both SH2 and SH3 domains of PLC-gamma1
are required for the interaction with EF-1alpha. In vivo interaction between EF
1alpha and PLC-gamma1 was confirmed by the immunoprecipitation experiment using
anti-EF-1alpha antibody. The interaction between EF-1alpha and PLC-gamma1 was
enhanced by EGF-treatment. Taken together, we suggest that EF-1alpha might play a
role in PLC-gamma1-mediated signal transduction.
PMID- 10672931
TI - Genomic organization and sequence of the mud loach (Misgurnus mizolepis) growth
hormone gene: a comparative analysis of teleost growth hormone genes.
AB - The mud loach (Misgurnus mizolepis) growth hormone (GH) gene was cloned and a
comparative analysis on its genomic organization was performed. Based on Southern
analysis using various kinds of restriction endonucleases, the GH gene proved to
exist as a single-copy gene in the mud loach. The complete nucleotide sequences
of a 5.1 kb SacI/EcoRI genomic fragment containing the mud loach GH gene and its
5' flanking sequences as well as a mud loach GH cDNA obtained by rapid
amplification of a reverse transcriptase-PCR have been determined. The GH gene
spans 2.0 kb from the start codon to the polyadenylation signal, and contains
five exons and four introns similar to those of carps and mammals. The
evolutionary relation of the mud loach GH gene, inferred by comparative analyses
of gene structures and sequences in each exon and intron of representative
teleost GH genes, reflects the major phylogenetic groupings of teleost.
PMID- 10672932
TI - Effects of dopamine and melatonin on the regulation of the PIT-1 isotype,
placental growth hormone and lactogen gene expressions in the rat placenta.
AB - Rat placenta produces several members of the placental prolactin-growth hormone
(PRL-GH), including placental lactogen (PL) and placental prolactin like protein
(PLP), during pregnancy. It is important to study placental local regulators that
control the expression of PRL-GH genes. We have previously reported that dopamine
(DA) can regulate Pit-1 and PL-II gene expressions. In this study we aimed to
investigate the local expression of melatonin receptor 1a (Mel1a) and the effects
of DA and melatonin on the expressions of PL-Iv, PL-II, PLP-C genes and Pit-1
gene that are involved in the expression of PRL-GH genes in the rat pituitary and
placenta. According to the Northern blot analysis, DA receptor 2 (D2) was
expressed in the rat placenta. We also report on the local expression of Mel1a in
the rat placenta for the first time. Injected DA agonist, bromocriptine (in vivo)
decreased PL-Iv, PLP-C and Pit-1 mRNA levels in the rat placenta. The melatonin
agonist, chloromelatonin in culture media also decreased the levels of PL-Iv, PL
II and PLP-C mRNA. However, melatonin does not affect the Pit-1 mRNA level. These
data suggest that D2 and Mel1a may control the expression of PRL-GH genes in the
rat placenta and its response to the extracellular changes of DA and melatonin
secreted from the maternal organ. However, Pit-1 may not be involved in the Mel1a
induced inhibition of PRL-GH gene expressions in the rat placenta.
PMID- 10672933
TI - Kinase-dependent change in the conformation of the leukocyte NADPH oxidase
subunit p47phox.
AB - The leukocyte NADPH oxidase of neutrophils is a membrane-bound enzyme that
catalyzes the production of O2- from oxygen using NADPH as the electron donor.
Dormant in resting neutrophils, the enzyme acquires catalytic activity when the
cells are exposed to appropriate stimuli. During activation, the cytosolic
oxidase components p47phox and p67phox migrate to the plasma membrane, where they
associate with cytochrome b558, a membrane-integrated flavohemoprotein, to
assemble the active oxidase. In whole cells and under certain circumstances in
the cell-free system, the phosphorylation of p47phox mediates the activation
process. It has been proposed that conformational changes in the protein
structure of cytosolic factor p47phox may be an important part of the activation
mechanism. The total protein steady-state intrinsic fluorescence (an emission
maximum of 338 nm) exhibited by the tryptophan residues of p47phox was
substantially decreased, reflecting on the conformational change that occurs when
p47phox was phosphorylated with protein kinase C. We show here that the
phosphorylation of p47phox by protein kinase A or mitogen-activated protein
kinase, however, had little effect on the intrinsic fluorescence of p47phox. In
addition, the present experiments indicate that in the mutant p47phoxS379A, only
the single S-->A mutation appears to be a major importance for the function of
p47phox, which is able to undergo the change in conformation that takes place
when p47phox is phosphorylated by protein kinase C.
PMID- 10672934
TI - Development of new adherent mutant from human myeloma-derived cell line: in vitro
model of anaplastic transformation of myeloma.
AB - Anaplastic myeloma is a rare but distinct, biologically aggressive variant of
myeloma which usually results from dedifferentiation or anaplastic transformation
of the myeloma cells. The molecular mechanisms that determine the biologic
behavior of anaplastic myeloma and effective treatment modalities have not been
well known due to lack of in vitro models. In the present study, we have
developed an anaplastically transformed mutant from a human myeloma-derived cell
line. In the process of long-term culture of the myeloma-derived IM-9 cell line
in low serum and nutrient conditions, an adherent mutant line was developed and
named IM-9/AD. This mutant cell line displayed several characteristics resembling
anaplastic myeloma such as: 1, large cells with large vesicular nucleus and
prominent nucleolus, multinuclearity and high mitotic figures; 2, loss of
leukocyte-associated antigens; and 3, higher tumorigenecity in scid mice than its
parental cell line. This newly developed mutant cell line may serve as a readily
available in vitro model to investigate the biology of anaplastic myeloma.
PMID- 10672935
TI - LFA-1- and ICAM-1-dependent homotypic aggregation of human thymocytes induced by
JL1 engagement.
AB - Cell-cell adhesion is essential for the appropriate immune response,
differentiation, and migration of lymphocytes. This important physiological event
is reflected in vitro by homotypic cell aggregation. We have previously reported
that a 120 kDa cell surface glycoprotein, JL1, is a unique protein specifically
expressed by immature double positive (DP) human thymocytes which are in the
process of positive and negative selections through the interaction between
thymocyte and antigen-presenting cells (APCs). The function of the JL1 molecule,
however, is yet to be identified. We show here that anti-JL1 monoclonal antibody
(mAb) induced the homotypic aggregation of human thymocytes in a temperature- and
Mg2+-dependent manner. It required an intact cytoskeleton and the interaction
between leucocyte function associated antigen-1 (LFA-1) and intercellular
adhesion molecule-1 (ICAM-1) since it was blocked by cytochalasin B and D, and
mAb against LFA-1 and ICAM-1 which are known to be involved in the aggregation of
thymocytes. Translocation of phosphatidylserine (PtdSer) through the cell
membrane was not detected, implying that the molecular mechanism of JL-1-induced
homotypic aggregation is different from that of CD99-induced homotypic
aggregation. In summary, JL1 is a cell surface molecule that induces homotypic
adhesion mediated by the LFA-1 and ICAM-1 interaction and cytoskeletal
reorganization. These findings suggest that JL1 may be an important regulator of
thymocyte development and thymocyte-APC interaction.
PMID- 10672936
TI - Cloning, nucleotide sequence and expression of thioltransferase (glutaredoxin)
cDNA from Schizosaccharomyces pombe.
AB - Thioltransferase (TTase), also known as glutaredoxin (Grx), is an enzyme that
catalyzes the reduction of a variety of disulfide compounds, including protein
disulfides, in the presence of reduced glutathione. TTase acts as a cofactor for
various enzymes such as ribonucleotide reductase. We previously purified a TTase
from Schizosaccharomyces pombe and its molecular size was determined. In the
present study, a cDNA coding TTase was isolated from a cDNA library of
Schizosaccharomyces pombe by colony hybridization, which was constructed in a
plasmid vector pGAD GH, and its corresponding insert was confirmed by Southern
hybridization. The nucleotide sequence of the 375 bp long cDNA clone reveals an
open reading frame, which encodes a protein of 101 amino acids. The coding region
of the original clone was transferred after the lac promoter of pUC13 vector for
expression in E. coli, and simultaneously, a suitable Shine-Dalgarno (SD)
sequence was added in front of the coding region by PCR. The two primers used for
PCR also separately contained BamHI and HindIII restriction sites. The E. coli
strain (A434) harboring the pUC13 derivative pKU10 showed a 17.3-fold increase in
TTase activity compared to the strain with only the vector plasmid.
PMID- 10672937
TI - An element with palindromic structure is required for the expression of TBP (TATA
box-binding protein) gene in Drosophila melanogaster.
AB - Previously we showed that the 5'-flanking regions between -261 and -207 of the
Drosophila melanogaster TBP (TATA box binding protein) gene is important for its
expression. We further made serial deletion mutants in this region and analyzed
their promoter activities using the transient transfection assay. We found that
the 16 bp deletion from -261 to -245 greatly reduces the promoter activity of the
Drosophila TBP gene. The 16 bp DNA element contains half of a 11 bp long
palindromic sequence, CTTTT-GAAAAG. Disruption of the palindromic sequence by
site-directed mutagenesis severely affected promoter activity. In addition, the
electrophoretic mobility shift assay showed that the oligonucleotide containing
the palindromic sequence can make specific DNA/protein complexes when it was
mixed with the Drosophila nuclear extract, suggesting that it interacts with
nuclear protein(s). Our data suggest that the palindromic sequence has a critical
role in the expression of the Drosophila TBP gene.
PMID- 10672938
TI - Dephasing of spin echoes by multiple heteronuclear dipolar interactions in
rotational echo double resonance NMR experiments.
AB - The application of rotational echo double resonance (REDOR) nuclear magnetic
resonance (NMR) for accurate distance measurements has thus far been largely
restricted to isolated heteronuclear two-spin systems. In the present paper, the
informational content of REDOR curves is explored for systems characterized by
multi-spin interactions. To this end, numerical REDOR simulations are presented
for cases in which single observe spins S are dipolarly coupled to groups of
spins I in distinct geometries. To develop the utility of REDOR for
characterizing dipolar couplings in unknown and/or ill-defined geometries, the
validity ranges and systematic errors of certain analytical approximations are
studied. In the limit of short dipolar evolution times where 0 < deltaS/S0 < or =
0.2 to 0.3, the REDOR difference signal intensity increases approximately
proportional to the square of the dipolar evolution time. Here, the curvature
depends simply on the second moment M2 characterizing the overall strength of the
heterodipolar coupling, irrespective of specific molecular geometries. Fitting
experimental REDOR data in this manner produces slight systematic underestimates
of M2. However, these errors tend to be counterbalanced by additional systematic
errors made by neglecting weak couplings to more remote spins and distribution
effects caused by disorder. Based on these findings, the results suggest a
convenient method of obtaining site-resolved second moment information in
disordered materials.
PMID- 10672939
TI - Solid-state single and triple-quantum 93Nb MAS NMR studies of ferroelectric
Pb(Mg1/3Nb2/3)O3 and a related pyrochlore.
AB - Pb(Mg1/3Nb2/3)O3 (PMN), a well-known relaxor ferroelectric material, and a
related pyrochlore phase have been studied by single- and triple-quantum 93Nb MAS
NMR spectroscopy. The assignment of the NMR resonances has been attempted.
PMID- 10672940
TI - 71Ga NMR of reference GaIV, GaV, and GaVI compounds by MAS and QPASS, extension
of gallium/aluminum NMR parameter correlation.
AB - We report new measurements of NMR parameters for 71Ga in gallium bearing oxide
reference compounds, ranging from perfectly ordered systems to disordered
crystalline structures and their aluminate counterparts. Static, MAS, and QPASS
spectra are obtained at magnetic fields ranging from 7.0 to 18.8 T. With these
results we enhance the previously established correlation between isotropic
chemical shifts of 71Ga and 27Al and propose a correlation between gallium and
aluminum electric field gradients (EFG). This correlation shows that the EFG at
71Ga sites are generally three times greater than those at equivalent 27Al sites.
PMID- 10672941
TI - Strategies for extracting NMR parameters from 23Na MAS, DOR and MQMAS spectra. A
case study for Na4P2O7.
AB - The 23Na magic-angle spinning (MAS), double rotation (DOR) and multiple-quantum
magic-angle spinning (MQMAS) NMR spectra of anhydrous sodium pyrophosphate,
Na4P2O7, measured at five different Larmor frequencies (nuL) ranging from 105.8
MHz (corresponding to 400 MHz 1H frequency) to 211.6 MHz (800 MHz) are analysed
and the complete set of NMR parameters (C(qcc), etaQ and delta(iso)) of the four
crystallographically inequivalent sodium sites were determined with high
accuracy. Different approaches of spectra evaluation are discussed and their
results are compared. The most reliable results are obtained from a combined
evaluation of five DOR and three MQMAS spectra but also from two DOR and one MAS
spectra or even from a single MQMAS spectrum all data can be derived. It is shown
that Na4P2O7 may serve as a useful reference material for experimental set-up and
reliability tests of the various NMR experiments.
PMID- 10672942
TI - Observation of hydroxyl groups by 17O solid-state multiple quantum MAS NMR in sol
gel-produced silica.
AB - 17O NMR parameters (CQ, eta, delta(iso) and T1) are reported for both Si-O-Si and
Si-OH fragments within a silica gel. The Si-OH units have a wide spread of
parameters but are typically characterised by a very short T1 (approximately 0.1
ms) and CQ < 200 kHz. These observations have extremely important implications
for the quantification of such units in these gels and related glassy materials
by 17O NMR. In light of these observations, the 17O NMR experiments have been
optimised and a distinct resonance from the OH group is observed in 1D static and
magic angle spinning (MAS) NMR measurements as well in the multiple quantum (MQ)
experiment.
PMID- 10672943
TI - The influence of a low protein diet in idiopathic hypercalciuria.
AB - A group of 42 hypercalciuric patients (24 males and 18 females) aged 23 to 61
years (mean 45.57+/-12.27) with recurrent stone disease was studied. We applied
for a period of 10 days a normocalcium, moderately low protein diet. We found
statistically significant variations of azotaemia, venous pH, and vitamin D 1-25.
In the 24 h urine collection we found a statistically significant decrease of
nitrogen, uric acid, sodium, chloride, calcium, phosphates, oxalate, and
hydroxyproline. In conclusion, the present study suggests that the restricted
consumption of animal protein can produce a limited effect in urinary
biochemistry. The actual efficiency of this dietary restriction on stone
formation remains to be evaluated by a prospective long-term study of a larger
population. Whether this has an effect on the future incidence of stone formation
has to be further verified.
PMID- 10672945
TI - Pneumatic lithotriptor--a useful tool for challenging renal stone surgery.
AB - Open surgical measures may be undertaken in the treatment of some complex calculi
and manoeuvres such as extended pyelolithotomy or nephrolithotomy may be
necessary. In an attempt to improve surgical results with less morbidity and
maximum ease, we used the Swiss Lithoclast to disintegrate large stones
presenting as hard cases. Five patients with renal pelvic stones associated with
calyceal stones in two and two further cases with staghorn stones were treated
surgically using the pneumatic lithotriptor probe with less dissection and
without nephrotomy. Only one of the patients with staghorn stones had residual
fragments which were then treated with ESWL. We believe that when open surgical
treatment is considered in hard cases, especially in those with small renal
pelvises, the best results may be achieved with minimum surgical intervention if
it is combined with pneumatic lithotripsy.
PMID- 10672944
TI - Mermaid and Potter's syndrome occurring simultaneously.
AB - We herein report a case of a female embryo who died in utero and at autopsy she
was found to have bilateral renal agenesis with the extrarenal manifestations of
Potter's syndrome together with mermaid syndrome which is a rare combination.
From all the anomalies of the upper urinary tract bilateral renal agenesis seems
to have a cardinal role in the survival of the embryo afflicted with the spectrum
of associated anomalies.
PMID- 10672946
TI - Arteriovenous shunting in a giant renal angiomyolipoma. A rare condition.
AB - We report a case of a 33-year-old woman with tuberous sclerosis and bilateral
angiomyolipomas. She suffered from acute left flank pain due to retroperitoneal
haemorrhage. During renal arteriography an arteriovenous shunting was found in
the left tumour. Angiomyolipoma is a rare cause of angiographically demonstrable
arteriovenous shunting.
PMID- 10672947
TI - Multicentricity in renal cell carcinoma.
AB - OBJECTIVE: To find the incidence of multicentric renal cell carcinoma and its
possible relationship to the other clinical and pathologic findings. METHODS: A
total of 40 patients with renal cell carcinoma underwent radical nephrectomy
between March 1994 and January 1996 at Hacettepe University, School of Medicine,
Department of Urology. All of the materials were examined grossly and
histologically by the same pathologist. RESULTS: Among 40 kidneys 4 had satellite
carcinoma (10%), 3 of them had been shown by preoperative imaging techniques, 1
was found histopathologically. CONCLUSION: If preoperative imaging techniques do
not show additional lesion in the kidney besides the small early stage primary in
incidentally discovered patients, the incidence of satellite renal cell carcinoma
is low enough to justify nephron sparing surgery.
PMID- 10672948
TI - Ureteric stone extraction with retrograde irrigational balloon catheter.
PMID- 10672949
TI - Retroperitoneal malignant fibrous histiocytoma.
AB - Authors review the case history and follow-up of a rare malignant fibrous
histiocytoma patient, based on the relevant literary data. The tumour filled the
retroperitoneum on the right side, in front of the right kidney. Intravenous
urography and computer tomography revealed a 10 x 15 cm sized mass, suspect of
being a kidney tumour. Upon surgery, the tumour was found to be a retroperitoneal
malignant fibrous histiocytoma. In connection with the case, a brief review is
given of the storiform type of malignant fibrous histiocytoma, regarding its
aetiological, clinical and pathological aspects, the difficulties in diagnosis,
as well as the therapeutic possibilities. Authors regard their case worthy of
publication because of the retroperitoneal location and significant size of the
tumour, and because of the unproven diagnosis prior to surgery. Even after 4
years the patient is symptom- and complaint-free, and CT has revealed no
metastases.
PMID- 10672950
TI - The use of polytetrafluoroethylene (Gore-Tex) grafts in reconstruction of the
urinary bladder.
AB - The safety and histopathologic effects of polytetrafluoroethylene (Gore-Tex)
grafts in reconstruction of the urinary bladder were examined. Following partial
excision of the bladder Gore-Tex was placed, and the rats were sacrificed at days
7, 14 and 30. Gore-Tex did not cause urine infection, and there was no
peritonitis or sepsis in any of the rats. Inflammation around the Gore-Tex
diminished after four weeks. Some mononuclear cells and exudate were observed on
the inner surface of the Gore-Tex. There was no inflammation or fibrosis in the
mucosa and muscular layers of the remaining bladder. In this study the Gore-Tex
graft was found to be an infection resistant, urine impermeable material, with no
adverse effects on the urinary bladder. Gore-Tex is suggested as a safe material
for the reconstruction of the urinary bladder.
PMID- 10672951
TI - Vesicovaginal and ureterovaginal fistulas: a review of 39 cases.
AB - The aim of this retrospective study was to present our experience in the
treatment modalities of patients with vesicovaginal and ureterovaginal fistula.
Between 1987 and 1997, 39 patients were diagnosed and operated on for
vesicovaginal and ureterovaginal fistula. Of these patients, 31 had
vesicovaginal, 7 had ureterovaginal and 1 had both vesicovaginal and
ureterovaginal fistula. The ureterovaginal fistulas were repaired by simple
ureteroneocystostomy with 100% success. Vesicovaginal and urethrovaginal fistulas
were repaired transvaginally in 7 cases, transabdominally in 23 cases and
endoscopically in two cases with 77% success at first attempt and 92% success
with several attempts. The successful repair of urinary tract fistulas can be
achieved in the majority of cases by adhering to the basic surgical principles.
The optimum approach is that which works best in the surgeon's hands.
PMID- 10672952
TI - Clinical significance of nuclear p53 protein accumulation in bladder cancer.
AB - OBJECTIVES: To investigate the correlation of nuclear p53 accumulation with
disease outcome in a cohort of patients with transitional cell carcinoma of the
bladder. METHODS: A total of 90 patients (11 female, 79 male) with transitional
cell carcinoma of the bladder were included in this study. Tumour samples from
the primary tumour were analysed by immunohistochemistry for nuclear accumulation
of p53 protein. Outcome of each patient was recorded and investigated for a
possible relation with p53 status. RESULTS: Nuclear p53 deposition was determined
in 22 specimens. The nuclear p53 deposition was seen in less than 20% of the
nuclei examined in 13 and more than 20% in 9 cases. No stromal staining was
observed. Nuclear p53 deposition was present in 15.2% (7/46) of grade 2 tumours,
and 34% (15/44) of grade 3 tumours (p=0.037). Stage distribution revealed 15.5%
(5/33) positivity in stage pTa, 25.8% (8/31) in pT1 and 34% (9/26) in stage pT2-3
tumours. Tumours with p53 nuclear accumulation had a higher rate of recurrence
and progression and shorter survival. CONCLUSION: Results of the current study
indicate p53 as an important factor in determination of biological behaviour of
bladder cancer.
PMID- 10672953
TI - Nitric oxide based influence of nitrates on micturition in patients with benign
prostatic hyperplasia.
AB - BACKGROUND: Nitric oxide (NO) is involved in the physiologic regulation of smooth
muscle relaxation in the prostate. Organic nitrates act as NO donors. In this
prospective open study we prove the influence of orally given nitrates on
micturition. METHODS: Thirty-two patients underwent a urological medical check-up
prior to starting nitrate medication for cardiovascular disease. We examined peak
flow rates, residual urine, IPS-score, PSA level and prostate volume. Exact
inclusion and exclusion criteria were defined. Fifteen patients suffered from
obstructive symptoms, 17 patients reported no subjective micturition problems.
Urological re-evaluation was performed two weeks and three months after nitrate
medication. RESULTS: A significant improvement of peak urinary flow rates (+3.1
ml/s; p<0.05), IPS score and significant decrease of residual urine volume (-22
ml; p<0.05) were found in the symptomatic patients. No significant changes of
micturition parameters were found in asymptomatic patients. PSA levels and
prostate volumes did not change in either groups. CONCLUSIONS: Organic nitrates
influence micturition parameters in patients with obstructive benign prostatic
hyperplasia. This might be explained by the known mechanism of NO donation
(smooth muscle relaxation) of nitrates. More functional controlled studies are
necessary to describe the grade of influence of nitrates on the prostate.
Concomitant oral medication with nitrates must be considered as a relevant bias
factor on BPH in future clinical studies.
PMID- 10672954
TI - Relationship between HLA-DR antigen and HLA-DRB1 alleles and prostate cancer in
Japanese men.
AB - PURPOSE: Human leukocyte antigens (HLA) are cell surface glycoproteins playing a
key role in the immune system. In some cancers, changes in major
histocompatibility complex (MHC) class I and II expression, usually a reduction
or loss of these molecules, appear to provide a mechanism whereby tumour cells
may escape host immunity. We investigated the relationship between HLA,
especially class II, molecules and prostate cancer in Japanese men using
molecular techniques. MATERIALS AND METHODS: HLA class II typing was performed by
the polymerase chain reaction-sequence specific primer (PCR-SSP) method of
analysis and/or a commercial rapid assay based on the PCR followed by reverse dot
blot hybridization of the PCR products (Inno-LiPA assay). Allele frequencies were
calculated. HLA allele frequencies reported in 1216 healthy Japanese individuals
were used as the control data. Differences in allele frequency between subjects
and the control group were analyzed by the chi-square test. The relationship
between HLA antigens/alleles and prostate cancer is expressed in terms of
relative risk (RR). RESULTS: The frequencies of HLA-DR4 were significantly higher
in Japanese men with prostate cancer than in the healthy control group (gene
frequency 36.2% vs. 26.3% in control, p<0.05), although the relative risk of
prostate cancer was less than 2. Furthermore, the frequencies of HLA-DRB1-0406,
0410 and 1405 allele were significantly higher in the prostate cancer group than
in the control group (allele frequency was 7.3%, 4.5% and 5.4% vs. 3.03%, 1.79%
and 2.22%, p<0.05, respectively). RR of those HLA-DRB1 allele for prostate cancer
was 2.6 in each allele. CONCLUSIONS: HLA molecules may be useful for the early
detection of prostate cancer as a risk factor, and also for recognizing cancer
activity by using them as a marker helpful in the choice of appropriate treatment
by predicting prognosis.
PMID- 10672955
TI - Improved discrimination of prostate cancer and benign prostatic hyperplasia by
means of the quotient of free and total PSA.
AB - The value of t-PSA (total prostate specific antigen) and of the quotient of free
and t-PSA (% f-PSA) for the discrimination of BPH (benign prostatic hyperplasia)
and PC (prostate cancer) as well as possible influencing factors were subject to
examination under study conditions. The sera of 210 patients (131 BPH, 79 PC
patients) were examined by means of the Immulite test; thereof 76 male patients
(47 BPH, 29 PC patients) were found to have a t-PSA-value between 4 and 10 ng/ml
(grey area). Apart from the age and the findings of rectal digital examination,
we recorded the prostate volume, indications of non-specific increases in PSA and
for PC patients also the TNM-G stage. For patients with prostate cancer the
quotient of f- and t-PSA was significantly lower (median: 0.08) than compared to
patients with BPH (median: 0.22) (p<0.001). Also in the grey area the quotient
was significantly lower in patients with malignant diagnosis (median: 0.12) than
for patients with a non-malignant diagnosis (median: 0.21) (p<0.001). ROC curves
were prepared in order to compare the capability of discrimination of the two
parameters. At this point, the better discrimination potential of the quotient in
the grey area became evident. Due to the fact that priority was given to the
detection of carcinoma, the threshold value was defined at a level at which high
sensitivity (90%) is existent in combination with an acceptable specificity
(approx. 50%). The resultant values are for the total PSA area 0.21, for the grey
area 0.19 as a cut-off. Neither the age, nor the prostate volume, nor urinary
tract infections had any influence upon the quotient. There was also no
correlation between the stage or the grading of the tumour and the percentage of
the f-PSA. The quotient alleviates the discrimination between BPH and PC, in
particular in the diagnostically problematic grey area. Thus, it can serve as an
aid for the decision "biopsy or re-biopsy". As there is currently no standardized
method for the application of % f-PSA, there is a requirement for further
examination under homogeneous criteria.
PMID- 10672956
TI - Demonstration of testicular apoptosis in human male infertility states using a
DNA laddering technique.
AB - DNA laddering, morphometric analysis, and in-situ end labelling of testis biopsy
tissue obtained from azoospermic or severely oligozoospermic men revealed
increased apoptosis frequency, implicating a possible role of apoptosis in the
pathogenesis of human male infertility.
PMID- 10672957
TI - Echo-colour doppler ultrasonography in the diagnosis of varicocele.
AB - The relationship between varicocele and infertility has long been defined. About
a third of the male patients undergoing evaluation for infertility present with a
varicocele. Sixty male patients between 17 and 35 years of age (mean 25.6) were
examined with a colour-doppler flow imaging system. The diameters of the veins in
the pampiniform plexus were measured by gray-scale sonography. Our findings were
classified with regard to venous diameter, the existence or non-existence of
reflux, the circumstances under which these findings were recorded (e.g. during
normal respiration and standing position or during Valsalva manoeuvre and supine
position). Finally our results suggest that: (a) the clinical significance of the
presence of dilated veins or reflux during increased intraabdominal pressure and
under similar circumstances should be regarded with caution; (b) positive
findings during normal inspirium are highly significant (grades III and IV).
PMID- 10672958
TI - Factors involved in diagnostic delay of testicular cancer.
AB - In testicular cancer, which is one of the highly curable cancers, the beneficial
effect of early diagnosis on survival has been well accepted for years. This
study was planned to determine the probable factors involved in diagnostic delay
of testicular cancer. A total of 140 patients with testicular cancer were
included in this study. We attempted to find a relationship between the mode of
presentation, stage of the tumour, patients' socioeconomic status and the delay
in diagnosis. Majority of patients presented with scrotal pain (49.3%). No
significant correlation was found between the mode of presentation and stage of
the disease (p>0.05). The median time of delay in diagnosis was 5.4 months. The
stage at presentation was not influenced by the delay in diagnosis. Similarly the
annual income and the educational level of the patients had no significant impact
on the delay in diagnosis. No effect of delay in diagnosis on the stage at
presentation could be demonstrated in our study. Our results indicate that in
this country people are not thoroughly educated about the importance of routine
self-examination of the testes. It must also be emphasized that painful
testicular masses need to be evaluated carefully to rule out malignancy.
PMID- 10672959
TI - Immature germ cells in semen and their correlations with other semen parameters.
AB - PURPOSE: The significance of the presence of leukocytes and immature germ cells
in semen and other parameters of semen is currently a subject of controversy.
MATERIALS AND METHODS: Semen from 572 subfertile patients was analyzed according
to WHO criteria and leukocytes as well as immature germ cells were assessed by
identifying the round cells in semen by peroxidase staining. Microbiological
investigation was carried out in cases with leukocyte counts of >1,000,000/ml.
RESULTS: It was found that as the concentration of spermatozoa decreased the rate
of immature germ cells increased and this increase was accompanied by a decrease
in motility and in the number of spermatozoa with normal morphology. As the sperm
count increased, motility, number of spermatozoa with normal morphology and of
immature germ cells also increased whereas an increase in sperm motility was
accompanied by an increase in the percentage of spermatozoa with normal
morphology. Microbiological investigations were negative in patients with semen
leukocyte counts of >l,000,000/ml. CONCLUSIONS: Although it is possible to
establish that the leukocyte and immature germ cell counts correlate with other
parameters of semen, these correlations are not statistically significant. The
most significant finding is that as the number of sperms decreases, the ratio of
immature germ cells to total germ cells increases. While assessing immature germ
cells instead of giving special attention to the number of immature germ cells in
semen, the ratio of immature germ cells to total germ cells should be considered.
The increase of leukocyte count in the semen of oligospermic patients may not
always mean leukospermia.
PMID- 10672960
TI - The significance of testicular reactive oxygen species on testicular histology in
infertile patients.
AB - This study was designed to investigate the relationship between the effects of
testicular reactive oxygen species (ROS) levels and testicular histology on
infertile patients with the aid of xanthine oxidase system and testicular tissue
malondialdehyde levels. Forty patients with idiopathic infertility constituted
our study group. Bilateral testicular biopsies were performed and spermatogenesis
was assessed histopathologically. Patients were divided into 4 groups according
to spermatogenic pattern (normal spermatogenesis; hypospermatogenesis; maturation
arrest; Sertoli cell only syndrome). Testicular tissue xanthine oxidase and
malondialdehyde (MDA) concentrations were analyzed in each sample by
spectrophotometric assay and thiobarbituric acid reaction assay, respectively.
Testicular tissue MDA and xanthine oxidase concentrations were not statistically
different in patients having normal spermatogenesis, with respect to Sertoli cell
only syndrome, maturation arrest and hypospermatogenesis, respectively. As a
result of our study we think that there are still some factors other than ROS
which may be important contributors to spermatogenetic injury that need to be
examined.
PMID- 10672961
TI - Relationship between zinc concentrations in seminal plasma and various sperm
parameters.
AB - The zinc concentration in seminal plasma from 98 infertile male patients and 8
fertile males was measured. The zinc concentration of the seminal plasma in
azoospermic and oligoasthenozoospermic patients was significantly lower than that
in the other groups (each, p<0.05 ). The seminal plasma zinc concentration in
asthenozoospermic males was significantly higher than that in any other group
(p<0.05). There was a positive correlation of zinc concentration with sperm
concentration (r=0.33, p<0.05) and with sperm motility (r=0.22, p<0.05), while
there was no correlation with sperm morphology. A correlation between zinc
concentration and plasma testosterone concentration was observed (r=0.24,
p<0.05). It is concluded that excessively high zinc concentration is apparently
related to defective motility in asthenozoospermic patients, even though adequate
seminal plasma content of the element is required for normal sperm function.
PMID- 10672962
TI - Diagnostic application of AAP isoenzyme separation.
AB - We describe the separation of alanylaminopeptidase (AAP) from urine into two
isoenzymes: a particulate and a soluble form. The separation was accomplished
using ion-exchange column chromatography on DEAE-52 cellulose. The purity of the
isolated forms was confirmed electrophoretically. We attempted to create a method
allowing the quantitative assessment of AAP isoenzymes in urine based on
electrophoretic separation in 7.5% polyacrylamide gel with subsequent
densitometric analysis. The content of AAP isoenzymes in examined urine was
estimated using ultracentrifugation. The differences in the content of cytosolic
and microsomal forms were observed suggesting the possibilities of using AAP
isoenzymes in diagnostics. Furthermore, the effect of temperature on the activity
of AAP separated on DEAE-52 cellulose was studied.
PMID- 10672963
TI - The effects of dexamethasone on the response of bronchus-associated lymphoid
tissue to intranasal administration of formalin-killed Pasteurella haemolytica A2
in goats.
AB - A trial was conducted to observe the immediate and chronic effects in goats of
dexamethasone administration on the bronchus-associated lymphoid tissue (BALT)
response to intranasal administration of formalin-killed Pasteurella haemolytica
A2. Twenty-four goats were divided into four groups. Those in group 1 were
injected intramuscularly with 1 mg/kg dexamethasone on three consecutive days,
followed by intranasal exposure to formalin-killed P. haemolytica A2 one day
after the last dexamethasone treatment. The goats in group 2 were similarly
injected with dexamethasone followed by intranasal exposure to formalin-killed P.
haemolytica A2 21 days after the last dexamethasone treatment. The animals in
group 3 were exposed intranasally to formalin-killed P. haemolytica A2 without
prior dexamethasone treatment. The animals in group 4 were untreated controls.
The intranasal exposures to formalin-killed P. haemolytica A2 were repeated 2
weeks later. Intranasal exposure to formalin-killed P. haemolytica 1 day after
dexamethasone treatment further reduced the number and size of BALT compared to
the untreated control. Significantly (p < 0.01) more reduction of BALT occurred
in goats exposed to formalin-killed P. haemolytica A2 21 days after dexamethasone
treatment. On the other hand, intranasal exposure of goats without prior
dexamethasone treatment stimulated the BALT compared to the untreated controls.
PMID- 10672964
TI - Preliminary studies on hepatic carnitine palmitoyltransferase in dairy cattle
with or without fatty liver.
AB - The hepatic mitochondrial carnitine palmitoyltransferase (CPT) activity was
measured by fluorimetric assay in dairy cows with or without fatty liver. CPT
activities in 13 lactating cattle and in 6 non-lactating cows were 304.4+/-86.6
micromol CoA/min per g protein and 169.3+/-84.8 micromol CoA/min per g protein,
respectively. This difference was significant (p < 0.05). CPT activities in early
lactation (0-110 days after calving), mid-lactation (111-220 days after calving)
and late lactation (over 220 days after calving) were 278.9+/-68.0, 312.4+/-124.1
and 320+/-59.3 micromol CoA/min per g protein, respectively. There was no
significant difference between the values at different stages of lactation. The
CPT activity in 10 lactating cows with fatty liver unrelated to calving was
201.3+/-80.0 micromol CoA/min per g protein. CPT activity in 10 cattle with fatty
liver was significantly lower than that in normal lactating cattle. Based on
these findings, clinical fatty liver unrelated to calving appears to be
associated with a decrease in hepatic CPT activity.
PMID- 10672965
TI - The influences of dietary selenium and vitamin E intakes on milk somatic cell
counts and mastitis in cows.
AB - Dietary supplements of selenium and vitamin E in greater amounts than are
required for nutritional adequacy can have complementary functions in reducing
somatic cell counts and both the severity and duration of clinical mastitis.
Selenium inadequacy is geographically widespread and can frequently be a year
round problem. In contrast, an adequate intake of fresh grass and quality grass
silage or other green, leafy material should provide adequate vitamin E. Many
observations indicate that in farm situations where there is good udder hygiene
and where long-acting antibiotic treatment is given at drying off, significant
correlations are found between the mean bulk milk somatic cell counts and the
blood selenium concentration or glutathione peroxidase activity in the blood,
even where plasma vitamin E concentration is fully adequate. The accompanying
reduced incidence of clinically affected quarters diminishes the need for
corrective antibiotic treatment during lactation. Presentation of selenium and
vitamin E within a sustained-release rumen bolus system during the dry period and
into the succeeding lactation is a convenient means of supplementation to avoid
over- or under-consumption by individual cows within a group. Adequate hygiene of
the environment, the milking equipment and the udder are essential.
PMID- 10672966
TI - Pharmacokinetics and dosage regimen of enrofloxacin in buffalo bulls after
intramuscular administration.
AB - The disposition kinetics and dosage regimen of enrofloxacin were investigated in
breeding buffalo bulls following a single intramuscular administration of 5
mg/kg. The absorption half-life, half-life of the terminal phase, apparent volume
of distribution and total body clearance were 0.262+0.099 h, 1.97+/-0.23 h,
0.61+/-0.13 L/kg and 210.2+/-18.6 ml/(kg.h), respectively. Therapeutic plasma
levels (> or = 1 microg/ml) were maintained for up to 6 h. A satisfactory
intramuscular dosage regimen for enrofloxacin in buffalo bulls would be 8.5 mg/kg
followed by 8.0 mg/kg at 8 h intervals.
PMID- 10672967
TI - Pharmacokinetics of amoxicillin trihydrate in Desert sheep and Nubian goats.
AB - The pharmacokinetics of amoxicillin were studied in five Desert sheep and five
Nubian goats after intravenous (i.v.) or intramuscular (i.m.) administration of a
single dose of 10 mg/kg body weight. Following i.v. injection, the plasma
concentration-versus-time data were best described by a two-compartment open
model. The kinetic variables were similar in both species except for the volume
of the central compartment (Vc), which was larger in sheep (p<0.05). Following
i.m. injection, except for the longer half-life time of absorption in goats
(p<0.05), there were no significant differences in other pharmacokinetic
parameters between sheep and goats. The route of amoxicillin administration had
no significant effect on the terminal elimination half-life in either species.
The bioavailability of the drug (F) after i.m. administration was high (> 0.90)
in both species. These results indicate that the pharmacokinetics of amoxicillin
did not differ between sheep and goats; furthermore, because of the high
availability and short half-life of absorption, the i.m. route gives similar
results to the i.v. route. Therefore, identical intramuscular and intravenous
dose regimens should be applicable to both species.
PMID- 10672968
TI - A labelled avidin-biotin ELISA to detect antibodies to caprine arthritis
encephalitis virus in goats' sera.
AB - A labelled avidin-biotin ELISA (lab-ELISA) was developed and compared with
indirect ELISA (i-ELISA) and agar-gel immunodiffusion assay (AGID) for its
efficacy in detecting antibodies against caprine arthritis-encephalitis virus
(CAEV) in goat sera. The enzyme immunoassays were standardized using 113 sera
from CAEV-negative goat flocks. The tests were compared using the results from
339 serum samples. The lab-ELISA showed the greatest number of positive results
(94/339) as compared with AGID (51) and i-ELISA (64). The comparison of the other
two tests with the lab-ELISA showed an agreement of 87.3% with AGID and 90.6%
with i-ELISA. The lab-ELISA may be useful for screening large populations for
CAEV antibodies, in epidemiological surveys and in the control of caprine
arthritis-encephalitis.
PMID- 10672969
TI - Anxiolytic-like effects of 7-nitroindazole in the rat plus-maze test.
AB - It is considered that nitric oxide (NO) is one of the most interesting research
subjects. Because the actual role of NO in the mechanism of anxiety is still
unclear, in this study, the involvement of NO in the mechanism of anxiety was
investigated, using the plus-maze test. 7-Nitroindazole (7-NI) (15, 30, 60, 90,
and 120 mg/kg), a new nitric oxide synthase (NOS) inhibitor was studied. The time
spent on open arms and open-arm visits was evaluated. 7-NI, at 15-120 mg/kg doses
potently increased the time spent on open arms and open-arm visits. However, at
120 mg/kg it attenuated the time spent on the open arms, compared to at 90 mg/kg.
This effect was attributed to decreased locomotor activity in the higher dose
group. Neither L-arginine, nor D-arginine (100 mg/kg) significantly affected any
of the behavioral parameters measured in the rat elevated plus-maze test. Neither
drugs revealed any effect on locomotion. L-Arginine but not D-arginine given 10
min before 7-NI, reversed the 7-NI induced anxiolytic-like effects. These data
support an involvement of NO in the process of anxiety, and further suggest that
the anxiolytic-like effect of 7-NI may be attributable to the inhibition of NO
synthesis.
PMID- 10672970
TI - Turning in rats following intraaccumbens shell injections of amphetamine or
eticlopride.
AB - In recent years there has been interest in possible differential behavioral
functions of the core and shell subregions of the nucleus accumbens. The present
study compared the effects of accumbens core and shell injections of (+)
amphetamine on turning behavior in rats; the turning effects of the selective D2
antagonist (-)-eticlopride injected into the shell were also tested. Rats (n =
28) were implanted unilaterally with guide cannulae and subsequently tested for
turning in seven 20-min sessions. Amphetamine (10.0 and 20.0 microg but not 5.0
microg/ 0.5 microl) elicited contralateral turning following injection into the
shell, while the same doses into the core had no effect. In animals given
systemic amphetamine (2.0 mg/kg), eticlopride (10.0 but not 1.0 or 0.1 microg/0.5
microl) injected into the shell region of the accumbens produced ipsilateral
turning. These results suggest that the accumbens shell, but not the core, is a
critical site for turning behavior.
PMID- 10672971
TI - Acute and chronic effects of gepirone and fluoxetine in rats tested in the
elevated plus-maze: an ethological analysis.
AB - The potential role of 5-hydroxytryptamine (5-HT) in anxiety has been the subject
of much research, most of it addressed to the hypothesis that 5-HT promotes
anxiety and, therefore, that drugs that reduce 5-HT functions will be effective
anxiolytic agents in human anxiety disorders. However, the effects of
serotoninergic drugs in different behavioral paradigms have been inconsistent.
These inconsistencies have been particularly well illustrated in the elevated
plus-maze. In the present study we provided an ethopharmacological analysis (in
addition to conventional measures) of the behavior of rats in the elevated plus
maze with transparent walls after acute and chronic treatments with gepirone, an
agonist of 5-HT1A receptors, and fluoxetine, a selective inhibitor of serotonin
reuptake. Although gepirone has been used to treat anxiety, fluoxetine is a
mainstay in the treatment of depression. Acute treatment with gepirone (1, 3,
5.6, and 10 mg/kg, IP) produced an anxiogenic profile with increased risk
assessment behaviors (e.g., flat-back approach) and decreased behavioral measures
that are inversely related to "anxiety" (e.g., head dipping and end-arm
activity). In contrast, chronic gepirone (10 mg/kg day, PO) produced an opposite
effect showing an anxiolytic profile that is consistent with the clinical use of
this drug, which shows efficacy after 2-4 weeks of treatment. Acute fluoxetine
(5.6 and 10 mg/kg, IP) also produced an anxiogenic profile with reduced head
dipping and end-arm activity. On the other hand, chronic fluoxetine (10 mg/kg
day, PO) had no effect on any of the behavioral measures. These data demonstrate:
(a) the anxiogenic and anxiolytic effects of acute and chronic gepirone,
respectively, corroborate with the observed effects of these treatments in the
clinic; (b) similarly, the anxiogenic effects of acute fluoxetine observed here
have also been reported in clinical studies with 5-HT reuptake blockers. This
class of compounds has not been systematically used as anxiolytic; (c) the
elevated plus-maze with transparent walls shows good sensitivity for evaluating
serotonergic drugs with anxiogenic and anxiolytic profile.
PMID- 10672972
TI - Role of brain dynorphin in nitrous oxide antinociception in mice.
AB - Earlier studies indicate that nitrous oxide antinociception is mediated by opioid
receptors, and we have hypothesized that nitrous oxide stimulates a neuronal
release of an endogenous opioid peptide (EOP) that stimulates opioid receptors.
To further test this hypothesis, male NIH Swiss mice were pretreated
intracerebroventricularly with rabbit antisera to opioid peptides or with various
inhibitors of peptidases involved in the degradation of EOPs. Mice were
subsequently exposed to three different concentrations of nitrous oxide in
oxygen, and their antinociceptive responsiveness was measured using the acetic
acid abdominal constriction test. Nitrous oxide antinociception was significantly
attenuated by 24-h pretreatment with antisera to various fragments of dynorphin
(DYN) but not by antisera against methionine-enkephalin (ME) or beta-endorphin
(beta-EP). In other experiments, nitrous oxide antinociception was significantly
enhanced by 30-min pretreatment with phosphoramidon, an inhibitor of
endopeptidase 24.11, which has been implicated in DYN degradation, but not
bestatin or captopril, which inhibit aminopeptidase and angiotensin-converting
enzyme, respectively. The latter enzymes have been implicated in degradation of
certain EOPs albeit not DYN. These findings support the hypothesis that nitrous
oxide antinociception in the mouse abdominal constriction test is mediated by
endogenous DYN acting in the central nervous system.
PMID- 10672973
TI - The role of the benzodiazepine-GABA system in the memory processes of the day-old
chick.
AB - This series of experiments investigated the effect of the benzodiazepine diazepam
on memory formation in day-old chicks trained on a single-trial, passive
avoidance task. The findings indicate that diazepam has a dose-specific and time
dependent effect on memory processes. A 0.125-mg/kg dose of diazepam administered
immediately after training led to amnesia in these subjects only after 30 min
following learning. Pretreatment with bicuculline and flumazenil were effective
in ameliorating the memory deficits caused by diazepam, and consolidated memory
function in saline-treated controls following strong and weak aversant training.
These findings suggest that benzodiazepine effects on memory are mediated by
their effects on arousal, possibly by the release of noradrenaline, which is
critical to the establishment of long-term memory.
PMID- 10672974
TI - Serotonergic deficits and impaired passive-avoidance learning in rats by MDEA: a
comparison with MDMA.
AB - The serotonergic deficits induced by 3,4-methylenedioxyethamphetamine (MDEA,
"eve"), were examined and compared with 3,4 methylenedioxymethamphetamine (MDMA,
"ecstasy"). A single dose of MDEA (10, 20, or 40 mg/kg IP) induced a dose-related
hyperthermia, but only the highest dose significantly reduced 5-HT content and 5
HT transporter density in the frontal cortex and in the hippocampus 7 days later.
Long-term serotonergic deficits were much more marked when MDEA was given
repeatedly (40 mg/kg IP., b.i.d., for 4 consecutive days). Single or repeated
administration of MDEA induced no change on 5-HT1A receptor density in the
frontal cortex, brain stem, or hippocampus, although 3 h after both treatments
plasma corticosterone levels were significantly increased. MDEA (5-20 mg/kg, IP)
produced significant retention deficits in a passive-avoidance learning task.
Conversely, 7 days after the repeated administration of MDEA (40 mg/kg b.i.d.,
for 4 consecutive days) no effect on passive-avoidance performance was observed
unless rats were treated again with another dose of MDEA (20 mg/kg IP) 30 min
before the training trial. The 5-HT1A receptor antagonist, WAY 100635, prevented
the impairment in retention performance induced by 8-hydroxy-2-(di-n
propylamino)tetralin (8-OH-DPAT), but not by MDEA or MDMA, indicating that the
effect of these amphetamine derivates was not mediated by 5-HT1A receptor
activation. The results suggest the risk of serotonergic dysfunction associated
with MDEA abuse in humans.
PMID- 10672975
TI - Repeated treatments with 7-OH-DPAT: context-independent behavioral sensitization
and conditioned hyperactivity.
AB - The primary objective of this study was to determine whether the expression of
behavioral sensitization to the putative dopamine D3 receptor agonist 7-OH-DPAT
is context dependent. Three groups (n = 8 each) of male Wistar rats (250-350 g)
were given nine injections (at 48-h intervals) of 7-OH-DPAT (1.0 mg/kg, SC) or
vehicle 15 min before and after activity testing. The paired group received 7-OH
DPAT before activity testing and vehicle after testing. The unpaired group
received vehicle before and 7-OH-DPAT after testing, and the vehicle control
group received two vehicle injections. Locomotor activity was measured in
photocell arenas for 2 h. After the first seven sessions, all rats were tested
for activity following a vehicle injection to test for possible conditioning
effects. Prior to the 11th session, all rats were given a challenge injection of
7-OH-DPAT (1.0 mg/kg, SC) to test for sensitization. Major findings were as
follows: (a) the 7-OH-DPAT/paired group displayed a progressively greater
increase in locomotor activity with repeated treatments; (b) the 7-OH-DPAT/paired
group was significantly more active than either the vehicle control group or the
7-OH-DPAT/unpaired group during the vehicle test session; and (c) after the 7-OH
DPAT challenge injection, the paired and unpaired 7-OH-DPAT groups were
significantly, and equally, more active than the vehicle control group. In
contrast to previous findings with the D2-type dopamine agonists bromocriptine
and quinpirole, these results suggest that the expression of behavioral
sensitization to 7-OH-DPAT is not context dependent. Moreover, these results
suggest that the apparent conditioned hyperactivity and context dependency often
observed after repeated dopamine agonist treatments may not be related to the
same associative and/or nonassociative mechanisms.
PMID- 10672976
TI - Effects of acute nicotine on several operant behaviors in rats.
AB - The present experiment assessed nicotine's effects on complex cognitive processes
using a variety of operant tasks in rats, including incremental repeated
acquisition (IRA) to assess learning; conditioned position responding (CPR) to
assess auditory, visual, and position discrimination; progressive ratio (PR) to
assess motivation; temporal response differentiation (TRD) to assess timing; and
differential reinforcement of low response rates (DRL) to assess timing and
response inhibition. Acute nicotine administration (0.0, 0.3, 0.42, 0.56, 0.75,
and 1.0 mg/kg, IP) increased IRA and CPR response rate without significantly
altering accuracy. Nicotine had similar effects on response rate for PR. For TRD,
nicotine had a U-shaped dose effect on accuracy, but failed to shift the mode of
the TRD response distribution. For DRL, nicotine reduced accuracy and also
shifted the mode of the DRL response initiation time distribution to the left.
Nicotine produced an inverted U-shaped dose-effect curve for the overall number
of "bursting" responses under both of these schedules. The results of this
experiment suggest that nicotine can impair performance on some aspects of
cognitive-behavioral performance, while simultaneously improving performance on
others.
PMID- 10672977
TI - Effects of labetalol treatment on the physiological and subjective response to
smoked cocaine.
AB - Adrenergic receptors mediate some of the physiological and possibly behavioral
effects of cocaine. The purpose of this study was to investigate the effect of
treatment with a peripherally acting adrenergic blocking drug labetalol on the
cardiovascular and subjective response to repeated deliveries of smoked cocaine.
In this double-blind, placebo-controlled, crossover study, 12 cocaine users were
treated with a single 100 or 200 mg dose of labetalol, or placebo in each of
three experimental sessions. Starting 2 h after the medication treatment,
subjects received three doses of 0.4 mg/kg smoked cocaine, 30 min apart.
Labetalol treatment significantly attenuated the cocaine-induced increases in
heart rate and systolic blood pressure. This effect of labetalol on the
cardiovascular response did not decrease with repeated cocaine deliveries. The
subjective response to smoked cocaine deliveries was not affected by labetalol
treatment. These results suggest that labetalol effectively attenuates the
systolic blood pressure and heart rate increases induced by repeated doses of
smoked cocaine, but does not alter subjective effects.
PMID- 10672978
TI - Changes in analgesia-producing mechanism of repeated cold stress loading in mice.
AB - Functional changes in opioid receptors involved in analgesia of repeated cold
stress (RCS)-loaded mice were investigated. The antinociceptive potency of
morphine (4 mg/kg, PO) was not affected in normal mice by norbinaltorphimine (10
mg/kg, SC), but treatment with this agent resulted in a lower level of morphine
induced antinociception in RCS-loaded animals. The antinociceptive activity of U
50488H (3 mg/kg, SC) was increased in RCS-loaded mice. In contrast to
hypersensitivity to U-50488H (1 and 10 microg, IT) noted in RCS-loaded mice, the
antinociception induced by DAMGO (0.1 and 1 microg, ICV) was reduced compared to
that of normal animals. Diazepam (1 mg/kg/day SC) was given during RCS loading,
and this agent prevented the development of hyperalgesia and the decrease in the
antinociceptive activity of DAMGO (1 microg, ICV) in RCS-loaded mice, but there
was no effect on the enhancement of the antinociceptive potency of U-50488H (10
microg, IT). These results indicate that the RCS-loaded mice were hyposensitive
to supraspinal mu-opioid receptor-mediated antinociception, whereas their
antinociceptive activities through kappa-opioid receptor in the spinal cord were
increased. Hypofunction of the supraspinal mu-opioid receptor due to anxiety may
explain the mechanism involved in the lowering of the nociceptive threshold in
RCS-loaded animals.
PMID- 10672979
TI - Pontine tegmentum lesions increase anxiety-like behavior in rats: a comparison
with anxiety produced by beta-CCE.
AB - Electrolytic lesions of the pedunculopontine tegmental nucleus (PPTg) have been
previously reported to increase anxiety-like behavior in rats. The aim of the
present study was to compare these behavioral changes with those produced by an
anxiogenic compound, the partial inverse agonist at benzodiazepine receptors,
beta-CCE. Three groups of rats, sham-lesioned treated with vehicle, sham-lesioned
treated with 10 mg/kg of beta-CCE, and PPTg-lesioned rats treated with vehicle,
were tested in the elevated plus-maze, the social-interaction test, and for
spontaneous locomotion. Histology showed that lesions were concentrated on the
caudal half of the PPTg. Measures of both the PPTg-lesioned and beta-CCE-treated
rats indicated increased anxiety-like behavior in the elevated plus-maze and in
the social-interaction test. Spontaneous locomotion, measured in the open- field
arena, did not differ between sham controls and PPTg-lesioned rats, but was
decreased in rats treated with beta-CCE. Our results confirmed that electrolytic
lesions of the caudal PPTg produce increased anxiety-like behavior. This behavior
is quantitatively and qualitatively similar to that produced by 10 mg/kg of beta
CCE.
PMID- 10672980
TI - Effects of adrenoceptor agents on apomorphine-induced licking behavior in rats.
AB - In the present study, intraperitoneal (IP) administration of the dopaminergic
receptor agonist apomorphine (0.1, 0.25, and 0.5 mg/kg) induced a dose-dependent
licking in rats. The intraperitoneal injection of the alpha1'''adrenoceptor
agonist phenylephrine (1-8 mg/kg) but not the alpha2-adrenoceptor agonist
clonidine (0.025-0.05 mg/kg) decreased licking induced by apomorphine. The alpha
adrenoceptor antagonists prazosin, phenoxybenzamine, and yohimbine also reduced
the apomorphine response significantly. The response induced by phenylephrine was
decreased by a dose of prazosin. The beta1-adrenenocepor agonist dobutamine and
beta2-adrenenocepor agonist salbutamol did not alter the apomorphine response.
However, beta2-adrenenocepor antagonists atenolol and propranolol reduced the
apomorphine effect. It may be concluded that alpha1- and possibly beta1
adrenoceptor mechanisms may be involved in modulation of licking behavior.
PMID- 10672981
TI - Ethanol, but not the anxiolytic drugs buspirone and diazepam, produces a
conditioned place preference in rats exposed to conditioned fear stress.
AB - The present study was designed to investigate the role of an anxiolytic effect in
the development of a drug-associated place preference in rats exposed to
conditioned fear stress, using the conditioned place-preference paradigm. The
administration of a low dose of ethanol (300 mg/kg, IP) and the anxiolytic drugs,
buspirone (1 and 2 mg/kg, IP) and diazepam (1.25 and 2.5 mg/kg, IP), did not
produce a place preference in rats that were not exposed to conditioned fear
stress. In rats that were exposed to conditioned fear stress, ethanol produced a
significant place preference, while buspirone and diazepam failed to produce a
place preference. In addition, ethanol, buspirone, and diazepam produced no place
preference in rats treated with an anxiogenic dose of pentylenetetrazole (20
mg/kg, IP). A significant decrease in locomotor activity was observed in rats
exposed to conditioned fear stress. Ethanol, but not buspirone and diazepam,
significantly recovered or increased locomotor activity in rats exposed to
conditioned fear stress. Further, the locomotor-stimulating effect of ethanol was
markedly enhanced by repeated exposure to conditioned fear stress. These results
suggest that the stimulating effect may be strongly related to the development of
the rewarding effect of a low dose of ethanol under psychological stress, and
that the conditioned place preference paradigm with conditioned fear stress may
be useful for studying the rewarding mechanism of ethanol with regard to the
interaction between ethanol and psychological stress.
PMID- 10672982
TI - Characterization of cocaine self-administration and pharmacokinetics as a
function of time of day in the rat.
AB - Two experiments examined the influence of time of day on the intravenous self
administration of cocaine and its associated pharmacokinetic profile in male
Sprague-Dawley rats. In both experiments, individual rats were randomly assigned
to experimental groups (n = 6/group) according to four selected times of day,
0100, 0700, 1300, and 1900 h, during which experimental procedures were
conducted. In both experiments, rats were maintained under a 12 L:12 D ambient
lighting cycle, with lights on at 0600 h. Training and testing was thus conducted
either 1 (0700, 1900) or 7 (1300, 0100 h) hours into the light and dark phases.
In Experiment 1, characteristics of cocaine self-administration across a
behaviorally active dose range were assessed. Statistically significant
differences were observed in the rates and patterns of self-administration across
the four experimental groups, most notably characterized by an apparent shift in
the dose of cocaine, which engendered peak rates of responding. Specifically,
groups tested at 0100 and 1300 h appeared to exhibit enhanced sensitivity to the
reinforcing properties of low-dose cocaine relative to groups tested at 0700 and
1900 h. The observed differences in apparent sensitivity of experimental subjects
to low-dose cocaine were not related in any simple way to ongoing patterns of
general locomotor activity, and were not accompanied by corresponding variance in
the pharmacokinetic profiles of cocaine when assessed over 1 h following an
intravenous infusion (1.8 mg/kg) at each of the four sampling periods noted
above.
PMID- 10672983
TI - Fear-potentiated startle response in mice: genetic analysis of the C57BL/6J and
DBA/2J intercross.
AB - The role of genetic factors in the fear-potentiated startle (FPS) response was
examined in the inbred C57BL/6J (B6) and DBA/2J (D2) mouse strains. Mice in the
D2 strain displayed a significant potentiation in the acoustic startle response
(ASR) when presented with a visual condition stimulus (CS) previously paired with
an aversive unconditioned stimulus (US). The maximal FPS response was observed
following 20 conditioning trials but a near maximal response was noted following
as few as five trials. Forty conditioning trials produced a significant reduction
in the FPS response that may be related to overtraining. The FPS response in the
B6 strain was significantly lower than the D2 strain, regardless of the number of
conditioning trials. The contrasting FPS responses were not related to
differences in auditory sensitivity known to exist between these strains.
Analysis of a full Mendelian cross formed from the B6 and D2 strains found that
the FPS response was a highly heritable trait, best described by a simple
additive model of inheritance and with a broad-sense heritability of 0.46. The
distribution of the FPS response in F2 hybrids formed from the intercross of the
D2 and B6 strains was continuous which suggests a multigenic substrate. The light
+ noise and noise-alone trial types were highly correlated, but no association
was detected between the baseline ASR amplitude and the FPS response. Mice from
the phenotypic extremes of the F2 distribution displayed FPS responses that were
more extreme than either of the progenitor strains. However, both baseline
startle amplitude and the salience of auditory stimuli did not differ in these
groups. The results of this study confirm an early report by Falls et al. (1997),
and provide additional quantitative genetics information necessary for the
eventual mapping of the chromosomal regions or genes associated with the FPS
response in mice.
PMID- 10672984
TI - 6-Chloro-3'-nitroflavone is a potent ligand for the benzodiazepine binding site
of the GABA(A) receptor devoid of intrinsic activity.
AB - 6-Chloro-3'-nitroflavone integrates a list of nearly 70 flavone derivatives
synthesized in our laboratories. The effects of 6-chloro-3'-nitroflavone on the
benzodiazepine binding sites (BDZ-BSs) of the GABA(A) receptor were examined in
vitro and in vivo. 6-Chloro-3'-nitroflavone inhibited the [3H]flunitrazepam
([3H]FNZ) binding to rat cerebral cortex membranes with a Ki of 6.68 nM and the
addition of GABA to extensively washed membranes did not modify its affinity for
the BDZ-BSs (GABA-shift = 1.16+/-0.12). The binding assays performed in rat
striatal and cerebellar brain membranes showed that this compound has similar
affinity to different populations of BDZ-BSs. Electrophysiological experiments
revealed that 6-chloro-3'-nitroflavone did not affect GABA(A)-receptors (GABA(A)
Rs) responses recorded in Xenopus oocytes expressing alpha1beta2gamma2s subunits,
but blocked the potentiation exerted by diazepam (DZ) on GABA-activated chloride
currents. In vivo experiments showed that 6-chloro-3'-nitroflavone did not
possess anxiolytic, anticonvulsant, sedative, myorelaxant actions in mice or
amnestic effects in rats; however, 6-chloro-3'-nitroflavone antagonized diazepam
induced antianxiety action, anticonvulsion, short-term, and long-term amnesia and
motor incoordination. These biochemical, electrophysiological, and
pharmacological results suggest that 6-chloro-3'-nitroflavone behaves as an
antagonist of the BDZ-BSs.
PMID- 10672985
TI - Facilitative effects of EGb 761 on olfactory recognition in young and aged rats.
AB - The aim of the present study was to evaluate the effects of chronic and acute
treatment by the Gingko biloba extract, EGb 761 (IPSEN, France) on olfactory
short-term memory in rats, using a spontaneous recognition procedure. The effects
of a daily EGb 761 treatment (30 or 60 mg/kg) over a period of 30 days
(Experiment 1) were evaluated in young male rats. Those of a single injection of
EGb 761 were assessed either in young male rats at 60 or 120 mg/kg (Experiment 2)
or in aged female rats at 60 mg/kg (Experiment 3). Results showed that, at the
highest dose (60 mg/kg), chronic EGb 761 treatment enhanced the recognition
performances, allowing recognition at delays at which control animals did not
show any recognition. Acute treatment enhanced recognition at both doses tested.
The results of the third experiment showed that EGb 761 had an overall
enhancement effect on the performances of aged rats. In summary, our results
provide evidence for a short-term memory enhancement effect of EGb 761 in both
young and aged rats.
PMID- 10672986
TI - Rewarding properties of testosterone in intact male mice: a pilot study.
AB - The present study examined the rewarding properties of 4-androsten-17beta-ol-3
one testosterone in intact male mice using the conditioned place preference (CPP)
technique. In Experiment 1, the pharmacokinetics of 0.8 and 1.2 mg/kg of
testosterone were studied to determine the most appropriate temporal interval to
test behavior. Additionally, the locomotor activity was recorded to control a
possible interfering effect on CPP. The maximum testosterone concentration was
registered at 45 min of administration, and no effects on activity were found. In
Experiment 2, three groups of male OF-1 mice received four pairings of the least
preferred compartment with testosterone (0.8, 1, or 1.2 mg/kg, SC) for 30 min. On
alternate days the preferred compartment was paired with vehicle for 30 min. The
control group received vehicle in both compartments. No significant differences
between groups were found in the time spent in the drug-paired compartment.
However, when separate analyses were performed in conjunction with the color of
the drug-paired compartment. CPP was observed only in animals pairing
testosterone/black compartment. These results suggest that rewarding properties
of testosterone treatment can be observed in male mice; these effects probably
being dependent on the environmental cues used as conditioned stimuli.
PMID- 10672987
TI - Mechanisms of chloroquine-induced body-scratching behavior in rats: evidence of
involvement of endogenous opioid peptides.
AB - Chloroquine is commonly used in the chemotherapy of malaria fever, and as an
antiinflammatory disease-modifying agent in patients with rheumatoid arthritis or
systemic lupus erythematosus. Administration of chloroquine (20.0 mg/kg IP)
significantly (p < 0.05) increased the frequency of body scratching in rats to
29.5+/-9 in 30 min, compared to saline control animals (6.5+/-2/30 min).
Morphine, a mu-opiate receptor agonist (1.0 mg/kg IP), potentiated the
chloroquine-induced rat body scratching to 40+/-6.6, while the mu-opiate receptor
antagonist, naltrexone (0.25 mg/kg, IP, given 15 min prior) blocked the
chloroquine induced body scratching to 4.5+/-2 (p < 0.05 ANOVA). In addition, the
frequency of chloroquine (20.0 mg/kg IP)-induced body scratching was
significantly reduced to 9.1+/-3 in 30 min in rats rendered tolerant to morphine
(p < 0.05 ANOVA) compared to the scratching frequency of 40+/-6.6 in morphine
naive rats. These suggests an involvement of mu-opioid receptors and/or
endogenous opioid peptides in chloroquine induced body scratching in rats.
Promethazine, a histamine-receptor antagonist (1.0 mg/kg IP, given 15 min prior
to chloroquine) and the corticosteroid, dexamethasone (1.0 mg/kg, IP, given 15
min prior) separately and significantly (p < 0.01) inhibited the chloroquine
induced scratching in rats, in a similar manner to clinical studies in malaria.
Collectively, the novel results implicate opioidergic mechanisms, and confirm the
efficacy of antihistamine and corticosteroids in chloroquine body scratching in
rats. It also strongly suggests that the chloroquine-induced body-scratching
behavior in the rat may be a useful experimental model for chloroquine-induced
pruritus in humans.
PMID- 10672988
TI - Anxiolytic-like effects of antidepressants after acute administration in a four
plate test in mice.
AB - The four-plate test (FPT) is an animal model of anxiety based on stress caused by
unconditioned fear. An increase of spontaneous punished behavior was used as a
measure to determine the anxiolytic effects of various antidepressants (ADs). In
the present study. ADs with different mechanisms of action, including tricyclics,
selective serotonin reuptake inhibitors (SSRIs), a monoamine oxidase inhibitor
(MAOI), and atypicals, were studied in the FPT to evaluate their anxiolytic-like
effects following acute administration. The number of punished crossings was
dramatically increased by the SSRIs citalopram, fluvoxamine, and paroxetine, but
not fluoxetine. The mixed 5-HT/NE reuptake inhibitors, milnacipran and
venlafaxine, also demonstrated strong antipunishment effects. The specific NE
reuptake inhibitors, desipramine and maprotiline, and the atypical AD trazodone,
enhanced freezing behavior, suggesting anxiogenic-like behavior. It was concluded
that, in the FPT, a model based on spontaneous response, where animals are
exposed to an aversive environment from which they can only escape by being
motionless, this kind of behavior might be related to anticipatory anxiety. In
this situation, ADs acting preferentially on 5-HT transmission possessed clear
anxiolytic like effects. The balance between the two transmitters, 5-HT and NE,
seemed to be a crucial factor.
PMID- 10672989
TI - Taurine blocks the glutamate increase in the nucleus accumbens microdialysate of
ethanol-dependent rats.
AB - During ethanol withdrawal, dramatic changes in the concentration of many
neurotransmitters may be responsible for many of the adverse effects. In the
present study, the technique of microdialysis was used to assay the changes in
excitatory and inhibitory amino acids after withdrawal from chronic ethanol
intoxication. Rats were made physically dependent on ethanol by vapor inhalation
for 4 weeks. The basal concentrations of both arginine and GABA were
significantly decreased in ethanol-dependent rats, although there were no
significant changes in any of the other amino acid basal concentration assayed
(i.e.. glutamate and taurine). During the first 12 h after withdrawal from
ethanol, only glutamate increased significantly (p < 0.05) at 6 h, and for the
duration of the study period of 12 h. To investigate whether either taurine and
ethanol interact with amino acids during ethanol withdrawal, two other ethanol
dependent groups were injected with a single intraperitoneal injection of either
taurine or ethanol 5 h after commencement of ethanol withdrawal. The IP injection
of ethanol (2 g/kg) significantly increased taurine microdialysate content, and
although this dose of ethanol was not able to block completely the increase of
glutamate release after ethanol withdrawal, a delayed decrease in glutamate
content was observed by the end of the period of the study (i.e., 11-12 h).
However, IP injection of taurine (45 mg/kg) significantly blocked the increased
glutamate release during ethanol withdrawal. This latter finding suggests that
taurine may interact with glutamate, possibly by inducing a blockade of glutamate
release during ethanol withdrawal.
PMID- 10672990
TI - Behavioral effects of GABA(A) receptor stimulation and GABA-transporter
inhibition.
AB - The present analysis addressed behavioral changes after treatment with 4.5 mg/kg
or 18.5 mg/kg of the GABA-uptake inhibitor tiagabine combined with either the
benzodiazepine diazepam (1.5 mg/kg) or the imidazopyridine zolpidem (0.05 mg/kg),
the latter two acting differentially on GABA(A) receptor subtypes. The study
included 97 male PVG/OIaHsd rats. A standard open field, an enriched open field,
and an elevated plus-maze was used to study rat behavior. Treatment with the low
dose of tiagabine alone induced no specific behavioral effects, whereas the high
dose had an anxiolytic-like potential. Furthermore, diazepam but not zolpidem
displayed anxiolytic-like effects. Combination of each benzodiazepine receptor
agonist with tiagabine at the low dose decreased explorative activity. Diazepam
plus the high dose of tiagabine increased the activity in the open-field test.
Zolpidem together with 18.5 mg/kg tiagabine had an angiogenic-like effect
compared to pure tiagabine treatment. These results provide evidence for a
pharmacodynamic interaction between the GABA-uptake inhibitor tiagabine and
diazepam or zolpidem. The interaction might be relevant in the clinic when
combining the anticonvulsant tiagabine and a benzodiazepine receptor agonist.
PMID- 10672991
TI - Long-lasting cytoprotection after pentadecapeptide BPC 157, ranitidine,
sucralfate or cholestyramine application in reflux oesophagitis in rats.
AB - Recently, the effectiveness of pentadecapeptide BPC 157 and other anti-ulcer
agents, called 'direct cytoprotection', was evidenced in totally gastrectomized
rats duodenum challenged with cysteamine 24 h after surgery, and sacrificed 24 h
after ulcerogen application. The further focus was on the possibility that this
effect could be seen over a more prolonged period (1, 2, 4 weeks), and in other
parts of the gastrointestinal tract (i.e. oesophagus). After the removal of the
stomach, the oesophagus and jejunum were joined by a termino-lateral anastomosis.
The animals were euthanized 7, 14 or 28 d after surgery, when oesophagitis was
blindly assessed both macroscopically (percentage of ulcerations areas) and
microscopically (percentage of areas of ulcers, regeneration and hyperplasia;
number of inflammatory cells - polymorphonuclear and mononuclear). Starting 24 h
after surgery, the medication was continuously given in the drinking water, in a
volume of 12.5 mL/rat daily, until euthanasia at the end of the observation
period, i.e. 7, 14, 28 d following surgery. Based on previous experiments, the
doses of agents were daily calculated per kg b.w. as follows: BPC 157 125 mg or
125 ng, cholestyramine 2.5 mg, ranitidine 125 mg, sucralfate 725 mg, whereas
controls received 72.5 mL x kg(-1) water. In support of these initial findings,
and considering gastrectomized acid-free rats as an ideal model for long-term
cytoprotective studies as well, pentadecapeptide BPC 157 markedly attenuated
termino-lateral oesophagojejunal anastomosis-reflux oesophagitis also over a
quite prolonged period. This efficacy was only partly shared by other anti-ulcer
agents. After 1-week-old oesophagitis (microscopical assessment), but not after 2
or 4 weeks, less damaged mucosa was noted in rats drinking ranitidine or
sucralfate compared to controls. Similar effectiveness was noted for
cholestyramine. The obtained results were supported also by inflammatory cell
assessment. Compared with control values, BPC 157-treated groups consistently
presented less polymorphonuclears and less mononuclears in all assessed periods.
Interestingly, the values obtained in other treated groups showed no difference
compared with control values. Thus, despite limitations, a generalization
supporting a direct importance of a common cytoprotective approach, could be
clearly provided. A useful, long-lasting cytoprotective activity (apparently more
prominent in BPC 157 rats, than in reference agents, ranitidine, sucralfate, as
well as cholestyramine) may be a likely suitable therapy in otherwise resistant
reflux oesophagitis conditions.
PMID- 10672992
TI - The effect of pentadecapeptide BPC 157, H2-blockers, omeprazole and sucralfate on
new vessels and new granulation tissue formation.
AB - A clear protection of the gastrointestinal tract and an evident anti-inflammatory
effect were shown for a novel stomach pentadecapeptide BPC 157 (i.p./i.g.) in
comparison with several reference standards in various ulcer models along with a
protection of endothelium and particular interaction with the NO-system. Thus, we
evaluated whether this pentadecapeptide along with other gastroprotective agents
could affect angiogenesis and the healing process in vivo using a procedure
initially described by Szabo and co-workers. In each rat, two sterile sponges (1
x 1 x 0.25 cm; V = 0.25 mL) with the same quantities of BPC 157 (10 ng x mL(-1),
10 microg x mL(-1), 50 microg x kg(-1)) or reference agents (cimetidine: 10, 100,
500 mg x mL(-1); ranitidine: 2.5, 25, 250 mg x mL(-1); famotidine: 10, 50, 100 mg
x mL(-1); omeprazole: 10, 50, 100 mg x mL(-1); sucralfate: 1, 5, 10 mg x mL(-1)
were implanted subcutaneously in the lumbar region. The sponges were removed
after 3 or 7 d, fixed in formalin, and processed for histologic and histochemical
evaluation and morphometry assessment. Compared with the control values, the
number of newly formed endothelial spaces inside newly formed granulation tissue
was markedly increased in all animals treated with BPC 157, cimetidine,
ranitidine, famotidine, sucralfate and omeprazole, a consistent finding noted
after either 3 or 7 d. Compared with control values, markedly more granulation
tissue was noted in the rats in the groups of animals treated with BPC 157 (50
microg) and in the rats treated with sucralfate in all dosages used, euthanized
after 3 d. In all groups treated with H2-blockers however, similar values to
those of controls were noted. Thus, it could be concluded that an evident
angiogenic property was consistently noted for the novel pentadecapeptide BPC
157, H2-blockers (cimetidine, famotidine and ranitidine) and omeprazole, besides
the well known angiogenic effect of sucralfate. Furthermore, unlike H2-blockers
and omeprazole, BPC 157 stimulates the formation of granulation tissue,
suggesting a particular activity, similar to that previously noted for
sucralfate.
PMID- 10672993
TI - Difference between the effect of acute and chronic surgical vagotomy on the
cytoprotective action of atropine against indomethacin-induced mucosal lesions on
the gastrointestinal tract in rats.
AB - The cytoprotective effect of a small dose of atropine was proved against the
indomethacin (IND)-caused gastrointestinal (GI) mucosal damage. This protective
effect of atropine disappeared in the acute phase of surgical vagotomy (ASV) on
the vagally-innervated parts of GI tract. The aims of our observations were: 1)
to examine the effect of chronic surgical vagotomy (CSV) on the cytoprotective
action of atropine in the GI tract; and 2) to compare the effects of ASV and CSV
on the GI cytoprotection caused by atropine against IND-induced mucosal damage
and vascular permeability in rats. The IND was given s.c. 24 h prior to the
killing of the animals in a dose of 20 mg x kg(-1). Bilateral surgical vagotomy
or sham operation were carried out 24 h (ASV) or 14 d (CSV) before IND
application. Atropine was given i.p. every 5 h after IND-treatment in a dose of
0.1 mg x kg(-1). The number of macroscopical mucosal ulcerations was noted and
its severity was calculated by semiquantitative scale in the stomach, small
intestine and three equal parts of colon. Vascular permeability was measured by
Evans-blue leakage into the mucosal tissue. It has been found that: 1) Tte small
dose of atropine significantly decreased the IND-induced mucosal damage and
vascular permeability on the stomach, small intestine and the vascular
permeability on the proximal colon; 2) the small dose of atropine did not cause
any changes in the appearance of IND-induced mucosal lesions and in Evans blue
concentration in the mucosa after ASV, but it significantly decreased the IND
caused mucosal damage and Evans blue concentration in the mucosa of stomach,
small intestine and proximal colon after CSV; 3) the IND-induced mucosal damage
and vascular permeability treated with atropine (given in cytoprotective dose)
were significantly smaller after CSV than that after ASV on the stomach, small
intestine and proximal colon. It has been concluded that the intact vagal nerve
has an essential role in the appearance of cytoprotective mechanisms of atropine
in GI tract.
PMID- 10672994
TI - Detrimental effects of oestradiol on cysteamine-induced gastroduodenal ulceration
in the female rat.
AB - The actions of the female sex steroid, oestradiol on cysteamine-induced mucosal
ulceration has been evaluated in female Wistar rats. Administration of cysteamine
(400 mg x kg(-1), s.c.) provoked macroscopic gastroduodenal mucosal injury
(assessed planimetrically) and an increase in microvascular permeability
(assessed by the extravasation of radiolabeled albumin) in the stomach and
duodenum, determined 24 h later. Ovariectomy (2 weeks before cysteamine) reduced
gastroduodenal macroscopic injury, and albumin extravasation following cysteamine
challenge. Administration of oestradiol (1-5 mg x kg(-1), as an i.m. depot 1 week
before cysteamine) dose-dependently augmented gastric and duodenal macroscopic
mucosal lesions and microvascular permeability provoked by cysteamine. These
findings indicate that oestradiol can exacerbate gastroduodenal ulceration and
microvascular injury.
PMID- 10672995
TI - Effects of pectin-induced passive linkage of gastric H+ on the gastric acid
secretion on the development of ethanol- and salicylate-induced gastric mucosal
lesions in rats.
AB - The aim of this study was to evaluate the effects of intragastrically given
pectin-induced physicochemical properties and actions on active gastric acid
secretion and on the development of ethanol- and aspirin-induced gastric mucosal
lesions. The observations were carried out on CFY-strain rats, fasted for 24 h
before the experiments with water ad libitum. The observations were carried out
in two experimental series. A) The gastric mucosal lesions were produced by
intragastrically given 96% ethanol or aspirin prepared with 0.2 M HCl. Different
doses of pectin (100, 50 and 25 mg x kg(-1), respectively) were administered
intragastrically 30 min before giving necrotizing agents. The number of gastric
lesions was noted 1 h after the administration, while the severity of gastric
mucosal lesions was scored by semi-quantitative scale. B) The effects of pectin
were studied on the volume and H+ secretion of the stomach in 4-h pylorus-ligated
rats. It has been found that: 1) the gastric mucosal lesions could be produced in
100% of rats by the application of both necrotizing agents. 2) Pectin in doses of
50-100 mg x kg(-1) increased the number of gastric mucosal lesions in both
models, while no increase was produced by the application of 25-mg x kg(-1) dose.
3) The severity of mucosal lesions increased significantly after the
administration of all doses of pectin. 4) The pectin-induced increase of gastric
lesions (number) showed a dose-response effect. 5) The pectin produced a
significant increase in the volume of gastric secretion and gastric H+ secretion.
It has been concluded that: a) pectin-induced physicochemical changes are able to
enhance the aggression to gastric mucosa produced by ethanol and aspirin; b) a
positive correlation exists between the linkage of H+ to pectin and significant
active metabolic response in the rat stomach; c) pectin alone stimulates the
active metabolic process of the gastric H+ secretion.
PMID- 10672996
TI - Pentadecapeptide BPC 157 attenuates gastric lesions induced by alloxan in rats
and mice.
AB - A diabetogenic alloxan regimen produced lesions in all stomachs of treated
animals, either rats (200 mg x kg(-1) s.c.) or mice (400 mg x kg(-1) i.p.). In
control animals, the lesions, when developed (i.e. 24 h following application),
appear to be quite sustained, and consistently present also after 1 or 2 weeks.
The application of the pentadecapeptide BPC 157 (10 microg or 10 ng x kg(-1) i.p.
coadministered together with alloxan) would significantly attenuate these
lesions' appearance. This beneficial effect seems to be present in either rats or
mice and in either of the tested intervals. Importantly, the beneficial effect
seems to be shared by both microgram and nanogram regimens.
PMID- 10672997
TI - A behavioural study of the effect of pentadecapeptide BPC 157 in Parkinson's
disease models in mice and gastric lesions induced by 1-methyl-4-phenyl-1,2,3,6
tetrahydrophyridine.
AB - The effect of a stomach pentadecapeptide, BPC 157, on Parkinson's disease in mice
was investigated, along with its salutary activity on stomach lesions induced by
parkinsongenic agents. Parkinsongenic agents, 1-methyl-4-phenyl-1,2,3,6
tetrahydropyridine (MPTP) (30.0 mg x kg(-1)b.w. i.p. once daily for 6d, and after
4d once 50.0 mg x kg(-1)b.w. i.p.) or reserpine (5.0 mg x kg(-1)b.w. i.p.) were
applied i.p. BPC 157 (1.50 microg or 15.0 ng x kg(-1)b.w. i.p.) was applied 15
min before or alternatively 15 min after each MPTP administration. In reserpine
studies, BPC 157 (10.0 microg or 10.0 ng x kg(-1)b.w. i.p.) was given either 15
min before reserpine or in the already established complete catalepsy 24 h
thereafter. BPC 157 strongly improved the MPTP-impaired somatosensory orientation
and reduced the MPTP-induced hyperactivity, and most importantly, MPTP-motor
abnormalities (tremor, akinesia, catalepsy -otherwise very prominent in saline
control), leading to almost complete abolition of otherwise regularly lethal
course of MPTP treatment in controls. Likewise, in reserpine experiments, BPC 157
strongly prevented the development of otherwise very prominent catalepsy and when
applied 24 h thereafter reversed the established catalepsy. In addition, a
reduction of reserpine-hypothermy (BPC 157 pre-treatment) and reversal of further
prominent temperature fall (BPC 157 post-treatment) have been consistently
observed. Taking together these data, as the two most suitable animal models were
consistently used and since the high effectiveness was demonstrated in pre- and
post-treatment, microg and ng regimens, BPC 157 as an organoprotector should be
further therapeutically investigated. Additionally, given in either regimen,
pentadecapeptide BPC 157 strongly attenuated the stomach lesions in mice that
otherwise consistently appeared in mice treated with the parkinsogenic neurotoxin
MPTP.
PMID- 10672998
TI - Characteristics of Chi distribution on different bacterial genomes.
AB - The availability of full genome sequences provides the bases for analyzing global
properties of the genetic text. For example, oligonucleotide sequences that are
over- or underrepresented can be identified by taking into account the overall
genome composition and organization. One of the most overrepresented
oligonucleotides in Escherichia coli is the Chi site, an octanucleotide that
stimulates DNA repair by homologous recombination. Here we analyze the genomic
distribution of Chi in E. coli and in the three other bacteria where a Chi
sequence has been identified; note that Chi is a different sequence in each
organism. For each bacterial genome, Chi sequences are frequent, regularly
distributed, and overrepresented. This suggests that selection for Chi may have
occurred during evolution to favor efficient repair of a damaged chromosome.
Other characteristics of Chi distribution are not conserved and might reflect
specific features of DNA repair in each host. The different sequence and
characteristics of Chi in each microorganism suggest that selection for Chi
occurred independently in different bacteria.
PMID- 10672999
TI - Trinucleotide repeats and other microsatellites in yeasts.
AB - Microsatellites are direct tandem DNA repeats found in all genomes. A particular
class of microsatellites, called trinucleotide repeats, is responsible for a
number of neurological disorders in humans. We review here our current state of
knowledge on trinucleotide repeat instability, and discuss the molecular
mechanisms that may be involved in trinucleotide repeat expansions leading to
fatal diseases in humans. We also present original data on microsatellite
distribution in several microbial genomes, and on the use of microsatellites as
physical markers to accurately and easily genotype yeast strains.
PMID- 10673000
TI - DNA uptake signal sequences in naturally transformable bacteria.
AB - The naturally transformable bacterium Haemophilus influenzae Rd contains 1471
copies of the DNA uptake signal sequence (USS) 5'-AAGTGCGGT in its genome.
Neisseria meningitidis contains 1891 copies of the USS sequence 5'-GCCGTCTGAA.
The USSs are often found in the base paired stem of transcription terminators.
PMID- 10673001
TI - Occurrence and structure-function relationship of pentameric short sequence
repeats in microbial genomes.
AB - It is suggested that genomes found in any form of cellular life contain
potentially size-variable repetitive DNA moieties. In eukaryotes, large
proportions of the multi-chromosomal genome consist of various classes of
repetitive DNA. Also in archaeal genomes, repetitive DNA is encountered and, as
is the case for the eukaryotes as well, little or no function is at present
attributable to most of it. For prokaryotes, elegant experiments have highlighted
so-called slipped strand nucleotide mispairing (SSM) as a basic and causal
mechanism, giving rise to repeat unit number variation at a distinct locus.
Illegitimate base pairing in regions of repetitive DNA during replication, in
association with defective DNA repair and enhanced nuclease susceptibility of
replication intermediates, in the end gives rise to deletion or addition of
repeat units. Prokaryotic short sequence repeats (SSRs) harbour arrays of short
repeat units, between one and approximately 20 nucleotides in length. SSRs are
involved in various mechanisms of microbial gene expression regulation. Promoter
strength can be affected by altering the spacing between important structural
domains as can the integrity of open reading frames. In the present communication
the literature on microbial SSRs harbouring repeat units that are five
nucleotides in length will be briefly reviewed. Examples of these SSRs with
discrete functionality are encountered in bacterial species such as Haemophilus
influenzae, Neisseria gonorrhoeae, and Pasteurella haemolytica. In addition,
several of the currently known bacterial and archaeal whole genome sequences were
scanned for the presence of novel examples of potential five-nucleotide SSRs (and
others) in order to gather additional knowledge on the propensity and putative
functions of this type of potential genetic switch.
PMID- 10673003
TI - Super-integrons.
AB - Integrons represent the primary mechanism for antibiotic resistance gene capture
and dissemination among gram-negative bacteria. The recent finding of super
integron (SI) structures in the genomes of several bacterial species has expanded
their role in genome evolution. The Vibrio cholerae superintegron is gathered in
a single chromosomal super-structure harbouring hundreds of gene cassettes. The
encoded functions, when identifiable, are linked to adaptations extending beyond
antibiotic resistance and pathogenicity. Comparison of the cassette contents of
super-integrons from remote Vibrio species suggests that most of their cassettes
are species-specific. Many bacterial species belonging to several distinct genera
of the gamma- and beta-proteobacteria undoubtedly carry or show strong evidence
for the presence of chromosomal SIs. If each bacterial species harbouring a SI
has its own cassette pool, the resource in terms of gene cassette availability
may be immense.
PMID- 10673004
TI - Novel intergenic repeats of Escherichia coli K-12.
AB - An online catalog of intergenic DNA repeat sequence elements is added to the
EcoGene Escherichia coli K-12 genome sequence annotation and analysis project
(bmb.med.miami.edu/EcoGene). A library of noncoding (intergenic) DNA sequences
depleted of known intergenic repeat classes was searched for DNA sequence
similarities to identify novel DNA repeat sequence classes.
PMID- 10673002
TI - Short palindromic repetitive DNA elements in enterobacteria: a survey.
AB - We present a survey of short palindromic repetitive elements in enterobacteria.
Seven families are presented. Five were already known (RSA, IRU, 29-bp repeats,
BIMEs and boxC), and their properties are updated; in particular, a new composite
element is shown to include the formerly identified boxC repeats. Two
repetitions, YPAL1 and YPAL2, found primarily in Yersinia, are described here for
the first time.
PMID- 10673005
TI - Large genomic sequence repetitions in bacteria: lessons from rRNA operons and Rhs
elements.
AB - The rrn operons and Rhs elements provide starkly contrasting examples of the
evolution and interaction of large sequence repetitions in bacteria. Genomic
sequencing of different species as well as comparative sequencing of independent
isolates is providing provocative insights into previously obscure issues.
PMID- 10673006
TI - IS elements as constituents of bacterial genomes.
AB - We provide here an overview of our present understanding of the distribution of
different insertion sequences (ISs) within bacterial genomes (both chromosomes
and plasmids). This is at present fragmentary and a significant effort is needed
in the analysis of the increasing number of genomes whose sequence has been
determined. We also consider some of the properties of ISs which are important in
their role of assembling, reassorting, and transmitting groups of genes.
PMID- 10673007
TI - Paralogous genes encoding transport proteins in microbial genomes.
AB - The largest superfamilies of prokaryotic genes encode transport proteins, but
many transporters are encoded by orphan genes or those that comprise very small
families. We have analyzed eighteen completely sequenced prokaryotic genomes for
paralogous transport systems and have thereby identified 76 permease families. In
this short review, we present and discuss the paralogues in some of these
families and interpret the most prominent results, particularly those relevant to
the largest permease superfamilies.
PMID- 10673008
TI - DNA repeats and archaeal nucleosome positioning.
AB - Archaeal histones, homologs of the eucaryal nucleosome core histones, have been
identified in the Euryarchaeota. They assemble as tetramers with dsDNA to form
archaeal nucleosomes that resemble the central structure of the eucaryal
nucleosome formed by the histone (H3-H4)2 tetramer. Eucaryal and archaeal
nucleosomes assemble preferentially on DNA molecules that best accommodate the
severe bends found within these structures, and here we discuss the relationships
between archaeal and eucaryal nucleosomes, repeating DNA sequences, and
nucleosome positioning.
PMID- 10673009
TI - Short repeats and IS elements in the extremely radiation-resistant bacterium
Deinococcus radiodurans and comparison to other bacterial species.
AB - Computer analysis of the complete genome of Deinococcus radiodurans R1 has shown
that the number of insertion sequences (ISs) and small noncoding repeats (SNRs)
it contains is very high, and comparable with those of Escherichia coli. IS
elements and several families of SNRs are described, together with their possible
function in the D. radiodurans genome.
PMID- 10673010
TI - Functional and evolutionary roles of long repeats in prokaryotes.
AB - Most recently published complete bacterial genomes have revealed unexpectedly
high numbers of long strict repeats. In this article we discuss the various
functional and evolutionary roles of these repeats, focusing in particular on
their role in terms of genome stability, gene transfer, and antigenic variation.
PMID- 10673011
TI - Repeated sequences in bacterial chromosomes and plasmids: a glimpse from
sequenced genomes.
AB - To gain insight into the extent of exact DNA repeats in sequenced bacterial
genomes and their plasmids, we analyzed the collection of completely sequenced
bacterial genomes available at GenBank using the program Miropeats. This program
draws graphical representations of exact DNA repeats in whole genomes. In this
work, we present maps showing the extent and type (inverted or direct) of exact
DNA repeats longer than 300 bp for the whole collection. These repeats may
participate in a variety of events relevant for bacterial genome plasticity, such
as amplifications, deletions, inversions, and translocations (via homologous
recombination), as well as transposition. Additionally, we review recent data
showing that high-frequency architectural variations in genomic structure occur
at both the interspecies and interstrain levels.
PMID- 10673012
TI - Tandem repeats in complete bacterial genome sequences: sequence and structural
analyses for comparative studies.
AB - A series of complete bacterial genome sequences have recently become available
and powerful methods have been developed for the identification of tandem repeats
on a very large scale. It is thus possible to derive extensive comparative
descriptions of such repeats at the level of complete genomes, as illustrated
here for three different bacterial genomes: Escherichia coli, Haemophilus
influenzae, and Mycobacterium tuberculosis. Such sequence analyses can be
usefully complemented by structural characterisations of the repeats.
PMID- 10673013
TI - Recognition of regulatory sites by genomic comparison.
AB - Availability of complete bacterial genomes opens the way to the comparative
approach to the recognition of transcription regulatory sites. Assumption of
regulon conservation in conjunction with profile analysis provides two lines of
independent evidence making it possible to make highly specific predictions.
Recently this approach was used to analyze several regulons in eubacteria and
archaebacteria. The present review covers recent advances in the comparative
analysis of transcriptional regulation in prokaryotes and phylogenetic
fingerprinting techniques in eukaryotes, and describes the emerging patterns of
the evolution of regulatory systems.
PMID- 10673014
TI - Three views of microbial genomes.
AB - We describe here GenomeAtlases as a method for visualising three different
aspects of complete microbial chromosomes: repeats, DNA structural
characteristics, and base composition. We have applied this method to all
publicly available genomes, and find a general strand preference of global
repeats. The atlas for the Mycoplasma genitalium genome is presented as an
example, and results from all three views are consistent with known
characteristics of the genome.
PMID- 10673015
TI - Promoter sequences and algorithmical methods for identifying them.
AB - This paper presents a survey of currently available mathematical models and
algorithmical methods for trying to identify promoter sequences. The methods
concern both searching in a genome for a previously defined consensus and
extracting a consensus from a set of sequences. Such methods were often tailored
for either eukaryotes or prokaryotes although this does not preclude use of the
same method for both types of organisms. The survey therefore covers all methods;
however, emphasis is placed on prokaryotic promoter sequence identification.
Illustrative applications of the main extracting algorithms are given for three
bacteria.
PMID- 10673016
TI - Synthesis, characterization, and platelet adhesion studies of novel aliphatic
polyurethaneurea anionomers based on polydimethylsiloxane-polytetramethylene
oxide soft segments.
AB - Two novel aliphatic polyurethaneurea anionomers were synthesized based on
polydimethylsiloxane (PDMS)-polytetramethylene oxide (PTMO) soft segments. The
hard segments consisted of either 4,4'-methylene dicyclohexyl diisocyanate
(H12MDI), sulfonic acid-containing diol and 1,4-butandiol (BD) or H12MDI,
carboxylic acid-containing diol and BD. The nonionic counterpart chain extended
with BD was prepared. In addition, the base nonionic polyurethaneurea containing
a pure PDMS soft segment, which is denote H-D-BD, was also studied for
comparison. The effects of soft segment type and ion incorporation on the
physical properties, surface properties, and plateled adhesion are discussed. The
ionic polyurethaneureas exhibited poor phase separation, a smaller fraction of
PTMO present at the surface, and a smaller contact angle. On the other hand, it
also showed a larger fraction of PDMS present at the surface and a higher water
absorption value than its nonionic counterpart. H-D-BD had more phase-separated
structure, a larger fraction of PDMS present at the surface, and larger contact
angle but lower water absorption value than the PTMO-containing
polyurethaneureas. The in vitro platelet adhesion experiments indicated that the
ionic groups, especially for carboxylate, and surface enrichment PDMS soft
segment could effectively inhibit platelet adhesion.
PMID- 10673017
TI - Inhibition by heparin and derivatized dextrans of Staphylococcus epidermidis
adhesion to in vitro fibronectin-coated or explanted polymer surfaces.
AB - The ability of Staphylococcus aureus to recognize several extracellular matrix or
plasma proteins (e.g., fibrinogen, fibronectin, and collagen) promotes bacterial
attachment to artificial surfaces. Whereas most S. aureus clinical isolates
elaborate a wide repertoire of bacterial surface receptors' called adhesins,
exhibiting specific binding of individual host proteins, S. epidermidis is
lacking most of such protein adhesins. To document the interactions between S.
epidermidis and various surface-adsorbed proteins, we first compared promotion of
bacterial attachment by seven purified human proteins immobilized onto
poly(methyl methacrylate) (PMMA) coverslips. Only two of them, namely fibronectin
and fibrinogen, exhibited adhesion-promoting activities. In the presence of
native heparin or two functionalized dextrans (CMDBS for Carboxy Methyl,
Benzylamide sulfonate/sulfate), a dose-dependent inhibition of S. epidermidis
adhesion to fibronectin-coated, but not to fibrinogen-coated surfaces was
observed. The inhibitory effects of each CMDBS were much stronger than that of
native heparin. In contrast, a control highly negatively charged, dextran
exclusively substituted with carboxy methyl groups exerted no inhibition on S.
epidermidis adhesion. To evaluate how CMDBS could interfere with S. epidermidis
attachment to coverslips coated in vivo with extracellular matrix components, we
also tested PMMA surfaces retrieved from tissue cages subcutaneously implanted in
guinea pigs. Each CMDBS, but not heparin, strongly inhibited S. epidermidis
adhesion to explanted coverslips, even in the presence of tissue cage fluid. In
conclusion, fibronectin plays an important role in promoting S. epidermidis
attachment to implanted biomaterials. Furthermore, S. epidermidis adhesion to
fibronectin-coated or implanted biomaterials can be efficiently blocked in vitro
by CMDBS.
PMID- 10673018
TI - Immobilization of invertase in conducting thiophene-capped
poly(methylmethacrylate)/polypyrrole matrices.
AB - Immobilization of invertase in thiophene-capped
poly(methylmethacrylate)/polypyrrole matrices was achieved by constant potential
electrolysis using different supporting electrolytes. Optimum reaction conditions
such as substrate concentration, temperature, and pH for the enzyme electrodes
were determined. The temperature and pH were found to be 60 degrees C and 4.8,
respectively. The effect of supporting electrolyte on the enzyme activity
revealed that SDS was the best in the immobilization procedure. Michaelis-Menten
constant and the maximum reaction rate in PMMA/PPy matrices were of the order of
that of pristine polypyrrole. However, in terms of repeated use, the copolymer
matrices were superior to polypyrrole.
PMID- 10673019
TI - Solubility control of enzymes by conjugation with stimulus-responsive polymers.
AB - For development of bio-reactor enzymes stimuli-responsive polymers have been
employed as immobilizing matrices. The stimuli-responsive polymers have been used
for solubility control in water. Recently we first succeeded in the solubility
control in organic media by conjugation with photo-responsive polymer. The
polymer-conjugated enzymes can efficiently catalyze various chemical reactions in
the soluble state and can be recovered by precipitation in response to the
stimulation. In this review, the conjugation method and recent progress is
described.
PMID- 10673020
TI - Pulsatile peptide release from multi-layered hydrogel formulations consisting of
poly(ethylene glycol)-grafted and ungrafted dextrans.
AB - Multi-layered hydrogel formulations consisting of poly(ethylene glycol)-grafted
dextran (PEG-g-Dex) and ungrafted Dex were investigated as a model of pulsatile
drug release. In these formulations, it is considered that the grafted PEG
domains act as a drug reservoir dispersed in the Dex matrix based on aqueous
polymer two-phase systems. The formulations exhibited surface-controlled
degradation by dextranase, and insulin release was observed in a pulsatile manner
because of the multi-layered structure: PEG-g-Dex hydrogel layers containing
insulin and insulin-free Dex hydrogel layers. Thus, it is suggested that the
multi-layered hydrogel formulations using PEG-g-Dex and Dex are feasible for
chronopharmacological drug delivery systems.
PMID- 10673021
TI - Effects of long-term sub-lethal concentrations of dental monomers on THP-1 human
monocytes.
AB - Studies have shown that monomers from dental resins are acutely cytotoxic, but
little is known of their long-term effects at sub-lethal concentrations. The
current study determined the long-term effects of sub-lethal concentrations of
TEGDMA (triethyleneglycol dimethacrylate) and Bis-GMA (bisphenol
glycidylinethacrylate), two common dental monomers, on the in vitro cellular
proliferation, succinic dehydrogenase activity, and total cellular protein
production of monocytes. Human THP-1 monocytes were exposed to concentrations of
100, 200, and 400 micromol l(-1) of TEGDMA or 1, 5, and 25 micromol l(-1) Bis-GMA
for 5 weeks. Controls received only vehicle solutions of ethanol. Each week
cellular proliferation (hemocytometer), succinic dehydrogenase (SDH) activity
(MTT) and total cellular protein (bicinchoninic acid) were assessed. The results
were compared with ANOVA and Tukey intervals (alpha = 0.05). TEDGMA had no
proliferative or cellular protein effects, but increased SDH activity 20-60% in
week 1 (p < 0.05). SDH activity then decreased 40% in week 2, followed by a
gradual increase of 30-40% over week 3-5 (p < 0.05). Bis-GMA reduced
proliferation by 40-60% from 1-5 weeks exposure (p < 0.05). However, SDH activity
and total protein per cell were not affected. There was some indication of
increased SDH activity after 5 weeks (20-30%, p < 0.05). Sub-lethal
concentrations of TEGDMA and Bis-GMA have significant long-term effects on
monocytes at low-dose 5-week exposures in vitro. Each monomer acted differently.
PMID- 10673022
TI - Effect of acetylation of biodegradable polyrotaxanes on its supramolecular
dissociation via terminal ester hydrolysis.
AB - Acetylation of biodegradable polyrotaxanes was examined to estimate the effect on
its supramolecular dissociation via terminal ester hydrolysis. The biodegradable
polyrotaxanes, in which many alpha-cyclodextrins (alpha-CD) are threaded onto a
poly(ethylene glycol) chain capped with L-phenylalanine via ester linkages, were
acetylated using acetic anhydride; alpha-CD release behavior was then
characterized by in vitro hydrolysis. The degree of acetylation was changed by
the concentration of acetic anhydride and the reaction time. The results of the
in vitro hydrolysis indicate that the critical degree of acetylation to prolong
supramolecular dissociation lies at around 30%. The terminal hydrolysis proceeded
completely even with 100% of acetylation. These findings suggest that the
hydrophobization of alpha-CDs in the polyrotaxane makes it possible to delay the
time to complete the supramolecular dissociation. The hydrophobization of the
polyrotaxane is of great importance for designing implantable materials that
maintain their supramolecular structure until tissue regeneration with complete
terminal hydrolysis.
PMID- 10673023
TI - FTIR spectroscopic investigation and modeling of solute/polymer interactions in
the hydrated state.
AB - Attenuated total reflectance infrared spectroscopy was used to investigate
possible interactions during transport of oxprenolol x HCl, bovine serum albumin,
alpha-chymotrypsin, and fibrinogen through poly(acrylic acid) and its random
copolymeric gels. Carbonyl and carboxylate ion peak shifts were used to identify
drug/gel binding due to electrostatic and hydrogen bond interactions between the
polymer carrier and the drugs tested. These findings were used to interpret the
decrease in calculated diffusion coefficients of drugs diffusing through these
gels and the associated hindering of drug transport. A model was developed to
analyze this transport process as a function of the binding heat of the drug with
the polymer.
PMID- 10673024
TI - The mouse aldehyde oxidase gene: molecular cloning, chromosomal mapping and
functional characterization of the 5'-flanking region.
AB - In this article, we report on the chromosome mapping and molecular cloning of the
genetic locus encoding the mouse molybdo-iron/sulfur-flavoprotein aldehyde
oxidase. The aldehyde oxidase locus maps to mouse chromosome 1 band C1-C2, as
determined by fluorescence in situ hybridization experiments conducted on
metaphase chromosomes. The gene is approximately 83 kb long and consists of 35
exons. The exon/intron boundaries are perfectly conserved relative to the
corresponding human homolog and almost completely conserved relative to the mouse
xanthine oxidoreductase gene. This further supports the concept that the aldehyde
oxidase and xanthine oxidoreductase loci evolved from the same ancestral
precursor by a gene duplication event. The position of a major transcription
start site was defined by primer extension and RNase mapping analysis. The 5'
flanking region of the mouse aldehyde oxidase gene contains a functional and
orientation-dependent promoter as well as several putative binding sites for
known cell-specific and general transcription factors. Deletion analysis of the
5'-flanking region defines an approximately 470 bp DNA stretch which is necessary
and sufficient for the transcription of the mouse aldehyde oxidase gene.
PMID- 10673025
TI - A second-site mutation at glutamate-257 that restores the function of the mutant
yeast ribosomal protein L5 containing lysine-270,271-->arginine.
AB - A genetic approach was used to identify interacting regions of yeast ribosomal
protein L5 (also known as L1, L1a, or YL3). Previous studies from our laboratory
showed that residues K270 and K271 in protein L5 are essential for its function.
The mutant L5 protein in which both residues were replaced by arginine residues
(K270,271R) exhibited about 80% RNA binding capability compared to the wild-type
and the mutant protein was assembled into the 60S ribosomal subunits in vivo. The
yeast strain expressing this mutant protein in a homozygous form was lethal
(Biochim. Biophys. Acta 1308 (1996) 133-141). In the present study, this non
functional mutant was used to select intragenic suppressors. A spontaneous,
intragenic suppressor which contained an E257K substitution (in addition to the
primary mutations) was identified. The suppressor protein bound about 60% of
yeast 5S rRNA in vitro compared to the wild-type. To gain more insight into the
nature of the intragenic suppressor, additional mutant proteins in which E257 was
substituted by a variety of amino acids were produced by site-directed
mutagenesis. The ability of each mutant protein to bind yeast 5S rRNA in vitro
and to suppress the lethal effect of the double K270,271 mutation in vivo were
examined. Results suggest communication between two non-contiguous domains on
protein L5 and that several factors, such as electrostatic interaction and
hydrogen bonding are likely to play a role in this global communication. Mutation
studies on E257 alone also reveal that substitutions of this residue in L5
protein could affect cell growth under specified conditions, but a variety of
changes could be tolerated without serious deleterious effects. We propose a
working model in which E257 is located in a loop and the dynamic as well as the
flexibility of this loop is important for L5 function.
PMID- 10673026
TI - The influence of the exocyclic pyrimidine 5-methyl group on DNAse I cleavage and
sequence recognition by drugs.
AB - Incorporation of modified nucleotides into DNA, using the PCR, has allowed us to
probe the influence that the exocyclic 5-methyl group of pyrimidines has on DNAse
I cleavage and sequence recognition by drugs. The results show that removal of
the methyl group from the major groove, made possible by substituting uridine for
thymidine, allows DNAse I to cleave more readily at AT-rich regions compared to
normal DNA. By contrast, addition of an extra methyl group, contrived by
substituting 5-methylcytidine for normal cytidine, allows DNAse I to cleave more
readily at GC-rich regions compared to normal DNA. In the cutting pattern of DNA
containing both uridine and 5-methyl cytosine, we find the cleavage
characteristics of both the single-substituted DNA species combined. Thus, the
presence or absence of the exocyclic 5-methyl group in the major groove has a
strong influence on the relative intensity of cleavage of phosphodiester bonds by
DNAse I. These nucleotide substitutions can also influence the sequence-selective
binding of drugs to DNA. Whereas removal of the methyl group (replacement of T
with U) generally has little effect on sequence recognition by a variety of
drugs, addition of a methyl group (replacement of C with M) generates new binding
sites for some intercalators, namely daunomycin, DACA and SN16713.
PMID- 10673027
TI - Mapping of eukaryotic DNA topoisomerase I catalyzed cleavage without concomitant
religation in the vicinity of DNA structural anomalies.
AB - Sensitive sites for covalent trapping of eukaryotic topoisomerase I at DNA
structural anomalies were mapped by a new method using purified enzyme and
defined DNA substrates. To insure that the obtained topoisomerase I trapping
patterns were not influenced by DNA sequence variations, a single DNA
imperfection was placed centrally within a homonucleotide track. Mapping of
topoisomerase I-mediated irreversible cleavage sites on homopolymeric DNA
substrates containing mismatches showed trapping of the enzyme in several
positions in close vicinity of the DNA imperfection, with a strong preference for
the 5' junction between the duplex DNA and the base-pairing anomaly. On
homopolymeric DNA substrates containing a nick, sites of topoisomerase I-mediated
cleavage on the intact strand were located just opposite to the nick and from one
to ten nucleotides 5' to the nick. Sites of enzyme-mediated cleavage next to a
nick and an immobile single-stranded branch were located 5' to the strand
interruption in distances of two to six nucleotides and two to ten nucleotides,
respectively. Taken together these findings suggest that covalent trapping of
topoisomerase I proceeds at positions adjacent to mismatches, nicks and single
stranded branches, where the cleavage reaction is allowed and the ensuing
ligation reaction prevented. In principle, the developed interference method
might be of general utility to define topoisomerase-DNA interactions relative to
different types of structural anomalies.
PMID- 10673028
TI - Tumor promotion resistant cells are deficient in AP-1 DNA binding, JunD DNA
binding and JunD expression and form different AP-1-DNA complexes than promotion
sensitive cells.
AB - The JB6 cell culture model is used to identify molecular determinants of
susceptibility to the promotion of neoplastic transformation. Clonal variants
susceptible to transformation ('P+' cells) form numerous anchorage-independent
colonies in soft agar upon treatment with the phorbol ester tumor promoter TPA,
whereas resistant variants ('P-' cells) do not. We now report that there is
significantly less binding of activator protein-1 (AP-1) to its DNA binding site
in P- cells than in P+ cells. Gel supershift assays were performed to detect
association of all seven AP-1 family members with their DNA binding site in TPA
treated and -untreated P+ and P- cells. Significantly lower DNA binding and
protein expression of JunD were detected in P- cells than in P+ cells. c-Jun was
detected in P+, but not P-, AP-1-DNA complexes, and c-Fos was detected in P-, but
not P+, AP-1-DNA complexes. These and other phenotype-specific differences in
abundance and composition of AP-1-DNA complexes may play a role in the resistance
of P- cells to tumor promoter-induced transformation.
PMID- 10673029
TI - Characterization of the Azoarcus ribozyme: tight binding to guanosine and
substrate by an unusually small group I ribozyme.
AB - We report novel chemical properties of the ribozyme derived from the smallest
group I intron (subgroup IC3) that comes from the pre-tRNA(Ile) of the bacterium
Azoarcus sp. BH72. Despite the small size of the Azoarcus ribozyme (195
nucleotides (nt)), it binds tightly to the guanosine nucleophile (Kd = 15 +/- 3
microM) and exhibits activity at high temperatures (approximately 60-70 degrees
C). These features may be due to the two GA3 tetraloop interactions postulated in
the intron and the high GC content of the secondary structure. The second order
rate constant for the Azoarcus ribozyme, ((k(cat)/Km)S = 8.4 +/- 2.1 x 10(-5) M(
1) min(-1)) is close to that found for the related ribozyme derived from the pre
tRNA(Ile) of the cyanobacterium Anabaena PCC7120. pH dependence studies and
kinetic analyses of deoxy-substituted substrates suggest that the chemical
cleavage step is the rate-determining process in the Azoarcus ribozyme. This may
be due to the short 3-nt guide sequence-substrate pairing present in the Azoarcus
ribozyme. Finally, the Azoarcus ribozyme shares features conserved in other group
I ribozymes including the pH profile, the stereospecificity for the Rp
phosphorothioate at the cleavage site and the 1000-fold decrease in cleavage rate
with a deoxyribonucleoside leaving group.
PMID- 10673030
TI - Scanning gene expression during neuronal cell death evoked by nerve growth factor
depletion.
AB - Depletion of nerve growth factor (NGF) from differentiated, neuronal PC12 cells
causes a form of programmed cell death that stems from the attenuation of NGF
receptor signaling and the resultant expression of certain genes required for
cell death. To better understand the associated molecular events, we surveyed the
changes in gene expression in PC6-3 cells, a subline of PC12, caused by depletion
of NGF. Using restriction landmark cDNA scanning, we assessed the expression
patterns of as many as 15,000 gene species, and 30 genes were isolated whose
expression was altered in the absence of NGF. Of the 20 genes up-regulated in the
absence of NGF, including transcription factor LRF-1/ATF3, most were also up
regulated during the programmed death of cortical neurons caused by Ca2+
ionophore. Their function may thus be a general feature of programmed neuronal
cell death. In contrast, with one exception, expression of down-regulated genes
was NGF-dependent and therefore diminished in the absence of NGF but unaffected
by Ca2+ ionophore. These findings confirm that global investigation of the
features of up- and down-regulated genes should add substantially to our
understanding of the regulation of programmed neuronal cell death and the
mechanisms involved.
PMID- 10673031
TI - Identification of novel isoforms of human RAD52.
AB - In yeast, RAD52 has been shown to be essential for homologous recombination of
DNA and to be involved in the repair of double-stranded DNA breaks. Recently, the
human homologue of yeast RAD52, a 418-amino-acid protein, has been identified. In
this study, we report three different isoforms of human RAD52 isolated from brain
and testis cDNA libraries. cDNAs of these isoforms contain distinct insertions
and encode truncated proteins due to translational frame-shifts. The three
isoforms consist of 226-, 139-, and 118-amino-acid residues, and are designated
as RAD52beta, gamma, and delta, respectively. The original RAD52 is termed as
RAD52alpha in this paper. Messages of these isoforms have been detected in
various human tissues. We found that the RAD52 isoforms were unable to interact
with RAD52alpha because of partial defect of the self-interaction domain.
Furthermore, like RAD52alpha, the isoforms have been shown to bind to both single
stranded and double-stranded DNA. These results suggest that RAD52beta, gamma,
and delta might affect RAD52alpha function through their DNA-binding property and
their inability to bind to RAD52alpha. Thus, these isoforms might act as dominant
negative mutants or negative regulators of RAD52alpha.
PMID- 10673032
TI - Structure and genomic organization of porcine RACK1 gene.
AB - The cDNA encoding porcine RACK1 protein was isolated from porcine spleen cDNA
library. The deduced protein sequence of porcine RACK1 cDNA shows that it
contains 317 amino acid residues, and shares nearly 100% identity with its
vertebrate counterparts. Noticeably, the RACK1 protein was differentially
expressed in various porcine tissues. High expression of RACK1 protein was
observed in the tissues including thymus, pituitary, spleen and liver, whereas
there was no detectable expression in muscle. The genomic DNA of porcine RACK1
with approximate 7.5 kb was constructed by both polymerase chain reaction
amplification and genomic library screening. It consists of eight exons
intervened by seven introns, and most of the intron/exon splice sites conform to
the GT/AG rule. The promoter region contains functional serum response element,
YY1-like binding site and AP1 site, which is supported by the finding that the
expression of RACK1 gene in cultured porcine ST cells has a serum response as
well as a TPA response.
PMID- 10673033
TI - Three structurally and functionally conserved Hlx genes in zebrafish.
AB - For the Hlx class, which includes homeodomains (HD) that are similar to
Drosophila H2.0, few members have been identified in vertebrates. In this report,
we describe three zebrafish genes, hlx1, hlx2 and hlx3, related to the murine Dbx
genes. The proteins encoded by hlx1 and hlx2 have about the same sequence
identity to Dbx1 (approximately 60%), suggesting that they derive from a
duplication in the fish lineage. This is supported by similarities in the
embryonic expression patterns and promoter sequence conservation. The zebrafish
Hlx3 protein is related to murine Dbx2, but it is apparently too diverged to be
orthologous. Our phylogenetic analysis of all the known HD sequences of the Hlx
class also shows that it can be divided into at least two distinct families. All
the Dbx-like genes have similar expression in the embryonic nervous system.
However, the initial expression patterns of the zebrafish hlx genes are quite
unique, suggesting that some functional divergence has occurred between fish and
mammals.
PMID- 10673034
TI - Quantitative analysis reveals differential expression of mucin (MUC2) and
intestinal trefoil factor mRNAs along the longitudinal axis of rat intestine.
AB - MUC2 and intestinal trefoil factor (ITF) are considered to have important roles
in intestinal mucosal protection and epithelial repair. In order to investigate
whether these genes are co-ordinately expressed, we have used competitive reverse
transcription-polymerase chain reaction assays to measure MUC2 and ITF mRNA
levels in human intestinal cell lines and along the longitudinal axis of rat
intestine. ITF mRNA was expressed in several intestinal cell lines. However, MUC2
mRNA was detected only in LS174T cells where it was present at approx. 25-fold
lower levels than the ITF transcript. In contrast, in rat intestinal tissues,
MUC2 mRNA levels were generally higher than ITF mRNA levels. The levels of both
transcripts increased markedly during postnatal development. In adult rats, the
expression patterns of MUC2 and ITF mRNAs along the longitudinal axis of the
small intestine were similar, with lowest levels in the proximal duodenum and
relatively constant levels in the other regions assayed. In contrast, the
expression patterns of MUC2 and ITF in different regions of the large intestine
showed a marked divergence. Our results strongly suggest that expression of the
MUC2 and ITF genes is not coordinately regulated in intestinal cells.
PMID- 10673035
TI - Structure of the Xenopus laevis TFF-gene xP4.1, differentially expressed to its
duplicated homolog xP4.2.
AB - TFF-peptides (formerly P-domain peptides, trefoil factors) represent major
secretory products of mucous epithelia in mammals and amphibia. The nucleotide
sequence of a large portion of a gene encoding the TFF-peptide xP4.1 from Xenopus
laevis and its genomic organization were determined in the present study. The
peptide xP4.1 containing four TFF-domains is thought to represent the functional
frog homolog of human TFF2 (formerly hSP). The xP4.1 gene analyzed spans a region
of about 7 kb and consists of six exons. Each TFF-domain is encoded by a single
exon flanked by type 1 introns typical of shuffled modules. The 5'-upstream
region contains a TATA-box, and potential binding sites for hepatocyte nuclear
factor 3 and AP-1. Furthermore, the cDNA sequence of a transcript named xP4.2
with 91% similarity to xP4.1 is presented. RT-PCR analysis revealed that xP4.1
and xP4.2 genes are differentially expressed. xP4.1 transcripts are detectable
only in the stomach, but not in the esophagus, whereas xP4.2 transcripts are
found both in the esophagus and in the stomach with a descending gradient from
fundus to antrum.
PMID- 10673036
TI - Activation of Smad1-mediated transcription by p300/CBP.
AB - Smad1 is the intracellular effector of bone morphogenetic proteins (BMPs), a
growth factor family well known to stimulate bone and cartilage formation. Smad1
becomes phosphorylated by the cognate BMP transmembrane receptor protein kinases,
associates with the common mediator Smad4 and translocates to the nucleus where
it is involved in regulation of gene transcription. In this report we demonstrate
that Smad1 interacts with the paralogous coactivators p300 and CBP both in vitro
and in vivo. The N- and C-termini of Smad1 negatively interfere with binding to
p300/CBP, and the C-terminal half of Smad1 harbors two interaction domains both
binding to the same region near the C-terminus of p300/CBP. We show that Smad1 as
well as a Gal4 fusion with the C-terminal half of Smad1 stimulate gene
transcription in a cooperative fashion with p300/CBP. Phosphorylation of Smad1
enhances its binding to CBP and thereby further stimulates Smad1-dependent
transcription. These results provide a mechanism how phosphorylated Smad1
regulates gene activity by interaction with p300/CBP, and factors associated with
these bridging coactivators.
PMID- 10673037
TI - Molecular cloning and characterization of the mouse histone deacetylase 1 gene:
integration of a retrovirus in 129SV mice.
AB - Reversible histone acetylation plays an important role for chromatin structure
and gene expression. The acetylation state of core histones is controlled by
histone acetyltransferases and histone deacetylases. Here we report the cloning
and characterization of the mouse histone deacetylase 1 (HDAC1) gene. The mouse
genome contains several HDAC1-related structures representing the HDAC1 gene and
at least three pseudogenes. The HDAC1 gene comprises 14 exons ranging from 49 to
539 bp. Interestingly the murine HDAC1 gene strongly resembles the previously
published mouse HDAC2 gene (Zeng et al., J. Biol. Chem. 273 (1998) 28921-28930).
The sizes of ten of the 14 exons are identical for both genes and the splicing
sites for 11 introns align in identical positions suggesting a gene duplication
event. The HDAC1 gene is located only 128 bp downstream from the MARCKS-related
protein (MRP) gene in a tail-to-tail orientation. The murine MRP gene was
previously mapped to a conserved gene cluster on chromosome 4 sharing linkage
homology to human chromosome 1p32-36. The genes for HDAC1 and MRP are co
expressed in a variety of cell types. In the genome of 129SV mice the largest
intervening sequence of the HDAC1 gene, intron 3, harbors a complete copy of the
endogenous retrovirus MuERV-L. In contrast the HDAC1 gene in other mouse strains
such as C57B16, C3H/An and C-RY lacks the retrovirus. Our study provides useful
tools for future targeted gene disruption studies.
PMID- 10673038
TI - The stem hairpin loop structure of p2Sp1 RNA is required for RNA-cleaving
activity.
AB - We studied the hairpin-loop structure of an RNA fragment (GUUUCGUACAAAC) (R13)
with the sequence corresponding to the self-cleavage domain in the precursor of
an RNA molecule from bacteriophage T4-infected Escherichia coli cells (p2Sp1
RNA). In order to determine the influence of the hairpin-loop structure on these
sequence-specific cleavage reactions, we have synthesized oligoribonucleotides
containing hairpin-loop, double-helical stem-loop, and single-stranded RNA
structures. The cleavage was affected by the hairpin-loop structure. Furthermore,
the helix-stem, which retains the thermodynamically extrastable stem hairpin-loop
structures, is also important for the cleavage activity. However, the
thermodynamically extrastable helix-stem structure reduced the cleavage activity
of the adjacent UA and CA sequences at the helix-stem site. For the cleavage
reactions of the RNA cleavage products, the R6 (ACAAAC), R7 (GUUUCGU), and R9
(GUUUCGUAC) mers from the parent RNA, R13 (GUUUCGUACAAAC), a very slight amount
of cleavage product (2%) from the RNA 9 was observed, but no reaction occurred
for the R6 and R7. We also describe the influences of the sequences (UA and CA)
on the cleavage activity.
PMID- 10673039
TI - Characterization of the 5'-flanking region of the gene encoding bovine adenylate
kinase isozyme 3.
AB - We have characterized the 5'-flanking region of the gene encoding bovine
adenylate kinase isozyme 3 (AK3). S1 mapping analysis revealed multiple
transcription start points in the bovine AK3 gene. The promoter activities were
tested in HeLa cells using the chloramphenicol acetyltransferase (CAT) gene as a
reporter. The CAT analysis showed that the basal promoter sequence was located
within the region from -189 to +228. In the presence of short DNA fragments of
the 5'-flanking region as competitors, the transcriptional activity of the bovine
AK3 promoter changed depending on the fragments used. The results identified the
basal regulatory elements in the proximal promoter region.
PMID- 10673040
TI - Characterization of the full-length sequences of phospholipase A2 induced during
flower development.
AB - The suppression subtractive hybridization (SSH) method was used to isolate
developmentally regulated genes during carnation flower maturation. Carnation
flower maturation-related clones obtained by the SSH were serially assigned as
CFMI (carnation flower maturation-induced) clones. Northern blot analysis showed
that several CFMI clones were differentially expressed during flower development.
One of the clones, CFMI-3, showed similarity to various animal secretory
phospholipases A2 (PLA2). Since little is known about PLA2 gene sequence in plant
species, the CFMI-3 clone was selected for further characterization by sequence
analysis. Full sequence analysis reveals that the CFMI-3 contains a Ca2+ binding
domain, a PLA2 active site, and 12 conserved Cys residues, which is a distinct
characteristic of PLA2. Amino acid sequence alignment of CFMI-3 to various
putative plant PLA2 confirmed that the CFMI-3 cDNA is the full-length putative
PLA2 cDNA identified in plant species.
PMID- 10673041
TI - Molecular cloning of two bovine aquaporin-4 cDNA isoforms and their expression in
brain endothelial cells.
AB - Two cDNA isoforms of bovine aquaporin-4 (bAQP4-A and bAQP4-B) were newly
isolated. Sequence analysis of both cDNAs revealed open reading frames of 972
(bAQP4-A) and 906 nucleotides (bAQP4-B) with deduced proteins of 323 (bAQP4-A)
and 301 amino acid residues (bAQP4-B). Partial 5'-genomic sequence analysis
showed that the 5'-noncoding sequences specific to bAQP4-A and -B transcripts
were contained in distinct exons, exon 0 for bAQP4-A and new exon X for bAQP4-B.
RNase protection assay demonstrated the definite expression of both isoforms in
bovine brain. The deduced amino acid sequence of bAQP4-A was highly homologous to
the human (97%), rat (95%), and mouse (93%) AQP4. Reverse transcription-PCR
detected the expression of AQP4 mRNAs in bovine brain endothelial cells as well
as in a variety of bovine organs such as brain, lung, spleen, and kidney.
Northern blot analysis indicated that a 6.0 kb message is predominantly expressed
in bovine brain and lung.
PMID- 10673042
TI - Cloning and characterization of the unusual cyclin gene from an amphidiploid of
Nicotiana glauca-Nicotiana langsdorffii hybrid.
AB - Cyclins play an important role in the regulation of cell cycle progression in
eukaryotic cells. As an aid to understanding the molecular nature of unregulated
cell proliferation, a cDNA clone encoding a cyclin gene, GTcyc, was identified
from genetic tumors. The clone contained 1095 bp including a 24 base poly(A)
tail. GTcyc is an unusual cyclin gene, distantly related to mammalian cyclin D
genes having 21-25% identity within the cyclin box. Northern blots showed that
the genetic tumors express high levels of GTcyc relative to non-tumor hybrid
tissues. Southern analysis suggests that GTcyc may be contained one or two
families in genetic tumors.
PMID- 10673044
TI - Cloning and characterisation of the rpoS gene from plant growth-promoting
Pseudomonas putida WCS358: RpoS is not involved in siderophore and homoserine
lactone production.
AB - The rpoS gene which encodes a stationary phase sigma factor has been identified
and characterised from the rhizosphere-colonising plant growth-promoting
Pseudomonas putida strain WCS358. The predicted protein sequence has extensive
homologies with the RpoS proteins form other bacteria, in particular with the
RpoS sigma factors of the fluorescent pseudomonads. A genomic transposon
insertion in the rpoS gene was constructed, these mutants were analysed for their
ability to produce siderophore (iron-transport agent) and the autoinducer quorum
sensing molecules called homoserine lactones (AHL). It was determined that RpoS
was not involved in the regulation of siderophore and AHL production, synthesis
of these molecules is important for gene expression at stationary phase. P.
putida WCS358 produces at least three different AHL molecules.
PMID- 10673043
TI - Cloning and characterization of a novel human gene encoding a zinc finger protein
with 25 fingers.
AB - This study reports cloning and characterization of a human cDNA encoding a novel
human zinc finger protein, ZFD25. ZFD25 cDNA is 6118 bp long and has an open
reading frame of 2352 bp that encodes a 783 amino acid protein with 25 C2H2-type
zinc fingers. The ZFD25 cDNA also contains a region with high sequence similarity
to the Kruppel-associated box A and B domain in the 5'-untranslated region,
suggesting that ZFD25 belongs to the Kruppel-associated box zinc finger protein
family. The ZFD25 gene was localized to chromosome 7q11.2. Northern blot analysis
showed that ZFD25 was expressed in a wide range of human organs. In cultured
endothelial cells, the mRNA level was decreased upon serum starvation.
PMID- 10673045
TI - Cloning and expression profile of mouse and human genes, Rnf11/RNF11, encoding a
novel RING-H2 finger protein.
AB - The RING finger (C3HC4-type zinc finger) is a variant zinc finger motif presents
in a new family of proteins. A new member of the RING finger family was
identified and its cDNA structures were determined in human and mouse. The
predicted protein consisting of a 144 amino acid residues is very conservative
between the two species and contains a canonical RING-H2 finger motif (C3H2C2) at
the carboxyl-terminal region. The genes were designated as RNF11/Rnf11 for RING
finger protein 11. A single 2.4-kb transcript of mouse Rnf11 was ubiquitously
expressed in various fetal and adult mouse tissues by the Northern blot analysis.
The human RNF11 gene was mapped on chromosome 1p31-p32 region, where frequent
alterations have been observed in T-cell acute lymphoblastic leukemia.
PMID- 10673046
TI - Characterization of a new ATP-binding cassette transporter in Trypanosoma cruzi
associated to a L1Tc retrotransposon.
AB - We have characterized the tcpgp1-like gene of Trypanosoma cruzi, a new ATP
binding cassette (ABC) transporter. tcpgp1 codes for a 1035 amino acid protein
with a considerable homology to LtpgpA of Leishmania. Tcpgp1 lacks the conserved
sequences corresponding to the second nucleotide-binding domain of other ABC
transporters due to the insertion of the L1Tc non-LTR retrotransposon.
PMID- 10673047
TI - A novel TNF-inducible message with putative growth suppressor function.
AB - We report the nucleotide sequence of a novel cDNA and TNF-induced expression of
the corresponding message (mRNA) in human fibroblast cells. This message is also
expressed in certain human tumor cell lines and is over-expressed in a colon
cancer cell line (HT-29). NIH3T3 cells transfected with the antisense construct
of the 5'-region of this novel cDNA formed 20-fold more colonies in culture
compared to cells transfected with a sense construct of the same region or the
sense and the antisense constructs of the central region of this cDNA. This
observation suggests a possible growth suppressor function for the gene
represented by this cDNA.
PMID- 10673048
TI - Calcyclin is differentially expressed in rat testicular cells.
AB - Immature rat Sertoli cells aggregate and form tubule-like structures when
cultured on a monolayer of peritubular myoid cells. In this study, differential
gene expression of monocultures and direct cocultures of peritubular cells and
Sertoli cells were examined. One of the cDNA clones isolated showed high homology
to calcyclin and a microvascular differentiation gene, CEC5, which was reported
to be highly homologous to CASK, a membrane-associated guanylate kinase homolog.
Sequencing and mRNA analysis of rat calcyclin demonstrated that the gene was
differentially expressed and was found only in peritubular cells and cocultures
with increased levels. In contrast, CASK was expressed by Sertoli cells,
peritubular cells, and cocultures, whereas CEC5 was never found in the testicular
somatic cells. Our findings point to a paracrine regulation of calcyclin
expression in testicular peritubular fibroblasts which seems to be related to
tubular growth.
PMID- 10673049
TI - Molecular characterisation of In51, a class 1 integron containing a novel
aminoglycoside adenylyltransferase gene cassette, aadA6, in Pseudomonas
aeruginosa.
AB - Polymerase chain reaction-amplification and subsequent sequencing of the variable
region of a novel integron, In51, from Pseudomonas aeruginosa revealed the
presence of a novel aminoglycoside adenylyltransferase gene, aadA6, together with
an open reading frame of unknown function, orfD. AADA6 enzyme has only 75% amino
acid identity with AADA1 and is able to confer high level resistance to
streptomycin and spectinomycin in Escherichia coli.
PMID- 10673050
TI - Cloning, expression and characterization of a novel human Ras-related protein
that is regulated by glucocorticoid hormone.
AB - Ras proteins are a family of guanine nucleotide (GDP and GTP)-binding proteins
that play central roles in essential signal transduction pathways. We have
isolated in a yeast two-hybrid screen a human cDNA encoding a new protein that is
highly homologous (98% identical at the protein level) to mouse DexRas1, a member
of the Ras superfamily. The human DexRas1 is expressed in a variety of tissues
including heart, brain, placenta, lung, liver, skeletal muscle, kidney and
pancreas, with the strongest expression in the heart. Using human fibrosarcoma HT
1080 cells as a model system, we show that the expression of human DexRas1 is
stimulated by dexamethasone, suggesting a role of human DexRas1 in dexamethasone
induced alterations in cell morphology, growth and cell-extracellular matrix
interactions.
PMID- 10673051
TI - Genetic analysis of the gene cluster responsible for synthesis of serotype e
specific polysaccharide antigen in Actinobacillus actinomycetemcomitans.
AB - A gene cluster associated with the biosynthesis of the serotype e-specific
polysaccharide antigen (SPA) of Actinobacillus actinomycetemcomitans IDH1705
belonging to serotype e was cloned and sequenced. This cluster consisted of 18
open reading frames. Escherichia coli produced the polysaccharide that reacts
with the serotype e-specific antiserum when transformed with a plasmid containing
the cluster. Comparing the structure of the gene cluster with similar clusters
from A. actinomycetemcomitans strains Y4 (serotype b) and NCTC9710 (serotype c)
revealed that a 5.3-kb region containing the distal half of one gene and two
entire genes in the cluster from strain IDH1705 replaced a 6.2-kb region
containing eight genes in the cluster from strain Y4, and a 4.7-kb region
containing four genes in the cluster from strain NCTC9710. These results suggest
that this region is essential to the antigenic specificity of serotype e A.
actinomycetemcomitans.
PMID- 10673052
TI - cDNA cloning and gene expression of three small GTP-binding proteins in defense
response of chickpea.
AB - The cDNA clones encoding rab type (INR134 and ELR19) and rac type (ELR26) small
GTP-binding proteins were isolated from Ascochyta rabiei-inoculated chickpea
leaves and the elicitor-treated cell cultures. Rac type ELR26 showed enhanced
expression in inoculated leaves indicating correlation with the defense response.
PMID- 10673053
TI - Characterisation and quantification of earthworm cyclophilins: identification of
invariant and heavy metal responsive isoforms.
AB - We report the identification of two earthworm cyclophilin genes, which resemble
the cytosolic cyclophilin-A and the signal sequence containing cyclophilin-B.
Using fully quantitative PCR we were able to assess the transcript regulation of
both cyclophilin isoforms, as well as a further independent control gene (actin),
during exposure to heavy metals. Whilst the expression of cyclophilin-B and actin
remained exceptionally constant, cyclophilin-A was up-regulated 38-fold. This
intriguing observation has profound implications regarding cyclophilin's use as
an invariant control and highlights the fact that it is essential to treat
cyclophilin isoforms as separate entities, rather than one functional unit.
PMID- 10673054
TI - Experimental trials with a thermostable Newcastle disease virus (strain I2) in
commercial and village chickens in Tanzania.
AB - Antibody responses in indigenous village and commercial chickens vaccinated with
12 thermostable Newcastle disease (ND) vaccine and protection levels against
challenge with a virulent field isolate were determined. The antibody response of
village chickens vaccinated by eye drop revealed that 30, 60 and 90 days after
primary vaccination, the mean log2 HI titres were 6.1, 5.4 and 3.6, respectively,
whereas for commercial chickens, the antibody response after 14, 30 and 90 days
were 8.2, 5.1 and 4.2, respectively. Village chickens vaccinated orally via
drinking water had mean log2 HI titres of 3.4 after 30 days. After booster
vaccination, the mean HI titre was 5.4 and 3.3 after 30 and 60 days post
secondary vaccination (i.e. 60 and 90 days after primary vaccination). Antibody
response of mean log2 HI titres of 2.6 was recorded 30 days after primary
vaccination orally through food; 30 and 60 days after secondary vaccination (i.e.
60 and 90 days after primary vaccination), mean log2 HI titres were 5.3 and 3.2,
respectively. All commercial and village chickens vaccinated by eye drop survived
the challenge trial whereas village chickens vaccinated through drinking water
and food had protection levels of 80% and 60% 30 days after primary vaccination,
respectively. However, 30 days after booster vaccination, the protection level
was 100%. At 60 days after secondary vaccination, the protection level dropped
again to 80% for chickens vaccinated orally. All control chickens used in the
challenge trials developed clinical ND and died 3-5 days after inoculation with
the virulent virus. Supported by laboratory findings, I2 strain of NDV seemed to
be avirulent, immunogenic and highly protective against virulent isolates of NDV.
It may be a suitable vaccine to use in village chickens to vaccinate them against
ND in rural areas.
PMID- 10673055
TI - Incidence risk and clinical features of retention of foetal membranes in ewes in
28 flocks in southern Greece.
AB - In a field investigation of 28 flocks in southern Greece, 7660 lambings were
monitored. Retention of foetal membranes (defined as failure to expel the foetal
membranes within 6 h of lambing the last lamb) was recorded in 92 ewes. The
median within-flock incidence risk was 1.25% (range: 0-1.9%). The heterogeneity
of the risk among flocks was not significant (p = 0.99); no correlation was found
between the incidence risk and the flock size (r(sp) = 0.33, p = 0.09). Overall,
the median duration of retention was 72 h (range: 9-288 h); it did not differ
among flocks (p = 0.89) and was not correlated with flock size (r(sp) = 0.24, p =
0.27). During the initial stage of retention the membranes were fleshy and humid;
the cotyledons were thick and congested. Progressively, the membranes became
thin, dry and stringy; the cotyledons shrunk and were pale. Finally the membranes
dropped as a mass. In ewes with retention for >12 h, a variety of accompanying
signs was recorded: straining (in 22% of the ewes with retention), vulval oedema
and reddening (in 16%), anorexia (in 13%), recumbency (in 13%) and increased
temperature (in 12%) were the most frequent ones. Overall, the median clinical
score of the disorder was '2' (range: '1'-'5'); it did not differ among flocks (p
= 0.98) and was not correlated with flock size (r(sp) = 0.26, p = 0.25). In 4% of
the ewes with retention for <4 days accompanying signs were recorded (median
clinical score: '2'), whilst in 80% of the ewes with retention for > or =4 days
accompanying signs were recorded (median clinical score: '3'). This difference in
the prevalence of clinical signs was significant (p < 0.0001).
PMID- 10673056
TI - Parents' predicted transmitting abilities are not associated with culling prior
to second lactation of Michigan, USA dairy cows.
AB - The objective of this study was to test the association between parents'
predicted transmitting abilities (PTAs) for milk, fat and protein and subsequent
culling of heifers during rearing or first lactation. The data from 1992 to 1996
consisted of the culling outcome of 5619 Michigan Holstein heifers during rearing
or first lactation, and the heifers' parents' PTAs from the period in which the
heifers were born. Fixed-effect probit models (both dichotomous and ordered)
estimated the relationships between culling and parents' PTAs. Herd effect was
modeled as a fixed-effect. There was no association between PTAs of milk, fat,
and protein for each heifer's parents and subsequent culling of the heifer during
rearing or first lactation. Weak evidence for the necessity of modeling the herd
effect as fixed was present. The lack of association between parents' PTAs and
reason-specific culling (voluntary versus involuntary)--coupled with the counter
intuitive effects of parents' PTAs on the probability of being culled for each of
the reasons--raised questions about the utility of classifying culling reasons
according to the voluntary nature of the culling decision. We concluded that
Michigan producers are not using parents' genetics in heifer-culling decisions.
PMID- 10673057
TI - Herd-based monitoring for tuberculosis in extensive swedish deer herds by culling
and meat inspection rather than by intradermal tuberculin testing.
AB - The effect of random slaughter and meat inspection as a tool to detect or
eradicate tuberculosis in large, extensive deer herds in Sweden was evaluated. A
computer spreadsheet model based on the Reed-Frost method was developed. Numbers
of new infections and of infected deer slaughtered as well as probability of
detecting tuberculosis or slaughtering all infected deer in a herd, were
simulated. The model predicted that, given a 20% annual slaughter and that
disease was introduced with one infected deer, the infection would be detected or
eliminated in most herds (90%) after 15 years.
PMID- 10673058
TI - Lung-tissue extract as an alternative to serum for surveillance for brucellosis
in chamois.
AB - Serological surveys are the most-used way to study diseases in free-ranging wild
animals. However, the difficulty in obtaining a sufficient number of suitable
serum samples is a major problem. To resolve this problem, we investigated the
possibility of using lung-tissue extract in place of blood serum for searching
for antibodies against Brucella abortus. Antibodies titres against B. abortus was
tested from blood serum and lung-tissue extract from 112 chamois and 99 cattle.
Although in complement-fixation-test, lung-tissue extract titres usually were one
to three-fold lower than serum titres, there was a good agreement between serum
and lung-tissue extract positivity both in chamois and in cattle. The lung-tissue
extract appears a suitable resource in monitoring brucellosis in chamois.
PMID- 10673059
TI - Influence of new infection with bovine virus diarrhoea virus on udder health in
Norwegian dairy cows.
AB - A retrospective longitudinal study was conducted to examine whether the exposure
of dairy herds to bovine virus diarrhoea virus (BVDV) affected udder health. All
Norwegian dairy herds that had experienced a marked increase in the BVDV antibody
titres in bulk milk (from a level corresponding to an optical density (OD) <0.25
to >0.55, as determined by an indirect enzyme-linked immunosorbent assay) between
two nation-wide herd screening examinations carried out late in 1992 and 1993,
respectively, were considered to have been exposed to BVDV during the period
between the examinations. The reference group included all dairy herds in which
the bulk milk was BVDV antibody-negative or had only very low titres of BVDV
antibodies (OD <0.25) each year from 1992 to 1995. The annual incidence rate of
clinical mastitis, the bulk-milk somatic-cell count, and the annual rate of
culling because of mastitis in the herds, were compared in the year of BVDV
exposure (1993) as well as in a period prior to exposure (from 1988 to 1992) and
two years following the year of exposure. In herds exposed to BVDV, there was a
7% increase in the incidence rate of clinical mastitis in the year of exposure,
as compared with the nonexposed herds. No significant changes attributable to
BVDV exposure were observed in the bulk-milk somatic-cell count or in the rate of
culling because of mastitis.
PMID- 10673060
TI - Isolation and characterization of cholic acid 7alpha-dehydroxylating fecal
bacteria from cholesterol gallstone patients.
AB - BACKGROUND/AIMS: The development of cholesterol gallstones, in some patients, has
been associated with increased proportions of deoxycholic acid in the bile acid
pool. Deoxycholic acid is a microbial product of cholic acid 7alpha
dehydroxylation in the intestines. The levels and activities of bile acid 7alpha
dehydroxylating bacteria have been reported to be increased in gallstone
patients. The aim of the current study was to isolate 7alpha-dehydroxylating
bacteria from gallstone patients and determine if these individuals are colonized
by similar bacterial species. METHODS: The levels of 7alpha-dehydroxylating
bacteria in fecal samples were determined by fecal dilutions in 24 gallstone
patients and 10 controls. 7alpha-Dehydroxylating bacteria were isolated by a non
selective streak plate technique and 7alpha-dehydroxylation activity was
determined by measuring the conversion of [14C]-cholic acid to [14C]-deoxycholic
acid using thin-layer chromatography. RESULTS: Gallstone patients had >42-fold
(p<0.01) higher levels of 7alpha-dehydroxylating bacteria than patients who had
not developed gallstones. Eighteen strains of 7alpha-dehydroxylating bacteria
were isolated from eight gallstone patients. Attempts to isolate 7alpha
dehydroxylating bacteria from ten control patients were unsuccessful using
identical isolation techniques. Surprisingly, all strains of bacteria isolated
from gallstone patients appear to belong to the genus Clostridium. CONCLUSION:
Gallstone patients have higher levels of 7alpha-dehydroxylating fecal bacteria
and appear to harbor only members of the genus Clostridium with this activity.
PMID- 10673061
TI - Development of gap junctional channels and intercellular communication in rat
liver during ontogenesis.
AB - BACKGROUND/AIMS: We investigated the expression of connexin (Cx) 32 and 26
subunit proteins of the gap junction (GJ) in the rat liver during ontogenesis to
clarify their roles in control of growth and differentiation, and observed their
channels in association with development of gap junctional intercellular
communication (GJIC). METHODS: The expression of Cx32 and 26 in prenatal and
postnatal livers was examined by Western blot and immunofluorescence. GJ channels
were investigated not only by double immunofluorescence study but also by
immunogold electron microscopy. The spread of lucifer yellow 5 min after its
microinjection was examined in the cultured liver tissues. RESULTS: 1) Western
blot showed the expression of both Cx from the late stage of gestation and their
peak a week after birth. 2) Cx32- or 26-positive plaques were scattered on
hepatocytes of the fetal liver and some of them were colocalized; both were
increased just after birth. On day 7 after birth, Cx32-positive plaques were
present on all hepatocytes within a lobule, and Cx26-positive plaques were
distributed in the periportal area. 3) Double-immunogold electron microscopy just
after birth showed that most GJ channels were homotypic type of Cx32 or 26, and
that few were heterotypic. On day 7 after birth, most channels had the homotypic
type of type of Cx32 in the middle and pericentral areas, and there was a
heterotypic type of Cx32 and 26 in the periportal area. 4) The dye transfer of
lucifer yellow showed a wider spread in the liver tissues on day 7 after birth
than on day 1. CONCLUSION: Increased GJ formation and compatibility or
incompatibility of GJ channels are closely associated with development of GJIC,
and GJIC may develop at cytodifferentiation during ontogenesis.
PMID- 10673062
TI - Predictors of morbidity and mortality after the first episode of upper
gastrointestinal bleeding in liver cirrhosis.
AB - BACKGROUND/AIMS: Upper gastrointestinal (GI) bleeding is one of the most frequent
causes of morbidity and mortality in the course of liver cirrhosis. The aim of
this study was to determine the independent predictors of morbidity, mortality,
and survival after the first episode of GI bleeding in patients with liver
cirrhosis. METHODS: In a retrospective study of 403 cirrhotic patients who were
admitted in the period January 1982 to December 1994 because of a first episode
of GI hemorrhage, epidemiological factors, bleeding-related variables and
cirrhosis-related variables that may be associated with hepatic and extrahepatic
complications, mortality at 48 h and 6 weeks, and survival up to 30 June 1996
were assessed. RESULTS: Forty-five percent of patients developed hepatic and/or
extrahepatic complications, with a mortality rate of 7.4% at 48 h and 24% at 6
weeks. Renal failure, rebleeding, hepatocellular carcinoma, and hepatic
encephalopathy were independent predictors of mortality. The Kaplan-Meier method
showed a median survival of 30.9+/-4.5 months (95% confidence interval 22 to 39.7
months). The cumulative percentage of survivors was 60.2% at 1 year, 33.6% at 5
years, and 14% at 10 years. In a Cox's multiple regression analysis, age, hepatic
encephalopathy, hepatocellular carcinoma, Child-Pugh grade, and renal failure
were independently associated with long-term survival. CONCLUSIONS: The first
episode of GI bleeding in patients with liver cirrhosis is associated with high
morbidity and mortality. Renal failure, rebleeding, hepatocellular carcinoma, and
hepatic encephalopathy were independent risk factors for early death.
PMID- 10673063
TI - Enhanced monocyte activation and hepatotoxicity in response to endotoxin in
portal hypertension.
AB - BACKGROUND/AIMS: Septic shock is a systemic response to infection, and it causes
a high mortality rate in cirrhotic patients. The mechanisms responsible for this
susceptibility in cirrhosis are poorly understood. The aim of this study was to
investigate whether monocyte activation and hepatic function are altered in
portal hypertension after endotoxin administration. METHODS: Portal-hypertensive
and sham-operated rats were used. Plasma levels of tumor necrosis factor-alpha
after lipopolysaccharide stimulation (both in vivo and in vitro) were measured by
ELISA. CD11b/CD18 integrin expression on leukocyte membrane was measured by flow
cytometry. Plasma transaminase activities were also determined. RESULTS: The
levels of tumor necrosis factor-alpha in plasma and the expression of CD11b/CD18
on leukocytes in portal-hypertensive rats was similar to that in sham-operated
rats. Injection of 150 microg/kg of lipopolysaccharide produced a 9-fold increase
in plasma levels of tumor necrosis factor-alpha in portal-hypertensive compared
with sham-operated rats, together with a significant up-regulation of CD11b/CD18
expression on monocytes and an elevation in plasma transaminase activity. Blood
leukocytes incubated in vitro with lipopolysaccharide (0.5 microg/ml) induced a
hypersecretion of tumor necrosis factor-alpha in portal-hypertensive rats, as
compared to sham-operated rats. CONCLUSIONS: This study shows that monocytes from
portal-hypertensive rats have an enhanced response to endotoxin, leading to
hepatotoxicity.
PMID- 10673064
TI - Pressor and renal effects of cross-linked hemoglobin in anesthetized cirrhotic
rats.
AB - BACKGROUND/AIMS: Cross-linked hemoglobin (XL-Hb), a hemoglobin-based oxygen
carrier, is currently under investigation as a blood substitute. In the present
study we have evaluated its pressor and renal effects in a rat model of liver
cirrhosis by bile duct ligation. METHODS: Experiments were performed 3 weeks
after surgery in anesthetized rats In the first protocol, the ability of XL-Hb to
recover blood pressure after a hypotensive hemorrhage (0.5 ml/min, 10 min) was
analyzed. In the second protocol, the pressor and renal effects produced by the
administration of XL-Hb were evaluated during a period of 3 h. RESULTS: After a
hypotensive hemorrhage (0.5 ml/min, 10 min), resuscitation with XL-Hb resulted in
greater and faster recovery of blood pressure than with the administration of
blood. In non-hemorrhaged rats, administration of XL-Hb (5% of blood volume)
reversibly increased blood pressure in bile duct ligation and in control rats,
but this effect was of longer duration in the control animals. XL-Hb also induced
brisk increases in water and sodium excretion in both groups of animals, but the
response of the control animals was more intense and sustained than that of the
bile duct ligation rats. Glomerular filtration rate and renal blood flow showed
slight decreases, but they were well maintained around the baseline levels. All
the parameters studied were normalized 3 h later. In additional experiments, the
effect of a bolus of L-NAME (10 mg/kg), an inhibitor of nitric oxide synthase, 1
h after the administration of XL-Hb was partially reduced, suggesting that the
effect of XL-Hb may be secondary to the disappearance of circulating nitric
oxide. CONCLUSIONS: XL-Hb seems to be effective as a resuscitative solution in
case of hemorrhage in cirrhotic rats Moreover, this blood substitute only
moderately and reversibly elevates blood pressure and does not adversely affects
renal function.
PMID- 10673065
TI - Aquaretic effects of niravoline, a kappa-opioid agonist, in patients with
cirrhosis.
AB - BACKGROUND/AIMS: In patients with cirrhosis, decreased renal water excretion is a
common complication. Niravoline (RU51599), a kappa-opioid receptor agonist, has
been shown to induce an aquaretic response. The aim of this study was to evaluate
the aquaretic effect and tolerance of niravoline in patients with cirrhosis.
METHODS: Biochemical tests and hemodynamic values were determined before and 1,
2, 3 and 24 h after niravoline administration at doses ranging from 0.5 to 2 mg
iv in 18 patients with cirrhosis. RESULTS: Diuresis significantly increased in
the first hour from 64+/-9 to 146+/-31 ml/h, and returned to basal values after 3
h. Free water clearance also significantly increased, reaching the positive range
at 1 h. Plasma osmolality significantly decreased at 2 h (from 290+/-4 to 286+/-4
mOsm/kg). Plasma sodium concentrations increased significantly at 3 h (from 133+/
1 to 134+/-1 mEq/l). Heart rate and arterial pressure did not change. The highest
doses (1.5 mg or 2 mg) induced personality disorders and mild confusion within 2
h. These effects reversed completely within 8 h. CONCLUSION: This study shows
that niravoline administration induces an aquaretic response and is well
tolerated, at moderate doses, in patients with cirrhosis. Thus, moderate doses of
niravoline may be useful for treating patients with cirrhosis and water
retention.
PMID- 10673066
TI - Mixed endothelin receptor antagonist, SB209670, decreases portal pressure in
biliary cirrhotic rats in vivo by reducing portal venous system resistance.
AB - BACKGROUND/AIMS: This study aimed to evaluate the hemodynamic effects of
endothelin-1 or mixed endothelin receptor antagonist, SB209670 in cirrhotic rats,
and to elucidate the role of endothelin in cirrhotic portal hypertension.
METHODS: Secondary biliary cirrhosis was induced by bile duct ligation.
Hemodynamics were studied using the radioactive microsphere technique. RESULTS:
Plasma and hepatic endothelin levels in cirrhotic rats were significantly higher
than those in normal rats (plasma, 9.0+/-1.3 vs. 2.6+/-0.5 pg/ml, p<0.001; liver,
74.8+/-13.3 vs. 12.6+/-2.5 pg/g wet tissue, p<0.001). Intraportal administration
of endothelin-1 (3 nmol/kg) progressively raised portal pressure without an
initial transient reduction, which was observed in systemic arterial pressure, in
both cirrhotic and normal rats. SB209670 (5.4 micromol/kg) reduced portal
pressure in cirrhotic rats (-19+/-5%, p<0.01) without modifying systemic arterial
pressure and renal blood flow, but not in normal rats. This reduction was
associated with reduced portal venous system resistance (vehicle, 2.5+/-0.2 vs.
SB209670, 1.7+/-0.1 mmHg x min x 100 g bw/ml, p<0.01), but not with change in
portal venous inflow and collateral blood flow. CONCLUSIONS: Mixed endothelin
antagonist, SB209670, decreased portal pressure by reducing portal venous system
resistance without modifying systemic arterial pressure and renal blood flow in
cirrhotic rats. This result, together with the findings that plasma and hepatic
endothelin levels were elevated in cirrhotic rats and that exogenous endothelin-1
increased portal pressure, provides further support for a role of endothelin in
portal hypertension and suggests a potential use of mixed endothelin antagonist
in the pharmacological treatment of portal hypertension.
PMID- 10673067
TI - Gene expression of TNF-receptors in peripheral blood mononuclear cells of
patients with alcoholic cirrhosis.
AB - BACKGROUND/AIMS: Elevated concentrations of tumor necrosis factor receptors have
been detected in alcoholic cirrhosis, but it remains unknown whether or not
peripheral blood mononuclear cells are a source of tumor necrosis factor
receptors and reflect the clinical disease activity of patients with advanced
alcoholic liver disease. METHODS: Twenty-two abstinent patients in different
stages of alcohol-induced cirrhosis according to the criteria of the Child-Pugh
classification (Child-Pugh stage A: 4, Child-Pugh stage B: 10, Child-Pugh stage
C: 8) were compared with four healthy individuals. Semi-quantitative reverse
transcriptase-polymerase chain reaction was used for the measurement of the
expression of tumor necrosis factor-alpha, soluble tumor necrosis factor
receptors-p55, -p75, interleukin-10 and inducible nitric oxide synthase in
unstimulated peripheral blood mononuclear cells. RESULTS: Unstimulated peripheral
blood mononuclear cells of patients with alcoholic cirrhosis demonstrate a stage
dependent enhanced RNA expression of tumor necrosis factor-alpha (healthy
controls 0/4, Child-Pugh stage A 2/4, stage B 10/10, stage C 8/8; p<0.01). The
mRNA expression of TNF-receptors-p55/-p75 is significantly higher in patients
with severe alcoholic cirrhosis (Child-Pugh stage B or C patients) than healthy
controls (p<0.05), while peripheral blood mononuclear cells from patients with
Child-Pugh stage A show a similiar pattern of gene expression to healthy
controls. No significant up-regulation of interleukin-10 was found. Inducible
nitric oxide synthase was detectable in Child-Pugh stage C (p<0.05). CONCLUSIONS:
Unstimulated peripheral blood mononuclear cells of patients with severe alcoholic
cirrhosis (Child-Pugh stage B and C) demonstrate a systemic leukocyte activation
and gene expression of tumor necrosis factor-alpha and tumor necrosis factor
receptors-p55/-p75, which is correlated with the activity of the disease. Our
data confirm previous studies that reported a correlation between plasma levels
of pro-inflammatory cytokines and the severity of alcoholic cirrhosis. The role
of interleukin-10 and inducible nitric oxide synthase in the pathogenesis of
alcoholic cirrhosis remains to be fully elucidated.
PMID- 10673068
TI - Protection by glycine against hypoxic injury of rat hepatocytes: inhibition of
ion fluxes through nonspecific leaks.
AB - BACKGROUND/AIMS: Glycine has long been shown to exert strong protective effects
against hypoxic injury of hepatocytes. Recently, it was suggested that glycine
exerts this protection via inhibition of ligand-gated chloride channels, thereby
secondarily inhibiting sodium influx. The purpose of this study was to examine
this suggestion. METHODS: Cultured rat hepatocytes were incubated under normoxic
and hypoxic conditions. Loss of viability was determined by release of lactate
dehydrogenase. Cytosolic ion concentrations were measured using digital
fluorescence microscopy. RESULTS: Glycine prevented the hypoxic increase in
cytosolic sodium and strongly protected against hypoxic injury. The amino acid
was not only protective in Krebs-Henseleit buffer but also in a chloride-free
modification thereof and offered additional protection in a sodium-free medium
(which already yielded substantial protection in its own right). Glycine also
prevented the hypoxic release of the anionic fluorescent dye Newport Green and
appeared to prevent the hypoxic entrance of the "nonphysiological" cations cobalt
and nickel. CONCLUSION: The results strongly argue against inhibition of ligand
gated chloride channels as being responsible for the potent protective effect of
glycine against hypoxic injury of hepatocytes. Instead, they suggest that glycine
prevents the formation of nonspecific leaks for small ions including sodium,
thereby providing protection.
PMID- 10673069
TI - Lovastatin decreases mortality and improves liver functions in fulminant hepatic
failure from 90% partial hepatectomy in rats.
AB - BACKGROUND/AIMS: Liver insufficiency occurs when the liver cannot perform
critical functions such as ammonia metabolism, gluconeogenesis, or production of
coagulation factors The hypothesis of this study was that decreased function of
existing hepatocytes may contribute to hepatic failure, and that the function of
these cells might be increased pharmacologically. Lovastatin is a 3-hydroxy-3
methylglutaryl CoA reductase inhibitor that inhibits cholesterol biosynthesis and
affects the activity of some signal transduction pathways and liver transcription
factors. Changes in hepatic transcription factors during liver regeneration might
result in decreased liver functions, and lovastatin might prevent these changes
METHODS: Rats received 90% partial hepatectomy (90% PH), and either lovastatin or
vehicle alone daily. Survival and liver functions were assessed. RESULTS:
Lovastatin increased survival to 58% (vs. 6% in controls that received 90% PH
without drug), decreased the peak ammonia level to 427 microM (vs. 846 microM in
controls), increased the nadir of glucose to 88 mg/dl (vs. 57 mg/dl in controls),
decreased the peak prothrombin time to 23 s (vs 29 s in controls), and decreased
the peak activated partial thromboplastin time to 29 s (vs. 39 s in controls).
The full survival and metabolic benefits were observed when lovastatin was
started at 30 min after 90% PH, but lovastatin was less efficacious when started
at later times. CONCLUSIONS: Lovastatin increases the function of existing
hepatocytes and might be used to improve liver function after extensive hepatic
resection.
PMID- 10673070
TI - Protein expression of CD44 (standard and variant isoforms) in hepatocellular
carcinoma: relationships with tumor grade, clinicopathologic parameters, p53
expression, and patient survival.
AB - BACKGROUND/AIMS: Members of the CD44 family are transmembrane glycoproteins which
act mainly as receptors for hyaluronan. We have examined the expression of CD44s
and several CD44v and the relationship between these and hepatocellular carcinoma
(HCC) grade, clinicopathological parameters, p53 expression, and patient survival
in HCC. METHODS: Formalin-fixed, paraffin-embedded tissue sections from 107
surgically resected HCC were examined immunohistochemically using a semi
quantitative scoring system to detect the expression of different forms of CD44.
RESULTS: The number of CD44s-positive cases was 36 (34%), CD44v5 52 (49%), CD44v6
29 (27%), CD44v7-8 41 (38%), and CD44v10 26 (24%). Expression of these molecules
correlated with high histological grade, being the highest in poorly
differentiated HCC. High CD44v6 expression significantly correlated with the
presence of vascular invasion and p53 overexpression. Kaplan-Meier examination of
patient survival revealed that HCC patients with positivity of each of these five
molecules had a reduced survival rate, and that HCC patients positive for all the
five CD44 molecules had worse survival than HCC patients positive for four or
less of these CD44 molecules. In multivariate survival analysis, CD44s positivity
was an independent factor. However, positivity for one or more CD44 isoforms was
the most useful independent factor for overall survival. CONCLUSION: These
results suggest that up-regulation of CD44 isoforms is associated with poorly
differentiated HCC and shortened survival.
PMID- 10673071
TI - Increased GABAergic activity inhibits alpha-fetoprotein mRNA expression and the
proliferative activity of the HepG2 human hepatocellular carcinoma cell line.
AB - BACKGROUND/AIMS: Gamma aminobutyric acid (GABA) is a potent inhibitory
neurotransmitter with growth regulatory properties. Recent data indicate that
increased GABAergic activity inhibits hepatocyte proliferation in regenerating
livers. In the present study, we aimed to investigate whether GABA inhibits the
growth of malignant hepatocytes. METHODS: Increasing concentrations of muscimol
(0.05-50 microM), a specific GABA(A) receptor agonist, were added to HepG2 human
hepatocellular carcinoma cells and alpha-fetoprotein (AFP) and albumin mRNA
expression were determined for varying periods of time (maximum 24 h) thereafter.
Cell proliferation was also documented after 48 h of exposure to muscimol.
RESULTS: Muscimol significantly (p<0.0001) decreased AFP mRNA expression (maximum
decrease: 65% below baseline values) without affecting albumin mRNA expression.
However, the effect on AFP mRNA was transient (maximum duration: 3-6 h) and not
associated with changes in cell proliferation. Because preliminary data indicate
that GABA(A) receptor activity is markedly downregulated in malignant
hepatocytes, transfection studies were performed wherein HepG2 cells were
cotransfected with GABA(A) receptor beta2 and beta2 subunit genes in a pCDM8
expression vector or vector alone followed by re-exposure to either muscimol (5
betaM) or saline. In this series of experiments, in addition to AFP mRNA
inhibition being as extensive and more prolonged (maximum duration: 6-12 h) in
muscimol-treated, GABA(A) receptor-transfected cells, proliferative activity was
also significantly inhibited when compared to saline-treated GABA(A) receptor
transfected controls (p<0.01) and muscimol-treated cells transfected with vector
alone (p<0.005). CONCLUSION: The results of this study indicate that increased
GABAergic activity inhibits AFP mRNA expression and cell proliferation in this
malignant hepatocyte cell line.
PMID- 10673072
TI - A possible novel src-related tyrosine kinase in cancer cells of LEC rats that
develop hepatocellular carcinoma.
AB - BACKGROUNDS/AIMS: Src-related protein tyrosine kinase is known to be related to
cell transformation. In this study, we report a possible novel src-related
tyrosine kinase of 100 kDa specifically expressed in the nuclei of hepatocytes
and/or cancer cells in Long-Evans Cinnamon rats, one of the experimental models
of hepatocellular carcinoma. METHODS: Src-related protein tyrosine kinase in
hepatocytes of Long-Evans Cinnamon rats was analyzed by using
immunohistochemistry and Western blot and in vitro tyrosine kinase assay using a
specific antibody (src antibody) against a synthetic peptide corresponding to the
conserved autophosphorylation site of src family tyrosine kinases. RESULTS: Src
related protein was found to be expressed in the nuclei of hepatocytes and/or
cancer cells in Long-Evans Cinnamon rat liver, exhibiting tyrosine kinase
activity, and migrated to the position of 100 kDa. The protein quantity and
activity of this 100-kDa src-related protein tyrosine kinase significantly
increased with the progress of chronic hepatitis to hepatocellular carcinoma,
especially in the tumorous portion of the liver. On the other hand, the 100-kDa
src-protein tyrosine kinase was not observed in the nuclei of hepatocytes and/or
cancer cells in normal age-matched control Wistar rats. CONCLUSIONS: Since the
src-family tyrosine kinases have been observed at a molecular weight of 55 to 62
kDa and located in the hepatocellular membrane and/or cytoplasm, the 100-kDa src
related protein tyrosine kinase observed in the present study may be novel, and
closely related to the pre-cancerous and cancerous process in Long-Evans Cinnamon
rat liver.
PMID- 10673073
TI - Characteristics of Epstein-Barr virus primary infection in pediatric liver
transplant recipients.
AB - BACKGROUND/AIM: Pediatric liver transplant recipients are at high risk of Epstein
Barr virus infection. However the incidence of clinical symptoms and the graft
function at the time of acute infection remains poorly documented. The aim of
this study was to monitor the clinical and biochemical events associated with
primary Epstein-Barr virus infection. METHODS: Clinical and biological patterns
associated with Epstein-Barr virus infection were prospectively searched in 38
liver transplanted children. Polymerase chain reaction and anti-Epstein-Barr
virus IgM antibodies were used at regular intervals to detect the timing of
primary infection. RESULTS: Five children (13%) had pretransplant immunity, 26
(68.5%) developed primary Epstein-Barr virus infection 15 to 90 days after
transplantation and seven (18.5%) remained Epstein-Barr virus negative. The four
patients with clinical symptoms at the time of infection subsequently developed
post-transplant lymphoproliferative disease. A single post-transplant
lymphoproliferative disease occurred in non-symptomatic patients (overall
incidence 13%). No mortality was associated with post-transplant
lymphoproliferative disease. Two asymptomatic patients had abnormal liver
function tests possibly related to primary Epstein-Barr virus infection.
CONCLUSION: Epstein-Barr virus primary infection occurs in 80% of seronegative
patients within 3 months after OLT. Clinical symptoms are rare and closely
associated with post-transplant lymphoproliferative disease. Outside post
transplant lymphoproliferative disease, the consequences of infection are
marginal.
PMID- 10673074
TI - Cold preservation of fatty liver grafts: prevention of functional and
ultrastructural impairments by venous oxygen persufflation.
AB - BACKGROUND/AIMS: The incidence of steatosis in livers retrieved for organ
transplantation is up to 30%. Due to the shortage of donor organs, many of these
livers are accepted for clinical transplantation, although a high rate of graft
dysfunction is associated with ischemic preservation of steatotic livers. The
present study was intended to reduce the ischemia/reperfusion injury of steatotic
grafts by the use of venous systemic oxygen persufflation during cold storage.
METHODS: A histologically-documented mild to moderate steatosis was induced in
livers of Wistar rats by fasting for 2 days and subsequent feeding of a fat-free
diet enriched in carbohydrates. Fatty livers were retrieved and flushed via the
portal vein with 60 ml of HTK. In group A, livers were then stored ischemically
at 4 degrees C for 24 h. Livers of group B were additionally connected to a
gaseous oxygen supply and persufflated with O2 via the venous vascular system
during the cold storage period. Viability of the livers was then assessed upon
isolated perfusion in vitro with oxygenated Krebs-Henseleit buffer. RESULTS:
Venous systemic oxygen sufflation resulted in a relevant and significant
reduction of parenchymal (ALT: 132+/-90 vs 434+/-172 U/l; p<0.01) and
mitochondrial (GLDH: 116+/-57 vs 633+/-241 U/l; p<0.001) enzyme release during
reperfusion. Moreover, Kupffer cell activation, as evaluated from acid
phosphatase activity in the perfusate, was reduced to about 1/3 (4.0+/-1.3 vs
11.9+/-5.3 U/l; p<0.01). Electron microscopic analysis revealed that the liver
mitochondria and sinusoidal endothelial lining were better preserved after oxygen
persufflation, which was in line with the data on enzyme release and the
increased portal perfusion pressure in the untreated group, while normal values
were found after venous systemic oxygen sufflation. CONCLUSION: Venous oxygen
persufflation may thus represent a useful tool for the safe and improved
preservation of ischemia-sensitive steatotic livers.
PMID- 10673075
TI - Endotoxin-induced aggravation of preservation-reperfusion injury of rat liver and
its modulation.
AB - BACKGROUND/AIMS: In clinical transplantation, exposure of donors to gut-derived
endotoxin occurs frequently and may adversely affect liver transplantation
therapy. The aim of this study was to investigate: 1) whether brief exposure of
rats to endotoxin before liver procurement aggravates the early phase of
reperfusion injury of hepatic explants; and if so 2) whether Kupffer cell
activation is a contributing factor to liver injury; and 3) whether heparin and
pentoxifylline could minimize this effect. METHODS: Male Wistar rats were
injected with 0.2-4.0 mg/kg of Escherichia coli lipopolysaccharide 2 h prior to
liver harvest. After preservation in University of Wisconsin cold-storage
solution, the livers were reperfused using a blood-free perfusion model. To
inactivate Kupffer cells, some rats were pretreated with gadolinium chloride or
liposome-encapsulated dichloromethylene-diphosphonate before lipopolysaccharide
administration. The other rats received lipopolysaccharide with heparin or
pentoxifylline. RESULTS: In a dose-independent fashion, lipopolysaccharide
impaired portal flow during graft reperfusion. In a dose-dependent way,
lipopolysaccharide increased lactate dehydrogenase release into the perfusate and
decreased bile flow and bromosulfophthalein excretion. Gadolinium chloride,
liposomal dichloromethylene-diphosphonate, heparin, and pentoxifylline reduced
lactate dehydrogenase release by 34%, 43%, 59%, and 64%, respectively, and
improved functional parameters of the liver. A 52-fold increased neutrophil
infiltration in the liver sinusoids after lipopolysaccharide exposure was not
affected significantly by the drugs studied; however, heparin reduced markedly
neutrophil activation. CONCLUSIONS: The results of this investigation provide
direct evidence that aggravation of preservation-reperfusion injury of rat liver
by endotoxin is mediated by Kupffer cell-dependent mechanism(s) and it can be
minimized by heparin and pentoxifylline.
PMID- 10673076
TI - Expansion of peripheral blood CD5+ B cells is associated with mild disease in
chronic hepatitis C virus infection.
AB - BACKGROUND/AIMS: Hepatitis C virus (HCV) infection is associated with the
development of chronic liver disease and extra-hepatic manifestations, which
include autoantibody production, immune-mediated diseases such as
cryoglobulinaemia and B-cell lymphoproliferation. Recent identification of intra
hepatic clonal B cells capable of rheumatoid factor production, selective
infection of B cells over T cells and of an HCV receptor on B lymphocytes
strongly supports a central role for these cells in the immune response to HCV
infection. In particular, CD5+ B cells which are capable of producing natural
antibodies with autoreactive specificities are likely to be important in the
development of HCV-associated autoimmunity and lymphoproliferation. METHODS: We
have investigated the presence of CD5+ B cells in a unique cohort of HCV-infected
women who were infected with a single inoculum of HCV genotype 1b following
immunisation with contaminated anti-D immunoglobulin in 1977. RESULTS: CD5+ B
cells are significantly increased in chronic HCV infection (37.66+/-1.92%) as
compared with those with resolved infection (25.33+/-1.90%). High levels of CD5+
B cells were associated with the production of rheumatoid factor. The number of
peripheral blood CD5+ B cells correlated negatively with histological activity
index. CONCLUSIONS: The expansion of this B cell population in patients with
active HCV infection may give rise to immune-mediated sequelae associated with
HCV infection. This expanded population of CD5+ B cells may protect against the
development of progressive liver disease.
PMID- 10673077
TI - Post-transplant quasispecies pattern remains stable over time in patients with
recurrent cholestatic hepatitis due to hepatitis C virus.
AB - BACKGROUND/AIMS: Several studies have shown that cholestatic recurrent hepatitis
is associated with very high HCV RNA loads in liver transplant recipients. The
aim of this study was to investigate whether a correlation exists between
cholestatic hepatitis post-transplant and the population of viral quasispecies.
METHODS: One hundred and nine serial sera samples were tested from 15 recurrent
HCV patients. Four of these patients showed severe cholestatic recurrent
hepatitis, 11 patients demonstrated non-cholestatic recurrent hepatitis post
transplant. Quasispecies were detected by RT-PCR amplification of the HVR1
followed by single-stranded conformational polymorphism analysis. RESULTS: Forty
one samples from four cholestatic patients were tested. All four patients showed
very stable quasispecies patterns post-transplant. One cholestatic patient also
showed a stable quasispecies band pattern following retransplantation, again
associated with severe cholestatic hepatitis. Sixty-eight samples were tested
from the 11 non-cholestatic patients. In contrast, these patients showed
significantly more quasispecies bands than the cholestatic patients. The
noncholestatic patients also displayed fluctuating band patterns post-transplant.
Serial samples were tested after retransplantation in one non-cholestatic
patient, with a fluctuating pattern again seen. There was a negative correlation
between the HCV RNA load in serum and the number of quasispecies bands.
CONCLUSIONS: Stable hepatitis C viral quasispecies associated with persistently
high viral load in post-transplant cholestatic hepatitis suggest that viral
escape from immune pressures may play a role in the pathogenesis of this
condition.
PMID- 10673079
TI - Diagnosis, treatment and prophylaxis of spontaneous bacterial peritonitis: a
consensus document. International Ascites Club.
PMID- 10673078
TI - Mitochondrial membrane perturbations in cholestasis.
PMID- 10673080
TI - Demonstration of McCune-Albright mutations in the liver of children with high
gammaGT progressive cholestasis.
AB - Two patients presented with neonatal cholestasis and acholic stools as first
manifestations of McCune-Albright syndrome. Both went through an extensive
evaluation including an exploratory laparotomy with peroperative cholangiography
which ruled out biliary atresia. One patient presented from the fourth month of
life with the classical cafe-au-lait spots following Blaschko's lines, while less
classical cafe-au-lait spots were seen in the second patient at the age of 4
years. Bone lesions were seen in one patient at the age of 2.5 years and in the
other at the age of 4 years. Despite the severity of presentation, both patients
cleared their jaundice within 6 months, but still had mild abnormalities of liver
function tests. Both patients showed an activating mutation of codon 201 in the
gene encoding the alpha-subunit of the G-protein that stimulates adenylcyclase in
liver tissue, suggesting that this metabolic defect could be responsible for the
cholestatic syndrome. Similar mutations have been found in other affected tissues
in patients with the McCune-Albright syndrome. We propose that McCune-Albright
syndrome be included in the list for differential diagnosis of neonatal
cholestasis and chronic cholestasis of infancy, as a rare cause.
PMID- 10673082
TI - Pericardial disease is often not recognised as a cause of chronic severe ascites.
AB - BACKGROUND/AIMS: Severe chronic ascites remains a difficult diagnostic and
therapeutic problem. Even in the current era, constrictive pericarditis is an
underestimated and sometimes unrecognised cause. Moreover, missing the diagnosis
deprives patients of remedial therapy. METHODS: Two cases of calcified
constrictive pericarditis, complicated with cirrhosis and diagnosed in a late
stage, are described. Due to insufficient clinical appreciation and lack of trust
in echocardiography results, performed by cardiologists who were insufficiently
familiar with the echocardiographic features of constrictive pericarditis,
diagnosis was delayed in the two patients RESULTS: The diagnosis of constrictive
pericarditis as a cause of ascites is based upon the clinical signs of right
heart failure in a patient with normal systolic left and right ventricular
function and a high, serumascitic albumin-content difference. Complementary
workup with complete Doppler echocardiography study, right and left heart
catheterisation and MRI or cine CT of the heart is necessary to confirm the
diagnosis. CONCLUSION: Careful history taking and clinical examination remain the
cornerstone of any diagnostic work-up, even in this era of technological
refinement.
PMID- 10673081
TI - Familial idiopathic adulthood ductopenia: a report of five cases in three
generations.
AB - BACKGROUND/AIMS: Idiopathic adulthood ductopenia is a cholestatic liver disease
of unknown etiology. Although most cases are sporadic, familial cases do occur.
METHODS: We describe a series of adult-onset bile duct depletion involving five
members of an extended family spanning three generations. The proband, a 49-year
old man, presented in 1989 with asymptomatic elevation of liver enzyme tests.
Investigations for chronic liver disease, including endoscopic retrograde
cholangiopancreatography, were negative. Findings on liver biopsy progressed from
normal in 1989 to striking loss of interlobular bile ducts in 1992.
Ursodeoxycholic acid has resulted in improvement of liver enzyme tests. The
proband's brother required a liver transplant at age 35 for cryptogenic
cirrhosis. The proband's sister, age 42, has had intermittent jaundice and
elevation of liver enzyme tests since 1971. Her liver biopsy findings progressed
from normal in 1975, to striking bile duct damage by 1997. The proband's 21-year
old son has elevated liver enzyme tests and a liver biopsy consistent with
idiopathic adulthood ductopenia. The proband's father had a liver biopsy at age
70 for investigation of a liver mass. It revealed extensive fibrosis and striking
bile duct destruction. RESULTS/CONCLUSIONS: This is the largest series of
familial idiopathic adulthood ductopenia reported, and the first with multiple
generations described. Genetics appears to play a role in some cases of adulthood
ductopenia. Ursodeoxycholic acid may be beneficial in the treatment of this
condition.
PMID- 10673083
TI - Liver failure due to herpes simplex virus.
PMID- 10673084
TI - Two different doses and duration schedules of somatostatin -14 in the treatment
of patients with bleeding oesophageal varices: a non-randomised controlled study.
PMID- 10673085
TI - Interferon therapy in patients with chronic hepatitis C and schistosomiasis.
PMID- 10673086
TI - Fatal hepatitis associated with nimesulide.
PMID- 10673087
TI - Solution-phase combinatorial synthesis and evaluation of piperazine-2,5-dione
derivatives.
AB - An efficient one-pot synthesis of a 61-membered combinatorial chemistry library
of piperazine-2,5-diones was accomplished. Results of combinatorial synthesis,
purification, analysis, and biological evaluation are described.
PMID- 10673088
TI - Synthesis and antibacterial activity of new carbapenems containing isoxazole
moiety.
AB - The synthesis and biological activity of a series of new 1beta-methylcarbapenems
1a-g containing 5'-isoxazolopyrrolidin-3'-ylthio derivatives as C-2 side chain
are described. Most compounds exhibited potent and well-balanced antibacterial
activity as well as high stability to DHP-I comparable to that of meropenem. 1e
and 1c showed the best combination of antibacterial activity and stability to DHP
I, respectively.
PMID- 10673089
TI - Synthesis and biological activities of hapalosin derivatives with modification at
the C12 position.
AB - Among the hapalosin derivatives synthesized, the compounds carrying methyl (5a),
methylthioethyl (5d) and phenylmethyl (5e) groups at the C12 position possess
only the cis-peptide structure, in contrast to the cases of 5b and 5c. In
addition to their conformational stability, the biological activities of the
compounds were determined in relation of the P-glycoprotein-mediated MDR
reversing activity and induction of apoptosis.
PMID- 10673090
TI - Epicubenol synthase. Origin of the oxygen atom of a bacterial sesquiterpene
alcohol.
AB - Incubation of epicubenol synthase with farnesyl pyrophosphate in the presence of
11.1 atom% H2(18)O gave epicubenol (2) in which the hydroxyl oxygen atom was
shown to be derived exclusively from water, as established by GC-selected ion
monitoring MS of the derived TMS-epicubenol derivative (15).
PMID- 10673091
TI - Structure-activity relationships of trans-3,5-disubstituted pyrrolidinylthio
1beta-methylcarbapenems. Part 1: J-111,347 and related compounds.
AB - 1Beta-methylcarbapenems having various 3,5-disubstituted pyrrolidinylthio-side
chains at C-2 were designed and synthesized. Evaluation of their antibacterial
activities indicated that J-111,347 (1a) is the first example of an extremely
broad spectrum antibiotic showing activity against methicillin-resistant
Staphylococcus aureus (MRSA) as well as Pseudomonas aeruginosa.
PMID- 10673092
TI - Structure-activity relationships of trans-3,5-disubstituted pyrrolidinylthio
1beta-methylcarbapenems. Part 2: J-111,225, J-114,870, J-114,871 and related
compounds.
AB - Through further derivatization of J-111,347 (1a), a trans-3,5-disubstituted
pyrrolidinylthio-1beta-methylcarbapenem, undesired epileptogenicity in a rat
intracerebroventricular assay (200 microg/rat) could be eliminated to afford J
111,225 (2a), J-114,870 (3a) and J-114,871 (3b) which preserved comparable broad
antimicrobial activity.
PMID- 10673093
TI - Structure-activity relationship study of asiatic acid derivatives against beta
amyloid (A beta)-induced neurotoxicity.
AB - 8 Semi-synthetic derivatives of asiatic acid were prepared and their protective
effect against A beta-induced neurotoxicity was evaluated. Among them, asiatic
acid (2), and 4, 16 showed 97, 92 and 87% of protective effect, respectively.
PMID- 10673094
TI - Photosensitizers related to purpurin-18-N-alkylimides: a comparative in vivo
tumoricidal ability of ester versus amide functionalities.
AB - For a comparative study, 3-(alkyloxyethyl)-3-devinylpurpurin-18-N-hexylimides
with ester and amide functionalities were investigated for tumor selectivity and
in vivo photosensitizing efficacy. Compared to amide analogues, the related
photosensitizers with ester functionalities were found to be more effective.
Among these compounds the 3-devinyl-(3-hexyloxyethyl)-purpurin-18-N-hexylimide as
methyl ester 12 showed excellent tumor uptake (tumor versus muscle ratio: 8:1),
and produced 100% tumor cure on day 30 at a dose of 1.0 micromol/kg. The mice
were treated with light (135 J/cm2, 705 nm) at 24 h post injection of the drug.
PMID- 10673095
TI - First enantiospecific synthesis of a 3,4-dihydroxy-L-glutamic acid [(3S,4S)
DHGA], a new mGluR1 agonist.
AB - The first synthesis of one of the 4 possible stereoisomers of 3,4-dihydroxy-L
glutamic acid ((3S,4S)-DHGA 3), a natural product of unknown configuration, is
described. The synthesis is based on the Lewis acid catalyzed reaction of benzyl
alcohol with a D-ribose-derived 2,3-aziridino-gamma-lactone 4-benzyl carboxylate
(6). Preliminary pharmacological studies showed that (3S,4S)-3 is an agonist of
metabotropic glutamate receptors of type 1 (mGluR1) and a weak antagonist of
mGluR4 but has no discernible activity with respect to mGluR2. This activity
profile can be rationalized by fitting extended conformations of (3S,4S)-3 in
proposed models of each of these receptor subtypes.
PMID- 10673096
TI - A new benzoangelicin with strong photobiological activity.
AB - Benzoangelicins 4-6 were synthesized in good yields from 7-hydroxy-5-methoxy-4
methylcoumarin (1). In the absence of UVA radiation, compounds 5 and 6 were only
weakly active against HL60 and HeLa tumour cells; in its presence, compound 6 was
10 times more active than the reference compound 8-methoxypsoralen. None of 4-6
exhibited cutaneous phototoxicity.
PMID- 10673097
TI - 3'-Beta-ethynyl and 2'-deoxy-3'-beta-ethynyl adenosines: first 3'-beta-branched
adenosines substrates of adenosine deaminase.
AB - The 3'-C-branched-adenosine and 2'-deoxyadenosine analogues 1-7 were tested as
substrate of adenosine deaminase. The 9-(3'-C-ethynyl-beta-D-ribo
pentofuranosyl)adenine 1 and its 2'-deoxy analogue 7 were deaminated by the
enzyme while the vinyl and ethyl derivatives 2 and 3 were not. The 9-(3'-C
branched-beta-D-xylo-pentofuranosyl)adenines 4-6 were deaminated by the
deaminase.
PMID- 10673098
TI - Multi gram synthesis of UDP-N-acetylmuramic acid.
AB - As part of an effort to discover novel antibacterial agents, a new and efficient
synthesis was established in order to provide a large amount of UDP-N
acetylmuramic acid (UDP-MurNAc).
PMID- 10673099
TI - Synthesis and estrogenic activities of novel 7-thiosubstituted estratriene
derivatives.
AB - A diastereomerically pure series of 7alpha-thioestratrienes was prepared and
evaluated for its affinity for both the human estrogen receptor alpha and the
more recently discovered estrogen receptor beta. The functional estrogenic
activities of the compounds were measured in a MCF-7 ERE-tk-luciferase assay. The
activities and selectivities of the compounds were sensitive to the nature of the
thioether side chain.
PMID- 10673100
TI - Synthesis of ketomethylene amino pseudopeptide analogues via reductive amination
of glyoxals derived from alpha-amino acids.
AB - The reductive amination of an amino acid derived glyoxal, with the free amino
group of a protected amino acid or oligopeptide fragment, has been developed as a
simple and efficient method for the preparation of ketomethylene amino pseudo
oligopeptide isosteres Aa psi(COCH2NH)Aa. Trichlorosilane-DMF is the reagent of
choice for the reduction.
PMID- 10673101
TI - The flavanolignan silybin and its hemisynthetic derivatives, a novel series of
potential modulators of P-glycoprotein.
AB - A new series of potential flavonoidic modulators of P-glycoprotein activity has
been prepared. The flavanolignan silybin was first oxidised to dehydrosilybin and
then C-alkylated with either prenyl or geranyl bromide. The resulting isoprenoid
dehydrosilybins were shown to display high in vitro affinities for direct binding
to P-glycoprotein, which ranged them among the best flavonoids ever tested.
PMID- 10673102
TI - Coumarin inhibitors of gyrase B with N-propargyloxy-carbamate as an effective
pyrrole bioisostere.
AB - The synthesis and biological profile in vitro of a series of coumarin inhibitors
of gyrase B bearing a N-propargyloxycarbamate at C-3' of noviose is presented.
Replacement of the 5-methylpyrrole-2-carboxylate of coumarin drugs with an N
propargyloxycarbamate bioisostere leads to analogues with improved antibacterial
activity. Analysis of crystal structures of coumarin antibiotics with the 24 kDa
N-terminal domain of the gyrase B protein provides a rational for the excellent
inhibitory potency of C-3' N-alkoxycarbamates.
PMID- 10673103
TI - Novel Dmt-Tic dipeptide analogues as selective delta-opioid receptor antagonists.
AB - A series of Dmt-Tic analogues with substitution on the Tic aromatic ring has been
synthesized and evaluated for opioid receptor affinity and activation.
Incorporation of large hydrophobic groups at position 7 of Tic did not greatly
alter the delta opioid receptor binding affinities of the dipeptides whereas
substitution at position 6 substantially diminished their affinity. These
modified Dmt-Tic peptides showed binding affinities as low as 2.5 nM with up to
500-fold selectivity for the delta versus mu opioid receptor and proved to be
delta receptor antagonists.
PMID- 10673104
TI - The use of power ultrasound coupled with magnetic separation for the solid phase
synthesis of compound libraries.
AB - Enhanced reaction rates are observed when power ultrasound is utilized as a
substitute for mixing during solid phase organic chemical reactions on a
paramagnetic support. Power ultrasound is also used to facilitate the washing of
the paramagnetic support as it is magnetically separated from the reaction
mixture. Selective examples from a library targeting the kappa-opioid receptor
are presented.
PMID- 10673105
TI - Synthesis and evaluation of furo[3,4-d]pyrimidinones as selective alpha1a
adrenergic receptor antagonists.
AB - Furo[3,4-d]pyrimidinones were found to be metabolites of dihydropyrimidinones
such as 1a-b that are subtype-selective antagonists of the alpha1a-adrenergic
receptor. A versatile synthesis that provides access to furo[3,4-d]pyrimidinones
in high yield and in enantiomerically pure forms is described along with
structure-activity relationships in the series.
PMID- 10673106
TI - RGD mimetics containing a central hydantoin scaffold: alpkha(v)beta3 vs
alpha(IIb)beta3 selectivity requirements.
AB - The synthesis of a series of RGD mimetic alpha(v)beta3 antagonists containing a
hydantoin scaffold is shown. The results demonstrate some of the structural
requirements for the design of selective alpha(v)beta3 antagonists (vs
alpha(IIb)beta3) in terms of the Arg-mimetic, the distance between N- and C
terminus and the lipophilic side chain.
PMID- 10673107
TI - 8-Aminocyclazocine analogues: synthesis and structure-activity relationships.
AB - Opioid binding affinities were assessed for a series of cyclazocine analogues
where the prototypic 8-OH substituent of cyclazocine was replaced by amino and
substituted-amino groups. For mu and kappa opioid receptors, secondary amine
derivatives having the (2R,6R,11R)-configuration had the highest affinity. Most
targets were efficiently synthesized from the triflate of cyclazocine or its
enantiomers using Pd-catalyzed amination procedures.
PMID- 10673108
TI - Synthesis of dolichyl phosphate derivatives with fluorescent label at the omega
end of the chain, new tools to study protein glycosylation.
AB - Derivatives of dolichyl phosphate (Dol-P) with 2-aminopyridine or 1
aminonaphtalene fluorophore groups at the omega-end of the chain were
synthesized. These products serve as substrates for recombinant yeast Dol-P
mannose synthase. Fluorescence resonance energy transfer between a Trp residue of
the enzyme and the 1-aminonaphtalene group of the Dol-P analogue was
demonstrated.
PMID- 10673109
TI - Novel 2,2-dioxide-4,4-disubstituted-1,3-H-2,1,3-benzothiadiazines as non
nucleoside reverse transcriptase inhibitors.
AB - Benzothiadiazine non-nucleoside reverse transcriptase inhibitors (NNRTIs) of HIV
have been synthesized via a novel process to afford active inhibitors, with the
most potent compound exhibiting an IC90 = 180 nM in a whole cell assay. The 2,2
dioxide-1H-2,1,3-benzothiadiazine ring system was constructed in one step from 2
amino-5-chlorobenzonitrile.
PMID- 10673110
TI - Biomechanical analysis of the stance phase during barefoot and shod running.
AB - This study investigated spatio-temporal variables, ground reaction forces and
sagittal and frontal plane kinematics during the stance phase of nine trained
subjects running barefoot and shod at three different velocities (3.5, 4.5, 5.5 m
s(-1)). Differences between conditions were detected with the general linear
method (factorial model). Barefoot running is characterized by a significantly
larger external loading rate than the shod condition. The flatter foot placement
at touchdown is prepared in free flight, implying an actively induced adaptation
strategy. In the barefoot condition, plantar pressure measurements reveal a
flatter foot placement to correlate with lower peak heel pressures. Therefore, it
is assumed that runners adopt this different touchdown geometry in barefoot
running in an attempt to limit the local pressure underneath the heel. A
significantly higher leg stiffness during the stance phase was found for the
barefoot condition. The sagittal kinematic adaptations between conditions were
found in the same way for all subjects and at the three running velocities.
However, large individual variations were observed between the runners for the
rearfoot kinematics.
PMID- 10673111
TI - Mechanical validation of whole bone composite tibia models.
AB - Composite synthetic models of the human tibia have recently become commercially
available as substitutes for cadaveric specimens. Their use is justified by the
advantages they offer as a substitute for real tibias. The present investigation
concentrated on an extensive experimental validation of the mechanical behaviour
of the whole bone composite model, compared to human specimens for different
loading conditions. The stiffness of the tibias was measured with a torsional
load applied along the long axis, and with a bending load applied both in the
latero-medial and in the antero-posterior direction. The bending stiffness of the
composite tibias matched well with that of the cadaveric specimens. This was not
true for the torsional stiffness. In fact, the composite tibias were much stiffer
than the cadaveric specimens, possibly due to the structure of the reinforcement
material. The inter-specimen variability for the composite tibias was much lower
than that for the cadaveric specimens. Thus, it seems that the composite tibias
are suitable to replace cadaveric specimens for certain types of test, whereas
they might be unsuitable for others, depending on the loading regimen.
PMID- 10673112
TI - Bone mineral density and bone structure parameters as predictors of bone
strength: an analysis using computerized microtomography and gastrectomy-induced
osteopenia in the rat.
AB - In this study the relationships of bone mineral density (BMD) and bone structure
parameters calculated from 2D microtomography images to bone strength were
investigated. Femurs from 21 male Sprague Dawley rats were subjected to dual
energy X-ray absorptiometry, computerized microtomography (CmicroT) and either
three-point cantilever bending (femoral shaft) or two-point bending compression
(femoral neck). Gastrectomy was performed on 12 animals and 9 were sham operated.
From the tomograms bone structure analysis was performed using a software routine
based on grey level run-length method. Correlations of BMD and bone structure
parameters to mechanical parameters were investigated as were differences between
the gastrectomized and the control samples. The reductions of BMD between the
groups were 21 and 27% in the femoral neck and shaft, respectively. For the
shaft, the correlations of BMD to all mechanical parameters were significant and
BMD was a consistent predictor of bone strength for cortical bone. However, in
the femoral neck where cancellous bone predominates, BMD was weakly correlated
only to deflection. A significant correlation between trabecular thickness and
neck bone strength was found. Hence, compared to trabecular thickness, BMD was of
limited value in predicting bone strength in the femoral neck.
PMID- 10673113
TI - Role of tapering in aortic wave reflection: hydraulic and mathematical model
study.
AB - Pressure and flow have been measured simultaneously at six locations along the
aorta of an anatomically correct 1:1 scale hydraulic elastic tube model of the
arterial tree. Our results suggest a discrete reflection point at the level of
the renal arteries based on (i) the quarter-wavelength formula and (ii) the
comparison of foot-to-foot (c(ff)) and apparent phase velocity (c(app)). However,
separation of the pressure wave into an incident and reflected wave at all six
locations indicates continuous reflection: a reflected wave is generated at each
location as the forward wave passes by. We did a further analysis using a
mathematical transmission line model with a simple tapering geometry (length 50
cm, 31 and 11 mm proximal and distal diameter, respectively) for a low (0.32
ml/mmHg), normal (1.6 ml mmHg) and high (8 ml/mmHg) value of total arterial
compliance. Using the quarter-wavelength formula, a discrete reflection point is
found at x = 33 cm, the level of the renal arteries, independent of the value of
total compliance. However, local analysis comparing c(ff) and c(app) does not
reveal a marked reflection site, and the analysis of incident and reflected waves
merely suggests a continuous reflection. We therefore conclude that the measured
in vivo aortic wave reflection indices are the result of at least two interacting
phenomena: a continuous wave reflection due to tapering, and local reflections
arising from branches at the level of the diaphragm. The continuous reflection is
hidden in the input impedance pattern. Using the quarter-wavelength formula or
the classical wave separation theory, it appears as a reflection coming from a
single discrete site, confusingly also located at the level of the diaphragm.
Therefore, the quarter-wavelength formula and the linear wave separation theory
should be used with caution to identify wave reflection zones in the presence of
tapering, i.e., in most mammalian arteries.
PMID- 10673114
TI - Three-dimensional finite element analysis of the human temporomandibular joint
disc.
AB - A three-dimensional finite element model of the articular disc of the human
temporomandibular joint has been developed. The geometry of the articular
cartilage and articular disc surfaces in the joint was measured using a magnetic
tracking device. First, polynomial functions were fitted through the coordinates
of these scattered measurements. Next, the polynomial description was transformed
into a triangulated description to allow application of an automatic mesher.
Finally, a finite element mesh of the articular disc was created by filling the
geometry with tetrahedral elements. The articulating surfaces of the mandible and
skull were modeled by quadrilateral patches. The finite element mesh and the
patches were combined to create a three-dimensional model in which unrestricted
sliding of the disc between the articulating surfaces was allowed. Simulation of
statical joint loading at the closed jaw position predicted that the stress and
strain distributions were located primarily in the intermediate zone of the
articular disc with the highest values in the lateral part. Furthermore, it was
predicted that considerable deformations occurred for relatively small joint
loads and that relatively large variations in the direction of joint loading had
little influence on the distribution of the deformations.
PMID- 10673115
TI - Quantifying the strain history of bone: spatial uniformity and self-similarity of
low-magnitude strains.
AB - We hypothesize that when a broad spectrum of bone strain is considered, strain
history is similar for different bones in different species. Using a data
collection protocol with a fine resolution, mid-diaphyseal strains were measured
in vivo for both weightbearing and non-weightbearing bones in three species: dog,
sheep, and turkey, with strain information collected continuously while the
animals performed their natural daily activities. The daily strain history was
quantified by both counting cyclic strain events (to quantify the distribution of
strains of different magnitudes) and by estimating the average spectral
characteristics of the strain (to quantify the frequency content of the strain
signals). Counting of the daily (12-24 h) strain events show that large strains
(> 1000 microstrain) occur relatively few times a day, while very small strains
(< 10 microstrain) occur thousands of times a day. The lower magnitude strains (<
approximately 200 microstrain) are found to be more uniform around the bone cross
section than the higher magnitude, peak strains. Strain dynamics are found to be
well described by a power-law relationship and exhibit self-similar
characteristics. These data lead to the suggestion that the organization of bone
tissue is driven by the continual barrage of activity spanning a wide but
consistent range of frequency and amplitude, and until the mechanism of bone's
mechanosensory system is fully understood, all portions of bone's strain history
should be considered to possibly play a role in bone adaptation.
PMID- 10673116
TI - How do changes to plate thickness, length, and face-connectivity affect femoral
cancellous bone's density and surface area? An investigation using regular
cellular models.
AB - Models of regular cellular-solids representing femoral head 'medial group' bone
were used to (1) compare thickness data for plate-like and beam-like structures
at realistic surface areas and densities; (2) test the validity of a standard
formula for trabecular thickness (Tb.Th); and (3) study how systematic changes in
cancellous bone thicknesses, spacing, and face-connectivity affect relative
density and surface area. Models of different face-connectivities, produced by
plate removal from the unit cell, were fitted to bone density and surface area
data. The medial group bone was anisotropic: the supero-inferior (SI) direction
was the principal direction for bone plate alignment and the plane normal to this
had the largest number of bone/void intersections per unit line length (P(I)). A
comparison of boundary perimeter per unit area data, in planes normal to SI, with
surface area data placed the medial group bone between prismatic structures in
which walls are parallel to one principal direction and isotropic structures.
Selective removal of plates from a closed-cell model produced a similar result.
For the same relative density and surface-area, plate-like models had
significantly thinner cross-sections than beam-like models. The formula for Tb.Th
produced overestimates of model plate thickness by up to 20% at realistic femoral
cancellous densities. Trends in data on surface area to volume ratio and density
observed on sampled medial group bone could be simulated by plate thickness
changes on models of intermediate face-connectivity (approximately 1.5) or by
plate removal from models with relatively thick and short (low aspect-ratio)
plates. The latter mechanism is unrealistic for it resulted in beam-like
structures at low 'medial group' densities, an architecture unlike the
predominantly plate-like bone in the sample.
PMID- 10673117
TI - The effects of damage and microcracking on the impact strength of bone.
AB - Microcracking has been shown to occur when bone is 'damaged' as shown by a loss
of stiffness. The effect on bone's toughness of the types of damage produced at
low losses of stiffness are not known. We loaded bovine bone specimens in bending
and tension to stiffness losses of up to 27%, and examined the microcracking
produced. The tensile specimens had diffuse arrays of microcracks of 2-20 microm
in length, characteristic of tensile loading, on all surfaces. The bending
specimens showed tensile microcracking on the tensile surface and characteristic
long, straight, cross-hatched compression cracks on the compressive surface.
Specimens were then broken in impact. Those that had been damaged in bending were
divided into two groups, in one group the part of the specimen which had
undergone compression damage was placed in tension, and in the other group the
tensile damage was placed in tension. Tensile damage loaded in tension did not
reduce the bone's energy-absorbing ability in impact until a modulus reduction of
over 20%. However compression damage loaded in tension did severely reduce the
bone's energy absorption capabilities (by an average of about 40%).
PMID- 10673118
TI - Modeling the stability of the human glenohumeral joint during external rotation.
AB - An analytical model of the human glenohumeral joint was developed to predict
glenohumeral kinematics and investigate how the glenohumeral capsule and
articular contact between the humeral head and the glenoid stabilize the joint.
This was performed during a simulation of an apprehension clinical exam or the
cocked phase of throwing, when the humerus is susceptible to anterior instability
or dislocation. Contact between the joint surfaces was modeled using a deformable
articular contact method and the capsule was modeled as five elements with the
ability to wrap around the surface of the humeral head. Experimental measurements
(Novotny et al., Journal of Shoulder and Elbow surgery, 1998, 7, 629-639)
provided geometric data from four in vitro specimens and kinematic results to
validate model predictions. Material properties were taken from the literature.
An equilibrium approach was used with the forces and moments produced by the
ligaments and surface contact balanced against those applied externally to the
humerus during external rotation of the abducted and extended humerus. The six
equilibrium equations were solved for the position and orientation of the
humerus. The center of the humeral head translated posteriorly and superiorly
with external rotation. Model predictions for translational and rotational ranges
of motion were not significantly different from experimental findings; however,
at individual moment increments, the model underestimated the external rotation
and overestimated the superior-inferior position of the humerus relative to the
glenoid. The anterior band of the inferior glenohumeral ligament increased in
tension with external rotation, while the axillary pouch and posterior band
decreased in tension. Contact area, stress and force increased with external
rotation and the contact area moved posteriorly and inferiorly around the rim of
the glenoid. The model results provide information on how the relationship
between the ligament element tensions and contact forces may act to avoid
glenohumeral instability.
PMID- 10673119
TI - Study on blood constitutive parameters in different blood constitutive equations.
AB - A method is proposed to study the steady blood constitutive equation (BCE). With
the method several BCEs are tested and Quemada, Bi-exponent and K-L equations are
found to be well in agreement with the hemorheological characteristics of human
and canine blood and these equations may be well used in hemorheology and
hemodynamics. In addition, the potential clinical applications of some blood
constitutive parameters (BCPs) are discussed. It is found that the hematocrit can
significantly affect the BCPs: K(A) = alpha2/alpha1, Q(A) = eta0/eta(infinity),
R(A) = etaA/eta(e) - 1, which means relative viscosities and they may be related
to RBC aggregative level. Moreover, we also show that the parameters are related
to the RBC aggregative strength and level.
PMID- 10673120
TI - A telemetry-based device to determine the force-displacement behaviour of
materials in high impact loading situations.
AB - Meaningful testing of stab resistant body armour requires the use of realistic
body tissue simulants. A device for the determination of the force-displacement
behaviour of materials in high impact loading situations has been developed for
the testing of such simulants. Force measurement is achieved with the use of
electrical foil strain gauges applied to a cylindrical load cell. A piezo
resistive accelerometer (+/- 500 g) is used to calculate the displacement of the
device through double integration of its signal, with the impact velocity used as
a boundary condition. The signals from the strain gauge circuit and the
accelerometer are sampled at 2500 Hz. The data are transmitted to a receiver via
telemetry using a 418 MHz FM transmitter and from the receiver to a laptop PC via
the serial port. Calibration of the device is described and sample results
showing forces up to 2500 N and displacements up to 0.04 m are presented.
PMID- 10673121
TI - Constitutive modelling of abdominal organs.
AB - Abdominal organs are very susceptible to trauma. In order to protect them
properly against car crash and other impact consequences, we need to be able to
simulate the abdominal organ deformation. Such simulation should account for
proper stress-strain relation as well as stress dependence on strain rate. As the
step in this direction, this paper presents three-dimensional, non-linear,
viscoelastic constitutive models for liver and kidney tissue. The models have
been constructed basing on in vivo experiments conducted in Highway Safety
Research Institute and the Medical Centre of The University of Michigan (Melvin
et al., 1973). The proposed models are valid for compressive nominal strains up
to 35% and fast (impact) strain rates between 0.2 and 22.5 s(-1). Similar models
can find applications in computer and robot assisted surgery, e.g. the realistic
simulation of surgical procedures (including virtual reality) and non-rigid
registration.
PMID- 10673122
TI - In vivo measurement-based estimations of the moment arm in the human tibialis
anterior muscle-tendon unit.
AB - The aim of this study was to estimate the moment arm of human tibialis anterior
(TA) muscle-tendon unit at rest and during isometric dorsiflexion maximum
voluntary contraction (MVC) from in vivo sagittal-plane magnetic resonance (MR)
and ultrasound scans. Two methods were employed, both of them based on the
assumption that the ankle joint complex and TA muscle-tendon unit operate in the
sagittal plane. Using method A, moment arms were obtained from MR scans of the
foot by measuring the perpendicular distance between a moving centre of rotation
in the talo-crural joint and the TA tendon action line. Using method B, moment
arms were calculated from the ratio of TA tendon displacement, which was
estimated from a planimetric muscle model using pennation angles and muscle
thickness measured by ultrasonography, to the tibial rotation around the talus,
which was measured from the foot MR scans. Using either of the two methods at
rest, the estimated TA moment arm decreased from approximately 4.5 to
approximately 2.9 cm in the transition from dorsiflexion to plantarflexion. Using
method A, moment arms during MVC were larger by 0.9-1.5 cm (33-44%, P < 0.01)
than the respective resting estimations. In contrast, no difference (P > 0.05)
was found between the resting and MVC moment arm estimations of method B.
Limitations in the oversimplified musculoskeletal model used raise questions for
the validity of both method estimations.
PMID- 10673123
TI - Characterization of load-length-velocity relationships of nine different skeletal
muscles.
AB - A three-dimensional characterization of muscle load, length and velocity was
obtained from nine muscles in the cat's hind limb through contractions where the
muscles shortened against inertial-gravitational loads. A model based on the load
length characteristic and second-order dynamics describes shortening velocity
related to load and length under these conditions. We conclude that this model
describes well contraction velocity as function of length and load under inertial
gravitational load conditions, with correlation coefficients higher than 0.9 in
most of the tested muscles.
PMID- 10673124
TI - Thresholds for step initiation induced by support-surface translation: a dynamic
center-of-mass model provides much better prediction than a static model.
AB - The need to initiate a step in order to recover balance could, in theory, be
predicted by a static model based solely on displacement of the center of mass
(COM) with respect to the base of support (BOS), or by a dynamic model based on
the interaction between COM displacement and velocity. The purpose of this study
was to determine whether the dynamic model provides better prediction than the
static model regarding the need to step in response to moving-platform
perturbation. The COM phase plane trajectories were determined for 10 healthy
young adults for trials where the supporting platform was translated at three
different acceleration levels in anterior and posterior directions. These
trajectories were compared with the thresholds for step initiation predicted by
the static and dynamic COM models. A single-link-plus-foot biomechanical model
was employed to mathematically simulate termination of the COM movement, without
stepping, using the measured platform acceleration as the input. An optimization
routine was used to determine the stability boundaries in COM state space so as
to establish the dynamic thresholds where a compensatory step must be initiated
in order to recover balance. In the static model, the threshold for step
initiation was reached if the COM was displaced beyond the BOS limits. The
dynamic model showed substantially better accuracy than the static model in
predicting the need to step in order to recover balance: 71% of all stepping
responses predicted correctly by the dynamic model versus only 11% by the static
model. These results support the proposition that the central nervous system must
react to and control dynamic effects, i.e. COM velocity, as well as COM
displacement in order to maintain stability with respect to the existing BOS
without stepping.
PMID- 10673125
TI - Comments on 'A multi-phase optimal control technique for the simulation of a
human vertical jump'.
PMID- 10673126
TI - The effectiveness and safety of brimonidine as mono-, combination, or replacement
therapy for patients with primary open-angle glaucoma or ocular hypertension: a
post hoc analysis of an open-label community trial. Glaucoma Trial Study Group.
AB - The purpose of this study was to determine the effectiveness and safety of
brimonidine 0.2% (Alphagan, Allergan Inc., Irvine, CA) as mono-, combination, or
replacement therapy for reducing intraocular pressure (IOP) in patients with
primary open-angle glaucoma or ocular hypertension. The study method was an open
label, comparative clinical evaluation involving 2335 patients. During the 2
month trial, data were collected at baseline (visit 1), month 1 (visit 2), and
month 2 (visit 3). Various parameters were evaluated, including glaucoma
medications (visit 1), IOP (visit 1-visit 3), and adverse events. A subset cohort
of 1254 patients was selected that met specific study criteria. Data from these
1254 patients were used to evaluate adverse events and the change in IOP from
visit 1 to visit 3. Patient data were grouped according to specific drug regimen,
and drug regimens were categorized into supergroups of mono-, combination, and
replacement therapy. The results of the study revealed that the overall mean
change in IOP for 1) monotherapy (n = 240) was -5.07 mm Hg (-20.2%), 2)
combination therapy (n = 554) was -4.01 mm Hg (-16.9%), 3) replacement therapy (n
= 460) was -2.33 mm Hg (-9.8%), and 4) overall (n = 1254) was -3.59 mm Hg (
14.9%) (p < 0.001 for all changes). Overall, 6.0% of the subjects reported
adverse events, with no hypersensitivity or unexpected systemic or ocular adverse
events. Eighty-five percent (85%) of clinicians rated brimonidine as "good" to
"excellent". In conclusion, brimonidine is safe and effectively lowers IOP when
used as mono-, combination, or replacement therapy as observed in a large
community population.
PMID- 10673127
TI - Aqueous humor dynamics in monkeys with laser-induced glaucoma.
AB - This study determines the effects of laser-induced glaucoma on aqueous humor
dynamics of 18 cynomolgus monkeys. Baseline measurements of 12 monkeys included
intraocular pressure (IOP) by pneumatonometry, aqueous flow by fluorophotometry
and outflow facility by tonography. Beginning 4 to 14 days later, the trabecular
meshwork of one eye was treated repeatedly with laser photocoagulation until
elevated IOP was induced. Thirty-six to 75 days after the last laser treatment,
all measurements were repeated. Between 1.7 and 11.4 years after laser treatment,
the same 12 monkeys plus 6 additional monkeys underwent IOP and aqueous flow
measurements. In addition, outflow facility was determined with fluorophotometry,
and uveoscleral outflow was both calculated (n=18) and measured with an
intracameral tracer (n=7). In glaucoma eyes compared to control eyes (n=12), IOP
was increased (p<0.04) by at least 8 mmHg at Time 1 (1 to 3 months) or Time 2 (3
to 4 years) after laser treatment; aqueous flow was reduced (p=0.0007) by 46% at
Time 1 but returned to baseline levels at Time 2; tonographic outflow facility
was reduced (p=0.0008) by 71% at Time 1. In lasered eyes compared to control
eyes, fluorophotometric outflow facility was reduced (p=0.0008; n=18) by 63%, and
uveoscleral outflow was increased (p<0.05), whether calculated or measured with
tracers at least 1 year after laser treatment. The increased IOP in monkeys with
laser-induced glaucoma was caused by a sustained reduction in outflow facility.
The uveoscleral outflow increase was not enough to prevent the rise in IOP.
PMID- 10673128
TI - Topical rivastigmine, a selective acetylcholinesterase inhibitor, lowers
intraocular pressure in rabbits.
AB - Non-selective acetylcholinesterase (AChE) inhibitors are known hypotensive
agents. The purpose of the present investigation was carried out to ascertain
whether rivastigmine, a selective carbamate-type inhibitor of AChE, which
inhibits selectively an isoform of this enzyme found almost exclusively in the
central nervous system, is able to depress the intraocular pressure (IOP) in
normotensive rabbits. IOP was monitored with a TonoPen XL in conscious adult
rabbits before and hourly up to 8 hr after administration of the drug. Baseline
measurements without treatment and after one single topical application of
rivastigmine [1% (n=8); 2% (n=4); and 5% (n=6)] to the right eye and of the
vehicle alone to the left one were performed. Rivastigmine reduced the IOP of
treated eyes significantly (p<0.05) in a dose-independent manner. Maximal effects
of 23.2% (5% rivastigmine), 19.6% (2% rivastigmine) and 15.2% (1% rivastigmine)
were achieved 1, 3 and 5 hr after application of the drug. A non-significant
reduction of IOP in the contralateral eye was also observed. Rabbits evidenced no
signs of discomfort after administration of rivastigmine. No conjunctival
discharge or other signs of drug related local toxicity were found. Rivastigmine,
a selective antagonist of AChE, lowers IOP significantly and may thus be of
potential use in glaucoma therapy.
PMID- 10673129
TI - The application of water drinking test on the evaluation of trabeculectomy
patency.
AB - The water drinking test (WDT) was once frequently used as a diagnostic tool for
glaucoma, but not so often nowadays. In this study, we investigated the potential
use of the WDT on the evaluation of trabeculectomy patency. Twenty age-matched
volunteers and thirty-six glaucoma patients who were to receive trabeculectomy
procedure were enrolled in this study. The WDT was given to the volunteers once
and to all glaucoma patients before undergoing trabeculectomy and at certain
intervals after the procedure. The WDT was performed in a standard manner. We
defined four parameters after performing the WDT: Initial Pressure [IP,
intraocular pressure (IOP) level before the WDT]; Slope of Ascending Trend (SOAT,
the slope between baseline IOP and the highest IOP level); Peak Pressure (PP, the
highest IOP level during the WDT); and End Pressure (EP, the IOP level after the
WDT). It was found that the results of the WDT and trabeculectomy patency were
strongly correlated. The four parameters in success and failure cases were
significantly different at the last follow up: IP: (15.2 +/- 3.6 vs. 25.3 +/-
6.4, p<0.01); SOAT: (0.9 +/- 0.3 vs. 1.8 +/- 1.2, p<0.01); PP: (19.2 +/- 6.4 vs.
39.5 +/- 12.2, p<0.01); EP: (15.5 +/- 4.8 vs. 29.4 +/- 8.2, p<0.01). Thus, it was
observed in this study that WDT was not only easy and safe to perform, but also
valuable in evaluating the patency of trabeculectomy.
PMID- 10673130
TI - Efficacy of latanoprost as an adjunct to medical therapy for residual angle
closure glaucoma after iridectomy.
AB - Residual primary angle-closure glaucoma (PACG) after iridectomy is an important
issue among Asians, especially Chinese. In this study, we tested the
effectiveness of latanoprost as an intraocular pressure (IOP) lowering agent in
cases of residual PACG. Twenty-six eyes of 26 PACG patients with persistently
elevated IOP after iridectomy, despite treatment with conventional IOP lowering
drugs (beta blockers and pilocarpine) were included. Latanoprost 0.005%, one drop
daily, was added adjunctively to all eyes. Measurement of IOP at baseline and
after the start of treatment with latanoprost indicated a significant IOP
reduction. The IOP decreased by about 21% (p < 0.005) during the first 3 months,
and showed a reduction of about 36% at the end of 1 year. At the 1-year follow
up, the IOP was well controlled (below 20 mmHg) in all eyes. These findings show
that, in combination with beta blockade and pilocarpine, latanoprost can
ameliorate residual PACG after iridectomy and could potentially forestall the
need for further therapeutic intervention.
PMID- 10673131
TI - Circadian variations of prostaglandins in the rabbit aqueous humor.
AB - Forty-eight young adult New Zealand albino rabbits were entrained to a daily 12
hr light and 12-hr dark cycle. Under a constant dark environment, rabbits were
sacrificed at 4-hr intervals, beginning at 2 hr before the accustomed lights-on
period. Eight rabbits were used for each of the 6 time points within 24 hr.
Aqueous humor and vitreous humor samples were collected. Samples from one eye of
each rabbit were assayed for prostaglandins D2, E2, and F2alpha by enzyme
immunoassay. Total protein concentrations in the samples were also determined.
Concentrations of prostaglandins D2 and F2alpha in the aqueous humor were found
to vary in a consistent pattern. The prostaglandin F2alpha concentration
increased in the early subjective light period, remained high in this period, and
decreased in the subjective dark period. The prostaglandin D2 concentration was
elevated only in the early subjective light period. No significant change of
aqueous humor prostaglandin E2 level was found. Total protein concentration in
the aqueous humor varied in a similar pattern as the aqueous humor prostaglandin
F2alpha, indicating a close association between the permeability of protein
across the blood-aqueous barrier and the endogenous prostaglandin F2alpha level.
In the vitreous humor, concentrations of all three prostaglandin subtypes
remained unchanged, as did the total protein concentration. However, vitreous
humor concentrations of prostaglandin D2 and F2alpha were significantly higher
than their concentrations in the aqueous humor.
PMID- 10673132
TI - Effect of nitric oxide synthesis inhibition on post-occlusive choroidal blood
flow in rats.
AB - Experiments were designed to study involvement of nitric oxide on vascular
responses to ocular ischemia in the anesthetized rat. Anterior choroidal blood
flow was measured using laser-Doppler flowmetry. In some experiments, cerebral
cortical blood flow also was measured. Ischemia was produced by either occlusion
of the cephalic blood supply or more locally via a ligature tightened around the
eye stalk. Arterial blood pressure and choroidal blood flow was continuously
measured before, during and after a 20 min ischemic challenge. Both methods of
ischemia reduced choroidal blood flow (>90%) with no consistent ocular hyperemia
seen upon reperfusion. No significant differences in response pattern between the
two ischemia techniques were apparent. Treatment with the non-selective inhibitor
of nitric oxide (L-NAME 2 mg/kg, i.v.) did not alter either basal choroidal blood
flow or the pattern of reperfusion. A larger dose of L-NAME (50 mg/kg, i.v.)
reduced both basal choroidal blood flow and the final reperfusion level (most
likely due to continued depression of the basal ocular choroidal blood flow).
Neither D-NAME nor the neuronal nitric oxide synthase inhibitor, 7-nitroindazole,
altered basal anterior choroidal blood flow or the reperfusion pattern seen after
reperfusion. The results confirm our previous observations that inhibition of
endothelial nitric oxide lowers. basal choroidal blood flow in the rat eye.
However, in contrast to the cerebral circulation where L-NAME greatly attenuates
initial reperfusion to the cerebral cortex, inhibition of nitric oxide synthase
does not appear to notably further influence anterior choroidal reperfusion.
PMID- 10673133
TI - Cell signaling in bovine ciliary epithelial organ culture.
AB - The ciliary epithelium secretes aqueous humor, an intraocular fluid whose
production is regulated in part by transmembrane signaling pathways including
those mediated by G protein-coupled receptors. Many drugs, such as beta
adrenergic receptor (AR) antagonists and alpha2-AR agonists, are used to lower
intraocular pressure by presumably decreasing fluid transport across this
epithelium. Hence, our purpose was to establish a ciliary epithelial organ
culture system suitable for the study of cell signaling pathways. A trypsin
mediated dissection method was established to isolate bovine ciliary epithelial
sheets. These sheets were cultured in a 5% CO2 incubator. The quality was
assessed by light microscopy, by protein analysis, and by the evaluation of
epinephrine-mediated phosphoinositide turnover. The cultured epithelial explants
were viable as evidenced by minimal trypan blue staining. The explants were
composed primarily of nonpigmented cells and some pigmented cells, but no other
ciliary body tissues were present on histology. Membrane preparations showed
proteins with a distribution from 31 to 116 kDa. Epinephrine caused a dose
dependent increase in [3H]inositol phosphates (InsPs) accumulation with a maximal
increase of two- to three-fold over basal levels. This epinephrine-mediated
increase was inhibited by prazosin. We established an organ culture system of
isolated bovine ciliary epithelium suitable for the study of transmembrane
signaling pathways.
PMID- 10673134
TI - Antibiotic treatment of orbital cellulitis: an analysis of pathogenic bacteria
and bacterial susceptibility.
AB - The proper choice of effective antibiotics is a mainstay for the treatment of
orbital cellulitis. The lack of native data regarding the microorganism causing
the infection and its antibiotic sensitivity prompted us to conduct this study.
We retrospectively collected 29 cases of orbital cellulitis admitted to Chung-Ho
Memorial Hospital of Kaohsiung Medical College from January 1994 to September
1998. The effectiveness of antibiotics with bacterial susceptibility was
analyzed. Of the 29 cases, fifteen were male and fourteen female. The patients
ranged in age from 7 months to 79 years (mean, 37.6 years). Sinusitis (9 cases,
31.0%) is the most common etiology. Fourteen cases received both medical and
surgical treatments. Eighteen cases had purulent discharge from the infection
areas sent for culture isolation of the microorganism. The culture positive rate
was 50% (9 in 18 cases). The Staphylococcus aureus (5 cases) was the most common
pathogen. The bacterial susceptibility test showed drug resistance of 100% for
penicillin G (seven out of seven cases; 7/7), 100% for ampicillin (10/10), and 0%
for amikacin (0/3) and vancomycin (0/7). Penicillin and ampicillin are not
effective for those isolated bacteria. Oxacillin and gentamicin, frequently used
in first line treatment, might encounter drug resistance in some cases. Amikacin
and vancomycin, without any resistance in bacterial susceptibility tests, could
be used in vision-threatening, critical, and intractable cases.
PMID- 10673135
TI - Effects of interleukin-1 blockers on corneal fibroblast proliferation in vitro
and ocular inflammation in vivo.
AB - The success of keratorefractive surgical procedures is limited by the wound
healing process in the corneal stroma. The proliferation and matrix synthesis of
corneal stromal fibroblasts is the central element of the wound healing process
that is triggered by an initial inflammation. In order to develop new therapeutic
strategies to reduce wound healing intensity, we investigated the effect of newly
synthesized interleukin-1 (IL-1) blockers on the proliferation of cultured rabbit
corneal fibroblasts and the ocular inflammation induced by IL-1. It was found
that the addition of IL-1 blockers, such as CK-135 to CK-145, led to a dose
dependent inhibition of cell proliferation after 24, 48 and 72 hr of incubation.
The isotope incorporation study showed that the syntheses ofDNA and mRNA were
suppressed whereas that of protein was enhanced or unaffected. These compounds
also demonstrated a potent anti-inflammation action in the rat uveitis model. Our
results indicate that CK (Chiou-Kumamoto) compounds may be valuable therapeutic
agents for the prevention of postoperative complications after corneal
keratorefractive surgical procedures.
PMID- 10673136
TI - Kinetic models for normal and impaired growth.
AB - Although microkinetic models are expected to play in the future the same role
that macrokinetic models have played in the past, classic mechanistic growth
functions are still worthy of study and may still provide insight into
auxological problems. The rather rigid shape of macrokinetic models may ignore
many interesting fluctuations of growth velocity, but a strong structure allows a
robust estimate of growth kinetics even in the case of growth profiles which are
largely incomplete, as those derived from current clinical records. In any case,
the too simplified shape of these models may be adjusted, to some extent, by
adding some unstructured smooth function of residuals which takes into account
minor aspects of growth (such as slight spurts during childhood), which cannot be
detected in an individual profile because of random errors and inadequate number
of observations. This paper recalls the reasons why growth models are useful,
analyses briefly the structure and the characteristics of the two fundamental
human growth functions, i.e. triple-logistic and PB1, and shows how the use of
PB1 model may be extended also to impaired growth, e.g. in girls with Turner
syndrome. In this regard, the use of the same model for normal and pathological
growth offers the important advantage that differences between growth patterns
are not confounded with differences between models.
PMID- 10673137
TI - Relationships between blood pressure, anthropometric characteristics and blood
lipids in high- and low-altitude populations from Central Asia.
AB - We studied the relationships between blood pressure, anthropometric
characteristics and blood lipids in 72 low altitude (LA) Uighurs (600 m), 91 LA
Kirghizs (900 m), 117 medium altitude (MA) Kazakhs (2100 m) and 94 high altitude
(HA) Kirghizs (3200 m). All subjects were male and had a similar age (p = ns,
ANOVA; range for all 374 subjects: 18-66 yr). Body weight (Wt), body mass index
(BM1) and the sum of four skinfolds (4SF) were significantly lower in HA-Kirghizs
than the remaining groups (p < 0.0005, p < 0.0005 and p < 0.05 respectively,
ANOVA). However, no difference was found in body fat distribution as detected by
waist:hip circumference (WHR) and triceps:subscapular skinfold ratios (TSR; p =
ns, ANOVA). Stage 1 hypertension was detected in 18% of LA-Uighurs, 2% of LA
Kirghizs, 4% of MA-Kazakhs and 1% of HA-Kirghizs; stage 2 hypertension was
detected in 2% of LA-Uighurs and none of the remaining groups; no subject had
stage 3 hypertension (The Joint National Committee on Prevention. Detection,
Evaluation and Treatment of High Blood Pressure 1997). Blood cholesterol (CH) and
triglycerides (TG) did not differ between groups (p = ns, ANOVA). The
relationships between systolic (SBP) or diastolic (DBP) blood pressure and age,
Wt, BMI, 4SF, WHR, TSR, CH and TG were independent from altitude (p = ns,
ANCOVA). In the pooled sample (n = 374), age explained 1 and 3% of SBP (p < 0.05)
and DBP (p < 0.005) variance respectively, Wt was the best predictor of SBP and
DBP explaining 11 and 10% of their variance respectively (p < 0.0001) and CH
explained 5% of DBP variance (p < 0.0001). In conclusion, hypertension is more
frequent in LA- than MA- and HA-subjects from Central Asia. However,
anthropometric characteristics and blood lipids do similarly contribute to
explain blood pressure in these subjects.
PMID- 10673138
TI - High heterogeneity of apolipoprotein E gene frequencies in South American
Indians.
AB - The apolipoprotein E (APOE) polymorphism was investigated in 186 individuals from
six South American Indian tribes, and the results integrated with those
previously presented for this ethnic group. The three APOE alleles commonly
reported in other populations were also observed in South Amerindians with a
highly heterogeneous distribution. As in other populations, APOE*3 was the most
common allele (51-98%) followed by APOE*4 (2-47%). These two isoforms were
identified in all tribes, but APOE*2 was observed among the Wai Wai (2%) and
Mataco (4%) only. No previous indications of inter-ethnic admixture were observed
among the Wai Wai, but the introduction of this allele among the Mataco through
non-Indian sources cannot be excluded.
PMID- 10673139
TI - Comparison of two methods for transforming height and weight to normality.
AB - I assessed the success of the Box-Cox power transformation and the shifted log
transformation for transforming length/height and weight to Normality.
Retrospectively collected data for full-term, healthy 1143 boys and 1162 girls
amounted to over 45000 recordings. Of the children, 48%, born during 1959-1961,
were followed from birth to age 19.0, and the rest, born during 1969-1971, until
age 12.5. The individual growth curves were smoothed in order to obtain reliable
interpolated estimates of measurements at fixed ages and to avoid age grouping.
Height is fairly Normal, even during puberty, and weight can be transformed close
to Normality, the Box-Cox transformation being preferable to the shifted log
transformation. Occasionally remaining leptokurtosis in the transformed weight
can apparently be disregarded when focusing on the extreme (1st, 2.5th, 97.5th
and 99th) centiles. The 95% confidence intervals for the two transformation
parameters are wide, and may even explode for the shift parameter. The shapes,
although not the levels, of the curves joining the estimates are similar for boys
and girls, showing a 2-year difference in maturation. Improved screening for
abnormal growth, based on the assumption of Normality, after a transformation,
seems possible.
PMID- 10673140
TI - Quantifying the 'appleness' or 'pearness' of the human body by subcutaneous
adipose tissue distribution.
AB - To quantify subcutaneous adipose tissue topography (SAT-Top) describing
individual SAT distribution for a subject or even a group we measured
subcutaneous adipose tissue thickness at 15 specified body sites of 303 healthy
women aged 20-69 yrs and 20 women with proven non-insulin-dependent diabetes
mellitus (NIDDM) by the optical device 'LIPOMETER'. The type of upper-body- and
lower-body-fat pattern, (apples or pears), was determined by factor analysis of
the data. Upper body sites were highly loaded in factor 1, whereas factor 2
included highly loaded body sites from the lower extremities. For an individual,
factor 1 scores > factor 2 scores, was described as an 'apple'-type, while factor
2 > factor 1 was described as a 'pear'-type. We found about 80% 'pears' and 20%
'apples' in 20-29 year olds and 20% 'pears' and 80% 'apples' in 60-69 year old
women. Women with NIDDM tended to be 'super-apples'. SAT-Top provides a useful
differentiation between apples and pears and we recommend this approach as a
screening method.
PMID- 10673141
TI - The importance of considering biological maturity when assessing physical fitness
measures in girls and boys aged 10 to 16 years.
AB - It is widely considered that biological maturity influences physical fitness test
performance, children can be advantaged/disadvantaged in physical fitness tests
by being more or less mature than counterparts of the same chronological age. The
current study sought to investigate the effect sexual maturity had upon
performance in physical fitness tests. A cross-sectional study involving 161
girls and 152 boys was carried out. Each subject was assessed for stature, mass,
self-assessment of sexual maturity, vertical jump, hand grip strength and the 20
m shuttle run test, all procedures were standardized. Spearman's rank correlation
coefficients were developed to assess the relationship between maturity and
physical fitness measures. ANCOVA inferential statistics were performed to
investigate if performance in physical fitness tests differed between children of
different sexual maturity stages irrespective of mass and stature. Significance
was set at p < 0.05. Stage of sexual maturity was significantly correlated with
all physical fitness measures (boys: r=0.56 to 0.73; girls: r=0.24 to 0.46).
ANCOVA revealed that when stature and mass were taken into account significant
differences were evident between sexual maturity stages in boys but not girls.
This suggests that increases in mass and stature are primarily responsible for
variation in girls' physical performance throughout maturation, whereas in boys
there are some qualitative differences in performance due to other factors. It
was concluded that sexual maturity has a large influence on physical fitness
measures in boys but less effect in girls. Rating of physical fitness,
particularly for boys should take into account biological maturity.
PMID- 10673142
TI - Growth pattern of the Sugalis--a tribal population of Andhra Pradesh, India.
AB - With a view to assess physical growth, a cross-sectional study was made on 1565
Sugali children (854 boys and 711 girls), aged 1 to 20 years. Anthropometric
measurements included height, weight, upper arm circumference, biacromial
diameter, biiliocristal diameter, chest circumference, head circumference and
skinfold measurements at triceps, subscapular, suprailiac and medial calf. All
anthropometric measurements except skinfold measurements exhibit uniform increase
with age in both the sexes. A gradual increase in four skinfold measurements is
observed with age in the case of girls, whereas slight decrease is observed in
the case of the boys. The Sugali boys and girls are shorter and lighter than well
to-do Indian standards. The median heights and weights of Sugali boys and girls
fall below the 5th percentile of NCHS standards. Finally, the results were
discussed with a comparative view point.
PMID- 10673143
TI - Phylogenetic relationships of a class of hominoid-specific retro-elements (SINE
R) on human chromosomes 7 and 17.
AB - SINE-R elements are a class of retroposon derived from the human endogenous
retrovirus HERV-K that has been active in hominoid evolution and may include some
members that are Homo sapiens specific. Both SINE-R elements and the HERV-K class
of element have potential relevance to recent genome change. Here we report on
sequences in the SINE-R class that can be detected on human chromosomes 7 and 17
and compare them with sequences that we have previously reported on the X
chromosome and in hominoid primates. The retroposons on chromosomes 7 and 17
showed a high degree of sequence homology (88-96%) with other human retroposons
(SINE-R.C2, 11, 14, 19, and HS307/HS408). Phylogenetic analysis using the
neighbour-joining method revealed that SINE-R-type retroposons on chromosomes 7
and 17 were inter-related with those of hominoid primates, suggesting that
various sub-classes of these retroposons have been evolving independently during
hominoid evolution. One element (17-11) on chromosome 17 shares one hundred per
cent identity with a 7-11 element on chromosome 7 which suggests either recent
transposition or a chromosomal translocation. Thus further investigation of the
chromosomal locations of SINE-R elements that together with the HERV-K LTR
sequence from which they are derived have the capacity to influence the function
of neighbouring cellular genes may be expected to clarify the potential role of
these elements in recent hominoid evolution.
PMID- 10673144
TI - Mitochondrial-nuclear interactions and lifespan control in fungi.
AB - In fungi, mitochondrial-nuclear interactions are part of a complex molecular
network involved in the control of aging processes. The generation of reactive
oxygen species at the mitochondrial respiratory chain plays a major role in this
network. Mitochondrial DNA instabilities, which are under the control of nuclear
genes, affect the generation of reactive oxygen species and modulate the rate of
aging. As mitochondria become dysfunctional, they transduce signals to the
nucleus and induce the expression of a set of nuclear genes, a process termed
retrograde regulation. Molecular data are emerging which suggest that retrograde
regulation is involved in lifespan control.
PMID- 10673145
TI - Biomarkers of immunosenescence within an evolutionary perspective: the challenge
of heterogeneity and the role of antigenic load.
AB - Under an evolutionary perspective, antigens can be considered nothing else than
chronic stressors that constituted the major selective pressure for immune system
emergence and evolution. In this review, recent data are discussed under the
hypothesis that human immunosenescence is the consequence of the continuous
attrition caused by chronic antigenic overload/stress. The advantage of this
theoretical approach is that a unifying hypothesis is proposed, which tries to
fill in the current gap between the conceptualizations concerning the mechanisms
which counteract aging and favor longevity in invertebrates and vertebrates. The
hypothesis is that the immune system is, at a higher level of biological
organization and complexity, the counterpart of the anti-stress response network
identified in invertebrates as the major determinant of survival. We argue that
some of the most important characteristics of immunosenescence, i.e. the
accumulation and the clonal expansion of memory and effector T cells, the
reduction/exhaustion of naive T cells, and the shrinkage of T cell repertoire,
are compatible with this assumption. Thus, immunosenescence can be envisaged as a
global reduction of the "immunological space." Concomitantly, immunosenescence
results in the progressive generation of cellular mosaicism which is the
consequence of the heterogeneous replicative histories and telomere shortening of
T and B cell subsets, as well as hemopoietic stem cells. Most of the parameters
affected by immunosenescence appear to be under genetic control, and future
research on biomarkers should address this point. On the whole, immunosenescence
can be taken as a proof that the beneficial effects of the immune system, devoted
to the neutralization of dangerous/harmful agents early in life and in adulthood,
turn to be detrimental late in life, in a period largely not foreseen by
evolution. This perspective fits with basic assumptions of evolutionary theories
of aging, such as antagonistic pleiotropy.
PMID- 10673146
TI - Hormone replacement in the aging male?.
AB - The recent increase in the elderly population, current health trends, and
awareness of age-related changes in the male endocrine system have led to
discussions about the endocrine system being a "pacemaker" of male aging. Better
prevention and treatment of "non-beneficial states of health" in aging men, such
as generally decreased well-being and virility, increased visceral fat,
osteopenia, atherosclerosis, and impaired cognitive function, is based on
improved understanding of aging, particularly the significance of age-associated
hormonal changes. Although not as dramatic as in women, men also show declining
hormone serum concentrations with aging (Vermeulen and Kaufman, 1995). Because
aging is associated with deleterious effects resembling the clinical signs of
hypogonadism or states of subnormal hormone concentrations, the potential role of
hormone supplementation in aging men paralleling hormone replacement therapy in
postmenopausal women is the topic of discussion. The goal of hormone replacement
would be to improve body composition and increase muscle strength and quality of
life in men, thereby reducing mortality and morbidity. The findings so far
support the need for long-term studies of hormonal supplementation in older males
showing decreased hormone serum levels. Nevertheless, to date, such a use outside
the context of a clinical trial is not justified.
PMID- 10673147
TI - Werner helicase expression in human fetal and adult aortas.
AB - Werner syndrome is a human progeroid syndrome caused by mutations at the Werner
helicase locus (WRN). Progeroid features and diseases associated with aging
(including arteriosclerosis) do not become apparent until after puberty. We
entertained two alternative hypotheses to explain the post-pubertal onset: 1) WRN
expression is induced at the time of puberty, its earlier functions being
satisfied by another member of that family of helicases; and 2) it is expressed
at all ages, but the phenotype of deficiency becomes apparent only after puberty.
We report initial experiments consistent with the second hypothesis. Steady-state
levels of WRN mRNA in aortic tissues were determined by semiquantitative reverse
transcription-polymerase chain reaction. WRN mRNA was detectable as early as 49
days of gestation (the earliest available material). There was no statistically
significant change in these levels between fetal and adult tissues. The presence
of the WRN protein in fetal aorta was confirmed by Western analysis. This rules
out the possibility that Werner syndrome phenotypes manifest after the puberty
because of peripubertal induction of WRN expression.
PMID- 10673148
TI - Ceroid/lipofuscin-loaded human fibroblasts show decreased survival time and
diminished autophagocytosis during amino acid starvation.
AB - To test whether heavy accumulation of ceroid/lipofuscin can disturb important
functions of the lysosomal system, AG-1518 human fibroblasts, ceroid/lipofuscin
loaded (following prolonged culture at normobaric hyperoxia) or not, were exposed
to amino acid starvation. Ceroid/lipofuscin-loading resulted in decreased
cellular survival. Also, there was an inverse relationship between amounts of
ceroid/lipofuscin and the survival time of individual cells within the same
cultures. Ceroid/lipofuscin-loaded fibroblasts displayed diminished
autophagocytotic capacity, as demonstrated by electron microscopy and by
treatment of cell cultures with NH4Cl (which inhibits autophagocytotic
degradation by increasing intralysosomal pH) for 1 week before ensuing
starvation. The latter treatment increased survival of control cells (due to
deposition of nondegraded autophagocytosed material before start of starvation),
but not that of ceroid/lipofuscin-loaded cells. Moreover, when NH4Cl treatment
was combined with starvation, both groups of cells showed approximately the same
shortened survival times, testifying to the causal relationship between
diminished autophagocytosis and decreased survival of starving ceroid/lipofuscin
loaded cells. We hypothesize that large amounts of undegradable ceroid/lipofuscin
within the acidic vacuolar compartment may interfere with lysosomal function,
resulting in poor renewal of long-lived proteins and worn-out/damaged organelles,
decreased adaptability, and cell death.
PMID- 10673149
TI - Phenotypic and functional characteristics of circulating monocytes of elderly
persons.
AB - Aging is associated with impairment of immune functions. Age-dependent
alterations in T-cells are well known. Although the pivotal role of monocytes in
immune regulation by their production of proinflammatory and inhibitory cytokines
is acknowledged, limited information is available on monocyte changes in aging.
The present study focused on phenotypic changes in circulating monocytes in
elderly subjects and in the level of cytokines they produce. The results
demonstrated a significant expansion of CD14dim/CD16bright circulating monocytes
in elderly. In contrast, the majority of circulating monocytes of healthy young
individuals were CD14bright/CD16dim. The CD14dim/CD16bright monocytes are
considered to have phenotypic evidence for activation. Furthermore, significant
increases of constitutive production of monocytic cytokines including interleukin
(IL)-1beta. IL-1 receptor antagonist, and IL-6 by nonstimulated monocytes from
elderly was also indicative of activation. This was also observed when monocytes
from elderly were cultured with autologous lymphocytes. However, after
stimulation, significantly lowered IL-1beta production was observed and IL-6 and
IL-10 tended to be higher in the elderly. Collectively, these results indicate
that monocytes of aged individuals, in contrast to a younger population exhibit
in vivo activation as well as imbalanced production of cytokines. Such age
related alterations in monocytes may contribute to impaired immune competence of
aging.
PMID- 10673150
TI - Glucocorticoid receptors in ageing rats.
AB - The role of the glucocorticoid receptor (GR) in senescence was studied in rats of
increasing age. Statistically significant changes in the number of GRs from rat
liver were detected, whereas the affinity for the ligand triamcinolone acetonide
(TA) did not change with increasing age, and was in the range of 1-2 nM. In all
cases the number of receptors was lower in rats treated with hormone in vivo
relative to untreated animals. In addition, we have found changes in GR
activation, as measured by the binding to DNA cellulose in the mentioned age
groups. Furthermore, expression of the glucocorticoid hormone (GH)-inducible
gene, tyrosine amino transferase (TAT) also showed age-related alterations. We
conclude that receptor function shows oscillatory changes during ageing. In
addition, response to GH generally declines towards the older age. This specific
periodicity in functional characteristics of the GR may reconcile conflicting
results about the receptor number and properties during the ageing process, and
marks particular age at which individual organism shows the highest or the lowest
sensitivity to the actions of GH.
PMID- 10673151
TI - 1,25-Dihydroxy-vitamin D3 (calcitriol)-dependent protein phosphorylation in rat
duodenum: effects of ageing.
AB - We have examined the ability of 1,25(OH)2-vitamin D3 [1,25(OH)2D3; calcitriol],
the hormonal form of vitamin D3, to stimulate the phosphorylation of proteins in
rat duodenum from young (3 months) and aged (22-24 months) rats. Brief (30 s)
exposure of duodenum preincubated with 32P-orthophosphate to the hormone
increased the labeling of whole tissue proteins, an effect that was greatly
diminished in aged animals. The response was dose-dependent, with maximal
stimulation achieved at 1 nM calcitriol (+113% and +10% for young and aged rats,
respectively). Phosphoproteins were resolved by sodium dodecyl sulfate
polyacrylamide gel electrophoresis and identified by autoradiography. The hormone
potentiated the phosphorylation predominantly on serine, threonine, and tyrosine
residues of five acidic proteins of relative molecular masses of 66, 48, 45, 28,
and 16 kDa. Moreover, the effects of calcitriol were exerted at the membrane
level and varied as a function of exposure time. Direct treatment of purified
basal lateral membranes for 30 s with the hormone (1 nM) stimulated the
incorporation of 32P of a 66 kDa protein by 75% and of a 48 and 45 kDa proteins
by 60%. The effects of the hormone on basal lateral membrane protein
phosphorylation were suppressed by the PKA, PKC, and tyrosine kinase inhibitors,
Rp-cAMPS, bisindolylmaleimide, and genistein, respectively. In basal lateral
membrane isolated from old animals, only minor changes in calcitriol-induced
protein phosphorylation of the 66-kDa protein were observed. Taken together,
these results suggest that calcitriol modulates duodenal membrane protein
phosphorylation, at least in part through PKA, PKC, and tyrosine kinases, and
that this mechanism is severely altered with ageing. The identity of the proteins
whose phosphorylation was stimulated by calcitriol and their physiological role
is currently under investigation.
PMID- 10673152
TI - Investigation of the endocrine system in extended longevity lines of Drosophila
melanogaster.
AB - There is a complete absence of information about the endocrinology of Drosophila
melanogaster in relation to genetic-based differential longevity in this model
species. In the present study, aspects of the endocrine system of D. melanogaster
were investigated in selected and control lines characterized by relative
differences in life span. By using extracts from whole bodies, steroid hormone
(ecdysteroid) titers were determined by radioimmunoassay in all replicate
selected and control lines on the first and fourth day of adult life. The results
suggest that ecdysteroid titers were relatively reduced on the first day post
eclosion in females from the long-lived lines, but this difference was not
present on the fourth day posteclosion. The reduction in early-age ecdysteroid
titers in long-lived females might be related to the decrease in early-age
fecundity in the selected lines. There was no difference between line types in
male ecdysteroid titers on either day post-eclosion. Two classes of enzymes that
act on juvenile hormone were also investigated in the present study. Esterase and
epoxide hydrolase activity on juvenile hormone was assessed in females in all
replicate selected and control lines at approximately 12 h or 4 days post
eclosion. There was no difference between selected and control lines in the
specific activity of either class of enzymes that metabolize juvenile hormone.
PMID- 10673153
TI - Age-dependent hypertension in Mpv17-deficient mice, a transgenic model of
glomerulosclerosis and inner ear disease.
AB - The mutant mouse strain Mpv17-/-, carries a retroviral germline integration that
inactivates the Mpv17 gene. Mpv17-deficient mice develop progressive
glomerulosclerosis and sensineural deafness at early age. Characteristic basement
membrane alterations are found in both sites of pathology. Mpv17 is a peroxisomal
protein involved in the metabolism of reactive oxygen species, yet its molecular
function is unknown. Dysregulation of antioxidant enzymes and basal membrane
components has been established in this model and successful therapeutic
intervention with antioxidants prove the causal role of reactive oxygen species
in the development of the disease phenotype. We here investigated if the Mpv17-/-
mice might be hypertensive. Indeed, our study revealed that Mpv17-/- mice
developed significant systemic hypertension and tachycardia between 4 weeks and 5
months of age, accompanied by polyuria and elevated natriuresis. Judging from
serum and urine parameters, the hypertensive condition develops concomitantly
with the renal disease. Biochemical and pharmacological studies that used the
endothelin receptor antagonist bosentan and the angiotensin converting enzyme
inhibitor cilazapril indicated no involvement of the endothelin and renin
angiotensin systems in this hypertension, suggesting a potential novel mechanism
of blood pressure regulation in this new murine hypertension model. Thus, Mpv17-/
mice unravel an intriguing new association between a defect in reactive oxygen
metabolism and the age-dependent development of hypertension.
PMID- 10673154
TI - Characterization of four distinct monoclonal antibodies specific to BmK AS-1, a
novel scorpion bioactive polypeptide.
AB - Four monoclonal antibodies designed as 2#, 3#, 4# and 5# have been raised against
a novel bioactive polypeptide BmK AS-1 purified from the Chinese scorpion Buthus
martensi Karsch. All of these antibodies exhibited specific affinity with antigen
by ELISA and Biosensor assay. Western blot analysis showed that 3# and 4# were
able to recognize the denatured antigen, but not 2# and 5#. These antibodies
could cross-react with BmK AS, but not with other types of BmK neurotoxins such
as BmK I (an alpha-like toxin) and BmK IT (an excitatory insect-selective toxin),
and in which only 5# can partially react with BmK IT2 (a depressant insect
selective toxin). Immunocytochemical staining demonstrated that 3#, 4# and 5#
antibodies can visualize the antigen bound to the membrane of SK-N-SH neuroblast
cells, with the exception of 2#. This suggests that either conformation
alteration of receptor binding might be prone to nonvisualization or the epitope
recognized by antibody 2# might be overlapped with receptor binding sites of
antigen. The antibodies developed in the study should provide powerful new tools
for investigating the structure/function relationship and pharmacological
mechanism of scorpion neurotoxins.
PMID- 10673155
TI - Monitoring of microcystin-protein phosphatase adduct formation with
immunochemical methods.
AB - Using anti-microcystin-LR monoclonal antibodies, an immunoblotting procedure was
developed to monitor the formation of microcystin-protein phosphatase adducts in
vitro and in vivo. The detection limits for the covalent binding of MCYST-LR with
the recombinant protein phosphatase 1 (PP1) and rabbit liver cytosol proteins
were found to be 0.1 ng and 0.3 ng per assay, respectively. MCYST-PP1 adducts
were detected 30 s after the addition of MCYST-LR into the reaction mixture.
Reduction of the methyldehydroalanine (Mdha) residue of MCYST-LR with ethanethiol
totally abolished the covalent binding of the toxin to PP1, but retained its
inhibitory toxicity on PP1. Immunoblotting analyses and enzyme-linked
immunosorbant assay showed that between 5 min to 16 h after i.p. injection of
single dose (35 microg/kg) of MCYST-LR into mice, approximately 0-27% of the
injected toxin was found covalently bound while 0.2-9.2% existed as free form in
liver cytosol.
PMID- 10673156
TI - Horse IgG isotypes and cross-neutralization of two snake antivenoms produced in
Brazil and Costa Rica.
AB - Horse IgG isotypes and cross-neutralization of two snake antivenoms produced in
Brazil and Costa Rica. Toxicon 000-000. This work compared the specificity, ELISA
titers and IgG subclass content of the polyvalent antivenom (anti-Bothrops asper,
Crotalus durissus durissus and Lachesis muta stenophrys) of Instituto Clodomiro
Picado (Costa Rica) and the bothropic antivenom (anti-Bothrops jararaca, B.
jararacussu, B. moojeni, B. neuwiedi and B. alternatus) of Instituto Butantan
(Brazil). The role of IgG(T) and IgGa subclasses in neutralization of some venom
toxic activities and the cross neutralization of the antivenoms against B.
jararaca and B. asper venoms were also evaluated. Both antivenoms were able to
recognize B. asper and B. jararaca venoms by immunoblotting and presented similar
antibody titers when assayed by ELISA. IgG(T) was highest, followed by IgGa, IgGb
and IgGc. IgGa and IgG(T) isotypes isolated from both antivenoms by affinity
chromatography were tested for neutralization of lethal, hemorrhagic, coagulant
and phospholipase A2 activities of the homologous venoms. In both antivenoms,
IgG(T) was the major isotype responsible for neutralization of all the tested
activities, followed by IgGa. These results suggest that Instituto Butantan and
Instituto Clodomiro Picado antivenoms have the same IgG profile and their
neutralizing ability is due mostly to the IgG(T) isotype. Also, they neutralize
lethality in mice induced by homologous and heterologous venoms, the bothropic
antivenom of Instituto Butantan being more effective.
PMID- 10673157
TI - The isolation and characterization of a peptide that alters sodium channels from
Buthus martensii Karsch.
AB - The peptides were purified using gel filtration, ion exchange, FPLC, and HPLC
chromatography and found to greatly prolong action potentials at nanomolar
concentrations when applied to frog and mouse nerves. The N-terminal primary
amino acid sequence of one of the peptides, BMK 16(5), was determined. The first
23 amino acids of BMK 16(5) were found to be: VKDGYIADDRNCPYFCGRNAYYD. The two
cysteine residues in the sequence appeared as Edman sequence cycle blanks;
however, they were assigned to be cysteines due to sequence similarity to other
peptide toxins that bind to sodium channels and identification of the presence of
cysteines obtained from single time point amino acid analysis. The MW of BMK
16(5) was determined by a Perkin Elmer API 300 LC/MS/MS to be 3,695. The amino
acid residues of BMK 16(5) show strong similarity with the first 23 amino acid
residues of a number of scorpion alpha neurotoxins. Unlike these neurotoxins, BMK
16(5) possesses a proline residue at position 13 which will likely make it fold
in a unique way so as to bind to and alter sodium channels.
PMID- 10673158
TI - The gene cloning and sequencing of Bm-12, a chlorotoxin-like peptide from the
scorpion Buthus martensi Karsch.
AB - According to the known amino acid sequence of Bm-12, a short chain insect
neurotoxin from the venom of the scorpion Buthus martensi Karsch (BmK) with
considerable primary sequence homology to chlorotoxin, the gene specific primers
were designed and synthesized for 3' and 5'RACE (Rapid Amplification of cDNA
Ends). The two partial cDNA fragments obtained by 3' and 5'RACE were cloned and
sequenced, and the full length cDNA sequence of Bm-12 was then completed by
overlapping these two partial cDNA sequences. The predicted amino acid sequence
consists of 59 amino acid residues including a putative signal peptide of 24
residues and a mature toxin of 35 residues. The predicted amino acid sequence of
Bm-12 was almost consistent with the determined, different only in one residue at
position 27, Lys was replaced by Gly. Based on the determined cDNA sequence, and
using the total DNA isolated from the scorpion venom glands as a template, the
genomic DNA of Bm-12 was also amplified by PCR and sequenced. The genomic DNA
sequence revealed an intron of 93 bp present within the signal peptide region.
PMID- 10673159
TI - Characterization of mice antisera elicited with a ciguatoxin tetracyclic
synthetic ring fragment (JKLM) conjugated to carrier proteins.
AB - As a good alternative to the lack of pure ciguatoxin (CTX), conjugates of JKLM
ring fragment, a carboxylic derivative of the right-hand tetracyclic terminus
portion of CTX-1B (the most potent CTX) with two carrier proteins have been
synthesized. Two procedures using different amount of hapten were evaluated: (i)
a bulk technique (3-5 mg) via the N-hydroxysuccinimide ester of the carboxylic
fragment in the presence of a water-soluble carbodiimide according to the
standard method in aqueous buffer, or (ii) a micro-scale technique (300 microg)
via the mixed anhydride method performed in a reversed micellar medium. In both
cases, bovine serum albumin and ovalbumin were respectively used for immunization
of BALB/c mice and antibody screening by a solid phase enzyme-linked
immunosorbent assay (ELISA). Using the conjugates obtained through the micro
scale procedure, a long-term immunization schedule appeared to be more efficient
to specifically trigger the mice immune system. These antisera titers determined
in an end-point titration standard ELISA format were found around 1/128,000 as
compared to 1/16,000 obtained in the short-term protocol (immunogen prepared via
the bulk procedure). In competitive inhibition ELISA experiments, both types of
antisera did not significantly cross-react with a brevetoxin congener (PbTx-3),
okadaic acid (OA), monensin or other polyether compounds, but only sera from the
short-term protocol did show high cross-reactivity to CTX-1B (133%). With sera
from the long-term protocol, a lower detection limit for JKLM (1.23 x 10(-9) M)
was achieved by implementation of a biotin-avidin amplification system rather
than by miniaturization of the assay in Terasaki plates. This study confirms the
feasibility of the immunological approach for CTXs assay in fish tissues, but
also emphasizes the importance of (i) the choice of the hapten to construct a
relevant well-defined immunogen, (ii) the immunization schedule to obtain hapten
specific Abs still exhibiting high cross-reactivity to CTXs.
PMID- 10673160
TI - Sea snake Hydrophis cyanocinctus venom. II. Histopathological changes, induced by
a myotoxic phospholipase A2 (PLA2-H1).
AB - A toxic phospholipase A2 (PLA2-H1), isolated from the venom of the sea snake
Hydrophis cyanocinctus, was tested for its ability to induce myonecrosis and
histopathological changes in albino rats and mice. Induction of myonecrosis was
demonstrated by their ability to release creatine kinase (CK) from damaged muscle
fibers and direct histopathological examination of the injected muscles (i.m.).
PLA2-H1 exhibits intense myonecrosis characterized by the changes including,
necrosis and edematous appearance with cellular infiltrate, vacuolation and
degenerated muscle cells with delta lesions and heavy edema in between the cells.
No myoglobinuria was noted in any group of animals. The purified PLA2-H1 was also
administered intraperitoneally into the experimental animals and tissue samples
were taken at several time intervals. Light microscopic examination of the kidney
sections revealed severe damage, evident by focal tubular necrosis, complete
disquamation of epithelial lining and epithelial degeneration of tubules in all
test animals. Light micrographs of liver sections after 24 h of injection shows
fatty infiltration in parenchyma and squashed hepatocytes, while after 48 h,
fatty vacuolation of parenchyma in a generalized pattern was observed.
Furthermore, sections of the lungs of the same group of animals (48 h) show
dilated bronchia and marked infiltration of inflammatory cells within alveoli.
Our results suggest that the purified PLA2-H1 induced moderate myotoxicity in
muscles and mild histopathological changes in other vital organs without
myoglobinuria.
PMID- 10673161
TI - Amino acid sequence and biological properties of the lectin from the venom of
Trimeresurus okinavensis (Himehabu).
AB - A lectin was isolated from the venom of Trimeresurus okinavensis (Himehabu) and
the complete amino acid sequence was determined using clostripain, lysyl
endopeptidase, and V8 protease. The hemagglutinating activity of this lectin are
reported.
PMID- 10673162
TI - California ground squirrel (Spermophilus beecheyi) blood sera inhibits crotalid
venom proteolytic activity.
AB - Some California ground squirrels (Spermophilus beecheyi) show limited necrosis
following envenomation by northern Pacific rattlesnakes (Crotalus viridis
oreganus). This study demonstrates that S. beecheyi blood sera inhibits venom
proteases. Sera from rattlesnake-abundant habitats inhibited C. v. oreganus venom
more effectively than venom from two allopatric rattlesnake species, C. v.
viridis and C. atrox, suggesting evolutionary specialization. The pattern of
inhibition among squirrel populations corresponds best with history of
rattlesnake predation, in contrast to current rattlesnake density.
PMID- 10673163
TI - Fang tip spread, puncture distance, and suction for snake bite.
AB - We measured the distance between fang tip punctures in defensive bites by western
diamondback rattlesnakes (Crotalus atrox) and the distance between their
retracted fangs. Because the fang tips at penetration average 112% further apart
than their bases at rest, The Extractor, a device widely marketed in the United
States for snake bite first aid, will not simultaneously cover both punctures of
most adult New World pitvipers.
PMID- 10673164
TI - Toxicities and distribution of tetrodotoxin in the tissues of puffer fish found
in the coast of the Baja California Peninsula, Mexico.
AB - Toxicities and tetrodotoxin distribution in tissues of five puffer fish species
commonly found in the littoral of Baja California Peninsula, Mexico (Sphoeroides
annulatus, S. lobatus, S. lispus, Arothron meleagris and Canthigaster
punctatissima) were evaluated by bioassay and HPLC. The toxicities estimated as
tetrodotoxin-equivalents of all species were more than 0.42 microg/g in at least
one of the tissues tested, and the highest was found in S. lispus liver (130
microg/g).
PMID- 10673165
TI - Inhaled corticosteroids are beneficial in chronic obstructive pulmonary disease.
PMID- 10673168
TI - Rebuttal from dr. barnes
PMID- 10673167
TI - Rebuttal from dr. calverley
PMID- 10673166
TI - Inhaled corticosteroids are not beneficial in chronic obstructive pulmonary
disease.
PMID- 10673169
TI - My initiation into respiratory physiology.
PMID- 10673170
TI - Upper airway collapsibility and cephalometric variables in patients with
obstructive sleep apnea.
AB - Increased pharyngeal collapsibility and abnormal anatomic structures have been
postulated to contribute to the pathophysiology of obstructive sleep apnea (OSA)
syndrome. It is unclear whether the abnormal craniofacial and soft tissue
features may affect the pharyngeal collapsibility and contribute to the apnea
density. In the present study we examine the relationship between pharyngeal
collapsibility and cephalometric variables in a group of 57 male OSA patients.
Pharyngeal collapsibility was measured during the night of nasal continuous
positive airway pressure (nCPAP) titration by analyzing the pressure-flow
relationship. Pharyngeal critical pressure (Pcrit) was calculated as the
extrapolated pressure at zero flow. The patients, age 52.0 +/- 9.0 yr, had an
average apnea-hypopnea index (AHI) of 72.6 +/- 31.8 and a mean Pcrit of 2.4 +/-
1.0 cm H(2)O. A significant correlation was found between Pcrit and the soft
palate length (SPl) (r = 0.27, p = 0.04), the distance from the hyoid bone to the
posterior pharyngeal wall (H-Ph) (r = 0. 29, p = 0.03), and the distance from the
hyoid bone to posterior nasal space (H-Pns) (r = 0.32, p = 0.02). While in obese
patients Pcrit was related to SPl and neck circumference, the distance of the
hyoid bone to the mandibular plane (H-MP) affected Pcrit in nonobese patients.
Our results show that both pharyngeal soft tissue abnormalities and the lower
position of the hyoid bone affect Pcrit in OSA patients, suggesting that an
anatomic narrowing contributes to the upper airway collapsibility.
PMID- 10673171
TI - Forced expiratory flows and volumes in infants. Normative data and lung growth.
AB - Forced expiratory flows (FEF) can be measured in infants from lung volumes
initiated near total lung capacity. In order to establish reference values and to
evaluate lung growth, we obtained measurements in 155 healthy subjects between 3
and 149 wk of age. Forced vital capacity (FVC) was highly correlated with body
length; however, after accounting for length, age was also significant. When
subjects were divided at the median age (40 wk) younger compared with older
subjects had a significantly larger slope for length (3.7 versus 2.8; p = 0.002).
The flow parameters (FEF(50), FEF(75), FEF(85), and FEF(25-75)) were highly
correlated with length, and those infants whose mothers smoked had lower flows.
For FEF(75), male subjects had lower flows than female subjects. The relationship
between FEF and volume was assessed using FEV(0.5)/FVC, which decreased with
increasing length. Smaller subjects emptied their lung volume proportionately
faster. We conclude that our study provides reference values for this age group
and demonstrates that smoke-exposed infants and male subjects have decreased FEF.
In addition, our findings indicate that lung volume increases most rapidly during
the first year of life and that airways are large relative to lung volume very
early in life.
PMID- 10673172
TI - Effect of the prone position on patients with hydrostatic pulmonary edema
compared with patients with acute respiratory distress syndrome and pulmonary
fibrosis.
AB - This study examined the effect of the prone position on mechanically ventilated
patients with hydrostatic pulmonary edema (HPE). Eight patients with acute HPE
and mechanically ventilated in the prone position (Group 1) were studied. Six
patients with acute HPE and mechanically ventilated in the supine position (Group
2), 20 patients with ARDS (Group 3), and 5 patients with pulmonary fibrosis (PF)
(Group 4) served as control patients. Patients with HPE, who after being
mechanically ventilated for at least 6 h needed an FI(O(2)) >/= 0.6 to achieve an
Sa(O(2)) of approximately 90%, and did not respond to recruitment maneuvers, were
turned to the prone position. Parameters of oxygenation, lung mechanics, and
hemodynamics were determined in both the supine and prone positions. All patients
with HPE exhibited improvement of oxygenation when they were placed in the prone
position. The Pa(O(2))/FI(O(2)) ratio increased from 72 +/- 16 in the supine
position to 208 +/- 61 after 6 h in the prone position (p < 0.001); the rise in
Pa(O(2)) was persistent, without detrimental effect on hemodynamics. Fifteen of
20 patients with ARDS (75%) improved oxygenation when in the prone position. The
Pa(O(2))/FI(O(2)) ratio increased from 83 +/- 14 in the supine position to 189 +/
34 after 6 h in the prone position (p < 0.001). In contrast, 5 of 20 patients
with ARDS (25%) and none of the patients with PF responded favorably to prone
positioning. Patients with HPE and early ARDS responded better to prone
positioning than did patients with late ARDS and PF. Patients with HPE and
ventilated in the supine position had a lower Pa(O(2))/FI(O(2)) ratio and the
duration of mechanical ventilation was longer compared with that of patients in
the prone position. Our results show that the prone position may be a useful
maneuver in treating patients with severe hypoxemia due to pulmonary edema. The
presence of pulmonary edema, as in early ARDS and HPE predicts a beneficial
effect of the prone position on gas exchange. In contrast, the presence of
fibrosis, as in late ARDS and pulmonary fibrosis, predisposes to
nonresponsiveness to prone positioning.
PMID- 10673173
TI - Effects of varying approaches for identifying respiratory disturbances on sleep
apnea assessment.
AB - Varying approaches to measuring the respiratory disturbance index (RDI) may lead
to discrepant estimates of the severity of sleep-disordered breathing (SDB). In
this study, we assessed the impact of varying the use of corroborative data
(presence and degree of desaturation and/or arousal) to identify hypopneas and
apneas. The relationships among 10 RDIs defined by various definitions of apneas
and hypopneas were assessed in 5,046 participants in the Sleep Heart Health Study
(SHHS) who underwent overnight unattended 12-channel polysomnography (PSG). The
magnitude of the median RDI varied 10-fold (i.e., 29.3 when the RDI was based on
events identified on the basis of flow or volume amplitude criteria alone to 2.0
for an RDI that required an associated 5% desaturation with events). The
correlation between RDIs based on different definitions ranged from 0.99 to 0.68.
The highest correlations were among RDIs that required apneas and hypopneas to be
associated with some level of desaturation. Lower correlations were observed
between RDIs that required desaturation as compared with RDIs defined on the
basis of amplitude criteria alone or associated arousal. These data suggest that
different approaches for measuring the RDI may contribute to substantial
variability in identification and classification of the disorder.
PMID- 10673174
TI - Time course of sleep-related breathing disorders in first-ever stroke or
transient ischemic attack.
AB - To investigate the prevalence and behavior of sleep-related breathing disorders
(SRBDs) associated with a first-ever stroke or transient ischemic attack (TIA),
we prospectively studied 161 consecutive patients admitted to our stroke unit.
Complete neurological assessment was performed to determine parenchymatous and
vascular localization of the neurological lesion. Stroke subtype was categorized
as TIA, ischemic (IS), or hemorrhagic (HS). A portable respiratory recording
(PRR) study was performed within 48-72 h after admission (acute phase), and
subsequently after 3 mo (stable phase). During the acute phase, 116 patients
(71.4%) had an apnea-hypopnea index (AHI) > 10 events/h and 45 (28%) had an AHI >
30. No relationships were found between sleep-related respiratory events and the
topographical parenchymatous location of the neurological lesion or vascular
involvement. Cheyne-Stokes breathing (CSB) was observed in 42 cases (26.1%).
There were no significant differences in SRBD according to the stroke subtype
except for the central apnea index (CAI). During the stable phase a second PRR
was performed in 86 patients: 53 of 86 had an AHI > 10 and 17 of 86 had an AHI >
30. The AHI and CAI were significantly lower than those in the acute phase (16.9
+/- 13.8 versus 22.4 +/- 17.3 and 3.3 +/- 7.6 versus 6.2 +/- 10.2, respectively)
(p < 0.05) while the obstructive apnea index (OAI) remained unchanged. CSB was
observed in 6 of 86 patients. The prevalence of SRBD in patients with first-ever
stroke or TIA is higher than expected from the available epidemiological data in
our country. No correlation was found between neurological location and the
presence or type of SRBD. Obstructive events seem to be a condition prior to the
neurological disease whereas central events and CSB could be its consequence.
PMID- 10673176
TI - Differential metabolism of arachidonic acid in nasal polyp epithelial cells
cultured from aspirin-sensitive and aspirin-tolerant patients.
AB - The mechanism of aspirin (acetylsalicylic acid [ASA]) sensitivity associated with
severe asthma and chronic rhinosinusitis with nasal polyps ("aspirin triad") has
been attributed to arachidonic metabolism alternations, although the putative
biochemical defects have not been elucidated. The aim of this study was
assessment of the hypothesis that local production of eicosanoids in the
respiratory epithelium in patients with ASA-sensitive asthma/rhinosinusitis
(ASARS) differs from that of ASA-tolerant patients with rhinosinusitis (ATRS).
Nasal polyps were obtained from 10 patients with ASARS and 15 with ATRS during
routine polypectomies, and epithelial cells (ECs) were cultured on bovine
collagen type I matrix (Vitrogen 100), in medium supplemented with growth
factors. The generation of eicosanoids in supernatants of confluent ECs (6 to 8 d
of culture; purity > 98%) was quantified by immunoassays. Unstimulated ECs from
ASARS patients generated significantly less prostaglandin E(2)(PGE(2)) compared
with ATRS (0.8 +/- 0.3 versus 2. 4 +/- 0.5 ng/microg double-stranded
deoxyribonucleic acid [dsDNA], respectively), although a similar relative
increase in response to calcium ionophore and inhibition with ASA was observed in
both groups. Basal levels of 15-hydroxyeicosatetraenoic acid (15-HETE) were not
different between groups, and calcium ionophore enhanced its production to a
similar extent. However, cells incubation with 200 microM ASA for 60 min resulted
in a significant increase (mean +359%) in 15-HETE generation only in ASARS
patients, whereas no effect of ASA on 15-HETE generation in ATRS patients was
observed. PGF(2alpha) generation was similar in both groups, and no significant
generation of PGD(2) or leukotriene C(4) (LTC(4)) was observed in epithelial cell
cultures from either group. Our results indicate that nasal polyps ECs from ASA
sensitive patients have significant abnormality in basal and ASA-induced
generation of eicosanoids which may be causally related to the mechanism of ASA
sensitivity.
PMID- 10673177
TI - Activation of neutrophils, eosinophils, and lymphocytes in the lower respiratory
tract in Wegener's granulomatosis.
AB - Levels of cell products released by neutrophils, eosinophils and lymphocytes were
measured in the bronchoalveolar lavage fluid (BALF) of 19 patients with pulmonary
active Wegener's granulomatosis (WG) to assess in vivo the magnitude of cellular
activation at sites of active disease. Measurements included the BAL cell profile
and BALF levels of myeloperoxidase (MPO), free proteinase 3 (fPR3), complexes of
PR3 and alpha1-antitrypsin (PR3/alpha1-AT), eosinophil cationic protein (ECP),
peroxidase activity (PEROX), and soluble interleukin-2 receptor (sIL-2R). Six
patients also underwent a repeat examination after immunosuppressive treatment.
Pulmonary active WG was found to be associated with elevated MPO, PEROX, ECP, and
sIL-2R levels in BALF. Only trace amounts of fPR3 were detected, the bulk of PR3
being found in PR3/alpha1-AT complexes. Clinically effective treatment depressed
BAL neutrophil counts and reversed elevated levels of MPO and PEROX but had an
inconsistent effect on the BAL lymphocyte count and the sIL-2R level. In
conclusion, the elevated levels of extracellular MPO and PEROX at a site of
active disease and the correlation between these and clinical disease activity
support the view that neutrophils are indeed an important effector cell
population in WG lung disease. The present data also suggest that oxidative
injury is an important aspect of neutrophil-mediated lung injury, whereas it
remains unresolved whether the low levels of fPR3 in the BALF adequately reflect
the situation at inflammatory tissue sites.
PMID- 10673175
TI - Smoking cessation and lung function in mild-to-moderate chronic obstructive
pulmonary disease. The Lung Health Study.
AB - Previous studies of lung function in relation to smoking cessation have not
adequately quantified the long-term benefit of smoking cessation, nor established
the predictive value of characteristics such as airway hyperresponsiveness. In a
prospective randomized clinical trial at 10 North American medical centers, we
studied 3, 926 smokers with mild-to-moderate airway obstruction (3,818 with
analyzable results; mean age at entry, 48.5 yr; 36% women) randomized to one of
two smoking cessation groups or to a nonintervention group. We measured lung
function annually for 5 yr. Participants who stopped smoking experienced an
improvement in FEV(1) in the year after quitting (an average of 47 ml or 2%). The
subsequent rate of decline in FEV(1) among sustained quitters was half the rate
among continuing smokers, 31 +/- 48 versus 62 +/- 55 ml (mean +/- SD), comparable
to that of never-smokers. Predictors of change in lung function included
responsiveness to beta-agonist, baseline FEV(1), methacholine reactivity, age,
sex, race, and baseline smoking rate. Respiratory symptoms were not predictive of
changes in lung function. Smokers with airflow obstruction benefit from quitting
despite previous heavy smoking, advanced age, poor baseline lung function, or
airway hyperresponsiveness.
PMID- 10673178
TI - Long-term follow-up of pulmonary function in patients with nasal polyposis.
AB - The outcome of asthma and/or nonspecific bronchial hyperresponsiveness (BHR)
associated with nasal polyposis (NP) is uncertain. Over a 4-yr period, we
investigated the long-term changes of pulmonary function and BHR in 46 patients
with NP. Each subject was assessed for nasal symptoms and tested for allergy skin
prick tests, serum total IgE, spirometry, and carbachol challenge at baseline
before initiating any treatment (T0). Nasal symptoms evaluation, spirometric
measurements, and carbachol challenge were repeated at T1 and at T2
(respectively, 12.7 +/- 0.9 and 47.9 +/- 2. 2 mo after T0). In addition,
bronchodilator response was measured at T2. At T0, 25 patients exhibited BHR and
16 of 25 were asthmatic. All patients were treated first with topical steroids
for 6 wk (beclomethasone 600 microg/d). Eighteen patients were successfully
treated with topical steroids (topical steroids responders). Intranasal
ethmoidectomy was performed in 28 patients who did not improve with topical
steroids alone (topical steroids nonresponders). Nasal score improved at T1 and
remained improved at T2 as compared with T0 in both groups (p < 0.005). Topical
steroids nonresponders demonstrated a significant decrease of FEV(1), FEV(1)/FVC
ratio, and FEF(25-75) at T1 (p < 0.05) and at T2 (p < 0.0005), whereas no
significant change was observed in FEV(1) and FEV(1)/FVC ratio in responders.
DeltaFEV(1) (%) between T2 and T0 was not related to the presence of asthma, BHR,
or atopy. Bronchodilator response at T2 was similar in the two groups. BHR did
not significantly change over the 4-yr follow-up period in the two groups. No
change in pulmonary symptoms and/or asthma severity occurred. Our results show
that nonreversible airflow obstruction appears over a 4-yr follow-up period in
topical steroids nonresponders patients with NP requiring nasal surgery. The long
term contribution of these changes to the development of respiratory symptoms in
patients with NP remains to be documented.
PMID- 10673179
TI - The effects of chronic alcohol abuse on pulmonary glutathione homeostasis.
AB - The incidence and severity of the acute respiratory distress syndrome (ARDS) is
increased in critically ill patients with a prior history of chronic alcohol
abuse; however, the specific mechanisms responsible for this association are
unknown. Recently, we determined that chronic ethanol ingestion in rats decreased
the alveolar epithelial lining fluid (ELF) concentration of the antioxidant
glutathione (GSH), which is a characteristic finding in patients with ARDS.
However, the effects of chronic alcohol abuse on the human alveolar epithelium
are essentially unknown. Therefore, as a first step we asked if chronic alcohol
abuse, independent of other comorbid conditions, decreases the concentration of
GSH in the human lung. We determined that otherwise healthy chronic alcoholics
had significantly decreased ELF concentrations of GSH compared with nonalcoholic
control subjects (79 micromol [48 to 118 micromol] versus 576 micromol [493 to
728 mmol], p < 0.001). Furthermore, the percentage of GSH in the oxidized form
was higher in the chronic alcoholics (9.8% [2.2 to 14.8%] versus 2.8% [0.4 to
4.0%] p = 0.05), indicative of increased utilization of GSH. This is the first
report that chronic alcohol abuse alters GSH homeostasis in the human lung, and
suggests a potential mechanism by which chronic alcohol abuse predisposes
susceptible patients to develop ARDS.
PMID- 10673180
TI - An oral elastic mandibular advancement device for obstructive sleep apnea.
AB - Oral mandibular advancement devices are becoming an increasingly important
treatment alternative for obstructive sleep apnea (OSA). The first aim of the
study was to determine whether a new oral elastic mandibular advancement device
(EMA) prevents pharyngeal airway closure during sleep in patients with OSA. The
second aim of the study was to determine if the polysomnographic response to the
oral mandibular advancement device was dependent on the site of airway closure.
Overnight polysomnograms were performed in 28 untreated OSA subjects with and
without EMA. A third polysomnogram was performed in 12 of the subjects to
determine the site of airway closure without the device. Site of airway closure
above or below the oropharynx was determined by measuring the respective presence
or absence of respiratory fluctuations in oropharyngeal pressure during induced
occlusions in non-rapid eye movement (NREM) sleep. Mean apnea-hypopnea index
(AHI) was 52.6 +/- 28.2 (SD) events/h without the device and 21.2 +/- 19.3
events/h with the device. Nineteen subjects (68%) had at least a 50% reduction in
AHI with the device. The change in AHI with the device (AHI without device - AHI
with device) was directly related to the AHI without the device. All three
subjects with airway closure in the lower pharyngeal airway had a greater than
80% reduction in AHI with the device. Two of the nine subjects with airway
closure in the velopharynx had a similar therapeutic response. The results show
the effectiveness of EMA in the treatment of OSA. The results also indicate that
polysomnographic severity of OSA and the site of airway closure should not be
used to exclude patients from this oral device treatment.
PMID- 10673181
TI - Sleep onset REM periods during multiple sleep latency tests in patients evaluated
for sleep apnea.
AB - Although 2 or more sleep onset rapid eye movement (REM) periods (2omSOREMPs) on a
Multiple Sleep Latency Test (MSLT) raise the possibility of narcolepsy, patients
with obstructive sleep apnea (OSA) also can have 2omSOREMPs, which may then cause
diagnostic uncertainty. To explore what features among OSA patients predict
2omSOREMPs on an MSLT that follows nocturnal polysomnography, we reviewed data
from 1,145 consecutively studied patients suspected or confirmed to have OSA
rather than narcolepsy. Overall, 4.7% of the subjects had 2omSOREMPs. Variables
that were independently predictive of 2omSOREMPs in logistic regression models
included male gender (OR = 4.4, 95% CI = 1.9 to 12.7), a 5-min decrease in the
MSLT-derived mean sleep latency (OR = 1.9, 95% CI = 1.3 to 2.8), a 90-min
decrease in nocturnal latency to REM sleep (OR = 1.6, 95% CI = 1.1 to 2.5), and a
15-unit decrease in minimal recorded oxygen saturation (OR = 1.6, 95% CI = 1.3 to
2.0). We conclude that among patients suspected or confirmed to have OSA, one or
more of these four variables-male sex, sleepiness, nocturnal REM sleep latency,
and extent of oxygen desaturation-could reflect neurophysiological mechanisms
responsible for 2omSOREMPs. Consideration of these variables, and especially
gender, may be useful in clinical practice when 2omSOREMPs are found
unexpectedly.
PMID- 10673182
TI - An objective analysis of the pressure-volume curve in the acute respiratory
distress syndrome.
AB - To assess the interobserver and intraobserver variability in the clinical
evaluation of the quasi-static pressure-volume (P-V) curve, we analyzed 24 sets
of inflation and deflation P-V curves obtained from patients with ARDS. We used a
recently described sigmoidal equation to curve-fit the P-V data sets and
objectively define the point of maximum compliance increase of the inflation limb
(P(mci, i)) and the true inflection point of the deflation limb (P(inf,d)). These
points were compared with graphic determinations of lower Pflex by seven
clinicians. The graphic and curve-fitting methods were also compared for their
ability to reproduce the same parameter value in data sets with reduced number of
data points. The sigmoidal equation fit the P-V data with great accuracy (R(2) =
0.9992). The average of Pflex determinations was found to be correlated with
P(mci,i) (R = 0.89) and P(inf,d) (R = 0.76). Individual determinations of Pflex
were less correlated with the corresponding objective parameters (R = 0.67 and
0.62, respectively). Pflex + 2 cm H(2)O was a more accurate estimator of P(inf,d)
(2 SD = +/-6.05 cm H(2)O) than Pflex was of P(mci,i) (2 SD = +/-8.02 cm H(2)O).
There was significant interobserver variability in Pflex, with a maximum
difference of 11 cm H(2)O for the same patient (SD = 1.9 cm H(2)O). Clinicians
had difficulty reproducing Pflex in smaller data sets with differences as great
as 17 cm H(2)O (SD = 2.8 cm H(2)O). In contrast, the curve-fitting method
reproduced P(mci,i) with great accuracy in reduced data sets (maximum difference
of 1.5 cm H(2)O and SD = 0.3 cm H(2)O). We conclude that Pflex rarely coincided
with the point of maximum compliance increase defined by a sigmoid curve-fit with
large differences in Pflex seen both among and within observers. Calculating
objective parameters such as P(mci,i) or P(inf,d) from curve-fitted P-V data can
minimize this large variability.
PMID- 10673183
TI - Effects of isoproterenol on diaphragmatic contractility in septic peritonitis.
AB - We investigated the effects, and the mechanism of the effects, of isoproterenol
on diaphragmatic contractility and fatigue in septic peritonitis in vitro. Ninety
six rats were divided into two groups of 48. One group (CLP group) was treated
with cecal ligation and perforation (CLP) and the other (sham group) was treated
with laparotomy. The left hemidiaphragm was removed at 16 h after the operation.
We assessed the diaphragmatic contractility by twitch characteristics and force
frequency curves in vitro. Diaphragm fatigue was induced by rhythmically
stimulating strips to contract at 60/ min (20 Hz, 0.33-s trains, 1 train/s) over
a 4-min period. Force-frequency curves were determined before and after fatigue.
Isoproterenol (10(-9), 10(-8), and 10(-7) M), a beta-adrenoceptor agonist, was
cumulatively administered to the organ bath. Isoproterenol significantly
increased diaphragmatic contractility. There were no significant changes in
diaphragmatic contractility in the sham group. Isoproterenol (10(-7) M)
significantly accelerated diaphragmatic recovery of fatigue and increased cAMP
levels both in the sham group and the CLP group. Propranolol (10(-7) M), a
general beta-adrenoceptor blocker, completely abolished the positive inotropic
effect of isoproterenol (10(-7) M) and increased cAMP levels in the CLP group.
Dibutyryl cAMP (10(-3) M), a derivative of cyclic AMP, mimicked the effects of
isoproterenol in the CLP group. These results suggest that isoproterenol
increases diaphragmatic contractility and accelerates diaphragmatic recovery of
fatigue in septic peritonitis by activating the adenylate cyclase system.
PMID- 10673184
TI - Quadriceps fatigue after cycle exercise in patients with chronic obstructive
pulmonary disease.
AB - Patients with COPD have derangements in respiratory mechanics that may cause them
to stop exercising before the exercising limb muscles reach their functional
limits. However, because lung disease makes activity unpleasant, patients with
chronic obstructive pulmonary disease (COPD) often adapt a sedentary lifestyle
leading to progressive deconditioning. Deconditioning will lead to progressive
deterioration in limb muscle function, which could adversely affect exercise
capacity. The purpose of this study was to determine whether fatigue of the
quadriceps muscle occurs after high intensity cycle exercise to the limits of
tolerance in patients with moderate to severe COPD. Nineteen male patients with
COPD (FEV(1) 1.54 +/- 0. 12 L; 42 +/- 3% predicted) exercised at 60 to 70% of
their predetermined maximal work capacity until exhaustion. The femoral nerve was
supramaximally stimulated with a figure-of-eight magnetic coil, and quadriceps
twitch force (TwQ) was measured before and at 10, 30, and 60 min postexercise.
Patients exercised at 53.7 +/- 4.1 watts for 10.4 +/- 1.4 min. Peak V O(2) was
1.24 +/- 0.08 L/min (51. 3 +/- 3.6% predicted). TwQ fell significantly
postexercise; 79.2 +/- 5.4% of baseline value at 10 min postexercise (p < 0.005),
75.7 +/- 4.8% at 30 min postexercise (p < 0.001), and 84.0 +/- 5.0% at 60 min
postexercise (p < 0.005). Acceptable M-waves from the quadriceps muscle (not
obscured by stimulus artifact) were obtained in six subjects. M-wave amplitude
was unchanged from baseline at all times postexercise indicating that the fall in
TwQ was due to contractile fatigue and not to transmission failure. In
conclusion, contractile fatigue of the quadriceps muscle occurs after high
intensity cycle exercise to the limits of tolerance in patients with COPD.
PMID- 10673185
TI - Alveolar fibrin formation caused by enhanced procoagulant and depressed
fibrinolytic capacities in severe pneumonia. Comparison with the acute
respiratory distress syndrome.
AB - Changes in the alveolar hemostatic balance in severe pneumonia were compared with
those in the acute respiratory distress syndrome (ARDS). Analysis was performed
in bronchoalveolar lavage fluids (BALF) of patients with ARDS triggered by
nonpulmonary underlying events in the absence of lung infection (ARDS; n = 25),
pneumonia demanding mechanical ventilation (PNEU-vent; n = 114), spontaneously
breathing patients with pneumonia (PNEU-spon; n = 40), and ARDS in combination
with lung infection (ARDS+PNEU; n = 43); comparison with healthy control subjects
(n = 35) was performed. In all groups of patients, BALF total procoagulant
activity was increased by nearly two orders of magnitude, being largely
attributable to the tissue factor pathway of coagulation. Concomitantly, markedly
reduced overall fibrinolytic capacity (fibrin plate assay) was noted in the
lavage fluids of all patients. BALF levels of urokinase-type plasminogen
activator were significantly reduced throughout, whereas the lavage
concentrations of tissue-type plasminogen activator did not differ from those in
control subjects. In addition, markedly enhanced levels of plasminogen activator-
inhibitor I and alpha(2)-antiplasmin were noted in ARDS, ARDS+PNEU, and PNEU
vent, but not in PNEU-spon. In all groups of patients, the changes in the lavage
enzymatic activities were paralleled by manifold increased BALF concentrations of
fibrinopeptide A and D-dimer, reflecting in vivo coagulation processes. Within
the overall number of patients with pneumonia, changes in the alveolar hemostatic
balance were more prominent in alveolar and interstitial pneumonia than in
bronchopneumonia. Acute inflammatory lung injury, whether triggered by
nonpulmonary systemic events or primary lung infection, is thus consistently
characterized by both enhanced procoagulant and depressed fibrinolytic activities
in the alveolar lining layer, with the appearance of fibrin formation in this
compartment. Profile and extent of changes in severe pneumonia demanding
respirator therapy are virtually identical to those in ARDS, whereas somewhat
less prominent alterations of the alveolar hemostatic balance are noted in
spontaneously breathing patients with pneumonia.
PMID- 10673186
TI - Effects of decreased respiratory frequency on ventilator-induced lung injury.
AB - To determine if decreased respiratory frequency (ventilatory rate) improves
indices of lung damage, 17 sets of isolated, perfused rabbit lungs were
ventilated with a peak static airway pressure of 30 cm H(2)O. All lungs were
randomized to one of three frequency/peak pulmonary artery pressure combinations:
F20P35 (n = 6): ventilatory frequency, 20 breaths/min, and peak pulmonary artery
pressure, 35 mm Hg; F3P35 (n = 6), ventilatory frequency, 3 breaths/min, and peak
pulmonary artery pressure of 35 mm Hg; or F20P20 (n = 5), ventilatory frequency,
20 breaths/min, and peak pulmonary artery pressure, 20 mm Hg. Mean airway
pressure and tidal volume were matched between groups. Mean pulmonary artery
pressure and vascular flow were matched between groups F20P35 and F3P35. The
F20P35 group showed at least a 4.5-fold greater mean weight gain and a 3-fold
greater mean incidence of perivascular hemorrhage than did the comparison groups,
all p = 0.05. F20P35 lungs also displayed more alveolar hemorrhage than did
F20P20 lungs (p = 0.05). We conclude that decreasing respiratory frequency can
improve these indices of lung damage, and that limitation of peak pulmonary
artery pressure and flow may diminish lung damage for a given ventilatory
pattern.
PMID- 10673187
TI - Association of beta(2)-adrenoreceptor variants with bronchial
hyperresponsiveness.
AB - Because of its involvement in the regulation of airway tone, the beta(2)
adrenoreceptor is considered a candidate for bronchial hyperresponsiveness (BHR)
associated with asthma. This notion is supported by several reports that have
implicated the chromosomal region 5q31-q33 harboring the gene for the beta(2)
adrenoreceptor in the genetics of asthma and related phenotypes. We performed a
population-based association study focusing on BHR as a qualitative trait and
omitting other asthma-related phenotypes. From a German population sample of
1,150 individuals we extracted all 152 bronchohyperreactive probands, who were
compared with 295 bronchonormoreactive control subjects. All individuals were
genotyped for three single nucleotide polymorphisms of the beta(2)-adrenoreceptor
gene resulting in variants at the amino acid positions 16, 27, and 164. The
genotyping protocol used allowed the determination of haplotypes of these
polymorphisms. Whereas no individual polymorphism was associated with BHR, the
Gly16/Gln27/Th164 haplotype was significantly underrepresented in the case group
indicating a protective effect of this haplotype with regard to BHR. Upon
reanalysis by sex a significant association persisted only for female probands.
PMID- 10673188
TI - Induced sputum cell counts in healthy adults.
AB - Induced sputum cell counts provide a relatively noninvasive method to evaluate
the presence, type, and degree of inflammation in the airways of the lungs. Their
interpretation requires a knowledge of normal values from a healthy population.
The objective was to examine the total and differential cell counts in induced
sputum from a sample of healthy adults. A total of 118 healthy nonsmoking adults
were studied. None had asthma or airflow obstruction (negative history, FEV(1)
>/= 80% predicted, ratio of FEV(1) to vital capacity [FEV(1)/VC] >/= 80%,
methacholine PC(20) >/= 16 mg/ml). Forty-six were atopic. Sputum induction
produced an adequate sample in 96 subjects [53 males, mean age (range) 36 (18 to
60) yr]. The expectorate was processed within 2 h; sputum was selected, treated
with dithiothreitol, filtered, and examined in a hemocytometer for total cell
count and viability and on Wright-stained cytospins for a differential cell
count. The mean, median (90th percentile) total cell count was 4.1, 2.4 (9.7) x
10(6) cells/g and cell viability was 69.6, 72.0 (89.7)%. The proportions of
eosinophils were 0.4, 0.0 (1.1)%, neutrophils 37.5, 36.7 (64.0)%, macrophages
58.8, 60.8 (86.1)%, lymphocytes 1.0, 0.5 (2.6)%, metachromatic cells 0.0, 0.0
(0.04)%, and bronchial epithelial cells 1.6, 0.3 (4.4)%, respectively. Female
gender and atopy were associated with a significant elevation of eosinophils;
mean difference between male/female was 0.3% (p = 0.043) and between
atopic/nonatopic 0.4% (p = 0.024). This study has identified reference values for
total and differential cell counts in induced sputum of healthy adults.
PMID- 10673189
TI - No effect of inhaled budesonide on the response to inhaled ozone in normal
subjects.
AB - Inhalation of ozone in normal subjects causes a neutrophilic inflammatory
response in the airways. Pretreatment with inhaled corticosteroids reduces the
inflammatory response to inhaled ozone in dogs. We undertook a double-blind,
randomized, placebo-controlled, crossover study to investigate the effects of 2
wk of treatment with inhaled budesonide 800 microg twice daily or placebo prior
to ozone exposure in humans. Fifteen (six male; mean age, 31.1 +/- 2.1 yr)
healthy nonsmokers were exposed to 400 parts per billion (ppb) ozone for 2 h with
intermittent exercise. Spirometry, exhaled carbon monoxide (CO) and nitric oxide
(NO) levels, measurement of methacholine reactivity, and collection of exhaled
air condensate and induced sputum samples were performed at baseline,
preexposure, and at intervals up to 24 h postexposure. Ozone exposure led to
significant decreases in spirometry and increased methacholine reactivity and
sputum neutrophils and myeloperoxidase (MPO). There were no changes in exhaled NO
and CO levels, or exhaled breath nitrite after ozone exposure. There were no
differences in any of the parameters after treatment with budesonide compared
with placebo, and no differences in the response to ozone between treatment
groups. We conclude that a high dose of inhaled corticosteroid does not protect
against the effects of ozone exposure in normal subjects.
PMID- 10673190
TI - Clinical correlates and prognostic significance of six-minute walk test in
patients with primary pulmonary hypertension. Comparison with cardiopulmonary
exercise testing.
AB - The six-minute walk test is a submaximal exercise test that can be performed even
by a patient with heart failure not tolerating maximal exercise testing. To
elucidate the clinical significance and prognostic value of the six-minute walk
test in patients with primary pulmonary hypertension (PPH), we sought (1) to
assess the relation between distance walked during the six-minute walk test and
exercise capacity determined by maximal cardiopulmonary exercise testing, and (2)
to investigate the prognostic value of the six-minute walk test in comparison
with other noninvasive parameters. The six-minute walk test was performed in 43
patients with PPH, together with echocardiography, right heart catheterization,
and measurement of plasma epinephrine and norepinephrine. Symptom-limited
cardiopulmonary exercise testing was performed in a subsample of patients (n =
27). Distance walked in 6 min was significantly shorter in patients with PPH than
in age- and sex-matched healthy subjects (297 +/- 188 versus 655 +/- 91 m, p < 0.
001). The distance significantly decreased in proportion to the severity of New
York Heart Association functional class. The distance walked correlated modestly
with baseline cardiac output (r = 0.48, p < 0.05) and total pulmonary resistance
(r = -0.49, p < 0. 05), but not significantly with mean pulmonary arterial
pressure. In contrast, the distance walked correlated strongly with peak V O(2)
(r = 0.70, p < 0.001), oxygen pulse (r = 0.57, p < 0.01), and V E-VCO(2) slope (r
= -0.66, p < 0.001) determined by cardiopulmonary exercise testing. During a mean
follow-up period of 21 +/- 16 mo, 12 patients died of cardiopulmonary causes.
Among noninvasive parameters including clinical, echocardiographic, and
neurohumoral parameters, only the distance walked in 6 min was independently
related to mortality in PPH by multivariate analysis. Patients walking < 332 m
had a significantly lower survival rate than those walking farther, assessed by
Kaplan-Meier survival curves (log-rank test, p < 0.01). These results suggest
that the six-minute walk test, a submaximal exercise test, reflects exercise
capacity determined by maximal cardiopulmonary exercise testing in patients with
PPH, and it is the distance walked in 6 min that has a strong, independent
association with mortality.
PMID- 10673191
TI - Chlamydia pneumoniae serology, lung function decline, and treatment for
respiratory disease.
AB - Associations have been reported between Chlamydia pneumoniae seropositivity and
both acute and chronic obstructive airway diseases. Plasma specimens collected
between 1979 and 1983 from 1, 773 men 45 to 59 yr of age in Caerphilly, South
Wales, were tested for IgG and IgA antibodies to C. pneumoniae (TW183) by
microimmunofluorescence. Subsequent mortality and medication for obstructive
airway disease were ascertained at 5-yr follow-up examinations. Spirometry was
performed at the first and second examinations and analyzed both cross
sectionally and longitudinally; 642 men (36%) had IgG antibodies at a titer of
1:16 or above, of whom 362 also had detectable IgA antibodies. No statistically
significant associations were found between either IgG titer or IgA titer and any
of the outcome measures: inhaler therapy at entry; commencement of inhalers
during follow-up; death from respiratory causes; baseline FEV(1), FVC, and
FEV(1)/FVC ratio; and decline in FEV(1) (p > 0.1 throughout). Men with high IgG
titers (>/= 1:64) had a slower rate of decline of FEV(1) than did seronegative
subjects (adjusted mean difference in 5-yr change in FEV(1): +22 ml, 95%
confidence interval: -31 ml to +76 ml). Men with high IgA titers (>/= 1:16) had a
slightly faster rate of decline (-12 ml, - 96 ml to +71 ml). This first
prospective assessment suggests that chronic C. pneumoniae infection is not a
major risk factor for progressive airflow obstruction.
PMID- 10673192
TI - Symptoms, quality of life, and health service contact among young adults with
mild asthma.
AB - This report assesses Quality of Life (QoL) and its relationship to current
symptoms and prospective medical contact among 396 adult patients with asthma.
Patients were 16 to 52 yr of age and in the care of family physicians in the
northeast of Scotland. All patients had been prescribed asthma medication within
the previous 3 mo. Mean %pred FEV(1) was 87.4, mean %pred PEF was 85.1; 41%
reported respiratory symptoms every week in the month before interview. Patients
completed the SF-36, SF-12, and St. George's Respiratory Questionnaire (SGRQ)
scales. Although mean scores on the SF-36 and SF-12 were close to population
norms for patients without chronic illness, the presence of any respiratory
symptoms in the month before interview was related to significantly lower QoL
scores on the SF-36 scales of Physical Functioning, Energy, Mental Health, Pain,
and Health Perception: the SF-12 Physical Functioning scale, and the SGRQ
Symptoms, Impact and Activities scales. Physician contact for asthma in the 12 mo
after interview was significantly related to SF-36, SF-12, and SGRQ scores at
time of interview; however, when adjusted for symptoms at time of interview, only
the SGRQ scales remained significant predictors of prospective physician contact.
We conclude that respiratory symptoms have significant impact on QoL among
patients with mild asthma, measured by generic and respiratory QoL scales, but
that a specific respiratory scale is better able to discriminate patients who
will seek physician care for asthma.
PMID- 10673193
TI - Asthma mortality in U.S. Hispanics of Mexican, Puerto Rican, and Cuban heritage,
1990-1995.
AB - We used national vital statistics data for 1990 through 1995 to examine both
national and regional age-adjusted asthma mortality rates for U.S. Hispanics of
Mexican, Cuban, and Puerto Rican heritage, as well as for non-Hispanic whites and
non-Hispanic blacks. Nationally, Puerto Ricans had an age-adjusted annual asthma
mortality rate of 40.9 per million, followed by Cuban-Americans (15. 8 per
million) and Mexican-Americans (9.2 per million). In comparison, non-Hispanic
whites had an age-adjusted annual asthma mortality rate of 14.7 per million and
non-Hispanic blacks had a rate of 38.1 per million. Age-adjusted asthma mortality
for Puerto Ricans was highest in the Northeast (47.8 per million); this region
accounted for 81% of all asthma deaths among Puerto Ricans in the United States.
In the U.S., Puerto Ricans had the highest asthma mortality rates among
Hispanics, followed by Cuban-Americans and Mexican-Americans. In addition, among
Hispanic national groups, mortality rates were consistently higher in the
Northeast than the Midwest, South, or West regions. These results further support
that Hispanics do not represent a uniform, discrete group in terms of health
outcomes, and that further public health research and interventions should take
Hispanic national origin into account.
PMID- 10673194
TI - Response of the canine inspiratory intercostal muscles to chest wall vibration.
AB - High-frequency mechanical vibration of the rib cage reduces dyspnea, but the
effect of this procedure on the respiratory muscles is largely unknown. In the
present studies, we have initially assessed the electrical and mechanical
response to vibration (40 Hz) of the canine parasternal and external intercostal
muscles (third interspace) during hyperventilation-induced apnea. When the
vibrator was applied to the segment investigated, prominent external intercostal
activity was recorded in the seven animals studied, whereas low-amplitude
parasternal intercostal activity was recorded in only four animals. Similarly,
when the vibrator was applied to more rostral and more caudal interspaces,
activity was recorded commonly from the external intercostal but only
occasionally from the parasternal. The two muscles, however, showed similar
changes in length. We next examined the response to vibration of the muscles in
seven spontaneously breathing animals. Vibrating the rib cage during inspiration
(in-phase) had no effect on parasternal intercostal inspiratory activity but
induced a marked increase in neural drive to the external intercostals. For the
animal group, peak external intercostal activity during the control, nonvibrated
breaths averaged (mean +/- SE) 43.1 +/- 3.7% of the activity recorded during the
vibrated breaths (p < 0.001). External intercostal activity during vibration also
occurred earlier at the onset of inspiration and commonly carried on after the
cessation of parasternal intercostal activity. Yet tidal volume was unchanged.
Vibrating the rib cage during expiration (out-of-phase) did not elicit any
parasternal or external intercostal activity in six animals. These observations
thus indicate that the external intercostals, with their larger spindle density,
are much more sensitive to chest wall vibration than the parasternal
intercostals. They also suggest that the impact of this procedure on the
mechanical behavior of the respiratory system is relatively small.
PMID- 10673195
TI - Impaired hepatic extraction and increased splanchnic production contribute to
lactic acidosis in canine sepsis.
AB - In septic shock, the extent to which lactic acidosis (LA) is a consequence of
splanchnic lactate overproduction (SLP) or impaired hepatic lactate extraction
(HLE) is not clear. We examined SLP and HLE in E. coli sepsis in dogs. We further
determined the effects of vasopressor treatments, which included phenylephrine,
dopamine, norepinephrine, and a combination of dobutamine and norepinephrine
treatment, on SLP and HLE in respective groups. The animals were studied while
anesthetized and ventilated. During sepsis, SLP increased as compared with
presepsis (-0.017 versus 0.07 mmol/min, p < 0.05), but this increase could not be
explained by reduced splanchnic oxygen delivery (SOD). During sepsis, HLE
increased as compared with baseline (0.8 versus 8%, p < 0.05), but was
significantly lower than that found during lactic acid loading in nonseptic dogs.
None of the vasopressor treatments had a detrimental effect on SLP. These results
indicate that LA in sepsis occurs secondary to an increase in splanchnic lactate
production that is not related to reduced splanchnic oxygen delivery, as well as
to a decrease in hepatic lactate extraction. Effects of different vasoactive
agents did not alter either splanchnic lactate production or hepatic lactate
extraction in this sepsis model.
PMID- 10673196
TI - Combined salmeterol 50 microg and fluticasone propionate 250 microg in the diskus
device for the treatment of asthma.
AB - Three hundred forty-nine patients with asthma previously treated with medium
doses of inhaled corticosteroids during a 2-wk, single-blind, run-in period were
randomized to treatment with salmeterol 50 microg combined with fluticasone
propionate (FP) 250 microg, salmeterol 50 microg, FP 250 microg, or placebo, each
given twice daily through a Diskus device for 12 wk. Mean change in FEV(1) at
endpoint was significantly (p = 0.001) greater with the salmeterol/FP
combination product (0.48 L) than with placebo (-0.11 L), salmeterol (0.05 L), or
FP (0.25 L). The combination product significantly increased the area under the
12-h serial FEV(1) curve relative to baseline over that with placebo, salmeterol,
or FP at Day 1, Week 1, and Week 12 (p = 0.025). Patients in the combination
product group had a significantly greater probability of remaining in the study
without being withdrawn because of worsening asthma than did patients in the
placebo, salmeterol, or FP groups (p = 0.002). The combination product
significantly increased (p < 0. 001) morning PEF at endpoint (53.5 L/min) as
compared with placebo (-14 L/min), salmeterol (-11.6 L/min), or FP (15.2 L/min).
The combination product significantly (p = 0.011) reduced asthma symptom scores
and supplemental albuterol use, and significantly increased the percentage of
nights with no awakenings as compared with placebo, salmeterol, and FP (p =
0.016). Combination treatment with salmeterol 50 microg and FP 250 microg given
twice daily from the Diskus device provided better asthma control and greater
improvement in pulmonary function than did the individual agents, and may
simplify the management of asthma in patients who need both classes of drugs for
optimal control of their disease.
PMID- 10673197
TI - Accumulation of macrophages with dendritic cell characteristics in the pulmonary
response to Listeria.
AB - Pulmonary immunity reflects a balance between proinflammatory and
immunosuppressive factors in the lung. To determine the immune activities of
exudate macrophages in the pulmonary immune response, Lewis rats were injected
intratracheally with heat-killed Listeria (HKL), labeled ex vivo with the
lipophilic dye PKH-26. At 24 h, macrophages from bronchoalveolar lavage fluid
were purified on the basis of their surface membrane expression of RMA, a
macrophage-specific antigen, which is brightly expressed by resident alveolar
macrophages but dimly expressed by monocytes. Pulmonary macrophages were analyzed
for uptake of PKH-26-HKL, and RMA(bright/dim) macrophages sorted by FACS were
compared for cytokine expression, nitric oxide (NO) release, and APC activities.
RMA(bright) macrophages were OX-62(-), B7(-), and factor XIIIa(-); they were the
dominant mediators of phagocytosis when low doses of HKL were administered
intratracheally but did not support the proliferation of T lymphocytes. RMA(dim)
exudate macrophages were OX-62(+), B7(+), and factor XIIIa(+). They expressed
more IL-1 and TNF, but less nitric oxide, than did RMA(bright) macrophages; they
were excellent APCs for T cell responses. We conclude that a subset of RMA(dim)
exudate macrophages shows phenotypic and functional evidence of dendritic cell
differentiation.
PMID- 10673198
TI - Toluene diisocyanate enhances substance P in sensory neurons innervating the
nasal mucosa.
AB - Inhalation of irritants, such as toluene diisocyanate (TDI), stimulates substance
P (SP) release from peripheral processes of sensory neurons innervating the
airways. The purpose of this study was to determine if TDI inhalation affects
intraneuronal levels of SP and preprotachykinin (PPT) messenger RNA (mRNA) in the
sensory neurons of the trigeminal ganglion (TG) which innervate the nasal
epithelium. The nasal cavity of Fisher-344 rats was instilled with rhodamine
labeled latex microspheres. Ten days later, the rats were exposed to 60 ppb of
2,4-2,6-TDI vapor for 2 h. The TG were removed 1, 12, 24, 48, 72, and 96 h after
TDI treatment and prepared for SP immunocytochemistry and PPT in situ
hybridization. SP nerve fiber density in nasal epithelium was significantly
increased 12, 24, and 48 h after TDI exposure. The proportion of microsphere
labeled cell bodies expressing high levels of SP immunoreactivity was decreased
at 24 h but was increased above controls at 48 and 72 h. The proportion of
microsphere-labeled cell bodies expressing high levels of PPT mRNA was increased
above control levels at 24 and 48 h. The percentage of leukocytes observed in
nasal lavage fluid was significantly increased 12, 24, 48, and 72 h after
inhalation. These studies indicate that SP production in TG neurons projecting to
the nasal epithelium is transiently increased after TDI exposure, suggesting that
TDI inhalation not only causes SP release but also increased intraneuronal
neuropeptide levels. Increased neuronal SP levels may be involved in maintaining
neurogenic inflammation or the development of airway hyperresponsiveness.
PMID- 10673199
TI - Acute exposure to diesel exhaust increases IL-8 and GRO-alpha production in
healthy human airways.
AB - We have previously demonstrated that short-term exposure to diesel exhaust (DE)
for 1 h induced a marked leukocytic infiltration in the airways of healthy human
volunteers involving neutrophils, lymphocytes, and mast cells along with
increases in several inflammatory mediators. We hypothesized that the leukocyte
infiltration and the various inflammatory responses induced by DE were mediated
by enhanced chemokine and cytokine production by resident cells of the airway
tissue and lumen. To investigate this, 15 healthy human volunteers were exposed
to diluted DE and air on two separate occasions for 1 h each in an exposure
chamber. Fiberoptic bronchoscopy was performed 6 h after each exposure to obtain
endobronchial biopsies and bronchial wash (BW) cells. Using reverse
transcriptase/polymerase chain reaction enzyme-linked immunosorbent assay (RT-PCR
ELISA), a novel and sensitive technique to quantify relative amounts of cytokine
mRNA gene transcripts, and immunohistochemical staining with computer-assisted
image analysis to quantify expression of cytokine protein in the bronchial
tissue, we have demonstrated that DE enhanced gene transcription of interleukin-8
(IL-8) in the bronchial tissue and BW cells along with increases in IL-8 and
growth-regulated oncogene-alpha (GRO-alpha) protein expression in the bronchial
epithelium, and an accompanying trend toward an increase in IL-5 mRNA gene
transcripts in the bronchial tissue. There were no significant changes in the
gene transcript levels of interleukin-1B (IL-1beta), tumor necrosis factor-alpha
(TNF-alpha), interferon gamma (IFN-gamma), and granulocyte macrophage colony
stimulating factor (GM-CSF) either in the bronchial tissue or BW cells after DE
exposure at this time point. These observations suggest an underlying mechanism
for DE-induced airway leukocyte infiltration and offer a possible explanation for
the association observed between ambient levels of particulate matter and various
respiratory health outcome indices noted in epidemiological studies.
PMID- 10673200
TI - Lymphocytes migrate from the blood into the bronchoalveolar lavage and lung
parenchyma in the asthma model of the brown Norway rat.
AB - Lymphocyte migration from the blood into the lung has been suggested as being
responsible for the increase of lymphocytes, in particular CD4 T cells, in the
bronchoalveolar lavage (BAL) and bronchial mucosa in human asthma, but so far
there has been no direct proof. We studied lymphocyte immigration and lymphocyte
subpopulations in three lung compartments in ovalbumin (OVA)-sensitized and
challenged brown Norway (BN) rats. Increased numbers of CD4 and interleukin 2 (IL
2) receptor-positive T cells were found in the BAL and lung parenchyma in treated
animals, but also increased numbers of CD8 T cells, B cells, and natural killer
(NK) cells. For direct proof of lymphocyte migration from the blood into the
lung, leukocytes were labeled with a fluorescent dye, 5- (and 6-)
carboxyfluorescein-diacetate-succinimidyl-ester (CFSE), and injected
intravenously immediately prior to OVA aerosol challenge. One day after challenge
the number of CFSE(+), i.e., newly immigrated lymphocytes, was determined by flow
cytometry gated on the lymphocyte cluster. A 15 times (1.5 times) higher number
of CFSE(+) lymphocytes was found in the BAL (the lung parenchyma) of treated
animals in comparison with control rats. In the BAL 51.8% of CFSE(+) cells were
CD4-positive (parenchyma 72.7%) and 29.4% IL-2 receptor-positive (parenchyma
34.2%). There was no difference whether the leukocytes for labeling and injection
were obtained from untreated or from OVA-sensitized donor animals. Our data show
that lymphocyte immigration is at least in part responsible for the increase in
lymphocyte numbers in the BAL and lung parenchyma in this animal asthma model.
PMID- 10673201
TI - Aldosterone regulates Na,K-ATPase and increases lung edema clearance in rats.
AB - Aldosterone increases the Na,K-ATPase function in renal cells involved in active
Na(+) transport. Because the alveolar type 2 (AT2) cells participate in active
Na(+) transport, we studied whether aldosterone regulates the Na,K-ATPase in rat
AT2 cells and whether aldosterone delivered by aerosols to spontaneously
breathing rats affects edema clearance in a model of isolated-perfused lungs. The
AT2 cells treated with aldosterone had increased Na,K-ATPase beta1-subunit mRNA
and protein, which was associated with a 4-fold increase in the Na,K-ATPase
hydrolytic activity and the ouabain-sensitive (86)Rb(+) uptake. In physiologic
experiments, 24 h after aldosterone was delivered by aerosols to the rat air
spaces, the active Na(+) transport and lung edema clearance increased by
approximately 53% as compared with control rats and rats in which saline aerosols
were delivered. The data suggest that increased active Na(+) transport and lung
edema clearance induced by aldosterone is probably due to Na,K-ATPase regulation
in alveolar epithelial cells. Conceivably, aldosterone may be used as a strategy
to increase lung edema clearance.
PMID- 10673202
TI - An analysis algorithm for measuring airway lumen and wall areas from high
resolution computed tomographic data.
AB - High-resolution computed tomography (HRCT) has been used to examine airway
narrowing. We developed an automated computed tomographic image analysis
algorithm (computed tomographic airway morphometry; CTAM) to measure airway lumen
area (Ai ), airway wall area (Awa), and airway angle of orientation. Tubes of
varying size were embedded in Styrofoam and then scanned at angles between 0
degrees and 50 degrees to assess the accuracy of measurements made with CTAM. Two
excised pig lungs were fixed in inflation, sectioned, and scanned. Ai and Awa
were measured planimetrically from the cut surfaces to optimize CTAM measurement
parameters. In CTAM, Ai was defined according to an airway-size-dependent
threshold value, and total Awa was determined through a score-guided erosion
method. Results were compared with measurements made through a previously
validated method (manual method). CTAM provided accurate measurements of the
tubes' Ai values at all angles; Awa was overestimated in direct relation to
airway size. The manual method underestimated Ai and overestimated Awa in a
manner directly related to airway size as well as to airway angle of orientation.
In the excised lung, the mean errors of Ai and Awa measurements made with CTAM
were 0.52 +/- 0.24 mm(2) and 0.17 +/- 0.32 mm(2) (mean +/- SEM), respectively. Ai
errors with the manual method were similar, but Awa was overestimated to a
greater degree (6.3 +/- 0.38 mm(2); p < 0.01) and the error was proportional to
Awa (r = 0.64; p < 0.01). CTAM allows accurate measurements of airway dimensions
and angle of orientation.
PMID- 10673203
TI - Prevention of rabbit acute lung injury by surfactant, inhaled nitric oxide, and
pressure support ventilation.
AB - Improvement of pulmonary perfusion and blood oxygenation and prevention of acute
lung injury (ALI) may rely on ventilation strategy. We hypothesized that
application of a combined surfactant, inhaled nitric oxide (iNO), and pressure
support ventilation (PSV) should more effectively protect the lungs from injury.
Anesthetized and intubated adult rabbits weighing 2.8 +/- 0.3 kg were allowed to
breathe room air while receiving oleic acid intravenously (60 microl/kg). Within
90 min this caused a reduction of Pa(O(2)) from 94 +/- 7 to 48 +/- 3 mm Hg and
dynamic lung compliance (Cdyn) from 1.59 +/- 0.22 to 0.85 +/- 0.10 ml/cm H(2)O/kg
(both p < 0.01), and increase of intrapulmonary shunting (Q S/Q T) from 9.4 +/-
1.2 to 27 +/- 5% (p < 0.05). PSV was subsequently applied with 3 cm H(2)O of
continuous positive airway pressure and FI(O(2)) of 0.3, and the animals were
randomly allocated to four groups, receiving: (1) PSV only (Control, n = 10); (2)
iNO at 20 ppm (NO, n = 9); (3) surfactant phospholipids at 100 mg/kg (Surf, n =
8); and (4) surfactant at 100 mg/kg and iNO at 20 ppm (SNO, n = 8). PSV level was
varied to maintain a tidal volume of 8 to 10 ml/kg for another 12 h or until
early animal death. Five animals in the SNO, three each in the NO and Surf group,
and one in the Control group survived 12 h (SNO versus Control, p < 0.05). The
NO, Surf, and SNO groups had significantly improved mean Pa(O(2)) (> 70 mm Hg, p
< 0.05), and reduced Q S/Q T (15, 19, and 17%, respectively, p < 0.05) at 6 and
12 h, but not in the Control group. The SNO group had the highest values of Cdyn
at 12 h, alveolar aeration and disaturated phosphatidylcholine-to-total protein
ratio in bronchoalveolar lavage fluid, and the lowest wet-to-dry lung weight
ratio and lung injury score (p < 0.05). The results indicate that early
alleviation of ALI by surfactant, iNO, and PSV is due to synergistic effects, and
only PSV in this model had limited effects.
PMID- 10673204
TI - Natural autoantibody to MUC1 is a prognostic indicator for non-small cell lung
cancer.
AB - A great deal of attention has been focused on the antitumor effects of anti-MUC1
humoral and cellular responses. We examined whether anti-MUC1 antibody is present
in patients with lung cancer, and evaluated its prognostic value. Serum was
obtained from 30 patients with nonresectable, non-small cell lung cancer (NSCLC)
and 60 healthy volunteers. The presence of anti-MUC1 antibody was determined by
enzyme-linked immunosorbent assay. The patients were observed for a median follow
up time of 54.0 mo. Overall survival was estimated by the Kaplan-Meier method.
Multivariate analyses were performed using the Cox proportional hazards
regression model. Anti-KL-6/MUC1 antibody levels of the patients were
significantly lower than those of normal individuals (p < 0.001). One-year
survival rate of patients with high concentrations of anti-KL-6/MUC1 antibody was
significantly higher than that of patients with low levels of anti-KL-6/MUC1
antibody (90.9% versus 21.1%, p < 0.001). Anti-KL-6/MUC1 antibody status was most
strongly correlated with mortality, followed by lymph node status and albumin
levels, whereas sex, serum lactate dehydrogenase (LDH), and carcinoembryonic
antigen (CEA) levels, and metastasis status did not correlate with mortality.
These preliminary results indicate that the degree of decrease in antibody level
may be associated with a patient's prognosis.
PMID- 10673205
TI - Talc induces apoptosis in human malignant mesothelioma cells in vitro.
AB - Pleurodesis with talc is an accepted method for the treatment of symptomatic
pleural effusions secondary to mesotheliomas. Patients with mesothelioma who have
talc-induced pleurodesis have a lower morbidity than do those who do not have
pleurodesis. The mechanisms whereby talc mediated these effects were considered
to be secondary to a decrease or absence of a pleural effusion. The possibility
that talc may directly affect malignant cells was not considered. The present
study was designed to evaluate if talc directly effects cell death of malignant
mesothelioma cells (MMC) or normal pleural mesothelial cells (PMC). Three
confluent MMC and PMC were exposed to talc for 24, 48, and 72 h. In parallel
experiments, glass beads similar in size to talc were included as control.
Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated
deoxyuridine triphosphate nick end labeling (TUNEL) and DNA electrophoresis. Our
results demonstrated that talc at a therapeutically achievable concentration (6
microg/cm(2)) induces significant apoptosis in MMC. Talc-induced maximum
apoptosis in MMC (39.50 +/- 2.55%, 31.87 +/- 4.69%, and 15.10 +/- 3.93% in CRL
2081, CRL-5820, and CRL-5915, respectively) at 48 h, which was significantly (p <
0.05) greater than that in control cells. Electrophoresis of DNA isolated from
talc-exposed MMC demonstrated the typical ladder pattern of internucleosomal DNA
cleavage. Talc did not induce apoptosis in PMC, and glass beads did not cause
significant apoptosis in either MMC or PMC. The present study has demonstrated
that talc induces apoptosis in MMC without affecting normal mesothelial cells of
the pleura.
PMID- 10673206
TI - The utility of transbronchial needle aspiration in the staging of bronchogenic
carcinoma.
AB - We conducted a prospective multi-institutional clinical study involving community
hospitals and academic medical centers to more carefully define the value of
computerized tomography (CT) of the chest with transbronchial needle aspiration
(TBNA) in the staging of bronchogenic carcinoma (CA), and to assess the
predictors of a positive aspirate. Of 360 individuals determined to have
bronchogenic carcinoma, 50 of 81 (62%) with small cell carcinoma (SCC) and 135 of
279 (48%) with non-small cell carcinoma (NSCC) had positive aspirates (p =
0.034). TBNA precluded additional thoracic surgery in a total of 104 of 360 (29%)
patients and was exclusively diagnostic of carcinoma in 65 of 360 (18%) cases.
Right-sided tumors were more likely to have a positive mediastinal TBNA (p =
0.002 to 0. 01) as were histologic (67 of 118 [57%]) rather than cytology
aspirates (228 of 532 [41%]) (p < 0.001). Sensitivity was > 57% in lymph nodes
(LN) >/= 10 mm, and among LN of equivalent size, right paratracheal and
subcarinal sites were most likely to establish malignancy. Preoperative CT is a
valuable adjunct in the staging of CA by TBNA. Increasing LN size, right-sided
tumors, right paratracheal and subcarinal locations, use of a histology needle,
and the presence of SCC are the best predictors of a positive aspirate.
PMID- 10673207
TI - Deficiency of lamellar bodies in alveolar type II cells associated with fatal
respiratory disease in a full-term infant.
AB - We report a case of a full-term female infant who presented with severe
respiratory distress shortly after birth and died at 23 d of age with unremitting
respiratory failure. Infectious and other known causes of respiratory disease in
this clinical setting were excluded. Examination of a lung biopsy showed abnormal
lung parenchyma with features reminiscent of desquamative interstitial
pneumonitis. Ultrastructural studies revealed that alveolar type II cells lacked
cytoplasmic lamellar bodies, while other organelles appeared normal.
Histochemical and immunohistochemical investigations indicated normal alveolar
type II cell marker expression including surfactant proteins (SP-A, SP-B, pro-SP
B, and pro-SP-C). Mutations in the coding sequences of the SP-B gene were
excluded as a cause of disease. This case appears to be a novel congenital defect
affecting the pulmonary surfactant system. The cellular abnormality may involve
the assembly of cytoplasmic lamellar bodies in alveolar type II cells-the
principal storage site of pulmonary surfactant.
PMID- 10673208
TI - Manganese superoxide dismutase and catalase are coordinately expressed in the
alveolar region in chronic interstitial pneumonias and granulomatous diseases of
the lung.
AB - Free radicals have been suggested to play an important role in the pathogenesis
of interstitial lung diseases, the most important of which are chronic
interstitial pneumonias such as usual interstitial pneumonia (UIP) and
desquamative interstitial pneumonia (DIP) and granulomatous lung diseases such as
sarcoidosis. Because manganese superoxide dismutase (MnSOD) and catalase are two
important intracellular antioxidant enzymes that probably play a central role in
lung defense, the localization and intensity of these two enzymes were assessed
by immunohistochemistry in biopsies of UIP (n = 9), DIP (n = 11), pulmonary
sarcoidosis (n = 14), and extrinsic allergic alveolitis (n = 6). The mRNA of
these enzymes in selected samples of bronchoalveolar lavage was assessed by
Northern blotting. Catalase, but not MnSOD, was constitutively expressed,
especially in type II pneumocytes of the healthy lung of nonsmoking individuals.
In contrast, manganese SOD immunoreactivity was markedly upregulated in all of
the interstitial lung diseases investigated, whereas no increased expression of
catalase could be detected in any case. Both enzymes were expressed, especially
in type II pneumocytes and alveolar macrophages of DIP and UIP, in the well
preserved areas of the lung, in the acute fibromyxoid lesions of UIP, and in the
granulomas of sarcoidosis and extrinsic allergic alveolitis. The simultaneous
expression of MnSOD and catalase in the alveolar region suggests their protective
role against the progression of lung disease.
PMID- 10673209
TI - Prolonged allergen exposure induces structural airway changes in sensitized rats.
AB - The pathogenesis and functional consequences of airway remodeling in asthma
remain to be fully established. In the present study we evaluated the effect of
prolonged allergen exposure on airway function and structure in rats. Sensitized
Brown Norway rats were repeatedly exposed for periods of 2, 4, or 12 wk to
aerosolized ovalbumin (OA) or phosphate-buffered saline (PBS). OA exposure
induced a persistent increase in OA-specific serum IgE and in the number of
peribronchial eosinophils. After 2 wk of OA exposure, airway histology revealed
goblet-cell hyperplasia, an increase in bromodeoxyuridine-positive cells in
airway epithelium, increased fibronectin deposition, and a thickening of the
airway inner wall area. This coincided with airway hyperresponsiveness (AHR) to
aerosolized carbachol. After OA exposure for 12 wk, increased fibronectin (p <
0.05 versus PBS) and collagen deposition (p < 0.05 versus PBS) were observed in
the submucosa. After 12 wk of exposure, neither total nor inner wall area or
airway responsiveness to carbachol were any longer significantly different from
those of PBS-exposed animals. In conclusion, prolonged OA exposure in rats
induces structural airway changes that bear similarities to airway remodeling in
asthma. The study data further indicate that depending on the extent and
distribution of remodeling, changes in the extracellular matrix can enhance or
protect against AHR.
PMID- 10673210
TI - Prostaglandin H synthase 2 expression in airway cells from patients with asthma
and chronic obstructive pulmonary disease.
AB - Products of the prostaglandin H synthase (PGHS) metabolic pathway are thought to
play a role in the pathogenesis of asthma. We determined the level of expression
of the constitutive (PGHS-1) and inducible (PGHS-2) isoforms of the enzyme in
induced sputum and bronchial biopsies of patients with asthma, patients with
chronic obstructive pulmonary disease (COPD), and unaffected control subjects by
immunocyto- and immunohistochemistry. Immunoreactivity for PGHS-2 was
significantly greater in the induced sputum of patients with asthma and patients
with COPD compared with unaffected control subjects. The level of PGHS-2 was
greater in asthma than in COPD. Immunoreactivity for PGHS-1 increased in cells in
the induced sputum of patients with asthma and patients with COPD compared with
that of unaffected control subjects. Immunostained cells included macrophages,
eosinophils, and neutrophils. Greater PGHS-2 immunoreactivity was seen in the
submucosal inflammatory infiltrate and in the airway epithelium of patients with
asthma compared with unaffected control subjects. In summary, we demonstrate an
induction of PGHS-2 in asthma, suggesting increased formation of prostanoids,
which may contribute to the inflammatory process.
PMID- 10673211
TI - Mycobacterium abscessus infection in cystic fibrosis. Colonization or infection?
AB - We present a case of a patient with cystic fibrosis who was thought to be
colonized with Mycobacterium abscessus for 13 yr prior to developing clinically
apparent mycobacterial infection. However, histologic evidence indicated that
invasive mycobacterial disease was present from the onset. While accepting that
chronic endobronchial colonization with atypical mycobacteria may occur in
patients with cystic fibrosis, the repeated isolation of mycobacteria from the
sputum of these patients should alert the clinician to the possibility of
indolent disease. Early consideration of treatment for this infection should
occur in any patient with cystic fibrosis in whom there is an unexplained
deterioration in lung function. The recent introduction of high dose ibuprofen
raises concerns about its possible contribution to the progression of the
infection.
PMID- 10673212
TI - American Thoracic Society. Idiopathic pulmonary fibrosis: diagnosis and
treatment. International consensus statement. American Thoracic Society (ATS),
and the European Respiratory Society (ERS).
PMID- 10673213
TI - American Thoracic Society. What constitutes an adverse health effect of air
pollution? Official statement of the American Thoracic Society.
PMID- 10673214
TI - Relationship between resting hypercapnia and physiologic parameters before and
after lung volume reduction surgery in severe chronic obstructive pulmonary
disease.
PMID- 10673215
TI - Nocturnal oxygenation and prognosis in Duchenne muscular dystrophy.
PMID- 10673216
TI - Leukotrienes as targets for treatment of asthma and other diseases. Current basic
and clinical research
PMID- 10673217
TI - The discovery of the leukotrienes.
PMID- 10673218
TI - From bench to bedside. The hurdles of discovering a new leukotriene receptor
antagonist.
PMID- 10673219
TI - The molecular biology and regulation of 5-lipoxygenase.
PMID- 10673220
TI - Leukotriene C4 synthase. A pivotal enzyme in the biosynthesis of the cysteinyl
leukotrienes.
PMID- 10673221
TI - Membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG). A
widespread protein superfamily.
AB - The members of the MAPEG superfamily have been aligned and found to be distantly
related, with a common pattern of hydropathy. Figure 2A shows the multiple
sequence alignments of the human members and Figure 2B the corresponding
superimposed hydropathy profiles. The alignment in Figure 2A demonstrates a total
of six strictly conserved residues. The Arg-51 in LTC4 synthase has been
suggested to function as proton donor for the opening of the LTA4 epoxide. This
arginine is found in all but the FLAP sequences in accordance with the
observation that FLAP has no known enzyme activity. Also the Tyr-93 in LTC4
synthase has been suggested to function as a base for the formation of the
thiolate anion of glutathione. This tyrosine is not conserved in MGST1 or MGST1
L1. Table 1 summarizes some other properties of the individual human proteins.
They are all of the same size, ranging from 147 to 161 amino acids. Only FLAP
differs in that its isoelectric point is more neutral than that of the other,
more basic proteins. The genes encoding these proteins all reside on different
chromosomes (when known) (Table 1). In addition to the human proteins, MAPEG
members have been identified in plants, fungi, and bacteria. It is clearly a
challenge to elucidate their role in these different phyla in relation to their
defined physiological functions in humans.
PMID- 10673222
TI - Structure, function, and regulation of leukotriene A4 hydrolase.
PMID- 10673223
TI - Phospholipase A2 in eicosanoid generation.
PMID- 10673224
TI - Intracellular compartmentalization of leukotriene biosynthesis.
PMID- 10673225
TI - Pharmacological characterization of leukotriene receptors.
PMID- 10673226
TI - Binding to cysteinyl-leukotriene receptors.
PMID- 10673227
TI - Leukotriene B4 receptor. Cloning and intracellular signaling.
PMID- 10673228
TI - Cloning of a novel chemoattractant receptor activated by leukotriene B4 and used
by human immunodeficiency virus type 1 to infect CD4-positive immune cells. A
therapeutic connection to asthma?
PMID- 10673230
TI - Leukotriene bronchoconstriction induced by allergen and exercise.
PMID- 10673229
TI - The role of leukotrienes in the regulation of tone and responsiveness in isolated
human airways.
AB - Cysteinyl-leukotrienes and histamine are the major determinants of inherent tone
in isolated human bronchi, which is mainly the result of a balance of continual
production and release of contractile mediator, in particular cysteinyl
leukotrienes and to a lesser extent histamine, and on the other side
bronchodilating prostanoids. Cysteinyl-leukotrienes are also powerful
constrictors of isolated human airways through direct interaction with Cys-LT1
receptors on airway smooth muscle, and with a potency 1,000-fold higher than
histamine. On stimulation inflammatory cells such as eosinophils and mst cells
produce and release significantly increased amounts of leukotrienes leading to
smooth muscle contration in vitro. In isolated human airways, leukotrienes are
the most important mediators of allergen and adenosine-induced contractile
responses. The induction of allergen responses in passively sensitized airways is
not only related to an increased release of leukotrienes and histamines, but also
to an enhanced responsiveness of the airway smooth muscle, particularly to LTC4.
Studies in isolated human airways in vitro have demonstrated that understanding
the regulation of human airway tone and airway reactivity are closely linked to
the understanding of baseline and stimulated production of and smooth muscle
responsiveness to leukotrienes in vitro and in vivo.
PMID- 10673231
TI - Effects of antileukotrienes in the treatment of asthma.
PMID- 10673232
TI - Genetic variations in the 5-lipoxygenase core promoter. Description and
functional implications.
PMID- 10673233
TI - The metabolism of leukotriene B4 in Lewis lung carcinoma porcine kidney cells.
PMID- 10673234
TI - Adenosine, a potent natural suppressor of arachidonic acid release and
leukotriene biosynthesis in human neutrophils.
PMID- 10673235
TI - Formation of endogenous "antiinflammatory" lipid mediators by transcellular
biosynthesis. Lipoxins and aspirin-triggered lipoxins inhibit neutrophil
recruitment and vascular permeability.
PMID- 10673236
TI - Measurement of leukotrienes in humans.
PMID- 10673237
TI - Functional studies of leukotriene receptors in vascular tissues.
AB - The paradoxical effects of cysteinyl-leukotrienes, namely contraction and
relaxation, are now well documented in a number of vascular preparations from
various species. The vascular smooth muscle contractions are associated with
activation of a single receptor subtype and in some vascular smooth muscles with
activation of two receptor subtypes. However, the receptors implicated in the
contraction of vessels such as pig pulmonary arteries and veins, dog inferior
vena cava, and dog splenic and mesenteric veins remain to be established. There
are sufficient data concerning some vascular tissues to suggest that relaxations
induced by cysteinyl-leukotrienes are via the stimulation of specific receptors
present on the endothelium. The endothelium in human pulmonary arteries has one
receptor (CysLT2) and activation induced the release of NO. However, in isolated
human pulmonary veins two receptors are present, CysLT1 and CysLT2 (Figure 1).
Activation of the former induced the release of a contractile factor whereas
activation of the CysLT2 receptor released NO. In guinea pig pulmonary artery and
guinea pig thoracic aorta, one receptor has been demonstrated since the
relaxations are blocked by ICI-198615. These data suggest the presence of a
CysLT1 receptor. Activation of this receptor leads to the release of a relaxant
factor, namely, nitric oxide. In contrast, in human pulmonary arteries and veins
activation of a receptor that is resistant to ICI-198615 is associated with NO
release. These results suggest that there may be species differences even when
analogous vascular preparations are examined. While the cysteinyl-leukotrienes
are known to relax vascular smooth muscle in a variety of preparations from
different species, there are presently two pathways known to be involved in this
response. One involves the metabolites of arachidonic acid via the cyclooxygenase
enzymatic pathway and the other implicates products of the L-arginine enzymatic
pathway. Although both pathways may be present and active in the endothelium of
the vascular preparations only one of these enzymatic pathways may be dominant
and responsible for the relaxations observed. Ortiz and coworkers have
demonstrated that in pulmonary veins the dominant pathway for cysteinyl
leukotriene relaxations is the NO pathway. There are some reports from animal
studies that support a dominant role for NO in pulmonary veins. In contrast,
Allen and co-workers demonstrated that the LTC4-induced relaxations in isolated
human saphenous veins were not modified by treatment of tissues with an NO
inhibitor but were significantly enhanced after treatment with indomethacin.
These authors suggested that a contracting factor derived from the arachidonic
acid pathway was released in preparations challenged with LTC4. In addition,
these investigators demonstrated that the NO inhibitor had no effect on the LTC4
relaxations. Together, these results suggest that cysteinyl-leukotriene effects
in human pulmonary veins are dominated by the NO pathway whereas in human
systemic veins these mediator effects are modified by metabolites of the
cyclooxygenase pathway. Unfortunately, most studies involving the actions of
cysteinyl-leukotrienes on vessels have been performed in the presence of
indomethacin, making interpretation of the relative contribution of the
cyclooxygenase and NO pathways difficult. In any event, the cysteinyl
leukotrienes may have a prominent role in the activation of these pathways and
the receptors involved have not been clearly established.
PMID- 10673238
TI - Leukotrienes in cardiovascular diseases.
PMID- 10673239
TI - Interactions between leukotrienes and other inflammatory mediators/modulators in
the microvasculature.
PMID- 10673240
TI - 5-Lipoxygenase and leukotrienes. Transgenic mouse and nuclear targeting studies.
PMID- 10673241
TI - Role of leukotrienes in bronchial hyperresponsiveness and cellular responses in
airways.
PMID- 10673242
TI - Leukotrienes in rhinitis.
PMID- 10673243
TI - Treatment of aspirin-intolerant asthma with antileukotrienes.
PMID- 10673244
TI - Genetic mechanisms in aspirin-induced asthma.
PMID- 10673246
TI - Circulation online only : february 15, 2000
PMID- 10673245
TI - Antileukotriene therapy. Future directions.
PMID- 10673247
TI - Serial in vivo MRI documents arterial remodeling in experimental atherosclerosis.
AB - BACKGROUND: Arterial remodeling in response to atherosclerosis may be outward
(positive) or inward (negative) and is an important mechanism in the clinical
manifestations of atherosclerosis and restenosis after percutaneous coronary
interventions. Postmortem and intravascular ultrasound studies of arterial
remodeling do not allow serial and noninvasive data to be obtained. In a rabbit
model of atherosclerosis, we sought to validate MRI as a new tool for
documentation of arterial remodeling. METHODS AND RESULTS: Watanabe heritable
hyperlipidemic rabbits underwent serial MRI at baseline and 6 months after aortic
balloon denudation. The lumen area had a small but significant (P=0.006)
increase, from 4.36+/-0.16 to 4. 89+/-0.12 mm(2). There was a large, significant
(P<0.0001) increase in the outer wall area, from 7.96+/-0.19 to 10.46+/-0.19
mm(2). The vessel wall area (a marker of atherosclerotic burden) increased
significantly (P<0.0001), from 3.61+/-0.07 to 5.57+/-0.09 mm(2). Thus, the
increase in atherosclerotic burden over time was completely accounted for by
positive arterial remodeling. The subgroup used for histopathological validation
confirmed a significant (P<0.0001) agreement between histopathology and MRI for
assessment of all 3 parameters. CONCLUSIONS: MRI can provide serial and
noninvasive data about the arterial wall, allowing assessment of arterial
remodeling in this rabbit model. Thus, MRI appears to be a useful tool for the
investigation of arterial remodeling both in native atherosclerosis and after
percutaneous coronary intervention.
PMID- 10673248
TI - A randomized comparison of clopidogrel and aspirin versus ticlopidine and aspirin
after the placement of coronary-artery stents.
AB - BACKGROUND: The introduction of an effective antiplatelet therapy with aspirin
and ticlopidine after the placement of coronary-artery stents has decreased the
risk of thrombotic stent occlusions (TSO) and hemorrhagic complications. However,
the use of ticlopidine is limited by hematological and gastrointestinal adverse
effects. The safety and efficacy of clopidogrel after stenting remains to be
established. METHODS AND RESULTS: After successful coronary stenting during
elective or emergency percutaneous transluminal coronary angioplasty, 700
patients with 899 lesions were randomly assigned to receive a 4-week course of
either 500 mg ticlopidine (n=345) or 75 mg clopidogrel (n=355), in addition to
100 mg aspirin. All the following clinical events reflecting TSO were included in
the prespecified primary cardiac endpoint: cardiac death, urgent target vessel
revascularization, angiographically documented TSO, or nonfatal myocardial
infarction within 30 days. The primary noncardiac endpoint was defined as
noncardiac death, stroke, severe peripheral vascular or hemorrhagic events, or
any adverse event resulting in discontinuation of study medication. Cardiac
events occurred in 17 patients [11 (3.1%) with clopidogrel and 6 (1.7%) with
ticlopidine (P=0.24)]. The primary noncardiac endpoint was observed in 16
patients (4.5%) assigned to receive clopidogrel versus 33 patients (9.6%)
assigned to receive ticlopidine (P=0.01). CONCLUSIONS: After the placement of
coronary-artery stents in unselected patients, antiplatelet therapy with aspirin
and clopidogrel seems to be comparably safe and effective as aspirin and
ticlopidine. Noncardiac events were significantly reduced with clopidogrel.
PMID- 10673249
TI - Spironolactone increases nitric oxide bioactivity, improves endothelial
vasodilator dysfunction, and suppresses vascular angiotensin I/angiotensin II
conversion in patients with chronic heart failure.
AB - BACKGROUND: The RALES study showed that spironolactone, added to conventional
therapy for chronic heart failure, dramatically reduced mortality. We tested the
hypothesis that this benefit was partially due to improvement in endothelial
function and/or to amplified suppression of the vascular renin-angiotensin axis.
METHODS AND RESULTS: We performed a randomized, placebo-controlled, double-blind
crossover study on 10 patients with NYHA class II to III chronic heart failure on
standard diuretic/ACE inhibitor therapy, comparing 50 mg/d spironolactone (1
month) versus placebo. Forearm vasculature endothelial function was assessed by
bilateral forearm venous occlusion plethysmography using acetylcholine and N
monomethyl-L-arginine (L-NMMA), with sodium nitroprusside as a control
vasodilator. Also, vascular ACE activity was assessed by use of angiotensin (Ang)
I, with Ang II as a control vasoconstrictor. Spironolactone significantly
increased the forearm blood flow response to acetylcholine (percentage change in
forearm blood flow [mean+/-SEM], 177+/-29% versus 95+/-20%, spironolactone versus
placebo; P<0.001), with an associated increase in vasoconstriction due to L-NMMA
(-35+/-6% versus -18+/-4%; P<0.05). The Ang I response was also significantly
reduced with spironolactone (P<0.05), with Ang II responses unaltered.
CONCLUSIONS: Spironolactone improves endothelial dysfunction, increases NO
bioactivity, and inhibits vascular Ang I/Ang II conversion in patients with heart
failure, providing novel mechanisms for its beneficial effect on cardiovascular
mortality.
PMID- 10673250
TI - Extent and direction of arterial remodeling in stable versus unstable coronary
syndromes : an intravascular ultrasound study.
AB - BACKGROUND: The morphological characteristics of coronary plaques in patients
with stable versus unstable coronary syndromes have been described in vivo with
intravascular ultrasound, but the relationship between arterial remodeling and
clinical presentation is not well known. METHODS AND RESULTS: We studied 85
patients with unstable and 46 patients with stable coronary syndromes using
intravascular ultrasound before coronary intervention. The lesion site and a
proximal reference site were analyzed. The remodeling ratio (RR) was defined as
the ratio of the external elastic membrane (EEM) area at the lesion to that at
the proximal reference site. Positive remodeling was defined as an RR >1.05 and
negative remodeling as an RR <0.95. Plaque area (13.9+/-5.5 versus 11.1+/-4.8
mm(2); P=0.005), EEM area (16.1+/-6.2 versus 13.0+/-4.8 mm(2); P=0. 004), and the
RR (1.06+/-0.2 versus 0.94+/-0.2; P=0.008) were significantly greater at target
lesions in patients with unstable syndromes than in patients with stable
syndromes. Positive remodeling was more frequent in unstable than in stable
lesions (51. 8% versus 19.6%), whereas negative remodeling was more frequent in
stable lesions (56.5% versus 31.8%) (P=0.001). CONCLUSIONS: Positive remodeling
and larger plaque areas were associated with unstable clinical presentation,
whereas negative remodeling was more common in patients with stable clinical
presentation. This association between the extent of remodeling and clinical
presentation may reflect a greater tendency of plaques with positive remodeling
to cause unstable coronary syndromes.
PMID- 10673251
TI - Atherosclerotic plaque burden and CK-MB enzyme elevation after coronary
interventions : intravascular ultrasound study of 2256 patients.
AB - BACKGROUND: Elevation of serum creatine kinase MB fraction (CK-MB) after
percutaneous coronary interventions has been associated with early and late
mortality; however, the pathogenesis of CK-MB elevation is still unknown. We
hypothesized that CK-MB elevation was related to atherosclerotic plaque burden as
assessed by preintervention intravascular ultrasound (IVUS). METHODS AND RESULTS:
We studied 2256 consecutive patients who underwent intervention of 2780 native
coronary lesions and had complete high-quality preintervention IVUS imaging in
the era before routine use of platelet glycoprotein IIb/IIIa inhibitors. Patients
were divided into 3 groups: CK-MB within normal range (1675 patients; 2061
lesions); CK-MB elevation 1 to 5 times upper limit of normal (292 patients; 355
lesions); and CK-MB elevation > or = 5 times upper limit of normal (289 patients;
364 lesions). Qualitative angiographic lesion morphology and quantitative
analysis were similar among the 3 groups. On preintervention IVUS, progressively
more reference segment and lesion site plaque burden and lesion site calcium
occurred in the groups with CK-MB elevation. Positive remodeling was more common
in lesions with CK-MB elevation. As levels of CK-MB increased, cross-sectional
narrowing (percentage plaque burden) increased, both at the reference site (mean
cross-sectional narrowing values were 45.1%, <49.3%, and <52.2% for normal CK-MB,
1 to 5 times upper limit of normal, and > or =5 times upper limit of normal
groups, respectively; P=0.03) and at the lesion site (81.9%, <85.4%, and <87.1%,
respectively; P=0.04). Multivariate analysis indicated that de novo lesions,
atheroablative technique, plaque burden at the lesion and reference segments, and
final minimal lumen diameter were independent predictors of CK-MB elevation.
CONCLUSIONS: CK-MB elevation correlates with a greater atherosclerotic plaque
burden. CK-MB elevation after intervention may be a marker of diffuse
atherosclerotic disease or a consequence of catheter-based intervention in more
diseased arteries or both.
PMID- 10673252
TI - Diastolic blood pressure changes during exercise positively correlate with serum
cholesterol and insulin resistance.
AB - BACKGROUND: Metabolic factors, including plasma concentrations of cholesterol and
insulin resistance, may influence blood pressure through effects on vascular
reactivity. Such effects might influence blood pressure during exercise more
strongly than at rest. METHODS AND RESULTS: We examined whether there is an
association between serum cholesterol or insulin resistance and change in blood
pressure during mild exercise. Blood pressure was measured at rest and during
fixed low-workload bicycle ergometry (50, 75, and 100 W, each for 3 minutes) in
75 healthy active men (age, 18 to 66 years). Blood pressure at rest was not
significantly correlated with serum cholesterol or insulin resistance (estimated
from the fasting glucose-insulin product). The change from resting values in
diastolic but not systolic blood pressure during exercise was correlated with
serum cholesterol (R>0.47, P<0.0001 for each workload) and insulin resistance
(R>0.38, P<0.01 for each workload). Serum cholesterol and insulin resistance were
the only independent predictors of the change in diastolic blood pressure during
exercise in a stepwise regression model incorporating age, body mass index, serum
cholesterol, triglycerides, HDL cholesterol, insulin resistance, and heart rate
during exercise. In a further study, the change in diastolic blood pressure
during exercise was greater in men with uncomplicated type 2 diabetes (13.6 mm Hg
[95% CI, 8.5 to 18.8]; n=10) than in nondiabetic control men (2.7 mm Hg [95% CI,
2. 0 to 7.3]; n=10; P=0.002). CONCLUSIONS: Changes in diastolic blood pressure
during gentle exercise are strongly associated with serum concentrations of total
cholesterol and insulin resistance. This may contribute to development of
hypertensive complications in dyslipidemic and/or insulin-resistant patients.
PMID- 10673253
TI - Effectiveness and limitations of beta-blocker therapy in congenital long-QT
syndrome.
AB - BACKGROUND: beta-blockers are routinely prescribed in congenital long-QT syndrome
(LQTS), but the effectiveness and limitations of beta-blockers in this disorder
have not been evaluated. METHODS AND RESULTS: The study population comprised 869
LQTS patients treated with beta-blockers. Effectiveness of beta-blockers was
analyzed during matched periods before and after starting beta-blocker therapy,
and by survivorship methods to determine factors associated with cardiac events
while on prescribed beta-blockers. After initiation of beta-blockers, there was a
significant (P<0.001) reduction in the rate of cardiac events in probands (0.97+/
1.42 to 0.31+/-0.86 events per year) and in affected family members (0. 26+/-0.84
to 0.15+/-0.69 events per year) during 5-year matched periods. On-therapy
survivorship analyses revealed that patients with cardiac symptoms before beta
blockers (n=598) had a hazard ratio of 5.8 (95% CI, 3.7 to 9.1) for recurrent
cardiac events (syncope, aborted cardiac arrest, or death) during beta-blocker
therapy compared with asymptomatic patients; 32% of these symptomatic patients
will have another cardiac event within 5 years while on prescribed beta-blockers.
Patients with a history of aborted cardiac arrest before starting beta-blockers
(n=113) had a hazard ratio of 12.9 (95% CI, 4.7 to 35.5) for aborted cardiac
arrest or death while on prescribed beta-blockers compared with asymptomatic
patients; 14% of these patients will have another arrest (aborted or fatal)
within 5 years on beta-blockers. CONCLUSIONS: beta-blockers are associated with a
significant reduction in cardiac events in LQTS patients. However, syncope,
aborted cardiac arrest, and LQTS-related death continue to occur while patients
are on prescribed beta-blockers, particularly in those who were symptomatic
before starting this therapy.
PMID- 10673254
TI - Antiarrhythmic efficacy of dipyridamole in treatment of reperfusion arrhythmias :
evidence for cAMP-mediated triggered activity as a mechanism responsible for
reperfusion arrhythmias.
AB - BACKGROUND: Intracellular calcium overload is believed to play an important role
in development of reperfusion arrhythmias. Dipyridamole, an inhibitor of cellular
uptake of adenosine, may prevent or terminate reperfusion arrhythmias by reducing
intracellular calcium overload. METHODS AND RESULTS: First, we tested for a
preventive effect of dipyridamole. Sixty-one patients who underwent primary PTCA
for treatment of acute anterior wall myocardial infarction were enrolled in this
prospective study. Patients were divided into dipyridamole (DP) and
nondipyridamole (non-DP) groups. The 2 groups had similar baseline
characteristics. In the DP group, dipyridamole 0.5 mg/kg was infused
intravenously for 3 minutes immediately before reperfusion during primary PTCA.
Arrhythmias after reperfusion were analyzed from continuous ECG recordings. None
of the patients in the DP group (n=23) had accelerated idioventricular rhythms
(AIVR) or ventricular tachycardia (VT). In contrast, 7 (18.4%) had AIVR and 3
(7.9%) had VT in the non-DP group (n=38; P<0.01). Second, we tested for a
termination effect of dipyridamole. Dipyridamole 0.5 mg/kg was infused
intravenously while continuous ECG recordings were obtained in 9 patients who had
either sustained AIVR (n=7) or sustained VT (n=2) after reperfusion of occluded
coronary artery. Arrhythmias were terminated in all patients. CONCLUSIONS: These
results indicate that administration of dipyridamole can prevent and terminate
reperfusion arrhythmias such as AIVR and VT. cAMP-mediated triggered activity
may, at least in part, be responsible for reperfusion-induced AIVR and VT.
PMID- 10673255
TI - Dual-loop intra-atrial reentry in humans.
AB - BACKGROUND: Dual-loop atrial reentrant tachycardias have not been clinically
described. METHODS AND RESULTS: Five patients (3 men, 2 women; mean age, 48+/-16
years) were studied 24+/-15 years after surgical closure of an ostium secundum
atrial septal defect for drug-resistant atrial tachycardia. Complete tachycardia
mapping was performed in the right atrium with multipolar catheters and a 3
dimensional electroanatomic mapping system (Biosense), followed by linear
radiofrequency ablation of the narrowest part of each complete loop. Six
tachycardias with a typical flutter morphology, a cycle length of 262+/-40 ms,
and a superior f-wave axis (-77+/-11 degrees ) were mapped, 4 with a Biosense map
including 106+/-32 points. Five figure-8 tachycardias had a counterclockwise loop
around the tricuspid valve sharing a common anterior channel with a clockwise
loop around the lateral atriotomy scar. One tachycardia was thought to have 2
counterclockwise loops around the same obstacles. Radiofrequency delivery in the
cavotricuspid isthmus in each case transformed the tachycardia without any pause
in a different morphology tachycardia with an inferior P-wave axis (50+/-42
degrees ) and nearly the same cycle length (272+/-39 ms) but with the
periatriotomy loop alone. This arrhythmia required ablation of a second isthmus:
between the lower end of the atriotomy and the inferior vena cava in 4 and the
superior tricuspid annulus in 1. After a follow-up of 19+/-6 months, there were
no recurrences. CONCLUSIONS: Figure-8 double-loop tachycardias mimicking the ECG
pattern of a common atrial flutter occur in some patients after a surgical
atriotomy. Ablation of 1 loop produces a sudden transformation to a new reentrant
tachycardia formed of the remaining loop that requires ablation at a second
isthmus.
PMID- 10673256
TI - Analysis by early angiography of right internal thoracic artery grafting via the
transverse sinus : predictors of graft failure.
AB - BACKGROUND: There has been debate regarding whether technically demanding right
internal thoracic artery (RITA) grafting via the transverse sinus can be
extensively applied to patients in high-risk groups, such as patients with a
small body size, elderly patients, and woman with relatively smaller coronary
artery and internal thoracic artery (ITA) diameters. METHODS AND RESULTS: Of the
1456 patients who underwent isolated coronary artery bypass grafting between
January 1989 and December 1998 at Kumamoto Central Hospital, 393 patients (mean
age, 62.4+/-9.0 years) with the RITA anastomosed to the major branches of the
circumflex artery were studied. Left ITA grafting was performed in 384 patients,
and in 369, the in situ left ITA was anastomosed to the left anterior descending
coronary artery using standard methods. Early postoperative angiography was
performed in 381 patients. The RITA was occluded in 4 patients, and string-like
artery and significant stenosis were present in 11 and 7 patients, respectively;
RITA graft patency was thus 94.1%. Of the preoperative variables and angiographic
data, simple and multiple logistic regression analyses identified decreased
severity of native stenosis, diffuse sclerosis of native vessels, and residual
side branches of the ITA as independent predictors of nonfunctional grafts. The
method of ITA grafting did not influence the patency of the graft. CONCLUSIONS:
The excellent patency rate demonstrated by this study, the largest angiographic
study to date of RITA grafting via the transverse sinus, indicates that this
technique can provide reliable revascularization of the left ventricle and that
it has the potential to be applied to a wide variety of patients with diseased
circumflex arteries.
PMID- 10673257
TI - The anatomic basis of connections between the coronary sinus musculature and the
left atrium in humans.
AB - BACKGROUND: This study determined the histological features of the atrial
myocardium connecting the coronary sinus and the left atrium in humans. METHODS
AND RESULTS: Ten necropsied hearts were studied by performing serial longitudinal
sections parallel to the long axis of the coronary sinus that extended its full
length using a large microtome. In all specimens, the venous wall of the coronary
sinus was surrounded by a cuff of striated muscle extending 40+/-8 mm from the
ostium. Striated myocardial connections of varying number and morphology left
this coronary muscle cuff and connected to the left atrium; they ranged from 1 to
2 fascicles to a widely intermingled continuum (thickness, 2.79+/-2 mm; width,
2.91+/-3.5 mm). These connections originated 8.8+/-5.7 mm from the coronary sinus
ostium and inserted 18+/-11 mm distally into the left atrium. The insulating
compartment in which the connections traversed between the left atrium and the
coronary sinus was mostly formed of adipose tissue. The valve of Vieussens was
found in 6 hearts at a mean distance of 3.4+/-3.2 mm from the distal extremity of
the coronary sinus muscle cuff. CONCLUSIONS: In the human heart, a consistent but
morphologically variable left atrial coronary sinus myocardial connection was
found. This emphasizes the need for surgical dissection or catheter ablation in
or around the coronary sinus to eliminate these connections.
PMID- 10673258
TI - Bradycardia and the role of beta-blockade in the amelioration of left ventricular
dysfunction.
AB - BACKGROUND: It is clear that beta-blockers are effective for treatment of
congestive heart failure, but their mechanism of action remains controversial.
Hypothesized mechanisms include normalization of beta-receptor function and
myocardial protection from the effects of catecholamines, possibly by the
institution of bradycardia. We hypothesized that beta-blockade-induced
bradycardia was an important mechanism by which these agents were effective for
correction of LV dysfunction. METHODS AND RESULTS: In 2 groups of dogs with
mitral regurgitation and LV dysfunction, beta-blockers were instituted. In 1
group that received beta-blockers and pacing (group beta+P), a pacemaker
prevented the natural bradycardia that beta-blockers cause. In both groups,
substantial LV dysfunction developed. Before beta-blockade, the end-systolic
stiffness constant decreased from 3. 5+/-0.1 to 2.7+/-0.2 (P<0.01) at 3 months in
group beta+P. A similar reduction occurred in the group that eventually received
only beta-blockers (group betaB). In group betaB, end-systolic stiffness improved
after 3 months of beta-blockade from 2.9+/-0.2 to 3.5+/-0.4 and was not different
from baseline. However, in group beta+P, end-systolic stiffness failed to improve
(2.7+/-0.2) after 3 months of mitral regurgitation, and was 2.9+/-0.2 at the end
of the studies. The contractile function of cardiocytes isolated from the
ventricles at the end of the studies confirmed these in vivo estimates of
contractility. CONCLUSIONS: We conclude that institution of bradycardia is a
major mechanism by which beta-blockers are effective for restoration of
contractile function in a model of LV dysfunction.
PMID- 10673259
TI - Akt promotes survival of cardiomyocytes in vitro and protects against ischemia
reperfusion injury in mouse heart.
AB - BACKGROUND: IGF-1 has been shown to protect myocardium against death in animal
models of infarct and ischemia-reperfusion injury. In the present study, we
investigated the role of the IGF-1-regulated protein kinase Akt in cardiac
myocyte survival in vitro and in vivo. METHODS AND RESULTS: IGF-1 promoted
survival of cultured cardiomyocytes under conditions of serum deprivation in a
dose-dependent manner but had no effect on cardiac fibroblast survival. The
cytoprotective effect of IGF-1 on cardiomyocytes was abrogated by the
phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor wortmannin. Wortmannin had
no effect on cardiomyocyte viability in the absence of IGF-1. IGF-1-mediated
cytoprotection correlated with the wortmannin-sensitive induction of Akt protein
kinase activity. To examine the functional consequences of Akt activation in
cardiomyocyte survival, replication-defective adenoviral constructs expressing
wild-type, dominant-negative, and constitutively active Akt genes were
constructed. Transduction of dominant-negative Akt blocked IGF-1-induced survival
but had no effect on cardiomyocyte survival in the absence of IGF-1. In contrast,
transduction of wild-type Akt enhanced cardiomyocyte survival at subsaturating
levels of IGF-1, whereas constitutively active Akt protected cardiomyocytes from
apoptosis in the absence of IGF-1. After transduction into the mouse heart in
vivo, constitutively active Akt protected against myocyte apoptosis in response
to ischemia-reperfusion injury. CONCLUSIONS: These data are the first
documentation that Akt functions to promote cellular survival in vivo, and they
indicate that the activation of this pathway may be useful in promoting myocyte
survival in the diseased heart.
PMID- 10673260
TI - Microbubble persistence in the microcirculation during ischemia/reperfusion and
inflammation is caused by integrin- and complement-mediated adherence to
activated leukocytes.
AB - BACKGROUND: Albumin microbubbles that are used for contrast echocardiography
persist within the myocardial microcirculation after ischemia/reperfusion (I-R).
The mechanism responsible for this phenomenon is unknown. METHODS AND RESULTS:
Intravital microscopy of the microcirculation of exteriorized cremaster muscle
was performed in 12 wild-type mice during intravenous injections of fluorescein
labeled microbubbles composed of albumin, anionic lipids, or cationic lipids.
Injections were performed at baseline and after 30 to 90 minutes of I-R in 8 mice
and 2 hours after intrascrotal tumor necrosis factor-alpha (TNF-alpha) in 4 mice.
Microbubble adherence at baseline was uncommon (<2/50 high-power fields). After I
R, adherence increased (P<0.05) to 9+/-5 and 5+/-4 per 50 high-power fields for
albumin and anionic lipid microbubbles, respectively, due to their attachment to
leukocytes adherent to the venular endothelium. TNF-alpha produced even greater
microbubble binding, regardless of the microbubble shell composition. The degree
of microbubble attachment correlated (r=0.84 to 0.91) with the number of adhered
leukocytes. Flow cytometry revealed that microbubbles preferentially attached to
activated leukocytes. Albumin microbubble attachment was inhibited by blocking
the leukocyte beta(2)-integrin Mac-1, whereas lipid microbubble binding was
inhibited when incubations were performed in complement-depleted or heat
inactivated serum rather than control serum. CONCLUSIONS: Microvascular
attachment of albumin and lipid microbubbles in the setting of I-R and TNF-alpha
induced inflammation is due to their beta(2)-integrin- and complement-mediated
binding to activated leukocytes adherent to the venular wall. Thus, microbubble
persistence on contrast ultrasonography may be useful for the detection and
monitoring of leukocyte adhesion in inflammatory diseases.
PMID- 10673261
TI - Regulation of endothelial constitutive nitric oxide synthase gene expression in
endothelial cells and in vivo : a specific vascular action of insulin.
AB - BACKGROUND: The vasodilatory effect of insulin can be acute or increase with time
from 1 to 7 hours, suggesting that insulin may enhance the expression of
endothelial nitric oxide synthase (eNOS) in endothelial cells. The objective of
the present study was to characterize the extent and signaling pathways by which
insulin regulates the expression of eNOS in endothelial cells and vascular
tissues. METHODS AND RESULTS: Physiological concentrations of insulin (10(-10) to
10(-7) mmol/L) increased the levels of eNOS mRNA, protein, and activity by 2-fold
after 2 to 8 hours of incubation in cultured bovine aortic endothelial cells.
Insulin enhanced eNOS gene expression in microvessels isolated from Zucker lean
rats but not from insulin-resistant Zucker fatty rats. Inhibitors of
phosphatidylinositol-3 kinase (PI-3 kinase) decreased the effect of insulin on
eNOS gene expression, but a general protein kinase C (PKC) inhibitor, GF109203X
or PKCbeta isoform inhibitor, LY333531 enhanced eNOS expression. In contrast, PKC
activators inhibited both the activation by insulin of PI-3 kinase and eNOS mRNA
levels. Overexpression of PKCbeta isoform in endothelial cells inhibited the
stimulation by insulin of eNOS expression and PI-3 kinase activities in parallel.
CONCLUSIONS: Insulin can regulate the expression of eNOS gene, mediated by the
activation of PI-3 kinase, in endothelial cells and microvessels. Thus, insulin
may chronically modulate vascular tone. The activation of PKC in the vascular
tissues as in insulin resistance and diabetes may inhibit PI-3 kinase activity
and eNOS expression and may lead to endothelial dysfunctions in these
pathological states.
PMID- 10673263
TI - alpha-adrenergic coronary vasoconstriction and myocardial ischemia in humans.
AB - The use of quantitative coronary angiography, combined with Doppler and PET, has
recently been directed at the study of alpha-adrenergic coronary vasomotion in
humans. Confirming prior animal experiments, there is no evidence of alpha
adrenergic coronary constrictor tone at rest. Again confirming prior experiments,
responses to alpha-adrenoceptor activation are augmented in the presence of
coronary endothelial dysfunction and atherosclerosis, involving both alpha(1)-
and alpha(2)-adrenoceptors in epicardial conduit arteries and microvessels. Such
augmented alpha-adrenergic coronary constriction is observed during exercise and
coronary interventions, and it is powerful enough to induce myocardial ischemia
and limit myocardial function. Recent studies indicate a genetic determination of
alpha(2)-adrenergic coronary constriction.
PMID- 10673262
TI - Antisense inhibition of beta(1)-adrenergic receptor mRNA in a single dose
produces a profound and prolonged reduction in high blood pressure in
spontaneously hypertensive rats.
AB - BACKGROUND: beta-Blockers are the first line of therapy for hypertension.
However, they are associated with side effects because of central nervous system
(CNS) effects and beta(2)-adrenergic antagonism. To overcome these problems and
provide a long-term beta(1)-blockade, antisense oligonucleotides against rat
beta(1)-adrenergic receptor (beta(1)-AR) mRNA (beta(1)-AS-ODN) were designed and
tested for the ability to inhibit cardiac beta(1)-ARs as well as lower blood
pressure in spontaneously hypertensive rats (SHRs). METHODS AND RESULTS:
Radioligand binding assay showed that a single intravenous injection of beta(1)
AS-ODN delivered in cationic liposomes significantly decreased cardiac beta(1)-AR
density by 30% to 50% for 18 days (P<0.01), with no effect on beta(2)-ARs. This
was accompanied by marked attenuation of beta(1)-AR-mediated positive inotropic
response in isolated perfused hearts in vitro (P<0.02) and in conscious SHRs
monitored by telemetry in vivo (P<0.02). Furthermore, the blood pressure of SHRs
was reduced for 20 days, with a 38 mm Hg maximum drop. Heart rate was not
significantly decreased. Quantitative autoradiography was performed to assess
beta(1)-AS-ODN effects on the CNS, which demonstrated no changes in beta(1)-ARs
in brain, in contrast to a significant reduction in heart and kidney (P<0.05).
For comparison with beta-blockers, the effects of atenolol on cardiovascular
hemodynamics were examined, which lowered blood pressure for only 10 hours and
elicited appreciable bradycardia in SHRs. CONCLUSIONS: These results indicate
that beta(1)-AS-ODN, a novel approach to specific beta(1)-blockade, has
advantages over currently used beta-blockers in providing a profound and
prolonged reduction in blood pressure without affecting heart rate, beta(2)-ARs,
and the CNS. Diminished cardiac contractility resulting from less beta(1)-AR
expression contributes to the antihypertensive effect.
PMID- 10673264
TI - Images in cardiovascular medicine. Hemolysis after mitral valve repair.
PMID- 10673265
TI - Synthetic inhibitors of platelet glycoprotein IIb/IIIa in clinical development.
AB - Activation of the platelet glycoprotein (GP IIb/IIIa) receptor on the platelet
surface is the final pathway of platelet aggregation, regardless of the
initiating stimulus. Inhibitors of GP IIb/IIIa receptors include monoclonal
antibodies (abciximab) against this receptor and peptidic and nonpeptidic
synthetic specific receptor blockers. Abciximab exchanges between and binds to
platelets for as long as 2 weeks, whereas synthetic GP IIb/IIIa inhibitors
inhibit ex vivo platelet aggregation for only a few hours after the end of
infusion, but some have the advantage of also being orally active. In the
secondary prevention of atherothrombosis, large-scale trials were successfully
conducted with aspirin, dipyridamole, ticlopidine, and clopidogrel. In the first
large-scale trials with GP IIb/IIIa inhibitors, abciximab was investigated. In
aggregate, synthetic GP IIb/IIIa inhibitors, combined with aspirin and heparin,
were shown to reduce ischemic events in patients with high- and low-risk coronary
intervention, stents, unstable angina, and non-Q-wave infarction. With short-term
use of synthetic GP IIb/IIIa inhibitors, there is no suppression of clinical
evident restenosis 6 months after the end of treatment. With the doses currently
used, bleeding occurs more often with the synthetic GP IIb/IIIa inhibitors (used
for 3 days) than with abciximab (used for 12 hours), but there are no direct
comparisons between these drugs.
PMID- 10673267
TI - Gene therapy at a crossroads.
PMID- 10673266
TI - Polymorphic ventricular tachycardia and repolarization abnormalities accompanying
intracerebral hemorrhage.
PMID- 10673268
TI - Genome race heats up.
PMID- 10673269
TI - Smallpox virus gets another reprieve.
PMID- 10673270
TI - State of health in State of the Union.
PMID- 10673272
TI - First glimpses
PMID- 10673271
TI - Monday a bad day for hearts.
PMID- 10673273
TI - PON1 status and neurologic symptom complexes in Gulf War veterans.
PMID- 10673274
TI - Genes for cognitive function: developments on the X.
AB - Developments in human genome research enabled the first steps toward a molecular
understanding of cognitive function. That there are numerous genes on the X
chromosome affecting intelligence at the lower end of the cognitive range is no
longer in doubt. Naturally occurring mutations have so far led to the
identification of seven genes accounting for a small proportion of familial
nonspecific X-linked mental retardation. These new data indicate that normal
expression of many more X-linked and autosomal genes contribute to cognitive
function. The emerging knowledge implicating genes in intracellular signaling
pathways provides the insight to identify as candidates other X-linked and
autosomal genes regulating the normal development of cognitive function. Recent
advances in unravelling the underlying molecular complexity have been spectacular
but represent only the beginning, and new technologies will need to be introduced
to complete the picture.
PMID- 10673275
TI - The genomic region encompassing the nephropathic cystinosis gene (CTNS): complete
sequencing of a 200-kb segment and discovery of a novel gene within the common
cystinosis-causing deletion.
AB - Nephropathic cystinosis is an autosomal recessive disorder caused by the
defective transport of cystine out of lysosomes. Recently, the causative gene
(CTNS) was identified and presumed to encode an integral membrane protein called
cystinosin. Many of the disease-associated mutations in CTNS are deletions,
including one >55 kb in size that represents the most common cystinosis allele
encountered to date. In an effort to determine the precise genomic organization
of CTNS and to gain sequence-based insight about the DNA within and flanking
cystinosis-associated deletions, we mapped and sequenced the region of human
chromosome 17p13 encompassing CTNS. Specifically, a bacterial artificial
chromosome (BAC)-based physical map spanning CTNS was constructed by sequence
tagged site (STS)-content mapping. The resulting BAC contig provided the relative
order of 43 STSs. Two overlapping BACs, which together contain all of the CTNS
exons as well as extensive amounts of flanking DNA, were selected and subjected
to shotgun sequencing. A total of 200,237 bp of contiguous, high-accuracy
sequence was generated. Analysis of the resulting data revealed a number of
interesting features about this genomic region, including the long-range
organization of CTNS, insight about the breakpoints and intervening DNA
associated with the common cystinosis-causing deletion, and structural
information about five genes neighboring CTNS (human ortholog of rat vanilloid
receptor subtype 1 gene, CARKL, TIP-1, P2X5, and HUMINAE). In particular,
sequence analysis detected the presence of a novel gene (CARKL) residing within
the most common cystinosis-causing deletion. This gene encodes a previously
unknown protein that is predicted to function as a carbohydrate kinase.
Interestingly, both CTNS and CARKL are absent in nearly half of all cystinosis
patients (i.e., those homozygous for the common deletion). [The sequence data
described in this paper have been submitted to the GenBank data library under
accession nos. AF168787 and AF163573.]
PMID- 10673276
TI - Multiple LTR-retrotransposon families in the asexual yeast Candida albicans.
AB - We have begun a characterization of the long terminal repeat (LTR)
retrotransposons in the asexual yeast Candida albicans. A database of assembled
C. albicans genomic sequence at Stanford University, which represents 14.9 Mb of
the 16-Mb haploid genome, was screened and >350 distinct retrotransposon
insertions were identified. The majority of these insertions represent previously
unrecognized retrotransposons. The various elements were classified into 34
distinct families, each family being similar, in terms of the range of sequences
that it represents, to a typical Ty element family of the related yeast
Saccharomyces cerevisiae. These C. albicans retrotransposon families are
generally of low copy number and vary widely in coding capacity. For only three
families, was a full-length and apparently intact retrotransposon identified. For
many families, only solo LTRs and LTR fragments remain. Several families of
highly degenerate elements appear to be still capable of transposition,
presumably via trans-activation. The overall structure of the retrotransposon
population in C. albicans differs considerably from that of S. cerevisiae. In
that species, retrotransposon insertions can be assigned to just five families.
Most of these families still retain functional examples, and they generally
appear at higher copy numbers than the C. albicans families. The possibility that
these differences between the two species are attributable to the nonstandard
genetic code of C. albicans or the asexual nature of its genome is discussed. A
region rich in retrotransposon fragments, that lies adjacent to many of the CARE
2/Rel-2 sub-telomeric repeats, and which appears to have arisen through multiple
rounds of duplication and recombination, is also described.
PMID- 10673277
TI - The large srh family of chemoreceptor genes in Caenorhabditis nematodes reveals
processes of genome evolution involving large duplications and deletions and
intron gains and losses.
AB - The srh family of chemoreceptors in the nematode Caenorhabditis elegans is very
large, containing 214 genes and 90 pseudogenes. It is related to the str, stl,
and srd families of seven-transmembrane or serpentine receptors. Like these three
families, most srh genes are concentrated on chromosome V, and mapping of their
chromosomal locations on a phylogenetic tree reveals 27 different movements of
genes to other chromosomes. Mapping of intron gains and losses onto the
phylogenetic tree reveals that the last common ancestral gene of the family had
five introns, which are inferred to have been lost 70 times independently during
evolution of the family. In addition, seven intron gains are revealed, three of
which are fairly recent. Comparisons with 20 family members in the C. briggsae
genome confirms these patterns, including two intron losses in C. briggsae since
the species split. There are 14 clear C. elegans orthologs for these 20 genes,
whose average amino acid divergence of 68% allows estimation of 85 gene
duplications in the C. elegans lineage since the species split. The absence of
six orthologs in C. elegans also indicates that gene loss occurs; consideration
of all deletions and terminal truncations of srh pseudogenes reveals that large
deletions are common. Together these observations provide insight into the
evolutionary dynamics of this compact animal genome.
PMID- 10673278
TI - Functional classification of cNMP-binding proteins and nucleotide cyclases with
implications for novel regulatory pathways in Mycobacterium tuberculosis.
AB - We have analyzed the cyclic nucleotide (cNMP)-binding protein and nucleotide
cyclase superfamilies using Bayesian computational methods of protein family
identification and classification. In addition to the known cNMP-binding proteins
(cNMP-dependent kinases, cNMP-gated channels, cAMP-guanine nucleotide exchange
factors, and bacterial cAMP-dependent transcription factors), new functional
groups of cNMP-binding proteins were identified, including putative ABC
transporter subunits, translocases, and esterases. Classification of the
nucleotide cyclases revealed subtle differences in sequence conservation of the
active site that distinguish the five classes of cyclases: the multicellular
eukaryotic adenylyl cyclases, the eukaryotic receptor-type guanylyl cyclases, the
eukaryotic soluble guanylyl cyclases, the unicellular eukaryotic and prokaryotic
adenylyl cyclases, and the putative prokaryotic guanylyl cyclases. Phylogenetic
distribution of the cNMP-binding proteins and cyclases was analyzed, with
particular attention to the 22 complete archaeal and eubacterial genome
sequences. Mycobacterium tuberculosis H37Rv and Synechocystis PCC6803 were each
found to encode several more putative cNMP-binding proteins than other
prokaryotes; many of these proteins are of unknown function. M. tuberculosis also
encodes several more putative nucleotide cyclases than other prokaryotic species.
PMID- 10673279
TI - Extensive genome-wide linkage disequilibrium in cattle.
AB - A genome-wide linkage disequilibrium (LD) map was generated using microsatellite
genotypes (284 autosomal microsatellite loci) of 581 gametes sampled from the
dutch black-and-white dairy cattle population. LD was measured between all marker
pairs, both syntenic and nonsyntenic. Analysis of syntenic pairs revealed
surprisingly high levels of LD that, although more pronounced for closely linked
marker pairs, extended over several tens of centimorgan. In addition, significant
gametic associations were also shown to be very common between nonsyntenic loci.
Simulations using the known genealogies of the studied sample indicate that
random drift alone is likely to account for most of the observed disequilibrium.
No clear evidence was obtained for a direct effect of selection ("Bulmer
effect"). The observation of long range disequilibrium between syntenic loci
using low-density marker maps indicates that LD mapping has the potential to be
very effective in livestock populations. The frequent occurrence of gametic
associations between nonsyntenic loci, however, encourages the combined use of
linkage and linkage disequilibrium methods to avoid false positive results when
mapping genes in livestock.
PMID- 10673280
TI - Thermophilic bacteria strictly obey Szybalski's transcription direction rule and
politely purine-load RNAs with both adenine and guanine.
AB - When transcription is to the right of the promoter, the "top," mRNA-synonymous
strand of DNA tends to be purine-rich. When transcription is to the left of the
promoter, the top, mRNA-template strand tends to be pyrimidine-rich. This
transcription-direction rule suggests that there has been an evolutionary
selection pressure for the purine-loading of RNAs. The politeness hypothesis
states that purine-loading prevents distracting RNA-RNA interactions and
excessive formation of double-stranded RNA, which might trigger various
intracellular alarms. Because RNA-RNA interactions have a distinct entropy-driven
component, the pressure for the evolution of purine-loading might be greater in
organisms living at high temperatures. In support of this, we find that Chargaff
differences (a measure of purine-loading) are greater in thermophiles than in
nonthermophiles and extend to both purine bases. In thermophiles the pressure to
purine-load affects codon choice, indicating that some features of their amino
acid composition (e.g., high levels of glutamic acid) might reflect purine
loading pressure (i.e., constraints on mRNA) rather than direct constraints on
protein structure and function.
PMID- 10673281
TI - Genetic profile of insertion mutations in mouse leukemias and lymphomas.
AB - Murine leukemia retroviruses (MuLVs) cause leukemia and lymphoma in susceptible
strains of mice as a result of insertional mutation of cellular proto-oncogenes
or tumor suppressor genes. Using a novel approach to amplify and sequence viral
insertion sites, we have sequenced >200 viral insertion sites from which we
identify >35 genes altered by viral insertion in four AKXD mouse strains. The
class of genes most frequently altered are transcription factors, however,
insertions are found near genes involved in signal transduction, cell cycle
control, DNA repair, cell division, hematopoietic differentiation, and near many
ESTs and novel loci. Many of these mutations identify genes that have not been
implicated in cancer. By isolating nearly all the somatic viral insertion
mutations contributing to disease in these strains we show that each AKXD strain
displays a unique mutation profile, suggesting strain-specific susceptibility to
mutations in particular genetic pathways.
PMID- 10673282
TI - High-resolution physical map and transcript identification of a prostate cancer
deletion interval on 8p22.
AB - A genomic interval of approximately 1-1.5 Mb centered at the MSR marker on 8p22
has emerged as a possible site for a tumor suppressor gene, based on high rates
of allele loss and the presence of a homozygous deletion found in metastatic
prostate cancer. The objective of this study was to prepare a bacterial contig of
this interval, integrate the contig with radiation hybrid (RH) databases, and use
these resources to identify transcription units that might represent the
candidate tumor suppressor genes. Here we present a complete bacterial contig
across the interval, which was assembled using 22 published and 17 newly
originated STSs. The physical map provides twofold or greater coverage over much
of the interval, including 17 BACs, 15 P1s, 2 cosmids, and 1 PAC clone. The
position of the selected markers across the interval in relation to the other
markers on the larger chromosomal scale was confirmed by RH mapping using the
Stanford G3 RH panel. Transcribed units within the deletion region were
identified by exon amplification, searching of the Human Transcript Map,
placement of unmapped expressed sequence tags (ESTs) from the Radiation Hybrid
Database (RHdb), and from other published sources, resulting in the isolation of
six unique expressed sequences. The transcript map of the deletion interval now
includes two known genes (MSR and N33) and six novel ESTs.
PMID- 10673283
TI - High-throughput SNP allele-frequency determination in pooled DNA samples by
kinetic PCR.
AB - We have developed an accurate, yet inexpensive and high-throughput, method for
determining the allele frequency of biallelic polymorphisms in pools of DNA
samples. The assay combines kinetic (real-time quantitative) PCR with allele
specific amplification and requires no post-PCR processing. The relative amounts
of each allele in a sample are quantified. This is performed by dividing equal
aliquots of the pooled DNA between two separate PCR reactions, each of which
contains a primer pair specific to one or the other allelic SNP variant. For
pools with equal amounts of the two alleles, the two amplifications should reach
a detectable level of fluorescence at the same cycle number. For pools that
contain unequal ratios of the two alleles, the difference in cycle number between
the two amplification reactions can be used to calculate the relative allele
amounts. We demonstrate the accuracy and reliability of the assay on samples with
known predetermined SNP allele frequencies from 5% to 95%, including pools of
both human and mouse DNAs using eight different SNPs altogether. The accuracy of
measuring known allele frequencies is very high, with the strength of correlation
between measured and known frequencies having an r(2) = 0.997. The loss of
sensitivity as a result of measurement error is typically minimal, compared with
that due to sampling error alone, for population samples up to 1000. We believe
that by providing a means for SNP genotyping up to thousands of samples
simultaneously, inexpensively, and reproducibly, this method is a powerful
strategy for detecting meaningful polymorphic differences in candidate gene
association studies and genome-wide linkage disequilibrium scans.
PMID- 10673284
TI - Population screening for haemochromatosis.
PMID- 10673285
TI - Microsatellite instability in colitis associated colorectal cancer.
PMID- 10673286
TI - How should endoscopic accessories be selected: trial or error?
PMID- 10673287
TI - Combination of interferon alpha therapy with non-steroidal anti-inflammatory
drugs in chronic hepatitis C.
PMID- 10673288
TI - Bile acids are physiological ligands for a nuclear receptor.
AB - Bile acids are essential for the solubilization and transport of dietary lipids
and are the major products of cholesterol catabolism. Results presented here show
that bile acids are physiological ligands for the farnesoid X receptor (FXR), an
orphan nuclear receptor. When bound to bile acids, FXR repressed transcription of
the gene encoding cholesterol 7 alpha-hydroxylase, which is the rate-limiting
enzyme in bile acid synthesis, and activated the gene encoding intestinal bile
acid-binding protein, which is a candidate bile acid transporter. These results
demonstrate a mechanism by which bile acids transcriptionally regulate their
biosynthesis and enterohepatic transport.
PMID- 10673289
TI - Risk of ulcer bleeding in patients infected with Helicobacter pylori taking non
steroidal anti-inflammatory drugs.
AB - OBJECTIVE: To determine whether Helicobacter pylori is an independent risk factor
for bleeding peptic ulcer in users of non-steroidal anti-inflammatory drugs
(NSAIDs), including aspirin. DESIGN: A prospective matched case-control study.
SETTING: Odense University Hospital, Denmark. SUBJECTS: 132 patients with a
bleeding peptic ulcer (n=124) or haemorrhagic gastritis (n=8) at endoscopy who
had taken an NSAID in the previous week and 136 controls who had taken NSAIDs
without gastrointestinal complications. The controls were recruited from
rheumatology and geriatric outpatient clinics. MEASUREMENTS: H pylori status
assessed by serology and 13C-urea breath test and regarded as positive if either
test was positive. Data on potential confounding factors including smoking and
alcohol were collected by interview. MAIN RESULT: H pylori was present in 57% of
cases and 43% of controls. The adjusted odds ratio of bleeding from a peptic
ulcer owing to H pylori infection in NSAID users was 1.81 (95% CI 1.02 to 3.21)
and was similar in aspirin and non-aspirin NSAID users. Peptic ulcer bleeding was
also statistically significantly associated with a history of previous ulcer
bleeding, dyspepsia within the previous 3 months, drinking alcohol but not with
smoking. About 16% of bleeding peptic ulcers in NSAID users could be attributed
to H pylori infection. CONCLUSION: NSAID users infected with H pylori have an
almost doubled risk of bleeding peptic ulcer compared with uninfected NSAID
users.
PMID- 10673290
TI - The human trefoil peptide, TFF1, is present in different molecular forms that are
intimately associated with mucus in normal stomach.
AB - BACKGROUND: TFF1 is a 6.5 kDa secreted protein that is expressed predominantly in
normal gastric mucosa. It is coexpressed with mucins and it can form dimers via a
free carboxy terminal cysteine residue. AIMS: To investigate the molecular forms
of TFF1 that are present in normal human stomach and the association of the
different molecular forms with mucus. SUBJECTS: All subjects had macroscopically
normal stomachs at gastroscopy. None had a significant past medical history.
METHODS: TFF1 was detected in normal gastric mucosa and adherent mucus by western
transfer analysis after electrophoresis on reducing and non-reducing
polyacrylamide gels. In some instances, proteins were fractionated by caesium
chloride density gradient centrifugation prior to detection of TFF1. The location
of TFF1 in gastric mucosa with an intact adherent mucus layer was assessed by
immunohistochemistry. RESULTS: Three different molecular forms of TFF1 were
detected: TFF1 monomer, TFF1 dimer, and a TFF1 complex with an apparent molecular
mass of about 25 kDa. TFF1 was present at higher concentrations than realised
previously. The TFF1 complex was present in the adherent mucus gel layer but
while its interaction with mucin was destabilised by caesium chloride, the
interaction between mucin and the TFF1 dimer was resistant to caesium chloride.
CONCLUSIONS: Most of TFF1 in normal human gastric mucosa is present in a complex
that is stabilised by a disulphide bond. TFF1 is intimately associated with
mucus. The high concentration, colocalisation, and binding of TFF1 to gastric
mucus strongly implicate TFF1 in gastric mucus function.
PMID- 10673291
TI - Importance of Helicobacter pylori cagA and vacA status for the efficacy of
antibiotic treatment.
AB - BACKGROUND: Virulence factors of Helicobacter pylori are associated with peptic
ulcer disease and may be also associated with the efficacy of treatment. AIMS: To
determine the relation between the vacA and the cagA status of H pylori, clinical
disease, and treatment outcome. PATIENTS: 121 patients with H pylori infection
and peptic ulcer disease or functional dyspepsia were treated by quadruple
antibiotic therapy in two groups for one and two days, respectively. METHODS: DNA
was isolated from gastric antral biopsy specimens, taken before and after
treatment, and the vacA and cagA status was determined by polymerase chain
reaction and reverse hybridisation. RESULTS: Peptic ulcer disease was
significantly associated with the vacA s1 type, and cagA positivity, but not with
the vacA m type. Treatment efficacy was significantly higher in patients with
peptic ulcer disease, or infected with cagA+/vacA s1 strains. CONCLUSIONS: The
strong association between the cagA and vacA status and peptic ulcer disease was
confirmed. Cure rates seem to be higher for patients with cagA+/vacA s1 H pylori
strains, which is consistent with the higher cure rate observed among ulcer
patients compared with functional dyspepsia patients. Therefore, treatment
studies may require stratification for presence of ulcers as well as H pylori
genotypes.
PMID- 10673292
TI - Lack of cellular and humoral immunological responses to oats in adults with
coeliac disease.
AB - OBJECTIVE: Recent research suggests that oats do not harm intestinal villi in
adults with coeliac disease. As the immunological effects of oats have not been
examined in detail, it was decided to compare the immunological responses of a
gluten free diet including oats with those of a conventional gluten free diet.
DESIGN: A randomised controlled intervention study over 6-12 months. SUBJECTS:
Forty adults with newly diagnosed coeliac disease and 52 with coeliac disease in
remission were examined. INTERVENTION: The effects of a gluten free diet
including oats and a conventional gluten free diet were compared. MAIN OUTCOME
MEASURES: Serum levels of gliadin and reticulin antibodies as well as numbers of
intraepithelial lymphocytes (IELs) in intestinal mucosa were examined before and
after the intervention. RESULTS: The rate of disappearance of gliadin and
reticulin antibodies did not differ between the diet groups in patients with
newly diagnosed coeliac disease. Oats also had no effect on gliadin or reticulin
antibody levels in the patients with remission. The number of IELs decreased
similarly regardless of the diet of newly diagnosed patients, and no increase in
the number of IELs was found in the patients in remission with or without oats.
CONCLUSIONS: These results strengthen the view that adult patients with coeliac
disease can consume moderate amounts of oats without adverse immunological
effects.
PMID- 10673293
TI - Coeliac disease and unfavourable outcome of pregnancy.
AB - BACKGROUND: Up to 50% of women with untreated coeliac disease experience
miscarriage or an unfavourable outcome of pregnancy. In most cases, after 6-12
months of a gluten free diet, no excess of unfavourable outcome of pregnancy is
observed. The prevalence of undiagnosed coeliac disease among pregnant women is
not known. AIM: To determine the prevalence of untreated coeliac disease among
women attending the obstetrics-gynaecological department. METHODS: Endomysial
antibodies, which are specific and sensitive for coeliac disease, were evaluated
in all women attending the obstetrics-gynaecology department of a large city
hospital over a 90 day period. RESULTS: Of 845 pregnant women screened, 12 were
identified as having coeliac disease. Three had previously been diagnosed but
were not following a gluten free diet. The remaining nine underwent a small
intestinal biopsy, which confirmed the diagnosis. The outcome of pregnancy was
unfavourable in seven of these 12 women. Six healthy babies were born with no
problems after the women had been on a gluten free diet for one year.
CONCLUSIONS: Overall, 1 in 70 women was affected by coeliac disease, either not
diagnosed (nine cases) or not treated (three cases). Their history of
miscarriages, anaemia, low birth weight babies, and unfavourable outcome of
pregnancy suggests that testing for coeliac disease should be included in the
battery of tests prescribed for pregnant women. Coeliac disease is considerably
more common than most of the diseases for which pregnant women are routinely
screened. Unfavourable events associated with coeliac disease may be prevented by
a gluten free diet.
PMID- 10673294
TI - Ulcerative colitis in Olmsted County, Minnesota, 1940-1993: incidence,
prevalence, and survival.
AB - BACKGROUND: There is significant geographic variation in the reported incidence
of ulcerative colitis. AIMS: To update the incidence and prevalence of ulcerative
colitis in Olmsted County, Minnesota, examine temporal trends, and determine
overall survival. PATIENTS: All Olmsted County residents diagnosed with
ulcerative colitis between 1940 and 1993 (incidence cases), and all residents
with ulcerative colitis alive on 1 January 1991 (prevalence cases). METHODS:
Incidence and prevalence rates were adjusted using 1990 US census figures for
whites. The effects of age, sex, and calendar year on incidence rates were
evaluated using Poisson regression. Survival from diagnosis was compared with
that expected for US north-central whites. RESULTS: Between 1940 and 1993, 278
incidence cases were identified, for an adjusted incidence rate of 7.6 cases per
100 000 person years (95% confidence interval (CI), 6.7 to 8.5). On 1 January
1991, there were 218 residents with definite or probable ulcerative colitis, for
an adjusted prevalence rate of 229 cases per 100 000 (95% CI, 198 to 260).
Increased incidence rates were associated with later calendar years (p<0.002),
younger age (p<0.0001), urban residence (p<0.0001), and male sex (p<0.003).
Overall survival was similar to that expected (p>0.2). CONCLUSIONS: The overall
incidence rate of ulcerative colitis in Olmsted County increased until the 1970s,
and remained stable thereafter. Incidence rates among men and urban residents
were significantly higher. The prevalence rate in Rochester in 1991 was 19%
higher than that in 1980. Overall survival was similar to that of the general
population.
PMID- 10673295
TI - Interleukin 10 gene transfer prevents experimental colitis in rats.
AB - BACKGROUND: The development of colitis in interleukin 10 (IL-10) deficient mice,
together with the known anti-inflammatory and immunomodulatory properties of this
cytokine have prompted consideration of IL-10 as a treatment for inflammatory
bowel disease (IBD). However, studies using hrIL-10 in IBD models have yielded
inconsistent results. AIMS: To examine the therapeutic potential of
overexpressing the IL-10 gene before and after the induction of experimental
colitis in rats. METHODS: Gene transfer was achieved by intraperitoneal injection
of non-replicating human type 5 adenovirus bearing the IL-10 gene, either 24
hours before or one hour after intrarectal administration of dinitrobenzene
sulphonic acid in rats. Colonic damage and inflammation was assessed
macroscopically and by measuring myeloperoxidase activity and leukotriene B4
concentrations. RESULTS: Gene transfer increased IL-10 protein in serum for up to
six days. IL-10 gene transfer prior to colitis improved colitis macroscopically
and histologically, and significantly reduced colonic myeloperoxidase activity
and leukotriene B4 concentrations. In contrast, IL-10 gene transfer after the
onset of colitis had no beneficial effect. CONCLUSIONS: Gene therapy using an
adenovirus-IL-10 construct was successful in preventing but not in reversing
experimental colitis in the rat.
PMID- 10673296
TI - Human intestinal epithelial cells secrete interleukin-1 receptor antagonist and
interleukin-8 but not interleukin-1 or interleukin-6.
AB - BACKGROUND: There is growing evidence that intestinal epithelial cells (IECs) are
involved in the mucosal immune system. AIM: To assess the pattern of cytokines
secreted by IECs and lamina propria mononuclear cells (LPMNCs). To achieve this,
the expression and secretion of interleukin (IL)-1, IL-1 receptor antagonist (IL
1ra), IL-6, and IL-8 in human primary colonic and ileal IECs and LPMNCs from the
same patient were studied. METHODS: IECs and LPMNCs were isolated from surgical
specimens or endoscopic biopsy samples. mRNA expression was investigated by
northern blot analysis. Secretion of IL-1beta, IL-6, IL-8, and IL-1ra was
measured by enzyme linked immunosorbent assay. RESULTS: IL-1ra mRNA levels were
higher in IECs than in LPMNCs in all probands. IL-8 mRNA was only present in low
amounts in the IECs from two controls. In none of the specimens were IL-1beta and
IL-6 mRNA present in IECs. Transcripts encoding IL-1beta, IL-1ra, IL-6, and IL-8
were identified in LPMNC preparations of all specimens. IECs from normal mucosa
produced no detectable amounts of IL-1beta or IL-6, whereas LPMNCs did. IECs
secreted some IL-8 (65 (9) pg/10(5) cells) but significantly more was generated
by LPMNCs (408 (43) pg/10(5) cells, p<0.0001). However, IECs secreted more IL-1ra
than did LPMNCs (120 (12) v 94 (11) pg/10(5) cells). In acute inflammation, IEC
IL-1ra secretion was significantly increased. A correlation between secreted IL
1ra and the macroscopical degree of inflammation was found in Crohn's disease (r
= 0.64, p<0.0001, n = 36) and ulcerative colitis (r = 0. 76, p<0.0001, n = 24).
CONCLUSIONS: IECs from normal mucosa express and secrete IL-1ra and low amounts
of IL-8, but no IL-1 or IL-6. In inflamed mucosa the secretion of IL-1ra by IECs
is slightly increased but may be not sufficient to antagonise the greatly
increased production of proinflammatory cytokines by LPMNCs and the IECs
themselves.
PMID- 10673297
TI - Altered mRNA expression of glycosyltransferases in human colorectal carcinomas
and liver metastases.
AB - BACKGROUND/AIMS: Biosynthesis of carbohydrate structures is tissue specific and
developmentally regulated by glycosyltransferases such as fucosyltransferases,
sialyltransferases, and N-acetylgluco- saminyltransferases. During
carcinogenesis, aberrant glycosylation leads to the development of tumour
subpopulations with different adhesion properties. Therefore alterations in
glycosyltransferase mRNA expression in colorectal carcinomas were examined by
semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).
METHODS: Colorectal carcinoma specimens were classified and characterised
according to the WHO/UICC system. Expression of fucosyltransferases FT-I, FT-III,
FT-IV, FT-V, FT-VI, and FT-VII, sialyltransferases ST3Gal-I, ST3Gal-III, ST3Gal
IV, and ST6Gal-I, beta1,4-galacto- syltransferase, and beta1,6-Nacetylgluco-
saminyltransferase V (GNT-V) was screened simultaneously in extracts of 22
homogenised tumour specimens by RT-PCR and compared with corresponding mucosa
from each patient. Also 12 adenomas and 17 liver metastases of colorectal
carcinomas were examined. RESULTS: GNT-V expression was enhanced in colorectal
adenomas (p = 0.039), carcinomas (p<0.001), and liver metastases of colorectal
carcinomas (p<0.001). Also, expression of fucosyltransferase FT-IV was increased
in colorectal adenomas (p = 0.039) and carcinomas (p<0. 001). In addition,
fucosyltransferase FT-I (p<0.001) and sialyltransferases ST6Gal-I (p = 0.004) and
ST3Gal-III (p = 0.001) showed increased expression in carcinoma specimens. On the
other hand, fucosyltransferase FT-III was less abundantly expressed in carcinomas
exhibiting distant metastases (p = 0.046) and in highly invasive tumours (p =
0.041). CONCLUSIONS: Glycosyltransferase mRNA expression is significantly altered
in colorectal adenomas and carcinomas isolated from surgical specimens. RT-PCR
determination of specific glycosyltransferases may be helpful for earlier
detection of carcinomas and for tumour prognosis.
PMID- 10673299
TI - Pathways and receptors involved in peptide YY induced contraction of rat proximal
colonic muscle in vitro.
AB - BACKGROUND: Peptide YY (PYY) is involved in the regulation of several gut
functions, including secretion and motility. It exerts its effects through a
family of six receptors, commonly named the Y receptor family. AIMS: To
characterise the effects of PYY on strips of rat proximal colon in vitro, and to
determine the pathways and receptors involved. METHODS: Contractions of strips
removed from the muscle layer of rat proximal colon were recorded under isometric
conditions, using PYY, Y receptor agonists and antagonists, and nerve blockers.
Reverse transcription-polymerase chain reaction was also performed to detect the
presence of mRNA coding for Y receptors. Finally, smooth muscle cells were
isolated to estimate the cell length and intracellular Ca(2+) concentration in
the presence and absence of PYY. RESULTS: PYY, neuropeptide Y (NPY), pancreatic
polypeptide (PP) and [Leu31,Pro34]NPY induced a dose dependent contraction of
strips from proximal colon. Tetrodotoxin partially inhibited the PYY and NPY
induced contractions, and strongly inhibited the PP induced contraction. Specific
antagonists showed the involvement of cholinergic nicotinic receptors and NK1
receptor. BIBP 3226, a specific Y1 antagonist, did not modify the colonic smooth
muscle response to PYY, whereas blocking L-type Ca(2+) channels with D-600
abolished its effects. Moreover, PYY induced an increase in intracellular Ca(2+)
concentration, associated with a reduction in cell length. mRNA encoding Y1 and
Y4 receptors were detected in the muscle strips. CONCLUSIONS: These findings
suggest that PYY stimulates colonic contractile activity in vitro through (a) a
nervous Y4 dependent pathway and (b) a pathway involving a potential new receptor
on myocytes.
PMID- 10673298
TI - Defective hMSH2/hMLH1 protein expression is seen infrequently in ulcerative
colitis associated colorectal cancers.
AB - BACKGROUND: Ulcerative colitis is associated with an increased risk of colorectal
cancer above that of the normal population. The relative risk correlates with the
extent and duration of the disease but the genetic basis of ulcerative colitis
associated cancer risk is not known. AIMS: To assess the prevalence of
microsatellite instability and mismatch repair gene abnormalities in ulcerative
colitis associated colorectal cancer. PATIENTS: Forty six patients with
colorectal cancer, with a previous histological diagnosis of ulcerative colitis.
METHODS: The frequency of microsatellite instability and/or immunohistochemical
expression of hMSH2 and hMLH1 was assessed. Thirty three cases were investigated
using both approaches. RESULTS: Although 6/41 (14.6%) cases showed microsatellite
instability at one or more markers, only one case (2. 4%) exhibited high level
instability (at least two markers affected). Of 38 cases which were assessed
using antibodies against hMSH2 and hMLH1, only one case (2.6%) showed loss of
expression. This case, which showed loss of hMSH2 expression, was the same case
which exhibited high level microsatellite instability. The 33 cases which were
investigated using both approaches showed that loss of expression of either hMSH2
or hMLH1 was not seen in any case which exhibited microsatellite instability in
no more than one marker. CONCLUSIONS: This study suggests that both high level
microsatellite instability and loss of expression of hMSH2/hMLH1 are infrequent
events in ulcerative colitis associated colorectal cancers. Low level
microsatellite instability was not associated with loss of expression of either
hMSH2 or hMLH1.
PMID- 10673300
TI - Pressure and frequency dependent linkage between motility and epithelial
secretion in human proximal small intestine.
AB - BACKGROUND: Motor disturbances are sometimes associated with diarrhoea by unknown
mechanisms. AIM: To determine if there is a quantitative link between intestinal
motility and epithelial secretion. SUBJECTS: Experiments were performed in 21
healthy volunteers and three patients with villus atrophy. METHODS: Duodenal and
jejunal motor activities were registered in the fasted state by open tip
manometry. Secretion was measured directly by marker perfusion and indirectly by
recording transmural potential difference (PD). RESULTS: A significant
correlation was found between "low pass filtered" pressure and PD, but no
correlation was found between amplitudes of isolated contractions and PD changes.
During repeated phasic contractions (phase III of migrating motor complex), PD
increased at a rate that was higher in the duodenum than in the jejunum, and
higher in patients with villus atrophy than in healthy controls. After reaching a
peak, PD decreased despite continuing phasic motor activity, provided that there
was no concomitant increase in mean pressure. Fluid secretion increased roughly
in parallel with PD, except at the very end of the cycle. CONCLUSIONS: To explain
these findings, one has to postulate participation of at least two types of
receptor: a slowly adapting pressure sensitive receptor and another
mechanoreceptor, possibly a mucosal touch receptor, to account for the run down
phenomenon. This model predicts that short lasting trains of contractions, so
called discrete clusters, will be a particularly potent stimulus for activation
of mucosal secretion.
PMID- 10673301
TI - Acute pancreatitis in peritoneal dialysis and haemodialysis: risk, clinical
course, outcome, and possible aetiology.
AB - BACKGROUND: It has been suggested that the incidence of acute pancreatitis in
patients with end stage renal failure is increased. AIMS: To assess the risk of
acute pancreatitis in patients on long term peritoneal dialysis and long term
haemodialysis compared with the general population, to evaluate its clinical
course and outcome, and to identify possible aetiological factors. PATIENTS: All
patients who were maintained on long term peritoneal dialysis and/or
haemodialysis (total dialysis time more than six weeks) from January 1989 to
March 1998 in a large general hospital in The Netherlands. METHODS: Retrospective
cohort study. Standardised ratios (as an approximate relative risk) between the
incidence of acute pancreatitis in haemodialysis or peritoneal dialysis and the
general population were calculated. Possible risk factors were identified.
Patients with and without acute pancreatitis were compared. RESULTS: In 269
patients on haemodialysis (total of 614 person years), one patient developed an
attack of acute pancreatitis. Patients on haemodialysis did not show an increased
risk for acute pancreatitis compared with the general population (standardised
ratio 11; 95% confidence interval (CI) 0.275 to 60.5). In 128 patients on
peritoneal dialysis (total of 241 person years), seven patients had nine attacks
of acute pancreatitis. Patients on peritoneal dialysis had a significantly and
highly increased risk for acute pancreatitis (standardised ratio 249; 95% CI 114
to 473). Mortality in this series of nine attacks was 11%. No single aetiological
risk factor could be identified. CONCLUSIONS: The risk of acute pancreatitis in
patients on long term peritoneal dialysis is significantly and highly increased
compared with the general population. The underlying causal mechanisms remain to
be elucidated.
PMID- 10673302
TI - Effect of endothelin and endothelin receptor blockade on capillary permeability
in experimental pancreatitis.
AB - BACKGROUND: Capillary leakage with fluid loss into the third space contributes to
many of the early systemic complications in severe acute pancreatitis. There has
been increasing interest in endothelin as one of the factors affecting capillary
permeability. AIM: To elucidate further the role of endothelin in the development
of capillary leakage in acute pancreatitis by investigating the effect of
exogenous endothelin administration and endothelin receptor blockade in sham
operated animals and two models of acute pancreatitis. METHODS: Determination of
capillary permeability in the pancreas and colonic mucosa by quantifying
extravasation of fluorescein labelled dextran using a novel computer assisted
video image analysis system. RESULTS: Pancreatic and colonic capillary
permeability increased stepwise from mild to severe acute pancreatitis.
Endothelin increased pancreatic and colonic capillary permeability in healthy
animals and animals with mild acute pancreatitis but had no additional adverse
effect in severe acute pancreatitis. Endothelin receptor blockade decreased
pancreatic capillary permeability in sham operated rats but had no effect on the
colon. In mild and severe acute pancreatitis, endothelin receptor blockade
stabilised increased capillary permeability in both the pancreas and colon.
CONCLUSIONS: Endothelin plays an important role in mediating capillary
permeability in the pancreas. In severe pancreatitis, it increases capillary
permeability even outside the pancreas, thereby contributing to capillary
leakage. Endothelin receptor blockade significantly reduces capillary
permeability in acute pancreatitis both in and outside the pancreas, suggesting a
therapeutic approach to counteract capillary leakage in severe acute
pancreatitis.
PMID- 10673303
TI - A prospective randomised multicentre trial comparing 10 Fr Teflon Tannenbaum
stents with 10 Fr polyethylene Cotton-Leung stents in patients with malignant
common duct strictures.
AB - BACKGROUND: Stent blockage is a multifactorial process in which stent design and
materials, bacteria, proteins, and bile viscosity play a role. AIMS: To compare
the patency of the 10 Fr Teflon Tannenbaum (TT) stent to that of the 10 Fr Cotton
Leung (CL) polyethylene stent with sideholes, in patients with malignant
obstructive jaundice. METHODS: Patients were recruited to this prospective
multicentre randomised study if they had a newly diagnosed malignant bile duct
stricture below the hilum of the liver suitable for stenting with a 10 Fr stent.
Data were collected and monitored by a professional monitoring company. Primary
patency was the interval between stent placement and first exchange or death
without recurrent jaundice. RESULTS: 134 consecutive patients were recruited
between November 1994 and June 1997; 65 were randomised to the TT stent and 69 to
the CL stent. Median patency and 95% confidence intervals were 181 (59, 303) days
for the TT stent and 133 (92, 174) days for the CL stent, with no significant
difference between the two stents (p=0.49). Median survival and 95% confidence
intervals were 115 (71, 159) days for the TT stent and 151 (112, 190) days for
the CL stent, with no significant difference between the two stents (p=0.765).
CONCLUSION: Neither Teflon as a stent material nor the Tannenbaum design prolong
the patency of plastic stents.
PMID- 10673304
TI - Incidence of liver disease in people with HFE mutations.
AB - BACKGROUND: Most patients with haemochromatosis have mutations of the HFE gene.
However, the risk to people with HFE mutations of developing disease
manifestations of haemochromatosis is not known. AIMS: To determine the risk of
developing cirrhosis and liver cancer in individuals with HFE mutations in a
population where few people were being treated for haemochromatosis. METHODS: 215
archive biopsy specimens of liver cancer (n=34) and cirrhosis (n=190) were
retrieved from histology archives. Blood samples from 1000 individuals from the
normal population were also collected. DNA was extracted from the biopsy
specimens and exons 2 and 4 of the HFE gene were amplified using polymerase chain
reaction. The products were analysed for the C282Y (845A) and H63D (187G)
mutations. RESULTS: Three (8.8%) patients from the liver cancer group were
homozygous for the C282Y mutation. Five (2.6%) patients from the cirrhosis group
were homozygous for the C282Y mutation. One case fell in both the liver cancer
and cirrhosis groups. C282Y homozygosity was thus significantly more frequent in
both groups than in the normal population. These 215 cases are representative of
a population of about 250 000 over 20 years. During this period we estimate that
about 260 births or deaths of C282Y homozygous individuals occurred within this
population. CONCLUSIONS: A diagnosis of liver cancer or cirrhosis is rare in the
lifetime of individuals from this population who are homozygous for the C282Y
mutation (2.5%; upper 95% confidence interval (CI) = 8%). Similarly liver disease
is rare among C282Y/H63D compound heterozygotes (1%; upper 95% CI = 3.5%).
PMID- 10673305
TI - Automated measurement of unsaturated iron binding capacity is an effective
screening strategy for C282Y homozygous haemochromatosis.
AB - BACKGROUND: C282Y hereditary haemochromatosis is an appropriate condition for
population screening. Transferrin saturation, the best screening test to date, is
relatively expensive, labour intensive, and cannot be automated. Unsaturated iron
binding capacity is a surrogate marker of transferrin saturation and its
measurement can be automated. AIMS: To evaluate a screening strategy for C282Y
hereditary haemochromatosis in a tertiary hospital environment based on
unsaturated iron binding capacity as the initial screening test. METHODS:
Measurement of unsaturated iron binding capacity was adapted to the main
laboratory analyser. An unsaturated iron binding capacity of less than 30
micromol/l was identified as an appropriate decision point and 5182 consecutive
subjects were screened over 28 consecutive days. RESULTS: Of those screened, 697
had an unsaturated iron binding capacity less than 30 micromol/l. Of these,
transferrin saturation was greater than 40% in 294. A total of 227 were able to
be genotyped for the C282Y mutation. Nine subjects homozygous for C282Y were
identified. Based on full cost recovery, affected persons were identified at a
cost of Aus$2268.77 per case (approximately US$1496). CONCLUSION: Automated
measurement of unsaturated iron binding capacity enables a cost effective, large
scale population screening programme for C282Y hereditary haemochromatosis to be
developed.
PMID- 10673306
TI - Serum antibodies to Helicobacter hepaticus and Helicobacter pylori in patients
with chronic liver disease.
AB - BACKGROUND: Bile tolerant helicobacter species such as H hepaticus and H bilis
have frequently been reported to cause hepatitis in mice and other rodents. AIMS:
To investigate the possible pathogenic role of these and other helicobacter
species in chronic liver disease in humans. METHODS: Serum samples from 144
patients with various chronic liver diseases, 30 patients with primary sclerosing
cholangitis (PSC), and 48 healthy blood donors were analysed for antibodies
against H hepaticus murine strain CCUG 33637 and H pylori strain CCUG 17874. Cell
surface proteins of H hepaticus were extracted by acid glycine buffer and used in
an enzyme immunoassay (EIA) and immunoblot (IB). RESULTS: 56 of 144 (39%)
patients with chronic liver diseases and six of 30 (20%) with PSC showed
increased antibody concentrations in the H hepaticus EIA; in the H pylori EIA the
numbers were 58% and 13% respectively. Compared with the healthy blood donors the
antibody reactivity against the two helicobacter species was not increased (46%
and 48% respectively). Patient serum samples retested by the H hepaticus EIA
after absorption with sonicated H pylori cells remained positive in 12 of 37
(33%) serum samples. Distinct antibody reactivity to 55-65 kDa proteins was
observed by H hepaticus IB, after the absorption step, and was considered
specific for H hepaticus. These 12 serum samples were from patients with chronic
alcoholic liver disease. CONCLUSIONS: Antibodies to H hepaticus, often cross
reacting with H pylori, occur frequently in patients with chronic liver diseases,
with no clear cut relation to specific diagnostic groups. The pathogenic
significance of these findings is not known.
PMID- 10673307
TI - Diagnosis of Wilson's disease: an experience over three decades.
AB - BACKGROUND: Wilson's disease is a rare but treatable condition that often
presents diagnostic dilemmas. These dilemmas have for the most part not been
resolved by the identification and cloning of the Wilson's disease gene. AIMS: To
report our experience over three decades with patients with Wilson's disease in
order to illustrate the diverse patterns of presentation and thereby broaden the
approach to diagnosis. METHODS: Clinical and laboratory findings of 30 patients
with Wilson's disease were reviewed. RESULTS: Twenty two patients presented with
liver manifestations (eight with fulminant hepatic failure and 14 with chronic
liver disease), three with neurological disease, and one with haemolysis; four
were asymptomatic siblings of patients with Wilson's disease. Seventy per cent
were diagnosed within six months of the onset of symptoms, but diagnosis was
delayed for up to nine years. Age range at diagnosis was wide (7-58 years) and
five patients were over 40. In patients presenting with non-fulminant disease,
18% had neither Kayser-Fleischer rings nor low caeruloplasmin concentrations.
Increased liver copper concentrations were found in all but one patient who had
undergone six years of penicillamine treatment. In fulminant hepatic failure
(n=8) additional features helpful in the diagnosis included evidence of
haemolysis, increased urinary copper (range 844-9375 microg/24 h), and a high non
caeruloplasmin copper (range 325-1743 microg/l). CONCLUSIONS: The diagnosis of
Wilson's disease still depends primarily on the evaluation of clinical and
laboratory evidence of abnormal copper metabolism. No one feature is reliable,
but the diagnosis can usually be made provided that it is suspected. Wilson's
disease should be considered in patients of any age with obscure hepatic or
neurological abnormalities.
PMID- 10673308
TI - Influence of hepatitis delta virus infection on morbidity and mortality in
compensated cirrhosis type B. The European Concerted Action on Viral Hepatitis
(Eurohep).
AB - BACKGROUND: The effect of hepatitis delta virus (HDV) infection on the clinical
course of cirrhosis type B is poorly defined. AIMS: To investigate the impact of
HDV status on morbidity and mortality in cirrhosis type B. PATIENTS/METHODS:
Retrospective cohort study of 200 Western European patients with compensated
cirrhosis type B followed for a median period of 6.6 years. RESULTS: At
diagnosis, 20% of patients had antibodies to HDV (anti-HDV); median age was lower
in anti-HDV positive cirrhotics (34 v 48 years respectively). Kaplan-Meier five
year probability of hepatocellular carcinoma (HCC) was 6, 10, and 9% in anti-HDV
positive/HBeAg negative, anti-HDV negative/HBeAg negative, and anti-HDV
negative/HBeAg positive cirrhotics respectively; the corresponding figures for
decompensation were 22, 16, and 19% and for survival they were 92, 89, and 83%
respectively. Cox regression analysis identified age, albumin concentration,
gamma-globulin concentration, and HDV status as significant independent
prognostic variables. After adjustment for clinical and serological differences
at baseline, the risk (95% confidence interval) for HCC, decompensation, and
mortality was increased by a factor of 3.2 (1.0 to 10), 2.2 (0.8 to 5.7), and 2.0
(0.7 to 5.7) respectively in anti-HDV positive relative to HDV negative cirrhotic
patients. The adjusted estimated five year risk for HCC was 13, 4, and 2% for
anti-HDV positive/HBeAg negative, anti-HDV negative/HBeAg negative, and anti-HDV
negative/HBeAg positive cirrhotics respectively; the corresponding figures for
decompensation were 18, 8, and 14% and for survival 90, 95, and 93% respectively.
CONCLUSIONS: HDV infection increases the risk for HCC threefold and for mortality
twofold in patients with cirrhosis type B.
PMID- 10673309
TI - Interferon-alpha 2b combined with daily ketoprofen administration improves
virological response in chronic hepatitis C: a prospective and randomised trial.
AB - BACKGROUND: Less than 15% of patients with chronic hepatitis C show a sustained
virological response to interferon treatment. AIM: To evaluate the efficacy and
safety of different doses of ketoprofen combined with interferon-alpha 2b in the
treatment of chronic hepatitis C. PATIENTS/METHODS: Seventy compensated patients
with chronic hepatitis C received interferon-alpha 2b 3 million units three times
a week for six months. They were randomly assigned to: group 1 (n = 23),
interferon-alpha 2b alone; group 2 (n = 23), interferon-alpha 2b plus 200 mg
ketoprofen three times a week; group 3 (n = 24), interferon-alpha 2b plus 200 mg
ketoprofen twice a day. Complete and sustained responses were defined as normal
serum alanine aminotransferase levels and negative serum hepatitis C virus RNA at
six and 12 months respectively. RESULTS: Complete and sustained responses were
similar in groups 1 and 2: 10% v 5% and 5% v 0% respectively. In group 3,
complete response was 29% (p = 0.13 v group 1 and p = 0.04 v group 2) and
sustained response was 26% (p = 0.07 v group 1 and p = 0.01 v group 2). Overall,
adverse events were similar in the three groups. However, 'flu-like syndrome was
less common in group 2 (30%) and group 3 (37%) than in group 1 (77%) (p = 0.01).
CONCLUSIONS: Twice daily ketoprofen administration combined with interferon-alpha
2b produced an increase in complete and sustained responses. Although the
combination of interferon-alpha 2b with ketoprofen was well tolerated and
decreased the incidence of 'flu-like syndrome, it is advisable to monitor
possible non-steroid anti-inflammatory drug hepatotoxicity.
PMID- 10673310
TI - Possible paracrine growth of adenocarcinoma of the stomach induced by granulocyte
colony stimulating factor produced by squamous cell carcinoma of the oesophagus.
AB - Synchronous cancers of the oesophagus and stomach diagnosed in a patient showing
pronounced leucocytosis were examined for production of granulocyte colony
stimulating factor (G-CSF) and expression of G-CSF receptor. Whereas enzyme
immunoassay of tissue extracts showed that the oesophageal carcinoma produced G
CSF, the gastric cancer did not. However, the gastric tumour showed G-CSF
receptor expression on immunohistochemical examination of sections. These
findings suggest that the oesophageal cancer promoted gastric cancer growth by
paracrine mechanisms involving G-CSF.
PMID- 10673311
TI - Lidocaine toxicity in a student undergoing upper gastrointestinal endoscopy.
PMID- 10673312
TI - Peroxynitrite and inflammatory bowel disease.
PMID- 10673314
TI - Molecule liftoff from surfaces.
AB - Molecular dynamics simulations have been used to model the kiloelectronvolt
particle bombardment of organic layers on metal substrates such as occurs in the
analytical techniques of secondary ion mass spectrometry and fast atom
bombardment mass spectrometry. Vignettes of insights gained from the simulations
along with comparisons to experimental data are presented in this Account. Topics
include intact molecular ejection vs fragmentation, prediction of reaction
pathways, influence of the substrate, and quantitative predictions of energy and
angular distributions.
PMID- 10673315
TI - Hybrid electrochemical/chemical synthesis of quantum dots.
AB - The "electrochemical/chemical method" (or "E/C method") is a new wet chemical
method for synthesizing semiconductor quantum dots on graphite surfaces. The E/C
synthesis of quantum dots composed of the generic semiconducting salt, MX,
typically involves three steps: (1) electrochemical deposition of nanoparticles
of the metal, M degrees, from a solution of metal ions, M(n)(+); (2)
electrochemical oxidation of these metal particles to MO(n)()(/2), and; (3)
displacement of the oxygen from MO(n)()(/2) using HX (for example) to yield
nanoparticles of MX. This conversion from metal to metal oxide to metal salt
occurs on a particle-by-particle basis; that is, each metal nanoparticle is
converted into a semiconductor nanoparticle. E/C-synthesized beta-CuI and CdS
quantum dots possess many of the attributes of quantum dots synthesized using
molecular beam epitaxy, including epitaxial orientation on the graphite surface,
a narrow size dispersion, and strong, particle size-tunable photoluminescence.
However, the E/C method is faster, cheaper, and applicable to a greater number of
materials.
PMID- 10673316
TI - What controls the rates of interprotein electron-transfer reactions.
AB - Rates of electron-transfer (ET) reactions are dependent on driving force,
reorganizational energy, distance, and the nature of the medium which the
electron must traverse. In kinetically complex biological systems, non-ET
reactions may be required to activate the system for ET and may also influence
the observed rates. Studies of ET from tryptophan tryptophylquinone to copper to
heme in the methylamine dehydrogenase-amicyanin-cytochrome c-551i ET complex, as
well as studies of other physiologic redox protein complexes, are used to
illustrate the combination of factors which control rates of interprotein ET
reactions.
PMID- 10673317
TI - Biomaterials in drug delivery and tissue engineering: one laboratory's
experience.
AB - This Account reviews our laboratory's research in biomaterials. In one area, drug
delivery, we discuss the development of materials that are capable of releasing
macromolecules such as proteins and peptides, intelligent delivery systems based
on magnetism or microchip technology, new degradable materials such as
polyanhydrides, and noninvasive approaches for delivering molecules through the
skin and lungs. A second area, tissue engineering, is also discussed. New polymer
systems for creating cartilage, blood vessels, nerves, and other tissues are
examined.
PMID- 10673318
TI - Organic synthesis and chemical ecology.
AB - The roles of organic synthesis in chemical ecology are discussed, with many
examples. The structure, including the absolute configuration, of a semiochemical
(signal substance) can be established by enantioselective synthesis. Only through
synthesis can a semiochemical be obtained in an amount sufficient for decisive
biological evaluation. Rigorous enantioselective synthesis of semiochemicals to
provide their pure enantiomers has shown that they are not always
enantiomerically pure. Synthesis of the stereoisomers of semiochemicals has
clarified their structure-bioactivity relationships to reveal the unprecedented
diversity in the stereochemical aspects of pheromone communications.
PMID- 10673319
TI - Femtosecond studies of electron dynamics at interfaces.
AB - A delocalized electron at a metal-dielectric interface interacts with the adlayer
and spatially localizes or self-traps on the femtosecond time scale into what is
termed a small polaron. The dynamics can be studied by two-photon photoemission.
Theoretical and experimental analyses reveal the interaction energy and the
lattice vibrational mode that mediates electron localization. These results
contribute to a fundamental understanding of electron behavior in weakly bonded
solids and can lead to a better understanding of carrier dynamics in many
different systems, including organic light-emitting diodes.
PMID- 10673320
TI - What do titano- and zirconocenes do with diynes and polyynes?
AB - A thorough investigation of the reactions of diynes, R(C&tbd1;C)(2)R, and
polyynes, R(C&tbd1;C)(n)()R, with titanocene and zirconocene was performed using
the metallocene sources Cp(2)M(L)(eta(2)-Me(3)SiC&tbd1;CSiMe(3)) (M = Ti, L = -;
M = Zr, L = THF, pyridine). The conversions show an array of different products
generated in complexation, coupling, and cleavage reactions. These results
include remarkable structures (e.g., five-membered metallacyclocumulenes) and
reactions (e.g., C-C single-bond cleavage). In addition, the first C-C single
bond metathesis in homogeneous solution was discovered. The presented findings
have been supported by theoretical studies.
PMID- 10673321
TI - Nicotinic acetylcholine receptor agonists promote survival and reduce apoptosis
of chick ciliary ganglion neurons.
AB - The abundance, diversity, and ubiquitous expression of neuronal nicotinic
acetylcholine receptors (AChRs) suggest that many are involved in functions other
than synaptic transmission. We now report that a major AChR class promotes
neuronal survival. The 10-day survival of ciliary ganglion neurons in basal
culture medium (MEM) was approximately 35%, but increased to approximately 75% in
MEM containing nicotine (MEM/Nic) or carbachol, an effect similar to that
achieved by chronic depolarization with KCl. Pharmacological experiments revealed
that agonist-enhanced survival requires activation of AChRs sensitive to alpha
bungarotoxin (alphaBgt). alphaBgt-AChRs partly support neuronal survival by
limiting apoptosis since fewer apoptotic neurons were observed in MEM/Nic
compared to MEM. Moreover, nicotinic survival support was not further enhanced by
fibroblast growth factor, as seen for KCl, but increased to 100% by adding PACAP,
a trophic neuropeptide present in the ganglion. These results indicate that
alphaBgt-AChR activation regulates neuronal survival and suggest a mechanism
involving reduced apoptosis and interaction with an endogenous neuropeptide
growth factor.
PMID- 10673322
TI - Eph receptors and ephrin expression in cranial motor neurons and the branchial
arches of the chick embryo.
AB - Cranial motor axons navigate along a variety of pathways to their targets in the
periphery of the head. Whereas somatic motor axons innervate tongue and eye
muscles, visceral motor axons innervate parasympathetic ganglia, and
branchiomotor axons innervate the branchial arches. The formation of these
diverse pathways must depend upon molecules present in the environment traversed
by growing axons. We have analyzed the potential roles of the ephrin ligands and
their Eph tyrosine kinase receptors during cranial motor neuron development and
axon pathfinding, by investigating expression patterns of these molecules at
relevant stages in the chick. We detected expression of EphA3 and EphA4 among
trigeminal and facial motor neurons, at times when these neurons are projecting
to their muscle targets in the branchial arches. Corresponding ephrin-A ligands
for these receptors were found to be expressed in specific regions of the arches
during the same period, implicating ephrin-mediated interactions in cranial motor
axon pathfinding.
PMID- 10673323
TI - Sema3C and netrin-1 differentially affect axon growth in the hippocampal
formation.
AB - The interaction between outgrowing neurons and their targets is a central element
in the development of the afferent and efferent connections of the hippocampal
system. This requires that axonal growth cones recognize specific guidance cues
in the appropriate target area. At present, little is known about the mechanisms
that determine the lamina-specific termination of hippocampal afferents. In order
to understand the role of different guidance factors, we analyzed the effects of
Sema3C and Netrin-1 on explants from the entorhinal cortex, dentate gyrus, cornu
ammonis regions CA1 and CA3 and medial septum in a collagen coculture assay. Our
observations suggest that both semaphorins and netrin play important roles in the
neuron-target interactions in the hippocampal system. Sema3C is involved in the
control of the ingrowth of the septohippocampal projection. We also show that
netrin-1 is involved in attracting commissural neurons from dentate gyrus/hilus
and CA3 to their target area in the contralateral hippocampus.
PMID- 10673324
TI - Inhibition of PKB/Akt1 by C2-ceramide involves activation of ceramide-activated
protein phosphatase in PC12 cells.
AB - Accumulation of ceramide has been reported in stress- and receptor-induced
apoptosis in the nervous system. However, its role in apoptosis signaling remains
elusive. We describe here the inhibition of the NGF-activated phosphoinositide 3
kinase (PI3K)-PKB/Akt1 survival pathway by the cell permeable analog C2-ceramide.
C2-ceramide did not inhibit ERK, PI3K, or PDK1 activities and did not alter the
translocation of PDK1 and Akt1 to the plasma membrane, but blocked nuclear
translocation of Akt1. Down-regulation of the Akt pathway was due to enhanced
dephosphorylation of Akt1 at residues T308 and S473. Moreover, Akt1 was
dephosphorylated in vitro by a cation-independent phosphatase involving ceramide
activated protein phosphatase (CAPP). Membrane-anchored Akt1 was more resistant
to dephosphorylation/inactivation by C2-ceramide than wild-type Akt1.
Consistently, N-myristylated-Akt1 conferred resistance to the apoptosis induced
by C2-ceramide in PC12 cells. These results provide a novel mechanism for
induction of apoptosis by ceramide in nerve-derived cells.
PMID- 10673325
TI - Activating transcription factor 3 (ATF3) induction by axotomy in sensory and
motoneurons: A novel neuronal marker of nerve injury.
AB - Activating transcription factor 3 (ATF3), a member of ATF/CREB family of
transcription factors, is induced in a variety of stressed tissue. ATF3 regulates
transcription by binding to DNA sites as a homodimer or heterodimer with Jun
proteins. The purpose of this study was to examine the expression and regulation
of ATF3 after axonal injury in neurons in dorsal root ganglia (DRG) and spinal
cord. In naive rats, ATF3 was not expressed in the DRG and spinal cord. Following
the cut of peripheral nerve, ATF3 was immediately induced in virtually all DRG
neurons and motoneurons that were axotomized, and the time course of induction
was dependent on the distance between the injury site and the cell body. Double
labeling using immunohistochemistry revealed that the population of DRG neurons
expressing ATF3 included those expressing c-jun, and in motoneurons ATF3 and c
jun were concurrently expressed after axotomy. In contrast to c-jun, ATF3 was not
induced transsynaptically in spinal dorsal horn neurons. We conclude that ATF3 is
specifically induced in sensory and motoneurons in the spinal cord following
nerve injury and should be regarded as an unique neuronal marker of nerve injury
in the nervous system.
PMID- 10673326
TI - Agrin binds to beta-amyloid (Abeta), accelerates abeta fibril formation, and is
localized to Abeta deposits in Alzheimer's disease brain.
AB - Agrin is an extracellular matrix heparan sulfate proteoglycan (HSPG) well known
for its role in modulation of the neuromuscular junction during development.
Although agrin is one of the major HSPGs of the brain, its function there remains
elusive. Here we provide evidence suggesting a possible function for agrin in
Alzheimer's disease brain. Agrin protein binds the amyloidogenic peptide Abeta (1
40) in its fibrillar state via a mechanism that involves the heparan sulfate
glycosaminoglycan chains of agrin. Furthermore, agrin is able to accelerate Abeta
fibril formation and protect Abeta (1-40) from proteolysis, in vitro. Supporting
a biological significance for these in vitro data, immunocytochemical studies
demonstrate agrin's presence within senile plaques and cerebrovascular amyloid
deposits, and agrin immunostained capillaries exhibit pathological alterations in
AD brain. These data therefore suggest that agrin may be an important factor in
the progression of Abeta peptide aggregation and/or its persistence in
Alzheimer's disease brain.
PMID- 10673327
TI - In vivo protection of nigral dopamine neurons by lentiviral gene transfer of the
novel GDNF-family member neublastin/artemin.
AB - The glial cell line-derived neurotrophic factor (GDNF)-family of neurotrophic
factors consisted until recently of three members, GDNF, neurturin, and
persephin. We describe here the cloning of a new GDNF-family member, neublastin
(NBN), identical to artemin (ART), recently published (Baloh et al., 1998).
Addition of NBN/ART to cultures of fetal mesencephalic dopamine (DA) neurons
increased the number of surviving tyrosine hydroxylase (TH)-immunoreactive
neurons by approximately 70%, similar to the maximal effect obtained with GDNF.
To investigate the neuroprotective effects in vivo, lentiviral vectors carrying
the cDNA for NBN/ART or GDNF were injected into the striatum and ventral
midbrain. Three weeks after an intrastriatal 6-hydroxydopamine lesion only about
20% of the nigral DA neurons were left in the control group, while 80-90% of the
DA neurons remained in the NBN/ART and GDNF treatment groups, and the striatal TH
immunoreactive innervation was partly spared. We conclude that NBN/ART, similarly
to GDNF, is a potent neuroprotective factor for the nigrostriatal DA neurons in
vivo.
PMID- 10673328
TI - Hemizygosity of delta-catenin (CTNND2) is associated with severe mental
retardation in cri-du-chat syndrome.
AB - Delta-catenin is an adherens junction protein involved in cell motility and
expressed early in neuronal development. It was discovered as an interactor with
presenilin-1. The genomic structure of the human delta-catenin gene (Human Gene
Nomenclature Committee-approved symbol CTNND2) was determined and mapped to
5p15.2. A deletion of this chromosomal region has been associated with the cri-du
chat syndrome (CDCS), a segmental aneusomy syndrome of 5p that is associated with
an unusual high-pitched cry at birth, facial dysmorphology, poor growth, and
severe mental retardation. delta-catenin maps to a specific region in 5p15.2 that
has been implicated in the mental retardation phenotype. The breakpoints in
patients with 5p terminal deletions were characterized with respect to the
severity of mental retardation and the physical location of the delta-catenin
gene. A strong correlation was found between the hemizygous loss of delta-catenin
and severe mental retardation. These findings and the properties of delta-catenin
as a neuronal-specific protein, expressed early in development and involved in
cell motility, support its role in the mental retardation of CDCS when present in
only one copy.
PMID- 10673329
TI - Genomic and expression analyses of alternatively spliced transcripts of the MLL
septin-like fusion gene (MSF) that map to a 17q25 region of loss in breast and
ovarian tumors.
AB - We previously defined a common region of 17q25 loss in breast and ovarian tumors,
suggesting localization of at least one putative tumor suppressor gene. Genomic
clones from the interval were used to isolate candidate transcripts. One novel
transcript had strong homology to a septin family of GTPase genes involved in
cytokinesis. This gene was recently identified as a myeloid/lymphoid leukemia
(MLL) fusion protein partner in acute myeloid leukemia and was named MSF (MLL
septin-like fusion). As this gene may play roles in both leukemogenesis and
tumorigenesis, it is essential to understand its structure and normal expression.
We cloned two human alternative transcripts and identified a third database
variant of MSF. RNA expression studies with a probe common to the three novel
sequences showed differential expression of 4.0- and 3.0-kb transcripts in all
adult and fetal tissues tested. A probe spanning sequence unique to one MSF
variant detected specific expression of the 4.0-kb transcript in all tissues.
Another probe unique to a different MSF variant detected a 4.0-kb transcript only
in skeletal muscle. Proteins of 422 and 586 amino acids were predicted from the
novel alternate transcripts and included both a xylose isomerase 1 domain and a
GTPase domain. Nine common exons, three alternatively spliced exons, and six
polymorphisms were identified.
PMID- 10673330
TI - The alpha-fetoprotein promoter is the target of Afr1-mediated postnatal
repression.
AB - The alpha-fetoprotein (AFP) gene is transcribed at high levels in the fetal liver
and is repressed at birth, leading to low but detectable levels of AFP mRNA in
the adult liver. This repression is regulated, in part, by a locus that is
unlinked to AFP called Alpha-fetoprotein regulator 1 (Afr1). Previous studies
showed that Afr1 regulation is independent of the AFP enhancers but requires the
1-kb AFP promoter/repressor region. Here, we demonstrate that a transgene with
the 250-bp AFP promoter region linked to AFP enhancer element EII is expressed in
the fetal liver and is postnatally repressed. In addition, this transgene is
regulated by Afr1. These data indicate that the promoter is involved in postnatal
AFP repression. Furthermore, we provide a high-resolution map of the Afr1 locus
on mouse chromosome 15.
PMID- 10673331
TI - PEX7 gene structure, alternative transcripts, and evidence for a founder
haplotype for the frequent RCDP allele, L292ter.
AB - We recently reported cloning a cDNA encoding Pex7p, the peroxisomal PTS2
receptor. PEX7 mutations cause the peroxisome biogenesis disorder (PBD)
rhizomelic chondrodysplasia punctata (RCDP). In a survey of 44 RCDP probands, we
found that one PEX7 allele, L292ter, accounted for 50% of mutant PEX7 genes. Here
we report the characterization of the PEX7 structural gene, which spans 102 kb on
chromosome 6q21-q22.2 and contains at least 10 exons. In addition to the
predominant full-length transcript, we identified eight smaller PEX7 transcripts
generated by alternative exon splicing in several tissues. However, none of these
splice forms was able to restore PTS2 protein import into peroxisomes when
expressed in RCDP fibroblasts nor did they inhibit PTS2 protein import when
expressed in normal fibroblasts. To determine whether the high frequency of the
L292ter allele is due to a founder effect, we identified five polymorphic markers
(four diallelic markers and one CA repeat) spanning the PEX7 gene. We show that
all 12 L292ter homozygotes in our patient sample have an identical haplotype at
these five sites, consistent with the hypothesis that the L292ter mutation arose
once on an ancestral chromosome in the Caucasian population.
PMID- 10673332
TI - Identification of a murine locus conveying susceptibility to cadmium-induced
forelimb malformations.
AB - The heavy metal cadmium (Cd), an environmentally ubiquitous contaminant, is a
potent teratogen in mice. When administered parenterally, it induces an array of
malformations that vary in scope and severity with the route, dose, time of
administration, and the strain of the animal. When administered intraperitoneally
on day 9.0 of gestation, 4 mg/kg cadmium chloride produces forelimb defects
(predominantly ectrodactyly) in over 80% of fetuses of the C57BL/6 mouse strain,
while no limb defects are observed in the identically treated SWV strain. Like
other examples of strain-specific teratogenic activity, the underlying nature of
the differential susceptibility remains unknown. The present study investigates
the segregation of sensitivity to Cd-induced forelimb defects in crosses between
C57BL/6 and SWV mice and provides evidence for the involvement of both maternal
and fetal factors in the determination of defect expression. In addition,
quantitative trait loci (QTL) analysis of the fetal genetic component was
performed among 198 backcross progeny, utilizing a genomic linkage map of 149
informative microsatellite markers. One QTL demonstrating significant linkage to
expression of the defect, designated Cadfar (cadmium-induced forelimb autopod
reduction), was mapped to the distal end of chromosome 6 with a lod score of 3.1.
PMID- 10673333
TI - An integrated genetic linkage map with 1,137 markers constructed from five F2
crosses of autoimmune disease-prone and -resistant inbred rat strains.
AB - The rat (Rattus norvegicus) is an important experimental model for many human
diseases including arthritis, diabetes, and other autoimmune and chronic
inflammatory diseases. The rat genetic linkage map, however, is less well
developed than those of mouse and human. Integrated rat genetic linkage maps have
been previously reported by Pravenec et al. (1996, Mamm. Genome 7: 117-127) (500
markers mapped in one cross), Bihoreau et al. (1997, Genome Res. 7: 434-440) (767
markers mapped in three crosses), Wei et al. (1998, Mamm. Genome 9: 1002-1007)
(562 markers mapped in two crosses), Brown et al. (1998, Mamm. Genome 9: 521-530)
(678 markers mapped in four crosses), and Nordquist et al. (1999, Rat Genome 5:
15-20) (330 markers mapped in two crosses). The densest linkage map combined with
a radiation hybrid map, reported by Steen et al. (1999, Genome Res. 9: AP1-AP8),
includes 4736 markers mapped in two crosses. Here, we present an integrated
linkage map with 1137 markers. We have constructed this map by genotyping F2
progeny of five crosses: F344/NHsd x LEW/NHsd (673 markers), DA/Bkl x F344/NHsd
(531 markers), BN/SsN x LEW/N (714 markers), DA/Bkl x BN/SsNHsd (194 markers),
and DA/Bkl x ACI/SegHsd (245 markers). These inbred rat strains vary in
susceptibility/resistance to multiple autoimmune diseases and are used
extensively for many types of investigation. The integrated map includes 360 loci
mapped in three or more crosses. The map contains 196 new SSLP markers developed
by our group, as well as many SSLP markers developed by other groups. Two hundred
forty genes are incorporated in the map. This integrated map should allow
comparison of rat genetic maps from different groups and thereby facilitate
genetic studies of rat autoimmune and related disease models.
PMID- 10673334
TI - Sequence, structure, and evolution of a complete human olfactory receptor gene
cluster.
AB - The olfactory receptor (OR) gene cluster on human chromosome 17p13.3 was
subjected to mixed shotgun automated DNA sequencing. The resulting 412 kb of
genomic sequence include 17 OR coding regions, 6 of which are pseudogenes. Six of
the coding regions were discovered only upon genomic sequencing, while the others
were previously reported as partial sequences. A comparison of DNA sequences in
the vicinity of the OR coding regions revealed a common gene structure with an
intronless coding region and at least one upstream noncoding exon. Potential gene
control regions including specific pyrimidine:purine tracts and Olf-1 sites have
been identified. One of the pseudogenes apparently has evolved into a CpG island.
Four extensive CpG islands can be discerned within the cluster, not coupled to
specific OR genes. The cluster is flanked at its telomeric end by an unidentified
open reading frame (C17orf2) with no significant similarity to any known protein.
A high proportion of the cluster sequence (about 60%) belongs to various families
of interspersed repetitive elements, with a clear predominance of LINE repeats.
The OR genes in the cluster belong to two families and seven subfamilies, which
show a relatively high degree of intermixing along the cluster, in seemingly
random orientations. This genomic organization may be best accounted for by a
complex series of evolutionary events.
PMID- 10673335
TI - Molecular cloning of a novel apoptosis-related gene, human Nap1 (NCKAP1), and its
possible relation to Alzheimer disease.
AB - Expression profiles of thousands of genes (cDNAs) were analyzed in sporadic
Alzheimer disease (AD)-affected brains in comparison with normal subjects by
using the high-density cDNA filter method and differential display analysis.
Among 31 differentially expressed genes, one gene was found to be markedly
depressed in AD-affected brains. A full-length (or nearly full-length) cDNA of
the gene was isolated and sequenced. The cDNA turned out to be an orthologue of
rat Nap1. The gene was thus designated human Nap1 (HGMW-approved symbol NCKAP1)
and was mapped to human chromosome 2q32 by fluorescence in situ hybridization.
Northern blotting and in situ hybridization studies showed that in brain, the
gene is predominantly expressed in neuronal cells. Antisense oligo DNA of human
Nap1 transcripts was found to induce apoptosis of neuronal cells. Based on these
results, the possible role of human Nap1 in AD is discussed.
PMID- 10673336
TI - EHD2, EHD3, and EHD4 encode novel members of a highly conserved family of EH
domain-containing proteins.
AB - Exon trapping from a bacterial artificial chromosome (BAC 78138) mapping to the
19q13.3 glioma tumor suppressor candidate region yielded two exons that
recognized a 3.6-kb transcript on Northern blot. Screening of a human fetal brain
cDNA library with these exons identified three novel genes, designated EHD2,
EHD3, and EHD4, which are homologous to the recently characterized human EHD1
(testilin/HPAST) and its mouse homolog Ehd1, as well as to homologs in Drosophila
(Past1) and Caenorhabditis elegans. Alignment of the predicted peptide sequences
revealed striking similarities, with multiple conserved regions that include a
nucleotide-binding consensus site at the N-terminus, a bipartite nuclear
localization signal, and an eps15 homology (EH) protein-binding domain with an EF
hand motif at the C-terminus. The genes are specifically expressed, with EHD2
highly expressed in heart, EHD3 in brain and heart, and EHD4 in heart and
pancreas. EHD2 was confirmed to originate from BAC 78138 at 19q13.3; radiation
hybrid mapping localized EHD3 and EHD4 to 2p21 and 15q11.1, respectively; EHD1
has been previously mapped to 11q13. The three EHD1 paralogs therefore represent
novel members of a family of human EH domain-containing proteins that may play a
role in endocytosis and signaling. Mutation analysis of the five coding exons of
EHD2 in gliomas failed to detect any tumor-specific alterations, thus indicating
that EHD2 is an unlikely candidate for the 19q tumor suppressor gene.
PMID- 10673337
TI - Structure, expression, and chromosome mapping of LATS2, a mammalian homologue of
the Drosophila tumor suppressor gene lats/warts.
AB - We have cloned and characterized LATS2, a novel mammalian homologue of the
Drosophila tumor suppressor gene lats/warts. Northern blot analysis showed
ubiquitous expression of mouse LATS2 (MmLATS2) mRNA, whereas expression of human
LATS2 (HsLATS2) mRNA was enhanced in skeletal muscle and heart. Immunoblotting
analysis of fractionated cell lysates showed HsLats2 to be a nuclear protein. We
mapped the MmLATS2 gene to mouse chromosome 14 by interspecific backcross
analysis. We also mapped the HsLATS2 gene (by fluorescence in situ hybridization)
to the 13q11-q12 region, in which a loss of heterozygosity has been frequently
observed in many primary cancers and to which the tumor suppressor genes RB and
BRCA2 have also been mapped.
PMID- 10673338
TI - Genetic refinement and physical mapping of the CMT4B gene on chromosome 11q22.
AB - Charcot-Marie-Tooth disease type 4B (CMT4B) is a demyelinating autosomal
recessive motor and sensory neuropathy characterized by focally folded myelin
sheaths in the peripheral nerve. We recently mapped the CMT4B gene to a 5-cM
interval on chromosome 11q22, using homozygosity mapping and haplotype sharing
analysis on a large inbred pedigree. In the present study, we report the
construction of a YAC-based transcript map across the 5-cM critical region,
including 26 YACs, 35 STSs, and 52 ESTs. Furthermore, using 15 additional
physically ordered microsatellite markers from the 11q22 region on the original
inbred family, we were able to narrow the critical interval for the gene to 2 Mb,
which is now flanked by markers D11S1757 and CHLC-GATA3B05. Finally, after
computer analysis of the 33 ESTs assigned to the 2-Mb interval, we demonstrated
that 21 different transcripts as well as 3 known genes might represent potential
candidates for the disease.
PMID- 10673339
TI - Cloning, characterization, and chromosomal localization of Pnck, a
Ca(2+)/calmodulin-dependent protein kinase.
AB - Calcium is an important second messenger in eukaryotic cells. Many of the effects
of calcium are mediated via its interaction with calmodulin and the subsequent
activation of Ca(2+)/calmodulin-dependent (CaM) kinases. CaM kinases are involved
in a wide variety of cellular processes including muscle contraction,
neurotransmitter release, cell cycle control, and transcriptional regulation.
While CaMKII has been implicated in learning and memory, the biological role of
the other multifunctional CaM kinases, CaMKI and CaMKIV, is largely unknown. In
the course of a degenerate RT-PCR protein kinase screen, we identified a novel
serine/threonine kinase, Pnck. In this report, we describe the cloning,
chromosomal localization, and expression of Pnck, which encodes a 38-kDa protein
kinase whose catalytic domain shares 45-70% identity with members of the CaM
kinase family. The gene for Pnck localizes to mouse chromosome X, in a region of
conserved synteny with human chromosome Xq28 that is associated with multiple
distinct mental retardation syndromes. Pnck is upregulated during intermediate
and late stages of murine fetal development with highest levels of expression in
developing brain, bone, and gut. Pnck is also expressed in a tissue-specific
manner in adult mice with highest levels of expression detected in brain, uterus,
ovary, and testis. Interestingly, Pnck expression in these tissues is restricted
to particular compartments and appears to be further restricted to subsets of
cells within those compartments. The chromosomal localization of Pnck, along with
its tissue-specific and restricted pattern of spatial expression during
development, suggests that Pnck may be involved in a variety of developmental
processes including development of the central nervous system.
PMID- 10673340
TI - Isolation and characterization of a novel human paired-like homeodomain
containing transcription factor gene, VSX1, expressed in ocular tissues.
AB - Homeodomain transcription factors control cell fates during the development of
all animals. The paired-like subfamily of homeodomain proteins has been
particularly implicated in ocular development in different species. In this paper
we report the cDNA sequence, genomic structure, localization, and expression data
of a novel paired-like homeobox-containing gene, VSX1, isolated from a human
embryonic craniofacial cDNA library using the degenerate-PCR approach. The
composed VSX1 cDNA sequence of 1433 bp was predicted to encode a protein of 365
amino acid residues. Maximal homology at the protein level was identified with
the paired-like homeoproteins of the CVC-domain family: 92-97% identity was seen
in the homeodomain region with 55% overall identity to zebrafish and goldfish
Vsx1 and 35% overall identity to goldfish Vsx2 and murine Chx10. The gene was
found to consist of five exons that are distributed over 6.2 kb of genomic
sequence. VSX1 was localized to the 20p11-q11 region, which is homologous with
the distal part of mouse chromosome 2. Expression of VSX1 was detected in
embryonic craniofacial and adult ocular tissues. Several ocular phenotypes have
been mapped to the VSX1 region in both human and mouse genomes, and its candidacy
for these disorders is discussed.
PMID- 10673341
TI - Structure, expression, and chromosomal localization of the mouse Atox1 gene.
AB - Copper trafficking in eukaryotes involves small proteins termed
metallochaperones, which mediate copper delivery to specific intracellular sites.
Previous studies in yeast and human cell lines have suggested that Atox1 plays a
critical role in copper delivery to the secretory pathway. In the present study,
a mouse Atox1 (mAtox1) cDNA was cloned and shown to encode an open reading frame
with 85% amino acid identity to human Atox1. RNA blot analysis revealed that
mAtox1 was expressed as a single transcript in multiple tissues, and
immunoblotting indicated that the relative abundance of mAtox1 mRNA directly
correlated with mAtox1 protein. Analysis of the mAtox1 gene locus revealed a
genomic structure with four exons encompassing a total of 14.5 kb. RFLP and
haplotype analyses indicated that the mAtox1 locus was tightly linked to the Trhr
and D15Bir7 loci on mouse chromosome 15. Taken together, these data reveal marked
evolutionary conservation of Atox1 structure and provide a genomic organization
and localization that will aid in the genetic deciphering of the molecular role
of this protein in copper homeostasis.
PMID- 10673342
TI - Litomosoides sigmodontis: dynamics of the survival of microfilariae in resistant
and susceptible strains of mice.
AB - Litomosoides sigmodontis in the BALB/c mouse is the only model of filariasis
which allows the observation of the complete development in an immunocompetent
mouse. In this study, we injected microfilariae (mf) intravenously, as well as
into the pleural cavity, the site of natural release of mf from adult female
worms, and followed the kinetics of elimination within the host. In susceptible
BALB/c mice, mf circulated at high levels in the blood. In contrast, in C57BL/6
mice, which are refractory to full development, mf were eliminated rapidly from
the peripheral blood. However, 6 days after intrapleural injection, viable larvae
could be found in the pleural cavity and lung capillaries of both susceptible and
resistant strains. The numbers of mf in the pleural cavity and lung capillaries
in individual mice were significantly correlated, but not dependent on strain or
peripheral microfilaraemia. Thus, although C57BL/6 mice showed enhanced
production of nitric oxide by pleural exudate cells and a faster change in the
numbers of circulating leukocytes after injection, rapid killing of mf by cell or
nitric oxide-mediated mechanisms were not the reason for the different outcome.
Furthermore, 3 h after iv injection, only a small percentage of mf could be
recovered from the peripheral circulation, indicating the presence of a reservoir
for mf containment. In conclusion, injected mf showed disparate dynamics of
persistence within susceptible and resistant hosts, which is similar to the
disparate outcome of natural infections with L. sigmodontis. This difference
became obvious within 1 day after injection. The lung capillary system plays
obviously a crucial part in regulation of microfilaremia. Our model also provides
a possible means to explain frequent cases of occult infections in human
filariasis.
PMID- 10673343
TI - Schistosoma mansoni: differential expression of cathepsins L1 and L2 suggests
discrete biological functions for each enzyme.
AB - Schistosoma mansoni cathepsins L1 (SmCL1) and L2 (SmCL2) were expressed as active
recombinant proteinases in Saccharomyces cerevisiae. The recombinant enzymes
exhibited substrate preferences characteristic of cathepsin-L-like cysteine
proteinases. However, the enzymes differed in their substrate specificities;
SmCL1 cleaved Boc-Val-Leu-Lys-NHMec with a higher efficiency than it cleaved Z
Phe-Arg-NHMec, whereas the opposite was true for SmCL2. The enzymes also differed
in their pH profiles of activity; SmCL1 exhibited a broad pH profile with an
optimum of pH 6. 5, while SmCL2 was active only in the acidic pH range with an
optimum of 5.35. Immunoblot and RT-PCR analyses revealed that the native forms of
both SmCL1 and SmCL2 are expressed in male and female worms, but at higher levels
in adult female compared to male schistosomes. Additionally, both enzymes were
observed in the excretory/secretory products of adult worms. The RT-PCR analysis
indicated that neither enzyme is expressed in S. mansoni eggs or in miracidia,
suggesting that the cathepsin-L-like activity that has been previously reported
to be expressed in these stages may be the product of another gene(s). Cercariae
do not express SmCL2, but appear to express SmCL1 in its inactive precursor form.
Together with the findings of previous immunolocalization and phylogenetic
analyses, the results reported here demonstrate that SmCL1 and SmCL2 are distinct
cathepsin cysteine proteinases and strongly suggest that they play discrete
biological roles.
PMID- 10673344
TI - Trypanosoma cruzi: the effect of nitric oxide synthesis inhibition on the CD4 T
cell response to the trans-sialidase superfamily.
AB - During Trypanosoma cruzi infection the trans-sialidase superfamily stimulates the
development of a large population of CD4 T lymphocytes that produces IFNgamma.
These CD4 T cells fail to proliferate when stimulated in vitro. Why they fail to
proliferate remains unclear. Nitric oxide is a critical component of the host
immune response against T. cruzi, and to determine if NO inhibits trans-sialidase
superfamily-specific proliferative responses, mice were fed either N(G)-nitro-L
arginine methylester (L-NAME), an inhibitor of inducible nitric oxide synthase
(iNOS), or N(G)-nitro-D-arginine methyl ester (D-NAME), an inactive analog of L
NAME. The L-NAME-fed mice had increased parasitemia and mortality compared to the
D-NAME-fed mice. Following stimulation with a T. cruzi trans-sialidase
superfamily protein, splenocytes from both groups of mice failed to proliferate
but continued to make similar amounts of IFNgamma, suggesting that the
development of the trans-sialidase superfamily-specific CD4 response was not
affected by iNOS inhibition. In addition, IL-2 receptor (IL-2R) expression was
increased on T cells isolated from L-NAME-fed mice. These data suggest that
during T. cruzi infection NO causes downregulation of IL-2R expression, but does
not cause inhibition of trans-sialidase superfamily-specific CD4 T cell
proliferation. Rather, the trans-sialidase superfamily proliferation may be
inhibited by epitope variation.
PMID- 10673345
TI - Brugia malayi: localization of nitric oxide synthase in a lymphatic filariid.
AB - Nitric oxide synthase converts L-arginine to citrulline and nitric oxide, a
gaseous signaling molecule critical to multiple physiological responses. Nitric
oxide synthase was detected by Western blot analysis of Brugia malayi extracts
using an antibody raised against a peptide from murine brain nitric oxide
synthase. Using NADPH diaphorase staining and immunohistochemistry, nitric oxide
synthase was localized in the parasitic nematode B. malayi. As in Ascaris suum,
nitric oxide synthase was detected in the body wall muscles of adult B. malayi.
This localization pattern is in agreement with the role of nitric oxide in the
control of muscle tone in other invertebrates and in vertebrates. A novel finding
was the localization of nitric oxide synthase in the oocytes, in developing
embryos, and in spermatozoa. B. malayi nitric oxide synthase may play a role in
developmental signaling, as has been suggested for Drosophila and Ilyanassa, a
marine mud snail.
PMID- 10673346
TI - Fasciola hepatica: parasite-secreted proteinases degrade all human IgG
subclasses: determination of the specific cleavage sites and identification of
the immunoglobulin fragments produced.
AB - The study was focused on the relationship of Fasciola hepatica-secreted
proteinases and human IgG subclasses. Each IgG was incubated at different pH
values and lengths of time with either the adult parasite excretion-secretion
products or the purified cysteinyl proteinases cathepsin L1 and cathepsin L2. The
Ig fragments produced were isolated and characterized by Western blot analysis,
and the specific cleavage sites were determined by amino acid sequence analysis.
Parasite excretion-secretion products and both cathepsins L produced similar
degradation patterns and cleaved all human IgG subclasses at the hinge region,
yielding at pH 7.3 and 37 degrees C Fab and Fc fragments in the case of IgG1 and
IgG3 or Fab(2) and Fc in IgG2 and IgG4. While IgG1 and IgG3 were readily degraded
by E/S products either in the presence or in the absence of reducing agents, IgG2
and IgG4 were resistant to proteolysis and were only digested in the presence of
0.1 M dithiothreitol. The cathepsins L needed the presence of dithiothreitol to
digest IgG1, IgG2, and IgG4 whereas IgG3 was identically cleaved under both
reducing and nonreducing conditions. The main cleavage sites produced by E/S
products, CL1, or CL2 were located at the positions peptide bonds: His237-Thr238,
Glu237-Cys239, Gly233-Asp234, and Ser241-Cys242 for gamma1, gamma2, gamma3, or
gamma4, respectively. The enzymes gave additional splitting sites on the middle
hinge of IgG3 to produce shorter Fc fragments and also produce Fd degradation of
the IgG4. No cleavage specificity differences were found between CL1 and CL2, but
they differed in the kinetics of IgG3 degradation. By lowering the pH, only the
E/S products produced concomitant destruction of the Fc while preserving the Fab
portion. Under all the conditions assayed the enzymes produced an Fc'-like
fragment of 14-15 kDa corresponding to the whole CH3 domain of the
immunoglobulin. Contrary to the extensive degradation produced by cathepsins on
digested proteins, its actions on IgG subclasses were specific and restricted;
thus, all the fragments produced could be potentially involved in the mechanisms
used by the parasite to evade the host immune response.
PMID- 10673347
TI - Nitric oxide synthase and cGMP activity in the salivary glands of the American
dog tick Dermacentor variabilis.
AB - We colocalized nitric oxide synthase (NOS) activity in epithelial cells that
surround the salivary gland duct in female Dermacentor variabilis with NADPH
diaphorase histochemistry and immunohistochemistry using a polyclonal anti
endothelial NOS. Using size-exclusion chromatography, a fraction with a molecular
mass of about 185 kDa that had diaphorase activity was eluted from tick salivary
gland homogenate. This fraction converted arginine to citrulline with the
production of nitric oxide (NO), which was detected by using electron spin
resonance spectroscopy. The complete activity of the diaphorase fraction was
dependent on NADPH, FAD, tetrahydrobiopterin, calmodulin, (CaM), and Ca(2+), but
was not dependent on dithiothreitol. The arginine analog N(G)-monomethyl-L
arginine inhibited the activity of this fraction. NO and arginine activated
soluble guanylate cyclase to produce cGMP in dopamine-stimulated isolated
salivary glands. Dopamine-stimulated isolated salivary glands treated with tick
saline containing either EDTA, the NOS inhibitor N(G)-nitro-L-arginine methyl
ester, or the calcium/CaM binding inhibitor W-7 showed no increase in cGMP. The
NO donor sodium nitroprusside significantly increased cGMP levels in unstimulated
isolated salivary glands. A possible function for NO in salivation by this ixodid
tick is discussed.
PMID- 10673348
TI - Plasmodium falciparum: effective use of the CO(2)-NaHCO(3) buffer system for
evaluating chloroquine resistance.
PMID- 10673349
TI - Trichomonas vaginalis: detection of nucleoside hydrolase activity as a potential
screening procedure.
PMID- 10673350
TI - Trypanosoma cruzi: molecular cloning of a gene coding for a putative vacuolar
protein.
AB - We describe the characterization of Tc38, a Trypanosoma cruzi gene coding for a
337-amino-acid protein with a predicted molecular mass of 38 kDa. Tc38 presents
similarities to the plant storage vacuolar protein gamma-3-hordein involved in
the transport and targeting of prolamins to the vacuole of developing barley
endosperm. Western blot analysis using a polyclonal antiserum against recombinant
Tc38 revealed that the protein is differentially expressed in the different life
stages of the parasite, showing a higher expression in the epimastigote and
tripomastigote stages. Immunofluorescence studies suggest that the protein is
located in putative vacuolar structures in epimastigotes. The functionality of
this protein in T. cruzi remains to be elucidated.
PMID- 10673351
TI - Could Nef and Vpr proteins contribute to disease progression by promoting
depletion of bystander cells and prolonged survival of HIV-infected cells?
AB - A growing body of literature suggests that the HIV accessory proteins Nef and Vpr
could be involved in depletion of CD4(+) and non-CD4(+) cells and tissue atrophy,
and in delaying the death of HIV-infected cells. Cell depletion is likely to be
predominantly a bystander effect because the number of cells dying far outnumbers
HIV-infected cells and is not confined to CD4(+) cells. The myristylated N
terminal region of Nef has severe membrane disordering properties, and when
present in the extracellular medium causes rapid lysis in vitro of a wide range
of CD4(+) and non-CD4(+) cells, suggesting a role for extracellular Nef in the
depletion of bystander cells. A direct role for HIV-1 Nef in cytopathicity is
supported by studies in HIV-infected Hu Liv/Thy SCID mice, in transgenic mice
expressing nef gene alone, and in rhesus macaques infected with SIV/HIV chimeric
virus containing HIV-1 nef. The N-terminal region of Nef has been directly
implicated in development of simian AIDS. Extracellular Vpr and C-terminal
fragments of Vpr cause membrane permeabilization and apoptosis of a wide range of
CD4(+) and non-CD4(+) cells, and could also contribute to depletion of bystander
cells. A direct in vivo role for Vpr in thymocyte depletion, thymic atrophy, and
nephropathy is suggested in studies with vpr transgenic mice. Intracellular Nef
and Vpr could help HIV-infected cells evade cell death by inhibiting apoptosis of
infected cells and by avoiding virus-specific CTL response. Nef and Vpr are
potential targets for therapeutic intervention and vaccine development, and
strategies that prevent the death of bystander cells while promoting the early
death of HIV-infected cells could arrest or retard progression to AIDS.
PMID- 10673352
TI - Two peptides from CD23, including the inverse RGD sequence and its related
peptide, interact with the MHC class II molecule.
AB - The human CD23 molecule (low affinity receptor for IgE) has a C-type lectin
domain, a reversed Arg-Gly-Asp (RGD) sequence near the C-terminus, and an "RGD
binding inhibitory peptide" at the root of the N-sugar chain. Three peptides were
synthesized to determine their functions, i.e., #1, including an inverse RGD
sequence near the C-terminus; #2, RGD-binding inhibitory peptides in the gpIIIa
chain of platelet integrin gpIIb/IIIa; and #3, the inverse sequence located at
the root of the N-sugar chain of CD23 which has homology to peptide 2. Among the
three peptide, only peptide 3 inhibited aggregation of L-KT9 cells. Isotope
labeled peptides 1 and 3 bound to MHC class II molecules but peptide 1 did not
bind to CD23 molecules. Peptide 3 showed a higher affinity to MHC class II than
did peptide 1. Both peptides in CD23, therefore, seem to have interesting and
important functions in relation to MHC class II molecules and also to CD23
molecules when CD23 on EBV-transformed B cells acts as a lectin in homotypic cell
aggregation. The physiological function of CD23 was discussed from an evolutional
point of view.
PMID- 10673353
TI - Interferon-alpha signaling promotes nucleus-to-cytoplasmic redistribution of
p95Vav, and formation of a multisubunit complex involving Vav, Ku80, and Tyk2.
AB - Interferons (IFNs) are a family of hormone-like secretory proteins with multiple
phenotypical changes, including gene expression and morphological alterations.
Earlier studies have shown that IFN-activated Tyk2 kinase physical associates
with p95Vav (Vav), a proto-oncogene gene product expressed in hematopoietic
cells. Since Tyk2 is a cytoplasmic kinase and Vav is believed to be localized in
the nuclear compartment, here we explored the possibility of Vav redistribution
in IFN-alpha-activated cells, using the U266 human myeloma cell line as a model
system. Using biochemical assays and in situ confocal microscopy, we demonstrate
that IFN-alpha treatment triggers a rapid (10 min) translocation of Vav from the
nuclear compartment to the cytoplasm. In addition, we also show the existence of
IFN-alpha-induced physical interaction between Vav and Ku80, Ku80, and Tyk2, and
among Vav, Ku80, and Tyk2 in the cytoplasmic compartment of IFN-stimulated cells.
The observed IFN-alpha-induced association among Vav, Ku80, and Tyk2 was
dependent on cellular tyrosine kinase activity. Since recently Vav has been shown
to promote the GDP/GTP exchange activity of the cytoskeleton signaling molecule
small GTPase Rac1 and activates its downstream signaling, our present findings
raise the possibility of involvement of the small GTPase in IFN signaling leading
to its biological effects, including cytoskeleton reorganization.
PMID- 10673354
TI - CYRL, a novel cytokine receptor-like protein expressed in testis, lung, and
spleen.
AB - The interleukin-3 receptor is composed of a ligand-specific alpha subunit (IL
3Ralpha) and a beta subunit (beta(c) or beta(IL3)). Here we report the cloning of
a rat brain cDNA transcript with significant homology to IL-3Ralpha, which we
have termed CYRL, for CYtokine Receptor-Like protein. A number of conserved
motifs identify CYRL as a member of the alpha family of cytokine receptor
subunits, but the extracellular domain was too divergent from the mouse IL
3Ralpha sequence to suggest that CYRL is the rat ortholog of IL-3Ralpha. CYRL
mRNA expression by Northern blotting was highest in the testis, intermediate in
the lung, and modest in spleen, brain, and heart. Antibodies generated against
the extracellular domain of CYRL specifically labeled a broad immunoreactive band
of M(r) approximately 50,000 in membrane fractions of testis, lung, and spleen.
CYRL appears to be a novel cytokine receptor alpha-subunit of unknown function
and with no defined ligands.
PMID- 10673355
TI - Identification of the promoter region of human placental 6-phosphofructo-2
kinase/fructose-2,6-bisphosphatase gene.
AB - The placenta-type isozyme of human 6-phosphofructo-2-kinase/fructose-2,6
bisphosphatase (HP2K) is expressed in several tissues such as placenta, brain,
testis, liver, kidney, skeletal muscle, and primary blood mononuclear cells. To
better understand the regulation of HP2K gene expression, we isolated and
characterized its genomic DNA, which includes the promoter region. The results of
oligo-capping analysis indicate that the transcription start point (tsp) is an
adenine residue 329 bp upstream of the translational start codon. DNA sequence
analysis of this gene shows that the promoter region that contains the TATA box
sequence and the 5'-UTR is different from the other known PFK-2/F2, 6BPase genes.
In addition, its 5'-flanking and 5'-UTR both have G + C-rich sequences containing
Sp1 binding sites. To identify the promoter/enhancer region of HP2K gene, we
performed transfection analyses of human choriocarcinoma BeWo cells with HP2K
promoter-luciferase constructs. These experiments identified a promoter region
164 bp upstream from the tsp and an enhancer region between -1265 and -1329 on
the 5'-flanking sequences. We also showed that Sp1 sites were not essential for
HP2K transcription. Following transfection, stimulation experiments with serum,
progesterone and phorbol 12-myristate 13-acetate showed that only the construct
with the enhancer containing putative early growth response-1 binding motif was
responsive to serum. We propose that the transcription of HP2K is strictly
controlled by tissue-specific factors even though its genomic DNA contains
several transcriptional elements.
PMID- 10673356
TI - Direct interaction between emerin and lamin A.
AB - Emerin is the protein of the inner nuclear membrane that is affected by mutation
in X-linked Emery-Dreifuss muscular dystrophy. The autosomal dominant form of the
disease is caused by mutations in the lamin A/C gene. Several lines of
circumstantial evidence have suggested an interaction of emerin with lamins in
the nuclear lamina but direct interaction between the two proteins has not yet
been demonstrated. We now demonstrate direct interaction between recombinant
emerin and lamin A molecules using biomolecular interaction analysis (BIA) and
monoclonal antibodies. An emerin-lamin A interaction system may be related in
function to the LAP2-lamin B system at the inner nuclear rim.
PMID- 10673357
TI - A conditioning lesion promotes in vivo nerve regeneration in the contralateral
sciatic nerve of rats.
AB - A conditioning lesion in the sciatic nerve increases in vivo axonal regeneration
in the nerve after a second transection. We studied whether this increased
regeneration also occurs in the contralateral nerve. The left sciatic nerve was
transected and sutured in Wistar rats; the nerve was exposed but not transected
in controls. After 5 days, the right sciatic nerves of all rats were transected
and sutured. Neuronal regeneration was measured at 0, 1, 3, 5, and 7 days with
the pinch test and histological staining. IL-1beta and TGF-beta1 expression was
also measured. The initial delay in the experimental group was significantly
shorter, but the regeneration rates were the same. The expression of IL-1beta and
TGF-beta1 in the right dorsal root ganglia was significantly higher in the
experimental group. Nerve injury enhances cytokine expression in the
contralateral dorsal root ganglion and promotes contralateral nerve regeneration
in vivo by shortening the initial delay.
PMID- 10673358
TI - Internalization and processing of human angiogenin by cultured aortic smooth
muscle cells.
AB - Human angiogenin is a 14-kDa plasma protein with angiogenic and ribonucleolytic
activities. Angiogenin binds specifically to aortic smooth muscle cells,
activates second messenger pathways, and inhibits their proliferation. Human and
bovine aortic smooth muscle cells were used to study the internalization and
intracellular fate of human angiogenin at 37 degrees C. Using a specific antibody
against angiogenin, we found that the internalized native protein was localized
in the perinuclear region at 30 min and then dispersed throughout the cytoplasm.
In conditions favoring receptor-mediated endocytosis, internalization of
iodinated angiogenin showed a first peak at 5 min and then further increased for
up to 24 h. The half-life of the molecule, calculated as 12 h in chase
experiments, could contribute to its intracellular accumulation. In cell
extracts, in addition to the 14-kDa protein, a 8.7-kDa fragment was observed at
24 h, and three fragments with molecular mass of 10.5, 8.7, and 6. 1 kDa were
detected at 48 h. Our data point to a specific internalization and processing of
human angiogenin by aortic smooth muscle cells.
PMID- 10673359
TI - Tumor antigen HuR binds specifically to one of five protein-binding segments in
the 3'-untranslated region of the neurofibromin messenger RNA.
AB - 3'-untranslated regions of various mRNAs have been shown to contain sequence
motifs which control mRNA stability, translatability, and efficiency of
translation as well as intracellular localization. We aimed to identify protein
binding regions of the long and highly conserved 3'UTR of the mRNA coding for
neurofibromin, a well-known tumor suppressor protein, whose genetic deficiency
causes the autosomal dominant disease neurofibromatosis type 1 (NF1). We
discovered five RNA fragments that were able to undergo specific binding to
proteins from cell lysates (NF1-PBRs, NF1-protein-binding regions). Additionally
we identified the Elav-like protein HuR binding to NF1-PBR1. HuR interacts with
AU-rich elements in the 3'UTR of many protooncogenes, cytokines, and
transcription factors, thereby regulating the expression of these mRNAs on the
posttranscriptional level. Transfection assays with a CAT reporter construct
revealed reduced expression of the reporter, suggesting that HuR may be involved
in the fine-tuning of the expression of the NF1 gene.
PMID- 10673360
TI - Implication of novel biochemical property of beta-amyloid.
AB - Alzheimer disease (AD) is a heterogeneous disorder with a variety of molecular
pathologies converging predominantly on abnormal amyloid deposition particularly
in the brain. beta-Amyloid aggregation into senile plaques is one of the
pathological hallmarks of AD. beta-Amyloid is generated by a proteolytic cleavage
of a large membrane protein, amyloid precursor protein (APP). We have observed a
new property of beta-amyloid. The amyloid 1-42 beta fragment, when aggregated,
possesses proteolytic and esterase-like activity, in vitro. Three independent
methods were used to test the new property of beta-amyloid. While esterase
activity involves imidazole catalysis, proteolytic activity is consistent with
participation of a serine peptidase triad: catalytic Ser, His and Glu (or Asp).
Although the amino acid triad is a necessary requirement for the protease
reactivity, it is not sufficient since the secondary structure of the protein
significantly contributes to the proteolytic activity. The ability of beta
amyloid to cleave peptide or ester bonds could be thus responsible for either
inactivation of other proteins and/or APP proteolysis itself. This property may
be responsible for early pathogenesis of AD since there is emerging evidence that
non-plaque amyloid is elevated in Alzheimer patients.
PMID- 10673361
TI - Differential signaling pathways following oxidative stress in mutant myotonin
protein kinase cDNA-transfected C2C12 cell lines.
AB - We investigated the response to oxidative stress in a model system established in
C2C12 cells stably transfected with myotonin protein kinase (MtPK) cDNAs having
5, 46, 60, or 160 CTG repeats. The transformants showed CTG repeat number
dependent susceptibility to oxidative stress. Mutant MtPK cDNA transformants
containing 160 CTG repeats showed apoptotic cell death by the exposure to an
oxidant, a very low level of methylmercury. The addition of the antioxidant
Trolox protected transformants against apoptosis. Oxidative stress activated the
extracellular signal-regulated kinases (ERKs) pathway leading to cell survival in
wild-type MtPK cDNA transformants, whereas mutant MtPK cDNA transformants having
160 CTG repeats were defective in the induction of the ERK pathway, although the
activation of stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase
(JNK) was strong and sustained. These results suggest that the susceptibility to
oxidative stress in mutant MtPK cDNA transformants involves differential
signaling pathways evoked following oxidative stress.
PMID- 10673362
TI - Localization of exercise- and denervation-responsive elements in the mouse GLUT4
gene.
AB - Exercise training increases the expression of GLUT4 in skeletal muscle. Previous
studies demonstrated that the exercise-responsive element(s) of the murine GLUT4
gene are located between bases -1001 and -442 relative to the transcription start
site. To further characterize the regulatory elements in the GLUT4 gene, the
regulation of GLUT4 minigenes containing -701, -551, -442, or -423 bp of the 5'
flanking region was studied in transgenic mice. All minigenes studied showed
significant expression in skeletal muscle and heart, including the -423 GLUT4
minigene that lacked the myocyte enhancer factor 2 (MEF2)-binding domain (
CTAAAAATAG-) located between bases -437 and -428. The -701- and -551-bp
constructs were expressed in brown adipose tissues while the -442 and -423
constructs were not. In skeletal muscle, either swimming or treadmill running up
regulated GLUT4 minigene mRNA levels in -701 and -551 transgenic mice, but not in
the -442 and -423 transgenic mice. Denervation of the gastrocnemius muscle by
sectioning of the sciatic nerve down-regulated minigene and endogenous GLUT4
mRNAs in all -701, -551, -442, and -423 transgenic mice. These data indicate that
exercise-responsive element(s) and brown adipocyte specific element(s) are
located within 109 bp between bases -551 and -442 of the GLUT4 gene, but that the
cis-element for denervation-induced down-regulation of the GLUT4 gene is located
downstream of base -423. Finally, the MEF2 binding site between bases -437 and
428 is not necessary for expression of GLUT4 in skeletal muscles and heart; the
cis-element mediating this effect is also located downstream of base -423.
PMID- 10673363
TI - Hyperleptinemia in female patients with ossification of spinal ligaments.
AB - In order to examine the involvement of leptin in the ossification of spinal
ligaments (OSL), the present study examined (i) serum levels of leptin and
insulin in OSL patients and controls, (ii) serum leptin levels in children of OSL
females with severe obesity, (iii) the expression of leptin receptor mRNA in
human spinal ligaments, and (iv) effects of leptin on cultured human ligament
cells. In the OSL females, serum leptin levels were significantly higher than
those of the control females, and the levels were positively correlated to the
serum insulin levels, while in the control females, there was a tendency of
inverse correlation. The daughters of OSL females with severe obesity also had
high serum leptin levels, although they had not developed OSL. The expression of
leptin receptor mRNA was confirmed in the ligaments, but leptin did not influence
the alkaline phosphatase activity nor procollagen type I carboxyl-terminal
peptide content of the ligament cells. These findings suggest that leptin is
involved genetically and indirectly with the pathogenesis of OSL in female
patients.
PMID- 10673364
TI - Quantitative analysis of constitutive and inducible CYPs mRNA expression in the
HepG2 cell line using reverse transcription-competitive PCR.
AB - Drug interactions which affect drug metabolism are of clinical importance. It is,
however, difficult to estimate drug interactions in human from results obtained
in animal experiments. In our previous study, we demonstrated that a combination
of the HepG2 cell line and semiquantitative reverse transcription-PCR (RT-PCR)
could be used to evaluate the degree of CYP3A mRNA induction by various drugs.
Using an RT-competitive PCR (RT-cPCR) with beta-actin as the standard in this
study, the constitutive and rifampicin (RFP)-induced expression of CYP3A4,
CYP2C9, CYP2E1, and CYP1A2 mRNA in the HepG2 cells could be quantitatively and
reproducibly determined. 120 h-treatment of HepG2 cells with 50 micromol/l RFP
induced maximally 8.4- and 6.0-fold the expression of CYP3A4 and CYP2C9 mRNA,
respectively, in comparison with untreated cells. On the other hand, mRNA level
in CYP2E1 and CYP1A2 was not significantly changed by 50 micromol/l RFP after 24
to 120 h. To our knowledge, we report for the first time quantitative profiles of
CYPs mRNA in HepG2 cells. This study demonstrates the efficiency of a combination
of HepG2 cells and RT-cPCR in the evaluation of CYPs mRNA-induction by drugs.
PMID- 10673365
TI - Variants of NOS1, NOS2, and NOS3 genes in asthmatics.
AB - Nitric oxide (NO) gas concentrations are higher in expired air in asthmatics. NO
is synthesized by three isoforms of NO synthase (NOS) encoded by three distinct
genes, NOS1, NOS2, and NOS3. Genome-wide searches have identified linkages to
asthma on chromosomes 7, 12, and 17 where these three genes are localized. No
association study, however, has been reported to date. To test whether variants
of NOS1, NOS2, and NOS3 relate to asthma, a genetic association study was
conducted in a British population (n = 300). Intragenic microsatellite variants
of NOS1 were significantly associated with asthma [odds ratio (OR) = 2.08, 95%
CI: 1.20-3.57 (95% CI), P = 0.008 (Pc = 0.048)], but not with IgE levels. Neither
NOS2 nor NOS3 variants showed any association with asthma nor IgE levels. These
findings suggest that NOS1 variants may be a significant contributor to asthma in
a British population.
PMID- 10673366
TI - A regulated interaction between alpha5beta1 integrin and osteopontin.
AB - The extracellular matrix protein osteopontin (OPN) interacts with a number of
integrins, namely alphavbeta1, alphavbeta3, alphavbeta5, alpha9beta1,
alpha8beta1, and alpha4beta1. We have investigated the interaction of alpha5beta1
integrin with OPN using K562 cells, which only express alpha5beta1. alpha5beta1
is in a low activation state in this cell line, but can be stimulated to a higher
activation state by the phorbol ester TPA. Treating K562 wild-type cells (K562
WT) with TPA stimulated an interaction between alpha5beta1 and OPN. No
interaction was seen in the absence of TPA. alpha5beta1 selectively interacted
with a GST fusion protein of the N-terminal fragment of OPN (aa17-168), which is
generated in vivo by thrombin cleavage of OPN. Expression of the alpha4 integrin
in K562 cells (K562-alpha4beta1) stimulated alpha5beta1-dependent binding to aa17
168 in the absence of TPA, suggesting that alpha4beta1 activates alpha5beta1 in
K562 cells. Adhesion via alpha5beta1 is mediated by the Arg-Gly-Asp (RGD) motif
of OPN, as mutating this sequence to Arg-Ala-Asp (RAD) blocked binding of both
cell types. These data demonstrate that thrombin cleavage regulates the adhesive
properties of OPN and that alpha5beta1 integrin can interact with thrombin
cleaved osteopontin when in a high activation state.
PMID- 10673367
TI - Differential regulation of FGF-1 and -2 mitogenic activity is related to their
kinetics of binding to heparan sulfate in MDA-MB-231 human breast cancer cells.
AB - The growth of the malignant human mammary MDA-MB-231 cells is stimulated by
fibroblast growth factor-1 (FGF-1) but not by FGF-2. When these cells are
cultured in the presence of chlorate, an inhibitor of heparan sulfate (HS)
sulfation, their proliferation is stimulated by both FGF-1 and FGF-2. We analyzed
the interactions of FGF-1 and FGF-2 with HS purified from the cell layer and the
culture medium of control and chlorate-treated MDA-MB-231 cells. The HS from the
cell layer bound FGF-1 with faster association kinetics than the HS from the
culture medium, and so had a higher affinity for FGF-1. Chlorate treatment had no
significant effect on the FGF-1 binding kinetics of the HS. In contrast to FGF-1,
chlorate treatment of the cells significantly altered the FGF-2 binding kinetics.
The HS from untreated cells possessed two binding sites for FGF-2, one with fast
association kinetics (k(ass) 470,000 to 610,000 M(-1) s(-1)) and a high affinity
(K(d) 46 to 70 nM) and one with slower association kinetics (k(ass) 74,000 to
100,000 M(-1) s(-1)) and a lower affinity (K(d) 290 to 400 nM). HS from chlorate
treated cells possessed just a single binding site for FGF-2 with fast
association kinetics (k(ass) 270,000 to 290,000 M(-1) s(-1)) and a high affinity
(K(d) 41 to 57 nM). These results show that there is a relationship between the
binding kinetics of FGFs and their ability to stimulate cell growth.
PMID- 10673368
TI - A novel method for expression and large-scale production of human brain l
glutamate decarboxylase.
AB - l-Glutamate decarboxylase (GAD; EC 4.1.1.15) is the rate-limiting enzyme involved
in the synthesis of gamma-aminobutyric acid (GABA), the major inhibitory
neurotransmitter in the mammalian brain. Imbalance in the conversion of glutamate
to GABA has been implicated in a host of human diseases. Studies on the
structure, function, and therapeutic use of GAD have been precluded by
insufficient quantities of purified active enzyme. Here we report a novel
methodology for the expression and large-scale production of enzymatically
active, pure, recombinant human GAD65 and GAD67. This method circumvents the
sequestering of expressed protein into insoluble inclusion bodies and reduces
production of truncated proteins. The availability of sufficient quantities of
purified HGAD65 and HGAD67 has allowed for the production of specific polyclonal
antibodies that discriminate between the two isoforms. This methodology, in
addition to providing key human brain enzymes, may be generally applicable to
other systems.
PMID- 10673369
TI - Marked increase in membranolytic selectivity of novel cyclic tachyplesins
constrained with an antiparallel two-beta strand cystine knot framework.
AB - We have developed a highly constrained 18-residue cyclic peptide template based
on the antimicrobial peptide tachyplesin-1 that features an end-to-end peptide
backbone and a cystine knot-like motif with three evenly spaced disulfide bonds
to cross-brace the antiparallel beta-strands and to approximate an amphiphatic
"beta-tile"-like structure. Six beta-tile analogs were prepared to correlate
different topological patterns with membranolytic specificity. Their
conformations and antimicrobial and hemolytic activities were compared with
tachyplesin-1 and the recently discovered Rhesus monkey theta defensin (RTD)
which contains similar beta-tile structural elements. The beta-tile peptides and
RTD retained broad spectrum antimicrobial activities. In general, they were less
active than tachyplesin-1 in 10 tested organisms but their activity increased
under high-salt (100 mM NaCl) rather than in low-salt conditions. The beta-tile
peptides are highly nontoxic to human erythrocytes with EC(25) ranging from 600
to 4000 microM. Collectively, our results show that the design of a highly rigid
peptide template is useful for further analog study to dissociate antimicrobial
activity from cytotoxicity which would be helpful in discovering clinical
applications for peptide antibiotics.
PMID- 10673370
TI - Cathepsin Q, a novel lysosomal cysteine protease highly expressed in placenta.
AB - The complete nucleotide sequence of a novel cathepsin cDNA derived from rat
placenta was determined and is termed cathepsin Q. The predicted protein of 343
amino acid is a member of the family C1A protease related to cathepsin L. Rat
cathepsin Q and its mouse counterpart were found highly expressed in placenta,
whereas no detectable levels were found in lung, spleen, heart, brain, kidney,
thymus, testicle, liver, or embryonic tissues. It is predicted that cathepsin Q
will differ in catalytic specificity to another placental-specific protease,
cathepsin P, indicating that these enzymes will have unique proteolytic functions
in extra-embryonic tissues.
PMID- 10673371
TI - Human membrane type-2 matrix metalloproteinase is defective in cell-associated
activation of progelatinase A.
AB - Transfection of the mouse membrane type-2 matrix metalloproteinase (MT2-MMP) gene
into COS-1 cells resulted in activation of progelatinase A; however, that of the
human gene had no effect. Expression of human and mouse MT2-MMP chimeric proteins
revealed the defect of human MT2-MMP which resides in the region between amino
acid (aa) residues 155 and 271. Seven aa residues in this region were not
conserved between human and mouse MT2-MMP. Substitution with the corresponding
mouse residue, proline-183 to serine and glutamine-185 to aspartic acid,
recovered cell-associated progelatinase A activation function. These residues are
located in the insertion sequence-2 (IS-2), which was conserved in six clones of
the human MT2-MMP gene from different sources, except that of proline-183 which
was substituted with serine from HT1080 cells. These results indicate that human
MT2-MMP is defective in cell-associated activation of progelatinase A, and this
is attributed to IS-2. These findings emphasize the importance of IS-2 in MT2-MMP
functionality.
PMID- 10673372
TI - Up-regulation of endothelin-converting enzyme-1 in gastric mucosal inflammatory
responses to Helicobacter pylori lipopolysaccharide.
AB - Endothelin-1 (ET-1) is a vasoactive peptide produced from a biologically inactive
big ET-1 by the action of endothelin-converting enzyme-1 (ECE-1). We investigated
gastric mucosal expression of ECE-1 during a 10-day course of inflammatory
responses associated with acute gastritis elicited by Helicobacter pylori
lipopolysaccharide. The ECE-1 activity was associated with microsomal fraction
and the level of its expression reflected the extent of mucosal inflammatory
involvement. The histologic pattern of inflammation reached a maximum on the 4th
day following the lipopolysaccharide and was accompanied by a 4.1-fold
enhancement in the expression of ECE-1 activity and a significant elevation in ET
1 (3.1-fold), TNF-alpha (8.8-fold), and apoptosis (11.6-fold). A 41.5% decrease
in the severity of mucosal inflammation by the 10th day following the
lipopolysaccharide was reflected in a 62.3% reduction in the mucosal expression
of ECE-1 and a decline in TNF-alpha, ET-1, and apoptosis. Thus, H. pylori
infection causes up-regulation of gastric mucosal ECE-1 expression, which leads
to the enhancement of ET-1 production, induction of TNF-alpha, and triggering the
apoptotic events that exacerbate the inflammatory process.
PMID- 10673373
TI - Molecular cloning of neonate/infant-specific pepsinogens from rat stomach mucosa
and their expressional change during development.
AB - To clarify the nature of rat neonate/infant-specific pepsinogens, we carried out
their purification and molecular cloning. Prochymosin was found to be the major
neonatal pepsinogen. The general proteolytic activity of its active form,
chymosin, was, however, lower than those of pepsins A and C which are predominant
in adult animals. Molecular cloning of rat prochymosin cDNA was achieved along
with cDNA for another neonate-specific pepsinogen, pepsinogen F, although
determination of pepsinogen F in neonatal gastric mucosa was unsuccessful,
presumably due to its lack of proteolytic activity or different proteolytic
specificity. Northern blot analysis confirmed that genes for prochymosin and
pepsinogen F are expressed only at neonatal/infant stages and the switching of
gene expression to that of pepsinogen C occurred at late infant stages. A
phylogenetic tree based on nucleotide sequences showed clearly that pepsinogens
fall into four major groups, namely prochymosin and pepsinogen F of the
neonate/infant and pepsinogens A and C of adult animals. Although, to date,
prochymosin and pepsinogen F were believed to be expressed in only a limited
number of mammals, the present results suggest that they might be expressed at
the neonatal/infant stage in a variety of mammals.
PMID- 10673374
TI - Biochemical evidence for a 170-kilodalton, AF-2-dependent vitamin D
receptor/retinoid X receptor coactivator that is highly expressed in osteoblasts.
AB - Human vitamin D receptor (hVDR) fused to glutathione S-transferase was utilized
to detect a VDR-interacting protein (VIP) of approximately 170 kDa. VIP(170) is
expressed in osteoblast-like ROS 17/2.8 cells and, to a lesser extent, in COS-7
and HeLa cells. VIP(170) may be a coactivator because it interacts only with 1,25
dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) ligand-bound hVDR and because a mutation
(E420A) in the activation function-2 (AF-2) of hVDR abolishes both receptor
mediated transactivation and VIP(170) binding. Unlike L254G hVDR, a
heterodimerization mutant with an intact AF-2, the E420A mutant is only partially
attenuated in its association with the retinoid X receptor (RXR) DNA-binding
partner. Finally, the ability of overexpressed hVDR to squelch glucocorticoid
receptor-mediated transactivation is lost in both the L254G and E420A mutants.
These results suggest that several protein-protein interactions, including VDR
association with RXR and VIP(170), are required for stabilization of a multimeric
complex that transduces the signal for 1,25(OH)(2)D(3)-elicited transactivation.
PMID- 10673375
TI - Tyrosine phosphorylation of myelin P(0) and its implication in signal
transduction.
AB - P(0), a major structural protein of peripheral myelin, belongs to the
immunoglobulin superfamily. Sequence comparison of P(0) with PZR, a tyrosine
phosphatase SHP-2 binding protein we recently cloned, revealed the presence of an
immunoreceptor tyrosine-based inhibitory motif (ITIM) in the intracellular
portion of the P(0) molecule. To study the role of this putative ITIM in signal
transduction, we have expressed P(0) in HT-1080 and 293 cells. Stimulation of the
transfected cells with pervanadate, a powerful inhibitor of tyrosine
phosphatases, resulted in tyrosine phosphorylation of P(0) and its association
with several tyrosine-phosphorylated proteins. Mutation of Y(220) embedded in the
ITIM to phenylalanine abolished the tyrosine phosphorylation and the association.
Tyrosine phosphorylation of P(0) and its association with other signaling
proteins were also observed in pervanadate-treated RN22 Schwannoma cells, which
express endogenous P(0). Furthermore, injection of pervanadate induced tyrosine
phosphorylation of P(0) in peripheral nerves of newborn but not adult mice. The
physiological importance of the ITIM in P(0) is implied by the fact that a
naturally occurred P(0) mutant with a disrupted ITIM has a dominant role in
causing Dejerine-Scotts syndrome. Taken together, P(0) is phosphorylated on
Try(220). The presence of an ITIM in P(0) and its ability to mediate protein
protein interaction through tyrosine phosphorylation indicate that P(0) is not
merely a structural protein but may also be a crucial player in cell signaling.
PMID- 10673376
TI - The effect of apoptosis inhibitors on experimental autoimmune encephalomyelitis:
apoptosis as a regulatory factor.
AB - The effect of apoptosis inhibitors on experimental autoimmune encephalomyelitis
(EAE), a model for multiple sclerosis, was investigated by intraperitoneal or
intracisternal administration of apoptosis inhibitors Ac-YVAD-cmk and zVAD-fmk.
After onset of the disease, these agents had no suppressive effect on EAE and
resulted in impaired recovery or earlier relapse. Histological examination
revealed that administration of zVAD-fmk suppressed the apoptotic death of
inflammatory cells in the central nervous system (CNS) of mice with EAE. The
results indicated that the apoptotic elimination of infiltrated cells in the CNS
might be one of the recovery mechanisms in EAE.
PMID- 10673377
TI - Abundant expression of 150-kDa oxygen-regulated protein in mouse pancreatic beta
cells is correlated with insulin secretion.
AB - The 150-kDa oxygen-regulated protein (ORP150) is a member of glucose-regulated
proteins (GRPs), which are induced by stressful conditions such as oxygen or
glucose deprivation. Here we investigated the highly abundant expression of
ORP150 in mouse pancreas and its relationship with insulin secretion.
Immunohistochemical analysis revealed that ORP150 expression was restricted to
islets, especially to beta cells. The beta cell-specific expression was also
observed in a mouse insulinoma cell line, MIN6, which secretes insulin in
response to increased glucose concentration. Furthermore, ORP150 in islets
dramatically diminished by fasting, concomitant with reduction of the serum
insulin level. These results strongly suggest the role for ORP150 in insulin
secretion.
PMID- 10673378
TI - Electric field-mediated DNA encapsulation into large liposomes.
AB - Large, ethidium bromide-loaded liposomes electrically pulsed in the presence of
externally added DNA display the bright fluorescence of DNA-ethidium bromide
complexes. Sonication of these liposomes increases the fluorescence of trapped
DNA-ethidium bromide complexes by no more than about 40%. These results are thus
in agreement with a mechanism involving electropores for DNA uptake but do not
support an alternative mechanism, invoking invagination and pinching-off of the
lipid bilayer, through which internalized DNA is shielded from the liposome
contents.
PMID- 10673379
TI - Hydrophilic residues at the apical domain of GroEL contribute to GroES binding
but attenuate polypeptide binding.
AB - The GroES binding site at the apical domain of GroEL, mostly consisting of
hydrophobic residues, overlaps largely with the substrate polypeptide binding
site. Essential contribution of hydrophobic interaction to the binding of both
GroES and polypeptide was exemplified by the mutant GroEL(L237Q) which lost the
ability to bind either of them. The binding site, however, contains three
hydrophilic residues, E238, T261, and N265. For GroES binding, N265 is essential
since GroEL(N265A) is unable to bind GroES. E238 contributes to rapid GroES
binding to GroEL because GroEL(E238A) is extremely sluggish in GroES binding.
Polypeptide binding was not impaired by any mutations of E238A, T261A, and N265A.
Rather, these mutants, especially GroEL(N265A), showed stronger polypeptide
binding affinity than wild-type GroEL. Thus, these hydrophilic residues have a
dual role; they help GroES binding on one hand but attenuate polypeptide binding
on the other hand.
PMID- 10673380
TI - Structure-based development of pyridoxal propionate derivatives as specific
inhibitors of cathepsin K in vitro and in vivo.
AB - We found that pyridoxal phosphate shows considerable inhibition of cathepsins.
CLIK-071, in which the phosphate ester of position 3 of pyridoxal phosphate was
replaced by propionate, strongly inhibited cathepsin B. Three new types of
synthetic pyridoxal propionate derivatives showing specific inhibition of
cathepsin K were developed. New synthetic pyridoxal propionate derivatives, -162,
-163, and -164, in which the methyl arm of position 6 of CLIK-071 was
additionally modified, strongly inhibited cathepsin K and cathepsin S weakly, but
other cathepsins were not inhibited. CLIK-166, in which the position 4 aldehyde
of CLIK-071 is replaced by a vinyl radical and position 5 is additionally
modified, showed cathepsin K-specific inhibition at 10(-5) M. Pit formation due
to bone collagen degradation by cathepsin K of rat osteoclasts was specifically
suppressed by administration of CLIK-164, but not by inhibitors of cathepsin L or
B.
PMID- 10673381
TI - The C1orf9 gene encodes a putative transmembrane member of a novel protein
family.
AB - Here we report the characterization of a human mRNA encoding a novel protein
denoted C1orf9 (chromosome 1 open reading frame 9). The cDNA sequence, derived
from a testis cDNA library, contains 5700 bp which encodes an open reading frame
of 1254 amino acids. The deduced protein contains a putative N-terminal signal
peptide and one putative transmembrane region, indicating membrane localization.
No significant homology was found with known characterized proteins. However, a
150 amino acid region has significant homology to deduced protein sequences from
other organisms, including Caenorhabditis elegans (43% identity), Saccharomyces
cerevisiae (47% identity), Schizosaccharomyces pombe (48% identity), and two
proteins from Arabidopsis thaliana (42% and 40% identity), suggesting a novel
family of conserved domains. The C1orf9 gene was assigned to chromosome 1q24. The
gene spans approximately 78.7 kb and is organized into at least 24 exons.
Expression analysis revealed a single C1orf9 mRNA species of approximately 6.0 kb
with a predominant expression in pancreas and testis, and only low levels of
expression in other tissues examined.
PMID- 10673382
TI - Rapid gene repression triggered by interleukin-6 at the onset of monocyte
differentiation.
AB - To date, the majority of characterized extracellular ligand-induced rapid changes
in gene expression involve upregulation. Hence, rapid gene repression is either
less common or less well studied. To study rapid gene repression during cytokine
initiated differentiation programs, we used the mRNA subtractive hybridization
technique of representational difference analysis to isolate repressed genes.
Cultures of the myeloid leukemia cell line M1 were induced to terminally
differentiate by treatment with interleukin-6 (IL-6). The repressed genes
identified in our subtraction products include the genes encoding the growth
factor receptor Flt3/Flk2/STK-1 (CD135) and the costimulatory protein CD24 [heat
stable antigen] and the c-myb oncogene. Following 4 h of IL-6 treatment, mRNA
levels of these genes are decreased by 45-65% relative to controls and after 8 h
by 65-80%. Lipopolysaccharide also triggers the repression of these genes.
Protein synthesis inhibitors do not block the IL-6-stimulated repression of c
myb, or c-myc, mRNA, yet they do block the repression of flt3 and CD24 mRNA,
demonstrating the existence of both protein synthesis-independent and -dependent
mechanisms of cytokine-triggered rapid gene repression during differentiation.
PMID- 10673383
TI - Coordinate recruitment of E-cadherin and ALCAM to cell-cell contacts by alpha
catenin.
AB - Here we report on the role of alpha-catenin in the cellular localization of
activated leukocyte cell adhesion molecule, ALCAM, and cadherin-mediated cell
adhesion in human prostate cancer cells. Cell lines that have a functional E
cadherin-mediated cell adhesion (DU-145 and LNCaP) show ALCAM staining at cell
cell contacts. In contrast, in cell lines that lack alpha-catenin expression
(ALVA-31, PC-3, and PPC-1), E-cadherin-mediated adhesion is disturbed and ALCAM
staining is cytoplasmic. A role of alpha-catenin in the recruitment of E-cadherin
and ALCAM to cell-cell contacts was established by transfection of an alpha-N
catenin construct into cell lines ALVA-31 and PC-3. This resulted not only in the
correct assembly of E-cadherin/alpha-catenin complexes at the cell membrane but
also in localization of ALCAM to cell-cell contacts, indicating that indeed alpha
catenin affects ALCAM localization.
PMID- 10673384
TI - Molecular mechanisms of platelet exocytosis: requirements for alpha-granule
release.
AB - Platelets function by secreting components necessary for primary clot formation.
This report describes an in vitro assay that measures alpha-granule secretion.
Using permeabilized platelets, it is possible to recreate Ca(2+)-stimulated
release of platelet factor 4 (PF4) that is ATP- and temperature-dependent. Though
other divalent cations can replace Ca(2+) (i.e., Sr(2+), Mn(2+), Zn(2+)), there
is no effect of Ba(2+). Analysis by electron microscopy indicates that the in
vitro assay also mimics the cytoskeletal rearrangements and granule
centralization that occurs upon platelet activation in vivo. Antibody inhibition
studies show that PF4 release requires the general membrane fusion protein N
ethylmaleimide-sensitive factor (NSF) and well as the target membrane SNAP
receptors (t-SNAREs), syntaxin 2, 4, and SNAP-23. As shown by electron
microscopy, the anti-t-SNARE antibodies block granule to target membrane fusion.
This finding is unique in that it is the first report of a role for two syntaxins
in the same exocytosis event.
PMID- 10673385
TI - The internalization and endosomal trafficking of the EGF receptor in response to
EGF is delayed in the waved-2 mouse liver.
AB - The EGF receptor in waved-2 mice contains a point mutation that renders it kinase
deficient. We investigated how the waved-2 mutation affects the internalization
and endosomal trafficking of the receptor in vivo in response to EGF. When the
waved-2 mice were injected with EGF, there was approximately 50% less tyrosine
phosphorylation detected in whole-liver homogenate compared to wild-type
background mice. Although EGF increased the EGF receptor levels in the early and
late liver endosomal fractions of waved-2 mice, its trafficking was delayed
compared to wild-type mice. Ubiquitination of the EGF receptor may affect its
endosomal sorting. We found that a similar amount of EGF receptor was
immunoprecipitated from the endosomal fractions of EGF-treated waved-2 and wild
type with anti-ubiquitin antibody. These results demonstrate that the waved-2 EGF
receptor can become ubiquitinated and can be trafficked to the late endosomes,
although it appears that its kinase deficiency delays this process.
PMID- 10673386
TI - Cloning and characterization of an alpha-neurotoxin-type protein specific for the
coral snake Micrurus corallinus.
AB - During the cloning of abundant cDNAs expressed in the Micrurus corallinus coral
snake venom gland, we cloned an alpha-neurotoxin homologue cDNA (nxh1). Two
others isoforms were also cloned (nxh3 and nxh7, respectively). The nxh1 cDNA
codes for a potential coral snake toxin with a signal peptide of 21 amino acids
plus a predicted mature peptide with 57 amino acids. The deduced protein is
highly similar to known toxic three-finger alpha-neurotoxins, with four deduced S
S bridges at the same conserved positions. This is the first cDNA coding for a
three-finger related protein described so far for coral snakes. However, the
predicted protein does not possess some of the important amino acids for the
nicotinic acetylcholine receptor interaction. This protein was expressed in
Escherichia coli as a His-tagged protein that allowed the rapid purification of
the recombinant protein. This protein was used to generate antibodies which
recognized the recombinant protein in Western blot and also a single band present
in the M. corallinus venom, but not in the venom of 10 other Micrurus species.
PMID- 10673387
TI - Involvement of extracellular signal-regulated protein kinase in gliosis induced
during recovery from metabolic inhibition.
AB - Brain reperfusion may be of particular importance in the etiology of
periventricular leukomalacia, of which the common findings are gliosis and
ventricular dilatation. To investigate the mechanism of this pathogenesis, we
used a metabolic inhibition (MI) model using cyanide plus deoxyglucose treatment
of cultured glia isolated from fetal rat brain and examined the activity of
extracellular signal-regulated protein kinase (ERK) during MI and also during the
recovery from MI of 30 min. ERK activation was stimulated during MI and the
recovery from MI. The time course and extent of activation of ERK during MI and
the recovery from MI, however, were distinctly different. Activation of ERK was
stimulated within 5 min of MI and declined thereafter. Activation of ERK was
sustained during the recovery phase from MI and the extent of the activation was
much greater than that during MI. Pretreatment with EGTA to eliminate
extracellular Ca(2+), or with APV, an NMDA receptor antagonist, to inhibit Ca(2+)
influx through the NMDA receptor, attenuated the activation of ERK. Moreover,
pretreatment with PMA to downregulate PKC abolished the activation of ERK.
PD98059, an inhibitor of ERK kinase, attenuated the cell proliferation induced by
MI followed by recovery from MI. These results suggest that ERK is involved in
gliosis during the recovery phase from MI and may play a role in the etiology of
periventricular leukomalacia.
PMID- 10673388
TI - The lipid component of lipoproteins from Borrelia burgdorferi: structural
analysis, antigenicity, and presentation via human dendritic cells.
AB - The spirochaetal bacteria Borrelia burgdorferi (Bb) is the tick-borne causative
agent of lyme disease. The major membrane immunogens of Bb are outer surface
proteins. The lipid component of these lipoproteins is relevant for the
immunogenicity of Bb-lipoproteins. To characterize the antigenic properties, the
native lipid component of lipoproteins was isolated and the detailed molecular
structure was analyzed. The molecular structure of the lipoprotein-lipid
component turned out to be S(propane-2',-3'diol)-3-thio-2-aminopropanic acid (S
glyceryl-cysteine) with one ester-linked fatty acid, one acetyl group, and one N
terminal amide-bound fatty acid. Fatty acid analysis of the lipid component
indicated a heterogeneous composition comprising C16:0, C18:0, C18:1, C18:2, and
C 20:0. The antigenicity was tested with in vitro bioassays using human blood
derived dendritic cells (DCs) as antigen-presenting cells and autologous Bb
specific T-cells. We found that human DCs present the lipid component of Bb
lipoproteins via MHC class II inducing an antigen-specific T-cell immune response
in vitro.
PMID- 10673389
TI - BERP, a novel ring finger protein, binds to alpha-actinin-4.
AB - We recently identified BERP as a novel RING finger protein belonging to the RBCC
protein family. It contains an N-terminal RING finger, followed by a B-box zinc
finger and a coiled-coil domain. BERP interacts with the tail domain of the class
V myosins through a beta-propeller structure in the BERP C-terminal. To identify
other proteins interacting with BERP, the yeast two-hybrid strategy was employed,
using the RBCC domain as bait. Screening of a rat brain cDNA library identified
alpha-actinin-4 as a specific binding partner for the N-terminus of BERP. This
actinin isoform could be immunoprecipitated together with BERP from HEK 293 cells
transfected with expression constructs for BERP and alpha-actinin-4. These
proteins could also be colocalized immunohistochemically in the cytoplasm of
differentiated PC12 cells. We suggest that BERP may anchor class V myosins to
particular cell domains via its interaction with alpha-actinin-4.
PMID- 10673390
TI - Role of troponin I isoform switching in determining the pH sensitivity of Ca(2+)
regulation in developing rabbit cardiac muscle.
AB - Skinned muscle fibers prepared from fetal rabbit heart (28 days of gestation)
showed a marked resistance to acidic pH in the Ca(2+) regulation of force
generation, compared to the fibers prepared from adult heart. SDS-PAGE and
immunoblot analysis showed that the slow skeletal troponin I was predominantly
expressed in the fetal cardiac muscle, while the cardiac isoform was
predominantly expressed in the adult cardiac muscle. Direct exchange of purified
slow skeletal and cardiac troponin I isoforms into these skinned muscle fibers
revealed that cardiac troponin I made the Ca(2+) regulation of contraction
sensitive to acidic pH just as in the adult fibers, whereas slow skeletal
troponin I made the Ca(2+) regulation of contraction resistant to acidic pH just
as in the fetal fibers. These results demonstrate that the troponin I isoform
switching accounts fully for the change in the pH dependence of Ca(2+) regulation
of contraction in developmental cardiac muscle.
PMID- 10673391
TI - Novel functions of human alpha(1)-protease inhibitor after S-nitrosylation:
inhibition of cysteine protease and antibacterial activity.
AB - alpha(1)-Protease inhibitor (alpha(1)PI), the most abundant serine protease
inhibitor found in human plasma (at 30-60 microM), is a glycoprotein (53 kDa)
having a single cysteine residue at position 232 (Cys(232)). We have found that
Cys(232) of human alpha(1)PI was readily S-nitrosylated by nitric oxide (NO)
without affecting inhibitory activity to trypsin or elastase. S-nitrosylated
alpha(1)PI (S-NO-alpha(1)PI) not only retained inhibitory activity against these
serine proteases, but also gained thiol protease inhibitory activity against a
Streptococcus pyogenes protease; the parental alpha(1)PI did not have this
activity. Furthermore, S-NO-alpha(1)PI exhibited bacteriostatic activity against
Salmonella typhimurium at concentrations of 0.1-10 microM, which were 20- to 3000
fold stronger than those of the other NO-generating compounds or S-nitroso
compounds such as S-nitrosoalbumin and S-nitrosoglutathione. NO appears to be
transferred into the bacterial cells from S-NO-alpha(1)PI via transnitrosylation,
as evidenced by electron spin resonance spectroscopy with an NO spin trap. Thus,
we conclude that S-NO-alpha(1)PI may be generated from the reaction between
alpha(1)PI and NO under inflammatory conditions, in which production of both is
known to increase. As a result, new functions, i.e., antibacterial and thiol
protease inhibitory activities of alpha(1)PI, were generated.
PMID- 10673392
TI - Biological activity of human granulocyte colony stimulating factor with a
modified C-terminus.
AB - Granulocyte colony-stimulating factor (G-CSF) undergoes receptor-mediated
internalization into target cells which are normally restricted to neutrophilic
granulocytes and their committed progenitor cells, suggesting that it may be
applicable as a myeloid cell-targeting vehicle. To test this notion, we
constructed a cDNA encoding a human G-CSF/murine stem cell factor (mSCF) chimeric
molecule in a mammalian expression vector and transfected NIH3T3 cells with this
plasmid. The resulting chimeric cytokine consisted of the entire G-CSF sequences
fused to Lys148 of mSCF. It can be released from the surface membrane of NIH3T3
transformants through proteolytic cleavage at Ala164 of mSCF. The culture media
conditioned by a number of stable transformants, which were confirmed by an
enzyme-linked immunosorbent assay (ELISA) to secrete an hG-CSF derivative, were
examined for their ability to stimulate CFU-G-derived colony formation as well as
the proliferation of G-CSF-dependent NFS-60 cells. The results indicated that
this C-terminus modified version of hG-CSF is as potent as recombinant hG-CSF in
both assays.
PMID- 10673393
TI - Heterooligomer of type 1 and type 2 inositol 1, 4, 5-trisphosphate receptor
expressed in rat liver membrane fraction exists as tetrameric complex.
AB - Functional IP(3)-sensitive intracellular Ca(2+) release channel is considered to
be a tetramer of IP(3)R. Heterooligomeric complexes composed of distinct types of
IP(3)R have been reported, however, crucial evidences for them being tetramer
have not appeared. Here we report that the heterooligomer composed of IP(3)R1 and
IP(3)R2 also exists as tetramer. Cross-linked heterooligomer was
immunoprecipitated with IP(3)R1-specific antibody and detected by agarose
PAGE/Western blot analysis with IP(3)R2-specific antibody. Tetramer, trimer,
dimer, and possibly monomer were detected. The trimer, dimer, and monomer were
likely to be originated from the tetramer, since: (1) the immunoprecipitating
antibody (IP(3)R1-specific) does not recognize IP(3)R2, therefore IP(3)R2 monomer
itself could not have been immunoprecipitated; and (2) tetramer was the major
native product of IP(3)R complex containing type 2 isoform in liver membrane
fraction. Thus we conclude tetramer is the native form of heterooligomer composed
of IP(3)R1 and IP(3)R2.
PMID- 10673394
TI - Specific modulation of p53 binding to consensus sequence within supercoiled DNA
by monoclonal antibodies.
AB - Monoclonal antibodies (MAbs) were used to investigate the binding of insect cell
expressed, wild-type human p53 protein to the consensus sequence (p53CON) in a
474-bp DNA fragment and to supercoiled (sc) DNAs with and without p53CON.
Supershifting of p53-DNA complexes by MAbs in agarose gels was applied to studies
of activation of p53 for sequence-specific binding within scDNA. C-terminal
specific antibody Bp53-10.1 activated the sequence-specific binding of p53 to
p53CON within pPGM1 scDNA but did not influence binding of p53 to pBluescript
scDNA (not containing p53CON). Incubation of p53 with DO-1 prior to addition of
Bp53-10.1 prevented activation of p53 and induced dissociation of a portion of
pPGM1 scDNA from the sequence-specific immune complex; no such dissociation was
observed if pPGM1 scDNA was replaced by the 474-bp p53CON-containing DNA
fragment.
PMID- 10673395
TI - Structure-function analysis of the 7B2 CT peptide.
AB - Prohormone convertases play important roles in the proteolytic conversion of many
protein precursors. The neuroendocrine protein 7B2 and its 31-residue carboxyl
terminal (CT) peptide potently and specifically inhibit prohormone convertase 2
(PC2). We have analyzed the residues contributing to inhibition using N-terminal
truncation and alanine scanning. Removal of more than 3 residues from the amino
terminal end of CT1-18 resulted in a more than 190-fold drop in inhibitory
activity, showing that most of the residues between 3 and 18 are required for
inhibition. In agreement, an Ala scan indicated that only 4 residues could be
replaced with Ala without losing mid-nanomolar inhibitory potency; in particular,
Gln7, Gln9, and Asp12 could be Ala-substituted to yield peptides with a similar
inhibitory potency to the starting peptide. The all-d-retro-inverso, all-l
inverso, and all-d analogues of CT peptide were completely inactive, indicating
that amino acid side chains and the CT peptide main chain interact with PC2. CT
peptide inhibition could not be competitively blocked by preincubation with
truncated CT peptide forms, supporting an absolute requirement for the Lys-Lys
pair in initial binding of the CT peptide to the active site.
PMID- 10673396
TI - CFU-GM-derived cells form osteoclasts at a very high efficiency.
AB - The granulocyte-macrophage progenitor (CFU-GM) is a multipotent cell that can
differentiate to osteoclasts (OCLs), macrophages, or granulocytes. However, the
relative potential of CFU-GM to efficiently form OCLs is unknown. In this report
we demonstrate that granulocyte-macrophage colony-forming unit (CFU-GM)-derived
cells represent an easily obtainable highly purified source of human OCL
precursors that form OCLs at very high efficiency (greater than 90%) when
cultured with RANK ligand (RANKL), macrophage colony-stimulating factor (M-CSF),
and dexamethasone. The OCLs that formed have high bone-resorbing activity and
form multiple resorption lacunae per OCL on dentin slices. Similarly, murine
marrow-derived CFU-GM also formed OCLs at a high efficiency (>80%) when treated
with RANKL, M-CSF, and dexamethasone. In contrast, more committed macrophage
colony-forming unit (CFU-M)-derived cells form few OCLs under these conditions.
PMID- 10673397
TI - beta3-endonexin as a novel inhibitor of cyclin A-associated kinase.
AB - Cyclin A is indispensable for S phase cell cycle progression and is suggested to
be a crucial target of cell adhesion signals. In this study, we demonstrate that
beta3-endonexin, a molecule known to associate with the integrin beta3
cytoplasmic domain, specifically binds cyclin A. Deletion of the amino-terminal
52-amino-acid residues including the cyclin-binding RxL motif abolishes the
ability of beta3-endonexin to interact with cyclin A. In an in vitro kinase
assay, beta3-endonexin inhibits pRB kinase activity associated with cyclin A-Cdk2
while leaving its histone H1 kinase activity unaffected. Coexpression of beta3
endonexin in yeast cells overcomes growth suppression caused by an activation of
cyclin A-associated kinase. Our results indicate that beta3-endonexin is a novel
cyclin A-binding molecule that regulates cyclin A-associated pRB kinase activity.
PMID- 10673398
TI - The oxidative stress-sensitive yap1 null strain of Saccharomyces cerevisiae
becomes resistant due to increased carotenoid levels upon the introduction of the
Chlamydomonas reinhardtii cDNA, coding for the 60S ribosomal protein L10a.
AB - The Saccharomyces cerevisiae yap1 null strain was transformed with a
Chlamydomonas reinhardtii cDNA expression library. A 688-bp cDNA fragment, coding
for the 60S ribosomal protein L10a (RPL10a), restored the capacity of the S.
cerevisiae yap1 null strain to resist oxidative stress. The rpl10a gene is a
single-copy gene in C. reinhardtii and encodes a constitutively produced 1.35-kb
mRNA. The deduced 214-residue amino acid sequence was highly related with RPL10a
proteins from eukarya (between 46.1 and 63.7% identity) and archaea (between 24.5
and 29.2% identity). Resistant transformants were pink, due to increased
carotenoid levels, with the same chemical structure as torularhodin, the main
carotenoid of the pink yeast Rhodotorula mucilaginosa. The pink transformants
showed high resistance levels against H(2)O(2), paraquat, menadione, and UV
light. Partial inhibition of the carotenoid synthesis by diphenylamine reduced
the resistance levels, demonstrating the role of excess carotenoid synthesis in
the resistance mechanism.
PMID- 10673399
TI - Interferon-gamma mediates gene expression of IL-18 binding protein in
nonleukocytic cells.
AB - Interleukin-18 (IL-18) binding protein is a soluble decoy receptor for IL-18
which efficiently antagonizes biological functions of IL-18 in vitro and in vivo.
Since regulation of IL-18 activity likely contributes to the pathogenesis of
inflammatory diseases as well as malignancies, we investigated gene expression of
IL-18 binding protein (IL-18BP) in different human cell systems, namely in the
keratinocyte cell line HaCaT, in the colon carcinoma cell line DLD-1, and in
primary renal mesangial cells. In unstimulated cells only minute amounts of mRNA
coding for IL-18 binding protein were detectable. However, in all three cell
types gene expression was markedly upregulated by interferon-gamma (IFN-gamma).
IL-18 is recognized as a pivotal mediator of IFN-gamma production. Therefore, the
present data imply that activity of IL-18 is modulated by a negative feedback
mechanism which is mediated by IFN-gamma-induced IL-18 binding protein.
PMID- 10673400
TI - Biasing in Gaussian Random Fields and Galaxy Correlations.
AB - In this Letter, we show that in a Gaussian random field, the correlation length
the typical size of correlated structures-does not change with biasing. We
interpret the amplification of the correlation functions of subsets identified by
different thresholds as being caused by the increasing sparseness of peaks over
threshold. This clarifies a long-standing misconception in the literature. We
also argue that this effect does not explain the observed increase of the
amplitude of the correlation function xi(r) when galaxies of brighter luminosity
or galaxy clusters of increasing richness are considered.
PMID- 10673401
TI - A Definitive Optical Detection of a Supercluster at z approximately 0.91.
AB - We present the results from a multiband optical imaging program that has
definitively confirmed the existence of a supercluster at z approximately 0.91.
Two massive clusters of galaxies, Cl 1604+4304 at z=0.897 and Cl 1604+4321 at
z=0.924, were originally observed in the high-redshift cluster survey of Oke,
Postman, & Lubin. They are separated by 4300 km s-1 in radial velocity and
17&arcmin; on the plane of the sky. Their physical and redshift proximity
suggested a promising supercluster candidate. Deep BRi imaging of the region
between the two clusters indicates a large population of red galaxies. This
population forms a tight, red sequence in the color-magnitude diagram at (R
i&parr0; approximately 1.4. The characteristic color is identical to that of the
spectroscopically confirmed early-type galaxies in the two member clusters. The
red galaxies are spread throughout the 5 h-1 Mpc region between Cl 1604+4304 and
Cl 1604+4321. Their spatial distribution delineates the entire large-scale
structure with high concentrations at the cluster centers. In addition, we detect
a significant overdensity of red galaxies directly between Cl 1604+4304 and Cl
1604+4321 which is the signature of a third, rich cluster associated with this
system. The strong sequence of red galaxies and their spatial distribution
clearly indicate that we have discovered a supercluster at z approximately 0.91.
PMID- 10673402
TI - A Chandra High-Resolution X-ray Image of Centaurus A.
AB - We present first results from a Chandra X-Ray Observatory observation of the
radio galaxy Centaurus A with the High-Resolution Camera. All previously reported
major sources of X-ray emission including the bright nucleus, the jet, individual
point sources, and diffuse emission are resolved or detected. The spatial
resolution of this observation is better than 1&arcsec; in the center of the
field of view and allows us to resolve X-ray features of this galaxy not
previously seen. In particular, we resolve individual knots of emission in the
inner jet and diffuse emission between the knots. All of the knots are diffuse at
the 1&arcsec; level, and several exhibit complex spatial structure. We find the
nucleus to be extended by a few tenths of an arcsecond. Our image also suggests
the presence of an X-ray counterjet. Weak X-ray emission from the southwest radio
lobe is also seen, and we detect 63 pointlike galactic sources (probably X-ray
binaries and supernova remnants) above a luminosity limit of approximately
1.7x1037 ergs s-1.
PMID- 10673403
TI - Implications of the X-Ray Variability for the Mass of MCG -6-30-15.
AB - The bright Seyfert 1 galaxy MCG -6-30-15 shows large variability on a variety of
timescales. We study the less, similar3 day timescale variability using a set of
simultaneous archival observations that were obtained from the Rossi X-Ray Timing
Explorer (RXTE) and the Advanced Satellite for Cosmology and Astrophysics (ASCA).
The RXTE observations span nearly 106 s and indicate that the X-ray Fourier power
spectral density has an rms variability of 16%, is flat from approximately 10-6
to 10-5 Hz, and then steepens into a power law proportional to f-alpha with alpha
greater, similar1. A further steepening to alpha approximately 2 occurs between
10-4 and 10-3 Hz. The shape and rms amplitude are comparable to what has been
observed in NGC 5548 and Cyg X-1, albeit with break frequencies that differ by a
factor of 10-2 and 104, respectively. If the break frequencies are indicative of
the central black hole mass, then this mass may be as low as 106 M middle dot in
circle. An upper limit of approximately 2 ks for the relative lag between the 0.5
2 keV ASCA band compared to the 8-15 keV RXTE band was also found. Again by
analogy with NGC 5548 and Cyg X-1, this limit is consistent with a relatively low
central black hole mass.
PMID- 10673404
TI - A Unified Scaling Law in Spiral Galaxies.
AB - We investigate the origin of a unified scaling relation in spiral galaxies.
Observed spiral galaxies are spread on a plane in the three-dimensional
logarithmic space of luminosity L, radius R, and rotation velocity V. The plane
is expressed as L~&parl0;VR&parr0;alpha in the I passband, where alpha is a
constant. On the plane, observed galaxies are distributed in an elongated region
which looks like the shape of a surfboard. The well-known scaling relations L-V
(Tully-Fisher [TF] relation), V-R (also the TF relation), and R-L (Freeman's law)
can be understood as oblique projections of the surfboard-like plane into two
dimensional spaces. This unified interpretation of the known scaling relations
should be a clue to understand the physical origin of all the relations
consistently. Furthermore, this interpretation can also explain why previous
studies could not find any correlation between TF residuals and radius. In order
to clarify the origin of this plane, we simulate formation and evolution of
spiral galaxies with the N-body/smoothed particle hydrodynamics method, including
cooling, star formation, and stellar feedback. Initial conditions are set to 14
isolated spheres with two free parameters, such as mass and angular momentum. The
cold dark matter (h=0.5, Omega0=1) cosmology is considered as a test case. The
simulations provide the following two conclusions: (1) The slope of the plane is
well reproduced but the zero point is not. This zero-point discrepancy could be
solved in a low-density (Omega0<1) and high-expansion (h>0.5) cosmology. (2) The
surfboard-shaped plane can be explained by the control of galactic mass and
angular momentum.
PMID- 10673405
TI - The Modified Dynamics is Conducive to Galactic Warp Formation.
AB - There is an effect in the modified dynamics that is conducive to the formation of
warps. Because of the nonlinearity of the theory, the internal dynamics of a
galaxy is affected by a perturber over and above possible tidal effects. For
example, a relatively distant and light companion or the mean influence of a
parent cluster, with negligible tidal effects, could still produce a significant
warp in the outer part of a galactic disk. We present results of numerical
calculations for simplified models that show, for instance, that a satellite with
the (baryonic) mass and distance of the Magellanic Clouds can distort the
axisymmetric field of the Milky Way enough to produce a warp of the magnitude
(and position) observed. Details of the warp geometry remain to be explained; we
use a static configuration that can produce only warps with a straight line of
nodes. In more realistic simulations, one must reckon with the motion of the
perturbing body, which sometimes occurs on timescales not much longer than the
response time of the disk.
PMID- 10673406
TI - The Optical Gravitational Lensing Experiment: Red Clump Stars as a Distance
Indicator.
AB - We present relation of the mean I-band brightness of red clump stars on
metallicity. Red clump stars were proposed to be a very attractive standard
candle for distance determination. The calibration is based on 284 nearby red
giant stars whose high-quality spectra made it possible to determine accurate
individual metal abundances. High-quality parallaxes (sigmapi&solm0;pi<10%) and
photometry of these very bright stars come from Hipparcos measurements.
Metallicity of the sample covers a large range: -0.6
dex<&sqbl0;Fe&solm0;H&sqbr0;<+0.2 dex. We find a weak dependence of the mean I
band brightness on metallicity ( approximately 0.13 mag dex-1). What is more
important, the range of metallicity of the Hipparcos sample partially overlaps
with metallicity of field giants in the LMC, thus making it possible to determine
the distance to the LMC by almost direct comparison of brightness of the local
Hipparcos red clump giants with that of LMC stars. Photometry of field red clump
giants in nine low-extinction fields of the LMC halo collected during the OGLE II
microlensing survey compared with the Hipparcos red clump stars data yields the
distance modulus to the LMC: &parl0;m-M&parr0;LMC=18.24+/-0.08 mag.
PMID- 10673407
TI - Testing Population Synthesis Models with Globular Cluster Colors.
AB - We have measured an extensive set of UBVRIJHK colors for M31 globular clusters.
We compare the predicted simple stellar population colors of three population
synthesis models to the intrinsic colors of Galactic and M31 globular clusters.
The best-fitting models fit the cluster colors very well: the weighted mean color
offsets are all smaller than 0.05 mag. The most significant offsets between model
and data are in the U and B passbands; these are not unexpected and are likely
caused by problems with the spectral libraries used by the models. The metal-rich
clusters (&sqbl0;Fe&solm0;H&sqbr0; greater, similar-0.8) are best fit by young (8
Gyr) models, while the metal-poor clusters are best fit by older (12-16 Gyr)
models. If this range of globular cluster ages is correct, it implies that
conditions for cluster formation must have existed for a substantial fraction of
the galaxies' lifetimes.
PMID- 10673408
TI - Probing the Site for r-Process Nucleosynthesis with Abundances of Barium and
Magnesium in Extremely Metal-poor Stars.
AB - We suggest that if the astrophysical site for r-process nucleosynthesis in the
early Galaxy is confined to a narrow mass range of Type II supernova (SN II)
progenitors, with a lower mass limit of Mms=20 M middle dot in circle, a unique
feature in the observed distribution of [Ba/Mg] versus [Mg/H] for extremely metal
poor stars can be adequately reproduced. We associate this feature, a bifurcation
of the observed elemental ratios into two branches in the Mg abundance interval
3.7=&sqbl0;Mg&solm0;H&sqbr0;=-2.3, with two distinct processes. The first
branch, which we call the y-branch, is associated with the production of Ba and
Mg from individual massive supernovae. The derived mass of Ba synthesized in SNe
II is 8.5x10-6 M middle dot in circle for Mms=20 M middle dot in circle and
4.5x10-8 M middle dot in circle for Mms=25 M middle dot in circle. We conclude
that SNe II with Mms approximately 20 M middle dot in circle are the dominant
source of r-process nucleosynthesis in the early Galaxy. An SN-induced chemical
evolution model with this Mms-dependent Ba yield creates the y-branch, reflecting
the different nucleosynthesis yields of [Ba/Mg] for each SN II with Mms greater,
similar20 M middle dot in circle. The second branch, which we call the i-branch,
is associated with the elemental abundance ratios of stars which were formed in
the dense shells of the interstellar medium swept up by SNe II with Mms<20 M
middle dot in circle that do not synthesize r-process elements, and it applies to
stars with observed Mg abundances in the range &sqbl0;Mg&solm0;H&sqbr0;<-2.7. The
Ba abundances in these stars reflect those of the interstellar gas at the (later)
time of their formation. The existence of a [Ba/Mg] i-branch strongly suggests
that SNe II that are associated with stars of progenitor mass Mms=20 M middle
dot in circle are infertile sources for the production of r-process elements. We
predict the existence of this i-branch for other r-process elements, such as
europium (Eu), to the extent that their production site is in common with Ba.
PMID- 10673409
TI - Rotations and Abundances of Blue Horizontal-Branch Stars in Globular Cluster M15.
AB - High-resolution optical spectra of 18 blue horizontal-branch stars in the
globular cluster M15 indicate that their stellar rotation rates and photospheric
compositions vary strongly as a function of effective temperature. Among the
cooler stars in the sample, at Teff approximately 8500 K, metal abundances are in
rough agreement with the canonical cluster metallicity, and the vsini rotations
appear to have a bimodal distribution, with eight stars at vsini<15 km s-1 and
two stars at vsini approximately 35 km s-1. Most of the stars at Teff>/=10,000 K,
however, are slowly rotating, vsini<7 km s-1, and their iron and titanium are
enhanced by a factor of 300 to solar abundance levels. Magnesium maintains a
nearly constant abundance over the entire range of Teff, and helium is depleted
by factors of 10-30 in three of the hotter stars. Diffusion effects in the
stellar atmospheres are the most likely explanation for these large differences
in composition. Our results are qualitatively very similar to those previously
reported for M13 and NGC 6752, but with even larger enhancement amplitudes,
presumably due to the increased efficiency of radiative levitation at lower
intrinsic [Fe/H]. We also see evidence for faster stellar rotation explicitly
preventing the onset of the diffusion mechanisms among a subset of the hotter
stars.
PMID- 10673410
TI - Correlation among Quasi-Periodic Oscillation Frequencies and Quiescent-State
Duration in Black Hole Candidate GRS 1915+105.
AB - We discover a definite correlation between the frequency of the quasi-periodic
oscillations (QPOs) in quiescent states and the duration of the quiescent state
of the transient X-ray source GRS 1915+105. We find that while the QPO frequency
can be explained by the oscillation of shocks in accretion flows, the switching
of burst to quiescent states (and vice versa) and their duration can be explained
by assuming an outflow from the postshock region. The duration of the quiescent
state is inversely related to the QPO frequency. We derive this relation. We also
find the correlation between the observed low ( approximately 0.001-0.01 Hz) and
the intermediate (1-10 Hz) QPO frequencies. Our analytical solutions are verified
by analyzing several days of public domain data from the Rossi X-Ray Timing
Explorer.
PMID- 10673411
TI - Phase Lag and Coherence Function of X-Ray Emission from Black Hole Candidate XTE
J1550-564.
AB - We report the results from measuring the phase lag and coherence function of X
ray emission from black hole candidate XTE J1550-564. These temporal X-ray
properties have been recognized to be increasingly important in providing
important diagnostics of the dynamics of accretion flows around black holes. For
XTE J1550-564, we found significant hard lag-the X-ray variability in high-energy
bands lags behind that in low-energy bands-associated both with broadband
variability and quasi-periodic oscillation (QPO). However, the situation is more
complicated for the QPO: while hard lag was measured for the first harmonic of
the signal, the fundamental component showed significant soft lag. Such behavior
is remarkably similar to what was observed of microquasar GRS 1915+105. The phase
lag evolved during the initial rising phase of the 1998 outburst. The magnitude
of both the soft and hard lags of the QPO increases with X-ray flux, while the
Fourier spectrum of the broadband lag varies significantly in shape. The
coherence function is relatively high and roughly constant at low frequencies and
begins to drop almost right after the first harmonic of the QPO. It is near unity
at the beginning and decreases rapidly during the rising phase. Also observed is
that the more widely separated the two energy bands are, the less the coherence
function between the two. It is interesting that the coherence function increases
significantly at the frequencies of the QPO and its harmonics. We discuss the
implications of the results on the models proposed for black hole candidates.
PMID- 10673412
TI - Advection-dominated Inflow/Outflows from Evaporating Accretion Disks.
AB - In this Letter we investigate the properties of advection-dominated accretion
flows (ADAFs) fed by the evaporation of a Shakura-Sunyaev accretion disk (SSD).
In our picture, the ADAF fills the central cavity evacuated by the SSD and
extends beyond the transition radius into a coronal region. We find that, because
of global angular momentum conservation, a significant fraction of the hot gas
flows away from the black hole, forming a transsonic wind, unless the injection
rate depends only weakly on radius (if r2sigma&d2;~r-xi, xi<1&solm0;2). The
Bernoulli number of the inflowing gas is negative if the transition radius is
less, similar100 Schwarzschild radii, so matter falling into the hole is
gravitationally bound. The ratio of inflowing to outflowing mass is approximately
1/2, so in these solutions the accretion rate is of the same order as in standard
ADAFs and much larger than in advection-dominated inflow/outflow models. The
possible relevance of evaporation-fed solutions to accretion flows in black hole
X-ray binaries is briefly discussed.
PMID- 10673413
TI - The Compact Central Object in Cassiopeia A: A Neutron Star with Hot Polar Caps or
a Black Hole?
AB - The central pointlike X-ray source of the Cassiopeia A supernova remnant was
discovered in the Chandra first light observation and found later in the archival
ROSAT and Einstein images. The analysis of these data does not show statistically
significant variability of the source. Because of the small number of photons
detected, different spectral models can fit the observed spectrum. The power-law
fit yields the photon index gamma=2.6-4.1, and luminosity L(0.1-5.0
keV&parr0;=&parl0;2-60&parr0;x1034 ergs s-1 for d=3.4 kpc. The power-law index is
higher, and the luminosity lower, than those observed from very young pulsars.
One can fit the spectrum equally well with a blackbody model with T=6-8 MK, R=0.2
0.5 km, and Lbol=&parl0;1.4-1.9&parr0;x1033 ergs s-1. The inferred radii are too
small, and the temperatures too high, for the radiation to be interpreted as
emitted from the whole surface of a uniformly heated neutron star. Fits with the
neutron star atmosphere models increase the radius and reduce the temperature,
but these parameters are still substantially different from those expected for a
young neutron star. One cannot exclude, however, the possibility that the
observed emission originates from hot spots on a cooler neutron star surface. An
upper limit on the (gravitationally redshifted) surface temperature is
Tinfinitys<1.9-2.3 MK, depending on the chemical composition of the surface and
the star's radius. Among several possible interpretations, we favor a model of a
strongly magnetized neutron star with magnetically confined hydrogen or helium
polar caps (Tinfinitypc approximately 2.8 MK, Rpc approximately 1 km) on a cooler
iron surface (Tinfinitys approximately 1.7 MK). Such temperatures are consistent
with the standard models of neutron star cooling. Alternatively, the observed
radiation may be interpreted as emitted by a compact object (more likely, a black
hole) accreting from a residual disk or from a late-type dwarf in a close binary.
PMID- 10673414
TI - Discovery of a Brown Dwarf Companion to Gliese 570ABC: A 2MASS T Dwarf
Significantly Cooler than Gliese 229B.
AB - We report the discovery of a widely separated (258&farcs;3+/-0&farcs;4) T dwarf
companion to the Gl 570ABC system. This new component, Gl 570D, was initially
identified from the Two Micron All-Sky Survey. Its near-infrared spectrum shows
the 1.6 and 2.2 um CH4 absorption bands characteristic of T dwarfs, while its
common proper motion with the Gl 570ABC system confirms companionship. Gl 570D
(MJ=16.47+/-0.07) is nearly a full magnitude dimmer than the only other known T
dwarf companion, Gl 229B, and estimates of L=&parl0;2.8+/-0.3&parr0;x10-6 L
middle dot in circle and Teff=750+/-50 K make it significantly cooler and less
luminous than any other known brown dwarf companion. Using evolutionary models by
Burrows et al. and an adopted age of 2-10 Gyr, we derive a mass estimate of 50+/
20 MJup for this object.
PMID- 10673415
TI - The Discovery of a Second Field Methane Brown Dwarf from Sloan Digital Sky Survey
Commissioning Data.
AB - We report the discovery of a second field methane brown dwarf from the
commissioning data of the Sloan Digital Sky Survey (SDSS). The object, SDSS
J134646.45-003150.4 (hereafter SDSS 1346-00), was selected because of its very
red color and stellar appearance. Its spectrum between 0.8 and 2.5 um is
dominated by strong absorption bands of H2O and CH4 and closely mimics those of
Gliese 229B and SDSS 162414.37+002915.6 (hereafter SDSS 1624+00), two other known
methane brown dwarfs. SDSS 1346-00 is approximately 1.5 mag fainter than Gliese
229B, suggesting that it lies about 11 pc from the Sun. The ratio of flux at 2.1
um to that at 1.27 um is larger for SDSS 1346-00 than for Gliese 229B and SDSS
1624+00, which suggests that SDSS 1346-00 has a slightly higher effective
temperature than the others. Based on a search area of 130 deg2 and a detection
limit of z*=19.8, we estimate a space density of 0.05 pc-3 for methane brown
dwarfs with Teff approximately 1000 K in the 40 pc3 volume of our search. This
estimate is based on small-sample statistics and should be treated with
appropriate caution.
PMID- 10673416
TI - Analysis of the Hipparcos Measurements of HD 10697: A Mass Determination of a
Brown Dwarf Secondary.
AB - HD 10697 is a nearby main-sequence star around which a planet candidate has
recently been discovered by means of radial velocity measurements (Vogt et al.).
The stellar orbit has a period of about 3 yr, the secondary minimum mass is 6.35
Jupiter masses (MJ), and the minimum semimajor axis is 0.36 mas. Using the
Hipparcos data of HD 10697 together with the spectroscopic elements of Vogt et
al., we found a semimajor axis of 2.1+/-0.7 mas, implying a mass of 38+/-13 MJ
for the unseen companion. We therefore suggest that the secondary of HD 10697 is
probably a brown dwarf, orbiting around its parent star at a distance of 2 AU.
PMID- 10673417
TI - Ultraviolet Photoprocessing of Interstellar Dust Mantles as a Source of
Polycyclic Aromatic Hydrocarbons and Other Conjugated Molecules.
AB - By co-depositing a gas mixture of simple carbon- and nitrogen-containing
molecules with water on a 10 K surface and exposing it to ultraviolet radiation,
we were able to form a residue. This residue was then placed aboard the EURECA
satellite behind a magnesium fluoride window and exposed to solar radiation for 4
months before it was returned and analyzed. The resulting residue is believed to
simulate the photoprocessing of organic dust mantles in the interstellar medium.
Mass spectrometry indicated that the photoprocessing created a rich mixture of
polycyclic aromatic hydrocarbons (PAHs) and other conjugated organic molecules,
which may explain how PAHs are replenished in space.
PMID- 10673418
TI - Implosions in Coronal Transients.
AB - Coronal events such as flares or coronal mass ejections derive their energy from
the energy stored locally in the magnetic field. This leads to the conjecture
that a magnetic implosion must occur simultaneously with the energy release. The
site of the implosion would show the location of preflare energy storage, and its
detection should have a high priority. The Transition Region and Coronal Explorer
EUV observations, for example, have sufficient resolution to show the geometry of
a flare implosion by following the motions of tracers in the images.
PMID- 10673419
TI - Identification of the Coronal Sources of the Fast Solar Wind.
AB - The present spectroscopic study of the ultraviolet coronal emission in a polar
hole, detected on 1996 April 6-9 with the Ultraviolet Coronagraph Spectrometer
aboard the Solar and Heliospheric Observatory spacecraft, identifies the
interplume lanes and background coronal hole regions as the channels in which the
fast solar wind is preferentially accelerated. In interplume lanes, at
heliocentric distance 1.7 R middle dot in circle, the corona expands at a rate
between 105 and 150 km s-1, that is, much faster than in plumes in which the
outflow velocity is between 0 and 65 km s-1. The wind velocity is inferred from
the Doppler dimming of the O vi lambdalambda1032, 1037 lines, within a range of
values, whose lower and upper limit corresponds to anisotropic and isotropic
velocity distribution of the oxygen coronal ions, respectively.
PMID- 10673420
TI - Initial Time Dependence of Abundances in Solar Energetic Particle Events.
AB - We compare the initial behavior of Fe/O and He/H abundance ratios and their
relationship to the evolution of the proton energy spectra in "small" and "large"
gradual solar energetic particle (SEP) events. The results are qualitatively
consistent with the behavior predicted by the theory of Ng et al. published in
1999. He/H ratios that initially rise with time are a signature of scattering by
non-Kolmogorov Alfven wave spectra generated by intense beams of shock
accelerated protons streaming outward in large gradual SEP events.
PMID- 10673421
TI - Crystal structure of RNA 3'-terminal phosphate cyclase, a ubiquitous enzyme with
unusual topology.
AB - BACKGROUND: RNA cyclases are a family of RNA-modifying enzymes that are conserved
in eucarya, bacteria and archaea. They catalyze the ATP-dependent conversion of
the 3'-phosphate to the 2',3'-cyclic phosphodiester at the end of RNA, in a
reaction involving formation of the covalent AMP-cyclase intermediate. These
enzymes might be responsible for production of the cyclic phosphate RNA ends that
are known to be required by many RNA ligases in both prokaryotes and eukaryotes.
RESULTS: The high-resolution structure of the Escherichia coli RNA 3'-terminal
phosphate cyclase was determined using multiwavelength anomalous diffraction. Two
orthorhombic crystal forms of E. coli cyclase (space group P2(1)2(1)2(1) and
P2(1)2(1)2) were used to solve and refine the structure to 2.1 A resolution (R
factor 20.4%; R(free) 27.6%). Each molecule of RNA cyclase consists of two
domains. The larger domain contains three repeats of a folding unit comprising
two parallel alpha helices and a four-stranded beta sheet; this fold was
previously identified in translation initiation factor 3 (IF3). The large domain
is similar to one of the two domains of 5-enolpyruvylshikimate-3-phosphate
synthase and UDP-N-acetylglucosamine enolpyruvyl transferase. The smaller domain
uses a similar secondary structure element with different topology, observed in
many other proteins such as thioredoxin. CONCLUSIONS: The fold of RNA cyclase
consists of known elements connected in a new and unique manner. Although the
active site of this enzyme could not be unambiguously assigned, it can be mapped
to a region surrounding His309, an adenylate acceptor, in which a number of amino
acids are highly conserved in the enzyme from different sources. The structure of
E. coli cyclase will be useful for interpretation of structural and mechanistic
features of this and other related enzymes.
PMID- 10673422
TI - The crystal structure of the formiminotransferase domain of formiminotransferase
cyclodeaminase: implications for substrate channeling in a bifunctional enzyme.
AB - BACKGROUND: The bifunctional enzyme formiminotransferase-cyclodeaminase (FTCD)
contains two active sites at different positions on the protein structure. The
enzyme binds a gamma-linked polyglutamylated form of the tetrahydrofolate
substrate and channels the product of the transferase reaction from the
transferase active site to the cyclodeaminase active site. Structural studies of
this bifunctional enzyme and its monofunctional domains will provide insight into
the mechanism of substrate channeling and the two catalytic reactions. RESULTS:
The crystal structure of the formiminotransferase (FT) domain of FTCD has been
determined in the presence of a product analog, folinic acid. The overall
structure shows that the FT domain comprises two subdomains that adopt a novel
alpha/beta fold. Inspection of the folinic acid binding site reveals an
electrostatic tunnel traversing the width of the molecule. The distribution of
charged residues in the tunnel provides insight into the possible mode of
substrate binding and channeling. The electron density reveals that the non
natural stereoisomer, (6R)-folinic acid, binds to the protein; this observation
suggests a mechanism for product release. In addition, a single molecule of
glycerol is bound to the enzyme and indicates a putative binding site for
formiminoglutamate. CONCLUSIONS: The structure of the FT domain in the presence
of folinic acid reveals a possible novel mechanism for substrate channeling. The
position of the folinic acid and a bound glycerol molecule near to the sidechain
of His82 suggests that this residue may act as the catalytic base required for
the formiminotransferase mechanism.
PMID- 10673423
TI - The high-resolution structure of the NADP(H)-binding component (dIII) of proton
translocating transhydrogenase from human heart mitochondria.
AB - BACKGROUND: Transhydrogenase, located in the inner membranes of animal
mitochondria and the cytoplasmic membranes of bacteria, couples the transfer of
reducing equivalents between NAD(H) and NADP(H) to proton pumping. The protein
comprises three subunits termed dI, dII and dIII. The dII component spans the
membrane. The dI component, which contains the binding site for NAD(+)/NADH, and
the dIII component, which has the binding site for NADP(+)/NADPH, protrude from
the membrane. Proton pumping is probably coupled to changes in the binding
affinities of dIII for NADP(+) and NADPH. RESULTS: The first X-ray structure of
the NADP(H)-binding component, dIII, of human heart transhydrogenase is described
here at 2.0 A resolution. It comprises a single domain resembling the classical
Rossmann fold, but NADP(+) binds to dIII with a reversed orientation. The first
betaalphabetaalphabeta motif of dIII contains a Gly-X-Gly-X-X-Ala/Val
'fingerprint', but it has a different function to that in the classical Rossmann
structure. The nicotinamide ring of NADP(+) is located on a ridge where it is
exposed to interaction with NADH on the dI subunit. Two distinctive features of
the dIII structure are helix D/loop D, which projects from the beta sheet, and
loop E, which forms a 'lid' over the bound NADP(+). CONCLUSIONS: Helix D/loop D
interacts with the bound nucleotide and loop E, and probably interacts with the
membrane-spanning dII. Changes in ionisation and conformation in helix D/loop D,
resulting from proton translocation through dII, are thought to be responsible
for the changes in affinity of dIII for NADP(+) and NADPH that drive the
reaction.
PMID- 10673424
TI - Mapping the binding site for the GTP-binding protein Rac-1 on its inhibitor
RhoGDI-1.
AB - BACKGROUND: Members of the Rho family of small GTP-binding proteins, such as Rho,
Rac and Cdc42, have a role in a wide range of cell responses. These proteins
function as molecular switches by virtue of a conformational change between the
GTP-bound (active) and GDP-bound (inactive) forms. In addition, most members of
the Rho and Rac subfamilies cycle between the cytosol and membrane. The cytosolic
guanine nucleotide dissociation inhibitors, RhoGDIs, regulate both the GDP/GTP
exchange cycle and the membrane association/dissociation cycle. RESULTS: We have
used NMR spectroscopy and site-directed mutagenesis to identify the regions of
human RhoGDI-1 that are involved in binding Rac-1. The results emphasise the
importance of the flexible regions of both proteins in the interaction. At least
one specific region (residues 46-57) of the flexible N-terminal domain of RhoGDI,
which has a tendency to form an amphipathic helix in the free protein, makes a
major contribution to the binding energy of the complex. In addition, the primary
site of Rac-1 binding on the folded domain of RhoGDI involves the beta4-beta5 and
beta6-beta7 loops, with a slight movement of the 3(10) helix accompanying the
interaction. This binding site is on the same face of the protein as the binding
site for the isoprenyl group of post-translationally modified Rac-1, but is
distinct from this site. CONCLUSIONS: Isoprenylated Rac-1 appears to interact
with three distinct sites on RhoGDI. The isoprenyl group attached to the C
terminus of Rac-1 binds in a pocket in the folded domain of RhoGDI. This is
distinct from the major site on this domain occupied by Rac-1 itself, which
involves two loops at the opposite end to the isoprenyl-binding site. It is
probable that the flexible C-terminal region of Rac-1 extends from the site at
which Rac-1 contacts the folded domain of RhoGDI to allow the isoprenyl group to
bind in the pocket at the other end of the RhoGDI molecule. Finally, the flexible
N terminus of RhoGDI-1, and particularly residues 48-58, makes a specific
interaction with Rac-1 which contributes substantially to the binding affinity.
PMID- 10673425
TI - Novel fold and assembly of the repetitive B region of the Staphylococcus aureus
collagen-binding surface protein.
AB - BACKGROUND: [corrected] The Staphylococcus aureus collagen-binding protein Cna
mediates bacterial adherence to collagen. The primary sequence of Cna has a non
repetitive collagen-binding A region, followed by the repetitive B region. The B
region has one to four 23 kDa repeat units (B(1)-B(4)), depending on the strain
of origin. The affinity of the A region for collagen is independent of the B
region. However, the B repeat units have been suggested to serve as a 'stalk'
that projects the A region from the bacterial surface and thus facilitate
bacterial adherence to collagen. To understand the biological role of these B
region repeats we determined their three-dimensional structure. RESULTS: B(1) has
two domains (D(1) and D(2)) placed side-by-side. D(1) and D(2) have similar
secondary structure and exhibit a unique fold that resembles but is the inverse
of the immunoglobulin-like (IgG-like) domains. Comparison with similar
immunoglobulin superfamily (IgSF) structures shows novel packing arrangements
between the D(1) and D(2) domains. In the B(1)B(2) crystal structure, an omission
of a single glycine residue in the D(2)-D(3) linker loop, compared to the D(1)
D(2) and D(3)-D(4) linker loops, resulted in projection of the D(3) and D(4) in a
spatially new orientation. We also present a model for B(1)B(2)B(3)B(4).
CONCLUSIONS: The B region of the Cna collagen adhesin has a novel fold that is
reminiscent of but is inverse in nature to the IgG fold. This B region assembly
could effectively provide the needed flexibility and stability for presenting the
ligand binding A region away from the bacterial cell surface.
PMID- 10673426
TI - The structure of TolB, an essential component of the tol-dependent translocation
system, and its protein-protein interaction with the translocation domain of
colicin E9.
AB - BACKGROUND: E colicin proteins have three functional domains, each of which is
implicated in one of the stages of killing Escherichia coli cells: receptor
binding, translocation and cytotoxicity. The central (R) domain is responsible
for receptor-binding activity whereas the N-terminal (T) domain mediates
translocation, the process by which the C-terminal cytotoxic domain is
transported from the receptor to the site of its cytotoxicity. The translocation
of enzymatic E colicins like colicin E9 is dependent upon TolB but the details of
the process are not known. RESULTS: We have demonstrated a protein-protein
interaction between the T domain of colicin E9 and TolB, an essential component
of the tol-dependent translocation system in E. coli, using the yeast two-hybrid
system. The crystal structure of TolB, a procaryotic tryptophan-aspartate (WD)
repeat protein, reveals an N-terminal alpha + beta domain based on a five
stranded mixed beta sheet and a C-terminal six-bladed beta-propeller domain.
CONCLUSIONS: The results suggest that the TolB-box residues of the T domain of
colicin E9 interact with the beta-propeller domain of TolB. The protein-protein
interactions of other beta-propeller-containing proteins, the yeast yPrp4 protein
and G proteins, are mediated by the loops or outer sheets of the propeller
blades. The determination of the three-dimensional structure of the T domain-TolB
complex and the isolation of mutations in TolB that abolish the interaction with
the T domain will reveal fine details of the protein-protein interaction of TolB
and the T domain of E colicins.
PMID- 10673427
TI - Characterization of the unfolding pathway of the cell-cycle protein p13suc1 by
molecular dynamics simulations: implications for domain swapping.
AB - BACKGROUND: The p13suc1 gene product is a member of the cks (cyclin-dependent
protein kinase subunit) protein family and has been implicated in regulation of
the cell cycle. Various crystal structures of suc1 are available, including a
globular, monomeric form and a beta-strand exchanged dimer. It has been suggested
that conversions between these forms, and perhaps others, may be important in the
regulation of the cell cycle. RESULTS: We have undertaken molecular dynamics
simulations of protein unfolding to investigate the conformational properties of
suc1. Unfolding transition states were identified for each of four simulations.
These states contain some native secondary structure, primarily helix alpha1 and
the core of the beta sheet. The hydrophobic core is loosely packed. Further
unfolding leads to an intermediate state that is slightly more expanded than the
transition state, but with considerably fewer nonlocal, tertiary packing contacts
and less secondary structure. The helices are fluctuating but partially formed in
the denatured state and beta2 and beta4 remain associated. CONCLUSIONS: It
appears that suc1 folds by a nucleation-condensation mechanism, similar to that
observed for two-state folding proteins. However, suc1 forms an intermediate
during unfolding and contains considerable residual structure in the denatured
state. The stability of the beta2-beta4 residual structure is surprising, because
beta4 is the strand involved in domain swapping. This stability suggests that the
domain-swapping event, if physiologically relevant, may require the assistance of
additional factors in vivo or occur early in the folding process.
PMID- 10673428
TI - A new scaffold for binding haem in the cytochrome domain of the extracellular
flavocytochrome cellobiose dehydrogenase.
AB - BACKGROUND: The fungal oxidoreductase cellobiose dehydrogenase (CDH) degrades
both lignin and cellulose, and is the only known extracellular flavocytochrome.
This haemoflavoenzyme has a multidomain organisation with a b-type cytochrome
domain linked to a large flavodehydrogenase domain. The two domains can be
separated proteolytically to yield a functional cytochrome and a
flavodehydrogenase. Here, we report the crystal structure of the cytochrome
domain of CDH. RESULTS: The crystal structure of the b-type cytochrome domain of
CDH from the wood-degrading fungus Phanerochaete chrysosporium has been
determined at 1.9 A resolution using multiple isomorphous replacement including
anomalous scattering information. Three models of the cytochrome have been
refined: the in vitro prepared cytochrome in its redox-inactive state (pH 7.5)
and redox-active state (pH 4.6), as well as the naturally occurring cytochrome
fragment. CONCLUSIONS: The 190-residue long cytochrome domain of CDH folds as a
beta sandwich with the topology of the antibody Fab V(H) domain. The haem iron is
ligated by Met65 and His163, which confirms previous results from spectroscopic
studies. This is only the second example of a b-type cytochrome with this
ligation, the first being cytochrome b(562). The haem-propionate groups are
surface exposed and, therefore, might play a role in the association between the
cytochrome and flavoprotein domain, and in interdomain electron transfer. There
are no large differences in overall structure of the cytochrome at redox-active
pH as compared with the inactive form, which excludes the possibility that pH
dependent redox inactivation results from partial denaturation. From the electron
density map of the naturally occurring cytochrome, we conclude that it
corresponds to the proteolytically prepared cytochrome domain.
PMID- 10673429
TI - Structures of human dihydroorotate dehydrogenase in complex with
antiproliferative agents.
AB - BACKGROUND: Dihydroorotate dehydrogenase (DHODH) catalyzes the fourth committed
step in the de novo biosynthesis of pyrimidines. As rapidly proliferating human T
cells have an exceptional requirement for de novo pyrimidine biosynthesis, small
molecule DHODH inhibitors constitute an attractive therapeutic approach to
autoimmune diseases, immunosuppression, and cancer. Neither the structure of
human DHODH nor any member of its family was known. RESULTS: The high-resolution
crystal structures of human DHODH in complex with two different inhibitors have
been solved. The initial set of phases was obtained using multiwavelength
anomalous diffraction phasing with selenomethionine-containing DHODH. The
structures have been refined to crystallographic R factors of 16.8% and 16.2% at
resolutions of 1. 6 A and 1.8 A for inhibitors related to brequinar and
leflunomide, respectively. CONCLUSIONS: Human DHODH has two domains: an
alpha/beta-barrel domain containing the active site and an alpha-helical domain
that forms the opening of a tunnel leading to the active site. Both inhibitors
share a common binding site in this tunnel, and differences in the binding region
govern drug sensitivity or resistance. The active site of human DHODH is
generally similar to that of the previously reported bacterial active site. The
greatest differences are that the catalytic base removing the proton from
dihydroorotate is a serine rather than a cysteine, and that packing of the flavin
mononucleotide in its binding site is tighter.
PMID- 10673430
TI - The manifold of vitamin B6 dependent enzymes.
AB - Pyridoxal-5'-phosphate (vitamin B6) binding enzymes form a large superfamily that
contains at least five different folds. The availability of an increasing number
of known three-dimensional structures for members of this superfamily has allowed
a detailed structural classification. Most progress has been made with the fold
type I or aspartate aminotransferase family.
PMID- 10673431
TI - The folding pathway of the cell-cycle regulatory protein p13suc1: clues for the
mechanism of domain swapping.
AB - BACKGROUND: The 113-residue alpha+beta protein suc1 is a member of the cyclin
dependent kinase subunit (cks) family of proteins that are involved in regulation
of the eukaryotic cell cycle. In vitro, suc1 undergoes domain swapping to form a
dimer by the exchange of a C-terminal beta strand. We have analysed the folding
pathway of suc1 in order to determine the atomic details of how strand-exchange
occurs in vitro and thereby obtain clues as to the possible mechanism and
functional role of dimerisation in vivo. RESULTS: The structures of the rate
determining transition state for the folding/unfolding of suc1 and of the
intermediate that is populated during refolding were probed using phi values
determined for 57 mutants with substitutions at 43 sites throughout the protein.
The majority of phi values are fractional in the intermediate and transition
state, indicating that interactions build up in a concerted manner during
folding. In the transition state, phi values of greater than 0.5 are clustered
around the inner strands beta2 and beta4 of the beta sheet. This part of the
structure constitutes the nucleus for folding according to a nucleation
condensation mechanism. Molecular dynamics simulations of unfolding of suc1,
performed independently in a blind manner, are in excellent agreement with
experiment (proceeding paper). CONCLUSIONS: Strand beta4 is the exchanging strand
in the dimer and yet it forms an integral part of the folding nucleus. This
suggests that association is an early event in the folding reaction of the dimer.
Therefore, interchange between the monomer and dimer must occur via an unfolded
state, a process that may be facilitated in vivo by accessory proteins.
PMID- 10673432
TI - Structural and kinetic analysis of Escherichia coli GDP-mannose 4,6 dehydratase
provides insights into the enzyme's catalytic mechanism and regulation by GDP
fucose.
AB - BACKGROUND: GDP-mannose 4,6 dehydratase (GMD) catalyzes the conversion of GDP-(D)
mannose to GDP-4-keto, 6-deoxy-(D)-mannose. This is the first and regulatory step
in the de novo biosynthesis of GDP-(L)-fucose. Fucose forms part of a number of
glycoconjugates, including the ABO blood groups and the selectin ligand sialyl
Lewis X. Defects in GDP-fucose metabolism have been linked to leukocyte adhesion
deficiency type II (LADII). RESULTS: The structure of the GDP-mannose 4,6
dehydratase apo enzyme has been determined and refined using data to 2.3 A
resolution. GMD is a homodimeric protein with each monomer composed of two
domains. The larger N-terminal domain binds the NADP(H) cofactor in a classical
Rossmann fold and the C-terminal domain harbors the sugar-nucleotide binding
site. We have determined the GMD dissociation constants for NADP, NADPH and GDP
mannose. Each GMD monomer binds one cofactor and one substrate molecule,
suggesting that both subunits are catalytically competent. GDP-fucose acts as a
competitive inhibitor, suggesting that it binds to the same site as GDP-mannose,
providing a mechanism for the feedback inhibition of fucose biosynthesis.
CONCLUSIONS: The X-ray structure of GMD reveals that it is a member of the short
chain dehydrogenase/reductase (SDR) family of proteins. We have modeled the
binding of NADP and GDP-mannose to the enzyme and mutated four of the active-site
residues to determine their function. The combined modeling and mutagenesis data
suggests that at position 133 threonine substitutes serine as part of the serine
tyrosine-lysine catalytic triad common to the SDR family and Glu 135 functions as
an active-site base.
PMID- 10673433
TI - The in situ conformation and axial location of the intermolecular cross-linked
non-helical telopeptides of type I collagen.
AB - BACKGROUND: Type I collagen contains specific lysine and hydroxylysine residues
that are critical in the formation of intermolecular cross-links crucial for the
normal configuration and stability of the 67 nm axial repeat of collagen fibrils
in the extracellular matrix. The major cross-linkage sites are believed to occur
between the non-helical terminal regions (telopeptides) and helical segments of
adjacent collagen molecules. In this X-ray fibre diffraction study the tissue has
been maintained in the hydrated fibrillar state, whilst detailed structural
information was obtained using highly collimated synchrotron radiation. RESULTS:
The axial component of the X-ray diffraction patterns extends more than twice as
far in reciprocal space than that of any already published. The structure-factor
phases were calculated using the multiple isomorphous addition method, avoiding
model-based approaches, and produced an electron-density profile of the molecular
arrangement projected on to the fibre axis to 0.54 nm resolution. This
corresponds to the phasing of 124 orders of the meridional diffraction pattern.
CONCLUSIONS: The axially projected electron-density profile and the electron
density difference maps showed that both the N- and C-terminal telopeptides are
contracted structures. This profile puts narrow constraints on the possible
conformations of the C-terminal telopeptide; the best fit to the electron-density
profile is when the alpha1 chains adopt a folded conformation with a sharp
hairpin turn around residues 13 and 14 of the 25-residue telopeptide. Our results
reveal for the first time the location, parallel to the fibril axis, of the
intermolecular cross-links in normal hydrated tissue. These cross-links are
essential for the biological function of the tissue.
PMID- 10673434
TI - The basis for K-Ras4B binding specificity to protein farnesyltransferase revealed
by 2 A resolution ternary complex structures.
AB - BACKGROUND: The protein farnesyltransferase (FTase) catalyzes addition of the
hydrophobic farnesyl isoprenoid to a cysteine residue fourth from the C terminus
of several protein acceptors that are essential for cellular signal transduction
such as Ras and Rho. This addition is necessary for the biological function of
the modified proteins. The majority of Ras-related human cancers are associated
with oncogenic variants of K-RasB, which is the highest affinity natural
substrate of FTase. Inhibition of FTase causes regression of Ras-mediated tumors
in animal models. RESULTS: We present four ternary complexes of rat FTase co
crystallized with farnesyl diphosphate analogs and K-Ras4B peptide substrates.
The Ca(1)a(2)X portion of the peptide substrate binds in an extended conformation
in the hydrophobic cavity of FTase and coordinates the active site zinc ion.
These complexes offer the first view of the polybasic region of the K-Ras4B
peptide substrate, which confers the major enhancement of affinity of this
substrate. The polybasic region forms a type I beta turn and binds along the rim
of the hydrophobic cavity. Removal of the catalytically essential zinc ion
results in a dramatically different peptide conformation in which the Ca(1)a(2)X
motif adopts a beta turn. A manganese ion binds to the diphosphate mimic of the
farnesyl diphosphate analog. CONCLUSIONS: These ternary complexes provide new
insight into the molecular basis of peptide substrate specificity, and further
define the roles of zinc and magnesium in the prenyltransferase reaction. Zinc is
essential for productive Ca(1)a(2)X peptide binding, suggesting that the beta
turn conformation identified in previous nuclear magnetic resonance (NMR) studies
reflects a state in which the cysteine is not coordinated to the zinc ion. The
structural information presented here should facilitate structure-based design
and optimization of inhibitors of Ca(1)a(2)X protein prenyltransferases.
PMID- 10673435
TI - The 2.0 A crystal structure of Thermus thermophilus methionyl-tRNA synthetase
reveals two RNA-binding modules.
AB - BACKGROUND: The 20 aminoacyl-tRNA synthetases are divided into two classes, I and
II. The 10 class I synthetases are considered to have in common the catalytic
domain structure based on the Rossmann fold, which is totally different from the
class II catalytic domain structure. The class I synthetases are further divided
into three subclasses, a, b and c, according to sequence homology. No conserved
structural features for tRNA recognition by class I synthetases have been
established. RESULTS: We determined the crystal structure of the class Ia
methionyl-tRNA synthetase (MetRS) at 2.0 A resolution, using MetRS from an
extreme thermophile, Thermus thermophilus HB8. The T. thermophilus MetRS
structure is in full agreement with the biochemical and genetic data from
Escherichia coli MetRS. The conserved 'anticodon-binding' residues are spatially
clustered on an alpha-helix-bundle domain. The Rossmann-fold and anticodon
binding domains are connected by a beta-alpha-alpha-beta-alpha topology ('SC
fold') domain that contains the class I specific KMSKS motif. CONCLUSIONS: The
alpha-helix-bundle domain identified in the MetRS structure is the signature of
the class Ia enzymes, as it was also identified in the class Ia structures of the
isoleucyl- and arginyl-tRNA synthetases. The beta-alpha-alpha-beta-alpha topology
domain, which can now be identified in all known structures of the class Ia and
Ib synthetases, is likely to dock with the inner side of the L-shaped tRNA,
thereby positioning the anticodon stem.
PMID- 10673436
TI - Structural basis of the Ca(2+)-dependent association between S100C (S100A11) and
its target, the N-terminal part of annexin I.
AB - BACKGROUND: S100C (S100A11) is a member of the S100 calcium-binding protein
family, the function of which is not yet entirely clear, but may include
cytoskeleton assembly and dynamics. S100 proteins consist of two EF-hand calcium
binding motifs, connected by a flexible loop. Like several other members of the
family, S100C forms a homodimer. A number of S100 proteins form complexes with
annexins, another family of calcium-binding proteins that also bind to
phospholipids. Structural studies have been undertaken to understand the basis of
these interactions. RESULTS: We have solved the crystal structure of a complex of
calcium-loaded S100C with a synthetic peptide that corresponds to the first 14
residues of the annexin I N terminus at 2.3 A resolution. We find a stoichiometry
of one peptide per S100C monomer, the entire complex structure consisting of two
peptides per S100C dimer. Each peptide, however, interacts with both monomers of
the S100C dimer. The two S100C molecules of the dimer are linked by a disulphide
bridge. The structure is surprisingly close to that of the p11-annexin II N
terminal peptide complex solved previously. We have performed competition
experiments to try to understand the specificity of the S100-annexin interaction.
CONCLUSIONS: By solving the structure of a second annexin N terminus-S100 protein
complex, we confirmed a novel mode of interaction of S100 proteins with their
target peptides; there is a one-to-one stoichiometry, where the dimeric structure
of the S100 protein is, nevertheless, essential for complex formation. Our
structure can provide a model for a Ca(2+)-regulated annexin I-S100C
heterotetramer, possibly involved in crosslinking membrane surfaces or organising
membranes during certain fusion events.
PMID- 10673437
TI - The 1.8 A crystal structure and active-site architecture of beta-ketoacyl-acyl
carrier protein synthase III (FabH) from escherichia coli.
AB - BACKGROUND: beta-Ketoacyl-acyl carrier protein synthase III (FabH) initiates
elongation in type II fatty acid synthase systems found in bacteria and plants.
FabH is a ubiquitous component of the type II system and is positioned ideally in
the pathway to control the production of fatty acids. The elucidation of the
structure of FabH is important for the understanding of its regulation by
feedback inhibition and its interaction with drugs. Although the structures of
two related condensing enzymes are known, the roles of the active-site residues
have not been experimentally tested. RESULTS: The 1.8 A crystal structure of FabH
was determined using a 12-site selenium multiwavelength anomalous dispersion
experiment. The active site (Cys112, His244 and Asn274) is formed by the
convergence of two alpha helices and is accessed via a narrow hydrophobic tunnel.
Hydrogen-bonding networks that include two tightly bound water molecules fix the
positions of His244 and Asn274, which are critical for the decarboxylation and
condensation reactions. Surprisingly, the His244-->Ala mutation does not affect
the transacylation reaction suggesting that His244 has only a minor influence on
the nucleophilicity of Cys112. CONCLUSIONS: The histidine and asparagine active
site residues are both required for the decarboxylation step in the condensation
reaction. The nucleophilicity of the active-site cysteine is enhanced by the
alpha-helix dipole effect, and an oxyanion hole promotes the formation of the
tetrahedral transition state.
PMID- 10673438
TI - The structure of adenylosuccinate lyase, an enzyme with dual activity in the de
novo purine biosynthetic pathway.
AB - BACKGROUND: Adenylosuccinate lyase is an enzyme that plays a critical role in
both cellular replication and metabolism via its action in the de novo purine
biosynthetic pathway. Adenylosuccinate lyase is the only enzyme in this pathway
to catalyze two separate reactions, enabling it to participate in the addition of
a nitrogen at two different positions in adenosine monophosphate. Both reactions
catalyzed by adenylosuccinate lyase involve the beta-elimination of fumarate.
Enzymes that catalyze this type of reaction belong to a superfamily, the members
of which are homotetramers. Because adenylosuccinate lyase plays an integral part
in maintaining proper cellular metabolism, mutations in the human enzyme can have
severe clinical consequences, including mental retardation with autistic
features. RESULTS: The 1.8 A crystal structure of adenylosuccinate lyase from
Thermotoga maritima has been determined by multiwavelength anomalous dispersion
using the selenomethionine-substituted enzyme. The fold of the monomer is
reminiscent of other members of the beta-elimination superfamily. However, its
active tetrameric form exhibits striking differences in active-site architecture
and cleft size. CONCLUSIONS: This first structure of an adenylosuccinate lyase
reveals that, along with the catalytic base (His141) and the catalytic acid
(His68), Gln212 and Asn270 might play a vital role in catalysis by properly
orienting the succinyl moiety of the substrates. We propose a model for the dual
activity of adenylosuccinate lyase: a single 180 degrees bond rotation must occur
in the substrate between the first and second enzymatic reactions. Modeling of
the pathogenic human S413P mutation indicates that the mutation destabilizes the
enzyme by disrupting the C-terminal extension.
PMID- 10673439
TI - Structure of Aspergillus niger epoxide hydrolase at 1.8 A resolution:
implications for the structure and function of the mammalian microsomal class of
epoxide hydrolases.
AB - BACKGROUND: Epoxide hydrolases have important roles in the defense of cells
against potentially harmful epoxides. Conversion of epoxides into less toxic and
more easily excreted diols is a universally successful strategy. A number of
microorganisms employ the same chemistry to process epoxides for use as carbon
sources. RESULTS: The X-ray structure of the epoxide hydrolase from Aspergillus
niger was determined at 3.5 A resolution using the multiwavelength anomalous
dispersion (MAD) method, and then refined at 1.8 A resolution. There is a dimer
consisting of two 44 kDa subunits in the asymmetric unit. Each subunit consists
of an alpha/beta hydrolase fold, and a primarily helical lid over the active
site. The dimer interface includes lid-lid interactions as well as contributions
from an N-terminal meander. The active site contains a classical catalytic triad,
and two tyrosines and a glutamic acid residue that are likely to assist in
catalysis. CONCLUSIONS: The Aspergillus enzyme provides the first structure of an
epoxide hydrolase with strong relationships to the most important enzyme of human
epoxide metabolism, the microsomal epoxide hydrolase. Differences in active-site
residues, especially in components that assist in epoxide ring opening and
hydrolysis of the enzyme-substrate intermediate, might explain why the fungal
enzyme attains the greater speeds necessary for an effective metabolic enzyme.
The N-terminal domain that is characteristic of microsomal epoxide hydrolases
corresponds to a meander that is critical for dimer formation in the Aspergillus
enzyme.
PMID- 10673440
TI - The atomic-resolution structure of a novel bacterial esterase.
AB - BACKGROUND: A novel bacterial esterase that cleaves esters on halogenated cyclic
compounds has been isolated from an Alcaligenes species. This esterase 713 is
encoded by a 1062 base pair gene. The presence of a leader sequence of 27 amino
acids suggests that this enzyme is exported from the cytosol. Esterase 713 has
been over-expressed in Agrobacterium without this leader sequence. Its amino acid
sequence shows no significant homology to any known protein sequence. RESULTS:
The crystal structure of esterase 713 has been determined by multiple isomorphous
replacement and refined to 1. 1 A resolution. The subunits of this dimeric enzyme
comprise a single domain with an alpha/beta hydrolase fold. The catalytic triad
has been identified as Ser206-His298-Glu230. The acidic residue of the catalytic
triad (Glu230) is located on the beta6 strand of the alpha/beta hydrolase fold,
whereas most other alpha/beta hydrolase enzymes have the acidic residue located
on the beta7 strand. The oxyanion hole is formed by the mainchain nitrogens of
Cys71 and Gln207 as identified by the binding of a substrate analogue, (S)-7-iodo
2,3,4,5-tetrahydro-4-methyl-3-oxo-1H-1, 4-benzodiazepine-2-acetic acid. Cys71
forms a disulphide bond with the neighbouring Cys72. CONCLUSIONS: Despite
negligible sequence homology, esterase 713 has structural similarities to a
number of other esterases and lipases. Residues of the oxyanion hole were
confirmed by structural comparison with Rhizomucor miehei lipase. It is proposed
that completion of a functional active site requires the formation of the
disulphide bond between adjacent residues Cys71 and Cys72 on export of the
esterase into the oxidising environment of the periplasmic space.
PMID- 10673441
TI - Phospholipase A(2) enzymes: structural diversity in lipid messenger metabolism.
AB - The phospholipases A(2) (PLA(2)s) are a large family of enzymes with varied
lipidic products which are involved in numerous signal transduction pathways. The
structural and functional characterization of several PLA(2)s have revealed the
various mechanisms used by these enzymes to ingeniously manipulate the
phospholipidic metabolic machinery.
PMID- 10673442
TI - A new variant of the Ntn hydrolase fold revealed by the crystal structure of L
aminopeptidase D-ala-esterase/amidase from Ochrobactrum anthropi.
AB - BACKGROUND: The L-aminopeptidase D-Ala-esterase/amidase from Ochrobactrum
anthropi (DmpA) releases the N-terminal L and/or D-Ala residues from peptide
substrates. This is the only known enzyme to liberate N-terminal amino acids with
both D and L stereospecificity. The DmpA active form is an alphabeta heterodimer,
which results from a putative autocatalytic cleavage of an inactive precursor
polypeptide. RESULTS: The crystal structure of the enzyme has been determined to
1.82 A resolution using the multiple isomorphous replacement method. The
heterodimer folds into a single domain organised as an alphabetabetaalpha
sandwich in which two mixed beta sheets are flanked on both sides by two alpha
helices. CONCLUSIONS: DmpA shows no similarity to other known aminopeptidases in
either fold or catalytic mechanism, and thus represents the first example of a
novel family of aminopeptidases. The protein fold of DmpA does, however, show
structural homology to members of the N-terminal nucleophile (Ntn) hydrolase
superfamily. DmpA presents functionally equivalent residues in the catalytic
centre when compared with other Ntn hydrolases, and is therefore likely to use
the same catalytic mechanism. In spite of this homology, the direction and
connectivity of the secondary structure elements differ significantly from the
consensus Ntn hydrolase topology. The DmpA structure thus characterises a new
subfamily, but supports the common catalytic mechanism for these enzymes
suggesting an evolutionary relationship.
PMID- 10673443
TI - Simple redox-linked proton-transfer design: new insights from structures of
quinol-fumarate reductase.
AB - The mitochondrial bioenergetics field has experienced an exciting breakthrough
with the recent structure determination of several key membrane complexes. The
latest addition to this line of structures, that of quinol-fumarate reductase,
provides new insights into the mechanism of energy transduction.
PMID- 10673444
TI - Giant solitary trichoepithelioma.
AB - The giant solitary trichoepithelioma is a rare trichogenic tumor with potential
for local recurrence. Only nine cases have been previously described in the
literature, and one additional case without recurrence during the first 3.5 years
of observation is presented stressing that the rate of recurrence is low.
PMID- 10673445
TI - Pigmented purpuric dermatosis (Schamberg's purpura) in an infant.
AB - Purpura in an infant is usually an alarming sign of a systemic (infectious,
hematologic-oncologic or immunologic) disease. Chronic purpuric dermatoses have
not been reported in infants and, therefore, are not considered in the
differential diagnosis of purpuras in this age. We report on a female infant with
progressive purpura who underwent extensive laboratory investigations to rule out
a systemic disease. Based on the laboratory findings and clinical course, the
diagnosis of Schamberg's purpura was established.
PMID- 10673446
TI - Hereditary hypodontia and onychorrhexis of the fingernails and toenail
koilonychia: Witkop's tooth-and nail syndrome.
AB - The tooth-and-nail syndrome (Witkop's syndrome) is a rare autosomal dominant
ectodermal dysplasia manifest by defects of the nail plates of the fingers and
toes and hypodontia with normal hair and sweat gland function. We report a
thirteen year-old girl who presented with marked longitudinal ridging of the nail
plates of all ten fingers. The toenails were mildly ridged with koilonychia. Her
mother's fingers were similarly affected to a lesser degree while her toenails
appeared normal. Examination of the child's dentition revealed a hyperplastic
frenulum and the absence of one of the usual four mandibular incisors. History
provided by the mother described the maternal grandmother and maternal great aunt
as having identical nail findings and the presence of only three lower incisors.
Hair examination was normal in the mother and child, and no history or findings
of sweat gland dysfunction was present. This report describes familial
hypodontia, fingernail onychorrhexis, and toenail koilonychia consistent with
Witkop's syndrome.
PMID- 10673447
TI - Long-standing translucent tumor on the groin. Diagnosis: mucinous carcinoma of
the skin.
PMID- 10673448
TI - Benign lymphoepithelial tumor of the skin ("cutaneous lymphadenoma").
AB - "Benign lymphoepithelial tumor of the skin" or "cutaneous lymphadenoma" is a
distinctive benign adnexal tumor presenting a characteristic combination of
lobules of epithelial basaloid cells with a peculiar histopathological pattern
and a dense intraepithelial T-cell lymphoid and histiocytic population. We report
an additional example of this peculiar neoplasm. In addition to the
characteristic histopathological features, focal areas showing unequivocal
follicular differentiation were observed at the periphery of the tumor. In
agreement with other authors we consider that this neoplasm should be included
within the spectrum of neoplasms of pilosebaceous origin. Nevertheless, we
consider that the original and simple concept of "benign lymphoepithelial tumor
of the skin" seems more suitable and illustrative than the more widely used term
of "cutaneous lymphadenoma" to define this rare benign adnexal neoplasm.
PMID- 10673449
TI - Cimex lectularius. What is this insect and how does it affect man?
AB - Cimex lectularius, the common bed bug, is a bloodsucking nocturnal parasite of
man. Other hosts for this bug include chickens, bats, and some domestic animals.
Cimex feeds by piercing the host with hollow tubes derived from the maxilla.
Saliva injected at the time of feeding is associated with local and sometimes
widespread urticaria. This pest has become less important over the last half
century with general improvements in household and personal cleanliness.
PMID- 10673450
TI - Delayed type hypersensitivity: current theories with an historic perspective.
AB - Although the delayed type hypersensitivity (DTH) reaction was discovered over 100
years ago, the exact nature of the reaction has been the subject of contentious
debate over the years. The reaction was discovered in 1882 by Robert Koch, but it
was not until the 1940s that Landsteiner and Chase proved that the reaction was
mediated by the cellular and not the humoral arm of the immune system. The first
DTH reaction described used only the tuberculin antigen (tuberculin reaction),
but the definition was later expanded to include cell mediated reactions to other
bacterial and viral antigens, responses to pure protein with adjuvant or haptens,
and host responses to allograft. The DTH skin test is used to test if prior
exposure to an antigen has occurred. When small quantities of antigen are
injected dermally, a hallmark response is elicited which includes induration,
swelling and monocytic infiltration into the site of the lesion within 24 to 72
hours. This reaction has been shown to be absolutely dependent on the presence of
memory T cells. Both the CD4+ and CD8+ fractions of cells have been shown to
modulate a response. Contemporary debate regarding the reaction is focused on the
role of the Th1 and Th2 cells originally discovered by Mosmann. It has been
postulated that the Th1 cell is the "inducer" of a DTH response since it secretes
interferon gamma (IFN ), a potent stimulator of macrophages, while the Th2 cell
is either not involved or acting as a downregulator of the cell mediated immune
response. Despite the early experimental success of this theory, experiments have
shown that Th2 cells may be involved in certain types of proinflammatory cell
mediated immunity. This review focuses on the nature of the different forms of
DTH that can be elicited and the different experimental evidence that has led to
the current theories regarding DTH and its role in cell mediated immunity.
PMID- 10673451
TI - Sweet's syndrome (acute febrile neutrophilic dermatosis).
AB - Sweet's syndrome, or acute febrile neutrophilic dermatosis, is a condition
characterized by the sudden onset of fever, leukocytosis, and
tender,erythematous, well-demarcated papules and plaques which show dense
neutrophilic infiltrates on histologic examination. Although it ma occur in the
absence of other known disease, Sweet's syndrome is often associated with
hematologic disease (including leukemia), and immunologic disease (rheumatoid
arthritis, inflammatory bowel disease). Treatment with systemic corticosteroids
is usually successful. skin, Sweet syndrome, neutrophilic dermatosis,
corticosteroids,
PMID- 10673452
TI - Publishing dermatology therapy reviews on-line.
PMID- 10673454
TI - Insulin-like growth factor 1 and hair growth.
AB - Insulin-like growth factor 1 (IGF-1) has been identified as an important growth
factor in many biological systems.[1] It shares considerable structural homology
with insulin and exerts insulin-like effects on food intake and glucose
metabolism. Recently it has been suggested to play a role in regulating cellular
proliferation and migration during the development of hair follicles. [2,3] To
exert its biological effects, the IGF-1 is required to activate cells by binding
to specific cell-surface receptors. The type I IGF receptor (IGF-1R) is the only
IGF receptor to have IGF-mediated signaling functions.[1] In circulation, this
growth factor mediates endocrine action of growth hormone (GH) on somatic growth
and is bound to specific binding proteins (BPs). The latter control IGF
transport, efflux from vascular compartments and association with cell surface
receptors.[4] In tissues, IGF-1 is produced by mesenchymal type cells and acts in
a paracrine and autocrine fashion by binding to the IGF-1R. This binding
activates the receptor tyrosine kinase (RTK) that triggers the downstream
responses and finally stimulates cell division.[5] IGF-1 may therefore be able to
stimulate the proliferation of hair follicle cells through cellular signaling
pathways of its receptors. Local infusion of IGF-1 into sheep has been reported
to be capable of stimulating protein synthesis in the skin.[6] It may also
increase the production of wool keratin. Recently, transgenic mice overexpressing
IGF-1 in the skin have been shown to have earlier hair follicle development than
controls.[7] In addition, this growth factor plays an important role in many cell
types as a survival factor to prevent cell death.[8] This anti-apoptotic function
of IGF-1 may be important to the development of follicle cells as follicles
undergo a growth cycle where the regressive, catagen phase is apoptosis driven.
In this review, the effects of IGF-1 on follicle cell proliferation and
differentiation are discussed. In particular, the paracrine versus endocrine
action of IGF-1 on hair growth and the targeting of expression of the growth
factor to the follicles of transgenic animals will be emphasized. The anti
apoptotic role of IGF-1 in hair follicles is also reviewed. Prospects for future
studies on hair and fiber growth by IGF-1 are discussed.
PMID- 10673455
TI - Isotretinoin induced rhabdomyolysis? A case report.
AB - Isotretinoin, an effective therapy for nodulocystic acne and dissecting
cellulitis of the scalp, has many known side effects. However, its association
with elevated creatine kinase levels and its potential to cause rhabdomyolysis is
not well established. We describe a patient with a significant elevation in
creatine kinase after beginning therapy with isotretinoin for dissecting
cellulitis of the scalp. The implications of isotretinoin causing rhabdomyolysis
are discussed.
PMID- 10673456
TI - The clinical diagnosis of early malignant melanoma: expansion of the ABCD
criteria to improve diagnostic sensitivity.
AB - With the steady increase in incidence of malignant melanomas (MM) in the United
States, early diagnosis and complete removal are critical for the containment of
the malignancy. [1] The "ABCD" method of identification, originally described by
Friedman et al., has been a useful tool in facilitating the diagnosis of MM.
[2,3,4] This method analyzes four clinical characteristics to identify a
malignant melanoma: Asymmetry, Border irregularity, Color variegation, and a
Diameter of 6 mm or more.[4] Clinicians recognize that some melanomas lack all or
most of the features defined in the "ABCD" rules. [5] This may be especially true
of some early invasive and in situ melanomas. [6,7] In these instances, clinical
history documenting morphologic change over time can be an important additional
consideration. The following case reports underscore the need to expand the ABCD
mnemonic to include an "E" for "Evolutionary change." An additional modification
is also needed to emphasize the need for a low threshold for biopsy of unusual
lesions which do not show typical benign features, even if they do not meet the
ABCDE criteria. To this end we propose an "F" for "Funny looking lesions".
PMID- 10673457
TI - The relationship between biopsy technique and uncertainty in the histopathologic
diagnosis of melanoma.
AB - Review of filed histopathology material of 525 cases of definite melanomas and
other atypical pigmented lesions showed that diagnostic certainty was greatest
for excisional or deep shave specimens. Shave and particularly punch biopsy
specimens were associated with less certainty. The data of this study suggest
that punch biopsy should be avoided for pigmented lesions and that a properly
done deep shave biopsy is nearly equal to an excision in diagnostic content for
such lesions.
PMID- 10673458
TI - Mudi-chood disease.
AB - Mudi-chood disease is a distinct clinical entity seen nearly exclusively in young
women in Kerala State, India. Traditional hair grooming methods that utilize
various plant oils along with the natural environmental heat and humidity create
the conditions necessary to produce a lichenoid dermatitis on the neck and upper
back.
PMID- 10673459
TI - Genus Tabanus. Tabanids (horseflies). What is this insect and how does it affect
man?
AB - The insect family Tabanidae (Order: Diptera) comprises approximately 3000 species
of flies worldwide, including the commonly known horseflies and deerflies.
Females of most species require a blood meal to complete egg development and many
species are important in human and animal medicine. This article briefly
discusses the life cycle, biology, and medical significance of tabanids.
PMID- 10673460
TI - Identifying and misidentifying the brown recluse spider.
AB - The brown recluse spider, Loxosceles reclusa, is often implicated as a cause of
necrotic skin lesions.[1-3] Diagnoses are most commonly made by clinical
appearance and infrequently is a spider seen, captured or identified at the time
of the bite.[1, 2, 4-6] The brown recluse lives in a circumscribed area of the
U.S. (the south central Midwest) with a few less common recluse species living in
the more sparsely-populated southwest U.S.[7] In these areas, where spider
populations may be dense, recluse spiders may be a cause of significant
morbidity. However, outside the natural range of these recluse species, the
conviction that they are the etiological agents behind necrotic lesions of
unknown origin is widespread, and most often erroneous. In some states such as
California, unsubstantiated reports concerning recluse spider bites have taken on
the status of "urban legend" leading to overdiagnosis and, therefore,
inappropriate treatment.
PMID- 10673461
TI - Clinically relevant dermatology resources and the Internet: An introductory guide
for practicing physicians.
AB - The number of dermatology sites on the Internet is growing rapidly and the
resources they offer are of great benefit to dermatologists and physicians. The
mainstay of dermatologic diagnosis is that of visual inspection and gross
morphology, therefore, the use of improved imaging techniques, which allow for
the rapid collection, electronic transmission, and indexing of images aids in the
accurate recognition and interpretation of skin lesions. The graphic nature of
the field of dermatology kindly lends itself to the use of the Internet. The
enhanced ability to access information,and share expert opinion worldwide will
help lessen inappropriate treatment or delayed referral to an appropriate
specialist and facilitate the accurate diagnosis of various dermatologic
diseases. Concerns about the quality of data are examined and an evaluation
scheme proposed. An overview of available resources is presented along with links
to additional resources to aid the reader in the identification of additional
sites to explore. Sites were selected with the goal of identifying those that
provide a broad range of information worthwhile to the dermatologist and general
practitioner. Resources including, but not limited to, image atlases, electronic
texts, drug databases, case study archives, laboratory testing, and clinical
procedures are examined.
PMID- 10673462
TI - Terbinafine and lupus erythematosus a chance association?
PMID- 10673463
TI - Treatment of atopic dermatitis with zafirlukast.
PMID- 10673464
TI - Online publishing and repositories. PubMed Central vs. IASTMP.
PMID- 10673465
TI - The impact of COPD on lung health worldwide: epidemiology and incidence.
AB - Information on the prevalence of COPD was obtained from vital statistics, health
interview surveys, hospital charge records, national publications, and the World
Health Organization (WHO). These data indicate that COPD is a common disease with
implications for global health. In the United States, morbidity caused by COPD is
4%, making COPD the fourth leading cause of death, exceeded only by heart
attacks, cancer, and stroke. Internationally, there is substantial variation in
death rates possibly reflecting smoking behavior, type and processing of tobacco,
pollution, climate, respiratory management, and genetic factors. The Global
Obstructive Lung Disease Initiative, initiated by the National Heart, Lung, and
Blood Institute and the WHO, aims to raise awareness of the increasing burden of
COPD, decrease morbidity and mortality, promote further study of the condition,
and implement programs to prevent COPD.
PMID- 10673466
TI - The economic burden of COPD.
AB - COPD is one of the leading causes of morbidity and mortality worldwide and
imparts a substantial economic burden on individuals and society. Despite the
intense interest in COPD among clinicians and researchers, there is a paucity of
data on health-care utilization, costs, and social burden in this population. The
total economic costs of COPD morbidity and mortality in the United States were
estimated at $23.9 billion in 1993. Direct treatments for COPD-related illness
accounted for $14.7 billion, and the remaining $9.2 billion were indirect
morbidity and premature mortality estimated as lost future earnings. Similar data
from another US study suggest that 10% of persons with COPD account for > 70% of
all medical care costs. International studies of trends in COPD-related
hospitalization indicate that although the average length of stay has decreased
since 1972, admissions per 1,000 persons per year for COPD have increased in all
age groups > 45 years of age. These trends reflect population aging, smoking
patterns, institutional factors, and treatment practices.
PMID- 10673467
TI - Mechanisms in COPD: differences from asthma.
AB - Although considerable progress has been made in understanding the cellular and
molecular mechanisms of asthma, much less attention has been paid to COPD. The
inflammatory process in COPD is very different from that in asthma, with
different inflammatory cells, mediators, inflammatory effects, and response to
therapy. Airway inflammation in asthma, characterized by an eosinophilic
inflammation affecting all the airways but not lung parenchyma, is linked to
airway hyperresponsiveness. In COPD, there is a predominantly neutrophilic
inflammation in the airways. Parenchymal destruction is an important irreversible
feature and leads to airflow obstruction through dynamic compression. The
eosinophilic inflammation in asthma is markedly suppressed by corticosteroids,
but they have no appreciable effect on the inflammation in COPD, consistent with
a failure of long-term corticosteroids to alter the progression of COPD.
PMID- 10673468
TI - The importance of spirometry in COPD and asthma: effect on approach to
management.
AB - COPD is characterized by airflow limitation. The diagnosis is suggested by
history and physical examination and is confirmed by spirometry (ie, a low FEV(1)
level that is unresponsive to bronchodilators). Once diagnosed, there is no
widely accepted staging or severity scoring system. COPD presently is graded
using a single measurement such as FEV(1), which, unlike the case with asthma,
has a limited role in disease management. A more comprehensive staging system is
required incorporating, for example, age, arterial blood gases, dyspnea, body
mass index, and distance walked, in addition to FEV(1). These criteria should
allow for more evidence-based recommendations for management of this condition.
Asthma is an inflammatory disease also characterized by airflow limitation. But
in contrast with COPD, the airflow limitation is highly reversible either
spontaneously or with therapy. Repeated lung function measurements using portable
peak flowmeters have resulted in improved outcomes. Therefore, frequent flow
determination is recommended in the routine management of asthma. Treatment with
anti-inflammatory agents and close monitoring of lung function should help
decrease the morbidity and mortality associated with asthma.
PMID- 10673469
TI - National and international guidelines for COPD: the need for evidence.
AB - The introduction of guidelines for the management of asthma has led to
standardization of management and better care of patients with the condition.
Many national and international respiratory societies have developed guidelines
for COPD. The World Health Organization and the National Heart, Lung, and Blood
Institute are jointly developing guidelines that will present evidence-based
recommendations for the management of COPD. The guidelines will discuss the
definition, epidemiology, natural history, risk factors, pathology, and diagnosis
of COPD. There will be guidance on the management of chronic disease and acute
exacerbations, education, prevention, and socioeconomics.
PMID- 10673470
TI - Recommendations for the management of COPD.
AB - Three sets of guidelines for the management of COPD that are widely recognized
(from the European Respiratory Society [ERS], American Thoracic Society [ATS],
and British Thoracic Society [BTS]) are reviewed and compared. None of the
documents uses classic evidence-based documentation, and, in many instances, the
recommendations are empiric because of a lack of scientific evidence. Overall,
there is strong agreement between the documents. All three guidelines recommend
inhaled bronchodilators as first-line therapy. Anticholinergics are noted to be
well tolerated, although potential problems with beta(2)-agonists are mentioned.
The ERS and BTS suggest that inhaled corticosteroids may be of value in patients
documented to be steroid responders, whereas the ATS does not recommend their use
at all. All three guidelines support the use of oxygen and pulmonary
rehabilitation. There are varying levels of disagreement between the guidelines
related to the role of spirometry, stratification of disease severity, and the
use of theophylline and systemic corticosteroids. Other differences include the
role for nebulizers and metered-dose inhalers, secretion clearance methodologies,
and the treatment of acute COPD exacerbations and acute respiratory failure. All
three guidelines agree that more research is needed to improve our understanding
and management of COPD.
PMID- 10673471
TI - The reality of drug use in COPD: the European perspective.
AB - COPD guidelines provide advice about the appropriate use of various medications
in treating patients with this condition. Comparisons of drug therapy as
recommended by these guidelines with what is actually prescribed by both primary
care physicians and specialist pulmonologists in a number of European countries
can be examined in a variety of ways. Nonadherence to guidelines and differences
between countries are caused by a number of factors, including varying degrees of
misdiagnosis and different national attitudes to various classes of drugs.
PMID- 10673472
TI - Suboptimal medical therapy in COPD: exploring the causes and consequences.
AB - Effective outpatient management of COPD requires prescription of and adherence to
appropriate therapies. Although practice guidelines for outpatient management of
COPD are widely available, evidence suggests that these guidelines are not being
implemented widely in clinical practice. Furthermore, several studies have shown
that patient compliance with recommended therapy is poor. This paper discusses
several reasons why implementation of practice guidelines and adherence with
prescribed therapies may be poor. Potential clinical and economic consequences of
suboptimal management are reviewed. Although the evidence suggests that improved
compliance with guideline-recommended practice will improve symptoms and disease
specific quality of life, further work needs to be done to establish the cost
effectiveness of chronic therapies for COPD relative to other chronic conditions.
Without such data, managed care organizations will be reluctant to allocate
scarce resources toward expensive guideline implementation programs for
individuals with this condition.
PMID- 10673473
TI - How can the implementation of guidelines be improved?
AB - Guidelines for a variety of diseases have now been produced. However,
implementation of guidelines requires that the medical profession is willing to
conform to patterns of diagnostic and treatment behavior set down by others. This
may not happen in practice. Early experience in the United Kingdom was gained
with the introduction of guidelines for the management of asthma. For a number of
years, there have been improvements in practice, but deficiencies still exist.
When the introduction of guidelines for the management of COPD was planned, a new
approach was taken with a consortium of the British Thoracic Society,
pharmaceutical companies, and medical equipment companies being formed to promote
their use. Early studies show that COPD care starts from an even lower baseline
than asthma; there is poor understanding of objective diagnosis of COPD in both
primary and secondary care.
PMID- 10673474
TI - Assessment of bronchodilator efficacy in symptomatic COPD: is spirometry useful?
AB - Bronchodilator therapy in COPD is deemed successful if it improves ventilatory
mechanics to a degree where effective symptom alleviation and increased exercise
capacity are achieved. A greater understanding of the pathophysiologic mechanisms
of dyspnea and exercise intolerance in COPD has prompted a reevaluation of the
manner in which we currently assess therapeutic efficacy. The traditional
reliance on an improved postbronchodilator FEV(1) as indicative of a positive
clinical response has recognized limitations. To the extent that pharmacologic
volume reduction is a desirable therapeutic goal with favorable implications for
dyspnea relief and increased exercise tolerance, the potential value of
bronchodilator-induced changes in lung volume measurements is currently being
studied. It is unlikely, however, given the multifactorial nature of dyspnea and
exercise limitation in COPD, that resting spirometric measurements of maximal
flows and volumes alone will be sufficiently sensitive to adequately predict a
positive clinical response to bronchodilator therapy. Thus, additional direct
measurements of exercise dynamic hyperinflation and exercise endurance together
with reliable subjective measurements of dyspnea and quality of life are
recommended in the setting of a suitable placebo-controlled design.
PMID- 10673475
TI - Impact of sleep in COPD.
AB - Sleep has well-recognized effects on breathing, including changes in central
respiratory control, airways resistance, and muscular contractility, which do not
have an adverse effect in healthy individuals but may cause problems in patients
with COPD. Sleep-related hypoxemia and hypercapnia are well recognized in COPD
and are most pronounced in rapid eye movement sleep. However, sleep studies are
usually only indicated in patients with COPD when there is a possibility of sleep
apnea or when cor pulmonale and/or polycythemia are not explained by the awake
PaO(2) level. Management options for patients with sleep-related respiratory
failure include general measures such as optimizing therapy of the underlying
condition; physiotherapy and prompt treatment of infective exacerbations;
supplemental oxygen; pharmacologic treatments such as bronchodilators,
particularly ipratropium bromide, theophylline, and almitrine; and noninvasive
positive pressure ventilation.
PMID- 10673476
TI - How should health-related quality of life be assessed in patients with COPD?
AB - The traditional approach of caring for patients with chronic respiratory disease
has been to rely on pulmonary function tests to quantify the severity and to
assess response to therapy. However, patients with respiratory conditions seek
medical attention because of symptoms, particularly dyspnea, and impaired ability
to function, which clearly impact on an individual's health-related quality of
life (HRQOL). Accordingly, instruments have been developed to provide a
standardized method to measure health status and levels of impairment. One of the
major reasons for measuring HRQOL is to detect how much HRQOL has changed in
response to therapy (an evaluative instrument). A minimum clinically significant
change has been established for some HRQOL instruments in order to indicate the
relative value of any measured change and to guide the interpretation as to
whether the change is "clinically meaningful." Selected studies using disease
specific instruments have demonstrated that beta(2)-agonist, anticholinergic, and
theophylline medications can improve HRQOL, as compared with placebo therapy.
PMID- 10673477
TI - New approaches to the management of COPD.
AB - Airflow limitation in COPD is a result partially of bronchospasm, but it is also
caused by a reduction in airway caliber, the number of small airways, airway
collapse because of loss of connective tissue support, excess mucus in the
airways, and edema of the airway wall. Structural changes also occur because of
long-term destruction of interstitial connective tissue, including elastin.
Therefore, in addition to the traditional aim of reversing bronchospasm with
bronchodilators, disease-modifying approaches are being investigated. The enzyme
neutrophil elastase is implicated in the induction of bronchial disease causing
structural changes in lungs, impairment of mucociliary clearance, and impairment
of host defenses. The precise mechanism pathway of neutrophil elastase is
uncertain, but the effects of influencing the pathway in order to slow disease
progression are being investigated. Oxidants may also have a role in the
development of COPD, with increased levels activating airway cells and cytokine
production.
PMID- 10673478
TI - The pharmacological properties of tiotropium.
AB - Tiotropium is a long-acting anticholinergic drug. Studies with cloned human
muscarinic receptors show that tiotropium binds equally well to M(1), M(2), and
M(3) receptors. However, it dissociates very slowly from M(1) and M(3) receptors
compared with ipratropium, and more rapidly from M(2) receptors. Binding studies
with [(3)H]tiotropium in human lung show that it is approximately 10-fold more
potent than ipratropium. In vitro, tiotropium has a potent inhibitory effect
against cholinergic nerve-induced contraction of airways. It dissociates
extremely slowly, compared with the dissociation of atropine and ipratropium.
Clinical studies with single doses of inhaled tiotropium confirm that it is a
potent and long-lasting bronchodilator. Furthermore, it protects against
cholinergic bronchoconstriction for > 24 h. Pharmacokinetic studies show that
little of the inhaled drug is absorbed, thus predicting a high margin of safety.
PMID- 10673479
TI - The future for tiotropium.
AB - In spite of growing interest in and knowledge about the causes and progression of
COPD, neither the assessment nor pharmacologic treatment of this condition is
currently ideal. Tiotropium is the first new treatment for COPD in many years.
Tiotropium is a long-acting anticholinergic agent that has a potential role as a
once-daily maintenance treatment, and a picture of its effectiveness is gradually
emerging. Spirometry data from clinical studies demonstrate that it is a potent
bronchodilator in patients with COPD and it is very well tolerated. Further data
on health status and quality of life are awaited.
PMID- 10673480
TI - Primary care research: ends and means.
PMID- 10673481
TI - Knowledge and attitudes of primary care physicians regarding battered women.
Comparison between specialists in family medicine and GPs.
AB - BACKGROUND: Domestic violence is a widespread public health problem and an
important part of primary care practice. OBJECTIVE: To evaluate the approach of
primary care physicians (family physicians and GPs) to the care of battered
women. METHODS: A self-report questionnaire containing items about experience,
knowledge and attitudes regarding the care of battered women was mailed to a
random sample of 300 primary care physicians employed by the two major health
management organizations in Israel. The population included family physicians,
who have 4 years of residency training in primary care, and GPs, who do not
undergo specialization after completing their medical studies. RESULTS: A total
of 236 physicians (130 family physicians and 106 GPs) responded. In general, the
physicians had had very little exposure to the problem and estimated its
prevalence in the community as less than half that indicated in the medical
literature. Compared with the GPs, however, the family physicians reported more
exposure to the subject (P < 0.001) and had better knowledge of its prevalence
and risk factors (P < 0.001). They also showed a greater tendency to view the
problem as universal (P < 0.05) and as part of their professional
responsibilities. However, both groups tended not to include the care of battered
women with no physical injury within their professional duties. CONCLUSIONS:
Physicians should be made more aware of the problem of battered women within the
context of their routine professional practice and of the importance of keeping
abreast of the subject. Educators should place more emphasis on imparting
knowledge and skills in the management of battered women, especially for GPs.
PMID- 10673482
TI - The work by the developing primary care team in China: a survey in two cities.
AB - BACKGROUND: China is in the process of converting its existing primary care
resources into general practice. The infrastructure is different from that of
many other countries. OBJECTIVES: We surveyed patients' reasons for encounter
(RFE) and the health providers' diagnoses in the general practice clinics of two
large northern cities in order to assess the nature of the work of these
practices. METHOD: Practices whose staff had a short course of training in the
theory and practice of the International Classification of Primary Care (ICPC)
were recruited to document the RFE and diagnoses of patient encounters in two
separate winter weeks. RESULTS: The practices dealt mainly with chronic illness
in older patients. Hypertension-related problems were the most frequent
diagnoses, followed by upper respiratory tract infection. Patients also consulted
very frequently for dizziness. Overall, there was good agreement between RFE and
diagnosis in some organ systems. CONCLUSION: In their present form, the Chinese
practices surveyed were delivering the full range of general practice care to a
self-selected age group of patients. The ICPC was very useful for monitoring the
work of general practice from the perspective of both the patients and the
providers.
PMID- 10673483
TI - Continuity of care: towards a definition based on experiences of practising GPs.
AB - BACKGROUND: The traditional concept of continuity of care, i.e. care from the
cradle to the grave, is no longer sustainable in modern society. OBJECTIVE: The
aim of this study was to propose a definition of 'continuity of care' based on
the experiences of a group of practising Australian GPs. METHOD: Five focus group
discussions were conducted to explore the understanding and practice of
continuity of care, the individual's measurement of having achieved continuity of
care in his/her practice and the advantages/disadvantages of providing continuity
of care. Results and conclusions. The experiences of this group of GPs points
towards three essential aspects to help with a definition of continuity of care.
Firstly it requires a stable care environment, secondly good communication to
build a responsible doctor-patient relationship and thirdly the goal of achieving
an improvement of the patient's overall health.
PMID- 10673484
TI - Patient perception of quality following a visit to a doctor in a primary care
unit.
AB - BACKGROUND: Assessment of the quality of primary care services may be enhanced by
including patient perceptions as well as professional judgment of quality. There
is a need for reliable and valid instruments to measure these perceptions.
OBJECTIVES: (i) To present a scale for measuring patient perception of quality of
care following a visit to a doctor; and (ii) to analyse the responses given by
patients recruited in primary care units in the Montreal region. The scale is
composed of 22 items regrouped into three sub-scales referring to the patient
physician relationship (five items); the technical aspects of care (12 items);
and the outcomes of the visit (five items). Distinctive features of the scale are
that it focuses on patients' opinions about quality rather than on satisfaction,
and that it includes items related to outcomes of the visit. METHODS: A survey
was conducted on 473 patients who visited a physician in 11 primary care units in
the Montreal region. Randomly selected patients received mailed questionnaires 5
7 days following their visit. Various statistical procedures were used to assess
the reliability and the validity of the global scale and the sub-scales, and to
analyse patients' patterns of response. RESULTS: The analysis of the psychometric
properties of the global scale and the three sub-scales provides favourable
evidence concerning their reliability and validity. The results of the factor
analysis, the inter-item correlations and the Cronbach's alpha coefficients all
support the distinction made between the interpersonal processes, the technical
processes and the outcomes, and, at the same time, confirm the complex nature of
the notion of perceived quality. The analysis of patients' responses allows the
identification of items associated with global perception about quality of care.
This global perception results from patients' perception of the physician's
professional and interpersonal skills as well as from the outcomes of care.
CONCLUSION: The scale can be used by physicians or primary health care units and
has a wide range of applications.
PMID- 10673485
TI - Which literature retrieval method is most effective for GPs?
AB - BACKGROUND: Evidence-based medicine requires new skills of physicians, including
literature searching. OBJECTIVE: To determine which literature retrieving method
is most effective for GPs: the printed Index Medicus; Medline through Grateful
Med; or Medline on CD-ROM. METHODS: The design was a randomized comparative
study. In a continuing medical education course, three groups of health care
professionals (87 GPs and 16 other health care professionals) used one of the
literature retrieval methods to retrieve citations on four search topics related
to general practice. For the analysis in pairs, we used the search results of the
75 participants who completed all four assignments. As outcome measures, we used
precision, recall and an overall search quality score; we also had a post-course
questionnaire on personal characteristics, experience with computers, handling
medical literature and satisfaction with course instruction and search results.
RESULTS: The recall and overall search quality scores in the Index Medicus groups
(n = 32) were higher (P = <0.001) than those in the CD-ROM groups (n = 31). In
addition, the search quality scores in the Grateful Med groups (n = 12) were
higher (P < 0.003) than those in the CD-ROM groups. There were no differences in
precision. CONCLUSION: In the period 1994-1997, the printed Index Medicus was the
most effective literature retrieval method for GPs. For inexperienced GPs, there
is a need for training in electronic literature retrieval methods.
PMID- 10673486
TI - A study of factors associated with cost and variation in prescribing among GPs.
AB - BACKGROUND: Inappropriate prescribing has the potential to harm both the
individual and society. Previous research has identified doctor or demographic
characteristics that influence prescribing variation but which were not amenable
to change. OBJECTIVES: To identify modifiable factors associated with GP
prescribing variance and cost. METHOD: Qualitative research methods were used in
semi-structured taped interviews with 17 GPs in Avon, South West NHS Region, UK.
RESULTS: GPs considered themselves cautious and conservative prescribers.
Prescribing decisions often were justified by the prescriber, despite conflicting
clinical or cost arguments. A personally developed drug formulary was used to
reduce dilemmas potentially associated with prescribing uncertainty. Willingness
to reflect upon, and measure, prescribing habits against set professional
standards varied considerably. The absence of monitoring mechanisms of
prescribing decisions, coupled with under utilization of the community
pharmacist, resulted in uncertain prescribing outcomes. Some GPs found it
difficult to keep up to date professionally due to perceived time constraints.
Excessive patient demand was considered to influence their prescribing, but GPs
stated that they were not unduly influenced by the drug representative.
CONCLUSIONS: Prescribing makes a considerable impact on health and budgets and
yet remains a contentious issue. Improved partnerships between patient, doctor
and pharmacist must be established. Better prescribing decision monitoring and
support through policy development and educational intervention is needed to
reduce prescribing uncertainty. Newly established Primary Care Groups may need to
reflect upon the difficulties facing prescribers, particularly when prescribing
within cash-limited budgets, to avoid discord between prescribing behaviour and
local policy development.
PMID- 10673487
TI - Patient adherence to family practitioners' recommendations for breast cancer
screening: a historical cohort study.
AB - BACKGROUND: Breast cancer is the most prevalent malignancy among women in Israel,
and routine screening is recommended for early detection. In 1997, a health
management organization primary care centre in rural Israel established a 1-year
programme wherein family physicians were encouraged to remind their patients to
undergo breast cancer examinations. This study evaluates the impact of the
physicians' intervention on patient compliance. METHODS: Family practitioners
from two practices were requested to discuss the importance of early breast
cancer detection with all eligible patients who visited the clinic for any reason
and to assist them in scheduling an appointment for screening. The files of the
patients who received the recommendation were stamped accordingly. On completion
of the programme, the physicians' files were audited, and the potential
candidates for breast cancer screening were divided into two groups: those who
had received the intervention (n = 251) and those who had not (n = 187); results
were also compared with those of a third group of patients who had gone for an
examination on their own initiative (n = 100) prior to the study (i.e. did not
require intervention). A random sample of half the patients also completed an ad
hoc questionnaire covering sociodemographic variables and the impact of the
doctors' intervention on their behaviour. RESULTS: Patients in the intervention
group showed a significantly greater change in behaviour regarding breast cancer
screening than the controls (32% versus 13%, P = 0.001). This change was
manifested particularly in the group of women aged 50-74 years who received the
recommendation for mammography to be performed (according to the guidelines).
CONCLUSION: Although this is a study in only two practices, the results suggest
that primary care physicians can significantly alter the behaviour of their
patients regarding regular breast examinations. The use of a special reminder can
also help the individual doctor to ensure that each patient has been properly
instructed.
PMID- 10673488
TI - Influence of postal distribution of the Royal College of Radiologists'
guidelines, together with feedback on radiological referral rates, on X-ray
referrals from general practice: a randomized controlled trial.
AB - BACKGROUND: The Royal College of Radiologists (RCR) have produced regularly
updated guidelines on radiological referrals since 1990. A small study in 1992
showed postal distribution of guidelines reduced general practitioners' referrals
over the subsequent 9 weeks. However there have been no randomized trials of the
longer term effects of radiological guidelines and feedback on referral rates on
X-ray requests from primary care. OBJECTIVES: To see if the introduction of
radiological guidelines into general practices together with feedback on referral
rates reduces the number of GP radiological requests over one year; and to
explore GPs'attitudes to the guidelines. METHODS: Sixty-nine practices referring
patients to St George's Healthcare Trust were randomly allocated to intervention
or control groups. In February 1995 a GP version of the RCR guidelines was sent
to each GP in the 33 practices in the intervention group. After 9 months
intervention, practices were sent revised guidelines with individual feedback on
the number of examinations requested in the past 6 months. The total number of
requests per practice was compared for the year before and the year after the
introduction of the guidelines. Control practices were sent the guidelines at the
end of the study. All doctors were sent a questionnaire about the guidelines.
RESULTS: A total of 43 778 radiological requests were made during the two years
1994-1996. In practices receiving the guidelines there was a 20% reduction in
requests for spinal examinations compared with control practices (P < 0.05). This
corresponded to the effect reported by GPs. There was also a 10% difference
between the groups in the total number of requests made, but due to wide
interpractice variation in referral rates this failed to reach statistical
significance. CONCLUSIONS: Introduction of radiological guidelines together with
feedback on referral rates was effective in reducing the number of requests for
spinal examinations over one year. Wider use of GP-orientated guidelines with
regular updating and feedback might save costs and reduce unnecessary irradiation
of patients.
PMID- 10673489
TI - GPs' employment of locum doctors and satisfaction with their service.
AB - BACKGROUND: Locum doctors provide cover during normal working hours for GPs
absent due to holidays, sickness, maternity leave or for educational purposes.
However, there is little information on the extent of the use of locums or of
GPs' perception of their services. OBJECTIVES: To examine the level of use of
locum doctors by GPs, the ease of recruitment and satisfaction with their
services. METHODS: A postal survey of all general practices in one of the six
health regions in England was carried out. Logistic regression analysis was used
to examine the independent effects on locum use of practice size and type of
area, source of recruitment and GPs' satisfaction with their services. RESULTS: A
total of 935 (80.6%) general practices responded. Locum GPs were employed by
81.7% of practices in the previous 12 months. Two-thirds of practices reported
problems obtaining locum cover, especially at short notice and for holiday
periods. One-fifth of practices employing a locum in the previous 12 months were
dissatisfied with the locum. CONCLUSIONS: There are high demands for, but a
considerable shortage of, locum doctors in general practice. Educational and
other initiatives for GPs may contribute to increased demands for locum cover.
Difficulties in recruitment may be reduced by measures to improve the conditions
of employment for doctors working as locums on a longer term basis. New codes of
practice for employing locums may increase satisfaction with locum services.
PMID- 10673490
TI - Condom promotion in women attending inner city general practices for cervical
smears: a randomized controlled trial.
AB - BACKGROUND: Although condom promotion schemes have been widely piloted in UK
general practices, there have been no rigorous evaluations of their
effectiveness. OBJECTIVES: To see if a practice-based sexual health education
intervention increases the number of women having smears who are given condoms
and advice on avoiding STDs. To see if this low cost intervention affects
subsequent condom use. METHOD: We conducted a cluster randomized trial of condom
promotion in 1382 women aged <35 years attending 28 South London general
practices for cervical smear tests. RESULTS: More women in intervention than
control practices reported receiving advice on avoiding sexually transmitted
infections (27% versus 10%) and being given condoms (28% versus 1%, P < 0.05).
However, there was no difference in subsequent condom use, even in the 22% of
women reporting >/=2 sexual partners in the previous year. CONCLUSIONS: To
provide evidence of effectiveness, future interventions may need to be more
intensive or focus on higher risk groups.
PMID- 10673491
TI - A pilot study of cardiovascular risk assessment in Afro-Caribbean patients
attending an inner city general practice.
AB - BACKGROUND: Afro-Caribbean ethnic minorities are at high risk of stroke and the
sequelae of hypertension. OBJECTIVE: To investigate cardiovascular risk factors
and Dundee risk rank in Afro-Caribbeans attending one inner city general practice
and to find which methods of health promotion patients preferred. METHODS: We
assessed cardiovascular risk including systolic and diastolic blood pressure in
98 patients of Afro-Caribbean origin. RESULTS: Fifty per cent of the patients had
at least two risk factors for cardiovascular disease. Focus groups suggested that
the barriers to effective health promotion included lack of risk awareness,
cultural and lifestyle influences, time restrictions and language difficulties.
CONCLUSIONS: The small pilot study highlights both the need for and some of the
problems of GP-based cardiovascular health promotion in Afro-Caribbeans.
PMID- 10673492
TI - Criteria for selecting and using non-steroidal anti-inflammatory drugs in primary
health care.
AB - BACKGROUND: Numerous non-steroidal anti-inflammatory drugs (NSAIDs) are
commercially available in Spain. This makes proper selection and use of these
drugs difficult for GPs. OBJECTIVE: To find out the criteria which GPs use to
choose among the drugs in this group and to evaluate other criteria related to
the clinical management of NSAIDs. METHOD: A survey questionnaire was distributed
among all the GPs of the reformed network in the health area of Tarragona
(Spain). RESULTS: The doctors questioned chose a limited number of NSAIDs. Major
preferences were diclofenac and piroxicam. The main criteria for selection were:
efficacy and safety of the drug; previous and/or current gastrointestinal
pathology of the patient; the difference between acute and chronic use; and the
type of inflammatory process. There were a large number of combinations of routes
of administration. The histamine H2 antagonists were the prophylactic drugs which
were used most for gastropathy. CONCLUSION: Sometimes the main criteria for
choosing between the drugs in this study do not reflect the drugs that are used
in clinical practice. Some of the criteria used by GPs for selecting and using
NSAIDs should be reviewed.
PMID- 10673493
TI - Costing interventions in primary care.
AB - Against a background of increasing demands on limited resources, studies that
relate benefits of health interventions to the resources they consume will be an
important part of any decision-making process in primary care, and an accurate
assessment of costs will be an important part of any economic evaluation.
Although there is no such thing as a gold standard cost estimate, there are a
number of basic costing concepts that underlie any costing study. How costs are
derived and combined will depend on the assumptions that have been made in their
derivation. It is important to be clear what assumptions have been made and why
in order to maintain consistency across comparative studies and prevent
inappropriate conclusions being drawn. This paper outlines some costing concepts
and principles to enable primary care practitioners and researchers to have a
basic understanding of costing exercises and their pitfalls.
PMID- 10673494
TI - The 'doctor' or the 'girl from the University'? Considering the influence of
professional roles on qualitative interviewing.
AB - BACKGROUND: Qualitative research methods are now recognized as valuable tools for
primary care. With the increasing emphasis on evidence-based medicine and
critical appraisal of published work, it is important that qualitative
researchers are transparent about their methods and discuss the impact of the
research process on their data. OBJECTIVES: To consider the impact of the
professional background of researchers on in-depth interviewing in primary care.
METHODS: We compare interactions between the interviewer and respondents in two
qualitative interview studies of heart disease. Both samples consisted of 60
middle-aged men and women from a range of social backgrounds living in the West
of Scotland. One study was conducted by a GP and the other by a sociologist.
RESULTS: Some interview interactions were common to both researchers; for
example, interviews were often regarded by respondents as therapeutic. However,
some interactions seemed to be related to the researcher's professional
background. The GP's perceived higher status led to obscuring of her personal
characteristics. The sociologist was often perceived as a 'young woman' rather
than defined by her professional role. Thus respondents' perceptions of the
interviewer influenced the interview interactions. CONCLUSIONS: Appraising
qualitative research depends on the transparency with which the research process
is described. Awareness of professional background is particularly important for
university departments of primary care (which often include doctors, nurses and
social scientists) and should be considered carefully in designing, carrying out
and disseminating the results of qualitative studies.
PMID- 10673495
TI - Acquiring qualitative skills for primary care research. Review and reflections on
a three-stage workshop. Part 1: using interviews to generate data. Members of
WoReN. Wolds Primary Care Research Network.
AB - This paper reflects on one Primary Care Research Network's (WoReN's) experience
of running a workshop on generating interview data, provided as the first of a
three-part workshop concerned with acquiring qualitative interviewing skills. It
discusses the aims and limitations of the short workshop format in meeting the
needs of practitioners embarking on qualitative research, drawing upon and
reviewing the relevant research methods literature, and makes suggestions with
regard to designing and running research methods workshops within primary care.
PMID- 10673496
TI - Acquiring qualitative skills for primary care research. Review and reflections on
a three-stage workshop. Part 2: analysing interview data. Members of WoReN.
Primary Care Research Network.
AB - This paper reflects on one Primary Care Research Network's (WoReN's) experience
of running a workshop on analysing qualitative interview data, provided as the
second of a three-part workshop concerned with acquiring qualitative interviewing
skills. It discusses the aims and limitations of the short workshop format in
meeting the needs of practitioners embarking on the process of analysing
qualitative data, drawing upon and reviewing the relevant research methods
literature. Particular attention is paid to the role of qualitative data analysis
computer packages and the debate on 'grounded theory'. We conclude by making
suggestions with regard to designing and running data analysis workshops within
primary care.
PMID- 10673497
TI - Selections from current literature. Psychoneuroimmunology: validation of the
biopsychosocial model.
PMID- 10673498
TI - Light: an indicator of time and place.
PMID- 10673499
TI - Gene dose-dependent control of hematopoiesis and hematologic tumor suppression by
CBP.
AB - Mice with monoallelic inactivation of the CBP gene develop highly penetrant,
multilineage defects in hematopoietic differentiation and, with advancing age, an
increased incidence of hematologic malignancies. The latter are characterized, at
least in some cases, by loss of heterozygosity (LOH) at the CBP locus. No such
pathology was observed in wild-type or p300 heterozygous null mice of the same
age and genetic background. Thus, a full complement of CBP, but not p300, is
required for normal hematopoietic differentiation. These results also provide the
first experimental evidence for the hypothesis that CBP has tumor-suppressing
activity.
PMID- 10673500
TI - Chk2/hCds1 functions as a DNA damage checkpoint in G(1) by stabilizing p53.
AB - Chk2/hcds1, the human homolog of the Saccharomyces cerevisiae RAD53/SPK1 and
Schizosaccharomyces pombe cds1 DNA damage checkpoint genes, encodes a protein
kinase that is post-translationally modified after DNA damage. Like its yeast
homologs, the Chk2/hCds1 protein phosphorylates Cdc25C in vitro, suggesting that
it arrests cells in G(2) in response to DNA damage. We expressed Chk2/hCds1 in
human cells and analyzed their cell cycle profile. Wild-type, but not
catalytically inactive, Chk2/hCds1 led to G(1) arrest after DNA damage. The
arrest was inhibited by cotransfection of a dominant-negative p53 mutant,
indicating that Chk2/hCds1 acted upstream of p53. In vitro, Chk2/hCds1
phosphorylated p53 on Ser-20 and dissociated preformed complexes of p53 with
Mdm2, a protein that targets p53 for degradation. In vivo, ectopic expression of
wild-type Chk2/hCds1 led to increased p53 stabilization after DNA damage, whereas
expression of a dominant-negative Chk2/hCds1 mutant abrogated both
phosphorylation of p53 on Ser-20 and p53 stabilization. Thus, in response to DNA
damage, Chk2/hCds1 stabilizes the p53 tumor suppressor protein leading to cell
cycle arrest in G(1).
PMID- 10673501
TI - The human homologs of checkpoint kinases Chk1 and Cds1 (Chk2) phosphorylate p53
at multiple DNA damage-inducible sites.
AB - Upon DNA damage, the amino terminus of p53 is phosphorylated at a number of
serine residues including S20, a site that is particularly important in
regulating stability and function of the protein. Because no known kinase has
been identified that can modify this site, HeLa nuclear extracts were
fractionated and S20 phosphorylation was followed. We discovered that a S20
kinase activity copurifies with the human homolog of the Schizosaccharomyces
pombe checkpoint kinase, Chk1 (hCHK1). We confirmed that recombinant hCHK1, but
not a kinase-defective version of hCHK1, can phosphorylate p53 in vitro at S20.
Additional inducible amino- and carboxy-terminal sites in p53 are also
phosphorylated by hCHK1, indicating that this is an unusually versatile protein
kinase. It is interesting that hCHK1 strongly prefers tetrameric to monomeric p53
in vitro, consistent with our observation that phosphorylation of amino-terminal
sites in vivo requires that p53 be oligomeric. Regulation of the levels and
activity of hCHK1 in transfected cells is directly correlated with the levels of
p53; expression of either a kinase-defective hCHK1 or antisense hCHK1 leads to
reduced levels of cotransfected p53, whereas overexpression of wild-type hCHK1 or
the kinase domain of hCHK1 results in increased levels of expressed p53 protein.
The human homolog of the second S. pombe checkpoint kinase, Cds1 (CHK2/hCds1),
phosphorylates tetrameric p53 but not monomeric p53 in vitro at sites similar to
those phosphorylated by hCHK1 kinase, suggesting that both checkpoint kinases can
play roles in regulating p53 after DNA damage.
PMID- 10673502
TI - c-Kit triggers dual phosphorylations, which couple activation and degradation of
the essential melanocyte factor Mi.
AB - Microphthalmia (Mi) is a bHLHZip transcription factor that is essential for
melanocyte development and postnatal function. It is thought to regulate both
differentiated features of melanocytes such as pigmentation as well as
proliferation/survival, based on phenotypes of mutant mouse alleles. Mi activity
is controlled by at least two signaling pathways. Melanocyte-stimulating hormone
(MSH) promotes transcription of the Mi gene through cAMP elevation, resulting in
sustained Mi up-regulation over many hours. c-Kit signaling up-regulates Mi
function through MAP kinase phosphorylation of Mi, thereby recruiting the p300
transcriptional coactivator. The current study reveals that c-Kit signaling
triggers two phosphorylation events on Mi, which up-regulate transactivation
potential yet simultaneously target Mi for ubiquitin-dependent proteolysis. The
specific activation/degradation signals derive from MAPK/ERK targeting of serine
73, whereas serine 409 serves as a substrate for p90 Rsk-1. An unphosphorylatable
double mutant at these two residues is at once profoundly stable and
transcriptionally inert. These c-Kit-induced phosphorylations couple
transactivation to proteasome-mediated degradation. c-Kit signaling thus triggers
short-lived Mi activation and net Mi degradation, in contrast to the profoundly
increased Mi expression after MSH signaling, potentially explaining the
functional diversity of this transcription factor in regulating proliferation,
survival, and differentiation in melanocytes.
PMID- 10673503
TI - Transient depletion of xDnmt1 leads to premature gene activation in Xenopus
embryos.
AB - In Xenopus laevis zygotic transcription begins at the midblastula transition
(MBT). Prior to this the genome is organized into chromatin that facilitates
rapid cycles of DNA replication but not transcription. Here we demonstrate that
DNA methylation contributes to the overall transcriptional silencing before MBT.
Transient depletion of the maternal DNA methyltransferase (xDnmt1) by anti sense
RNA during cleavage stages is associated with a decrease in the genomic 5-methyl
cytosine content and leads to the activation of zygotic transcription
approximately two cell cycles earlier than normal. Hypomethylation allows the
early expression of mesodermal marker genes such as Xbra, Cerberus, and Otx2,
which are subsequently down-regulated during gastrulation of the xDnmt1-depleted
embryos. The temporal switch in gene expression may account for the appearance of
body plan defects that we observe. Loss of xDnmt1 can be rescued by the
coinjection of mouse or human Dnmt1 protein. These results demonstrate that DNA
methylation has a role in the regulation of immediately early genes in Xenopus at
MBT.
PMID- 10673504
TI - Absence of Wee1 ensures the meiotic cell cycle in Xenopus oocytes.
AB - Meiotic cells undergo two successive divisions without an intervening S phase.
However, the mechanism of S-phase omission between the two meiotic divisions is
largely unknown. Here we show that Wee1, a universal mitotic inhibitor, is absent
in immature (but not mature) Xenopus oocytes, being down-regulated specifically
during oogenesis; this down-regulation is most likely due to a translational
repression. Even the modest ectopic expression of Wee1 in immature (meiosis I)
oocytes can induce interphase nucleus reformation and DNA replication just after
meiosis I. Thus, the presence of Wee1 during meiosis I converts the meiotic cell
cycle into a mitotic-like cell cycle having S phase. In contrast, Myt1, a Wee1
related kinase, is present and directly involved in G(2) arrest of immature
oocytes, but its ectopic expression has little effect on the meiotic cell cycle.
These results strongly indicate that the absence of Wee1 in meiosis I ensures the
meiotic cell cycle in Xenopus oocytes. Based on these results and the data
published previously in other organisms, we suggest that absence of Wee1 may be a
well-conserved mechanism for omitting interphase or S phase between the two
meiotic divisions.
PMID- 10673505
TI - Activation mutants in yeast RNA polymerase II subunit RPB3 provide evidence for a
structurally conserved surface required for activation in eukaryotes and
bacteria.
AB - We have identified a mutant in RPB3, the third-largest subunit of yeast RNA
polymerase II, that is defective in activator-dependent transcription, but not
defective in activator-independent, basal transcription. The mutant contains two
amino-acid substitutions, C92R and A159G, that are both required for pronounced
defects in activator-dependent transcription. Synthetic enhancement of phenotypes
of C92R and A159G, and of several other pairs of substitutions, is consistent
with a functional relationship between residues 92-95 and 159-161. Homology
modeling of RPB3 on the basis of the crystallographic structure of alphaNTD
indicates that residues 92-95 and 159-162 are likely to be adjacent within the
structure of RPB3. In addition, homology modeling indicates that the location of
residues 159-162 within RPB3 corresponds to the location of an activation target
within alphaNTD (the target of activating region 2 of catabolite activator
protein, an activation target involved in a protein-protein interaction that
facilitates isomerization of the RNA polymerase promoter closed complex to the
RNA polymerase promoter open complex). The apparent finding of a conserved
surface required for activation in eukaryotes and bacteria raises the possibility
of conserved mechanisms of activation in eukaryotes and bacteria.
PMID- 10673506
TI - Nucleotide excision repair of DNA with recombinant human proteins: definition of
the minimal set of factors, active forms of TFIIH, and modulation by CAK.
AB - During human nucleotide excision repair, damage is recognized, two incisions are
made flanking a DNA lesion, and residues are replaced by repair synthesis. A set
of proteins required for repair of most lesions is RPA, XPA, TFIIH, XPC-hHR23B,
XPG, and ERCC1-XPF, but additional components have not been excluded. The most
complex and difficult to analyze factor is TFIIH, which has a 6-subunit core
(XPB, XPD, p44, p34, p52, p62) and a 3-subunit kinase (CAK). TFIIH has roles both
in basal transcription initiation and in DNA repair, and several inherited human
disorders are associated with mutations in TFIIH subunits. To identify the forms
of TFIIH that can function in repair, recombinant XPA, RPA, XPC-hHR23B, XPG, and
ERCC1-XPF were combined with TFIIH fractions purified from HeLa cells. Repair
activity coeluted with the peak of TFIIH and with transcription activity. TFIIH
from cells with XPB or XPD mutations was defective in supporting repair, whereas
TFIIH from spinal muscular atrophy cells with a deletion of one p44 gene was
active. Recombinant TFIIH also functioned in repair, both a 6- and a 9-subunit
form containing CAK. The CAK kinase inhibitor H-8 improved repair efficiency,
indicating that CAK can negatively regulate NER by phosphorylation. The 15
recombinant polypeptides define the minimal set of proteins required for dual
incision of DNA containing a cisplatin adduct. Complete repair was achieved by
including highly purified human DNA polymerase delta or epsilon, PCNA, RFC, and
DNA ligase I in reaction mixtures, reconstituting adduct repair for the first
time with recombinant incision factors and human replication proteins.
PMID- 10673507
TI - RecA protein-dependent R-loop formation in vitro.
AB - The RecA protein of Escherichia coli, which has crucial roles in homologous
recombination, DNA damage repair, induction of the SOS response, and SOS
mutagenesis, was found to catalyze assimilation of complementary RNA into a
homologous region of a DNA duplex (R-loop). The reaction strictly requires a
region of mismatch in the duplex, which may serve as a nucleation site for RecA
protein polymerization. The optimum conditions for the assimilation reaction
resemble those for the previously studied RecA protein-catalyzed homologous
pairing and strand exchange reaction between two DNA molecules. Our finding lends
strong support to the proposal that RecA protein-catalyzed assimilation of a
transcript into duplex DNA results in formation of an R-loop at certain regions
of the chromosome and that, when stabilized, the R-loop can serve as an origin of
chromosome replication.
PMID- 10673508
TI - Phosphorylation represses Ets-1 DNA binding by reinforcing autoinhibition.
AB - Phosphorylation of transcription factors is a key link between cell signaling and
the control of gene expression. Here we report that phosphorylation regulates DNA
binding of the Ets-1 transcription factor by reinforcing an autoinhibitory
mechanism. Quantitative DNA-binding assays show that calcium-dependent
phosphorylation inhibits Ets-1 DNA binding 50-fold. The four serines that mediate
this inhibitory effect are distant from the DNA-binding domain but near
structural elements required for autoinhibition. Mutational analyses demonstrate
that an intact inhibitory module is required for phosphorylation-dependent
regulation. Partial proteolysis studies indicate that phosphorylation stabilizes
an inhibitory conformation. These findings provide a structural mechanism for
phosphorylation-dependent inhibition of Ets-1 DNA binding and demonstrate a new
function for inhibitory modules as structural mediators of negative signaling
events.
PMID- 10673510
TI - Managed care and oncology: the quality debate.
PMID- 10673509
TI - Repression by suppressor of hairless and activation by Notch are required to
define a single row of single-minded expressing cells in the Drosophila embryo.
AB - Notch signal transduction appears to involve the ligand-induced intracellular
processing of Notch, and the formation of a processed Notch-Suppressor of
Hairless complex that binds DNA and activates the transcription of Notch target
genes. This suggests that loss of either Notch or Su(H) activities should lead to
similar cell fate changes. However, previous data indicate that, in the
Drosophila blastoderm embryo, mesectoderm specification requires Notch but not
Su(H) activity. The determination of the mesectodermal fate is specified by
Single-minded (Sim), a transcription factor expressed in a single row of cells
abutting the mesoderm. The molecular mechanisms by which the dorsoventral
gradient of nuclear Dorsal establishes the single-cell wide territory of sim
expression are not fully understood. We have found that Notch activity is
required for sim expression in cellularizing embryos. In contrast, at this stage,
Su(H) has a dual function. Su(H) activity was required to up-regulate sim
expression in the mesectoderm, and to prevent the ectopic expression of sim
dorsally in the neuroectoderm. We have shown that repression of sim transcription
by Su(H) is direct and independent of Notch activity. Conversely, activation of
sim transcription by Notch requires the Su(H)-binding sites. Thus, Notch
signalling appears to relieve the repression exerted by Su(H) and to up-regulate
sim transcription in the mesectoderm. We propose a model in which repression by
Su(H) and derepression by Notch are essential to allow for the definition of a
single row of mesectodermal cells in the blastoderm embryo.
PMID- 10673511
TI - Phase II trial of the antiangiogenic agent thalidomide in patients with recurrent
high-grade gliomas.
AB - PURPOSE: Little progress has been made in the treatment of adult high-grade
gliomas over the last two decades, thus necessitating a search for novel
therapeutic strategies. Malignant gliomas are vascular or angiogenic tumors,
which leads to the supposition that angiogenesis inhibition may represent a
potentially promising strategy in the treatment of these tumors. We present the
results of a phase II trial of thalidomide, a putative inhibitor of angiogenesis,
in the treatment of adults with previously irradiated, recurrent high-grade
gliomas. PATIENTS AND METHODS: Patients with a histologic diagnosis of anaplastic
mixed glioma, anaplastic astrocytoma, or glioblastoma multiforme who had
radiographic demonstration of tumor progression after standard external-beam
radiotherapy with or without chemotherapy were eligible. Patients were initially
treated with thalidomide 800 mg/d with increases in dose by 200 mg/d every 2
weeks until a final daily dose of 1,200 mg was achieved. Patients were evaluated
every 8 weeks for response by both clinical and radiographic criteria. RESULTS: A
total of 39 patients were accrued, with 36 patients being assessable for both
toxicity and response. Thalidomide was well tolerated, with constipation and
sedation being the major toxicities. One patient developed a grade 2 peripheral
neuropathy after treatment with thalidomide for nearly a year. There were two
objective radiographic partial responses (6%), two minor responses (6%), and 12
patients with stable disease (33%). Eight patients were alive more than 1 year
after starting thalidomide, although almost all with tumor progression. Changes
in serum levels of basic fibroblastic growth factor (bFGF) were correlated with
time to tumor progression and overall survival. CONCLUSION: Thalidomide is a
generally well-tolerated drug that may have antitumor activity in a minority of
patients with recurrent high-grade gliomas. Future studies will better define the
usefulness of thalidomide in newly diagnosed patients with malignant gliomas and
in combination with radiotherapy and chemotherapy. Additionally, studies will be
needed to confirm the potential utility of changes in serum bFGF as a marker of
antiangiogenic activity and/or glioma growth.
PMID- 10673512
TI - Results of a randomized study of IM862 nasal solution in the treatment of AIDS
related Kaposi's sarcoma.
AB - PURPOSE: Although advances have been made in the treatment of AIDS-related
Kaposi's sarcoma (AIDS-KS) with systemic chemotherapy, less toxic therapies are
needed. IM862 is a naturally occurring peptide with antiangiogenic properties and
was thus studied in patients with AIDS-KS. PATIENTS AND METHODS: IM862 was given
as intranasal drops at a dose of 5 mg. Patients were randomized to two dosing
schedules given in repeated cycles until disease progression or unacceptable
toxicity: 5 days of therapy followed by 5 days off (n = 18) and every other day
dosing (n = 26). RESULTS: Forty-two male patients and two female patients with a
median age of 38 years (range, 22 to 53 years) were accrued. Twenty-one patients
(47%) had more than 50 mucocutaneous lesions, 14 (32%) had lymphedema, and none
had visceral involvement. Thirty-three patients (75%) had received prior systemic
chemotherapy. Twenty-four patients (55%) had CD4(+) lymphocyte count =
200/mm(3). All but five patients were being treated with concurrent protease
inhibitor(s), for a median of 10 months (range, 0 to 24 months). Major responses
were documented in 36%, with five complete and 11 partial remissions, occurring
after a median of 6 weeks (range, 3 to 26 weeks) and lasting a median of 33+
weeks (range, 12+ to 95+ weeks). Twenty-one patients had stable disease for
periods of 7 to 72+ weeks. Adverse effects to IM862 were limited to mild and
transient headache, fatigue, tingling, and nausea. No hematologic adverse effects
attributed to treatment were reported. CONCLUSION: IM862 given as intranasal
drops is well tolerated and has antitumor activity in patients with AIDS-KS. A
randomized double-blinded study to define the activity of IM862 in patients with
AIDS-KS is in progress.
PMID- 10673513
TI - Paclitaxel versus doxorubicin as first-line single-agent chemotherapy for
metastatic breast cancer: a European Organization for Research and Treatment of
Cancer Randomized Study with cross-over.
AB - PURPOSE: To compare the efficacy of paclitaxel versus doxorubicin given as single
agents in first-line therapy of advanced breast cancer (primary end point,
progression-free survival ?PFS) and to explore the degree of cross-resistance
between the two agents. PATIENTS AND METHODS: Three hundred thirty-one patients
were randomized to receive either paclitaxel 200 mg/m(2), 3-hour infusion every 3
weeks, or doxorubicin 75 mg/m(2), intravenous bolus every 3 weeks. Seven courses
were planned unless progression or unacceptable toxicity occurred before the
seven courses were finished. Patients who progressed within the seven courses
underwent early cross-over to the alternative drug, while a delayed cross-over
was optional for the remainder of patients at the time of disease progression.
RESULTS: Objective response in first-line therapy was significantly better (P
=.003) for doxorubicin (response rate ?RR, 41%) than for paclitaxel (RR, 25%),
with doxorubicin achieving a longer median PFS (7.5 months for doxorubicin v 3.9
months for paclitaxel, P <.001). In second-line therapy, cross-over to
doxorubicin (91 patients) and to paclitaxel (77 patients) gave response rates of
30% and 16%, respectively. The median survival durations of 18.3 months for
doxorubicin and 15.6 months for paclitaxel were not significantly different (P
=.38). The doxorubicin arm had greater toxicity, but this was counterbalanced by
better symptom control. CONCLUSION: At the dosages and schedules used in the
present study, doxorubicin achieves better disease and symptom control than
paclitaxel in first-line treatment. Doxorubicin and paclitaxel are not totally
cross-resistant, which supports further investigation of these drugs in
combination or in sequence, both in advanced disease and in the adjuvant setting.
PMID- 10673514
TI - Value of estrogenic recruitment before chemotherapy: first randomized trial in
primary breast cancer.
AB - PURPOSE: Several preclinical studies showed that short-term pretreatment of
breast cancer cells with estrogens can increase the antitumor efficacy of
different cytotoxic drugs. Some early clinical studies in patients with advanced
breast cancer did seem to support these findings. Therefore, the efficacy of
estrogenic recruitment followed by chemotherapy was compared with that of
chemotherapy alone in a randomized phase III study in women with lymph node
positive primary breast cancer. PATIENTS AND METHODS: Three hundred twenty-eight
patients with stage II/IIIA breast cancer who were younger than 66 years of age
were randomly allocated to chemotherapy with fluorouracil, doxorubicin, and
cyclophosphamide (FAC) or FAC plus pretreatment with ethinyl estradiol (EE(2)).
FAC (500, 50, and 500 mg/m(2), respectively) was administered intravenously once
every 4 weeks for four cycles. EE(2) (0.5 mg) was administered orally, both 24
hours and immediately preceding FAC chemotherapy. RESULTS: Patient and tumor
characteristics and chemotherapy dosages were comparable in both treatment
groups. Of 318 assessable patients, with a median follow-up of 6.8 years, 177
patients had a relapse and 127 died. No significant differences were observed
between the two treatment groups with respect to relapse-free, local recurrence
free, and overall survival according to univariate and multivariate analyses
adjusted for age, menopausal status, tumor size, grade, number of positive nodes,
and steroid-receptor status. The power for the detection of an increase of 50% in
the median relapse-free survival was 80%. CONCLUSION: Estrogenic recruitment of
breast cancer cells before FAC chemotherapy did not influence the efficacy of
adjuvant chemotherapy in stage II/IIIA breast cancer patients after a follow-up
of 6.8 years.
PMID- 10673515
TI - Fatigue in breast cancer survivors: occurrence, correlates, and impact on quality
of life.
AB - PURPOSE: To describe the occurrence of fatigue in a large sample of breast cancer
survivors relative to general population norms and to identify demographic,
medical, and psychosocial characteristics of fatigued survivors. PATIENTS AND
METHODS: Breast cancer survivors in two large metropolitan areas completed
standardized questionnaires as part of a survey study, including the RAND 36-item
Health Survey, Center for Epidemiological Studies-Depression Scale, Breast Cancer
Prevention Trial Symptom Checklist, Medical Outcomes Study Sleep Scale, and
demographic and treatment-related measures. RESULTS: On average, the level of
fatigue reported by the breast cancer survivors surveyed (N = 1,957) was
comparable to that of age-matched women in the general population, although the
breast cancer survivors were somewhat more fatigued than a more demographically
similar reference group. Approximately one third of the breast cancer survivors
assessed reported more severe fatigue, which was associated with significantly
higher levels of depression, pain, and sleep disturbance. In addition, fatigued
women were more bothered by menopausal symptoms and were somewhat more likely to
have received chemotherapy (with or without radiation therapy) than nonfatigued
women. In multivariate analyses, depression and pain emerged as the strongest
predictors of fatigue. CONCLUSION: Although the majority of breast cancer
survivors in this large and diverse sample did not experience heightened levels
of fatigue relative to women in the general population, there was a subgroup of
survivors who did report more severe and persistent fatigue. We identified
characteristics of these women that may be helpful in elucidating the mechanisms
underlying fatigue in this population, as well as directing intervention efforts.
PMID- 10673516
TI - High-dose sequential chemotherapy with recombinant granulocyte colony-stimulating
factor and repeated stem-cell support for inflammatory breast cancer patients:
does impact on quality of life jeopardize feasibility and acceptability of
treatment?
AB - PURPOSE: This study was designed to investigate the quality of life (QOL) of
patients enrolled onto the High-Dose Chemotherapy for Breast Cancer Study Group
trial (PEGASE 02), a French pilot multicenter trial of the treatment of
inflammatory breast cancer (IBC) aimed at evaluating (1) toxicity and feasibility
of sequential high-dose chemotherapy (HDC) with recombinant human granulocyte
colony-stimulating factor (filgrastim) and stem-cell support and (2) response to
HDC in terms of pathologic response and survival. PATIENTS AND METHODS: QOL
measures were performed at inclusion and four times subsequently up to 1 year
using an ad hoc side-effect questionnaire (19 physical symptoms) and the European
Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire
(EORTC QLQ-C30). RESULTS: Of the 95 patients entered, the overall QOL
questionnaire completion compliance was 75.6%. During cycle 3 of HDC, the number
of symptoms was high (mean +/- SD QOL score, 10 +/- 3), with fatigue, hair loss,
appetite loss, nausea, change in taste, vomiting, fever, and weight loss reported
by more than 60% of patients. Toxicity and distress associated with HDC were
reflected in the decline of four EORTC QLQ-C30 scores: global QOL (P =.001), and
physical, role, and social functioning (P <.001 for all statistics). However, QOL
deterioration disappeared after treatment completion, except for physical
functioning (P =.025). One year after inclusion, most QOL scores returned to
baseline, and both emotional functioning and global QOL scores were even higher
than baseline (P =.030 and P =.009, respectively). CONCLUSION: If it is confirmed
that improvements in pathologic response rates with HDC effectively translate
into increased probabilities of survival for IBC patients, adoption of such
treatment as PEGASE 02 will not involve crucial choices between length of life
and QOL and should not be delayed for QOL arguments.
PMID- 10673517
TI - Management of breast cancer after Hodgkin's disease.
AB - PURPOSE: To evaluate the incidence, detection, pathology, management, and
prognosis of breast cancer occurring after Hodgkin's disease. PATIENTS AND
METHODS: Seventy-one cases of breast cancer in 65 survivors of Hodgkin's disease
were analyzed. RESULTS: The median age at diagnosis was 24.6 years for Hodgkin's
disease and 42.6 years for breast cancer. The relative risk for invasive breast
cancer after Hodgkin's disease was 4.7 (95% confidence interval, 3.4 to 6. 0)
compared with an age-matched cohort. Cancers were detected by self-examination
(63%), mammography (30%), and physician exam (7%). The histologic distribution
paralleled that reported in the general population (85% ductal histology) as did
other features (27% positive axillary lymph nodes, 63% positive estrogen
receptors, and 25% family history). Although 87% of tumors were less than 4 cm,
95% were managed with mastectomy because of prior radiation. Two women underwent
lumpectomy with breast irradiation. One of these patients developed tissue
necrosis in the region of overlap with the prior mantle field. The incidence of
bilateral breast cancer was 10%. Adjuvant systemic therapy was well tolerated;
doxorubicin was used infrequently. Ten-year disease-specific survival was as
follows: in-situ disease, 100%; stage I, 88%; stage II, 55%; stage III, 60%; and
stage IV, zero. CONCLUSION: The risk of breast cancer is increased after
Hodgkin's disease. Screening has been successful in detecting early-stage
cancers. Pathologic features and prognosis are similar to that reported in the
general population. Repeat irradiation of the breast can lead to tissue necrosis,
and thus, mastectomy remains the standard of care in most cases.
PMID- 10673518
TI - Randomized trial of fludarabine versus fludarabine and idarubicin as frontline
treatment in patients with indolent or mantle-cell lymphoma.
AB - PURPOSE: A first comparative trial of fludarabine (FLU) alone versus FLU plus
idarubicin (FLU-ID) for indolent or mantle-cell lymphomas. PATIENTS AND METHODS:
From September 1995 to July 1998, 199 patients aged 25 to 65 years (median, 54
years) with newly diagnosed stages II to IV indolent or mantle-cell lymphomas
(standard risk according to the International Prognostic Index) were enrolled
onto a multicenter, 1:1 randomized study. Of the 199 patients who were able to be
assessed, 101 were assigned to the FLU group (six monthly cycles of FLU 25
mg/m(2)/d on days 1 through 5) and 98 to the FLU-ID group (six monthly cycles of
FLU 25 mg/m(2)/d on days 1 through 3 and idarubicin 12 mg/m(2) on day 1).
RESULTS: In the FLU group, complete response (CR) and partial response rates were
47% and 37%, respectively, whereas in the FLU-ID group, they were 39% and 42%,
respectively. In-depth analysis of the CR rate with respect to histologic type
showed that FLU seemed to be superior to FLU-ID in treating follicular lymphomas
(60% v 40%, respectively), whereas FLU-ID seemed to be more effective than FLU in
treating nonfollicular lymphomas (small lymphocytic, 43% v 29%, respectively;
immunocytoma, 38% v 23%, respectively; P = not significant), excluding the mantle
cell subset (in which there was no difference between the two groups). No
striking differences were observed between the two protocols in terms of overall
response or toxicity, which was generally mild. However, with a median follow-up
of 19 months, only 29 patients (62%) who received FLU alone have maintained their
initial CR, compared with 32 (84%) of those who received FLU-ID therapy (P
=.021). CONCLUSION: Although the FLU-ID regimen may not significantly improve the
induction of CR in most indolent-lymphoma patients, our preliminary data do
suggest that, with respect to FLU alone, it may be capable of conferring a longer
lasting CR and that it might be superior in terms of CR rate in small lymphocytic
and immunocytoma subtypes.
PMID- 10673519
TI - Granulocyte colony-stimulating factor after intensive consolidation chemotherapy
in acute myeloid leukemia: results of a randomized trial of the Groupe Ouest-Est
Leucemies Aigues Myeloblastiques.
AB - PURPOSE: Ten years after the first clinical studies, the clinical impact of
myeloid growth factors in acute myeloid leukemia is still unclear. One of the
objectives of the Groupe Ouest-Est Leucemies Aigues Myeloblastiques (GOELAM) 2
trial was to evaluate the benefit of granulocyte colony-stimulating factor (GCSF)
given only after the two courses of intensive consolidation chemotherapy (ICC)
used to maintain complete remission (CR). PATIENTS AND METHODS: One hundred
ninety-four patients who were in CR after induction treatment were randomly
assigned to receive G-CSF (100 patients) or no G-CSF (94 patients) after two
courses of ICC (ICC 1, high-dose cytarabine plus mitoxantrone; ICC 2, amsacrine
plus etoposide). G-CSF (filgrastim) was administered from the day after
chemotherapy until granulocyte recovery at a daily dose of 5 microg/kg. RESULTS:
In the G-CSF group, the median duration of neutropenia (< 0.5 x 10(9)/L) was
dramatically reduced, both after ICC 1 (12 v 19 days, P <.001) and after ICC 2
(20 v 28 days, P <.001). The median duration of hospitalization was also
significantly shorter in the G-CSF group (24 v 27 days after ICC 1, P <.001; 29 v
34 days after ICC 2, P <. 001). The median duration of intravenous antibiotics
was significantly reduced after ICC 1 and ICC 2, and the median duration of
antifungal therapy was significantly reduced after ICC 1. However, the incidence
of microbiologically documented infections, the toxic death rate, the 2-year
disease-free survival, and the 2-year overall survival were not affected by G-CSF
administration. Moreover, the median interval between ICC1 and ICC2 was reduced
by only 2 days, and the number of patients undergoing ICC2 was not increased in
the G-CSF arm. CONCLUSION: G-CSF should be administered routinely after ICC to
reduce the duration of neutropenia and hospitalization. However, G-CSF did not
seem to significantly increase the feasibility of this two-course program or
modify overall outcome.
PMID- 10673520
TI - Evaluation of minimal residual disease using reverse-transcription polymerase
chain reaction in t(8;21) acute myeloid leukemia: a multicenter study of 51
patients.
AB - PURPOSE: Most studies using various reverse-transcription polymerase chain
reaction (RT-PCR) techniques reported that the detection of the AML1-ETO fusion
transcript was a common finding in long-term complete remission (CR) in acute
myeloid leukemia (AML) with t(8;21) translocation. However, larger prospective
studies with interlaboratory quality control may be important to investigate more
precisely the clinical usefulness of studying minimal residual disease with RT
PCR in t(8;21) AML. PATIENTS AND METHODS: We collected 223 marrow samples from 51
patients with t(8;21) AML diagnosed in five centers and tested all samples by two
different RT-PCR techniques (a nested technique and a one-step technique, with a
sensitivity of 10(-6) and 10(-5), respectively) in two different laboratories.
RESULTS: Samples from 14 patients in long persistent CR (median follow-up
duration, 112 months) were taken at least twice, and all were PCR-negative by
both techniques. Samples were prospectively taken from 37 patients after
achievement of first CR and/or second CR, before intensive consolidation
treatment, and every 3 to 6 months after completion of therapy. Patients who
converted to PCR negativity with the one-step technique (60%) or both techniques
(48%) after CR achievement had a longer CR duration than those with persistently
positive PCR results (two-sided log-rank test, P =.0001). Patients who became PCR
negative with the one-step technique before intensive consolidation (23%) had a
lower relapse rate (11% v 72%) and a longer CR duration than those who remained
persistently PCR-positive at that point (two-sided log-rank test, P =.0015).
CONCLUSION: Patients with AML with t(8;21) in long-term remission were all PCR
negative. In prospectively studied patients, a good correlation was found between
negative PCR results and absence of relapse. Early negative results with the one
step RT-PCR technique, before consolidation treatment, seemed to carry an
especially good prognosis, suggesting that RT-PCR analysis could help in choosing
the type of consolidation therapy in patients with t(8;21) AML.
PMID- 10673521
TI - Enteropathy-type intestinal T-cell lymphoma: clinical features and treatment of
31 patients in a single center.
AB - PURPOSE: We report the clinical features and treatment of 31 patients with a
diagnosis of enteropathy-type intestinal T-cell lymphoma treated at the Wessex
Regional Medical Oncology Unit in Southampton between 1979 and 1996 (23 men,
eight women). PATIENTS AND METHODS: Patients were identified from our lymphoma
database. Details of history, physical examination, staging investigations,
treatment, and outcome were taken from patient records. RESULTS: Twelve patients
(35%) had a documented clinical history of adult-onset celiac disease, and a
further three had histologic features consistent with celiac disease in resected
areas of the small bowel not infiltrated with lymphoma. After diagnosis, 24 (77%)
of the 31 patients were treated with chemotherapy; the remaining seven had
surgical treatment alone. More than half were unable to complete their planned
chemotherapy courses, often because of poor nutritional status; 12 patients
required enteral or parenteral feeding. A response to initial chemotherapy was
observed in 14 patients (complete response, n = 10; partial response, n = 4).
Observed complications of treatment were gastrointestinal bleeding, small-bowel
perforation, and the development of enterocolic fistulae. Relapses occurred 1 to
60 months from diagnosis in 79% of those who responded to initial therapy. Of the
total 31 patients, 26 (84%) have died, all from progressive disease or from
complications of the disease and/or its treatment. The actuarial 1- and 5-year
survival rates are 38.7% and 19.7%, respectively, with 1- and 5-year failure-free
survival rates of 19.4% and 3.2%, respectively. CONCLUSION: The prognosis for
these patients is poor. This, in part, reflects late diagnosis and poor
performance status at the time of presentation. The role of salvage treatments
and high-dose chemotherapy at relapse is not clear. However, it is encouraging
that there are five long-term survivors in our patient population.
PMID- 10673522
TI - Predictive role of interphase cytogenetics for survival of patients with multiple
myeloma.
AB - PURPOSE: Recent metaphase cytogenetic studies suggested that specific chromosomal
abnormalities are of prognostic significance in patients with multiple myeloma
(MM). Because the true incidence of chromosomal abnormalities in MM is much
higher than that detected by metaphase analysis, we used interphase fluorescence
in situ hybridization (FISH) to determine the prognostic value of specific
chromosomal aberrations. PATIENTS AND METHODS: Bone marrow plasma cells from 89
previously untreated patients with MM were studied consecutively by FISH to
detect the deletions of 13q14, 17p13, and 11q and the presence of
t(11;14)(q13;q32). FISH results were analyzed in the context of clinical
parameters (response to treatment and survival after conventional-dose
chemotherapy), and a multivariate analysis of prognostic factors was performed.
RESULTS: By FISH, the deletion of 13q14 occurred in 40 patients (44.9%), deletion
of 17p13 in 22 (24.7%), and 11q abnormalities in 14 (15.7%; seven with t(11;14)).
Deletions of 13q14 and 17p13 were associated with poor response to induction
treatment (46.9% v 77.3% in those without deletions, P =.006 and 40.0% v 73.2%, P
=.008, respectively) and short median overall survival (OS) time (24.2 v 88.1
months, P =. 008 and 16.2 v 51.3 months, P =.008, respectively). Short median OS
time was also observed for patients with 11q abnormalities (13.1 v 41.6 months, P
=.02). According to the number of unfavorable cytogenetic features (deletion of
13q14, deletion of 17p13, and aberrations of 11q) that were present in each
patient (0 v 1 v 2 or 3), patients with significantly different OS times could be
discriminated from one another (102.4 v 29.6 v 13.9 months, P <.001,
respectively). CONCLUSION: For patients with MM who were treated with
conventional-dose chemotherapy, interphase FISH for 13q14, 17p13, and 11q
provides prognostically relevant information in addition to that provided by
standard prognostic factors. This observation may be considered for risk-adapted
stratifications of MM patients in future clinical trials.
PMID- 10673523
TI - Racial differences in the survival of childhood B-precursor acute lymphoblastic
leukemia: a Pediatric Oncology Group Study.
AB - PURPOSE: We conducted a historic cohort study to test the hypothesis that, after
adjustment for biologic factors, African-American (AA) children and Spanish
surname (SS) children with newly diagnosed B-precursor acute lymphoblastic
leukemia had lower survival than did comparable white children. PATIENTS AND
METHODS: From 1981 to 1994, 4,061 white, 518 AA, and 507 SS children aged 1 to 20
years were treated on three successive Pediatric Oncology Group multicenter
randomized clinical trials. RESULTS: AA and SS patients were more likely to have
adverse prognostic features at diagnosis and lower survival than were white
patients. The 5-year cumulative survival rates were (probability +/- SE) 81.9% +/
0.6%, 68.6% +/- 2.1%, and 74.9% +/- 2.0% for white, AA, and SS children,
respectively. Adjusting for age, leukocyte count, sex, era of treatment, and
leukemia blast cell ploidy, we found that AA children had a 42% excess mortality
rate compared with white children (proportional hazards ratio [PHR] = 1.42; 95%
confidence interval [CI], 1.12 to 1. 80), and SS children had a 33% excess
mortality rate compared with white children (PHR = 1.33; 95% CI, 1.19 to 1.49).
CONCLUSION: Clinical presentation, tumor biology, and deviations from prescribed
therapy did not explain the differences in survival and event-free survival that
we observed, although differences seem to be diminishing over time with
improvements in therapy. The disparity in outcome for AA and SS children is most
likely related to variations in chemotherapeutic response to therapy and not to
compliance. Further improvements in outcome may require individualized dosing
based on specific pharmacogenetic profiles, especially for AA and SS children.
PMID- 10673524
TI - Silent lacunar lesions detected by magnetic resonance imaging of children with
brain tumors: a late sequela of therapy.
AB - BACKGROUND: Cerebral lacunes, which generally appear on magnetic resonance
imaging as foci of white matter loss, usually occur in adults after ischemic
infarcts. We report the development of lacunes in children after therapy for
brain tumors. PATIENTS AND METHODS: We reviewed the clinical characteristics and
radiologic studies of 524 consecutive children with brain tumors treated over a
10-year period. We documented the neuropsychologic findings associated with
lacunes and the factors predictive of lacunar development. RESULTS: Lacunes
developed in none of the 103 patients observed or treated with surgery alone.
Twenty-five of the 421 patients treated with chemotherapy or radiation therapy or
both had lacunes. Patients were a median of 4.5 years old at the time of both
diagnosis (range, 0.3 to 19.8 years) and radiotherapy (range, 1.5 to 20 years).
Fourteen patients were treated with craniospinal irradiation, and 11 were treated
with local radiotherapy. The median time from radiotherapy to the appearance of
lacunes was 2.01 years (range, 0.26 to 5.7 years). For all patients, lacunes were
an incidental finding with no corresponding clinical deficits. The factor most
predictive of lacunar development was age less than 5 years at the time of
radiotherapy (P =.010). There was no significant difference in estimated decline
in intelligence quotient scores between patients with lacunes and age and
diagnosis-matched controls. CONCLUSION: Lacunes may be caused by therapy-induced
vasculopathy in children with brain tumors, with the most significant predictor
being age less than 5 years at the time of radiotherapy.
PMID- 10673525
TI - Primary mediastinal germ cell tumors in children and adolescents: results of the
German cooperative protocols MAKEI 83/86, 89, and 96.
AB - PURPOSE: To evaluate children and adolescents with primary mediastinal teratoma
and malignant germ cell tumors (GCTs). PATIENTS AND METHODS: Forty-seven patients
from the German nontesticular GCT studies were analyzed (median age, 2.5 years;
range, neonate to 17 years). Teratoma (n = 21) were resected, and no adjuvant
treatment was given. Malignant GCTs (n = 26) were treated with cisplatin-based
chemotherapy and resection. Three of 26 patients underwent radiotherapy. RESULTS:
In all patients with teratoma, tumor markers were normal. Surgery of teratoma was
complete in 17 of 21 patients and microscopically incomplete in four of 21
patients, and we observed no relapse after a median follow-up of 29 months. In 23
of 26 patients with malignant GCTs, alpha-fetoprotein and/or beta-human chorionic
gonadotropin were elevated. Twelve of 26 patients received adjuvant chemotherapy
after initial resection, which was complete in six of 12 patients, whereas
delayed resection after preoperative chemotherapy was complete in 10 of 11
patients (P =.03). Four of six patients underwent second-look thoracotomy after
incomplete primary surgery. Three of 26 patients did not undergo tumor resection.
The final completeness of resection was the strongest prognostic indicator (event
free survival ?EFS, 0.94 +/- 0.06 v 0.42 +/- 0.33; P <.002). Local stage and
distant metastases were not prognostically significant at the.05 level. For all
malignant GCTs, the 5-year survival rate was 0.87 +/- 0.05 (median follow-up, 51
months), with an EFS of 0.83 +/- 0.05. CONCLUSION: The prognosis of mediastinal
teratoma is excellent after complete or microscopically incomplete resection. In
children with malignant GCT, the prognosis is favorable with a therapeutic
strategy of delayed resection after preoperative chemotherapy. In most children,
the diagnosis can be based on elevated tumor markers and imaging. Biopsy is
indicated in nonsecreting GCT.
PMID- 10673526
TI - Phase I evaluation of sequential doxorubicin gemcitabine then ifosfamide
paclitaxel cisplatin for patients with unresectable or metastatic transitional
cell carcinoma of the urothelial tract.
AB - PURPOSE: This phase I trial sought to evaluate the toxicity of and determine the
maximum-tolerated dose (MTD) for the two-drug regimen doxorubicin and gemcitabine
(AG) followed by the three-drug regimen of ifosfamide, paclitaxel, and cisplatin
(ITP) in patients with unresectable or metastatic transitional-cell carcinoma.
PATIENTS AND METHODS: Patients received AG every other week for six cycles
followed by ITP every 3 weeks for four cycles. Five AG dose levels were
investigated, up to doxorubicin 50 mg/m(2) and gemcitabine 2, 000 mg/m(2), to
determine the MTD of the regimen. The dose and schedule of ITP were constant:
ifosfamide 1,500 mg/m(2) (days 1 to 3); paclitaxel 200 mg/m(2) (day 1); and
cisplatin 70 mg/m(2) (day 1). Granulocyte colony-stimulating factor was given
between all cycles of therapy. RESULTS: Fifteen patients enrolled onto this phase
I trial. AG was well tolerated at all dose levels, with no grade 3 or 4
myelosuppression. Toxicity experienced with ITP included grade 3 and 4
granulocytopenia in four patients and grade 3 nausea/vomiting in three patients.
No grade 3 and 4 neurotoxicity was observed. Eight of 14 assessable patients
experienced a major response to AG, including five of six patients treated at the
two highest AG dose levels. After completion of AG-ITP, nine of 14 assessable
patients had a major response (three complete responses and six partial
responses). CONCLUSION: AG is a well-tolerated and active regimen. Sequential
chemotherapy with AG-ITP is also well tolerated, and phase II investigation at
the highest dose level is ongoing.
PMID- 10673527
TI - Hormonal predictors of prostate cancer: a meta-analysis.
AB - PURPOSE: Although there is strong circumstantial evidence that androgens are
implicated in the etiology of prostate cancer, epidemiologic investigations have
failed to demonstrate consistently that one or more steroid hormones are
implicated. In contrast, recent epidemiologic studies unequivocally link serum
insulin-like growth factor 1 (IGF-1) levels with risk for prostate cancer.
METHODS: We have performed the first meta-analysis of all previously published
studies on hormonal predictors of risk for prostate cancer. RESULTS: A meta
analysis restricted to studies that performed mutual adjustment for all measured
serum hormones, age, and body mass index indicated that men whose total
testosterone is in the highest quartile are 2.34 times more likely to develop
prostate cancer (95% confidence interval, 1.30 to 4.20). In contrast, levels of
dihydrotestosterone and estradiol do not seem to play a role of equal importance.
The only study that provides multivariably adjusted sex hormone-binding globulin
data indicates that this binding protein is inversely related to prostate cancer
risk (odds ratio, 0.46; 95% confidence interval, 0.24 to 0.89). Finally, all
three studies that examined the role of serum IGF-1 have consistently
demonstrated a positive and significant association with prostate cancer risk
that is similar in magnitude to that of testosterone. CONCLUSION: Men with either
serum testosterone or IGF-1 levels in upper quartile of the population
distribution have an approximately two-fold higher risk for developing prostate
cancer.
PMID- 10673528
TI - Etoposide and cisplatin/etoposide, methotrexate, and actinomycin D (EMA)
chemotherapy for patients with high-risk gestational trophoblastic tumors
refractory to EMA/cyclophosphamide and vincristine chemotherapy and patients
presenting with metastatic placental site trophoblastic tumors.
AB - PURPOSE: To evaluate the results of etoposide, cisplatin/etoposide, methotrexate,
and actinomycin D (EP/EMA) chemotherapy in patients with gestational
trophoblastic tumors (GTTs), who have relapsed after or who have become
refractory to EMA/cyclophosphamide and vincristine (CO) chemotherapy, and in
patients presenting with metastatic placental site trophoblastic tumors (PSTTs).
PATIENTS AND METHODS: We have treated a total of 34 patients with GTT and eight
patients with metastatic PSTT with the EP/EMA chemotherapy schedule. RESULTS:
Twenty-two patients received EP/EMA because of apparent drug resistance to
EMA/CO, and because the human chorionic gonadotropin (hCG) was near normal, they
were not assessable for response. Twenty-one of these patients (95%) are alive
and in remission. In the group where the hCG was high enough to confirm a
response (greater than one log fall in hCG) to EP/EMA, all 12 patients responded
and nine of these patients (75%) are alive and in remission. We have treated
three patients with PSTT where the interval from antecedent pregnancy was less
than 2 years, and all patients (100%) are alive and in remission. We have treated
five patients where the interval from antecedent pregnancy was greater than 2
years and one fifth (20%) remain in remission. The survival for patients with GTT
is 30 (88%) out of 34 patients and four (50%) out of eight patients for PSTT,
giving an overall survival for these two cohorts of 34 (81%) out of 42 patients.
The toxicity of this schedule is significant, with grade 3 or 4 toxicity
(National Cancer Institute common toxicity criteria) recorded in hemoglobin
(21%), WBC (68%), and platelets (40%). The role of surgery in this group of
patients is important and contributed to sustained remission in five patients
(23%) and possibly helped an additional seven patients (32%). CONCLUSION: EP/EMA
is an effective but moderately toxic regimen for patients with high-risk GTT who
become refractory to or relapse from EMA/CO chemotherapy. Also, EP/EMA clearly
has activity in patients with metastatic PSTT.
PMID- 10673529
TI - Preoperative chemoradiation for patients with pancreatic cancer: toxicity of
endobiliary stents.
AB - PURPOSE: A recent multicenter study of preoperative chemoradiation and
pancreaticoduodenectomy for localized pancreatic adenocarcinoma suggested that
biliary stent-related complications are frequent and severe and may prevent the
delivery of all components of multimodality therapy in many patients. The present
study was designed to evaluate the rates of hepatic toxicity and biliary stent
related complications and to evaluate the impact of this morbidity on the
delivery of preoperative chemoradiation for pancreatic cancer at a tertiary care
cancer center. PATIENTS AND METHODS: Preoperative chemoradiation was used in 154
patients with resectable pancreatic adenocarcinoma (142 patients, 92%) or other
periampullary tumors (12 patients, 8%). Patients were treated with preoperative
fluorouracil (115 patients), paclitaxel (37 patients), or gemcitabine (two
patients) plus concurrent rapid-fractionation (30 Gy; 123 patients) or standard
fractionation (50.4 Gy; 31 patients) radiation therapy. The incidences of hepatic
toxicity and biliary stent-related complications were evaluated during
chemoradiation and the immediate 3- to 4-week postchemoradiation preoperative
period. RESULTS: Nonoperative biliary decompression was performed in 101 (66%) of
154 patients (endobiliary stent placement in 77 patients and percutaneous
transhepatic catheter placement in 24 patients). Stent-related complications
(occlusion or migration) occurred in 15 patients. Inpatient hospitalization for
antibiotics and stent exchange was necessary in seven of 15 patients (median
hospital stay, 3 days). No patient experienced uncontrolled biliary sepsis,
hepatic abscess, or stent-related death. CONCLUSION: Preoperative chemoradiation
for pancreatic cancer is associated with low rates of hepatic toxicity and
biliary stent-related complications. The need for biliary decompression is not a
clinically significant concern in the delivery of preoperative therapy to
patients with localized pancreatic cancer.
PMID- 10673530
TI - Phase II evaluation of preoperative chemoradiation and postoperative adjuvant
chemotherapy for squamous cell and adenocarcinoma of the esophagus.
AB - PURPOSE: This phase II trial evaluated continuous-infusion cisplatin and
fluorouracil (5-FU) with radiotherapy followed by esophagectomy. The objectives
of this trial were to determine the complete pathologic response rate, survival
rate, toxicity, pattern of failure, and feasibility of administering adjuvant
chemotherapy in patients with resectable cancer of the esophagus treated with
preoperative chemoradiation. PATIENTS AND METHODS: Patients were staged using
computed tomography, endoscopic ultrasound, and laparoscopy. The preoperative
treatment plan consisted of continuous intravenous infusion of cisplatin and 5-FU
and a total dose of 44 Gy of radiation. Esophagogastrectomy was planned for
approximately 4 weeks after the completion of chemoradiotherapy. Paclitaxel and
cisplatin were administered as postoperative adjuvant therapy. RESULTS: Forty-two
patients were enrolled onto the trial. Of the 39 patients who proceeded to
surgery, 29 responded to preoperative treatment: 11 achieved pathologic complete
response (CR) and 18 achieved a lower posttreatment stage. Five patients had no
change in stage, whereas eight had progressive disease (four with distant
metastases and four with increases in the T and N stages). At a median follow-up
of 30.2 months, the median survival time has not been reached and the 2-year
survival rate is 62%. The median survival of pathologic complete responders has
not been reached, whereas the 2-year survival rate of this group is 91% compared
with 51% in patients with complete tumor resection with residual tumor (P =.03).
CONCLUSION: An excellent survival rate, comparable to that of our prior
preoperative trial, was achieved with lower doses of preoperative cisplatin and 5
FU concurrent with radiotherapy.
PMID- 10673531
TI - How Do head and neck cancer patients prioritize treatment outcomes before
initiating treatment?
AB - PURPOSE: To determine, pretreatment, how head and neck cancer (HNC) patients
prioritize potential treatment effects in relationship to each other and to
survival and to ascertain whether patients' preferences are related to
demographic or disease characteristics, performance status, or quality of life
(QOL). PATIENTS AND METHODS: One hundred thirty-one patients were assessed
pretreatment using standardized measures of QOL (Functional Assessment of Cancer
Therapy-Head and Neck) and performance (Performance Status Scale for Head and
Neck Cancer). Patients were also asked to rank a series of 12 potential HNC
treatment effects. RESULTS: Being cured was ranked top priority by 75% of
patients; another 18% ranked it second or third. Living as long as possible and
having no pain were placed in the top three by 56% and 35% of patients,
respectively. Items that were ranked in the top three by 10% to 24% of patients
included those related to energy, swallowing, voice, and appearance. Items
related to chewing, being understood, tasting, and dry mouth were placed in the
top three by less than 10% of patients. Excluding the top three rankings, there
was considerable variability in ratings. Rankings were generally unrelated to
patient or disease characteristics, with the exception that cure and living were
of slightly lower priority and pain of higher priority to older patients compared
with younger patients. CONCLUSION: The data suggest that, at least pretreatment,
survival is of primary importance to patients, supporting the development of
aggressive treatment strategies. In addition, results highlight individual
variability and warn against making assumptions about patients' attitudes vis-a
vis potential outcomes. Whether patients' priorities will change as they
experience late effects is currently under investigation.
PMID- 10673533
TI - Depression in patients with lung cancer: prevalence and risk factors derived from
quality-of-life data.
AB - PURPOSE: To evaluate self-reported depression rates in patients with inoperable
lung cancer and to explore demographic, clinical, and quality-of-life (QOL)
factors associated with depression and thus identify patients at risk. PATIENTS
AND METHODS: Nine hundred eighty-seven patients from three palliative treatment
trials conducted by the Medical Research Council Lung Cancer Working Party formed
the study sample. 526 patients (53%) had poor prognosis small-cell lung cancer
(SCLC) and 461 patients (47%) had good prognosis non-small-cell lung cancer
(NSCLC). Hospital Anxiety and Depression Scale data and QOL items from the
Rotterdam Symptom Checklist were analyzed, together with relevant demographic and
clinical factors. RESULTS: Depression was self-rated in 322 patients (33%) before
treatment and persisted in more than 50% of patients. SCLC patients had a three
fold greater prevalence of case depression than those with NSCLC (25% v 9%; P
<.0001). An increased rate for women was found for good performance status (PS)
patients (PS of 0 or 1) but the sex difference reduced for poor PS patients (PS
of 3 or 4) because of increased depression rates for men (chi(2) for trend, P
<.0001). Multivariate analysis showed that functional impairment was the most
important risk factor; depression increased by 41% for each increment on the
impairment scale. Pretreatment physical symptom burden, fatigue, and clinician
rated PS were also independent predictors, but cell type was not. CONCLUSION:
Depression is common and persistent in lung cancer patients, especially those
with more severe symptoms or functional limitations. Psychologic screening and
appropriate intervention is an essential part of palliative care.
PMID- 10673532
TI - Neoadjuvant chemotherapy for peripheral malignant neuroectodermal tumor of bone:
recent experience at the istituto rizzoli.
AB - PURPOSE: The results achieved in 44 patients with nonmetastatic peripheral
neuroectodermal tumor (PNET) of bone treated with neoadjuvant chemotherapy are
reported. PATIENTS AND METHODS: A six-drug regimen of chemotherapy (vincristine,
doxorubicin, dactinomycin, cyclophosphamide, ifosfamide, and etoposide) was
administered to all patients. Local treatment consisted of surgery in 20
patients, surgery followed by radiotherapy in 13, and radiotherapy only in 11.
RESULTS: At a mean follow-up of 4.5 years (range, 2 to 7 years), 23 patients
(52%) remain event-free, 20 have relapsed (45%), and one has died of chemotherapy
related toxicity. The 5-year event-free survival and overall survival were 54.2%
and 62.7%, respectively. To assess the prognostic significance of neural
differentiation in the family of Ewing's sarcoma, these results have been
compared with the outcomes of 138 concomitant patients with typical Ewing's
sarcoma (TES) who were treated according to the same protocol. Of these, 103
(75%) remained continuously event-free, 34 (24%) relapsed, and one died of
chemotherapy-related toxicity. It follows that PNET patients treated with this
chemotherapy regimen have a significantly worse prognosis than typical ES
patients (5-year event-free survival, 54.2% v 70.6%, P <.012; 5-year overall
survival, 62.7% v 78.3%, P <.002). CONCLUSION: The authors conclude that studies
into new adjuvant therapy for Ewing's sarcoma modulated according to risk of
relapse should also consider neural differentiation as a risk factor.
PMID- 10673534
TI - Phase I studies of anti-epidermal growth factor receptor chimeric antibody C225
alone and in combination with cisplatin.
AB - PURPOSE: The epidermal growth factor (EGF) receptor is frequently overexpressed
in epithelial tumors. C225 is a human-to-murine chimeric monoclonal antibody that
binds to the receptor and inhibits growth of cancer cells expressing the
receptor. We evaluated the pharmacokinetics and toxicity of C225 in patients with
advanced tumors overexpressing EGF receptors. PATIENTS AND METHODS: We treated 52
patients in three successive phase I clinical trials of C225 as a single dose (n
= 13), weekly multiple dose (n = 17), and weekly multiple dose with cisplatin (n
= 22). C225 dose levels were 5, 20, 50, and 100 mg/m(2). In the study combining
C225 with cisplatin, limited to patients with either head and neck or non-small
cell lung cancer, C225 was further escalated to 200 and 400 mg/m(2). Cisplatin
was given at a dose of 60 mg/m(2) once every 4 weeks, and treatment was continued
for up to 12 weeks if no disease progression occurred. RESULTS: C225 displayed
nonlinear pharmacokinetics, with antibody doses in the range of 200 to 400
mg/m(2) being associated with complete saturation of systemic clearance. C225
clearance did not change with repeated administration or with coadministration of
cisplatin. Antibodies against C225 were detected in only one patient, and C225
associated toxicity was minimal. Patients experiencing disease stabilization were
seen in all studies. In the study combining C225 and cisplatin, nine (69%) of 13
patients treated with antibody doses >/= 50 mg/m(2) completed 12 weeks of
therapy, and two partial responses were observed. CONCLUSION: C225 has dose
dependent pharmacokinetics, and doses that achieve saturation of systemic
clearance are well tolerated. C225 given in combination with cisplatin has
biologic activity at pharmacologically relevant doses.
PMID- 10673535
TI - Phase I and pharmacologic study of oral fluorouracil on a chronic daily schedule
in combination with the dihydropyrimidine dehydrogenase inactivator eniluracil.
AB - PURPOSE: To determine the maximum-tolerated dose (MTD), toxicities, and
pharmacokinetics of oral fluorouracil (5-FU) administered twice daily in
combination with oral eniluracil, an inactivator of dihydropyrimidine
dehydrogenase, administered for 28 days every 35 days. PATIENTS AND METHODS: Oral
5-FU 1.35 mg/m(2) twice daily was administered with oral eniluracil 10 mg daily
for 14 to 28 days, followed by a 1-week rest period. Eniluracil was started 1 day
before 5-FU. Patients then received escalated doses of oral 5-FU 1. 35 to 1.8
mg/m(2) twice daily with an increased dose of eniluracil 10 mg twice daily for 28
days. A reduced dose of 5-FU 1.0 mg/m(2) with eniluracil 20 mg twice daily was
evaluated. RESULTS: Thirty-six patients with solid malignancies were enrolled
onto the study. Diarrhea was the principal dose-limiting toxicity of oral 5-FU
and eniluracil given on this chronic schedule. The recommended phase II dose is 5
FU 1.0 mg/m(2) twice daily with eniluracil 20 mg twice daily. Mean (SD) values
for terminal half-life, apparent volume of distribution, and systemic clearance
of 4.5 hours (0.83 hours), 19 L/m(2) (3.0 L/m(2)), and 51 mL/min/m(2) (13
mL/min/m(2)), respectively. An average of 77% of 5-FU was excreted unchanged in
urine after 28 days of treatment. The mean (range) 5-FU C(SS,min) values achieved
at the 1.0 mg/m(2) dose level were 22 ng/mL (8 to 38 ng/mL). CONCLUSION: Chronic
oral administration of 5-FU with oral eniluracil is tolerable and produces 5-FU
steady-state concentrations similar to those achieved with protracted intravenous
administration of 5-FU on clinically relevant dose schedules. Eniluracil provides
an attractive means of administering 5-FU on protracted schedules.
PMID- 10673537
TI - Sector resection for stage I breast cancer.
PMID- 10673536
TI - Phase I and pharmacokinetic study of farnesyl protein transferase inhibitor
R115777 in advanced cancer.
AB - PURPOSE: To determine the maximum-tolerated dose, toxicities, and pharmacokinetic
profile of the farnesyl protein transferase inhibitor R115777 when administered
orally bid for 5 days every 2 weeks. PATIENTS AND METHODS: Twenty-seven patients
with a median age of 58 years received 85 cycles of R115777 using an intrapatient
and interpatient dose escalation schema. Drug was administered orally at
escalating doses as a solution (25 to 850 mg bid) or as pellet capsules (500 to
1300 mg bid). Pharmacokinetics were assessed after the first dose and the last
dose administered during cycle 1. RESULTS: Dose-limiting toxicity of grade 3
neuropathy was observed in one patient and grade 2 fatigue (decrease in two
performance status levels) was seen in four of six patients treated with 1,300 mg
bid. The most frequent clinical grade 2 or 3 adverse events in any cycle included
nausea, vomiting, headache, fatigue, anemia, and hypotension. Myelosuppression
was mild and infrequent. Peak plasma concentrations of R115777 were achieved
within 0.5 to 4 hours after oral drug administration. The elimination of R115777
from plasma was biphasic, with sequential half-lives of about 5 hours and 16
hours. There was little drug accumulation after bid dosing, and steady-state
concentrations were achieved within 2 to 3 days. The pharmacokinetics were dose
proportional in the 25 to 325 mg/dose range for the oral solution. Urinary
excretion of unchanged R115777 was less than 0.1% of the oral dose. One patient
with metastatic colon cancer treated at the 500-mg bid dose had a 46% decrease in
carcinoembryonic antigen levels, improvement in cough, and radiographically
stable disease for 5 months. CONCLUSION: R115777 is bioavailable after oral
administration and has an acceptable toxicity profile. Based upon pharmacokinetic
data, the recommended dose for phase II trials is 500 mg orally bid (total daily
dose, 1, 000 mg) for 5 consecutive days followed by 9 days of rest. Studies of
continuous dosing and studies of R115777 in combination with chemotherapy are
ongoing.
PMID- 10673538
TI - The logic of evidence.
PMID- 10673539
TI - Radiation for early-stage Hodgkin's disease?
PMID- 10673540
TI - Swelling-activated, cystic fibrosis transmembrane conductance regulator-augmented
ATP release and Cl- conductances in murine C127 cells.
AB - 1. A hypotonic challenge, but not cAMP stimulation, was found to induce release
of ATP measured by the luciferin-luciferase assay from both the murine mammary
carcinoma cell line C127i and C127 cells stably transfected with the cDNA for
human cystic fibrosis transmembrane conductance regulator (CFTR) protein
(C127/CFTR). CFTR expression augmented swelling-induced ATP release by 10-20
times under hypotonic conditions (< or = 80 % osmolality). 2. Glibenclamide
failed to suppress swelling-induced ATP release from C127/CFTR cells. In
contrast, whole-cell patch-clamp recordings showed that both the cAMP-activated
ohmic Cl- currents and volume-sensitive outwardly rectifying (VSOR) Cl- currents
were prominently suppressed by glibenclamide. 3. Gd3+ markedly blocked swelling
induced ATP release but failed to suppress both cAMP- and swelling-activated Cl-
currents in the CFTR-expressing cells. Even after pretreatment and during
treatment with Gd3+, VSOR Cl- currents were activated normally. 4. The continuous
presence of an ATP-hydrolysing enzyme, apyrase, in the bathing solution did not
prevent activation of VSOR Cl- currents in C127/CFTR cells. 5. The rate of
regulatory volume decrease (RVD) in C127/CFTR cells was much faster than that in
C127i cells. When apyrase was added to the bathing solution, the RVD rate was
retarded in C127/CFTR cells. 6. On balance, the following conclusions can be
deduced. First, swelling-induced ATP release is augmented by expression of CFTR
but is not mediated by the CFTR Cl- channel. Second, swelling-induced ATP release
is not mediated by the VSOR Cl- channel. Third, the released ATP facilitated the
RVD process but is not involved in the activation of VSOR Cl- channels in
C127/CFTR cells.
PMID- 10673541
TI - Heterodimeric amino acid transporters: expression of heavy but not light chains
of CD98 correlates with induction of amino acid transport systems in human
placental trophoblast.
AB - 1. Activity of amino acid transport and relative abundance of mRNAs encoding
related transporters have been studied in parallel either before or following in
vitro culture of explants of human placental chorionic villi. 2. Amino acid
transport activities through systems L (1.9-fold), y+L (2.6-fold) and y+ (3.2
fold) were markedly enhanced following culture for 48 h. 3. Relative mRNA
abundance (determined by reverse transcription-polymerase chain reaction) for the
heavy chain of CD98 surface antigen and for the cationic amino acid transporter-1
were similarly stimulated (2.8-fold and 2.6-fold, respectively). In contrast,
none of the mRNA levels for light chains of CD98 (system L-amino acid transporter
1, system L-amino acid transporter-2, system y+L-amino acid transporter-1 and
system y+L-amino acid transporter-2) studied nor for the cationic amino acid
transporter-2B were altered.
PMID- 10673543
TI - Effects of cytosolic ATP on spontaneous and triggered Ca2+-induced Ca2+ release
in permeabilised rat ventricular myocytes.
AB - 1. The effects of cytosolic ATP on sarcoplasmic reticulum (SR) Ca2+ regulation
were investigated in saponin-permeabilised rat ventricular myocytes. [Ca2+]
within the cells was monitored using Fura-2 or Fluo-3 fluorescence. Spontaneous
cyclic Ca2+ release from the SR was induced by increasing the bathing [Ca2+] to
200-300 nM, in solutions weakly Ca2+ buffered with 0.05 mM EGTA. Alternatively,
Ca2+-induced Ca2+ release (CICR) was triggered by a rapid increase in [Ca2+]
induced by flash photolysis of Nitr-5 (0.08 mM), replacing EGTA in the solution.
2. Stepwise reductions in [ATP] were associated with corresponding decreases in
the frequency and increases in the amplitude of spontaneous Ca2+ transients. A
decrease from 5 mM to 0. 1 mM ATP, reduced the release frequency by 48.6 +/- 7 %
(n = 7) and almost doubled the amplitude of the Ca2+ transient. Marked
prolongation of the spontaneous Ca2+ transient occurred when [ATP] was further
reduced to 10 microM, consistent with inhibition of the SR Ca2+ pump. 3. These
effects of ATP were compared with other interventions that inhibit Ca2+ uptake or
reduce the sensitivity of the SR Ca2+ release mechanism. Inhibition of the SR
Ca2+ pump with cyclopiazonic acid (CPA) markedly reduced the spontaneous Ca2+
release frequency, without changing the amplitude. The descending phase of the
Ca2+ transient was prolonged in the presence of CPA, while the rising phase was
unaffected. In contrast, desensitisation of the SR Ca2+ release mechanism with
tetracaine decreased the frequency of spontaneous release, but markedly increased
the amplitude. 4. CICR triggered by flash photolysis of Nitr-5 appeared to be
more sensitive to cytosolic [ATP] than spontaneous release and was generally
delayed by a decrease to 2.5 mM ATP. In the presence of 0.1-0.2 mM ATP, release
often failed completely or was not consistently triggered. Some preparations
exhibited Ca2+ release 'alternans', whereby every alternate trigger induced a
response. 5. These results suggest that the increase in spontaneous Ca2+ release
amplitude and the decrease in frequency that occurs as [ATP] is reduced from 1 mM
to 100 microM, is mainly due to desensitisation of the SR Ca2+ release mechanism,
which allows the SR Ca2+ content to reach a higher level before release occurs.
At very low [ATP], a reduction in the SR Ca2+ uptake rate may also contribute to
the decrease in release frequency. CICR triggered by photolysis of Nitr-5
appeared to be more sensitive to cytosolic [ATP]. The possible underlying
mechanisms and the relevance of these results to myocardial ischaemia or hypoxia
is considered.
PMID- 10673542
TI - Reversible Ca2+-induced fast-to-slow transition in primary skeletal muscle
culture cells at the mRNA level.
AB - 1. The adult fast character and a Ca2+-inducible reversible transition from a
fast to a slow type of rabbit myotube in a primary culture were demonstrated at
the mRNA level by Northern blot analysis with probes specific for different
myosin heavy chain (MyHC) isoforms and enzymes of energy metabolism. 2. No non
adult MyHC isoform mRNA was detected after 22 days of culture. After 4 weeks of
culture the fast MyHCIId mRNA was strongly expressed while MyHCI mRNA was
virtually absent, indicating the fast adult character of the myotubes in the
primary skeletal muscle culture. 3. The data show that a fast-to-slow transition
occurred in the myotubes at the level of MyHC isoform gene expression after
treatment with the Ca2+ ionophore A23187. The effects of ionophore treatment were
decreased levels of fast MyHCII mRNA and an augmented expression of the slow
MyHCI gene. Changes in gene expression started very rapidly 1 day after the onset
of ionophore treatment. 4. Levels of citrate synthase mRNA increased and levels
of glyceraldehyde 3-phosphate dehydrogenase mRNA decreased during ionophore
treatment. This points to a shift from anaerobic to oxidative energy metabolism
in the primary skeletal muscle culture cells at the level of gene expression. 5.
Withdrawal of the Ca2+ ionophore led to a return to increased levels of MyHCII
mRNA and decreased levels of MyHCI mRNA, indicating a slow-to-fast transition in
the myotubes and the reversibility of the effect of ionophore on MyHC isoform
gene expression.
PMID- 10673544
TI - L-type calcium channel activity regulates sodium channel levels in rat pituitary
GH3 cells.
AB - 1. The effects of chronic pharmacological modulation of L-type Ca2+ channel
activity on the cell surface expression of Na+ channels were examined in GH3
cells. 2. Prolonged inhibition (4-5 days) of L-channels with nimodipine caused a
50-60 % decrease in the peak amplitude of whole-cell Na+ currents recorded with
the patch-clamp technique. On the contrary, prolonged exposure to the L-channel
agonist Bay K 8644 induced an approximately 2.5-fold increase in peak Na+
current. In both cases, there were only minor changes in cell capacitance and no
significant changes in Na+ channel gating properties. 3. Measurements of the
specific binding of radiolabelled saxitoxin to intact cells showed that
nimodipine treatment reduced the number of cell surface Na+ channels, whereas
treatment with Bay K 8664 produced the opposite effect. The dual regulation of
Na+ channel abundance explained the mentioned changes in Na+ current amplitude.
4. Plasma membrane Na+ channels had a half-life of approximately 17 h both in
control cells and in cells treated with Bay K 8644, as estimated from the rate of
decay of peak Na+ current after inhibition of protein synthesis with
cycloheximide. Actinomycin D, an inhibitor of gene transcription, and also
cycloheximide, occluded the stimulatory effect of Bay K 8644 on Na+ current
density when measured over a 24 h period. 5. These findings indicate that the
entry of Ca2+ through L-type channels influences in a positive way the number of
functional Na+ channels in GH3 cells, and suggest that Ca2+ influx stimulates
either Na+ channel gene expression or the expression of a regulatory protein that
promotes translocation of pre-assembled Na+ channels into the plasma membrane.
PMID- 10673545
TI - Ca2+ influx via the L-type Ca2+ channel during tail current and above current
reversal potential in ferret ventricular myocytes.
AB - 1. Current through L-type Ca2+ channels (ICa) was measured electrophysiologically
at the same time as Ca2+ influx was measured by trapping entering Ca2+ with a
high concentration of indo-1 (> 1 mM) in ferret ventricular myocytes. 2. Na+-free
conditions prevented Na+-Ca2+ exchange and K+ currents were blocked by Cs+ and
TEA. Thapsigargin (5 microM) prevented Ca2+ uptake and release by the
sarcoplasmic reticulum. ICa was pre-activated by brief pulses to +120 mV (the
equilibrium potential for Ca2+, ECa), followed by steps to different membrane
potentials (Em, -80 to +100 mV), in some cases in the presence of the Ca2+
channel agonist FPL-64176. 3. Integrated ICa ( 82 ICa) was linearly related to
the change in the concentration of Ca2+ bound to indo-1, which was assessed by
the fluorescence difference signal DeltaFd (Fd = F500 - F400). This created an
internal calibration of DeltaFd as a measure of Ca2+ influx. 4. The DeltaFd/ 82
ICadt relationship was virtually unchanged at all measurable inward ICa (at Em
from -80 to +50 mV). This indicates that the fractional current carried by Ca2+
and channel selectivity are unchanged over this Em range, and also that the
selectivity for Ca2+ is very high. 5. Ca2+ influx was readily detected by DeltaFd
beyond the ICa reversal potential (+65 to +100 mV) and was not abolished until Em
was +120 mV (i.e. ECa). This is explained by the fact that inward Ca2+ flux at
the ICa reversal potential is exactly balanced by outward Cs+ current through the
Ca2+ channels and can be described by classic Goldman flux analysis with a
Ca2+/Cs+ selectivity of the order of 5000. 6. This result also emphasizes that
net Ca2+ influx via Ca2+ channels occurs over a voltage range where the net
channel current is outward.
PMID- 10673546
TI - Calcium-, voltage- and osmotic stress-sensitive currents in Xenopus oocytes and
their relationship to single mechanically gated channels.
AB - 1. Patch recordings from Xenopus oocytes indicated that mechanically gated (MG)
channels are expressed at a uniform surface density ( approximately 1 channel
microm-2) with an estimated > 3 x 106 MG channels per oocyte that could generate
microamps of current at +/-50 mV. 2. Removal of external Ca2+ induced a membrane
conductance that differed from MG channels in ion selectivity, pharmacology and
sensitivity to connexion-38. 3. Depolarization to +50 mV activated a Na+
selective, a Cl--selective and a non-selective conductance. Hyperpolarization to
150 mV activated a non-selective conductance. None of these conductances appeared
to be mediated by MG channels. 4. Hypotonicity (25 %) failed to evoke any change
in membrane conductance in the majority of defolliculated oocytes. Hypertonicity
(200 %) evoked a large non-selective (PK /PCl approximately 1) membrane
conductance that was not blocked by 100 microM Gd3+. 5. Although the above
stimuli could activate a variety of whole-oocyte conductances, including three
novel conductances, they did not involve MG channel activation. Possible
mechanisms underlying the discrepancy between observed conductances and those
anticipated from patch-clamp studies are discussed.
PMID- 10673547
TI - On the discrepancy between whole-cell and membrane patch mechanosensitivity in
Xenopus oocytes.
AB - 1. Mechanical stimulation of voltage-clamped Xenopus oocytes by inflation,
aspiration, or local indentation failed to activate an increase in membrane
conductance up to the point of causing visible oocyte damage. 2. The absence of
mechanosensitivity is not due to the vitelline membrane, rapid MG channel
adaptation or tension-sensitive recruitment of new membrane. 3. Membrane
capacitance measurements indicate that the oocyte surface area is at least 5
times larger than that predicted assuming a smooth sphere. We propose that this
excess membrane area provides an immediate reserve that can 'buffer' membrane
tension changes and thus prevent MG channel activation. 4. High-resolution images
of tightly sealed patches and patch capacitance measurements indicate a smooth
membrane that is pulled flat and perpendicular across the inside of the pipette.
Brief steps of pressure or suction cause rapid and reversible membrane flexing
and MG channel activation. 5. We propose that changes in membrane geometry
induced during cell growth and differentiation or as a consequence of specific
physiological and pathological conditions may alter mechanosensitivity of a cell
independently of the intrinsic properties of channel proteins.
PMID- 10673548
TI - Mechanically gated channel activity in cytoskeleton-deficient plasma membrane
blebs and vesicles from Xenopus oocytes.
AB - 1. A novel technique involving hypertonic stress causes membrane 'blebbing' of
the Xenopus oocyte and the shedding of plasma membrane vesicles (PMVs). 2.
Confocal fluorescence microscopy, immunocytochemistry and electron microscopy
indicate that blebs and PMVs lack cortical cytoskeleton and are deficient in
cytoskeleton proteins and devoid of microvilli. 3. Patch recordings from PMVs
consistently reveal mechanically gated (MG) channel activity. The MG channels
display the same single-channel conductance as control recordings but differ in
terms of reduced mechanosensitivity and adaptation to sustained stimulation. 4.
Whole PMV recordings show rapid and reversible activation of mechanosensitive
currents in response to pressure pulses. The maximal currents activated in PMVs
are consistent with MG channel activity recorded in patches. 5. The discrepancy
between MG channel activity recorded in whole PMVs and oocytes most probably
reflects their different membrane geometry and ability to develop activating
bilayer tensions. 6. We propose that membrane blebbing, which is known to occur
under specific physiological and pathological conditions (e.g. mitosis and
apoptosis), may increase mechanosensitivity independently of the intrinsic
properties of membrane proteins.
PMID- 10673549
TI - Signalling pathway for histamine activation of non-selective cation channels in
equine tracheal myocytes.
AB - 1. The signalling pathway underlying histamine activation of non-selective cation
channels was investigated in single equine tracheal myocytes. Application of
histamine (100 microM) activated the transient calcium-activated chloride current
(ICl(Ca)) and sustained, low amplitude non-selective cation current (ICat). The
H1 receptor antagonist pyrilamine (10 microM) blocked activation of ICl(Ca) and
ICat. Simultaneous application of histamine (100 microM) and caffeine (8 mM)
during H1 receptor blockade activated ICl(Ca), but not ICat. Neither the H2
receptor antagonist cimetidine (20 microM) nor the H3 receptor antagonist
thioperamide (20 microM) prevented activation of ICl(Ca) and ICat. 2.
Intracellular dialysis of anti-Galphai/Galphao antibodies completely blocked
activation of ICat by histamine, whereas ICl(Ca) was not affected. By contrast,
anti-Galphaq/Galpha11 antibodies greatly inhibited ICl(Ca), but did not alter
activation of ICat. 3. 1-Oleoyl-2-acetyl-sn-glycerol (OAG, 20-100 microM) did not
induce any current or affect currents activated by histamine or methacholine
(mACH). Simultaneous application of OAG and caffeine activated ICl(Ca), but not
ICat, indicating that a rise in [Ca2+]i and stimulation of diacylglycerol
sensitive protein kinase C (PKC) is not sufficient to activate ICat. The
phospholipase C inhibitor U73122 (2 microM) blocked histamine activation of
ICl(Ca) and ICat, but simultaneous exposure of myocytes to histamine and caffeine
restored both ICl(Ca) and ICat in the presence of U73122. 4. Histamine and mACH
activated currents with equivalent I-V relationships. The currents activated by
these agonists were not additive; following activation of ICat by mACH, histamine
failed to induce an additional membrane current. Similarly, mACH did not induce
an additional current after full activation of ICat by histamine. 5. We conclude
that H1 histamine receptors activate ICat through coupling to Gi/Go proteins.
Activation of ICat also requires intracellular calcium release, mediated by H1
receptors coupling to Gq/G11 proteins. This coupling is analogous to the
activation of ICat by co-stimulation of M2 and M3 receptors.
PMID- 10673550
TI - Muscarinic receptor-induced acidification in sublingual mucous acinar cells: loss
of pH recovery in Na+-H+ exchanger-1 deficient mice.
AB - 1. Intracellular pH (pHi) plays an important role in regulating fluid and
electrolyte secretion by salivary gland acinar cells. The pH-sensitive,
fluorescent dye 2', 7'-bis(carboxyethyl)-5(6)-carboxylfluorescein (BCECF) was
used to characterize the mechanisms involved in regulating pHi during muscarinic
stimulation in mouse sublingual mucous acinar cells. 2. In the presence of HCO3-,
muscarinic stimulation caused a rapid decrease in pHi (0.24 +/- 0.02 pH units)
followed by a slow recovery rate (0.042 +/- 0.002 pH units min-1) to the initial
resting pHi in sublingual acinar cells. The muscarinic receptor-induced
acidification in parotid acinar cells was of a similar magnitude (0. 25 +/- 0.02
pH units), but in contrast, the recovery rate was approximately 4-fold faster
(0.181 +/- 0.005 pH units min-1). 3. The agonist-induced intracellular
acidification was inhibited by the anion channel blocker niflumate, and was
prevented in the absence of HCO3- by treatment with the carbonic anhydrase
inhibitor methazolamide. These results indicate that the muscarinic-induced
acidification is due to HCO3- loss, probably mediated by an anion conductive
pathway. 4. The Na+-H+ exchange inhibitor 5-(N-ethyl-N-isopropyl)amiloride (EIPA)
amplified the magnitude of the agonist-induced acidification and completely
blocked the Na+-dependent pHi recovery. 5. To examine the molecular nature of the
Na+-H+ exchange mechanism in sublingual acinar cells, pH regulation was
investigated in mice lacking Na+-H+ exchanger isoforms 1 and 2 (NHE1 and NHE2,
respectively). The magnitude and the rate of pHi recovery in response to an acid
load in acinar cells isolated from mice lacking NHE2 were comparable to that
observed in cells from wild-type animals. In contrast, targeted disruption of the
Nhe1 gene completely abolished pHi recovery from an acid load. These results
demonstrate that NHE1 is critical for regulating pHi during a muscarinic agonist
stimulated acid challenge and probably plays an important role in regulating
fluid secretion in the sublingual exocrine gland. 6. In NHE1-deficient mice,
sublingual acinar cells failed to recover from an acid load in the presence of
bicarbonate. These results confirm that the major regulatory mechanism involved
in pHi recovery from an acid load is not Na+-HCO3- cotransport, but amiloride
sensitive Na+-H+ exchange via isoform 1.
PMID- 10673551
TI - Cell volume regulation: the role of taurine loss in maintaining membrane
potential and cell pH.
AB - 1. In response to a hypo-osmotic stress cells undergo a regulatory volume
decrease (RVD) by losing osmotically active solutes and obliged water. During
RVD, trout red cells lost taurine, K+ and Cl- but gained Na+ and Cl-. Over the
full time course of RVD the chloride concentration in the cell water remained
remarkably constant. Thus membrane potential and cell pH, which depends on the
ratio of internal to external chloride concentration ([Cl-]i:[Cl-]o), remained
fixed. 2. When cell volume decreases it is only possible to keep the chloride
concentration in the cell water constant if an equal percentage of the cell
chloride pool and of the cell water pool are lost simultaneously. Quantitative
analysis of our data showed that this requirement was fulfilled because, over the
full time course of RVD, cells lost osmotically active solutes with a constant
stoichiometry: 1 Cl-:1 positive charge:2.35 taurine. Any change in taurine
permeability, by modifying the stoichiometric relationship, would affect the
amount of water lost and consequently cell chloride concentration. 3. Experiments
carried out with different cations as substitutes for external Na+ suggest that
the constancy of the chloride concentration is not finely tuned by some mechanism
able to modulate the channel transport capacity, but results in part from the
fact that the swelling-dependent channel constitutively possesses an adequately
fixed relative permeability for cations and taurine. However, as a significant
fraction of K+ and Cl- loss occurs via a KCl cotransporter, the contribution of
the cotransport to the stoichiometric relationship remains to be defined. 4. The
large amount of taurine released during RVD (50 % of all solutes) was shown to be
transported as an electroneutral zwitterion and not as an anion. How the channel
can accommodate the zwitterionic form of taurine, which possesses a high
electrical dipole, is considered.
PMID- 10673552
TI - Effect of hypothermia on the volume of rat glial cells.
AB - 1. The cell volume of suspended C6 glioma cells and primary cultured rat
astrocytes was measured at normothermia (37 degrees C), and at mild (32 degrees
C) and moderate (27 degrees C) hypothermia by flow cytometry with electrical cell
sizing. 2. Under control conditions (37 degrees C), C6 glioma cells had a volume
of 809 +/- 29 microm3. Moderate hypothermia (27 degrees C) led to rapid cell
swelling, with a maximum volume of 113.1 +/- 1.3 % of control being achieved
after 50 min. After rewarming to 37 degrees C, cell volume recovered very slowly
and incompletely (to 107.2 +/- 0.4 % of control). Less severe hypothermia (32
degrees C) led to a smaller increase in cell volume (108.7 +/- 0.5 % of control).
3. The maximal cell swelling response and the kinetics of swelling were similar
in C6 glioma cells and primary cultured astrocytes. 4. Hypothermia-induced cell
swelling was dependent on the presence of extracellular Na+ and was reduced by
the Na+-H+ antiporter inhibitor EIPA. 5. The underlying mechanisms of hypothermia
induced cell swelling are an intracellular accumulation of Na+ by (1)
differential effects of hypothermia on the membrane permeabilities of Na+ and K+
and (2) activation of the Na+-H+ antiporter by a shift of its activation curve to
a more alkaline value.
PMID- 10673554
TI - Weak common parallel fibre synapses explain the loose synchrony observed between
rat cerebellar golgi cells.
AB - 1. In anaesthetized rats, pairs of cerebellar Golgi cells fired synchronously at
rest, provided they were aligned along the parallel fibre axis. The observed
synchrony was much less precise, however, than that which would be expected to
result from common, monosynaptic parallel fibre excitation. 2. To explain this
discrepancy, the precision and frequency of spike synchronization (i.e. the width
and area of the central peak on the spike train cross-correlogram) were computed
in a generic model for varying input, synaptic and neuronal parameters. 3.
Correlation peaks between model neurons became broader, and peak area smaller,
when the number of afferents increased and each single synapse decreased
proportionally in strength. Peak width was inversely proportional to firing rate,
but independent of the percentage of shared afferents. Peak area, in contrast,
scaled with the percentage of shared afferents but was almost firing rate
independent. 4. Broad correlation peaks between pairs of model neurons resulted
from the loose spike timing between single model neurons and their afferents.
This loose timing reflected a need for long-term synaptic integration to fire the
neurons. Model neurons could accomplish this through firing rate adaptation
mediated by a Ca2+-activated K+ channel. 5. We conclude that loose synchrony may
be entirely explained by shared input from monosynaptic, non-synchronized
afferents. The inverse relationship between peak width and firing rate allowed us
to distinguish common parallel fibre input from firing rate covariance as a
primary cause of loose synchrony between cerebellar Golgi cells in anaesthetized
rats.
PMID- 10673553
TI - Presynaptic dopamine D2-like receptors inhibit excitatory transmission onto rat
ventral tegmental dopaminergic neurones.
AB - 1. The effects of dopamine (DA) on non-NMDA glutamatergic transmission onto
dopaminergic neurones in the ventral tegmental area (VTA) were examined in rat
midbrain slices using the whole-cell patch-clamp technique. EPSCs in dopaminergic
neurones evoked by focal stimulation within the VTA were reversibly blocked by 5
microM CNQX in the presence of bicuculline (20 microM), strychnine (0.5 microM)
and D-amino-5-phosphonopentanoic acid (D-AP5, 25 microM). 2. Bath application of
DA reduced the amplitude of EPSCs up to 65.1 +/- 9. 52% in a concentration
dependent manner between 0.3-1000 microM (IC50, 16.0 microM) without affecting
the holding current at -60 mV measured using a Cs+-filled electrode. 3. The
effect of DA on evoked EPSCs was mimicked by the D2-like receptor agonist
quinpirole but not by the D1-like receptor agonist SKF 81297, and was antagonized
by the D2-like receptor antagonist sulpiride (KB, 0.96 microM), but not by the D1
like receptor antagonist SCH 23390 (KB, 228.6 microM). 4. Dopamine (30 microM)
reduced the mean frequency of spontaneous miniature EPSCs (mEPSCs) without
affecting their mean amplitude, and the DA-induced effect on the mEPSCs was
dependent on the external Ca2+ concentration. 5. These results suggest that
afferent glutamatergic fibres which terminate on VTA dopaminergic neurones
possess presynaptic D2-like receptors, activation of which inhibits glutamate
release by reducing Ca2+ influx.
PMID- 10673555
TI - Voltage-gated currents distinguish parvocellular from magnocellular neurones in
the rat hypothalamic paraventricular nucleus.
AB - 1. Magnocellular and parvocellular neurones of the hypothalamic paraventricular
nucleus (PVN) differentially regulate pituitary hormone secretion and autonomic
output. Previous experiments have suggested that magnocellular, or type I
neurones, and parvocellular, or type II neurones, of the PVN express different
electrophysiological properties. Whole-cell patch-clamp recordings were performed
in hypothalamic slices to identify the voltage-gated currents responsible for the
electrophysiological differences between type I and type II PVN neurones. 2. Type
I neurones, which display transient outward rectification and lack a low
threshold spike (LTS), generated a large A-type K+ current (IA) (mean +/- s.e.
m.: 1127.5 +/- 126.4 pA; range: 250-3600 pA; voltage steps to -25 mV) but
expressed little or no T-type Ca2+ current (IT). Type II neurones, which lack
transient outward rectification but often display an LTS, expressed a smaller IA
(360.1 +/- 56.3 pA; range: 40-1100 pA; voltage steps to -25 mV), and 75 % of the
type II neurones generated an IT (-402.5 +/- 166.9 pA; range: -90 to -2200 pA; at
peak). 3. The voltage dependence of IA was shifted to more negative values in
type I neurones compared to type II neurones. Thus, the activation threshold (
53.5 +/- 0.9 and -46.1 +/- 2.6 mV), the half-activation potential (-25 +/- 1.9
and -17.9 +/- 2.0 mV), the half-inactivation potential (-80.4 +/- 9.3 and -67.2
+/- 3.0 mV), and the potential at which the current became fully inactivated (
57.4 +/- 2.1 and -49.8 +/- 1.5 mV) were more negative in type I neurones than in
type II neurones, respectively. 4. IT in type II neurones activated at a
threshold of -59.2 +/- 1.2 mV, peaked at -32. 6 +/- 1.7 mV, was half-inactivated
at -66.9 +/- 2.2 mV, and was fully inactivated at -52.2 +/- 2.2 mV. 5. Both cell
types expressed a delayed rectifier current with similar voltage dependence,
although it was smaller in type I neurones (389.7 +/- 39.3 pA) than in type II
neurones (586.4 +/- 76.0 pA). 6. In type I neurones IA was reduced by 41.1 +/-
7.0 % and the action potential delay caused by the transient outward
rectification was reduced by 46.2 +/- 10.3 % in 5 mM 4-aminopyridine. In type II
neurones IT was reduced by 66.8 +/- 10.9 % and the LTS was reduced by 76.7 +/-
7.8 % in 100 microM nickel chloride, but neither IT nor LTS was sensitive to 50
microM cadmium chloride. 7. Thus, differences in the electrophysiological
properties between type I, putative magnocellular neurones and type II, putative
parvocellular neurones of the PVN can be attributed to the differential
expression of voltage-gated K+ and Ca2+ currents. This diversity of ion channel
expression is likely to have profound effects on the response properties of these
neurosecretory and non-neurosecretory neurones.
PMID- 10673556
TI - Responses of neurones of the rat suprachiasmatic nucleus to retinal illumination
under photopic and scotopic conditions.
AB - 1. We have examined the responses of neurones in the suprachiasmatic nuclei (SCN)
of the rat to retinal illumination under photopic and scotopic conditions to
identify the types of photoreceptor input to these nuclei. 2. The majority of
visually responsive SCN neurones studied under dark adaptation received rod input
(48 of 52, 92 %). The action spectrum conformed to the sensitivity of rhodopsin,
with maximal sensitivity at around 505 nm. 3. When also studied under light
adaptation, most visually responsive SCN neurones (20 out of 26, 77 %) responded
to input from cones. The action spectra conformed to the spectrum of green cone
opsin, with a main sensitivity peak at 510 nm and a significant secondary peak in
the near-ultraviolet region of the spectrum. 4. The frequency of spontaneous
activity was typically low under scotopic conditions (range 0.2-17.2 Hz) and
higher under photopic conditions (range 0.6-40 Hz) for any given neurone. The
most common response under scotopic conditions was an 'on-excitation' (32 of 48,
62.5 %), which changed under photopic conditions to an on-excitation followed by
a more prominent off-inhibition. 5. Responses also changed due to endogenous
ultradian cycles. Depending on the phase, responses could be altogether absent
and even reverted from excitation to inhibition on opposite phases of a cycle.
Ultradian cycles had a circadian dependence and were most common at around the
light phase:dark phase (L:D) and D:L transition points of the circadian cycle. 6.
Under photopic conditions, SCN neurones showed rhythmic electrical activity, with
a preferred firing interval that had a value between 18 and 39 ms. This rhythmic
activity was probably the result of endogenous subthreshold membrane potential
oscillations. 7. In conclusion, light acting either via rod or cone pathways
could have powerful, opposing actions on SCN neurones. These actions were state
dependent. The presence of these neuronal responses suggests a role for rod and
cone photoreceptors in SCN function.
PMID- 10673558
TI - Temporal coupling between neuronal activity and blood flow in rat cerebellar
cortex as indicated by field potential analysis.
AB - 1. Laser-Doppler flowmetry and extracellular recordings of field potentials were
used to examine the temporal coupling between neuronal activity and increases in
cerebellar blood flow (CeBF). 2. Climbing fibre-evoked increases in CeBF were
dependent on stimulus duration, indicating that increases in CeBF reflected a
time integral in neuronal activity. The simplest way to represent neuronal
activity over time was to obtain a running summation of evoked field potential
amplitudes (runSigmaFP). RunSigmaFP was calculated for each stimulus protocol and
compared with the time course of the CeBF responses to demonstrate coupling
between nerve cell activity and CeBF. 3. In the climbing fibre system, the
amplitude and time course of CeBF were in agreement with the calculated
postsynaptic runSigmaFP (2-20 Hz for 60 s). This suggested coupling between CeBF
and neuronal activity in this excitatory, monosynaptic, afferent-input system
under these conditions. There was no correlation between runSigmaFP and CeBF
during prolonged stimulation. 4. Parallel fibre-evoked increases in CeBF
correlated with runSigmaFP of pre- and postsynaptic potentials (2-15 Hz for 60
s). At higher stimulation frequencies and during longer-lasting stimulation the
time course and amplitudes of CeBF responses correlated with runSigmaFP of
presynaptic, but not postsynaptic potentials. This suggested a more complex
relationship in this mixed inhibitory-excitatory, disynaptic, afferent-input
system. 5. This study has demonstrated temporal coupling between neuronal
activity and CeBF in the monosynaptic, excitatory climbing-fibre system. In the
mixed mono- and disynaptic parallel fibre system, temporal coupling was most
clearly observed at low stimulation frequencies. We propose that appropriate
modelling of electrophysiological data is needed to document functional coupling
of neuronal activity and blood flow.
PMID- 10673557
TI - Chronic passive cigarette smoke exposure augments bronchopulmonary C-fibre inputs
to nucleus tractus solitarii neurones and reflex output in young guinea-pigs.
AB - 1. Children chronically exposed to environmental tobacco smoke (passive cigarette
smoke) have more wheeze, cough, bronchoconstriction, airway hyper-reactivity and
mucous secretion, which may result, in part, from stimulation of the vagal
bronchopulmonary C-fibre reflex. 2. Environmental tobacco smoke increases the
sensitivity of bronchopulmonary C-fibre endings, but the physiological relevance
of this sensitization is unknown. If this exposure augments the reflex responses
via a central mechanism, then the responses of higher-order neurones in the
reflex pathway and some components of the reflex output should also be augmented.
3. Guinea-pigs were chronically exposed to sidestream tobacco smoke (surrogate
for environmental tobacco smoke) or filtered air for 5 days week-1 from age 1 to
6 weeks (age equivalent of human childhood) and were then anaesthetized,
paralysed, ventilated and prepared with pneumothoraces. Baseline and left atrial
capsaicin (0.5 and 2.0 microg kg-1)- evoked changes in the impulse activity of
vagal C-fibre-activated neurones in nucleus tractus solitarii (NTS), phrenic
nerve activity, tracheal pressure, arterial blood pressure and heart rate were
compared in the two groups. 4. Sidestream smoke exposure significantly augmented
the peak (P = 0.02) and duration (P = 0.01) of the NTS neuronal responses and the
prolongation of expiratory time (P = 0.003) at the higher capsaicin dose. 5.
Thus, the sensitization of the bronchopulmonary C-fibre endings by chronic
exposure to sidestream tobacco smoke is transmitted to the NTS and is associated
with a prolonged reflexively evoked expiratory apnoea. The findings may help to
explain some related respiratory symptoms in children and be a factor in sudden
infant death syndrome.
PMID- 10673559
TI - Recycling and refilling of transmitter quanta at the frog neuromuscular junction.
AB - 1. Fluorescent dyes have been used at the frog neuromuscular junction to label
synaptic vesicular membrane. Retrieved membrane is reformed into vesicles, which
are released along with pre-existing vesicles. Consequently, if vesicular
refilling with acetylcholine (ACh) is depressed by inhibitors, two sizes of
quanta should be released: normal and smaller. As recycling continues the
fraction of smaller size quanta should increase exponentially. 2. We enhanced the
rate of quantal release by elevating the K+ concentration. The principal
inhibitors were (-)-vesamicol (VES), hemicholinium-3 (HC3), and NH4+. Quantal
size measurements were fitted to one and to two cumulative lognormal probability
distribution functions. When two fitted better, the statistical significance
assessment took into account the three additional parameters used in calculating
the fit. 3. After recycling in the presence of inhibitor, many sets were fitted
better by two lognormal functions. As recycling continued, the fraction of the
miniature endplate potential voltage-time integrals ( MEPPs) in the larger sub
population decreased exponentially. 4. The size of the releasable pool was
estimated by counting the quanta released by carbonyl cyanide m
chlorophenylhydrazone (CCCP). This was compared to pool sizes calculated from the
inhibitor experiments. The two estimates of pool size were indistinguishable,
with mean values ranging from about 170,000 to 270,000. 5. With all of the
treatments tested, the means of the sizes in the smaller sub-population of MEPPs
were about 1/3 those of the larger sub-populations. 6. Recycling synaptic
vesicles appear to be incorporated into the releasable pool from which they have
roughly the same probability of release as the pre-existing vesicles.
PMID- 10673560
TI - Cerebral correlates of autonomic cardiovascular arousal: a functional
neuroimaging investigation in humans.
AB - 1. States of peripheral autonomic arousal accompany emotional behaviour, physical
exercise and cognitive effort, and their central representation may influence
decision making and the regulation of social and emotional behaviours. However,
the cerebral functional neuroanatomy representing and mediating peripheral
autonomic responses in humans is poorly understood. 2. Six healthy volunteer
subjects underwent H215O positron emission tomography (PET) scanning while
performing isometric exercise and mental arithmetic stressor tasks, and during
corresponding control tasks. Mean arterial blood pressure (MAP) and heart rate
(HR) were monitored during scanning. 3. Data were analysed using statistical
parametric mapping (SPM99). Conjunction analyses were used to determine
significant changes in regional cerebral blood flow (rCBF) during states of
cardiovascular arousal common to both exercise and mental stressor tasks. 4.
Exercise and mental stressor tasks, relative to their control tasks, were
associated with significantly (P < 0.001) increased MAP and HR. Significant
common activations (increased rCBF) were observed in cerebellar vermis, brainstem
and right anterior cingulate. In both exercise and mental stress tasks, increased
rCBF in cerebellar vermis, right anterior cingulate and right insula covaried
with MAP; rCBF in pons, cerebellum and right insula covaried with HR.
Cardiovascular arousal in both categorical and covariance analyses was associated
with decreased rCBF in prefrontal and medial temporal regions. 5. Neural
responses in discrete brain regions accompany peripheral cardiovascular arousal.
We provide evidence for the involvement of areas previously implicated in
cognitive and emotional behaviours in the representation of peripheral autonomic
states, consistent with a functional organization that produces integrated
cardiovascular response patterns in the service of volitional and emotional
behaviours.
PMID- 10673561
TI - Increased muscle spindle sensitivity to movement during reinforcement manoeuvres
in relaxed human subjects.
AB - 1. The effects of reinforcement manoeuvres, such as mental computation and the
Jendrassik manoeuvre, on muscle spindle sensitivity to passively imposed
sinusoidal stretching (1.5 deg, 2 Hz) in relaxed subjects were analysed. 2. The
unitary activity of 26 muscle spindle afferents (23 Ia, 3 II) originating from
ankle muscles was recorded using the microneurographic method. Particular care
was paid to the subjects' state of physical and mental relaxation. 3. The results
showed that the activity of 54 % of the Ia afferents was modified during mental
computation. The modifications took the form of either an increase in the number
of spikes (mean, 26 % among 11 Ia fibres) or a shortening in the latency of the
response to sinusoidal stretching (mean, 13 ms among 3 Ia fibres), or both. They
were sometimes accompanied by an enhanced variability in the instantaneous
discharge frequency. The three secondary endings tested exhibited no change in
their sensitivity to stretch during mental computation. 4. The increased
sensitivity to passive movements sometimes began as soon as the instructions were
given to the subjects and sometimes increased during mental computation. In
addition, the increased sensitivity either stopped after the subjects gave the
right answer or continued for several minutes. 5. During the performance of a
Jendrassik manoeuvre, the Ia units underwent changes similar to those described
above for mental computation. 6. It was concluded that muscle spindle sensitivity
to movement can be modified in relaxed human subjects. The results reinforce the
idea that the fusimotor system plays a role in arousal and expectancy, and
contribute to narrowing the gap between human and behaving animal data.
PMID- 10673562
TI - Care of the child or adolescent with type 1 diabetes.
AB - Type 1 diabetes in children and adolescents is a complex disease requiring
multifaceted care. Children are managed with a combination of insulin by
injection or pump, meal planning, and blood glucose self-monitoring. Close follow
up by a pediatric diabetes treatment team is recommended for most children.
Concerns related to short- and long-term complications and the complexity of day
to-day management comprise the difficulties reported by parents and their
children with type 1 diabetes.
PMID- 10673564
TI - Management of nocturnal enuresis.
AB - Heath care providers can assist the children and families who struggle with the
problem of nocturnal enuresis in various ways. The children and their families
need to receive adequate and appropriate information to assist with the
psychosocial, emotional, and developmental issues involved. They also need to
receive an adequate physical evaluation to diagnose or rule out diseases or
conditions that can cause bedwetting. By taking on these tasks, advanced practice
nurses can thoroughly and safely manage the care of the large population of
children with nocturnal enuresis.
PMID- 10673563
TI - Gastroesophageal reflux in children: a guide for the advanced practice nurse.
AB - Gastroesophageal reflux (GER) is one of the most common gastrointestinal problems
in infants and children. Unfortunately, the diagnosis of GER is often made after
development of serious complications, placing the child at medical and
developmental risk. Early recognition by primary care providers is essential in
preventing these serious, sometimes life-threatening complications of untreated
GER. This article reviews the pathophysiology, clinical manifestations,
diagnostics, and treatment modalities of GER along with developmental
considerations. As a health care provider, the advanced practice nurse is in an
ideal position to provide a complete assessment, develop a realistic plan of
care, coordinate interventions, assess outcomes, and offer support to the family
of the child with GER.
PMID- 10673565
TI - Identifying common pediatric neurosurgical conditions in the primary care
setting.
AB - The primary care setting is crucial to the diagnosis and treatment of pediatric
neurosurgical conditions. The scope of this article is to present common
pediatric neurosurgical diagnoses and their typical presentation to assist the
primary care advanced practice nurse in making timely and appropriate referrals.
The complications from delayed treatment can be significant for the child's
future development. Conditions that are addressed include cutaneous stigmata
related to occult spinal cord defects, common birth-related trauma,
craniosynostosis, positional molding, torticollis, hydrocephalus, mild head
injury, and brain tumors.
PMID- 10673566
TI - The judicious use of antibiotic agents in common childhood respiratory illness.
AB - Increased bacterial resistance is caused most frequently by the widespread use of
antimicrobial agents. Antimicrobial agents are often used inappropriately to
treat common respiratory illnesses in children. This article discusses the
judicious use of antimicrobials in the common cold, otitis media, acute
sinusitis, pharyngitis, and bronchitis.
PMID- 10673567
TI - Practical primary pediatric orthopedics.
AB - Pediatric orthopedic problems often puzzle the primary health provider and worry
families. A thorough orthopedic history and examination by the primary care
provider is all that is necessary to determine whether a problem requires further
evaluation and referral. This article addresses a practical approach to common
orthopedic problems, assessment, and management strategies from the specialist
perspective. A general description of developmental dysplasia of the hip, foot
misalignments, tibial torsion, toe-walking, genu varum (bowlegs), growing pains,
sprains and fractures, and the child with a limp is provided. Management
strategies before and after orthopedic referral are presented.
PMID- 10673568
TI - Advanced practice nursing for children with HIV infection.
AB - Children from any ethnic background and in any geographical location can be
affected by HIV disease. Once acquired, HIV disease holds a devastating future
for the infected child, his or her parents, and the entire family. As a
multisystem disease, HIV affects every aspect of the child's growth and
development. Management and prevention presents many challenges to the pediatric
advanced practice nurse in the ambulatory care setting. This article reviews the
epidemiology and transmission of HIV, as well as the clinical presentation of the
HIV-infected child in the clinic.
PMID- 10673569
TI - Advanced practice nursing in pediatric nephrology.
AB - This article provides the nurse practitioner with a concise and accurate
reference for the evaluation of children with hematuria, proteinuria, and
hypertension. Although the incidence of these disorders in children is lower than
in adults, they are not uncommon. The nurse practitioner must be able to
accurately assess the results of a urinalysis and measure and interpret blood
pressure readings in children. A discussion of when to refer children with signs
and symptoms of serious disease; and how to educate patients and families in
order to promote children's health is also provided.
PMID- 10673570
TI - Pediatric febrile seizures and childhood headaches in primary care.
AB - Febrile seizures and migraine headaches in children are two of the most common
neurological diagnoses seen by primary care practitioners. It is essential that a
knowledge base be developed to better care for this population. This article
reviews pediatric febrile seizures, including management and treatment
recommendations and childhood headaches, with an emphasis on migraine headaches.
Diagnosis, management, and referral criteria are also reviewed.
PMID- 10673571
TI - Pediatric dermatology: that itchy scaly rash.
AB - Primary care practitioners in the pediatric setting treat children for numerous
skin complaints. The most frequently seen dermatologic conditions are those that
are persistent and cause children discomfort, such as atopic, contact seborrheic
dermatitis and tinea infections. Familiarity with the presentation,
pathophysiology, and treatment of these common skin conditions enables the
practitioner to successfully manage these rashes.
PMID- 10673572
TI - The role of the advanced practice nurse in pediatric general surgery.
AB - The advanced practice nurse (APN) functions in pediatric surgery in a variety of
ways. In the inpatient setting, the APN can provide care to infants and children
with many complex congenital and other surgical anomalies. In the outpatient
office, the role includes diagnosis, management, education, and care coordination
for children with both routine and complex diagnoses. This article discusses the
differences in some of these roles and a few of the common diagnoses seen by the
APN in a pediatric surgical practice on a routine day.
PMID- 10673573
TI - Immune mechanisms in rheumatic disease.
AB - The pathophysiology of rheumatic diseases is complex and lacks clear-cut origins.
This article describes the current theories and supporting evidence for the
pathogenesis, mechanisms, and progression of rheumatic diseases. The roles of
genetic inheritance and inflammatory/immune mediators are emphasized.
PMID- 10673574
TI - Issues in the nursing management of osteoporosis.
AB - As new interventions are developed to improve the care of patients with
osteoporosis, nurses will play an important role in improving patients' quality
of life, reducing their fear, and assisting in maintaining their independence
throughout the adult life span. This article examines key issues involved in the
management of patients at risk for, or diagnosed with, osteoporosis.
PMID- 10673575
TI - Osteoarthritis: manageable scourge of aging.
AB - Osteoarthritis is one of the most prevalent diseases of aging. An overview of
osteoarthritis including definition, joints affected, clinical course, and
classification is provided. Contributing factors, such as age, sex, ethnicity,
obesity, diet, estrogen, and activity are discussed. Nursing interventions
encompass weight control, adequate nutrition, evaluation of hormone replacement
therapy, exercise and muscle strengthening, the use of assistive devices,
medication assessment, pain control, psychosocial support, and the use of
alternative therapies. Osteoarthritis can be successfully managed with the use of
multifocal modalities.
PMID- 10673576
TI - The role of exercise in the prevention and treatment of osteoporosis and
osteoarthritis.
AB - Osteoporosis and osteoarthritis are two distinctly different rheumatic conditions
that target elderly, primarily female, populations. This article examines the
scientific evidence supporting the use of exercise as a specific therapeutic
modality, the general physiologic and psychological benefits of exercise, and the
exercise programs currently recommended to combat these prevalent musculoskeletal
disorders. Exercise is a valuable adjunct to treatment programs aimed at
alleviating the risks and symptoms of osteoporosis and osteoarthritis. In
addition to its potential impact on the disease processes themselves, exercise
improves general health and well being, enhances quality of life, and preserves
physical independence.
PMID- 10673577
TI - Nonsteroidal anti-inflammatory drugs: new perspectives on a familiar drug class.
AB - Nonsteroidal anti-inflammatory drugs are among the most commonly used and lethal
drug classes. The anti-inflammatory, analgesic, and antipyretic effects result
from the inhibition of cyclooxygenase (COX), which is the critical enzyme in the
synthesis of prostaglandins. The most common adverse effects are
gastrointestinal, but renal and platelet effects are also important. Recent
discovery that there are two forms of cyclooxygenase (COX-1 and COX-2) has led to
hypothesis that the newly marketed COX-2 selective inhibitor can provide
beneficial effects without these adverse effects. Patient monitoring and
education are nursing functions essential to the safe use of these agents.
PMID- 10673578
TI - Polymyalgia rheumatica and temporal arteritis: a case presentation.
AB - Polymyalgia rheumatica (PMA) and temporal arteritis (TA) are common clinical
syndromes that affect the elderly population. Both syndromes may include similar
constitutional complaints, an increase in acute phase reactants, a rapid response
to corticosteroids, and the presence of anteritis giant cells upon temporal
artery biopsy. Differential diagnosis is one of exclusion. A case presentation is
included to assist practitioners in recognizing presenting symptoms, identifying
diagnostic testing, and proceeding with appropriate therapy and follow-up.
PMID- 10673579
TI - Systemic lupus erythematosus: a multisystem autoimmune disorder.
AB - Systemic lupus erythematosus (SLE) is a chronic illness that has no known cause.
As an autoimmune, inflammatory disease, it can affect various organs in different
ways. Because of its fluctuating, unpredictable qualities, it requires the
implementation of physiologic and psychosocial interventions that may change
daily. A plan of care unique to each individual with SLE is essential to its
management.
PMID- 10673580
TI - Recognition and management of Sjogren's syndrome: strategies for the advanced
practice nurse.
AB - Sjogren's syndrome is an autoimmune disorder characterized by lymphocytic
infiltration of salivary and lacrimal glands. The systemic production of
autoantibodies leads to dry eyes, dry mouth, and other symptoms related to
decreased salivary and lacrimal gland function in patients with Sjogren's
syndrome. This article discusses origins, epidemiology, contributing factors,
symptoms, assessment, diagnostic studies, management, expected outcomes, and
research concerning Sjogren's syndrome.
PMID- 10673581
TI - The psychosocial aspects of osteoporosis in women.
AB - Osteoporosis has been documented to be a physiologically and psychologically
debilitating disease. Health perceptions can be improved through both
psychosocial support and specific intervention programs. These programs can
improve independence and the quality of life of many people afflicted with this
disease.
PMID- 10673582
TI - Laboratory aspects of rheumatologic disease.
AB - Assessment of laboratory values is an important function of nursing practice.
Rheumatologic laboratory assessment, in particular, can be complex because few
findings are actually pathognomonic. This article provides a perspective on an
interpretive approach to laboratory assessment of rheumatologic disease. In
conjunction with the patient's clinical status, these values can provide helpful
information for monitoring or predicting the course of disease.
PMID- 10673583
TI - [Biometrics and epidemiology].
PMID- 10673584
TI - Analysis of incomplete public health data.
AB - The problem of dealing with missing values is common throughout statistics and is
very prominent with epidemiologic data in the broad sense. Not only do data
collection procedures break down, but subjects may be lost to follow up, or
simply withdraw their consent without further providing a reason for doing so. In
this paper, we review a framework for handling incomplete studies, and then
concentrate on a specific case. It comes from a complex health interview survey,
conducted in Belgium in 1997, where different types of missingness arise at
various levels of the hierarchical sampling procedure.
PMID- 10673585
TI - [Dealing with missing, abnormal and incoherent data in E3N cohort study].
AB - BACKGROUND: The E3N Study, 'Etude Epidemiologique aupres de femmes de la Mutuelle
Generale de l'Education Nationale', is a cohort study, aiming at studying cancer
risk factors on 100,000 women. Even if the incidence of problematic (missing,
incoherent, etc.) data is low, any multivariate analysis which would be based
only on complete subjects would rely on a too small sample, which would not
necessarily be representative of the studied population. Results could thus be
biased. METHODS: Our dealing with problematic data includes RESULTS: We looked at
the number of individuals on which an analysis on 19 variables could be
undertaken. The management of missing data made exploitable one fourth of the
cohort, i.e.74.6% of individuals instead of 50.5%. Moreover, for 89.0% of
subjects, one variable at most (out of the 19 studied) has missing datum.
CONCLUSIONS: The main difficulty does not stand so much in the choice and
implementation of methods to deal with problematic data than in the
identification of their process of existence. Most of what was gained was due to
the simplest methods: cold-deck and deductive method.
PMID- 10673586
TI - [Analysis of longitudinal Gaussian data with missing data on the response
variable].
AB - BACKGROUND: Using an application and a simulation study we show the bias induced
by missing data in the outcome in longitudinal studies and discuss suitable
statistical methods according to the type of missing responses when the variable
under study is gaussian. METHOD: The model used for the analysis of gaussian
longitudinal data is the mixed effects linear model. When the probability of
response does not depend on the missing values of the outcome and on the
parameters of the linear model, missing data are ignorable, and parameters of the
mixed effects linear model may be estimated by the maximum likelihood method with
classical softwares. When the missing data are non ignorable, several methods
have been proposed. We describe the method proposed by Diggle and Kenward (1994)
(DK method) for which a software is available. This model consists in the
combination of a linear mixed effects model for the outcome variable and a
logistic model for the probability of response which depends on the outcome
variable. RESULTS: A simulation study shows the efficacy of this method and its
limits when the data are not normal. In this case, estimators obtained by the DK
approach may be more biased than estimators obtained under the hypothesis of
ignorable missing data even if the data are non ignorable. Data of the Paquid
cohort about the evolution of the scores to a neuropsychological test among
elderly subjects show the bias of a naive analysis using all available data.
Although missing responses are not ignorable in this study, estimates of the
linear mixed effects model are not very different using the DK approach and the
hypothesis of ignorable missing data. CONCLUSION: Statistical methods for
longitudinal data including non ignorable missing responses are sensitive to
hypotheses difficult to verify. Thus, it will be better in practical applications
to perform an analysis under the hypothesis of ignorable missing responses and
compare the results obtained with several approaches for non ignorable missing
data. However, such a strategy requires development of new softwares.
PMID- 10673587
TI - [Modeling correlated data in epidemiology: mixed or marginal model?].
AB - Correlated observations (within centers, families, subjects,.) are common in
epidemiology. Even when one is only interested in the modeling of means according
to risk factors, it is also necessary to model the variance-covariance matrix of
the observations in order to make correct inferences on the parameters of
interest. All the more so when the aim of the survey is the measurement of these
correlations or of the variance of the random effects from which they are assumed
to originate. We discuss, within the framework of the linear and of the logistic
models, the implications of two choices for the modeling of covariances. The
mixed model shows the unobserved elements responsible for the similarity between
certain observations. In a longitudinal survey, for instance, one can use a
random effect, specific to each subject, expressing how much a subject's
trajectory is translated as compared to what is expected according to its
characteristics (age, sex,.). The marginal approach leads to modeling separately
the means and the covariance matrix of the observations. The distinction between
these two approaches is important for non linear models, in particular the
logistic one. We insist on the interconnection between a mixed model formulation
and a marginal one, as well as on the implication of the choice in terms of the
parameters' interpretation.
PMID- 10673588
TI - [Methodology for analyzing censored correlated data: application of marginal and
frailty approaches in human genetics. The European Community Alport Syndrome
Concerted Action Group (ECASCA)].
AB - BACKGROUND: Statistical analysis for correlated censored data allows to study
censored events in clustered structure designs. Considering a possible
correlation among failure times of the same group, standard methodology is no
longer applicable. We investigated proposed models in this context to study
familial data about a genetic disease, Alport syndrome. Alport syndrome is a
severe hereditary disease due to abnormal collagenous chains. Renal failure is
the main symptom of the disease. It progresses toward end-stage renal failure
(IRT) according to a high time variability. As shown by genetic studies,
mutations of COL4A5 gene are involved in the X-linked Alport Syndrome. Due to the
large range of the mutation types, the aim of this study was to search for a
possible genetic origin of the heterogeneity of the disease severity. METHODS:
Marginal survival models and mixed effects survival models (so-called frailty
models) were proposed to take into account the possible non independence of the
observations. In this study, time until end-stage renal failure is a rightly
censored end point. Possible intra-familial correlations due to shared
environmental and/or genetic factors could induce dependence among familial
failure times. In this paper, we fit marginal and frailty proportional hazards
models to evaluate the effect of mutation type on the risk of IRT and an
interfamilial heterogeneity of failure times. RESULTS: In this study, the use of
these models allows to show the presence of an interfamilial heterogeneity of the
failure times to IRT. Moreover, the results suggest that some mutation types are
linked to a higher risk of fast evolution to IRT, which explains partially the
interfamilial heterogeneity of the failure times. CONCLUSIONS: This paper shows
the interest of marginal and frailty models to evaluate the heterogeneity of
censored responses and to study relationships between a censored criterion and
covariables. This study puts forward the importance of characterizing the
mutation at a molecular level to understand the relationship between genotype and
phenotype.
PMID- 10673589
TI - [Analysis of a multicenter clinical trial on pressure ulcer development by a
marginal approach in the Cox model].
AB - BACKGROUND: We exemplify the use of a marginal approach with proportional hazards
model when failure times are correlated. METHODS: The marginal distribution for
each failure time is formulated by the Cox proportional hazards model, while the
dependence structure is unspecified. However, a correct variance-covariance
estimate of the regression coefficients that takes into account the intra-group
correlation is proposed. The program MULCOX2 which implements this statistical
methodology is used to assess the effect of a nutritional supplementation
intervention on pressure ulcer development on critically ill older patients from
a multicentric trial (involving 19 wards). We compare the results obtained with
those of the usual Cox regression. RESULTS: The naive approach yields much
smaller standard error estimates of the regression parameters than the robust
approach. CONCLUSION: In our example, the results obtained with the marginal
approach do not modify the conclusions: a nutritional supplementation
intervention tends to decrease significantly the formation of pressure ulcers.
However in other situations, ignoring the intra-cluster dependence could lead to
invalid statistical inference. The variability of the estimated effects by
MULCOX2 can be quite sensitive to the number of clusters in the sample and to the
clusters size.
PMID- 10673590
TI - [Value of multinomial model in epidemiology: application to the comparison of
risk factors for severely and moderately preterm births].
AB - BACKGROUND: The multinomial logistic regression model is employed to model the
relationship between an outcome variable with more than two categories and a set
of covariates. This model is not widely used in epidemiology. We discuss the
value of the multinomial model by comparing it with the binary logistic model,
and we present a statistical comparison of odds ratios (OR) using the multinomial
model. We studied the associations between obstetric history and very (< 33 weeks
of amenorrhea) and moderate (33-36 weeks) preterm births. METHODS: Parameters
(lnOR) of very and moderate preterm births, associated with the severity of
obstetric history (none=0, moderate=1, severe=2), were estimated using two
logistic binary models (moderate preterm births vs full-term births (>=37 weeks),
and very preterm births vs full-term births) and one logistic multinomial model
which compared very and moderate preterm births to full-term births. These
analyses were performed before and after adjustment for a covariate: the country
of survey. Parameters of very preterm birth and moderate preterm birth, estimated
from multinomial model, were compared using Wald test. These analyses were
performed using data from a large case-control survey in Europe, the EUROPOP
survey; 1 675 very preterm births, 3 652 moderate preterm births and 7 965 full
term births were included. RESULTS: Crude parameters of very and moderate preterm
births were similar, regardless the logistic regression model, binary or
multinomial. The estimated parameters slightly differ after adjustment for the
covariate, but lower variance estimates were obtained using multinomial logistic
regression model. Parameters of very preterm birth associated with moderate
obstetric history, B(gp)=0.5040, and severe obstetric history, B(gp)'=1.545,
differ significantly from those of moderate preterm birth, B(pm)=0.4434 and
B(pm)'=1.223 respectively (p < 0.001). CONCLUSION: Parameters obtained in
separate logistic binary models are close to those obtained in a multinomial
model. The multinomial model is useful for testing the heterogeneity of risk
factors for distinct health problems.
PMID- 10673591
TI - [Internal statistical validation of a quality of life questionnaire].
AB - In this paper we present two different statistical approaches to evaluate the
psychometric properties of a quality of life questionnaire. First the study of
the factorial structure is briefly exposed. Then we present the unidimensional
classical models. They are based on the linear relationship between the observed
score and the true score. The definition of the reliability was first addressed
in this classical framework. Its estimation with the Cronbach alpha coefficient
is one important feature of the evaluation of an instrument. More recently,
modern response theory gives a better statistical framework to deal with
unidimensional latent traits. These models describe the probability of positive
answer to an item as a function of the actual value of the latent trait and an
item parameter. We expose the principles of the Rasch model: hypothesis,
estimations methods and fit tests. Finally practical applications to the
validation process of a questionnaire are explored with data from a study of a
short French version of the SIP questionnaire.
PMID- 10673592
TI - [Use of GEE for modeling censored correlated data: application to the study of
risk factors for withdrawal of totally implantable vascular access devices in
cystic fibrosis].
AB - BACKGROUND: The proportional hazards model proposed by Cox for modeling censored
data is not suited for correlated delays, for instance when several events can be
observed on each subject. METHODS: To analyze correlated delays, we propose to
use a log-linear marginal model equivalent to Cox model. Correlations are taken
into account through the use of Liang and Zeger's Generalized Estimating
Equations (GEE) and of their robust variance estimator. An advantage of this
method is that it can be implemented through the SAS GENMOD procedure. When ties
are observed, we propose to use multiple imputations, creating M data sets
without ties from the original one. RESULTS: This method is applied to a
retrospective survey on the risk of withdrawing totally implantable vascular
access devices (TIVAD) because of complication in cystic fibrosis patients: 265
TIVAD implanted in 200 patients were observed. Risk factors were characteristics
of the device or of the patient. Results obtained with the robust variance
estimator and ten imputations show that the use of the device for taking blood
(vs exclusive perfusion of antibiotics), polyurethane catheter (vs. silicon), use
of counterpressure for upkeeping and pulmonary colonization by Pseudomonas
Aeruginosa are significantly associated to withdrawal. Under the Cox model which
does not account for the correlations, some conclusions differ because the robust
variance of the estimators is smaller than the variance obtained under the
working assumption of independent delays. CONCLUSION: This approach allows the
modeling of correlated survival data with SAS software. Our results illustrate
the necessity of accounting for existing correlations.
PMID- 10673593
TI - [Logistic regression vs other generalized linear models to estimate prevalence
rate ratios].
AB - In cross-sectional studies, to quantify the association between a risk factor and
a disease (possibly adjusted for confounders), in the framework of the
multiplicative model, the more obvious effect measure is a prevalence rate ratio
with an associated confidence interval. The validity of this confidence interval
requires an unbiased estimator and an appropriate estimate of the variance. In
numerous epidemiological studies however, routine use is made of odds ratios and
logistic regression. As the odds ratio per se is difficult to understand,
prevalence odds ratios are often interpreted as prevalence rate ratios. But this
latter approximation is valid only under the rare disease assumption. Moreover,
in the logistic regression model, the variance of the estimates is based on the
assumption of binomial variability, which is not always supported by the data; in
the frequent case of overdispersion, this leads to under-estimation of the type I
error rate. Yet, within the generalized linear model, it is easy to choose a link
function other than the logit. For example, the log link (log-binomial model) is
appropriate to directly estimate adjusted prevalence rate ratios. In case of
overdispersion, it is also possible to achieve a better fit of the model, either
by choosing another distribution in the exponential family or by estimating a
dispersion parameter for the binomial distribution. Thus, there are no valid
reasons for the systematic choice of odds ratio and of the logistic regression
model to estimate prevalence rate ratios, unless the type of study imperatively
requires their use.
PMID- 10673594
TI - [Competitive risks and multi-state models in epidemiology].
AB - An introduction to multi-state models is presented. Survival models can be
considered as simple multi-state models; models with competing risks allow to
consider several mortality causes: they enable estimating cause-specific
mortality rates; however, care must be exerted for the interpretation of survival
functions in such models. The illness-death model is very useful for the study of
chronic diseases. Transition intensities can be estimated using conventional Cox
models when observations are done in continuous time. In that model too, one must
avoid pitfalls when interpreting survival functions.
PMID- 10673595
TI - [Survival analysis example based on an event history model from a clinical trial
in cardiology].
AB - BACKGROUND: The main purpose of this paper is to present a survival analysis
example based on an event history model in a competitive risks framework. Our
example is derived from a clinical trial designed for comparing survival of a
beta-blocker therapy group and a placebo group. METHODS: Competitive risks under
study were non lethal cardiovascular events, permanent treatment withdrawals and
deaths. The event history model was assumed to be semi-Markovian. The Cox
proportional hazards model was used for modeling effects of treatments and
regression variables on the transition rates. RESULTS: After taking into account
all covariables influencing survival, mortality in patients who had one non
lethal cardiovascular event after randomization but remained treated was shown to
be reduced in the beta-blocker therapy group (RR=0.41; CI 95%=[0.17-0.98],
p=0.04). CONCLUSIONS: Our analysis indicates that beta-blocker therapy should not
necessarily be stopped in patients who experience a non lethal cardiovascular
event under treatment. This finding requires confirmation in a separate setting.
PMID- 10673596
TI - [Prognostic factors of recurrence and/or death in colorectal cancer: multistate
modeling].
AB - Analysis of survival of patients with cancer sets particular epidemiological and
statistical problems, especially when one wants to take into account metastasis
or local recurrences. Cox's model does not allow modeling multiple events. Wei et
al. have proposed an extension of Cox's model, by formulating the marginal
distributions of multivariate failure times, which allows testing covariates
effects on different events. We applied these methods to data from the Registry
of Digestive Tumors of Burgundy, France. Prognostic factors of recurrence are
rectal location of tumor and advanced stage at diagnosis. Prognostic factors of
death are male gender, age greater than 75, rectal location and advanced stages.
However, relative risk of recurrence for advanced stages is significantly greater
than relative risk of death (p=4.10(-3)), while tumor location has the same
influence on the two events.
PMID- 10673597
TI - [Using capture-recapture models to estimate transition rates between states in
interval-censored data].
AB - We introduce capture-recapture models, survival models developed in animal
population biology to estimate survival / transition rates between sites within a
population. We then show how to use these models in epidemiology or clinical
research, to estimate survival / transition rates between stages of a disease
(e.g. cancer, AIDS...), when patients enter a longitudinal study with imperfect
follow-up resulting in interval-censoring. This method yields unbiased estimates,
since the compliance (defined here as the probability of visiting the doctor at
the planned date) is modelled jointly. We apply the method to cancer data, and
show that "time" (elapsed since entry of a patient in the study) affects
compliance in these data.
PMID- 10673599
TI - [In Process Citation]
PMID- 10673598
TI - [In Process Citation]
PMID- 10673600
TI - 2000 ! les ABC, volume 58, numero 1
PMID- 10673601
TI - [An update on tools].
PMID- 10673602
TI - [SFBC and European clinical biology. Societe Francaise de Biologie Clinique].
PMID- 10673604
TI - [Representation of SFBC].
PMID- 10673603
TI - [SFBC and Inserm].
PMID- 10673605
TI - [Fifty years of biology with SFBC].
PMID- 10673606
TI - [Assets and liabilities of SFBC].
PMID- 10673607
TI - [Promoting the teaching of clinical biology].
PMID- 10673608
TI - [Biomedicine for the sake of the patient].
PMID- 10673609
TI - [The bright future of biology].
PMID- 10673610
TI - [Concerning national quality control of glycosylated hemoglobin (HBA1C)].
PMID- 10673611
TI - [Some historic milestones of clinical haematology].
AB - Microscopy, cell staining methods and tests for characterization of coagulation
factor deficiencies are the landmarks of hematology at the beginning. Direct
access to bone marrow, automatization, development of in vitro culture systems,
monoclonal antibodies, biochemistry of proteins and nucleic acids were used to
build today conception of the blood. Definitions of stem cells, growth factors,
chromosomal translocations in leukemias and coagulation cascade represent the
various aspects of the complex scientific object that the blood became.
PMID- 10673612
TI - [DNA chips].
AB - DNA chips represent a miniaturization of the classical system of reverse dot
blot. They consist of a small size support made of plastic or glass or silicium
on which probes are synthesized or immobilized. It is thus possible to fix a few
thousand or even a hundred of thousands of probes per cm2. Practically the chips
are hybridized with the nucleic acid to be studied that has been amplified
beforehand by PCR and which is generally labelled by a fluorochrome, either
during amplification or after hybridization. After washing the hybrids are
detected by a system which most of the time consists of a laser and a confocal
microscope interfaced with a computer, but many variations exist. It is thus
possible to analyse at the same time a considerable number of sequences. The
diagnostic applications are only at the prototype stage. Eventually the chips
should allow the identification of any point mutation, or the search for
bacteria, viruses or parasites in a very short period of time without preliminary
cultures. They should also allow many sorts of typing ranging from infectious
agents to HLA. They should become a particularly powerful tool in the search for
new medicines and in the revealing of their toxicity. A considerable potential
market is also the diagnosis of the predisposition to polygenic diseases or to a
particular sensitivity to any chemical substance. In fact the chips are only just
beginning to be used. One of the foreseeable developments should be the
possibility to study nucleic acids without preliminary amplification and we can
hope to eventually have at our disposal very cheap, autonomous integrated
systems. The technology could eventually extend to fields other than molecular
biology such as immunology or biochemistry.
PMID- 10673613
TI - [Troponins: biological and clinical aspects].
AB - The troponin complex is composed of three subunits called troponin I, troponin T
and troponin C. Heart isoforms of troponin I and T are not expressed in skeletal
muscle. They can be assayed in blood samples by immunoassays in order to diagnose
and monitor patients with heart diseases. Troponins released in the blood after
necrosis are mainly found as binary or ternary complexes. The kinetics of their
release are close to that of creatine-kinase MB, but the return to normal is
observed after longer periods of time. The excellent analytical sensibility of
troponin assays allows the detection of minor heart damages. Because of its high
specificity, the heart isoform of troponin I is use to diagnose heart damages in
the presence of damages to other organs such as muscle and kidney. The
resynthesis of troponin T by the skeletal muscle decreases its interest to
diagnose muscle-associated heart diseases. In spite of the present lack of
standardisation of troponin I assays, its detection associated to an other early
myocardial marker, such as myoglobin, allows a rapid and reliable diagnostic of
myocardial infarction. The study of post-translationally modified forms of
troponins and their assays could permit a diagnosis and a more precise follow-up
of patients with cardiac necrosis.
PMID- 10673614
TI - [Procalcitonin, a new marker for bacterial infections].
AB - Procalcitonin (PCT), the precursor protein of the hormone calcitonin, appears to
be an early marker of the presence of severe systemic infection. High serum
concentrations are associated with severe systemic bacterial, parasitic or fungal
infections. In contrast, PCT is generally not induced by severe viral infections
or inflammatory reactions of non-infectious origin. Hence, PCT can be used for
differential diagnosis of bacterial and viral meningitis. PCT may be helpful in
the differentiation between infectious and non-infectious origin of systemic
inflammatory response syndrome (SIRS) and acute respiratory distress syndrome
(ARDS), pancreatitis, cardiogenic shock and acute rejection of organ transplants.
PCT monitoring may be useful in patients with high risk of bacterial infection
(major surgery, trauma, immunocompromised patients). PCT is a very stable
molecule in vitro, and its measurement requires only 20 ml of plasma or serum and
can be done within 2 hours.
PMID- 10673615
TI - [Strategy for serum ferritin measurement in 16 to 45 year old women in health
screening centers].
AB - Even in industrialized countries, the iron-deficiency anemia is frequent in
menstruating women. However, the systematic measurement of serum ferritin is not
justified. In this study, a strategy for ferritin measurement has been determined
from data of centers for health screening, obtained in 6,098 menstruating women.
This strategy is based on biological results (hemoglobin, MCV, RDW, GGT, ALAT)
and on responses to the questions about blood donation, birth country and
contraceptive habits. The measurement of serum ferritin is realized in 64%
menstruating women and 23% have an hypoferritinemia (< 20 mg/l).
PMID- 10673616
TI - [A new technique for measuring 17beta-estradiol using Kryptor (Cis Bio
International): utilization to monitor ovulation stimulation].
AB - We studied the performances of the 17b-estradiol determination with the Kryptor
System (Cis Bio international), in assisted medical procreation cycles. The
detection is based on Trace technology. We compared this method with Estradiol-6
method on ACS-180 (Bayer Diagnostics). The Kryptor method is sensitive, has a
good precision and accuracy. Comparison with ACS-180 showed a good correlation
but results were much higher. Patients under stimulation for assisted procreation
were followed by the two methods. The results were close to those obtained with
ACS-180 but significantly higher. Thus it was necessary to define the levels
which have to be reached before ovulation induction.
PMID- 10673617
TI - [Helicobacter pylori: identification and detection of clarithromycin resistance
by gene amplification].
PMID- 10673618
TI - [Focus on a new assay of fucosylated alpha-fetoprotein and evaluation in the
biological diagnosis of hepatocellular carcinoma in cirrhosis].
PMID- 10673619
TI - [Platelets satellitism with polynuclear neutrophils].
PMID- 10673621
TI - [Investigation of isolated aspartate aminotransferase elevation in a patient
treated with minocycline: characterization of a macro-enzyme].
PMID- 10673620
TI - [Infectious mononucleosis or sleeping sickness?].
PMID- 10673622
TI - [Thrombotic microangiopathy revealing acute monoblastic leukemia (LAM5)].
PMID- 10673623
TI - [Quality assurance: internal quality control and external quality evaluation].
PMID- 10673624
TI - [Rules concerning the transport of diagnostic specimens by road. Working Group of
the SFBC. Quality proceeding of the Quality Control section of the SFBC].
PMID- 10673625
TI - Editorial
PMID- 10673626
TI - [TP53 tumor suppressor gene: 20 years (and ten thousand mutations) later].
PMID- 10673627
TI - [Karyotype, aging, and cancer types: are they linked?].
PMID- 10673628
TI - [Cytogenetics of malignant lymphomas in the year 2000].
PMID- 10673630
TI - [Evolution of cancer markers: from radio-immunology to DNA chips and from
surveillance to forecasting].
PMID- 10673629
TI - [Role of the ATM gene in genetic predisposition to cancer].
PMID- 10673631
TI - [Anatomy and pathologic cytology in cancerology: yesterday, today, and tomorrow].
PMID- 10673632
TI - [Therapeutic update on cancer of the breast].
PMID- 10673633
TI - [High-dose chemotherapy in ovarian adenocarcinoma].
PMID- 10673634
TI - [Update on the medical treatment of urologic tumors].
PMID- 10673635
TI - [Laparoscopic surgery in gynecologic oncology in 2000].
PMID- 10673636
TI - [Pharmacokinetic monitoring].
PMID- 10673637
TI - [Preventing and treating hematologic complications of anticancer chemotherapy:
update on hematopoietic growth factors].
PMID- 10673638
TI - [Cancer immunotherapy: new approaches].
PMID- 10673639
TI - [Antitumor cellular immunotherapy: the breakthrough of dendritic cells].
PMID- 10673640
TI - [Quality of life in cancerology].
PMID- 10673641
TI - Stand there, don't just do something.
PMID- 10673643
TI - Osseointegration or osteointegration?
PMID- 10673644
TI - Can academics do it all?
PMID- 10673645
TI - Destructive midline palatal lesion.
PMID- 10673646
TI - Leukemia.
PMID- 10673647
TI - Hydroxyapatite cement for calvarial reconstruction.
PMID- 10673648
TI - Is the mandibular third molar a risk factor for mandibular angle fracture?
AB - OBJECTIVES: The objective of this study was to evaluate the association of
mandibular angle fractures with the presence and state of the eruption of the
mandibular third molar (M3). METHODS: The medical records and panoramic
radiographs of 615 patients with mandibular fractures were examined. The presence
or absence and degree of impaction of the M3 were assessed for each patient and
related to the occurrence of fracture of the mandibular angle. Data were also
collected for age, sex, mechanism of injury, number, and location of mandibular
fracture. Data were analyzed by a chi-square statistic test and Student t test.
RESULTS: The incidence of mandibular angle fracture was found to be significantly
greater when an unerupted M3 was present (P <.05). Of the 426 patients with an
M3, 127 (29.8%) had angle fractures. Of the 189 patients without an M3, 25
(13.2%) had angle fractures. CONCLUSIONS: The results of this study showed that
the mandibular angle that contains an impacted M3 is more susceptible to fracture
when exposed to an impact than an angle without an M3.
PMID- 10673649
TI - Prospective study of modified condylotomy for treatment of nonreducing disk
displacement.
AB - OBJECTIVE: This study was performed to provide an objective assessment of the
outcome of modified condylotomy for treatment of the painful temporomandibular
joint with nonreducing disk displacement (Wilkes late stage III, IV, V). STUDY
DESIGN: A prospective study of 31 consecutive patients (43 joints) was conducted.
All patients had nonreducing disk displacement verified by means of disk imaging.
Independent evaluations were performed to assess pain, dysfunction, and
progression of disease. The examinations were performed before modified
condylotomy and at intervals up to 1 year after the operation. Eighteen patients
(26 joints) completed the required examinations. Patient-based assessments were
completed for pain and diet on 15 of these 18 patients (23 joints) 3 years after
the operation. RESULTS: Visual analog scale (VAS) scores (mean +/- SE) for pain
improved from 7.4 +/- 0.4 before modified condylotomy to 2.4 +/- 0.5 1 year later
(P <. 001). Joints with degenerative joint disease (Wilkes stage IV, V) had less
satisfactory pain relief compared with stage III joints (3. 6 +/- 0.9 vs 1.1 +/-
0.4, P =.05) and an 11-fold higher risk (P <. 04) for serious residual pain (VAS
score >4). Dietary restrictions improved from a mean VAS score of 5.3 +/- 0.7
before the operation to 7.7 +/- 0.5 1 year later (P =.02). Minor differences
between mean VAS scores at 1 (2.1 +/- 0.5) and 3 (2.1 +/- 0.5) years for pain,
and 1 (7.4 +/- 0.6) and 3 (8.1 +/- 0.6) years for diet, were not significant.
Mean maximal interincisal opening was 36.7 +/- 2.0 mm before the operation, and
this improved to 40.1 +/- 2.0 mm 1 year later (P <.02). Mean contralateral
movement was 8.3 +/- 0.5 mm before the operation and 8.4 +/- 0.6 mm 1 year after
the operation (P >.05). None of the 12 Wilkes late III joints progressed to
Wilkes IV or V, and none of the 14 Wilkes IV, V joints showed evidence of further
bone resorption. The rate for reoperation was 4%. Minor complications occurred in
5 patients and were resolved in all but 1 a year later. When these outcomes were
judged by 7 American Association of Oral and Maxillofacial Surgeons assessment
indices for internal derangement, the mean rate of favorable outcome was 87%.
CONCLUSION: Modified condylotomy is a safe and effective operation for treating
pain and diminished function of temporomandibular joints with nonreducing disk
displacement. It also seems to be an effective treatment for slowing further
progression of the internal derangement and associated pathologic conditions.
PMID- 10673650
TI - Submandibular gland mucocele: diagnosis and management.
AB - Mucoceles originating from the submandibular gland are extremely rare. A review
of the English literature resulted in identification of only 5 such cases. We
have diagnosed and treated 2 submandibular mucoceles. Both lesions were removed
in continuity with the submandibular and sublingual glands. No complications and
no recurrences have occurred to date. The diagnosis of these lesions is
complicated because of the lack of specific clinical diagnostic criteria and the
similarity between submandibular mucoceles and plunging or cervical ranulas.
Computerized tomography and specifically the presence of a so-called "tail" sign
is pathognomonic for plunging ranula. This sign is absent in mucoceles
originating in the submandibular glands. The treatment strategies vary as well. A
diagnostic algorithm and a surgical rationale for treatment of submandibular
mucoceles are presented.
PMID- 10673651
TI - Efficacy of high-density versus semipermeable PTFE membranes in an elderly
experimental model.
AB - OBJECTIVE: The clinical effectiveness of expanded polytetrafluoroethylene (PTFE)
membranes for guided bone regeneration has been reported in the literature on
several occasions. However, one major drawback of this material is the need for a
second surgical operation for removal of the membrane. In addition, most studies
involving guided bone regeneration in animal models have used young animals or
animals of unspecified age, but in some clinical situations guided bone
regeneration may be indicated in elderly jaw bones. The objectives of this
investigation were (1) to evaluate the effectiveness of a newly introduced high
density PTFE membrane (TefGen-FD)-a material that does not require second-stage
surgery for its removal-for enhancement of bone ingrowth in elderly rabbits'
calvaria and (2) to compare the findings with those obtained with the commonly
used semipermeable expanded PTFE membrane (Gore-Tex). STUDY DESIGN: Eighteen
elderly rabbits (each more than 30 months old) served as the experimental animals
in this study. Two non-self-healing, full-thickness defects were created in each
rabbit calvarium. One of the 2 defects was fully covered with macroprous expanded
PTFE membrane (Gore-Tex); the other defect was covered with microporous PTFE
membrane (TefGen-FD). Specimens were obtained at 4, 8, and 16 weeks and examined
by means of light microscopy. RESULTS: Clinically, the high-density TefGen
membrane was much easier to detach from the underlying bone than was the
semipermeable Gore-Tex membrane, which showed strict adherence to bone surface on
removal. Microscopically, the Gore-Tex membrane lamellae were infiltrated by
fibro-osseous tissue at the membrane's lower surface. A relatively greater speed
and quantity of bone regeneration were observed in the defective cavities covered
with Gore-Tex membrane than in those covered with TefGen membrane. CONCLUSIONS:
It appears that the semipermeable Gore-Tex membrane is more effective than the
high-density TefGen-FD membrane with respect to guided bone regeneration in
elderly bone. These findings have relevance for the clinical situation of using
guided bone regeneration in conjunction with implant placement and ridge
augmentation procedures in atrophic elderly jaws.
PMID- 10673652
TI - Oral staphylococcal mucositis: A new clinical entity in orofacial granulomatosis
and Crohn's disease.
AB - OBJECTIVE: Orofacial granulomatosis and the oral manifestations of Crohn's
disease comprise many clinical features, of which stomatitis is one. The purpose
of this study was to establish a role for Staphylococcus aureus in mucositis
affecting some patients with orofacial granulomatosis or oral Crohn's disease.
STUDY DESIGN: Four patients (2 with orofacial granulomatosis and 2 with oral
Crohn's disease), from a total of 450 patients examined over 10 years, had
stomatitis involving the entire oral mucosa, from which S aureus was cultured by
the oral rinse technique. These patients were treated with flucloxacillin or
erythromycin. RESULTS: A heavy growth of S aureus was isolated from the mouth of
each patient. All 4 patients responded to treatment with flucloxacillin or
erythromycin. CONCLUSIONS: S aureus is a potential cause of panstomatitis in
patients with orofacial granulomatosis or Crohn's disease. This infection
responds rapidly to antimicrobial treatment.
PMID- 10673653
TI - Delayed eruption of permanent teeth in hyperimmunoglobulinemia E recurrent
infection syndrome.
AB - OBJECTIVE: To determine the incidence of abnormal tooth eruption in patients with
hyperimmunoglobulinemia E (hyper-IgE) syndrome. STUDY DESIGN: This study
evaluated 34 individuals with hyper-IgE syndrome (age range, 2-40 years). A
comprehensive dental history and a head and neck evaluation were performed on all
patients. Dental age was assessed in patients younger than 17 years by 2 methods:
(1) clinical assessment of tooth eruption and (2) a radiographic method.
Relationships between the chronologic age, dental developmental age, and age at
tooth eruption were determined. Other oral or dental anomalies were recorded.
RESULTS: Of patients older than 7 years, 75% reported problems with permanent
tooth eruption, as evidenced by retained primary teeth or the need for elective
extractions of primary teeth to allow eruption of permanent teeth. None of the
patients experienced problems with eruption of primary teeth. Eruption of the
first and second permanent molars also occurred on time. Dental maturity scores
were established for 14 patients 17 years of age or younger. In each case, the
difference between chronologic age and the estimated dental developmental age was
less than 12 months; however, we found a significant discrepancy between the
chronologic age and the mean age of tooth eruption in 80% of these patients when
using a particular set of standardized values. Persistence of Hertwig's
epithelial root sheath was observed on histologic examination. Chronic multifocal
oral candidiasis was a consistent feature in patients with hyper-IgE recurrent
infection syndrome. Other oral anomalies were also noted. CONCLUSION: We
confirmed that a disorder of tooth eruption is part of the hyper-IgE syndrome.
This problem occurs because of delayed primary tooth exfoliation rather than a
developmental delay in the formation of the permanent dentition. The persistence
of Hertwig's epithelial root sheath is unusual and may be associated with the
lack of resorption of the primary teeth. Dentists should be aware of this feature
of hyper-IgE syndrome because timely intervention will allow normal eruption to
occur.
PMID- 10673654
TI - Past administration of beta-lactam antibiotics and increase in the emergence of
beta-lactamase-producing bacteria in patients with orofacial odontogenic
infections.
AB - OBJECTIVE: The purpose of this study was to determine the current status of beta
lactamase-producing bacteria in orofacial odontogenic infections. STUDY DESIGN:
Microbiologic data regarding purulent exudate from 111 cases with orofacial
odontogenic infections were analyzed in relation to the past administration of
beta-lactams. RESULTS: beta-lactamase-producing bacteria were isolated more
frequently from the beta-lactam-administered group (38.5%) than from the beta
lactam-nonadministered group (10.9%; P <.005), and they were isolated more
frequently as the duration of administration increased. The predominant bacteria
isolated included Prevotella (the most frequent isolate), viridans streptococci,
Peptostreptococcus, and Fusobacterium, and 7.1% of total isolates produced beta
lactamase. Penicillin and cefazolin worked well with beta-lactamase-nonproducing
Prevotella but were remarkably affected by beta-lactamase-producing Prevotella.
Cefmetazole, sulbactam/cefoperazone, and imipenem worked well against both types
of Prevotella. CONCLUSIONS: beta-lactams are still suitable for the first
antimicrobial therapy in the treatment of these infections. However, because past
beta-lactam administration increases the emergence of beta-lactamase-producing
bacteria, beta-lactamase-stable antibiotics should be prescribed to patients with
unresolved infections who have received beta-lactams.
PMID- 10673655
TI - Examination of the oral mucosa and peripheral blood cells of patients with
recurrent aphthous ulceration for human herpesvirus DNA.
AB - OBJECTIVE: The purpose of this study was to exam the oral mucosa and peripheral
blood cells of patients with recurrent aph-thous ulceration (RAU) for the
presence of the following human herpesviruses: herpes simplex viruses 1 and 2,
varicella zoster virus, Epstein-Barr virus, cytomegalovirus, human herpesvirus-6,
and human herpesvirus-7. STUDY DESIGN: Fifty-eight subjects with RAU and 10
control subjects were recruited at an academic referral center and enrolled in
this prospective, nonrandomized, case-controlled study. Each of the subjects with
RAU was seen during an acute episode, and swab specimens from lesional (RAU
acute/lesion) and clinically normal (RAU-acute/normal) oral mucosa were obtained.
Each of 2 subjects with RAU was evaluated during more than one acute episode.
Three subjects with RAU were seen between active episodes, and swab specimens
were taken from clinically normal (RAU-convalescent) oral mucosa. Swab specimens
from clinically normal (control/normal) oral mucosa were obtained from the
control subjects. Peripheral blood specimens were obtained from subjects with RAU
and control subjects at the time the swab specimens were performed. Through use
of polymerase chain reaction, all swab and peripheral blood specimens were
examined for the presence of human herpesvirus DNA. Statistical significance was
determined by means of chi(2) analysis. RESULTS: Herpes simplex virus and human
herpesvirus-6 were found in a higher percentage of mucosal specimens from the
control subjects (herpes simplex virus, 4/10; human herpesvirus-6, 5/9) than from
the subjects with RAU (RAU-acute/lesion: 3/45 herpes simplex virus, 13/53 human
herpesvirus-6; RAU-acute/normal: 7/48 herpes simplex virus, 9/53 human
herpesvirus-6). No difference was demonstrated between RAU-acute/lesion, RAU
acute/normal, and RAU-convalescent mucosal specimens for any of the human
herpesviruses. Different human herpesviruses were identified from individual
subjects with RAU during subsequent episodes of disease. Epstein-Barr virus
(6/35), human herpesvirus-6 (3/40), and human herpesvirus-7 (7/43) were detected
in the peripheral blood mononuclear cells during acute RAU but not in RAU
convalescent or control peripheral blood mononuclear cells. CONCLUSIONS: The
detection of human herpesvirus DNA from the oral mucosa and peripheral blood
mononuclear cells of patients with RAU appears to represent normal viral shedding
rather than a direct causal mechanism in this disorder.
PMID- 10673656
TI - Calcified leiomyoma of the lateral pterygoid muscle in an 8-year-old boy.
AB - Deep soft tissue leiomyomas are extremely rare benign tumors in childhood. An
unusual case of benign calcified leiomyoma of the pterygoid muscle in an 8-year
old boy is presented. Clinical manifestations and radiographic and
histologicpathologic findings, as well as the differential diagnosis and possible
histogenesis of this rare tumor, are discussed.
PMID- 10673657
TI - Plasma cell granuloma of the oral mucosa with angiokeratomatous features: a
possible analogue of cutaneous angioplasmocellular hyperplasia.
AB - We report a plasma cell granuloma arising in the movable mucosa of the oral
cavity of a 50-year-old man. Histologically, the lesion was characterized by a
dense nodular infiltrate of mature plasma cells. Immunostaining for kappa and
lambda light chains confirmed a polyclonal plasma cell population. Elongated rete
ridges of the overlying epithelium formed collarettes around dilated blood and
lymph vessels in focal areas. Based on the overall histologic architecture, we
hypothesize that these peculiar changes are secondary to local blood flow
alteration with congestive vasodilation caused by a dense plasma cell infiltrate.
We believe that the plasma cell population may represent the oral counterpart of
the cutaneous angioplasmocellular hyperplasia.
PMID- 10673658
TI - Oral findings in DiGeorge syndrome: clinical features and histologic study of
primary teeth.
AB - OBJECTIVE: For the purpose of supplementing the shortage of dental information
about DiGeorge syndrome, we report two cases of the syndrome seen in Japanese
boys. STUDY DESIGN: Two cases were compared with respect to orofacial and dental
findings; one was a case of complete DiGeorge syndrome and the other a case of
partial DiGeorge syndrome. Extracted deciduous teeth from the two boys underwent
histologic study. RESULTS: Each patient showed systemic developmental delay,
hypocalcemia, and slight mental retardation. In the orofacial area,
hypertelorism, a short philtrum, thick and reflected lips, and hypoplasia of the
nasopharynx were also observed. A dental examination showed delayed formation and
eruption of permanent teeth, aplasia of the nasopharynx, and enamel hypoplasia
along with enamel hypocalcification. Structural streaks with increased
calcification were histologically detected in the deciduous tooth from the
patient with complete DiGeorge syndrome. CONCLUSIONS: Common characteristic
orofacial and dental findings were noted in the two DiGeorge syndrome cases.
Furthermore, histologic study of the deciduous tooth from the boy with complete
DiGeorge syndrome suggests that there was some relationship between transient
relative hypercalcemia and dentinal hypermineralized streaking of the tooth.
PMID- 10673659
TI - Mercury release from dental amalgam after treatment with 10% carbamide peroxide
in vitro.
AB - OBJECTIVES: The effect of 10% carbamide peroxide on mercury release from dental
amalgams was assessed in vitro by using a cold-vapor atomic absorption Mercury
Analyzer System. STUDY DESIGN: Samples of 4 commercial brands of dental amalgam,
Megaloy (Dentsply/Caulk, Milford, Del), Mega+ (CFPM, Aulnaye, France), Nongama 2
(Silmet, Or Yehuda, Israel), and Valiant Ph.D. (Dentsply/Caulk, Milford, Del),
were treated for 48 hours with 10% carbamide peroxide and compared with samples
treated with phosphate buffer. RESULTS: Amalgam specimens exposed for 48 hours to
10% carbamide peroxide showed significantly higher concentrations of mercury in
solution as compared with specimens treated with phosphate buffer (P <.001).
Megaloy and Valiant Ph.D. yielded significantly higher mercury concentrations in
solution than Mega+ and Nongama 2 (P <.001). Mega+ yielded significantly higher
mercury concentrations in solution than Nongama 2 (P <.05). No significant
differences were found in mercury concentrations in solution between Megaloy and
Valiant Ph.D. CONCLUSIONS: Treatment with 10% carbamide peroxide bleaching agents
caused an increase in mercury release from amalgam restorations, possibly
increasing exposure of patients to its adverse effects. Amalgam brands differed
in the amounts of mercury release after bleaching with carbamide peroxide.
PMID- 10673660
TI - Management of a horizontal root fracture after previous root canal therapy.
AB - This case report concerns a 9-year-old girl who had a horizontal root fracture of
her maxillary left central incisor and had root canal therapy performed by her
family dentist immediately after the injury. Because of the incomplete canal
obturation, the root canal filling material was removed, and calcium hydroxide
therapy was initiated. Healing at the fracture site occurred, with hard tissue
forming between the root segments. The coronal segment of the root was then
obturated with gutta-percha. The patient later had orthodontic treatment with
some movement of the coronal segment. Six-year post-treatment follow-up shows
apparent clinical and radiographic success. This case illustrates the potential
for repair of a horizontal root fracture after endodontic retreatment of the
coronal segment and long-term splinting.
PMID- 10673661
TI - A light and transmission microscopic study of mechanically exposed monkey pulps:
dynamics of fiber elements during early dentin bridge formation.
AB - OBJECTIVE: The aim of this investigation was to assess the role of the von Korff
like fibers (VKF) during the process of dentin bridging. STUDY DESIGN: The monkey
pulps, exposed to a hard-set calcium hydroxide, were evaluated at 3, 7, 14, 21,
30, 90, and 180 days. RESULTS: At 21 days, longitudinal and transverse collagen
fibrils were organized as lamellar structures in close proximity to and subjacent
to the newly formed predentin. VKF bundles were present between newly formed
odontoblastoid cells. The VKF were bundles of thin collagen fibrils inserted into
the predentin, which consisted of thick collagen fibrils. At 30 days, the
exposure site was completely occluded with a new predentin matrix; lamellar
structures and VKF were no longer present. CONCLUSIONS: The VKF may play a role
in the connective tissue attachment to the dentin bridge, early in its formation.
PMID- 10673662
TI - Pulpal tissue in bilateral talon cusps of primary central incisors: report of a
case.
AB - Talon cusp is a tooth anomaly that affects both the primary and the permanent
dentitions. However, the occurrence of this anomalous cusp is rather infrequent
in the primary dentition. Only 7 cases of bilateral talon cusps affecting the
primary teeth have been reported in the dental literature. This is a case report
of bilateral talon cusps on primary maxillary central incisors whose histologic
evaluation revealed the existence of pulpal tissue in the anomalous cusps.
PMID- 10673663
TI - Effective dose from radiation absorbed during a panoramic examination with a new
generation machine.
AB - OBJECTIVES: The purpose of this investigation was to measure the tissue-absorbed
dose and to calculate the whole-body effective dose (E) for a new generation
panoramic machine (Planmeca PM 2002 CC Proline), operating in the panoramic
examination mode. Comparisons could then be made with historical panoramic and
intraoral radiographic dose measurement values and effective dose estimates.
STUDY DESIGN: Thermoluminescent dosimeters were embedded in a humanoid, tissue
equivalent phantom at anatomically significant sites, representing key tissues.
Absorbed dose measurements were obtained after every 5 panoramic exposures of a
25-exposure total. The measured average tissue-absorbed doses from a single
panoramic exposure were used in the calculation of the whole-body E. RESULTS: The
whole-body E for the PM 2002 CC Proline panoramic examination is 3.85 microSv.
This is below the panoramic average of 6.7 microSv. The PM 2002 CC Proline
panoramic examination delivers approximately 5% to 12% of the E of a complete
mouth intraoral radiographic examination. CONCLUSIONS: The effective dose from
the PM 2002 CC Proline examination is at the low end of the range for other
panoramic machines and is far below either a D-speed or E-speed film intraoral
radiographic examination.
PMID- 10673664
TI - Mandibular bone density and fractal dimension in rabbits with induced
osteoporosis.
AB - OBJECTIVE: Our goal in this investigation was to examine the mandibular bone
density and radiographic textural changes and the relationship between mandibular
and spinal bone mineral density in an osteoporotic rabbit model. STUDY DESIGN:
Three adult female New Zealand white rabbits in each of 4 groups received daily
injections of cortisone acetate at a dosage of 0.0 (control), 3.0, 7.5, or 15.0
mg/kg for 4 weeks. The rabbits were then killed, and the mandible and spine of
each animal were removed. Digital radiographs (70 kVp, 10 mA, 8 impulses) of the
hemimandibles and spines were made. Lateral and anteroposterior bone densities of
the lumbar spine (L2) were calculated, and average mandibular interdental bone
density, fractal dimension, and gradient values were calculated. RESULTS:
Correlation analysis revealed that cumulative steroid dose was strongly related
to mandibular bone density (r = -0.80, P <.01), moderately related to mandibular
fractal dimension (r = -0.61, P <. 05), and moderately related to anteroposterior
lumbar spine density (r = -0.64, P <.05). Moderate correlations were found
between mandibular interdental bone density and spinal density (r = 0.56, P
<.05), but mandibular fractal dimension was not related to spinal density.
CONCLUSIONS: In osteoporotic female rabbits, mandibular bone mineral density
decreases in relation to spinal density and cumulative steroid dose. Mandibular
fractal dimension decreases with cumulative steroid dose but is not significantly
related to either mandibular density or spinal density.
PMID- 10673665
TI - Radiographic manifestation of clear cell odontogenic tumor.
AB - Clear cell odontogenic tumors are uncommon, only 20 cases having been reported in
the literature. We report a case that presented with unique radiographic
manifestations over a period of 12 years; no similar case has been reported to
date. Documentation of the malignant nature of the condition and of the range of
clinical and radiographic manifestations with which this neoplasm can present
provides useful insight into its pathogenesis and progression. Early and timely
recognition of the lesion, histopathologic examination, and aggressive
interventional procedures are in order to successfully treat this condition and
prevent a potentially fatal outcome.
PMID- 10673666
TI - Radiographic evidence of enamel pearls in jordanian dental patients.
AB - OBJECTIVE: An "enamel pearl" is an ectopic globule of enamel that is adherent to
the tooth root surface. Such an anomaly may facilitate the progression of
periodontal breakdown. Information on the prevalence of enamel pearls is sparse,
and ethnic variations are thought to occur. Our objective was to assess the
prevalence of enamel pearls in a group of Jordanian dental patients. STUDY
DESIGN: A random sample of 819 dental records were selected, and a total of 1032
periapical radiographs were interpreted for the presence of enamel pearls.
RESULTS: Enamel pearls were detected in 4.76% of the subjects and on 1.6% of the
molars. No significant difference between sexes was observed. First molar teeth
were the most commonly affected, whereas the third molars were the least affected
with the condition. CONCLUSIONS: Enamel pearls are not uncommon among Jordanian
dental patients, and their early detection could be important in prevention of
periodontal disease.
PMID- 10673667
TI - Ganglioneuroma of the mandible: radiologic and pathologic findings of a rare
tumor.
AB - Ganglioneuroma is a rare benign neural tumor, thought to arise from the ganglia
of the sympathetic chain or parasympathetic nervous system. It is therefore most
commonly seen in the abdomen and thorax. The occurrence of ganglioneuroma in the
mandible is exceptional; to date only 5 cases have been reported. We present
another case of ganglioneuroma of the mandible, demonstrate the radiologic and
pathologic findings, and discuss the possible causes of the tumor at this site.
PMID- 10673668
TI - Dose-intense paclitaxel, etoposide and cyclophosphamide: a safe and active
regimen for tumor cytoreduction and stem cell mobilization in metastatic breast
cancer.
AB - Patients with metastatic breast cancer in complete remission are the ones most
likely to have an improved outcome with subsequent high-dose chemotherapy and
autologous peripheral blood stem cell transplantation (HDC-PBSCT). Peripheral
blood stem cells are usually procured following mobilization with single agent
chemotherapy and colony-stimulating factor support. We utilized a dose-intense
regimen of paclitaxel 200 mg/m2 i.v., etoposide 60 mg/kg i.v., and
cyclophosphamide 3 g/m2 i.v. (TEC) followed by daily administration of
granulocyte colony-stimulating factor. The aim was not only to mobilize stem
cells but also to achieve optimal tumor cytoreduction prior to HDC/PBSCT. One
hundred consecutive patients with metastatic breast cancer received 257 cycles of
TEC between March 1994 and June 1997, with the aim of collecting 5 x 106 CD34
positive cells/kg usually following the second cycle of chemotherapy. Patient
characteristics included a median age of 45 years, a median of two organ systems
involved by disease, a median of two prior chemotherapy regimens and eight prior
chemotherapy cycles, and a median interval of 8 months from diagnosis of
metastases to first cycle of TEC. There were 61 febrile episodes during
neutropenia and 13 of these were associated with bacteremia or fungemia.
Mortality rate was 1%. An adequate number of stem cells was collected in 90% of
patients. The overall response rate of the tumor was 58.8% with 23.7% complete
responders among 97 evaluable patients. Multivariate analysis demonstrated
chemosensitivity to the most recent standard chemotherapy regimen administered
for metastatic disease, an ECOG performance score of 0 as opposed to 1, 2 or 3,
and involvement by disease of only one organ system as significant variables for
achieving a complete remission with TEC. This novel dose-intense regimen was safe
and well tolerated, highly active against metastatic breast cancer, and capable
of excellent stem cell mobilization. Bone Marrow Transplantation (2000) 25, 123
130.
PMID- 10673669
TI - Hematopoietic stem cell allografts using a non-myeloablative conditioning regimen
can be safely performed on an outpatient basis: report of four cases.
AB - Using a non-myeloablative, immunosuppressive, fludarabine-based conditioning
regimen, we performed allogeneic peripheral blood stem cell transplants totally
on an outpatient basis in four patients (two with chronic myelogenous leukemia,
one with acute myelogenous leukemia and one with thalassemia major). The median
granulocyte recovery time to 0.5 x 109/l was 10 days and the lowest absolute
neutrophil count was 0.064 x 109/l; only one patient developed thrombocytopenia
below 20 x 109/l. No patient required red blood cell transfusions and one was
given a single prophylactic platelet transfusion. All patients are alive at 210
390 (median 285) days and have definite evidence of chimerism; one developed
biopsy-proven GVHD on day 50, with a limited cutaneous rash. The procedure is
less costly than its counterpart using myeloablative conditioning regimens and
may represent another approach in the management of patients requiring an
allogeneic stem cell transplant. Bone Marrow Transplantation (2000) 25, 131-133.
PMID- 10673670
TI - Evidence of alloreactive T lymphocytes in fetal liver: implications for fetal
hematopoietic stem cell transplantation.
AB - The use of hematopoietic stem cells for in utero transplantation to create
permanent hematochimerism represents a new concept in fetal therapy, although
this approach has provided heterogeneous results. In this paper we have
undertaken molecular, phenotypic and functional studies aimed at identifying the
presence of fully competent T lymphocytes in samples of fetal livers and cord
blood. We found mature VDJ TCR beta chain transcripts in fetal liver cells taken
from 7 to 16 weeks of gestation and a similar pattern was detected in cord blood
cells sampled from 13.5 to 20.5 weeks of gestation. A Vbeta8 gene sequence
comparable to that detected in adult PBMC was found in fetal liver samples at 9
or 17 weeks gestation. PreTalpha message was detected in all samples and its
expression decreased in fetal blood samples with increasing gestational age while
Calpha message appeared at 9.4 weeks and its expression increased during
gestational age. T cell clones obtained from fetal liver cells showed a mature
TCR alphabeta+, CD8+ phenotype and displayed strong alloreactivity against allo
MHC class I molecules. The presence of alloreactive T lymphocytes may explain the
failure to engraft in fetuses older than 13 to 16 weeks and may provide insights
into fetal liver transplantation. Bone Marrow Transplantation (2000) 25, 135-141.
PMID- 10673671
TI - Cytogenetic status pre-transplant as a predictor of outcome post bone marrow
transplantation for chronic myelogenous leukaemia.
AB - We have analysed pre-transplant cytogenetic findings in 418 patients with CML in
pre-blastic phase who underwent allogeneic BMT between February 1981 and January
1998. Five different patient groups were identified: A = Philadelphia (Ph)+; B =
Ph-, BCR-ABL+; C = variant Ph (VPh); D = Ph chromosome plus at least one of:
trisomy 8, +Ph, chromosome 17 abnormalities and E = other abnormalities in
addition to the Ph chromosome. There were two principal conclusions. Firstly, Ph-
patients showed a better outcome, and VPh patients a worse outcome, than those
with a standard Ph, both in terms of leukaemia-free survival (LFS) (76.9%, 22.1%
and 31.9%) and the risk of treatment failure relative to those with a standard Ph
(relative risks of 0.49 and 1.92, respectively). One contributing factor may be
relapse: no Ph- patients relapsed, whereas all other groups showed similar
probabilities of relapse at 5 years (range 33.0-44. 0%). Secondly, those with the
additional changes of +8, +Ph and i(17q) did not show a worse outcome than those
with no additional changes (5 year survival of 44.7% vs 51.8%; 5 year LFS of
40.6% vs 31.9%), whereas those with other additional changes may fare worst of
all (40.4% and 16.0%, respectively). Bone Marrow Transplantation (2000) 25, 143
146.
PMID- 10673672
TI - Incidence and outcome of vancomycin-resistant enterococcal bacteremia following
autologous peripheral blood stem cell transplantation.
AB - A retrospective evaluation of 321 consecutive recipients of high-dose
chemotherapy (HDC) and autologous peripheral blood stem cell transplantation
(PBSCT) was conducted to ascertain the incidence and outcome of vancomycin
resistant enterococcal (VRE) bacteremia. Ten patients developed VRE bacteremia at
a median of 6 days following PBSCT. Nine isolates were Enterococcus faecium and
one was E. faecalis. The median duration of bacteremia was 5 days. The central
venous catheter was removed in seven individuals. Nine patients were treated with
a variety of antimicrobial agents including quinupristin-dalfopristin,
chloramphenicol, doxycycline, oral bacitracin, co-trimoxazole, and
nitrofurantoin. Bacteremia resolved without adverse sequelae in seven patients.
Two individuals who died of other causes had persistent or relapsed bacteremia at
the time of death. An additional patient suffered multiple relapses of VRE
bacteremia and died as a result of VRE endocarditis 605 days following PBSCT.
Mortality as a direct result of VRE bacteremia was 10% in this series. The
optimal type and duration of treatment of VRE bacteremia has not been clearly
defined. Therefore, we perform weekly stool surveillance cultures for VRE in our
hospitalized transplant population and apply strict barrier precautions in those
individuals in whom stool colonization has been identified. Furthermore, the
empiric use of vancomycin has been restricted. Bone Marrow Transplantation (2000)
25, 147-152.
PMID- 10673673
TI - Human herpesvirus 8 (KSHV) contamination of peripheral blood and autograft
products from multiple myeloma patients.
AB - Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated
herpesvirus (KSHV), has recently been identified within the bone marrow dendritic
cells of multiple myeloma (MM) patients. This virus contains homologues to human
cytokines such as IL-6 that could potentially stimulate myeloma cell growth and
contribute to disease pathogenesis. Since mobilization chemotherapy may increase
circulating dendritic cell numbers, we searched for HHV-8 in peripheral blood
mononuclear cells (PBMCs) before and after mobilization chemotherapy given to MM
patients. Furthermore, we determined if autograft purging using the CEPRATE SC
device would reduce the percentage of HHV-8 infected stem cell products. Only two
of the 39 PBMC samples collected prior to mobilization chemotherapy contained PCR
detectable virus, yet nine of 37 PBMCs collected on the first day of
leukapheresis had detectable HHV-8 (P = 0.016). HHV-8 was more frequently
identified in autograft products before vs after Ceprate SC selection (40% vs
15%, P = 0.016). Although the role HHV-8 plays in myeloma pathogenesis remains
unclear, these results imply that mobilization chemotherapy increases the numbers
of circulating HHV-8-infected dendritic cells within the peripheral blood. In
addition, CD34 selection of autograft products in MM patients may reduce the
reintroduction of virally infected cells following high-dose chemotherapy. Bone
Marrow Transplantation (2000) 25, 153-160.
PMID- 10673674
TI - Respiratory syncytial virus immune globulin treatment of lower respiratory tract
infection in pediatric patients undergoing bone marrow transplantation - a
compassionate use experience.
AB - Respiratory syncytial virus (RSV) pneumonia in BMT recipients carries a mortality
rate of approximately 50-70% despite ribavirin (Virazole) treatment. In both
immunocompetent and immunocompromised animal models, RSV neutralizing antibodies
rapidly reduce pulmonary virus load after a single dose. RSV-IGIV (RespiGam) is
an IgG immune globulin with high concentrations of RSV neutralizing antibody (>19
200 MU/ml). From June 1991 to February 1996, a compassionate-use protocol using
RSV-IGIV for treatment of RSV infections was conducted. Eleven children at
multiple centers, mean age 3.3 years (4 months to 9 years), were undergoing BMT
and met the protocol criteria. They received a single 1500 mg/kg dose of RSV-IGIV
infused over 12 h at a median of 5 days (1-37 days) after RSV symptom onset. Ten
of these patients received prior or concurrent aerosolized ribavirin. Serum RSV
neutralizing titers were measured in five patients and showed a 3- to 30-fold
increase 24 h after RSV-IGIV infusion. Adverse events were mild. One of 11 (9.1%)
patients died from their RSV illness (91% RSV survival). In comparison to
previously published reports, RSV-IGIV treatment of RSV pneumonia in BMT patients
may increase survival above that in such patients treated with ribavirin alone.
Bone Marrow Transplantation (2000) 25, 161-165.
PMID- 10673675
TI - Incidence, risk factors and outcome of varicella-zoster virus infection in
children after haematopoietic stem cell transplantation.
AB - We report a retrospective analysis of VZV infection after haematopoietic stem
cell transplantation (HSCT) in children. Thirty-three (30%) of the total 109
children who were transplanted during a 7 year period developed post-transplant
VZV infection. Twenty-four of these 33 (73%) children had VZV infection within 1
year following HSCT. The cumulative incidences of post-transplant VZV infection
at 1 and 5 years were 26% and 45%, respectively. The positive and negative
predictive values of pretransplant VZV serology in recipients on the development
of HZ following HSCT were 39% and 88%, respectively. Pretransplant VZV
seropositivity in recipients was the only risk factor for post-transplant herpes
zoster (HZ) infection on multivariate analysis. All patients responded to
acyclovir. The median duration of VZV infection was 5 days. Three (11%) and one
(3%) children with HZ developed visceral dissemination and post-herpetic
neuralgia, respectively. No mortality was directly attributed to VZV infection.
VZV infection remains a major cause of morbidity in children after HSCT. Further
studies are warranted to evaluate the potential use of VZV vaccine in these
children. Bone Marrow Transplantation (2000) 25, 167-172.
PMID- 10673676
TI - Evaluation of acute toxicities associated with autologous peripheral blood
progenitor cell reinfusion in patients undergoing high-dose chemotherapy.
AB - Peripheral blood progenitor cell reinfusion (PBPC) in patients undergoing high
dose chemotherapy (HDC) for poor prognosis malignancies, has been described as
causing possible acute gastrointestinal (nausea, vomiting), allergic (oedema,
bronchospasm, anaphyl- axis), renal (proteinuria, haematuria) and/or
cardiovascular (hypotension, arrhythmia, conduction disturbances, transient
ischaemic phenomena) toxicities. To establish the clinical relevance of these
observations and the possible relationship with different HDC regimens used, we
performed a clinical and instrumental evaluation on 33 patients with advanced
breast cancer, non-Hodgkin's lymphoma, Hodgkin's disease, relapsed ovarian
cancer, Ewing's sarcoma, extragonadal germinal tumour and small cell lung cancer.
They underwent at least one reinfusion each for a total of 51 studied procedures.
No patient had a previous history of cardiovascular disease or significant
intercurrent illness such as diabetes or liver, renal or neurologic impairment.
All patients had totally implanted central venous catheters, through which the
transplants had been collected and reinfused without technical consequences. To
evaluate cardiovascular function, we continuously monitored 12-lead ECGs, with
arterial pressure (AP) measurements every 5 min from the beginning of the
procedure to 15 min after the reinfusion ended. We did not observe any
significant differences between basal and subsequent steps in AP, heart rate, PQ
and QTc time, P wave and QRS complex duration or P wave and QRS electrical axes.
No patient showed any ST-T tract pathological abnormality, but one patient
developed a transient ectopic atrial rhythm, without any haemodynamic disfunction
and with spontaneous reversion to sinus rhythm. No patient complained of symptoms
of haemodynamic failure. Gastrointestinal side-effects appeared to be strictly
related to speed of reinfusion and to the number of packs reinfused, probably
reflecting on the amount of dimethylsulphoxide infused. In one patient a tonic
clonic seizure occurred during a vomiting episode, but no patient developed
allergic or renal toxicities. We conclude that PBPC reinfusion, if managed
according to the procedure we propose in patients without organic impairment, is
a safe procedure not associated either with increased risk of acute arrhythmias
or ischaemic or significant systemic acute toxicities. Bone Marrow
Transplantation (2000) 25, 173-177.
PMID- 10673677
TI - Anti-A isoagglutinin as a risk factor for the development of pure red cell
aplasia after major ABO-incompatible allogeneic bone marrow transplantation.
AB - Delayed erythropoiesis and pure red cell aplasia (PRCA) have been reported after
major ABO-incompatible BMT. We attempted to find risk factors for the development
of PRCA in 27 patients who underwent major ABO-incompatible BMT. In all patients,
the donor marrow was depleted of RBCs before infusion. In 22 patients,
isoagglutinins were determined until they disappeared. In eight (29.6%) out of 27
patients, bone marrow examination following BMT showed the findings of PRCA. We
analyzed various clinico-pathologic risk factors and isoagglutinin type was the
only significant risk factor. Patients with anti-A isoagglutinins against donor
RBC developed PRCA more frequently than patients with anti-B (8/17 vs 0/9).
Median days to the disappearance of isoagglutinins tended to be longer in
patients with PRCA (PRCA vsnon-PRCA, 200 vs 66 days) and in cases with anti-A
isoagglutinins (anti-A vsanti-B, 160 vs 51 days). Times to disappearance of
isoagglutinins correlated with times to reticulocytes over 1% and initial
appearance of donor type RBC (R2 = 0.708 and 0.711). In conclusion, RBC
engraftment following major ABO-incompatible BMT was dependent on the
disappearance of isoagglutinins against donor RBC, and anti-A isoagglutinin was a
risk factor for the development of PRCA after major ABO-incompatible allogeneic
BMT. Bone Marrow Transplantation (2000) 25, 179-184.
PMID- 10673678
TI - Cardiac conduction abnormalities in patients with breast cancer undergoing high
dose chemotherapy and stem cell transplantation.
AB - Cardiac toxicities in 39 consecutive patients with breast cancer receiving high
dose chemotherapy (HDC) with stem cell transplantation were reviewed. All 39
patients received various anthracycline-containing regimens in adjuvant settings
and/or for metastatic disease before HDC. As a cytoreductive regimen, all
received cyclophosphamide 2000 mg/m2 and thiotepa 200 mg/m2 for 3 consecutive
days. No immediate fatal toxicities were observed, but one patient developed
chronic congestive heart failure and two had transient left ventricular
dysfunction. Pericardial effusion was observed in another three patients. ST-T
abnormalities during HDC were observed in two patients and arrhythmias were
observed in nine, four of which occurred during stem cell infusion (SCI). There
were three atrial arrhythmias, two ventricular arrhythmias, and four
atrioventricular (AV)-block episodes. Two patients developed advanced and
complete AV-block with an asystolic pause. Notably, three patients experienced AV
block with uncontrolled vomiting. No relationship was observed between the
cumulative dose of anthracycline and cardiac toxicities during HDC. These results
suggest that abnormalities in the conduction system during HDC may be more
frequent than previously reported. Vagal reflex secondary to emesis may play an
important role in the development of AV-block. Bone Marrow Transplantation (2000)
25, 185-189.
PMID- 10673679
TI - Bone mass after allogeneic BMT for childhood leukaemia or lymphoma.
AB - The bone mass was measured by dual energy X-ray absorptiometry in 25 survivors of
childhood leukaemia or lymphoma (21 with ALL) who had received TBI and allogeneic
BMT a median of 8 years ago (range 4-13). Results were compared with local data
on 463 healthy controls and 95 survivors of childhood ALL treated without BMT.
Adjusted for sex and age, the mean whole-body bone mineral content (BMC) and bone
mineral areal density were significantly less than in healthy controls (0.8 and
0.5 s.d. less than predicted). The reduced BMC was caused by a significantly
reduced height for age, whereas bone area for height and BMC for bone area were
similar to controls. Less bone mass tended to be related to additional cranial
irradiation and age above 20 years at follow-up. Controlled for this, the whole
body bone mass seemed to be unrelated to previous chemotherapy and endocrine
status at follow-up and tended to be only marginally less in BMT patients than in
ALL survivors treated without BMT. In conclusion, 8 years after allogeneic BMT
for childhood leukaemia or lymphoma, the whole-body bone mass was only slightly
reduced and the size-adjusted bone mass (BMC for bone area) was normal. Bone
Marrow Transplantation (2000) 25, 191-196.
PMID- 10673680
TI - Evaluation of optimal survival of primitive progenitor cells (LTC-IC) from PBPC
apheresis products after overnight storage.
AB - Optimal overnight (ON) storage of PBPC aphereses is becoming an increasingly
important issue and different options for storing PBPC products exist. The
survival of primitive progenitor cells is of major interest, as recent data
suggest that these progenitors are not only important for long-term engraftment
but also contribute significantly to the early phase of hematopoietic engraftment
after myeloablative therapy. We therefore investigated the survival of primitive
progenitor cells (ie long-term culture initiating cells, LTC-IC) before (ie
within 2 h after finishing the apheresis procedure) and after ON storage lasting
16 to 20 h. In addition, we compared the % of recovery of LTC-IC with that of
mature progenitors (ie colony-forming cells, CFC) and with the % viability of the
mononuclear cells in the apheresis product. Aliquots of PBPC aphereses products
were tested in collection bags at room temperature (RT), in EDTA tubes both at RT
or 4 degrees C +/- the addition of autologous plasma (AP; 2.6-fold the apheresis
volume) and +/- the possibility of gas exchange. Mean viable cell counts did not
show strong differences between the different storage conditions and were poor
predictors for the survival of CFC and LTC-IC. At RT (collection bags, EDTA tubes
+/- gas exchange) recoveries (% of input) of both, CFC (18%, 18% and 31%) and LTC
IC (10%, 4%, 17%) were low. The addition of AP at RT improved the survival of CFC
and LTC-IC to 66% and 38%, respectively. Optimal recoveries for both types of
progenitors (CFC: 99%, LTC-IC: 109%) were obtained at 4 degrees C in the presence
of AP. In addition, a good correlation between the survival of CFC and LTC-IC was
obtained (r = 0.76) suggesting that the analysis of CFC may also allow some
conclusions to be drawn on the survival of LTC-IC. Bone Marrow Transplantation
(2000) 25, 197-200.
PMID- 10673681
TI - Busulfan clearance in renal failure and hemodialysis.
AB - The impact of hemodialysis on the clearance of busulfan was determined in a
patient with chronic renal failure undergoing autologous peripheral stem cell
transplantation for non-Hodgkin's lymphoma. The extraction ratio for busulfan
across the dialyzer was 0.530 +/- 0.026 at a blood flow of 400 ml/min, which
corresponds to a hemodialysis clearance of 2.23 +/- 0.11 ml/min/kg body weight.
Apparent oral clearance of busulfan without hemodialysis was 3.38 +/- 0.56
ml/min/kg. Thus, a 4 h hemodialysis session enhanced the apparent oral clearance
of busulfan by 65%. We conclude that hemodialysis effectively removes busulfan
from circulating blood, but a standard hemodialysis period (ie, 4 h) does not
significantly alter busulfan exposure. Bone Marrow Transplantation(2000) 25, 201
203.
PMID- 10673682
TI - Severe acute graft-versus-host disease occurring after syngeneic BMT for AML in a
patient not given prior cyclosporin A therapy.
AB - A syndrome akin to graft-versus-host disease in the recipient of syngeneic stem
cells is hitherto described as being milder, self-limiting and confined to the
skin. It is enhanced by prior cyclosporin A therapy. We describe here a recipient
of a syngeneic marrow transplant who did not receive priming with cyclosporin A
and yet developed severe and progressive graft-versus-host disease which
necessitated and responded to high-dose immunosuppressive therapy. We believe
that this is because the conditioning regimen in stem cell transplant acts to
reset the immune system enabling it to recognise 'self' antigens. Bone Marrow
Transplantation (2000) 25, 205-207.
PMID- 10673683
TI - Epstein-Barr virus-associated lymphoproliferative disease after a cord blood
transplant for Diamond-Blackfan anemia.
AB - A 7-year-old boy with Diamond-Blackfan anemia (DBA) developed lymphoproliferative
disease (LPD) after a cord blood transplant (CBT). 3.1 x 107/kg mononuclear cells
from an HLA one-locus mismatched CB were transplanted after conditioning with
total body irradiation (8 Gy), cyclophosphamide (200 mg/kg) and antithymocyte
globulin (10 mg/kg). Complete engraftment occurred on day 33 post transplant.
Despite the resolution of grade II graft-versus-host disease (GVHD), he died of
lymphoma on day 130 post transplant. The tumor was of donor origin, indicating
clonal proliferation of Epstein-Barr virus (EBV)-infected B cells. This is the
first report of EBV-LPD after CBT. Post-transplant LPD can be a serious EBV
associated complication of CB grafts. Bone Marrow Transplantation (2000) 25, 209
212.
PMID- 10673684
TI - A successful cord blood transplant in a child with second accelerated phase
chronic myeloid leukemia following lymphoid blast crisis.
AB - We describe a 5-year-old girl with Ph(+) CML who received a cord blood transplant
in a second accelerated phase after a very early lymphoid blast crisis. She was
induced into CR by ALL-directed chemotherapy and then maintained with IFN-alpha2b
together with weekly rotational chemotherapy. Nineteen months after diagnosis,
her mother gave birth to an HLA-compatible sibling, whose cord blood was
cryopreserved. The patient's second acceleration occurred 22 months after the CML
diagnosis. The subsequent conditioning regimen included busulfan 16 mg/kg, Ara-C
12 g/m2 and melphalan 140 mg/m2. In order to prevent GVHD, CsA alone was
administered, 3 mg/kg i.v. per day for a total of 40 days. The total number of
nucleated cells infused was 0.8 x 108/kg, with CD34+ cells 1.8 x 106/kg and CFU
GM 1 x 104/kg. Engraftment occurred on day +35. Respiratory distress, severe VOD
and grade II acute gastrointestinal GVHD complicated the post-transplant period.
No chronic GVHD occurred. The girl is alive 23 months after transplantation with
complete donor chimerism; both Ph chromosome and bcr/abl RNA are negative. Bone
Marrow Transplantation (2000) 25, 213-215.
PMID- 10673685
TI - Allogeneic peripheral blood cell transplantation for hypereosinophilic syndrome
with myelofibrosis.
AB - Patients with hypereosinophilic syndrome (HES) display a very heterogeneous
clinical picture ranging from asymptomatic cases to very aggressive forms. We
report a 38-year-old woman with progressive HES who developed severe
myelofibrosis and was treated by allogeneic stem cell transplantation, using
peripheral blood (PBSCT) instead of bone marrow as the source of progenitor
cells, after conditioning with cytoxan and busulphan. To the best of our
knowledge, this is the first case of HES with myelofibrosis treated with PBSCT.
The patient remains alive 8 months post-PBSCT, and bone marrow fibrosis has
significantly decreased following transplantation. Bone Marrow Transplantation
(2000) 25, 217-218.
PMID- 10673686
TI - Successful treatment of relapsed CML after cord blood transplantation with donor
leukocyte infusion IL-2 and IFNalpha.
AB - A 3-year-old girl with BCR/ABL-positive CML relapsed after related HLA-identical
cord blood transplantation. She was treated with three cycles of donor lymphocyte
(DLI) infusion from her 15-month-old brother. Interferon alpha was added after
the second DLI, whereas a trial of IL-2 had to be discontinued because of
increasing immature myeloid cells in the blood smear. No signs of GVHD were
observed, but she developed myelosuppression and needed one platelet and one red
blood cell transfusion. She achieved a molecular remission after 6 months with
transient molecular relapse followed by sustained remission for 15 months. Thus,
DLI with or without interferon alpha might prove to be a promising treatment
option with tolerable side-effects in relapsed CML after cord blood
transplantation. Bone Marrow Transplantation (2000) 25, 219-222.
PMID- 10673687
TI - Immunologic recovery of patients given CD34-selected peripheral blood progenitor
cell transplantation for malignant diseases.
PMID- 10673688
TI - Late-onset herpes simplex virus-associated interstitial pneumonia after
allogeneic bone marrow transplantation.
PMID- 10673689
TI - Extramedullary relapse in the so-called 'sanctuary' sites for chemotherapy after
donor lymphocyte infusion.
PMID- 10673690
TI - Establishing a BMT support group.
PMID- 10673691
TI - Engraftment syndrome after autologous peripheral blood stem cell transplantation
with high numbers of peripheral blood stem cells followed by granulocyte colony
stimulating factor administration.
PMID- 10673692
TI - Mobilization of hematopoietic progenitor cells with paclitaxel (taxol) as a
single chemotheraupetic agent, associated with rhG-CSF.
AB - We assessed the mobilization capacity of taxol with rhG-CSF, both as a single
chemotherapeutic agent and in the presence of cyclophosphamide (CY), and compared
the effect with yields achieved when mobilization was performed solely with rhG
CSF. Fifteen patients with breast cancer received taxol 170 mg/m2 (continuous
infusion, day 1) and rhG-CSF (8 microg/kg/day, from day 2 until the end of
apheresis) (T-G group), while seven breast cancer patients were additionally
treated with CY (4 g/m2) on day 2, followed by rhG-CSF starting at similar doses
on day 3 (T-CY-G group). The PBSC collections after taxol with/without CY were
compared with those of 30 breast cancer patients who had received rhG-CSF (8
microg/kg/day) for mobilization. No differences were found in the characteristics
of patients included in any of the three mobilization groups. The median yield of
CD34+ cells from all patients included in taxol containing schedules was 9 x
106/kg (range 2-26) collected with a median of one apheresis procedure (range 1
4). Leukaphereses began earlier in the T-G group (median day 8, range 7-10) than
in the T-CY-G group (median day 13, range 11-17). In most patients (20 out of 22)
who received taxol containing regimens, more than 2.5 x 106 CD34+ cells/kg, a
threshold considered to be sufficient for hematopoietic reconstitution, were
collected with a single apheresis. Those patients in the T-G group experienced
less neutropenic and thrombocytopenic days, with all neutropenic fever episodes
developing in patients treated with the T-CY-G schedule (43%). When considering
priming with rhG-CSF alone in our historical cohort of 30 breast cancer patients,
a significant detrimental effect was observed in comparison with taxol mobilizing
schedules, in the number of aphereses performed, in the total yield CD34+cells
and in the number of patients who achieved the target dose of 2.5 x 106/kg CD34+
cells within the first collection procedure. We conclude that taxol containing
schedules are effective in mobilizing PBSC and facilitate the collection of high
yields of CD34+ cells (usually more than 5 x 106/kg recipient body weight) with a
reduced number of apheresis procedures. Taxol, as a single agent with rhG-CSF,
exhibits less hematological toxicity than the combination chemotherapy
mobilization regimen including CY. Bone Marrow Transplantation (2000) 25, 231
235.
PMID- 10673693
TI - Prognostic significance of increased IL-10 production in patients prior to
allogeneic bone marrow transplantation.
AB - IL-10 is a potent immunosuppressant which inhibits allo-antigen-specific T cell
responses. In addition, IL-10 is a strong endogenous anti-inflammatory cytokine.
To investigate the role of IL-10 in the induction of acute GVHD following
allogeneic bone marrow transplantation (BMT) we performed a prospective study on
spontaneous IL-10 production by peripheral blood mononuclear cells (PBMNC) in 84
patients admitted for allogeneic BMT. High spontaneous IL-10 production by PBMNC
at the time of admission and prior to any preparative treatment correlated with a
subsequent low incidence of GVHD and transplant-related mortality (8%), as
compared to patients with low or intermediate IL-10 production (50%, P < 0. 01).
Our data demonstrate the prognostic significance of increased IL-10 production in
BMT patients and suggest a major role of IL-10 in maintaining immunobalance in
the setting of allogeneic BMT. Bone Marrow Transplantation (2000) 25, 237-241.
PMID- 10673694
TI - Highly purified CD34+ cells isolated using magnetically activated cell selection
provide rapid engraftment following high-dose chemotherapy in breast cancer
patients.
AB - The primary objective of this study was to evaluate the safety of infusion of
CD34+ cells, selected using a clinical scale magnetically activated cell sorting
device, assessed by time to hematological engraftment and incidence of adverse
events. Secondary objectives included evaluation of device performance in terms
of purity and recovery of the CD34+ cell product. Breast cancer patients suitable
for transplantation received cyclophosphamide and filgrastim for mobilisation,
followed by three leukaphereses. The products of the first two leukaphereses
underwent CD34+ cell selection. The product of the third leukapheresis was
cryopreserved unmanipulated. Following high-dose cyclophosphamide, thiotepa and
carboplatin, selected CD34+ cells were infused. In 54 patients who received
selected cells only, the median time to platelet recovery and neutrophil recovery
was 11 days (range 5-51) and 9 days (range 5-51), respectively. There were no
adverse events associated with infusion of selected cells. A total of 126
leukapheresis samples was available before and after selection for central CD34+
analysis. The median purity was 96.1% (27.4-99.4) and the median recovery was 52.
3% (15.2-146.3). These data show that cells selected using magnetically activated
cell selection provide safe and rapid engraftment after high-dose therapy. Bone
Marrow Transplantation (2000) 25, 243-249.
PMID- 10673695
TI - Efficacy of autologous stem cell transplantation in mantle cell lymphoma: a 3
year follow-up study.
AB - This study was designed to evaluate the efficacy of therapeutic intensification
with autologous stem cell transplantation (ASCT) for mantle cell lymphomas (MCL)
in terms of response rate, duration of response, and event-free and overall
survivals. Twenty-four patients with confirmed MCL responding to chemotherapy
received a high-dose chemo-radiotherapy regimen followed by ASCT. Transplantation
was performed during first-line therapy in nine cases, second-line in 13 cases
and third-line in two cases. The source of hematopoietic stem cells was
peripheral blood for 19 cases. At the time of ASCT, eight patients were in
complete remission (33%). Seventeen of the 24 cases received an intensified
regimen with TBI and seven received the BEAM or the BEAC regimen. After
transplantation, 19 patients were in CR (79%). Nine of these were alive in
continued CR at a median follow-up of 34 months, while seven relapsed at a median
of 18 months. One patient died from Pneumocystis carinii interstitial pneumonitis
and five patients developed secondary malignancies. With a median follow-up after
transplantation of 34 months, the 3-year event-free survival was 55% and the 3
year overall survival was 68%. These results indicate that therapeutic
intensification with ASCT might be an effective treatment for mantle cell
lymphomas. Bone Marrow Transplantation (2000) 25, 251-256.
PMID- 10673696
TI - Intensified preparative regimens and autologous transplantation in refractory or
relapsed intermediate grade non-Hodgkin's lymphoma.
AB - Between September 1986 and June 1998, 99 patients with relapsed or refractory IGL
received intensified preparative therapy and underwent autologous transplantation
at a single institution. Two intensified preparative regimens were used:
cyclophosphamide, etoposide, total body irradiation (CY-VP-TBI) (n = 66) and
cyclophosphamide, BCNU, etoposide (CBV) (n = 33). As clinical features and
results were not different for the two preparative regimens, results were
combined. For all patients undergoing autologous transplantation, 5-year
actuarial overall survival (OS) was 34% +/- 6%; 5-year event-free survival (EFS)
was 26% +/- 5%. For patients who responded to primary therapy, salvage therapy,
or both, OS was 42% +/- 7%; for non-responders to prior therapy, OS was 14% +/-
7%, P < 0.025. OS was better among patients responding to salvage therapy (50% +/
9%), than among patients who had a complete response to initial therapy, but
failed to respond or were untested/unevaluable with respect to salvage therapy
(26% +/- 10%; P < 0.025). On multivariate analysis, response to salvage therapy
was associated with survival following autologous transplantation (P < 0. 005).
Treatment related mortality was 9% overall and only 6% after G-CSF and GM-CSF
were introduced into routine clinical practice. High-intensity preparative
therapy is highly effective, with acceptable treatment-related mortality, in
patients with IGL who have responded to induction therapy, salvage therapy, or
both. The best responses are observed in patients responding to salvage therapy.
Randomized prospective studies will be needed to further define the role of
intensified preparative regimens. Bone Marrow Transplantation (2000) 25, 257-262.
PMID- 10673697
TI - The prophylactic potential of fludarabine monophosphate in graft-versus-host
disease after bone marrow transplantation in murine models.
AB - Fludarabine phosphate, a purine analogue currently used in the therapy of
hematological malignancies, is known to cause immunosuppression and long-lasting
T cell lymphopenia. In this study, the effect of fludarabine on murine graft
versus-host disease occurring after marrow transplantation across major and minor
histocompatibility barriers was evaluated. Survival of (BALB/c x C57BL/6)F1 mice
irradiated and transplanted across the major histocompatibility barrier with
C57BL/6 spleen cells, and subsequently treated with fludarabine was significantly
longer than that of the control animals (P < 0.0001). On the other hand,
fludarabine had no effect on the graft-versus-host disease and survival of CBA
mice transplanted by B10.BR and of BALB/c mice transplanted by B10.D2 spleen
cells across the minor histocompatability barrier. The results indicate that in
certain murine models, particularly a major mismatch, fludarabine has the
potential to induce bilateral tolerance and stable chimerism after marrow
transplantation. Bone Marrow Transplantation (2000) 25, 263-266.
PMID- 10673698
TI - Reconstitution of lymphocyte subpopulations after paediatric bone marrow
transplantation.
AB - We prospectively studied the reconstitution of lymphocyte subpopulations in a
group of 22 children, who survived disease-free at least 6 months after
allogeneic BMT for a haematological malignancy. Absolute counts of total
lymphocytes, B lymphocytes, T lymphocytes, and CD4+ helper T lymphocytes reached
the 5th percentile (p5) of age-matched reference values within 6 months after BMT
in 15, 17, 7 and 2 patients, respectively. In particular, CD4+ helper T
lymphocyte reconstitution was very slow. Unexpectedly, CMV reactivation had a
profound positive influence upon the number of CD4+ helper T lymphocytes in the
children. In five patients, absolute B lymphocyte counts above the 95th
percentile were reached from 6 months after BMT onwards, mimicking normal
ontogeny. Unlike normal ontogeny, the percentages of helper T lymphocytes
expressing the 'naive' CD45RA isoform were low and those expressing the 'memory'
CD45RO isoform were high in the first 3 months after BMT, as described before.
Thereafter, the CD45RA:CD45RO ratio slowly normalised. Also, CD7 expression was
absent on up to 90% of T lymphocytes in the first months after BMT, and on a
steadily decreasing percentage thereafter, as recently described in adults.
However, the absolute counts of CD45RO+/CD4+ and CD7-/CD4+ helper T lymphocytes
did not change significantly. So, we found no evidence of peripheral expansion of
previously primed donor-derived 'memory' T lymphocytes during the follow-up
period which spanned 1-18 months after BMT. The absolute counts of 'naive'
CD45RA+ helper T lymphocytes did not show a faster increase after BMT than in
adults, despite the presumed presence of a non-involuted thymus in children. Bone
Marrow Transplantation (2000) 25, 267-275.
PMID- 10673699
TI - Isolation of viruses from stools in stem cell transplant recipients: a
prospective surveillance study.
AB - We prospectively examined stool specimens for enteric viruses in 75 stem cell
transplant recipients (autologous 48, allogeneic 27) to determine the frequency
and significance of these infections. Only six patients (8%) had a positive
isolate. Five of these were allograft recipients (18%) compared to one autograft
recipient (2%) (P = 0.02). Unrelated donor BMT recipients were at the highest
risk for a viral isolate (OR = 10.5). Adenovirus was the commonest isolate (four
patients). One patient each had an echovirus, enterovirus and small round
structured virus identified. No correlation was found between the severity of
gastro-intestinal symptoms and detection of a viral pathogen. There was no
correlation with GVHD or CMV status. The only risk factor identified for
isolation of an enterovirus was allogeneic BMT from an unrelated donor. There was
a negative correlation with PBSC grafts. All the patients infected with an
enteric virus had concomitant infection with other pathogens, compared to only
18% of uninfected patients (P = 0.001). The non-relapse mortality of the infected
patients was 50% and only 7% in the uninfected patients (P = 0.01, OR = 12.5),
although the isolated virus was the direct cause of death in one patient only.
This study indicates a low rate of enteric virus isolation in recipients of PBSC
grafts, both autologous and allogeneic. However, unrelated donor BMT is
associated with a higher risk of enteric virus infection and an adverse outcome.
Bone Marrow Transplantation (2000) 25, 277-282.
PMID- 10673700
TI - A randomized placebo-controlled trial of lisofylline in HLA-identical, sibling
donor, allogeneic bone marrow transplant recipients. The Lisofylline Marrow
Transplant Study Group.
AB - The purpose of the study was to evaluate the effect of lisofylline (LSF) on
engraftment, regimen-related toxicities (RRT), and mortality in patients
undergoing allogeneic bone marrow transplantation (BMT). We performed a
multicenter, randomized placebo-controlled trial in 60 patients with hematologic
malignancies receiving BMT from HLA-identical sibling donors. Patients were
randomized to receive either placebo, 2 mg/kg LSF or 3 mg/kg LSF every 6 h,
beginning before conditioning and continuing to day 21 or hospital discharge.
Treatment groups were balanced with respect to conditioning regimen and disease
stage. However, significantly more patients in the 2 mg/kg LSF group were at high
risk for RRT due to performance status >/=1, age >/=40 years, and prior exposure
to CMV. Nausea and vomiting were the only adverse events observed in a higher
proportion of LSF-treated patients that led to study withdrawal in six of 42
patients (14%). The times to neutrophil recovery to >/=500/microl and platelet
recovery (>20 000/microl) were not improved by LSF treatment. Nevertheless, no
patient who received treatment with 3 mg/kg LSF developed a documented infection
between day 0 and 35 or had a serious or fatal infection between day 0 and 100 (P
= 0.003 vs placebo for both). The day-100 survival rate was also significantly
improved in the 3 mg/kg LSF group (89%), compared with either the 2 mg/kg LSF
(48%) or placebo (61%) groups (log-rank test, 3 mg/kg LSF vs placebo, P = 0.
026). We conclude that treatment with LSF 3 mg/kg reduced the incidence of
infections and improved 100-day survival in patients receiving related-donor
allogeneic bone marrow transplantation. Bone Marrow Transplantation (2000) 25,
283-291.
PMID- 10673701
TI - Pulmonary cytolytic thrombi: a newly recognized complication of stem cell
transplantation.
AB - Over the past 5 years we have recognized a new pulmonary complication of
hematopoietic stem cell transplantation (HSCT) associated with fever and
pulmonary nodules termed 'pulmonary cytolytic thrombi' (PCT). Retrospective
analysis of medical and radiographic records and pathologic material from 13 HSCT
recipients with PCT and a review of the Blood and Marrow Transplant Database for
all patients with radiographic evidence of pulmonary nodules or who underwent
open-lung biopsy from 1 January 1993 to 31 December 1998 (n = 1228) were
performed. The median age of patients with PCT was 11.9 years (range, 1.3-29.7
years). All patients developed fever at a median of 72 days (range, 8-343 days)
post transplant, followed by pulmonary nodules on chest CT. Eleven patients were
receiving therapy for active GVHD (acute, grades I-IV (n = 10); extensive chronic
(n = 1)). Biopsy of the pulmonary nodules revealed a unique pattern of necrotic,
basophilic thromboemboli with amorphous material suggestive of cellular breakdown
products. This was descriptively labeled 'pulmonary cytolytic thrombi'.
Immunohistochemical staining revealed entrapped leukocytes and disrupted
endothelium, but was negative for histiocytes. Cultures and immunohistochemical
stains were negative for infectious agents. Empiric therapy included systemic
corticosteroids (n = 9) and amphotericin (n = 7). Nine patients survive with
resolution of PCT at a median follow-up of 1.5 years. Bone Marrow Transplantation
(2000) 25, 293-300.
PMID- 10673702
TI - Neuropathological findings after bone marrow transplantation: an autopsy study of
180 cases.
AB - We prospectively evaluated the neuropathological complications of 180 patients
who underwent autopsy studies following bone marrow transplantation (BMT) (177
allogeneic, three autologous). The most frequent underlying disorders included
severe aplastic anemia (n = 55), chronic myelogenous leukemia (n = 53), acute
myelogenous leukemia (n = 24) and Fanconi anemia (n = 16). There were 114 males
and 66 females. Neuropathological findings were detected in 90.55% of the
patients. The most frequent findings were subarachnoid hemorrhages (SAH) (n =
57), intraparenchymal hemorrhages (IHP) (n = 49), fungal infections (n = 16),
Wernicke's encephalopathy (n = 10), microglial nodular encephalopathy (n = 10)
and neurotoxoplasmosis (n = 8). In only 17 patients was the brain within normal
limits. Survival time after BMT averaged 5.4 months and the majority of patients
died in the first 3 months post BMT (n = 105). Central nervous system (CNS)
pathology was the main cause of death in 17% of the patients (n = 31), with a
predominance of IHP in this particular group. Furthermore, the survival time of
these patients who died of CNS causes (96.3 days) was almost half of the survival
time of those who died of extra-cerebral causes (177.8 days) (P = 0.0162). IHP
(70. 96 vs27.22%) (P < 0.001), fungal infections (25.8 vs 8.88%) (P < 0. 001) and
toxoplasmosis (9.67 vs 4.44%) (P < 0.001) were significantly more frequent in the
group of patients who died due to CNS causes than in the control group. The
findings of this work provide a possible guide to the possible causes of
neurological syndromes following BMT. Bone Marrow Transplantation (2000) 25, 301
307.
PMID- 10673703
TI - Pulmonary toxicity following carmustine-based preparative regimens and autologous
peripheral blood progenitor cell transplantation in hematological malignancies.
AB - Sixty-five patients with hematological malignancies (25 multiple myeloma, 18
Hodgkin's disease, 22 non-Hodgkin's lymphomas) who received a carmustine-based
regimen followed by autologous PBPC transplantation, were studied retrospectively
to evaluate the incidence of post-transplant non-infective pulmonary
complications (NIPCs), risk factors predictive of NIPCs, and response to
steroids. Carmustine (BCNU) given i.v. at a dose of 600 mg/m2 was combined with
etoposide and cyclophosphamide in 40 patients (BCV regimen) and with etoposide
and melphalan in 25 patients (BEM regimen). Seventeen of 65 patients (26%) had
one episode of NIPCs. The median time to NIPCs was 90 days (52-289). Factors that
increased the risk of developing NIPCs on multivariate analysis were female sex
(P < 0. 001) and BCV regimen (P < 0.05). All patients with NIPCs received
prednisone at a dose of 1 mg/kg body weight for 10 days then tapered by 5 mg
every two days; complete response to steroids was achieved in 15 of 17 patients;
one unresponsive patient died of interstitial pneumonia. BCNU given at the dose
of 600 mg/m2 is well tolerated when associated with melphalan and etoposide. In
females and in patients receiving BCNU with cyclophosphamide, a BCNU dose
reduction may be advisable. Bone Marrow Transplantation (2000) 25, 309-313.
PMID- 10673704
TI - Mental disturbances during isolation in bone marrow transplant patients with
leukemia.
AB - The mental status of 39 leukemia patients, who received bone marrow transplants
(BMT), was studied during the period of isolation. Mental disorders (diagnosed
according to DSM-IV criteria) occurred in 16 patients (41%) during the
observation period. The most frequent diagnoses were adjustment disorders, with
anxiety and/or depression. Logistic regression analysis suggested higher Tension
Anxiety score in the Profile of Mood States (POMS) prior to isolation (P =
0.011), donation of the bone marrow from unrelated subjects (P = 0.026) and in
female patients (P = 0.033). The results are preliminary, but indicate a high
frequency of mental disturbances and highlight the importance of psychiatric
intervention in BMT patients. Bone Marrow Transplantation (2000) 25, 315-318.
PMID- 10673705
TI - Sequential vidarabine infusion in the treatment of polyoma virus-associated acute
haemorrhagic cystitis late after allogeneic bone marrow transplantation.
AB - Late onset haemorrhagic cystitis (HC) occurs in 20-30% of allogeneic bone marrow
transplant patients. Human polyomavirus BK (BKV) (or less frequently adenovirus)
may be involved in the pathogenesis of viral HC and can represent a serious post
transplant complication. Diagnosis and treatment of viral HC can be difficult and
has an uncertain outcome. We report the efficacy of sequential vidarabine in the
treatment of a patient with severe BKV-associated HC, despite the delay in
implementing therapy. Bone Marrow Transplantation (2000) 25, 319-320.
PMID- 10673706
TI - Typhlitis complicating autologous blood stem cell transplantation for breast
cancer.
AB - Three cases of typhlitis occurring during autologous blood stem cell
transplantation (ABSCT) for metastatic breast cancer are described. Typhlitis is
a rare complication of neutropenia and has uncommonly been reported in the
autologous transplant setting. Although it has been most commonly described in
children with leukemia, typhlitis has increasingly been reported in adult
leukemias and in association with neutropenia secondary to chemotherapy for a
number of solid tumors. Only five previous cases of typhlitis in the setting of
ABSCT have been described. Whereas diarrhea and fever are common toxicities
associated with high-dose chemotherapy, it is likely that many cases of typhlitis
go unrecognized. Bone Marrow Transplantation (2000) 25, 321-326.
PMID- 10673707
TI - Bone marrow transplantation in severe Glanzmann's thrombasthenia with
antiplatelet alloimmunization.
AB - Glanzmann's thrombasthenia is an autosomal recessive disorder characterized by a
lack of platelet aggregation due to the absence of platelet glycoprotein IIb and
IIIa. Usually, the disease leads to mild hemorrhage but sometimes bleeding is
severe enough to be life-threatening. We report the case of a 16-year-old girl,
presenting with very severe type 1 Glanzmann's thrombasthenia, successfully
treated with an HLA-identical sibling bone marrow transplant (BMT). We also
update the clinical and laboratory data of her brother, who had received a BMT 16
years ago for the same disease. In the light of these two cases and two others
published in the literature, we discuss the indications for BMT from HLA
identical sibling donors in Glanzmann's thrombasthenia. Alloimmunization against
the missing platelet GPIIb/IIIa complex and severity of bleeding episodes may
constitute sufficient criteria for allogeneic BMT after careful assessment of the
risk-benefit of such a procedure, although this remains exceptional in this
disease. Bone Marrow Transplantation (2000) 25, 327-330.
PMID- 10673708
TI - FK506-induced intractable leukoencephalopathy following allogeneic bone marrow
transplantation.
AB - FK506-related leukoencephalopathy has been reported to be reversible and readily
treated by discontinuation or reduction of FK506. We describe two pediatric cases
of FK506-related leukoencephalopathy following allogeneic bone marrow
transplantation, which could not be readily controlled. These cases show that
FK506-related leukoencephalopathy is not always reversible, and patients may
develop epilepsy. Bone Marrow Transplantation (2000) 25, 331-334.
PMID- 10673709
TI - Mild pre-transplant cardiomyopathy may not impair long-term quality of life after
bone marrow transplantation.
AB - An 8-year-old child with acute myeloid leukemia (AML), underwent an allogeneic
bone marrow transplant (BMT) from his HLA matched sister in spite of having a
mild cardiomyopathy. We followed the patient with periodic electrocardiograms
(ECG) and echocardiograms which have not worsened, and the patient's quality of
life is not compromised 14 years after BMT. Bone Marrow Transplantation (2000)
25, 335-336.
PMID- 10673710
TI - Syngeneic peripheral blood stem cell transplantation with brief immunosuppression
for severe aplastic anemia.
AB - We report the cases of two severe aplastic anemia (SAA) patients who were
successfully treated with syngeneic peripheral blood stem cell transplantation
(PBSCT) using immunosuppression without high-dose chemotherapy or irradiation for
conditioning. A 21-year-old woman with SAA of 6 years duration had been
transfused heavily before transplantation and had developed refractory
thrombocytopenia, chronic hepatitis and secondary hematochromatosis. Syngeneic
PBSCT with immunosuppression using ATG, methylprednisolone, and cyclosporin-A was
eventually performed without high-dose chemotherapy in September 1997. The second
syngeneic PBSCT with the same immunosuppression was successfully performed in a
35-year-old male patient who had had SAA for 3 months in November 1998.
Haemopoietic engraftment was rapid and sustained. There was no infection or
mucositis during the syngeneic PBSCT. The patients are currently 9 to 22 months
post-PBSCT without rejection. Our experience suggests that syngeneic PBSCT with
brief immunosuppression is an effective alternative to pretransplant high-dose
chemotherapy conditioning for SAA patients having syngeneic transplantation. Bone
Marrow Transplantation (2000) 25, 337-339.
PMID- 10673712
TI - Response to Dr furebring
PMID- 10673711
TI - Side-effects of amphotericin B lipid complex (Abelcet) in the Scandinavian
population.
PMID- 10673713
TI - The promise of nucleic acid vaccines.
AB - Establishing the effective use of 'naked' nucleic acids as vaccines would
undoubtedly be one of the most important advances in the history of vaccinology.
While nucleic acids show much promise for use as vaccine vectors in experimental
animals, not a single naked nucleic acid vector has been approved for use in
humans. Indeed, data from human clinical trials is scant: nucleic acid vaccines
have not been clearly demonstrated to have any convincing efficacy in the
prevention or treatment of infectious disease or cancer. Here we illustrate
possible mechanisms underlying effective nucleic acid vaccination. We focus on
progress that has been made in the improvement of their function. Additionally,
we identify promising new strategies and try to forecast future developments that
could lead to the real success of nucleic acid vaccines in the prevention and
treatment of human disease.
PMID- 10673714
TI - Gene therapy in the CNS.
AB - Gene therapy for neurological disorder is currently an experimental concept. The
goals for clinical utilization are the relief of symptoms, slowing of disease
progression, and correction of genetic abnormalities. Experimental studies are
realizing these goals in the development of gene therapies in animal models.
Discoveries of the molecular basis of neurological disease and advances in gene
transfer systems have allowed focal and global delivery of therapeutic genes for
a wide variety of CNS disorders. Limitations are still apparent, such as
stability and regulation of transgene expression, and safety of both vector and
expressed transgene. In addition, the brain adds several challenges not seen in
peripheral gene therapy paradigms, such as post-mitotic cells, heterogeneity of
cell types and circuits, and limited access. Moreover, it is likely that several
modes of gene delivery will be necessary for successful gene therapies of the
CNS. Collaborative efforts between clinicians and basic researchers will likely
yield effective gene therapy in the CNS.
PMID- 10673715
TI - Targeting adenovirus.
AB - The use of targeted viral vectors to localize gene transfer to specific cell
types holds many advantages over conventional, non-targeted vectors currently
used in gene therapy. The resulting improvements in gene localization from
targeted adenovirus vectors are likely to reduce immunogenicity and toxicity,
increase safety, and enable the systemic administration of these vectors for
multiple indications including cancer, cardiovascular disease, and inflammatory
disease. Recent advances in the biological understanding of adenovirus structure
and adenovirus receptor interactions have fueled the rapid development of
targeted adenovirus vectors. Two basic requirements are necessary to create a
targeted adenovirus vector: interaction of adenovirus with its native receptors
must be removed and novel, tissue-specific ligands must be added to the virus.
Two general approaches have been used to achieve these basic requirements. In the
'two-component' approach, a bispecific molecule is complexed with the adenovirus.
The bispecific component simultaneously blocks native receptor binding and
redirects virus binding to a tissue-specific receptor. In the 'one-component'
approach the adenovirus is genetically modified to ablate native receptor
interactions and a novel ligand is genetically incorporated into one of the
adenovirus coat proteins. Two-component systems offer great flexibility in
rapidly validating the feasibility of targeting via a particular receptor. One
component systems offer the best advantages in producing a manufacturable
therapeutic and in more completely ablating all native adenovirus receptor
interactions. The coming challenges for targeted adenovirus vectors will be the
demonstration that the technology performs in vivo. Ultimately, or in parallel,
'receptor-targeting' technology can be combined with improved adenovirus
backbones and with 'transcriptional targeting' approaches to create adenovirus
which deliver genes selectively, safely, and with little immune response.
PMID- 10673716
TI - Design and application of HSV vectors for neuroprotection.
AB - Herpes simplex virus has been extensively genetically modified for gene transfer
to nerve and other tissues, to create vectors that are devoid of viral gene
expression and toxicity. Recombinant vectors have been engineered to express
genes which protect neurons against toxic insults resulting in cell death,
including nerve growth factor (NGF) and anti-apoptotic genes (eg bcl-2). This
review describes experiments using HSV vectors expressing these gene products and
their potential protective role in ameliorating neurodegenerative processes in
animal model systems.
PMID- 10673717
TI - Regulated gene expression systems.
AB - Most gene therapy research to date has focused on solving the delivery problem-
getting genes efficiently and stably into target cells and tissues. Those working
on systems for regulating the expression of genes once delivered have often been
accused of trying to run before they can walk. Yet regulation is likely to be
essential if gene therapy is to realize its full potential as a mainstream
clinical option for delivering proteins. Dramatic progress has been made in
designing and testing systems in which expression is controlled by orally active
drugs. The next few years should see the first clinical trials of drug-regulated
gene therapies.
PMID- 10673718
TI - Evaluation of polyether-polyethyleneimine graft copolymers as gene transfer
agents.
AB - Cationic copolymers consisting of polycations linked to non-ionic polymers are
evaluated as non-viral gene delivery systems. These copolymers are known to
produce soluble complexes with DNA, but only a few studies have characterized the
transfection activity of these complexes. This work reports the synthesis and
characterization of a series of cationic copolymers obtained by grafting the
polyethyleneimine (PEI) with non-ionic polyethers, poly (ethylene oxide) (PEO) or
Pluronic 123 (P123). The PEO-PEI conjugates differ in the molecular mass of PEI
(2 kDa and 25 kDa) and the degree of modification of PEI with PEO. All of these
conjugates form complexes upon mixing with plasmids, which are stable in aqueous
dispersion for several days. The sizes of the particles formed in these systems
vary from 70 to 200 nm depending on the composition of the complex. However,
transfection activity of these systems is much lower than that of PEI (25 kDa) or
Superfect as assessed in in vitro transfection experiments utilizing a luciferase
reporter expression in Cos-7 cells as a model system. In contrast, conjugate of
P123 with PEI (2 kDa) mixed with free P123 (9:1(wt)) forms small and stable
complexes with DNA (110 nm) that exhibit high transfection activity in vitro.
Furthermore, gene expression is observed in spleen, heart, lungs and liver 24 h
after i.v. injection of this complex in mice. Compared to 1,2-bis(oleoyloxy)
(trimethylammonio) propane:cholesterol (DOTAP:Chol) and PEI (25 kDa) transfection
systems, the P123-PEI system reveals a more uniform distribution of gene
expression between these organs, allowing a significant improvement of gene
expression in liver.
PMID- 10673719
TI - Cell delivery, intracellular trafficking and expression of an integrin-mediated
gene transfer vector in tracheal epithelial cells.
AB - The mechanism of cell entry and intracellular fate of a gene transfer vector
composed of a receptor-targeting, DNA-condensing peptide, RGD-oligolysine, a
luciferase encoding plasmid DNA (pDNA) and a cationic liposome was examined. We
demonstrate by confocal microscopy, electron microscopy and subcellular
fractionation that the major mechanism of entry of the vector is endocytic. The
vector complex rapidly (5 min) internalizes into early endosomes, then late
endosomes and lysosomes. Entry involves, at least in part, clathrin-coated pit
mediated endocytosis since different conditions or drugs known to influence this
pathway modify both uptake of pDNA and its expression. The observed increase in
expression with addition of a lip some correlated with an increase in the rate of
transfer of the pDNA to lysosomes, a decrease in intracellular recycling and
exocytosis of the pDNA and an increase in the amount of pDNA in the nuclear
fraction. Trafficking within the cell involved endosome fusion and the acid
environment of the endosomes-lysosomes was beneficial for expression. After 30
min both the peptide and pDNA localized to the nucleus and the amount of intact
pDNA in the nuclear fraction was highest with liposome and peptide. A better
understanding of the cellular mechanisms by which vectors transfer to and traffic
in cells should help design improved vectors.
PMID- 10673720
TI - Variegation of retroviral vector gene expression in myeloid cells.
AB - We have comparatively evaluated the efficiency of a series of retroviral vectors
transducing the gp91-phox gene, whose defects are responsible for impaired
production of superoxide anion (O2-) by phagocytic cells and lead to the X-linked
form of chronic granulomatous disease (X-CGD). These vectors included four
constructs based on the MoMuLV backbone and expressing gp91-phox from the viral
long terminal repeat (LTR) or from internal promoters, and one construct based on
the myelotropic FMEV vector. Expression of the therapeutic gene from the MoMuLV
LTR was unsatisfactory after transduction of the PLB985 X-CGD knockout cell line
and of primary CD34+ hematopoietic progenitors from X-CGD patients. The presence
of either constitutive or inducible internal promoters did not result in
important improvements in the efficiency of O2- production and lowered the titers
of the viral preparations. In contrast, sustained levels of superoxide generation
were obtained upon transduction with the FMEV vector. To analyze the efficiency
of transgene expression at the single cell level, over 150 cellular clones were
generated from bulk cultures of PLB985 X-CGD cells transduced with this vector,
each one representative of an individual transduction event. These clones
revealed a markedly heterogeneous pattern of gp91-phox expression, ranging from
complete silencing to full restoration of superoxide production. Within each
clone, expression of the therapeutic gene correlated with the number of
expressing cells rather than with the average levels of expression from each
cell, indicating that at the single cell level, the proviral promoter is
regulated by a binary, on/off mechanism. Moreover, both transduced bulk and
clonal cell populations displayed a tendency to a progressive extinction of
expression over time, with a mechanism involving LTR methylation. The design of
novel retroviral vectors escaping silencing is highly desirable for efficient
gene therapy.
PMID- 10673721
TI - Type I consensus interferon (CIFN) gene transfer into human melanoma cells up
regulates p53 and enhances cisplatin-induced apoptosis: implications for new
therapeutic strategies with IFN-alpha.
AB - In this study, we describe the effects produced by the retroviral transduction of
human type I consensus IFN (CIFN) coding sequence into the 8863 and 1B6 human
melanoma cell lines, derived from a metastatic and a primary human melanoma,
respectively. Melanoma cell lines producing approximately 103 IU/ml of IFN were
obtained. Interestingly, cisplatin treatment of IFN-producing 8863 and 1B6
melanoma cells resulted in a three- to four-fold increase in the percentage of
apoptotic cells with respect to similarly treated parental or control-transduced
cell cultures. A similar effect, although less intense, was caused by cultivation
of parental melanoma cells in the presence of exogenous CIFN. The increased
susceptibility of the IFN-producing melanoma cell lines to cisplatin-induced
apoptosis was associated with an IFN-dependent accumulation of p53, which also
correlated with a decrease in Bcl-2 expression. Addition of exogenous CIFN to
parental melanoma cells resulted in similar although weaker modulations of p53
and Bcl-2 expression. Cisplatin administration to nude mice bearing 3-day-old IFN
producing 8863 tumors resulted in complete tumor regression, while only a partial
tumor inhibition was observed upon cisplatin treatment of mice bearing parental
or control-transduced 8863 tumors. Starting the cisplatin treatment 7 days after
tumor cell injection still resulted in a stronger inhibition of tumor growth in
the mice bearing IFN-producing 8863 tumors as compared with parental tumor
bearing mice. A comparable therapeutic effect was obtained after repeated
peritumoral administration of 103 IU of exogenous CIFN and cisplatin treatment.
Interestingly, a spontaneous tumor regression was observed in nude mice injected
with IFN-producing 1B6 cells, in contrast to the progressive tumor growth
occurring in mice receiving a similar inoculum of the parental or control
transduced 1B6 melanoma cells. Repeated peritumoral administration of 103 IU of
exogenous CIFN to mice bearing parental 1B6 tumors caused only a transient
inhibition of tumor growth. These results indicate that type I IFN gene transfer
is an effective approach for suppressing the tumorigenic phenotype of human
melanoma cells and for increasing the efficacy of anticancer drugs. These
observations, together with our previous findings showing the importance of IFN
alpha-T cell interactions in the generation of an antitumor response in mouse
models, underline the interest of using type I IFN in gene therapy strategies for
the treatment of human melanoma.
PMID- 10673723
TI - Publisher's announcement
PMID- 10673722
TI - The Journal of Human Hypertension and the millennium.
PMID- 10673724
TI - Myocardial texture in hypertrophic remodelling: new insight into ventricular load
and function?
PMID- 10673725
TI - Ultrasonic myocardial textural parameters and midwall left ventricular mechanics
in essential arterial hypertension.
AB - BACKGROUND: The evaluation of the systolic left ventricular performance in
hypertensive patients presents some problems related to left ventricular
hypertrophy (LVH) which alters the ventricular geometry. The videodensitometric
textural ultrasonic analysis of hypertensive myocardium has provided evidence of
impairment in the cyclic variation of the mean gray level. This might be
considered as an index of intrinsic myocardial function. OBJECTIVES: The aim of
the present study was to analyse the connection between the midwall fractional
shortening and end-systolic stress. The ultrasonic textural parameters in
hypertensive patients, arranged in different groups according to the level of LVH
and relative wall thickness, were also evaluated. METHODS: A group of age-matched
(58 +/- 7 years) male essential hypertensive patients (n = 70) were compared to a
group of normotensive and healthy subjects used as controls (n = 32). All
subjects performed a conventional 2D-Doppler echocardiography to analyse the left
ventricular performance. A quantitative analysis of the echocardiographic
digitised imaging was also carried out with the help of a calibrated digitization
system in order to calculate the septum and the posterior wall textural
parameters. The myocardial mean gray level was calculated to derive the cyclic
variation index (CVI). RESULTS: When subjected to a higher meridional end
systolic stress, the hypertensive patients showed a significantly lower midwall
fractional shortening than the control patients. The CVI was also significantly
lower in the hypertensives group, both for the septum wall (-16.3 +/- 22.8 vs34.7
+/- 15.3%; P < 0.001) and the posterior wall (-5.2 +/- 23.6 vs 38.2 +/- 15.4%; P
< 0.001). A significant correlation was found between the midwall fractional
shortening (MFS) and the textural parameters, and between these two variables and
the end-systolic stress. CONCLUSION: The CVI was found to be a highly sensitive
parameter in the identification of abnormal echodensity in essential
hypertension. The CVI was significantly lower in patients with concentric
hypertrophy in comparison with other left ventricular geometric models. This
parameter could be considered as an index of the intrinsic myocardial function,
being related, in essential hypertension, to midwall fractional shortening and to
end-systolic stress. Journal of Human Hypertension (2000) 14, 9-16.
PMID- 10673726
TI - Beta-adrenergic receptor density and function in left ventricular hypertrophy in
young essential hypertensives.
AB - A sympathetic overactivity has been reported in the early stages of essential
hypertension and has been involved in the pathogenesis of left ventricular
hypertrophy (LVH) in essential hypertension. The state of beta2-adrenergic
receptors as related to the presence of this complication was investigated in a
group of 15 essential hypertensive patients and compared to 10 normotensive
control subjects. Left ventricular mass index was determined by bidimensional
echocardiography. Plasma catecholamine levels were measured by a radioenzymatic
assay. beta2-adrenoceptor density was measured in intact lymphocytes by
radioligand binding assay, using the hydrophilic ligand CGP 12177. beta2-
adrenoceptor function was assessed by measuring intracellular cAMP levels in
isoproterenol-stimulated lymphocytes. Left ventricular mass index (P < 0.05),
body mass index (P < 0.01), plasma noradrenaline levels (P < 0.05) and beta2
adrenoceptor density (P < 0.05) were higher in hypertensives than in controls.
Left ventricular mass index correlated with body mass index both in normotensives
and hypertensives, as well as with plasma noradrenaline levels only in
normotensives. Left ventricular mass index also showed a positive correlation
with mean arterial pressure and an inverse relationship with beta2-adrenoceptor
density and response only in hypertensive patients. In conclusion, left
ventricular hypertrophy in young essential hypertensives is associated to a
reduced beta2-adrenoceptor density and function, probably as a compensating
mechanism of the hypertrophied myocardiocyte secondary to the increased
sympathetic outflow. Journal of Human Hypertension (2000) 14, 17-21.
PMID- 10673727
TI - Relationships between cardiovascular remodelling and the pulse pressure in never
treated hypertension.
AB - The role of pulse pressure (PP) in cardiovascular remodelling was studied in 61
never treated hypertensive subjects who were selected on the criteria of
ambulatory blood pressure (BP) monitoring (mean BP over 24 h: 147 +/- 14/96 +/-
10 mm Hg). Echocardiography and carotid ultrasonography were performed and the
vascular images analysed using a specific automatic measuring program. Thirty
percent of subjects had left ventricular hypertrophy (LVH). Left ventricular mass
index (LVMI) was related to the clinic (r = 0.35) and ambulatory (r = 0.41 over
24 h, r = 0.38 daytime and r = 0.42 night-time) PP and to the systolic BP. PP was
higher when there was LVH. Vascular thickening was found in 6.6% of subjects
(carotid intima-media thickness (IMT) >/=1.0 mm). Among the BP parameters, IMT
and cross-sectional area (CSA) were related only to the clinic PP (r = 0.27, r =
0.29 respectively) and to the ambulatory PP (over 24 h: r= 0.29, r = 0.28;
daytime: r = 0.22, r = 0.23; night-time: r = 0.32, r = 0.30). In men, the
relationship between CSA and PP (clinic and over 24 h) was independent of age. A
total of 16.7% of subjects with LVH had intima-media thickening in contrast to
2.3% in the group without LVH. LVMI was related to the CSA (r = 0.37) and to the
IMT (r = 0.31). However, after multivariate analysis taking into account the PP,
relationships between IMT or CSA and LVMI disappeared. Our data showed that the
PP was the most important BP parameter in the development of cardiac and arterial
remodelling in hypertension. Journal of Human Hypertension (2000) 14, 23-30.
PMID- 10673728
TI - The mercury sphygmomanometer should be abandoned before it is proscribed.
AB - Both in clinical practice and medical research, blood pressure is still largely
measured by auscultation using a mercury sphygmomanometer. Blood pressure is the
most important predictor of life expectancy. Treatment of high blood pressure
reduces strokes, heart attack and heart failure. Accurate measurement is
therefore essential. At a large London teaching hospital, just under 500 mercury
sphygmomanometers and their associated cuffs were examined. More than half had
serious problems that would have rendered them inaccurate in measuring blood
pressure. At the same time, assessment of the technical knowledge needed to
measure blood pressure by the ausculatory technique was also carried out amongst
medical and nursing staff. This showed a considerable level of ignorance. These
results inevitably lead to inaccurate measurement of blood pressure with serious
consequences. In addition mercury is a non-degradable pollutant, eventually
accumulating on the sea bed. The use of mercury in sphygmomanometers is already
in the process of being eliminated in Scandinavia and Holland and other countries
are likely to follow. Our results suggest that mercury sphygmomanometers are not
adequately maintained and require expertise that is not available for accurate
measurement of blood pressure. Their use should be dispensed with on these
grounds before a ban for other and, perhaps less justifiable reasons. Validated
automatic devices, which are less liable to measurement and observer error should
be used instead. At the same time a concerted effort is needed to instruct health
care professionals on the importance of more accurate measurement of blood
pressure. Journal of Human Hypertension (2000) 14, 31-36.
PMID- 10673729
TI - In-field validation of automatic blood pressure measuring devices.
AB - The method for rapid evaluation of automatic blood pressure (BP) measurement
devices (READ) is based on numerous BP measurements at rest and during a
standardised postural challenge in a small number of subjects with a wide range
of BPs. The present study proposes additional parameters of the READ for in-field
validation of automatic BP measurement devices. BP measurements were done in
supine position for 10 min followed by head-up tilt for 30 min and again supine
for 10 min. BPs were determined simultaneously by automatic (AU) and mercury
sphygmomanometric (MS) measurements on the same arm. The BP differences
DeltaBP:AU-MS were calculated. Three units of the Colin BP-8800 and the Datex
Engstrom Cardiocaptrade mark II were evaluated. Based on DeltaBP(AU-MS), the
grade of accuracy, aberration patterns and correlates of accuracy were assessed
for each unit. Per unit, an average of 121 measurements were done, every BP
category being met in >/=20 MS measurements. In general, the AU systolic BP
values were higher than MS systolic BP values (mean systolic DeltaBP = 1.26 +/-
17.1 mm Hg) and AU diastolic BP values were lower than MS diastolic BP values
(mean diastolic DeltaBP = -12.31 +/- 7.8 mm Hg). All units classified into
category D of the British Hypertension Society grading system and exhibited
inconsistent aberration patterns, making design of correction formulas
impractical. Inaccuracy of the instruments was independent on mode of
measurement, posture, magnitude of the BP and heart rate, early or late
measurements from beginning of the head-up tilt test, and prolonged use of the
unit. The READ permitted to identify rapidly the degree of accuracy of automatic
BP measuring devices. Identification of the aberration pattern of an instrument
could be the basis for calculating equations for correction of the measured BP.
Further studies will show which parameters of the READ may expose specific
defects of the instruments. Journal of Human Hypertension (2000) 14, 37-42.
PMID- 10673730
TI - Role of the Gly460Trp polymorphism of the alpha-adducin gene in primary
hypertension in Scandinavians.
AB - Previous studies have suggested that the Trp460 allele of the Gly460Trp
polymorphism in the alpha-adducin gene is associated with salt sensitivity and
primary hypertension. The present study was undertaken to evaluate if the Trp460
allele of this polymorphism is associated with primary hypertension in
Scandinavians. To address this issue, 294 patients with primary hypertension and
265 normotensive control subjects from Sweden were examined and genotyped for the
Gly460Trp polymorphism using polymerase chain reaction and restriction fragment
length polymorphism methods. We then used a population of 80 patients with
primary hypertension and 154 normotensive control subjects from Finland to
replicate the findings. The frequency of the Trp460 allele was lower in
hypertensive patients than in normotensive controls in the Swedish population
(17.7% vs 23.0%; P = 0.03) and in the Finnish population (14.4% vs 19.5%; NS).
Therefore we also performed a pooled analysis in which the frequency of the
Trp460 allele was significantly lower in hypertensive patients than in
normotensive controls (17.0% vs 21. 7%; P = 0.02). In subjects who did not
receive antihypertensive medication (n = 447) there was no difference between
carriers of the three different codon 460 genotypes (Trp-Trp; Trp-Gly and Gly
Gly) either for systolic (128 +/- 18; 127 +/- 15 and 129 +/- 17 mm Hg, NS) or for
diastolic blood pressure (75.6 +/- 12.1; 74.7 +/- 9.3 and 75.0 +/- 10.4 mm Hg,
NS). In conclusion, the lower frequency of the Trp460 allele in hypertensive
patients than in normotensive controls strongly argues against a pathogenic role
of this allele in primary hypertension. The results rather suggest that another
variant in linkage disequilibrium with the Gly460Trp polymorphism increases
susceptibility for hypertension. Journal of Human Hypertension (2000) 14, 43-46.
PMID- 10673731
TI - Lack of association between ACE gene polymorphism and left ventricular
hypertrophy in essential hypertension.
AB - The possible association between the insertion/deletion (I/D) polymorphism of the
angiotensin I converting enzyme (ACE) gene and left ventricular hypertrophy (LVH)
was investigated in a group of essential hypertensive patients. Seventy-one
essential hypertensive patients (35 men and 36 women), aged 51 +/- 1 years, were
genotyped by PCR for the I/D polymorphism of the ACE gene. Cardiac morphology and
function were assessed by means of M-mode echocardiography. The relative
frequencies of the three genotypes, DD, DI, and II, were respectively: 24%, 55%,
and 21%. Mean values of left ventricular mass index were 145, 144, and 150 g/m2
for DD, DI, and II genotypes, without significant differences among them (P =
0.82). Likewise, the prevalence of LVH (76%, 64%, and 87%) was not significantly
different among the three genotypes (P = 0.23). We conclude that the ACE gene I/D
polymorphism is not associated with LVH in essential hypertension. Journal of
Human Hypertension (2000) 14, 47-49.
PMID- 10673732
TI - Differences in insulin sensitivity and risk markers due to gender and age in
hypertensives.
AB - Men run a higher risk for cardiovascular disease than women, even if
hypertensive. This has been attributed to a more pronounced central (abdominal)
fat distribution in men as well as menopausal state in women. The hypothesis to
be tested in hypertensives was that men have more pronounced insulin resistance
and other cardiovascular risk factors than pre-menopausal, but not post
menopausal, women. We carried out a cross-sectional observation study of middle
aged hypertensives of both sexes, divided into two age groups, below or over 50
years of age. The study was performed in untreated out-patients, visiting a
hypertension policlinic, in Uppsala, Sweden. Three hundred men and 170 women with
a mean age of 57 years were investigated. Measurements were taken by: physical
examination (body mass index, waist-to-hip ratio, blood pressure); intravenous
glucose tolerance test (IVGTT); euglycaemic hyperinsulinaemic clamp; and blood
sampling for lipoprotein lipid fractions, uric acid, and free fatty acids. The
results were that pre-menopausal women showed a higher insulin-mediated glucose
disposal (7.6 vs5.8 mg/kg/min; P < 0. 01), and lower fasting glucose (4.9 vs 5.2
mmol/l; P < 0.05) than men, as well as a more advantageous lipoprotein profile.
However, in post menopausal women insulin sensitivity decreased and the
lipoprotein profile deteriorated. Women still showed higher levels of high
density lipoprotein (HDL)-cholesterol, and men a higher waist-to-hip ratio and
levels of uric acid, in both age groups. It was concluded that post-menopausal
hypertensive women are relatively more insulin resistant than pre-menopausal ones
in comparison with men in the same age group and with the same degree of overall
obesity. Journal of Human Hypertension (2000) 14, 51-56.
PMID- 10673733
TI - Salt-induced exacerbation of morning surge in blood pressure in patients with
essential hypertension.
AB - The morning surge in blood pressure (BP) is related to the morning occurrence of
lethal cardiovascular events. We tested the hypothesis that salt intake may be
associated with the morning surge in BP in essential hypertension. Seventy-six
patients were admitted and placed on a low salt diet (2 g/day) for 7 days
followed by a high salt diet (20-23 g/day) for another 7 days. At the end of each
salt diet, 24-h ambulatory BP and heart rate monitorings and head-up tilt (HUT)
test were performed. Patients whose average mean BP (MBP) was increased by more
than 10% by salt loading were assigned to the salt-sensitive (SS) group (n = 37);
the remaining patients, whose MBP was increased by less than 10%, were assigned
to the non-salt-sensitive (NSS) group (n = 39). The increase in ambulatory MBP
during 6.30-8.00 am above the baseline (2.00-4.00 am) was significantly enhanced
by salt loading in the NSS group (P < 0.05), but not in the SS group. The
coefficient of variation of 24-h MBP and heart rate was increased by salt loading
only in the NSS group. The significant elevation of plasma noradrenaline
concentration after awakening, which was noted during the low salt diet period,
was unchanged during the high salt diet period in the NSS group, but abolished in
the SS group. Salt loading enhanced HUT-induced decrease in systolic BP without
affecting the heart rate response only in the NSS group. We conclude that the
morning surge in BP is enhanced by salt loading in the NSS type of essential
hyper- tension, presumably by the excessive activation of the sympathetic nervous
system. Journal of Human Hypertension (2000) 14, 57-64.
PMID- 10673734
TI - Correlates of blood pressure in an urban Zimbabwean population and comparison to
other populations of African origin.
AB - We have evaluated the relationship between systolic blood pressure (SBP) and age,
body mass index (BMI), waist circumference, sodium to potassium ratio (Na/K), and
tobacco use in an urban African population. We conducted a random, population
based, cross-sectional survey of people 25 years and older in Marondera,
Zimbabwe, with over-sampling in older age groups (n = 775), using a method
comparable to that used in International Collaborative Study on Hypertension in
Blacks (ICSHIB). The age-adjusted prevalences of hypertension in Marondera (SBP
>/=140/DBP >/=90/antihypertensive medication) were 30% for women and 21% for men.
The average BMI was 26.3 kg/m2 for women and 21.4 kg/m2 for men. The prevalence
of hypertension had a steep association with age and in women ranged from 15% (25
34 years) to 63% (55 years and over) and in men from 9% to 47%. No tobacco use in
women and greater Na/K ratio in spot urines in men were significantly associated
with an increased SBP. In both men and women the levels of hypertension and SBP
were strongly positively associated with BMI, although the relationship appeared
to plateau in women with a BMI greater than >/=25 kg/m2. At a given BMI, men and
women had similar SBPs and prevalences of hypertension. There is a very high
prevalence of hypertension among urban Zimbabweans, particularly among women.
Under the assumption the studies are comparable, the prevalence of hypertension
in Zimbabwean women (41%) and men (26%) after age adjustment to the ICSHIB
populations, appeared higher than almost all of the ICSHIB populations, including
those with higher average body mass indexes. Journal of Human Hypertension (2000)
14, 65-73.
PMID- 10673735
TI - Does the Dundee Step Test predict outcome in treated hypertension? A sub-study
protocol for the ASCOT trial. Anglo-Scandinavian Cardiac Outcome Trial.
AB - Treated hypertensive subjects may remain five times more likely to die of cardiac
and cerebrovascular diseases than normotensive subjects with equivalent resting
blood pressure (BP) levels. Research evidence suggests that exercise BP is a
better predictor of end-organ damage and mortality than resting BP, and data from
our centre show that a significant proportion of treated hypertensives have
uncontrolled BP during a 5-min Dundee Step Test. The prognostic usefulness of
exercise BP has yet to be translated into clinical practice because of the lack
of a suitable technique. The Dundee Step Test is being evaluated in the ASCOT
(Anglo-Scandinavian Cardiac Outcome Trial) study, a 5-year follow-up multicentre,
multinational trial comparing the effect of newer (amlodipine and perindopril)
and older (bendroflumethiazide and atenolol) antihypertensive agents stratified
according to cholesterol levels on cardiac outcome. If the value of the Dundee
Step Test is proven, then it may be adopted into routine clinical practice for
the assessment of exercise BP. This may result in the improved management of
hypertension with a subsequent reduction in morbidity and mortality. The
publication of this study protocol is meant to be a statement of on-going
research which may stimulate interest among those with an interest in this area
of research. Journal of Human Hypertension (2000) 14, 75-78.
PMID- 10673736
TI - Individualized methotrexate dosing in children with relapsed acute lymphoblastic
leukemia.
AB - Although high-dose methotrexate has been extensively studied in children with
newly diagnosed acute lymphoblastic leukemia (ALL), there are fewer data in
children with relapsed ALL, many of whom have been heavily pretreated and have
subclinical kidney dysfunction. We characterized the pharmacokinetics of
adaptively controlled methotrexate given as a 24-h infusion during consolidation
therapy in 24 children with relapsed ALL. To achieve the target steady-state
concentration of 65 microM, dosage adjustments were required in 14 patients, with
doses ranging from 2854 to 6700 mg/m2 per course. The mean steady-state plasma
concentration (Cpss) of 68.0 microM was different (P = 0.025) than the predicted
Cpss (mean = 87.4 microM; range 35.7-184 microM) had no adjustment in dose been
made. The coefficient of variation in Cpss was reduced from 41% to 18% by
individualizing doses. Predisposing factors that correlated with decreased
methotrexate clearance were female sex (P = 0.03), age greater than 6 years (P =
0.01), and prior history of heavy amphotericin B treatment (>30 mg/kg) (P =
0.03), but no factor predicted low clearance as well as the measured initial
methotrexate clearance during the infusion (P < 0.0001). There was no life
threatening toxicity with the regimen. We conclude that dosage individualization
decreases interpatient variability and avoids potentially toxic methotrexate
exposures in heavily pretreated ALL patients.
PMID- 10673737
TI - Multivariate analysis of prognostic factors in patients with refractory and
relapsed acute myeloid leukemia undergoing sequential high-dose cytosine
arabinoside and mitoxantrone (S-HAM) salvage therapy: relevance of cytogenetic
abnormalities.
AB - To improve the basis for the stratification of patients with refractory and
relapsed acute myeloid leukemia (AML) univariate and multivariate analyses of
prognostic factors were performed in 254 patients (median age 50 years, range 18
74) undergoing S-HAM salvage chemotherapy during two consecutive prospective
trials of the German AML Cooperative Group. In a multivariate analysis, duration
of the first complete remission (CR) was the only factor associated with time to
treatment failure (P = 0.0223). Disease-free survival was influenced by a short
duration of the first CR of less than 6 months (P = 0.0001), WBC (P = 0.0018),
blast count (P = 0.0037), and neutrophil count (P = 0.0119). The achievement of
CR was related to the hemoglobin level only (P = 0.0457), the early death rate
was related to age only (P = 0.0109), and survival was related to the bilirubin
level only (P = 0.0166). In the subgroup of 104 patients in whom additional
karyotype analyses were performed prior to first-line therapy unfavorable
chromosome abnormalities were associated with a lower CR rate (univariate
analysis, P = 0.0342; CR 24% vs 53%) and were the only factor related to
survival. These analyses warrant the further evaluation of the impact of
cytogenetic abnormalities on the outcome of patients with advanced AML in order
to improve the characterization according to duration of first CR and to WBC of
distinct subgroups of patients with differing prognoses as a basis for
stratification in future trials.
PMID- 10673738
TI - Glutathione S-transferase genotypes in children who develop treatment-related
acute myeloid malignancies.
AB - Epipodophyllotoxin-associated secondary myeloid leukemia is a devastating
complication of acute lymphoblastic leukemia (ALL) therapy. The risk factors for
treatment-related myeloid leukemia remain incompletely defined. Genetic
deficiencies in glutathione S-transferase (GST) activities have been linked to
higher frequencies of a number of human malignancies. Our objective was to
determine whether the null genotype for GSTM1, GSTT1, or both, was more frequent
in children with ALL who developed treatment-related myeloid malignancies as
compared to those who did not. A PCR technique was used to assay for the null
genotype for GSTM1 and GSTT1 in 302 children with ALL, 57 of whom also
subsequently developed treatment-related acute myeloid leukemia or
myelodysplastic syndrome. Among children with ALL who did not develop treatment
related myeloid malignancies, the frequencies of GSTM1 and GSTT1 wild-type, GSTM1
null-GSTT1 wild-type, GSTM1 wild-type-GSTT1 null, and GSTM1 and GSTT1 null
genotypes were 40%, 42%, 9% and 9%, respectively. The corresponding frequencies
for patients who developed acute myeloid malignancies were 42%, 32%, 11% and 16%,
respectively (P = 0.26). A statistically significant increase in the frequency of
the GST null genotype was observed in male patients who developed myeloid
malignancies as compared to male ALL control patients (P = 0.036), but was not
observed in female patients (P = 0.51). Moreover, a logistic regression analysis
of possible predictors for myeloid malignancies, controlling for gender and race,
did not reveal an association of GSTM1 or GSTT1 null genotypes (P = 0.62 and
0.11, respectively) with treatment-related malignancies. Our data suggest that
GSTM1 and GSTT1 null genotypes may not predispose to epipodophyllotoxin
associated myeloid malignancies.
PMID- 10673739
TI - Acute lymphoblastic leukemia with an unusual t(8;14)(q11.2;q32): a Pediatric
Oncology Group Study.
AB - We present the clinicopathologic findings and survival data on 10 patients with
acute lymphoblastic leukemia (ALL) and a rare t(8;14)(q11.2;q32). There were five
male and five female patients, nine Caucasians and one Black, aged 4-17 (median
10.9) years. Three had Down syndrome. Eight (80%) patients had a white blood cell
(WBC) count <50 x 109/l at presentation. No patient had central nervous system
involvement or a mediastinal mass. Two patients had concurrent splenomegaly and
hepatomegaly. Adenopathy was absent in four, minimal in three, moderate in one
and prominent in two patients. All eight cases where immunophenotyping was
performed by flow cytometry showed a B-precursor phenotype with expression of
CD10 (CALLA). Only one case exhibited t(8;14)(q11.2;q32) as the sole karyotypic
abnormality. Three patients were classified as standard-risk and seven high-risk
by NCI (National Cancer Institute) consensus risk group categories. All patients
achieved complete remission and seven patients were in complete continuous
remission (CCR) after chemotherapy designed for B-precursor ALL. Three patients
relapsed after 23.5, 31.3 and 32.1 months of EFS; the first patient also had
t(9;22)(q34;q11), the second had a WBC count of 126 x 109/l at presentation while
the third patient had no high risk features except for age 10 years. Thus, from
our data, the t(8;14)(q11.2;q32) does not appear to confer an increased risk of
relapse. Further observations are needed to confirm this conclusion.
PMID- 10673740
TI - Monosomy 20 as a pointer to dicentric (9;20) in acute lymphoblastic leukemia.
AB - Twenty new cases of acute lymphoblastic leukemia (ALL) with the dicentric
chromosome dic(9;20)(p1113;q11) are presented. This chromosomal abnormality is
difficult to identify from G-banding alone. It masquerades as monosomy 20 and is
only accurately identified by fluorescence in situ hybridization (FISH). Monosomy
20 was found in 59/2790 patients with successful karyotypes entered to the
Leukaemia Research Fund/UK Cancer Cytogenetics Group Karyotype Database in ALL
(LRF/UKCCG Karyotype Database). FISH revealed dic(9;20) in 20/25 cases with
available material. Extra copies of chromosome 21 were found in 8 of the 20
cases. Patients were 14 females and six males, aged 1-32 years (median 4 years),
with leukocyte counts of 2-536 (median 23) x 109/l and immunophenotypes of common
or pre-B ALL (17 cases), T-ALL (one case) or unknown (two cases). Four patients
relapsed at 2, 22, 28 and 47 months and two died at 49 and 63 months (median
follow-up 37 months). FISH studies on the remaining five patients showed one with
monosomy 20 and four with other rearrangements of the chromosome. This study has
increased the number of reported cases of dic(9;20) from 17 to 37. It has
identified dic(9;20) in one case of T-ALL and shows an association of this
translocation with trisomy 21.
PMID- 10673741
TI - Minimal residual disease is common after allogeneic stem cell transplantation in
patients with B cell chronic lymphocytic leukemia and may be controlled by graft
versus-host disease.
AB - Following allogeneic stem cell transplantation (SCT), we studied the presence of
donor and recipient derived cells within the CD19+ B cell fraction, in patients
with B cell chronic lymphocytic leukemia (CLL). The chimeric status of the six
patients studied was further investigated with minimal residual disease (MRD)
detection, by sequencing and using patient-specific primers derived from
junctional regions of clonally rearranged immunoglobulin heavy-chain (IgH)
receptor genes. To date, five of six patients are alive with a median follow-up
time of 24 months (range 15-60) post-SCT. All patients experienced acute and
chronic graft-versus-host disease and responded clinically to SCT. All patients
were MRD positive after SCT, which correlated to mixed chimerism within the CD19+
cell fraction in all samples except one (25/26). High levels of tumor necrosis
factor-alpha (TNF-alpha) and soluble interleukin-2 receptor (sIL-2R) indicated
advanced disease, and patients with increased levels pre- and post-SCT were also
those with the most long-lasting PCR-detectable MRD post-SCT. Hence, a high tumor
burden pre-SCT may reflect the long duration of detectable MRD in patients with B
CLL after SCT. A durable anti-leukemic effect was probably important in these
patients.
PMID- 10673742
TI - A mutated PML/RARA found in the retinoid maturation resistant NB4 subclone, NB4
R2, blocks RARA and wild-type PML/RARA transcriptional activities.
AB - The fusion protein PML/RARA, associated with acute promyelocytic leukemia behaves
as an abnormal retinoic acid (RA) receptor with altered transactivation
properties but is still inducible by RA. The chimeric protein is thought to
promote leukemogenesis but also paradoxically to mediate the sensitivity to ATRA
of APL cells. This has been supported by works reporting that in vitro ATRA
resistance is characterized by defects in the RARA/E-domain of PML/RARA. In the
present report, we identified a new mutation in the E domain of PML/RARA which is
associated with a RA-resistant subline of NB4 cells; NB4-R2. This mutation,
identical to the Gln411 mutation found in HL60-R, changes the amino acid Gln903
to an in-phase stop codon, generating a truncated form of PML/RARA which has lost
52 amino acids at its C-terminal end. We have studied the effect of the truncated
PML/RARA protein on PML NB formation and RARA and PML/RARA transcriptional
activity. We show here that the fusion mutant exerts a dominant negative effect
on wild-type PML, PML/RARA and RARA transcription activity. These findings
highlight the important role of the RARA E-domain of PML/RARA in mediating RA
sensitivity in APL cells.
PMID- 10673743
TI - Arsenic trioxide-induced apoptosis and differentiation are associated
respectively with mitochondrial transmembrane potential collapse and retinoic
acid signaling pathways in acute promyelocytic leukemia.
AB - Recent studies showed that arsenic trioxide (As2O3) could induce apoptosis and
partial differentiation of leukemic promyelocytes. Here, we addressed the
possible mechanisms underlying these two different effects. 1.0 microM As2O3
induced apoptosis was associated with condensation of the mitochondrial matrix,
disruption of mitochondrial transmembrane potentials (DeltaPsim) and activation
of caspase-3 in acute promyelocytic leukemia (APL) cells regardless of their
sensitivity to all-trans retinoic acid (ATRA). All these effects were inhibited
by dithiothreitol (DTT) and enhanced by buthionine sulfoximine (BSO).
Furthermore, BSO could also render HL60 and U937 cells, which had the higher
cellular catalase activity, sensitive to As2O3-induced apoptosis. Surprisingly,
1.0 microM As2O3 did not induce the DeltaPsim collapse and apoptosis, while 0.1
microM As2O3 induced partial differentiation of fresh BM cells from a de novo APL
patient. In this study, we also showed that 0.2 mM DTT did not block low-dose
As2O3-induced NB4 cell differentiation, and 0. 10.5 microM As2O3 did not induce
differentiation of ATRA-resistant NB4-derived sublines, which were confirmed by
cytomorphology, expression of CD11b, CD33 and CD14 as well as NBT reduction.
Another interesting finding was that 0.10.5 microM As2O3 could also induce
differentiation-related changes in ATRA-sensitive HL60 cells. However, the
differentiation-inducing effect could not be seen in ATRA-resistant HL60 sublines
with RARalpha mutation. Moreover, low-dose As2O3 and ATRA yielded similar gene
expression profiles in APL cells. These results encouraged us to hypothesize that
As2O3 induces APL cell differentiation through direct or indirect activation of
retinoic acid receptor-related signaling pathway(s), while DeltaPsim collapse is
the common mechanism of As2O3-induced apoptosis.
PMID- 10673744
TI - Molecular profile of Epstein-Barr virus infection in HHV-8-positive primary
effusion lymphoma.
AB - Primary effusion lymphoma (PEL) selectively involves the serous body cavities,
occurs predominantly in immunodeficient patients and is infected consistently by
human herpesvirus type-8. PEL is also frequently infected by Epstein-Barr virus
(EBV). The precise pathogenetic role of EBV coinfection in PEL is not fully
understood. The lymphoma fails to express the EBV transforming proteins EBNA-2
and LMP-1, whereas it expresses EBNA-1 (latency I phenotype). Some studies have
hypothesized that other EBV-positive lymphomas expressing the latency I phenotype
may associate with specific molecular variants of EBNA-1, although this issue has
not been addressed in PEL. On this basis, this study is aimed at a detailed
molecular characterization of EBV in PEL. Fifteen EBV positive PEL (12 AIDS
related, one post-transplant, two arising in immunocompetent hosts) were
subjected to molecular characterization of the viral genes EBNA-1 and LMP-1, as
well as definition of EBV type-1/type-2. The EBNA-1 gene displayed a high degree
of heterogeneity in different cases of PEL, with seven distinct recognizable
variants and subvariants. A wild-type LMP-1 gene was detected in 10/15 cases,
whereas in 5/15 cases the LMP-1 gene harbored a deletion spanning codons 346-355.
EBV type-1 occurred in 11/15 PEL whereas EBV type-2 occurred in 4/15 cases.
Despite a high degree of genetic variability of the virus in different PEL cases,
each single PEL harbored only one EBV variant, consistent with monoclonality of
infection and suggesting that infection preceded clonal expansion. Overall, our
results indicate that: (1) individual PEL cases consistently harbor a single EBV
strain; (2) EBNA-1 displays a high degree of heterogeneity in different PEL
cases; (3) no specific EBV genotype preferentially associates with PEL.
PMID- 10673745
TI - Spontaneous reduction of leukemic lymphoma cells possibly by anti-tumor antibody
mediated phagocytosis; a kappa lambda-dual-positive B cell lymphoma.
AB - We have investigated the possible role of anti-tumor antibody detected in a case
of follicular lymphoma which demonstrated the spontaneous reduction of leukemic
tumor cells. The tumor cells genotypically had monoclonal rearrangements of the
immunoglobulin J H and C kappa genes, but phenotypically exhibited surface IgG,
A, kappa and lambda (kappa lambda dual positivity). The culture study revealed
that IgGlambda, at least, was derived from the serum, and IgAkappa was expressed
intrinsically. Furthermore, the positive correlation between the densities of
both surface light chains on two-color flow cytometry, the rosette formation
study and its inhibition test by the Fcgamma fragment suggested that the serum
IgGlambda combined with some antigens on the tumor-cell surface via its Fab
portion and with the Fcgamma receptor of macrophages via its Fc portion. From
these findings, we regarded the present case as an anti-tumor antibody-coated
lymphoma. In addition, the phagocytic study disclosed that the serum-derived
IgGlambda, at least, might have induced the phagocytosis of circulating lymphoma
cells by macrophages. In conclusion, the existence of the anti-tumor antibody
coated lymphoma may be helpful in clarifying the immunological mechanism of the
spontaneous regression occasionally seen in lymphomas.
PMID- 10673746
TI - The tyrosine kinase receptor met and its ligand HGF are co-expressed and
functionally active in HHV-8 positive primary effusion lymphoma.
AB - Primary effusion lymphoma (PEL) harbors consistent infection by human herpesvirus
8, preferentially develops in immunodeficient patients and selectively localizes
to the serous body cavities. Histogenetic analysis has suggested that PEL
originates from post-germinal center, pre-terminally differentiated B cells
sharing phenotypic features with plasma cells. Here we have investigated the
expression status and functional integrity of the Met tyrosine kinase receptor
and of its ligand hepatocyte growth factor (HGF). Thirteen PEL (nine cell lines
and four primary specimens) were analyzed for Met and HGF expression and function
by multiple assays. For comparison, a panel of 34 high grade B cell non-Hodgkin
lymphomas (NHL) other than PEL was also investigated. Co-expression of Met and
HGF was found in all PEL analyzed, whereas it was restricted to 1/34 B cell NHL
other than PEL (P < 0.001; chi2 test). The Met protein expressed by PEL displays
biochemical characteristics typical of Met expressed by other cell types and is
capable of tyrosine autophosphorylation. By using a combination of immunological
and biological assays, production and secretion of a functional HGF species was
identified in all PEL cell lines analyzed. HGF stimulation of PEL cells rapidly
induces Met tyrosine phosphorylation, demonstrating the functional integrity of
the Met/HGF loop. Because of the well known mitogenic and motogenic properties of
Met/HGF interactions, these data may bear implications for PEL growth and
dissemination. Among B cell neoplasms, Met/HGF co-expression selectively clusters
with PEL and, as demonstrated by previous studies, with multiple myeloma plasma
cells, thus reinforcing the notion that PEL displays biologic similarities with
tumors derived from late stages of B cell differentiation.
PMID- 10673747
TI - Proliferative response of mantle cell lymphoma cells stimulated by CD40 ligation
and IL-4.
AB - Mantle cell lymphoma (MCL) is a tumor of intermediate-size, IgM+, IgD+ B cells
derived from the mantle zone of the germinal center. Little is known about its
specific immunologic features or responsiveness to T cell-derived signals. In
this work, we evaluated the proliferation and cell cycle properties of freshly
isolated MCL cells after CD40 ligation, in the absence and presence of
interleukin 4 (IL-4). In each MCL case examined, there was a marked growth
enhancing effect of these two stimuli characterized by improved viability,
augmented expression of Ki-67, and induction of the proliferating cell nuclear
antigen (PCNA). Cyclin D1 was expressed throughout the cell cycle in MCL cells
induced to enter S phase. From these investigations, we conclude that the biology
of MCL B lymphocytes is affected by CD154 (CD40 ligand) and IL-4, two signals
usually provided by CD4+ T cells. The capacity to manipulate the activation and
cell cycle state of MCL cells by these specific immunological stimuli may be
exploited to confer susceptibility to chemotherapy agents and develop novel
therapies in this disease.
PMID- 10673748
TI - 2-Chloro-2'-deoxyadenosine induces apoptosis through the Fas/Fas ligand pathway
in human leukemia cell line MOLT-4.
AB - The mechanism of apoptosis induced by 2-chloro-2'-deoxyadenosine (2CdA) in human
leukemia cell line MOLT-4 was investigated. 2CdA induced increases of 3'-OH ends
of genomic DNA, ladder-like DNA fragmentation and phosphatidylserine
translocation to the outer membrane, which are apoptotic characteristics. These
apoptotic phenomena induced by 2CdA were inhibited by cycloheximide (CHX; a
protein synthesis inhibitor), deoxycytidine (dC; a substrate of deoxycytidine
kinase), acetyl Ile-Glu-Thr-Asp aldehyde (Ac-IETD-CHO; a caspase-8 inhibitor) and
acetyl Asp-Glu-Val-Asp aldehyde (Ac-DEVD-CHO; a caspase-3 inhibitor). The protein
synthesis-dependent expression of Fas and Fas ligand (Fas-L) was detected by
treatment with 2CdA. The proteolytic processing of procaspases-8 and -3 to
produce active fragments, caspases-8 (p18) and -3 (p17), respectively, was
observed after treatment with 2CdA, and suppressed by cycloheximide. Increases in
the activities of caspases-8 and -3 were observed after 2CdA treatment. Their
activation was also dependent on protein synthesis. These results indicated that
2CdA-induced apoptosis was triggered by phosphorylation of 2CdA followed by the
protein synthesis-dependent expression of Fas and Fas-L and activation of
caspases-8 and -3.
PMID- 10673749
TI - Improved retroviral transduction of hematopoietic progenitors by combining
methods to enhance virus-cell interaction.
AB - One of the factors required for successful retroviral transduction is contact
between viral particles and target cells. We hypothesized that combining agents
that improve virus-target cell interaction via different mechanisms will increase
transduction efficiency. We examined the transduction efficiency of leukemic K562
cells, primary normal and chronic myelogenous leukemia CD34+ cells with the
amphotropic retroviral vector, G1Na, packaged in PA317 by enumerating G418
resistant colonies in semisolid media. We evaluated the ability of the
recombinant fibronectin fragment, CH296, cationic lipids, or a transwell flow
through system, alone or in combination to improve retroviral transduction.
Transduction of K562 cells improved 1.5 to two-fold with lipids or CH296, while
their combination improved transduction 2.5-fold. Transduction of K562 cells in
the transwell flow-through system improved transduction three-fold. Transduction
of normal (NL) CD34+ CFC improved 10-fold with lipids and 20-fold with CH296.
Lipid and CH296 had synergistic effects. The transwell flow-through system
improved transduction of normal CD34+ CFC 30-fold. Finally, similar to what was
seen for K562 cells, transduction of CML CFC improved two- to three-fold with
either CH296 or lipids, whereas the combination had synergistic effects. We
conclude that any physical means that enhances contact between viral particles
and target cells improves transduction. Two such methods that have different
action mechanisms have additive or synergistic effects on transduction.
PMID- 10673750
TI - Rapid and reliable detection of N-ras mutations in acute lymphoblastic leukemia
by melting curve analysis using LightCycler technology.
AB - We applied a new strategy for the detection of N-ras gene mutations based on
LightCycler technology. We designed two sets of amplimers and internal
hybridization probes representing N-ras codons 12/13 and codon 61, respectively.
Genomic DNAs from 134 childhood acute lymphoblastic leukemia (ALL) patients (83
common ALL, nine pre-pre-B ALL, 19 pre-B ALL, 23 T-ALL) were amplified, followed
by the analysis of the melting temperatures of the PCR products on the
LightCycler. PCR products exhibiting an abnormal melting characteristic were
directly sequenced. Sequence analyses unravelled nucleotide substitutions at
codon 12 in 10 patients, at codon 13 in three, and at codon 61 in one case. The
incidence of N-rasmutations (10%) is compatible with previous reports. The
LightCycler technology facilitates the rapid analysis of other genes exhibiting
hot spot mutations in human malignancies.
PMID- 10673751
TI - Potential of LightCycler technology for quantification of minimal residual
disease in childhood acute lymphoblastic leukemia.
AB - A certain quantity of residual leukemic cells at several time points during
chemotherapy of childhood acute lymphoblastic leukemia (ALL) was proved to
predict outcome. Future childhood ALL treatment will take minimal residual
disease (MRD) into consideration for stratification aiming at an
individualization of chemotherapeutic regimens. Recently, the first quantitative
real-time PCR assay for MRD detection was described using T cell receptor and
immunoglobulin gene rearrangements as clonal markers. Quantitative real-time PCR
was performed with TaqMan technology. Here, we present for the first time the
potential of LightCycler real-time PCR technology to quantify MRD. We compare and
assess different approaches for real-time PCR quantification of leukemic cells,
based either on clone-specific primers and general fluorescence detection with
SYBR Green, TaqMan probe or hybridization probes, or based on general PCR
amplification and clone-specific detection with hybridization probes. MRD
quantification with LightCycler real-time PCR technology is a sensitive, specific
and incomparably rapid method that needs no post-PCR handling, hence eliminating
contamination risk and saving time. Working towards the establishment of MRD
quantification in routine diagnostics and towards treatment strategies based on
these results, LightCycler quantitative PCR seems to be a promising new technique
that makes results immediately available for treatment decisions.
PMID- 10673752
TI - Quantitation of minimal residual disease in acute promyelocytic leukemia patients
with t(15;17) translocation using real-time RT-PCR.
AB - We took advantage of a recently developed system allowing performance of real
time quantitation of polymerase chain reaction to develop a quantitative method
of measurement of PML-RARalpha transcripts which are hallmarks of acute
promyelocytic leukemia (APL) with t(15;17) translocation. Indeed, although
quantitation of minimal residual disease has proved to be useful in predicting
clinical outcome in other leukemias such as chronic myeloid leukemia or acute
lymphoblastic leukemia, no quantitative data have been provided in the case of
APL. We present here a method for quantitation of the most frequent subtypes of
t(15;17) transcripts (namely bcr1 and bcr3). One specific forward primer is used
for each subtype in order to keep amplicon length under 200 bp. The expression of
PML-RARalpha transcripts is normalized using the housekeeping porphobilinogen
deaminase (PBGD) gene. This technique allows detection of 10 copies of PML
RARalpha or PBGD plasmids, and quantitation was efficient up to 100 copies. One
t(15;17)-positive NB4 cell could be detected among 106 HL60 cells, although
quantitation was efficient up to one cell among 105. Repeatability and
reproducibility of the method were satisfying as intra- and inter-assay variation
coefficients were not higher than 15%. The efficiency of the method was finally
tested in patient samples, showing a decrease of the PML-RARalpha copy number
during therapy, and an increase at the time of relapse.
PMID- 10673753
TI - Comparison of nested competitive RT-PCR and real-time RT-PCR for the detection
and quantification of AML1/MTG8 fusion transcripts in t(8;21) positive acute
myelogenous leukemia.
AB - The chromosomal translocation t(8;21)(q22;q22) is one of the most frequent
karyotypic aberrations in acute myeloid leukemia (AML) and results in a chimeric
fusion transcript AML1/MTG8. Since AML1/MTG8 fusion transcripts remain detectable
by RT-PCR in t(8;21) AML patients in long-term hematological remission,
quantitative assessment of AML1/MTG8 transcripts is necessary for the monitoring
of minimal residual disease (MRD) in these patients. Competitive RT-PCR and
recently real-time RT-PCR are increasingly used for detection and quantification
of leukemia specific fusion transcripts. For the direct comparison of both
methods we cloned a 42 bp DNA fragment into the original AML1/MTG8 sequence. The
resulting molecule was used as an internal competitor for our novel competitive
nested RT-PCR for AML1/MTG8 and as an external standard for the generation of
AML1/MTG8 standard curves in a real-time PCR assay. Using this standard molecule
for both PCR techniques, we compared their sensitivity, linearity and
reproducibility. Both methods were comparable with regard to all parameters
tested irrespective of analyzing serial dilutions of plasmids, cell lines or
samples from t(8;21) positive AML patients at different stages of the disease.
Therefore, both techniques can be recommended for the monitoring of MRD in these
particular AML patients. However, the automatization of the real-time PCR
technique offers some technical advantages.
PMID- 10673754
TI - Simple methods for the rapid exchange of flow cytometric data between remote
centers.
PMID- 10673755
TI - Granulocyte colony-stimulating factor receptor expression and 11q23/MLL genotype
in childhood acute lymphoblastic leukemia developing during the first 18 months
of life.
PMID- 10673756
TI - Flow cytometric detection of B cell abnormal maturation in chronic myeloid
leukemia.
PMID- 10673758
TI - Pseudotumor cerebri after treatment of relapsed acute promyelocytic leukemia with
arsenic trioxide.
PMID- 10673757
TI - 3 x 14 mg/m2 idarubicin during induction: results of a pilot study in children
with AML.
PMID- 10673759
TI - Good response to cyclosporine therapy in patients with myelodysplastic syndromes
having the HLA-DRB1*1501 allele.
PMID- 10673760
TI - Molecular psychiatry at the millennium.
PMID- 10673762
TI - News in brief
PMID- 10673761
TI - Comparative proteome analysis. Tissue homogenate from normal human hippocampus
subjected to two-dimensional gel electrophoresis and Coomassie blue protein
staining.
PMID- 10673763
TI - Beware the chopsticks gene.
AB - Population stratification is a potential source of error in psychiatric genetics.
New study designs and statistical methods can help guard against this problem.
Molecular Psychiatry (2000) 5, 11-13.
PMID- 10673764
TI - The role of stress in the pathophysiology of the dopaminergic system.
AB - In this review, we will examine the most recent preclinical evidence in support
of the fact that both acute and chronic stress may have a detrimental impact on
the normal function of the dopaminergic system. In recent decades, the term
stress has changed its meaning from that of a 'non-specific body response' to a
'monitoring system of internal and external cues'; that is a modality of reaction
of the mammalian central nervous system (CNS) which is critical to the adaptation
of the organism to its environment. Compelling results have demonstrated that the
dopaminergic system is important not only for hedonic impact or reward learning
but also, in a broader sense, for reactivity to perturbation in environmental
conditions, for selective information processing, and for general emotional
responses, which are essential functions in the ability (or failure) to cope with
the external world. In this, stress directly influences several basic behaviors
which are mediated by the dopaminergic system such as locomotor activity, sexual
activity, appetite, and cross sensitization with drugs of abuse. Studies using
rat lines which are genetically different in dopamine (DA) physiology, have shown
that even small alterations in the birth procedure or early life stress events
may contribute to the pathophysiology of psychiatric disorders-in particular
those involving central DA dysfunction-and may cause depression or psychotic
derangement in the offspring. Finally, the fact that the dopaminergic system
after stress responds, preferentially, in the medial prefrontal cortex (MFC), is
thought to serve, in humans, as a protection against positive psychotic symptoms,
since the increased DA activity in the MFC suppresses limbic DA transmission.
However, excessive MFC dopaminergic activity has a negative impact on the
cognitive functions of primates, making them unable to select and process
significant environmental stimuli. Thus it appears that a critical range of DA
turnover is necessary for optimal cognitive functioning after stress, in the
response of the CNS to ever-changing environmental demands. Molecular Psychiatry
(2000) 5, 14-21.
PMID- 10673765
TI - Psychiatric genetics: back to the future.
AB - For the last decade or more geneticists have been predicting that advances in
molecular genetics are going to revolutionize our understanding of psychiatric
disorders and human behavior. However, with a few exceptions, these expectations
have yet to be fulfilled. As the century draws to a close and we contemplate the
prospect of the complete sequence of the human genome it seems timely to consider
the state of the field and to consider carefully how it might advance, the
problems to be faced and the resources required. Molecular Psychiatry (2000) 5,
22-31.
PMID- 10673766
TI - The human serotonin transporter gene linked polymorphism (5-HTTLPR) shows ten
novel allelic variants.
AB - The serotonin transporter (5-HTT) gene is a promising candidate for introducing
the heritability of interindividual variation in personality and the genetic
susceptibility for various psychiatric diseases. Transcription of the gene is
modulated by a common polymorphism in its upstream regulatory region (5-HTT gene
linked polymorphic region: 5-HTTLPR). The 5-HTTLPR consists of variation of the
repetitive sequence containing GC-rich, 20-23-bp-long repeat elements. A
deletion/insertion in the 5-HTTLPR was first reported to create a short (S)
allele and a long (L) allele (14- and 16-repeats, respectively). Three other
kinds of alleles (18-, 19- and 20-repeats) in addition to the S and L alleles in
5-HTTLPR have been reported. In the present study, we examined the 5-HTTLPR
polymorphism in detail and identified ten novel sequence variants, concluding
that the alleles reported as S and L are divided into four and six kinds of
allelic variant, respectively. Subsequently, we developed a method for
genotyping. The total number of alleles (14-A, 14-B, 14-C, 14-D, 15, 16-A, 16-B,
16-C, 16-D, 16-E, 16-F, 19, 20 and 22) in the 5-HTTLPR was 14 in our populations
(Japanese: n = 131; Caucasian: n = 74) in the present study. In addition, a
significant ethnic difference between Japanese and Caucasian populations was
observed for distributions of alleles and genotypes (P < 0.0001 and P < 0.0001,
respectively). Our results suggest that the analyses of the 5-HTTLPR should be
revised by genotyping with a more complete subdivision of alleles. Molecular
Psychiatry (2000) 5, 32-38.
PMID- 10673767
TI - Dopamine induces a biphasic modulation of hypothalamic ANF neurons: a ligand
concentration-dependent effect involving D5 and D2 receptor interaction.
AB - Increasing evidence now suggests that more than one subtype of dopamine receptors
is co-expressed in some of the central neurons. The neurobiological effects on
the host cells when these receptors are concurrently activated by their common
physiological ligand, dopamine, however, remains elusive. Among the members of
the family of dopamine receptors, coupling of D1-like dopamine receptors to Gs
and D2-like receptors to Gi proteins are known to augment or suppress cellular
functions respectively, through modulation of adenylyl cyclase activity and
consequently cAMP generation. Simultaneous activation of D1 and D2 receptors in
transfected cell lines expressing the two cloned receptors, however, produced
antagonistic effects. This is in contrast to in vivo studies, in which concurrent
activation of D1-like and D2-like receptors by their respective agonists may
induce synergistic or antagonistic effects or both. We report here that in long
term rat hypothalamic cell cultures, activation of both D1-like (D1 and D5) and
D2 receptors on atrial natriuretic factor-producing neurons by dopamine yields a
biphasic response. The response is ligand concentration-dependent and involves
type II adenylyl cyclases. This process is mediated primarily through
antagonistic and synergistic interactions of D5 and D2 receptors as the event is
mimicked by the concurrent activation of these two receptors co-transfected in
CHO cells. Our present findings suggest a novel action of dopamine, and the
biochemical processes involved may underlie some of the pharmacological actions
of atypical anti-psychotic drugs. Molecular Psychiatry (2000) 5, 39-48.
PMID- 10673768
TI - Identification and analysis of new sequence variants in the human tryptophan
hydroxylase (TpH) gene.
AB - The tryptophan hydroxylase (TpH) gene codes for the rate-limiting enzyme in
serotonin biosynthesis. It is one of the major candidate genes for psychiatric
and behavioral disorders. A polymorphism in TpH intron 7 has been shown to be
associated with suicidal attempts, aggressive behavior and psychiatric illnesses.
By systematically screening the TpH genomic sequence, we identified and confirmed
an earlier report of four variants in the promoter region and localized six new
sequence variants, ie two in intron 1b, one in exon 1c, one in intron 8, one in
intron 9 and a microsatellite in the 3' region, 5687 bp downstream of the last
exon 11. We analyzed these polymorphisms, as well as the one in intron 7, by
Single Strand Conformation Analysis, microsatellite or restriction analysis in a
collection of 175 West European Caucasian healthy subjects. The four variants in
the promoter region are in complete linkage disequilibrium (frequencies of G-T-G
T and T-C-A-G haplotypes are 0. 41 and 0.59, respectively). Deletion of GTT in
intron 1b is rare (0. 7%) and so not informative. The rarer allele T of intron 1b
polymorphism T3792A has a frequency of 0.34 and is in partial linkage
disequilibrium with the more common alleles of intron 7, 8 and 9. The
polymorphisms of these three introns are in complete linkage disequilibrium and
the frequencies of haplotypes A-T-C and C-C-T are 0.36 and 0.64 respectively. We
detected 10 different alleles in the microsatellite localized in the 3' region;
allele '194' is in partial linkage disequilibrium with haplotype A-T-C of introns
7, 8, and 9. Analysis of these different polymorphisms will constitute an
important tool for future studies between the TpH gene and psychiatric disorders.
Molecular Psychiatry (2000) 5, 49-55.
PMID- 10673769
TI - A haplotype at the DBH locus, associated with low plasma dopamine beta
hydroxylase activity, also associates with cocaine-induced paranoia.
AB - Low levels of dopamine beta-hydroxylase (DbetaH) protein in the plasma or
cerebrospinal fluid (CSF) are associated with greater vulnerability to positive
psychotic symptoms in several psychiatric disorders. DbetaH level is a stable,
genetically controlled trait. DBH, the locus encoding DbetaH protein, is the
major quantitative trait locus controlling plasma and CSF DbetaH levels. We
therefore hypothesized that DBH variants or haplotypes, associated with low
levels of DbetaH in the plasma, would also associate with greater vulnerability
to cocaine-induced paranoia. To test this hypothesis, we first showed that a di
allelic variant, DBH*5'-ins/del, located approximately 3 kb 5' to the DBH
transcriptional start site, significantly associates with plasma DbetaH activity
in European-Americans (n = 66). Linkage disequilibrium analysis of that
polymorphism and DBH*444g/a, another di-allelic variant associated with DbetaH
levels, demonstrated that alleles of similar association to DbetaH levels are in
positive disequilibrium. We then estimated DBH haplotype frequencies in cocaine
dependent European Americans rated for cocaine-induced paranoia (n = 45). As
predicted, the low-DbetaH-associated haplotype, Del-a, was significantly more
frequent (P = 0.0003) in subjects endorsing cocaine-induced paranoia (n = 29)
than in those denying it (n = 16). Comparison to control haplotype frequencies (n
= 145 healthy European-Americans) showed that the association predominantly
reflected under-representation of Del-a haplotypes in those denying cocaine
induced paranoia. We conclude that: (a) the two DBH polymorphisms we studied are
associated with plasma DBH levels; (b) those two polymorphisms are in significant
linkage disequilibrium in European Americans, with alleles of similar association
to DbetaH levels in positive disequilibrium; and (c) the haplotype associated
with low DBH activity is also associated with cocaine-induced paranoia. Molecular
Psychiatry (2000) 5, 56-63.
PMID- 10673770
TI - Identification of a polymorphism in the promoter region of DRD4 associated with
the human novelty seeking personality trait.
AB - Polymorphism in the human dopamine D4 receptor gene (DRD4) exon III has been
associated in some but not all studies of the human personality trait of Novelty
Seeking. We searched for polymorphisms in the 5' region of DRD4 and identified
six polymorphisms as follows: -1217G Ins/Del, -809G/A, -616C/G, -603T Ins/Del,
602(G)8-9, and -521C/T. Associations between these polymorphisms and personality
traits measured by the Temperament and Character Inventory (TCI) were
investigated in 86 healthy Japanese volunteers. The -521C/T polymorphism was
significantly associated with Novelty Seeking (P = 0.0001). Subjects with the C/C
genotype exhibited the highest Novelty Seeking scores and those with the T/T
genotype exhibited the lowest. A transient expression method revealed that the T
variant of the C-521T polymorphism reduces transcriptional efficiency. The
present study suggests a contribution of dopamine D4 receptor availability to
individual differences in Novelty Seeking behavior. Molecular Psychiatry (2000)
5, 64-69.
PMID- 10673771
TI - Antipsychotic drug-induced obesity in rats: correlation between leptin, insulin
and body weight during sulpiride treatment.
AB - Sulpiride (SUL, 20 mg kg-1 day-1) induces weight gain, hyperphagia,
hyperprolactinemia, hypogonadism, and perhaps increased insulin sensitivity in
rats. Leptin seems to signal the brain about the size of body fat stores and
nutrient metabolism. We evaluated the basal serum leptin levels in rats after
acute (1 h) or prolonged SUL or vehicle administration (10, 20 and 30 days). At
days 10 and 30 leptin was also assessed during a glucose overload test. As the
maximal weight gain during SUL administration is observed at days 10-15 of
treatment, leptin was measured in a comparison group of insulin-treated rats (5
IU day-1 for 10 days). SUL-treated rats significantly gained weight. However,
leptin levels were not significantly increased at any time-point of treatment.
SUL did not affect insulin levels either. By contrast, leptin levels were
significantly elevated after insulin administration, along with weight gain and
hyperinsulinemia. An opposite correlation was also observed at day 10: leptin and
insulin correlated negatively in the SUL group and positively in the insulin
group. In addition, leptin and the magnitude of weight gain tended to correlate
positively after SUL treatment, but negatively after insulin administration. SUL
treated rats, thus, appear to exhibit an unusual type of weight gain,
characterized by normal circulating leptin and insulin levels. Such a particular
leptin profile may be related to hyperprolactinemia, hypogonadism or lack of
hyperinsulinemia. Molecular Psychiatry (2000) 5, 70-76.
PMID- 10673772
TI - Family-based linkage disequilibrium mapping using SNP marker haplotypes:
application to a potential locus for schizophrenia at chromosome 22q11.
AB - Family-based linkage disequilibrium mapping using SNP markers is expected to be a
major route to the identification of susceptibility alleles for complex diseases.
However there are a number of methodological issues yet to be resolved, including
the handling of extended haplotype data and analysis of haplotype transmission in
sib-pair or family trio samples. In the present study, we have analysed two
dinucleotide repeat and six SNP markers at the COMT locus at chromosome 22q11, a
region implicated in psychosis, for transmission distortion in 198 Chinese
schizophrenic family trios. When individual markers were analysed using the TDT,
two showed modest evidence of transmission distortion (186C/T, P = 0.04;
Val158Met, P = 0.01). Using haplotypes of paired markers analysed by the program
TRANSMIT, the most significant P value was 0.001, for the Met158Val and
900ins/delC polymorphisms in the COMT gene. The global P value for the haplotypes
of all six SNP markers tested was 0.004, largely a result of the excess
transmission of two extended haplotypes which differed at the marker 408C/G. The
exclusion of this marker from the analysis gave a global P value of 0.002 and
produced a five marker haplotype system which was significant at P = 0.0006. This
haplotype consisted of the alleles -287G:186C:Val158:900insC:ARVCF930C, which may
represent a background haplotype for the transmission of a schizophrenia
susceptibility allele at chromosome 22q11. Our results support the hypotheses
that either COMT is itself a susceptibility gene, or more likely that this region
of chromosome 22 contains a susceptibility gene that is in linkage disequilibrium
with COMT alleles. Molecular Psychiatry (2000) 5, 77-84.
PMID- 10673773
TI - Comparative proteome analysis of the hippocampus implicates chromosome 6q in
schizophrenia.
AB - Comparative brain proteome analysis is a new strategy to discover proteins and
therefore genes whose altered expression may underlie schizophrenia. This
strategy does not require an a priori theory of the pathogenesis or the mode of
inheritance of schizophrenia. Using proteome analysis we previously compared the
hippocampal proteome, that is, those proteins expressed by the hippocampal
genome, of seven schizophrenic individuals with the hippocampal proteome of seven
control individuals, matched for age and post mortem delay.1 We found 18 proteins
that were significantly altered in concentration in the schizophrenic hippocampus
(P < 0.05), when compared to control tissue. One of these proteins was
characterised, by N-terminal sequencing, as diazepam binding inhibitor whose gene
maps to 6q12-q21. Here we characterise a further three of the 18 proteins as:
manganese superoxide dismutase, 6q25.3, T-complex protein 1, 6q25.3-q26 and
collapsin response mediator protein 2, 8p21. That three of these four
characterised proteins should map to the long arm of the same chromosome is
significant (P < 0.002) and suggests the importance of chromosome 6q in
schizophrenia. These results indicate that antioxidant defence is altered in the
schizophrenic hippocampus and suggest that segregation distortion, of
schizophrenia susceptibility genes, may be a possible causative factor in the
high incidence of schizophrenia. Molecular Psychiatry (2000) 5, 85-90.
PMID- 10673774
TI - Serotonin transporter gene and schizophrenia: evidence for association/linkage
disequilibrium in families with affected siblings.
AB - The serotonergic (5-HT) system has been implicated in the etiopathogenesis of
psychoses. Since the 5-HT transporter plays an important role in regulation of 5
HT transmission, its gene can be considered as a candidate for vulnerability to
psychiatric disorders. Two polymorphic sites of the 5-HT transporter gene-5
HTTLPR, a VNTR in the 5' regulatory region, and a VNTR in the second intron-were
studied in a sample of 61 families with schizophrenia for transmission
disequilibrium. Each family contained at least two siblings affected with
schizophrenia or schizoaffective disorder (mainly schizophrenic). One hundred and
thirty-nine affected offspring with parental information for genotyping, were
available for analysis. No preferential transmission of either short or long
alleles of the promoter polymorphism was observed. However, a transmission
distortion was detected for alleles of the intronic VNTR polymorphism (chi2TDT
max =14.33; P = 0.0002; corrected P value = 0.0003) resulting in more frequent
than expected transmission of the 12 repeat allele. This finding adds additional
evidence to the idea that the serotonergic system may be involved in development
of psychoses. Molecular Psychiatry (2000) 5, 91-95.
PMID- 10673775
TI - Association between tridimensional personality questionnaire (TPQ) traits and
three functional polymorphisms: dopamine receptor D4 (DRD4), serotonin
transporter promoter region (5-HTTLPR) and catechol O-methyltransferase (COMT).
AB - Dopamine D4 receptor (DRD4), serotonin transporter promoter regulatory region (5
HTTLPR) and catechol O-methyltransferase (COMT) polymorphisms were examined for
association with TPQ personality factors in 455 subjects. Significant
interactions were observed by multivariate analysis, (COMT x 5-HTTLPR:
Hotelling's Trace = 2.3, P = 0.02) and by subsequent univariate 3-way ANOVA when
Novelty Seeking (NS) was the dependent variable: 5-HTTLPR x D4DR (F = 6.18, P =
0.03) and COMT x 5-HTTLPR (F = 4.42, P = 0.03). In the absence of the short 5
HTTLPR allele and in the presence of the high enzyme activity COMT val/val
genotype, NS scores are higher in the presence of the DRD4 seven-repeat allele.
The effect of these three polymorphisms on NS was also examined using a within
families design. Siblings who shared identical genotype groups for all three
polymorphisms (COMT, DRD4 and 5-HTTLPR) had significantly correlated NS scores
(intraclass coefficient = 0.39, F = 2.26, P = 0.008, n = 49) whereas sibs with
dissimilar genotypes in at least one polymorphism showed no significant
correlation for NS scores (intraclass coefficient = 0.177, F = 1.43, P = 0.09, n
= 110). Similar interactions were also observed between these three polymorphisms
and Novelty Seeking when the 150 independently recruited and non-related subjects
were analyzed. The current results are consistent with two earlier reports in
which we demonstrated an interaction between the 5-HTTLPR and DRD4 polymorphisms
in 2-week-old neonates, in the same children assessed again at 2 months of age
and in adults. Molecular Psychiatry (2000) 5, 96-100.
PMID- 10673777
TI - Pathological gambling and DNA polymorphic markers at MAO-A and MAO-B genes.
AB - This study was conducted to detect a possible association of MAOA and/or MAOB
genes with pathological gambling (PG). DNA polymorphisms in MAOA and MAOB genes
were screened by molecular analysis in 68 individuals (47 males and 21 females)
meeting ICD-10 and DSM-IV criteria for pathological gambling and 68 healthy
comparison controls matched for age and sex. There were no significant
differences between pathological gamblers and healthy volunteers in overall
allele distribution at the MAOA gene polymorphism. However there was a
significant association between allele distribution and the subgroup of severe
male gamblers (n = 31) compared to the males in the group of healthy volunteers
(chi2 = 5246; df = 1; P < 0.05 [Bonferroni corrected]). No association was found
between the MAOB polymorphic marker and PG. Allele variants at the MAOA, but not
the MAOB gene may be a genetic liability factor in PG, at least in severe male
gamblers. Molecular Psychiatry(2000) 5, 105-109.
PMID- 10673776
TI - DRD4 exon III VNTR polymorphism-susceptibility factor for heroin dependence?
Results of a case-control and a family-based association approach.
AB - Dopaminergic abnormalities are implicated in the pathogenesis of substance
abuse.1 Recently, two reports have been published suggesting an association
between opioid dependence and presence of long alleles of the dopamine D4
receptor (DRD4) gene exon III VNTR.2, 3 We have attempted to replicate this
finding using a two-tiered strategy employing independent case-control and family
based association samples. Our study was possibly the largest candidate gene
association study to date on opioid dependence in a sample of 815 subjects, 396
of whom were patients. We found long alleles of the DRD4 exon III VNTR in similar
frequency among 285 heroin addicts and 197 controls. Furthermore, no preferential
transmission of long alleles to affected offspring was observed in a sample of
111 patients and their parents. Our results, therefore, do not support the
hypothesis that alleles of the DRD4 exon III VNTR are susceptibility factors for
opioid dependence in man. Molecular Psychiatry(2000) 5, 101-104.
PMID- 10673779
TI - Volume 6 and the new millennium.
PMID- 10673778
TI - Modified structure of the human serotonin transporter promoter.
AB - Recently, several studies have reported an association between anxiety traits,
affective disorders and autism and alleles of a functional promoter polymorphism
(5HTT-LPR) in the human serotonin transporter (5HTT, SERT).1-3 The mechanistic
basis for allelic differences in transporter transcription are presently unknown.
To explore this issue, we cloned the human 5HTT promoter region from a PAC
genomic library and now describe an unreported 381-bp insert between the
polymorphic region and the transcription start site. We verified the presence of
this novel sequence by Southern hybridization of genomic digests and PCR
amplifications from multiple unrelated individuals. Sequence analysis of the
novel region reveals a number of canonical transcription factor binding sites (eg
AP1, Elk1, NFkappaB) that may be important in controlling the response of the
5HTT gene to regulatory factors. PCR studies of genomic templates reveal a low
level of amplification of a deleted template matching the size of the originally
reported 5HTT promoter. This deleted template is absent from PAC amplifications,
suggesting that the human 5HTT promoter may exhibit in vivo instability.
Molecular Psychiatry (2000) 5, 110-115.
PMID- 10673780
TI - Publisher's announcement.
PMID- 10673781
TI - Isolation and identification of Candida from the oral cavity.
AB - A number of methods of sampling the oral cavity for the presence of candida have
been developed. Such techniques play an important role in the diagnosis and
management of oral candidosis. In the past, identification of candida isolated
from the oral cavity has usually been limited to the genus Candida or to the
species C. albicans. However, with the recognition that Candida species differ in
the production of putative virulence factors and sensitivity to antifungal
agents, greater emphasis has been placed on identification of isolates to species
level. As a result a range of commercially available systems for yeast
identification can now be used in conjunction with traditional identification
procedures.
PMID- 10673782
TI - Influence of (S)-ketoprofen and fluoride on caries in rats.
AB - OBJECTIVE: Non-steroidal anti-inflammatory agents (e.g., ketoprofen) used
topically appear to be effective in reducing bone loss in the ligature model of
periodontitis. Ketoprofen, in common with some food preservatives, e.g., benzoate
and sorbate, is a weak acid. Fluoride, too, may behave as a weak acid and,
similar to the other agents, may exert antibacterial effects. The purpose of the
present study was to determine whether a combination of (S)-ketoprofen, an
enantiomer of ketoprofen, alone or in combination with fluoride, would suppress
Streptococcus sobrinus populations and reduce the incidence of dental caries in
rats. MATERIALS AND METHODS: Toothpastes containing ketoprofen and/or
monofluorophosphate were applied to the teeth of six groups of 20 rats twice
daily for 5 weeks. RESULTS: Fewest S. sobrinus were found in the group treated
with a paste containing 3% (S)-ketoprofen + 0.1% F. This group also displayed the
lowest incidence of smooth surface caries of all groups. Severity of sulcal
surface caries was also lowest in this group. CONCLUSIONS: Results from this
study show that the (S) enantiomer of ketoprofen enhances the caries protective
effect of fluoride. It is conceivable that this combination could be effective in
combating the two most common maladies of the mouth; periodontal disease and
dental caries.
PMID- 10673783
TI - Long-term follow-up of patients treated with acupuncture for xerostomia and the
influence of additional treatment.
AB - OBJECTIVE: To determine the long-term effects of acupuncture in patients with
xerostomia of different etiologies and the influence of additional treatment.
DESIGN: Retrospective study. SUBJECTS: Seventy patients, between the ages of 33
and 82, with xerostomia due to primary and secondary Sjogren's syndrome,
irradiation and other causes were included. The median duration of xerostomia was
32 months. METHODS: Salivary flow rates (SFR) for whole unstimulated and
stimulated saliva were used as indicators of effects of treatment. Data from
67/70 patients were analyzed 6 months following a baseline course of 24
acupuncture treatments using two-way ANOVA. Patients data up to 3 years were also
compared by those who chose to receive additional acupuncture treatment vs those
who did not. These data were analyzed descriptively. RESULTS: Statistically
significant differences in unstimulated and stimulated salivary flow rates (P <
0.01) were found in all etiological groups after 24 acupuncture treatments and up
to 6 months follow-up compared to baseline. Three years observation of these
patients showed that patients receiving additional acupuncture treatment had a
consistently higher median SFR in both unstimulated and stimulated saliva
compared to patients who chose not to continue acupuncture. The upper limits of
the interquartile range were also higher. CONCLUSIONS: This study shows that
acupuncture treatment results in statistically significant improvements in SFR in
patients with xerostomia up to 6 months. It suggests that additional acupuncture
therapy can maintain this improvement in SFR for up to 3 years.
PMID- 10673784
TI - Oral tuberculosis: a clinical evaluation of 42 cases.
AB - OBJECTIVES: A retrospective review of a large series of oro-facial cases of
tuberculosis to analyse clinical, histopathological, and radiological aspects, as
well as those of chemotherapy. MATERIALS AND METHODS: A total of 42 cases of
tuberculosis of the oro-facial region were examined. Thirteen patients had a
primary form and 29 a secondary form of the disease. Diagnosis was based on
careful clinical examination, Mantoux reaction, histopathological examination,
microbiological cultures and immunological investigation with the detection of
antibodies against Mycobacteria in the patients' serum (ELISA). RESULTS: Cases
examined consisted of 27 males and 15 females. The age range was 3 to 73 years
(mean age 31 years). Clinical manifestations comprised oral ulcers in 69.1%, bone
involvement in 21.4%, and salivary gland and/or lymph node involvement in 14.3%.
A total of 79.4% patients with secondary disease had pulmonary lesions, 15 of
whom showed clinical and radiological signs of activity; there was one case of
bilateral renal lesions and two of skin lesions. CONCLUSIONS: Oro-facial
tuberculosis is often difficult to diagnose and it should be an important
consideration in the differential diagnosis of lesions that appear in the oral
cavity. The most important diagnostic tools remain a careful clinical evaluation,
biopsy for histologic study, as well as acid-fast stains, culture, and
immunological assays, and skin testing.
PMID- 10673785
TI - Immunohistochemical detection of insulin-like growth factor-I in the labial
salivary glands of patients with Sjogren's syndrome.
AB - OBJECTIVE: The purpose of the present study was to investigate the presence of
insulin-like growth factor-I (IGF-I) in the labial salivary glands of patients
with Sjogren's syndrome and healthy controls and to determine if there are any
differences between these two groups. DESIGN: An immunohistochemical study.
SUBJECTS AND METHODS: Twenty-five patients with Sjogren's syndrome, 20 healthy
controls and 20 patients with mucoceles of the lip were used in this study. All
individuals underwent a systemic evaluation and a lip biopsy. Sections from the
lip biopsies were stained with haematoxylin and eosin (H&E). Immunohistochemical
staining was also performed using a three-step indirect immunoperoxidase for IGF
I. RESULTS: The light microscopic examination revealed the presence of a
mononuclear infiltration in the labial salivary glands of patients with Sjogren's
syndrome. Most of the infiltrates were lymphocytes. Immunohistochemically an
intense staining result was apparent in the same group. In contrast sections of
labial salivary glands of healthy individuals and of patients with mucoceles
revealed very weak staining. CONCLUSIONS: The above findings and the fact that
both lymphocytic infiltration and IGF-I were predominantly seen in ductal
regions, suggest that IGF-I may be a target of autoimmunity in Sjogren's
syndrome.
PMID- 10673786
TI - Evaluation of p53, PCNA, Ki-67, MDM2 and AgNOR in oral peripheral and central
giant cell lesions.
AB - OBJECTIVES: Peripheral giant cell lesion (PGCL) and central giant cell lesion
(CGCL) of the jaws have a distinct clinical behaviour. Whether such biological
differences are supported by a distinct pattern of proliferation markers or cell
cycle associated proteins expression is not known. Therefore the purpose of the
present study was to compare the immunohistochemical expression of p53, MDM2, Ki
67, PCNA and the histochemical expression of argyrophilic nuclear organiser
region (AgNOR) on PGCL and CGCL of the jaws. MATERIALS AND METHODS: Paraffin wax
blocks of 14 cases of PGCL and 12 cases of CGCL were retrieved. A biotin
streptavidin amplified system was used for identification of the antigens. The
AgNOR number was also evaluated. RESULTS: Ki-67 immunoreactivity was greater in
the mononuclear cells of PGCL compared to CGCL. PCNA and AgNOR staining were
similar in PGCL and CGCL. Prominent MDM2 immunoreactivity was observed in all
tissues investigated. By contrast, there was no p53 immunoreactivity.
CONCLUSIONS: Although CGCL present a more aggressive clinical behaviour, it has a
decreased proliferative activity compared to PGCL. Finally, p53, MDM2, PCNA, Ki
67 immunohistochemical expression and AgNOR histochemical expression do not
reflect their distinct biological behaviour.
PMID- 10673787
TI - Human immunodeficiency virus-positive individuals with oral hairy leukoplakia are
able to mount cytotoxic T lymphocyte responses to Epstein-Barr virus.
AB - OBJECTIVE: Oral hairy leukoplakia (OHL) is a white lesion of the tongue that is
caused by Epstein-Barr virus (EBV) and occurs mainly in people infected with
human immunodeficiency virus (HIV). The aim of this study was to determine
whether the presence of OHL reflects the absence of EBV-specific cytotoxic T
lymphocyte (CTL) activity. SUBJECTS AND METHODS: EBV-specific CTL responses were
measured in HIV-positive homosexual men with OHL, HIV-positive homosexual men
without OHL, and HIV-negative homosexual men. Also, the phenotypes of cells
responsible for EBV-specific responses were studied. RESULTS: Eighty percent
(8/10) of HIV-positive subjects with OHL, 52% (12/23) of HIV-positive subjects
without OHL, and 83% (15/18) HIV-negative subjects had a positive anti-EBV CTL
response (P = 0.004, Kruskal-Wallis test). Two HIV-positive subjects showed a
greater anti-EBV CTL response after developing OHL than before the appearance of
OHL Additional experiments showed that CD8-positive T cells and CD4-positive T
cells were responsible for the EBV-specific CTL responses. CONCLUSION: Our data
show more EBV-specific CTL activities in HIV-positive individuals with OHL than
in HIV-positive individuals without OHL. Whether the presence of EBV-specific CTL
contributes to resolution of OHL remains to be clarified.
PMID- 10673788
TI - [Urinary incontinence after radical prostatectomy: severe ultrasonography changes
following periurethral injection of polytetrafluoroethylene].
AB - The periurethral injection of polytetrafluoroethylene in the treatment of stress
urinary incontinence is a therapeutic option introduced more than 30 years ago
which is considered rapid, effective and burdened with low complications. This
particular therapeutic option when utilized for the treatment of post
prostatectomy incontinence, presents some problems due to the oncologic follow-up
of these patients with particular regard to the presence of local recurrences. In
fact these injections should not interfere with the standard methods of
evaluation of the urethro-vescical anastomosis (DRE and TRUS). The
polytetrafluoroethylene in our experience does not accomplish with these
requirements because it modifies the palpatory and sonographic findings hindering
a reliable evaluation of that region.
PMID- 10673789
TI - [Transurethral treatment of bladder diverticuli].
AB - Since October 1994 we performed endoscopic treatment of bladder diverticula, in
combination with the resolution of cervico-urethral obstruction, in 12 patients.
In a first group of five patients we used the incision of the diverticular neck,
while in a second group of seven patients we associated the electrocoagulation of
the diverticular mucosa to the opening of the diverticular neck. The better
results have been obtained in the second group of patients in which the
diverticula had markedly shrunk in two cases and had totally disappeared in five.
Transurethral treatment of bladder diverticula, with incision of the diverticular
neck and the fulguration of the diverticular mucosa, combined with transurethral
operations for removing the obstruction of the lower urinary tract, is a safe,
fast and effective method.
PMID- 10673790
TI - [Role of urinary cytology in the study of bladder cancer. Comparison with the BTA
test].
AB - Early diagnosis of bladder neoplasia at the moment makes use of urinary cytology
and cystoscopy. The authors describe the results of a study on 62 patients (56
men and 6 women) with bladder neoplasia, and compare the results of urinary
cytology to the BTA test (Bladder Tumor Antigen test), ones, after considering
histological results of TURB (Trans Urethral Resection Bladder) or cystectomy.
Sensibility of urinary cytology was quite better than BTA test sensibility (80.6%
vs 48%). Finally it's described a study on 450 cases of istologically controlled
bladder carcinomas, on which had been executed a cytological analysis before
surgical treatment. The outcome of cytological diagnosis on 414 cases (92%) was
neoplasia. On the basis of their experience, the authors regard cytology as a
fundamental method in diagnostic iter and in follow-up of patients with bladder
neoplasia.
PMID- 10673791
TI - Terazosine and tamsulosin in non bacterial prostatitis: a randomized placebo
controlled study.
AB - Eighteen patients with inflammatory process of the prostate met criteria for the
inclusion in the study: 1) non bacterial prostatitis; 2) no previous treatment.
Then they were randomized into three groups as it follows: terazosine, tamsulosin
and placebo. Alpha-blockers and placebo were given for two months, after which
further uroflowmetry was performed. Symptom score was evaluated before and after
treatment. Terazosine was effective in reducing TO (p = 0.01) as tamsulosin and
placebo did not. Both terazosine (p = 0.034) and tamsulosin (p = 0.006) reduced
max TQ as placebo did not. Symptom score significantly improved in patients
receiving terazosine (p = 0.0002) and tamsulosin (p = 0.001) while
insignificantly in whose receiving placebo.
PMID- 10673792
TI - A multivariate analysis of lower urinary tract ageing and urinary symptoms: the
role of fibrosis.
AB - An investigative trial including 72 patients who underwent open surgery for
benign prostatic hypertrophy (BPH) induced urinary symptoms was carried out with
the purpose to obtain a deeper insight in the pathophysiology of this clinical
picture. Prostate weight, stroma to parenchyma ratio, bladder wall fibrosis, I
PSS score, residual urine and uroflow obtained from these patients were processed
by statistical multivariate analysis. The results point out the pivotal impact of
prostate and bladder wall fibrosis in conditioning biological and chronological
ageing of the lower urinary tract and relative symptoms.
PMID- 10673793
TI - Antiandrogens: a summary review of pharmacodynamic properties and tolerability in
prostate cancer therapy.
AB - This article provides a summary of the pharmacodynamic properties of major
antiandrogens as well as an extensive review of their tolerability. Presently
there are two classes of androgen receptor antagonists: the so-called pure, non
steroidal antiandrogens which include flutamide, nilutamide and the more recent
bicalutamide and the steroidal antiandrogens cyproterone acetate, megestrol
acetate and WIN 49596. Although non steroidal and steroidal compounds have been
found to be equally effective in the treatment of prostate cancer presently no
studies comparing the use of steroidal or non steroidal antiandrogens with
chemical or surgical castration have evaluated quality of life per se. The only
advantage of cyproterone acetate on pure antiandrogens seems to be the low
incidence of hot flushes; a commonly reported adverse effect of androgen ablative
therapy. However, hepatotoxicity associated with long term daily doses of 300 mg
daily and the unacceptably high incidence of cardiovascular side effects (10%)
should restrict its use to patients who are intolerant of pure antiandrogen
compound. In contrast to steroidal compound nonsteroidal compounds let sexual
potency to be retained, which is an important consideration with respect to the
quality of life of some patients and, at present, the main indication for
monotherapy with the pure antiandrogens. As regard as pure antiandrogens
clinically important adverse events including gastrointestinal events,
particularly diarrhea and occasional disturbances of liver function related to
flutamide treatment and antabuse effect, problems with light-dark adaptation and
rare interstitial pneumonitis related to nilutamide indicates the bicalutamide,
due to its better tolerability profile, together with its once-daily oral
administration regimen, could be considered the antiandrogen of first choice in
the treatment of prostatic cancer.
PMID- 10673794
TI - [Leydig cell tumor of the testis. Report of 3 clinical cases].
AB - Leydig cell tumours account for only 1-3% of all testicular neoplasms. They are
commonly detected as palpable masses, but can present with precocious puberty,
gynecomastia or infertility. Although they are usually benign, about 10% of the
reported cases have evolved as a malignant neoplasm. There are no histologic
features pathognomonic for malignancy and metastasis is the only certain
criterion of a malignant. Leydig cell tumour. The follow-up must be prolonged.
The treatment of this tumour is orchidofuniculectomy by inguinal approach,
associated with retroperitoneal lymphadenectomy when regional nodes are involved.
We reports our experience on three cases of Leydig cell tumour of the testis
treated with orchidofuniculectomy. The patients have been submitted to a 9
months, 11 months and 10 years follow-up respectively, and at present they are
without signs of disease.
PMID- 10673795
TI - Renal leiomyosarcoma: report of three cases and review of the literature.
AB - In the present study three cases of renal leiomyosarcoma are presented. All the
patients were complaint about pain at right or left lumbar area and microscopic
or gross haematuria. The clinical examination did not confirm any pathologic
finding. The ultrasonographic and CT scan investigation of the patients revealed
a renal mass. Under the frozen section diagnosis of malignant tumor in two cases
and the cytological diagnosis of renal cell carcinoma in the third case, a
radical nephrectomy was performed. In all the cases the pathological diagnosis
was renal leiomyosarcoma. Because of the rarity of this neoplasm, the literature
is reviewed, presenting the symptoms, the radiological findings, the diagnostic
criteria and the differential diagnosis of the tumor. Radical nephrectomy remains
the treatment of choice for this tumor, which exhibits an aggressive biological
behavior and an unfavorable prognosis.
PMID- 10673796
TI - [Interstitial cystitis: epidemiology].
AB - The epidemiological assessment of intestitial cystitis (IC) is not definitive as
no diagnostic criteria, such as endoscopy or biochemical and anatomopathological
examination, exist. The diagnosis is solely based on symptoms like urgency,
frequency and pelvic pain. The first studies on the population date back from 20
years ago and show a percentage of 10 cases every 100 thousand inhabitants. There
is weak link between genetic factors, immunological diseases, previous cystitis
or eating habits and intestitial cystitis. Epidemiological studies have highlight
the frequency of this disease, and stressed the importance of stricted
behavioural rules for the first stages of intestitial cystitis.
PMID- 10673797
TI - [Urgency-frequency syndrome in women: interstitial cystitis and correlated
syndromes].
AB - In our clinical practice we encountered urgency-frequency syndrome in female
patients. Only in the 3.6% is possible to diagnose a typical interstitial
cystitis (IC). In the 63.6% we observed only local trigonal squamous metaplasia
(leucoplasia), it could be considered a paraphysiological condition present in 50
70% of fertile women, its rigid, not impermeable epithelium may offer an
aethiological hypotesis for the dysuric syndrome. In the treatment of this lesion
by endoscopic infiltration we had syntomatological results with 47.8% of patients
even if only for a short period (one-two years). This treatment is simple and can
be repeated, if the patient is responsive. We noticed that the results did not
change even if we used different drugs probably due to the role of a physical
detachment of leucoplasia from bladder trigon.
PMID- 10673798
TI - [Interstitial cystitis: medical treatment].
AB - Interstitial cystitis is a chronic disease of the bladder and its etiology is
still unknown. In this article we treat the different approaches to this disease,
supported by the fact that a clear therapeutic protocol doesn't exist.
PMID- 10673799
TI - [Interstitial cystitis: surgical treatment].
AB - Surgical therapy of interstitial cystitis must never be considered a first option
but must be reserved for cases, less than 10%, in which conservative therapy has
proven ineffectual. Surgical therapy includes a variety that started at the turn
of the century. Neurosurgical denervation and perivesical denervation like cysto
cystoplasty and cystolysis, manipulate the innervation to reduce the bladder's
hypersensitivity. This surgical approach may be considered in patients in whom
bladder capacity is normal. The results are uncertain and the complications like
neurogenic bladder relevant. Enterocystoplasty is much more widespread because
interstitial cystitis is a benign disease that rarely required radical surgery.
Augmentation cystoplasty and substitution cystoplasty are two variants but only
the later has a rationale as it involves the resection of the detrusor which is
the source of the pain. Detubularization drastically reduced urinary
incontinence. The resection of the detrusor can be supratrigonal, subtrigonal or
at the proximal urethra like in the orthotopic neobladder. If urinary diversion
is chosen, the bladder must be removed. Before recommending surgical therapy each
patient should undergo tests for the localization of the pain; moreover
psychological and gynaecological evaluations should be made. If the bladder
capacity exceeds 400 cc surgical operation is not advisable. If, on the other
hand, the bladder capacity is lower than 400 cc substitution cystoplasty is first
choice. If the patient suffers from trigonal cystitis or urethral
hypersensitivity, urinary diversion is a better therapy. According to the
questionnaires send to the Urologic Departments in Lombardy in 1998, the most
widespread type of operation seems to be supratrigonal cystectomy +
enterocystoplasty and augmentation cystoplasty. Subtrigonal cystectomy or urinary
diversion are only occasionally chosen; continent pouch is the least frequent
therapy at all.
PMID- 10673800
TI - [Interstitial cystitis: local electromotive drug administration (EMDA)].
PMID- 10673801
TI - Storytelling. A strategy for living and coping with cancer.
AB - The purpose of this focused program evaluation was to explore attitudes and
beliefs about storytelling as a strategy for coping with cancer among
participants who attended a cancer-related storytelling workshop. The response
rate was 70% (n = 94) and included persons with a diagnosis of cancer, their
loved ones, and members of the public. The program coordinators used a
theoretical model described by Heiney (1995) that explains how storytelling may
produce therapeutic effects in four domains: cognitive, affective, interpersonal,
and personal. A questionnaire was designed to determine the extent that
conference participants perceived therapeutic benefits in these domains as a
result of attending the workshop. Statistical analysis consisted of descriptive
summaries of individual questions and domain scores. Findings showed that 97% of
the respondents agreed that storytelling was a helpful way to cope with cancer.
Most of the respondents reported agreement with the therapeutic benefits of
storytelling in all domains, with 85% agreeing that hearing others' stories of
living with cancer gave them hope. Although the results of the evaluation were
very positive, further study is needed to demonstrate the efficacy of
storytelling as a strategy for coping with cancer.
PMID- 10673802
TI - The meaning of "not giving in". Lived experiences among women with breast cancer.
AB - This article explores the meaning to women with breast cancer of "not giving in".
Giorgi's phenomenological method was applied, and data were collected through
open interviews. Ten women with breast cancer participated. The analysis resulted
in a general structure of the phenomenon studied, including six key constituents:
accepting the challenge to go on living, working actively on the healing process,
finding something important to live for, gaining insights about life itself,
experiencing awareness and avoidance, and introducing radical change in life. The
results are consistent with literature about strategies in facing death and
development as human conditions. Understanding the phenomenon of "not giving in"
seems to be crucial for nurses in helping women with breast cancer to mobilize
the inner power to survive and develop as human beings.
PMID- 10673803
TI - An analysis of the concept of risk.
AB - The meaning of the word "risk" has changed throughout history. Once a neutral
term, risk has come to represent a combination of probability and something
adverse or dangerous. Phenomena that were previously referred to as hazards,
dangers, or uncertainties are now labeled as risks. Although risk touches every
aspect of health and human welfare, the dimensions of risk as conceptualized in
the fields of epidemiology, nursing science, medical science, and lay health are
qualitatively different. Risk has not been examined as a concept in nursing
literature or research, although risk and related terms are defined in a few
nursing textbooks. Using the evolutionary method of concept analysis, risk is
examined as a concept. This analysis was undertaken to define and clarify the
concept and dimensions of risk as they relate to risk for disease. A sound
understanding of risk as a concept is critical for developing an empirical
knowledge base in nursing and directing nursing research examining issues related
to risk for developing diseases such as cancer.
PMID- 10673804
TI - Nurse-patient communication in cancer care. A review of the literature.
AB - Patients with cancer seem to experience distress particularly in the first period
after diagnosis, and are likely to develop an affective disorder in the first 2
to 3 months. Communicative behaviors of nurses seem to play an important role in
meeting the cognitive and affective needs of patients with cancer. This review of
the literature examines the communicative behaviors of nurses during care
activities with patients who have cancer. The studies show that emphasis is
placed on the affective side, in which facilitating behaviors such as empathy,
touch, comforting, and supporting are considered essential in caring for patients
with cancer. Unfortunately, further studies in this review demonstrate that
communication in oncologic care is complicated by such emotionally laden issues
as the consequences associated with the life-threatening character of the disease
and the far-reaching consequences of the medical treatment. This results in
barriers to effective communication between patients with cancer and nurses. It
is important, therefore, that nurses working with patients who have cancer are
provided both structurally and repeatedly with continuing education programs in
communication. Finally, most of the studies covered in this review have an
explorative character. Future research in this area should pay attention to the
use of controlled studies, large sample sizes, and observational instruments.
PMID- 10673805
TI - Perceptions of caring among patients with cancer and their staff. Differences and
disagreements.
AB - The current dyadic study investigated (a) patient and staff perceptions of the
importance of caring behaviors, patient health, quality of life, and greatest
health-related concern; (b) patient anxiety and depression (Hospital Anxiety and
Depression Scale); and (c) staff views of patient perceptions of the importance
of caring behaviors. The study included 21 matched patient-staff dyads. Three
questionnaire versions of the Caring Assessment Instrument were used to tap
patient (CARE-P) and staff (CARE-S) perceptions, and staff views of patient
perceptions (CARE-SP). There were no correlations between patient and staff
perceptions of the importance of caring behaviors, patient health, quality of
life, or greatest health-related concern. However, staff views of patient
perceptions about the importance of caring behaviors were strongly correlated
with their own perceptions. Staff ratings of the importance of caring behaviors
were not related to patient anxiety, depression, health, and/or quality of life.
Patient depression was negatively correlated with three CARE-Q subscales. The
results indicate that staff are not successful in judging the importance of
caring behaviors, health, quality of life, and greatest health-related concern
for individual patients. The major implication is that staff must be open to
patient perceptions of what caring behaviors are important, and must validate
their own perceptions of patient needs and concerns.
PMID- 10673806
TI - Implementation of an oral care standard for leukemia and transplantation
patients.
AB - The purpose of this project was to develop an oral care standard on two nursing
units in a university hospital where care was given to patients undergoing bone
marrow or stem cell transplantation (BMSCT) and other treatments for leukemia.
Strategies used in this interdisciplinary effort included collaboration,
consultation, education, and evaluation. In the collaboration phase, a core group
of nurses talked with staff about current practices, reviewed literature and
published standards, examined protocols from other institutions, decided on
goals, and developed the standard. Consultation with a dentist, pharmacist, and
physician occurred before completion of the standard. The education phase
included in-service sessions for nurses and technicians. The evaluation phase,
which occurred in two phases, focused on checking to see if the goals had been
met, including tolerability and adherence. The first phase allowed identification
of problem areas and subsequent revisions, whereas the second phase evaluated
adherence at a later time point. Overall, most of the patients adhered to the
standard. Future implications include specific recommendations such as an
emphasis on oral care, documentation, and patient and staff education. This
project is an example of how nurses addressed the challenge of implementing an
acceptable oral care standard to decrease patients' oral complications and
distress.
PMID- 10673807
TI - An instrument to measure symptom experience. Symptom occurrence and symptom
distress.
AB - This article describes the development of an instrument that measures symptom
experience (symptom occurrence and symptom distress). The Adapted Symptom
Distress Scale-2 (ASDS-2), adapted from the McCorkle and Young Distress Scale, is
a 31-item, 5-point, self-report paper-and-pencil instrument that measures
patients' perception of the occurrence and distress of 14 symptoms: nausea,
vomiting, pain, eating, sleep, fatigue, bowel elimination, breathing, coughing,
concentration, lacrimation, changes in body temperature, appearance, and
restlessness. Use of the instrument yields a total score for symptom experience,
scores for symptom occurrence, scores for symptom distress, and subscale scores
for six symptom categories: gastrointestinal, fatigue/restlessness,
concentration, pain/discomfort, respiratory, and appearance. Reliability and
validity were determined with well adults (n = 97), medical-surgical patients (n
= 82), and oncology patients (n = 175). Findings revealed a Cronbach's alpha of
0.91 for symptom experience, 0.90 for symptom occurrence, and 0.76 for symptom
distress. Cronbach's alpha for the subscales ranged from 0.38 for appearance
symptoms to 0.83 for gastrointestinal symptoms. Inclusion of symptoms reported by
patients with cancer strengthened content validity. A contrasted groups approach
was used to demonstrate construct validity.
PMID- 10673808
TI - Influencing nurses' knowledge, attitudes, and practice in cancer pain management.
AB - The purpose of this study was to explore the effects of an education intervention
on nurses' knowledge, attitudes, and practice in pain assessment and management
over 3 months. The education intervention program was designed to change
knowledge and influence the attitudes of registered nurses through a values
clarification process using a conceptual framework based on a theory of
reeducation. Participants in this descriptive, exploratory study were 53 nurses
from six oncology units. Data were collected on their knowledge, attitudes,
documentation practices, and analgesic choices in defined patient situations. The
intervention was effective in changing the knowledge, attitudes, and behaviors of
nurses in the study, but the effect was not maintained over time. Study findings
suggest that further educational and organizational support is needed for
effective practice in pain assessment and management. Further research should
explore education programs that will maintain new knowledge over time. In
addition, assessment of the effect that new knowledge has on the achievement of
improved pain relief for patients should be explored in the future.
PMID- 10673809
TI - Middle Eastern Asian Islamic women and breast self-examination. Needs assessment.
AB - This exploratory, descriptive research study examined the knowledge and frequency
of breast self-examination (BSE) among Middle Eastern Asian Islamic immigrant
women residing in a major metropolitan U.S. city. The purposive sample consisted
of 39 Middle Eastern Asian Islamic immigrant women ranging in age from 20 to 48
years (mean, 33; SD, 8.29). The sample was recruited from women who attended a
local mosque. Data was collected by asking a list of seven questions based on
Champion's BSE tool that assessed knowledge and frequency of BSE.
Sociodemographic information also was collected. The results indicated that 33
women (85%) had heard of breast self-examination, and 29 women (74%) had not
examined their breasts for lumps. None of the participants had examined her
breasts monthly for lumps during the past year. Most of the women had not learned
about BSE from a health professional, nor had they undergone a clinical breast
examination (CBE). The results of this research show that Middle Eastern Asian
immigrant women may be a population overlooked by health care professionals in
the education of BSE. Suggestions to improve breast cancer screening practices
among this population are provided.
PMID- 10673810
TI - Meeting the information needs of adult daughters of women with early breast
cancer. Patients and health care professionals as information providers.
AB - This study explored the information needs of adult daughters whose mothers had
early breast cancer and illustrated the information flows between the daughters
and two information providers: patients and health care professionals (HCPs).
Participants were 97 daughters, who completed a 30-time self-administered
questionnaire, a tool designed to identify the information needs of daughters and
their communication channels. Daughters also completed the Miller Behavioral
Style Scale, a scale used to determine the information-seeking behavior of
individuals under threat. Descriptive statistics revealed that the information
flows between women with breast cancer and daughters participating in this study
were good. Most of the daughters received information from their mothers and
asked their mothers questions. Few daughters thought their mothers avoided giving
them information. The vast majority of the daughters, however, sought information
from sources other than their mothers, indicating that the mothers alone did not
satisfy their information needs. More than half of the daughters participating in
this study accompanied their mothers to their medical consultations and received
information from HCPs. Logistic regression indicated that the communication flows
between patients, HCPs, and adult daughters of women with breast cancer depended
on a number of factors, in particular, on the amount of communication desired by
women with breast cancer.
PMID- 10673811
TI - Planning for implementation of a vendor-based clinical information system. Case
study.
PMID- 10673812
TI - The Internet: an effective tool for nursing research with women.
AB - This article outlines the methodology of using the Internet to survey an
international population of women about their perceptions of breast health
education and screening. Issues to consider in planning and implementing the
research project by Internet are presented. A large population of women from
North America and elsewhere was reached through the establishment of a website
with linkages to other sites frequented by women. Women who visited the website
were asked to complete a questionnaire. Anonymity was guaranteed and simple
instructions were provided at the site. Benefits, limitations, and tips for
success in using the Internet as a research tool are presented. These
investigators found the Internet to be an appropriate medium for health-related
research that also garnered national and international media interest. The
address for this website is http:@www.uwindsor.ca/breast.study/quest.htm.
PMID- 10673813
TI - The effects of Internet-based distance learning in nursing.
AB - Distance learning has been the turning point for accomplishing adult learning in
nursing education. This article describes the development and structure of a
distance-learning course used to deliver distance learning to the RN-BSN students
at Yonsei University, College of Nursing. The distance-learning course was
developed cooperatively by content experts, instructional designers, programmers,
and graphic designers. The course content, "Growth and Development", was a
computerized instructional course delivered using the Internet. The programming
system was developed on the Web Server and Oracle DB through the Internet. The
characteristics of adult learners--graduates with 3-year RN diplomas and working
full-time--were considered during development of the course. For a semester, the
students studied the growth and development of a person from infancy to
adolescence through interactions with peers and instructors using alternative
menus on the Internet. The course was evaluated from feedback of 60 RN-BSN
students on their satisfaction with this distance-learning course in regard to
instructional design, the arrangement and structure of instruction, and the
function and feasibility of the courseware. When the self-reported questionnaire
with 25 open questions was evaluated, students' general responses were relatively
positive. Insufficient feedback from the professor, excessive time and
difficulties experienced when connecting to the Internet, and the lack of
information about related websites were primary negative responses. For an
effective use of the distance-learning system, improvements to the
telecommunications network service are crucial. School authorities should support
the professors who are interested in developing distance-learning courses so that
the courses can be developed with technical perspectives. More distance-learning
courses applying interactive multimedia instructional design through the Internet
should be developed with the improved network service in the future.
PMID- 10673815
TI - Computer-based support groups. Nursing in cyberspace.
AB - The focus of this article is on the nurse monitor role in a project whose overall
goal is to use telecommunication technology to provide information and support to
middle-aged rural women living with chronic illness. The impact of participation
in these support groups on the women's psychosocial health is also discussed. The
purpose of the project, the underlying conceptual framework of social support, a
project overview, project philosophy and protocols, and the role of the Nurse
Monitor are described.
PMID- 10673814
TI - Integrating Web-based instruction into a graduate nursing program taught via
videoconferencing. Challenges and solutions.
AB - This article describes the methods used, problems encountered, and solutions that
were generated while integrating Web-based instruction (WBI) into a Master of
Science in Nursing Leadership and Case Management, and a Post-Master's Case
Management certificate distance education program taught via video-conferencing.
The writer describes the use of computer-mediated communication to enhance
collaboration between and among students at 11 video-conferencing sites. The
integration of WBI to support collaboration was successful because students and
faculty could complete their academic activities in the locations and times that
were most convenient to them. The tools that WBI provided were instrumental in
helping students submit collaborative work that faculty often identified as far
exceeding their expectations.
PMID- 10673816
TI - The Internet: an underutilized tool in patient education.
AB - Internet technology is helping to reshape patient education. An illustration of
this is provided by data from a two-stage pilot study involving 100 senior
citizens who received instruction on how to conduct health information searches
on the Internet. The goals were to enable the seniors to assume an active role in
their health care and to share their information with family and friends. In a
Train-the-Trainer approach, 20 trainers received instruction on searching for
health information on the Internet, and subsequently trained 100 senior citizen
trainees. The study was conducted from October 1997 to June 1998. The average age
of the senior trainees was 69. Most had a college education. The study results
reveal a positive impact of the training on senior trainee confidence in using
the computer and the Internet, conducting health information searches online, and
sharing health care information with their physicians, families, and friends.
Some gender and educational differences were noted. In a 90-day posttraining
follow-up, 66% of the trainees continued to use the Internet, with 47% of them
using it to search for health information. Two thirds of those who searched for
health information on the Internet talked about it with their physicians, with
more than half reporting they were more satisfied with their treatment as a
result of their searches and subsequent discussion with their physicians. These
findings are relevant to patient education in the nursing curricula of nursing
students and nurse practitioners. Some suggestions are given to improve the
effectiveness of the training program.
PMID- 10673817
TI - Children of depressed mothers.
PMID- 10673818
TI - Selective serotonin reuptake inhibitor-induced mydriasis.
PMID- 10673819
TI - Olanzapine in Tourette's disorder.
PMID- 10673820
TI - Olanzapine in Tourette's disorder.
PMID- 10673821
TI - Secondary enuresis associated with obstructive sleep apnea.
PMID- 10673822
TI - Sexual obsessions in obsessive-compulsive disorder.
PMID- 10673823
TI - Language disorders: a 10-year research update review.
AB - OBJECTIVE: To review the past 10 years of research in child language or
communication disorders, which are highly prevalent in the general population and
comorbid with childhood psychiatric disorders. METHOD: A literature search of 3
major databases was conducted. The child language literature, describing the
domains of language development--phonology, grammar, semantics, and pragmatics-
is reviewed. RESULTS: Disorders of grammar, semantics, and pragmatics, but not
phonology, overlap significantly with childhood psychiatric disorders. Receptive
language disorders have emerged as high-risk indicators, often undiagnosed.
Language disorders and delays are psychiatric risk factors and have implications
for evaluation, therapy, and research. However, they are often undiagnosed in
child mental health and community settings. The research has focused mostly on
monolingual English-speaking children. CONCLUSION: Awareness of basic child
language development, delay, and deviance is crucial for the practicing child and
adolescent psychiatrist, who must diagnose and refer relevant cases for treatment
and remediation. Future research needs to address the growing language diversity
of our clinical populations.
PMID- 10673824
TI - Effectiveness of nonresidential specialty mental health services for children and
adolescents in the "real world".
AB - OBJECTIVE: Although many studies demonstrate the efficacy of a variety of
treatments for child and adolescent psychiatric disorders, studies showing the
effectiveness of such treatments in ordinary clinical settings have not been
forthcoming. This report presents a study of the effectiveness of outpatient
treatment in a community sample of 9- to 16-year-olds. METHOD: Four annual waves
of data were collected from a representative sample of 1,422 children and their
parents in the southeastern United States. Interviews were conducted with the
Child and Adolescent Psychiatric Assessment to determine clinical status and the
Child and Adolescent impact Assessment to measure the impact of psychiatric
disorder on the lives of the children's families. RESULTS: Treated individuals
were more severely disturbed and showed deterioration in their clinical status,
even before they received treatment, indicating that comparisons with untreated
individuals required controls not only for pretreatment clinical status, but for
pretreatment clinical trajectory. A significant dose-response relationship was
found between the number of specialty mental health treatment sessions received
and improvement in symptoms at follow-up. However, no effect of treatment on
secondary psychosocial impairment or parental impact was identified. CONCLUSIONS:
Child and adolescent outpatient psychiatric treatment has positive effects on
psychiatric symptoms, even when conducted outside the academic units where
efficacy research usually takes place. The dose of treatment required to produce
such effects (more than 8 sessions) suggests that attempts to limit child
psychiatric treatment to very short-term interventions may be counterproductive.
PMID- 10673825
TI - Dose effect in child psychotherapy: outcomes associated with negligible
treatment.
AB - OBJECTIVE: To compare the outcomes of children who received negligible amounts of
outpatient treatment to children receiving more treatment. METHOD: A random
regression longitudinal model was used to analyze outcomes of children (aged 5-17
years) from the Fort Bragg Evaluation Project. RESULTS: In examining several
outcomes, the results show no statistically significant dose effect. CONCLUSIONS:
Children receiving substantial amounts of treatment showed no better mental
health outcomes than those receiving negligible amounts of treatment. The results
do not support the existence of a dose effect consistent enough to guide
clinicians, administrators, or policymakers.
PMID- 10673826
TI - Commentary: more outcome studies are needed.
PMID- 10673827
TI - Commentary: the dose effect in children's mental health services.
PMID- 10673828
TI - Strengths of children and adolescents in residential settings: prevalence and
associations with psychopathology and discharge placement.
AB - OBJECTIVE: During the past few years there has been growing interest in
developing strength-based approaches to services, particularly for children and
adolescents. METHOD: This study assesses the prevalence of 30 strengths for a
random sample of children and adolescents in residential placements in Florida.
In addition, the relationship between strengths and clinical and functional
characteristics is studied. RESULTS: Results suggest that there is substantial
variation across individuals on the presence of strengths and the potential for
development. Strengths were associated with symptoms, risk behaviors, and
functioning. Level of strengths predicted success in the reduction of risk
behaviors during the child/adolescent's stay. In addition, the level of strengths
was independently associated with good dispositional outcomes. CONCLUSIONS: The
findings provide further empirical support for the importance of strengths and
the utility of an integrated model that considers both psychopathology and
strengths in planning for children's services.
PMID- 10673829
TI - National Institutes of Health Consensus Development Conference Statement:
diagnosis and treatment of attention-deficit/hyperactivity disorder (ADHD)
AB - Attention-deficit/hyperactivity disorder (ADHD) is a commonly diagnosed
behavioral disorder of childhood that represents a costly major public health
problem. Despite progress, ADHD and its treatment have remained controversial,
especially the use of psychostimulants for both short- and long-term treatment.
Although an independent diagnostic test for ADHD does not exist, there is
evidence supporting the validity of the disorder. Studies (primarily short-term,
approximately 3 months), including randomized clinical trials, have established
the efficacy of stimulants and psychosocial treatments for alleviating the
symptoms of ADHD and associated aggressiveness and have indicated that stimulants
are more effective than psychosocial therapies in treating these symptoms.
Because of the lack of consistent improvement beyond the core symptoms and the
paucity of long-term studies (beyond 14 months), there is a need for longer-term
studies with drugs and behavioral modalities and their combination. Although
trials are under way, conclusive recommendations concerning treatment for the
long term cannot be made at present. There are wide variations in the use of
psychostimulants across communities and physicians, suggesting no consensus
regarding which ADHD patients should be treated with psychostimulants, and thus
the need for improved assessment, treatment, and follow-up. Furthermore, the lack
of insurance coverage, preventing the appropriate diagnosis and treatment of
ADHD, and the lack of integration with educational services are substantial
barriers and represent considerable long-term costs for society. Finally, after
years of clinical research and experience with ADHD, knowledge about the cause or
causes of ADHD remain largely speculative. Consequently, there are no documented
strategies for the prevention of ADHD.
PMID- 10673830
TI - Commentary: the NIH ADHD Consensus Statement: win, lose, or draw? [ comment].
PMID- 10673831
TI - Treatment services for children with ADHD: a national perspective.
AB - OBJECTIVE: To summarize knowledge on treatment services for children and
adolescents with attention-deficit hyperactivity disorder (ADHD), trends in
services from 1989 to 1996, types of services provided, service mix, and barriers
to care. METHOD: A review of the literature and analyses from 2 national surveys
of physician practices are presented. RESULTS: Major shifts have occurred in
stimulant prescriptions since 1989, with prescriptions now comprising three
fourths of all visits to physicians by children with ADHD. Between 1989 and 1996,
related services, such as health counseling, for children with ADHD increased 10
fold, and diagnostic services increased 3-fold. Provision of psychotherapy,
however, decreased from 40% of pediatric visits to only 25% in the same time
frame. Follow-up care also decreased from more than 90% of visits to only 75%.
Family practitioners were more likely than either pediatricians or psychiatrists
to prescribe stimulants and less likely to use diagnostic services, provide
mental health counseling, or recommend follow-up care. About 50% of children with
identified ADHD seen in real-world practice settings receive care that
corresponds to guidelines of the American Academy of Child and Adolescent
Psychiatry. Physicians reported significant barriers to service provision for
these children, including lack of pediatric specialists, insurance obstacles, and
lengthy waiting lists. CONCLUSIONS: The trends in treatment services and
physician variations in service delivery point to major gaps between the research
base and clinical practice. Clinical variations may reflect training differences,
unevenness in the availability of specialists and location of services, and
changes in health care incentives.
PMID- 10673832
TI - Predictors of panic attacks in adolescents.
AB - OBJECTIVE: To identify risk factors for onset of panic attacks in adolescents, a
prospective cohort design was used to evaluate the following risk factors:
negative affectivity, female sex, anxiety sensitivity, and childhood separation
anxiety disorder. These risk factors were also evaluated for predicting onset of
major depression to test their specificity. METHOD: The sample consisted of 2,365
high school students assessed over a 4-year period. Assessments included self
report questionnaires and structured clinical interviews. Cox proportional
hazards models were used to evaluate risk. RESULTS: Consistent with previous
studies, prior major depression predicted onset of panic attacks and a history of
panic attacks predicted onset of major depression. After adjusting for the
effects of prior major depression, negative affectivity and anxiety sensitivity,
but not female sex or childhood separation anxiety disorder, predicted onset of 4
symptom panic attacks. However, female sex and negative affectivity but not
anxiety sensitivity or childhood separation anxiety disorder predicted onset of
major depression after adjustment for the effects of prior panic attacks.
CONCLUSION: Negative affectivity appears to be a nonspecific risk factor for
panic attacks and major depression, whereas anxiety sensitivity appears to be a
specific factor that increases the risk for 4-symptom panic attacks in
adolescents.
PMID- 10673833
TI - Relationship between depression and substance use disorders in adolescent women
during the transition to adulthood.
AB - OBJECTIVES: To examine the continuity of substance use disorder (SUD) in
adolescent women during the transition to adulthood and to assess psychosocial
functioning associated with SUD. Furthermore, to examine concurrent and
longitudinal relationships' between major depressive disorder (MDD) and SUD
during this developmental transition. METHOD: One hundred fifty-five women, aged
17 to 19 years, were recruited from 3 high schools and were followed annually for
5 years. Comprehensive diagnostic and psychosocial assessments were performed
with standardized instruments. The primary outcome measures included MDD and SUD
during follow-up in those with and without a prior history of MDD or SUD, and
psychosocial functioning associated with SUD. RESULTS: The 5-year incidence of
SUD was 9.6% and, by the end of follow-up, 18.7% had a lifetime episode. Prior
SUD significantly increased the risk for SUD diagnosis during the study. Co
occurrence of MDD and SUD was high during adolescent and early adult years, with
episodes of both disorders occurring in close temporal proximity. SUD also
predicted MDD over time, but the reverse was not true. After controlling for the
effects of MDD on social adjustment, SUD was associated with significant
impairment in school functioning. CONCLUSIONS: These results suggest that the
risk for new onset and recurrence of SUD is high during the developmental
transition to adulthood. SUD during this developmental period is associated with
significant school-related problems. The findings also suggest that SUD and MDD
frequently co-occur during the post-high school transition in women. Given the
significant psychosocial dysfunction associated with these illnesses, early
detection of these problems and effective intervention are crucial.
PMID- 10673834
TI - General and specific childhood risk factors for depression and drug disorders by
early adulthood.
AB - OBJECTIVE: To identify childhood risk factors that predict depression and drug
disorders by early adulthood, distinguishing between general risk factors for
both disorders and specific risk factors for each individual disorder. METHOD:
Within a longitudinal community study (N = 360), familial and behavioral
emotional characteristics were assessed in early childhood (ages 5, 6, and 9
years). At age 21, the Diagnostic Interview Schedule, version III-revised,
provided lifetime diagnoses of major depression and drug abuse/dependence.
RESULTS: Sibling substance use disorders predicted depression and drug disorders
for both genders. Feelings of anxiety, depression, and peer rejection were
general predictors for females. Specific risk factors for depression were
parental depression and anxious/depressed behavior in both genders and peer
problems for males. Specific risk factors for drug abuse/dependence were larger
family size, lower socioeconomic status, hyperactivity, attention problems, and
aggression. Parental substance abuse and having younger parents were specific
risk factors for drug disorders in males. CONCLUSIONS: Familial and behavioral
emotional risk factors for depression and drug disorders were primarily specific,
suggesting separate pathways. The unique perspectives of multiple informants
facilitate early identification.
PMID- 10673835
TI - Competence and behavioral/emotional problems among Taiwanese adolescents as
reported by parents and teachers.
AB - OBJECTIVE: To investigate competence and behavioral/emotional problems among
nonreferred adolescents in Taiwan, using a Chinese version of the Child Behavior
Checklist (CBCL-C) and the Teacher's Report Form (TRF-C). The psychometric
properties of these instruments and cross-cultural differences were also
examined. METHOD: Parents of 854 junior high school students aged 12 to 16 years
in Taipei, Taiwan, were asked to complete the CBCL-C. Among these students, 162
had their teachers' ratings of the TRF-C. RESULTS: The internal consistency and 1
month test-retest reliability were satisfactory for both the CBCL-C and TRF-C,
which were moderately correlated. Both exploratory and confirmatory factor
analysis provided some support for the validity of Achenbach's cross-informant
model. Parents' reports showed that compared with their American counterparts,
Taiwanese adolescents tended to have lower scores on most competence scales,
higher scores on scales that reflect covert behavior problems, and lower scores
on scales that reflect more overt behavior problems. However, teachers' reports
showed no significant differences on most competence and behavior problem scales.
CONCLUSION: The CBCL-C and TRF-C are useful tools for assessing the mental health
status of Taiwanese adolescents. The cross-cultural differences in adolescent
behavior problems are discussed.
PMID- 10673836
TI - Effects of parent personality, upbringing, and marijuana use on the parent-child
attachment relationship.
AB - OBJECTIVE: To examine the predictors of the quality of the parent-child
attachment relationship among a sample of 248 young adults with children. METHOD:
In this longitudinal study, data were collected during early adulthood in 1992
and in 1996/1997 via a structured questionnaire. Using logistic regression and
multiple regression analyses, the authors assessed the extent to which
participants' personality attributes, substance use, and relationships with their
mothers predicted the quality of the parent-child bond. RESULTS: Logistic
regression models showed that participants with certain personality attributes
(e.g., high sensitivity), less frequent marijuana use, or a close relationship
with their mothers had a greater likelihood of having a close parent-child
attachment relationship with their own children at a later time. Regression
analysis also showed that the risk of earlier substance use on the parent-child
relationship was offset by protective factors in the parents' personality domain.
In addition, protective factors in the various parental domains synergistically
interacted with a low frequency of marijuana use, relating to a closer parent
child attachment relationship. CONCLUSIONS: The findings suggest that certain
parenting styles are transmitted across generations and interventions in the
personality and drug use domains can help increase the likelihood that parents
will form close attachment relationships with their own children.
PMID- 10673837
TI - Selective mutism and comorbidity with developmental disorder/delay, anxiety
disorder, and elimination disorder.
AB - OBJECTIVES: To assess the comorbidity of developmental disorder/delay in children
with selective mutism (SM) and to assess other comorbid symptoms such as anxiety,
enuresis, and encopresis. METHOD: Subjects with SM and their matched controls
were evaluated by a comprehensive assessment of the child and by means of a
parental structured diagnostic interview with focus on developmental history.
Diagnoses were made according to DSM-IV. RESULTS: A total of 54 children with SM
and 108 control children were evaluated. Of the children with SM, 68.5% met the
criteria for a diagnosis reflecting developmental disorder/delay compared with
13.0% in the control group. The criteria for any anxiety diagnosis were met by
74.1% in the SM group and for an elimination disorder by 31.5% versus 7.4% and
9.3%, respectively, in the control group. In the SM group, 46.3% of the children
met the criteria for both an anxiety diagnosis and a diagnosis reflecting
developmental disorder/delay versus 0.9% in the controls. CONCLUSIONS: SM is
associated with developmental disorder/delay nearly as frequently as with anxiety
disorders. The mutism may conceal developmental problems in children with SM.
Children with SM often meet diagnostic criteria for both a developmental and an
anxiety disorder.
PMID- 10673838
TI - Case study: possible traumatic stress disorder in an infant with cancer.
AB - The posttraumatic stress disorder model has been used to describe some children's
experience with cancer. This article presents the case of a 5-month-old infant in
whom a neuroblastoma was diagnosed at age 2 weeks. His symptoms at the time of
the psychiatric consultation were consistent with the criteria for traumatic
stress disorder in infants from the ZERO TO THREE: Diagnostic Classification.
This case study invites future clinical and research queries about traumatic
stress disorder in infants with serious medical illnesses.
PMID- 10673839
TI - Research questions and hypotheses.
PMID- 10673840
TI - Genetics of childhood disorders: XI. Fragile X syndrome.
PMID- 10673841
TI - Rickets and deprivation: a Nigerian study.
AB - Under-fives in 461 households were assessed clinically to determine the
prevalence of rickets in sub-urban and rural communities in the Sahel savanna.
Overt rickets was found in 11 (2.4%) of households and abnormalities suggestive
of rickets in 69 (14.9%). There were significant variations (p < 0.05) in the
prevalence of rickets in association with ethnic grouping (higher in southerners
and non-Kanuri, non-Hausa-Fulani northerners), religion (more prevalent among
Christians), and mother's occupation and educational status (higher with working
class mothers and mothers with at least a primary education). A significantly
higher prevalence was also associated with late introduction (at more than seven
months of age) of cereals to the infant's diet, more than one under-five in a
household and presence of under-fives aged 13-43 months. In contrast, no
significant variations in prevalence were observed in association with duration
of breast feeding, use of multivitamins or cod liver oil, history of convulsions
in under-fives, sex, nutritional status, or history of diarrhoea within a recall
period of six months. Thus, rickets is common in under-fives in rural and sub
urban communities in the Sahel savanna and may be related more to environmental
and dietary factors than to culture and religion. Further studies are required to
determine the relative roles of vitamin D or calcium deficiency to facilitate the
planning and execution of a community-based intervention programme in the area.
PMID- 10673842
TI - Obesity among Kuwait University students: an explorative study.
AB - University students' dietary habits have been criticised for their nutritional
inadequacy and faddism. Kuwait University students may face the risk of obesity
because of affluence and modernization and the dynamic changes in their level of
physical activity and caloric intake. This promoted a study of a random sample of
842 Kuwait University students for dietary and socioeconomic factors associated
with obesity. Weight and height were measured to calculate the body mass index
(BMI), which is the weight in kilograms divided by the height in meters squared
(kg/m2). Obesity was classified into grade 1 and 2 (BMI > 25 and > 30 kg/m2). The
associated factors studied and obtained through questionnaires included gender,
age, marital status, parental obesity, education and occupation, dieting, last
dental and health check-up, year of study, number of siblings (total, brothers
and sisters), eating in between meals, high school and college GPA and major,
exercising, number of regular meals eaten, obese relatives, those living at home,
and servants, highest desired degree, birth order, having a chronic disease,
countries prefer visiting, family income, governorate, and socioeconomic status
(SES). Grade 1 and 2 obesity were found to be 32.0 and 8.9%, respectively.
Factors that were found to be significantly associated with obesity included
gender, age, marital status, obesity among parents, dieting, last physical check
up, year of study, number of brothers, sisters and regular meals eaten and high
school GPA. Logistic regression analysis revealed that the same factors
significantly contributed to the development of obesity except the last four. The
level of obesity among Kuwait University students is high. Obesity is a risk
factor for a variety of chronic diseases. There is a need to address the
challenge of instituting measures that would reduce the future ill-effects of
obesity on young adults. It is widely believed that during the young adult years
many important health habits are formed and set. It is at this stage (or earlier)
that wellness and self-care programming for college students is essential and
worthy of being explored and its efficacy assessed.
PMID- 10673843
TI - Healthy housing: the role of the environmental health officer.
AB - The relationship of health and housing has been well documented. There is less
said about action that can be taken to deal with poor housing conditions.
Environmental Health Officers in UK Government are key actors enforcing
legislation relevant to housing conditions. Despite a century of legislative
intervention in private sector housing conditions, the English House Condition
Survey continues to report an excessive amount of poor conditions, and a
particular decline in quality amongst the most disadvantaged in society who are
increasingly accommodated in the private rented sector. This paper examines the
role of poor housing in ill health and the difficulties faced in enforcing
largely reactive legislative, arguing that wider changes are needed if the link
between poor health and housing is to be broken.
PMID- 10673844
TI - Is continued weight gain inevitable in type 2 diabetes mellitus?
AB - Prevention and treatment of obesity are major clinical problems encountered in
the management of Type 2 diabetes mellitus (DM); indeed, up to 90% of such
patients are regarded as being overweight. Except for a brief period following
diagnosis, when presumably enthusiasm to adopt lifestyle change is at its
greatest, weight gain is generally progressive unless severe hyperglycaemia or
complications intervene. Even a relatively modest weight loss of 10% can have
major benefits in terms not only of reducing the risk of developing DM in the
first place, but also in improving metabolic control after the disorder has
become established. Behavioural therapy (BT) in combination with hypocaloric diet
achieves weight loss in the short-term, but is poorly sustained in the long-term.
Exercise has metabolic benefits beyond its rather minimal effects on short-term
weight loss in that it may also aid long-term weight control. The difficulties
encountered in maintaining lifestyle change do, however, suggest the need for
ongoing intervention--perhaps including a regular period on a stricter dietary
regimen (800-1000 kcalday-1), possibly a very low calorie diet (VLCD)(< 800
kcalday-1) or even the use of orlistat, a pancreatic lipase inhibitor which
reduces the absorption of dietary fat. Realistically, the aim should be for long
term weight stability.
PMID- 10673845
TI - Possible health and safety problems in the use of novel plant essential oils and
extracts in aromatherapy.
AB - Aromatherapy is a branch of complementary or alternative therapy which is
increasing in popularity, yet has scant scientific credibility. Aromatherapy
should be defined as treatment using odours and practised as such. However,
essential oils are usually used in conjunction with massage and often combined
with counselling of some kind. The use of most commonly-used essential oils in
massage is seldom dangerous, as they have low systemic toxicity, especially when
used at 2% dilution (provided they are not adulterated); however their safety
during pregnancy, childbirth and babies has not been clearly demonstrated.
Sensitisation, however, is a growing concern. Some aromatherapists are now
introducing novel plant essential oils, extracts and phytols into their massage
routine many of which have no odour and are potentially toxic. The possible
dangers of these plant products are therefore discussed using specific example.
PMID- 10673846
TI - Cognitive behaviour therapy: its evolution and basic principles.
AB - The historical and theoretical background to Cognitive Behaviour Therapy (CBT) is
outlined. The main therapeutic approaches of Behaviour Therapy (BT) and Cognitive
Therapy (CT) are described--and an overview is provided of the applications of
these approaches to clinical problems. The relationships between BT, CT and CBT
are clarified.
PMID- 10673848
TI - Overweight and obesity in the Arabian Peninsula: an overview.
AB - Obesity greatly increases the risks of developing diseases, including diabetes
mellitus, hypertension, dyslipidaemia, coronary artery disease, and some cancers.
At least one-third of Arabs are obese, as defined by body mass index (BMI) more
than 30 kg/m2 and this figure is rising steadily despite increased interest in
fitness. Women have particularly high rates of obesity. Obesity is clearly
associated with increased risk for mortality, but there has been controversy
regarding optimal weight with respect to mortality risk. A review of recent
studies on the prevalence of obesity among population of the Arabian Peninsula
and the evaluation of the health risk of obesity is presented in this paper. The
prevalence of obesity ranges between 16-25% in men and 17-43% in women. The most
prevalent chronic diseases related to obesity in these populations are diabetes,
hypertension and coronary heart disease (CHD).
PMID- 10673849
TI - Occupant injury protection in automobile collisions.
AB - Modern technology has produced automotive vehicles that have become both a luxury
and a necessity in modern civilization. They have become highly useful, even more
varied in form and function, and capable of high speeds on crowded roadways. One
unfortunate consequence is the high frequency of accidents and the greater
severity of injuries when collisions do occur. In response, modern technology has
produced a variety of safety and health features, devices and designs intended
for better occupant protection on in high speed vehicles. Injury reduction has
become a prime design objective, but there are residual risks, which, as
technology evolves, require effective communication to those risk. There can be
little risk avoidance behavior without awareness of the hazards and effective
communication to the vehicle occupant, as to what could and should be done for
self-protection. For example, one out of three drivers apparently fails to
understand the function of head restraints, few understand the 'safe zone'
posture required for air bags and many believe safety features should be adjusted
only for comfort. Some of the current residual injury producing problems in
occupant systems are specifically described here in order to illustrate what is
needed in terms of both design remedies and health promotion activities.
PMID- 10673847
TI - Hospital transformation and organisational learning.
AB - Kwong Wah Hospital was founded by the charity organisation Tung Wah Group of
Hospitals some 88 years ago, with management transfer to the Hong Kong Hospital
Authority in 1991. Capitalizing both from the traditional caring culture of its
founder, as well as opportunities in the new management environment, the hospital
has scored remarkable successes in service quality, community partnership,
organisational effectiveness, and staff development. Underpinning these
transformations were Structure, Process, People, and Culture strategies. The
learning imperative is heavily mandated or the success of each of these strands
of development. Indeed, the embodiment of a learning organisation culture
provides the impetus in sustaining the change momentum, towards achieving the
Vision of becoming a 'Most Preferred Hospital' in Hong Kong.
PMID- 10673850
TI - The 1998 APHA Annual Lecture. What the UK can teach the US about health care.
PMID- 10673851
TI - Lessons to be learned: a case study approach: metastatic bronchogenic carcinoma
presenting as a gluteal abscess.
AB - It is well known that bronchogenic carcinoma frequently metastasises to the bony
skeleton, but it is most unusual for it to present in the form of a
musculoskeletal abscess. Presented here is the case report of a patient with what
appeared initially to be a right sided gluteal abscess and which turned out to be
the metastasis from a bronchogenic carcinoma. The Magnetic Resonance Image (MRI)
scan carried out proved to be very helpful in arriving at a probable clinical
diagnosis; however, it was histopathological studies of the abscess wall itself
that ultimately gave the definitive diagnosis. We believe that this may represent
one of the first documented cases in which on MRI scan has been used to confirm
the presence of a gluteal abscess.
PMID- 10673852
TI - [Current diagnostic method, prognosis estimation and therapy of papillary thyroid
cancer: recommendations of the medical universities and the National Oncologic
Institute of Budapest].
AB - Physical examination, cervical ultrasonography (US) and aspiration cytology are
the mainstays of the preoperative diagnostics of papillary thyroid carcinoma. For
the staging of suspected malignant cases, cervical and mediastinal CT (MRI for
inconclusive results) is indicated before any surgery. The end-result of primary
treatment is assessed by total-body iodine scintigraphy and the serum human
thyroglobulin (hTG) level. For long-term follow-up, physical examination and the
serum hTG level are the most reliable tools (6-monthly), supplemented by cervical
US and chest X-ray (yearly), and total-body iodine scintigraphy (2-yearly). If
these furnish positive results, further examinations may be indicated. In
suspected relapses of hTG non-producing and iodine non-accumulating papillary
carcinomas, 201thallium chloride or 99mTc-sesta-MIBI (methoxy-isobutyl
isonitrile) scintigraphy, and positron emission tomography with 18fluoro
deoxyglucose or 11C-methionine may be of help. For estimation of the prognosis
(cause-specific survival) of the patients, the MACIS score system of the Mayo
Clinic is widely accepted, the patients being divided into low-risk and
intermediate/high-risk categories. The recommended standard surgical intervention
is near-total thyroidectomy (2-4 g residual glandular tissue left at the upper
pole of the less-involved lobe), with a central cervical lymph node dissection
for diagnostic purposes. In cases of lymph node dissemination, dissection
(radical, modified radical, selective or microdissection) of any of the involved
compartments (central, right or left cervical, or upper mediastinal) is indicated
for therapeutic reasons, the method of which is depending on the extent of the
metastatic involvement. Following adequate surgical intervention, no adjuvant
radioiodine therapy is indicated for low-risk cases with a tumour of less than 1
cm diameter. For other low-risk or intermediate/high-risk patients, radioiodine
ablation (R0N0M0) or a therapeutic radioiodine dosage (R2N1M1) is indicated. In
cases at high-risk of local/regional relapse and in radioiodine non-accumulating
tumorous cases, external radiotherapy may be applied. Thyroid hormone medication
in a TSH suppressive dose is indicated during the first 5 postsurgical years: the
goal is to achieve a TSH level below 0.1 (determined by a 3rd generation assay).
If no relapse occurs or the case is a low-risk one, following the 5 years, it is
enough to maintain the TSH level in a subnormal range (0.1-0.3).
PMID- 10673853
TI - [Prevalence of mood and anxiety disorders in the Hungarian adult population].
AB - The prevalence rates of affective and anxiety disorders in the Hungarian adult
population were assessed with a well-structured questionnaire which has been
successfully applied in several multinational epidemiological studies. The
Hungary material showed significantly higher lifetime and period prevalence rates
of bipolar disorders than is found in most of related literature. However, the
frequency of other affective disorders and the anxiety states strongly
corresponded with international findings.
PMID- 10673854
TI - [Effect of fibrates on lipid metabolism and the blood coagulation system].
AB - The authors summarised the complex effects of fibrates on atherogen dyslipidaemia
and the blood coagulation system, as well as the results of previous intervention
studies with fibrates. They also give an overview of the favourable molecular
effects of fibrates and the role of peroxysoma proliferator activated receptor
alpha (PPAR-alpha).
PMID- 10673855
TI - [Competitive polymerase chain reaction: a new method for measuring N-myc
amplification].
AB - The highly variable biological behaviour of neuroblastoma, a neoplasm which
belongs to the family of primitive neuroectodermal tumours, is determined by its
molecular pathological characteristics. Among them amplification of the N-myc
gene is the most important factor in both therapeutic and prognostic points of
view. Value of the amplification can be determined by different methods. The
latest of them is the competitive polymerase chain reaction (PCR), essence of
which is the parallel reaction of the target N-myc gene (exon 3.) and the endogen
competitor CF gene (exon 3.) in the same reaction solution. The authors applied
the method on 11 neuroblastoma cases diagnosed between 1994 and january of 1999.
In three cases the amplification was determined also by fluorescens in situ
hybridization (FISH). Six of the 11 cases were detected to have more than 10
fold, two of the six about 100-fold N-myc amplification. Results of the PCR and
FISH correlated well. The two methods applied by the authors complete each other
and are appropriate for determining the gene amplification which gives valuable
prognostic and therapeutic information about the examined tumour.
PMID- 10673856
TI - [Refsum disease].
AB - For the first time in literature the authors interpret the pathography of
Refsum's disease, in the case of their patient, as pseudo-hypervitaminosis A. The
biochemical basis of the clinical picture is a defect in the activity of phytanic
acid-alpha-hydrolase belonging to the peroxisomal system. As a consequence,
phytanic acid accumulates in the serum and in the parenchymal tissues. Retinol,
an alcohol with high molecular weight, is a natural ligand of nuclear RXR
(retinoid-X-receptor), which plays an important role in the regulation of
peroxisoma synthesis. In Refsum's disease the phytanic acid accumulated because
of the enzyme defect competes with the biotransformation derivates (all-trans
retinoic acid, 9-cis-retinoic acid) of the all-trans-retinol (vitamin A) for the
nuclear RX receptor binding sites, and as a very potent receptoractivator it
causes the intestinal symptoms of hypervitaminosis A. The authors review the
procedure of fatty-acid chromatography necessary for the establishment of the
diagnosis and discuss--in addition to dietary restrictions--recent therapeutic
possibilities, like plasmapheresis, cascade filtration, lipapheresis and oral
batylalcohol treatment.
PMID- 10673857
TI - Information management and technology (IM&T): can the clinicians get there before
government?
PMID- 10673858
TI - Problems associated with manpower.
PMID- 10673859
TI - An important anniversary.
PMID- 10673860
TI - Surgical training for overseas doctors: an historical review and proposals for
the future.
PMID- 10673861
TI - Surgical training after MRCS: the SHO III gap.
PMID- 10673862
TI - A recurring theme.
PMID- 10673863
TI - Basic surgical skills courses: an educational success story.
PMID- 10673864
TI - The implications of cancer therapy for oral health: a report of a meeting held on
12 March 1999.
PMID- 10673865
TI - Where does research fit in?
PMID- 10673866
TI - Teaching and research training should be integrated with clinical training.
PMID- 10673867
TI - Cost effectiveness of general anaesthesia: inhalation vs i.v.
PMID- 10673868
TI - Less is more ... using systolic pressure variation to assess hypovolaemia.
PMID- 10673869
TI - Ventilatory frequency variability in spontaneously breathing anaesthetized
subjects.
AB - During spontaneous breathing general anaesthesia, inspiration is generally
started by a signal related to preceding cardiovascular activity. This
phenomenon, 'cardioventilatory coupling', contributes to the variation in
ventilatory frequency. However, the detailed, breath-to-breath timing
relationship between heart beat and inspiratory onset is complex, with at least
four distinct patterns (designated patterns I-IV). These coupling patterns are
defined according to the particular breath-to-breath change in: (a) entrainment
ratio and (b) coupling interval, the interval between inspiratory onset and the
preceding initiating heart beat. We have examined the relationship between
coupling and timing of breathing in adult subjects breathing spontaneously during
general anaesthesia. The heart rate-ventilatory frequency interaction was
explored by identifying the distribution of different coupling patterns in a plot
of heart rate vs ventilatory frequency (the HR/f plot) and analysing the
variation in breathing frequency during each coupling pattern by differentiating
between changes in entrainment ratio from changes in coupling interval. We
observed that: (i) coupling patterns are distributed within specific regions of
the HR/f plot; (ii) specific patterns of variation in breathing are associated
with each coupling pattern; (iii) this variation is a consequence of the balance
between changes in entrainment ratio and coupling interval; (iv) coupling was
invariably present at low breathing frequencies; and (v) the inverse non-linear
relationship between ventilatory frequency and variation is largely a consequence
of changing coupling pattern with ventilatory frequency. Coupling explains much
of the breath-to-breath variability of ventilatory frequency during anaesthesia,
and may be relevant to the phenomena of hypoventilation, central apnoea and
ventilatory arrhythmia. A hypothesis concerning the generation of coupling
patterns is presented.
PMID- 10673870
TI - A multicentre comparison of the costs of anaesthesia with sevoflurane or
propofol.
AB - Day-case anaesthesia requires rapidly eliminated anaesthetics which are
relatively expensive. This multinational, multicentre European study assessed the
relative costs of propofol or sevoflurane anaesthesia in 211 patients.
Anaesthesia was induced and maintained with propofol in group 1, with propofol
and sevoflurane in group 2, and with sevoflurane in group 3. Drug and delivery
costs were calculated in US$. Induction of anaesthesia was fastest in groups 1
and 2, although spontaneous ventilation resumed earliest in group 3. Emergence
times and times at which patients were fit for discharge were similar in all
groups. Group 2 had the lowest costs based on actual drug use (mean $14.2 (SEM
0.8) vs $18.7 (0.8) and $17.3 (0.8) in groups 1 and 3, respectively). Anaesthetic
drug wastage and disposable costs were highest in group 1 and lowest in group 3.
Consequently, total costs were highest in group 1 ($31.9 (0.9)) compared with
groups 2 ($19.7 (0.9)) and 3 ($18.8 (0.9)). Although we observed increased nausea
and vomiting in groups 2 and 3 and reduced patient satisfaction in group 3, these
differences should be balanced against the greater cost of propofol anaesthesia.
PMID- 10673871
TI - Compound A does not accumulate during closed circuit sevoflurane anaesthesia with
the Physioflex.
AB - We have investigated inspiratory and end-tidal gas composition during sevoflurane
anaesthesia in a closed circle system with continuous gas flow (70 litre min-1,
Physioflex) to determine possible accumulation of sevoflurane degradation
products. During five abdominal operations in adults lasting more than 2 h,
anaesthesia was maintained with an end-tidal concentration of 2% sevoflurane in
40% oxygen-air. The circle included an absorbing canister filled with 1 litre of
fresh soda lime. Samples were obtained at the end of an expiration from the
tracheal tube and from the inspiratory limb before, and at selected times after,
addition of sevoflurane. The temperature of soda lime was 24.7 +/- 0.7 degrees C
at the beginning and reached a maximum of 31.2 +/- 1.0 degrees C after 20-30 min,
followed by a plateau. Inspiratory compound A (CH2F-O-C(= CF2)(CF3)) 3-8 ppm was
detected after 10 min, but did not accumulate in the circle over 2 h without
flushing. Expired concentrations were consistently lower with 1.5-3 ppm
signalling absorption by patients. Calculated total amounts absorbed over 2 h
varied between 2.0 and 7.2 ppm h. Other degradation products such as compound B
or methanol were not detected. In summary, we did not detect sevoflurane
metabolites with soda lime in significant amounts during closed circle
anaesthesia with the Physioflex. The observed concentrations of compound A were
below the threshold of nephrotoxicity in rats by a factor of more than 20.
PMID- 10673872
TI - Comparison of sevoflurane-nitrous oxide and propofol-alfentanil-nitrous oxide
anaesthesia for minor gynaecological surgery.
AB - We studied 44 patients undergoing minor gynaecological surgery, anaesthetized in
random order with sevoflurane-nitrous oxide or propofol-alfentanil-nitrous oxide.
Operating conditions, recovery and postoperative nausea and vomiting (PONV) were
assessed. For postoperative analgesia, all patients were given ketoprofen 100 mg
rectally at the end of anaesthesia. Patients and gynaecologists were equally
satisfied with both anaesthetic techniques. Patients given propofol woke up (3.5
vs 6.5 min), became orientated (5.0 vs 7.5 min) and were able to walk (57 vs 69
min) significantly (P < 0.05) earlier than those given sevoflurane, but there
were no differences in times to achieve home readiness (166 vs 149 min) or in
psychomotor recovery between the two groups. Intrauterine bleeding and PONV were
more common with sevoflurane (incidence of PONV 64%) than with propofol
anaesthesia (incidence of PONV 5%). We conclude that propofol-alfentanil is
preferable to sevoflurane in ultra-short anaesthesia for minor gynaecological
surgery.
PMID- 10673873
TI - Burst suppression or isoelectric encephalogram for cerebral protection: evidence
from metabolic suppression studies.
AB - Metabolic suppression may have a role in cerebral protection. It is often assumed
that the cerebral metabolic and protective effects of qualitative burst
suppression are similar to those of the isoelectric encephalogram (EEG). We have
examined the effect of different degrees of EEG suppression on blood flow and
oxygen difference during general anaesthesia. We studied 11 patients undergoing
general anaesthesia for resection of acoustic neuromas. The study was performed
after surgery with propofol and remifentanil anaesthesia. Transcranial Doppler
ultrasonography and jugular bulb venous saturations were measured at values of
EEG suppression: 0%, 50% and 100% (isoelectric EEG). Data from nine patients were
suitable for analysis. There were no significant differences in mean arterial
pressure, heart rate or PaCO2 during EEG activity, 50% burst suppression ratio or
isoelectric EEG. There was a significant decrease in middle cerebral artery flow
velocity (vmca) with increasing EEG suppression (0% suppression, mean 38 (SEM 4)
cm s-1; 50% suppression, 29 (3) cm s-1; and 100% suppression, 24 (2) cm s-1; P <
0.05). Jugular bulb venous saturations did not change consistently with the
change in EEG activity, indicating intact flow-metabolism coupling. We conclude
that the degree of EEG suppression had a significant effect on blood flow. If
flow-metabolism coupling is maintained, the assumption that cerebral metabolism
during 50% EEG burst suppression is equivalent to isoelectric EEG may not be
justified. If cerebral protection is related to brain metabolism, then an
isoelectric EEG may give more cerebral protection than 50% burst suppression.
PMID- 10673874
TI - Benzodiazepines and postoperative cognitive dysfunction in the elderly. ISPOCD
Group. International Study of Postoperative Cognitive Dysfunction.
AB - Postoperative cognitive dysfunction (POCD) has been attributed to long-acting
sedatives. We hypothesized that diazepam and its active metabolites could be
detected in blood after surgery and correlated with POCD, 1 week after surgery in
elderly patients. We studied 35 patients, 60 yr or older, undergoing abdominal
surgery with general anaesthesia, including diazepam. Neuropsychological tests
were performed before surgery and at discharge, where blood concentrations (free
fraction) of benzodiazepines were also measured. POCD was found in 17 patients
(48.6%). Diazepam or desmethyldiazepam was detected in 34 patients; median
postoperative blood concentrations were 0.06 and 0.10 mumol kg-1, respectively.
In a multiple regression analysis considering age, duration of anaesthesia and
blood concentrations of diazepam and desmethyldiazepam, only age was found to
correlate with the composite z-score (F test, P < 0.01). The postoperative
cognitive dysfunction we found in elderly patients after operation could not be
explained by benzodiazepine concentrations detected in blood.
PMID- 10673875
TI - Midazolam premedication and thiopental induction of anaesthesia: interactions at
multiple end-points.
AB - We have studied the effects of midazolam premedication on multiple anaesthetic
end-points (hypnotic, loss of verbal contact (LVC); motor, dropping an infusion
flex or bag (DF); analgesic, loss of reaction to painful stimulation (LRP); and
EEG, attainment of burst suppression (BUR)) during induction by slow thiopental
infusion at a rate of 55 mg kg-1 h-1. Patients received midazolam 0.05 mg kg-1
i.v. (group TM, n = 12) or no midazolam (group T0, n = 13). ED50 and ED95 values
and group medians for times and doses at the end-points were measured. Midazolam
premedication reduced significantly thiopental ED50 and ED95 values at all end
points (exception for ED95 for BUR). Potentiation was greatest for the motor end
point (dropping the infusion bag (DF)) (ED95 +52%, ED50 +23%, median +39%), and
smallest for painful stimulation (LRP) (median +18%; ED50 +13%). For LRP and DF,
premedication was associated with significant, non-parallel increases in the
slope of the thiopental dose-response curves, resulting in marked potency ratio
changes from ED50 to ED95 (LRP +31%, DF +29%). There were no such increases for
LVC or BUR. The interaction between midazolam and thiopental varied with the
anaesthetic end-point and may also depend on the dose of thiopental. Our data
suggest that the mechanism of interaction between midazolam premedication and
thiopental was different for motor effects or analgesia (DF, LRP) compared with
hypnotic effects or cortical depression (LVC, BUR), in agreement with the
different central nervous system substrates underlying these distinct anaesthetic
end-points.
PMID- 10673876
TI - Use of tranexamic acid for an effective blood conservation strategy after total
knee arthroplasty.
AB - We have investigated the effect of treatment with tranexamic acid, an inhibitor
of fibrinolysis, on blood loss, blood transfusion requirements and blood
coagulation in a randomized, double-blind, placebo-controlled study of 42
patients after total knee arthroplasty. Tranexamic acid 15 mg kg-1 (n = 21) or an
equivalent volume of normal saline (n = 21) was given 30 min before surgery and
subsequently every 8 h for 3 days. Coagulation and fibrinolysis values, blood
loss and blood units administered were measured before administration of
tranexamic acid, 8 h after the end of surgery and at 24 and 72 h after operation.
Coagulation profile was examined (bleeding time, platelet count, prothrombin time
(PT), activated partial thromboplastin time (aPTT), plasminogen, beta
thromboglobulin and fibrinogen). Fibrinolysis was evaluated by measurement of
concentrations of D-dimer and fibrinogen degradation products (FDP). Total blood
loss in the tranexamic acid group was 678 (SD 352) ml compared with 1419 (607) ml
in the control group (P < 0.001), and occurred primarily during the first 24 h
after surgery. Thirteen patients received 1-5 u. of packed red blood cells in the
control group compared with two patients in the tranexamic acid group, who
received 3 u. (P < 0.001). Postoperative packed cell volume values were higher in
the tranexamic acid group despite fewer blood transfusions. Postoperative
concentrations of plasminogen were decreased significantly in the tranexamic acid
group (P < 0.001). Platelet count, PT, aPTT, bleeding time, beta-thromboglobulin,
fibrinogen and FDP concentrations did not differ between groups, but D-dimer
concentrations were increased in the control group. Thromboembolic complications
occurred in two patients in the control group compared with none in the
tranexamic acid group.
PMID- 10673877
TI - Effect of cardiopulmonary bypass on serum procalcitonin and C-reactive protein
concentrations.
AB - We have measured serum procalcitonin (PCT) concentrations after cardiac surgery
in 36 patients allocated to one of three groups: group 1, coronary artery bypass
grafting (CABG) with cardiopulmonary bypass (CPB) (n = 12); group 2, CABG without
CPB (n = 12); and group 3, valvular surgery with CPB (n = 12). Serum PCT and C
reactive protein (CRP) concentrations were measured before operation, at the end
of surgery and daily until postoperative day 8. Serum PCT concentrations
increased, irrespective of the type of cardiac surgery, with maximum
concentrations on day 1: mean 1.3 (SD 1.8), 1.1 (1.2) and 1.4 (1.2) ng ml-1 in
groups 1, 2 and 3, respectively (ns). Serum PCT concentrations remained less than
5 ng ml-1 in all patients. Concentrations returned to normal by day 5 in all
groups. To determine the effect of the systemic inflammatory response (SIRS) on
serum PCT concentrations, patients were divided post hoc, without considering the
type of cardiac surgery, into patients with SIRS (n = 19) and those without SIRS
(n = 17). The increase in serum PCT was significantly greater in SIRS (peak PCT
1.79 (1.64) ng ml-1 vs 0.34 (0.32) ng ml-1 in patients without SIRS) (P = 0.005).
Samples for PCT and CRP measurements were obtained from 10 other patients with
postoperative complications (circulatory failure n = 7; active endocarditis n =
2; septic shock n = 1). In these patients, serum PCT concentrations ranged from
6.2 to 230 ng ml-1. Serum CRP concentrations increased in all patients, with no
differences between groups. The postoperative increase in CRP lasted longer than
that of PCT. We conclude that SIRS induced by cardiac surgery, with and without
CPB, influenced serum PCT concentrations with a moderate and transient
postoperative peak on the first day after operation. A postoperative serum PCT
concentration of more than 5 ng ml-1 is highly suggestive of a postoperative
complication.
PMID- 10673878
TI - Effect of tropisetron on vomiting during patient-controlled analgesia in
children.
AB - Patient-controlled analgesia (PCA) is associated with a high incidence of
vomiting which is distressing and interferes with postoperative recovery.
Tropisetron, a long-acting selective 5-HT3 receptor antagonist, has been shown to
be effective in preventing nausea and vomiting associated with PCA use in adults
and chemotherapy in children. We assessed the efficacy of prophylactic
intraoperative administration of tropisetron on the incidence of vomiting in
children using morphine PCA. We studied 58 patients, allocated randomly to
receive tropisetron 0.1 mg kg-1 to a maximum of 5 mg, or normal saline. Children
who received tropisetron had an incidence of vomiting during the first 24 h after
operation of 22% compared with 66% in the control group (P = 0.001). In addition,
the severity of vomiting was less in the tropisetron group with only one child
(4%) vomiting more than twice compared with nine (31%) in the control group (P =
0.01). We conclude that tropisetron is efficacious in reducing the incidence and
severity of postoperative vomiting in children using PCA.
PMID- 10673879
TI - Comparison of ondansetron and cyclizine for prevention of nausea and vomiting
after day-case gynaecological laparoscopy.
AB - We have compared ondansetron 4 mg i.v. and cyclizine 50 mg i.v., in a double
blind, randomized, placebo-controlled study for the prevention of postoperative
nausea and vomiting (PONV) for 24 h after day-case gynaecological laparoscopy.
Compared with placebo (n = 58), ondansetron (n = 60) and cyclizine (n = 57)
reduced significantly the incidence of moderate or severe nausea (30% and 23% vs
52%; P = 0.02 and P = 0.001, respectively) and requirement for escape antiemetic
(28% and 16% vs 47%; P = 0.04 and P < 0.001, respectively) before discharge from
hospital. There were no significant differences in PONV after discharge.
Significantly more patients suffered no PONV before and after discharge after
ondansetron and cyclizine compared with placebo (31% and 33% vs 12%; P = 0.02 and
P < 0.01, respectively). For diagnostic laparoscopy (n = 74), fewer patients
received escape antiemetic after cyclizine than after ondansetron (4% vs 37%; P <
0.01); for laparoscopic sterilization (n = 101), both antiemetics were equally
effective. Ondansetron and cyclizine both reduced severe and moderate nausea and
the need for antiemetic therapy after day-case gynaecological laparoscopy.
PMID- 10673880
TI - The intubating laryngeal mask airway compared with direct laryngoscopy.
AB - We have compared the ability of naive intubators to intubate the trachea using a
laryngoscope and an intubating laryngeal mask airway (ILMA) after receiving basic
training, in a randomized, prospective, crossover study in 60 patients.
Ventilation of the lungs via the ILMA was also compared with ventilation with a
face mask. There was no significant difference in successful intubation between
the techniques (38 of 89 with the ILMA and 33 of 93 with direct laryngoscopy;
ns). In patients in whom participants failed in their intubation attempts with
the ILMA, investigators achieved success in 89% (16 of 18). Satisfactory
ventilation was more common with the ILMA (50 of 51) than with the face mask (43
of 60) (P = 0.0001). A total of 98% (89 of 91) of ILMA were inserted
successfully, with a mean insertion time of 19.6 s, and 78% (69/89) of these
insertions were achieved in less than 26 s. The ILMA may be useful for emergency
oxygenation and ventilation, but these results do not support its use for
intubation by those not trained in advanced airway management and ILMA use.
PMID- 10673881
TI - Arterial to inspired partial pressure ratio of halothane, isoflurane, sevoflurane
and desflurane in rats.
AB - The inspired partial pressure of an anaesthetic is often used as an index of
arterial partial pressure in small animal experiments. We have investigated the
influence of anaesthetic solubility on the ratio of arterial to inspired partial
pressure in 24 rats, allocated randomly to receive halothane, isoflurane or
desflurane at four different inspired concentrations. The arterial partial
pressure of the volatile agent was measured by two-stage headspace analysis using
a gas chromatograph calibrated with the same gas used to calibrate the Datex
Capnomac that measured the inspired concentration. Mean values of arterial to
inspired ratio at the lowest concentrations were 0.60 (95% confidence intervals
0.50, 0.71) for 0.8% halothane, 0.54 (0.38, 0.69) for 0.8% isoflurane, 0.72
(0.59, 0.86) for 1.5% sevoflurane and 0.71 (0.54, 0.87) for 4% desflurane.
Analysis of variance showed a significant effect of anaesthetic agent (P = 0.008)
on the arterial to inspired ratio. Thus volatile anaesthetic agents do not
demonstrate a fixed arterial to inspired ratio in rats.
PMID- 10673882
TI - Effects of propofol on vascular reactivity in isolated aortae from normotensive
and spontaneously hypertensive rats.
AB - We have investigated the effects of propofol 50 mumol litre-1 on contractile and
relaxant responses in experimental hypertension and assessed endothelial
modulation of these responses. Propofol attenuated norepinephrine-induced
contraction of endothelium-intact and endothelium-denuded rings from both Wistar
Tokyo (WKY) and spontaneously hypertensive rats (SHR). The effect was
significantly greater in endothelium-intact aortae from SHR than in those from
WKY rats. Propofol markedly attenuated AVP-induced contraction in aortae from
both WKY and SHR. Propofol attenuation of norepinephrine contraction was also
observed in rings from both SHR and WKY rats incubated with L-NAME. Propofol
attenuation of norepinephrine contraction was suppressed by indomethacin in
aortae from SHR but not in those from WKY rats. These results suggest that: (1)
propofol attenuated vascular contraction of isolated aortae from SHR in part by a
mechanism dependent on events distal to the receptor site (norepinephrine,
arginine vasopressin); (2) the effect of propofol on contraction in SHR, observed
in the presence of nitric oxide synthase inhibitors but not cyclooxygenase
inhibitors, was consistent with either propofol induction of vasodilating
cyclooxygenase metabolites from the endothelium or propofol inhibition of
vasoconstricting cyclooxygenase metabolites.
PMID- 10673883
TI - Measurements of systolic time intervals using a transoesophageal pulsed echo
Doppler.
AB - Measurement of systolic time intervals (STI), an index of left ventricular (LV)
systolic function, is usually labour intensive and requires considerable
expertise to perform accurately. We have evaluated the accuracy of an automated,
continuous and non-invasive STI measurement technique using a descending aortic
blood velocity Doppler signal obtained using a transoesophageal echo-Doppler
system (TEDS) and an ECG signal. STI were measured in adult pigs using a
transoesophageal probe (4 x 4 mm pulsed wave Doppler transducer, 5-MHz frequency
and a 3 x 3 mm echo transducer, 10-MHz frequency) associated with an ECG
recorder. Measurements were performed at baseline and after injection of esmolol
and dobutamine. TEDS data were compared with those obtained by one-line
recordings of the electrocardiogram and the central aortic arterial pressure
wave. Similar mean values were observed for pre-ejection period (PEPI), LV
ejection time (LVET) and PEP/LVET with the two methods. Agreement between the
methods (Bland and Altman's test) was excellent with 95% confidence intervals for
PEP, LVET and PEP/LVET of -7.17 to +1.37 ms, -12.64 to +0.24 ms and -0.033 to
+0.028, respectively. We conclude that the combination of descending aorta blood
velocity Doppler and ECG signal is an alternative technique for non-invasive and
objective measurement of STI, allowing continuous monitoring of LV systolic
function.
PMID- 10673884
TI - Adverse effects of cannabis and cannabinoids.
PMID- 10673885
TI - Comparison of breathing methods for inhalation induction of anaesthesia.
AB - We studied healthy female patients, allocated randomly to three breathing
regimens for induction of anaesthesia using sevoflurane and oxygen from a co
axial Mapleson D breathing system and a mask, to test the hypothesis that
rebreathing reduces the incidence of apnoea associated with loss of
consciousness. The non-rebreathing group received sevoflurane in oxygen 6 litre
min-1 from the start, doubling in concentration from 0.5% to 8% every 3 breaths.
The second group received oxygen 6 litre min-1 for 1 min before sevoflurane was
introduced, and the third group received oxygen 3 litre min-1 for 1 min before
sevoflurane. The incidence and duration of apnoea were assessed using
pneumotachograph and impedance pneumograph recordings, and time to induction of
anaesthesia (weight drop) was measured from the time the breathing sequence was
started. There was no difference in these times, which were mean 121 (95%
confidence values 91-160) s, 117 (69-201) s and 125 (76-192) s, respectively.
There was a significant difference in the incidence of apnoea. No apnoea occurred
during induction using oxygen 3 litre min-1. Apnoea occurred in five of 15
patients who did not receive oxygen before sevoflurane and in four of 13 who
received oxygen 6 litre min-1 (P < 0.05). No patient showed a reduction in pulse
oximeter saturation. We conclude that inhalation induction of anaesthesia can be
performed reliably in approximately 3 min using sevoflurane in oxygen 3 litre min
1.
PMID- 10673886
TI - Effect of a remifentanil bolus dose on the cardiovascular response to emergence
from anaesthesia and tracheal extubation.
AB - We have examined the effect of remifentanil on the haemodynamic response to
emergence from anaesthesia and tracheal extubation in 40 ASA I-II female patients
undergoing diagnostic laparoscopy, in a randomized, double-blind study. All
patients received a standard general anaesthetic comprising propofol, vecuronium
and 1% isoflurane with 66% nitrous oxide in oxygen. At the end of surgery, a
bolus dose of remifentanil 1 microgram kg-1 (n = 20) or saline placebo (n = 20)
was given and tracheal extubation was performed when standard criteria were
achieved. Arterial pressure and heart rate were recorded non-invasively at 1-min
intervals from the end of surgery. Remifentanil attenuated the increase in both
mean arterial pressure (P < 0.001) and heart rate (P < 0.05) at extubation. Mean
time to extubation was 7.2 (SEM 0.6) min and 4.0 (0.5) min in the remifentanil
and saline groups, respectively (P < 0.001). There was no difference in the
incidence of coughing at extubation, time to recovery from anaesthesia or time to
fitness for discharge from the recovery room.
PMID- 10673887
TI - Bacterial contamination of needles used for spinal and epidural anaesthesia.
AB - We have investigated prospectively the incidence of bacterial contamination of
114 spinal and 20 epidural needles collected immediately after lumbar puncture of
the subarachnoid or epidural space. Bacteriological examination revealed
bacterial contamination of 24 (17.9%) of the needles, mainly coagulase-negative
staphylococci (21; 15.7%) followed by yeasts (2; 1.5%), enterococcus (1; 0.8%),
pneumococcus (1; 0.8%) and micrococcus (1; 0.8%). Our results suggest that even
during aseptic puncture for lumbar anaesthesia, there is a significant rate of
needle contamination.
PMID- 10673888
TI - Effect of itraconazole on the pharmacokinetics of bupivacaine enantiomers in
healthy volunteers.
AB - We studied seven healthy volunteers given itraconazole 200 mg orally or placebo,
once daily for 4 days, in a crossover study. On day 4, racemic bupivacaine 0.3 mg
kg-1 was given i.v. over 60 min and venous plasma samples were collected for 23
h. Plasma concentrations of R- and S-bupivacaine, itraconazole and
hydroxyitraconazole were measured. Itraconazole reduced the clearance of R
bupivacaine by 21% (P < 0.05) and that of S-bupivacaine by 25% (P < 0.05), while
it had no significant effect on other pharmacokinetic variables of the
enantiomers. Reduction of bupivacaine clearance by itraconazole probably
increases the steady-state concentration of bupivacaine enantiomers by 20-25%.
This should be taken into account in the concomitant use of bupivacaine and
itraconazole, although the interaction seems to be of limited clinical
significance.
PMID- 10673889
TI - Sensory hyperinnervation after neonatal skin wounding: effect of bupivacaine
sciatic nerve block.
AB - The response to tissue injury includes sensitization of peripheral nociceptors
and central neuronal pathways leading to acute clinical and inflammatory pain. A
further response is sprouting of sensory nerve terminals in the region of skin
damage. This hyperinnervation response is particularly intense in neonates
compared with adults. In this study, we tested the effect of regional nerve block
at the time of injury on skin hyperinnervation. Anaesthetized newborn rat pups
were treated with percutaneous sciatic nerve block injections of 0.25%
bupivacaine 25 microliters followed by a localized hindpaw skin wound. Cutaneous
innervation was studied by image analysis of immunostained skin sections, 7 days
after wounding, and sensory thresholds were assessed using von Frey hairs. The
results showed that both hyperinnervation and hypersensitivity were not
significantly altered by the application of a regional nerve block at the time of
injury. This suggests that regional analgesia, used commonly in clinical
practice, is unlikely to prevent the hyperinnervation that follows skin wounding.
PMID- 10673890
TI - Propofol anaesthesia in mice is potentiated by muscimol and reversed by
bicuculline.
AB - We have examined the role of gamma-aminobutyric acid (GABA) neurones in propofol
anaesthesia in mice using the righting reflex. Propofol i.p. increased the
percentage of loss of the righting reflex in a dose-dependent manner with an ED50
value of 140 (95% confidence limits 123-160) mg kg-1 (n = 40; eight animals per
dose, five doses per dose-response curve). The ED50 for propofol decreased
significantly to 66 (58-75) mg kg-1 in the presence of the GABAA receptor agonist
muscimol 1 mg kg-1 i.p. (n = 40) (P < 0.05). In contrast, the ED50 increased
significantly to 240 (211-274) mg kg-1 in the presence of the antagonist
bicuculline 5 mg kg-1 i.p. (n = 40) (P < 0.05). Our results suggest that propofol
anaesthesia may be mediated, at least in part by GABA neurons.
PMID- 10673891
TI - Pulmonary haemorrhage after percutaneous paravertebral block.
AB - We describe the management of a 65-yr-old woman anaesthetized for thoracotomy.
The patient suffered a pulmonary haemorrhage after percutaneous paravertebral
injection performed using the loss of resistance to saline technique. Thoracotomy
at a later date revealed that the lung tissue had become adherent to the chest
wall and that the paravertebral space was fibrosed secondary to previous surgery.
This particular complication of percutaneous paravertebral block has not been
reported previously and raises the question of risk vs benefit of this pre
emptive analgesic technique.
PMID- 10673892
TI - Combined spinal-epidural in the obstetric patient with Harrington rods assisted
by ultrasonography.
AB - We describe a patient with severe scoliosis, which had been corrected partially
with Harrington rods, who requested epidural analgesia for labour. With no
palpable landmarks, the use of ultrasound enabled identification of the vertebral
midline and allowed provision of regional anaesthesia.
PMID- 10673893
TI - Ropivacaine and bupivacaine for long-term epidural infusion in a small child.
AB - Ropivacaine is assumed to be less toxic than bupivacaine but there are no reports
concerning its long-term use in paediatric anaesthesia. We report the use of
ropivacaine for long-term epidural anaesthesia in a 21-month-old girl. In two
consecutive periods of 3 days each, 0.5% bupivacaine and 0.5% or 0.75%
ropivacaine were administered to facilitate painful vaginal brachytherapy. The
mean dose of bupivacaine increased from 1.05 to 1.32 mg kg-1 h-1 and that of
ropivacaine increased from 1.40 to 3.86 mg kg-1 h-1. No toxic side effects were
observed. We conclude that both epidural ropivacaine and bupivacaine were
effective and safe during long-term epidural anaesthesia in this particular case.
However, the doses were potentially toxic and should therefore be used with
extreme caution.
PMID- 10673894
TI - A rough guide to molecular biology.
PMID- 10673895
TI - Hypoxia caused by a faulty Steri-cath closed suction device and use of continuous
suction.
PMID- 10673896
TI - Placement of double-lumen endobronchial tubes.
PMID- 10673897
TI - Fibreoptic orotracheal intubation.
PMID- 10673898
TI - Is anaesthesia evidence-based?
PMID- 10673899
TI - Do not rely on a laryngeal mask in major periglottic pathology.
PMID- 10673900
TI - EEG indices and heart rate variability as measures of depth of anaesthesia.
PMID- 10673901
TI - Regional anaesthesia for carotid endarterectomy.
PMID- 10673902
TI - Regional anaesthesia for carotid endarterectomy.
PMID- 10673903
TI - Central nerve block and thromboprophylaxis.
PMID- 10673904
TI - Human milk oligosaccharides: 130 reasons to breast-feed.
PMID- 10673905
TI - Dietary fatty acids and atherosclerosis regression.
PMID- 10673906
TI - The control of partitioning between protein and fat during human starvation: its
internal determinants and biological significance.
AB - Human subjects vary in the extent to which their body's protein and fat
compartments are mobilized for fuel during starvation. Although an inverse
association between the initial adiposity and the contribution of protein as fuel
during starvation has been known for nearly a century, interest in the
quantitative importance and functional significance of the initial percentage fat
as a determinant of biological variation in energy-partitioning between protein
and fat (and hence in determining the partitioning characteristic of the
individual) is relatively recent. The present paper addresses these issues by
revisiting the classic Minnesota experiment of semi-starvation and refeeding from
a standpoint of system physiology. In a quantitative analysis of the relationship
between the initial body composition (ration FAT0: fat-free mass (FFM)0) and the
composition of weight loss (ratio delta FAT: delta FFM) in the thirty-two men in
the Minnesota study, the arguments are put forward that the fraction of FFM lost
when the fat stores reach total depletion is independent of the initial
percentage fat, and that this fraction represents the 'dispensable' component of
the protein compartment that is compatible with life (i.e. the protein energy
reserve, rp). The concepts are developed that (1) the initial percentage body fat
(which reflects the initial ratio FAT0:FFM0) provides a 'memory of partitioning'
which dictates the control of partitioning between protein and fat in such a way
that both the protein energy-reserve (rp) and the fat energy-reserve (rf) each
complete depletion simultaneously, a strategy that would ensure maximum length of
survival during long-term food scarcity, and that (2) variability in the relative
sizes of these two energy reserves (i.e. in rf:rp) could, in addition to the
initial percentage fat, also contribute to human variability in energy
partitioning. The basic assumptions underlying this re-analysis of the Minnesota
data, and the concepts that are derived from it, have been integrated in the
simple mathematical model for predicting the partitioning characteristic of the
individual. This model is used to explain how variability in the fraction of the
protein compartment that could function as an energy reserve (rp) can be as
important as the initial percentage fat in determining inter-individual
variability in protein-sparing during the early phase of starvation, in fuel
partitioning during prolonged starvation, or in the maximum percentage weight
loss during starvation. The elucidation of factors underlying variability in the
size of the protein energy-reserve may have important implications for our
understanding of the pathophysiology of starvation and age-associated
susceptibility to muscle wasting, and in the clinical management of cachexia and
obesity.
PMID- 10673907
TI - Selenium supplementation affects the retention of stable isotopes of selenium in
human subjects consuming diets low in selenium.
AB - Twenty-nine women and fifteen men from an area of low Se intake (South Island of
New Zealand) consumed 100 micrograms stable 74Se, as selenate given in water
after an overnight fast, and blood was collected for 3 weeks. They were then
divided into five groups and supplemented with 0, 10, 20, 30 and 40 micrograms
Se/d (as selenomethionine) for 5 months. After 5 months, they received a second
dose of 74Se identical to the first. Supplementation significantly altered
retention of 74Se in the plasma, but not in the erythrocytes or platelets.
Subjects receiving the placebo retained the greatest amount, and subjects
receiving 30 micrograms supplemental Se/d retained the least 74Se.
Supplementation resulted in relatively more isotope being retained in a medium
molecular mass protein considered to be albumin, and relatively less in another
fraction considered to be selenoprotein P. The lack of many observed changes in
retention of stable Se, and the shift in retention among the plasma proteins,
suggests that supplemental Se was not being used to replete critical pools of Se,
probably because of adaptation to low Se intake.
PMID- 10673908
TI - Neutral oligosaccharide content of preterm human milk.
AB - Human milk oligosaccharides are known to play a role in protection against
certain infectious diseases. Previous reports indicate that the content of human
milk oligosaccharides varies widely among individuals at term but such
information on preterm milk is lacking. After removal of the fat, protein and
most of the lactose from non-pooled human milk samples, a total neutral
oligosaccharide fraction was isolated by ion-exchange chromatography followed by
gel filtration. A Dionex high-performance anion-exchange chromatography system
equipped with a pulsed electrometric detector was then employed to measure the
levels of ten neutral oligosaccharides in the individual milk samples. Twenty
three milk samples from thirteen mothers who delivered at a mean gestational age
of 29.5 (SD 3.1) weeks were collected between days 0 and 33 of lactation, and
compared with three samples of term milk from two mothers. The ranges of the
total and individual levels of the ten neutral oligosaccharides in preterm milk
were similar to those in term milk. Further, as previously described in term
milk, preterm milk exhibited a quantitative individual variation. This variation
was independent of the gestational age, day of lactation, and postconceptional
age. In conclusion, levels of ten neutral oligosaccharides did not differ between
preterm and term human milk.
PMID- 10673909
TI - Dietary and socio-economic factors associated with obesity among Kuwaiti college
men.
AB - Obesity has been on the increase among people of the Arabian Gulf countries.
Overweight and obesity among 18-29-year-old Kuwaiti men increased by 23.4 and
14.8% respectively, between 1980 and 1993. The objective of the present study was
to explore factors associated with overweight and obesity in a sample of 515
Kuwaiti college men studied in 1997. Weight and height were measured. The index
of adiposity used was the BMI, which is the weight (kg) divided by the height (m)
squared (kg/m2). The men were classified as overweight (BMI > 25 kg/m2) or obese
(BMI > 30 kg/m2). The associated factors obtained through questionnaires included
age, marital status, governorate, number of siblings, suffering from a chronic
disease, subjects' parental obesity, education and occupation, number of major
meals eaten, eating between meals, family income, number of servants, number of
people living at home, exercising, last dental and physical check-up, dieting,
year of study, highest desired degree after college, countries preferred for
visiting, and socio-economic status. The results of the study revealed that 38.5
and 11.1% of the students were overweight and obese respectively. Factors that
were found to be significantly associated with overweight and obesity among the
men included age, marital status, last dental check-up, exercising, subjects'
parental obesity, dieting and year of study. Logistic regression analysis of
significant associated factors revealed that the same factors contributed to the
development of overweight and obesity.
PMID- 10673910
TI - Effects of inulin on faecal bifidobacteria in human subjects.
AB - A controlled study with eight healthy free-living subjects was carried out, in
which energy intake was adjusted to the individual energy requirements. On
administration of inulin, blood lipids, the faecal microflora, short-chain fatty
acids and accompanying gastrointestinal symptoms were characterized in order to
investigate the long-term effect of inulin. During the run-in phase (8 d),
subjects received a typical Western diet providing 45% energy as fat and 40%
energy as carbohydrate. Subsequently, the subjects consumed a fat-reduced diet
which provided 30% energy as fat and 55% energy as carbohydrate for a period of
64 d using inulin as a fat replacer. The amounts of inulin consumed by the
subjects (up to 34 g/d) were based on individual energy requirements with the aim
to keep the diet isoenergetic with that used in the run-in period. To assess the
effects of inulin administration, a control study (run-in and intervention) was
carried out in which subjects consumed the same diet but devoid of inulin during
the whole course of the study. To investigate the effect of inulin on faecal
flora composition total bacteria and bifidobacteria in the faeces were enumerated
by in situ hybridization with 16S rRNA targeted oligonucleotide probes. Inulin
significantly increased bifidobacteria from 9.8 to 11.0 log10/g dry faeces and
caused a moderate increase in gastrointestinal symptoms such as flatulence and
bloatedness, whereas blood lipids and short-chain fatty acids remained
essentially unaffected.
PMID- 10673911
TI - Modulation of human T-lymphocyte functions by the consumption of carotenoid-rich
vegetables.
AB - A human intervention study was conducted to determine the effect of the
consumption of carotenoid-rich vegetables on the immune system. Subjects, (twenty
three men), who were non-smokers, were not restricted in their daily diet, except
that they had to abstain from fruit and vegetables high in carotenoids throughout
the whole study period. The study was divided into four periods, each lasting 2
weeks: weeks 1-2: low-carotenoid period; throughout weeks 3-8: daily consumption
of 330 ml tomato juice (40 mg lycopene/d, 1.5 mg beta-carotene/d) (weeks 3-4),
330 ml carrot juice (21.6 mg beta-carotene/d, 15.7 mg alpha-carotene/d, 0.5 mg
lutein/d) (weeks 5-6), 10 g dried spinach powder (11.3 mg lutein/d, 3.1 mg beta
carotene/d) (weeks 7-8). Blood was collected weekly from subjects after a 12 h
fast. T-lymphocyte functions were assessed by measuring proliferation and
secretion of immunoreactive cytokines. The consumption of a low-carotenoid diet
resulted in a significantly reduced proliferation of peripheral blood mononuclear
cells (PBMC) cultured with concanavalin A. After 2 weeks of tomato juice
consumption and until the end of the intervention period lymphocyte proliferation
was not significantly changed compared with proliferation at the end of the
depletion period. Secretion of cytokines by T-helper-1-like lymphocytes
(interleukin (IL)-2) and by T-helper-2-like lymphocytes (IL-4) was influenced by
the dietary intervention. IL-2 and IL-4 secretion values were significantly
suppressed after the low-carotenoid diet (P < 0.001 and P < 0.05 respectively
compared with baseline). Tomato juice consumption significantly enhanced IL-2 (P
< 0.001) and IL-4 secretion (P < 0.05) compared with the end of depletion period.
After carrot juice and spinach powder consumption the cytokine secretion capacity
of PBMC was not significantly different from that at the end of the depletion
period. In conclusion, the results of the present study indicate that a low
carotenoid diet reduces T-lymphocyte functions and addition of tomato juice
restores these functions. This modulation could not be explained by changes in
the plasma carotenoid concentrations. The active constituents in tomato juice as
well as the biological significance of this immunomodulation remain to be
determined.
PMID- 10673912
TI - Lactose-derived oligosaccharides in the milk of elephants: comparison with human
milk.
AB - Human milk is commonly considered to be unique when compared with the milk of
other species with regard to its high content of complex fucosylated and
sialylated lactose-derived oligosaccharides. We describe the application of high
pH anion-exchange chromatography with pulsed amperometric detection and TLC to
characterize and quantitate neutral and sialylated lactose-derived
oligosaccharides in milk from three Asian elephants and human milk. The lactose
contents of elephant and human milks were 25-30 g/l and about 66 g/l
respectively, whereas total oligosaccharide concentration was about three times
higher in elephant milk and comprised up to 40% (10% in human milk) of the
carbohydrate content. The ratio neutral: acidic components was different in the
milk of the two species; in elephant milk, the N-acetylneuraminic acid-containing
oligosaccharides made up almost half of the total amount v. 30% in human milk.
Most oligosaccharides in elephant milk were more fucosylated and/or sialylated
compared with human milk components. By mild acid hydrolysis, fucose and N
acetylneuraminic acid were cleaved off from complex components, and this resulted
in increased amounts of fucose, galactose, N-acetylneuraminic acid, lactose and
lacto-N-neo-tetraose. Unique to elephant milk are the high levels of 3'
galactosyllactose (up to 4 g/l) and lacto-N-neo-tetraose which are present in
human milk only in trace amounts. Elephant and human milks have high levels and
unique patterns of oligosaccharides which may reflect the relative importance of
these components in neonatal host defence, in endothelial leucocyte interactions
or in brain development.
PMID- 10673914
TI - Phospholipid fatty acid composition and protein kinase C activity in the large
intestine of rats fed on butter and coconut-oil diets.
AB - Protein kinase C (PKC) has been proposed to play an important role in the
aetiology of colon cancer. Therefore, we investigated whether the amount and type
of saturated fat could affect colonic PKC activity by modifying either mucosal
phospholipid fatty acid composition or faecal diacylglycerol production. Male
Wistar rats (n 13 per group) were fed on diets containing butter or coconut oil
at energy levels of 10% and 43% for 4 weeks. The control group received a low-fat
diet providing 10% of energy from sunflowerseed oil. PKC activity was higher in
the distal than the proximal colon but the quantity or type of fat did not alter
PKC activity in either region of the colon. Saturated fats caused moderate
changes in the fatty acid composition of caecal phospholipids, which were more
obvious in the phosphatidylethanolamine than in the phosphatidylcholine fraction.
A significant correlation was found between fatty acid composition of
phosphatidylcholine and membrane PKC activity. In particular, there was a
positive correlation between the proportion of saturated 14:0 and 18:0 and
increased PKC activity while unsaturated 18:2n-6, 20:4n-6 and 16:1n-7 were
inversely correlated with PKC activity. No relationship was found between
phosphatidylethanolamine fatty acids and PKC activity. Concentration of faecal
diacylglycerol was not affected by the diet. Overall the data suggest that diets
high in saturated fat may not alter colonic PKC activity to a significant extent.
PMID- 10673913
TI - Modulation of the regression of atherosclerosis in the hamster by dietary lipids:
comparison of coconut oil and olive oil.
AB - The Golden Syrian hamster (Mesocricetus auratus) has been shown to be a useful
model of both human lipoprotein metabolism and the development of
atherosclerosis. We report the effects of dietary lipids on the progression and
regression of atherosclerosis in this model. In the first study, hamsters fed on
coconut oil (150 g/kg diet) and cholesterol (30 g/kg diet) developed lipid-rich
lesions in the ascending aorta (0.28 (SD 0.14) mm2) and aortic arch (0.01 (SD
0.01) mm2) after 4 weeks that continued to progress over the next 8 weeks (0.75
(SD 0.41) mm2 and 0.12 (SD 0.11) mm2 for the ascending aorta and aortic arch
respectively). Removal of cholesterol from the diet halted this progression.
Furthermore, in animals fed on olive oil in the absence of added cholesterol,
plasma LDL-cholesterol concentrations were lower (P < 0.05) and the extent of
atherosclerotic lesions was reduced (P < 0.001 for both regions of the aorta)
compared with animals fed on coconut oil (with no added cholesterol). In a second
study, animals were fed on the atherogenic diet for 10 weeks, transferred to
diets containing either coconut oil (150 g/kg diet) or olive oil (150 g/kg diet)
without added cholesterol and monitored for up to 16 weeks. In the ascending
aorta, lesion size doubled in animals fed on coconut oil but stabilized in those
fed on olive oil. In the aortic arch, lesion size decreased linearly (P < 0.05, P
< 0.001 for coconut oil and olive oil respectively) with the greatest reduction
being seen in the olive-oil-fed animals (P < 0.05). Again, progression and
regression of atherosclerosis appeared to reflect the relative concentrations of
LDL-cholesterol and HDL-cholesterol in the plasma. We conclude that the male
Golden Syrian hamster represents a useful model of dietary induced regression as
well as progression of atherosclerosis.
PMID- 10673915
TI - Enhancement of butyrate production in the rat caecocolonic tract by long-term
ingestion of resistant potato starch.
AB - Some data suggest that the colonic microflora may adapt to produce more butyrate
if given time and the proper substrate. To test this hypothesis, we investigated
the effect of prolonged feeding of resistant potato starch on butyrate
production. Rats were fed on either a low-fibre diet (basal) or the same diet
supplemented with 90 g resistant potato starch/kg (PoS) for 0.5, 2 and 6 months.
Short-chain fatty acid (SCFA) concentrations were determined in caecal and
colonic contents at the end of each ingestion period. Total SCFA concentration
increased over time throughout the caecocolonic tract with PoS, but was not
modified with the basal diet. While propionate concentration was unchanged,
butyrate concentration was highly increased by PoS at each time period in both
the caecum and colon. Moreover, the butyrogenic effect of PoS increased over
time, and the amount of butyrate was increased 6-fold in the caecum and proximal
colon and 3-fold in the distal colon after 6 months compared with 0.5 months.
Accordingly, the ratio butyrate:- total SCFA increased over time throughout the
caecocolonic tract (12.6 (SE 2.8) v. 28 (SE 1.8)% in the caecum, 10.5 (SE 1.4) v.
26.8 (SE 0.9)% in the proximal colon, and 7.3 (SE 2.4) v. 23.9 (SE 2.7)% in the
distal colon at 0.5 v. 6 months respectively), while the proportion of acetate
decreased. Neither the proportion nor the concentration of butyrate was modified
over time with the basal diet. Butyrate production was thus promoted by long-term
ingestion of PoS, from the caecum towards the distal colon, which suggests that a
slow adaptive process occurs within the digestive tract in response to a chronic
load of indigestible carbohydrates.
PMID- 10673916
TI - Oromandibular reconstruction using a third free flap in sequence in recurrent
carcinoma.
AB - Successful results of a second microsurgical reconstructive attempt have been
reported previously in recurrent oral carcinoma. However, the feasibility of a
third free flap following a third excision has remained to be determined. Six
oral carcinoma patients with multiple recurrences, surgical excisions and free
flap reconstructions on three separate occasions are presented. Resections had a
curative intent in all cases in the first and second ablations and in four of the
six cases in the third one. Five radial forearm flaps and one double free flap
were used for the first reconstruction. During the second reconstruction two
radial forearm, two fibula osteoseptocutaneous, one double free flap and one
rectus femoris flap were used to reconstruct the larger defects resulting from
excision of the recurrent tumours. However, no vascularised bone transfers were
performed following the third excision and soft tissue free flap plus plate
option was used for segmental mandibular defects. There was one partial flap loss
among 21 free flaps performed. Three patients died within an average of 8 months
following the third reconstruction while the others remained alive, surviving an
average of 6 months. In conclusion, a third free tissue transfer for
reconstruction in multiply recurrent oral carcinoma was found to be feasible,
safe and effective. The use of free flaps contributed to the prevention of
complications in these difficult cases and enabled the patients to spend the
remaining days of their lives outside hospital.
PMID- 10673917
TI - Expression of growth factors in the mandibular distraction zone: a sheep study.
AB - Interest in craniofacial osteodistraction has increased in recent years parallel
with the growing attention given to the role of growth factors in tissue healing
and regeneration. This study was embarked upon to investigate the expression of
bFGF, TGF-beta and IGF-1 in the distraction zone of the mandible. Fourteen
growing sheep were allocated to three experimental groups. Six animals were
allocated to Groups A and B (n = 12) and underwent bilateral mandibular
corticotomies with fixation of an external lengthening device. The distraction
protocol consisted of a rate of 1.0 mm/day (twice daily) for 20 days followed by
a consolidation phase of 20 days after which the sheep were sacrificed. Group C
comprised of age matched sham operated animals (n = 2). Bone histochemistry for
growth factors were performed in the harvested mandibles. A strong staining of
bFGF was seen in the osteoblasts, osteocytes and osteoid matrix following 20 days
of distraction and 20 days of consolidation compared to the control group. TGF
beta and IGF-1 demonstrated mild but clear staining in osteocyte and osteoblast
cells and TGF-beta stained positively in the osteoid seam in the experimental
groups. These finding suggest that bFGF, IGF-1 and TGF-beta may play different
roles in the remodelling phase of distraction osteogenesis.
PMID- 10673918
TI - Analysis of flow changes in forearm arteries after raising the radial forearm
flap: a prospective study using colour duplex imaging.
AB - The purpose of this study is to assess the changes in flow patterns of forearm
arteries produced by excision of the radial artery when harvesting the radial
forearm flap, in order to clarify its vascular morbidity rationally. Eleven
patients with elective surgery using the radial flap were included in this
investigation. A prospective study was designed using colour duplex imaging for
quantitative flow measurement in two stages: a few days before the operation, a
first colour duplex scanning examination was done recording flow velocity and
vessel section area from the radial, ulnar, posterior interosseous and anterior
interosseous arteries around the wrist. Volumetric parameters and relative blood
flow percentages were calculated and compared to those obtained from a second
similar vascular investigation accomplished in the same limb 4-5 months after the
operation. Statistical analysis was done using the Wilcoxon matched pairs test.
After raising the radial forearm flap there was a trend for increased overall
forearm flow (from 162 to 215 ml/min, P = 0.09 N.S.), the ulnar (P = 0.04), the
posterior interosseous (P = 0.004) and the anterior interosseous (P = 0.003)
arteries being responsible for this tendency. The anterior interosseous artery
showed the greatest increase in blood (from 8.2 to 67.7 ml/min), reaching a
relative flow percentage (33%) close to that of the radial artery before its
excision (39%). Results of this study indicate that another 'major vascular axis'
based on the anterior interosseous artery develops after sacrificing the radial
artery and that global arterial inflow to the hand is not impaired.
PMID- 10673919
TI - Reduction of potential contamination of breast implants by the use of 'nipple
shields'.
AB - Forty-three breast implant operations in 25 patients were studied prospectively
to determine the effectiveness of covering the nipple-areolar complex with an
adhesive film dressing in preventing perioperative expression of bacteria from
nipple ducts contaminating the operative field. One swab from the nipple after
skin preparation and none of the swabs taken from the outer surface of the film
dressing postoperatively yielded any bacterial growth. Fourteen breasts (33%) in
11 patients (44%) yielded bacterial growth from swabs under the film
postoperatively. Six of 9 breasts (67%) in 5 patients who had capsulectomies had
bacteria isolated from under the film postoperatively. Ten of 14 (71%) control
breasts (no shields) in 6 of 7 patients (86%) had positive postoperative swabs.
This study confirms the potential risk of bacterial contamination arising from
nipple duct flora during intra-operative breast manipulation, and the
effectiveness of a perioperative adhesive film placed over the nipple-areolar
complex in preventing subclinical bacterial contamination of implanted breast
prostheses.
PMID- 10673920
TI - Psychosocial outcome and patient satisfaction following breast reduction surgery.
AB - There is an increasing awareness that psychosocial outcome and health status are
important outcomes following breast reduction surgery. In this study, patients
awaiting breast reduction surgery completed detailed and comprehensive
psychosocial assessments before and after surgery. Of 33 patients who completed
the preoperative assessment, 20 patients were operated on and 19 were reassessed
4 months post-surgery. Patients expressed high levels of satisfaction with
specific and overall results of surgery. Scores for anxiety, depression, body
image and body satisfaction improved significantly using specific questionnaires.
Patients also reported significant improvements on five out of eight subscales on
the Short Form 36 health status questionnaire. This study provides further
evidence for overall improvement in health status and psychological functioning
in patients undergoing breast reduction surgery and supports the provision of
this service by the NHS.
PMID- 10673921
TI - Preliminary report: the distally pedicled dorsoulnar forearm flap for hand
reconstruction.
AB - In this paper, a new flap for the coverage of soft tissue defects in the hand is
described. To obtain a distally pedicled dorsoulnar flap, the dissection of the
standard dorsoulnar flap is continued distally under the descending branch of the
dorsal branch of the ulnar artery onto the dorsum of the wrist after the dorsal
branch of the ulnar artery is ligated and divided. Our modification of the
standard dorsoulnar flap converts this flap to a distally based flap, which
provides a potentially longer pedicle and increases the arc of rotation of the
flap. Two successful cases are reported.
PMID- 10673922
TI - Closure of elective skin defects in the leg with a fasciocutaneous V-Y island
flap.
AB - Skin defects in the leg can be among the most difficult to cover. Split skin
grafting of such defects can be complicated by delayed healing and poor cosmesis
and this has led to the description of several local flap techniques. Here a
technique of V-Y flap closure is described based laterally on a random fascial
pedicle. Twenty patients aged from 51 to 85 years had flaps for skin closure
after excision of skin tumours, 17 of them in the middle or lower third of the
leg. All but one were performed under local anaesthetic, seven as day cases and
eight with an overnight stay. No patient was excluded because of medical
conditions or skin quality and two patients had significant lymphoedema. A single
V-Y flap was used in each case and was found to have much greater mobility than
previously described similar flaps. Cosmetic results, and in particular contour
preservation, were found to be excellent. There were no complete flap losses but
four patients had delayed healing, two related to partial flap necrosis. Four
patients had wound infections, one requiring readmission for intravenous
antibiotics but no patient had further surgery. The fasciocutaneous V to Y island
flap was found to be a very satisfactory method of wound closure in the leg with
an acceptable complication rate and excellent cosmetic results.
PMID- 10673923
TI - Emergency management of type IIIB open tibial fractures.
AB - We present our therapeutic strategy for the treatment of type IIIB open tibial
fractures. It involves emergency internal stabilisation of the bone by locked
intra-medullary nailing when appropriate and skin cover using either a pedicled
or free muscle flap. Where there is bone loss, a cancellous iliac graft is
performed at the same time. Eighteen cases of type IIIB open tibial fractures
treated between 1986 and 1995 were analysed. There were 17 men and 1 woman; the
average age was 35 years. Each of the 18 patients underwent wound debridement as
a primary emergency procedure with no secondary reoperation. Bone fixation was
performed by locked intra-medullary nailing (AO nail, How Medica) 6-10 h after
trauma. A primary cancellous iliac bone graft was performed in three cases. Cover
was applied immediately after nailing (muscular pedicle flaps in 12 cases,
muscular free flaps in 6 cases). Local flap cover led to two failures: both these
fractures were followed by postoperative complications. The 6 free muscle flaps
were successful. The average time to bone union was 6.5 months (range: 3-18.5
months) according to clinical criteria and 9 months (range: 4-27 months)
according to radiological criteria. Out of the 18 fractures, 13 were primarily
united (72.2% of cases); 3 involved osteitis and 2 nonunion. Sixteen patients
were examined again with a mean follow-up of 4.8 years (range: 1-11 years). Six
moderate malunions occurred; none needed surgical reoperation. Ankle motion was
normal in 7 cases and reduced to below 50% in 9 cases when compared with the
healthy ankle. Thirteen patients resumed their previous professional activities.
This surgical strategy reduces bone union time, the number of operations and the
time spent in hospital; it improves functional results.
PMID- 10673924
TI - Reconstruction of perianal skin defect using a V-Y advancement of bilateral
gluteus maximus musculocutaneous flaps: reconstruction considering anal cleft and
anal function.
AB - In order to preserve the anal function after ano-perianal skin excision for
malignancy, we have reconstructed a deep, symmetrical natal cleft using a V-Y
advancement of bilateral gluteus maximus musculocutaneous flaps thinned medially
and sutured to the ooccyx, anococcygeal ligament and the central tendon of the
perineum. This technique was applied in three cases of Bowen's disease and two
cases of Paget's disease. In all five cases, postoperative anal functions such as
comfortable defecation and sensation, were well preserved, the perianal skin and
underwear stayed clean, and there was no disturbance of walking or exercise.
PMID- 10673925
TI - Recurrence rates of ischial sores in para- and tetraplegics treated with
hamstring flaps: an 8-year study.
AB - We have collected data on the second follow-up of 27 patients who underwent
musculocutaneous flap closure of their ischial pressure sores. Thirty-seven
ulcers were operated on between 1988 and 1993 using the V-Y advancement hamstring
musculocutaneous island flap. At the initial follow-up (mean = 20 months) in
1993, despite 33% of patients having had recurrent ulcers and 14.8% having
undergone re-advancements, only 14% of patients had non-healing ulcers. In 1997,
follow-up period ranged from 18 to 90 months, with a mean of 62 months. Four
patients were lost to follow-up resulting in 23 patients (n = 23) for the current
study. Nine patients were tetraplegic and the remaining 14 were paraplegic. Four
of the 23 patients had died at follow-up therefore making the number of living
patients 19 (n = 19). The total number of ulcers operated on in the current study
was 29 (U = 29). Overall, ulcer and patient recurrence rates were 41.4% and 47.8%
respectively. Despite this, 89.5% of patients had intact flaps at the time of
follow-up. We recommend the use of the hamstring V-Y musculocutaneous flap as a
reliable and safe reconstructive modality in the management of ischial pressure
sores and by identifying the group of patients susceptible to ulcer recurrence we
have proposed a protocol for their long-term follow-up.
PMID- 10673926
TI - Subcutaneous adrenaline infiltration in paediatric burn surgery.
AB - Paediatric burn surgery may be associated with significant blood loss and
postoperative pain. To investigate methods of reducing these symptoms, we studied
a prospective series of 29 children with small to medium sized burns.
Presurgically both the burn wound and split skin graft donor sites were injected
with a 1:500,000 adrenaline solution, to which bupivicaine had been added. No
patient required blood transfusion and no patient developed systemic side effects
from the injected solution. Four patients required parenteral analgesia, two in
the immediate postoperative period and two at first dressing change. In all other
patients pain was controlled with oral analgesia alone. Mean graft take in our
series was 95%, indicating that this technique does not compromise burn depth
assessment, nor impair graft survival.
PMID- 10673927
TI - Colour shift following tattoo removal with Q-switched Nd-YAG laser (1064/532).
AB - Colour shift in tattoo pigment is a recognised complication of laser tattoo
treatment. We report our experience over the past 4 years in treating 275
patients, with a total of 323 professional tattoos. Of these, 184 tattoos
contained a pigment other than black with 33 displaying a colour shift as a
consequence of laser treatment. This adverse effect was recorded with red,
yellow, crimson and brown pigments but most frequently with white/flesh pigments.
We found brown and white/flesh coloured pigments to be significantly more likely
to change colour compared to red and that the chance of certain colours shifting
related to the age of the tattoo. We outline our management of this problem and
discuss the results of continued treatment.
PMID- 10673928
TI - The establishment of a burns unit in a developing country--a collaborative
venture in Malawi.
AB - In September 1993, the recently completed 32-bedded Burns Unit in the Queen
Elizabeth Central Hospital, Blantyre, Malawi, was officially opened. This
represented the culmination of 3 years' planning and construction; this paper
presents our experience in developing this type of project, and an analysis of
the early results of treatment in the unit. The widespread neglect of this common
injury in developing countries is highlighted and the importance of input from
specialists in this field working in collaboration with local medical and nursing
staff is emphasized. The potential for making a significant impact in reducing
the morbidity and mortality in burn injuries is highlighted.
PMID- 10673929
TI - Digital surgery revisited. On the origin of digital transfer in reconstructive
surgery.
AB - A scarred donor site has been of secondary concern in reconstructive surgery,
being the price one had to pay for the repair of a defect. In the 19th century
reconstruction at the sacrifice of a little finger was contemplated and applied
to difficult nasal repairs. The loss of a finger was sometimes preferred thus
avoiding additional scars on the forehead and cheek. This so called 'Russian
method' is of British origin, described in 1875 by James Hardie of Manchester.
PMID- 10673930
TI - Pseudocyst formation after abdominoplasty--extravasations of Morel-Lavallee.
AB - A soft tissue injury can lead to the formation of a pseudocyst in the
subcutaneous adipose tissue, due to a seroma, haematoma or fat necrosis. These
cysts were first described in 1853 by the French physician Morel-Lavallee. He
observed the phenomenon in the lower limb in women after a tangential trauma with
separation of the fatty layers. A similar condition can occur following surgery
of the abdomen, when performing liposuction and subcutaneous dissection with a
large dead space. In this report we present two cases with large pseudocysts in
the abdominal wall, which were seen in long term follow-up after an
abdominoplasty performed elsewhere. The pathogenesis, the treatment and the
literature are discussed.
PMID- 10673931
TI - Microneurovascular transfer of contralateral latissimus dorsi in Poland's
syndrome.
AB - A 2-year-old girl with Poland's syndrome presented with syndactyly of the first,
second and third webs of the left hand and ipsilateral absence of the
sternocostal portion of pectoralis major. Latissimus dorsi on the same side was
also absent. A microvascular free contralateral latissimus dorsi muscle transfer
was undertaken to reconstruct the chest wall and anterior axillary fold. The
transfer was innervated by intercostal nerve transfer and produced a
neuromuscular unit of good aesthetic appearance and function.
PMID- 10673932
TI - Subcutaneous emphysema of a digit through a pre-existing puncture wound.
AB - A case of injection of compressed air into a digit is reported. The air was
injected at 50 PSI through a trivial puncture wound sustained some hours
previously. The case had a benign course, in comparison to high pressure
injection injuries with foreign material.
PMID- 10673933
TI - An unusual case of orbital trauma with a large foreign body in the maxilla.
AB - A case in which a broken handle of a scooter was found lodged in the right
maxillary sinus and infratemporal fossa with an unusual route of entry through
the orbital floor without any injury to the globe is reported.
PMID- 10673934
TI - Experience of methicillin-resistant Staphylococcus aureus in a plastic surgery
unit.
PMID- 10673935
TI - The use of blood as a marker on the lips: an aid to reconstruction--reply.
PMID- 10673936
TI - A simple method of decreasing the morbidity of split-thickness skin graft donor
sites.
PMID- 10673937
TI - Breast reduction--rationed or rational?
PMID- 10673938
TI - Placement of sutures in tendon repair.
PMID- 10673939
TI - An efficient form of note taking.
PMID- 10673940
TI - Trilucent breast implants--a personal review of the current controversies (May
1999)
PMID- 10673941
TI - The cancer patient in the radiology department: do we live up to our
responsibilities?
PMID- 10673942
TI - Features of unusual metastases from prostate cancer.
AB - A retrospective study of CT examinations on 508 patients with prostate carcinoma
was performed in order to document the presence or absence of uncommon nodal and
extranodal metastases according to pre-defined criteria. 45 atypical metastases
were demonstrated in 36 patients. There were 23 atypical nodal metastases
including unusual distribution (19/23), large volume (7/23) and atypical
morphology or contrast enhancement pattern (8/23). 22 atypical extranodal
metastases included orbit/skull base (11), pulmonary (4), liver (3), intracranial
(2), ocular (1) and adrenal (1). Atypical prostate carcinoma metastases are
usually encountered in the presence of known advanced disease but can be the
presenting feature of malignancy or the only sign of distant spread. Knowledge of
atypical manifestations of metastatic disease will reduce diagnostic delay, allow
accurate staging and lead to the effective and timely delivery of appropriate
treatment.
PMID- 10673943
TI - Ultrasound of testicular epidermoid cysts.
AB - The ultrasound findings of focal intratesticular lesions may sometimes be
characteristic of benign pathology, which accounts for approximately 5% of all
testicular tumours. Three cases of epidermoid cysts of the testis are presented
along with a review of the literature. Recognition of the typical ultrasound
appearances of this entity in a clinical situation of painless testicular
swelling in the absence of a history of trauma and signs of inflammation can make
testis-sparing surgery feasible.
PMID- 10673944
TI - First trimester nuchal translucency: effective routine screening for Down's
syndrome.
AB - The objective was to evaluate the effectiveness of 10-14 week nuchal translucency
measurement in routine ultrasound screening for Down's syndrome. 11,398 women
were scanned at 10-14 weeks of pregnancy for nuchal translucency measurements.
The mean maternal age of the screened population was not significantly different
from that of the booking population. A 5% screen positive rate was achieved by
using a nuchal translucency-derived risk of > or = 1:200. Screening using this
nuchal translucency risk would enable the first trimester detection of 16 out of
21 (76%) fetuses with Down's syndrome and 40 out of 49 (81%) aneuploid fetuses.
In conclusion, this study demonstrates that first trimester nuchal translucency
measurement is an effective method of screening for fetal chromosomal
abnormality.
PMID- 10673945
TI - Abdominal ultrasound in acute schistosomiasis mansoni.
AB - Reports on abdominal ultrasound studies in patients with acute schistosomiasis
are still scarce and limited data are available on structural changes of the
liver parenchyma in this stage of the disease. 26 patients with acute
schistosomiasis mansoni were submitted to clinical and ultrasound examination.
For ultrasound comparison, each acute patient was paired by age, gender, weight
and height to a non-infected individual. Ultrasound showed a non-specific
homogeneous size increase of the liver, and spleen in all acute patients, and
easily identified intraabdominal lymph nodes in the periportal region in most
cases. Three out of the five patients with periportal thickening underwent
percutaneous liver biopsy. Periportal thickening disappeared 6 months after
treatment for schistosomiasis. 24 months after successful treatment there was
involution of the liver and spleen; lymph nodes, although reduced in size, were
still easily recognized. Liver biopsy showed dense inflammatory infiltration of
neutrophils, macrophages and eosinophils in the portal tracts associated with
discrete fibrous tissue formation.
PMID- 10673946
TI - Ultrasound guided fine needle aspiration biopsy of splenic lesions.
AB - Fine needle aspiration biopsy (FNAB) of focal splenic lesions has been
infrequently utilized because of the risk of haemorrhage. This study was carried
out to evaluate the safety and efficacy of ultrasound guided FNAB of splenic
lesions. 35 patients with focal splenic lesions underwent FNAB under real-time
ultrasound guidance using a free hand technique. Ultrasound findings were single
or multiple focal hypoechoic lesions (n = 33), focal hyperechoic lesion (n = 1)
and diffuse heterogeneous echotexture (n = 1). Aspirations were performed with 22
G spinal needles using either the subcostal or the intercostal approach. Definite
cytological diagnosis was made in 22 patients (62.8%), including tuberculosis in
10 patients, lymphoma in seven patients, extramedullary haematopoiesis in two
patients and aspergillosis, histoplasmosis and bacterial abscess in one patient
each. FNAB was negative in 12 patients because the aspirates were either scanty
or contained only blood. FNAB was falsely positive in one patient. Only one
patient had significant intraabdominal bleeding, which was managed
conservatively. In conclusion, splenic FNAB performed under ultrasound guidance
is a safe and accurate method in the diagnosis of focal splenic lesions.
PMID- 10673947
TI - Measurement imprecision in vertebral morphometry of spinal radiographs obtained
in the European Prospective Osteoporosis Study: consequences for the
identification of prevalent and incident deformities.
AB - Several algorithms are currently in use for evaluating vertebral deformities from
plain lateral radiographs of the lumbar and thoracic spine. However, the effects
of measurement imprecision as well as uncertainties over image magnification on
the correct identification of prevalent and incident vertebral deformities with
these algorithms has been little studied. In a pilot study for the European
Prospective Osteoporosis Study (EPOS), plain radiographs were submitted to a
single central evaluating centre for measurement of vertebral height from T4 to
L4. The thoracic and lumbar spines were imaged on separate films, and we have
assessed the precision of measurement of vertebral heights and height ratios. The
standard deviation of the differences between films of each of three height
measurements ranged from 1.1 to 1.2 mm. A two-stage strategy for identifying
incident deformities was devised. This required that the vertebra be a prevalent
deformity at the time of the second radiograph and also that at least one of the
vertebral ratios should have changed significantly since the first radiograph.
The second stage removed all but two of the 18 vertebrae flagged positive in the
first stage but not considered to be certain incident fractures by clinical
reading of the radiographs.
PMID- 10673948
TI - Comparison of adult and paediatric spine and whole body software for the Lunar
dual energy X-ray absorptiometer.
AB - Simple phantoms were devised to compare the performance of adult (software 3.64)
and paediatric (software 3.8 g) spine and whole body software developed for the
Lunar dual energy X-ray absorptiometer. Rectangular slabs of aluminium with high
(1.18 g cm-2) and low (0.57 g cm-2) density were used to represent bone mineral.
For spine measurements, the phantoms were scanned in water at depths of 5-20 cm.
For whole body measurements, the phantoms were scanned with known amounts of oil
and water to represent fat and lean tissue. This simulated tissue depths of 5.5
19.7 cm and body composition ranging from 14-29% fat. There were systematic
differences in spine and whole body bone mineral content (BMC), bone area (BA)
and bone mineral density (BMD) measurements and also between adult and paediatric
software versions. The magnitude and direction of these differences were
dependent on BMD of the phantom and tissue depth. Similar systematic differences
were observed in vivo when volunteers were scanned using adult and paediatric
software. Paediatric software enabled measurements to be made at low tissue
depths. The weights of fat, lean and total soft tissue measured by the adult and
paediatric whole body software were similar to the values calculated from the
known composition of the phantom. Precision estimates for all softwares were
excellent. In conclusion, paediatric software should improve bone mineral
measurements of children but the discrepancies between adult and paediatric
softwares may cause problems in longitudinal studies of skeletal growth and when
compiling reference data from infancy through to adulthood.
PMID- 10673949
TI - A phantom-based evaluation of an exposure equalization technique in mammography.
AB - An anatomical filter based exposure equalization technique in mammography is
evaluated quantitatively using a phantom. The evaluation is carried out by a
comparative observer performance study, comparing the equalization technique with
a conventional one based on visualization of low contrast, 6 mm circular details
and high contrast, 0.5 mm and 0.25 mm small size details. These details are
situated at the phantom edge, simulating the breast periphery. Visualization of
these details is studied with respect to the parameters of tube voltage, optical
density, detail location and phantom thickness. Phantom images are interpreted
independently by three observers using a four-point grading scale. Use of the
Wilcoxon signed ranks test for paired data shows statistically highly significant
improvement (p < 0.0001) in the visualization of details for the equalization
technique for all values of the parameters studied. The improvement is
independent of tube voltage but dependent on optical density, detail location and
phantom thickness. Optimal performance is obtained for detail location closer to
the outer border of the simulated breast periphery and/or further away from the
film, as well as for a greater phantom thickness simulating both thick and dense
breast.
PMID- 10673950
TI - Reducing cardiac dose in post-operative irradiation of breast cancer patients:
the relative importance of patient positioning and CT scan planning.
AB - Left-sided post-operative radiotherapy fields for the treatment of breast cancer
inevitably encompass the heart within the treatment volume, resulting in late
mortality which may negate the cause-specific survival advantage of the therapy.
The effect of positioning was studied in 11 patients with left-sided tumours and
five with right-sided tumours receiving routine post-operative radiotherapy to
the breast or chest wall as part of primary therapy for breast cancer. Using the
same arrangement of glancing fields for each patient treatment position, the
optimum patient positioning resulted in a reduction in cardiac dose compared to
our standard patient treatment position. On the left side the reduction in mean
cardiac dose was 60% (p < 0.001) and the reduction in maximum dose was 32% (p <
0.001); on the right it was 17% and 31%, respectively. The volume of cardiac
tissue irradiated was also reduced for all patients. Using this optimum treatment
position, cardiac dose was investigated in a further 10 patients with left-sided
tumours and our standard glancing field set-up was compared with 3-dimensional
planning. A further reduction of 12% in the mean cardiac dose was achieved. 5 of
10 patients had a further small reduction of 4.6% in the maximum dose and one
patient had a further reduction in maximum dose of 58%. In conclusion,
sophisticated radiotherapy planning can reduce cardiac doses, but optimum patient
positioning is of greater importance. The general application of such relatively
simple measures could have a significant positive effect on overall survival from
breast cancer.
PMID- 10673951
TI - Small bowel MRI using water as a contrast medium.
AB - Magnetic resonance imaging (MRI) of the small bowel has been limited by lack of
an adequate luminal contrast medium and problems with image artefacts. In this
study we investigate the feasibility of imaging the luminal small bowel using
rapid heavily T2w techniques, similar to those used for MR
cholangiopancreatography, combined with oral water loading. Eight volunteers were
examined after drinking 1-21 of water using serial, multisection, half-Fourier
single shot rapid acquisition with relaxation enhancement (RARE) acquisitions.
The examinations were continued until the terminal ileum was reached or the water
reabsorbed. The results were subjectively assessed for visibility of the small
bowel. In all subjects the duodenum, jejunum and ileum were well demonstrated
with valvulae conniventes clearly visible. The water column reached the terminal
ileum and the caecum in six of the eight subjects but in the remaining two water
remained in the small bowel and was ultimately reabsorbed. These preliminary
results suggest that with further refinement such an approach may be practical
for clinical magnetic resonance imaging of the small bowel.
PMID- 10673952
TI - High speed injection of radiographic contrast media induces severe particulate
contamination.
AB - In a study of exogenous particulate contamination during angiography, the effect
of injection speed of four kinds of radiographic contrast media (RCM) was
investigated. The particle count (> or = 10 microns) in all RCM increased in a
speed-dependent manner and the increase was especially dramatic at 3 ml s-1. The
extent of increase in particulate matter was higher for ioxaglate than for the
other three RCM. As particulate matter is unwanted and unnecessary, to prevent
the harmful effects in patients much attention should be paid to various factors
generating particulate matters, such as characteristics of RCM and plastic
syringe.
PMID- 10673953
TI - The performance of a fluoroscopic electronic portal imaging device modified for
portability.
AB - Advances in external beam therapy technology have made routine, efficient
conformal therapy a reality. With it comes the increasing need for online
treatment verification, which is only achievable at present through the use of
electronic portal imaging devices (EPIDs). For a large radiotherapy centre, the
provision of one EPID per treatment machine proves extremely expensive. This
paper details modifications to the design of a commercial fluoroscopic EPID (the
SRI-100) to produce a portable system, capable of providing quick, high quality
imaging on more than one treatment machine. We describe the necessary hardware
and software changes made to the system, as well as the variety of mechanical and
quality control checks performed for testing the stability and quality of the
imaging. The modified system has been found to be both electronically and
mechanically robust, with associated image quality, scaling, distortion and
movement similar to other EPIDs in the department. Although the modification was
designed specifically to allow for the acquisition of images from multiple
treatment machines, it may also enable the operation of the EPID for other uses
such as total body irradiation (TBI) treatment verification and a further range
of quality control procedures on the linear accelerator itself.
PMID- 10673954
TI - Magnetic resonance imaging of actinomycosis presenting as pelvic malignancy.
AB - Pelvic actinomycosis is associated with long-standing use of an intrauterine
contraceptive device and may present with clinical signs and symptoms of pelvic
malignancy. Diagnostic imaging can confirm the presence of a pelvic mass and
tissue infiltration but findings are often non-specific. We present a case of
pelvic actinomycosis with tubo-ovarian abscess in which magnetic resonance
imaging demonstrated lower signal intensity tissue on T2 weighted sequences than
would be typical for pelvic malignancy or infection and was useful in confirming
regression of pelvic disease in response to antibiotic therapy.
PMID- 10673955
TI - Plasma cell neoplasms in the young.
AB - Multiple myeloma, a disease of the elderly, is extremely rare in those below 30
years of age. Two patients with multiple myeloma diagnosed at 20 years and 18
years are described. Both presented with extradural cord compression, lytic bone
lesions and bone marrow plasmacytosis. One patient received combination
chemotherapy and radiotherapy and survived for 14 years. A literature review is
presented.
PMID- 10673956
TI - A case of rectoprostatic fistula due to prostatic abscess visualized by barium
enema.
AB - We report a rare case of rectoprostatic fistula due to spontaneous rupture of a
prostatic abscess in a patient with diabetes mellitus. Barium enema clearly
showed rectoprostatic fistula. Barium enema and colonoscopy were very useful in
demonstrating the rectoprostatic fistula.
PMID- 10673957
TI - Hepatic artery aneurysm.
AB - Hepatic artery aneurysms (HAAs) are rare. A review of the English language
literature from 1985 to 1995 for reports of visceral artery aneurysms showed HAA
to be the most frequently reported visceral aneurysm during that decade. This
increase in incidence relates to the increasing use of percutaneous diagnostic
and therapeutic procedures. A second factor is the increased use of diagnostic CT
scanning after blunt liver trauma. The purpose of this pictorial review is to
illustrate the imaging presentation and radiological management of HAAs.
PMID- 10673958
TI - Too much fat in the wrong places.
PMID- 10673959
TI - Contrast-enhanced CT in acute pancreatitis.
PMID- 10673960
TI - Psychosocial oncology: the state of the art at the end of the millennium.
PMID- 10673961
TI - Psycho-oncology: where have we been? Where are we going?
AB - This article reviews the development of the subspeciality of psycho-oncology and
its contributions to patient care, encouraging more attention to and research
into the care of the total patient: the physical, psychological, social and
spiritual aspects of care. The result is enhanced quality of life as the patient
is studied in the domains of living that are important, extending across the
continuum of care from diagnosis to palliative care. In addition, cancer
prevention and early detection depends largely on changing attitudes and
behaviours that put people at greater risk. This is an important area of research
for psycho-oncologists. In the past two decades, research has contributed to our
understanding of the psychological responses that accompany a cancer diagnosis.
Oncologists better recognise psychological distress and psychiatric disorders
such as anxiety, depression and delirium (in hospitalised patients) as frequent
comorbid disorders. The development of valid assessment tools for the patients'
self-report has been important. Increasingly, outcome measures in controlled
trials of new therapies include quality of life, and no longer look at survival
alone. The future will continue to bring new challenges to psycho-oncology as
patients face new challenges in treatment. A major aim of the next century will
be to bring this integrated approach to all patients in an affordable manner.
PMID- 10673962
TI - Psychosocial interventions for patients with cancer: what works and what doesn't.
AB - With the successes that have been achieved in cancer care leading to patients
surviving longer, the need for a variety of psychosocial intervention models is
posing a new challenge to the field. This article reviews the general categories
of interventions used most commonly: (1) education; (2) coping; (3) emotional
support; and (4) psychotherapy. It provides a theoretical model for designing
psychosocial interventions, and provides guidelines for assessing what works and
what doesn't.
PMID- 10673963
TI - What has been learned from measuring health-related quality of life in clinical
oncology.
AB - The measurement of health-related quality of life (HRQL) in oncology clinical
trials has come of age. Most cooperative clinical trials groups as well as
individual institutions have either been measuring, or are starting to measure,
HRQL. Over the past decade, much has been learned about how to incorporate HRQL
components into multicentre, randomised controlled (phase III) trials and how to
collect the data with reasonably low levels of missing information. A selective
review, focused primarily on phase III studies, shows that HRQL data are useful
for deciding which treatment is preferable when survival rates are similar and
for determining whether changes in HRQL, as compared with baseline levels, are
related to a treatment or intervention. HRQL information is improving our
knowledge of the effects of diseases and their treatments on the patient's
ability to function and sense of well-being, and HRQL status is proving to be a
more accurate predictor of survival than is performance status. Much more remains
to be done, but it is apparent that the inclusion of HRQL in clinical trials has
been informative and useful. The increasing frequency of HRQL assessment in
clinical trials is evidence of the emergence of a patient-centred philosophy in
clinical medicine which, in time, will modify the disease-oriented paradigm under
which medical professionals have functioned for the past century.
PMID- 10673964
TI - Quality of life instruments in oncology.
AB - The objective of this article is to aid clinicians in understanding the current
state of the development and application of quality of life (QOL) instruments as
outcome measures in cancer clinical research and practice. As a result of the
achievements of the past two decades, the concept of QOL has been defined and
many reliable and valid measurement tools have been developed. The two main
approaches to QOL assessment, psychometric-based and utility-based, are discussed
together with a brief description of the strategies for meaningful interpretation
of QOL profiles. QOL measures in oncology have the potential to be used to study
populations in randomised clinical trials, to aid patient-clinician interactions
in routine practice and to support policy decision making and economic evaluation
of healthcare provision.
PMID- 10673965
TI - Improving the quality and quantity of life among patients with cancer: a review
of the effectiveness of group psychotherapy.
AB - Cancer patients suffer from a number of psychosocial problems related to the
progression of their disease as well as standard medical interventions.
Fortunately, there is empirical evidence suggesting that group psychotherapy is
effective at ameliorating psychological distress and in some cases improving
survival. For this literature review we examined the psychological morbidity,
particularly anxiety and depression, among cancer patients. Further, we conducted
a critical examination of the current evidence regarding the effectiveness of
group psychotherapy for improving the quality as well as the quantity of life in
cancer patients. Finally, we explored the specific components of effective group
psychotherapy, which has been associated with enhanced survival. We conclude that
there is compelling evidence indicating that group psychotherapy improves the
quality of life of cancer patients. Furthermore, there is a growing body of
evidence suggesting that group psychotherapy improves survival of cancer
patients.
PMID- 10673966
TI - Cancer information: a cost-effective intervention.
AB - There is a considerable knowledge base about the information needs of patients
with cancer (and their relatives and friends). Those needs will vary according to
the disease, the stage of disease, the patient and his or her age, social class
and culture. Lack of information may lead to increased anxiety and distress, may
impact negatively on the patient's satisfaction and may influence a patient's
treatment choices. Other articles in this special edition deal with psychosocial
interventions and complementary therapies for cancer patients and explore their
efficacy. The reality is that these are unlikely to be made available to all
cancer patients for reasons of cost and practicability. Information, however, is
a relatively cheap intervention that could--and should--be part of standard care.
This article explores some of the research about the provision of information for
cancer patients.
PMID- 10673967
TI - Effective communication skills are the key to good cancer care.
AB - Communication within oncology is a core clinical skill but one in which few
oncologists or specialist cancer nurses have received much formal training.
Inadequate communication may cause much distress for patients and their families,
who often want considerably more information than is usually provided. Many
patients leave consultations unsure about the diagnosis and prognosis, confused
about the meaning of--and need for--further diagnostic tests, unclear about the
management plan and uncertain about the true therapeutic intent of treatment.
Additionally, communication difficulties may impede the recruitment of patients
to clinical trials, delaying the introduction of efficacious new treatments into
clinics. Lack of effective communication between specialists and departments can
also cause confusion and a loss of confidence amongst the team. Oncologists
themselves acknowledge that insufficient training in communication and management
skills is a major factor contributing to their own stress, lack of job
satisfaction and emotional burnout. Consequently, over the past few years there
have been several initiatives aimed at improving basic communication skills
training for healthcare professionals in the cancer field. In this paper, some of
the issues that influence communication within an oncology setting, and
ultimately affect patient care, are discussed.
PMID- 10673968
TI - The impact of patient treatment preferences on the interpretation of randomised
controlled trials.
AB - Reliable information about aggregate main treatment effects in cancer research
comes from randomised controlled trials (RCTs). The possibility of important
interactions, such as between treatment preferences and their effects, is
necessarily subordinated in the quest for evidence about main treatment effects.
If patient preferences can influence the effectiveness of treatments, for which
there is some indirect evidence, then those estimates of the treatment's main
organic effects from unblind RCTs might be wrong. RCTs clearly disallow patient
choice and it is, therefore, important to know the extent of any preference
effects in order to interpret the RCT evidence. It may be important to know
whether they exist, and where and by how much they affect outcome. It is argued
that measuring these effects reliably is methodologically difficult, and will
require massive trials each directed at measuring one particular preference
effect. Such effects have a slightly fanciful image, particularly in cancer
treatment, and may be transient. Given the current uncertainties about their true
nature and plausible biological mechanisms, the accumulated evidence is unlikely
to provide sufficient justification for investing in such trials, given other
current priorities.
PMID- 10673969
TI - Psychoneuroimmunology and cancer: fact or fiction?
AB - There is substantial evidence from both healthy populations as well as
individuals with cancer linking psychological stress with immune downregulation.
This discussion highlights natural killer (NK) cells, because of the role that
they may play in malignant disease. In addition, distress or depression is also
associated with two important processes for carcinogenesis: poorer repair of
damaged DNA, and alterations in apoptosis. Conversely, the possibility that
psychological interventions may enhance immune function and survival among cancer
patients clearly merits further exploration, as does the evidence suggesting that
social support may be a key psychological mediator. These studies and others
suggest that psychological or behavioural factors may influence the incidence or
progression of cancer through psychosocial influences on immune function and
other physiological pathways.
PMID- 10673970
TI - How useful are unconventional cancer treatments?
AB - Unconventional cancer treatments are used frequently. Therefore, oncologists need
to know about them. This article gives an overview of current knowledge on the
most prevalent complementary or alternative cancer therapies. A distinction is
made between alleged cures, preventive and adjunctive measures. Shark cartilage,
mistletoe, thymus therapy, essiac, hydrazine sulphate, 714-X, dietary regimens,
green tea and Panax ginseng are all covered specifically. None of these
treatments offer reasonable hope for a cure. Some strategies are promising in
terms of cancer prevention. The true potential of unconventional therapies might
lie in adjunctive and palliative care. It is concluded that good evidence in this
area is scarce. Vis-a-vis the high prevalence of unconventional cancer
treatments, rigorous investigations are mandatory, not least for increasing the
safety of future patients.
PMID- 10673971
TI - Testing complementary and alternative therapies within a research protocol.
AB - In patients with cancer, the demand for complementary and alternative medicine
(CAM) is considerable. Unfortunately, however, for many of these interventions
there is a lack of evidence for efficacy, effectiveness and safety in patients
with cancer. This review focuses on the prospective, randomised, controlled trial
(RCT) as a tool for evaluating CAM. Although a number of difficulties and
limitations are acknowledged, the RCT will continue to be the gold standard for
evaluating the efficacy, effectiveness and safety of CAM. Developments in
clinical trial methodology and in psychosocial oncology have made it more
appropriate and feasible to evaluate CAM using RCT methodology. Two different
kinds of RCTs are now accepted as valid, namely explanatory and pragmatic trials.
The latter does not necessarily require that the patient or the therapist is
'blind' to the treatment being given. Furthermore, pragmatic trials can be
designed to take patient preferences into account. A number of practical issues
are discussed, including the choice of comparator or control interventions, ways
of assessing the effects of individual differences, minimising therapist
variability, the problem of finding acceptable inclusion-exclusion criteria and
the assessment of treatment outcome. A number of randomised, controlled trials
have demonstrated the efficacy, effectiveness and safety of various complementary
and alternative interventions (the Cochrane Data Base has now established a CAM
field). The publication of positive results from randomised trials of
complementary interventions that have not yet been studied using this methodology
would do a great deal to alleviate the scepticism of conventional practitioners
towards these types of CAM and would facilitate further the integration of
complementary and conventional interventions.
PMID- 10673972
TI - Improving communication with cancer patients.
AB - If doctors and nurses involved in cancer care are to help patients and their
families achieve an optimal level of quality of life and psychological adjustment
they must be able to carry out key communication tasks successfully. Yet,
objective scrutiny of their consultations confirms that deficiencies in their
ability to conduct these tasks remain. The reasons for this are discussed before
important innovations in training and their impact are described.
PMID- 10673973
TI - EORTC scientific strategy meeting 25-26 March 1999.
PMID- 10673974
TI - Efficacy and safety of docetaxel (Taxotere) in heavily pretreated advanced breast
cancer patients: the French compassionate use programme experience.
AB - The aim of this investigation was to assess retrospectively docetaxel safety and
efficacy in advanced breast cancer patients in a French compassionate use
programme. Patients had received > 1 prior chemotherapy regimen for advanced
disease, were either anthracycline-resistant (that is progressed within 6 months
after anthracycline-based chemotherapy) or had received the maximum cumulative
dose. The recommended docetaxel dose was 100 mg/m2/cycle (75 mg/m2 in case of
liver function impairment: transaminases > 1.5 x upper limit of normal (ULN),
alkaline phosphatases > 3 x ULN). Between August 1993 and December 1995, 889
patients were treated in 67 French centres, of whom 870 were evaluable for safety
and 825 were evaluable for patient and treatment characteristics and efficacy.
20.5% (of the 825 patients evaluable for baseline characteristics) had poor
performance status (PS > or = 2), 49.3% liver metastasis and 9.6% biological
liver dysfunction. 98.4% had been previously treated by anthracyclines, 50.8% had
resistant disease and 37.1% had received > 2 prior palliative chemotherapy lines.
The most frequent severe toxicity, febrile neutropenia (reported in 223/870
(25.6%) patients evaluable for safety), caused 10 deaths, 6 of these being
patients with severe liver impairment before inclusion. Fluid retention syndrome
and other common non-haematological toxicities were well tolerated. 3.1% (28/889)
of all patients and 11.4% of those with liver dysfunction, died from treatment
related causes. The overall response rate in 825 assessable patients was 22.9%
(95% confidence interval (CI): 20.2-26.2%). Median time to treatment failure was
4 months (95% CI: 3.6-4.3) and median survival was 9.8 months (95% CI: 8.8-10.7).
This report on the largest series of unselected advanced breast cancer patients
treated with docetaxel, supports previous phase II studies, confirming
docetaxel's utility in patients relapsing after failing anthracycline-containing
palliative chemotherapy.
PMID- 10673975
TI - Centre effect on treatment outcome for patients with untreated acute myelogenous
leukaemia? An analysis of the AML 8A Study of the Leukemia Cooperative Group of
the EORTC and GIMEMA. European Organization for Research and Treatment of Cancer
(EORTC) Leukemia Cooperative Group and the Gruppo Italiano Malattie Ematologiche
Maligne dell'Adulto (GIMEMA).
AB - In the AML 8A study patients were treated with remission-induction therapy
followed by one consolidation course. Patients in complete remission (CR) were
randomised between autologous bone marrow transplantation (ABMT) and a second
intensive consolidation course, except for those with a histocompatible sibling
donor, who received allogeneic bone marrow transplantation (alloBMT). This
analysis was performed to determine whether centres which only performed
induction and consolidation therapy, achieved similar results as centres who also
performed transplantation. 542/676 (80%) from transplantation centres and 150/194
(77%) from referring centres achieved CR, with an early death rate of 5% and 11%,
respectively (P = 0.01). 66% of patients with a donor from transplantation
centres received alloBMT in first CR compared with 57% from referring centres (P
= 0.2). Transplantation centres randomised 64% of patients without a donor,
referring centres 47% (P = 0.04). The full protocol treatment was completed by
275/542 (51%) and 61/150 (41%) patients, respectively (P = 0.04). The overall
survival rate at 6 years from diagnosis was 34% and 36%, respectively (P = 0.9).
In conclusion, the type of centre did not appear to have an influence on overall
survival. The feasibility of the study was acceptable for both types of centres.
The referring centres applied more selection for transplantation. Despite a more
intensive second-line treatment at transplantation centres, the overall outcome
remained similar to that of referring centres.
PMID- 10673976
TI - The effects of the participation of patients with cancer in teaching
communication skills to medical undergraduates: a randomised study with follow-up
after 2 years.
AB - The importance of good doctor-patient communication is widely recognised. The
aims of this study were to evaluate the immediate effects of the participation of
patients with cancer on the attitudes and skills of undergraduate medical
students receiving an interview skills training programme, and to assess the
effects of the participation of patients with cancer on the attitudes and
interview performance of students 2 years later. It was hypothesised that the
participation of cancer patients would have specific beneficial effects on
attitudes and interview performance. Before participating in a 6-session
interview methods course in third year, students were randomised to be taught
with patients who had cancer (experimental group) or with patients with other
diagnoses (control group). Before and after participating in the course, 233
students (94% response rate) completed an Attitudes Questionnaire. When they
reached their fifth year, 54 students again completed the Attitudes Questionnaire
and, in addition, made a video recording of an interview with a patient who had
gynaecological cancer. These recordings were rated independently by two
researchers using the Interview Rating Instrument. Immediately after the course,
a number of differences were found between the two groups. For example, students
in the experimental group were more likely to consider the ability to listen an
extremely important characteristic of hospital doctors and to consider more
strongly that trust is an essential part of the doctor-patient relationship. 2
years after the course, the ability of hospital doctors to communicate with
patients, and the need for clinical decisions to reflect patients' wishes, were
considered to be more important by students in the experimental group, although
even 96% of controls felt both these issues were very or extremely important. As
hypothesised, the experimental group had better ratings in terms of responding
empathically, showing regard and concern for the patient, and assessing the
impact of the symptoms on the patient's life. The participation of patients with
cancer has beneficial and enduring effects on the attitudes and interview
performance of medical undergraduates. Medical schools should consider how best
patients with cancer can make an important contribution to communication skills
training.
PMID- 10673977
TI - Ifosfamide, vinorelbine and gemcitabine in advanced non-small cell lung cancer. A
phase I study.
AB - The objective of this phase I study was to identify the maximum tolerated dose
(MTD) and toxicity of a three drug, platinum-free regimen, including gemcitabine,
ifosfamide and vinorelbine, in the treatment of patients with advanced non-small
cell lung cancer (NSCLC). 33 chemotherapy-naive patients with histologically
confirmed, unresectable NSCLC, received fixed doses of ifosfamide (1500 mg/m2
days 1-3 with mesna) and vinorelbine (25 mg/m2 days 3 and 8). The gemcitabine
dose was escalated from 500 to 1200 mg/m2 on days 3 and 8 every third week. The
escalation was stopped at dose level 4 (gemcitabine 1200 mg/m2) since all 3
patients of this cohort showed dose-limiting thrombocytopenia and/or neutropenia
at treatment cycle 1. The dose recommended for phase II trials is: gemcitabine
1000 mg/m2 and vinorelbine 25 mg/m2 given on days 3 and 8 plus ifosfamide 1500
mg/m2 on days 1-3. An encouraging response rate of 50% (95% confidence interval
(CI): 32-68%) was observed in 32 patients evaluated. Our results show that
ifosfamide, vinorelbine and gemcitabine can be safely administered as outpatient
chemotherapy for NSCLC. Myelosuppression is the dose-limiting toxicity (DLT) of
this regimen with no major subjective side-effects observed.
PMID- 10673979
TI - Paediatric Hodgkin's disease.
PMID- 10673978
TI - Fas expression in non-small cell lung cancer: its prognostic effect in completely
resected stage III patients.
AB - The aim of this study was to examine Fas expression in non-small cell lung cancer
(NSCLC) and examine its correlation with clinicopathological features and
prognosis. Fas expression was determined by an immunohistochemical analysis using
the labelled streptavidin-biotin method from 220 paraffin specimens of completely
resected primary stage I-III NSCLC. 80 (36%) of 220 cases were positive for Fas
immunostaining. These 80 cases included 44 adenocarcinomas (33%) and 30 squamous
cell carcinomas (40%). 33 stage I (33%) 13 (43%) stage II and 34 (37%) stage III
tumours were Fas positive. No statistically significant differences were observed
regarding the Fas status with respect to age, sex, histological type, or stage of
disease. There was no significant difference in survival between early stage
(stages I-II) disease patients with positive Fas expression and those with a
negative expression (P = 0.719). However, for patients with completely resected
stage III tumours, the patients with positive Fas staining were found to survive
for a longer period than those with negative staining (P = 0.026).
PMID- 10673980
TI - Cancer mortality in Europe, 1990-1994, and an overview of trends from 1955 to
1994.
AB - Mortality data, abstracted from the WHO database, are presented in tabular form
for 26 cancer sites or groups of sites, plus total cancer mortality, in 35
European countries during the period 1990-1994. Trends in mortality are also
given in graphical form for 24 major countries over the period 1955-1994. In most
western European countries total cancer mortality was--for the first time-
moderately downwards in the early 1990s. Such favourable trends included some
decline in lung cancer mortality for males, the persistent decline in stomach
cancer for both sexes, and of cervical cancer for women, as well as some decline
in breast and colorectal cancers, plus other neoplasms (testis, lymphoid
neoplasms), whose treatment has further improved over the last few years.
However, cancer mortality was still upwards in a few southern and eastern
European countries, including Hungary and Poland, where total cancer mortality
rates in middle-aged males are now the highest ever registered in Europe. The
favourable trends in western Europe over the recent years are similar to those
observed in the U.S.A.
PMID- 10673981
TI - Induction of apoptosis by apigenin and related flavonoids through cytochrome c
release and activation of caspase-9 and caspase-3 in leukaemia HL-60 cells.
AB - The aim of this study was to investigate the mechanism of flavonoid-induced
apoptosis in HL-60 leukaemic cells. Thus, the effect of structurally related
flavonoids on cell viability, DNA fragmentation and caspase activity was
assessed. Loss of membrane potential and reactive oxygen species generation were
also monitored by flow cytometry. The structurally related flavonoids, such as
apigenin, quercetin, myricetin, and kaempferol were able to induce apoptosis in
human leukaemia HL-60 cells. Treatment with flavonoids (60 microM) caused a rapid
induction of caspase-3 activity and stimulated proteolytic cleavage of poly-(ADP
ribose) polymerase (PARP). Furthermore, these flavonoids induced loss of
mitochondrial transmembrane potential, elevation of reactive oxygen species (ROS)
production, release of mitochondrial cytochrome c into the cytosol, and
subsequent induction of procaspase-9 processing. The potency of these flavonoids
on these features of apoptosis were in the order of: apigenin > quercetin >
myricetin > kaempferol in HL-60 cells treated with 60 microM flavonoids. These
results suggest that flavonoid-induced apoptosis is stimulated by the release of
cytochrome c to the cytosol, by procaspase-9 processing, and through a caspase-3
dependent mechanism. The induction of apoptosis by flavonoids may be attributed
to their cancer chemopreventive activity. Furthermore, the potency of flavonoids
for inducing apoptosis may be dependent on the numbers of hydroxyl groups in the
2-phenyl group and on the absence of the 3-hydroxyl group. This provides new
information on the structure-activity relationship of flavonoids.
PMID- 10673982
TI - Low-doses of ionising radiation induce melanoma metastases and trigger the immune
system--adrenal axis feedback loop.
AB - Low-doses of ionising radiation are frequently implicated in triggering and/or
accelerating the growth of skin and other malignancies. It seemed probable that
the radiation at similar dose levels might initiate metastasis from already
existing tumours. Highly pigmented human melanoma xenograft that had lost its
ability for a spontaneous metastasising and grown subcutaneously in athymic mice
was exposed to very low and well-defined doses of ionising radiation to determine
whether low linear energy transfer radiation can restore metastatic potential of
the tumour. To ensure that all effects derived from radiation-activated
neoplastic cells only, I was delivered selectively to the cutaneous melanoma
instead of using the external beam. The direct response of these tumours to
radiation was monitored by determining the growth rate of the lesions.
Histopathological methods were employed to detect metastases. The lowest
radiation dose of approximately 6 cGy deposited in the tumours initiated
metastatic spread in all animals. Gradual increase of the radiation doses
diminished both the frequency of the appearance of metastases and their distance
from the primary lesions. There were no metastases from non-irradiated melanomas.
The highest dose used (60 cGy) did not affect significantly the growth of
cutaneous (primary) tumours, but lower doses that enhanced inflammatory
infiltration of the lesions reduced tumour growth. Such radiation-stimulated
immune responses were accompanied by increased pigmentation in cutaneous lesions
and activation of the adrenal cortex indicating that the immune system-adrenal
axis feedback loop had been triggered. The results demonstrate that very low
doses of ionising radiation induce melanoma metastases. The phenomenon is
accompanied by the stimulation of the immune system-adrenal axis feedback loop
that regulates eicosanoid synthesis, thereby suggesting an involvement of these
molecules in the process. Radiation doses approaching the therapeutic level do
not initiate melanoma dissemination.
PMID- 10673983
TI - Effect of gamma-linolenic acid on cellular uptake of structurally related
anthracyclines in human drug sensitive and multidrug resistant bladder and breast
cancer cell lines.
AB - This study investigated the effect on drug uptake in multidrug resistant cells by
the incorporation of the essential fatty acid gamma-linolenic acid (GLA). The
cell lines used were the MCF-7/R resistant human breast cancer and MGH-U1/R
bladder cancer. Uptake of drug (doxorubicin, epirubicin, mitoxantrone and
idarubicin) after the incorporation of GLA was investigated quantitatively by
flow cytometry and qualitatively by confocal microscopy. There was no observable
overall increase in drug uptake due to GLA incorporation into the cells as shown
by flow cytometry. However, an increase in uptake of the chemotherapeutic agent
idarubicin was observed in GLA-treated resistant cells compared with untreated
cells using the confocal microscope. This overall increase in cellular drug
uptake was not accompanied by a change in cellular drug distribution. Only one
drug, mitoxantrone, displayed a change in intracellular drug distribution due to
GLA incorporation into MCF-7/R cells. This suggests that essential fatty acid
incorporation into the cellular membranes of some resistant cells may cause a
shift in the intracellular distribution of certain chemotherapeutic drugs.
PMID- 10673984
TI - Inhibition of P-glycoprotein activity and reversal of multidrug resistance in
vitro by rosemary extract.
AB - The transmembrane transport pump P-glycoprotein (Pgp) causes the efflux of
chemotherapeutic agents from cells and is believed to be an important mechanism
in multidrug resistance (MDR) in mammary tumours. In the present study we
demonstrate that an extract of the common dietary herb rosemary (Rosemarinus
officinalis Labiatae), increases the intracellular accumulation of commonly used
chemotherapeutic agents, including doxorubicin (DOX) and vinblastine (VIN), in
drug-resistant MCF-7 human breast cancer cells which express Pgp. Rosemary
extract (RE) inhibits the efflux of DOX and VIN, which are known to be substrates
of Pgp, but does not affect accumulation or efflux of DOX in wild type MCF-7
cells, which lack Pgp. Treatment of drug-resistant cells with RE increases their
sensitivity to DOX, which is consistent with an increased intracellular
accumulation of the drug. RE blocks the binding of the VIN analogue azidopine to
Pgp. Thus, it appears that RE directly inhibits Pgp activity by inhibiting the
binding of drugs to Pgp.
PMID- 10673985
TI - Proto-oncogenes and p53 protein expression in normal cervical stratified squamous
epithelium and cervical intra-epithelial neoplasia.
AB - The aim of this study was to study the protein expression of six proto-oncogenes
(epidermal growth factor receptor (EGFR), c-fms, c-myc, c-kit, c-erbB-2 and pan
ras) and one tumour suppressor gene (TP53), by immunohistochemical staining of
normal cervical stratified squamous epithelium and cervical intra-epithelial
neoplasia (CIN). Paraffin sections of 45 normal cervical specimens, 38 CIN grade
one (CIN1), 37 CIN2 and 43 CIN3 were studied. An immunohistochemical (IHC) score
was derived from the intensity of staining and the percentages of cells stained.
In normal cervical specimens, a higher IHC score was found with EGFR and c-fms in
superficial (S), intermediate (I) and parabasal (PB) cells compared with basal
cells. In contrast, a higher IHC score was found with c-erbB-2 in basal cells in
normal cervical specimens. Dysplastic cells in CIN had a higher IHC score with c
myc and c-erbB-2 than normal S/I and PB cells. Dysplastic cells had a higher
score with EGFR than normal basal cells. However, a higher IHC score with EGFR
and c-fms was found in normal S/I cells than dysplastic cells. These findings
suggested that EGFR and c-fms were activated in more differentiated normal cells
but were less active in less differentiated normal basal cells. However, EGFR was
reactivated in dysplastic cells. Meanwhile, c-erbB-2 was activated in less
differentiated normal basal cells and dysplastic cells, and was less active in
differentiated normal cells. c-myc was activated in dysplastic cells. c-fms was
more active in more differentiated normal cells and was not activated in less
differentiated or dysplastic cells. c-kit, pan-ras and TP53 were not activated in
normal nor dysplastic cervical cells. These results suggest EGFR, c-erbB-2 and c
myc may be important proto-oncogenes in CIN and that antibodies or anti-genes
targeted against them may alter the progress of CIN to invasive cancer.
PMID- 10673986
TI - Comments on: Thoracic radiation therapy before autologous bone marrow
transplantation in relapsed or refractory Hodgkin's disease, Tsang, et al. Eur J
Cancer 1999, 35, 73-78.
PMID- 10673987
TI - Recurrence in the conserved breast: why all this fuss about risk factors?
PMID- 10673988
TI - Cancer chemoprevention: progress and promise.
AB - Cancer chemoprevention is the use of agents to inhibit, delay or reverse
carcinogenesis. The focus of chemoprevention research in the next millennium will
include defining the genotypic and phenotypic (functional and histological)
changes during carcinogenesis, the cancer risk conferred by these changes, their
modulation in preclinical experimentation and randomised clinical trials by
chemopreventive drugs, dietary agents and regimens and treatments resulting from
early detection. The key elements of this research effort will be basic and
translational risk evaluation programmes; chemopreventive and dietary agent drug
discovery and development; development of transgenic animal models; required
safety and pharmacology studies; well-designed phase I, II and III
chemoprevention studies; and much expanded early detection programmes. The large
number of chemoprevention research programmes now ongoing ensures that the
promise of chemoprevention will continue to be realised in the next decade.
PMID- 10673989
TI - Is postoperative irradiation after radical prostatectomy necessary?
PMID- 10673990
TI - A comprehensive geriatric assessment (CGA) is necessary for the study and the
management of cancer in the elderly.
PMID- 10673991
TI - Measurement of clinical and subclinical tumour response using [18F]
fluorodeoxyglucose and positron emission tomography: review and 1999 EORTC
recommendations. European Organization for Research and Treatment of Cancer
(EORTC) PET Study Group.
AB - [18F]-fluorodeoxyglucose ([18F]-FDG) uptake is enhanced in most malignant tumours
which in turn can be measured using positron emission tomography (PET). A number
of small clinical trials have indicated that quantification of the change in
tumour [18F]-FDG uptake may provide an early, sensitive, pharmacodynamic marker
of the tumoricidal effect of anticancer drugs. This may allow for the
introduction of subclinical response for anticancer drug evaluation in early
clinical trials and improvements in patient management. For comparison of results
from smaller clinical trials and larger-scale multicentre trials a consensus is
desirable for: (i) common measurement criteria; and (ii) reporting of alterations
in [18F]-FDG uptake with treatment. This paper summarises the current status of
the technique and recommendations on the measurement of [18F]-FDG uptake for
tumour response monitoring from a consensus meeting of the European Organization
for Research and Treatment of Cancer (EORTC) PET study group held in Brussels in
February 1998 and confirmed at a subsequent meeting in March 1999.
PMID- 10673992
TI - Psychological factors can predict the response to primary chemotherapy in
patients with locally advanced breast cancer.
AB - This study evaluated the possible value of psychological variables in predicting
clinical and pathological response to primary chemotherapy. 96 women with newly
diagnosed large, or locally advanced, breast cancer (T2 > 4 cm, T3, T4, N2 and
M0) participated in a prospective, randomised trial to evaluate the effects of
relaxation training with guided imagery and L-arginine on response to primary
chemotherapy. Before the first of six cycles of primary chemotherapy, women were
assessed using the Hospital Anxiety and Depression Scale (HADS) and the Eysenck
Personality Questionnaire (EPQ). The primary outcomes were clinical response
(evaluated using standard International Union Against Cancer (UICC) criteria) and
pathological response (graded by means of a previously published 5-point scale)
following primary chemotherapy. Stepwise linear regressions were used to estimate
the predictive value of age, menopausal status, clinical nodal status, tumour
size at diagnosis, oestrogen receptor status, dietary supplementation (L-arginine
versus placebo), personality (EPQ-L scores), mood (HADS scores) and a
psychological intervention. HADS depression score was a significant independent
predictor of pathological response to chemotherapy. HADS anxiety score was a
significant independent predictor of clinical response. Because the original
tumour size before chemotherapy (also a significant predictor of clinical and
pathological responses) was taken into account in the analyses, the results
cannot be explained in terms of psychobiological factors related to tumour size.
This study supports the importance of psychological factors as independent
predictors of response to primary chemotherapy in patients with breast cancer. If
they can be replicated, these findings have major implications for the management
of women with breast cancer. Psychological factors need to be assessed and
evaluated in future trials of chemotherapy.
PMID- 10673993
TI - The costs of managing patients with advanced colorectal cancer in 10 different
European centres.
AB - With the aim of estimating and comparing the direct hospital costs of managing
patients with advanced colorectal cancer in various countries, data on resource
utilisation and unit prices were collected. Data on the consumption of medical
resources were collected by a retrospective examination of the hospital charts
for 20 patients in each of 10 centres in five European countries. To make cost
comparisons meaningful, a complete and consistent set of unit prices for all the
medical resources used in each of the countries would be required, but this could
not be achieved. As an alternative method of comparison, the most complete set of
unit prices (from Belgium) was used here to estimate the imputed average total
cost of patient management in each centre. By using this approach, a summary
index was created, which reflected only differences in resource utilisation. This
index showed that there were considerable differences in the amounts of resources
used for treating these patients, between, as well as within, countries.
Differences of the same order of magnitude were found, when the treatment of
subgroups of patients, according to site and stage of disease, were examined.
PMID- 10673994
TI - Irinotecan in second-line treatment of metastatic colorectal cancer: improved
survival and cost-effect compared with infusional 5-FU.
AB - In a recent multicentre, randomised, controlled, open-label study (Rougier and
colleagues, Lancet 1998, 352, 1407-1412), irinotecan significantly increased
survival without any deterioration in quality of life compared with best
estimated infusional 5-fluorouracil (5-FU) therapy in the setting of second-line
treatment for metastatic colorectal cancer. The aim of the cost-effectiveness
analysis reported here was to compare the economic implications, from a U.K.
perspective, of replacing 5-FU therapy [either as a single agent (Lokich regimen,
B2) or in combination with folinic acid (de Gramont regimen, B1, or AIO regimen,
B3)] with irinotecan as second-line therapy for metastatic colorectal cancer.
Resource utilisation data collected prospectively during the study, supplemented
by both a questionnaire to investigators and local expert clinical opinion, were
used as a basis for estimating cumulative drug dosage, chemotherapy
administration and treatment of complications. Drug acquisition costs were
derived from the British National Formulary (March 1998), and unit costs for
clinical consultation and services were derived from relevant 1996/1997 cost
databases. Although cumulative drug acquisition costs per patient were higher
with irinotecan than with infusional 5-FU therapy, these were at least partially
offset by lower cumulative costs per patient associated with administration of
therapy and treatment of complications in the irinotecan arm than in the 5-FU
arm. Based on the incremental costs per life year gained (LYG), irinotecan was
considered to be cost-effective by commonly accepted criteria compared with
either the B1 or B2 regimens. Irinotecan was cost-saving compared with the B3
regimen (that is significant survival gain and a reduction in costs). Thus, not
only is there strong evidence for the use of irinotecan as standard second-line
therapy in metastatic colorectal cancer,but the results of this prospective
economic evaluation have shown that irinotecan also represents good value for
money in this clinical setting.
PMID- 10673995
TI - A phase II study of high-dose octreotide in patients with unresectable pancreatic
carcinoma.
AB - This report describes the results of a phase II trial to evaluate the safety,
feasibility and response of patients with irresectable, histologically proven,
stage II-IV adenocarcinoma of the pancreas receiving high-dose octreotide
treatment. Octreotide was self-administered subcutaneously (3 x 2000 micrograms
per day) by 49 patients. Therapy was discontinued after progression of the
disease. Due to the subseqment diagnosis of bile duct carcinoma and stage I
disease, 2 patients were excluded, leaving 47 evaluable patients with measurable
disease. The median Karnofsky score was 80%. 3 patients had stage II (6%), 19
stage III (40%), and 25 (53%) stage IV disease. Octreotide treatment resulted in
stable disease in 9 patients (19%) for more than 12 weeks. No complete or partial
response was observed. The median overall survival was 21.4 weeks and the median
progression-free survival 9.0 weeks. Therapy with high-dose octreotide is
feasible, well tolerated and might prolong survival. In a placebo-controlled
phase III study the effects of octreotide in patients with pancreatic cancer will
be confirmed.
PMID- 10673996
TI - Regression of AIDS-related Kaposi's sarcoma following antiretroviral therapy with
protease inhibitors: biological correlates of clinical outcome.
AB - The clinical response of AIDS-related Kaposi's sarcoma (KS) to highly active
antiretroviral therapy (HAART), a combination of human immunodeficiency virus
type 1 (HIV-1) protease and reverse transcriptase inhibitors, was studied in 11
patients, all but one with progressive KS. CD4+ cell counts, plasma HIV-1 RNA
levels, and antibody titres to lytic ORF65 and latency-associated human herpes
virus type 8 (HHV-8) proteins were determined in sequential samples. Six complete
and three partial clinical responses were achieved in a median time of 6 and 3
months, respectively, and confirmed after a median time of 16 months on HAART. 2
patients showed disease progression. A consistent decrease in HIV-1 RNA levels,
paralleled by an increase in CD4+ cell counts, was observed in all patients who
showed complete or partial clinical response; HIV-1 RNA levels remained
persistently high in the two patients who progressed, despite a change in HAART.
HHV-8 antibody titres were generally higher in patients with mucosal/visceral
involvement compared with patients with limited disease; a decrease in ORF65
antibody titre was significantly associated with a clinical response. These
results indicate that HAART is effective for AIDS-related KS; the clinical
response correlates with a decrease in plasma HIV-1 RNA levels, an increase in
CD4+ lymphocytes, and a decrease in antibodies to ORF65 HHV-8 protein.
PMID- 10673997
TI - Survival from childhood cancer in Yorkshire, U.K.: effect of ethnicity and socio
economic status.
AB - The effect of ethnicity and socio-economic status on the survival of a population
based cohort of 1979 children diagnosed with cancer between 1974 and 1995 was
investigated. Ethnicity was assigned by computer algorithms and visual inspection
as south Asian (or not) for each child, based on their full name. Socio-economic
status was measured using the Carstairs index, based on census areas of case
residence at diagnosis. 15 children (0.8%) were lost to follow-up. Log-rank tests
showed survival from all cancers did not differ between south Asians and other
children and no increased risk was observed for south Asians in any diagnostic
category, although numbers were small. Increasing levels of deprivation were
associated with significant trends of poorer survival from all cancers,
leukaemias and brain tumours. Risk of death was typically higher for children
from the most deprived areas although differences were not statistically
significant after accounting for other factors including ethnicity. Taking all
children with malignant disease together, neither ethnicity nor socio-economic
status appear to influence survival after taking other factors into
consideration.
PMID- 10673998
TI - Frequency and nature of germline Rb-1 gene mutations in a series of patients with
sporadic unilateral retinoblastoma.
AB - Constitutional Rb-1 gene mutations were studied in a series of 17 families with
isolated unilateral retinoblastoma patients. Peripheral blood lymphocytes were
analysed by karyotyping, Southern blot hybridisation, and 'exon by exon'
sequencing. Mutations were detected in 4 (24%) of the investigated probands. All
mutations were identified by sequencing. No alteration was detected by Southern
blotting or karyotyping. In one of our cases with a R358 stop codon mutation,
retinoblastoma was unilateral at the time of diagnosis, but a tumour of the
second eye was diagnosed after 35 months of follow-up. After exclusion of this
case, the frequency of constitutional mutations in our series was 19% (3 of 16
cases). Alterations in our cases without involvement of the second eye included G
->A substitution in the promoter region 198 bp upstream of the initiating
methionine codon; G-->C transversion in the splice donor site at position +1
leading to exon 6 skipping and a 137 bp in-frame deletion, starting 3 bp from the
5' end of exon 15 to 27 bp from the 3' end of exon 16. All alterations were
germline de novo abnormalities.
PMID- 10673999
TI - Histological determinants for different types of local recurrence after breast
conserving therapy of invasive breast cancer. Dutch Study Group on local
Recurrence after Breast Conservation (BORST)
AB - The purpose of this study was to determine which histological factors are
associated with an increased risk for local recurrence in the breast after breast
conserving therapy for early breast cancer (TNM stage I and II) and whether risk
patterns vary according to menopausal status and type of local recurrence.
Through complete follow-up of the patients of eight regional radiation oncology
departments, two cancer institutes and one surgical clinic in The Netherlands,
360 patients were identified with local recurrence in the breast after having
received breast-conserving therapy (local tumour excision, axillary dissection
and irradiation of the whole breast and a boost to the tumour bed) during the
1980s. For each case, two controls with a follow-up of similar duration without
local recurrence were randomly selected. Histological slides of the primary
tumour were reviewed. Among premenopausal patients the risk of recurrence for
those younger than 35 years was significantly higher than that for premenopausal
patients of 45 years or older (relative risk (RR) 2.9; 95% confidence interval
(95% CI) 1.3-6.6, P < 0.05). The risk of recurrence at or near the site of the
primary tumour was most significantly increased for patients with high grade
extensive intraductal component (EIC) adjacent to the primary tumour (RR 4.1; 95%
CI 1.7-9.8, P < 0.01). Microscopic margin involvement was an important risk
indicator for diffuse recurrence and recurrence in the skin of the breast,
especially in the presence of vascular invasion (RR 25; 95% CI 4.0-150, P <
0.001). To prevent local recurrence at or near the site of the primary tumour,
local excision with a 1-2 cm margin of healthy tissue and a 15 Gy boost seemed
adequate local treatment for patients with well differentiated EIC. In contrast,
a wider surgical margin, a higher boost dose or mastectomy should be considered
for patients with poorly differentiated EIC. Microscopic margin involvement in
the presence of vascular invasion significantly increases the risk of diffuse
recurrence or recurrence in the skin.
PMID- 10674000
TI - Allergy and other selected diseases and risk of colorectal cancer.
AB - It has been reported that allergy and other diseases may be related to colorectal
cancer risk. The aim of this study was to perform a systematic analysis using
information about medical histories specifically to see if there was any relation
between allergies or other medical conditions and colorectal cancer risk. A
multicentric case-control study was conducted in six Italian areas between 1992
and 1996 on 1225 incident cases of colon cancer, 728 cases of rectal cancer and
4154 controls comparable with cases according to sex and age group, admitted for
acute conditions to the same network of hospitals where cases had been
identified. Unconditional logistic regression models including terms for sex,
age, study centre, years of education, body mass index, physical activity,
smoking, history of colorectal cancer in first-degree relatives and energy intake
were used to estimate the odds ratios (OR) of colon and rectal cancer according
to history of allergy and other selected diseases. The OR for history of allergy
was 0.88 (95% confidence interval, CI, 0.67-1.14) for colon and 0.64 (95% CI,
0.44-0.92) for rectal cancer, and the inverse association was stronger when
allergy was diagnosed at age 35 years or more, or less than 10 years before the
cancer diagnosis. No clear pattern emerged in strata of age and sex. History of
other selected diseases, including hypertension and cholelithiasis, was not
related to colon or rectal cancer risk, though there was a moderate increase in
the risk of colon cancer (OR = 1.18, 95% CI, 0.66-2.14) in patients with a
history of intestinal polyps. This study lends support to the hypothesis that
allergic individuals may be at a lower risk of developing colorectal cancer.
PMID- 10674001
TI - Chemical hepatocarcinogenesis in transgenic mice overexpressing mature TGF beta-1
in liver.
AB - The role of transforming growth factor beta 1 (TGF-beta 1) in carcinogenesis is a
controversial issue. Certain results suggest a promoter role of this growth
factor whilst in other experimental models TGF-beta 1 seems to inhibit the
process of tumorigenesis. In an attempt to resolve this problem, we have
performed chemical hepatocarcinogenesis experiments on transgenic mice expressing
a high level of active TGF-beta 1 in their liver. Transgenic production of TGF
beta 1 did not result in spontaneous tumour formation during our observation
period. However, two carcinogens, thioacetamide and N-OH acetylaminofluorene,
were more potent in transgenic than in wild-type mice, whereas aflatoxin B1 was
equally effective in both groups. Our observations suggest that an increased
level of TGF-beta 1 in the liver does not provide protection against the effect
of chemical carcinogens.
PMID- 10674002
TI - Pharmacokinetic differences between rat tumour and lung tissues following
isolated lung perfusion with cisplatin.
AB - Isolated lung perfusion has been performed for the treatment of unresectable lung
tumours; however, the pharmacokinetics of this procedure remain unclear. This
study was conducted to investigate the changes in antitumour drug concentrations
in tumour and lung tissues after isolated lung perfusion, using different
perfusion times and perfusate drug concentrations. Isolated left lungs were
perfused for 20, 40 or 60 min with 25, 50 or 100 micrograms/ml of cisplatin after
solitary lung tumour nodules were established in rats, and the total platinum
concentrations in the perfused lung and tumour tissues were determined by
flameless atomic absorption spectroscopy. The oedema in the perfused lung tissues
was evaluated by histological examination and by the wet to dry weight ratios of
the lungs. The total platinum concentration increased significantly with
perfusion time and increasing perfusate cisplatin concentrations in the lung
tissue, but it did not change in the tumour tissue. The wet to dry weight ratios
of the lung tissues did not differ significantly among the perfusion groups.
Oedema of the perfused lung tissue did not change significantly with the
perfusion time or perfusate cisplatin concentration. The results of this study
indicate the possibility that different pharmacokinetics exist between tumour and
lung tissues following isolated lung perfusion with cisplatin, which could be
used as a clinical guide for the selection of appropriate perfusion times and
perfusate drug concentrations.
PMID- 10674003
TI - Sequence-dependent growth inhibition and DNA damage formation by the irinotecan-5
fluorouracil combination in human colon carcinoma cell lines.
AB - We evaluated irinotecan (CPT-11) together with 5-fluorouracil (5-FU) for improved
cell growth inhibition with respect to that by either agent alone in the human
colon carcinoma cell lines SW620, HT-29 and SNU-C4. Cells were exposed for 24 h
to each drug, as well as to various combinations and sequences of low, fixed
doses of one drug with higher varying doses of the other, cultured for two more
days in drug-free medium and then assessed for growth response with the
sulphorhodamine B assay. Multiple drug effect analysis was used to evaluate the
data, which were then related to the amount of DNA damage occurring in the cells
which was determined by a fluorescence-enhancement assay for DNA unwinding.
Cellular responses were also related to thymidylate synthase topoisomerase I and
carboxyl esterase activities, which were assessed by a ligand-binding and a 3H
release assay; a DNA decatenation assay; and a spectrophotometric method,
respectively. IC50 values for 5-FU alone in the SW620, HT29 and SNU-C4 cells were
15.3 +/- 0.8, 8.2 +/- 1.3 and 2.2 +/- 0.7 microM, respectively, and for CPT-11
2.0 +/- 0.9, 2.5 +/- 0.5 and 3.8 +/- 0.3 microM, respectively. The differential
responses to 5-FU alone were possibly determined by differences in substrate
affinity and conversion rate of thymidylate synthase (K(m) of approximately 7.5,
5.0 and 2.5 microM and V0 of approximately 800, 200 and 2400 microM/h,
respectively). The comparable cellular responses to CPT-11 alone might be
accounted for by the counterbalancing effects of differences in topoisomerase I
(1, 1, and 1.5 arbitrary units, respectively) and carboxyl esterase activities
(5055 +/- 1789, 4080 +/- 752, 1713 +/- 522 mU/mg, respectively). IC20 CPT-11
prior to 5-FU was additive to synergistic in SW620, HT-29 and SNU-C4 cells (CIs
of 0.7 +/- 0.1). By contrast, pre-treatment with IC20 5-FU antagonised the CPT-11
mediated growth inhibition (CIs of 1.9 +/- 0.4, 1.7 +/- 1.1, 2.5 +/- 0.9,
respectively). Simultaneous drug treatment did not produce more cell growth
inhibition than either drug alone in the SW620 and the HT-29 cells, but was
additive or antagonistic in the SNU-C4 cells (CIs of 1.1 +/- 0.3 and 2.2 +/-
1.4), depending on the ratio of the drugs. Increased DNA damage in the SW620 and
HT-29 cells was only seen when IC20 CPT-11 preceded IC50 5-FU, resulting in
approximately 40 and 25%, respectively, more lesions than for IC50 5-FU alone. In
the SNU-C4 cells, not only such a treatment, but also simultaneous drug treatment
produced (30 to 60%) more DNA damage than either drug alone. Our results show
clear sequence-dependent antiproliferative effects and DNA damage formation by
CPT-11 and 5-FU at combinations of low, fixed doses with higher, varying doses in
cultured human colon carcinoma cells, and may be of relevance to the design of
improved chemotherapeutic regimens in this disease.
PMID- 10674004
TI - Treatment of normal and malignant cells with nucleoside analogues and etoposide
enhances deoxycytidine kinase activity.
AB - Deoxycytidine kinase (dCK), one of the rate-limiting enzymes in the intracellular
metabolism of many antileukaemic drugs, was shown to be stimulated after
treatment of human tonsillar lymphocytes by 2-chloro-2'-deoxyadenosine
(cladribine, CdA) (Sasvari-Szekely, et al., Biochem Pharmacol 1998, 56, 1175
1179). Here we present a comparative study of different normal and malignant
cells in respect to the activation of dCK by CdA. G-phase lymphocytes showed a
higher sensitivity for dCK stimulation than S-phase cells. Normal and leukaemic
peripheral blood mononuclear cells, as well as the promyelocytic cell line HL60
responded to CdA treatment by a 2-5-fold increase in activity of dCK. However, no
significant stimulation was detected either in CCRF-CEM T-lymphoblastoid cells,
or in K562 myeloid cells. Thymidine kinase (TK) activity was not stimulated in
any cases. Treatment of these cells with several other analogues beside CdA, such
as 2-chloro-2'-arabino-fluoro-2'-deoxyadenosine (CAFdA), 2-fluoro-1-beta-D
arabinosyladenine (Fludarabine, FaraA) and 1-beta-D-arabinosylcytosine
(cytarabine, araC) gave similar results to CdA treatment. Enhancement of dCK
activity could also be achieved with the topoisomerase II inhibitor, etoposide.
In contrast, 2-chloro-riboadenosine (CrA) had no effect on the dCK at
concentrations of 10 microM or less, while dCyd and 5-aza-dCyd caused slight
inhibition. These results indicate that treatment of cells with several
inhibitors of DNA synthesis potentiates the dCK activity. The drugs widely differ
in their stimulatory effect on dCK, and there are also 'responsive' and 'non
responsive' cells with respect to dCK activation. Thus, enhancement of the dCK
activity by specific drugs in 'responsive' cells might give a rationale for
combination chemotherapy.
PMID- 10674005
TI - Tamoxifen added to adjuvant chemotherapy in premenopausal women with early breast
cancer: is it standard practice or still a subject for study?
PMID- 10674006
TI - Selective oestrogen receptor modulation: molecular pharmacology for the
millennium.
AB - Knowledge of the mechanism of action and pharmacology of tamoxifen and
raloxifene, for the prevention of breast cancer and osteoporosis respectively,
has opened the door for the discovery of multifunctional medicines. There is now
the potential to prevent osteoporosis, coronary heart disease, breast and
endometrial cancer in postmenopausal women with elevated risk factors.
PMID- 10674007
TI - Should chemotherapy be used as a treatment of advanced colorectal carcinoma (ACC)
in patients over 70 years of age?
PMID- 10674008
TI - Selection of markers to predict tumour response or survival: description of a
novel approach.
PMID- 10674009
TI - Alcohol intake and late-stage promotion of breast cancer.
AB - Breast cancer risk in women rises with increasing alcohol intake and is widely
assumed to be mediated by increased oestrogen concentrations. However,
observations that mechanisms and risk are likely to differ between pre- and
postmenopausal women suggest that the postmenopausal disease in particular, may
involve a promoting role for concomitants of hyperinsulinaemia which is commonly
associated with alcoholic cirrhosis of the liver. The MEDLINE database and
ongoing studies were examined for clinical, epidemiological and laboratory data
on; (a) alcohol-related increase in the incidence of breast cancer in relation to
menopausal status, oestrogen concentrations and the oestrogen receptor (ER)
status of the tumour; (b) activation of insulin-like growth factor 1 receptor
(IGF1R) in mammary tissue by alcohol-related hyperinsulinaemia; (c) interaction
between ER and IGF1R in breast cancer cell systems. Epidemiological association
between alcohol intake and increased breast cancer risk is more clearly seen in
postmenopausal than premenopausal women, and a significant risk is associated
with intake of more than two drinks (over 30 g) daily over a period of years.
Alcohol-related hyperinsulinaemia is reported to increase with increasing degrees
of cirrhosis and damage to liver function. Laboratory evidence suggests that
hyperinsulinaemia can stimulate expression of IGF1R in mammary tissue, and this
protein is likely to have a crucial role in mitogenesis and transformation to an
oestrogen-independent malignant phenotype. It is postulated that in women with a
history of long-term intake of moderate quantities of alcohol, the concomitants
of hyperinsulinaemia may help to stimulate progression in precancerous breast
lesions in the years leading up to the menopause and may increase the risk of
breast cancer manifesting after the menopause.
PMID- 10674010
TI - Tamoxifen in high-risk premenopausal women with primary breast cancer receiving
adjuvant chemotherapy. Report from the Danish Breast Cancer co-operative Group
DBCG 82B Trial.
AB - Following modified radical mastectomy, pre- and perimenopausal (amenorrhoea for <
5 years) patients with stage II or III breast cancer received CMF
(cyclophosphamide 600, methotrexate 40, 5-fluorouracil 600 mg/m2 intravenously
(i.v.) every 4 weeks, 9 cycles). The effect on recurrence-free survival (RFS) and
overall survival (OS) of the addition of adjuvant tamoxifen (TAM) to adjuvant
chemotherapy was examined by randomisation either to no additional treatment (n =
314), or concurrently TAM 30 mg daily for 1 year (n = 320). 40% had positive, 12%
negative and 48% unknown receptor status. One year after surgery 21% versus 35%
(CMF + TAM versus CMF) were still menstruating (P < 0.01). With a median follow
up of 12.2 years there was no difference in RFS (10-year RFS 34% versus 35%, P =
0.81) or OS (45% versus 46%, P = 0.73). In a Cox proportional hazards model,
tumour size, number of metastatic lymph nodes, frequency of metastatic nodes in
relation to total number of nodes removed, degree of anaplasia, age, and
menostasia within the first year after operation were significant independent
prognostic factors for RFS, and the same factors except age for OS. No
significant interactions with TAM were seen. Thus, in this group of pre- and
perimenopausal high-risk early breast cancer patients with heterogeneous receptor
status given CMF i.v., concurrent TAM for 1 year did not improve the outcome.
These results do not exclude that receptor positive patients may benefit from
adjuvant TAM for longer periods given sequentially to chemotherapy.
PMID- 10674011
TI - Caring About Women and Cancer (CAWAC): a European survey of the perspectives and
experiences of women with female cancers.
AB - This paper reports on the findings of the largest ever European survey of female
patients' perceptions of their cancer treatment. It has provided clarification of
what women consider important in relation to their management and has identified
several areas where more research is needed. It has shown that women's knowledge
about cancer before diagnosis is poor and the number undergoing regular screening
could be improved. Women are not being adequately prepared and educated about
what to expect from treatment and steps should be taken as a matter of urgency to
redress this shortcoming. It was revealed that whilst families were the primary
source of support to female cancer patients, women also derive considerable
support from healthcare professionals, particularly senior doctors; more
attention should be paid by specialists and nurses to developing psychological
skills to cope with this. In this context, further research is needed into how
support groups may best meet patient needs.
PMID- 10674012
TI - Differential prognosis of replication error phenotype and loss of heterozygosity
in sporadic colorectal cancer.
AB - Several distinct genetic alterations have been associated with colorectal
tumorigenesis. This study investigated the frequency of microsatellite
instability, also known as replication error (RER), and loss of heterozygosity
(LOH) at six chromosome regions in sporadic colorectal cancer (CRC). Eighty-six
tumour and paired normal mucosa samples were included in the study. A polymerase
chain reaction (PCR)-based technique was performed to analyse six (CA)n
dinucleotide repeats located near or within regions containing important genes
implicated in the complex process of colorectal tumorigenesis (chromosomes 2p,
3p, 5q, 11p, 17p and 18q). Overall, LOH frequency was higher in RER-tumours
(25/46, 54.3%) compared with RER+ tumours (9/40, 22.5) (P = 0.04). To investigate
prognostic implications, survival analysis was performed for 66 patients.
Compared with RER- tumours, patients with RER+ tumours at 2p, 3p, 5q, 11p or 18q
were found to have an improved prognosis (overall survival, P = 0.02 and disease
free survival (DFS) P = 0.005) this variable being an independent prognostic
factor by multivariate analysis (P = 0.001). Overall survival of patients whose
tumours were LOH+ was significantly shorter compared with those without LOH
(overall survival, P = 0.008 and DFS, P = 0.01). Thus, tumours displaying RER+
and LOH+ phenotype, as established by microsatellite analysis, show a
differential prognosis. These data indicate that this may be a useful tool for
the identification of patients at different risks affected by CRC.
PMID- 10674013
TI - TP53 gene mutation status in pretreatment biopsies of oesophageal adenocarcinoma
has no prognostic value.
AB - Identification of markers which help to predict response to treatment and overall
survival at the time of diagnosis would assist in the management of patients with
oesophageal adenocarcinoma. In the present study we investigated the prognostic
significance of mutations to the TP53 tumour suppressor gene in a large,
consecutive series of oesophageal adenocarcinomas. The incidence of TP53 mutation
determined by molecular analysis of endoscopic biopsy specimens was 36% (49/135).
No statistically significant difference was observed in patient survival
according to the TP53 status of the tumour biopsy. The median survival time for
patients with mutation was 12 +/- 1 months compared with 14 +/- 2 months for
patients with TP53. These results demonstrate that mutation of the TP53 gene is
not a useful predictive marker for patient survival in oesophageal
adenocarcinoma.
PMID- 10674014
TI - Decreased toxicity and increased efficacy of cancer chemotherapy using the pineal
hormone melatonin in metastatic solid tumour patients with poor clinical status.
AB - Melatonin (MLT) has been proven to counteract chemotherapy toxicity, by acting as
an anti-oxidant agent, and to promote apoptosis of cancer cells, so enhancing
chemotherapy cytotoxicity. The aim of this study was to evaluate the effects of
concomitant MLT administration on toxicity and efficacy of several
chemotherapeutic combinations in advanced cancer patients with poor clinical
status. The study included 250 metastatic solid tumour patients (lung cancer,
104; breast cancer, 77; gastrointestinal tract neoplasms, 42; head and neck
cancers, 27), who were randomized to receive MLT (20 mg/day orally every day)
plus chemotherapy, or chemotherapy alone. Chemotherapy consisted of cisplatin
(CDDP) plus etoposide or gemcitabine alone for lung cancer, doxorubicin alone,
mitoxantrone alone or paclitaxel alone for breast cancer, 5-FU plus folinic acid
for gastro-intestinal tumours and 5-FU plus CDDP for head and neck cancers. The 1
year survival rate and the objective tumour regression rate were significantly
higher in patients concomitantly treated with MLT than in those who received
chemotherapy (CT) alone (tumour response rate: 42/124 CT + MLT versus 19/126 CT
only, P < 0.001; 1-year survival: 63/124 CT + MLT versus 29/126 CT only, P <
0.001). Moreover, the concomitant administration of MLT significantly reduced the
frequency of thrombocytopenia, neurotoxicity, cardiotoxicity, stomatitis and
asthenia. This study indicates that the pineal hormone MLT may enhance the
efficacy of chemotherapy and reduce its toxicity, at least in advanced cancer
patients of poor clinical status.
PMID- 10674015
TI - Bone mineral density in children with acute lymphoblastic leukaemia.
AB - Bone mineral density (BMD) may be negatively affected by the disease or its
treatment in patients with acute lymphoblastic leukaemia (ALL). Therefore, we
evaluated lumbar spine and total body BMD and bone metabolism in children with
ALL at diagnosis, during treatment with chemotherapy and 1 year after completion
of treatment. 32 children (21 boys and 11 girls) participated in the study. 14
children started the study at diagnosis and 18 during or after the treatment
period. Lumbar spine and total body BMD were measured with dual energy X-ray
absorptiometry, and expressed as standard deviation scores (SDS). Blood samples
were obtained to assess bone metabolism. 3 of 14 children had low lumbar spine
BMD (< -2 S.D.) at diagnosis. All children had normal total body BMD. Markers of
bone turnover were depressed. Total body BMD SDS decreased significantly during
the first year of treatment (P < 0.001). Lumbar spine BMD SDS did not change
significantly. Parameters of bone turnover increased to normal during the
treatment period. Parathyroid hormone had increased significantly after 1 year (P
< 0.05). Mineral homeostasis was disturbed in some patients during treatment. 4
of 9 patients had low total body BMD and 1 patient low lumbar spine BMD one year
after completion of treatment. All patients had normal biochemical results at
that time. In conclusion, lumbar spine BMD and bone turnover were decreased in
some patients at diagnosis. Total body BMD decreased significantly during
treatment and was low in 4 of the 9 patients 1 year after completion of the
treatment.
PMID- 10674016
TI - Local therapy and other factors influencing site of relapse in patients with
localised Ewing's sarcoma. United Kingdom Children's Cancer Study Group (UKCCSG).
AB - Relapse patterns have been documented in 191 children with localised Ewing's
sarcoma treated with the United Kingdom Children's Cancer Group (UKCCSG) Ewing's
Tumour regimen ET2. All received chemotherapy comprising ifosfamide, vincristine,
doxorubicin and actinomycin D. Local treatment modality was excision and or
radiotherapy depending on tumour site and response to primary chemotherapy.
Although not strictly comparable, due to the clinical indications used for each
modality, local relapse rates were very low and were similar, irrespective of the
type of local treatment modality: radiotherapy (3/56), surgery (7/114) or a
combination (0/20). Combined relapse (local + distant) rates were similarly low
irrespective of the type of local therapy: radiotherapy (4/56), surgery (4/114)
or a combination (0/20). Overall survival was lower in females (P = < 0.04),
older children (P = < 0.002) and those with primaries at sites other than long
bones (P = < 0.02). It is concluded that with effective intensive chemotherapy
combined with either radiotherapy or surgery, local control in this study was
excellent at sites other than the pelvis. Preventing distant relapse,
predominantly to lung and bone, remains the major challenge.
PMID- 10674017
TI - Epidemiological aspects of soft tissue sarcomas (STS)--consequences for the
design of clinical STS trials.
AB - The purpose of the study was to gain insight into epidemiological aspects of soft
tissue sarcomas (STS), based on the population-based cancer registry of the
Comprehensive Cancer Center North-Netherlands (CCCN), and to provide data for the
development of future STS clinical trials. 456 primary STS (Kaposi, urogenital
and gastro-intestinal STS excluded), registered from 1989 to 1995 by the cancer
registration of the Comprehensive Cancer Center North-Netherlands (CCCN), were
analysed. The annual, age-adjusted, STS incidence was 3.6 per 100,000. Incidence
increased with age. Half of the patients were over the age of 65 years. Malignant
fibrous histiocytomas and liposarcomas were most frequently encountered. At
presentation, nodal involvement was rare (3-8%). Distant metastases were more
frequently encountered (9-14%), and appeared to be related to tumour size and
site. Above 70 years of age, 16% of patients received no treatment at all,
especially for metastatic disease.
PMID- 10674018
TI - Descriptive epidemiology of soft tissue sarcomas in Vaud, Switzerland.
AB - Trends in incidence and survival from soft tissue sarcomas (STS) were analysed
for the period 1974-1994 using data from the Cancer Registry of the Swiss canton
of Vaud. A total of 645 cases were registered. The most common histotypes were
fibrosarcoma (0.82/100,000 males, 0.86/100,000 females, world standard, 1990
1994), leiomyosarcoma (0.90/100,000 males, 1.28/100,000 females, 1990-1994), and
Kaposi's sarcoma (3.10/100,000 males in 1990-1994). Overall incidence rates for
STS increased from 2.68/100,000 males in 1974-1979 to 6.86 in 1990-1994, and from
3.61 to 4.27 in females. However, after excluding Kaposi's sarcoma, no consistent
trend over time was observed, peak rates (approximately 4.40/100,000) being
registered in the late 1980s for both sexes, with some levelling off thereafter.
Five-year relative survival was 17% for Kaposi's sarcomas, and 51% for other STS
(all STSs, 45%). These data indicate that there has been no major new risk factor
for STS of such a relevance to modify appreciably the overall rates on a
population level, except from the impact of the AIDS epidemic for Kaposi's
sarcoma.
PMID- 10674019
TI - Vitamin D analogues suppress IGF-I signalling and promote apoptosis in breast
cancer cells.
AB - Survival factors are known to promote cell viability, and factor deprivation can
be a potent apoptotic signal. Insulin-like growth factors are potent mitogens and
inhibitors of apoptosis for many normal and neoplastic cells with insulin-like
growth factor-I (IGF-I) being the most effective in many breast cancer cell
lines. 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and its analogues inhibit IGF-I
stimulated growth of MCF-7 human breast cancer cells. The aim of this study was
to determine the relationship between inhibition of IGF-I responsiveness and
induction of apoptosis by vitamin D analogues in breast cancer cells. Vitamin D
analogues EB1089 and CB1093 inhibited autonomous and IGF-I-stimulated growth of
MCF-7 and T47D cells and autonomous growth of IGF-I-insensitive Hs578T cells. In
MCF-7 cells, IGF-I alone (4 nM) protected against apoptosis mediated by serum
deprivation. Co-treatment with vitamin D analogues prevented the anti-apoptotic
effects of IGF-I. In T47D cells, IGF-I treatment provided only partial protection
against apoptosis induced by serum deprivation and co-incubation of serum
deprived cells with 100 nM CB1093 and IGF-I abrogated this partial protection. In
Hs578T cells, addition of IGF-I did not prevent apoptosis induced by serum
deprivation. However, treatment with CB1093 attenuated the protective effect of
the serum in these cells. Our findings suggest that vitamin D analogues inhibit
IGF-I signalling pathways to promote apoptosis in breast cancer cells.
PMID- 10674020
TI - Mutations in hMSH6 alone are not sufficient to cause the microsatellite
instability in colorectal cancer cell lines.
AB - Microsatellite instability (MSI) at simple repeated sequences characterises a
distinct mechanism of carcinogenesis in hereditary nonpolyposis colorectal cancer
(HNPCC), as well as sporadic colorectal cancers displaying MSI. Such MSI is
associated with mutations of hMSH2 and hMLH1, and somatic frameshift mutations in
TGF-beta RII, IGFIIR, BAX, hMSH3 and hMSH6 at simple repeated sequences in coding
regions. The aim of this study was to look for a correlation between mutations in
mismatch repair genes and frameshift mutations in colorectal cancer cell lines
with MSI. Using 22 colorectal cancer cell lines, we examined the MSI status at
mononucleotide repeat microsatellite markers and mutations in hMSH2 and hMLH1,
TGF-beta RII, IGFIIR, BAX, hMSH3 and hMSH6. Thirteen of 22 lines (59%) displayed
MSI. In these 13 lines showing MSI, 10 lines (77%) had mutations in TGF-beta RII,
nine lines (69%) in BAX, seven lines (54%) in hMSH6, and six lines (46%) in
hMSH3, while mutations in the IGFIIR gene were identified in only two lines
(15%). Of the 13 lines with MSI, six lines (46%) harboured mutations/deletions in
hMSH2 (two nonsense mutations, three deletions and one no expression of
transcripts) and three of these cell lines (50%) had mutations both in the hMSH2
and hMSH3 genes. Two cell lines (15%) had mutations/deletions in hMLH1 (one
missense mutation and one deletion) and these two cell lines also had mutations
in hMSH3. One line had a mutation in hMSH3 only, although this line showed MSI
and had mutations in TGF-beta RII, IGFIIR and BAX. All lines with mutations in
hMLH1, hMSH2, TGF-beta RII, IGFIIR, BAX and hMSH3 genes showed MSI. However, of
the nine lines without MSI, two (22%) had homozygous mutations in hMSH6. In these
two cell lines, no mutations were identified in hMLH1, hMSH2, TGF-beta RII,
IGFIIR, BAX and hMSH3. Our results indicate that mutations in hMLH1, hMSH2 and
hMSH3 are associated with MSI, but mutations in hMSH6 are not. We conclude that
mutations in hMSH6 alone are not sufficient to cause MSI, although protein
functional effects of these mutations should still be examined.
PMID- 10674021
TI - Loss of heterozygosity at chromosome 13q in hepatocellular carcinoma:
identification of three independent regions.
AB - Loss of heterozygosity (LOH) on chromosome 13q is one of the most common genetic
alterations in hepatocellular carcinoma (HCC) and might be involved in liver
cancer development through inactivation of tumour suppressor genes. In order to
narrow down the region of 13q loss, we examined the pattern of loss of
heterozygosity (LOH) in tumours from 88 HCC patients, using 18 microsatellite
markers on 13q. Thirty-eight of the 88 tumours (43%) showed LOH for at least one
marker. Of these, two tumours (5%) showed 13q whole arm allelic loss, while the
remaining 36 tumours (95%) had partial allelic loss. The LOH pattern defined by
the 36 tumours suggested the existence of at least three different smallest
common deleted regions which might be involved in the carcinogenesis of HCC. The
first, the most centromeric in the 13q12.3 is, close to the BRCA2 gene, defined
by D13S171; the second, the most telomeric region in the 13q31-32 band, is
defined by D13S154 and D13S157; the third, the intermediate region at 13q14.3,
which is near the RB gene, is defined by loci D13S268. The rate of LOH at 13q31
32 was significantly higher in Hepatitis B-surface antigen (HBsAg)-positive
patients than HBsAg-negative HCC patients, pointing to a candidate gene related
to the development of HBsAg-positive HCCs.
PMID- 10674022
TI - Suppressive subtractive hybridisation reveals differential expression of
serglycin, sorcin, bone marrow proteoglycan and prostate-tumour-inducing gene I
(PTI-1) in drug-resistant and sensitive tumour cell lines of haematopoetic
origin.
AB - The development of therapy-induced drug resistance is still one of the most
important therapeutic limitations. Nevertheless, an integrating view of the
molecular mechanisms underlying resistance development in general is missing. In
order to shed some light on the network of this resistance development, we
established drug-resistant (doxorubicin (DX), methotrexate (MTX), cisplatin
(cisPt), vincristine (Vin)) derivatives of six tumour cell lines (Jurkat, U937,
HL60, DoHH-2, K562 and ARH77) of haematopoetic origin. Differential gene
expression of drug-sensitive parental cell lines and the drug-resistant
derivatives thereof was analysed by suppressive subtractive hybridisation. After
dot blot screening for differential expression and sequencing of the cloned PCR
fragments, differential expression was confirmed by Northern blot analysis. In an
attempt to discriminate for differentially expressed genes only related to one or
the other of the investigated drugs, the cDNAs of various resistant sublines
(doxorubicin-, methotrexate-, cisplatin-resistant Jurkat cells) were pooled and
compared with the sensitive parental cell line. In addition, cDNAs of the
resistant derivatives of the different haematopoetic tumour cell lines were
pooled and compared with the pooled cDNAs of the corresponding sensitive
haematopoetic cell lines to eliminate cell line to cell line variations that were
not related to drug resistance. As a result of this screening, the following
genes showed a higher (at least 2-fold) or exclusive expression in the drug
resistant variants: serglycin, sorcin, BMPG (bone marrow proteoglycan gene) and
PTI-1 (prostate-tumour-inducing gene 1). In addition, elevated expression of
hsp90, previously found by our group to be upregulated in the drug-resistant
colon carcinoma cell line LoVo H67P was found to be overexpressed in drug
resistant HL60 cells.
PMID- 10674023
TI - Comments on: Tagging sentinel lymph nodes: a study of 100 patients with breast
cancer. Bobin, et al., Eur J Cancer 1999, 35, 569-573.
PMID- 10674024
TI - Detection of drug misuse--an addictive challenge.
AB - It is now accepted that drug misuse is a large and growing problem in the United
Kingdom, some estimates of the number of regular illicit drug users being as high
as three million. The aim of this paper is to provide insight into the methods
used to detect drug misuse. The strategy adopted by one laboratory is described
and methods of screening for, and identification of, a wide range of compounds
are provided. No claim is made that this is the best approach or that the list of
drugs detected is comprehensive; the range of drugs encountered is always
increasing and the lists are constantly updated. It is hoped that users of
toxicology laboratory services will gain an appreciation of the capabilities and
limitations of the techniques available; and that those who may wish to provide
such a service will find the necessary information in a readily accessible
format.
PMID- 10674025
TI - Biological consequences of the BCR/ABL fusion gene in humans and mice.
PMID- 10674026
TI - Next of kin clinics: a new role for the pathologist.
PMID- 10674027
TI - Detection of telomerase in hepatocellular carcinomas using a PCR ELISA assay:
comparison with hTR expression.
AB - BACKGROUND: While telomerase is undetectable in most normal somatic tissues,
telomerase activation has been detected in many immortal cell lines and various
cancers. AIM: To investigate telomerase expression in hepatocellular carcinoma,
and to assess the expression of the RNA component of telomerase, hTR. METHODS: 39
hepatocellular carcinomas were studied using a telomerase polymerase chain
reaction (PCR) enzyme linked immunosorbent assay, which does not require
radioactive PCR amplification and yields a semiquantitative measurement.
Expression of hTR was also assessed by a non-radioactive in situ hybridisation
procedure. The correlations between these two markers and the clinicopathological
data were analysed. RESULTS: Telomerase activity was detected in 23 of 39
hepatocellular carcinoma specimens (59%). Comparison of hepatocellular carcinoma
with and without telomerase expression, or with high and low telomerase (10 cases
v 13 cases), showed no differences in the principal clinicopathological data.
Although median survival was lower in the group with detectable telomerase
activity than in that with undetectable activity (510 v 720 days) the difference
was not significant (log-rank test, p = 0.08). hTR expression was detected in 11
of 14 cases of hepatocellular carcinoma tested (78%) and in four of 12 samples of
adjacent non-cancerous tissue (33%). Five tumours and four non-cancerous tissues
were positive for hTR, whereas no telomerase activity was detected in these.
CONCLUSIONS: The presence of telomerase activity in hepatocellular carcinomas is
confirmed. No correlation was observed between clinicopathological data and
telomerase expression in hepatocellular carcinoma, but survival seemed better in
the absence of telomerase expression. hTR seems to be more widely expressed than
telomerase.
PMID- 10674028
TI - Expression of CD44 on bile ducts in primary sclerosing cholangitis and primary
biliary cirrhosis.
AB - AIM: To examine expression of CD44, a transmembrane glycoprotein involved in
lymphocyte homing and activation, in inflammatory liver diseases. METHODS:
Formalin fixed, paraffin embedded tissues were obtained from normal, uninvolved
liver from patients undergoing partial hepatectomy for metastatic carcinoma (9)
and transplant hepatectomy specimens from patients with primary biliary cirrhosis
(12), primary sclerosing cholangitis (8), autoimmune hepatitis (3), hepatitis C
(3), and secondary sclerosing cholangitis (1). Expression of CD44 (using
antibodies to three core epitopes), HLA-DR, and lymphocyte phenotypic markers was
studied by immunohistochemistry. RESULTS: CD44 expression was not detected in
either hepatocytes or biliary epithelial cells in normal livers. In sections from
all 27 transplant hepatectomy specimens, CD44 was positive in bile duct
epithelial cells but not in hepatocytes. The proportion of CD44+ ducts was much
higher in biliary disease than in chronic hepatitis. By contrast, expression of
HLA-DR was detected in a relatively small percentage of bile ducts. Activated,
memory phenotype CD4+ T lymphocytes were increased in the parenchyma of all
diseased livers and an infiltrate of activated CD8+ cells within the biliary
epithelium was evident in inflammatory biliary disease. CONCLUSIONS: CD44 appears
to play an important role in the development of autoimmune biliary disease by
promoting lymphoepithelial interactions, whereas HLA-DR may be involved in the
subsequent progression of these conditions.
PMID- 10674029
TI - Vascular endothelial growth factor mRNA expression in minimal change, membranous,
and diabetic nephropathy demonstrated by non-isotopic in situ hybridisation.
AB - AIM: To investigate vascular endothelial growth factor (VEGF) mRNA expression in
glomerular disease in the context of heavy proteinuria. METHODS: Non
radioisotopic in situ hybridisation was performed using a cocktail of 12
deoxyoligonucleotides complementary to VEGF mRNA labelled during solid phase
synthesis with 2,4-dinitrophenyl. Archival renal biopsies were studied from cases
of minimal change nephropathy, membranous nephropathy, diabetic nephropathy, and
controls, matched for age, sex, race, and storage time. Hybrid detection used
NBT/BCIP colorimetric development. RESULTS: More VEGF mRNA positive glomerular
cells per unit cross sectional diameter were seen in minimal change nephropathy
(mean (SEM), 19.35 (1.5)) compared with controls (12.6 (1.73)), p < 0.01. In
contrast, fewer were seen in diabetic nephropathy (5.93 (0.97)) compared with
controls (9.97 (1.25)), p < 0.03. Analysis of membranous nephropathy (10 (1.62))
showed no difference from controls (10.98 (1.51)), NS. In addition, in minimal
change nephropathy there was a significant correlation between 24 hour protein
excretion at the time of biopsy and the number of VEGF mRNA cells per glomerulus
(r = 0.08, p = 0.01). CONCLUSIONS: Using non-radioisotopic in situ hybridisation,
VEGF mRNA is almost exclusively expressed by visceral glomerular epithelial
cells. Abnormal numbers of cells are seen in both minimal change and diabetic
nephropathy. As VEGF exists in a number of functionally distinct isoforms,
further study of qualitative VEGF isoform expression in diagnostic groups is
indicated.
PMID- 10674030
TI - Autoimmune markers are undetectable in end stage idiopathic dilated
cardiomyopathy.
AB - BACKGROUND: Autoreactive humoral and cellular immune responses may be involved in
the pathogenesis of idiopathic dilated cardiomyopathy (IDC). Certain human
leucocyte antigens (HLA) could also be linked to the development of IDC. AIM: To
determine whether various markers of autoimmunity are present in the final phase
of the disease, to substantiate the role of an autoimmune process in IDC.
METHODS: 37 patients with end stage IDC were studied, together with 39 patients
with end stage heart disease of known aetiology who were included for comparison.
Multiple myocardial tissue samples from the explanted heart of each patient were
evaluated (immuno)histologically. An indirect immunofluorescence assay was used
to screen patient serum samples for the presence of heart specific
autoantibodies. HLA class I and II frequencies were determined in each group and
compared with HLA frequencies from healthy blood donors. RESULTS: Only scanty
small mononuclear cell infiltrates were present in myocardial tissue of seven
patients with IDC and of 11 patients with heart disease of known cause. The
majority of these inflammatory cells were negative for T cell markers. All blood
specimens were negative for heart specific autoantibodies and there was no
apparent association of IDC with particular HLA phenotypes. CONCLUSIONS: These
findings suggest that an active autoimmune process is not involved in the end
stage of IDC.
PMID- 10674031
TI - The effects of freeze drying and freeze drying additives on the prothrombin time
and the international sensitivity index.
AB - AIM: To determine whether freezing, freeze drying protective additives, or freeze
drying of plasma samples from patients on coumarin treatment and from normal
individuals affects prothrombin times or the international sensitivity index
(ISI) calibration. METHODS: The effect of the addition of the protective
additives singly and combined on the prothrombin time of coumarin samples and
normal samples before and after freeze drying was observed using high and low ISI
reference thromboplastins. ISI values were also determined. RESULTS: Freezing
caused a prolongation of prothrombin time in the normal plasma samples with both
reagents, which was significant with the low ISI human. Prolongation (non
significant) of the prothrombin time in coumarin plasma samples occurred with the
human reagent only. Significant prolongation of normal prothrombin time by some
of the protective additives before and after freeze drying was observed with both
thromboplastins but to a greater extent with the human. Significant prolongation
of prothrombin time in coumarin plasma samples was observed, but again was more
marked with human thromboplastin. An approximate ISI was determined on the 20
coumarin samples. The only marked ISI change was with the WHO human
thromboplastin after freeze drying of plasma, where a decrease from 0.95 to 0.90
was observed, corresponding to a marked prothrombin ratio increase. CONCLUSIONS:
Freeze drying additives and the freeze drying procedure prolong normal and
coumarin prothrombin times, with low ISI thromboplastin. Less marked
prolongations occurred with a high ISI rabbit reagent, coumarin samples showing
more significant prolongations. Marked ISI change in freeze dried plasma was only
recorded with the low ISI ECAA human reagent. Frozen normal plasma samples cannot
be used with confidence for ISI calibrations.
PMID- 10674032
TI - Postmortem prolactin as a marker of antemortem stress.
AB - AIM: To determine whether raised prolactin concentrations could be identified
using postmortem venous blood and whether the level of prolactin correlated with
antemortem stress. METHODS: Blood was obtained from the right femoral vein of 100
random adult necropsy cases, all of whom had been dead less than four days.
Prolactin was determined in the samples by microparticle immunoassay. The levels
of prolactin obtained were then analysed in relation to sex and cause of death,
with particular emphasis on a history of antemortem stress and drug use. RESULTS:
Prolactin in all cases of trauma was in the normal range (up to 500 mU/l). In
cases of sudden unexpected deaths the mean concentration was 533 mU/l (95%
confidence interval (CI), 372 to 694 mU/l). Postoperative deaths or cases with
chronic disease had a mean value of 1027 mU/l (95% CI, 735 to 1319 mU/l). Cases
of suicide had a mean value of 1398 mU/l. Analysis of the suicides by sex showed
a significant difference, the mean in female cases being 2072 mU/l compared with
692 mU/l in male cases. In three of the four female suicides with the highest
prolactin, the hyperprolactinaemia might have been attributable to a drug effect,
but one case still had unexplained hyperprolactinaemia. CONCLUSIONS: It is
possible to detect prolactin reliably in postmortem venous blood samples.
Prolactin values at necropsy differ according to the cause of death, with
markedly higher values in postoperative deaths and in the chronically ill.
Hyperprolactinaemia in cases of suicide is likely to result from the effects of
the drugs used, but the levels were higher than previously reported.
PMID- 10674033
TI - Age related prevalence of hepatitis G virus in South Africans.
AB - AIM: To investigate the age related prevalence of hepatitis G virus (HGV)
infection and its mode of transmission in relation to hepatitis B (HBV) and C
(HCV) co-infection in South African blacks. METHODS: Reverse transcriptase
polymerase chain reaction was performed to detect active infection, using primers
for the 5'-NCR, NS5a, and NS3 regions. Antibodies to HGV envelope-2 protein (anti
E2), which measures past infection, were also sought. RESULTS: The overall
prevalence of active infection was 116/580 (20%). A higher prevalence was noted
in HBsAg carriers (28/106; 26.4%) and HCV positive subjects (25/82; 30.5%). In
contrast to developed countries, active and past infection was seen in 12.9% and
12.1% of the general population, respectively (subjects negative for HBsAg and
anti-HCV markers and with normal alanine aminotransferase values), with a total
prevalence of 21.1% (52/248). Viraemia and anti-E2 were almost mutually
exclusive. The distribution of viraemia by age was: < or = 15 years, 20/223
(9.0%); 16-35 years, 42/147 (28.6%); > or = 36 years, 37/151 (24.5%), with a
significant difference (p = 0.001) in age related prevalence. A similar trend was
observed for the prevalence of past infection in the general population.
CONCLUSIONS: HGV infection begins in childhood and increases with age in South
Africa, but transmission is largely independent of HBV and HCV. No association
was found between HGV viraemia and hepatitis, or with co-infection with either
HBV or HCV.
PMID- 10674035
TI - Image sampling in static telepathology for frozen section diagnosis.
AB - BACKGROUND: A frozen section diagnostic service is often not directly available
in small rural or mountain hospitals. In these cases, it could be possible to
provide frozen section diagnosis through telepathology systems. Telepathology is
based on two main methods: static and dynamic. The former is less expensive, but
involves the crucial problem of image sampling. AIMS: To characterise the
differences in image sampling for static telepathology when undertaken by
pathologists with different experience. METHODS: As a test field, a previously
studied telepathology method based on multimedia email was adopted. Using this
method, three pathologists with different levels of experience sampled images
from 155 routine frozen sections and sent them to a distant pathology institute,
where diagnoses were made on digital images. After the telepathology diagnoses,
the glass slides of both the frozen sections and the definitive sections were
sent to the remote pathologists for review. RESULTS: Four of 155 transmissions
were considered inadequate by the remote pathologist. In the remaining 151 cases,
the telepathology diagnosis agreed with the gold standard in 146 (96.7%). There
was no significant divergence between the three pathologists in their sampling of
the images. Each case comprised five images on average, acquired in four minutes.
The overall time for transmission was about 19 minutes. CONCLUSIONS: The results
suggest that in routine frozen section diagnosis an inexperienced pathologist can
sample images sufficiently well to permit remote diagnosis. However, as expected,
the internet is too unreliable for such a time dependent task. An improvement in
the system would involve integrated real time features, so that there could be
interaction between the two pathologists.
PMID- 10674034
TI - Oesophageal mesenchymal tumours: clinicopathological features and absence of
Epstein-Barr virus.
AB - BACKGROUND: Recent studies have suggested that the Epstein-Barr virus (EBV) is
associated with smooth muscle tumours (leiomyoma and leiomyosarcoma) in patients
with human immunodeficiency virus and in organ transplant recipients. Leiomyoma
is the most common mensenchymal tumour found in the oesophagus. AIM: To report a
single institution experience on oesophageal mesenchymal tumours and to determine
whether EBV is associated with these tumours. METHODS: 40 sporadic oesophageal
mesenchymal tumours were studied and their diagnosis confirmed on pathological
review and immunohistochemical studies. Formalin fixed, paraffin was embedded
tissues from these tumours were analysed for EBV using in situ hybridisation for
two messenger RNA (mRNA) probes, EBER and BamH1 W. RESULTS: The oesophageal
mesenchymal tumours comprised 36 leiomyomas, two undifferentiated stromal
tumours, and two gastrointestinal autonomic nerve tumours (GANTs). Median age of
the patients with leiomyoma (26 men, 10 women) was 62 years (range 30 to 85) and
81% of them had an asymptomatic lesion. The median longitudinal size was 1.2 cm.
Multiple leiomyomas were seen in 11% of the patients and calcification was noted
in one tumour. Coexisting squamous cell carcinoma was found in one third of
cases. The stromal tumours were small, asymptomatic, and located in the lower
third of the oesophagus, while the GANTs were large, symptomatic, and found in
the upper third of the oesophagus. EBV mRNAs were not detected in all these
tumours. CONCLUSIONS: The clinicopathological features of oesophageal leiomyoma,
undifferentiated stromal tumour, and GANT were different. Some oesophageal
leiomyomas were associated with oesophageal squamous cell carcinomas. EBV is not
associated with sporadic oesophageal mesenchymal tumours.
PMID- 10674036
TI - Rapid detection of the factor V Leiden (1691 G > A) and haemochromatosis (845 G >
A) mutation by fluorescence resonance energy transfer (FRET) and real time PCR.
AB - A rapid method based on fluorescence resonance energy transfer (FRET) and real
time polymerase chain reaction (PCR) was used to identify the haemochromatosis
genotype in 112 individuals and the factor V genotype in 134 individuals. The
results were compared with conventional methods based on restriction enzyme
digestion of PCR products. The two methods agreed in 244 of the 246 individuals;
for the other two individuals, sequencing showed that they had been incorrectly
genotyped by the standard method but correctly genotyped by FRET. The simplicity,
speed, and accuracy of real time PCR analysis using FRET probes make it the
method of choice in the clinical laboratory for genotyping the haemochromatosis
and factor V genes.
PMID- 10674037
TI - A latex slide agglutination test for rapid detection of antimyeloperoxidase
antibody.
AB - AIM: To develop and test a new latex slide agglutination test (MPO-LSAT) to
detect antimyeloperoxidase (anti-MPO) antibody in serum. METHODS: Latex bead
coating was adjusted to give maximum sensitivity by attending to latex size, MPO
to latex ratio for coupling, ratio of diluted serum to MPO-latex, reaction time
and temperature for coupling, and reaction time for agglutination. Inhibition
studies were performed using MPO, proteinase 3, bactericidal/permeability
increasing protein, and lactoferrin. RESULTS: There was very good correlation
between this test and the conventional anti-MPO enzyme linked immunosorbent assay
(ELISA): 81% of sera positive in the ELISA were positive by MPO-LSAT. MPO-LSAT
results correlated better with IgM anti-MPO than with IgG anti-MPO. CONCLUSIONS:
MPO-LSAT is a simple diagnostic test that is potentially useful in the clinical
laboratory as a rapid screening tool for vasculitic diseases.
PMID- 10674038
TI - Review of the clinical activity of medical microbiologists in a teaching
hospital.
AB - BACKGROUND: The clinical interactive role of medical microbiologists has been
underestimated and the discipline is perceived as being confined to the
laboratory. Previous studies have shown that most microbiology interaction takes
place over the telephone. AIM: To determine the proportion of clinical ward based
and laboratory based telephone interactions and specialties using a microbiology
service. METHODS: Clinical microbiology activity that took place during November
1996 was prospectively analysed to determine the distribution of interactions and
specialties using the service. RESULTS: In all, 1177 interactions were recorded,
of which nearly one third (29%) took place at the bedside and 23% took place on
call. Interactions involving the intensive treatment unit, general ward visits,
and communication of positive blood cultures and antibiotic assays were the main
areas of activity identified. There were 147 visits to 86 patients on the general
wards during the study, with the number of visits to each individual varying from
one to eight. The need for repeated visits reflected the severity of the
underlying condition of the patients. Ward visits were regarded as essential to
obtain missing clinical information, to assess response to treatment, and to make
an appropriate entry in a patient's notes. CONCLUSIONS: Ward visits comprise a
significant proportion of clinical microbiology interactions and have potential
benefits for patient management, service utilisation, and education.
PMID- 10674039
TI - The use of histological techniques for the demonstration of ion exchange resins.
AB - AIM: To establish the staining characteristics of certain ion exchange resins in
histological material, with a view to enabling confident differential
identification. METHODS: Various histological staining procedures were applied to
selected pathological material and prepared agar blocks containing the cation
exchange resin calcium polystyrene sulphonate and the anion exchange resin
cholestyramine. RESULTS: Calcium polystyrene sulphonate uniquely stained strongly
by a direct Schiff's reagent procedure without any preoxidation and by the Ziehl
Neelsen method. Cholestyramine was negative by the former method but stained
strongly with a standard Congo red technique. CONCLUSIONS: These staining results
are consistent with the known structure and properties of polystyrene sulphonate
and cholestyramine resins. Polystyrene sulphonate resins have the virtually
pathognomonic feature of direct Schiff positivity, while morphology, location,
and strong non-birefringent Congo red positivity facilitate the identification of
cholestyramine. It is possible that the intrinsic staining characteristics of
cholestyramine may be lost once it has bound to its target.
PMID- 10674040
TI - Severe hypoglycaemia caused by raised insulin-like growth factor II in
disseminated breast cancer.
AB - A 60 year old woman with disseminated ductal carcinoma of the breast developed
non-islet cell tumour induced hypoglycaemia (NICTH). The concentrations of the
two insulin-like growth factors, IGF-I and IGF-II, were < 2 nmol/l and 94.1
nmol/l, respectively. The IGF-II to IGF-I ratio was > 47 (normal < 10). Insulin
(< 3 mu/l) and C peptide (< 100 pmol/l) were both undetectable.
PMID- 10674041
TI - Association of HLA-DRB1 alleles with giant cell tumour of bone.
AB - AIM: To examine the possible influence of the MHC class II antigens alleles in
the formation of the multinucleate aggressive giant cell tumour of bone. METHODS:
HLA class II antigen alleles were investigated in eight white patients from north
east England with confirmed diagnosis of giant cell tumour of bone. All had
locally aggressive, immunophenotypically HLA-DR negative giant cell tumours.
RESULTS: Five of the eight patients were found to be positive for HLA
DRB1*0801/3, the distribution of this allele in healthy white controls being
quite low (2%). All but one of the patients possessing DRB1*080 also expressed
DRB1*070. CONCLUSIONS: HLA-DRB1*080 is pre-dominant in patients with
immunophenotypic HLA-DR negative giant cell tumour of bone; individuals with the
genotype 070/080 are at particularly high risk of developing giant cell tumour of
bone.
PMID- 10674042
TI - Differential expression of high molecular weight caldesmon in colorectal
pericryptal fibroblasts and tumour stroma.
AB - AIM: To investigate an extent of smooth muscle differentiation of pericryptal
fibroblasts. METHODS: Expression of high molecular weight caldesmon (h-CD) and
alpha smooth muscle actin was investigated in 123 invasive colorectal
adenocarcinomas and their surrounding non-neoplastic tissues. RESULTS: The
monoclonal antibody to h-CD, which showed predominantly positive immunostaining
in well differentiated smooth muscle cells, recognised pericryptal fibroblasts,
smooth muscle cells, and pericytes, but was not reactive to myofibroblasts.
Antibody to alpha smooth muscle actin recognised not only pericryptal
fibroblasts, smooth muscle cells, and pericytes but also myofibroblasts.
CONCLUSIONS: Pericryptal fibroblasts show greater smooth muscle differentiation
than myofibroblasts and there is a possibility that they are well differentiated
smooth muscle cells; h-CD is an excellent marker to discriminate pericryptal
fibroblasts from myofibroblasts.
PMID- 10674043
TI - Follow up of women with borderline cervical smears as defined by national
guidelines.
AB - AIM: To determine the proportion of women with abnormalities in cervical smears
corresponding to borderline nuclear change, as defined by national guidelines,
which return to normal or persist as cytological or histological abnormalities.
METHODS: 313 women with borderline nuclear change diagnosed by a single
pathologist using the national criteria were followed up for up to two years.
RESULTS: On initial follow up, 45% of women had a negative smear or biopsy, 46.5%
had a low grade cytological or histological abnormality, and 8.5% had a high
grade abnormality. Of 81 patients in whom a second follow up smear or biopsy was
available, 47% had no detectable abnormality, 38.5% had low grade lesion, and
14.5% had a high grade lesion. In total, 32 patients (10.2%) had a high grade
lesion (defined as moderate or severe dyskaryosis on smear or CINII or CINIII on
biopsy) on at least one follow up sample. CONCLUSIONS: The results support the
use of the national criteria defining borderline nuclear change in identifying
women at increased risk of developing a high grade cervical intraepithelial
neoplasia, as identified histologically or cytologically, and highlight the
importance of follow up in these patients.
PMID- 10674044
TI - Cytokeratin 10/13, 14, 7, 8, and 18 in invasive squamous cell carcinoma and
adenocarcinoma of the uterine cervix.
PMID- 10674045
TI - No pain, no gain?
PMID- 10674046
TI - Support of clinical trials.
PMID- 10674047
TI - If the WCB can do it, why not others?
PMID- 10674048
TI - Real-world effectiveness of antihypertensive drugs.
PMID- 10674049
TI - Why aren't we falling for anticoagulant therapy?
PMID- 10674050
TI - Non-heart-beating organ donation.
PMID- 10674051
TI - To pay or not to pay? A decision and cost-utility analysis of angiotensin
converting-enzyme inhibitor therapy for diabetic nephropathy.
AB - BACKGROUND: Angiotensin-converting-enzyme (ACE) inhibitor therapy can
significantly delay the progression of diabetic nephropathy to end-stage renal
failure (ESRF). The main obstacle to successful compliance with this therapy is
the cost to the patients. The authors performed a cost-utility analysis from the
government's perspective to see whether the province or territory should pay for
ACE inhibitors for type I diabetic nephropathy on the assumption that cost is a
major barrier to compliance with this important therapy. METHODS: A decision
analysis tree was created to demonstrate the progression of type I diabetes with
macroproteinuria from the point of prescription of ACE inhibitor therapy through
to ESRF management, with a 21-year follow-up. Drug compliance, cost of ESRF
treatment, utilities and survival data were taken from Canadian sources and used
in the cost-utility analysis. One-way and two-way sensitivity analyses were
performed to test the robustness of the findings. RESULTS: Compared with a no
payment strategy, provincial payment of ACE inhibitor therapy was found to be
highly cost-effective: it resulted in an increase of 0.147 in the number of
quality-adjusted life-years (QALYs) and an annual cost savings of $849 per
patient. The sensitivity analyses indicated that the cost-effectiveness depends
on compliance, effect of benefit and the cost of drug therapy. Changes in the
compliance rate from 67% to 51% could result in a swing in cost-effectiveness
from a savings of $899 to an expenditure of more than $1 million per additional
QALY. A 50% reduction in the cost of ACE inhibitors would result in a cost
savings of $299 per additional QALY with compliance rates as low as 58% in the
provincial payment strategy. INTERPRETATION: Provincial coverage of ACE inhibitor
therapy for type I diabetes with macroproteinuria improves patient outcomes, with
a decrease in cost for ESRF services.
PMID- 10674053
TI - Telemedicine and fetal ultrasonography in a remote Newfoundland community.
PMID- 10674052
TI - Blood recipient notification for hepatitis C in Prince Edward Island.
AB - BACKGROUND: Two of the major risk factors for hepatitis C are injection drug use
and receipt of blood or blood products. Many patients are unaware that they have
received transfusions. In 1998 Prince Edward Island conducted a province-wide
look-back notification program to notify patients who had received transfusions
in PEI between Jan. 1, 1984, and June 1, 1990. The authors present the results of
the notification program. METHODS: A registry for recipients of blood and blood
products was created from the province's Red Cross blood bank records. The
registry data were linked with Vital Statistics data to determine death status
and with Health Registration data to determine residence status of recipients (in
PEI or moved out of province). All identified recipients with a current PEI
mailing address were sent a letter recommending hepatitis C virus (HCV) testing.
Laboratory records were checked to determine HCV test results. RESULTS: The
registry contained data for 6086 recipients of blood or blood products during the
look-back period; 51.1% (3109/6086) had died by the time of notification. Of the
remainder, 18.4% (549/2977) were not directly notified because they had moved out
of province, had refused delivery of the notification letter or had died
recently, or because identifying information was missing from the blood bank
records. Of the recipients who were notified 80.4% (1953/2428) underwent testing,
and 2.2% (43/1953) were found to be HCV positive. Most of these (58.1% [25/43])
had undergone testing before notification. The HCV positivity rate differed
significantly between recipients tested before notification and those tested
after notification (9.9% v. 1.1%, p < 0.001). HCV-positive recipients were more
likely than other notified recipients to have had multiple transfusions (39.5% v.
9.5%, p < 0.001). INTERPRETATION: Before notification 4.1% of PEI recipients had
undergone HCV testing. After notification 91.2% of PEI recipients were identified
as tested, dead or moved out of province. The notification program resulted in
the identification of the majority of PEI's transfusion-related cases of
hepatitis C.
PMID- 10674054
TI - The seroprevalence of hepatitis A and B in people testing positive for hepatitis
C.
PMID- 10674055
TI - The need for greater involvement of regulatory agencies in assessing adverse drug
reactions.
PMID- 10674056
TI - HIV testing of patients: let's waive the waiver.
PMID- 10674057
TI - Scientific harassment by pharmaceutical companies: time to stop.
PMID- 10674058
TI - The diagnosis and management of insomnia in clinical practice: a practical
evidence-based approach.
AB - Insomnia, or the dissatisfaction with the quantity, quality or timing of sleep,
is a common complaint. Because the definition of "normal" sleep is not well
established, the estimates of the prevalence and severity of insomnia vary
widely. Insomnia is often secondary to underlying psychiatric and medical
conditions, and these should be evaluated and treated as a first measure.
Nonpharmacological interventions for insomnia including sleep hygiene manoeuvres
and exercise are recommended, although the success of these interventions has not
been well documented. Benzodiazepines have been the pharmacologic agents of
choice for the treatment of insomnia, but there is reason to exercise caution
with their use; their overall benefit compared with placebo appears to be minor,
and they are often associated with adverse cognitive effects. Unfortunately, no
other class of drugs has proven to be superior to the benzodiazepines in terms of
benefit:risk ratio. Given the importance of sleep for health and normal daily
functioning the diagnosis, prognosis and treatment of insomnia should be a
research priority.
PMID- 10674060
TI - Chasing the dragon--neurological toxicity associated with inhalation of heroin
vapour: case report.
PMID- 10674061
TI - A view inside the womb.
PMID- 10674059
TI - Meta-analysis of benzodiazepine use in the treatment of insomnia.
AB - OBJECTIVE: To systematically review the benefits and risks associated with the
use of benzodiazepines to treat insomnia in adults. DATA SOURCES: MEDLINE and the
Cochrane Controlled Trials Registry were searched for English-language articles
published from 1966 to December 1998 that described randomized controlled trials
of benzodiazepines for the treatment of insomnia. Key words included
"benzodiazepines" (exploded), "randomized controlled trial" and "insomnia."
Bibliographies of relevant articles were reviewed for additional studies and
manufacturers of benzodiazepines were asked to submit additional randomized
controlled trial reports not in the literature. STUDY SELECTION: Articles were
considered for the meta-analysis if they were randomized controlled trials
involving patients with insomnia and compared a benzodiazepine with placebo or
another active agent. Of the 89 trials originally identified, 45 met our
criteria, representing a total of 2672 patients. DATA EXTRACTION: Data were
extracted regarding the participants, the setting, details of the intervention,
the outcomes (including adverse effects) and the methodologic quality of the
studies. DATA SYNTHESIS: The meta-analyses of sleep records indicated that, when
compared with placebo, benzodiazepines decreased sleep latency by 4.2 minutes
(non-significant; 95% confidence interval (CI -0.7 to 9.2) and significantly
increased total sleep duration by 61.8 minutes (95% CI 37.4 to 86.2). Patient
reported outcomes were more optimistic for sleep latency; those randomized to
benzodiazepine treatment estimated a sleep latency decrease of 14.3 minutes (95%
CI 10.6 to 18.0). Although more patients receiving benzodiazepine treatment
reported adverse effects, especially daytime drowsiness and dizziness or light
headedness (common odds ratio 1.8, 95% CI 1.4 to 2.4), dropout rates for the
benzodiazepine and placebo groups were similar. Cognitive function decline
including memory impairment was reported in several of the studies. Zopiclone was
not found to be superior to benzodiazepines on any of the outcome measures
examined. INTERPRETATION: The use of benzodiazepines in the treatment of insomnia
is associated with an increase in sleep duration, but this is countered by a
number of adverse effects. Additional studies evaluating the efficacy of
nonpharmacological interventions would be valuable.
PMID- 10674062
TI - Mechanical ventilation: what's new when your patient is blue?
PMID- 10674063
TI - Can Quebec afford dialysis for every 80-year-old patient?
PMID- 10674064
TI - London MDs provide window to surgery's future.
PMID- 10674065
TI - Reform party rejects physician's reforms.
PMID- 10674066
TI - Are Canadians aware of the risks of smoking?
PMID- 10674067
TI - Population rises dramatically but number of med-school applicants remains
stagnant.
PMID- 10674068
TI - Mycobacterium ulcerans disease; Buruli ulcer.
PMID- 10674069
TI - Manson Lecture. Meningococcal meningitis in Africa.
AB - This review covers the history of meningococcal meningitis in Africa since
epidemics of the infection were first described around 100 years ago. It is
possible that an epidemic strain of the meningococcus was introduced into West
Africa from the Sudan by pilgrims returning from the Haj around the turn of the
century. Since 1905 major epidemics of meningococcal meningitis have occurred in
countries of the Sahel and sub-Sahel every few years, culminating in a massive
epidemic in which nearly 200,000 cases were reported in 1996. Attempts to control
epidemic meningococcal meningitis in Africa by vaccination with meningococcal
polysaccharide vaccines have met with only modest success because epidemics can
progress with great rapidity and vaccination is often started too late. This
situation should be improved as a result of a recent initiative, the
International Coordinating Group (ICG), which is contributing to better
surveillance in countries at risk and ensuring that vaccine is available when
needed. However, in the medium term, the best prospect for the control of
meningococcal meningitis in Africa lies in the recent development of
polysaccharide-protein conjugate vaccines which, unlike polysaccharide vaccines,
are immunogenic in the very young, induce immunological memory and are likely to
give long-lasting protection.
PMID- 10674070
TI - The work of the Tropical Health and Education Trust (THET) in training for
healthcare. Introduction.
PMID- 10674071
TI - Delivering care for diabetes in Ethiopia.
PMID- 10674072
TI - The Nottingham City Hospital-Jimma Institute of Health Sciences link.
PMID- 10674073
TI - Training trainers to improve laboratory services.
PMID- 10674074
TI - The development of professional and postgraduate education through collaborative
links with Kumasi, Ghana.
PMID- 10674075
TI - Emergency life-saving surgical courses in Africa.
PMID- 10674076
TI - Seasonal and nocturnal domiciliary human landing/biting behaviour of Lutzomyia
(Lutzomyia) evansi and Lutzomyia (Psychodopygus) panamensis (Diptera;
Psychodidae) in a periurban area of a city on the Caribbean coast of eastern
Venezuela (Barcelona; Anzoategui State).
AB - In recent years, in addition to American cutaneous leishmaniasis (ACL), a
significant number of cases of American visceral leishmaniasis (AVL) have been
reported in periurban areas of Barcelona city (Anzoategui State, Venezuela). We
studied the bionomics of Lutzomyia (Lutzomyia) evansi and Lutzomyia
(Psychodopygus) panamensis, possible vectors of AVL and ACL, respectively, in El
Rincon, a periurban village of that city. To evaluate the seasonal domiciliary
landing/biting activity of sandflies on human bait, a house was chosen in El
Rincon. Landing catches were carried out between 18:00 and 06:00, once a month
for a year. The results show the presence of 2 species, Lu. (Lu.) evansi (89.9%)
and Lu. (Psy.) panamensis (10.1%). Lu. evansi was most abundant in the months of
October and July, associated with the bimodal cycle of annual rainfall in the
area. Maximum landing/biting activity of Lu. evansi was observed at 24:00 and
03:00. These findings suggest that at this time of the year and at these hours
there is heightened risk of the transmission of AVL. Lu. panamensis monthly
abundance also shows a direct association with rainfall and maximum
landing/biting activity was observed between 02:00 and 03:00. The lower
domiciliary abundance of Lu. panamensis suggests its greater importance in the
extradomiciliary transmission of ACL.
PMID- 10674077
TI - Similar blackfly attraction by onchocerciasis patients and individuals putatively
immune to Onchocerca volvulus.
AB - In areas endemic for onchocerciasis, a small number of individuals show no
detectable infection with Onchocerca volvulus despite an apparently similar
exposure to the transmitting blackflies. Such individuals have been termed
putatively immune. Since several studies have indicated marked host differences
in attractiveness for blood-seeking insects, putative immunity in O. volvulus
infection may result, at least in part, from low vector attractiveness of the
respective individuals. In an area hyperendemic for onchocerciasis (Guinea),
where Simulium yahense is the predominant vector, we organized fly catches by
putatively immune individuals and individuals with moderate-to-high worm counts.
No differences were found between the 2 groups with respect to (i) the attraction
of blackflies, (ii) the attraction of blackflies infected with O. volvulus, or
(iii) the numbers of O. volvulus larvae carried by the attracted blackflies.
PMID- 10674078
TI - Cryptococcal meningitis in AIDS patients: an emerging opportunistic infection in
Senegal.
PMID- 10674079
TI - Biased distribution of msp1 and msp2 allelic variants in Plasmodium falciparum
populations in Thailand.
AB - Plasmodium falciparum isolates were obtained from Thai patients attending a
malaria clinic on the Thai-Kampuchean border over 4 cross-sectional surveys
carried out at 3-monthly intervals. The genetic structure of the parasite
populations was determined by nested polymerase chain reaction (PCR)
amplification of polymorphic regions of 3 P. falciparum antigen genes: msp1, msp2
and glurp. Although a high degree of diversity characterized these isolates, the
overall population structure of the parasites associated with patent malaria
infections was observed to remain relatively stable over time. The highest degree
of polymorphism was observed with msp2, and the mean number of lines per
infection (multiplicity of infection) calculated with this marker was higher than
that obtained using msp1 or glurp alone, or combined. Infections with > or = 2
parasite lines were seen in 76% of the samples, and were proportionally more
numerous at the start and end of the rainy season. Two interesting exceptions to
the random distribution were observed and involved 2 allelic variants which in
one case were found dissociated (msp1 MAD20-family) and in the other were
associated (msp2 FC27-family). The epidemiological significance of these types of
data is discussed.
PMID- 10674081
TI - Comparative susceptibility of two members of the Anopheles oswaldoi complex, An.
oswaldoi and An. konderi, to infection by Plasmodium vivax.
AB - We compared the susceptibility of Anopheles oswaldoi and An. konderi to infection
by Plasmodium vivax based on the proportion of mosquitoes presenting oocysts and
sporozoites. Anophelines were captured in the State of Acre and Rondonia,
Brazilian Amazon, and used to obtain F1 progenies. After emergence of adults,
male genitalia of mosquitoes of each family were dissected in order to identify
them as either An. oswaldoi or An. konderi. F1 progenies of field-captured An.
oswaldoi, An. konderi and An. darlingi (used as control) were fed simultaneously
on P. vivax-infected blood. Mosquitoes were dissected on day 10-12 after feeding
and examined for the presence of oocysts and sporozoites. Both An. oswaldoi and
An. konderi developed oocysts in the midguts, however, the percentage of oocyst
positive mosquitoes for An. oswaldoi (13.8%) was higher than for An. konderi
(3.3%), and only An. oswaldoi developed salivary infection with sporozoites (6.9%
of positivity). Infection rates in An. darlingi ranged from 22.5% to 30.0% for
both oocysts and sporozoites. These results indicate that An. oswaldoi can
transmit P. vivax and suggest that it is more susceptible than An. konderi.
Although An. oswaldoi is an exophilic and zoophilic species, it may be involved
in malaria transmission as possibly occurred in the State of Acre.
PMID- 10674080
TI - A cohort study of Plasmodium falciparum diversity during the dry season in Ndiop,
a Senegalese village with seasonal, mesoendemic malaria.
AB - Prolonged carriage of Plasmodium falciparum in humans during the dry season is
critical for parasite survival, as the infected subjects constitute a major
reservoir in the absence of transmission. Yet, very little is known about the
host/parasite interactions contributing to parasite persistence. In order to
study the characteristics of P. falciparum infections during the dry season, we
have genotyped parasites collected from untreated, asymptomatic individuals
during 3 cross-sectional surveys conducted during the dry season in Ndiop, a
Senegalese village with seasonal, mesoendemic malaria. Monthly entomological
surveillance did not detect any transmission during that period. Parasite
prevalence decreased markedly in the children aged < 7 years after 7 months of
undetected transmission, but was stable in older children and adults throughout
the dry season. In all chronically infected individuals, infection complexity
remained stable, but there were substantial fluctuations of individual
genotype(s), reflecting complex dynamics of multiple-clone infections during
chronic asymptomatic parasite carriage. This fluctuation resulted in changes in
the msp1 and msp2 allelic distribution within the cohort after 7 months of
undetected transmission, contrasting with the stability observed during the
preceding rainy season in that village.
PMID- 10674082
TI - Is Leishmania infantum zymodeme MON-253 involved in an outbreak among intravenous
drug users?
PMID- 10674083
TI - School-based schistosomiasis control programmes: a comparative study on the
prevalence and intensity of urinary schistosomiasis among Nigerian school-age
children in and out of school.
AB - A cross-sectional study was conducted in February 1998 on the prevalence and
intensity of urinary schistosomiasis among school-age children in and out of
school at Adim village in Nigeria to test the objective of delivering a control
programme through the school system. School enrollment figures and non-attendance
rate were collated from questionnaires that were self-administered by heads of
families. Prevalence and intensity of infection were determined following
filtration of urine and counting of carbol fuchsin-stained eggs of Schistosoma
haematobium. The rates of regular school attendance, irregular attendance and non
attendance were 69.1%, 5.1%, and 25.8%, respectively. These indices were not
significantly associated with the age of the schoolchildren (P > 0.05). Boys
(76.6%) were more associated with regular attendance than girls (61.4%) (P <
0.0001) while girls had a higher rate of non-attendance (32.7%) than males
(19.1%) (P < 0.0001). Although more out-of-school children were infected (90.7%)
than those in school (86.8%), the difference was not statistically significant (P
> 0.05). The same association was established in the variation of mean egg count
between the 2 study populations though intensity was higher among out-of-school
children. The principal reasons proffered for the high rate of non-attendance
listed in their order of importance were: economic, sickness, poor performance,
refusal, farming and fishing. A dual method of control that would in incorporate
the integration of recognized local authorities is suggested in areas with
moderate school attendance rate like Adim, as lack of treatment of infected out
of-school children ensures continuous contamination and re-infection.
PMID- 10674084
TI - Differences in tuberculosis incidence rates in township and in rural populations
in Ntcheu District, Malawi.
AB - There has been a large upsurge of tuberculosis (TB) in many countries in sub
Saharan Africa, mainly as a result of the co-existing human immunodeficiency
virus (HIV) epidemic. Malawi has had a well-run National TB Control Programme
(NTP) with good registration and recording of cases. For some years the NTP has
had the impression that TB in the country is concentrated around townships and is
less prevalent in the rural areas. This impression was investigated in a rural
district (Ntcheu District) in Malawi. Data on new TB cases were collected from
the district TB register for the years 1992-96 and average annual TB incidence
rates per 100,000 for semi-urban and rural populations were calculated for this
period. There was a significantly higher incidence of TB, particularly amongst
cases with smear-negative pulmonary TB and extrapulmonary TB, in the semi-urban
population compared with the rural population. Possible explanations could be
higher HIV seroprevalence rates in semi-urban areas compared with rural areas,
under-diagnosis at health centres or poor access to medical facilities for rural
people.
PMID- 10674085
TI - Evaluation of a standardized leishmanin skin test in Guatemala.
AB - Before recommending the skin-test use at national level in Guatemala of an
antigen prepared from Leishmania major (a Leishmania species not found in the New
World), we conducted a study in 100 Guatemalans to determine its sensitivity and
specificity. The antigen consisted of 0.1 mL of a solution that contained 5 x
10(6) promastigotes of L. major (MRHO/IR/75/VAX). Positive leishmanin skin test
(LST) reactions at 48 h were observed in 16 (80%) of 20 patients with proven
active cutaneous leishmaniasis (CL), 18 (90%) of 20 with previously treated
proven CL, and in 18 (90%) of 20 with a history and compatible scan of previously
suspected but unconfirmed CL. None of 20 healthy controls or 20 patients with
skin lesions due to causes other than CL had positive reactions to the LST,
giving a sensitivity of 85% and specificity of 100%. There were no statistically
significant differences in ethnic group, age, duration of the lesion, lesion size
or Leishmania species between the 34 persons with true positive reactions. Even
though it will be necessary to test this antigen on a larger number of patients,
these preliminary results show that this antigen is specific and reasonably
sensitive in identifying current or past CL and that it is a reasonable choice
for epidemiological studies on CL in Guatemala.
PMID- 10674086
TI - Use of molecular tools for the diagnosis and typing of a Leishmania major strain
isolated from an HIV-infected patient in Burkina Faso.
PMID- 10674087
TI - Increased sensitivity of routine laboratory detection of Strongyloides
stercoralis and hookworm by agar-plate culture.
AB - The efficacy of agar-plate culture has been evaluated for the detection of
Strongyloides stercoralis and hookworm, compared with direct smear, the formalin
ether sedimentation technique and the filter-paper method. Of 1085 stool samples
from the routine laboratory service at King Chulalongkorn Memorial Hospital in
Bangkok, 241 samples harboured S. stercoralis, 153 hookworm and 2 Rhabditis
hominis. The recovery rate of S. stercoralis by agar-plate culture is
significantly superior to the other methods (P < 0.005). The ratios of positive
results from the methods used to the total number of S. stercoralis-positive
cases were as follows: 1:1.03 by agar-plate culture, 1:1.85 by the filter-paper
method, 1:1.98 by the sedimentation technique and 1:10.48 by direct stool smear.
A similar trend of the efficacy ratio of each method was obtained for hookworm
detection. The characteristic furrows left by hookworm larvae, and larvae and
adults of S. stercoralis could be used for preliminary species identification.
Daily search for furrows on agar plates for up to 6 consecutive days resulted in
an increased sensitivity for diagnosis of both S. stercoralis and hookworm
infections.
PMID- 10674088
TI - Detection of antibodies against hepatitis A virus in eluates of blood spotted on
filter-paper: a pilot study in Rio de Janeiro, Brazil.
AB - The validity of blood spotted on to filter-paper (BSOFP) eluates for the
detection of antibodies against hepatitis A virus (HAV) was investigated in 718
individuals (children and adults) during a field study in a small area in Rio de
Janeiro State, Brazil. Serum samples were considered the 'gold standard'. BSOFP
eluates were analyzed by 2 different techniques: microplate competitive enzyme
linked immunosorbent assay (ELISA) of the whole study group and microparticle
enzyme immune assay (MEIA) of a subsample of 59 individuals. For BSOFP eluates by
ELISA, sensitivity and specificity were 89.6% (95% CI: 84.7-93.1) and 97.5% (95%
CI: 95.6-98.7), respectively. For a seroprevalence of anti-HAV antibodies of 32%,
the positive predictive value was 94.5% (95% CI: 90.3-97.0) and the negative
predictive value was 95.2% (95% CI: 92.8-96.8). The test efficiency was 95.0%
(95% CI: 93.1-96.4). Similar results were found for BSOFP eluates by MEIA.
Agreement between the 2 techniques used for BSOFP (ELISA and MEIA) was also high
(kappa = 0.93). These results encourage the more widespread application of BSOFP
as a means of surveillance for large-scale epidemiological studies for hepatitis
A.
PMID- 10674089
TI - The optimum relative centrifugal force and centrifugation time for improved
sensitivity of smear and culture for detection of Mycobacterium tuberculosis from
sputum.
AB - Direct microscopy is the only available method for diagnosis of tuberculosis in
most centres in developing countries. Methods to improve the sensitivity of
direct smear are an urgent requirement. Sputum specimens artificially seeded with
known concentrations of Mycobacterium tuberculosis were liquefied and
decontaminated with sodium hydroxide-sodium citrate-N-actyl-L-cysteine solutions.
They were subjected to different centrifugation forces and centrifugation times
after which the centrifuged deposits were examined by smear and culture.
Statistical analysis of results was carried out using EpiInfo version 6.0. The
optimum relative centrifugal force (RCF) and centrifugation time combination was
4000 g for 15 min. The sensitivity of detection at an RCF of 4000 g for 15 min
was 5000 organisms/mL and 500 organisms/mL for smear and culture, respectively.
When results of 163 clinical samples were analyzed after centrifugation at 4000 g
for 15 min sensitivity of the direct smear improved from 63% to 92% (P < 0.05)
and negative predictive value from 30.5% to 45% (P < 0.05) when culture was
considered the 'gold standard'. With the concentrated smear there was a reduction
in specificity from 82% to 60% (P > 0.05). As most laboratories are equipped with
a simple centrifuge, smear sensitivity can be improved with this simple
modification. The other advantage is that the same centrifuged deposit can be
cultured, in contrast to when sodium hypochlorite is used for liquefaction.
PMID- 10674090
TI - Does the use of urinary reagent strip tests improve the bedside diagnosis of
meningitis?
PMID- 10674091
TI - Blood in the urine of adolescent girls in an area of Ghana with a low prevalence
of infection with Schistosoma haematobium.
PMID- 10674092
TI - Acute attacks in the extremities of persons living in an area endemic for
bancroftian filariasis: differentiation of two syndromes.
AB - The natural history of lymphatic disease in human filariasis remains unclear, but
recurrent episodes of acute lymphangitis are believed to constitute a major risk
factor for the development of chronic lymphoedema and elephantiasis. Prospective
analysis of 600 patients referred to the filariasis clinic of the Centro de
Pesquisas Aggeu Magalhaes/FIOCRUZ in Recife, Brazil, indicated that 2 distinct
acute syndromes accompanied by lymphangitis occur in residents of this filariasis
endemic area. One syndrome, which we call acute filarial lymphangitis (AFL), is
caused by the death of adult worms. It is relatively uncommon in untreated
persons, usually is asymptomatic or has a mild clinical course, and rarely causes
residual lymphoedema. The second syndrome, of acute dermatolymphangioadenitis
(ADLA), is not caused by filarial worms per se, but probably results from
secondary bacterial infections. ADLA is a common cause of chronic lymphoedema and
elephantiasis in Recife as well as in other areas of Brazil where lymphatic
filariasis is not present. The syndromes of AFL and ADLA can be readily
distinguished from each other by simple clinical criteria.
PMID- 10674093
TI - Fatal primary dengue infections in Brazil.
PMID- 10674094
TI - Haematological characteristics and HIV status of pregnant women in Abidjan, Cote
d'Ivoire, 1995-96.
AB - To describe the haematological profile of pregnant women and to compare these
characteristics according to HIV serostatus in Abidjan, Cote d'Ivoire, a cross
sectional study was made in the context of a research intervention programme to
reduce mother-to-child transmission (MTCT) of HIV (ANRS 049 trial). HIV testing
was systematically proposed to pregnant women attending the mother and child
health clinic of a community health centre. Blood samples were tested for HIV
antibodies using Genelavia and Peptilav. The haematological parameters were
measured with a Coulter counter. From May 1995 to March 1996, 1646 pregnant women
accepted HIV testing and had a full blood count available. The prevalence of HIV
infection was 12.0% (n = 197). The prevalence of anaemia (haemoglobin [Hb] < 11
g/dL) was 70.1%, n = 1155 (95% confidence interval 68-72%) and significantly
higher in HIV+ (81.7%, n = 161) than in HIV- women (68.9%, n = 994) (P < 0.001).
Severe anaemia (Hb < 7 g/dL) was present in 1.9% of the women (n = 31), 4.6% (n =
9) in HIV+ and 1.5% (n = 22) in HIV- women (P < 0.001). HIV infection,
primigravidae and secundigravidae were factors independently associated with
anaemia. Anaemia was highly prevalent in this population while severe anaemia was
rare. HIV infection was a contributor to anaemia in pregnancy. As zidovudine,
with its known haematological toxicity, has recently been introduced to prevent
MTCT of HIV in developing countries, screening HIV+ women for severe anaemia is
necessary.
PMID- 10674095
TI - Maternal iron status and intrauterine growth retardation.
AB - The objective of this study was to compare the iron status of 356 mother-baby
pairs who had intrauterine growth retardation (IUGR) with 356 mother-baby pairs
who had appropriate weight for gestational age (AGA). Mothers were selected in
1991/92 from 4 hospitals in Campinas city, Brazil, where 95% of deliveries take
place. Gestational age of the newborns was determined by the Capurro method.
Newborns were classified as having IUGR according to the Lubchenco birthweight
for gestational age standard. Haemoglobin (Hb), haematocrit (Ht) and ferritin
were determined, respectively, by the cyanmethaemoglobin method, an haematocrit
centrifuge, and an immunoenzymetric assay. Mean levels of Hb and Ht were higher
in IUGR (16.4 g/dL; 51.7%) than in AGA babies (15.7 g/dL; 49.7%) (P < 0.001), as
a consequence of intrauterine hypoxia. Higher maternal levels of ferritin (> 50
micrograms/L) were more common in IUGR than in AGA mothers (P < 0.001). Forty
seven percent (335/712) of the IUGR and AGA mothers were anaemic (Hb < or = 11.0
g/dL), but only 4.4% (31/356) of them had low levels of ferritin (< or = 10
micrograms/L). We advise further large epidemiological studies involving IUGR and
AGA mother-baby pairs, elucidating the mechanisms underlying the plasma-volume
changes in pregnancy, and the prevalence of iron-deficiency anaemia assessed by
different indicators, in view of the fact that ferritin can be affected by
inflammation and infection, important risk factors for IUGR in developing
countries.
PMID- 10674096
TI - Alopecia induced by ants.
PMID- 10674097
TI - The effect of artesunate combined with standard antimalarials against chloroquine
sensitive and chloroquine-resistant strains of Plasmodium falciparum in vitro.
AB - The interactions of artesunate with chloroquine, mefloquine, quinine, doxycycline
and pyrimethamine were tested in vitro against chloroquine-sensitive (D10) and
chloroquine-resistant (RSA11) strains of Plasmodium falciparum. Mefloquine and
quinine both showed synergism of artesunate activity against each of the strains,
whilst doxycycline showed an additive interaction. Pyrimethamine combinations
were antagonistic, and the combination of artesunate with chloroquine was
antagonistic against RSA11, and additive against D10. Although weak antagonism in
vitro might not indicate any clinical significance, synergism with artesunate may
increase the clinical usefulness of either drug, and could potentially be of
value in delaying the emergence of resistance.
PMID- 10674098
TI - Treatment of vivax malaria on the western border of Thailand.
AB - The efficacy of chloroquine (25 mg base/kg over 3 days) in Plasmodium vivax
malaria was evaluated in 1995/96 in 342 patients living in an endemic area on the
western border of Thailand. Clearance of fever and parasites was obtained within
2 days in > 95% of the patients, and all were aparasitaemic by day 4.
Reappearance of P. vivax occurred in 1 patient on day 21 and in 8 by day 28,
giving a 28-day cure rate of 97% [95% confidence interval (CI) 95-99%]. By day
63, the relapse/re-infection rate was 63% (95% CI 57-69%). Most reappearances of
parasitaemia (85%; 121/143) were symptomatic. These patients were retreated
either with chloroquine alone (n = 70) or with chloroquine and primaquine (0.25
mg/kg daily for 14 days) (n = 43). Only 1 patient (in the chloroquine-only group)
had prolonged parasite clearance (D8) and he developed recurrent P. vivax by day
21 suggesting possible recrudescence. The addition of primaquine to chloroquine
reduced the risk of having a third vivax episode within 2 months by 96% (95% CI
83-99%). This resulted in a significantly higher haematocrit at day 42 despite a
greater decrease in haematocrit during the first week of treatment with
chloroquine-primaquine (P = 0.04). Chloroquine remains highly effective on the
western border of Thailand and the use of strictly supervised primaquine
effectively prevents relapse. The introduction of primaquine on a large scale in
an endemic area still requires a long-term risk-benefit assessment which must
take into account potential toxicity, low compliance and reductions in the
incidence and severity of P. falciparum infections by co-existent P. vivax.
PMID- 10674099
TI - Risk factors for treatment failure after melarsoprol for Trypanosoma brucei
gambiense trypanosomiasis in Uganda.
AB - We evaluated the treatment failure rate among late-stage human African
trypanosomiasis (HAT) patients treated with melarsoprol in Arua, northern Uganda,
between September 1995 and August 1996, and identified the risk factors for
treatment failure. We conducted a retrospective cohort study in October 1998, and
performed a survival analysis. A treatment failure was defined as a late-stage
HAT patient fully treated with melarsoprol and classified as an HAT case at any
follow-up visit within 2 years after treatment. Among 428 patients treated in the
study period, 130 (30.4%) were identified as treatment failure within 2 years
after discharge. The multivariate analysis showed that patients who experienced
treatment failure after melarsoprol were more likely to have been admitted as a
relapsing case (relative hazard, RH = 11.15 [6.34-19.61]), and to have been
diagnosed with trypanosomes in the lymph nodes (RH = 3.19 [2.10-4.83]) or in the
cerebrospinal fluid (CSF) (RH = 1.66 [1.09-2.53]). The risk of treatment failure
also increased with the number of cells in the CSF. The treatment failure rate
after melarsoprol observed in Arua is greatly above the expected figures of 3-9%.
More research is needed to confirm whether it is related to the variation of
melarsoprol pharmacokinetics between individuals, or if it is associated with a
reduced susceptibility of the trypanosomes to melarsoprol. The study emphasizes
the need for second-line drugs to treat patients that have already received one
or several full course(s) of melarsoprol.
PMID- 10674100
TI - Treatment outcome of patients with smear-negative and smear-positive pulmonary
tuberculosis in the National Tuberculosis Control Programme, Malawi.
AB - National tuberculosis control programmes (NTPs) in sub-Saharan Africa do not
routinely record or report treatment outcome data on smear-negative pulmonary
tuberculosis (PTB) patients. Twelve-month treatment outcome on patients with
smear-negative PTB registered in all district and mission hospitals in Malawi
during the year 1995 was collected, and was compared with 8-month treatment
outcome in smear-positive PTB patients registered during the same period. Of 4240
patients with smear-negative PTB, 35% completed treatment, 25% died, 9% defaulted
and 7% were transferred to another district with no treatment outcome results
available. In 24% of patients treatment cards were lost and treatment outcome was
unknown. These results were significantly inferior to those obtained in 4003
patients with smear-positive PTB in whom 72% completed treatment, 20% died, 4%
defaulted, 2% were transferred and 1% had positive smears at the end of
treatment. These differences between patients with smear-negative and smear
positive PTB were similar when analysed by sex and by most age-groups. Higher
mortality rates in patients with smear-negative PTB are probably attributable to
advanced HIV-related immunosuppression, and higher default and treatment unknown
rates probably reflect the lack of attention paid by TB programme staff to this
group of patients. As a result of this country-wide study the Malawi NTP has
started to record routinely the treatment outcomes of smear-negative TB patients
and has set treatment completion targets of 50% or higher for this group of
patients.
PMID- 10674101
TI - A preliminary study of neopterin as a potential marker for severe dengue virus
infection.
PMID- 10674102
TI - [Periodically leaking capillaries].
AB - The systemic capillary leak syndrome (Clarkson's syndrome) is a rare idiopathic
disorder, characterized by recurrent episodes of hypovolaemic shock,
haemoconcentration and hypoalbuminaemia due to a sudden shift of fluid and
macromolecules from the intravascular to the interstitial space. A young man is
presented in whom recurrent attacks of hypotension and diffuse swelling were
initially attributed to staphylococcal toxic shock syndrome. With the additional
finding of a monoclonal gammopathy, the diagnosis of systemic capillary leak
syndrome was made. Recognition of this syndrome is important, as prophylactic
treatment with terbutaline and theophylline may be beneficial in this life
threatening syndrome.
PMID- 10674103
TI - [Virtual colonoscopy].
AB - Virtual colonoscopy is a fundamentally new imaging technique, in which volumetric
CT or MRI data are processed to virtual endoscopic images of the colon. The main
application is early detection of colorectal cancer. To date, no data of studies
on screening for colorectal cancer are available. The results of clinical studies
show comparable results for endoscopy and virtual colonoscopy for the detection
of clinically relevant polyps (> or = 1 cm) and better results of virtual
colonoscopy than of conventional barium studies. Whether virtual colonoscopy as a
minimally invasive technique will gain a place in screening for colorectal cancer
depends on several issues such as costs, effectiveness and acceptance by
patients.
PMID- 10674104
TI - [Immunology in medical practice. XXVII. Vaccines against malaria: new
perspectives].
AB - Malaria belongs to the five most important infections in the world and is
responsible for 2-3 million deaths each year. A universally active vaccine
against Plasmodium falciparum is not available to this day. However, the
feasibility of a vaccine is underlined by the results of experimental studies in
animal models as well as by the fact that immunity is acquired in humans after a
number of infections. Vaccine development is hampered by the complex life cycle
of the parasite as well as by the lack of knowledge about the key molecules
involved in the cycle. Moreover the parasite shows an extraordinary capacity to
evade the immune response. Over the last decade understanding of the immune
response has improved; moreover, a number of Plasmodium derived proteins are in
the process or on their way to clinical testing as a vaccine. The most recent
activities focus on the delineation of the P. falciparum genome as well as on
different strategies for vaccination.
PMID- 10674105
TI - [Diagnosis and treatment of cholelithiasis].
AB - Most patients with gallbladder stones are asymptomatic and do not require
treatment. Biliary colics are the main indication for laparoscopic
cholecystectomy: the treatment of choice for gallbladder stones. Dyspepsia is not
an indication for treatment of gallstones. The indications for bile salt therapy
and extracorporeal lithotripsy are limited. Acute cholecystitis should be treated
with cholecystectomy a chaud whereas longstanding cholecystitis is preferably
treated with cholecystectomy a froid. Bile duct stones are mainly treated
endoscopically during endoscopic retrograde cholangiopancreatography (ERCP):
pancreatitis, bleeding and perforation are the main complications. Prior to
cholecystectomy, an ERCP is indicated in case of cholangitis, severe
pancreatitis, persisting jaundice, bile duct stones on ultrasonography, or the
combination of dilated ducts and abnormal liver function tests. After endoscopic
stone removal, a cholecystectomy is indicated for patients < 50 years but a 'wait
and see' policy is justified in elderly patients.
PMID- 10674106
TI - [Cervical smears taken by physicians' assistants are of lesser quality than
smears taken by family physicians, but almost as good as the national average].
AB - OBJECTIVE: To compare the quality of cervical smears taken by practice assistants
with the quality of smears taken by general practitioners. DESIGN: Retrospective.
METHODS: Data were collected on the 1672 smears taken as part of the population
screening for cervical cancer and recorded 13 general practices in Limburg in the
year 1997. The results of smears taken by practice assistants were compared with
those made by general practitioners with regard to the quality indicators
'presence of endocervical cells' and 'absence of Pap-o'. RESULTS: In 12.3% of the
481 cervical smears taken by the 17 practice assistants endocervical cells were
absent. This is statistically significantly more than to the results (7.2%) in
1191 smears taken by the 22 general practitioners (relative risk: 1.70: 95%
confidence interval: 1.23-2.70). Similar differences, but not statistically
significant, were found with regard to Pap-o results and pathological findings.
Most of the practice assistants had 1-2 years' experience. The proportion of
smears made by practice assistants in which endocervical cells were lacking was
reasonable compared with the average of 10% for the Netherlands as a whole.
CONCLUSION: The cervical smears taken by practice assistants were of lower
quality than those taken by the general practitioners but almost as good as the
nationwide mean.
PMID- 10674107
TI - [Regional differences in prehospital time delay for patients with acute
myocardial infarction; Rotterdam and Groningen, 1990-1995].
AB - OBJECTIVE: To describe pre-hospital delay times in patients with acute myocardial
infarction (AMI) in two regions in the Netherlands: Groningen (a region with high
mortality for coronary heart disease (CHD)) and Rotterdam (a region with low CHD
mortality). DESIGN: Descriptive. METHOD: The pre-hospital treatment delay of AMI
patients in Rotterdam in 1990-1991 versus 1993-1995 was compared and also
compared between Groningen en Rotterdam (1993-1995). In each region 3 hospitals
participated (1 academic, 2 regional). The data were collected with a structured
interview within 7 days after onset of symptoms in hospitalized AMI patients (n =
924) or by interviewing relatives of deceased patients (n = 40). The median
patient, general practitioner (GP) and ambulance delays were calculated. RESULTS:
Total median pre-hospital delay was 2.5 hours (5-95-percentile: 50 min-36 hours).
Median patient delay time was shorter in Groningen than in Rotterdam
(respectively 30 and 45 min) and the same applied to doctor delay times
(respectively 38 and 72 min). In Rotterdam doctor delay time decreased by 23 min
between 1990-1991 and 1993-1995. Median ambulance delay was 30 min in Rotterdam
and 35 min in Groningen. Total pre-hospital delay times of self referred patients
were 32-78 min shorter than those of patients who consulted a GP before
admission. CONCLUSION: Reduction of pre-hospital delay in Rotterdam between 1990
1991 and 1993-1995 was due to faster decision time by the GP. The short pre
hospital treatment delay in Groningen in hospitalized patients suggests that
relatively more AMI patients die outside hospital which may contribute to the
high CHD mortality in this region.
PMID- 10674108
TI - [Increase of malaria among migrants in Amsterdam-Zuidoost].
AB - In a general practice in Amsterdam Southeast in 1998 a delayed first attack of
Plasmodium ovale infection was diagnosed in a 13-year-old girl from Ghana,
malaria tropica with a low parasitaemia index in a 43-year-old Ghanaian man and a
8-year-old Ghanaian girl, and Plasmodium vivax infection in a 44-year-old Surinam
woman. The Ghanaian patients had visited their native country, the Surinam woman
had contracted the infection during a visit to India. All patients responded well
to antimalaria medication. These patients were among a total of 6 patients of non
Dutch origin diagnosed with malaria in 1998 in this general practice. Four
patients had not taken any prophylactic drug and two had not used the drugs
properly. A relative increase of malaria in immigrants has been seen in the
Netherlands and elsewhere in Europe in recent years. Underestimation of the risks
and lack of knowledge of malaria and of the changing epidemiology make people of
ethnic minorities travel without taking appropriate precautions. New, creative
ways of communication and information will have to be explored to reach these
migrant communities.
PMID- 10674109
TI - [Cervical smears unsuitable for exclusion of cervical carcinoma].
AB - In women with contact bleeding or vaginal discharge, cervical smears are often
made to exclude the possibility of cervical carcinoma. During the past ten years,
several women sued pathologists for failure to diagnose cervical cancer because
of false-negative results entailing a diagnostic delay of years. This, however,
is unjustifiable: clinicians have to consider the aim of performing a test and
always have to interpret the outcome within the clinical context. If the
indication for testing is to exclude cervical cancer with enough certainty, a
false-negative rate possibly as high as 45% makes the smear definitely unsuitable
for this aim.
PMID- 10674110
TI - [Female circumcision: histories of 3 patients].
PMID- 10674111
TI - [Incidence and risk factors for eye injuries sustained at fairs: metal particles
in the eye after a ride of dodgem cars].
PMID- 10674112
TI - [Physical diagnosis--paradoxical pulse].
PMID- 10674113
TI - [Missed infections in immigrant children and the medical care for underage
refugees].
PMID- 10674114
TI - [Unusual form of ileus, except in elderly patients?].
AB - Two women aged 88 and 92, recently admitted to hospital, were diagnosed with
gallstone ileus. Over a longer period of time they had suffered intermittently
from abdominal pain related to a migrating and impacting stone. This disease is
mostly diagnosed correctly during exploratory laparotomy for persistent
intestinal obstruction. CT scanning, however, is a new and helpful way to early
diagnosis. Both women had successful surgery. Gallstone ileus is a disease of the
elderly; its early diagnosis is important. CT can be very helpful in this
respect.
PMID- 10674115
TI - [Dutch research on the effectiveness of medical prescription of heroin;
background, research design and preliminary results].
AB - In the Netherlands the total number of heroin addicts amounts to approximately
25,000. Of these about 70% is in contact with the treatment system. The remaining
30% have not been seeking help, believes that no help is needed or has lost faith
in a better future altogether. Of those who are in treatment, 30% attempt to stop
the use of opiates through participation in drug free abstinence oriented
outpatient or inpatient treatment programs. The remaining 70% have given up the
outlook of a drug free existence at least temporarily, and they participate in a
methadone maintenance program directed at stabilizing drug use, harm minimization
and social integration. In two-thirds these goals are not or only partially
achieved. For these patients additional treatment options are needed. Medical
prescription of heroin is such an option. However, currently no data are
available on the effectiveness of this option. The Dutch study on the
effectiveness of medical prescription of heroin is an attempt to obtain these
data. In the study, simultaneously two randomized trials are being executed: one
with inhalable and one with injectable heroin. In these trials, 625 (375 inhalers
and 250 injectors) chronic treatment-resistant heroin addicts who are currently
enrolled in a methadone maintenance program are offered heroin (in combination
with oral methadone) seven days per week, three times per day for a period of six
to twelve months. It is a multi-center study with eight treatment units in six
cities in the Netherlands (Amsterdam, The Hague, Groningen, Heerlen, Rotterdam,
Utrecht). At this moment 180 patients have been randomized. During the treatment
no medical complications have been observed and no serious public order or safety
problems have occurred. Study participants have been very compliant both with the
treatment regimen and the research requirements. The latter is indicated by the
fact that 85% of all the two-monthly assessments have been completed.
PMID- 10674116
TI - [Therapeutic angiogenesis through intramuscular injection of the gene for
vascular endothelial growth factor (VEGF)].
AB - Therapeutic angiogenesis by injection of growth factors or genes encoding for
these appears a promising strategy for treatment of critical limb ischaemia but
is currently still in an experimental phase. Among the cytokines that promote
angiogenesis, i.e. the postnatal growth of blood vessels due to activation and
proliferation of endothelial cells, vascular endothelial growth factor (VEGF)
takes a special position. VEGF has proven to be a powerful angiogenic factor in
vivo that specifically promotes migration and replication of endothelial cells.
The specificity of VEGF for endothelial cells, compared with the more widespread
effects of other factors such as fibroblast growth factor (FGF), may provide a
broader therapeutic potential. The recombinant form of the human VEGF gene can be
injected intramuscularly as a plasmid (phVEGF). The angiogenic effect of phVEGF
can be explained in several ways: by direct stimulation of proliferation and
migration of endothelial cells in vivo; by recruitment of previously existing
collaterals; and by improving vasomotor function of vessels in ischaemic tissue.
PMID- 10674117
TI - [Non-oral routes of administration of psychotropic agents].
AB - For patients not able to take oral medication, a psychotropic agent may be
selected not only according to its therapeutic and side effects but also to the
optional alternative routes of administration. Partly because of the various
options of routes of administration haloperidol is the first choice 'classic'
antipsychotic medication. As to 'atypical' antipsychotics, the preparation of an
ill-tasting clozapine liquid is possible. Lorazepam, clorazepate and diazepam
injections (oil in water emulsion) or diazepam per rectiole are non-oral
anxiolytics of first choice. Clomipramine and amitriptyline are the only
parenteral antidepressants available in the Netherlands. Lithium tablets without
controlled release may be administered as a suspension via a catheter.
Carbamazepine or valproate may serve as a parenteral alternative for lithium. In
case of extrapyramidal side effects of antipsychotics, biperiden or promethazine
may be administered parenterally.
PMID- 10674118
TI - [Poor prognosis of osteosarcoma of pelvis; 39 years of registration by the
Netherlands Commission on Bone Tumors].
AB - OBJECTIVE: To evaluate the results of treatment in patients with osteosarcoma of
the pelvis. DESIGN: Retrospective. PATIENTS AND METHODS: Sixty-five patients with
pelvic osteosarcoma registered in the files of the Netherlands Committee on Bone
Tumours over 1957-1995 were reviewed. Complete information was obtained on 62
cases: 27 males and 35 females, median age was 31 years (range: 12-83). Distant
metastases were present in 11 patients (stage IIIB; 18%), while 50 patients had
stage IIB osteosarcoma (81%) and 1 patient stage IB osteosarcoma (2%). The
results of treatment and survival were determined. RESULTS: Median survival was
14 months (2-177), the 5-year survival 15%. Distant metastases developed in 27 of
42 (64%) patients with curatively treated stage IIB osteosarcoma, with prolonged
metastasis-free survival after chemotherapy treatment (p < 0.0012). Survival in
patients with stage IIB pelvic osteosarcoma was better after surgical resection
of the primary tumour than after no operation (p < 0.0054); (neo)adjuvant
chemotherapy gave no longer survival than surgery alone (p < 0.083). CONCLUSION:
The prognosis of pelvic osteosarcoma was poor, despite modern multimodality
treatment regimens, including surgical resection and chemotherapy.
PMID- 10674119
TI - [Genetic screening for familial hypercholesterolemia in 1992-1997: primarily
younger patients in the care of family physicians].
AB - OBJECTIVE: To estimate the proportion of patients with familial
hypercholesterolaemia (FH) who were identified with hypercholesterolaemia in
general practice prior to screening by means of pedigree research and DNA
analysis by the National Foundation for the Identification of Familial
Hypercholesterolemia (StOEH). DESIGN: Retrospective. METHOD: General practice
files of FH patients, diagnosed through genetic screening by the StOEH in 1992
1997 whose general practitioner's (GP's) practice in Amsterdam, Haarlem or
Alkmaar, were studied for cholesterol and FH related information documented in
the period prior to the screening. RESULTS: Out of the 121 persons selected 80
agreed to the study; one GP refused to co-operate. There was no difference
between respondents and non respondents with regard to age, sex or domicile of
the GP. In 48 of 79 (61%) general practice files studied, cholesterol
measurements were reported prior to screening; 39 patients (49%) had
hypercholesterolaemia and 29 (37%) were being treated with cholesterol lowering
drugs. Mean age of the FH patients who had no record of their cholesterol levels
was 25.1 years (SD: 17.0) at the time of screening, 22 years younger than the
mean age of FH patients who did have cholesterol levels on record prior to
screening (47.1 (SD: 18.4); p < 0.0001). CONCLUSION: Of the FH patients
identified through family based genetic screening especially the younger FH
patients are newly brought to the attention of their GP.
PMID- 10674120
TI - [Gender factors in the selection of training for a medical specialty].
AB - OBJECTIVE: To investigate the choice-making process of male and female doctors
regarding their wishes for a career, and their behaviour in the event of their
trying to obtain a resident's post. DESIGN: Descriptive. METHODS: An inquiry by
telephone was held in 1995 among a group of 600 doctors all graduated from
university in 1993 in the Netherlands. Of the respondents (n = 490; 82%) 57% of
the female and 63% of the male doctors aspired to become a resident in a
hospital. The 293 respondents who wanted to obtain a resident's post were asked
for the factors that influenced their choices and to what extent they did. The
scores ranked from 1 ('very positively') to 5 ('very negatively'). RESULTS:
Within 2 years after graduating from university 26% worked as a resident. In
their choice for a specialty male doctors were positively influenced by
technology (mean score: 2.9 versus 2.5), status and income (5.9 versus 5.6) and
scientific activities (2.4 versus 2.1). Women were more influenced by intensive
contact with patients (2.0 versus 1.7), favourable working hours and relatively
few shifts (10.9 versus 10.3). Of the women 43% wanted to work part time, as
against 14% of the men. While the men preferred an informal approach in looking
for a post (38%; formal approach: 29%), women were evenly divided: informal
approach 36%, formal approach 36%.
PMID- 10674121
TI - [Travel experiences in Central- and Eastern Europe: Bosnia--the land behind the
mirror].
AB - Bosnia-Herzegovina is an artificial state created after four years of gruesome
war; it is composed of two countries intertwined like the pieces of a jigsaw
puzzle. An uneasy truce binds the two halves, the Republika Srpska and the Muslim
Croat Federation of Bosnia-Herzegovina together. Under the conditions of the
Dayton accord these two have to collaborate and unify their administrative
systems under the watching eye of the European Union (EU) and thousands of
heavily armed soldiers and policemen. One of these EU-sponsored programmes is the
unification of systems of acquisition, registration and distribution of
medicines, delegated to the EU reconstruction programme PHARE. Whereas the
Serbian half used to buy its drugs from Belgrade, the Muslim-Croatian half was
almost fully dependent on international aid. Though some of the local experts
have been very helpful, both systems are riddled by corruption and inefficiency
and a successful outcome will be little short of a miracle.
PMID- 10674122
TI - [Unobserved death of an infant: cot death?].
PMID- 10674123
TI - [Unobserved death of an infant: cot death?].
PMID- 10674124
TI - [Unobserved death of an infant: cot death?].
PMID- 10674125
TI - [Public health care after the Bijlmermeer airplane crash; the aftermath].
PMID- 10674126
TI - [Public health care after the Bijlmermeer airplane crash; the aftermath].
PMID- 10674127
TI - Critical reflections on the evolution in vascular surgery.
PMID- 10674128
TI - Behcet's disease. An insight from a vascular surgeon's point of view.
AB - Behcet's syndrome is a multisystem inflammatory disease with unknown aetiology,
vasculitis being its major pathological feature. It runs an undulating course of
exacerbations and remissions with a frequency that usually abates with the
passage of time. Following its first description in the medical literature in
1937, many clinical manifestations, including recurrent ulcerations, eye and
urogenital lesions, pulmonary and vascular involvement with thrombus and aneurysm
formation, arthritis and neurological features were reported. Various studies
undertaken in two Medical Faculties of Istanbul University showed that more than
5000 patients have fulfilled three or more International Behcet's Disease Study
Group Criteria and thus can be diagnosed as Behcet's Disease. A total of 142
cases with pulmonary, 30 cases with arterial (non-pulmonary) and 10 cases with
cardiac involvement were demonstrated since 1978. A group of 174 neuro-Behcet's
Disease patients (cerebral venous and vena caval thrombosis as the cause of
intracranial hypertension, extracranial vertebral artery dissection) was
evaluated. Our collected data showed that surgery with special techniques and in
highly selected cases may be useful if used with adjuvant medical therapy, but
might be fatal or unsuccessful in the majority. No means of aggressive surgical
or interventional therapy has a role in altering the course of the pathology
itself when used alone and thus medical treatment is crucial to suppress the
exacerbations.
PMID- 10674129
TI - Clinical and biological relevance of vein cuff anastomosis.
AB - Since a significant number of patients do not have suitable autologous saphenous
vein for femorodistal bypass, the search for alternative graft material
continues. The most commonly used prosthetic material is Polytetrafluoroethylene,
however because of the poor patency of these grafts in the below knee position, a
variety of techniques have been tried to improve their patency. A series of
studies utilizing venous cuffs at the distal anastomosis have showed improved
patency of PTFE grafts. We have reviewed the biological basis for graft failure
and the literature for possible mechanical explanations.
PMID- 10674130
TI - Laparoscopic management of acute small bowel obstruction.
AB - Laparosopy is now a well established tool in abdominal surgery. More often it is
used in acute abominal situations. We present our experience with laparoscopy and
laparoscopic treatment in patients with acute small bowel obstruction. Although
it is technically challenging, in carefully selected patients laparoscopy and
laparoscopic treatment is feasible and a valid option for treatment.
PMID- 10674131
TI - Early feeding after colorectal surgery. Preliminary results.
AB - Thirty three patients were placed under early oral feeding after elective
colorectal surgery. There were 15 male and 18 female patients, mean age: 52
years. Nasogastric tube was removed as soon as they were widely awake, or on the
morning following the afternoon operations. Oral feeding was resumed 4 hours
later, and the first meal consisted in a slight solid meal. There was no
postoperative mortality or significant morbidity. Liquid and solid oral intakes
were resumed 18 and 24 hours respectively after the operation. Tolerance was
perfect in 22 patients (66%), good (slight complaints) in 16%, and was considered
as fair or bad in the last six cases. Intestinal transit was observed after a
median period of 2 days. Tube insertion rate was 12%. No adverse effect on the
anastomoses was noted. Data from the literature confirm that early feeding is
tolerable and safe after open colorectal surgery. More patients should be
included in this protocol to take benefit of the physiological effects of early
oral feeding.
PMID- 10674132
TI - Sentinel lymph node mapping in the management of high risk malignant melanoma.
AB - In patients with malignant melanoma, the selective biopsy of the first draining
lymph node, so-called the sentinel lymph node, allows to identify, with a low
morbidity, the patients with nodal metastasis that require radical
lymphadenectomy and adjuvant systemic chemotherapy. Herein, we report our initial
experience in sentinel lymph node biopsy in 16 patients with malignant melanoma.
The sentinel lymph node was localised using preoperative lymphoscintigraphy and
injection of dye blue. Intraoperatively, the dissection was guided with a gamma
probe and by the recognition of the blue nodes. In the 16 cases the sentinel
lymph node was localised. In 50% of the cases, multiple sentinel nodes were
demonstrated at lymphoscintigraphy and found during surgery. A limited
postoperative morbidity was observed in three cases. Three patients presented
nodal metastasis and underwent further radical lymphadenectomy. We conclude that
sentinel lymph node mapping is a feasible and reproductive procedure. The
preoperative lymphoscintigraphy is essential to identify multiple sentinel nodes
and guide surgical dissection. The impact of this approach on the overall
survival of patients with high-risk melanoma has still to be demonstrated in
studies with a long follow-up.
PMID- 10674133
TI - Primary neuroendocrine carcinoma of the liver: difficult diagnosis of a rare
neoplasm.
AB - Primary neuroendocrine neoplasms of the liver are extremely rare: about 30 cases
only have been described in the literature. We report the case of a 42-year-old
woman with a ten-year evolution. According to the previously reported cases,
primary neuroendocrine carcinoma of the liver is usually multicentric, often
mimicking liver metastases. The demonstration of the hepatic origin of a
neuroendocrine carcinoma is often arduous. A careful surgical exploration and a
prolonged follow-up are mandatory. The treatment of choice is surgical resection
when possible. For progressive and unresectable disease, hepatic arterial
chemoembolization may be considered. However, the prognosis of liver
neuroendocrine tumours is much more favorable than that of hepatocellular
carcinoma and progression has to be demonstrated before instauration of
potentially harmful therapies.
PMID- 10674134
TI - Mucinous cystadenocarcinoma of the appendix. A rare tumour of the right iliac
fossa.
AB - A case of mucinous cystadenocarcinoma of the appendix is presented. The clinical
feature is a painful syndrome of the right iliac fossa. In our observation, the
diagnosis was not allowed by preoperative imaging. Appendectomy was initially
performed and completed by right hemicolectomy and lymphadenectomy after
histological diagnosis of the appendicular malignant tumour was forwarded. The
prognosis of this tumour is generally excellent providing early diagnosis and
wide enough surgery.
PMID- 10674135
TI - Splenic artery aneurysm rupture.
AB - This is the report of a case with an atherosclerotic splenic artery aneurysm
ruptured into the peritoneal cavity which presented with hypovolaemic shock. The
patient underwent successfully emergency laparotomy and splenectomy. A brief
review of the the literature follows.
PMID- 10674136
TI - Off-pump myocardial revascularization for left main stem disease in a high-risk
patient.
AB - Off-pump complete myocardial revascularization for three-vessel disease is often
limited by the difficulty to approach the obtuse marginal branches. A method of
coronary artery bypass grafting without cardiopulmonary bypass used in a high
risk patient with left main stem and three-vessel disease is described.
PMID- 10674137
TI - Rebound thymic hyperplasia after chemotherapy in a patient treated for pulmonary
metastases.
AB - A 38-year-old patient presented with an anterior mediastinal mass after
chemotherapeutic and surgical treatment for lung metastases from a malignant
histiocytoma. Because of the risk for tumour recurrence the thymic mass was
resected. Thymic hyperplasia was found on pathological examination. In this case
thymic hyperplasia is a rebound phenomenon aflcer chemotherapy. It appears to
atrophy during the administration of chemotherapy and regrow afterwards. Surgical
resection provides the definitive diagnosis and treatment.
PMID- 10674139
TI - Medical treatment of newly diagnosed epilepsy.
AB - The first step in the treatment of epilepsy is the confirmation of the diagnosis.
A correct diagnosis not only includes the epileptic origin of the event, but also
the diagnosis of the seizure type and the epileptic syndrome. The second step is
to try to find the aetiology of the seizures. Some papers have shown that the
prognosis of epilepsy is better if the seizures are treated earlier, but other
papers did not find any difference in the long-term prognosis between patients
treated after the first seizure or after several seizures. Therefore, one of the
most difficult points, after confirmation of the diagnosis, with a first or few
seizures will be to identify the risks of relapse in some patients and to
immediately treat them and to avoid treating the others who will have only one or
rare seizures during their lives without any damage. In most cases, the first
treatment will be the prescription of an antiepileptic drug (AED) in monotherapy.
If the cause is treatable, it will be treated concomitantly. In generalised
epilepsies, especially in idiopathic syndromes, valproate will be the first
choice, most of the classic AEDs may worsen some seizure types in these
syndromes. In partial epilepsies, there are no statistically significant
differences in efficacy between the 4 classic major AEDs (carbamazepine,
phenytoin, phenobarbitone and valproate) in pooled data. The choice of the drug
should be more influenced by considerations of safety profile, dosing frequency,
and costs for equivalent advantages. Accordingly, valproate is a good first
choice in patients in whom the epilepsy syndrome is not clearly defined. Efficacy
of newer AEDs is similar to old AEDs but most are better tolerated. However, some
studies including seizure control, side effects, medical consultation, inpatient,
accidental injuries, and laboratory investigations showed that newer AEDs are
more expensive in newly diagnosed patients, compared to classic major AEDs and
this notion should be taken into account for the prescription.
PMID- 10674140
TI - The spectrum of the new antiepileptic drugs.
AB - Over the last decade, many new drugs have been added to the therapeutic
armamentarium for epilepsy. These drugs differ considerably in their mechanisms
of action and, consequently, in their spectrum of efficacy against various
seizure types. Oxcarbazepine, gabapentin, tiagabine and vigabatrin are especially
useful in the management of partial seizures (with or without secondary
generalization) and, probably, also primarily generalized tonic-clonic seizures,
with vigabatrin being of particular value also in the treatment of infantile
spasms. The spectrum of efficacy of lamotrigine and topiramate is broader than
that of the other drugs and includes, in addition to partial and tonic-clonic
seizures, also drop attacks associated with the Lennox-Gastaut syndrome.
Lamotrigine is also effective against absence seizures, while the activity of
topiramate as a potential anti-absence drug has not been adequately explored.
Oxcarbazepine, vigabatrin and tiagabine may aggravate myoclonic and absence
seizures and, likewise, gabapentin may aggravate myoclonic seizures. Therefore,
the latter drugs should not be used (or used with great caution) in patients with
syndromes associated with these seizure types. Apart from differences in spectrum
of efficacy, side effect profiles also differ considerably from one drug to
another, with the risk of serious adverse effects limiting considerably the use
of felbamate and vigabatrin. When added to preexisting therapy in patients with
refractory epilepsies, the new drugs improve seizure frequency in 15% to 40% of
cases, but only rarely freedom from seizures is achieved. In newly diagnosed
patients, the efficacy of the new drugs is similar to that of older agents, but
further studies are required to confirm the claim that the tolerability of some
of these agents is superior to that of established drugs such as carbamazepine or
valproate. The new antiepileptic drugs represent a useful addition to the
therapeutic armamentarium, but because of limited clinical experience and cost
considerations their firstline use cannot be recommended in most situations.
PMID- 10674141
TI - Pharmacoeconomic evaluation of medical treatment of epilepsy: where do we stand?
AB - Qualitative and quantitative improvements of pharmaco-economic evaluation of
antiepileptic drugs have been realized during the last decade. Assessment of
medical treatments is mainly performed through cost-minimization studies, owing
to similar effectiveness of AED. Studies recently published generally consider
hypothetical cohorts of patients and assess resource utilization and medical
effects on the basis of clinical trials and expert panels, limiting evaluation to
direct costs. But they differ in numerous ways due to: the type of patients and
treatment considered, the time span of evaluation, and cost measurement.
Comparison between studies is therefore tricky but it seems that, when
considering monotherapy treatments, carbamazepine and phenytoin are somewhat
cheaper than valproate while lamotrigine is much more expensive but no more
effective. However, these and other antiepileptic agents appear as close
substitutes when prescribed as adjunctive treatments. Refined tools have been
developed to take into account slight differences exhibited on certain outcomes.
One direction currently under evaluation relates to quality of life, and this
will probably leads to an increasing number of cost-utility studies. Some
advances, regarding information on medical resources consumed and outcomes
associated with alternative drugs, as well as methodological options, are still
needed to fully develop pharmacoeconomic evaluation of antiepileptic treatments.
PMID- 10674138
TI - Animal models of focal epilepsy.
AB - Animal models are important in the study of the development and expression of
focal seizures as well as in the preclinical evaluation of antiepileptic
treatment. Many different models are available, including acute and chronic
models for simple partial seizures and models for complex partial seizures. Work
on models has revealed that the pathophysiology of seizure disorders includes
several neurotransmitter and membrane channel alterations. In addition,
epileptogenesis of focal epilepsy has been shown to involve the selective loss of
neurons and axonal reorganization. Antiepileptic treatment still hinges on three
general themes: modulation of voltage-dependent ion channels involved in spike
propagation and burst generation, enhancement of GABA-mediated inhibition, and
suppression of excitatory amino acidergic activity. Many antiepileptic drugs have
proven efficacy against focal seizures in animal models as well as patients. More
recently developed antiepileptic drugs may prove to be superior in the
alleviation of intractable partial seizures. The three general themes of
antiepileptic drug action still dominate the development of antiepileptic
treatment strategies. Too much emphasis on the classical models of focal epilepsy
may hamper the development of innovative strategies. On the other hand, continued
research on new and existing models may broaden our knowledge of the
pathophysiological processes underlying focal epilepsy, and inspire new avenues
in antiepileptic treatment development.
PMID- 10674143
TI - Epilepsy surgery in Belgium, the experience in Gent.
AB - Between January 1992 and July 1998, 320 patients were presurgically evaluated for
medically refractory epilepsy at the University Hospital of Gent. All patients
underwent a comprehensive presurgical evaluation, including extensive
neurological history and examination, video-EEG monitoring of interictal EEG and
habitual seizures, and optimum magnetic resonance (MR). In a large subgroup of
these patients, a comprehensive neuropsychological examination and interictal
18FDG-PET were performed. Subsequently, a bilateral carotid angiography and
intracarotid amytal procedure (Wada-test) were planned in 49 patients to
establish hemispheric language dominance and bilateral memory function. After
proper selection, 23 patients underwent invasive video-EEG monitoring with
intracranial implantation of parenchymal and/or subdural electrodes to further
document the area of seizure onset. From the initial group of 320 potential
surgical candidates, 75 patients (42 males, 33 females) with mean age of 29 years
(range: 2 months-55 years) and mean duration of uncontrolled seizures of 15 years
(range: 2 weeks-38 years) eventually underwent a surgical procedure. Sixty of 75
patients were on high dose antiepileptic polytherapy. Optimum MR detected
structural abnormalities, confined to a limited brain area, in 71 patients. These
abnormalities were of space-occupying nature in 31 cases; an atrophic lesion was
suspected in 39 patients; a combination of space-occupying and atrophic lesion
was seen in 1 case. Structural abnormalities were most frequently located in the
temporal lobe (n = 53) and the frontal lobe (n = 10). Video-EEG monitoring
documented complex partial seizures in 67 patients with occasional secondary
generalisation in 32. Most patients had complex partial seizures of temporal lobe
as defined by clinical and EEG criteria. Two patients had only simple partial
seizures. Ultimately, an area of seizure onset could be determined in all
patients. Temporal lobectomy with hippocampectomy was the most commonly performed
procedure (n = 42). In 13 patients, complete lesionectomies were performed for
epileptogenic structural lesions in and outside the temporal lobe. In 2 patients,
only partial lesionectomies were possible; in 5 patients, only biopsies in
combination with partial lesionectomies could be performed. Anterior 2/3
callosotomy was performed in 4 patients and hemispherectomy was performed in 2
patients. Postsurgical seizure control, after average follow-up of 50 months
(range: 12-98 months), was excellent in 49 patients who became seizure-free. In
these patients, antiepileptic therapy was tapered 2 years after surgery. Patients
in whom only biopsies or partial lesionectomies were performed have poor seizure
control. Epilepsy surgery is a rewarding therapeutic alternative for patients
with medically refractory epilepsy. Comprehensive presurgical evaluation and
epilepsy surgery provide excellent neurological, neurophysiological,
neuropsychological and imaging research opportunities.
PMID- 10674142
TI - Interictal and ictal video-EEG monitoring.
AB - PURPOSE: The purpose of this paper is to demonstrate the diagnostic efficacy and
therapeutic relevance of video-EEG monitoring in an large patient population with
long-term follow-up. PATIENTS AND METHODS: Between October 1990 and May 1997, 400
patients were monitored at the Epilepsy Monitoring Unit (EMU) of the University
Hospital in Gent. In all patients, the following parameters were retrospectively
examined: reason for referral, tentative diagnosis, prescribed antiepileptic
drugs (AEDs), seizure frequency, number of admission days, number of recorded
seizures, ictal and interictal EEG, clinical and electroencephalographic
diagnosis following the monitoring session. During follow-up visits at the
Epilepsy Clinic, we prospectively collected data on different types of treatment
and post-monitoring seizure control. RESULTS: 255/400 (64%) patients were
referred for refractory epilepsy. 145/400 (36%) patients were evaluated for
attacks of uncertain origin. Mean follow-up, available in 225 patients, was 28
months (range: 6-80 months). Mean duration of a single monitoring session was 4
days (range: 2-7 days). Prolonged interictal EEG was recorded in all patients and
ictal EEG in 258 (65%) patients. Following the monitoring session, the diagnosis
of epilepsy was confirmed in 217 patients. Pseudoseizures were diagnosed in 31
patients (8%). AEDs were started in 19 patients, stopped in 6 and left unchanged
in 110. The type and/or number of AEDs was changed in 111 patients. Sixty
patients underwent epilepsy surgery. In 48 surgery patients, follow-up data were
available, 29 of whom became seizure-free, and 16 of whom experienced a greater
than 90% seizure reduction. Vagus nerve stimulation was performed in 11 patients,
2 became seizure-free, and 7 improved markedly. Of the non-invasively treated
patients in whom follow-up was available (n = 135), 70 became seizure-free or
experienced a greater than 50% reduction in seizure frequency; 51 patients
experienced no change in seizure frequency. Outcome was unrelated to the
availability of ictal video-EEG recording. In patients with complex partial
seizures, seizure control was significantly improved when a well-defined ictal
onset zone could be defined during video-EEG monitoring. CONCLUSION: Prolonged
interictal EEG monitoring is mandatory in the successful management of patients
with refractory epilepsy. Ictal video-EEG monitoring is very helpful but not
indispensable, except in patients enrolled for presurgical evaluation or
suspected of having pseudoseizures.
PMID- 10674144
TI - Cost-benefit of epilepsy surgery.
AB - A cost-benefit study of Epilepsy Surgery (ES) evaluates the monetary consequences
of the societal gain by reduced production loss. High direct cost of ES has been
addressed by suggesting simpler diagnostics, preference for certain
investigations, and weighing the direct cost against the postoperative savings.
New MRI technology has simplified diagnostics and, currently, the surgical
procedure is more accurate. A shortlasting procedure will reduce theater cost and
hospitalization. Resective procedures achieve freedom from seizures in 45-90%.
Postoperative worsening may be burdened by permanent morbidity, or may cause
death. Re-operation, an extra direct cost, yields freedom from seizures in 45
50%, being thereby justified health economically. If ES stops seizures at the
expense of impaired cognition, it is of limited help in restoring quality of
life. In adults, surgery often is performed late, and the social status may have
declined for the patient. Children with epilepsy and their families experience
social restrictions difficult to normalize. A successful outcome unaccompanied by
other improvement in life may turn into disappointment. Operated patients
employed preoperatively continue to be so postoperatively, or maintain their
employment which may also improve, an effect experienced even after a re
operation. But, a limited gain in employment after surgery has likewise been
reported. Early surgery has a positive effect on education and occupation. The
postoperative income of adults may increase significantly. Similarly, successful
pediatric surgery is cost-effective for the child and the family. Using seizure
free rate as effectiveness measure shows that ES is cheaper than AED treatment
alone. The high cost for advanced diagnostics should be seen in a long-term
perspective. The reduction in life long indirect cost after successful pediatric
surgery has been evaluated.
PMID- 10674146
TI - Presurgical assessment and surgical treatment for epilepsy.
AB - In the last ten years, dramatic advances in surgical treatment options and
techniques have allowed surgical intervention for patients who would otherwise
not have been considered as surgical candidates. In this article, a
multidisciplinary, logical decision algorithm for a rational approach to surgical
treatments is outlined. A carefully considered hierarchy is presented that
provides for maximized seizure improvement outcomes. Topics presented include
temporal lobectomy, detailed discussion of dominant temporal lobectomy and speech
sparing techniques, neocortical resection, the use of subdural electrode array,
depth electrodes, and strip electrodes, multiple subpinal transection, vagus
nerve stimulation, and corpus callosotomy. The application of these various
techniques to maximize surgical outcome are discussed.
PMID- 10674145
TI - Cost-benefit of vagus nerve stimulation for refractory epilepsy.
AB - PURPOSE: Vagus nerve stimulation (VNS) is an established treatment for patients
with medically refractory epilepsy who are unsuitable candidates for conventional
epilepsy surgery. VNS requires an initial financial investment but apart from our
own previous study there are no reports on cost-benefit published to date. The
purpose of this paper is to assess prospectively the cost-benefit ratio of VNS in
a series of patients with long term follow-up. METHODS: Our experience with VNS
comprises 25 patients of whom 20 with sufficient follow-up will be further
discussed. These 20 patients have a mean post-implantation follow-up of 26 months
(range: 6-50 months). Mean age was 30 years (range: 12-45 years); mean duration
of epilepsy 17 years (range: 5-35 years). We prospectively assessed seizure
frequency, prescribed AEDs, number of hospital admission days and side effects
and calculated the epilepsy related direct medical cost and compared this with
pre-implantation data. RESULTS: Mean seizure frequency decreased from 14
seizures/month (range: 2-40) to 9 seizures/month (range: 0-30) (p = 0.0003). The
mean yearly epilepsy related direct medical costs per patient dropped from 6,682
USD (range: 829-21,888 USD) to 3,635 USD (range: 684-12,486 USD) (p = 0.0046).
The mean number of hospital admission days was reduced from 16 days/year (range:
0-60) to 4 days/year (range: 0-30) (p = 0.0029). CONCLUSION: VNS is an
efficacious and cost-beneficial treatment for refractory partial seizures.
PMID- 10674147
TI - A psychoanalysis of love: the patient with deadly longing.
AB - Freud made some seriously mistaken assumptions about mature love based on his
notion about the role unconscious guilt plays in human affairs. Clinical data are
presented here about a young man, who implicated in the suicides of two of his
colleagues, was more concerned with the failure of his love affair in college
than with guilt for his involvement in the suicides. By tracing the functions of
shame--a concept the author contends that Freud failed to understand properly--in
the patient's relationship with his parents, the author formulates a proactive
and optimistic theory of mature love to replace Freud's pessimistic and
reductionistic explanation.
PMID- 10674148
TI - Interpreting transference in the supervision of psychoanalytic psychotherapy.
AB - Supervisors of analytic psychotherapy have long wrestled with the question of
whether interpretation has a legitimate role in dealing with supervisee
countertransference and the transferences of the supervisory experience, itself.
Currently, the majority view relies on didactic methods to deal with these
transferences and avoids interpretation as incompatible with, even dangerous to,
the supervisory task. This paper takes issue with this view and uses a clinical
example to illustrate the impact and irreplaceable value of direct interpretation
in supervision. It demonstrates that interpretation of a resistance in the
supervisee can fundamentally and beneficially affect the therapeutic
relationship, the supervisory process, and can have unanticipated diagnostic
significance. It also demonstrates that, when applied with the same
appropriateness and tact taken for granted in psychotherapy, concerns that
supervisory interpretation will be traumatizing or counterproductive are
unwarranted.
PMID- 10674149
TI - Therapy manuals and the dilemma of dynamically oriented therapists and
researchers.
AB - The presence of therapy manuals in clinical settings is increasing and the
related concepts of adherence and competence are becoming familiar. The benefits
of manuals for research and training are evident. However, negative clinical
effects have also been reported. Dynamically oriented clinicians and researchers
who use manuals face a dilemma. Although there is a need to control aspects of
technique for research and training purposes, there is also a need not to control
the process of therapy because unpredictability is an intended part of the
process. Issues associated with the dilemma are reviewed and a possible solution
is provided that has proven helpful in an active clinic and research setting. It
involves the use of manuals that emphasize general guidelines rather than
detailed technical behaviors.
PMID- 10674150
TI - Performative statements and the will: mechanisms of psychotherapeutic change.
AB - Performative statements are much discussed in the philosophy of language, e.g.,
by the linguistic philosopher, J. L. Austin, where they are distinguished from
descriptive statements. Whereas the latter merely describe a current state of
affairs from an external standpoint, performative statements enact a new state of
affairs merely by being spoken, as when a minister pronounces a couple married
during a wedding ceremony. Performative statements are words and deeds at the
same time. They are special kinds of statements, requiring certain unique
circumstances and relationships so that they can function validly. Leston Havens
has made the connection between the ability to make performative statements and
the setting of psychotherapy. He has asserted that performative statements are an
important part of the psychotherapeutic repertoire and may be an important force
in bringing about psychotherapeutic change. In this paper, I try to locate the
mechanism by which performative statements may achieve this effect, suggesting
that this occurs by means of influencing the patient's will directly.
Performative statements work on the will, much as descriptive statements
influence the intellect. Philosophical ideas about the will, like Aristotle's
notion of weakness of will, may explain some of the phenomena of psychotherapy,
including resistance.
PMID- 10674151
TI - "Generative caring" psychotherapy for patients who are reluctant to talk.
AB - Patients seek psychotherapy for relief of symptoms and resolution of problems in
living. Yet, they sometimes balk at the prospect of having to choose a topic
without being prompted by therapist questions. This paper suggests that this
apparently self-sabotaging behavior represents an acting out of a fundamental
existential dilemma for many individuals, i.e., to be or not to be an adult.
Adulthood comes with the heavy burden of responsibility for making life choices,
and the possibility of making the wrong choices. The psychotherapeutic situation,
with its demand that the patient choose a topic, is a microcosm of the adult
adult relationship. The author proposes that the proper treatment for these
patients is Generative Caring Psychotherapy, which promotes emotional growth and
facilitates patients' transition from childhood dependence to adult
responsibility.
PMID- 10674152
TI - A time-saving technique for the treatment of simple phobias.
AB - Two cases are presented in detail and two in summary fashion to illustrate a
technique that can frequently be used instead of systematic desensitization to
reduce the time needed to treat simple phobias. This method combines techniques
developed by Strategic Therapy and Critical Incident Debriefing. Symptoms that
the patient experiences as out of control are prescribed by the therapist and
then normalized. For example, a 26-year-old woman with a fear of social
situations learns that it is not unusual for people to feel somewhat awkward and
anxious as they try to reestablish themselves with friends after being away from
them for a long period of time. Therapy taught her to accept rather than fight
her initial anxiety in these situation. Another client with claustrophobia was
taught to imagine himself getting anxious and telling himself, "yes, this is
exactly what I expect. I am going to get anxious, and my anxiety will increase,
but it isn't going to get higher than a '5' (on a 1-10 scale), and I can handle
that." When these interventions are successful, the anxiety initially experienced
in a phobic situation as a signal for panic is reinterpreted in new situations as
expectable. This reframing renders the anxiety manageable. The treatment of two
additional patients is briefly presented to further illustrate the application of
this approach. Their phobias included a fear of sweating in public and a fear of
sleep.
PMID- 10674153
TI - Short-term dynamic therapy as a unique container.
PMID- 10674154
TI - The evolution of the internal dialogue during the psychoanalytic psychotherapy
process.
AB - This article illustrates curative changes occurring in psychoanalytic
psychotherapy by developing the internal dialogue in the mind. By the internal
dialogue, I mean the internalization of the therapy process during the recurrent
therapy sessions so that the external dialogue between therapist and patient
becomes the corresponding internal structure of the patient. In this way, there
is a development of the patient's capacity to identify himself and the therapist
as separate, sentient, thinking, and reflecting individuals, who have a free
internal world of their own. The evolution of the internal dialogue takes place
by gradually progressing symbolization achieved through a four-step symbolization
reflectiveness approach. This process is one of the specific curative factors in
the psychotherapeutic treatment of borderline patients. The psychodynamics are
illustrated by material from one session each of the early and the final stages
of therapy, showing a shift from monologue to internal dialogue. The evolved
internal dialogue is a central part of the patient's budding thinking capacity,
which creates a ground for her subjectivity and autonomy. This study underlines
and specifies three factors as cornerstones of the evolution of identity in
psychotherapy: symbolization, reflectiveness, and the internal dialogue.
PMID- 10674155
TI - Coming of age: the adolescent in psychotherapy.
AB - Psychotherapy clients in their adolescence are receptive to self-exploration.
When given the opportunity to reduce external distractions and directives, these
young individuals are serious seekers of emotional well-being. They also seek
quality and genuine interpersonal relationships. Gentle guidance within a safe
container encourages adolescents to explore their inner world.
PMID- 10674156
TI - Psychoanalytic pluralism and its vicissitudes.
PMID- 10674157
TI - A verified case of recovered memories of sexual abuse.
PMID- 10674158
TI - A survey of fragile X syndrome in a sample from Spanish Basque country.
AB - Fragile X syndrome is the most common inherited form of mental retardation. The
syndrome is associated with a CGG repeat expansion in the 5'UTR of the first exon
of the FMR1 gene. This gene maps to Xq27.3 and coincides with the cytogenetic
fragile site (FRAXA). The present study deals with the prevalence of fragile X
syndrome among individuals with mental retardation of unknown cause from
institutions and special schools from the Spanish Basque Country. Results of
cytogenetic and molecular studies, performed in a group of 134 unrelated
individuals (92 males and 42 females) are presented. The cytogenetic marker at
Xq27.3 was identified in 12 patients. Other chromosomal abnormalities were found
in two cases that this and previous studies confirmed as Angelman and Prader
Willi syndromes. Two males, in whom the cytogenetic marker was identified, were
found negative for FRAXA and FRAXE expansion at the molecular level. The present
study shows that the frequency of the FRAXA full mutation in individuals of
Spanish non-Basque origin is in the range of other Spanish populations. In the
sample of Spanish Basque origin we have not found cytogenetic FRAXA site
expression, and the CGG repeat size of FMR1 gene is in the normal range. The
significance of these results are discussed.
PMID- 10674159
TI - Double telomeric signals on single chromatids revealed by FISH and PRINS.
AB - FISH probes for all human telomeres and specific telomeric probes that hybridize
to unique sequences on individual chromosomes have been used to characterize the
telomeric hybridization pattern of human peripheral blood lymphocytes and bone
marrow cells in interphase and metaphase chromosomes. We have identified the
existence of double hybridization signals on chromatids both with the (TTAGGG)n
telomere repeat arrays and on non chromosome-specific subtelomeric regions as
well as on chromosome-specific sequences located several kilobases from the end
of chromosomes. Preliminary results using cosmid or YAC probes that hybridize to
regions rich in GC sequences also revealed double fluorescent spots on a single
chromatid. Double spots were detected by PRINS on terminal and interstitial
telomeric sequences in avian cells. The significance of this phenomenon is
discussed based on some models of chromatid and DNA organization such as uninemy,
looped chromatid organization and quartet DNA structures. The occurrence of
double spots should be taken into consideration for the clinical cytogenetic
diagnosis of duplications.
PMID- 10674160
TI - Cerebellar dysgenesis and mental retardation associated with a complex chromosome
rearrangement.
AB - Cerebellar hypoplasia, mild mental retardation, skeletal abnormalities, and
ataxia were present in a 40 years old patient with a complex chromosome
rearrangement (CCR). Chromosomes 2, 5, 16, and 17 were involved in the CCR. For
the definition of the eight breakpoints leading to the rearrangement FISH with
whole chromosomes paintings and specific telomeric probes was employed. Gene
disruption, positional effect variegation, and sub-microscopic deletions are all
possible causes for the abnormal phenotype observed in the patient.
PMID- 10674161
TI - Proximal trisomy 13q and distal monosomy 8p in a dysmorphic and mentally retarded
patient with an isodicentric chromosome 13q and a 13q/8p translocation
chromosome.
AB - A 40 year-old dysmorphic and mentally retarded female is reported with a de novo
unbalanced chromosomal rearrangement (karyotype:
46,XX,der(8)t(8;13)(p23;q123),idic(13)(pter-->q123: q123-->pter) resulting in an
isodicentric chromosome 13 and a double aneusomy including partial trisomy 13
(13pter-q123) and distal monosomy 8p (8pter-p23). The main clinical findings
consist of developmental/mental retardation, behavioural disturbances and minor
congenital defects, not consistent with the clinical pattern of either of the two
aneusomies. A mechanism for the chromosome rearrangement is proposed and the
absence of specific physical findings in the present patient is discussed in the
light of the available literature data.
PMID- 10674162
TI - Novel translocation t(3;11)(p21;q24) in multiple myeloma characterised by FISH.
AB - We present a 72 year old man with multiple myeloma (MM). Cytogenetic and FISH
analysis of bone marrow aspirate showed a novel translocation
der(11)t(3;11)(p21;q24). The unbalanced karyotype led to substantial partial
trisomy for chromosome 3p and small partial monosomy 11q. Structural
rearrangements of chromosome 3 are uncommon in MM and these are reviewed. The
patient died 2 years after the diagnosis of MM was made.
PMID- 10674163
TI - Schinzel-Giedion syndrome with severe deafness and neurodegenerative process.
AB - A case of Schinzel-Giedion syndrome with a follow-up of two and a half years is
reported. In addition to the classical features of the syndrome, the patient had
severe hearing loss with ossicular and cochlear malformations, alacrymia, and
progressive neurodegenerative disease.
PMID- 10674164
TI - A novel and very peculiar HincII polymorphism in the 5' region of the human
neurofibromatosis type 1 (NF1) gene.
AB - We report a HincII polymorphism in the 5' end of the neurofibromatosis type 1
gene (NF1) as detected with a probe made of exons 1 to 4a (nucleotides 2 to 401
of the cDNA). This HincII site is most probably in an intron. Evidence presented
suggests the probe reveals not one but two similar polymorphisms.
PMID- 10674165
TI - [French Society for Human Genetics. "Genetics in Practice" Commission. Core
scientific data of use in genetic counseling. Hemochromatosis].
PMID- 10674166
TI - [French Society for Human Genetics. "Genetics in Practice" Commission. Core
scientific data of use in genetic counseling. Familial Mediterranean fever].
PMID- 10674167
TI - Influence of dietary phosphorus depletion on central pathways of intermediary
metabolism in rats.
AB - Studies on P depleted rats compared with control animals kept under pair fed
conditions were carried out. Dietary P depletion led to reduced weight gain and a
decreased food conversion ratio in comparison with pair fed control animals.
Higher N retention, higher urea concentrations in plasma, liver and kidney
tissues and a significant reduction of renal glutamate dehydrogenase--a central
enzyme of amino acid degradation in kidney mitochondria--in P depleted animals
indicated changes in N utilization and N excretion. While lipid metabolism was
not affected by P depletion, carbohydrate metabolism was substantially changed in
the kidney: Activity of fructose diphosphatase was significantly reduced,
implicating a reduced gluconeogenesis in P depletion. Possible mechanisms of
these metabolic effects in P depletion are discussed.
PMID- 10674168
TI - Whole body protein turnover of growing rats in response to different dietary
proteins--soy protein or casein.
AB - Whole body protein turnover was studied in growing rats fed restrictively on
isoenergetic (GE 17.6 MJ/kg DM) and isonitrogenous (104 g CP/kg DM) diets based
on soy protein isolate or casein supplemented with D,L-methionine. During each of
the three separate experiments six male Fischer rats per group were housed
individually in metabolic cages at 24 degrees C. Prefeeding of both dietary
groups up to similar body weights at the start of the main experimental periods
(105-134 g) lasted up to 16 d for casein-fed rats and up to 30 d for the soy
protein-fed rats. Following the energy and nitrogen balance periods whole-body
protein synthesis was estimated by the end-product method using a single tracer
dose of a mixture of 15N-labelled amino acids. Fractional protein accretion rate
[% of the protein pool accreted per day] was significantly lower in soy protein
rats than in casein-fed rats in all three experiments whereas fractional
synthesis rate was not significantly lower. Therefore, protein breakdown
subsequently calculated as the difference between synthesis and accretion showed
a tendency towards higher values in this group. In soy protein-fed rats also a
tendency towards higher excretion of 3-methylhistidine as a marker of
myofibrillar protein breakdown was observed. It is concluded that increase in
lean tissue growth resulting from improved protein quality is brought about by
changes of both rates, by small increase of protein synthesis and by reduced rate
of body protein breakdown.
PMID- 10674169
TI - The course of phosphorus excretion in growing pigs fed continuously increasing
phosphorus concentrations after a phosphorus depletion.
AB - A balance study was performed in order to quantify the effect of continuously
increased phosphorus (P) intake on faecal and urinary P excretion. The aim was to
quantify the level of intake where regulatory P excretion becomes relevant for
comparative digestibility measurements on P, and when the pig adapts its urinary
P excretion to increased P intake. Phosphorus intake of growing pigs was
continuously increased on a daily basis starting at a marginal level and P
excretion via faeces and urine was continuously followed for 92 days. Two semi
synthetic diets were prepared with different proportions of Na2HPO4 resulting in
2.4 (diet 1) and 6.3 (diet 2) g P/kg DM. Concentration of Ca was adapted to
achieve a Ca supply approximately 3.1 fold the digestible P supply. Six castrated
male crossbred pigs (31 kg BW) were kept individually in metabolism crates after
they had undergone a 14 d P depletion period during which they were fed diet 1
solely. Pigs received 1.04kg of diet 1 per day throughout the experiment, and
each day the amount of feed and P supplied to pigs from diet 2 was increased by
12 g and 69 mg, respectively. ME supply was approximately 2.4 fold maintenance
and average daily BW gain of pigs during the entire experiment was 690 +/- 30 g.
While intake increased linearly, faecal excretion of P and Ca increased non
linearly and could be best described by third order polynomial functions. The
proportion of ingested P not excreted via faeces followed a quadratic type of
curve with a maximum of 81% at 25 days on experiment and P intake of 4.0 g/d.
Thereafter, the proportion decreased continuously. The digestibility of P from
diet 2, determined by the slope ratio technique, was constant and not affected by
P intake up to a P intake of 5 g/d. Renal P excretion did not exceed inevitable
losses until day 60 and increased exponentially thereafter when body P reserves
were restored. It is concluded, that an adaptation to surplus P supply occurred
earlier on the intestinal than on the renal level. While faecal P excretion
appeared regulated depending on the actual requirement for P retention, the
regulation via urine depended on the P status of the pig. Once the renal P
excretion of growing pigs exceeds a level of 25 mg/d, intake of digestible P
cannot be regarded sufficiently low to measure P digestibility as a capacity of
the feedstuff.
PMID- 10674170
TI - Passage of ribonucleic acid along the intestine of sheep.
AB - Sheep (Flemish female x Texel male, 55 kg BW), fitted with a PVC cannula in the
dorsal rumen and single T-shaped PVC cannulas in the proximal duodenum, distal
duodenum, mid-jejunum and terminal ileum were fed hay or hay-concentrate diets at
various levels of nitrogen and cell walls (NDF) (22 to 32 g N/d; 150 to 699 g
NDF/d). Co-EDTA and Cr-NDF were used as markers to measure the flow rate of
digesta. Ribonucleic acid (RNA) intestinal digesta and in rumen bacteria was
determined with orcinol after extraction with sodium chloride, precipitation with
tungstophosphoric acid and alkaline hydrolysis. The RNA:total N ratio in
bacteria, harvested from the rumen, amounted to 0.70 (CV 4.4%). The apparent
digestibility of RNA in different sections of the intestine was higher than of
total N. About 6% of RNA entering the duodenum disappeared between the proximal
and distal duodenum. At jejunum, the net disappearance of RNA amounted to 68% of
the quantity which entered the proximal duodenum. A higher result of 71% was
obtained at the ileum. Total net disappearance of RNA between the proximal
duodenum and rectum averaged 75%. Sixteen percent of RNA leaving the ileum was
apparently digested in the large intestine. The true digestibility of RNA between
the proximal duodenum and the terminal ileum, as estimated by multiple regression
analysis, amounted to 78%. Of the amount of RNA entering the ileum, 24% was of
endogenous origin. At ileum, the RNA passage was positively related to the ileal
flow of NDF (R2 = 0.67) and N (R2 = 0.94). The passage of RNA increased by 3 mg
RNA per g ileal indigestible NDF. Ileal endogenous N consisting of approximately
2% of endogenous RNA-N. In conclusion, the digestion capacity in the first part
of the small intestine is high. Rising flows of indigestible cell walls and
nitrogen increase the loss of ileal RNA. Further, using RNA as a microbial marker
to assess the amount of microbial protein entering the duodenum of ruminants,
digesta samples should be collected immediately post pylorus at the proximal
duodenum, in order to avoid underestimation of the microbial protein synthesis in
the rumen.
PMID- 10674171
TI - Morphological and functional development of the rumen in the calf: influence of
the time of weaning. 1. Morphological development of rumen mucosa.
AB - The objective of this study was to determine whether the nutritional regimen of
rearing calves would influence the morphometric and histological development of
rumen mucosa. Twelve male Holstein calves 7 d of age were assigned to three
groups of 4 animals each: milk group (I), early weaned (6 weeks) group (II) and
late weaned (9 weeks) group (III). All animals received additional solid feed.
Animals of group I were slaughtered after 6 weeks of age, whereas those in groups
II and III were slaughtered after 9 weeks of age. At slaughter, the ruminal
digesta amounted to 2035 g (milk group), 3092 g (late weaned group) and 5374 g
(early weaned group). The differences in the ruminal molar percentage of SCFA
were not significant. There was a trend for lower pH and higher SCFA
concentrations in the order late weaned, early weaned and milk fed animals (pH:
6.4, 6.6 and 6.7, respectively; SCFA: 96, 87 and 77 mmol/l, respectively). The
mean length (1.07 mm in milk group, 1.45 mm in late weaned group and 1.87 mm in
early weaned group), width (0.43, 0.58 and 0.71 mm, respectively) and surface of
papillae (190, 232 and 241 mm2/cm2 mucosa, respectively) increased with both the
age of the animals and the elevated intake of solid feed, whereas the number of
papillae (210, 140 and 92 per cm2 mucosa, respectively) decreased. In both milk
fed groups type A and B corneal cells were present in the Stratum corneum,
whereas in the earlier weaned calves type C-cells could be also seen. These
findings indicate a more advanced stage of development of the rumen epithelium in
the earlier weaned calves fed higher amounts of concentrate and hay.
PMID- 10674172
TI - Calculation of utilizable crude protein at the duodenum of cattle by two
different approaches.
AB - The duodenal flow of utilizable crude protein (crude protein minus endogenous
protein) in cows was estimated using dietary parameters, first by multiple
regression and secondly by the addition of microbial protein and undegraded feed
protein. These estimates were compared with 327 results from experiments
conducted with fistulated cows in Braunschweig-Volkenrode and Rostock
Dummerstorf. The regressions and the measurements for microbial protein synthesis
as well as feed protein degradation and organic matter fermentation in the rumen
were based on the same experimental data set. The prediction of utilizable crude
protein (uCP) at the duodenum by regression with digested organic matter (kg DOM)
and undegraded feed protein (g UDP) as predicting variables, was more accurate
than the value given by microbial protein synthesis and rumen protein
degradability. The regression model [g uCP = [188.5-(116.5 (UDP/CP))] DOM + 1.03
UDP] had the highest coefficient of determination (r2 = 0.91) and the lowest
coefficient of variation (cv = 8.6); indicating the model's superiority over the
other method of estimation.
PMID- 10674174
TI - Effect of two variables on the fatigue performance of acrylic bone cement: mixing
method and viscosity.
AB - The goal of the present work was to establish the relative influence of one
exogenous variable versus one endogenous variable on the fully-reversed tension
compression fatigue performance of bone cement. The method used to mix the cement
constituents was the exogenous variable, while the viscosity of the mixed cement
dough was the endogenous variable. Two commercial cement formulations (Palacos R
and Osteopal) and two cement mixing methods (hand mixing and vacuum mixing) were
used. It was found that for a given mixing method, cement viscosity exerts a
marginal influence on fatigue performance. On the other hand, for a given cement
formulation, vacuum mixing led to a statistically significant improvement in
fatigue performance. The present results demonstrate the superior influence of
mixing method over cement viscosity.
PMID- 10674173
TI - [The effect of palm oil and safflower oil in the feed of parent fattening hens on
fertility, hatchability and growth of progeny].
AB - The aim of two experiments with broiler breeder hens was to evaluate the effect
of diets containing palm butter or safflower oil (25 g and 50 g/kg feed, resp.)
on fertility, hatchability and growth of progeny. Especially the incorporation of
oleic and linoleic acid in egg yolk reflected the dietary fatty acid source. Eggs
were collected and stored in the incubator at a hen age of 31, 40, 50, and 60
weeks. Hatched chicks were reared over 5 weeks. The number of fertile eggs
(Experiment 1 and 2, 75 and 88%, resp.) differed between the experiments (P < or
= 0.05). Neither embryonic mortality nor hatchability (Experiment 1 and 2, 76 and
78%, resp.) were significantly affected by fatty acid composition of yolk. No
clear maternal dietary effect was recorded on chicken weight at hatching
(Experiment 1 and 2, 43.3 g and 43.7 g, resp.) and at 35 days of age
(Experimental 1 and 2, 1676 g and 1764 g, resp.) The fatty acid composition in
the analysed egg yolk sac of chicks showed a different fatty level but
corresponded to fatty acid composition of breeding eggs before incubation.
According to a decreased level of docosahexaenoic acid in egg yolk due to
increased incorporation of linoleic acid, the content of this fatty acid was also
diminished in phospholipids of the brain of chicken on days 1 and 5 after
hatching.
PMID- 10674175
TI - Evaluation of cytotoxicity of UHMWPE wear debris.
AB - We established a novel method to investigate the phagocytosis of ultra high
molecular weight polyethylene using primary macrophage cells by an inverted cell
culture method. Abundant wear debris derived from implant materials are generated
in aseptic loosening and are deposited in periprosthetic tissues in which they
are phagocytized by mono- and multi-nucleated macrophage like cells. Ultra-high
molecular-weight-polyethylene wear debris generated from different sources
namely, from laboratory test wear machine, in vivo methods and from knee and hip
simulator were mainly used in this investigation. The cytotoxicity index of the
different UHMWPE particles obtained from various sources were compared with that
of the PE beads and the control without particles by Alamar Blue and Neutral Red
assays. The results showed that the cytotoxicity index was significantly lower
for the wear debris from the in vivo experiments than that for other particles.
SEM analysis were also done to understand the morphology of the wear debris and
polyethylene beads and to confirm the phagocytosis process. The mean diameter of
the wear debris obtained from the in vivo experiments as estimated from the
imaging analysis of the SEM photographs was found to be the least. The inverted
cell culture method may be regarded as one of the good methods to study the
phagocytosis of UHMWPE by macrophage cells.
PMID- 10674176
TI - The effect of diameter ratio between vascular substitute and blood vessel on
anastomosis.
AB - It is necessary to maintain mechanical compatibility between a blood vessel and a
vascular substitute to promote encapsulation around the anastomosed part. From
this point of view, using linear elastic theory, we had previously performed
stress analyses at the part anastomosed by tissue adhesion, in order to propose
some methods of preventing stress concentration at this junction. In this study,
based on the previous analyses, we have attempted to develop a concept that can
be applied under the conditions of operation. That is, the initial diameter of a
vascular substitute with high rigidity is chosen larger than that of a blood
vessel. This will reduce the stress concentration around the anastomosed part, on
average, during expansion of the blood vessel. We analysed the optimum diameter
ratio between the vascular substitute and the blood vessel which causes the least
stress concentration, on average, during this process, using linear elastic
theory. Furthermore, numerical analyses of blood vessel deformation were
performed using various nonlinear stress-strain laws. These results were compared
to the analytical solution based on linear elastic theory.
PMID- 10674177
TI - Dynamics modeling of human temporomandibular joint during whiplash.
AB - The objective of this study is to simulate the dynamic response of the
temporomandibular joint forces within a rear-end impacted vehicle. Clinicians
reports symptoms of temporomandibular joint disorders in many patients who have
experienced vehicle rear-end impacts. In rear-end impact, a vehicle occupant's
head is thrust rearward with respect to the vehicle in a whiplash action. During
this motion, complex dynamic forces act on the jaw bone. To understand the
dynamic forces acting on the jaw, we extended an existing human head/neck model
by adding a movable jaw, and performed simulation of the jaw motions during rear
end impacts at 4.2, 6.4 and 9.6 m/s. Results predicted temporomandibular joint
torques, relative angle between the head and jaw, jaw angular acceleration and
linear acceleration of the jaw's center of mass.
PMID- 10674178
TI - Fatigue strength testing of hip stems with statistical analysis.
AB - Component fatigue testing, the final step in the development of total joint
replacements, is performed to validate the safety of these components against
fatigue failure before clinical use. Fatigue test prediction can aid the design
of an efficient fatigue-testing program. The objective of this study was to
perform an efficient and accurate statistical analysis of component fatigue test
results, for the validation of future fatigue test predictions. Testing was
performed with two aims: first, to determine the local component stress-force
relationship using strain gauges; and second, to provide a statistical
description of the fatigue test results. Forty-nine hip stems, in three sizes,
were tested in a series of static and fatigue tests. Through effective planning
and analysis, a statistical description of the component fatigue test results was
determined including, 3-parameter Weibull distributions of life at two stress
levels and log-Normal distributions of fatigue strength at various lives up to 5
million cycles.
PMID- 10674179
TI - Apoptosis induced by zinc deficiency in rat osteoblast: possible involvement of
protein kinase C.
AB - Rat osteoblasts were isolated from the 21-day fetal rat calvarias. The cells were
grown in DMEM plus 10% FBS, and were treated for 24 h. with 10 mumol/L TPEN or 10
mumol/L TPEN supplemented with 10 mumol/L Zn2+. Apoptosis of osteoblasts were
measured by flow cytometry, electron microscopy and DNA fragmentation analyzed by
gel electrophoresis. In addition, IP3 production and PKC activity were measured
in order to show whether they are involved in apoptosis in osteoblast induced by
zinc deficiency. The results showed that 10 mumol/L TPEN could induce apoptosis
in osteoblast in 24 h. But cells treated with 10 mumol/L TPEN supplemented with
10 mumol/L Zn2+ showed no apoptotic changes in 24 h. TPEN significantly reduced
the formation of IP3 and PKC activity after 24 h incubation. No differences were
observed between the cells treated with TPEN supplemented with Zn2+
simultaneously and the untreated cells. It can be inferred that apoptosis induced
by zinc deficiency may be due to the decreased activity of PKC which is impaired
by reduced formation of IP3.
PMID- 10674180
TI - Contribution of an auxin to the uptake of nickel and cadmium in maize seedlings.
AB - Maize seedlings were cultured in nickel or cadmium contaminated sand treated with
alpha-naphthylacetic acid (NAA). The effects of NAA on nickel and cadmium uptake
in roots, shoots, and subcellular fractions (cell wall, nuclei and remained parts
of seedling cells) were determined. The data showed growth promotion when NAA was
applied at low concentrations and inhibition at high concentrations. Uptake of
nickel and cadmium content increased concurrently in roots and shoots. In the
subcellular fraction, nickel and cadmium was greatest in the cell wall. The
changes in growth had greatest correlation with nickel and cadmium content in the
subcellular fraction.
PMID- 10674181
TI - Effects of nicotinamide on mouse skin tumor development and its mode of action.
AB - Nicotinamide (NA), a naturally occurring vitamin and a protease inhibitor, has
been shown to be effective in treating some skin ailments. It inhibits cell
proliferation and induces cell differentiation. This report shows the effects of
NA on mouse skin tumor development and on the critical events involved in this
process. NA reduced tumor growth, inhibited the 12-O-tetradecanoylphorbol-13
acetate (TPA) induced ornithine decarboxylase activity, but induced the
transglutaminase activity which was inhibited by TPA under different experimental
conditions. The effects of NA on ornithine decarboxylase (ODC) and
transglutaminase (TG) indicated that nicotinamide (NA) probably programmed the
cells for their death in the natural course of time, i.e. programmed cell death.
This observation indicates that NA might be a better agent for the detailed study
and for the better use in prevention of cancer alone or in combination with other
drugs.
PMID- 10674182
TI - Toxicological impact of benzenehexachloride on the behaviour and neuropathology
of Heteropneustes fossilis.
AB - Toxicological Impact of Benzenehexachloride on the behaviour and Neuropathology
of Heteropneustes fossilis. Organochlorine pesticides are widely used in the vast
agricultural fields of Assam, India. Run-offs from treated fields contaminates
nearby bodies of water with organochlorine compounds, which are neurotoxic to the
ichthyofouna. The present work was designed to study the effect of
bezenehexachloride on the behaviour and histopathology of Heteropneustes
fossilis, as an experimental model. The experimental fish were exposed to
different concentrations of the pesticide for 72 hours. After exposure, the fish
exhibited various behavioural changes. Histopathological examination of brain
tissue revealed cytopathic and gross histopathological alterations, including
necrosis and infractional changes. These results are consistent with the finding
that organochlorides cause neurotoxic effects.
PMID- 10674183
TI - Factors controlling bioindicators for industrial pollution detection.
AB - This study describes the use of algae as potential bioindicators of pollution
containing industrial metals. Phytoplanktonic algae varied with waste type and
with environmental and growth conditions. In water samples containing ceramic
waste Euglenophyta species and Cyclotella sp. (Bacillariophyta) were determined
as potential indicator species of pollution, while in sample containing metallic
waste, Cyclotella sp. was most dominant. Under laboratory growth conditions,
phytoplankton collected from a major stream of the Nile River were cultivated by
using Algal Growth Bottle Test (EPA, 1972). This revealed that Scenedesmus sp.,
Actinastrum hantzschii (Chlorophyta), Oscillatoria limnetica (Cyanophyta) and
Nitzschia linearis (Bacillariophyta) were also potential indicators of pollution.
PMID- 10674184
TI - Histomorphological and histochemical alterations following short-term inhalation
exposure to sulfur mustard on visceral organs of mice.
AB - Toxic effects of inhaled sulfur mustard (SM) on the histology of visceral organs
was investigated by exposing mice to 84.6 mg/m3 for 1 h duration, using
controlled single exposure conditions. A progressive fall in body weight from
third day onwards was noticed. Light microscopic examination of the pulmonary
tissue of these animals at 6 h post exposure revealed that the tracheobronchial
epithelium remained intact, but was infiltrated by inflammatory cells. By 24 h
post exposure, the mucosecretory cells were destroyed. The inflammatory reaction
was maximum at 48 h. By 7th day post exposure there was swelling and vacuolation
of lung parenchymal cells and thrombi formation. In addition SM caused congestion
and hemorrhage at alveolar level. SM also caused granulovacuolar degeneration
with perinuclear clumping of the cytoplasm of hepatocytes and renal parenchymal
cells. Renal lesions were characterized by congestion and hemorrhage. Among
visceral tissues, maximum atrophy was observed in spleen. Distribution of lesions
increased with post exposure period. The maximum lesions were observed at 7th day
post-exposure.
PMID- 10674185
TI - Influences of chloropazine, nimodipine and their combination on the toxic effects
of cadmium in liver and kidney of mice.
AB - The influences of the calmodulin antagonist chlorpromazine (CPZ), and calcium
channel blocker nimodipine (NIMO) and their combination on cadmium (Cd) poisoning
of mice were studied. A series of biochemical parameters including urinary enzyme
activities, blood and urine Cd levels, metallothionein (MT) contents in liver and
kidney, hepatic ultrastructure and Ca(2+)-Mg2+ ATPase activity in erythrocyte
membrane were determined. Animal models for Cd poisoning were established by
peritoneal injection of 1/5 LD50 CdCl2. The experimental groups were protected by
administration of CPZ, NIMO and CPZ and NIMO in combination 1 h before the
injection of CdCl2. Five days later, samples were collected for analysis. The
data showed that CPZ could protect kidney tissue against Cd-induced damage, as
the urinary gamma-glutamyl-traspeptidase (gamma-GT) and N-acetyl-beta-D
glucosaminidase (NAG) activities were reduced significantly. There was neither
evidence of the protective effect of NIMO on kidney tissue nor an indication of a
synergistic effect of CPZ and NIMO. Both CPZ and NIMO showed a considerable
protective effect against the decrease in Ca(2+)-Mg2+ ATPase activity, and a
synergistic action was observed. Cd content in blood was reduced significantly by
CPZ or the combination of CPZ and NIMO, but elevated by NIMO. Both CPZ and NIMO
considerably increased MT contents in livers and kidneys and ameliorated damaged
to the hepatic ultrastructures caused by Cd. The results indicated that these
inhibitors could protect mice against the toxic effects of Cd in liver and kidney
tissues, while CPZ was more efficient than NIMO. The combination of CPZ and NIMO
exerted a synergistic action. The protective action of these two drugs might be
relevant to the function of MT.
PMID- 10674186
TI - A preliminary investigation of the possible hypoglycemic activity of Hibiscus
rosa-sinensis.
AB - The hypoglycemic activity of an ethanol extract of Hibiscus rosa-sinensis was
studied in glucose located rats. After a single dose of the extract, a slight but
insignificant hypoglycemic effect was observed at 30 and 90 min. At 120 min it
was mild but significant. After repeated administration of the extract (once a
day for seven consecutive days) a statistically significant (P < 0.001) reduction
in blood glucose levels was observed at 30, 90 and 120 min after glucose loading.
The average hypoglycemic activity, after repeated administration of 250 mg kg-1
leaf extract was 81%, under similar conditions average activity of tolbutamide
was 96%. At 250 mg.kg-1 the efficacy of the extract was found to be 84% of
tolbutamide (100 mg.kg-1). Repeated treatment of animals either with tolbutamide
a sulphonylurea or H. rosa-sinensis caused a 2-3-fold improvement in glucose
tolerance as compared to those receiving only once. These data suggest that the
leaf extract acts like tolbutamide and the mechanism of action may be a
stimulation of pancreatic beta cells to produce more insulin or an increase of
the glycogen deposition in liver. It appears that the active principle in the
tested extract has the sulphonylurea skeleton in which-SO2-NH-CO-group and the
substituents (S1 and S2) may be the possible active sites responsible for its
hypoglycemic activity.
PMID- 10674187
TI - A review: progress of prevention and control on viral hepatitis in China.
PMID- 10674188
TI - Anatomic and molecular principles of psychopharmacology. A primer for
psychiatrists.
AB - Psychopharmacology uses chemicals to modulate human brain function. Three basic
principles of neurotransmission may help to understand the current practice of
clinical psychopharmacology. First, the anatomic organization of neurotransmitter
systems determines their behavioral affiliation. Second, neurotransmitter
receptors modulate the electrical properties (via ion channels) or the
biochemical properties (via second-messenger systems) of neurons. Third, the
intracellular integration of receptor-mediated responses leads to immediate or
delayed effects on neuronal function.
PMID- 10674189
TI - Pharmacogenetics. Promise and potential in child and adolescent psychiatry.
AB - The range of recent promising clinical applications of pharmacogenetics, the
nature of genetic research on pharmacokinetic and pharmacodynamic issues, the
possible contribution of pharmacogenetics to understanding pathogenesis, and the
appropriate genetic methods to be employed are reviewed in this article.
Following an overview of the research on the role of dopamine- and serotonin
related alleles in influencing risk to neuropsychiatric disorders, separate
sections then review the specific pharmacogenetic studies examining the effects
of dopamine- and serotonin-related genes on drug response. The potential use of
pharmacogenetics in child and adolescent psychopharmacology and the possible
directions for future research also are discussed.
PMID- 10674190
TI - Cytochrome P450-mediated drug interactions.
AB - In this article, the authors have provided child psychiatrists with cytochromal
concepts, illustrations of common CYP-based drug interactions, and CYP tables.
Clinicians can use these tables to anticipate drug interactions. If two
medications are listed on the same CYP, a drug interaction may occur, and
depending on whether they are substrates, inducers, or inhibitors, clearance of
one or both drugs may be altered. Because new information about CYPs rapidly
becomes available, however, CYP tables have a short shelf life. To further
predict and reduce the consequences of CYP-based drug interactions, child
psychiatrists can limit their own formularies and review PubMed, Ovid, or other
literature tracking programs each time they use two or more drugs (including
nonpsychiatric ones). The following Internet websites can provide current CYP
data: CYP charts http//:@www.dml.georgetown.edu/depts/ph armac
ology/clinlist.html http//:@www.accp.com/p450.html CYP drug interaction program
http//:@www.mhc.com/Cytochromes/ AIDS drug interactions
http//:@www.tthhivclinic.com/interactions.htm
http//:@www.fda.gov/oashi/aids/pitabv. htm l
http//:@HIV.medscape.com/Medscape/HIV/DrugInteract+ ++ ion s/index.html
http//:@www.hopkins-aids.edu/geneva/hilites_f le x_d rug.html.
PMID- 10674191
TI - Pharmacotherapy of attention deficit hyperactivity disorder.
AB - Despite a large body of literature documenting the effectiveness of medication in
the treatment of ADHD, there has been public and professional concern regarding
the possible inappropriate diagnosis and prescription of ADHD medications.
Recently the Council of Scientific Affairs of the American Medical Association
addressed these concerns in a scholarly review. Several factors were identified
that contributed to existing controversies: (1) Like most psychiatric disorders,
diagnostic criteria for ADHD are based on history and behavioral assessment.
There are no pathognomonic laboratory or radiologic tests to confirm the
diagnosis. (2) Attention deficit hyperactivity disorder is a chronic disorder and
requires extended treatment. (3) Treatment includes potentially abusable
medications. After a review of the voluminous literature, this distinguished
panel concluded that ADHD is one of the best researched disorders in medicine; in
fact, the overall data on its validity are far more compelling than for many
other medical conditions. They also concluded that there was little evidence of
widespread overdiagnosis or misdiagnosis of ADHD or of widespread
overprescription of stimulants by physicians. Consistent with the current
emphasis on cognitive dysregulation in ADHD, treatment concerns have expanded
from a primarily behavioral focus to include enhancement of executive functions
in scholastic as well as other settings. Although stimulants have been the most
studied compounds, there is a considerable body of literature indicating an
important role for other psychopharmacologic agents. Noradrenergic and
dopaminergic modulation appears to be necessary for effective anti-ADHD
treatment. In addition, promising evidence of newer cholinergic agents may
provide other useful alternatives. As with all psychiatric disorders, comorbid
conditions are prominent and may lead to high morbidity and disability if not
addressed. As with other areas of medicine, it is sometimes necessary to use
multiple agents to treat comorbidity or to achieve an effective response.
PMID- 10674192
TI - Pharmacologic treatment of tic disorders.
AB - The approach to treating children and adolescents with tic disorders has evolved
in recent years such that complete elimination of tics is no longer the primary
goal of treatment. Indeed, given the high frequency of psychiatric comorbidity in
TS, treatment planning begins with identification of target symptoms. Although
traditional neuroleptics still represent standard treatment for tics, many
families and clinicians are reluctant to use these agents because of concern
about the potential for short- and long-term side effects. Thus, there is great
interest in the newer atypical neuroleptics. Interest in the atypical
neuroleptics is understandable, but much more study is needed before these agents
can become first-line treatments for tics. A small group of non-neuroleptic
medications have been used in the treatment of tics. Of these, clonidine,
guanfacine, tetrabenazine, pergolide, and botulinum toxin injections have shown
some promise for suppressing tics. To date, however, only clonidine has been
evaluated in randomized, controlled trials, and the results are not consistent
across studies. Although comorbid ADHD is common in children with TS, treatment
with stimulant medications was not recommended in children with tics. Recent data
suggest that stimulants may be used in some children with TS without adverse
effects. Until more is known about which children with ADHD and tic disorders can
be safely treated with stimulants, however, the use of stimulants in this
population should be undertaken with caution. A handful of nonstimulant
medications have been used in the treatment of ADHD with some success, but more
study is needed for most of these agents. Evaluation of the stimulants and
nonstimulants for the treatment of ADHD in children and adolescents with tic
disorders is an area worthy of large controlled trials.
PMID- 10674194
TI - Pharmacotherapy of early-onset depression. Update and new directions.
AB - Although an increased recognition of depressive disorders in youth represents a
positive conceptual change over the past decades, there still is a very limited
amount of research on useful treatment interventions. The paucity of data is
particularly keen for the use of psychotropic drugs. For example, by applying the
criteria suggested by the International Psychopharmacology Algorithm Project,
there barely are enough first-grade ("Level A," meaning at least two RCTs) data
supporting the short-term efficacy of antidepressants (the SSRIs) in the
treatment of juvenile depression. And yet, limited data have not translated into
limited use in routine clinical practice. In fact, the use of antidepressant
medications has increased exponentially over the last decade, a change that is
especially conspicuous for individuals less than 18 years of age. The perceived
safety of the SSRIs and other novel antidepressants is partly at the root of
their increased popularity. Data regarding their safety are likewise quite
limited, however, and essentially are nonexistent for longer-term use. Based on
the reviewed data, a medication algorithm for the treatment of early-onset
depression can be suggested (Fig. 1). The algorithm underscores the need for
adequate evaluation and diagnostic assessment, with particular attention to
comorbid conditions (such as a bipolar diathesis) that may dictate alternative
treatment strategies. In general, psychotherapy is the initial approach to
juvenile MDD, with medication use reserved for more severe cases or those not
responding to psychotherapy alone. Given that only two types of psychotherapy and
two SSRIs have adequate controlled short-term efficacy data, all but the initial
steps must be undertaken guided by clinical judgment and an individualized risk
benefit analysis. An algorithm such as this one, based on the very limited
efficacy and safety data available, may be viewed as setting priorities for a
comprehensive research agenda, more than dictating rigid treatment guidelines. In
closing, it can be suggested that future research on the pharmacotherapy of early
onset depressive disorder pay particular attention to the following three
aspects: 1. Too many drugs, too few data: Rapid advances in drug development have
led to a plethora of available antidepressant agents. It is clear that there are
many more agents available than can be adequately studied at present. Because
many such agents are mechanistically similar, if not identical, it may be wise to
focus research efforts on truly novel agents, particularly those (such as the CRH
receptor antagonists, or those affecting neurosteroidogenesis) whose action is
based on preclinical and clinical pathophysiologic disease paradigms. 2.
Longitudinal follow-up and maintenance studies: Essentially all reviewed
treatment studies have been short-term trials. There is a marked paucity of
longer-term follow-up data, or of naturalistic and "real-world" effectiveness
studies. For example, one of the few studies addressing maintenance
pharmacotherapy for early-onset depression has demonstrated surprisingly high
recurrence rates, even for those subjects actively on maintenance medication. 3.
Long-term safety: Clinicians and parents alike often face difficult decisions
regarding the long-term exposure of antidepressant drugs on the developing brain.
Although no definitive long-term safety data are likely to become available
anytime soon, real risks, such as suicide, and potential sequelae of long-term
exposure to the underlying illness itself need all to be part of any decision
making process. Preclinical studies have shown that brain-derived neurotrophic
factor (BDNF) levels can be upregulated by antidepressants, and low BDNF factors
have been associated with atrophic brain changes in recurrent forms of adult MDD.
Although these observations require specific application to juvenile forms of the
disorder, they raise the exciting prospect that the natural course of the illne
PMID- 10674193
TI - Pharmacologic treatment of anxiety disorders in children and adolescents.
AB - This article reviews the pharmacologic treatment of anxiety disorders in children
and adolescents. These disorders are quite common and can be considered a "silent
epidemic" because they are more often reported by the children and adolescents
than by their parents. Tricyclic antidepressants (TCAs), benzodiazepines,
buspirone, and selective serotonin reuptake inhibitors (SSRIs) have been used to
treat anxiety disorders in children and adolescents with varying degrees of
success. Considering safety and efficacy, the SSRIs appear to be the first-line
treatment for anxiety disorders in youth, but more studies are needed to confirm
preliminary results. Tricyclic antidepressants and benzodiazepines may be
considered when the child has not responded to SSRIs or when adverse effects have
exceeded benefits. Although nonpharmacologic approaches for the treatment of
anxiety in children and adolescents are beyond the scope of this article, their
importance is to be underscored and they should be considered as part of the
treatment plan. Over the next decade, research data will be generated regarding
the treatment of anxiety disorders in youth. Ongoing research studies include the
use of fluoxetine (B. Birmaher, personal communication, 1999) and fluvoxamine (J.
Walkup, personal communication, 1999) for the treatment of generalized anxiety
disorder, separation anxiety disorder, or social phobia; and buspirone for
generalized anxiety disorder in children. Despite these efforts, there is a need
for more studies to examine the safety and efficacy of different pharmacologic
treatments, as well as longitudinal studies to monitor for long-term tolerability
and side effects. Pharmacokinetic studies for children and adolescents will
provide information on the metabolism and absorption of these medications and
delineate the developmental differences between children and adolescents when
compared to adults. Finally, and perhaps most importantly, studies that compare
medication, psychosocial treatments, and their combination are needed.
PMID- 10674195
TI - Mood stabilizers in the treatment of juvenile bipolar disorder. Advances and
controversies.
AB - Controlled studies of mood stabilizer (mono and combination) therapy are needed
in children and adolescents to develop safe and effective treatment strategies
for a disorder that now has a cohort and that carries a high human and economic
cost. Through the use of a variety of diagnostic instruments and novel outcome
measures, we may continue to refine DSM categories into more sensitive and
specific diagnostic constructs. In addition, identification of neurobiologic and
genetic markers for early-onset BPD, ADHD, CD, and IED could provide powerful
tools in the process of breaking down phenotypes and establishing biologic
predictors of targeted pharmacologic interventions in the face of new drug
developments.
PMID- 10674196
TI - The diagnosis and treatment of children and adolescents with schizophrenia. "My
mind is playing tricks on me".
AB - This article discusses the clinical phenomenology, natural history, neurobiologic
features, diagnostic and medical assessment, and management of schizophrenia, and
also details pharmacologic treatments.
PMID- 10674197
TI - Research Units on Pediatric Psychopharmacology (RUPP) Autism Network. Background
and rationale for an initial controlled study of risperidone.
AB - This article has reviewed the background and rationale for the choice of
risperidone as the first drug to be studied by the RUPP Autism Network.
Risperidone has potent effects on 5-HT and DA neuronal systems, both of which
have been implicated in the pathophysiology of autism. Unlike the typical
antipsychotics, haloperidol and pimozide, which have been shown to be effective
for reducing many of the maladaptive behaviors associated with autism,
risperidone's 5-HT2A/DA D2 ratio of receptor blockade appears to produce a lower
risk of acute and chronic extrapyramidal side effects, as well as enhanced
efficacy for the "negative" symptoms of autism. Indirect clinical and preclinical
evidence supports the use of risperidone to treat impaired social behavior,
interfering repetitive phenomena, and aggression, targets of pharmacotherapy for
many patients with autism. Numerous published open-label trials in children and
adolescents with autism and related PDDs and one double-blind, placebo-controlled
study in adults suggest that risperidone has promise for the treatment of
children and adolescents with autism. Because most of these studies have been
short-term, open-label trials in small samples, however, a large-scale controlled
study of risperidone in children and adolescents with autism is needed to confirm
these results. Finally, because it is likely that children who demonstrate short
term benefit from risperidone will remain on the medication indefinitely, the
longer-term effectiveness and safety of risperidone in this population also needs
to be determined. The design of this study and the assessments used are described
separately.
PMID- 10674198
TI - Pharmacologic management of psychiatric and behavioral symptoms in mental
retardation.
AB - Compared with the general population, individuals with mental retardation
demonstrate more susceptibility to psychiatric illness and may display disruptive
behaviors. These symptoms significantly can affect an already compromised ability
to function and the patient may benefit from pharmacologic intervention. Clinical
characteristics of individuals with mental retardation warrant special
consideration regarding diagnosis and treatment of their psychiatric and
behavioral problems. This article describes the nature of symptoms that are
typically the target of pharmacologic intervention, outlines special diagnostic
considerations, and examines recent findings and experience with psychotropic
medication in mental retardation.
PMID- 10674199
TI - Practical clinical issues regarding child and adolescent psychopharmacology.
AB - The psychotropic treatment of child and adolescent psychiatric disorders is
becoming increasingly common. In many cases, its clinical use outstrips its
demonstrated scientific validity. Pharmacologic compounds need to be properly
utilized, effectively prescribed, and appropriately monitored. This entails a
detailed knowledge of various psychotropic agents, their pharmacokinetics and
pharmacodynamics, and a high degree of psychotherapeutic sophistication in terms
of the patient-family-physician relationship.
PMID- 10674200
TI - Lycopene in tomatoes: chemical and physical properties affected by food
processing.
AB - Lycopene is the pigment principally responsible for the characteristic deep-red
color of ripe tomato fruits and tomato products. It has attracted attention due
to its biological and physicochemical properties, especially related to its
effects as a natural antioxidant. Although it has no provitamin A activity,
lycopene does exhibit a physical quenching rate constant with singlet oxygen
almost twice as high as that of beta-carotene. This makes its presence in the
diet of considerable interest. Increasing clinical evidence supports the role of
lycopene as a micronutrient with important health benefits, because it appears to
provide protection against a broad range of epithelial cancers. Tomatoes and
related tomato products are the major source of lycopene compounds, and are also
considered an important source of carotenoids in the human diet. Undesirable
degradation of lycopene not only affects the sensory quality of the final
products, but also the health benefit of tomato-based foods for the human body.
Lycopene in fresh tomato fruits occurs essentially in the all-trans
configuration. The main causes of tomato lycopene degradation during processing
are isomerization and oxidation. Isomerization converts all-trans isomers to cis
isomers due to additional energy input and results in an unstable, energy-rich
station. Determination of the degree of lycopene isomerization during processing
would provide a measure of the potential health benefits of tomato-based foods.
Thermal processing (bleaching, retorting, and freezing processes) generally cause
some loss of lycopene in tomato-based foods. Heat induces isomerization of the
all-trans to cis forms. The cis-isomers increase with temperature and processing
time. In general, dehydrated and powdered tomatoes have poor lycopene stability
unless carefully processed and promptly placed in a hermetically sealed and inert
atmosphere for storage. A significant increase in the cis-isomers with a
simultaneous decrease in the all-trans isomers can be observed in the dehydrated
tomato samples using the different dehydration methods. Frozen foods and heat
sterilized foods exhibit excellent lycopene stability throughout their normal
temperature storage shelf life. Lycopene bioavailability (absorption) can be
influenced by many factors. The bioavailability of cis-isomers in food is higher
than that of all-trans isomers. Lycopene bioavailability in processed tomato
products is higher than in unprocessed fresh tomatoes. The composition and
structure of the food also have an impact on the bioavailability of lycopene and
may affect the release of lycopene from the tomato tissue matrix. Food processing
may improve lycopene bioavailability by breaking down cell walls, which weakens
the bonding forces between lycopene and tissue matrix, thus making lycopene more
accessible and enhancing the cis-isomerization. More information on lycopene
bioavailability, however, is needed. The pharmacokinetic properties of lycopene
remain particularly poorly understood. Further research on the bioavalability,
pharmacology, biochemistry, and physiology must be done to reveal the mechanism
of lycopene in human diet, and the in vivo metabolism of lycopene. Consumer
demand for healthy food products provides an opportunity to develop lycopene-rich
food as new functional foods, as well as food-grade and pharmaceutical-grade
lycopene as new nutraceutical products. An industrial scale, environmentally
friendly lycopene extraction and purification procedure with minimal loss of
bioactivities is highly desirable for the foods, feed, cosmetic, and
pharmaceutical industries. High-quality lycopene products that meet food safety
regulations will offer potential benefits to the food industry.
PMID- 10674201
TI - Fish protein hydrolysates: production, biochemical, and functional properties.
AB - Considerable amounts of fish processing byproducts are discarded each year. By
developing enzyme technologies for protein recovery and modification, production
of a broad spectrum of food ingredients and industrial products may be possible.
Hydrolyzed vegetable and milk proteins are widely used food ingredients. There
are few hydrolyzed fish protein foods with the exception of East Asian condiments
and sauces. This review describes various manufacturing techniques for fish
protein hydrolysates using acid, base, endogenous enzymes, and added bacterial or
digestive proteases. The chemical and biochemical characteristics of hydrolyzed
fish proteins are discussed. In addition, functional properties of fish protein
hydrolysates are described, including solubility, water-holding capacity,
emulsification, and foam-forming ability. Possible applications of fish protein
hydrolysates in food systems are provided, and comparison with other food protein
hydrolysates where pertinent.
PMID- 10674202
TI - Toward practical definitions of quality for food science.
AB - A new practical approach to developing workable definitions of quality is
presented to overcome the numerous semantic and conceptual difficulties that are
common with the use of the word quality in food science. This approach links the
concept of quality, through a general definition, by adding the missing link of
specific definitions related to measurable attributes and properties determined
by standard methods to provide values that can be used to evaluate foods or to
set specifications. It is compatible with control, assurance, HACCP, regulatory,
TQM, and other normal uses of the both the word quality, and the concept quality,
in food science and technology.
PMID- 10674203
TI - Health care for the homeless: a model for nursing education.
PMID- 10674204
TI - The deadly return of tuberculosis.
PMID- 10674205
TI - South Africa responds to a TB emergency.
PMID- 10674206
TI - A strong nursing role in tuberculosis control.
PMID- 10674207
TI - How new mothers acquire knowledge in a hospital setting.
PMID- 10674208
TI - Teaching collective health in nursing schools.
PMID- 10674209
TI - NMR in biotechnology.
PMID- 10674210
TI - Measurement of intracellular (compartmental) pH by 31P NMR in Aspergillus niger.
AB - 31P nuclear magnetic resonance (31P NMR) was used to monitor cytoplasmic and
vacuolar pH values in the filamentous fungus Aspergillus niger. To obtain a
homogeneous cell sample and to be able to perform long term in vivo NMR
measurements A. niger mycelium was kept in a setup that allows perfusion of the
cell plug within the NMR tube. Mycelial samples, however, became rapidly clogged
during perfusion leading to (partial) anaerobiosis of the plug with subsequent
acidification of the cytoplasm. As a result, only short-term NMR measurements (5
10 min) were possible using free mycelium. To increase and to prolong perfusion,
A. niger was immobilized in Ca(2+)-alginate beads. Deteriorated spectra recorded
under hypoxia could be completely restored in the presence of oxygen. With this
system perfusion in the presence of citrate could be maintained for at least 18 h
at much higher rates (15 ml min-1 compared with 4 ml min-1 for free mycelium).
During this period 31P NMR spectra were highly invariable, indicating approximate
steady-state intracellular conditions during long term measurements. Perfusion in
the presence of glucose resulted in complete depletion of the vacuolar inorganic
phosphate pool within 45 min and yielded a higher pH gradient over the tonoplast
than when citrate was used (delta pH = 1.6 and 1.4, respectively).
PMID- 10674211
TI - Analysis of sugar metabolism in an EPS producing Lactococcus lactis by 31P NMR.
AB - Sugar metabolism and exopolysaccharide (EPS) production was analysed in
Lactococcus lactis by in vivo 31P NMR. Transient production of several sugar
phosphates, transient depletion of intracellular phosphate, transient production
of ATP and UTP, transient acidification of the medium and alkalinisation of the
cytoplasm could be observed in a period of 20 min upon energization by the
addition of glucose. EPS and non-EPS producing variants showed similar NMR
spectra, the exception being two pH-dependent resonances observed in the former.
They were already observed before addition of glucose and their response to
glucose incubation reflected exposure to the medium. They are presumably
phosphorylated poly- or oligosaccharides being loosely adhered to cell walls. By
freezing and perchloric acid extraction of the cell material, different types of
phosphorylated compounds could be recognised in the NMR spectra such as fructose
1-6-diphosphate, nucleotides (like ADP, ATP, UTP and TDP) and several nucleotide
sugars. The ongoing work is focused on identifying the unknown peaks and
quantifying the differences between wild-type cells and the EPS producing
variant.
PMID- 10674212
TI - Determination of full 13C isotopomer distributions for metabolic flux analysis
using heteronuclear spin echo difference NMR spectroscopy.
AB - 13C-isotopomer labeling experiments play an increasingly important role in the
analysis of intracellular metabolic fluxes for genetic engineering purposes. 13C
NMR spectroscopy is a key technique in the experimental determination of
isotopomer distributions. However, only subsets of isotopomers can be quantitated
using this technique due to redundancies in the scalar coupling patterns and due
to invisibility of the 12C isotope in NMR. Therefore, we developed and describe
in this paper a 1H NMR spectroscopy method that allows to determine the complete
isotopomer distribution in metabolites having a backbone consisting of up to at
least four carbons. The proposed pulse sequences employ up to three alternately
applied frequency-selective inversion pulses in the 13C channel. In a first
application study, the complete isotopomer distribution of aspartate isolated
from [1-13C]ethanol-grown Ashbya gossypii was determined. A tentative model of
the central metabolism of this organism was constructed and used for metabolic
flux analysis. The aspartate isotopomer NMR data played a key role in the
successful determination of the flux through the peroxisomal glyoxylate pathway.
The new NMR method can be highly instrumental in generating the data upon which
isotopomer labeling experiments for flux analysis, that are becoming increasingly
important, are based.
PMID- 10674213
TI - 13C and 1H NMR study of cellulose metabolism by Fibrobacter succinogenes S85.
AB - Fibrobacter succinogenes S85, a cellulolytic rumen bacterium, is very efficient
in degrading lignocellulosic substrates and could be used to develop a
biotechnological process for the treatment of wastes. In this work, the
metabolism of cellulose by F. succinogenes S85 was investigated using in vivo 13C
NMR and 13C-filtered spin-echo difference 1H NMR spectroscopy. The degradation of
unlabelled cellulose synthesised by Acetobacter xylinum was studied indirectly,
in the presence of [1-13C]glucose, by estimating the isotopic dilution of the
final bacterial fermentation products (glycogen, succinate, acetate). During the
pre-incubation period of F. succinogenes cells with cellulose fibres, some cells
('non-adherent') did not attach to the solid material. Results for 'adherent'
cells showed that about one fourth of the glucose units entering F. succinogenes
metabolism originated from cellulose degradation. A huge reversal of succinate
metabolism pathway and production of large amounts of unlabelled acetate which
was observed during incubation with glucose only, was found to be much decreased
in the presence of solid substrate. The synthesis of glucose 6-phophate was
slightly increased in the presence of cellulose. Results clearly showed that 'non
adherent' cells were able to metabolise glucose very efficiently; consequently
the metabolic state of these cells was not responsible for their 'non-adherence'
to cellulose fibre.
PMID- 10674214
TI - Relevance and isotopic assessment of hexose-6-phosphate recycling in micro
organisms.
AB - Some pathways of hexose-6-phosphate recycling--those involving a breakdown of the
hexose skeleton--through carbohydrate metabolism of micro-organisms were analyzed
for both metabolic and isotopic effects. Two modes of recycling were proposed
based on the degree of alteration of the hexose molecule through the catabolic
part of the cycle. Simulated operation of most of these pathways resulted in
increased synthesis of hexose-6-phosphate and NADPH, and reduced the NADH and
moreover the ATP synthesis within the carbohydrate metabolism. A basic model for
the quantitative assessment by means of isotopic studies of the processes of
hexose-6-phosphate recycling is presented. The model was initially designed for
the study of micro-organisms producing polysaccharides, but it can be extended to
other situations.
PMID- 10674215
TI - Introduction of polyphosphate as a novel phosphate pool in the chloroplast of
transgenic potato plants modifies carbohydrate partitioning.
AB - Potato plants (Solanum tuberosum L., cv. Desiree) were transformed with the
polyphosphate kinase gene from Escherichia coli fused to the leader sequence of
the ferredoxin oxidoreductase gene (FNR) from Spinacea oleracea under the control
of the leaf specific St-LS1 promoter to introduce a novel phosphate pool in the
chloroplasts of green tissues. Transgenic plants (cpPPK) in tissue culture
developed necrotic lesions in older leaves and showed earlier leaf senescence
while greenhouse plants showed no noticeable phenotype. Leaves of cpPPK plants
contained less starch but higher concentrations of soluble sugars. The presence
of polyphosphate in cpPPK leaves was demonstrated by toluidine blue staining and
unambiguously verified and quantified by in vitro 31P-NMR of extracts.
Polyphosphate accumulated during leaf development from 0.06 in juvenile leaves to
0.83 mg P g-1 DW in old leaves and had an average chain length of 18 residues in
mature leaves. In situ 31P-NMR on small leaf pieces perfused with well-oxygenated
medium showed only 0.036 mg P g-1 DW polyphosphate that was, however, greatly
increased upon treatment with 50 mM ammonium sulfate at pH 7.3. This phenomenon
along with a yield of 0.47 mg P g-1 DW polyphosphate from an extract of the same
leaf material suggests that 93% of the polyphosphate pool is immobile. This
conclusion is substantiated by the observation that no differences in
polyphosphate pool sizes could be discerned between darkened and illuminated
leaves, leaves treated with methylviologen or anaerobis and control leaves,
treatments causing a change in the pool of ATP available for polyPi synthesis.
Results are discussed in the context of the chelating properties of
polyphosphates for cations and its consequences for the partitioning of
photoassimilate between starch and soluble sugars.
PMID- 10674216
TI - Strategies for metabolic flux analysis in plants using isotope labelling.
AB - Flux measurements through metabolic pathways generate insights into the
integration of metabolism, and there is increasing interest in using such
measurements to quantify the metabolic effects of mutation and genetic
manipulation. Isotope labelling provides a powerful approach for measuring
metabolic fluxes, and it gives rise to several distinct methods based on either
dynamic or steady-state experiments. We discuss the application of these methods
to photosynthetic and non-photosynthetic plant tissues, and we illustrate the
different approaches with an analysis of the pathways interconverting hexose
phosphates and triose phosphates. The complicating effects of the pentose
phosphate pathway and the problems arising from the extensive compartmentation of
plant cell metabolism are considered. The non-trivial nature of the analysis is
emphasised by reference to invalid deductions in earlier work. It is concluded
that steady-state isotopic labelling experiments can provide important
information on the fluxes through primary metabolism in plants, and that the
combination of stable isotope labelling with detection by nuclear magnetic
resonance is particularly informative.
PMID- 10674217
TI - Chemical fingerprinting for the evaluation of unintended secondary metabolic
changes in transgenic food crops.
AB - A common element in designed guidelines for assessment of the food safety of
transgenic crops is centred on a comparative analytical analysis with
conventionally bred crop plants, assuming that these products have a long history
of safe use (i.e. OECD-principle of substantial equivalence). In this study we
examine the utility of an off-line combination of 400 MHz proton (1H)-NMR
spectroscopy and liquid chromatography (LC) for the multi-component comparison of
low-molecular weight compounds (i.e. chemical fingerprinting) in complex plant
matrices. The developed NMR-methodology can contribute to the demonstration of
substantial equivalence by its ability to compare possible compositional
alterations in a novel food crop with respect to related non-transgenic reference
lines. In this respect a hierarchical approach is proposed by comparing the
chemical fingerprints of the transgenic crop plant to those of: (1) isogenic
parental or closely related lines bred at identical and multiple sites; (2)
extended ranges of commercial varieties of that plant; and (3) downstream
processing effects. This is of importance to assess the likelihood that some of
the statistical differences in a transgenic crop plant may be false positives due
to chance alone or arose from natural genetic and/or physiologic variations.
PMID- 10674218
TI - Structure elucidation of glycoprotein glycans and of polysaccharides by NMR
spectroscopy.
AB - The applicability of 1H-NMR spectroscopy for the determination of the primary and
tertiary structure of carbohydrate-containing molecules is demonstrated. For
classes of known compounds the characterization can be based on chemical shifts
observed in 1D NMR spectra with or without the aid of a computer database. For
more complex structure determinations 2D NMR techniques are required. Here the
application of 2D NMR is demonstrated for the primary structure determination of
two bacterial exopolysaccharides, for the spatial structure determination of a
disaccharide and a glycoprotein hormone.
PMID- 10674219
TI - Structure/function studies of anticoagulant sulphated polysaccharides using NMR.
AB - Sulphated polysaccharides have many biological functions, which depend on binding
of highly specific carbohydrate structures to proteins. NMR spectroscopy is a
technique capable of detailed structural elucidation of these polysaccharides,
and can be used in applications ranging from routine analysis to research into
covalent and conformational aspects of polysaccharide structure. This technique
can be used to characterise sequence variations in heparin samples. The NMR
determined solution conformation of heparin has been used to predict binding
sites on the surface of heparin-binding proteins. Sulphation patterns for
dermatan sulphates of marine invertebrates have been determined. Their
anticoagulant effects depend on an exact pattern of sulphate substitution. A
small alteration in dermatan sulphate structure, from 4-O-sulphated to 6-O
sulphated galactosamine, leads to almost complete loss of anticoagulant activity
in spite of an overall high level of sulphation. A fucosylated chondroitin
sulphate isolated from sea cucumber has anticoagulant and antithrombotic activity
depending on its sulphated fucose branches. The anticoagulant activity of algal
fucans has been compared with that of regular, linear sulphated fucans from
marine echinoderms; again high activity appears to correlate with the presence of
sulphated fucose branches.
PMID- 10674220
TI - Diffusion in Pseudomonas aeruginosa biofilms: a pulsed field gradient NMR study.
AB - A Pseudomonas aeruginosa biofilm is studied with pulsed field gradient echo
nuclear magnetic resonance. Although not all spectral components are assigned
yet, the experimental results show that a biofilm consists of components with
very different diffusion coefficients. The various biofilm components that give
motionally narrowed 1H NMR signals, can be grouped into five classes with
diffusion coefficients, ranging from 2 x 10(-9) to 1 x 10(-13) m2 s-1.
Investigation of the diffusion behavior of water in the biofilm shows three
fractions with different diffusion coefficients. Besides the highly mobile bulk
water at least two other fractions with much lower diffusion coefficients are
detected. It is shown that one of the fractions with the low diffusion
coefficient probably arises from intracellular water. Also for another component
of the biofilm, glycerol, three fractions with diffusion coefficients that differ
more than a factor ten are detected. Also a group of signals exists which result
from practically immobile components.
PMID- 10674221
TI - [Partial non-convulsive status epilepsy in multiple sclerosis].
AB - This report describes the observations of two patients with a several years'
history of multiple sclerosis who presented sudden neurologic impairment. The
symptomatology was suggestive of a non-convulsive partial status epilepsy. The
clinical presentation was a paroxysmal dysphasic phenomenon in the first case
without any consciousness impairment, associated with slight right hemiparesis.
Electroencephalographic investigations revealed asymmetrical patterns, left-sided
slow waves and periodic lateralized epileptiform discharges (PLEDs).
Antiepileptic treatments were partially effective and intravenous steroids were
needed for complete recovery. For the second patient, clinical presentation was
acute psychiatric symptoms with disorientation, alternating manic symptomatology
and mutism. Electroencephalography showed left fronto-central rhythmic continuous
slow wave and spike wave activity. Intravenous antiepileptic treatment quickly
improved the symptomatology. These observations draw attention to the fact that
an epileptic cause should not be ruled out when a patient with multiple sclerosis
presents sudden neurologic or psychiatric impairment. An early diagnosis allows
immediate antiepileptic treatment. Intravenous steroids can be added to stop
seizures.
PMID- 10674222
TI - [Determination of language dominance using EEG spectral analysis versus the Wada
test in temporal epilepsy (right-handed subjects)].
AB - Spectral analysis of the EEG alpha rhythm was studied in nine temporal epileptic
right-handed patients in order to predict localization of the speech area. We
studied the variation of the spectral power of the alpha rhythm during an
activation paradigm previously validated in normal right-handed subjects.
Significant alpha power decreases in the left hemisphere during writing with the
right hand (as compared to resting) and/or significant alpha power decreases in
the right hemisphere during left-hand recognition and classification of cardboard
objects (as compared to resting) were considered as consistent with left
hemisphere dominance for language. The results of EEG spectral analysis were
compared with those of the Wada test. The left hemisphere was dominant for
language according to the Wada test in eight subjects and the right hemisphere in
one subject. Six patients had a significant alpha power reduction in the
hemisphere concerned during lateralized cognitive tasks, consistent with language
localization in the left hemisphere according to the Wada test. The three
remaining patients had no significant EEG spectral power variations. A
significant decrease of alpha power in the active hemisphere during cerebral
activation seems statistically related to left-hemispheric dominance for language
in right-handed subjects (hemispheric specialization). However, the localization
of the speech area using this electrophysiological method does not appear
clinically relevant for a case-by-case decision in individual patients.
PMID- 10674223
TI - Acetylcholine receptor activation enhances NMDA-mediated responses in the rat
neostriatum.
AB - The influence of acetylcholine (ACh) upon N-methyl-D-aspartate (NMDA) receptor
activation of neostriatal neurons is unknown. In the present study, we used both
in vitro intracellular and in vivo electroencephalographic recordings in rats to
examine this question. In vitro, iontophoretic application of carbachol, a
cholinergic receptor agonist, significantly increased the NMDA-mediated response
of neostriatal projection neurons. Carbachol alone had mild excitatory effects.
In vivo, intrastriatal NMDA produced focal epileptiform activity restricted to
the neostriatum. NMDA applied in conjunction with carbachol produced
significantly greater epileptiform activity which propagated to the neocortex.
These results suggest that ACh and NMDA receptor co-activation leads to
potentiation of the neuronal responses both at the site of the interaction and at
the endpoint of the cortico-striato-cortical circuit.
PMID- 10674224
TI - [Pseudo-paralysis of the brachial biceps in obstetrical brachial plexus lesions
(OBPL):concerning the "overly optimistic" EMG in OBPL].
AB - In birth palsy of the brachial plexus, the mixed interference pattern recorded
for the brachial biceps on the electromyogram often conflicts with the muscle's
inability to flex the elbow. We report our observations of a six-month-old infant
who presented paralysis of the upper and medial elements of the brachial plexus,
in whom we demonstrated early biceps-triceps co-contractions, which may explain
this discrepancy and 'pseudo-paralysis' of the biceps. We analyse and discuss the
practical consequences of these findings, and notably the possible therapeutic
use of triceps-to-biceps surgical transposition.
PMID- 10674225
TI - [Olfactory lateralization in humans: a review of the literature].
AB - In the field of human perception, the chemical senses (taste and smell) have
received little attention from neuroscience research when compared with auditory,
visual and tactile senses. In the case of olfaction, it would appear that the
publications over the last few years have been trying to overcome this lack of
research. Many investigations have been carried out on lateralization, mainly in
relation to specific pathologies (i.e., epilepsy, split-brain, lobotomy, etc.),
while there have been few studies of healthy subjects. The results are often
contradictory due particularly to special features of the olfactory system.
However, consensus is emerging concerning, first, the fact that if both
hemispheres are involved in the olfactory process, it is probable that one is
more dominant than the other (many studies have revealed a greater impact on the
right hemisphere in the treatment of olfactory information, but the dominance has
not been clearly established). Second, the simple detection process would appear
not to be lateralized whereas the higher-order olfactory tasks which involve
memory processes and lexical aspects could be. The exact conditions governing
lateralization still require more clarification by systematically taking into
consideration the characteristics of the individual subjects, as well as those of
the odorant stimuli and the test conditions. Finally, currently available
techniques used in neurosciences and particularly cerebral imagery will
contribute to a better understanding of the complexity of cerebral asymmetry in
olfaction.
PMID- 10674226
TI - A multi-center trial of the effects of oral nutritional supplementation in
critically ill older inpatients. GAGE Group. Groupe Aquitain Geriatrique
d'Evaluation.
AB - The purpose of this study was to assess the effect of nutritional supplementation
on dietary intake and on pressure ulcer development in critically ill older
patients. The multi-center trial involved 19 wards stratified according to
specialty and recruitment for critically ill older patients; 9 wards were
randomly selected for nutritional intervention (nutritional intervention group),
consisting of the daily distribution of two oral supplements, with each
supplement containg 200 kcal, for 15 d. Pressure ulcer incidence was
prospectively recorded for grades I (erythema), II (superficial broken skin), and
III (subcutaneous lesion) for 15 d. Nutritional intake was monitored by using
estimates in units of quarters validated by comparison with weight measurement.
There were 672 subjects older than 65 y, and 295 were in the nutritional
intervention group versus 377 in the control group. The patients were similar for
age, sex ratio, and C-reactive protein. In comparison with the control group, the
nutritional intervention group included more patients with stroke, heart failure,
and dyspnea and fewer with antecedent falls, delirium, lower limb fractures, and
digestive disease. The nutritional intervention group had a lower risk of
pressure ulcers according to the Norton score but was less dependent (Kuntzman
score) and had a lower serum albumin level. During the trial, energy and protein
intakes were higher in the nutritional intervention group (day 2: 1081 +/- 595
kcal versus 957 +/- 530 kcal, P = 0.006; 45.9 +/- 27.8 g protein versus 38.3 +/-
23.8 g protein in the control group, P < 0.001). At 15 d, the cumulative
incidence of pressure ulcers was 40.6% in the nutritional intervention group
versus 47.2% in the control group. The proportion of grade I cases relative to
the total number of cases was 90%. Multivariate analysis, taking into account all
diagnoses, potential risk factors, and the intra-ward correlation, indicated that
the independent risk factors of developing a pressure ulcer during this period
were: serum albumin level at baseline, for 1 g/L decrease: 1.05 (95% confidence
interval: 1.02 to 1.07, P < 0.001); Kuntzmann score at baseline, for 1-point
increase: 1.22 (0.32 to 4.58, P = 0.003); lower limb fracture: 2.68 (1.75 to
4.11, P < 0.001); Norton score < 10 versus > 14: 1.28 (1.01 to 1.62, P = 0.04);
and belonging to the control group: 1.57 (1.03 to 2.38, P = 0.04). In conclusion,
it was possible to increase the dietary intake of critically ill elderly subjects
by systematic use of oral supplements. This intervention was associated with a
decreased risk of pressure ulcer incidence.
PMID- 10674227
TI - Influence of the 13C-enrichment of the habitual diet on a 13CO2 breath test used
as an index of liver glycogen oxidation: a validation study in western Europe and
Africa.
AB - A diet containing naturally 13C-enriched carbohydrate combined with a 13CO2
breath-test analysis can be used to monitor liver glycogen oxidation in persons
used to a diet low in 13C, e.g., the Western European diet. In this study, we
evaluated this test principle further by changing the way we label the glycogen
pool. The 13C enrichment of exhaled CO2 was studied in two groups, one in Europe
and one in Africa. The European group (n = 12) was accustomed to a diet low in
13C, and they went on a 13C-enriched study diet to identify liver glycogen. The
African group (n = 6) was accustomed to a diet naturally high in 13C, and they
went on a diet low in 13C. The basal 13C abundance in exhaled CO2 was higher in
the African group (1.0879 At%; atmospheric 1.1 atom percent) than in the European
group (1.0821 At%). During the study period, the parameters for liver glycogen
oxidation--the 13CO2 enrichment plateau, the plateau duration, and the return to
baseline time--did not differ between groups. The abundance of 13CO2 in exhaled
CO2 over time in the two groups was similar but inverse. This study confirms the
use of a 13CO2 breath test to monitor liver glycogen oxidation and demonstrates
how to use such a test in persons accustomed to a diet high in 13C.
PMID- 10674228
TI - Effects of eicosapentaenoic acid intake on plasma fibrinolytic and coagulation
activity by using physical load in the young.
AB - To assess the effect of eicosapentaenoic acid (EPA) intake on fibrinolysis and
coagulation, 30 male subjects, approximately 19-23 y old, were examined for
plasma fibrinolytic and coagulation activity by using a bicycle ergometer load
(90 W, 20 min) before and after EPA intake of 1.125 g/d for 2 wk. Because of the
EPA intake, the fibrinolytic activity was promoted, the plasmin-alpha 2
plasmininhibitor complex (PIC) level was decreased by 16.7%, and the thrombin
antithrombin III complex (TAT) level was increased by 75.4%; conversely, the D
dimer of the fibrin degradation peptide (D-dimer) level did not change from that
before EPA intake. By the physical load, 1 h after ingesting the load, the PIC
level was significantly decreased by 26.7%, the TAT level was significantly
increased by 51.1%, and the D-dimer level was significantly decreased by 24% in
comparison with levels before EPA intake. Thus, as determined by the load, a
small amount of daily EPA intake clearly decreased fibrinolytic activity and
increased coagulation activity. One hour after a physical load, the rate of
change of the gamma-glutamyl transpeptidase (gamma-GTP) level correlated
significantly and negatively to the rate of change in the PIC and TAT levels.
Thus, EPA intake may affect liver and kidney function. EPA intake decreased
systolic blood pressure by 5 mmHg and diastolic blood pressure by 10 mmHg.
PMID- 10674229
TI - Differential effects of amino acid and ketoacid on protein metabolism in humans.
AB - We examined the effects of insulin, amino acid (AA), and branched-chain ketoacid
(KA) availability on leucine kinetics in eight healthy volunteers (age = 22 +/- 2
y, body mass index = 24 +/- 1 kg) by using the euglycemic insulin clamp and [1
14C] leucine turnover techniques. Four experimental conditions were studied:
study I, hyperinsulinemia; study II, hyperinsulinemia with maintenance of basal
plasma AA and branched-chain KA concentrations; study III, hyperinsulinemia with
hyperaminoacidemia and basal plasma branched-chain KA concentrations; and study
IV, hyperinsulinemia plus basal plasma AA concentrations and elevated branched
chain KA levels. Basal endogenous leucine flux (ELF) averaged 1.20 +/- 0.05
(mumol.kg-1.min-1, mean +/- SE); basal leucine oxidation (LOX) was 0.25 +/- 0.01;
and basal non-oxidative leucine disposal (NOLD) was 0.95 +/- 0.04. ELF
significantly decreased in study I (0.77 +/- 0.06 mumol.kg-1.min-1, P < 0.01
versus basal). When plasma AA and branched-chain KA were either maintained at
their basal levels (study II) or increased above baseline values (studies III and
IV), ELF declined further (0.64 +/- 0.05, 0.66 +/- 0.02, and 0.66 +/- 0.03
mumol.kg-1.min-1, respectively; all Ps < 0.01 versus basal and P < 0.01 versus
study I). LOX declined in study I (0.12 +/- 0.02 mumol.kg-1.min-1, P < 0.01
versus basal) but increased significantly in studies II, III, and IV (0.31 +/-
0.04, 0.37 +/- 0.03, and 0.40 +/- 0.03 mumol.kg-1.min-1, respectively, all Ps <
0.01 versus basal, P < 0.05 study IV versus study II, and P < 0.05 study III
versus study II). NOLD declined in study I (0.65 +/- 0.05 mumol/kg.min, P < 0.01
versus basal), whereas neither the maintenance of basal plasma AA/branched-chain
KA levels (study II; 0.89 +/- 0.2 mumol.kg-1.min-1) nor the elevation of plasma
branched-chain KA concentration (study IV; 0.96 +/- 0.1 mumol.kg-1.min-1)
increased NOLD above baseline level. A stimulation of NOLD was observed only when
plasma AA levels were increased (study III; 1.23 +/- 0.03 mumol/kg.min, P < 0.01
versus basal). In conclusion, the present data do not support the concept of a
direct anabolic action of ketoanalogs but do provide additional evidence for the
pivotal role of AA availability in the stimulation of whole-body protein
synthesis.
PMID- 10674230
TI - Selenium kinetics and changes in glutathione peroxidase activities in patients
receiving long-term parenteral nutrition and effects of supplementation with
selenite.
AB - Selenium (Se) is an essential trace element in humans. Patients receiving long
term parenteral nutrition (PN) are at risk for Se deficiency. We investigated
changes in Se levels and glutathione peroxidase (GSH-Px) activity in serum and
tissue (red blood cells, RBC) in addition to urinary excretion of Se in patients
receiving long-term PN with and without Se supplementation. In patients without
Se supplementation, both Se levels and GSH-Px activity in serum decreased with
duration of PN. The serum Se levels were below the lower limits of the control
values in 19 of 33 patients (58%) who received PN for less than 1 mo. Conversely,
RBC GSH-Px activity remained at a sufficient level in 9 of 12 patients (75%) who
received PN for 3-6 mo. The RBC Se levels in all of these patients were lower
than the control levels. Urinary Se concentrations were significantly correlated
with serum Se concentrations by linear regression analysis (r = 0.707, P < 0.05).
In patients with Se supplementation, urinary Se concentrations increased
exponentially with increases in serum Se levels. These findings indicate that a
time lag precedes the decrease in levels of serum Se, RBC Se, serum GSH-Px, and
RBC GSH-Px in patients without Se supplementation and the increase in excretion
of urinary Se in patients with Se supplementation. The monitoring of not only
serum Se levels but also RBC GSH-Px activity and urinary Se levels is required
for optimal Se supplementation during long-term PN.
PMID- 10674231
TI - Work-shift period and weight change.
AB - The present study was done to determine whether weight gain was more prevalent in
workers on late shifts than in those on day shifts. A questionnaire about changes
in weight, food intake, exercise, and sleep since starting the job on the current
shift was given to day-shift and late-shift (evening and night) hospital workers.
Data were analyzed for 85 subjects, 36 of whom worked during the day shift and 49
the late shift. The late-shift group reported a mean weight gain of 4.3 kg, which
was greater than the mean weight gain of 0.9 kg for the day-shift group (P =
0.02). There were, however, no significant differences in current body mass index
(26.7 +/- 5.4 SD) between groups. There was a trend for late-shift workers to
report eating more since beginning the later shift (P = 0.06). When combined with
those reporting exercising less (P = NS), this trend became significant (P =
0.04). Late-shift workers reported eating fewer meals (1.9 +/- 0.9 SD) than the
day-shift workers (2.5 +/- 0.9; P = 0.002). In addition, late-shift workers
reported eating the last daily meal later (mean = 22:27, or 10:27 PM) than day
shift workers (17:52 or 5:52 PM; P < 0.00005). Late-shift workers also reported
more naps (P = 0.01) and longer naps (P = 0.05) during the work week than did day
shift workers. The reported changes in eating, exercise, and sleep may contribute
to the increased weight gain of late-shift workers.
PMID- 10674232
TI - Effect of portal hypertension caused by chronic high venous pressure on small
intestinal sugar absorption.
AB - The effect of portal hypertension and chronic high venous pressure on the
absorption of the small intestine was examined by constricting the suprahepatic
and subdiaphragmatic inferior vena cava in rats. A group of rats with the
constricted suprahepatic and subdiaphragmatic inferior vena cava comprised group
1 (n = 9) and another group of rats with only laparotomy comprised group 2 (n =
9). Two months after the operation, sugar absorption and other parameters were
measured. The blood pressures of the infrahepatic inferior vena cava and the
portal vein 8 wk after the operation in group 1 were significantly higher than
those in group 2. The results of D-xylose absorption tests showed that the amount
of excreted D-xylose in urine in group 1 was significantly lower than that of
group 2, but the D-xylose everted sac test showed no significant differences
between the two groups. The glucose everted sac test showed that the amount of
glucose absorption in group 1 was significantly lower than that in group 2. These
findings suggest that chronic high venous pressure caused by constriction of
suprahepatic inferior vena cava may lead to sugar malabsorption. We conclude that
portal hypertension with high venous pressure below the diaphragm can lead to
sugar malabsorption in the intestine.
PMID- 10674233
TI - Nitric oxide synthase inhibitor attenuates inflammatory lesions in the skin of
zinc-deficient rats.
AB - Skin lesions are common manifestations of zinc deficiency in humans and animals,
but the pathogenic mechanisms have not been fully clarified. In the present
study, a nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L
NAME), was given to zinc-deficient (ZD) rats to see whether it prevents or delays
the occurrence of skin lesions. Weanling male rats were given free access to a ZD
diet (2 mg zinc/kg) for 4 wk to induce zinc deficiency. Control rats, including
pair-fed (PF) and ad libitum (AL) groups, were given a diet supplemented with
zinc (50.8 mg zinc/kg. L-NAME (0.3 g/L in drinking water) was given to some ZD
rats for 3 wk, starting at the second week of their ZD dieting. Dermatitis of the
extremities, balanitis, stomatitis, and alopecia appeared in ZD but not in AL and
PF rats. Administration of L-NAME significantly reduced the frequency of
cutaneous and mucocutaneous inflammatory lesions but did not prevent alopecia in
the ZD rats. Reverse transcription polymerase chain reaction showed that
inducible nitric oxide synthase mRNA was expressed in the paw skin of ZD but not
of AL and PF rats. Evaluation of skin microvascular permeability by the Evans
blue leakage technique indicated that L-NAME administration significantly
attenuated extravasation of Evans blue in the paw skin of ZD rats. Furthermore,
stains positive for terminal deoxynucleotidyl transferase-mediated dUTP-biotin
nick end labeling were condensed and diffusely distributed over the epidermis,
dermis, and subcutaneous tissue of paws in ZD rats. ZD rats had intense cell
infiltration and parakeratosis in the paw skin. L-NAME administration effectively
prevented these morphologic changes. These results demonstrate that nitric oxide
synthase inhibitor ameliorates inflammatory lesions of the skin in ZD rats.
PMID- 10674234
TI - Postprandial resynthesis of myofibrillar proteins is translationally rather than
transcriptionally regulated in human skeletal muscle.
AB - Feeding stimulates protein synthesis in skeletal muscles, although the regulatory
mechanisms are incompletely understood. The aim of this study was to determine
whether this could be detected at the gene transcription level for postprandial
stimulation of the synthesis of muscle proteins. Healthy male volunteers were
investigated after an overnight fast. Open muscle biopsies were performed in the
starved state and 3 h after meal intake, consisting of 0.15 gN/kg, 12 kcal/kg.
Blood samples were drawn every 15 to 30 min for 5 h. Myosin mRNA and insulin
growth factor-I (IGF-I) mRNA were measured by solution hybridization assay in
homogenized muscle specimens. After food intake, plasma glucose concentrations
increased from 5.0 +/- 0.1 to 7.3 +/- 0.3 (P < or = 0.001), and insulin
concentration rose from 3.8 +/- 0.5 mU/L before to 75.3 +/- 11.4 15 min after the
meal (P < or = 0.001). Plasma concentration of free fatty acids declined after
food intake (P < or = 0.001). Plasma concentrations of amino acids increased from
basal values (2864 +/- 128 microM) to 4419 +/- 262 microM (P < or = 0.05) 90 min
after meal ingestion. Myosin mRNA concentration in the biopsied muscle tissue was
higher during starvation and was reduced by 20% after food intake: 10.8 +/- 1.3
amol mRNA/microgram DNA in the starved state and 8.5 +/- 1.3 amol mRNA/microgram
DNA after food intake (P < or = 0.05). Feeding did not alter IGF-I mRNA
concentrations in muscle: 0.51 +/- 0.05 and 0.55 +/- 0.06 amol/microgram DNA in
the starved and fed state, respectively (P < or = 0.48). Improved protein balance
by stimulation of protein synthesis has been related to increased plasma amino
acids. Interestingly, in the short term, this was not related to increases in
gene transcription of either myofibrillar proteins (myosin) or muscle IGF-I.
Thus, postprandial stimulation of protein synthesis appears not to be regulated
by increased gene transcription but by increased translation using the increased
concentrations of amino acids. In contrast, as far as the 2X myosin mRNA level is
concerned, this is enhanced during starvation, which facilitates rapid recovery
once the availability of substrate is resumed.
PMID- 10674235
TI - Does jejunal feeding with a polymeric immune-enhancing formula increase
pancreatic exocrine output as compared with TPN? A case report.
AB - This case report compares the pancreatic output with different feeding regimes in
a patient who underwent a partial pancreatectomy for carcinoma of the ampulla of
Vater. A postoperative secretin stimulation test demonstrated significant
pancreatic reserve. There was no difference in pancreatic exocrine secretion when
the patient was fed jejunally with a polymeric immune-enhancing formula or
supported with two different formulations of total parenteral nutrition. This
result suggests that jejunal infusion of a polymeric immune-enhancing formula may
be safe to administer in patients with acute pancreatitis.
PMID- 10674236
TI - Assessment of protein energy malnutrition in older persons, part I: History,
examination, body composition, and screening tools.
AB - Protein-energy malnutrition is a prevalent problem in older persons. Its relation
to increased morbidity and mortality has been well documented. Early recognition
of malnutrition allows for a timely intervention. A large proportion of chronic
diseases affecting older persons can be either prevented or significantly
improved by improving nutrition, which underscores the importance of developing a
screening system that can trigger a more comprehensive evaluation when indicated.
Screening for malnutrition in older persons can be difficult because of the
normal age-related changes in many of the commonly used parameters. A
comprehensive nutritional evaluation includes a complete history and physical
examination in addition to a more specific nutrition-oriented assessment.
Specific nutritional assessment includes estimating food intake, anthropometric
measurements, and evaluation of several biochemical parameters commonly affected
by changes in nutritional status. In this article, we review the commonly used
tools for nutritional assessment in older persons. The goal is to promote disease
free, active, and successful aging.
PMID- 10674237
TI - An osmotic stimulus-mediating glucagon-like peptide-1 (7-36 amide) (GLP-1)
secretion in acarbose-induced sucrose malabsorption?
PMID- 10674239
TI - Of Vikings, Apollo, serendipity, and research letters.
PMID- 10674238
TI - Dopamine in the VMN of the hypothalamus is important for diurnal distribution of
eating in obese male Zucker rats.
PMID- 10674240
TI - Effects of glutamine on immune cells.
PMID- 10674241
TI - Effect of dietary glutamate on chemotherapy-induced immunosuppression.
PMID- 10674242
TI - Glutamine-enriched enteral nutrition in multiple trauma patients.
PMID- 10674243
TI - More good news about glutamine.
PMID- 10674244
TI - Arginine and immunonutrition: a reevaluation.
PMID- 10674245
TI - Perioperative nutritional support in liver surgery.
PMID- 10674246
TI - Nutrition and Crohn's disease: a case study in ambiguity.
PMID- 10674247
TI - Nutrition in pediatric inflammatory bowel disease.
PMID- 10674248
TI - Regression to the mean.
PMID- 10674249
TI - Repair of double-lumen tube with simple and inexpensive materials.
PMID- 10674250
TI - The first PEG.
PMID- 10674251
TI - Red blood cell membrane oxidative damage and renal impairment in uremic patients
under conservative treatment.
PMID- 10674252
TI - Pregnancy in the postmenopause: how far can assisted reproductive technology be
trusted?
PMID- 10674253
TI - Bleeding risk and reproductive capacity among patients with factor XIII
deficiency: a case presentation and review of the literature.
AB - Factor XIII deficiency is an uncommon, inherited bleeding disorder that usually
manifests in infancy or early childhood, involving both boys and girls. We
present the case of a woman who had experienced two previous intracranial
bleeding events, and was treated before and during her current pregnancy with
factor XIII concentrate. Her pregnancy was successful, and she experienced an
uncomplicated vaginal delivery. To better understand the issues surrounding
bleeding, reproductive capacity, and management of factor XIII deficiency during
pregnancy, we conducted a systematic literature review using MEDLINE from 1966 to
December 1998. We also examined the bibliographic references from all articles,
and included all cases, case reports, or case series of patients with factor XIII
deficiency. We retrieved data on 117 patients from 37 articles, the majority of
which had type II deficiency. Among untreated patients with type II factor XIII
deficiency, the literature suggests an elevated mortality rate due to
uncontrolled bleeding and intracranial hemorrhage. Because of its high degree of
efficacy, the evidence supports the use of life long prophylactic therapy with at
least monthly infusions of factor XIII concentrate, including during pregnancy.
The opinion that women with type II factor XIII deficiency have inevitable
recurrent abortions, or that men are sterile, is not well substantiated. No data
were found on whether treatment alters male reproductive capacity. A policy of
universal factor XIII replacement, starting in childhood, will likely enable more
patients to attain reproductive status. The development of an international data
registry would optimally address both bleeding risk and reproductive capacity
among patients with factor XIII deficiency.
PMID- 10674254
TI - Gynecological and reproductive issues for women in space: a review.
AB - Women have been an integral part of United States space crews since the initial
flight of Dr. Sally Ride in 1983, and a total of 40 women have been selected as
U.S. astronauts. This article examines the reproductive and gynecological aspects
of selecting, training, medically certifying, and flying women in space.
Gynecological data from the astronaut selection cycles in 1991 to 1997 are
reviewed. In addition, the reproductive implications of delaying childbearing for
a career as an astronaut and the impact of new technology such as assisted
reproductive techniques are examined. The reproductive outcomes of U.S. female
astronauts after spaceflight are also presented. Because women have gained
considerable operational experience on the Shuttle and Mir, the unique
operational considerations for preflight certification, menstruation control and
hygiene, contraception, and urination are discussed. Medical and surgical
implications for women on long-duration missions to remote locations are still
evolving, and enabling technologies for health care delivery are being developed.
There has been considerable progress in the development of zero-gravity surgical
techniques, including laparoscopy, thoracoscopy, and laparotomy. The concepts of
prevention of illness, conversion of surgical conditions to medically treatable
conditions, and surgical intervention for long-duration spaceflights are explored
in detail. There currently are no operational gynecological or reproductive
constraints for women that would preclude their successful participation in the
exploration of our nearby solar system.
PMID- 10674255
TI - Obstetric implications of activated protein C resistance and factor V Leiden
mutation.
AB - An increasing number of reports have focused on activated protein C resistance
(APCR) as it has been shown not only to be the most common genetic factor
predisposing patients to thromboembolic disease but the most common identifiable
cause overall. More than 90 percent of the cases of APCR are caused by the factor
V Leiden mutation, in which a guanine to adenine substitution in the factor V
gene at nucleotide position 1691 results in a glutamine to arginine switch at
position 506. Recent studies have also pointed to evidence of an association
between APCR/factor V Leiden mutation and hypertensive disorders of pregnancy,
first and second trimester miscarriage, placental infarction, and placental
abruption.
PMID- 10674256
TI - [Role of the telophasic disc in the regulation of cytokinesis].
PMID- 10674257
TI - [Molecular study of a false outbreak of ticarcillin-resistant Pseudomonas
aeruginosa infections in a clinical hematology department].
AB - Molecular methods for bacterial strain typing are becoming available outside
teaching hospitals and large structures. Although it seems reasonable to use
conventional markers, most notably the serotype, whenever possible, the
limitations of these methods are particularly conspicuous with P. aeruginosa.
Combined use of several methods such as quantitative antibiotic susceptibility
testing and serotype determination has proved adequate for characterizing P.
aeruginosa strains in some cases. In the case of the outbreak reported herein,
this approach failed to provide high quality epidemiological data. In contrast,
pulsed field gel electrophoresis ruled out epidemic spread of a P. aeruginosa
strain in the clinical hematology department.
PMID- 10674258
TI - [Inter-laboratory reproducibility of pulsed-field electrophoresis for the study
of 12 types of Pseudomonas aeruginosa].
AB - The increasing hospital-to-hospital transmission of multiple drug-resistant
bacteria is a major concern for bacteriology laboratories involved in nosocomial
infection control. The interlaboratory reproducibility of pulsed-field gel
electrophoresis (PFGE) for Pseudomonas aeruginosa typing was evaluated by asking
four hospital laboratories (two in Lyon, one in Brest, and one in Marseille) to
study 11 P. aeruginosa isolates, some of which were epidemiologically related,
and the reference strain ATCC 27853. Two laboratories used the Genepath system,
one the Chef DR II, system, and one the Chef Mapper system, Bio-Rad,
restriction/Spe I. Profiles were read visually and by computerized comparison of
restriction band molecular weights (Taxotron, software, PAD Grimont, Pasteur
Institute, Paris, France). These two methods led to similar epidemiological
conclusions. However, centralization of the data showed poor center-to-center
reproducibility due to inadequate standardization of the procedure.
PMID- 10674259
TI - [Pneumococcus observatory data in the Rhone-Alps region. Results from 1996].
AB - Throughout 1996, 22 hospital-based laboratories in the Rhone-Alpes region of
France collected pneumococcal strains and used a standardized protocol to record
the following data; patient age and sex; type of specimen; and determination of
susceptibility to at least the following antibiotics: oxacillin 1 microgram and 5
micrograms, erythromycin (Ery), tetracycline (Tet), chloramphenicol (Chl),
rifampin (Rmp), and loracarbef. For penicillin-nonsusceptible strains (PNSSs),
which were identified based on results with oxacillin, MICs for penicillin G,
amoxicillin (Amx), and cefotaxime (Ctx) were determined using the E Test, at the
study site and agar dilution at the coordinating center. Of the 1153 strains,
65.5% were from adults and 31.8% from children; patient age was unknown in 2.7%
of cases. PNSPs (MIC > 0.06 mg/l) contributed 32.9% of strains (I: 23.3%; R:
9.6%) and were more common in children (41.1%) than in adults (28.1%). The
frequency of PNSSs varied across specimen types: 27.9% in blood cultures (305
strains), 15.6% in cerebrospinal fluid (32), 38.7% in protected bronchopulmonary
specimens (31), 31.5% in unprotected bronchopulmonary specimens (434), 50.8% in
acute otitis media (118), and 34.4% in other specimens (221). Among PNSSs,
nonsusceptibility (I + R) to other antibiotics was variable: Ery, 62.1%; Tet,
41.5%; Chl, 40.4%; Rmp, 1.1%. Corresponding figures for the overall strain
population were Ery, 33.3%; Tet, 22.7%; Chl, 22.8%; Rmp, 0.9%. In addition, 56.5%
of PNSSs exhibited multiple drug resistance. Resistance to amoxicillin (MIC > 2
mg/l) was demonstrated for only 5 strains. No strains were resistant to
loracarbef or cefotaxime. Serotypes of the 379 PNSSs were as follows: 23F, 26.6%;
14 (25.6%); 9V (18.2%), 6 (8.7%), 15 (5%), 19 (4.5%).
PMID- 10674261
TI - [Surgical antibiotic prophylaxis: point evaluation of practices].
AB - Compliance of prophylactic antimicrobial therapy (PAMT) in surgical patients with
consensus-based recommendations was evaluated at the Montfermeil Hospital Center,
France, in 1996, based on data for given days. All patients who had surgery on
the study days were included. Data on the patient, surgery, and PAMT were
collected. Practices were evaluated based on seven criteria: need for PAMT, type
of drug used, dosage, time of first administration in relation to the time the
incision was made, time of administration during surgery, administration time
schedule, and total duration. Of the 93 patients who had surgery on one of the
five study days, 59.1% received PAMT. All seven evaluation criteria were met in
68.2% of cases. Failure to adhere to the recommended time of first administration
was the most common form of noncompliance.
PMID- 10674260
TI - [Bacterial contamination of multi-dose ocular solutions. A prospective study at
the Grenoble Teaching Hospital].
AB - The bacterial contamination rate of multidose ocular solutions used by
hospitalized patients was evaluated by culturing vial dropper tips and residual
solution in vials. Bacterial colonies were counted and identified. Overall 39
(23.5%) selected vials were contaminated. Contamination rates were 17.7% (20/113)
for vials used by ophthalmology ward patients and 35.8% (19/53) for vials used by
internal medicine and gerontology patients (P < 0.02). The most commonly
identified organisms were part of the normal commensal flora. Three ophthalmology
patients were using vials contaminated with Pseudomonas aeruginosa. A significant
(P < 0.01) positive correlation was found between vial contamination rate and
duration of vial use. Vials containing an antimicrobial agent were less likely to
be contaminated than vials without antimicrobials (P < 0.01). No clinical
consequences of vial contamination were identified. However, ocular solution vial
contamination carries a risk of infection. Our data are evidence of inadequate
efficacy of preservatives present in ocular solutions. The standard practice of
using ocular solution vials for seven days in health care facilities may need to
be reappraised. Care should be taken to ensure that health care providers and
patients understand the rules for ocular solution use. Unit-dose presentations
may be preferable over multi-dose presentations for in hospital treatment.
PMID- 10674262
TI - [Multidrug resistant bacteria in a psychiatric milieu].
AB - Isolation rates of multiple-drug resistant (MDR) bacteria were evaluated
retrospectively in a psychiatric care facility. Over the six-year study period,
66 MDR bacterial strains were found. Methicillin-resistant Staphylococcus aureus
contributed half of all MDR strains and 31% of all S. aureus strains. Among
Pseudomonas aeruginosa strains, 22% were resistant to ticarcillin or imipenem,
and among Enterobacteriaceae, 4.1% were MDR strains (production of a derepressed
cephalosporinase or of an extended-spectrum beta-lactamase). Although most MDR
strains were probably acquired during hospitalizations in short-term care
facilities outside our institution, patient-to-patient transmission, either
direct or via other individuals, cannot be ruled out. These data indicate that
psychiatric care facilities should adopt the MDR strain monitoring strategies
already used in other hospitals.
PMID- 10674263
TI - [Genetic and molecular aspects of obesity: recent data].
AB - Obesity is a disease responsible for many serious complications. The sharp rise
in the prevalence of obesity in many countries is supplying a powerful drive to
basic and clinical research. Several genes responsible for monogenic murine
obesity have recently been identified. One of these genes encodes the OB protein,
or leptine, which is secreted by fat tissue and inhibits appetite by means of an
effect on the hypothalamus. In humans, obese subjects carrying a mutation of this
gene or of the leptine receptor have been identified. Several other genes
implicated in human obesity have been mapped to chromosomes 1, 11, 18, and 20.
Several transcription factors that control fat cell differentiation have been
identified, such as C/ERB alpha, beta, and delta; ADD1/SREBP1, and PPAR gamma 2.
It has been established that fat tissue can secrete many factors, including TNF
alpha, CETP, IGF beta, TGF beta, PGE2, and LPA. Mitochondrial uncoupling proteins
(UCPs) are recently characterized proteins capable of uncoupling respiration and
contributing to energy expenditures. The hypothalamic neuropeptides and their
receptors are a focus of active research. About ten of these neuropeptides have
been identified.
PMID- 10674264
TI - [Recent data from the literature on the biological and pathologic effects of
electromagnetic radiation, radio waves and stray currents].
AB - Electromagnetic radiation is present in increasing amounts in our environment,
and its potential effects on human (and animal) health has been investigated. It
remains unclear whether the risk of acute childhood leukemia is associated with
cumulative exposure to magnetic fields. An association with brain cancer and
colon cancer has been suggested in electrical company workers. The radars used by
police departments may increase the incidence of cancer. Electromagnetic
radiation may play a role in a number of disorders such as depression and memory
loss. It has been established that cell phones interfere with pacemakers only if
direct contact occurs and have no effect if held in their normal position.
Interferences have been reported between pacemakers and shop-lifting detectors.
PMID- 10674265
TI - [A brief overview of the discovery of cell mortality and immortality and of its
influence on concepts about aging and cancer].
AB - After having accomplished the miraculous performance that led us from conception
to birth, then to sexual maturity and adulthood, natural selection failed to
develop a more elementary mechanism capable of simply maintaining the results of
this process forever. This failure is aging. Because few animals age in the wild,
evolution could not give an advantage to animals with modifications due to aging.
Natural selection benefits those animals that have the highest likelihood of
effectively perpetuating their species because their vital systems have the
larger reserve capacity they need to resist and survive predators, disease,
injury, and extreme environmental conditions. Natural selection decreases after
sexual maturity has been reached because at that stage the species would not
derive additional advantages from individuals with larger physiological reserves.
A species increases its likelihood of survival by investing its resources and
energy into increasing its opportunities for fruitful reproduction rather than
into prolonging its postreproductive life span. Most animals are mortal and
undergo aging because investment of resources into keeping the body eternally
youthful does not promote species survival as much as their investment into
strategies that make reproduction more successful.
PMID- 10674266
TI - Role of ras mutation in the progression of thyroid carcinoma of follicular
epithelial origin.
AB - The histological differentiation of thyroid carcinoma is known to correlate with
prognosis. Ras oncogene mutations, which have been identified in various human
cancers, have been suspected playing an important role in carcinogenesis and
tumor progression. The purpose of this study was to clarify the mechanism of
thyroid tumor progression, focusing on ras oncogenes. We examined ras mutations
using nested polymerase chain reaction (PCR) and direct sequencing methods. The
ras oncogene product was also examined immunohistochemically. Our results
indicated that the incidence of ras mutations correlated with the histological
differentiation of thyroid cancer. Three poorly differentiated carcinomas showed
a higher rate of ras mutations than did 17 well-differentiated counterparts. Hot
spots were not identified except for a relative accumulation of the N-ras gene at
codon 61. There was a correlation between the immunoreactivity of the ras
oncogene product and ras mutation, although the immunoreactivity of ras-p21 did
not correlate with the histological differentiation. Mutation of the ras gene
seemed to be one of the important events in the progression from well
differentiated carcinoma to poorly differentiated thyroid carcinoma.
PMID- 10674267
TI - Treatment with lansoprazole also induces hypertrophy of the parietal cells of the
stomach.
AB - The aim of the present study was to investigate whether not only omeprazole but
also lansoprazole leads to hypertrophy of the parietal cells of the gastric
mucosa. We investigated the gastric mucosa of 295 patients with gastro-esophageal
reflux disease prior to therapy, after 8 weeks of treatment with 30 mg
lansoprazole/day, and after 6 and 12 months of long-term treatment with 15 or 30
mg lansoprazole, or 20 mg omeprazole/day. In a small group of 48 patients, a
follow-up examination was carried out 3 months after termination of the study.
Following acute treatment with 30 mg lansoprazole/day, 84% of the patients
revealed parietal cell hypertrophy, while under long-term treatment this figure
rose to 89%. The grade of the parietal cell hypertrophy increased continuously
under long-term treatment. With regard to the incidence and grading of parietal
cell hypertrophy, no significant differences were found among the three groups
receiving long-term treatment. Three months after termination of treatment with
these proton-pump inhibitors, the hypertrophy of the parietal cells had largely
disappeared again. This study shows that hypertrophy of the parietal cells in the
gastric mucosa occurs not only under treatment with omeprazole, but also under
therapy with lansoprazole, and is reversible when the proton pump inhibitors are
discontinued.
PMID- 10674268
TI - Expression of the plasminogen activator system and the inhibitors PAI-1 and PAI-2
in posttraumatic lesions of the CNS and brain injuries following dramatic
circulatory arrests: an immunohistochemical study.
AB - Plasminogen activators as inducible extracellular serine proteases are involved
in a variety of processes, such as the degradation of brain structures. In
regions of brain degradation, an increase in the expression of genes encoding
cytokines and proteinases has recently been demonstrated. We tested the
hypothesis, whether the plasminogen activator system as well as the plasminogen
activator inhibitors are expressed and possibly involved in a proteolytic cascade
that breaks down the extracellular matrix as a result of ischemic or
posttraumatic brain destructions. To study this supposition, we investigated
immunohistochemically the expression of tPA, uPA and its receptor, the
plasminogen activator inhibitors PAI-1 and PAI-2, tetranectin as well as the
laminin breakdown as an event of secondary brain injury. Brain tissue from 21
autopsy cases with severe brain injuries, material from 14 ischemic infarcts and
11 controls with acute hypoxia were used. All components of the plasminogen
activator system studied were over-expressed immunohistochemically in reactive
astrocytes, microglia and endothelial cells around the lesion zone. Tetranectin
showed an analogous distribution to the plasminogen activator system. A reduced
immunoreactivity of laminin within the identical region of destruction was
detected concomitant with laminin remnants in perivascular macrophages, so that a
remarkable role of the plasmin cascade in the degradation of extracellular matrix
proteins in the brain is taken into consideration.
PMID- 10674269
TI - Time-dependent changes of decorin in the infarct zone after experimentally
induced myocardial infarction in rats: comparison with biglycan.
AB - Decorin, a small dermatan sulphate proteoglycan, has been postulated to interact
with other components of the extracellular matrix. We examined time-dependent
changes of decorin in the infarct zone after experimentally induced myocardial
infarction in rats by Northern blotting, in situ hybridization, and
immunohistochemistry. The expression of decorin mRNA was compared to that of
biglycan mRNA. Northern blotting demonstrated that the decorin mRNA expression
was not increased in the infarct zone on day 2, while increased biglycan mRNA was
observed at that time (average 3.1-fold increase). Decorin mRNA expression was
increased on day 7, and reached a peak (average 2.2-fold increase) around day 14.
Biglycan mRNA expression also reached a peak level around day 14 (average 13.3
fold increase). In situ hybridization revealed that mRNA signals for decorin did
not appear in the infarct zone on day 2, while biglycan mRNA signals were
observed. Decorin mRNA signals were observed in spindle-shaped mesenchymal cells
in the infarct peripheral zone on day 7. The decorin mRNA signals appeared later
than those of biglycan. Immunopositive staining for decorin was observed in the
infarct zone on day 7. The present results demonstrated a time-dependent increase
in decorin mRNA expression in mesenchymal cells in the infarct zone in rats.
Decorin mRNA appeared later and was increased to a lower extent in the infarct
zone than biglycan mRNA.
PMID- 10674270
TI - Importance of estrogen receptors for the behavior of invasive micropapillary
carcinoma of the breast. Review of 68 cases with follow-up of 54.
AB - The aggressiveness of invasive micropapillary carcinomas of the breast (MPCa) is
still controversially discussed. Therefore, we investigated a total of 68 cases
and studied the evolution of 54. MPCa were frequently well-differentiated cancers
with the following positivities for immunohistochemistry: 74.5% estrogen receptor
(ER+), 46.3% progesterone receptor (PR+), 66% Bcl2+, and 36.4% C-erbB-2+.
However, in 90.5% of the cases lymph nodes were involved at diagnosis, and 70.6%
of T1 tumors showed wide metastatic spread. After a mean follow-up of 52.6
months, 55.6% of the patients were disease free (DF), 7.4% had disseminated
disease and 37% had died. Univariate analysis showed significant differences.
Thus, the DF group of patients included 90% of those having tumors with an
associated colloid pattern, 73.3% of the ER positive tumors, none of the C-erbB-2
positive tumors, and 100% of the tumors with no axillary metastasis, 77.8% of
those with metastasis to up to 3 nodes, and 47.2% of those metastasizing to 4 or
more nodes. However, using Cox's regression model for survival analysis, ER was
the only factor associated with duration of survival (p = 0.0175). In conclusion,
although long-term survival in MPCa is determined by involvement of lymph nodes,
as is the case in any other breast cancer type, their short-term evolution is
influenced by other factors, mostly by estrogen receptors.
PMID- 10674271
TI - RB protein expression in human endometrial carcinomas--an immunohistochemical
study.
AB - The aim of the current study was to investigate the immunohistochemical
expression of the retinoblastoma protein (pRB) in formalin-fixed, paraffin
embedded specimens obtained from 62 patients suffering from endometrial cancer.
The avidin-biotin-peroxidase detection system with microwave pretreatment and the
mouse anti-human NCL-RB1 monoclonal antibody were used. Heterogeneous nuclear
immunostaining for the pRB was generally observed in the glandular cells in 59
out of 62 (95%) endometrial carcinomas, while stromal components were unreactive.
In one case of stage Ic endometrioid adenocarcinoma, a small percentage of
glandular cells (5%) stained positively with the anti-RB antibody, while two
other tumors (stage IIa adenosquamous carcinoma and stage IIIa endometrioid
adenocarcinoma) were pRB negative. In the cases with concomitant hyperplastic and
neoplastic endometrial lesions, pRB immunoreaction was heterogeneous in the
hyperplastic endometrial cells and in the adjacent neoplastic endometrium.
Moreover, eight cases of endometrial carcinoma harboring K-ras codon 12 gene
point mutation overexpressed pRB (more than 80% of glandular endometrial cells
were positive) immunohistochemically, while none of three pRB negative slides had
a K-ras gene alteration. Our data support the view that the pRB is expressed in
most of the human endometrial neoplasms, but the lack of pRB immunoreactivity may
correspond with the retinoblastoma gene rearrangements in a subset of advanced
endometrial carcinomas.
PMID- 10674272
TI - Concentration of iron and distribution of iron and transferrin after experimental
iron overload in rat tissues in vivo: study of the liver, the spleen, the central
nervous system and other organs.
AB - The purpose of this study was to estimate the iron concentration in the liver,
spleen and brain of control rats and rats overloaded with iron and to determine
the distribution of iron and of transferrin (TF). Iron was administered to Wistar
rats by food supplemented with 3% carbonyl iron for 3 months, or
intraperitoneally, or intraveneously as iron polymaltose for 4 months (total
administered dose: 300 or 350 mg/rat, respectively). Iron concentration was
estimated by atomic absorption spectrophotometry and iron- and TF-distribution
histochemically and immunohistochemically, respectively. In control rats the
organ with the highest iron content was the spleen, followed by the liver and
brain. After iron loading the increase of iron in the liver was greater than that
of the spleen; iron concentration in the brain did not change significantly.
Distribution of iron in the liver was in Kupffer cells throughout the lobule and
in hepatocytes at its periphery. No difference in the number of positive cells or
staining intensity for TF was observed between control rats and iron overloaded
animals in the liver or central nervous system (CNS); the spleen was negative for
TF. Distribution of TF in the liver showed a centrilobular localisation in
hepatocytes. TF reaction in the brain occurred in oligodendrocytes, vessel walls,
choroid plexus epithelial cells and some neurons. In conclusion, experimental
iron overload in rats leads to iron uptake mainly by reticuloendothelial (RE)
cells and hepatocytes, indicating that hepatocytes are of particular importance
for iron metabolism. Iron uptake by the brain was not significant, probably
because the brain is protected against iron overload. Iron overload did not
influence location and quantity of TF in the liver and CNS, whereas the
visualisation of iron and TF did not coincide. This indicates that TF may have
other functions beyond iron transport.
PMID- 10674273
TI - Sustentacular cells in sporadic paraganglioma-like medullary thyroid carcinoma:
report of a case with diagnostic and histogenetic considerations.
AB - Sustentacular cells (SCs) are glial supporting cells of the fetal, adult normal,
and neoplastic extra and adrenal human chromaffin cell lineage. SCs have also
been identified in some cases of medullary thyroid carcinoma (MTC), raising both
diagnostic and histogenetic problems. We report a rare case of a sporadic
paraganglioma-like variant of MTC showing numerous S-100 protein and glial
fibrillar acid protein (GFAP) positive SCs encircling neoplastic cells in a
nesting (Zellballen) pattern similar to that observed in paragangliomas or
pheochromocytomas. Although stromal amyloid deposits were only focally detected,
diagnosis was immunohistochemically confirmed by immunoreactivity of the
neoplastic cells for cytokeratin, CEA, calcitonin, chromogranin A, neuron
specific-enolase, and synapthopysin. As for the histogenesis of SCs, if we assume
that MTC is a neural crest-derived tumor, it is likely that these cells reflect
the ability of the common precursor cell to differentiate towards a sustentacular
type glial cell lineage in addition to the typical neuroendocrine one. This
viewpoint is supported by the evidence that rare cases of MTC may contain
neoplastic or supporting cells showing a multidirectional differentiation
(usually neuroendocrine and melanocytic) that recapitulates the different cell
lineages arising from the developing neural crests.
PMID- 10674275
TI - Spindle cell rhabdomyosarcoma in adults. A case report and literature review.
AB - Spindle cell rhabdomyosarcoma, a recently described variant of embryonal
rhabdomyosarcoma in children, carries a favorable prognosis when compared with
other types of rhabdomyosarcoma. This tumor is rare in adults, and only four
cases have been documented previously. The clinicopathological study of such a
case occurring in the retroperitoneal space of a 53-year-old man is herein
reported. The patient died of uncontrolled local recurrence and hepatic
metastases seven months after diagnosis. Based on the analysis of the data of the
five cases reported, including the present one, it can be stated that spindle
cell rhabdomyosarcoma in adults is not associated with the favorable outcome
observed in the pediatric population.
PMID- 10674274
TI - Foreign-body reaction to silastic burr-hole covers with seroma formation: case
report and review of the literature.
AB - Because silastic material is one of the most commonly used biomaterials in modern
medicine, the biocompatibility of these implants is still a source of long
standing controversy. Though several studies have established silastic material
as biologically inert, numerous authors have repeatedly described characteristic
pathological tissue responses to silicone and its elastomeres. We report a case
of foreign-body reaction to silastic burr-hole cover with successive formation of
a seroma following resection of an olfactory groove meningioma. Within 30 days
postoperatively, the patient developed a marked bulge in the glabbelar region.
Histopathological examination revealed a seroma-like lesion obviously caused by a
chronic inflammatory allergic reaction to the silastic burr-hole cover. Although
the silicone-induced tissue damage clinically shows a wide variability and a
conclusive model of pathogenesis is presently not available, the
histopathological findings in some patients, in the form of granulomatous lesions
and inflammatory cell response, might partly be due to an immunological reaction.
Such a reaction has been previously described both clinically and experimentally,
as detected in our patient. In addition, a review of the literature is given.
PMID- 10674276
TI - Interaction of desipramine with steroid hormones on experimental anxiety.
AB - The present study analyzes if estradiol benzoate and/or progesterone interact
with desmethylimipramine (DMI) to diminish experimental anxiety. The animal model
of anxiety used was the conditioned defensive burying test. Dose response curves
for DMI (0.625, 1.25 and 2.5 mg/kg, every 24 h, during 21 days), estradiol
benzoate (0.5, 1.0, 2.0 and 4.0 micrograms/rat, 48 h) and progesterone (0.5, 1.0
and 2.0 mg/rat, -4 h) were made in ovariectomized rats. DMI per se decreased dose
dependently the cumulative burying time, an effect considered as anxiolytic-like.
Progesterone produced a decrease in burying at the highest dose, while estradiol
benzoate had no effect on defensive burying. Both, progesterone (0.5 mg/rat) and
estradiol benzoate (4.0 micrograms/rat) were able to decrease the cumulative
burying behavior when injected with a subthreshold dose of DMI (1.25 mg/kg). In
addition, the effect of DMI (1.25 mg/kg) plus the combination of estradiol
benzoate and progesterone, sequentially administered (48 h and 4 h before the
tests, respectively), also produced a synergistic decrease in burying behavior.
In general, the treatments produced no changes in burying behavior latency,
neither in spontaneous ambulation or in nociception. It is concluded that DMI
synergizes its anxiolytic-like effect when administered with estradiol alone or
in combination with progesterone. Present data provide experimental evidence
suggesting an interaction between hormones and antidepressants. Results are
discussed on the basis of the interaction between steroids and serotonergic or
GABAergic receptors.
PMID- 10674277
TI - Immune activation in the early puerperium is related to postpartum anxiety and
depressive symptoms.
AB - The pathophysiology of the postpartum blues, common transient mood disorders in
the first week postpartum, has remained elusive. Recently, however, it has been
shown that depression and anxiety disorders are accompanied by activation of the
inflammatory response system (IRS). This study was developed to determine whether
the postnatal blues is associated with IRS activation. Serum concentrations of
interleukin-6 (IL-6), IL-6 receptor (IL-6R), gp130 (the IL-6 signaling protein),
IL-1R antagonist (IL-1RA) and leukemia inhibitory factor receptor (LIFR) were
assayed in 22 nonpregnant women and in 91 pregnant women before delivery and 1
and 3 days after delivery. On each occasion the parturient women completed the
State version of the Spielberger State-Trait-Anxiety-Inventory (STAI) and the
Zung Depression Rating Scale (ZDS). Serum IL-6, IL-1RA and LIFR were
significantly higher in pregnant women at the end of term than in nonpregnant
women.
PMID- 10674278
TI - Neurohormonal responses to D-fenfluramine in healthy elderly subjects. A placebo
controlled study.
AB - Considering age-related changes in serotonin (5HT) function, we examined
normative data of prolactin (PRL) and cortisol (CORT) responses to D-fenfluramine
(D-FEN) in healthy elderly subjects. Twenty-three healthy male and female
volunteers aged 60-86 participated in a single-blind, placebo-controlled, fixed
order, crossover-design challenge test. Two baseline PRL and CORT values and the
responses of these hormones to 30 mg of oral D-FEN and placebo over a 4 h period
were measured on two separate sessions. PRL and CORT responses were significantly
greater following D-FEN than after placebo. Peak PRL responses (maximum change
from baseline following D-FEN) were relatively robust compared to peak CORT
responses. Peak PRL concentration was positively correlated with plasma D-nor-FEN
concentration. Gender and aging had no effect on hormonal responses in the
elderly. Although the weight adjusted dose used in this study was higher than the
therapeutic dose of D-FEN, PRL responses were modest and only two participants
experienced side effects. D-FEN is a safe serotonergic probe and PRL responsivity
to D-FEN is a reliable index of central 5HT function in the elderly. An age
related decline in serotonergic function must be considered in determining the
dose requirement for maximal hormonal responses to D-FEN challenge tests in the
elderly.
PMID- 10674279
TI - Dexamethasone suppression of corticosteroid secretion: evaluation of the site of
action by receptor measures and functional studies.
AB - A dose of dexamethasone was determined in rats (50 micrograms/kg s.c.) that
suppressed the corticosterone response to restraint stress by 80%. Corticosteroid
receptor occupancy estimates found that the 50 micrograms/kg s.c. dose of
dexamethasone had no significant effect on available glucocorticoid receptor (GR)
or mineralocorticoid receptor (MR) binding in brain regions (hypothalamus,
hippocampus and cortex); on the other hand dexamethasone produced a selective and
significant decrease in available GR in peripheral tissues (pituitary and
spleen). Functional studies showed that the 50 micrograms/kg s.c. dose of
dexamethasone completely blocked the effects of corticotropin-releasing hormone
(CRH; 0.3-3.0 micrograms/kg i.p.) on corticosterone secretion, but did not
inhibit the corticosterone response to an adrenocorticotropin hormone (ACTH; 2.5
I.U./kg i.p.) challenge. These studies indicate that this dose of dexamethasone
exerts its inhibitory effects on the HPA axis primarily by acting at GR in the
pituitary. The plasma dexamethasone levels produced by this dose of dexamethasone
are similar to those present in humans the afternoon after an oral dexamethasone
suppression test (DST), a time at which many depressed patients escape from
dexamethasone suppression. These results support and extend other studies which
suggest that the DST provides a direct test of the effects of increased GR
activation in the pituitary on ACTH and cortisol secretion.
PMID- 10674280
TI - Hormonal markers of stress response following interruption of selective serotonin
reuptake inhibitor treatment.
AB - Depressive illness is associated with loss of the usual regulation of stress
responsive hormonal and neurotransmitter systems, and antidepressants have
intrinsic effects reducing the activity of these systems. Abrupt interruption of
treatment with some antidepressants has been associated with a self-limited
syndrome of physical and psychological symptoms distinct from relapse, of which
drug half-life appears to be the major determinant. We hypothesized that
reactivation of stress-response systems could play a role in this syndrome and
studied the effects of treatment interruption in patients successfully treated
with the antidepressant fluoxetine, paroxetine or sertraline. During placebo
substitution, interruption of paroxetine was associated with statistically
significant increases in plasma IGF-1 and heart rate. These data suggest that
some activation of physiologic stress-responses may accompany symptom increases
during treatment interruption of shorter half-life agents.
PMID- 10674281
TI - Muscarinic cholinergic mediation of the GH response to gamma-hydroxybutyric acid:
neuroendocrine evidence in normal and parkinsonian subjects.
AB - We have recently reported that parkinsonian patients show a significant GH
response to gamma-hydroxybutyric acid (GHB), but not to gamma-aminobutyric acid
(GABA)-ergic drug administration. In order to establish whether muscarinic
cholinergic receptors mediate the GH secretion induced by GHB, normal men and
parkinsonian patients were tested with GHB both in the absence and in the
presence of the anticholinergic agent, pirenzepine. Both normal controls and
parkinsonian patients showed a significant serum GH rise in response to GHB (25
mg/kg body weight p.o.) even though a slightly, but significantly lower response
was observed in parkinsonian patients. Pretreatment with pirenzepine (100 mg p.o.
2 h before GHB) completely suppressed the GHB-induced GH release in both normal
controls and parkinsonian patients. These data indicate that a cholinergic
mechanism mediates the GH response to GHB in normal men. In addition the data
indicate that this pathway is preserved in the parkinsonian brain.
PMID- 10674282
TI - Neuroendocrine response to film-induced sexual arousal in men and women.
AB - The psychoneuroendocrine responses to sexual arousal have not been clearly
established in humans. However, we have demonstrated previously that masturbation
induced orgasm stimulates cardiovascular activity and induces increases in
catecholamines and prolactin in blood of both males and females. We presently
investigated the role of orgasm in producing these effects. Therefore, in this
study parallel analysis of prolactin, adrenaline, noradrenaline, and cortisol
concentrations, together with cardiovascular variables of systolic/diastolic
blood pressure and heart rate were undertaken during film-induced sexual arousal
in nine healthy adult men and nine healthy adult women. Blood was drawn
continuously via an indwelling cannula and connected tubing system passed through
a mini-pump. In parallel, the cardiovascular parameters were recorded
continuously via a computerised finger-cuff sensor. Subjective sexual arousal
increased significantly in both men and women during the erotic film, with sexual
arousal eliciting an increase in blood pressure in both males and females, and
plasma noradrenaline in females only. In contrast, adrenaline, cortisol and
prolactin levels were unaffected by sexual arousal. These data further
consolidate the role of sympathetic activation in sexual arousal processes.
Furthermore, they demonstrate that increases in plasma prolactin during sexual
stimulation are orgasm-dependent, suggesting that prolactin may regulate a
negative-feedback sexual-satiation mechanism.
PMID- 10674283
TI - Long-term residual complaints and psychosocial sequelae after remission of
hyperthyroidism.
AB - The issue of residual complaints after treatment for hyperthyroidism in current
euthyroid patients was investigated by means of a survey. Patients treated for
hyperthyroidism were selected from medical records of the previous 6 years in two
Dutch University Clinics. After the exclusion of patients with comorbidity, 303
one-time hyperthyroid respondents were included in the analysis. A total of 77%
of these patients had been diagnosed with Graves' Disease. The newly developed
Hyperthyroidism Complaint Questionnaire (HCQ), was used to quantify problems of
somatic and mental functioning. The SymptomsCheckList-90 (SCL-90) was used to
assess self-reported psychopathological symptoms, the Nottingham Health Profile
was used to measure perceived health/quality of life. Dysthyroid patients (n =
20) had a mean HCQ-score of 14.5 (+/- 8.1) complaints; patients who reported
euthyroidism for less than 12 months (n = 171) had a mean of 9.3 (+/- 7.6)
residual complaints; patients who reported euthyroidism for more than 12 months
(n = 54) a mean of 6.6 (+/- 6.8) residual complaints. On each dimension of
psychopathology covered by the SCL-90, including depression and anxiety,
approximately one third of the total sample had a score exceeding 80% of adult
females. According to the NHP lack of energy was evident in 53% of all
respondents. Over one third of patients with a full-time job were unable to
resume the same work after treatment. It appears that many of these patients are
in need of psychological support.
PMID- 10674284
TI - 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX): toxicological
properties and risk assessment in drinking water.
AB - MX (3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone), one of the byproducts
formed during the chlorine disinfection process of drinking water, shows strong
mutagenic activity for Salmonella strains in the Ames test. In several countries,
the contribution of MX to the total mutagenicity of drinking water is estimated
to range from 7% to 67%. To assess the risk of MX for human health, we summarized
the toxicological properties of MX and estimated the tolerable daily intake (TDI)
or tolerable concentration in drinking water. MX is genotoxic in cultured
mammalian cells and causes in vivo DNA damage in several tissues. MX is
carcinogenic for rodents in addition to possessing skin and gastric promotion
activities. From these toxicological profiles of MX, we estimated the virtual
safety dose (VSD) for genotoxic action as 5 ng/kg/d and the TDI for non-genotoxic
action of MX as 40 ng/kg/d. We assumed a tolerable MX concentration of 150 ng/L
in drinking water. Because of the uncertainty about human genotoxicity, however,
and the lack of information on reproductive or developmental toxicity, the
estimated tolerable dose level may be provisional.
PMID- 10674285
TI - Particulate air pollution and asthma: a review of epidemiological and biological
studies.
AB - The link between exposure to air pollution and exacerbation of asthma symptoms
has been investigated by epidemiological study and by direct biological
experimentation. In asthmatics, epidemiological studies generally show a positive
correlation between the particulate fraction of air pollution and increased
morbidity, although roles for other co-pollutants (for example, ozone) are
implicated as well. Direct experimentation using air pollutants, especially
particles, to investigate their effects on humans or on animal models of asthma
provides corroboration of the epidemiology and has begun to identify the
pathophysiological mechanisms involved. We begin this review with an overview of
air pollution, followed by a survey of the epidemiological and experimental data
regarding air pollution particles and asthma. We finish with a discussion of
directions for future research.
PMID- 10674286
TI - Inverse social gradient of secondary immune response parameters in children.
AB - BACKGROUND: In children, the prevalence of allergy increases with increasing
socioeconomic status. If frequent immune response stimulation by infections
protects against development of allergic diseases, then a social gradient in
infections should exist. The aim of our study was to assess the relation between
social class, immune parameters, and the prevalence of respiratory infections in
children. METHODS: A cross-sectional survey examined children aged 5 to 14 years
in 3 communities of Sachsen-Anhalt, Germany. Data of 1724 children were gathered
by a parent-completed questionnaire and analyses of blood samples. Social class
was defined by parental educational level. Immune parameters included serum
immunoglobulin (Ig)G, IgA, and IgM; the C3c component of complement; and the
total leukocyte count. The period prevalence of febrile colds and lifetime
prevalences of physician-diagnosed bronchitis, tonsillitis, otitis media, and
pneumonia were assessed from parents' reports. Adjusted odds ratios for the
association between social class and belonging to the group of children with
immune parameter levels in the upper 50th or 75th percentile or experiencing
respiratory infections were calculated by logistic regression. RESULTS: Social
class was inversely associated with secondary immune response parameters (IgG,
IgA), whereas indicators of primary immune reactions and inflammation (IgM, C3c,
leukocytes) were not related to social status. While an inverse social gradient
was found for the period prevalence of febrile colds, the frequency of
bronchitis, tonsillitis, and otitis media decreased with decreasing social class.
CONCLUSIONS: Health inequalities exist in immune reactions and respiratory
infections in children from different social classes. We hypothesize that in
children from lower social classes, increased frequency of infections stimulated
the secondary immune response and protected against more severe courses of
respiratory infections.
PMID- 10674287
TI - Atmospheric carcinogens in Rio de Janeiro during the summer of 1998/99:
benzo[a]pyrene and benzene.
AB - Rio de Janeiro, the second largest city in Brazil, is affected by severe
pollution episodes and presents a high respiratory cancer incidence in comparison
with the rest of the country. To monitor atmospheric pollution during the summer
of 1998/1999 and to estimate the impact of organic pollution on public health, we
determined the levels of two carcinogenic organic chemicals, benzo[a]pyrene and
benzene, in four distinct sites throughout the city. A review of the levels
recorded in other urban areas worldwide during the last ten years indicates that
the benzo[a]pyrene (< or = 0.70 ng/m3) and benzene (< or = 11 micrograms/m3)
concentrations found in Rio are relatively low. The highest levels were generally
recorded in developing Asian countries, whereas the lowest values were found in
North America. Unlike urban areas in temperate zones, pollution derived from
domestic heating is minor in Rio de Janeiro, where most of the benzo[a]pyrene and
benzene pollution originates from vehicular traffic. The quite distinct fuels
used in light-duty vehicles in Brazil, combined with strong light incidence and
increased rainfall during the summer, also contribute to diminish the levels of
such pollutants.
PMID- 10674288
TI - Indoor allergen exposure in west and East Germany: a cause for different
prevalences of asthma and atopy?
AB - West and East Germans have been living in two different political systems for 40
years. These two populations have become a classic epidemiological example for
the hypothesis that lifestyle changes accompanying the industrial and economic
development of modern societies are responsible for an increase in the prevalence
of atopic diseases. A higher prevalence of atopic sensitization, asthma, and hay
fever was found in young West Germans after the unification. It has been
hypothesized that this phenomenon was at least partially due to the installation
of insulating windows and central heating systems in Western homes, favoring the
growth of microorganisms like mites and moulds and increasing indoor allergen
exposure. This review summarizes studies that have investigated reservoir
concentrations of indoor allergens in public buildings and private homes in East
and West Germany. Whereas a higher prevalence of atopic sensitization in West
Germans was found for nearly all tested allergens (cat, mite, pollen), allergen
exposure was higher only for cat allergens, but probably not for mite and
cockroach allergens or moulds. The published data do not support the view that
the differences in specific sensitization are caused by differences in the
exposure to specific allergens.
PMID- 10674289
TI - Complex interconvertibility of nitrogen oxides (NOX): impact on occupational and
environmental health.
AB - Oxides of nitrogen have been implicated in a vast number of environmental and
occupational health effects, some of which lack concrete mechanisms. Whereas
certain compelling pieces of evidence link a particular nitrogen oxide to a
particular adverse health effect, other reports seem to implicate virtually all
the oxides in one form of toxic process or the other. Such diversity has probably
emerged because each oxide of nitrogen possesses a different oxidation state, in
which each form exerts different important levels of biological activity. Most
important, each nitrogen oxide readily interconverts into another oxide at a very
fast rate. This property of rapid interconvertibility poses problems to
researchers in identifying with great confidence the actual oxide of nitrogen
that is responsible for a specific occupational and environmental health effect.
This paper reviews the complex nature of the nitrogen oxides (represented
collectively as NOX) to explore the extent to which their acute or chronic
exposure could be associated with toxicity. The nomenclature of the nitrogen
oxides is outlined as a necessity for clarity and simplicity in understanding
their reactions and interconvertibility and how they affect health. The natural
occurrence and sources of occupational and environmental exposures and effects
are critically evaluated and analyzed.
PMID- 10674290
TI - Use of reversed-phase high-performance liquid chromatography in QSAR analysis of
2,4-dihydroxythiobenzanilide analogues.
AB - Thiobenzanilides are found to show strong biological activity as antimicrobial,
antimycotic, and tuberculostatic agents. In addition, they are relatively weakly
toxic to higher organisms. A large set of new (N-phenyl-)-2,4
dihydroxybenzenecarbothioamide derivatives was obtained. Preliminary studies
showed high microbiological action of some of them. In the process of
chromatographic analysis, several different chromatographic parameters were
obtained. In case of RP-HPLC, these parameters correspond to hydrophobicity of
the solute. Obtained chromatographic parameters exhibited moderate correlation
with calculated log P parameter. Linear dependence of bacteriostatic or
fungostatic activity on lipophilicity was observed. The degree of correlation of
different parameters was compared. The lipophilicity of analysed tioamides was
the most important factor responsible for fungostatic and bacteriostatic
activity. In comparison to methanol eluent system, chromatographic parameters
obtained in acetonitrile system were better correlated with bioactivity.
Conversely with the calculated log P values, the experimentally derived
parameters exhibited significant higher correlation to fungostatic activity
determined on dermatophytes. While in case of other tested microorganisms log P
was comparably or sometimes slightly better correlated.
PMID- 10674291
TI - Chemical diversity approach for evaluating mechanistic relatedness among
toxicological phenomena.
AB - The CASE/MULTICASE structure-activity relationship (SAR) system was used to
assess a new procedure to investigate the mechanistic relatedness of various
toxicological endpoints. The method consisted of predicting the activity of
10,000 randomly selected chemicals using validated and characterized SAR models
from a variety of biological and toxicological endpoints. The prevalence of
chemicals predicted to possess the ability to induce two or more toxicological
effects simultaneously should provide a measure of the mechanistic relatedness of
these phenomena. Eight toxicological endpoints were predicted and the results
were compared to predictions based on an eye irritation SAR model. Allergic
contact dermatitis demonstrated a 29.6% greater than expected overlap between
expected and observed results (p < 0.001). Similar results were seen for
respiratory hypersensitivity (33.1%), sensory irritation (28.9%), cell toxicity
(25.9%), and Ah receptor binding (19.8%). A lesser degree of overlap was seen
between eye irritation and Salmonella mutagenicity (11.5%) and the inhibition of
gap junction intercellular communication (6.7%). Moreover, a negative overlap,
suggesting possibly an antagonistic phenomena, was observed between eye
irritation and alpha 2 mu-induced nephropathy. These results indicate that this
method can provide a useful tool to investigate mechanistic relatedness between
diverse toxicological endpoints.
PMID- 10674292
TI - Using molecular quantum similarity measures as descriptors in quantitative
structure-toxicity relationships.
AB - In this paper molecular quantum similarity measures (MQSM) are used to describe
molecular toxicity and to construct Quantitative Structure-Toxicity Relationships
(QSTR) models. This study continues the recently described relationships between
MQSM and log P values, which permits to use the theoretical MQSM as an
alternative to the empirical hydrophobic parameter in QSPR studies. In addition a
new type of MQSM is presented in this work: it is based on the expectation value
of electron-electron repulsion energy. The molecular properties studied here, as
application examples are aquatic toxicity, toxicology on Bacteria and inhibition
of a macromolecule employing four different molecular sets.
PMID- 10674293
TI - QSAR analyses of the toxicity of aliphatic carboxylic acids and salts to
Tetrahymena pyriformis.
AB - Carboxylic acids have been conspicuously absent from the quantitative structure
activity relationship (QSAR) literature. This study investigated the aquatic
toxicity (log(IGC50(-1)) of selected mono- and di-carboxylic acids and their
sodium, or disodium salts, tested in the Tetrahymena population growth assay. The
relationship between log(IGC50(-1)) and hydrophobicity as described by the 1
octanol/water partition coefficient (log Kow) revealed a distinct sub-class. The
relationship [log(IGC50(-1)) = 0.27(log Kow) - 0.68; n = 16, r2 = 0.943, s =
0.07, F = 233, Pr > F = 0.0001] was derived for mono-carboxylic acids. The QSAR
[log(IGC50(-1)) = 0.19(log Kow) - 0.66; n = 9, r2 = 0.951, s = 0.08, F = 135, Pr
> F = 0.0001] was generated for the di-carboxylic acids. Regression analysis of
data for the monosodium carboxylic acid salts yielded the model, log(IGC50(-1)) =
0.60 (log Kow) + 0.58; n = 4, r2 = 0.932, s = 0.19, F = 41.2, Pr > F = 0.008.
Values for the ionization constant (pKa) and the energy of the lowest unoccupied
molecular orbital (ELUMO) do not vary within the sub-class for saturated acids.
Moreover, pKa and ELUMO did not describe differences in toxicity between sub
classes of saturated aliphatic carboxylic acids and salts. However, these
descriptors did vary for unsaturated acids. Inclusion of unsaturated acids
afforded the derivation of a global response-surface for all aliphatic carboxylic
acids, log(IGC50(-1)) = 0.25(log Kow) - 0.13(ELUMO) - 0.54; n = 34, r2 = 0.850, s
= 0.138, F = 87.9, Pr > F = 0.0001. Outliers to the response-surface included
small molecules that provided 2-positions in which the molecule could potentially
undergo electrophilic attacked and other more large, hydrophobic molecules.
PMID- 10674294
TI - Should research become mandatory in future vocational training of general
practitioners?
PMID- 10674295
TI - From teaching to learning. Experiences of small CME group work in general
practice in Sweden.
AB - OBJECTIVE: To describe the experiences of learning in small groups and the impact
of small group continuing medical education (CME). DESIGN: Literature review,
personal communication and critical reflection. SETTING: General practice in
Sweden. SUBJECTS: Small CME groups. MAIN OUTCOME MEASURES: Occurrence, themes and
impact of small CME groups. RESULTS: In 1998, there were approximately 230 small
CME groups in Sweden, which means that nearly half of Swedish general
practitioners (GPs) participated in such activities. Although widely used in
Sweden, small CME groups are less practised than "traditional" CME activities,
such as lectures. Group work might enhance knowledge development, enable the
assessment of individual learning needs and facilitate the adoption of national
guidelines and agreements between primary and secondary care. A competent group
leader is crucial. CONCLUSION: A transition from passive to interactive learning
in small groups is recommended.
PMID- 10674296
TI - The influence of sociodemographic characteristics on well-being and symptoms in a
Swedish community. Results from a postal questionnaire survey.
AB - STUDY OBJECTIVE: To assess the influence of sociodemographic characteristics on
self-reported well-being and symptoms. DESIGN: A postal questionnaire was sent to
a representative population sample drawn from the population census. SETTING: The
municipality of Habo, Sweden. PARTICIPANTS: Out of 1312 subjects in the
population sample, 827 (63%) participated in the study, i.e. answered the
questionnaire. RESULTS: Sociodemographic characteristics significantly influenced
most well-being variables and symptoms. The prevalence of symptoms in the
categories depression and tension, as well as headache, decreased while most
other symptoms increased with age. Women had more symptoms than men. Married
subjects, compared to others, had higher social and mental but lower physical
well-being. Subjects from households with up to three persons, and subjects with
comprehensive school only, had lower physical well-being than other subjects.
Working subjects generally had a higher well-being than non-working subjects.
CONCLUSION: Sociodemographic characteristics had a significant influence on most
well-being variables and symptoms.
PMID- 10674297
TI - Detecting child sexual abuse in general practice: a retrospective case-control
study from Wales.
AB - OBJECTIVE: To investigate if routine medical contacts provide indicators that
would assist general practitioners in detecting male child abuse. DESIGN: A case
control study of the general practice records of male victims of a major episode
of school-based child abuse and matched controls. SETTING: General practices
serving cases and controls from two South Wales schools. SUBJECTS: 107 abused
boys and 107 aged-matched controls. RESULTS: No boys had disclosed sexual abuse
to general practitioners. Somatic and behavioural symptoms were reported by small
numbers in both groups (18 cases/25 controls). Odds ratios showed no significant
positive association between abuse and numbers of boys presenting with symptoms
(odds ratio 0.66; 95% confidence interval 0.32-1.37), and no difference could be
found in the nature of the symptoms complained of by boys from the two groups.
However, abused boys were more likely than controls to present with symptoms that
persisted for more than a year (eight cases compared with one control). The two
tailed p-value calculated using the Fisher exact test was 0.035, suggesting a
statistically significant association between abuse and persistent symptoms.
CONCLUSIONS: Sexually-abused boys are unlikely to visit general practitioners
with open requests for help, and do not appear to present with behavioural or
somatic symptoms different from those presented by non-abused boys. However,
where boys complain of persistent, inexplicable, somatic or behaviour problems
over a period of time, the possibility of abuse should be considered.
PMID- 10674298
TI - The management of chronic neck pain in general practice. A retrospective study.
AB - OBJECTIVE: To describe the management in patients with chronic non-specific neck
pain in general practice. DESIGN: A descriptive, questionnaire-based
retrospective study. SETTING: General practices in the Netherlands. PATIENTS: 517
patients with chronic non-specific neck pain. MAIN OUTCOME MEASURES: Nature and
frequency of diagnostic procedures, therapeutic interventions and referrals by
the general practitioner (GP). RESULTS: Forty-four per cent visited the GP for
neck pain in the previous year. Of the patients who did visit the GP in the
previous year, 32% did not receive a diagnostic modality, 31% did not receive
therapy and 43% were not referred. The most frequently applied diagnostic and
therapeutic modalities were physical examination (66%) and pain medication (58%),
respectively. The GPs most frequently referred to a physiotherapist (51%).
CONCLUSION: Once neck pain has become chronic, the minority (44%) of patients do
seek help from their GP on a yearly base. In spite of the fact that the patients'
conditions are non-specific and chronic, GPs still find indications for further
diagnostics in two-thirds of patients. The GPs were rather consistent in their
management, as the nature of the diagnostic/therapeutic modalities and referrals
was similar in more than 50% of the patients.
PMID- 10674299
TI - Allergological examination in general practice and in the specialist field of
allergology. A comparative study of the concordance between a group of general
practitioners and the allergological specialised health care services to which
they refer.
AB - OBJECTIVE: To study the concordance between specially trained general
practitioners (GPs) and specialist doctors working as consultants to GPs, with
regard to diagnosis of allergic illnesses, evaluation of indications for
hyposensitisation, and referrals from GPs to specialists. DESIGN: Thirty-four GPs
and five specialists practising privately and eight allergologic outpatient
clinics participated. The patients included had symptoms indicating allergologic
examination. An identical diagnostic procedure was used by the GPs and by the
specialists/outpatient clinics. SETTING: General practices, specialist practices,
outpatient clinics. SUBJECTS: One-hundred and forty-eight patients. MAIN OUTCOME
MEASURES: With regard to skin-prick test there was concordance between the GPs
and the specialists in 82.5% of 1322 paired comparisons, in 74.0% with regard to
anamnesis + skin-prick test, and in 66.5% with regard to the statement allergy.
There was concordance with regard to indication for hyposensitisation in 88.3%,
and for referral in 54.1%. There was symmetry concerning prick test and anamnesis
+ prick test, and asymmetry concerning the statement allergy, and indication for
hyposensitisation and for referral. CONCLUSIONS: Specially trained GPs diagnosed
specific allergy in concordance with specialists. There was asymmetry between GPs
and specialists concerning the statement allergy, indication for
hyposensitisation and for referral.
PMID- 10674300
TI - Ways of experiencing asthma management. Variations among general practitioners in
Sweden.
AB - OBJECTIVE: To identify and describe variations in ways of experiencing asthma
management among general practitioners (GPs) in Sweden. DESIGN: Descriptive and
explorative study using a phenomenographic approach. Semi-structured tape
recorded face-to-face interviews, focusing on the GP's own experiences regarding
asthma management. SETTING: Primary health care. SUBJECTS: Twenty GPs (12 men,
eight women) from 16 health centres in seven counties in central Sweden, 15 from
rural areas and small cities and five from medium sized cities or Stockholm
suburbs. MAIN OUTCOME MEASURES: Descriptions of ways of experiencing asthma
management. RESULTS: Four categories were identified, which described
qualitatively different ways of experiencing asthma management: A. The GP focuses
on transferring factual knowledge to the patient; B. The GP primarily addresses
the patients' application of knowledge in management of the disease; C. The GP
aims at improving the patients' understanding of the disease and its management
as a prerequisite for self-management; D. The GP concentrates on how to
maintain/improve the patient's quality of life despite the asthma disease.
CONCLUSION: The GPs describe their ways of experiencing asthma management in
qualitatively different ways, likely to have implications for patient care and
educational programmes on asthma for GPs.
PMID- 10674301
TI - Detection of chronic obstructive pulmonary disease (COPD) in primary health care:
role of spirometry and respiratory symptoms.
AB - OBJECTIVE: To evaluate the role of spirometry and respiratory symptoms in the
detection of chronic obstructive pulmonary disease (COPD) in primary health care.
DESIGN: A cross-sectional study. SETTING: A primary health centre in Landskrona,
southern Sweden. SUBJECTS: 164 subjects who in 1992 had answered a postal
questionnaire concerning obstructive pulmonary diseases and respiratory symptoms.
They were aged 45-64 years, with a mean of 55 years. MAIN OUTCOME MEASURES: In
1997, the subjects were invited to perform a spirometry and a medical examination
and to answer the same questionnaire as in 1992. Subjects with a forced
expiratory volume in 1 second (FEV1) < 85% of the predicted normal value
performed reversibility tests. RESULTS: 131 subjects participated in the
examinations. 15 subjects (11.5%) were diagnosed as having COPD. Only three of
them had been previously diagnosed as having a respiratory disease. Many commonly
occurring respiratory symptoms were associated with a reduction in FEV1.
CONCLUSIONS: Spirometry examinations in primary health care improve the
probability of detecting COPD. A spirometry examination should be considered for
patients with respiratory symptoms. It should also be considered for middle-aged
smokers, even if they are symptom-free.
PMID- 10674302
TI - Effects of an education programme to change clinical laboratory testing habits in
primary care.
AB - OBJECTIVE: The aim of this study was to investigate the use of clinical
laboratory tests in primary care and to evaluate if it is possible to improve the
cost-effectiveness of laboratory testing by a short-term education programme. Our
main goal has been to lower the total costs of care. DESIGN: An education
programme that was monitored by laboratory test ratios. SETTING: Primary health
care. SUBJECTS: 63 primary care doctors at 19 primary care centres in the county
of Uppsala, Sweden. MAIN OUTCOME MEASURES: The effects of the education programme
were monitored by laboratory test ratios (e.g. ASAT/ALAT) of individual doctors
before and after the education programme. RESULTS: The education programme
resulted in significant changes for the majority of the ratios studied. The
savings on direct laboratory costs were approximately SEK 400,000 for assays that
were recommended to decrease. The increased cost for assays that were recommended
to increase was approximately SEK 140,000 but was considered cost-effective.
CONCLUSION: It is possible to achieve significant changes in clinical chemistry
test ordering habits of primary care doctors with a 2 day education programme. It
resulted in cost savings and a better use of clinical chemistry tests in primary
care. The effects were sustained for at least 6 months.
PMID- 10674303
TI - Insulin treatment for poorly regulated diabetic patients in general practice.
Better regulation and symptom relief?
AB - OBJECTIVE: To study the relationship between symptoms, metabolic control and
insulin treatment in diabetes mellitus. DESIGN: A cross-sectional questionnaire
study of diabetic patients, and a 1-year follow-up study of poorly regulated
patients prescribed insulin. Regulation criteria were predefined and the patients
acted as their own controls. SETTING: Five primary care practices in Nordland
county, Norway. PATIENTS: 111 patients in the cross-sectional study, with 18 of
them participating in the follow-up study. MAIN OUTCOME MEASURES: Symptom scores
and sum scores, based on five general symptoms--dizziness, depression, fatigue,
thirst and dry mouth--and on two urinary symptoms--urinary frequency and
urination during the night. RESULTS: Poorly regulated diabetic patients had a
higher sum score for general symptoms than better regulated patients (6.1 vs.
4.2, p = 0.078 with Wilcoxon two-sample rank sum test). With parametric analysis,
the difference was significant, and remained so when adjusted for age and sex.
Females reported more symptoms than males. Symptom relief with insulin was not
statistically significant; however, there was a slight but consistent tendency
towards less symptoms with better regulation. There was no correlation with HbA1
values at any time during the follow-up study. Only one patient wanted to stop
taking insulin after 1 year. CONCLUSION: Better metabolic control and better
general well-being seem to be achieved in many cases when poorly regulated
patients with type 2 diabetes mellitus begin insulin treatment. The general
practitioner should be cautious in promising relief of specific symptoms.
PMID- 10674304
TI - As a GP--will I learn anything?
PMID- 10674305
TI - [Molecular medicine reaches adulthood in 1999: from the search for the needle in
the haystack to genome navigation].
PMID- 10674306
TI - [Shark cartilage on the Internet].
PMID- 10674307
TI - [Prospects for the aged in new millennium].
PMID- 10674308
TI - [New developments in child protection--towards distinct rewards].
PMID- 10674309
TI - [On new antiviral drugs, new viruses and old known bacteria].
PMID- 10674310
TI - [HIV 1999: suppression at what price?].
PMID- 10674311
TI - [Neurology: towards the end of the millenium the end of the decade of the brain].
PMID- 10674312
TI - [Progress in the understanding of the pathogenesis and prevention of bacterial
otitis media and meningitis].
PMID- 10674313
TI - [Skin under pressure: irradiated, wounded, infiltrated].
PMID- 10674314
TI - [Refractive surgery in vision disorders: new development and proofs].
PMID- 10674315
TI - [Persistent atelectasis].
PMID- 10674316
TI - The importance of interpreters to insure quality of care for migrants.
PMID- 10674317
TI - Addressing language barriers to health care, a survey of medical services in
Switzerland.
AB - Two descriptive, quantitative cross-sectional surveys including all services of
internal medicine and psychiatric services examined how Swiss medical services
address the problem of language barriers in health care and how they respond to
the high number of allophone patients. Of all the medical services (MS), 244
responded to the questionnaire (Internal medicine: 166; Psychiatry: 78; overall
response rate 86.6%). Half of them (51%) estimated the proportion of allophone to
the total number of patients at 1-5%. Only 4% of the MS collected statistics on
the number of allophone patients (2 internal medicine, 8 psychiatric services). A
third of the MS perceive communication with allophone patients as significantly
difficult. Only 14% often use qualified interpreters, while 79% often use
relatives, 75% often health staff, 43% often employees. Qualified interpreters
are less frequently used in internal medicine than in psychiatry. There is an
expressed need for qualified interpreters speaking Albanian, Bosnian/Serbo-croat,
Tamil and Kurdish. Only 11% of the studied MS have a budget for interpreters, and
17% have access on an interpreter service. 48% express the need to have access to
interpreter services. There is a need to raise the awareness of health
professionals on the advantages of having access to trained interpreters and on
the limits of using relatives as translators. This calls for coordination at
national level, policy development and training, in order to ensure adequate
communication and quality care for migrants.
PMID- 10674318
TI - [When patients and doctors don't speak the same language-- concepts of
interpretation practice].
AB - In the Swiss Health Care System, working with an interpreter while medically
treating migrants speaking a foreign language has become a common practice.
However, the theoretical and conceptional framework of this practice has not yet
been sufficiently elaborated. Specifically, the presence of an interpreter leads
to a triadic interviewing situation that has implications for the medical
treatment. Though an interpreter can improve and deepen the understanding between
patient and physician, the communication can also become more complex and
difficult with his or her presence. The article sheds light on the perspectives
that arise from this situation by defining different role models for medical
interpreters and discussing their advantages and disadvantages. The discussion
focuses on the four following ideal types: word-for-word translation, cultural
mediation, patient advocacy and co-therapy. The choice of interpreter's role in
influenced by the institutional setting, the kind of treatment chosen as well as
by the concrete interaction. To illustrate the different roles as they manifest
in the therapeutic situation, examples from taped and retranslated interviews are
presented. Doctor-patient interviews will illustrate the different roles
interpreters take over while interpreting medical interviews with migrant
patients speaking a foreign language.
PMID- 10674319
TI - [Migrant populations at the Hopital de l'Enfance of Lausanne (HEL): evaluation
inquiry, taking care and contribution of cultural mediators-translators].
AB - The number of patients belonging to migrant populations who consult Lausanne's
Hopital de l'Enfance (HEL) has increased massively in an exponential manner. HEL
is a facility dedicated to children with a vocation of public health and training
in a university setting and it has to make a point of developing an adequate and
pertinent health care system for these populations. In order to do this, a study
was undertaken in the form of a prospective survey including over a thousand
ambulatory patients. Administrative data (origin, date of migration, nature of
the permit and legal situation), social data (home language, professional
situation, number of siblings), medical (diagnosis) and psychosomatic data
(sleep, enuresis) was recorded as well as data testing the level of understanding
between carrier and patient. The study allowed us to define priorities of
intervention: introduction of a service of translators--cultural mediators
trained by the association "Appartenances" (as well as on going follow-up and
assessment of this service), training of health care workers in the fields of
cultural mediation and the different aspects of migrant population medicine and,
finally, the creation of a steering group within the Institution. Having allowed
rapid and spectacular improvement in the quality of the service provided by the
HEL, this process is also included in the will to improve health care given to
migrant populations at local and national levels in accordance with the
priorities defined by the WHO in this domain. It is this experience which is
reported in this paper.
PMID- 10674320
TI - [Health care networks, migration and cross-cultural adaptation in Lausanne: an
action-research in progress].
AB - In Lausanne, Switzerland, there is a growing population of migrant people of
different origins. This evolving situation calls for a continuous adjustment
between need and offer in terms of healthcare. Up to now, this adjustment, which
involves cross-cultural adaptation processes, was based on the use of untrained
interpreters. However, clinical experience shows that the use of untrained
interpreters tends to keep migrant patients in an unfavourable position. This
paper describes an action-research in Lausanne, which aims at the evaluation of
the changes that are brought by the introduction of trained cultural mediators
and interpreters (CMI) into the medical field. The paper enumerates the clinical
issues that gave birth to the project and the methodological choices that were
made. After discussing the first results, the authors describe how the different
research stages are adapted and modified through continuous mutual influences
between the field and the research process itself.
PMID- 10674321
TI - Medical interpreters have feelings too.
AB - All 22 members of the interpreter service of the Geneva Red Cross were invited to
answer an anonymous questionnaire with questions about their work with refugees
and asylum seekers. Five (28%) reported having been exposed to a major traumatic
event such as war, torture, detention, being beaten. Seven interpreters reported
that more than 50% of their sessions involved patients exposed to violence. Five
interpreters (28%) frequently experienced difficult feelings during sessions.
Twelve (66%) had frequently painful memories. The proportion of interpreters
having painful feelings and symptoms increases with the number of sessions with
victims of violence. Interpreters also expressed a strong need to talk and share
feelings after the session with the medical doctor (83%) or with relatives or
spouse (44%). Fifteen (83%) reported seeing patients again outside the
consultation. Doctors should be aware of these pressures and give time to
interpreters to share their feelings and emotions, to help them cope with their
reactions.
PMID- 10674322
TI - Language difficulties in an outpatient clinic in Switzerland.
AB - This small-scale study attempts to examine the languages spoken in medical
consultations during a one-month period in an outpatient clinic in Geneva and the
ways health professionals use to communicate with their allophone patients, in
particular by using interpreters. Patients of foreign origin accounted for 58% of
all the consultations during the survey. Of these, 37% were Non-French-speakers
(NFS). The four major language groups of NFS were Albanian, Somali, Tamil and
Serbo-croat. Qualified interpreters were used in 24% of the consultations,
relatives acting as interpreters in 17%, and in the other consultations without
anyone interpreting (59%), a common language had to be negotiated: French,
English, Italian, Spanish or German. In only 14% of the consultations without
interpreters, both patient's and doctors ability to speak a common language was
rated as good. Our data suggest that there has been an increasing awareness of
the possible language barriers in the medical outpatient clinic. Even if proxy
solutions (informal interpreters or the use of a common language) still play an
important role, access to an interpreter service has been widely used. This calls
for systematic and regular interpreter use, planning the interpreting needs in a
timely manner. In the future, training in working with interpreters should become
an integral part to the introductory sessions for the junior physicians assigned
to the outpatient clinic.
PMID- 10674323
TI - [Cultural mediation and training of health care professionals: from cross-culture
to co-discipline].
AB - Why organize a training course destined for health care professionals which is
specifically devoted to cultural mediation in the sphere of health care? There
are several reasons justifying such an initiative, mainly relating to the social
and cultural mutations pertaining to the present world situation. In fact, two
major phenomena may be said to directly influence the health care scene in the
current context of generalized migration: the internationalization of diseases on
the one hand and on the other hand, the cultural plurality to be found to an
increasing degree in society in general. While the responses to the first
scenario fall within the limits of standard medical practice, those which are
necessitated by the second situation demand a widening of expertise. By reason of
the relationship they establish with migrants, it is mandatory that carers should
modify their own personal attitudes as well as their professional framework. In
the face of the requirements imposed by cross-culture, it is imperative to move
in the direction of co-discipline.
PMID- 10674324
TI - Explanations of unmet need for contraception in Chitwan, Nepal.
AB - This article explores reasons why women's fertility preferences and their
contraceptive behaviors often appear to be contradictory. Ninety-eight separate
interviews with women and their husbands conducted in rural Chitwan District,
Nepal, over a 12-month period in 1993-94 revealed that people continually and
self-consciously weigh the perceived benefits and risks of practicing family
planning relative to their situations. Temporary and, especially, hormonal
methods are perceived to carry unacceptable health risks. Contraceptive
technologies are evaluated in relation to competing priorities and interests.
Household poverty heightened the perceived risk of family planning use; poor
people fear they can ill afford negative effects to their health that might
result. People assess their health status and physical workload, factors that
they believe condition their ability to use family planning methods without
experiencing damaging health effects. Strategies employed to lower contraceptive
risk include altering the method of choice, manipulating relationships with
spouses, timing the adoption of contraceptives, managing the context of service
provision, and acting in light of the experiences of others. Qualitative findings
from the fieldwork are complemented by analysis of data from a standardized
fertility survey.
PMID- 10674325
TI - Understanding the prevalence of female sterilization in rural south India.
AB - By analyzing the practice of female sterilization in rural Andhra Pradesh, in
southern India, this article examines the role culture plays in demographic
research. The popularity of female sterilization in rural Andhra Pradesh is shown
to be intelligible if the symbolic value of a young mother's reproductive
capacity is understood in terms of familial power relations. Through
sterilization, young mothers can symbolically push their influential mothers-in
law toward old age, thus increasing their own relative prestige, and they can
strive to control the ambiguity surrounding their reproductive functions. This
study is based on 14 months of participant observation in three rural villages, a
survey of 396 households, and unstructured interviews with 42 women and two men.
It shows how demography and anthropology can be mutually supportive in their
efforts to clarify population phenomena.
PMID- 10674326
TI - Household organization, women's autonomy, and contraceptive behavior in southern
Ethiopia.
AB - The Southern Nations, Nationalities, and People's Region of Ethiopia (SNNPR) is
home to 11 million people constituting more than 45 language and ethnic groups,
most of whom live in extremely poor rural communities. Data for currently
married, fecund women aged 15-49 from demographic surveys conducted in the SNNPR
in 1990 and 1997 are used to investigate contraceptive knowledge and
communication, and the use and future need for family planning services in this
population. This study focuses on how these processes are affected by household
organization and women's status, and on their implications for population
policies and programs. Considerations of the implications of these results for
understanding the fertility transition of a highly diverse African population
under severe stress are presented. Although household extension and polygamy
characterize one-third of the women sampled, they do not affect the women's
contraceptive behavior. Women's literacy and autonomy are, by far, the most
significant forces in the movement toward lower fertility in the region.
PMID- 10674327
TI - Contraceptive switching in Bangladesh.
AB - Bangladesh has experienced a substantial decline in fertility that has been
achieved by means of a large increase in the use of modern methods of
contraception. As contraceptive prevalence increases, aspects of contraceptive
use dynamics, including reasons for discontinuation and behavior after
discontinuation, become important influences on fertility. This report uses
calendar data from the 1993-94 Bangladesh Demographic and Health Survey to
examine contraceptive behavior following discontinuation of modern-method use.
The individual-level characteristics found to influence switching behavior
include the method used, method-related difficulties with previous contraceptive
use, and education. A large amount of unexplained variation in switching rates
remains, however, largely at the individual level, but also at the community
level for certain types of transition.
PMID- 10674328
TI - Maternal mortality in Vietnam in 1994-95.
AB - This report presents the first population-based estimates of maternal mortality
in Vietnam. All the deaths of women aged 15-49 in 1994-95 in three provinces of
Vietnam were identified and classified by cause. Maternal mortality was the fifth
most frequent cause of death. The maternal mortality ratio was 155 deaths per
100,000 live births. This ratio compares with the World Health Organization's
estimates of 430 such deaths globally and 390 for Asia. The maternal mortality
ratio in the delta regions of these provinces was half that of the mountainous
and semimountainous regions. Because a larger proportion of the Vietnamese
population live in delta regions than elsewhere, the maternal mortality ratio for
Vietnam as a whole may be lower than that of the three provinces studied.
Maternal mortality is low in Vietnam primarily because a relatively high
proportion of deliveries take place in clinics and hospitals, where few women die
in childbirth. Also, few women die of the consequences of induced abortion in
Vietnam because the procedure is legal and easily available.
PMID- 10674329
TI - Assessing recall and understanding of informed consent in a contraceptive
clinical trial.
PMID- 10674330
TI - Kyrgyz Republic 1997: results from the Demographic and Health Survey.
PMID- 10674331
TI - Yemen 1997: results from the Demographic and Health Survey.
PMID- 10674332
TI - [Risk factors for posttraumatic fits and epilepsy].
AB - There is still a considerable controversy about the usefulness of antiepileptic
prophylaxis after traumatic brain injury. Overall incidence of posttraumatic fits
and epilepsy's is well known, but an individual decision on prophylaxis requires
knowledge about the individual risk. We performed a prospective observational
study on 612 patients with traumatic brain injury of every degree of severity.
Follow-up by phone call included 96.2% of the study population after 6 month and
91.2% after 36 month, respectively. The overall incidence for early fits (within
7 days after trauma), late fits (up to 36 month) and epilepsy (as defined by the
International League Against Epilepsy) was 4.2%, 3.7% and 2.5%, respectively.
These incidences increased according to the severity of the trauma, but the most
powerful single predictor was intracranial hemorrhage. There was no significant
difference related to the hemorrhage localisation. Development of epilepsy was
much more common after late fits (48%) than after early fits (17%). These
features established a hierarchy of risks for the development of epilepsy: no
intracranial hemorrhage/no fit: 1% (4/437), intracranial hemorrhage/no fit: 8%
(10/122), intracranial hemorrhage/early fit: 16% (3/19), intracranial
hemorrhage/late fit: 53% (7/13). If prophylactic antiepileptic treatment is
desired, but should be restricted to patients at high risk. These are patients
with intracranial hemorrhage--are a well defined high risk group--when their
first fit is a late fit.
PMID- 10674333
TI - [Neuropsychological fields in early neurotrauma rehabilitation].
AB - It meanwhile is commonly accepted that early onset of specific rehabilitation
intervention in traumatic brain injured patients will enhance the recovery of
brain function. The integration of neuropsychology in the early treatment of
traumatic brain injury can mainly be ascribed to the increasing recognition that
cognitive, personality and emotional deficits have been the most devasting
longterm problems faced by patients and their families. The aim of our paper is
to illustrate the role of neuropsychology in the early stage of rehabilitation.
Neuropsychological therapy and the application of appropriate tests depend on the
level of consciousness and the extent of behavioural problems. Observation,
cognitive screening tests and the use of valid neuropsychological tests make up
the main approaches. Our rehabilitation program includes measures of sensory and
cognitive stimulation. Improvement of attention and stimulation of cognitive
functions are one of the most important aims of early neuropsychological therapy.
We choose tasks which require automatic information processing, the retrieval of
well established knowledge and implicit learning. Appropriate tests and the
development of neuropsychological treatment programmes represent an important
means of maximising the patient's capacity to benefit from early rehabilitation.
PMID- 10674334
TI - Management of vein of Galen malformations. A review based on five neurosurgically
treated cases and literature reports.
AB - The high morbidity and mortality associated with the management of vein of Galen
aneurysmal malformations (VGAM) continues to pose a tremendous challenge to the
neurosurgeon as well as to the attending interventional radiologist. Since 1985,
five patients with VGAM have been referred to the neurosurgical unit of the
University of Cologne, two neonates, one infant and two adults. Four patients
underwent direct operation and two patients received a shunt. The treatment was
performed without mortality. A review of the literature reflects no substantial
difference between neurosurgical treatment during the last 15 years (mortality
10%) and endovascular treatment (best series mortality 6%).
PMID- 10674335
TI - [Value of German Hospital Diagnosis Statistics in epidemiology-- an analysis with
subarachnoid hemorrhage as an example].
AB - Due to the Hospital Statistics Regulations of the 10th April 1990, the German
Hospital Diagnosis Statistics were introduced in 1993 with the intention to serve
as a database of health care decisions. This purpose requires a high-quality
collection of epidemiologically relevant data. From 1993 to 1996 we analysed the
datasets obtainable for subarachnoid haemorrhage which is coded with ICD 430. A
subset concerning the data of 1996 and the Saarland region was compared to the
data of the Saarland medical school at Homburg/Saar. Cases treated in the
neurosurgical department were critically reviewed. About 20% of the cases coded
with ICD 430 showed no subarachnoid haemorrhage. On the other hand, again about
20% of subarachnoid haemorrhage cases were not coded with ICD 430. The statistics
comprise duplicates due to transfers between hospitals. The calculation of
incidence is not possible because new bleeding cases cannot be outlined. In the
present form the German Hospital Diagnosis Statistics are not suitable as a
reliable base of health care decisions. This is partly caused by the inadequacy
of the ICD-classification but, also, by the criteria for collecting data. We
propose several modifications which can improve data quality in order to meet the
intended requirements.
PMID- 10674336
TI - [Paralysis of the foot as the first symptom of a herniated thoracic disc].
AB - Herniated thoracic discs are uncommon entities that are difficult to diagnose.
They may be associated with a myriad of symptoms, which often delays diagnosis.
In general dorsal pain that radiats around the chest or abdomen are found. In
case of spinal cord compression signs of thoracal myelopathy are common. This
paper describes a patient with a complete paralysis of the left foot as the first
symptom of a herniated thoracic disc. After frustrated diagnostic of the lumbar
spine, the exact neurological examination showed a sensible cut at the level of
D6/7, the MR tomography diagnosed a herniated thoracic disc at the same level.
Four months later he was presented again with a plegia of the left foot and a
sensible cut at the level D5/6. The MR tomography showed a herniated disc at the
level above the spondylodesis. The immediately performed transthoracic disc
excision and fusion of D6/7 was followed by complete remission of the plegia and
the sensible cut. Four months later we performed a rethoracotomy, disc excision
and decompression with a spondylodesis D5/6. The procedure was again followed by
complete remission. In case of paralysis of the lower extremities one has to
consider a herniated thoracic disc.
PMID- 10674337
TI - Evaluation of abstracts submitted for the annual meeting of the German
Neurosurgical Society 1999--unravelling a mystery.
AB - The evaluation for the abstracts submitted for the annual meeting of the German
Neurosurgical Society together with the Swiss Neurosurgical Society in Munich
1999, is presented as it has developed during the meetings of the last years. 597
abstracts were reviewed by the 30 members of the review committee according to a
5 point grading system. Cut off for acceptance was a mean grading of 2.7 points.
Abstracts better than 2.4 were accepted, abstracts worse than 2.7 were rejected.
Experimental studies were judged slightly better than clinical studies: the mean
grading of clinical and experimental studies was 2.55 +/- 0.5 vs. 2.72 +/- 0.6 (p
< 0.02). All abstracts with a mean grading of 2.4-2.7 and a standard deviation >
1.0 were discussed in a meeting of the review committee. 353 abstracts were
accepted. Some of the abstracts submitted for oral presentation had to be
converted to poster presentations. Among others the decision was based on the
grading of the abstract.
PMID- 10674338
TI - [Good practice: guidelines for neurosurgery. European Association of
Neurosurgical Societies World Federation of Neurosurgical Societies].
PMID- 10674339
TI - CMV in HIV-infected newborns.
PMID- 10674340
TI - Telomerase, immortality, and cancer.
PMID- 10674341
TI - The adenovirus and bronchopulmonary dysplasia: an association that could be
causal or coincidental.
PMID- 10674342
TI - Thrombopoietin and neonatal thrombocytopenia.
PMID- 10674343
TI - Neural crest-derived defects in experimental esophageal atresia.
AB - Esophageal atresia (EA) is often associated with cardiovascular and other
malformations that are likely neural crest derived. The present study tests the
hypothesis that the heart and great vessels and the thymus and parathyroids may
be abnormal in the rat model of EA as a result of disturbed neural crest
development. Time-mated pregnant rats received intraperitoneally on d 8 and 9 of
gestation either 2 mg/kg adriamycin or vehicle. Esophageal, heart, and thymic
malformations were sought under the microscope in term fetuses. The parathyroids
were histologically investigated. Control fetuses had no malformations, whereas
69 of 109 fetuses exposed to adriamycin had EA and 45 of 69 had 15 right aortic
arches, nine aberrant right subclavia, eight ventricular septal defects, six
narrow pulmonary outflow tracts, five tetralogies of Fallot, three double outflow
right ventricles, three double aortic arches, three atrial septal defects, three
right ductus arteriosus, and two truncus. The thymus was absent in 19,
hypoplastic in 12, and ectopic in five out of 36 fetuses with EA in which it was
studied, whereas the parathyroid glands were absent in 16, single in four, and
ectopic in one of the 23 fetuses with EA in which they were studied. In
conclusion, the nature of the cardiovascular, thymic, and parathyroid
malformations associated with EA in rats is consistent with the hypothesis of
neural crest participation in their pathogenesis. Mechanisms simultaneously
disturbing foregut septation, somitic segmentation, and neural crest development
should be sought to explain the combined occurrence of malformations in EA.
PMID- 10674344
TI - Discoordinate expression of pancreatic lipase and two related proteins in the
human fetal pancreas.
AB - The lipase gene family contains a large number of members. Among the most closely
related are pancreatic triglyceride lipase (PTL) and two pancreatic lipase
related proteins (PLRP1 and PLRP2). Previous studies in rodents demonstrated
divergent temporal expression of the genes encoding these proteins. PLRP1 and
PLRP2 were expressed in fetal pancreas, whereas PTL was not expressed until pups
were several weeks old. To determine whether the human pancreas has a similar
expression pattern for these genes, we determined the levels of each mRNA in
fetal pancreas at various ages. A reverse transcriptase-PCR method was developed
and used to quantify the mRNA levels for the three species normalized to the mRNA
encoding cyclophillin. The mRNA encoding PLRP1 and PLRP2 was present by 16 wk in
the fetal pancreas. In contrast, the mRNA encoding PTL was not present in the
fetal pancreas. This pattern of expression suggests that the genes encoding
theses proteins have different regulatory elements controlling temporal
expression and provides another example of nonparallel expression of genes
encoding pancreatic exocrine proteins.
PMID- 10674345
TI - Regulation of fetal rat bone growth by C-type natriuretic peptide and cGMP.
AB - C-type natriuretic peptide (CNP) and its high affinity receptor-B are expressed
in fetal bones. Here we show that CNP accelerates longitudinal growth of fetal
rat metatarsal bones in organ culture by several mechanisms. First, CNP
stimulates chondrocyte proliferation in the proliferative zone as assessed by
[3H]thymidine incorporation. Second, CNP stimulates cell hypertrophy as assessed
by quantitative histology. Third, CNP stimulates cartilage matrix production as
assessed by incorporation of 35SO4 into glycosaminoglycans. Natriuretic peptide
receptor-B contains an intracellular guanylyl cyclase catalytic domain. We
therefore hypothesized that cyclic GMP (cGMP) would reproduce the effects of CNP
on fetal bones. Consistent with this hypothesis, we found that 8-Br-cGMP, like
CNP, stimulates longitudinal growth and glycosaminoglycan synthesis. However,
unlike CNP, cGMP inhibits proliferation of growth plate chondrocytes and has no
effect on hypertrophy. We conclude that CNP stimulates longitudinal bone growth
by increasing chondrocyte proliferation, chondrocyte hypertrophy, and cartilage
matrix production. cGMP, a second messenger for CNP, reproduces some but not all
of the effects of CNP, suggesting that other signal transduction mechanisms may
also be involved.
PMID- 10674346
TI - Milk-borne epidermal growth factor modulates intestinal transforming growth
factor-alpha levels in neonatal rats.
AB - Epidermal growth factor (EGF) is present in milk from various mammalian species,
but its physiologic function in neonatal development remains unclear.
Transforming growth factor-alpha (TGF-alpha) is a peptide structurally related to
EGF, and its presence is detected in the developing small intestine of rats. The
purpose of the present study was to examine the effect of milk-borne EGF on
endogenous production of EGF and TGF-alpha in the small intestine of suckling
rats. Neonatal rats were fed via gastrostomy either growth factor-free rat milk
substitute (RMS) or RMS supplemented with EGF (100 ng/mL of RMS) from 8 to 12 d
of age. Artificially reared rats were then compared with their dam-fed
littermates. Animals fed the EGF-deficient diet RMS had markedly increased EGF
and TGF-alpha mRNA levels in duodenum and ileum compared with dam-fed controls
and significantly elevated total intestinal content of TGF-alpha peptide.
Intestinal EGF content and EGF serum levels were significantly decreased in the
RMS group compared with controls. The addition of EGF to the RMS diet normalized
TGF-alpha mRNA levels in the duodenum and ileum, EGF mRNA levels in the ileum,
and total intestinal TGF-alpha content and EGF serum levels to the levels
measured in dam-fed littermates. Motility studies showed that enteral
administration of EGF did not affect stomach emptying and intestinal transit.
These studies indicate that exogenous milk-borne EGF modulates endogenous
production of TGF-alpha in developing small intestine. It is likely that neither
TGF-alpha nor EGF are solely responsible for small intestinal overgrowth of
artificially reared neonatal rats.
PMID- 10674347
TI - Increased local synthesis of epidermal growth factors in infantile hypertrophic
pyloric stenosis.
AB - Infantile hypertrophic pyloric stenosis (IHPS) is characterized by hypertrophy of
the pyloric muscle. The growth of smooth muscle cells is regulated by several
growth factors. Epidermal growth factor (EGF) and heparin-binding EGF-like growth
factor are potent mitogens for smooth muscle cells. In the present study, we
investigated immunohistochemical localization of EGF and EGF-related peptides and
EGF mRNA expression in pyloric smooth muscle cells to determine whether the EGF
family is involved in the process of pyloric muscle hypertrophy in IHPS. Pyloric
muscle biopsy specimens were obtained at the time of pyloromyotomy from 10
patients with IHPS. Control material included 10 pyloric muscle specimens taken
at autopsy from age-matched cases without evidence of gastrointestinal disease.
Indirect immunohistochemistry was performed using the avidin-biotin-peroxidase
complex method with anti-EGF, anti-EGF receptor, and anti-heparin-binding EGF
like growth factor antibody. In situ hybridization was performed using
digoxigenin-labeled EGF-specific oligonucleotide probe. The pattern of
immunoreactivity in pyloric muscle with EGF, EGF receptor, and heparin-binding
EGF-like growth factor was similar in all specimens. There was a marked increase
in EGF, EGF receptor, and heparin-binding EGF-like growth factor immunoreactivity
and EGF mRNA expression in smooth muscle cells in pyloric circular and
longitudinal muscle from patients with IHPS compared with control specimens.
These data suggest that the upregulated local synthesis of EGF and EGF-related
peptides in pyloric muscle may play a critical role in the development of pyloric
muscle hypertrophy in IHPS.
PMID- 10674348
TI - Pharmacokinetics, pharmacodynamics, and safety of administering pegylated
recombinant megakaryocyte growth and development factor to newborn rhesus
monkeys.
AB - Thrombocytopenia is common among sick neonates. Certain groups of
thrombocytopenic adults respond favorably to the administration of recombinant
thrombopoietin or to pegylated recombinant human megakaryocyte growth and
development factor (PEG-rHuMGDF), a recombinant human polypeptide that contains
the receptor-binding N-terminal domain of thrombopoietin. The effectiveness and
safety of such treatment in neonates, however, have not been reported. The
purpose of the present study was to determine the biologic activity and safety of
PEG-rHuMGDF administration to newborn rhesus monkeys. Eight monkeys were divided
into four groups and treated subcutaneously with 0.00, 0.25, 1.00, or 2.50
microg/kg once daily for 7 d. Complete blood counts, serum chemistries, clotting
panels, and MGDF levels were followed serially, and hematopoietic progenitor cell
assays were performed on bone marrow aspirates before the first dose and again on
d 8. Pharmacokinetic evaluations were performed on the animals that received the
highest dose of PEG-rHuMGDF. All monkeys had normal growth during the study
period, and all chemistries, clotting studies, and blood pressure measurements
were normal. The peak serum MGDF concentration occurred at 3 h, and the half-life
was 8.4 to 13.0 h. As in adult rhesus monkeys, platelet counts in the treated
neonates began to rise on d 6, peaked on d 11, and returned to baseline by d 23.
The two highest doses generated an 8- to 12-fold increase in platelets, whereas
those treated with 0.25 microg/kg had a 6-fold increase. Other hematologic
parameters measured were unaffected. Thus, newborn monkeys responded to doses of
PEG-rHuMGDF that were similar to or smaller than (per kilogram body weight) those
that are effective in adult animals and did so without obvious short-term
toxicity.
PMID- 10674349
TI - Influence of maternal smoking on autonomic nervous system in healthy infants.
AB - To determine the influence of maternal smoking on autonomic nervous system in
healthy infants, 36 infants were recorded polygraphically for one night. Their
mothers were defined, according to their smoking frequency during pregnancy, as
"nonsmokers" (no cigarettes smoked during pregnancy) or "smokers" (10 or more
cigarettes per day). The infants had a median postnatal age of 10.5 wk (range 6
to 16 wk); 18 were born to nonsmokers, and 18 to smokers. During the whole night,
spectral analyses of heart rate (HR) were evaluated as a function of sleep
stages. Two major peaks were recognizable: a low-frequency component (LF) related
to sympathetic and parasympathetic activities and a high-frequency component (HF)
reflecting parasympathetic tonus. The ratio of LF/HF powers was calculated as an
index of sympathovagal interaction. In REM sleep, "smokers" infants were
characterized by significantly lower HF powers and normalized HF powers, and
higher LF/HF ratios than "nonsmokers." The finding did not reach statistical
significance in NREM sleep. In conclusion, maternal smoking induced changes in
autonomic control and maturation in infants. These effects of cigarette smoke
exposure can be added to those already reported and offer additional evidence for
counseling mothers to stop smoking.
PMID- 10674350
TI - Total hydroperoxide and advanced oxidation protein products in preterm hypoxic
babies.
AB - Previous studies have shown that plasma lipoproteins are a common target of free
radical-induced oxidative stress in hypoxic newborn infants. In contrast to
lipids, the reaction of proteins with various oxidants during hypoxia has not
been extensively studied. We tested the hypothesis that tissue hypoxia results in
increased production of protein oxidation in cord blood of preterm newborns.
Heparinized blood samples of 39 hypoxic and 16 control preterm newborns were
obtained from the umbilical vein, after cord clamping immediately after delivery.
Plasma levels of total hydroperoxide (TH), advanced oxidation protein products
(AOPP), hypoxanthine (Hx), xanthine (Xa), and uric acid (UA) were measured.
Higher Hx, Xa, UA, TH, and AOPP levels were found in hypoxic newborn infants than
in controls. Statistically significant correlations were observed between: TH and
Hx (r = 0.54, p = 0.003, n = 28), AOPP and Hx (r = 0.64, p = 0.0001, n = 27), and
TH and AOPP plasma levels (r = 0.50, p = 0.02, n = 21). In summary, TH, AOPP, Hx,
Xa, and UA production is increased in fetal blood during hypoxia. The more severe
the hypoxia, the higher the lipid and protein damage by free radicals.
PMID- 10674351
TI - Detection of microorganisms in the tracheal aspirates of preterm infants by
polymerase chain reaction: association of adenovirus infection with
bronchopulmonary dysplasia.
AB - Bronchopulmonary dysplasia (BPD) is recognized as an important cause of morbidity
and mortality in preterm infants. Because the role of congenital infections in
BPD has been debated, the purpose of this study was to test the hypothesis that
detection of infectious agents in tracheal aspirate samples was associated with
the development of BPD. Tracheal aspirate samples were obtained within the 1st
week of life and screened by polymerase chain reaction for adenovirus,
cytomegalovirus, parvovirus, enteroviruses, Ureaplasma urealyticum, Mycoplasma
hominis, Mycoplasma pneumoniae, and Chlamydia species. BPD was defined as
persistent oxygen dependence at 28 d of age and 36 wk postconceptional age (PCA).
Infants that expired before these time points were excluded from statistical
analysis. Out of 89 infants studied, at 28 d of life, 13 had expired, 45 had BPD,
and 31 had no BPD (controls). At 36 wk PCA, 15 infants expired, 39 still had BPD,
and 35 did not. A significant increase in the frequency of adenovirus genome was
identified in BPD patients compared with controls, both at 28 d of life (12/45 =
27% versus 1/31 = 3%: p< or =0.01) and at 36 wk PCA (10/39 = 29% versus 2/35 =
6%: p = 0.01). Other microorganisms were rarely detected and not associated with
the development of BPD. This is the first study reporting the frequency of
detection of adenovirus DNA in tracheal aspirate samples obtained during the 1st
week of life from infants with BPD and suggests that prenatal acquisition may be
important in the development of BPD.
PMID- 10674352
TI - Measurement of baroreceptor-mediated effects on heart rate variability in fetal
sheep.
AB - To determine if alterations in arterial pressure influenced fetal heart rate
variability (HRV), experiments were carried out in chronically catheterized fetal
sheep aged 128-138 d. Arterial pressure was raised or lowered by intravenous
infusion of phenylephrine or sodium nitroprusside, and the effects on heart rate
(HR) and HRV were measured (HRV, as the coefficient of variation (CV) in mean
pulse interval or by power spectral analysis). Experiments were carried out
before and during beta-adrenoceptor blockade with propranolol or before and
during cardiac vagal blockade with atropine. There were positive relationships
between mean arterial pressure and HRV (slope = 0.074+/-0.001, r = 0.81+/-0.06,
p<0.001, measured as the CV of pulse interval) and between mean arterial pressure
and power spectral density (slope = 4+/-0.5, r = 0.89+/-0.02, p<0.001) in the
frequency range 0.04-0.08 Hz. Beta-adrenoceptor blockade had no effect on these
relationships, but they were abolished by cardiac vagal blockade. The sigmoid
relationship between fetal HR and mean arterial pressure, i.e. the cardiac
baroreflex, was affected, however, by blockade of cardiac sympathetics and
abolished by blockade of cardiac vagal activity. Thus, fetal HRV was affected by
alterations in arterial pressure, and these effects depended on the integrity of
the cardiac vagus, not on alterations in cardiac sympathetic activity. Therefore,
although baroreflex control of fetal HR depends on the integrity of both
sympathetic and parasympathetic efferent pathways, baroreceptor-induced changes
in HRV depend only on the cardiac vagus.
PMID- 10674353
TI - Lavage administration of dilute recombinant surfactant in acute lung injury in
piglets.
AB - In an acute lung injury model, we previously observed reversal of pulmonary
dysfunction with natural surfactant administered by lavage (dose = 18 mg/kg
phospholipid). The present study questioned whether a lower dose of phospholipid
would be effective if a recombinant preparation rather than natural surfactant
were used. Acute lung injury was induced by repeated saline lung lavage in
ventilated, sedated, and paralyzed piglets. Three concentrations of recombinant
surfactant were studied (low phospholipid, 1 mg/mL; medium phospholipid, 4 mg/mL;
high phospholipid, 13.5 mg/mL). Control piglets received no surfactant. Thirty
five milliliters per kilogram of surfactant was administered by gravity, followed
by passive drainage of excess fluid. All treatment groups retained similar
volumes (4.7+/-0.3 mL/ kg), corresponding to phospholipid doses of 4+/-0.4, 22+/
3, and 67+/-4 mg/kg in low, medium, and high-dose groups, respectively. Treatment
groups showed significant improvement in Pao2 compared with controls. Other
parameters different from controls were found in only the medium and high-dose
groups. All surfactant-treated groups showed improvement over time in Pao2,
Paco2, lung resistance mean airway pressure, functional residual capacity, and
dynamic compliance. These data support the statement that whereas there is a dose
response to exogenous surfactant, the effective dose of recombinant surfactant in
acute lung injury may be as low as 4 mg/kg phospholipid when administered by
lavage.
PMID- 10674354
TI - IL4 and IL4Ralpha genes are not linked or associated with type 1 diabetes.
AB - Previous studies have shown the immunoregulatory functions IL-4 in type 1
diabetes mellitus. Therefore, the genes involved in the IL-4 regulatory pathway
are candidates for diabetes susceptibility genes. Here we have evaluated IL4 and
the alpha subunit of the IL-4 receptor (IL4Ralpha) genes using the affected
sibpair (ASP) and transmission/disequilibrium test (TDT). We analyzed 309
diabetic families from the United States and 87 families from various European
countries. There was no evidence that either of these two genes are linked or
associated with type 1 diabetes. Means by which IL-4 directed signals could
indirectly alter diabetes susceptibility are proposed.
PMID- 10674355
TI - Growth hormone action in hypothyroid infant rats.
AB - In neonatal rats, expression of serine protease inhibitors 2.1 and 2.3 mRNA peaks
on d 2 of life and declines shortly thereafter, coinciding with levels of
circulating GH. To evaluate the role of GH in this increase and to test the
hypothesis that GH is active in perinatal life, we studied GH action in a model
of GH deficiency. Maternal/neonatal hypothyroidism with consequent GH deficiency
was induced by methimazole administration to pregnant dams. The resultant
hypothyroid neonates were treated at d 2 or 7 of age with GH or saline for 1 h
before exsanguination. In d-7 neonates, but not at d 2, GH administration
resulted in significant serine protease inhibitors 2.1 and 2.3 mRNA induction.
This treatment did not result in increased production of either GH receptor or
IGF-I mRNA at either age. There was a slight GH-independent increase in GH
receptor and IGF-I mRNA expression by d 7. Electromobility shift assays using
hepatic nuclear extracts from these neonates and the GH response element from the
serine protease inhibitor 2.1 promoter showed signal transducer and activator of
transcription 5 (Stat5) binding in response to GH in extracts from d-7 rats only.
Immunoblots of these extracts showed twice as much Stat5 in the nuclei of d-7
treated neonates compared with d-2 treated neonates. We conclude that there is
apparent insensitivity to GH treatment in d-2 neonates that remits by d 7 and
that this remission correlates with increased abundance of GH receptor and Stat5.
PMID- 10674356
TI - Optimization of inspiratory work in periodic breathing in infants.
AB - In periodic breathing, there are repeated cycles of bursts of breaths separated
by pauses several seconds long. We consider the mechanics of periodic breathing
in human infants using calibrated traces of tidal volume and esophageal pressure
recorded during the first few days after delivery. Each cycle of periodic
breathing was analyzed in terms of the inspiratory time and beginning and end
inspiratory volumes for each breath, the number of breaths in the cycle, and the
total observed inspiratory work. A simple model was used to characterize the
mechanics of the lung during inspiration, and the recordings were used to
calculate the parameters of this model. These varied from breath to breath. A
theoretical formula is derived for the sum of external work performed during
inspiration for each burst. It is shown mathematically that there exists a local
minimum in the calculated work as the values of the individual tidal volumes in
this formula are allowed to vary, with the constraint that the sum of the
ventilation during the cycle is as measured. The measured values of inspiratory
timing, the starting volume and pressure, and the mechanical parameters for each
inspiration are also used. We show that during each cycle of periodic breathing,
the total of the observed external work is highly correlated with this
theoretical minimum work. In addition, during the cycle, there is a pattern of
overshoot and subsequent undershoot in the work with respect to the theoretical
optimum, which suggests a control process operating during the cycle to minimize
the work.
PMID- 10674357
TI - Expression of gamma-glutamylcysteine synthetase during development.
AB - Prematurity has been associated with low glutathione (GSH) concentrations in
bronchoalveolar lavage fluid as well as in leukocytes from tracheal aspirates and
peripheral blood. To elucidate whether this is caused by deficient GSH synthesis,
the expression and activity of gamma-glutamylcysteine synthetase (glutamate
cysteine ligase, GCS, EC 6.3.2.2), the rate-limiting enzyme for GSH synthesis,
were measured from fetal, neonatal, and adult human liver, lung, and kidney
samples. The highest activity was measured in the liver, in which mRNA expression
of the catalytic GCS heavy and the regulatory light subunits, as well as
activity, were, on average, similar in the various stages of development.
Although GCS light subunit mRNA concentrations in the lung were higher in
neonates than in fetuses and adults, enzyme activities were similar. In the adult
kidney, mean enzyme activity was somewhat higher than in fetal or neonatal
kidney, but this may be accounted for by the variation in the small number of
samples. In conclusion, GCS is expressed and active already in the second
trimester and thus low GSH concentrations found in preterm neonates appear not to
be explained by deficient GSH synthesis. Other factors, such as limited
availability of the GSH precursor cysteine or increased GSH consumption, may
account for the lower concentrations of GSH found in preterm infants.
PMID- 10674358
TI - Formation of L-alloisoleucine in vivo: an L-[13C]isoleucine study in man.
AB - L-alloisoleucine (2S, 3R), a diastereomer of L-isoleucine (2S, 3S), is a normal
constituent of human plasma. Considerable amounts accumulate in maple syrup urine
disease, in which the branched-chain 2-oxo acid dehydrogenase step is impaired.
The mechanism of L-alloisoleucine formation, however, is unclear. We addressed
this issue by performing oral L-[1-13C]isoleucine loading (38 micromol/kg body
wt, 50% 1-13C) in overnight-fasted healthy subjects (n = 4) and measuring the 3-h
kinetics of 13C-label incorporation into L-isoleucine plasma metabolites.
Compared with L-isoleucine, the time course of 13C-enrichment in the related 2
oxo acid, S-3-methyl-2-oxopentanoate, was only slightly delayed. Peak values,
amounting to 18+/-4 and 17+/-3 mol percent excess, respectively, were reached
within 35 and 45 min, respectively. The kinetics of 13C-enrichment in S- and R-3
methyl-2-oxopentanoate enantiomorphs were similar and linearly correlated (p <<
0.001). In L-alloisoleucine, however, 13C-label accumulated only gradually and in
minor amounts. Our results indicate that R-3-methyl-2-oxopentanoate is an
immediate and inevitable byproduct of L-isoleucine transamination and further
suggest that alloisoleucine is primarily formed via retransamination of 3-methyl
2-oxopenanoate in vivo.
PMID- 10674360
TI - Neuroimaging of hallucinations: a review of the literature.
AB - While hallucinations have been described for over two millennia, their cause
remains unclear. Brain-based models suggest that abnormal cerebral excitation and
a lack of normal cerebral inhibition may play primary roles, but evaluation of
these hypotheses has been hampered by difficulty in studying the hallucinatory
state. Recent advances in neuroimaging have provided researchers with tools to
study a variety of mental states, including hallucinations. We review the
literature regarding the structural and functional neural correlates of
hallucinations. Despite small sample sizes and methodological differences,
several studies describe similar results: hallucinations are associated with
sensory modality-specific activation in cerebral areas involved in normal sensory
processing. Furthermore, neural activation may be specifically related to
distinct phenomenological features of the hallucinatory experience. Further work
is needed to better understand the neural basis of hallucinations.
PMID- 10674359
TI - Dietary trans fatty acids affect docosahexaenoic acid concentrations in plasma
and liver but not brain of pregnant and fetal rats.
AB - The aim of the present study was to investigate the maternal-fetal transport,
incorporation, and effects on liver delta-6 fatty-acid desaturase activity of
dietary trans fatty acids in pregnant rats. Three groups of six rats each were
fed three experimental diets containing approximately 0%, 15%, and 30% of trans
fatty acids but containing the same proportion of linoleic (18:2 n-6) and a
linolenic (18:3 n-3) acids for 10 wk. On d 20 of pregnancy, the animals from each
group were killed. We determined the fatty acid profiles in plasma, brain, and
liver microsomes of pregnant rats, as well as in placenta and fetal liver and
brain. No changes were found in the number of fetuses of the pregnant rats. Trans
fatty acids were incorporated in high concentrations in placenta and in maternal
and fetal tissues, except brain, strongly elevating the linoleic acid proportion
and lowering that of docosahexaenoic acid. The delta-6 fatty-acid desaturase
activity in the liver microsomes of the pregnant rats was inhibited by trans
isomers. In conclusion, high intakes of trans fatty acids partially inhibit liver
delta-6 fatty-acid desaturase in pregnant rats, which may explain, in part, the
low concentrations of docosahexaenoic acid in pregnant and fetal tissues.
However, the fatty acid composition of both fetal and pregnant rat brain remains
mostly unaffected regardless of the dietary trans fatty acid content.
PMID- 10674361
TI - Neo-striatal rCBF correlates of psychomotor slowing in patients with major
depression.
AB - Psychomotor slowing is a fundamental clinical feature of severe depression and is
thought to reflect dysfunction within prefrontal-subcortical circuits. This study
utilised a split-dose single photon emission computerised tomography (SPECT)
scanning technique in association with a two-stage test of psychomotor speed.
Twenty-five patients with primary depressive disorders were injected with
technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) whilst performing
each component of a two-stage psychomotor task. The first stage, 'simple reaction
time' (RT) and the second stage, 'choice reaction time' (CRT), were each followed
by 30-min SPECT scans. Regions of interest (ROIs) corresponding to the left and
right neo-striatum (caudate-putamen) were drawn, and regional cerebral blood flow
(rCBF) values were calculated. Importantly, the change in rCBF measure in the
left neo-striatum was inversely correlated with RT (r = -0.48, P < 0.05). That
is, the patients with the greatest psychomotor slowing initially showed the least
increase in rCBF during the CRT condition. This effect was independent of age.
The study demonstrates that a simple two-stage motor paradigm can be used to
elicit rCBF correlates of psychomotor slowing in patients with primary
depression. Such rCBF findings may implicate the neo-striatum in the neurobiology
of major depression.
PMID- 10674362
TI - Proton magnetic resonance spectroscopy of lenticular nuclei in obsessive
compulsive disorder.
AB - Magnetic resonance spectroscopy (MRS) is a safe and non-invasive technique for
the in vivo study of brain chemistry and metabolism. As such, it is highly
applicable to the study of living brain tissue in psychiatric diseases. Several
neuropathological and neuroimaging studies have suggested that abnormalities of
the basal ganglia nuclei might be implicated in patients with obsessive
compulsive disorder (OCD). In the present study, we performed proton [1H]MRS of
the lenticular nuclei in 12 patients with OCD and 12 healthy normal comparison
subjects. The peaks of N-acetyl-aspartate (NAA), creatine (Cr), and choline
containing compounds (Cho) were measured. No differences between OCD patients and
normal subjects were found in the NAA/Cr, Cho/Cr and NAA/Cho ratios. Our results
suggest the normal viability of neuronal cells, as indicated by the
quantification of NAA, Cr and Cho in the lenticular nuclei of patients with OCD.
PMID- 10674363
TI - Spontaneous oscillations of cerebral blood flow velocity in the middle cerebral
arteries of normal subjects and schizophrenic patients.
AB - Although many regional cerebral blood flow (rCBF) studies of schizophrenic
patients have been carried out, only a few studies have investigated real-time
hemodynamic changes in schizophrenic patients. In the present study, we used long
term monitoring of the middle cerebral artery (MCA) by non-invasive transcranial
Doppler ultrasonography to obtain real-time CBF data in 55 schizophrenic patients
and 20 normal comparison subjects. The mean blood flow velocity and pulsatility
index (PI) of the MCA were not constant during long-term monitoring. They showed
sinusoidal oscillations similar to those described in previous reports. The
amplitude variations of these oscillations in both drug-naive and medicated
schizophrenic patients were significantly decreased compared with findings in
normal control subjects. The averaged PI values were found to be decreased in
patients with illness durations of more than 10 years. After withdrawal of
antipsychotic medication, both the amplitude variations of oscillations and the
PI values in the drug-withdrawn patients were significantly decreased relative to
findings in normal control subjects. Our results show a decreased adjustment
ability of cerebral vessel resistance not only in neuroleptic-naive schizophrenic
patients but also in patients with longer illness duration. Neuroleptics could
affect the adjustment ability of vessel resistance.
PMID- 10674364
TI - Reliability and validity of ratings of signal hyperintensities on MRI by visual
inspection and computerised measurement.
AB - Brain magnetic resonance imaging (MRI) scans on 98 elderly subjects, 62 with a
diagnosis of schizophrenia and 36 healthy controls, were independently and
blindly rated by two investigators using the visual rating methods of Fazekas et
al. (Fazekas, F., Chawluk, J.B., Alavi, A., Hurtig, H.I., Zimmerman, R.A., 1987.
MR signal abnormalities at 1.5 T in Alzheimer's dementia and normal aging.
American Journal of Neuroradiology 8, 421-426) and Victoroff et al. (Victoroff,
J., Mack, W.J., Grafton, S.T., Schreiber, S.S., Chui, H.C., 1994. A method to
improve interrater reliability of visual inspection of brain MRI scans in
dementia. Neurology 44, 2267-2276) for periventricular, deep white matter and
subcortical gray matter signal hyperintensities (SHs) on T2-weighted images. The
hyperintense signal volumes were measured by manual delineation of the signals on
a workstation using Analyze software (computerised method). The subjects also
underwent a detailed neuropsychological assessment. There was a high correlation
between two experienced raters for both visual ratings, and the correspondence
between the two methods was high. The inter-rater reliability for the
computerised method was modest but significant, and the association between the
visual and computerised methods was good except for ratings for SHs in
subcortical nuclei. The Fazekas and computerised methods, and to a lesser degree
the Victoroff method, had modest but significant correlations with some
neuropsychological test measures. In conclusion, we did not demonstrate a clear
superiority in reliability or validity for one demanding computerised method of
rating SHs. Visual ratings should therefore be considered adequate for most
clinical and research purposes, but such ratings should be accompanied by
adequate training and the provision of standard reference images.
PMID- 10674365
TI - Summary of the Third International Research Workshop on Alopecia Areata.
PMID- 10674366
TI - Spontaneous alopecia areata-like hair loss in one congenic and seven inbred
laboratory mouse strains.
AB - Alopecia areata (AA) research has been hampered by the lack of suitable animal
models for use in experimental procedures. AA-like hair loss has been observed in
several species, including dogs, cats, horses, cattle, and nonhuman primates;
however, these examples are isolated cases in outbred species of large size,
limiting their use in AA research. Inbred rodent strains are ideal research
models. C3H/HeJ mice can develop spontaneous AA-like hair loss and have
previously been advanced as a suitable experimental model. The search for
additional mouse strains with AA-like hair loss has continued. Nonscarring,
inflammatory, spontaneously reversible hair loss has been observed in individual
mice from several inbred mouse strains. Aside from C3H/HeJ mice, an AA-like
phenotype has been observed in the substrain C3H/HeJBir, with an expression
frequency of 5%. Up to 10% of individuals in an A/J mouse colony have been
confirmed to develop patchy AA-like hair loss. Isolated examples of AA have also
been identified in C3H/HeN/J mice, C3H/OuJ mice, HRS/J+/hr heterozygous normal
mice, CBA/CaHN-Btk(xid)/J mice, and BALB.2R-H2h2/Lil mice, each with a colony
frequency of less than 1%. BALB.2R-H2h2/Lil mice may also have severe nail
defects. AA is regarded as rare in nonhuman species; however, nonscarring
inflammatory based alopecia has been identified in several mouse strains. These
examples may represent different subtypes of the heterogeneous AA phenotype.
Pathologic and genetic analysis of different AA affected mouse strains may
contribute to understanding AA pathogenesis and elucidating susceptibility genes.
PMID- 10674367
TI - Alopecia areata is a T-lymphocyte mediated autoimmune disease: lesional human T
lymphocytes transfer alopecia areata to human skin grafts on SCID mice.
AB - Much evidence suggests that alopecia areata is a tissue restricted autoimmune
disease. Alopecia areata responds to immunosuppressive agents, and is associated
with other tissue restricted autoimmune diseases, including autoimmune
thyroiditis and vitiligo. Furthermore, hair regrows when involved scalp is
transplanted to nude mice. This study was undertaken to determine whether
alopecia areata is mediated by T lymphocytes. Involved scalp from alopecia areata
patients was grafted onto SCID mice. Additional biopsies from lesional scalp of
the same patients were used to isolate T lymphocytes. These T lymphocytes were
cultured with hair follicle homogenate, as well as autologous antigen presenting
cells. The T lymphocytes were then injected into autologous scalp grafts on the
SCID mice, which had regrown hair. Injection of scalp T lymphocytes resulted in
hair loss. Hair loss was associated with the histologic and immunochemical
changes of alopecia areata, including perifollicular infiltrates of T cells,
along with HLA-DR and ICAM-1 expression by the follicular epithelium. Scalp T
lymphocytes that had not been cultured with hair follicle homogenate did not have
this effect. Preliminary data suggests hair loss requires a collaboration between
CD8+ and CD4+T cells. These studies have demonstrated that alopecia areata can be
induced by the transfer of T cells that recognize a hair follicle autoantigen.
PMID- 10674368
TI - Alopecia areata and universalis in the Smyth chicken model for spontaneous
autoimmune vitiligo.
AB - The Smyth line (SL) chicken model for spontaneous, postnatal expression of
vitiligo may also show varying incidences and degrees of severity ranging from
alopecia areata-like to universalis-like integumental changes. Although human
vitiligo patients are known to have a four times greater chance of having
alopecia areata than do people without vitiligo, in the SL model, feather loss is
limited to birds that show some degree of amelanosis of feather and skin tissue.
Both the vitiligo and the alopecia have an autoimmune component, as shown by
histologic and immunologic studies, including the correctional influences of
corticosterone and cyclosporine-A. The major histocompatibility haplotype (MHC)
has a major effect on the incidence and expression of the vitiligo, as well as
the alopecia that occurs within vitiliginous birds. Three different MHC
haplotypes were identified in the original line that was selected for vitiligo,
and from these, three sublines were developed, each homozygous for a different
haplotype. Of the three sublines (SL101, SL102, and SL103) the vitiligo has a
significantly earlier onset and severity in the SL101 than in the other two
lines. The incidence of alopecia, however, is significantly lower in the SL101
subline than in the other two. Inheritance of the vitiligo is polygenic with an
additional genetic component for the alopecia trait. It is hypothesized, but as
yet unproven, that a feather development defect interacts with the SL
melanization and immunologic defects to initiate the partial (areata) and
complete (universalis) alopecias. The alopecia universalis is rarely seen until
adulthood and is characterized by short (<0.5 cm), undeveloped feathers. If
feather growth resumes in these birds, the feathers dry up, cease to grow, and
often break off.
PMID- 10674369
TI - The genetic basis of alopecia areata: HLA associations with patchy alopecia
areata versus alopecia totalis and alopecia universalis.
AB - Many diseases, notably those having a strong autoimmune component, have been
shown to have an association with specific human leukocyte antigens (HLA). The
molecular basis for this genetic association with disease is the fact that HLA
bind and present peptides derived from self and foreign protein antigens to the
immune system for recognition and activation of the immune response. Previous
studies with heterogeneous groups of alopecia areata (AA) patients have suggested
associations with some HLA class I and class II antigens. For this study we
selected only patients with long-standing disease and stratified them into two
groups by strict definitions of duration and extent of disease: those with patchy
AA and those with either alopecia totalis (AT) or alopecia universalis (AU). The
patients were tissue typed for HLA class II antigens by biomolecular methods that
provided antigen discrimination at an allele level. More than 80% of all of the
AA patients typed were positive for the antigen DQB1*03 (DQ3), suggesting that
this antigen is a marker for general susceptibility to AA. In addition, two other
antigens were found significantly increased in frequency only in the group of
AT/AU patients, DRB1*0401 (DR4) and DQB1*0301(DQ7). This strongly suggests that
the two clinical types of AA, namely patchy AA versus AT/AU, can be distinguished
by a genetically based predisposition to extent of disease.
PMID- 10674370
TI - Alopecia areata in families: association with the HLA locus.
AB - Alopecia areata (AA) is a T cell mediated disease directed against hair follicles
that results in bald patches. It can range in severity from patchy (AA), to total
scalp hair loss (alopecia totalis; AT) or body hair loss (alopecia universalis;
AU). We have previously shown that HLA-DR4 and DR11 as well as HLA-DQ*03 alleles
are increased in unrelated AA patients compared with controls. To study whether
class II HLA alleles are linked to AA, we investigated 81 extended families that
included 192 AA patients, including 89 with AT or AU. We also performed the
transmission disequilibrium test (TDT) in 143 nuclear families. Results showed an
association between alleles of HLA-DQB (p = 0.014) and HLA-DR (p = 0.010). We
also performed linkage analysis in 75 families whose members' genomic DNA were
available for HLA typing. Results from this analysis support linkage between AA
and class II loci with a maximal LOD score of 2.42 to HLA-DQB at 5%
recombination, and with a maximal LOD score of 2.34 to HLA-DR at 0%
recombination. There was an increased incidence of atopic dermatitis and
autoimmune thyroiditis in families. AA appears to be a class II HLA restricted
organ specific immune response to the hair follicle.
PMID- 10674371
TI - T cell repertoire in mice with alopecia areata.
AB - It has become clear that skin infiltrating autoreactive CD4+ T helper cells play
a crucial role in the initiation of alopecia areata. However, the natures of the
pathogenic T cell clones as well as of the skin antigen they recognize remain
obscure. Here, we analyzed the T cell receptor repertoire expressed in the spleen
of diseased mice. We consistently observed the dominant expansion of a limited
set of T cell clones expressing Vbeta8.2/Jbeta2.5 T cell receptor rearrangement.
We conclude that T cell response in mice alopecia areata is markedly oligoclonal;
a feature that may permit the design of selective immunotherapy.
PMID- 10674372
TI - Immunology of the hair follicle: a short journey into terra incognita.
AB - This paper delineates briefly why the immunology of the hair follicle matters
(e.g., anti-infection defense, hair growth control by immunomodulatory agents,
sequestration of follicular autoantigens), and which open key questions await
clarification. We then focus on the murine hair follicle immune system (HIS) and
its immune privilege. We show how the murine HIS is gradually constructed during
hair follicle morphogenesis, and how it is transformed during hair follicle
cycling. Key characteristics of the HIS are summarized, such as the absence of
MHC class I expression in the anagen hair bulb and the very restricted
distribution of antigen-presenting cells and intraepithelial T cells to the
distal outer root sheath, which also expresses nonclassical MHC class Ib
molecules. The interconnections between the HIS and the skin immune system (SIS)
and potential hair growth-modulatory roles of mast cells and macrophages are
addressed, and very recent findings on the human HIS are summarized. The paper
closes by sketching immunobiologic, clinical, and pharmacologic perspectives in
trichoimmunology that deserve the attention of immunologists, dermatologists, and
hair biologists alike.
PMID- 10674373
TI - The potential role of cytokines and T cells in alopecia areata.
AB - T cells play an important role in alopecia areata (AA) because AA can be
reinduced by the injection of hair follicle-specific CD8+ T cells into AA scalp
biopsies, which were grafted onto scid mice, and the depletion of CD8+ T cells
restores hair growth in the Dundee experimental bald rat. Moreover, AA can be
transferred by grafting of alopecic skin from C3H/HeJ mice with AA-like hair loss
onto unaffected littermates, but the onset of AA is inhibited by i.p. injection
of anti-CD44v10 antibodies. Interestingly, grafted anti-CD44v10-treated mice have
decreased numbers of CD8+ T cells within the skin. Beside T cells several
clinical and experimental data point towards cytokines that might be crucial
inducers of hair loss in AA. An aberrant expression of cytokines of the Thl type
and IL-1beta has been detected in scalp areas involved by AA, and polymorphisms
of cytokine genes such as IL-1-receptor antagonist, IL-1alpha, and TNF-alpha have
been shown to determine disease susceptibility and severity. Moreover, IL-1 has
been shown to be a potent inhibitor of human hair growth in vitro. Such IL-1
incubated hair follicles show ultrastructural changes similar to those observable
in vivo. On the other hand mice transgenic for IL-1alpha develop patchy hair loss
and during the depilation-induced hair cycle in C57/BL6 mice, members of the IL-1
family are overexpressed with the onset of spontaneous catagen. Taking all of the
presently available data together, we may hypothesize that CD8+ T cells are of
crucial importance in AA by their interaction with MHC-I restricted autoantigens,
and cytolysis of their target cells. Hair loss, however, may occur because
proinflammatory cytokines may interfere with the hair cycle leading to premature
arrest of hair cycling.
PMID- 10674374
TI - Alopecia areata-like hair loss in C3H/HeJ mice and DEBR rats can be reversed
using topical diphencyprone.
AB - This study demonstrates the ability to treat successfully alopecia areata-like
hair loss in both mouse and rat models using topical immunotherapy with
diphencyprone.
PMID- 10674375
TI - The molecular basis of congenital atrichia in humans and mice: mutations in the
hairless gene.
AB - Congenital atrichia is a form of total alopecia inherited in an autosomal
recessive pattern. In individuals affected with this form of hair loss, hairs are
typically absent from the scalp, and patients are nearly completely devoid of
eyebrows, eyelashes, axillary and pubic hair, following shedding of the natural
hair shortly after birth. We have recently linked this disorder to the
chromosomal region 8p12, and cloned the human hairless gene, which resides within
this interval. We have identified several mutations in the hairless gene in
atrichia families from around the world. In hairless mice, the hair matrix cells
appear to undergo a premature and massive apoptosis, together with a concomitant
decline in Bcl-2 expression, a loss of NCAM positivity, and a disconnection with
the overlying epithelial sheath essential for the movement of the dermal papilla.
As a consequence, the hair bulb and dermal papilla remain stranded in the dermis,
and indispensible messages between the dermal papilla and stem cells in the bulge
are not transmitted, so no further hair growth occurs. These findings suggest
that the hairless gene product may play a crucial role in maintaining the
delicate balance between cell proliferation, differentiation and apoptosis in the
hair follicle, as well as in the interfollicular epidermis.
PMID- 10674376
TI - Hair defects in Hoxc13 mutant mice.
AB - Hox genes encode transcription factors that are important during normal embryonic
development of diverse organisms including vertebrates. In mammals, Hox genes are
responsible for conferring regional identity in embryonic tissues, including the
limb bud, the neural tube, the presomitic mesoderm and the intestinal tract.
Recent studies have demonstrated expression of Hox genes in skin and hair
follicles, suggesting potential functions for these genes in epidermal
appendages. These studies are reviewed here with emphasis on Hoxc13, as Hoxc13
mutants are the first Hox mutants to demonstrate overt hair defects. In addition,
because Hoxc13 does not show regionally restricted expression in the skin, as
demonstrated for other Hox genes, the potentially different roles of Hoxc13
versus other Hox genes in the skin are discussed.
PMID- 10674377
TI - The presence of loose anagen hairs obtained by hair pull in the normal
population.
AB - To help determine the specificity of "loose anagen" (LA) hairs in Loose Anagen
Syndrome, the presence or absence of LA hairs on a gentle but firm hair pull was
evaluated in 110 normal subjects from a 0.5 to 83 y old. In children < or =10 y
old, 61% had LA hairs on hair pull evaluation and 73% of all hairs obtained were
LA hairs. In contrast, LA hairs were found in only two of 87 (2%) normal
postpubescent subjects. The number of LA hairs was small in normal children (1-2
per hair pull) and a maximum of one out of every 6-7 hair pulls in adults, far
less than that reported with Loose Anagen Syndrome. Although the mere presence of
LA hairs on a hair pull test is thus not specific for LAS in children, the number
per hair pull may have diagnostic significance. Correlation of these findings
with the various hair disorder phenotypes currently termed Loose Anagen Syndrome
will be important.
PMID- 10674378
TI - Marie Unna congenital hypotrichosis: clinical description, histopathology,
scanning electron microscopy of a previously unreported large pedigree.
AB - Marie Unna congenital hypotrichosis (MUCH) is a rare autosomal dominant condition
in which abnormalities are confined to hair shaft structure and hair density. We
report a six-generation pedigree consisting of 59 members of whom 16 are
affected; nine identified affected individuals are living. Affected individuals
are born with adequate, normal to coarse hair. During early infancy the scalp
hair becomes more coarse and wiry and stands out from the head. All affected
individuals have sparse to absent eyebrows, eyelashes and body hair including
secondary sexual hair. In some individuals, scalp hair is progressively lost
beginning at puberty or beyond, until only a sparse fringe in the tonsorial
distribution remains. The hair shafts are uniformly increased in diameter,
measuring up to 0.12 mm. Individual hair shafts are deeply pigmented, variable in
diameter, twisted, and bent at odd angles; some have a longitudinal groove
visible on scanning electron microscopy. Cross-sectional shapes are variable and
irregular, exhibiting oval, angular to reniform shapes. Multiple anagen hairs are
extractable on gentle hair pull. Other ectodermal structures are unaffected
except for exceptionally widely spaced upper incisor teeth seen in 50% of
affected individuals. Histologically, there are dramatically reduced numbers of
follicles per unit area, averaging nine total hairs per 4 mm cross-section as
compared with a normal of 40. A mild to moderate inflammatory infiltrate is
present, but little fibrosis and no scarring. The mechanism of progressive hair
loss is unknown.
PMID- 10674379
TI - Trichodysplasia spinulosa--a newly described folliculocentric viral infection in
an immunocompromised host.
AB - This is a case report of an immunocompromised individual who presented with
progressive alopecia, friable follicular spinous processes, and erythematous,
indurated papules. Examination of skin biopsies using light microscopy and
immunohistochemistry revealed pathologic changes of the follicular inner root
sheath epithelium with dystrophic trichohyaline granules. Electron microscopy of
thin sections of tissue revealed intracellular viral particles with a size and
appearance consistent with those in the Papovaviridae family. Electron microscopy
of negatively stained extract from a homogenized lesion also demonstrated
icosahedral viruses with papovavirus morphology. We believe this is a previously
unreported folliculocentric viral infection in an immunosuppressed human host and
have termed this entity "trichodysplasia spinulosa".
PMID- 10674380
TI - Hair follicle apoptosis and Bcl-2.
AB - Hair follicle (HF) morphogenesis and cycling are characterized by a tightly
controlled balance of proliferation, differentiation and apoptosis. The members
of the bcl-2 family of proto-oncogenes are important key players in the apoptosis
control machinery of most cell types. Bcl-2, an apoptosis inhibitor, and Bax, an
apoptosis promoter, show tightly regulated, hair cycle-dependent expression
patterns: during catagen, the distal ORS of the HF remains strongly positive for
Bcl-2 and Bax; in contrast, the proximal epithelial part of the HF loses most Bcl
2 expression while it remains strongly positive for Bax. In Bcl-2 null mice, skin
becomes markedly hypopigmented during the first postnatal anagen probably due to
increased melanocyte apoptosis. Reportedly, these mice also show a retardation of
the first anagen development after birth. Transgenic mice overexpressing Bcl-2
under the control of the keratin-1 promoter display multifocal epidermal
hyperplasia and aberrant expression of keratin-6, while alterations of HF cycling
have not been investigated. Surprisingly, Bcl-2 overexpression under the control
of the keratin-14 promoter leads to accelerated catagen progression and increased
chemotherapy-induced apoptosis, HF dystrophy and alopecia. Transgenic mice
overexpressing Bcl-X(L), another anti-apoptotic bcl-2 family member, under the
control of the K14 promoter, reportedly also display accelerated catagen
development. These and other Bcl-2 transgenic and null mice are now available to
further dissect the as yet unclear, and likely complex, role of Bcl-2 in HF
growth and pigmentation.
PMID- 10674381
TI - Msx-2 and the regulation of organ size: epidermal thickness and hair length.
AB - During organogenesis, the issue of size regulation is as important as shape and
differentiation. We propose that the regulation of the dimensions of the
epithelium and its appendages (length, width, thickness) are based on regulation
of cell numbers in specific sites, reflecting the input and output of cells in
that region. This process is in turn regulated by the flow from the domain of
proliferating cells to the domain of postmitotic differentiated cells. When the
homeobox gene Msx-2 is over-expressed in transgenic mice under the control of the
CMV promoter, the epidermis is thickened with hyperproliferation and
hyperkeratosis. Hairs are shorter and the matrix region is shrunken. We suggest
that Msx-2 may be one of the regulators involved in the control of organ size,
and the above phenotypes are the manifestations of an increased cellular flow
from proliferation domain to differentiation domain in the tissue.
PMID- 10674382
TI - Measuring reversal of hair miniaturization in androgenetic alopecia by follicular
counts in horizontal sections of serial scalp biopsies: results of finasteride 1
mg treatment of men and postmenopausal women.
AB - Hair regrowth was evaluated by histologic analysis in men and women treated for
androgenetic alopecia, by counting follicles in horizontal sections of scalp
biopsies. Serial 4mm punch biopsies were taken at baseline and after 12mo of
treatment from the transitional area of hair thinning between normal hair and
vertex balding in men, and in an area of frontal/parietal thinning in women.
Horizontal sections of reticular and papillary dermis were read by one observer,
blinded to patient, treatment, and time. All terminal hair bulbs, terminal anagen
and telogen hairs, and vellus and vellus-like miniaturized hairs were counted.
Twenty-six men aged 18-41y, comprising 14 on finasteride 1 mg daily and 12 on
placebo, and 94 postmenopausal women, aged 41-60y, comprising 44 on finasteride 1
mg daily and 50 on placebo, were evaluated. In the male study, the terminal hairs
increased from a mean baseline count of 15.5-20.9 after 12mo of finasteride,
versus 17.3-18.3 in the placebo patients. The miniaturized hairs decreased from
26.7 to 23.6 with finasteride versus 21.3-20.3 with placebo. The terminal-to
vellus ratio increased more in the finasteride than in the placebo patients,
suggesting some reversal of the miniaturization process with finasteride. In the
female study, no significant differences in follicular counts were found between
the finasteride and placebo groups after 12mo of treatment. Follicular counts in
horizontal sections provide an informative adjunct to noninvasive measures used
in hair growth studies. Finasteride appears to be capable of reversing hair
miniaturization in androgenetic alopecia in young to middle-aged men, but not in
postmenopausal women.
PMID- 10674383
TI - Effects of 17-beta-estradiol and ICI 182 780 on hair growth in various strains of
mice.
AB - 17-beta-Estradiol (10 nmol per 200 microl acetone) applied topically twice weekly
to the clipped dorsal surface of C57BL/6 or C3H female mouse skin prevented hair
growth, as previously described in the CD-1 mouse strain. Twice weekly topical
application of the estrogen receptor antagonist, ICI 182 780 (10nmol per
200microl acetone), induced the telogenanagen transition and produced early
pigmentation appearance in skin and hair growth in C57BL/6 and C3H female mice.
Whereas twice weekly topical application of 10nmol 17-beta-estradiol blocked hair
growth, the intraperitoneal administration of this dose twice weekly did not
block hair growth, suggesting a direct cutaneous effect of 17-beta-estradiol. We
also evaluated the effect of 17-alpha-estradiol, 17-beta-estradiol, and ICI 182
780 on hair growth in male mice. As observed in female mice, 17-beta-estradiol
was a potent inhibitor of hair growth and ICI 182 780 stimulated hair growth;
however, unlike the results previously observed in female mice, 17-alpha
estradiol was a potent inhibitor of hair growth in male mice. These results
demonstrate that (i) the route of administration of 17-beta-estradiol is critical
for its ability to block hair growth; (ii) C57BL/6 and C3H mice, two commonly
employed mouse strains for hair growth studies, responded to 17-beta-estradiol
and ICI 182 780 in a manner similar to that described in CD-1 mice; and (iii) the
hair follicles of male and female mice respond similarly to 17-beta-estradiol and
ICI 182 780, but display striking sex differences in the response to 17-alpha
estradiol on hair growth.
PMID- 10674384
TI - In vitro main pathways of steroid action in cultured hair follicle cells:
vascular approach.
AB - The known role of steroids on the hair follicle leads us to investigate their
effects on hair follicle cell angiogenic responses in vitro. We verified, using
the immunohistochemical technique, whether human occipital scalp follicle cells
express steroid receptors in vitro. We showed that androgen and estrogen
receptors were expressed by dermal papilla cells (DPC) and keratinocytes from the
outer root sheath in vitro. With regard to steroidal enzymes (type I and II
5alpha-reductases and Cytochrome-p-450-aromatase), the type I 5alpha-reductase
gene is much more expressed in DPC than in dermal fibroblasts; however, the type
II 5a-reductase gene is transcribed more in dermal fibroblasts than in DPC. The
transcription of the two 5alpha-reductase isoform genes in cultured DPC is
regulated by a 5alpha-reductase inhibitor. We also demonstrated that DPC, dermal
fibroblasts, and outer root shealth keratinocytes expressed cytochrome-p-450
aromatase. Using ELISA and reverse transcriptase-polymerase chain reaction, we
investigated the role played by some steroids (estrogens, androgens,
antiandrogens) in the modulation of vascular endothelial growth factor (VEGF)
expression by DPC. The association of different treatments of DPC (5alpha
reductase inhibitor and androgen receptor antagonist) shows a great stimulation
of VEGF and aromatase expression. Strong stimulation of VEGF protein and gene
expression is observed in the presence of 17beta-estradiol. Also, the
concentration-dependent inhibition of VEGF expression by DPC using the cytochrome
p-450-aromatase inhibitor, confirms the involvement of this estrogenic pathway in
the regulation of VEGF expression in vitro.
PMID- 10674385
TI - Human hair follicle bulge cells are biochemically distinct and possess an
epithelial stem cell phenotype.
AB - Stem cells are vital for the homeostasis of self-renewing tissues and their
manipulation may have wide ranging applications, including gene therapy, wound
repair, and tissue transplantation. Although rodent hair follicle stem cells have
been localized to the follicle bulge, the location of human hair follicle stem
cells is less clear, and their characterization has been hampered by a lack of
cellular markers for the bulge area. We demonstrate that the C8/144B monoclonal
antibody, originally raised against a CD8 peptide sequence, immunostains the
human hair follicle bulge. We show that this antibody recognizes cytokeratin 15
(K15) in keratinocytes, and that K15-positive bulge cells possess a stem cell
phenotype characterized by their slowly cycling nature, proliferation at the
onset of new hair follicle growth, and high level of beta1 integrin expression.
These results localize human hair follicle stem cells to the bulge and suggest
that K15 is preferentially expressed in epithelial stem cells.
PMID- 10674386
TI - Early events in skin appendage formation: induction of epithelial placodes and
condensation of dermal mesenchyme.
AB - The formation of skin appendages represents a morphogenetic process through which
a homogeneous system is converted into a patterned system. We have pursued
molecules involved in the early placode induction and mesenchymal condensation
stages of this process. We found that intracellular and extracellular signaling
molecules collaborate to position the location of feather primordia and initiate
mesenchymal condensations mediated by adhesion molecules. During the inductive
stage, cells interact in a fashion best described by a reaction-diffusion
mechanism. Thus in early feather morphogenesis, low level adhesion molecules
drive cell interactions. The interactions were modulated by extracellular
signaling molecules, which eventually increase the level of signaling molecules
at sites of feather initiation and subsequently the level of adhesion molecules
(Jiang et al, 1999a). These physico-chemical events lead to the formation of
dermal condensations and epithelial placodes at sites of feather primordia, thus
achieving the earliest and most fundamental events of skin appendage formation:
induction.
PMID- 10674387
TI - Phenotypic determination of epithelial appendages: genes, developmental pathways,
and evolution.
AB - Epithelial appendages are derivatives of epithelia that elaborate to form
specialized structures and functions. The appendage can protrude out, such as in
teeth and feathers, or invaginate in, such as in glands. The epithelia can be
ectodermal, such as in hairs, or endodermal, such as in livers. Using feather as
a prototype of epithelial appendage, we study the molecular signals involved in
the successive stages of epithelial-mesenchymal interactions during
morphogenesis. We propose that these form the basics of gene networks, which can
be integrated to gene supernetwork and totinetwork. Because the unit of
development is molecular pathway rather than single molecule, and the unit of
morphogenesis is cell group rather than single cell, we make the analogy between
genes/developmental pathways and words/sentences. The study of developmental
pathways in epithelial appendage organogenesis will help us to understand the
grammar of genes and the basic rules in constructing regulated new growth. This
knowledge may contribute to the study of cancer biology (deregulated new growth)
and organ regeneration.
PMID- 10674388
TI - Hair cycle-dependent expression of hepatocyte growth factor (HGF) activator,
other proteinases, and proteinase inhibitors correlates with the expression of
HGF in rat hair follicles.
AB - We previously reported that hepatocyte growth factor (HGF) had a stimulatory
effect on hair growth in vivo and in vitro. The secreted inactive form of HGF is
processed into an active form by serine proteinases such as HGF activator and
urokinase. The mRNA expressions of various proteinases and their inhibitors in
relation to HGF activation in hair growth were examined using animals with a
synchronous hair cycle. Total RNA were extracted from the anterior dorsal skin of
rats in different hair cycle stages, and mRNA expressions of the specific genes
were compared using semiquantitative reverse transcription polymerase chain
reaction. The mRNA of HGF, HGF activator, urokinase, plasminogen activator
inhibitor (PAI)-1, nexin-1, matrix metalloproteinase (MMP)-2, and tissue
inhibitor of metalloproteinase (TIMP)-1 were expressed strongly in anagen tissue
and slightly in telogen tissue. Moreover, topical application of 1% minoxidil
sulfate to the anterior dorsal skin of rats in telogen stimulated hair growth and
increased the mRNA expressions of HGF and MMP-2. These findings suggest that some
proteinases and their inhibitors, strongly expressed in anagen, may act as hair
growth regulatory molecules, and may also be involved in processing the latent
form of HGF.
PMID- 10674389
TI - Peribulbar innervation and substance P expression following nonpermanent injury
to the human scalp hair follicle.
AB - The hair pluck procedure alters the anatomy of the anagen hair bulb. Hemorrhage
can occur in the mesenchymal sheath and breaks at the proximal epithelium, above
or around the upper third of the dermal papilla, have been reported. We
hypothesized that innervation, as identified with protein gene product 9.5 (PGP
9.5), and expression of the neuropeptide Substance P (SP) within the dermal
papilla would also be altered following plucking. We focused on studying SP as
this neuropeptide has been associated with several cellular responses, including
anagen hair growth in the C57BL/6 mouse model. Four millimeter punch biopsies
were obtained from the occipital scalp of two healthy adults. Hair was then
plucked and additional biopsies were obtained immediately, and at 1 d, 1 wk, and
1 mo after plucking. Each set was processed for immunohistochemical analyses and
in-focus optical sections of the dermal papilla were captured by laser scanning
confocal microscopy and later reconstructed into single images. Following injury,
SP was expressed in a disorganized pattern below the dermal papilla. There was
also a significant reduction in labeled neuronal cells, and SP expression was
enhanced within peribulbar blood vessels at 1 d and 1 wk. By 1 mo, peribulbar
nerves, vessels, and SP expression were similar to baseline observations. It
remains to be ascertained whether PGP 9.5, also known as unbiquitin hydrolase,
and SP are involved in the proliferation of new matrix cells in the human scalp
hair follicle following injury.
PMID- 10674390
TI - Identification of a novel SCD gene and expression of the SCD gene family in mouse
skin.
AB - We have refined the position of asebia locus by genotyping DNA from more than 600
backcross mice derived from asebia mouse and a genetically unrelated strain. One
of the candidate genes in the locus is stearoyl-CoA desaturase (SCD). Previously
two members of this gene family, namely SCD1 and SCD2, have been described. We
have found, for the first time, that these SCD genes are expressed in skin.
Moreover, we have identified a third species of SCD in the mouse skin. The most
prominent SCD species is SCD1 in the mouse skin. The implications of this gene
family to skin are discussed.
PMID- 10674391
TI - The fate of hair follicle melanocytes during the hair growth cycle.
AB - The fate of the follicular pigmentary unit during the hair growth cycle has long
been one of the great enigmas of both hair follicle and pigment cell biology.
Although melanocytes are distributed in several different compartments of the
anagen hair follicle, melanogenically active cells are located only in the hair
bulb, where they are directly involved in hair shaft pigmentation. These pigment
cells are readily detectable only when they become melanogenically active during
anagen III of the hair growth cycle. Thus, their status during hair follicle
regression (catagen), when melanogenesis is switched off, until they re-appear
again as pigment-producing cells in the anagen III hair follicle, has remained
poorly defined. Historically, it has been proposed that hair bulb melanocytes
adopt a self-perpetuating, catagen-resistant strategy of de-differentiation
during hair follicle regression and re-differentiation upon entry into a new
anagen phase; however, this explanation remains problematic in the absence of
evidence for de-differentiation/re-differentiation plasticity in most
nonmalignant cell systems.
PMID- 10674392
TI - Avian integument provides multiple possibilities to analyse different phases of
skin appendage morphogenesis.
AB - To analyse the morphogenic events during skin appendage formation, it is
important to have an animal model that offers distinct patterns at various stages
of development and is accessible to analysis using state of the art technology.
The avian integument is such a model. Combining experimental embryologic
approaches, organ cultures, and gene transduction technology, we are now able to
begin to address the molecular basis of pattern formation, primordium initiation,
anterior-posterior axis formation, proximo-distal axis formation, phenotypic
determination, and others. Parallel mechanisms are usually found in feathers and
hairs, and the avian integument model has matured to be a major source of new
findings in the study of skin appendage morphogenesis. More information on the
avian integument model can be found at website http://www.hsc.usc.educmchuong.
PMID- 10674393
TI - Chronobiology of the hair follicle: hunting the " hair cycle clock".
AB - The hair follicle (HF) is the only mammalian organ that undergoes life-long,
cyclic transformations from long stages of growth (anagen), via rapid, apoptosis
driven organ involution (catagen) to a stage of relative "resting" (telogen). The
controls that underlie these transformations clearly reside in and/or around the
HF itself, and are likely to reflect - essentially autonomous, yet highly
manipulable - changes in the local signalling milieu of e.g., hair growth
modulatory growth factors, cytokines, hormones and adhesion molecules. Yet the
molecular nature and organization of the "hair cycle clock" (HCC) that drives
these cyclic switches in the local signalling milieu remain obscure, and there is
not even a fully satisfactory theory of hair cycle control. Since deciphering of
the HCC is of paramount clinical importance, and since corresponding working
hypotheses are badly needed to guide the design of more incisive experiments that
identify the elusive central "oscillator" mechanism behind the HCC, we discuss
basic requirements any convincing HCC theory should meet. After arguing that at
least four distinct timing devices underlie HF chronobiology ("morphogenesis
clock", "cycling inducer", "desynchronizer", and the actual HCC), previously
proposed HCC theories are briefly and critically reviewed. In the light of
intriguing regulatory similarities between the HCC and the cell cycle machinery,
we suggest here that the HCC may be driven by autonomous, cell cycle-coupled
secretory activities of the HF mesenchyme, namely by changes in the G0/G1
associated secretion of "papilla morphogens" by dermal papilla fibroblasts.
Hopefully, this provocative hypothesis will encourage the proposition of novel,
comprehensive HCC theories.
PMID- 10674394
TI - Silencing subdomains of v-ErbA interact cooperatively with corepressors:
involvement of helices 5/6.
AB - Members of the thyroid hormone receptor (TR) family act on vertebrate development
and homeostasis by activating or repressing transcription of specific target
genes in a ligand-dependent way. Repression by TR in the absence of ligand is
mediated by an active silencing mechanism. The oncogene v-ErbA is a variant form
of TR unable to bind hormone and thus acts as a constitutive repressor.
Functional studies and mutation analysis revealed that the TR/v-ErbA silencing
domain is composed of three silencing subdomains (SSD1-3) which, although
nonfunctional individually, synergize such that silencing activity is restored
when they are combined in a heteromeric complex. Here we demonstrate, using
protein interaction assays in vitro and in vivo, that the inactive v-ErbA point
mutant L489R within helix 5/6 in SSD2 fails to interact with the two corepressors
N-CoR (nuclear receptor corepressor) or SMRT (silencing mediator of retinoic acid
and thyroid hormone receptor). Furthermore, mutants in SSD1 and SSD3 exhibit a
reduced corepressor recruitment corresponding to their weak residual silencing
activity. In mammalian two-hybrid assays, only the combination of all three
silencing subdomains, SSD1-3, leads to a cooperative binding to the corepressors
N-CoR or SMRT comparable to that of the full-length v-ErbA repression domain. In
conclusion, full silencing activity requires corepressor interaction with all
three silencing subdomains, SSD1-3. Among these, SSD2 is a new target for N-CoR
and SMRT and is essential for corepressor binding and function.
PMID- 10674395
TI - Transcription factors Oct-1 and C/EBPbeta (CCAAT/enhancer-binding protein-beta)
are involved in the glutamate/nitric oxide/cyclic-guanosine 5'-monophosphate
mediated repression of mediated repression of gonadotropin-releasing hormone gene
expression.
AB - The physiological actions of nitric oxide (NO) as a signaling molecule in
endothelial and brain cells and as a toxic molecule used by activated immune
cells have been the focus of a wide range of studies. Nevertheless, the
downstream effector molecules of this important neuromodulator are not well
understood. We have previously demonstrated that expression of the gene for the
reproductive neuropeptide, GnRH, is repressed by the glutamate/NO/cyclic GMP
(cGMP) signal transduction pathway through cGMP-dependent protein kinase in the
hypothalamic GnRH-secreting neuronal cell line GT1-7. This repression localized
within a previously characterized 300-bp neuron-specific enhancer. Here, we find
that mutation of either of two adjacent elements within the enhancer eliminates
repression by this pathway. An AT-rich sequence located at -1695 has homology to
the octamer motif known to bind POU-homeodomain proteins, while the adjacent
element at -1676 has homology to the C/EBP (CCAAT/enhancer-binding protein)
protein family consensus sequence. Antibody supershift assays reveal that one of
the proteins bound at the -1695 sequence is Oct-1, and one of the proteins bound
to the element at -1676 is C/EBPbeta. These two proteins can bind simultaneously
to the adjacent -1695 and -1676 binding sites in vitro. In nuclear extracts of
GT1-7 cells treated with an NO donor, the intensity of the Oct-1 complex is
increased. However, although Western blot analysis indicates that neither Oct-1
nor C/EBPbeta protein levels are increased, the relative binding affinity of Oct
1 is increased. Dephosphorylation of the nuclear extracts decreases binding of
the Oct-1 complex to the -1695 site only in NO donor-treated extracts. Thus, we
conclude that Oct-1 and C/EBPbeta are both downstream transcriptional regulators
involved in the repression of GnRH gene expression by the glutamate/NO/ cGMP
signal transduction pathway.
PMID- 10674396
TI - Multiple signaling pathways mediate interleukin-4-induced 3beta-hydroxysteroid
dehydrogenase/delta5-delta4 isomerase type 1 gene expression in human breast
cancer cells.
AB - The 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (3beta-HSD)
isoenzymes catalyze an essential step in the formation of all classes of active
steroid hormones. We have recently shown that 3beta-HSD type 1 gene expression is
specifically induced by interleukin (IL)-4 and IL-13 in breast human cancer cell
lines and in normal human mammary epithelial cells in primary culture. There is
evidence that IL-4 stimulates bifurcating signaling pathways in which the signal
transducer and activator of transcription-6 (Stat6)-signal pathway is involved in
differentiation and gene regulation, whereas insulin receptor substrate (IRS)
proteins mediate the mitogenic action of IL-4. In fact, we have shown that Stat6
was activated by IL-4 in all cell lines studied where IL-4 induced 3beta-HSD
expression, but not in those that failed to respond to IL-4. The present study
was designed to investigate the potential contribution of IRS proteins and their
downstream targets to IL-4-induced 3beta-HSD type 1 gene expression. IL-4 rapidly
induced IRS-1 and IRS-2 phosphorylation in ZR-75-1 human breast cancer cell
lines. Moreover, insulin-like growth factor (IGF)-I and insulin, which are well
known to cause IRS-1 and IRS-2 phosphorylation, increased the stimulatory effect
of IL-4 on 3beta-HSD activity. IRS-1 and IRS-2 are adapter molecules that provide
docking sites for different SH2-domain-containing proteins such as the
phosphatidylinositol (PI) 3-kinase. In this light, the inhibition of IL-4-induced
3beta-HSD expression by wortmannin and LY294002, two potent PI 3-kinase
inhibitors, indicates the probable involvement of the PI 3-kinase signaling
molecules in this response to IL-4. Furthermore, it has been suggested that the
IRS proteins are part of the signaling complexes that lead to activation of the
mitogen-activated protein (MAP) kinase by insulin; thus we investigated the
potential role of the MAP kinase (MAPK) cascade in the IL-4 action. In ZR-75-1
cells, both the activation of MAPK by IL-4 and the IL-4-induced 3beta-HSD
activity were completely blocked by PD98059, an inhibitor of MAPK activation.
Wortmannin also blocked MAPK activation by IL-4, IGF-I, and insulin, suggesting
that the MAPK cascade acts as a downstream effector of PI 3-kinases. To further
understand the cross-talk between signaling pathways involved in IL-4 action, we
investigated the possible involvement of protein kinase C (PKC). The potential
role of PKC was suggested by the observation that the well known PKC activator
phorbol-12-myristate-13-acetate (PMA) potentiated the IL-4-induced 3beta-HSD
activity. Taken together, these findings suggest the existence of a novel
mechanism of gene regulation by IL-4. This mechanism would involved the
phosphorylation of IRS-1 and IRS-2, which transduce the IL-4 signal through a PI
3-kinase- and MAPK-dependent signaling pathway. The inability of IGF-I, insulin,
and PMA to stimulate 3beta-HSD expression by themselves in the absence of IL-4
makes obvious the absolute requirement of an IL-4-specific signaling molecule.
Our findings thus suggest that the multiple pathways downstream of IRS-1 and IRS
2 must act in cooperation with the IL-4-specific transcription factor Stat6 to
mediate the induction of 31beta-HSD type 1 gene expression in ZR-75-1 human
breast cancer cells.
PMID- 10674397
TI - Apoptosis mediated by activation of the G protein-coupled receptor for
parathyroid hormone (PTH)/PTH-related protein (PTHrP).
AB - The present studies were carried out to evaluate the mechanisms by which
PTH/PTHrP receptor (PTHR) activation influences cell viability. In 293 cells
expressing recombinant PTHRs, PTH treatment markedly reduced the number of viable
cells. This effect was associated with a marked apoptotic response including DNA
fragmentation and the appearance of apoptotic nuclei. Similar effects were
evidenced in response to serum withdrawal or to the addition of tumor necrosis
factor (TNFalpha). Addition of caspase inhibitors or overexpression of bcl-2
partially abrogated apoptosis induced by serum withdrawal. Caspase inhibitors
also protected cells from PTH-induced apoptosis, but overexpression of bcl-2 did
not. The effects of PTH on cell number and apoptosis were neither mimicked by
activators of the cAMP pathway (forskolin, isoproterenol) nor blocked by an
inhibitor (H-89). However, elevation of Ca(i)2+ by addition of thapsigargin
induced rapid apoptosis, and suppression of Ca(i)2+ by overexpression of the
calcium- binding protein, calbindin D28k, inhibited PTH-induced apoptosis. The
protein kinase C inhibitor GF 109203X partially inhibited PTH-induced apoptosis.
Regulator of G protein signaling 4 (RGS4) (an inhibitor of the activity of the
alpha-subunit of Gq) suppressed apoptotic signaling by the PTHR, whereas the C
terminal fragment of GRK2 (an inhibitor of the activity of the beta(gamma)
subunits of G proteins) was without effect. Chemical mutagenesis allowed
selection of a series of 293 cell lines resistant to the apoptotic actions of
PTH; a subset of these were also resistant to TNFalpha. These results suggest
that 1) apoptosis produced by PTHR and TNF receptor signaling involve converging
pathways; and 2) Gq-mediated phospholipase C/Ca2+ signaling, rather than Gs
mediated cAMP signaling, is required for the apoptotic effects of PTHR
activation.
PMID- 10674398
TI - Dual regulation of somatostatin receptor subtype 1 gene expression by pit-1 in
anterior pituitary GH3 cells.
AB - Somatostatin represents a major release inhibiting factor for hypophyseal
hormones and mediates its action via five receptor subtypes, sst1-sst5, that are
all present in the anterior pituitary. The pituitary specific transcription
factor Pit-1 is essential for the pituitary development and pituitary-specific
gene expression. Here the transcriptional regulation of the sst1 gene, which
contains putative Pit-1-binding sites, was studied in anterior pituitary GH3
cells. We found that a fragment of 2 kb suffices to drive the expression of a
reporter gene specifically in this cell line. Positive and negative cis
regulatory elements contributed to the promoter activity. Among these elements
two functional binding sites for Pit-1 were identified. While the proximal site
mediated transcriptional activation, the distal site attenuated transcription of
reporter gene constructs. Mutations of the proximal Pit-1 site prevented
expression of the reporter gene. Targeting Pit-1 mRNA by antisense
oligonucleotides caused inhibition of transcription of reporter gene constructs
containing the proximal Pit-1-binding site. Moreover, the expression of the
endogenous sst1 gene in GH3 anterior pituitary cells was blocked. This resulted
in reduced sst1 levels at the plasma membrane. Reduced sst1 levels were
associated with a diminished antisecretory response to the sst1-specific agonist
CH-275 and somatostatin. These results demonstrate the importance of Pit-1 for
the expression of the sst1 gene, which hence is placed under common genetic
control with the genes for hypophysiotropic hormones and the gene for the
receptor of GH-releasing hormone.
PMID- 10674399
TI - The nematode leucine-rich repeat-containing, G protein-coupled receptor (LGR)
protein homologous to vertebrate gonadotropin and thyrotropin receptors is
constitutively active in mammalian cells.
AB - The receptors for LH, FSH, and TSH belong to the large G protein-coupled, seven
transmembrane protein family and are unique in having a large N-terminal
extracellular (ecto-) domain containing leucine-rich repeats important for
interactions with the large glycoprotein hormone ligands. Recent studies
indicated the evolution of an expanding family of homologous leucine-rich repeat
containing, G protein-coupled receptors (LGRs), including the three known
glycoprotein hormone receptors; mammalian LGR4 and LGR5; and LGRs in sea anemone,
fly, and snail. We isolated nematode LGR cDNA and characterized its gene from the
Caenorhabditis elegans genome. This receptor cDNA encodes 929 amino acids
consisting of a signal peptide for membrane insertion, an ectodomain with nine
leucine-rich repeats, a seven-TM region, and a long C-terminal tail. The nematode
LGR has five potential N-linked glycosylation sites in its ectodomain and
multiple consensus phosphorylation sites for protein kinase A and C in the
cytoplasmic loop and C tail. The nematode receptor gene has 13 exons; its TM
region and C tail, unlike mammalian glycoprotein hormone receptors, are encoded
by multiple exons. Sequence alignments showed that the TM region of the nematode
receptor has 30% identity and 50% similarity to the same region in mammalian
glycoprotein hormone receptors. Although human 293T cells expressing the nematode
LGR protein do not respond to human glycoprotein hormones, these cells exhibited
major increases in basal cAMP production in the absence of ligand stimulation,
reaching levels comparable to those in cells expressing a constitutively
activated mutant human LH receptor found in patients with familial male-limited
precocious puberty. Analysis of cAMP production mediated by chimeric receptors
further indicated that the ectodomain and TM region of the nematode LGR and human
LH receptor are interchangeable and the TM region of the nematode LGR is
responsible for constitutive receptor activation. Thus, the identification and
characterization of the nematode receptor provides the basis for understanding
the evolutionary relationship of diverse LGRs and for future analysis of
mechanisms underlying the activation of glycoprotein hormone receptors and
related LGRs.
PMID- 10674400
TI - Involvement of STAT5 (signal transducer and activator of transcription 5) and HNF
4 (hepatocyte nuclear factor 4) in the transcriptional control of the hnf6 gene
by growth hormone.
AB - HNF-6 is a tissue-restricted transcription factor that participates in the
regulation of several genes in liver. We reported earlier that in adult rats, HNF
6 mRNA concentration in liver drops to almost undetectable levels after
hypophysectomy and returns to normal after 1 week of GH treatment. We now show
that this results from a rapid effect of GH, and we characterize its molecular
mechanism. In hypophysectomized rats, HNF-6 mRNAs increased within 1 h after a
single injection of GH. The same GH-dependent induction was reproduced on
isolated hepatocytes. To determine whether GH regulates hnf6 expression at the
gene level, we studied its promoter. DNA binding experiments showed that 1) the
transcription factors STAT5 (signal transducer and activator of transcription 5)
and HNF-4 (hepatocyte nuclear factor 4) bind to sites located around -110 and
650, respectively; and 2) STAT5 binding is induced and HNF-4 binding affinity is
increased in liver within 1 h after GH injection to hypophysectomized rats. Using
transfection experiments and site-directed mutagenesis, we found that STAT5 and
HNF-4 stimulated transcription of an hnf6 gene promoter-reporter construct.
Furthermore, GH stimulated transcription of this construct in cells that express
GH receptors. Consistent with our earlier finding that HNF-6 stimulates the hnf4
and hnf3beta gene promoters, GH treatment of hypophysectomized rats increased the
liver concentration of HNF-4 and HNF-3beta mRNAs. Together, these data
demonstrate that GH stimulates transcription of the hnf6 gene by a mechanism
involving STAT5 and HNF-4. They show that HNF-6 participates not only as an
effector, but also as a target, to the regulatory network of liver transcription
factors, and that several members of this network are GH regulated.
PMID- 10674401
TI - Association of 2',5'-oligoadenylate synthetase with the prolactin (PRL) receptor:
alteration in PRL-inducible stat1 (signal transducer and activator of
transcription 1) signaling to the IRF-1 (interferon-regulatory factor 1)
promoter.
AB - The PRL receptor (PRL-R) signals through the Janus tyrosine kinases (JAK) and
other non-JAK tyrosine kinases, some of which are preassociated with the PRL-R.
To clone PRL-R interacting proteins, the intracellular domain (ICD) of the long
form of the PRL-R was used in a yeast two-hybrid screen of a human B cell cDNA
library. One PRL-R interacting protein was identified as the 42-kDa form of the
enzyme 2',5'-oligoadenylate synthetase (OAS). The in vivo interactions in yeast
were further confirmed by an in vitro interaction assay and by
coimmunoprecipitation in transfected mammalian cells. Functionally, OAS reduced
the basal activity of two types of promoters in transiently transfected COS-1
cells. In the presence of PRL, OAS inhibited PRL induction of the immediate early
IRF-1 (interferon-regulatory factor 1) promoter, but not PRL induction of the
differentiation-specific beta-casein promoter, suggesting that OAS exerts
specific effects on immediate early gene promoters. The inhibitory effects of OAS
were accompanied by a reduction in PRL-inducible Stat1 (signal transducer and
activator of transcription 1) DNA binding activity at the IRF-1 GAS (interferon
gamma-activated sequence) element. These results demonstrate a novel interaction
of OAS with the PRL-R and suggest a role for OAS in modulating Stat1-mediated
signaling to an immediate early gene promoter. Although previously characterized
as a regulator of ribonuclease (RNase) L antiviral responses, OAS may have
additional effects on cytokine receptor signal transduction pathways.
PMID- 10674402
TI - Prolactin enhances CCAAT enhancer-binding protein-beta (C/EBP beta) and
peroxisome proliferator-activated receptor gamma (PPAR gamma) messenger RNA
expression and stimulates adipogenic conversion of NIH-3T3 cells.
AB - Extracellular stimuli trigger adipocyte differentiation by inducing the complex
cascades of transcription. Transcription factors CCAAT enhancer-binding proteins
(C/EBPs) and peroxisome proliferator-activated receptor gamma (PPARgamma) play
crucial roles in this process. Although ectopic expression of these factors in
NIH-3T3 cells, a multipotential mesenchymal stem cell line, results in adipogenic
conversion, little is known as to hormonal factors that regulate adipogenesis in
these cells. In this report we demonstrate that PRL, a lactogenic hormone,
enhances C/EBPbeta and PPARbeta mRNA expression and augments adipogenic
conversion of NIH-3T3 cells. Moreover, we show that ectopic expression of the PRL
receptor in NIH-3T3 cells results in efficient adipocyte conversion when
stimulated with PRL and a PPARgamma ligand, as evidenced by expression of the
adipocyte differentiation-specific genes as well as the presence of fat-laden
cells. We further demonstrate that signal transducer and activator of
transcription 5 (Stat5), a PRL signal transducer, activates aP2 promoter in a PRL
dependent manner. These results suggest that PRL acts as an adipogenesis
enhancing hormone in NIH-3T3 cells.
PMID- 10674403
TI - Calmodulin antagonists inhibit insulin-stimulated GLUT4 (glucose transporter 4)
translocation by preventing the formation of phosphatidylinositol 3,4,5
trisphosphate in 3T3L1 adipocytes.
AB - It has been previously reported that calmodulin plays a regulatory role in the
insulin stimulation of glucose transport. To examine the basis for this
observation, we examined the effect of a panel of calmodulin antagonists that
demonstrated a specific inhibition of insulin-stimulated glucose transporter 4
(GLUT4) but not insulin- or platelet-derived growth factor (PDGF)-stimulated
GLUT1 translocation in 3T3L1 adipocytes. These treatments had no effect on
insulin receptor autophosphorylation or tyrosine phosphorylation of insulin
receptor substrate 1 (IRS1). Furthermore, IRS1 or phosphotyrosine antibody
immunoprecipitation of phosphatidylinositol (PI) 3-kinase activity was not
affected. Despite the marked insulin and PDGF stimulation of PI 3-kinase
activity, there was a near complete inhibition of protein kinase B activation.
Using a fusion protein of the Grp1 pleckstrin homology (PH) domain with the
enhanced green fluorescent protein, we found that the calmodulin antagonists
prevented the insulin stimulation of phosphatidylinositol 3,4,5-trisphosphate
[PI(3,4,5)P3] formation in vivo. Similarly, although PDGF stimulation increased
PI 3-kinase activity in in vitro immunoprecipitation assays, there was also no
significant formation of PI(3,4,5)P3 in vivo. These data demonstrate that
calmodulin antagonists prevent insulin-stimulated GLUT4 translocation by
inhibiting the in vivo production of PI(3,4,5)P3 without directly affecting IRS1-
or phosphotyrosine-associated PI 3-kinase activity. This phenomenon is similar to
that observed for the PDGF stimulation of 3T3L1 adipocytes.
PMID- 10674405
TI - Inhibitory effect of hexapeptide (RGRHGD) on platelet aggregation.
AB - The B chain of beta-bungarotoxin 1-6 sequence, RGRHGD, presents the highest local
average hydrophilicity measured by Kyte and Doolittle modeling analysis. The
RGRHGD holds parts of both RGD and KGD peptides, which have been reported as
having high binding affinity to GPIIb-IIIa. The present study evaluates whether
the synthesized hexapeptide, RGRHGD, has an antiplatelet effect and further
elucidates the possible mechanisms of action. RGRHGD dose-dependently inhibited
rabbit platelet aggregation and adenosine triphosphate release induced by
arachidonic acid, collagen, platelet-activating factor, thrombin, or U46619 with
the IC50 range of 82.7 to 510 microg/mL. The platelet thromboxane B2 formation
induced by collagen or thrombin was also significantly decreased by RGRHGD, but
there was no effect on arachidonic acid-induced thromboxane B2 formation. In
addition, RGRHGD also inhibited the rise of intracellular calcium level
stimulated by arachidonic acid, collagen, or thrombin in Fura 2-AM-loaded
platelets. The adenosine 3',5'-cyclic monophosphate level of washed platelets was
not affected by RGRHGD. In conclusion, these data indicate that the inhibitory
effect of RGRHGD on platelet aggregation may be due to the attenuation of
thromboxane A2 formation and intracellular calcium mobilization. In addition,
this study may provide a useful method of finding potential therapeutic agents by
using molecular modeling analysis.
PMID- 10674404
TI - Suppression of transcription factor Egr-1 by curcumin.
AB - The transcription factor early growth response-1 gene product (Egr-1) is a member
of the family of immediate early response genes and regulates a number of
pathophysiologically relevant genes in vasculature that are involved in growth,
differentiation, immune response, wound healing, and blood clotting. In the
present study, we investigated the effect of curcumin, a natural plant phenolic
compound known to exhibit anticarcinogenic, antioxidant, and antiinflammatory
properties, on Egr-1 expression in endothelial cells and fibroblasts. Gel
mobility shift assays showed that pretreatment of endothelial cells and
fibroblasts with curcumin suppressed phorbol 12-myristate 13-acetate and serum
induced Egr-1 binding activity to the consensus Egr-1 binding site and also to
the Egr-1 binding site present in the promoter of tissue factor gene. Western
blot analysis revealed that curcumin inhibited phorbol 12-myristate 13-acetate
induced de novo synthesis of Egr-1 protein in endothelial cells. Suppression of
Egr-1 protein expression in curcumin-treated cells stemmed from the suppression
of Egr-1 mRNA. Northern blot analysis showed that curcumin inhibited serum and
phorbol 12-myristate 13-acetate induced expression of tissue factor and urokinase
type plasminogen activator receptor mRNA in fibroblasts. Cumulatively, the data
show that curcumin suppresses the induction of transcription factor Egr-1 and
thereby modulates the expression of Egr-1-regulated genes in endothelial cells
and fibroblasts.
PMID- 10674406
TI - Differential in vitro effects of the platelet glycoprotein IIb/IIIa inhibitors
abixicimab or SR121566A on platelet aggregation, fibrinogen binding and platelet
secretory parameters.
AB - The aim of this study was to compare fibrinogen binding, inhibition of platelet
aggregation and secretory potential of the MAb abciximab (0.5-5 microg/mL) and
the peptidomimetic compound SR121566A (15-250 ng/mL) in vitro in whole blood.
Fibrinogen binding was followed by flow cytometry; platelet function was
evaluated by light transmittance and by impedance aggregometry. Secretory
functions of platelets were evaluated using ATP as marker for early secretion by
dense granulae and P-selectin (CD62) for alpha-granular secretion as well as CD63
for lysosomal degranulation. Results showed that fibrinogen binding induced by 5
microM TRAP was maximally inhibited greater than 80% at 3 microg/mL abciximab or
at 250 ng/mL SR121566A. At these concentrations of antagonists, platelet
aggregation induced by 5 microM ADP or 2 microg/mL collagen was inhibited
completely. Expression of CD62 was reduced 34% with abciximab or 15% with
SR121566A; CD63 expression was reduced 22% with both agents. With both agents,
the EC50 for inhibition of CD62 and CD63 expressions was in similar magnitudes
than the EC50 for fibrinogen binding inhibition. With 3 microg/mL abciximab, ATP
secretion was maximally reduced to 50% of the control, whereas SR121566A at 250
ng/mL had no inhibitory effect on this parameter. A slight increase in ATP
secretion was seen with 0.5 microg/mL abciximab and with SR121566A in
concentrations of less than 45 ng/mL. The data suggest a discoupling between the
anti-aggregatory and the antisecretory effects of IIb/IIIa antagonists. Because
it is not established to what extend CD62 or CD63 expression can be reduced by
any means, the reduction by 20-30% obtained by 3 microg/mL abciximab or 250 ng/mL
SR121566A might already be the maximum possible inhibition by these agents.
PMID- 10674407
TI - Relationship between endothelial cell markers and arterial stenosis in peripheral
and carotid artery disease.
AB - Damage to the endothelium is an important component of atherosclerosis and can be
quantified by measuring plasma markers, such as von Willebrand factor,
thrombomodulin, intercellular adhesion molecule-1, and E-selectin. We
hypothesized that increased levels of these markers would be related to
objectively defined disease severity among patients with peripheral
atherosclerosis or carotid atherosclerosis. To test this, we measured the markers
by using ELISA in the plasma of 45 patients with intermittent claudication alone
and in 53 patients presenting with transient ischemic attack. Disease severity in
the former was by ankle-brachial pressure index and in the latter by ultrasound
defined % stenosis. Any symptomatic dual disease or history or present coronary
atherosclerosis warranted exclusion. Data were correlated according to Spearman's
method. The only significant correlation was between von Willebrand factor and
ankle-brachial pressure index (r = -0.39, p = 0.008). Our data suggest that von
Willebrand factor is the most sensitive marker of peripheral atherosclerosis and
that none of the plasma markers seems to be a useful marker of the degree of
carotid artery stenosis.
PMID- 10674408
TI - Antiplatelet effects of sodium nitroprusside in flowing human blood: studies
under normoxic and hypoxic conditions.
AB - We explored the ability of sodium nitroprusside to modify adhesive and cohesive
function of platelets in flowing blood, under normoxic and hypoxic conditions.
Aliquots of both untreated and sodium nitroprusside-treated blood were prepared
for studies of: (1) platelet aggregation in plasma; (2) erythrocyte
deformability; (3) platelet interaction with damaged subendothelium, by using a
well-defined perfusion system; and (4) blood gasometry in the perfused samples.
Results showed that sodium nitroprusside-treated blood always showed a totally
inhibited arachidonic acid-induced platelet aggregation in plasma, as well as
significantly increased erythrocyte deformability (0.44+/-0.09 up to 0.66+/-0.05;
p<0.05). However, treatment with sodium nitroprusside did not modify the pattern
of platelet interaction with subendothelium (percentage of contact, adhesion,
thrombus, and covered surface) with respect to untreated blood, under any of the
shear rates used (300, 800, and 1800 seconds(-1)), although it significantly
reduced the height of thrombi (9.8+/-0.4 vs. 8.3+/-0.4 microm; p<0.05). Hypoxic
conditions did not have a noticeable effect in modifying antiplatelet effects of
sodium nitroprusside. Additionally, the presence of sodium nitroprusside impaired
the normal oxygenation of the blood during perfusion. pO2 in control untreated
samples rose from 40.3+/-5.0 mm Hg perfusions to 100.4+/-12.5 mm Hg but remained
at 66.3+/-6.3 mm Hg in sodium nitroprusside-treated blood (p<0.05). Our results
did not show a significant effect of sodium nitroprusside in the modulation of
platelet interaction with subendothelium. The marginal reduction in the thrombi
height could be related to rheological interference of increased erythrocyte
deformability.
PMID- 10674409
TI - Effect of plasminogen activator inhibitor-1 4G/5G polymorphism in Turkish deep
vein thrombotic patients with and without FV1691 G-A.
AB - A decreased fibrinolytic activity due to increased levels of plasminogen
activator inhibitor-1 has been shown in deep vein thrombosis patients. Elevated
plasma plasminogen activator inhibitor-1 levels are associated with the 4G allele
of a 4G/5G polymorphism located in the promoter region of the plasminogen
activator inhibitor-1 gene. Because there is no existing data in the Turkish
population, we aimed to study these mutations in patients with deep vein
thrombosis (n = 136) and normal controls (n = 113), consecutively selected among
unrelated healthy subjects without personal and familial history of
atherothrombosis from Ankara, Turkey. DNA was extracted by conventional methods,
and polymerase chain reaction of the plasminogen activator inhibitor-1 4G/5G
polymorphism was performed according to a previously described method. Genotype
distributions of FV 1691G-A and plasminogen activator inhibitor-1 4G/5G are as
follows: plasminogen activator inhibitor-1 4G (patients) 0.562, plasminogen
activator inhibitor-1 4G (controls) 0.50 (p = 0.6); FV1691A (patients) 0.147,
FV1691A (controls) 0.035 (p = 0.005). Our data indicated that plasminogen
activator inhibitor-1 4G/5G does not have an effect on the thrombotic risk.
Carrying the 4G allele either in heterozygous or homozygous state increases the
risk in the presence of FV1691A (odds ratio: 9.8 and 6.9, confidence interval 95%
2.9-32.7 and 1.3-35.8). FV1691A is an independent risk factor for thrombosis
(odds ratio: 5.5, confidence interval: 95% 2.5-12.1). We concluded that
coexistence of FV1691A and plasminogen activator inhibitor-1 4G allele leads to
an increased risk for thrombosis leading a further evidence to another
prothrombotic factor that may be necessary for the development of a manifest
thrombotic event.
PMID- 10674410
TI - A simple screening assay for certain fibrinolysis parameters (FIPA).
AB - Hemostasis, the system of generation and degradation of thrombi, consists of
coagulation and fibrinolysis. Whereas global assays to study coagulation have
existed for many years, there has been no simple, rapid, and economic routine
test for the plasmatic fibrinolysis parameters plasminogen activator inhibitor-1,
alpha2-antiplasmin, plasminogen, and aprotinin. Here a fast functional global
assay for these plasmatic fibrinolytic parameters is presented. However, the
present assay is not sensitive to physiological concentrations of prourokinase or
tissue-type plasminogen activator. The following assay conditions have been found
to be optimal: 50 microL of citrated plasma is incubated with 50 microL of 10 IU
urinary-type plasminogen activator (urokinase)/mL, 1.1 mmol/L tranexamic acid, 1%
polygelin, 0.1% Triton X-100, phosphate-buffered saline, pH 7.4, for 20 min at 37
degrees C (plasmin generation phase). Then 50 microL of 3 mmol/L HD-Nva-CHA-Lys
pNA, 1.05 mol/L KCl is added, and deltaA (405 nm)/10 min (37 degrees C) is
determined, by using a microtiterplate reader (plasmin detection phase). The
results are calibrated against pooled normal plasma (100% plasmatic fibrinolytic
parameters activity). The intra- and interassay coefficients of variation have
been found to be less than 5%. The detection limit (sensitivity) of the
functional fibrinolysis assay is 5 % of the normal plasmatic fibrinolysis
parameters activity. The normal plasmatic fibrinolysis parameters activity is
100%, sigma = 25%. The plasmatic fibrinolysis parameters activity correlates
negatively (r = -0.684) with the plasminogen activator inhibitor-1 activity of
patient samples. The plasmatic fibrinolysis parameters assay is a simple, rapid,
and economic functional test for several clinical relevant fibrinolysis
parameters.
PMID- 10674411
TI - Antiplatelet drugs attenuate progression of carotid intima-media thickness in
subjects with type 2 diabetes.
AB - The intima-media thickness of the carotid artery has been established as a
surrogate of definite atherosclerosis in subjects with high risk of vascular
events. This study was done to evaluate the effectiveness of long-term
antiplatelet therapy in attenuating progression of the intima-media thickness of
the carotid artery of subjects with type 2 diabetes. Subjects who had an intima
media thickness over the threshold of the normal subjects but showed no symptoms
of vascular events were randomly divided into groups given antiplatelet drugs
[ticlopidine (n = 34) or a small dose of aspirin (n = 40)] or no drugs (n = 74).
For the follow-up period (3.0+/-0.06 years), the subjects not given antiplatelet
drugs showed a significantly higher progression of intima-media thickness
(0.067+/-0.009 mm/year) than those given ticlopidine (0.034+/-0.013 mm/year) or
aspirin (0.033+/-0.010 mm/year). Stepwise multivariant regression analysis showed
that long-term administration of ticlopidine or aspirin significantly reduced the
progression of intima-media thickness of diabetic subjects by 0.041 mm/year or
0.032 mm/ year, respectively. These data indicated that despite differences of
their pharmacological mechanisms, antiplatelet drugs could attenuate the
progression of intima-media thickness of the carotid artery wall of asymptomatic
type 2 diabetics who had early-stage carotid atherosclerosis.
PMID- 10674412
TI - Ethanol downregulates transcription of the PAI-1 gene in cultured human
endothelial cells.
AB - Human endothelial cells are a major site of synthesis for plasminogen activator
inhibitor type-1. Elevated plasminogen activator inhibitor type-1 levels in young
survivors of myocardial infarction [1] suggest that plasminogen activator
inhibitor type-1 may have an important pathologic role in the development of
coronary artery disease. Epidemiological studies indicate that moderate alcohol
consumption (1-2 drinks/day) reduces the risk for cardiovascular mortality. This
cardioprotective benefit has been attributed in part to an increase in
fibrinolysis, which decreases fibrin-based thrombosis. The studies described
herein were performed to determine whether moderate levels of ethanol affect
plasminogen activator inhibitor type-1 gene expression. Cultured human
endothelial cells were exposed to 0.1% v/v ethanol for 1 hour. Following
incubation in the absence of ethanol plasminogen activator inhibitor type-1, mRNA
levels were decreased in a time- and dose-dependent manner, reaching a maximum
decrease of 3- to 4-fold at 2 to 4 hours following ethanol challenge. This
decline in mRNA occurs at the transcription level; therefore, nuclear
transcription run-on assays were performed. A 2.5- to 5-fold decrease in the rate
of plasminogen activator inhibitor type-1 gene transcription was measured at 2
and 4 hours following ethanol challenge. Next, a 3.4- and a 1.1-kb fragment from
the plasminogen activator inhibitor type-1 promoter region were linked to a
luciferase reporter gene, and these constructs were transfected into human
endothelial cells. Treatment of these transiently transfected human endothelial
cells with ethanol showed a 2- to 3.5-fold decrease in promoter activity,
respectively. These results indicate that low doses of ethanol downregulate
transcription of the plasminogen activator inhibitor type-1 gene in cultured
human endothelial cells. However, the mechanism(s) for this transcriptional
decrease is currently unknown.
PMID- 10674413
TI - Effects of argatroban on thrombin-induced events in cultured vascular smooth
muscle cells.
PMID- 10674414
TI - Dermatan sulphate, heparin cofactor II, and F1+2 peptide in non-insulin-dependent
diabetes mellitus.
PMID- 10674415
TI - Information and communication systems for the assistance of carers based on
ACTION.
AB - Recent advances in telecommunication technologies allow the design of information
and communication systems for people who are caring for others in the home as
family members or as professionals in the health or community centres. The
present paper analyses and classifies the information flow and maps it to an
information life cycle, which governs the design of the deployed hardware,
software and the data-structure. This is based on the initial findings of ACTION
(assisting carers using telematics interventions to meet older persons' needs) a
European Union funded project. The proposed information architecture discusses
different designs such as centralized or decentralized Web and Client server
solutions. A user interface is developed reflecting the special requirements of
the targeted user group, which influences the functionality and design of the
software, data architecture and the integrated communication system using video
conferencing. ACTION has engineered a system using plain Web technology based on
HTML, extended with JavaScript and ActiveX and a software switch enabling the
integration of different types of videoconferencing and other applications
providing manufacturer independence.
PMID- 10674416
TI - Neural network detection of files of suicidal patients and suicidal profiles.
AB - The optimal configuration of backpropagation (BP) neural networks was determined
after 35 trials with different BP configurations evaluating the total detection
rate. Ten different training and testing sets were used to identify optimal
samples. All trials included sample files of patients with medically serious
suicidal attempts (MSSA) and those of non-suicidal patients. Fifty files were
used in each group for training and 49 files for testing with no overlap between
the samples. The target variable for training was seriousness of suicide attempt
(0 = non-suicidal, 1 = MSSA). The input set included 44 demographic, clinical and
patient-history variables. The optimal results showed that 93.8% of MSSA and
89.8% of the non-suicidal patient files were detected. Total success rate (TSR)
was 91.8% and positive and negative prediction values (PPV, NPV) were 92% and
95.6%, respectively. Living alone (6.76), treatment compliance (5.86), drug abuse
or dependence (2.8), global assessment of functioning (GAF) score (1.49), non
paranoid delusions (1.22) and suicide of first degree relative (1.1) were highly
associated with MSSA according to the Garson calculation. However, logistic
regression attributed high importance to hallucinations (p < 0.0001), diagnosis
(p < 0.002), number of children (p < 0.006), GAF score (p < 0.006), employment
status (p < 0.02) and stressors (p < 0.03). It was shown that: backpropagation
neural networks are very successful in identifying records of MSSA patients; a
high GAF score is associated with high risk of MSSA and is the only common
variable identified by both methods; and backpropagation identified two non
specific factors (living alone and treatment compliance) whereas statistics found
specific factors (hallucinations and diagnosis) highly associated with MSSA.
PMID- 10674417
TI - The DELPHI method as a consensus and knowledge acquisition tool for the
evaluation of the DIABETES system for insulin administration.
AB - DIABETES is a decision-support system in the field of insulin administration.
System performance evaluation is particularly difficult because of the absence of
a uniform decision-making model followed by the specialists. The DELPHI method
has been selected since it is appropriate for those domains where there is
divergence among experts' opinions. The DELPHI approach helps a number of
diabetologists arrive at a consensus and thus it facilitates performance
evaluation and further knowledge acquisition. Insulin administration regimes, for
100 diabetic subjects, were proposed by DIABETES and five diabetologists (round
1). These suggestions were compiled and forwarded back to the specialists who
proposed a second management approach (round 2). In each case, the experts were
asked to justify their decision and comment on the suggestions of their
colleagues and DIABETES. A novel scoring system for quantification of agreement
was adopted. The DELPHI procedure significantly increased the agreement among the
diabetologists from 67% to 84% (X2, p = 0.0001). The agreement between experts'
and DIABETES recommendations was to a level of 54%. A total of 3500 comments were
acquired by the experts.
PMID- 10674418
TI - Intranet-based multi-purpose medical records in orthopaedics.
AB - Quality assurance in orthopaedics--as in any medical speciality--relies on
precise medical records. Data quality is crucial for statistical evaluation;
missing values cannot be avoided but must be minimized. The quality assurance
system must be accessible from many locations within the clinic; given the
complex and heterogeneous computing infrastructure this is a technological
challenge. Intranet technology--the application of internet-tools in local
networks--can help to solve the technical problems. A generic Intranet-based
quality assurance system in orthopaedics was designed, implemented and evaluated.
The basic concept is an intranet data entry form which is generated semi
automatically from the data definition. This form is adapted according to the
individual needs of the doctors (intelligent data entry). By flexible data
transformation the same data set is used for clinical reports as well as
scientific evaluations. The first use was for ultrasound examinations of neonatal
hips. A report form consisting of 56 items was designed. Within the first 9-month
period 1303 cases have been documented.
PMID- 10674419
TI - Decision tree induction in the diagnosis of otoneurological diseases.
AB - Expert systems have been applied in medicine as diagnostic aids and education
tools. The construction of a knowledge base for an expert system may be a
difficult task; to automate this task several machine learning methods have been
developed. These methods can be also used in the refinement of knowledge bases
for removing inconsistencies and redundancies, and for simplifying decision
rules. In this study, decision tree induction was employed to acquire diagnostic
knowledge for otoneurological diseases and to extract relevant parameters from
the database of an otoneurological expert system ONE. The records of patients
with benign positional vertigo, Meniere's disease, sudden deafness, traumatic
vertigo, vestibular neuritis and vestibular schwannoma were retrieved from the
database of ONE, and for each disease, decision trees were constructed. The study
shows that decision tree induction is a useful technique for acquiring diagnostic
knowledge for otoneurological diseases and for extracting relevant parameters
from a large set of parameters.
PMID- 10674420
TI - A tool for designing digital test objects for module performance evaluation in
medical digital imaging.
AB - Currently, medical digital imaging systems are characterized by the introduction
of additional modules such as digital display, image compression and image
processing, as well as film printing and digitization. These additional modules
require performance evaluation to ensure high image quality. A tool for designing
computer-generated test objects applicable to performance evaluation of these
modules is presented. The test objects can be directly used as digital images in
the case of film printing, display, compression and image processing, or
indirectly as images on film in the case of digitization. The performance
evaluation approach is quality control protocol based. Digital test object design
is user-driven according to specifications related to the requirements of the
modules being tested. The available quality control parameters include
input/output response curve, high contrast resolution, low contrast
discrimination, noise, geometric distortion and field uniformity. The tool has
been designed and implemented according to an object oriented approach in Visual
C++ 5.0, and its user interface is based on the Microsoft Foundation Class
Library version 4.2, which provides interface items such as windows, dialog
boxes, lists, buttons, etc. The compatibility with DICOM 3.0 part 10 image
formats specifications allows the integration of the tool in the existing
software framework for medical digital imaging systems. The capability of the
tool is demonstrated by direct use of the test objects in case of image
processing, and indirect use of the test objects in case of film digitization.
PMID- 10674421
TI - Lotka's law and the pattern of scientific productivity in the dental science
literature.
AB - Statistical regularities can be observed in many natural and social phenomena.
From empirical data on the authorship of scientific papers, Lotka deduced an
inverse-square law: the number of authors publishing n papers is 1/n2 of those
publishing one paper. The general type for the relation (1/n(c)) has a wide range
of applicability to a variety of phenomena. This study examined, by means of
bibliometric tools, whether Lotka's law could be applied to the literature of
dental science. Data came from 20 leading dental science journals, as reported in
Journal Citation Reports. The search was performed with a programme developed
using Visual Basic for Applications, which counted the number of authors and
analysed their contributions to the literature. Authorship for all contributions,
as reported in Medline, was compiled for each of these 20 journals for the last
25 years, 1971 through 1995. The total number of authors was 43,796, responsible
for 124,556 authorships. The journals published in countries other than the USA
exhibited higher degrees of author concentration. The dental science literature
conformed very well to Lotka's model with c = 1.95.
PMID- 10674422
TI - Memory and mental status correlates of modified Braak staging.
AB - We assessed the relationships of performance on memory and mental status tests
and neuropathologic stage of Alzheimer's disease as defined by Braak and Braak in
29 patients from a prospective clinicopathologic series. We predicted that memory
changes would occur at an earlier Braak stage than mental status changes. Staging
was accomplished by matching the topographic distribution of neurofibrillary
lesions detected with tau immunocytochemistry to the best fitting diagram
published by Braak and Braak. Higher Braak stages were associated with decrements
in performance on both memory and mental status tests. As predicted, memory
performance declined from stages II to III and mental status did not decline
until stages III to IV. The association between memory and Braak stage was
unchanged after adjusting for neocortical senile plaques, whereas adjustments for
Braak stage eliminated the association between cognitive functioning and amyloid
burden. We conclude that Braak staging provides a useful summary of Alzheimer's
disease neuropathology, which is associated with both memory and mental status
performance.
PMID- 10674424
TI - Sex differences in prefrontal volume with aging and Alzheimer's disease.
AB - We used volumetric magnetic resonance imaging to examine sex differences in
prefrontal tissue volumes of healthy aged and patients with Alzheimer's disease
(AD). Healthy subjects had greater total prefrontal volume than AD, and men had
greater total prefrontal volume than women (ps < or = 0.02). This was true for
both gray and white matter volumes. There were no interactions between group and
sex for total prefrontal volume. An exploratory analysis of each group suggested
that sex differences in both gray and white matter in healthy aging are not
sustained in AD.
PMID- 10674423
TI - Evidence for glial-mediated inflammation in aged APP(SW) transgenic mice.
AB - Chronic expression of inflammatory cytokines, including interleukin-1beta, tumor
necrosis factor alpha, and interleukin-6, by glia may underlie the
neurodegenerative events that occur within the brains of patients with
Alzheimer's disease (AD). The present study determined whether these markers of
inflammation could be observed within the brains of Tg(HuAPP695.K670N/M671L)2576
transgenic mice (Tg2576) that have recently been shown to mimic many features of
AD. Interleukin-1beta- and tumor necrosis factor alpha-immunopositive microglia
were localized with thioflavine-positive (fibrillar) Abeta deposits. Moreover,
interleukin-6 immunoreactive astrocytes surrounded fibrillar Abeta deposits.
These findings provide evidence that Tg2576 mice exhibit features of the
inflammatory pathology seen in AD and suggest that these mice are a useful animal
model for studying the role inflammation may play in this disease.
PMID- 10674425
TI - L-type calcium channels in the hippocampus and cerebellum of Alzheimer's disease
brain tissue.
AB - There is growing evidence that the selective neuronal cell death observed in
Alzheimer's Disease (AD) is the result of dysregulation of intracellular calcium
(Ca2+) homeostasis. In the present study, L-type voltage sensitive calcium
channels (L-VSCCs) were examined in the cerebellum and hippocampus of AD (n = 6;
postmortem interval less than 5 h) and age-matched control (n = 6) tissue by
homogenate binding techniques and quantitative in vitro receptor autoradiography
using [3H]isradipine (PN200-110). Saturation analyses of the cerebellum revealed
unaltered [3H]isradipine binding parameters (Kd and Bmax) between AD and control
subjects. Analysis of AD and control hippocampus demonstrated significant
differences as [3H]isradipine binding increased (62%) in AD, whereas hippocampal
cell density decreased (29%) in AD, relative to control subjects. Moreover, AD
differentially affected L-VSCC in area CA1 and dentate gyrus. The dentate gyrus
had greatly increased binding (77%) with little cell loss (16%) in AD brains,
whereas area CA1 had increased binding (40%) with significant cell loss (42%) in
AD brains, relative to controls. The results of the present study suggest that
hippocampal area CA1 may experience greater cell loss in response to increased L
VSCCs in AD relative to other brain regions.
PMID- 10674426
TI - Decline in visual attention and spatial memory in aged rats.
AB - The present study was a longitudinal study of age-related changes in performance
of the 5-choice serial reaction time task, a test of visual attention. Following
acquisition of the task, animals were tested on two occasions on their ability to
perform the 5-choice task. In Test 1 (Young: 7 months; Aged: 13-14 months) no age
related effects on baseline performance were revealed. However, increasing the
attentional load of the task revealed an impairment in choice accuracy by animals
of the Aged group. In Test 2 (Young: 10-11 months; Aged 23-24 months), animals of
the Aged group were significantly impaired on the baseline schedule of the task
compared to the Young group. The deficit in accuracy on the task could be
improved in the Aged animals by decreasing the attentional load. The results of
the present study suggest a deficit in attentional function as a result of the
aging process, markedly similar to that observed following lesions of the basalo
cortical cholinergic system.
PMID- 10674427
TI - Impairments in acquisition and reversals of two-choice discriminations by aged
rhesus monkeys.
AB - The ability to learn and perform reversals of two object, two patterns, and one
spatial discrimination was examined in eight aged (28-34 years), and four adult
(8-13 years) behaviorally naive monkeys. As a group, the aged monkeys
demonstrated significant difficulties in learning and reversing some of the
visual discrimination problems, but had no difficulty learning or reversing the
spatial discrimination. Additional analyses revealed that an impairment in
learning an object discrimination by the aged monkeys was characterized by a
prolonged period of chance performance, and the impairments in performing visual
discrimination reversals was related to difficulties in two distinct stages of
reversal learning. Despite age-related differences, there was considerable
variability in performance among the aged monkeys. These experiments provide the
first evidence of significant impairments in learning and reversing visual
discriminations by aged monkeys that have not had prior exposure to complex
behavioral tasks.
PMID- 10674428
TI - Age-related working memory deficits in the allocentric place discrimination task:
possible involvement in cholinergic dysfunction.
AB - It is well known that learning and memory ability declines with aging. Age
related long-term changes in learning and memory ability in rats were
investigated with the place navigation task and the allocentric place
discrimination task (APDT) in a water maze using the same animals for each task.
In a working memory place navigation task, aged animals could learn the location
of the platform as well as when they were young, although strategy shifts were
observed. In contrast, accuracy in the APDT significantly declined from 90% to
65% with aging. This impairment was ameliorated by an acetylcholine esterase
inhibitor physostigmine at 22-23 months old. No amelioration was, however,
detected in the same animals tested when they further aged to 26-27 months old.
These results suggest that the APDT performance is sensitive to age-related
memory deficits and that this may be due to the cholinergic dysfunction.
PMID- 10674429
TI - Effects of advanced aging on plasma catecholamine responses to the cold pressor
test.
AB - Increased basal norepinephrine (NE) concentrations have been demonstrated
repeatedly in human aging, but these studies have included almost exclusively
"early aging" subjects younger than age 75. We asked if "advanced aging" (over
age 80) enhanced the effects of early aging on plasma NE and epinephrine (EPI)
concentrations at rest and in response to the cold pressor test (CPT). Eight
medically well, cognitively intact advanced aging subjects (84.4+/-0.9 years), 28
medically well cognitively intact early aging subjects (70.3+/-1.3 years), and 19
medically well young subjects (25.4+/-0.9 years) were studied. Both basal NE and
the acute NE increase after CPT were significantly higher in advanced aging than
in either early aging or young subjects. Plasma EPI concentrations were higher in
the advanced aging group than in the other groups and an acute plasma EPI
increase after CPT occurred only in the advanced aging group. These results
suggest specific effects of advanced aging on both the sympathoneural and
sympathoadrenomedullary components of the sympathetic nervous system.
PMID- 10674430
TI - Age-related changes in oxidative mechanisms and LTP are reversed by dietary
manipulation.
AB - Aged rats exhibit an impaired ability to sustain long-term potentiation in
dentate gyrus which correlates with a decrease in arachidonic acid concentration.
Here we confirm the previous finding that dietary supplementation with
arachidonic acid and its precursor, gamma-linolenic acid, reversed the impairment
in LTP in aged rats and report that there is a significant correlation between
membrane arachidonic acid concentration and response to tetanic stimulation. We
observed that age was associated with decreases in the concentration of vitamins
C and E and increased activity of superoxide dismutase, indicative of a
compromise in antioxidative defenses; these changes were paralleled by increases
in interleukin-1beta (IL-1beta) concentration and lipid peroxidation. Dietary
manipulation restored polyunsaturated fatty acid concentrations to values
observed in tissue prepared from young rats and reversed the age-related changes
in vitamins E and C, IL-1beta concentration and superoxide dismutase activity. We
propose that these changes reverse the increase in lipid peroxidation and thereby
the age-related change in polyunsaturated fatty acids.
PMID- 10674431
TI - Age-related changes in LTP and antioxidant defenses are reversed by an alpha
lipoic acid-enriched diet.
AB - Among the age-related changes identified in rat hippocampus are impairments in
LTP and glutamate release. These deficits have been coupled with decreased
arachidonic acid concentration. In this study we compared LTP and glutamate
release in groups of aged and young rats fed for 8 weeks on a control diet or on
a diet enriched in alpha-lipoic acid. Dietary supplementation in aged rats
restored hippocampal arachidonic acid concentration to levels observed in tissue
prepared from young rats. We observed that aged rats that received the
experimental diet sustained LTP in perforant path-granule cell synapses in a
manner indistinguishable from young rats whereas the age-related impairment in
glutamate release was reversed in synaptosomes prepared from dentate gyrus
obtained from these rats. The evidence presented supports the hypothesis that the
alpha-lipoic acid-enriched diet has antioxidant properties, because the age
related increase in superoxide dismutase activity and decrease in alpha
tocopherol concentration were reversed. The finding that the age-related increase
in interleukin-1 (IL-1)beta concentration was also reversed suggests a possible
role for this cytokine in ageing.
PMID- 10674432
TI - Aging does not affect the sleep endocrine response to total sleep deprivation in
humans.
AB - Aging is associated with decreased sleep continuity, slow wave sleep (SWS),
growth hormone (GH) release and an increased hypothalamo-pituitary-adrenocortical
(HPA) system activity. Total sleep deprivation (TSD) is a strong stimulus for
sleep. To determine if aging affects the response to TSD, for the first time the
combined effects of TSD on conventional and spectral sleep
electroencephalographic (EEG) parameters and GH, cortisol and prolactin secretion
were compared in elderly (60-80 years; n = 7) vs. younger subjects (20-30 years;
n = 7). MANOVA revealed a reduction of SWS in the elderly. TSD led to an increase
in SWS, a decrease in sleep onset latency, rapid eye movement (REM) density and
by trend REM-latency without a global group difference. GH was reduced, whereas
prolactin was enhanced in the elderly. After TSD GH was unchanged and prolactin
secretion was enhanced without group difference. Thus, the plasticity of the
sleep-endocrine system in response to TSD is sustained during aging. The possible
involvement of the GABAergic system, that seems not to be severely impaired with
age, is proposed.
PMID- 10674433
TI - EEG delta power during sleep in young and old rats.
AB - Delta EEG power density, which has been viewed as a measure of intensity of NREM
sleep, declines across the lifetime in humans, cats, and hamsters, but data in
rats have been unclear. It is also uncertain whether older rats differ from
younger animals in the degree of change in delta power during recovery sleep
following short-term sleep deprivation. We have examined delta power density in
NREM sleep under baseline conditions and following 48 h of sleep deprivation in
young (3 months), middle-aged (12 months), and older (24 months) rats. The
presence or absence of age effects was highly dependent on the method of
normalizing the data. When expressed as a fraction of total NREM EEG power, there
was no age effect on baseline delta power density, or on the change from baseline
to recovery conditions. When expressed as a multiple of delta power in REM under
the same condition, the younger rats had higher delta power density than the
middle-aged and older rats. For all the ages combined, there was an increase in
delta power density in the recovery condition. When examined by age, the younger
rats (which started from a higher level of delta power density than the other
groups) did not have an increase in delta during recovery; the middle-aged rats
tended to, and the older rats (which started from lower baseline levels)
significantly increased delta power density in the recovery condition. This
suggests that the lower delta power seen during baseline in older rats is not due
to decreased ability to generate delta activity.
PMID- 10674434
TI - Excitability and branching of neuroendocrine cells during reproductive
senescence.
AB - In the mollusc Lymnaea stagnalis, neuroendocrine caudodorsal cells (CDCs) were
studied physiologically and morphologically from egg layers (EL) (aged 154-400),
and animals 4 weeks (CEL-4) (342-455 days), and 8 weeks (CEL-8) (477-660 days)
after production of their last egg mass. After recording chemical transmission,
electrical coupling and stimulation induced afterdischarges (ADs), CDCs then were
filled with Lucifer Yellow. Based on the axonal branching revealed by Lucifer
Yellow, CDCs were classified as extensively, moderately, or minimally branched.
In EL-CDCs, induction of AD activity, which normally (9) precedes egg-laying,
only was initiated in the resting state. CEL-4 CDCs exhibited ADs whereas CEL-8
CDCs did not. CEL-8 CDCs exhibited significantly reduced chemical and electrical
transmission, and CEL-4 CDCs did not differ from resting state EL-CDCs. CDC
branching was significantly reduced with both increasing age and declining egg
laying. Minimally branched CDCs most frequently failed to exhibit an AD and
exhibited reduced electrical coupling. We conclude that both physiology and
morphology of CDCs are related to age and reproductive state.
PMID- 10674435
TI - NGF expression in the aged rat pineal gland does not correlate with loss of
sympathetic axonal branches and varicosities.
AB - The factors that determine the ability of some, but not all neurons, to sustain
their axonal projections during aging remain largely unknown. Because sympathetic
neurons remain responsive to nerve growth factor (NGF) in old age, it has been
proposed that the selective decrease observed in the sympathetic innervation to
some targets in aged rats may be the result of a deficit in target-derived NGF.
In this study we utilized two different techniques to demonstrate decreased
target innervation by sympathetic fibers in the aged rat pineal gland, which is
an appropriate and relevant model for examining mechanisms of neuron-target
interactions in aging. Tyrosine hydroxylase immunoreactive profiles were
quantified in pineal glands of young and aged male Sprague-Dawley rats. The
density of tyrosine hydroxylase-immunoreactive fibers was 30% lower in aged
pineals, although the remaining fibers contained 20% more tyrosine hydroxylase
immunoreactivity. Othograde tracing of the pineal sympathetic innervation using
biotinylated dextran revealed that average axon length, varicosity numbers,
branch point numbers, and numbers of terminations were all decreased by
approximately 50% in aged tissues, indicating possible functional deficits. These
findings suggest that whole branches, along with their associated varicosities
were lost in old age. A sensitive quantitative ribonuclease protection assay and
a two-site ELISA assay were used to examine whether reduced NGF availability
might correlate with sympathetic nerve atrophy. No significant differences were
detected in either NGF mRNA or NGF protein levels when comparing young and aged
pineal glands, suggesting that atrophy in aged sympathetic neurons is not
causally related to reduced availability of NGF at the target. Our results
indicate that mechanisms other than NGF expression need to be explored in order
to explain the age-related axonal regression observed in this target.
PMID- 10674436
TI - Influence of aging on thromboxane A2 and prostacyclin levels in rat hippocampal
brain slices.
AB - We have investigated the influence of age (3, 18, 24 months) on Thromboxane A2
(TXA2) and Prostacyclin (PGI2) levels in hippocampal slices from F344/NHSD rats.
A significant increase in TXA2 and PGI2 levels was observed in 18 and 24 months
old compared to 3 months old animals. A significant reduction in the ratio
TXA2/PGI2 produced by a higher increase in PGI2 was observed in 24 month old
animals. The reduction in the TXA2/PGI2 ratio has been related to vasodilatory
and antiaggregating effects that may contribute to protect the brain against
neuronal damage.
PMID- 10674437
TI - Age differences in the response to the formalin test in rats.
AB - We report the results of a study designed to assess age differences in the
response to the formalin test, a model of tissue injury and inflammation, while
controlling for differences in weight and motoric abilities in three groups of
adult male Long-Evans rats: young (3 months old), middle-aged (18 months old),
and old (24 months old). The first part of the study assessed initial differences
in responsivity and found that the middle-aged group showed the greatest
response, whereas the young and old groups did not differ from each other. In the
second part of the study, the young and middle-aged animals were followed for a 4
month period. The formalin test was repeated at 2-month intervals. These results
indicate that there may be an age-associated change in the sensitivity to tonic
pain and that this sensitivity may peak at mid-life.
PMID- 10674438
TI - Long-term effects of pergolide and (-)-deprenyl on 3H-mazindol and 3H-spiperone
binding in rat brain.
AB - The effects of long-term administration of the putative neuroprotective agents
pergolide and (-)-deprenyl was assessed by studying 3H-mazindol and 3H-spiperone
binding at 12 and 20 months in the major dopamine brain regions. Male Wistar rats
were treated from 3 to 20 months, together with their respective untreated and
saline injected control groups. The main findings were: 1) there was a decrease
in both 3H-mazindol and 3H-spiperone binding with age between 12 and 20 months;
2) there were no differences at 20 months between the pergolide or the (-)
deprenyl treated groups and their controls, thus providing no evidence for long
term neuroprotection; and 3) there was a marked decrease in 3H-mazindol binding
in the injected controls compared with the untreated controls at both 12 and 20
months. This raises the possibility that mild chronic stress may accelerate the
aging of the dopamine system.
PMID- 10674439
TI - Urinary diversion: the patient's choice.
PMID- 10674440
TI - Follow-up is valuable and effective: true, true and unrelated?
PMID- 10674441
TI - The type of urinary diversion after radical cystectomy significantly impacts on
the patient's quality of life.
AB - BACKGROUND: In this study, we used a previously well-validated survey to assess
the impact of different forms of urinary diversion on overall quality of life in
patients with bladder cancer. METHODS: A total of 92 patients, having three
different forms of urinary diversion after radical cystectomy, completed by mail
the SF-36, a validated quality-of-life survey. All patients had local/regional
disease at the time of cystectomy and are currently without evidence of disease.
Completed surveys were then analyzed into physical (PCS) and mental (MCS)
component quality-of-life scores per published protocols. Results were then
compared with published age-based norms. RESULTS: A total of 38 men who had
cystectomy and ileal neobladder had a mean PCS (+/- SD) of 48.4 (7.8) and a mean
MCS of 51.0 (7.4); 16 men and women who had cystectomy and Indiana Pouch had a
mean PCS of 48.4 (8.9) and a mean MCS of 55.7 (3.8). None of these results is
statistically different from published age- and sex-based population norms.
Thirty-eight men who had cystectomy and ileal conduit had a mean PCS of 41.4
(8.5) and a mean MCS of 48.2 (10.7). The PCS is not statistically different from
the population-based norm; however, the MCS is significantly decreased from the
published norm (P = .01). CONCLUSIONS: Patients with ileal conduits have
significantly decreased mental health quality of life whereas patients with
continent urinary diversions do not. Therefore, when not medically
contraindicated, patients should be offered a continent diversion as the
diversion of choice after cystectomy.
PMID- 10674442
TI - Primary extremity sarcoma: what is the appropriate follow-up?
AB - BACKGROUND: Our objective was to evaluate the effectiveness of follow-up tests
for detecting first local and distant recurrences in patients with primary
extremity soft tissue sarcoma. METHODS: We retrospectively analyzed all adult
cases of primary extremity soft tissue sarcoma (n = 174) treated between 1982 and
1992. Patients were observed every 3 months for 2 years, every 4 months the third
year, every 6 months the next 2 years, and annually, thereafter. Each visit
consisted of taking the patient's history, a physical examination, a complete
blood count, a blood chemistry panel, and a chest x-ray. For high-grade tumors,
the primary site was imaged annually when clinically appropriate. RESULTS: Of 141
patients who were assessable, 29 patients developed local recurrence and 57
developed distant recurrence. All but one of the local recurrences was detected
on the basis of an abnormal physical examination. Of the 29 patients who
developed local recurrence, 25 were resected. Distant metastases were detected
because of symptoms in 21 cases. Of the 36 asymptomatic lung recurrences, 30 were
detected by follow-up chest x-ray. Of the 36 asymptomatic lung recurrences, 24
patients underwent metastasectomy. The positive and negative predictive values of
surveillance chest x-ray were 92% and 97%, respectively. Laboratory testing never
led to the detection of recurrence. CONCLUSIONS: Close surveillance by clinical
assessment and chest x-ray is appropriate for follow-up observation of patients
with primary extremity soft tissue sarcoma.
PMID- 10674443
TI - Sentinel node biopsy in ductal carcinoma in situ patients.
AB - BACKGROUND: Sentinel lymph node (SLN) mapping is an effective and accurate method
of evaluating the regional lymph nodes in breast cancer patients. The SLN is the
first node that receives lymphatic drainage from the primary tumor. Patients with
micrometastatic disease, previously undetected by routine hematoxylin and eosin
(H&E) stains, are now being detected with the new technology of SLN biopsy,
followed by a more detailed examination of the SLN that includes serial
sectioning and cytokeratin immunohistochemical (CK IHC) staining of the nodes.
METHODS: At Moffitt Cancer Center, 87 patients with newly diagnosed pure ductal
carcinoma in situ (DCIS) lesions were evaluated by using CK IHC staining of the
SLN. Patients with any focus of microinvasive disease, detected on diagnostic
breast biopsy by routine H&E, were excluded from this study. DCIS patients, with
biopsy-proven in situ tumor by routine H&E stains, underwent intraoperative
lymphatic mapping, using a combination of vital blue dye and technetium-labeled
sulfur colloid. The excised SLNs were examined grossly, by imprint cytology, by
standard H&E histology, and by IHC stains for CK. All SLNs that had only CK
positive cells were subsequently confirmed malignant by a more detailed
histological examination of the nodes. RESULTS: CK IHC staining was performed on
177 SLNs in 87 DCIS breast cancer patients. Five of the 87 DCIS patients (6%) had
positive SLNs. Three of these patients were only CK positive and two were both
H&E and CK positive. Therefore, routine H&E staining missed microinvasive disease
in three of five DCIS patients with positive SLNs. In addition, DCIS patients
with occult micrometastatic disease to the SLN underwent a complete axillary
lymph node dissection, and the SLNs were the only nodes found to have metastatic
disease. Of interest, four of the five node-positive patients had comedo
carcinoma associated with the DCIS lesion, and one patient had a large 9.5-cm low
grade cribriform and micropapillary type of DCIS. CONCLUSIONS: This study
confirms that lymphatic mapping in breast cancer patients with DCIS lesions is a
technically feasible and a highly accurate method of staging patients with
undetected micrometastatic disease to the regional lymphatic basin. This
procedure can be performed with minimal morbidity, because only one or two SLNs,
which are at highest risk for containing metastatic disease, are removed. This
allows the pathologist to examine the one or two lymph nodes with greater detail
by using serial sectioning and CK IHC staining of the SLNs. Because most patients
with DCIS lesions detected by routine H&E stains do not have regional lymph node
metastases, these patients can safely avoid the complications associated with a
complete axillary lymph node dissection and systemic chemotherapy. However, DCIS
patients with occult micrometastases of the regional lymphatic basin can be
staged with higher accuracy and treated in a more selective fashion.
PMID- 10674444
TI - Biopsy method and excision volume do not affect success rate of subsequent
sentinel lymph node dissection in breast cancer.
AB - INTRODUCTION: Sentinel lymph node dissection (SLND) is becoming a recognized
technique for accurately staging patients with breast cancer. Its success in
patients with large tumors or prior excisions has been questioned. The purpose of
this study was to evaluate the effect of biopsy method, excision volume, interval
from biopsy to SLND, tumor size, and tumor location on SLND success rate.
METHODS: Consecutive patients who underwent SLND followed by completion axillary
lymph node dissection from October 1991 to December 1995 were analyzed. Included
were cases performed early in the series before the technique was adequately
developed. Excision volume was derived from the product of three dimensions as
measured by the pathologist. Two end points were analyzed: sentinel node
identification rate and accuracy of SLND in predicting axillary status.
Univariate analyses using chi2 or Fisher's exact test for categorical variables
and Wilcoxon rank sums for continuous variables were performed. Multivariate
analysis was performed using logistic regression. RESULTS: There were 284 SLND
procedures performed on 283 patients. Median age was 55 years. The most recent
biopsy method used before SLND was stereotactic core biopsy in 41 (14%), fine
needle aspiration in 62 (22%), and excision in 181 (64%) procedures. The mean
excision volume was 32 ml with a range of 0.3-169 ml. The mean time from biopsy
to SLND was 17 days with a range of 0-140 days. The mean tumor size was 2.0 cm
(15 Tis [5%], 184 T1 [65%], 72 T2 [25%], and 13 T3 [5%]). Tumors were located in
the outer quadrants in 74%, the inner quadrants in 18%, and subareolar region in
8%. The sentinel node was identified in 81%, and 39% had metastases. There were
three false-negative cases early in the series. Sensitivity was 97%, and accuracy
was 99%. Negative predictive value was 98% in cases in which the sentinel node
was identified. On the basis of biopsy method, excisional volume, time from
biopsy to SLND, tumor size, and tumor location, there was no statistically
significant difference (P>.05) in sentinel node identification rate or accuracy
of SLND. CONCLUSIONS: SLND has a high success rate in breast cancer patients
regardless of the biopsy method or the excision volume removed before SLND. In
addition, the interval from biopsy to SLND, tumor size, and tumor location have
no effect on the success rate of SLND, even in this series which included
patients operated on before the technique was adequately defined. Patients with
breast cancers located in any quadrant and diagnosed either with a needle or
excisional biopsy could be evaluated for trials of SLND.
PMID- 10674445
TI - Radioguided sentinel node biopsy to avoid axillary dissection in breast cancer.
AB - BACKGROUND: Sentinel node (SN) biopsy may predict axillary status in breast
cancer. We retrospectively analyzed more than 500 SN cases, to suggest more
precise indications for the technique. METHODS: 99mTc-labeled colloid was
injected close to the tumor; lymphoscintigraphy was then performed to reveal the
SN. The next day, during surgery, the SN was removed by using a gamma probe.
Complete axillary dissection followed, except in later cases recruited to a
randomized trial. The SN was examined intraoperatively by conventional frozen
section, in later cases by sampling the entire node and using
immunocytochemistry. RESULTS: In the first series, the SN was identified in 98.7%
of cases; in 6.7%, the SN was negative but other axillary nodes were positive; in
32.1%, the SN was negative by intraoperative frozen section but metastatic by
definitive histology, prompting introduction of the exhaustive method. In the
randomized trial, the SN was identified in all cases so far, the false-negative
rate is approximately 6.5%, and in 15 cases, internal mammary chain nodes were
biopsied. CONCLUSIONS: SN biopsy can reliably assess axillary status in selected
patients. The problems are the SN detection rate, false negatives, and the
intraoperative examination, which can miss 30% of SN metastases. Our exhaustive
method overcomes the latter problem, but it is time consuming.
PMID- 10674446
TI - Is intensive follow-up really able to improve prognosis of patients with local
recurrence after curative surgery for rectal cancer?
AB - BACKGROUND: Because more than 90% of local recurrences after curative surgery for
rectal cancer appear within the first 36 months after surgery, an intensive and
strict follow-up program during this period could improve early diagnosis and,
thus, prognosis of patients. METHODS: Of the 216 patients who underwent surgery
for rectal cancer, 127 entered an intensive follow-up program (median follow-up:
42 months); the clinical outcome of the remaining 89 patients was reconstructed
with the help of their general practitioners. RESULTS: Fifty eight (26.8%) of the
216 patients who were treated with curative surgery alone developed a local
recurrence; pelvic recurrences were prevalent. Eleven (30.5%) of the 36 patients
who had recurrence during follow-up, and 6 of the 22 who had not undergone follow
up, had a reoperation with curative intent; the median survival was 19 months vs.
8 months, respectively (P = ns). Four (44.4%) curative reoperations were
performed on the 9 asymptomatic patients and in 13 (26.5%) of the 49 cases with
symptomatic local recurrences. Median survival was 15 months vs. 14 months,
respectively (P = n.s). All patients except one (living after 42 months from
reoperation) died within 48 months. CONCLUSIONS: In our study, adherence to a
strict follow-up program unfortunately proved to be ineffective for improving
long-term survival for patients who underwent reoperation with curative intent.
PMID- 10674447
TI - Preoperative combined radiotherapy and chemotherapy for middle and lower rectal
cancer: preliminary results.
AB - BACKGROUND: Adjuvant treatment for rectal cancer is still controversial. This
study reports on overall survival and disease-free survival, toxicity,
downstaging, and surgical morbidity in rectal cancer patients who received
combined chemoradiation therapy followed by curative surgery. METHODS: Between
1993 and 1998, 51 patients (31 males and 20 females; median age, 60 years; range,
33-73 years) underwent chemoradiation therapy followed by radical surgery for
middle and lower rectal adenocarcinoma. Criteria for giving preoperative
radiotherapy (total 45 Gy in 25 fractions of 1.8 Gy/day for 5 weeks) and
chemotherapy (5-fluorouracil 350 mg/m2/day and leucovorin 10 mg/m2/day, bolus on
days 1-5 and 29-33) were an age younger than 75 years; an Eastern Cooperative
Oncology Group performance status score of 0 to 2; and clinical preoperative
stage II-III. Forty-three low anterior and eight abdominoperineal resections were
performed. Median follow-up time was 29 (range, 3-63) months. RESULTS: Although
grade 3 to 4 toxicity occurred in 14 cases (27.4%), all patients completed the
planned adjuvant therapy. At pathology, a complete response was found in eight
(15.7%) cases. Of the remaining 43 cases, 22 were stage I, 12 were stage II, and
9 were stage III. Five-year actuarial disease-free survival and overall survival
rates were 86.4% and 85.5%, respectively. Whereas no local recurrences were
found, 4 patients had distant metastases. Three patients died (1 of cancer
related causes), 45 are alive and disease free, and 3 are alive with disease.
CONCLUSIONS: The combined preoperative chemoradiation approach used by us seems
to improve the disease-free survival and overall survival of selected patients
with rectal cancer. However, a longer follow-up time is required to confirm these
preliminary results.
PMID- 10674448
TI - Neoadjuvant chemotherapy with P-ELF (cisplatin, etoposide, leucovorin, 5
fluorouracil) followed by radical resection in patients with initially
unresectable gastric adenocarcinoma: a phase II study.
AB - BACKGROUND: Gastric cancer is the most frequent gastrointestinal cancer in
Mexico. Only 33% of cases are resectable. Our aim was to determine the activity
and toxicity of the cisplatin, etoposide, leucovorin, and 5-fluorouracil
combination in initially unresectable tumors and to determine its ability to
permit resection. METHODS: Sixty patients with unresectable gastric
adenocarcinoma were treated with cisplatin 80 mg/m2, etoposide 80 mg/m2,
leucovorin 25 mg/m2, and 5-fluorouracil 800 mg/m2 by central intravenous catheter
for 4 consecutive days. Two courses of this combination were followed by surgical
resection. RESULTS: The overall response rate was 36.8% (20 partial responses and
one complete response). By using logistic regression analysis, the tumor, node,
and metastasis stage (risk ratio, 2.04; 95% confidence interval, 1.03-4.02; P =
.039) was identified as the response determinant to chemotherapy. Major toxicity
was grade 3 or 4 neutropenia in 67% of patients. Ten resections were performed
(17.5%); five were curative and five palliative. Operative morbidity and
mortality rates were 40% and 10%, respectively. The median length of survival was
7.46 and 13.3 months for nonresponders and responders, respectively (P = .011).
CONCLUSIONS: The cisplatin, etoposide, leucovorin, and 5-fluorouracil combination
is active in advanced gastric cancer and the toxicity level is acceptable. This
treatment permits a 17.5% resection rate in previously unresectable tumors. A
randomized trial of surgery vs. neoadjuvant chemotherapy plus surgery is
warranted.
PMID- 10674449
TI - Sentinel node biopsies in melanoma patients: a protocol for accurate, efficient,
and cost-effective analysis by preselection for immunohistochemistry on the basis
of Tyr-PCR.
AB - BACKGROUND: Immunohistochemistry (IHC) of serial sectioning is considered the
gold standard for detection of melanoma activity in sentinel node (SN) biopsies.
However, this is cost and labor intensive. In contrast, tyrosinase reverse
transcription-polymerase chain reaction (RT-PCR) is simple and quick, but it is
hampered by its extreme sensitivity. This study was performed to test whether a
strategy that combines the two methods, using tyrosinase RT-PCR to preselect
nodes for IHC, could be accurate and cost effective. METHODS: In 36 patients, SNs
were identified by scintigraphy and patent blue uptake. Of each SN, one cross
section was analyzed first by hematoxylin and eosin staining. Next, all nodes
were examined by serial sectioning and IHC of one-half and tyrosinase RT-PCR of
the other. Before comparison, all results were documented in a blinded manner.
Material costs and workload estimates were noted per SN. RESULTS: Fifty-five SNs
were retrieved from the 36 patients. Hematoxylin and eosin staining of the first
cross section revealed tumor positivity in 3 patients (6 SN). Tyrosinase RT-PCR
was positive in 11 of the remaining 33 patients (19 of 49 SN). Of these same 11
patients, only 5 were shown to have tumor-positive SNs by using IHC on serial
sections (7 SN). All these nodes had been positive for tyrosinase on PCR. For
IHC, an average of 40 sections were prepared and examined per SN at a cost of
$200(U.S.)/SN. In contrast, routine tyrosinase RT-PCR costs $37(U.S.)/SN, and
takes 5% of the time necessary for IHC. A strategy including hematoxylin and
eosin staining on the first cross section, followed by tyrosinase RT-PCR on half
of each negative (half) node, could preselect nodes to be taken through serial
sectioning. In these series, such a strategy would have prevented serial
sectioning and IHC of 30 SN from 22 patients. Apart from a considerable gain in
efficiency, this would have reduced material costs by a minimum of $6000 (U.S.).
This discrepancy would be even higher if work intensity of analysts and
pathologists were considered. CONCLUSIONS: In routine analysis of SN biopsies in
melanoma patients, tyrosinase RT-PCR can be used effectively to preselect nodes
for further IHC of serial sections. This method seems both time and cost
effective.
PMID- 10674450
TI - Hilar cholangiocarcinoma: a review and commentary.
AB - Hilar cholangiocarcinoma is an uncommon cause of malignant biliary obstruction
marked by local tumor spread for which surgery offers the only chance of cure.
The diagnostic evaluation and surgical management of this disease continues to
evolve. Although direct cholangiography and endoscopic biliary procedures have
been used extensively to anatomically define the extent of tumor involvement,
establish biliary decompression, and obtain histological confirmation of tumor,
reliance on these invasive procedures is no longer necessary, and may be
detrimental. Current noninvasive imaging technology permits accurate staging of
the primary tumor and has improved patient selection for operative intervention
without the need for invasive procedures. Overall survival has improved in
accordance with an increasingly aggressive surgical approach. The propensity of
this tumor for local invasion has led most experienced hepatobiliary centers to
perform a partial hepatectomy in 50% to 100% of cases. Three-year survival rates
of 35% to 50% can be achieved when negative histological margins are attained at
the time of surgery. When resection is not feasible, either operative
bilioenteric bypass or percutaneous transhepatic intubation can achieve
significant palliation. There is no effective adjuvant therapy for this disease,
and unless clear indications of unresectability exist, most patients should be
considered for surgical exploration.
PMID- 10674451
TI - Tamoxifen for the prevention of breast cancer in the high-risk woman.
PMID- 10674452
TI - Time course of nodal enhancement with CT X-ray nanoparticle contrast agents:
effect of particle size and chemical structure.
AB - RATIONALE AND OBJECTIVES: Levels of CT enhancement in rabbit lymph nodes were
followed with time after subcutaneous injection of four iodinated, insoluble
nanoparticle contrast agents to provide experimental support for the hypothesis
that clearance of these agents is related to the chemical structure of the agent
itself. The impact of particle size was also studied. METHODS: Subcutaneous
injections (2 x 0.25 mL) were made in the dorsum of rabbit paws with 15%
suspensions of four nanoparticle contrast agents. Images were obtained at 4, 10,
24, 48, and 72 hours and 5, 7, and 14 days after injection. Average attenuation
(in Hounsfield units [HU]), node volume, and total iodine uptake were estimated
from the CT scans for each lymph node at each time point. RESULTS: All the agents
provided adequate enhancement of both the popliteal and axillary lymph nodes of
the rabbit (ie, > delta100 HU). Lymph node volume appears to be related to the
persistence of enhancement, with long-lived agents demonstrating the greatest
increase in size. The rate of clearance from the lymph nodes is related to the
structure of the agent. CONCLUSIONS: Clearance of insoluble, iodinated
nanoparticle contrast agents from lymph nodes can be modulated by changes in the
structure of the agent itself. Using the same agent, smaller particles deliver
material to the lymph nodes more quickly and clear more quickly.
PMID- 10674453
TI - Intravascular ultrasound evaluation of peripheral arterial stent-grafts.
AB - RATIONALE AND OBJECTIVES: To evaluate neointimal hyperplasia, plaque
distribution, and morphologic features of peripheral arterial stent-grafts with
intravascular ultrasound (IVUS). METHODS: Twenty-three patients with stenoses or
occlusions of the pelvic or femoral arteries were treated with 31 stent-grafts.
Angiography and IVUS of the stented artery were performed 13.9 +/- 9.7 months
after stent implantation. Maximum in-stent restenosis was measured by IVUS.
Plaque composition and lesion topography were also assessed. RESULTS: The maximum
in-stent restenosis was 53.2 +/- 26.5% for the femoral and 14.2 +/- 10.1 for
pelvic arterial stent-grafts. Predilection sites of maximum neointimal tissue
accumulation were the edges of the femoral stent-grafts. Only small amounts of
neointimal hyperplasia were found in the stent-graft edges. No predilection site
for maximum in-stent restenosis was found for the pelvic arterial stent-grafts.
CONCLUSIONS: Predilection sites of maximum in-stent restenosis were the edges of
femoral stent-grafts in contrast to pelvic stent-grafts. Femoral stent-grafts
showed significantly higher graded stenoses with IVUS than iliac stent-grafts.
The authors' findings at IVUS did not change the treatment plan in these patients
treated with stent-grafts.
PMID- 10674454
TI - Comparison of harmonic and conventional power Doppler ultrasonography for
assessment of slow flow in hyperechoic tissue: experimental study using a Doppler
phantom.
AB - RATIONALE AND OBJECTIVES: Despite the advantages of depicting slow flow in small
vessels, conventional power Doppler ultrasound (US) has a basic limitation,
specifically that artifactual power Doppler signals mimic blood flow, especially
in hyperechoic tissue. The purpose of this study was to compare harmonic power
Doppler US with power Doppler US using a Doppler phantom under various parameter
settings, focusing on the assessment of slow flow in the hyperechoic tissue.
METHODS: While controlling the flow velocity (5 and 10 cm/s), pulse repetition
frequency (500, 700, and 1,000 Hz), wall filter (low and medium), and Doppler
gain (90%, 96%, and 100%), the authors performed both harmonic Doppler US and
power Doppler US by using a Doppler phantom/flow control system. We measured and
compared the relative intensities of the Doppler signals (0-250 scale) in both
the vessels and hyperechoic tissue-mimicking materials with the two different
imaging modalities. RESULTS: Power Doppler US with any combination of the four
parameters evaluated depicted strong flow signals (mean, 213) that were superior
to harmonic Doppler US (mean, 61). Relatively strong artifactual signals within
the hyperechoic tissue-mimicking materials were noted on all power Doppler US
studies (mean, 106) but nearly none on harmonic Doppler US (mean, 3). The
contrast-to-noise ratio of harmonic Doppler US was significantly greater than
that of power Doppler US. CONCLUSIONS: Harmonic Doppler US is more useful in
assessing slow flow in hyperechoic tissue than power Doppler US because it
produces fewer artifactual Doppler signals originating from stationary
hyperechoic tissues, which can be misjudged as true signals on power Doppler US.
PMID- 10674455
TI - Evaluation of breath-hold contrast-enhanced 3D magnetic resonance angiography
technique for imaging visceral abdominal arteries and veins.
AB - RATIONALE AND OBJECTIVES: To evaluate the diagnostic value of breath-hold
contrast-enhanced 3D magnetic resonance angiography (MRA) for assessment of the
visceral abdominal arteries and veins in patients with suspected abdominal
neoplasms. METHODS: Twenty-one patients underwent MR imaging on a 1.5 T unit
using a body phased-array coil. MRA was performed with a 3D-FLASH sequence (TR
3.8 ms, TE 1.3 ms, flip angle 25 degrees, acquisition time 20 seconds), 8 to 12
seconds after an intravenous bolus injection of Gd-DTPA. The acquisition delay
between the arterial and the portal venous phase was 12 seconds. The image
quality and the degree of vascular involvement were evaluated using coronal
source images and maximum intensity projection reconstructions. Diagnosis was
confirmed by surgery/histology. RESULTS: Image quality was optimal in more than
85% of the patients (19/21 arterial phase and 17/21 portal venous phase). MRA
correctly predicted vascular status in 20 of 21 patients (95%), with complete
concordance between MRA results and surgical findings. In one patient with
chronic pancreatitis, MRA demonstrated a false-positive finding that could not be
confirmed surgically. CONCLUSIONS. Breath-hold contrast-enhanced 3D-MRA is a
valuable technique for assessing visceral abdominal arteries and veins.
PMID- 10674456
TI - Enhanced detection of blood flow in the normal canine prostate using an
ultrasound contrast agent.
AB - RATIONALE AND OBJECTIVES: To evaluate the sonographic appearance of normal
prostate vascularity in dogs before and after injection of a new ultrasound
contrast agent, NC100100. METHODS: Thirty-five intravenous injections of
NC100100, in doses ranging from 0.00625 to 0.05 microL microbubbles/kg, were
administered to seven anesthetized mongrel male dogs. Transrectal color Doppler
imaging and power Doppler imaging were used to perform the assessment. The
visibility of the vascular pattern of the prostate was assessed, including
dynamics of contrast inflow, blood flow symmetry, and duration times. RESULTS:
Before contrast administration, the vascular pattern was poorly visualized in all
cases. After contrast injection, the visibility of the vascular architecture
improved significantly for both modalities. Independent of the imaging method
used, higher doses tended to be more effective than lower doses. Contrast
kinetics in the prostate vessels was demonstrated with a mean time from injection
of the ultrasound contrast agent to enhancement of the Doppler signals in the
subcapsular arteries (+/-1 SD) of 13+/-3 seconds, and the ultrasound contrast
agent reached the central periurethral veins 3 to 6 seconds later. A spokelike
radial pattern of internal prostatic vessels observed with enhanced ultrasound
could also be seen on silicone microfil x-ray images. The Doppler enhancement
persisted for a mean time ( +/-1 SD) of 904 seconds (approximately 15 minutes) +/
225 seconds and tended to increase with increasing dose. CONCLUSIONS: NC100100
significantly improves the detection of blood flow in the normal canine prostate
and allows more accurate depiction of the vascular architecture of the prostate.
PMID- 10674457
TI - Multipoint rank-order study methodology: observer issues.
AB - RATIONALE AND OBJECTIVES: We performed a multipoint rank-order experiment to
evaluate variability in observers' sensitivity to small differences in image
presentation and to assess observers' performance as a function of the type and
number of tasks included. METHODS: Five experienced observers were presented with
four sets of chest images that had been compressed at five different levels. Each
set contained six images ranging from noncompressed to approximately 60:1
compressed images. Observers were asked to review all images of each case side by
side and rank-order the "quality" of each to enable determination of the presence
or absence of interstitial disease and/or pneumothoraces. RESULTS: Observers
varied significantly in their ability to detect very small differences among the
images (P < 0.001). Those who performed well did so regardless of whether they
ranked a specific abnormality in a multidisease or a single-disease setting.
CONCLUSIONS: Selected observers can reliably detect very small differences among
similar images. These readers could be used to confirm or rule out the need for
objective observer-performance-type studies.
PMID- 10674458
TI - Rheolytic hydrodynamic thrombectomy for percutaneous treatment of acutely
occluded infra-aortic native arteries and bypass grafts: midterm follow-up
results.
AB - RATIONALE AND OBJECTIVES: To evaluate the efficacy of a rheolytic thrombectomy
catheter (RTC) for treatment of acutely occluded infra-aortic native arteries and
bypass grafts and to determine midterm primary patency, death, and amputation
free survival rates. METHODS: From March 1995 to September 1997, 112 patients
with occluded arteries or bypass grafts were primarily treated with RTC at two
centers. Thrombus removal was evaluated by two angiographers. RESULTS: More than
75% of the thromboembolic material could be removed with RTC alone. Mean
activation time of RTC was 280 +/- 163 seconds. Residual mural or organized
thrombi (29%) required adjunctive fibrinolytic therapy or aspiration
thrombectomy. Remaining stenoses were treated with percutaneous transluminal
angioplasty and additional stent implantation. For acute reocclusions, surgical
intervention was required. Technical success after the entire procedure was
88.4%. RTC-associated complications included distal embolization, dissection,
vessel perforation, and technical failure of RTC. Mean follow-up time was 14.8
months +/- 11.5, rates of primary patency, secondary patency, death, and
amputation-free survival were 60%, 84%, 16%, and 75% after 2 years, respectively.
CONCLUSIONS: RTC is a rapid and efficient technique for mechanical thrombectomy
of acutely thrombosed native leg arteries and bypass grafts. Midterm results are
comparable to the results of alternative treatment modalities such as Fogarty
balloon thromboembolectomy or local fibrinolysis.
PMID- 10674459
TI - Safety and efficacy of Omniscan (gadodiamide injection) at 0.1 mmol/kg for MRI in
infants younger than 6 months of age: phase III open multicenter study.
AB - RATIONALE AND OBJECTIVES: To demonstrate that gadodiamide injection is a safe and
efficient contrast agent for MRI in infants younger than 6 months of age.
METHODS: The authors designed a phase III multicenter nonrandomized study using a
control group. Gadodiamide injection at a dosage of 0.1 mmol/kg body weight was
administered to 39 children; 20 received no contrast. The mean age was 10.6 weeks
in the contrast group and 9.3 weeks in the control group. MR examinations, blood
(serum creatinine, S-ASAT, S-ALAT, S-bilirubin, alkaline phosphatase) and urine
(proteins, blood, others) sampling before sedation and after examination, heart
rate (electrocardiography) and oxygen saturation (pulse oximetry) during
examination, adverse events, and efficacy parameters were analyzed. RESULTS: In
the contrast group, 18 (51.4%) children had 31 abnormal changes in one or more of
the safety parameters and vital signs. In the control group there were 16 (80.0%)
children with 19 abnormal changes. Gadodiamide injection had no negative
influence on the safety parameters. No serious adverse events occurred, and only
three clinically relevant adverse events (elevation of S-ALAT and S-ASAT,
elevation of bilirubin) in two patients in the contrast group and one event
(vomiting) in one patient in the control group were documented. The benefit of
the contrast medium was clearly shown for all evaluated parameters. CONCLUSIONS:
Gadodiamide injection is safe, well tolerated, and effective in infants younger
than 6 months of age.
PMID- 10674460
TI - Noise affects auditory and linguistic processing differently: an MEG study.
AB - We investigated the influence of noise on brain responses to spoken sentences in
MEG. Sixteen subjects had to listen to acoustically presented sentences and judge
their syntactic correctness. Sentences were either presented on a silent
background or with noise. Noise had differential effects on early auditory and
syntactic processes. While noise affected early auditory processes only in the
right hemisphere, noise had a general effect on syntactical processes. The evoked
responses to syntactic violations compared with correct sentences, namely an
early left anterior negativity, were significantly suppressed when noise was
present The noise suppression effect, however, was not lateralized.
PMID- 10674461
TI - Inhibition of TNF-alpha can attenuate or exacerbate excitotoxic injury in
neonatal rat brain.
AB - Tumor necrosis factor (TNF)-alpha, a multifunctional pro-inflammatory cytokine,
has been implicated in the pathogenesis of acute ischemic brain injury. Recent
data also suggest that TNF-alpha is a clinically relevant mediator of neonatal
brain injury. We hypothesized that inhibition of TNF-alpha activity would reduce
excitotoxic brain injury in neonatal rats. To test this hypothesis, we evaluated
the efficacy of a TNF binding protein (bp) in attenuating NMDA-induced injury in
7 day old rats. Intrastriatal co-injection of TNFbp (3.75 microg) with NMDA (10
nmol) reduced striatal injury by 26%; in contrast, intra-hippocampal co-injection
of TNFbp (3.75 microg) with NMDA (10 nmol) increased hippocampal damage by 68%.
These findings indicate that TNF-alpha may have both beneficial and deleterious
effects in the injured neonatal brain.
PMID- 10674462
TI - Alexia for Braille following bilateral occipital stroke in an early blind woman.
AB - Recent functional imaging and neurophysiologic studies indicate that the
occipital cortex may play a role in Braille reading in congenitally and early
blind subjects. We report on a woman blind from birth who sustained bilateral
occipital damage following an ischemic stroke. Prior to the stroke, the patient
was a proficient Braille reader. Following the stroke, she was no longer able to
read Braille yet her somatosensory perception appeared otherwise to be unchanged.
This case supports the emerging evidence for the recruitment of striate and
prestriate cortex for Braille reading in early blind subjects.
PMID- 10674463
TI - Hierarchical visual processing is dependent on the oculomotor system.
AB - Using functional MRI and eye movement recordings we studied the processing of
hierarchical stimuli. In agreement with others, we found a minor left hemispheric
dominance during local and right dominance during global processing. When
attention was directed locally, well-known oculomotor cortical areas were
activated, and saccades were elicited in 41% of the trials. Their latencies were
similar to pro-saccades. During global processing virtually no saccades occurred.
These results suggest two different operational modes of attention. Attending to
local features induces a shift of attention, which simultaneously computes a
saccade on any level above the brainstem with a computational burden equal to
reflexive saccades. Conversely, attending to global features induces an expansion
of the focus of attention, which reinforces fixation.
PMID- 10674464
TI - Quinolinic acid inhibits glutamate uptake into synaptic vesicles from rat brain.
AB - Quinolinic acid (QA) is an endogenous and potent neurotoxin associated with the
neurotoxicity of various common diseases. The uptake of neurotransmitters into
synaptic vesicles is an important event involved in the storage and release of
neurotransmitters by vesicles. The influence of QA on the uptake of glutamate,
GABA and glycine into rat brain synaptic vesicles was investigated. QA (0.3-10
mM) significantly inhibited (>50%) the uptake of glutamate into synaptic
vesicles, whereas QA at concentrations up to 10 mM had no significant effect on
GABA or glycine uptake. Such results indicate that QA is able to selectively
inhibit the vesicular uptake of glutamate, without interfering with the uptake of
the inhibitory neurotransmitters GABA and glycine. These findings might be
related to the neurotoxic effects of QA in the brain.
PMID- 10674465
TI - Melatonin synthesis: arylalkylamine N-acetyltransferases in trout retina and
pineal organ are different.
AB - Serotonin N-acetyltransferase (AANAT) is the first enzyme in the conversion of
serotonin to melatonin. Changes in AANAT activity determine the daily rhythm in
melatonin secretion. Two AANAT genes have been identified in the pike, pAANAT-1
and pAANAT-2, expressed in the retina and in the pineal, respectively. The genes
preferentially expressed in these tissues encode proteins with distinctly
different kinetic characteristics. Like the pike, trout retina primarily
expresses the AANAT-1 gene and trout pineal primarily expresses the AANAT-2 gene.
Here we show that the kinetic characteristics of AANAT in these tissues differ as
in pike. These differences include optimal temperature for activity (pineal: 12
degrees C; retina: 25 degrees C) and relative affinity for indoleethylamines
compared to phenylethylamines. In addition, retinal AANAT exhibited substrate
inhibition, which was not seen with pineal AANAT. The kinetic differences between
AANAT-1 and AANAT-2 appear to be defining characteristics of these gene
subfamilies, and are not species specific.
PMID- 10674466
TI - Developmental dependency of Meissner corpuscles on trkB but not trkA or trkC.
AB - The distribution of S100-immunoreactive (ir) corpuscular endings was examined in
the palate of wildtype and knockout mice for trkA, trkB or trkC. In wildtype
mice, S100-ir corpuscular endings were abundant at the top of palatal rugae. The
endings contained 2-4 parallel arrays of S100-ir neurites. The distribution of
S100-ir nerve endings in trkA and trkC knockout mice was similar to that in
wildtype mice; S100-ir corpuscular endings were abundant in palates of the mutant
mice. In trkB knockout mice, the palate was devoid of corpuscular endings, An
immunoelectron microscopic method indicated that S100-ir corpuscular endings were
identical to Meissner corpuscles. The normal development of Meissner corpuscles
is probably dependent on trkB but not trkA or trkC.
PMID- 10674467
TI - Ipsilateral and contralateral transfer of tactile learning.
AB - We examined the spatial organization of perceptual learning in a cortex-dependent
task. Rats learned a tactile task using four whiskers on one side of the snout,
all others being clipped. These trained whiskers were then clipped and prosthetic
whiskers were attached. Subsequent performance was found to be determined by the
location of the prosthetic whiskers. There was partial transfer of learning to
neighbouring whisker positions. In addition, there was partial transfer of
learning to whisker positions on the other side of the snout, but only if the
prosthetic whiskers were symmetrically opposite the trained whiskers. These
findings suggest that neural changes underlying perceptual learning are
distributed according to the topographic organization of the sensory cortical
map.
PMID- 10674468
TI - Subthalamic nucleus microinjections of 5-HT2 receptor antagonists suppress
stereotypy in rats.
AB - The subthalamic nucleus (STN) is an important mediator of basal ganglia output.
We studied the effects of STN microinjections of the serotonin-2 (5-HT2)
antagonists clozapine, mesulergine and M100,907 on apomorphine-induced
stereotypic activity in the rat. Each compound profoundly decreased the
expression of stereotypic behavior, with particularly strong effects to reduce
gnawing behavior. Because M100,907 does not have appreciable affinity for
dopamine D1 and D2 receptors, and since all three agents are 5-HT2 antagonists,
the current data suggest that basal ganglia output related to orofacial movements
can be significantly modified by 5-HT2 receptors. The results suggest that
antipsychotics with serotonergic properties may have direct actions on the STN
that influence their potential to produce orofacial and other motor side effects.
PMID- 10674469
TI - Attentional suppression of activity in the human visual cortex.
AB - We have used fMRI to examine the nature of the changes that occur in the human
visual cortex when an observer attends to a particular location in the visual
image. Previous studies have shown that the magnitude of the response to a visual
stimulus is increased when the observer attends to the stimulus. We show that, in
addition, attention to a particular location results in a widespread suppression
of activity levels at all other locations. This suggests that a key mechanism of
attentional modulation may be that spontaneous (baseline) levels of neural
activity are adjusted in a position-dependent manner across the entire visual
field.
PMID- 10674470
TI - Serum immunoglobulins in brain tumours and lumbar disc diseases.
AB - Changes of serum immunoglobulin (Ig) concentrations may occur in both brain
tumours and lumbar disc diseases (LDD). The purpose of this study was to
investigate the changes of pre- and post-operative serum Ig levels in brain
tumours and LDDs. Serum IgG, IgA and IgM levels were measured in 127 patients
with brain tumour, 100 patients with LDD and 20 healthy subjects without
neurological disease. Increases in one or more of the pre-operative serum Ig
levels were observed in the patients with both brain tumours and LDDs compared
with controls. However pre-operative serum IgG level was highly increased in all
brain tumour types and LDDs (p<0.001). Serum IgA levels and IgM levels in the
post-operative stage were significantly decreased in patients with acoustic
neurinoma (p<0.01, p<0.001, respectively). Post-operative serum IgG, IgA and IgM
levels were significantly decreased (p<0.001) in patients with meningioma. Post
operative serum IgG and IgM levels were significantly decreased (p<0.001) in
patients with glioma. Patients with LDD showed a significantly decline in post
operative serum IgA and IgM levels (p<0.001). We think that decline in post
operative serum Ig levels may be of prognostic value in the patients with brain
tumours and LDDs.
PMID- 10674471
TI - Denervation and NKI receptor block modulate stimulated CGRP and PGE2 release from
rat skin.
AB - We investigated the possible neurogenic origin of prostaglandin E2 (PGE2) in the
rat skin, in vitro. The hairy skin of one hindpaw was denervated and one week
later the dorsal hindpaws were skinned to study the release of calcitonin gene
related peptide (CGRP) and PGE2 using the EIA technique. Stimulation with
bradykinin (BK) caused a significant release of CGRP (1.4-fold increase) and PGE2
(3-fold) which was massively augmented under neurokinin I (NKI) receptor
antagonist treatment (CGRP: 4-fold, PGE2: 5-fold). In denervated skin the BK
evoked CGRP release was lost whereas the PGE2 release was unchanged. Thus,
neither nerve endings nor neuropeptides contribute essentially to BK-induced PGE2
release in the skin. However, excessive neuropeptide levels, as under NKI
blockade facilitate PGE2 formation, which may play a role in sustained
inflammation.
PMID- 10674472
TI - Amyloid Abeta40 CSF concentrations correlate to frontal lobe atrophy in
frontotemporal dementia.
AB - We wanted to further study amyloid Abeta protein alterations in non-AD
neurodegenerative diseases. Cerebrospinal fluid concentrations of the amyloid
Abeta protein with 40 (Abeta40) and 42 (Abeta42) amino acid residues were
measured in eleven patients with frontotemporal dementia (FTD). Abeta40 and
Abeta42 concentrations were related to the degree of frontal lobe atrophy as
assessed with MRI volumetry. Abeta40 concentrations showed a statistically
significant linear correlation with degree of frontal lobe atrophy (r = -0.77,
p<0.02). Similar results have not been found in previous studies of CSF Abeta40
concentrations and atrophy in patients with AD which suggest that the role of
Abeta40 differs between the pathological processes of FTD and AD.
PMID- 10674473
TI - Contralateral treatment with xylocaine reduces nociceptive behaviour in
mononeuropathic rats.
AB - The aim of the present study was to establish whether contralateral treatment
with local anaesthetics reduces nociceptive behaviour in mononeuropathic rats.
Contralateral treatment with xylocaine on day 6 and 11 following sciatic nerve
ligation increased withdrawal latencies to thermal but not to mechanical
stimulation for 3-4 days. Rats who received contralateral treatment with
xylocaine on day 6 and 11 showed a reduced autotomy score during the following 6
weeks. To compare ipsilateral and contralateral effects another set of
experiments was performed. Rats treated contralaterally on day 11 had a
significantly lower autotomy score at week 4 and 6. Our results demonstrate that
contralateral treatment with xylocaine reduces nociceptive behaviour in
mononeuropathic rats for days or weeks.
PMID- 10674474
TI - The CCTTT polymorphism in the NOS2A gene is associated with dementia with Lewy
bodies.
AB - We report the analysis of the allele distribution of a (CCTTT)n pentanucleotide
repeat within the promoter region of the NOS2A gene in DNA samples from patients
with autopsy confirmed Alzheimer's disease (AD) and dementia with Lewy bodies
(DLB) type. A significant difference was observed in the allelic distribution
between the control group and the DLB group (chi2 = 15.175, df = 5; p<0.01), with
an increased occurrence of the eight and nine repeat alleles, and a marked under
representation of the 11 repeat allele. Genotype frequencies in the DLB group
also differed significantly from controls (p<0.012). These results suggest that
variations in the NOS2A gene may predispose to the development of DLB.
PMID- 10674475
TI - c-fos expression and redox state of cytochrome oxidase of rat brain in hypoxia.
AB - Hypoxic induction of c-fos was studied in rat brains as a function of the
cerebral oxygenation state using near-infrared spectroscopy by which the
hemoglobin oxygenation state and redox state of mitochondrial cytochrome oxidase
could be monitored noninvasively. Following reoxygenation after hypoxia, the
expression of c-fos and MAP2 mRNAs was followed by reverse transcription-coupled
PCR. The expression of MAP2 remained unchanged throughout all the conditions from
21 to 8% FiO2. Under mildly hypoxia conditions, c-fos mRNA was not induced.
Hemoglobin was partially deoxygenated but cytochrome oxidase remained fully
oxidized. Severe hypoxia, where cytochrome oxidase was reduced, caused a
significant induction of c-fos mRNA At this stage, the oxygen concentration in
cerebral tissue fell to < 10(-7) M. These data suggest that the decline in
oxidative phosphorylation might be a trigger for the induction of c-fos mRNA.
PMID- 10674476
TI - Analysis of splicing of four mouse JNK/SAPKalpha variants.
AB - The JNK/SAPK (c-Jun NH2-terminal kinase/stress-activated protein kinase) cascade
is activated by a variety of stress stimuli and by the inflammatory cytokines
interleukin-I (IL-I) and tumor necrosis factor alpha (TNFalpha). Four splice
variants of the mouse JNK/SAPKalpha isoform, which differ in a region located in
subdomains IX-X of the protein, were previously identified. Analysis of the
sequence of the central region of the mouse JNK/SAPKalpha gene indicates that
splice variants I and II are generated by a typical alternative splicing
mechanism, while splice variants III and IV are generated by a less common
mechanism, where alternative 3' splice sites located inside an exon (cryptic
sites) are selected. The major splice variants alphaI and all have a wide and
similar distribution in hippocampus, cerebral cortex, caudate-putamen, amygdala
and the granule cell layer of cerebellum, although their expression is
specifically regulated in certain cell types.
PMID- 10674477
TI - Quantitative PCR analysis of AMPA receptor composition in two paradigms of global
ischemia.
AB - Quantitative PCR was used to analyse the expression of GluR1, GluR2, GluR2 flip,
GluR2 flop and GluR3 mRNA in animals after ischemia and tolerance-inducing
ischemia. The ischemic animals showed a decrease in the GluRs to approximately
30%, except for GluR2-flip, which decreased to 75%. The tolerance animals
displayed regulation of GluR1 to 75%, GluR2 and GluR2-flop to 283% and 265%
respectively. We did not find a correlation between GluR2 regulation and cell
loss in the ischemic group. The selective upregulation of GluR2/GluR2 flop in
tolerant animals indicates a possible mechanism for enhanced AMPA receptor
desensitisation leading to tolerance to ischemia.
PMID- 10674478
TI - Ultradian rhythmic neuronal oscillation in the intergeniculate leaflet.
AB - Our paper is the first to describe ultradian rhythmic neuronal oscillation in the
intergeniculate leaflet (IGL) of the rat. We recorded a multiple-unit neuronal
activity (MUA) from dorsal to ventral parts of the lateral geniculate nucleus
(LGN) in anaesthetized rats. In all the subdivisions of the lateral geniculate
complex we observed spontaneous irregular firing rates of cells. However only at
the anatomical localisation of the IGL, after the light was on, those responses
exhibited burst firing with a constant interburst interval, which lasted several
hours until the light was off. The duration of that rhythmic oscillation obtained
by means of Fourier's analysis was approximately 124 s. To date we have not had
sufficient data to discuss possible mechanisms of this neuronal rhythmicity. We
can only conclude that light is the most important stimulus not only for
suprachiasmatic nuclei (SCN), but also for the IGL. On the other hand, we can
neither exclude nor confirm that in order to evoke ultradian rhythmical
oscillation in the IGL, in addition to light also non-photic information is
necessary.
PMID- 10674479
TI - Retention of words in long-term memory: a functional neuroanatomical study with
PET.
AB - We used PET to identify brain regions associated with retention of verbal
materials in long-term memory. During a PET scan, subjects repeated many sets of
words one after another. In a retention condition, they were simultaneously
required to retain 10 key words that were irrelevant to the repetition task.
Significant increases in regional cerebral blood flow during the retention
condition were found in bilateral parahippocampal regions, the left prefrontal
and parietal association cortices, the supplementary motor area, the neostriatum
and the cerebellum. We clearly demonstrated that retention of verbal materials
was accompanied by neural activities in the medial temporal lobes. We also showed
that, in the early phase, retention of words in long-term memory recruited left
cortical areas surrounding those relevant to verbal short-term memory.
PMID- 10674480
TI - Lateralization of movement-related potentials and the size of corpus callosum.
AB - Using structural MRI and whole-head EEG recordings, we analyzed the correlations
between the anatomical parameters of the corpus callosum and the hemispheric
distribution of the cortical movement-related potentials during right finger and
shoulder movements in nine right-handed men. Statistically significant
correlation was found only in finger movements. A relatively large genu and the
anterior part of the truncus of the corpus callosum correlated with enhanced pre
movement EEG potential over the ipsilateral M1/S1 area. The lateralization of the
movement-related potentials correlates with the size of those callosal regions
which connect the homologous areas of the primary sensorimotor and frontal
cortices.
PMID- 10674481
TI - ERP development in the rat in the course of learning two-tone discrimination
task.
AB - To clarify some neurophysiological aspects of learning, we investigated the
relationship between the course of learning and development of ERP and
investigated developmental processes of ERPs. Nine male Sprague-Dawley rats were
trained for a two-tone discrimination task and rat P3 and N1 component were
longitudinally recorded. Both rat P3 and N1 gradually increased with learning
only for target tones. An improvement in the proportion of correct responses
preceded the increase in ERPs, and the increase in P3 and N1 proceeded almost
simultaneously. These findings suggest that multiple kinds of information
processing were acquired with learning the two-tone discrimination task. ERP
development could be utilized as an index of establishment of learning.
PMID- 10674482
TI - The selectivity of the occipitotemporal M170 for faces.
AB - Evidence from fMRI, ERPs and intracranial recordings suggests the existence of
face-specific mechanisms in the primate occipitotemporal cortex. The present
study used a 64-channel MEG system to monitor neural activity while normal
subjects viewed a sequence of grayscale photographs of a variety of unfamiliar
faces and non-face stimuli. In 14 of 15 subjects, face stimuli evoked a larger
response than non-face stimuli at a latency of 160 ms after stimulus onset at
bilateral occipitotemporal sensors. Inverted face stimuli elicited responses that
were no different in amplitude but 13 ms later in latency than upright faces. The
profile of this M170 response across stimulus conditions is largely consistent
with prior results using scalp and subdural ERPs.
PMID- 10674483
TI - Ovarian steroids and raloxifene prevent MPTP-induced dopamine depletion in mice.
AB - The activity of steroids was studied in 1-methyl-phenyl-1,2,3,6
tetrahydropyridine (MPTP) lesioned retired breeder C57BL/6 male mice as a model
of Parkinson's disease. Steroids were injected daily for 5 days before MPTP (4
injections, 15 mg/kg i.p., at 2 h intervals) and hormonal treatment continued for
5 more days. Mice that received 17beta-estradiol or progesterone or raloxifene (a
selective estrogen receptor modulator) and MPTP had striatal concentrations of
dopamine (DA) and its metabolites dihydroxyphenylacetic acid (DOPAC) and
homovanillic acid (HVA) similar to those in control animals, whereas mice that
received MPTP alone or with 17alpha-estradiol (the isomer with weak estrogenic
activity) had an extensive decrease of DA and its metabolites. These results
suggest stereospecific prevention of MPTP-induced dopamine loss by 17beta
estradiol, which is also observed with progesterone and raloxifene.
PMID- 10674484
TI - Preserved olfactory short-term memory after combined cholinergic and serotonergic
lesions using 192 IgG-saporin and 5,7-dihydroxytryptamine in rats.
AB - Young adult Long-Evans female rats were subjected to intracerebroventricular
injections of 150 microg 5,7-dihydroxytryptamine (5,7-DHT), 2 microg 192 IgG
saporin, or a combination of both neurotoxins. All rats were tested for olfactory
recognition (short-term memory) using a task based on spontaneous exploration of
odor sources. Compared with animals undergoing sham operations, 5,7-DHT reduced
the concentration of serotonin by 60-80% in the frontoparietal cortex,
hippocampus, striatum and the olfactory bulbs. After 192 IgG-saporin treatment,
acetylcholine concentrations were reduced by approximately 40% in all these
structures, except the striatum. Neither lesion induced a significant deficit in
olfactory recognition. These data suggest that combined lesions of cholinergic
and serotonergic neurons in the rat brain do not alter olfactory perception or
olfactory short-term memory.
PMID- 10674485
TI - Reversible lesions of the rhinal cortex produce delayed non-matching-to-sample
deficits in rats.
AB - Rats with cannulae guides implanted in the rhinal cortex were tested on a delayed
non-matching-to-sample task, following either lidocaine or sham microinfusions.
Bilateral lidocaine microinfusions to the rhinal cortex produced significant
delayed non-matching-to-sample deficits. These results are consistent with the
putative role of the rhinal cortex in object recognition but because the deficits
were not shown to be time dependent, non-mnemonic interpretations cannot be ruled
out. These results also illustrate the utility of reversible lidocaine lesions in
the study of the neuroanatomical basis of delayed non-matching-to-sample.
PMID- 10674486
TI - Acute treatment of hypertension increases infarct sizes in spontaneously
hypertensive rats.
AB - We studied the effect of dihydralazine treatment of hypertension in spontaneously
hypertensive stroke-prone rats in a model of permanent focal cerebral ischemia
(stroke). After occlusion of the middle cerebral artery systemic arterial
pressure (SAP) was lowered with a computer controlled infusion device from 163 to
135 or 117 mm Hg for 24h. In the control group SAP was not manipulated. Reduction
of SAP to normotension (117 mm Hg) significantly worsened outcome and increased
infarct volume measured 7 days after induction of ischemia, whereas a mild
reduction of SAP (to 137 mm Hg) had no statistically significant effect on
outcome or infarct volume. We conclude that pharmacological treatment of
hypertension may negatively affect neurological outcome and infarct volume in a
rat stroke model.
PMID- 10674487
TI - AlphaB-crystallin regulates intermediate filament organization in situ.
AB - AlphaB-crystallin is a small heat shock protein (hsp) and molecular chaperone
that can interact with a wide spectrum of cellular components including
intermediate filaments (IF). The significance of these interactions is not
currently known. We have tested whether increased alphaB-crystallin expression
effects changes in the IF systems in situ. Adenoviral-mediated gene transfer was
used to overexpress alphaB-crystallin in primary astrocytes. A positive
correlation was observed between overexpression of alphaB-crystallin and diffuse,
filigree IF. AlphaB-crystallin did not appear to alter the polymerization state
of IF proteins. These data show that an increase in alphaB-crystallin expression
in the absence of stress can modify the organizational state of IF and that
alphaB-crystallin can function as an IF debundling protein.
PMID- 10674488
TI - Auditory responses from the frontal cortex in the mustached bat, Pteronotus
parnellii.
AB - Response properties of neurons in an auditory field in the frontal cortex of the
mustached bat, Pteronotus parnellii, have not been studied before. We recorded
neural responses to constant frequency (CF) stimuli from the frontal auditory
field in awake animals. The majority (75%) of neurons in this area responded well
and often exhibited low thresholds to CF stimuli. Most CF-responsive neurons
exhibited sharp tuning with values of > 180 for Q10db, a quality factor
expressing the sharpness of tuning at 10dB above threshold. Neurons at 13
recording sites exhibited combination sensitivity in that their responses were
facilitated by presenting combinations of either CF1/CF2 and/or CF1/CF3
components of the mustached bat's echolocation signal. Unlike the typical on
responses to a 30 ms tone, observed in the mustached bat's auditory cortex and at
subcortical levels, many frontal auditory neurons exhibited loosely time locked
firing patterns that lasted for > 100 ms.
PMID- 10674489
TI - The 68K protease has beta-secretase-like activity for lymphocyte precursor
protein but not for brain substrate.
AB - Processing and metabolism of beta-amyloid precursor protein (APP) and generation
of a variety of beta-amyloid (Abeta) peptides in the human brain is essentially
associated with pathophysiology of Alzheimer's disease (AD). APP degradation
activity of the 68 kDa serine protease, which was originally prepared from
familial AD lymphoblastoid cells and harbors beta-secretase-like activity, was
analyzed by Western blot using anti Abeta 1/40 antibody and anti APP cytoplasmic
domain (CT) antibody. Native lymphocyte APP (LAPP) prepared from normal or AD
derived lymphoblastoid cells was degraded by the protease, generating a 16 kDa
Abeta-bearing C-terminal fragment of APP. N-terminal amino acid sequencing of the
fragment indicated that the protease cleaves LAPP at the Abeta-N-terminus. When
the LAPP was treated with chondroitinase ABC prior to proteolysis, the activity
to generate the fragment was inhibited, but pretreatment with heparitinase
resulted in no effect. Native hippocampal APP prepared from normal brain,
however, did not generate the 16 kDa peptide by the protease treatment. These
results suggest that the process of APP degradation and Abeta-peptides
generation, including beta-secretase activity, is associated with tissue
specificity of both APP substrate and proteases. They also indicate that sulfated
glycoconjugates attached to a portion of APP isoforms may play a role as a
molecular determinant in the proteolysis.
PMID- 10674490
TI - Brainstem microstimulation activates sympathetic fibers in pudendal nerve motor
branch.
AB - A bilateral spino-bulbo-spinal circuit conveys information from/to the male
urogenital tract and perineal muscles. This is the first electrophysiological
report of another descending pathway, one which conveys output from the medullary
reticular formation (MRF) to activate postganglionic sympathetic fibers contained
within the motor branch of the pudendal nerve (PudM). In anesthetized rats, long
latency (> 150 ms) discharges were elicited in the PudM following ipsilateral or
contralateral microstimulation of the MRF. These firing bursts were not observed
in rats after sectioning the lower lumbar sympathetic trunk. The most robust
activation was observed when neurons in or near the lateral paragigantocellular
reticular nucleus were microstimulated bilaterally. Urogenital dysfunction that
occurs following severe spinal cord injury probably results from disrupting these
and other supraspinal circuits.
PMID- 10674491
TI - Hyperinsulinemia increases norepinephrine metabolism in the ventromedial
hypothalamus of rats.
AB - Numerous studies have implicated increased ventromedial hypothalamic (VMH)
norepinephrine (NE) activity as a contributing factor to the obese,
hyperinsulinemic, glucose intolerant condition. However, factors contributing to
the increased VMH NE activity remain unknown. This study therefore investigated
in normal rats the effect of a hyperinsulinemic-euglycemic clamp on VMH monoamine
turnover and utilization via simultaneous VMH microdialysis to establish a role
for hyperinsulinemia in the stimulation of VMH NE activity. Within 20 min of
initiation of the hyperinsulinemic-euglycemic clamp, VMH extracellular
methoxyhydroxy phenylglycol (metabolite of NE) level increased by 54% and
remained approximately at this level for the 100 min duration of the clamp
relative to control values (p<0.05). Hyperinsulinemia did not affect VMH dopamine
or serotonin metabolism. Subsequent establishment of a hyperinsulinemic
hypoglycemic camp did not alter the VMH monoamine metabolism profile relative to
the hyperinsulinemic-euglycemic clamp. Infusion of saline (as control) in a
separate group of rats over the entire clamp period induced no changes in any
monoamine metabolic profile relative to baseline. Hyperinsulinemia can feedback
to stimulate VMH NE activity and, as a result, may contribute to the initiation
and/or perpetuation of the obese, hyperinsulinemic, glucose-intolerant state.
PMID- 10674492
TI - Effects of retinoic acid and tumor necrosis factor alpha on GL-15 glioblastoma
cells.
AB - Glioblastomas are particularly resistant to classical antitumor treatments.
Retinoids, which proved effective in the treatment of promyelocytic leukemia,
have been used for clinical assays on glioma tumors with only moderate effects;
however in some cases they were active in combination with another therapy. These
observations prompted us to analyse the efficacy of combining retinoic acid (RA)
with a cytokine on a clonal human glioma cell line. On GL-15 cells, RA and tumor
necrosis factor alpha (TNFalpha) both reduced the glial fibrillary acidic protein
level and DNA synthesis and induced apoptotic pathways, but they were
significantly more effective when used together. The up-regulation of the p55 TNF
receptors observed during RA exposure might explain this cooperative effect.
PMID- 10674493
TI - Kainate receptors activate NF-kappaB via MAP kinase in striatal neurones.
AB - The transcription factor NF-kappaB has been implicated in the synaptic plasticity
and neurotoxicity mediated by ionotropic glutamate receptors in the striatum.
However, the class of glutamate receptor and the intracellular pathways involved
have not been determined. Kainate, but not AMPA or NMDA, was found to activate NF
kappaB in superfused slices of rat striatum. A similar activation was produced by
the calcium ionophore A23187. The NF-kappaB activation by kainate was not
observed in the absence of extracellular calcium, and was blocked by the p44/p42
MAP kinase inhibitor PD98059, but not by the p38 MAP kinase inhibitor SB203580.
This demonstrates that striatal kainate receptors are coupled to NF-kappaB
activation via calcium influx and p44/p42 MAP kinase activation.
PMID- 10674494
TI - Sensory-specific satiety-related olfactory activation of the human orbitofrontal
cortex.
AB - When a food is eaten to satiety, its reward value decreases. This decrease is
usually greater for the food eaten to satiety than for other foods, an effect
termed sensory-specific satiety. In an fMRI investigation it was shown that for a
region of the orbitofrontal cortex the activation produced by the odour of the
food eaten to satiety decreased, whereas there was no similar decrease for the
odour of a food not eaten in the meal. This effect was shown both by a voxel-wise
SPM contrast (p<0.05 corrected) and an ANOVA performed on the mean percentage
change in BOLD signal in the identified clusters of voxels (p<0.006). These
results show that activation of a region of the human orbitofrontal cortex is
related to olfactory sensory-specific satiety.
PMID- 10674495
TI - Presenilin I expression in yeast lowers secretion of the amyloid precursor
protein.
AB - Presenilin (PS) mutations are associated with early-onset Alzheimer's disease and
PS proteins are involved with gamma-secretase cleavage of the amyloid precursor
protein, APP. We have shown previously that alpha-, beta- and gamma-secretase
cleavages of APP are conserved in Pichia pastoris. Here, we report co-expression
of APP and PSI in P. pastoris and show by immunoelectron microscopy
colocalization of these two proteins in expanded endoplasmic reticulum. Western
blot analysis indicates a drastic reduction of both alpha- and beta-secretase
products. A relative increase in beta-secretase product derived from immature APP
is also observed, pointing to a beta-secretase activity of P. pastoris associated
with the early secretory pathway.
PMID- 10674496
TI - TNF-alpha induced over-expression of GFAP is associated with MAPKs.
AB - Increased levels of tumor necrosis factor-alpha (TNF-alpha), a pluripotent
cytokine that is reportedly mitogenic to astrocytes, are associated with the
expression of glial fibrillary acidic protein (GFAP), the most specific marker
for astrocytes, in many neuropathological conditions, including brain injury, CNS
infection, Creutzfeldt-Jakob disease and Alzheimer's disease. Here, we show that
treatment of cultured astrocytes with TNF-alpha resulted in dramatic over
expression of GFAP, associated with a substantial activation of the mitogen
activated protein kinase (MAPK) Erk2 (extracellular signal-regulated protein
kinase). We also demonstrate that TNF-alpha-induced over-expression of GFAP was
significantly attenuated by the MAPK inhibitor PD98059. We conclude that TNF
alpha may upregulate GFAP through the MAPK signaling pathway. Because increased
GFAP is a hallmark of reactive gliosis, understanding the mechanisms that
regulate GFAP expression may facilitate development of strategies to minimize the
gliosis associated with many brain diseases.
PMID- 10674497
TI - Effects of 902 MHz electromagnetic field emitted by cellular telephones on
response times in humans.
AB - The present study examined possible influences of a 902 MHz electromagnetic field
emitted by cellular telephones on cognitive functioning in 48 healthy humans. A
battery of 12 reaction time tasks was performed twice by each participant in a
counterbalanced order: once with and once without the exposure to the field. The
results showed that the exposure to the electromagnetic field speeded up response
times in simple reaction time and vigilance tasks and that the cognitive time
needed in a mental arithmetics task was decreased. The results suggest that
exposure to the electromagnetic field emitted by cellular telephones may have a
facilitatory effect on brain functioning, especially in tasks requiring attention
and manipulation of information in working memory.
PMID- 10674498
TI - Calcium channels functional roles in the frog semicircular canal.
AB - Different types of voltage-operated calcium channels have been described in hair
cells; however, no clear functional role has been assigned to them. As a first
functional characterization of vestibular calcium channels, we studied the effect
of several calcium channel agonists and antagonists on whole nerve firing rate in
an isolated frog semicircular canal preparation. Resting activity was affected by
all dihydropyridines tested and by omegaconotoxin GVIA, whereas only nimodipine
was able to reduce the mechanically evoked activity. These results indicate that
nimodipine-sensitive channels play a major role in afferent transmitter release,
and omega-conotoxin GVIA sensitive channels regulate the afferent firing
(possibly on the postsynaptic side) but with a less important role.
PMID- 10674499
TI - Auditory responses from the frontal cortex in the short-tailed fruit bat Carollia
perspicillata.
AB - Based on neuroanatomical findings it was hypothesized that an area in the bat
frontal cortex is part of a sensorimotor feedback loop and probably important to
goal-directed behaviors guided by auditory information. The present report
describes the basic stimulus preferences and response properties of neurons from
this area in the short-tailed fruit bat Carollia perspicillata. Responses to
acoustic stimuli mimicking biosonar pulse-echo (i.e. FM-FM) combinations were
found to be facilitated throughout but only rarely exhibited tuning to pulse-echo
delay. As opposed to the often sharply delay-tuned FM-FM neurons in the species'
auditory cortex, frontal cortical FM-FM neurons seem to be suited for indicating
the presence of an insonified object irrespective of its distance and hence are
likely to function as novelty detectors and to trigger changes in the bats'
orientation behavior.
PMID- 10674500
TI - Neuroprotection achieved with a novel proteasome inhibitor which blocks NF-kappaB
activation.
AB - Activated NF-kappaB contributes to cerebral infarction by triggering a neuro
inflammatory response. Rats subjected to 90min middle cerebral artery occlusion
developed a cortical infarct of 20+/-4% of hemispheric volume (n = 8). Treatment
with the proteasome inhibitor CVT-634 resulted in a significantly smaller infarct
of 13+/-2% (n = 7, p<0.01) and 12+/-2% (n = 8, p<0.001) of hemispheric volume at
1 day and 7 days, respectively. Since regional cerebral blood flows for the core
and penumbral regions were not affected, we concluded that all animals received
the same ischemic insult The reduction in infarction persisted for 7 days. This
is the first indication that a proteasome inhibitor can reduce infarct volume in
a focal model of cerebral ischemia.
PMID- 10674501
TI - Anesthesia human resources in Canada.
PMID- 10674502
TI - Litigation in Canada against anesthesiologists practicing regional anesthesia. A
review of closed claims.
AB - PURPOSE: To review the pattern of malpractice litigation related to regional
anesthesia in Canada. SOURCE: The Canadian Medical Protective Association (CMPA)
provided with information about all anesthesia claims that closed in the years
1990-1997. PRINCIPAL FINDINGS: In the period 1990-97 there were 7,909 closed
legal actions involving all CMPA members (56,000). Of these, there were 310 cases
involving anesthesiologists, of which 61 cases (approximately 20%) were related
to regional anesthesia. Forty-two involved neuraxial blocks, and the legal
outcome was favourable (dismissed or judgement in favour of the defendant doctor)
in 37 claims. Nineteen claims involved peripheral nerve blocks. All these had
favourable legal outcomes. Overall, 10% of regional anesthesia claims have
unfavourable outcomes, compared with 28% of all anesthesia related claims and 30%
of all CMPA members' claims. The degree of disability in the regional anesthesia
claims were: none 10%; minor 49%; major 36%; catastrophic 5%. There were no
deaths in the malpractice claims involving regional anesthesia, compared with 17%
in the all anesthesia group and 11% in all members' claims. CONCLUSION: Twenty
percent of all anesthesia claims in Canada are related to regional anesthesia.
The legal outcome of these claims is favourable in 90%. Unfavourable clinical
outcome is associated with catastrophic or major injury. There were no deaths in
the regional anesthesia claims.
PMID- 10674503
TI - A comparison of patient-controlled analgesia fentanyl and alfentanil for labour
analgesia.
AB - PURPOSE: To determine the analgesic efficacy of equipotent doses of PCA (patient
controlled analgesia) fentanyl and PCA alfentanil for labour pain. METHODS:
Twenty three, ASA I - II parturients between 32-42 wk gestational age in whom
epidural analgesia was contraindicated were randomized to receive PCA fentanyl
(Group F)or alfentanil (Group A). Plain numbered vials contained 21 ml fentanyl
50 microg x ml(-1) or alfentanil 500 microg x ml(-1). A one millilitre loading
dose was administered. The PCA solution was prepared by diluting 10 ml study drug
with 40 ml saline and the PCA pump was programmed to deliver a dose of 2 ml,
delay of five minutes and a basal rate of 2 ml x hr(-1). Maternal measurements
obtained were hourly drug dose, total dose, Visual Analog Pain Score (VAPS) q 30
min, sedation score q 1 hr and side effects. Neonates were assessed by 1,5, and
10-min Apgar scores, umbilical venous and arterial blood gases and
neurobehavioural scores at four and 24 hr. RESULTS: Mean VAPS from 7 - 10 cm
cervical dilatation were higher in Group A than in Group F (85.7+/-13.9 vs.
64.6+/-12.1; P<0.01) There were no inter-group differences in VAPS from 1-3 cm,
or from 4-6 cm dilatation, in maternal sedation scores or side effects, or in
neonatal outcomes. CONCLUSION: In the doses prescribed in this study, PCA
fentanyl was found to provide more effective analgesia in late first stage labour
than PCA alfentanil.
PMID- 10674504
TI - Plasma concentration of flumazenil following intranasal administration in
children.
AB - PURPOSE: A pharmacokinetic study in children to determine plasma flumazenil
concentrations after the intranasal administration of 40 microg x kg(-1).
METHODS: Following institutional approval and informed written consent, 11 ASA
physical status I-II patients, aged two to six years, undergoing general
anesthesia for dental surgery were recruited. After induction, 40 microg x kg(-1)
flumazenil Anexate, Roche, 0.1 mg x mL(-1) (0.4 mL x kg(-1))) were administered
via a syringe as drops, prior to nasal intubation. Venous plasma samples were
drawn prior to administration of flumazenil (t = 0), and then at 2, 4, 6, 8, 10,
15, 20, 30, 40, 60, and 120 min thereafter. The plasma samples were immediately
processed by the on-site laboratory and then stored at -70 degrees C, before
batch analysis via high performance liquid chromatography assay. Pharmacokinetic
data calculations were performed using WinNonLin software (Scientific Consulting
Inc.). RESULTS: Eleven patients were studied, but data for one patient were
discarded due to insufficient sampling. The median age was 4.3 yr (range 3 to 6),
with a median weight of 18.9 kg (range 14.9 to 22.2). There were seven boys and
three girls. Mean Cmax was 67.8 ng x mL(-1) (SD 41.9), with Tmax at two minutes.
The calculated half-life was 122 min (SD 99). CONCLUSION: The mean plasma
concentrations of flumazenil attained were similar to those reported after
intravenous administration, and may be sufficient to antagonize the side-effects
of benzodiazepines. This route of administration may be useful when the
intravenous route is not readily available.
PMID- 10674505
TI - Rate of change of cerebral blood flow velocity with hyperventilation during
anesthesia in humans.
AB - PURPOSE: Although it has been suggested that the rate at which the cerebral
circulation responds to changes in PaCO2 is different with differing anesthetics,
there have been no attempts to measure this. Transcranial Doppler allows the
continuous measurement of cerebral blood flow velocity (CBFV) and any changes
over time. Our aim was to compare the rate of change of CBFV when end-tidal CO2
(P(ET)CO2) was rapidly altered during halothane or isoflurane anesthesia.
METHODS: Twenty-eight unpremedicated healthy patients were randomly assigned to
receive air/O2 and either 1-1.5 MAC halothane or isoflurane as the primary
anesthetic. After 15 min of steady state, P(ET)CO2 was rapidly reduced from 45 mm
Hg to 30 mm Hg. CBFV and P(ET)CO2 were recorded every 30 sec for the next 10 min.
RESULTS: The rate of change of normalized CBFV (delta CBFV vs. delta time) was
more rapid in the isoflurane group (P <0.0001) especially in the initial few
minutes. In all patients anesthetized with isoflurane, and in all but two
patients anesthetized with halothane, the reduction in P(ET)CO2 produced a
corresponding decrease in CBFV However, there were no differences in the
magnitude of cerebrovascular CO2 reactivity (delta CBFV vs. delta P(ET)CO2)
between the two groups. CONCLUSIONS: The rate of change of CBFV was faster in the
isoflurane than in the halothane group especially in the initial few minutes.
Indeed, for two patients in the halothane group Vmca did not change despite a
change in P(ET)CO2. This may be of clinical importance when cerebrovascular tone
needs to be changed rapidly.
PMID- 10674506
TI - Cerebral oxygenation is better during mild hypothermic than normothermic
cardiopulmonary bypass.
AB - PURPOSE: Normothermic cardiopulmonary bypass (CPB) has been recently used in
cardiac surgery. However, there is a controversy whether there is a difference in
incidence of neurological disorder after coronary artery bypass graft (CABG)
surgery between normothermic CPB and mild hypothermic CPB. In this study, we
assessed the effects of normothermia and mild hypothermia (32 degrees C) during
CPB on jugular oxygen saturation (SjvO2). METHODS: Twenty patients scheduled for
elective CABG surgery were divided into two groups. Group 1 (n = 10) underwent
normothermic (>35 degrees C) CPB, and Group 2 (n = 10) underwent mild hypothermic
(32 degrees C) CPB. Alpha-stat blood gas regulation was applied. After inducing
anesthesia, a 4.0 French fibre optic oximetry oxygen saturation catheter was
inserted into the right jugular bulb to monitor SjvO2 continuously throughout
anesthesia and surgery. RESULTS: The SjvO2 in the normothermic group was
decreased at 20 (41.5+/-2.4%) and 40 min (43.8+/-2.8%) after the onset of CPB
compared with control (53.9+/-5.4%, P<0.05). However, there was no change in
SjvO2 in the mild hypothermic group during the study. No changes in jugular
venous-arterial differences of lactate or creatine phosphokinase isoenzyme BB
were observed in two groups during the study. CONCLUSIONS: Cerebral oxygenation,
as assessed by SjvO2 was increased during mild hypothermic CPB than during
normothermic CPB.
PMID- 10674507
TI - Comparison of differential blockade during spinal anesthesia using isobaric vs.
hyperbaric lidocaine 2%.
AB - PURPOSE: To compare the extent of the sensory, motor and sympathetic block
produced by a single dose of 60 mg lidocaine at the same concentration (2%) and
volume but at different baricity injected intraspinally. METHOD: In a randomised
double blind study, 40 ASA I-II patients were scheduled for elective surgery
(orthopedic, urologic, peripheral vascular and lower digestive procedure). They
were divided in two groups. Twenty patients received 60 mg lidocaine 2% in a
hyperbaric solution and 20 received 60 mg lidocaine 2% in a isobaric solution.
The levels of sensory (pinprick, ice) motor (Bromage scale) and sympathetic
blockade (galvanometry, cutaneous blood flow, temperature) were measured at 0, 5,
10, 15, 20 and 30 min. RESULTS: There were no differences between the groups with
regard to maximal height of sympathetic block, sensory level to pinprick: T5 +/
2.4 for isobaric group, T6 +/-3.6 for hyperbaric group or to cold: T3 +/-2.3 for
isobaric group, T4 +/-2.7 for hyperbaric group. Hyperbaric lidocaine 2% produced
a more pronounced sensory (pinprick, ice) and motor block on the dependant than
on the non-dependant side. CONCLUSION: The baricity of 60 mg lidocaine injected
intraspinally in the lateral decubitus position did not influence the cephalad
spread of sensory or sympathethic blockade. In the hyperbaric group, the
dependent side showed a more pronounced sensory (pinprick, ice), and motor block.
PMID- 10674508
TI - Neuromuscular effects of rapacuronium in pediatric patients during nitrous oxide
halothane anesthesia: comparison with mivacurium.
AB - PURPOSE: To describe neuromuscular effects of rapacuronium in pediatric patients
during N2O-halothane anesthesia and compare them with mivacurium in children.
METHODS: 103 pediatric patients, seven days -12 yr, received rapacuronium or
mivacurium during N2O-halothane anesthesia. Onset and recovery of block were
measured using EMG (Datex). Block was compared between groups based on drug
treatment and age. Children < two years received 1 or 2 mg x kg(-1) rapacuronium:
2-12 yr received either 2 mg x kg(-1) or 3 mg x kg(-1) rapacuronium, or 0.2 mg x
kg(-1) mivacurium. RESULTS: There were no differences in onset (1.7+/-1.8 min) or
maximum block (T1 2.4+/-8%) among neonates, infants, and toddlers after either
dose of rapacuronium. There was no difference between 1 and 2 mg x kg(-1) of
rapacuronium block at 60 sec. Train-of-four ratio (T4/T1) >0.7 occurred later
after 2 mg x kg(-1) than 1 mg x kg(-1) in these patients (P<0.05). There was no
difference in T25 among neonates, infants and toddlers for 1 mg x kg(-1) or 2 mg
x kg(-1) doses. Rapacuronium, 3 mg x kg(-1), produced maximum block 1.5 min
earlier than did mivacurium, 0.2 mg x kg(-1) (P<0.001). There was no difference
in block at 60 sec, maximum block or time to maximum block between 2 and 3 mg x
kg(-1) rapacuronium for children > two years of age. Maximum block occurred 1.0+/
0.5 min after 2 or 3 mg x kg(-1) when T1 was 0.2+/-1.1% of baseline. T25 and
T4/T1 >0.7 occurred 10 to 11 min later after this dose of rapacuronium than after
mivacurium. CONCLUSION: Rapacuronium produces block earlier than mivacurium.
Recovery from rapacuronium block is dose related and slower than that following
mivacurium during halothane anesthesia.
PMID- 10674509
TI - Accuracy of carboxyhemoglobin dilution method for the measurement of circulating
blood volume.
AB - PURPOSE: The management of circulating blood volume (BVc) is crucial in intensive
care unit (ICU) patients. The purpose of this study was to verify the accuracy
and precision of the carbon monoxide-labeled hemoglobin (CO-Hb) dilution method
(CO method) by comparing it with the 51Cr-labeled erythrocyte dilution method
(51Cr method) for the measurement of BVc. METHODS: A prospective study was
performed in 18 patients who underwent coronary artery bypass grafting (CABG)
under mild hypothermic cardiopulmonary bypass (CPB). The BVc was measured by both
the CO method and the 51Cr method at 24 hr after ICU admission in order to verify
the accuracy and precision of the CO method. Paired data were assessed in
absolute terms, and percentage errors were calculated by the degree of agreement.
RESULTS: Small mean differences and standard deviations between the CO method and
the 51Cr method (-70.2 +/-184.8 mL) and small percentage errors (-0.49+/-1.29%)
indicated the accuracy and precision of the CO method, and a close correlation
was observed (r = 0.97). CONCLUSION: The CO method can measure BVc with a similar
degree of accuracy as the 51Cr method. It is simple, repeatable and safe without
the risk of exposure to radioactivity in the ICU.
PMID- 10674510
TI - Epidural meperidine does not cause hemodynamic changes in the term parturient.
AB - PURPOSE: Meperidine has local anesthetic properties and, therefore, when given
epidurally it has the potential to cause hemodynamic changes. Our objective was
to study the hemodynamic effects of an analgesic dose of epidural meperidine (50
mg) in 34 ASA 1-2 term parturients scheduled for elective Cesarean section under
epidural anesthesia. METHODS: A lumbar epidural catheter was inserted and
patients lay in the supine left wedge position. Intravenous fluid preload was
withheld, and hemodynamic measurements comprising of mean arterial pressure,
cardiac output and heart rate were made using automatic oscillotonometry (Dinamap
1486SX) and transthoracic electrical bioimpedance (Bomed NCCOM3). Following
baseline measurements, the hemodynamic effects of sequential epidural injection
of first, 10 ml saline, and 20 min thereafter, 50 mg meperidine diluted to 10 ml
with saline, were recorded. Sensory blockade was assessed following each
injection using loss of temperature discrimination to ice. Paired Student t tests
were used to compare changes in hemodynamic variables. RESULTS: Epidural
meperidine produced a small increase from the saline values in the mean (SD)
cardiac output of 5.81 +/-1.44 to 6.04+/-1.54 L x min(-1) (P<0.05), and mean
arterial pressure of 77.1+/-8.8 to 79.3+/-9.9 mm Hg (P<0.05). Sensory changes,
the upper level of which ranged from L1 to T1, were detected in 94% of patients
given epidural meperidine. Epidural saline injection had no such hemodynamic
effects, but produced a detectable sensory level in two patients. CONCLUSION:
Epidural meperidine, 50 mg, caused minimal hemodynamic changes in term
parturients.
PMID- 10674511
TI - Familial hypokalemic periodic paralysis and Wolff-Parkinson-White syndrome in
pregnancy.
AB - PURPOSE: To describe the anesthetic and obstetrical management of a pregnant
patient with co-existing Familial Hypokalemic Periodic Paralysis (FHPP) and Wolff
Parkinson-White syndrome (WPW). CLINICAL FEATURES: A 29 yr-old primigravida with
FHPP and WPW presented to the antenatal clinic at 18 wk gestation, for
consideration of her anesthetic and obstetrical management during labour and
delivery. A plan was constructed to avoid the known precipitating factors of FHPP
including carbohydrate loading, cold, mental stress and exercise, which could
lead to acute attacks of weakness. She presented for induction of labour at 41 wk
and three days. An epidural catheter was sited early in labour. The second stage
was limited to less than one hour. She had a rotational forceps delivery for
which the epidural was extended to provide anesthesia. A healthy male baby was
delivered. The patient made an uncomplicated recovery and was discharged home on
the second postnatal day. The peripartum potassium was kept within the normal
range with intravenous as well as oral potassium supplementation. No arrhythmias
were reported. CONCLUSION: Assessment of the patient at an early stage in her
pregnancy allowed for a multidisciplinary approach to this patient and her
medical problems. A plan was made to avoid known precipitating factors during
labour, delivery and the postnatal period well in advance of her date of
confinement, leading to a successful outcome for mother and child.
PMID- 10674512
TI - Subcutaneous emphysema following trans-cricothyroid membrane injection of local
anesthetic.
AB - PURPOSE: To present a case of preoperative subcutaneous emphysema (SCE) as a
complication of trans-cricothyroid membrane (TCM) injection of lidocaine for
awake intubation. CLINICAL FEATURES: A 48-yr-old man with cervical myelopathy was
scheduled for elective cervical discectomy. Airway topical anesthesia consisted
of lidocaine pledgets and TCM injection. After successful awake fibreoptic
intubation was performed, SCE was noted in the neck region. The main differential
diagnosis of preoperative SCE included air leak via the anterior needle track
from TCM injection or disruption of mucosal membrane in the aerodigestive tract.
The latter was excluded by panendoscopy and an upper GI swallow study. The most
likely explanation for SCE was air leak from the anterior needle tract. The
subcutaneous emphysema resolved spontaneously without sequella. CONCLUSION:
Subcutaneous emphysema is a rare but potentially serious complication of TCM
injection of lidocaine. Anesthesiologists should be familiar with the
differential diagnosis, investigations and management of SCE.
PMID- 10674513
TI - Differential lung ventilation and emergency hyperbaric oxygenation for repair of
a tracheal tear.
AB - PURPOSE: To report the anaesthetic management of a case of tracheal rupture,
using different types of ventilation and additional hyperbaric oxygenation (HBO).
CLINICAL FEATURES: An 8 cm postintubation tracheal tear was repaired in a 66-yr
old woman with acute myocardial reinfarction, mediastinal and subcutaneous
emphysema, cardiac failure and unrecognized lymphoma. Intraoperative monitoring
included dual oximetry: arterial (SaO2) and mixed venous saturations (SvO2).
Maintenance of free surgical access and a series of life-threatening events like
dislocation of the jet catheter required many ventilation modes. An episode of
supraventricular tachycardia was interrupted by cardioversion. Differential lung
ventilation with a combination of conventional and high-frequency jet ventilation
(HFJV) modes preserved oxygenation (PO2 139.2 mm Hg, PCO2 42.4 mm Hg, FiO2 1.0)
until acute tube obstruction and decrease of saturation values (SaO2 58%, SvO2
45%) required emergency HBO: immediate cardiac and respiratory stabilization was
provided by double-lung HFJV and apneic oxygenation under hyperbaric conditions
at 2.5 atmospheres absolute for 35 min (SaO2 100%). The patient recovered from
surgery but died of non-Hodgkin lymphoma. CONCLUSION: The combination of
different ventilation modes including HFJV and the additional use of HBO resulted
in sufficient oxygenation during tracheal repair.
PMID- 10674514
TI - Biting the laryngeal mask: an unusual cause of negative pressure pulmonary edema.
AB - PURPOSE: To describe negative pressure pulmonary edema due to biting of the
laryngeal mask tube at emergence from general anesthesia. CLINICAL FEATURES: A
healthy patient underwent general anesthesia using a laryngeal mask airway and
mechanical ventilation. During recovery, the patient strongly bit the laryngeal
mask and made very forceful inspiratory efforts until the mask was removed. Five
minutes later, the patient developed dyspnea and had an hemoptysis of 50 ml fresh
blood. Chest radiograph showed bilateral alveolar infiltrates. Pharyngo-laryngeal
examination was normal. Bronchoscopy revealed no injury but diffuse pink frothy
edema fluid. Clinical examination and chest radiograph became normal after 12 hr
of nasal oxygen therapy confirming airway obstruction as the most available cause
of this pulmonary edema. CONCLUSION: Airway obstruction due to biting of a
laryngeal mask tube may result in negative pressure pulmonary edema.
PMID- 10674515
TI - Analysis of anesthesia physician resources: projected Ontario deficit in 2005.
AB - PURPOSE: To clarify the recent perception of shortfalls in anesthesia physician
resources, two models were used to assess these resources in Ontario, Canada.
METHODS: Two models, demand-based and benchmarking, were used. In the demand
based model estimated future supply and attrition were obtained from information
on Ontario Ministry of Health funded trainees. Data from the Canadian Residents
Matching Service and the Association of Canadian University Departments of
Anesthesia were also used. Current demand was identified from a telephone survey
of Departments of Anesthesia in ten Ontario cities. The number of anesthesia
practitioners in Ontario was estimated from the 1996 Canadian Anesthesiologists'
Society Physician Resource Database (CASPRD) in the demand-based model. In the
benchmarking model, using Alberta as the closest published analogue to Ontario,
the annual specialist growth rate in Ontario since 1986 was calculated in the
literature as 2.8%/yr for 1986-1994. The number of anesthesiologists in Ontario
from the 1986 CASPRD was used to calculate need based on that growth rate.
Results are compared with population to anesthesiologist (P/A) ratios calculated
from Statistics Canada population data and physician numbers from CASPRD.
RESULTS: A shortfall in the number of anesthesiologists has been identified. The
P/A ratio worsened by 17.6% from 1986 to 1996. The demand-based model indicated
that the shortfall is increased from a current deficit of 40 to 68 by 2005, using
CASPRD. Benchmarking showed that the estimated shortfall in 1994 was 131.
CONCLUSION: This conservative approach indicates that the shortfall in
anesthesiologist physician resources will worsen by 2005.
PMID- 10674516
TI - Cervical plexus anesthesia for carotid endarterectomy: comparison of ropivacaine
and mepivacaine.
AB - PURPOSE: To evaluate the effectiveness of cervical plexus block performed with
ropivacaine 0.75% or 1%, or mepivacaine 2%. METHODS: In a prospective,
randomized, double-blind study, 60 patients received deep cervical plexus block
with 0.2 ml x kg(-1) divided among C2-C4 injections using ropivacaine 0.75% and
1% or mepivacaine 2%. A blinded observer recorded loss of pin-prick sensation
every minute in the C2-C4 dermatomes until readiness for surgery. Then, a
superficial cervical block was performed with 0.15 ml x kg(-1) lidocaine 1%. The
need for intraoperative supplemental analgesia and degree of pain and time of
first postoperative pain medication were also recorded. RESULTS: General
anesthesia was not required to complete surgery in any case. No differences in
the need for intraoperative supplemental analgesia was observed (7, 6, and 9
patients with ropivacaine 0.75% and 1% or mepivacaine 2%, respectively).
Readiness to surgery required 15 (10-25) min with ropivacaine 0.75%, 18 (8-20)
min with ropivacaine 1%, and 15 (5-20) min with mepivacaine 2% (P = NS); while
patients asked for first postoperative pain medication after 10 (4-13) hr and 9
(6.5 - 11) hr with ropivacaine 0.75% and 1% compared with 5 (0-8) hr with
mepivacaine 2% (P<0.05). CONCLUSION: Ropivacaine 0.75% or 1% are appropriate
choices when performing cervical plexus anesthesia for carotid endarterectomy,
providing nerve block characteristics similar to those of mepivacaine 2%, but
with the advantage of longer postoperative pain relief.
PMID- 10674517
TI - Paroxystic systemic hypertension during inhalation induction with sevoflurane 8%.
PMID- 10674518
TI - Transthoracic echocardiography pre-, intra-, and postoperatively.
PMID- 10674519
TI - Axillary blockade by the targeted method. Added benefit?
PMID- 10674520
TI - Sevoflurane sedation.
PMID- 10674521
TI - Stroke.
PMID- 10674522
TI - Delta CK-MB outperforms delta troponin I at 2 hours during the ED rule out of
acute myocardial infarction.
AB - It has been shown that a rise in creatine kinase MB bank (CK-MB) of > or = + 1.6
ng/mL in 2 hours is more sensitive and equally specific for detection of acute
myocardial infarction (AMI) as compared with a 2-hour CK-MB > or = 6 ng/mL during
the emergency department (ED) evaluation of chest pain. Because cardiac specific
troponin I (cTnI) is thought to have similar early release kinetics as compared
with CK-MB mass, we undertook a retrospective cohort study in 578 chest pain
patients whose baseline CK-MB and cTnI was less than two times the hospital's
upper limits of normal and who underwent a 2-hour CK-MB and cTnI to compare
sensitivities and specificities of the 2-hour delta CK-MB (deltaCK-MB) and delta
cTnI (delta cTnI) for AMI and 30-day Adverse Outcome (AO). Thirty day AO was
defined as AMI, life-threatening complication, death, or percutaneous
transluminal coronary angioplasty (PTCA)/coronary artery bypass graft (CABG)
within 30 days of ED presentation. Optimum delta values were determined by
choosing the smallest cutoff value greater than the assay precision where the
deltaCK-MB and delta cTnI had a positive likelihood ratio for 30-day AO of > or =
15. A deltaCK-MB > or = +1.5 ng/mL was more sensitive than a deltaTnI > or = +0.2
ng/mL for AMI (87.7% versus 61.4%; P < .0005) and 30-day AO (56.7% versus 42.3%;
P < .005). There were no differences in specificities for AMI and 30-day AO.
Combining the two tests (MBdelta > or = +1.5 ng/mL and/or a deltaTnI > or = +0.2
ng/mL) resulted in an incremental increase in sensitivity of 89.5% for AMI and
61.9% for AO (P < .005). Patients with either a rise in CK-MB of > or = +1.5
ng/mL or rise in cTnI of > or = +0.2 ng/mL in 2 hours should receive
consideration for aggressive antiischemic therapy and further diagnostic testing
before making an exclusionary diagnosis of nonischemic chest pain.
PMID- 10674523
TI - Predicting discharge in uncomplicated near-drowning.
AB - To determine if routine, noninvasive parameters could be measured which predict
early (4-6 hour) discharge from the emergency department (ED) in mildly
symptomatic and asymptomatic victims of childhood near-drowning, a retrospective
cohort study was undertaken. Patients with fresh water near-drowning were studied
over a 3-year period who presented with Glascow Come Scale (GCS) > or =13 and
required no advanced life support prior to or < or =4 hours after ED
presentation. Three groups of patients were found: 39 patients (81%) had normal
pulmonary examination (PEx) and normal room air oxygen saturation (RASaO2) by 4
to 6 hours and did not deteriorate during the hospital admission (<24 hours); 5
patients (10%) had normal PEx by 4 to 6 hours and RASaO2 by 8 to 12 hours and did
not deteriorate during hospitalization (<24 hours). Four patients (8%) were
hospitalized for more than 24 hours. No patient with normal RASaO2 at 6 hours
deteriorated while in the hospital (CI 92.3-100%). Children who present to the ED
with GCS > or =13 and have normal PEx/respiratory effort and RA-SaO2 more than
95% at 4 to 6 hours after ED presentation can be safely discharged home.
PMID- 10674524
TI - Use of the intubating laryngeal mask airway by medical and nonmedical personnel.
AB - The intubating laryngeal mask airway (ILMA) is a newly available device designed
to allow for blind endotracheal intubation and treatment of patients with
difficult airways. We studied the intubation success rates and speed with initial
use of this device on an intubation manikin to determine whether this device
might be easily used by trained and untrained personnel. Rapid and successful
intubation with a device requiring limited or no training could have widespread
implications for both health care providers and laypersons. The study consisted
of 2 parts. In part 1, health care providers with intubation experience, health
care providers without prior intubation experience, and nonmedical personnel were
instructed to enter a room and intubate a manikin using the ILMA. A single page
set of schematic directions was provided within the ILMA setup. The main outcomes
were the intubation success rate and the time required for successful ventilation
and intubation. In part 2, participants were retested after a standardized <60
second device demonstration. The 111 participants in the study included 44
emergency physicians (40%), 21 anesthesiologists (19%), and 46 other medical or
nonmedical personnel (41%). On first attempted use of the device, and with no
prior training, 59% of all participants successfully intubated the manikin.
Attending and resident physicians had an 83% initial success rate. The median
time to ventilation was 47 seconds, and the median time from ventilation until
intubation was 29 seconds. Following the <60 second demonstration, 108 of 111
(97%) participants achieved success, with the median time to ventilation 18
seconds, and the median time from ventilation until intubation 17 seconds. All
attending and resident physicians succeeded in intubation following the
demonstration. Success rates on first attempt correlated with level of training,
prior intubation experience, and prior LMA use (all P < .001). After a <60 second
demonstration, medical and nonmedical personnel with and without prior intubation
training can successfully use the ILMA to rapidly establish an airway in a
manikin model. The ILMA should be further studied to determine if it may permit
endotracheal intubation by first responders, paramedical personnel, and other
medical staff with limited or no laryngoscopy skills.
PMID- 10674525
TI - Health promotion practices of emergency physicians.
AB - In this article we describe health promotion practices of emergency physicians
(EPs). A survey was mailed to members of the West Virginia American College of
Emergency Physicians. Main outcomes included the EP's beliefs regarding health
promotion, perceived roles in health promotion, and perceived effectiveness in
modifying the behavior of patients. Over 90% of respondents routinely asked about
cigarette smoking and half about alcohol use. A minority routinely asked about
illicit drug use, diet, exercise, domestic violence, or stress. The majority
stated they were the main person responsible for patient health education in
their emergency department (ED). Most felt prepared to counsel patients about
smoking (68%) and alcohol (59%), although very few described themselves as
successful in helping patients change their behavior. Although EPs feel
responsible for promoting the health of their patients, only a minority reported
routinely screening and counseling patients about prevention and most were not
confident in their ability to help patients change their health-related
behaviors.
PMID- 10674526
TI - Phospholipase A2-induced coagulation abnormalities after bee sting.
AB - We will examine the correlation between various bee venom phospholipase A2 (PLA2)
concentrations and several parameters of coagulation in human plasma in order to
offer a rationale for requesting a particular laboratory coagulation test after
bee sting(s). We will also evaluate in vitro the influence of clinically
available drugs with a noncompetitive inhibitory effect on PLA2 on the
anticoagulant effect of bee venom PLA2. Prothrombin index (PTi), partial
thromboplastin time (PTT), antithrombin III (AT III), soluble fibrin monomers
(SFM), the activity of coagulation factors I, II, V, and VIII, and
thrombelastography (TEG) parameters (split point [Sp], reaction time [R], kinetic
time [K], coagulation time [R + K], maximal amplitude [MA], and the growth angle
[alpha]) were determined before and after addition of 1.4, 2.7, and 4.1 units (1,
2, and 3 microg protein respectively) of bee venom PLA2. Linear regression was
used to determine the significance of the relationship between these coagulation
parameters and bee venom PLA2 concentrations used. To study the influence of
ketamine, lidocaine, magnesium, furosemide, and cromolyn on the anticoagulant
effect of bee venom PLA2, PTi and factor II- and V-activities were measured
before and after addition of 2.7 units of PLA2 and PLA2 plus one of the tested
substances. Determinations of F II, PTi, F V, and F VIII showed a negative
correlation to bee venom PLA2 concentration (r = -0.88, -0.86, -0.81, and -0.79
respectively). A positive correlation was found for PTT (r = 0.69). FII- activity
and PTi correlated better with bee venom PLA2 concentration than other
parameters. F I, AT III, and SFM showed no changes. Whereas Sp, R, and K were
prolonged by bee venom PLA2 and a was reduced, there was no correlation to the
PLA2 concentration. Addition of none of the 5 substances could correct the
effects of bee venom PLA2 on the coagulation. In a patient with toxic reaction or
a severe anaphylactic reaction after bee sting(s) we suggest determinations of
FII and/or PTi. This will allow a quick and economical assessment of coagulation
abnormalities after bee sting(s). Noncompetitive PLA2-inhibitors (ketamine,
lidocaine, magnesium, furosemide, and cromolyn) are unable to correct in vitro
the anticoagulant effect of bee venom PLA2. They cannot be recommended at this
stage for this purpose. Further investigations with competitive PLA2-inhibitors
are warranted.
PMID- 10674527
TI - Duration of patient immobilization in the ED.
AB - In this article we seek to determine the duration of immobilization in patients
presenting to the emergency department (ED). We conducted a 10-week prospective
study of a convenience sample of patients transported to a level one trauma
center immobilized with a backboard and cervical collar. Total backboard time
(TBT) was measured from the time the ambulance left the scene to the time the
patient was removed from the backboard, while total ED backboard time (TEDBT) was
measured from the time of arrival at the ED to the time of backboard removal.
There were 138 patients entered in the study. Insufficient data excluded 36
patients from further analysis. TBT was available for 92 patients and averaged
63.63 (+/-45.87) minutes. Dividing patients into those who were removed from the
backboard prior to radiographs (n = 85), the TBT average was 53.9 minutes (+/
30.1), whereas the average for those who had radiographs prior to removal from
the backboard (n = 7) was 181.3 minutes (+/-41.6). There were 102 patients for
whom TEDBT was available and averaged 46.36 (+/-44.88) minutes. Dividing patients
into those who were removed from the backboard prior to radiographs (n = 95), the
TEDBT average was 37.6 minutes (+/-29.6), whereas the average for those who had
radiographs prior to removal from the backboard (n = 7) was 165.3 minutes (+/
49.7). Patients are left on backboards for significant periods of time even when
no radiographs are taken prior to backboard removal.
PMID- 10674528
TI - Global brain ischemia produced by clamping left subclavian artery and bicarotid
trunk in the rabbit.
AB - Thirty-five rabbits were divided randomly into 5 groups: sham operation, 10
minutes clamping bicarotid trunk (partial ischemia, PI), and 3 groups of 5, 7,
and 10 minutes clamping left subclavian artery and bicarotid trunk (global
ischemia, GI). Systolic arterial pressure increased slightly in the PI group, but
doubled in the GI groups during clamping. Heart rate did not change in the PI
group, but decreased transiently in the GI groups during clamping. Brain
temperature decreased gradually in the GI groups during clamping, but did not
change in the PI group. Necrotic changes were present 96 hours later in
approximately 50% of the hippocampal CA1 cells in the GI groups, but in none of
the cells in the PI and sham operation groups. The present results may indicate
that clamping left subclavian artery and bicarotid trunk in the rabbit brings
about global brain ischemia.
PMID- 10674529
TI - The efficacy of oral deferiprone in acute iron poisoning.
AB - Due to its high cost and need for parenteral administration, the standard iron
chelator deferoxamine is not used in many individuals with acute and chronic iron
poisoning worldwide. Deferiprone is the first oral iron chelator to be shown to
be effective in chronically iron overloaded thalassemia patients. Its efficacy,
by oral administration, in acute iron poisoning has not been tested. Our
objective was to determine whether orally administered deferiprone can reduce the
mortality of rats following acute, toxic, oral doses of iron. Rats were
administered 612 mg/kg elemental iron orally, corresponding to LD50 in the
species tested. Two other groups received the same oral dose of iron followed by
oral deferiprone: 800 mg/kg and 800 mg/kg, followed by another dose of 800 mg/kg
2 hours later. Coadministration of 800 mg/kg deferiprone with the iron decreased
mortality from 30% to 6.6% after 2 hours (P = .02), from 40% to 16.6% after 12
hours (P = .04), and from 53.3% to 20% after 24 hours (P = 0.007). Mortality was
also significantly decreased among animals coadministrated 2 repeated doses of
deferiprone of 800 mg/kg with iron, to 0%, 9%, and 18%, and 2, 12, and 24 hours
postdrug administration, respectively (P = .04, .05, .04, respectively).
Histologically, there was a dose-dependent decrease in iron accumulation in the
gastrointestinal tract. Orally administered deferiprone can decrease morbidity
and mortality caused by acute iron overdose in rats. Oral deferiprone holds
promise in the treatment of iron poisoning in humans.
PMID- 10674530
TI - A preliminary evaluation of emergency ultrasound in the setting of an emergency
medicine training program.
AB - In this article we seek to evaluate the diagnostic accuracy of emergency
physicians performing emergency ultrasonography in the setting of an emergency
medicine training program. A prospective observational study was performed at an
inner city Level I trauma center with an emergency medicine residency training
program. From July 1994 to December 1996 a convenience sample of ultrasound exams
was recorded. The diagnostic quality ("acceptable or technically limited") was
determined by a board-certified cardiologist or radiologist with fellowship
training in ultrasonography. The emergency department interpretations were then
compared to those of the blinded cardiologist or radiologist. Four hundred and
fifty-six ultrasound examinations were videotaped and entered into the study; 408
(89%) of the studies performed were determined to be "acceptable." The diagnostic
accuracy (sensitivity, specificity, positive and negative predictive values) of
these studies were as follows: cardiac, to rule out effusion (n = 67; 0.83, 0.98,
0.88, 0.98); transabdominal, to rule out abdominal aortic aneurysms (AAA),
cholelithiasis, or free peritoneal fluid (n = 263; 0.91, 0.89, 0.88, 0.92);
renal, to rule out hydronephrosis (n = 45; 0.94, 0.96, 0.94, 0.96); pelvic, to
rule in intrauterine pregnancy (n = 33; 1.0, 0.90, 0.96, 1.0). The 48
"technically limited studies" included: 39 transabdominal (33 gallbladder, 1
abdominal aortic aneurysm, 5 free peritoneal fluid), 6 cardiac, 2 renal, and 1
pelvic ultrasound. This study suggests that emergency physicians with a minimal
amount of training display acceptable technical skill and interpretive acumen in
their approach to emergency ultrasonography.
PMID- 10674531
TI - Diagnosis of acute thoracic aortic dissection in the emergency department.
AB - In this article we try to determine how frequently emergency physicians (EPs)
suspected the diagnosis in acute aortic dissection (AD). In this retrospective
descriptive study, we identified all patients with the final diagnosis of AD
initially evaluated in 1 of 3 emergency departments (EDs) over a 5-year period.
Patients were included if AD was not suspected before ED evaluation. Patients
undergoing thoracic aorta imaging as the initial ED study were defined as
suspected AD. Forty-three patients totaling 44 presentations were identified. EPs
suspected AD in 19 of 44 presentations. EPs suspected AD in 12 of 14 (86%) cases
of chest and back pain and in 5 of 11 (45%) of chest pain. Thirteen of 39 (33%)
painful presentations involved abdominal pain; EPs suspected AD in 1 of 13 (8%).
EPs suspected the diagnosis in 43% of acute AD; location of pain was most
predictive of a suspected diagnosis.
PMID- 10674532
TI - Use of complementary and alternative medicine among Dominican emergency
department patients.
AB - This small, pilot study examined presenting complaint, brief health history, use
of complementary and alternative medicine (CAM), and sociodemographic
characteristics, among patients attending the emergency department (ED) of a
large urban hospital. The sample (n = 50) was primarily Dominican and of low
socioeconomic status. Almost half had used CAM for their presenting complaint or
another health problem during the past year, most commonly in the form of
medicinal plants made into herbal teas. CAM users were more likely to be female,
longer-term residents of the United States, and to have also used religious
practices for health problems. Subjects who had used CAM for any problem other
than the presenting complaint during the past year rated its effectiveness higher
than subjects who had used CAM for their presenting complaint. In conclusion, it
is likely that a significant proportion of Dominican ED patients use CAM,
suggesting that they should be asked about their CAM use during triage.
PMID- 10674533
TI - Unstable cervical spine without spinal cord injury in penetrating neck trauma.
AB - Cervical spine instability in the neurologically intact patient following
penetrating neck trauma has been considered rare or non-existent. We present a
case of a woman with an unstable C5 fracture without spinal cord injury after a
gunshot wound to the neck. Considerations regarding the risk of cervical spine
instability are discussed, as well as suggestions for a prudent approach to such
patients.
PMID- 10674534
TI - Sternoclavicular joint injuries.
AB - Injuries to the sternoclavicular (SC) joint are infrequently encountered.
However, retrosternal SC joint dislocations are potentially life-threatening
injuries which must be recognized by the examining physician and treated as soon
as possible. Plain radiography often fails to fully distinguish SC joint
injuries, and computed tomography has emerged as the diagnostic modality of
choice for defining the injury complex and surrounding injuries. We have
encountered 6 cases of SC joint injuries over the past 3 years and describe their
presentation and management.
PMID- 10674535
TI - The mosh pit experience: emergency medical care for concert injuries.
AB - Effective planning is essential for medical personnel preparing to provide
emergency care at mass gatherings. At large concerts where audience members
participate in "moshing," crowd surfing, and stage diving, there may be a
potential for a dramatic increase in injuries requiring medical attention.
Injuries seen at emergency medical stations at 3 concerts, all with large mosh
pits, over 4 event days were recorded and evaluated. Each event day had over
60,000 attendees. A total of 1,542 medical incidents (82.9 per 10,000) were
reported over the 4 event days. There were 37% (466 patients, 25.1 per 10,000) of
incidents related to moshing activity. Hospital transport was required for 2.5%
(39 patients, 2.1 per 10,000) of medical visits with 74% (29 patients, 1.5 per
10,000) of those transported being for mosh pit-related injuries. When planning
emergency medical care for such concerts with mosh pits, the potential for an
increase in the number of medical incidents and injuries requiring medical
attention and hospital transport should be taken into account for efficient
medical coverage.
PMID- 10674536
TI - Green lynx spider (Peucetia viridans) envenomation.
AB - Four cases of envenomation by green lynx spiders (Peucetia viridans) are
reported. Despite the unusual appearance and occasional aggressive behavior of
this spider, envenomation caused only local pain, pruritus, erythema, and
induration. No local necrosis or systemic symptoms occurred. Treatment included
tetanus immunization, wound care, and symptomatic therapy.
PMID- 10674537
TI - Benefits of an informational videotape for emergency department patients.
AB - To determine if an informational videotape affected patient's attitudes towards
their emergency department visit, we conducted a prospective study using a
convenience sample of patients waiting to be seen at a southern California
emergency department. Patients waiting to be treated were randomized to view an
informational videotape or to receive standard management (no videotape). The
informational videotape lasted 6 minutes and served to orient the patients to the
emergency department. It showed the sequence of steps from entry into the
department to discharge, the nature of triage and causes for delays, the
different services offered by the emergency department, and the roles of each of
the department staff members. One week after discharge, patients were contacted
at home by telephone and were asked to rate various aspects of their emergency
department experience. A comparison of the telephone survey rankings between
those who viewed the videotape (98 patients) and those who did not (100 patients)
revealed statistically significant improvements in the former group on questions
about level of anxiety and appropriateness of delays. An informational videotape
for patients in waiting areas may be a useful tool to educate about emergency
medical services, to reduce anxiety, and to improve satisfaction with the
emergency department stay.
PMID- 10674538
TI - Ultrasound guided reduction of pediatric forearm fractures in the ED.
AB - Reducing badly displaced or angulated pediatric forearm fractures in the
emergency department can be difficult. Multiple attempts at reduction may be
required, with repeated trips to the radiology department, before an adequate
reduction is achieved. We have recently found that bedside ultrasound by
emergency physicians is very helpful in guiding the reduction of difficult
forearm fractures, allowing the physician to assess the adequacy of the reduction
at the patient's bedside. In this report, we describe the technique we have
developed for ultrasound-guided fracture reduction and present three case
histories showing the usefulness of this technique.
PMID- 10674539
TI - Delayed presentation of abdominal bleeding in a teenage boy after a fall.
AB - The delayed presentation of an abdominal bleed in a victim of a fall is a rare
occurrence. In the multiple injured patients, even with an intact sensorium,
competing pain from associated injuries may mask the pain from a occult injury.
Although a rare occurrence of abdominal injury in an asymptomatic neurologically
intact patient, in the patient requiring a computed tomography scan of a spinal
fracture, it may be worthwhile to image the abdomen and pelvis as well to rule
out a concomitant occult abdominal injury. Current literature regarding injuries
associated with falls from height are discussed that support this position and
the delayed manifestation of an abdominal bleed in a 17-year-old boy 1 day after
a fall is presented.
PMID- 10674540
TI - A sighting of orbital pseudotumor.
AB - A 39-year-old woman developed bilateral proptosis, photophobia, and pain with
extraocular movements over the course of 5 days. Her findings initially were
ocular pain and photophobia which progressed to periorbital edema and nasal
discharge ultimately resulting in proptosis with vertical globe displacement and
decreased visual acuity. She was diagnosed with corneal abrasion and sinusitis
respectively during two initial emergency department visits. On her third visit
to the emergency department within 4 days, she developed acute visual deficits.
The patient was subsequently diagnosed with orbital pseudotumor after computed
tomography scan revealed inflammation of orbital structures bilaterally.
PMID- 10674541
TI - Cases in electrocardiography.
PMID- 10674542
TI - Unruptured cerebral aneurysm producing a thunderclap headache.
AB - A sudden and severe headache is the most common presentation of an acutely
ruptured cerebral aneurysm. A similar headache in the absence of subarachnoid
blood has rarely been ascribed to an unruptured cerebral aneurysm, but may result
from acute aneurysm expansion and indicate a high risk of future rupture. We
present a patient who developed a sudden, severe, "thunderclap" headache, with no
associated neurological deficit. Computed tomogram and lumbar cerebral spinal
fluid obtained 5.5 hours after headache onset were negative for subarachnoid
hemorrhage. The patient underwent cerebral angiography which revealed a posterior
communicating artery aneurysm with an associated daughter aneurysm. Craniotomy
and clip obliteration of the aneurysm were performed. The aneurysm dome was very
thin and there was no evidence of recent or old hemorrhage. A "thunderclap"
headache without subarachnoid hemorrhage may be an important harbinger of a
cerebral aneurysm with the potential for future rupture. Early recognition and
neurovascular imaging of aneurysms presenting in this rare fashion are warranted.
PMID- 10674543
TI - Continuous and bilevel positive airway pressure in the treatment of acute
cardiogenic pulmonary edema.
AB - Patients with acute cardiogenic pulmonary edema (ACPE) are commonly seen in the
emergency department (ED). Although the majority of patients respond to
conventional medical therapy, some patients require at least temporary
ventilatory support. Traditionally, this has been accomplished via endotracheal
intubation and mechanical ventilation, an approach that is associated with a
small but significant rate of complications. The past 2 decades have witnessed
increasing interest in methods of noninvasive ventilatory support (NVS), notably
continuous positive airway pressure (CPAP) and bilevel positive airway pressure
(BiPAP). We review the physiological consequences, clinical efficacy, and
practical limitations of CPAP and BiPAP in the management of ACPE.
PMID- 10674544
TI - Current controversies in the management of minor pediatric head injuries.
AB - Each year hundreds of thousands of children receive care in emergency departments
after head injury. Minor head injuries account for a majority of these injuries.
The prevalence, morbidity, and costs associated with pediatric minor head
injuries make it an important topic. We review the management of pediatric minor
head injury, emphasizing current areas of controversy, including criteria for
neuroimaging, indications for hospitalization, the role of anticonvulsant
therapy, and the long-term neurobehavioral sequelae of pediatric minor head
injury.
PMID- 10674545
TI - Future of the emergency physician: subject or citizen?
AB - Seventy-seven percent of emergency physicians (EPs) work as either employees or
independent contractors (ICs). In contrast, other hospital-based physicians such
as radiologists and anesthesiologists have a much higher percentage of ownership
in their medical practices. The development of a high percentage of nonownership
arrangements among EPs finds a useful historical comparison in the
industrialization of nonhealth care workers over the past 100 years. Unless
significant changes occur in emergency medicine (EM) organization and practice
structures, EPs will have less self-determination over their practice compared
with other specialties. This will inevitably result in less self-determination
for their future. Combined with the great strides EM has achieved as a specialty,
EPs' brightest future lies in being citizens of a broader, more expansive, all
encompassing EM practice.
PMID- 10674546
TI - The intravenous use of coconut water.
AB - Medical resources routinely used for intravenous hydration and resuscitation of
critically ill patients may be limited in remote regions of the world. When faced
with these shortages, physicians have had to improvise with the available
resources, or simply do without. We report the successful use of coconut water as
a short-term intravenous hydration fluid for a Solomon Island patient, a
laboratory analysis of the local coconuts, and a review of previously documented
intravenous coconut use.
PMID- 10674547
TI - A bartender fixes a curious drink.
PMID- 10674548
TI - Coronary vasospasm in a patient suffering from sarin poisoning.
PMID- 10674549
TI - Ruptured thoracic aorta aneurysm after spontaneous pneumothorax drainage.
PMID- 10674550
TI - Intussusception of a normal appendix.
PMID- 10674551
TI - Inferior hip dislocation in an adult: does a rare injury now have a common
mechanism?
PMID- 10674552
TI - Behcets disease in an African American man.
PMID- 10674553
TI - The effect of introducing bedside TV sets on patient satisfaction in the ED.
PMID- 10674554
TI - CO poisoning caused by inhalation of CH3Cl contained in personal defense spray.
PMID- 10674555
TI - Fluid loading: neither safe nor efficacious in the treatment of the alcohol
intoxicated patient in the ED.
PMID- 10674556
TI - The results of a randomized controlled trial of hydrocortisone in acute
exacerbation of COPD.
PMID- 10674557
TI - The spectrum of anaphylaxis.
PMID- 10674558
TI - Role of staphylococcal superantigens in atopic dermatitis: from colonization to
inflammation.
AB - OBJECTIVE: This review article has been prepared in order to enable the readers
to understand the role of staphylococcal superantigens (SsAgs) in atopic
dermatitis (AD). DATA SOURCES: MEDLINE literature search was performed for
obtaining references. Recent reviews, research articles, poster presentations,
and letters (to the editor) were meticulously reviewed. RESULTS: (1) SsAgs
contribute to the pathogenesis of cutaneous inflammation in AD with five
potential mechanisms: Direct stimulation of antigen presenting cells (APCs) and
keratinocytes. Stimulation of T cell proliferation [superantigenic binding to T
cell receptor (TCR)]. Expansion of skin-homing cutaneous lymphocyte antigen (CLA)
(+) T cells. The role of superantigens as allergens. Reduction of apoptosis. (2)
Effectiveness of antibiotic therapy in AD patients without signs of bacterial
infection is still under discussion. If signs of skin infection are present,
antibiotic therapy (topical/oral) may help exacerbations of AD. Prolonged
topical/oral antibiotic therapy, however, may cause development of antibiotic
resistant strains of Staphylococcus aureus (SA). CONCLUSIONS: Atopic dermatitis
is a genetically determined, chronically relapsing, inflammatory skin disease
which has many aspects and a complex immunopathogenesis involving both immediate
and cellular immune responses. While the pathogenic role of SsAgs may not be of
primary importance, SsAgs appear to be one of the important triggering factors
that contribute to the cutaneous inflammation in AD. We suggest that
staphylococcal colonization does not always mean SsAg-mediated inflammation, and
anti-staphylococcal treatment should be considered in cases with signs of
bacterial infection.
PMID- 10674559
TI - Two contrasting cases of anaphylaxis seen simultaneously.
PMID- 10674560
TI - Comparison of the Burkard and Allergenco MK-3 volumetric collectors.
AB - BACKGROUND: The Burkard sampler is a widely used volumetric pollen and spore
collector, in part, because it is wind-oriented, it has consistent flow
characteristics, and it permits time-discrimination of collected particles. Its
main disadvantages are that it is heavy, expensive, and visual counting is very
time-consuming. A less-expensive volumetric collector with time discrimination
capabilities could permit more widespread particle counting which would enhance
our understanding of aerobiology. OBJECTIVE: The objective of this study is to
compare the collection recoveries of the Burkard sampler with a less-expensive
non-wind oriented collector, the Allergenco MK-3, under various wind speeds.
METHODS: Pollen and spore counts were compared on 20 sampling days during the
spring pollen season using a Burkard and Allergenco MK-3 located next to each
other on the roof of a 5-story hospital building. A weather station was placed
nearby and wind velocity was concurrently measured. RESULTS: The median wind
velocity was 6 miles/hour with a maximum of 35 miles/hour. The Burkard and
Allergenco MK-3 collectors displayed similar collection characteristics at all
wind velocities for both pollen and spores. The Burkard gave lower counts than
the Allergenco when absolute particle counts were low and similar values at
higher absolute counts. CONCLUSIONS: Given our data, we conclude that ambient
wind speed has no significant effect on collection efficiency at velocities
commonly found on the roof of our hospital and that the collection
characteristics of the Burkard and Allergenco MK-3 are comparable.
PMID- 10674561
TI - Distribution of primary immunodeficiency diseases diagnosed in a pediatric
tertiary hospital.
AB - BACKGROUND: Advances in immunologic techniques in recent years have led to
increased recognition of primary immunodeficiency disorders, with IgA deficiency
the most common phenotype reported by most registries. There have also been
reports of increased associated incidence of autoimmunity, allergy, and other
diseases. OBJECTIVES: We wished to determine the percentage of different primary
immunodeficiency disorders seen in a pediatric tertiary hospital and to determine
the association of primary immunodeficiency disorders with other diseases that
are not part of classic immunodeficiency disorders. METHODS: We performed a
retrospective review of the patients referred to our allergy/immunology clinic
for immunologic evaluation of recurrent infections during an 8-year period. We
also reviewed pathology reports with postmortem diagnosis of immunodeficiencies
not identified while patients were alive. RESULTS: Of the 91 patients with
primary immunodeficiency disorders evaluated, the majority had predominantly
antibody deficiencies (67%). The most common phenotype was specific antibody
deficiency with normal immunoglobulins (23.1%), defined as inability to mount an
adequate response to pneumococcal polysaccharides followed by IgG2 subclass
deficiency (17.6%). These two phenotypes were diagnosed mostly in the last 2
years of the survey. Associated diseases, found in 40% of patients, were mostly
allergic conditions followed by syndromic/chromosomal disorders. CONCLUSION: The
study reveals that specific antibody deficiency with normal immunoglobulins
followed by IgG2 subclass deficiency was the most frequently diagnosed primary
immunodeficiency disorder in our patient population. It also indicates that
immunodeficiency disorders should be considered in patients with other
abnormalities like allergic and syndromic/chromosomal disorders that present with
recurrent infections.
PMID- 10674562
TI - Carpet properties that affect the retention of cat allergen.
AB - BACKGROUND: Although the importance of carpeting on airborne levels of cat
allergen (Fel d 1) has been demonstrated, no studies have been performed to
determine specific properties of carpet that may affect its retention and
removal. OBJECTIVES: This study characterizes factors that affect the retention
of cat allergen on tufted carpets. The experiments were designed to test the
hypothesis that the amount of allergen-containing dust recovered from vacuum
samples of tufted carpet sources was dependent on micro (fiber) or macro
(construction) retention properties of carpets. METHODS: Twenty-six types of
custom manufactured carpet were spiked and embedded with reference dust
containing Fel d 1. A standardized vacuum surface sampler was used to recover
dust from the samples. Allergen was assayed using a standard, monoclonal antibody
ELISA. RESULTS: Carpet-surface area and fluorocarbon-fiber treatments were found
to have the largest effects on retention and recovery of cat allergen. The style
per se of a carpet, such as loop or cut pile, does not affect allergen retention.
These results are generally in agreement with previous studies on dust mite
allergen retention. CONCLUSIONS: Carpets that are easiest to clean would have the
following properties for release of cat allergen and in this order: low pile
density and height, fluorocarbon coating of fibers, high denier per filament, and
a fiber shape with a low surface area.
PMID- 10674563
TI - Cord blood IgE: its determinants and prediction of development of asthma and
other allergic disorders at 12 months.
AB - BACKGROUND: The value of cord blood IgE in predicting the development of asthma
and other IgE-mediated allergic diseases is unclear. OBJECTIVE: The purpose of
this study is twofold: (1) to determine factors affecting cord blood IgE level
and (2) to determine whether cord blood IgE predicts the development of asthma
and other IgE-mediated allergic diseases in high risk (defined as those with at
least one first degree relative with asthma or 2 first degree relatives with
other IgE-mediated allergic diseases) infants at 12 months. METHODS: The study
utilized cord blood obtained from a group of high risk infants who took part in a
randomized controlled trial to assess the effectiveness of an intervention
program in the primary prevention of asthma and other IgE-mediated allergic
diseases. Total IgE and cotinine in the cord blood were measured. Assessment of
the infants was done at 12 months for these diseases. RESULTS: Sixty-four (17.8%)
infants had detectable total IgE in cord blood >0.5 kU/L. The proportion of
infants with elevated cord blood IgE was significantly higher among nonwhites,
birth during winter months, and those with a maternal history of asthma. There
was no correlation between cord blood IgE and cord blood cotinine level. Cord
blood IgE was found to be a significant predictor for the development of
urticaria due to food allergy but not for other outcomes. CONCLUSION: Both
genetic and environmental risk factors play a role in determining the level of
IgE in cord blood. Cord blood IgE was a significant risk factor for the
development of urticaria due to food allergy at 12 months of life. As urticaria
due to food allergy is a prodrome for anaphylaxis, measurement of IgE in cord
blood may be indicated in infants at high risk for developing allergic diseases
so that preventive measures can be applied.
PMID- 10674564
TI - Oral iron cutaneous adverse reaction and successful desensitization.
AB - BACKGROUND: The oral administering of iron preparations sometimes produces
adverse gastrointestinal effects. In contrast, cutaneous reactions are extremely
rare. OBJECTIVE: We report a patient with several episodes of generalized
pruritus and erythematous maculopapular eruption after receiving oral compounds
of iron and on whom desensitization with oral iron was attempted. METHODS: We
studied a female with microcytic anemia due to gynecologic blood loss who
presented several episodes of cutaneous eruption after receiving oral compounds
of iron. Skin prick-test and two simple-blind, placebo-controlled oral challenges
were performed with various iron compounds, and finally desensitization with oral
iron was carried out. RESULTS: Skin prick-test and patch-test with iron
preparations were negative. Two simple-blind, placebo-controlled oral challenges
were performed and the patient began experiencing similar cutaneous symptoms. We
started a slow desensitization protocol using increasing doses until the target
amount of the drug was tolerated without adverse effects. The chronic
administration of oral iron therapy once a day for 9 months sustained the
desensitized state and the anemia disappeared. CONCLUSION: We present methods to
effectively manage iron supply for a microcytic anemia patient with cutaneous
reactions due to oral iron compounds, to avoid repeated transfusions, slow
desensitization with oral iron was successfully attempted.
PMID- 10674565
TI - Comparison of outdoor allergenic particles and allergen levels.
AB - INTRODUCTION: Spore and pollen counts have been used traditionally to determine
aeroallergen exposure. Using a liquid based collector and enzyme immunoassays, we
have developed methods for measuring airborne allergen concentrations. In this
work we test the hypothesis that airborne allergen concentrations are directly
related to spore and pollen counts. METHODS: Test samplers used included a high
volume cyclonic liquid impinger (SpinCon) and a standard spore trap (Burkard).
Samples were collected on a weekly basis from May to October and were analyzed
microscopically for spores and pollen grains. The liquid samples were analyzed by
enzyme-linked immunoassay for the presence of allergens from Alternaria,
Cladosporium, Aspergillus, oak, fescue, ragweed, and plantain. Specific
Alternaria allergens Alt al and GP70 also were measured. RESULTS: Pollen counts
for the SpinCon and Burkard collectors were similar, though spore counts were
lower with the SpinCon. Detectable amounts of three of the seven allergenic
species including fescue, ragweed, and Alternaria were present in air samples.
Concentrations of pollens were seen in their respective seasons while fungal
allergen levels varied throughout the period. Allergen levels generally agreed
with particle counts, however peak allergen levels and peak particle counts for
individual species did not correlate well. CONCLUSIONS: At flow rates of 236
L/min, the SpinCon is comparable to the Burkard for counting airborne pollen and
spores. Samples collected by the SpinCon permit quantitative determination of
allergen levels in outdoor air. The poor correlation between measured airborne
allergen and related particles indicates the potential for significant allergen
exposure in the absence of identifiable particles in air.
PMID- 10674566
TI - A cost-benefit analysis using a willingness-to-pay questionnaire of intranasal
budesonide for seasonal allergic rhinitis. Rhinocort Study Group.
AB - BACKGROUND: The cost-benefit of intranasal steroids for the treatment of seasonal
allergic rhinitis is unknown. OBJECTIVE: To determine the cost-benefit of
intranasal budesonide for seasonal allergic rhinitis. METHODS: Subjects who were
symptomatic for a baseline period of 7 to 10 days were randomized to receive
intranasal budesonide by Turbuhaler (400 microg) (n = 121) or aqueous spray (256
microg) (n = 121) once daily for 4 weeks. A willingness-to-pay questionnaire that
measured benefits of treatment was administered before and at study completion.
Costs were collected and compared with benefits. RESULTS: Subjects were willing
to spend on average $15.89/wk (range $1 to $75) to alleviate the problems of
seasonal ragweed rhinitis. Eighty percent of subjects felt that, with treatment,
rhinitis had less of an impact on their lives, compared with previous years. The
mean willingness-to-pay for the drug used during another ragweed season was
$12.95/wk. This was 92% (95% CI, 85% to 100%) of the pre-treatment estimate.
There was no relationship between an indirect assessment of income and
willingness-to-pay estimates. The benefit was greater than the cost by a mean of
$5.80/wk (95% CI, $3.52 to 8.08), P < .0001. There was no difference in costs,
willingness-to-pay, or cost-benefit comparing delivery modes. A sensitivity
analysis revealed the conclusions were robust. CONCLUSIONS: Intranasal budesonide
is cost-beneficial in the treatment of seasonal allergic rhinitis and a
willingness-to-pay questionnaire may provide a useful method to assess a
therapy's benefit.
PMID- 10674567
TI - Sparfloxacin for the treatment of acute bacterial maxillary sinusitis documented
by sinus puncture.
AB - PURPOSE: To evaluate the efficacy and safety of sparfloxacin in the treatment of
patients with acute bacterial maxillary sinusitis, the microbiologic etiology of
which was determined by maxillary sinus puncture. PATIENTS AND METHODS: Two
hundred fifty-three patients enrolled in the open, noncomparative trial received
sparfloxacin as a 400-mg loading dose followed by 200 mg once daily doses for a
total of 10 days. One hundred ninety-eight patients were clinically evaluable and
82 were also bacteriologically evaluable. All treated patients were included in
the safety analysis. Overall success was determined based on clinical success
(resolution or reduction of signs and symptoms and sinus x-rays) and
bacteriologic success (eradication and presumed eradication of baseline pathogens
obtained by maxillary sinus puncture and aspiration). RESULTS: Overall success in
the bacteriologically evaluable population at test-of-cure was 91.5% [75/82; 95%
confidence interval (85.4%, 97.5%)]. For all pathogens, the eradication rate was
93.2% (109/117 baseline pathogens); individual pathogen eradication rates were
88.9% (16/18) for S. pneumoniae (including those strains exhibiting decreased
susceptibility to penicillin); and 100% for H. influenzae (17/17), S. aureus
(14/14), and M. catarrhalis (11/11). The majority of adverse events were of mild
or moderate severity; the most frequently related adverse events were
photosensitivity reaction, headache, nausea, and diarrhea. CONCLUSION:
Sparfloxacin had an overall success rate of 91.5% for patients in this study and
was generally well tolerated in the treatment of acute bacterial maxillary
sinusitis.
PMID- 10674568
TI - Effects of sodium cromoglycate on cytokine production following antigen
stimulation of a passively sensitized human lung model.
AB - BACKGROUND: Interleukin-5 (IL-5) and tumor necrosis factor-alpha (TNF-alpha) play
key roles in bronchial asthma. Sodium cromoglycate (DSCG) and dexamethasone (Dex)
are used in the treatment of asthma as anti-inflammatory agents. OBJECTIVE: We
investigated whether DSCG inhibited the expression of IL-5 and TNF-alpha mRNA and
proteins from isolated human lungs, and compared these findings with those of
Dex. METHODS: Human lung specimens were passively sensitized with sera from
atopic patients, then preincubated in the presence of DSCG (10(-3), 10(-4), 10(
5) M) or Dex (10(-6) M) for 2 hours. The specimens were stimulated with
Dermatophagoides antigen, then cultured for 48 hours. The supernatant was
collected 1, 2, 4, 8, 24, and 48 hours to measure IL-5 and TNF-alpha by enzyme
linked immunosorbent assay. mRNA expression was examined by reverse transcriptase
polymerase chain reaction (RT-PCR). RESULTS: Tumor necrosis factor-alpha protein
reached a peak level at 4 hours (156.57 +/- 18.29 pg/mL). Dex decreased TNF-alpha
protein to 31.86 +/- 4.67 pg/mL (P < .001). There was also a decrease of TNF
alpha protein to 107.43 +/- 14.25 pg/mL by 10(-4) MD SCG (P < .001). Antigenic
stimulation also increased the release of IL-5 protein at 4 hours and the peak
level was observed at 24 hours (150.29 +/- 19.12 pg/mL). Dex decreased IL-5
protein to 28.57 +/- 5.27 pg/mL (P < .0001), 10(-4) M DSCG also decreased to
111.57 +/- 15.28 pg/mL (P < .05). RT-PCR analysis showed persistence of IL-5 and
TNF-alpha mRNA expression from 1 to 24 hour after antigen stimulation. Dex but
not DSCG inhibited IL-5 and TNF-alpha mRNA levels. CONCLUSION: Our results showed
that DSCG significantly inhibited IL-5 and TNF-alpha production by human lung
specimens, suggesting that it acts as an anti-inflammatory agent.
PMID- 10674569
TI - Increased perception of dyspnea by inhalation of short acting beta2 agonist in
patients with asthma of varying severity.
AB - BACKGROUND: Poor perception of dyspnea in asthma may lead to a delay in starting
appropriate treatment which is probably one of the factors contributing to death
from asthma. OBJECTIVE: This study was carried out to determine whether impaired
perception of dyspnea in patients with asthma of varying severity can be
corrected by inhalation of short acting beta2 agonist treatment. METHODS: We
enrolled 20 patients with asthma of varying severity. Forced expiratory volume in
one second (FEV1) was measured before and 10 minutes after two puffs of
salbutamol administered by metered dose inhaler. Perception of dyspnea was scored
on the Borg scale during breathing through an inspiratory muscle trainer.
RESULTS: After inhalation of short acting beta2 agonist treatment, the baseline
Borg score was decreased significantly from 2.20 +/- 0.32 to 1.80 +/- 0.31 (P <
.01). The Borg score during breathing with the highest resistance, on the
contrary, was increased significantly from 6.25 +/- 0.35 to 6.90 +/- 0.35 after
inhalation of short acting beta2 agonist treatment (P < .01). Highest resistance
induced score difference from the baseline value (highest resistance-load score)
was increased significantly from 4.10 +/- 0.46 to 5.25 +/- 0.42 (P < .01). There
was no relationship between the change of Borg score from baseline value at each
resistive load and the % change of FEV1 after inhalation of short acting beta2
agonist treatment. CONCLUSION: These studies demonstrate that inhalation of short
acting beta2 agonist treatment decrease dyspnea, but increase perception of
dyspnea induced by a resistive load in patients with asthma, and the mechanism of
the increased perception may not be related to the increased airflow rate. It may
be due to some local or central effects of bronchodilator drug on perception of
asthma.
PMID- 10674570
TI - Hypersensitivity pneumonitis resulting from community exposure to Canada goose
droppings: when an external environmental antigen becomes an indoor environmental
antigen.
AB - BACKGROUND: In the past, hypersensitivity pneumonitis has been attributed to
occupational, agricultural, or home environmental exposure. OBJECTIVE: This
report describes the first case of hypersensitivity pneumonitis due to community
exposure to droppings from Canada geese migrating through a suburban environment.
METHOD: Clinical and serologic information was used in making the diagnosis of
hypersensitivity pneumonitis. RESULTS: Serologic analysis demonstrated
precipitating antibodies against goose droppings and against an extract made from
washings from a filter taken from the patient's office. These studies also showed
that the antigens in the office filter were goose dropping antigens. CONCLUSION:
Hypersensitivity pneumonitis can result from exposure to goose dropping antigens
in the community that enter buildings through ventilation systems. This
represents a new form of an old disease.
PMID- 10674571
TI - Cross-reactivity among conifer pollens.
AB - BACKGROUND: There are increasing reports of Cupressaceae pollinosis from various
geographic areas. Cross-reactivity among a limited number of species within the
Cupressaceae family has been suggested. Juniperus ashei (mountain cedar) is the
leading cause of respiratory allergy in South Texas. OBJECTIVE: This study
examines in vivo and in vitro cross-reactivity among 12 Cupressaceae species, one
Taxodiaceae species, one Pinaceae species, and an angiosperm. METHODS: Cross
reactivity among pollen extracts of mountain cedar (MC) and the other 14 trees
was investigated by: (1) prick skin testing of each tree pollen extract in ten
patients with MC pollinosis. (2) Ouchterlony gel immunodiffusion employing rabbit
antisera to MC. (3) IgE immunoblotting using high-titer MC pooled human sera, and
immunoblot inhibition after pre-incubation with MC protein. (4) Monoclonal
antibody immunoblotting using a murine monoclonal antibody with strong affinity
for the gp40 major allergen of MC. RESULTS: Positive skin wheal-and-flare
responses occurred to all 12 Cupressaceae and Japanese cedar (the Taxodiaceae),
but not to the Pinaceae or the angiosperm. In Ouchterlony gels, lines of identity
or partial identity formed between MC and all pollens except the Pinaceae and the
angiosperm. Immunoblots demonstrated IgE binding to the 40 to 42 kD protein in
each Cupressaceae, and to a parallel band in Japanese cedar at 43 to 46 kD.
Immunoblot inhibition by MC pollen was complete for all trees. The monoclonal
bound both the 40 to 42 kD protein in 11 of 12 Cupressaceae species and the 46 kD
band in Japanese cedar, but bound no protein bands in the Pinaceae or the
angiosperm. CONCLUSION: Pollen proteins of the 12 Cupressaceae (including MC) and
the Taxodiaceae (Japanese cedar) are extensively cross-reactive. In particular,
the MC major allergen, gp40, is cross-reactive with 40 to 42 kD proteins of the
other Cupressaceae and with the Japanese cedar major allergen of 46 kD. Component
based immunotherapy may someday allow a standard treatment for both Juniper
allergic and C. japonica-allergic patients.
PMID- 10674572
TI - Asthma inhaler use and barriers in a population-based sample of African-American
and white adolescents.
AB - BACKGROUND: There is little information on inhaler medication and barriers to use
among a population-based sample of adolescents and whether possible variations in
asthma treatment by ethnic group exist. OBJECTIVE: We describe the prevalence of
inhaler use and identify barriers for proper use of asthma medication in a
population-based sample of adolescents of which 34% are African-American.
METHODS: A cross-sectional survey using the ISAAC (International Survey of Asthma
and Allergies in Children) questionnaire was conducted in a school population
based sample (n = 2056) of 13 to 14-year-old eight grade students in the
Charlotte-Mecklenburg, North Carolina public school system. Questions were asked
about symptom prevalence, asthma diagnosis, inhaler use, and barriers to care.
RESULTS: Fourteen percent of the children (296/2056) reported using an inhaler in
the last 12 months with no differences among African-American children and white
children. Twenty-six percent of inhaler users were not allowed to carry their
medication on their person while at school. Girls were more likely to be allowed
to carry their inhalers at school and diagnosed asthmatic girls had a higher
prevalence of wheezing in the last year (47%) compared with diagnosed asthmatic
boys (35%). Smoking prevalence was higher in inhaler users (26%) compared to the
study population (19%). CONCLUSIONS: Inhaler use is high in this population.
Adolescents using inhalers need to reduce their smoking levels. Schools need to
reevaluate their policies on the use of inhalers at school.
PMID- 10674573
TI - Atopy is a risk factor for non-steroidal anti-inflammatory drug sensitivity.
AB - BACKGROUND: There is scarce information in the literature about a possible
association between atopy and certain clinical manifestations of NSAID
sensitivity. OBJECTIVES: (1) To evaluate the prevalence of atopy in patients
proved to be sensitive to cyclooxygenase inhibitors. (2) To assess cross
reactivity to two alternative NSAIDs, paracetamol (acetaminophen) and nimesulide.
METHODS: NSAID-sensitive patients attending an allergy clinic and unselected
controls were prick tested with inhalant allergens. Oral challenges with NSAIDs
were carried out by the single-blinded (SBOC) method. Clinical data about
personal and family history of allergic and atopic diseases were obtained by a
careful review of the medical records and by direct questioning by experienced
allergists. RESULTS: Fifty patients had positive SBOCs to the suspected NSAID and
only these were studied. A personal history of atopic diseases was present in 41
patients (82%) and 7 controls (14.5%), and a family history in 24 patients (48%)
and 6 controls (12.5%). Prick skin tests with aeroallergens were positive in 39
of 45 patients tested (86.6%) and in 14 of 48 controls (29.1%), (P = .0001). Skin
test positivity rates were higher in patients with cutaneous challenge reactions
who responded to only one NSAID (single reactors) in comparison to cross-reactors
(P = .04). The most frequent clinical manifestations of NSAID sensitivity were
(1) cutaneous (angioedema, urticaria) in 34 patients, (2) blended (cutaneous plus
respiratory) in 12, (3) respiratory in 3, and (4) anaphylactoid in 1. Aspirin,
pyrazolone, paracetamol, and ibuprofen were the drugs more frequently implicated
in these reactions. Cross-sensitivity with paracetamol and nimesulide were 32%
and 25%, respectively. CONCLUSIONS: The prevalence of atopy is increased in
challenge-proven NSAID-intolerant patients. The atopic condition may represent an
important risk factor for developing reactions to these drugs. Paracetamol and
nimesulide are relatively safe alternative choices in those patients, although
their use still carries some risk of unwanted reactions.
PMID- 10674574
TI - Adherence to antiretroviral therapy by pregnant women infected with human
immunodeficiency virus: a pharmacy claims-based analysis.
AB - OBJECTIVE: To assess adherence to antiretroviral therapy with the use of Medicaid
pharmacy claims data for human immunodeficiency virus (HIV)-infected pregnant
women and to identify associated maternal and health care factors. METHODS: We
retrospectively studied a cohort of 2714 HIV-infected women in New York State who
delivered live infants from 1993-96. Among 682 women prescribed antiretroviral
therapy in the last two trimesters, we studied 549 who started therapy more than
2 months before delivery. Adherence was defined as adequate if the supplied drug
covered at least 80% of the days from the first prescription in the last two
trimesters until delivery. Multivariable analyses were used to examine
associations between maternal and health care factors and adherence. RESULTS:
Only 34.2% of 549 subjects had at least 80% adherence based on pharmacy data, a
rate that remained stable over time. The adjusted odds ratios (ORs) of adherence
for black (OR 0.47, 95% confidence interval [CI] 0.30, 0.75) and Hispanic (OR
0.49, 95% CI 0.29, 0.82) women were nearly 50% lower than for white women. The OR
of adherence was 0.32 (95% CI 0.12, 0.90) for teenagers compared with women aged
25-29 years and 0.56 (95% CI 0.34, 0.92) for women in New York City versus those
residing elsewhere. Women on antiretroviral therapy before pregnancy were more
likely to adhere (OR 1.55, 95% CI 1.02, 2.35). CONCLUSION: Teenagers, women of
minority groups, and women living in New York City had greater risks of poor
antiretroviral adherence, whereas women already prescribed antiretrovirals before
pregnancy had better adherence. Our conservative pharmacy data-based measure
showed that most HIV-infected women adhered poorly and adherence did not improve
over the 4-year study.
PMID- 10674575
TI - Respiratory distress syndrome and maternal birth weight effects.
AB - OBJECTIVE: To study traditional risk factors and the intergenerational risk
factor maternal low birth weight (LBW) for respiratory distress syndrome (RDS) in
infants in multiple ethnic groups. METHODS: The population-based database
consists of hospital records linked to Washington state maternal and infant vital
records. Four racial-ethnic groups were studied, whites, blacks, Native
Americans, and Hispanics. Poisson regression models were used to estimate
relative risks of various factors for RDS. RESULTS: Rates for RDS were whites
1.2%, blacks 1.9%, Native Americans 1.3%, and Hispanics 1.0%. Maternal LBW was
associated with increased relative risk (RR) for RDS in whites (2.6, 95%
confidence interval [CI] 1.6, 4.2) and blacks (3.3, 95% CI 1.9, 5.6) for infants
born vaginally. Compared with mothers of normal infants, birth weights of mothers
of infants with RDS and delivered vaginally were significantly lower in whites,
blacks, and Native Americans. The association of maternal LBW with RDS persisted
in blacks even when multiple risk factors were added to the model (RR 2.4; 95% CI
1.1, 5.1). CONCLUSION: The association of maternal LBW with RDS is probably due
in part to the association of maternal LBW with infant LBW and preterm birth. The
strong persistent association of maternal LBW with RDS in blacks suggests that
improvement of perinatal outcomes in that group will require improvement of long
term birth weight distribution.
PMID- 10674576
TI - Plasma thiol status in preeclampsia.
AB - OBJECTIVE: To measure plasma thiol levels in women with normal pregnancies, women
with preeclampsia, and nonpregnant controls to define plasma thiol's effect on
glutathione homeostasis and pathophysiology of preeclampsia. METHODS: Total
plasma cysteine, gamma-glutamylcysteine, homocysteine, cysteinylglycine, and
glutathione levels were measured in ten nonpregnant women, ten women with
normotensive pregnancies, and 20 women with preeclampsia at delivery. RESULTS:
Median total plasma levels of all thiols in normotensive pregnant women were
significantly lower than in nonpregnant women. Median total plasma cysteine and
homocysteine levels in women with preeclampsia were significantly higher compared
with pregnant controls (254 versus 190 micromol/L, P < .001; and 13.3 versus 8.4
micromol/L, P < .02, respectively), whereas glutathione levels were significantly
lower in women with preeclampsia compared with those in pregnant controls (5.1
versus 6.3 micromol/L, P < .05). CONCLUSION: In women with preeclampsia,
homocysteine and cysteine levels, which are lowered in normotensive pregnancy,
were comparable to levels in nonpregnant women, whereas glutathione levels were
lower. Those results suggest that in women with preeclampsia, glutathione use is
higher or its synthesis is disturbed. Therefore, glutathione might affect
pathophysiology of preeclampsia.
PMID- 10674577
TI - Serum insulin-like growth factor binding protein-1 at 16 weeks and subsequent
preeclampsia.
AB - OBJECTIVE: To determine whether serum concentrations of insulin-like growth
factor-binding protein-1 (IGFBP-1), a major decidual protein, at 16 weeks'
gestation differ between women who later develop pregnancy-related hypertension
and normotensive women. METHODS: Concentrations of IGFBP-1 were measured using
immunoenzymometric assay in serum samples collected for alpha-fetoprotein (AFP)
and free beta subunit of hCG (free beta-hCG) determinations in a Down syndrome
screening program at 16 weeks' gestation in a population-based cohort of 1049
nulliparous women. After exclusion of subjects with multiple pregnancies, insulin
dependent diabetes, major fetal malformations, and incomplete data, 917 subjects
remained eligible. RESULTS: The mean levels (+/- standard deviation) of IGFBP-1
were significantly lower in 34 women who later developed preeclampsia (73 +/- 43
microg/L, P < .01) and in 80 women with White A diabetes (84.7 +/- 53 microg/L, P
< .01) compared with controls (103 +/- 58 microg/L). In seven women with White A
diabetes and subsequent preeclampsia IGFBP-1 levels were especially low (41 +/-
34 microg/L). The concentrations of AFP and free beta-hCG in the subgroups with
hypertensive disorders were not significantly different from those of
normotensive women. CONCLUSION: Decreased IGFBP-1 levels at 16 weeks' gestation
in women who develop preeclampsia might indicate impaired decidual function.
Hyperinsulinemia, a known risk factor for preeclampsia, might contribute to
decreased concentrations of serum IGFBP-1. However, due to low sensitivity, assay
of serum IGFBP-1 was not clinically valuable for predicting preeclampsia.
PMID- 10674578
TI - Glycemic control throughout pregnancy and fetal growth in insulin-dependent
diabetes.
AB - OBJECTIVE: To determine the time of growth acceleration in fetuses of insulin
dependent diabetic women who are large for gestational age (LGA) at birth and the
relationship between growth acceleration and diabetic control throughout
pregnancy. METHODS: We studied a consecutive sample of 76 women with insulin
dependent diabetes divided by those who delivered LGA or normally grown infants.
Fetal abdominal circumference (AC) was measured ultrasonically at regular
intervals between 20 and 34 weeks' gestation. Diabetic control was assessed by
regular measurement of glycosylated hemoglobin and capillary blood glucose
levels. RESULTS: A significant difference in fetal AC between groups developed
between 20 and 24 weeks' gestation, and the LGA group continued to have
accelerated fetal growth. Between 18 and 24 weeks glycosylated hemoglobin and
capillary blood glucose concentrations were significantly higher in women who
delivered LGA infants. After 28 weeks, blood glucose concentrations and
glycosylated hemoglobin did not differ significantly between groups. There was a
nonsignificant trend toward more vaginal deliveries in the normal group (45%
versus 32%). CONCLUSION: In insulin-dependent diabetic pregnancy, although actual
growth acceleration occurred from about 20 weeks' gestation, growth potential of
fetuses appeared to be determined by prevailing maternal glucose concentrations
before then. Excessive growth continued despite subsequent satisfactory glucose
control. If strict blood glucose control is maintained during first and second
trimesters, it might reduce the incidence of LGA infants.
PMID- 10674579
TI - Fetal pancreatic function in infants of diabetic and rhesus-isoimmunized women.
AB - OBJECTIVE: To measure insulin and glucagon concentrations in amniotic fluid (AF)
collected near term in basal conditions and after an arginine test in diabetic,
rhesus-isoimmunized, and control pregnant women. METHODS: At baseline, AF was
collected from 44 diabetic, 32 rhesus-isoimmunized, and 27 control pregnant women
in late pregnancy. Fifty-two diabetic, six rhesus-isoimmunized, and nine control
pregnant women had amniocentesis 2 hours after arginine infusion (30 g
intravenous/30 minutes) at 33-36 weeks. RESULTS: Baseline AF glucose
concentrations were significantly greater in diabetic women than the other
conditions, and they related to the gestational age in the women with hemolytic
disease of the newborn. Insulin and glucagon AF content of isoimmunized
pregnancies overlapped controls, whereas insulin and insulin/glucagon molar
ratios were significantly higher, and glucagon values lower, in diabetic
pregnancies compared with isoimmunized and control pregnancies. In isoimmunized
pregnancies, the AF concentrations of glucose, insulin, and glucagon were
correlated with gestational age (less than 34, 34 weeks or more). The samples
collected after arginine infusion, compared with those collected at baseline,
showed significantly greater insulin and insulin/glucagon molar ratio values in
diabetic (28 +/- 5 versus 11 +/- 1 microU/mL, P = .001; 29.4 +/- 1.7 versus 12.0
+/- 2.8, P = .001) and in Rh pregnant women (18 +/- 6 versus 7.7 +/- 0.7
microU/mL, P = .001; 30 +/- 9 versus 3.4 +/- 0.4 I/G, P = .001), whereas no
significant difference was observed in the controls. CONCLUSION: Basal islet
hormone concentrations in AF are modified by maternal diabetes and further
influenced by arginine administration. Arginine produces an AF response that is
similar in pregnancies complicated by diabetes mellitus and rhesus
isoimmunization, despite different (hyperglycemia and euglycemia) maternal blood
glucose levels.
PMID- 10674580
TI - The appropriateness of recommendations for hysterectomy.
AB - OBJECTIVE: To evaluate the appropriateness of recommendations for hysterectomies
done for nonemergency and non-oncologic indications. METHODS: We assessed the
appropriateness of recommendations for hysterectomy for 497 women who had the
operation between August 1993 and July 1995 in one of nine capitated medical
groups in Southern California. Appropriateness was assessed using two sets of
criteria, the first developed by a multispecialty expert physician panel using
the RAND/University of California-Los Angeles appropriateness method, and the
second consisting of the ACOG criteria sets for hysterectomies. The main outcome
measure was the appropriateness of recommendation for hysterectomy, based on
expert panel ratings and ACOG criteria sets. RESULTS: The most common indications
for hysterectomy were leiomyomata (60% of hysterectomies), pelvic relaxation
(11%), pain (9%), and bleeding (8%). Three hundred sixty-seven (70%) of the
hysterectomies did not meet the level of care recommended by the expert panel and
were judged to be recommended inappropriately. ACOG criteria sets were applicable
to 71 women, and 54 (76%) did not meet ACOG criteria for hysterectomy. The most
common reasons recommendations for hysterectomies considered inappropriate were
lack of adequate diagnostic evaluation and failure to try alternative treatments
before hysterectomy. CONCLUSION: Hysterectomy is often recommended for
indications judged inappropriate. Patients and physicians should work together to
ensure that proper diagnostic evaluation has been done and appropriate treatments
considered before hysterectomy is recommended.
PMID- 10674581
TI - Cost-effectiveness of deep venous thrombosis prophylaxis in gynecologic oncology
surgery.
AB - OBJECTIVE: To estimate the cost-effectiveness of preventive strategies for deep
vein thrombosis (DVT) in patients undergoing surgery for gynecologic cancer.
METHODS: A model was constructed to estimate the costs and outcomes associated
with the use of external pneumatic compression, unfractionated heparin, and low
molecular weight heparin in women with cervical, endometrial, and ovarian cancer.
We estimated cost per DVT prevented, per fatal pulmonary embolus (PE) prevented,
and per life-year saved. Probability estimates for various outcomes and
efficacies were obtained from the literature, using data specific for gynecologic
patients when available. RESULTS: Cost-effectiveness estimates ranged from $27
per life-year saved for a 55-year-old endometrial cancer patient to $5132 per
life-year saved for a 65-year-old with ovarian cancer. Although low molecular
weight heparin and unfractionated heparin were cost-effective compared with no
prophylaxis, each was less effective than external pneumatic compression in the
base case. The results of the analysis were sensitive to assumptions about the
relative risk of DVT, the life expectancy of the patient, the costs of future
treatment, and the relative effectiveness of the different strategies: If
unfractionated heparin or low molecular weight heparin is at least 2-3% more
effective than external pneumatic compression, then the incremental cost per life
year of either would be less than $50,000 compared with external pneumatic
compression. CONCLUSION: Prophylaxis of DVT is cost-effective in terms of life
years gained even for patients with relatively short life expectancies, such as
ovarian cancer patients. External pneumatic compression appears to be the most
cost-effective strategy under our baseline assumptions, but further studies in
gynecologic cancer are needed to validate our conclusions.
PMID- 10674582
TI - Determinants of unexplained antepartum fetal deaths.
AB - OBJECTIVE: To assess fetal, maternal, and pregnancy-related determinants of
unexplained antepartum fetal death. METHODS: We conducted a hospital-based cohort
study of 84,294 births weighing 500 g or more from 1961-1974 and 1978-1996.
Unexplained fetal deaths were defined as fetal deaths occurring before labor
without evidence of significant fetal, maternal, or placental pathology. RESULTS:
One hundred ninety-six unexplained antepartum fetal deaths accounted for 27.2% of
721 total fetal deaths. Two thirds of the unexplained fetal deaths occurred after
35 weeks' gestation. The following factors were independently associated with
unexplained fetal death: maternal prepregnancy weight greater than 68 kg
(adjusted odds ratio [OR] 2.9; 95% confidence interval [CI] 1.85, 4.68), birth
weight ratio (defined as ratio of birth weight to mean weight for gestational
age) between 0.75 and 0.85 (OR 2.77; 95% CI 1.48, 5.18) or over 1.15 (OR 2.36;
95% CI 1.26, 4.44), fewer than four antenatal visits in women whose fetuses died
at 37 weeks or later (OR 2.21; 95% CI 1.08, 4.52), primiparity (OR 1.74; 95% CI
1.26, 2.40), parity of three or more (OR 2.01; 95% CI 1.26, 3.20), low
socioeconomic status (OR 1.59; 95% CI 1.14, 2.22), cord loops (OR 1.75; 95% CI
1.04, 2.97) and, for the 1978-1996 period only, maternal age 40 years or more (OR
3.69; 95% CI 1.28, 10.58). Trimester of first antenatal visit, low maternal
weight, postdate pregnancy, fetal-to-placental weight ratio, fetal sex, previous
fetal death, previous abortion, cigarette smoking, and alcohol use were not
significantly associated with unexplained fetal death. CONCLUSION: In this study,
we identified several factors associated with an increased risk of unexplained
fetal death.
PMID- 10674583
TI - Second-trimester cervical ultrasound: associations with increased risk for
recurrent early spontaneous delivery.
AB - OBJECTIVE: To determine whether short cervical length or internal os funneling
before 20 weeks' gestation predicts early preterm birth or pregnancy loss in
women with at least one prior spontaneous early preterm birth. METHODS:
Transvaginal cervical ultrasound examinations were done every 2 weeks on 69 women
with singleton gestations and histories of at least one prior spontaneous birth
between 16 and 30 weeks' gestation. The results of those examinations were
correlated with gestational age at delivery. RESULTS: Among 53 women who had
ultrasound examinations before 20 weeks' gestation, those with cervical lengths
at or below the tenth percentile for the study population (22 mm, n = 4) or
funneling of the internal os (n = 5) were more likely than women without those
factors to have spontaneous preterm births within 2 weeks (33% versus 0%, P =
.01) or 4 weeks from the ultrasound examination (67% versus 0%, P < .001) or
before 35 weeks' gestation (100% versus 19%, P < .001). Short cervical length or
funneling between 20-24 and 25-29 weeks was also associated with increased risk
of spontaneous preterm birth before 35 weeks' gestation (P < or = .05 and P =
.002, respectively) but not with increased risk of spontaneous preterm birth
within 2 or 4 weeks of ultrasound examination. CONCLUSION: Women with prior early
spontaneous preterm births who have short cervical lengths or funneling of the
internal cervical os before 20 weeks' gestation are at increased risk of
subsequent spontaneous preterm birth.
PMID- 10674584
TI - Progesterone, inhibin, and hCG multiple marker strategy to differentiate viable
from nonviable pregnancies.
AB - OBJECTIVE: To determine whether a combination of serum and urine biomarkers drawn
from symptomatic pregnant women will help early differentiation of viable from
nonviable pregnancies. METHODS: We conducted a prospective cohort study of 220
women who presented in the first trimester of pregnancy with complaints of pain,
cramping, bleeding, or spotting. Serum samples for progesterone, inhibin A, and
hCG, and urine beta-core hCG, were collected at presentation. To evaluate whether
those biomarkers could predict viable and nonviable outcomes in pregnancy, we
used likelihood ratios to compare operating characteristics of single and
multiple biomarker strategies. RESULTS: Of 220 pregnancies studied, 98 were
viable and 122 nonviable. Among single biomarkers, progesterone alone appears to
have the greatest utility (area under the receiver operator characteristic curve
= 0.923). Among dual-biomarker strategies, progesterone plus hCG and progesterone
plus inhibin A improved specificity but not sensitivity. At 95% sensitivity, the
combination of progesterone and hCG improved specificity from 0.29 to 0.66
(improvement = 0.37 [95% confidence interval 0.23, 0.52]). A triple-biomarker
combination did not show substantial improvement over the dual-biomarker
strategy. Also, combinations that used urine beta-core hCG did not improve
diagnostic accuracy. CONCLUSION: Serum progesterone appeared to be the single
most specific biomarker for distinguishing viable from nonviable pregnancies.
When a dual-biomarker strategy was applied, combining serum progesterone with
hCG, specificity improved significantly, which suggests that a multiple biomarker
strategy might help distinguish viable from nonviable pregnancies in early
gestation.
PMID- 10674585
TI - Misoprostol's effect on uterine arterial blood flow and fetal heart rate in early
pregnancy.
AB - OBJECTIVE: To determine whether a single oral dose of misoprostol is associated
with change in Doppler resistance indices (RIs) of the uterine artery in early
pregnancy. METHODS: Forty pregnant women seeking legal termination of pregnancy
at 7-15 completed gestational weeks were each given a single oral dose of 200
microg misoprostol. Resistance indices (A/B ratio) and pulsatility index (PI) of
the uterine arteries (UA) and fetal heart rate (FHR) were assessed by Doppler
ultrasound before and 1 hour after administration of misoprostol. RESULTS:
Doppler RIs (UA-A/B and UA-PI) of the right and left uterine arteries increased
significantly 1 hour after misoprostol administration. The right UA-A/B increased
from 7.16 +/- 1.09 (mean +/- SEM) to 10.26 +/- 0.67 (P < .001), and the left UA
A/B increased from 7.40 +/- 0.72 to 9.21 +/- 0.82 (P = .04). The right UA-PI
increased from 2.38 +/- 0.11 to 2.90 +/- 0.12 (P < .001), and the left UA-PI
increased from 2.38 +/- 0.17 to 2.70 +/- 0.18 (P = .03). No significant changes
in FHR were noted 1 hour after misoprostol administration. None of the fetuses
died during that time. CONCLUSION: Doppler RIs of the uterine arteries increased
significantly after single oral doses of misoprostol during the first trimester,
implying a reduction in arterial blood flow. Those changes were not associated
with fetal death, possibly explaining congenital abnormalities associated with
misoprostol in early pregnancy.
PMID- 10674586
TI - Coccidioidomycosis in pregnancy during an epidemic in California.
AB - OBJECTIVE: To determine presentation, clinical course, and outcome of a cohort of
pregnant women with coccidioidomycosis and compare findings with common
observations reported in the literature. METHODS: Thirty-two women who delivered
live infants or aborted fetuses in 1993 and had confirmed diagnoses of
coccidioidomycosis were included in the study. Medical records were evaluated
retrospectively for clinical characteristics, laboratory results, and disease
course. RESULTS: Dissemination occurred in three of 32 cases. The most common
management was supportive and symptomatic care. At 1 year, 26 of 32 had
recovered. There were no maternal deaths. CONCLUSION: The common depiction of
coccidioidomycosis in pregnancy has overstated morbidity and mortality likely
because of reporting bias. Many women will have favorable outcomes without drug
treatment, and the practice of abortions or early delivery in subjects with
active infection should be rare.
PMID- 10674587
TI - Amniochorion gelatinase-gelatinase inhibitor imbalance in vitro: a possible
infectious pathway to rupture.
AB - OBJECTIVE: To estimate the effect of lipopolysaccharide on gelatinases and tissue
inhibitors of matrix metalloproteinase 2 (gelatinase inhibitor) balance in human
fetal membranes. METHODS: Amniochorionic membranes in organ explant were
stimulated with 1000 ng/mL lipopolysaccharide for 24 hours after a 48-hour
preincubation period. Quantitative competitive polymerase chain reaction (PCR)
was done to quantitate messenger RNAs for gelatinase A and B (matrix
metalloproteinase 2 and 9) and tissue inhibitor of metalloproteinase 2. Protein
levels were assayed by enzyme-linked immunosorbant assay. The molar ratio between
gelatinases and tissue inhibitor of metalloproteinase 2 was calculated.
Statistical evaluation was done by Mann-Whitney U test. RESULTS:
Lipopolysaccharide stimulation produced 3.6 x 10(6) and 366 transcripts of
gelatinase A and B, respectively, compared with only 5.9 x 10(4) (P = .009) and
three transcripts (P = .006), respectively, in the controls. Lipopolysaccharide
stimulation released 210 ng/mL compared with 7 ng/mL of gelatinase A and B
proteins compared with 120 (P = .01) and 4.6 ng/mL (P = .3) in controls,
respectively. Control amniochorion produced 5.7 x 10(5) transcripts of tissue
inhibitor of metalloproteinase 2, whereas lipopolysaccharide stimulation produced
4.1 x 10(5) transcripts (P = .69). Lipopolysaccharide reduced the release of this
inhibitor from 114 ng/mL to 68 ng/mL (P = .007). The molar ratio between
gelatinases and tissue inhibitor of metalloproteinase 2 increased from a balanced
ratio of 1:1 to 3.1:1 after 1000 ng/mL of lipopolysaccharide. CONCLUSION:
Lipopolysaccharide increased the expression and release of gelatinases and
decreased its inhibitor, which shifted the balance in favor of gelatinase
activity leading to membrane degradation that predisposes to premature rupture of
membranes.
PMID- 10674588
TI - Diet and sex-hormone binding globulin, dysmenorrhea, and premenstrual symptoms.
AB - OBJECTIVE: To test the hypothesis that a low-fat, vegetarian diet reduces
dysmenorrhea and premenstrual symptoms by its effect on serum sex-hormone binding
globulin concentration and estrogen activity. METHODS: In a crossover design, 33
women followed a low-fat, vegetarian diet for two menstrual cycles. For two
additional cycles, they followed their customary diet while taking a supplement
placebo pill. Dietary intake, serum sex-hormone binding globulin concentration,
body weight, pain duration and intensity, and premenstrual symptoms were assessed
during each study phase. RESULTS: Mean (+/- standard deviation [SD]) serum sex
hormone binding globulin concentration was higher during the diet phase (46.7 +/-
23.6 nmol/L) than during the supplement phase (39.3 +/- 19.8 nmol/L, P < .001).
Mean (+/- SD) body weight was lower during the diet (66.1 +/- 11.3 kg) compared
with the supplement phase (67.9 +/- 12.1 kg, P < .001). Mean dysmenorrhea
duration fell significantly from baseline (3.9 +/- 1.7 days) to diet phase (2.7
+/- 1.9 days) compared with change from baseline to supplement phase (3.6 +/- 1.7
days, P < .01). Pain intensity fell significantly during the diet phase, compared
with baseline, for the worst, second-worst, and third-worst days, and mean
durations of premenstrual concentration, behavioral change, and water retention
symptoms were reduced significantly, compared with the supplement phase.
CONCLUSION: A low-fat vegetarian diet was associated with increased serum sex
hormone binding globulin concentration and reductions in body weight,
dysmenorrhea duration and intensity, and premenstrual symptom duration. The
symptom effects might be mediated by dietary influences on estrogen activity.
PMID- 10674589
TI - Menstrual blood loss measured 5-6 years after endometrial ablation.
AB - OBJECTIVE: To examine objectively the long-term efficacy of endometrial ablation
for menorrhagia. METHODS: Thirty-nine women with menorrhagia due to ovulatory
dysfunctional bleeding treated previously by rollerball ablation were followed up
5-6 years later. Menstrual blood in sanitary towels was measured with the
alkaline hematin technique in 26 women who were still premenopausal and in whom
menstrual blood loss had been measured before and immediately after the original
ablation. RESULTS: Mean (+/- standard deviation [SD]) menstrual blood loss (per
menstrual period) was reduced from 90 mL +/- 14.4 before ablation to 3.8 mL +/-
2.1 at 3 months, 1.8 mL +/- 1.0 at 6 months, and 3.3 mL +/- 1.3 at 5-6 years
after ablation. In women who were still menstruating, the mean hemoglobin
concentration rose significantly from 126 to 135 g/L (P = .022). CONCLUSION:
Rollerball endometrial ablation is a highly effective long-term therapy for
carefully selected women with menorrhagia due to ovulatory dysfunctional uterine
bleeding.
PMID- 10674590
TI - Cigarette smoking and epithelial ovarian cancer by histologic type.
AB - OBJECTIVE: To examine cigarette smoking as a risk factor for different types of
epithelial ovarian cancer. METHODS: We used data from the Cancer and Steroid
Hormone Study, a multicenter, population-based, case control investigation. Cases
were 447 women aged 20-54 years with diagnoses of epithelial ovarian cancer.
Controls were 3868 women selected by random-digit dialing. Conditional logistic
regression was used to obtain odds ratios (ORs) and 95% confidence intervals
(CIs) as estimators of the relative risk of ovarian cancer. With age and study
site as conditioning variables, OR point estimates were additionally adjusted for
parity and use of oral contraceptives. RESULTS: The OR of mucinous epithelial
ovarian cancer for women who had ever smoked was 2.3 (95% CI 1.4, 3.9) and for
current smokers was 2.9 (95% CI 1.7, 4.9). The OR of mucinous tumors for current
smokers was significantly elevated regardless of years since first cigarette or
age at which women first smoked. The OR of mucinous tumors for current smokers
increased slightly as cumulative pack-years of smoking increased, although the
trend was not significant. Similar patterns of elevated risk were not observed
among serous, endometrioid, or other histologic types. Odds ratio point estimates
for former smokers were not significantly elevated for any histologic type.
CONCLUSION: Current cigarette smoking was a risk factor for mucinous epithelial
ovarian cancer, but not other histologic types.
PMID- 10674591
TI - Hormone withdrawal symptoms in oral contraceptive users.
AB - OBJECTIVE: To measure the timing, frequency, and severity of hormone-related
symptoms in oral contraceptive (OC) users, specifically to compare active-pill
with hormone-free intervals. METHODS: Using daily diaries, women recorded pelvic
pain, bleeding, headaches, analgesic use, nausea or vomiting, bloating or
swelling, and breast tenderness during active-pill intervals and hormone-free
intervals. Participants either had no prior OC use, had taken OCs and were
restarting, or had been taking OCs continuously for 12 months or longer. RESULTS:
Two hundred sixty-two women, 26 with no previous OC use, 43 prior users, and 193
current users, provided daily records of hormone-related symptoms. Subjects with
no prior OC use and prior users restarting were similar in no recent OC use, and
because of the small sample, they were pooled for analysis as new-start OC users.
Current users had patterns of symptoms that were more frequent during hormone
free intervals than during the three active-pill weeks. These included pelvic
pain (70% versus 21%, P < .001), headaches (70% versus 53%, P < .001), use of
pain medication (69% versus 43%, P < .001), bloating or swelling (58% versus 19%,
P < .001), and breast tenderness (38% versus 16%, P < .001). Similar patterns
were seen in new-start OC users after the first cycle. Among new-start OC users,
menstrual flow patterns, headache, bloating or swelling, and breast-tenderness
symptoms decreased during the three cycles to approach those levels of current
users. CONCLUSION: Almost all symptoms assessed were significantly worse during
the 7-day hormone-free interval than during the 21 days of hormone-containing
pills.
PMID- 10674592
TI - Access to emergency contraception.
AB - OBJECTIVE: To evaluate access to emergency contraception among women seeking help
from clinicians who registered to be listed on the Emergency Contraception
Hotline (1-888-NOT-2-LATE, ie, 1-888-668-2528) and the Emergency Contraception
Website (not-2-late.com). METHODS: Two college-educated investigators posing as
women who had a condom break the previous night called 200 providers to seek
help. RESULTS: Only 76% of attempts resulted in an appointment or telephone
prescription from a hotline provider within 72 hours, 14% were failures, and 11%
resulted in referrals to other providers not listed on the hotline or website.
CONCLUSION: Even under ideal conditions, access to emergency contraception is
currently constrained. Although emergency contraception could reduce
significantly the incidence of unintended pregnancy and the consequent need for
abortion, its potential will not be realized unless women have better access to
clinicians who can prescribe emergency contraceptive pills.
PMID- 10674593
TI - Meclizine for prevention of nausea associated with use of emergency contraceptive
pills: a randomized trial.
AB - OBJECTIVE: We conducted a randomized trial to determine whether pretreatment with
meclizine reduces the incidence of nausea and vomiting associated with the Yuzpe
regimen of emergency contraception. METHODS: We randomly assigned 343 women aged
18-45 years who were not at risk for pregnancy to pretreatment with 50 mg of
meclizine, placebo, or no drug 1 hour before the first of two doses of emergency
contraceptive pills. We asked participants to complete three questionnaires over
the following 48 hours. RESULTS: The incidence of nausea was 47% in the group
pretreated with meclizine and 64% in the other two groups (relative risk adjusted
for center 0.7, 95% confidence intervals 0.6, 0.9 for comparisons of meclizine
with both placebo and no drug). The severity of nausea and the incidence of
vomiting were also significantly lower in the meclizine pretreatment group than
in the other two groups. Drowsiness was reported by about twice as many women in
the meclizine pretreatment group (31%) than in the other two groups (13% in the
placebo group, 16% in the no-pretreatment group; P < .01 for both comparisons).
CONCLUSION: Meclizine is effective for preventing nausea and vomiting associated
with the Yuzpe regimen of emergency contraceptive pills. Women using this drug
should be cautioned to anticipate drowsiness.
PMID- 10674594
TI - Estrogen effects on postural balance in postmenopausal women without vasomotor
symptoms: a randomized masked trial.
AB - OBJECTIVE: To assess whether estrogen treatment given to postmenopausal women
without vasomotor symptoms improves balance more than placebo. METHODS: Forty
healthy postmenopausal women without vasomotor symptoms were randomized to
transdermal 17beta-estradiol (E2) 50 microg/day for 14 weeks or identical
transdermal placebo patches. Postural balance was measured with dynamic
posturography before and after 4, 12, and 14 weeks of therapy. In this test, the
visual, vestibular, and somatosensory systems were provoked with increasing
difficulty and body sway was measured with a dual forceplate. A low score showed
large sway and a score of 100 showed no sway at all. RESULTS: Thirty-eight women
completed the study. Both groups had normal balance for their ages and near
maximum scores in the three easier balance tests at baseline. In the most
difficult test, both groups improved their postural balance significantly (from
13 to 32 and from 22 to 39, respectively) after 4 weeks. Thereafter, no change
was seen. One problem was low statistical power, but the relative change in
balance did not differ between groups. The comparison did not show even a minute
advantage of E2 over placebo, so a study with higher power would probably not
have shown a more pronounced effect of estrogen than placebo. The change over
time did not differ between groups, which indicates a significant learning
effect. CONCLUSION: In women without vasomotor symptoms, estrogen therapy did not
seem to increase postural balance significantly more than placebo. However, we
could not rule out that estrogens affect postural balance in women with vasomotor
symptoms.
PMID- 10674596
TI - The effect of transport on the rate of severe intraventricular hemorrhage in very
low birth weight infants.
AB - OBJECTIVE: To determine the incidence of grade III or IV intraventricular
hemorrhage in very low birth weight (VLBW) infants born at level I hospitals and
transported to one tertiary center compared with those delivered at the same
level III facility. METHODS: We evaluated all newborns admitted to a large
tertiary neonatal intensive care unit from June 1, 1992, through December 31,
1995. All live born infants with birth weights of 500-1200 g and at least 24
weeks' gestation were included. Neonatal transports within 24 hours of delivery
from 11 level I facilities were compared with those delivered at the same level
III center with respect to grade III and IV intraventricular hemorrhage. Various
antenatal and neonatal data were collected. RESULTS: Thirty-seven newborns (11%)
experienced grade III or IV intraventricular hemorrhages among 329 who met study
criteria. There were 27 cases (9%) in the 285 inborn neonates compared with 10 of
44 outborn cases (23%) (P < .02, 95% confidence interval 0.15, 0.87). The mean
gestational age of the neonates with grade III or IV intraventricular hemorrhages
was significantly lower in the inborn group, which further emphasizes the
finding. No other study factors explained the difference. CONCLUSION: We found a
higher risk for grade III or IV intraventricular hemorrhage developing in VLBW
infants born at level I hospitals and transported to the tertiary care center
compared with those born at the level III facility. This data should be
considered when analyzing the potential effects of perinatal deregionalization.
PMID- 10674595
TI - 17 Beta-estradiol-stimulated nitric oxide production by neutrophils: effect on
platelet activation.
AB - OBJECTIVE: To evaluate the effect of 17beta-estradiol (E2) on the ability of
human neutrophils to produce nitric oxide (NO) and its effects on platelet
activation. METHODS: The expression of neuronal nitric oxide synthase (nNOS)
protein and the formation of NO by 17beta-E2-incubated neutrophils from men were
studied in vitro (ten male volunteers, no medical-surgical antecedents, aged 25
45 years). Platelet aggregometry and changes in cyclic guanosine monophospate
(cGMP) levels were used to bioassay the functionality of NO released from
neutrophils. RESULTS: Incubation of neutrophils derived from men with physiologic
concentrations of 17beta-E2 (10(-10) to 10(-8) mol/L) enhanced the expression of
nNOS protein. 17Beta-E2-incubated neutrophils also showed a significant increase
in their ability to generate NO measured by the conversion of [3H]-L-arginine to
[3H]-L-citrulline. Furthermore, 17beta-E2-incubated neutrophils showed a greater
ability to prevent adenosine diphosphate (ADP)-induced platelet activation.
Moreover, increased levels of cGMP were found in the coincubation of platelets
with 17beta-E2-treated neutrophils. CONCLUSION: These results suggest that 17beta
E2 increases the ability of human neutrophils to produce NO and therefore may
contribute to cardiovascular disease protection.
PMID- 10674597
TI - Office prenatal formula advertising and its effect on breast-feeding patterns.
AB - OBJECTIVE: To compare the effect of formula company-produced materials about
infant feeding to breast-feeding promotion materials without formula advertising
on breast-feeding initiation and duration. METHODS: Five hundred forty-seven
pregnant women were randomized to receive either formula company (commercial; n =
277) or specially designed (research; n = 270) educational packs about infant
feeding at their first prenatal visit. Feeding method was determined at delivery.
Breast-feeding duration of the 294 women who chose to breast-feed was ascertained
at 2, 6, 12, and 24 weeks. Survival analyses were used to evaluate continuous
outcomes, and chi2 and logistic regression analyses were used to evaluate
discrete outcomes. RESULTS: Breast-feeding initiation (relative risk [RR] 0.93,
95% confidence interval [CI] 0.61, 1.43) and duration after 2 weeks (hazard ratio
1.19, 95% CI 0.86, 1.64) were not affected. Women in the commercial group were
more likely to cease breast-feeding before hospital discharge (RR 5.80, 95% CI
1.25, 54.01) and before 2 weeks (adjusted odds ratio [OR] 1.91, 95% CI 1.02,
3.55). In subgroup analyses, women with uncertain goals for breast-feeding or
goals of 12 weeks or less experienced shortened exclusive (hazard ratio 1.53, 95%
CI 1.06, 2.21), full (hazard ratio 1.70, 95% CI 1.18, 2.48), and overall (hazard
ratio 1.75, 95% CI 1.16, 2.64) breast-feeding duration when exposed to the
commercial intervention. CONCLUSION: Although breast-feeding initiation and long
term duration were not affected, exposure to formula promotion materials
increased significantly breast-feeding cessation in the first 2 weeks.
Additionally, among women with uncertain goals or breast-feeding goals of 12
weeks or less, exclusive, full, and overall breast-feeding duration were
shortened. Educational materials about infant feeding should support
unequivocally breast-feeding as optimal nutrition for infants; formula promotion
products should be eliminated from prenatal settings.
PMID- 10674598
TI - Endobag extractor to remove masses during laparoscopy.
AB - BACKGROUND: Intra-abdominal masses are removed during laparoscopy using different
types of endobags. However, in many cases the specimens are larger than the
trocar or the incision in the abdomen, with a potential risk of endobag rupture.
INSTRUMENT: We developed an instrument to facilitate extraction of an endobag
during laparoscopy without the need for a conventional minilaparotomy. The
endobag extractor has three removable diverging blades that symmetrically enlarge
the operative canal in the abdominal wall if spread after sharp extension of the
skin incision. The full endobag can be drawn through the canal without the risk
of endobag rupture because the size of the canal can be individualized, building
a funnel. EXPERIENCE: We removed various kinds of ovarian tumors, specimens from
salpingo-oophorectomies, and other specimens in 22 cases. CONCLUSION: This new
instrument allows easy removal of surgical specimens during laparoscopy without
conventional minilaparotomy, regardless of the type of endobag used. We believe
this instrument lessens the risk of endobag rupture.
PMID- 10674599
TI - Computed tomography-guided pudendal block for treatment of pelvic pain due to
pudendal neuropathy.
AB - BACKGROUND: Severe pelvic pain secondary to pudendal neuropathy can be treated
with repeated local anesthetic nerve blocks or with surgical decompression of the
nerve. Computed tomographic (CT) needle guidance to identified reliable anatomic
points might be useful for improved success rates. TECHNIQUE: A CT scan is used
to determine baseline anatomy and identify the sacrospinous process. A metallic
marker is used to create a perpendicular pathway from the sacrospinous process
upward to the skin surface, where a local anesthetic is injected. A 22-gauge, 5
inch needle is inserted downward in a perpendicular direction to the target. Deep
penetration and direction are confirmed by serial CT scans. Medication is
injected and the needle is removed. EXPERIENCE: Twenty-six women with diagnoses
of pudendal neuropathy were treated with injection therapy once per month, for
five total treatments each. About three-quarters experienced improvement. There
were no complications in this series. Outcomes were gratifying considering the
complex patient population, all having failed multiple therapeutic trials.
CONCLUSION: We believe this technique warrants further evaluation and application
in instances where noninvasive therapy of pudendal neuropathy is indicated.
PMID- 10674600
TI - An interactive web site for research on fetal heart rate monitoring.
AB - BACKGROUND: Traditional methods of exchange of research information may not be
rapid enough, especially for international multicenter studies or when discussing
controversial issues such as the value of fetal monitoring. The Internet is a
useful tool that provides numerous opportunities for immediate communication
within a large and diverse community of researchers. METHOD: A Web site at
http://www.sisporto.med.up.pt was developed for a multicenter research project
with interlinked pages on automated fetal heart rate (FHR) monitoring. It
includes background knowledge about the subject, detailed information about the
project, and a few interactive pages. These pages allow online discussions,
simulations of data analysis, and download of data for local FHR analysis.
EXPERIENCE: The Web site has been accessed from all over the world. In
particular, participating research centers have had easy and fast access to
background project information, and a few other clinicians and researchers
participated in our online discussions and used the simulation tools or the data
provided for analysis of typical FHR patterns. CONCLUSION: Web sites can be
useful in multicenter research projects and for scientific information exchange.
PMID- 10674601
TI - Workforce projections for subspecialists in obstetrics and gynecology.
AB - OBJECTIVE: To project the future supply of practicing subspecialists in
obstetrics and gynecology based on the most recent numbers of physicians entering
fellowships. METHODS: A discrete actuarial model was developed, and supply
projections were examined using 1999 subspecialty fellowship numbers from the
American Board of Obstetrics and Gynecology. RESULTS: The numbers of obstetrician
gynecologists entering subspecialty fellowships in maternal-fetal medicine (MFM)
and reproductive endocrinology-infertility (REI) declined sharply between 1994
and 1999. There was a slow increase in gynecologic oncology (GO) fellows.
Projections show that the numbers of practicing MFM and GO subspecialists will
double by 2020, but they will be serving a 20% larger female population in the
United States. Numbers of practicing REI subspecialists will increase slowly.
CONCLUSION: The number of fellows in GO continues to enlarge progressively though
slightly, whereas those in MFM and REI have fallen sharply in recent years. Among
four possible factors affecting growth or decline, the ones that seem most
important are existing career opportunities for both generalist and subspecialist
obstetrician-gynecologists and the length of subspecialty education.
PMID- 10674602
TI - Professionalism in obstetrics-gynecology residency education: the view of program
directors.
AB - OBJECTIVE: To define the qualities of professionalism emphasized in obstetrics
gynecology residencies and identify existing means of evaluating them. METHODS: A
survey, designed to assess the importance of professionalism in residency
programs and what means are utilized for its development, was sent to all 270
obstetrics-gynecology residency program directors in the United States. RESULTS:
Two hundred thirteen surveys were returned (79%). Ninety-seven percent of all
respondents indicated that they thought the development of professionalism was
necessary for training obstetrics-gynecology residents, and 84.3% thought that
formal educational training time should be devoted to this development. Over 85%
endorsed faculty examples and mentoring as their methods of teaching
professionalism. Respondents ranked honesty; accountability to patients,
colleagues, and society; respect for patients; integrity; and excellence as the
most important qualities of professionalism. Almost 79% believed those qualities
were as important and as necessary as qualities of skill and knowledge in
residency training. Almost 80% of respondents thought that the establishment of
formal professionalism guidelines would be valuable in their training programs.
CONCLUSION: A critical quality in resident education is professionalism, which
receives emphasis in training programs largely through faculty example and
mentoring. The variability inherent in such methods might be reduced by residency
wide guidelines for uniform application of standards and to avoid arbitrariness
in enforcement.
PMID- 10674603
TI - Medical and osteopathic boards' positions on chaperones during gynecologic
examinations.
PMID- 10674604
TI - Eradication of Helicobacter pylori prevents recurrence of ulcer after simple
closure of duodenal ulcer perforation: randomized controlled trial.
AB - OBJECTIVE: In this randomized trial, the authors sought to determine whether
eradication of Helicobacter pylori could reduce the risk of ulcer recurrence
after simple closure of perforated duodenal ulcer. BACKGROUND DATA: Immediate
acid-reduction surgery has been strongly advocated for perforated duodenal ulcers
because of the high incidence of ulcer relapse after simple patch repair.
Although H. pylori eradication is now the standard treatment of uncomplicated and
bleeding peptic ulcers, its role in perforation remains controversial. Recently a
high prevalence of H. pylori infection has been reported in patients with
perforations of duodenal ulcer. It is unclear whether eradication of the
bacterium confers prolonged ulcer remission after simple repair and hence
obviates the need for an immediate definitive operation. METHODS: Of 129 patients
with perforated duodenal ulcers, 104 (81%) were shown to be infected by H.
pylori. Ninety-nine H. pylori-positive patients were randomized to receive either
a course of quadruple anti-helicobacter therapy or a 4-week course of omeprazole
alone. Follow-up endoscopy was performed 8 weeks, 16 weeks (if the ulcer did not
heal at 8 weeks), and 1 year after hospital discharge for surveillance of ulcer
healing and determination of H. pylori status. The endpoints were initial ulcer
healing and ulcer relapse rate after 1 year. RESULTS: Fifty-one patients were
assigned to the anti-Helicobacter therapy and 48 to omeprazole alone. Nine
patients did not undergo the first follow-up endoscopy. Of the 90 patients who
did undergo follow-up endoscopy, 43 of the 44 patients in the anti-Helicobacter
group and 8 of the 46 in the omeprazole alone group had H. pylori eradicated;
initial ulcer healing rates were similar in the two groups (82% vs. 87%). After 1
year, ulcer relapse was significantly less common in patients treated with anti
Helicobacter therapy than in those who received omeprazole alone (4.8% vs.
38.1%). CONCLUSIONS: Eradication of H. pylori prevents ulcer recurrence in
patients with H. pylori-associated perforated duodenal ulcers. Immediate acid
reduction surgery in the presence of generalized peritonitis is unnecessary.
PMID- 10674605
TI - Redefining the role of surgery for perforated duodenal ulcer in the Helicobacter
pylori era.
PMID- 10674606
TI - Gastroesophageal reflux disease in asthma: effects of medical and surgical
antireflux therapy on asthma control.
AB - OBJECTIVE: To critique the English-language reports describing the effects of
medical and surgical antireflux therapy on respiratory symptoms and function in
patients with asthma. METHODS: The Medline computerized database (1959-1999) was
searched, and all publications relating to both asthma and gastroesophageal
reflux disease were retrieved. RESULTS: Seven of nine trials of histamine
receptor antagonists showed a treatment-related improvement in asthma symptoms,
with half of the patients benefiting. Only one study identified a beneficial
effect on objective measures of pulmonary function. Three of six trials of proton
pump inhibitors documented improvement in asthma symptoms with treatment; benefit
was seen in 25% of patients. Half of the studies reported improvement in
pulmonary function, but the effect occurred in fewer than 15% of patients. In the
one study that used optimal antisecretory therapy, asthma symptoms were improved
in 67% of patients and pulmonary function was improved in 20%. Combined data from
5 pediatric and 14 adult studies of anti-reflux surgery indicated that almost 90%
of children and 70% of adults had improvement in respiratory symptoms, with
approximately one third experiencing improvements in objective measures of
pulmonary function. CONCLUSIONS: Fundoplication has been consistently shown to
ameliorate reflux-induced asthma; results are superior to the published results
of antisecretory therapy. Optimal medical therapy may offer similar results, but
large studies providing support for this assertion are lacking.
PMID- 10674607
TI - Colon interposition for esophageal replacement: an alternative technique based on
the use of the right colon.
AB - OBJECTIVE: To describe the technique and results of an alternative colon
interposition procedure in which the ascending and transverse colon is used as
graft, but that still relies on the left colonic artery for blood supply. SUMMARY
BACKGROUND DATA: The standard procedure to obtain a left colon interposition
graft requires ligation of the middle colic artery and mobilization of the left
and right flexure. This approach carries a risk because preparation of the left
flexure may damage arterial or venous collaterals located at this site that are
crucial for graft perfusion. METHODS: The authors modified the standard technique
so that mobilization of the left flexure is no longer necessary. To obtain a
colon interposition graft that is long enough, the ascending colon was included
into the graft by ligating the middle and the right colic artery. The left colic
artery remained the blood-supplying vessel. From January 1997 to June 1998, 15
patients underwent modified colon interposition with a cervical anastomosis (12
esophagectomies, 3 esophagogastrectomies). RESULTS: In all cases, intraoperative
blood supply from the left colic artery to the proximal ascending colon was
sufficient. After surgery, four major complications occurred (27%). Endoscopy
demonstrated a vital graft in all patients. In one patient a leakage of the
cervical anastomosis was observed. One patient died of herpes pneumonia.
Postoperative artificial ventilation was required for an average of 2.8 +/- 4.6
days, the average intensive care unit stay was 6.9+/-4.5 days, and the average
total hospital stay was 24.1 +/- 15.1 days. CONCLUSION: An intact left colic
artery, including its collaterals at the splenic flexure, supplies sufficient
blood to the proximal ascending colon after central ligation of the middle and
right colic artery. Even without mobilization of the left flexure, a sufficient
graft length can be obtained. Preliminary complication rates with the use of this
technique for colon interposition are in the range of those found for the
standard colon interposition technique. These modifications may represent an
alternative to established procedures for creating a colon interposition graft.
PMID- 10674608
TI - Clinical significance of p53 mutations in adenocarcinoma of the esophagus and
cardia.
AB - OBJECTIVE: To compare the frequency and spectrum of p53 gene mutations in
adenocarcinomas of the esophagus and cardia and to compare clinical and
pathologic features in patients with p53 mutant and nonmutant cancers. SUMMARY
BACKGROUND DATA: The p53 gene is commonly mutated in human cancers, and a p53
mutation is reported to be present in more than 50% of esophageal
adenocarcinomas. Although many studies have investigated the frequency of p53
protein overexpression in adenocarcinomas of the esophagus or esophagogastric
junction, few studies have assessed the frequency and clinical significance of
p53 mutations in these tumors. In particular, the prognostic importance of p53
mutation is uncertain. Adenocarcinomas of the esophagus and cardia share many
epidemiologic and pathologic features, but it is controversial whether they
represent the same tumor. A comparison of the frequency and spectrum of mutations
in adenocarcinomas of the esophagus and cardia would test whether these tumors
are also similar at the molecular level. METHODS: DNA was isolated from
microdissected paraffin-embedded tumor tissues of patients who underwent
esophagogastrectomy for adenocarcinoma of the esophagus (n = 19), cardia
(esophagogastric junction, n = 12), or subcardia (n = 6). Exons 5 to 8 of the p53
gene were analyzed for the presence of mutations using the polymerase chain
reaction with single-strand conformation polymorphism and DNA sequencing of bands
showing abnormal mobility. The presence of mutation was confirmed by selective
hybridization of a mutant-specific oligonucleotide to DNA isolated from the
tumor. RESULTS: p53 mutations were identified in 18 of 37 (48.6%) tumors.
Patients with p53 mutant tumors were significantly younger and had a
significantly poorer prognosis. There was a similar prevalence of p53 mutations
in adenocarcinomas of the esophagus (53%) and cardia (58%). In contrast,
mutations were relatively uncommon in subcardia adenocarcinomas (one mutant tumor
[17%]). The types of mutations found in the esophageal and the cardia cancers
were also similar. CONCLUSIONS: Adenocarcinomas of the esophagus and cardia have
a similar frequency and spectrum of p53 gene mutations, suggesting that these
tumors have a common pathogenesis. Patients with mutations are younger, have
signs of more advanced disease, and have a poorer prognosis than patients without
mutations.
PMID- 10674609
TI - Prognostic factors in gastric stump carcinoma.
AB - OBJECTIVE: To compare prognostic results in patients with gastric stump cancer
(GSC) versus those with primary gastric cancer (PGC). SUMMARY BACKGROUND DATA:
Gastric stump carcinomas have often been described as having low resectability
rates and a poor prognosis. METHODS: Results of surgical treatment of 50 patients
with GSC were compared with that of 516 patients with PGC. RESULTS: The
resectability rate was 94% for GSC patients and 96.5% for PGC patients, without
significant differences in terms of postoperative complications, death rate, and
median survival time (31.6 vs. 32.9 months). The multivariate analysis showed an
independent prognostic effect for R0 resection, pT1 and pT2 category, and age
older than 65 years. CONCLUSION: The prognosis after resection and adequate
lymphadenectomy does not differ between patients with GSC and PGC.
PMID- 10674610
TI - Effect of intravascular volume expansion on renal function during prolonged CO2
pneumoperitoneum.
AB - OBJECTIVE: To evaluate whether intravascular volume expansion would improve renal
blood flow and function during prolonged CO2 pneumoperitoneum. SUMMARY BACKGROUND
DATA: Although laparoscopic living donor nephrectomies have a considerably
reduced risk of complications for the donors, significant concerns exist
regarding procurement of a kidney in the altered physiologic environment of CO2
pneumoperitoneum. Recent studies have documented adverse effects of CO2
pneumoperitoneum on renal hemodynamics. METHODS: Renal and systemic hemodynamics
and renal histology were studied in a porcine CO2 pneumoperitoneum model. After
placement of a pulmonary artery catheter, carotid arterial line, Foley catheter,
and renal artery ultrasonic flow probe, CO2 pneumoperitoneum (15 mmHg) was
maintained for 4 hours. Pigs were randomized into three intravascular fluid
protocol groups: euvolemic (3 mLkg/hour isotonic crystalloid), hypervolemic (15
mL/kg/hour isotonic crystalloid), or hypertonic (3 mL/kg/hour isotonic
crystalloid plus 1.2 mL/kg/hour 7.5% NaCl). RESULTS: In the euvolemic group,
prolonged CO2 pneumoperitoneum caused decreased renal blood flow, oliguria, and
impaired creatinine clearance. Both isotonic and hypertonic volume expansions
reversed the changes in renal blood flow and urine output, but impaired
creatinine clearance persisted. CONCLUSIONS: Intravascular volume expansion
alleviates the effects of CO2 pneumoperitoneum on renal hemodynamics in a porcine
model. Hypertonic saline (7.5% NaCl) solution may maximize renal blood flow in
prolonged pneumoperitoneum, but it does not completely prevent renal dysfunction
in this setting. This study suggests that routine intraoperative volume expansion
is important during laparoscopic live donor nephrectomy.
PMID- 10674611
TI - Stapled versus sutured closure of loop ileostomy: a randomized controlled trial.
AB - OBJECTIVE: To compare the outcome after conventional sutured loop ileostomy
closure with stapled ileostomy closure. SUMMARY BACKGROUND DATA: A defunctioning
loop ileostomy is now widely used in colorectal surgery. Subsequent closure may
be associated with early complications, particularly bowel obstruction. The
results of a preliminary nonrandomized study suggested that there was no
significant difference in the rate of complications between sutured and stapled
closure of loop ileostomy. METHODS: One hundred forty-one consecutive patients
who underwent loop ileostomy between 1993 and 1998 were randomized before surgery
to either sutured or stapled loop ileostomy closure. Seventy-one patients had
stapled closure and 70 had sutured closure. RESULTS: Both groups were comparable
in terms of age, sex, original operation, duration after original operation, and
level of operating surgeon. Postoperative bowel obstruction occurred in 10/70
(14%) patients after sutured closure compared with 2/71 (3%) patients after
stapled closure. Subgroup analysis of ileostomy closure in patients having an
ileal pouch showed no significant difference in bowel obstruction between stapled
and sutured closure (2/30 vs. 7/29). The incidence of other complications,
readmissions, and reoperations did not differ between the two groups. The stapled
closure was only 4 minutes quicker than sutured closure. The mean total hospital
stay tended to be shorter after the stapled closure than the sutured closure, but
this did not reach statistical significance. CONCLUSIONS: Bowel obstruction
occurred less frequently after stapled closure, but the mean hospital stay and
readmission and reoperation rate did not significantly differ between the two
groups.
PMID- 10674612
TI - Clinical and pathologic correlation of 84 mucinous cystic neoplasms of the
pancreas: can one reliably differentiate benign from malignant (or premalignant)
neoplasms?
AB - OBJECTIVE: To determine whether the long-term behavior of cystic mucinous
neoplasms of the pancreas could be predicted using a novel, precisely defined
classification of benign mucinous cystadenomas, noninvasive proliferative cystic
mucinous neoplasms, and invasive mucinous cystadenocarcinomas. The primary
interest was to obtain long-term follow-up after complete resection to determine
the recurrence rates based on this objective classification. BACKGROUND: Current
understanding is that all cystic mucinous neoplasms of the pancreas are
potentially malignant and that mucinous cystadenomas, when completely removed,
are biologically benign. Cystadenocarcinomas are thought to be less aggressively
malignant than ordinary ductal adenocarcinoma, but reported recurrence rates vary
widely and are unpredictable. METHODS: All patients who underwent "curative"
resection for cystic mucinous neoplasms at Mayo Clinic Rochester from 1940 to
1997 were identified. All available pathology slides, gross specimens, and
clinical records were reviewed, eliminating patients with inadequate
documentation. Neoplasms were reclassified as mucinous cystadenomas, noninvasive
proliferative mucinous cystic neoplasms, or invasive cystadenocarcinomas based on
specific histologic criteria. RESULTS: Of 84 patients (70 women, 14 men) with
cystic mucinous neoplasms of the pancreas, 54 were classified as cystadenomas, 23
as noninvasive proliferative cystic mucinous neoplasms, and only 7 as
cystadenocarcinomas. Recurrent disease developed in none of the 77 patients
without invasion, but 5 of the 6 patients surviving resection for
cystadenocarcinomas died of recurrent cystadenocarcinoma within 5 years.
CONCLUSIONS: When the neoplasm is completely resected and subjected to adequate
histopathologic examination based on these objective criteria, absence of tissue
invasion predicts a curative operation and detailed follow-up may be unnecessary.
In contrast, a histologic diagnosis of invasive cystadenocarcinoma portends a
dismal prognosis, similar to that of typical ductal adenocarcinoma of the
pancreas.
PMID- 10674614
TI - Relation among portal segmentation, proper hepatic vein, and external notch of
the caudate lobe in the human liver.
AB - OBJECTIVE: To identify portal segmentation and a portal fissure in the caudate
lobe of the human liver in relation to the hepatic venous system and the external
notch at the caudal edge of the caudate lobe. SUMMARY BACKGROUND DATA: Although
the anatomy of the caudate lobe has been studied, the detailed anatomy has not
yet been clarified; this is necessary to develop safe procedures for caudate lobe
resection. METHODS: A total of 88 formalin-fixed human livers were dissected to
visualize the portal vein and hepatic vein systems of the caudate lobe in
relation to the external notch. RESULTS: The patterns of portal branching were
classified into two types. In 58 livers (67.4%), the territories of the first
order portal branches were clearly divided into two areas (the Spiegel lobe and
the paracaval portion). In the remaining 28 livers (32.6%), the territories of
the second-order portal branches were clearly divided into two areas. These two
areas were distinctly separated by an internal plane, which was coincident with
the external notch. The caudate lobe had a systematized hepatic venous system
that consisted of one (87.5%) or two (11.4%) proper hepatic veins and plural
accessory hepatic veins. The proper hepatic veins laid along the internal plane
between these two portal areas. CONCLUSION: The caudate lobe exhibited distinct
portal segmentation with a portal fissure that was indicated internally by the
proper hepatic vein and externally by the notch at the caudal edge of the caudate
lobe.
PMID- 10674613
TI - Quantitative measurement of P- and E-selectin adhesion molecules in acute
pancreatitis: correlation with distant organ injury.
AB - OBJECTIVE: To determine whether expression of P- and E-selectin molecules is
associated with the development of systemic organ manifestations in acute
pancreatitis (AP). SUMMARY BACKGROUND DATA: Overproduction of inflammatory
cytokines in AP induces expression of adhesion molecules, which may lead to
increased leukocytic infiltration and tissue damage. Understanding the temporal
expression of these molecules could afford better measures for therapeutic
intervention. METHODS: Acute pancreatitis was induced in 30-day-old female C57/
bI/6J mice by feeding a choline-deficient/ethionine-supplemented diet (n = 95).
Mice were divided into three groups. Group I (n = 35) was used to study the
biochemical and histologic manifestations of AP and to evaluate the neutrophilic
infiltration by myeloperoxidase activity and immunofluorescence. Groups II (n =
35) and III (n = 25) were used to evaluate expression of P- and E-selectin by the
dual radiolabeled monoclonal antibody technique. RESULTS: Biochemical and
histologic evidence of AP developed in all mice. The inflammatory cytokine tumor
necrosis factor-alpha gradually increased in serum as early as 18 hours, reaching
more than 800-fold background levels by 72 hours. Biphasic P-selectin expression
in the lung was seen with peaks at 24 and 48 hours; E-selectin expression peaked
at 48 hours. CD18-positive leukocytes and increased myeloperoxidase activity in
the lung were demonstrated at 24 hours, correlating with the onset of selectin
upregulation. Histologic scoring of lung tissue demonstrated mild damage at 24
hours, with progressive injury occurring from 48 to 72 hours. CONCLUSIONS: In AP,
the production of inflammatory cytokines precedes up-regulation of P- and E
selectin, whose expression coincided with the increased infiltration of CD18
positive cells and neutrophil sequestration in lung tissue. Temporally, these
events correlate with evidence of histologic pulmonary injury and underscore the
role of adhesion molecules as mediators of pathophysiologic events. This
mechanistic pathway may afford novel therapeutic interventions in clinical
disease by using blocking agents to ameliorate the systemic manifestations of AP.
PMID- 10674615
TI - Preoperative evaluation of patients with primary head and neck cancer using dual
head 18fluorodeoxyglucose positron emission tomography.
AB - OBJECTIVE: To evaluate the value of 18fluorodeoxyglucose (FDG) positron emission
tomography (PET) in primary head and neck cancer. BACKGROUND DATA: Head and neck
carcinomas tend to metastasize to regional lymph nodes rather than to spread
hematogenously. With nodal metastases, cure rates decrease by approximately 50%.
Moreover, in approximately 3% of the patients, a second primary tumor is found at
initial presentation. METHODS: Fifty-four consecutive patients (31 men and 23
women; mean age 60 years, range 34-81 years) with previously untreated squamous
cell carcinomas of the oral cavity or oropharynx were studied. Before surgery and
within a period of 3 weeks, clinical examination, chest x-ray, computed
tomography (CT), ultrasonography with fine-needle aspiration cytology (US/ FNAC),
and FDG-PET were performed. All study results were scored per neck side and were
also classified as 0 (no metastases), 1 (single metastasis), or 2 (multiple
metastases). RESULTS: The sensitivity for the detection of lymph node metastases
per neck side was 96%, 85%, and 64% for FDG-PET, CT, and US/FNAC, respectively.
The specificity was 90%, 86%, and 100% for FDG-PET, CT, and US/FNAC,
respectively. In terms of the classification, FDG-PET showed the best correlation
with the histologic data. Finally, in nine patients (17%), a second primary tumor
was detected by FDG-PET and confirmed by histologic evaluation. CONCLUSION:
Because of the high prevalence of second primary tumors detected by FDG-PET and
the decreased error rate in the assessment of lymph node involvement compared
with CT and US, FDG-PET should be routinely performed in patients with primary
head and neck cancer.
PMID- 10674616
TI - Mammographically detected ductal carcinoma in situ treated with conservative
surgery with or without radiation therapy: patterns of failure and 10-year
results.
AB - OBJECTIVE: The authors reviewed their institution's experience treating
mammographically detected ductal carcinoma in situ (DCIS) of the breast with
breast-conserving therapy (BCT) to determine 10-year rates of local control and
survival, patterns of failure, and factors associated with outcome. SUMMARY
BACKGROUND DATA: From January 1980 to December 1993, 177 breasts in 172 patients
were treated with BCT for mammographically detected DCIS of the breast at William
Beaumont Hospital, Royal Oak, Michigan. METHODS: All patients underwent an
excisional biopsy, and 65% were reexcised. Thirty-one breasts (18%) were treated
with excision alone, whereas 146 breasts (82%) received postoperative radiation
therapy (RT). All patients undergoing RT received whole-breast irradiation to a
median dose of 50.0 Gy. One hundred thirty-six (93%) received a boost to the
tumor bed for a median total dose of 60.4 Gy. Median follow-up was 5.9 years for
the lumpectomy alone group and 7.2 years for the lumpectomy + RT group. RESULTS:
In the entire population, 15 patients had an ipsilateral breast recurrence. The 5
and 10-year actuarial rates of ipsilateral breast recurrence were 7.8% and 7.8%
for lumpectomy alone and 8.0% and 9.2% for lumpectomy + RT, respectively. Eleven
of the 15 recurrences developed within or immediately adjacent to the lumpectomy
cavity and were designated as true recurrences or marginal misses (TMM). Four
recurred elsewhere in the breast. Eleven of the 15 recurrences were invasive,
whereas 4 were pure DCIS. Only one patient died of disease, yielding 5- and 10
year actuarial cause-specific survival rates of 100% and 99.2%, respectively.
Eleven patients were diagnosed with subsequent contralateral breast cancer,
yielding 5- and 10-year actuarial rates of 5.1% and 8.3%, respectively. Clinical,
pathologic, and treatment-related factors were analyzed for an association with
ipsilateral breast failure or TR/MM. No factors were significantly associated
with ipsilateral breast failure. In the entire population, the omission of RT and
younger age at diagnosis were significantly associated with TR/MM. Patients
younger than 45 years at diagnosis had a significantly higher rate of TR/MM in
both the lumpectomy + RT and lumpectomy alone groups. None of the 37 patients who
received a postexcisional mammogram had an ipsilateral breast failure versus 15
in the patients who did not receive a postexcisional mammogram. CONCLUSIONS:
Patients diagnosed with mammographically detected DCIS of the breast appear to
have excellent 100-year rates of local control and overall survival when treated
with BCT. These results suggest that the use of RT reduces the risk of local
recurrence and that patients diagnosed at a younger age have a higher rate of
local recurrence with or without the use of postoperative RT.
PMID- 10674617
TI - Insulinlike growth factor I plus insulinlike growth factor binding protein 3
attenuates the proinflammatory acute phase response in severely burned children.
AB - OBJECTIVE: To determine the effect of insulinlike growth factor I (IGF-I) in
combination with its principal binding protein (IGFBP-3) on the hepatic acute
phase response in severely burned children. SUMMARY BACKGROUND DATA: The hepatic
acute phase response is a cascade of events initiated to restore homeostasis
after trauma. A prolonged response, however, may contribute to multiple organ
failure, hypermetabolism, complications, and death. METHODS: Twenty-two children
with a mean total body surface area (TBSA) burn of 57 +/- 3% were given a
continuous infusion of 1 to 4 mg/kg/day IGF-I/BP-3 for 5 days after wound
excision and grafting. Eight children with a TBSA burn of 54 +/- 4% were given
saline as controls. Before and 5 days after excision and grafting, blood samples
were taken for serum hepatic constitutive protein, acute phase protein, and
proinflammatory cytokine analysis. RESULTS: Serum IGF-I levels in burned children
given the IGF-I/BP-3 complex increased from 113 +/- 15 to 458 +/- 40 ng/mL and
IGFBP-3 levels increased from 1.8 +/- 0.2 to 3.1 +/- 0.3 ng/mL. Levels of serum
constitutive hepatic proteins (prealbumin, retinol-binding protein, and
transferrin) increased with IGF-I/BP-3, whereas levels of type I acute phase
proteins (C-reactive protein, alpha1-acid glycoprotein, and complement C-3)
decreased when compared with controls. The complex had no effect on type II acute
phase proteins. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL
1beta) levels decreased with IGF-I/BP-3 compared with controls, with no effect on
interleukin-6. CONCLUSION: Severely burned children receiving IGF-I/BP-3 showed a
decrease in IL-1beta and TNF-alpha followed by a decrease in type I acute phase
proteins that was associated with a concomitant increase in constitutive hepatic
proteins. Attenuating the proinflammatory acute phase with IGF-1/BP-3 response
may prevent multiple organ failure and improve clinical outcomes after thermal
injury without any detectable adverse side effects.
PMID- 10674618
TI - Injury induces deficient interleukin-12 production, but interleukin-12 therapy
after injury restores resistance to infection.
AB - OBJECTIVE: To assess at serial intervals the production of interleukin-12 (IL-12)
by monocytes/macrophages from the peripheral blood of injured patients and
control subjects, and using a mouse model to confirm human findings and explore
the effectiveness of low-dose IL-12 therapy in restoring resistance to infection
after injury. SUMMARY BACKGROUND DATA: Serious injury is associated with loss of
function of the T helper 1 lymphocyte phenotype, but little is known about IL-12
production in injured patients. The authors previously reported that early,
moderate-dose IL-12 therapy in a mouse model of burn injury restored resistance
to a later infectious challenge (cecal ligation and puncture, CLP). However, the
efficacy of clinically relevant low-dose IL-12 therapy carried out to or beyond
the time of septic challenge remains to be tested. METHODS: Peripheral blood
mononuclear cells (PBMCs) and adherent cells were obtained from 27 patients with
major burns or traumatic injury and 18 healthy persons and were studied at serial
intervals for IL-12 production stimulated by bacterial lipopolysacharide (LPS).
PBMCs from 18 of the same patients were studied for IL-10 production as well. IL
12 production by adherent cells from the spleens of burn or sham burn mice was
studied at serial intervals after injury to confirm the human findings. Low-dose
IL-12 or vehicle was given every other day to groups of burn and sham burn mice,
which were then challenged with CLP on day 10, and survival was determined.
Finally, spleens were harvested from burn or sham burn animals receiving low-dose
IL-12 or vehicle after CLP. After splenic cellularity was determined by
hemocytometer, splenocytes were cultured and production of tumor necrosis factor
alpha, interferon-gamma, and IL-10 were assessed by immunoassay. RESULTS:
Adherent cells from patients' PBMCs produced significantly less IL-12 than normal
PBMCs after injury, reaching a nadir 8 to 14 days after injury. Stimulation of
whole PBMCs by LPS indicated that at 8 to 14 days after injury, IL-12 production
by PBMCs was significantly lower and IL-10 production was significantly higher
than that of PBMCs from healthy persons. Low-dose IL-12 therapy significantly
increased survival after CLP. Splenocytes from burn mice treated with IL-12 had
significantly increased production of TNF-alpha and IF-beta, both before and
after CLP, when compared with vehicle-treated burn animals. IL-10 production by
bum splenocytes remained high after IL-12 treatment. Splenic cellularity
increased after IL-12 treatment in burn mice. CONCLUSION: The capacity to produce
IL-12 by adherent cells of the monocyte/macrophage lineage is significantly
reduced after serious injury in humans and in a mouse burn model. In humans,
there is a reciprocal relation between diminished IL-12 production and increased
IL-10 production at approximately 1 week after injury. Low-dose IL-12 therapy in
the mouse burn model markedly increased survival after a septic challenge, even
when treatment was carried beyond the onset of sepsis. Low-dose IL-12 treatment
in the mouse increased production of proinflammatory mediators important in host
defense and at the same time maintained or increased production of IL-10, an
important antiinflammatory cytokine.
PMID- 10674619
TI - Survival and functional outcome after prolonged intensive care unit stay.
AB - OBJECTIVE: To examine the functional outcome and costs of a prolonged illness
requiring a stay in the surgical intensive care unit (SICU) of 7 of more days.
SUMMARY BACKGROUND DATA: The long-term benefits and costs after a prolonged SICU
stay have not been well studied. METHODS: All patients with an SICU length of
stay of 7 or more days from July 1, 1996, to June 30, 1997, were enrolled. One
hundred twenty-eight patients met the entry criteria, and mortality status was
known in 127. Functional outcome was determined at baseline and at 1, 3, 6, and
12 months using the Sickness Impact Profile score, which ranges from 0 to 100,
with a score of 30 being severely disabled. Hospital costs for the index
admission and for all readmissions to Johns Hopkins Hospital were obtained. All
data are reported as median values. RESULTS: For the index admission, age was 57
and APACHE II score was 23. The initial length of stay in the ICU was 11 days;
the hospital length of stay was 31 days. The Sickness Impact Profile score was
20.2 at baseline, 42.9 at 1 month, 36.2 at 3 months, and 20.3 at 6 months, and
was lower than baseline at 1 year. The actual 1-year survival rate was 45.3%. The
index admission median cost was $85,806, with 65 total subsequent admissions to
this facility. The cost for a single 1-year survivor was $282,618 (1996).
CONCLUSIONS: An acute surgical illness that results in a prolonged SICU stay has
a substantial in-hospital death rate and is costly, but the functional outcome
from both a physical and physiologic standpoint is compatible with a good quality
of life.
PMID- 10674620
TI - Decreased surgical risks of pancreas transplantation in the modern era.
AB - OBJECTIVE: To document the decreased incidence of surgical complications after
pancreas transplantation in recent times. SUMMARY BACKGROUND DATA: Compared with
other abdominal transplants, pancreas transplants have historically had the
highest incidence of surgical complications. However, over the past few years,
the authors have noted a significant decrease in the incidence of surgical
complications. METHODS: The authors studied the incidence of early (<3 months
after transplant) surgical complications (e.g., relaparotomy, thrombosis,
infections, leaks) after 580 pancreas transplants performed during a 12-year
period. Patients were analyzed and compared in two time groups: era 1 (June 1,
1985, to April 30, 1994, n = 367) and era 2 (May 1, 1994, to June 30, 1997, n =
213). RESULTS: Overall, surgical complications were significantly reduced in era
2 compared with era 1. The relaparotomy rate decreased from 32.4% in era 1 to
18.8% in era 2. Significant risk factors for early relaparotomy were donor age
older than 40 years and recipient obesity. Recipients with relaparotomy had
significantly lower graft survival rates than those without relaparotomy, but
patient survival rates were not significantly different. A major factor
contributing to the lower relaparotomy rate in era 2 was a significant decrease
in the incidence of graft thrombosis; the authors believe this lower incidence is
due to the routine use of postoperative low-dose intravenous heparin and
acetylsalicylic acid. The incidence of bleeding requiring relaparotomy did not
differ between the two eras. Older donor age was the most significant risk factor
for graft thrombosis. The incidence of intraabdominal infections significantly
decreased between the two eras; this decrease may be due to improved prophylaxis
regimens in the first postoperative week. CONCLUSIONS: Although a retrospective
study has its limits, the results of this study, the largest single-center
experience to date, show a significant decrease in the surgical risk associated
with pancreas transplants. Reasons for this decrease are identification of donor
and recipient risk factors, better prophylaxis regimens, refinements in surgical
technique, and improved immunosuppressive regimens. These improved results
suggest that more widespread application of pancreas transplantation is
warranted.
PMID- 10674621
TI - Bactericidal activity against coagulase-negative staphylococci is impaired in
infants receiving long-term parenteral nutrition.
AB - OBJECTIVE: To examine the role of total parenteral nutrition (TPN) in
predisposing infants to infection caused by coagulase-negative staphylococci.
SUMMARY BACKGROUND DATA: Total parenteral nutrition is an important means of
providing essential nutrients to newborn infants. However, its use has been
associated with complications, particularly infection caused by coagulase
negative staphylococci. Recent data suggest that TPN may modulate immune
function; however, reports directly indicating impaired immunity against
coagulase-negative staphylococci during TPN are limited. METHODS: Study 1
involved 31 infants younger than 4 months who had undergone surgery and were not
receiving antibiotics; 20 were receiving TPN and 11 were receiving a normal
enteral diet. An in vitro whole blood model was used to measure the host
bactericidal activity against coagulase-negative staphylococci. Bacterial killing
and phagocytosis were measured after a 45-minute challenge with viable coagulase
negative staphylococci. In study 2, whole blood killing and intracellular killing
of coagulase-negative staphylococci were measured in five newborn infants
(younger than 2 months) who were receiving long-term TPN (>10 days), five control
infants receiving a normal enteral diet, and five healthy adults. RESULTS: In
study 1, infants receiving a normal enteral diet showed a high capacity to ingest
and kill coagulase-negative staphylococci. In contrast, the blood of infants
receiving long-term TPN showed a reduction in coagulase-negative staphylococci
phagocytosis and killing. There were significant negative linear correlations
between the duration of TPN and killing of coagulase-negative staphylococci and
phagocytosis of coagulase-negative staphylococci. In study 2, infants receiving
long-term TPN had lower whole blood killing and intracellular killing than
infants receiving a normal enteral diet and healthy adult volunteers. These data
seem to indicate a neutrophil dysfunction mediated by TPN in infancy.
CONCLUSIONS: Host defense mechanisms, including phagocytosis and killing of
coagulase-negative staphylococci, are impaired during long-term TPN. The impaired
bactericidal activity seems to be related to defective intracellular killing in
neutrophils. These findings may explain the high rate of septicemia caused by
coagulase-negative staphylococci in infants receiving TPN.
PMID- 10674622
TI - Assessment of telemedicine in surgical education and patient care.
AB - OBJECTIVE: To analyze the value of teleconferencing for patient care and surgical
education by assessing the activity of an international academic network. SUMMARY
BACKGROUND DATA: The uses of telemedicine include teleeducation, training, and
consulting, and surgical teams are now involved, sharing diagnostic information
and opinions without the need for travel. However, the value of telematics in
surgery remains to be assessed. METHODS: During a 2-year period, weekly surgical
teleconferences were held among six university hospitals in four European
countries. To assess the accuracy of telediagnosis for surgical cases, 60
randomly selected cases were analyzed by a panel of surgeons. Participants'
opinions were analyzed by questionnaire. RESULTS: Seventy teleconferences (50
lectures and 271 case presentations) were held. Ninety-five of the 114
participants (83.3%) completed the final questionnaire. Eighty-six percent rated
the surgical activity as good or excellent, 75.7% rated the scientific level as
good or excellent, 55.8% rated the daily clinical activity as good or excellent,
and 28.4% rated the manual surgical technique as good or excellent. The target
organ was identified in all the cases; the organ structure and pathology were
considered well defined in 93.3%, and the fine structure was considered well
defined in 58.3%. Diagnosis was accurate in 17 cases (28.3%), probable in 25
(41.7%), possible but uncertain in 16 (26.7%), and not possible in 2 cases
(3.3%). Discussion among the remote sites increased the rate of valuable
therapeutic advice from 55% of cases before the discussion to 95% after the
discussion. Eighty-six percent of the surgeons expressed satisfaction with
telematics for medical education and patient care. CONCLUSIONS: Participant
satisfaction was high, transmission of clinical documents was accurate, and the
opportunity to discuss case documentation and management significantly improved
diagnostic potential, resulting in an accuracy rate of up to 95%. Teleeducation
and teleconsultation in surgery appear to be beneficial.
PMID- 10674623
TI - Neurofibrillary tangles in progressive supranuclear palsy brains exhibit
immunoreactivity to frameshift mutant ubiquitin-B protein.
AB - In Alzheimer's disease (AD) neurofibrillary tangles (NFT) are strongly tau and
ubiquitin immunopositive, and contain an aberrant form of ubiquitin derived from
the ubiquitin-B gene denoted as UBB+1. We explored whether the tau-related NFT
seen in another neurodegenerative disease, progressive supranuclear palsy (PSP),
also showed an accumulation of UBB+1. Three cases of PSP were examined
immunohistochemically for tau protein, ubiquitin-protein conjugates and UBB+1
using single and double labelling. We conclude that UBB+1 is associated with
compact globose tangles rather than dispersed accumulations of tau in PSP,
showing that its presence is not unique to AD. We propose that aggregation of
ubiquitinated proteins into compact inclusions in PSP might be due to inhibition
of the degradation of multiubiquitinated proteins by ubiquitin chains containing
proximal UBB+1 rather than normal ubiquitin.
PMID- 10674624
TI - Cyclosporine-A enhances choline acetyltransferase immunoreactivity in the septal
region of adult rats.
AB - Cyclosporine-A (CsA) is the primary anti-rejection drug used for organ and neural
transplantation therapy. In addition to its immunosuppressive action, CsA has
been recently shown to exert neuroprotective and neurotrophic effects in the
central nervous system when able to cross the blood-brain barrier. Postulated
mechanisms for these CsA-induced beneficial effects include the drug's powerful
inhibition of the calcium-dependent phosphatase calcineurin (CN) and blockade of
the assembly of the mitochondrial permeability transition pore. We report here,
for the first time, that adult Wistar rats treated with CsA (10 mg/kg per day,
i.p. for 9 days) displayed significantly reduced septal CN expression in
combination with enhanced levels of septal choline acetyltransferase (ChAT)
immunoreactivity as compared to controls. The observed enhancement of septal ChAT
immunoreactivity suggests potential therapeutic utility of CsA for brain
disorders characterized by alterations of the cholinergic system.
PMID- 10674625
TI - Are there anticipatory segmental adjustments associated with lower limb flexions
when balance is poor in humans?
AB - For a leg raising task performed in a sagittal plane, it has been shown that body
balance instability can suppress anticipatory postural adjustments (APAs). The
aim of this study was to determine whether the global (centre of mass) postural
adjustments were replaced by local (segmental) ones, which were compensating each
other and resulting in a lack of global APAs. Six healthy subjects must perform a
lower limb flexion from two initial postures, corresponding to a bipedal (Fbu)
and an unipedal (Fuu) stance. Kinematics of postural adjustments were recorded
with accelerometers. The results showed that in Fbu the kinematics have large
durations of APAs, contrary to Fuu where there are none. They showed also that
during the voluntary movement the magnitudes of the segmental postural
accelerations were equal or superior in Fuu than in Fbu on the anteroposterior
and lateral axes, where balance is poor. Also while, on the contrary, the
magnitudes are reversed on the vertical axis. These results suggest that firstly:
(1) the absence of APAs can correspond to a strategic response for weak postural
base configuration and secondly; (2) the local postural accelerations, depending
to the axes, are linked to two different functions: to maintaining the balance
and to performing the focal movement.
PMID- 10674626
TI - Structural comparison of zebrafish Elav/Hu and their differential expressions
during neurogenesis.
AB - The present communication reports the isolation and characterization of three new
zebrafish elav/Hu (Kim, C.-H., Ueshima, E., Muraoka, O., Tanaka, H., Yeo, S.-Y.,
Huh, T.-L. and Miki, N., Zebrafish elav/HuC homologue as a very early neuronal
marker. Neurosci. Lett., 216 (1996) 109-112) homologues, HuA, HuD and HuG. While
HuA and HuG showed weak and ubiquitous expressions, HuD, as well as HuC, were
specifically expressed in the neuronal cells. The first expression of HuD was
detectable of the 10-somite stage, that is, several hours later than HuC. After
24 h of embryonic development, although HuD and HuC expressions overlapped
overall, the cells expressing HuD were restricted to subsets of the HuC-positive
neuronal cells in the brain and spinal cord. These differentially regulated
spatial and temporal expression patterns implied distinct roles for HuC and HuD
in neuronal determination and neuronal differentiation, respectively.
PMID- 10674627
TI - Apoptotic cell death in rat brain following deltamethrin treatment.
AB - In the present study we identified the degeneration and apoptotic cell death in
rat brain after deltamethrin treatment. By hematoxylin-eosin (H&E) staining, a
large number of degenerative cells (pyknosis of nuclei, disruption of
eosinophilic cytoplasm) were seen in the hippocampus and cortex at 24 and 48 h
after deltamethrin treatment at a dose of 12.5 mg/kg (i.p.) in corn oil. The
similar morphological changes of degenerative cells were observed by cresyl
violet staining. Numerous apoptotic cells were detected by in situ end labeling
(ISEL) and flow cytometric analysis in the hippocampus and cortex at 24 and 48 h
following deltamethrin treatment at the same dose, whereas no ISEL-positive cells
were seen in the same brain regions of control rats. Moreover, using DNA gel
electrophoresis, it was demonstrated that DNA fragmentation was markedly induced
in the hippocampus and cortex at 24, 48 and 72 h after treatment. In addition,
the protein synthesis inhibitor cycloheximide inhibited the DNA fragmentation
elicited by deltamethrin in rat brain. These results indicate that deltamethrin
induces degeneration and apoptotic cell death in rat brain, suggesting an
important role played by apoptosis in neurotoxicity of deltamethrin.
PMID- 10674628
TI - Immunohistochemical localization of neurocalcin in human sensory neurons and
mechanoreceptors.
AB - The localization of neurocalcin in the developing and adult human peripheral
nervous system (dorsal root and sympathetic ganglia (DRG, SG), and enteric
nervous system (ENS)) was investigated using immunohistochemistry. A
subpopulation of large-sized neurons in DRG of 9 and 12 weeks old embryos showed
immunoreactivity (IR), whereas the sympathetic ganglia or enteric neurons did
not. In adults, neurocalcin IR was restricted to a subpopulation of large (13%)
and intermediate (15%) sized neurons in DRG. The protein was also found in
muscular (67%) and cutaneous (12%) nerve fibers, as well as in the axons
supplying muscular (muscle spindles, Golgi's tendon organs, and perimysial
Pacinian corpuscles) and cutaneous (Meissner's but not Pacinian corpuscles)
mechanoreceptors, as well as motor end-plates. Present results demonstrate that
neurocalcin in both developing and adult humans can be used as a specific marker
for a subpopulation of sensory neurons coupled to proprioception and touch, and
for axons of motoneurons forming motor end-plates.
PMID- 10674629
TI - Argatroban, a thrombin inhibitor, decreased mortality after 10 min of forebrain
ischemia in the gerbil.
AB - We investigated whether anticoagulant therapy with heparin or a selective
thrombin inhibitor, argatroban, may ameliorate the postischemic cerebral
circulation and attenuate mortality after 10 min of forebrain ischemia.
Postischemic subcutaneous injection of argatroban (5 mg/kg) significantly
attenuated mortality (9.1%) compared with non-treatment (45.5%) during 14 days'
observation period. This effect coincided with: (1) increased cortical CBF after
reperfusion; (2) attenuation of brain edema; and (3) less severe cell damages in
the cerebral cortex. In contrast, nine of the 22 gerbils treated with heparin
(830 IU/kg) were found dead on the next day due to massive bleeding in the
surgical wound and 13 bleeding-avoided gerbils did not show significant
amelioration in mortality (30.8%). These findings suggest that argatroban is an
effective anticoagulant for prevention of cell damage after a relatively long
forebrain ischemia.
PMID- 10674630
TI - Activation of calpain precedes morphological alterations during hydrogen peroxide
induced apoptosis in neuronally differentiated mouse embryonal carcinoma P19 cell
line.
AB - In order to reveal neurodegeneration elicited by reactive oxygen intermediates
(ROI), neuronally differentiated cells from mouse embryonal carcinoma P19 cell
line were exposed to hydrogen peroxide (H2O2). Enhanced protein-phosphorylation
on tyrosine residues was detectable within 5 min of exposure to H2O2, and gradual
rises in intracellular free Ca2+ level and in calpain activity were observed.
Furthermore, H2O2 stimulation of differentiated P19 cells for 24 h resulted in
morphological alterations in somas as well as neurites. Also, within 6 h of H2O2
treatment DNA fragmentation has been detected. Taken together, these results
suggest that oxidative stress induces degradation of cytoskeletal proteins
presumably resulting from increased intracellular Ca2+ concentration and
subsequent activation of calpain.
PMID- 10674631
TI - Expression of induced nitric oxide synthase in amoeboid microglia in postnatal
rats following an exposure to hypoxia.
AB - The present study showed the expression of induced nitric oxide synthase (iNOS)
immunoreactivity in amoeboid microglia following an exposure to transient hypoxia
in postnatal rats. iNOS immunoreactivity was expressed mainly in the amoeboid
microglia in corpus callosum and subependymal regions of the ventricles within 3
h after hypoxia. The expression declined after 5 h, and became undetectable after
15 h and in longer surviving rats. The immunoreactivity of these cells with OX
42, which is a marker for microglia cells and detects complement type three
receptors (CR3), was comparable in the rats exposed to hypoxia and the control
rats. Immunoglobulin G (IgG) immunoreactivity was observed in the amoeboid
microglia up to 3 h after hypoxia but it was undetectable in longer surviving
rats and in the control rats. The iNOS expression in the amoeboid mircoglial
cells may be related to the host defense and maintenance of structural integrity
of the highly vulnerable periventricular white matter after hypoxia. The
immunostaining of amoeboid microglial cells with IgG following hypoxia indicates
leakage of plasma immunoglobulin from the blood vessels and its removal by the
amoeboid microglial cells.
PMID- 10674632
TI - Chronic hyperglycaemia increases neuronal sensitivity to high potassium in
hippocampal slices from streptozotocin-treated diabetic rats.
AB - The chronic hyperglycaemia associated with diabetes mellitus increases
susceptibility to epileptiform-like activity in the central nervous system.
Changes in extracellular potassium levels directly influence neuronal
excitability and significantly one of the major regulators of extracellular
potassium, the Na-K ATPase, is known to be down-regulated by chronic
hyperglycaemia. The sensitivity of hippocampal slices, from rats made diabetic
for 2-3 weeks with streptozotocin, to increases in the extracellular potassium
concentration ([K+]o) was, therefore, investigated. Raising [K+]o to 10 mM
increased the number of orthodromically-evoked population spikes (PSs) in area
CA1. This recruitment was significantly greater in hippocampal slices from
diabetic rats, which also exhibited significantly more spontaneous activity.
These findings confirm a diabetes-dependent increase in sensitivity of central
neurones to changes in [K+]o and may help to explain the increased susceptibility
to epileptiform activity in this disease state.
PMID- 10674633
TI - Diurnal variation in orexin A immunoreactivity and prepro-orexin mRNA in the rat
central nervous system.
AB - Orexins are a family of neuropeptides originally believed to be important
mediators of food intake. The wide distribution of orexins and their receptors,
however, has suggested other regulatory functions for these peptides including
involvement in sleep and arousal mechanisms. In this study, we have demonstrated
diurnal variation in orexin A immunoreactivity in the pons, from where locus
coeruleus noradrenergic neurones innervate other brain areas to stimulate
arousal, and in the preoptic/anterior hypothalamic region, an area implicated in
the regulation of sleep and circadian rhythms. Orexin A immunoreactivity
decreased by 50% in the preoptic/anterior hypothalamus from 09:00 to 21:00 h (P <
0.0001), whilst in the pons, it increased by over 30% from 09:00 to 01:00 h (P =
0.02). Prepro-orexin mRNA also displayed diurnal variation. This further suggests
that orexins are involved in the regulation of the sleep/wake cycle.
PMID- 10674634
TI - Receptor mechanisms mediating differentiation and proliferation effects of
retinoids on neuroblastoma cells.
AB - The aim of this study was to clarify retinoid receptor mechanisms mediating the
effects of 9-cis retinoic acid (RA) and investigate the ability of RAR- and RXR
specific analogues to induce differentiation and inhibit proliferation in
neuroblastoma cells. Differentiation and the inhibition of proliferation by 9-cis
RA, but not all-trans RA, were inhibited by the RXR-homodimer antagonist LG745.
The RXR-specific agonist LGD1069 was ineffective at inducing differentiation or
inhibiting proliferation, but showed marked synergism with RAR-specific agonists
with respect to inhibiting proliferation. These data suggest that the effects of
9-cis RA are mediated via both RXR-homodimers and heterodimers. However,
combinations of RAR- and RXR-selective analogues were not as effective at
promoting differentiation. This study indicates that different receptor
mechanisms are involved in retinoid-induced differentiation and inhibition of
proliferation in neuroblastoma cells.
PMID- 10674635
TI - Age-dependent changes in phosphorylated cAMP response element-binding protein
immunoreactivity in motoneurons of the spinal nucleus of the bulbocavernosus of
male rats.
AB - Phosphorylated cAMP response element-binding protein (CREB) immunoreactivity was
examined in motoneurons of the spinal nucleus of the bulbocavernosus (SNB) in
young and old male rats by immunohistochemistry. In young animals, intense CREB
immunoreactivity was confined to the cell nucleus, but not in the nucleolus of
SNB motoneurons. In old animals, both the intensity of CREB immunoreactivity in
the nuclei and number of CREB immunoreactive nuclei of the SNB motoneurons were
significantly reduced. A marked decline in expression of CREB in the aged SNB
motoneurons suggests alternation of cAMP-mediated regulation of gene expression
in the SNB system with advancing age.
PMID- 10674636
TI - Endogenous adenosine regulates the effects of low-frequency stimulation on the
induction of long-term potentiation in CA1 neurons of guinea pig hippocampal
slices.
AB - A train of low-frequency afferent stimuli (LFS, 1 Hz, 1000 pulses), given 60 min
prior to a tetanus (100 Hz, 100 pulses), suppresses the induction of long-term
potentiation (LTP) in which a short-term potentiation decreases gradually back to
the pre-tetanic level within 40-50 min (LTP suppression). We investigated the
effects of adenosine A1 or A2 receptor antagonists (8-cyclopentyltheophylline (8
CPT) and CP-66713, respectively) on LTP suppression in CA1 neurons of guinea pig
hippocampal slices. When the LFS was delivered in the presence of 8-CPT (1
microM), LTP suppression was not significantly affected. However, when LFS was
delivered in the presence of CP-66713 (10 microM), LTP suppression was inhibited,
leading to successful LTP induction. These results indicate that endogenous
adenosine, acting via A2 receptors, is involved in the mechanism of LTP
suppression.
PMID- 10674637
TI - Synapsin III gene polymorphisms and schizophrenia.
AB - Synapsins are synaptic vesicle-associated phosphoproteins and are thought to play
crucial roles in synaptogenesis and neurotransmitter release. Synaptic
abnormalities have been reported in the pathophysiology of schizophrenia. In
addition, the synapsin III gene, a member of the synapsin gene family, has been
located at 22q12-13, which has been suggested as a potential susceptibility locus
for schizophrenia. We investigated a genetic association between schizophrenia
and the synapsin III gene polymorphisms (-631C/G and -196G/A) in 160
schizophrenic patients and 153 controls. No significant positive association
between either polymorphism and schizophrenia was observed. Furthermore, no
significant association was observed between either polymorphism and the
diagnostic subtypes. Our results suggested that the synapsin III gene
polymorphisms do not confer increased susceptibility to schizophrenia.
PMID- 10674638
TI - Melioidosis as an emerging global problem.
AB - There is remarkably little known about the incidence of melioidosis outside a few
countries (Thailand, Australia, Singapore and Malaysia). Presumably it is
widespread in tropical south east Asia. Elsewhere there are tantalising glimpses
of the tip of what may be a large iceberg. Since a specific diagnosis of
melioidosis requires awareness on the part of clinicians, and the existence of a
laboratory capable of isolating and identifying Burkholderia pseudomallei, a
luxury not available in most rural tropical areas, the size of this iceberg is
likely to remain unknown for the foreseeable future. There is mounting evidence
that the disease is endemic in the Indian sub-continent and the Caribbean, and
there have been unsubstantiated reports of recent cases in South Africa and the
Middle East. It is unclear whether melioidosis has really spread to such areas
relatively recently, or has been there but unrecognised for a long time. Almost
all cases diagnosed in temperate climates have been imported from the tropics,
with the exception of a unique outbreak which occurred in France in the mid
1970s. With increasing world wide travel of both humans and other animals, the
potential exists for melioidosis to spread to new and fertile pastures.
PMID- 10674639
TI - The epidemiology of melioidosis in Australia and Papua New Guinea.
AB - Melioidosis was first described in Australia in an outbreak in sheep in 1949 in
north Queensland (22 degrees S). Human melioidosis was first described from
Townsville (19 degrees S) in 1950. Melioidosis is hyperendemic in the Top End of
the Northern Territory (NT) and as in parts of northeastern Thailand it is the
commonest cause of fatal community-acquired septicemic pneumonia. In the 9 years
since 1989 the prospective NT melioidosis study at Royal Darwin Hospital (12
degrees S) has documented 206 culture confirmed cases of melioidosis, with an
average annual incidence of 16.5/100,000. Melioidosis is also seen in the north
of Western Australia and north Queensland, including the Torres Strait Islands,
but is uncommon in adjacent Papua New Guinea. Serological studies suggest that
infection is rare in the Port Moresby region, but there is emerging evidence of
melioidosis from Western Province. The NT study has documented inoculating events
in 52 (25%) of cases, with an incubation period of 1-21 days (mean 9 days); 84%
of cases had acute disease from presumed recent acquisition and 13% had chronic
disease (sick, > 2 months). In 4% there was evidence of possible reactivation
from a latent focus; 28 of 153 (18%) males had prostatic abscesses. The overall
mortality was 21% (43 cases), with a mortality rate in septicemic cases (95) of
39% and in non-septicemic cases (103) of 4%. Pneumonia was the commonest
presentation in both groups and, in addition, eight patients (two deaths)
presented with melioidosis encephalomyelitis. Melioidosis clusters in temperate
Australia are attributed to animals imported from the north. Molecular typing of
Burkholderia pseudomallei isolates from temperate southwest Western Australia
showed clonality over 25 years. In this outbreak and in studies from the NT, some
soil isolates are molecularly identical to epidemiologically related animal and
human isolates. Molecular typing has implicated the water supply in two clonal
outbreaks in remote aboriginal communities in northern Australia. Further
prospective collaborative studies are required to evaluate whether there are
truly regional differences in clinical features of melioidosis and to better
understand how B. pseudomallei is acquired from the environment.
PMID- 10674640
TI - Melioidosis in Southeast Asia.
PMID- 10674641
TI - Recent advances in the treatment of severe melioidosis.
AB - For the last decade, high-dose intravenous ceftazidime has been the drug of
choice for the treatment of severe melioidosis, after ceftazidime was shown to be
superior to the 'conventional' four-drug regimen (chloramphenicol, doxycycline
and trimethoprim-sulphamethoxazole) in a randomised trial. Combination
ceftazidime-trimethoprim-sulphamethoxazole was compared with the conventional
regimen in a separate trial with similar results, but we still do not know
whether such combination therapy is needed in melioidosis. Co-amoxiclav
(amoxycillin-clavulanate) has been shown to be effective but was associated with
a higher rate of treatment failure than ceftazidime. Two further treatment trials
in acute melioidosis have recently been conducted in Thailand. In the first of
these, high-dose intravenous imipenem was compared with ceftazidime and the
results suggest that the two regimens possess similar efficacy. Cefoperazone
sulbactam has been compared with ceftazidime-trimethoprim-sulphamethoxazole in a
small number of patients, and further results are awaited. Relapses of
melioidosis should be treated in a similar manner to primary infections.
PMID- 10674642
TI - Antimicrobial resistance in Burkholderia pseudomallei.
AB - Four strains of Burkholderia pseudomallei were used to determine the minimum
inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time
kill curves with 13 single antimicrobial agents: ceftazidime, piperacillin,
imipenem, amoxicillin/clavulanic acid, doxycycline, cotrimoxazole, kanamycin,
rifampicin, ciprofloxacin, trovafloxacin, clarithromycin, azithromycin and
meropenem. The time-kill studies were also performed with 33 pairs of
combinations of the above antimicrobial agents: 15 combinations which would be
expected to be used for acute therapy and 18 combinations for maintenance
therapy. The results show that the single and combination antimicrobial agents
with bactericidal effects against the four strains of B. pseudomallei which
should be used for clinical trials in acute melioidosis are: imipenem, meropenem,
and imipenem + azithromycin. The combination antimicrobial agents which should be
further studied for the ability to eliminate biofilm and intracellular killing
effect are ciprofloxacin + clarithromycin, ciprofloxacin + azithromycin, and
imipenem + azithromycin.
PMID- 10674643
TI - Neurological melioidosis.
AB - Neurological abnormalities have long been recognised in animals with melioidosis,
including laboratory rodents and sheep in the first Australian outbreak in 1949.
Autopsies in animals have shown microabscesses and lymphocytic infiltration to be
present on occasion in the same animal, but Burkholderia pseudomallei is usually
able to be grown from central nervous system (CNS) tissue. In humans CNS
melioidosis is unusual, but both macroscopic brain abscesses and encephalitis
occur. There has been a recently recognised syndrome of meningoencephalitis with
varying involvement of brainstem, cerebellum and spinal cord. The prospective
melioidosis study at Royal Darwin Hospital has documented 12 cases of CNS
melioidosis over 9 years out of a total of 232 cases of melioidosis (5%).
Prominent features on presentation were unilateral limb weakness (6), predominant
cerebellar signs (2), mixed cerebellar and brainstem features with peripheral
weakness (2) and flaccid paraparesis (2). Eight patients had unilateral VIIth
nerve palsy and six bulbar palsy, with five requiring prolonged ventilation.
Brain CT scans are usually normal initially, but MRI shows dramatic changes.
Three patients died and only three made a full recovery. In two patients with
predominant mononuclear CSF pleocytosis, B. pseudomallei was cultured from CSF
and autopsy in one of these showed necrotising encephalitis with microabscesses.
Although it has been postulated that a neurotropic exotoxin may account for
melioidosis encephalomyelitis, the recent findings and comparison with the animal
data suggest that direct organism spread within the CNS may be primarily
responsible. Preliminary molecular typing of isolates shows no evidence of a
specific strain of B. pseudomallei responsible for CNS melioidosis end further
studies are required to determine if the apparent higher rate of CNS disease in
Australia is due to true regional differences or is from increased ascertainment.
PMID- 10674644
TI - Animal melioidosis in Australia.
AB - Melioidosis was first diagnosed in Australia in sheep in 1949. While it has been
considered endemic in tropical Australia, there have been animal outbreaks in
southwest Western Australia and southern Queensland. Infection occurs in many
species, with both latency and a wide range of clinical manifestations. Some
species may develop melioidosis only if immunocompromised. Sheep and goats are
particularly susceptible, resulting in the requirement for pasteurisation of
tropical commercial goat's milk. Nine out of 43 (21%) goats had aortic lesions at
autopsy and seven died from aortic aneurysm rupture. Transplacental transmission
in goats has also been documented. Asymptomatic organ abscesses are common in
pigs but bovine melioidosis is very rare. Camels moved north and an alpaca
brought to Darwin have died from melioidosis. It also occurs in wildlife,
including birds, crocodiles and kangaroos. Zoonotic transmission to humans is
extremely unusual, but there are many similar epidemiological and clinical
features of melioidosis in animals and humans. There have been three possible
zoonotic cases in Australia. Molecular typing has found identical Burkholderia
pseudomallei organisms from animals, humans and soil. The study of melioidosis in
animals, especially the use of molecular genetic techniques for organism
identification and typing, will continue to unravel aspects of the disease that
remain unclear in humans.
PMID- 10674645
TI - Ecology of Burkholderia pseudomallei and the interactions between environmental
Burkholderia spp. and human-animal hosts.
AB - Early workers thought that melioidosis was a zoonosis with a reservoir in
rodents, but we now know that Burkholderia pseudomallei is a widely distributed
environmental saprophyte. In northeast Thailand, two thirds of paddy fields yield
the organism, and 80% of children have antibodies by the time they are 4 years
old. However, interpretation of these results has been complicated by the recent
recognition of avirulent, antigenically cross-reacting environmental organisms
for which the name B. thailandensis has been proposed. We still know very little
about the climatic, physical, chemical and biological factors which control the
proliferation and survival of Burkholderia spp. in the environment, although
epidemiological studies show space-time clustering of melioidosis. It is assumed
that most human and animal melioidosis arises through exposure to contaminated
soil or muddy water, although only 6% of human cases have a clear history of
inoculation, and a further 0.5% of cases follow near-drowning. Laboratory animals
have also been infected by ingestion, inhalation and insect bites, but evidence
of infection acquired naturally by these routes remains anecdotal. Sporadic cases
have resulted from iatrogenic inoculation, laboratory accidents, and person-to
person or animal-to-person spread. Whether exposure to B. pseudomallei will
result in disease probably depends on the balance between the virulence of the
strain, the immune status of the host (e.g. diabetes mellitus) and the size of
the inoculum.
PMID- 10674646
TI - Multiple replicons constitute the 6.5-megabase genome of Burkholderia
pseudomallei.
AB - Burkholderia pseudomallei is a causative agent of melioidosis, a fatal tropical
infectious disease endemic in Southeast Asia and Northern Australia. In order to
determine the size and characteristics of the bacterial genome, the B.
pseudomallei genome and genes were analyzed by pulsed field gel electrophoresis
of the undigested, intact megabase DNA, and by computational analysis of
nucleotide sequences of B. pseudomallei genes which have been sequenced by
several investigators and already deposited in a public database. The results
showed that the B. pseudomallei genome consists of two large replicons, and that
both contain ribosomal RNA gene sequences, indicating the presence of two
chromosomes. The classical arabinose-negative B. pseudomallei isolate K96243 has
chromosomes of approximately 3563 +/- 73 and 2974 +/- 40 kilobase-pairs in size,
giving a total genome size of about 6.5 million base-pairs. The arabinose
positive nonvirulent biotype of B. pseudomallei also has two replicons which are
smaller than those of the arabinose-negative biotype. Analysis of the publicly
available nucleotide sequences showed that the average B. pseudomallei gene is
approximately 1031 base-pairs in size, with an average G + C content of 65.7%.
The genome is gene-rich and about 89% of the coding capacity is used as coding
sequences. It can therefore be estimated that the entire B. pseudomallei genome
encodes about 5600 genes.
PMID- 10674647
TI - Molecular phylogeny of Burkholderia pseudomallei.
AB - In terms of population structure, the species Burkholderia pseudomallei contains
both clonal and non-clonal elements. By indexing variation in rRNA loci using the
restriction endonuclease BamHI, we found that two ribotypes (types 1 and 3) are
predominant in nature. Ribotype 3 is prevalent in Asian countries while ribotype
1 is more widespread. Some disease association was suggested for 4 ribotypes and
strains of ribotype 4 were markedly associated with a fatal outcome. DNA
macrorestriction (XbaI) profiles resolved by pulsed-field gel electrophoresis
revealed great heterogeneity within the prevalent ribotypes and these profiles
appeared to be reliable strain markers. Arabinose environmental strains were
characterised by BamHI ribotypes that were markedly distinct form clinical and
environmental isolates of the arabinose negative phenotype.
PMID- 10674648
TI - Genome fingerprinting by pulsed-field gel electrophoresis of isolates of
Burkholderia pseudomallei from patients with melioidosis in Thailand.
AB - A total of 95 isolates of Burkholderia pseudomallei from 53 sporadic cases in
Thailand were examined by pulsed-field gel electrophoresis. Digestion of genomic
DNA of all isolates by NcoI generated a macrorestriction pattern similar to that
of B. pseudomallei which cannot assimilate L-arabinose. Analysis using
restriction enzymes SpeI and AvrII demonstrated greater sensitivity than NcoI
digestion in the differentiation of B. pseudomallei and could be used for
epidemiological groupings. Four cluster groups were evident among 37 isolates
tested and the majority of isolates within each cluster displayed more than 65%
similarity. Furthermore, multiple isolates from 18 and 35 patients with single
and recurrent episodes of melioidosis, respectively, were examined. All patients
with a single episode yielded genetically identical isolates and four of 35
patients with recurrent episodes were infected with strains of different
genotypic patterns from the primary isolate(s). Hence, most repeated episodes of
infection in melioidosis are as a result of the original infecting strains.
PMID- 10674649
TI - Use of multiplex PCR patterns as genetic markers for Burkholderia pseudomallei.
AB - A simple PCR-based typing method was developed to differentiate between strains
of Burkholderia pseudomallei. Two pairs of primers, based on sequences from two
specific DNA probes, were used to amplify the bacterial DNA by multiplex PCR. We
evaluated the PCR method for epidemiological typing of B. pseudomallei and
compared this with restriction fragment length polymorphism (RFLP) and random
amplified polymorphic DNA (RAPD) methods. In RFLP, the DNA of B. pseudomallei was
digested with HindIII and the pKKU-S23L was used as a probe while 5' GTTTCGCTCC
3' primer was used in RAPD. DNA was obtained from 37 B. pseudomallei
environmental and clinical isolates from humans or animals. These isolates were
also classified by their ability to assimilate L-arabinose. A total of 21 type
patterns were identified by multiplex PCR. Among human and animal isolates,
multiplex PCR revealed ten types, all of which were arabinose negative (Ara-),
whereas six of the 11 types of environmental isolates were Ara-. There are two
environmental patterns that also were found in clinical isolates. The RFLP
technique showed 12 different types in the 37 isolates, and three of these
contained both Ara+ and Ara- isolates. The RAPD technique revealed 33 different
types in the 37 isolates. Multiplex PCR, therefore, is the genetic marker that
best correlates with the ability of the organism to assimilate L-arabinose.
Moreover, two types (M4, M15) correlated with disseminated septicemic melioidosis
in the northeast Thailand. If a greater number of isolates are tested, the
multiplex PCR technique may prove to be useful for rapid epidemiological typing
of B. pseudomallei.
PMID- 10674650
TI - Pathogenesis of and immunity to melioidosis.
AB - While Burkholderia pseudomallei, the causative agent of melioidosis, is becoming
increasingly recognized as a significant cause of morbidity and mortality in
regions to which it is endemic, no licensed vaccine preparation currently exists
for immunization against the disease. Therefore, one of the primary goals of our
research has been to identify and characterize antigens expressed by B.
pseudomallei isolates for the intended purpose of developing a vaccine construct
that can be used to actively immunize specific high risk populations against the
disease. By utilizing a combination of biochemical, immunological and molecular
approaches, our studies now indicate that some of the most promising candidates
for this task include flagellin proteins and the endotoxin derived O
polysaccharide (PS) antigens expressed by the organism. In this review, we have
attempted to summarize the current status of B. pseudomallei research while
endeavoring to provide a rationale for our approach towards the development of a
melioidosis vaccine.
PMID- 10674651
TI - Exopolysaccharides of Burkholderia pseudomallei.
PMID- 10674652
TI - Protease production by Burkholderia pseudomallei and virulence in mice.
AB - The aim of this study was to assess protease production and virulence of various
Burkholderia pseudomallei strains. Protease activity was evaluated in filtrates
from cultures grown for 50 h in TSB Dialysate by azocasein hydrolysis, and
expressed as absorbancy at 405 nm. Virulence was assessed in 8 weeks old SWISS
mice, by intraperitoneal injection of 6-6 x 10(5) CFU, and the LD50 was
calculated after 30 days by the method of Reed and Muench. The lethal activity
was studied for five strains of B. pseudomallei and the type strains of
Burkholderia pseudomallei, Burkholderia mallei, and Burkholderia cepacia. The
three type strains appeared to be low protease producers (A405 = 0.11, 0.09 and
0.00, respectively) and avirulent. The two more virulent B. pseudomallei strains
exhibited significantly different LD50, 3.5 x 10(2) (IPP 6068 VIR) versus 2.1 x
10(5) CFU/mouse (40/97), and protease activities (A405 = 0.046 and 0.79,
respectively). Moreover, the avirulent parent of IPP 6068 (AG), was a better
protease producer than the 6068 VIR strain, A405 = 0.26 versus 0.046. These
results suggest that there is no correlation between virulence and level of
exoproteolytic activity, when B. pseudomallei is injected to mice via the
intraperitoneal route.
PMID- 10674653
TI - Shedding of lipopolysaccharide and 200-kDa surface antigen during the in vitro
growth of virulent Ara- and avirulent Ara+ Burkholderia pseudomallei.
AB - Non-virulent Ara+ B. pseudomallei environmental isolates differ from virulent Ara
clinical isolates by their ability to assimilate L-arabinose and the absence of
a 200 kDa antigen on their surface. The latter, present only on the Ara- isolates
from either clinical or environmental origin, was recently demonstrated by its
immunoreactivity with monoclonal antibody (MAb) 5F8. We recently demonstrated
that lipopolysaccharide (LPS) from both biotypes were indistinguishable from one
another with regard to SDS-PAGE profiles and immunoreactivities with immune sera.
In this study, the shedding of LPS and 200-kDa antigen into the culture medium
during the in vitro growth of Ara- was compared with that of its Ara+
counterpart, using MAb-based sandwich ELISAs. The results showed that the LPS
shedding profiles from the two biotypes were similar to one another. This was in
contrast to the situation with the 5F8-reactive antigen. The culture fluid of all
Ara- isolates and none of the Ara+ isolates were found to react strongly with the
MAb 5F8 during the early log phase of growth. However, during the late stationary
phase, a trace amount of the 5F8-reactive material could also be detected in the
culture fluid of the Ara+ isolates.
PMID- 10674654
TI - Proinflammatory cytokine mRNA responses in experimental Burkholderia pseudomallei
infection in mice.
AB - Melioidosis is a potentially fatal disease of both human and animals caused by
the bacterium Burkholderia pseudomallei. Disease is endemic in tropical and
subtropical regions of Southeast Asia and Northern Australia. The pathogenesis of
melioidosis is poorly understood. In particular, the host responses that occur
following infection, and the specific host-pathogen interactions that result in
the development of either acute or chronic infection are unclear. Using an
established murine model, we investigated early proinflammatory cytokine
responses believed to be critical in the development of acute and chronic B.
pseudomallei infection. Semi-quantitative reverse transcription polymerase chain
reaction (RT-PCR) was used to assess levels of mRNA for tumor necrosis factor
alpha (TNF-alpha), interleukin 1beta (IL-1beta) and interleukin 6 (IL-6) in the
liver of mice following infection. We demonstrate that the level of mRNA for
these cytokines increase moderately in chronic infection in C57BL/6 mice.
However, in acute infection in BALB/c mice, mRNA responses for these cytokines
were shown to be comparatively greater. These results demonstrate that early
proinflammatory cytokine responses are important in the immunopathogenesis of
melioidosis.
PMID- 10674655
TI - Recent developments in laboratory diagnosis of melioidosis.
PMID- 10674656
TI - Comparison of three PCR primer sets for diagnosis of septicemic melioidosis.
AB - Several sets of PCR primers have recently been developed for detection of
Burkholderia pseudomallei. In this report, the performance of 16S rRNA gene
primers (16S), rRNA spacer gene primers (spacer), and 'LPS' primers (LPS) were
compared. All primer sets were tested by PCR amplification of the same DNA
samples extracted from blood specimens of 46 patients from northeastern Thailand,
of which 29 had melioidosis based on blood culture as a gold standard. The
sensitivities were 41, 35.7, and 31% while the specificities were 47, 59, and
100% for the 16S, spacer, and LPS primers, respectively. The positive predictive
values were 60, 59, and 100%, while negative predictive values were 35, 34, and
46%, for these primers. The low sensitivity of PCR was suspected to be because of
small numbers of bacteria in the samples. In addition, one primer set could not
detect all B. pseudomallei strains. To make PCR for melioidosis more practical,
bacterial concentration steps must be added. Lastly, mixed infection of patients
in endemic areas may be the cause of controversial false positive PCR results,
and should be further investigated.
PMID- 10674657
TI - Malaria gametocytes.
PMID- 10674658
TI - Hantavirus (Bunyaviridae) infections in rodents from Orange and San Diego
Counties, California.
PMID- 10674659
TI - Hantavirus infections in rodents
PMID- 10674660
TI - A phase I safety and immunogenicity trial with the candidate malaria vaccine
RTS,S/SBAS2 in semi-immune adults in The Gambia.
AB - RTS,S is a novel pre-erythrocytic malaria vaccine based on the circumsporozoite
surface protein (CSP) of Plasmodium falciparum linked to hepatitis B surface
antigen (HBs) and combined with a novel adjuvant system (SBAS2). We have
conducted a Phase I trial with three doses of this vaccine given at 0, 1, and 6
months to 20 semi-immune, adult, male volunteers in The Gambia to assess its
safety and immunogenicity. Eighteen of the 20 volunteers completed the study.
There were no clinically significant local or systemic adverse events following
each vaccination. Hematologic and biochemical indices before and two weeks after
each vaccination showed no evidence of toxicity. Antibody titers to both CSP and
HBs showed a significant increase after vaccination; these were the largest after
the third dose. We conclude that the RTS,S/SBAS2 vaccine induces no significant
toxicity in this semi-immune population and produces significant increases in
antibody titers to CSP.
PMID- 10674661
TI - Safety, immunogenicity, and lot stability of the whole cell/recombinant B subunit
(WC/rCTB) cholera vaccine in Peruvian adults and children.
AB - To assess the safety, immunogenicity, and lot stability of the whole
cell/recombinant B subunit cholera vaccine, 2 lots manufactured in June 1991 and
February 1992 were tested in January 1995. Two oral doses of vaccine or placebo
given 2 weeks apart were given with buffer to 216 Peruvian adults and children.
Symptoms were elicited for 3 days after each dose. Serum and plasma specimens
obtained from each volunteer before vaccination and 10-14 days after the second
dose were tested for vibriocidal and anti-cholera toxin antibodies. The vaccine
was well-tolerated. Nearly half of the 100 vaccinees had pre-vaccination
vibriocidal titers > or = 1:40. Elevated titers were observed in 22% of 37
children 2-5 years of age compared with 66% of 63 vaccinees 6-65 years (P <
0.001). A > or =2-fold serum vibriocidal response was observed in 55% of 100
vaccinees and 6% of 32 placebo recipients. An elevated pre-vaccination titer (<
or =1:40) did not change the proportion of vaccinees who responded with a > or =2
fold increase in vibriocidal titer (51% versus 59%, difference not significant),
but did change the proportion responding with a > or =4-fold increase (41% versus
22%; P < 0.05). The vibriocidal seroconversion rate was lowest in children 2-5
years old despite low pre-vaccination titers. Two-fold or greater serum antitoxic
responses in IgA and IgG were observed in >90% of the vaccinees; > or =4-fold
responses were seen in 65-70% of the vaccinees with a 6-8-fold increase over
baseline. Plasma specimens were as good as sera for determining anti-toxic
antibodies by ELISA, but were less satisfactory for determining vibriocidal
antibody titers.
PMID- 10674662
TI - An accelerated schedule for tick-borne encephalitis vaccine: the American
Military experience in Bosnia.
AB - Tick-borne encephalitis (TBE) is a viral illness endemic to the Balkan region.
United States military forces were deployed to Bosnia in early 1996 as part of
Operation Joint Endeavor, a U.S.-led multinational peace-keeping operation. To
counteract the TBE threat, an inactivated, parenteral vaccine (FSME-Immun Inject;
Immuno AG, Vienna, Austria) was offered to soldiers at high risk on a volunteer
basis in an accelerated, 3-dose schedule (0, 7, and 28 days). Passive adverse
reaction surveillance was conducted on 3,981 vaccinated personnel. Paired sera
from a randomly selected group of 1,913 deployed personnel (954 who received
vaccine and 959 who were unvaccinated) were tested for antibodies to TBE by an
ELISA. Three-dose recipients demonstrated an 80% seroconversion rate (4-fold or
greater increase in anti-TBE titers). By comparison, the TBE infection rate in
the unvaccinated cohort was found to be only 0.42% (4 of 959). Only 0.18% of
vaccinees reported self-limited symptoms. An accelerated immunization schedule
appears to be an acceptable option for military personnel or travelers on short
term notice to TBE-endemic areas.
PMID- 10674663
TI - Rabies mass vaccination campaigns in Tunisia: are vaccinated dogs correctly
immunized?
AB - Among the 301 dogs vaccinated against rabies in a suburban area of Tunis, 165
were sero-surveyed for 13 months. One month after vaccination, 65% of the dogs
less than 1 year of age and 76-84% of the older dogs had significant antibody
titers. One month after annual revaccination, these percentages ranged between
92% and 100%. Puppies (less than 3 months old) responded to vaccination with no
significant interference by passive maternal immunity. Based on these
percentages, a 93% rate of protection may be expected for vaccinated dogs. This
study confirms that all dogs (even those less than 3 months of age) must be
vaccinated during mass campaigns. The expected protection conferred by locally
produced potent vaccines reaches 79-99% based on the age of the dogs. The alleged
relative inability of local dogs to respond to vaccination cannot explain the
partial success of rabies control in Tunisia.
PMID- 10674664
TI - An outbreak of West Nile fever among migrants in Kisangani, Democratic Republic
of Congo.
AB - In February 1998, an outbreak of acute febrile illness was reported from the
Kapalata military camp in Kisangani, the Democratic Republic of Congo. The
illness was characterized by an acute onset of fever associated with severe
headache, arthralgia, backache, neurologic signs, abdominal pain, and coughing.
In 1 individual, hemorrhagic manifestations were observed. The neurologic signs
included an altered level of consciousness, convulsions, and coma. Malaria was
initially suspected, but the patients showed negative blood films and failed to
respond to antimicrobial drugs. A total of 35 sera collected from the military
patients in the acute phase were tested for the presence of IgM against vector
borne agents. Serum IgM antibodies against West Nile fever virus were found in 23
patients (66%), against Chikungunya virus in 12 patients (34%), against dengue
virus in 1 patient (3%), and against Rickettsia typhi in 1 patient (3%). All sera
were negative for IgM antibody against Rift Valley fever virus, Crimean Congo
hemorrhagic fever virus, and Sindbis virus. These data suggest that infections
with West Nile fever virus have been the main cause of the outbreak.
PMID- 10674665
TI - Hepatitis C: prevalence and common genotypes among ethnic groups in Jeddah, Saudi
Arabia.
AB - The presence of antibodies to hepatitis C virus (HCV) was examined using a third
generation ELISA in 3,350 serum samples obtained from patients visiting different
outpatient clinics, preoperative patients, and women visiting for ante-natal care
at the Dr. Fakeeh hospital in Jeddah, Saudi Arabia from January to September
1998. The population included mainly Saudis, Egyptians, and Yemenis, and patients
from other Middle East and Asian countries. The prevalence of HCV infection was
5.87% among Saudis, 22.54% among Egyptians, and 2.12% among Yemenis. The
prevalence among patients from other Middle East and Asian countries were 3.38%
and 4.98%, respectively. The overall prevalence among the studied group was
6.75%. Genotyping of isolates from Saudi Arabia showed that the prevalences of
types 4, la, 1b, and 2 were 45.9%, 40.6%, 10.85%, and 2.7%, respectively.
Genotyping of isolates from Egypt showed that type 4 was the major type among
Egyptians (91.6%), while types 1a and 1b each had prevalences of 4.2%.
PMID- 10674666
TI - Application of molecular typing techniques in the 1998 dengue epidemic in
Nicaragua.
AB - This report presents the results of applying the reverse transcriptase-polymerase
chain reaction (RT-PCR) to the analysis of clinical specimens during the 1998
dengue epidemic in Nicaragua. The RT-PCR was validated through comparison with
viral isolation, resulting in a sensitivity of 100% and a specificity of 90%. In
country application of the RT-PCR permitted the rapid identification of dengue-3
virus as the cause of the epidemic at the beginning of 1998 and the detection of
the reintroduction of dengue-2 virus in the middle of the year. Nineteen isolates
of dengue-3 and one of dengue-2 were characterized using the restriction site
specific (RSS)-PCR technique. This showed that the dengue-3 strain belonged to
the "Sri Lanka" subtype and that the dengue-2 strain belonged to the "Jamaica"
subtype, both of which have been associated with hemorrhagic dengue in the
Americas. The application of these simple PCR-based strain typing methods in a
country endemic for dengue virus infections can help to characterize the
transmission dynamics of this important emerging infectious disease problem and
provide this information to local health authorities in a timely manner so that
appropriate control measures can be implemented.
PMID- 10674667
TI - Shipboard impact of a probable Norwalk virus outbreak from coastal Japan.
AB - Norwalk virus has been implicated in shipboard diarrheal disease outbreaks
throughout Asia. A large outbreak of suspected Norwalk virus was investigated on
a U.S. Naval aircraft carrier following the clinical recognition of 450 cases of
gastroenteritis over a 2-week period (September 14-28, 1997) during coastal
exercises. A random sampling of 44 cases from 450 personnel who sought medical
attention was compared with 19 controls. Junior enlisted sailors and marines
comprised 97% of all cases. There was no evidence of shipboard geographic
clustering of cases. Furthermore, no single food type was associated with illness
on the basis of comparative analysis (cases versus controls). Principal case
signs and symptoms reported included watery stools (89%), nausea (82%), and
vomiting (77%). Anecdotal reports indicated > 50% of the cases received
rehydration therapy. An absence of fever was also noted in 32% of the cases and
only 5% had blood in their stools. The mean duration of illness was 37 hr, with a
range of 3-96 hr. Laboratory findings based on reverse transcription-polymerase
chain reaction and Southern hybridization methods showed that 21 (72%) of 29
patients had evidence of the UK2 prototype of the Norwalk virus. A cross
sectional study of 131 crew members from the ships population (n = 4,200) showed
an attack rate of 44%. Attack rate is a variant of an incident rate applied to a
narrowly defined population observed for a limited period of time, such as during
an outbreak. The numerator is people who get sick and the denominator is people
(population) at risk. An extrapolation of these findings suggests as many as
1,806 sailors may have been affected during the outbreak, of which only 26% (of
the 57 outbreak related cases) where identified from sick call records. There was
no difference in the mean ages between outbreak and non-outbreak affected
crewmen, or geographic clustering based on berthing or work spaces. Outbreak
related cases reported signs and symptoms of watery-stools (79%), nausea (65%),
and vomiting (47%). The mean duration of illness was 28 hr, ranging from 2 to 96
hr. Thirty-one percent of outbreak affected cases reported a sick call visit.
Loss of work was reported by 39% of the outbreak affected population. This report
documents the epidemic potential of Norwalk virus and the associated impact on
fleet operational readiness. Additionally, that this outbreak occurred against a
background of 3 other consecutive gastroenteritis outbreaks onboard the same ship
(March 1997, February/March 1998, and June 1998), all sharing the same clinical
and epidemiologic profiles, suggests possible shipboard persistence of Norwalk
virus over time, despite periodic ship-wide disinfection efforts.
PMID- 10674668
TI - Norwalk-like virus and bacterial pathogens associated with cases of
gastroenteritis onboard a US Navy ship.
AB - Acute gastroenteritis is a potential cause of substantial morbidity in U.S.
military personnel during deployment. This study investigated the microbial
causes of diarrhea in U.S. troops on exercises in Southeast Asia aboard the
U.S.S. Germantown from March through May 1996. A total of 49 (7%) patients with
diarrhea reported to sick call during a 3-month deployment involving 721
personnel. Diarrheal samples from 49 patients were subjected to bacterial and
parasitologic examination, but sufficient samples from only 47 of 49 were
available for analysis of the presence of Norwalk-like virus (NLV). Of the 49
diarrhea cases, 10 (20.4%) appeared to be due to bacterial etiology alone, 10
(20.4%) due to bacteria and the prototype Taunton agent (TNA), 11 (22.4%) due to
TNA only, and 4 (8.0%) due to parasites. Norwalk-like virus RNA was present in 21
(45%) of 47 stool samples from the diarrhea cases, 10 with bacterial etiologies
and 11 without bacterial or parasitic etiologies. No pathogen was detected in 14
(29%) of the cases. Four of the controls showed the presence of parasitic
organisms. Of the 11 cases in which enterotoxigenic Escherichia coli was
isolated, 8 were positive for colonization factor antigen (CFA/IV), and 3 were
CFA-negative. The bacterial pathogens tested were all susceptible to gentamicin,
and furadantin, but were resistant to ceftriaxone and norfloxacin, including 75%
of the Campylobacter spp. These data support the view that the major cause of
diarrhea for troops deployed in this geographic area is most likely NLVs.
PMID- 10674669
TI - Epidemiology of the incidence of oro-facial noma: a study of cases in Dakar,
Senegal, 1981-1993.
AB - Oro-facial noma is an oral gangrene occurring in early childhood in extremely
poor areas. As many as 70-90% of those with noma die, and to date, there is no
satisfactory treatment to fight this disease. Within the context of the World
Health Organization international program against noma, a 13-year retrospective
study based on clinical records was carried out in Dakar, Senegal in an attempt
to understand the epidemiology of noma. Between 1981 and 1993, 199 cases of noma
were identified, among them; 36.7% were acute cases and 63.3% showed sequelae.
Chronic sequelae of noma were seen in patients 2-41 years of age, but the acute
phase of noma was found only in young children (77.7% in those 1-4 years of age,
maximum age = 9 years, mean age +/- SD age = 3.4 +/- 1.9 years). A total of 73.1%
of the cases with acute disease were reported in the Dakar, Diourbel and Kaolack
regions during the dry season (57.0% of the cases). The lesions of progressive
noma were localized mainly on the upper lip (42.4%) and the cheek (31.1%). A
total of 96.9% of the patients with acute diseases were had poor general health
with serious associated diseases; only 20.0% had a good vital prognosis. The
development of epidemiologic surveillance programs for noma should be a public
health priority in Senegal.
PMID- 10674670
TI - Environmental conditions favoring bat infection with Histoplasma capsulatum in
Mexican shelters.
AB - Histoplasma capsulatum was isolated from gut, lung, liver, and spleen of 17 of
208 captured bats belonging to 6 different genera and species. Three of the 17
infected bats were from the State of Guerrero and 14 were from the State of
Morelos. All were adult bats: 6 males (1 Pteronotus parnellii, 2 Natalus
stramineus, 2 Artibeus hirsutus, and 1 Leptonycteris nivalis) and 11 females (1
Myotis californicus, 1 Mormoops megalophylla, 8 A. hirsutus, and 1 L. nivalis).
High rates of bat infection with H. capsulatum were found in the monitored sites
of the State of Morelos. Histoplasma infection of N. stramineus, A. hirsutus, and
L. nivalis should be considered as the first records in the world. The fungus
isolated from infected bats was identified by its typical mycelial-phase
morphology and by its yeast-phase conversion. Exoantigen production confirmed the
fungal identification by the presence of specific precipitation lines in double
immunodiffusion assays using human immune serum. Histopathologic studies showed
intracellular yeast-like cells compatible with H. capsulatum yeast-phase in
tissues of several bats, especially in pulmonary (intra-alveolar and septal)
macrophages, with none or minimal tissue reaction. In contrast to past reports,
present data support a high risk of bat infection with H. capsulatum in Mexican
cave environments.
PMID- 10674671
TI - Infectious and tropical diseases in Oman: a review.
AB - Oman is generally hot and dry, but the Salalah region in southern Dhofar province
is relatively cool and rainy during the summer monsoon, and has a distinctive
pattern of infection. Important, notifiable infections in Oman include
tuberculosis, brucellosis (endemic in Dhofar), acute gastroenteritis, and viral
hepatitis: 4.9% of the adults are seropositive for hepatitis B surface antigen
and approximately 1.2% for hepatitis C virus. Infection with human
immunodeficiency virus is uncommon, and leprosy, rabies, and Crimean-Congo
hemorrhagic fever are rare. Between 1990 and 1998, the incidence of malaria,
(>70% due to Plasmodium falciparum) decreased from 32,700 to 882 cases. Cutaneous
and visceral leishmaniasis (caused by Leishmania tropica and L. infantum,
respectively) and Bancroftian filariasis occur sporadically. Intestinal
parasitism ranges from 17% to 42% in different populations. A solitary focus of
schistosomiasis mansoni in Dhofar has been eradicated. There are major programs
for the elimination of tuberculosis, leprosy, and malaria, and to control
brucellosis, leishmaniasis, sexually transmitted diseases, trachoma, acute
respiratory infection in children, and diarrheal diseases. The Expanded Program
on Immunization was introduced in 1981: diphtheria, neonatal tetanus, and
probably poliomyelitis have been eliminated.
PMID- 10674672
TI - Factors influencing resistance to reinfection with Plasmodium falciparum.
AB - A treatment-reinfection study design was used to investigate the relationships
between host immunologic and/or genetic factors and resistance to reinfection
with Plasmodium falciparum. Sixty-one children in Gabon were enrolled in a cross
sectional study to measure the prevalence of each human plasmodial species. All
were given amodiaquine for radical cure of parasites, and 40 were subsequently
followed-up for 30 weeks. Successive blood smears were examined to measure the
delay of reappearance in blood of asexual stages of P. falciparum parasites.
Presence of infection during the cross-sectional survey was associated with male
sex, non-deficient glucose-6-phosphate dehydrogenase activity, plasma interleukin
10 level, and anti-LSA-Rep antibody concentration. Resistance to reinfection was
related to the presence of anti-LSA-J antibodies, and the absence of anti-LSA-Rep
antibodies. Moreover, P. malariae-infected subjects were usually co-infected with
P. falciparum, and were also more rapidly reinfected with P. falciparum after
treatment, compared with those without P. malariae infection.
PMID- 10674673
TI - Analysis of repeated hemoglobin measures in full-term, normal birth weight Kenyan
children between birth and four years of age. III. The Asemobo Bay Cohort
Project.
AB - Anemia is an important public health problem. During very early childhood
numerous factors affect hemoglobin (Hb) concentration over time, making single
cross-sectional measurements difficult to interpret when studying the natural
history of anemia or evaluating anemia control strategies. We analyzed repeated
Hb measures contributed by 942 Kenyan children between birth and 48 months of
life using a mixed effects model, with a regression spline used to describe the
population mean Hb profile, and random intercepts and slopes and first-order
autoregressive correlation structure to accommodate the within-individual
correlation among the repeated Hb measures. The approach facilitates the study of
time-stationary and time-varying covariates that influence Hb in early life. The
fitted mean Hb profile obtained from the analytic model is consistent with the
observed mean Hb of the study population. Village of residence was associated
with greatest difference in mean Hb at time of birth (16 versus 19 g/dL; P <
0.0001). Monthly weight-for-age was also associated with mean Hb after 3 months
of age. This is the first description of an analysis strategy specifically for
repeated Hb measures collected in a longitudinal field study in Africa. The
strategy will facilitate improved study of time-varying covariates thought to
influence pediatric anemia.
PMID- 10674674
TI - Kala-azar in a high transmission focus: an ethnic and geographic dimension.
AB - In 1994-1996, we studied a group of 58 game wardens stationed in an area known to
be highly endemic for visceral leishmaniasis (kala-azar) for evidence of
infection with Leishmania donovani. Leishmania DNA was detected by the polymerase
chain reaction in the peripheral blood of cases of active kala-azar, former
patients with visceral leishmaniasis, patients, and asymptomatic subjects. Using
the cloned antigen rk39, antibodies were detected in 44.2% of the game wardens
while leishmanin skin test result was positive in 77% of our sample. It was shown
that certain tribes from northern Sudan were more likely to develop subclinical
infections, while those of the Baria tribe from southern Sudan and those of the
Nuba tribe from western Sudan were more likely to develop visceral leishmaniasis.
Whether this is due to genetic factors or previous exposure to Leishmania
parasites remains to be elucidated.
PMID- 10674675
TI - Epidemiologic aspects of American visceral leishmaniasis in an endemic focus in
Eastern Venezuela.
AB - An endemic focus of American visceral leishmaniasis (AVL) in eastern Venezuela
has been evaluated in terms of patients (n = 48), immunologic reactivity to
Leishmania in household contacts (n = 187) and neighborhood controls (n = 170),
detection of Leishmania (L. donovani complex) in dogs and wild animals by the
polymerase chain reaction (PCR) and characteristics of the sandfly population.
The male:female ratio of patients was 1.18:1; 89.6% were < or =12 years old.
Serologic reactivity was significantly higher in household contacts than in
controls (P = 0.0008), as was the size of leishmanin reactions in contacts < or
=10 years of age (P = 0.0141). Leishmania donovani complex-specific PCRs were
positive in dogs, an opossum (Didelphis marsupialis), and a black rat (Rattus
rattus). Lutzomyia longipalpis and Lu. evansi, both implicated in the
transmission of AVL, were identified among the 386 sand flies examined. These
observations provide the bases for an active control program as well as further
studies of reservoirs and vector-host relationships in this area.
PMID- 10674676
TI - Geographic distribution and epidemiology of Oesophagostomum bifurcum and hookworm
infections in humans in Togo.
AB - In contrast to the rest of the world, infections with Oesophagostomum bifurcum
are commonly found in humans in northern Togo and Ghana. In addition, infections
with hookworm are endemic in this region. In the present study, a detailed map of
the geographic distribution of O. bifurcum and hookworm infections in northern
Togo was made. There were a number of foci with high prevalence of infection with
O. bifurcum. All the villages examined were infected with hookworm, and the
distribution was quite patchy. Women were infected with O. bifurcum more often
than men, while infections with hookworm were more prevalent in men than in
women. The prevalence and intensity of infection with both parasites were clearly
age-dependent. We estimate that more than a 100,000 people in Togo are infected
with O. bifurcum and more than 230,000 are infected with hookworm.
PMID- 10674677
TI - Use of polymerase chain reaction for accurate follow-up of Loa loa experimental
infection in Mandrillus sphinx.
AB - Mandrills (Mandrillus sphinx) experimentally infected with human Loa loa usually
remain microfilaremic for a long period of time. Nevertheless some control their
microfilaremia while still harboring adults worms, and therefore become occult
infected. A nested polymerase chain reaction (PCR) assay, targeted on the repeat
3 region of the gene coding for the L. loa 15-kD protein (15r3-PCR), has been
evaluated in mandrills infected with third-stage larvae (L3) of L. loa. The
results of this assay were negative during the prepatency period (4 months after
inoculation), but became positive when microfilariae appeared in the blood, and
remained positive in all mandrills, even in those that became amicrofilaremic.
These results show that the positivity of the 15r3-PCR assay is linked to the
appearance of microfilariae in peripheral blood and demonstrated that L. loa
specific DNA can be detected in blood from occult-infected mandrills.
PMID- 10674678
TI - Response of cutaneous leishmaniasis (chiclero's ulcer) to treatment with
meglumine antimoniate in Southeast Mexico.
AB - Cutaneous leishmaniasis, known as chiclero's ulcer in southeastern Mexico, is
characterized by a predominantly single, painless, ulcerated lesion, without
lymphangitis or adenopathy. When located on the ear, it tends to become chronic,
causing destruction of the pinna and disfigurement. It is caused predominantly by
Leishmania (L.) mexicana. Although pentavalent antimonials (Sb5+) are the
mainstay of leishmanial therapy and have been used for more than 50 years, dosage
regimens have been repeatedly modified and the best one has not been fully
identified. The main purpose of the present study was to investigate the response
of chiclero's ulcer to treatment with meglumine antimoniate. One hundred five
patients were treated with meglumine antimoniate at a daily dose of 1 ampule per
day (425 mg of Sb5+) until healing. The lesions healed after a mean of 25 days
(range = 5-60 days).
PMID- 10674679
TI - No evidence of cardiotoxicity during antimalarial treatment with artemether
lumefantrine.
AB - Artemether-lumefantrine is a new fixed antimalarial combination effective against
multidrug-resistant falciparum malaria. A prospective electrocardiographic study
was conducted in 150 patients receiving artemetherlumefantrine and 50 treated
with artesunate-mefloquine. There was no evidence for clinically significant
changes in the electrocardiographic intervals and in particular no relationship
between plasma concentrations of lumefantrine and QTc prolongation. Artemether
lumefantrine does not have significant cardiac effects at therapeutic doses.
PMID- 10674680
TI - Assessment of therapeutic response of Plasmodium falciparum to chloroquine and
sulfadoxine-pyrimethamine in an area of low malaria transmission in Colombia.
AB - Although chloroquine (CQ) resistance was first reported in Colombia in 1961 and
sulfadoxine-pyrimethamine (SP) resistance in 1981, the frequency of treatment
failures to these drugs in Colombia is unclear. A modified World Health
Organization 14-day in vivo drug efficacy test for uncomplicated Plasmodium
falciparum malaria in areas with intense malaria transmission was adapted to
reflect the clinical and epidemiologic features of a low-intensity malaria
transmission area in the Pacific Coast Region of Colombia. Patients > or =1 year
of age with a parasite density > or =1,000 asexual parasites per microliter were
enrolled in this study. Forty-four percent (24 of 54) of the CQ-treated patients
were therapeutic failures, including 7 early treatment failures (ETFs) and 17
late treatment failures (LTFs). Four (6%) of 67 SP-treated patients were
therapeutic failures (2 ETFs and 2 LTFs). Therapeutic failure in the CQ-treated
group was associated with an age <15 years old (P < 0.01), but was not associated
with initial parasite density, the presence of CQ or sulfa-containing drugs in
urine, or a history of malaria. The high level of therapeutic failures to CQ
detected in this study underscores the need and importance of drug efficacy
evaluation in the development of a rational national antimalarial drug policy.
The relatively low level of therapeutic failures to SP compared with other South
American countries raises further questions regarding factors that might have
prevented the rapid development of in vivo resistance to this drug combination.
PMID- 10674681
TI - Efficacy of primaquine regimens for primaquine-resistant Plasmodium vivax malaria
in Thailand.
AB - To define the current efficacy of Fansidar (F. Hoffmann-La Roche Ltd., Basel
Switzerland) (pyrimethamine and sulfadoxine), primaquine in a high dose, and
artesunate for treating acute Plasmodium vivax malaria, we conducted a
comparative clinical trial of these 3 drugs in an open-label study. Patients (15
65 years old) were assigned to 1 of 4 treatments regimens in a serial order.
Ninety percent of the patients were infected at Thailand-Myanmar border. Patients
in group I (n = 23) received Fansidar (3 tablets, 75 mg of pyrimethamine and
1,500 mg of sulfadoxine, a single dose on the first day), group II (n = 23)
received Fansidar (3 tablets, 75 mg of pyrimethamine and 1,500 mg of sulfadoxine,
a single dose on the first day) and then received primaquine (30 mg a day for 14
days), group III (n = 23) received primaquine (30 mg a day for 14 days), and
group IV (n = 23) received artesunate (200 mg once a day for 3 days) and then
primaquine (30 mg a day for 14 days). Cure rates on day 28 of follow-up were 40%,
100%, 100%, and 100% in groups I, II, II, and IV, respectively. There were 4 and
5 patients in group I showing post-treatment reappearance of parasitemia at < or
= 16 days and between 17 and 28 days, respectively. Patients in the other 3
groups showed negative parasitemias within 7 days after treatment. Artesunate
plus primaquine (group IV) cleared parasitemia faster than the other 3 regimens.
There is a high proportion of ineffectiveness of Fansidar for treatment of P.
vivax malaria and it should be no longer used for treatment of P. vivax malaria
acquired at the Thailand-Myanmar border. A high dose of primaquine is safe and
effective in the treatment of P. vivax malaria during the 28-day follow-up
period.
PMID- 10674682
TI - Plasmodium falciparum parasites in French Guiana: limited genetic diversity and
high selfing rate.
AB - The genetic characteristics of Plasmodium falciparum isolates collected in French
Guiana, where malaria transmission is low and occurs in isolated foci, were
studied. Blood samples were collected from 142 patients with symptomatic malaria
and typed using a polymerase chain reaction-based strategy for merozoite surface
protein-(MSP-1) block 2, the MSP-2 central domain, and glutamate-rich protein
(GLURP) repeat domain polymorphism. This showed that the parasite population
circulating in French Guiana presented a limited number of allelic forms (4, 2,
and 3 for MSP-1 block 2, MSP-1, and GLURP, respectively) and a small number of
mixed infections, contrasting with the large genetic diversity of parasite
populations and infection complexity reported for Africa, Asia, and other parts
of South America. Two groups of isolates displaying identical 3 loci allele
combinations were further studied for the Pf332 antigen, histidine-rich protein
1, thrombospondin-related anonymous protein, and Pf60 multigene family
polymorphism. Within each group, most isolates were identical for all markers
tested. This suggests a high rate of self-fertilization of P. falciparum
parasites in French Guiana, resulting in homogenization of the population. The
implications of these findings for malaria control in areas of low endemicity are
discussed.
PMID- 10674683
TI - Genetic structure and phylogenetic relationships of Colombian Trypanosoma cruzi
populations as determined by schizodeme and isoenzyme markers.
AB - Twenty-four Trypanosoma cruzi stocks isolated from vectors and from human and
Didelphis marsupialis hosts from highly separated sylvatic localities in Colombia
were characterized by isoenzyme and schizodeme analyses. The stocks were
collected primarily from sylvatic ecotopes representing areas of low, moderate,
and high endemicity for Chagas' diseases in Colombia. Parasites were
characterized mainly by schizodeme analysis with the restriction enzyme Eco RI
and the isoenzyme analysis was performed at 10 genetic loci. These analyses
demonstrated an agreement between the classifications based on the isoenzyme
analysis and on the restriction fragment length polymorphism patterns obtained
with the Colombian stocks. There is clear evidence of demic subdivision between
the eastern (E) and western (W) stocks separated by the Andean Mountains and
Magdalena River, which is likely due to the geographic isolation generated by
these topographic features. Heterozygosity estimates indicate that the E group
could be more ancient than the W group. As was postulated in a previous study,
these results are also compatible with the existence of a clonal population
structure in Colombian sylvatic T. cruzi. Evidence presented here failed to
demonstrate a correlation between the degree of endemy and genetic clustering.
Finally, schizodeme and isoenzymatic analyses comparing Colombian T. cruzi stocks
with others from Chile confirm that Colombian isolates are genetically related to
zymodeme 1 and distant from zymodeme 2.
PMID- 10674684
TI - Detection and genetic relationship of dengue virus sequences in seventeen-year
old paraffin-embedded samples from Cuba.
AB - This study describes the use of the reverse transcriptase-polymerase chain
reaction (RT-PCR) to generate dengue 2 amplicons from paraffin-embedded autopsy
tissues collected in Cuba 17 years ago. The presumptive diagnoses had been made
only by clinical evolution without serologic confirmation. This study confirms
once again that dengue 2 virus was directly associated with the fatal cases in
children and illustrates the potential of the RT-PCR for retrospective diagnosis
of dengue cases 17 years after death. A close similarity in the genomic sequences
of the dengue 2 RNA detected in tissue samples from fatal cases and those dengue
2 Cuban strains that had been previously investigated confirms the appropriate
genomic classification of the etiologic agent associated with the 1981 dengue
hemorrhagic fever Cuban epidemic.
PMID- 10674685
TI - Short report: microsatellite sequences as markers for population genetic studies
of the mosquito Aedes aegypti, the vector of dengue viruses.
AB - We report the isolation of microsatellites from an enriched library of genomic
repeated sequences, using a biotin-labeled oligonucleotide bound to streptavidin
coated magnetic particles. Four microsatellites were obtained from a partial
library of 120 recombinant clones. This more efficient and rapid method to obtain
these specific repeated sequences is preferred to the conventional isolation
procedure based on the construction of a genomic library. Microsatellite markers
would be promising molecular tools for the study of genetic variability of
mosquito populations. Analyses of genetic structure and gene flow would provide
information on the distance, direction and rate of dispersal of genes in Aedes
aegypti populations. Knowledge on gene dispersal patterns is required to develop
vector control strategies.
PMID- 10674686
TI - Occurrence of sibling species of Lutzomyia longipalpis (Diptera: Psychodidae) in
Venezuela: first evidence from reproductively isolated sympatric populations.
AB - The delimitation of cryptic species within the main vector of the American
visceral leishmaniasis, Lutzomyia longipalpis, remains a topic of controversy. An
analysis of genetic variability based on 8 enzymatic loci revealed fixed
differences in 2 diagnostic loci, adenylate kinase (Ak) and hexokinase (Hk),
between sympatric and allopatric populations at 4 localities in Venezuela. The
absence of heterozygotes for these 2 loci within 1 locality indicates, for the
first time, the presence of 2 sympatric reproductively isolated populations or
cryptic species within L. longipalpis. Significant differences were also detected
between these cryptic species in the allele frequencies of glucose-6-phosphate
isomerase (Gpi) and malate dehydrogenase, decarboxylating (Me). One species
showed mean heterozygosities that ranged between 6.6% and 6.7%, with 1.6-1.9
alleles detected per locus, while the other had mean heterozygosities that ranged
from 4.3% to 6.3%, with 1.3-1.6 alleles per locus. Comparisons of isozyme
profiles with published data suggests that 1 species is similar to the L.
longipalpis described in Colombian and Brazilian populations, whereas the other
has not been previously reported.
PMID- 10674687
TI - Spatial distribution and habitat characterization of anopheline mosquito larvae
in Western Kenya.
AB - Studies were conducted to characterize larval habitats of anopheline mosquitoes
and to analyze spatial heterogeneity of mosquito species in the Suba District of
western Kenya. A total of 128 aquatic habitats containing mosquito larvae were
sampled, and 2,209 anopheline and 10,538 culicine larvae were collected. The
habitats were characterized based on size, pH, distance to the nearest house and
to the shore of Lake Victoria, coverage of canopy, surface debris, algae and
emergent plants, turbidity, substrate, and habitat types. Microscopic
identification of third- and fourth-instar anopheline larvae did not yield any
Anopheles funestus or other anophelines. A total of 829 An. gambiae s.l. larvae
from all habitats were analyzed further by rDNA-polymerase chain reaction to
identify individual species within the An. gambiae species complex. Overall, An.
arabiensis was the predominant species (63.4%), and An. gambiae was less common
(31.4%). The species composition of An. gambiae s.l. varied significantly among
the sampling sites throughout Suba District. The larval habitats in the southern
area of the district had a higher proportion of An. gambiae than in the northern
area. Multiple logistic analysis did not detect any significant association
between the occurrence of anopheline larvae and habitat variables, and principal
component analysis did not identify key environmental factors associated with the
abundance of An. gambiae. However, significant spatial heterogeneity in the
relative abundance of An. gambiae within the Suba district was detected. When the
effect of larval habitat locality was considered in the analysis, we found that
the distance to the nearest house and substrate type were significantly
associated with the relative abundance of An. gambiae. Future studies integrating
detailed water chemistry analysis, remote sensing technology, and the ecology of
predators may be required to further elucidate the mechanisms underlying the
observed spatial variation of anopheline larval distribution.
PMID- 10674688
TI - Short report: treatment of snake envenomations by a new polyvalent antivenom
composed of highly purified F(ab)2: results of a clinical trial in northern
Cameroon.
AB - A clinical trial was conducted in 2 health centers in northern Cameroon to assess
the safety and efficacy of a new polyvalent antivenom composed of highly purified
and pasteurized F(ab')2 (FAV-Africa). Forty-six patients with objective signs of
envenomation, including 67% with hemorrhage, were included in the study. Each
patient received at least 20 ml of FAV-Africa by direct, slow intravenous
injection; 172 10-ml ampules were administered. All patients were clinically
cured after treatment. Two patients (4.3%) showed minor immediate adverse events
that may have been related to FAV-Africa (induration, light-headedness); no other
treatment-related adverse event occurred. No patient had serum sickness. This
trial confirms the safety of FAV-Africa administered by intravenous injection and
its efficacy in the treatment of snake envenomations in sub-Saharan Africa.
PMID- 10674689
TI - The International Health Program: the fifteen-year experience with Yale
University's Internal Medicine Residency Program.
AB - The purpose of this study was to assess the impact of international health
electives on physicians-in-training. A retrospective study was conducted using an
anonymous, self-administered mailed survey to internal medicine residents who
trained at Yale from 1982 to 1996 based on their experience with our
International Health Program (IHP). The response rate was 61%, with 96 completed
surveys in the participant group and 96 completed surveys in the nonparticipant
group. Participants were more likely than nonparticipants to care for patients on
public assistance (77 versus 49; P < 0.001) and immigrant patients (41 versus 23;
P = 0.006). Among residents who changed their career plans, participants (22)
were more likely than nonparticipants (14) to switch from subspecialty medicine
to general medicine (P = 0.02). Participants were significantly more likely to
have a positive view of health care delivery in developing countries. Compared
with nonparticipants (64), IHP participants (74) believed that the physical
examination is under-used by physicians from the United States as a diagnostic
skill (P = 0.03). International health experiences appeared to have an important
impact on the decisions and attitudes of residents.
PMID- 10674690
TI - Call for 'radical overhaul' of meat hygiene arrangements.
PMID- 10674691
TI - Therapeutic efficacy of water-soluble lincomycin-spectinomycin powder against
porcine proliferation enteropathy in a European field study.
AB - Controlled clinical trials to a standardised protocol were conducted into the
effect of a water-soluble antibiotic on proliferative enteropathy and its
causative agent (Lawsonia intracellularis) on commercial pig farms at six sites
in four European countries. Clinical signs of the disease and L intracellularis
specific polymerase chain reaction (PCR)-positive pigs were detected in pens of
six- to 12-week-old pigs (weighing 5 to 55 kg) immediately before each trial.
Matched pens of randomised pigs were either left unmedicated (32 to 59 pigs per
trial), or medicated orally with 10 mg/kg of a water-soluble combination of
lincomycin and spectinomycin powder (21 and 42 mg, respectively, of antibiotic
activity per litre) for either seven days (33 to 61 pigs per trial), or 14 days
(33 to 61 pigs per trial), delivered via the drinking water. Investigators did
not know which pens received which treatment In most of the affected pigs in each
trial, diarrhoea due to L intracellularis resolved within three to seven days
after the medication began, whereas most unmedicated pigs remained diarrhoeic for
at least 10 days. On average the medicated pigs gained more weight than the
unmedicated pigs over the 21-day trial period (P=0.01). In two trials, the
absence of L intracellularis after the treatment ended was confirmed by the PCR.
PMID- 10674692
TI - Survey of the effectiveness of stunning procedures used in Spanish pig abattoirs.
AB - Two pig abattoirs (A and B) equipped with an automated head-only and head-to
chest electrical stunning system, and two (C and D) equipped with a manual carbon
dioxide stunning system, were evaluated to compare the effectiveness of stunning
in a total of 10,454 pigs slaughtered under commercial conditions. In the
abattoirs with the electrical stunning system, the percentage of animals that
responded to a nose prick was significantly lower (P<0.05) in abattoir B, where a
higher current intensity was used (P<0.05), than in abattoir A. No righting
reflex was observed in the electrically stunned pigs. In the abattoirs with the
carbon dioxide stunning system, the percentage of animals that responded to a
nose prick and showed a righting reflex was significantly lower (P<0.05) in
abattoir C, where the duration of the carbon dioxide cycle was longer and the
interval between discharge from the system to sticking was shorter (P<0.05), than
in D. Comparing the electrical and carbon dioxide stunning systems, the pigs
stunned with carbon dioxide were significantly more responsive to a nose prick
(P<0.05) and 25 per cent of them showed a righting reflex. Under the conditions
of the study the fully automated head-only stunning with additional chest
electrodes appeared to be more effective and less susceptible to incorrect
handling than the manual carbon dioxide stunning system.
PMID- 10674694
TI - Phytophotodermatitis in pigs exposed to parsley (Petroselinum crispum).
PMID- 10674693
TI - Evidence of Muscovy duck parvovirus in Muscovy ducklings in California.
AB - Muscovy duck parvovirus (MDPV) has been demonstrated in tissue samples from one-
to four-week-old commercially reared Muscovy ducks that were weak, unable to walk
and had a high mortality rate. On postmortem examination, the thigh and leg
muscles, and the myocardium were found to be pale, and there was a fibrinous
exudate on the capsule of the liver, and ascites. The parvovirus was isolated in
embryonated Muscovy duck eggs and visualised by negative stain electron
microscopy, detected by polymerase chain reaction (PCR) directly from the
tissues, and antibodies to it were detected by immunoelectron microscopy, ELISA
and immunofluorescence. In addition, the PCR products obtained that represented
1625 bp (74 per cent) of the capsid vP1 gene, including a hypervariable region
between Derzsy's disease virus or goose parvovirus and MDPV, were sequenced and
shown to be 100 per cent homologous with the MDPV 89384 reference strain, but
only 82.3 per cent homologous with Derzsy's disease virus.
PMID- 10674695
TI - Efficiency of Western blotting for the specific immunodetection of proteinase K
resistant prion protein in BSE diagnosis in France.
PMID- 10674696
TI - Emergence of resistance to fluoroquinolones among bacteria causing infections in
food animals in Denmark.
PMID- 10674697
TI - Hemiovariosalpingectomy in a loggerhead sea turtle (Caretta caretta).
PMID- 10674698
TI - Health status of dairy herds in organic farming.
PMID- 10674699
TI - Corynebacterium renale infection in calves.
PMID- 10674700
TI - Postweaning multisystemic wasting syndrome of pigs.
PMID- 10674701
TI - Society of Veterinary Assistants.
PMID- 10674703
TI - Reindeer concerns
PMID- 10674702
TI - Reindeer concerns.
PMID- 10674704
TI - Reindeer concerns
PMID- 10674705
TI - Intravitreal administration of antisense oligonucleotides: potential of liposomal
delivery.
AB - Antisense oligonucleotides are short synthetic fragments of genes that are able
to inhibit gene expression after being internalized by cells. They can therefore
be used as antiviral compounds particularly, for the treatment of ocular viral
infections (i.e. Herpes simplex virus or Cytomegalovirus, CMV). Antisense
oligonucleotides are however poorly stable in biological fluids and their
intracellular penetration is limited. Although oligonucleotides are now currently
used in therapeutics for the treatment of CMV by intravitreal injection
(Vitravene) their main drawbacks impose to repeat the number of administrations
which can be very harmful and damaging. A system that is able to permit a
protection of oligonucleotides against degradation and their slow delivery into
the vitreous would be more favorable for improving patient compliance. The use of
liposomes for intravitreal administration can be very promising since these lipid
vesicles are able to protect oligonucleotides against degradation by nucleases
and they allow to increase the retention time of many drugs in the vitreous. In
this review, the potentialities of liposomes for the intravitreal delivery of
oligonucleotides will be discussed.
PMID- 10674706
TI - Development and clinical assessment of an artificial cornea.
AB - Keratoprosthesis research has been a gradual, rather fragmentary process with
advances being made by isolated groups of researchers. This has arisen partly
because of poor funding in the area; research groups which have achieved
commercial support have often had constraints upon the full disclosure of their
findings. Despite these difficulties there has been real progress over the last
decade by several independent groups. This article concentrates upon our own
development of a hydrogel core-and-skirt keratoprosthesis, the Chirila KPro, in
order to illustrate the scientific and clinical problems common to
keratoprosthesis research. Pilot data from a clinical trial is presented and the
priorities for future research are discussed.
PMID- 10674707
TI - Role of Schwann cells in retinal ganglion cell axon regeneration.
AB - It is a well known fact that the injured PNS can successfully regenerate, on the
other hand, the CNS such as retinal ganglion cell (RGC) axons of adult mammals is
incapable of regeneration. After injury, RGC axons rapidly degenerate and most
cell bodies go through the process of cell death, while glial cells at the site
of injury undergo a series of responses which underlie the so-called glial scar
formation. However, it has become apparent that RGCs do have an intrinsic
capacity to regenerate which can be elicited by experimental replacement of the
inhibitory glial environment with a permissive peripheral nerve milieu. Schwann
cells are a major component of the PNS and play a role in regeneration, by
producing various kinds of functional substances such as diffusible neurotrophic
factors, extracellular matrix and cell adhesion molecules. RGC regeneration can
be induced by cooperation of these substances. The contact of RGC axons to
Schwann cells based upon the structural and molecular linkages seems to be
indispensable for the stable and successful regeneration. In addition to cell
adhesion molecules such as NCAM and L1, data from our laboratory show that
Schwann cells utilize short focal tight junctions to provide morphological
stabilization of the contact with the elongating axon, as well as a small scale
of gap junctions to facilitate traffic of substances between them. Moreover, our
results show that modifications of functional properties in neighboring glial
cells of optic nerve are induced by transplantation of Schwann cells. Astrocytes
usually considered to form a glial scar guide the regenerating axons in
cooperation with Schwann cells. A decrease of the oligodendrocyte marker O4 and
migration of ED-1 positive macrophages is observed within the optic nerve stump.
Accordingly, RGC regeneration is not a simple phenomenon of axonal elongation on
the Schwann cell membrane, but is based on direct and dynamic communication
between the axon and the Schwann cell, and is also accompanied by changes and
responses among the glial cell populations, which may be partly associated with
the mechanisms of optic nerve regeneration.
PMID- 10674708
TI - Oxidative damage and protection of the RPE.
AB - This review provides a model for the role of oxidative stress in the etiology of
age-related macular degeneration (AMD). Epidemiological studies of diet,
environmental and behavioral risk factors suggest that oxidative stress is a
contributing factor of AMD. Pathological studies indicate that damage to the
retinal pigment epithelium (RPE) is an early event in AMD. In vitro studies show
that oxidant treated RPE cells undergo apoptosis, a possible mechanism by which
RPE cells are lost during early phase of AMD. The main target of oxidative injury
seems to be mitochondria, an organelle known to accumulate genomic damages in
other postmitotic tissues during aging. The thiol antioxidant GSH and its amino
acid precursors protect RPE cells from oxidant-induced apoptosis. Similar
protection occurs with dietary enzyme inducers which increase GSH synthesis.
These results indicate that therapeutic or nutritional intervention to enhance
the GSH antioxidant capacity of RPE may provide an effective way to prevent or
treat AMD.
PMID- 10674709
TI - Stem cells and differentiation stages in the limbo-corneal epithelium.
PMID- 10674710
TI - Molecular genetics of hepatic methionine adenosyltransferase deficiency.
AB - Hepatic methionine adenosyltransferase (MAT) deficiency is caused by mutations in
the human MAT1A gene that abolish or reduce hepatic MAT activity that catalyzes
the synthesis of S-adenosylmethionine from methionine and ATP. This genetic
disorder is characterized by isolated persistent hypermethioninemia in the
absence of cystathionine beta-synthase deficiency, tyrosinemia, or liver disease.
Depending on the nature of the genetic defect, hepatic MAT deficiency can be
transmitted either as an autosomal recessive or dominant trait. Genetic analyses
have revealed that mutations identified in the MAT1A gene only partially
inactivate enzymatic activity, which is consistent with the fact that most
hepatic MAT-deficient individuals are clinically well. Two hypermethioninemic
individuals with null MAT1A mutations have developed neurological problems,
including brain demyelination, although this correlation is by no means absolute.
Presently, it is recommended that a DNA-based diagnosis should be performed for
isolated hypermethioninemic individuals with unusually high plasma methionine
levels to assess if therapy aimed at the prevention of neurological
manifestations is warranted.
PMID- 10674711
TI - Pharmacokinetics of selective serotonin reuptake inhibitors.
AB - The five selective serotonin reuptake inhibitors (SSRIs), fluoxetine,
fluvoxamine, paroxetine, sertraline, and citalopram, have similar antidepressant
efficacy and a similar side effect profile. They differ, however, in their
pharmacokinetic properties. Under steady-state concentrations, their half-lives
range between 1 and 4 days for fluoxetine (7 and 15 days for norfluoxetine) and
between 21 (paroxetine) and 36 (citalopram) hr for the other SSRIs. Sertraline
and citalopram show linear and fluoxetine, fluvoxamine, and paroxetine nonlinear
pharmacokinetics. SSRIs underlie an extensive metabolism with high
interindividual variability, whereby cytochrome P450 (CYP) isoenzymes play a
major role. Therefore, resulting blood concentrations are highly variable between
individuals. Except for N-demethylated fluoxetine, metabolites of SSRIs do not
contribute to clinical actions. Therapeutically effective blood concentrations
are unclear so far, although there is evidence for minimal effective and upper
threshold concentrations that should not be exceeded. Paroxetine and, to a lesser
degree, fluoxetine and norfluoxetine are potent inhibitors of CYP2D6 and
fluvoxamine of CYP1A2 and CYP2C19. This can give rise to drug-drug interactions
that may have no effect, lead to intoxication, or improve the therapeutic
response. These different pharmacokinetic properties of the five SSRIs,
especially their drug-drug interaction potential, should be considered when
selecting a distinct SSRI for treatment of depression or other disorders with a
suggested dysfunction of the serotonergic system in the brain.
PMID- 10674712
TI - Cardiotrophin-1: a novel cytokine and its effects in the heart and other tissues.
AB - Cardiotrophin-1 (CT-1) originally was discovered as a factor that can induce
hypertrophy of cardiac myocytes, both in vitro and in vivo. Subsequently, CT-1
has been shown to have a wide variety of different effects on cardiac and
noncardiac, cells including the ability to stimulate the survival of both cardiac
and neuronal cells. Like other members of the interleukin-6 family of cytokines,
CT-1 stimulates both the p42/p44 mitogen-activated protein kinase pathway and the
Janus-activated kinase/signal transducers and activators of transcription
pathway. Interestingly, whilst activation of the p42/p44 mitogen-activated
protein kinase pathway is necessary for the survival-promoting effects of CT-1 in
cardiac cells, it is not required for its hypertrophic effect, which is likely to
involve activation of the Janus-activated kinase/signal transducer and activator
of transcription-3 pathway. CT-1, therefore, may be of use as a novel
cardioprotective agent, particularly if its hypertrophic effect can be
specifically inhibited.
PMID- 10674713
TI - Molecular aspects of ATP-sensitive K+ channels in the cardiovascular system and
K+ channel openers.
AB - ATP-sensitive K+ (K(ATP)) channels are inhibited by intracellular ATP (ATPi) and
activated by intracellular nucleoside diphosphates and thus, provide a link
between cellular metabolism and excitability. K(ATP) channels are widely
distributed in various tissues and may be associated with diverse cellular
functions. In the heart, the K(ATP) channel appears to be activated during
ischemic or hypoxic conditions, and may be responsible for the increase of K+
efflux and shortening of the action potential duration. Therefore, opening of
this channel may result in cardioprotective, as well as proarrhythmic, effects.
These channels are clearly heterogeneous. The cardiac K(ATP) channel is the
prototype of K(ATP) channels possessing approximately 80 pS of single-channel
conductance in the presence of approximately 150 mM extracellular K+ and opens
spontaneously in the absence of ATPi. A vascular K(ATP) channel called a
nucleoside diphosphate-dependent K+ (K(NDP)) channel exhibits properties
significantly different from those of the cardiac K(ATP) channel. The K(NDP)
channel has the single-channel conductance of approximately 30-40 pS in the
presence of approximately 150 mM extracellular K+, is closed in the absence of
ATPi, and requires intracellular nucleoside di- or triphosphates, including ATPi
to open. Nevertheless, K(ATP) and K(NDP) channels are both activated by K+
channel openers, including pinacidil and nicorandil, and inhibited by
sulfonylurea derivatives such as glibenclamide. It recently was found that the
cardiac K(ATP) channel is composed of a sulfonylurea receptor (SUR)2A and a two
transmembrane-type K+ channel subunit Kir6.2, while the vascular K(NDP) channel
may be the complex of SUR2B and Kir6.1. By precisely comparing the functional
properties of the SUR2A/Kir6.2 and the SUR2B/Kir6.1 channels, we shall show that
the single-channel characteristics and pharmacological properties of SUR/Kir6.0
channels are determined by Kir and SUR subunits, respectively, while responses to
intracellular nucleotides are determined by both SUR and Kir subunits.
PMID- 10674714
TI - My journey from wool research to insulin.
AB - This paper is an autobiographical study of the author's early work on the
chemical cross-linking of proteins as well as on oligomer and peptide synthesis
from 1949 in Heidelberg until the synthesis of insulin in 1963 in Aachen.
PMID- 10674715
TI - Solid phase synthesis of peptide aldehyde protease inhibitors. Probing the
proteolytic sites of hepatitis C virus polyprotein.
AB - The solid phase synthesis of a set of peptide aldehydes derived from the
NS5A/NS5B junction of hepatitis C virus (HCV) viral polyprotein is demonstrated
using an oxazolidine linker and the Multipin method. Deletion of the P6 and P5
residues results in a dramatic loss of inhibitory activity.
PMID- 10674716
TI - Chemical synthesis, characterization and activity of RK-1, a novel alpha-defensin
related peptide.
AB - The 32-residue peptide, RK-1, a novel kidney-derived three disulfide-bonded
member of the antimicrobial alpha-defensin family, was synthesized by the
continuous flow Fmoc-solid phase method. The crude, cleaved and S-reduced linear
peptide was both efficiently folded and oxidized in an acidic solution of aqueous
dimethyl sulfoxide. Following purification of the resulting product, it was shown
by a variety of analytical techniques, including matrix assisted laser desorption
time of flight mass spectrometry, to possess a very high degree of purity. The
disulfide bond pairing of the synthetic peptide was determined by 1H-NMR
spectroscopy and confirmed to be a Cys1-Cys6, Cys2-Cys4, Cys3-Cys5 arrangement
similar to other mammalian alpha-defensin peptides. The synthetic RK-1 was also
shown to inhibit the growth of Escherichia coli type strain NCTC 10418.
PMID- 10674717
TI - Synthesis, conformational analysis and bioactivity of Lan-7, a lanthionine analog
of TT-232.
AB - A sandostatin analog, TT-232 (D-Phe-c[Cys-Tyr-D-Trp-Lys-Cys]-Thr-NH2), exhibits
strong antitumor effects both in vitro and in vivo. In order to study the
structure-activity relationships of TT-232, we designed and synthesized an analog
of TT-232, namely Lan-7, in which the disulfide bridge is replaced by a
lanthionine monosulfide bridge. Conformational analysis by NMR spectroscopy and
computer simulations revealed that Lan-7 and TT-232 adopt very similar
conformations in solution, which are quite different from the preferred
conformations of sandostatin. Lan-7 has significant growth inhibition effects on
a number of human tumor cell lines. It can also induce apoptosis in human ovarian
carcinoma 2008 cells. At the same time, Lan-7 produced no toxicity to normal
human hematopoietic progenitor cells. All of these results indicate that the
modification we made does not alter the anti-tumor activity of TT-232.
PMID- 10674718
TI - Synthesis of bivalent inhibitors of eucaryotic proteasomes.
AB - Based on the peculiar spatial array of the active sites in the internal chamber
of the multicatalytic proteasome, as derived from the X-ray structure of yeast
proteasome, homo- and heterobivalent inhibitors were designed and synthesized to
exploit the principle of multivalency for enhancing inhibition potency. Peptidic
bis-aldehyde compounds of the octapeptide size were synthesized to address
adjacent active sites, whilst a PEG spacer with a statistical length distribution
of 19-25 monomers was used to link two identical or different tripeptide
aldehydes as binding heads. These bis-aldehyde compounds were synthesized
applying both methods in solution and solid phase peptide synthesis. Bivalent
binding was observed only for the PEG-spaced inhibitors suggesting that binding
from the primed side prevents hemiacetal formation with the active site threonine
residue.
PMID- 10674719
TI - Conization of the cervix using harmonic scalpel.
AB - Conization, as a surgical treatment for cervical intraepithelial neoplasm (CIN),
is a good method that preserves reproductive functions. Technological
developments have introduced a wide variety of energy sources for surgical
procedures. Traditional cold knife conization has been replaced by laser
conization and by the loop electrosurgical excisional procedure (LEEP). However,
laser conization and LEEP have some disadvantages. Laser conization requires
expensive equipment. LEEP induces electrocautery artifacts and cannot excise the
cervical tissue as a single-piece, because of the various extensions and depths
of lesion, so that evaluation of the margins is sometimes not possible. Laser
conization and LEEP both generate smoke. The presence of smoke is not only
inconvenient, but also dangerous. Harmonic Scalpel (HS), ultrasonic cutting and
coagulation system, is a new surgical tool that cuts and coagulates using
ultrasonic mechanical vibrations. Eleven women with CIN III underwent conization
using HS. HS eliminated the major disadvantages of electrosurgery and laser
surgery. No complications during conization were observed. Postoperative
hemorrhage was noted in only one patient. Histological diagnosis was not affected
by heat or ultrasound. This surgical method using HS is characterized by
negligible bleeding, a good visual field not obscured by smoke and resection of
an ideal shape that fits the size of the lesion. It is concluded that this method
overcomes most problems associated with conization using conventional methods.
PMID- 10674720
TI - Cytokine gene expression after subretinal transplantation.
AB - Transplantation study of neural retina, retinal pigment epithelial (RPE), or iris
pigment epithelial (IPE) cells have been performed not only in animal model but
in human age-related macular degeneration, and some of the findings reported with
cystoid macular edema may have been due to graft rejection. In this
investigation, we examined cytokine gene expression by reverse transcriptase
polymerase chain reaction at the transplanted subretinal space. Transplantation
was performed in normal Royal College of Surgeon's rats using cultured human RPE
and rat IPE. They were followed without immunosupression. Gene expression for
melanogenesis of transplanted human RPE was observed only in the early days after
transplantation. Rat interleukin (IL)-1alpha, -1beta1, -2, -6, interferon gamma,
and tumor necrosis factor alpha (TNF alpha) genes were also expressed after the
early days of transplantation. Cytokine expression was observed not only after
cell transplantation but also after vehicle-only injection, which was considered
a reaction to the surgical trauma. However, statistically significant amount of
expressions of IL-1alpha, -1beta, and -6 were observed after the early days of
transplantation of human RPE or IL-1alpha, -1beta, and TNF alpha of rat IPE, if
we compare them to vehicle-only injection. These cytokines may play an important
role for the local reaction after transplantation.
PMID- 10674721
TI - Interleukin-13 prevents diaphragm muscle deterioration in a septic animal model.
AB - The effects of an intravenous injection of Interleukin-13 (IL-13) after endotoxin
administration on diaphragm muscle were studied using Wistar rats. Two treatment
groups, a control (saline+endotoxin) group and an IL-13 (IL-13+endotoxin) group
were studied. E. coli endotoxin (10 mg/kg) was injected intraperitoneally 5
minutes after saline or IL-13 (0.25 microg) injection. The force-frequency
curves, twitch kinetics and fatigability were measured at 0 and 4 hours after
endotoxin injection. The force-frequency curves and twitch tension in the control
group were significantly lower at 4 hours than those at 0 hour due to endotoxin.
On the other hand, IL-13 prevented the decrement of the force-frequency curves
and twitch tension induced by endotoxin. Nicotinamide adenine dinucleotide
phosphate (NADPH) diaphorase histochemistry showed positive staining at 4 hours
due to endotoxin in the control group; however, IL-13 also blocked NADPH
diaphorase staining at 4 hours. Furthermore, the positive muscle fibers detected
by the NADPH diaphorase staining were classified as type I (slow twitch) muscle
fibers by ATPase staining. We conclude that IL-13 prevents the deterioration of
contraction induced by endotoxin by inhibiting nitric oxide production in the
diaphragm muscle, mainly the type I muscle fibers.
PMID- 10674722
TI - Therapeutic efficacy of transcranial magnetic stimulation for hereditary
spinocerebellar degeneration.
AB - We applied transcranial magnetic stimulation (TMS) as a therapeutic approach for
patients with spinocerebellar degeneration (SCD). The subjects were four familial
SCD patients (three men and one woman) aged from 27 to 76 years old. They were
genetically analysed as two spinocerebellar ataxia type 6 (SCA 6), one SCA 1, and
one SCA 7. The durations of their illness ranged from 1 to 7 years. Ten
consecutive magnetic pulses were delivered over the scalp corresponding to the
right cerebellar hemisphere, the middle of the cerebellum and the left cerebellar
hemisphere, respectively, every day for 21 days. In all patients, the time and
the number of steps required for a 10 m walk examination were significantly
decreased after TMS trial compared with those before TMS. The number of feasible
steps in tandem gait test increased. The total length of tracing body balance for
30 seconds measured by gravinometer was significantly decreased. However,
nystagmus, dysarthria or incoordination of the upper limbs did not change after
TMS trial. It is of interest that the blood flow of the cerebellar hemisphere,
putamen and pons were significantly increased during the TMS trial. Although we
do not know the exact mechanism by which TMS improved the ataxic gait, we
speculate the increase of blood flow in the cerebellum, putamen and pons takes
part in the improvement. These findings suggest that TMS over the cerebellum may
be an effective therapy for patients with SCD.
PMID- 10674723
TI - Stimulated neutrophils evoke signal transduction to increase vascular
permeability in rat lungs.
AB - The mechanisms by which stimulated neutrophils (PMNs) damage pulmonary vascular
endothelium were investigated using twenty-four perfused lung preparations
isolated from rats. We tested the ability of unstimulated and mechanically
stimulated PMNs to adhere to pulmonary endothelial cells and, thereby, alter
pulmonary vascular permeability (measured as the pulmonary filtration
coefficient) and hemodynamics. To stimulate PMNs, they were gently agitated in a
glass vial for 10 seconds. Perfusing lungs with the stimulated PMNs (stimulated
group) elicited a 3-fold increase in the filtration coefficient as compared to
lungs perfused with unstimulated cells (unstimulated group). This increase in
filtration was completely blocked by preincubation of stimulated PMNs with CD18
monoclonal antibody (MoAb group). This increase in filtration coefficient was
also completely blocked by GF109203X, a protein kinase C inhibitor (GF group).
Pulmonary vascular resistance increased when the stimulated PMNs were injected to
the isolated lungs. Although, preincubation of stimulated PMNs with CD18 MoAb
successfully blocked and GF109203X partly blocked this increase in pulmonary
vascular resistance. The accumulation of stimulated PMNs within the lungs, as
assessed by myeloperoxidase (MPO) levels, was blocked by preincubation of
stimulated PMNs with CD18 MoAb. However, GF109203X did not decrease MPO levels.
These findings suggest that stimulated PMN-induced increases in pulmonary
vascular filtration, resulted from endothelial cell injury caused by adhesion to
the endothelial cells, evoke intracellular signaling within the endothelial
cells.
PMID- 10674724
TI - Fibrous dysplasia arising from the calcaneus.
AB - A case of an 18-year-old woman with fibrous dysplasia arising in the calcaneus,
which is extremely rare, is reported, with the emphasis placed on differential
diagnosis from low-grade central osteosarcoma. She had a severe pain in her left
ankle after sprain. Plain radiographs showed a radiolucent lesion measuring 6.3 x
2.5 cm with a sclerotic margin in the left calcaneus. CT scans showed a well
defined lytic lesion with disruption of the lateral cortex and an ossification or
calcification in its center. On MR imaging, the lesion had isointensities and
high intensities on T1 and T2 weighted images, respectively, but its central
portions showed lower intensities both on T1 and T2 weighted images. The lesion
was enhanced with gadolinium except for the central portions. The specimen
obtained by open biopsy consisted of fibrous tissue and foci of irregular woven
bone. None of the nuclear atypia, mitoses, longitudinal stream of bone or
invasive nature of growth was detected. The diagnosis of fibrous dysplasia was
histologically made. The lesion was curetted and packed with autogenous bone
chips. No evidence of recurrence was noted postoperatively.
PMID- 10674725
TI - The existential ophthalmologist.
PMID- 10674726
TI - Clinical research in oculoplastic surgery for the 21st century.
PMID- 10674727
TI - The anatomy of midfacial ptosis.
AB - PURPOSE: To investigate the anatomic and histologic changes present in midfacial
ptosis. METHODS: Experimental study applying gross anatomic and histologic
techniques to formalin-preserved and fresh-frozen cadaver heads with and without
midfacial ptosis. High-resolution surface coil magnetic resonance imaging (MRI)
was performed to obtain radiologic correlations. RESULTS: The orbitomalar
ligament was further characterized by identification of a well-developed lateral
component in the sub-superficial musculoaponeurotic plane; abnormalities of this
important supporting structure were present in the subcutaneous plane in 8 of 10
specimens with midfacial ptosis. The zygomatic and masseteric cutaneous ligaments
also were further characterized on a gross anatomic level, and histologic
evidence of these two structures was produced. The subcutaneous components of the
zygomatic and masseteric cutaneous ligaments were attenuated or not identifiable
in 40% and 30% of specimens with midfacial ptosis, respectively. High-resolution
surface coil MRI provided exquisite correlations of midfacial anatomy.
CONCLUSIONS: The lateral component of the orbitomalar ligament provides major
osteocutaneous midfacial support. Subcutaneous attenuation of the orbitomalar,
masseteric cutaneous, and zygomatic ligaments was associated with midfacial
ptosis.
PMID- 10674728
TI - Injectable lyophilized particulate human fascia lata (Fascian) for lip, perioral,
and glabellar enhancement.
PMID- 10674729
TI - Small incision nonendoscopic browlift.
AB - PURPOSE: To determine the efficacy of a nonendoscopic brow/forehead lift.
METHODS: Case series of 12 patients. Small scalp and upper eyelid blepharoplasty
incisions were used to elevate the brows/forehead and perform protractor
myectomy. RESULTS: All patients achieved an aesthetically pleasing eyebrow and
forehead lift with reduction of vertical and horizontal glabellar creases.
Complications included one patient who experienced prolonged ecchymosis after
corrugator muscle resection and one patient who had asymmetric lid folds after
surgery. The length of follow-up ranged from 9 to 35 months. CONCLUSIONS: The
small incision nonendoscopic browlift technique provides a useful alternative to
the endoscopic approach.
PMID- 10674730
TI - Frontalis suspension combined with blepharoplasty as an effective treatment for
blepharospasm associated with apraxia of eyelid opening.
AB - PURPOSE: Essential blepharospasm can be associated with apraxia of eyelid opening
and is characterized by the inability to initiate the act of eyelid elevation
even after cessation of orbicularis spasms. Current therapies such as botulinum
toxin injections, orbicularis resection, or neurectomy may be unsuccessful or
have undesired side effects. METHODS: Frontalis suspension was used to treat 13
consecutive patients with apraxia and blepharospasm during a 4-year interval.
Follow-up ranged from 16 months to 55 months. To improve the aesthetic outcome,
an upper blepharoplasty was done at the same time as the frontalis suspension in
7 cases. RESULTS: Good or excellent functional results were obtained in 10 of 13
patients. In 6 of these patients, the spasm disappeared completely. Therapy was
unsuccessful in 1 patient, and in 2 patients blepharospasm recurred after 9
months. CONCLUSION: Patients with blepharospasm and apraxia of eyelid opening may
benefit from a frontalis suspension operation, which can be considered minimally
invasive and reversible.
PMID- 10674731
TI - The tarsal sandwich: a new technique in lateral canthoplasty.
AB - PURPOSE: Trauma and infection sometimes produce lower lid malpositions that are
difficult to repair cosmetically with standard canthoplasty techniques. A new
variation is described. METHODS: Surgical techniques of the tarsal strip
canthoplasty and of lateral tarsorrhaphy are combined into the tarsal sandwich.
RESULTS: Representative cases with preoperative and postoperative photos are
presented. CONCLUSION: The sandwich technique allows the surgeon more flexibility
in achieving the necessary vertical lift of the lateral canthus in difficult
cases of entropion, ectropion, and lagophthalmos.
PMID- 10674732
TI - Upper eyelid island orbicularis oculi myocutaneous flap for periorbital
reconstruction.
AB - PURPOSE: To describe the upper eyelid island orbicularis oculi myocutaneous flap,
medially or laterally based, for reconstruction of periorbital defects. METHODS:
During the past three years we have used the island orbicularis oculi
myocutaneous flap in 62 patients with tumors of the periorbital area, with the
following indications: (a) anterior lamellar defects of the medial aspect of the
upper eyelid, when the peripheral arcade is intact; (b) up to 2/3 anterior
lamellar lower eyelid defects; (c) inner and outer canthus defects; and (d)
defects of the peripalpebral area (the lateral half of the eyebrow, bridge of the
nose and suprazygomatic areas). RESULTS: The flap proved to be flexible, safe,
relatively simple, and provided good functional and aesthetic results.
Complications were minimal. CONCLUSIONS: The upper eyelid island orbicularis
oculi myocutaneous flap may be a useful tool for periorbital reconstruction.
PMID- 10674733
TI - Involutional entropion and ectropion of the Asian lower eyelid.
AB - PURPOSE: A clinical observation showed that involutional entropion of the lower
eyelid in Asians may occur more commonly than ectropion. A review of surgical
cases was performed to examine this hypothesis. METHODS: A retrospective review
of the number of Asian lower lid involutional ectropion and entropion repairs was
performed in three different clinical practice settings. These data were compared
and statistically analyzed with similar data for non-Asian patients. RESULTS: The
frequency of ectropion among Asians was significantly less than in non-Asians
(chi-square, p < 0.001). Asian entropion repair represented 11.4% of the 604
eyelid operations performed on Asians, whereas Asian ectropion repair made up
only 1.5% of cases. Non-Asian entropion and ectropion repairs were 3.7% and 6.2%,
respectively, of the 1,849 eyelid procedures performed on non-Asians.
CONCLUSIONS: Because of the normal anteriorly protruding position of the orbital
fat within the Asian lower eyelid, Asians may be more predisposed than whites to
the development of involutional entropion rather than ectropion. Removal of lower
eyelid fat should be considered in entropion repair of the Asian lower eyelid.
PMID- 10674734
TI - Lagophthalmos: an unusual manifestation of oculomotor nerve aberrant
regeneration.
AB - PURPOSE: To describe a patient with unusual findings after regeneration of the
oculomotor nerve. METHODS: Case report. RESULTS: A 35-year-old woman developed
complete right third nerve paralysis after neurosurgical ligation of internal
carotid-posterior communicating and internal carotid-ophthalmic artery aneurysms.
Permanent ipsilateral lagophthalmos appeared as third nerve function
spontaneously recovered. CONCLUSION: Lagophthalmos may rarely develop after
aberrant regeneration of the oculomotor nerve, presumably caused by co
contraction of the levator and superior rectus muscles during the Bell's
phenomenon.
PMID- 10674735
TI - Blepharoptosis and central nervous system abnormalities in combined valproate and
hydantoin embryopathy.
AB - PURPOSE: To report a case of intrauterine anticonvulsant exposure with subsequent
ocular adnexal manifestations. METHODS: Case report. RESULTS: An 18-month-old
child with known anticonvulsant embryopathy was referred for the management of
bilateral congenital blepharoptosis. Physical examination confirmed ocular and
nonocular external manifestations of valproate and hydantoin embryopathies. Cavum
septum pellucidum, mild sulcation defects, and cerebellar atrophy were identified
on neuroimaging. CONCLUSIONS: To our knowledge, our patient represents the second
reported case of anomalous septum pellucidum after intrauterine valproate
exposure. Clinicians evaluating patients with craniofacial features associated
with intrauterine valproate exposure should recognize that concomitant anomalies
of the central nervous system, including the septum pellucidum, might exist.
PMID- 10674736
TI - Monocanalicular intubation for dacryostenosis in oculo-auriculo-vertebral
dysplasia (hemifacial microsomia) with congenital corneal anesthesia.
AB - PURPOSE: To present a case of oculo-auriculo-vertebral dysplasia associated with
corneal anesthesia and ipsilateral dacryostenosis that was successfully treated
with monocanalicular lacrimal intubation. METHODS: Case report. RESULTS: Previous
neurotrophic corneal ulcers in a child with hemifacial microsomia had become
secondarily infected from a stagnant tear lake, resulting in significant corneal
scarring and visual loss. A single monocanalicular stent maintained nasolacrimal
patency without causing further corneal trauma, despite constant medial gaze
because of wide lateral tarsorrhaphy and contralateral occlusion therapy for
amblyopia. CONCLUSIONS: Monocanalicular stents may aid the treatment of
dacryostenosis in the face of compromised corneal sensation.
PMID- 10674737
TI - Probing and bicanalicular silicone tube intubation under nasal endoscopy in
congenital nasolacrimal duct obstruction.
AB - PURPOSE: To evaluate the beneficial effects of nasal endoscopy on preventing
complications during probing and bicanalicular silicone intubation, and to
determine the structural nasal abnormalities in congenital nasolacrimal duct
obstruction. METHODS: Probing and silicone tube intubation under nasal endoscopy
were performed in 37 eyes of 26 patients who ranged in age from 7 to 60 months
(mean, 18.8 +/- 13.4 months). RESULTS: By nasal endoscopy, the inferior turbinate
and meatus appeared normal in 15 patients (58%), whereas 11 patients (42%) had
hypertrophy of the inferior turbinate and/or stricture in the inferior meatus.
Twenty-four of 26 eyes (92%) were cured by probing only. We performed silicone
tube intubation and cured 11 of 12 eyes (92%) including two failures. Of 14 eyes
that had undergone failed probings elsewhere, the success rate was 92.8% (13 of
14 eyes). The overall success rate of probing and silicone tube intubation under
nasal endoscopy was 97%. CONCLUSION: Nasal endoscopy during probing and
bicanalicular silicone tube intubation is useful especially in selected cases of
failed probings. Nasal endoscopy should assist the inexperienced surgeon in
preventing trauma to the nasal base and septal mucosa, hemorrhage, and passage of
the probe under the mucosa rather than through the ostium.
PMID- 10674738
TI - Modified orbital decompression for dysthyroid orbitopathy.
AB - PURPOSE: The transantral approach to orbital decompression remains useful for the
management of exophthalmos associated with dysthyroid orbitopathy. However, the
risk of postoperative diplopia is a concern. Preservation of the anterior
periorbita may help support the orbital contents and decrease the incidence of
diplopia. METHODS: The medical records were reviewed of 15 consecutive patients
who underwent 30 transantral orbital decompressions for proptosis associated with
dysthyroid orbitopathy. The procedures were completed in standard fashion,
including removal of the inferomedial bony strut between the medial orbital wall
and the floor. However, stripping of the periorbita was only done posteriorly;
the anterior 10 to 15 mm of periorbita were left intact. RESULTS: Six patients
had preoperative diplopia that persisted after decompression. Of the nine
patients without diplopia preoperatively, none developed diplopia. Proptosis was
reduced a mean of 3.5 +/- 2.6 mm. CONCLUSIONS: Preservation of the anterior
periorbita during transantral orbital decompression reduces the risk of
postoperative diplopia. An adequate reduction in proptosis is also achieved.
PMID- 10674739
TI - Absence of seasonal variation in Graves disease.
AB - PURPOSE: To determine whether there is an identifiable pattern of seasonal
variation in the onset of symptoms of orbitopathy and thyrotoxicosis in patients
with Graves disease. METHODS: This retrospective, noncomparative case series
reviewed 305 randomly selected office records of patients referred to one author
(M.K.) for evaluation of Graves orbitopathy between July 1990 and June 1998. All
patients met inclusion criteria for the diagnosis of Graves orbitopathy. During
initial evaluation for orbitopathy, patients identified the date of onset of
orbital symptoms as well as the earliest date of either onset of thyroid symptoms
or documented thyroid abnormality. Patients were excluded from analysis of
seasonal variation if they could not recall the month of symptom onset or were
euthyroid. The onset of orbital symptoms and identification of dysthyroid state
were analyzed by calendar month and season. The chronological relationship of the
development of orbital and thyroid symptoms was evaluated. RESULTS: No
significant seasonal variation appeared in the onset of orbital symptoms or
identification of dysthyroidism. Out of 148 patients, 115 (78%) developed
symptoms of orbital disease within 18 months of the identification of
dysthyroidism. The most common presenting orbital symptoms were swelling of the
lid or prominence of the globe. CONCLUSIONS: This study fails to provide evidence
for a seasonal influence on the incidence of Graves disease and the associated
orbitopathy.
PMID- 10674740
TI - Diagnosis and management of allergic fungal sinusitis with orbital involvement.
AB - PURPOSE: Allergic fungal sinusitis (AFS) is a noninvasive disease characterized
by recurrent sinusitis. This condition is commonly treated with surgical
debridement and several months of systemic corticosteroids. The treatment of AFS
is examined in this study. METHODS: A retrospective case series of three patients
with AFS. RESULTS: All three patients were treated with surgical debridement and
less than one month of systemic corticosteroids. The patients then were treated
with intranasal corticosteroids and monitored closely. Antifungal therapy was not
used. All three patients remained disease-free during follow-up ranging from 12
months to 36 months. CONCLUSIONS: Surgical debridement and systemic
corticosteroids for less than four weeks followed by intranasal corticosteroids
may provide long-term control of AFS. Additional study is recommended to examine
further the optimal treatment for AFS.
PMID- 10674741
TI - Osteogenic sarcoma and phthisis bulbi: a case report.
AB - PURPOSE: To describe a case of osteogenic sarcoma (osteosarcoma) that developed
within a phthisical eye. METHOD: Case report. RESULTS: An 86-year-old woman with
a 20-year history of phthisis bulbi developed pain and proptosis. Tumor was
identified by computed tomography. An exenteration was performed, and osteogenic
sarcoma was identified. CONCLUSION: Osteogenic sarcoma is the most common primary
malignant tumor of bone. In the orbit it frequently is associated with prior
irradiation for retinoblastoma. We describe the first case of osteogenic sarcoma
that developed de novo from bone within a phthisical eye.
PMID- 10674742
TI - Sling removal.
PMID- 10674743
TI - Research toward safer resection of the cirrhotic liver.
AB - Despite recent advances in hepatic surgery, resection of the cirrhotic liver
continues to be fraught with high morbidity and mortality rates. As a result, for
many patients requiring resection of HCC the postoperative course is complicated
and the probability of cure is diminished by coexisting cirrhosis. In this
review, we discuss the characteristics of the cirrhotic liver which make it
poorly tolerant of resection and the most common complications that follow such
surgery. The main purpose of this paper is to review recent attempts to identify
interventions that might be beneficial to cirrhotic patients undergoing
resection. These interventions include assessment of liver reserve, advances in
surgical technique, and improvement in liver function and regeneration.
PMID- 10674744
TI - Cholangiographic features in the diagnosis and management of obstructive icteric
type hepatocellular carcinoma.
AB - In 11 years and 3 months, 2,037 patients with HCC were seen and 48 patients
(2.4%) were diagnosed to have obstructive icteric type HCC. Five patients were
terminally ill and were not investigated further. Forty three patients were
initially investigated by endoscopic retrograde cholangiography (ERC) or
percutaneous transhepatic cholangiogram (PTC) and classified as having
obstructive icteric type 1, 2, or 3 HCC based on the cholangiographic findings.
The obstruction in type 1 HCC was due to intraluminal tumour casts and/or tumour
fragments obstructing the hepatic ductal confluence or common bile duct, while
intraluminal blood clots, from haemobilia, filling the biliary tree was the cause
in type 2 HCC. The pathology in type 3 HCC was extraluminal obstruction by
extensive tumour encasement of the intra-hepatic biliary ductal system and/or
extrinsic compression of the hepatic and common bile ducts by tumour(s) and/or
malignant lymph nodes. At the initial ERC/PTC, 10 patients (5 resected, 50%) had
obstructive icteric type 1 and 23 patients (0 resected) had obstructive icteric
type 3 HCC. Of the 10 patients initially classified according to cholangiography
to have obstructive icteric type 2 HCC, subsequent investigations revealed that 6
patients had type 1 HCC (4 resectable,67%) and 4 patients had type 3 HCC (0
resectable). The classification of the obstructive icteric type HCC into types 1,
2, and 3, based on the initial cholangiographic appearances has simplified and
rationalized our management strategy for this condition.
PMID- 10674745
TI - Surgery for deeply located hydatid cysts of the liver: a simple alternative.
AB - Gaining access to deeply located hydatid cysts of the liver using conventional
surgical techniques may be accompanied by significant intra- and postoperative
complications. In addition, obliteration of the cyst cavity is still a matter of
controversy. We developed a novel method for easy access to deep hydatid cysts
using a water jet dissector (Parenchimotom 01, TOSA, Pleven, Bulgaria). At
pressure of 20 Bar using a 0.2 mm nozzle, a corridor is created through the liver
parenchyma overlying the cyst; vessels and biliary duct are thus clearly
displayed as linear structures traversing the corridor and are ligated and
divided under direct visual control. The fibrous capsule of the cyst is spared by
the jet. Following endocystectomy performed in the ordinary manner, the cyst
cavity is filled with gelatin sponge; a passive tube drain is placed in contact
with the liver incision. In allowing for a selective dissection of the liver
parenchyma, the jet makes safe access to deeply located hydatid cysts possible.
On the other hand, the gelatin sponge induces good fibroblast response and
assists in rapid and effective obliteration of the residual cavity. This novel
technique works well in our hands but more extensive studies are necessary before
its final acceptance.
PMID- 10674746
TI - The impairment of wound healing process is correlated with abnormalities of TNF
alpha production by peritoneal exudate cells in obstructive jaundiced rats.
AB - The wound healing process and production of tumour necrosis factor alpha (TNF
alpha) by peritoneal cells of 7-day and 14-day obstructive jaundice (OJ) and sham
operated rats were investigated. In the study the skin wound breaking strength
was measured. In addition such histological and biochemical parameters as
fibroblast and endothelial cell proliferation, inflammatory cell infiltration and
hydroxyproline content were evaluated in polyurethane sponge discs implanted
subcutaneously into rats. TNF-alpha production by peritoneal exudate cells (PEC),
both spontaneous and lipopolysaccharide (LPS)-induced was determined by a
bioassay. In OJ rats the process of both early as well as late phase of healing
was impaired. The breaking strength of skin wound was decreased, the fibroblast
and endothelial cell proliferation and collagen deposition, as well as
hydroxyproline content were diminished. In 7 day OJ the numbers of inflammatory
cells in the implants were lowered with a subsequent slight increase on day 14 of
OJ. The spontaneous and LPS induced TNF-alpha production by PEC were
significantly higher in 7 day OJ as compared with sham-operated controls. On day
14 of OJ the LPS-induced TNF-alpha level was, in contrast, much lower and did not
differ much from the spontaneous TNF-alpha production. We conclude that the
impairment of wound healing in OJ results from disturbances in functioning of the
immune system caused by systemic endotoxaemia.
PMID- 10674747
TI - Interval laparoscopic cholecystectomy in the management of acute biliary
pancreatitis.
AB - The timing of laparoscopic cholecystectomy following an attack of acute biliary
pancreatitis is controversial. The traditional approach of interval
cholecystectomy has been challenged recently. The present study was designed to
evaluate the benefits of interval laparoscopic cholecystectomy for patients with
mild acute pancreatitis (Ranson less than 3). Nineteen patients with mild
pancreatitis underwent ultrasonographic evaluation to confirm the biliary
etiology. ERCP was performed in all patients on the first available endoscopy
list, and endoscopic sphincterotomy was performed in two patients with calculi or
dilated common bile duct on ultrasonographic examination. Medical treatment was
administered and laparoscopic cholecystectomy was scheduled after 8-12 weeks to
allow the inflammatory process to settle. There were no recurrent attacks of
pancreatitis during this period. The degree of difficulty of the laparoscopic
procedure was assessed by the presence of adhesions to the gallbladder area,
difficulty of dissection in the Calot's triangle, intraoperative bleeding and the
need for a drain. Six patients (31.5%) had severe adhesions, difficult dissection
of the cystic duct and artery, bleeding and prolonged operating time. In two of
these patients (10.5%) the procedure was converted to open cholecystectomy. In
conclusion, our results suggest that postponing laparoscopic cholecystectomy in
acute pancreatitis patients is not advantageous surgically and does not justify
the risk of further morbidity caused by the gallbladder disease.
PMID- 10674748
TI - Treatment options for villous adenoma of the ampulla of Vater.
AB - INTRODUCTION: Duodenal villous adenoma arising from the ampulla of Vater has a
high risk of malignant development. Excluding associated malignant disease prior
to resection of an adenoma of the ampulla is not always possible. Therefore, the
surgical procedure of choice to treat this rare tumour is still controversial.
OBJECTIVE: To evaluate retrospectively results of treatment of villous adenoma
arising from ampulla of Vater with dysplasia or associated carcinoma limited to
the ampulla. PATIENTS AND METHODS: From 1985 to 1996, eight patients have been
diagnosed with ampullary villous adenoma suitable for resection. We have reviewed
treatment, morbidity, mortality, follow-up and final outcome. RESULTS:
Pancreatoduodenectomy (PD) was performed in 4 patients. Transduodenal
ampullectomy and endoscopic resection was performed in 2 patients each. There was
no perioperative mortality. None of the patients had biliary, pancreatic or
intestinal leakage but two patients who underwent PD had minor postoperative
complications. The mean follow-up was 44 (range: 6-132) months. Villous adenoma
was associated with adenocarcinoma in 50% of the cases (4/8 patients). During the
follow-up both patients who underwent transduodenal ampullectomy developed
recurrent disease. All patients initially treated by PD are alive without
evidence of recurrent disease. CONCLUSIONS: Treatment of villous adenoma of the
ampulla must be individualized within certain limits. In our series, PD achieve
good results and it appears to be the procedure of choice in order to treat
villous adenomas with proved presence of carcinoma, carcinoma in situ or severe
dysplasia. Endoscopic or local resection may be appropriate for small benign
tumours in high risk patients.
PMID- 10674749
TI - Pancreatic pseudocysts transpapillary and transmural drainage.
AB - BACKGROUND: Pancreatic pseudocyst endoscopic drainage has been described as a
good treatment option, with morbidity and mortality rates that are lower than
surgery. The aim of our study is to describe the efficacy of different forms of
endoscopic drainage and estimate pseudocyst recurrence rate after short follow up
period. PATIENTS AND METHODS: We studied 30 patients with pancreatic pseudocyst
that presented some indication for treatment: persistent abdominal pain,
infection or cholestasis. Clinical evaluation was performed with a pain scale, 0
meaning absence of pain and 4 meaning continuous pain. Pseudocysts were first
evaluated by abdominal CT scan, and after endoscopic retrograde pancreatography
the patients were treated by transpapillary or transmural (cystduodenostomy or
cystgastrostomy) drainage. Pseudocyst resolution was documented by serial CT
scans. RESULTS: 25/30 patients could be treated. Drainage was successful in 21
(70% in an 'intention to treat' basis). After a mean follow-up of 42 +/- 35.82
weeks, there was only 1 (4.2%) recurrence. A total of 6 complications occurred in
37 procedures (16.2%), and all but 2 were managed clinically and/or
endoscopically: there was no mortality related to the procedure. Patients
submitted to combined drainage needed more procedures than the other groups.
There was no difference in the efficacy when we compared the three different
drainage methods. CONCLUSIONS: We concluded that pancreatic pseudocyst endoscopic
drainage is possible in most patients, with high success rate and low morbidity.
PMID- 10674750
TI - Adenoma of the papillae of Vater. Report of eleven cases.
AB - Eleven patients with a preoperative diagnosis of adenoma of the papillae of Vater
were followed up during the fifteen-year period from 1984 till 1998 in the Oulu
University Hospital. Seven patients were treated primarily by transduodenal
excision without any recurrences so far. One of these seven patients was found to
have adenocarcinoma in a histological examination. Active surgery for adenoma of
the papillae of Vater is recommended because of the precancerous nature of the
lesion, and because malignancy cannot always be detected by endoscopic biopsies.
Transduodenal excision could be recommend for patients at high operative risk,
especially in cases with small adenomas and low-grade dysplasia, where
histologically free resection margins can be achieved, but
pancreaticoduodenectomy should still be performed on patients at low operative
risk.
PMID- 10674751
TI - Mucobilia in association with a biliary cystadenocarcinoma of the caudate duct: a
rare cause of malignant biliary obstruction.
AB - Mucobilia is a rare condition characterized by the accumulation of abundant mucus
within the intra- or extrahepatic biliary tree. A variety of hepatobiliary and
pancreatic neoplasms are mucin producing and have been associated with the
development of mucobilia including biliary mucinosis, biliary papillomatosis,
mucin-producing cholangiocarcinoma (MPCC), or cystic neoplasms of the pancreas or
biliary tree (cystadenoma or cystadenocarcinoma). We report the case of 46 year
old male with a biliary cystadenocarcinoma of the caudate lobe which resulted in
chronic biliary obstruction and relapsing cholangitis. A review of the literature
for both mucobilia and biliary cystadenocarcinoma is provided along with a
discussion addressing the clinical presentation, diagnosis, treatment, and
prognosis for this rare entity.
PMID- 10674752
TI - Peliosis hepatis with intrahepatic hemorrhage: successful embolization of the
hepatic artery.
AB - Peliosis hepatis is defined as the appearance of blood filled lakes in the
hepatic parenchyma. It has been associated with various pharmacological agents
and infections. Treatment has been primarily symptomatic and includes
discontinuation of offending medications, partial hepatectomy or occasionally
liver transplantation. We report a 58 year old white female on hormone
replacement therapy who developed symptomatic peliosis hepatis and underwent
successful superselective hepatic artery embolization with control of bleeding.
PMID- 10674753
TI - Major HPB procedures must be undertaken in high volume quaternary centres?
AB - BACKGROUND: Reports of better results at national referral centers than at low
volume community hospitals have prompted calls for regionalizing
pancreaticoduodenectomy (the Whipple procedure). We examined the relationship
between hospital volume and mortality with this procedure across all US
hospitals. METHODS: Using information from the Medicare claims database, we
performed a national cohort study of 7,229 Medicare patients more than 65 years
old undergoing pancreaticoduodenectomy between 1992 and 1995. We divided the
study population into approximate quartiles according to the hospital's average
annual volume of pancreaticoduodenectomies in Medicare patients: very low (<1/y),
low (1-2/y), medium (2-5/y), and high (5+/y). Using multivariate logistic
regression to account for potentially confounding patient characteristics, we
examined the association between institutional volume and in-hospital mortality,
our primary outcome measure. RESULTS: More than 50% of Medicare patients
undergoing pancreaticoduodenectomy received care at hospitals performing fewer
than 2 such procedures per year. In-hospital mortality rates at these low- and
very-low-volume hospitals were 3- to 4-fold higher than at high-volume hospitals
(12% and 16%, respectively, vs. 4%, P<.001). Within the high-volume quartile, the
10 hospitals with the nation's highest volumes had lower mortality rates than the
remaining high-volume centers (2.1% vs. 6.2%, P<.01). The strong association
between institutional volume and mortality could not be attributed to patient
case-mix differences or referral bias. CONCLUSIONS: Although volume-outcome
relationships have been reported for many complex surgical procedures, hospital
experience is particularly important with pancreaticoduodenectomy. Patients
considering this procedure should be given the option of care at a high-volume
referral center.
PMID- 10674754
TI - Validation of the weight-drop contusion model in rats: a comparative study of
human spinal cord injury.
AB - Animal models are widely used for studying the pathophysiology as well as
treatment strategies for injuries of the central nervous system. However, it is
still unclear in how far the rat model of spinal cord injury (SCI) is valid for
human SCI. Therefore, comparisons were made among functional,
electrophysiological, and morphological outcome parameters following SCI in rats
and humans. Contusion of the mid-thoracic spinal cord in 27 adult rats was
induced by a weight-drop, leading to severe deficits in open field locomotion at
a chronic stage. The data of 85 human patients with chronic SCI were collected
and compared with the rat data. In electrophysiological recordings, prolonged
latencies and reduced amplitudes in both motor evoked potentials (MEP) and
somatosensory evoked potentials (SSEP) were closely correlated to the impairment
of locomotor capacity of lower limbs in rats and humans. The morphological
parameters assessed by high-resolution magnetic resonance imaging (MRI) in both
species indicated that the lesion length and spinal cord atrophy were
significantly related to the electrophysiological and functional outcome
parameters. In rats, histological analysis was performed and showed, in addition
to the MRI, a close relationship between spared white matter and locomotor
capacity. Our results suggest an analogous relationship in rats and humans with
respect to functional, electrophysiological, and morphological outcomes. Thus,
the techniques for evaluating the extent and severity of SCI in humans and rats
are of comparable value. This indicates that the rat can serve as an adequate
animal model for research on functional and morphological changes after SCI and
the effects of new treatment strategies.
PMID- 10674755
TI - Neuroprotective effects of gacyclidine after experimental photochemical spinal
cord lesion in adult rats: dose-window and time-window effects.
AB - The aim of this study was to evaluate the efficacy, optimal dose, and optimal
time-window of gacyclidine, a novel N-methyl-D-aspartate (NMDA) receptor
antagonist, in terms of its functional, histopathological, and
electrophysiological effects after experimental spinal cord injury. The spinal
cord of rats was damaged by a photochemical method and the animals were treated
by saline or gacyclidine at doses of 1, 2.5, or 5 mg/kg 10 min after injury or
gacyclidine 1 mg/kg 10, 30, 60, and 120 min after injury. The time-course of the
motor score (walking and inclined-plane stability) was evaluated until day 18,
and somatosensory evoked potentials were determined on day 18. The animals were
then sacrificed, and the cross-sectional area of the spinal cord (at the
epicenter of the injury, above and below the injury) was measured. Walking
recovery was better in most of the groups treated after injury than in the
untreated injured animals. Motor performances were related to preservation of a
larger undamaged area of spinal cord at the level of the injury and,
interestingly, with prevention of extension of the anatomical lesion above the
level of the injury. Somatosensory evoked potential amplitudes were often higher
in treated groups. These results confirm that gacyclidine induces dose-dependent
and time-dependent attenuation of spinal cord damage after an experimental
vascular lesion. Although all three doses induced neuroprotective effects,
recovery was greater and very homogeneous in the group treated with 1 mg/kg.
Moreover, recovery was slightly better and more homogeneous within the groups
treated 10 and 30 min after injury compared to the other groups. It appears that,
according to the existing evidence, NMDA antagonists are an essential component
in the elaboration of a neuroprotective strategy after spinal cord trauma.
PMID- 10674756
TI - Extracellular N-acetyl-aspartate as a biochemical marker of the severity of
neuronal damage following experimental acute traumatic brain injury.
AB - We evaluated the acute changes in interstitial and whole brain N-acetyl-aspartate
(NAA) measured by high-performance liquid chromatography in animal models of
isolated traumatic brain injury (TBI) and TBI combined with secondary insult
(hypotension-hypoxia [HH]). The Marmarou impact-acceleration model was used. Four
groups were studied: (1) sham-operated control, (2) TBI alone (TBI 500 gm, 2 m),
(3) TBI plus 30 min of hypoxia (PaO2, approximately 40 mm Hg) and hypotension
(mean arterial blood pressure, approximately 40 mm Hg) (THH), and (4) HH alone.
The baseline value for dialysate NAA (NAAd) in the rats was 8.17+/-1 microM. No
significant difference between groups was found for this baseline value. The TBI
group had a modest (100%) transient increase in NAAd after isolated TBI. The HH
group had a transient (500%) increase in NAAd at 1 h, sustained for 2 h. In the
THH group, there was a persistent increase in NAAd (800%) that peaked at 2.5 h.
The whole brain NAA (NAAw) concentration in controls was 8.5+/-0.5 mmol/kg wet
weight. There was no significant difference between TBI and controls; however,
there was a significant decrease in NAAw in the THH and HH group compared to
controls. Thus, in this animal model of TBI and TBI with secondary insult, we
found that persistent, marked elevation in NAA is associated with TBI and
secondary ischemic/hypoxic insult, but not with isolated TBI alone.
PMID- 10674757
TI - Cerebral hemodynamic effects of 7.2% hypertonic saline in patients with head
injury and raised intracranial pressure.
AB - The aim of the present study was to investigate the acute effects of 7.2%
hypertonic saline (HS) on intracranial pressure (ICP), cerebral and systemic
hemodynamics, serum sodium, and osmolality in 14 patients with moderate and
severe traumatic brain injury (Glasgow Coma Scale < or =13) and raised ICP (>15
mm Hg) within the first 72 h postinjury. After CO2 reactivity and autoregulation
were tested, each patient received a 15-min infusion of 7.2% HS (1,232 mEq/L,
volume 1.5 mL/kg). ICP, serial hemodynamics, cerebral blood flow (CBF) estimated
from cerebral arteriovenous oxygen content difference (AVDO2), and laboratory
variables, including serum osmolality, electrolytes, urea, and creatinine were
collected before infusion (T0) and at 5, 30, 60, and 120 min after (T5, T30, T60,
T120). Urine output was measured 2 h before infusion and at T120. While CO2
reactivity was preserved in all patients, autoregulation was preserved in only
four. ICP decreased to about 30% of base line (p = 0.0001) during the whole study
period. During the first hour after infusion, cerebral perfusion pressure (p< or
=0.04) and cardiac index (CI; p< or =0.01) increased, while systemic vascular
resistance index fell (p< or =0.05). Heart rate increased (p< or =0.04) during
the first 30 min. Pulmonary artery occlusion pressure (PAOP) increased (p =
0.004) at T5. There were no significant changes in mean arterial blood pressure
(MABP), urine output, and estimated CBF. A significant positive correlation (r =
0.75; p = 0.02) between ICP and serum osmolality was found at T5. The
administration of 7.2% HS in patients with traumatic brain injury significantly
reduces ICP without significant changes in relative global CBF (expressed as
1/AVDO2), increases CI and transiently increases PAOP, without changing MABP and
urine output. The correlation between changes in osmolality and ICP supports the
hypothesis that HSS may in part decrease ICP by means of an osmotic mechanism.
PMID- 10674758
TI - Characterization of plasma magnesium concentration and oxidative stress following
graded traumatic brain injury in humans.
AB - Plasma magnesium, calcium, and oxidative status were investigated in 31 male
casualties with traumatic brain injury (TBI) during a 7-day posttraumatic period.
The study group consisted of eight patients with mild closed head injury (Glasgow
Coma Scale score [GCS] of 13-15), 10 patients with extensive penetrating head
injury (GCS 4-6), and 13 patients with blast injuries but without direct head
trauma. The latter group was included since previous experimental and clinical
data have confirmed the development of indirect brain trauma in patients with
blast injuries. Patients with multiple injuries were not included. Significant
declines in plasma divalent cations were found in GCS 4-6 patients immediately
after TBI and persisting for the entire 7-day study period. Similar changes in
magnesium, but not calcium, were present in the GCS 13-15 and the blast injury
groups, but only up until day 3 after injury. Alterations in lipid peroxidation
products and superoxide anions were also observed following TBI. Increased lipid
peroxidation was noted in all three groups over the entire posttraumatic period
while increases in superoxide anion generation occurred transiently immediately
following TBI. Thereafter, in the GCS 13-15 and blast injury groups, superoxide
anions subsequently normalized, whereas in extensive head injury (GCS 4-6),
superoxide anion generation significantly declined. A negative correlation
between magnesium balance and oxidative stress was observed in all patients
immediately after injury persisting in GCS 4-6 patients to the end of the
observation period. Our findings suggest an interrelationship between magnesium
changes and blood oxidants/antioxidants after TBI, which could be of both
diagnostic and prognostic value in patients with neurotrauma.
PMID- 10674759
TI - Regional expression and role of cyclooxygenase-2 following experimental traumatic
brain injury.
AB - Prostaglandins, potent mediators of inflammation, are generated from arachidonic
acid (AA) via the action of cyclooxygenase-1 and -2 (COX-1 and COX-2). In this
study, we report that lateral cortical impact injury in rats significantly
increases COX-2 protein levels both in the cortex surrounding the injury site and
the ipsilateral hippocampus. COX-2 protein level was elevated as early as 3 h
postinjury and persisted for up to 3 days. Increases in immunoreactivity were
detected not only in the adjacent cortex and hippocampus, but were also observed
in the contralateral cortex and hippocampus, the ipsilateral piriform cortex and
the ipsilateral amygdaloid complex. COX-2 immunoreactive cells appear
morphologically normal and do not present any of the characteristic features of
apoptosis. Double immunostaining experiments using either a neuron-specific or an
astroglial-specific marker show that the expression of COX-2 is localized almost
exclusively in neuronal cells. Administration of the COX-2 inhibitor 4-[5-(4
methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfona mide (celecoxib,
marketed as Celebrex) worsens motor, but not cognitive, performance, suggesting
that COX-2 induction following traumatic brain injury may play a protective role.
PMID- 10674761
TI - Application of 2,3,5-triphenyltetrazolium chloride staining to evaluate injury
volume after controlled cortical impact brain injury: role of brain edema in
evolution of injury volume.
AB - A reliable method for measuring injury volume after traumatic brain injury (TBI)
is of great importance when studying pharmacological protective agents in the
field of head trauma research. Utilization of 2,3,5-triphenyltetrazolium chloride
(TTC) has gained extensive acceptance in stroke research and has recently been
applied to injury volume measurement in the lateral fluid percussion model. The
present study was undertaken to apply this method to the controlled cortical
impact (CCI) model and to study the role of brain edema. Male Sprague-Dawley rats
were subjected to CCI brain injury at a velocity of 3 m/sec and 1 mm (mild), 2 mm
(moderate), and 3 mm (severe injury) deformation, while rats in the control group
were subjected to the same surgical procedure but received no injury. Absolute
and corrected injury volumes with TTC staining and brain edema measurements with
the wet-dry method were evaluated at 1, 2, 3, 4, and 7 days after TBI. The most
prominent injury volume in the moderate injury group (2 mm deformation) was seen
at postinjury day 1 and 2 (day 1, absolute: 49.1+/-5.6, corrected: 40.5+/-7.9;
day 2, absolute: 46+/-6.9, corrected: 40.2+/-10.5), whereas the smallest injury
volume was found at postinjury day 7 (absolute: 24.9+/-7, corrected: 27.4+/-7.4).
The time course of brain edema studies demonstrates that brain edema formation
peaks at postinjury day 1. A statistically significant reduction of injury volume
was observed after postinjury day 4. We also observed that due to the presence of
brain edema absolute injury volume is more than corrected injury volume in the
first 3 days after injury as opposed to injury volume at postinjury day 7. These
results suggest that the measurement of injury volume with TTC staining should be
corrected for brain edema in the CCI brain injury model.
PMID- 10674760
TI - The novel compound LOE 908 attenuates acute neuromotor dysfunction but not
cognitive impairment or cortical tissue loss following traumatic brain injury in
rats.
AB - Experimental traumatic brain injury (TBI) initiates massive disturbances in Ca2+
concentrations in the brain that may contribute to neuronal damage. Intracellular
Ca2+ may be elevated via influx through voltage-operated cation channels, ligand
gated ionotropic channels, and store-operated cation channels (SOCs). In the
present study, we evaluated the neurobehavioral and histological effects of acute
posttraumatic administration of (R,S)-(3,4-dihydro-6,7-dimethoxy-isoquinoline-1
yl)-2-phenyl-N,N-di[2-(2 ,3,4-trimethoxyphenyl)ethyl]-acetamide (LOE 908), a
broad spectrum inhibitor of voltage-operated cation channels and SOCs. Male
Sprague-Dawley rats (n = 53) were trained in the Morris water maze, anesthetized
(60 mg/kg pentobarbital, i.p.), and subjected to lateral fluid percussion brain
injury (2.5-2.7 atm; n = 38) or surgery without injury (n = 15). At 15 min
postinjury, animals were randomized to receive intravenous administration of
either a high dose of LOE 908 (4 mg/kg bolus followed by 160 mg/kg over 24 h; n =
13), a low dose of LOE 908 (2 mg/kg bolus followed by 80 mg/kg over 24 h; n =
12), or vehicle (n = 13). Uninjured controls received the high dose of LOE 908 (n
= 8) or vehicle (n = 7). Treatment with either dose of LOE 908 significantly
improved neuromotor function at 48 h postinjury when compared to vehicle
treatment. Although a significant deficit in visuospatial memory was observed in
brain-injured animals at this timepoint when compared to uninjured animals,
neither dose of LOE 908 attenuated injury-induced cognitive dysfunction.
Histological evaluation revealed that neither dose of LOE 908 affected cortical
lesion size at 48 h postinjury. These data suggest that broad spectrum cation
channel blockers may be beneficial in the treatment of neurological motor
dysfunction when administered in the acute posttraumatic period.
PMID- 10674762
TI - Fluid percussion injury transiently increases then decreases brain oxygen
consumption in the rat.
AB - The oxygen consumption (VO2 microL/h/mg) of sham and of traumatized rat brains
within 30 min and 6 h after a lateral fluid percussion injury (FPI) was measured
with the Cartesian microrespirometer. Brain slices were cut at the plain of
injury and site-specific 20-60-microg cores of tissue were transferred to the
microrespirometer. In sham brains, the cortical VO2 (CVO2) was 13.78+/-0.64 and
the hippocampal VO2 (HPVO2) was 11.20+/-0.58 microL/h/mg (p<0.05). Within 30 min
of the injury, the respective values of 16.89+/-0.55 and 14.91+/-0.06 were
significantly increased (p<0.05). The combined VO2 (CVO2, HPVO2) of 12.49+/-0.06
microL/h/mg in shams was significantly less than the combined VO2 of 15.90+/-0.59
microL/h/mg at 30 min post FPI (p<0.001). The maximal CVO2 of 19.49+/-1.10
microL/h/mg and the maximal HPVO2 of 15.98+/-0.99 microL/h/mg were both obtained
from the ipsilateral side of the injury. Whereas the contralateral cortical value
for injured brains was not significantly different from that of the shams, both
ipsilateral and contralateral hippocampal values were significantly greater than
that of the shams in response to injury (p<0.05). By 6 h postinjury, the combined
VO2 had dropped to 10.01+/-0.84 microL/h/mg but was not significantly lower than
the sham values. The data indicate that normal CVO2 is greater than normal HPVO2.
The FPI produces significant increases in both CVO2 and HPVO2. Also, while the
immediate increase in CVO2 appears to be injury-site dependent, that is,
regional, the increase in HPVO2 appears to be global.
PMID- 10674763
TI - FDA handling of ADR reports needs improvement.
PMID- 10674764
TI - Non-patient-care activities dilute pharmacists' time, NACDS study shows. National
Association of Chain Drug Stores.
PMID- 10674765
TI - Pharmaceuticals hit the internet auction block.
PMID- 10674766
TI - Oral and i.v. formulations of gatifloxacin cleared for U.S. market.
PMID- 10674768
TI - Status report on VA national formulary issued.
PMID- 10674767
TI - Topical treatment approved for fungal nail infection.
PMID- 10674769
TI - Precautions urged in disposing of prescription containers.
PMID- 10674770
TI - Researchers find differences in effectiveness of ADHD treatment strategies.
PMID- 10674771
TI - BPS roster of certified pharmacists nears 3000 mark.
PMID- 10674772
TI - Study provides additional support for hypericum extract.
PMID- 10674773
TI - Inadvertent intrauterine infusion of ampicillin-sulbactam.
PMID- 10674774
TI - Identifying noncompliance by combining refill audits with telephone follow-up.
PMID- 10674775
TI - Aspirin and dipyridamole for stroke prevention.
PMID- 10674776
TI - New drugs for the treatment of rheumatoid arthritis.
AB - New pharmacologic treatment options for rheumatoid arthritis (RA) are described.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for RA but
are limited by the risk of adverse effects, especially gastrointestinal and renal
toxicity. The therapeutic effects of these agents are mediated primarily through
inhibition of cyclooxygenase (COX) and prevention of subsequent formation of
prostaglandins and related inflammatory mediators. Nonspecific COX inhibition
appears to be responsible for much of the toxicity of NSAIDs. Agents have been
developed that can selectively inhibit the COX-2 isoform, while sparing COX-1.
Celecoxib and other COX-2 inhibitors appear to be no more efficacious than
conventional NSAIDs, but offer superior safety. COX-2 inhibitors should be
considered for patients who are candidates for NSAID therapy but at risk for GI
bleeding. Unlike disease-modifying antirheumatic drugs (DMARDs), these agents do
not alter underlying disease progression. Leflunomide is a newer DMARD that
reduces pyrimidine synthesis, thus decreasing rheumatoid inflammation.
Leflunomide appears to be as effective as methotrexate but, unlike that drug,
does not necessitate monitoring for bone marrow toxicity. Etanercept, the first
biological agent with FDA-approved labeling for use in RA, has shown efficacy and
minimal toxicity, except for injection-site reactions. Other biologicals that
have been investigated for use in RA include infliximab and interleukin-1
receptor antagonist. COX-2 inhibitors, leflunomide, and etanercept are promising
new drugs available for treating RA. Other agents are under development.
PMID- 10674777
TI - Atypical antipsychotic agents: a critical review.
AB - The pharmacology, efficacy, and adverse effects of atypical antipsychotic agents
when used to treat schizophrenia and other disorders are reviewed. Atypical
antipsychotic agents were developed in response to problems with typical agents,
including lack of efficacy in some patients, lack of improvement in negative
symptoms, and troublesome adverse effects, especially extrapyramidal symptoms
(EPSs) and tardive dyskinesia CTD). Atypical antipsychotics differ from typical
psychotics in their "limbic-specific" dopamine type 2 (D2)-receptor binding and
high ratio of serotonin type 2 (5-HT2)-receptor binding to D2 binding. In
clinical trials in patients with non-treatment-resistant schizophrenia,
risperidone and olanzapine were superior to placebo for positive and negative
symptoms. Risperidone and olanzapine were superior to haloperidol on some
measures. Quetiapine was better than placebo but was not better than typical
antipsychotics. Head-to-head comparisons of atypical antipsychotics in non
treatment-resistant schizophrenia have been inconclusive. Clozapine remains the
standard agent for treatment-resistant schizophrenia. Atypical agents are
substantially more expensive than their typical antipsychotic counterparts. To
fully determine the overall efficiency of these drugs, other potential benefits,
such as improved quality of life, need to be factored in. Atypical antipsychotics
are associated with a decreased capacity to cause EPSs, TD, neuroleptic malignant
syndrome, and hyperprolactinemia. Clozapine carries a risk of agranulocytosis;
the white blood cell count must be monitored. Atypical antipsychotics are
increasingly being used for indications other than schizophrenia, such as the
management of aggression, mania, and depression. Atypical antipsychotics are
often considered first-line agents for treating schizophrenia and are promising
treatment alternatives for other psychiatric and neurologic conditions.
PMID- 10674778
TI - Respiratory syncytial virus (RSV) immune globulin and palivizumab for prevention
of RSV infection.
AB - The efficacy, safety, administration, and advantages and disadvantages of
respiratory syncytial virus (RSV) immune globulin and palivizumab for preventing
RSV infection are discussed. Prevention of RSV infection has attracted
considerable attention because of its dinical and economic impact. Studies have
shown respiratory syncytial virus immune globulin intravenous (RSV-IGIV) and
palivizumab to be effective in decreasing the number of hospitalizations and
hospital days attributable to RSV. The number of intensive-care-unit admissions
and the severity of RSV infection in high-risk children decreased with the use of
these agents. Both agents have been well tolerated, with few adverse effects;
however, their high cost necessitates strict guidelines on use. The patient
populations at greatest risk are those with bronchopulmonary dysplasia, those
with congenital heart disease, those with a history of apnea or respiratory
arrest, immunocompromised patients, those with pulmonary consolidation on chest
radiography, and those born prematurely. American Academy of Pediatrics
guidelines do not preferentially recommend use of either agent; each has
advantages and disadvantages. Prophylactic therapy with RSV-IGIV or palivizumab
may reduce the likelihood of RSV infection in high-risk patients.
PMID- 10674780
TI - Preparing for a joint commission survey: a pharmacist's perspective.
PMID- 10674779
TI - Outcomes of an antimicrobial control program in a teaching hospital.
AB - The clinical outcomes and cost-effectiveness of an antimicrobial control program
(ACP) were studied. The impact of an ACP in a teaching hospital was analyzed by
comparing clinical outcomes and intravenous antimicrobial costs over two two-year
periods, the two years before the program and the first two years after the
program's inception. Admission baseline data, length of stay, mortality, and
readmission rates were gathered for each patient. Patients were identified by
using the International Classification of Diseases. Multivariate logistic
regression models were constructed for mortality and for lengths of stay of 12 or
more days. The acquisition costs of intravenous antimicrobial agents for the
second baseline year and the entire program period were tabulated and compared.
The average daily inpatient census was determined. The ACP was associated with a
2.4-day decrease in length of stay and a reduction in mortality from 8.28% to
6.61%. Rates of readmission for infection within 30 days of discharge remained
about the same. Inpatient pharmacy costs other than intravenous antimicrobials
decreased an average of only 5.7% over the two program years, but the acquisition
cost of intravenous antimicrobials for both program years yielded a total cost
saving of $291,885, a reduction of 30.8%. The institution's average daily census
fell 19% between the second baseline year and the second program year. An ACP
directed by a clinical pharmacist trained in infectious diseases was associated
with improvements in inpatient length of stay and mortality. The ACP decreased
intravenous antimicrobial costs and facilitated the approval process for
restricted and nonformulary antimicrobial agents.
PMID- 10674781
TI - Clinical clerkships for Japanese graduate pharmacy students in U.S. medical
centers.
PMID- 10674782
TI - Oseltamivir phosphate.
PMID- 10674783
TI - Teleradiology in Europe.
AB - The new concept of teleradiology is centered on the consideration that it
involves management of medical information rather than the simple transmission of
diagnostic images from one location to another. Teleradiology must therefore be
able to contribute to the seamless integration of the digital environment in
which medical data are managed throughout and beyond the hospital, generating
value added services for the patients as well as prospective economical benefits
for the institution. In this perspective the evolution of telecommunication with
the spectacular success of mobile telephony and Internet will play and
increasingly important role, by allowing further development in the exchange of
multimedia medical information on a regional as well as international level.
However, new responsibilities are being given to the radiologists, who must take
all necessary technical and organizational actions in order to avoid that the
digital management of data may endanger the confidentiality and the integrity of
patients' data.
PMID- 10674784
TI - Management of change in health care organisations and human resource role.
AB - The paper is focused on the analysis of the most relevant factors necessary to
manage change in health care organisations. The approach suggested is the
Stakeholder one. According to this approach, the hospital's managers seem to be
successful if they are able to satisfy people (internal and external
stakeholders) that have a stake in the health care institution. The attention of
the author is mainly focused on the internal forces that make the health care
sector competitive and successful. In order to motivate internal human resources
to accept change and to achieve the organisational targets two main methods can
be suggested. The former is based on tangible variables and in particular on a
fair reward system; the latter is built on intangible elements e.g.
communication, negotiation, contracting, and organisational values sharing.
Moreover, in order to cope with change it is important to develop the information
technology management and to reengineer delivery processes, taking into
consideration both the costs and benefits of these kinds of innovations.
PMID- 10674785
TI - Organ doses, detriment and genetic risk from interventional vascular procedures
in Malaga (Spain).
AB - Nowadays, the radiological risk from simple X-ray procedures is well known. The
purpose of this work has been to estimate the population risk from digital
angiographic and interventional procedures and to compare it with the one from
simple procedures in the same population. The population risk has been estimated
according to the following quantities: genetically significant dose, somatic
significant dose, collective effective dose, annual per caput effective dose and
detriment. These have been estimated from dose area product and organ dose. Organ
dose values were estimated with the Eff-Dose software. A population of 605410
people were included in the study. In 1996, 1312 patients were to digital
interventional vascular procedures in Malaga, and 159 of them were selected in
this research project to obtain the dose area product and organ dose. The results
obtained for the quantities evaluated are: genetically significant dose, 4.1
microGy; somatic significant dose, 0.9 mSv; collective effective dose, 11.65
person-Sv: annual per caput effective dose, 0.02 mSv and detriment, 0.65
radiogenic cancers per year. These procedures supply a high radiation dose, so
they should have a greater contribution to population dose and risk than simple
examinations. However, our results indicate just the opposite.
PMID- 10674786
TI - A pilot study on the quality control of film processing in medical radiology
laboratories in Greece.
AB - The results of a pilot study on the quality of film processing in 80 medical
diagnostic radiology laboratories all over Greece are presented. The
sensitometric technique for the evaluation of processing has been used to
calculate film's base + fog, maximum optical density, speed and contrast,
parameters which describe the performance characteristics of automatic film
processors and films. The mean values of the base + fog and the maximum optical
density were well within the acceptance limits. The film speed was almost
constant while the film contrast showed significant variation.
PMID- 10674787
TI - Breast cancer screening; cost-effective in practice?
AB - The main aim of national breast screening is a reduction in breast cancer
mortality. The data on the reduction in breast cancer mortality from three (of
the five) Swedish trials in particular gave rise to the expectation that the
Dutch programme of 2-yearly screening for women aged 50-70 would produce a 16%
reduction in the total population. In all likelihood, many of the years of life
gained as a result of screening are enjoyed in good health. According to its
critics the actual benefit that can be achieved from the national breast cancer
screening programmes is overstated. Considerable benefits have recently been
demonstrated in England and Wales. However, the fall was so considerable in such
a relatively short space of time that screening (started in 1987) was thought to
only have played a small part. As far as the Dutch screening programme is
concerned it is still too early to reach any conclusions about a possible
reduction in mortality. The first short-term results of the screening are
favourable and as good as (or better than) expectations. In Swedish regions where
mammographic screening was introduced, a 19% reduction in breast cancer mortality
can be estimated at population level, and recently a 20% reduction was presented
in the UK. In countries where women are expected to make appointments for
screening themselves, the attendance figures are significantly lower and the
quality of the process as a whole is sometimes poorer. The benefits of breast
cancer screening need to be carefully balanced against the burden to women and to
the health care system. Mass breast screening requires many resources and will be
a costly service. Cost-effectiveness of a breast cancer screening programme can
be estimated using a computer model. Published cost-effectiveness ratios may
differ tremendously, but are often the result of different types of calculation,
time periods considered, including or excluding downstream cost. The approach of
simulation and estimation is here the same for all countries. The effects of a
breast-screening program depend on many factors, such as the epidemiology of the
disease, the health care system, costs of health care, the quality of the
screening programme and the attendance rate. The estimated CE-ratio ranges from
2650 euros per life-year gained in Navarra to 9650 in Germany. Although
relatively low incidence levels expected, the CE-ratio in Navarra is most
favourable probably due to a relatively unfavourable clinical stage distribution
before screening and the increasing incidence. The UK has a screening situation
that is almost similar with the Netherlands. Therefore, the CE-ratios of both
countries are comparable. The differences between countries make it impossible to
set up one uniform screening policy. The theoretical outcomes of the benefit that
can be achieved are generally from small-scale trials involving a limited number
of experts, persons examined, and areas. On a national scale, with hundreds of
professional practitioners, it can be expected to be more difficult to attain
uniform quality. Continuous quality control, monitoring and evaluation are
therefore crucial.
PMID- 10674788
TI - Dolichoodontoid. A rare cranio-cervical anomaly--MRI findings.
AB - The case of a 40-year-old woman with a dolichoodontoid, a rare congenital anomaly
of the cranio-cervical region, is presented. Due to summation image and overlying
bony structures, plain radiographs in two planes were inconclusive. MRI revealed
the hyperplasia of the odontoid process, allowed a grading of the subtype of this
disorder and demonstrated its relationship to the neural structures within the
foramen magnum and the upper cervical spine. Additional inflammatory disease,
suspected in this patient with long standing rheumatoid arthritis could be
excluded by MRI.
PMID- 10674789
TI - 3D MR angiography of the entire aorta: modified application of the body-phased
array coil for a single-shot technique.
AB - OBJECTIVE: Evaluation of different contrast-enhanced MR angiography imaging
protocols for visualization of the entire aorta in breath-hold technique. METHODS
AND PATIENTS: Three different CE (0.15 mmol/kg) MRA protocols were evaluated by
phantom and patient studies: (1) two separate MRA with conventional application
of the body-phased array coil; (2) a single-shot MRA with modified application of
the body-phased array coil; (3) a single-shot MRA with the body coil. Duplex
sonography, CTA and DSA were used as standard of reference. RESULTS: In all
examinations the entire aorta could be visualized. The best SNR was acquired with
protocol (1). The SNR of protocol (2) was reduced if the sagittal body diameter
of the patient was greater than 20 cm and decreased significantly with diameters
over 30 cm. By the use of protocol (3) the SNR was notably poor. The quality
scored for the visualization of the entire aorta was 97.5% (protocol 1); 92.5%
(protocol 2); and 80.0% (protocol 3). CONCLUSION: In most cases the modified
application of the body-phased array coil allows the imaging of the entire aorta
as a single-shot 3D CE MRA in diagnostic quality.
PMID- 10674790
TI - Real-time interactive virtual endoscopy of the tracheo-bronchial system:
influence of CT imaging protocols and observer ability.
AB - OBJECTIVE: To evaluate the influence of different spiral CT examination protocols
suitable for clinical use on image quality and to assess the observer dependence
in interactive real-time virtual bronchoscopy. METHODS AND PATIENTS: Real-time
perspective volume rendering of the airways in twenty normal patients based on
four different spiral CT examination protocols was evaluated by four observers in
regard to the order of depictable bronchi. RESULTS: Best results were obtained
using an examination protocol with a small beam collimation and a maximum pitch.
Depending on the observer's ability to control the fly path and the orientation
of the bronchi with respect to the slice plane up to sixth order bronchi could be
depicted. Inter-observer variability was up to two branching orders. CONCLUSION:
The performance of virtual bronchoscopy strongly depends on the applied CT
examination protocol and the observers experience with perspective volume
rendering. Both of which have to be taken into account when virtual bronchoscopy
is compared with fiberoptic bronchoscopy.
PMID- 10674791
TI - Solitary subependymal giant cell astrocytoma: case report.
AB - In this report, we describe a case of subependymal giant cell astrocytoma in a
patient lacking clinical symptoms of tuberous sclerosis. The absence of any
features of tuberous sclerosis initially dissuaded us from including subependymal
giant cell astrocytoma in our differential diagnosis.
PMID- 10674792
TI - Persistent hypoglossal artery associated with arteriovenous malformation: a case
report.
AB - A rare case of persistent hypoglossal artery in conjunction with arteriovenous
malformation was presented. MRA could delineate persistent hypoglossal artery and
arteriovenous malformation very clearly. The patient suffered from intracranial
hemorrhage from in the 37th week of pregnancy. MRI, MRA, angiography, and CT of
this rare condition are reported.
PMID- 10674793
TI - Laryngopyocele: signs on computed tomography.
AB - A laryngocele is an air-filled dilation of the saccule of the larynx. An infected
laryngocele is called a laryngopyocele. Our experience with a case of
laryngopyocele with signs on computed tomography before and after antibiotic
therapy is presented since laryngopyocele is more unusual.
PMID- 10674794
TI - Latent learning in medial temporal amnesia: evidence for disrupted
representational but preserved attentional processes.
AB - Damage to the hippocampus and medial temporal (MT) structures can lead to
anterograde amnesia and may also impair latent learning, in which prior exposure
to cues affects their subsequent associability. Normally, latent learning may
reflect both representational and attentional mechanisms. Prior work has
suggested that individuals with MT amnesia have specific deficits in
representational processing; thus, latent learning that invokes primarily
representational mechanisms might be especially impaired in MT amnesia. The
current results provide preliminary confirmation of this prediction. In
Experiment 1, a latent learning paradigm expected to invoke representational
mechanisms was impaired in individuals with MT amnesia, whereas in Experiment 2,
a paradigm expected to invoke other attentional mechanisms was spared in
individuals with MT amnesia. This suggests the representational and attentional
components of latent learning are dissociable and differentially affected in
anterograde amnesia.
PMID- 10674795
TI - Goal-directed selective attention and response competition monitoring: evidence
from unilateral parietal and anterior cingulate lesions.
AB - Competing visual stimuli lead to slower responses to targets. This response
competition must be resolved before correct responses are executed. Neuroimaging
suggests that response competition monitoring may be subserved by an integrated
neural network including the anterior cingulate cortex (ACC). In this study, 1
patient with a parietal lesion (Patient J.S.) and 1 with an ACC lesion (Patient
G.M.) were presented with 2 flanker tasks; 1 required verbal identification of
color targets, and the other required an opposite response to targets (e.g., see
red and say "green"); a control group was also tested. For controls, perceptually
incongruent flankers interfered with the ability to inhibit prepotent responses
to targets. Patient J.S. performed in a similar manner, even when flankers
appeared in the neglected field. Patient G.M. demonstrated reduced interference
effects for contralesional flankers. Results are discussed in terms of goal
directed selective attention and response competition monitoring.
PMID- 10674796
TI - Structural brain correlates of verbal and nonverbal fluency measures in
Alzheimer's disease.
AB - This study examined the relationships between regional brain volumes and
semantic, phonological, and nonverbal fluency in 32 participants with Alzheimer's
disease (AD). Object but not animal semantic fluency correlated with frontal and
temporal gray matter volumes. Phonological fluency was not significantly
associated with any brain volume examined. Nonverbal fluency was selectively
associated with bilateral frontal gray matter volumes. Hippocampal volumes,
although markedly reduced in these patients, were not related to any of the
fluency measures. Results lend evidence to the importance of the frontal lobes in
the directed generation of nonverbal and verbal exemplars by AD patients.
Furthermore, both left- and right-hemisphere regions contribute to the generation
of verbal and nonverbal exemplars.
PMID- 10674797
TI - The cerebral hemispheres cooperate to perform complex but not simple tasks.
AB - Three experiments were designed to examine whether task complexity determines the
degree to which a division of processing across the hemispheres (i.e., across
hemisphere processing) underlies performance when within- and across-hemisphere
processing are equally possible. When task complexity was relatively low,
performance in a midline condition that allowed for either within- or across
hemispheric processing resembled within-hemisphere performance (Experiments 1 and
2). However, when task complexity was high, performance in a midline condition
(Experiments 1 and 2) and a lateralized condition, which also allowed for either
within- or across-hemisphere processing (Experiment 3), resembled across
hemisphere performance. Results complement and extend prior work (e.g., M. T.
Banich & A. Belger, 1990) by indicating that the degree to which interhemispheric
cooperation underlies performance changes with the complexity of the task being
performed. This finding suggests that the hemispheres dynamically couple or
uncouple their processing as a function of task complexity.
PMID- 10674798
TI - Interhemispheric visual integration in three cases of familial callosal agenesis.
AB - Three cases of callosal agenesis (a 39-year-old woman and her 11- and 12-year-old
daughters) were tested on their ability to integrate visual information between
the visual hemifields. They were all able to name colors and digits in either
hemifield with high accuracy and were able to decide whether letters or digits in
opposite hemifields were the same or different. They had greater difficulty
deciding whether colors in opposite hemifields were the same or different. When
shown 6-letter words made up of pairs of 3-letter words that straddled the
midline (e.g., MANAGE, ROTATE), they responded to them as whole words and never
as 3-letter words, suggesting perceptual continuity across the midline, at least
for verbal material. The most likely interpretation is that the integration of
form, but not color, is achieved through the intact anterior commissure in these
participants.
PMID- 10674799
TI - Salivary testosterone concentrations in left-handers: an association with
cerebral language lateralization?
AB - The level of testosterone exposure in early brain development may influence the
direction or degree of cerebral language lateralization. Possible links between
individual differences in testosterone levels and patterns of speech
representation were investigated in 180 healthy young adults (97 left handed, 83
right handed) using the Fused Dichotic Words Test (T. Halwes, 1991). Among left
handed participants, significantly higher testosterone concentrations were
observed in individuals with a left-ear advantage on dichotic listening than in
individuals with a right-ear advantage. Among right-handed participants, the
pattern of group differences in testosterone tended to be reversed, resulting in
a statistically significant interaction. Results extend prior findings by S. D.
Moffat and E. Hampson (1996a) and raise the possibility that higher testosterone
is associated with patterns of brain organization in which speech and praxic
functions are lateralized to the same hemisphere.
PMID- 10674800
TI - Memory enhancement for emotional stimuli is impaired in early Alzheimer's
disease.
AB - Emotional arousal is associated with enhanced memory in neurologically intact
individuals, but it is unknown whether this effect is obtained in Alzheimer's
disease (AD). The current study compared emotional memory and emotional reactions
in patients with early AD and in older controls. Participants viewed emotionally
arousing (both pleasant and unpleasant) and neutral photographs while cognitive
and electrophysiological reactions were assessed. Memory was tested by free
recall and recognition. Emotional reactions were normal in the AD group, but the
emotional memory effect (enhanced memory for emotional vs. neutral stimuli) was
impaired. Recall results indicated that this effect was normal for pleasant
stimuli but abnormal for unpleasant stimuli. These results suggest that the
neural basis for the emotional memory effect may be disrupted in AD. Findings are
discussed in terms of the role of the amygdala in mediating emotional memory.
PMID- 10674801
TI - Age differences in explicit and implicit memory for pictures.
AB - In the present study, the authors examined age effects in memory for nonverbal
material. A picture fragment completion task was used to test explicit and
implicit memory in a younger and an older group. Explicit memory was indexed by
free recall of pictures, whereas implicit memory was indexed by perceptual
learning (priming). Both free recall and perceptual learning performance were
found to be impaired in the older group. A measure of executive functioning was
found to be predictive of both explicit and implicit memory.
PMID- 10674802
TI - Effects of aging on efficiency of task switching in a variant of the trail making
test.
AB - The Trail Making Test (TMT; R. M. Reitan, 1958, 1992) is extensively used in
research in neuropsychology and in aging, in part because it has been postulated
to reflect executive processes, such as planning and switching. However,
neurocognitive and individual-difference-based analyses of this test are
complicated because of different spatial arrangements of targets, the use of
letters only in Version B, and potential order effects when Version A is
administered prior to Version B. The present article examines a variant of a TMT
(called the Connections Test) that attempts to remedy these deficiencies. A
structural equation model suggested that there were no direct effects of age on
either the nonalternating or alternating versions of the Connections Test
(analogous to TMT Versions A and B, respectively); rather, all age-related
effects were mediated through effects on perceptual speed. Moreover, although the
nonalternating and alternating versions were strongly related to one another,
only the latter had significant independent relations with measures of higher
order cognition.
PMID- 10674803
TI - Verbal pragmatics following unilateral stroke: emotional content and valence.
AB - Verbal pragmatic aspects of discourse production were examined in 16 right brain
damaged (RBD), 16 left brain-damaged (LBD), and 16 normal control right-handed
adults. The facilitation effect of emotional content, valence hypothesis, and
relationship between pragmatics and emotion were evaluated. Participants produced
monologues while recollecting emotional and nonemotional experiences. Transcribed
monologues were rated for appropriateness on 6 pragmatic features: conciseness,
lexical selection, quantity, relevancy, specificity, and topic maintenance.
Overall, brain-damaged groups were rated as significantly less appropriate than
normals. Consistent with the facilitation effect, emotional content enhanced
pragmatic performance of LBD aphasic participants yet suppressed performance of
RBD participants. Contrary to the valence hypothesis, RBD participants were more
impaired for positive emotions and LBD participants for negative emotions.
Pragmatic appropriateness was not strongly correlated with a measure of emotional
intensity.
PMID- 10674804
TI - The impact of positive and negative feedback on reaction time in brain-damaged
patients.
AB - Little is known about the impact of feedback on the reaction times (RTs) of brain
damaged (BD) patients. The authors therefore investigated the effect of positive
and negative feedback on these patients, using a 4-choice RT task. Participants
were 107 BD patients with different etiologies and 50 orthopedic (OG) control
patients. Patients were assigned to 3 groups in which performance-independent
negative, positive, and no feedback were given. Statistical analysis showed that
negative feedback led to significantly shorter RTs in BD patients. Even BD
patients with high depression scores were affected by negative feedback. In
contrast, negative feedback had no impact on the RTs of the OG controls, and
positive feedback had no influence on the RTs of any group. These results raise
some interesting questions about motivational processes in BD patients.
PMID- 10674805
TI - Inhibitory tagging in inhibition of return is affected in schizophrenia: evidence
from the stroop task.
AB - L. J. Fuentes, A. B. Vivas, and G. W. Humphreys (1999b) showed that stimulus
processing is affected when stimuli are presented to locations subject to
inhibition of return. They argued that activated representations of stimuli
presented at inhibited locations are disconnected from their associated responses
through an "inhibitory tagging" mechanism occurring in inhibition of return. In
the present research, the authors asked whether such a mechanism is affected in
people with schizophrenia. Healthy adults and patients with schizophrenia
performed a Stroop task in an inhibition of return paradigm. Healthy adults
showed a reduction in the Stroop interference when stimuli were presented at
inhibited locations, a result that agrees with the inhibitory tagging mechanism
hypothesis and replicates previous findings. However, patients with schizophrenia
did not show such a reduction, a result suggesting that they have a deficit in
inhibitory processing occurring in inhibition of return.
PMID- 10674806
TI - Strategic processing and episodic memory impairment in obsessive compulsive
disorder.
AB - There is evidence that nonverbal memory problems in obsessive compulsive disorder
(OCD) are mediated by impaired strategic processing. Although many studies have
found verbal memory to be normal in OCD, these studies did not use tests designed
to stress organizational strategies. This study examined verbal and nonverbal
memory performance in 33 OCD patients and 30 normal control participants with the
Rey-Osterrieth Complex Figure Test and the California Verbal Learning Test. OCD
patients were impaired on verbal and nonverbal measures of organizational
strategy and free recall. Multiple regression modeling indicated that free recall
problems in OCD were mediated by impaired organizational strategies used during
learning trials. Therefore, verbal and nonverbal episodic memory deficits in OCD
are affected by impaired strategic processing. Results are consistent with
neurobiological models proposing frontal-striatal system dysfunction in OCD.
PMID- 10674807
TI - Review: tissue engineering for regeneration of articular cartilage.
AB - Joint pain due to cartilage degeneration is a serious problem, affecting people
of all ages. Although many techniques, often surgical, are currently employed to
treat this affliction, none have had complete success. Recent advances in biology
and materials science have pushed tissue engineering to the forefront of new
cartilage repair techniques. This review seeks to condense information for the
biomaterialist interested in developing materials for this application. Articular
cartilage anatomy, types of injury, and current repair methods are explained. The
need for biomaterials, current commonly used materials for tissue-engineered
cartilage, and considerations in scale-up of cell-biomaterial constructs are
summarized.
PMID- 10674808
TI - Surface-modification of polystyrene-microtitre plates via grafting of
glycidylmethacrylate and coating of poly-glycidylmethacrylate.
AB - Photografting of glycidylmethacrylate (GMA) onto commercially available
polystyrene-microtitre plates was carried out in methanol as well as butanol with
benzophenone (BP) as photoinitiator. Alternatively, prepolymers of
polyglycidylmethacrylate (PGMA) were synthesized in methanol with azo-iso
butyrodinitrile (AIBN) as initiator and dip-coated onto polystyrene-microtitre
plates. Both modification methods were tested in order to reach a high binding
capacity for proteins. Peroxidase was used as model protein. In addition, the
immobilization of myelin basic protein (MBP) to epoxy-modified microtitre plates
is shown and a MBP-based ELISA has been developed.
PMID- 10674809
TI - Titanium containing amorphous hydrogenated carbon films (a-C: H/Ti): surface
analysis and evaluation of cellular reactions using bone marrow cell cultures in
vitro.
AB - Amorphous hydrogenated carbon (a-C : H) coatings, also called diamond-like carbon
(DLC), have many properties required for a protective coating material in
biomedical applications. The purpose of this study is to evaluate a new surface
coating for bone-related implants by combining the hardness and inertness of a-C
: H films with the biological acceptance of titanium. For this purpose, different
amounts of titanium were incorporated into a-C : H films by a combined radio
frequency (rf) and magnetron sputtering set-up. The X-ray photoelectron
spectroscopy (XPS) of air-exposed a-C : H/titanium (a-C : H/Ti) films revealed
that the films were composed of TiO2 and TiC embedded in and connected to an a-C
: H matrix. Cell culture tests using primary adult rat bone marrow cell cultures
(BMC) were performed to determine effects on cell number and on osteoblast and
osteoclast differentiation. By adding titanium to the carbon matrix, cellular
reactions such as increased proliferation and reduced osteoclast-like cell
activity could be obtained, while these reactions were not seen on pure a-C : H
films and on glass control samples. In summary, a-C : H/Ti could be a valuable
coating for bone implants, by supporting bone cell proliferation while reducing
osteoclast-like cell activation.
PMID- 10674810
TI - Tissue responses to natural aragonite (Margaritifera shell) implants in vivo.
AB - The purpose of this study was to access tissue reactions to the outer prismatic
(prism) and the inner nacreous (nacre) layers of the fresh water Margaritifera
shell. The materials, in granule form, were implanted into the back muscles and
femurs of rats for 1, 2, 4, 8 and 16 weeks. In the back muscles, a foreign body
reaction was observed around the implants, starting from one week after
implantation and reaching maximal proportions at two weeks. After four weeks, a
thin layer of fibrous tissue encapsulated the implanted particles. The external
surface of the material stained strongly with acid fuchsin, indicating
degradation of implant. At femoral sites, newly formed bone was directly applied
to the implant surfaces. The outer-most parts of the organic sheets in prisms
were not degraded until 16 weeks after implantation and were embedded in the
newly formed bone. The interface between bone and the implants showed close
fusion by scanning electron microscopy (SEM). Energy dispersive X-ray analysis
(EDAX) demonstrated a phosphorous-rich zone in the interface between bone and the
implants, and no electron-dense layer in the interface was found by transmission
electron microscopy (TEM). We conclude that Margaritifera shells are
biocompatible, biodegradable and osteoconductive materials. Bonding between this
natural aragonite and bone seems to occur via a phosphorous-rich intermediate
layer.
PMID- 10674811
TI - Ion-beam-assisted deposition (IBAD) of hydroxyapatite coating layer on Ti-based
metal substrate.
AB - A hydroxyapatite layer was formed on the surface of a Ti-based alloy by ion-beam
assisted deposition. The deposition methodology comprised of an electron beam
vaporizing a pure hydroxyapatite target, while an Ar ion beam was focused on the
metal substrate to assist deposition. All deposited layers were amorphous,
regardless of the current level of the ion beam. The bond strength between the
layer and the substrate increased steadily with increasing current, while the
dissolution rate in a physiological saline solution decreased remarkably. These
improvements were attributed to an increase in the Ca/P ratio of the layer.
Without ion beam assistance, the Ca/P ratio was much lower than the
stoichiometric HAp (Ca/P = 1.67). With ion-beam assistance, the Ca/P ratio of the
layer increased presumably due to the high sputtering rate of P compared to that
of Ca from the layer being coated.
PMID- 10674812
TI - Fluoride release profiles of mature restorative glass ionomer cements after
fluoride application.
AB - This study investigates the fluoridation of four conventional glass ionomer
cements (GIC) (ChemFil Superior encapsulated, Fuji Cap II, Ketac-Fil and Hi
Dense) and three resin-modified GIC (RM-GIC) (Fuji II LC encapsulated, Photac-Fil
and Vitremer). The fluoride release of matured restorative GIC was measured as a
function of time, after four repeated fluoridations in a 2% NaF aqueous solution
for 1 h. This release was corrected for the intrinsic release as determined with
a control group. It was demonstrated that application of fluoride is capable of
recharging GIC but the subsequent high fluoride release only lasts for one or a
few days. Moreover, the fluoride release behaviour depends on the cement
formulation. Comparable to the intrinsic release, the net fluoride release after
fluoridation is composed of a short- and a long-term process, the former being
predominant after fluoridation. The total amount of fluoride released according
to the short-term process increases with consecutive fluoridations. This is
especially pronounced for the RM-GIC, who exhibit a relatively slow release after
fluoridation as compared to the conventional GIC. An explanation for these
results is suggested on the basis of the physicochemistry of the setting reaction
of the cements and of the fluoridation process.
PMID- 10674813
TI - Osseous tissue reaction around hydroxyapatite block implanted into proximal
metaphysis of tibia of rat with collagen-induced arthritis.
AB - This study was conducted to investigate the influence of osteoporosis on new bone
formation around a hydroxyapatite (HA) block implanted into the proximal
metaphysis of the tibia of rats with collagen-induced arthritis (CIA). Ten rats
were immunized with an emulsion of bovine type II collagen and Freund's complete
adjuvant (arthritis group). Another 10 rats, which were not immunized were used
as the control group. Seventeen days after immunization, HA block was implanted
into the proximal metaphysis of the tibia. Four weeks after implantation, all
rats were killed. The serum level of tetrate-resistant acid phosphatase (TRAP),
bone mineral density (BMD) in the proximal metaphysis of the tibia and the
affinity index in the arthritis group were 28.0+/-3.5 IU/ml, 130.3+/-28.7 mg/cm2
and 77.6+/-10.8%, respectively, and those in the control group were 24.6+/-5.5
IU/ml, 175.9+/-30.5 mg/cm2 and 56.3+/-14.8%. The serum level of TRAP was higher
(P < 0.05) and BMD was lower (P < 0.005) in the arthritis group. The amount of
new bone formation around the HA block was larger (affinity index, P < 0.05) in
the arthritis group than in the control group. These findings suggest that bone
formation around HA block might be enhanced even in conditions associated with
highly activated bone resorption and bone formation, such as arthritis.
PMID- 10674814
TI - Accelerated tissue regeneration through incorporation of basic fibroblast growth
factor-impregnated gelatin microspheres into artificial dermis.
AB - The objective of this study was to evaluate the effect of incorporation of basic
fibroblast growth factor (bFGF)-impregnated gelatin microspheres into an
artificial dermis on the regeneration of dermis-like tissues. When used in the
free form in vivo, bFGF cannot induce sufficient wound healing activity, because
of its short half-life. Therefore, sustained release of bFGF was achieved by
impregnation into biodegradable gelatin microspheres. A radioisotope study
revealed that incorporation of bFGF-impregnated gelatin microspheres
significantly prolonged in vivo retention of bFGF in the artificial dermis.
Artificial dermis with incorporated bFGF-impregnated gelatin microspheres or bFGF
in solution was implanted into full-thickness skin defects on the back of guinea
pigs (1.5 cm x 1.5 cm) (n = 4). Incorporation of bFGF into the artificial dermis
accelerated fibroblast proliferation and capillary formation in a dose-dependent
manner. However, the accelerated effects were more significant with the
incorporation of bFGF-impregnated gelatin microspheres than with free bFGF at
doses of 50 microg or higher. We conclude that the gelatin microsphere is a
promising tool to accelerate bFGF-induced tissue regeneration in artificial
dermis.
PMID- 10674815
TI - A long-term study of implanted artificial hydroxyapatite particles surrounding
the carotid artery in adult dogs.
AB - In this long-term study, we implanted HAP into adult dogs using a silicone
chamber attached to the carotid artery to clarify tissue reaction to HAP
implantation over a long period. We designed chambers and both hemispheres of the
chambers were filled with HAP particles, and were placed around both carotid
arteries of seven adult dogs. The implants were removed after 150, 300, 380 days,
and histological and ultrastructual examination was undertaken. We observed bone
like tissue which was formed where HAP particles were implanted.
Immunohistochemical findings showed that osteocalcin and osteonectin were as
positive in the bone-like tissue as in normal bone. This study suggests that
biological factors from the arterial wall might play an important role in new
bone-like tissue forming, and that HAP has a strong osteoconductive ability even
at heterogeneous sites.
PMID- 10674816
TI - PEG-variant biomaterials as selectively adhesive protein templates: model
surfaces for controlled cell adhesion and migration.
AB - Our study focused on the role of poly(ethylene glycol) (PEG) in actively
regulating the biological responsiveness of protein-adsorbed biomaterials. To
this end, we designed PEG-variant biomaterials from a family of tyrosine/PEG
derived polycarbonates to present surfaces ranging from low to intermediate
levels of PEG concentration, below the PEG level requisite for complete abolition
of protein adsorption. We analyzed the effect of PEG concentration on the amount,
conformation and bioactivity of an adsorbed model protein, fibronectin, and on
the attachment, adhesion strength and motility of L929 fibroblasts. Our results
demonstrate that low levels of PEG can regulate not only the extent but also the
conformation and specific bioactivity of adsorbed fibronectin. As the PEG
concentration was increased from 0 to 6 mol%, the amount of adsorbed fibronectin
decreased linearly yet the fibronectin conformation was altered such that the
overall bioactivity of adsorbed fibronectin was uncompromised. We report that the
degree of cell attachment varied with PEG concentration in a manner similar to
the dependence of fibronectin bioactivity on PEG. In contrast, the nature of cell
adhesion strength dependence on PEG paralleled the pattern observed for
fibronectin surface concentration. Our studies also indicated that the rate of
cell migration was inversely correlated with PEG concentration over a narrow
range of PEG concentration. Overall, these results highlight the striking ability
of PEG-variant biomaterials to systematically regulate the behavior of adsorbed
cell adhesion proteins and, consequently, effect cell functions.
PMID- 10674817
TI - Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis
IV: study of c-myc, c-fos and p53 mRNA expression.
AB - In order to investigate how cells recognize biomaterials, mRNA that was expressed
in attached human fibroblasts on various substrates was evaluated. The expressed
oncogenes (c-fos and c-myc) and tumor suppressor gene (p53) mRNA were then
isolated and detected using the RT-PCR method. As a result, c-fos and c-myc mRNA
expression varied with respect to differences in the hydrophilicity
hydrophobicity of the substrates. Both c-fos and c-myc mRNA expression were low
in the fibroblasts that had adhered to hydrophilic surfaces. The tendency of c
fos mRNA expression was similar to the adhesion curve of the cells. c-myc mRNA
was largely induced in fibroblasts that had adhered to hydrophobic surfaces. p53
mRNA were largely induced in fibroblasts that had adhered to hydrophilic
surfaces, while in the cells that had adhered to hydrophobic surfaces, p53 mRNA
expression was low. We concluded that the expression of oncogenes and p53 mRNA is
a powerful method for studying cell-polymer interactions or the evaluation of the
carcinogenic activity of biomaterials.
PMID- 10674818
TI - Microdomain structure in polylactide-block-poly(ethylene oxide) copolymer films.
AB - Structured surface is an important property of polymer biomaterials for tissue
engineering, for its capacity to expose domains with different surface energy and
functional groups. For this purpose, amphiphilic A-B-A block copolymers with
polylactide (PLA) as A blocks and poly(ethylene oxide) (PEO 3, Mn = 3090; PEO6,
Mn = 6110) as B block were synthesized by ring-opening polymerization of either L
lactide (L-LA) or DL-lactide (DL-LA), using poly(ethylene glycol)s as
macroinitiators and tin(II) octanoate (Sn(Oct)2) as a catalyst. Differential
scanning calorimetry (DSC) and electron microscopy were used to study the phase
separation of the hydrophobic (PLA) and hydrophilic (PEO) segments in films made
of the copolymers and their blends with high-molecular-weight PLA homopolymers.
Hydrophilic (PEO) and hydrophobic (PLA) domains were formed at the polymer film
surface due to the separation of phases. The phase separation was affected by the
copolymer composition and the stereoregularity of PLA blocks in the copolymers.
PMID- 10674819
TI - Autocrine nerve growth factor in human keratinocytes.
AB - Biologically active nerve growth factor (NGF) is synthesised and released by
proliferating normal human keratinocytes. NGF up-regulates the expression of NGF
mRNA in keratinocytes. Keratinocytes express both the low (p75)- and the high
affinity (TrkA) NGF-receptors, which are located in the basal layer of the
epidermis. K252, a specific inhibitor of trk phosphorylation, blocks NGF-induced
keratinocyte proliferation, in absence of exogenous NGF. Normal keratinocytes
over-expressing TrkA proliferate better than control transfectants, while the NGF
mimicking anti-Trk antibody induces an increased keratinocyte proliferation in
Trk over-expressing cells as compared to mock transfected keratinocytes. In
addition, NGF over-expressing keratinocytes proliferate better than mock
transfected cells. K252, by blocking TrkA phosphorylation, induces apoptosis in
normal keratinocytes, but not in keratinocytes over-expressing bcl-2.
Furthermore, NGF transfected keratinocytes are protected from UV-B-induced
keratinocyte apoptosis, by maintaining constant levels of Bcl-2 and Bcl-xL .
Taken together these results support the concept of an autocrine survival system
sustained by NGF and its high-affinity receptor in human keratinocytes. Because
NGF and Trk levels are highly expressed in psoriasis. one could speculate that
NGF autocrine system plays a role in the mechanisms associated with this and
other hyperproliferative skin conditions, including cancer.
PMID- 10674820
TI - Influence of aging and cell senescence on telomerase activity in keratinocytes.
AB - Telomeres, which exist in eukaryotic chromosome ends in specialized G-rich TTAGGG
structure, protect the ends from degradation or fusion. On the other hand,
telomerase is a ribonucleoprotein complex enzyme that synthesizes TTAGGG repeat
sequences at the ends of eukaryotic chromosomes. Previous studies suggested that
telomere length and telomerase activity cooperate in aging and immortalization of
cells. Here, we examined telomere length and telomerase activity in keratinocytes
from seven human subjects, including a patient with Werner's syndrome. Telomere
length in keratinocytes from healthy individuals was shortened with aging.
However, telomerase activity from an individual aged 42 years was reduced,
compared with that from a 0 year old individual. Passages of keratinocytes
reduced telomerase activity significantly in F2 and F3 keratinocytes from 0 and
42 year old individuals. Withdrawal of either EGF or amphiregulin from medium
resulted in down-regulation of telomerase activity. These results suggest that
telomere length and telomerase activity in primary cultured keratinocytes may be
one of the parameters for cell senescence. However, there remain obscure factors
such as ultraviolet-B radiation and growth factors.
PMID- 10674821
TI - Exclusion of linkage between dyschromatosis symmetrica hereditaria and chromosome
9.
AB - Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant pigmentary
disorder, first reported by Toyama in 1910. It is characterized by a mixture of
hypopigmented and hyperpigmented macules of various sizes on the backs of the
hands and feet. The disease gene of DSH and its chromosomal localization have not
yet been identified. A family with DSH and idiopathic torsion dystonia (ITD), a
rare neurological disease, was recently reported. Therefore, we speculated that
there was a linkage between the DSH gene and the ITD gene, named DYT1 and
localized on chromosome 9, and performed linkage analysis between DSH and
microsatellite markers on chromosome 9 in three Japanese DSH families (36
patients in total). We obtained a LOD score of < -2 over the whole region of
chromosome 9 encompassing DYT1. Thus, we conclude that there is no linkage
between DSH and DYT1 as well as any region of chromosome 9.
PMID- 10674822
TI - Fas/Fas ligand-mediated apoptosis of murine Langerhans cells.
AB - Epidermal Langerhans cells (LC) are potent antigen-presenting cells (APC), that
play a crucial role in initiating cutaneous immune responses. The Fas/Fas ligand
pathway has been implicated as an important cellular pathway in the regulation of
peripheral immunity. The morphologic, functional and phenotypic characteristics
of LC are becoming well-characterized. However, the mechanisms involved in
eliminating LC are poorly understood. In this report, we demonstrated that murine
epidermal LC constitutively express the Fas antigen (CD95) and the expression was
up-regulated by the addition of IFN-gamma in cultures. Interestingly, epidermal
LC underwent apoptosis by the addition of both recombinant soluble Fas ligand
(FasL) and IFN-gamma, but not by FasL alone. These results suggest that LC may
acquire the susceptibility to Fas-mediated apoptosis through up-regulation of the
Fas expression by IFN-gamma derived from activated T cells and that the
elimination of LC may be important for preventing excess cutaneous inflammatory
diseases.
PMID- 10674823
TI - Loss of heterozygosity of adenomatous polyposis coli gene in cutaneous tumors as
determined by using polymerase chain reaction and paraffin section preparations.
AB - It has been suggested that an alteration in the adenomatous polyposis coli (APC)
gene, which is a tumor suppressor gene, is one of the earlier events in
carcinogenesis of some adenocarcinomas. We undertook this study to determine the
prevalence of loss of heterozygosity (LOH) of the APC gene in several kinds of
cutaneous tumors. Fifty-seven unrelated Japanese patients were examined for
analysis of the APC gene. The 57 cases consisted of extramammary Paget's disease,
squamous cell carcinoma (SCC), eccrine poroma and porocarcinoma, metastatic tumor
of rectal adenocarcinoma and malignant melanoma. DNA was extracted from the tumor
and normal portions dissected from the formalin-fixed paraffin-embedding sections
and amplified with the use of the PCR. The amplified DNA was examined for LOH in
the APC gene. Seven samples of 32 heterozygous persons of APC gene (three out of
seven eccrine poromas, two eccrine porocarcinomas and two metastatic tumors of
rectal adenocarcinoma) showed for LOH in the APC gene. None of the heterozygous
samples from the extramammary Paget's disease (11), SCC (five) and melanoma
(five) showed LOH. These results suggest that tumor or tumor suppressor genes,
other than the APC gene, may be responsible for extramammary Paget's disease and
SCC and that LOH involving APC may have some relevance to the formation and
progression of eccrine tumors as in rectal tumors.
PMID- 10674824
TI - Production of tissue inhibitor of metalloproteinase-1 and -2 by cultured
keratinocytes.
AB - The imbalance between metalloproteinases and their inhibitors in tissue
remodelling is likely to play an important role in various pathologic conditions.
In order to understand the role of keratinocytes in regulating extracellular
matrix degradation in skin, we analyzed the production of metalloproteinase
inhibitors in keratinocytes. Tissue inhibitor of metalloproteinase-1 (TIMP-1) and
tissue inhibitor of metalloproteinase-2 (TIMP-2) mRNA were detected in cultured
human keratinocytes and mouse transformed keratinocyte cell line (KCMH-1) cells
by RT-PCR. On several column chromatography separation steps of the KCMH-1
conditioned medium, two specific inhibitors for mammalian collagenase were
purified showing an Mr of 29 kDa and an Mr of 22 kDa, respectively. The analysis
of their N-terminal amino acid sequence revealed that two inhibitors were TIMP-1
and TIMP-2. The final preparation of TIMP-1 had a specific activity of 56000 U/mg
and that of TIMP-2 had a specific activity of 26200 U/mg. Our results suggest
that keratinocytes take part in tissue remodelling in skin in secreting both TIMP
1 and TIMP-2.
PMID- 10674825
TI - Reconstruction of human hard-palate mucosal epithelium on de-epidermized dermis.
AB - Artificial hard-palate mucosa equivalents were reconstructed using keratinocytes
derived from normal human hard-palate and de-epidermized dermis. Reconstructed
hard-palate mucosal epithelium formed in three-dimensional culture was compared
to native hard-palate mucosal epithelium and reconstructed oral buccal mucosal
epithelium with regard to keratin expression. Artificial hard-palate mucosal
epithelium reconstructed in medium with delipidized serum showed a
differentiation pattern similar to that of hard-palate epithelium in vivo. The
present study also confirmed that keratinocytes derived from hard-palate mucosa
are intrinsically different from those of nonkeratinizing oral surfaces.
PMID- 10674826
TI - CD40 ligation inhibits trichilemmoma cell proliferation and induces IL-6
production.
AB - CD40 is a member of the tumor necrosis factor receptor superfamily expressed by B
cells, monocytes, dendritic cells, epithelial cells, and hematopoietic progenitor
cells. Recently, CD40 has been reported to also be expressed on human epidermal
cells. We have elucidated the function of CD40 on epidermal tumor cells and have
found that trichilemmoma (KTL-1) cells constitutively express CD40 and respond to
CD40 ligation by anti-CD40 mAb (EA-5) with a significant decrease in
proliferation. We were also able to demonstrate that KTL-1 cells respond to CD40
ligation by EA-5 with the up-regulation of interleukin-6 (IL-6) mRNA expression.
Together, the results suggest that CD40 on KTL-1 cells may function to regulate
their proliferation associated with the induction of IL-6 production.
PMID- 10674827
TI - Expression pattern of the bcl-2 homologous protein bad in normal skin, psoriasis
vulgaris and keratinocytic tumors.
AB - Previous investigations focused on the mechanisms and regulation of apoptotic
process have found that bcl-2 and its homologous proteins are central regulators
of the mitochondrial phase of apoptosis. Expression of several members of the bcl
2 family has been studied in various tissues including skin under normal as well
as disease conditions. In this report, we investigated the expression of bad, the
pro-apoptotic member of the BH3 subfamily, in normal and psoriatic epidermis,
keratoacanthoma, and basal and squamous cell carcinomas. Normal and psoriatic
epidermis showed accentuation of the staining in the lower suprabasal
compartment. A weak, predominantly diffuse staining pattern was observed in the
upper epidermis of psoriatic plaques. Keratoacanthoma showed strong but diffuse
immunostaining for pro-apoptotic bad, however we found only weak bad expression
in squamous cell carcinoma. Seven out of 15 basal cell carcinomas failed to
express bad protein. There was no correlation between bad positivity and depth of
tumour infiltration. Our observation suggests that the pro-apoptotic bad may
function as one of regulators involved in the maintenance of epidermal
homeostasis and this function could be altered depending on the disease state.
PMID- 10674828
TI - Firm stroking of human skin leads to vasodilatation possibly due to the release
of substance P.
AB - Many animal species invest a large amount of time in grooming behavior without
deriving any apparent benefit. In order for this behavior to have survived,
however, it must confer some survival advantage. In seven of eight humans tested,
an elevation in the skin's temperature was documented after massaging of the
cheeks of the face. The elevation of the skin's temperature reached a plateau
after about 40 min of massaging and was correlated to visible erythema. This
effect could be inhibited by repeated pretreatment of the skin with topical
capsaicin, a chemical that results in the release of substance P from peripheral
nerve endings. Thus, it appears that the temperature elevation induced by
stroking of human skin is controlled, at least in part, by release of the
neurotransmitter, substance P. In conclusion, it appears that the release of
neurotransmitter(s) may be the survival advantage that grooming confers to
animals.
PMID- 10674829
TI - Role of amniocentesis for the diagnosis of subclinical intra-amniotic infection
in preterm premature rupture of the membranes.
AB - The clinical role of amniocentesis in the management of pregnancies that are
complicated by preterm premature rupture of the membranes remains unclear. The
indiscriminant use of expectant management, corticosteroids, and empiric
antibiotic therapy without knowledge of the presence or absence of intra-amniotic
infection poses underappreciated risks to the fetus. This clinical opinion
presents the argument that amniocentesis should be an integral part of the
management of patients with preterm premature rupture of the membranes. The
technical aspects of amniocentesis, the associations between subclinical
infection and neonatal morbidity, and the limitations of current interventions
are reviewed, and suggestions for future studies that are sorely needed are
offered.
PMID- 10674830
TI - Ethical consideration of maternal participation in clinical research.
AB - This review explores some of the implications for a balanced approach to the
ethics of maternal participation in clinical research, from the perspective of
the fetus as a patient, which is a central concept in obstetric ethics. The
review therefore begins with an account of this topic, followed by an examination
of some of its ethical implications for a balanced approach to the ethics of
clinical research that involves pregnant women.
PMID- 10674831
TI - Life style, work and stress, and pregnancy outcome.
AB - Several environmental factors affect the fetus and thereby the outcome of
pregnancy. Recent studies have confirmed a relation between stress and pregnancy
outcome; furthermore they have indicated that biological measures of stress may
predict risk of complications. Altered sex ratio may be an interesting way of
measuring the effect of stress during pregnancy. Stress and work load during
pregnancy seem to be related to time until conception and to becoming pregnant
through assisted reproduction. Drinking large amounts of alcohol is hazardous,
but drinking one drink per day appears to be safe. The effect of passive smoking
continues to be a matter of debate.
PMID- 10674832
TI - Advances in management of Type 1 diabetes and pregnancy.
AB - Obstetricians will need to update themselves on the recent changes in terminology
and in diagnostic criteria for Type 1 diabetes mellitus. This still remains a
high-risk obstetric situation, in spite of optimistic reports from centres of
excellence. Pregnancy-associated hypertension may be closely related to insulin
resistance. A number of concepts and hypotheses are based on the central role of
insulin in fetal development.
PMID- 10674833
TI - First trimester screening for fetal abnormalities.
AB - The debate over the application of nuchal translucency measurement in Down's
syndrome screening is still unresolved in some clinicians' minds. Although
different authors report a range of sensitivities for Down's syndrome, none
question the validity of the association between increased nuchal translucency
and fetal aneuploidy. The published literature reveals a lack of congruence over
a standard, reproducible method for measuring nuchal translucency. Only with the
adoption of uniform methodology, and the establishment of international standards
for nuchal translucency measurement, is the true potential of this test likely to
be realized. The increasing use of first trimester ultrasound has focused
attention on the value of this investigation in confirming fetal viability,
estimation of gestational age, and screening for congenital abnormality. This
review summarizes the role of ultrasound and maternal serum biochemistry in first
trimester screening.
PMID- 10674834
TI - Physiologic basis of antenatal testing.
AB - Hypoxic injury accounts for approximately 20 to 40% of stillbirths in published
autopsy series. Antepartum fetal testing modalities can discriminate between the
fetus at risk for hypoxic injury and the normally oxygenated fetus. These
modalities have resulted in a significant reduction in this category of
stillbirths. The physiologic underpinning for the antepartum testing is reviewed
with a brief discussion of the two major approaches to testing.
PMID- 10674835
TI - General obstetrics.
PMID- 10674836
TI - Diabetic ketoacidosis in type 2 diabetes mellitus.
PMID- 10674837
TI - Cardiac involvement of female carrier of Duchenne muscular dystrophy.
PMID- 10674838
TI - Takayasu's arteritis and giant cell (temporal or cranial) arteritis.
PMID- 10674839
TI - Hepatic manifestations of the antiphospholipid syndrome.
PMID- 10674840
TI - HLA-B39 and asymmetric arthritis.
PMID- 10674841
TI - The occurrence of diabetic ketoacidosis in adults.
AB - OBJECTIVE: To analyze the occurrence of DKA in Chinese adults. METHODS AND
PATIENTS: We retrospectively reviewed the medical records of adults presenting
with DKA in a tertiary referral center from January 1992 to December 1997. We
classified these patients into 3 groups: type 1, type 2 and new-onset diabetes.
Clinical features and follow-up treatment were analyzed. RESULTS: One hundred and
twenty patients with 141 episodes of DKA were included; 77 episodes (54.6%) were
classified as being caused by type 2, 32 (22.7%) by type 1 and 32 (22.7%) by new
onset DM. The average age of type 2 patients was significantly higher. Of the 25
new-onset patients with follow-up for at least 12 months, 11 were not taking
insulin. Of these 11 patients, 6 had a family history of DM and 5 had BMI greater
than 26.4 kg/m2. The fasting plasma C-peptide values at various times of follow
up varied from 2.3 to 9.5 ng/ml in 6 of the 11 DKA-onset patients. CONCLUSION: In
type 2 patients, the occurrence of DKA is usually associated with old age and
another severe illness. "DKA-onset type 2 DM" reported in African-Americans and
in Japanese is also observed in Chinese.
PMID- 10674842
TI - Cardiorespiratory responses during cycle ergometer exercise with different ramp
slope increments in patients with chronic obstructive pulmonary disease.
AB - OBJECTIVE: The ramp exercise test has been widely used to evaluate
cardiopulmonary responses to an incremental exercise load. This study was
performed to clarify whether different slopes of the ramp exercise test influence
exercise tolerance, exercise limiting factors, and respiratory pattern in
patients with chronic obstructive pulmonary disease (COPD). SUBJECTS AND METHODS:
We applied three different slopes (5 W/min, 10 W/min and 20 W/min) of the ramp
exercise test in 9 patients with COPD and evaluated cardiopulmonary responses.
RESULTS: There were no significant differences in peak oxygen uptake, anaerobic
threshold (AT), minute ventilation, heart rate, arterial oxygen saturation,
expired tidal volume, or respiratory rate at the maximal load among the three
different ramp exercises tested. AT could be determined in six of nine patients
(67%) at the slope of 5 W/min, in 8/9 (89%) at the slope of 10 W/min, and in 9/9
(100%) at the slope of 20 W/min. CONCLUSION: The findings suggest that the ramp
slope does not affect exercise tolerance, exercise limiting factors, or
respiratory patterns and each of these ramp slopes is useful for the evaluation
of COPD. Ramp slopes of 10 W/ min or 20 W/min should be appropriate for the
determination of AT.
PMID- 10674843
TI - Chromogranin A expression in hepatocellular carcinoma in a patient with germline
MEN1 gene mutation.
AB - Hepatocellular carcinoma (HCC) was found in a patient with multiple endocrine
neoplasia type 1 (MEN 1). The intriguing finding was that the HCC in the patient
was positively stained for chromogranin A (CgA), a cellular marker for endocrine
and neuroendocrine tumors. The patient had a pancreas endocrine tumor and type C
hepatitis, that made pathological diagnosis of the origin of the tumor
complicated.
PMID- 10674844
TI - Endoscopic resection of small inflammatory fibroid polyp of the colon.
AB - Inflammatory fibroid polyp (IFP) is a solitary intestinal lesion of unknown
etiology. Although IFP is benign, laparotomy for the resection of colonic IFP is
performed in most cases because the polyp is usually large. We report a
successful endoscopic resection of cecal IFP. It is considered that colonic IFP
should be resected endoscopically if the polyp is small and is located
submucosally.
PMID- 10674845
TI - Right ventricular cardiomyopathy showing right bundle branch block and right
precordial ST segment elevation.
AB - A 73-year-old man who had a family history of sudden death, experienced syncope.
His electrocardiogram (ECG) presented right bundle branch block and right
precordial ST segment elevation which are findings identical with those in
Brugada syndrome. The cardiac MRI showed right ventricular mild dilatation, and
endomyocardial biopsy revealed fatty replacement of myocardial fibers. Though no
ventricular tachyarrhythmias were induced during an electrophysiologic test, the
effects on ECG of antiarrhythmic agents and autonomic modulations were similar to
those in Brugada syndrome. This case may suggest the relationship between Brugada
syndrome and right ventricular cardiomyopathy.
PMID- 10674846
TI - A female carrier of Duchenne muscular dystrophy complicated with cardiomyopathy.
AB - A 45-year-old female carrier of Duchenne muscular dystrophy (DMD) complicated
with cardiomyopathy is described. She had no symptoms of muscle weakness or heart
failure. Her chest X-ray film revealed marked cardiomegaly. Echocardiogram showed
marked enlargement and severe hypokinesis of the left ventricle. In myocardial
scintigraphic images, perfusion defects of the myocardium were revealed.
Dystrophin immunostaining of myocardial biopsy specimens showed a mosaic pattern
of dystrophin-negative and -positive fibers. Cardiomyopathy is sometimes the only
clinical symptom in female carriers of DMD. They are thought to be in a high risk
group for developing heart failure.
PMID- 10674847
TI - Successful catheter ablation against ventricular tachycardia associated with
myotonic dystrophy.
AB - Myotonic dystrophy (MD) is characterized by myotonia and muscular dystrophy and
cardiac involvement with tachy-arrhythmia is rarely encountered. We report a case
of MD complicated with severe left ventricular hypofunction and incessant
ventricular tachycardia (VT) with varying heart rates. The morphology of VT
suggested that it originated from the right ventricular outflow tract, and
electrophysiological study disclosed that the mechanism of VT was abnormal
automaticity. Catheter ablation was performed to treat this VT. The patient had a
cardiomyopathy with normal coronary arteries. The specimen of RV biopsy showed
moderate hypertrophy, mild fat infiltration and slight fibrosis. These findings
are histologically consistent with myotonic dystrophy.
PMID- 10674848
TI - Acute intermittent porphyria associated with transient elevation of transaminases
during an acute attack.
AB - A 44-year-old woman with acute intermittent porphyria (AIP) was admitted to
Kudanzaka Hospital because of abdominal pain. A cholecystectomy was performed in
another hospital without improvement. On admission, her transaminases were
elevated to greater than 1,000 mU/ml. After an intravenous drip of mainly
glucose, her transaminases returned to normal. Her acute attacks occurred during
stress, and she died of respiratory failure after repetitive acute episodes. AIP
should be included in a list of the differential diagnosis of gastrointestinal
diseases, neurosis, and hysteria. This is the first case of AIP accompanied by
transient marked elevation of transaminases during an acute attack.
PMID- 10674849
TI - Familial dysalbuminemic hypertriiodothyroninemia in a Japanese kindred.
AB - A 56-year-old Japanese housewife had been diagnosed as having Graves' disease and
was treated with methimazole. When she was referred to our hospital, the serum T3
level was high irrespective of high TSH level. High serum T3 levels were also
observed in two out of her three sisters. Electrophoresis revealed that binding
of 125I-T3 to serum albumin was markedly increased whereas the binding of 125I-T4
to serum albumin was slightly increased in the three sisters whose serum T3
levels were high. These data indicate that the presence of an albumin variant is
the cause of hypertriiodothyroninemia in this family.
PMID- 10674850
TI - Electrolyte disorders following massive insulin overdose in a patient with type 2
diabetes.
AB - We present a case of a 47-year-old man with Type 2 diabetes mellitus who
attempted suicide with 2,100 U of insulin injected subcutaneously. Administration
of dextrose intravenously was required to maintain the blood glucose
concentration normally for 5 days. Moreover, hypokalemia, hypophosphatemia, and
hypomagnesemia were also seen for 24 hours after insulin injection. The serum
phosphorus and magnesium concentrations decreased to nadirs of 1.6 mg/dl and 1.6
mg/dl respectively 7 hours after insulin injection. Electrolyte disorders other
than hypokalemia may be induced in hypoglycemic patients by massive insulin
overdose.
PMID- 10674851
TI - Results of surgery for a compound adrenal tumor consisting of pheochromocytoma
and ganglioneuroblastoma in an adult: 5-year follow-up.
AB - A rare, compound adrenal tumor consisting of ganglioneuroblastoma and
pheochromocytoma was completely resected in an adult woman. Most of the tumor was
occupied by the ganglioneuroblastoma component. This ganglioneuroblastoma was an
intermixed tumor, which is known to have a favorable prognosis in children. Based
on the lack of spread, the resectability of the tumor, and the histology of the
ganglioneuroblastoma, no adjuvant therapy was employed. There was no evidence of
recurrence at the 5-year follow-up. This suggests that adjuvant therapy may not
be necessary in these compound tumors.
PMID- 10674852
TI - Recurrent hemoptysis in tuberculosis with non-cavitary lung disease as a symptom
of mild hemophilia A in a young adult.
AB - Hemoptysis in patients with tuberculosis is usually associated with smear
positive and cavitary lung disease. The present case describes a patient
suffering from recurrent hemoptysis associated with tuberculosis who had smear
negative and non-cavitary lung disease, and who was subsequently diagnosed as
having mild hemophilia A. Although mild hemophilia A sometimes escapes detection
until adolescence, there has been no reported case of mild hemophilia A detected
by recurrent hemoptysis due to pulmonary tuberculosis. Here, we report a rare
case of recurrent hemoptysis in a patient with tuberculosis who had smear
negative and non-cavitary lung disease and who was finally shown to have
hemophilia A.
PMID- 10674853
TI - Acute eosinophilic pneumonia caused by cigarette smoking.
AB - It has been suggested that acute eosinophilic pneumonia (AEP) is associated with
cigarette smoking because in Japan, the patients with AEP are young and have a
high incidence of short-term smoking history. However, there has been no direct
evidence to support that cigarette smoke causes AEP. Herein is reported the first
case showing the direct evidence and a long-term clinical course of cigarette
smoking-induced AEP, in which tolerance to repeated resumption of smoking
cigarettes might have occurred. We should pay attention to the history of
cigarette smoking in seeing patients with AEP, especially in young patients.
PMID- 10674854
TI - Takayasu's arteritis in a 69 year-old woman.
AB - Takayasu's arteritis and temporal arteritis share many clinical and pathological
features. The most discriminatory feature between the two diseases is the age at
onset; the mean age at onset of the disease was reported as being 26 years for
Takayasu's arteritis and 69 years for temporal arteritis. Here we report a 69
year-old woman who presented with a weak right radial artery pulse. The ethnic
background and the presence of vascular insufficiency of the right upper
extremity and the absence of clinical signs such as shoulder stiffness and tender
scalp indicate that her diagnosis is Takayasu's arteritis. It must be emphasized
that the two conditions could be differentiated based on the clinical findings
even in a patient as old as 69 years old.
PMID- 10674855
TI - Sjogren's syndrome complicated with autoimmune hepatitis and antiphospholipid
antibody syndrome.
AB - A 56-year-old Japanese female simultaneously developed thrombocytopenia, sicca
symptoms, and an elevation of transaminase. Antiphospholipid antibodies were
detected in her serum. The presence of anti-SS-A antibodies in the serum and
sialectasis, disclosed by sialography, suggested the presence of primary
Sjogren's syndrome (SjS). The laboratory data and the biopsy of the liver showed
compatible findings with autoimmune hepatitis (AIH). Thrombocytopenia and liver
dysfunction satisfactorily responded to corticosteroid. To our knowledge, this is
the first reported case of SjS with AIH and antiphospholipid antibody syndrome
(APAS). Analysis of serum cytokine levels showed a predominance of Th0-Th1
response, which is not compatible with AIH, in this complicated autoimmune state.
PMID- 10674857
TI - Bilateral facial palsy following trigeminal zoster with zoster oticus.
PMID- 10674856
TI - A family with cases of adult onset Still's disease and psoriatic arthritis.
AB - Adult onset Still's disease is recognized as an adult variant of the systemic
form of juvenile rheumatoid arthritis, whose disease-predisposition is still
debated. On the other hand, the association between HLA subtypes and several
groups of seronegative arthritis including psoriatic arthritis has been well
documented. This report describes a family where adult onset Still's disease in a
young man and psoriatic arthritis in his father were seen. Both patients were HLA
B39-positive, which was likely playing important pathogenic roles in the latter
case. Clinical and immunological aspects of HLA-B39-related inflammatory diseases
are also discussed.
PMID- 10674858
TI - Overuse of granulocyte colony-stimulating factor in acute myeloid leukemia,
aplastic anemia and myelodysplastic syndrome.
PMID- 10674859
TI - Patent foramen ovale and "catastrophic" antiphospholipid syndrome.
PMID- 10674860
TI - Does amblyopia protect against age-related maculopathy?
PMID- 10674861
TI - Pseudoexfoliation syndrome in a patient with lattice corneal dystrophy.
AB - We report the case of a 70-year-old female who presents lattice corneal dystrophy
type I in association with pseudoexfoliation syndrome. This association has never
been reported in patients not affected by systemic amyloidosis.
PMID- 10674862
TI - The incidence of nontraumatic phakic rhegmatogenous retinal detachment in Split
Dalmatia County, Croatia.
AB - We studied the incidence of nontraumatic phakic rhegmatogenous retinal detachment
(RRD) in a defined population of Split-Dalmatia County, Croatia. In this clinic
based study, 272 of a population of 465,947 developed RRD during an 11-year
period (1988-1998). The annual incidence was, therefore, 5.3 per 100,000
population. The highest risk for RRD was between the ages of 60 and 69 years.
PMID- 10674863
TI - Ligneous conjunctivitis: a clinicopathologic study of 3 cases.
AB - The clinical, histopathologic features, and treatment outcomes in 3 patients with
ligneous conjunctivitis are described. Bilateral, idiopathic membranes occurred
in the palpebral conjunctiva in 2 patients. In 1 patient, unilateral conjunctival
changes occurred in the bulbar conjunctiva, at the site of pterygium excision.
Treatment included topical hyaluronidase, chymotrypsin, heparin, and cyclosporine
and surgical excision with limited or no success. In one patient, conjunctival
autografting from the normal fellow eye resulted in pseudomembrane formation at
the donor site in the previously unaffected eye. Histopathological evaluation of
excised membranes revealed the presence of amorphous eosinophilic hyaline
material and chronic inflammatory cells. Immunohistochemical study revealed a
predominance of T-lymphocytes. This case series confirms the recalcitrant
clinical course of ligneous conjunctivitis. Conventional treatment modalities
described in literature were not useful in the management of this condition.
Surgical manipulation of the unaffected fellow eye in patients with unilateral
disease can result in pathologic conjunctival changes, and is best avoided.
PMID- 10674864
TI - A case of episcleral neurofibroma.
AB - PURPOSE: To report a rare case of episcleral neurofibroma and discuss the
possible differential diagnoses. METHODS: Case report of a 36-year-old man who
presented with a painless epibulbar mass of the left eye. We describe the
clinical and histopathologic features of the tumour and compare it with other
tumours which may have a similar clinical presentation. RESULTS: An excisional
biopsy of the tumour was performed. Histopathologic examination revealed the
tumour to be an isolated episcleral neurofibroma. CONCLUSION: It is often
difficult to clinically differentiate this tumour from other conditions. Because
of the slow growth of neurofibromas and its slow risk of malignant
transformation, these lesions may be observed periodically for progression.
Surgical excision may be performed if the lesion is found to be progressively
enlarging in size.
PMID- 10674865
TI - Trabeculectomy: a retrospective follow-up of 700 eyes.
AB - A major focus of our study was to determine the value of postoperative
intraocular pressure (IOP) in predicting the outcome of trabeculectomy (TE). The
medical charts of 547 patients undergoing glaucoma filtering surgery at the
Department of Ophthalmology of the University of Cologne from 1987 to 1996 were
reviewed. The status of the visual field, level of visual acuity, appearance of
the bleb, cup/disc ratio and IOP were studied. Pre- and post-operative glaucoma
medication was recorded. The eyes with congenital glaucoma and those treated with
antimetabolites were excluded. The results are presented with particular emphasis
being placed not only on intraocular pressure (IOP) control but also on the
progression of glaucomatous damage (deterioration of visual field or disc damage)
and the decrease of visual acuity. The tonometric success rate of TE in
controlling the IOP < 21 mmHg was 61%. Defining the rigid criteria for success of
trabeculectomy as an IOP < 21 mmHg, no further visual field loss, no disc damage
and no additionally required surgical intervention due to glaucoma, the success
rate decreased to 44%. The results indicate that other factors than normalization
of IOP determine the success rate of TE. Should trabeculectomy be the therapy of
first choice in the early stage of glaucoma? Should trabeculectomy fail to
control the IOP in the first eye, would this allow options, such as the use of
antimetabolites in the second eye?
PMID- 10674866
TI - Why study vascular factors in glaucoma?
AB - There is clinical and experimental evidence that both increased intraocular
pressure and disturbed circulation are involved in the pathogenesis of
glaucomatous damage. Among the many factors discussed, decreased blood pressure
and vasospasm are the most important, and these factors may, at least in part, be
therapeutically influenced. The basic underlying disorder might be a vascular
dysfunction leading to local vasospasm and to systemic hypotension.
PMID- 10674867
TI - Cataract surgery: an analysis of patient satisfaction with medical care.
AB - INTRODUCTION: Patient satisfaction is a good performance indicator for measuring
the quality of health care delivered by hospitals. Satisfaction is understood to
be the positive difference between users' perceptions of their experience at the
moment of discharge and their expectations at the moment of admission. OBJECTIVE:
To evaluate the expectations and the perceived quality of care in cataract
surgery patients attending Hospital Clinic (HC). METHOD: A two-stage descriptive
study carried out at the HC in Barcelona, Spain. The target population consisted
of patients operated on for cataracts during the 1996 calendar year. Two study
groups were established: Group I, patients attending outpatient service before
admission; and Group II, patients attending outpatient service after surgery.
After informed consent was obtained, the patients were directly interviewed by
three researchers especially trained for that purpose. The questionnaire included
demographic variables and 31 questions related to expectations, all to be
answered by means of a 7 points Likert's visual scale. All statistical
calculations were performed using the SPSS program for Microsoft Windows.
RESULTS: A total of 148 interviews were performed: 80 (54.1%) in Group I and 68
(45.9%) in Group II. The mean age was 64.2 +/- 11.6 years. The difference between
scores at admission and at discharge was nearly significant (p = 0.064) for the
"information" component. CONCLUSIONS: The study of several fields where the
patient's expectations are higher or lower contributes to prioritizing efforts to
improve quality. There is a need for a frequent review and update of any patient
satisfaction evaluation tools that are used.
PMID- 10674868
TI - Uveoscleral outflow in dog's eye: role of several enzymes.
AB - The morphological pattern of several enzymes (succinic dehydrogenase--SDH,
glucose-6-phosphate dehydrogenase--G6PDH and lactic dehydrogenase--LDH) was
evaluated in normal dog eyes. Special attention was paid to the uveo-scleral
tissue. Cryostatic sections of dog eye were stained with toluidine blue for the
recognition of the microanatomical details or with histoenzymatic methods for
SDH, G6PDH and LDH activities using sodium succinate, glucose-6-phosphate and
sodium lactate as substrates respectively, nicotinamide adenine dinucleotide
(NAD) as a reducing agent and sodium nitro-blue-tetrazolium as a colouring
substance. A moderate positive reaction for SDH and a strong positive reaction
for LDH were observed in the uveoscleral tissue, while G6PDH gave negative
staining. Some considerations regarding a possible active role of these enzymatic
activities to the aqueous humor outflow are suggested.
PMID- 10674869
TI - Use of perfluorocarbon liquids, silicone oil, and 5-fluorouracil in the
management of experimental PVR.
AB - PURPOSE: To evaluate the toxicity and efficacy of 5-fluorouracil (5-FU) in
combination with perfluoroperhydrophenanthrene (Vitreon), silicone oil, or a
combination of silicone oil and Vitreon in a ratio of 3:2 in the management of
experimental proliferative vitreoretinopathy (PVR). METHODS: Toxicity study.
Seventy rabbit eyes underwent vitrectomy followed by intravitreal injection of 5
FU in doses of 800, 400, or 200 microg: Group 1, 5-FU alone; Group 2, 5-FU plus 1
mL Vitreon; Group 3, 5-FU plus 1 mL silicone oil; Group 4, 5-FU plus 0.6 mL
silicone oil and 0.4 mL Vitreon; Group 5, 0.6 mL silicone oil plus 0.4 mL
Vitreon. Electroretinography was performed preoperatively and 8 weeks
postoperatively before the animals were sacrificed. Efficacy study. Seventy-two
rabbit eyes underwent vitrectomy and were injected intravitreally with 100,000
200,000 retinal pigment epithelial cells to induce PVR. Groups were injected with
200 microg 5-FU alone or with 1 mL silicone oil, 1 mL Vitreon, or a combination
of 0.6 mL silicone oil and 0.4 mL Vitreon. Others were given only 1 mL Vitreon or
1 mL silicone oil. The animals were followed for 8-12 weeks; PVR was graded using
Fastenberg's system. RESULTS: Toxicity study. Eyes given 200 microg 5-FU,
silicone, and Vitreon showed mild inflammation and vitritis which resolved in 1
week; the dose was nontoxic by electroretinography and histopathology. Doses of
400 and 800 microg 5-FU were toxic. Efficacy study. Clinical severity of PVR was
less in the groups which received 5-FU plus vitreous substitutes when compared to
the control groups at all time points. The lowest incidences were in groups given
5-FU plus Vitreon or 5-FU plus Vitreon and silicone oil: 33.33% and 11.11%,
respectively. CONCLUSIONS: A dose of 200 microg 5-FU with silicone oil and
Vitreon combined was nontoxic to the rabbit retina. The combination of 5-FU,
Vitreon, and silicone oil showed significant efficacy in the prevention of
experimental PVR.
PMID- 10674870
TI - Are ophthalmic surgeons aware that starch powdered surgical gloves are a risk
factor in ocular surgery?
AB - PURPOSE: To assess the level of awareness among UK ophthalmic surgeons of the
potential risks from starch powdered surgical gloves during ophthalmic surgery
and to show by electron microscopy that starch granule contamination can occur
during ophthalmic surgery. SETTING: A sample (N = 46) of UK ophthalmologists from
the North of England, UK. METHODS: Type of glove usage and awareness of the
possible risks from starch powdered surgical gloves were assessed by means of a
questionnaire sent to ophthalmic surgeons in the North of England. The surface of
a polymethylmethacrylate (PMMA) intraocular lens (IOL) handled with a starch
powdered surgical glove was examined by electron microscopy for evidence of
starch contamination. RESULTS: Of the sampled ophthalmic surgeons (46), 89.1%
considered it important to use starch free surgical gloves and the 84.8% already
did so. Starch granule contamination was seen by electron microscopy on the
surface of a PMMA IOL which had been handled with starch powdered surgical
gloves. CONCLUSIONS: Although there has been sporadic attention in the ophthalmic
literature to the risks associated with starch powdered surgical gloves in
ophthalmology, up to 15% of UK ophthalmic surgeons may still be using starch
powdered gloves. The authors show that starch powder contamination of ophthalmic
materials can actually occur and remind ophthalmologists that this has been
reported in the literature as a possible cause of sterile intra and extraocular
inflammation.
PMID- 10674871
TI - Early results of punch trabeculectomy.
AB - PURPOSE: To evaluate the effectiveness of punch trabeculectomy in controlling
intraocular pressure (IOP) in patients with uncontrolled chronic open-angle
glaucoma (COAG) undergoing medical treatment. METHODS: This prospective study
included 22 patients (27 eyes) with uncontrolled COAC on medical treatment
undergoing punch trabeculectomy through a scleral tunnel. The tunnel was created
with a 3.5 mm keratome, the tunnel mouth was not sutured but the conjunctival
flap was sutured by 8/0 vicryl. The mean surgical time from opening the
conjunctiva to closing the conjunctiva was 8 m 59 s. IOP and other parameters
were checked on day 1 and subsequently at intervals appropriate to the
individual. RESULTS: After a mean period of 22.2 months follow-up the mean IOP
was 13.3 mmHg (SD 5.2). There were few transient early post-operative
complications; two eyes had a shallow anterior chamber (AC) due to excess
drainage, five had IOP above 21 mmHg, which responded to ocular massage, ten eyes
had hyphaema less than 1.5 mm and two eyes had no filtration bleb. CONCLUSIONS:
Punch trabeculectomy is a rapid and effective method of controlling IOP. The
complication rate is moderate and mainly transient.
PMID- 10674872
TI - The pure antiestrogen ICI 182780 is more effective in the induction of apoptosis
and down regulation of BCL-2 than tamoxifen in MCF-7 cells.
AB - There is increasing evidence that induction of apoptosis by antihormones is an
important mechanism in regard to their growth inhibitory action on hormone
dependent tumors. In this report we have compared the efficiency of tamoxifen
(Tam) and the pure antiestrogen ICI 182780 (ZM) to induce apoptosis in the
estrogen dependent breast cancer cell line MCF-7. Clear evidence for induction of
apoptosis could be demonstrated after treatment with both antiestrogens.
Application of the pure antiestrogen ZM led to a significantly higher induction
of apoptosis compared to the partial agonistic compound Tam. The ability of the
two compounds to induce apoptosis correlated with their growth inhibitory action.
On the molecular level administration of ZM led to a time dependent steady
decrease of BCL-2 mRNA and protein. Administration of Tam also initially
decreased the expression of BCL-2. In contrast to ZM treatment, BCL-2 expression
increased again after 8 h of incubation with Tam. After 96 h Tam treated cells
expressed BCL-2 levels nearly as high as untreated cells. In general, ZM
decreased BCL-2 levels more effectively than Tam. Our results demonstrate that ZM
and Tam possess quantitative and qualitative differences in their ability to down
regulate BCL-2 expression. The higher ability of the pure antiestrogen to down
regulate BCL-2 expression may explain the superiority of the pure antiestrogen to
induce apoptosis and to inhibit the growth of MCF-7 cells.
PMID- 10674873
TI - Mdm2 sensitizes MCF7 breast cancer cells to cisplatin or carboplatin.
AB - Overexpression of Mdm2 in cancer cells with otherwise wild-type p53 is believed
to be an alternative mechanism for p53 inactivation during carcinogenesis.
Because a number of genetic alterations that inactivate p53, including mutation,
homozygous deletion, or viral oncoprotein expression (e.g. HPV16-E6), inhibit DNA
repair, we tested the hypothesis that Mdm2 would likewise inhibit DNA repair.
Repair of cisplatin-induced DNA damage was reduced in MCF7 cells overexpressing
Mdm2, compared to MCF7 cells in which wild-type p53 function was intact. MCF7
Mdm2 cells exhibited preferential sensitivity to cisplatin and carboplatin. MCF7
Mdm2 cells showed a pronounced S-phase arrest after cisplatin treatment, similar
to that observed in mutant-p53 cells in the present and prior studies. MCF7 cells
with intact wild-type p53, on the other hand, arrested primarily in G2/M phase
after cisplatin treatment. These findings indicate that Mdm2 overexpression can
recapitulate the effect of p53 mutations on DNA repair of cisplatin lesions.
PMID- 10674874
TI - Immunohistochemical expression of internal and external ErbB-2 domains in
invasive breast cancer.
AB - We tested three ErbB-2 monoclonal antibodies (MoAbs) specific to the
intracytoplasmic internal domain (clone CB 11) and the extracellular glycosylated
peptide domain (clones CBE1 and Tab250) in 351 primary invasive breast
carcinomas. ErbB-2 immunodetection allowed us to differentiate three main groups:
group 1 (62.7%) lacked both MoAb ErbB-2 domains (erb -/-); group 2 stained for
both domains (erb +/+) (26.5%); group 3 stained for the internal domain only (erb
+/-) (10.8%). The relationships among these groups and nodal status (N) were
statistically significant, with N+ cases reaching the highest value (89.2%) in
the erb +/- group. Lack of immunostaining in the external domain thus seems to be
associated with increased metastatic spread. At variance analysis the difference
in hormonal receptor content between groups 1 and 3 was not significant; while
between groups 1 and 2 it was. The growth fraction of groups 2 and 3 was
significantly higher than that of group 1. Our results showed that anti-ErbB-2
MoAb clone CB 11 was able to detect a higher number of ErbB-2 expressing cases
than the two that are specific for the external domain (clones Tab 250 and CBE1).
Due to the strong association between group 3 cases and the highest metastatic
potential, this aggressive group could be identified only with the use of an
internal-domain specific MoAb CB 11, which thus seems to present a better
discriminative power as a diagnostic marker in the biopathological
characterization of breast carcinoma.
PMID- 10674875
TI - Survival from contralateral breast cancer.
AB - First primary, or unilateral, breast cancer (UBC) cases diagnosed in 1960-89 at
the Cancer Institute (WIA), Chennai, India were followed-up until December 31,
1994. Patients with UBC (n = 3163) and those who developed second cancer in the
contralateral breast (CBC) after the initial breast cancer (n = 67 or 2.1% of
UBC) were analysed. Compared to UBC patients, those who developed CBC were
younger at the time of diagnosis of initial breast cancer and had higher
frequency of breast cancer among the family members. The relative survival rate
takes into account competing causes of death and was estimated as the ratio of
observed survival rate to the expected survival rate. The cumulative relative
survival from UBC at 5 and 10 years were 51% and 41%, respectively, and the
corresponding rates for CBC were 47% and 30%; the survival difference seen
between UBC and CBC patients was not statistically significant. The survival
rates among younger, middle-aged and older women were significantly different
from each other in UBC but not in CBC patients. Both UBC and CBC with early stage
disease had a better survival compared to late stage disease. Survival advantage
was also seen among both UBC and CBC patients with family history of breast
cancer compared to those without. The multivariate analysis by the life table
proportional hazards model showed that the age at diagnosis is an independent
prognostic factor for breast cancer. The study results should be interpreted in
the light of small sample size of second cancers.
PMID- 10674876
TI - Bone marrow micrometastases in breast cancer patients.
AB - The presence of epithelial cells in bone marrow may be a prognostic factor in
breast cancer, and so we evaluated their evolution in treated and untreated
patients. A first bone marrow aspirate was obtained from 125 stage I/II breast
cancer patients at diagnosis and repeated every 6-8 months; the samples were
processed for leukocyte separation, used to prepare cytospin slides, stained with
a pool of monoclonal antibodies (MoAb) recognising epithelial antigens, and
immunocytochemically processed. The median follow-up was 48 months (range 15-82);
23 patients relapsed, and 14 died. MoAb positive cells were observed in 31.2% of
first, 24.3% of second, and 27.8% of third aspirates. In 68/100 pairs of
successive aspirates, bone marrow status remained unchanged; in 20 it became
negative, and in 12 positive (not statistically significant even after adjusting
for adjuvant therapy). An analysis based on Mantel and Byar's approach to time
dependent covariates using all 225 aspirates found no statistically significant
prognostic difference between the patients with negative and positive bone
marrow. Bone marrow status changed over time in about 1/3 of the patients;
adjuvant therapy did not affect the probability of its becoming negative or
positive. No significant association was found between bone marrow evolution and
relapse or death, but the relatively high probability of a change in status over
time cannot exclude the possibility that a positive aspirate during the course of
breast cancer may be a negative prognostic factor.
PMID- 10674877
TI - Prevention of rat mammary carcinoma utilizing leuprolide as an equivalent to
oophorectomy.
AB - A clinical trial is currently under way to examine the effectiveness of
leuprolide as a breast cancer chemopreventive agent and contraceptive. This
trial, as well as similar proposed studies, is based on the assumption that
leuprolide is as effective as surgical castration in preventing the onset of
mammary tumors; however, this has not been well documented in the DMBA animal
model. We directly compared leuprolide and oophorectomy in this model and
examined a combined therapy of leuprolide/bromocriptine. Twenty-seven day old
female Sprague-Dawley rats were randomly allocated into one of eight groups. All
rats received a 20-mg dose of DMBA at the age of 55 days. Group 1 (n = 10), no
treatment; Group 2 (n = 9), leuprolide (100 microg/kg/day) for eight weeks
beginning four weeks prior to DMBA; Group 3 (n = 10), oophorectomy four weeks
prior to DMBA with replacement estrogen beginning four weeks following DMBA.
Estrogen replacement was achieved with a 0.05-mg estradiol tablet releasing 0.833
microg/day over a 60-day period. Group 4 (n = 10), leuprolide (100 microg/kg/day)
initiated two weeks prior to DMBA and continuing for two weeks following DMBA;
Group 5 (n = 9), oophorectomy two weeks prior to DMBA with 0.05 mg of estradiol
in depot form, releasing 0.833 microg/day, beginning four weeks following DMBA
and continuing until week 16 of the study; Group 6 (n = 10), leuprolide (100
microg/kg/day) beginning two weeks prior to DMBA and continuing for the duration
of the experiment; Group 7 (n = 10), leuprolide (100 microg/kg/day) for eight
weeks beginning two weeks prior to DMBA; Group 8 (n = 9), leuprolide (100
microg/kg/day) and bromocriptine (83 microg/day) for eight weeks beginning two
weeks prior to DMBA. At nineteen weeks (15 weeks post DMBA), animals were
sacrificed and autopsies performed. One hundred percent of untreated animals
developed tumors. No animals undergoing oophorectomy four weeks prior to DMBA or
receiving leuprolide four weeks prior to and simultaneously with DMBA developed
tumors. In animals pretreated two weeks prior to DMBA with leuprolide or
oophorectomy, each group had one animal with tumor development. No tumors
developed in the animals receiving ongoing injections of leuprolide. However, one
tumor developed in those receiving leuprolide for the first eight weeks beginning
two weeks prior to DMBA administration. One animal receiving both leuprolide and
bromocriptine developed one tumor. We conclude that chemical oophorectomy (with
leuprolide) is as effective as surgical oophorectomy in inhibiting DMBA induced
carcinogenesis.
PMID- 10674878
TI - Mammaglobin B as a novel marker for detection of breast cancer micrometastases in
axillary lymph nodes by reverse transcription-polymerase chain reaction.
AB - A novel reverse transcription-polymerase chain reaction (RT-PCR) assay using
mammaglobin B gene was developed for detection of breast cancer micrometastases
in axillary lymph nodes. Fourteen primary breast cancers and 56 axillary lymph
nodes from six patients with primary breast cancer and 15 control lymph nodes
from non-cancer bearing patients were subjected to this assay. The transcript of
mammaglobin B gene was detected in none of the control lymph nodes, but in all of
the 14 primary breast cancers. Eleven out of the 56 lymph nodes from the
patients, which were shown to be positive by histological examination, were also
proven positive by this assay. On the other hand, fourteen of the 45 (31%)
histologically negative lymph nodes were also shown to express mammaglobin B
mRNA, which suggested the presence of micrometastases in these lymph nodes. RT
PCR using mammaglobin B gene could therefore be a useful tool for detection of
micrometastases of breast cancer.
PMID- 10674879
TI - Phase III trial of cyclophosphamide, epirubicin, fluorouracil (CEF) versus
cyclophosphamide, mitoxantrone, fluorouracil (CNF) in women with metastatic
breast cancer.
AB - BACKGROUND: The mitoxantrone combination CNF and the epirubicin combination CEF
have shown similar activity and less toxicity than the standard CAF combination
in metastatic breast cancer (MBC). A prospective randomised study was started to
compare safety and activity between CEF and CNF administered using a classical
chemotherapeutic schedule in MBC. PATIENTS AND METHODS: From December 1987 to
June 1993, 151 patients were randomised to receive cyclophosphamide (C) 100 mg m(
2) p.o. days 1-14, fluorouracil (F) 500 mg m(-2) i.v. days 1 and 8, and
epirubicin (E) 30 mg m(-2) i.v. days 1 and 8, or mitoxantrone (N) 6 mg m(-2) i.v.
days 1 and 8, every 4 weeks. Seventy-three patients were eligible for CEF and 72
for CNF. RESULTS: Objective responses were observed in 61.6% of the CEF group and
44.4% in CNF group (p = 0.004). The median duration of response was 64 weeks in
CEF and 50 weeks in CNF group (p = 0.02) and median time to progression was 51
and 33 weeks, respectively (p = 0.0004). At the time of analysis, all except six
patients (one in CNF and five in CEF) had died and the median survival time in
the CEF group was longer than in CNF (74.4 weeks vs 51.4 weeks; log-rank chi2
test p = 0.015). CNF produced more hematologic toxicity than CEF (WHO scale;
grades 2-4); leucopenia 84% vs 68% (p = 0.03) and thrombocytopenia 17% vs 4.5% (p
= 0.01); CEF caused more grade 2 and 3 alopecia: 93% vs 70% (p = 0.001).
CONCLUSION: The combination CEF using this schedule and dosage in metastatic
breast cancer is more effective with less toxicity than CNF, except for alopecia,
and was associated with longer survival.
PMID- 10674880
TI - Short and long-term effects on survival in breast cancer patients treated by
primary chemotherapy: an updated analysis of a randomized trial.
AB - A potential advantage of primary over adjuvant chemotherapy in breast cancer
survival had been proposed on theoretical grounds. In 1994, early results of the
S6-trial comparing primary chemotherapy vs. adjuvant chemotherapy for operable
breast cancer in 390 premenopausal patients had shown significant improvement in
survival of the primary chemotherapy arm (p = 0.04). An updated analysis
conducted in 1995 showed the disappearance of this difference between the two
arms (p = 0.18). In the present analysis, we investigated the potential short and
long-term benefits attributable to primary chemotherapy by applying weighted
logrank tests designed to assess specifically these effects. Results were
compared to those obtained with the classical logrank test. At a median follow-up
of 105 months, a significant short-term survival benefit (p = 0.02) in favor of
the primary chemotherapy has been shown. However, no long-term survival benefit
(p = 0.36) could be documented. The classical logrank test had revealed no
significant difference (p = 0.24) between the two groups but the proportional
hazard assumption being rejected (p = 0.04), the efficiency of this test can be
questioned. Results using the present analysis suggested that primary
chemotherapy delayed early death rates, without significantly modifying long-term
event rates. It emphasizes that a short-term effect which is not necessarily
associated with a long-term benefit may be seen at an early evaluation and
disappear later on.
PMID- 10674881
TI - Static disease on anastrozole provides similar benefit as objective response in
patients with advanced breast cancer.
AB - BACKGROUND: This paper reports on the clinical relevance of durable static
disease (SD) (> or = 24 weeks) in breast cancer patients treated with the
aromatase inhibitor anastrozole. PATIENTS AND METHODS: All patients were part of
two prospective, randomised, multicentre studies in postmenopausal women with
advanced disease in which megestrol acetate was compared with anastrozole 1 mg.
Survival from initiation of treatment was analysed by the response type, i.e.,
complete response (CR)/partial response (PR), static disease (SD) (> or = 24
weeks), or progressive disease (PD), achieved on therapy. RESULTS: Median
survival with anastrozole 1 mg was similar between patients who obtained CR/PR
and SD (> or = 24 weeks). Similarly, no difference in survival was observed in
patients treated with megestrol acetate who achieved CR/PR and SD. With both
treatments patients with CR/PR and SD had improved survival over those patients
with PD within 24 weeks. There was no difference between treatment arms for
patients showing PD within 24 weeks. CONCLUSIONS: These data confirm that durable
SD (> or = 24 weeks) is a clinically useful remission criterion in postmenopausal
women with advanced breast cancer with predictive value for overall survival. It
also confirms the value of this endpoint with anastrozole, a new generation
aromatase inhibitor.
PMID- 10674882
TI - Balance of cell proliferation and apoptosis in breast carcinogenesis.
AB - We determined the mitotic and apoptotic index through the spectrum of pre
invasive ductal breast lesions to invasive carcinoma in search of disturbances in
the proliferation/cell death balance in breast carcinogenesis. Seventy-two pure
pre-invasive ductal breast lesions (without invasive carcinoma) and 103 invasive
breast carcinomas were used. The numbers of mitotic and apoptotic cells were
microscopically counted in hematoxylin and eosin stained sections (MI and AI,
respectively), and the ratio of the values of MI and AI was calculated for each
individual case (M/A index). A distinction was made between well differentiated
and poorly differentiated breast lesions, based on histological type and nuclear
grade, to arrive at two plausible progression models for breast carcinogenesis.
For the well differentiated breast lesions, the MI was rather equal for
hyperplasias and well differentiated DCIS, but increased 6-fold from DCIS to well
differentiated invasive carcinoma. The AI remained in the same range, resulting
in a 4-fold increase of the M/A index. For the poorly differentiated breast
lesions, a significant increase in MI and AI was found from hyperplasia to poorly
differentiated DCIS. From DCIS to poorly differentiated invasive carcinoma, the
MI increased significantly and the AI decreased 2-fold (n.s.), resulting in a 2.5
fold significant increase of the M/A index. In conclusion, the net increase of
the number of cells in the transition from well differentiated pre-invasive to
well differentiated invasive carcinoma is accompanied by an increase of cell
proliferation rather than decrease in apoptosis, suggesting that in these
lesions, proliferation related mechanisms are most important in carcinogenesis
and progression. In contrast, in poorly differentiated breast lesions, decreased
apoptosis seems to be also important in carcinogenesis and progression. At
present, we are gathering patients with invasive breast cancer who had a previous
biopsy with a pre-invasive lesion to obtain further more direct evidence for this
hypothesis.
PMID- 10674883
TI - Involvement of nuclear steroid/thyroid/retinoid receptors and of protein kinases
in the regulation of growth and of c-erbB and retinoic acid receptor expression
in MCF-7 breast cancer cells.
AB - Nuclear steroid/thyroid/retinoid receptors and c-erbB membrane receptor tyrosine
kinases control epithelial growth and differentiation. Retinoid receptors can
dimerize with the vitamin D receptor, the glucocorticoid receptor or the thyroid
receptor. Furthermore, multiple c-erbB receptor dimers have been identified. It
has been shown that some of these receptor pathways communicate with each other
via cross-connected regulatory networks. Molecular interactions between retinoid
receptors or estrogen receptors (ER) and c-erbB-2, and between ER and retinoic
acid receptor(RAR)-alpha have been reported. Here, we demonstrate the effects of
steroids/thyroids/retinoids and of activators of protein kinase A (forskolin,
Forsk) and C (12-O-tetradecanoylphorbol-13-acetate, TPA), on growth and
expression of c-erbB and RARs in MCF-7 breast cancer cells, which contain high
levels of RAR-alpha and -gamma, and which express significant amounts of c-erbB-2
and -3. All trans-retinoic acid (tRA), the anti-estrogen ICI 182 780 (ICI), Forsk
and TPA reduced, whereas triiodothyronine and 17beta-estradiol (E2) stimulated
cell growth. Flow cytometry revealed that tRA and E2 reduced c-erbB-2 and -3,
whereas tamoxifen, Forsk and TPA up-regulated c-erbB-2. c-erbB-3 was co-regulated
with c-erbB-2. Northern analysis demonstrated that RAR-alpha was down-regulated
by dexamethasone, ICI, and TPA, whereas vitamin D3 and E2 up-regulated RAR-alpha.
RAR-gamma expression was less responsive to such treatment, being reduced only by
ICI and Forsk. These data indicate that nuclear receptor and protein kinase
signaling communicate with each other and control the expression of RARs and c
erbB receptors. Efficient growth control requires the coordinated interplay of
both receptor systems.
PMID- 10674884
TI - Research potential of a unique xenograft model of human proliferative breast
disease.
AB - A workshop on the 'Research potential of a unique xenograft model of human
proliferative breast disease' was held at the Karmanos Cancer Institute, Wayne
State University, Detroit, Michigan, in November of 1998. The accumulated
information and current experimental findings on the MCF10AT model of
preneoplastic, proliferative breast disease were reviewed. Discussions focused on
the relevance of the model to clinical breast cancer and on the most profitable
lines of further research to strengthen its utility.
PMID- 10674885
TI - Standardization and terminology of nocturia.
PMID- 10674886
TI - Lower urinary tract symptoms and nocturia in men and women: prevalence, aetiology
and diagnosis.
PMID- 10674887
TI - Similarities and dissimilarities between nocturnal enuresis in childhood and
nocturia in adults.
PMID- 10674888
TI - Nocturia: a disease or normal ageing?
PMID- 10674889
TI - Nocturnal polyuria.
PMID- 10674890
TI - Measuring the impact of nocturia on quality of life.
PMID- 10674891
TI - The impact of sleep deprivation caused by nocturia.
PMID- 10674892
TI - Health-economic issues in nocturia.
PMID- 10674893
TI - Nocturia: current knowledge and future directions.
PMID- 10674894
TI - Clonal diversity of Ig and T-cell receptor gene rearrangements in childhood B
precursor acute lymphoblastic leukaemia.
AB - The majority of paediatric B precursor acute lymphoblastic leukaemias in children
are derived from a single transformed haematopoietic cell with complete or
partial VDJ recombination within the immunoglobulin heavy chain gene. A high
frequency of patients also show rearrangements within TCRdelta and TCRgamma loci
and in up to 40% of children there is an excess of immune system gene
rearrangements compared with the number of identified alleles of immune system
genes, suggesting the presence of multiple leukaemic subclones -clonal diversity.
It has been observed by us and other investigators that in individual patients
the pattern of immune system gene rearrangements often changes between
presentation and relapse. In order to explore the possibility that clonal
diversity plays a biological role during disease progression we optimised methods
for subclone detection and analysed the prognostic significance of clonal
diversity among 75 children with B precursor-ALL. Our results suggest that clonal
diversity plays a role in disease progression as patients with oligoclonal
disease showed a significantly shorter disease free survival than patients with
monoclonal disease. This trend was of particular importance in the 'standard
risk' group of ALL where aggressive disease could not be recognised by other
means. In addition, generation of independent subclones from an early, non
rearranged tumour progenitor appears to be a common feature among leukaemias with
aggressive clinical behaviour. We speculate on the type of genetic factors which
may participate both in the generation of subclones and also in wider genomic
instability and which are likely to be required for the aggressive clinical
phenotype in children with ALL.
PMID- 10674895
TI - Chronic lymphoproliferative disorders: an integrated point of view for the
differential diagnosis.
AB - Morphology is regarded as the principle basis for the identification of lymphoid
neoplasms. Sometimes, however, it fails to discriminate among several chronic
lymphoproliferative disorders (CLDs). Improved immunophenotyping has resulted in
a better characterization of a number of variants of these diseases, some of
which may benefit from different therapeutic approaches. In particular, the
proposal of scoring systems using a panel of monoclonal antibodies (MoAbs) has
represented a critical step in this field. In fact, to date, some MoAbs (CD5,
CD23, FMC7, CD22, CD79b, and surface immunoglobulin density) are able to
distinguish among several entities, thus allowing for a correct diagnosis in the
majority of cases. However, there is still a small percentage of patients where
the combined diagnostic approach (morphology and immunophenotyping) should be
further refined by other techniques, such as cytogenetic and molecular
characterization. Here numerous questions are raised indicating the need to more
accurately differentiate the disease entities under discussion and better
understand some of their clinical manifestations.
PMID- 10674896
TI - Diagnosis and treatment of polycythemia vera and possible future study designs of
the PVSG.
AB - The present study describes clinicopathological criteria to distinguish the 5
sequential stages proposed by Wasserman et al in the natural history of newly
diagnosed PV patients. The European Working Group on MPD (EWG.MPD) extended and
modified the PVSG diagnostic criteria of PV by including bone marrow
histopathology. From the results of prospective randomized studies in PV it
became evident that new clinical trials in previously untreated PV patients
should focus on comparing interferon-alpha, a non-leukemogenic approach, versus a
potential leukemogenic myelosuppressive treatment modality. Hydroxyurea appears
to be the least leukemogenic myelosuppressive agent in long-term prospective
clinical PV-studies extending observation periods of more than 10 years. The
rational for using IFN-alpha as a first-line treatment option in newly diagnosed
PV-patient include its effectiveness to abate constitutional symptoms and to
induce a complete remission thereby avoiding phlebotomy, iron deficiency, and
macrocytosis associated with hydroxyurea. Moreover IFN-alpha may prevent or delay
the development of postpolycythemic myelofibrosis if used early in the course of
the disease. Clinicians will be reluctant to postpone the use of hydroxyurea in
early stage PV as long as a conservative approach using phlebotomy aiming at a
hematocrit below 0.45, plus low-dose aspirin for the control platelet function or
anagrelide for the control platelet number is used to keep the patient healthy.
Low-dose aspirin will prevent the microvascular thrombotic complications of
thrombocythemia associated with PV in remission after phlebotomy, but lacks
myelosuppressive activity. Control of megakaryocyte maturation and reduction of
platelet production to normal (<400 x 10(9)/l) by relatively low doses of
anagrelide will predict a significant reduction of vascular complications in the
early stages of PV, may prevent progression to myelofibrosis during follow-up of
PV and very probable will postpone the use of hydroxyurea treatment for
controlling the platelet count in PV. Large scale randomized clinical trials in
PV are proposed, which should aim not only for clinical and hematological
response, safety, efficacy, but should also assess toxicity, the need for
phlebotomy and whether the development of progressive disease such as
splenomegaly, pruritus, myelofibrotic myeloid metaplasia, spent phase,
myelodysplasia and acute leukemia can be delayed or prevented by IFN-alpha as
compared to a conservative approach of phlebotomy plus low-dose aspirin or
anagrelide followed by hydroxyurea when signs of myeloproliferative activity
became evident.
PMID- 10674897
TI - CD40 and B chronic lymphocytic leukemia cell response to fludarabine: the
influence of NF-kappaB/Rel transcription factors on chemotherapy-induced
apoptosis.
AB - The levels of tumour necrosis factor receptor (TNF-R) superfamily members can be
altered in lymphoid leukemias, indicating a possible role of such molecules in
the biology of these neoplasias. In B chronic lymphocytic leukemia cells, the
CD40/CD40L system has been shown to be effective in inhibiting the apoptotic
response to fludarabine. The modulation of apoptosis relied on the CD40-induced
activity of NF-kappaB/Rel transcription factors. The anti-apoptotic effect of
CD40 was abolished using a phosphorothioate kappaB decoy oligodeoxynucleotide.
These findings illustrate an example of the biological activity of TNF-R-like
molecules in leukemias. They also show the influence of NF-kappaB/Rel activity on
leukemic cell response to apoptogenic agents.
PMID- 10674898
TI - Outcome of Philadelphia chromosome-positive adult acute lymphoblastic leukemia.
AB - Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL)
represents the most common cytogenetic abnormality in adult ALL. It is found in
15% to 30% of patients, and its incidence increases with age. As in children,
prognosis in Ph-positive adult ALL is poor. No therapeutic approach has had
substantial impact on its unfavorable course. We analyzed the characteristics and
outcome of newly diagnosed adults with Ph-positive ALL treated at the M. D.
Anderson Cancer Center between 1980 and 1997. The diagnosis of patients was based
on typical morphological and immunophenotypic criteria of marrow aspirate and
biopsy specimens. Cytogenetic and molecular studies were also performed. A total
of 67 patients were included in this study. From 1980 until 1991, 38 patients
with Ph-positive ALL were treated with vincristine, Adriamycin, and dexamethasone
(VAD), or with acute myeloid leukemia (AML)-like induction protocols. Since 1992
a total of 29 patients received induction therapy with an intensified treatment
protocol, called "hyper-CVAD". The outcome of patients treated with standard and
intensified treatment regimens was compared and results of our institution
contrasted with data obtained from other centers. Ph-positive ALL was present in
67 of 498 patients with newly diagnosed ALL (13%). Patients with Ph-positive ALL
had a higher median age (44 versus 34, P=0.007), higher median white blood cell
(WBC) counts at presentation (25 versus 8, P=0.0002), and higher peripheral
median percentage of blast counts (63 versus 40, P=0.023). FAB subtype L2 (70%
versus 49%, P=0.001) and CALLA-positive pre-B immunophenotype (75% versus 37%,
P<0.001) predominated among Ph-positive ALL. Myeloid marker coexpression was more
frequent in Ph-positive ALL when compared with Ph-negative ALL (52% vs. 27% for
CD13, P<0.001, and 44% vs. 27% for CD33, P=0.005). Among patients treated with
hyper-CVAD, the complete remission (CR) rate was 90% versus 55% (P=0.002) with
pre-hyper-CVAD regimens (VAD and AML-like induction protocols), the median CR
duration was 43 weeks versus 32 weeks (P>0.5), median disease-free survival (DFS)
was 42 weeks versus 29 weeks (P=0.008), and median survival was 66 weeks versus
45 weeks (P>0.5). Patients with hyperdiploid Ph-positive ALL on hyper-CVAD
therapy achieved significantly longer CR duration and DFS than hypo- and
pseudodiploid cases (59 weeks versus 42 and 31 weeks, P=0.02 and 0.04,
respectively). In contrast, patients treated with regimens prior to hyper-CVAD
had significantly shorter CR duration (21 weeks versus 33 and 29 weeks, P=0.03)
and DFS with hyperdiploid karyotypes when compared to pseudodiploid and
hypodiploid cases (16 weeks versus 30 and 13 weeks, P=0.008). In conclusion, our
results demonstrate improved response rate and DFS with current intensive
regimens (hyper-CVAD) in patients with Ph-positive ALL, but no advantage in
overall survival.
PMID- 10674899
TI - Aberrant immunophenotypes detected by flow cytometry in acute lymphoblastic
leukemia.
AB - The present study was designed to analyse the proportion of ALL patients in which
the phenotypic detection of minimal residual disease (MRD) is feasible, based on
the presence of aberrant phenotypes: lineage infidelity, asynchronous expression,
overexpression and ectopic phenotype. For this purpose we have prospectively
investigated the phenotype of blast cells from 25 patients at diagnosis using a
large panel of monoclonal antibodies by multiparametric flow cytometry. The mean
age was 23.3 +/- 17.3 with 10 children and 15 adults. 14 patients were classified
as L1, 9 L2 and 2 L3 according to the FAB classification. 17 cases were B-lineage
ALL and 8 T-ALL. 23 out of 25 cases (92%) included in this study displayed
phenotypic aberrations at diagnosis (15 out of 17 cases of B-lineage ALL and all
T-ALL patients). 76% of patients displayed two or more than two aberrancies. The
phenotypic aberrations were lineage infidelity, found in 12 patients,
asynchronous antigen expression detected in 17 patients, antigen overexpression
in 4 patients and ectopic phenotype in 7 patients. In summary our results show
that when a large panel of MoAbs is used for the immunophenotypical
characterization of ALL, most patients display aberrant phenotypes, the
coexistence of more than two aberrant antigen expressions being frequently
detected. These results suggest that the use of immunological methods for the
detection of MRD in ALL based on the existence of aberrant phenotypes could be of
great help for the follow-up of patients in complete remission.
PMID- 10674900
TI - Analysis of Wilms tumor gene (WT1) expression in acute leukemia patients with
special reference to the differential diagnosis between eosinophilic leukemia and
idiopathic hypereosinophilic syndromes.
AB - Continuous Wilms' tumor gene (WT1) expression is a typical feature of leukemic
blasts in AML, ALL, and blast crisis CML patients. It is easily detectable by a
variety of RT-PCR protocols, which differ mainly in their sensitivity. The
nuclear WT1 protein can be found in blasts of approximately 50-60% of acute
leukemia patients at diagnosis. Conversely, WT1 is only transiently expressed in
normal hemopoiesis. Early CD34+ hemopoietic progenitors express WT1, whereas no
WT1 mRNA transcripts can be found in mature blood cells and differentiation
induced committed CD34- progenitors. As a powerful complementary diagnostic tool,
testing for WT1 expression can be helpful to discriminate between eosinophilic
leukemia (EoL) patients and patients with idiopathic hypereosinophilic syndromes.
Conflicting data about the usefulness of testing for WT1 expression to monitor
minimal residual disease (MRD) in treated leukemia patients will be discussed.
Finally, research strategies to circumvent shortcomings in detecting leukemia
associated WT1 expression will be outlined.
PMID- 10674901
TI - Bone marrow features and clinical findings in chronic myeloid leukemia--a
comparative, multicenter, immunohistological and morphometric study on 614
patients.
AB - A multicenter, immunohistochemical and morphometric study was performed on
diagnostic pretreatment bone marrow biopsies in 614 adult patients with Ph1+
chronic myeloid leukemia (CML) to compare histological features with clinical
findings. For identification of megakaryopoiesis we used the monoclonal antibody
CD61 and additionally the PAS reaction to determine the subfraction of atypical
micromegakaryocytes and precursors. Labelling of erythroid precursors was carried
out by a monoclonal antibody directed against glycophorin C. In order to
selectively stain macrophages and their activated subset we applied CD68 and the
GSA-I lectin. Density of argyrophilic fibers (reticulin plus collagen) was
measured following Gomori's silver impregnation method. In accordance with
laboratory data morphological variables revealed a comparable amount of
congruence in the various groups of CML patients derived from different sources.
In about 26% of patients early (reticulin) to advanced (collagen) fibrosis was
detectable. Significant correlations were calculated between the extent of
myelofibrosis with splenomegaly, anemia and increasing numbers of erythroblasts
and myeloblasts in the peripheral blood count. These features were assumed to
indicate more advanced stages of the disease process with ensuing transition into
myeloid metaplasia and consequently were associated with an unfavorable
prognosis. Significant relationships were revealed between the number of CD61+
megakaryocytes and more important, also their precursor fraction with the degree
of fibrosis. This result extends previous experimental findings regarding the
impact of immature elements of this cell lineage for the generation of
myelofibrosis. The significant association of erythroid precursors with the
number of mature (resident) macrophages including their activated GSA-I subset
may shed some light on their functional involvement in iron turnover and
hemoglobin synthesis. A modified histological classification of predominant bone
marrow features is introduced. This simplified synthesis staging system (Cologne
Classification) is not only associated with certain sets of laboratory data, but
also with different survival patterns.
PMID- 10674902
TI - Diagnostic and clinical implications of lineage fidelity in acute leukemia
patients undergoing allogeneic stem cell transplantation.
AB - We report on a series of five acute leukemia patients who have undergone
allogeneic bone marrow transplantation. Initially, these patients were classified
as having biphenotypic leukemia; however, subsequent developments in the
perception of what constitutes lineage fidelity has resulted in controversy
regarding the diagnosis. Flow cytometry and non-random cytogenetic results have
had a major impact on redefining the concept of biphenotypic disease. In this
report we review the diagnostic dilemma associated with defining acute leukemia
lineage fidelity as diagnostic techniques evolve. While our unique focus on the
treatment of biphenotypic leukemia patients represents a small population, we
verify the single most promising therapy where otherwise the diagnosis is dismal.
PMID- 10674903
TI - Feasibility of high-dose chemotherapy without stem cell support as a first-line
treatment for non-Hodgkin's aggressive lymphoma: a pilot study.
AB - A regimen which incorporates cyclophosphamide, doxorubicin, vincristine and
prednisolone (CHOP) is the standard treatment for patients with non-Hodgkin's
lymphoma (NHL), but it has not been effective in patients with aggressive NHL who
are at high risk. The aim of the present trial was to investigate the feasibility
of high-dose chemotherapy (HDC) without stem cell support as a first-line
treatment. The primary endpoint was a complete remission rate. The second
endpoint was survival. Fourteen patients with aggressive NHL entered the study
and were treated according to the K93 protocol (3 cycles of CHOP, high-dose
etoposide and ifosfamide, and high-dose methotrexate) Eleven patients (79%)
achieved complete remission (CR) and two (14%) achieved partial remission (PR).
Overall survival (OS) after five years was 79%. The actuarial five year disease
free survival (DFS) for the eleven cases of CR was 75%. During chemotherapy,
grade IV hematologic toxicity was observed in all patients and grade IV non
hematologic toxicity in only one patient, who experienced oral ulcers. Peripheral
blood stem cell (PBSC) apheresis was performed in eight cases. One harvesting was
enough to provide an adequate number of CD34+ cells for the subsequent PBSC
transplantation (PBSCT). In conclusion our study confirmed the efficacy of the
K93 protocol in obtaining a good response (CR + PR) rate and a very good DFS rate
in most cases of aggressive NHL, with acceptable toxicity. This regimen may
improve the outcome in cases of aggressive NHL without stem cell support. It
seems worthwhile to conduct a randomized controlled study comparing the K93
protocol with the standard CHOP regimen.
PMID- 10674904
TI - Feasibility of autologous stem cell transplantation in chronic carriers of
hepatitis B and hepatitis C virus.
AB - There are several reports describing acute liver decompensation in chronic
carriers of HBsAg after withdrawal of chemotherapy or immunosuppressive therapy;
recently the same was also reported for chronic HCV-RNA carriers. We
retrospectively evaluated hepatic toxicity in eleven patients (6 carriers of HCV
RNA and 5 of HBsAg) autotransplanted at our Institution between March '92 and
June '98. Male/female ratio was 7/4, median age 41 years (26-56). Nine patients
(4 HBsAg) were affected by non-Hodgkin's lymphoma, 1 (HCV-RNA) by chronic
myelogenous leukaemia and 1 (HBsAg) by breast cancer. In the immediate post
transplant period in only 1 patient (HBsAg carrier and affected by breast cancer)
was hepatitis documented (at about 1 month from transplant) with an elevation of
transaminase levels (x20-40 n.v.). Neither other complications, nor toxic deaths
were observed. During the post-transplant follow-up (median 31 months, range 9
83) no hepatic abnormalities were observed. All patients are alive at 56 months
(20-122) from diagnosis. Currently 10/11 patients are in complete remission,
while 1 patient, affected by follicular centre lymphoma, is alive with disease 52
months from autologous stem cell transplantation. Our study shows that both
conventional therapy and high-dose chemotherapy can be performed safely in
chronic hepatitis B and C virus carriers.
PMID- 10674905
TI - T-cell receptor gamma and delta gene rearrangements in T-cell acute lymphoblastic
leukemia in Indian patients.
AB - T-cell acute lymphoblastic leukemia (T-ALL) is a clonal lymphoid malignancy and
junctional sequences of rearranged T-cell receptor (TCR) represent the best
suitable marker to study clonality in these patients. A sensitive, non
radioactive, and rapid approach of PCR coupled with heteroduplex analysis was
used to analyse clonality of TCR gamma and delta gene rearrangements in 26 Indian
T-ALL patients. Amongst TCR gamma gene family, VgammaI-Jgamma1.3/2.3 sequences
were most utilized (53.9%) while from TCRdelta repertoire Vdelta1-Jdelta1
sequences were preferentially rearranged (23.1%) in these patients. 19.2% of
Indian T-ALL patients demonstrated both clonal TCR gamma and delta gene
rearrangements along with surface expression of TCRgammadelta. Although the
majority of T-ALL patients showed surface expression of TCRalphabeta, the small
fraction (19.2%) of TCRgammadelta+ T-ALL represent a distinct subgroup which
needs further evaluation.
PMID- 10674906
TI - Management of severe neutropenia with cyclosporin during initial treatment of
Epstein-Barr virus-related hemophagocytic lymphohistiocytosis.
AB - Severe neutropenia (absolute neutrophil count <500/gl) is probably due to the
combined effects of dysregulated cytokine production and chemotherapeutic agents,
and is one of the risk factors in the initial treatment of patients with Epstein
Barr virus-related hemophagocytic lymphohistiocytosis (EBV-HLH). We report here 9
cases of neutropenic HLH, of which 8 were treated with cyclosporin (CSA, 2-6
mg/kg/day; continuous infusion, or 6 mg/kg/day; per os, for periods ranging from
9 days to >8 weeks) in the initial neutropenic phase during induction treatment
using corticosteroids and etoposide. Five of the 6 cases, in which CSA treatment
was started early (before the second week of induction), survived the critical
period with recovery of neutrophil counts within a week. The remaining 3 cases,
in which CSA was introduced later or not at all, died of infection. Based on
these results, we recommend a prompt short-term CSA infusion during neutropenic
episodes in the most common treatment regimen of etoposide and corticosteroids in
patients with HLH. Improved neutrophil recovery as a result of CSA treatment
makes it possible to continue immunochemotherapy safely and obtain improved
patient outcomes.
PMID- 10674907
TI - The use of archival bone marrow specimens in detecting B-cell non-Hodgkin's
lymphomas using polymerase chain reaction methods.
AB - The detection of B-cell non-Hodgkin's lymphoma (B-NHL) involving the bone marrow
(BM) can be enhanced by assessing immunoglobulin heavy chain (IgH/JH) gene
rearrangement using PCR. While the fresh BM aspirate has been the most commonly
used specimen, the utility of archival BM tissues has not been extensively
evaluated. We studied the BM from 13 patients with nodal B-NHL (7 low-grade and 6
intermediate grade), which were categorized into three groups based on the
histologic finding of lymphoma (H) and the presence of a monoclonal IgH/JH band
by PCR using fresh BM aspirates (M): (1) H(+)/M(+), 4 cases; (2) H(+)/M(-), 4
cases; and (3) H(equivocal)/M(-), 5 cases. Archival tissues available for study
included paraffin-embedded trephine biopsy (TB)/aspirate clots (AC) and air-dried
aspirate smears (AS). All TB (13/13) and a subset of AC (5/13) were B5-fixed, and
all these tissues failed to yield analyzable DNA. In contrast, sufficient DNA was
consistently obtained in AC that were formalin-fixed (8/13). Of these 8 cases,
2/3 of group 1, 3/3 of group 2, and 0/2 of group 3 had a monoclonal IgH band.
Using DNA extracted from microdissected lymphoid aggregates morphologically
evident in the AC sections, additional positive cases were identified: 1/3 of
group 1 and 2/2 of group 3. In those 5 cases that did not have formalin-fixed
TB/AC, sufficient DNA was extracted from AS in all cases; one additional positive
case was identified in group 1. Overall, 4/4 (100%) of group 1, 3/4 (75%) of
group 2, and 2/5 (40%) of group 3 showed molecular evidence of lymphoma. To
conclude, archival BM specimens are a useful source of DNA for molecular
detection of B-NHL involvement, and formalin appears to be a better fixative than
B5. The use of these samples may improve the overall detection sensitivity.
PMID- 10674908
TI - CD5 is A potential selecting ligand for B-cell surface immunoglobulin: a possible
role in maintenance and selective expansion of normal and malignant B cells.
AB - Although the function of CD5 on B cells is unknown, previous studies suggested
that CD5 interaction with V(H) framework regions of surface immunoglobulins (Igs)
may contribute to survival and expansion of B cells. Here we used B-chronic
lymphocytic leukemia (B-CLL) cells and transformed B-cell lines from normal and B
CLL patients to study CD5-Ig interactions. Immobilized Ig binds and permits
isolation of CD5 from lysates of CD5-expressing cell lines. Immunoglobulins or
Fab fragments of different V(H) families varied in their effectiveness as
inhibitors of anti-CD5 staining of CLL cells, appendix and tonsil tissue
sections. Human Ig also binds to purified recombinant CD5. We show here for the
first time that the unconventional Ig-CD5 interaction maps to the extracellular
CD5-D2 domain whereas conventional epitopes recognized by anti-CD5 antibodies are
localized in the D1 domain of CD5. We propose that interactions of VH framework
regions with CD5 as a ligand may maintain, select or expand normal, autoimmune or
transformed B cells and also contribute to skewing of the normal V(H) repertoire.
PMID- 10674909
TI - Histamine as an autocrine regulator of leukemic cell proliferation.
AB - We examined leukemic lymphocyte precursors from ALL patients as well as
immortalized ALL cell lines for cytoplasmic histamine expression. The histamine
levels ranged from 10.8 pg/10(6) cells to 82.2 pg/10(6) cells in ALL cell lines
(N=4) and from 12.5 pg/10(6) cells to 1235.4 pg/10(6) cells for primary leukemic
cells from ALL patients (N=13). The presence of histamine in the cytoplasm of
these ALL cells was also confirmed by immunostaining using a polyclonal rabbit
anti-histamine antibody. Notably, the histamine receptor blocker diphenhydramine
inhibited the clonogenic growth of ALL cells by >90% prompting the hypothesis
that histamine may be an autocrine regulator of ALL cell proliferation. Our study
suggests that histamine receptor blockers may therefore be useful for the
treatment of therapy-refractory ALL.
PMID- 10674910
TI - Cell cycle-independent down-regulation of BCL-2 protein expression in
differentiating HL-60 cells.
AB - To understand the relationship between bcl-2 protein expression and the cell
cycle during the processes of differentiation, we examined bcl-2 protein levels
expressed during cell cycle phases in differentiating HL-60 human leukemia cells
by using a two-color flow cytometric method. In exponentially proliferating HL-60
cells bcl-2 protein was constitutively expressed throughout the cell cycle
phases, but a small population of G0/G1 cells expressed decreased levels of
protein as compared with other cell cycle phases. HL-60 cells can be induced to
differentiate to granulocytic pathway by retinoic acid or dimethylsulfoxide, and
to monocytic/macrophagic pathway by 1, 25 dihydroxyvitamin D3 or 12-O
tetradecanoylphorbol -13-acetate. During treatment with any of these inducing
agents, bcl-2 protein expression was time-dependently down-regulated after 24 h.
A two-color flow cytometric analysis revealed that this down-regulation occurred
throughout cell cycle phases, indicating that bcl-2 protein expression was down
regulated in cell cycle-independent manner during induction of differentiation in
HL-60 cells. To our knowledge, this is the first demonstration suggesting that
the regulation of bcl-2 protein expression is not related to the cell cycle
during induction of differentiation in HL-60 cells.
PMID- 10674911
TI - Light microscopic detection of BCR-ABL transcripts after in-cell RT-PCR: fusion
gene expression might correlate with clinical evolution of chronic myeloid
leukemia.
AB - A procedure for in-cell amplification of the hybrid BCR-ABL mRNA by reverse
transcription and polymerase chain reaction (RT-PCR) without extraction of the
nucleic acids was performed directly in fixed and permeabilized cells of leukemia
patients (22 patients with Ph'-positive chronic myeloid leukaemia-CML and 1 with
Ph'-positive acute leukaemia-AL, as well as 7 Ph'-negative cases) and Ph'
positive human leukaemia cell lines (K562, LAMA-84, BV173). The labelling of the
amplified sequences was done employing biotinylated primers and a second PCR in a
semi-nested fashion with a low number of cycles. An enzymatic system based on
biotin-streptavidin-chromogen reaction was used for the detection of labeled PCR
product, thus producing a coloured product, visible to the eye under a standard
light microscope. All samples from patients with cytogenetic and molecular
evidence of BCR-ABL rearrangement showed specific cytoplasmic staining at the
site of the amplified hybrid transcripts. It allowed definite distinction between
positive and negative cells. K562, LAMA-84, BV173 cells were characterized with
strong diffuse staining while an interesting finding of the present study was the
presence of variable quantities of colour product in patients' samples which
might be due to different mRNA expression. Early and intermediate stages of
myeloid maturation showed more intense reactivity. Cases with an aggressive
course of accelerated or blast phase CML and AL were found to have a considerable
subset of cells with strongly expressed signal while cases in chronic phase were
characterised with uniform weak to moderate reaction. Our observations support
the hypothesis that the amount of BCR-ABL transcript expression within neoplastic
cells may play a role in dictating the eventual behaviour of the leukaemic clone.
Future studies at a single cell level of larger series of consecutive cases with
a follow up might be able to identify those patients who are prone to
transformation and provide certain indications for further therapeutic decisions.
PMID- 10674912
TI - HIV infection of megakaryocytic cell lines.
AB - Thrombocytopenia is a common hematologic disorder in HIV infection and occurs in
both asymptomatic and AIDS patients. An autoimmune mechanism has been postulated
for the platelet destruction associated with some forms of thrombocytopenia.
However, recent studies revealed that megakaryocytes are susceptible to HIV
infection and suggested the possibility that HIV can directly impair the platelet
production from megakaryocytes. This study was designed to characterize the HIV
receptor expression in megakaryocytic cells and the responsiveness to HIV
infection. Four different megakaryocytic cell lines at different stages of
differentiation were established from the peripheral blood of different
individuals with hematologic malignancies. CMK and CMY cells (differentiated cell
lines) expressed CD4, but CMS and CTS cells (poorly differentiated cell lines)
did not. The HIV coreceptor CXCR4 was also expressed in CMY and CMK cells. HIV-1
(HTLV-IIIB) replicated in CMY cells persistently but not in other three cell
lines. CMY cells as well as CMK cells were also susceptible to the lytic
infection of HIV-2 (LAV2). Pretreatment of the CMY cells with anti-CD4 antibody
inhibited the infection by both HIV-1 and HIV-2. Our results indicate that mature
megakaryocytic cells express CD4 along with HIV coreceptors and are susceptible
to HIV infection.
PMID- 10674913
TI - Temporary remission of an alveolar rhabdomyosarcoma diagnosed and treated as
acute leukemia.
AB - A 29-year-old man with alveolar rhabdomyosarcoma was considered to be suffering
from acute leukemia. A bone marrow aspirate had revealed extensive infiltration
by atypical blast-like cells which were interpreted as acute lymphoblastic
leukemia. Although there was no confirmation of this diagnosis by
immunophenotyping chemotherapy with a protocol suited for the treatment of acute
lymphoblastic leukemia was started prior to histological analysis and resulted in
a complete temporary remission after the first cycle. Histological analysis of a
bone marrow biopsy revealed an alveolar rhabdomyosarcoma, as further confirmed by
molecular genetic analysis. Two months after the end of chemotherapy, there was
an extensive recurrence and the patient died one year after initial diagnosis
with chemotherapy refractory disease. In conclusion, rhabdomyosarcoma should
always be included in the differential diagnosis of systemic diseases with
extensive bone marrow infiltration by tumor cells which could otherwise be
misinterpreted as a haematological malignancy.
PMID- 10674914
TI - Epstein-Barr virus-associated high-grade anaplastic plasmacytoma in a renal
transplant patient.
AB - Allograft transplant patients have an increased risk of developing polyclonal or
monoclonal lymphoproliferative disorders, but high-grade anaplastic plasmacytomas
are extremely rare in these patients. We present a renal transplant patient who
developed multiple extramedullary high-grade anaplastic plasmacytomas in the oral
cavity, the left maxillary antrum, the scalp, the thigh and the upper abdominal
wall with no evidence of diffuse bone marrow infiltration. Epstein-Barr virus
(EBV) mRNA transcripts were detected within the myeloma cells by in situ
hybridization using EBER1-2 probes. Following discontinuation of
immunosuppression applied, the patient was treated with a cyclophosphamide
prednisone regimen followed by local irradiation, and a complete remission was
achieved within four weeks. We concluded that EBV-associated high-grade
anaplastic plasmacytomas constitute one more type of post-transplant
lymphoproliferative disorder, and that despite their characterization as highly
malignant neoplasms, their clinical behavior is not always aggressive.
PMID- 10674915
TI - Postmastectomy malignant lymphoma.
AB - Postmastectomy lymphedema (PML) is a morbid condition occurring in patients with
breast carcinoma treated with radical/modified radical mastectomy. Postmastectomy
angiosarcoma (PMA) is the most common neoplasia seen in these patients. Primary
malignant lymphoma arising in PML is a rare neoplasia and 3 cases have been
reported until now. In this report a patient with diffuse large cell lymphoma
(DLCL) arising in PML is reported and the other three cases are reviewed.
PMID- 10674916
TI - Non-Hodgkin's lymphoma following untreated essential thrombocythemia.
AB - The coexistence of essential thrombocythemia (ET) and non-Hodgkin's lymphoma
(NHL) is an extremely rare event, with only two such cases having been reported
in the medical literature. We describe here a 25-year old woman who developed
high-grade B-cell NHL of the stomach three years after the diagnosis of ET, for
which she had received no treatment, due to her young age and the lack of
thrombotic risk factors other than thrombocytosis. The lymphoma showed a
favorable response to CHOP chemotherapy, whereas the thrombocytosis remained
unchanged throughout the patient's clinical course. The possible etiologic and
pathogenetic mechanisms leading to the association of these two disorders are
discussed. Given the relative frequency of ET and the fact that the present case
represents only the third reported instance of NHL developing in such patients,
the coincidental ocurrence of both diseases is a possibility that cannot be
excluded.
PMID- 10674917
TI - Inducible types of cyclooxygenase and nitric oxide synthase in adaptive
cytoprotection in rat stomachs.
AB - Roles of cyclooxygenases (COX-1 and COX-2) and nitric oxide (NO) synthases (nNOS
and iNOS) in adaptive cytoprotection induced by 20 mM taurocholate dissolved in
50 mM HCl (TC) were investigated in rat stomachs. Intragastric administration of
0.6 N HCl caused haemorrhagic damage in the stomach. These lesions were prevented
by pretreatment of the animals with TC p.o. 0.5 h before 0.6 N HCl, and a
significant protection persisted for more than 5 h. The protection afforded by TC
given 0.5 h before HCl was almost totally reversed by indomethacin and slightly
mitigated by N(G)-nitro-L-arginine methyl ester (L-NAME) but not affected by NS
398 or aminoguanidine. By contrast, the mucosal protective action of TC given 5 h
before HCl was significantly reversed by NS-398, L-NAME and aminoguanidine as
well as indomethacin. Mucosal prostaglandin E2 (PGE2) contents were significantly
increased for over 5 h after TC, while luminal NOx output tended to elevate at
0.5 h and be significantly increased at 5 h after TC. The increased PGE2
generation observed 0.5 h after TC was attenuated only by indomethacin, while
that observed 5 h after TC was inhibited by NS-398 as well as indomethacin. On
the other hand, the NOx output determined at 5 h after TC was significantly
reduced by both L-NAME and aminoguanidine. The expression of mRNA for both COX-2
and iNOS was apparently detected in the stomach from 3 h after TC treatment.
These results suggest that TC induced adaptive cytoprotection in the rat stomach
against 0.6 N HCl, the effect lasting for over 5 h, and the underlying mechanism
differs depending on the period after the irritation. The early phase is mediated
mainly by COX-1/PGs, while the later phase is mediated by iNOS/NO, in addition to
prostaglandins (PGs) produced by both COX-1 and COX-2.
PMID- 10674918
TI - The role of the host versus the environment in duodenal ulcer disease.
AB - Gastric functions can be understood only in the context of a network including
the brain gut axis, neuro-endocrine and paracrine mechanisms and growth factors.
These host factors including parietal cell sensitivity (PCS) may well interact
with an important environmental factor, Helicobacter pylori (Hp), and help to
explain its actions. The aim of this study was to investigate PCS related to Hp
status and duodenal ulcer (DU). PCS was assessed by constructing dose-response
curves after pentagastrin and calculating the D50. Five groups of patients were
studied: I) active DU, Hp pos. (8); II) history of DU, Hp pos. (8); III)
asymptomatic Hp pos. (8); IV) asymptomatic Hp neg. (10); V) DU on maintenance H2
blocker therapy, Hp pos. (20). PCS was repeated after Hp eradication. PCS was
lowest in group IV, and in Hp pos. groups, was significantly higher, with
insignificant differences among them, irrespective of DU. PCS declined
significantly after Hp eradication. Group V showed an insignificant decline in
PCS during treatment, not preventing recurrence. A higher PCS in Hp infection
irrespective of DU, declining after eradication, suggests that this may be a
reversible epiphenomena related to Hp infection. This may offer an explanation as
to why DU develops only in some subjects with Hp, suggesting the importance of
the host in the pathogenesis of DU.
PMID- 10674919
TI - Cytoprotection and intracellular calcium.
AB - It seems that prostacyclin has an increasing effect on gastric mucosal (antral
and fundic) calmodulin level in rats. Using either the calcium channel blocker
verapamil or anti-calmodulin drugs (diazepam, trifluoperazine,) the
cytoprotective effect of prostacyclin can be inhibited. Therefore, it is probable
that calcium ions and calcium-activated calmodulin play a role in the effect of
prostacyclin.
PMID- 10674920
TI - Roles of endogenous prostaglandins and nitric oxide in gastroduodenal ulcerogenic
responses induced in rats by hypothermic stress.
AB - We examined the roles of endogenous prostaglandins (PGs) and nitric oxide (NO) in
the gastroduodenal ulcerogenic responses to hypothermic stress (28 approximately
30 degrees C) in anesthetized rats. Lowering body temperature provoked damage in
the gastroduodenal mucosa, with an increase of gastric acid secretion and
motility. These responses were completely abolished by bilateral vagotomy or
atropine, while 16,16-dimethyl PGE2 decreased the mucosal ulcerogenic response
with no effect on acid secretion. The non-selective COX inhibitors, indomethacin
or aspirin, worsened these lesions with enhancement of gastric motility and no
effect on acid secretion, while the selective COX-2 inhibitor NS-398 did not
affect any of these responses. On the other hand, the non-selective NOS inhibitor
L-NAME but not aminoguanidine (a relatively selective inhibitor of iNOS),
significantly potentiated the acid secretory and mucosal ulcerogenic responses in
the stomach but reduced the duodenal damage in response to hypothermia, the
effects being antagonized by co-administration of L-arginine. Hypothermia itself
decreased duodenal HCO3- secretion under both basal and mucosal acidification
stimulated conditions. Both indomethacin and aspirin further decreased the HCO3-
response to the mucosal acidification, while L-NAME significantly increased the
HCO3- secretion even under hypothermic conditions, similar to 16,16-dimethyl
PGE2. These results suggest that 1) hypothermic stress caused an increase of acid
secretion and motility as well as a decrease of duodenal HCO3-secretion,
resulting in damage in both the stomach and duodenum, 2) the COX-1 but not COX-2
inhibition worsened these lesions by enhancing gastric motility and further
decreasing duodenal HCO3- response, 3) the cNOS but not iNOS inhibition worsened
gastric lesions by increasing acid secretion but decreased duodenal damage by
increasing HCO3- secretion. Thus, it is assumed that the gastroduodenal
ulcerogenic and functional responses to hypothermic stress are modified by
cNOS/NO as well as COX-1/PGs.
PMID- 10674921
TI - Small doses of capsaicin given intragastrically inhibit gastric basal acid
secretion in healthy human subjects.
AB - Although the direct inhibitory effect of small dose of capsaicin on gastric
secretory responses was proved in animal observations, the role of capsaicin
sensitive afferent nerves (CSAN) and the effect of capsaicin applied in small and
high doses on gastric secretion in human has not been clarified yet. In this
study we investigated the influence of different small doses (100-800 microg) of
capsaicin given intragastrically through an orogastric tube on gastric basal
secretory responses in 10 healthy human subjects. Gastric basal secretory
responses (volume, H+-concentration, H+-output) were measured from the suctions
of gastric juice for a 1-h period. It has been found that: a) capsaicin dose
dependently inhibited the volume and H+-output of gastric juice; b) ID50 was
found to be about 400 microg for capsaicin on gastric acid secretion; c) the time
interval for capsaicin-induced gastric inhibition existed for about 1 h
indifferently from the higher dose (800 microg) of capsaicin given after. It has
been concluded that the capsaicin (given in small doses) inhibits the gastric
basal acid output via stimulation of the inhibition of capsaicin sensitive
afferent nerves.
PMID- 10674922
TI - A novel method to produce extensive gastric antral ulcer in rats: pharmacological
factors involved in the etiology of antral ulceration.
AB - Gastric antral area is the most susceptible region to gastric ulceration in man.
However, only limited information is available on animal models. In the present
paper, we have developed an improved method for inducing gastric antral ulcers by
the administration of 1.0 M HCl after refeeding for 1 h in rats. On day 4, the
severe ulcer was found covering extensively the whole area of the antrum, and
penetrated through the muscularis mucosae. The incidence of ulceration was 100%
and the mean ulcer index was 37.1 +/- 16.6 mm2. In contrast, none of the erosive
lesions were observed in the corpus area. Before 24 h, only slight hyperemia was
observed in the antral region, suggesting that some submucosal mechanisms are
involved in the ulceration processes other than the direct erosive action of HCl
on the mucosal surface. Additional treatment with diethyldithiocarbamate (125 mg
x kg(-1), s.c.), superoxide dismutase inhibitor, significantly aggravated this
antral ulcer, and the ulcer index was 66.0 +/- 13.6 mm2. Allopurinol (50 mg x kg(
1), p.o.) significantly prevented ulcer formation induced by HCl plus DDC. GSH
(150 mg x kg(-1), i.p.) also markedly prevented the ulceration. However, DMSO
(0.5%, 5 mL x kg(-1), p.o.) was found not to affect ulcer formation. Famotidine
(20 mg x kg(-1), p.o.) almost completely inhibited ulcer formation. From the
above results, it was concluded that gastric antral ulcer can be induced by the
simple treatment of 1.0 M HCl in refed rats, and the antrum has a different
defensive mechanism from that in the corpus area. In addition. oxygen derived
radicals, especially superoxide anion and endogenous acid secretion were found to
be involved in the etiology of the aggravation of the gastric antral ulcer
induced by DDC.
PMID- 10674923
TI - Capsaicin-sensitive afferent sensory nerves in modulating gastric mucosal defense
against noxious agents.
AB - In the rat stomach, evidence has been provided that capsaicin-sensitive sensory
nerves (CSSN) are involved in a local defense mechanism against gastric ulcer. In
the present study capsaicin or resiniferatoxin (RTX), a more potent capsaicin
analogue, was used to elucidate the role of these sensory nerves in gastric
mucosal protection, mucosal permeability, gastric acid secretion and
gastrointestinal blood flow in the rat. In the rat stomach and jejunum,
intravenous RTX or topical capsaicin or RTX effected a pronounced and long
lasting enhancement of the microcirculation at these sites, measured by laser
Doppler flowmetry technique. Introduction of capsaicin into the rat stomach in
very low concentrations of ng-microg x mL(-1) range protected the gastric mucosa
against damage produced by topical acidified aspirin, indomethacin, ethanol or
0.6 N HCl. Resiniferatoxin exhibited acute gastroprotective effect similar to
that of capsaicin and exerted marked protective action on the exogenous HCl, or
the secretagogue-induced enhancement of the indomethacin injury. The ulcer
preventive effect of both agents was not prevented by atropine or cimetidine
treatment. Capsaicin given into the stomach in higher desensitizing
concentrations of 6.5 mM markedly enhanced the susceptibility of the gastric
mucosa and invariably aggravated gastric mucosal damage evoked by later noxious
challenge. Such high desensitizing concentrations of capsaicin, however, did not
reduce the cytoprotective effect of prostacyclin (PGI2) or beta-carotene.
Capsaicin or RTX had an additive protective effect to that of atropine or
cimetidine. In rats pretreated with cysteamine to deplete tissue somatostatin,
capsaicin protected against the indomethacin-induced mucosal injury. Gastric acid
secretion of the pylorus-ligated rats was inhibited with capsaicin or RTX given
in low non-desensitizing concentrations, with the inhibition being most marked in
the first hour following pylorus-ligation. Low intragastric concentrations of RTX
reduced gastric hydrogen ion back-diffusion evoked by topical acidified
salicylates. It is concluded that the gastropotective effect of capsaicin-type
agents involves primarily an enhancement of the microcirculation effected through
local release of mediator peptides from the sensory nerve terminals. A reduction
in gastric acidity may contribute to some degree in the gastric protective action
of capsaicin-type agents. The vasodilator and gastroprotective effects of
capsaicin-type agents do not depend on vagal efferents or sympathetic neurons,
involve prostanoids, histaminergic or cholinergic pathways.
PMID- 10674924
TI - Capsaicin increases gastric emptying rate in healthy human subjects measured by
13C-labeled octanoic acid breath test.
AB - The role of capsaicin-sensitive primary afferent sensory nerves in the regulation
of gastrointestinal motility in human is not clarified yet. In this study, we
investigated the effect of 400 microg capsaicin given intragastrically on gastric
emptying measured by 13C-octanoic acid breath test in ten healthy human subjects.
Four parameters of gastric emptying curves were taken into consideration: 1)
maximum value of the curve, 2) time belonging to this maximum, 3) slope of the
rising part of the curve and 4) time belonging to the 50% of the area under the
curve. Administration of 400 microg capsaicin significantly increased the slope
of gastric emptying curve (from 0.1 +/- 0.01 to 0.139 +/- 0.014 U x min(-1), P <
0.05) and significantly decreased the time belonging to the maximum value of
emptying curve (from 150 +/- 18 to 75 +/- 12 min, P < 0.05) and the time
belonging to the 50% of the area under the curve (from 112 +/- 15 to 99 +/- 14
min, P < 0.05). According to our results 400 microg capsaicin enhances gastric
emptying rate in healthy human subjects.
PMID- 10674925
TI - Capsaicin inhibits the pentagastrin-stimulated gastric acid secretion in
anaesthetized rats with acute gastric fistula.
AB - The effect of capsaicin on basal and pentagastrin-stimulated gastric acid
secretion was investigated in the urethane anaesthetized acute gastric fistula
rat. Gastric acid secretion was measured by flushing of the gastric lumen with
saline every 15 min or by continuous gastric perfusion. Capsaicin given into the
rat stomach at 120 ng x mL(-1) prior to pentagastrin (25 microg x kg(-1), iv)
reduced gastric acid secretory response to pentagastrin by 24%. Intravenous (iv)
capsaicin (0.5 microg x kg(-1)) did not reduce the pentagastrin-stimulated
gastric acid secretion. After topical capsaicin desensitization (3 mg x mL(-1)),
basal gastric acid secretion and that in response to pentagastrin (25 microg x
kg(-1), intraperitonaeally) was unaltered compared with the control group. Data
indicate that topical capsaicin inhibits gastric acid secretion stimulated with
pentagastrin in anaesthetized rats.
PMID- 10674926
TI - Influence of column design on process-scale ion-exchange chromatography.
AB - The performance of two new designs of pump-packed axial flow process
chromatography columns have been evaluated for the preparative anion-exchange
chromatography of hen egg-white proteins using Whatman Express-Ion Exchanger Q. A
16 1 Side-Pack column and a 24 1 IsoPak column containing Express-Ion Q were used
in this study. In each case ca. 20 1 feedstock containing 5-7 g protein/l, was
applied per litre packed bed at flow-rates of ca. 150 and 300 cm/h. In each case
the ovalbumin binding capacity was ca. 70 g/l packed bed with ca. 100% (w/w)
recovery of applied protein. A clean-in-place procedure involving storage in 0.5
M NaOH was effective in maintaining chromatographic performance in all cases.
These data were consistent with our previous work using the more traditionally
configured slurry-packed axial flow columns. Each of these column designs were
easy to use facilitating rapid packing with this adsorbent and in the case of
IsoPak rapid pump unpacking. The introduction of these column designs
significantly improves the task of column packing, hitherto a labour intensive,
physically demanding and potentially unreproducible process.
PMID- 10674927
TI - Modeling and simulation of the dynamic behavior of monoliths. Effects of pore
structure from pore network model analysis and comparison with columns packed
with porous spherical particles.
AB - A mathematical model is presented that could be used to describe the dynamic
behavior, scale-up, and design of monoliths involving the adsorption of a solute
of interest. The value of the pore diffusivity of the solute in the pores of the
skeletons of the monolith is determined in an a priori manner by employing the
pore network modeling theory of Meyers and Liapis [J. Chromatogr. A, 827 (1998)
197 and 852 (1999) 3]. The results clearly show that the pore diffusion
coefficient, Dmp, of the solute depends on both the pore size distribution and
the pore connectivity, nT, of the pores in the skeletons. It is shown that, for a
given type of monolith, the film mass transfer coefficient, Kf, of the solute in
the monolith could be determined from experiments based on Eq. (3) which was
derived by Liapis [Math. Modelling Sci. Comput., 1 (1993) 397] from the
fundamental physics. The mathematical model presented in this work is numerically
solved in order to study the dynamic behavior of the adsorption of bovine serum
albumin (BSA) in a monolith having skeletons of radius r(o) = 0.75x10(-6) m and
through-pores having diameters of 1.5x10(-6)-1.8x10(-6) m [H. Minakuchi et al.,
J. Chromatogr. A, 762 (1997) 135]. The breakthrough curves of the BSA obtained
from the monolith were steeper than those from columns packed with porous
spherical particles whose radii ranged from 2.50x10(-6) m to 15.00x10(-6) m.
Furthermore, and most importantly, the dynamic adsorptive capacity of the
monolith was always greater than that of the packed beds for all values of the
superficial fluid velocity, Vtp. The results of this work indicate that since in
monoliths the size of through-pores could be controlled independently from the
size of the skeletons, then if one could construct monolith structures having (a)
relatively large through-pores with high through-pore connectivity that can
provide high flow-rates at low pressure drops and (b) small-sized skeletons with
mesopores having an appropriate pore size distribution (mesopores having
diameters that are relatively large when compared with the diameter of the
diffusing solute) and high pore connectivity, nT, the following positive results,
which are necessary for obtaining efficient separations, could be realized: (i)
the value of the pore diffusion coefficient, Dmp, of the solute would be large,
(ii) the diffusion path length in the skeletons would be short, (iii) the
diffusion velocity, vD, would be high, and (iv) the diffusional response time,
t(drt), would be small. Monoliths with such pore structures could provide more
efficient separations with respect to (a) dynamic adsorptive capacity and (b)
required pressure drop for a given flow-rate, than columns packed with porous
particles.
PMID- 10674928
TI - Polycations as displacer in high-performance bioseparation.
AB - Displacement chromatography is an interesting but up to now rarely used type of
preparative biochromatography. The lack of well-engineered and accessible
displacer contributes to this phenomenon. In this paper a novel type of displacer
is introduced for cation-exchange displacement chromatography, which will soon
become commercially available. The molecule is a well-defined PolyDADMAC
[poly(diallyldimethylammonium chloride)] with a molar mass of less than 35000
g/mol, an exclusively linear structure and a molar mass polydispersity of less
than 1.5. A method for synthesizing such a polymer at high yields is described.
The PolyDADMAC is shown to be an efficient displacer of basic proteins from
strong cation-exchange columns.
PMID- 10674929
TI - Development of an high-performance liquid chromatographic simulated moving bed
separation from an industrial perspective.
AB - A binary test mixture consisting of cyclopentanone and cycloheptanone is used for
the performance evaluation of a pilot-scale simulated moving bed unit. The
involved adsorption equilibria and the kinetic behavior are discussed in detail.
The results of the test runs are evaluated using the recently introduced
"triangle theory" which allows to account for the overload conditions prevailing
under preparative chromatographic conditions and to select optimal operating
conditions. Under optimized conditions the separation of 735 g test mixture/kg
stationary phase per day with purities >99.9% for extract and raffinate stream
has been achieved.
PMID- 10674930
TI - Quantification of single solute and competitive adsorption isotherms using a
closed-loop perturbation method.
AB - A modification of the classical method of perturbation chromatography for
measuring isotherms of the adsorption of dissolved components is suggested. The
general principle of the method consists in analyzing responses of the
chromatographic system to small perturbations at different equilibrium
concentrations. Essential advantages of the method are: (a) only retention times
or volumes have to be measured and no detector calibration is required and (b)
experiments with mixtures can be performed and analyzed efficiently. The
modification suggested in this paper is the application of a closed-loop
arrangement allowing the efficient exploitation of the sample. Experimental data
for four different chromatographic systems are presented to illustrate the
method. With the determined adsorption isotherms elution profiles could be
predicted satisfactorily.
PMID- 10674931
TI - Visualization of viscous fingering in high-performance liquid chromatographic
columns. Influence of the header design.
AB - Using an on-column visualization technique, band profiles of solutes migrating
along an HPLC column were studied. The study showed that, under conditions where
viscous fingering is prevalent, the design of the inlet header has little
influence on the outcome of the viscous fingers. Two types of headers were
studied. The first contained a small diameter inlet frit, which localized the
majority of the sample in or near the central region of the column. The second
header contained a wide frit and produced a more uniform radial distribution of
the sample. In both cases, the extent of viscous fingering was essentially the
same.
PMID- 10674932
TI - Visualization of sample introduction in liquid chromatographic columns.
Contribution of a flow distributor on the sample band shape.
AB - The contributions to the radial distribution of the sample concentration across
the column inlet and to the axial band dispersion resulting from a column header
containing a distributor were evaluated using a band-visualization process
entailing matching the refractive indices of the stationary and mobile phases in
a glass column. This study illustrates graphically how a distributor fitted to
the column can increase the axial dispersion of the sample band compared to an
inlet containing only a frit. The distributor did not provide a uniform sample
distribution across the column. In fact, for 17-mm inner diameter columns and
high-porosity frits, the distribution was no better than with the frit having no
distributor. However, when low-porosity frits were employed, improved peak shapes
were obtained with a distributor. In addition, we observed that the inlet header
configuration influenced dramatically the flow stream established along the
column. The radial distribution of the efficiency of the columns was nearly
homogeneous for those having only a frit but not for those having also a
distributor. For the latter, the efficiency decreased from the column axis to its
wall.
PMID- 10674933
TI - Determination of the thermodynamic contribution to peak asymmetry of basic
solutes in reversed-phase liquid chromatography.
AB - To this day packing materials manufacturers are still trying to develop reversed
phase stationary phases that have silica more completely reacted with bonding
ligands to afford more homogeneous particle surfaces. Incomplete bonding causes
inhomogeneous effects that are readily observed when separating basic solutes
because of the acidic silanols that are unreacted. However, it is still not
understood exactly what types of silanol sites are unreacted or if metal
impurities are contributing to the resulting peak asymmetry observed. A method is
presented which utilizes (1) the frontal analysis method of chromatography to
obtain adsorption/partition isotherms, (2) a heterogeneous Langmuir distribution
model for the resulting isotherm, (3) an expectation-maximization numerical
procedure to solve the mathematical problem to yield the most probable
distribution of adsorption parameters, and (4) the equilibrium-dispersive model
of chromatography incorporating the fitted isotherm model to check the validity
of the sorption model with experimental observations. Correlation of packing
materials characterization parameters with results obtained by this procedure
will indicate what type of silanols or other sites are responsible for observed
tailing behavior. Developers and manufacturers will then be able to more
efficiently target their synthetic designs for "base-deactivated" reversed-phase
silicas.
PMID- 10674934
TI - Study of hydrophobic interaction adsorption of bovine serum albumin under
overloaded conditions using flow microcalorimetry.
AB - The adsorption behavior of bovine serum albumin (BSA) on a Sepharose based
hydrophobic interaction support has been studied. Flow microcalorimetry has been
used to determine the heat of adsorption under overloaded chromatographic
conditions. These data have been complemented with capacity factor and isotherm
measurements to provide insight on the mechanisms of adsorption. The heat of
adsorption data have confirmed that the hydrophobic interaction adsorption of BSA
under linear isotherm conditions is driven by entropy changes. Under overloaded
(non-linear) conditions, however, it has been shown that the changes in enthalpy
can drive adsorption; this behavior is not evident from analyses of capacity
factor data. It is postulated that for BSA adsorption on the Sepharose derivative
of interest, attractive force interactions between adsorbed protein molecules
drive the adsorption process under overloaded conditions in a high (NH4)2SO4
environment. It is further postulated that these interactions are due to a change
in confirmation of the adsorbed protein under these conditions.
PMID- 10674935
TI - Studies on the chromatographic fractionation of Trichoderma reesei cellulases by
hydrophobic interaction.
AB - This work reports new studies on cellulases fractionation by hydrophobic
interaction chromatography. The purification procedure for the Trichoderma reesei
cellulase complex consists of gel permeation chromatography on Sephadex G-25M
followed by an ultrafiltration step. The concentrated enzyme solution was then
fractionated on Sepharose CL-6B modified by covalent immobilization of 1,4
butanediol diglycidyl ether. The influence of the mobile phase composition on the
chromatographic behaviour of the T. reesei cellulase complex was investigated. By
using 13% (w/v) ammonium sulphate in eluent buffer, a selective separation of
beta-glucosidase with a two-fold increase in specific activity and a recovery of
60% cellobiase activity were obtained. Other commercial hydrophobic supports
(octyl- and phenyl-Sepharose) were also tested and compared under the same
conditions.
PMID- 10674936
TI - Expanded-bed chromatography in primary protein purification.
AB - Chromatography in stable expanded beds enables proteins to be recovered directly
from cultivations of microorganisms or cells and preparations of disrupted cells,
without the need for prior removal of suspended solids. The general performance
of an expanded bed is comparable to a packed bed owing to reduced mixing of the
adsorbent particles in the column. However, optimal operating conditions are more
restricted than in a packed bed due to the dependence of bed expansion on the
size and density of the adsorbent particles as well as the viscosity and density
of the feedstock. The feedstock composition may become the most limiting
restriction owing to interactions of adsorbent particles with cell surfaces, DNA
and other substances, leading to their aggregation and consequently to bed
instabilities and channeling. Despite these difficulties, expanded-bed
chromatography has found widespread applications in the large scale purification
of proteins from mammalian cell and microbial feedstocks in industrial
bioprocessing. The basics and implementation of expanded-bed chromatography, its
advantages as well as problems encountered in the use of this technique for the
direct extraction of proteins from unclarified feedstocks are addressed.
PMID- 10674937
TI - Electrophoretic transfer of proteins across polyacrylamide membranes.
AB - The electrophoretic transfer of purified proteins has been examined in a
Gradiflow "Babyflow BF100" unit. A number of factors affect protein separation
within this preparative electrophoresis system. We established that the rate of
protein transfer was proportional to the applied voltage. The transfer is slowest
at the isoelectric point (pI) and increased the further away the pH was from the
pI of the protein. Protein transfer was found to be independent of the ionic
strength of the buffer, for buffers that excluded the addition of strong acids or
strong bases or sodium chloride. Transfer decreased as the pore size of the
membrane decreased. Finally, transfer was inhibited at high salt concentrations
in the protein solution, but remained unaffected when urea and non-ionic
detergents were added to the solution. To increase the speed of protein
separations, buffers with low conductivity should be used. A pH for the optimal
separation should be selected on the basis of the relative pI and size of the
target proteins and that of the major contaminants.
PMID- 10674938
TI - Protein diffusion in charged polyacrylamide gels. Visualization and analysis.
AB - Protein diffusion in anionic, cross-linked polyacrylamide-based gels supported in
fused-silica capillaries was characterized by a direct visualization method.
Microphotography was used to obtain transient protein concentration profiles in
these gels using cytochrome c as a probe molecule. Gels based on acrylamido
methylpropane sulfonic acid with 2.5-10% N,N'-methylene-bisacrylamide as a cross
linker and with a total polymer concentration of 0.21 g/cm3 yielded diffuse
protein concentration profiles which were quantitatively consistent with a
Fickian diffusion model. An analytical method was developed to calculate the
diffusivity as a function of protein concentration in the gel from the
experimental profiles. The diffusivity was found to assume values in the range
2.5-5.5x10(-8) cm2/s and varied somewhat with the protein concentration in the
gel. The effects of some of the polymer properties, such as cross-link density,
polymer concentration and charge, were also investigated for a limited range of
conditions to derive qualitative trends. Results showed that the transport rates
increased with a decrease in the cross-link density, were extremely reduced when
the polymer concentration was doubled, and were slightly increased when the
charge density was decreased by half by polymerizing a 1:1 mixture of acrylamide
and acrylamido-methylpropane sulfonic acid monomers.
PMID- 10674939
TI - Rapid reversed-phase separation of proteins and peptides using optimized
'moulded' monolithic poly(styrene-co-divinylbenzene) columns.
AB - Monolithic macroporous poly(styrene-co-divinylbenzene) stationary phases have
been prepared by free radical polymerization within the confines of 4.6-mm I.D.
chromatographic columns. The optimized porous properties allow the mobile phase
to flow through these columns at flow-rates of up to 10 ml/min. As opposed to the
simultaneously tested columns packed with either silica or synthetic polymer
beads, the monoliths exhibit only modest back pressure. The monolithic columns
were able to separate mixtures of peptides and proteins in a very short time.
Under the optimized conditions, the separation of five proteins can be easily
achieved in less than 20 s.
PMID- 10674940
TI - Separation of stereoisomers in a simulated moving bed-supercritical fluid
chromatography plant.
AB - The combination of two techniques, simulated moving bed (SMB) and supercritical
fluid chromatography (SFC), leads to an apparatus with unique features. Besides
the known advantages of the SMB process, like reduced solvent consumption and its
continuity, the use of supercritical carbon dioxide as the mobile phase offers an
easy product recovery by depressurizing the supercritical fluid. Details of a SMB
SFC plant are presented for the first time. Due to the large number of process
parameters a simulation of the SMB process is necessary to achieve optimal
operating conditions. The most important thermodynamic information for a SMB
process is the adsorption isotherms. Therefore, isotherms for two phytol isomers
are measured and correlated. A fast dynamic model for the simulation of SMB is
used to calculate the region of complete separation taking different column
configurations and the compressibility of the mobile phase into account.
PMID- 10674941
TI - Enantiomers separation by simulated moving bed chromatography. Non-instantaneous
equilibrium at the solid-fluid interface.
AB - The simulated moving bed (SMB) technology, first conceived for large bulk-scale
separations in the petrochemical industry, has found increasingly new
applications in the pharmaceutical industry. Among these, the separation of fine
chemicals has been the subject of considerable study and research. This work
presents the modeling, simulation and design of the operation of a SMB plant in
order to separate a binary chiral mixture. The usual assumption of instantaneous
equilibrium at the solid-fluid interface is questioned and a first-order kinetics
of adsorption is taken into account. The cases of linear, Langmuir and modified
Langmuir equilibria are studied. The equivalent true moving bed (TMB) model was
used assuming axial dispersion for the fluid flow and plug flow for the solid
phase flow. Intraparticle diffusion was described by a linear driving force (LDF)
approximation. Simulation results indicate that, under certain conditions,
equilibrium is not actually reached at the adsorbent surface. This leads to
different unit performances, in terms of product purities and recoveries, as
compared to those predicted assuming instantaneous equilibrium. Moreover, SMB
units may be improperly designed by the usual methods (flow-rate ratio separation
regions) if non-equilibrium effects are overlooked.
PMID- 10674942
TI - Enantiomer separation of alpha-ionone using gas chromatography with cyclodextrin
derivatives as chiral stationary phases.
AB - The gas chromatographic enantiomer separation of alpha-ionone was studied with
three different chiral stationary phases using as chiral selectors: (1)
heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin, dissolved in polysiloxane PS-086,
(2) octakis(2,6-di-O-pentyl-3-O-trifluoroacetyl)-gamma-cyclodextrin and (3)
octakis(2,6-di-O-pentyl-3-O-butanoyl)-gamma-cyclodextrin, both dissolved in
polysiloxane SE-54. The influence of the concentration of the chiral selector in
the polysiloxane, coated on Chromosorb P AW-DMCS 80-100 mesh, is described and
discussed, as well as the effect of Chromosorb loading. The feasibility of the
preparative gas chromatographic separation of the enantiomers of alpha-ionone is
considered; in order to provide a term of comparison, the estimated performances
are compared with those achieved in the separation of the enantiomers of the
inhalation anaesthetic enflurane.
PMID- 10674943
TI - Preparative chromatographic resolution of enantiomers using polar organic
solvents with polysaccharide chiral stationary phases.
AB - The preparative chromatographic resolution of racemic mixtures is rapidly
becoming a standard approach for the generation of enantiomers in pharmaceutical
research and development. This paper will discuss the optical resolution of
numerous pharmaceutical intermediates and final products using polar organic
solvents with polysaccharide chiral stationary phases. The advantages of this
approach compared to more traditional mobile phases for preparative separations
will be presented. In addition the ability to reverse elution order using polar
organic solvents will be presented.
PMID- 10674944
TI - Direct, preparative enantioselective chromatography of propranolol hydrochloride
and thioridazine hydrochloride using carbon dioxide-based mobile phases.
AB - In this paper, we describe the direct, preparative enantioselective
chromatography of racemic (rac)-propranolol hydrochloride (HCI) and rac
thioridazine.HCl using Chiralpak AD chiral stationary phase and mobile phase
systems containing carbon dioxide and methanol without the use of basic or acidic
additives. Isolated fractions of propranolol.HCl were positively identified by
mass spectrometry, Beilstein flame test, melting point, and chemical analysis to
be HCI enantiomers of propranolol-HCl salts exhibited characteristic mass spectra
peaks at 36 and 38 mass-to-charge ratio in the expected 3:1 isotopic ratio for
the solute that were absent in the mass spectra for the free-base forms. To our
knowledge, the direct, preparative enantioselective isolation of HCI enantiomeric
salts of rac-propranolol and of rac-thioridazine have not been previously
demonstrated and published.
PMID- 10674945
TI - Epidemiological research in mental disorders: lessons for the next decade of
research--the NAPE Lecture 1999. Nordic Association for Psychiatric Epidemiology.
AB - OBJECTIVE: To provide an overview of the progress in the field of epidemiology of
mental disorders during the last decade, and to discuss challenges for the
future. METHOD: Following a review of the achievements of psychiatric
epidemiology, current shortcomings in the research and publications in the field
are discussed. Suggestions for changes in research and solutions to current
deficits are proposed. RESULTS: Future research needs to cover a broader spectrum
of psychopathology, including inquiries into sub-threshold characterizations;
explore etiopathogenic processes and pathways including genetic, neuroscientific
and psychological factors for the onset and persistence of psychopathology; and
provide a better assessment of help-seeking behaviors and service utilization.
CONCLUSION: Future epidemiological research should strengthen the emerging
collaborative links with the neurosciences, clinical research and public health
by acknowledging the full range of available epidemiological designs and methods,
beyond the current emphasis on large-scale, cross-sectional general population
studies.
PMID- 10674946
TI - PET measurements of brain glucose metabolism and blood flow in major depressive
disorder: a critical review.
AB - OBJECTIVE: To show that PET investigations of brain function in patients with
major depression can contribute with valuable pathophysiological knowledge about
brain function of these states. METHODS: PET studies of cerebral blood flow or
glucose metabolism in patients with unipolar or bipolar depression were reviewed.
RESULTS: The studies have great discrepancies related to sample size, subject
selection, imaging protocol and image analysis. In spite of this shortcoming,
there is evidence that patients with major depression have reduced blood flow and
metabolism in the prefrontal cortex, particularly when they exhibit psychomotor
retardation. Abnormalities are also found in the anterior cingulate gyrus and the
basal ganglia. A few studies point to the possibility that response to
antidepressant treatment can be predicted from PET scans. CONCLUSION: This
evidence is consistent with the hypothesis that depressive symptoms are caused by
dysfunction of regions of the limbic system and the frontal lobes in close
connection with the basal ganglia.
PMID- 10674947
TI - Subtyping depression by clinical features: the Australasian database.
AB - OBJECTIVE: To distinguish psychotic, melancholic and a residual non-melancholic
class on the basis of clinical features alone. Previous studies at our Mood
Disorders Unit (MDU) favour a hierarchical model, with the classes able to be
distinguished by two specific clinical features, but any such intramural study
risks rater bias and requires external replication. METHOD: This replication
study involved 27 Australasian psychiatrist raters, thus extending the sample and
raters beyond the MDU facility. They collected clinical feature data using a
standardized assessment with precoded rating options. A psychotic depression (PD)
class was derived by respecting DSM-IV decision rules while a cluster analysis
distinguished melancholic (MEL) and non-melancholic classes. RESULTS: The MELs
were distinguished virtually entirely by the presence of significant psychomotor
disturbance (PMD), as rated by the observationally based CORE measure, with over
representation on only three of an extensive set of 'endogeneity symptoms'.
CONCLUSION: In comparison to PMD, endogeneity symptoms appear to be poor
indicators of 'melancholic' type, confounding typology with severity. Results
again support the hierarchical model.
PMID- 10674948
TI - Generalized anxiety disorder (ICD-10) in primary care from a cross-cultural
perspective: a valid diagnostic entity?
AB - OBJECTIVE: Generalized anxiety disorder (GAD) is a common psychiatric disorder.
The nosological status of this diagnostic entity was critically discussed because
of the very high rate of comorbidity with other psychiatric disorders, the
assumed low degree of social disability associated with GAD in the absence of
other disorders, and an ambigious definition. METHOD: We explored the frequency
and associated social disability of GAD, and examined whether the ICD-10
definition of GAD is appropriate. The analysis was based on the WHO study on
'Psychological Problems in Primary Care' conducted in a standardized manner in 14
countries. RESULTS: We found GAD (total and without another psychiatric disorder)
to be common in primary care in nearly all countries (mean 1-month prevalence
rate, 7.9%), with about 25% of these cases presenting with GAD in the absence of
any comorbid psychiatric disorder. GAD in general, as well as non-comorbid GAD,
are associated with social disability which is as severe as that in chronic
somatic diseases. CONCLUSION: It remains questionable whether the current ICD-10
diagnosis of GAD defining 6 months as a minimum duration and requiring at least
four associated symptoms for diagnosis is the most appropriate option. Using this
definition, a substantial proportion of psychosocially disabled subjects
characterized by anxiety, tension and worrying remain undetected, and are
possibly therefore not adequately treated.
PMID- 10674949
TI - Comorbidity of the anxiety disorders in a community-based older population in The
Netherlands.
AB - OBJECTIVE: The aim of the study was to investigate patterns of comorbidity among
the anxiety disorders in a community-based older population, and the relationship
of these disorders with major depression, use of alcohol and benzodiazepines,
cognitive impairment and chronic somatic illnesses. METHOD: The data were derived
from the Longitudinal Aging Study Amsterdam (LASA) study. A two-stage screening
design was adopted to identify respondents with anxiety disorders. RESULTS: In
total, 10% of the elderly with an anxiety diagnosis suffered from two or more
anxiety disorders. Major depression (13% vs. 3%), benzodiazepine use (24% vs.
11%) and chronic somatic diseases (12% vs. 7%) were significantly more prevalent
in respondents with an anxiety disorder than in respondents without anxiety
disorders. Heavy or excessive alcohol intake (5% vs. 4%) and cognitive impairment
(11% vs. 13%) were not significantly associated with any anxiety disorder.
CONCLUSION: When anxiety disorders are diagnosed, in older people there is a
relatively high probability of comorbid conditions being present.
PMID- 10674950
TI - Traumatic events and post-traumatic stress disorder in the community: prevalence,
risk factors and comorbidity.
AB - OBJECTIVE: Lifetime and 12-month prevalence of traumatic events and DSM-IV post
traumatic stress disorder as well as risk factors and comorbidity patterns were
investigated in a representative community sample (n = 3021, aged 14-24 years).
METHOD: Traumatic events and PTSD were assessed with the Munich Composite
International Diagnostic Interview (CIDI). RESULTS: Although 26% of male subjects
and 17.7% of female subjects reported at least one traumatic event, only a few
qualified for a full PTSD diagnosis (1% of males and 2.2% of females). Traumatic
events and PTSD were strongly associated with all other mental disorders
examined. PTSD occurred as both a primary and a secondary disorder. CONCLUSION:
The prevalence of PTSD in this young German sample is considerably lower than
reported in previous US studies. However, the conditional probability for PTSD
after experiencing traumas, risk factors and comorbidity patterns are quite
similar. Traumatic events and full PTSD may increase the risk for other
disorders, and vice versa.
PMID- 10674951
TI - A transcultural outcome study of adolescent eating disorders.
AB - OBJECTIVE: The aim of the study was to assess the treatment and outcome of
adolescent eating disorders in an international study including Western and
Eastern European clinical and research centres. METHOD: A total of 138 patients
with adolescent onset of an eating disorder (primarily anorexia nervosa) were
followed-up after a mean interval of 5 years after first admission. RESULTS: On
average, the patients had spent 25% of the total follow-up period in either in
patient or out-patient treatment. Half of them required a second hospitalization
and a quarter required a third hospitalization for the eating disorder. At follow
up, 68% of the total sample did not have an eating disorder. The prediction of
outcome revealed different patterns of risk variables depending on the type of
criterion. CONCLUSION: The outcome of adolescent eating disorders is relatively
similar across cultures, and better than in patients with later onset of the
disorder.
PMID- 10674952
TI - Dangerous female psychiatric patients: prevalences and characteristics.
AB - OBJECTIVE: We wanted to study the prevalence and characteristics of dangerousness
among female psychiatric patients. METHOD: A national survey was performed in
Norway, covering all psychiatric in- and out-patient units. RESULTS: There were
329 persons reported to have a psychiatric disorder and to satisfy our criteria
for dangerousness, giving a total prevalence of 9.9/100000 adults. There were 54
women, giving a female prevalence of 3.1/100 000. When compared to a matched
sample of the men, fewer women were out-patients or had had jail sentences. We
found no sex differences with regard to frequencies of psychosis, mental
retardation, personality disorders, or drug or alcohol abuse. The women had an
increased frequency of suicide-related and self-injurious behaviours and previous
commitment for arson. CONCLUSION: The prevalence of women with psychiatric
disorders who are considered to be dangerous was 3.1/100 000. The dangerous men
did not show higher frequencies than the women for psychopathology, drug abuse,
behaviour or criminality.
PMID- 10674953
TI - Sources of coercive behaviours in psychiatric admissions.
AB - OBJECTIVE: Coercion during psychiatric admissions has been a topic of debate for
many years. Although there has been considerable research on patients'
perceptions of coercion, there has been no work on who places pressures on
patients to be admitted. METHOD: This article integrates interview data from
interviews with patients, admitting staff and family and friends to describe the
pressures brought to bear on patients to be admitted. RESULTS: Health-care
professionals appear to be the most important source of pressures on patients,
and to have the most impact on patients' perceptions of coercion. However, there
are differences in type of pressure, and the pressures used by family and friends
appear to have the most longstanding impact. CONCLUSION: Legal and clinical
efforts to reduce the level of coercive pressures on patients need to recognize
the importance of mental-health professionals, including especially those who are
not legally mandated to participate in the admission process.
PMID- 10674954
TI - 'Everybody looks at my pubic bone'--a case report of an adolescent patient with
body dysmorphic disorder.
AB - OBJECTIVE: Body dysmorphic disorder (BDD) was described for the first time more
than 100 years ago, but it is still unknown to many clinicians. Although the
onset usually occurs during adolescence, BDD has received little attention in the
adolescent psychiatric literature. METHOD: The case and treatment of a 16-year
old female patient is described. RESULTS: The patient, suffering from the
overvalued belief of a dislocated pubic bone, a comorbid mild depressive episode,
BDD associated rituals and social avoidance, was treated successfully with a
combination of exposure and response prevention and 125 mg/day of doxepine.
CONCLUSION: If BDD is diagnosed early in the course and treated appropriately, it
is possible to obtain a satisfying outcome.
PMID- 10674955
TI - Dynamics of mucosal dimensions after root coverage with a bioresorbable membrane.
AB - BACKGROUND: So far, the clinical effects of the placement of a resorbable
membrane for guided tissue regeneration have not been studied in humans in great
detail. The dynamics of the resorptive processes, in particular, appear to be
rather speculative. In the present longitudinal study, specific alterations of
the dimensions of the dentogingival mucosa were explored after surgical root
coverage by using a bioresorbable membrane and a coronally-repositioned flap.
METHODS: The study population consisted of 14 patients with a total of 31
predominantly shallow, Miller class I, II or III recessions. The thickness of the
masticatory and lining mucosa before and after surgical intervention was measured
with an ultrasonic device. RESULTS: Mean (+/-sd) recession depth and width were
2.85+/-1.29 and 4.46+/-1.14 mm, respectively. After 12 months, 51+/-29% of the
recession depth (p<0.001) and 13+/-35% of its width (n.s.) were covered. Root
coverage seems to be rather defect-type sensitive with best results obtained at
canines with relatively shallow recessions. Mucosal thickness was considerably
increased after surgery with a gradual decrease during the following 9 months.
Thus, thickness of the marginal tissue rose from 0.82+/-0.27 mm to 1.49+/-0.54 mm
3 months after placement of the membrane (p<0.001). After 12 months, a mean
thickness of 1.03+/-0.40 mm was observed (p<0.001). Even more pronounced
alterations were noted for the alveolar lining mucosa with a threefold increase
of thickness 3 months after surgery and a gradual decrease to about 1 mm after 12
months. CONCLUSIONS: The present results point to the considerable space making
capacity of the bioresorbable membrane which probably allows for the ingrowth of
a granulation tissue derived from the underlying structures. The gradual decline
in mucosal thickness between months 6 and 9 after surgery may be paralleled by
the maturation of the granulation tissue while complete resorption of the
membrane had been accomplished.
PMID- 10674956
TI - Stain, plaque and gingivitis reduction by combining chlorhexidine and
peroxyborate.
AB - BACKGROUND: Previous studies have shown that using an oxidising agent in addition
to chlorhexidine reduces staining. AIM: The purpose of the present study was to
investigate whether, compared to chlorhexidine alone, the use of an oxidising
mouthrinse as an adjunct to chlorhexidine is efficacious in reducing stain,
plaque and gingivitis. METHOD: This study had a single-blind, 2-group parallel
design, including a 14-day experimental non-brushing period during which 1 group
(n= 14) used chlorhexidine alone (CHX) (chlorhexidine mouthrinse, 0.12% Oral-B
laboratories, Ireland), and the other (n= 14) used chlorhexidine in combination
with an oxidising agent (sodiumperborate-monohydrate-Bocasan, Oral-B
laboratories, Ireland). Patients were randomly assigned to either group. All
participants received a scaling and polishing before the start of the trial. No
oral hygiene instructions were given. Since, at the start of the experiment, all
stain and plaque were removed, only the gingival condition was evaluated at
baseline by means of bleeding on marginal probing. The examination after 14 days
of rinsing included the evaluation of plaque, bleeding on marginal probing and
stain (GMSI: gingival modification of the stain index). RESULTS: The results
showed at day 14, a significant difference between the 2 groups for plaque (CHX:
0.18, CHX+PER: 0.08, p=0.03) and gingival bleeding (CHX: 0.38, CHX+PER: 0.21,
p<0.001). The proportion of stained surfaces was less in the CHX+PER group (28%),
than in the chlorhexidine group (48%) (p=0.04). CONCLUSIONS: In conclusion, the
adjunctive use of an oxidising agent peroxyborate to chlorhexidine, proved to be
superior to chlorhexidine alone with regard to the inhibition of plaque and
development of gingivitis. In addition, the proportion of stained surfaces was
significantly less when adding the oxidising mouthrinse to chlorhexidine.
PMID- 10674957
TI - Evaluation of accuracy and variability of scoring-area-based plaque indices. A
laboratory model.
AB - BACKGROUND: Plaque scoring, using a variety of indices and methods, is widely
used in clinical dentistry. There is limited information on inter- and intra
examiner variability and almost no data on examiner accuracy. AIMS: The aim of
this study, was to determine the inter- and intra-examiner variability and
accuracy of 15 examiners, of differing plaque-scoring experience, in recording
and judging plaque areas from simulated plaque on tooth charts. METHODS: Plaque,
shaded red, was drawn onto tooth charts of 8 simulated "patients" and measured by
planimetry by 1 investigator. For each tooth for each "patient", examiners
subjectively copied the plaque onto blank charts and scored plaque in 5%
increments for the global plaque index. This was repeated on 2 occasions. Drawn
plaque areas were determine by the investigator and comparisons made with the
actual areas and % scores of plaque. RESULTS: For both plaque recording methods,
intra-examiner variability was low and slightly better than inter-examiner
variability. Reproducing plaque areas showed a high level of accuracy in most
examiners, as was judging areas in 5% increments, albeit slightly less accurate
than area drawing. Overall examiner experience had little influence on judging
plaque areas. CONCLUSION: The data suggest that area-based plaque indices can be
scored or recorded accurately and with minimal variability within or between
examiners. The laboratory model could be used to train and assess examiners.
PMID- 10674958
TI - Explanatory models for clinical and subjective indicators of periodontal disease
in an adult population.
AB - BACKGROUND: The aim of this study was to analyze indicators of periodontal
disease using: (1) community periodontal index of treatment needs (CPITN), (2)
subjectively reported change of front teeth position, and 3) subjectively
reported gingival bleeding. METHOD: These 3 indicators were used in models with
explanatory variables from 4 domains: (A) socio-economic attributes, (B) general
health and health-related lifestyle, (C) dental attitudes and behaviors, and (D)
dental status expressed as (number of teeth and DFT) for the clinically
determined dependent variables. In 1992, the study was carried out cross
sectionally in all 50-year olds in 2 Swedish counties using a questionnaire
(n=6343) and clinical investigation of a 20 % sub-sample (n= 1040). RESULTS:
Multiple and logistic regression analysis showed that explanatory patterns varied
for the clinical and subjective indicators. Use of tobacco had strong effects in
all models as did high care utilization. There were few associations with socio
economic attributes. The 2 subjective indicators "changed front position" and
"gingival bleeding" associated with attitudes, behaviors and subjective health.
Number of teeth and DFT covaried with clinical indicators. CONCLUSIONS: The main
conclusions from this study are: (1) that it is possible to find multivariate
models with acceptable goodness of fit for prediction of occurrence of
periodontal indicators, and (2) that the lack of relation between social
attributes and the disease gives arguments for a biological provenance of
periodontitis.
PMID- 10674959
TI - The effect of scaling and root planing on the clinical and microbiological
parameters of periodontal diseases: 12-month results.
AB - BACKGROUND/AIMS: Previously, we reported that SRP resulted in a decrease in mean
pocket depth and attachment level and reduced prevalence and levels of
Bacteroidesforsythus, Porphyromonas gingivalis, and Treponema denticola at 3 and
6 months post-SRP in 57 subjects with adult periodontitis. 32 of the 57 subjects
were monitored at 9 and 12 months. Thus, the purpose of the present investigation
was to evaluate the microbial and clinical effects of SRP in 32 (mean age 48+/
11) subjects over a 12-month period. METHOD: Clinical assessments of plaque,
gingival redness, suppuration, bleeding on probing, pocket depth and attachment
level were made prior to SRP and at 3, 6, 9, and 12 months post-therapy.
Subgingival plaque samples were taken at each visit and analyzed using the
checkerboard DNA-DNA hybridization technique for the presence and levels of 40
subgingival species. Each subject also received maintenance scaling at each of
the subsequent monitoring visits. Differences in clinical parameters and
prevalence and levels of bacterial species were analyzed pre- and post-therapy
using the Wilcoxon signed ranks test. The Quade test for related samples was used
for analysis of multiple visits. RESULTS: Mean pocket depth (mm+/-SEM) decreased
from 3.2+/-0.3 at baseline to 2.9+/-0.3 at 12 months (p<0.01). Mean attachment
level showed significant reduction at 6 months, but did not diminish further.
Bleeding on probing and plaque were significantly reduced at 12 months (p<0.001,
p<0.05, respectively). P. gingivalis, B. forsythus and T. denticola decreased in
prevalence and levels up to the 6-month visit and remained at these lower levels
at 9 and 12 months. Significant increases in levels and prevalence were noted at
12 months for Actinomyces naeslundii genospecies 2, Actinomyces odontolyticus,
Fusobacterium nucleatum ss polymorphum, Streptococcus mitis, Capnocytophaga sp,
and Veillonella parvula. CONCLUSIONS: The data suggest that the maintenance phase
of therapy may be essential in consolidating clinical and microbiological
improvements achieved as a result of initial therapy.
PMID- 10674960
TI - Comparative effects of quaternary ammonium mouthrinses on 4-day plaque regrowth.
AB - BACKGROUND: Quaternary ammonium compounds constitute a large group of
antibacterial chemicals with a potential for inhibiting plaque and gingivitis.
One compound, benzalkonium chloride (BC), may be of value, although there is a
dearth of evidence to support efficacy. The aim of this study was to measure the
ability of 2 BC mouthrinses (0.05% and 0.1%) to inhibit de novo plaque
reformation. METHOD: A 4-day plaque regrowth model. For comparative purposes, a
commercial mouthrinse containing cetyl pyridinium chloride (CPC) and a positive
control chlorhexidine (CX) mouthrinse were also evaluated. RESULTS: Compared to
water control, a reduction in plaque scores of 52% was noted for the CX
mouthrinse, 22.5% for CPC and 5% and 6% for the 2 BC rinses. For plaque area,
reductions of 84%, 47%, 16% and 15% were found for CX, CPC, and the 2 BC rinses,
respectively. Significant reductions in plaque area compared to the water rinse
were also seen with the 2 BC rinses (p<0.05). However, for both plaque score and
plaque area, the CX and CPC rinses significantly reduced plaque compared to the
BC rinses (p<0.0001). CONCLUSIONS: These findings would suggest that the 2
benzalkonium rinses would only have a limited value at inhibiting plaque
formation.
PMID- 10674961
TI - Characterization of bone resorbing activity in gingival crevicular fluid from
patients with periodontitis.
AB - BACKGROUND: In attempts to elucidate factors stimulating bone resorption in
patients with different inflammatory diseases in the vicinity of the skeleton,
e.g., peridontal disease and rheumatoid arthritis, we are investigating the
presence of bone-resorbing activity in a variety of inflammatory exudates. The
aim of the present study was to characterize the bone-resorbing activity present
in patients with periodontitis. METHODS: Bone-resorbing activity was assessed in
gingival crevicular fluids (GCFs) collected from patients with periodontitis and
from patients with no signs of gingivitis. Bone-resorbing activity was evaluated
by analyzing the capacity of GCFs to stimulate the release of minerals and the
breakdown of bone matrix proteins in cultured neonatal mouse calvariae. The
concentrations of IL-1alpha, IL-1beta and PGE2 were determined with ELISA and RIA
techniques, respectively. RESULTS: GCF eluates from 24 different healthy sites
caused a 1.23+/-0.05 fold stimulation of 45Ca release, whereas GCF eluates from
45 different diseased (periodontitis) sites caused a 2.46+/-0.10 fold
stimulation. The effect on 45Ca release was time- and concentration-dependent,
inhibited by 3 different osteoclast inhibitors and associated with enhanced
release of 3H from [3H]-proline-labelled bones. The activity in GCF causing
enhanced 45Ca release was unaffected, or in some samples partially reduced, by
ultrafiltration using a filter with a molecular weight cut-off of 3000 Daltons.
The bone-resorbing activity was temperature sensitive (+90degrees C, 10 min). The
concentrations of prostaglandin E2 (PGE2) in the diluted GCF eluates, used in the
bone resorption bioassay, were too low to be responsible for the release of 45Ca.
Antisera specifically neutralizing human IL-1a inhibited the stimulatory effect
of GCF pooled from several diseased sites. The specific, recombinant human IL-1
receptor antagonist completely inhibited the effect of pooled GCFs. GCF eluates
from diseased sites contained human IL-1alpha and IL-1beta at concentrations of
1838+/-294 pg/ml and 512+/-91 pg/ml, respectively. CONCLUSIONS: These data show
that GCF contains activity(ies) stimulating osteoclastic bone resorption in
vitro. The factor primarily responsible for this activity seems to be IL-1alpha,
but IL-1alpha is not the sole activator of bone resorption in GCF.
PMID- 10674962
TI - Concentration of 3 tetracyclines in plasma, gingival crevice fluid and saliva.
AB - BACKGROUND: Systemically-administered tetracyclines have been used widely for
treatment of periodontal diseases with little understanding of their delivery
characteristics to periodontal tissues. This study was designed to measure
concentrations of 3 tetracyclines in gingival crevice fluid (GCF), plasma and
saliva of following systemic administration. METHOD: The concentration of
tetracycline (TC), minocycline (MN) and doxycycline (DX) was measured in gingival
crevice fluid (GCF), plasma and saliva of 20 subjects following single sequential
standard oral systemic doses. Gingival crevice fluid concentration was measured
at 4 sites (2 shallow and 2 deep) before administration, and at 1 h and 2 h
following administration. Plasma and saliva concentrations were measured from in
samples at the same time points. No antibacterial activity was detected before
administration. The highest concentrations were measured 2 h after
administration. RESULTS: The average concentrations at 2 h were highest in plasma
(TC = 1.02, MN=2.18, DX=2.35 microg/ml). Intermediate concentrations were
measured in GCF (TC=0.61, MN= 1.49, DX= 1.65 microg/ml). Saliva concentrations
(TC=0.09 MN=0.31, DX=0.47 microg/ml) were the lowest of the 3 fluids monitored.
Data are presented indicating that the average GCF concentration of systemically
administered tetracyclines is less than the that of plasma concentration. The
concentration of tetracyclines in GCF was strongly associated with plasma
concentration, indicating a primary role of drug absorption in the delivery of
these systemically administered antibiotics to the site of action in periodontal
therapy. The average GCF concentration in individuals varied widely (between 0
and 8 microg/ml) with approximately 50% of samples not achieving levels of 1
microg/ml. CONCLUSION: These observations suggest that poor absorption of orally
administered tetracyclines in many individuals may account for much of the
variability in clinical response to antibiotics observed in practice.
PMID- 10674963
TI - Exposure to tobacco smoking and periodontal health.
AB - BACKGROUND: The influence of smoking behavior on the periodontal health condition
was clinically and radiographically studied in 257 dentally aware adults in the
age range 20-69 years, including 50 current smokers, 61 former smokers and 133
non-smokers. AIMS: The clinical variables to be investigated were frequency of
diseased sites > or =4 mm, frequency of gingival bleeding sites and plaque index.
In addition, the periodontal bone height was radiographically assessed as a % of
the dental root length. METHODS: All variables were based on full-mouth
examinations including all teeth and periodontia. RESULTS: The observations
indicated an inferior periodontal health condition associated with smoking. This
was evidenced by a significantly greater frequency of diseased sites and a
significantly greater reduction of periodontal bone height in current smokers as
compared to non-smokers. The condition of former smokers was intermediate between
current smokers and non-smokers, suggesting that former smokers who have quit
smoking have a better periodontal health condition than current smokers, although
worse than that of non-smokers. The finding that former smokers exhibited less
disease than current smokers suggests that smoking cessation may be beneficial
and mitigate the untoward effects inflicted by smoking, allowing a normalization
towards non-smoker conditions. Heavy exposure was consistently associated with
more severe a condition than light exposure, suggesting that the relationship
between smoking exposure and periodontal morbidity is dose-dependent.
CONCLUSIONS: Altogether, the present observations identify a negative impact from
smoking on periodontal health and provide further evidence that tobacco smoking
is an avoidable risk for periodontal disease.
PMID- 10674964
TI - Leukocyte functions in 2 cases of Papillon-Lefevre syndrome.
AB - AIM: To investigate the role of leukocytes in the pathogenesis of Papillon
Lefevre syndrome (PLS). METHODS: Peripheral blood polymorphonuclear neutrophils
(PMNs), monocytes (MNs) and gingival crevicular fluid (GCF) were obtained from 2
cases of PLS with typical features. The chemotaxis of PMNs and MNs were evaluated
using a modified Boyden chamber. The adherence of PMNs was determined by
adherence of PMNs to petri dishes. Interleukin-8 (IL-8) in GCF was detected by
sandwich ELISA. Elastase activity in GCF was measured with a low molecular weight
substrate (S-2484) specific for granulocyte elastase. RESULTS: PMNs from both
patients showed depressed chemotactic response to FMLP and IL-8. Total amounts of
IL-8 in GCF from the 2 patients were much higher than those of the normal
controls. Elastase activity was not significantly different from that of the
controls. The adherence of PMN and the chemotaxis of MN in the 2 patients were
normal. CONCLUSION: The depressed chemotactic response of PMN leads to decreased
recruitment of PMN and/or release of lysozyme from PMN in the diseased gingival
tissue, increasing the susceptibility of PLS patients to periodontal infection.
PMID- 10674965
TI - After-effects of stress on crevicular interleukin-1beta.
AB - BACKGROUND: In a previous study, we found stress to increase crevicular
interleukin-1beta (Il-1beta) secretion induced by supragingival plaque. While in
that study, stress and plaque were presented concomitantly, we now wondered
whether a consecutive presentation of these 2 factors would still exert stress
effects. METHOD: 39 medical students participated in the study; 18 took part in a
major exam while the remaining 21 served as controls. From the day after the last
exam, students neglected oral hygiene in 2 antagonistic quadrants for 21 days
(experimental gingivitis), while they maintained perfect hygiene at the remaining
sites. Crevicular fluid samples were taken at days 0, 5, 8, 15, 18, and 21 of
experimental gingivitis. RESULTS: A significant effect of pre-exposure to
academic stress on crevicular Il-1beta concentration was found (area under the
curve: p=0.042), the effect size, however, being smaller than in our previous
study when stress and plaque were presented concomitantly. CONCLUSIONS: It is
concluded that pre-exposure to stress may persistently alter the immunological
effects of microbial challenge to the periodontium.
PMID- 10674966
TI - Hardy-Weinberg testing for HLA class II (DRB1, DQA1, DQB1, and DPB1) loci in 26
human ethnic groups.
AB - Testing the fit of population data to Hardy-Weinberg proportions is crucial in
the validation of many current approaches in population genetic studies. In this
paper, we tested fit to Hardy-Weinberg proportions using exact approaches for
both the overall and individual heterozygote genotype data of four HLA Class II
loci: DRB1, DQA1, DQB1, and DPB1, from 26 human populations. Eighty of 99 overall
tests fit the Hardy-Weinberg expectation (73% for DRB1, 89% for DQA1, 81% for
DQB1 and 81% for DPB1). Deviations from Hardy-Weinberg proportions were both
locus and group specific. Although we could not rule out other mechanisms at
work, the individual test results indicated that the departure was possibly
partly due to recent admixture. Evidence for selection and other sources of
deviation are also discussed.
PMID- 10674967
TI - HLA associations in type 1 diabetes among patients not carrying high-risk DR3-DQ2
or DR4-DQ8 haplotypes.
AB - Type 1 diabetes is a complex disease where numerous genes are involved in the
pathogenesis. Genes that account for approximately 50% of the familial clustering
of the disease are located within or in the vicinity of the HLA complex on
chromosome 6. Some DRB1, DQA1 and DQB1 genes are known to be involved, in
addition to as yet unidentified HLA-linked genes. The DR4-DQ8 and DR3-DQ2
haplotypes are known to confer high risk for developing the disease, particularly
when occurring together. Approximately 10% of patients, however, do not carry any
of these high-risk HLA class II haplotypes. We have performed genotyping of DRB1,
DQA1 and DQB1 alleles in non-DR3-DQ2/non-DR4-DQ8 patients and controls from
Sweden and Norway to test if any HLA associations were observed in these
patients. Our results clearly demonstrate several statistically significant
differences in the frequency of HLA haplotypes between patients and controls.
Case-control analysis including the relative predispositional effect test, and
transmission disequilibrium test (TDT) analysis in Norwegian type 1 diabetes
families revealed that the DQA1*03-DQB1*0301, DQA1*0401-DQB1*0402, DQA1*0101
DQB1*0501, DQA1*03-DQB1*0303 and DQA1*0102-DQB1*0604 haplotypes may also confer
risk. Our analyses also supported independent risks of certain DRB1 alleles. The
study clearly demonstrates that HLA associations in type 1 diabetes extends far
beyond the well-known associations with the DR4-DQ8 and DR3-DQ2 haplotypes. Our
data suggest that there is a hierarchy of HLA class II haplotypes conferring risk
to develop type 1 diabetes.
PMID- 10674968
TI - DQCAR 113 and DQCAR 115 in combination with HLA-DRB1 alleles are significant
markers of susceptibility to rheumatoid arthritis in the Korean population.
AB - We have investigated HLA region microsatellite polymorphisms in rheumatoid
arthritis (RA) which are known to be associated with HLA class II alleles in the
Korean population. Ninety patients with RA and 106 controls were employed for
this study, in which TAP1CA, DQCAR, D6S273, HLA-DRB1, -DQA1 and -DQB1 allele
typing were performed. DQCAR 113 (RR = 3.2, P<0.0002), DQCAR 115 (RR = 3.6,
P<0.0001) and heterozygous DQCAR 113/115 (RR = 11.2, P<0.0001) frequencies were
significantly increased in the RA group compared with the control group. The HLA
DRB1 genotypes of patients who had DQCAR 113/115 alleles were defined as DRB1*04
and/or DRB1*09. There was no significant difference between RA and controls in
D6S273 and TAP1CA allele frequencies. We demonstrated that HLA-DRB1*0405 (RR =
6.6, P<10(-6)), DQA1*03 (RR = 5.2, P<10(-6)), DQB1*04 (RR = 3.5, P<0.002) alleles
were useful markers of susceptibility to RA in Koreans. The frequency of HLA
DRB1*0405 was higher in DQCAR 113 allele-positive RA (68.1%) than in DQCAR 113
allele-negative (16.3%) and total RA (43.3%) groups, and the susceptibility risk
of DQCAR 113 allele to RA was more increased in the DRB1*0405-positive group (RR
= 5.5, P<0.04). On the other hand, DQCAR 115 allele was more significantly
associated with susceptibility to RA in HLA-DRB1*0405-negative patients (RR =
5.1, P<0.0005), and the association between RA and HLA-DRB1*0405 was also
significantly associated with DQCAR 115 allele-negative patients (RR = 13.2,
P<0.00001) as compared with DQCAR 115 allele-negative control groups. HLA
DRB1*0405-DQA1*03-DQCAR113-DQB1*03 haplotype showed high relative risk value (RR=
17.7, P<0.0002). In conclusion, the DQCAR allele in combination with HLA class
II, especially DR, is probably a useful risk marker for RA susceptibility in the
Korean population.
PMID- 10674969
TI - Trans-speciation maintenance in the MHC region of a polymorphism which includes a
polymorphic dinucleotide locus, and the de novo arisal of a polymorphic
tetranucleotide microsatellite.
AB - Alleles and the surrounding regions of DQCAR, a dinucleotide repeat tightly
linked to HLA-DQB1, were sequenced in a range of primate species including man.
Three polymorphic regions can usefully be defined in the description of these
sequences: the dinucleotide GT repeat itself, the anonymous region 5' of this
repeat, and a variable CTGT repeat in the 3' region. The 5' sequence displayed
six alleles in the individuals studied. One of these alleles was invariably
associated with substitutions in the GT repeat and absence of the CTGT repeat,
the others with pure, polymorphic GT repeats and variation in the numbers of CTGT
repeats. Haplotypes can be classified by the allele in the 5' region. Those
carrying allele 1 were only found in man, those with allele 2 in man, chimpanzee
and gorilla. The third haplotype (indicated by the presence of allele 3) was
found in chimpanzee, gorilla and orang-utan, the fourth in chimpanzee and gibbon,
the fifth in baboon, guenon and mangabey and the sixth in guenon and macaque. The
alleles in the 5' region, but from different species, are thus often more similar
than alleles from the same species, a phenomenon already shown for some HLA
genes. This suggests that major histocompatibility sequences and surrounding
sequences shared a correlated evolutionary history. The new polymorphic
tetranucleotide microsatellite (CTGT, 3rd region) has possibly arisen de novo
from the pre-existing dinucleotide GT. This study provides information not only
on the molecular evolution of this particular microsatellite but also of the
trans-speciation maintenance of polymorphism of its surrounding sequences.
PMID- 10674970
TI - Significant associations of HLA-B*5101 and B*5108, and lack of association of
class II alleles with Behcet's disease in Italian patients.
AB - Behcet's disease has been known to be strongly associated with human leukocyte
antigen (HLA) B51, one of the split antigens of HLA-B5. An increased incidence of
HLA-B51 in the patient group has also been reported in an Italian population.
Since the B51 antigen has been recently identified to comprise nine alleles,
B*5101-B*5109, we performed HLA-B51 allele genotyping by the polymerase chain
reaction-sequencing based typing (PCR-SBT) method as well as serological HLA-A
and -B typing among 21 Italian patients with Behcet's disease in order to
investigate whether there is any correlation of one particular B51-associated
allele with Behcet's disease. In addition, HLA class II genotyping was performed
by the PCR-restriction fragment length polymorphism (RFLP) method. As a result,
only the phenotype frequency of the B51 antigen was found to be significantly
increased in the patient group as compared to the ethnically matched control
group by the corrected P-value analysis (71.4% in patients vs. 17.9% in controls;
chi2 = 14.26, Pc = 0.0042, R.R. = 11.5). In the B51 allele genotyping, 11 out of
15 B51-positive patients were B*5101 and the remaining four were B*5108, whereas
all of 5 normal controls were B*5101, showing significant association of each
allele with Behcet's disease. No significant difference was observed between the
patient and control groups in the HLA class II allelic distribution. This study
revealed a strong association of Behcet's disease in Italian with B*5108 as well
as B*5101, providing important insight into the molecular mechanism underlying an
HLA association with Behcet's disease.
PMID- 10674971
TI - The CC-chemokine receptor 5 (CCR5) is a marker of, but not essential for the
development of human Th1 cells.
AB - The CC-chemokine receptor 5 (CCR5) has recently been described as a surface
marker of human T cells producing type 1 (Th1) cytokines. Here we confirm that
CCR5 is expressed on human Th1 but not on Th2 T-cell clones. Using intracellular
cytokine staining, we show that alloantigen specific CD4+ T-cell lines derived
from a CCR5-deficient individual (delta32 allele homozygote) contain high numbers
of both interferon gamma (IFN-gamma) and interleukin (IL)-2 producing cells, low
numbers of IL-10 producing cells and no IL4 or IL-5 producing cells when
stimulated with phorbol ester and ionomycin in vitro. These results were similar
to those obtained from alloantigen specific CD4+ T-cell lines derived from CCR5
expressing individuals. An enzyme-linked immunoabsorbent assay (ELISA) confirmed
that the Th1 cytokine-positive cells from the CCR5-deficient individual were able
to produce equal amounts of cytokines when compared to T-cell lines from CCR5
expressing individuals, These results demonstrate that CCR5-negative T cells
display the same capacity of Th1 T-cell differentiation as T cells derived from
CCR5-expressing individuals. Thus, CCR5 expression is not essential for
differentiation of human Th1 T cells.
PMID- 10674972
TI - Lack of a strong association of CTLA-4 exon 1 polymorphism with the
susceptibility to rheumatoid arthritis and systemic lupus erythematosus in
Japanese: an association study using a novel variation screening method.
AB - CTLA-4 is considered to be one of the attractive candidates for the
susceptibility genes to rheumatic diseases. In the present study, the association
of CTLA-4 polymorphism with rheumatoid arthritis (RA) and systemic lupus
erythematosus (SLE) was examined in the Japanese population using the case
control association analysis. Polymerase chain reaction-preferential homoduplex
formation assay (PCR-PHFA) was applied for the screening of genetic variations
and for the genotyping of a large number of samples. A greater proportion of
Japanese patients with RA (44%) and SLE (44%) compared with healthy individuals
(37%) had exon 1 49 G/G genotype, but the difference did not reach statistical
significance. However, when the patients with RA and healthy individuals were
stratified according to HLA-DRB1 alleles, a weakly significant increase of the
positivity of CTLA-4 49G allele was observed in HLA-DRB1*0405-positive patients
(87%) compared with DRB1*0405-positive healthy individuals (71%) (P = 0.014, odds
ratio = 2.77). These results indicate that CTLA-4 exon 1 polymorphism does not
contribute greatly to the susceptibility to RA and SLE, at least in Japanese,
although the presence of CTLA4 49G allele could be a minor predisposing factor
for RA in HLA-DRB1*0405-positive individuals. In addition, PCR-PHFA was shown to
be useful for a mass screening of gene variations.
PMID- 10674973
TI - Polymorphic analysis of the high-affinity tumor necrosis factor receptor 2.
AB - The tumor necrosis factor receptor 2 (TNF-RII, CD120b, TNF-R p75/80) gene has
recently been characterised. It is located on chromosome 1p362 and consists of 10
exons and 9 introns A number of biallelic polymorphisms have been found in exons
4, 6, 9 and 10 based on differences between published sequences. In this study we
have used polymerase chain reaction methodology in association with sequence
specific primers (PCR-SSP) incorporating mismatches at the 3' end to identify
these polymorphisms. We were able to confirm the presence of a single biallelic
polymorphism in exon 6 corresponding to a (T/G) at nucleotide 676 of TNF-RII mRNA
(gb:M32315) which results in an amino acid change and three biallelic
polymorphisms in exon 10 (in the3'UTR) corresponding to (A/G) at nucleotide 1663,
(T/G) at nucleotide 1668 and a (C/T) at nucleotide 1690 of gb:M32315, whereas no
polymorphisms were observed in exons 4 and 9. Here we report that in 192
unrelated UK Caucasian individuals the allele frequencies determined by direct
counting were: 676-T (0.77), 1663-G (0.51), 1668-T (0.95), and 1690-T (0.64) and
the calculated gene frequencies were; 676-T (0.52), 676-G (0.12); 1663-G (0.30),
1663-A (0.28); 1668-T (0.77), 1668-G (0.025); and 1690-T (0.40), 1690-C (0.20).
Furthermore, the presence of an A allele at nucleotide position 1663 was found to
be strongly associated with the presence of a C allele at nucleotide position
1690 and a G allele at nucleotide position 1668 whereas the presence of a G
allele at position 1663 was associated with the absence of a C allele at
nucleotide position 1690.
PMID- 10674974
TI - Immunogenicity of P/Q-type calcium channel in small cell lung cancer:
investigation of alpha1 subunit polyglutamine expansion.
AB - The ectopic expression of neuronal P/Q-type voltage-gated calcium channels in
small cell lung carcinoma (SCLC) is thought to induce antisynaptic autoimmunity
in the paraneoplastic Lambert-Eaton myasthenic syndrome. The gene CACNL1A4,
encoding the principal (alpha1A) subunit of this calcium channel, is mutated in
several inherited neurological disorders. One of these disorders (spinocerebellar
ataxia, type 6, or SCA-6) involves the expansion of a trinucleotide (CAG) repeat
unit. We hypothesized that a somatic CAG repeat instability of this gene in
neoplastic cells might generate a non-self epitope capable of initiating
autoimmunity to P/Q-type calcium channels. We therefore analyzed the CACNL1A4
gene in SCLC lines established from metastases derived from seven individual
patients (four associated with Lambert-Eaton myasthenic syndrome, one associated
with myasthenia gravis, and two not associated with neurological autoimmunity).
We compared their CAG repeat numbers (determined by polymerase chain reaction
(PCR) amplification followed by separation of products on a 6% polyacrylamide/8M
urea gel) to published norms and to DNA from a patient with SCA-6. The number of
CAG repeats in SCLC DNA fell within a normal range whether or not the neoplasm
was complicated by neurological autoimmunity. Therefore, it is unlikely that
somatically unstable CAG repeat units in the gene encoding the P/Q-type voltage
gated calcium channel account for this tumor protein's immunogenicity in the
Lambert-Eaton myasthenic syndrome.
PMID- 10674975
TI - In vitro exposure of acute promyelocytic leukemia cells to arsenic trioxide
(As2O3) induces the solitary expression of CD66c (NCA-50/90), a member of the CEA
family.
AB - Arsenic trioxide (As2O3) is a useful drug for the treatment of acute
promyelocytic leukemia (APL), acting through a complex mechanism involving the
induction of apoptosis. We investigated by flow cytometry whether in vitro
treatment of APL leukemic cells with As2O3 determined specific surface membrane
changes. Twelve APL bone marrow aspirates were analyzed following 7 days of in
vitro treatment with As2O3 (0.25, 0.5 and 2.5 microM) with regard to the
expression of a series of differentiation antigens. Twelve acute myeloid leukemia
(AML) samples of non-APL morphotype were analyzed as controls. Exposure of APL as
well as non-APL samples to any concentration of As2O3 did not affect the
expression of beta2 integrins (CD11a and CD11b), CD45 isoforms (RA, RB and R0),
CD44/H-CAM, CD33 and the CEA-related antigen family members CD66ade and CD66b,
thus failing to disclose any maturating effect. Of interest, in all APL samples
(but not in AML) every tested dose of As2O3 determined a dramatic upregulation of
CD66c display; intermediate concentration (0.5 microM) of As2O3 increased the
median percentage of CD66c+ cells from 5% in control cultures (25th-75th
percentile 2-12%) to 80% in drug-exposed cultures (25th-75th percentile 58-90%)
(P<0.001). The induction of solitary expression of CD66c is a new finding which
demonstrates As2O3 capability of generating phenotypic changes absolutely
restricted to APL cells Moreover, these results provide experimental basis for
considering the involvement of the newly described CD66 signalling pathway in
As2O3-driven programmed cell death.
PMID- 10674976
TI - High-throughput class I HLA genotyping using fluorescence resonance energy
transfer (FRET) probes and sequence-specific primer-polymerase chain reaction
(SSP-PCR).
AB - We have developed a semi-automated HLA class I typing system utilising TET/TAMRA
labelled fluorescence resonance energy transfer (FRET) hydrolysis probes. The
results from 87 individuals are in full concordance with serology and
conventional gel-based systems. This assay replaces labour-intensive conventional
gel-based DNA typing and has a higher allelic resolution than serology. Our
approach differs from previously published fluorogenic probe typing protocols in
that it provides simultaneous typing of HLA-A, -B and -C loci to medium
resolution. Furthermore, by using equipment that is not specific to FRET probe
analysis our system has in-built expansion capacity to 384 reactions per plate,
thus making it applicable to high-throughput population screening. Automation is
achieved through the use of computer software which analyses direct input from
the fluorescence reader, allowing high throughput with a low inherent error rate.
PMID- 10674977
TI - Mhc-DQ-DRB haplotype analysis in the rhesus macaque: evidence for a number of
different haplotypes displaying a low allelic polymorphism.
AB - In the HLA-DRB subregion of man, five major groups of haplotypes, often
displaying a remarkable polymorphism, are distinguishable. The polymorphism is
thought to be generated by point mutation, microgene conversion and gene
rearrangement by recombination. In order to gain insight into the organization of
the rhesus macaque major histocompatibility complex (MHC) class II region, DRB
genes from monkeys of different origins previously typed for their DQ genes were
analyzed. At first DRB haplotypes were deduced from DQ-homozygous monkeys. The
stability of these haplotypes was then examined in DQ-heterozygous monkeys by
sequence-based typing for the presence of members of the DRB1*03 and DRB1*04
lineage, and for seven single alleles detected on the haplotypes. Six DRB
haplotypes linked to the five most frequent and three haplotypes linked to less
frequent DQ haplotypes were identified. Six novel DRB alleles were detected. The
number of DRB genes per haplotype varied between two and four. The results
altogether suggest that in rhesus macaques, in comparison to man, the DQ
haplotypes are linked to only a small number of DRB haplotypes, the number and
diversity of DRB haplotypes is larger, and the allelic polymorphism of a given
haplotype is smaller. The diversity of the DRB haplotypes was partly due to the
varying number and identity of genes linked to DRB1*03 and DRB1*04. Furthermore,
the number of DRB1 genes themselves varied from zero to two.
PMID- 10674978
TI - HLA-B*4021: hybrid linking the B15 and B40 families.
AB - Twenty alleles encoding molecules with the B60 or B61 serologic specificity have
been reported thus far. This study characterized a new allele encoding a molecule
exhibiting partial serologic reactivity with B15- and B40-related alloantisera
from unrelated Korean individuals. Based on the DNA sequence, it appears that the
novel allele has a sequence identical to some of alleles in B*15 family including
B*1501 in exon 2. The sequence in exon 3, however, is identical to alleles in the
B*40 family (B*4001/07/10/12) and B*4803. This implies that the novel allele,
B*4021, has evolved by a reciprocal gene recombination involving members of these
two families. The haplotype associated with B*4021 is likely to be A11-Cw4-B*4021
DRB1*04-DRB4*01-DQA1*03-DQB1*0301 .
PMID- 10674979
TI - Antibody responses to a mucosally delivered HIV-1 gp120-derived C4/V3 peptide.
AB - T1-SP10MN(A) is a synthetic peptide containing a T-helper (Th), cytotoxic T cell
(CTL) and a B-cell epitope derived from the HIV-1 gp120 envelope protein. This
peptide can elicit both systemic and mucosal antibody responses following nasal
immunization in various species. In the present study, three different mucosal
immunization strategies were performed in rabbits to determine which induced a
more vigorous antibody response to T1-SP10MN(A). Nasal immunization followed by
nasal boosting was found to be superior at inducing both serum IgG and vaginal
secretory IgA (S-IgA) when compared to nasal followed by vaginal boosting.
Conversely, vaginal priming followed by vaginal boosting elicited minimal serum
IgG and vaginal S-IgA responses to T1-SP10MN(A), but moderate levels of vaginal
IgG were detected. This study further demonstrates that vaginal immune responses
can be elicited by immunization at distant and local mucosal sites.
PMID- 10674980
TI - LPS mediated production of IL-1, PGE2 and PGF2alpha from term decidua involves
tumour necrosis factor and tumour necrosis factor receptor p55.
AB - Prostaglandins, with cytokines involved as intermediate factors, may have an
essential role in premature labour when infection is present. We therefore wanted
to study tumour necrosis factor (TNF), in cytokine and prostaglandin production
in reproductive tissue. Decidual cell cultures were established and cells were
stimulated with lipopolysaccharides (LPS). Media concentrations of TNF,
interleukin-1 (IL-1), IL-6 and prostaglandin E2 and F2alpha were analysed, and
involvement of LPS receptor CD14, TNF and TNF receptors (p55 and p75) were
analysed, by studying effects after administration of specific antibodies. LPS
induced an early peak elevation of TNF, with a subsequent release of IL-1, IL-6
and prostaglandins. Antibodies against CD14 inhibited these LPS effects. TNF
antibodies reduced production of IL-1 and prostaglandins, whereas no significant
influence on IL-6 production was observed. Antibodies against the TNF receptor
p55 reduced all observed TNF effects. In contrast, p75 antibodies did not
influence cytokine or prostaglandin production in this system. Our results
suggest that increased TNF production is a prerequisite for LPS stimulated
production of IL-1 and prostaglandins from decidual cells. LPS may directly
stimulate IL-6 production. Of the two TNF receptors studied, only p55 seemed to
be involved in the TNF signal transduction.
PMID- 10674981
TI - MUC1/episialin: a critical barrier in the female reproductive tract.
AB - The female reproductive tract must resist microbial infections as well as support
embryonic development, implantation and placentation. Reproductive tract mucins,
in general, and Muc1/episialin, in particular, play key roles in implantation
related events and in protection from microbial infection. High levels of mucin
expression in the lower reproductive tract presumably affords protection against
infection while down-regulation of uterine mucins has been suggested to provide
access to the uterine surface. The present studies demonstrate that mucins,
particularly Muc1, are effective barriers to embryo attachment. Furthermore, a
strain of female Muc1 null mice in normal housing displays chronic infection and
inflammation of the lower reproductive tract and markedly reduced fertility
rates. This phenotype is not observed when Muc1 nulls are housed in a pathogen
free environment indicating that this phenotype results from chronic microbial
exposure. Only normal endogenous flora were isolated from the reproductive tracts
of affected Muc1 null mice, suggesting that these bacterial species become
opportunistic with loss of the mucin barrier. Staphylococcal adherence to lower
reproductive tract epithelia was found to be mediated by cell surface mucin
carbohydrates. Collectively, these studies demonstrate a critical barrier role
for Muc1 in various aspects of female reproductive tract physiology.
PMID- 10674982
TI - Antisperm antibodies: a critical evaluation and clinical guidelines.
PMID- 10674983
TI - T cell transformation with Herpesvirus saimiri: a tool for neuroimmunological
research.
AB - The finite life span of human T lymphocytes and their requirement of regular
restimulation frequently limit human T cell studies. Once infected with H.
saimiri, however, human and monkey T cells are transformed to stable growth
without the need for further restimulation. H. saimiri persists in human growth
transformed T cells episomally and only a few viral genes are expressed. The
release of infectious virus from transformed human T cells has not been observed.
H. saimiri-transformed T cells have the phenotype of mature activated CD4+ or
CD8+ T cells. Transformed T cells retain a structurally and functionally intact T
cell receptor and respond specifically to recognition of their antigen. They
produce Th1-like cytokines, provide B cell help, can be triggered to become
cytotoxic, and are sensitive to a variety of apoptosis-inducing treatments. While
H. saimiri-transformed T cells resemble native T cells in numerous aspects, their
reactivity to CD2 is strikingly different: Native T cells are activated via CD2
by certain pairs of mAbs, but not by the mere binding of CD2 to its ligand CD58.
In contrast, H. saimiri-transformed T cells are activated by a single crosslinked
anti-CD2 mAb and also by interaction with CD58-bearing cells.
PMID- 10674984
TI - Humoral immune responses to adenovirus vectors in the brain.
AB - We have investigated the humoral immune response to E1-deleted adenovirus vectors
encoding the lacZ gene introduced into the brains of mice. Injection of these non
replicating vectors into the brain induced systemic antibody production to
adenovirus vectors in dose dependent manner. Apparent antibody production to beta
galactosidase, the product of the lacZ gene, was detected later than anti
adenovirus antibody. Neutralizing antibody was not detected. This study
demonstrates that E1-deleted adenovirus vectors injected into the brain trigger
humoral immune responses to the adenovirus and its gene products, but they are
not sufficient to block the infection of cells by adenovirus upon repeat
injection.
PMID- 10674985
TI - Bone marrow-derived dendritic cells pulsed with tumor homogenate induce immunity
against syngeneic intracerebral glioma.
AB - To evaluate the efficacy and toxicity of dendritic cell (DC) based therapy for
intracerebral gliomas, we utilized a cell line derived from an astrocytoma that
arose spontaneously in a VM/Dk mouse. This astrocytoma mirrors human gliomas
phenotypically, morphologically and secretes transforming growth factor (TGF)
betas, immunosuppressive cytokines secreted by human gliomas. Systemic
vaccination of mice with DCs pulsed with tumor homogenate followed by
intracranial tumor challenge produced a > 160% increase in median survival (p =
0.016) compared with mice vaccinated with PBS or unpulsed DCs (p = 0.083). Fifty
percent of mice treated with pulsed DCs survived long-term. Immunologic memory
was demonstrated by survival of mice rechallenged with tumor. Both cell-mediated
and humoral immunity was induced. On histological examination only focal areas of
demyelination at the tumor implantation site were present. There was no evidence
that autoimmune encephalomyelitis was induced by DC vaccination. Therefore, in a
murine model, vaccination with DCs pulsed with glioma tumor homogenate is a safe
and effective therapy against a syngeneic glioma located in the immunologically
privileged central nervous system (CNS).
PMID- 10674986
TI - Tubby-like protein 1 as an autoantigen in cancer-associated retinopathy.
AB - Cancer-associated retinopathy (CAR) is a rare paraneoplastic syndrome that is
characterized by retinal degeneration. Two cDNA clones, recoverin and tubby-like
protein 1 (TULP1), were isolated from a human retinal cDNA library by using serum
from a CAR patient as the probe. Both recoverin and TULP1 are retina-specific
protein, and TULP1 is a member of tubby gene family. A determination of the
recognized amino acid sequence of TULP1 by the patient serum and
immunohistochemical studies on the distribution of TULP1 in the retina were done
in this study.
PMID- 10674987
TI - Differential involvement of sympathetic nervous system and immune system in the
modulation of TNF-alpha production by alpha2- and beta-adrenoceptors in mice.
AB - In the present study, the regulation of tumor necrosis factor-alpha (TNF-alpha)
production by alpha2- and beta-adrenoceptors located on noradrenergic nerve
terminals and on macrophages was studied in endotoxaemic mice. We found that
reduction of the sympathetic outflow by reserpine dramatically increased the
lipopolysaccharide (LPS)-induced TNF-alpha production, demonstrating that the
release of endogenous noradrenaline (NA), controlled by presynaptic alpha2
adrenoceptors, was a determinant factor in this model. By using alpha2- and beta
adrenergic drugs (clonidine, CH-38083, isoproterenol, propranolol) we provided
the first in vivo evidence that, beside the dominance of neuronal alpha2- and
macrophage beta-adrenoceptors, the alpha2-adrenoceptors on macrophages were also
involved in the modulation of LPS-induced TNF-alpha production. Since adrenergic
drugs are widely used in the clinical practice, our findings may have
therapeutical implications.
PMID- 10674988
TI - Functional and molecular characterization of VIP receptor--effector system in rat
developing immunocompetent cells: G protein involvement.
AB - Changes in the functional characteristics for vasoactive intestinal peptide (VIP)
receptor-effector system were evaluated in rat developing immunocompetent cells
(from 1-week-old animals up to 12-week-old animals). These characteristics
include [125I]VIP binding studies, cell cyclic AMP (cAMP) generation, analysis of
[125I]VIP-receptor complexes by cross-linking experiments, as well as developed
associated G proteins assayed by cholera and pertussis toxin-catalyzed ADP
ribosylation and Western blot. The Scatchard analysis of binding data was
consistent with the existence of two classes of VIP binding sites with K(d)
values unaltered and B(max) increased during postnatal development. The
efficiency of VIP stimulation of cAMP generation increased from 1-week-old rats
to adult conditions. The VIP-receptor complex apparent molecular mass (52-55 kDa)
remains unaltered, but it was significantly lower in 2-week-old than in 8-week
old rats. ADP-ribosylated material by cholera toxin (CTx) was higher from 8-week
old than from 2-week-old animals, while ADP-ribosylation by pertussis toxin (PTx)
was quantitatively higher in 8-week-old rats. Results were confirmed when
immunoblots for different G protein subunits were performed.
PMID- 10674989
TI - Retrovirus mediated gene transfer of the self antigen MBP into the bone marrow of
mice alters resistance to experimental autoimmune encephalomyelitis.
AB - Experimental autoimmune encephalomyelitis (EAE) is a prototypic model of organ
specific autoimmunity. MHC class II restricted T-cells directed against myelin
basic protein (MBP) have been shown to cause EAE in susceptible strains of mice.
We have asked whether the introduction of a gene encoding an autoantigen (MBP)
into the hematopoetic stem cells of mice would result in tolerance to that
protein. We have introduced cDNA encoding the 21.5 kDa isoform of MBP into the
hematopoetic stem cells of B10.PL (73NS), SJL, and B10 mice by retrovirus
mediated gene transfer. Our experiments show expression of proviral MBP in
peripheral blood and thymus following transplantation of genetically modified
stem cells. Such expression does not result in deletion of MBP-specific T cells
or tolerance to MBP, nor does it alter susceptibility to MBP-induced EAE in
susceptible strains B10.PL and SJL. However, retrovirus-mediated gene transfer
resulted in resistant B10 mice developing mild EAE. This report demonstrates that
autoreactive MBP-specific T cells can be selected in the presence of endogenous
antigen or an MBP-encoding retrovirus.
PMID- 10674990
TI - Antibody directed against mannan of the Mycobacterium tuberculosis cell envelope
provokes blood-brain barrier breakdown.
AB - Previous studies demonstrated that blood-brain barrier (BBB) breakdown observed
at the cerebral level during experimental allergic encephalomyelitis (EAE) arises
from the presence of Mycobacterium tuberculosis in Freund's adjuvant and not only
from the encephalitogenic antigens. The main objective of this study was to check
if the mannan moiety of lipoarabinomannan present in the mycobacterial cell
envelope is responsible for an immune response provoking a BBB breakdown. The
results showed that: firstly, the complete Freund's adjuvant (CFA) contains a
high release of polysaccharides; secondly, the rats immunized with the CFA
present important serum concentration of anti-mannan antibody; and finally, a
single 2-mg dose of anti-mannan antibody injected intravenously in naive rats
provokes an immediate and reversible BBB breakdown. These results suggest that
mannan arising from the solubilization of the mycobacterial cell wall in Freund's
adjuvant induces a high production of anti-mannan antibody, which, in turn,
provokes a BBB breakdown and possibly facilitates the induction of EAE.
PMID- 10674991
TI - Partial synergy of bisindolylmaleimide with apoptotic stimulus in antigen
specific T cells--implications for multiple sclerosis.
AB - In multiple sclerosis (MS), induction of T cell apoptosis constitutes a promising
therapeutic strategy. Recently, bisindolylmaleimide has been shown to be an
effective treatment of experimental autoimmune encephalomyelitis, presumably due
to enhancement of CD95-mediated T cell apoptosis. Therefore, we studied the
effects of bisindolylmaleimide on human (auto)antigen-specific T cells. We
observed a synergistic effect of bisindolylmaleimide with apoptotic stimulus
assessed via caspase activity and annexin V-binding, but no potentiation of DNA
fragmentation or cell death. Thus, bisindolylmaleimide might be useful for
modulating T cell apoptosis, yet more potent substances have to be generated re
establishing immunological control over auto-reactive T cells.
PMID- 10674992
TI - An alkali-soluble factor present in normal brain tissue inhibits antigen-specific
lymphocyte proliferation.
AB - The brain has long been recognized as an immune privileged site and probably
contains multiple immune regulatory factors. We have investigated the immune
regulatory properties of brain tissue on cultured lymphocytes. Homogenized brain
tissue inhibits proliferation to antigen, but stimulates proliferation in
response to most mitogens. The inhibitory activity is destroyed by treatment with
proteases or neuraminadase. The activity is in the insoluble fraction of the
homogenate, but becomes soluble in 0.04 M NaOH. After gel filtration
chromatography of the alkali soluble material, the suppressive activity is in the
high molecular weight fraction which contains protein and carbohydrate. The brain
homogenate blocks the effects of IL-2. The activity is not affected by
neutralizing antibodies against regulatory cytokines, does not depend on Fas or
FasL, and is not due to the presence of gangliosides. These data suggest that a
brain glycoprotein or proteoglycan which is either membrane-bound or part of the
extracellular matrix has immune regulatory effects in culture. The relevance of
these findings to immune regulation in the intact animal deserves further
investigation.
PMID- 10674993
TI - Chronic stress in caregivers of dementia patients is associated with reduced
lymphocyte sensitivity to glucocorticoids.
AB - Caring for the chronically ill is associated with chronic distress. In view of
the adverse effects of distress on cellular immune function, such distress may
have implications for health. Indeed, it has been proposed that the hypothalamic
pituitary-adrenal (HPA) axis is a potential psychobiological mediator of these
effects. In this study, we observed that elderly caregivers experienced greater
distress and increased salivary cortisol than non-caregivers. In addition,
caregivers had blunted mitogen-induced lymphocyte proliferation, lower mitogen
induced IL-2 production, and reduced lymphocyte sensitivity to glucocorticoids.
These results indicate that chronic distress is associated with impaired cell
mediated immunity which is, in turn, associated with elevated basal steroid
levels and altered steroid immunoregulation at the level of the lymphocyte.
PMID- 10674994
TI - Intrathecal release of sICAM-1 into CSF in neuroborreliosis--increased brain
derived fraction.
AB - In the present study, we report sICAM-1 concentration in the cerebrospinal fluid
(CSF) and serum of patients with neuroborreliosis (NB, n = 11), compared to the
data from a control group of patients with corresponding blood/CSF barrier
dysfunction but without inflammation in the central nervous system (disc prolaps,
DP, n = 11). In NB, the sICAM-1 concentration in CSF was increased up to six-fold
(ranges: 6.6-42.8 ng/ml and 2.2-9.8 ng/ml for NB and DP respectively) with no
change in serum sICAM-1. The corresponding sICAM-1 CSF/serum concentration
quotients (Q(ICAM)) were in the ranges: 22.5-171.3 X 10(-3), and 8.8-27.8 X 10(
3) for NB and DP respectively. This finding can be explained by increase of the
brain-derived fraction of sICAM-1 in NB. In one case we observed increased
Q(ICAM) on 6th day after admission to the hospital (171.3 X 10(-3) at the time of
the first lumbar puncture slightly increasing to 243.6 x 10(-3) five days later),
followed by normalization, in two remaining repunctured patients we observed
decreasing QICAM with normalizing Q(Alb).
PMID- 10674995
TI - Increased plasma levels of interleukin-1, interleukin-6 and alpha-1
antichymotrypsin in patients with Alzheimer's disease: peripheral inflammation or
signals from the brain?
AB - Plasma concentrations of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), C
reactive protein (CRP) and alpha-1-antichymotrypsin (ACT) in 145 patients with
probable Alzheimer's disease (AD) and 51 non-demented controls were measured. To
investigate the cellular activation of peripheral immune system, plasma levels of
neopterin were also investigated. Plasma levels of IL-1 were detectable in 17
patients with AD (13%) and only in one control (2%) and average levels of IL-1
were higher in AD patients than in controls (p < 0.001). IL-6 plasma levels were
detectable in a higher proportion of AD and controls (53% and 27%, respectively),
and were increased in patients with AD (p < 0.001). Plasma levels of ACT were
increased in patients with AD (p < 0.001) and CRP levels were in the normal
range. Plasma levels of neopterin were slightly lower in AD patients than in
controls, but differences were not statistically significant. No significant
correlation was observed between IL-1 and IL-6 levels or neopterin and cytokine
levels in plasma from AD patients. Plasma levels of ACT negatively correlated
with cognitive performances, as assessed by the mini mental state examination
(MMSE; R = -0.26, p < 0.02) and positively correlated with the global
deterioration state (GDS) of AD patients (R = 0.30, p < 0.007). Present findings
suggested that detectable levels of circulating cytokines and increased ACT might
not be derived by activation of peripheral immune system of AD patients.
Detection of these molecules might be used for monitoring the progression of
brain inflammation associated with AD.
PMID- 10674996
TI - Size-dependent retardation and resolution by electrophoresis of rigid, submicron
sized particles, using buffered solutions in presence of polymers: a review of
recent work from the authors' laboratory.
AB - Capillary zone electrophoresis (CZE) was conducted in buffered solutions of
polyacrylamide (PA) and polyethylene glycol (PEG) to find the degree and the
manner in which separation and resolution of submicron-sized rigid spherical
polystyrene sulfate and carboxylate particles were affected by the presence of
those polymers. In resolving pairs of representative particles, maximal
resolution was observed at or near the entanglement threshold concentration, c*,
of the polymer. The value of that maximum represents a several-fold increase in
resolution. Since c* can be calculated from intrinsic viscosity, and the latter
from the molecular weight of the polymer (and some constants available in the
literature), optimally resolving polymer conditions become predictable. The
maximum can also be experimentally determined by measuring intrinsic viscosity
and calculating c*, or by either systematically varying the concentration of a
polymer of constant molecular weight or by varying the molecular weight of a
polymer at constant concentration. An optimally resolving field strength is
superimposed on the maximally resolving condition of polymer concentration and
weight.
PMID- 10674997
TI - Characterization of two types of mitochondrial creatine kinase isolated from
normal human cardiac muscle and brain tissue.
AB - Two types of mitochondrial creatine kinase (Mi-CK), sarcomeric (sMi-) and
ubiquitous (uMi-)CKs, were isolated from normal human cardiac muscle and brain
tissue, respectively, and their heterogeneity was characterized by means of
isoelectric focusing (IEF). Octameric sMi-CK and uMi-CK were electrophoresed
cathodic to cytoplasmic muscle-type creatine kinase isoenzyme (CK-MM) and dimeric
Mi-CKs were found at the position of CK-MM on a cellulose acetate membrane. The
electrophoretic mobilities of sMi-CK were similar to those of uMi-CK. Octameric
sMi-CK was focused at pI 7.1-8.0 and dimeric forms at pI 6.55, 6.75, 6.85, and
6.95. New bands appearing at pI 6.65 and 6.75 after treatment of sMi-CK with
carboxypeptidase B were found to be delysined forms. sMi-CK reacted with anti-sMi
CK antibodies, and the immune complexes were focused at pI 5.8. The Km value of
sMi-CK for creatine phosphate (PCr) was 1.19 +/-0.20 mmol/L (mean +/- standard
error), the activation energy (Ea) was 108.3+/-1.2 kJ/ mol, and the residual
enzyme activity after heating at 45 degrees C for 20 min was 79.6+/-1.9%. On the
other hand, octameric uMi-CK was focused at pI 7.1-7.9 and the dimeric forms were
focused at pI 6.6, 6.7, 6.8, 6.9, and 7.0. Delysined forms were focused around pI
6.3, 6.4, 6.8, and 6.9. uMi-CK reacted with anti-sMi-CK antibodies, and the
immune complexes were focused at pI 5.8. The Km value of uMi-CK for PCr was
1.07+/-0.03 mmol/L, Ea of uMi-CK was 110.0+/-0.9 kJ/mol, and the residual enzyme
activity after heating at 45 degrees C for 20 min was 90.3+/-0.4%. The sMi-CK and
uMi-CK were hybridized and the hybrid Mi-CK appeared at pI 6.78, 6.98, and 7.1
7.95. The pIs of the hybrid Mi-CK were between those of sMi-CK and uMi-CK. As
described above, sMi-CK and uMi-CK were slightly different from each other with
respect to the pI and some enzyme characteristics.
PMID- 10674998
TI - Reduction of tyrosine-phosphorylated proteins in involuted thymuses of stressed
rats: a study using immunological methods.
AB - In the present study, we investigated whether tyrosine phosphorylation was
involved in thymic involution, which has been reported to correlate well with the
effects of various kinds of stresses. Immunohistochemistry using the anti
phosphotyrosine antibody showed that the immunoreactivity decreased remarkably in
the involuted thymus of stressed rats as compared with the control thymus.
Immunoblot analysis using the anti-phosphotyrosine antibody revealed the tyrosine
phosphorylated proteins with apparent molecular masses of 120, 90, and 70 kDa on
sodium dodecyl sulfate-polyacrylamide gel electrophoresis were detected in the
control thymus. The immunoreactive band corresponding to the three proteins
decreased remarkably in the involuted thymus. Further, we found by
immunoprecipitation experiments that the 120 kDa protein was p130cas, a crk
associated src substrate. These findings suggest that tyrosine phosphorylation
signaling may be involved in thymic involution.
PMID- 10674999
TI - Analysis of galectin 1-mediated cell signaling by combined precipitation and
electrophoresis techniques.
AB - Galectin-1 (GAL1) is a beta-galactoside-binding protein that has been implicated
in the regulation of viability of lymphoid cells. However, the signaling pathway
governed by the binding of GAL1 to the cell membrane is not understood yet. As a
first step toward the elucidation of GAL1-initiated signaling events,
electrophoresis techniques such as sodium dodecyl sulfate-polyacrylamide gel
electrophoresis (SDS-PAGE), and two-dimensional electrophoresis (2-DE) were used
together with precipitation techniques. This allowed us to identify the membrane
receptor of GAL1, and to characterize the signal resulting from the binding of
GAL1 to this receptor. Our results demonstrate that the tyrosine phosphatase CD45
is the receptor for GAL1, and that the src-type tyrosine kinase Lyn is a target
for the effects of GAL1/CD45 interactions in B-cells. Furthermore, these results
show the usefulness of combined precipitation and electrophoresis techniques to
analyze phosphotyrosine-dependent mechanisms during the study of cell functions.
PMID- 10675000
TI - Specific gel electrophoresis method detects two isoforms of human intestinal
alkaline phosphatase.
AB - We have demonstrated that the 6.0% polyacrylamide disc gel electrophoresis (PAGE)
method in the presence of 1% Triton X-100 clearly separated both normal molecular
mass intestinal alkaline phosphatase (NIAP) and bone alkaline phosphatase (BAP)
in serum regardless of the ABO blood group and the secretor status of the
subjects. From the results under the usual 7.5% PAGE condition, overlapping
mobilities of NIAP and BAP were found in particular in nonsecretor subjects after
a high-fat meal. Under the above conditions, the apparent BAP percentage three
hours after a meal was higher in nonsecretors than in subjects under fasting
conditions, because NIAP activity in serum rose sharply following a high-fat
meal. In contrast, under our 6.0% PAGE method, the NIAP and BAP were clearly
separated from each other regardless of whether the subjects were fasting or had
ingested a high-fat meal. In addition, an elevated level of the circulating NIAP
can be another marker for patients with liver cirrhosis. Considering all these
factors, the 6.0% PAGE method proposed by us is not only a useful method for the
separation of intestinal alkaline phosphatase (IAP) isoforms, but can also be
useful for the analysis of other usual AP isozymes.
PMID- 10675001
TI - The contribution of fructose and nitric oxide to oxidative stress in hamster
islet tumor (HIT) cells through the inactivation of glutathione peroxidase.
AB - Reducing sugars, such as glucose and fructose, are known to play a role in the
initiation of apoptosis in pancreatic beta-cells. The data collected in this
study show that fructose increases H2O2 levels and lipid peroxidation of hamster
islet tumor (HIT) cells, which originated from hamster pancreatic beta-cells. In
an attempt to clarify the mechanism of this oxidative stress, we were able to
show that glutathione peroxidase (GPx) is inactivated by fructose, and that mRNA
expression of GPx is suppressed by fructose. Nitric oxide (NO) is also known to
bring about apoptosis. The presence of NO increases intracellular peroxide levels
in HIT cells as judged by flow cytometric analysis. These data suggest that
fructose and nitric oxide suppress the activity or expression of GPx, and, as a
result, permit an increase in intracellular peroxides or lipid peroxidation. This
represents a major contribution to the main mechanism of apoptosis by fructose
and NO.
PMID- 10675002
TI - Two novel myogenic factors identified and isolated by sequential isoelectric
focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
AB - A number of environmental factors were used experimentally to enhance myogenesis
during muscle regeneration; however, many hormones and growth factors have been
shown to have the ability to increase the rate of satellite cell division, but
they only work on satellite cells that are already active in many animal
experiments. Recently, the crushed muscle extract (CME) of rats was found to be
able to trigger dormant adult rat satellite cells to re-enter the cell mytogenic
cycle; however, the identity of the active factors present in rat CME remains
unknown. In the present study, the CME was fractionated by the strategy of
sequential isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel
electrophoresis (SDS-PAGE) coupled with functional analysis by myoblast culture.
Two satellite cell-specific myogenic factors were identified and purified from
CME by this strategy. One of the factors has a molecular mass of around 7 kDa and
another about 39 kDa. The factor of 39 kDa could be retained in heparin-Sepharose
column and eluted with phosphate-buffered saline (PBS) containing 1 M NaCl, but
the 7 kDa factor did not bind to the heparin column. These two purified myogenic
factors could synergistically trigger the proliferation and differentiation of
dormant satellite cells, whose progenies subsequently fuse in vitro, or fuse to
pre-existing partially damaged muscle fibers to form full repair of the damaged
muscle fibers or to form new myotubes to replace the completely damaged muscle
fibers during the cascade of muscle healing and regeneration in vivo. The
identities of these two myogenic factors are under study.
PMID- 10675003
TI - Measurement of serum low density lipoprotein-cholesterol in patients with
hypertriglycemia.
AB - Low density lipoprotein-cholesterol (LDL-c) concentration measured by a
homogeneous enzymatic assay was reported to correlate well with the modified beta
quantification assay, especially in samples with high triglyceride (TG)
concentration. In this study, we evaluated a homogeneous enzymatic assay,
Cholestest-LDL assay system, in hypertriglycemic patient samples, and found that
56% (9/16) of serum samples with intermediate TG concentrations (2.27-4.52
mmol/L) showed more than 10% discrepancy with concentration by the modified beta
quantification assay. Such serum samples originated from patients with
hyperglycemia of type II a (three cases), type II b (two cases), type III (one
case), and type IV (six cases). Differential staining of cholesterol and
triglyceride after agarose gel electrophoresis revealed that these serum samples
contained significant amounts of intermediate fractions between pre-beta- and
beta-lipoproteins. Since lipoprotein (a), which migrates between pre-beta- and
beta-lipoproteins, is not correlated with the discrepancy, we believe the
intermediate fraction consists of intermediate density lipoprotein (IDL) and a
chylomicron remnant. A part of IDL and chylomicron remnant, which contain a
significant amount of triglyceride, might be measured as LDL-c by the homogeneous
enzymatic assay, but not by the modified beta-quantification assay.
PMID- 10675004
TI - Heat shock protein (hsp 70)-related epitopes are common allergenic determinants
for barley and corn antigens.
AB - IgE reactive components of barley and corn were compared using sodium dodecyl
sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotted with sera
from workers exposed to complex bioaerosols. The antibody made against Arabdopsis
heat shock protein (hsp 70) was used to identify those components equivalent to
hsp 70 in molecular size. Components with a molecular mass of 69 kDa and 33 kDa
were positively reacted, and immunoblots of two-dimensional polyacrylamide gel
electrophoresis were compared.
PMID- 10675005
TI - Covalent binding of polyethylene glycol to the surface of red blood cells as
detected and followed up by cell electrophoresis and rheological methods.
AB - Cyanuric chloride activated polyethylene glycol (PEG)-5000 was covalently coupled
to murine and human red blood cells (pegylated RBC). Our purpose was to
camouflage RBC receptors, which is necessary for parasite invasion, a process
essential to sustain parasitemia. Cell electrophoretic mobility analysis (CEM) of
pegylated RBC distinguished a new population of cells bearing characteristic CEM.
Pegylation of RBC also modified their rheological properties, which were
documented by evaluation of cell deformability (based on cell transit time
through calibrated micropores) and cell aggregation (as measured by ultrasonic
interferometry). Homologous transfusion of pegylated RBC into murine malaria
infected mice had no significant effect on the cerebral malaria death rate in
Plasmodium berghei-infected mice, but it reduced the peripheral blood parasitemia
by a factor 2 while in Plasmodium yoelii infected mice, the parasitemia was
dramatically reduced by a factor of 4. These experiments demonstrate that
transfusion of pegylated RBC may inhibit peripheral parasitemia. Cell
electrophoresis appears to be a useful tool to allow in vivo detection and to
investigate the fate of transfused pegylated RBC.
PMID- 10675006
TI - Blood compatibility of particulate carriers investigated by cell electrophoresis
and particle electrophoresis: a preliminary report.
AB - Polyethylene glycol (PEG) and dextran were covalently coupled, or only adsorbed,
to the surface of three kinds of inorganic particles in order to shield their
surface and reduce their nonspecific binding to red blood cells. Surface
modification as well as interaction of particles with red blood cells was
followed up by particle electrophoresis. This allowed a quick evaluation of the
efficiency of polymer coupling. Moreover, the nonspecific binding of particles to
red blood cells was easily investigated with cell electrophoresis, showing the
inhibitory effect of immobilized PEG-5000 or dextran. The electrophoretic
mobility analysis presented here may be used for screening blood compatibility of
particulate drug carriers and could be helpful in formulating long-living
circulating particles.
PMID- 10675007
TI - Mammalian pituitary growth hormone: applications of free flow electrophoresis.
AB - We have used free flow electrophoresis (FFE) technology to study the
electrophoretic behavior of growth hormone (GH) molecules, GH secretory granules
and GH cell subpopulations contained in pituitary glands of humans and rodents.
GH activities in different electrophoresis fractions were measured by immunoassay
or bioassay, viz., measurement of chondrocyte proliferation in the tibial growth
plate of the hypophysectomized rat. Using FFE we discovered a peptide in human
post mortem pituitary tissue and cryopoor human plasma that is active in the
tibial line bioassay, is inactive in a GH immunoassay, and is neither GH nor a GH
fragment. This peptide, called tibial peptide, has high anodal mobility and is
readily separable from GH by FFE. Its molecular mass is approximately 5 kD. It is
particularly rich in glycine. A partial amino acid sequence (residues 9-25) in
the middle region of the peptide shows that 9 of the 16 residues are nonpolar. On
the basis of results from other FFE experiments, using either GH-containing
secretory granules or GH-producing cells, we believe that the peptide is stored
within the secretion granule of a subpopulation of GH cells. On the basis of
recent information elucidating the role of C peptide contained in the insulin
storage granule of the pancreatic cell, we propose that the tibial peptide serves
a similar role in the GH cell. Thus, not only may tibial peptide aid in proper
alignment of disulfide bonds between GH monomers in the secretory granule, but,
like the C peptide, it also appears to have biologic activity in its own right.
PMID- 10675008
TI - Multistage electrophoresis system for the separation of cells, particles and
solutes.
AB - It is common to operate equilibrium-based separation methods, such as
distillation and extraction, as multistage unit operations, in which equilibrium
is presumably achieved within each stage. Two rate-based separation processes,
free electrophoresis and magnetic particle separation, have now been operated in
multistage mode. Preparative free electrophoresis of particles and solutes has
resisted scale-up and is confined to a narrow range of ionic compositions.
Natural convection induced in electrophoresis buffers by Ohmic heating has been a
strong deterrent and has led to such measures as radial electrophoresis in
Couette flow, free-flow electrophoresis, low-gravity electrophoresis, density
gradient electrophoresis, and reorienting density gradient electrophoresis, to
name a few. The short vertical electrophoresis path exploited in the last
mentioned forms the basis for multistage electrophoresis. A thin-layer
countercurrent distribution apparatus was designed and constructed so that up to
20 fractions could be collected on the basis of electrophoretic mobility by
applying an electric field. The mixture to be separated starts in a bottom
cavity, and successive top cavities collect fractions as separand particles or
molecules are electrophoresed upward out of the bottom cavity. Mathematical
models of this process were developed, and experiments were performed to verify
the predictions of the models by collecting and counting particles in each cavity
after fractionation.
PMID- 10675009
TI - Application of binary buffer systems to free flow cell electrophoresis.
AB - The applicability of free flow electrophoresis (FFE) was expanded towards
processing of sensitive cells. The chamber medium was adjusted to a physiologic
pH of 7.35 by a mixture of N-(2-hydroxyethyl)piperazine-N'-(3-propanesulfonic
acid) (EPPS) and 2,2-bis(hydroxymethyl)-2,2'2"-nitrilotriethanol (BISTRIS). These
substances proved to be nontoxic to sensitive cells such as human smooth muscle
or thyroid cells. They enhanced the electrical conductivity of the medium only
slightly so that a new cell electrophoresis separation medium could be prepared,
which contained 30 mM NaCl together with or without 1 mM CaCl2 but did not
generate problems of overheating the fluid. Suspended in this medium, human
smooth muscle cells as well as human thyroid carcinoma cells remained viable
single cells for at least 120 min. After this period they could be recultured to
form monolayers. If electrophoresed in the Octopus preparative FFE device, they
migrated as single cells and did not clot; therefore, their electrophoretic
behavior could be determined exactly.
PMID- 10675010
TI - The role of DNA hypermethylation in human neoplasia.
AB - Cancer development and progression is dictated by a series of alterations in
genes such as oncogenes, tumor suppressor genes, DNA repair genes, and others.
DNA methylation is an epigenetic modification that is profoundly altered in most
cancers. Recently, hypermethylation of CpG-rich areas located in the promoter of
genes (CpG islands) has been shown to be commonly implicated in silencing tumor
suppressor genes in cancer. By cloning and characterizing a large number of such
CpG islands hypermethylated in colon cancer, we found that two processes explain
most of these events. Age-related CpG island methylation in a subset of cells in
normal tissues, followed by intensification of methylation in cancer cells
explains the majority of hypermethylation events in colon cancer and may provide
a mechanistic link between aging and cancer formation. Most of the other CpG
islands methylated in colon cancer can be explained by a newly described
phenotype, the CpG island methylator phenotype (CIMP) which results in multiple
methylation events in a subset of cancers. CIMP accounts for the majority of
sporadic colon cancers characterized by microsatellite instability, as well as
most tumors with k-ras mutations. Understanding further the factors that lead to,
and modulate, aberrant methylation in cancer may provide novel avenues for
prevention and treatment of this disease.
PMID- 10675011
TI - Application of electrophoresis technology to DNA analysis.
AB - We used the variable number tandem repeat (VNTR) polymorphism and the ten short
tandem repeat (STR) polymorphisms to study a number of disputed paternity cases
in the Japanese population. For the determination of VNTR locus (D1S80) and the
ten STR loci (vWA, F13B, TH01, TPOX, CSF1PO, F13A01, LPL, D3S1744, D12S1090,
D18S849) we used polymerase chain reaction (PCR) amplification and the vertical
polyacrylamide gel electrophoresis technique followed by SYBR green I staining.
The irregular repeats were analyzed by sequencing from bands of vertical
polyacrylamide gel electrophoresis using the latest gene analyzing equipment, the
ABI PRISM 310 Genetic Analyzer. The probable genotypes of the deceased putative
father were deduced by Komatu's method from the genotypes of the widow and the
genotypes of their children. The calculation of paternity probability used the
Essen-Moller formula and Bayes's theorem. Calculated in eleven loci, the
distinguishing probabilities (DP) and the mean exclusion chance (MEC) were 0.9999
and 0.9989, respectively. Therefore, information obtained from eleven DNA
polymorphisms is enough to determine paternity plausibility.
PMID- 10675012
TI - Regulation of macrophage-specific gene expression by degenerated lipoproteins.
AB - The effect of aggregated low-density lipoprotein (agLDL) on cell viability and
macrophage-specific gene expression using human peripheral blood monocytes in
culture was investigated. AgLDL suppressed activation-induced cell death of
phorbol ester-treated macrophages. The inhibition of apoptosis was accompanied by
downregulation of apoptosis-promoting proteases, including interleukin-1beta
converting enzyme (ICE) and CPP32 and upregulation of anti-apoptotic cytokine
(interleukin-1beta (IL-1beta)). In contrast, macrophage-colony stimulating factor
(M-CSF) enhanced cell death of lipid-bearing macrophages, suggesting that the
anti-atherogenic action of M-CSF is at least in part mediated through apoptotic
elimination of macrophages. Then, we attempted to isolate the genes specifically
induced by agLDL in macrophages using a subtraction-based cloning strategy. One
of the genes isolated, termed LIG (LDL-inducible gene), encodes a human homolog
of E2 ubiquitin-conjugating enzyme. Ubiquitination of multiple intracellular
proteins was observed in agLDL-treated macrophages, which coincided with
upregulation of LIG. These results suggest that LIG acts as a direct mediator of
foam cell formation through polyubiquitination and subsequent degradation of
cellular proteins with apoptosis-inducing properties. The regulation of apoptosis
by macrophage-specific gene expression may contribute to foam cell formation and
atherosclerosis.
PMID- 10675013
TI - Short tandem repeat analysis in Japanese population.
AB - Short tandem repeats (STRs), known as microsatellites, are one of the most
informative genetic markers for characterizing biological materials. Because of
the relatively small size of STR alleles (generally 100-350 nucleotides),
amplification by polymerase chain reaction (PCR) is relatively easy, affording a
high sensitivity of detection. In addition, STR loci can be amplified
simultaneously in a multiplex PCR. Thus, substantial information can be obtained
in a single analysis with the benefits of using less template DNA, reducing
labor, and reducing the contamination. We investigated 14 STR loci in a Japanese
population living in Sendai by three multiplex PCR kits, GenePrint PowerPlex 1.1
and 2.2. Fluorescent STR System (Promega, Madison, WI, USA) and AmpF/STR Profiler
(Perkin-Elmer, Norwalk, CT, USA). Genomic DNA was extracted using sodium dodecyl
sulfate (SDS) proteinase K or Chelex 100 treatment followed by the
phenol/chloroform extraction. PCR was performed according to the manufacturer's
protocols. Electrophoresis was carried out on an ABI 377 sequencer and the
alleles were determined by GeneScan 2.0.2 software (Perkin-Elmer). In 14 STRs
loci, statistical parameters indicated a relatively high rate, and no significant
deviation from Hardy-Weinberg equilibrium was detected. We apply this STR system
to paternity testing and forensic casework, e.g., personal identification in rape
cases. This system is an effective tool in the forensic sciences to obtain
information on individual identification.
PMID- 10675014
TI - Phylogenetic analysis of picoplankton in Lake Biwa and application to legal
medicine.
AB - Three strains of picoplankton designated as brown, green, and pink belonging to
the Synechococcus genus in cyanobacteria (approximately 1 microm in size) are
found ubiquitously in Lake Biwa, Japan. However, they could not be
morphologically discriminated from other bacteria such as Proteobacteria and
Bacillus by microscopy. In this study, we attempted to use the polymerase chain
reaction (PCR) analysis of the 16S ribosomal DNA (rDNA) from picoplankton for the
diagnosis of death by drowning. A segment of 16S rDNA was sequenced in order to
investigate their phylogenetic relationships and to design the specific primers.
The PCR products from three picoplanktons were compared with those from five
other cyanobacteria, Melosira (diatom), Staurastrum (green alga), bacteria from
Lake Baikal, and humans. The picogram order of template DNA from picoplankton was
specifically amplified by the primers. When the template of picoplankton was
mixed with human tissue, at least 10 ng of template DNA was needed to obtain a
PCR product. The efficiency of PCR was increased more than hundredfold by
isolating the picoplankton from human lung tissue. The specific PCR products of
the picoplankton were obtained from a formalin-fixed drowning body (lung and
liver) that was found in a downstream river and Lake Biwa. The PCR analysis of
the picoplanktion 16S rDNA is considered useful for the diagnosis of death by
drowning.
PMID- 10675015
TI - Large volume sample stacking of positively chargeable analytes in capillary zone
electrophoresis without polarity switching: use of low reversed electroosmotic
flow induced by a cationic surfactant at acidic pH.
AB - A simple and effective way to improve detection sensitivity of positively
chargeable analytes in capillary zone electrophoresis more than 100-fold is
described. Cationic species were made to migrate toward the cathode even under
reversed electroosmotic flow caused by a cationic surfactant by using a low pH
run buffer. For the first time, with such a configuration, large volume sample
stacking of cationic analytes is achieved without a polarity-switching step and
loss of efficiency. Samples are prepared in water or aqueous acetonitrile.
Aromatic amines and a variety of drugs were concentrated using background
solutions containing phosphoric acid and cetyltrimethylammonium bromide.
Qualitative and quantitative aspects are also investigated.
PMID- 10675016
TI - Electropherogram of capillary zone electrophoresis with effective mobility axis
as a transverse axis and its analytical utility. I. Transformation applying the
hypothetical electroosmotic flow.
AB - For capillary zone electrophoresis, a new method of transformation from migration
time to effective mobility was proposed, in which the mobility increase due to
Joule heating and the relaxation effect of the potential gradient were eliminated
successfully. The precision of the mobility evaluated by the proposed
transformation was discussed in relation to the analysis of rare earth ions. By
using the transformation, almost the same pherograms could be obtained even from
the pherograms obtained originally at different applied voltages.
PMID- 10675017
TI - Automated DNA fragment collection by capillary array gel electrophoresis in
search of differentially expressed genes.
AB - An automatic DNA fragment collector using capillary array gel electrophoresis has
been developed. A sheath flow technique is used for not only detection but also
collection of DNA fragments. In a sheath flow cell, the DNA fragments separated
by 16 capillaries flow independently into corresponding sampling capillaries. The
fraction collector consists of 16 sampling trays and each sampling tray is set
beneath each end of the sampling capillaries to collect the flow-through DNA
fragments. Certain DNA fragments are automatically sorted by controlling the
movement of the sampling trays according to the signals from the system. The
collector experimentally separated two mixtures of polymerase chain reaction
(PCR) products: one prepared by using eight different sizes (base lengths from
161 to 562) of DNAs; and the other prepared by a differential display (DD) method
with cDNA fragments. Collected DNA fragments are amplified by PCR and measured by
electrophoresis. DNA fragments with base length differences of one (base lengths
363 and 364) were successfully separated. A separated DNA fragment from the DD
sample was also successfully sequenced. In addition, differentially expressed DNA
fragments were automatically sorted by comparative analysis, in which two similar
cDNA fragment groups, labeled by two different fluorophores, respectively, were
analyzed in the same gel-filled capillary. These results show that the automatic
DNA fragment collector is useful for gene hunting in research fields such as drug
discovery and DNA diagnostics.
PMID- 10675018
TI - Fluorescence-based single-strand conformation polymorphism analysis of mutations
by capillary electrophoresis.
AB - Capillary electrophoresis in combination with fluorescence-based single-strand
conformation polymorphism (SSCP) analysis was used to screen for known mutations
as well as for unknown mutations. The mutations causing hemochromatosis and
thrombogenetic diseases (factor V Leiden mutation and prothrombin mutation) are
well defined. Familial hypercholesterolemia is caused by mutations in the low
density lipoprotein (LDL) receptor gene. Because the mutations are
heterogeneously localized in all 18 exons of the LDL receptor gene, effective
screening procedures are necessary. The three well known mutations and 59 of 61
previously characterized mutations in the LDL receptor gene were detected by a
distinct abnormal fragment pattern in capillary electrophoresis. The remaining
two mutations in the LDL receptor gene showed only slight abnormalities under
standard electrophoresis conditions (13 kV, 30 degrees C, 30 min). However, the
abnormal pattern could be amplified by increasing the electrophoresis
temperature. In all cases, heterozygous and homozygous mutations could clearly be
differentiated from wild-type alleles. Because of the high efficiency of mutation
detection, capillary electrophoresis in combination with fluorescence-based SSCP
analysis would be attractive for the detection of well-defined mutations as well
as for the screening of unknown mutations. The accuracy and the degree of
automation make this technique well suited for routine genetic diagnosis.
PMID- 10675019
TI - Confirmation testing of amphetamines and designer drugs in human urine by
capillary electrophoresis-ion trap mass spectrometry.
AB - Monitoring of amphetamines and designer drugs in human urine is a timely topic in
clinical toxicology, surveillance of drug substitution, forensic science, drug
testing at the workplace, and doping control. Confirmation testing of urinary
amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy)
and 3,4-methylenedioxyamphetamine (MDA) by capillary electrophoresis (CE)
combined with atmospheric pressure electrospray ionization and ion trap mass
spectrometry (MS) is described. Using an aqueous pH 4.6 buffer composed of
ammonium acetate/acetic acid, CE-MS and CE-MS2 provided data that permitted the
unambiguous confirmation of these drugs in external quality control urines.
Furthermore, other drugs of abuse present in alkaline urinary extracts, including
methadone and morphine, could also be monitored. The data presented illustrate
that the sensitivity achieved with the benchtop MS is comparable to that observed
by CE with UV absorption detection. CE-MS2 is further shown to be capable of
identifying comigrating compounds, including the comigration of amphetamine with
nicotine.
PMID- 10675020
TI - Simultaneous determination of bromide, nitrite and nitrate ions in seawater by
capillary zone electrophoresis using artificial seawater as the carrier solution.
AB - We describe capillary zone electrophoresis (CZE) for the simultaneous
determination of bromide, nitrite and nitrate ions in seawater. Artificial
seawater was adopted as the carrier solution to eliminate the interference of
high concentrations of salts in seawater. The artificial seawater was free from
bromide ion to enable the determination of bromide ion in a sample solution. For
the purpose of reversing the electroosmotic flow (EOF), 3 mM
cetyltrimethylammonium chloride (CTAC) was added to the carrier solution. A 100
microm ID (inside diameter) capillary was used to extend the optical path length.
The limits of detection (LODs) for bromide, nitrite, and nitrate ions were 0.46,
0.072, and 0.042 mg/L (as nitrogen), respectively. The LODs were obtained at a
signal to noise ratio (S/N) of 3. The values of the relative standard deviation
(RSD) of peak area for these ions were 1.1, 1.5, and 0.97%. The RSDs of migration
time for these ions were 0.61, 0.69, and 0.66%. Artificial seawater samples
containing various concentrations of bromide, nitrite, and nitrate ions were
analyzed by the method. The error was less than +/-12% even if the concentration
ratio of bromide ion to nitrite or nitrate ion was 20-240. The proposed method
was applied to the determination of bromide, nitrite, and nitrate ions in
seawater samples taken from the surface and the seabed. These ions in other
environmental waters such as river water and rainwater samples were also
determined by ion chromatography (IC) as well as this method.
PMID- 10675021
TI - Capillary zone electrophoresis of albumin-depleted human serum using a linear
polyacrylamide-coated capillary: separation of serum alpha-and beta-globulins
into individual components.
AB - The separation of human serum globulins into individual components was
investigated by capillary zone electrophoresis (CZE) using a linear
polyacrylamide-coated capillary at pH 7.4. Prior to CZE analysis of globulin
components present in serum, it was found that it was necessary to remove
albumin. Preparation of albumin-depleted human serum with a HiTrap Blue column
allowed the detection of alpha- and beta-globulin components as a series of
peaks. Almost all the peaks, both narrow and broad, observed in CZE analysis
could be assigned to six globulin components (alpha1-acid-glycoprotein, alpha1
antitrypsin, haptoglobin, alpha2-macroglobulin, Gc-globulin, and transferrin) by
using the technique of antibody-based indirect detection. The CZE results,
obtained from serum preparations from three healthy adults and six patients,
showed that the CZE system might be capable of detecting qualitative differences
among individuals with regard to individual globulin components.
PMID- 10675022
TI - Capillary electrophoresis for determination of free and albumin-bound bilirubin
and the investigation of drug interaction with bilirubin-bound albumin.
AB - Capillary electrophoresis (CE) is a promising technique for assessment of free
bilirubin and its interaction with albumin, as it requires only a small sample
volume and provides a rapid and efficient separation of free bilirubin from its
albumin-bound complex in a one-phase system. In order to maintain the equilibrium
without dissociation of bilirubin from the albumin/bilirubin complex as in real
clinical conditions, the coupling of CE with frontal analysis (FA) was
investigated. A very large sample plug was introduced hydrodynamically into the
capillary (36 cm length, 50 microm inner diameter) at 15 psi x s to develop the
frontal conditions during CE separation. The working conditions for CE/FA
separation of bilirubin and albumin were optimized as follows: +20 kV; running
buffer, 10 mmol/L phosphate and 1 mmol/L ethylenediaminetetraacetic acid (EDTA),
pH 7.4. The working range for bilirubin was found to vary from 5 to 206
micromol/L; precision with relative standard deviation (RSD) <2.0% for n = 3 and
detection limit (signal to noise, S/N = 2) was 2 micromol/L. The residual binding
capacity of a simulated cord blood serum for bilirubin was 26 mg/100 mL at pH
7.4. Bilirubin was shown to be displaced from albumin when aspirin was added. The
free bilirubin concentration was found to increase to clinical significant
concentrations from 11.9 to 21.1% when increasing aspirin was added in the range
of 5-50 mg/100 mL, respectively. Thus, the investigation of aspirin displacement
of bilirubin from albumin is clinically important and the CE/ FA method is a
suitable procedure for this purpose.
PMID- 10675023
TI - Two-dimensional map of the proteome of Haemophilus influenzae.
AB - We have constructed a two-dimensional database of the proteome of Haemophilus
influenzae, a bacterium of medical interest of which the complete genome,
comprising about 1742 open reading frames, has been sequenced. The soluble
protein fraction of the microorganism was analyzed by two-dimensional
electrophoresis, using immobilized pH gradient strips of various pH regions, gels
with different acrylamide concentrations and buffers with different trailing
ions. In order to visualize low-copy-number gene products, we employed a series
of protein extraction and sample application approaches and several
chromatographic steps, including heparin chromatography, chromatofocusing and
hydrophobic interaction chromatography. We have also analyzed the cell envelope
bound protein fraction using either immobilized pH gradient strips or a two
detergent system with a cationic detergent in the first and an anionic detergent
in the second-dimensional separation. Different proteins (502) were identified by
matrix-assisted laser desorption/ionization mass spectrometry and amino acid
composition analysis. This is at present one of the largest two-dimensional
proteome databases.
PMID- 10675024
TI - Mass spectrometric approaches for the characterization of proteins on a hybrid
quadrupole time-of-flight (Q-TOF) mass spectrometer.
AB - This study demonstrates structural and conformational characterization of
proteins by nanoflow electrospray ionization (nanoESI) mass spectrometry (MS) and
tandem mass spectrometry (MS/MS) utilizing a quadrupole time-of-flight (Q-TOF)
mass spectrometer (Micromass, Manchester, England). Model peptides were
successfully sequenced at the 35 attomole (amol) level, and peptides derived from
a tryptic in-gel digest of 25 femtomole (fmol) bovine serum albumin (BSA) were
successfully sequenced. The results demonstrated that the MS/MS sensitivity of
the Q-TOF clearly surpassed the detection limit of the silver stain. A silver
destaining step greatly improved the mass analysis of peptides derived from in
gel digests. Interestingly, sequence analysis revealed BSA residue 424 (tyrosine)
as a potential chlorination site. In addition, a modified procedure was
successfully used to extract and measure the masses of two-dimensional
polyacrylamide gel electrophoresis (2-D PAGE)-resolved proteins in the 10-68.5
kDa range. The Q-TOF was also used to monitor conformational changes of proteins.
These experiments demonstrated an acid-induced denaturation of BSA in the pH 3-4
range, and heat-induced unfolding of cytochrome c between 50 and 60 degrees C.
Finally, Zn2+ binding was demonstrated for the carbonic anhydrase apoprotein. In
summary, the wide range of applications and the high quality of the experimental
data made the Q-TOF mass spectrometer a powerful analytical tool for protein
characterization.
PMID- 10675025
TI - Two-dimensional gel electrophoresis using immobilized pH gradient tube gels.
AB - An apparatus for the preparation of gels for immobilized pH gradient isoelectric
focusing (IPG) in glass tubes was developed. Using this apparatus, the highly
reproducible immobilized pH gradient can be formed with Immobilines in
polyacrylamide gels, and IPG gels at all possible pH ranges can be easily
prepared at low cost. The IPG tube gels in the first dimension in two-dimensional
gel electrophoresis was used to separate and identify a number of rice embryo
proteins in the proteome analysis. There was no difference in resolution of
proteins between the tube gels and the commercially available slab gels; after
electrophoresis, however, we could efficiently obtain a larger amount of the
purified proteins from the tube gels than from the slab gels.
PMID- 10675026
TI - Agarose isoelectric focusing for the detection of many isoforms and high
molecules in muscle protein analysis.
AB - Two-dimensional gel electrophoresis with agarose in the first dimension was
established. The technique was reported previously and was now much improved
without changing the basic procedure, presenting "a protein map" of chicken
skeletal muscle, including almost all components such as myosin heavy chains (200
kDa) and dystrofin (400 kDa). Application of this technique for the analysis of
all components was also successful with the liver and lens. Since large molecules
can get into the agarose in the first dimension, the study on protein interaction
was also reported with troponin components as a model system.
PMID- 10675027
TI - Involvement of protein kinase C epsilon in thyrotropin-releasing hormone
stimulated phosphorylation of the myristoylated alanine-rich C kinase substrate
in rat pituitary clonal cells.
AB - We have shown previously that novel protein kinase Cepsilon (nPKCepsilon) plays a
key role in the basal and thyrotropin-releasing hormone (TRH)-stimulated
prolactin (PRL) secretion in rat pituitary GH4C1 cells (Akita et al., J. Biol.
Chem. 1994, 269, 4653-4660). Here we examined the region downstream of
nPKCepsilon activation in order to understand the molecular mechanism by which
nPKCepsilon mediates TRH-induced signal transduction. Exposure of GH4C1 cells to
TRH causes a stimulation of the phosphorylation of a p80 (Mr approximately 80
000, pI approximately 4.3) and two p19 (p19a and b; Mr approximately 19 000, pI
approximately 5.6 and 5.5, respectively). Phorbol ester, a potent activator of
protein kinase C (PKC), also enhances these phosphorylations, whereas
bisindolylmaleimide I, a specific inhibitor of PKC, clearly inhibits the
phosphorylation of p80. p80 and p19 were identified as myristoylated alanine-rich
C kinase substrate (MARCKS) and stathmin, respectively, as assessed by their two
dimensional gel electrophoretic profiles and their stabilities to heat and acid
treatment. In nPKCepsilon-overexpressing stable clones, the phosphorylated level
of MARCKS but not stathmin was high in the resting state, and enhanced and
sustained upon TRH stimulation, correlating with the increased activation of
nPKCepsilon. TRH stimulates the release of MARCKS from the membrane/cytoskeletal
fraction to the cytosol fraction. These results, taken together with previous
data concerning PRL secretion, suggest that MARCKS, a regulatory component of the
cytoskeletal architecture, is the major substrate of nPKCepsilon in vivo, and
that its phosphorylation may regulate TRH-stimulated PRL secretion.
PMID- 10675028
TI - Proteomic approach to the identification of cell membrane proteins.
AB - The expression of plasma membrane proteins in human monocyte-derived U937 cells
was examined by cell disruption and isolation of microsomal fractions. Two
alternative procedures for cell disruption, Dounce homogenization and nitrogen
cavitation, were compared. Cell homogenization and sequential centrifugation
resulted in an approximately fivefold enrichment of plasma membrane proteins in
the microsomal fraction. However, identification of 30 such apparently enriched
proteins by two-dimensional (2-D) electrophoresis, proteolytic digestion, and
mass spectrometry revealed that only eight were plasma membrane proteins, the
remaining 22 being contaminants. In contrast, nitrogen cavitation followed by
sequential centrifugation and solubilization of proteins with sodium dodecyl
sulfate (SDS) and 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate
(CHAPS) detergent yielded subcellular fractions, including microsomes, that
showed little overlap in constituent proteins as revealed by 2-D electrophoresis.
These results highlight the importance of obtaining pure plasma membranes and
complete solubilization of membrane proteins for proteomic analysis.
PMID- 10675029
TI - Age-related changes of aqueous protein profiles in rat fast and slow twitch
skeletal muscles.
AB - Two-dimensional electrophoresis was used to generate the aqueous protein
expression patterns of rat extensor digitorum longus muscle (EDL, fast twitch
muscle) and solues muscle (SOL, slow twitch muscle) of different ages. Two
specific protein spots, S1 and S3, were identified from EDL muscles at the ages
of 12 and 18 months onward respectively. In the EDL muscles of aged rat (24
months) after intensive exercise training, S3 was still detected while S1
disappeared. In addition, diaphragm muscle (DIA, fast twitch muscle), which
retains physically active throughout the life span, was used as nondisuse
control. The results showed that the expressions of S1 and S3 in 24-month DIA
muscle were identical with the trained aged EDL muscle. It is suggested that
exercise might delay the onset of S1 expression. However, the expression of S3
over age seemed to be progressive and exercise independent. Another protein spot,
S2 was identified to express only in young EDL and SOL muscles, but its
expression decreased over age. Furthermore, exercise has no effect on S2
expression since S2 could not be detected in aged DIA as well as trained aged EDL
and SOL muscles. These results indicated that aqueous protein expression patterns
of skeletal muscle undergo changes during aging. Some of these changes such as S2
and S3 appear progressively, and some such as S1 could be delayed by exercise. S3
was identified as ubiquitin, which might play an important role in protein
degradation during skeletal muscle aging process.
PMID- 10675030
TI - Damage recognition in nucleotide excision repair of DNA.
AB - Nucleotide excision repair (NER) is found throughout nature, in eubacteria,
eukaryotes and archaea. In human cells it is the main pathway for the removal of
damage caused by UV light, but it also acts on a wide variety of other bulky
helix-distorting lesions caused by chemical mutagens. An ongoing challenge is to
understand how a site of DNA damage is located during NER and distinguished from
non-damaged sites. This article reviews information on damage recognition in
mammalian cells and the bacterium Escherichia coli. In mammalian cells the XPC
hHR23B, XPA, RPA and TFIIH factors may all have a role in damage recognition. XPC
hHR23B has the strongest affinity for damaged DNA in some assays, as does the
similar budding yeast complex Rad4-Rad23. There is current discussion as to
whether XPC or XPA acts first in the repair process to recognise damage or
distortions. TFIIH may play a role in distinguishing the damaged strand from the
non-damaged one, if translocation along a DNA strand by the TFIIH DNA helicases
is interrupted by encountering a lesion. The recognition and incision steps of
human NER use 15 to 18 polypeptides, whereas E. coli requires only three proteins
to obtain a similar result. Despite this, many remarkable similarities in the NER
mechanism have emerged between eukaryotes and bacteria. These include use of a
distortion-recognition factor, a strand separating helicase to create an open
preincision complex, participation of structure-specific endonucleases and the
lack of a need for certain factors when a region containing damage is already
sufficiently distorted.
PMID- 10675031
TI - Stable and full rescue of the pigmentation in a medaka albino mutant by transfer
of a 17 kb genomic clone containing the medaka tyrosinase gene.
AB - In the medaka Oryzias latipes, several albino strains have mutations in the
tyrosinase gene that have been fully characterized at the molecular level. A
genomic clone from wild-type medaka containing the 5 kb tyrosinase gene with its
five exons, 10 kb of upstream sequences and 2 kb downstream sequences was
introduced into fertilized eggs from a tyrosinase-negative albino strain. We show
that the injection of this genomic clone predominantly conferred mosaic
expression ending before the hatching stage. A minority of juveniles retained a
variable number of pigmented cells, including four individuals keeping one
pigmented eye through adulthood. Two of these could be mated, and one of these
transmitted the transgene resulting in complete rescue of pigmentation to 16% of
its offspring. The resulting transgenic line harbors a single copy of the wild
type tyrosinase gene and all fish are wild-type with respect to pigmentation.
These experiments suggest that the tyrosinase genomic clone, or a future shorter
version of it, can be used in fish to routinely detect transgenic lines. The
apparent faithful and systematic expression of the tyrosinase transgene is most
probably due to the presence of a locus control region (LCR) in the injected
clone.
PMID- 10675032
TI - Identification and cloning of an aspartyl proteinase from Coccidioides immitis.
AB - A 45 kDa protein was isolated from a soluble vaccine prepared from formaldehyde
killed spherules of Coccidioides immitis. From the N-terminal amino acid
sequence, the protein yielded a 17-amino-acid peptide that was homologous to
sequences of other fungal aspartyl proteinases. The coccidioidal cDNA encoding
the proteinase was amplified using oligonucleotide primers designed from the 45
kDa N-terminal amino acid sequence and a fungal aspartyl proteinase consensus
amino acid sequence. The PCR product was cloned and sequenced, and the remaining
5' upstream and 3' downstream cDNA was amplified, cloned, and sequenced. The cDNA
encoding the coccidioidal aspartyl proteinase open reading frame was cloned and
the fusion protein containing a C-terminal His-tag expressed in E. coli. The
recombinant aspartyl proteinase was purified by immobilized metal affinity
chromatography. This recombinant protein will be used for further studies to
evaluate its antigenicity, including protective immunogenicity.
PMID- 10675033
TI - Temperature-dependent sex determination in the American alligator: expression of
SF1, WT1 and DAX1 during gonadogenesis.
AB - Sex determination in mammals and birds is chromosomal, while in many reptiles sex
determination is temperature dependent. Morphological development of the gonads
in these systems is conserved, suggesting that many of the genes involved in
gonad development are also conserved. The genes SF1, WT1 and DAX1 play various
roles in the mammalian testis-determining pathway. SF1 and WT1 are thought to
interact to cause male-specific gene expression during testis development, while
DAX1 is believed to inhibit this male-specific gene expression. We have cloned
SF1 and DAX1 from the American alligator, a species with temperature-dependent
sex determination (TSD). SF1, DAX1 and WT1 are expressed in the urogenital
system/gonad throughout the period of alligator gonadogenesis which is
temperature sensitive. SF1 appears to be expressed at a higher level in females
than in males. This SF1 expression pattern is concordant with the observed
pattern during chicken gonadogenesis, but opposite to that observed during mouse
gonadogenesis. Although the observed sexual dimorphism of gonadal SF1 expression
in alligators and chickens is opposite that observed in the mouse, it is probable
that SF1 is involved in control of gonadal steroidogenesis in all these
vertebrates. DAX1 and WT1 are both expressed during stages 22-25 of both males
and females. However, there appear to be no sex differences in the expression
patterns of these genes. We conclude that DAX1, WT1 and SF1 may be involved in
gonadal development of the alligator. These genes may form part of a gonadal
development pathway which has been conserved through vertebrate evolution.
PMID- 10675034
TI - Organization of the mouse ASGR1 gene encoding the major subunit of the hepatic
asialoglycoprotein receptor.
AB - The hepatic asialoglycoprotein receptor was the first of the mammalian lectins to
be recognized and has been the subject of intense investigation for three
decades. Yet, the precise biological role of this major hepatic endocytic
receptor has remained elusive. We describe here the characterization of the mouse
gene for the major subunit of this receptor (ASGR1) along with 3.5 kb of the
upstream 5' region. The gene comprises eight coding exons, with the major
transcript in liver displaying a single non-coding 5' exon. A minor hepatic
transcript initiates 435 bp upstream of the major start and includes an
additional 5' non-coding exon and intron. A minimal 600 bp proximal region of
ASGR1 exhibits hepatic-specific promoter activity in HepG2 cells in vitro. These
results provide the basis for more detailed genetic studies on the functional
role of the hepatic asialoglycoprotein receptor in mammals.
PMID- 10675035
TI - Evolutionary conservation of the apolipoprotein E-C1-C2 gene cluster on bovine
chromosome 18q24.
AB - We have constructed a long-range restriction map spanning about 250 kb on bovine
chromosome 18q24. Our results show that the apolipoprotein C2 (APOC2) gene is
located about 25 kb from the APOE gene. Four putative CpG islands are also
indicated in the map. Interestingly, a minisatellite located in the third intron
of the human and mouse APOC2 genes was also found at identical position in the
bovine gene and revealed high sequence identity comparing with the two
corresponding sequences. By means of cosmid mapping, we further demonstrate that
the APOE-APOC1-APOC2 gene cluster is evolutionary conserved in cattle.
PMID- 10675036
TI - Two genes encoding a putative multidrug efflux pump of the RND/MFP family are
cotranscribed with an rpoH gene in Bradyrhizobium japonicum.
AB - The rpoH3 gene of Bradyrhizobium japonicum codes for one of three sigma32-type
transcription factors in this organism and is flanked by rag (rpoH3-associated)
genes comprising the chromosomal arrangement ragABrpoH3ragCD. The first genes in
this cluster code for a classical two-component regulatory system with an unknown
function (Narberhaus et al., 1997. Mol. Microbiol. 24, 93-104). The deduced
proteins of the last two genes display a high sequence similarity to heavy metal
or multidrug efflux pumps of the RND (Resistance/Nodulation/cell Division)-MFP
(Membrane Fusion Protein) family. Reverse transcription and polymerase chain
reaction (RT-PCR) analysis demonstrated that ragC is cotranscribed with rpoH3.
Mutant strains carrying disrupted rag genes or an extented deletion of the rag
locus exhibited neither an apparent growth defect nor a deficiency in the
symbiotic interaction with soybean roots. The minimal inhibitory concentrations
(MICs) of various metals and organic compounds were identical for the wild-type
and mutant strains. Moreover, translational lacZ fusions to each of the first
four genes of the rag cluster showed a very low expression under all conditions
tested; hence, the substrate for the putative efflux pump has not been uncovered.
PMID- 10675037
TI - cDNA cloning of run, a Caenorhabditis elegans Runt domain encoding gene.
AB - PEBP2/CBF is a heterodimeric transcription factor composed of alpha and beta
subunits. The essential roles of mammalian PEBP2alpha genes, PEBP2aA/CBFA1 and
PEBP2alphaB/CBFA2 in osteogenesis and hematopoiesis have been well documented.
The PEBP2alpha proteins contain a 128 amino acid (aa) region which is highly
homologous to Drosophila melanogaster runt and lozenge. The evolutionarily
conserved region has been named the Runt domain. In this study, we isolated a
cDNA encoding the Caenorhabditis elegans homolog of mammalian PEBP2alpha. The
cDNA encodes a 301-aa protein with a highly conserved Runt domain. In addition, a
IWRPF five aa motif is present at the C-terminal end.
PMID- 10675038
TI - Expression analysis and characterization of the mutant of a growth-phase- and
starvation-regulated monofunctional catalase gene from Xanthomonas campestris pv.
phaseoli.
AB - Analysis of the Xanthomonas campestris pv. phaseoli (Xp) catalase profile using
an activity gel revealed at least two distinct monofunctional catalase isozymes
denoted Kat1 and Kat2. Kat1 was expressed throughout growth, whereas Kat2 was
expressed only during the stationary phase of growth. The nucleotide sequence of
a previously isolated monofunctional catalase gene, Xp katE, was determined. The
deduced amino acid sequence of Xp KatE showed a high percentage identity to an
atypical group of monofunctional catalases that includes the well-characterized
E. coli katE. Expression of Xp katE was growth phase-dependent but was not
inducible by oxidants. In addition, growth of Xp in a carbon-starvation medium
induced expression of the gene. An Xp katE mutant was constructed, and analysis
of its catalase enzyme pattern showed that Xp katE coded for the Kat2 isozyme. Xp
katE mutant had resistance levels similar to the parental strain against peroxide
and superoxide killing at both exponential and stationary phases of growth.
Interestingly, the level of total catalase activity in the mutant was similar to
that of the parental strain even in stationary phase. These results suggest the
existence of a novel compensatory mechanism for the activity of Xp catalase
isozymes.
PMID- 10675039
TI - Cloning and expression of the mouse Pse gene encoding a novel Ets family member.
AB - Human prostate-specific Ets (hPSE) is a novel Ets transcription factor and is
exclusively expressed in human prostate glandular epithelium. To explore the role
of PSE, we cloned the mouse Pse (mPse) and examined its pattern of expression. A
sequence analysis indicated that mPse contains a conserved carboxy-terminal ETS
DNA-binding domain and central Pointed domain, and the overall amino acid
sequence shares 86% identity with that of hPSE. The ETS DNA-binding domain is
highly conserved between human and mouse (98.8% sequence identity) and is similar
to Drosophila dets4 (76.7% identity), but not similar to other Ets factors. A
Northern blotting analysis revealed that mPse shows organ-specific expression. An
in situ hybridization analysis of the prostate and intestine showed that mPse
transcripts were present in their epithelial cells. mPse transactivates the
promoter of the MASPIN gene in transient transfection assay. These results
suggest that mPse encodes a novel Ets family member and is expressed in
epithelial cells of restricted organs.
PMID- 10675040
TI - Investigation of Schizosaccharomyces pombe as a cloning host for human telomere
and alphoid DNA.
AB - The fission yeast Schizosaccharomyces pombe (Sch. pombe) has been proposed as a
possible cloning host for both mammalian artificial chromosomes (MACs) and
mammalian genomic libraries, due to the large size of its chromosomes and its
similarity to higher eukaryotic cells. Here, it was investigated for its ability
to form telomeres from human telomere sequence and to stably maintain long
stretches of alphoid DNA. Using linear constructs terminating in the telomere
repeat, T2AG3, human telomere DNA was shown to efficiently seed telomere
formation in Sch. pombe. Much of the human telomeric sequence was removed on
addition of Sch. pombe telomeric sequence, a process similar to that described in
S. cerevisiae. To investigate the stability of alphoid DNA in fission yeast,
bacterial artificial chromosomes (BACs) containing 130 and 173 kb of alphoid DNA
were retrofitted with the Sch. pombe ars1 element and ura4+ marker using Cre-lox
recombination. These alphoid BACs were found to be highly unstable in Sch. pombe
deleting down to less than 40 kb, whilst control BACs of 96 and 202 kb,
containing non-repetitive DNA, were unrearranged. Alphoid DNA has been shown to
be sufficient for human centromere function, and this marked instability excludes
Sch. pombe as a useful cloning host for mammalian artificial chromosomes. In
addition, regions containing repetitive DNA from mammalian genomes may not be
truly represented in libraries constructed in Sch. pombe.
PMID- 10675041
TI - Structure and expression pattern of a human MTG8/ETO family gene, MTGR1.
AB - AML1-MTG8 fusion protein, which is produced from the rearranged gene formed
between AML1 and MTG8 in myeloid leukemia with t(8;21) chromosomal translocation,
plays an important role in the pathogenesis of leukemia. We previously showed
that ectopically expressed AML1-MTG8 fusion protein is associated with an MTG8
like protein in the mouse myeloid precursor cell line L-G, and this association
seemed to be required for AML1-MTG8 to stimulate proliferation. As a candidate
cDNA for this MTG8-like protein, a 6.4 kb MTGR1 cDNA encoding human MTGR1b
protein of 604 amino acids was isolated. Since this cDNA was shorter than the
main mRNA (about 7.5 kb), the 5'-end of the MTGR1 cDNA was extended using
Marathon Ready cDNA. When the newly obtained 5'-sequence was combined with the
previous cDNA, the resultant MTGR1 cDNA (6995 bp), including exon 3 that the
previous cDNA lacked, could encode MTGR1a protein of 575 amino acids. Transcripts
of the MTGR1 gene were expressed ubiquitously in the human tissues and cell lines
examined. PCR analyses of the cDNAs from human tissues showed the presence of
various splicing variants with regard to the 5'-region including exons 1, 2 and
3. The MTGR1 gene consists of 14 exons and spans about 68 kb. The genomic
structure of MTGR1 is highly similar to those of other MTG 8-family genes, MTG8
and MTG16. MTG16 was recently cloned from the translocation breakpoint of myeloid
malignancies with t(16;21) chromosomal translocation.
PMID- 10675042
TI - Identity between rat htf and human xbp-1 genes: determination of gene structure,
target sequence, and transcription promotion function for HTF.
AB - Hepatocarcinogenesis-related transcription factor (HTF) was originally isolated
from rats in which the expression was enhanced in hepatocellular carcinomas. Rat
HTF (rHTF) is structurally similar to human X-box-binding protein-1 (hXBP-1), and
both factors are unique in respective genomes. A previous study showed that hXBP
1 mRNA is detectable ubiquitously but is enriched in the human liver as rHTF. In
this study, we demonstrated the analogous exon-intron organization and
significant sequence homology for rhtf and hxbp-1 genes. Alignment of amino acid
sequences of rHTF and hXBP-1 revealed that all the characteristic motifs in rHTF
were conserved in hXBP-1. Moreover, Southern blotting patterns provided with the
rHTF and hXBP-1 probes were basically the same. These two genes were thus thought
to belong to the same evolutional lineage. We determined the consensus binding
sequence (CRCGTCA) for rHTF by CASTing, and it was found to be nearly the same as
that for hXBP-1. Transactivation ability of rHTF was also demonstrated. The rhtf
gene generates two types of mRNAs (2.0 kb and 2.5 kb), both of which encode
identical rHTF protein. These transcripts had distinct transcription initiation
sites. The 2.0 kb promoter, that was revealed by the transient luciferase assay,
contained GC-box and CAAT-box. Sequences around the transcription initiation site
for the 2.0 kb transcript were similar in rhtf and hxbp-1 genes. Our observations
suggest that HTF is a rat homolog of hXBP-1.
PMID- 10675043
TI - A highly representative two-hybrid genomic library for the yeast Yarrowia
lipolytica.
AB - Since its description by Fields and Song in 1989 (Nature 340, 245-246), the yeast
two-hybrid system has been used extensively to study protein-protein
interactions, becoming increasingly efficient with technological and
methodological improvements. Here, we report the construction of a highly
representative two-hybrid genomic library for the dimorphic yeast Yarrowia
lipolytica based on the system described by James et al. (1996. Genetics 144,
1425-1436). The endoplasmic reticulum protein Slslp was then used as a bait in a
functional test of the library. Indeed, we previously showed that the SLS1 gene
product is involved in protein translocation across the endoplasmic reticulum
membrane and interacts physically in a two-hybrid assay with Kar2p, an essential
luminal member of the HSP70 family (Boisrame et al., 1998. J. Biol. Chem. 273, 30
903-30 908). We developed a mating strategy similar to that used for the
Saccharomyces cerevisiae FRYL library (Fromont-Racine et al., 1997. Nat. Genet.
16, 277-282). No other partner than Kar2p was identified in this screen. As an
interesting result, Kar2p interacts with Slslp through its ATPase domain,
supporting our hypothesis that Slslp is a cofactor of the chaperone protein,
modulating its activity during the HSP70 cycle. Our results indicate that we have
constructed a new and powerful tool for the study of Yarrowia lipolytica, which
we believe is a good alternative model to investigate such complex biological
processes as secretion pathways.
PMID- 10675044
TI - A gene whose major transcript encodes only the substrate-binding domain of a
protein-tyrosine kinase.
AB - We have identified a novel protein-tyrosine kinase gene family in the simple
multicellular animal Hydra vulgaris that consists of at least three members. Two
of the genes encode receptor protein-tyrosine kinases. The third member of the
family is unusual in that in non-sexual animals, the only transcripts that it
produces encode polypeptides lacking all or nearly all of the ATP-binding lobe.
Characterization of multiple cDNA clones and hybridization mapping of genomic DNA
indicate that the gene, which we have termed Hinterteil (Hint), undergoes
alternative cis-splicing, alternative trans-splicing, and alternative
polyadenylation. In-situ hybridization analysis shows that expression of the gene
is upregulated during spermatogenesis. Sexual males also produce an additional
Hint transcript that is larger than the transcript seen in non-sexual animals,
but still not large enough to encode a receptor.
PMID- 10675045
TI - Selection and genetic drift of polymorphisms within the merozoite surface protein
1 gene of Plasmodium falciparum.
AB - Intragenic recombination in the merozoite surface protein-1 gene (Msp-1) of
Plasmodium falciparum is a major mechanism for allelic variation among natural
parasite populations. The frequency of recombination depends on the intensity of
transmission in the vector mosquito. In the present study, linkage disequilibrium
between polymorphic 'loci' in the 5'- and 3'-regions of Msp-1 was examined in
parasite populations from Brazilian Amazon and southern Vietnam and compared with
that in a Thai population previously reported. The R2 test identified clusters of
linkage disequilibria between the 5'- and 3'-regions, which are different among
the three populations. However, the overall strength of linkage disequilibria was
stronger in Brazil, a hypoendemic area, than in Vietnam and Thailand, mesoendemic
areas, suggesting that linkage disequilibrium in Msp-1 inversely correlates with
the intensity of transmission. To investigate possible mechanisms for linkage
disequilibrium in Msp-1, we applied the Fst index, which measures the inter
population variance in allele frequency, to 'loci' in Msp-1 among the three
populations. The Fst test identified two distinct regions with respect to inter
population allele frequency in Msp-1: one for highly divergent 'loci' in the 5'
region and the other for non-divergent 'loci' in the 3'-region. These results
suggest that genetic drift is not the sole mechanism for linkage disequilibrium,
but selection operates on 'loci' in the 3'-region in hypo- and mesoendemic areas
of malaria.
PMID- 10675046
TI - S phase-specific DNA-binding proteins interacting with the Hex and Oct motifs in
type I element of the wheat histone H3 promoter.
AB - The type I element (CCACGTCANCGATCCGCG), consisting of the Hex motif (CCACGTCA)
and the reverse-oriented Oct motif (GATCCGCG), is necessary and sufficient to
confer the S phase-specific transcription of the wheat histone H3 (TH012) gene.
The transcriptional regulation via the type I element is thought to occur through
interactions between transcription factors which bind specifically to the Hex and
Oct motifs. Here we report S phase-specific DNA-binding proteins interacting with
the type I element in partially synchronized wheat cultured cells. Hex motif
binding proteins found here resembled HBP-1a, as reported previously in terms of
DNA-binding specificity. DNA-binding activities of the HBP-1a-like proteins were
modulated by phosphorylation/dephosphorylation. In the electrophoretic mobility
shift assay of the wheat nuclear extract, we also found three Oct motif-specific
binding proteins, named OBRF (octamer-binding regulatory factor)-1, -2 and -3.
One of the HBP-1a-like proteins and OBRF-1 appeared predominantly at the S phase.
Thus, it was supposed that these two factors play a crucial role in the S phase
specific regulation of wheat histone gene expression.
PMID- 10675047
TI - Finding ways to create connections among communities: partial results of an
ethnography of urban public health nurses.
AB - The purpose of this ethnographic study was to describe the culture of public
health nurses (PHNs) in a large, Midwestern urban health department. Data
collection methods, data management, and analyses followed ethnographic
procedures and resulted in the development of categories, domains, and cultural
themes. The general study participants were PHNs, clients, supervisors, and
administrators. The primary cultural theme that emerged was that public health
nursing is finding ways to create connections among communities. Three
interacting communities were identified: the local communities, communities
created by individuals and families, and communities of resources. This article
describes one of the three subthemes that emerged, processes used to help clients
create connections, and describes how caring is shown uniquely in public health
nursing. As a result of the study, implications for nursing practice, education,
and research were developed. The results of the study supported a position that
public health nursing is a unique nursing specialty. It reinforced also the
applicability of an ethnographic design and methodology to nursing research.
PMID- 10675048
TI - Cudahy high school survey and focus groups: assessment of the needs of a teen
population. A community-campus collaboration.
AB - Collaboration between local public health agencies and university schools of
nursing can be advantageous to both parties. Students need opportunities to learn
aggregate-based care; health officers need community partnerships that expand
their potential to accomplish core functions. This article offers a case study to
illustrate a collaborative relationship. A high school survey and a plan for teen
services were the focus of the joint endeavor. With guidance from faculty,
students offered labor and expertise; the agency offered a real world laboratory
for learning.
PMID- 10675049
TI - The relationship between self-esteem, health habits, and knowledge of BSE
practice in female inmates.
AB - This article reports on data derived from an investigation of the self-esteem,
health habits, and knowledge of breast self-examination (BSE) practice in female
inmates. A descriptive correlational study was conducted with a prison sample of
197 adult females incarcerated in a women's state prison. Major findings of the
study suggest that female inmates in general had medium to high self-esteem, poor
health habits before incarceration, and minimal knowledge about BSE practice.
Only 26% reported correct knowledge related to frequency in BSE practice, and few
reported that they knew correct BSE technique. In addition, findings suggest that
a correlation does not exist between self-esteem and knowledge of BSE practice,
and participants' last grade completed served as a good predictor of women's
knowledge of BSE practice.
PMID- 10675050
TI - Gender issues and Japanese family-centered caregiving for frail elderly parents
or parents-in-law in modern Japan: from the sociocultural and historical
perspectives.
AB - This paper presents a sociocultural and historical literature review of gender
related issues associated with family-centered caregiving for frail, elderly
relatives in modern Japan. Issues addressed from a Japanese perspective are (a)
women and social norms of caregiving, (b) feminine identity and caregiving, (c)
women in the workforce, and (d) women and caregiving. Implications for research
are also discussed.
PMID- 10675051
TI - Validating the safety of nurse-health advocate services.
AB - Prior to promoting the use of community health care advocates for home visits, it
is necessary to evaluate their ability to safely screen for health problems. This
study examined trained maternal-child health advocates (MCHAs) who, supervised by
professional nurses, conducted maternal-child home visits consisting of health
promotion and problem identification. Problems identified by MCHAs were compared
to problems identified by professional, validating nurses, who were not part of
the service project, on hypothetical home visit situations and during 213
duplicate home visits. There were no significant differences between MCHAs and
professional nurses in their identifications of infant health problems, infant
health care deficits, other family members' health problems, prenatal care
deficits, emotional problems, and substance abuse on either the hypothetical home
visits or the duplicate home visits. The validating nurses identified
significantly more women's health problems (p = 0.01) and women's health care
deficits (p = 0.02) than the MCHAs on the duplicate home visits. These findings
validate the safety of using the model of trained community health advocates
teamed with registered nurses to screen for infant health problems during home
visits.
PMID- 10675052
TI - Personal safety, violence, and home health.
AB - A critical issue facing the health care industry today is the potential impact of
community and interpersonal violence on home health care. The purposes of this
study were to (1) serve as a source for understanding the personal safety risk
issues facing home care staff in a large Midwest region and its surrounding rural
areas; (2) provide an understanding of how perceived threats to personal safety
may impact patient care and patient outcomes; (3) identify strategies for
increasing the personal safety of direct care staff; and (4) identify
organizational, educational, and procedural issues that impede or enhance staff
safety. A triangulated qualitative design was used including focus groups, in
depth individual interviews, critical event narratives, and a participant self
report form. The study used a purposive sample consisting of 5 men and 56 women
who were either administrators or direct care staff from 13 home health agencies.
Seven major themes emerged: (1) unsafe conditions that direct care staff must
face; (2) organizational and administrative issues that impede or promote the
personal safety of staff; (3) ethical issues staff face daily; (4) protective
factors associated with maintaining safety; (5) issues of gender, race, age, and
experience; (6) education and training; and (7) the potential impact that staff's
fear of interpersonal and community violence can have on patient care and patient
outcomes.
PMID- 10675053
TI - Prevention strategies other than male condoms employed by low-income women to
prevent HIV infection.
AB - This study sought to determine HIV prevention strategies other than male condom
use employed by low-income women who have sex with men (WSM) and to identify
variables that predict use of these strategies. A cross-sectional survey of
nearly 4,000 women receiving Women, Infants, and Children (WIC) benefits in 21
Missouri counties was conducted. The response rate was 58%, with 2,256 completed
questionnaires returned. Women were asked to indicate one or more of nine methods
they had ever used to prevent HIV infection. Women were also asked about their
use of male condoms, preference for male condoms versus female condoms, and which
partner usually made decisions about STD/HIV prevention. Of the 2,256
questionnaires returned, 1,325 WSM indicated use of at least one HIV prevention
strategy other than condom use. Strategies were: being tested for HIV (68.2%),
partner being tested for HIV (44.1%), asking partner about his sex history
(41.1%), using oral contraceptives (18.8%), asking him if he has HIV (13.7%),
douching (11.8%), withdrawal (9.4%), and having anal or oral sex (6.6%). Common
predictors of these strategies were race, education, history of STD, condom use,
and marital status. Basic misunderstandings about HIV prevention are common in
specified subpopulations of low-income women. HIV prevention programs for low
income WSM should capitalize on women's efforts to prevent HIV by designing
programs to help women replace ineffective prevention strategies with effective
prevention strategies.
PMID- 10675054
TI - A case study in translation methodology using the Health-Promotion Lifestyle
Profile II.
AB - Although Hispanics constitute the most rapidly growing segment of the population
in the United States, they have received relatively little attention regarding
factors affecting their health behaviors and influences. One such factor is the
scarcity of reliable and valid Spanish-language instruments for research with
this population. Researchers who attempt to translate an existing instrument into
Spanish need to recognize the methodological issues involved in the translation
process and psychometric testing. The purpose of this article is to describe the
advantages and disadvantages of various translation methodologies, to identify
statistical issues in cross-cultural research, and to provide a case study of the
translation process and statistical analysis of a translated instrument.
Specifically, this study looks at the development and pilot testing of a Spanish
language version of the Health-Promoting Lifestyle Profile II using a randomized
convenience sample of 60 bilingual Hispanic individuals.
PMID- 10675055
TI - An investigation of perceived exertion via whole body exertion and direct muscle
force indicators during the determination of the maximum acceptable weight of
lift.
AB - The objective of this study was to identify the perceived exertion mechanisms
(direct muscle force and whole body exertion) associated with the decision to
change the weight of lift during the determination of the maximum acceptable
weight of lift (MAWL). Fifteen males lifted a box of unknown weight at a rate of
4.3 lifts/min, and adjusted the weight until their MAWL was reached. Variables
such as the predicted muscle forces and heart rate were measured during the
lifting exertion, as well as the predicted spinal loading in three dimensions
using an EMG-assisted biomechanical model. Multiple logistic regression
techniques were used to identify variables that were associated with the decision
to change the weights up and down prior to a subsequent lift. Results indicated
that the force in the left erector spinae, right internal oblique, and left
latissimus dorsi muscles as well as heart rate were associated with decreases in
the weight prior to the next lift. It appears that a combination of local factors
(muscle force) and whole body exertion factors (heart rate) provide the feedback
for the perceived exertion when decreasing the weight. The up-change model
indicated that the forces of the right erector spinae, left internal oblique, and
the right latissimus dorsi muscles were associated with the decision to increase
the weight prior to the next lift. Thus, local factors provide feedback during
the decision to increase the weight when starting from light weights.
Collectively, these findings indicate that psychophysically determined weight
limits may be more sensitive to muscular strain rather than spinal loading.
PMID- 10675056
TI - Calculation of times to exhaustion at 100 and 120% maximal aerobic speed.
AB - The aim was to compare physiologic responses during exhaustive runs performed on
a treadmill at 100 and 120% maximal aerobic speed (MAS: the minimum speed that
elicits VO2max). Fourteen subelite male runners (mean +/- SD; age = 27+/-5 years;
VO2max = 68.9+/-4.6 ml/kg(-1)/min(-1); MAS = 21.5+/-1 km/h(-1)) participated.
Mean time to exhaustion tlim100% at 100% MAS (269+/- 77s) was similar to those
reported in other studies. However, there was large variability in individual
tlim100% MAS (CV = 29%). MAS was positively correlated with VO2max (r = 0.66,
p<0.05) but not with tlim100%) MAS (r = -0.50, p<0.05). tlim100% MAS was
correlated with t(lim) at 120% MAS (r = 0.52, p < 0.05) and to blood pH following
the rest at 120% MAS (r = -0.68, p<0.05). The data suggest that running time to
exhaustion at MAS in subelite male runners is related to time limit at 120%
(tlim120%) MAS. Moreover, anaerobic capacity determined by the exercise to
exhaustion at 120% MAS can be defined as the variable 'a' in the model of Monod
and Scherrer (1954).
PMID- 10675057
TI - Optimum seat pan and back-rest parameters for a comfortable tractor seat.
AB - An experimental set up was fabricated to measure the pressure distribution on the
seat pan and back-rest of a tractor seat. Experiments were conducted with four
different seat pans having radius of curvatures of 60, 75, 90 and infinity cm,
four back-rests with radius of curvatures of 30, 60, 90 and infinitity cm, and
three back-rest inclinations of 0 degrees , 5 degrees and 10 degrees on
representative Indian tractor operators. The subjective assessment of perceived
comfort at the seat-operator interface was also recorded. Experiments were
conducted in a randomized block design and the data obtained were analysed using
suitable computer packages. Results indicate that all the parameters, namely seat
pan, back-rest profile curvatures and the back-rest angle of inclination, affect
the pressure distribution. It is concluded that a seat pan with radius of
curvature 75 cm, back-rest with radius of curvature 30 cm and back-rest
inclination of 10 degrees are the most suitable parameters for Indian tractor
operators.
PMID- 10675058
TI - On-line driver workload estimation. Effects of road situation and age on
secondary task measures.
AB - In order to develop a driver-car interface that adapts the presentation of
messages generated by in-vehicle information systems to driver workload, two
experiments investigated potential determinants of driver visual and mental
workload as indicated by performance on two secondary tasks. Experiment 1
suggested that road situation is a major determinant of visual and mental
workload of the driver and that the processing resources of older drivers are
somewhat more limited than those of younger and middle-aged drivers. Familiarity
with the area of driving (when guided) and time of day (associated with traffic
density) showed no secondary task effects. Experiment 2 showed that the
categorization of road situations, proposed in Experiment 1, could underlie
adaptation of visually loading messages to the workload incurred by driving. This
was not found with respect to mentally loading messages.
PMID- 10675059
TI - The effects of hyperoxia on performance during simulated firefighting work.
AB - This study evaluated the effects of hyperoxia (inspired oxygen fraction = 40%) on
performance during a simulated firefighting work circuit (SFWC) consisting of
five events. On separate days, 17 subjects completed at least three orientation
trials followed by two experimental trials while breathing either normoxic (NOX)
and hyperoxic (HOX) gas mixtures that were randomly assigned in double-blind,
cross-over design. Previously, ventilatory threshold (Tvent) and VO2max had been
determined during graded exercise (GXT) on a cycle ergometer. Lactate
concentration in venous blood was assessed at exactly 5 min after both the
experimental trials and after the GXT. Total time to complete the SFWC was
decreased by 4% (p < 0.05) with HOX. No differences were observed in individual
event times early in the circuit, however HOX resulted in a 12% improvement (p <
0.05) on the final event. A significantly decreased rating of perceived exertion
(RPE) was also recorded immediately prior to the final event. No differences were
observed in mean heart rate or post-exercise blood lactate when comparing NOX to
HOX. Heart rates during the SFWC (both conditions) were higher than HR at Tvent,
but lower than HR at VO2max (p<0.05). Post-SFWC lactate values were higher
(p<0.05) than post-VO2max. These results demonstrate that hyperoxia provided a
small but significant increase in performance during short duration, high
intensity simulated firefighting work.
PMID- 10675060
TI - Road-edge delineation in rural areas: effects on driving behaviour.
AB - When driving on lower-category Dutch rural roads without any delineation, drivers
are likely to drift off the road with their right-side wheels, thus incurring
damage to the pavement edge or even leading to accidents. In two experiments, two
types of road-edge delineation, with continuous or dashed edge lines, were
compared with two control roads without lines or with only a dashed line on the
road axis. The first experiment consisted of non-obtrusive video recordings of
passing traffic. Vehicle position on the experimental roads was more to the
road's centre than on the control roads. The second experiment was a driving test
with an instrumented vehicle, during daytime lighting and during darkness. Again,
vehicle lateral position was more central on the experimental roads, especially
during darkness. Subjects could safely pass oncoming vehicles. Driving speed
increased on the experimental roads compared with the unlined control road, but
not beyond speeds found on the axis-lined control road. Driver's mental effort
while driving over the experimental roads did not differ from the effort while
driving over the control roads. Subjectively rated effort was higher for the
unlined control road than for the three other roads. Subjects preferred the edge
lined roads to the unlined control road, but not more than the axis-lined control
road. It was concluded that edge-lines may provide a simple and effective way of
inducing a more favourable lateral position on rural roads without having
negative effects on subjective appraisal, driving performance or mental workload.
PMID- 10675061
TI - Temporal variation in the luminance level of stimuli displayed on a cathode-ray
tube monitor: effects on performance on a visual vigilance task.
AB - This paper assesses the extent to which the sensitivity decrement frequently
observed in vigilance tasks is affected by temporal variations in the luminance
level of the stimuli displayed on the screen of a cathode-ray tube (CRT) monitor.
First, it was confirmed that the luminance of the stimuli displayed on the screen
of the CRT monitor decreases substantially during the first hour after turning
the monitor on, and then it remains quite stable. Second, an experiment was
carried out in which participants performed a visual vigilance task at three
different time periods within which the luminance of the stimuli displayed on the
screen of a CRT monitor either decreased or remained stable. The results indicate
that the vigilance decrement is modulated by temporal fluctuations of the
luminance of the monitor screen, which is used to display the stimuli. However,
the relationship between both variables is not simple: the largest sensitivity
decrement was not associated with the largest luminance decrement, but to a
medium luminance decrement.
PMID- 10675062
TI - Perceived fatigue after mental work: an experimental evaluation of a fatigue
inventory.
AB - The aim of this study was to investigate the perceived fatigue after mental work
and to test the Swedish Occupational Fatigue Inventory (SOFI). Twenty male and 20
female participants worked with proof reading (2 x 90 min) and a vigilance task
(2 x 60 min). After each task session, perceived fatigue was rated with the SOFI
and Borg's CR10O-scale. In addition, physiological reactions were registered;
blood pressure, heart rate, heart rate variability and muscle activity in
corrugator supercilii, as well as measures of performance: reaction time, number
of pages read and number of proof errors found, number of detected signals. As
expected, the highest ratings were obtained on Lack of energy, Lack of motivation
and Sleepiness, particularly after the vigilance task. High ratings after both
work tasks were also found on the CR10-scale. Men and women did not differ
significantly with respect to their ratings. No clear-cut physiological reactions
were found to correlate with ratings of fatigue. The results indicate the
validity of the mental dimension of the SOFI.
PMID- 10675063
TI - Gender differences in exerted forces and physiological load during pushing and
pulling of wheeled cages by postal workers.
AB - The aim was to determine gender differences regarding exerted forces and
physiological load during push/pull tasks simulating the daily working practice
of postal workers. Eight female and four male workers handled four-wheeled cages
under eight conditions corresponding to the cage weight (130, 250, 400, 550 kg)
and the direction of force exertion (pushing, pulling). For each of the five
dependent variables, average force, initial force, ending force, oxygen uptake
and heart rate, two analyses of variance with repeated measurements were
performed, i.e. with and without correction for the worker's body weight, body
height and maximum capacity regarding the dependent variable. Exerted forces and
physiological load were high for the cages weighing 400 and 550 kg. Gender
differences were significant for all dependent variables (p = 0.030-0.000). When
the personal factors were included in the model, male workers exerted
significantly higher average forces and ending forces than their females, while
differences regarding initial forces and physiological load were not significant.
However, none of the personal factors were significantly related to any of the
dependent variables. It is concluded that gender differences in exerted forces
were not caused by differences in anthropometry and maximum capacity, but due to
application of different work methods by women in order to balance work demands
and work ability.
PMID- 10675064
TI - A survey of hand anthropometry of female rural farm workers in Ibadan, western
Nigeria.
AB - An anthropometric survey measuring 18 dimensions of the right hand in 37 female
rural farm workers living in Ibadan, western Nigeria was conducted. The means,
standard deviations and percentile values are reported for these. The means of
the collected data are compared with those for females from the UK, from Hong
Kong and from America, using data from other published studies. The results
suggest that the Nigerian female hand is wider and thicker, but shorter than that
of their foreign counterparts. Such differences have implications for design and
evaluation of hand tools for the Nigerian female population.
PMID- 10675065
TI - When doctors become agents of the state.
PMID- 10675066
TI - HOPE and extension of the indications for ACE inhibitors? Heart Outcomes
Prevention Evaluation.
PMID- 10675067
TI - Fluoride and fractures: an ecological fallacy.
PMID- 10675068
TI - New insights into role of microenvironment in multiple myeloma.
PMID- 10675069
TI - Perineal massage for prevention of perineal trauma in childbirth.
PMID- 10675070
TI - Antenatal corticosteroids: is more better? .
PMID- 10675071
TI - Effects of ramipril on cardiovascular and microvascular outcomes in people with
diabetes mellitus: results of the HOPE study and MICRO-HOPE substudy. Heart
Outcomes Prevention Evaluation Study Investigators.
AB - BACKGROUND: Diabetes mellitus is a strong risk factor for cardiovascular and
renal disease. We investigated whether the angiotensin-converting-enzyme (ACE)
inhibitor ramipril can lower these risks in patients with diabetes. METHODS: 3577
people with diabetes included in the Heart Outcomes Prevention Evaluation study,
aged 55 years or older, who had a previous cardiovascular event or at least one
other cardiovascular risk factor, no clinical proteinuria, heart failure, or low
ejection fraction, and who were not taking ACE inhibitors, were randomly assigned
ramipril (10 mg/day) or placebo, and vitamin E or placebo, according to a two-by
two factorial design. The combined primary outcome was myocardial infarction,
stroke, or cardiovascular death. Overt nephropathy was a main outcome in a
substudy. FINDINGS: The study was stopped 6 months early (after 4.5 years) by the
independent data safety and monitoring board because of a consistent benefit of
ramipril compared with placebo. Ramipril lowered the risk of the combined primary
outcome by 25% (95% CI 12-36, p=0.0004), myocardial infarction by 22% (6-36),
stroke by 33% (10-50), cardiovascular death by 37% (21-51), total mortality by
24% (8-37), revascularisation by 17% (2-30), and overt nephropathy by 24% (3-40,
p=0.027). After adjustment for the changes in systolic (2.4 mm Hg) and diastolic
(1.0 mm Hg) blood pressures, ramipril still lowered the risk of the combined
primary outcome by 25% (12-36, p=0.0004). INTERPRETATION: Ramipril was beneficial
for cardiovascular events and overt nephropathy in people with diabetes. The
cardiovascular benefit was greater than that attributable to the decrease in
blood pressure. This treatment represents a vasculoprotective and renoprotective
effect for people with diabetes.
PMID- 10675072
TI - Long-term results of overlapping anterior anal-sphincter repair for obstetric
trauma.
AB - BACKGROUND: Anterior structural damage to the anal sphincter occurs in up to a
third of women at first vaginal delivery, and of these a third have new bowel
symptoms. The standard treatment for such structural damage is anterior
overlapping anal-sphincter repair. We aimed to assess the long-term results of
this operation. METHODS: We assessed the long-term results in 55 consecutive
patients who had had repair a minimum of 5 years (median 77 months [range 60-96])
previously. Questionnaire and telephone interview assessed current bowel function
and continence, restriction in activities related to bowel control, and overall
satisfaction with the results of surgery. 42 of these patients had been continent
of solid and liquid stool at a median of 15 months after the repair. FINDINGS: We
were able to contact 47 (86%) of the 55 patients. One of these patients had
required a proctectomy and end ileostomy for Crohn's disease. Of the remaining 46
patients, 27 reported improved bowel control without the need for further
surgery, and 23 rated their symptom improvement as 50% or greater. Seven patients
had undergone further surgery for incontinence and one patient had not had a
covering stoma closed. Thus, the long-term functional outcome of the sphincter
repair alone could be assessed in 38 patients. Of these patients, none was fully
continent to both stool and flatus; only four were totally continent to solid and
liquid stool; six had no faecal urgency; and eight had no passive soiling. Of the
38 patients, 20 still wore a pad for incontinence and 25 reported lifestyle
restriction. 14 reported the onset of a new evacuation disorder after sphincter
repair. 23 of the 46 patients contacted had a successful long-term outcome
(defined as no further surgery and urge faecal incontinence monthly or less).
INTERPRETATION: The results of overlapping sphincter repair for obstetric anal
sphincter damage seem to deteriorate with time. Preoperative counselling should
emphasise that although most patients will improve after the procedure,
continence is rarely perfect, many have residual symptoms, and some may develop
new evacuation disorders.
PMID- 10675073
TI - Fluoride in drinking water and risk of hip fracture in the UK: a case-control
study.
AB - BACKGROUND: Although the benefits of water fluoridation for dental health are
widely accepted, concerns remain about possible adverse effects, particularly
effects on bone. Several investigators have suggested increased rates of hip
fracture in places with high concentrations of fluoride in drinking water, but
this finding has not been consistent, possibly because of unrecognised
confounding effects. METHODS: We did a case-control study of men and women aged
50 years and older from the English county of Cleveland, and compared patients
with hip fracture with community controls. Current addresses were ascertained for
all participants; for those who agreed to an interview and who passed a mental
test, more detailed information was obtained about lifetime residential history
and exposure to other known and suspected risk factors for hip fracture.
Exposures to fluoride in water were estimated from the residential histories and
from information provided by water suppliers. Analysis was by logistic
regression. FINDINGS: 914 cases and 1196 controls were identified, of whom 514
and 527, respectively, were interviewed. Among those interviewed, hip fracture
was strongly associated with low body-mass index (p for trend <0.001) and
physical inactivity (p for trend <0.001). Estimated average lifetime exposure to
fluoride in drinking water ranged from 0.15 to 1.79 ppm. Current residence in
Hartlepool was a good indicator for high lifetime exposure to fluoride. After
adjustment for potential confounders, the odds ratio associated with an average
lifetime exposure to fluoride > or =0.9 ppm was 1.0 [95% CI 0.7-1.5].
INTERPRETATION: There is a low risk of hip fracture for people ingesting fluoride
in drinking water at concentrations of about 1 ppm. This low risk should not be a
reason for withholding fluoridation of water supplies.
PMID- 10675074
TI - Hormone replacement therapy and accuracy of mammographic screening.
AB - BACKGROUND: Hormone replacement therapy (HRT) is commonly used and may affect the
accuracy of mammographic screening. METHODS: We examined the sensitivity,
specificity, and small-cancer detection rate according to HRT use in 103,770
women in Victoria, Australia, who attended first-round screening in 1994 and who
did not have a personal history of breast cancer or a breast lump or a
bloodstained or watery nipple discharge at the time of screening. BreastScreen
Victoria provides mammography to women aged 40 years and older every 2 years.
Unconditional logistic modelling was used to adjust for age, family history, and
symptom status. FINDINGS: The sensitivity of screening mammography for a 2-year
screening interval was lower in HRT users (64.8% [95% CI 58-72]) than non-users
(77.3% [74-81]). In the target group (50-69 years), the sensitivity was 64.3% (57
72) in HRT users and 79.8% (76-84) in non-users. Among women who were diagnosed
with cancer during the 2-year screening interval, HRT users were more likely to
have a false negative result than non-users (odds ratio 1.60 [1.04-2.21]) after
adjusting for potential confounding factors. Specificity was 0.6% lower in HRT
users compared with non-users. Among women who did not have cancer diagnosed in
the interval, HRT users were more likely to have a false positive result
(adjusted odds ratio 1.12 [1.05-1.19]). INTERPRETATION: We show that HRT use
reduces the sensitivity of mammographic screening. In countries where HRT use is
widespread, the reduction in sensitivity with HRT use may undermine the capacity
of population-based mammographic-screening programmes to realise their potential
mortality benefit.
PMID- 10675075
TI - Infectiousness of Mycobacterium tuberculosis in HIV-1-infected patients with
tuberculosis: a prospective study.
AB - BACKGROUND: Previous studies concerning the relative infectiousness of HIV-1
positive individuals with pulmonary tuberculosis have produced conflicting
results. Thus, we assessed the effect of HIV-1 on the infectiousness of
Mycobacterium tuberculosis in a prospective study. METHODS: We organised in Santo
Domingo, Dominican Republic, a cohort study of household contacts of HIV-1
positive and HIV-1-negative individuals with newly diagnosed pulmonary
tuberculosis. Household contacts were assessed at their houses at baseline and
followed up for 14 months for evidence of M tuberculosis infection and
tuberculosis with a multi-step tuberculin skin test, anergy skin test, physical
examinations, chest radiographs, and sputum smears. FINDINGS: Tuberculin
induration of 5 mm or greater was seen in 153 (61%) of 252 household contacts of
HIV-1-positive index cases and in 418 (76%) of 551 household contacts of HIV-1
negative index cases (odds ratio 0.49 [95% CI 0.35-0.67], p=0.00001). In
multivariate logistic-regression analysis after allowance for between-household
variation in tuberculin response, HIV-1 infection of the index case remained
inversely associated with the tuberculin response of the household contacts (0.52
[0.29-0.93], p=0.02). When the analysis was restricted to household contacts aged
between 2 years and 15 years the adjusted association remained significant (0.37
[0.14-0.98], p=0.04). Among household contacts who had a negative tuberculin skin
test at baseline, conversion to tuberculin skin test positivity was less frequent
among household contacts of HIV-1-positive index cases (cut-off > or =5 mm:
32/131 [24%] vs 71/204 [35%], p=0.05; cut-off > or =10 mm: 23/153 [15%] vs 55/245
[22%], p=0.07). INTERPRETATION: These data suggest that HIV-1-positive
individuals with tuberculosis are less likely than HIV-1-negative individuals
with tuberculosis to transmit M tuberculosis to their close contacts. No changes
in the current policy regarding tuberculosis contact tracing are needed in the
presence of HIV-1.
PMID- 10675076
TI - Colitis associated with docetaxel-based chemotherapy in patients with metastatic
breast cancer.
AB - BACKGROUND: Docetaxel and vinorelbine as combined treatment for metastatic breast
cancer can have the dose-limiting toxic effects of mucositis and neutropenic
fever. We report unexpected ischaemic colitis in six patients associated with
docetaxel-based therapy, three of whom were treated in a phase I study designed
to establish the maximum tolerated dose of this combination with the prophylactic
use of granulocyte-colony-stimulating factor. METHODS: Between August, 1997, and
December, 1998, 14 patients with metastatic breast cancer were treated with
vinorelbine, docetaxel, and granulocyte-colony-stimulating factor in a phase I
study. Three patients developed colitis similar to that seen in typhlitis. Three
additional patients were identified during scheduled review of toxic effects in
patients participating in clinical trials involving docetaxel. FINDINGS: Three
patients on combined vinorelbine and docetaxel developed colitis-like symptoms.
Two patients died, one from necrotic bowel and the other from neutropenic fever
and colitis. Two of the patients presented on day 7 and day 8 of chemotherapy,
respectively, with neutropenic fever and abdominal pain; the third patient
developed neutropenia without fever and abdominal pain on day 8. The other three
patients were treated with docetaxel, docetaxel and pamidronate disodium, or
docetaxel and cyclophosphamide. All three patients presented with abdominal pain
on days 10, 5, and 4, respectively. One had non-neutropenic fever, another had
neutropenic fever, and the third was afebrile and non-neutropenic at the time of
presentation with abdominal pain. Three patients had blood in their diarrhoea,
abdominal tenderness, or both. Computed tomography of the abdomen and pelvis
showed features of colitis in three patients. INTERPRETATION: This serious
complication may result from the use of docetaxel and may be exacerbated by its
combination with vinorelbine. Study of hospital-based patients treated with
taxane-based chemotherapy is underway to find out the frequency of such
complications.
PMID- 10675077
TI - A cough, then respiratory failure.
PMID- 10675078
TI - Impact of immunisation on pertussis transmission in England and Wales.
AB - Pertussis immunisation reduces disease frequency, but is not thought to prevent
transmission. We show that vaccination has substantially reduced transmission in
England and Wales.
PMID- 10675079
TI - Autoimmune T cells as potential neuroprotective therapy for spinal cord injury.
AB - Autoimmune T cells against central nervous system myelin associated peptide
reduce the spread of damage and promote recovery in injured rat spinal cord,
findings that might lead to neuroprotective cell therapy without risk of
autoimmune disease.
PMID- 10675080
TI - Structured treatment interruptions to control HIV-1 infection.
AB - Structured treatment interruptions progressively lowered the rate of viral
rebound in some HIV-1 infected patients. This approach should be explored as an
alternative to continuous antiretroviral therapies.
PMID- 10675081
TI - Paclitaxel hypersensitivity reactions related to bee-sting allergy.
AB - Patients with a history of beesting allergy may have a higher risk of a
hypersensitivity reaction with paclitaxel treatment. We suggest careful screening
of patients for allergies.
PMID- 10675082
TI - Neuroleptic malignant syndrome after venlafaxine.
AB - A patient developed neuroleptic malignant syndrome after a single dose of
venlafaxine with trifluoperazine treatment. A dopamine-inhibition effect induced
by one dose of venlafaxine may have augmented dopamine-receptor inhibition by
trifluoperazine.
PMID- 10675083
TI - Corneal opacities after cataract surgery with hypromellose.
AB - 26 cases of corneal opacity after cataract surgery occurred in a period of 2
weeks in one surgical unit. Cases occurred after a change in source of
intraocular hypromellose solution and only among patients in whom the new product
had been used.
PMID- 10675084
TI - Russian biomedical science survives against all odds.
PMID- 10675085
TI - Building capacity for primary care in Tajikistan.
PMID- 10675086
TI - Mitochondrial respiratory chain disorders I: mitochondrial DNA defects.
AB - Mitochondria have a pivotal role in cell metabolism, being the major site of ATP
production via oxidative phosphorylation (OXPHOS); they have a critical role in
apoptotic cell death; and they also contribute to human genetics since
mitochondria have a functional genome separate from that of nuclear DNA. Defects
of mitochondrial metabolism are associated with a wide spectrum of disease. An
Important part of this spectrum is caused by mutations of mitochondrial DNA
(mtDNA). These class I OXPHOS diseases are covered in part I of this two-part
review. Dysfunction of mitochondrial OXPHOS has also emerged as an important
component of a range of predominantly neurodegenerative diseases in which the
mitochondrial abnormality is most probably secondary. These class II OXPHOS
diseases are due to mutations of genes not encoding OXPHOS subunits or are caused
by exogenous or endogenous OXPHOS toxins. Class II mitochondrial diseases and the
mitochondrion's role in apoptosis are covered in part II (Lancet 2000; 355: 389
94).
PMID- 10675087
TI - New light on cranial surgery in ancient Rome.
PMID- 10675088
TI - Association studies of genetic polymorphisms and complex disease.
PMID- 10675089
TI - Biocompatibility and acute renal failure.
PMID- 10675090
TI - Biocompatibility and acute renal failure.
PMID- 10675091
TI - Biocompatibility and acute renal failure.
PMID- 10675092
TI - Biocompatibility and acute renal failure.
PMID- 10675093
TI - Mini mental state examination.
PMID- 10675094
TI - An unfortunate case of allergy to latex.
PMID- 10675095
TI - Are drugs interchangeable?
PMID- 10675096
TI - Are drugs interchangeable?
PMID- 10675097
TI - Are drugs interchangeable?
PMID- 10675098
TI - Pseudoseizures versus epileptic seizures in pregnancy.
PMID- 10675099
TI - Cortical origins of pathological pain.
PMID- 10675100
TI - Medical implications of HGP's sequence of chromosome 22.
PMID- 10675101
TI - Treatment and secondary prevention of stroke.
PMID- 10675102
TI - Treatment and secondary prevention of stroke.
PMID- 10675103
TI - Treatment and secondary prevention of stroke.
PMID- 10675104
TI - Why such diverse prices of infant formula in Europe?
PMID- 10675105
TI - Youthful memories: a tribute to David Baum.
PMID- 10675106
TI - Baby 1, obstetrician 0.
PMID- 10675107
TI - Overoptimism about cancer.
PMID- 10675108
TI - Improving outcome of cataract surgery in developing countries.
PMID- 10675109
TI - Measures and meaning of blood pressure.
PMID- 10675110
TI - Response of metastatic breast cancer to trastuzumab?
PMID- 10675111
TI - Should men still go bald gracefully?
PMID- 10675112
TI - Progressive forms of MS: classification streamlined or consensus overturned?
PMID- 10675113
TI - Lack of significant hormonal effects and controlled trials of phyto-oestrogens.
PMID- 10675114
TI - Risks of leukaemia and solid tumours in individuals with Down's syndrome.
AB - BACKGROUND: Individuals with Down's syndrome have a greater risk of leukaemia
than the general population, but reliable estimates of the age-specific risk are
lacking and little is known about the risk of solid tumours. METHODS: We
identified 2814 individuals with Down's syndrome from the Danish Cytogenetic
Register, and linked the data to the Danish Cancer Registry. The number of person
years at risk was 48453. Standardised incidence ratio (SIR) and 95% CI were
calculated of the basis of cancer rates specific for age and sex in the general
population. FINDINGS: 60 cases of cancer were found, with 49.8 expected (SIR 1.20
[95% CI 0.92-1.55]). Leukaemia constituted 60% of cases of malignant disease
overall and 97% of cases in children. The SIR for leukaemia varied with age,
being 56 (38-81) at age 0-4 years and 10 (4-20) at 5-29 years. No cases of
leukaemia were seen after the age of 29 years. The SIR for acute myeloid
leukaemia was 3.8 (1.7-8.4) times higher than that for acute lymphoblastic
leukaemia in children aged 0-4 years. The cumulative risk for leukaemia by the
age of 5 years was 2.1% and that by 30 years was 2.7%. Only 24 solid tumours were
seen, with 47.8 expected (0.50 [0.32-0.75]). No cases of breast cancer were
found, with 7.3 expected (p=0.0007). Higher than expected numbers of testicular
cancers, ovarian cancers, and retinoblastomas were seen but were not significant.
INTREPRETATION: The occurrence of cancer in Down's syndrome is unique with a high
risk of leukaemia in children and a decreased risk of solid tumours in all age
groups. The distinctive pattern of malignant diseases may provide clues in the
search for leukaemogenic genes and tumour-suppressor genes on chromosome 21.
PMID- 10675115
TI - Laparoscopic or conventional Nissen fundoplication for gastro-oesophageal reflux
disease: randomised clinical trial. The Netherlands Antireflux Surgery Study
Group.
AB - BACKGROUND: For the surgical treatment of gastrooesophageal reflux disease
(GORD), laparoscopic Nissen fundoplication has largely replaced the open
procedure. Retrospective and prospective non-randomised studies have shown
similar results after laparoscopic Nissen fundoplication compared with the open
procedure. METHODS: In a multicentre randomised trial candidates for surgical
treatment of GORD were randomly assigned to either laparoscopic or open 360
degrees Nissen fundoplication. Primary endpoints were dysphagia, recurrent GORD,
and intrathoracic hernia. Secondary endpoints were effectiveness and quality of
life. This planned interim analysis focuses on endpoints and complications and in
hospital costs. FINDINGS: At the time of interim analysis, 11 patients in the
laparoscopic group and one in the conventional group had reached a primary
endpoint (p=0.01; relative risk=8.8, 95% CI 1.2-66.3). This difference was caused
mainly by whether or not patients had dysphagia (seven patients in the
laparoscopic group and none in the conventional group, p=0.016). INTERPRETATION:
Although laparoscopic Nissen fundoplication was as effective as the open
procedure in controlling reflux, the significantly higher risk of reaching a
primary endpoint in the laparoscopic group led us to stop the study.
PMID- 10675116
TI - Systolic blood pressure and mortality.
AB - BACKGROUND: The current systolic blood-pressure threshold for hypertension
treatment is 140 mm Hg for all adults. WHO and the International Society of
Hypertension have proposed that normal pressure be lower than 130 mm Hg, with an
optimum pressure of less than 120 mm Hg. These recommendations are based largely
on the assumption that cardiovascular and overall mortality depend in a strictly
increasing manner on systolic blood pressure. The Framingham study was
instrumental in establishing this viewpoint. We reassessed data from that study
to find out whether the relation is strictly increasing or whether there is a
threshold in this relation. METHODS: We used logistic splines to model the
relation of risk of cardiovascular and all-cause death with systolic blood
pressure, using age-specific and sex-specific rates. We tested for the
independence of the slope parameters from age and sex, and the reduced model with
common slopes was used to produce a model different from the conventional linear
logistic model. FINDINGS: Against the predictions of the linear logistic model,
neither all-cause nor cardiovascular deaths depended on systolic blood pressure
in a strictly increasing manner. The linear logistic model was rejected by the
Framingham data. Instead, risk was independent of systolic blood pressure for all
pressures lower than a threshold at the 70th percentile for a person of a given
age and sex. Risk sharply increased with pressure higher than the 80th
percentile. Since systolic blood pressure steadily increases with age, the
threshold increases with age, but more rapidly in women than in men.
INTERPRETATION: The Framingham data contradict the concept that lower pressures
imply lower risk and the idea that 140 mm Hg is a useful cut-off value for
hypertension for all adults. There is an age-dependent and sex-dependent
threshold for hypertension. A substantial proportion of the population who would
currently be thought to be at increased risk are, therefore, at no increased
risk.
PMID- 10675117
TI - Cost-effectiveness of public-funded options for cataract surgery in Mysore,
India.
AB - BACKGROUND: In India 3.8 million people become blind due to cataracts every year.
We assessed the cost-effectiveness of public-funded options for delivering
cataract surgery in Mysore, Karnataka State, India. METHODS: Three types of
delivery of cataract surgery were studied: mobile government camps, walk-in
services at a state medical college hospital, and patients transported in from
satellite clinics to a non-governmental hospital. We assessed outcomes in a
systematic sample of patients operated on in 1996-97 by follow-up at home;
average costs by provider derived from actual expenditures during the year.
FINDINGS: Almost half the patients operated on in government camps were
dissatisfied with the outcome (34/70, 49% [95% CI 36-61]). More than one third
were blind in the operated eye (25/70, 36% [25-48]). User satisfaction was higher
with other providers (medical college hospital 82% [63-94]; non-government
hospital 85% [72-93]), and fewer patients remained blind. Camps were a low-cost
option, but the poor outcomes reduced their cost-effectiveness to US$97 per
patient. The state medical college hospital was least cost-effective, at US$176
per patient, and the non-governmental hospital was the most cost-effective at
US$54 per patient. INTERPRETATION: The government of India should review its
policy for government camp surgery, and consider alternatives, such as
transporting patients to better permanent facilities. India and other developing
countries should monitor outcomes in cataract surgery programmes, as well as
throughput.
PMID- 10675118
TI - Effects of a clinical-practice guideline and practice-based education on
detection and outcome of depression in primary care: Hampshire Depression Project
randomised controlled trial.
AB - BACKGROUND: Depression is a major individual and public-health burden throughout
the world and is managed mainly in primary care. The most effective strategy to
reduce this burden has been believed to be education of primary-care
practitioners. We tested this assumption by assessing the effectiveness of an
educational programme based on a clinical-practice guideline in improving the
recognition and outcome of primary-care depression. METHODS: We carried out a
randomised controlled trial in a representative sample of 60 primary-care
practices (26% of the total) in an English health district. Education was
delivered to practice teams and quality tested by feedback from participants and
expert raters. The primary endpoints were recognition of depression, defined by
the hospital anxiety and depression (HAD) scale, and clinical improvement.
Analysis was by intention to treat. FINDINGS: The education was well received by
participants, 80% of whom thought it would change their management of patients
with depression. 21409 patients were screened, of whom 4192 were classified as
depressed by the HAD scale. The sensitivity of physicians to depressive symptoms
was 39% in the intervention group and 36% in the control group after education
(odds ratio 1.2 [95% CI 0.88-1.61]). The outcome of depressed patients as a whole
at 6 weeks or 6 months after the assessment did not significantly improve.
INTERPRETATION: Although well received, this in-practice programme, which was
designed to convey the current consensus on best practice for the care of
depression, did not deliver improvements in recognition of or recovery from
depression.
PMID- 10675119
TI - Reversion of prion protein conformational changes by synthetic beta-sheet breaker
peptides.
AB - BACKGROUND: Transmissible spongiform encephalopathies are associated with a
structural transition in the prion protein that results in the conversion of the
physiological PrPc to pathological PrP(Sc). We investigated whether this
conformational transition can be inhibited and reversed by peptides homologous to
the PrP fragments implicated in the abnormal folding, which contain specific
residues acting as beta-sheet blockers (beta-sheet breaker peptides). METHODS: We
studied the effect of a 13-residue beta-sheet breaker peptide (iPrP13) on the
reversion of the abnormal structure and properties of PrP(Sc) purified from the
brains of mice with experimental scrapie and from human beings affected by
sporadic and variant Creutzfeldt-Jakob disease. In a cellular model of familial
prion disease, we studied the effect of the peptide in the production of the
abnormal form of PrP in intact cells. The influence of the peptide on prion
infectivity was studied in vivo by incubation time assays in mice with
experimental scrapie. FINDINGS: The beta-sheet breaker peptide partly reversed in
vitro PrP(Sc) to a biochemical and structural state similar to that of PrPc. The
effect of the peptide was also detected in intact cells. Treatment of prion
infectious material with iPrP13 delayed the appearance of clinical symptoms and
decreased infectivity by 90-95% in mice with experimental scrapie.
INTERPRETATION: Beta-sheet breaker peptides reverse PrP conformational changes
implicated in the pathogenesis of spongiform encephalopathies. These peptides or
their derivatives provide a useful tool to study the role of PrP conformation and
might represent a novel therapeutic approach for prion-related disorders.
PMID- 10675120
TI - Fever and leucopenia with steroids.
PMID- 10675121
TI - Association between violence, psychosis, and relationship to victim in stalkers.
AB - 50 stalkers were assessed before their trials. Serious violence was significantly
associated with previous sexual intimacy between stalker and victim; such
stalkers were significantly less likely than those who stalked strangers to have
psychotic illness.
PMID- 10675122
TI - Failure of elimination of paternal mitochondrial DNA in abnormal embryos.
AB - Paternal mitochondrial DNA is normally eliminated from mammalian embryos. We have
shown the presence of paternal mtDNA at the blastocyst stage in some abnormal
human embryos.
PMID- 10675123
TI - Postural dependency of the cerebral venous outflow.
AB - We have shown that predominance of the jugular veins in cerebrovenous drainage is
limited to the supine position. In the erect position, the vertebral venous
system represents the major outflow pathway.
PMID- 10675124
TI - Measles in a Dutch hospital introduced by an immuno-compromised infant from
Indonesia infected with a new virus genotype.
AB - A fatal measles case in an immunocompromised Indonesian child was associated with
nosocomial transmission to health care workers. The virus isolated proved to
represent a new genotype within clade G.
PMID- 10675125
TI - Difference in nature of ruptured and unruptured cerebral aneurysms.
AB - Although small aneurysms have an extremely low probability of rupture, most
aneurysms that rupture are found to be less than 10 mm in diameter. Histological
study of aneurysms and epidemiological analysis of subarachnoid haemorrhage
revealed that ruptured and unruptured aneurysms are of a different nature.
PMID- 10675126
TI - Sexual origins of placental dysfunction.
AB - Severe placental dysfunction is much more common in pregnancies with a male than
with a female fetus. Furthermore, the birthweight/placental weight ratio is
increased in these pregnancies, consistent with fetal growth restriction, and is
higher with a male fetus than with a female fetus. These observations of
placental insufficiency may underlie the increased in-utero loss rate of male
fetuses.
PMID- 10675127
TI - Diphtheria in urban slums in north India.
AB - We recorded a reappearance of cases of microbiologically confirmed diphtheria in
a tertiary care hospital in north India. Poor immunisation coverage, population
migrations, and overcrowded urban slums may be contributory factors.
PMID- 10675128
TI - Embryo splitting produces primate "clone"
PMID- 10675129
TI - Osteoarthritis research: on the verge of a revolution?
PMID- 10675130
TI - Japan puts the rights of the disabled into the spotlight.
PMID- 10675131
TI - Agency warns of crisis in beleaguered Democratic Republic of Congo.
PMID- 10675132
TI - USA spearheads renewed efforts to combat AIDS.
PMID- 10675133
TI - Cardiovascular gene therapy.
AB - Vascular gene transfer potentially offers new treatments for cardiovascular
diseases. It can be used to overexpress therapeutically important proteins and
correct genetic defects, and to test experimentally the effects of various genes
in a local vascular compartment. Vascular endothelial growth factor (VEGF) and
fibroblast growth factor (FGF) gene transfers have improved blood flow and
collateral development in ischaemic limb and myocardium. Promising therapeutic
effects have been obtained in animal models of restenosis or vein-graft
thickening with the transfer of genes coding for VEGF, nitric-oxide synthase,
thymidine kinase, retinoblastoma, growth arrest homoeobox, tissue inhibitor of
metalloproteinases, cyclin or cyclin-dependent kinase inhibitors, fas ligand and
hirudin, and antisense oligonucleotides against transcription factors or cell
cycle regulatory proteins. First experiences of VEGF gene transfer and decoy
oligonucleotides in human beings have been reported. However, further
developments in gene-transfer vectors, gene-delivery techniques and
identification of effective treatment genes will be required before the full
therapeutic potential of gene therapy in cardiovascular disease can be assessed.
PMID- 10675134
TI - Death by decree.
PMID- 10675135
TI - Mild cognitive impairment: conceptual basis and current nosological status.
PMID- 10675136
TI - Minor-injury care by nurse practitioners or junior doctors.
PMID- 10675137
TI - Minor-injury care by nurse practitioners or junior doctors.
PMID- 10675138
TI - Minor-injury care by nurse practitioners or junior doctors.
PMID- 10675139
TI - Minor-injury care by nurse practitioners or junior doctors.
PMID- 10675140
TI - Minor-injury care by nurse practitioners or junior doctors.
PMID- 10675141
TI - Glaucoma and paclitaxel.
PMID- 10675142
TI - Screening for congenital dislocation of the hip.
PMID- 10675143
TI - Screening for congenital dislocation of the hip.
PMID- 10675144
TI - Acute vestibulopathy.
PMID- 10675145
TI - Chronic pain.
PMID- 10675146
TI - Y chromosome.
PMID- 10675147
TI - Lowering of LDL cholesterol.
PMID- 10675148
TI - Prophylaxis against respiratory syncytial virus in premature infants.
PMID- 10675149
TI - Chagas' disease challenge.
PMID- 10675150
TI - Neutral protamine Hagedorn insulin.
PMID- 10675151
TI - Renal effects of cyclo-oxygenase-type-2 inhibition.
PMID- 10675152
TI - Self-use of rapid tests for malaria diagnosis.
PMID- 10675153
TI - Self-use of rapid tests for malaria diagnosis.
PMID- 10675154
TI - Extreme potency of botulinum toxin.
PMID- 10675155
TI - Tobacco and health-care professionals in Japan.
PMID- 10675156
TI - Pathological laughing and crying.
PMID- 10675157
TI - Ethics of intensive neonatal care.
PMID- 10675158
TI - Assessment of nationwide cancer-screening programmes.
PMID- 10675159
TI - Maternal blood pressure and birthweight.
PMID- 10675160
TI - Development of practice guidelines.
PMID- 10675161
TI - Should staff in long-stay hospitals for elderly patients be vaccinated against
influenza?
PMID- 10675162
TI - Might olfactory dysfunction be a marker of early Alzheimer's disease?
PMID- 10675163
TI - Strategy after diagnosis of pancreatic dysplasia.
PMID- 10675164
TI - Fall in mean arterial pressure and fetal growth restriction in pregnancy
hypertension: a meta-analysis.
AB - BACKGROUND: We investigated the relation between fetoplacental growth and the use
of oral antihypertensive medication to treat mild-to-moderate pregnancy
hypertension. METHODS: The study design was a metaregression analysis of
published data from randomised controlled trials. Data from a paper that was
regarded as an extreme statistical outliner were excluded from primary analyses.
The change in (group) mean arterial pressure (MAP) from enrolment to delivery was
compared with indicators of fetoplacental growth. FINDINGS: Greater mean
difference in MAP with antihypertensive therapy was associated with the birth of
a higher proportion of small-for-gestational-age (SGA) infants (slope: 0.09 [SD
0.03], r2=0.48, p=0.006, 14 trials) and lower mean birthweight significant after
exclusion of data from another paper regarded as an extreme statistical outliner
(slope: -14.49 [6.98] r=0.16, p=0.049, 27). No relation with mean placental
weight was seen (slope -2.01 [1.62], r2=0.15, p=0.25, 11 trials). INTERPRETATION:
Treatment-induced falls in maternal blood pressure may adversely affect fetal
growth. Given the small maternal benefits that are likely to be derived from
therapy, new data are urgently needed to elucidate the relative maternal and
fetal benefits and risks of oral antihypertensive drug treatment of mild-to
moderate pregnancy hypertension.
PMID- 10675165
TI - Effects of influenza vaccination of health-care workers on mortality of elderly
people in long-term care: a randomised controlled trial.
AB - BACKGROUND: Vaccination of health-care workers has been claimed to prevent
nosocomial influenza infection of elderly patients in long-term care. Data are,
however, limited on this strategy. We aimed to find out whether vaccination of
health-care workers lowers mortality and the frequency of virologically proven
influenza in such patients. METHODS: In a parallel-group study, health-care
workers in 20 long-term elderly-care hospitals (range 44-105 patients) were
randomly offered or not offered influenza vaccine (cluster randomisation,
stratified for policy for vaccination of patients and hospital size). All deaths
among patients were recorded over 6 months in the winter of 1996-97. We selected
a random sample of 50% of patients for virological surveillance for influenza,
with combined nasal and throat swabs taken every 2 weeks during the epidemic
period. Swabs were tested by tissue culture and PCR for influenza viruses A and
B. FINDINGS: Influenza vaccine uptake in health-care workers was 50.9% in
hospitals in which they were routinely offered vaccine, compared with 4.9% in
those in which they were not. The uncorrected rate of mortality in patients was
102 (13.6%) of 749 in vaccine hospitals compared with 154 (22.4%) of 688 in no
vaccine hospitals (odds ratio 0.58 [95% CI 0.40-0.84], p=0.014). The two groups
did not differ for proportions of patients positive for influenza infection (5.4%
and 6.7%, respectively); at necropsy, PCR was positive in none of 17 patients
from vaccine hospitals and six (20%) of 30 from no-vaccine hospitals (p=0.055).
INTERPRETATION: Vaccination of health-care workers was associated with a
substantial decrease in mortality among patients. However, virological
surveillance showed no associated decrease in non-fatal influenza infection in
patients.
PMID- 10675166
TI - Effect of pelvic-floor re-education on duration and degree of incontinence after
radical prostatectomy: a randomised controlled trial.
AB - BACKGROUND: Urinary incontinence is a common long-term complication after radical
prostatectomy. Spontaneous recovery of normal urinary control after surgery can
take 1-2 years. We aimed to investigate whether there was any beneficial effect
of pelvic-floor re-education for patients with urinary incontinence as a result
of radical prostatectomy. METHODS: 102 consecutive incontinent patients who had
had radical retropubic prostatectomy for clinically localised prostate cancer and
who could comply with the ambulatory treatment schedule in our hospital were
randomised, after catheter removal, into a treatment group (n=50) and a control
group (n=52). Patients in the treatment group took part in a pelvic-floor re
education programme for as long as they were incontinent, and for a maximum of 1
year. The control group received placebo therapy. The primary endpoint was
continence rate at 3 months. Incontinence was assessed objectively with the 1 h
and 24 h pad tests and subjectively by the visual analogue scale. The groups were
analysed on an intention-to-treat basis by ANOVA and chi2-test. FINDINGS: In the
treatment group continence was achieved after 3 months in 43 (88%) of 48
patients. In the control group, continence returned after 3 months in 29 (56%) of
52 patients. At 1 year, the difference in proportion between treatment and
control group was 14% (95% CI 2-27). In the treatment group improvement in both
duration (log-rank test, p=0.0001) and degree of incontinence (Wald test,
p=0.0010) was significantly better than in the control group. INTERPRETATION:
Pelvic-floor re-education should be considered as a first-line option in curing
incontinence after radical prostatectomy.
PMID- 10675167
TI - Practice guidelines developed by specialty societies: the need for a critical
appraisal.
AB - BACKGROUND: There is increasing concern about the quality, reliability, and
independence of practice guidelines. Because no information is available on the
methodological quality of the guidelines developed by specialty societies, we
undertook a survey on those published in peer-reviewed journals. METHODS:
Practice guidelines produced by specialty societies and published in English
between January, 1988, and July, 1998, where identified through MEDLINE. Their
quality was assessed in terms of whether they reported: the type of professionals
and stakeholders involved in the development process; the strategy to identify
primary evidence; and an explicit grading of recommendations according to the
quality of supporting evidence. FINDINGS: Overall, 431 guidelines were eligible
for the study. Most did not meet the criteria: 67% did not report any description
of the type of stakeholders, 88% gave no information on searches for published
studies, and 82% did not give any explicit grading of the strength of
recommendations. There was improvement over time for searches (from 2% to 18%,
p<0.001) and explicit grading of evidence (from 6% to 27%, p<0.001). All three
criteria for quality were met in only 22 (5%) guidelines. INTERPRETATION: Despite
improvement over time, the quality of practice guidelines developed by specialty
societies is unsatisfactory. Explicit methodological criteria for the production
of guidelines shared among public agencies, scientific societies, and patients'
associations need to be set up. Common standards of reporting, following the same
principles that led to the CONSORT statement for randomised clinical trials,
should be promoted.
PMID- 10675168
TI - Classification of thyroid size by palpation and ultrasonography in field surveys.
AB - BACKGROUND: Goitre surveys are used to assess the degree of iodine deficiency in
a population. The change of goitre classification made by WHO in 1994 implied
that a smaller thyroid size should be regarded as goitre. Furthermore, the
acceptable goitre prevalence was lowered from 10% to 5%, and ultrasonography was
recommended as a more precise method for diagnosis of goitre. We studied the
effects of the change of palpation system, and compared the precision of the old
and new systems with that of ultrasonographic examination. METHODS: We studied
225 schoolchildren (aged 7-14 years) in a highland village in Tanzania. The size
of the thyroid was assessed in duplicate by ultrasonography and by WHO's 1960 and
1994 palpation systems. The latter were done by three examiners. Variations
within and between examination methods and examiners were assessed, and
measurement errors by ultrasonography were assessed from duplicate examinations.
The sensitivity and specificity of the two palpation systems were calculated,
with diagnosis by ultrasonography as the gold standard. Apparent palpation
prevalences were calculated at a "true" 5% prevalence. FINDINGS: The lowered
criterion for goitre resulted in an extra 20-33% of children being diagnosed as
having goitre by palpation. The variation between repeat examinations was only
slightly smaller by ultrasonography (kappa=0.63) than by experienced examiners
(kappa=0.57-0.58). The variation between thyroid volume estimation by
ultrasonography and the true volume was about 50% due to both measurement error
and variation in the shape of thyroid lobes. The new goitre criterion decreased
specificity from 76% to 29%, whereas sensitivity rose from 56% to 80%. In
contrast, a suggested sharpening of the old criterion increased specificity to
90%. INTERPRETATION: A return to the old (1960) palpation criterion for goitre:
"lobes larger than the terminal phalanxes of thumbs" and to an accepted palpation
goitre prevalence of 10% can allow affordable monitoring of thyroid size through
palpation in field surveys.
PMID- 10675169
TI - Epidemiological and diagnostic aspects of the outbreak of pneumonic plague in
Madagascar.
AB - BACKGROUND: Plague is a re-emerging disease and pneumonic plague is the most
feared clinical form. We describe a well-documented outbreak of pneumonic plague
in Madagascar. METHODS: Field epidemiological data were collected. Biological
tests (microscopy, culture of Yersinia pestis, F1 antigen ELISA and dipstick
assays, IgG anti-F1 ELISA) were done on sputum, serum, or necropsy samples. The
infection rate among 154 contacts was assessed by anti-F1 serological techniques.
FINDINGS: The index case was a bubonic patient with a secondary lung infection,
who contaminated a traditional healer and his family. Funeral ceremonies and
attendance on patients contaminated other villagers. In total 18 cases were
recorded, and eight died. F1 antigen could be detected in sputum by ELISA and
dipstick tests as early as the second day after the onset of the symptoms and
also 48 h after treatment. Among the contact population 13 of 154 (8.4%) have
been exposed to the plague bacillus (symptomless or latent infections).
INTERPRETATION: The F1 dipstick assay on sputum is an invaluable diagnostic tool
for pneumonic plague. Treatment of patients and chemoprophylaxis of contacts were
efficient in stopping the epidemic.
PMID- 10675170
TI - A cause of pre-eclampsia?
PMID- 10675171
TI - Identification by positron emission tomography of neuronal loss in acute
vegetative state.
AB - Positron emission tomography with the benzodiazepine receptor ligand carbon-11
labelled flumazenil Identified the extent of neuronal damage in acute vegetative
state and predicted the possibility of recovery of consciousness and function.
PMID- 10675172
TI - Three-dimensional ultrasonography: new prospects for ultrasound imaging of bone.
AB - Radiography is used for the initial evaluation of suspected bone lesions. We have
shown that surface images of bone can be obtained by three-dimensional
ultrasonography.
PMID- 10675173
TI - Neutropenia among survivors of atomic bomb explosion.
AB - High incidence of neutropenia was found among atomic bomb survivors. We showed
that the cause of neutropenia was due to NK or NK-like T-cell proliferative
disorders, diagnosed by immunophenotypic, functional, and DNA analysis.
PMID- 10675174
TI - Community-based study of genital schistosomiasis in men from Madagascar.
AB - Detection of Schistosoma haematoblum eggs in 43% of semen samples with Increased
levels of eosinophil cationic protein suggests that the genital organs of men are
frequently affected with schistosomiasis.
PMID- 10675176
TI - Mode of delivery and subsequent stress response.
AB - We have shown that a baby's stress (saliva cortisol) and crying response to
inoculation at 8 weeks was related to mode of delivery, with the greatest
response shown in those born by assisted delivery and the least response in those
born by elective caesarean section.
PMID- 10675175
TI - Risk of congenital malformations associated with treatment of asthma during early
pregnancy.
AB - Studies assessing the risk of congenital malformations associated with the
treatment of asthma during the first trimester of pregnancy are few, have limited
power and support continuation of treatment.
PMID- 10675178
TI - Drug-pricing "powder keg" stirs up US health-care politics.
PMID- 10675177
TI - Work-related stress: can it be a thing of the past?
PMID- 10675179
TI - Fresh allegations levelled at Toronto paediatrician.
PMID- 10675180
TI - Concern grows about adolescent pregnancy in Cape Verde.
PMID- 10675181
TI - Is screening for breast cancer with mammography justifiable?
AB - BACKGROUND: A 1999 study found no decrease in breast-cancer mortality in Sweden,
where screening has been recommended since 1985. We therefore reviewed the
methodological quality of the mammography trials and an influential Swedish meta
analysis, and did a meta-analysis ourselves. METHODS: We searched the Cochrane
Library for trials and asked the investigators for further details. Meta-analyses
were done with Review Manager (version 4.0). FINDINGS: Baseline imbalances were
shown for six of the eight identified trials, and inconsistencies in the number
of women randomised were found in four. The two adequately randomised trials
found no effect of screening on breast-cancer mortality (pooled relative risk
1.04 [95% CI 0.84-1.27]) or on total mortality (0.99 [0.94-1.05]). The pooled
relative risk for breast-cancer mortality for the other trials was 0.75 (0.67
0.83), which was significantly different (p=0.005) from that for the unbiased
trials. The Swedish meta-analysis showed a decrease in breast-cancer mortality
but also an increase in total mortality (1.06 [1.04-1.08]); this increase
disappeared after adjustment for an imbalance in age. INTERPRETATION: Screening
for breast cancer with mammography is unjustified. If the Swedish trials are
judged to be unbiased, the data show that for every 1000 women screened
biennially throughout 12 years, one breast-cancer death is avoided whereas the
total number of deaths is increased by six. If the Swedish trials (apart from the
Malmo trial) are judged to be biased, there is no reliable evidence that
screening decreases breast-cancer mortality.
PMID- 10675182
TI - Herb-drug interactions.
AB - Concurrent use of herbs may mimic, magnify, or oppose the effect of drugs.
Plausible cases of herb-drug interactions include: bleeding when warfarin is
combined with ginkgo (Ginkgo biloba), garlic (Allium sativum), dong quai
(Angelica sinensis), or danshen (Salvia miltiorrhiza); mild serotonin syndrome in
patients who mix St John's wort (Hypericum perforatum) with serotonin-reuptake
inhibitors; decreased bioavailability of digoxin, theophylline, cyclosporin, and
phenprocoumon when these drugs are combined with St John's wort; induction of
mania in depressed patients who mix antidepressants and Panax ginseng;
exacerbation of extrapyramidal effects with neuroleptic drugs and betel nut
(Areca catechu); increased risk of hypertension when tricyclic antidepressants
are combined with yohimbine (Pausinystalia yohimbe); potentiation of oral and
topical corticosteroids by liquorice (Glycyrrhiza glabra); decreased blood
concentrations of prednisolone when taken with the Chinese herbal product xaio
chai hu tang (sho-salko-to); and decreased concentrations of phenytoin when
combined with the Ayurvedic syrup shankhapushpi. Anthranoid-containing plants
(including senna [Cassia senna] and cascara [Rhamnus purshiana]) and soluble
fibres (including guar gum and psyllium) can decrease the absorption of drugs.
Many reports of herb-drug interactions are sketchy and lack laboratory analysis
of suspect preparations. Health-care practitioners should caution patients
against mixing herbs and pharmaceutical drugs.
PMID- 10675183
TI - On the other side of the tracks.
PMID- 10675184
TI - Unrecognised Mycobacterium tuberculosis.
PMID- 10675185
TI - Unrecognised Mycobacterium tuberculosis.
PMID- 10675186
TI - Unrecognised Mycobacterium tuberculosis.
PMID- 10675187
TI - Unrecognised Mycobacterium tuberculosis.
PMID- 10675188
TI - Contact-lens-associated microbial keratitis in The Netherlands and Scotland.
PMID- 10675189
TI - Immunohistochemical detection of lymph-node metastases.
PMID- 10675190
TI - Immunohistochemical detection of lymph-node metastases.
PMID- 10675191
TI - Soluble thrombomodulin in hypercholesterolaemic patients.
PMID- 10675192
TI - Adenovirus in EV71-associated hand, foot, and mouth disease.
PMID- 10675193
TI - Adenovirus in EV71-associated hand, foot, and mouth disease.
PMID- 10675194
TI - Cluster headache and melatonin.
PMID- 10675195
TI - Folate supplementation and neural-tube defects.
PMID- 10675196
TI - Insulin-like growth factor I for growth hormone therapy.
PMID- 10675197
TI - Oral cobalamin therapy.
PMID- 10675198
TI - After postmodernism.
PMID- 10675199
TI - After postmodernism.
PMID- 10675200
TI - European role in global cardiology.
PMID- 10675201
TI - Game plan for cancer care.
PMID- 10675202
TI - John Lykoudis and peptic ulcer disease.
PMID- 10675204
TI - Vasculitic neuropathies.
PMID- 10675203
TI - The role of the delayed rectifier component IKs in dog ventricular muscle and
Purkinje fibre repolarization.
AB - 1. The relative contributions of the rapid and slow components of the delayed
rectifier potassium current (IKr and IKs, respectively) to dog cardiac action
potential configuration were compared in ventricular myocytes and in
multicellular right ventricular papillary muscle and Purkinje fibre preparations.
Whole-cell patch-clamp techniques, conventional microelectrode and in vivo ECG
measurements were made at 37C. 2. Action potential duration (APD) was minimally
increased (less than 7%) by chromanol 293B (10 microM) and L-735,821 (100 nM),
selective blockers of IKs, over a range of pacing cycle lengths (300-5000 ms) in
both dog right ventricular papillary muscles and Purkinje fibre strands. D
Sotalol (30 microM) and E-4031 (1 microM), selective blockers of IKr, in the same
preparations markedly (20-80%) lengthened APD in a reverse frequency-dependent
manner. 3. In vivo ECG recordings in intact anaesthetized dogs indicated no
significant chromanol 293B (1 mg kg-1 i.v.) effect on the QTc interval (332.9 +/-
16.1 ms before versus 330.5 +/- 11.2 ms, n = 6, after chromanol 293B), while D
sotalol (1 mg kg-1 i.v.) significantly increased the QTc interval (323.9 +/- 7.3
ms before versus 346.5 +/- 6.4 ms, n = 5, after D-sotalol, P < 0.05). 4. The
current density estimated during the normal ventricular muscle action potential
(i.e. after a 200 ms square pulse to +30 mV or during a 250 ms long 'action
potential-like' test pulse) indicates that substantially more current is
conducted through IKr channels than through IKs channels. However, if the
duration of the square test pulse or the 'action potential-like' test pulse was
lengthened to 500 ms the relative contribution of IKs significantly increased. 5.
When APD was pharmacologically prolonged in papillary muscle (1 microM E-4031 and
1 microg ml-1 veratrine), 100 nM L-735,821 and 10 microM chromanol 293B
lengthened repolarization substantially by 14.4 +/- 3.4 and 18. 0 +/- 3.4% (n =
8), respectively. 6. We conclude that in this study IKs plays little role in
normal dog ventricular muscle and Purkinje fibre action potential repolarization
and that IKr is the major source of outward current responsible for initiation of
final action potential repolarization. Thus, when APD is abnormally increased,
the role of IKs in final repolarization increases to provide an important safety
mechanism that reduces arrhythmia risk.
PMID- 10675205
TI - Responsiveness of outcome measures in randomised controlled trials in neurology.
PMID- 10675206
TI - Corticobasal degeneration.
PMID- 10675207
TI - Pattern of dopaminergic loss in the striatum of humans with parkinsonism induced
by MPTP.
PMID- 10675208
TI - Neurological emergencies: acute stroke.
AB - Stroke causes a vast amount of death and disability throughout the world, yet for
many healthcare professionals it remains an area of therapeutic nihilism, and
thus uninteresting. This negative perception is shared by the general public, who
often have a poor understanding of the early symptoms and significance of a
stroke. Yet within the past few years there have been many important developments
in the approach to caring for stroke patients, for both the acute management and
secondary prevention. After the completion of numerous clinical trials, there is
now robust evidence to either support or discredit various interventions. Even
more exciting is the prospect of yet more data becoming available in the near
future, testing a whole array of treatments, as clinical interest in stroke
expands exponentially. In this review an evidence based approach to the
management of acute stroke within the first few days is presented, including
ischaemic and haemorrhagic events, but not subarachnoid haemorrhage. It is
explained why stroke is regarded as a medical emergency, and the importance of a
rational, methodic approach to the initial assessment, which is the key to
accurate diagnosis and subsequent management, is emphasised. The potential early
problems associated with stroke are identified and specific interventions for
different stroke types are discussed. The review ends with a brief discussion of
the implications that the evolving treatments have for the organisation of modern
stroke services.
PMID- 10675209
TI - Tuberculous meningitis.
PMID- 10675210
TI - Role of clinical, radiological, and neurophysiological changes in predicting the
outcome of tuberculous meningitis: a multivariable analysis.
AB - OBJECTIVES: The role of EEG and evoked potentials has not been evaluated in
predicting the prognosis of tuberculous (TB) meningitis. The present study was
aimed at evaluating the prognostic significance of clinical, radiological, and
neurophysiological variables using multi-variable analysis. METHODS: Patients
with TB meningitis diagnosed on the basis of clinical, radiological, and CSF
criteria have been prospectively evaluated. All the patients were subjected to a
detailed neurological evaluation. The outcome was defined 6 months after starting
treatment on the basis of the Barthel index (BI) score into poor (BI <12) and
good recovery (BI> or =12). Death was included in the poor recovery group for
statistical analysis. Thirteen clinical (age, sex, seizure, focal weakness, stage
of meningitis, Glasgow coma scale score, methyl prednisolone therapy), CT
(infarction, hydrocephalus, tuberculoma) and neurophysiological (EEG, motor and
somatosensory evoked potentials) variables were evaluated employing single
variable logistic regression followed by multivariable logistic regression
analysis. The best set of predictors were obtained by stepdown logistic
regression analysis. RESULTS: Fifty four patients were included in the present
study. Their age ranged between 5 and 62 years, 11 were children younger than 12
years and 14 were female. Nine patients were in stage I meningitis, 12 in stage
II, and 33 in stage III. On single variable logistic regression analysis the
significant predictors of 6 months outcome of TB meningitis included focal
weakness, Glasgow coma scale (GCS), motor evoked potential (MEP) and
somatosensory evoked potential (SEP). On multivariable analysis the best set of
predictors comprised focal weakness, GCS, and SEP. CONCLUSIONS: In patients with
TB meningitis focal weakness, GCS, and SEP are the best predictors of 6 month
outcome.
PMID- 10675211
TI - Corticobasal ganglionic degeneration and/or frontotemporal dementia? A report of
two overlap cases and review of literature.
AB - OBJECTIVE: According to the existing viewpoint, Corticobasal degeneration (CBD)
is thought of as a predominantly extrapyramidal motor disorder that is distinct
and unrelated to frontotemporal dementia (FTD), the most common form of non
Alzheimer dementias. A lack of understanding of the aetiopathogenesis, and poor
correlation between the pathology and the clinical syndromes, has resulted in a
disparity in the classification of cases of non-Alzheimer dementias. This report
intends to highlight the overlap between FTD and CBD in the light of the
evolution of these terms, and to discuss the implications of these findings on
the nosology of CBD and the classification of non-Alzheimer dementias. METHODS
AND RESULTS: Two cases who presented with cognitive dysfunction, which, on
comprehensive neuropsychological testing warranted an antemortem diagnosis of FTD
are reported. A detailed necropsy study of their brains, however, favoured a
pathological diagnosis of CBD. The literature on the overlap between CBD and FTD
is also reviewed. CONCLUSIONS: Firstly, evidence is emerging to suggest that the
clear distinction drawn between FTD and CBD by the existing viewpoint, needs
revision. Secondly, until such time that a comprehensive classification of non
Alzheimer dementias is evolved, it may be better to distinguish between the
clinical and pathological levels of description and to classify cases, in vivo,
on the basis of the clinical phenotype.
PMID- 10675212
TI - Pattern of dopaminergic loss in the striatum of humans with MPTP induced
parkinsonism.
AB - OBJECTIVES: To examine the distribution of striatal dopaminergic function in
humans with parkinsonism induced by 1-methyl-4-phenyl-1, 2,3,6-tetrahydropyridine
(MPTP) to determine if there is a caudate-putamen gradient as is seen in
idiopathic Parkinson's disease. METHODS: We scanned nine humans exposed to MPTP
with parkinsonism ranging from minimal to severe using [(18)F]fluorodopa (FD) and
high resolution PET. The results were compared with those of 10 patients with
Parkinson's disease and six normal subjects. RESULTS: In the MPTP group there was
an equal degree of reduction of dopaminergic function in the caudate and putamen.
This was different from the greater putaminal than caudate loss in Parkinson's
disease (p<0.001). CONCLUSIONS: Parkinson's disease is not caused by transient
exposure to MPTP.
PMID- 10675213
TI - Atrophy of the corpus callosum associated with a decrease in cortical
benzodiazepine receptor in large cerebral arterial occlusive diseases.
AB - OBJECTIVES: It remains controversial whether selective neuronal ischaemic change
develops in patients with occlusion of the large cerebral arteries. Previous
studies have shown atrophy of the corpus callosum with reduced cortical oxygen
metabolism in large cerebral arterial occlusive diseases, which might be indirect
evidence of loss of the neurons in cortical layer 3. Recent studies of patients
with ischaemic cerebrovascular diseases have demonstrated reduced central
benzodiazepine receptor (BZR) binding in the normal appearing cortical areas,
which might be more direct evidence of changes of the neurons. Although
pathophysiology of the decreased BZR is unclear, a decrease in the cortical BZR
binding with neuronal loss would cause atrophy of the corpus callosum. The
purpose of this study was to determine whether atrophy of the corpus callosum is
associated with a decrease in cortical BZR binding in large cerebral arterial
occlusive diseases. METHODS: Seven patients with occlusive diseases of the middle
cerebral or internal carotid artery and only minor subcortical infarctions were
studied. Single photon emission tomographic images of (123)I labelled iomazenil
(IMZ) obtained 180 minutes after injection were analysed for BZR binding. The
midsagittal corpus callosum area/skull area ratio (on T1 weighted magnetic
resonance images) was compared with the cerebral IMZ uptake/cerebellar IMZ uptake
ratio. RESULTS: Compared with 23 age and sex matched control subjects, the
patients had significantly decreased callosal area/skull area ratio. The degree
of corpus callosum atrophy was significantly and strongly (rho=0.99, p<0.02)
correlated with that of the decreases in the mean cerebral cortical IMZ uptake
ratio. CONCLUSION: Corpus callosum atrophy may occur in association with a
decrease in cortical BZR binding in large cerebral arterial occlusive diseases.
Corpus callosum atrophy with decreased cortical BZR binding might reflect
cortical neuronal damage in large cerebral arterial occlusive diseases.
PMID- 10675214
TI - Value of somatosensory and motor evoked potentials in predicting arm recovery
after a stroke.
AB - OBJECTIVES: Prediction of motor recovery in the arm in patients with stroke is
generally based on clinical examination. However, neurophysiological measures may
also have a predictive value. The aims of this study were to assess the role of
somatosensory (SSEPs) and motor (MEPs) evoked potentials in the prediction of arm
motor recovery and to determine whether these measures added further predictive
information to that gained from clinical examination. METHODS: Sixty four
patients who had had a stroke and presented with obvious motor deficit of the arm
were examined in terms of three clinical variables (motor performance, muscle
tone, and overall disability) and for SSEPs and MEPs. Clinical and
neurophysiological examinations were done at entry to the study (2 to 5 weeks
poststroke), and at about 2 months after stroke. Further clinical follow up was
conducted at 6 and 12 months after stroke. RESULTS: Neurophysiological measures
made in the acute phase were of little use alone in predicting motor recovery of
the arm at 2, 6, and 12 months after stroke. At 2 months, the absence of SSEPs
and MEPs indicated a very poor outcome. Conversely, if the responses were
preserved, a great variation in motor outcome was found. Multiple regression
analysis showed that the addition of SSEPs and MEPs to the clinical examination
increased the possibility of predicting arm recovery in the long term. In the
acute phase, the combination of the motor score and SSEPs were best able to
predict outcome. The long term outcome based on variables taken at 2 months, was
best predicted through incorporating the three clinical measures and MEPs.
CONCLUSIONS: Neurophysiological measures alone are of limited value in predicting
long term outcome. However, predictive accuracy is substantially improved through
the combined use of both of these measures and clinical variables.
PMID- 10675215
TI - The notion of "warning leaks" in subarachnoid haemorrhage: are such patients in
fact admitted with a rebleed?
AB - OBJECTIVE: Often patients with subarachnoid haemorrhage (SAH) recall a recent
episode of acute severe headache, usually interpreted as a "warning headache" or
first SAH. An alternative explanation is recall bias. The clinical and
radiological features of patients with SAH were studied in relation to previous
headaches or later rebleeding. METHODS: Patients with either a previous headache
episode or a subsequent rebleed were selected from the SAH database in Utrecht
within 1 month of the index SAH. The clinical condition was graded on the World
Federation of Neurological Surgeons (WFNS) scale. The CT was reviewed and the
amounts of subarachnoid blood, hydrocephalus, and intraventricular,
intracerebral, and subdural blood were rated. Proportions were compared by
unpaired or paired t test. RESULTS: Forty four of 390 patients (11%) had had a
severe headache before their index SAH (11 of these had a subsequent rebleed); 31
other patients had a rebleed in hospital but no preceding headache. Patients with
and without preceding headache did not differ in level of consciousness (14 of 44
v 11 of 31 were comatose), nor in any of the radiological features. After
rebleeding (42 patients), 37 of 42 patients were comatose (v 11 of 42 before),
and CT showed higher proportions of intracerebral haemorrhage (17%),
intraventricular haemorrhage, (27%), and hydrocephalus (12%) than baseline scans.
Intraventricular haemorrhage was twice as frequent after rebleeding than at
baseline. CONCLUSIONS: The clinical and radiological features of patients
admitted with SAH after a preceding bout of headache did not differ from those
without such an episode, and are clearly dissimilar from those after documented
rebleeds. The findings challenge the existence of minor "warning headaches".
PMID- 10675216
TI - Complications and outcome in patients with aneurysmal subarachnoid haemorrhage: a
prospective hospital based cohort study in the Netherlands.
AB - OBJECTIVE: The aim of this study was to investigate prospectively in an
unselected series of patients with an aneurysmal subarachnoid haemorrhage what at
present the complications are, what the outcome is, how many of these patients
have "modern treatment"-that is, early obliteration of the aneurysm and treatment
with calcium antagonists-what factors cause a delay in surgical or endovascular
treatment, and what the estimated effect on outcome will be of improved
treatment. METHODS: A prospective, observational cohort study of all patients
with aneurysmal subarachnoid haemorrhage in the hospitals of a specified region
in The Netherlands. The condition on admission, diagnostic procedures, and
treatments were recorded. If a patient had a clinical deterioration, the change
in Glasgow coma score (GCS), the presence of focal neurological signs, the
results of additional investigations, and the final diagnosed cause of the
deterioration were recorded. Clinical outcome was assessed with the Glasgow
outcome scale (GOS) at 3 month follow up. In patients with poor outcome at follow
up, the cause was diagnosed. RESULTS: Of the 110 patients, 47 (43%) had a poor
outcome. Cerebral ischaemia, 31 patients (28%), was the most often occurring
complication. Major causes of poor outcome were the effects of the initial
haemorrhage and rebleeding in 34% and 30% of the patients with poor outcome
respectively. Of all patients 102 (93%) were treated with calcium antagonists and
45 (41%) patients had early treatment to obliterate the aneurysm. The major
causes of delay of treatment were a poor condition on admission or deterioration
shortly after admission, in 31% and 23% respectively. CONCLUSIONS: In two thirds
of the patients with poor outcome the causes of poor outcome are the effects of
the initial bleeding and rebleeding. Improved treatment of delayed or
postoperative ischaemia will have only minor effects on the outcome of patients
with subarachnoid haemorrhage.
PMID- 10675218
TI - Alzheimer's disease.
PMID- 10675217
TI - Validity of carbohydrate deficient transferrin and other markers as diagnostic
aids in the detection of alcohol related seizures.
AB - OBJECTIVE: The role of alcohol misuse in the genesis of seizures is probably
often undetected. The aim was to investigate the utility of carbohydrate
deficient transferrin (CDT) compared with other biomarkers and clinical
examination in the diagnosis of alcohol related seizures. METHODS: The study
included consecutively 158 seizure patients-83 men and 75 women-with mean age 45
(16-79) years. Seizures related to alcohol use were identified by a score > or =8
in the alcohol use disorders identification test (AUDIT positive). AUDIT was
applied as the gold standard to which sensitivity and specificity of the various
markers were related. Blood samples were obtained from 150 patients on admission
and analysed for ethanol, liver enzymes, and CDT, using AXIS Biochemicals' %CDT
TIA kit. RESULTS: 53 patients (34%) were AUDIT positive. Using the commonly
applied decision value for %CDT of 5.0%, a sensitivity of 41% and a specificity
of 84% were obtained. Analysis of receiver operator characteristics (ROC) curves
disclosed an optimal cut off value for %CDT of 5.4%, which yielded a sensitivity
of 39% and a specificity of 88%. At a specificity of 80%, the sensitivity was 43%
for %CDT and 26% for GGT. The %CDT sensitivity was markedly higher for men than
for women. Compared with GGT, ASAT, ALAT, and ASAT/ALAT ratio, CDT was the best
single biomarker for alcohol related seizures. However, even in the subgroup of
withdrawal seizures, the sensitivity level barely exceeded 50%. Clinicians scored
alcohol as the main cause of the seizure in only 19 cases (12%). In 38 (24%)
cases, clinicians suspected that alcohol had a role (sensitivity of 62% at a
specificity of 89%). Their ability to identify AUDIT positive patients was better
than that of any biomarker, but many cases were missed. Agreement of clinicians'
scores to CDT was only fair (kappa=0.28). CDT concentrations were significantly
increased among alcohol abstaining patients on enzyme-inducing antiepileptic
drugs. Six out of 16 patients with false positive CDT results were exposed to
such drugs. CONCLUSIONS: CDT is not recommended as a stand alone marker for
alcohol related seizures, but may provide a useful contribution to the overall
diagnostic investigation of seizures. Confirmatory studies are needed as to the
apparent vulnerability of CDT to antiepileptic drugs.
PMID- 10675219
TI - Prevalence of multiple sclerosis in the L'Aquila district, central Italy.
AB - OBJECTIVE: To estimate the prevalence of multiple sclerosis in the L'Aquila
district, central Italy. METHODS: All available case sources were screened.
Definite and probable cases of multiple sclerosis, classified according to the
Poser criteria, were considered as prevalent cases. RESULTS: On the prevalence
day, 31 December 1996, 158 patients (105 women and 53 men; ratio 2:1) affected by
definite (n=131) or probable (n=27) multiple sclerosis were alive and resident in
the L'Aquila district. Mean (SD) age was 38.4 (11.9) years (38.9 (11.7) years for
women and 38.5 (12.3) years for men, p=0.9). The overall crude prevalence was
53.0/100 000 (95% confidence interval (95% CI)=45.4-62.0); 68.4/100 000 (95%
CI=56. 5-82.8) in women, and 36.7/100 000 (95% CI=28.1-48.0) in men. The
prevalence was similar (55.9/100 000) when standardised to the 1996 European
population. Mean (SD) age at onset of multiple sclerosis was 29.4 (9.6) years and
mean (SD) duration of the disease was 9.4 (7.4) years, without any significant
difference between sexes. Mean age at onset was significantly higher in patients
with the primary progressive than in those with the relapsing-remitting course
(p=0. 0002, Scheffe's test). CONCLUSIONS: The prevalence found in the L'Aquila
district gives support to the consideration of Italy as an area in which multiple
sclerosis has been shown to have high prevalence at least in the populations that
were surveyed recently.
PMID- 10675220
TI - Evaluation of (18)fluorodeoxyglucose positron emission tomography ((18)FDG PET)
in the detection of malignant peripheral nerve sheath tumours arising from within
plexiform neurofibromas in neurofibromatosis 1.
AB - OBJECTIVES: The ability of (18)fluorodeoxyglucose positron emission tomography
((18)FDG PET) to detect malignant change in plexiform neurofibromas from patients
with neurofibromatosis 1 (NF1) was evaluated. METHODS: Eighteen NF1 patients who
presented with pain, increase in size, or neurological deficit associated with a
plexiform neurofibroma were assessed. Magnetic resonance imaging determined the
site and extent of the lesion. Qualitative(18)FDG PET was performed and the
standard uptake value (SUV) measured the regional glucose metabolism.
Histological confirmation of the diagnosis was obtained in 10 patients. RESULTS:
Twenty three plexiform neurofibromas were detected in 18 patients. Seven
malignant peripheral nerve sheath tumours, four high grade and three low grade
tumours, occurred in five patients. In one patient the clinical and radiological
characteristics of the tumour suggested malignancy, but histology was
inconclusive. Fifteen benign plexiform neurofibromas were identified in 12
patients and these findings were confirmed histologically in five lesions from
four patients. Ten plexiform neurofibromas occurring in eight patients were
considered benign on(18)FDG PET and the patients did not undergo surgery. They
remained stable or their symptoms improved on clinical follow up (median 9
months). The results of qualitative (18)FDG PET were interpreted as indicating
that 13 plexiform neurofibromas were benign and 10 were malignant. No malignant
tumours were classified as benign, but two benign tumours were reported as
malignant. The SUV was calculated for 20 tumours and was significantly higher in
five malignant tumours 5.4 (SD 2.4), than in 15 benign tumours 1.54 (SD 0.7),
p=0.002. There was an overlap between benign and malignant tumours in the SUV
range 2.7-3.3. CONCLUSIONS: (18)FDG PET is helpful in determining malignant
change in plexiform neurofibromas in NF1. Increased separation between benign and
malignant lesions could be obtained by calculating the SUV at about 200 minutes
after injection of (18)FDG, when the peak activity concentration is obtained in
malignant tumours.
PMID- 10675221
TI - Fear conditioned potentiation of the acoustic blink reflex in patients with
cerebellar lesions.
AB - OBJECTIVE: To investigate whether the human cerebellum takes part in fear
conditioned potentiation of the acoustic blink reflex. METHODS: A group of 10
cerebellar patients (eight patients with lesions involving the medial cerebellum,
two patients with circumscribed lesions of the cerebellar hemispheres) was
compared with a group of 16 age and sex matched healthy control subjects. The
fear conditioned potentiation paradigm consisted of three phases. During the
first, habituation phase subjects received 20 successive acoustic blink stimuli.
In the subsequent fear conditioning phase, subjects passed through 20 paired
presentations of the unconditioned fear stimulus (US; an electric shock) and the
conditioned stimulus (CS; a light). Thereafter, subjects underwent the
potentiation phase, which consisted of a pseudorandom order of 12 trials of the
acoustic blink stimulus alone, 12 acoustic blink stimuli paired with the
conditioned stimulus, and six conditioned stimuli paired with the unconditioned
stimulus. The EMG of the acoustic blink reflex was recorded at the orbicularis
oculi muscles. The potentiation effect was determined as the difference in
normalised peak amplitude of the blink reflex evoked by pairs of CS and acoustic
blink stimuli and evoked by the acoustic stimulus alone. RESULTS: In the
habituation phase, short term habituation of the acoustic blink reflex was
preserved in all cerebellar patients. However, in the potentiation phase, the
potentiation effect of the blink reflex was significantly reduced in patients
with medial cerebellar lesions compared with the controls (mean (SD) potentiation
effect (%), patients: -6.4 (15.3), controls: 21.6 (35.6)), but was within normal
limits in the two patients with lateral lesions. CONCLUSIONS: The present
findings suggest that the human medial cerebellum is involved in associative
learning of non-specific aversive reactions-that is, the fear conditioned
potentiation of the acoustic blink reflex.
PMID- 10675222
TI - The London handicap scale: a re-evaluation of its validity using standard scoring
and simple summation.
AB - OBJECTIVE: To assess the validity of the London handicap scale (LHS) using a
simple unweighted scoring system compared with traditional weighted scoring
METHODS: 323 patients admitted to hospital with acute stroke were followed up by
interview 6 months after their stroke as part of a trial looking at the impact of
a family support organiser. Outcome measures included the six item LHS, the
Dartmouth COOP charts, the Frenchay activities index, the Barthel index, and the
hospital anxiety and depression scale. Patients' handicap score was calculated
both using the standard procedure (with weighting) for the LHS, and using a
simple summation procedure without weighting (U-LHS). Construct validity of both
LHS and U-LHS was assessed by testing their correlations with the other outcome
measures. RESULTS: Cronbach's alpha for the LHS was 0.83. The U-LHS was highly
correlated with the LHS (r=0.98). Correlation of U-LHS with the other outcome
measures gave very similar results to correlation of LHS with these measures.
CONCLUSION: Simple summation scoring of the LHS does not lead to any change in
the measurement properties of the instrument compared with standard weighted
scoring. Unweighted scores are easier to calculate and interpret, so it is
recommended that these are used.
PMID- 10675223
TI - Upregulation of matrix metalloproteinase-9 in the cerebrospinal fluid of patients
with acute Lyme neuroborreliosis.
AB - It was investigated (1) whether metalloproteinase-9 (MMP-9), MMP-3, and tissue
inhibitor of matrix metalloproteinase-1 (TIMP-1, the natural tissue inhibitor of
MMP-9) are increased in the CSF of patients with Lyme neuroborreliosis and (2)
whether macrophages can express MMP-9 when stimulated with Borrelia burgdorferi.
Zymography showed MMP-9 activity in 26 of 31 (84%) CSF samples from patients with
acute stage 2 Lyme neuroborreliosis, but not in 20 controls with non-inflammatory
neurological disorders. Activity of MMP-2 was detected in all CSF samples in both
patients with neuroborreliosis and controls, suggesting a constitutive release of
MMP-2. Using enzyme linked immunosorbent assay (ELISA) MMP-3 (which can activate
MMP-9) was detected in low concentrations in the CSF of 13 of 29 patients with
neuroborreliosis, but not in controls. TIMP-1 was increased twofold in CSF
samples from patients with neuroborreliosis in comparison with the controls. MMP
9 activity was induced in vitro in a mouse macrophage cell line (RAW 264.7) when
stimulated with two different genospecies of B burgdorferi (B garinii, B afzelii
). This MMP-9 activity was reduced in a dose dependent manner when macrophages
stimulated with B burgdorferi were coincubated with NF-kappaB SN50, a cell
permeable peptide which inhibits the translocation of NF-kappaB into the nucleus
of stimulated cells. The data show that (1) MMP-9 activity is present in the CSF
of patients with neuroborreliosis, (2) macrophages stimulated with B burgdorferi
are a possible source of MMP-9 increase, and (3) activation of NF-kappaB may play
a part in the upregulation of MMP-9 by B burgdorferi.
PMID- 10675224
TI - Histological subtypes of symptomatic central nervous system tumours in Singapore.
AB - The objective was to identify the different subtypes of symptomatic CNS tumours
that are encountered in Singapore. Our hospital pathology and operative records
from 1994 to 1998 were reviewed and information regarding all patients who
underwent biopsy or resection as part of their diagnostic and therapeutic
evaluation was extracted. Only histologically confirmed tumours were included in
this analysis. Meningiomas made up the largest subgroup of tumours, accounting
for 35.1% of all tumours. In order of decreasing frequency, the remaining most
often reported histologies were pituitary adenomas (11.8%), secondary neoplasms
(10%), tumours of nerve sheath (9.4%), glioblastoma multiforme (9.3%),
astrocytomas including anaplastic, diffuse and pilocytic (9.2%), primary CNS
lymphomas (2.9%), oligodendrogliomas (2.2%), hemangioblastomas (2. 2%),
craniopharyngiomas (1.7%), and embryonal tumours (1.2%). Genetic and
environmental factors may be responsible for the proportionately higher than
expected percentage of meningiomas seen and further study is required to identify
these factors.
PMID- 10675225
TI - New variant Creutzfeldt-Jakob disease: three case reports from Leicestershire.
AB - Since a report in 1996 of 10 cases of Creutzfeldt-Jakob disease (CJD) with onset
in a younger than usual age, a pattern of the disease has emerged. This includes
early neuropsychiatric features and sensory symptoms and neurological signs such
as ataxia and involuntary movements later in the course of the disease. Three
patients with varied clinical presentations and disease course seen at a single
neurology unit are described. The first patient was characterised by cognitive
and psychiatric symptoms together with neurological signs. The second patient
presented with unusual behavioural disturbance and episodes of collapse. The
third patient exhibited striking psychomotor retardation and had abnormal CSF and
MRI findings. All patients succumbed in a state of akinetic mutism and myoclonus.
All three patients had the methionine/methionine genotype at codon 129 of the PrP
gene and in two of the three patients a tonsil biopsy was performed with positive
results. These two patients also tested positive for the 14.3.3. protein in the
CSF. Whereas late features of the disease seem very similar in all cases, the
initial presentation was variable and underlines the uncertainty of the range of
the clinical phenotype. Successful diagnosis demands a high index of clinical
suspicion.
PMID- 10675226
TI - Idiopathic intracranial hypertension and anticardiolipin antibodies.
AB - The association of idiopathic intracranial hypertension (IIH) or pseudotumour
cerebri (PTC) with anticardiolipin antibodies (aCL-Abs) has been only
acknowledged recently. However, its true incidence is as yet unknown. In this
retrospective study, the co-occurrence of IIH and aCL-Abs was looked for among a
relatively large group of patients diagnosed with IIH or PTC in the neuro
ophthalmology clinic during the years of 1992-8. All patients underwent routine
blood tests and the presence of activated protein C resistance and protein S and
protein C deficiency were recorded. ACL-Abs were determined in all patients. The
co-occurrence of IIH and aCL-Abs was found in three out of 37 patients (8.1%),
which is higher than the incidence of aCL-Abs in the general population but
considerably lower than that reported in two previously published studies. The
aCL-Ab positive patients in our series were significantly older and thinner than
those in whom antibodies were undetected. In conclusion, it seems that patients
with this association should be considered as a unique subgroup of IIH.
PMID- 10675227
TI - Improvement of memory guided saccades in parkinsonian patients by high frequency
subthalamic nucleus stimulation.
AB - Recent studies in the monkey suggest that the subthalamic nucleus (STN) is
involved in control of eye movement, yet its functional significance in humans is
unknown. Saccadic eye movements were studied in eight parkinsonian patients
treated by bilateral electrical stimulation of the STN. STN stimulation improved
the accuracy of memory guided saccades but not of reflexive visually guided
saccades and had no effect on the antisaccade task. This study shows that, by
contrast with levodopa, STN stimulation improves memory guided saccade deficits,
and illustrates for the first time in humans the role of the STN in the control
of purposive saccades.
PMID- 10675228
TI - Neurological truant.
PMID- 10675229
TI - Myopathy due to primary systemic amyloidosis.
PMID- 10675231
TI - Intra-operative diagnosis of CNS tumours
PMID- 10675230
TI - Monocular visual loss and platelet fibrin embolism to the retina.
PMID- 10675232
TI - MRI of the brain. Normal anatomy and normal variants
PMID- 10675234
TI - Clinical diagnosis and management of Alzheimer's disease, 2nd edition
PMID- 10675233
TI - Everything you need to know about old age psychiatry
PMID- 10675235
TI - Dementia handbook
PMID- 10675237
TI - Effect of laparoscopic fundoplication on gastroesophageal reflux disease-induced
respiratory symptoms.
AB - Laparoscopic fundoplication controls heartburn and regurgitation, but the effects
on the respiratory symptoms of gastroesophageal reflux disease (GERD) are
unclear. Confusion stems from difficulty preoperatively in determining whether
cough or wheezing is actually caused by reflux when reflux is found on pH
monitoring. To date, there is no proven way to pinpoint a cause-and-effect
relationship. The goals of this study were to assess the following: (1) the value
of pH monitoring in establishing a correlation between respiratory symptoms and
reflux; (2) the predictive value of pH monitoring on the results of surgical
treatment; and (3) the outcome of laparoscopic fundoplication on GERD-induced
respiratory symptoms. Between October 1992 and October 1998, a total of 340
patients underwent laparoscopic fundoplication for GERD. From the clinical
findings alone, respiratory symptoms were thought possibly to be caused by GERD
in 39 patients (11%). These 39 patients had been symptomatic for an average of
134 months. They were all taking H2-blocking agents (21%) or proton pump
inhibitors (79%). Seven patients (18%) were also being treated with
bronchodilators, alone (3 patients) or in combination with prednisone (4
patients). Median length of postoperative follow-up was 28 months. In 23 patients
(59%) a temporal correlation was found during 24-hour pH monitoring between
respiratory symptoms and episodes of reflux. Postoperatively heartburn resolved
in 91% of patients, regurgitation in 90% of patients, wheezing in 64% of
patients, and cough in 74% of patients. Cough resolved in 19 (83%) of 23 patients
in whom a correlation between cough and reflux was found during pH monitoring,
but in only 8 (57%) of 14 of patients when this correlation was absent. Cough
persisted postoperatively in the two patients who did not cough during the study.
These data show that pH monitoring helped to establish a correlation between
respiratory symptoms and reflux, and it helped to identify the patients most
likely to benefit from antireflux surgery. Following laparoscopic surgery,
respiratory symptoms resolved in 83% of patients when a temporal correlation
between cough and reflux was found on pH monitoring; heartburn and regurgitation
resolved in 90%.
PMID- 10675236
TI - Telomerase reverse transcriptase expression is increased early in the Barrett's
metaplasia, dysplasia, adenocarcinoma sequence.
AB - Barrett's esophagus is a multistage polyclonal disease that is associated with
the development of adenocarcinoma of the esophagus and esophagogastric junction.
Telomerase activation is associated with cellular immortality and carcinogenesis,
and increased expression of the telomerase reverse transcriptase catalytic
subunit (hTERT) has been used for the early detection of malignant diseases. To
identify biomarkers associated with each stage of the Barrett's process, relative
mRNA expression levels of hTERT were measured using a quantitative reverse
transcription-polymerase chain reaction method (ABI 7700 Sequence Detector
(TaqMan system) in Barrett's intestinal metaplasia (n = 14), Barrett's dysplasia
(n = 10), Barrett's adenocarcinoma (n = 14), and matching normal squamous
esophagus tissues (n = 32). hTERT expression was significantly increased at all
stages of Barrett's esophagus, including the intestinal metaplasia stage,
compared to normal tissues from patients without cancer (intestinal metaplasia
vs. normal esophagus, P <0.0001; dysplasia, P = 0.001; adenocarcinoma, P = 0.007;
all Mann-Whitney U test ). hTERT expression levels were significantly higher in
adenocarcinoma tissues than in intestinal metaplasia tissues (P = 0.003), and
were higher in dysplasia compared with intestinal metaplasia tissues (P = 0.056).
hTERT levels were also significantly higher in histologically normal squamous
esophagus tissues from cancer patients than in normal esophagus tissues from
patients with no cancer (P = 0.013). Very high expression levels ([hTERT x 100:
beta-actin] >20) were found only in patients with cancer. These findings suggest
that telomerase activation is an important early event in the development of
Barrett's esophagus and esophageal adenocarcinoma, that very high telomerase
levels may be a clinically useful biomarker for the detection of occult
adenocarcinoma, and that a widespread cancer "field" effect is present in the
esophagus of patients with Barrett's cancer.
PMID- 10675238
TI - Nonsteroidal anti-inflammatory drugs attenuate proliferation of colonic carcinoma
cells by blocking epidermal growth factor-induced Ca++ mobilization.
AB - Numerous studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs)
inhibit colorectal carcinogenesis. We have previously reported that NSAIDs, in
human colonic carcinoma cells (Caco-2), attenuate epidermal growth factor (EGF)
induced cellular proliferation through a process independent of their inhibitory
effects on prostaglandin synthesis. Furthermore, separate studies have also
suggested that NSAIDs inhibit EGF-induced store-operated Ca++ influx. Thus we
developed the hypothesis that NSAIDs may limit the activity of EGF by altering
intracellular Ca++ ([Ca++]i) mobilization. Serum-deprived Caco-2 cells were
employed for all experimentation. [Ca++]i was measured with Fluo-3 and
extracellular Ca++ influx was monitored by quenching Fluo-3 fluorescence with
Mn++. Proliferation was quantitated with two assays: cellular nucleic acid and
total protein content. Caco-2 cells exposed to EGF demonstrated an initial
increase in [Ca++]i which was blocked by neomycin, an inhibitor of IPsubscript 3
generation, and the phospholipase C inhibitor U73122 but not U73343 (inactive
control). This was followed by sustained extracellular Ca++ influx, which was
attenuated with calcium-free buffer (-Ca++), the store- operated Ca++ channel
blocker lanthanum, indomethacin, ibuprofen, and aspirin. In subsequent studies,
cells were treated with either serum-free media or EGF +/- the aforementioned
inhibitors, and again serum starved. Cells exposed to EGF +/- the inactive
phospholipase C inhibitor U73343 demonstrated a significant increase in nucleic
acid and protein. However, proliferation induced by EGF was not observed when
[Ca++]i elevation was prevented by blocking either internal Ca++ store release
via phospholipase C/IPsubscript 3 or sustained Ca++ influx through store-operated
Ca++ channels. Sustained [Ca++]i elevation, as induced by EGF, appears to be
required for mitogenesis. These data support our premise that one mechanism
whereby NSAIDs may attenuate colonic neoplasia is by blocking EGF-induced Ca++
mobilization.
PMID- 10675239
TI - Hepatic resection using intermittent vascular inflow occlusion and low central
venous pressure anesthesia improves morbidity and mortality.
AB - Hepatic resection results in significant morbidity and mortality primarily
related to intraoperative blood loss. Intermittent vascular inflow occlusion (VO)
and low central venous pressure (CVP) during hepatectomy have been used to reduce
blood loss. To determine the benefit of VO and low CVP, we reviewed the outcomes
of 168 consecutive patients who underwent liver resection. The results of 78
patients who had undergone hepatic resection between 1993 and 1998 with the use
of VO and low CVP (post-VO/CVP) were compared to the previous 90 patients who had
undergone hepatectomy without VO and low CVP (pre-VO/CVP) between 1979 and 1992.
Hepatectomies were performed for metastatic disease (65%), hepatoma (20%), and
benign tumors (15%). Resections included 18 trisegmentectomies, 67 lobectomies,
and 83 segmental resections. Patients in both groups were similar with regard to
extent of resection. Post-VO/CVP patients had significantly lower median
estimated blood loss (725 ml vs. 2300 ml, P <0.001), less postoperative morbidity
(10.3% vs. 22. 2%, P = 0.038), lower in-hospital mortality (2.6% vs. 10%, P = 0.
050), fewer days in the intensive care unit (1.6 +/- 0.1 days vs. 5. 6 +/- 1.2
days, P = 0.003), and shorter overall length of stay (8.0 +/- 0.5 days vs. 15.0
+/- 1.6 days, P <0.001) than pre-VO/CVP patients. These data suggest that VO and
low CVP during liver resection may improve patient outcomes.
PMID- 10675240
TI - Isolated right segmental hepatic duct injury: a diagnostic and therapeutic
challenge.
AB - Biliary leaks and injuries are not an uncommon occurrence following laparoscopic
cholecystectomy. Bile leaks associated with the biliary anatomic variant of a low
inserting right segmental hepatic duct can be particularly difficult to diagnose
in that results of endoscopic retrograde cholangiography (ERC) are usually
interpreted as "normal" with no leaks demonstrated. The aim of this study was to
describe a single institution's experience with nine patients with biliary leaks
associated with this anatomic variant and to discuss their management. A
retrospective analysis of the hospital records of all patients with bile duct
injuries managed at a single institution between 1980 and July 1998, inclusive,
was performed. Nine patients were identified as having an isolated right
segmental hepatic duct injury associated with a biliary leak. Seven (78%) of the
nine patients had undergone a laparoscopic cholecystectomy, whereas the remaining
two patients (22%) had undergone an open cholecystectomy. All of the patients had
undergone endoscopic retrograde cholangiography at outside institutions, the
results of which had been interpreted as normal with no apparent leaks. The
median interval from the time of cholecystectomy to referral was 1.4 months. All
patients were managed with initial percutaneous access of the involved right
segmental biliary system, with placement of a percutaneous transhepatic stent.
After the biliary leak was controlled, all patients underwent Roux-en-Y
hepaticojejunostomy to the isolated biliary segment. All patients had an
uncomplicated postoperative course. There were no postoperative anastomotic
leaks. Postoperative stenting was maintained for a mean of 8 months. Six (67%) of
the nine patients had a long-term successful outcome with minimal or no symptoms.
In three patients, recurrent symptoms with pain and/or cholangitis developed at a
mean of 34 months. All three patients underwent percutaneous cholangiography,
which demonstrated an anastomotic stricture, and all were managed with
percutaneous balloon dilatation with a successful outcome. Currently eight (89%)
of the nine patients are asymptomatic, with a mean follow-up of 70.4 months
(range 12 to 226 months). One patient had intermittent right upper quadrant pain
with normal liver function tests but has not required intervention. Isolated
right segmental hepatic ductal injury with biliary leakage is an uncommon
complication following laparoscopic cholecystectomy. A diagnostic dilemma is
created by the presence of a bile leak with a normal endoscopic retrograde
cholangiogram. Management begins with percutaneous access of the transected
isolated ductal system followed by reconstruction as a Roux-en-Y
hepaticojejunostomy.
PMID- 10675241
TI - Anatomic segmental hepatic resection is superior to wedge resection as an
oncologic operation for colorectal liver metastases.
AB - Hepatic wedge resection for colorectal liver metastasis has been reported to have
a high incidence of positive surgical margins. Anatomic segmental resection is
now widely practiced, although there are few data comparing segmental and wedge
resection in terms of tumor clearance or long-term outcome. There were 267
patients who underwent liver resection for metastatic colorectal cancer between
July 1985 and October 1998 at our institution who had either a wedge (n = 119) or
segmental (n = 148) resection. Patient, tumor, and treatment data were compared,
actuarial survival was determined, and prognostic factors were analyzed. Anatomic
segmental resection was associated with similar blood loss, operative time, and
complications as wedge resection. Segmental resection had a significantly lower
rate of positive margins (2% vs. 16%) compared to wedge hepatectomy (P <0.001).
On univariate analysis, segmentectomy resulted in longer survival with a median
of 53 months vs. 38 months for wedge hepatectomy (P = 0.015). Preoperative
carcinoembryonic antigen level, positive margin of resection, and the presence of
extrahepatic disease independently predicted survival on multivariate analysis.
Anatomic segmental resection is a safe procedure and is superior to wedge
resection as an oncologic operation for colorectal liver metastasis because it
results in better tumor clearance and improved survival.
PMID- 10675242
TI - Inflammatory cytokines alter human gallbladder epithelial cell
absorption/secretion.
AB - Gallbladder inflammation is an early feature of gallstone formation in animal
models. The inflammatory response is associated with increases in myeloperoxidase
and interleukin (IL)-1 activities in the gallbladder wall. The present studies
were designed to determine whether inflammatory cytokines directly affect
gallbladder epithelial cell absorptive function. Studies were performed using
cultured human gallbladder epithelial cells derived from a well-differentiated
gallbladder carcinoma. Confluent monolayers were exposed to interleukin-1 (IL
1alpha), IL-1alpha plus its specific receptor inhibitor IL-1ra, tumor necrosis
factor (TNF-alpha), lipopolysaccharide, or prostaglandin E2. Unidirectional
sodium and chloride fluxes were measured and used to calculate net ion fluxes.
Compared to control monolayers, lipopolysaccharide, prostaglandin E2, IL-1alpha,
and TNF-alpha decreased mucosal-to-serosal and net sodium and chloride fluxes and
increased serosal-to-mucosal movement of sodium and unmeasured ions. The effects
of IL-1alpha were completely inhibited by its specific receptor antagonist IL
1ra. Similar to the proinflammatory agents lipopolysaccharide and prostaglandin
E2, the inflammatory cytokines IL-1alpha and TNF-alpha directly affected
gallbladder epithelial cell absorptive function. Because normal gallbladder
absorptive function is protective against gallstone formation, alterations in
absorptive function due to inflammation in the gallbladder wall may play a role
in gallstone pathogenesis.
PMID- 10675243
TI - Role of cytosolic phospholipase A2 in cytokine-stimulated prostaglandin release
by human gallbladder cells.
AB - Eicosanoids are involved in gallbladder inflammation, epithelial water transport,
and mucous secretion. Phospholipase Asubscript2 enzymes liberate arachidonic acid
from membrane phospholipids for the synthesis of eicosanoids. The purpose of this
study was to determine the effect of selective cytoplasmic and secretory
phospholipase A2 inhibitors on basal and stimulated arachidonic acid and
prostaglandin E2 release in gallbladder cells. Western immunoblotting was
employed to evaluate both cytosolic and secretory phospholipase A2 enzymes in
human gallbladder cells. Cells were incubated for 22 hours with (3)H-labeled
arachidonic acid. Arachidonic acid and prostaglandin E2 release was then measured
in the supernate after 2 hours of exposure to human interleukin-1beta, alone or
after pretreatment for 1 hour with the inhibitors. Unstimulated gallbladder cells
express both 85 kDa cytosolic and 14 kDa secretory phospholipase A2++. The 85 kDa
phospholipase A2 was induced by interleukin-1beta, whereas there was no apparent
change in secretory phospholipase A2 enzyme concentrations. Both the secretory
phospholipase A2 inhibitor p-bromophenylacyl bromide and the cytosolic
phospholipase A2 inhibitor arachidonyl trifluoromethyl ketone decreased basal and
interleukin-1beta-stimulated arachidonic acid release. In contrast, only
inhibition of cytosolic phospholipase A2 led to a decrease in interleukin-1beta
stimulated prostaglandin E2 release. Basal and interleukin-1beta-stimulated
arachidonic acid release appears to be the result of the activity of both
cytosolic and secretory phospholipase A2. Interleukin-1beta-stimulated
prostaglandin E2 release appears to be dependent on the activity of cytosolic
phospholipase A2.
PMID- 10675244
TI - Predicting the need for colectomy in pediatric patients with ulcerative colitis.
AB - Total colectomy is curative for ulcerative colitis. However, many pediatric
patients are medically managed and may not require surgery. There are currently
no available criteria to identify children who will benefit from early colectomy.
The purpose of this review was to identify criteria associated with the need for
colectomy. A 15-year review of patients at a major pediatric center with biopsy
proved ulcerative colitis was conducted. Age at the time of the first symptom,
diagnosis, and surgery were recorded as well as steroid dependence, site of
disease, extraintestinal manifestations, and family history. Seventy-three
patients ranging in age from 1 to 18 years were identified. Thirty-seven patients
(50.1%) required total colectomy before the age of 18. The average patient age at
the time of the first documented symptom was 11.3 +/- 0.5 years. Among patients
who were steroid dependent and had pancolitis, 73% required colectomy. Patients
with these factors failed medical management 77% (27 of 35) of the time, and
colectomy was performed within 3 years of diagnosis. The combination of steroid
dependence and pancolitis was associated with an increased need for colectomy. In
pediatric patients with these factors, early colectomy may limit the need to
endure prolonged courses of medications and the disability allied with this
disease.
PMID- 10675245
TI - The jejunal pouch as a rectal substitute after proctocolectomy.
AB - Our hypothesis was that a jejunal pouch used as a rectal substitute after
proctocolectomy would slow enteric transit, delay defecation, and decrease stool
frequency compared to an ileal pouch so used. Twelve dogs underwent
proctocolectomy; six had a jejunal pouch-distal rectal anastomosis and six had an
ileal pouch-distal rectal anastomosis. After recovery, postprandial mouth-to-anus
transit was slower in jejunal pouch dogs (253 +/- 18 minutes [mean +/- SEM]) than
in ileal pouch dogs (112 +/- 7.9 minutes; P <0.05). Moreover, jejunal pouch dogs
passed only 4.1 +/- 0.3 stools during the 12 hours after eating, whereas ileal
pouch dogs passed 6.3 +/- 0. 9 stools (P <0.05). The mean frequency of proximal
ileal pacesetter potentials after feeding was less in jejunal pouch dogs (12 +/-
0.4 cycles/min) than in ileal pouch dogs (16 +/- 0.3 counts/min; P = 0. 01), and
jejunal pouches had more action potentials (jejunal = 82% +/- 4.3% of pacesetter
potentials had action potentials, ileal = 61% +/- 3.0%; P <0.05). In contrast,
gastric emptying and pouch motility, emptying, mucosal integrity, and
bacteriologic and histologic properties were similar in the two groups of dogs.
We concluded that the jejunal pouch operation slowed enteric transit, delayed
defecation, and decreased postprandial stooling compared to the ileal pouch
operation.
PMID- 10675247
TI - Economic models of animal communication.
AB - Many models of animal signal evolution fail to incorporate an explicit strategy
for receivers prior to the evolution of signals. When reasonable assumptions are
made for such strategies, we have shown that there is a minimal accuracy of
signal coding that is required before receivers should attend to signals
(Bradbury & Vehrencamp 1998, Principles of Animal Communication). Depending upon
the relative payoffs of correct and incorrect decisions by receivers, this
minimal accuracy can be quite high. Here we use this result to explain why so
many signals appear to be traits that provided useful information to receivers
before becoming ritualized into signals. Our model also supports one prediction
of sensory drive models: that latent preferences may selectively favour some
signal precursors over others. However, it imposes a serious constraint on
sensory drive by requiring that there be sufficient benefits to a receiver to
compensate for the costs of disrupting the optimal receiver strategy used before
exploitation. Finally, we discuss the overlap between signal honesty and accuracy
and show how senders that completely disagree with receivers about appropriate
receiver decisions may still benefit by providing moderately honest and accurate
signals. Copyright 2000 The Association for the Study of Animal Behaviour.
PMID- 10675246
TI - Prospective randomized trial of early initiation and hospital discharge on a
liquid diet following elective intestinal surgery.
AB - Length of hospital stay after elective intestinal surgery may be related to
patient tolerance of a diet. We hypothesized that early initiation and discharge
home on a clear liquid diet would decrease the length of hospital stay without
increasing morbidity. The aim of this study was to determine if early initiation
and discharge on a clear liquid diet decreases the length of hospital stay and is
safe. Forty-four patients were randomly assigned to either a standard diet or a
clear liquid diet. A standard diet (n = 17) was begun after the passage of flatus
or stool, and consisted of clear liquids to a volume of approximately 750 ml,
then three solid meals, and discharge thereafter. Patients randomized to a clear
liquid diet (n = 27) received 30 ml/hr of clear liquids on postoperative day 2,
unlimited clear liquids on postoperative day 3, and were dismissed on a clear
liquid diet on postoperative day 4. All patients were followed by a daily
telephone call and clinic visit. The primary outcome variable was length of
hospital stay. The incidence of postoperative intestinal-related sequelae,
complications, and readmission rates did not differ between groups. Postdischarge
intestinal symptoms were common in both groups but tended to resolve faster in
the patients on a standard diet. The length of hospital stay was decreased in the
patients on a clear liquid diet compared to those on a standard diet (6.1 +/- 1.1
days vs. 4.4 +/- 0.2 days; P = 0.09), but total hospital costs did not differ.
Early initiation and hospital discharge on a clear liquid diet after elective
intestinal surgery decreases the length of hospital stay and is safe.
PMID- 10675248
TI - Assessing the degree of association in groups of animals using the concept of
entropy.
AB - Nearest-neighbour analysis is commonly used to calculate indices of aggregation
in groups of animals. It has several problems, however, including lack of data
independence and, when studying groups of animals penned at high densities, the
difficulty of determining a given individual's nearest neighbour. We describe an
entropy-based method to assess the degree of association (or segregation) of
groups of animals. We show that this method gives more information and is more
sensitive than the nearest-neighbour technique. An example with a particular
experimental situation (mixing groups of lambs) is presented. Copyright 2000 The
Association for the Study of Animal Behaviour.
PMID- 10675249
TI - Females of the lekking great snipe do not prefer males with whiter tails.
AB - A previous experimental study of great snipe, Gallinago media, has reported an
effect on male mating success of the amount of white in their tails. That result
is one of a very limited set of existing experimental results supporting a female
mate preference for a morphological trait in animals. However, a later
observational study did not find any correlation between amount of white and male
mating success. If females sample a limited number of males, their preferences
need not result in strong relationships between mating success and trait values
in males, possibly explaining the failure to find the predicted correlation. Yet,
females of lekking species are thought to have ample opportunities for mate
sampling. To resolve these contrasting results, we present in this paper (1) a
larger correlational study (several leks during 10 years) showing no relationship
between male mating success and whiteness of tails (measured in several ways),
and most importantly (2) evidence that individual females do not mate
predominantly with males with very white tails among those males that each female
samples. These results show that females do not prefer males with whiter tails as
mates, within the contemporary natural variation in the trait. They also show
that there is no sexual selection of the trait at present. This does not
necessarily imply that white tails are not a sexually selected adaptation in
males, but the mechanisms are likely to have been different from direct mate
choice of whiter tails per se. Copyright 2000 The Association for the Study of
Animal Behaviour.
PMID- 10675250
TI - Did aggregation favour the initial evolution of warning coloration? A novel world
revisited.
AB - From experiments using novel prey signals to avoid innate reactions to
traditional signals, Alatalo & Mappes (1996, Nature, 382, 708-710) concluded that
gregariousness would have selected for warning coloration as it originated for
the first time, whereas a solitary prey distribution would not. We have
investigated this suggestion in experiments using the same novel prey and
background symbols and wild-caught great tit, Parus major, predators. We compared
the attack rate on cryptic unpalatable and aposematic unpalatable prey in either
a solitary or an aggregated treatment. In the aggregated treatment we found no
difference in attack rate on cryptic and aposematic prey. In the solitary
treatment the attack rate on aposematic prey was significantly lower after one
attack and at the end of the experiment. Thus, we conclude that, in so far as
these experiments mimic an original predator-prey relationship, they do not give
support to the idea that aggregation would have favoured the evolution of warning
coloration in unpalatable prey. Copyright 2000 The Association for the Study of
Animal Behaviour.
PMID- 10675251
TI - Adoption of chicks and the level of relatedness in common gull, Larus canus,
colonies: DNA fingerprinting analyses.
AB - In common gull colonies on islands of the Vistula River, Poland, adoption of
chicks is common. In 1997, we observed 81 chicks from 35 nests. Of these, 19
(23.4%) left their natal broods and were adopted by other pairs. Another 11
(31.4%) were driven from the foreign territory by the owners. Foreign chicks were
adopted by 15 pairs (42.9%). Eleven pairs (31.4%) drove foreign chicks from the
territory. To test if the frequent adoptions in these colonies could be explained
by kin selection or the occurrence of kin groups, we calculated band-sharing
coefficients and genetic relatedness (r) between interacting birds (neighbours
and non-neighbours). Adults that adopted were most often neighbours of the
biological parents of adopted chicks, whereas spatially segregated birds, nesting
further away, usually drove off the chicks. Band-sharing coefficients between
males, but not females, were higher with decreasing internest distances. The band
sharing coefficients for adopted chicks and foster parents were significantly
higher than for adopted chicks and randomly selected, spatially segregated pairs
from the same and another colony. Band-sharing coefficients of adopted chicks and
adopting neighbours (males: r=0.20; females: r=0.16) also tended to be higher
than those of rejected chicks and rejecting neighbours (both sexes: r=0.08). Our
results suggest that kin groups of neighbours do occur in common gull colonies.
Such social structure might lead to indirect inclusive fitness benefits of
adopting pairs. Differences in genetic similarity between chicks and adopting or
rejecting neighbours show that at least in common gulls we should consider kin
altruism as a factor in adoptions. Copyright 2000 The Association for the Study
of Animal Behaviour.
PMID- 10675252
TI - Green plants in starling nests: effects on nestlings.
AB - European starlings, Sturnus vulgaris, intermingle fresh herbs, especially species
rich in volatile compounds, with their otherwise dry nest material. In this field
study we investigated whether these herbs reduce ectoparasites and thereby
protect nestlings (the nest protection hypothesis). We also considered whether
volatile compounds in herbs improve the condition of nestlings (the drug
hypothesis). As measures of condition we used body mass, haematocrit levels and
immunological parameters. We replaced 148 natural starling nests with artificial
ones: half contained herbs and half (controls) contained grass. The ectoparasite
loads (mites, lice, fleas) in herb and control nests were indistinguishable.
However, nestlings in herb nests weighed more and had higher haematocrit levels
at fledging than nestlings in control nests. Fledging success was similar in herb
and control nests, but more yearlings from herb nests were identified in the
colony the year after hatching. The response of the immune system when challenged
with phytohaemagglutinin did not differ in nestlings from herb and control nests.
Nestlings from herb nests had more basophils and fewer lymphocytes in their blood
than those from control nests, while the eosinophil and heterophil counts did not
differ. We conclude that herbs do not reduce the number of ectoparasites, but
they improve the condition of nestlings, perhaps by stimulating elements of the
immune system that help them to cope better with the harmful activities of
ectoparasites. Copyright 2000 The Association for the Study of Animal Behaviour.
PMID- 10675253
TI - Female-mediated differential sperm storage in a fly with complex spermathecae,
Scatophaga stercoraria.
AB - Multiple spermathecae potentially allow selective sperm use, provided that sperm
from rival males are stored differentially, that is, in different proportions
across storage compartments. In the yellow dung fly, Scatophaga stercoraria,
females have three spermathecae arranged as a doublet and singlet. To test
whether females store the sperm of rival males actively and differentially, we
mated fixed male pairs to three females. After copulation, females were (1)
dissected immediately before they could start laying a clutch of eggs, (2) left
awake for 30 min but prevented from oviposition, or (3) anaesthetized with carbon
dioxide for 30 min to interfere with the muscular control presumably required for
sperm transport from the site of insemination to the spermathecae. For each
female, we estimated the proportion of the second male's sperm stored in her
spermathecae (S(2)value), using sperm length as a male marker. After copulation,
the S(2)values in the singlet and doublet spermathecae differed significantly,
indicating differential sperm storage during copulation. Postcopulatory treatment
affected differential sperm storage significantly. Females dissected immediately
had lower S(2)values in the doublet than in the singlet spermatheca, while
females left awake showed the reverse pattern for the same two males. This
reversal did not occur when females were treated with carbon dioxide. The results
indicate differential storage of sperm from different males during copulation and
that female muscular activity can affect storage and separation of competing
ejaculates beyond copulation. Copyright 2000 The Association for the Study of
Animal Behaviour.
PMID- 10675254
TI - Sperm trading in a hermaphroditic flatworm: reluctant fathers and sexy mothers.
AB - When matings are frequent and received sperm are digested, hermaphrodites should
trade sperm when mating. We investigated sperm trading in the flatworm Schmidtea
(Dugesia) polychroa and manipulated mating interests to investigate its possible
causes. In 106 mating pairs consisting of nonisolated individuals, no sperm
donation in either direction (35%) and reciprocal exchange (38%) were more common
than expected by chance, whereas unilateral transfer (27%) was less frequent,
confirming sperm trading. The amount of sperm donated depended on the
availability of self-sperm, not on the amount received. Animals with more
allosperm from previous matings had more self-sperm and consequently donated
more. This suggests that sperm digestion boosts sperm production. In a second
experiment, 'mixed-interest' pairs consisting of a nonisolated (N) and an
isolated individual (I), NxI, were compared with IxI and NxN pairs. Whereas IxI
pairs were eager and NxN reluctant to mate, NxI pairs showed an intermediate
likelihood of mating. Whereas NxN pairs traded sperm, the other two groups did
not. The change in behaviour in N individuals in the NxI treatment suggests
precopulatory assessment and mating in relation to phenotypic mate quality.
Isolated individuals are attractive, presumably because they donate large sperm
clumps unconditionally and contain fewer allosperm, implying reduced sperm
competition. The reduced reluctance in N individuals to mate with, and to
inseminate, previously isolated partners suggests that female quality is an
important factor in male sperm donation decisions. Hence, S. polychroa may be
choosier than previously assumed. Copyright 2000 The Association for the Study of
Animal Behaviour.
PMID- 10675255
TI - Finescale topographical correlates of behavioural investment in offspring by
female grey seals, Halichoerus grypus.
AB - Grey seals breed colonially on substrates ranging from ice to rocky or sandy
beaches. Clear differences in seal behaviour patterns exist among such broad
classes of breeding habitat. However, finer scale topographical variation is
likely to influence individual behaviour with consequences for pupping success.
We examined topographical influences on the behaviour of breeding female grey
seals by quantifying topography at a subseal size resolution. Using submetre
resolution digital terrain models of two sites within a rocky breeding colony, we
compared site topography in relation to observed differences in female behaviour
at these sites. Females at both sites preferred breeding close to water (standing
pools or sea) and frequently commuted between their pups and water. Topographical
models indicated that one site was more costly for seals in terms of their
locations and movements within the site. This was due to a lack of low-elevation
land adjacent to the main access points from the sea and the reduced availability
of pools. Females at this site showed reduced pup attendance and an increase in
energetically costly behaviours, whilst females at the lower-cost site spent more
time interacting with their pups and resting. These topographically induced
behavioural differences are likely to affect the quantity and quality of pup
provisioning by mothers and influence individual pupping site selection. Less
costly sites are likely to be colonized preferentially and by larger, older and
more dominant females, potentially generating finescale spatial heterogeneity in
female quality within the breeding colony. Copyright 2000 The Association for the
Study of Animal Behaviour.
PMID- 10675256
TI - Components of lifetime mating success and body size in males of a scrambling
damselfly.
AB - Sexual selection is hypothesized to favour small body size in males of scrambling
species, that is, those in which males obtain matings by actively searching for
females. I tested this hypothesis in a natural population of the scrambling
emerald damselfly, Lestes sponsa. Mating efficiency (matings/visit to the pond)
was the most important factor explaining variation in male lifetime mating
success (LMS; 71%). This suggests a large potential for sexual selection. Path
analysis of male LMS suggested a quality factor that positively affected both
mating efficiency and life span. In contrast with the small-male mating advantage
hypothesis, part of this potential for sexual selection was realized as
stabilizing selection on male body size, indicating that there may also be a
lower limit to body size for mating efficiency. This also illustrates that the
constancy of body size may be explained by sexual selection alone. Survival
explained about 20% of the variation in LMS and random processes were potentially
important for determining LMS. My results show the problems of using mating
efficiency as a measure for the intensity of sexual selection and the need to
distinguish between potential and realized selection pressures, especially when
comparing the importance of natural and sexual selection. I discuss mechanisms
that may have caused the intermediate-male mating advantage in this scrambling
species. Copyright 2000 The Association for the Study of Animal Behaviour.
PMID- 10675257
TI - The transvestite serpent: why do male garter snakes court (some) other males?
AB - In large mating aggregations of red-sided garter snakes, Thamnophis sirtalis
parietalis, in Manitoba, male courtship is directed not only to females, but also
to other males with female-like skin lipids ('she-males'). We show that 'she
maleness' is an intrinsic property of a male rather than an artefact of lipid
transfer from females, and that male-male courtship is very common in the field.
She-males were distinctive in terms of appearance (they were heavier than other
males and more often covered with mud), behaviour (they were inactive and rarely
courted females) and performance (they were slow crawlers, ineffective courters
and easily outcompeted by other males in mating trials). 'She-maleness' was not a
characteristic of a particular subset of males, as envisaged in previous work;
instead, it was a transitory phase that most (perhaps all) male snakes passed
through soon after they first emerged from the winter den. Recently emerged males
spent their first day or two relatively inactive, while restoring physiological
functions (including locomotor performance and courtship ability). Experimental
application of female skin lipids on to males dramatically decreased courtship
levels of the recipient snakes. Thus, recently emerged males may derive two kinds
of benefit from mimicking female skin lipids. First, female mimicry 'switches
off' the male's own (energetically expensive) courtship at a time when that
courtship would be unproductive. Second, it may disadvantage his rivals by
distracting them from females, and increasing their energy expenditure. Copyright
2000 The Association for the Study of Animal Behaviour.
PMID- 10675258
TI - Acoustic satellite behaviour in the Australian bushcricket Elephantodeta nobilis
(Phaneropterinae, Tettigoniidae, Orthoptera).
AB - Male and female Elephantodeta nobilis duet with the female responding to the
male's long and complex call. The duetting male's call consisted of four parts,
described here as parts A, B, C and D. We found that the female replied 570 ms
after the male's D pulse, which followed the extended part B and short click of
part C. Noncalling males were attracted to the duet and often used satellite
tactics by inserting a volley of clicks 200 ms before the alpha male's D pulse.
Satellite males used part C of the alpha male song to cue their own call and this
inserted call induced females to reply earlier compared with the alpha male call
alone. Alpha males often extended their calls with additional D-type calls and so
we examined the effectiveness of these calls as countermeasures to satellite
calling. There was no influence of this alpha strategy on the satellite's
propensity to call although more calls from the alpha male did cause the female
to reply more frequently. We also examined the effect of relative intensity of
alpha and satellite calls on the female's reply. Reduced satellite intensity
increased the variance in the timing of the female response. Finally, we tested
the effectiveness of the satellite's call on female phonotaxis within a two
speaker arena. Although females preferred the alpha male they were nevertheless
attracted to the satellite calls regardless of the latter's relative intensity.
We discuss the possible role of satellite calling as a novel conditional
strategy. Copyright 2000 The Association for the Study of Animal Behaviour.
PMID- 10675259
TI - Free female mate choice in house mice affects reproductive success and offspring
viability and performance.
AB - We tested a critical assumption of sexual dialectics theory (Gowaty 1997,
Feminism and Evolutionary Biology, Chapman & Hall) using house mice, Mus
musculus. We asked if female house mice accrue viability benefits for their
offspring when they mate with males they prefer versus with males they do not
prefer. Our experiment was designed to eliminate or control other mechanisms of
reproductive competition besides female mate choice. After allowing females to
discriminate behaviourally between two males, which were at random with respect
to phenotypic variation discriminating females were paired with preferred (P) or
nonpreferred (NP) males. We then tested whether females mating with males they
preferred had offspring of higher viability than females mating with nonpreferred
males. In pairwise comparisons, we tested for differences in offspring
performance in dominance contests and in nest-building skill. At weaning, we
exposed half of the pups to cold stress. We tested progeny performance and
viability in the laboratory or in outdoor field enclosures. In comparison to P
females, NP females produced significantly fewer litters. Sons from P matings
were socially dominant to sons from NP matings. Adult offspring from P matings
built better nests than those from NP matings. In field enclosures significantly
fewer NP than P offspring survived to 60 days after introduction. Male and female
progeny from P matings established larger home ranges and constructed better
nests than progeny from NP matings. This is the first demonstration of progeny
viability differences for females allowed to express mate preferences between
males presented to them at random. Copyright 2000 The Association for the Study
of Animal Behaviour.
PMID- 10675260
TI - Egg-dumping lace bugs preferentially oviposit with kin.
AB - Egg dumping, or abandoning eggs and young to the care of other conspecifics,
results in an extreme form of alloparental care. It is unclear, however, if egg
dumpers discriminate among kin and nonkin egg recipients. In the lace bug
Gargaphia solani (Heteroptera: Tingidae), some females with eggs (guards) also
accept and defend eggs of conspecifics. Other females (egg dumpers) abandon their
offspring after oviposition, leaving a single guard as the caregiver. We asked if
egg dumpers preferentially dump their eggs among unguarded eggs of kin or nonkin.
When given a choice between dumping among eggs of full siblings and eggs of
nonsiblings, most eggs (67%) were dumped with full siblings' eggs. Furthermore,
egg dumpers were just as likely to oviposit among eggs of kin with whom they had
interacted on a shared host plant during juvenile development as they were to
oviposit with kin reared on different host plants. Thus, egg dumpers discriminate
kin by using cues associated with eggs, and such cues are not likely to be
acquired through interaction on a common host plant environment. Copyright 2000
The Association for the Study of Animal Behaviour.
PMID- 10675261
TI - Territory acquisition in loons: the importance of take-over.
AB - We examined patterns of territory acquisition and reconnaissance in common loons,
Gavia immer, from northern Wisconsin. Among all territory acquisitions, 41.5%
occurred through passive occupation of territories left vacant after the death or
desertion of a previous resident, 17% constituted founding of new territories and
the remaining 41.5% came about through take-over: either usurpation of defended
territories or appropriation of territories before the seasonal return of
previous owners. Take-overs occurred in both sexes, but individuals acted alone,
never in pairs. Displaced breeders usually took refuge on undefended lakes near
their former territories; about half of these loons later regained former
territories through passive occupation or took possession of new territories
elsewhere. As predicted by the reconnaissance hypothesis, usurpations occurred
most often in territories that had produced chicks during the previous 12 months,
suggesting that loons use the presence or absence of chicks as a cue for
territorial usurpation. Large individuals of both sexes held onto territories
longer than small individuals, an indication that body size might be correlated
with fighting ability. In terms of life history, loons appear to locate good
territories through reconnaissance, usurp them in a subsequent year and recover
from displacements by reclaiming their original territories or new ones.
Copyright 2000 The Association for the Study of Animal Behaviour.
PMID- 10675262
TI - Sperm storage by females of the polyandrous noctuid moth Heliothis virescens.
AB - Female tobacco budworm moths, Heliothis virescens, generally mate with more than
one male, receiving from each mate both fertilizing sperm (eupyrene) and
nonfertilizing anucleate sperm (apyrene), which is thought to play a role in
sperm competition. One male typically gains sperm precedence, but it is not
consistently the last or the first male to mate. I investigated the mechanism of
this variable pattern of paternity by examining the patterns of storage of both
types of sperm in the female's spermatheca as a function of multiple mating and
male phenotype. The number of stored apyrene sperm varied with mating history,
being greatest in twice-mated females and least in females mated to one nonvirgin
male. In contrast, only one ejaculate's worth of eupyrene sperm was stored
regardless of female mating history (once or twice mated). Thus, while they store
two complements of apyrene sperm, twice-mated females apparently store only one
ejaculate's worth of eupyrene sperm. This biased pattern of sperm storage may
contribute to the variable pattern of paternity observed in this species.
Eupyrene sperm storage also correlated positively with female size, male age and
spermatophore size. Finally, a new sperm storage site was identified and
described. It is a bulged region in the seminal duct. Copyright 2000 The
Association for the Study of Animal Behaviour.
PMID- 10675263
TI - Can a minority of informed leaders determine the foraging movements of a fish
shoal?
AB - There is no information on whether the daily foraging movements of fish shoals
are the result of chance, the collective will of all shoalmates, or the
leadership of a few individuals. This study tested the latter possibility. Shoals
of 12 golden shiners, Notemigonus crysoleucas, were trained to expect food around
midday in one of the brightly lit corners of their tank. They displayed daily
food-anticipatory activity by leaving the shady area of their tank and spending
more and more time in the food corner up to the normal time of feeding. Past this
normal time they remained in the shade, even on test days when no food was
delivered. Most of these experienced individuals were then replaced by naive
ones. The resulting ratio of experienced:naive fish could be 5:7, 3:9 or 1:11. On
their own, naive individuals would normally spend the whole day in the shade, but
in all tests the experienced individual(s) were able to entrain these more
numerous naive fish out of the shade and into the brightly lit food corner at the
right time of day. Entrainment was stronger in the 5:7 than in the 1:11
experiment. The test shoals never split up and were always led by the same fish,
presumably the experienced individuals. These results indicate that in a strongly
gregarious species, such as the golden shiner, a minority of informed individuals
can lead a shoal to food, either through social facilitation of foraging
movements or by eliciting following behaviour. Copyright 2000 The Association for
the Study of Animal Behaviour.
PMID- 10675264
TI - Courtship role reversal and deceptive signals in the long-tailed dance fly,
Rhamphomyia longicauda.
AB - We examined the function of secondary sexual characters in the role-reversed,
lekking behaviour of female long-tailed dance flies, Rhamphomyia longicauda Loew
(Empididae), to test the hypothesis that the degree of abdominal distention is an
honest female signal about the state of egg development. Female Rhamphomyia
cannot hunt for prey and they receive all of their protein from males by
exchanging copulations for nuptial prey gifts. Females compete for male gifts
within leks that are organized for a brief period each evening before dark.
Before hovering within leks, females swallow air, inflating expandable pouches on
the pleural margins of the abdomen. The result is a large saucer-like abdomen
which is further exaggerated by wrapping scaled pro-, meso- and metathoracic legs
along its pleural margins. Male preference for an enlarged abdomen was confirmed
by suspending plastic models of varying size from monofilament lines and
recording which models attracted the most males. There was a positive
relationship between egg development and abdominal distention in a related
species, R. sociabilis (Williston), which lacks inflatable abdominal pouches.
Multiple regression showed that in R. longicauda, abdominal inflation completely
masks the state of egg development. We conclude that female R. longicauda deceive
mate-seeking males with the unreliable message that eggs are nearing maturation
in order to obtain a protein meal in exchange for copulation. Males that fail to
identify a female bearing mature eggs risk near-certain cuckoldry and an
increased probability that the female will die before oviposition. Copyright 2000
The Association for the Study of Animal Behaviour.
PMID- 10675265
TI - Cheap talk when interests conflict.
AB - Most evolutionary analyses of animal communication suggest that low-cost signals
can evolve only when both the signaller and the recipient rank outcomes in the
same order. When there is a conflict of interest between sender and receiver,
honest signals must be costly. However, recent work suggests that low-cost
signals can be evolutionarily stable, even when the sender and the receiver rank
outcomes in different orders, as long as the interest in achieving coordination
is sufficiently great. In this paper, we extend this body of work by analysing a
game theory model that shows that low-cost signals can evolve when there are
conflicts of interest and no interest in coordination, as long as individuals
interact repeatedly. We also present an empirical example indicating that female
rhesus macaques, Macaca mulatta, use honest, low-cost, vocal signals to
facilitate interactions when conflicts of interest exist. Copyright 2000 The
Association for the Study of Animal Behaviour.
PMID- 10675266
TI - Mechanisms of dispersed central-place foraging in polydomous colonies of the
Argentine ant.
AB - Many species of ants occupy multiple nests, a condition known as polydomy.
Because of their decentralized structure, polydomous colonies may be removed from
some of the constraints associated with classic central-place foraging. We used
laboratory and field experiments to assess the mechanisms involved in dispersed
central-place foraging in polydomous colonies of the Argentine ant Linepithema
humile, a widespread invasive species. Both in the laboratory and in the field,
Argentine ants established new nests at sites located near food. Laboratory
colonies of L. humile redistributed workers, brood and resources among nests in
response to the spatial heterogeneity of food resources. In addition, laboratory
colonies formed recruitment trails between nests in the context of foraging,
providing a mechanism for the transport of material between nests. This highly
flexible system of allocating nests, workers and brood throughout a colony's
foraging area potentially increases foraging efficiency and competitive ability.
The importance of polydomy as a determinant of competitive ability is underscored
by its prevalence among ecologically dominant ants, including most, if not all,
highly invasive species. Copyright 2000 The Association for the Study of Animal
Behaviour.
PMID- 10675267
TI - Female European starling preference and choice for variation in conspecific male
song.
AB - Data from several field studies support the hypothesis that female European
starlings, Sturnus vulgaris, attend to variation among the songs of conspecific
males when making mate-choice decisions. However, for a variety of methodological
reasons, direct evidence for female preferences based on song in starlings has
been lacking. This study presents a novel technique for assaying directly female
preference and choice in European starlings by using the presentation of
conspecific male song as an operant reinforcer in a controlled environment. Using
an apparatus in which the playback of songs from different nestboxes is under the
operant control of the subject, we demonstrate how the reinforcing properties of
conspecific song can be used to measure female preference and choice. The results
of the study suggest three conclusions. First, female starlings prefer naturally
ordered conspecific male songs over reversed songs. Second, female starlings
display robust preferences for longer compared with shorter male song bouts.
Behaviour in the operant apparatus varied directly with male song bout length.
Third, preferences based on song bout length are sex specific. Male starlings
failed to respond differentially to the same stimuli for which females showed
strong preferences. These results suggest that male-male variation in song bout
length is important for mate choice among starlings. In addition, we detail the
use of a novel behavioural assay for measuring female preferences that can be
applied to similar behaviours in other species of songbirds. Copyright 2000 The
Association for the Study of Animal Behaviour.
PMID- 10675268
TI - Male horn dimorphism in the scarab beetle, Onthophagus taurus: do alternative
reproductive tactics favour alternative phenotypes?
AB - In a variety of organisms morphological variation is discrete rather than
continuous. Discrete variation within a sex has attracted particular interest as
it is thought to reflect the existence of alternative adaptations to a
heterogeneous selection environment. The beetle Onthophagus taurus shows a
dimorphism for male horns: males that exceed a critical body size develop a pair
of long, curved horns on their heads, while smaller males remain hornless. In
this study we report on the alternative reproductive tactics used by males with
these two morphologies, and present experimental and behavioural data suggesting
that these alternative tactics selectively favour discretely different male
phenotypes. Horned males aggressively defended tunnel entrances containing
breeding females. Fights involved the use of horns, and males with longer horns
were more likely to win fights. In contrast, hornless males employed
nonaggressive sneaking behaviours when faced with competitively superior males.
Sneaking behaviours appeared to require high degrees of manoeuvrability inside
tunnels to access and mate with females despite the presence of a guarding male.
Comparisons of running performances of males with identical body sizes but
different horn lengths suggest that the possession of horns reduces male agility
inside tunnels. Thus, horn possession confers a clear advantage to males using
fighting behaviours to access females, whereas hornlessness may be favoured in
males that rely primarily on sneaking behaviours. Combined, the two alternative
reproductive tactics used by male O. taurus appear to favour opposite horn
phenotypes, which may explain the paucity of intermediate morphologies in natural
populations of O. taurus. Copyright 2000 The Association for the Study of Animal
Behaviour.
PMID- 10675269
TI - Ligation of ICAM-1 molecules inhibits target cell-induced granule exocytosis of
IL-12-activated natural killer cells.
AB - The importance of cell adhesion molecules such as ICAM-1 is emphasized in cell-to
cell interactions that are critical in the generation of effective immune
reactions. In this study, the involvement of ICAM-1 in natural killer (NK) cell
activities was characterized in IL-12-activated human NK cells. To address the
question of whether ligation of ICAM-1 molecules can modulate NK cell cytolytic
activities, a 4-h (51)Cr-release assay was performed after pretreatment of NK
cells with R6.5 mAb (anti-human ICAM-1 mAb). Ligation of membrane ICAM-1
molecules significantly inhibited IL-12-enhanced NK cytotoxicity against K562,
and the pretreatment of neutralizing soluble ICAM-1 with R6.5 mAb blocked this
inhibitory effect. The involvement of Ca(2+)-dependent granular exocytosis was
evaluated. BLT esterase assay demonstrated that the ligation of ICAM-1 molecules
inhibited granular exocytosis of NK cells. Additionally, the ICAM-1-mediated
inhibition of Ca(2+) flux in NK cells was detected using Fluo-3AM, while the
pretreatment of NK cells with R6.5 mAb did not affect conjugate formation between
NK and K562 cells. Collectively, these results suggest that the signals
transduced from ICAM-1 molecules might be sufficient to induce inhibitory effects
on NK cells.
PMID- 10675270
TI - Regulation of human natural killer cell migration and proliferation by the exodus
subfamily of CC chemokines.
AB - Natural killer (NK) cells play an important role in innate and adaptive immune
responses to obligate intracellular pathogens. Nevertheless, the regulation of NK
cell trafficking and migration to inflammatory sites is poorly understood. Exodus
1/MIP-3alpha/LARC, Exodus-2/6Ckine/SLC, and Exodus-3/MIP-3beta/ELC/CKbeta-11 are
CC chemokines that share a unique aspartate-cysteine-cysteine-leucine motif near
their amino terminus and preferentially stimulate the migration of T lymphocytes.
The effects of Exodus chemokines on human NK cells were examined. Exodus-1, -2,
and -3 did not induce detectable chemotaxis of resting peripheral blood NK cells.
In contrast, Exodus-2 and -3 stimulated migration of polyclonal activated
peripheral blood NK cells in a dose-dependent fashion. Exodus-2 and -3 also
induced dose-dependent chemotaxis of NKL, an IL-2-dependent human NK cell line.
Results of modified checkerboard assays indicate that migration of NKL cells in
response to Exodus-2 and -3 represents true chemotaxis and not simply
chemokinesis. Exodus-1, -2, and -3 did not induce NK cell proliferation in the
absence of other stimuli. Nevertheless, Exodus-2 and -3 significantly augmented
IL-2-induced proliferation of normal human CD56(dim) NK cells. In contrast,
Exodus-1, -2, and -3 did not affect the cytolytic activity of resting or
activated peripheral blood NK cells. Expression of message for CCR7, a shared
receptor for Exodus-2 and -3, was detected in activated polyclonal NK cells and
NKL cells but not resting NK cells. Taken together, these results indicate that
Exodus-2 and -3 can participate in the recruitment and proliferation of activated
NK cells. Exodus-2 and -3 may regulate interactions between T cells and NK cells
that are crucial for the generation of optimal immune responses.
PMID- 10675271
TI - Human leptin enhances activation and proliferation of human circulating T
lymphocytes.
AB - Leptin is an adipocyte-secreted hormone that centrally regulates weight control.
However, leptin receptor is expressed not only in the central nervous system, but
also in other systems such as reproductive and hematopoietic tissues. Human
leptin has previously been shown to enhance cytokine production by murine
peritoneal macrophages and human circulating monocytes. In this paper we have
assessed the presence of leptin receptors in peripheral human T lymphocytes and
we have studied their functional role. Both CD4(+) and CD8(+) T lymphocytes
express leptin receptors. Moreover, we show that human leptin dose-dependently
enhances proliferation and activation of human circulating T lymphocytes when
they are costimulated by PHA or Con A. Leptin alone was not able to activate T
lymphocytes. To confirm a direct effect of leptin on T lymphocytes, monocytes
were extracted by adhesion to culture flasks. The early activation surface marker
CD69 was then induced in both CD4(+) and CD8(+) T lymphocytes after 8 h
stimulation with PHA or Con A. Leptin dose-dependently enhanced stimulated CD69
expression. Moreover, leptin dose-dependently enhanced the expression of the late
activation markers CD25 and CD71 in both CD4(+) and CD8(+) T lymphocytes after 48
h stimulation with PHA or Con A. Finally, we have found that leptin modulates
CD4(+) T lymphocyte activation toward Th1 phenotype by stimulating the synthesis
of IL-2 and IFN-gamma. These results demonstrate the presence of the leptin
receptor in human circulating CD4(+) and CD8(+) T lymphocytes and a functional
role of leptin as a modulator (enhancer) of lymphocyte stimulation with a shift
toward Th1 cytokine-production profile. This function of leptin may have some
relevance in the pathophysiology of immunologic alterations related to obesity.
PMID- 10675272
TI - Synthetic melanin suppresses production of proinflammatory cytokines.
AB - An overproduction of proinflammatory cytokines mediates the damaging sequelae of
inflammation in pathologic conditions such as rheumatoid arthritis, graft-vs-host
reaction, cachexia, and sepsis syndrome. We examined the cytokine regulatory
activity of synthetic melanin, exemplified by biosynthetic l-glycine-l-tyrosine
based polymer (ME-1) and chemosynthetic dihydroxyphenylalanine-based polymer (MC
1). At nontoxic concentrations, both compounds effectively (>/=60%) and
reversibly suppressed the production of tumor necrosis factor (TNF), even when
applied after stimulation of human peripheral blood monocytes with
lipopolysaccharide (LPS). The inhibitory activity of melanin was selective with
regard to cytokine response but not inducer- or cell-type-specific. In addition
to TNF, melanin inhibited production of interleukin (IL)-1beta, IL-6, and IL-10
but not granulocyte-macrophage colony-stimulating factor by the LPS-stimulated
monocytes. Melanin was equally effective in inhibiting production of TNF by
monocytes stimulated with the purified protein derivative of Mycobacterium
tuberculosis and production of IL-6 by IL-1alpha-stimulated human fibroblasts and
endothelial cells. Northern blot analysis, mRNA stability determination,
immunoprecipitation studies on metabolically labeled intracellular TNF, and pulse
chase experiments revealed that melanin reduced efficiency of mRNA translation.
The finding that melanin arrests ongoing cytokine synthesis suggests that this
compound may be useful as an adjunct therapy for conditions showing involvement
of proinflammatory cytokines.
PMID- 10675273
TI - alpha-galactosylceramide induces early B-cell activation through IL-4 production
by NKT cells.
AB - alpha-Galactosylceramide (alpha-GalCer), a glycolipid antigen, specifically
activates natural killer T (NKT) cells by a CD1d-restricted mechanism. In this
work, we found that in vivo administration of alpha-GalCer resulted in the
activation of B cells in addition to NKT cells, namely, alpha-GalCer
administration caused upregulation of the early activation marker, CD69, on both
NKT and B cells. In addition, expression of B7.2 and I-A(b) on B cells was
greatly upregulated by alpha-GalCer. However, serum levels of IgE, IgG1, and
IgG2a were not significantly changed within 48 h. In the present experiments, it
was also demonstrated that the upregulation of CD69 expression by alpha-GalCer
was strongly blocked by anti-IL-4 monoclonal antibody. Moreover, B-cell
activation by alpha-GalCer was not observed in NKT-deficient mice. These results
suggested that antigen-stimulated NKT cells might play a critical role not only
in early defense mechanisms but also in early B-cell activation through IL-4
production.
PMID- 10675274
TI - Macrophage-derived nitric oxide inhibits the proliferation of activated T helper
cells and is induced during antigenic stimulation of resting T cells.
AB - To examine how macrophage-derived nitric oxide (NO) affects T helper (Th) cell
activity, T cell clones representing Th1 and Th2 subsets were activated before
exposure to stimulated peritoneal macrophages or microglia. Both Th subsets were
similarly sensitive to inhibition by NO, indicating that macrophage-derived NO
regulates the proliferation of activated Th1 and Th2 cells equally well. Since
IFN-gamma production remained intact in NO-treated Th1 cells, we studied whether
NO was produced during antigen-specific activation of Th1 cells by unstimulated
macrophages. Indeed, T cell proliferation only occurred when a NO synthase
inhibitor was included, while IFN-gamma was essential for the induction of NO.
These studies demonstrate that macrophages produce NO following antigen
presentation to Th1 cells and that macrophage-derived NO inhibits Th1 and Th2
cell proliferation without inhibiting cytokine production.
PMID- 10675275
TI - Induction of interleukin-12/p40 by superantigens in macrophages is mediated by
activation of nuclear factor-kappaB.
AB - Multimerization of the MHC class II molecule by superantigens results in
activation of cellular signal transduction pathways in macrophage and B cells.
Here we show that superantigen staphylococcal enterotoxin B (SEB) induces IL
12/p40 secretion in macrophages. SEB-induced expression of the IL-12/p40 gene
involves activation and nuclear translocation of nuclear factor kappaB (NF
kappaB). The NF-kappaB heterodimer bound to the NF-kappaB consensus sequence of
the IL-12/p40 gene promoter is p50/C-Rel. Inhibition of PKC and PKA activation
results in suppression of activation and translocation of NF-kappaB. We conclude
that signals for IL-12/p40 gene transcription from MHC class II molecules follow
activation of PKC and PKA, which in turn leads to the activation and
translocation of NF-kappaB to the nucleus. Our study suggests that superantigens
are capable of influencing the nature of the immune response by regulating
cytokine production. Induction of IL-12 production by superantigens may therefore
play a role in the regulation of Th 1-mediated immune response and autoimmune
disease.
PMID- 10675276
TI - Injection of plasmid DNA into the gastric mucosa induces mucosal and systemic
immunity.
AB - Nearly all mucosal surfaces participate in a common mucosal immune system, and
application of an antigen to one mucosal surface elicits local as well as distant
mucosal immune responses. However, whether the gastric mucosa is a part of this
network has not been examined directly. We show here that the injection of
plasmid DNA encoding beta-galactosidase into the gastric wall caused transfection
of gastric mucosal epithelial cells, induced systemic and mucosal antibody
responses at both local (digestive tract) and distant (genital and respiratory
tracts) sites, and induced cytotoxic T lymphocyte responses in the spleen and the
mesenteric and iliac lymph nodes.
PMID- 10675277
TI - Is there a rationale for the use of creatine either as nutritional
supplementation or drug administration in humans participating in a sport?
AB - Even though no unambiguous proof for enhanced performance during high-intensity
exercise has yet been reported, the creatine administration is charged to improve
physical performance and has become a popular practice among subjects
participating in different sports. Appropriate creatine dosage may be also used
as a medicinal product since, in accordance with the Council Directive 65/65/CEE,
any substance which may be administered with a view to restoring, correcting or
modifying physiological functions in human beings is considered a medicinal
product. Thus, quality, efficacy and safety must characterize the substance. In
biochemical terms, creatine administration enhances both creatine and
phosphocreatine concentrations, allowing for an increased total creatine pool in
skeletal muscle. In thermodynamics terms, creatine interferes with the creatine
creatine kinase-phosphocreatine circuit, which is related to the mitochondrial
function as a highly organized system for the energy control of the subcellular
adenylate pool. In pharmacokinetics terms, creatine entry into skeletal muscle is
initially dependent on the extracellular concentration, but the creatine
transport is subsequently down-regulated. In pharmacodynamics terms, the creatine
enhances the possibility to maintain power output during brief periods of high
intensity exercises. In spite of uncontrolled daily dosage and long-term
administration, no research on creatine safety in humans has been set up by
specific standard protocol of clinical pharmacology and toxicology, as currently
occurs in phase I for the products for human use. More or less documented side
effects induced by creatine are weight gain; influence on insulin production;
feedback inhibition of endogenous creatine synthesis; long-term damages on renal
function. A major point that related to the quality of creatine products is the
amount of creatine ingested in relation to the amount of contaminants present.
During the production of creatine from sarcosine and cyanamide, variable amounts
of contaminants (dicyandiamide, dihydrotriazines, creatinine, ions) are generated
and, thus, their tolerable concentrations (ppm) must be defined by specific
toxicological researches. Creatine, as the nutritional factors, can be used
either at supplementary or therapeutic levels as a function of the dose.
Supplementary doses of nutritional factors usually are of the order of the daily
turnover, while therapeutic ones are three or more times higher. In a subject
with a body weight of 70 kg with a total creatine pool of 120 g, the daily
turnover is approximately 2 g. Thus, in healthy subjects nourished with a fat
rich, carbohydrate-, protein-poor diet and participating in a daily recreational
sport, the oral creatine supplementation should be on the order of the daily
turnover, i.e. less than 2.5-3 g per day, bringing the gastrointestinal
absorption to account. In healthy athletes submitted daily to high-intensity
strength- or sprint-training, the maximal oral creatine supplementation should be
on the order of two times the daily turnover, i.e. less than 5-6 g per day for
less than 2 weeks, and the creatine supplementation should be taken under
appropriate medical supervision. The oral administration of more than 6 g per day
of creatine should be considered as a therapeutic intervention because the dosage
is more than three times higher than the creatine daily turnover and more than
six times higher than the creatine daily allowance. In this case, creatine
administration should be prescribed by physicians only in the cases of suspected
or proven deficiency, or in conditions of severe stress and/or injury. 2000
Academic Press@p$hr
PMID- 10675278
TI - Pepsinogens: physiology, pharmacology pathophysiology and exercise.
AB - Human gastric mucosa contains aspartic proteinases that can be separated
electrophoretically on the basis of their physical properties into two major
groups: Pepsinogen I (PGA, PGI); and Pepsinogen II (PGC, PGII). Pepsinogens
consist of a single polypeptide chain with molecular weight of approximately
42,000 Da. Pepsinogens are mainly synthesized and secreted by the gastric chief
cells of the human stomach before being converted into the proteolytic enzyme
pepsin, which is crucial for the digestive processes in the stomach. Pepsinogen
synthesis and secretion are regulated by positive and negative feed-back
mechanisms. In the resting state pepsinogens are stored in granules, which
inhibit further synthesis. After appropriate physiological or external chemical
stimuli, pepsinogens are secreted in the stomach lumen where hydrochloric acid,
secreted by the parietal cells, converts them into the corresponding active
enzyme pepsins. The stimulus-secreting coupling mechanisms of pepsinogens appear
to include at least two major pathways: one involving cAMP as a mediator, the
other involving modification of intracellular Ca(2+)concentration. Physiological
or external chemical stimuli acting through the intracellular metabolic adenyl
cyclase are more effective in inducing ' de novo ' pepsinogen synthesis than
those acting through intracellular Ca(2+). The activation of protein kinase C (PK
C) would appear to be involved in regulatory processes. The measurement of
pepsinogens A and C in the serum is considered to be one of the non-invasive
biochemical markers for monitoring peptic secretion and obtaining information on
the gastric mucosa status of healthy subjects. Recently, pepsinogen measurements
have been used as an effective biochemical method for evaluating and monitoring
patients with gastrointestinal diseases and for checking the effects of drug
treatment. The level of PGA in the serum is always high in normal gastritis,
while in atrophic gastritis it is always low. In both cases the PGC level in the
serum is high. In most gastrointestinal pathologies the ratio between the PGA/PGC
decreases. Various reports concerning hormone and/or enzyme modification as well
as gastrointestinal distress in the case of long distance exercise have been
reported. It has been suggested that the origin of the gastrointestinal distress
experienced by long distance runners is a transient ischaemia of the gastric
mucosa; it is also suggested that a hypobaric-hypoxic environment could
contribute to induce gastric mucosa necrosis. Interrelation between
gastrointestinal distress, hypobaric-hypoxic environment and modifications of PGA
and PGC, gastrin and cortisol was evaluated in 13 athletes after a marathon
performed at 4300 m. Gastrointestinal symptoms occurred in approximately 40% of
the athletes. After the race the athletes showed a significant increase of
gastrin and cortisol, while the ratio between PGA/PGC decreased. No relationship
was observed between gastrointestinal symptoms and hormonal changes after the
race. A control group of five subjects, who had been exposed to the same
environmental conditions, showed no gastrointestinal or hormonal alteration.
Conversely, control subjects presented a significant decrease of cortisol related
to the circadian rhythm. The same incidence of gastrointestinal symptoms at high
altitude and at sea level and the absence of pathological alteration of PGA and
PGC in the serum of the athletes indicates that running a marathon and living for
6 days at 4300 m does not induce gastric mucosa necrosis. Cortisol and gastrin
alteration observed in the athletes at this altitude would seem to be related to
an activation of the mesopontine and forebrain structures involved in the
behavioural and metabolic integration of the autonomic control and arousal and
psychophysical-exercise stress. 2000 Academic Press@p$hr
PMID- 10675279
TI - Protective effect of thymoquinone against doxorubicin-induced cardiotoxicity in
rats: a possible mechanism of protection.
AB - Administration of thymoquinone (10 mg kg(-1)day(-1), p.o.) with drinking water
starting 5 days before a single injection of doxorubicin (15 mg kg(-1)i.p.) and
continuing during the experimental period ameliorated the doxorubicin-induced
cardiotoxicity in rats. This protection was evidenced from the significant
reduction in serum enzymes: lactate dehydrogenase elevated level, 24 h and
creatine phosphokinase elevated levels, 24 h and 48 h after doxorubicin
administration. The cardiotoxicity of doxorubicin has been suggested to result
from the generation of superoxide free-radical. The protective action of
thymoquinone was examined against superoxide anion radical either generated
photochemically, biochemically or derived from calcium ionophore (A23187)
stimulated polymorphonuclear leukocytes. The results indicate that thymoquinone
is a potent superoxide radical scavenger, scavenging power being as effective as
superoxide dismutase against superoxide. In addition thymoquinone has an
inhibitory effect on lipid peroxidation induced by Fe(3+)/ascorbate using rat
heart homogenate. The superoxide scavenging and anti-lipid peroxidation may
explain, in part, the protective effect of thymoquinone against doxorubicin
induced cardiotoxicity. 2000 Academic Press@p$hr
PMID- 10675280
TI - The potentiation of the histamine release induced by adenosine in mast cells from
guinea pig lung and heart: sharp dependence on the time of preincubation.
AB - We studied here the effect of a wide range of adenosine concentration and time of
preincubation, on the histamine release induced in the guinea pig mast cells by
different stimulus. Adenosine (10(-5)-10(-3)m) potentiated the histamine release
induced by antigen in the guinea pig heart (isolated and dispersed tissue) and
lung mast cells but not induced by ionophore A23197. The potentiation caused by
adenosine (10(-4)m) was maximum after 1-3 min of preincubation and is probably an
extracellular effect since it was not avoided by dipyridamol (3x10(-7)-10(-6)m)
that inhibit the uptake of adenosine. Similar potentiation was also produced by
the adenosine mimetic 2-chloroadenosine (10(-5)m) and both effects were inhibited
by 8-phenyltheophylline indicating an effect on the type A receptors. It is
suggested that the adenosine potentiation may not be related to changes on the
cyclic AMP levels. 2000 Academic Press@p$hr
PMID- 10675281
TI - Effect of dl-alpha-lipoic acid on the status of lipid peroxidation and
antioxidants in aged rats.
AB - The effect of dl-alpha-lipoic acid on lipid peroxidation and antioxidants status
has been studied in the blood of young and aged rats. dl-alpha-lipoic acid, an
antioxidant, was administered intraperitoneally for 7 and 14 days. Enzymatic and
non-enzymatic antioxidant levels decreased with age but this decrease was
attenuated by dl-alpha-lipoic acid. Lipid peroxide levels increased with age, and
were decreased by lipoic acid administration. These results suggest that
biochemical lesions which are considered to be part of the normal ageing process
are neutralized by dl-alpha-lipoic acid.
PMID- 10675282
TI - The effect of colchicine on proximal tubular reabsorption.
AB - Aquaporins, expressed in the brush border membrane (BB) could play a pivotal role
in glomerulo-tubular balance (GTB) by effecting adaptive changes of water
permeability to the variations in the load of filtered solutes. Since aquaporin
expression is modulated by microtubule-dependent trafficking between endoplasmic
reticulum and cell membranes, we used the microtubule poison colchicine to assess
the importance of aquaporins in mediating GTB. The effects of colchicine 1.6x10(
4)m on proximal tubule volume reabsorption was tested on 48 nephrons of ten rats
by micropuncture techniques. Thirty proximal tubules were sampled from the last
proximal convolution before, and recollected during and again after the
microinjection (MIJ), into the early proximal convolution or Bowman's space, of
colchicine added to a Ringer solution. We studied 18 proximal tubules in the same
way before, during and after the microperfusion (MP) of colchicine added to an
ultrafiltrate of plasma into the peritubular capillaries. During MIJ, SNGFR did
not change significantly from baseline (17.7+/-1.3 vs 20.9+/-1.8 nl min(-1),
P>0.12). Post-control values were superimposable upon their paired pre-MIJ
controls, when available (15.8+/-1.3 vs 13.5+/-1.5 nl min(-1), P>0.25). The
measurements of percentage reabsorption (49+/-5 during baseline, 45+/-7 during
MIJ, and 55+/-5 in post-control, P>0.6) and absolute reabsorption (8.1+/-0.7,
11.1+/-2. 2, and 7.9+/-1.3 nl min(-1), respectively, P>0.18) were also unchanged.
The three average measurements obtained in control conditions, during MP and
again in post-MP control were not significantly different for SNGFR (19.8+/-3.0,
20.0+/-4.7, and 20. 2+/-3.5 nl min(-1), P>0.48), percentage (55+/-3, 59+/-5, and
47+/-3%, P>0.35) and absolute reabsorptions (12.5+/-2.2, 12.4+/-4.6, and 9. 4+/
1.0 nl min(-1), respectively, P>0.42). MIJ and MP of vehicles were devoid of any
measurable effect. Colchicine does not acutely affect volume reabsorption in the
proximal tubule. Aquaporin trafficking, if any, is not involved in mediating
glomerulotubular balance in the proximal tubule, although aquaporin expression
and function could still be important, although regulated by mechanisms different
from microtubule-dependent shuttling between endoplasmic reticulum and BB.
PMID- 10675283
TI - Detection of anti-erythropoietin antibodies in haemodialysis patients treated
with recombinant human-erythropoietin.
AB - An enzyme-immunoassay was developed to evaluate the presence of anti
erythropoietin antibodies in plasma samples obtained from renal failure patients
treated with recombinant human erythropoietin (rh-EPO). The assay was specific
and reproducible. Normal donors had no antibodies to EPO, while 67% of treated
patients were positive to the assay. While the specificity of anti-EPO IgG
antibodies was high, their affinity for the antigen was low. This finding can be
explained by the very small differences in the structure of rh-EPO compared to
that of natural EPO. The assay described could be useful in evaluating the long
term effects of rh-EPO treatment on the control of anaemia in renal failure
patients.
PMID- 10675284
TI - Role of Moringa oleifera leaf extract in the regulation of thyroid hormone status
in adult male and female rats.
AB - The role of Moringa oleifera aqueous leaf extract in the regulation of thyroid
hormone status, was studied in adult Swiss rats. Other than the thyroid hormone
concentrations, hepatic lipid peroxidation (LPO) and the activities of
antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) were
evaluated. In the first experiment, effects of the leaf extract (175 mg kg(
1)body wt. day(-1)for 10 days) were studied both in male and female animals.
Following the administration of the extract, serum triiodothyronine (T(3))
concentration and hepatic LPO decreased with a concomitant increase in the serum
thyroxine (T(4)) concentration, in female rats, while in males no significant
changes were observed, suggesting that Moringa oleifera leaf extract is more
effective in females than in the males. To evaluate the impact of a higher dose,
in the second experiment, the study was repeated in female rats, with 350 mg kg(
1)body wt. day(-1)for the same duration. Almost similar reduction in the serum
T(3)concentration (approx. 30%) and an increase in the T(4)concentration were
observed suggesting the inhibiting nature of Moringa oleifera leaf extract in the
peripheral conversion of T(4)to T(3), the principal source of the generation of
latter hormone. As the antiperoxidative effects were exhibited only by the lower
dose and percent decrease in T(3)concentration was nearly the same by both the
doses, it is suggested that the lower concentration of this plant extract may be
used for the regulation of hyperthyriodism. 2000 Academic Press@p$hr
PMID- 10675285
TI - Modulation of N-type calcium channels translocation in RINm5F insulinoma cells.
AB - An intracellular pool of N-type voltage-operated calcium channels has recently
been described in both IMR32 human neuroblastoma and PC12 rat pheochromocytoma
cells. These channels were found to be accumulated in subcellular fractions where
the chromogranin B-containing secretory granules were also enriched. Upon
exocytosis N-type calcium channels were reversibly inserted in the plasma
membrane. We have now extended this study to RINm5F rat insulinoma cells, and
characterized the parallelism between the 'regulated' secretion of serotonin and
the recruitment of surface calcium channels. Exocytosis was stimulated by
different means, such as depolarization with high KCl, high Ba(2+)alone or
protein kinase C activation; on the other hand exocytosis was inhibited with the
non-selective calcium channel antagonist Cd(2+)or with noradrenaline. Stimulated
release was always accompanied, with parallel kinetics, by calcium channel
recruitment, while inhibition of secretion blocked calcium channel recruitment
too. During repetitive depolarizations we revealed a potentiation of [Ca(2+)]()i
transients in single Fura-2 loaded RINm5F cells, that was accompanied by an
increase in surface VOCCs, suggesting a physiological role for the newly
recruited channels. 2000 Academic Press@p$hr
PMID- 10675286
TI - Inhibitory effect of KT3-671, a non-peptide angiotensin subtype 1 receptor
antagonist, on sympathetic neurotransmission in isolated rabbit aorta.
AB - Effect of KT3-671 on the sympathetic neurotransmission in isolated rabbit aorta
was studied and compared with those of losartan and its active metabolite,
EXP3174. Angiotensin (Ang) II (30 n m) produced approximately 1.7-fold increase
in the transmural nerve stimulation (TNS)-evoked tritium overflow in the aorta
preloaded with [(3)H]noradrenaline. KT3-671 (1 microm) by itself did not alter
the TNS-evoked tritium overflow but it (0.1-1 microm) concentration-dependently
inhibited the enhancing effect of Ang II on the TNS-evoked tritium overflow. Both
losartan (1 and 3 microm) and EXP3174 (0.03-0.3 microm) also inhibited the Ang II
effect. KT3-671 was approximately 8.6 and 0.3 times more potent than losartan and
EXP3174, respectively, in inhibiting the Ang II response. This is consistent with
the previous results showing the relative potency of the three antagonists to
block AT(1)receptors. None of Ang II, KT3-671, losartan and EXP3174 affected
significantly the spontaneous tritium outflow. These results suggest that KT3-671
as well as losartan and EXP3174 may inhibit vascular sympathetic
neurotransmission by blocking presynaptic Ang II subtype 1 receptors, which
appears to contribute partly to its antihypertensive action. 2000 Academic
Press@p$hr
PMID- 10675287
TI - Noradrenaline, dopamine, serotonin: different effects of psychological stress on
brain biogenic amines in mice and rats.
AB - The effect of restraint stress on central neurotransmission was evaluated in mice
and rats. Noradrenaline (NA), dopamine (DA) and serotonin (5-HT) levels and their
primary metabolites were measured in discrete brain regions following exposure to
stress. Mice and rats demonstrated a similar response to stress in some brain
regions. Both species responded to stress with lower NA and 5-HT in the locus
coeruleus compared to non-stressed controls. Dopaminergic activity, assessed by
DA turnover, was elevated in the hypothalamus. While DA turnover was suppressed
in the amygdala, 5-HT turnover was similarly elevated in both species. In most
cases, however, there were differences in biogenic neurotransmission between mice
and rats in response to stress. In particular, NA levels were suppressed by
stress in the dorsal cortex of mice, but in the rats NA levels were decreased in
the hypothalamus. While stress produced lower DA levels in the hypothalamus, DA
levels demonstrated a marked increase in the amygdala of mice. Stress was also
associated with a decrease in DA levels in the rat striatum and with an increase
of DA turnover in the locus coeruleus of mice. On the other hand, 5-HT was
suppressed in the mouse striatum and in the rat hypothalamus and amygdala, while
5-HT turnover was markedly decreased in the hippocampus and dorsal cortex of rats
alone. In conclusion, the changes in the central neurotransmission which are
evoked by stress appear to be species-specific in most cases, a fact which may
trigger discrete alterations in homeostatic mechanisms.
PMID- 10675288
TI - Bilateral 6-OHDA lesions to the hippocampus attenuate the facilitatory effect of
CCK-8 us and caerulein on memory in rats.
AB - The involvement of dopaminergic projection to the hippocampus in the facilitatory
effect of cholecystokinin-unsulphated octapeptide (CCK-8 us) and caerulein (CER)
on memory motivated affectively was investigated in male rats. CCK-8 us and CER
were given subcutaneously at the doses of 10 microg kg(-1)and 0.5 microg kg(-1),
respectively, immediately after a single learning trial in a passive avoidance
situation, after bilateral 6-OHDA lesions to the dentate gyrus of the
hippocampus. In order to protect noradrenergic neurones against destruction by
neurotoxin, 30 min before surgery rats were pre-treated intraperitoneally with 25
mg kg(-1)of desmethylimipramine, an inhibitor of noradrenaline uptake. Bilateral
6-OHDA lesions to the hippocampus significantly attenuate the facilitatory effect
of CCK-8 us and CER on retention of passive avoidance behaviour evaluated 24 h
after the learning trial. Neither, destruction of dopaminergic endings in the
hippocampus, nor application of CCK-8 us and CER changed the spontaneous
psychomotor activity of rats estimated in an 'open field' test. These results may
indicate that the facilitatory effect of CCK-8 us and CER on memory motivated
affectively is, in part, mediated by dopaminergic projection from the ventral
tegmental area to the dentate gyrus of the hippocampus.
PMID- 10675289
TI - Antinociceptive effect of amikacin and its interaction with morphine and
naloxone.
AB - Amikacin sulphate (30 mg kg(-1)) administered either intraperitoneally (i.p.) or
subcutaneously (s.c.) produced antinociceptive effect in BALB/c mice in the
acetic acid writhing test which is employed as an inflammatory pain model. The
lack of difference between two routes with regard to antinociceptive potency was
taken as evidence for the absence of a local effect. Amikacin sulphate-induced
antinociception seems unlikely to be due to non-specific behaviour alteration,
since this drug, at a dose range of 15-100 mg kg(-1)did not affect motor
coordination of mice in rot-a-rod test. Morphine (1 mg kg(-1)) also caused
antinociception when administered i.p. or s.c. but the effect was greater with
the latter route. At the i.p. site; the concurrent use of amikacin and morphine
produced more remarkable antinociception compared to their individual usages.
Besides, naloxone (2 mg kg(-1)) significantly decreased antinociceptive effect of
amikacin but itself also exerted antinociception. At present, we have no
plausible explanation for these findings at the i.p. site.
PMID- 10675290
TI - The hamster heart: a paradox in itself.
AB - Perfusion of all mammalian heart muscle except hamster with Ca(2+)-free Tyrode
and thereafter reperfusion with normal Tyrode causes irreversible damage, the
calcium paradox. Our study aims at deciphering the role of creatine kinase, high
energy phosphates and Ca(2+)influx in the genesis of myocardial injury in the rat
and comparing it with the hamster. Isolated hearts from hamster and rats were
perfused in the Langendorff mode at 37 degrees C for 30 min with normal Tyrode,
for 15 min with Ca(2+)-free Tyrode and thereafter for 30 min of reperfusion with
normal Tyrode. The 'high energy phosphate compound' levels were monitored by(31)P
NMR, creatine kinase (CK) release was measured in the perfusate.(45)Ca influx was
estimated in the papillary muscle. We observed that in the rat heart: (a) high
energy phosphate levels declined significantly within 1 min of Ca(2+)reperfusion;
(b) a massive release of CK occurred upon Ca(2+)reperfusion; (c) there was a
significant increase of Ca(2+)influx. In the hamster heart, there was
preservation of high energy phosphates, CK release was prevented completely and
no rise in(45)Ca influx was observed upon Ca(2+)reperfusion. These results
suggest that the hamster heart has a remarkable capacity for Ca(2+)homeostasis
which protects the heart from Ca(2+)overload.
PMID- 10675291
TI - Mechanism of the hypotensive action of Rhazya stricta leaf extract in rats.
AB - The hypotensive action of Rhazya stricta lyophilized leaf extract was found to be
partly caused by the electrolyte content of the extract, and partly caused by a
strongly basic alkaloidal fraction (AF). AF (0.05-1.6 mg animal(-1)) caused a
dose-dependent reduction in mean arterial blood pressure (MAP) of urethane
anaesthetized rat preparations. In naiuml;ve pithed rats, AF administration (0.5
2.0 mg animal(-1)) significantly increased MAP. In pithed or spinalized rats made
normotensive by noradrenaline infusion, AF (0.25 mg animal(-1)) did not cause any
significant changes. Direct intracerebroventricular injection of AF (0.1-0.4 mg)
markedly and significantly reduced MAP. It is suggested that the hypotensive
action of AF to be mediated by a central mechanism.
PMID- 10675292
TI - Three-dimensional structure of a vertebrate muscle Z-band: implications for titin
and alpha-actinin binding.
AB - The Z-band in vertebrate striated muscles, mainly comprising actin filaments,
alpha-actinin, and titin, serves to organise the antiparallel actin filament
arrays in adjacent sarcomeres and to transmit tension between sarcomeres during
activation. Different Z-band thicknesses, formed from different numbers of zigzag
crosslinking layers and found in different fibre types, are thought to be
associated with the number of repetitive N-terminal sequence domains of titin. In
order to understand myofibril formation it is necessary to correlate the
ultrastructures and sequences of the actin filaments, titin, and alpha-actinin in
characteristic Z-bands. Here electron micrographs of the intermediate width,
basketweave Z-band of plaice fin muscle have been subject to a novel 3D
reconstruction process. The reconstruction shows that antiparallel actin
filaments overlap in the Z-band by about 22-25 nm. There are three levels of Z
links (probably alpha-actinin) in which at each level two nearly diametrically
opposed links join an actin filament to two of its antiparallel neighbours. One
set of links is centrally located in the Z-band and there are flanking levels
orthogonal to this. A 3D model of the observed structure shows how Z-bands of
different widths may be formed and it provides insights into the structural
arrangements of titin and alpha-actinin in the Z-band. The model shows that the
two observed symmetries in different Z-bands, c2 and p12(1), may be attributed
respectively to whether the number of Z-link levels is odd or even.
PMID- 10675293
TI - Complementary visualization of mitotic barley chromatin by field-emission
scanning electron microscopy and scanning force microscopy.
AB - The surface structure of mitotic barley chromatin was studied by field-emission
scanning electron microscopy (FESEM) and scanning force microscopy (SFM).
Different stages of the cell cycle were accessible after a cell suspension was
dropped onto a glass surface, chemical fixed, and critically point dried. Imaging
was carried out with metal-coated specimen or uncoated specimen (only for SFM).
The spatial contour of the chromatin could be resolved by SFM correlating to
FESEM data. The experimentally determined volume of the residue chromatin during
mitosis was within the range of 65-85 microm(3). A comparison with the
theoretically calculated volume indicated a contribution of about 40% of internal
cavities. Decondensation of chromosomes by proteinase K led to a drastic decrease
in the chromosome volume, and a 3-D netlike architecture of the residue
nucleoprotein material, similar to that in the intact chromosome, was obvious.
Incubation of metaphase chromosomes in citrate buffer permitted access to
different levels of chromatin packing. We imaged intact chromosomes in liquid by
SFM without any intermediate drying step. A granular surface was obvious but with
an appreciably lower resolution. Under similar imaging conditions proteinase K
treated chromosomes exhibited low topographic contrast but were susceptible to
plastic deformations.
PMID- 10675294
TI - Structural organization of posterior midgut muscles in mosquitoes, Aedes aegypti
and Anopheles gambiae.
AB - In order to adapt to diverse feeding behavior, animal intestines have evolved
with distinct differences. Such adaptation may include the structure of the
longitudinal and circular muscles that maintain the integrity and the tensile
strength of the gut tissue in higher metazoans. Here we examined the structural
organization of the posterior midgut muscles of two insects, Aedes aegypti and
Anopheles gambiae. We found the estimated number of longitudinal muscles in a
cross-section to be 168 in Ae. aegypti and 37 in An. gambiae. Within the region,
the estimated number of circular muscles is 77 in Ae. aegypti and 57 in An.
gambiae. In An. gambiae, longitudinal muscles appear as sets of parallel bundles.
Each set overlaps its neighbor to form a continuous tube. We found that this
novel mode of muscle fiber sharing makes all circular muscles interconnected.
Both types of muscle lie orthogonally to form a grid that holds the epithelium of
the posterior midgut. In Ae. aegypti, the muscle fibers between the bundles are
shared extensively, making the organization more intricate. This study implies
that, because of its simple structure, the insect midgut may provide a powerful
tool with which to study the structural evolution and function of animal
intestines.
PMID- 10675295
TI - Structure of abnormal molecular assemblies (collagen VI) associated with human
full thickness macular holes.
AB - Transversely banded deposits with an approximately 100-nm periodicity have been
seen in association with a number of eye pathologies (e.g., age-related macular
degeneration). Recently such aggregates have also been discovered in the cortical
vitreous of a patient suffering from full thickness macular holes. The aggregates
in the vitreous were of sufficient size and regularity for us to attempt 3D
ultrastructural studies in the electron microscope. The molecules forming this
aggregate pack in a centered tetragonal unit cell of dimensions approximately 26
x 26 x 180 nm. A real-space (r-weighted back projection) 3D reconstruction was
computed. The aggregate is discussed in terms of its possible protein
constituents. Collagen VI has been singled out as the most likely protein to form
the aggregate. Two alternative models for the molecular packing are proposed,
comprising aggregates of molecular tetramers or octamers. Understanding the
structure of these abnormal banded deposits in the eye should help to throw light
on the pathophysiological mechanisms of the diseases, including age-related
macular degeneration, in which they occur.
PMID- 10675296
TI - Cryo-electron tomography of neurospora mitochondria.
AB - Cryo-electron tomography was used to study the structural organization of whole
frozen-hydrated mitochondria from Neurospora crassa. Unlike mitochondria from
many other species and tissues, in this case the cristae form a three-dimensional
network of interconnected lamellae. Basically, the three-dimensional structure of
ice-embedded mitochondria from this species is consistent with previous
descriptions of mitochondria prepared by chemical fixation and resin embedding.
Nonetheless, ice-embedded mitochondria display some important differences: the
outer surface of the mitochondria was found to be rather smooth, the
intermembrane space was constant in width, and distinct contact sites between the
membranes were clearly revealed. Furthermore ATP synthase particles on the outer
surface of an "inside-out vesicle" were visible in 3-D reconstructions. Thus,
cryo-electron tomography can provide detailed insights into these organelles with
minimal perturbations of the physiological state. This indicates that it is a
realistic goal to achieve "molecular resolution" with rather large biological
specimens in the near future, ultimately allowing the identification and
localization of macromolecules in their cellular context.
PMID- 10675297
TI - Quantitative microscopy of fluorescent adenovirus entry.
AB - Fluorescence imaging of cells is a powerful tool for exploring the dynamics of
organelles, proteins, and viruses. Fluorescent adenoviruses are a model system
for cargo transport from the cell surface to the nucleus. Here, we describe a
procedure to quantitate adenovirus-associated fluorescence in different
subcellular regions. CCD camera-captured fluorescence sections across entire
cells were deblurred by a fast Fourier transformation, the background was
subtracted images merged, and virus fluorescence quantitated. The validity of the
deblurring routine was verified by confocal laser scanning microscopy,
demonstrating that objects were neither generated nor deleted. Instead, the
homogeneity of both the average intensity and the size of fluorescent particles
was increased, facilitating automated quantification. We found that nuclear
fluorescence of wt adenovirus, but not of a virus mutant ts1, which fails to
escape from endosomes, was maximal at 90 min postinfection (p.i.). Surprisingly,
nuclear fluorescence decreased at 120 min, but increased again at 240 min p.i.,
suggesting that wt virus targeting to the nucleus may be multiphasic and
regulated. Interestingly, only the first nuclear transport period of wt but not
ts1 virus coincided with a significant increase of the peripheral and decrease of
the cytoplasmic regions, indicative of signal-dependent cell contraction.
PMID- 10675298
TI - The crystal structure of beta-glucosidase from Bacillus circulans sp.
alkalophilus: ability to form long polymeric assemblies.
AB - Family 1 of glycosyl hydrolases is a large and biologically important group of
enzymes. A new three-dimensional structure of this family, beta-glucosidase from
Bacillus circulans sp. alkalophilus is reported here. This is the first structure
of beta-glucosidase from an alkaliphilic organism. The model was determined by
the molecular replacement method and refined to a resolution of 2.7 A. The
quaternary structure of B. circulans sp. alkalophilus beta-glucosidase is an
octamer and subunits of the octamer show a similar (beta/alpha)(8) barrel fold to
that previously reported for other family 1 enzymes. The crystal structure
suggested that Cys169 in the active site is substituted. The Cys169 is located
near the putative acid/base catalyst Glu166 and it may contribute to the high pH
optimum of the enzyme. The crystal structure also revealed that the asymmetric
unit contains two octamers which have a clear binding interaction with each
other. The ability of the octamers to link with each other suggested that beta
glucosidase from Bacillus circulans sp. alkalophilus is able to form long
polymeric assemblies, at least in the crystalline state.
PMID- 10675299
TI - Cryoelectron microscopy of protein-lipid complexes of human myelin basic protein
charge isomers differing in degree of citrullination.
AB - Myelin basic protein (MBP) is considered to be essential for the maintenance of
stability of the myelin sheath. Reduction in cationicity of MBP, especially due
to conversion of positively charged arginine residues to uncharged citrulline
(Cit), has been found to be associated with multiple sclerosis (MS). Here, the
interactions of an anionic phosphatidylserine/monosialoganglioside-G(M1) (4:1,
w:w) lipid monolayer with 18.5-kDa MBP preparations from age-matched adult humans
without MS (no Cit residues), with chronic MS (6 Cit), and with acute Marburg
type MS (18 Cit) were studied by transmission and ultralow dose scanning
transmission electron microscopy under cryogenic conditions. Immunogold labeling
and single particle electron crystallography were used to define the nature of
the complexes visualized. These electron microscopical analyses showed that the
three different MBP charge isomers all formed uniformly sized and regularly
shaped protein-lipid complexes with G(M1), probably as hexamers, but exhibited
differential association with and organization of the lipid. The least cationic
Marburg MBP-Cit(18) formed the most open protein-lipid complex. The data show a
disturbance in lipid-MBP interactions at the ultrastructural level that is
related to degree of citrullination, and which may be involved in myelin
degeneration in multiple sclerosis.
PMID- 10675300
TI - Crystallization and 1.1-A diffraction of chorismate lyase from Escherichia coli.
AB - Chorismate pathway enzymes are important as producers of nonnucleotide aromatic
compounds. The enzyme chorismate lyase from Escherichia coli has been
crystallized in four distinct forms, three of which have been characterized by X
ray diffraction. Despite widespread screening, all four crystal forms grow from
the same chemical conditions. The wild-type enzyme tends to aggregate, even in
the presence of reducing agent, and yielded only one crystal form (monoclinic,
form 1) that grew in intricate clusters. Chemical modification of the cysteines
mitigated problems with aggregation and solubility but did not affect crystal
growth behavior. Protein aggregation was largely eliminated by mutating the
protein's two cysteines to serines. The double mutant retains full enzymatic
activity and crystallizes in three new forms, one of which (triclinic) diffracts
to 1.1-A resolution.
PMID- 10675301
TI - A unique Hawaiian Schiedea (caryophyllaceae: Alsinoideae) with only five fertile
stamens.
AB - The floral organogenesis and subsequent ontogenies of the Hawaiian endemic
species Schiedea pubescens from Maui, Moloka'i, and Lana'i, and the Wai'anae
Mountains, O'ahu, populations previously considered to be varietally distinct,
were examined using the scanning electron microscope (SEM). The O'ahu population
consistently produced only five fertile stamens, those of the inner whorl. The
five stamens of the alternisepalous or outer whorl abort prior to
microsporogenesis and fail to elongate. Additional vegetative differences between
the two taxa, combined with the floral morphology characters, merit the
description of the O'ahu population as a new species, S. pentandra, described
herein.
PMID- 10675302
TI - Comparative pollen morphology and ultrastructure of the Callitrichaceae.
AB - The Callitrichaceae are an aquatic family of dicots that include the single,
geographically cosmopolitan genus Callitriche. Callitriche contains 40-50
terrestrial, amphibious, and obligately submersed species, and it is the only
known genus in the plant kingdom with co-occurring aerial and hydrophilous
pollination syndromes. Pollen morphology and ultrastructure were described for 13
Callitriche species using scanning electron and transmission electron microscopy.
Representative taxa of each growth form were examined; these included three
terrestrial species (C. deflexa, C. peploides, and C. nuttallii), nine amphibious
species (C. brutia, C. cophocarpa, C. cophocarpa-stagnalis hybrid, C. cribrosa,
C. hamulata, C. heterophylla var. heterophylla, C. lusitanica, C. marginata, and
C. trochlearis), and one obligately submersed species (C. truncata). Of the
amphibious taxa, C. heterophylla var. heterophylla and C. trochlearis had
internal geitonogamy, a type of internal self-fertilization. Pollen from all taxa
was spheroidal, small, intectate, and lacked well-defined apertures. Taxa
primarily differed with respect to exine thickness, surface ornamentation, and
the presence or absence of aperture-like regions. The pollen of terrestrial
species, as well as that of C. marginata, had well-developed exines with thick
sculptured and basal layers. In general, amphibious taxa produced pollen with
distinct, but thinner, exines than that of terrestrial taxa. Pollen of the
amphibious taxa with internal geitonogamy had a thicker basal layer than species
without internal geitonogamy, whereas the overall exine was reduced in C.
hamulata and absent in C. brutia and C. lusitanica. Pollen of the obligately
submersed C. truncata also lacked an exine. These palynological data were
correlated with growth habits and related pollination biologies, as well as with
phylogenetic interpretations of Callitrichaceae. Exine reduction or loss has
evolved at least twice in the family, and it is associated with aneuploid
reduction in chromosome number.
PMID- 10675303
TI - SEM studies on vessels in ferns. 17. Psilotaceae.
AB - Perforation plates are reported in aerial and subaerial axes of Psilotum nudum
and in aerial axes of Tmesipteris obliqua. In Psilotum, both perforations lacking
pit membranes and perforations with pit membrane remnants were observed.
Perforation plates in Psilotum may consist wholly of one type or the other. In
Tmespteris, perforations have threadlike pit membranes or consist of porose pit
membranes. Wide perforations alternating with narrow pits, a conformation
observed in various ferns, were observed in Psilotum (subaerial axes). In
Psilotum, perforations are more common in metaxylem than in protoxylem;
perforations in protoxylem consist of primary wall areas containing small
circular porosities or relatively large circular to oval perforations. There are
no modifications in the secondary wall framework of protoxylem or metaxylem in
Psilotum or Tmesipteris that would permit one to distinguish presence of
perforations or perforation plates with light microscopy, and scanning electron
microscopy (SEM) is required for demonstration of porose walls or perforations.
The tracheary elements of the Psilotaceae studied have no features not also
observed in other ferns with SEM.
PMID- 10675304
TI - Execution of the auxin replacement apical dominance experiment in temperate woody
species.
AB - The classic Thimann-Skoog or auxin replacement apical dominance test of exogenous
auxin repression of lateral bud outgrowth was successfully executed in both
seedlings and older trees of white ash, green ash, and red oak under the
following conditions: (1) decapitation of a twig apex and auxin replacement were
carried out during spring flush, (2) the decapitation was in the previous
season's overwintered wood, and (3) the point of decapitation was below the upper
large irrepressible lateral buds but above the lower repressible lateral buds.
Although it has been suggested that neither auxin, the terminal bud, nor apical
dominance have control over the outgrowth of the irrepressible buds during spring
flush, there is evidence in the present study that indicates that such control
over the repressible buds exists. In seedlings, second-order branching, which
resulted from decapitation of elongating current shoots, was also inhibited by
exogenous auxin in the three species. Hence, the auxin replacement experiments
did work on year-old proleptic buds (of branches of older trees) that would have
entered the bud bank and also on current buds of seedlings. Cytokinin treatments
were ineffectual in promoting bud growth.
PMID- 10675305
TI - The absence of cryptic self-incompatibility in Clarkia unguiculata (Onagraceae).
AB - Many species exhibit reduced siring success of self-relative to outcross-pollen
donors. This can be attributed either to postfertilization abortion of selfed
ovules or to cryptic self-incompatibility (CSI). CSI is a form of self
incompatibility whereby the advantage to outcross pollen is expressed only
following pollinations where there is gametophytic competition between self and
outcross pollen. Under the definition of CSI, this differential success is due to
the superior prefertilization performance (pollen germination rate and pollen
tube growth rate) of outcross pollen relative to self pollen. Although CSI has
been demonstrated in several plant species, no studies have assessed among
population variation in the expression of CSI. We conducted a greenhouse study on
Clarkia unguiculata (an annual species with a mixed-mating system) to detect CSI,
and we compare our observations to previous reports of CSI in C. gracilis and
another population of C. unguiculata. In contrast to these previous studies of
CSI in Clarkia, we used genetic rather than phenotypic markers to measure the
relative performance of selfed vs. outcross pollen. In this study, we measured
the intensity of CSI in C. unguiculata from a large population in southern
California and we determined whether the magnitude of pollen competition
(manipulated by controlling the number of pollen grains deposited on a stigma)
influenced the outcome of competition between self and outcross pollen. In
contrast to previous investigations of Clarkia, we found no evidence for CSI. The
mean number of seeds sired per fruit did not differ between self and outcross
pollen following either single-donor or mixed pollinations. In addition, the
relative success of selfed vs. outcross pollen was independent of the magnitude
of pollen competition. These results suggest that: (1) one of the few
nonheterostylous species previously thought to be cryptically self-incompatible
is completely self-compatible (at least in the population studied here) or (2)
phenotypic markers may be problematic for the detection of CSI.
PMID- 10675306
TI - Dissecting the causes of variation in intra-inflorescence allocation in a
sexually polymorphic species, Fragaria virginiana (Rosaceae).
AB - In this study we dissect the causes of variation in intra-inflorescence
allocation in a sexually polymorphic species, Fragaria virginiana. We separated
out the effects of resource competition during flowering from those of
inflorescence architecture, as well as identified the effects of sex morph and
genotype. We found position-based variation in petal length, ovule, pollen, and
flower number to be influenced more by architecture than by our resource
manipulations during flowering. We also found both genotype- and sex-specific
intra-inflorescence patterns. Furthermore, our data indicate that the sex morph
specific intra-inflorescence patterns result from architectural modifications of
the basic pattern. In fact, sex-differential intra-inflorescence patterns suggest
that fitness through male and female function may be maximized by different
resource distribution patterns within the inflorescence and may have been
modified by past selection. Specifically, females invested heavily in ovules at
positions where fruit set was most likely (primary and secondary), at the expense
of flower number and allocation per flower at more distal positions. Whereas
functional males invested minimally in ovules at all flower positions and
produced the most abundantly flowered inflorescences, hermaphrodites, on the
other hand, showed intermediate patterns, implying a compromise between sex
functions. We suggest that consideration of intra-inflorescence allocation and
inflorescence architecture may reveal the mechanism underlying sexual dimorphism
in flower allocation and number.
PMID- 10675307
TI - Morphological variation and female reproductive success in two sympatric Trillium
species: evidence for phenotypic selection in Trillium erectum and Trillium
grandiflorum (Liliaceae).
AB - I investigated the mating systems and phenotypic variation of two sympatric
spring ephemerals, Trillium erectum and T. grandiflorum (Liliaceae), and
phenotypic selection acting through female reproductive success for 11
morphological characters in five sympatric populations of the two species. I
examined the degree of self-compatibility, pollinator-visitation rates, and
pollen limitation of fruit and seed production in both species. Both Trillium
species were self-compatible, but outcrossed flowers produced more successful
fruits and seeds than self-pollinated flowers. Pollinator-visitation rates to the
two species were low compared to other insect-pollinated spring ephemerals. In
addition, both T. erectum and T. grandiflorum experienced pollen limitation in
fruit and/or seed production; however, levels of fecundity in both species may be
influenced by resource availability as well. I found significant phenotypic
variation in 11 morphological characters within and among the five study
populations. The sizes of all morphological characters were positively
correlated. In general, larger T. erectum and T. grandiflorum produced more
seeds. Phenotypic selection analysis revealed that direct and indirect selection
acted on the size of morphological characters for both species. But there was no
detectable selection acting on plant shape. This study reveals that variation in
plant size exists within and among populations of both species, and this
variation is associated with variance in female reproductive success. Spatial and
temporal variation in pollinator and/or resource abundance may play a role in the
phenotypic variation exhibited by both Trillium species.
PMID- 10675308
TI - How accessible are receptive megastrobili to pollen? the example of jack pine
(Pinus banksiana).
AB - We examined the effects of wind speeds on pollen capture by megastrobili of jack
pine (Pinus banksiana). We found that, when wind speed increased from 1.3 to 7.5
m/s, the relative capture efficiency (E(r)) did not change significantly (P <=
0.206) and remained below 12%. However, total capture rates increased linearly
with wind speed and atmospheric pollen density. Because theoretical models of
capture efficiency predict the E(r) to increase to ~80% asymptotically, our
findings suggest that receptive megastrobili are equally adept at capturing
pollen at all naturally occurring wind speeds.
PMID- 10675309
TI - Biased sex ratios in the dioecious annual Croton texensis (Euphorbiaceae) are not
due to environmental sex determination.
AB - At Arapaho Prairie, in the sandhills of western Nebraska, the dioecious annual
Croton texensis (Euphorbiaceae) exhibits biased sex ratios. Moreover, the
direction of bias changes from year to year: in 1994 the study population was
significantly female biased, in 1995 and 1996 it was significantly male biased,
and in 1997 and 1998 the sex ratio did not differ from 1 : 1. Such variation in
the observed sex ratio in plants is frequently attributed to environmental sex
determination (ESD), which is favored by natural selection if the rate of fitness
gain across an environmental gradient is greater for one sex than the other. We
performed experiments to determine: (1) whether variation in the sex ratio is
correlated with environmental conditions, as would be expected if ESD is
operating, and (2) whether ESD, if present, would be favored by natural
selection. In a common garden experiment in which water and fertilizer were
manipulated the sex ratio was marginally male biased in treatments in which water
was added, but not different from 1 : 1 in other treatments. In field plots into
which seeds were planted none of several soil characteristics, nor overall plot
quality for C. texensis (measured as average plant biomass) were correlated with
plot sex ratio. However, plots in which a large number of planted seeds emerged
tended to be female biased. These results provide very weak evidence for sex
ratio bias across an environmental gradient, and thus provide little evidence for
ESD. Moreover, sex-by-environment interactions for fitness, which are required
for the evolution of ESD, were absent for all measured variables. Thus, ESD does
not appear to be favored by natural selection in this population. Instead, these
biases may have been caused by differences between the sexes in germination
and/or early mortality.
PMID- 10675310
TI - Patterns and determinants of potential carbon gain in the C3 evergreen Yucca
glauca (Liliaceae) in a C4 grassland.
AB - Yucca glauca is a C(3) evergreen rosette species locally common in the C(4)
dominated grasslands of the central Great Plains. Most congeners of Y. glauca are
found in deserts, and Y. glauca's morphological similarities to desert species
(steeply angled leaves, evergreen habit) may be critical to its success in
grasslands. We hypothesized that the evergreen habit of Y. glauca, coupled with
its ability to remain physiologically active at cool temperatures, would allow
this species to gain a substantial portion of its annual carbon budget when the
C(4) grasses are dormant. Leaf-level gas exchange was measured over an 18-mo
period at Konza Prairie in northeast Kansas to assess the annual pattern of
potential C gain. Two short-term experiments also were conducted in which
nighttime temperatures were manipulated to assess the cold tolerance of this
species. The annual pattern of C gain in Y. glauca was bimodal, with a spring
productive period (maximum monthly photosynthetic rate = 21.1 +/- 1.97 MUmol.m.s)
in March through June, a period of midseason photosynthetic depression, and a
fall productive period in October (15.6 +/- 1.25 MUmol.m.s). The steeply angled
leaves resulted in interception of photon flux density at levels above
photosynthetic saturation throughout the year. Reduced photosynthetic rates in
the summer may have been caused by low soil moisture, but temperature was
strongly related (r = 0.37) to annual variations in photosynthesis, with
nocturnal air temperatures below -5 degrees C in the late fall and early spring,
and high air temperatures (>32 degrees C) in the summer, limiting gas exchange.
Overall, 31% of the potential annual carbon gain in Y. glauca occurred outside
the "frost-free" period (April-October) at Konza Prairie and 43% occurred when
the dominant C(4) grasses were dormant. Future climates that include warmer
minimum temperatures in the spring and fall may enhance the success of Y. glauca
relative to the C(4) dominants in these grasslands.
PMID- 10675311
TI - Clonal growth of Lithospermum caroliniense (Boraginaceae) in contrasting sand
dune habitats.
AB - The occurrence of clonal growth of distylous Lithospermum caroliniense was
investigated in a population in the Nebraska Sandhills, an area where sand dunes
have been relatively stable for at least 1500-3000 yr, and compared to a
population occurring at the Indiana Dunes, an area of active sand dune formation.
Spatial autocorrelation analysis indicated the occurrence of significant clonal
propagation of genetically based floral morphs at Arapaho Prairie, but not for
the Indiana Dunes. Apparent clonal growth in the Sandhills population had no
overall negative effect on pollen deposition or fecundity relative to the Indiana
population, although in some large clones the proportion of compatible pollen
grains on stigmas was lower. Clonal growth may have occurred in the Sandhills
population because of the greater age and stability of the Nebraska Sandhills;
infrequent establishment of seedlings permits detection of clonal growth using
the spatial pattern of floral morphs. At the Indiana dunes, repeated cycles of
dune formation provide conditions favoring establishment of seedlings, and sand
dune succession results in disappearance of L. caroliniense before the
development of clones.
PMID- 10675312
TI - Interactive effects of elevated CO2 and temperature on water transport
inponderosa pine.
AB - Many studies report that water flux through trees declines in response to
elevated CO(2), but this response may be modified by exposure to increased
temperatures. To determine whether elevated CO(2) and temperature interact to
affect hydraulic conductivity, we grew ponderosa pine seedlings for 24 wk in
growth chambers with one of four atmospheric CO(2) concentrations (350, 550, 750,
and 1100 ppm) and either a low (15 degrees C nights, 25 degrees C days) or high
(20 degrees C nights, 30 degrees C days) temperature treatment. Vapor pressure
deficits were also higher in the elevated temperature treatment. Seedling biomass
increased with CO(2) concentration but was not affected by temperature. Root :
shoot ratio was unaffected by CO(2) and temperature. Leaf : sapwood area ratio
(A(L)/A(S)) declined in response to elevated temperature but was not influenced
by CO(2). Larger tracheid diameters at elevated temperature caused an increase in
xylem-specific hydraulic conductivity (K(S)). The increase in K(S) and decrease
in A(L)/A(S) led to higher leaf-specific hydraulic conductivity (K(L)) at
elevated temperature. Stomatal conductance (g(S)) was correlated with K(L) across
all treatments. Neither K(S), K(L), nor g(S) were affected by elevated CO(2)
concentrations. High K(L) in response to elevated temperature may support
increased transpiration or reduce the incidence of xylem cavitation in ponderosa
pine in future, warmer climates.
PMID- 10675313
TI - Genetic variation in chloroplast and nuclear ribosomal DNA in Utah juniper
(Juniperus osteosperma, Cupressaceae): evidence for interspecific gene flow.
AB - Geographic patterns of genetic variation in chlorolast (cpDNA) and nuclear
ribosomal (nrDNA) DNA were examined to test the hypothesis of hybridization
between Juniperus osteosperma and Juniperus occidentalis in the Great Basin of
western Nevada. Noncoding DNA from the trnL-trnF intergenic spacer and the trnL
intron of the chloroplast genome was sequenced from seven populations of J.
osteosperma and four populations of J. occidentalis sampled over a large
proportion of their respective ranges. An adenine nucleotide at position 436 in
the aligned sequence and within a Tru 9I restriction site was found to be present
in individuals of J. osteosperma sampled from western Colorado and central Utah,
but absent in sequences of J. osteosperma sampled from central and western Nevada
and all sequences of J. occidentalis. Two hundred fourteen individuals from 34
populations of J. osteosperma and J. occidentalis were then screened for cpDNA
haplotype by Tru 9I digestion of the trnL-trnF polymerase chain reaction (PCR)
product. Two cpDNA haplotypes were evident, each consisting of restriction
fragment profiles that differed solely with respect to the presence or absence of
the Tru 9I site encompassing the adenine nucleotide at position 436. One of these
haplotypes was monomorphic in J. occidentalis and exhibited a decreasing
frequency in J. osteosperma with increasing geographic distance from J.
occidentalis in west-central Nevada. Geographic patterns in nuclear ribosomal DNA
(nrDNA) variation were examined by restriction fragment analysis and, although
spatially more restricted, exhibited patterns of clinal variation similar to
those observed in cpDNA haplotype. Genetic relationships based on DNA sequences
and geographic patterns of genetic variation in chloroplast and nuclear ribosomal
DNA are consistent with morphology in suggesting interspecific gene flow between
J. occidentalis and J. osteosperma.
PMID- 10675314
TI - Phylogeny of South African Gnaphalieae (Asteraceae) based on two noncoding
chloroplast sequences.
AB - The Gnaphalieae are a group of sunflowers that have their greatest diversity in
South America, Southern Africa, and Australia. The objective of this study was to
reconstruct a phylogeny of the South African Gnaphalieae using sequence data from
two noncoding chloroplast DNA sequences, the trnL intron and trnL/trnF intergenic
spacer. Included in this investigation are the genera of the Gnaphalieae from the
African basal groups, members of the subtribes Cassiniinae, Gnaphaliinae, and
Relhaniinae, and African representatives from the large Old World genus
Helichrysum. Results indicate that two Gnaphaloid genera, Printzia and
Callilepis, should be excluded from the Gnaphalieae. In most trees the
Relhaniinae s.s. (sensu stricto) and some of the basal taxa comprise a clade that
is sister to the remainder of the tribe Gnaphalieae. The Relhaniinae, which are
restricted to Africa, are not a monophyletic group as presently circumscribed,
nor are the South African members of Helichrysum, the Cassiniinae and
Gnaphaliinae. There is general agreement between our molecular analysis and that
of morphology, particularly in the terminal branches of the trees.
PMID- 10675315
TI - A phylogeny of the flowering plant family Apiaceae based on chloroplast DNA rpl16
and rpoC1 intron sequences: towards a suprageneric classification of subfamily
Apioideae.
AB - The higher level relationships within Apiaceae (Umbelliferae) subfamily Apioideae
are controversial, with no widely acceptable modern classification available.
Comparative sequencing of the intron in chloroplast ribosomal protein gene rpl16
was carried out in order to examine evolutionary relationships among 119 species
(99 genera) of subfamily Apioideae and 28 species from Apiaceae subfamilies
Saniculoideae and Hydrocotyloideae, and putatively allied families Araliaceae and
Pittosporaceae. Phylogenetic analyses of these intron sequences alone, or in
conjunction with plastid rpoC1 intron sequences for a subset of the taxa, using
maximum parsimony and neighbor-joining methods, reveal a pattern of relationships
within Apioideae consistent with previously published chloroplast DNA and nuclear
ribosomal DNA ITS based phylogenies. Based on consensus of relationship, seven
major lineages within the subfamily are recognized at the tribal level. These are
referred to as tribes Heteromorpheae M. F. Watson & S. R. Downie Trib. Nov.,
Bupleureae Spreng. (1820), Oenantheae Dumort. (1827), Pleurospermeae M. F. Watson
& S. R. Downie Trib. Nov., Smyrnieae Spreng. (1820), Aciphylleae M. F. Watson &
S. R. Downie Trib. Nov., and Scandiceae Spreng. (1820). Scandiceae comprises
subtribes Daucinae Dumort. (1827), Scandicinae Tausch (1834), and Torilidinae
Dumort. (1827). Rpl16 intron sequences provide valuable characters for inferring
high-level relationships within Apiaceae but, like the rpoC1 intron, are
insufficient to resolve relationships among closely related taxa.
PMID- 10675316
TI - Protein phosphorylation and protein phosphatases. De Panne, Belgium, September 19
24, 1999.
PMID- 10675317
TI - Macromolecular mimicry.
AB - Some proteins have been shown to mimic the overall shape and structure of nucleic
acids. For some of the proteins involved in translating the genetic information
into proteins on the ribosome particle, there are indications that such
observations of macromolecular mimicry even extend to similarity in interaction
with and function on the ribosome. A small number of structural results obtained
outside the protein biosynthesis machinery could indicate that the concept of
macromolecular mimicry between proteins and nucleic acids is more general. The
implications for the function and evolution of protein biosynthesis are
discussed.
PMID- 10675318
TI - Multiple pathways control protein kinase C phosphorylation.
PMID- 10675319
TI - Crystal structure of human sex hormone-binding globulin: steroid transport by a
laminin G-like domain.
AB - Human sex hormone-binding globulin (SHBG) transports sex steroids in blood and
regulates their access to target tissues. In biological fluids, SHBG exists as a
homodimer and each monomer comprises two laminin G-like domains (G domains). The
crystal structure of the N-terminal G domain of SHBG in complex with 5alpha
dihydrotestosterone at 1.55 A resolution reveals both the architecture of the
steroid-binding site and the quaternary structure of the dimer. We also show that
G domains have jellyroll topology and are structurally related to pentraxin. In
each SHBG monomer, the steroid intercalates into a hydrophobic pocket within the
beta-sheet sandwich. The steroid and a 20 A distant calcium ion are not located
at the dimer interface. Instead, two separate steroid-binding pockets and calcium
binding sites exist per dimer. The structure displays intriguing disorder for
loop segment Pro130-Arg135. In all other jellyroll proteins, this loop is well
ordered. If modelled accordingly, it covers the steroid-binding site and could
thereby regulate access of ligands to the binding pocket.
PMID- 10675320
TI - B cells extract and present immobilized antigen: implications for affinity
discrimination.
AB - Binding of antigen to B-cell antigen receptor (BCR) leads to antigen
internalization and presentation to T cells, a critical process in the initiation
of the humoral immune response. However, antigen internalization has been
demonstrated for soluble antigen, in vivo antigen is often encountered in
insoluble form or tethered to a cell surface. Here, we show that not only can B
cells internalize and present large particulate antigen (requiring a signalling
competent BCR to drive antigen uptake), but they can also extract antigen that is
tethered tightly to a non-internalizable surface. The form in which the antigen
is displayed affects the B cell's ability to discriminate antigen-BCR affinity.
Thus, arraying an antigen on a particle or surface allows efficient presentation
of low affinity antigens. However, the presentation efficiency of antigen arrayed
on an internalizable particle plateaus at low affinity values. In contrast,
extraction and presentation of antigen from a non-internalizable surface depends
on antigen-BCR affinity over a wide affinity range. The results have implications
for understanding both the initiation and affinity maturation of the immune
response.
PMID- 10675321
TI - Activation of rho through a cross-link with polyamines catalyzed by Bordetella
dermonecrotizing toxin.
AB - The small GTPase Rho, which regulates a variety of cell functions, also serves as
a specific substrate for bacterial toxins. Here we demonstrate that Bordetella
dermonecrotizing toxin (DNT) catalyzes cross-linking of Rho with ubiquitous
polyamines such as putrescine, spermidine and spermine. Mass spectrometric
analyses revealed that the cross-link occurred at Gln63, which had been reported
to be deamidated by DNT in the absence of polyamines. Rac1 and Cdc42, other
members of the Rho family GTPases, were also polyaminated by DNT. The
polyamination, like the deamidation, markedly reduced the GTPase activity of Rho
without affecting its GTP-binding activity, indicating that polyaminated Rho
behaves as a constitutively active analog. Moreover, polyamine-linked Rho, even
in the GDP-bound form, associated more effectively with its effector ROCK than
deamidated Rho in the GTP-bound form and, when microinjected into cells, induced
the anomalous formation of stress fibers indistinguishable from those seen in DNT
treated cells. The results imply that the polyamine-linked Rho, transducing
signals to downstream ROCK in a novel GTP-independent manner, plays an important
role in DNT cell toxicity.
PMID- 10675322
TI - Anionic phospholipids are involved in membrane association of FtsY and stimulate
its GTPase activity.
AB - FtsY, the Escherichia coli homologue of the eukaryotic signal recognition
particle (SRP) receptor alpha-subunit, is located in both the cytoplasm and inner
membrane. It has been proposed that FtsY has a direct targeting function, but the
mechanism of its association with the membrane is unclear. FtsY is composed of
two hydrophilic domains: a highly charged N-terminal domain (the A-domain) and a
C-terminal GTP-binding domain (the NG-domain). FtsY does not contain any
hydrophobic sequence that might explain its affinity for the inner membrane, and
a membrane-anchoring protein has not been detected. In this study, we provide
evidence that FtsY interacts directly with E.coli phospholipids, with a
preference for anionic phospholipids. The interaction involves at least two lipid
binding sites, one of which is present in the NG-domain. Lipid association
induced a conformational change in FtsY and greatly enhanced its GTPase activity.
We propose that lipid binding of FtsY is important for the regulation of SRP
mediated protein targeting.
PMID- 10675323
TI - YidC, the Escherichia coli homologue of mitochondrial Oxa1p, is a component of
the Sec translocase.
AB - In Escherichia coli, both secretory and inner membrane proteins initially are
targeted to the core SecYEG inner membrane translocase. Previous work has also
identified the peripherally associated SecA protein as well as the SecD, SecF and
YajC inner membrane proteins as components of the translocase. Here, we use a
cross-linking approach to show that hydrophilic portions of a co-translationally
targeted inner membrane protein (FtsQ) are close to SecA and SecY, suggesting
that insertion takes place at the SecA/Y interface. The hydrophobic FtsQ signal
anchor sequence contacts both lipids and a novel 60 kDa translocase-associated
component that we identify as YidC. YidC is homologous to Saccharomyces
cerevisiae Oxa1p, which has been shown to function in a novel export pathway at
the mitochondrial inner membrane. We propose that YidC is involved in the
insertion of hydrophobic sequences into the lipid bilayer after initial
recognition by the SecAYEG translocase.
PMID- 10675324
TI - Degradation of unassembled Vph1p reveals novel aspects of the yeast ER quality
control system.
AB - The endoplasmic reticulum quality control (ERQC) system retains and degrades
soluble and membrane proteins that misfold or fail to assemble. Vph1p is the 100
kDa membrane subunit of the yeast Saccharomyces cerevisiae V-ATPase, which
together with other subunits, assembles into the V-ATPase in the ER, requiring
the ER resident protein Vma22p. In vma22Delta cells, Vph1p remains an integral
membrane protein with wild-type topology in the ER membrane before undergoing a
rapid and concerted degradation requiring neither vacuolar proteases nor
transport to the Golgi. Failure to assemble targets Vph1p for degradation in a
process involving ubiquitylation, the proteasome and cytosolic but not ER lumenal
chaperones. Vph1p appears to possess the traits of a 'classical' ERQC substrate,
yet novel characteristics are involved in its degradation: (i) UBC genes other
than UBC6 and UBC7 are involved and (ii) components of the ERQC system identified
to date (Der1p, Hrd1p/Der3p and Hrd3p) are not required. These data suggest that
other ERQC components must exist to effect the degradation of Vph1p, perhaps
comprising an alternative pathway.
PMID- 10675325
TI - A truncated isoform of the PP2A B56 subunit promotes cell motility through
paxillin phosphorylation.
AB - Both F10 and BL6 sublines of B16 mouse melanoma cells are metastatic after
intravenous injection, but only BL6 cells are metastatic after subcutaneous
injection. Retrotransposon insertion was found to produce an N-terminally
truncated form (Deltagamma1) of the B56gamma1 regulatory subunit isoform of
protein phosphatase (PP) 2A in BL6 cells, but not in F10 cells. We found an
interaction of paxillin with PP2A C and B56gamma subunits by co
immunoprecipitation. B56gamma1 co-localized with paxillin at focal adhesions,
suggesting a role for this isoform in targeting PP2A to paxillin. In this regard,
Deltagamma1 behaved similarly to B56gamma1. However, the Deltagamma1-containing
PP2A heterotrimer was insufficient for the dephosphorylation of paxillin.
Transfection with Deltagamma1 enhanced paxillin phosphorylation on serine
residues and recruitment into focal adhesions, and cell spreading with an actin
network. In addition, Deltagamma1 rendered F10 cells as highly metastatic as BL6
cells. These results suggest that mutations in PP2A regulatory subunits may cause
malignant progression.
PMID- 10675326
TI - Op18/stathmin caps a kinked protofilament-like tubulin tetramer.
AB - Oncoprotein 18/stathmin (Op18), a regulator of microtubule dynamics, was
recombinantly expressed and its structure and function analysed. We report that
Op18 by itself can fold into a flexible and extended alpha-helix, which is in
equilibrium with a less ordered structure. In complex with tubulin, however, all
except the last seven C-terminal residues of Op18 are tightly bound to tubulin.
Digital image analysis of Op18:tubulin electron micrographs revealed that the
complex consists of two longitudinally aligned alpha/beta-tubulin heterodimers.
The appearance of the complex was that of a kinked protofilament-like structure
with a flat and a ribbed side. Deletion mapping of Op18 further demonstrated that
(i) the function of the N-terminal part of the molecule is to 'cap' tubulin
subunits to ensure the specificity of the complex and (ii) the complete C
terminal alpha-helical domain of Op18 is necessary and sufficient for stable
Op18:tubulin complex formation. Together, our results suggest that besides
sequestering tubulin, the structural features of Op18 enable the protein
specifically to recognize microtubule ends to trigger catastrophes.
PMID- 10675327
TI - Crystal structure of a class I alpha1,2-mannosidase involved in N-glycan
processing and endoplasmic reticulum quality control.
AB - Mannose trimming is not only essential for N-glycan maturation in mammalian cells
but also triggers degradation of misfolded glycoproteins. The crystal structure
of the class I alpha1, 2-mannosidase that trims Man(9)GlcNAc(2) to Man(8)GlcNAc(2
)isomer B in the endoplasmic reticulum of Saccharomyces cerevisiae reveals a
novel (alphaalpha)(7)-barrel in which an N-glycan from one molecule extends into
the barrel of an adjacent molecule, interacting with the essential acidic
residues and calcium ion. The observed protein-carbohydrate interactions provide
the first insight into the catalytic mechanism and specificity of this eukaryotic
enzyme family and may be used to design inhibitors that prevent degradation of
misfolded glycoproteins in genetic diseases.
PMID- 10675328
TI - Induction of apoptosis by Drosophila reaper, hid and grim through inhibition of
IAP function.
AB - Induction of apoptosis in Drosophila requires the activity of three closely
linked genes, reaper, hid and grim. Here we show that the proteins encoded by
reaper, hid and grim activate cell death by inhibiting the anti-apoptotic
activity of the Drosophila IAP1 (diap1) protein. In a genetic modifier screen,
both loss-of-function and gain-of-function alleles in the endogenous diap1 gene
were obtained, and the mutant proteins were functionally and biochemically
characterized. Gain-of-function mutations in diap1 strongly suppressed reaper-,
hid- and grim-induced apoptosis. Sequence analysis of these alleles revealed that
they were caused by single amino acid changes in the baculovirus IAP repeat
domains of diap1, a domain implicated in binding REAPER, HID and GRIM.
Significantly, the corresponding mutant DIAP1 proteins displayed greatly reduced
binding of REAPER, HID and GRIM, indicating that REAPER, HID and GRIM kill by
forming a complex with DIAP1. These data provide strong in vivo evidence for a
previously published model of cell death regulation in Drosophila.
PMID- 10675329
TI - The Drosophila caspase DRONC is regulated by DIAP1.
AB - We have isolated the recently identified Drosophila caspase DRONC through its
interaction with the effector caspase drICE. Ectopic expression of DRONC induces
cell death in Schizosaccharomyces pombe, mammalian fibroblasts and the developing
Drosophila eye. The caspase inhibitor p35 fails to rescue DRONC-induced cell
death in vivo and is not cleaved by DRONC in vitro, making DRONC the first
identified p35-resistant caspase. The DRONC pro-domain interacts with Drosphila
inhibitor of apoptosis protein 1 (DIAP1), and co-expression of DIAP1 in the
developing Drosophila eye completely reverts the eye ablation phenotype induced
by pro-DRONC expression. In contrast, DIAP1 fails to rescue eye ablation induced
by DRONC lacking the pro-domain, indicating that interaction of DIAP1 with the
pro-domain of DRONC is required for suppression of DRONC-mediated cell death.
Heterozygosity at the diap1 locus enhances the pro-DRONC eye phenotype,
consistent with a role for endogenous DIAP1 in suppression of DRONC activation.
Both heterozygosity at the dronc locus and expression of dominant-negative DRONC
mutants suppress the eye phenotype caused by reaper (RPR) and head involution
defective (HID), consistent with the idea that DRONC functions in the RPR and HID
pathway.
PMID- 10675330
TI - C-cell hyperplasia, pheochromocytoma and sympathoadrenal malformation in a mouse
model of multiple endocrine neoplasia type 2B.
AB - Dominantly inherited multiple endocrine neoplasia type 2B (MEN2B) is
characterized by tumors of the thyroid C-cells and adrenal chromaffin cells,
together with ganglioneuromas of the gastrointestinal tract and other
developmental abnormalities. Most cases are caused by substitution of threonine
for Met918 in the RET receptor tyrosine kinase, which is believed to convert the
RET gene to an oncogene by altering the enzyme's substrate specificity. We report
the production of a mouse model of MEN2B by introduction of the corresponding
mutation into the ret gene. Mutant mice displayed C-cell hyperplasia and
chromaffin cell hyperplasia progressing to pheochromocytoma. Homozygotes did not
develop gastrointestinal ganglioneuromas, but displayed ganglioneuromas of the
adrenal medulla, enlargement of the associated sympathetic ganglia and a male
reproductive defect. Surprisingly, homozygotes did not display any developmental
defects attributable to a loss-of-function mutation. Thus, while our results
support the conclusion that the Met918Thr substitution is responsible for MEN2B,
they suggest that the substrate specificity of the RET kinase does not interfere
with its normal role in the development of the kidneys and enteric nervous
system.
PMID- 10675331
TI - An EGF receptor/Ral-GTPase signaling cascade regulates c-Src activity and
substrate specificity.
AB - c-Src is a membrane-associated tyrosine kinase that can be activated by many
types of extracellular signals, and can regulate the function of a variety of
cellular protein substrates. We demonstrate that epidermal growth factor (EGF)
and beta-adrenergic receptors activate c-Src by different mechanisms leading to
the phosphorylation of distinct sets of c-Src substrates. In particular, we found
that EGF receptors, but not beta(2)-adrenergic receptors, activated c-Src by a
Ral-GTPase-dependent mechanism. Also, c-Src activated by EGF treatment or
expression of constitutively activated Ral-GTPase led to tyrosine phosphorylation
of Stat3 and cortactin, but not Shc or subsequent Erk activation. In contrast, c
Src activated by isoproterenol led to tyrosine phosphorylation of Shc and
subsequent Erk activation, but not tyrosine phosphorylation of cortactin or
Stat3. These results identify a role for Ral-GTPases in the activation of c-Src
by EGF receptors and the coupling of EGF to transcription through Stat3 and the
actin cytoskeleton through cortactin. They also show that c-Src kinase activity
can be used differently by individual extracellular stimuli, possibly
contributing to their ability to generate unique cellular responses.
PMID- 10675332
TI - N-acyl homoserine lactone binding to the CarR receptor determines quorum-sensing
specificity in Erwinia.
AB - Quorum sensing via an N-acyl homoserine lactone (HSL) pheromone controls the
biosynthesis of a carbapenem antibiotic in Erwinia carotovora. Transcription of
the carbapenem biosynthetic genes is dependent on the LuxR-type activator
protein, CarR. Equilibrium binding of a range of HSL molecules, which are thought
to activate CarR to bind to its DNA target sequence, was examined using
fluorescence quenching, DNA bandshift analysis, limited proteolysis and reporter
gene assays. CarR bound the most physiologically relevant ligand, N-(3
oxohexanoyl)-L-homoserine lactone, with a stoichiometry of two molecules of
ligand per dimer of protein and a dissociation constant of 1.8 microM, in good
agreement with the concentration of HSL required to activate carbapenem
production in vivo. In the presence of HSL, CarR formed a very high molecular
weight complex with its target DNA, indicating that the ligand causes the protein
to multimerize. Chemical cross-linking analysis supported this interpretation.
Our data show that the ability of a given HSL to facilitate CarR binding to its
target DNA sequence is directly proportional to the affinity of the HSL for the
protein.
PMID- 10675333
TI - The Sos1 and Sos2 Ras-specific exchange factors: differences in placental
expression and signaling properties.
AB - Targeted disruption of both alleles of mouse sos1, which encodes a Ras-specific
exchange factor, conferred mid-gestational embryonic lethality that was secondary
to impaired placental development and was associated with very low placental ERK
activity. The trophoblastic layers of sos1(-/-) embryos were poorly developed,
correlating with high sos1 expression in wild-type trophoblasts. A sos1(-/-) cell
line, which expressed readily detectable levels of the closely related Sos2
protein, formed complexes between Sos2, epidermal growth factor receptor (EGFR)
and Shc efficiently, gave normal Ras.GTP and ERK responses when treated with EGF
for < or =10 min and was transformed readily by activated Ras. However, the sos1(
/-) cells were resistant to transformation by v-Src or by overexpressed EGFR and
continuous EGF treatment, unlike sos1(+/-) or wild-type cells. This correlated
with Sos2 binding less efficiently than Sos1 to EGFR and Shc in cells treated
with EGF for > or =90 min or to v-Src and Shc in v-Src-expressing cells, and with
less ERK activity. We conclude that Sos1 participates in both short- and long
term signaling, while Sos2-dependent signals are predominantly short-term.
PMID- 10675334
TI - Transcription factor Sp3 is essential for post-natal survival and late tooth
development.
AB - Sp3 is a ubiquitously expressed transcription factor closely related to Sp1
(specificity protein 1). We have disrupted the mouse Sp3 gene by homologous
recombination. Sp3-deficient embryos are growth retarded and invariably die at
birth of respiratory failure. The cause for the observed breathing defect remains
obscure since only minor morphological alterations were observed in the lung, and
surfactant protein expression is indistinguishable from that in wild-type mice.
Histological examinations of individual organs in Sp3(-/-) mice show a pronounced
defect in late tooth formation. In Sp3 null mice, the dentin/enamel layer of the
developing teeth is impaired due to the lack of ameloblast-specific gene
products. Comparison of the Sp1 and Sp3 knockout phenotype shows that Sp1 and Sp3
have distinct functions in vivo, but also suggests a degree of functional
redundancy.
PMID- 10675335
TI - Regulation of E2F1 activity by acetylation.
AB - During the G(1) phase of the cell cycle, an E2F-RB complex represses
transcription, via the recruitment of histone deacetylase activity.
Phosphorylation of RB at the G(1)/S boundary generates a pool of 'free' E2F,
which then stimulates transcription of S-phase genes. Given that E2F1 activity is
stimulated by p300/CBP acetylase and repressed by an RB-associated deacetylase,
we asked if E2F1 was subject to modification by acetylation. We show that the
p300/CBP-associated factor P/CAF, and to a lesser extent p300/CBP itself, can
acetylate E2F1 in vitro and that intracellular E2F1 is acetylated. The
acetylation sites lie adjacent to the E2F1 DNA-binding domain and involve lysine
residues highly conserved in E2F1, 2 and 3. Acetylation by P/CAF has three
functional consequences on E2F1 activity: increased DNA-binding ability,
activation potential and protein half-life. These results suggest that
acetylation stimulates the functions of the non-RB bound 'free' form of E2F1.
Consistent with this, we find that the RB-associated histone deacetylase can
deacetylate E2F1. These results identify acetylation as a novel regulatory
modification that stimulates E2F1's activation functions.
PMID- 10675336
TI - A single point mutation in TFIIA suppresses NC2 requirement in vivo.
AB - Negative cofactor 2 (NC2) is a dimeric histone-fold complex that represses RNA
polymerase II transcription through binding to TATA-box-binding protein (TBP) and
inhibition of the general transcription factors TFIIA and TFIIB. Here we study
molecular mechanisms of repression by human NC2 in vivo in yeast. Yeast NC2 genes
are essential and can be exchanged with human NC2. The physiologically relevant
regions of NC2 have been determined and shown to match the histone-fold
dimerization motif. A suppressor screen based upon limiting concentrations of
NC2beta yielded a cold-sensitive mutant in the yeast TFIIA subunit Toa1. The
single point mutation in Toa1 alleviates the requirement for both subunits of
NC2. Biochemical characterization indicated that mutant (mt)-Toa1 dimerizes well
with Toa2; it supports specific recognition of the TATA box by TBP but forms less
stable TBP-TFIIA-DNA complexes. Wild-type but not the mt-Toa1 can relieve NC2
effects in purified transcription systems. These data provide evidence for a
dimeric NC2 complex that is in an equilibrium with TFIIA after the initial
binding of TBP to promoter TATA boxes.
PMID- 10675337
TI - The novel coactivator C1 (HCF) coordinates multiprotein enhancer formation and
mediates transcription activation by GABP.
AB - Transcription of the herpes simplex virus 1 (HSV-1) immediate early (IE) genes is
determined by multiprotein enhancer complexes. The core enhancer assembly
requires the interactions of the POU-homeodomain protein Oct-1, the viral
transactivator alphaTIF and the cellular factor C1 (HCF). In this context, the C1
factor interacts with each protein to assemble the stable enhancer complex. In
addition, the IE enhancer cores contain adjacent binding sites for other cellular
transcription factors such as Sp1 and GA-binding protein (GABP). In this study, a
direct interaction of the C1 factor with GABP is demonstrated, defining the C1
factor as the critical coordinator of the enhancer complex assembly. In addition,
mutations that reduce the GABP transactivation potential also impair the C1-GABP
interaction, indicating that the C1 factor functions as a novel coactivator of
GABP-mediated transcription. The interaction and coordinated assembly of the
enhancer proteins by the C1 factor may be critical for the regulation of the HSV
lytic-latent cycle.
PMID- 10675338
TI - Activation of orphan receptor-mediated transcription by Ca(2+)/calmodulin
dependent protein kinase IV.
AB - Retinoid-related receptor alpha (RORalpha) is an orphan nuclear receptor that
constitutively activates transcription from its cognate response element. We show
that RORalpha is Ca(2+ )responsive, and a Ca(2+)/calmodulin-independent form of
Ca(2+)/calmodulin-dependent protein kinase IV (CaMKIV) potentiates RORalpha
dependent transcription 20- to 30-fold. Other orphan receptors including
RORalpha2, RORgamma and COUP-TFI are also potentiated by CaMKIV. Transcriptional
activation by CaMKIV is orphan receptor selective and does not occur with either
the thyroid hormone or estrogen receptor. CaMKIV does not phosphorylate RORalpha
or its ligand-binding domain (LBD) in vitro, although the LBD is essential for
transactivation. Therefore, the RORalpha LBD was used in the mammalian two-hybrid
assay to identify a single class of small peptide molecules containing LXXLL
motifs that interacted with greater affinity in the presence of CaMKIV. This
class of peptides antagonized activation of orphan receptor-mediated
transcription by CaMKIV. These studies demonstrate a pivotal role for CaMKIV in
the regulation of orphan receptor-mediated transcription.
PMID- 10675339
TI - Selective cell cycle transcription requires membrane synthesis in Caulobacter.
AB - Caulobacter crescentus divides asymmetrically and creates distinct polar membrane
surfaces that partition during the cell cycle to distinct cell progeny. Blocking
membrane synthesis prevented transcription from selective promoters involved in
asymmetric cell division. Transcription from sigma-54-dependent flagellar
promoters was blocked completely; however, transcription from the CtrA response
regulator-dependent flagellar promoters was activated but reduced. Transcription
from the ccrM (DNA methylation) promoter and the che (chemosensory) promoter was
also blocked completely. Transcription from a strong promoter at the chromosome
replication origin was first stopped then induced by blocked membrane synthesis.
We propose a feedback control coupling membrane synthesis to transcription that
selectively supports membrane-associated processes such as flagellar assembly,
chemosensory biogenesis and chromosome replication.
PMID- 10675340
TI - Compartmentalization of transcription and translation in Bacillus subtilis.
AB - Using fusions of green fluorescent protein to subunits of RNA polymerase (RNAP)
and ribosomes, we have investigated the subcellular localization of the
transcriptional and translational machinery in the bacterium Bacillus subtilis.
Unexpectedly, we found that RNAP resides principally within the nucleoid.
Conversely, ribosomes localized almost exclusively outside the nucleoid,
concentrating particularly towards sites of cell division. This zonal
localization was not dependent on cell division and is probably due, at least in
part, to exclusion from the nucleoid. Dual labelling of RNAP and ribosomes was
used to confirm the spatial separation of the two processes. We conclude that,
even in the absence of a nuclear membrane, transcription and translation occur
predominantly in separate functional domains. At higher growth rates,
concentrations of RNAP developed, probably representing the sites of rRNA
synthesis. These may represent a further spatial specialization, possibly
equivalent to the eukaryotic nucleolus.
PMID- 10675341
TI - On how a transcription factor can avoid its proteolytic activation in the absence
of signal transduction.
AB - In response to alkaline ambient pH, the Aspergillus nidulans PacC transcription
factor mediating pH regulation of gene expression is activated by proteolytic
removal of a negative-acting C-terminal domain. We demonstrate interactions
involving the approximately 150 C-terminal PacC residues and two regions located
immediately downstream of the DNA binding domain. Our data indicate two full
length PacC conformations whose relative amounts depend upon ambient pH: one
'open' and accessible for processing, the other 'closed' and inaccessible. The
location of essential determinants for proteolytic processing within the two more
upstream interacting regions probably explains why the interactions prevent
processing, whereas the direct involvement of the C-terminal region in processing
preventing interactions explains why C-terminal truncating mutations result in
alkalinity mimicry and pH-independent processing. A mutant PacC deficient in pH
signal response and consequent processing behaves as though locked in the
'closed' form. Single-residue substitutions, obtained as mutations bypassing the
need for pH signal transduction, identify crucial residues in each of the three
interactive regions and overcome the processing deficiency in the 'permanently
closed' mutant.
PMID- 10675342
TI - Hepatitis C virus core protein-induced loss of LZIP function correlates with
cellular transformation.
AB - Hepatitis C virus (HCV) is the major etiological agent of blood-borne non-A non-B
hepatitis and a leading cause of liver cirrhosis and hepatocellular carcinoma
worldwide. HCV core protein is a multifunctional protein with regulatory
functions in cellular transcription and virus-induced transformation and
pathogenesis. Here we report on the identification of a bZIP nuclear
transcription protein as an HCV core cofactor for transformation. This bZIP
factor, designated LZIP, activates CRE-dependent transcription and regulates cell
proliferation. Loss of LZIP function in NIH 3T3 cells triggers morphological
transformation and anchorage-independent growth. We show that HCV core protein
aberrantly sequesters LZIP in the cytoplasm, inactivates LZIP function and
potentiates cellular transformation. Our findings suggest that LZIP might serve a
novel cellular tumor suppressor function that is targeted by the HCV core.
PMID- 10675343
TI - Hsp15: a ribosome-associated heat shock protein.
AB - We are analyzing highly conserved heat shock genes of unknown or unclear function
with the aim of determining their cellular role. Hsp15 has previously been shown
to be an abundant nucleic acid-binding protein whose synthesis is induced
massively at the RNA level upon temperature upshift. We have now identified that
the in vivo target of Hsp15 action is the free 50S ribosomal subunit. Hsp15 binds
with very high affinity (K(D) <5 nM) to this subunit, but only when 50S is free,
not when it is part of the 70S ribosome. In addition, the binding of Hsp15
appears to correlate with a specific state of the mature, free 50S subunit, which
contains bound nascent chain. This provides the first evidence for a so far
unrecognized abortive event in translation. Hsp15 is suggested to be involved in
the recycling of free 50S subunits that still carry a nascent chain. This gives
Hsp15 a very different functional role from all other heat shock proteins and
points to a new aspect of translation.
PMID- 10675344
TI - Structure of Hsp15 reveals a novel RNA-binding motif.
AB - We have solved the crystal structure of the heat shock protein Hsp15, a newly
isolated and very highly inducible heat shock protein that binds the ribosome.
Comparison of its structure with those of two RNA-binding proteins, ribosomal
protein S4 and threonyl-tRNA synthetase, reveals a novel RNA-binding motif. This
newly recognized motif is remarkably common, present in at least eight different
protein families that bind RNA. The motif's surface is populated by conserved,
charged residues that define a likely RNA-binding site. An intriguing pattern
emerges: stress proteins, ribosomal proteins and tRNA synthetases repeatedly
share a conserved motif. This may imply a hitherto unrecognized functional
similarity between these three protein classes.
PMID- 10675345
TI - DNA bending and a flip-out mechanism for base excision by the helix-hairpin-helix
DNA glycosylase, Escherichia coli AlkA.
AB - The Escherichia coli AlkA protein is a base excision repair glycosylase that
removes a variety of alkylated bases from DNA. The 2.5 A crystal structure of
AlkA complexed to DNA shows a large distortion in the bound DNA. The enzyme flips
a 1-azaribose abasic nucleotide out of DNA and induces a 66 degrees bend in the
DNA with a marked widening of the minor groove. The position of the 1-azaribose
in the enzyme active site suggests an S(N)1-type mechanism for the glycosylase
reaction, in which the essential catalytic Asp238 provides direct assistance for
base removal. Catalytic selectivity might result from the enhanced stacking of
positively charged, alkylated bases against the aromatic side chain of Trp272 in
conjunction with the relative ease of cleaving the weakened glycosylic bond of
these modified nucleotides. The structure of the AlkA-DNA complex offers the
first glimpse of a helix-hairpin-helix (HhH) glycosylase complexed to DNA.
Modeling studies suggest that other HhH glycosylases can bind to DNA in a similar
manner.
PMID- 10675346
TI - The numbers of individual mitochondrial DNA molecules and mitochondrial DNA
nucleoids in yeast are co-regulated by the general amino acid control pathway.
AB - Mitochondrial DNA (mtDNA) is inherited as a protein-DNA complex (the nucleoid).
We show that activation of the general amino acid response pathway in rho(+) and
rho(-) petite cells results in an increased number of nucleoids without an
increase in mtDNA copy number. In rho(-) cells, activation of the general amino
acid response pathway results in increased intramolecular recombination between
tandemly repeated sequences of rho(-) mtDNA to produce small, circular oligomers
that are packaged into individual nucleoids, resulting in an approximately 10
fold increase in nucleoid number. The parsing of mtDNA into nucleoids due to
general amino acid control requires Ilv5p, a mitochondrial protein that also
functions in branched chain amino acid biosynthesis, and one or more factors
required for mtDNA recombination. Two additional proteins known to function in
mtDNA recombination, Abf2p and Mgt1p, are also required for parsing mtDNA into a
larger number of nucleoids, although expression of these proteins is not under
general amino acid control. Increased nucleoid number leads to increased mtDNA
transmission, suggesting a mechanism to enhance mtDNA inheritance under amino
acid starvation conditions.
PMID- 10675347
TI - Tn10 transpososome assembly involves a folded intermediate that must be unfolded
for target capture and strand transfer.
AB - Tn10 transposition, like all transposition reactions examined thus far, involves
assembly of a stable protein-DNA transpososome, containing a pair of transposon
ends, within which all chemical events occur. We report here that stable Tn10 pre
cleavage transpososomes occur in two conformations: a folded form which contains
the DNA-bending factor IHF and an unfolded form which lacks IHF. Functional
analysis shows that both forms undergo double strand cleavage at the transposon
ends but that only the unfolded form is competent for target capture (and thus
for strand transfer to target DNA). Additional studies reveal that formation of
any type of stable transpososome, folded or unfolded, requires not only IHF but
also non-specific transposase-DNA contacts immediately internal to the IHF
binding site, implying the occurrence of a topo- logically closed loop at the
transposon end. Overall, transpososome assembly must proceed via a folded
intermediate which, however, must be unfolded in order for intermolecular
transposition to occur. These and other results support key features of a
recently proposed model for transpososome assembly and morphogenesis.
PMID- 10675348
TI - Epigenetics and its role in disease.
PMID- 10675349
TI - Beckwith-Wiedemann syndrome: imprinting in clusters revisited.
PMID- 10675350
TI - NF-kappaB determines localization and features of cell death in epidermis.
AB - Specialized forms of physiologic cell death lacking certain characteristic
morphologic features of apoptosis occur in terminally differentiating tissues,
such as in the outer cell layers of epidermis. In these cell layers, NF-kappaB
translocates from the cytoplasm to the nucleus and induces target gene
expression. In light of its potent role in regulating apoptotic cell death in
other tissues, NF-kappaB activation in these cells suggests that this
transcription factor regulates cell death during terminal differentiation. Here,
we show that NF-kappaB protects normal epithelial cells from apoptosis induced by
both TNFalpha and Fas, whereas NF-kappaB blockade enhances susceptibility to
death via both pathways. Expression of IkappaBalphaM under control of keratin
promoter in transgenic mice caused a blockade of NF-kappaB function in the
epidermis and provoked premature spontaneous cell death with apoptotic features.
In normal tissue, expression of the known NF-kappaB-regulated antiapoptotic
factors, TRAF1, TRAF2, c-IAP1, and c-IAP2, is most pronounced in outer epidermis.
In transgenic mice, NF-kappaB blockade suppressed this expression, whereas NF
kappaB activation augmented it, consistent with regulation of cell death by these
NF-kappaB effector proteins. These data identify a new role for NF-kappaB in
preventing premature apoptosis in cells committed to undergoing physiologic cell
death and indicate that, in stratified epithelium, such cell death normally
proceeds via a distinct pathway that is resistant to NF-kappaB and its
antiapoptotic target effector genes.
PMID- 10675351
TI - The basic helix-loop-helix transcription factor, dHAND, is required for vascular
development.
AB - Reciprocal interactions between vascular endothelial cells and vascular
mesenchymal cells are essential for angiogenesis. Here we show that the basic
helix-loop-helix transcription factor, dHAND/Hand2, is expressed in the
developing vascular mesenchyme and its derivative, vascular smooth muscle cells
(VSMCs). Targeted deletion of the dHAND gene in mice revealed severe defects of
embryonic and yolk sac vascular development by embryonic day 9.5. Vascular
endothelial cells expressed most markers of differentiation. Vascular mesenchymal
cells migrated appropriately but failed to make contact with vascular endothelial
cells and did not differentiate into VSMCs. In a screen for genes whose
expression was dependent upon dHAND (using subtractive hybridization comparing
wild-type and dHAND-null hearts), the VEGF(165) receptor, neuropilin-1, was found
to be downregulated in dHAND mutants. These results suggest that dHAND is
required for vascular development and regulates angiogenesis, possibly through a
VEGF signaling pathway.
PMID- 10675352
TI - Surgical implantation of adipose tissue reverses diabetes in lipoatrophic mice.
AB - In lipoatrophic diabetes, a lack of fat is associated with insulin resistance and
hyperglycemia. This is in striking contrast to the usual association of diabetes
with obesity. To understand the underlying mechanisms, we transplanted adipose
tissue into A-ZIP/F-1 mice, which have a severe form of lipoatrophic diabetes.
Transplantation of wild-type fat reversed the hyperglycemia, dramatically lowered
insulin levels, and improved muscle insulin sensitivity, demonstrating that the
diabetes in A-ZIP/F-1 mice is caused by the lack of adipose tissue. All aspects
of the A-ZIP/F-1 phenotype including hyperphagia, hepatic steatosis, and
somatomegaly were either partially or completely reversed. However, the
improvement in triglyceride and FFA levels was modest. Donor fat taken from
parametrial and subcutaneous sites was equally effective in reversing the
phenotype. The beneficial effects of transplantation were dose dependent and
required near-physiological amounts of transplanted fat. Transplantation of
genetically modified fat into A-ZIP/F-1 mice is a new and powerful technique for
studying adipose physiology and the metabolic and endocrine communication between
adipose tissue and the rest of the body.
PMID- 10675353
TI - Multidrug resistance protein 1 protects the choroid plexus epithelium and
contributes to the blood-cerebrospinal fluid barrier.
AB - Multidrug resistance protein 1 (MRP1) is a transporter protein that helps to
protect normal cells and tumor cells against the influx of certain xenobiotics.
We previously showed that Mrp1 protects against cytotoxic drugs at the testis
blood barrier, the oral epithelium, and the kidney urinary collecting duct
tubules. Here, we generated Mrp1/Mdr1a/Mdr1b triple-knockout (TKO) mice, and used
them together with Mdr1a/Mdr1b double-knockout (DKO) mice to study the
contribution of Mrp1 to the tissue distribution and pharmacokinetics of
etoposide. We observed increased toxicity in the TKO mice, which accumulated
etoposide in brown adipose tissue, colon, salivary gland, heart, and the female
urogenital system. Immunohistochemical staining revealed the presence of Mrp1 in
the oviduct, uterus, salivary gland, and choroid plexus (CP) epithelium. To
explore the transport function of Mrp1 in the CP epithelium, we used TKO and DKO
mice cannulated for cerebrospinal fluid (CSF). We show here that the lack of Mrp1
protein causes etoposide levels to increase about 10-fold in the CSF after
intravenous administration of the drug. Our results indicate that Mrp1 helps to
limit tissue distribution of certain drugs and contributes to the blood-CSF drug
permeability barrier.
PMID- 10675354
TI - Improved insulin-sensitivity in mice heterozygous for PPAR-gamma deficiency.
AB - The thiazolidinedione class of insulin-sensitizing, antidiabetic drugs interacts
with peroxisome proliferator-activated receptor gamma (PPAR-gamma). To gain
insight into the role of this nuclear receptor in insulin resistance and
diabetes, we conducted metabolic studies in the PPAR-gamma gene knockout mouse
model. Because homozygous PPAR-gamma-null mice die in development, we studied
glucose metabolism in mice heterozygous for the mutation (PPAR-gamma(+/-) mice).
We identified no statistically significant differences in body weight, basal
glucose, insulin, or FFA levels between the wild-type (WT) and PPAR-gamma(+/-)
groups. Nor was there a difference in glucose excursion between the groups of
mice during oral glucose tolerance test, but insulin concentrations of the WT
group were greater than those of the PPAR-gamma(+/-) group, and insulin-induced
increase in glucose disposal rate was significantly increased in PPAR-gamma(+/-)
mice. Likewise, the insulin-induced suppression of hepatic glucose production was
significantly greater in the PPAR-gamma(+/-) mice than in the WT mice. Taken
together, these results indicate that - counterintuitively - although
pharmacological activation of PPAR-gamma improves insulin sensitivity, a similar
effect is obtained by genetically reducing the expression levels of the receptor.
PMID- 10675355
TI - Decreased neointimal formation in Mac-1(-/-) mice reveals a role for inflammation
in vascular repair after angioplasty.
AB - Inflammation plays an essential role in the initiation and progression of
atherosclerosis, but its role in vascular repair after mechanical arterial injury
(i.e., percutaneous transluminal coronary angioplasty, PTCA) is unknown. In
animal models of vascular injury, leukocytes are recruited as a precursor to
intimal thickening. Furthermore, markers of leukocyte activation - in particular,
increased expression of the beta2-integrin Mac-1 (alphaMbeta2, or CD11b/CD18),
which is responsible for firm leukocyte adhesion to platelets and fibrinogen on
denuded vessels - predict restenosis after PTCA. To determine whether Mac-1
mediated leukocyte recruitment is causally related to neointimal formation, we
subjected mice lacking Mac-1 to a novel form of mechanical carotid artery
dilation and complete endothelial denudation. We now report that the selective
absence of Mac-1 impairs transplatelet leukocyte migration into the vessel wall,
reducing leukocyte accumulation over time. Diminished medial leukocyte
accumulation was accompanied by markedly reduced neointimal thickening after
vascular injury. These data establish a role for inflammation in neointimal
thickening and suggest that leukocyte recruitment to mechanically injured
arteries may prevent restenosis.
PMID- 10675356
TI - Differential immune responses to alpha-gal epitopes on xenografts and allografts:
implications for accommodation in xenotransplantation.
AB - Xenograft recipients produce large amounts of high-affinity anti-Gal IgG in
response to Galalpha1-3Galbeta1- 4GlcNAc-R (alpha-gal) epitopes on the graft. In
contrast, ABO-mismatched allograft recipients undergo "accommodation," a state of
very weak immune response to ABO antigens. These differences in anti-carbohydrate
immune response were studied in alpha1,3galactosyltransferase knock-out mice. Pig
kidney membranes administered to these mice elicited extensive production of anti
Gal IgG, whereas allogeneic kidney membranes expressing alpha-gal epitopes
elicited only a weak anti-Gal IgM response. Anti-Gal IgG response to xenograft
membranes depended on helper T cell activation and was inhibited by anti-CD40L
antibody. These T cells were activated by xenopeptides and not by alpha-gal
epitopes. Moreover, allogeneic cell membranes manipulated to express xenoproteins
also induced anti-Gal IgG response. Xenoglycoproteins with alpha-gal epitopes are
processed by anti-Gal B cells. Xenopeptides presented by these cells activate a
large repertoire of helper T cells required for the differentiation of anti-Gal B
cells into cells secreting anti-Gal IgG. Alloglycoproteins with alpha- gal
epitopes have very few immunogenic peptides and fail to activate helper T cells.
Similarly, ineffective helper T-cell activation prevents a strong immune response
to blood group antigens in ABO-mismatched allograft recipients, thus enabling the
development of accommodation.
PMID- 10675357
TI - Insulin resistance differentially affects the PI 3-kinase- and MAP kinase
mediated signaling in human muscle.
AB - The broad nature of insulin resistant glucose metabolism in skeletal muscle of
patients with type 2 diabetes suggests a defect in the proximal part of the
insulin signaling network. We sought to identify the pathways compromised in
insulin resistance and to test the effect of moderate exercise on whole-body and
cellular insulin action. We conducted euglycemic clamps and muscle biopsies on
type 2 diabetic patients, obese nondiabetics and lean controls, with and without
a single bout of exercise. Insulin stimulation of the phosphatidylinositol 3
kinase (PI 3-kinase) pathway, as measured by phosphorylation of the insulin
receptor and IRS-1 and by IRS protein association with p85 and with PI 3-kinase,
was dramatically reduced in obese nondiabetics and virtually absent in type 2
diabetic patients. Insulin stimulation of the MAP kinase pathway was normal in
obese and diabetic subjects. Insulin stimulation of glucose-disposal correlated
with association of p85 with IRS-1. Exercise 24 hours before the euglycemic clamp
increased phosphorylation of insulin receptor and IRS-1 in obese and diabetic
subjects but did not increase glucose uptake or PI 3-kinase association with IRS
1 upon insulin stimulation. Thus, insulin resistance differentially affects the
PI 3-kinase and MAP kinase signaling pathways, and insulin-stimulated IRS-1
association with PI 3-kinase defines a key step in insulin resistance.
PMID- 10675358
TI - A novel mutation in DAX1 causes delayed-onset adrenal insufficiency and
incomplete hypogonadotropic hypogonadism.
AB - Mutations in the DAX1 gene cause X-linked adrenal hypoplasia congenita (AHC) and
hypogonadotropic hypogonadism (HHG). In affected boys, primary adrenal
insufficiency occurs soon after birth or during early childhood; HHG is
recognized at the expected time of puberty. In this report, we describe the novel
phenotype of a man who presented with apparently isolated adrenal insufficiency
at 28 years of age. Examination revealed partial pubertal development and
undiagnosed incomplete HHG. Gonadotropin therapy did not improve his marked
oligospermia, suggesting a concomitant primary testicular abnormality. Genomic
analysis revealed a novel missense mutation, I439S, in DAX1. The mutant DAX-1
protein was studied for its ability to function as a transcriptional repressor of
target genes. Consistent with the patient's mild clinical phenotype, the I439S
mutation conferred intermediate levels of repressor activity of DAX-1 when
compared with mutations associated with classic AHC. This unique case extends the
clinical spectrum of AHC to include delayed-onset primary adrenal insufficiency
in adulthood and milder forms of HHG. Furthermore, in accordance with findings in
Ahch (Dax1) knockout mice, the clinical features in this patient suggest that DAX
1 function is required for spermatogenesis in humans, independent of its known
effects on gonadotropin production.
PMID- 10675359
TI - Colchicine protects mice from the lethal effect of an agonistic anti-Fas
antibody.
AB - The aim of this study was to determine whether colchicine, which has been
reported to protect against various hepatotoxic insults, influences the
susceptibility of mice to the agonistic anti-Fas antibody, Jo2. All mice that
were pretreated with colchicine (2 mg/kg) survived the lethal challenge of
intraperitoneal administration of 10 microg of Jo2, whereas all control mice
pretreated with gamma-lumicolchicine succumbed to the challenge. Twelve
micrograms of Jo2 killed less than half of colchicine-pretreated mice and its
lethal effects were delayed relative to control mice, which all died within 8
hours. Other microtubule-disrupting agents such as Taxol, vinblastine, and
nocodazole also improved the survival of mice treated with the lethal dose of
Jo2. Histologic examination showed that colchicine protected against Jo2-induced
fulminant liver injury, and TUNEL assay demonstrated that colchicine protected
against massive apoptosis of hepatocytes. Hepatocytes isolated from colchicine
pretreated mice exhibited decreased susceptibility to Jo2-induced apoptosis. In
addition, colchicine pretreatment reduced surface expression of Fas and decreased
Jo2- and TNF-alpha-induced apoptosis of cultured hepatocytes in the presence of
actinomycin D, but did not affect the susceptibility of cultured sinusoidal
endothelial cells to Jo2-induced apoptosis. Remarkably, Fas and TNF receptor-1
mRNA and intracellular protein levels increased after colchicine treatment,
indicating that colchicine protects against death ligand-induced apoptosis in the
liver by decreasing death-receptor targeting to the cell surface.
PMID- 10675360
TI - Heparin-binding EGF-like growth factor contributes to reduced glomerular
filtration rate during glomerulonephritis in rats.
AB - Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of
the epidermal growth factor (EGF) family, is expressed during inflammatory and
pathological conditions. We have cloned the rat HB-EGF and followed the
expression of HB-EGF in rat kidneys treated with anti- glomerular basement
membrane (anti-GBM) antibody (Ab) to induce glomerulonephritis (GN). We observed
glomerular HB-EGF mRNA and protein within 30 minutes of Ab administration and
showed by in situ hybridization that glomerular HB-EGF mRNA expression was
predominantly in mesangial and epithelial cells. Expression of HB-EGF correlated
with the onset of decreased renal function in this model. To test the direct
effect of HB-EGF on renal function, we infused the renal cortex with active rHB
EGF, prepared from transfected Drosophila melanogaster cells. This treatment
induced a significant decrease in single nephron GFR (SNGFR), single nephron
plasma flow, and glomerular ultrafiltration coefficient and an increase in the
glomerular capillary hydrostatic pressure gradient. In addition, anti-HB-EGF Ab
administered just before anti-GBM Ab blocked the fall in SNGFR and GFR at 90
minutes without any change in the glomerular histologic response. These studies
suggest that HB-EGF expressed early in the anti-GBM Ab GN model contributes to
the observed acute glomerular hemodynamic alterations.
PMID- 10675361
TI - Diazepam-binding inhibitor mediates feedback regulation of pancreatic secretion
and postprandial release of cholecystokinin.
AB - Recently, we isolated a trypsin-sensitive cholecystokinin-releasing peptide (CCK
RP) from porcine and rat intestinal mucosa. The amino acid sequence of this
peptide was determined to be identical to that of the diazepam-binding inhibitor
(DBI). To test the role of DBI in pancreatic secretion and responses to feeding,
we used pancreaticobiliary and intestinal cannula to divert bile-pancreatic juice
from anesthetized rats. Within 2 hours, this treatment caused a 2-fold increase
in pancreatic protein output and a >10-fold increase in plasma CCK. Luminal DBI
levels increased 4-fold. At 5 hours after diversion of bile-pancreatic juice,
each of these measures returned to basal levels. Intraduodenal infusion of
peptone evoked a 5-fold increase in the concentration of luminal DBI. In separate
studies, we demonstrated that intraduodenal administration of antiserum to a DBI
peptide specifically abolished pancreatic secretion and the increase in plasma
CCK levels after diversion of bile-pancreatic juice. To demonstrate that DBI
mediates the postprandial rise in plasma CCK levels, we showed that intraduodenal
administration of 5% peptone induced dramatic increases in pancreatic secretion
and plasma CCK, effects that could be blocked by intraduodenal administration of
anti-DBI antiserum. Hence, DBI, a trypsin-sensitive CCK-RP secreted from the
proximal small bowel, mediates the feedback regulation of pancreatic secretion
and the postprandial release of CCK.
PMID- 10675362
TI - Adenosine and inosine increase cutaneous vasopermeability by activating A(3)
receptors on mast cells.
AB - Adenosine has potent effects on both the cardiovascular and immune systems.
Exposure of tissues to adenosine results in increased vascular permeability and
extravasation of serum proteins. The mechanism by which adenosine brings about
these physiological changes is poorly defined. Using mice deficient in the A(3)
adenosine receptor (A(3)AR), we show that increases in cutaneous vascular
permeability observed after treatment with adenosine or its principal metabolite
inosine are mediated through the A(3)AR. Adenosine fails to increase vascular
permeability in mast cell-deficient mice, suggesting that this tissue response to
adenosine is mast cell-dependent. Furthermore, this response is independent of
activation of the high-affinity IgE receptor (FcepsilonR1) by antigen, as
adenosine is equally effective in mediating these changes in FcepsilonR1 beta
chain-deficient mice. Together these results support a model in which adenosine
and inosine induce changes in vascular permeability indirectly by activating mast
cells, which in turn release vasoactive substances. The demonstration in vivo
that adenosine, acting through a specific receptor, can provoke degranulation of
this important tissue-based effector cell, independent of antigen activation of
the high-affinity IgE receptor, supports an important role for this nucleoside in
modifying the inflammatory response.
PMID- 10675363
TI - C-reactive protein binding to FcgammaRIIa on human monocytes and neutrophils is
allele-specific.
AB - C-reactive protein (CRP) is involved in host defense, regulation of inflammation,
and modulation of autoimmune disease. Although the presence of receptors for CRP
on phagocytes has been inferred for years, their identity was determined only
recently. FcgammaRIa, the high-affinity IgG receptor, binds CRP with low
affinity, whereas FcgammaRIIa, the low-affinity IgG receptor, binds CRP with high
affinity. Because the single nucleotide polymorphism in FcgammaRIIA - which
encodes histidine or arginine at position 131 - strongly influences IgG2 binding,
we determined this polymorphism's effect on CRP binding. CRP bound with high
avidity to monocytes and neutrophils from FcgammaRIIA R-131 homozygotes, and
binding was inhibited by the R-specific mAb 41H16. CRP showed decreased binding
to cells from FcgammaRIIA H-131 homozygotes (which bind IgG2 with high affinity).
However, IFN-gamma enhanced FcgammaRI expression by H-131 monocytes and increased
CRP binding. FcgammaRIIa heterozygotes showed intermediate binding. CRP initiated
increases in [Ca(2+)](i) in PMN from R-131, but not from H-131 homozygotes. These
data provide direct genetic evidence for FcgammaRIIa as the functional, high
affinity CRP receptor on leukocytes while emphasizing the reciprocal relationship
between IgG and CRP binding avidities. This counterbalance may affect the
contribution of FcgammaRIIA alleles to host defense and autoimmunity.
PMID- 10675364
TI - Syntaxin 1A is expressed in airway epithelial cells, where it modulates CFTR Cl(
) currents.
AB - The CFTR Cl(-) channel controls salt and water transport across epithelial
tissues. Previously, we showed that CFTR-mediated Cl(-) currents in the Xenopus
oocyte expression system are inhibited by syntaxin 1A, a component of the
membrane trafficking machinery. This negative modulation of CFTR function can be
reversed by soluble syntaxin 1A peptides and by the syntaxin 1A binding protein,
Munc-18. In the present study, we determined whether syntaxin 1A is expressed in
native epithelial tissues that normally express CFTR and whether it modulates
CFTR currents in these tissues. Using immunoblotting and immunofluorescence, we
observed syntaxin 1A in native gut and airway epithelial tissues and showed that
epithelial cells from these tissues express syntaxin 1A at >10-fold molar excess
over CFTR. Syntaxin 1A is seen near the apical cell surfaces of human bronchial
airway epithelium. Reagents that disrupt the CFTR-syntaxin 1A interaction,
including soluble syntaxin 1A cytosolic domain and recombinant Munc-18, augmented
cAMP-dependent CFTR Cl(-) currents by more than 2- to 4-fold in mouse tracheal
epithelial cells and cells derived from human nasal polyps, but these reagents
did not affect CaMK II-activated Cl(-) currents in these cells.
PMID- 10675366
TI - MEMORANDUM FOR: science writers and editors on the journal press list : genetic
similarity found between ductal carcinomas In situ and their recurrences
PMID- 10675365
TI - RXRalpha overexpression in cardiomyocytes causes dilated cardiomyopathy but fails
to rescue myocardial hypoplasia in RXRalpha-null fetuses.
AB - Retinoid X receptor alpha-null (RXRalpha-null) mutants exhibit hypoplasia of
their ventricular myocardium and die at the fetal stage. In the present study, we
wished to determine whether transgenic re-expression of RXRalpha in mutant
cardiac myocytes could rescue these defects. Two transgenic mouse lines
specifically overexpressing an RXRalpha protein in cardiomyocytes were generated,
using the cardiac alpha-myosin heavy chain (alpha-MHC) promoter. Breeding the
high copy number transgenic line onto an RXRalpha-null genetic background did not
prevent the myocardial hypoplasia and fetal lethality associated with the
RXRalpha(-/-) genotype, even though the transgene was expressed in the ventricles
as early as 10. 5 days post-coitum. These data suggest that the RXRalpha function
involved in myocardial growth may correspond to a non-cell-autonomous requirement
forsignal orchestrating the growth and differentiation of myocytes.
Interestingly, the adult transgenic mice developed a dilated cardiomyopathy,
associated with myofibrillar abnormalities and specific deficiencies in
respiratory chain complexes I and II, thus providing an additional model for this
genetically complex disease.
PMID- 10675367
TI - Relation of a recurrent intraductal carcinoma (ductal carcinoma in situ) to the
primary tumor.
PMID- 10675368
TI - Is ATP (adenosine 5'-triphosphate), like STP, a performance-enhancing additive
for the tanks of cancer patients?
PMID- 10675371
TI - HER2 testing methods
PMID- 10675370
TI - Common techniques used to detect HER2
PMID- 10675369
TI - Experts debate value of HER2 testing methods.
PMID- 10675372
TI - San Antonio Breast Cancer Symposium explores DCIS "battleground".
PMID- 10675373
TI - Stat bite: Use of fecal occult blood test in the United States.
PMID- 10675374
TI - Arthritis drug approved for polyp prevention blazes trail for other prevention
trials.
PMID- 10675375
TI - Old drugs find new life
PMID- 10675376
TI - NIH receives a 14.9% increase in fiscal year 2000.
PMID- 10675377
TI - Celecoxib trials under Way
PMID- 10675378
TI - NJ insurers agree to pay for trials.
PMID- 10675379
TI - History of breast-feeding in relation to breast cancer risk: a review of the
epidemiologic literature.
AB - The purpose of this review is to critically evaluate the collective epidemiologic
evidence that a history of breast-feeding may decrease the risk of breast cancer.
Original data for inclusion were identified through a MEDLINE(R) search of the
English language literature from 1966 through 1998. To date, virtually all
epidemiologic data regarding breast-feeding and breast cancer risk are derived
from case-control studies, which vary according to classification of breast
feeding history. Overall, the evidence with respect to "ever" breast-feeding
remains inconclusive, with results indicating either no association or a rather
weak protective effect against breast cancer. An inverse association between
increasing cumulative duration of breast-feeding and breast cancer risk among
parous women has been reported in some, but not all, studies; the failure to
detect an association in some Western populations may be due to the low
prevalence of prolonged breast-feeding. It appears that the protective effect, if
any, of long-term breast-feeding is stronger among, or confined to, premenopausal
women. It has been hypothesized that an apparently protective effect of breast
feeding may be due to elevated breast cancer risk among women who discontinue
breast-feeding or who take medication to suppress lactation; however, the
evidence is limited and should be interpreted with caution. The biology
underlying a protective effect of breast-feeding and why this should be
restricted to premenopausal women remain unknown, although several mechanisms
have been postulated (hormonal changes, such as reduced estrogen; removal of
estrogens through breast fluid; excretion of carcinogens from breast tissue
through breast-feeding; physical changes in the mammary epithelial cells,
reflecting maximal differentiation; and delay of the re-establishment of
ovulation). While breast-feeding is a potentially modifiable behavior, the
practical implication of reduced breast cancer risk among premenopausal women
with prolonged durations of breast-feeding may be of marginal importance,
particularly in Western societies.
PMID- 10675380
TI - Chromosomal alterations in ductal carcinomas in situ and their in situ
recurrences.
AB - BACKGROUND: Ductal carcinoma in situ (DCIS) recurs in the same breast following
breast-conserving surgery in 5%-25% of patients, with the rate influenced by the
presence or absence of involved surgical margins, tumor size and nuclear grade,
and whether or not radiation therapy was performed. A recurrent lesion arising
soon after excision of an initial DCIS may reflect residual disease, whereas in
situ tumors arising after longer periods are sometimes considered to be second
independent events. The purpose of this study was to determine the clonal
relationship between initial DCIS lesions and their recurrences. METHODS:
Comparative genomic hybridization (CGH) was used to compare chromosomal
alterations in 18 initial DCIS lesions (presenting in the absence of invasive
disease) and in their subsequent ipsilateral DCIS recurrences (detected from 16
months to 9.3 years later). RESULTS: Of the 18 tumor pairs, 17 showed a high
concordance in their chromosomal alterations (median = 81%; range = 65%-100%),
while one case showed no agreement between the paired samples (having two and 20
alterations, respectively). Morphologic characterization of the DCIS pairs showed
clear similarities. The mean number of CGH changes was greater in the recurrent
tumors than in the initial lesions (10.7 versus 8.8; P =.019). The most common
changes in both the initial and the recurrent in situ lesions were gains
involving chromosome 17q and losses involving chromosomes 8p and 17p. The degree
of concordance was independent of the time interval before recurrence and of the
presence of positive surgical margins. CONCLUSIONS: In this study, DCIS
recurrences were clonally related to their primary lesions in most cases. This
finding is consistent with treatment paradigms requiring wide surgical margins
and/or postoperative radiation therapy.
PMID- 10675381
TI - Randomized clinical trial of adenosine 5'-triphosphate in patients with advanced
non-small-cell lung cancer.
AB - BACKGROUND: Extracellular adenosine 5'-triphosphate (ATP) is involved in the
regulation of a variety of biologic processes, including neurotransmission,
muscle contraction, and liver glucose metabolism, via purinergic receptors. In
nonrandomized studies involving patients with different tumor types including non
small-cell lung cancer (NSCLC), ATP infusion appeared to inhibit loss of weight
and deterioration of quality of life (QOL) and performance status. We conducted a
randomized clinical trial to evaluate the effects of ATP in patients with
advanced NSCLC (stage IIIB or IV). METHODS: Fifty-eight patients were randomly
assigned to receive either 10 intravenous 30-hour ATP infusions, with the
infusions given at 2- to 4-week intervals, or no ATP. Outcome parameters were
assessed every 4 weeks until 28 weeks. Between-group differences were tested for
statistical significance by use of repeated-measures analysis, and reported P
values are two-sided. RESULTS: Twenty-eight patients were allocated to receive
ATP treatment and 30 received no ATP. Mean weight changes per 4-week period were
1.0 kg (95% confidence interval [CI] = -1.5 to -0.5) in the control group and 0.2
kg (95% CI = -0.2 to +0.6) in the ATP group (P =.002). Serum albumin
concentration declined by -1.2 g/L (95% CI= -2.0 to -0.4) per 4 weeks in the
control group but remained stable (0.0 g/L; 95% CI = -0.3 to +0.3) in the ATP
group (P =.006). Elbow flexor muscle strength declined by -5.5% (95% CI = -9.6%
to -1. 4%) per 4 weeks in the control group but remained stable (0.0%; 95% CI=
1.4% to +1.4%) in the ATP group (P =.01). A similar pattern was observed for knee
extensor muscles (P =.02). The effects of ATP on body weight, muscle strength,
and albumin concentration were especially marked in cachectic patients (P =.0002,
P =.0001, and P =. 0001, respectively, for ATP versus no ATP). QOL score changes
per 4-week period in the ATP group showed overall less deterioration than in the
control group-physical scores (-0.2% versus -2.4%; P =. 0002); functional scores
(+0.4% versus -5.5%; P =.02); psychologic scores (-0.7% versus -2.4%; P =.11);
overall QOL score (+0.1% versus -3.5%; P =.0001). CONCLUSIONS: This randomized
trial demonstrates that ATP has beneficial effects on weight, muscle strength,
and QOL in patients with advanced NSCLC.
PMID- 10675382
TI - Effect of hormone replacement therapy on breast cancer risk: estrogen versus
estrogen plus progestin.
AB - BACKGROUND: Hormone replacement therapy (HRT) given as unopposed estrogen
replacement therapy (ERT) gained widespread popularity in the United States in
the 1960s and 1970s. Recent prescribing practices have favored combination HRT
(CHRT), i.e., adding a progestin to estrogen for the entire monthly cycle
(continuous combined replacement therapy [CCRT]) or a part of the cycle
(sequential estrogen plus progestin therapy [SEPRT]). Few data exist on the
association between CHRT and breast cancer risk. We determined the effects of
CHRT on a woman's risk of developing breast cancer in a population-based, case
control study. METHODS: Case subjects included those with incident breast cancers
diagnosed over 4(1/2) years in Los Angeles County, CA, in the late 1980s and
1990s. Control subjects were neighborhood residents who were individually matched
to case subjects on age and race. Case subjects and control subjects were
interviewed in person to collect information on known breast cancer risk factors
as well as on HRT use. Information on 1897 postmenopausal case subjects and on
1637 postmenopausal control subjects aged 55-72 years who had not undergone a
simple hysterectomy was analyzed. Breast cancer risks associated with the various
types of HRT were estimated as odds ratios (ORs) after adjusting simultaneously
for the different forms of HRT and for known risk factors of breast cancer. All P
values are two-sided. RESULTS: HRT was associated with a 10% higher breast cancer
risk for each 5 years of use (OR(5) = 1.10; 95% confidence interval [CI] = 1.02
1.18). Risk was substantially higher for CHRT use (OR(5) = 1.24; 95% CI = 1.07
1.45) than for ERT use (OR(5) = 1. 06; 95% CI = 0.97-1.15). Risk estimates were
higher for SEPRT (OR(5) = 1.38; 95% CI = 1.13-1.68) than for CCRT (OR(5) = 1.09;
95% CI = 0. 88-1.35), but this difference was not statistically significant.
CONCLUSIONS: This study provides strong evidence that the addition of a progestin
to HRT enhances markedly the risk of breast cancer relative to estrogen use
alone. These findings have important implications for the risk-benefit equation
for HRT in women using CHRT.
PMID- 10675383
TI - Cigar smoking in men and risk of death from tobacco-related cancers.
AB - BACKGROUND: Cigar consumption in the United States has increased dramatically
since 1993, yet there are limited prospective data on the risk of cancer
associated with cigar smoking. We examined the association between cigar smoking
and death from tobacco-related cancers in a large, prospective cohort of U. S.
men. METHODS: We used Cox proportional hazards models to analyze the relationship
between cigar smoking at baseline in 1982 and mortality from cancers of the lung,
oral cavity/pharynx, larynx, esophagus, bladder, and pancreas over 12 years of
follow-up of the American Cancer Society's Cancer Prevention Study II cohort. A
total of 137 243 men were included in the final analysis. Women were not included
because we had no data on their cigar use. We excluded men who ever smoked
cigarettes or pipes and adjusted all rate ratio (RR) estimates for age, alcohol
use, and use of snuff or chewing tobacco. RESULTS: Current cigar smoking at
baseline, as compared with never smoking, was associated with an increased risk
of death from cancers of the lung (RR = 5.1; 95% confidence interval [CI] = 4.0
6.6), oral cavity/pharynx (RR = 4.0 [95% CI = 1.5-10.3]), larynx (RR = 10.3 [95%
CI = 2.6-41.0]), and esophagus (RR = 1.8; 95% CI = 0.9-3.7). Although current
cigar smokers overall did not appear to be at an increased risk of death from
cancer of the pancreas (RR = 1.3; 95% CI = 0.9-1.9) or bladder (RR = 1.0; 95% CI
= 0.4-2.3), there was an increased risk for current cigar smokers who reported
that they inhaled the smoke (for pancreas, RR = 2.7; 95% CI = 1.5-4.8; for
bladder, RR = 3.6; 95% CI = 1.3-9.9). CONCLUSIONS: Results from this large
prospective study support a strong association between cigar smoking and
mortality from several types of cancer.
PMID- 10675384
TI - Restored expression of fragile histidine triad protein and tumorigenicity of
cervical carcinoma cells.
AB - BACKGROUND: Allelic losses in the short arm of chromosome 3 are common in
cervical carcinomas. The fragile histidine triad (FHIT) gene at chromosome region
3p14.2 is a candidate tumor suppressor gene that may play a role in cervical
tumorigenesis. We and others have identified aberrant FHIT transcripts and
frequent loss of Fhit protein expression in primary cervical cancers and high
grade noninvasive lesions but not in normal cervical tissues. The altered
expression of FHIT may be due to somatic mutations or integration of human
papillomavirus DNA at the FHIT locus. The purpose of this study was to determine
whether ectopic expression of Fhit can suppress the tumorigenic properties of
cervical cancer cells. METHODS: We employed infection with recombinant
retroviruses as well as transfection of plasmid DNA to restore Fhit protein
expression in cervical cancer cell lines lacking full-length FHIT transcripts and
endogenous Fhit protein. The effects of Fhit expression on tumor cell morphology,
anchorage-independent growth, and tumorigenicity in nude mice were examined.
RESULTS: Stable overexpression of Fhit had no discernible effect on the
tumorigenic properties of two cervical carcinoma cell lines or on a lung
carcinoma cell line previously reported by others to be suppressed for
tumorigenicity by Fhit. CONCLUSIONS: Restoration of Fhit expression does not
suppress anchorage-independent growth or tumorigenicity of cervical carcinoma
cell lines. However, it remains possible that FHIT inactivation may be important
early in cervical tumor progression or that FHIT may suppress tumorigenesis in
ways distinct from those measured by the assays employed in this study.
PMID- 10675386
TI - RESPONSE: re: antiangiogenic activity of prostate-specific antigen
PMID- 10675385
TI - Re: Antiangiogenic activity of prostate-specific antigen.
PMID- 10675387
TI - Re: Enhancement of tumor response to gamma-radiation by an inhibitor of
cyclooxygenase-2 enzyme.
PMID- 10675388
TI - RESPONSE: re: enhancement of tumor response to gamma-radiation by an inhibitor of
cyclooxygenase-2 enzyme
PMID- 10675389
TI - Re: Dormancy of mammary carcinoma after mastectomy.
PMID- 10675390
TI - RESPONSE: re: dormancy of mammary carcinoma after mastectomy
PMID- 10675392
TI - PSYCHOSOMATICS: Information for Contributors.
PMID- 10675391
TI - Consultation-Liaison Psychiatry: Drug-Drug Interactions Update.
PMID- 10675393
TI - Identification of a pathogenicity determinant of Plum pox virus in the sequence
encoding the C-terminal region of protein P3+6K(1).
AB - A full-length genomic cDNA clone of a plum pox potyvirus (PPV) isolate belonging
to the M strain (PPV-PS) has been cloned downstream from a bacteriophage T7
polymerase promoter and sequenced. Transcripts from the resulting plasmid,
pGPPVPS, were infectious and, in herbaceous hosts, produced symptoms that
differed from those of virus progeny of pGPPV, a full-length genomic cDNA clone
of the D strain PPV-R. Viable PPV-R/-PS chimeric viruses were constructed by
recombination of the cDNA clones in vitro. Analysis of plants infected with the
different chimeras indicated that sequences encoding the most variable regions of
the potyvirus genome, the P1 and capsid protein coding sequences, were not
responsible for symptom differences between the two PPV isolates in herbaceous
hosts. On the contrary, complex symptomatology determinants seem to be located in
the central region of the PPV genome. The results indicate that a genomic
fragment that encodes 173 aa from the C-terminal part of the P3+6K(1) coding
region is enough to confer, on a PPV-R background, a PS phenotype in Nicotiana
clevelandii. This pathogenicity determinant also participates in symptom
induction in Pisum sativum, although the region defining the PS phenotype in this
host is probably restricted to 74 aa.
PMID- 10675394
TI - Mutations in the coat protein gene of plum pox virus suppress particle assembly,
heterologous encapsidation and complementation in transgenic plants of Nicotiana
benthamiana.
AB - Two different motifs in the coat protein (CP) of Plum pox virus (PPV)
(R(3015)Q(3016), D(3059)) were mutated by replacing the respective amino acids
with others possessing different chemical properties. The mutated CP genes were
introduced into an infectious full-length clone of PPV (p35PPV-NAT) to
investigate their influence on systemic infection of transgenic wild-type PPV CP
expressing and non-transgenic plants of Nicotiana benthamiana. All mutants failed
to establish systemic infections in non-transgenic N. benthamiana plants, but
were complemented by intact CP in transgenic plants. Moreover, the CP-RQ-D mutant
(carrying mutations in both the RQ and D motifs) was introduced into p35PPV-NAT
engineered to express beta-glucuronidase (GUS) for direct observation of systemic
movement and particle assembly in N. benthamiana leaves. GUS-staining revealed
that the CP mutant (RQ-D) was restricted to initially infected cells without
forming virions. Systemic movement and particle assembly were restored in CP
transgenic N. benthamiana plants. Finally, transgenic N. benthamiana plants were
generated that expressed each of the three mutated CP genes. Homozygous T(2)
lines were selected and tested for resistance to PPV. Immunogold labelling and
electron microscopy revealed that heterologous encapsidation with challenging
Chilli veinal mottle virus and Potato virus Y was suppressed in these lines. In
addition, assembly mutants did not complement CP-defective p35PPV-NAT. The
possible use of modified viral CP genes for the production of virus-resistant
transgenic plants, thereby reducing the putative risks of heterologous
encapsidation and complementation, is discussed.
PMID- 10675395
TI - Heterogeneity in the 3'-terminal untranslated region of tobacco mild green mosaic
tobamoviruses from Nicotiana glauca resulting in variants with three or six
pseudoknots.
AB - Isolates of tobacco mild green mosaic tobamovirus (TMGMV) were obtained from 58
plants of Nicotiana glauca in southern California and placed in one of two groups
(Small type and Large type) based on the size of the subgenomic RNA for the coat
protein (CP). The CP sequence differed by no more than one amino acid for the two
types, and the Small type was identical to that published for TMGMV. Thirty-six
of the isolates had a double-stranded (ds)RNA profile that matched that of type
TMGMV, and the nucleotide sequence of the 3' untranslated region (3'UTR) of six
of these isolates was similar to the published sequence of TMGMV. Twenty-two
isolates had a larger dsRNA for the CP subgenomic RNA. Six of these were
sequenced and all had a repeat sequence of between 147 and 165 bases in the part
of the 3'UTR that is involved in the formation of pseudoknots. These novel but
common isolates are predicted to have six rather than three pseudoknots. Small
types (three pseudoknots=type TMGMV) yielded twice as much virus after
purification as Large types (six pseudoknots). The two groups of isolates could
be distinguished in N. rustica (Large type, but not Small type gave a systemic
infection), and N. clevelandii (Small type but not Large type induced systemic
lethal necrosis). Almost all isolates of TMGMV used in this study were initially
associated with satellite tobacco mosaic virus (STMV), and both types supported
STMV experimentally.
PMID- 10675396
TI - Transgene translatability increases effectiveness of replicase-mediated
resistance to cucumber mosaic virus.
AB - Transgenic tobacco plants expressing an altered form of the 2a replicase gene
from the Fny strain of Cucumber mosaic virus (CMV) exhibit suppressed virus
replication and restricted virus movement when inoculated mechanically or by
aphid vectors. Additional transformants have been generated which contain
replicase gene constructs designed to determine the role(s) of transgene mRNA
and/or protein in resistance. Resistance to systemic disease caused by CMV, as
well as delayed infection, was observed in several lines of transgenic plants
which were capable of expressing either full-length or truncated replicase
proteins. In contrast, among plants which contained nontranslatable transgene
constructs, only one of 61 lines examined exhibited delays or resistance. Once
infected, plants never recovered, regardless of transgene translatability.
Transgenic plants exhibiting a range of resistance levels were examined for
transgene copy number, mRNA and protein levels. Although ribonuclease protection
assays demonstrated that transgene mRNA levels were very low, resistant lines had
consistently more steady-state transgene mRNA than susceptible lines.
Furthermore, chlorotic or necrotic local lesions developed on the inoculated
leaves of transgenic lines containing translatable transgenes, but not on
inoculated leaves of lines containing nontranslatable transgenes. These results
demonstrate that translatability of the transgene and possibly expression of the
transgene protein itself facilitates replicase-mediated resistance to CMV in
tobacco.
PMID- 10675397
TI - Detection of beet yellows closterovirus methyltransferase-like and helicase-like
proteins in vivo using monoclonal antibodies.
AB - In the positive-stranded RNA genome of beet yellows closterovirus (BYV), the 5'
terminal ORF 1a encodes a 295 kDa polyprotein with the domains of papain-like
cysteine proteinase, methyltransferase (MT) and helicase (HEL), whereas ORF 1b
encodes an RNA-dependent RNA polymerase. Eleven and five hybridoma cell lines
secreting monoclonal antibodies (MAbs) were derived from mice injected with the
bacterially expressed fragments of the BYV 1a product encompassing the MT and HEL
domains, respectively. On immunoblots of protein from BYV-infected Tetragonia
expansa plants, four MAbs against the MT recognized a approximately 63 kDa
protein, and two MAbs against the HEL recognized a approximately 100 kDa protein.
Both the methyltransferase-like protein and the helicase-like protein were found
mainly in the fractions of large organelles (P1) and membranes (P30) of the
infected plants. These data clearly indicate that (i) the BYV methyltransferase
like and helicase-like proteins, like other related viral enzymes, are associated
with membrane compartments in cells, and (ii) the 1a protein, apart from the
cleavage by the leader papain-like proteinase that is expected to produce the 66
kDa and 229 kDa fragments, undergoes additional processing by a virus-encoded or
cellular proteinase.
PMID- 10675398
TI - Nucleotide sequence and organization of ten open reading frames in the genome of
grapevine leafroll-associated virus 1 and identification of three subgenomic
RNAs.
AB - The genome of Grapevine leafroll-associated virus 1 (GLRaV-1) was cloned and the
sequence of 12394 nts determined. It contains 10 major open reading frames (ORFs)
and a 3'-non-coding region lacking a poly(A) tract. The first ORF (ORF 1a)
encodes a putative RNA helicase at the C-terminal portion of an apparently larger
protein. The downstream ORF, 1b, overlaps ORF 1a and lacks an initiation codon.
This ORF encodes an RNA-dependent RNA polymerase of M(r) 59276. ORF 2 encodes a
small hydrophobic protein of M(r) 6736, and ORF 3 encodes a homologue of the
HSP70 family of heat shock proteins and has an M(r) of 59500. ORF 4 encodes a
protein with an M(r) of 54648 that shows similarity to the corresponding proteins
of other closteroviruses. ORF 5 encodes the viral coat protein (CP) with an M(r)
of 35416. The identity of this ORF as the CP gene was confirmed by expression in
Escherichia coli and testing with the viral antibody. ORFs 6 and 7 code for two
CP-related products with M(r) of 55805 and 50164, respectively. ORFs 8 and 9
encode proteins of M(r) 21558 and 23771 with unknown functions. Using DNA probes
to different regions of the GLRaV-1 sequence, three major 3'-coterminal
subgenomic RNA species were identified and mapped on the GLRaV-1 genome.
Phylogenetic analyses of the individual genes of GLRaV-1 demonstrated a closer
relationship between GLRaV-1 and GLRaV-3 than with other closteroviruses.
PMID- 10675399
TI - Tagging potato leafroll virus with the jellyfish green fluorescent protein gene.
AB - A full-length cDNA corresponding to the RNA genome of Potato leafroll virus
(PLRV) was modified by inserting cDNA that encoded the jellyfish green
fluorescent protein (GFP) into the P5 gene near its 3' end. Nicotiana benthamiana
protoplasts electroporated with plasmid DNA containing this cDNA behind the 35S
RNA promoter of Cauliflower mosaic virus became infected with the recombinant
virus (PLRV-GFP). Up to 5% of transfected protoplasts showed GFP-specific
fluorescence. Progeny virus particles were morphologically indistinguishable from
those of wild-type PLRV but, unlike PLRV particles, they bound to grids coated
with antibodies to GFP. Aphids fed on extracts of these protoplasts transmitted
PLRV-GFP to test plants, as shown by specific fluorescence in some vascular
tissue and epidermal cells and subsequent systemic infection. In plants
agroinfected with PLRV-GFP cDNA in pBIN19, some cells became fluorescent and
systemic infections developed. However, after either type of inoculation,
fluorescence was mostly restricted to single cells and the only PLRV genome
detected in systemically infected tissues lacked some or all of the inserted GFP
cDNA, apparently because of naturally occurring deletions. Thus, intact PLRV-GFP
was unable to move from cell to cell. Nevertheless, PLRV-GFP has novel potential
for exploring the initial stages of PLRV infection.
PMID- 10675400
TI - The non-essential UL50 gene of avian infectious laryngotracheitis virus encodes a
functional dUTPase which is not a virulence factor.
AB - The DNA sequence of the infectious laryngotracheitis virus (ILTV) UL50, UL51 and
UL52 gene homologues was determined. Although the deduced UL50 protein lacks the
first of five conserved domains of the corresponding proteins of mammalian
alphaherpesviruses, the ILTV gene product was also shown to possess dUTPase
activity. The generation of UL50-negative ILTV mutants was facilitated by
recombination plasmids encoding green fluorescent protein (GFP), and expression
constructs of predicted transactivator proteins of ILTV (alphaTIF, ICP4) were
successfully used to increase the infectivity of viral genomic DNA. A GFP
expressing UL50-deletion mutant of ILTV showed reduced cell-to-cell spread in
vitro, and was attenuated in vivo. A similar deletion mutant without the foreign
gene, however, propagated like wild-type ILTV in cell culture and was pathogenic
in chickens. We conclude that the viral dUTPase is not required for efficient
replication of ILTV in the respiratory tract of infected animals. The replication
defect of the GFP-expressing ILTV recombinant is most likely caused by toxic
effects of the reporter gene product, since spontaneously occurring inactivation
mutants exhibited wild-type-like growth.
PMID- 10675401
TI - Resistance of herpes simplex virus type 1 against different
phosphonylmethoxyalkyl derivatives of purines and pyrimidines due to specific
mutations in the viral DNA polymerase gene.
AB - Drug-resistant strains of herpes simplex virus type 1 (HSV-1) were selected under
the pressure of (S)-3-hydroxy-2-phosphonylmethoxypropyl (HPMP) derivatives of
cytosine (HPMPC, cidofovir) and adenine (HPMPA) and 2-phosphonylmethoxyethyl
(PME) derivatives of adenine (PMEA, adefovir) and 2,6-diaminopurine (PMEDAP).
HPMPC-resistant (HPMPC(r)) and HPMPA(r) strains were cross-resistant to one
another, but they remained sensitive to foscarnet (PFA), acyclovir (ACV) and the
PME derivatives, while the PMEA(r) and PMEDAP(r) strains showed cross-resistance
to PFA and ACV. The PMEA(r), PMEDAP(r) and PFA(r) mutants all revealed a single
nucleotide change resulting in a Ser-724 to Asn mutation within the conserved
region II of the DNA polymerase. Two HPMPA(r) clones and one HPMPC(r) clone
possessed single amino acid changes in the DNA polymerase (HPMPA(r) clone D1, Leu
1007 to Met; HPMPA(r) clone B5, Ile-1028 to Thr; HPMPC(r) clone C3, Val-573 to
Met). The HPMPC(r) clone A4 contained two mutations, Ala-136 to Thr and Arg-700
to Met. The mutation at position 136, located outside the catalytic domain of the
enzyme, was not detected in other HPMPC(r) clones, suggesting that this mutation
may not be responsible for the resistant phenotype. Residue 573 is located within
the 3'-->5' exonuclease editing domain close to the catalytically important
residues Tyr-577 and Asp-581. Similarly, residue 700 is located in the palm
subdomain of the catalytic domain, adjacent to the Asp residues 717, 886 and 888
that are vital for polymerase activity. The HPMPA(r) mutations at residues 1007
and 1028, beyond the last conserved region, still fall within the thumb subdomain
of the catalytic domain. The different drug-resistant mutants varied in
neurovirulent behaviour, the HPMPC(r) strains showing reduced neurovirulence
compared with the wild-type.
PMID- 10675402
TI - Expression from the herpes simplex virus type 1 latency-associated promoter in
the murine central nervous system.
AB - Herpes simplex virus type 1 (HSV-1) establishes latency in neurones of both the
central (CNS) and peripheral nervous system and can be used to drive long-term
expression of the lacZ reporter gene by insertion of an encephalomyocarditis
virus IRES-linked gene 1.5 kb downstream of the latency-associated transcript
(LAT) start site. However, the kinetics of LAT promoter (LAP) activity, and its
ability to function in all neuronal types within the CNS has not been studied in
detail. In order to address these issues, mice were infected via the ear pinna
with 2x10(6) p.f.u. of either SC16-LbetaA, which contains an IRES-linked lacZ
under the control of LAP, or SC16-C3b, which expresses LacZ under the control of
the human cytomegalovirus immediate early (HCMV-IE) promoter. Three to five
animals from each group were sampled over a time-course from 5 days to 1 year
post-infection (p.i.), and brainstem and spinal cord sections were examined
histochemically for LacZ expression. We found that HCMV-IE promoter activity
could be detected within distinct CNS regions from 5 to 15 days p.i. In contrast,
LAP-driven LacZ expression was first detected at 7 days p.i. and persisted for at
least 1 year. At times up to 34 days p.i., LAP activity was seen in similar
regions of the CNS as those which were positive for HCMV-IE promoter activity
during the acute stage of infection. After 34 days, however, the numbers of cells
in which the LAP was active decreased and labelled motorneurones were
predominantly detected in the facial and hypoglossal nuclei and occasionally also
in the ventral spinal cord. These results suggest that following the
establishment of latency in the CNS, the efficiency of long-term LAP-mediated
gene expression may be influenced by the neuronal cell type in which latency is
established.
PMID- 10675403
TI - Suppressive effects of human herpesvirus-6 on thrombopoietin-inducible
megakaryocytic colony formation in vitro.
AB - Two clinical observations, the association of human herpesvirus-6 (HHV-6) with
delayed engraftment after stem cell transplantation and thrombocytopenia
concomitant with exanthema subitum, prompted us to evaluate the suppressive
effects of HHV-6 on thrombopoiesis in vitro. Different culture conditions for
thrombopoietin (TPO)-inducible colonies in semi-solid matrices were examined.
Using cord blood mononuclear cells as the source of haematopoietic progenitors,
two types of colonies, megakaryocyte colony-forming units (CFU-Meg) and non-CFU
Meg colonies, were established. The former colonies were identified by the
presence of cells with translucent cytoplasm and highly refractile cell membrane,
most of which were positive for the CD41 antigen. Although the plating efficiency
of both types was much higher under serum-containing conditions than under serum
free conditions, the proportion of CFU-Meg to non-CFU-Meg colonies was
consistently higher under serum-free conditions. The plating efficiency of CFU
Meg colonies was doubled by adding stem cell factor to the serum-free matrix. The
effects of two variants of HHV-6 (HHV-6A and 6B) and human herpesvirus-7 (HHV-7)
on TPO-inducible colonies were then compared. HHV-6B inhibited both CFU-Meg and
non-CFU-Meg colony formation under serum-free and serum-containing conditions.
HHV-6A had similar inhibitory effects. In contrast, HHV-7 had no effect on TPO
inducible colony formation. Heat-inactivation and ultra-filtration of the virus
sample completely abolished the suppressive effect. After infection of CD34(+)
cells with HHV-6, the viral genome was consistently detected by in situ
hybridization. These data suggest that the direct effect of HHV-6 on
haematopoietic progenitors is one of the major causes of the suppression of
thrombopoiesis.
PMID- 10675404
TI - Morphogenesis and release of fowlpox virus.
AB - Release of fowlpox virus (FWPV) as extracellular enveloped virus (EEV) appears to
proceed both by the budding of intracellular mature virus (IMV) through the
plasma membrane and by the fusion of intracellular enveloped virus (IEV) with the
plasma membrane. Based on the frequency of budding events compared to wrapping
events observed by electron microscopy, FWPV FP9 strain seems to exit chick
embryo fibroblast cells predominantly by budding. In contrast to vaccinia virus
(VV), the production of FWPV extracellular virus particles is not affected by
N(1)-isonicotinoyl-N(2)-3-methyl-4-chlorobenzoylhydrazine (IMCBH). Comparison of
the sequence of the VV F13L gene product with its FWPV orthologue showed a
mutation, in the fowlpox protein, at the residue involved in IMCBH resistance in
a mutant VV. Glucosamine, monensin or brefeldin A did not have any specific
effect on FWPV extracellular virus production. Cytochalasin D, which inhibits the
formation of actin filaments, reduces the production of extracellular virus
particles by inhibiting the release of cell-associated enveloped virus (CEV)
particles from the plasma membrane. Involvement of actin filaments in this
mechanism is further supported by the co-localization of actin with viral
particles close to the plasma membrane in the absence of cytochalasin D. Actin is
also co-localized with virus factories.
PMID- 10675405
TI - Binding of bovine papillomavirus type 4 E8 to ductin (16K proteolipid), down
regulation of gap junction intercellular communication and full cell
transformation are independent events.
AB - The E8 open reading frame of bovine papillomavirus type 4 encodes a small
hydrophobic polypeptide that contributes to primary cell transformation by
conferring to cells the ability to form foci and to grow in low serum and in
suspension. Wild-type E8 binds in vitro to ductin, a component of gap junctions,
and this binding is accompanied by a loss of gap junction intercellular
communication in transformed bovine fibroblasts. However, through the analysis of
a panel of E8 mutants, we show here that binding of E8 to ductin is not
sufficient for down-regulation of gap junction communication and that there is no
absolute correlation between down-regulation of gap junction communication and
the transformed phenotype.
PMID- 10675406
TI - The effects of interferon on the expression of human papillomavirus oncogenes.
AB - The effects of interferon (IFN)-alpha, IFN-beta and IFN-gamma on human
papillomavirus (HPV) oncogene expression were studied in various cervical
carcinoma cell lines containing integrated copies of either HPV type 16 or HPV
type 18. The levels of E6 and E7 transcripts were examined 6 h and 30 h after
treatment with IFN. In HeLa cells, all three classes of IFNs effected a decrease
in the level of HPV-18 E6 and E7 transcripts. On the other hand, none of the IFNs
altered the level of these transcripts in C-4II cells. Only IFN-gamma decreased
the level of HPV-16 E6 and E7 transcripts in CaSki and HPK1A cells, while IFN
gamma actually increased the level of these transcripts in SiHa cells. This
differential IFN regulation of HPV expression in various cervical cancer cell
lines may account for the contradictory clinical results observed after treatment
of cervical cancer with IFN.
PMID- 10675407
TI - Specific serum IgG, IgM and IgA antibodies to human papillomavirus types 6, 11,
16, 18 and 31 virus-like particles in human immunodeficiency virus-seropositive
women.
AB - To evaluate the humoral immune response to human papillomavirus (HPV) in women
infected with human immunodeficiency virus (HIV), serum samples of 83 HIV
positive individuals were analysed by ELISA for specific antibodies of the
isotypes IgG, IgA and IgM recognizing HPV-6, -11, -16, -18 and -31 L1 virus-like
particles (VLPs). Papillomavirus-related lesions were present in 30 of 83 HIV
positive women. Twenty-one women (25%) presented with high-/intermediate-grade
anogenital squamous intraepithelial lesions. PCR analysis and sequencing for HPV
typing was done from biopsy specimens of 18 women; PCR-positive results were
obtained in 90% of cases. In addition, HPV DNA hybrid capture assays were
performed from cervical swabs of 58 HIV-positive women, 53% of whom had a
positive result for high-risk HPV. Overall, positive IgG reactivity to HPV-6/-11
and HPV-16/-18/-31 was seen in 19%/31% and 49%/30%/24% of HIV-positive women,
respectively. HPV-seropositivity was even higher than in 48 HIV-negative cervical
intraepithelial neoplasia/cancer patients with percentages as follows: 8%/2% and
31%/15%/15%. This difference was significant for HPV-16 (P=0.046). IgA responses
were comparable to IgG. IgM responses were low. The extraordinarily high rate of
antibodies to the capsid protein L1 of high-risk HPVs (HPV-16, -18 and/or -31) in
58% of HIV-positive women compared to 19% (P=0.00001) of 102 healthy HIV-negative
control women suggests a high lifetime cumulative exposure to HPV and increased
expression of capsid proteins due to cellular immunodeficiency in HIV-infected
women.
PMID- 10675408
TI - Development of a genetically marked recombinant rinderpest vaccine expressing
green fluorescent protein.
AB - In order to effectively control and eliminate rinderpest, a method is required to
allow serological differentiation between animals that have been vaccinated and
those which have recovered from natural infection. One way of doing this would be
to engineer the normal vaccine to produce a genetically marked rinderpest virus
(RPV) vaccine. We constructed two modified cDNA clones of the RPV RBOK vaccine
strain with the coding sequence of the green fluorescent protein (GFP) gene
inserted as a potential genetic marker. RPVINS-GFP virus was designed to produce
independent and high level expression of GFP inside infected cells, whilst the
GFP expressed by RPVSIG-GFP virus was designed to be efficiently secreted.
Infectious recombinant virus was rescued in cell culture from both constructs.
The effectiveness of these viruses in stimulating protective immunity and
antibody responses to the marker protein was tested by vaccination of cattle and
goats. All of the vaccinated animals were completely protected when challenged
with virulent virus: RPV in cattle or peste-des-petits ruminants virus in the
goats. ELISA showed that all of the animals produced good levels of anti-RPV
antibodies. Three of the four cattle and the two goats vaccinated with RPVSIG-GFP
produced detectable levels of anti-GFP antibodies. In contrast, no anti-GFP
antibodies were produced in the four cattle and two goats vaccinated with RPVINS
GFP. Therefore, secretion of the GFP marker protein was absolutely required to
elicit an effective humoral antibody response to the marker protein.
PMID- 10675409
TI - An amino acid in the heptad repeat 1 domain is important for the haemagglutinin
neuraminidase-independent fusing activity of simian virus 5 fusion protein.
AB - A canine isolate (strain T1) of simian virus 5 (SV-5) performed multiple
replication in BHK cells but did not induce cell fusion for up to 3 days. In
contrast, a prototype strain (WR) provoked extensive cell fusion within 2 days
during the course of its replication. Accordingly, the fusion (F) protein of the
T1 strain did not cause cell fusion even when co-expressed with the SV-5
haemagglutinin-neuraminidase (HN) protein, whereas the WR F protein induced cell
fusion in the presence of the HN protein. Differences in the predicted amino acid
sequences of the T1 and WR F proteins were found at 12 positions and it was
proved that the T1 F protein had a longer cytoplasmic tail than the WR F protein.
By reducing the length of the cytoplasmic tail or by replacing the tail with the
WR F counterpart, the T1 F protein partly restored its HN-dependent fusing
activity. Chimeric and mutational analyses between the T1 F protein and the
mutant F protein (L22P) suggested that Glu-132 in the heptad repeat 1 domain was
involved in the HN-independent fusing activity in addition to the previously
identified Pro-22 at the F(2) N terminus. It was also shown that Ala-290 in the
heptad repeat 3 domain contributed to the HN-independent fusing activity to some
extent.
PMID- 10675410
TI - Neutralization of measles virus wild-type isolates after immunization with a
synthetic peptide vaccine which is not recognized by neutralizing passive
antibodies.
AB - The sequence H379-410 of the measles virus haemagglutinin (MV-H) protein forms a
surface-exposed loop and contains three cysteine residues (Cys-381, Cys-386 and
Cys-394) which are conserved among all measles isolates. It comprises the minimal
sequential B cell epitope (BCE) (H386-400) of the neutralizing and protective MAb
BH6 that neutralizes all wild-type viruses tested. The aim of this study was to
design synthetic peptides which induce neutralizing antibodies against MV wild
type isolates. Peptides containing one or two copies of T cell epitopes (TCE) and
BCEs of different lengths (H386-400, B(CC); H379-400, B(CCC)), in different
combinations and orientations were produced and iteratively optimized for
inducing neutralizing antibodies. Peptides with the shorter BCE induced sera that
cross-reacted with MV but did not neutralize. The longer BCE containing the three
cysteines (B(CCC)) and two homologous TCE were required for neutralization
activity. These sera neutralized wild-type strains of different clades and
geographic origins. Neutralizing serum was also obtained after immunization with
human promiscuous TCEs. Furthermore B(CCC)-based peptides were fully immunogenic
even in the presence of pre-existing MV-specific antibodies. The results suggest
that subunit vaccines based on such peptides could potentially be used to
actively protect infants against wild-type viruses irrespective of persisting
maternal antibodies.
PMID- 10675411
TI - Reduced levels of neuraminidase of influenza A viruses correlate with attenuated
phenotypes in mice.
AB - We have previously obtained four transfectant influenza A viruses containing
neuraminidase (NA) genes with mutated base pairs in the conserved double-stranded
RNA region of the viral promoter by using a ribonucleoprotein transfection
system. Two mutant viruses (D2 and D1/2) which share a C-G-->A-U mutation at
positions 11 and 12 of the 3' and 5' ends, respectively, of the NA gene, showed
an approximate 10-fold reduction of NA-specific mRNA and protein levels (Fodor et
al., Journal of Virology 72, 6283-6290, 1998). These viruses have now allowed us
to determine the effects of decreased NA levels on virus pathogenicity. Both D2
and D1/2 viruses were highly attenuated in mice, and their replication in mouse
lungs was highly compromised as compared with wild-type influenza A/WSN/33 virus.
The results highlight the importance of the level of NA activity in the
biological cycle and virulence of influenza viruses. Importantly, mice immunized
by a single intranasal administration of 10(3) infectious units of D2 or D1/2
viruses were protected against challenge with a lethal dose of wild-type
influenza virus. Attenuation of influenza viruses by mutations resulting in the
decreased expression of a viral protein represents a novel strategy which could
be considered for the generation of live attenuated influenza virus vaccines.
PMID- 10675412
TI - Nucleotide sequences and phylogeny of the nucleocapsid gene of Oropouche virus.
AB - The nucleotide sequence of the S RNA segment of the Oropouche (ORO) virus
prototype strain TRVL 9760 was determined and found to be 754 nucleotides in
length. In the virion-complementary orientation, the RNA contained two
overlapping open reading frames of 693 and 273 nucleotides that were predicted to
encode proteins of 231 and 91 amino acids, respectively. Subsequently, the
nucleotide sequences of the nucleocapsid genes of 27 additional ORO virus
strains, representing a 42 year interval and a wide geographical range in South
America, were determined. Phylogenetic analyses revealed that all the ORO virus
strains formed a monophyletic group that comprised three distinct lineages.
Lineage I contained the prototype strain from Trinidad and most of the Brazilian
strains, lineage II contained six Peruvian strains isolated between 1992 and
1998, and two strains from western Brazil isolated in 1991, while lineage III
comprised four strains isolated in Panama during 1989.
PMID- 10675413
TI - Recombinant Semliki Forest virus particles expressing louping ill virus antigens
induce a better protective response than plasmid-based DNA vaccines or an
inactivated whole particle vaccine.
AB - Louping ill virus (LIV) infection of mice was used as a model to evaluate the
protective efficacy of Semliki Forest virus (SFV)-based vaccines in comparison to
a standard DNA vaccine and a commercial chemically inactivated vaccine. The
recombinant SFV-based vaccines consisted of suicidal particles and a naked
layered DNA/RNA construct. The nucleic acid vaccines expressed the spike
precursor prME and the nonstructural protein 1 (NS1) antigens of LIV. Three LIV
strains of graded virulence for mice were used for challenge. One of these was a
naturally occurring antibody escape variant. All vaccines tested induced humoral
immunity but gave varying levels of protection against lethal challenge. Only
recombinant SFV particles administered twice gave full protection against
neuronal degeneration and encephalitis induced by two of the three challenge
strains, and partial protection against the highly virulent strain, whereas the
other vaccines tested gave lower levels of partial protection.
PMID- 10675414
TI - Biochemical characterization of a hepatitis C virus RNA-dependent RNA polymerase
mutant lacking the C-terminal hydrophobic sequence.
AB - The RNA-dependent RNA polymerase activity of hepatitis C virus is carried out by
the NS5B protein. The full-length protein was previously purified as a non-fusion
protein from insect cells infected with a recombinant baculovirus. The
characterization is now described of a C-terminal hydrophobic domain deletion
mutant of NS5B purified from E. coli. In addition to increased solubility,
deletion of this sequence also positively affected the polymerase enzymatic
activity. The efficiency of nucleotide polymerization of both the full-length and
the C-terminal truncated enzymes were compared on homopolymeric template-primer
couples as well as on RNA templates with heteropolymeric sequences. The largest
difference in the polymerase activity was observed on the latter. On all the
templates, the increased activity could be ascribed, at least in part, to
enhanced template turnover of the deletion mutant with respect to the full-length
enzyme. The elongation rates of the two enzyme forms were compared under single
processive cycle conditions. Under these conditions, both the full-length and the
deletion mutant were able to incorporate about 700 nt/min.
PMID- 10675415
TI - Phylogenetic analysis of GBV-C/hepatitis G virus.
AB - Comparison of 33 epidemiologically distinct GBV-C/hepatitis G virus complete
genome sequences suggests the existence of four major phylogenetic groupings that
are equally divergent from the chimpanzee isolate GBV-C(tro) and have distinct
geographical distributions. These four groupings are not consistently reproduced
by analysis of the virus 5'-noncoding region (5'-NCR), or of individual genes or
subgenomic fragments with the exception of the E2 gene as a whole or of 200-600
nucleotide fragments from its 3' half. This region is upstream of a proposed anti
sense reading frame and contains conserved potential RNA secondary structures
that may be capable of directing the internal initiation of translation.
Phylogenetic analysis of this region from certain South African isolates is
consistent with previous analysis of the 5'-NCR suggesting that these belong to a
fifth group. The geographical distribution of virus variants is consistent with a
long evolutionary history that may parallel that of pre-historic human
migrations, implying that the long-term evolution of this RNA virus is extremely
slow.
PMID- 10675416
TI - Phylogeny of the genus flavivirus using complete coding sequences of arthropod
borne viruses and viruses with no known vector.
AB - Attempts to define the evolutionary relationships and origins of viruses in the
genus Flavivirus are hampered by the lack of genetic information particularly
amongst the non-vectored flaviviruses. Using a novel protocol for sequence
determination, the first complete coding sequence of St Louis encephalitis virus
and those of two representative non-vectored flaviviruses, Rio Bravo (isolated
from bat) and Apoi (isolated from rodent), are reported. The encoded polyproteins
of Rio Bravo and Apoi virus are the smallest described to date within the genus
FLAVIVIRUS: The highest similarities with other flaviviruses were found in the
NS3 and NS5 genes. The proteolytic cleavage sites for the viral serine protease
were highly conserved among the flaviviruses completely sequenced to date.
Comparative genetic amino acid alignments revealed that p-distance cut-off values
of 0.330-0.470 distinguished the arthropod-borne viruses according to their
recognized serogroups and Rio Bravo and Apoi virus were assigned to two distinct
non-vectored virus groups. Within these serogroups, cladogenesis based on the
complete ORF sequence was similar to trees based on envelope and NS5 sequences.
In contrast, branching patterns at the deeper nodes of the tree were different
from those reported in the previous study of NS5 sequences. The significance of
these observations is discussed.
PMID- 10675417
TI - Leader switching occurs during the rescue of defective RNAs by heterologous
strains of the coronavirus infectious bronchitis virus.
AB - A defective RNA (D-RNA), CD-61, derived from the Beaudette strain of the avian
coronavirus infectious bronchitis virus (IBV), was rescued (replicated and
packaged) using four heterologous strains of IBV as helper virus. Sequence
analysis of the genomic RNA from the four heterologous IBV strains (M41, H120,
HV10 and D207) identified nucleotide differences of up to 17% within the leader
sequence and up to 4.3% within the whole of the adjacent 5' untranslated region
(UTR). Analysis of the 5' ends of the rescued D-RNAs showed that the Beaudette
leader sequence, present on the initial CD-61, had been replaced with the
corresponding leader sequence from the helper IBV strain but the adjacent 5' UTR
sequence of the rescued D-RNAs corresponded to the original CD-61 Beaudette
sequence. These results demonstrated that the phenomenon of leader switching
previously identified for the coronaviruses murine hepatitis virus and bovine
coronavirus (BCoV) also occurred during the replication of IBV D-RNAs. Three
predicted stem-loop structures were identified within the 5' UTR of IBV. Stem
loop I showed a high degree of covariance amongst the IBV strains providing
phylogenetic evidence that this structure exists and is potentially involved in
replication, supporting previous observations that a BCoV stem-loop homologue was
essential for replication of BCoV defective interfering RNAs.
PMID- 10675418
TI - Molecular epidemiology of coxsackievirus B4 and disclosure of the correct
VP1/2A(pro) cleavage site: evidence for high genomic diversity and long-term
endemicity of distinct genotypes.
AB - Genetic diversity among 107 coxsackievirus B4 field isolates has been studied.
These isolates included clinical and environmental isolates originating from
Finland, the Netherlands and France, and also from several other countries,
including the USA. Three genomic regions were used for phylogenetic analyses: the
VP1/2A junction, the entire VP1 and the VP4/VP2 region. Alignment of the deduced
amino acid sequence in the VP1/2A junction revealed extensive sequence variation
at the previously proposed cleavage site. MS analysis of proteolytic fragments
from VP1 revealed that the exact cleavage site is situated between amino acid
residues Thr-849 and Gly-850. At least seven distinct genetic lineages, or
genotypes, had been circulating in Europe during the period 1959-1998. Two
genotypes were endemic in the Netherlands during most of the investigated period.
Genetically closely related strains could be found in different countries, and
different genotypes co-circulated at the same time in a given country. Clustering
patterns were identical in the three genomic intervals. In the VP4/VP2 region,
the intraserotypic variation approached interserotype variation. Sequence
comparisons of the entire VP1 gene gave a reliable genetic identification of
enterovirus serotype. It is suggested that, for genotype classification of
previously serotyped coxsackievirus B4 isolates, comparison of VP1/2A sequences
is sufficient, but for more detailed investigation of genetic relationships, and
for 'genetic serotyping', the entire VP1 gene should be used. The VP4/VP2 region
is less reliable for genetic serotyping and genotyping, although the primers are
able to amplify many different serotypes.
PMID- 10675419
TI - Biochemical characterization of salmon pancreas disease virus.
AB - Salmon pancreas disease virus (SPDV) has been shown to cause severe economic
losses in farmed Atlantic salmon (Salmo salar) and has been reported to occur in
Europe, Scandinavia and the United States. This paper describes the biochemical
characterization of SPDV in terms of its RNA and protein composition. SPDV was
purified by precipitation from infected Chinook salmon embryo (CHSE-214) cell
culture supernatant and sucrose density-gradient centrifugation. Fractions
containing virus were identified by an immunodot blot assay using an SPDV
specific MAb. Two major proteins with molecular masses of approximately 55 and 50
kDa, putatively identified as the E1 and E2 alphavirus glycoproteins
respectively, were detected when purified virus preparations were analysed by
PAGE. Radiolabelling experiments indicated that SPDV infection of CHSE-214 cells
did not shut-off host-cell protein synthesis, making attempts to identify virus
specific proteins unsuccessful. However, radioimmunoprecipitation assay (RIPA)
experiments showed that two SPDV-specific MAbs reacted with a protein in the 50
55 kDa range. Northern blot hybridization with cloned cDNA probes indicated that
infected cells contained RNA species of approximately 11.4 and 4 kb, which
correspond to the genomic and subgenomic RNAs specified by SPDV. The results
described are consistent with SPDV being characterized as an alphavirus.
PMID- 10675420
TI - The C-terminal domain of rotavirus NSP5 is essential for its multimerization,
hyperphosphorylation and interaction with NSP6.
AB - Rotavirus NSP5 is a non-structural phosphoprotein with putative autocatalytic
kinase activity, and is present in infected cells as various isoforms having
molecular masses of 26, 28 and 30-34 kDa. We have previously shown that NSP5
forms oligomers and interacts with NSP6 in yeast cells. Here we have mapped the
domains of NSP5 responsible for these associations. Deletion mutants of the
rotavirus YM NSP5 were constructed and assayed for their ability to interact with
full-length NSP5 and NSP6 using the yeast two-hybrid assay. The
homomultimerization domain was mapped to the 20 C-terminal aa of the protein,
which have a predicted alpha-helical structure. A deletion mutant lacking the 10
C-terminal aa (DeltaC10) failed to multimerize both in yeast cells and in an in
vitro affinity assay. When transiently expressed in MA104 cells, NSP5 became
hyperphosphorylated (30-34 kDa isoforms). In contrast, the DeltaC10 mutant
produced forms equivalent to the 26 and 28 kDa species, but was poorly
hyperphosphorylated, suggesting that multimerization is important for this
proposed activity of the protein. The interaction domain with NSP6 was found to
be present in the 35 C-terminal aa of NSP5, overlapping the multimerization
domain of the protein, and suggesting that NSP6 might have a regulatory role in
the self-association of NSP5. NSP6 was also found to interact with wild-type
NSP5, but not with its mutant DeltaC10, in cells transiently transfected with
plasmids encoding these proteins, confirming the relevance of the 10 C-terminal
aa for the formation of the heterocomplex.
PMID- 10675421
TI - Identification and differentiation of the nine African horse sickness virus
serotypes by RT-PCR amplification of the serotype-specific genome segment 2.
AB - This paper describes the first RT-PCR for discrimination of the nine African
horse sickness virus (AHSV) serotypes. Nine pairs of primers were designed, each
being specific for one AHSV serotype. The RT-PCR was sensitive and specific,
providing serotyping within 24 h. Perfect agreement was recorded between the RT
PCR and virus neutralization for a coded panel of 56 AHSV reference strains and
field isolates. Serotyping was achieved successfully with live and formalin
inactivated AHSVs, with isolates of virus after low and high passage through
either tissue culture or suckling mouse brain, with viruses isolated from widely
separated geographical areas and with viruses isolated up to 37 years apart.
Overall, this RT-PCR provides a rapid and reliable method for the identification
and differentiation of the nine AHSV serotypes, which is vital at the start of an
outbreak to enable the early selection of a vaccine to control the spread of
disease.
PMID- 10675422
TI - Subterminal viral DNA nucleotides as specific recognition signals for human
immunodeficiency virus type 1 and visna virus integrases under magnesium
dependent conditions.
AB - Many reports describe the characteristics of susceptible viral DNA substrates to
various retroviral integrases during in vitro reactions in which manganese serves
as the divalent cation cofactor for site-specific nicking. However, manganese is
known to alter the specificity of some endonucleases and magnesium may be the
divalent cation used during retroviral integration in vivo. To address these
concerns, we identified conditions under which the integrases of human
immunodeficiency virus type 1 and visna virus were optimally active with
magnesium (the first time such activity was shown for visna virus integrase) and
used these conditions to test the susceptibility of a series of
oligodeoxynucleotide substrates. The data show that two base pairs immediately
internal to the conserved CA dinucleotide near the termini of retroviral DNA are
selectively recognized by the two integrases and that the final six base pairs of
viral DNA contain sufficient sequence information for specific recognition and
cleavage by each enzyme. The results validate the importance of the subterminal
viral DNA positions even in the presence of magnesium and identify viral DNA
positions that functionally interact with integrase. The data obtained under
magnesium-dependent conditions, which were obtained with substrates containing
single and multiple base-pair substitutions and two different retroviral
integrases, are consistent with those previously obtained with manganese. Thus,
the large body of manganese-dependent data identifying terminal viral DNA
positions that are important in substrate recognition by various integrases
likely reflects interactions that are biologically relevant.
PMID- 10675423
TI - Molecular analysis of ovine prion protein identifies similarities between BSE and
an experimental isolate of natural scrapie, CH1641
PMID- 10675424
TI - The effect of weight loss in overweight, lactating women on the growth of their
infants.
AB - BACKGROUND: The retention of weight gained during pregnancy may contribute to
obesity. Lactation should promote weight loss, but weight loss is highly variable
among lactating women. The risks associated with the restriction of energy intake
during lactation have not been adequately evaluated. The purpose of this study
was to determine whether weight loss by women during lactation affects the growth
of their infants. METHODS: We randomly assigned 40 breast-feeding women who were
overweight (defined as a body-mass index [the weight in kilograms divided by the
square of the height in meters] of 25 to 30) at 4 weeks post partum either to
restrict their energy intake by 500 kcal per day and to exercise for 45 minutes
per day for 4 days per week (the diet-and-exercise group) or to maintain their
usual dietary intake and not exercise more than once per week for 10 weeks (the
control group). We measured the weight and fat mass of the women and the weight
and length of the infants before, during, and at the end of the study period.
RESULTS: The mean (+/-SD) energy intake decreased by 544+/-471 kcal per day in
the diet-and-exercise group. As compared with the control group, the women in the
diet-and-exercise group lost more weight (4.8+/-1.7 kg vs. 0.8+/-2.3 kg, P<0.001)
and fat mass (4.0+/-2.0 kg vs. 0.3+/-1.8 kg, P<0.001). The gains in weight and
length of the infants whose mothers were in the diet-and-exercise group (1925+/
500 g and 7.8+/-2.0 cm, respectively) were not significantly different from those
of the infants whose mothers were in the control group (1861+/-576 g and 7.3+/
1.7 cm). CONCLUSIONS: Weight loss of approximately 0.5 kg per week between 4 and
14 weeks post partum in overweight women who are exclusively breast-feeding does
not affect the growth of their infants.
PMID- 10675425
TI - Effect of exercise on coronary endothelial function in patients with coronary
artery disease.
AB - BACKGROUND: Studies of the cardioprotective effects of exercise training in
patients with coronary artery disease have yielded contradictory results.
Exercise training has been associated with improvement in myocardial perfusion
even in patients who have progression of coronary atherosclerosis. We therefore
conducted a prospective study of the effect of exercise training on endothelial
function in patients with coronary artery disease. METHODS: We randomly assigned
19 patients with coronary endothelial dysfunction, indicated by abnormal
acetylcholine-induced vasoconstriction, to an exercise-training group (10
patients) or a control group (9 patients). To reduce confounding, patients with
coronary risk factors that could be influenced by exercise training (such as
diabetes, hypertension, hypercholesterolemia, and smoking) were excluded. In an
initial study and after four weeks, the changes in vascular diameter in response
to the intracoronary infusion of increasing doses of acetylcholine (0.072, 0.72,
and 7.2 microg per minute) were assessed. The mean peak flow velocity was
measured by Doppler velocimetry, and the diameter of epicardial coronary vessels
was measured by quantitative coronary angiography. RESULTS: In the initial study,
the two groups had similar vasoconstrictive responses to acetylcholine. After
four weeks of exercise training, coronary-artery constriction in response to
acetylcholine at a dose of 7.2 microg per minute was reduced by 54 percent (from
a mean [+/-SE] decrease in the luminal diameter of 0.41+/-0.05 mm in the initial
study to a decrease of 0.19+/-0.07 mm at four weeks; P<0.05 for the comparison
with the change in the control group). In the exercise-training group, the
increases in mean peak flow velocity in response to 0.072, 0.72, and 7.2 microg
of acetylcholine per minute were 12+/-7, 36+/-11, and 78+/-16 percent,
respectively, in the initial study. After four weeks of exercise, the increases
in response to acetylcholine were 27+/-7, 73+/-19, and 142+/-28 percent (P<0.01
for the comparison with the control group). Coronary blood-flow reserve (the
ratio of the mean peak flow velocity after adenosine infusion to the resting
velocity) increased by 29 percent after four weeks of exercise (from 2.8+/-0.2 in
the initial study to 3.6+/-0.2 after four weeks; P<0.01 for the comparison with
the control group). CONCLUSIONS: Exercise training improves endothelium-dependent
vasodilatation both in epicardial coronary vessels and in resistance vessels in
patients with coronary artery disease.
PMID- 10675426
TI - A comparison of continuous thalamic stimulation and thalamotomy for suppression
of severe tremor.
AB - BACKGROUND: Deep-brain stimulation through an electrode implanted in the thalamus
was developed as an alternative to thalamotomy for the treatment of drug
resistant tremor. Stimulation is thought to be as effective as thalamotomy but to
have fewer complications. We examined the effects of these two procedures on the
functional abilities of patients with drug-resistant tremor due to Parkinson's
disease, essential tremor, or multiple sclerosis. METHODS: Sixty-eight patients
(45 with Parkinson's disease, 13 with essential tremor, and 10 with multiple
sclerosis) were randomly assigned to undergo thalamotomy or thalamic stimulation.
The primary outcome measure was the change in functional abilities six months
after surgery, as measured by the Frenchay Activities Index. Scores for this
index can range from 0 to 60, with higher scores indicating better function.
Secondary outcome measures were the severity of tremor, the number of adverse
effects, and patients' assessment of the outcome. RESULTS: Functional status
improved more in the thalamic-stimulation group than in the thalamotomy group, as
indicated by increases in the score for the Frenchay Activities Index (from 31.4
to 36.3 and from 32.0 to 32.5, respectively; difference between groups, 4.4
points; 95 percent confidence interval, 2.0 to 6.9). After adjustment for base
line characteristics, multivariate analysis also showed that the thalamic
stimulation group had greater improvement (difference between groups, 5.1 points;
95 percent confidence interval, 2.3 to 7.9). Tremor was suppressed completely or
almost completely in 27 of 34 patients in the thalamotomy group and in 30 of 33
patients in the thalamic-stimulation group. One patient in the thalamic
stimulation group died perioperatively after an intracerebral hemorrhage. With
the exception of this incident, thalamic stimulation was associated with
significantly fewer adverse effects than thalamotomy. Functional status was
reported as improved by 8 patients in the thalamotomy group, as compared with 18
patients in the thalamic-stimulation group (P=0.01). CONCLUSIONS: Thalamic
stimulation and thalamotomy are equally effective for the suppression of drug
resistant tremor, but thalamic stimulation has fewer adverse effects and results
in a greater improvement in function.
PMID- 10675427
TI - Low-dose nitric oxide therapy for persistent pulmonary hypertension of the
newborn. Clinical Inhaled Nitric Oxide Research Group.
AB - BACKGROUND: Inhaled nitric oxide improves gas exchange in neonates, but the
efficacy of low-dose inhaled nitric oxide in reducing the need for extracorporeal
membrane oxygenation has not been established. METHODS: We conducted a clinical
trial to determine whether low-dose inhaled nitric oxide would reduce the use of
extracorporeal membrane oxygenation in neonates with pulmonary hypertension who
were born after 34 weeks' gestation, were 4 days old or younger, required
assisted ventilation, and had hypoxemic respiratory failure as defined by an
oxygenation index of 25 or higher. The neonates who received nitric oxide were
treated with 20 ppm for a maximum of 24 hours, followed by 5 ppm for no more than
96 hours. The primary end point of the study was the use of extracorporeal
membrane oxygenation. RESULTS: Of 248 neonates enrolled, 126 were randomly
assigned to the nitric oxide group and 122 to the control group. Extracorporeal
membrane oxygenation was used in 78 neonates in the control group (64 percent)
and in 48 neonates in the nitric oxide group (38 percent) (P=0.001). The 30-day
mortality rate in the two groups was similar (8 percent in the control group and
7 percent in the nitric oxide group). Chronic lung disease developed less often
in neonates treated with nitric oxide than in those in the control group (7
percent vs. 20 percent, P=0.02). The efficacy of nitric oxide was independent of
the base-line oxygenation index and the primary pulmonary diagnosis. CONCLUSIONS:
Inhaled nitric oxide reduces the extent to which extracorporeal membrane
oxygenation is needed in neonates with hypoxemic respiratory failure and
pulmonary hypertension.
PMID- 10675428
TI - Images in clinical medicine. Cytomegalovirus esophageal ulcers.
PMID- 10675429
TI - Gas embolism.
PMID- 10675430
TI - Age-related macular degeneration.
PMID- 10675431
TI - Case records of the Massachusetts General Hospital. Weekly clinicopathological
exercises. Case 5-2000. A 35-year-old man with a painful abdominal mass and
fever.
PMID- 10675432
TI - Dieting and exercise in overweight, lactating women.
PMID- 10675433
TI - Exercise--toning up the endothelium?
PMID- 10675434
TI - New treatment options for tremors.
PMID- 10675436
TI - Correction: A Preliminary Study of Long-Term Treatment with Interferon Gamma-1b
and Low-Dose Prednisolone in Patients with Idiopathic Pulmonary Fibrosis.
PMID- 10675435
TI - Pharmacologic paralysis and withdrawal of mechanical ventilation at the end of
life.
PMID- 10675437
TI - Correction: A Comparison of Virtual and Conventional Colonoscopy for the
Detection of Colorectal Polyps.
PMID- 10675438
TI - Meeting of the Australian Microbeam Analysis Society, University of Sydney,
February 16-19, 1999: Introduction.
PMID- 10675439
TI - Radiofrequency Gaseous Detection Device.
AB - A radiofrequency gaseous detection device is proposed for use with instruments
employing charged particle beams, such as electron microscopes and ion beam
technologies, as well as for detection of ionizing radiations as in proportional
counters. An alternating (oscillating) electromagnetic field in the
radiofrequency range is applied in a gaseous environment of the instrument. Both
the frequency and amplitude of oscillation are adjustable. The electron or ion
beam interacts with a specimen and releases free electrons in the gas. Similarly,
an ionizing radiation source releases free electrons in the gas. The free
electrons are acted upon by the alternating electromagnetic field and undergo an
oscillatory motion resulting in multiple collisions with the gas molecules, or
atoms. At sufficiently low pressures, the oscillating electrons also collide with
surrounding walls. These processes result in an amplified electron signal and an
amplified photon signal in a controlled discharge. The amplified signals, which
are proportional to the initial number of free electrons, are collected by
suitable means for further processing and analysis.
PMID- 10675440
TI - Reverse Flow Pressure Limiting Aperture.
AB - The reverse flow pressure limiting aperture is a device that creates and sustains
a substantial gas pressure difference between two chambers connected via an
aperture. The aperture is surrounded by an annular orifice leading to a third
chamber. The third chamber is maintained at a relatively high pressure that
forces gas to flow through the annular aperture into the first of said two
chambers. The ensuing gas flow develops into a supersonic annular gas jet, the
core of which is coaxial with the central aperture. A pumping action is created
at the core of the jet and any gas molecules leaking through the aperture from
the second chamber are entrained and forced into the first chamber, thus creating
a substantial pressure difference between the first and second chamber.
PMID- 10675441
TI - Development of a System to Provide Full, Real-time Remote Control of a Scanning
Electron Microscope across the Second Generation Internet: The Teaching SEM.
AB - The development and makeup of a real-time full remote control system for the
University of Michigan, Department of Materials Science and Engineering Teaching
SEM is described. The instrument was initially controlled via the campus local
area Ethernet network and cable TV network. The latest implementation employs
Fast Ethernet, Asynchronous Transfer Mode (ATM) networks, and moving picture
experts group (MPEG) video encoding to effect the remote control via the computer
network alone. Remote control demonstrations from Washington, DC, Dearborn, MI,
and Emerson School, Ann Arbor, MI are described.
PMID- 10675442
TI - Fiber-optic Based Spectral Cathodoluminescence: Simple and Economic Option for
Use in Conventional and Environmental Scanning Electron Microscopy.
AB - A fiber-optic based spectral cathodoluminescence (CL) system has been
successfully installed on a variable pressure "environmental" scanning electron
microscope (ESEM). The fine size of the fiber (50 um) has been found to require
careful alignment. To provide this alignment, a simple X-Y translator has been
used. The aligned fiber exhibits high efficiency and the system has recorded
spectra at up to 3 million "counts" per sec on strongly cathodoluminescent doped
yttrium aluminium garnet (YAG) samples, at 30 kV and approximately 3 nA. A
resolution of 3 nm [full width half maximum (FWHM)] at 621 nm has been measured
from a red laser diode spectrum, on the ESEM column. A range of uncoated
materials has been measured to characterize the CL system; these materials ranged
from strongly luminescent YAG to weakly luminescent polymers. Well-characterized
doped zircons have also been investigated. These data suggest that the previously
reported intrinsic peak from zircon is a consequence of high-beam currents.
PMID- 10675443
TI - Correlation between Charge Contrast Imaging and the Distribution of Some Trace
Level Impurities in Gibbsite.
AB - Charge contrast images (CCI) of synthetic gibbsite obtained on an environmental
scanning electron microscope gives information on the crystallization process.
Furthermore, X-ray mapping of the same grains shows that impurities are localized
during the initial stages of growth and that the resulting composition images
have features similar to these observed in CCI. This suggests a possible
correlation between impurity distributions and the emission detected during CCI.
X-ray line profiles, simulating the spatial distribution of impurities derived
from the Monte Carlo program CASINO, have been compared with experimental line
profiles and give an estimate of the localization. The model suggests that a main
impurity, Ca, is depleted from the solution within approximately 3-4 um of
growth.
PMID- 10675444
TI - Quantitative Short-pulse Acoustic Microscopy and Application to Materials
Characterization.
AB - A new acoustic microscopy method was developed for providing near-surface elastic
property mapping of a material. This method has a number of advantages over the
traditional V(z) technique. First, it enables one to perform measurements in an
automated mode that only requires user intervention in the setup phase. This
automated mode makes it feasible to obtain quantitative microscopy images of the
elastic property over an area on the material being tested. Also, it only
requires a conventional ultrasonic system operating in pulsed mode for collecting
the data, rather than a specialized tone-burst system, which is needed in the
traditional quantitative scanning acoustic microscopy technique. Finally, unlike
the traditional method, the new experimental process does not require calibration
of the system's electronics or additional reference data taken under hard-to
duplicate identical conditions from a material that does not exhibit surface
acoustic waves.
PMID- 10675446
TI - News and Commentary.
PMID- 10675445
TI - Compression of Secondary Ion Microscopy Image Sets Using a Three-dimensional
Wavelet Transformation.
AB - This article proposes a lossy three-dimensional (3-D) image compression method
for 3-D secondary ion microscopy (SIMS) image sets that uses a separable
nonuniform 3-D wavelet transform. A typical 3-D SIMS measurement produces
relatively large amounts of data which has to be reduced for archivation
purposes. Although it is possible to compress an image set slice by slice, more
efficient compression can be achieved by exploring the correlation between
slices. Compared to different two-dimensional (2-D) image compression methods,
compression ratios of the 3-D wavelet method are about four times higher at a
comparable peak signal-to-noise ratio (PSNR).
PMID- 10675447
TI - Diagnosis of lateral hypopharyngeal pouches: a comparative study of
videofluorography and pseudovalsalva maneuver in double contrast pharyngography.
AB - BACKGROUND: To evaluate the difference between the pseudovalsalva maneuver in
double-contrast pharyngography and the videofluorographic swallowing examination
in the detection and grading of lateral hypopharyngeal pouches. METHODS: Two
hundred twenty-seven videofluorographic swallowing examinations and double
contrast pharyngography using the pseudovalsalva maneuver were retrospectively
analyzed by two radiologists. The mean age of the patients was 54 years (range =
21-81 years). The examination was performed on a fluoroscopy unit with a U-matic
videorecording system in standard projections. Iodinated contrast agent was used,
followed by barium if there was no massive aspiration. RESULTS: In contrast to
the videofluorographic swallowing examination, which showed 170 lateral
hypopharyngeal pouches (113 grade I, 39 grade II, 18 grade III) in 101 patients,
the pseudovalsalva maneuver showed 304 pouches (304 grade III) in 179 patients.
No videofluorographically diagnosed lateral hypopharyngeal pouches were missed by
the pseudovalsalva maneuver; 134 pouches in 78 patients diagnosed with
pseudovalsalva maneuver had no correlation videofluorographically. CONCLUSION:
Double-contrast pharyngography using the pseudovalsalva maneuver is not a
reliable method for the diagnosis of lateral hypopharyngeal pouches.
PMID- 10675448
TI - Esophagobronchial fistula following redo Nissen fundoplication.
AB - Gastrobronchial fistula is a rare complication of antireflux surgery, whereas
esophagobronchial fistula as a complication of Nissen fundoplication has, to the
best of our knowledge, not been reported previously. We report on a case of
esophagobronchial fistula in a patient with left subphrenic abscess following
redo Nissen fundoplication. Chest radiographs suggested an unresponsive pneumonia
of the left lower lobe. Computed tomography (CT) of the abdomen showed partial
consolidation of the left lower lobe and contrast filling of the left bronchial
tree from a left subphrenic abscess. CT diagnosis of fistula originating from the
region of fundoplication was confirmed by Gastrografin follow-through.
PMID- 10675449
TI - Heterotopic pancreas of the stomach: CT findings correlated with pathologic
findings in six patients.
AB - BACKGROUND: The purpose of this study was to characterize the computed
tomographic (CT) findings of heterotopic pancreas of the stomach. METHODS: CT
scans of six surgically proven cases of heterotopic pancreas of the stomach were
reviewed. Three were dynamic spiral CT scans, with both arterial dominant and
late phase scans. In other three, both unenhanced and contrast-enhanced scans
were obtained by using conventional techniques. Particular attention was given to
the enhancement of the heterotopic pancreas. Pathologic and surgical findings
were correlated with CT findings. RESULTS: The locations were in the gastric
antrum in five cases and in the mid-body in one. Size ranged from 1 cm to 3 cm
(mean = 2.1 cm). Three cases showed homogeneous, strong enhancement similar to
the pancreas and consisted mainly of pancreatic acini with the same histologic
features as the normal pancreas. Two cases showed poor enhancement and consisted
mainly of ducts and hypertrophied muscle; pancreatic acini were a minor
component. In one case appearing as a cystic lesion on CT, a pseudocyst was found
with many ducts and some nests of pancreatic acini. CONCLUSIONS: Heterotopic
pancreas of the stomach showed a diverse spectrum of CT findings. Good
understanding of these CT findings may be helpful in making a correct diagnosis.
PMID- 10675450
TI - Gastric adenoma with atypical appearance: findings on double-contrast barium
study with histopathologic correlation.
AB - BACKGROUND: To describe the radiologic findings of nonpolypoid gastric adenomas
and to correlate them with pathologic findings. METHODS: During a 9-year period,
we reviewed 49 pure gastric adenomas in 43 patients with positive radiologic
findings. Of these adenomas, seven with atypical polypoid appearance were
retrospectively included in the study. We reviewed these findings with double
contrast barium study and correlated them with the pathologic findings. RESULTS:
Of seven nonpolypoid adenomas, four were depressed and three were flat at
pathologic examination. All were diagnosed as early gastric carcinoma (five as
type IIc, one as type IIb, one as type IIa + IIc) in upper gastrointestinal
series. Three were located in the gastric angle, two in the lower body, and two
in the antrum. Size ranged from 10 mm to approximately 25 mm (mean = 15 mm). Six
lesions had nodular surface and five had convergency of the mucosal folds. A
shallow depressed area was seen in six lesions. CONCLUSIONS: A considerable
proportion of gastric adenomas presents as a depressed or flat lesion on double
contrast barium study because of histologic characteristics of decreased
subjacent mucosa. Because the nonpolypoid adenoma has a greater potentional for
malignancy, more precaution is needed during the follow-up of this uncommon
lesion.
PMID- 10675451
TI - Afferent loop syndrome presenting as enterolith after Billroth II subtotal
gastrectomy: a case report.
AB - We present a rare late-onset (after 24 years) complication of gastric surgery
with a combination of afferent loop syndrome associated with a large duodenal
stone. The patient, who had undergone Billroth II partial gastrectomy for benign
ulcer 24 years before, developed abdominal pain in the right upper quadrant,
associated with nausea, vomiting, and high grade fever. Abnormal laboratory
values included elevated liver function test, suggesting a pressure-related
phenomenon. Leukocytosis and a high level of platelets were also found. Only
computed tomography and endoscopy of the upper gastrointestinal tract confirmed
the diagnosis of a huge stone in the dilated duodenal afferent loop. To our
knowledge, a case like this has not been reported previously in the literature.
PMID- 10675452
TI - Spontaneously reduced midgut malrotation: CT diagnosis.
AB - Midgut malrotation is a relatively rare congenital malformation that arises from
an error of rotation and fixation of the midgut. We report a case of
spontaneously reduced duodenal malrotation diagnosed by computed tomography and
roentgenography after the ingestion of barium.
PMID- 10675453
TI - Percutaneous balloon dilatation for benign hepaticojejunostomy strictures.
AB - BACKGROUND: Percutaneous balloon dilatation of biliary tract strictures is
generally accepted as a safe and inexpensive procedure. The effectiveness in
selected groups of patients remains under discussion. The purpose of this study
was to evaluate the results of percutaneous balloon dilatation in patients with a
benign stricture of a hepaticojejunostomy. METHODS: Fifteen patients with a
benign stricture of a hepaticojejunostomy were examined between 1993 and July
1997. An ultrasound-guided percutaneous transhepatic cholangiography (PTC)
procedure was performed, followed by a balloon dilatation. Follow-up was
performed prospectively by outpatient visits and laboratory testing. RESULTS:
Percutaneous dilatation was successful in 14 patients. Three patients developed a
recurrence. In one of these patients, the procedure was repeated successfully.
Gastrointestinal bleeding occurred in one patient. The success rate for balloon
dilatation in this group of patients was 73% after a mean follow-up of 30 months.
When the procedure was repeated, the success rate was 80% after a mean follow-up
of 33 months. CONCLUSIONS: Percutaneous balloon dilatation for benign
hepaticojejunostomy strictures is feasible in the majority of patients and
produces acceptable medium-term to long-term results. Advantages are its minimal
invasive character and the fact that all options remain open in case of failure.
PMID- 10675454
TI - Primary ileal plasmacytoma arising in mixed low- and high-grade B-cell lymphoma
of mucosa-associated lymphoid tissue type.
AB - We report an extremely rare case of primary ileal plasmacytoma accompanied by
mixed low- and high-grade B-cell lymphoma of mucosa-associated lymphoid tissue
(MALT) type. The radiographic and macroscopic features of the tumor were
characterized by two constricting lesions in the ileum. Histologic examination of
the resected specimen showed that one constrictive lesion was plasmacytoma and
the other MALT lymphoma was low and high grade. The plasmacytoma seemed to have
differentiated from the MALT lymphoma.
PMID- 10675455
TI - Mesenteric panniculitis: sonographic findings.
AB - BACKGROUND: Mesenteric panniculitis (MP) is a relatively rare disease, and
sonographic (US) and color Doppler findings have been infrequently reported.
METHODS: We reviewed the clinical data and US and Doppler results of three cases
of MP to determine the role and limitations of these techniques. RESULTS: The
sole presenting clinical sign was a soft mass. On US the lesion was imaged as a
poorly margined echogenic mass with hypoechoic areas. Color Doppler US visualized
the nondeviated mesenteric vessels within the mass, which enabled us to perform a
safe guided biopsy. CONCLUSIONS: US is useful as an initial diagnostic tool, but
its results must be interpreted carefully. Color Doppler US is very useful in
demonstrating fine vessels and helps in performing a safe needle biopsy.
PMID- 10675456
TI - Altered flow dynamics of intravascular contrast material to the liver in superior
vena cava syndrome: CT findings.
AB - BACKGROUND: To evaluate the findings of altered flow dynamics in the livers of
patients with obstruction of superior vena cava (SVC) on helical computed
tomography (CT). METHODS: In six patients (age range = 28-80 years) with SVC
obstruction, CT findings were retrospectively reviewed to identify the abnormal
enhancement patterns of the liver and the relation with the extrahepatic
collateral vessels and hepatic vessels. RESULTS: Abnormal hepatic enhancement was
observed in the following four (A-D) portions: (A) anterior portion of segment IV
(n = 5), (B) subdiaphragmatic portion of the liver (n = 4), (C) posterior portion
of the right lobe (bare area; n = 1), and (D) lateral segment of the left lobe (n
= 2). Two major collateral pathways to the liver were demonstrated as follows: A
and D --> from the umbilical vein to the left portal vein, and B and C --> from
the subcapsular vein to the bare area of the liver or to the hepatic veins. On
helical CT, these collateral pathways were also clearly visualized. CONCLUSION:
When these abnormal enhancements of the liver on CT are recognized within the
liver, these findings indicate diversion of contrast material into collateral
pathways to the liver with SVC obstruction.
PMID- 10675457
TI - Detection of hepatocellular carcinoma and its metastases with various pulse
sequences using superparamagnetic iron oxide (SHU-555-A).
AB - BACKGROUND: To identify the most useful combinations of various pre- and
postcontrast magnetic resonance (MR) image sequences in detecting hepatocellular
carcinoma (HCC) and its intrahepatic metastases before and after injection of SHU
555-A. METHODS: Thirty-eight lesions in 16 patients were evaluated before and
after administration of SHU-555-A by using fast spin echo (FSE), gradient echo
(GRE), and echo planar (EP) imaging sequences using a 1.5-Tesla superconducting
MR system. The signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) of
the lesions, signal-to-noise ratios, and other parameters were calculated.
RESULTS: Tumors were better detected after injection of SHU-555-A on all pulse
sequences except on out-of-phase T1-weighted (T1W)-GRE sequences. Tumor
detectability was higher for precontrast EP imaging and T2*-weighted (T2*W)-GRE
sequences, whereas detectability at postcontrast was higher for T2*W-GRE, proton
density-weighted-FSE, and in-phase T1W-GRE sequences. The SIR and CNR at
precontrast were highest for EP imaging, and those at postcontrast were highest
for T2*W-GRE. CONCLUSION: SHU-555-A will increase the detectability of HCC and
its liver metastases. T1W- and T2*W-GRE sequences would be the sequences of
choice.
PMID- 10675458
TI - Comparison of in-phase and out-of-phase gradient recalled echo T1-weighted pulse
sequence for MR imaging of malignant liver masses following administration of
paramagnetic gadolinium-chelate.
AB - BACKGROUND: The purpose of this study was to compare the performance of in-phase
and out-of-phase gradient recalled echo (GRE) pulse sequences on paramagnetic
contrast-enhanced magnetic resonance (MR) imaging of malignant liver lesions.
METHODS: Fifty patients (27 women, 23 men; mean age = 50 +/- 27 years) with known
or suspected focal liver lesions, nine of whom had a fatty liver, were examined
at 1.5 T before and 60 min after injection of gadobenate dimeglumine at a dose of
0.05 or 0.1 mmol/kg using two GRE techniques: echo time of 2.3 ms (out-of-phase)
or 4.6 ms (in-phase). Liver signal-to-noise ratio (SNR) and lesion-liver contrast
to-noise ratio (CNR) were calculated. RESULTS: In patients with a nonfatty liver,
liver SNR increased from 26 +/- 9 to 41 +/- 17 on in-phase images and from 28 +/-
8 to 45 +/- 14 on out-of-phase images. In patients with a fatty liver, in-phase
images provided significantly higher (p < 0.01) liver SNR than did out-of-phase
images predose (34 +/- 8 on in-phase vs. 21 +/- 8 on out-of-phase) and postdose
(44 +/- 13 on in-phase vs. 33 +/- 14 on out-of-phase). In patients with a
nonfatty liver, lesion-liver CNR was similar on in-phase and out-of-phase images,
predose and postdose. In patients with fatty liver, lesion-liver CNR was
significantly (p < 0.01) lower on out-of-phase images on predose and postdose
images. CONCLUSION: In-phase GRE imaging is recommended for imaging focal liver
lesions on paramagnetic contrast-enhanced MR imaging in patients with fatty
infiltration of the liver.
PMID- 10675459
TI - Enhanced color flow images in small hepatocellular carcinoma.
AB - BACKGROUND: Features of enhanced color flow images in small hepatocellular
carcinoma (HCC) are not fully elucidated. The purpose of this study was to
clarify the characteristic vascular images in small HCC observed by enhanced
color Doppler. METHODS: Enhanced color Doppler using the contrast agent Levovist
was performed on 13 patients with HCC smaller than 30 mm. Enhanced color flow
appearance was compared with angiographic findings. Time-intensity changes after
injection of the contrast agent were analyzed in HCC nodules. RESULTS:
Significant improvement in the detection of color flow signals was obtained in
small HCC using Levovist, from 33% in precontrast to 92% in postcontrast (p <
0.005). Three patterns of enhanced color flow images, which were related to the
angiographic findings, were observed. The time-intensity curve was classified
into two types by "time to peak" and "time on plateau" and was associated with
the patterns of enhanced images. CONCLUSION: Enhanced color flow imaging promises
to be a useful method for evaluating tumor vascularity noninvasively and to
contribute to the elucidation of the hemodynamics in small HCC.
PMID- 10675460
TI - Evaluation of the intratumoral vasculature of hepatocellular carcinoma by power
doppler sonography: advantages and disadvantages versus conventional color
doppler sonography.
AB - BACKGROUND: To determine whether a difference exists in the relative ability of
power Doppler sonography and conventional color Doppler sonography to detect the
intratumoral vasculature of hepatocellular carcinoma based on lesion size and
location. METHODS: Sixty patients with 88 hepatocellular carcinoma lesions that
showed tumor staining on angiography and were enhanced on dynamic computed
tomography were evaluated. Power Doppler sonography and color Doppler sonography
were used to detect the intratumoral vasculature, and their sensitivity to blood
flow was evaluated. RESULTS: Power Doppler sonography showed a superior detection
rate for lesions smaller than 2 cm and located 4-8 cm from the abdominal surface
in the right hepatic lobe as compared with color Doppler sonography (p < 0.01).
Neither power Doppler sonography nor color Doppler sonography depicted the
intratumoral vasculature of lesions located more than 8 cm from the abdominal
surface (n = 14). Both color Doppler imagings exhibited a low detection rate for
lesions in the left hepatic lobe (n = 31, p < 0.01). CONCLUSIONS: Power Doppler
sonography should be applied in the evaluation of small or intermediate depth
lesions because it is more sensitive to these lesions than color Doppler
sonography, but it is not useful for left lobe and deep lesions.
PMID- 10675461
TI - Intratumoral steatosis in focal nodular hyperplasia coinciding with diffuse
hepatic steatosis: CT and MRI findings with histologic correlation.
AB - Focal nodular hyperplasia (FNH) is a benign tumorlike condition that is thought
to be a hyperplastic response to increased blood flow in an arterial malformation
rather than a true neoplasm. Radiologically, FNH usually shows typical findings
on unenhanced and enhanced computed tomography (CT) and magnetic resonance images
(MRI), with atypical features being the exception rather than the rule. We report
an unusual case of FNH with extensive fatty infiltration of the lesion
illustrated on CT and MRI and proven by histopathology.
PMID- 10675462
TI - Hepatic and splenic involvement in cat-scratch disease: imaging features.
AB - Hepatosplenic involvement in cat-scratch disease, probably underdiagnosed, is
characterized by multinodular lesions throughout the liver and spleen. Radiologic
features of ultrasound, computed tomography, and magnetic resonance imaging are
not specific. The key of the diagnosis relies on a history of cat or kitten
contact. A specific serological test can confirm the diagnosis without invasive
procedures such as biopsy.
PMID- 10675463
TI - Massive intrahepatic extramedullary hematopoiesis in myelofibrosis.
AB - We describe the sonographic (US) and computed tomographic appearances of a large,
solitary tumor in the liver produced by extramedullary hematopoiesis in an 82
year-old patient with agnogenic myeloid metaplasia. Confirmation of this
diagnosis was made by US-guided fine-needle aspiration biopsy.
PMID- 10675464
TI - Intrahepatic splenosis: imaging features.
AB - We report a patient who presented with asymptomatic focal liver lesions and in
whom a diagnosis of intrahepatic splenosis was made. This rare condition mostly
occurs in patients who previously underwent splenic trauma or surgery. Magnetic
resonance imaging (MRI) characteristics suggesting this diagnosis are described.
The lesions were mainly hypointense on T1- and hyperintense on T2-weighted
images. After administration of small iron oxide particles (SPIO-Endorem), the
lesions remained slightly hyperintense relative to the hypointense liver
parenchyma but showed a 50% loss in signal intensity. Knowledge of these MRI
characteristics may avoid the use of surgical interventions to arrive at the
correct diagnosis of these rare liver lesions.
PMID- 10675465
TI - Complications of "dropped" gallstones after laparoscopic cholecystectomy:
technical considerations and imaging findings.
AB - New laparoscopic techniques have revolutionized the practice of surgery.
Laparoscopic cholecystectomy has become one of the most commonly performed
surgeries worldwide. Although shorter hospital stays and patient comfort have
offered clear advantages over open cholecystectomy, the technique has resulted in
several specific complications, including bile duct injury and gallbladder
perforation. Although rarely clinically significant, intraperitoneal gallstone
spillage can cause abscess formation and adhesions. Although these patients can
present with a confusing clinical picture, their characteristic radiologic
features should be recognized. We present two cases of complicated
intraperitoneal gallstone spillage radiologically diagnosed and treated with
laparoscopic and interventional radiologic techniques.
PMID- 10675466
TI - Gallbladder carcinoma: color Doppler sonography.
AB - This study, based on color Doppler and pulsed Doppler sonographic results of 13
cases with gallbladder carcinoma, eight cases of adenomyomatosis, and eight cases
of tumefactive biliary sludge, shows that the presence or absence of blood flow
signals helps in the differentiation between gallbladder carcinoma and
tumefactive biliary sludge (84.6% sensitivity and 80.0% specificity). However,
color Doppler sonography is still not fully capable of distinguishing all
gallbladder carcinoma, and a further increase in Doppler sensitivity is mandatory
for this purpose. Visualization of high-velocity blood flow within the lesion
made gallbladder carcinoma more likely than benign tumor. In contrast, there was
no difference in the resistive index between gallbladder carcinoma,
adenomyomatosis, and normal subject groups, and the significance of the resistive
index is a subject of future study.
PMID- 10675467
TI - Heterotopic gastric mucosa in the gallbladder: sonographic and CT findings.
AB - We present computed tomographic (CT) and sonographic findings of heterotopic
gastric mucosa incidentally found in a 63-year-old male. CT showed a slightly
high density area in the gallbladder, which was intermediately enhanced early
after bolus injection of contrast medium. Ultrasonography showed an echogenic
sessile polyp. Histologically, the tumor consisted of gastric fundic glands
containing parietal cells and chief cells.
PMID- 10675468
TI - Serous and mucinous cystadenoma/cystadenocarcinoma of the pancreas.
AB - Twenty cases of cystic pancreatic neoplasms were examined over a 10-year period
by the Department of Radiology, University Hospital, Lund, Sweden. Four patients
had serous cystadenoma, seven had mucinous cystadenoma, and seven had mucinous
cystadenocarcinoma. One patient had a mucin-producing ductal carcinoma, and one
patient had a benign mucus cyst. The various types of tumor are illustrated, and
the difficulty in differentiating the subtypes is stressed.
PMID- 10675469
TI - Hyaline vascular-type Castleman disease: a rare cause of a hypervascular
retroperitoneal mass.
AB - We present the cross-sectional imaging and angiographic findings of hyaline
vascular-type Castleman disease located in the retroperitoneum. The diagnosis was
made postoperatively. This entity can simulate a malignant neoplasm. The
histologic subtypes and presentations of Castleman disease and the differential
diagnosis of retroperitoneal masses are discussed.
PMID- 10675470
TI - Paratesticular aggressive fibromatosis: CT findings.
AB - Aggressive fibromatoses commonly originate from the musculoskeletal system,
mesentery, and retroperitoneum. We report a case of aggressive fibromatosis
arising from the spermatic cord. On helical computed tomography, the lesion
appeared as a solid mass with well-defined borders in the scrotum and with
infiltrative features in the retroperitoneum.
PMID- 10675474
TI - Inhibition of malignant ascites and growth of human ovarian carcinoma by oral
administration of a potent inhibitor of the vascular endothelial growth factor
receptor tyrosine kinases.
AB - We determined whether inhibition of the catalytic tyrosine kinase activity of the
receptors for vascular endothelial growth factor/vascular permeability factor
(VEGF/VPF) inhibits the formation of malignant ascites and the progressive growth
of human ovarian carcinoma cells implanted into the peritoneal cavity of nude
mice. The novel protein tyrosine inhibitor PTK 787 was evaluated in two models of
human ovarian cancer: Hey-A8 cells, which express low levels of VEGF/VPF and grow
as solid tumor foci on the surface of peritoneal organs, and SKOV3 i.p.1 cells,
which express high levels of VEGF/VPF and grow as solid peritoneal tumors and
ascites. Treatment of nude mice by daily oral administration of 50 mg/kg PTK 787
was not effective against Hey-A8 tumors. In sharp contrast, it significantly
inhibited growth of SKOV3 i.p.1 cells and formation of ascites, significantly
increasing survival of mice with the implants. Tumor-induced vascular
hyperpermeability in the peritoneum of tumor-bearing mice was inhibited by PTK
787, which accounted for its inhibition of ascites formation. Our results suggest
that blockade of the VEGF/VPF receptor may be an efficient strategy to inhibit
formation of malignant ascites and growth of VEGF/VPF-dependent human ovarian
carcinomas.
PMID- 10675475
TI - DF3 expression in human gallbladder carcinoma: significance for lymphatic
invasion.
AB - DF3 (MUC 1) is a member of a family of high molecular weight glycoproteins.
Recent studies have demonstrated that DF3 is expressed in tumors of various human
organs, and may function as an anti-adhesion molecule that inhibits cell-to-cell
adhesion, inducing tumor metastasis. However, expression patterns of DF3 have not
yet been established in human gallbladder carcinomas. In this study, we examined
DF3 expression in human gallbladder adenocarcinoma and its clinicopathological
significance. DF3 immunoreactivity was detected not only in the cancer cells
(cytoplasmic type; 50.0%, 27/54) but also in the cancer stroma (stromal type;
46.3%, 25/54). According to TNM classification, 65.0% (26/40) of T2-4 gallbladder
cancers showed cytoplasmic DF3, while 7.1% (1/14) of the T1 cancers were
cytoplasmic DF3-positive (p<0.001). Stromal DF3 expression was detected in 62.5%
(25/40) and none (0/14) of the T2-4 and T1 cancers, respectively (p<0.001). Lymph
node metastasis was frequently found in the cytoplasmic DF3- and stromal DF3
positive gallbladder cancers (59.3% and 60.0%, respectively). These observations
suggested that DF3 expression plays important roles in cancer cell growth and
metastasis of human gallbladder adenocarcinomas.
PMID- 10675476
TI - Microdissection based comparative genomic hybridization analysis (micro-CGH) of
secondary acute myelogenous leukemias.
AB - Comparative genomic hybridization (CGH) is a well established technique in
molecular cytogenetics. However, leukemias, and especially secondary acute
myelogenous leukemias (sAML) are not very well analyzed by this technique, even
though such diseases are often characterized by complex karyotypic changes, not
resolvable by conventional cytogenetic banding analysis. This lack of CGH-studies
might be due to the fact, that in most cases bone marrow aspirate is too limited
to do DNA-extraction additionally to the cytogenetic analysis. To circumvent this
problem a new CGH technique has been applied to analyze 10 AML cases with complex
karyotypic changes. In each case 15 interphase nuclei of the harvested and fixed
bone marrow cell-suspension have been microdissected from the coverslip surface
and collected in a tube. Subsequently, DNA was amplified by DOP-PCR. With this
micro-CGH technique additional cytogenetic information from 10 highly aberrant
AML cases was obtained and confirmed by FISH on metaphase of the corresponding
AML case.
PMID- 10675477
TI - Relationship between p53 gene mutation and protein expression: clinical
significance in transitional cell carcinoma of the bladder.
AB - Although the mutated p53 gene has been postulated to induce immunohistochemically
detectable p53 protein, reports regarding the relationship between p53 mutation
and p53 protein expression have been contradictory. This study investigated the
relationship between p53 mutations and p53 expression and their clinical
significance for patients with transitional cell carcinoma of the bladder. Eighty
seven transitional cell carcinoma of the bladder were analyzed by
immunohistochemistry (IHC) for p53 nuclear accumulation, and the results compared
to mutations detected in the p53 gene evaluated by polymerase chain reaction
single-strand conformation polymorphism (SSCP) and DNA sequence analysis. By p53
IHC analysis, positive p53 staining was observed in 50 (57.5%) of the 87 tumors.
The specificity of IHC, defined as a percentage of IHC negative (<20%) tumors
among tumors without mutation, was 94.6%. Despite the good concordance between
p53 mutation and p53 protein expression (p<0.0001), 48.0% (24/50) of the tumors
showed p53 overexpression without mutation, and 2 (5.4%) tumors with mutation
showed no p53 immunoreactivity. Patients with higher grade (grade 3), stage
(stages pT2-4), and p53 mutations had a poorer prognosis by Kaplan-Meier survival
analysis. A Cox univariate analysis found that grading (hazard ratio 3.139;
p=0.002), staging (hazard ratio 3.832; p=0.0005) and p53 mutation (hazard ratio
2.498; p=0.013) were significant variables in these patients, but no variable was
independently associated with an increased survival of bladder carcinoma by
multivariate analysis. We found that a 20% cut-off level of p53 overexpression
showed the highest correlation with prognosis and p53 mutation, however, p53
overexpression and mutation were not superior to staging as prognostic markers.
These data suggest that careful assessment of the TNM staging system remains the
most reliable predictive indicator of survival for patients with transitional
cell carcinoma of the bladder.
PMID- 10675478
TI - Expression and mutation patterns of p53 in benign and malignant salivary gland
tumors.
AB - The expression and mutation patterns of p53 were studied in a series of 68 benign
pleomorphic adenomas and 237 malignant salivary gland tumors. p53 overexpression
(nuclear staining exceeding 10%) was detected in 20% of the malignant salivary
gland tumors, with the highest prevalence observed in polymorphous low grade
adenocarcinoma, squamous cell carcinoma, and carcinoma ex pleomorphic adenoma and
the lowest in adenoid cystic carcinoma and acinic cell carcinoma. In contrast,
none of the 68 benign pleomorphic adenomas had nuclear staining exceeding 10%.
SSCP and nucleotide sequence analysis of exons 4 to 9 of p53 in 19 malignant
tumors revealed 9 mutations in 7 tumors. Our findings indicate that p53 may be a
useful marker to help discriminate between benign and malignant salivary gland
tumors.
PMID- 10675479
TI - Identification of a novel subtype of H4-RET rearrangement in a thyroid papillary
carcinoma and lymph node metastasis.
AB - RET/PTC chimeric oncogenes are generated by the fusion of heterologous genes to
the RET tyrosine kinase encoding domain. These rearrangements are typical of
papillary thyroid carcinomas. RET/PTC1 is one of the most frequently found
RET/PTC version and, in all the cases so far reported, it is invariably generated
by the fusion of the first encoding exon of the H4 gene to the RET kinase
encoding domain. This results in the generation of an oncogenic protein
containing the first 101 residues of the H4 protein at the N-terminus. We report
the isolation of a novel subtype of H4-RET fusion, designated RET/PTC1L, from a
human papillary carcinoma of the thyroid and lymph node metastasis. At variance
with the classic one, this novel rearrangement generates a protein containing the
N-terminal 150 residues of H4. RET/PTC1L is able to transform NIH 3T3 cells; its
transforming ability, however, is 5-fold lower than that of the classic RET/PTC1
isoform. We propose that RET/PTC1L is a novel chimeric oncogene involved in
thyroid tumorigenesis; its low transforming ability may be one of the reasons
explaining the low frequency by which it is found in human thyroid carcinomas.
PMID- 10675480
TI - Missense mutation of the hMSH6 and p53 genes in sporadic urothelial transitional
cell carcinoma.
AB - Functional defects in DNA mismatch repair genes have been shown to be associated
mainly with hereditary human malignancies. We examined genomic DNA from 88
sporadic transitional cell carcinomas (TCCs) of the urinary tract for mutations
in hMSH6 gene by polymerase chain reaction and direct sequencing analysis.
Mutational status of p53 gene was also studied as a potential target of genetic
instability secondary to hMSH6 dysfunction. A total of 5 cases (5.7%: 5/88)
displayed hMSH6 mutations all consisted of transition and located in exon 4,
including three cases with missense mutation and two without change of
corresponding amino acid. These three tumors with hMSH6 missense mutation had no
microsatellite instability with five microsatellite markers tested. p53 gene
mutations were detected in 22 cases (25.0%: 22/88). No tumors with p53 mutation
had any hMSH6 missense mutations. Compared to the cases without hMSH6
alterations, the three patients with hMSH6 alterations had more frequent
additional primary cancer (P<0.05). These findings provide the first in vivo
evidence for the type of alterations and frequency of possible involvement of the
hMSH6 mutations in sporadic type urothelial TCCs.
PMID- 10675481
TI - Regulation of Bcl2 phosphorylation by stress response kinase pathway.
AB - The anticancer drugs affecting either microtubule polymerization or
depolymerization could trigger Bcl2 phosphorylation in mitotic phase of the cell
cycle. By systematic site directed mutagenesis studies, we have previously mapped
taxol induced phosphorylation sites to be Ser-70 and 87 residues of Bcl2 protein.
Interestingly, sequences surrounding both serine-70 and serine-87 residues
represent MAP kinase consensus motif. Since Bcl2 phosphorylation predominantly
occurs at site consensus to MAP kinase family members, we were interested to test
whether Erk2 or Jun kinase is involved in this pathway. Our in vitro studies
document that stress activated kinase, JNK1 is responsible for Bcl2
phosphorylation.
PMID- 10675482
TI - The K-ras gene regulates vascular endothelial growth factor gene expression in
non-small cell lung cancers.
AB - Tumor angiogenesis is an essential step for tumor cell growth, progression and
metastasis. Vascular endothelial growth factor (VEGF) is mitogen specific for
endothelial cells, and therefore is believed to play a key role in tumor
angiogenesis. However, the mechanisms underlying the regulation of VEGF
expression remain virtually unknown and the only major regulator of VEGF
expression has been reported to be hypoxia. Recently, it was reported that a
mutant p53 in#duced the expression of VEGF mRNA, and that wild-type p53 down
regulated endogenous VEGF mRNA levels. In contrast, it has also been reported
that mutant ras oncogenes were associated with the marked up-regulation of VEGF
in transformed epithelial cells. Based on these results, we performed a
retrospective study of the p53 and K-ras genes status and VEGF gene expression in
the tumor tissues from 181 patients with non-small cell lung cancer using SSCP,
sequencing, RT-PCR and immunohistochemical techniques. Forty-six carcinomas
(25.4%) were evaluated as having high VEGF expression, and 135 tumors (74.6%) had
low VEGF expression. Of the 181 primary NSCLC studied, 63 carcinomas (34.8%)
contained mutations of p53, whereas only 14 carcinomas (7.7%) had mutations of K
ras. There were no significant relationships between VEGF expression and p53
status or each mutant exon of p53. In contrast, a significant difference was
found between VEGF expression and K-ras status. Of the 14 tumors with mutant K
ras genes, 7 cases (50.0%) had high VEGF expression whereas only 39 of the 167
tumors with wild-type K-ras (23.4%) had high VEGF expression (p=0.0278). The mean
VEGF conservation rate for the 14 tumors with mutant K-ras genes was 0.77+/-0.58
and the rate of the 167 tumors with wild-type K-ras genes was 0.49+/-0.46 (p=0.
0350). Moreover, the overall survival rate of patients with high VEGF expression
was lower than patients with low VEGF expression (45.7% vs 60.7%, p=0.0419). On
the other hand, there was no significant difference in the overall survival rate
between patients with a mutant p53 and those with a wild-type p53; there was also
no difference in the overall survival between patients with a mutant K-ras and
those with a wild-type K-ras. The Cox regression model analysis indicated that
three variables, VEGF status, K-ras status and nodal status, were found to be
significant indicators for prognosis (p=0.0236, p=0.0172 and p<0.0001,
respectively). Our data suggest that a high expression of VEGF in lung cancer may
be associated with a poor prognosis. This may be a clue to improving lung cancer
diagnoses and therapies aimed at inhibiting tumor angiogenesis due to VEGF.
PMID- 10675483
TI - Activation of voltage-operated Ca2+-channels in human small cell lung carcinoma
by the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1
butanone.
AB - The nicotine-derived tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3
pyridyl)-1-butanone (NNK) induces lung cancer in all animal species tested and is
thought to contribute significantly to the high lung cancer burden associated
with smoking. NNK has recently been identified as a high affinity ligand for
neuronal nicotinic acetylcholine receptors comprised of alpha7 subunits (alpha7
nAChR), and expressed in human small cell lung carcinoma (SCLC). As agonist
binding to this receptor in mammalian cells often results in membrane
depolarization and activation of voltage-operated Ca2+-channels (VOCCs), we
hypothesized that NNK may exert similar effects in SCLC. Using flow cytometry to
monitor the influx of Ca2+, reverse transcription polymerase chain reaction (RT
PCR) to determine the expression of VOCC-specific messenger RNA, as well as
analysis of DNA synthesis or determination of cell number, our data demonstrate
that binding of NNK to the alpha7 nAChR in SCLC cells caused influx of Ca2+ via
VOCCs of the L-, N-, and P-type. In turn, this led to a significant increase in
DNA synthesis and cell number which was inhibited by a site-selective antagonist
for the alpha7 nAChR and by Ca2+-channel blockers of the L-, N-, or P-types of
VOCCs. Our findings suggest that the chronic activation of VOCC-mediated Ca2+
influx by NNK in smokers is an important event that may affect numerous Ca2+
dependent signal transduction pathways, thus contributing significantly to the
development of SCLC.
PMID- 10675484
TI - Mechanisms in the chemoprevention of colon cancer: modulation of protein kinase
C, tyrosine protein kinase and diacylglycerol kinase activities by 1,4
phenylenebis-(methylene)selenocyanate and impact of low-fat diet.
AB - Epidemiological and experimental studies suggest an inverse relationship between
the intake of dietary selenium and/or low fat-intake and colon cancer risk.
Efficacy studies in rodents suggest that the organoselenium compound 1, 4
phenylenebis(methylene)selenocyanate (p-XSC), is a more effective and less toxic
chemopreventive agent than other organic or inorganic selenium compounds such as
selenomethionine and Na2SeO3. The efficacy of p-XSC against colon cancer is
significantly augmented by a low-fat diet. To explore the mechanisms by which
this combined inhibiting effect against colon carcinogenesis comes about, we have
investigated protein kinase C (PKC), tyrosine protein kinase (TPK),
diacylglycerol kinase (DGK) activities and 8-isoprostane levels in colonic mucosa
and tumor tissues in an azoxymethane (AOM)-induced rat colon cancer model.
Weanling male F344 rats were fed the semipurified AIN-76A diet until seven weeks
of age. Then various experimental groups were fed the low- or high-fat diets
containing 0 or 20 ppm p-XSC (10 ppm as selenium). At seven weeks of age, groups
of rats were injected s.c. with azoxymethane (AOM; 15 mg/kg body wt., once weekly
for 2 weeks) and continued on their respective experimental diets until 38 weeks
after the second AOM treatment. They were then sacrificed and colonic mucosal and
tumor samples were evaluated for PKC, TPK, DGK and 8-isoprostane levels.
Administration of p-XSC along with a low-fat diet significantly inhibited Ca+2
dependent and -independent PKC (P<0.05-0.01) activities in colonic mucosa and
tumors. Administration of p-XSC either low-fat or high-fat diet significantly
suppressed both colonic mucosal and tumor TPK activity (P<0.05-0.01). Suppression
of TPK activity was more pronounced in rats maintained on a low-fat diet
containing p-XSC. In contrast, rats receiving p-XSC with either low- or high fat
diet showed significantly increased DGK activity (P<0.01-0.0001). Rats fed low
fat or high-fat plus p-XSC had lower-levels of 8-isoprostane in the colonic
tumors than animals who had been given low- or high-fat diets without the
organoselenium compound. Interestingly, 8-isoprostane levels were lower in the
colon tumors of the rats fed the low-fat diet than those fed the high-fat diet.
Our findings suggest that p-XSC induced down-regulation of PKC and TPK activities
and up-regulation of DGK activity. These events may in part be responsible for
the chemopreventive activity against colon carcinogenesis. Further, this study
implies that p-XSC with a low-fat dietary regimen will augment regulation of PKC,
TPK and DGK activities in the colon.
PMID- 10675485
TI - Association of renal cell carcinoma antigen, disialylgalactosylgloboside, with c
Src and Rho A in clustered domains at the surface membrane.
AB - Disialylgalactosylgloboside (DSGG), defined by monoclonal antibody RM2, is a
renal cell carcinoma (RCC)-associated antigen which mediates adhesion of RCC TOS
1 cells to certain lung tissue target cells. This adhesion process may initiate
preferential lung metastasis of RCC. Ganglioside GM3 is a B16 melanoma-associated
antigen which similarly adheres to target cells and promotes consequent
metastasis. In view of the close association of GM3-enriched microdomain with
transducer molecules c-Src, Rho A, and FAK in B16 cells, we investigated the
organizational status of DSGG in RCC cell line TOS-1, with the following results:
i) DSGG, but not monosialylgalactosylgloboside, showed extensive clustering at
the TOS-1 cell surface; ii) a low-density membrane fraction isolated from TOS-1
cells contained >95% of cellular DSGG, although protein content in this fraction
was <1% of total cellular protein; iii) this fraction contained c-Src, Rho A, and
FAK, but not H-Ras; iv) c-Src and Rho A were co-immunoprecipitated with DSGG
through anti-DSGG mAb RM2 (IgM) affixed to a column. These observations indicate
that DSGG is clustered in RCC, as typified by TOS-1 cells, to form a microdomain
in which it is closely associated with c-Src, Rho A, and FAK, and may constitute
a functional unit as has been observed for GM3 with transducer molecules in B16
cells. The functional organization of such units may be essential in determining
malignant properties of RCC cells.
PMID- 10675486
TI - Alteration of the CDKN2/p16 gene is not required for HPV-positive uterine
cervical cancer cell lines.
AB - To determine whether alterations of the CDKN2/p16 might be involved in HPV
positive cervical cancers, we examined for alterations of this gene and function
of the protein p16 to interact with CDK4 in 5 cervical cancer cell lines. No
alteration of this gene was detected. Proteins for p16 and CDK4 were normally
expressed and function of p16 to interact with CDK4 was not abrogated in these
cell lines. These cell lines were human papillomavirus (HPV)-positive and carried
wild-type p53. These findings suggest that phosphorylation of pRb by CDK4 is not
critical in the carcinogenesis or in the establishment of HPV-positive cervical
cancer cell lines, since HPV E6 or E7 viral-transforming proteins inactivate p53
and pRb tumor suppressor protein function, resulting in deregulated progression
of the cell cycle.
PMID- 10675487
TI - Infrequent widespread microsatellite instability in hepatocellular carcinomas.
AB - Widespread or high-frequency microsatellite instability (MSI) due to the
defective DNA mismatch repair (MMR) occurs in the majority of hereditary non
polyposis colorectal cancer and a subset of sporadic malignant tumors. The
incidence of MSI and underlying DNA MMR defects have been well characterized in
gastrointestinal carcinogenesis, but not in hepatocarcinogenesis. To address the
issue, we analyzed 55 Japanese hepatocellular carcinomas using several indicators
of DNA MMR defects, such as microsatellite analysis, loss of heterozygosity (LOH)
and mutation analysis of MMR genes, methylation of hMLH1 promoter, and frameshift
mutations of mononucleotide repeat sequences within possible target genes.
Mutation of beta2-microglobulin gene, which is presumably involved in MSI
positive tumor cell escape from immune surveillance was also examined. Some of
these analyses were also carried out in 9 human liver cancer cell lines. None of
the 3 quasi-monomorphic mononucleotide markers sensitive for MSI, BAT26, BAT25,
and BAT34C4 presented shortened unstable alleles in any of the carcinoma,
cirrhosis, chronic hepatitis tissues, or cell lines. LOH at MMR genes was
infrequent (4.4 approximately 7.1%), and no mutations were detected. Neither
hMLH1 hypermethylation nor frameshift mutation in the target genes was detected.
No mutations were found in beta2-microglobulin. Widespread MSI due to the
defective DNA MMR appears to play little if any part in Japanese
hepatocarcinogenesis.
PMID- 10675488
TI - Analysis of glycoproteins in cancers and normal tissues reactive with monoclonal
antibodies B3 and B1.
AB - In this study we show by immunoblotting that B1 and B3, two newly isolated
monoclonal antibodies, react with a variety of glycoproteins with different
molecular weights expressed in stomach, pancreas, colorectal and breast cancers.
The pattern of reactivity differed among cancers arising in different tissues,
although no correlation has been observed with the histopathological
characteristics of the lesion analysed. MAb B3 and MAb B1, have a limited
reactivity with peritumoral tissues, whereas react very strongly with metastatic
lesion. Because of the limited reactivity of these antibodies with normal tissue,
MAbs B3 and B1, armed with toxin in the form of recombinant immunotoxins, can be
useful in treating certain kinds of cancer such as metastatic lesions. However,
until current clinical trials are completed, we will not know if they will be
helpful in cancer treatment.
PMID- 10675489
TI - Comparison of two human ovarian carcinoma cell lines (A2780/CP70 and MCAS) that
are equally resistant to platinum, but differ at codon 118 of the ERCC1 gene.
AB - ERCC1 is an essential gene within the nucleotide excision repair process. We
studied two human ovarian carcinoma cell lines for cisplatin resistance, which
differed with respect to ERCC1. The A2780/CP70 cell line has been extensively
studied previously, and has the wild-type ERCC1 sequence. The MCAS cell line has
a recently described ERCC1 polymorphism at codon 118, which is associated with an
approximate 50% reduction in codon usage. These cells did not differ with respect
to p53 sequence nor p53 mRNA induction following cisplatin exposure. The
induction of ERCC1 mRNA was markedly reduced in MCAS cells as compared to
A2780/CP70 cells. At the IC50 cisplatin dose for each cell line, MCAS cells were
less proficient at cisplatin-DNA adduct repair than A2780/CP70 cells. In absolute
terms, A2780/CP70 cells repaired 3-fold as much adduct (2.7 pg/microgram DNA over
6 h vs 0.86 pg/microgram DNA); and when expressed in terms of the maximal DNA
adduct load, A2780/CP70 cells repaired 50% more adduct than MCAS cells. MCAS
cells had increased cytosolic inactivation of drug at the IC50 dose level, which
has been previously suggested to be a compensatory cellular response for reduced
DNA repair capacity. These data suggest the possibility that this specific ERCC1
polymorphism, may be associated with reduced DNA repair capacity in human ovarian
cancer cells. This association may be effected through a reduction in peak
production of ERCC1 mRNA, and a consequent reduction in the translation of ERCC1
mRNA into protein.
PMID- 10675490
TI - Downregulation of the p53 tumor suppressor gene and upregulation of the bcl-2
gene in retinoic acid receptor alpha-deficient transgenic mice.
AB - We recently demonstrated lymphoma development in transgenic mice deficient in
retinoic acid receptor alpha (RARalpha). High incidence of lymphoma development
in this transgenic mouse model system was similar to lymphoma development in p53
knockout mice. In an effort to understand the molecular basis of lymphomagenesis
in RARalpha-deficient transgenic mice, we compared the levels of RARalpha to the
levels of p53 mRNA, and Bcl-2, and Bax proteins in lymphoid and non-lymphoid
tissues and in lymphomas derived from the RARalpha-deficient transgenic mice. The
p53 mRNA levels were depleted in various tissues including spleen ( approximately
96%), thymus ( approximately 29%) and bone marrow ( approximately 62%) of
RARalpha-deficient transgenic mice when compared with the normal littermates, and
the reduction in p53 mRNA expression in the various tissues examined was
proportional to the reduction in RARalpha expression. Bcl-2 to Bax ratios were
highly increased in the lymphoid compartments (spleen >bone marrow >thymus)
because of selective overexpression of Bcl-2 protein. In summary, RARalpha
downmodulation in this transgenic mouse model system was accompanied by p53
downmodulation and deregulation of Bcl-2 to Bax ratios in the lymphoid
compartments.
PMID- 10675491
TI - Major oncogenes and tumor suppressor genes involved in epithelial ovarian cancer
(review).
AB - Ovarian cancer remains the leading cause of death from gynecologic malignancy in
Western countries. This cancer results from a succession of genetic alterations
involving oncogenes and tumor suppressor genes which have a critical role in
normal cell growth regulation. Mutations and/or overexpression of three
oncogenes, HER-2/neu, c-myc and K-ras, and of the tumor suppressor gene p53, have
frequently been observed in sporadic ovarian cancer. In the context of high risk
families, the most frequently involved genes are BRCA1 and BRCA2. We review the
function of these different proteins, the incidence of mutations in their genes
in carcinogenesis and as potential prognostic factors in sporadic and hereditary
ovarian cancer.
PMID- 10675492
TI - Autocrine secreted insulin-like growth factor-I stimulates MAP kinase-dependent
mitogenic effects in human primitive neuroectodermal tumor/medulloblastoma.
AB - Primitive neuroectodermal tumors/medulloblastoma (PNET/MB) have similarities to
neuroectodermal progenitor cells of the developing CNS. Since insulin-like growth
factor I (IGF-I) exerts pleiotrophic effects on cells in the developing CNS, we
evaluated the production, mitogenic effects and signaling pathways of IGF-I in
PNET/MB cells and found that IGF-I is an autocrine growth factor in human PNET/MB
cell lines tested. Stimulation of DAOY cells by IGF-I led to phosphorylation of
its cognate receptor (IGF-IR) and resulted in cell proliferation. These effects
of IGF-I were suppressed by IGF-IR blocking antibodies and by PD 98059, MAP
kinase pathway inhibitor. The results demonstrate the existence of an autocrine
IGF-I/IGF-IR loop and indicate that IGF-I promotes proliferation via MAP kinase
pathway.
PMID- 10675493
TI - The p16INK4alpha/p19ARF gene mutations are infrequent and are mutually exclusive
to p53 mutations in Indian oral squamous cell carcinomas.
AB - Eighty-seven untreated primary oral squamous cell carcinomas (SCCs) associated
with betel quid and tobacco chewing from Indian patients were analysed for the
presence of mutations in the commonly shared exon 2 of p16INK4alpha/p19ARF genes.
Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and
sequencing analysis were used to detect mutations. SSCP analysis indicated that
only 9% (8/87) of the tumours had mutation in p16INK4alpha/p19ARF genes. Seventy
two tumours studied here were previously analysed for p53 mutations and 21%
(15/72) of them were found to have mutations in p53 gene. Only one tumour was
found to have mutation at both p53 and p16INK4alpha/p19ARF genes. Thus, the
mutation rates observed were 21% for p53, 9% for p16INK4alpha/p19ARF, and 1% for
both. Sequencing analysis revealed two types of mutations; i) G to C (GCAG to
CCAG) transversion type mutation at intron 1-exon 2 splice junction and ii)
another C to T transition type mutation resulting in CGA to TGA changing arginine
to a termination codon at p16INK4alpha gene codon 80 and the same mutation will
alter codon 94 of p19ARF gene from CCG to CTG (proline to leucine). These results
suggest that p16INK4alpha/p19ARF mutations are less frequent than p53 mutations
in Indian oral SCCs. The p53 and p16INK4alpha/p19ARF mutational events are
independent and are mutually exclusive suggesting that mutational inactivation of
either p53 or p16INK4alpha/p19ARF may alleviate the need for the inactivation of
the other gene.
PMID- 10675494
TI - Both HPV and carcinogen contribute to the development of resistance to apoptosis
during oral carcinogenesis.
AB - Oral carcinomas frequently contain human papilloma virus (HPV)-16/18. As p53 is
degraded through interaction with HPV-16/18 products (E6/E7), p53 dysfunction may
contribute to oral carcinogenesis. Furthermore, epidemiological studies suggest
that smoking history may be critical for oral carcinogenesis. To delineate the
involvement of HPV-16 infection and carcinogen in oral carcinogenesis, Park et al
have established a multistep oral carcinogenesis model. Overexpression of p53
altered the expression of Fas antigen (Fas-R), Bax and Bcl-2; however, it remains
unclear how the loss of p53 modifies the expression of these molecules. Using the
multistep oral carcinogenesis model, we analyzed how the loss of p53 and
carcinogen modified the expression of these molecules and their role in the
development of resistance to apoptosis of oral carcinomas. The HOK-16B cell line
was immortalized by HPV-16 transfection of normal human oral keratinocytes
(NHOK). HOK-16B-BaP and HOK-16B-BaP-T1 were established from HOK-16B following
short-term and long-term stimulation with the chemical carcinogen,
benzo(a)pyrene, respectively. The malignant phenotype develops in sequence from
HOK-16B, HOK-16B-BaP and HOK-16B-BaP-T1. The expression of apoptosis-related
molecules was examined by Western blot analysis or by flow cytometry. Fas
mediated cytotoxicity was assessed using CH-11, an agonistic anti-Fas-R IgM
monoclonal antibody. The apoptosis-related molecules examined were the Fas-R, Bcl
2, Bax, and Fas-associated phosphatase 1 (FAP-1). Downregulation of Fas-R and
upregulation of Bcl-2 in HOK-16B-BaP were observed in HOK-16B-BaP and HOK-16B
BaPT1. Bax was downregulated in HOK-16B, HOK-16B-BaP and HOK-16B-BaP-T1. The
expression of FAP-1 was increased with progression towards malignancy. NHOK and
HOK-16B were relatively sensitive to CH-11, whereas HOK-BaP and HOK-BaP-T1 were
resistant to CH-11. Treatment of HOK-16B-BaP with antisense bcl-2 oligonucleotide
rendered the cells more sensitive to CH-11-induced apoptosis. These data
demonstrate that both the loss of p53 and carcinogen stimulation are associated
with altered expression of Fas-R, Bcl-2 and FAP-1, although the loss of p53 is
sufficient for altered expression of Bax. Thus, both HPV infection and smoking
contribute to acquisition of anti-apoptotic characteristics by oral carcinomas.
PMID- 10675495
TI - Transforming growth factor-beta and response to anticancer therapies in human
liver and gastric tumors in vitro and in vivo.
AB - Liver cancer and gastric cancer are the most common solid tumors worldwide.
Transforming growth factor-beta (TGF-beta) production and lack of response to TGF
beta growth inhibitory effects have been associated with tumor progression and
therapeutic resistance. HepG2, Hep3B, and SK-HEP-1 human liver cancer lines
produce 3, 5.7, and 2.5 ng TGF-beta1; 1.4, 2, and 4 ng TGF-beta2 and 0.15, 0.2
and 0.22 ng TGF-beta3 per 107 cells (24 h). Expression of the TGF-beta type I
receptor is 20x, 1x, and 0.6x the level in mink lung MvLu1 cells in the HepG2,
Hep3B, and SK-HEP-1 cells, respectively. HepG2 and Hep3B cells do not express the
TGF-beta type II receptor while SK-HEP-1 cells express 7x the level found in mink
lung MvLu1 cells. Hs 746T, KATO III, RF-1, and RF-48 human gastric cancer cell
lines produce 12. 5, 0.35, 0.4, and 0.4 ng TGF-beta1; 2.6, 0.95, 0.5, and 0.52 ng
TGF-beta2 and 0.42, 0.17, 0.12, and 0.14 ng TGF-beta3 per 107 cells (24 h).
Expression of TGF-beta type I receptor is 0.7x, 0.7x, 0.8x, 0.6x the level in
mink lung MvLu1 cells in the Hs 746T, KATO III, RF-1 and RF-48 cells,
respectively. KATO III cells are lacking in the TGF-beta type II receptor while
Hs 746T, RF-1 and RF-48 cells express 10x, 0.8x, and 1x the levels in mink lung
MvLu1 cells. The IC50 for TGF-beta1 is >>10 ng/ml in all of these lines except RF
48 where TGF-beta1 is mitogenic. The response of the cell lines to radiation,
doxorubicin, mitomycin C, cisplatin, 5-fluorouracil, methotrexate, and
gemcitabine showed that SK-HEP-1 was the most drug resistant liver cancer cell
line and KATO III was the most drug resistant gastric cancer cell line. Overall,
there was no correlation between TGF-beta secretion in cell culture and
sensitivity of the cells to anticancer agents. Increased TGF-beta1 levels were
detectable in the plasma of nude mice bearing Hep3B and Hs 746T xenografts. Those
tumors which secreted greater amounts of TGF-beta were more therapeutically
resistant in vivo.
PMID- 10675496
TI - Radiotherapy for carcinoma of the posterior pharyngeal wall.
AB - Posterior pharyngeal carcinoma has an extremely poor prognosis regardless of the
method of treatment. The purpose of this study was to assess the local control
and survival in patients with carcinoma of the posterior pharyngeal wall treated
with definitive radiotherapy and to determine prognostic factors which may be
relevant to the current UICC staging classification. Between January 1991 and
December 1995, 22 patients with a mean age of 60 years (range 44-82) received
definitive radiotherapy, using a homogeneous technique, for carcinoma of the
posterior pharyngeal wall. The median follow-up was 42 months (range 25-66). The
overall 3-year survival and local control for the whole group was 50% and 73%
respectively. Patients with early stage (T1 and T2) disease had a significantly
better overall 3-year survival rate of 77% compared to 11% for patients with
advanced stage (T3 and T4) disease (p=0.0010). Similarly, patients with early
stage disease had a significantly improved 3-year local control rate compared to
patients with more advanced stage disease (92% and 44% respectively, p=0.0080).
Patients with node positive disease had an inferior survival rate of 29% compared
to 60% for those with node negative disease though the difference did not reach
statistical significance. In addition only one patient with initial node negative
disease had isolated nodal relapse. There was no significant late morbidity. For
patients with early stage disease we have obtained local control and survival
rates comparable to other groups with a once daily, short fractionation
radiotherapy scheme but with reduced morbidity. In late stage disease altered
fractionation schemes should be considered in order to achieve better local
control and survival. Isolated nodal relapse was not a significant problem in
this cohort of patients. Outcome correlates with primary tumour size and this is
reflected in the current UICC staging classification.
PMID- 10675497
TI - Mechanical deformation induces proliferation of human colorectal carcinoma cells.
AB - The cell biology of intravascular tumor cells is clinically important but the
many important variables of this environment have proved difficult to model. We
studied the effects of repetitive mechanical deformation, a phenomenon affecting
all intravascular cells, on human colon cancer cell line HCT 116 in vitro. Cell
proliferation, assessed by [3H]-thymidine incorporation and cell count, increased
by about 30% at two days in cells subjected to deformation at 30 cycles/min as
compared to controls; levels of the nuclear proliferation antigen detected by
monoclonal antibody MIB-1 were also increased. Deformation increased transforming
growth factor beta1 (TGF-beta1) and plasminogen activator inhibitor-1 gene
expression sevenfold at two days, but mannose-6-phosphate did not affect cell
proliferation, indicating that endogenous TGF-beta is not involved in the
proliferative response. HCT 116 cells lack TGF-beta type II receptors, but stable
transfection of TGF-beta type II receptor cDNA did not alter the cellular
response to mechanical deformation, as assessed by cell proliferation,
morphology, or gene expression. Mechanical deformation affects several important
aspects of HCT 116 cell biology, suggesting that the intravascular environment
may regulate tumor cell biology in general. Endogenous TGF-beta and TGF-beta
receptor-mediated signaling are not responsible for the deformation-induced
proliferative response in HCT 116.
PMID- 10675498
TI - Detection of telomerase activity in human carcinomas using a trap-ELISA method:
correlation with hTR and hTERT expression.
AB - We have evaluated telomerase activity in a tumour population of 65 human cancers
by using a TRAP-based method, in which detection is performed by an enzyme
immunoassay (ELISA). We have corroborated that sensitivity and specificity of
this new procedure can be considered similar to that of classical TRAP method,
having the advantage of a rapid and reproducible analysis of large pools of
samples. Thus, telomerase activity was detected in 83% of the tumours included in
our population. Moreover, we found a significant association between enzyme
activity and both hTR and hTERT expression (P=0.004 and P=0.04, respectively).
PMID- 10675499
TI - Mechanism of hepatocellular uptake of albumin-bound bilirubin.
AB - We previously demonstrated that unconjugated bilirubin spontaneously diffuses
through phospholipid bilayers at a rate which exceeds albumin dissociation,
suggesting that solvation from albumin represents the rate-limiting step in
hepatic bilirubin clearance. To further examine this hypothesis, we studied the
uptake of bovine serum albumin (BSA)-bound bilirubin by cultured hepatoblastoma
(HepG2) cells. Uptake of bilirubin was saturable, with a K(m) and V(max) of 4.2+/
0.5 microM (+/-S.E.M.) and 469+/-41 pmol min(-1) mg(-1) at 25 degrees C.
Substantial bilirubin uptake also was observed at 4 degrees C (K(m)=7.0+/-0.8
microM, V(max)=282+/-26 pmol min(-1) mg(-1)), supporting a diffusional transport
mechanism. Consistent with reported solvation rates, the cellular uptake of
bilirubin bound to human serum albumin was more rapid than for BSA-bound
bilirubin, indicative of dissociation-limited uptake. Counterintuitively, an
inverse correlation between pH and the rate of bilirubin flip-flop was observed,
due to pH effects on the rate of dissociation of bilirubin from albumin and from
the membrane bilayer. The identification of an inflection point at pH 8.1 is
indicative of a pK(a) value for bilirubin in this range. Taken together, our data
suggest that hepatocellular uptake of bilirubin is dissociation-limited and
occurs principally by a mechanism involving spontaneous transmembrane diffusion.
PMID- 10675500
TI - Effects of the hinge region of cecropin A(1-8)-magainin 2(1-12), a synthetic
antimicrobial peptide, on liposomes, bacterial and tumor cells.
AB - A 20-residue hybrid peptide (CA(1-8)-MA(1-12): KWKLFKKIGIGKFLHSAKKF-NH(2))
incorporating 1-8 residues of cecropin A (CA) and 1-12 residues of magainin 2
(MA) has potent antibiotic activity without hemolytic activity. In order to
investigate the effects of the flexible hinge sequence, Gly-Ile-Gly of CA(1-8)
MA(1-12) (CA-MA) on antibiotic activity, CA-MA and its three analogues, CA-MA1,
CA-MA2 and CA-MA3 were synthesized. The Gly-Ile-Gly sequence of CA-MA was deleted
in CA-MA1 and replaced with Pro and Gly-Pro-Gly in CA-MA2 and CA-MA3,
respectively. CA-MA1 and CA-MA3 caused a significant decrease in the bactericidal
rate against Escherichia coli and Bacillus subtilis and the tumoricidal activity
against four different tumor cells, and the PC/PS (4:1, w/w) vesicle-aggregating
and disrupting activities. However, CA-MA2 showed a similar bactericidal rate and
antitumor, vesicle-aggregating and disrupting activities, as compared with CA-MA.
These results suggested that the flexibility or beta-turn induced by Gly-Ile-Gly
or Pro in the central part of CA-MA may be important in the electrostatic
interaction of the cationic short alpha-helical region in the N-terminus with the
cell membrane surface and the hydrophobic interaction of amphipathic alpha
helical region in the C-terminus with the hydrophobic acyl chains in the cell
membrane. CA-MA3 exhibited lower activity in antibacterial, antitumor, and
vesicle-aggregating and disrupting activities than CA-MA and CA-MA2. This result
suggested that the excessive beta-turn structure by Gly-Pro-Gly in CA-MA3 seems
to interrupt the ion channel/pore formation on the lipid bilayer. It was
concluded that the appropriate flexibility or beta-turn structure provided by the
central hinge is responsible for the effective antibiotic activity of the
antimicrobial peptides with the helix-hinge-helix structure.
PMID- 10675501
TI - A new liposomal formulation for antisense oligodeoxynucleotides with small size,
high incorporation efficiency and good stability.
AB - Antisense oligodeoxynucleotides (asODN) are therapeutic agents that are designed
to inhibit the expression of disease-related genes. However, their therapeutic
use may be hindered due to their rapid clearance from blood and their
inefficiency at crossing cell membranes. Cationic liposome complexes have been
used to enhance the intracellular delivery of asODN in vitro; however, this type
of carrier has unfavorable pharmacokinetics for most in vivo applications.
Significant therapeutic activity of cationic liposomal asODN following systemic
administration has not been demonstrated. In an effort to develop improved
liposomal carriers for asODN for in vivo applications, we have evaluated the
physical characteristics of two formulations which represent alternatives to
cationic liposome-asODN complexes: asODN passively entrapped within neutral
liposomes (PELA) and asODN formulated in a novel coated cationic liposomal
formulation (CCL). Our results confirm that PELA can be extruded to small
diameters that are suitable for intravenous administration. PELA are stable in
human plasma; however, the incorporation efficiency is relatively low (
approximately 20%). The CCL formulation can also be extruded to small diameters
(<200 nm), with significantly higher (80-100%) incorporation efficiency and are
stable in 50% human plasma at 37 degrees C. A liposomal carrier for asODN with
these characteristics may provide a significant therapeutic advantage over free
asODN for some therapeutic applications.
PMID- 10675502
TI - Interaction of cisplatin with planar model membranes - dose dependent change in
electrical characteristics.
AB - The drug cisplatin has broad antineoplastic activity against advanced testicular
and ovarian cancers, epithelial malignancies, cancers of the head, neck, bladder,
oesophagus and lungs. Peripheral neurotoxicity, ototoxicity and nephrotoxicity
are its major side effects. The nonspecific action of this drug on the lipid
bilayer architecture of membranes has been studied by following the effects
produced on the electrical characteristics of model planar bilayer lipid
membranes (BLM). The results confirm that the drug has a strong surface
interaction with the zwitterionic polar head groups of the amphipathic
phospholipids constituting the BLM. The permeability characteristics of cisplatin
through the hydrophobic core are limited. Cisplatin does not fluidise the
membrane sufficiently to cause its breakdown but creates small ion conducting
defects on the membrane bilayer resulting in a marginal increase in ion
conductivity. These results indicate that cisplatin exhibits a non-specific
action on the lipid bilayer component of the membrane which might be partly
responsible for its neurotoxic side effects.
PMID- 10675503
TI - Beta(3)-adrenergic stimulation and insulin inhibition of non-selective cation
channels in white adipocytes of the rat.
AB - Single-channel currents were recorded from the plasma membrane of white
adipocytes of 6-8-week-old male Sprague-Dawley rats. In outside-out patches (high
K(+), no Ca(2+) in pipette), a voltage-dependent K-channel (delayed rectifier)
with a single-channel conductance (gamma) of 16 pS (24 degrees C) in modified
Ringer's was active at a density of 0.5/microm(2). It was blocked by TEA
(IC(50)=1.5 mM). A Ca(2+)-activated non-selective cation channel (NSC-channel)
appeared at a mean density of 1/microm(2) in inside-out patches ([Ca(2+)](i)=1.2
mM). gamma was 28 pS (24 degrees C). The NSC showed weak voltage dependence and
was blocked by mefenamic acid and by internal ATP. In the cell-attached mode
spontaneous activity could be blocked reversibly by 100 nM insulin. Noradrenaline
(NA, 100 nM) induced a flickering activity of the NSC-channels. Isoproterenol
(100 nM) caused activity of the NSC-channel as well. After 1 microM propranolol
even 1 microM NA did not induce any activity. The alpha-antagonist phentolamine
had no effect on isoproterenol- or on NA-induced currents. The beta(3)-agonists
BRL 37344 and BRL 35135A induced activity of the NSC-channel at 100 nM as well.
We conclude that white adipocytes express ion channels which are comparable to
those in brown adipocytes and that beta-receptor activation opens NSC-channels
thus allowing for Na(+) entry into white adipocytes.
PMID- 10675504
TI - Demonstration of a fusion mechanism between a fluid bactericidal liposomal
formulation and bacterial cells.
AB - It was previously demonstrated that fluid liposomal-encapsulated tobramycin,
named Fluidosomes, was successful in eradicating mucoid Pseudomonas aeruginosa in
an animal model of chronic pulmonary infection, whereas free antibiotic did not
reduce colony-forming unit (CFU) counts (C. Beaulac et al., Antimicrob. Agents
Chemother. 40 (1996) 665-669; C. Beaulac et al., J. Antimicrob. Chemother. 41
(1998) 35-41). These liposomes were also shown to be bactericidal in in vitro
tests against strong resistant P. aeruginosa 64 microg/ml). The time needed to
reach the maximal fusion rate was about 5 h for the resistant strain
comparatively to much shorter time for the sensitive strain. The specific
characteristics of Fluidosomes could help overcome bacterial resistance related
to permeability barrier and even enzymatic hydrolysis considering the importance
of synergy in the whole process of antibiotic resistance.
PMID- 10675505
TI - The LEA-like protein HSP 12 in Saccharomyces cerevisiae has a plasma membrane
location and protects membranes against desiccation and ethanol-induced stress.
AB - The LEA-like protein HSP 12 was identified as having a plasma membrane location
in yeast. Gold particles, indicative of the presence of HSP 12, were observed on
the external side of the plasma membrane when yeast grown to stationary phase
were subjected to immunocytochemical analysis. Growth of yeast in the osmolyte
mannitol resulted in an increased number of gold particles that were now observed
to be present on both sides of the plasma membrane. No gold particles were
observed using a mutant strain of the same yeast that did not express HSP 12. A
model liposome system encapsulating the fluorescent dye calcein was used to
investigate the protection by HSP 12 of membranes during desiccation. HSP 12 was
found to act in an analogous manner to trehalose and protect liposomal membrane
integrity against desiccation. The interaction between HSP 12 and the liposomal
membrane was judged to be electrostatic as membrane protection was only observed
with positively charged liposomes and not with either neutral or negatively
charged liposomes. The ability of the wild-type and mutant yeast to grow in media
containing ethanol was compared. It was found that yeast not expressing the HSP
12 protein were less able to grow in media containing ethanol. HSP 12 was shown
to confer increased integrity on the liposomal membrane in the presence of
ethanol. Ethanol, like mannitol, was found to induce HSP 12 protein synthesis.
However, yeast grown in both ethanol and mannitol showed a decreased HSP 12
response compared with yeast grown in the presence of either osmolyte alone.
PMID- 10675506
TI - Calcium enhances the transfection potency of plasmid DNA-cationic liposome
complexes.
AB - It is shown that calcium increases the in vitro transfection potency of plasmid
DNA-cationic liposome complexes from 3- to 20-fold. The effect is Ca(2+) specific
as other cations, such as Mg(2+) and Na(+), do not give rise to enhanced
transfection and the effect can be inhibited by the presence of EGTA. It is shown
that Ca(2+) increases cellular uptake of the DNA-lipid complexes, indicating that
increased transfection potency arises from increased intracellular delivery of
both cationic lipid and plasmid DNA in the presence of Ca(2+). In particular, it
is shown that the levels of intact intracellular plasmid DNA are significantly
enhanced when Ca(2+) is present. The generality of the Ca(2+) effect for
enhancing complex-mediated transfection is demonstrated for a number of different
cell lines and different cationic lipid formulations. It is concluded that
addition of Ca(2+) represents a simple and useful protocol for enhancing in vitro
transfection properties of plasmid DNA-cationic lipid complexes.
PMID- 10675507
TI - Saturable ethanol binding in rat liver mitochondria.
AB - The binding of ethanol to rat liver mitochondria is shown to be saturable at
physiologically relevant ethanol concentrations. This effect is reversible and is
not observed in extracted mitochondrial phospholipids. Brief exposure of the
mitochondria to heat abolishes saturable ethanol binding. Previously, saturable
ethanol binding was reported in rat liver microsomes. Taken together, the studies
indicate that saturable ethanol binding motifs may be widespread in cellular
membranes. The possibility is raised that incomplete expression of the
hydrophobic effect in membrane assembly results in the expression of amphipathic
packing defects which display an affinity for and a sensitivity to ethanol. The
presence of saturable binding modalities is reconciled with the long-standing
consensus on the biodistribution of ethanol - that ethanol's interactions with
tissue are negligible - on the grounds that the affinities of ethanol and of
water for membranes are similar; consequently, free ethanol concentrations are
insensitive to the presence of tissue despite significant ethanol binding. A
fraction of the binding sites possess submillimolar affinities for ethanol
consistent with published functional studies, both in vitro and in vivo, that
reported submillimolar efficacies for ethanol.
PMID- 10675508
TI - Fusion of vesicles with the air-water interface: the influence of polar head
group, salt concentration, and vesicle size.
AB - Fusion of vesicles with the air-water interface and consequent monolayer
formation has been studied as a function of temperature. Unilamellar vesicles of
DMPC, DPPC, and DODAX (X=Cl(-), Br(-)) were injected into a subphase containing
NaCl, and the surface pressure (tension) was recorded on a Langmuir Balance
(Tensiometer) using the Wilhelmy plate (Ring) method. For the zwitterionic
vesicles, plots of the initial surface pressure increase rate (surface tension
decrease rate) as a function of temperature show a peak at the phase transition
temperature (T(m)) of the vesicles, whereas for ionic ones they show a sharp
rise. At high concentrations of NaCl, ionic DODA(Cl) vesicles seem to behave like
zwitterionic ones, and the rate of fusion is higher at the T(m). The influence of
size was studied comparing large DODA(Cl) vesicles with small sonicated ones, and
no significant changes were found regarding the rate of fusion with the air-water
interface.
PMID- 10675509
TI - Cardiolipin, alpha-D-glucopyranosyl, and L-lysylcardiolipin from gram-positive
bacteria: FAB MS, monofilm and X-ray powder diffraction studies.
AB - Cardiolipin preparations from Streptococcus B, Listeria welshimeri,
Staphylococcus aureus, and a glucosyl and lysyl derivative of cardiolipin were
analysed for fatty acid composition and fatty acid combinations. Three different
fatty acid patterns are described and up to 17 molecular species were identified
in Streptococcus B lipids by high resolution FAB MS. The physicochemical
properties of these lipids were characterised in the sodium salt form by monofilm
experiments and X-ray powder diffraction. All lipids formed stable monofilms. The
minimal space requirement of unsubstituted cardiolipin was dictated by the fatty
acid pattern. Substitution with L-lysine led to a decrease of the molecular area,
substitution with D-glucopyranosyl to an increase. On self assembly at 100%
relative humidity, all preparations adopted lamellar structures. They showed a
high degree of order, in spite of the heterogeneous fatty acid compositions and
numerous fatty acid combinations. The repeat distances in lamellar fluid phase
varied between 4.99 and 5. 52 nm, the bilayer thickness between 3.70 and 4.46 nm.
Surprising were the low values of sorbed water per molecule of the glucosyl and
lysyl derivatives which were 58 and 60%, compared with those of the respective
cardiolipin. When Na(+) was replaced as counterion by Ba(2+), the bilayer
structure was retained, but the lipids were in the lamellar gel phase and the
fatty acids were tilted between 32 and 53 degrees away from the bilayer normal.
Wide angle X-ray diffraction studies and electron density profiles are also
reported. Particular properties of glucosyl cardiolipin are discussed.
PMID- 10675510
TI - Deuterium NMR investigation of an amphotericin B derivative in mechanically
aligned lipid bilayers.
AB - The methyl-d(3) amide derivative of the polyene antibiotic amphotericin B was
synthesized, assayed for biological activity, incorporated into mechanically
aligned bilayers of dipalmitoylphosphatidylcholine (DPPC), and examined by
deuterium and phosphorus NMR. The amide derivative has a lesser, but
qualitatively similar, biological activity relative to amphotericin B.
Incorporation of the amide derivative and ergosterol into aligned DPPC bilayers
resulted in a single, stable bilayer phase, as shown by phosphorus NMR of the
DPPC headgroups. Deuterium NMR spectra revealed one major (2)H quadrupolar
splitting and one major (2)H-(1)H dipolar splitting in the liquid-crystalline
phase, consistent with a high degree of alignment and a single, averaged physical
state for amphotericin B methyl-d(3) amide in the bilayer. Variations of the
quadrupolar and dipolar splittings as a function of macroscopic sample
orientation and temperature indicated that the amide derivative undergoes fast
rotation about a motional axis that is parallel to the bilayer normal.
PMID- 10675511
TI - Efficient gene transfer by transferrin lipoplexes in the presence of serum.
AB - Cationic lipids are being used increasingly as reagents for gene delivery both in
vitro and in vivo. One of the limitations to the application of cationic lipid
DNA complexes (lipoplexes) in vivo is the inhibition of gene delivery by serum.
In this study, we have shown that transferrin (Tf)-lipoplexes, which had
transferrin adsorbed at their surface via electrostatic interactions, are much
more effective than plain lipoplexes in transfecting cells in the presence of
relatively high concentrations (up to 60%) of fetal bovine serum (FBS). Serum
even enhanced transfection by Tf-lipoplexes composed of 1,2-dioleoyl-3
(trimethylammonium) propane (DOTAP)/dioleoylphosphatidylethanolamine
(DOPE)/pCMVLacZ at high lipid/DNA (+/-) charge ratios, and inhibited lipofection
for those with low charge ratios when they were added to the cells immediately
after the preparation of complexes. The effect of serum on lipofection was dose
dependent. Preincubation of the complexes at 20 degrees C for 6 h led to serum
resistance, even for the negatively charged transferrin-lipoplexes. A similar
tendency was observed for DOTAP/cholesterol and DOTAP/DOPE/cholesterol liposomes.
The percentage of cells transfected, measured by beta-galactosidase expression,
also increased with the serum concentration. Cell viability was not affected
significantly when the cells were incubated with the complexes for 4 h at 37
degrees C, followed by a 48-h incubation. Our findings extend the scope of
previous studies where transferrin-lipoplexes were used to introduce DNA into
cells, rendering these complexes and their future derivatives potential
alternatives to viral vectors for gene delivery in vivo.
PMID- 10675513
TI - Nucleotide chain length and the morphology of complexes with cationic
amphiphiles: (31)P-NMR observations.
AB - 31P-NMR and UV spectroscopies were used to study the interactions between
cationic amphiphile-containing lipid bilayers and either a phosphorothioate
oligonucleotide (OligoS) (n=21) or polyadenylic acid (PolyA) (n approximately
18,000). Multilamellar vesicles (MLVs) were composed of 1-palmitoyl-2-oleoyl-sn
glycero-3-phosphocholine (POPC) or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine
(DOPE) in binary mixture with either of the cationic lipids, N-[1-(2, 3
dioleoyloxy)propyl]-N',N',N'-trimethylammonium chloride (DOTAP) or
cetyltrimethylammonium bromide (CTAB). A UV-difference assay showed that OligoS
binding ceased above a 1:1 anion/cation ratio, while PolyA binding continued
until a 2:1 ratio was reached, indicating a 'flat' conformation for bound OligoS,
but not necessarily for PolyA. Cross-polarization (31)P-NMR of the nucleotide
chains bound to 100% DOTAP MLVs produced spectra virtually identical to those of
dry powders of OligoS or PolyA, indicating effective immobilization of the
surface-bound nucleotide chains. Hahn echo (31)P-NMR showed that MLVs composed of
binary mixtures of POPC with DOTAP or CTAB retained a lamellar bilayer
architecture upon adding nucleotide chains. At less than stoichiometric
anion/cation ratios little or no signal attributable to free nucleotide chains
was visible. A narrow signal at the chemical shift expected for
phosphorothiodiesters or phosphodiesters became visible at greater levels of
added OligoS or PolyA, respectively, indicating the presence of mobile nucleotide
chains. Salt addition caused complete desorption of the nucleotide chains. When
POPC was replaced with DOPE, binding of OligoS or PolyA produced non-bilayer
lipid phases in the presence of DOTAP, but not in the presence of CTAB.
PMID- 10675512
TI - A peptide analogue to a fusion domain within photoreceptor peripherin/rds
promotes membrane adhesion and depolarization.
AB - Photoreceptor peripherin/rds promotes membrane fusion, through a putative fusion
domain located within the C-terminus (Boesze-Battaglia et al., Biochemistry 37
(1998) 9477-9487). A peptide analogue to this region, PP-5, competitively
inhibits peripherin/rds mediated fusion in a cell free assay system. To
characterize how this region is involved in the fusion process we investigated
two of the individual steps in membrane fusion, membrane adhesion and membrane
destabilization inferred from depolarization studies. Membrane depolarization was
measured as the collapse of a valinomycin induced K(+) diffusion potential in
model membranes, using a potential sensitive fluorescent probe, diS-C(2)-5. PP-5
induced membrane depolarization in a concentration dependent manner. PP-5 has
been shown by Fourier transform infrared spectroscopy to be an amphiphilic alpha
helix. Therefore, the requirement for an amphiphilic alpha-helix to promote
depolarization was tested using two mutant peptides designed to disrupt either
the amphiphilic nature of PP-5 (PP-5AB) or the alpha-helical structure (PP-5HB).
PP-5AB inhibited PP-5 induced depolarization when added in an equimolar ratio to
PP-5. Neither mutant peptide alone or in combination with PP-5 had any effect on
calcium dependent vesicle aggregation. Using non-denaturing gel electrophoresis
and size exclusion chromatography techniques PP-5 was shown to form a tetrameric
complex. Equimolar mixtures of PP-5 and PP-5AB formed a heterotetramer which was
unable to promote membrane depolarization. The hypothesis that PP-5 tetramers
promote membrane depolarization is consistent with the calculated Hill
coefficient of 3.725, determined from a Hill analysis of the depolarization data.
PMID- 10675514
TI - Molecular cloning and expression of aquaporin 1 [correction of aquapolin 1]
(AQP1) in dog kidney and erythroblasts.
AB - Complementary DNA of the water channel aquaporin 1 (AQP1) was cloned from dog
kidney and erythroblasts. The cDNA amplified from mRNA in dog kidney was 816 bp,
the same as that in bovines, but longer by 6 bp than that in humans, mice and
rats. The 235-bp fragment cDNA amplified from the mRNA in dog erythroblasts,
which was differentiated from peripheral blood, was completely identical to the
corresponding sequence of cDNA from the dog kidney. Thus, mature red blood cells
from dog may have AQP1 in their cell membranes. The amino acid sequence in dog
AQP1 was 91-94% identical to that in the other species mentioned above. Dog AQP1
has six predicted transmembrane domains, two NPA motifs, one mercury-sensitive
site and four consensus phosphorylation sites, the same as the other species.
However, dog and bovine AQP1 have only one N-glycosylation site, while two
glycosylation sites were found in human and rodent AQP1. Xenopus oocytes injected
with the mRNA of the dog AQP1 exhibited high water permeability in a hyposmotic
medium. Thus, dog AQP1 performs water transport the same as in the other species.
PMID- 10675515
TI - In vitro characterization of a novel polymeric-based pH-sensitive liposome
system.
AB - This study demonstrates rapid and pH-sensitive release of a highly water-soluble
fluorescent aqueous content marker, pyranine, from egg phosphatidylcholine
liposomes following incorporation of N-isopropylacrylamide (NIPA) copolymers in
liposomal membranes. The pH-sensitivity of this system correlates with the
precipitation of the copolymers at acidic pH. In vitro release can be
significantly improved by increasing the percentage of anchor in the copolymer
and thus favoring its binding to the liposomal bilayer. In the case of liposomes
containing a poly(ethylene glycol)-phospholipid conjugate, the insertion of the
pH-sensitive copolymer in the liposomal membrane appears to be sterically
inhibited. Dye release from these formulations at acidic pH can still be achieved
by varying the anchor molar ratio and/or molecular mass of the polymers or by
including the latter during the liposome preparation procedure. Removal of
unbound polymer results in decreased leakage only when the copolymer is inserted
by incubation with preformed liposomes, but can be overcome by preparing
liposomes in the presence of polymer. Aqueous content and lipid mixing assays
suggest contents release can occur without membrane fusion. The results of this
study indicate that the addition of pH-sensitive copolymers of NIPA represents
promising strategy for improving liposomal drug delivery.
PMID- 10675516
TI - Liquid crystalline/gel state phase separation in docosahexaenoic acid-containing
bilayers and monolayers.
AB - The phase behavior of lipid mixtures containing 1-stearoyl-2-docosahexaenoyl-sn
glycero-3-phosphocholine (18:0, 22:6 PC) with 1,2-dipalmitoyl-sn-glycero-3
phosphocholine (DPPC) was studied with bilayers using differential scanning
calorimetry (DSC), and with monolayers monitoring pressure/area isotherms and
surface elasticity, and lipid domain formation followed by epifluorescence
microscopy. From DSC studies it is concluded that DPPC/18:0, 22:6 PC phase
separates into DPPC-rich and 18:0, 22:6 PC-rich phases. In monolayers, phase
separation is indicated by changes in pressure-area isotherms implying phase
separation where 18:0, 22:6 PC is 'squeezed out' of the remaining DPPC monolayer.
Phase separation into lipid domains in the mixed PC monolayer is quantified by
epifluorescence microscopy using the fluorescently labeled phospholipid membrane
probe, 1, 2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B
sulfonyl). These results further describe the ability of docosahexaenoic acid to
participate in lipid phase separations in membranes.
PMID- 10675517
TI - Properties of a reconstituted eukaryotic hexose/proton symporter solubilized by
structurally related non-ionic detergents: specific requirement of
phosphatidylcholine for permease stability.
AB - Overexpression of the hexose/proton symporter HUP1 from Chlorella kessleri in S.
cerevisiae permits a one-step purification via a biotinylation domain. Milligram
amounts of the protein are obtained starting from 2 l of yeast culture. The HUP1
protein is used as a model eukaryotic membrane protein of the 'major facilitator
superfamily' (MFS) to study specific lipid requirements for activity and
stability. Testing two series of detergents revealed that n-nonyl-beta-D
glucoside (NG) and n-octyl-beta-D-glucoside (OG) solubilize the HUP1 protein
efficiently. Only the use of NG resulted in long-term stabilization of the HUP1
protein in the absence of external lipids. When affinity purified protein was
extracted with organic solvents, a stoichiometric amount of phosphatidyl choline,
phosphatidyl ethanolamine and ergosterol in the ratio of close to 2:1 was
detected. These lipids were only observed, however, when the protein purification
was carried out in the presence of NG; no lipids were copurified with the HUP1
protein in the presence of OG. Of the three lipids copurified, phosphatidyl
choline showed a crucial role in ensuring maximal HUP1 permease activity and
stability when added back to the OG-protein. The requirement of
phosphatidylcholine documents a specific effect of lipids on vectorial transport
mediated by a eukaryotic membrane protein of the MFS family.
PMID- 10675518
TI - Selective destabilization of acidic phospholipid bilayers performed by the
hepatitis B virus fusion peptide.
AB - A peptide corresponding to the N-terminal region of the S protein of hepatitis B
virus (Met-Glu-Asn-Ile-Thr-Ser-Gly-Phe-Leu-Gly-Pro-Leu-Leu-Val-Leu-Gln) has been
previously demonstrated to perform aggregation and destabilization of acidic
liposome bilayers and to adopt a highly stable beta-sheet conformation in the
presence of phospholipids. The changes in the lipid moiety produced by this
peptide have been followed by fluorescence depolarization and electron
microscopy. The later was employed to determine the size and shape of the peptide
vesicle complexes, showing the presence of highly aggregated and fused structures
only when negatively charged liposomes were employed. 1,6-Diphenyl-1,3,5
hexatriene depolarization measurements showed that the interaction of the peptide
with both negatively charged and zwitterionic liposomes was accompanied by a
substantial reduction of the transition amplitude without affecting the
temperature of the gel-to-liquid crystalline phase transition. These data are
indicative of the peptide insertion inside the bilayer of both types of liposomes
affecting the acyl chain order, though only the interaction with acidic
phospholipids leads to aggregation and fusion. This preferential destabilization
of the peptide towards negatively charged phospholipids can be ascribed to the
electrostatic interactions between the peptide and the polar head groups, as
monitored by 1-(4-(trimethylammoniumphenyl)-6-phenyl-1,3, 5-hexatriene
fluorescence depolarization analysis.
PMID- 10675519
TI - Redox- and pH-dependent association of plastocyanin with lipid bilayers: effect
on protein conformation and thermal stability.
AB - The effect of electrostatic interactions on the conformation and thermal
stability of plastocyanin (Pc) was studied by infrared spectroscopy. Association
of any of the two redox states of the protein with positively charged membranes
at neutral pH does not significantly change the secondary structure of Pc.
However, upon membrane binding, the denaturation temperature decreases,
regardless of the protein redox state. The extent of destabilization depends on
the proportion of positively charged lipid headgroups in the membrane, becoming
greater as the surface density of basic phospholipids increases. In contrast, at
pH 4.8 the membrane binding-dependent conformational change becomes redox
sensitive. While the secondary structures and thermal stabilities of free and
membrane-bound oxidized Pc are similar under acidic conditions, the conformation
of the reduced form of the protein drastically rearranges upon membrane
association. This rearrangement does not depend on electrostatic interactions to
occur, since it is also observed in the presence of uncharged lipid bilayers. The
conformational transition, only observed for reduced Pc, involves the exposure of
hydrophobic regions that leads to intermolecular interactions at the membrane
surface. Membrane-mediated partial unfolding of reduced Pc can be reversed by
readjusting the pH to neutrality, in the absence of electrostatic interactions.
This redox-dependent behavior might reflect specific structural requirements for
the interaction of Pc with its redox partners.
PMID- 10675520
TI - Effect of free fatty acids on the permeability of 1,2-dimyristoyl-sn-glycero-3
phosphocholine bilayer at the main phase transition.
AB - We measured the influence of saturated and unsaturated free fatty acids on the
permeability and partition of ions into 1, 2-dimyristoyl-sn-glycero-3
phosphocholine (DMPC) bilayers. The bilayer permeability was measured using the
depletion of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1, 2-dihexadecanoyl-sn-glycero
3-phosphatidylethanolamine (N-NBD-PE) fluorescence as a result of its reduction
by dithionite. We observed a distinct increase of dithionite permeability at the
main gel-fluid phase transition of DMPC. When vesicles were formed from a mixture
of DMPC and oleic acid, the membrane permeability at the phase transition was
reduced drastically. Stearic acid and methyl ester of oleic acid have little
effect. Similar results in the quenching of pyrene-PC in DMPC vesicles by iodide
were obtained. Again, the increase of iodide partition into the lipid phase at
the main phase transition of DMPC was abolished by the addition of unsaturated
free fatty acids. Free fatty acids, in concentrations up to 5 mol%, do not
abolish DMPC phase transition when measured by differential scanning calorimetry.
It seems that unsaturated, but not saturated, free fatty acids reduce the lipid
bilayer permeability to dithionite and iodide ions at the main phase transition
of DMPC, without altering the thermodynamic properties of the bilayer.
PMID- 10675521
TI - The plasma membrane NADH oxidase of soybean has vitamin K(1) hydroquinone oxidase
activity.
AB - Isolated plasma membrane vesicles and the plasma membrane NADH oxidase partially
purified from soybean plasma membrane vesicles exhibited a cyanide-insensitive
vitamin K(1) hydroquinone oxidase activity with isolated plasma membrane
vesicles. Reduced vitamin K(1) (phylloquinol) was oxidized at a rate of about 10
nmol/min/mg protein as determined by reduced vitamin K(1) reduction or oxygen
consumption. The K(m) for reduced K(1) was 350 microM. With the partially
purified enzyme, reduced vitamin K(1) was oxidized at a rate of about 600
nmol/min/mg protein and the K(m) was 400 microM. When assayed in the presence of
1 mM KCN, activities of both plasma membrane vesicles and of the purified protein
were stimulated (0.1 microM) or inhibited (0.1 mM) by the synthetic auxin growth
factor 2, 4-dichlorophenoxyacetic acid. The findings suggest the potential
participation of the plasma membrane NADH oxidase as a terminal oxidase of plasma
membrane electron transport from cytosolic NAD(P)H via reduced vitamin K(1) to
acceptors (molecular oxygen or protein disulfides) at the cell surface.
PMID- 10675523
TI - Characterization of a cDNA encoding a rice mitochondrial voltage-dependent anion
channel and its gene expression studied upon plant development and osmotic
stress.
AB - The voltage-dependent anion channel (VDAC) of mitochondria forms a large pore in
the outer envelope membrane. Here, the full Oryza sativa OSVDAC1 cDNA was
sequenced and is shown to belong to a small multigene family in the rice genome.
This cDNA is 1093 bp long and codes for a protein of 274 amino acids. Expression
studies of the osvdac1 gene show a regulation of its level in function of the
plantlets maturation and organs. In contrast with several bacterial porins,
osmotic stress does not have any effect on the plant osvdac1 gene expression.
PMID- 10675522
TI - Human serum albumin enhances DNA transfection by lipoplexes and confers
resistance to inhibition by serum.
AB - Cationic liposome-DNA complexes ('lipoplexes') are used as gene delivery vehicles
and may overcome some of the limitations of viral vectors for gene therapy
applications. The interaction of highly positively charged lipoplexes with
biological macromolecules in blood and tissues is one of the drawbacks of this
system. We examined whether coating cationic liposomes with human serum albumin
(HSA) could generate complexes that maintained transfection activity. The
association of HSA with liposomes composed of 1, 2-dioleoyl-3-(trimethylammonium)
propane and dioleoylphosphatidylethanolamine, and subsequent complexation with
the plasmid pCMVluc greatly increased luciferase expression in epithelial and
lymphocytic cell lines above that obtained with plain lipoplexes. The percentage
of cells transfected also increased by an order of magnitude. The zeta potential
of the ternary complexes was lower than that of the lipoplexes. Transfection
activity by HSA-lipoplexes was not inhibited by up to 30% serum. The combined use
of HSA and a pH-sensitive peptide resulted in significant gene expression in
human primary macrophages. HSA-lipoplexes mediated significantly higher gene
expression than plain lipoplexes or naked DNA in the lungs and spleen of mice.
Our results indicate that negatively charged HSA-lipoplexes can facilitate
efficient transfection of cultured cells, and that they may overcome some of the
problems associated with the use of highly positively charged complexes for gene
delivery in vivo.
PMID- 10675524
TI - Expression and subcellular localization of a membrane protein related to Hsp30p
in Saccharomyces cerevisiae.
AB - The Saccharomyces cerevisiae YDR033w gene product is homologous to Hsp30p and
Yro2p, both of which are induced during heat shock. To investigate the
subcellular localization of the YDR033w gene product, hemagglutinin (HA) epitope
tagged protein was expressed, detected on immunoblots, and localized by
immunofluorescence to cell membranes, primarily the plasma membrane. A punctuate
immunofluorescence pattern was observed within cell buds. The nuclear envelope,
but not the vacuole or mitochondrial membranes, were also immunostained. We refer
to YDR033w as MRH1 to denote that it encodes a membrane protein related to
Hsp30p.
PMID- 10675525
TI - Is the manganese stabilizing 33 kDa protein of photosystem II attaining a
'natively unfolded' or 'molten globule' structure in solution?
AB - This study compares the properties of the extrinsic 33 kDa subunit acting as
'manganese stabilizing protein' (MSP) of the water oxidizing complex with
characteristic features of proteins that are known to attain a 'natively
unfolded' or a 'molten globule' structure. The analysis leads to the conclusion
that the MSP in solution is most likely a 'molten globule' with well defined
compact regions of beta structure. The possible role of these structural
peculiarities of MSP in solution for its function as important constituent of the
WOC is discussed.
PMID- 10675526
TI - Inhibition of chymase reduces vascular proliferation in dog grafted veins.
AB - We investigated the effect of a chymase inhibitor Suc-Val-Pro-Phe(P)(OPh)(2) on
the proliferation of the grafted vein in dog. By 28 days after the operation, the
mean intimal area of the grafted vein in the placebo group was 3.24+/-0.32 mm(2).
The intimal area of the grafted vein in the chymase inhibitor-treated group was
reduced to 63.9%. In the placebo group, the activities of chymase and angiotensin
converting enzyme in grafted vein were significantly increased 15- and 2-fold,
respectively. In the chymase inhibitor-treated group, chymase activity in the
grafted veins was decreased significantly. These findings suggest that inhibition
of chymase appears useful for preventing vascular proliferation.
PMID- 10675527
TI - First evidence and characterization of an uncoupling protein in fungi kingdom:
CpUCP of Candida parapsilosis.
AB - An uncoupling protein (UCP) was identified in mitochondria from Candida
parapsilosis (CpUCP), a non-fermentative parasitic yeast. CpUCP was
immunodetected using polyclonal antibodies raised against plant UCP. Activity of
CpUCP, investigated in mitochondria depleted of free fatty acids, was stimulated
by linoleic acid (LA) and inhibited by GTP. Activity of CpUCP enhanced state 4
respiration by decreasing DeltaPsi and lowered the ADP/O ratio. Thus, it was able
to divert energy from oxidative phosphorylation. The voltage dependence of
electron flux indicated that LA had a pure protonophoretic effect. The discovery
of CpUCP proves that UCP-like proteins occur in the four eukaryotic kingdoms:
animals, plants, fungi and protists.
PMID- 10675528
TI - Prothymosin alpha fragmentation in apoptosis.
AB - We observed fragmentation of an essential proliferation-related human nuclear
protein prothymosin alpha in the course of apoptosis induced by various stimuli.
Prothymosin alpha cleavage occurred at the DDVD(99) motif. In vitro, prothymosin
alpha could be cleaved at D(99) by caspase-3 and -7. Caspase hydrolysis disrupted
the nuclear localization signal of prothymosin alpha and abrogated the ability of
the truncated protein to accumulate inside the nucleus. Prothymosin alpha
fragmentation may therefore be proposed to disable intranuclear proliferation
related function of prothymosin alpha in two ways: by cleaving off a short
peptide containing important determinants, and by preventing active nuclear
uptake of the truncated protein.
PMID- 10675529
TI - Nitric oxide donors, nitrosothiols and mitochondrial respiration inhibitors
induce caspase activation by different mechanisms.
AB - We investigated to what extent different types of NO donors induce caspase
activation by opening of the mitochondrial permeability transition pore (PTP) or
inhibition of mitochondrial respiration. We found that nitrosothiols can directly
open the PTP in isolated mitochondria and cause cytochrome c release, whereas
NONOate donors can not. In macrophages nitrosothiols cause caspase activation
that is blocked by cyclosporin A or calcium chelation, both of which prevent PTP
opening, whereas caspase activation caused by NONOates is much less sensitive to
these agents. Inhibitors of mitochondrial respiration did not promote PTP opening
in isolated mitochondria, and although they cause caspase activation in
macrophages, this activation was slower than that caused by NO donors, and was
relatively insensitive to cyclosporin and calcium chelators suggesting that PTP
opening was not involved.
PMID- 10675530
TI - TAK1 mediates an activation signal from toll-like receptor(s) to nuclear factor
kappaB in lipopolysaccharide-stimulated macrophages.
AB - Stimulation of monocytes/macrophages with lipopolysaccharide (LPS) results in
activation of nuclear factor-kappaB (NF-kappaB), which plays crucial roles in
regulating expression of many genes involved in the subsequent inflammatory
responses. Here, we investigated roles of transforming growth factor-beta
activated kinase 1 (TGF-TAK1), a mitogen-activated protein kinase kinase kinase
(MAPKKK), in the LPS-induced signaling cascade. A kinase-negative mutant of TAK1
inhibited the LPS-induced NF-kappaB activation both in a macrophage-like cell
line, RAW 264.7, and in human embryonic kidney 293 cells expressing toll-like
receptor 2 or 4. Furthermore, we demonstrated that endogenous TAK1 is
phosphorylated upon simulation of RAW 264.7 cells with LPS. These results
indicate that TAK1 functions as a critical mediator in the LPS-induced signaling
pathway.
PMID- 10675531
TI - High-molecular-weight kininogen is a binding protein for tissue prokallikrein.
AB - Human tissue prokallikrein, a zymogen of the kallikrein-kinin system, circulates
in plasma bound to neutrophils. Because plasma kininogens contribute to the
assembly of kinin-generating components on blood cells, these proteins were
assessed for their ability to complex the kallikrein precursor. Using ligand blot
and direct binding assays, biotinylated prokallikrein was found to bind only to
high-molecular-weight kininogen and not to the low-molecular-weight form. The
interaction was specific, reversible, and saturable yielding an estimated
dissociation constant K(D)=690 nM and a 1:1 stoichiometry. Specific kininogen
binding of tissue prokallikrein also occurred at physiological plasma protein
concentrations. These results provide the first evidence for a novel function of
high-molecular-weight kininogen as a binding protein for tissue prokallikrein
that could serve to localize the kallikrein precursor on the neutrophil surface.
PMID- 10675532
TI - Distinct importin recognition properties of histones and chromatin assembly
factors.
AB - Synthesis of the protein components of nuclear chromatin occurs in the cytoplasm,
necessitating specific import into the nucleus. Here, we report the binding
affinities of the nuclear localisation sequence (NLS)-binding importin subunits
for a range of histones and chromatin assembly factors. The results suggest that
import of histones to the nucleus may be mediated predominantly by importin
beta1, whereas the import of the other components probably relies on the
conventional alpha/beta1 import pathway. Differences in recognition by importin
beta1 were observed between histone H2A and the variant H2AZ, as well as between
histone H3/4 with or without acetylation. The results imply that different
histone variants may possess distinct nuclear import properties, with acetylation
possibly playing an inhibitory role through NLS masking.
PMID- 10675533
TI - Defect in modification at the anticodon wobble nucleotide of mitochondrial
tRNA(Lys) with the MERRF encephalomyopathy pathogenic mutation.
AB - A mitochondrial tRNA(Lys) gene mutation at nucleotide position 8344 is
responsible for the myoclonus epilepsy associated with ragged-red fibers (MERRF)
subgroup of mitochondrial encephalomyopathies. Here, we show that normally
modified uridine at the anticodon wobble position remains unmodified in the
purified mutant tRNA(Lys). We have reported a similar modification defect at the
same position in two mutant mitochondrial tRNAs(Leu)(UUR) in another subgroup,
mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes
(MELAS), indicating this defect is common in the two kinds of tRNA molecules with
the respective mutations of the two major mitochondrial encephalomyopathies. We
therefore suggest the defect in the anticodon is responsible, through the
translational process, for the pathogenesis of mitochondrial diseases.
PMID- 10675535
TI - Rap1-suppressed tumorigenesis is concomitant with the interference in ras
effector signaling.
AB - Expression of Rap1 blocks epithelial growth factor-induced extracellular signal
regulated kinases (ERKs) activation. However, recent studies demonstrated that
Rap1 mediates ERKs activation induced by nerve growth factor. The anti-oncogenic
effect of Rap1 has been reported but its mechanism remains unclear. To evaluate
the correlation between the anti-transforming effect and the activation of ERKs,
we transfected rap1 cDNA into Hep3B cells and selected stable transfectants. The
Rap1 transfectants completely lost their intrinsic tumorigenicity in Balb/c nude
mice. Both insulin and 12-O-tetradecanoyl phorbol-13-acetate (TPA)-stimulated ERK
activations were also blocked. Our findings suggest that Rap1-suppressed
tumorigenicity is concomitant with ERKs inhibition.
PMID- 10675534
TI - Identification and characterization of functional subunits of Clostridium
botulinum type A progenitor toxin involved in binding to intestinal microvilli
and erythrocytes.
AB - Clostridium botulinum type A hemagglutinin-positive progenitor toxin consists of
three distinct components: neurotoxin (NTX), hemagglutinin (HA), and non-toxic
non-HA (NTNH). The HA consists of four subcomponents designated HA1, 2, 3a and
3b. By employing purified toxin and GST-fusion proteins of each HA subcomponent,
we found that the HA-positive progenitor toxin, GST-HA1 and GST-HA3b bind to
human erythrocytes and microvilli of guinea pig upper small intestinal sections.
The HA-positive progenitor toxin and GST-HA1 bind via galactose moieties, GST
HA3b binds via sialic acid moieties. GST-2 and GST-3a showed no detectable
binding.
PMID- 10675536
TI - Drosophila MTN: a metazoan copper-thionein related to fungal forms.
AB - Two Drosophila metallothioneins (MT) have been reported: MTN, a 40 residue
peptide including 10 Cys, and MTO, a 43 residue peptide including 12 Cys.
However, neither functional nor evolutionary analyses for either of the
Drosophila MT are available. Here, heterologous expression of Mtn in Escherichia
coli is reported. The metal binding abilities of the Cu- and Zn-MTN complexes
conformed in vivo, as well as the features of the Cd- and Cu-aggregates produced
by metal replacement in vitro, have been determined by atomic emission
spectrometry, circular dichroism and electrospray ionization mass spectrometry.
Primary structure relationships with other MT have been examined. The results
indicate a close resemblance of MTN to fungal copper-thioneins.
PMID- 10675537
TI - Novel substrate specificity of a membrane-bound beta-glycosidase from the
hyperthermophilic archaeon Pyrococcus horikoshii.
AB - A beta-glycosidase gene homolog of Pyrococcus horikoshii (BGPh) was successfully
expressed in Escherichia coli. The enzyme was localized in a membrane fraction
and solubilized with 2.5% Triton X-100 at 85 degrees C for 15 min. The optimum pH
was 6.0 and the optimum temperature was over 100 degrees C, respectively. BGPh
stability was dependent on the presence of Triton X-100, the enzyme's half-life
at 90 degrees C (pH 6.0) was 15 h. BGPh has a novel substrate specificity with
k(cat)/K(m) values high enough for hydrolysis of beta-D-Glcp derivatives with
long alkyl chain at the reducing end and low enough for the hydrolysis of beta
linked glucose dimer more hydrophilic than aryl- or alkyl-beta-D-Glcp.
PMID- 10675538
TI - Tumor necrosis factor-induced lethal hepatitis: pharmacological intervention with
verapamil, tannic acid, picotamide and K76COOH.
AB - Tumor necrosis factor (TNF) induces hepatitis when injected in human beings or in
rodents. The molecular mechanism by which TNF induces hepatic distress remains
largely unknown, although induction of apoptosis of hepatocytes appears to be an
essential step. In order to increase the therapeutic value of TNF, we have
studied the protective activity of several molecules and found that four
chemically totally different substances confer significant protection in the
model of TNF-induced lethal hepatitis in mice sensitized with D-(+)-galactosamine
(GalN), but not in mice sensitized with actinomycin-D (ActD) or against anti-Fas
induced lethal hepatitis. Verapamil, a calcium-channel blocker, tannic acid,
picotamide, a thromboxane A(2) receptor antagonist, and K76COOH, an inhibitor,
amongst others, of complement, protected significantly against induction of
lethality, release of the liver-specific enzyme alanine aminotransferase (ALT)
and induction of apoptosis in the liver after TNF/GalN, except for K76COOH, which
paradoxically increased ALT values after challenge, and which also protected
against TNF/GalN in complement-deficient mice. The data suggest that activation
of platelets and neutrophils, as well as induction of inflammation occur in the
TNF/GalN model, but not in the TNF/ActD or anti-Fas models, in which direct
induction of apoptosis of hepatocytes may be more relevant. The protective
activity of the drugs may lead to an increase in therapeutic value of TNF.
PMID- 10675539
TI - Biotic and abiotic stress can induce cystatin expression in chestnut.
AB - A cysteine proteinase inhibitor (cystatin) from chestnut (Castanea sativa) seeds,
designated CsC, has been previously characterized. Its antifungal, acaricide and
inhibitory activities have allowed to involve CsC in defence mechanisms. The CsC
transcription levels decreased during seed maturation and increased throughout
germination, an opposite behavior to that shown by most phytocystatins. No
inhibition of endogenous proteinase activity by purified CsC was found during the
seed maturation or germination processes. CsC message accumulation was induced in
chestnut leaves after fungal infection, as well as by wounding and jasmonic acid
treatment. Induction in roots was also observed by the last two treatments.
Furthermore, CsC transcript levels strongly raised, both in roots and leaves,
when chestnut plantlets were subjected to cold- and saline-shocks, and also in
roots by heat stress. All together, these data suggest that chestnut cystatin is
not only involved in defence responses to pests and pathogen invasion, but also
in those related to abiotic stress.
PMID- 10675540
TI - Possible role of immune surveillance at the initial phase of metastasis produced
by B16BL6 melanoma cells.
AB - The relationship among the real-time trafficking of lung metastatic B16BL6 cells,
metastatic potential, and the injected number of the cells was examined, since
the smaller the number of tumor cells injected, the more clearly the immune
defense may be observed. When 1x10(6) or 1x10(5) B16BL6 cells were injected into
mice via the tail vein, both numbers of cells accumulated in the lung at a
similar rate: there was an approximately 10-fold difference in the number of
accumulated cells between the two doses. Elimination from the lung was not
dependent on the cell number but on the proportion of accumulated cells. However,
the injection of 1x10(4) cells resulted in lung accumulation less than one-tenth
of that obtained with 1x10(5) cell injection. Metastasis was observed when
1x10(5) or 1x10(6) B16BL6 cells were injected, but not after injection of 1x10(4)
cells. To clarify the roles of the immune defense system at the initial phase of
metastasis, we challenged macrophage-depleted mice with 1x10(4) tumor cells.
Treatment of mice with 2-chloroadenosine prior to the tumor cell challenge
cancelled the suppression of not only metastasis but also the lung accumulation.
Furthermore, the administration of 2-chloroadenosine following the tumor cell
challenge had little effect on the metastatic potential. These results suggest
that the immune surveillance whose action was obvious at the low dose of
challenged tumor cells functions strongly at the initial phase but not at the
advanced stages of the metastatic process, and that macrophages play an important
role in the suppression of metastasis.
PMID- 10675541
TI - LOX-1 mediates lysophosphatidylcholine-induced oxidized LDL uptake in smooth
muscle cells.
AB - A novel receptor for oxidized low-density lipoprotein (OxLDL), lectin-like OxLDL
receptor (LOX-1), was cloned from endothelial cells. Since OxLDL is taken up by
vascular smooth muscle cells (VSMC) in atheroma, we analyzed the inducible
expression of LOX-1 in VSMC in the present study. Incubation of cultured bovine
VSMC with lysophosphatidylcholine (LPC), an atherogenic component of OxLDL,
increased the level of mRNA for LOX-1 in a dose- and time-dependent manner. Since
LPC did not significantly change the half-life of LOX-1 mRNA, the induction
seemed to occur at the transcriptional level. The induction accompanied an
increase in the protein level of LOX-1 and activity of OxLDL uptake. Blocking
antibody against LOX-1 significantly suppressed the enhanced uptake of OxLDL.
Thus, LOX-1 is a major receptor for OxLDL in VSMC as in endothelial cells. The
enhanced expression of LOX-1 by LPC suggests that OxLDL and LPC would
progressively change the function of VSMC and accelerate atherogenesis in vivo.
PMID- 10675542
TI - Kinetic and spectroscopic characterization of native and metal-substituted beta
lactamase from Aeromonas hydrophila AE036.
AB - Two metal ion binding sites are conserved in metallo-beta-lactamase from
Aeromonas hydrophila. The ligands of a first zinc ion bound with picomolar
dissociation constant were identified by EXAFS spectroscopy as one Cys, two His
and one additional N/O donor. Sulfur-to-metal charge transfer bands are observed
for all mono- and di-metal species substituted with Cu(II) or Co(II) due to
ligation of the single conserved cysteine residue. Binding of a second metal ion
results in non-competitive inhibition which might be explained by an alternative
kinetic mechanism. A possible partition of metal ions between the two binding
sites is discussed.
PMID- 10675543
TI - Structural domains of the insulin receptor and IGF receptor required for
dimerisation and ligand binding.
AB - We investigated structural requirements for dimerisation and ligand binding of
insulin/IGF receptors. Soluble receptor fragments consisting of N-terminal
domains (L1/CYS/L2, L1/CYS/L2/F0) or fibronectin domains (F0/F1/F2, F1/F2) were
expressed in CHO cells. Fragments containing F0 or F1 domains were secreted as
disulphide-linked dimers, and those consisting of L1/CYS/L2 domains as monomers.
None of these proteins bound ligand. However, when a peptide of 16 amino acids
from the alpha-subunit C-terminus was fused to the C-terminus of L1/CYS/L2, the
monomeric insulin and IGF receptor constructs bound their respective ligands with
affinity only 10-fold lower than native receptors.
PMID- 10675544
TI - The molecular basis for genetic polymorphism of human deoxyribonuclease II (DNase
II): a single nucleotide substitution in the promoter region of human DNase II
changes the promoter activity.
AB - Deoxyribonuclease II (DNase II) levels in human vary depending on whether the
individual has the DNASE2*H (high) allele or the DNASE2*L (low) allele. We
examined the promoter activity of the 5'-flanking region of each of these alleles
by transient transfection luciferase assay. DNASE2*H had 5-fold higher promoter
activity than DNASE2*L in human hepatoma HepG2 cell. Comparison of the nucleotide
sequences of the proximal promoter regions revealed a G to A transition at
position -75; G and A residues were assigned to DNASE2*H and *L, respectively.
Since no differences were found between the open reading frame sequences of these
alleles, it is likely that the A-75G transition causes the allelic difference in
the promoter activity of the gene, underlying the genetic polymorphism.
PMID- 10675545
TI - Isolation of acein-2, a novel angiotensin-I-converting enzyme inhibitory peptide
derived from a tryptic hydrolysate of human plasma.
AB - We previously described a novel angiotensin-I-converting enzyme (ACE) inhibitory
peptide, designated Acein-1, that was isolated from a tryptic hydrolysate of
human plasma. We now report a second such inhibitory peptide, Acein-2 obtained
from the same hydrolysate. The peptide was purified by gel filtration and cation
exchange chromatography followed by reversed-phase gradient and isocratic high
performance liquid chromatography. Acein-2 was found to be a tripeptide, Leu-Ile
Tyr, which is thought to correspond to f(518-520) of human alpha2-macroglobulin.
The synthetic tripeptide showed a potent dose-dependent inhibition of ACE, with
an IC(50) value of 0.82 micromol/l. Lineweaver-Burk plots suggested that Acein-2
as well as the previously described Acein-1 are non-competitive inhibitors.
PMID- 10675546
TI - Post-translational phosphorylation affects the IgE binding capacity of caseins.
AB - IgE response specific to those molecular regions of casein that contain a major
phosphorylation site was analyzed using native and modified caseins and derived
peptides. This study included (i) the naturally occurring common variants A1 and
A from beta- and alphas2-caseins, respectively, which were purified in the native
form and then dephosphorylated, (ii) a purified rare variant D of alphas2-casein
which lacks one major phosphorylation site, and (iii) the native and
dephosphorylated tryptic fragment f(1-25) from beta-casein. Direct and indirect
ELISA using sera from patients allergic to milk showed that the IgE response to
caseins is affected by modifying or eliminating the major phosphorylation site.
PMID- 10675547
TI - Involvement of CDSP 32, a drought-induced thioredoxin, in the response to
oxidative stress in potato plants.
AB - In animal cells, yeast and bacteria, thioredoxins are known to participate in the
response to oxidative stress. We recently identified a novel type of plant
thioredoxin named CDSP 32 for chloroplastic drought-induced stress protein of 32
kDa. In the present work, we measured comparable increases in the glutathione
oxidation ratio and in the level of chlorophyll thermoluminescence, a specific
marker for thylakoid lipid peroxidation in Solanum tuberosum plants subjected to
drought or oxidative treatments (photooxidative stress, gamma irradiation and
methyl viologen spraying). Further, substantial accumulations of CDSP 32 mRNA and
protein were revealed upon oxidative treatments. These data show for the first
time in plants the induction of a thioredoxin by oxidative stress. We conclude
that CDSP 32 may preserve chloroplastic structures against oxidative injury upon
drought.
PMID- 10675548
TI - SNS/PN3 and SNS2/NaN sodium channel-like immunoreactivity in human adult and
neonate injured sensory nerves.
AB - Two tetrodotoxin-resistant voltage-gated sodium channels, SNS/PN3 and SNS2/NaN,
have been described recently in small-diameter sensory neurones of the rat, and
play a key role in neuropathic pain. Using region-specific antibodies raised
against different peptide sequences of their alpha subunits, we show by Western
blot evidence for the presence of these channels in human nerves and sensory
ganglia. The expected fully mature 260 kDa component of SNS/PN3 was noted in all
injured nerve tissues obtained from adults; however, for SNS2/NaN, smaller bands
were found, most likely arising from protein degradation. There was increased
intensity of the SNS/PN3 260 kDa band in nerves proximal to the site of injury,
whereas it was decreased distally, suggesting accumulation at sites of injury;
all adult patients had a positive Tinel's sign at the site of nerve injury,
indicating mechanical hypersensitivity. Injured nerves from human neonates showed
similar results for both channels, but neonate neuromas lacked the SNS2/NaN 180
kDa molecular form, which was strongly present in adult neuromas. The
distribution of SNS/PN3 and SNS2/NaN sodium channels in injured human nerves
indicates that they represent targets for novel analgesics, and could account for
some differences in the development of neuropathic pain in infants.
PMID- 10675549
TI - Roles of p38 MAPK, PKC and PI3-K in the signaling pathways of NADPH oxidase
activation and phagocytosis in bovine polymorphonuclear leukocytes.
AB - Stimulation of bovine polymorphonuclear leukocytes (PMN) with serum-opsonized
zymosan (sOZ) induced the activation of p38 mitogen-activated protein kinase
(MAPK), protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3-K) and sOZ
induced O(2)(-) production was significantly attenuated by their inhibitors
(SB203580 for p38 MAPK, GF109203X for PKC and wortmannin for PI3-K). They caused
significant attenuation of sOZ-induced phosphorylation of p47phox as well. Flow
cytometric analysis, however, revealed that SB203580 and wortmannin attenuated
phagocytosis, but GF109203X facilitated it. The results suggest that p38 MAPK and
PI3-K participated in both signaling pathways of NADPH oxidase activation (O(2)(
) production) and phagocytosis, and PKC participated in the signaling pathway of
NADPH oxidase activation alone.
PMID- 10675550
TI - Peroxisome proliferator-activated receptors are expressed in mouse bone marrow
derived mast cells.
AB - We examined the expression of peroxisome proliferator-activated receptors (PPARs)
and the role of PPARs in cytokine production in mouse bone marrow-derived mast
cells (mBMMCs). mBMMCs expressed PPARbeta strongly and gamma slightly, but not
alpha. Activation of mBMMCs with antigen or calcium ionophore resulted in the
increased expression of PPARgamma mRNA specifically. 15-Deoxy-Delta(12, 14)
prostaglandin J(2) (15d-PGJ(2)) and troglitazone, all PPARgamma ligands,
attenuated the antigen-induced cytokine production by mBMMCs. Carbaprostacyclin,
a PPARbeta ligand, also inhibited cytokine production, whereas PPARalpha ligands
did not. These results suggest that PPARbeta and gamma might be included in the
negative regulation of mast cell activation.
PMID- 10675551
TI - Expression of fatty acid-CoA ligase 4 during development and in brain.
AB - Fatty acid utilization is initiated by fatty acid-CoA ligase, which converts free
fatty acids into fatty acyl-CoA esters. We have cloned previously the human long
chain fatty acid-CoA ligase 4 (FACL4), which is a central enzyme in controlling
the free arachidonic acid level in cells and thereby regulating eicosanoid
production. We report here the expression of this gene in tissues, particularly
in different parts of the brain. We found that FACL4 encoded a 75 kDa enzyme and
that there was a modified translation product expressed in the brain. FACL4 was
expressed in early stages of development with a significant amount of FACL4 mRNA
detected in an E7 mouse embryo. In addition, FACL4 was highly expressed in both
adult and newborn mouse brain especially in the granule cells of the dentate
gyrus and the pyramidal cell layer of CA1 in hippocampus, and the granular cell
layer and Purkinje cells of the cerebellum.
PMID- 10675552
TI - Identification of a stimulus-dependent DNase I hypersensitive site between the
Ialpha and Calpha exons during immunoglobulin heavy chain class switch
recombination.
AB - The complete humoral response to foreign antigen depends upon two distinct
recombination events within the heavy chain locus of immunoglobulin. The first
recombination event takes place in what will become the antigen combining site of
the antibody molecule, encoded by V, D and J segments. The second recombination
event involves the looping-out of large spans of DNA which separate the various
clusters of heavy chain exons which define the different immunoglobulin isotypes,
or classes. While a great deal has been learned about the nature of the VDJ
recombinase, very little is known about the nature of the class-switch
recombinase. Using a cell system where class-switch recombination occurs
primarily to the IgA locus, we have looked for stimulus-dependent changes in the
chromatin structure of the IgA locus which might result from interactions between
components of the recombinase and cis-elements within the region. We present
evidence that strongly suggests that the class-switch recombinase interacts
between the Ialpha and Calpha exons of IgA, just upstream of the highly
reiterated DR1 and DR2 elements. However, although multiple potential SMAD-4
sites are located precisely within the DNase I hypersensitive site and 160 bp
upstream of that site, we failed to detect any evidence of DNA/protein
interactions near the hypersensitive site. Moreover, recombinant SMAD-3/4
proteins fail to interact with these sites with appreciable affinity in vitro.
These data suggest that some other structural alteration at this site (e.g.
RNA/DNA hybrid) may mediate the nuclease sensitivity.
PMID- 10675553
TI - Characterization of Arabidopsis AtAMT2, a novel ammonium transporter in plants.
AB - We have cloned and characterized the first member of a novel family of ammonium
transporters in plants: AtAMT2 from Arabidopsis thaliana. AtAMT2 is more closely
related to bacterial ammonium transporters than to plant transporters of the AMT1
family. The protein was expressed and functionally characterized in yeast. AtAMT2
transported ammonium in an energy-dependent manner. In contrast to transporters
of the AMT1 family, however, AtAMT2 did not transport the ammonium analogue,
methylammonium. AtAMT2 was expressed more highly in shoots than roots and was
subject to nitrogen regulation.
PMID- 10675554
TI - Regulated but not constitutive human respiratory syncytial virus (HRSV) P protein
phosphorylation is essential for oligomerization.
AB - Purified human respiratory syncytial virus (HRSV) P phosphoprotein from
transfected HEp-2 cells is able to oligomerize forming tetramers. The bulk of
constitutive P protein phosphorylation (99. 8%) (serine residues 116, 117, 119,
232 and 237) can be removed without affecting protein oligomerization. However,
dephosphorylated P protein, produced in bacteria, is unable to oligomerize. This
difference can be explained by a transient P protein phosphorylation, detected in
HEp-2 cells, that could be essential for P protein oligomerization.
PMID- 10675555
TI - X-ray crystal structure of the YM210W mutant reaction centre from Rhodobacter
sphaeroides.
AB - The X-ray crystal structure of a reaction centre from Rhodobacter sphaeroides
with a mutation of tyrosine M210 to tryptophan (YM210W) has been determined to a
resolution of 2.5 A. Structural conservation is very good throughout the body of
the protein, with the tryptophan side chain adopting a position in the mutant
complex closely resembling that of the tyrosine in the wild-type complex. The
spectroscopic properties of the YM210W reaction centre are discussed with
reference to the structural data, with particular focus on evidence that the
introduction of the bulkier tryptophan in place of the native tyrosine may cause
a small tilt of the macrocycle of the B(L) monomeric bacteriochlorophyll.
PMID- 10675556
TI - Preferential induction of apoptosis of leukaemic cells by farnesol.
AB - Farnesol preferentially inhibits proliferation and induces apoptosis of tumour
derived but not non-transformed cell lines. We investigated whether farnesol
induces apoptosis of blasts from patients with acute myeloid leukaemia (AML) and
leukaemic cell lines, as compared with normal, human primary haemopoietic cells.
We show that 30 microM farnesol causes apoptosis of leukaemic cell lines of T-
and B-lymphocyte, myeloid or erythroid lineages and primary blasts obtained from
patients with AML. However, the same concentration did not kill primary
monocytes, or quiescent or proliferating T-lymphocytes. We conclude that farnesol
selectively kills AML blasts and leukaemic cell lines in preference to primary
haemopoietic cells.
PMID- 10675557
TI - Isolation of the epithiospecifier protein from oil-rape (Brassica napus ssp.
oleifera) seed and its characterization.
AB - The epithiospecifier protein (ESP) is a myrosinase (MYR) cofactor, which is
necessary to drive the MYR-catalyzed hydrolysis of some specific glucosinolates
towards the production of cyanoepithioalkanes instead of isothiocyanates and
nitriles. ESP was isolated from Brassica napus seeds by anionic exchange and gel
filtration chromatography. ESP showed a molecular weight of about 39 kDa and pI
5.3. The amino acid sequence of several tryptic peptides of ESP (accounting for
about 50% of the total sequence) made it possible to establish the high
similarity (81% identity) with a hypothetical 37 kDa protein (TrEMBL data base
accession number Q39104) and several jasmonate-inducible proteins from
Arabidopsis thaliana. This observation suggests that ESP is likely to be involved
in jasmonate-mediated defence and disease resistance mechanisms.
PMID- 10675558
TI - Identification of syntenin and other TNF-inducible genes in human umbilical
arterial endothelial cells by suppression subtractive hybridization.
AB - Endothelial cells play an important regulatory role in inflammatory responses by
upregulating various proinflammatory gene products including cytokines and
adhesion molecules. A highly potent mediator of this process is tumor necrosis
factor-alpha (TNF). In the present study, the suppression subtractive
hybridization (SSH) method was employed to identify rarely transcribed TNF
inducible genes in human umbilical arterial endothelial cells. Following mRNA
isolation of non-stimulated and TNF-stimulated cells, cDNAs of both populations
were prepared and subtracted by suppression PCR. Sequencing of the enriched cDNAs
identified 12 genes differentially expressed including vascular cell adhesion
molecule-1, monocyte chemoattractant protein-1, interleukin-8 and IkappaBalpha,
an inhibitor of the transcription factor nuclear factor-kappaB. Interestingly,
also syntenin, a PDZ motif-containing protein which binds to the cytoplasmic
domain of syndecans, was identified by SSH. Time course studies using RT-PCR
analysis confirmed that all genes were differentially expressed and rapidly
induced by TNF. Our data reveal that SSH is a powerful technique of high
sensitivity for the detection of differential gene expression in primary arterial
endothelial cells.
PMID- 10675559
TI - Inhibition of plant telomerase by telomere-binding proteins from nuclei of
telomerase-negative tissues.
AB - The activity of telomerase in plant cells is precisely regulated in response to
changes in cell division rate. To explore this regulatory mechanism, the effect
on telomerase activity of protein extracts from nuclei of telomerase-negative
tissues was examined. An inhibition of telomerase activity was found which was
species-non-specific. This inhibition was due to proteins which form salt-stable,
sequence-specific complexes with the G-rich telomeric strand and reduce its
accessibility, as shown by gel retardation and by terminal transferase (TdT)
extension of G-rich telomeric and non-telomeric (substrate) primers. A 40 kDa
polypeptide was detected by SDS-PAGE after cross-linking the complex formed by
extracts from tobacco leaf nuclei. Such proteins may be involved in regulation of
telomerase activity in plants.
PMID- 10675560
TI - The Saccharomyces cerevisiae DNA damage checkpoint is required for efficient
repair of double strand breaks by non-homologous end joining.
AB - In this work we report that the Saccharomyces cerevisiae RAD9, RAD24, RAD17,
MEC1, MEC3 and RAD53 checkpoint genes are required for efficient non-homologous
end joining (NHEJ). RAD9 and RAD24 function additionally in this process.
Defective NHEJ in rad9Delta-rad24Delta, but not yku80Delta cells, is only
partially rescued by imposing G1 or G2/M delays. Thus, checkpoint functions other
than transient cell cycle delays may be required for normal levels of NHEJ.
Epistasis analysis also indicated that YKU80 and RAD9/RAD24 function in the same
pathway for repair of lesions caused by MMS and gamma-irradiation. Unlike NHEJ,
the checkpoint pathway is not required for efficient site-specific integration of
plasmid DNA into the yeast genome, which is RAD52-dependent, but RAD51
independent.
PMID- 10675561
TI - Analysis of the interaction between single-chain variable fragments and their
antigen in a reducing intracellular environment using the two-hybrid system.
AB - The coding sequences of three single-chain variable (scFv) fragments (A4, G4 and
H3), which bind to dihydroflavonol-4-reductase (DFR) of Petunia hybrida, and the
DFR-encoding sequence were cloned in two-hybrid vectors. The vectors were
transformed in the yeast strain HF7c (his3-200, trp1-901, leu2-3) and the scFv
DFR interaction was analyzed by measuring yeast growth on medium without
histidine. ScFv-G4 and, to a lesser extent, scFv-A4 could interact with DFR in
the yeast nucleus. On the contrary, scFv-H3 showed no interaction with its
antigen in yeast. The results of a previous expression analysis of the same scFv
fragments in the plant cytosol correlate with those of the two-hybrid test. This
suggests that it is possible to evaluate the antigen-scFv interaction in a
reducing subcellular environment with the two-hybrid test. Therefore, the yeast
two-hybrid system can be useful to identify candidate scFv fragments for
intracellular antibody applications.
PMID- 10675562
TI - A novel target of lithium therapy.
AB - Phosphatases converting 3'-phosphoadenosine 5'-phosphate (PAP) into adenosine 5'
phosphate are of fundamental importance in living cells as the accumulation of
PAP is toxic to several cellular systems. These enzymes are lithium-sensitive and
we have characterized a human PAP phosphatase as a potential target of lithium
therapy. A cDNA encoding a human enzyme was identified by data base screening,
expressed in Escherichia coli and the 33 kDa protein purified to homogeneity. The
enzyme exhibits high affinity for PAP (K(m)<1 microM) and is sensitive to
subtherapeutic concentrations of lithium (IC(50)=0.3 mM). The human enzyme also
hydrolyzes inositol-1, 4-bisphosphate with high affinity (K(m)=0.4 microM),
therefore it can be considered as a dual specificity enzyme with high affinity
(microM range) for both PAP and inositol-1,4-bisphosphate. Hydrolysis of inositol
1,4-bisphosphate was also inhibited by lithium (IC(50)=0.6 mM). Thus, we present
experimental evidence for a novel target of lithium therapy, which could explain
some of the side effects of this therapy.
PMID- 10675563
TI - Phospholipase D2: functional interaction with caveolin in low-density membrane
microdomains.
AB - Low-density detergent-insoluble membrane domains contain caveolin-1 and are
enriched in a phospholipase D activity that is not PLD1. Here we show that
caveolin-rich fractions, prepared from HaCaT human keratinocytes by either
detergent-based or detergent-free methods, contain PLD2. Caveolar membrane PLD
activity is stimulated 2-fold by low concentrations (10-30 microM) of the
caveolin-1 and caveolin-2 scaffolding domain peptides, whereas it is inhibited at
higher concentrations of the peptides. Immunoisolated HA-tagged PLD1 and PLD2 are
not stimulated by the peptides, although both enzymes retain sensitivity to their
inhibitory effect. Down-regulation of caveolin-1 expression by treatment of the
cells with acetyl-leucyl-leucyl-norleucinal decreased caveolar PLD activity by
50%. Similarly, expression of an active form of the sterol regulatory element
binding protein (SREBP(1-490)) down-regulated caveolin-1 expression by 50% and
decreased caveolar PLD activity by 60%. These data identify the PLD activity in
caveolin-rich membranes as PLD2 and provide in vivo evidence suggesting that
caveolin-1 regulates PLD2 activity.
PMID- 10675564
TI - Characterization of a novel endopolygalacturonase from Aspergillus niger with
unique kinetic properties.
AB - We isolated and characterized a new type of endopolygalacturonase (PG)-encoding
gene, pgaD, from Aspergillus niger. The primary structure of PGD differs from
that of other A. niger PGs by a 136 amino acid residues long N-terminal
extension. Biochemical analysis demonstrated extreme processive behavior of the
enzyme on oligomers longer than five galacturonate units. Furthermore, PGD is the
only A. niger PG capable of hydrolyzing di-galacturonate. It is tentatively
concluded that the enzyme is composed of four subsites. The physiological role of
PGD is discussed.
PMID- 10675565
TI - Molecular cloning of Drosophila gamma-glutamylcysteine synthetase by functional
complementation of a yeast mutant.
AB - gamma-Glutamylcysteine synthetase (GCS) catalyses a critical, rate-limiting step
in glutathione synthesis. In this study we describe the isolation and
characterisation of a GCS cDNA (pDmGCS4.3. 3) from Drosophila melanogaster by
functional complementation of a Saccharomyces cerevisiae gsh1 mutant. Expression
of pDmGCS4.3.3 in the yeast mutant partially restored glutathione levels and
conferred resistance to methylglyoxal. The pDmGCS4.3.3 cDNA was found to be
approx. 4.6 kb in length, containing a 2 kb fragment encoding an open reading
frame with a high degree of deduced amino acid sequence identity with previously
reported GCS sequences. In situ hybridisation revealed that the Drosophila GCS
gene maps to 7D6-9 on the X chromosome.
PMID- 10675566
TI - A GATA binding site is involved in the regulation of 15-lipoxygenase-1 expression
in human colorectal carcinoma cell line, caco-2.
AB - The data presented implicate a GATA binding site in the transcriptional
regulation of 15-lipoxygenase-1 (15-LO-1) gene expression in human colorectal
carcinoma Caco-2 cells. High expression of GATA-6 mRNA and protein was observed,
while GATA-4 mRNA was expressed at a very low level in Caco-2 cells. The
expression of GATA-6 was down-regulated, while 15-LO-1 expression was
dramatically up-regulated after treatment with sodium butyrate (NaBT). A study
using an electrophoretic mobility shift assay indicated that a GATA binding site
of the 15-LO-1 promoter region binds to GATA proteins present in both
undifferentiated and, to a lesser extent, NaBT-treated (differentiated) Caco-2
cells. Moreover, that DNA binding shift band was disrupted after the addition of
GATA-6 antibody in a supershift assay in the absence of NaBT, suggesting that
GATA-6 is bound to the GATA binding site of the 15-LO-1 promoter in
undifferentiated cells. In contrast, the addition of GATA-6 antibody did not
affect the DNA binding ability in NaBT-induced differentiated cells. On the other
hand, mutation of the GATA site of the 15-LO-1 promoter decreased the
transactivation of the 15-LO-1 promoter as measured by luciferase activity in
both FBS and NaBT cultured cells, indicating an unknown GATA binding protein to
up-regulate 15-LO-1 expression. These implicate the GATA site at -240 of the
proximal region of the 15-LO-1 promoter in the basic transcription of 15-LO-1
gene expression in Caco-2 cells, with GATA-6 acting to repress 15-LO-1
expression.
PMID- 10675568
TI - The monomeric polypeptide comprises the functional flavanone 3beta-hydroxylase
from Petunia hybrida.
AB - Flavanone 3beta-hydroxylase catalyzes the Fe(II)/oxoglutarate-dependent
hydroxylation of (2S)-flavanones to (2R,3R)-dihydroflavonols in the biosynthesis
of flavonoids, catechins and anthocyanidins. The enzyme had been partially
purified from Petunia hybrida and proposed to be active as a dimer of roughly 75
kDa in size. More recently, the Petunia 3beta-hydroxylase was cloned and shown to
be encoded in a 41655 Da polypeptide. In order to characterize the molecular
composition, the enzyme was expressed in a highly active state in Escherichia
coli and purified to apparent homogeneity. Size exclusion chromatographies of the
pure, recombinant enzyme revealed that this flavanone 3beta-hydroxylase exists in
functional monomeric and oligomeric forms. Protein cross-linking experiments
employing a specific homobifunctional sulfhydryl group reagent or the
photochemical activation of tryptophan residues confirmed the tendency of the
enzyme to aggregate to oligomeric complexes in solution. Thorough equilibrium
sedimentation analyses, however, revealed a molecular mass of 39. 2+/-12 kDa for
the recombinant flavanone 3beta-hydroxylase. The result implies that the
monomeric polypeptide comprises the catalytically active flavanone 3beta
hydroxylase of P. hybrida, which may readily associate in vivo with other
proteins.
PMID- 10675567
TI - A family of ubiquitin-like proteins binds the ATPase domain of Hsp70-like Stch.
AB - We have isolated two human ubiquitin-like (UbL) proteins that bind to a short
peptide within the ATPase domain of the Hsp70-like Stch protein. Chap1 is a
duplicated homologue of the yeast Dsk2 gene that is required for transit through
the G2/M phase of the cell cycle and expression of the human full-length cDNA
restored viability and suppressed the G2/M arrest phenotype of dsk2Delta
rad23Delta Saccharomyces cerevisiae mutants. Chap2 is a homologue for Xenopus
scythe which is an essential component of reaper-induced apoptosis in egg
extracts. While the N-terminal UbL domains were not essential for Stch binding,
Chap1/Dsk2 contains a Sti1-like repeat sequence that is required for binding to
Stch and is also conserved in the Hsp70 binding proteins, Hip and p60/Sti1/Hop.
These findings extend the association between Hsp70 members and genes encoding
UbL sequences and suggest a broader role for the Hsp70-like ATPase family in
regulating cell cycle and cell death events.
PMID- 10675569
TI - The polyomavirus major capsid protein VP1 interacts with the nuclear matrix
regulatory protein YY1.
AB - Polyomavirus reaches the nucleus in a still encapsidated form, and the viral
genome is readily found in association with the nuclear matrix. This association
is thought to be essential for viral replication. In order to identify the
protein(s) involved in the virus-nuclear matrix interaction, we focused on the
possible roles exerted by the multifunctional cellular nuclear matrix protein Yin
Yang 1 (YY1) and by the viral major capsid protein VP1. In the present work we
report on the in vivo association between YY1 and VP1. Using the yeast two-hybrid
system we demonstrate that the VP1 and YY1 proteins physically interact through
the D-E region of VP1 and the activation domain of YY1.
PMID- 10675571
TI - Corrigendum to: conservation of the central proline-rich (PxxP) motifs of human
immunodeficiency virus type 1 nef protein during the disease progression in two
hemophiliac patients (FEBS 22727).
PMID- 10675572
TI - Early CT changes of ischemia: limitations of what we know.
PMID- 10675573
TI - Heparin and oral anticoagulants in the treatment of brain ischemia.
AB - The use of heparin, heparin analogues, and oral anticoagulation in the treatment
of brain ischemia remains controversial. We review the mechanism of action of the
heparins and warfarin as well as the data regarding their efficacy and
complications in patients with ischemic stroke and venous sinus thrombosis. None
of these drugs have proven effective for all forms of cerebral ischemia. Further
studies examining the efficacy of anticoagulants in different stroke subgroups
will be necessary in order to clarify optimal clinical practice.
PMID- 10675574
TI - Computed tomography findings in the first few hours of ischemic stroke:
implications for the clinician.
AB - In order to evaluate the clinical usefulness of emergency computed tomography
(CT) in acute ischemic stroke, we assessed whether CT findings within the first
few hours of stroke onset reliably predict type, site and size of the index
infarction, and risk of death or disability. For this reason we reviewed clinical
and CT findings in a cohort of unselected consecutive patients referred to the
stroke unit of a large urban hospital because of a presumed ischemic stroke in
the anterior circulation (AC), and submitted to CT within 5 h from onset. Out of
158 total patients, emergency CT revealed parenchymal changes compatible with AC
focal ischemia in 77 (49%) and a hyperdense middle cerebral artery (MCA) in 41
(26%). Parenchymal changes and hyperdense MCA predicted an AC territorial
infarction respectively in 97% of cases (95% C.I. 93% to 100%) and in 95% of
cases (95% C.I. 88% to 100%). Site and size of early changes coincided with those
of final lesions in 79% of patients with cortical changes and in 95% of patients
with cortico-subcortical changes, but only in 37% of patients with initial
subcortical changes, the remainder of whom developed a cortico-subcortical
infarction. At logistic regression parenchymal changes were the only independent
predictor of an AC territorial infarction. Negative predictive power, however,
was only 40% (95% C. I. 29% to 51%) for parenchymal changes, and 35% for
hyperdense MCA (95% C.I. 26% to 44%). The odds for death or disability at 1 month
associated with parenchymal changes were thrice as high as with negative CT, even
after adjustment for clinical severity on admission. These results indicate that
CT scan adds significantly to the prediction of outcome made on clinical grounds.
The frequent development of a territorial infarction in patients with initially
negative CT and the subsequent recruitment of the cortex in those initially
exhibiting only subcortical changes suggest that the transition from ischemia to
infarction often occurs after the first five h following stroke.
PMID- 10675575
TI - Medial temporal atrophy and memory impairment in early stage of Alzheimer's
disease: an MRI volumetric and memory assessment study.
AB - Memory impairment and medial temporal lobe (MTL) involvement are the earliest and
most prominent features of Alzheimer's disease (AD). A psychological assessment
of memory function and an evaluation of the morphological changes in MTL
structures, as found in the mild form of AD, are important for early diagnosis as
well as for understanding the pathophysiology of the disease. In the present
study, we aimed to evaluate correlations in these psychoanatomical changes in
terms of the stage of AD. We performed MRI-based volumetric measurements of the
MTL structure and neuropsychological tests, using MMSE and the Wechsler memory
scale-revised (WMS-R), on 27 elderly normal subjects and 46 probable AD patients,
and then checked for possible correlations between the volumetric measurements
and memory dysfunction. The severity of the AD patients' condition was assessed
by CDR scale. Each MTL structure decreased in volume with increasing severity of
AD. In very early AD, the reduction in the amygdala volume was pronounced, while
the hippocampal volumes were relatively unchanged. Neuropsychological scores also
declined with increasing severity of AD. Scores on the main WMS-R subsets
examined (verbal memory, visual memory, and delayed recall) decreased
significantly in the very mild group, as compared with normal controls. The WMS-R
test scores correlated significantly with the amygdala volumes in normal control
subjects and very mild AD patients. Our findings suggest that MRI-based
amygdaloid volumetric measurement provides a sensitive marker, and that the
degeneration of the amygdala may begin very early in the course of AD.
PMID- 10675576
TI - Serial positron emission tomography (PET) in gliomatosis cerebri treated with
radiotherapy: a case report.
AB - Results of serial positron emission tomography (PET) in a biopsy-proven case of
gliomatosis cerebri (GC) are reported. Computed tomography (CT) with and without
contrast failed to detect focal abnormalities, but magnetic resonance (MR)
revealed iso-intensity or low-intensity lesions in T1-weighted images and high
intensity lesions in T2-weighted images. Lesions were seen in the left thalamus,
right temporal lobe and claustrum, and pons. Radiotherapy remarkably improved
clinical and imaging findings. Both before and shortly after radiotherapy, 11C
methionine PET images showed hypermetabolism while 15O-water PET images showed a
marked increase in cerebral blood flow in GC lesions. However, 6 months later PET
images had remarkably improved, appearing nearly normal.
PMID- 10675577
TI - Epstein-Barr virus nuclear antigen-1 (EBNA-1) associated oligoclonal bands in
patients with multiple sclerosis.
AB - Oligoclonal bands (OCBs) are frequently observed in the cerebrospinal fluid (CSF)
of patients with multiple sclerosis (MS), but the target antigens of these
antibodies remain unknown. We used antigen specific immunoblotting to determine
whether Epstein Barr virus nuclear antigen-1 (EBNA-1) was a target of the OCBs in
the CSF of patients with MS. Antibody indices (AIs) were measured by ELISA and
calculated by the formula of Reiber and Lange which includes correction factors
for both breakdown of the blood brain barrier and intrathecal polyclonal IgG
synthesis. A distinctive oligoclonal antigen specific banding pattern for EBNA-1
was observed in 5/15 MS patients, but 0/12 controls (P=0.037, Fisher's Exact
Probability). AIs in this EBNA-l positive subgroup were extremely high,
comparable with levels observed in viral CNS infections. In one patient with EBNA
1 specific OCBs, EBNA-1 and a peptide 'equivalent', p62, were able to absorb a
component of the total IgG. Our results suggest that in a subset of MS patients,
EBNA-1 may be a major target of selected OCBs.
PMID- 10675578
TI - Changes in uptake of vitamin B(12) and trace metals in brains of mice treated
with clioquinol.
AB - Clioquinol is a hydroxyquinoline antibiotic that has been associated with severe
side-effects in the CNS. The syndrome caused by clioquinol treatment, subacute
myelo-optic neuropathy (SMON), is considered as one of the worst drug disasters
of this century. The precise biochemical mechanism behind SMON is not fully
understood. Clioquinol can form strong lipophilic chelates with divalent cations
and therefore it has been speculated that the drug may disturb the retention of
vitamin B(12) through chelation of Co(2+). In the present study, the tissue
distribution and uptake capacity of [57Co]cyanocobalamin were estimated in mice
treated with clioquinol or saline. The concentrations of some trace metals were
also determined in brain tissue. Accumulation of vitamin B(12) in the brain and
its concentration in blood were decreased by clioquinol treatment. The mean
concentrations of several trace metals were also lowered in the brain while the
concentration of cobalt in the brain was not affected, suggesting that clioquinol
does not bind to the cobalt in vitamin B(12). Moreover, a significant decrease in
the levels of S-adenosylmethionine (SAM) was observed in the brain after
clioquinol treatment. This may be a consequence of decreased vitamin B(12)
levels. From these results, it can be concluded that chronic treatment with
clioquinol may alter the tissue homeostasis of vitamin B(12) in the brain.
PMID- 10675579
TI - Marked increase of matrix metalloproteinase 9 in cerebrospinal fluid of patients
with fungal or tuberculous meningoencephalitis.
AB - Matrix metalloproteinases (MMPs) are believed to play an essential role in the
breakdown of the extracellular matrix macromolecules in the blood-cerebrospinal
fluid barrier and blood-brain barrier (BBB). In this study, the levels of MMP-2
and MMP-9 and their common tissue inhibitors of metalloproteinases (TIMP-1 and
TIMP-2) were measured in the cerebrospinal fluid (CSF) from patients with various
meningitides including aseptic, fungal and tuberculous ones. MMP-9 production
level in CSF was more increased in subacute meningitis including fungal and
tuberculous meningitis than in acute aseptic meningitis and non-inflammatory
neurological diseases (NIDs). Enhanced production of MMP-9 was associated with
high proteolytic activity detected by gelatin zymography. The MMP-2 and TIMP-1
levels in CSF of subacute meningitis were also higher than those of NIDs. In
contrast, the TIMP-2 levels in CSF of either acute aseptic or subacute meningitis
were not up-regulated compared with those of NIDs. The central nervous system
(CNS) complications (i.e. disturbance of consciousness, psychiatric symptoms,
urinary disturbance, etc.) during the course of meningitis showed good
correlation with the enhanced production of MMP-9 in CSF. Immunohistochemical
studies in tuberculous meningitis demonstrated that the infiltrating mononuclear
cells in the meninges were immunoreactive for both MMP-2 and MMP-9. However, the
infiltrating mononuclear cells into CNS parenchyma had immunoreactivity for MMP
9, but not for MMP-2. Taken together, those data suggest that MMP-9 in CSF may be
a useful marker of encephalitogenecity during the course of subacute meningitis.
PMID- 10675580
TI - Aggregation of ubiquitin and a mutant ALS-linked SOD1 protein correlate with
disease progression and fragmentation of the Golgi apparatus.
AB - Transgenic mice that express the G93A mutation of human Cu,Zn superoxide
dismutase (SOD1(G93A)), found in familial amyotrophic lateral sclerosis (FALS),
showed clinical symptoms and histopathological changes of sporadic ALS, including
fragmentation of the neuronal Golgi apparatus (GA). The finding of fragmented
neuronal GA in asymptomatic mice, months before the onset of paralysis, suggests
that the GA is an early target of the pathological processes causing neuronal
degeneration. Transgenic mice expressing human SOD1(G93A) have aggregates of
mutant protein and ubiquitin in neuronal and glial cytoplasm; they appeared first
in the neuropil and later in the perikarya of motor neurons, where they were
adjacent to fragmented GA. The aggregates of SOD1(G93A) appeared in neuronal
perikarya of asymptomatic mice containing fragmented GA. The numbers of neurons
with deposits of SOD1(G93A) and fragmented GA progressively increased with age.
Immuno-electron microscopy using colloidal gold showed labeling of ubiquitin and
SOD1 over 13 nm thick cytoplasmic filaments. Spinal cord extracts showed a 20
fold increase of SOD1(G93A) in transgenic mice compared to the wild-type protein
in controls. The results suggest a causal relationship between the aggregation of
mutant SOD1 and ubiquitin, fragmentation of the Golgi apparatus of motor neurons
and neurodegeneration.
PMID- 10675581
TI - The neuronal Golgi apparatus is fragmented in transgenic mice expressing a mutant
human SOD1, but not in mice expressing the human NF-H gene.
AB - Fragmentation of the Golgi apparatus (GA) of motor neurons was first described in
sporadic amyotrophic lateral sclerosis (ALS) and later confirmed in transgenic
mice expressing the G93A mutation of the gene encoding the enzyme Cu,Zn
superoxide dismutase (SOD1(G93A)) found in some cases of familial ALS. In these
transgenic mice, however, the fragmentation of the neuronal GA was associated
with cytoplasmic and mitochondrial vacuoles not seen in ALS. The present new
series of transgenic mice expressing 14-17 trans gene copies of SOD1(G93A),
compared to 25 copies in the mice we studied previously, showed consistent
fragmentation of the GA of spinal cord motor neurons, axonal swellings, Lewy-like
body inclusions in neurons and glia, but none of the cytoplasmic or mitochondrial
vacuoles originally reported. Thus, this animal model recapitulates the clinical
and most neuropathological findings of sporadic ALS. Neurofilaments (NF)
accumulate in axons and, less often, in neuronal perikarya in most cases of
sporadic ALS and they have been implicated in its pathogenesis. In order to
investigate whether fragmentation of the neuronal GA also occurs in association
with accumulation of perikaryal NFs, we studied the organelle in transgenic mice
expressing the heavy subunit of human neurofilaments (NF-H) which developed a
motor neuronopathy resembling ALS. The neuronal GA of mice expressing NF-H,
however, was intact despite massive accumulation of NFs in both perikarya and
axons of motor neurons. In contrast, in transgenic mice expressing SOD1(G93A),
the GA was fragmented despite the absence of accumulation of perikaryal NFs.
These findings suggest that, in transgenic mice with neuronopathies caused by the
expression of mutant SOD1(G93A) or the human NF-H, the GA and the perikaryal NFs
are independently involved in the pathogenesis. The evidence suggests that the GA
plays a central role in the pathogenesis of the vast majority of sporadic ALS and
in FALS with SOD1 mutations.
PMID- 10675582
TI - The effect of oral and intravenous methylprednisolone treatment on subsequent
relapse rate in multiple sclerosis.
AB - We investigated the effect of oral and intravenous methylprednisolone treatment
on subsequent relapse rate in patients with multiple sclerosis. Following a
double blind trial designed to compare the effect of oral and intravenous
methylprednisolone treatment on promoting recovery from acute relapses of
multiple sclerosis, 80 patients were followed for two years with six-monthly
assessments during which all subsequent relapses were recorded. The annual
relapse rate was slightly higher in the oral compared with the intravenous
methylprednisolone-treated patients (1.06 vs. 0.78), but the adjusted difference
between the two groups was not statistically significant (0.18; 95% CI -0.19 to
0.55, P=0.3). The time to onset and the severity of the first relapse after
treatment, the number of relapse free patients at the end of the follow-up
period, and the severity of the relapses during the follow-up period were similar
in the two groups. This trial did not show a statistically significant difference
in relapse rate during the first two years following oral compared with
intravenous methylprednisolone treatment.
PMID- 10675583
TI - Neuromyotonia in association with essential thrombocythemia.
PMID- 10675584
TI - Hyaluronidases of Gram-positive bacteria.
AB - Bacterial hyaluronidases, enzymes capable of breaking down hyaluronate, are
produced by a number of pathogenic Gram-positive bacteria that initiate
infections at the skin or mucosal surfaces. Since reports of the hyaluronidases
first appeared, there have been numerous suggestions as to the role of the enzyme
in the disease process. Unlike some of the other more well studied virulence
factors, much of the information on the role of hyaluronidase is speculative,
with little or no data to substantiate proposed roles. Over the last 5 years, a
number of these enzymes from Gram-positive organisms have been cloned, and the
nucleotide sequence determined. Phylogenetic analysis, using the deduced amino
acid sequences of the Gram-positive hyaluronidases, suggests a relatedness among
some of the enzymes. Molecular advances may lead to a more thorough understanding
of the role of hyaluronidases in bacterial physiology and pathogenesis.
PMID- 10675585
TI - Chlorobiphenyl-desleucyl-vancomycin inhibits the transglycosylation process
required for peptidoglycan synthesis in bacteria in the absence of dipeptide
binding.
AB - Novel glycopeptide analogs are known that have activity on vancomycin resistant
enterococci despite the fact that the primary site for drug interaction, D-ala-D
ala, is replaced with D-ala-D-lactate. The mechanism of action of these compounds
may involve dimerization and/or membrane binding, thus enhancing interaction with
D-ala-D-lactate, or a direct interaction with the transglycosylase enzymes
involved in peptidoglycan polymerization. We evaluated the ability of vancomycin
(V), desleucyl-vancomycin (desleucyl-V), chlorobiphenyl-vancomycin (CBP-V), and
chlorobiphenyl-desleucyl-vancomycin (CBP-desleucyl-V) to inhibit (a)
peptidoglycan synthesis in vitro using UDP-muramyl-pentapeptide and UDP-muramyl
tetrapeptide substrates and (b) growth and peptidoglycan synthesis in vancomycin
resistant enterococci. Compared to V or CBP-V, CBP-desleucyl-V retained
equivalent potency in these assays, whereas desleucyl-V was inactive. In
addition, CBP-desleucyl-V caused accumulation of N-acetylglucosamine-beta-1, 4
MurNAc-pentapeptide-pyrophosphoryl-undecaprenol (lipid II). These data show that
CBP-desleucyl-V inhibits peptidoglycan synthesis at the transglycosylation stage
in the absence of binding to dipeptide.
PMID- 10675586
TI - Regulation of aflatoxin production by Ca(2+)/calmodulin-dependent protein
phosphorylation and dephosphorylation.
AB - To elucidate Ca(2+)-mediated regulation of aflatoxin production, the status of
Ca(2+)/calmodulin-dependent protein phosphorylation and dephosphorylation was
investigated employing toxigenic and non-toxigenic strains of Aspergillus
parasiticus. Incubation of cytoplasmic extracts with [gamma-(32)P]ATP followed by
SDS-PAGE and autoradiography revealed total absence of protein phosphorylation
during periods corresponding to aflatoxin production in the toxigenic strain
(NRRL 2999). In contrast, protein phosphorylation was unaffected in the non
toxigenic strain (SRRC 255). Aflatoxin production in the toxigenic strain was
also accompanied by enhanced (26-fold) activity of calcineurin (calmodulin
dependent protein phosphatase 2B) concomitant with a lowered (6-fold) activity of
calmodulin-dependent protein kinase. In addition, the in vitro activity of
Ca(2+)/calmodulin-dependent protein kinase was susceptible to dose-dependent
inhibition by aflatoxin. Since calcineurin remains active in the absence of
phosphorylation by calmodulin-dependent protein kinase, it is suggested that
calcineurin-mediated dephosphorylation of regulatory enzymes ensures continued
production of aflatoxins.
PMID- 10675587
TI - Conserved tyr residues determine functions of Alicyclobacillus acidocaldarius
squalene-hopene cyclase.
AB - The catalytic cavity of Alicyclobacillus acidocaldarius squalene-hopene cyclase
is mainly lined by aromatic amino acids. In recombinant cyclases, three out of
four tyrosine residues (Y) have been mutated to phenylalanine residues (F). The
mutant cyclases Y495F and Y612F had less activity than the wild-type cyclase, but
a wild-type product pattern. Mutant Y609F had wild-type activity but a
drastically altered product pattern with hopene and significant amounts of
bicyclic alpha-polypodatetraene and different tetracyclic triterpenes
(dammaradienes and eupha-7,24-diene). The experiments demonstrated that Y495 and
Y612 may be involved in the initiation of the cyclization reaction and Y609 in
the stabilization and/or positioning of the intermediate carbocations.
PMID- 10675588
TI - Separation of NADH-fumarate reductase and succinate dehydrogenase activities in
Trypanosoma cruzi.
AB - A recent review suggested that the activity of NADH-fumarate reductase from
trypanosomatids could be catalyzed by succinate dehydrogenase working in reverse
(Tielens and van Hellemond, Parasitol. Today 14, 265-271, 1999). The results
reported in this study demonstrate that the two activities can easily be
separated without any loss in either activity, suggesting that fumarate reductase
and succinate dehydrogenase are separate enzymes.
PMID- 10675589
TI - Expression of green fluorescent protein in Lactococcus lactis.
AB - The gfp gene from Aequorea victoria, encoding the green fluorescent protein (GFP)
has been expressed in Lactococcus lactis subsp. lactis biovar cremoris MG1363,
upon construction and introduction of plasmid pLS1GFP into this host. GFP was
monitored in living cells during growth to evaluate its use in molecular and
physiological studies. Quantification of the levels of GFP expressed by cultures
was feasible by fluorescence spectroscopy. Phase-contrast and fluorescence
microscopy allowed us to distinguish, in mixed cultures, lactococcal cells
expressing GFP. Our results indicate that GFP can be used as a reporter in L.
lactis.
PMID- 10675590
TI - Relationships between the anti-HIV V(3)-derived peptide SPC(3) and lymphocyte
membrane properties involved in virus entry: SPC(3) interferes with CXCR(4).
AB - SPC(3) is a multiple antigen peptide derived from the V(3) loop of human
immunodeficiency virus (HIV) envelope (Env). It exerts a potent anti-HIV activity
whereas it alters neither Env expression nor binding to CD(4). Here, SPC(3)
binding characteristics, its subsequent intracellular fate and the fact that it
inhibited SDF(1)alpha binding to the lymphocyte surface provided strong arguments
to conclude that it exerts its anti-HIV activity through interference with the
CXCR(4) coreceptor. In contrast, it interferes with none of the other major
surface proteins and mechanisms involving V(3) and implicated in infection, as
shown here. This work identifies the target mechanism of SPC(3).
PMID- 10675591
TI - Identification and molecular analysis of superoxide dismutase isoforms in
Helicobacter pylori.
AB - Three electromorphs of iron superoxide dismutase (FeSOD) were identified among 29
Helicobacter pylori isolates by native gel electrophoresis and activity staining.
The electromorphs designated isoforms A, B, and C are characterized by slow,
intermediate and fast electrophoretic migration, respectively, which was not
observed under denaturing conditions. The isoforms were not associated with
virulence determinants and with the outcome of disease. Sequence analysis of the
sodB gene in strains producing different FeSOD isoforms and comparison of deduced
protein sequences revealed that differences in the electric migration behavior
are associated with exchange of charged amino acids, suggesting that faster
migration is caused by a more negative total charge of the proteins.
Electrophoretic migration of native FeSOD was not influenced by changes in the
iron cofactor concentration, oxidative stress, and different media, indicating
that FeSOD isoforms represent stable strain-specific markers.
PMID- 10675593
TI - In vitro transcription system using reconstituted RNA polymerase (Esigma(70),
Esigma(H), Esigma(E) and Esigma(S)) of Pseudomonas aeruginosa.
AB - We have developed an in vitro transcription system for Pseudomonas aeruginosa
genes, using RNA polymerase (RNAP) holoenzyme reconstituted with purified sigma
protein and RNAP core enzyme. The RNAP core enzyme was directly purified from P.
aeruginosa PAO1 cells. The sigma factors of P. aeruginosa (sigma(70), sigma(H),
sigma(E) and sigma(S)) were prepared in a hexa-histidine tagged form, which were
expressed in Escherichia coli and purified using a HisTrap Chelating column. The
RNAP holoenzyme reconstituted from core enzyme with each sigma factor recognized
correctly each of the cognate promoters. This system will be useful for the
promoter analysis of many genes in P. aeruginosa.
PMID- 10675592
TI - The Bacillus subtilis ctaB paralogue, yjdK, can complement the heme A synthesis
deficiency of a CtaB-deficient mutant.
AB - Heme A is a prosthetic group in many respiratory oxidases. It is synthesised from
heme B (protoheme IX) with heme O as an intermediate. In Bacillus subtilis two
genes required for heme A synthesis, ctaA and ctaB, have been identified. CtaB is
the heme O synthase and CtaA is involved in the conversion of heme O to heme A. A
ctaB paralogue, yjdK, has been identified through the B. subtilis genome
sequencing project. In this study we show that when carried on a low copy number
plasmid, the yjdK gene can complement a ctaB deletion mutant with respect to heme
A synthesis. Our results indicate that YjdK has heme O synthase activity. We
therefore suggest that yjdK be renamed as ctaO.
PMID- 10675594
TI - Aldolases of the DhnA family: a possible solution to the problem of pentose and
hexose biosynthesis in archaea.
AB - Sequence analysis of the recently identified class I aldolase of Escherichia coli
(dhnA gene product) helped to identify its homologs in Chlamydia trachomatis,
Chlamydiophyla pneumoniae and in each of the completely sequenced archaeal
genomes. Iterative database searches revealed sequence similarities between the
DhnA-family enzymes, deoxyribose phosphate aldolases and bacterial (class II)
fructose bisphosphate aldolases and allowed prediction of similar three
dimensional structures (TIM-barrel fold) in all these enzymes. The Schiff base
forming lysyl residues of DhnA and deoxyribose phosphate aldolase are conserved
in all members of the DhnA and deoxyribose phosphate aldolase families,
indicating that these enzymes share common features with both class I and class
II aldolases. The DhnA-family enzymes are predicted to possess an aldolase
activity and to play a critical role in sugar biosynthesis in archaea.
PMID- 10675595
TI - Mannanase Man26A from Cellulomonas fimi has a mannan-binding module.
AB - A modular mannanase (Man26A) from the bacterium Cellulomonas fimi contains a
mannan-binding module (Man26Abm) that binds to soluble but not to insoluble
mannans. Man26Abm does not bind to cellulose, chitin or xylan. The K(d) for
binding of Man26Abm to locust bean gum (LBG) is approximately 0.2 microM. Man26A
is the first mannanase reported to contain a mannan-binding module.
PMID- 10675596
TI - Plasmid curing from an acidophilic bacterium of the genus Acidocella.
AB - Preservation of the acidophilic heterotroph, Acidocella sp. strain GS19h, at 4
degrees C in stab culture eliminated all indigenous plasmids from this bacterium.
Growth at 42 degrees C initially caused changes in the plasmid profile followed
by total elimination of plasmids after 10 cycles of growth. Concomitant to this
loss of all plasmids, the cured derivatives became sensitive to CdSO(4) and
ZnSO(4), and the MIC value of the salts dropped from 1 M for each in the case of
parental strain to 2 mM and 5 mM, respectively, suggesting plasmid-mediated
inheritance of metal resistance in this bacterium. The cured derivatives could
not utilise lactose, indicating this metabolic activity to be plasmid-associated
in this strain.
PMID- 10675597
TI - Detection of genes for membrane-bound nitrate reductase in nitrate-respiring
bacteria and in community DNA.
AB - A nested PCR primed by four degenerate oligonucleotides was developed for the
specific amplification of sequences from the narG gene encoding the membrane
bound nitrate reductase. This approach was used to amplify fragments of the narG
gene from five Pseudomonas species previously shown to be able to express the
membrane-bound nitrate reductase and from community DNA extracted from a
freshwater sediment. Amino acid sequences encoded by the narG fragments were
compared to one another, and to the corresponding regions of related enzymes.
This comparison indicates that the amplification protocols are specific for their
intended targets. Sequences amplified from community DNA were tightly clustered,
which may indicate a degree of homogeneity in the sediment community. The PCR
primers and amplification protocols described will be useful in future studies of
nitrate respiring populations.
PMID- 10675598
TI - Cloning, over-expression and purification of Pseudomonas aeruginosa murC encoding
uridine diphosphate N-acetylmuramate: L-alanine ligase.
AB - We cloned and sequenced the murC gene from Pseudomonas aeruginosa encoding a
protein of 53 kDa. Multiple alignments with 20 MurC peptide sequences from
different bacteria confirmed the presence of highly conserved regions having
sequence identities ranging from 22-97% including conserved motifs for ATP
binding and the active site of the enzyme. Genetic complementation was done in
Escherichia coli (murCts) suppressing the lethal phenotype. The murC gene was
subcloned into the expression vector pET30a and overexpressed in E. coli
BL21(lambdaDE3). Three PCR cloning strategies were used to obtain the three
recombinant plasmids for expression of the native MurC, MurC His-tagged at N
terminal and at C-terminal, respectively. MurC His-tagged at C-terminal was
chosen for large scale production and protein purification in the soluble form.
The purification was done in a single chromatographic step on an affinity nickel
column and obtained in mg quantities at 95% homogeneity. MurC protein was used to
produce monoclonal antibodies for epitope mapping and for assay development in
high throughput screenings. Detailed studies of MurC and other genes of the
bacterial cell cycle will provide the reagents and strain constructs for high
throughput screening and for design of novel antibacterials.
PMID- 10675599
TI - The Yersinia high-pathogenicity island is present in different members of the
family Enterobacteriaceae.
AB - A pathogenicity island termed high-pathogenicity island (HPI) is present in
pathogenic Yersinia. This 35 to 45 kb island carries genes involved in synthesis,
regulation and transport of the siderophore yersiniabactin. Recently, the HPI was
also detected in various strains of Escherichia coli. In this study, the
distribution of the HPI in the family Enterobacteriaceae was investigated. Among
the 67 isolates pertaining to 18 genera and 52 species tested, nine (13.4%)
harbored the island. These isolates were three E. coli, one Citrobacter diversus
and five Klebsiella of various species (Klebsiella pneumoniae, Klebsiella
rhinoscleromatis, Klebsiella ozaenae, Klebsiella planticola, and Klebsiella
oxytoca). As in Yersinia sp., all nine isolates synthesized the HPI-encoded iron
repressible proteins HMWP1 and HMWP2. In the K. oxytoca strain, the right-end
portion of the HPI was deleted, whereas the entire core region of the island was
present in the eight other enterobacteria strains analyzed. In most of these
isolates, the HPI was bordered by an asn tRNA locus, as in Yersinia sp. This
report thus demonstrates the spread of the HPI among various members of the
family Enterobacteriaceae.
PMID- 10675600
TI - Bacterial triterpenoids of the hopane series as biomarkers for the chemotaxonomy
of Burkholderia, Pseudomonas and Ralstonia spp.
AB - Hopanoid fingerprints allowed to differentiate bacteria formerly connected to the
genus Pseudomonas. Whereas all strains related to Pseudomonas and Ralstonia were
devoid of any detectable hopanoid, these pentacyclic triterpenoids were found in
the Burkholderia species and in related soil isolates, which contained as main
hopanoid a bacteriohopanetetrol carbapseudopentose ether, accompanied by
significant amounts of its novel Delta(6) unsaturated homologue. Unsaturated
hopanoids represent an extremely rare feature in soil bacteria and the only known
indication for a catabolism of this pentacyclic carbon skeleton in bacteria.
PMID- 10675601
TI - Selection of Pycnoporus cinnabarinus strains for laccase production.
AB - A comparison of Pycnoporus cinnabarinus strains for laccase production was
carried out. A dikaryotic strain, I-937 strain, producing a high level of laccase
(9500 U l(-1)) was selected. The study of the life cycle in vitro of this
dikaryotic strain led to isolation of monokaryons. Forty-eight monokaryotic
strains were isolated and screened for laccase production. One of these strains,
ss3, produced a higher level of laccase than the parental strain I-937. The
maximum production reached 29000 U l(-1) in medium supplemented with ferulic
acid.
PMID- 10675602
TI - A non-stop antisense reading frame in the grp78 gene of Neurospora crassa is
homologous to the Achlya klebsiana NAD-gdh gene but is not being transcribed.
AB - A long non-stop reading frame exists on the antisense strand of the grp78 gene
(cDNA and genomic DNA) of Neurospora crassa. Computer analysis revealed a strong
similarity of the putative antisense protein to the 10th exon of the NAD
dependent glutamate dehydrogenase gene (NAD-gdh) of Achlya klebsiana, which is
itself located on the complementary strand of a transcribed hsc70 gene homologue.
In Neurospora, no grp78 antisense mRNA was detected by Northern blot and reverse
transcription-coupled polymerase chain reaction analyses, indicating that this
long reading frame is not being transcribed. Hypotheses for the presence of such
unexpressed non-stop reading frames are discussed.
PMID- 10675603
TI - Copper accumulation by sulfate-reducing bacterial biofilms.
AB - Sulfate-reducing bacterial biofilms were grown in continuous culture. When
exposed to medium containing 20 or 200 microM Cu, biofilms accumulated Cu. Energy
dispersive X-ray analysis (EDXA) showed that accumulation of Cu occurred in the
form of sulfides while EDXA mapping of Cu and S in biofilm sections indicated
that they were not uniformly distributed but located in the surface of the
biofilm. While the polymer content of biofilm exposed to 20 microM Cu did not
appear to increase relative to control Cu-free biofilms, biofilms exposed to 200
microM Cu accumulated carbohydrate and smaller amounts of protein throughout the
incubation period. The mechanism of uptake, therefore, appeared to be
precipitation of Cu sulfides at the biofilm surface or in the liquid phase
followed by entrapment of precipitated Cu sulfide by the exopolymer-enhanced
biofilm.
PMID- 10675604
TI - Interleukin-4-deficient BALB/c mice develop an enhanced Th1-like response but
control cardiac inflammation following Borrelia burgdorferi infection.
AB - Interleukin-4 has been reported to critically modulate Borrelia burgdorferi
infection and Lyme arthritis in experimental murine models. To determine the in
vivo role of IL-4 in controlling Lyme carditis, we compared immunological
responses and the severity of cardiac inflammation in wild-type BALB/c (IL-4 +/+)
and IL-4 deficient BALB/c (IL-4 -/-) mice infected with B. burgdorferi by tick
bite. At day 15 and 30 post-infection IL-4 -/- mice produced significantly
greater titers of spirochete-specific IgG2a than the wild-type IL-4 +/+ mice,
which produced significantly more spirochete-specific IgG1. Following in vitro
antigenic stimulation with B. burgdorferi antigen, splenocytes from infected IL-4
-/- and IL-4 +/+ mice displayed similar magnitudes of proliferative responses at
day 15 and 30 post-infection. At day 30 antigen-stimulated splenocytes from
infected IL-4 -/- mice, however, produced significantly more IFN-gamma than those
derived from similarly infected IL-4 +/+ mice, suggesting that Th1-influenced
responses predominated in IL-4 -/- mice. Moreover, inflamed hearts from IL-4 -/-
mice displayed higher levels of IFN-gamma and TNF-alpha transcripts as compared
to IL-4 +/+ mice. At both time points antigen-stimulated splenocytes from IL-4
+/+ and IL-4 -/- mice produced significant amounts of IL-10 but those from IL-4
+/+ mice produced either no or little IL-4. Histopathology demonstrated typical
Lyme carditis in both IL-4 +/+ and IL-4 -/- mice at day 15 and day 30. Although
Borrelia-infected IL-4 -/- mice developed a more severe carditis on day 30, the
carditis resolved by day 50, as it did in IL4 +/+ mice. These results indicate
that although IL-4 may help limit the severity of Lyme carditis, its absence does
not preclude resolution of cardiac lesions.
PMID- 10675605
TI - Regulation of the plasma membrane potential in Pneumocystis carinii.
AB - Many protists use a H(+) gradient across the plasma membrane, the proton motive
force, to drive nutrient uptake. This force is generated in part by the plasma
membrane potential (DeltaPsi). We investigated the regulation of the DeltaPsi in
Pneumocystis carinii using the potentiometric fluorescent dye bisoxonol. The
steady state DeltaPsi in a buffer containing Na(+) and K(+) (standard buffer) was
found to be -78+/-8 mV. In the absence of Na(+) and K(+) (NMG buffer) or Cl(-)
(gluconate buffer), DeltaPsi was not significantly changed suggesting that cation
and anion conductances do not play a significant role in the regulation of
DeltaPsi in P. carinii. The DeltaPsi was also not affected by inhibitors of the
Na(+)/K(+)-ATPase, ouabain (1 mM), and the K(+)/H(+)-ATPase, omeprazole (1 mM).
In contrast, inhibitors of the plasma membrane H(+)-ATPase,
dicyclohexylcarbodiimide (100 microM), N-ethylmaleimide (100 microM) and
diethylstilbestrol (25 microM), significantly depolarized the DeltaPsi to -43+/
7, -56+/-5 and -40+/-12 mV, respectively. The data support that the plasma
membrane H(+)-ATPase plays a significant role in the regulation of DeltaPsi in P.
carinii.
PMID- 10675606
TI - Intact Cryptosporidium parvum oocysts isolated after in vitro excystation are
infectious to neonatal mice.
AB - In vitro excystation is often used as a measure of viability of encysted
protozoan parasites. Parasites that do not excyst in vitro are assumed to be non
viable and non-infectious, whereas those that do excyst are assumed viable. To
test the validity of these assumptions, Cryptosporidium parvum oocysts were
excysted in vitro using two different excystation protocols, and the non-excysted
intact oocysts were isolated using flow cytometry. Non-excysted sorted oocysts
readily infected neonatal CD-1 mice. Increasing the duration of the excystation
assays from 1 h to 3 h resulted in a higher percent of excysted oocysts, but the
remaining non-excysted parasites were still capable of infecting neonatal CD-1
mice. Our results suggest that in vitro excystation is not an accurate measure of
the viability or infectious potential of C. parvum oocysts.
PMID- 10675607
TI - The Drosophila primo locus encodes two low-molecular-weight tyrosine
phosphatases.
AB - The fine modulation of tyrosine phosphorylation by protein tyrosine phosphatases
and protein tyrosine kinases is a key regulatory mechanism for many cell
signaling pathways active during development. In a screen for genes with
interesting expression patterns in the developing Drosophila pupal retina, we
identified a novel pair of protein tyrosine phosphatases that exhibit an
expression pattern suggesting a role in multiple steps of Drosophila
neurogenesis. Together, these phosphatases define the primo locus. Their sequence
is approx. 50% identical to each other and to low-molecular-weight protein
tyrosine phosphatases (LMW-PTPs) identified in other species. Little is
understood of the biological role of LMW-PTPs, and the powerful tools available
in Drosophila should provide important insight into their role in signaling and
development.
PMID- 10675608
TI - Structure and chromosomal localization of the rat salivary Psp and Smgb genes.
AB - SMGB and PSP are among the most abundant products of the immature acinar cells in
developing rat parotid and submandibular glands and are also products of the
sublingual gland serous demilunes. Previous analysis of Smgb and Psp cDNA clones
demonstrated a high degree of sequence similarity between the signal peptide
encoding and 3' untranslated regions of these transcripts, although the secreted
proteins themselves are more divergent. The current study reports the upstream
sequences, genomic organization and localization of the Psp and Smgb genes. Both
structural genes contain nine exons and are present at 3q41-3q42, where they are
arranged in tandem and separated by 21kb. In addition to the previously observed
sequence similarity, Psp and Smgb are highly homologous throughout exon 1 and at
365 of 600bp immediately upstream of the transcription start site. These findings
indicate that the Psp and Smgb genes arose by tandem duplication and divergence.
The similar neonatal submandibular and parotid gland expression patterns observed
for these genes are likely to be due to closely conserved or shared enhancer(s).
PMID- 10675609
TI - Chain reaction cloning: a one-step method for directional ligation of multiple
DNA fragments.
AB - A novel DNA assembly method, chain reaction cloning (CRC), is described. CRC
enables the ordered assembly of multiple DNA fragments in a single step. The
power of the technique was demonstrated by the directed in vitro assembly of a
plasmid comprised of six DNA fragments from a pool of 12 available fragments. The
odds of obtaining the correct plasmid clone in a single step, using conventional
techniques, is less than 1 in 191000000. Using CRC, the desired plasmid was
recovered at a frequency of one in two. Ligation is no longer the rate limiting
step in cloning, and limitless possibilities exist for the reconstruction of
complex genomes.
PMID- 10675610
TI - Cloning of a human gene closely related to the genes coding for the c-myc single
strand binding proteins.
AB - Southwestern screening of human fibroblast cDNAs with an upstream element of the
alpha2(I) collagen promoter (Box 5A) has led to the identification of a novel
gene product (RBMS3). RBMS3 contains two pairs of RNA binding motifs and is very
closely related to the structure of the c-myc gene single-strand binding proteins
(MSSPs). MSSPs are believed to regulate DNA replication, transcription,
apopotosis and cell cycle progression by interacting with the C-MYC protein.
Consonant with this postulate, RBMS3 binds in vitro to the minus strand of Box 5A
and transactivates transcription in the chimeric GAL4 hybrid system. However, the
RBMS3 protein mostly localizes to the cytoplasm of transfected cells, in addition
to binding strongly in vitro to synthetic poly-U and poly-A oligoribonucleotides.
Finally, overexpression in transfected fibroblasts of RBMS3 with and without a
nuclear localization signal has no effect on Box 5A-driven transcription. The
results thus exclude RBMS3 involvement in the transcriptional regulation of
COL1A2 and strongly suggest a cytoplasmic function of this new member of the MSSP
family. As part of the initial characterization of RBMS3 we have also established
that the gene resides on human chromosome 3p23-p24 and is widely expressed in the
embryo and in the adult organism.
PMID- 10675611
TI - Nob1p, a new essential protein, associates with the 26S proteasome of growing
saccharomyces cerevisiae cells.
AB - Nob1p, which interacts with Nin1p/Rpn12, a subunit of the 19S regulatory particle
(RP) of the yeast 26S proteasome, has been identified by two-hybrid screening.
NOB1 was found to be an essential gene, encoding a protein of 459 amino acid
residues. Nob1p was detected in growing cells but not in cells in the stationary
phase. During the transition to the stationary phase, Nob1p was degraded, at
least in part, by the 26S proteasome. Nob1p was found only in proteasomal
fractions in a glycerol gradient centrifugation profile and immuno-coprecipitated
with Rpt1, which is an ATPase component of the yeast proteasomes. These results
suggest that association of Nob1p with the proteasomes is essential for the
function of the proteasomes in growing cells.
PMID- 10675612
TI - Crossover hot-spot instigator (Chi) sequences in Escherichia coli occupy distinct
recombination/transcription islands.
AB - Crossover hot-spot instigator (Chi) sequences (5'-GCTGGTGG-3') are orientation
dependent, strand-specific sequences implicated in RecA-mediated DNA
recombination. In Escherichia coli and Haemophilus influenzae Chi and Chi-like
sequences preferentially locate to approx. 1kb recombination 'islands' in the
mRNA-synonymous strands of open reading frames (ORFs). Since mRNA-synonymous
strands follow Szybalski's transcription direction rule in being G-rich, and the
average ORF is about 1kb, then, on this basis alone, Chi sequences are seen to
reside in 1kb G-rich 'islands'. However, RecA preferentially binds GT-rich
sequences, suggesting that genomic context might potentiate Chi action.
Consistent with this, we report for E. coli that 1kb sequence windows with Chi
near their centres are a distinct subset of total 1kb windows, the mRNA
synonymous strands being preferentially enriched in both G and T. Chi function
might be particularly important for bacteria that survive high temperature and
radiation. These often exist in habitats where recombination with E. coli DNA
would be unlikely, so canonical Chi sequences might not confer a selective
disadvantage in this respect. In general, Chi sequences are not more frequent in
thermophilic bacteria and Deinococcus radiodurans, than in E. coli and other
mesophilic bacteria. Only two of five thermophilic bacteria examined showed
preferential location of Chi sequences to mRNA-synonymous strands. In the
thermophile Methanococcus jannaschii, windows containing the canonical Chi
sequence do not form a distinct subset. We suggest that in thermophilic bacteria
and D. radiodurans the Chi function may be achieved by sequences that differ from
the canonical Chi sequence, or that the number of these sequences is sufficient,
or that the Chi function is unnecessary.
PMID- 10675613
TI - Sequence, genomic organization and functional expression of the murine tRNA
specific adenosine deaminase ADAT1.
AB - We have recently identified the first mammalian tRNA-specific adenosine deaminase
human ADAT1, a member of the ADAR family of RNA editing enzymes. This protein is
responsible for the first step of the unique A(37) to m(1)I(37) modification in
eukaryotic tRNA(Ala). Here, we present the genomic structure of murine ADAT1 and
the functional expression of mADAT1 cDNA. In mouse, as well as in human, ADAT1 is
expressed from a single copy gene. The coding region of the mADAT1 gene is spread
over nine exons, covering approximately 30kb of genomic DNA and encodes a protein
of 499 amino acids. Overall, mADAT1 shares 81% nucleotide homology and 87.5%
protein homology with the human ortholog. The recombinant mouse protein is active
specifically and with a high efficiency on human tRNA(Ala) in vitro. Its genomic
organization is compared to the structures of the sequence-related, pre-mRNA
specific adenosine deaminases ADAR1 and ADAR2.
PMID- 10675614
TI - Conservation of sequence and function of the pag-3 genes from C. elegans and C.
briggsae.
AB - The Caenorhabditis briggsae homologue of the Caenorhabditis elegans pag-3 gene
was cloned and sequenced. When transformed into a C. elegans pag-3 mutant, the C.
briggsae pag-3 gene rescued the pag-3 reverse kinker and lethargic phenotypes.
The C. elegans pag-3 gene fused to lacZ was expressed in the same pattern in C.
elegans and C. briggsae. Unlike many gene homologues compared between C. elegans
and C. briggsae, extensive sequence conservation was found in the non-coding
regions upstream of the pag-3 exons, in several of the introns and in the
downstream non-coding region. Furthermore, the splice acceptor and splice donor
sites were conserved, and the size of the introns and exons was surprisingly
similar. The predicted protein sequence of C. briggsae PAG-3 was 85% identical to
the protein sequence of C. elegans PAG-3. Because so much of the non-coding
region of pag-3 was conserved, the control of pag-3 may be quite complex,
involving the binding of many trans-acting factors. These results suggest the
evolutionary conservation of the pag-3 gene sequence, its expression and
function.
PMID- 10675615
TI - Genomic organization and transcriptional analysis of the human genes coding for
caveolin-1 and caveolin-2.
AB - Caveolin-1 and caveolin-2 are related proteins involved in the biogenesis of
caveolae. The corresponding genes in humans (CAV and CAV2, respectively), have
been mapped to a common locus in chromosome 7q31.1, and are possible candidates
for the tumor suppressor gene postulated in this region. Here, we show that CAV
and CAV2 are independent transcriptional units lying in the same orientation,
with CAV2 centromeric and about 17kb upstream to CAV. The two genes have similar
tissue expression patterns. Alternative termination/polyadenylation generates two
CAV2 mRNAs. Multiple transcriptional start sites spanning 35bp upstream from the
CAV2 ATG are detected by 5' RACE, consistent with a TATA-less promoter predicted
by sequence analysis. The CAV2 promoter region contains two SRE-like boxes
resembling those described in the CAV promoter and proposed to link transcription
to intracellular cholesterol levels. However, exogenous sterols had only minor
effects on CAV and CAV2 RNA levels in HeLa cells, suggesting that SREBPs are not
sufficient to regulate caveolin transcription.
PMID- 10675616
TI - An isozyme of the NADP-malic enzyme of a CAM plant, Aloe arborescens, with
variation on conservative amino acid residues.
AB - In Aloe arborescens, an obligate CAM plant, Western analysis detected three major
isoforms of NADP-malic enzyme (NADP-ME), 72kDa with a pI of 6.0, 65kDa with a pI
of 5.6 and 65kDa with a pI of 5.5. Among them, the 65kDa protein with a pI of 5.5
was leaf-specific, and the 65kDa protein with a pI of 5.6 was found only in
roots, whereas the 72kDa protein was uniformly detected in both organs. Activity
staining indicated enzyme activity of both 65kDa NADP-MEs but little activity of
the 72kDa protein. A cDNA clone encoding a leaf-abundant NADP-ME, AME1, was
isolated. Deduced amino acid sequence of AME1 showed a high degree of homology to
known NADP-MEs, but it was also found that AME1 contained substitutions on five
conservative amino acid residues, some of which have been predicted to be
important for their enzyme activity. Transgenic rice carrying the aloe AME1 gene
efficiently produced an additional 65kDa protein with a pI of 5.5 as an active
NADP-ME. These results indicate that AME1 corresponds to the leaf-specific 65kDa
NADP-ME, which may be involved in CAM photosynthesis. It was also shown that
substitutions of these conservative amino acid residues identified in AME1 still
allowed it to give enzyme activity.
PMID- 10675617
TI - Structural characterisation of the mouse nuclear oxysterol receptor genes
LXRalpha and LXRbeta.
AB - Oxysterols are important regulatory molecules of diverse biological processes
such as cholesterol homeostasis, bile acid synthesis and apoptosis. Recent
findings led to the suggestion that some of these functions are mediated by the
nuclear receptors LXRalpha and LXRbeta owing to their potential to bind a group
of naturally occurring oxysterols as their ligands. In this report, we compare
the genomic structure and the promoter regions of the two mouse LXR genes. In
addition, we show evidence for the presence of a processed, but truncated LXRbeta
pseudogene in the mouse genome. RACE-PCR on mouse liver cDNA demonstrates the
presence of more than one defined transcription initiation site for both genes.
The LXRalpha and LXRbeta promoter regions are GC-rich and contain a number of
putative Sp1 binding sites but lack obvious TATA and CAAT boxes. A database
search revealed several sequence motifs in the LXR promoter regions that resemble
known transcription factor binding sites. Most striking is the identification of
one potential NFkappaB and seven potential Ets-protein binding sites in the
LXRbeta promoter, suggesting an important role for this receptor in the
haematopoietic/immune system.
PMID- 10675618
TI - Alfalfa (Medicago sativa) carbamoylphosphate synthetase gene structure records
the deep lineage of plants.
AB - Given the central role of carbamoylphosphate synthetases in pyrimidine and
arginine metabolism in all living organisms, the absence of fundamental
information regarding plant CPSase genes is a striking omission [Lawson et al.,
Mol. Biol. Evol. 13 (1996) 970-977; van den Hoff et al., J. Mol. Evol. 41 (1995)
813-832]. Whereas CPSase gene architecture and aa sequence have proven to be
useful characters in establishing ancient and modern genetic affinities,
phylogenetic analysis cannot be completed without the inclusion of plant CPSases.
We describe the first isolation by molecular cloning of a plant CPSase gene
(CPAII) derived from alfalfa (Medicago sativa). DNA sequence analysis reveals a
proteobacterial architecture, namely closely linked carA and carB coding domains
separated by a short intergenic region, and transcribed as a polycistronic mRNA.
CPAII encodes the amino acid residues that typify a CPSase type II enzyme. In
addition, an ancient internal duplication has been retained in the plant carB
sequence. Partial nucleotide sequencing of additional clones reveals that the
alfalfa genome contains multiple CPSase II gene copies which may be tissue
specific in their expression. It appears that with respect to CPSase genes, CPAII
resembles the carAB gene of bacteria, and may have preserved much of this ancient
gene structure in the alfalfa genome.
PMID- 10675619
TI - Isolation and genomic analysis of the human surf-6 gene: a member of the Surfeit
locus.
AB - The human Surfeit locus contains at least six tightly clustered genes (Surf-1 to
Surf-6) of which five (Surf-1 to Surf-5) have been characterised and found not to
share any sequence homology. The organisation and juxtaposition of the Surfeit
genes are conserved between human and mouse. The Surf-6 gene that encodes a novel
nucleolar-matrix protein with nucleic-acid binding properties has been
characterised in mouse. In this work, we have isolated and analysed the human
Surf-6 homologue and determined its genomic organisation in the Surfeit locus.
The human Surf-6 gene has five exons spread over a distance of 4.3kb and has
features of a housekeeping gene being ubiquitously expressed, having its 5' end
located within a CpG rich island and lacking a canonical TATA box. The intragenic
region between the 3' end of the Surf-5 gene and the 5' end of the Surf-6 gene is
3.2kb and contains a pseudogene of the ribosomal protein gene rpL21. The putative
human Surf-6 protein is 361 amino acids long and includes motifs found in both
the mouse and fish Surf-6 homologues, which may underlie the functions of Surf-6.
Three amino acid polymorphisms have been detected at codons 163, 175 and 311 by
SSCP analysis.
PMID- 10675620
TI - Role of the ruvB gene in homologous and homeologous recombination in Rhizobium
etli.
AB - The Rhizobium etli ruvA and ruvB genes were cloned through a PCR-based approach,
using degenerate primers matching conserved sectors in the amino acid sequences
of RuvB from eight bacterial species. Comparative analysis of the predicted
polypeptides for RuvA and RuvB of R. etli showed highly conserved blocks with the
corresponding homologs in other bacteria; RuvB depicts characteristic motifs for
DNA helicases (ATP-binding and DEXH-box motifs). An R. etli ruvB::loxP Sp mutant
was constructed by interposon mutagenesis. This mutant was highly sensitive to
DNA-damaging agents, such as methyl methanesulfonate and nitrofurantoin, implying
a deficiency in DNA repair. Homologous and homeologous conjugational
recombination was reduced almost tenfold in the ruvB::loxP Sp mutant; a
recombination defect was also observed in assays employing recombination between
small plasmids, albeit at a smaller magnitude. Although the ruvA and ruvB genes
are contiguous in R. etli, complementation studies suggest that they are
expressed independently.
PMID- 10675621
TI - An effective family shuffling method using single-stranded DNA.
AB - Family shuffling, which is one of the most powerful techniques for in vitro
protein evolution, always involves the problem of reassembling the gene fragments
into parental gene sequences, because such a process prevents the formation of
chimeric sequences. In order to improve the efficiency of hybrid formation in
family shuffling, single-stranded DNAs (ssDNAs) were used as templates. The
ssDNAs of two catechol 2,3-dioxygenase genes, nahH and xylE, were prepared, the
xylE strand being complementary to the nahH strand. When these ssDNAs were
digested by DNase I and reassembled, chimeric genes were obtained at a rate of
14%, which was much higher than the rate of less than 1% obtained by shuffling
with double-stranded DNAs. Chimeric catechol 2,3-dioxygenases that were more
thermally stable than the parental enzymes, XylE and NahH, were obtained by this
ssDNA-based DNA shuffling.
PMID- 10675622
TI - A comparison of the pectate lyase genes, pel-1 and pel-2, of Colletotrichum
gloeosporioides f.sp. malvae and the relationship between their expression in
culture and during necrotrophic infection.
AB - Extracellular pectic lyase and polygalacturonase activities of Colletotrichum
gloeosporioides f.sp. malvae were detected in broths containing mallow cell wall
extract, pectin or glucose as the carbon source. The initial pH of the broth as
well as the carbon source had major influences on pectinase enzyme activities. In
the host, only pectic lyase activity was detected, which began at the end of the
biotrophic phase and increased in the necrotrophic phase of infection. Two full
length pectate lyase cDNAs, pel-1 and pel-2, were cloned from the fungus. Both
genes showed similar patterns of expression when the fungus was grown in mallow
cell-wall extract and pectin medium, and the only major difference in expression
in culture was that only pel-2 was expressed in glucose broth. Expression of pel
1 and pel-2 was also affected by the initial pH of the medium. Expression of pel
2, but not pel-1, was detected during infection of the host, round-leaved mallow,
Malva pusilla. Transcripts of pel-2 were first detectable during the necrotrophic
phase of infection approx. 24h after the first detection of pectic lyase enzyme
activity. A comparison of expression of pel-1 and pel-2 in culture and in planta
with other pectinase genes of C. gloeosporioides f.sp. malvae, as well as with
other plant pathogenic fungi, indicates that expression during necrotrophic
infection correlates with the ability to be expressed in media containing
glucose.
PMID- 10675623
TI - Molecular cloning, characterization and expression of a novel retinal clusterin
like protein cDNA.
AB - A novel gene expressed predominantly in retina, but detected at a conspicuously
lower level in retina of canine progressive rod cone degeneration (prcd), has
been identified by suppression subtractive hybridization and retinal cDNA library
screening. The characterized region of cDNA of the novel gene includes 1017
nucleotides of coding sequence predicted to encode a protein of 338 amino acids
(M(r) 39389), 791 nucleotides of 5'-untranslated region (UTR), and 300
nucleotides of 3'-UTR including the poly(A)(+) tail. Multiple transcripts were
detected in retina by Northern blot analysis, and a lower level of expression was
observed in brain and liver by RT-PCR. The transcript appears to be
developmentally regulated with a burst in gene expression at a time period (34
postnatal days) that coincides with the photoreceptor differentiation phase of
retinal development. The deduced amino acid sequence from the cDNA of the novel
gene has 24% identity and 48% similarity with the multifunctional glycoprotein
clusterin. Hence, the putative gene product from the novel transcript has been
named clusterin-like protein 1 (CLUL1). The human homologue of CLUL1 cDNA has 84
and 70% identity at the level of nucleotides and amino acids, respectively, with
the characterized canine cDNA. The presence of a stretch of 128 amino acids in
the putative human CLUL1, not detected in canine CLUL1, suggests alternate
splicing events. An STS database search revealed that the human homologue of
CLUL1 maps to chromosome 18p, a location not yet reported to harbor an RP locus.
Tissue-specific expression of CLUL1 in retina, and its lower abundance in
different forms of PRA suggest that this novel gene may represent an as-yet
unidentified locus for a retinal disorder.
PMID- 10675624
TI - Exon-intron organization of the human gp130 gene.
AB - The exon-intron organization and sequences of the exon-intron boundaries of the
human gp130 transmembrane receptor gene have been determined using genomic DNAs
as samples. The gp130 gene comprises 17 exons and 16 introns. The positions of
the exon-intron boundaries show good correlation to the functional/homology
regions of gp130. Exons 3-17 code for the gp130 protein, and each subdomain of
the receptor is encoded by a set of exons. The coding potential of exons and the
intron phasing of the human gp130 gene conform to the patterns observed
previously for other cytokine receptor genes. This supports the notions that the
gp130 gene evolved from the same ancestral gene that gave rise to other members
of the cytokine receptor family.
PMID- 10675625
TI - cDNA cloning, characterization, expression and recombinant protein production of
leukemia inhibitory factor (LIF) from the marsupial, the brushtail possum
(Trichosurus vulpecula).
AB - A reverse transcription technique using RNA templates combined with polymerase
chain reaction (RT-PCR) was used to clone the cDNA fragment encoding the amino
acid sequence of mature LIF protein of the marsupial, the brushtail possum,
Trichosurus vulpecula. A PCR product with expected size, of 546bp, and termed
tvLIF, was obtained using cDNA reverse-transcribed from total RNA isolated from
possum uterus. A genomic DNA fragment (about 650bp) between the specified primers
was also amplified, indicating the similarity in structure and organization of
this gene and LIF genes from studied eutherian species, although the full-length
of its cDNA and genomic DNA needs to be further clarified. The deduced amino acid
sequence of tvLIF shows a high level of sequence identity and similar molecular
characteristics to eutherian LIF, which suggests similar biological actions of
this molecule in this marsupial. Because the expression of LIF gene in other
mammalian species has been found to be at very low levels and its transcripts
cannot be detected by Northern hybridization analysis, the expression pattern of
tvLIF in adult tissues and reproductive tracts during early development was
investigated using the RT-PCR technique. Resultant products of the RT-PCR were
further analyzed by Southern hybridization using tvLIF as a probe. tvLIF
transcripts were detected in most of the adult tissues and in the reproductive
tracts of pregnant females. These results lend support to the idea that LIF
contributes to the maintenance of pregnancy in this marsupial.
PMID- 10675626
TI - Characterization of a Rab11 homologue in Trypanosoma cruzi.
AB - Vesicle trafficking between organelles occurs through fusion of donor and
specific acceptor membranes. This process is highly regulated and ensures proper
direction in sorting and packaging of a number of molecules in eukaryotic cells.
Monomeric GTPases of the Rab family play a pivotal role in the control of
membrane fusion and vesicle traffic. In this paper, we characterize a Trypanosoma
cruzi Rab 11 homologue (TcRab11) that shares at, the amino acid level, 40%
similarity with human rab11, Arabdopsis thaliana rab11 and yeast rab11 homologue
genes. Western blot analysis, using a polyclonal rabbit antiserum raised against
a synthetic peptide derived from the COOH-terminus of predicted the TcRab11
protein, reacted to a 26kDa protein. In immunofluorescence assays, TcRab 11, was
shown to be expressed in epimastigote and amastigote forms, but it was absent in
trypomastigotes. Interestingly, the TcRab11 product seems to be located at the
reservosome complex, a site of active endocytosis and vesicle fusion present only
in the epimastigote stage. Therefore, TcRab11 may represent the first molecular
marker of this peculiar organelle.
PMID- 10675627
TI - Combinatorial gene expression using multiple episomal vectors.
AB - Episomal vectors offer a powerful alternative to integrative recombination for
transgene expression in mammalian cells. In this study, various combinations of G
protein-coupled receptors (GPCRs) and the G protein subunit G(i2)alpha, were
stably expressed from separate episomal vectors in 293-EBNA (293E) cells. Each
episome did not adversely affect the others, as gauged by episomal copy number,
steady-state mRNA levels and the presence of functional receptors and G protein.
Cell lines expressing genes from multiple autonomously replicating vectors were
stable just two weeks after transfection, and remained stable in continuous
culture for at least 5months. Co-expression of supplementary G(i2)alpha with
receptor amplifies the magnitude of signal transduction thereby permitting the
development of more sensitive high throughput functional assays. Given these
results, combinatorial transfection is the strategy of choice for generating
stable cell lines expressing multiple genes for the study of signal-transduction
pathways or the evaluation of receptor ligands.
PMID- 10675628
TI - RLR1 (THO2), required for expressing lacZ fusions in yeast, is conserved from
yeast to humans and is a suppressor of SIN4.
AB - We isolated a mutation (rlr1-1; required for lacZ RNA) in the Saccharomyces
cerevisiae (Sc) RLR1 gene as a suppressor of sin4, a component of the Mediator
subcomplex of the RNA polymerase II holoenzyme and a determinant of chromatin
structure. RLR1 encodes a deduced protein found also in fission yeast, nematode
worms, and humans. The presence of these orthologs suggests that Rlr1 family
members comprise a class of putative KEKE motif-containing proteins,
characteristic of certain chaperones as well as regulators and subunits of the
mammalian 20S proteasome. A role for RLR1 (THO2) in transcription appears to
occur at a step subsequent to transcription initiation (see also Piruat, J.I. and
Aguilera, A., 1998. EMBO J. 17, 4859-4872); Sc genes fused to the reporter gene
lacZ were expressed at a very low level, while the corresponding native
chromosomal genes were expressed at approximately normal levels in rlr1 mutants.
Our studies show that rlr1 mutations cause a wide range of growth defects in
addition to their novel affect on lacZ.
PMID- 10675629
TI - An ascidian glycine-rich RNA binding protein is not induced by temperature stress
but is expressed under a genetic program during embryogenesis.
AB - We have cloned a putative ascidian glycine-rich RNA binding protein gene, CiGRP1.
Its maternal transcript and protein are stored in the unfertilized egg. They are
gradually decreased during the first few rounds of cleavage. The CiGRP1 zygotic
transcript and protein start to accumulate at the gastrula stage. The CiGRP1
transcript is expressed in the brain precursor and mesenchyme precursor cells of
the gastrula and the neurula stage, and the brain and mesenchyme cells of the
tailbud stage embryo. The CiGRP1 protein is found in all nuclei and in the
cytoplasm of brain and mesenchyme cells. Although many glycine-rich RNA binding
protein homologs of plants and vertebrates are cold-inducible, CiGRP1 cannot be
induced by cold shock or heat shock at the transcriptional and translational
levels during embryogenesis. The temporal expression pattern and the tissue
restricted expression pattern of CiGRP1 suggest that it has important roles in
the very early stage of development and in the brain and the mesenchyme tissue
specification.
PMID- 10675630
TI - Endolymphatic hydrops induced by chronic administration of vasopressin.
AB - Recently, many lines of evidence have supported the possibilities that
vasopressin (VP) is closely linked to the formation of endolymphatic hydrops in
Meniere's disease. In the present study, it was examined whether or not the
chronic administration of VP might induce endolymphatic hydrops. For this
purpose, histological studies and VP radioimmunoassay were independently
performed in 20 and 40 guinea pigs, respectively. The degree of hydrops was
quantitatively assessed by the increase ratio (IR) of the scala media area in the
mid-modiolar sections of the cochlea. The IR was defined by the following
equation: 100x(A-B)/B (A: the cross-sectional area of the bulging scala media; B:
the no-bulging scala media, enclosed by an idealized straight Reissner's
membrane). VP was administered at the rates of 200 microU/kg/min, 400
microU/kg/min and 1000 microU/kg/min for 1 week via the osmotic mini-pump. The IR
of the total of the apical, second, third and basal turns (means+/-S.D.s) were
4.4+/-0.7, 10.4+/-1.8, 17.4+/-7.9 (n=10 ears, each) in respective doses of VP.
Comparing with that of the control animals (5.2+/-1.7, n=10 ears), the area
increased significantly in the VP dosage of 400 and 1000 microU/kg/min
(Bonferroni's method, P<0.05). Plasma VP concentrations produced by the VP
administration in these dosages were 2.2+/-0.4, 3.5+/-0.8 and 14.0+/-3.9 (n=10,
each) pg/ml. Although 3.5 pg/ml is the upper limit of plasma VP concentration in
normal human subjects, 14.0 pg/ml was almost the same concentration as those
observed in the acute phase of Meniere's disease (Takeda et al., 1995).
Therefore, the formation of endolymphatic hydrops in cases of Meniere's disease
might be caused by high concentrations of plasma VP.
PMID- 10675631
TI - Modulation of spontaneous activity by acetylcholine receptors in the rat dorsal
cochlear nucleus in vivo.
AB - In vitro studies have implicated muscarinic acetylcholine receptors (mAChRs) in
the modulation of spontaneous activity (SA) of neurons in the rat dorsal cochlear
nucleus (DCN) (Chen et al., 1994,1998). Early studies suggest that cholinergic
pathways also modulate SA in vivo, but these effects have not been investigated
pharmacologically. The purpose of the present study was to determine whether
multiunit SA can be modulated in vivo by application of cholinergic agents to the
surface of the DCN. Sprague Dawley rats were used in the current experiment. The
influence of cholinergic activation on SA was tested by applying carbachol (5-500
microM) to the DCN surface while recording multiunit SA at a depth of 250 microm.
Out of a total of 32 sites tested, all but 2 (94%) showed well-defined responses
to carbachol, characterized by suppression, activation or a combination of both
(two-component responses). The most common responses were pure suppression and
suppression accompanied by transient activation. Both the proportion of sites
showing suppressive responses and the magnitude of suppression averaged across
sites increased with dose. Although the proportion of sites showing pure
activation in response to carbachol decreased with dose, there was no clear trend
in the magnitude of activation with dose. The suppressive responses to high doses
of carbachol were blocked by pre-application of atropine. These results extend
previous work by suggesting that muscarinic receptors play an important role in
the modulation of SA in vivo.
PMID- 10675632
TI - Neonatal sensorineural hearing loss affects neurone size in cat auditory
midbrain.
AB - We examined the effect of a neonatal sensorineural hearing loss on the soma area
of neurones in the central nucleus of the inferior colliculus (ICC) in adult cats
to evaluate the role of auditory experience on neuronal atrophy within the
auditory midbrain. Three groups of animals were used: bilaterally deafened,
unilaterally deafened and normal hearing controls. Soma area measurements were
made from the laminated central and medial divisions of the ICC of eight deafened
and two normal hearing cats. A small but significant reduction in soma area was
evident for bilaterally deafened animals compared with normal hearing controls
(P<0.05, Dunnett's test). In contrast, there was no significant difference in
mean soma area between normal hearing and unilaterally deafened animals (P0.05)
irrespective of whether the ICC examined was ipsi- or contralateral to the
deafened ear. These results demonstrate that the reduction in soma area of
auditory brainstem neurones reported following a sensorineural hearing loss is
also evident at the level of the auditory midbrain.
PMID- 10675633
TI - Calcium binding proteins and the AMPA glutamate receptor subunits in gerbil
cochlear nucleus.
AB - The alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) glutamate
receptors mediate fast excitatory synaptic transmission in the central nervous
system. The GluR2 subunit confers calcium impermeability to AMPA receptors.
Various calcium binding proteins play a role in calcium regulation within the
neurons. This study sought to identify possible relationships between calcium
binding proteins and glutamate receptor subunits, especially GluR2, in gerbil
cochlear nucleus neurons. Our immunohistochemical observations reveal no
particular correlation between GluR2 and calbindin; all the cell types show
labeling for all the antibodies studied except calretinin. There was coincidence
of strong GluR4 and strong parvalbumin staining in octopus cells, although
calbindin was also present in these cells. This study suggests a possible
relationship between parvalbumin and predominantly GluR4 containing receptors,
even when calbindin is present. The absence of a strong inverse correlation
between the presence of ionotropic AMPA receptor subunit GluR2 and calbindin
suggests a more significant role of non-AMPA ionotropic glutamate receptors or
other voltage-gated channels in the regulation of calcium in the neurons of
cochlear nucleus. Alternatively, more detailed analysis of receptor composition
at particular synapses and the subcellular localization of specific calcium
binding proteins may be required.
PMID- 10675634
TI - Cisplatin-induced hearing loss: influence of the mode of drug administration in
the guinea pig.
AB - Cisplatin (8 mg/kg) was given intravenously to guinea pigs either as a 15 s bolus
injection (25 animals) or as a 1 h infusion (28 animals). To determine the
influence of the mode of cisplatin administration and pharmacokinetics on the
ototoxic side-effect, the concentrations of cisplatin and the biotransformation
product monoaquated cisplatin were determined in blood ultrafiltrate using liquid
chromatography with post-column derivatization. Ototoxic effect was evaluated as
difference in pre- and 96 h post-exposure auditory brainstem response (ABR)
threshold. The cisplatin peak concentration was considerably higher, 19.2+/-2.4
microg/ml, in the bolus injection group than in the infusion group, 6.7+/-0.5
microg/ml (mean+/-S.E.M.). The area under the blood ultrafiltrate concentration
time curve (AUC) for cisplatin was slightly greater in the infusion group, 442+/
26 microg/ml/min, than in the bolus injection group, 340+/-5 microg/ml/min. For
monoaqua cisplatin, the AUC was not different between the groups (bolus
injection: 30.8+/-1. 5 microg/ml/min, infusion: 34.1+/-3.3 microg/ml/min). A
significant ototoxic effect was observed in both groups at 20 and 12.5 kHz, but
there was no difference between the groups in the extent of threshold shift. The
interindividual variability in susceptibility to ABR threshold shift was far
greater than the variability in pharmacokinetics, suggesting that other factors
are more important in determining the degree of hearing loss.
PMID- 10675635
TI - Electrical stimulation of the auditory nerve. III. Response initiation sites and
temporal fine structure.
AB - Latency, temporal dispersion and input-output characteristics of auditory nerve
fiber responses to electrical pulse trains in normal and chronically deafened cat
ears were classified and tentatively associated with sites where activity is
initiated. Spikes occurred in one or more of four discrete time ranges whose
endpoints overlapped partially. A responses had latencies <0.44 ms, exhibited
asymptotic temporal dispersion of 8-12 micros and possessed an average dynamic
range of 1.2 dB for 200 pulses/s (pps) pulse trains. They likely originated from
central processes of spiral ganglion cells. B(1) and B(2) responses (0.45-0.9 ms,
25-40 micros, 1.9 dB) likely stemmed from activity at myelinated and unmyelinated
peripheral processes, respectively. C100 micros) likely originated from direct
stimulation of inner hair cells, and D8 dB) arose from propagating traveling
waves possibly caused by electrically induced motion of outer hair cells. C and D
responses were recorded only in acoustically responsive ears. Mean latencies of
spikes in all time ranges usually decreased with intensity, and activity at two
or even three discrete latencies was often observed in the same spike train.
Latency shifts from one discrete time range to another often occurred as
intensity increased. Some shifts could be attributed to responses to the opposite
polarity phase of the biphasic pulse. In these cases, temporal dispersion and
dynamic range were approximately equal for activity at each latency. A second
type of latency shift was also often observed, in which responses at each latency
exhibited dissimilar temporal dispersion and dynamic range. This behavior was
attributed to a centralward shift in the spike initiation site and it occurred
for monophasic as well as biphasic signals. Several fibers exhibited dual latency
activity with a 40-90 micros time difference between response peaks. This may
have stemmed from spike initiation at nodes on either side of the cell body.
Increasing the stimulus pulse rate to 800-1000 pps produced small increases in
temporal dispersion and proportionate increases in asymptotic discharge rate and
dynamic range, but thresholds did not improve and slopes of rate-intensity
functions (in spikes/s/dB) did not change. Responses to high-rate stimuli also
exhibited discrete latency increases when discharge rates exceeded 300-400
spikes/s. Spike by spike latencies in these cases depended strongly on the
discharge history. Implications for high-rate speech processing strategies are
discussed.
PMID- 10675636
TI - Differential expression of voltage-gated potassium channel genes in auditory
nuclei of the mouse brainstem.
AB - Voltage-gated potassium (Kv) channels may play an important role in the encoding
of auditory information. Towards understanding the roles of Shaker and Shaw-like
channels in this process, we examine here the expression of Kv1.1, Kv1.2, Kv3.1,
and Kv3.3 in the central auditory nuclei of the mouse using quantitative in situ
hybridization techniques. We establish rank order for each channel's expression
in each region, finding that the medial nucleus of the trapezoid body shows the
highest signal for each of the four channel genes. In other auditory nuclei
differential expression is found among and between members of both Shaker and
Shaw subfamilies. Of particular interest is the stark contrast between high level
expression of Kv1.1 and very low level expression of Kv3.1 in the octopus cell
area of the cochlear nucleus and in the lateral superior olivary nucleus. These
unique expression patterns suggest that Kv channel gene expression is regulated
to allow brainstem auditory neurons to transmit temporally patterned signals with
high fidelity. In instances where specific cell types can be tentatively
identified, we discuss the possible contribution made by these channel genes to
the physiological properties of those neurons.
PMID- 10675637
TI - Lipopolysaccharide-induced expression of inducible nitric oxide synthase in the
guinea pig organ of Corti.
AB - The purpose of the investigation was to ascertain whether inoculation of
bacterial lipopolysaccharide (LPS) into the cochlea of the guinea pig could
elicit formation of inducible nitric oxide synthase (iNOS). Immunohistochemical
study revealed that immunoreactivity to iNOS was seen below outer hair cells
representing nerve fibers and synaptic nerve endings. iNOS-staining could also be
observed in phalangeal dendrites of Deiter's cells pointing to the cuticular
membrane, Hensen's cells and on stria vascularis 48 h after inoculation with LPS.
Immunohistochemical investigation with a specific anti-nitrotyrosine antibody
also revealed intense immunoreactivity identical to that of iNOS, suggesting
formation of peroxynitrite in the organ of Corti by the reaction of NO with O(2)(
). On the basis of these findings, it can be concluded that NO together with
O(2)(-), which form the more reactive peroxynitrite, are the most important
pathogenic agents in LPS-induced damage of cochlea in the guinea pig.
PMID- 10675638
TI - Evidence for multiple DPOAE components based upon group delay of the 2f(1)-f(2)
distortion in the gerbil.
AB - The cochlear delay of the 2f(1)-f(2) distortion product otoacoustic emission
(DPOAE) was measured using the phase gradient method. With a constant f(2) and
swept f(1), the resulting phase change of 2f(1)-f(2) was used to calculate the
group delay for f(2) frequencies from 1 to 60 kHz. For f(2) frequencies between 2
and 60 kHz, the group delays were between 2.2 and 0.11 ms and continuously
decreased for increasing f(2) and for increasing primary stimulus levels. For
f(2) frequencies below 2 kHz, the group delay decreased to around 1 ms and was
largely independent of stimulus level. The ratio curves resulting from the f(1)
sweeps for high frequencies (f(2)16 kHz) displayed the typical mammalian shape
with a peak in the level of 2f(1)-f(2) for a larger primary frequency separation
(f(2)/f(1)1.15) and decreasing 2f(1)-f(2) level for smaller primary separation.
In addition to this typical level maximum, for f(2) frequencies from about 1.8 to
16 kHz, the ratio curves displayed a second component in the form of an increase
in the level of 2f(1)-f(2) for small primary separation at higher primary levels
(level of f(2)30 dB SPL). For f(2) frequencies below 1.8 kHz, only the second
component and no typical ratio peak as for higher f(2) could be observed and the
associated group delay was always close to 0.8 ms. Several possible causes for
this behavior are discussed, including different modes of DPOAE generation and
modulation as well as changes in the nature of mechanical processing from base to
apex in the gerbil cochlea. To evaluate the relative sensitivity of non-linear
cochlear mechanics, an iso-distortion threshold curve was constructed from
acoustical growth functions of the 2f(1)-f(2) DPOAE at optimum primary
separation, by plotting the level of f(2) sufficient to evoke a distortion of -10
dB SPL as a function of f(2)2.5 kHz but failed to reflect the sensitivity for
lower frequencies. This may be a consequence of more linear frequency processing
in the apex.
PMID- 10675639
TI - Activation of medial olivocochlear efferent system in humans: influence of
stimulus bandwidth.
AB - The activity of the medial olivocochlear bundle (MOCB) can be studied in humans
through variations in the level of evoked otoacoustic emissions (EOAEs) elicited
by contralateral acoustic stimuli (CAS). The present study sought to investigate
how the activity of the MOC system at a given frequency, as measured through the
contralateral suppression of tone-pip EOAEs, depends on the bandwidth of the
contralateral stimulus. EOAEs were recorded in 155 normal-hearing subjects,
successively with and without contralateral stimuli whose bandwidth, center
frequency and level were systematically varied. We showed a clear dependence of
contralateral EOAE suppression on bandwidth demonstrating increased suppression
with increased bandwidth over about two octaves around the center frequency of
the noise. This effect was obtained irrespective of whether contralateral noise
energy was kept constant independently of bandwidth or not, which indicates a
role of bandwidth per se in contralateral EOAE suppression. Results are
interpreted in terms of a simple model of MOCB activation mechanisms including
peripheral bandpass filtering, within-channel compression and across-channel
spatial summation by the afferent paths. Complementary experiments suggested a
greater effectiveness of increases in bandwidth on the upper than on the lower
side and of frequency components akin to or remote from the test frequency than
of intermediate bands. Finally, these results were complemented by detailed
spectrum analyses of the EOAE level variations induced by the different noises,
which revealed that whilst noise components close to or remote from the center
frequency generally attenuated EOAE level, intermediate components could in some
cases lead to a relative increase in EOAE level. These results can further be
explained by assuming different positive and negative weights on the inputs to
the spatial summation process depending on their position relative to the center
frequency.
PMID- 10675640
TI - Glycine induced calcium concentration changes in vestibular type I sensory cells.
AB - Glutamate is the neurotransmitter of the synapse between vestibular type I hair
cells and the afferent nerve calyx. This calyx may also be involved in local
feedback, which may modify sensory cell activity via N-methyl-D-aspartate (NMDA)
receptors. Glycine is the co-agonist of glutamate in NMDA receptor activation.
Both agents have been detected by immunocytochemistry in the nerve calyx.
Glutamate and NMDA stimulations cause changes in the intracellular calcium
concentration ([Ca(2+)](i)) of isolated type I sensory cells. We investigated the
effect of glycine stimulation on [Ca(2+)](i) in guinea pig type I sensory cells
by spectrofluorimetry with fura-2. Glycine application to isolated type I sensory
cells induced a rapid and transient increase in [Ca(2+)](i). The fluorescence
ratio increased by 55% above the resting level. The peak was reached in 9 s and
the return to basal level took about 20 s. A specific antagonist of the glycine
site on NMDA receptors, 7-chlorokynurenate (10 microM), decreased the calcium
response to glycine by 60%. Glycine may activate NMDA receptors. Glycine may also
activate the strychnine-sensitive glycine receptor-gated channel. Strychnine (50
microM) decreased the calcium response to glycine by 60%. Thus, glycine probably
induces calcium concentration changes in type I vestibular sensory cells via NMDA
receptors and/or glycine receptors.
PMID- 10675641
TI - Classification and culture of spiral ligament fibrocytes from mice.
AB - In this study, we established an immunocytochemical strategy to classify the
fibrocytes of the murine spiral ligament (SL), and SL cultures were
characterized. Similar to those in other mammals, three different types of
fibrocytes were identified. Type I fibrocytes, which are found lateral to the
stria vascularis, showed positive immunoreactivity for caldesmon and S-100
protein and were not stained for sodium-potassium-adenosinetriphosphatase (Na-K
ATPase). Type II fibrocytes are located lateral to the spiral prominence
epithelium and suprastrial region, and they were distinguishable by their
positive staining for Na-K-ATPase. Type III fibrocytes, which are found adjacent
to bone in the inferior region of the SL, contained caldesmon but not S-100 or Na
K-ATPase. Secondary cultures from the SL were positive for caldesmon and S-100
and negative for Na-K-ATPase, suggesting that these cells were type I fibrocytes.
The present immunocytochemical approach was useful for the classification of
murine fibrocyte cultures, and these cultures may benefit future immunological
studies of the inner ear because mice have been well characterized
immunologically.
PMID- 10675642
TI - Cochlear findings in the white spotting (Ws) rat.
AB - White spotting (Ws) rats possess a c-kit gene mutation at the W locus, resulting
in a variety of characteristics including a lack of intermediate cells of the
stria vascularis. The present study employs a light microscope (LM), scanning
(SEM) and transmission electron microscopes (TEM), diaminobenzidine (DAB)
staining techniques and auditory brainstem response (ABR) to investigate the
structure and function of the cochlea in 26 homozygous Ws/Ws rats aged 1-6
months. A slight thinning of the stria vascularis and moderate elevation of ABR
threshold were about the only defects noted in 1 month animals, while older
animals displayed various defects that tended to worsen with age. At 3 months LM
revealed pigment granules in the basal turn of most animals, with a loss of
pigmentation in the upper turns. The stria vascularis and organ of Corti tended
to be well preserved in the lower, pigmented portion, while the upper,
unpigmented portion showed severe strial degeneration and some outer hair cell
loss. DAB staining revealed a well developed strial capillary net throughout the
pigmented portion of the cochlea, with severe degradation in the unpigmented
apical portion. ABR thresholds were slightly elevated over 1 month values. At 6
months great differences in degeneration were noted between right and left ears
of the same animal.
PMID- 10675643
TI - The influence of noise on blood flow in the basilar artery (BA) - measurements
with transcranial color-coded duplex sonography (TCCD).
AB - Acoustic stimuli are being reported as a cause of changes in resistance in the
basilar artery (BA). It was the aim of this study to investigate this effect
under standardized conditions dependent upon the intensity of the evoking
stimulus. Twenty healthy subjects with normal hearing (male/female 14/6; mean age
26.4 years) were exposed to 'pink noise' for periods of 2 min at 75, 85 and 95
dB(A). Parallel to this, the Doppler spectrum of the BA and both the Pourcelot
resistance index and the Gosling pulsatility index were measured by means of
transcranial color-coded Doppler sonography. In comparison with the base value
(at rest) a significant increase in resistance was noted during noise exposure.
The noise-induced resistance changes could be interpreted as a consequence of
changes in activity of the various centers of the auditory pathway and cerebral
function. Further animal experiments may prove the connection between BA blood
flow and resistance and their changes depending on different acoustic stimuli or
different hearing pathophysiology.
PMID- 10675645
TI - Detecting coherent and incoherent frequency modulation.
AB - Three experiments investigated whether or not the auditory system contains a
neural mechanism that is sensitive to differences in the pattern of frequency
modulation imposed on widely separated carriers. Experiment 1 measured the
discrimination between an unmodulated two-tone complex and one in which either
coherent or incoherent frequency modulation was imposed on the two carrier
frequencies. These two frequencies were either 1100+1925 Hz or 1100+2000 Hz, and
the stimuli were presented against a pink-noise background. The method was based
on that used in experiments by Furukawa and Moore (1996), which were previously
interpreted as providing evidence in favour of a mechanism sensitive to FM
coherence. Discrimination was sometimes better for coherent than for incoherent
FM, as reported by Furukawa and Moore, but only for four out of the eight
listeners tested. The remaining experiments excluded those subjects who had shown
no effect of FM coherence in experiment 1. Experiment 2 showed that detection of
a static shift on the carrier frequencies of the two components was better when
the carriers were shifted in the same, compared to the opposite, direction. This
difference occurred regardless of whether the carriers were modulated coherently,
incoherently, or were unmodulated. The experiment also showed that performance
was better when the 1100-Hz carrier was shifted down and the 1925-Hz carrier was
shifted up, compared to when the 1100-Hz carrier shifted up and the 1925-Hz
carrier shifted down. Experiment 3 showed that this difference also applied to
dynamic changes: detection of quasi-linear frequency sweeps (0.5 cycles of
sinusoidal FM) was better when the higher component glided up and the lower
component glided down than vice versa. In the former condition, performance was
as good as with same-direction sweeps. It is concluded that the effects observed
in experiment 1 and by Furukawa and Moore result from the processing of a global
percept arising from the perceptual fusion of the two carriers, and do not
represent an across-frequency mechanism sensitive to FM coherence. In addition,
it is argued that experiments 2 and 3 demonstrate the existence of perceptual
asymmetries in hearing.
PMID- 10675644
TI - Hyperactivity in the dorsal cochlear nucleus after intense sound exposure and its
resemblance to tone-evoked activity: a physiological model for tinnitus.
AB - Intense tone exposure induces increased spontaneous activity (hyperactivity) in
the dorsal cochlear nucleus (DCN) of hamsters. This increase may represent an
important neural correlate of noise-induced tinnitus, a condition in which sound,
typically of very high pitch, is perceived in the absence of a corresponding
acoustic stimulus. Since high pitch sounds are thought to be represented in
central auditory structures by the place of activation across the tonotopic
array; it is therefore possible that the high pitch of noise-induced tinnitus
occurs because intense sound exposure induces a tonotopic distribution of chronic
hyperactivity in the DCN similar to that normally evoked only under conditions of
high frequency stimulation. To investigate this possibility we compared this tone
induced hyperactivity with the activity evoked in normal animals by presentation
of a tone. This comparison revealed that the activity in the DCN of animals which
had been exposed to an intense 10 kHz tone 1 month previously showed a striking
similarity to the activity in the DCN of normal animals during presentation of
low to moderate level tonal stimuli of the same frequency. In both test
conditions similar patterns were seen in the topographic distribution of the
increased activity along the tonotopic axis. The magnitude of hyperactivity in
exposed animals was similar to the evoked activity in the normal DCN responding
to a stimulus at a level of 20 dB SL. These results suggest that the altered DCN
following intense tone exposure behaves physiologically as though it is
responding to a tone in the absence of a corresponding acoustic stimulus. The
relevance of these findings to noise-induced tinnitus and their implications for
understanding its underlying mechanisms are discussed.
PMID- 10675646
TI - Middle ear influence on otoacoustic emissions. I: noninvasive investigation of
the human transmission apparatus and comparison with model results.
AB - Evoked otoacoustic emissions (EOAEs) are generated within the cochlea in response
to external sounds, and they can be acoustically detected in the external
auditory meatus after backward propagation through the middle ear. In addition to
being used to probe the cochlear mechanisms, they are expected to be sensitive to
minute changes in middle ear impedance. Systematic measurements of the changes in
the vectorial components of EOAEs were carried out after various manipulations of
the human middle ear in order to characterize the influence of stiffness and
inertia of the stapes and tympanic-membrane systems. For this purpose, stapedius
muscle contractions were elicited by high-level contralateral sound, controlled
changes in middle ear pressure (range +/-100 daPa) were produced and the tympanic
membrane was loaded with water droplets. A computer model of the middle ear
network was implemented using a standard lumped-element electric analog of the
middle ear (Zwislocki's model). Forward and backward transmission changes were
simulated and model predictions were compared to experimental data. Apart from
the case of positive middle ear pressures, a close qualitative correspondence was
found between model and real-ear results. Each of the effects was characterized
by a unique pattern of phase and magnitude changes as a function of frequency, in
relation to the mechanical characteristics of the involved subsystem (i.e. stapes
stiffness, tympanic-membrane stiffness or mass) and its resonance properties.
Owing to their high sensitivity, EOAEs could be helpful for an accurate
individual multifrequency analysis of middle ear impedance by comparisons under
rest and test conditions.
PMID- 10675647
TI - Middle-ear influence on otoacoustic emissions. II: contributions of posture and
intracranial pressure.
AB - Although it seems likely that body tilt or surgically provoked variations in
intracranial pressure (ICP) can result in variations of intralabyrinthine
pressure, the channels for pressure transmission remain controversial and the
reasons why evoked otoacoustic emissions (EOAEs) exhibit attendant modifications
are unclear. The theoretical framework implemented in the companion paper [Avan
et al. part I, 2000] provides sensitive and non-invasive means to identify the
middle-ear mechanism(s) entailed in EOAE changes. It was thus applied to analyze
the influence of posture on EOAE phases and magnitudes as a function of
frequency, in a series of experiments involving body tilt from sitting to supine
(0 degrees or -30 degrees ). Controlled ICP variations were surgically carried
out in a series of hydrocephalic patients and the resulting EOAE changes were
compared to posture data and model predictions. In all cases, the EOAE changes
closely resembled those due to an increase in the stiffness of the stapes'
annular ligament, in keeping with the assumption that ICP gets transmitted to
intralabyrinthine spaces and modifies the hydrostatic load on the stapes, thereby
influencing EOAE features. A small additional contribution of middle-ear pressure
to EOAE changes was identified in addition to the main stapes component.
Dynamical EOAE measurements showed that sudden ICP changes were transmitted to
the inner ear within 8-30 s. The high sensitivity of EOAE phases below 2 kHz to
ICP changes, together with the absence of any significant confounding middle-ear
effect, favors EOAEs for a reliable non-invasive monitoring of ICP and
intralabyrinthine pressures.
PMID- 10675648
TI - Technical report: chronic and acute intracochlear infusion in rodents.
AB - As a follow-up to the Brown et al., 1993 technique, we have made several
improvements to the micro-cannula, osmotic pump procedure, enabling chronic
intracochlear infusions while maintaining hearing. In addition, acute bolus
injection techniques are briefly described in guinea pig, rat and mouse.
PMID- 10675649
TI - Amyloid precursor protein gene isoforms in Alzheimer's disease and other
neurodegenerative disorders.
AB - Differential expression of the amyloid precursor protein gene (APP) may be
important in the development of amyloidosis in Alzheimer's disease (AD) and
experimentally in the brain's response to injury. Controversial data suggests
that APP isoforms containing the Kunitz protease inhibitor isoform (APP KPI+) are
over expressed in the brains of patients with AD when compared to the non-Kunitz
protease inhibitor containing isoforms (APP KPI-). We have investigated this
hypothesis using a quantitative analysis of gene expression on brain tissue
collected at post-mortem. In situ hybridization has been used with synthetic
oligonucleotide probes labelled with 35S to detect the two principal splice
variants of APP: APP 695 (KPI-) and APP 751 (KPI+). A prospective brain bank of
frozen brain specimens has been established and includes pathologically proven AD
(n=15) and other neurodegenerative disorders as controls (n=18). The controls
consist of frontal lobe atrophy (n=4), Huntington's disease (n=5), Parkinson's
disease (n=4), motor neuron disease (n=2), multi-infarct dementia (n=1),
multisystem atrophy (n=1), and subacute sclerosing panencephalitis (n=1). We have
observed no significant differences in the expression of APP 695 KPI- mRNA in
frontal lobe: 17.49+/-3.26 optical density (OD) units of mRNA expression in AD
vs. 16.13+/-1.76 OD units mRNA in controls (P=0.80, linear regression); or
temporal lobe: 14.73+/-2.96 in AD vs. 16.49+/-2.15 in controls (P=0.55). No
significant differences have been found in APP 751 KPI+ in frontal lobe: 12.86+/
2.98 in AD vs. 13.70+/-2.88 in controls (P=0.97); and temporal lobe: 13.31+/-4.93
in AD vs. 11.07+/-1.99 in controls (P=0. 65). Analysis of the ratios of APP 751
KPI+ OD units of mRNA to APP 695 KPI- mRNA revealed a trend to an increased ratio
which did not reach statistical significance: frontal lobe APP 751 KPI+/APP 695
KPI- 1.92+/-1.04 in AD vs. 0.86+/-0.17 in controls (P=0.54); temporal lobe 2.54+/
1.59 in AD vs. 0.96+/-0.11 controls (P=0.34). Our data has not revealed
differential expression of APP mRNA isoforms in AD and supports the hypothesis
that post-translational events in APP metabolism are important in amyloidogenesis
and the pathogenesis of AD.
PMID- 10675650
TI - Inhibition of synaptosomal [3H]glutamate uptake and [3H]glutamate binding to
plasma membranes from brain of young rats by glutaric acid in vitro.
AB - Synaptosomes and plasma membrane preparations from brain of 30-day-old rats were
incubated with glutaric acid at final concentrations ranging from 10 nM to 1 mM
for the determination of glutamate uptake and binding, respectively.
[3H]Glutamate uptake into synaptosomes was inhibited by approximately 50% by 1 mM
glutaric acid, corresponding to the concentration found in brain of glutaric
acidemic children. In addition, in the presence of extracellular Na+
concentrations, the same dose of glutaric acid decreased by about 30%
[3H]glutamate binding to brain plasma membranes. The results indicate that the
inhibition of both glutamate uptake into synaptosomes and glutamate binding to
plasma synaptic membranes by the metabolite could result in elevated
concentrations of the excitatory neurotransmitter in the synaptic cleft,
potentially causing excitotoxicity to neural cells, a fact that may be related to
the brain damage characteristic of glutaric acidemia type I.
PMID- 10675651
TI - Detection of DNA fragmentation of myonuclei in myotonic dystrophy by double
staining with anti-emerin antibody and by nick end-labeling.
AB - To clarify the occurrence of apoptosis in skeletal muscle in pathological
conditions, we studied 44 muscle biopsy specimens by immunohistochemical staining
with monoclonal antibody against emerin, which is localized in muscle nuclear
membrane, and by ApopTag Plus to detect DNA fragmentation. Five of six patients
with myotonic dystrophy (DM) showed three to 35 myonuclei stained with anti
emerin antibody and ApopTag Plus in 1500 muscle fibers. Four of the 18 patients
with polymyositis, one of those with thyroid myopathy and one with neurogenic
atrophy showed a few myonuclei stained positively by these methods. Our study
revealed that DNA fragmentation in myonuclei occurred in skeletal muscle fibers
regardless of the type of disease, although the frequency was rather low in all
of these diseases except DM. The DNA fragmentation detected in most of the
patients with DM suggested a significant role of apoptosis in the pathomechanism
of this disease.
PMID- 10675652
TI - Lesions visualized by contrast-enhanced magnetic resonance imaging in transient
ischemic attacks.
AB - In patients with transient ischemic attacks (TIAs), contrast-enhanced magnetic
resonance imaging (MRI) is more sensitive to visualize the recent ischemic
lesions than conventional MRI. We examined the clinical characteristics of TIA
patients presenting with enhanced lesions visualized by contrast-enhanced MRI. We
retrospectively evaluated 64 patients with carotid TIAs. We evaluated the
frequency and topography of TIA associated infarcts on contrast-enhanced MRI and
compared the clinical background of patients with and without such lesions.
Twenty-three patients underwent plain MRI only, while the remaining 41 patients
underwent contrast-enhanced MRI. Of the latter 41 patients, 16 had abnormal
enhanced lesions (39%: group L), while 25 had no lesions (61%: group NL). In
group L, all lesions were spotty, and they were located in the cerebral cortex in
13 patients (81%), the subcortex in two (12%), and the perforator territory in
one (6%). Aphasia or confusional state, hypertension, and emboligenic cardiac or
arterial disease (stenosis > or =50%) were more frequently observed in group L
than in group NL (38 vs. 8%, 81 vs. 48%, and 93 vs. 60%, respectively, P<0. 05).
The TIA patients with enhanced lesions on MRI may be associated with an
emboligenic cardiac or arterial disease, severe neurologic symptom compared to
those without them.
PMID- 10675653
TI - Cerebral atrophy in multiple system atrophy by MRI.
AB - Cranial magnetic resonance images (MRI) of the cerebral areas of 40 patients with
multiple system atrophy (MSA) and of 61 age-matched controls were analyzed. The
cerebral area of MSA patients was 131. 95+/-15.89 cm(2) (mean+/-S.D.), which was
significantly smaller than that of normal controls at 149.01+/-10.93 cm(2)
(P<0.0001). All 23 MSA cases subjected to the MRI study over a 1-year period
showed progressive cerebral atrophy, and the atrophy rate was 2.46+/-1. 66%/year.
There were no significant differences within the MSA subtypes or between gender.
The progression of cerebral atrophy in MSA correlated more with duration (r=
0.634) than age (r=-0.421). We conclude that MRI findings throughout the course
of MSA suggest progressive cerebral atrophy, which is common in all subtypes and
reflects duration of the disease rather than age.
PMID- 10675654
TI - The recovery potential of central conduction disorder in hypothyroid rats.
AB - In an aim to detect the dysfunction of central nervous system among rats with
varied durations of hypothyroidism and to elucidate the recovery potential after
thyroxine replacement, a series of BAEP were conducted and compared with age
matched controls. BAEP was performed in five groups of the hypothyroid animals 1,
3, 5, 7, and 9 months after thyroidectomy respectively. Following initial
electrophysiological assessment, thyroxine replacement was administered to each
group of hypothyroid rats, and BAEP was performed at two month intervals, up to
two successive normal studies or six months after the initiation of therapy,
whichever came first. Before thyroxine treatment, prolonged I-V interpeak latency
was the most consistent abnormal finding in all groups of hypothyroid rats, and
longer hypothyroid state correlated well with more severe central conduction
disorder. Hearing impairment was also noted among those with long duration of
hypothyroidism. After thyroxine replacement, the central conduction dysfunction
usually returned to normal if the hypothyroid state was not more than 5 months in
duration. However, when hypothyroid state persisted over 7 months or more, there
would be an incomplete recovery for central conduction disorder. The present
study brings out the concept of 'therapeutic window' in reversing the central
nervous dysfunction caused by hypothyroidism in adult rats.
PMID- 10675655
TI - Vergence disorders in patients with spinocerebellar ataxia 3/Machado-Joseph
disease: a synoptophore study.
AB - Diplopia, a common symptom in spinocerebellar ataxia 3/Machado-Joseph disease
(SCA3/MJD) cases, is not always due to asymmetric ophthalmoplegia. We found a
Japanese SCA3/MJD family, in which three patients clearly had an impairment of
divergence eye movement. We thus quantitatively examined the vergence ranges in
eight Japanese SCA3/MJD cases using the synoptophore test. An impairment of the
vergence eye movements was found in all patients, and the vergence impairment
pattern, but not the ophthalmoplegia pattern, was found to be compatible with the
diplopia pattern. The diplopia in SCA3/MJD cases is, therefore, attributed, at
least in part, to the impairment of the vergence eye movements.
PMID- 10675656
TI - What's in a smile?: Quantification of the vertical smile of patients with
myasthenia gravis.
AB - Many patients with myasthenia gravis who experience bulbar symptoms show a
vertical smile, which may have a considerable, and often underestimated, impact
on social life. Peri-oral muscle function can be quantified by calculating lip
length and snout indices, which indicate the degree to which a person is capable
of smiling and of pursing the lips, respectively. In the present study patients
with bulbar myasthenia gravis were compared to patients with ocular myasthenia
gravis, patients now in remission (but previously suffering from bulbar
myasthenia gravis), and healthy subjects. The lip-length and snout indices of
patients with bulbar myasthenia gravis were significantly lower than those of the
other groups. The facial impairments were no longer detectable in patients with
bulbar myasthenia gravis in remission and no subclinical impairments in lip
length and snout indices were found in the ocular myasthenia gravis group. These
findings were consistent with the patients' reports of impairment of smiling and
other oral functions. The patients suffering from a vertical smile or other oral
impairments were well aware of their condition, most probably because of the
social consequences of being unable to smile. The indices could be of importance
in the longitudinal evaluation of therapy in individual patients and in
pharmacotherapeutical research. We found a low correlation between the lip-length
and snout indices, which reflects the capricious pattern of involvement of
separate muscles in myasthenia gravis. Therefore both indices deserve special
attention if they are used for monitoring myasthenic symptoms.
PMID- 10675657
TI - The spectrum of chronic inflammatory demyelinating polyneuropathy.
AB - Research criteria for the diagnosis of chronic inflammatory demyelinating
polyneuropathy (CIDP) were proposed by an Ad Hoc Subcommittee of the American
Academy of Neurology (AAN) in 1991, and since then these criteria have been
widely used in clinical studies. We have been impressed by the frequent finding
of electrophysiological changes of a demyelinating neuropathy in patients whose
clinical presentation does not conform to the usually accepted clinical phenotype
of CIDP. To determine the clinical spectrum of CIDP, we conducted a retrospective
review of patients of the peripheral electrophysiology laboratory of the
University of Miami-Jackson Memorial Medical Center. Diagnostic criteria for
acquired demyelination of an individual nerve were adapted from the AAN research
criteria for the diagnosis of CIDP (1991). Patients were accepted for inclusion
when such evidence was demonstrated in at least one motor nerve or at least two
sensory nerves. We then reviewed the clinical phenotype and the underlying
etiology of the neuropathy in these cases. Eighty-seven patients, 63 male and 24
female, age of onset 4-84 (mean 49.3) years, met these inclusion criteria. Forty
seven patients (54%) had distinct features outside the usual clinical
presentation of CIDP. Of these, 15 (17%) had predominantly distal features, 13
(15%) had exclusively sensory polyneuropathy; seven (8%) had markedly asymmetric
disease, seven (8%) had associated CNS demyelination, four (5%) had predominant
cranial nerve involvement, and one (1%) had only the restless legs syndrome. An
associated medical condition that may have been responsible for the acquired
demyelinating neuropathy was present in 60% of the patients. We conclude that
spectrum of CIDP is broader than would be indicated by the strict application of
the AAN research criteria, and that many of the cases meeting more liberal
criteria frequently respond to immunosuppressive therapy.
PMID- 10675658
TI - Migraine, but not subarachnoid hemorrhage, is associated with differentially
increased NPY-like immunoreactivity in the CSF.
AB - To test whether migraine and subarachnoid hemorrhage (SAH) are associated with
increased sympathetic tone, we compared the neuropeptide Y-like (NPY-LI) and
chromogranin A-like immunoreactivities (LI) of cerebrospinal fluid (CSF) from
migraneurs and SAH patients with those from control subjects. Increased
sympathetic tone was expected to produce higher co-release of these co-stored
peptides and concordant changes in their CSF levels. In addition, we investigated
a possible disturbed nitric oxide homeostasis by measuring CSF nitrites (NO).
More than 70% of CSF NPY-LI corresponded to the chromatographic peak (HPLC) for
the intact molecule in all three groups. Migraneurs had 64% higher CSF NPY-LI,
but no significant difference in CSF chromogranin A-LI, as compared to controls.
In contrast, SAH patients had 74% less CSF chromogranin A-LI and a trend to lower
NPY-LI, as compared to controls. No differences in CSF NO were detected among
groups. These results argue against an increased sympathetic tone in patients
with either migraine or SAH, and suggest that the higher CSF NPY-LI of migraneurs
probably originates from central neurons. Furthermore, our findings in SAH
patients argue in favor of a decreased sympathetic tone; this could be a
homeostatic response to counterbalance vasoconstriction mediated by other
mechanisms.
PMID- 10675659
TI - Analysis of the mRNA transcripts of the survival motor neuron (SMN) gene in the
tissue of an SMA fetus and the peripheral blood mononuclear cells of normals,
carriers and SMA patients.
AB - Spinal muscular atrophy (SMA) is a disorder characterized by degeneration of the
anterior horn cells of the spinal cord. The gene most highly associated with SMA
is the survival motor neuron (SMN) gene. In this study, we present an analysis of
messenger RNA (mRNA) expression of the SMN gene in peripheral blood mononuclear
cells in normal subjects, SMA carriers and patients from 20 SMA families. We
found at least 6-8 different transcripts of SMN gene formed by alternative
splicing involving exons 3, 5 and 7. We compared transcripts from the different
types of SMA and found no definite differences in transcript patterns and
amounts. Normal subjects with the telomeric SMN (SMN(T)) gene only had variable
splicing resulting in several transcripts, the most dominant being a transcript
containing all coding regions. However, SMA patients with the centromeric SMN
(SMN(C)) gene only had a higher degree of splice variation and tended to show
little or no exon 7. These results demonstrate that SMN(T) and SMN(C) genes
participate in alternative splicing phenomena. The different splicing patterns
support the view that the SMN(T) gene is responsible for SMA disease. We also
analyzed the transcripts from several tissues of an SMA fetus who had a
homozygous SMN(T) gene deletion. Different splicing patterns were also found in
these tissues, and were similar to the splicing pattern of leukocytes. We
compared the major transcripts from exons 4 to 8 of both the SMN(T) and SMN(C)
genes and found that the relative proportion varied among normal subjects, SMA
carriers and patients. This approach could be used as a novel diagnostic method.
We suggest that analyzing the mRNA expression of the SMN gene in peripheral blood
mononuclear cells offers an apparently reliable technique for separating SMA
patients, carriers, and normal individuals.
PMID- 10675660
TI - A new diagnostic procedure to detect unknown transthyretin (TTR) mutations in
familial amyloidotic polyneuropathy (FAP).
AB - Two patients with amyloidosis caused by transthyretin (TTR) were investigated by
immunohistopathologic, mass spectrometric, and molecular genetic methods. After
confirming the immunoreactivity of TTR in the amyloid deposits using anti-TTR
polyclonal antibody, a new method: centrifugal concentration and electrospray
ionization mass spectrometry (ESI-MS) was employed to detect the variant TTR in
the serum. Only 50 microl of the serum and 30 microl of the anti-TTR antibody
were needed for the analysis. After incubation with the antibody, the samples
were passed through a 1000 kDa cut off centrifugal concentrator to retain the
antibody, thereafter, the filtrate was analyzed by ESI-MS. Several forms of
normal and variant TTR were detected in the serum samples: unconjugated TTR,
cysteine and cysteine-glycine conjugated TTR. In the patients, a variant form of
TTR was detected with a 26.0 Da higher molecular weight than that of normal TTR.
Single-strand conformation polymorphism (SSCP) and direct sequence analysis
confirmed the presence of a one-base substitution situated at the codon 50 from
AGT (Ser) to ATT (Ile) in both patients, that corresponded to the increased
molecular weight of 26.0. The present diagnostic procedure demonstrates the
usefulness of both ESI-MS and SSCP to screen for TTR related amyloidosis rapidly.
Moreover, the DNA samples obtained from the band showing abnormal electrophoretic
migration pattern in SSCP, facilitate the direct sequence analysis to detect the
unknown mutation, and the observed shift in molecular weight of the variant TTR
in ESI-MS confirms the base substitution.
PMID- 10675661
TI - Factor structure of trunk performance data for healthy subjects.
AB - OBJECTIVE: To examine the factor structure of various measurements of trunk
muscle performance for healthy subjects. DESIGN: A total of 22 performance scores
were collected and their univariate and multi-variate relationships were
examined. BACKGROUND: Extensive literature exists on the measurement of trunk
performance data and the relationships between measurements but what needs to be
collected to realize a true performance score remains unclear. METHODS: Trunk
muscle performance scores of 150 subjects (71 males and 79 females) were obtained
on an Isostation B-200 Dynamometer. Twenty-two parameters measuring range of
motion, isometric strength, velocity, and endurance on all three planes of motion
were collected. The factor structures were constructed using Principal Components
Analysis. RESULTS: Clear-cut factor patterns (explained 96.3% of the total
variance) suggests that the five-factor structure might be valid and appropriate
for this population. The major loading on each factor indicated that: Factor 1
could be labeled as a static strength measure; Factor 2 as velocity; Factor 3 as
flexibility; and Factors 4 and 5 as fatigue-resistance. CONCLUSIONS: No single
mode of measurement can provide a good representation of a total trunk muscle
performance. RelevanceFor the realization of trunk muscle performance, clinics
have to measure all modes of isometric strength, velocity, range of motion, and
endurance. Care must be taken in eliminating any parameter.
PMID- 10675662
TI - Ultrasonic quantification of osseous displacements resulting from skin surface
indentation loading of bovine para-spinal tissue.
AB - OBJECTIVE: To validate an ultrasound-based technique which quantifies uni-planar
subcutaneous displacement of an osseous object resulting from an externally
applied load. BACKGROUND: Many spinal conditions are thought to be characterized
by aberrant vertebral displacements yet the invasive nature of many investigative
techniques has left the clinical significance of this relation incompletely
understood. METHOD: Six bovine bone/paravertebral tissue preparations were
indented by one of two ultrasonic transducers (5 and 7 MHz) fitted to an
electromechanical actuator. The resulting osseous displacement along the
principal indentation axis was calculated by subtracting the change in
transducer/bone distance between ultrasonic images collected at tissue contact
and maximal load from the change in actuator displacement. A dial gauge
contacting the bone was used as a displacement criterion measure. RESULTS: Using
the 7 MHz transducer, the mean error of the technique was 6.74% (SD=3.98) while
the mean error associated with the 5 MHz transducer was 12.73% (SD=7.49).
CONCLUSIONS: This non-invasive technique is capable of quantifying subcutaneous
uni-planar bone displacement with an accuracy comparable to similar invasive
techniques over a comparable displacement range. RelevanceThis non-invasive
technique may be beneficial in assessing the significance of vertebral
displacements in conditions such as hypermobility and osteoarthritis, as well as
in studies of manipulative therapy.
PMID- 10675663
TI - Description of the relation between the forces acting in the lumbar spine and
whole-body vibrations by means of transfer functions.
AB - OBJECTIVE: The purpose of this study was to display the relationships between the
forces transmitted in the spine and the accelerations of the vibrating seat.
BACKGROUND: Investigations reveal that exposure to whole-body vibration can
induce degenerative changes in the lumbar spine. Elevated spinal forces are
probably the crucial component in the pathogenesis of this disease. DESIGN AND
METHODS: The spinal forces are simulated by means of a biomechanical model, where
16 rigid bodies represent the upper body and the arms of a sitting operator. The
relationships between seat accelerations and spinal forces are displayed as
frequency-dependent transfer functions. RESULTS: Spinal forces are not only
elevated in the direction parallel to the vibration excitation but also in the
two other orthogonal vibration directions. According to the magnitudes of the
transfer functions the highest oscillating parts of the forces are reached at
frequencies below 10 Hz. CONCLUSIONS: Using the transfer functions, the time
course of the spine forces can be computed and a new kind of weighting function
can be derived which enables a force related weighting of the seat acceleration.
RelevanceVibration induced health risks are commonly assessed by the weighted
acceleration (ISO 2631-1). These weighting factors resulted from subjective
magnitude sensation. It is argued that a more valid assessment will be obtained
if the accelerations are weighted in relation to spinal forces. These forces
cannot be measured directly under vibration. However, they can be simulated by
means of biomechanical models.
PMID- 10675664
TI - The bursal and articular sides of the supraspinatus tendon have a different
compressive stiffness.
AB - OBJECTIVE: To measure the compressive stiffness of the supraspinatus tendon and
to determine whether regional difference exists in the bursal and articular side
of the tendon. DESIGN: Indentation testing was performed on both the bursal and
articular sides of the supraspinatus tendon, focused on the 'critical area',
where rotator cuff tears often occur. BACKGROUND: When the supraspinatus tendon
wraps around the humeral head or is under impingement condition, compressive
force on the tendon surface is expected. Therefore, compressive stress has been
recently considered to be one of the important factors associated with the cuff
tear. The mechanical properties would be essential for analytic modeling of
stress distribution. METHODS: Indentation tests were performed at 15 locations on
the bursal and articular surfaces of the supraspinatus tendon. A mathematical
model with exponential relationship was used to describe the measured force
deformation relationship and to calculate the compressive stiffness of the
supraspinatus tendon. RESULTS: The over-all initial stiffness on the bursal and
articular sides of the tendon was significantly different. On the bursal side,
the anterior third had a significantly higher initial stiffness than the other
thirds on average. On the articular side, initial stiffness at location 10 mm
proximal to the greater tuberosity was significantly higher than the rest on
average. CONCLUSIONS: The compressive stiffness of the supraspinatus tendon was
found to be non-homogenous throughout the structure.RelevanceNon-homogenous
compressive stiffness of the supraspinatus tendon would affect the load
transmission within the tendon, which might be associated with the potential
mechanism of tear. Such characteristics needs to be considered when performing
finite element modeling of stress fields in the tendon.
PMID- 10675665
TI - Three-dimensional measurement of cemented femoral stem stability: an in vitro
cadaver study.
AB - OBJECTIVE: To compare the in vitro stability of two cemented hip stem designs:
Stem I was a collarless, double-tapered, highly polished implant; Stem II had a
collar and matt finish. BACKGROUND: Stability of the femoral component of a hip
implant is important for its long-term clinical success. Excessive migration or
cyclic motion can increase the risk of early implant failure. METHODS: The stems
were implanted in paired human cadaver femurs, and custom-designed micromotion
sensors were used to measure three-dimensional motions of the stems at proximal,
middle and distal locations during simulated in vivo loading cycles. RESULTS:
This study found that despite 'rigid' fixation, cemented stems exhibit detectable
motions under a limited number of cycles of simulated physiologic loads. At four
times the donor body weight, Stem I showed a subsidence of 90 microm, compared to
25 microm of Stem II (P<0.05). In contrast, the proximal end of Stem II exhibited
greater cyclic motions in the medial-lateral direction (P<0.05). CONCLUSIONS: The
different motion patterns could be due to the design differences, such as surface
finish and geometry. RelevanceImplant design is an important factor related to
the behavior of the cement/bone interface and the overall success of the implant.
This study compares in vitro micromotion of two cemented femoral prostheses with
differing proximal designs.
PMID- 10675666
TI - Determination of hydrodynamic drag forces and drag coefficients on human leg/foot
model during knee exercise.
AB - OBJECTIVE: The purpose of this laboratory experiment was to measure hydrodynamic
drag forces in barefoot/hydro-boot conditions and accordingly, to determine the
coefficients of drag on human leg/foot model during simulated knee extension
flexion exercise. DESIGN: The prosthesis of the human lower leg was set in a
water tank and connected into an isokinetic force dynamometer to measure
resistive forces during knee motion. BACKGROUND: Quantifying resistance for
aquatic exercises has been a challenge in hydrotherapy. The use of models of
foot/leg provides a practical method to calculate coefficients of drag and to
estimate resistance for rehabilitation purposes in musculoskeletal and amputee
patients. METHODS: The dynamometer produced constant angular velocities of 250
degrees /s, 270 degrees /s and 300 degrees /s to the prosthesis. The baseline for
measurements was performed in barefoot condition. A hydro-boot was used to study
effects of increased frontal area (30%) of the leg on drag forces and
coefficients. RESULTS: The maximal drag force values were 61 N (300 degrees /s)
in barefoot and 270 N (270 degrees /s) in hydro-boot condition. Related drag
coefficient values during the range of motion were from 0.3 to 0.1 and from 1 to
0.8, respectively. CONCLUSIONS: Drag force and related drag coefficient were
highest during the early part of extension (150-140 degrees flexion) as the model
was opposing the lift forces with the influence of water resistance. The effect
of velocity was remarkable on drag forces but minimal on drag coefficient values.
RelevanceThe drag forces and coefficients of this experiment can be clinically
utilised to calculate hydrodynamic forces to develop progressive knee exercise
programs as well as to design of prosthesis for amputee patients.
PMID- 10675667
TI - Passive stiffness characteristics of ankle plantar flexors in hemiplegia.
AB - OBJECTIVE: To assess the feasibility and reliability of ankle plantar flexor
stiffness measurements in hemiplegia. DESIGN: Repeated measurements in five
consecutive weeks. BACKGROUND: In hemiplegia, an equinovarus positioning of the
foot might be caused by an increased stiffness of the m. triceps surae. METHODS:
In eight hemiplegic patients the net joint torque of passive muscle stretch was
measured as a function of ankle-angle by a dynamometer, at both sides. Ankle
stiffness was characterised and also a biomechanical model of the passive muscle
was fitted. RESULTS: In the vast majority of measurements it was possible to
obtain measurements that were not distorted by involuntary muscle contraction.
These measurements showed for the angle at which a passive plantar moment of 10 N
m was reached a standard error of measurement of less than 2.7 degrees. The
muscle model showed the increased stiffness as a shortening of the muscle-fibre
length. CONCLUSION: The feasibility of this method to measure muscle stiffness
was fair to good in hemiplegic patients. Provided the abandoning of involuntary
muscle activity, the reproducibility warrants application in clinical practice at
an individual level. The use of the model relates this changes to a shortened m.
soleus and/or m. gastrocnemius. RelevanceEffective clinical decisions for
treatment of equinovarus positioning of the foot in the hemiplegic individual,
should consider excessive involuntary contractions of the m. triceps surae
complex (i.e., spasticity), as well as shortened muscle tissue resulting in high
stiffness. Despite the importance of increased stiffness there have been no
validated methods of measurement.
PMID- 10675668
TI - Foot progression angle and ankle joint complex in preschool children.
AB - OBJECTIVE: The influence of foot progression angle on the ankle joint and the
effects on gait patterns and mechanisms in skeletally normal preschool children
was investigated. DESIGN: Kinematics and kinetics of the ankle joint were
analyzed for preschool children who were skeletally normal but walked with
different foot progression angle. BACKGROUND: The most frequent reasons for
preschool children to be brought to a paediatric orthopaedic clinic are toe-in
and toe-out. Without understanding the biological and biomechanical implications,
treatment for these problems can be very confusing. METHODS: Gait analysis was
performed in 86 skeletally normal preschool children. Children were grouped
according to their foot progression angles. Analysis of the kinematics and
kinetics of the ankle joint was intended to elucidate the gait mechanism.
RESULTS: Children with different foot progression angles had distinctive patterns
of spatio-temporal parameters, ground reaction force, joint angle, moment, power,
and mechanical work of the ankle joints. The differences were organized and
explained as different walking patterns and tactics. CONCLUSIONS: Skeletally
normal preschool children with excessive toe-in or toe-out foot progression
angles are not necessarily in some diseased status. They were instead related to
different walking patterns. Aggressive treatment for these problems is not
recommended.RelevanceThese results suggest that toe-in and toe-out are related to
walking speed which has distinct influences on the kinematics and kinetics of the
ankle joint. Though the observed problems were seemingly only in the transverse
plane, they are in fact three-dimensional and have a mutually close relationship.
The findings could be linked to the promptness of muscle response and the habits
of walking in preschool children. Better understanding of possible mechanisms
will help parents and paediatricians decide on the most appropriate treatment for
these children.
PMID- 10675669
TI - A study of in-shoe plantar shear in patients with diabetic neuropathy.
AB - OBJECTIVE: To quantify in-shoe plantar shear in diabetic neuropathic feet.
DESIGN: Plantar shear stresses are measured in a group of six patients with a
history of diabetic neuropathic ulceration. BACKGROUND: Although elevated
pressure between foot and shoe frequently found in diabetic neuropathic patients
has been linked to a raised incidence of plantar ulceration, the shear component
of stress at this interface is as yet unquantified. It is suggested that its
effects may be equally damaging. METHODS: Measurements of shear were made locally
beneath the medial four metatarsal heads and heel during unpaced gait in
orthopaedic footwear, using a bi-axial magneto-resistive shear transducer.
Similar methodology was previously employed on a group of asymptomatic adults,
thereby allowing comparisons to be made. RESULTS: Overall the maximum shear
stress for this patient group (73 kPa) was not significantly different to that in
the asymptomatic group (87 kPa). However the patient group exhibited lower
magnitudes of shear stress under the third/fourth metatarsal heads (average 51/39
vs. 86.5/71 kPa, respectively) and higher magnitudes under the first/second heads
(73/64 vs. 35/31 kPa, respectively), indicating a medial shift. Step-to-step
variability of maximum shear measured under the third metatarsal head showed an
increase in the transverse component (coefficient of reliability 67% vs. 98%).
CONCLUSIONS: Although the overall patterns of shear are broadly similar to the
asymptomatic group, these pilot trials indicate a medial shift in shear loading
under the forefoot coupled to increased step-to-step variability in the diabetic
group. RelevanceMechanical stress at the plantar interface between foot and shoe
is of particular clinical relevance to the formation and management of ulcers in
diabetic neuropathy. Whereas the pressure component of stress is widely studied,
the shear component is poorly described although it may be of equal importance.
PMID- 10675670
TI - Mechanical properties of collagen fascicles from in situ frozen and stress
shielded rabbit patellar tendons.
AB - OBJECTIVE: To know the effects of stress shielding on the biomechanical
properties of collagen fascicles obtained from in situ frozen patellar tendons
(an autograft model). DESIGN: Collagen fascicles of approximately 300 microm in
diameter were obtained from in situ frozen rabbit patellar tendons and also from
in situ frozen and stress-shielded ones, and their mechanical properties and
fibroblast density were determined. BACKGROUND: Stress shielding changes the
mechanical properties of in situ frozen patellar tendons in which there exist no
fibroblasts. The mechanisms of this phenomenon have not been studied well.
METHOD: Patellar tendons of both in situ frozen group and in situ frozen and
stress-shielded group were frozen in situ by liquid nitrogen to kill fibroblasts.
Then, in the in situ frozen and stress-shielded group, no tension was applied to
the tendons for 2, 3, and 6 weeks, while normal tension was applied to the
tendons of the in situ frozen group. Tensile properties of the collagen fascicles
obtained from these tendons were determined using a microtensile tester, and were
compared to the collagen fascicles from non-frozen, stress-shielded patellar
tendons. RESULTS: Tangent modulus and tensile strength of collagen fascicles from
the in situ frozen and stress-shielded group progressively decreased with the
time of stress shielding; however, these decreases were much smaller than those
of the fascicles obtained from non-frozen, stress-shielded tendons. Although
there were few fibroblasts in the patellar tendon of the in situ frozen and
stress-shielded group at 2 weeks, the modulus and strength of the fascicles from
the posterior portion were significantly lower than those in the in situ frozen
group. In addition, the reduction of strength caused by stress shielding was much
smaller in collagen fascicles than in bulk patellar tendons. CONCLUSION: The
mechanical properties of collagen fascicles in in situ frozen tendons (an
autograft model) are affected by stress shielding even under acellular condition.
RelevanceThe in situ frozen, stress-shielded patellar tendon is a model of
augmented autografts which are clinically used for the reconstruction of injured
anterior cruciate ligaments. The sub-macroscopic studies of the tendon are useful
to understand the mechanisms of the reduction of graft strength and its gradual
recovery observed after reconstruction.
PMID- 10675671
TI - The effect of lumbar back support tension on trunk muscle activity.
AB - OBJECTIVE: Assess the effect of different controlled lumbar back support
tightness levels on trunk muscle activity. DESIGN: Two-way repeated measure
design assessing lumbar back support tension and submaximal trunk extension
moments on trunk muscle electromyographic activity. BACKGROUND: Biomechanical
studies on lumbar back supports often use electromyography (EMG) to assess the
affect on trunk muscle activity. However, the lumbar back support may alter the
electromyographic signal by changing the electrode-muscle distance. METHODS:
Subjects performed trunk extensions at three static submaximal extension moment
levels (25%, 50% and 75% MVC) while stabilized at the hips and shoulders, with
the back support tensioned to three different tightness levels (44.5, 66.7 and
89.0 N) as well as a no-back support condition. RESULTS: Statistical analysis
failed to find a significant effect (P=0.05) of lumbar back support tension on
the average normalized EMG across the 10 trunk muscles sampled. CONCLUSIONS: For
static experimental tasks, as long as electrodes are protected from direct
contact with the back support, studies assessing the effect of lumbar back
supports on the trunk muscles via EMG during static tasks are not subject to
confounding due to differences in tensions across subjects. RelevanceThe results
of this study suggest that variable tensions from previous studies for static
exertions with lumbar back supports do not significantly alter the pick-up volume
of protected electrodes.
PMID- 10675672
TI - Spinal load changes during rotatory dynamic sitting.
AB - OBJECTIVE: To measure load and moment changes acting on the lumbar spine during
rotatory sitting. BACKGROUND: A new chair concept generating dynamic stimuli by
alternating rotations in the horizontal plane of the chair's seat was recently
developed. METHODS: Load and moment changes were measured telemetrically with a
spinal fixator device in vivo. RESULTS: A rotatory frequency of 0.22 Hz with an
amplitude of 1.8 degrees to the right and left side showed maximum axial force
changes in the fixator of 23 N and maximum bending moment changes of 0.52 Nm.
CONCLUSIONS: Lumbar force and moment changes during dynamic sitting occur,
although only one patient was included in the study. Reasons could be temporary
muscular activation in order to adapt the body's equilibrium conditions at the
end-point rotation. RelevanceOur measurements suggest that a rotatory chair does
have an effect on lumbar spine forces. It becomes more likely that this concept
could improve the discs' nutrition and may prevent low back pain.
PMID- 10675673
TI - Development of a clinical instrument to measure heel pad indentation.
AB - OBJECTIVE: To provide an accurate, reliable, non-invasive, portable instrument to
measure heel pad indentation in a clinical setting. DESIGN: A novel instrument
was applied to assess heel pad indentation. BACKGROUND: For the lack of
quantitative biomechanical tools for in vivo assessment, palpation is used to
evaluate heel pad stiffness subjectively in everyday clinical practice.
Furthermore, previous studies have evaluated heel pad stiffness using non
portable instrumentation. METHODS: Cylindrical probe was attached to an
electronic force gauge unit that passed through a Perspex plate for placement on
heel pad. Displacement of the plate was connected to a linear variable
differential transformer. A laptop PC allowed for portability and storage of
data. An exponential curve described the force-displacement data. Ten healthy
subjects (mean 21. 7; SD, 1.7 years) were assessed on ten separate occasions. The
procedure was standardised for subject position and placement. RESULTS: Accuracy
and reliability of each device component was established. An intraclass
correlation (2,1) of 0.90 and 0.88 demonstrated curve coefficients b1 and b0
respectively. A paired t-test demonstrated no significant difference between the
left and right foot coefficients. CONCLUSION: The results demonstrated that each
system component could be measured accurately and reliable. Reproducible results
were obtained over separate occasions. The study has described a method to
analyse the force-displacement curve. RelevanceThe development of a hand-held
device may help the clinician to assess heel pad stiffness in the clinical
setting. Heel pad stiffness may be associated in the development of plantar heel
pain in athletes.
PMID- 10675674
TI - Comparison of surface modification and solid dispersion techniques for drug
dissolution.
AB - Surface modification and solid dispersion formulations using hydrophilic
excipients can significantly alter the dissolution behaviour of hydrophobic drug
materials. The effect of these techniques used individually and in combination on
the dissolution properties of the hydrophobic drug, phenylbutazone (PB), are
compared. PB was treated with a poloxamer, Synperonic((R)) F127 by an adsorption
method. Solid dispersions (10 and 20% w/w) were prepared with untreated PB or PB
previously modified with Synperonic((R)) F127 (PBT) in molten F127. Dissolution
tests of capsule formulations of PB, PBT and solid dispersion formulations, in pH
6.4 buffer at 37+/-0.5 degrees C demonstrated that after 140 min, release of PB
was 16.7%, but 71.4% from the solid dispersion, whereas from the PBT formulation
85.6% was released. The Synperonic((R)) F127 content of PBT was only 0.05% of
that in the solid dispersion formulation which suggests that it is the nature of
the drug polymer contact rather than the amount of polymer which is more critical
in influencing dissolution behaviour. Comparison of PBT and the 10% w/w solid
dispersion of PBT in F127 showed similar amounts of drug in solution after 140
min. However there was a significantly higher release rate for PBT. Both
formulation techniques offer significant improvements in drug release over
untreated PB, and a combination of techniques changes the rate but not the extent
of release in comparison with the surface modification technique alone.
PMID- 10675675
TI - Effect of contamination of pharmaceutical equipment on powder
triboelectrification.
AB - Triboelectrification of pharmaceutical powders may cause problems during
processing and manufacture due to adhesion/cohesion effects. The aim of this work
was to investigate the role of adhered particles and moisture as contact surface
contaminants on the electrostatic charging of size fractionated lactose,
following contact with a surface, i.e. stainless steel, typically used in
pharmaceutical process and manufacturing operations. Replicated experimental runs
without cleaning the contact surface showed a successive decrease in the net
electronegative charge due to adhered lactose particles. Removal of these
contaminating particles by different cleaning methods had a considerable effect
on the charge after triboelectrification. The charge on the lactose samples was
found to decrease when humidity in the cyclone apparatus was increased from 2 to
100% relative humidity. These results clearly demonstrate that moisture,
particulate contamination and method of cleaning of processing equipment during
pharmaceutical manufacturing operations may influence the electrostatic behaviour
of powders.
PMID- 10675676
TI - Prodrug to probe solution HFA pMDI formulation and pulmonary esterase activity.
AB - A novel salbutamol prodrug was synthesised. Solubility in HFA-134a and
susceptibility to rat lung homogenate, blood and plasma esterase enzymes were
investigated. Whereas salbutamol had a very low solubility in HFA-134a, the
prodrug was found to be miscible in all proportions. In lung homogenate, the
prodrug hydrolysed with a half-life of 45 min, re-generating approximately 17% of
expected salbutamol after 8 h incubation. The use of a solution pMDI for
pulmonary delivery of the salbutamol prodrug is predicted to result in liberation
of salbutamol in the lungs following in vivo hydrolysis by lung esterases.
PMID- 10675677
TI - Microcalorimetry does not predict the cellular phagocytosis of latex
microspheres.
AB - Current literature highlights the potential suitability of microcalorimetry for
the investigation of cell-drug interactions. Previous work using bacteria or
antigens derived from infectious organisms yielded conclusions that heat
production is a quantitative means of measuring phagocytosis. In this study we
evaluated the potential of flow-through microcalorimetry as a method of
quantifying the phagocytosis of microsphere particulates. The technique avoids
the need to incorporate radioactive or fluorescent markers into the particulate
formulation, and would be widely applicable in biopharmaceutical research. Using
the monocyte cell line Mono Mac 6 a power output of 9.00 microW per million cells
was increased significantly on addition of zymosan, lipopolysaccaride (LPS) and
phorbol myristate acetate but not following exposure to FITC labelled latex
microspheres (LM). TNFalpha production increased on exposure to zymosan, LPS and
LPS-phorbol myristate acetate, though not on exposure to LB. An assay was
developed which allowed the quantification of internalised particulates in
phagocytic cells using fluorescent activated cell sorting (FACS). In contrast to
the microcalorimetric and TNFalpha data FACS revealed that 20% of the MM6
population phagocytosed a mean of 1.35 LM. Microcalorimetry and measurements of
TNFalpha production are assays of cellular activation a phenomenon not
necessarily associated with phagocytosis. FACS, however, serves as a specific and
quantitative measure of phagocytosis. Microcalorimetry may not be a suitable
technique for the quantitative assessment of the phagocytosis of drug delivery
particulates.
PMID- 10675678
TI - Characterisation of fatty acid multilayers using a TSM biosensor.
AB - Thickness shear mode (TSM) biosensors have many potential applications within the
pharmaceutical sciences as a means of measuring mass changes in the nanogram
range, film thickness, viscosity and shear moduli. This study addresses the
possible use of the TSM sensor as a biosensor for measuring drug partition
coefficients. In order to realise this potential, some fundamental understanding
is required of the behaviour of lipid films on the sensor. The present study
characterises the behaviour of fatty acid multilayers as a suitable model
chemical system. Frequency shifts and impedance spectra are presented for
multilayers of three fatty acid films coated on to the sensor using a Langmuir
Blodgett trough. The results indicate that the frequency shift is non-linear at
lower numbers of fatty acid layers but the response is Sauerbrey-like at higher
numbers of layers. Also at high numbers of layers, changes in the impedance
spectra indicate viscoelastic behaviour in thicker membranes. An inverse
relationship is observed between chain length and frequency shift, which is
attributed to variations in the topography of the sensor surface. This work
demonstrates the importance of fully characterising the physical behaviour of the
lipid multilayers prior to using these systems for the measurement of drug
partition coefficients.
PMID- 10675679
TI - In vitro peptide release from liquid crystalline buccal delivery systems.
AB - Swelling and [D-Ala(2), D-Leu(5)]enkephalin (DADLE) release from the lamellar and
cubic liquid crystalline phases of glyceryl monooleate (GMO) were studied using
two in vitro methods, a total immersion method and a Franz cell method. The
swelling of the lamellar phase and glyceryl monooleate (0% w/w water content) and
DADLE release from the liquid crystalline phases were temperature dependent. The
swelling ratio was greater at 20 degrees C than 37 degrees C while DADLE release
increased at 37 degrees C compared to 20 degrees C for both the lamellar and
cubic phases. The water uptake increased dramatically with decreasing initial
water content of the liquid crystalline phases. However, DADLE release increased
with increasing initial water content, which corresponded to increased viscosity.
The swelling and DADLE release profiles obtained using a Franz cell method with a
moist nylon membrane to mimic buccal drug release conditions were slower than the
total immersion method. These results show that the swelling and DADLE release
strongly depended on temperature, the initial water content of the liquid
crystalline matrix and the methodology employed for determining the swelling and
DADLE release.
PMID- 10675680
TI - Buccal permeation of [D-Ala(2), D-Leu(5)]enkephalin from liquid crystalline
phases of glyceryl monooleate.
AB - The ex vivo buccal permeability of a [D-Ala(2), D-Leu(5)]enkephalin (DADLE) and
glyceryl monooleate (GMO) was examined from the cubic and lamellar liquid
crystalline phases of GMO and aqueous phosphate-buffered saline (pH 7.4, PBS)
solution across excised porcine buccal mucosa mounted in a Franz cell. GMO was
released in vitro from the liquid crystalline phases indicating the erosion of
the liquid crystal matrices. GMO released from the liquid crystalline matrices
permeated the porcine buccal mucosa with fluxes of 0.10+/-0.03 and 0.07+/
0.00%/cm(2) per h for the cubic and lamellar phases, respectively. The flux of
DADLE (1.21+/-0.32 and 1. 15+/-0.11%/cm(2) per h for the cubic and lamellar
phases, respectively) from the liquid crystalline phases was significantly
enhanced by the GMO compared with PBS solution (0.43+/-0.08%/cm(2) per h) during
the initial permeation phase (t<3 h). Our results suggest that the cubic and
lamellar liquid crystalline phases can be considered as promising buccal drug
carriers for peptide drugs as well as acting as permeation enhancers.
PMID- 10675681
TI - Pharmaceutical applications for molecularly imprinted polymers.
AB - Molecular imprinting is a means of introducing sites of specific molecular
arrangement into an otherwise uniform polymeric matrix. This is achieved by
formation of a pre-polymerisation complex between complementary monomers and the
template molecule. Subsequent polymerisation in the presence of a crosslinker, in
a porogenic environment, results in the production of a macroporous polymer
capable of specific molecular recognition. This paper considers potential roles
for molecularly imprinted polymers within a pharmaceutical remit. Applications
including controlled release, drug monitoring devices and biological receptor
mimetics are discussed. Histamine and ephedrine molecularly imprinted polymers
(MIPs) were studied as potential biological receptor mimics whilst a propranolol
MIP was investigated for its use as a rate attenuating selective excipient in a
transdermal controlled release device. Preliminary studies concerning the
preparation of a theophylline selective transcutaneous monitoring device, using a
theophylline MIP, are also described.
PMID- 10675682
TI - Preparation and characterization of Furosemide-Eudragit controlled release
systems.
AB - Solid dispersions and physical mixtures were prepared and characterized by X-ray
diffraction, infrared spectroscopy, electronic microscopy and dissolution rate
studies. The characterization with X-ray diffraction showed a transition from the
crystalline to the amorphous phase. A new phase near 50% Furosemide concentration
with both types of carriers was present. From infrared spectroscopy strong
interactions between amine and carbonyl groups from both the Furosemide and the
polymers were found. Electronic microscopy analysis showed that the Furosemide
changed its crystalline habit from needle to a new spherical phase, with diameter
near to 1 microm. Solid dispersions were prepared in order to modify the system
characteristics. The Furosemide dissolution rate was determined in order to
follow the behavioural changes of the system. Scanning electron microscopy showed
the presence of micro spheres within the polymeric matrix, and the channels
formed due to the Furosemide dissolution inside the Eudragit: this fact modified
the release pattern of the Furosemide system.
PMID- 10675683
TI - In vitro percutaneous penetration of topically applied capsaicin in relation to
in vivo sensation responses.
AB - Capsaicin, the primary pungent element in several spices, elicits a variety of
physiological effects which are due to neurogenic responses. The aim of the study
was to explore the in vivo sensation responses of capsaicin and to compare the
results with the in vitro percutaneous absorption of the substance. The overall
objectives were to determining an in vitro-in vivo correlation for capsaicin.
Capsaicin was applied in a chamber on the volar forearm of twelve volunteers and
in a flow-through diffusion chamber on excised human epidermal membranes. Topical
administration of capsaicin produced a complex cutaneous sensation that changed
in intensity and quality as a function of time and was characterized by sting,
prick, burn and pain. Percutaneous steady-state penetrations of capsaicin with a
receptor fluid consisting either of 4% bovine serum albumin in phosphate buffered
saline or 50% ethanol in water were 28.2+/-2.7 and 29.6+/-2.9 microg/cm(2) per h,
respectively. The corresponding cumulative penetrated amounts of capsaicin after
30 min were 14. 7+/-1.7 and 19.2+/-2.1 microg/cm(2), respectively. The present
investigation indicates that there is a good correlation between in vivo
physiological responses and in vitro percutaneous penetration of topically
applied capsaicin.
PMID- 10675684
TI - Does the site of intestinal delivery of oleic acid alter the ileal brake
response?
AB - Previous work has demonstrated that high doses of oleic acid can activate the
ileal brake but the importance of site of delivery has yet to be investigated.
The objective of this study was to use modified release capsules to release oleic
acid in different regions of the intestine. When tested by in vitro dissolution
in pH 6.8 phosphate buffer, one batch released the contents almost immediately,
another after around 30 min and the last batch after around 60-70 min. The effect
of oleic acid release site on the ileal brake was assessed by the measurement of
transit time of radiolabelled non disintegrating tablets by gamma scintigraphy.
The results demonstrated that the transit of tablets could be slowed down by
oleic acid and therefore it appears the ileal brake can be activated along the
entirety of the small intestine.
PMID- 10675685
TI - Interaction of p-hydroxybenzoic esters with beta-cyclodextrin.
AB - In the present investigation, the complex formation of beta-cyclodextrin (betaCD)
with p-hydroxybenzoic esters (parabens) was studied by mixing betaCD with methyl,
ethyl, propyl and butyl parabens, respectively, in aqueous solutions and
subjecting the resultant mixtures individually to the following processes:
occasional shaking for 24 h at 25 degrees C, continuous shaking using shaker bath
for 24 h at 25 degrees C, intermittent ultrasonification for 90 min at 25 degrees
C, autoclaving at 115 degrees C for 30 min and freeze-drying followed by
reconstitution with distilled water. The degrees of interaction between betaCD
and the parabens subjected to the various processes were evaluated, using the
membrane dialysis method. The difference in the method of processing did not
affect the degree of interaction significantly. However, the degree of
interaction was found to increase proportionally with the concentration of
betaCD. The alkyl group of the parabens was also found to affect the extent of
interaction. Compared to methyl paraben, the degree of interaction of ethyl
paraben was observed to be lower. Interestingly, further increase in the size of
the alkyl group significantly enhanced the extent of interaction. Studies using
1H-NMR showed that the extent of interaction depended on how well the parabens
could fit into the betaCD cavity.
PMID- 10675686
TI - Prediction of suitable amount of water addition for wet granulation.
AB - The purpose of this study was to predict the amounts of water addition suitable
for pharmaceutical formulations in wet granulation, using a high-speed mixer or a
fluidized bed granulator, before granulation trials. In order to determine the
suitable amount of water addition, each excipient was first subjected to kneading
with water in a mortar and a refractive near-infrared moisture sensor (IR sensor)
measured the amount of water at the powder surface. Further by analysis the plot
(output value of the IR sensor vs. amount of added water) for each excipient, the
amount of water addition for granulation was determined for it. As a second step,
two model formulations were designed and suitable amounts of water for
granulation were predicted by summation of the obtained excipient values. The
predicted value was compared with the experimental value for high-speed mixer
granulation. The predicted and experimental amounts of water addition
corresponded for the two model formulations, suggesting that the above method is
useful for estimating suitable amounts of addition of water for formulations
before granulation trials.
PMID- 10675687
TI - Characterization of proteolytic activities of pulmonary alveolar epithelium.
AB - Pulmonary alveolar type I epithelial cell and its progenitor, type II cell,
present major transport and enzyme barriers for systemic delivery of pulmonary
administered peptide drugs. The present study investigates the effect of cellular
differentiation of type II to type I cells on their proteolytic activities, and
evaluates the suitability of a continuous lung cell line, A549, for drug
transport and degradation studies. High performance liquid chromatography was
used to assess the degradation kinetics of two model peptide substrates,
luteinizing hormone releasing hormone (LHRH) and [D-Ala(6)10-fold decrease in
proteolytic activities for LHRH, as compared to type II cells. The continuous
lung cell line A549 formed leaky monolayers and exhibited similar enzyme
activities to the primary type II cells. The responsible enzymes for degradation
of LHRH in type II and A549 cells were angiotensin converting enzyme (ACE),
EP24.11, and EP24.15. In contrast, no EP24.15 or ACE activity was observed in
type I-like pneumocytes and only a weak EP24.11 activity was detected. In all
cell types, the degradation rate of [D-Ala(6)]-LHRH was about 3-8 times lower
than that of LHRH. This peptide analog was resistant to degradation by EP24.15
and EP24.11, but was susceptible to ACE-mediated cleavage.
PMID- 10675688
TI - Ethyl formate - alternative dispersed solvent useful in preparing PLGA
microspheres.
AB - In an effort to substitute methylene chloride with a less toxic solvent, this
study was aimed at developing new ethyl formate-based emulsion processes to
fabricate poly-D,L-lactide-co-glycolide (PLGA) microspheres. To do so, a
polymeric dispersed phase was emulsified in a 1% polyvinyl alcohol aqueous
solution at an ethyl formate to aqueous volume ratio of 8:20. Microsphere
hardening was then achieved by solvent evaporation and quenching techniques. The
average encapsulation efficiency of a model drug progesterone amounted to 95.2+/
2.7%. When the tendency of ethyl formate and methylene chloride to evaporate to
air was compared, the evaporation rate of ethyl formate was 2.1 times faster than
that of methylene chloride. The ease with which ethyl formate evaporated to air
was beneficial in shortening the microsphere hardening step. For the solvent
quenching process, only 80 ml of additional water was required to extract ethyl
formate to the aqueous phase, due to its considerable water miscibility. In
particular, the timing of ethyl formate quenching affected to a great extent
dynamic processes of the breakup of elementary microdroplets into smaller ones.
Therefore, variations in quenching time affected microsphere characteristics such
as the degree of solvation, size distribution, and tendency to aggregate on
drying. The results of this study showed that PLGA microspheres were successfully
prepared using the new ethyl formate-based processes.
PMID- 10675689
TI - Carrier-mediated transport of valproic acid in BeWo cells, a human trophoblast
cell line.
AB - The biochemical mechanisms mediating the rapid distribution of valproic acid
across placenta are not precisely known. We have characterized valproic acid
transport by the human trophoblast using the human choriocarcinoma cell line,
BeWo. The uptake of [14C]valproic acid by BeWo cells was found to be saturable
and blocked by pre-exposure to the metabolic inhibitors, sodium azide and 2,4
dinitrophenol. Valproic acid uptake by the BeWo cells was also inhibited by the
protonophore, carbonylcyanide p-trifluoromethoxyphenylhydrazone, but not anion
exchange inhibitor. Selected monocarboxylic acids inhibited the uptake of
[14C]valproic acid by BeWo cells, whereas dicarboxylic acids did not alter the
uptake process. Analysis of Lineweaver-Burk plots of valproic acid uptake in the
presence of benzoic acid, a marker for the monocarboxylic acid transporter,
revealed a competitive process for uptake. In transcellular transport
experiments, the permeation of [14C]valproic acid from the apical-to-basal side
of the monolayers was significantly greater than the permeation from basal-to
apical side. Additionally, the permeation of [14C]valproic acid from apical-to
basal side was inhibited by monocarboxylic acids and not dicarboxylic acids. The
results provide biochemical evidence of a proton-dependent, saturable, and
asymmetric transport system, presumed to be a monocarboxylic acid transporter,
for valproic acid in a human trophoblast model.
PMID- 10675690
TI - Optimisation of floating matrix tablets and evaluation of their gastric residence
time.
AB - The present investigation concerns the development of the floating matrix
tablets, which after oral administration are designed to prolong the gastric
residence time, increase the drug bioavailability and diminish the side effects
of irritating drugs. The importance of the composition optimisation, the
technological process development for the preparation of the floating tablets
with a high dose of freely soluble drug and characterisation of those tablets
(crushing force, floating properties in vitro and in vivo, drug release) was
examined. Tablets containing hydroxypropyl methylcellulose (HPMC), drug and
different additives were compressed. The investigation shows that tablet
composition and mechanical strength have the greatest influence on the floating
properties and drug release. With the incorporation of a gas-generating agent
together with microcrystalline cellulose, besides optimum floating (floating lag
time, 30 s; duration of floating, >8 h), the drug content was also increased. The
drug release from those tablets was sufficiently sustained (more than 8 h) and
non-Fickian transport of the drug from tablets was confirmed. Radiological
evidence suggests that, that the formulated tablets did not adhere to the stomach
mucus and that the mean gastric residence time was prolonged (>4 h).
PMID- 10675691
TI - An investigation into the release of cefuroxime axetil from taste-masked stearic
acid microspheres. II. The effects of buffer composition on drug release.
AB - The influence of buffer composition on the release of cefuroxime axetil from
stearic acid microspheres has been investigated, with particular emphasis on
establishing the relationship between buffer composition and release at a single
pH value. Studies of drug dissolution and release from spheres in pH 7.0 citrate
phosphate buffer (CPB), boric acid buffer (BAB), phosphate buffer mixed (PBM) and
Sorensens modified phosphate buffer (SMPB) indicated marked differences in
release profile from the spheres, with an approximate rank order of SMPB > CPB
approximately BAB > PBM. The role of added sodium was then investigated by
examining the release profiles in SMPB and PBM to which sodium ions had been
added. Increases in the sodium content from approximately 0.11 to 0.2 M were
found to decrease the release rate for the SMPB, while increases from 0.007 to
1.0 M sodium in PBM resulted in a maximum release being seen for the systems
containing 0.05 M sodium. Studies on surface disintegration, using scanning
electron microscopy (SEM) and sodium uptake using flame emission spectroscopy,
indicated an interrelationship between medium composition, disintegration and
release. The data are discussed in terms of the possible mechanisms associated
with drug release from these spheres.
PMID- 10675692
TI - Anti-mucus polyclonal antibody production, purification and linkage to the
surface of albumin microspheres.
AB - This aim of this study was to develop a microparticulate based oral drug delivery
system, which could prolong gut transit time by binding via specific interactions
to the gut mucus layer. Porcine gastric mucus was semi-purified and used as an
antigen to raise a polyclonal antiserum in rabbits. The immunoglobulin fraction
of this serum was isolated, purified and tested for homogeneity and cross
reactivity. High cross-reactivity was displayed when the antiserum was challenged
against types of mucus other than that used as an antigen, but no significant
cross-reactivity occurred when challenged against some other common
macromolecules. The antibody fraction of this serum was covalently linked to
three types of albumin microspheres (MS) using 1-ethyl-3(3-dimethyl aminopropyl)
carbodiimide. The MS employed had either a hydrophobic, a hydrophilic or a
carboxymethylated surface, and were prepared and characterised as described
earlier (MacAdam, A.B., Shafi, Z.B., Martin, G.P. and James, S.L. 1997.
Preparation of hydrophobic and hydrophilic MS and determination of surface
carboxylic acid and amino residues. Int. J. Pharm. 151, 47-55). Binding of these
MS to both radioiodinated mucin in suspension and to isolated gut segments was
measured. Hydrophilic and carboxymethylated MS with surface-associated antibody
bound significantly more mucin from a suspension than did uncoated controls.
Similarly, anti-mucus antibody-coated hydrophilic and carboxymethylated MS bound
more strongly to an isolated gut segment than did uncoated controls or controls
coated in an antibody specific for albumin. These results suggest anti-mucus
antibody coated albumin MS may be a useful model to act as comparators in studies
aimed at developing drug delivery systems with delayed gastrointestinal transit.
PMID- 10675693
TI - Artefact formation in the determination of residual solvents according to a
method of the European Pharmacopeia.
AB - Method 2 of the procedure for the identification and assay of residual solvents,
of the European Pharmacopeia 3rd edition 1999 addendum, leads to artefactual
formation of N-chlorodimethylamine when the hydrochlorides of basic compounds are
examined. This is due to degradation of the dissolution solvent N,N
dimethylformamide under the prescribed conditions. N-Chlorodimethylamine has been
detected during analysis of several hydrochloride salts of nitrogen bases
including drug substances. Artefact formation did not occur consistently with all
the compounds examined, but with diltiazem hydrochloride it was observed in the
majority of experiments. The discovery that the alkylating reagent N,N
dimethylaminoethyl chloride (DMC) used in the synthesis of diltiazem gives
apparently high yields of N-chlorodimethylamine was cause for concern. However,
it has been confirmed that production batches of diltiazem hydrochloride contain
<1 ppm of this synthetic intermediate. The formation of N-chlorodimethylamine in
the presence of the drug substance is probably due to a reaction between
dimethylformamide and HCl, that would be released as a result of hydrolysis by
residual water of the O-acetyl function of diltiazem. In view of these findings,
the compendial general method should be reviewed. It may be necessary to adopt a
different approach to the drafting of methods for volatile impurities, since most
of the operating conditions are in practice specific to the substance being
examined.
PMID- 10675694
TI - In vitro permeation through porcine buccal mucosa of Salvia desoleana Atzei &
Picci essential oil from topical formulations.
AB - In the light of recent studies, which have shown that the essential oil derived
from some Lamiaceae species has appreciable anti-inflammatory activity, moderate
anti-microbial action and the ability to inhibit induced hyperalgesia, an
assessment of the diffusion and permeation of Salvia desoleana Atzei & Picci (S.
desoleana) essential oil through porcine buccal mucosa was considered useful for
a possible application in the stomatological field. Topical formulations
(microemulsions, hydrogels and microemulsion-hydrogels) were prepared for
application to the buccal mucosa. The mucosa permeation of the oil from the
formulations was evaluated using Franz cells, with porcine buccal mucosa as
septum between the formulations (donor compartment) and the receptor phase
chambers. The study also aimed at optimising the permeability of the S. desoleana
essential oil by means of an enhancer, the diethylene glycol monoethyl ether
Transcutol. The diffusion of the oil through the membrane was determined by
evaluating the amount of essential oil components present in the receiving
solution, the flux and the permeation coefficient (at the steady state) in the
different formulations at set intervals. Qualitative and quantitative
determinations were done by gas chromatographic analysis. All the formulations
allow a high permeability coefficient in comparison with the pure essential oil.
In particular, the components with a terpenic structure (beta-pinene, cineole,
alpha-terpineol and linalool) have the highest capacity to pass through the
porcine buccal mucosa when compared to the other components (linalyl acetate and
alpha-terpinil acetate). Moreover, the enhancer, diethylene glycol monoethyl
ether largely increases the permeation of the essential oil components in
relation to the concentration.
PMID- 10675695
TI - Diclofenac sodium incorporated PLGA (50:50) microspheres: formulation
considerations and in vitro/in vivo evaluation.
AB - Recently, considerable interest has been focused on the use of biodegradable
polymers for specialized applications such as controlled release of drug
formulations; meanwhile, microsphere drug-delivery systems using various kinds of
biodegradable polymers have been studied extensively during the past two decades.
Poly (lactide-co-glycolide) (PLGA) polymers have been proven to be excellent drug
carriers for microparticulate systems due to their advantages, e.g.
biocompatibility and regulatory approval. The administration of nonsteroidal anti
inflammatory drugs (NSAIDs) into the intra-articular cavity in patients with
chronic inflammatory disease is complicated due to the short duration of effect.
In the present study, controlled-release parenteral formulations of diclofenac
sodium (DS), a commonly used NSAID, were prepared for intra-articular
administration, and evaluated in vitro for particle size, yield, drug loading,
surface morphology and release characteristics. For in vivo studies, Technetium
99m labelled polyclonal human immunogammaglobulin (99m Tc-HIG) was used as the
radiopharmaceutical to demonstrate arthritic lesions by gamma scintigraphy.
Evaluation of arthritic lesions post-therapy in rabbits showed no significant
difference in the group treated with PLGA (50:50) (mw 34000) DS microspheres
compared to control groups.
PMID- 10675696
TI - Unexpected skin barrier influence from nonionic emulsifiers.
AB - Skin disorders are often treated with creams containing various active
substances. The creams also contain emulsifiers, which are surface-active
ingredients used to stabilize the emulsion. Emulsifiers are potential irritants
and in the present study the influence of stearic acid, glyceryl stearate, PEG-2,
-9, -40, and -100 stearate, steareth-2, -10 and -21 on normal as well as on
irritated skin have been evaluated with non-invasive measurements. Test emulsions
were created by incorporating 5% emulsifiers in a water/mineral oil mixture
(50:50). The emulsions and their vehicle were then applied to normal skin for 48
h and to sodium lauryl sulfate (SLS) damaged skin for 17 h in aluminum chambers.
Twenty-four hours after removal of the chambers the test sites were evaluated for
degree of irritation. In normal skin, the emulsifiers induced significant
differences in TEWL but not in skin blood flow. Five of the emulsifiers increased
TEWL. In SLS-damaged skin an aggravation of the irritation was expected. However,
no differences regarding skin blood flow was noted from the emulsifiers.
Furthermore, three emulsifiers unexpectedly decreased TEWL. These results
highlight the possibility of absorption of these emulsifiers into the lipid
bilayer, which increase TEWL in normal skin and decrease TEWL in damaged skin.
PMID- 10675697
TI - Nasal absorption of (S)-UH-301 and its transport into the cerebrospinal fluid of
rats.
AB - Targeting the brain via nasal administration of drugs has been studied frequently
over the last few years. In this study, the serotonin-1a receptor antagonist (S)
5-fluoro-8-hydroxy-2-(dipropyl-amino) tetralin ((S)-UH-301) hydrochloride was
used as a model substance. The systemic absorption and transport of (S)-UH-301
into male Sprague-Dawley rat cerebrospinal fluid (CSF) were investigated after
nasal and intravenous administration. Blood and CSF samples were obtained at
regular time intervals from the arteria carotis and by cisternal puncture,
respectively, after administration to both nostrils (total 12 micromol/kg) or
into the vena jugularis (6 micromol/kg). The concentrations of (S)-UH-301 in
plasma and CSF were measured by HPLC with electrochemical detection. The maximum
plasma concentration of intranasal (S)-UH-301 occurred in about 7 min and the
absolute bioavailability seemed to be complete (F=1.2+/-0.4). Initially, no
increased concentrations of (S)-UH-301 were seen in CSF after nasal compared to
intravenous administration i.e. it appeared that no direct transport of (S)-UH
301 from the nasal cavity, along the olfactory neurons and into the CSF occurred.
However, a prolonged duration of the concentration was seen after nasal
administration of (S)-UH-301 and after about 20 min the CSF(na):CSF(iv)
concentration ratio (corrected for different dosage) exceeded 1.
PMID- 10675698
TI - The interaction of human serum albumin and model membranes.
AB - It is frequently observed that the interaction of human serum albumin (HSA) with
different lipid membranes may affect molecular transport both in vivo and in
vitro experiments. There was a lack of consensus however in the interpretation of
results. Earlier studies on the serum albumin membrane association had different
conclusions depending on the source of protein, the preparation and the
composition of the membranes applied. In this work the change of heat capacity, a
sensitive parameter of the interacting system, is compared for uni- and
multilamellar liposomes (dimyristoyl-phosphatidylcoline/dimyristoyl
phosphatidylglycerol) at 0, 1x10(-3), 8x10(-3), 1.2x10(-2) and 3.3x10(-2) HSA
lipid ratios. The thermal properties of the sonicated and vortexed liposomes show
remarkable differences. The presence of HSA in both types of liposomes also
modified their thermal properties, providing clear evidence for protein-vesicle
interaction, different in the uni- and multilamellar liposomes. In the case of
unilamellar liposomes, two additional transitions were observed at lower
temperature, independently of the HSA-lipid ratio, and the protein binding mode
to smaller or larger sized liposomes was also distinguishable. The addition of
HSA to the multilamellar liposomes resulted in an increase of the pretransition
temperature only at the higher HSA-lipid ratio, but the main transition
temperature was not affected.
PMID- 10675699
TI - Silica xerogel carrier material for controlled release of toremifene citrate.
AB - Sol-gel processed silica xerogel was used as a carrier material for toremifene
citrate in order to develop an implantable controlled release formulation which
could be localised to a desired site providing targeted and long-lasting disease
control and resulting in a reduced amount of drug needed. Toremifene citrate, an
anti-estrogenic compound, was incorporated into silica xerogel matrixes during
polycondensation of organic silicate, tetraethyl ortho silicate (TEOS). The
effects of drug amount, drying temperature and polyethylene glycol (PEG) on the
release rate of toremifene citrate and degradation of the silica xerogel matrixes
were investigated. Addition of PEG (M(w) 4600/10000) decreased the specific
surface area of the matrix and lowered the release rate of the drug. Reducing the
amount of drug in the matrix also decreased the release rate of toremifene
citrate. However, drying temperature did not affect the release rate of silica or
toremifene citrate. The release profiles of toremifene citrate were according to
zero order kinetics, suggesting that drug release was controlled by erosion of
the silica xerogel matrix. These results suggest that the toremifene citrate
release rate can be controlled to some extent by adding (PEG) or by varying the
amount of drug in the silica xerogel matrix.
PMID- 10675700
TI - High molecular weight polyethylene oxides (PEOs) as an alternative to HPMC in
controlled release dosage forms.
AB - High molecular weight polyethylene oxides (PEOs) have recently been proposed as
an alternative to hydroxypropylmethylcellulose (HPMC) in controlled release
matrix tablets. In this study, we compared the performance of PEO and HPMC
polymers when employed in the Geomatrix technology, a versatile, well-known
method to achieve extended release of drugs at a constant rate. Four core
formulations were prepared, containing a soluble drug (diltiazem) and,
alternatively, PEO or HPMC of two different viscosity grades. These formulations
have the same composition except for the polymer employed. Similarly, four
barrier formulations were also prepared, which only differ in the kind of polymer
employed. Three-layer Geomatrix systems were then prepared using these core and
barrier formulations. The release profiles of the different three-layer systems
obtained were compared, to verify if PEO could efficiently replace HPMC in this
type of dosage form. The results show that slower release rates can be obtained
from the plain matrices containing HPMC compared to PEO, moreover HPMC, used in
the barrier formulations, is generally more efficient in controlling drug release
rate in three-layer Geomatrix systems.
PMID- 10675701
TI - Preparation and characterisation of a new insoluble polymorphic form of
glibenclamide.
AB - A crystalline form of glibenclamide, with higher melting point (218 degrees C)
and lower solubility in simulated gastric and intestinal fluids, was arisen
during an attempt to elucidate transitional phases by melting, cooling and
reheating. The new form was obtained from the glassy state, by applying
sublimation at 130-160 degrees C and was characterised by differential scanning
calorimetry (DSC), infrared (IR) spectroscopy, scanning electron microscopy
(SEM), hot-stage microscopy (HSM), X-ray powder diffraction (XRD) and solubility
studies. Formation of the new crystal form is considered as reason of reduction
in dissolution and bioavailability of tablets.
PMID- 10675702
TI - Surface drug removal from ibuprofen-loaded PLA microspheres.
AB - The preparation, characterisation and drug release behaviour of ibuprofen loaded
poly(D,L-lactic acid) (PLA) microspheres are described. Depending on the gelatin
concentration in the aqueous external solution (1, 0.5, 0.1% w/v), microspheres
with three different sizes (2.2, 4.1, 7.5 micrometer) were obtained. The
properties of microspheres washed with water (Untreated microspheres) (Un-Ms)
were compared to those of the microspheres washed with a sodium carbonate
solution in order to remove the surface drug (treated microspheres) (T-Ms). The
results indicate that the removal of the surface drug did not induce any change
in the size of the microspheres whereas the morphology of the smallest T-Ms
appeared to be modified. The release profiles of both Un-Ms and T-Ms resulted in
biphasic patterns. The initial burst effect (first release phase) of the T-Ms was
lower than that of the Un-Ms. The rate of the second release phase did not change
for the microspheres with the biggest size but increased for the smallest
microspheres probably owing to the modification of the matrix porosity.
PMID- 10675703
TI - Is bisacodyl absorbed at all from suppositories in man?
AB - A HPLC procedure was developed to determine free BHPM in human plasma and urine
after prior deconjugation of its glucuronides with glucuronidase. A single dose
administration of a 10 mg bisacodyl suppository from Glaxo Wellcome, Poznan
(Poland) to 16 volunteers each resulted in its low active metabolite (BHPM)
plasma levels (10-55 microgram l(-1)) according to general assumptions. Its
prompt laxative effect appeared within 56.6+/-10.8 min. The calculated serum half
life time of BHPM glucuronide excretion in urine was approximately 7.32+/-0.99 h.
BHPM was excreted in urine in only 3. 36+/-0.52% if compared with the above
bisacodyl rectal dose administered. Any relationship between BHPM plasma and/or
urine levels and its laxative action does not occur. These results confirm the
thesis that the laxative action of bisacodyl suppositories is initiated through a
direct interaction of the drug in the rectum.
PMID- 10675704
TI - Kinetics of base catalyzed racemization of ibuprofen enantiomers.
AB - The kinetics of base catalyzed racemization of ibuprofen enantiomers has been
studied in DMSO-water mixed medium. The dynamic equilibrium rate of keto-enol
tautomerism leading to racemization of ibuprofen enantiomers, is proportional to
the concentrations of base catalyst and substrate. A kinetic model capable of
predicting the time course of racemization, under different base and substrate
concentrations, is established and experimentally verified.
PMID- 10675705
TI - Preformulation studies and characterization of the physicochemical properties of
amorphous polymers using artificial neural networks.
AB - The utility of artificial neural networks (ANNs) as a preformulation tool to
determine the physicochemical properties of amorphous polymers such as the
hydration characteristics, glass transition temperatures and rheological
properties was investigated. The neural network simulator, CAD/Chem, based on the
delta back-propagation paradigm was used for this study. The ANNs software was
trained with sets of experimental data consisting of different polymer blends
with known water-uptake profiles, glass transition temperatures and viscosity
values. A set of similar data, not initially exposed to the ANNs was used to
validate the ability of the ANNs to recognize patterns. The results of this
investigation indicate that the ANNs accurately predicted the water-uptake, glass
transition temperatures and viscosities of different amorphous polymers and their
physical blends with a low % error (0-8%) of prediction. The ANNs also showed
good correlation between the water-uptake and changes in the glass transition
temperatures of the polymers. This study demonstrated the potential of the ANNs
as a preformulation tool to evaluate the characteristics of amorphous polymers.
This is particularly relevant when designing sustained release formulations that
require the use of a fast hydrating polymer matrix.
PMID- 10675706
TI - Viscosity prediction of lipophilic semisolid emulsion systems by neural network
modelling.
AB - Previously published data (Gasperlin et al., 1998) on viscoelastic behaviour of
lipophilic semisolid emulsion systems and the prediction of their physical
stability by neural network modelling are analysed in further detail. Most
attention has been paid to viscosity, which with storage (G') and loss modulus
(G"), is one of the most important rheological parameters influenced by
structure. Complex dynamic viscosity (eta*) was measured by oscillatory
rheometry. The viscosity dependence of the lipophilic semisolid emulsions on the
ratio of the particular components was defined by the neural network (error back
propagation algorithm), linear and incomplete polynomial models of higher orders.
Polynomial models were used to complement the neural network model and to
determine the relationship between variables. Since the viscosity was expressed
in the whole measured frequency range, modelling was more complex and indirect
modelling was introduced. The determined models were tested and the results
confirm their usefulness for the explanation and prediction of the rheological
characteristics of emulsion systems. The trained and tested neural network model
proved to be a highly effective and applicable tool for predicting the viscosity
of a lipophilic semisolid emulsion system of given composition.
PMID- 10675707
TI - Study on glycolic acid delivery by liposomes and microspheres.
AB - Glycolic acid is used in many cosmetic products as exfoliant and moisturizer.
Unfortunately, the greater glycolic acid cosmetic benefits the greater is the
potential for skin irritation as far as burning. The aim of this work was to
investigate the feasibility of topical controlled delivery systems loading
glycolic acid in order to optimize the acid cosmetic properties lowering its side
effects. For this purpose different types of microparticulate systems have been
evaluated: liposomes, liposomes modified by chitosan addition and chitosan
microspheres. Liposomes, composed of phosphatidylcholine and cholesterol (1:1
molar ratio) and with different glycolic acid/lipid molar ratio, were prepared by
reverse phase evaporation method. Two types of interaction between liposomes and
chitosan were investigated: chitosan addition into lipidic bilayer during
liposome preparation and coating of already formed liposomes with chitosan.
Glycolic acid loaded chitosan microspheres were prepared by the dry-in-oil
emulsion method. The microparticulate systems were morphologically characterized
by electron microscopy and particle size analysis. In vitro dissolution tests
were performed to evaluate the feasibility of microparticulate systems in
modulating glycolic acid release. The results obtained show that liposomes are
always suitable to modulate glycolic acid release and that the best condition to
achieve this control is obtained by the liposomal systems in which glycolic
acid/lipid molar ratio is 5:1. Further significant release control is obtained by
addition of chitosan into the liposomes, while chitosan microspheres are not able
to control glycolic acid release even after crosslinking.
PMID- 10675708
TI - Oestradiol skin delivery from ultradeformable liposomes: refinement of surfactant
concentration.
AB - The aims of this study were to refine ultradeformable liposomes for oestradiol
skin delivery and to evaluate Span 80 and Tween 80 as edge activators compared
with sodium cholate. Vesicles containing phosphatidylcholine (PC) mixed with edge
activators and oestradiol were prepared. Entrapment efficiency and vesicle size
were determined. Interactions between activators and vesicles were investigated
using differential scanning calorimetry. Transepidermal permeation of oestradiol
from vesicles was studied compared to saturated aqueous control in vitro. The
maximum flux (J(max)) and its time (T(max)) were calculated from the flux curves
and skin deposition was assessed. The compositions of refined formulations were
predicted, liposomes prepared, and tested against control. Entrapment efficiency
depended on PC concentration with some contribution from sodium cholate and Tween
80. Vesicle sizes ranged from 124 to 135 nm. Edge activators interacted with
lipid bilayers and disrupted packing. The refined edge activator concentrations
in PC vesicles were 14.0, 13.3 and 15.5% w/w for sodium cholate, Span 80 and
Tween 80, respectively; they increased J(max) by 18, 16 and 15-fold and skin
deposition by 8, 7 and 8-fold compared with control. Ultradeformable vesicles
thus improved skin delivery of oestradiol compared to control and Span 80 and
Tween 80 were equivalent to sodium cholate as edge-activators.
PMID- 10675709
TI - Effect of formulation and processing variables on the characteristics of
microspheres for water-soluble drugs prepared by w/o/o double emulsion solvent
diffusion method.
AB - 80% except for acetaminophen, due to its lower solubility in water and higher
solubility in corn oil. The release profile of the drug was pH dependent. In
acidic medium, the release rate was much slower, however, the drug was released
quickly at pH 7.4. Tacrine showed unexpected release profiles, probably due to
ionic interaction with polymer matrix and the shell structure and the highest
release rate was obtained at pH 2.0. The prepared microspheres had a sponge-like
inner structure with or without central hollow core and the surface was dense
with no apparent pores.
PMID- 10675710
TI - The degradation of N,N',N"-triethylenephosphoramide in aqueous solutions: a
qualitative and kinetic study.
AB - The degradation of N,N',N"-triethylenephosphoramide (TEPA) in aqueous solutions
has been investigated over a pH range of 3-14. Samples were analyzed using a gas
chromatographic system with nitrogen/phosphorus selective detection. The
degradation kinetics were studied as function of pH, sodium chloride
concentration and temperature. The degradation of TEPA in buffers follows pseudo
first order kinetics. The logk(obs)8 the methoxy derivative of TEPA was formed,
as a consequence of the applied procedure.
PMID- 10675711
TI - Pulmonary deposition of lactose carriers used in inhalation powders.
AB - Dry powder dosage forms are generally formulated by mixing the micronized drug
particles with the larger carrier particles. Lactose is a commonly used carrier.
Carriers enhance the flowability of powder mixtures and therefore enable low
dosing of active substances. During inhalation, the drug particles are dispersed
from the surface of carrier particles. The aim of this study was to compare how
different qualities of 99mTc-labelled lactose carrier systems deposit in the
lungs. The sizes of the labelled and unlabelled alpha-lactose monohydrate
particles were compared by using a laser diffraction method. Distribution of
radiolabel between different particle size fractions was determined using the
Andersen cascade impactor. The in vivo depositions of lactose carrier systems
were investigated in ten healthy men using the technique of gammascintigraphy. In
addition, redispersion of budesonide from the carrier materials was evaluated by
using the Andersen cascade impactor. According to the validation data the
particle size of the lactose carriers remained unchanged during the labelling
process. Low pulmonary deposition varying between 2.5 and 3.3% was detected. Only
a small amount of lactose was deposited in the lungs, thus pulmonary deposition
is not a limiting factor for lactose selection. According to in vitro
redispersion data the fine particle fraction of the delivered dose in the
impactor varied between 10.3 and 26.0%. Thus, the redispersion of the budesonide
particles can be altered by the properties of the carrier system.
PMID- 10675712
TI - Effect of vehicles and pressure sensitive adhesives on the permeation of tacrine
across hairless mouse skin.
AB - The purpose of this study was to investigate the feasibility of developing
transdermal drug delivery (TDD) system for tacrine used for treating the symptoms
of Alzheimer's disease. The effects of various vehicles on the percutaneous
absorption of tacrine in solution formulation and in pressure sensitive adhesive
(PSA) matrix across the hairless mouse skin were evaluated using flow-through
diffusion cell system at 37 degrees C. The permeation profiles of tacrine from
solutions were different depending on vehicles used. The flux of tacrine
increased significantly as its concentration in the solutions increased. The
permeation rate of tacrine was higher in acrylic adhesives with hydroxyl
functional group and without functional group than in polyisobutylene adhesive
matrix. Incorporation of vehicles into the acrylic adhesive matrix significantly
enhanced the permeation rate and shortened the lag time of tacrine. The maximum
flux obtained from pressure sensitive adhesive matrix seemed to be high enough to
obtain therapeutic effect.
PMID- 10675713
TI - Gentamicin encapsulation in PLA/PLGA microspheres in view of treating Brucella
infections.
AB - In view of treating intracellular Brucella infections, microspheres made of
poly(lactide) (PLA) and poly(lactide-co-glycolide) (PLGA) were developed as
delivery system for the cationic and highly hydrophilic antibiotic gentamicin
sulphate. Drug microencapsulation by spray drying yielded microspheres with
regular morphology, an average particle size of approximately 3 micrometer and
encapsulation efficiencies of up to 45%. Different copolymers of similar
molecular weights gave varying encapsulation efficiencies and particle size
distributions. The encapsulation efficiency generally increased with polymer
hydrophilicity, except for the hydrophilic copolymer PLGA50:50H carrying
carboxylic end groups. Encapsulation also depended on the pH value of the aqueous
drug solution to be encapsulated. Moreover, increasing nominal gentamicin
sulphate loading yielded lower efficiencies. For comparison, some formulations
were also prepared by a (W(1)/O)W(2)-solvent evaporation method, which yielded
lower encapsulation efficiencies, in the order of 13%. Finally, drug bioactivity
was found to remain intact after microencapsulation, MS storage and MS incubation
in aqueous medium. The results suggest that PLA/PLGA microspheres prepared by
spray drying may be an appropriate delivery system for gentamicin sulphate to be
used in the treatment of intracellular Brucella infections.
PMID- 10675714
TI - Predictions of coronary artery stenosis by artificial neural network.
AB - Data from angiography patient records comprised 14 input variables of a neural
network. Outcomes (coronary artery stenosis or none) formed both supervisory and
output variables. The network was trained by backpropagation on 332 records,
optimized on 331 subsequent records, and tested on final 100 records. If 0.40 was
chosen as the output distinguishing stenosis from no stenosis, 81 patients who
had stenosis would have been identified, while 9 of 19 patients who did not have
stenosis might have been spared angiography. The results demonstrated that
artificial neural networks could identify some patients who do not need coronary
angiography.
PMID- 10675715
TI - Generating concise and accurate classification rules for breast cancer diagnosis.
AB - In our previous work, we have presented an algorithm that extracts classification
rules from trained neural networks and discussed its application to breast cancer
diagnosis. In this paper, we describe how the accuracy of the networks and the
accuracy of the rules extracted from them can be improved by a simple pre
processing of the data. Data pre-processing involves selecting the relevant input
attributes and removing those samples with missing attribute values. The rules
generated by our neural network rule extraction algorithm are more concise and
accurate than those generated by other rule generating methods reported in the
literature.
PMID- 10675716
TI - Planning treatment of ischemic heart disease with partially observable Markov
decision processes.
AB - Diagnosis of a disease and its treatment are not separate, one-shot activities.
Instead, they are very often dependent and interleaved over time. This is mostly
due to uncertainty about the underlying disease, uncertainty associated with the
response of a patient to the treatment and varying cost of different diagnostic
(investigative) and treatment procedures. The framework of partially observable
Markov decision processes (POMDPs) developed and used in the operations research,
control theory and artificial intelligence communities is particularly suitable
for modeling such a complex decision process. In this paper, we show how the
POMDP framework can be used to model and solve the problem of the management of
patients with ischemic heart disease (IHD), and demonstrate the modeling
advantages of the framework over standard decision formalisms.
PMID- 10675718
TI - Foreword.
PMID- 10675717
TI - Automatic analysis of signals with symbolic content.
AB - This paper presents a set of methods for helping in the analysis of signals with
particular features that admit a symbolic description. The methodology is based
on a general discrete model for a symbolic processing subsystem, which is
fuzzyfied by means of a fuzzy inference system. In this framework a number of
design problems have been approached. The curse of dimensionality problem and the
specification of adequate membership functions are the main ones. In addition,
other strategies, which make the design process simpler and more robust, are
introduced. Their goals are automating the production of the rule base of the
fuzzy system and composing complex systems from simpler subsystems under symbolic
constrains. These techniques are applied to the analysis of wakefulness episodes
in the sleep EEG. In order to solve the practical difficulty of finding
remarkable situations from the outputs of the symbolic subsystems an unsupervised
adaptive learning technique (FART network) has been applied.
PMID- 10675719
TI - Unraveling the role of proteases in cancer.
AB - Investigators have been studying the expression and activity of proteases in the
final steps of tumor progression, invasion and metastasis, for the past 30 years.
Recent studies, however, indicate that proteases are involved earlier in
progression, e.g., in tumor growth both at the primary and metastatic sites.
Extracellular proteases may co-operatively influence matrix degradation and tumor
cell invasion through proteolytic cascades, with individual proteases having
distinct roles in tumor growth, invasion, migration and angiogenesis. In this
review, we use cathepsin B as an example to examine the involvement of proteases
in tumor progression and metastasis. We discuss the effect of interactions among
tumor cells, stromal cells, and the extracellular matrix on the regulation of
protease expression. Further elucidation of the role of proteases in cancer will
allow us to design more effective inhibitors and novel protease-based drugs for
clinical use.
PMID- 10675720
TI - An overview of collagenase-3 expression in malignant tumors and analysis of its
potential value as a target in antitumor therapies.
AB - Collagenase-3 (MMP-13) is a member of the matrix metalloproteinase family of
endopeptidases that is characterized by a potent degrading activity against a
wide spectrum of substrates. This enzyme was first detected in breast carcinomas
but it is also overexpressed in a variety of malignant tumors including head and
neck carcinomas, chondrosarcomas, skin carcinomas, and carcinomas of the female
genital tract. Clinical studies have revealed that in all these tumors
collagenase-3 expression is associated with invasive and metastatic tumors.
Analysis of the molecular mechanisms underlying its marked overexpression in
malignant tumors has allowed to identify different cytokines, growth factors and
tumor promoters with ability to up-regulate collagenase-3 expression in tumor
cells, or in stromal fibroblasts surrounding epithelial tumor cells. The first
strategies designed to target this enzyme are being developed, and are mainly
directed to prepare synthetic inhibitors with ability to selectively block the
collagenase-3 proteolytic activity. Alternatively, inhibitors of the signal
transduction pathways mediating the expression of this enzyme by tumor cells may
also be useful for collagenase-3 targeting. These studies together with those
performed on other enzymes associated with tumor processes may lead to the
development of novel therapeutic strategies to control the progression and
metastatic capacity of neoplastic cells.
PMID- 10675721
TI - Cathepsin D in breast cancer: mechanisms and clinical applications, a 1999
overview.
AB - A short review of the literature first confirms the clinical value of cathepsin D
as a prognostic marker in breast cancer, when using well standardized assays. We
then summarize results of studies, mostly performed in our laboratory, aimed at
understanding the effect of cathepsin D overexpression on metastasis and the
molecular mechanisms involved. Cathepsin D-cDNA transfection increases tumor cell
proliferation in vitro and the metastatic potential of 3Y1-Ad12 embryonic rat
tumorigenic cells when injected in vivo into nude mice. The mechanism by which
cathepsin D increases the incidence of clinical metastasis involves increased
cell growth and decreased contact inhibition rather than escape of cancer cells
through the basement membrane. Different mechanisms are considered to explain
this mitogenic activity. Cathepsin D could act as a protease following its
activation at an acidic pH, or as a ligand of different membrane receptors at a
more neutral pH. In this case cathepsin D can displace IGFII from the mannose-6
phosphate/IGFII receptor to the IGFI receptor or activate another membrane
receptor to be identified. The nature of the mechanisms involved in vivo may
depend on the micro environment of the tumor cells. These studies should guide in
the development of new therapies aimed at inhibiting the deleterious effect of
overexpressed cathepsin D.
PMID- 10675722
TI - Proteases in gastrointestinal neoplastic diseases.
AB - Cysteine and serine proteases are involved in cancer invasion and metastasis. In
the past few years we investigated the tissue levels of these proteases in
gastric cancer (GC), gastric precancerous changes (CAG), colorectal cancer (CRC)
and the plasma and serum levels of proteases in several gastrointestinal tumours,
using ELISA methods. Significantly higher antigen levels were found not only in
GC tissue but also in CAG with respect to the levels found normal tissue; with
respect to CAG, patients with dysplasia had higher levels than patients without
dysplasia. The same findings were obtained in CRC. In general protease levels
correlated with the major histomorphological parameters, such as grading and
histotype in GC as well as in CRC. Tissue protease levels had a strong prognostic
impact in GC, in which UPA was singled out by multivariate analysis as the major
prognostic factor, and CRC. The plasma levels of urokinase-type plasminogen
activator (UPA) and the serum levels of cathepsin B were significantly increased
in patients with gastrointestinal tumours. In conclusions, cysteine and serine
proteases may have a part not only in GC and CRC invasion and metastasis, but
also in the progression of gastric precancerous changes into cancer. They are
strong prognostic factors in GC and CRC. These proteases may also have a role as
tumour markers in the early diagnosis of gastrointestinal tract tumours.
PMID- 10675723
TI - Bacterial toxins with intracellular protease activity.
AB - The recent determination of their primary sequence has lead to the discovery of
the metallo-proteolytic activity of the bacterial toxins responsible for tetanus,
botulism and anthrax. The protease domain of these toxins enters into the cytosol
where it displays a zinc-dependent endopeptidase activity of remarkable
specificity. Tetanus neurotoxin and botulinum neurotoxins type B, D, F and G
cleave VAMP, an integral protein of the neurotransmitter containing synaptic
vesicles. Botulinum neurotoxins type A and E cleave SNAP-25, while the type C
neurotoxin cleaves both SNAP-25 and syntaxin, two proteins located on the
cytosolic face of the presynaptic membrane. Such specific proteolysis leads to an
impaired function of the neuroexocytosis machinery with blockade of
neurotransmitter release and consequent paralysis. The lethal factor of Bacillus
anthracis is specific for the MAPkinase-kinases which are cleaved within their
amino terminus. In this case, however, such specific biochemical lesion could not
be correlated with the pathogenesis of anthrax. The recently determined sequence
of the vacuolating cytotoxin of Helicobacter pylori contains within its amino
terminal domain elements related to serine-proteases, but such an activity as
well as its cytosolic target remains to be detected.
PMID- 10675724
TI - Proteases in the evaluation of pancreatic function and pancreatic disease.
AB - This paper reviews the role of pancreatic proteases (focusing upon trypsin,
chymotrypsin and elastase) in the diagnosis and management of chronic pancreatic
insufficiency (CPI), emphasizing advances over the last 5 years. Some important
novel aspects of these enzymes in acute pancreatitis are also described,
including their role in diagnosis and their interaction with cholecystokinin in
the pathogenesis of the disease. The recent interest in these enzymes as agents
promoting the spread of cancer in animals and human subjects is also described. A
hierarchical approach has been taken to explore the advantages and limitations of
tests in different source materials: serum, feces, duodenal aspirate, and non
invasive pancreatic function tests. The practical usefulness of fecal elastase-1
and of fecal chymotrypsin concentrations in diagnosis and management of CPI,
respectively, is one of the major lessons to be learned from analysis of the
recent literature, and forms the principal message of this review.
PMID- 10675725
TI - Proteinases in bone resorption: obvious and less obvious roles.
AB - Bone resorption is critical for the development and the maintenance of the
skeleton, and improper regulation of bone resorption leads to pathological
situations. Proteinases are necessary for this process. In this review, we show
that this need of proteinases is not only because they are required for the
solubilization of bone matrix, but also because they are key components of the
mechanism that determines where and when bone resorption will be initiated.
Moreover, there are indications that proteinases may also determine whether
resorption will be followed by bone formation. Some of the proteinases involved
in these different steps of the resorption processes were recently identified, as
for instance cathepsin K, MMP-9 (gelatinase B), and interstitial collagenase.
However, there is also increasing evidence showing that the critical
proteinase(s) may vary depending on the bone type or on other factors.
PMID- 10675726
TI - Tissue factor in human coronary atherosclerotic plaques.
AB - The rupture or fissuring of a coronary atherosclerotic plaque and subsequent
thrombosis is considered the key event in the pathogenesis of unstable angina and
myocardial infarction. Although plaque disruption frequently occurs during the
evolution of atherosclerosis, only a minority of ruptured plaques develop
thrombosis. The content and procoagulant activity of tissue factor in human
coronary atherosclerotic plaques varies widely, and different studies confirm
that it is higher in the plaques extracted from patients with unstable angina,
myocardial infarction or histologic/angiographic evidence of coronary thrombosis
than in those taken from patients with stable angina or uncomplicated coronary
lesions. Variations in tissue factor content and activity may be responsible for
the different thrombotic responses to human coronary atherosclerotic plaque
rupture.
PMID- 10675727
TI - Inhibition of cytosolic phospholipase A(2) attenuates activation of mitogen
activated protein kinases in human monocytic cells.
AB - Eicosanoids and platelet-activating factor generated upon activation of cytosolic
phospholipase A(2) enhance activity of transcription factors and synthesis of
proinflammatory cytokines. Here, we show that selective inhibitors and antisense
oligonucleotides against this enzyme suppressed expression of the interleukin
1beta gene at the level of transcription and promoter activation in human
monocytic cell lines. This inhibitory effect was due to failure of activation of
mitogen-activated protein kinases (MAPK) through phosphorylation by upstream
mitogen-activated protein kinase kinases (MKK). Consequently, phosphorylation and
degradation of inhibitor-kappaBalpha (I-kappaBalpha) and subsequent cytoplasmic
mobilization, DNA-binding and the transactivating potential of nuclear factor
kappaB (NF-kB), nuclear factor-interleukin-6 (NF-IL6), activation protein-1 (AP
1) and signal-transducer-and-activator-of-transcription-1 (STAT-1) were impaired.
It is concluded, that lipid mediators promote activation of MAPKs, which in turn
lead to phosphorylation and liberation of active transcription factors. Since
inhibition of cytosolic phospholipase A(2) ameliorates inflammation in vivo, this
potency may reside in interference with the MAPK pathway.
PMID- 10675728
TI - Nifedipine does not induce but rather prevents apoptosis in cardiomyocytes.
AB - The potential of Ca(2+) channel antagonists, particularly nifedipine, to cause
apoptotic cell death has been controversial and is of considerable importance for
cardiomyocytes as loss of these cells is an important component of the
pathophysiology leading to heart failure. To examine the hypothesis that
nifedipine induces cell death and modulates calcium-induced apoptosis,
cardiomyocytes in culture from embryonic chick hearts, that readily manifest
apoptosis, were studied. Apoptosis was evaluated by fluorescent activated cell
sorting (FACS) analysis and by quantitative analysis of DNA fragmentation by an
enzyme-linked immunosorbent assay (ELISA) specific for histone-associated DNA
fragments of mono- and oligonucleosome size. Cell death was evaluated by using
the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay.
Cardiomyocytes were treated with various concentrations of nifedipine over a
concentration range relevant to serum concentrations in man. Nifedipine, 1 to 100
microM, did not produce cell death in cardiomyocytes. There was no evidence of
apoptosis on FACS analysis of cardiomyocytes stained with fluoresceine diacetate
or propidum iodide (PI). Neither was there any evidence of apoptotic nuclei on PI
staining of permeabilized cardiomyocytes treated with nifedipine. In contrast,
DNA fragmentation consistent with apoptosis was induced in a significant (P<0.05)
concentration-dependent manner, by increases in extracellular Ca(2+)
concentration ([Ca(2+)](o)). Importantly, nifedipine reduced DNA fragmentation
produced by increased [Ca(2+)](o). Furthermore, nifedipine blocked calcium
induced cell death as high [Ca(2+)](o) significantly (P<0. 05) reduced cell
viability. These data indicate that nifedipine does not induce apoptosis in
cardiomyocytes rather apoptosis in cardiomyocytes is under regulatory control by
Ca(2+) and nifedipine can antagonize Ca(2+)-mediated apoptotic cell death.
PMID- 10675729
TI - Myelopoietic response in tumour-bearing mice by an aggregated polymer isolated
from Aspergillus oryzae.
AB - The effects of magnesium ammonium phospholinoleate-palmitoleate anhydride (MAPA),
a proteic aggregated polymer isolated from Aspergillus oryzae, on the growth and
differentiation of granulocyte-macrophage progenitor cells (colony-forming unit
granulocyte-macrophage [CFU-GM]) in normal and Ehrlich ascites tumour-bearing
mice were studied. Myelosuppression concomitant with increased numbers of spleen
CFU-GM was observed in tumour-bearing mice. Treatment of these animals with MAPA
(0.5-10 mg/kg) stimulated marrow myelopoiesis in a dose-dependent manner and
reduced spleen colony formation. No changes were observed in total and
differential marrow cell counts. The dose of 5.0 mg/kg MAPA, given prior or after
tumour inoculation, was the optimal biologically active dose in tumour-bearing
mice and this dose schedule also stimulated myelopoiesis in normal mice. MAPA
significantly enhanced survival and concurrently reduced tumour growth in the
peritoneal cavity. We propose that the modulatory effect of MAPA on the
myelopoietic response may be related to its antitumour activity as a possible
mechanism for regulation of granulocyte-macrophage production and expression of
functional activities.
PMID- 10675730
TI - cAMP-Dependent potentiation of the Ca(2+)-activated release of the anionic
fluorescent dye, calcein, from rat parotid acinar cells.
AB - A recent study indicates that elevation of [Ca(2+)](i) enhances the release of
calcein, an anionic fluorescent dye, from isolated exocrine acinar cells, so
cytoplasmic calcein is useful for monitoring the secretion of organic anions. In
this study, we investigated the effect of cAMP on the calcein release evoked by
elevation of [Ca(2+)](i). Isoproterenol, forskolin and dibutyryl cyclic AMP
(dbcAMP) did not induce the release of calcein from isolated parotid acinar
cells, but they potentiated the carbachol-induced release of calcein. Although
cytoplasmic calcein is released through an increase in [Ca(2+)](i), isoproterenol
potentiated the carbachol-induced release of calcein without affecting the
increase in [Ca(2+)](i) evoked by a high concentration of carbachol (10(-6) M).
Charybdotoxin, a K(+) channel blocker, inhibited both the carbachol-induced
release and the potentiation by isoproterenol. However, the calcein permeation
pathways mediating the carbachol-induced release and the isoproterenol
potentiated release exhibited distinct sensitivities to anion channel blockers.
Our results indicate that the calcein release induced by carbachol is potentiated
through an increase in intracellular levels of cAMP. Although both the Ca(2+)
activated release and the cAMP-potentiated release may be coupled to Ca(2+)
activated K(+) efflux, increases in both [Ca(2+)](i) and [cAMP](i) may activate
the calcein conduction pathway which is not activated by an increase in
[Ca(2+)](i) alone.
PMID- 10675731
TI - Binding properties of [3H]gacyclidine in the rat central nervous system.
AB - Gacyclidine (1-[1-(2-thienyl)-2-methylcyclohexyl]piperidine), the racemate of (+)
and (-)-GK11, exhibits potent neuroprotective properties due to its antagonism at
the NMDA receptor. In its tritiated form, gacyclidine showed a binding
distribution similar to that of NMDA receptors in the rat brain. With membrane
preparations, the (-)-enantiomer of gacyclidine exhibited an affinity similar to
that of MK-801 (dizocilpine, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,
d]cyclohepten-5,10-imine) in the low nanomolar range, while the (+)-enantiomer
was about 10 times less potent. Gacyclidine affinity was lower in the cerebellum
than in the forebrain or the spinal cord. In this latter region and in the
cerebellum, two binding sites were evidenced, one of which was a low-affinity
site insensitive to MK-801. In all regions, PRE-084 (2-(4-morpholino)ethyl-1
phenylcyclohexane-1-carboxylate), a sigma receptor ligand, had no effect on
[3H]gacyclidine binding.
PMID- 10675733
TI - Roles of adenosine A(1) and A(2A) receptors in the expression and development of
methamphetamine-induced sensitization.
AB - We studied the effects of adenosine A(1) and A(2A) receptor agonists on the
expression and development of methamphetamine-induced sensitization in rats. When
animals were treated with the adenosine A(1) receptor agonist, N(6)
cyclohexyladenosine (CHA), along with methamphetamine every 3 days with a total
of five administrations, the augmentation of hyperlocomotion by methamphetamine
re-administration after 7-day withdrawal (methamphetamine challenge
administration) was not inhibited. However, when the adenosine A(2A) receptor
agonist, 2-p-(2-carboxyethyl) phenethyl-amino-5'-N-ethylcarboxy-amide adenosine
(CGS21680), was administered according to the same schedule, the augmentation was
significantly inhibited. On the other hand, when CHA or CGS21680 was administered
30 min before methamphetamine challenge, both drugs dose-dependently inhibited
the augmentation of hyperlocomotion. These results suggested that both adenosine
A(1) and A(2A) receptors play important roles in the expression of
methamphetamine-induced sensitization, and that adenosine A(2A) receptors do so
in the development of this sensitization.
PMID- 10675732
TI - delta-Opioid receptor agonists produce antinociception and [35S]GTPgammaS binding
in mu receptor knockout mice.
AB - We examined the effects of [D-Pen(2),D-Pen(5)]enkephalin (DPDPE), [D
Ala(2),Glu(4)]deltorphin (DELT), and (+)-4-[(alphaR)-alpha((2S, 5R)-4-Allyl-2,5
dimethyl-1-piperazinyl)-3-methoxybenzyl]-N, N-diethylbenzamide (SNC80) on
[35S]GTPgammaS binding in brain membranes prepared from micro-opioid receptor
knockout (-/-) mice. The potency and maximal response (E(max)) of these agonists
were unchanged compared to control mice. In contrast, while the potency of [D
Pen(2),pCl-Phe(4),D-Pen(5)]enkephalin (pCl-DPDPE) was not significantly
different, the E(max) was reduced as compared to controls. In the tail-flick
test, intracerebroventricular (i.c.v.) or intrathecal (i.th.) DELT produced
antinociceptive effects in -/- mice with potency that did not differ
significantly from controls. In contrast, the antinociceptive potency of i.c.v.
and i.th. DPDPE was displaced to the right by 4- and 9-fold in -/- compared to
control mice, respectively. Reduced DPDPE antinociceptive potency in -/- mice,
taken together with reduced DPDPE- and pCl-DPDPE- stimulated G protein activity
in membranes prepared from -/- mice, demonstrate that these agonists require mu
opioid receptors for full activity. However, because DELT mediated G protein
activation and antinociception were both comparable between -/- and wild type
mice, we conclude that the mu-opioid receptor is not a critical component of
delta-opioid receptor function.
PMID- 10675734
TI - Effect of somatostatin on resistance and on capacitance rabbit isolated arteries.
AB - The effects of somatostatin, a tetradecapeptide isolated from hypothalamus
extracts, were studied on the vascular reactivity of aorta and mesenteric
arteries isolated from rabbits. We also investigated whether or not Ca(2+)
movements were implicated in these effects. Rabbit aorta and mesenteric (fifth
branch) arteries were isolated, cleaned off, and mounted in an organ bath
containing Godfraind solution or physiological saline solution (PSS),
respectively. Somatostatin (10(-8)-10(-4) M) produced a concentration-dependent
inhibition of the contractile responses induced by high K(+) (80 mM) or
noradrenaline (10(-6) M in aorta or 10(-4) M in mesenteric arteries) in both
arteries studied. The inhibitory effect of somatostatin was greater in mesenteric
resistance vessels (IC(50) 3.1+/-2.3x10(-5) M, and 5.2+/-4.8x10(-8) M with KCl
and noradrenaline, respectively). Contractile responses produced by the addition
of Ca(2+) (1-5 mM) to Ca(2+)-free high K(+) solution were also concentration
dependently inhibited by somatostatin in aorta. Furthermore, somatostatin
decreased noradrenaline-induced contraction attributed to intracellular Ca(2+)
release in aorta, and inhibited 45Ca(2+) uptake stimulated by high K(+) or by
noradrenaline. However, it did not modify 45Ca(2+) uptake in resting mesenteric
resistance arteries. Taken together, these results suggest that somatostatin
exerts an inhibitory effect on vascular contractions induced by some stimulating
agents in different arteries isolated from rabbits, being more potent in
mesenteric arteries.
PMID- 10675735
TI - Effects of metoprolol and ramipril on action potentials after myocardial
infarction in rats.
AB - The effects of chronic treatment with the beta-adrenoceptor antagonist
metoprolol, the angiotensin converting enzyme inhibitor ramipril, their
combination, or placebo on action potential configuration 6 weeks after
myocardial infarction in rats were studied. Action potentials were measured in
isolated left ventricular posterior papillary muscles and compared with action
potentials from a sham operated group without infarction. After infarction, the
action potential amplitude was reduced and this phenomenon was partially reversed
by metoprolol- and ramipril-treatment. Prolonged repolarisation after infarction
compared to sham operated animals was additionally delayed after metoprolol
treatment. Thus, metoprolol extends the refractory period, which may counteract
tachyarrhythmia.
PMID- 10675736
TI - Prostaglandin-release impairment in the bladder epithelium of streptozotocin
induced diabetic rats.
AB - Isolated epithelial layer preparations were obtained from urinary bladders of 4
week streptozotocin-diabetic rats and used for endogenous prostaglandins E(2) and
F(2alpha) determination. Tissues were incubated in modified Krebs solution under
basal conditions, or in the presence of either indomethacin (5x10(-7) M), ATP
(10(-5) and 10(-3) M) or bradykinin (10(-7) and 10(-5) M), and samples of
incubation medium were collected at 15 and 30 min. In the presence of
indomethacin, the release of prostaglandins in the incubation medium was under
the detection limit of the enzyme immunoassay (EIA). The epithelium from diabetic
rat urinary bladders was thicker and heavier and the absolute amount of
endogenous prostaglandins E(2) and F(2alpha) was higher than for control animals,
but when prostaglandin production was expressed as a fraction of tissue weight,
it was reduced in diabetic epithelium. ATP and bradykinin has significantly
increased the endogenous release of both prostaglandins from the epithelium when
compared with the release under basal conditions. This increase was time
dependent and was higher in diabetic than in control tissues. ATP evoked a phasic
and tonic contraction in bladder strips that was abolished by epithelium removal.
Concentration-response curves for ATP did not differ among groups. Bradykinin
evoked a long-lasting tonic contraction that was reduced significantly by
epithelium removal in diabetic rat bladders only. Concentration-response curves
for prostaglandin E(2) and F(2alpha) in diabetic rat bladder differed
significantly from that in controls and epithelium removal did not alter these
responses. It is suggested that bradykinin receptors and P2X nucleotide receptors
already found in the smooth muscle detrusor might be present in the epithelial
layer of the bladder. The prostaglandin-release impairment observed in this study
might be responsible, in part, for bladder abnormalities observed in pathological
conditions, such as diabetes.
PMID- 10675737
TI - Urinary nitrate excretion in cholesterol-fed rabbits: effect of a chronic
treatment by N-iminoethyl-L-lysine, a selective inhibitor of inducible nitric
oxide synthase.
AB - To evaluate the influence of atherosclerosis on the global production of NO, we
studied the effect of a 0.3% cholesterol-enriched diet on urinary nitrate
excretion in rabbits during 69 weeks. To examine whether the inducible nitric
oxide synthase (iNOS) present in atherosclerotic lesions could participate in NO
excretion, hypercholesterolemic rabbits were treated chronically with the
selective iNOS inhibitor, N-iminoethyl-L-lysine (L-NIL; 5 mg/kg/day). Urinary
nitrate excretion was higher in hypercholesterolemic than in control rabbits
throughout the study period and decreased progressively with time in both groups;
L-NIL had no significant effect on urinary nitrate excretion. These data
illustrate that systemic NO production is enhanced in hypercholesterolemia and
that iNOS, present within the plaque, might not participate in this enhanced NO
production.
PMID- 10675738
TI - Site-specific lesion formation, inflammation and inducible nitric oxide synthase
expression by indomethacin in the rat intestine.
AB - The involvement of nitric oxide (NO) formed by the inducible isoform of NO
synthase (iNOS) has been investigated in the development of rat intestinal
lesions following indomethacin administration. Over a 72-h period, indomethacin
(10 mg kg(-1), s.c.) provoked a time-dependent increase in expression of iNOS
(assessed by the conversion of radiolabelled L-arginine to citrulline) and
enhancement of vascular leakage of radiolabelled human serum albumin in the
jejunum which commenced 18 h after indomethacin. Similar effects were not
observed in the ileum, colon or caecum. In addition, macroscopic lesions were
detectable and myeloperoxidase activity (an index of neutrophil recruitment) were
increased in the rat jejunum 18-24 h after indomethacin, but remained at basal
levels in the ileum and colon. These findings suggest that indomethacin provokes
a site-selective expression of iNOS in the rat jejunum which correlates with
lesion formation and vascular leakage, whereas both the ileum and colon are
spared.
PMID- 10675739
TI - Systematics of malaria vectors with particular reference to the Anopheles
punctulatus group.
AB - The appearance of groups and complexes of closely related cryptic or sibling
species in many of the anopheline taxa has impeded studies on malaria
transmission and the evaluation of control strategies which have relied on
morphological characters to identify the vector species involved. The advantages
of morphological identification are low cost, speed and simplicity, which allow
large numbers of specimens to be processed rapidly in the field. The need for
accurate identification is crucial, as time and money may be wasted in studying
and controlling species of no medical importance. Various techniques such as
cross-mating, chromosome studies and allozyme analysis have been developed to
resolve problems of identifying sibling species, though none, as yet, can match
the speed and simplicity afforded by morphology markers. The latest of these
identification methods comes from advances that have been made in DNA-based
technology. Although costly and requiring fairly sophisticated laboratory
support, methods such as DNA probe hybridisation and PCR are the quickest and
most user-friendly to date. The use of DNA has other advantages in the study of
intraspecific differences and in providing characters for phylogenetic studies.
This review looks at the development of DNA-based techniques for taxonomic and
systematic studies of anopheline mosquitoes. The Anopheles punctulatus group of
the southwest Pacific is featured as an example of how this technology has been
applied and how it has progressed.
PMID- 10675740
TI - A comparative survey of the hydrolytic enzymes of ectoparasitic and free-living
mites.
AB - Extracts of ectoparasitic mites of birds (Dermanyssus gallinae), sheep (Psoroptes
ovis) and plants (Tetranychus urticae) and of free-living mites (Acarus siro)
contained acid and alkaline phosphatase, C4 and C8 esterases, lipase, leucine and
valine aminopeptidases and a range of glycosidase activities. Dermanyssus
gallinae and P. ovis, species highly adapted to an animal parasitic lifestyle,
had very similar profiles and contained low activities of glycosidases. In
contrast, the polyphagous species A. siro contained moderate to high activities
of every glycosidase examined, whereas the phytophagous species, T. urticae,
displayed high activities of only beta-galactosidase and beta-glucuronidase. All
extracts hydrolysed haemoglobin with optima below pH6, and this hydrolysis was
associated with an aspartic proteinase and variable cysteine proteinase activity
dependent on species. Inhibitor-labelling with biotinyl-Phe-Ala-FMK revealed the
presence of cysteine proteinases with molecular masses of 25-33.5kDa. Each mite
species contains the enzymes necessary to complete digestion of the diet in the
intracellular lysosomal compartment. The absolute and relative activities of each
enzyme varied, and are discussed according to phylogeny and dietary habit.
PMID- 10675741
TI - Comparative metal content profiling of parasitic helminths by electron
paramagnetic resonance spectrometry: significance for metalloprotein content.
AB - Variation in co-ordination geometries of metal ions bound to proteins imposes
electronic states different from free (hydrated) ions in solution. Electron
paramagnetic resonance spectroscopy has been used to analyse a selection of
parasitic helminths for metal content as an initial step to determination of
metallo-enzymes in their ES products under immune stress conditions.
Characteristic paramagnetic resonance spectroscopy spectra show clear evidence
for the presence of iron, copper, and manganese centres and in the selected
parasites. The metals ions are identified as protein-bound as distinct from free
metal ions present in aqueous solution, and distinguishable from parasite dietary
components derived from host sources. Indication is given that superoxide
dismutases may, in part, account for the metal ions observed. The use of electron
paramagnetic resonance spectroscopy to identify specific protein-bound metals
without prior isolation of the suspected protein is here applied.
PMID- 10675742
TI - Identification of six Trypanosoma cruzi phylogenetic lineages by random amplified
polymorphic DNA and multilocus enzyme electrophoresis.
AB - Genetic characterisation of Trypanosoma cruzi variants is of foremost importance,
due to considerable genetic and biological heterogeneity in the parasite
populations. Two major phylogenetic lineages, each highly heterogeneous, have
been previously described within this species. Here we characterised a
geographically and ecologically diverse sample of stocks representative of the
breadth of the known clonal diversity of each major lineage, using random
amplified polymorphic DNA with 20 primers and multilocus enzyme electrophoresis
at 22 loci. Molecular hybridisation experiments were performed to control the
homology of randomly amplified DNA markers. Both sets of data were highly
consistent and supported the existence of two major lineages. Additionally, we
found that lineage 2 appeared further partitioned into five sharply delineated
phylogenetic clusters, each comprising one of the following reference strains:
CanIII cl1 (Z3 reference), M5631 cl5, Esmeraldo cl3 (Z2 reference), CL Brener,
and MN cl2. The two first clusters were found mainly in sylvatic environments,
whereas the three latter were restricted to domestic transmission cycles and were
only collected South to the Amazon Basin. In contrast, lineage 1, which included
Miles' Z1 reference strain X10 cl1, was not further subdivided and was
encountered across the entire endemic area, in both domestic and sylvatic cycles.
Thus, T. cruzi appeared to be subdivided into six discrete typing units, or DTUs,
exhibiting distinct geographic and ecological ranges. Reliable diagnostic markers
for the two major lineages and the five smaller DTUs of lineage 2 are described,
and correspondence with previous classifications of T. cruzi genotypes is given
in order to help communication on T. cruzi phylogenetic diversity.
PMID- 10675743
TI - Characterisation of the proximal regulatory domain of the Echinococcus granulosus
homeodomain-containing gene EgHbx1.
AB - In an attempt to understand the molecular basis of the development of
Echinococcus granulosus, we have previously isolated several homeobox-containing
genes (EgHbx1-5). Here we report the characterisation of the EgHbx1 proximal
regulatory domain. EgHbx1 codes for an amino acid sequence presenting 90%
identity at the homeodomain level with the Drosophila melanogaster NK1-S59
transcription factor. The proximal regulatory domain sequence and the
transcription start site were determined. Electrophoretic mobility shift assays
using nuclear extracts from protoscoleces revealed the presence of specific DNA
protein complexes. These results constitute a hint and provide new tools to
decipher regulatory cascades during E. granulosus development.
PMID- 10675745
TI - A common high molecular weight antigen of Babesia bovis isolates from Mexico.
AB - Cattle from an area of Mexico endemic with Babesia bovis infections have a
dominant antibody response to a 152kDa antigen of the Tamaulipas strain of B.
bovis. A mAb termed PB/5, showing a specific reactivity to this 152kDa antigen in
Western blots, was identified. The mAb which reacted with the blunt end of B.
bovis in an indirect fluorescent antibody test also reacted to a 152kDa antigen
in two other isolates (Nuevo Leon and Yucatan), and a 175kDa antigen in the
Huasteca B. bovis isolate from Mexico. Polyclonal monospecific sera from a calf
inoculated with mAb-affinity purified 152kDa antigen (Tamaulipas strain)
identified B. bovis by the indirect fluorescent antibody test and two antigens of
B. bovis (65kDa and 152kDa) in Western blot. Since the epitope reacting to the
mAb PB/5 is conserved, this antigen provides a basis for developing a diagnostic
test or an immunogen.
PMID- 10675744
TI - Monoclonal antibody inhibition of Neospora caninum tachyzoite invasion into host
cells.
AB - Monoclonal antibodies were produced against Neospora caninum tachyzoites to
identify antigens which may play a role during invasion of host cells. Confocal
laser microscopy showed that most antigens recognised by the mAb were located on
the surface, but one mAb, 1A5, reacted to the apical end of the parasite. Some
mAbs, which recognised 70, 42 and 36kDa parasite proteins, significantly
inhibited the invasion of the parasite in vitro. The mAbs which recognised 42 and
36kDa parasite protein, reacted with Nc-p43 and Nc-p36 expressed by vaccinia
virus and Escherichia coli, respectively. These results suggest that a 70kDa
protein, Nc-p43 and Nc-p36 are involved in the invasion of the parasite into host
cells.
PMID- 10675746
TI - Survival of bird schistosomes in mammalian lungs.
AB - Bird schistosome cercariae have a low specificity to vertebrate skin and, thus,
they are also able to penetrate into mammals. As a consequence, a hypersensitive
skin response-cercarial dermatitis-develops. It was thought that the parasites
die in the skin soon after penetration. Our results on Trichobilharzia szidati
and Bilharziella polonica in the non-specific murine host confirm that some of
the penetrating bird schistosomes may fully transform to schistosomula and
migrate to the lungs. They persist there for up to 10days post exposure. In a
duck, the worms grow and feed rapidly, but in a mouse the lung schistosomula seem
to be inhibited in their development. However, TEM results show that there is no
damage to the tegument of these larvae and no immune effector cells attack the
parasites. These results suggest that the parasite's failure in the murine host
might be caused by some immunologically unrelated factors.
PMID- 10675747
TI - Identification of a 200- to 300-fold repetitive 529 bp DNA fragment in Toxoplasma
gondii, and its use for diagnostic and quantitative PCR.
AB - We have identified a novel 529bp fragment that is repeated 200- to 300-fold in
the genome of Toxoplasma gondii. This 529bp fragment was utilised for the
development of a very sensitive and specific PCR for diagnostic purposes, and a
quantitative competitive-PCR for the evaluation of cyst numbers in the brains of
chronically infected mice. The 529bp fragment was found in all 60 strains of T.
gondii tested, and it discriminates DNA of T. gondii from that of other
parasites. Toxoplasma gondii DNA was detected in amniotic fluid of patients, as
well as in various tissues from infected mice. Polymerase chain reaction with the
529bp fragment was more sensitive than with the 35-copy B1 gene. For the
quantitative competitive-PCR, a 410-bp competitor molecule was co-amplified with
similar efficiency as the 529bp fragment. Quantitative competitive-PCR produced a
linear relationship between the relative amounts of PCR product and the number of
tachyzoites in the range of 10(2)-10(4) tachyzoites and 100-3000 tissue cysts. A
highly significant correlation between visual counting of brain cysts and
quantitative competitive-PCR was obtained in mice chronically infected with
Toxoplasma. Thus, quantitative competitive-PCR with the 529bp fragment can be
used as an alternative for the tedious visual counting of brain cysts in
experimental animals. With the quantitative competitive-PCR, furthermore, we
could confirm the copy number of the 529bp fragment in tachyzoites and estimate
the number of bradyzoites per cyst.
PMID- 10675749
TI - Phylogenetic analysis of the suborder plagiorchiata (Platyhelminthes, Digenea)
based on partial lsrDNA sequences.
AB - The phylogenetic relationships and systematic position of the members of the
suborder Plagiorchiata, one of the derived and most diverse groups of Digenea,
have always been controversial. Here, we present a phylogeny of this group based
on the analysis of partial sequences of the lsrDNA in 28 species representing 13
families of Plagiorchiata, as well as four outgroups. Our results show that the
Plagiorchiata, as considered by most authors, is not monophyletic, and that the
superfamilies Opecoeloidea, and most probably Dicrocoelioidea and Gorgoderoidea,
may have to be removed from this suborder. According to our results, the
Plagiorchiata includes only parasites of terrestrial vertebrates. We find the
Plagiorchiata to be composed of two well-supported clades which can be ranked as
superfamilies: (1) Plagiorchioidea, including the Plagiorchiidae,
Haematoloechidae, Telorchiidae, Brachycoeliidae and Leptophallidae; and (2)
Microphalloidea containing the Microphallidae, Prosthogonimidae,
Lecithodendriidae and Pleurogenidae. The genetic analysis also allowed revision
of the position of several taxa of Plagiorchiata, including: (1) a confirmation
of the position of the Brachycoeliidae within the Plagiorchiata; (2) a close
phylogenetic relationships of Macrodera with Paralepoderma, Leptophallus and
Metaleptophallus; (3) the grouping of Opisthioglyphe and Telorchis within a
distinct and strongly supported clade; and (4) the placement of Allassogonoporus
amphoraeformis within the Pleurogenidae, and not close to Lecithodendriidae. Some
systematic changes, corresponding to these results, are proposed.
PMID- 10675748
TI - Molecular cloning and characterisation of a venom allergen AG5-like cDNA from
Meloidogyne incognita.
AB - RNA fingerprinting was used to identify RNAs that were expressed in parasitic
second-stage juveniles of Meloidogyne incognita, but absent from or reduced in
preparasitic second-stage juveniles. A cDNA encoding a putative secretory protein
was cloned from a M. incognita second-stage juvenile cDNA library by probing with
a 0.5kb fragment derived from fingerprinting that was more strongly expressed in
parasitic second-stage juveniles. The cDNA, named Mi-msp-1, contained an open
reading frame encoding 231 amino acids, with the first 21 amino acids being a
putative secretory signal. In Southern blot analysis the Mi-msp-1 hybridised with
genomic DNA from M. incognita, Meloidogyne arenaria, Meloidogyne javanica, but
not Meloidogyne hapla, Heterodera glycines or Caenorhabditis elegans. In Northern
blot analysis a 1kb transcript was detected in both preparasitic and parasitic
second-stage juveniles, but not in adult females of M. incognita. Comparing the
predicted amino acid sequence with protein databases revealed significant
similarity to the venom allergen antigen 5 family of proteins in hymenoptera
insects and homologues found in several other nematode species.
PMID- 10675750
TI - A molecular systematic framework for equine strongyles based on ribosomal DNA
sequence data.
AB - In this study, molecular data sets were used to address the controversies
relating to the systematics of strongyloid nematodes of equids utilising
morphological data sets. DNA sequences of the first and second internal
transcribed spacers (ITS-1 and ITS-2) of ribosomal DNA were determined for 30
species of equine strongyles and the systematic relationships reconstructed using
phenetic and phylogenetic tree-building methods. The molecular data provided
support for the hypothesis that the genera with large subglobular buccal capsules
are ancestral to those with small cylindrical buccal capsules, but did not
provide support for the current division of the subfamilies Strongylinae and
Cyathostominae or for some taxonomic groupings (i.e. generic designations of
species) within the Cyathostominea based on morphological data. Although not
entirely concordant, the current molecular data provide a systematic framework
for future studies of equine strongyles, which could be exploited in combination
with new, phylogenetically informative morphological data sets.
PMID- 10675751
TI - Inheritance of avermectin resistance in Haemonchus contortus.
AB - A larval development assay was used to compare the responses of the Chiswick
Avermectin Resistant (CAVRS) isolate of Haemonchus contortus, an avermectin
susceptible isolate (VRSG) and their crosses to avermectins. The F(1) and F(2)
generations of reciprocal crosses between CAVRS and VRSG were denoted as CAVRS
malesxVRSG females=CXV, and VRSG malesxCAVRS females=VXC. The levels of
avermectin resistance in the developing larvae of the F(1) of both CXV and VXC
were indistinguishable from that in the avermectin-resistant parent, indicating
that the resistance trait is completely dominant. Avermectin dose-response curves
for the CXV F(1) did not show a 50% mortality rate at low concentrations,
indicating that avermectin resistance is not sex-linked. This conclusion was
confirmed when adult male worms of the F(1) of the CXV mating were found to have
survived treatment of the host with 200microgkg(-1) ivermectin. This dose rate
(200microgkg(-1) ivermectin) caused a 50% reduction in the number of adult males
in the F(1) from both CXV and VXC crosses, but only a non-significant reduction
in the number of adult females in the F(1). Dose-response curves obtained for the
F(2) generations in the larval development assay indicated the presence of 25% of
avermectin-susceptible individuals, suggesting that a single major gene largely
controls the avermectin-resistance trait. This genetic analysis of avermectin
resistance in an Australian H. contortus isolate indicates that the expression of
the gene for avermectin resistance is an autosomal, complete dominant in the
larvae; however, in adults its expression is sex-influenced, with males having a
lower resistance to avermectin than females.
PMID- 10675752
TI - Enhancement of the human T cell response to culture filtrate fractions of
Mycobacterium tuberculosis by microspheres.
AB - An improved method of assessment of the human immune response against
Mycobacterium tuberculosis antigens will assist the development of new vaccines
or diagnostic reagents. In this study, we have analyzed human T cell responses to
culture filtrate fractions (CFF) of actively replicating M. tuberculosis strain
H37Rv using peripheral blood mononuclear cells from healthy PPD skin test
positive and negative individuals. Adsorption of CFF onto polystyrene
microspheres, that were approximately the size of the M. tuberculosis (bead
adsorbed antigens, BAA) significantly enhanced IFN-gamma production compared to
soluble antigens (SA) in PPD skin test positive individuals in an antigen
specific manner. Further, BAA induced activation of both CD4(+) and CD8(+) T cell
subsets. However, CD4(+) responses in general were higher and their antigenic
repertoire was wider than the CD8(+) responses. By contrast, CD8(+) responses
were strongest to the lower molecular weight BAA. When CFF were chemically
coupled to carboxyl modified microspheres (bead-coupled antigens, BCA), induction
of IFN-gamma was similar to BAA. Enhancement of T cell responses to particulate
M. tuberculosis antigens may prove useful in vaccine design strategies.
PMID- 10675753
TI - Isolation and characterization of human multiple myeloma cell enriched
populations.
AB - We developed a simple and rapid method to enrich tumor cells within bone marrow
(BM) aspirates from patients with multiple myeloma (MM). Thirty patients with a
median of 50% (8-85%) MM cells by morphology and 55% (6--85%) MM cells identified
by CD38+CD45-cell surface phenotype were studied. BM mononuclear cells (BMMCs)
were isolated by Ficoll Hypaque sedimentation and incubated with a cocktail of
mouse monoclonal antibodies (mAbs) directed against CD3 (T cells); CD11b and CD14
(monocytes); CD33 (myeloid cells), CD45 and CD45RA (leucocyte common antigen);
CD32 as well as glycophorin A. After the addition of anti-mouse Fc Ig-coated
immunomagnetic beads, mAb-bound cells were removed in a magnetic field. The
residual cell populations were enriched for MM cells, evidenced by >95% plasma
cell morphology and >95% CD38+CD45RA-cell surface phenotype. Since this method
requires only two short incubations, cell losses were minimal and the yield of MM
cells was therefore high (>95%). Viability of the MM-cell enriched fractions was
99%, and these cells were functional in assays of proliferation, cell cycle
analysis and immunoglobulin secretion. This immunomagnetic bead depletion method
therefore permits the ready isolation of homogeneous populations of patient MM
cells for use in both cellular and molecular studies.
PMID- 10675754
TI - Evaluation of a high IgE-responder mouse model of allergy to bovine beta
lactoglobulin (BLG): development of sandwich immunoassays for total and allergen
specific IgE, IgG1 and IgG2a in BLG-sensitized mice.
AB - An animal model of food allergy represents an important tool for studying the
mechanisms of induction and repression of an allergic reaction, as well as for
the development of an immunotherapy to prevent or minimize such an adverse
reaction. IgE and IgG1 (Th2 response) vs. IgG2a (Th1 response) are good markers
for the induction of an allergic response in mice. Nevertheless, while the total
serum concentrations of these isotypes are easy to measure using classical
sandwich immunoassays, this is not the case for allergen-specific isotypes. To
develop an animal model of allergy to bovine beta-lactoglobulin (BLG), we set up
quantitative assays for total and for allergen-specific IgE, IgG1 and IgG2a.
Microtiter plates coated either with anti-isotype antibodies (Abs) or with
allergen were used for Ab capture, while anti-isotype Fab' fragments coupled to
acetylcholinesterase were used for visualization. These assays of anti-BLG
specific Abs are original in two ways. First, assay calibration is performed
using anti-BLG specific mAbs, thus allowing good quantification of the different
isotypes and subclasses of serum antibodies. Second, the detection of all anti
BLG specific Abs, i.e., those recognizing both the native and denatured forms of
the protein, is achieved through indirect coating of BLG using biotin
streptavidin binding. The present assays are quantitative, specific to the
isotype (cross-reactivity <0.5%), very sensitive (detection limit in the 10 pg/ml
range), and reproducible (coefficient of variation less than 10%). Applied to the
humoral response in mice sensitized with BLG adsorbed on alum, these assays
proved to be a very useful tool for monitoring high IgE-responder mice following
BLG immunization, and for an immunotherapy directed at polarizing the immune
response.
PMID- 10675755
TI - A critical comparison of frequently used methods for the analysis of tumor
necrosis factor-alpha expression by human immune cells.
AB - A variety of methods have been developed for the measurement of tumor necrosis
factor (TNF)-alpha synthesis by immune cells. Here we have compared the results
of the most common used methods, including in vitro stimulation of whole blood or
peripheral blood mononuclear cell (PBMC) cultures with phytohaemagglutinin (PHA)
or lipopolysaccharide (LPS) and RT-PCR analysis of TNF-alpha transcription in
unstimulated PBMC. When we used EDTA treated blood samples we observed a
significant correlation between the PHA and LPS stimulated TNF-alpha responses in
whole blood or PBMC cultures. In contrast, TNF-alpha concentrations obtained from
PHA and LPS stimulated whole blood cultures from citrate-treated blood did not
show a correlation. We also found that the PHA stimulated TNF-alpha response was
significantly higher in PBMC than in whole blood cultures, whereas the highest
LPS stimulated TNF-alpha response was observed in citrate-treated blood.
Moreover, the TNF-alpha response in both, citrate and EDTA treated whole blood
cultures was significantly higher after LPS than after PHA stimulation. In
contrast, in PBMC cultures the PHA stimulated TNF-alpha response was
significantly higher than the LPS stimulated response. The results of RT-PCR
analysis revealed a significant correlation with the PHA stimulated TNF-alpha
response, both in whole blood assays and in PBMC cultures. In addition our
results demonstrate that these different methods can only be compared when the
influence of external factors such as the immediate processing of blood samples
or the use of an appropriate anticoagulant and stimulant is considered.
PMID- 10675756
TI - Development and evaluation of a direct sandwich-enzyme-linked immunosorbent assay
for the quantification of human hepatic triglyceride lipase mass in human plasma.
AB - We have developed a direct sandwich-enzyme-linked immunosorbent assay (ELISA) for
quantification of the hepatic triglyceride lipase (HTGL) immunoreactive mass in
human plasma. This direct sandwich-ELISA uses a combination of two distinct
monoclonal antibodies (MAbs), which recognize different epitopes on the HTGL
molecule: a horseradish peroxidase (HRP)-labeled anti-human HTGL MAb (2(4)F12C12)
as an enzyme-linked MAb, and an anti-human HTGL MAb (1(11)A3H3) coated on a
microtiter plate as a solid-phase MAb. Purified human post-heparin plasma (PHP)
HTGL was used as the standard material. The detection range of the sandwich-ELISA
was 40-800 ng of HTGL protein per ml of plasma. The intra- and inter-assay
coefficients of variation were less than 2.0% and 2.3%, respectively. The
recovery tests resulted in variation only between 97.7% and 103.5%. No
significant assay interference was caused by a high concentration of
triglyceride, hemoglobin, bilirubin, uric acid, or creatinine. The reliability of
the HTGL mass values obtained with the direct sandwich-ELISA was assessed by
comparison with the HTGL mass values determined by our earlier one-step sandwich
enzyme immunoassay (EIA). The two sets of values showed a highly significant
correlation (r=+0.952, n=64). Strong correlation (r=+0. 959, n=50) was also found
between the HTGL masses with the direct sandwich-ELISA and the HTGL activities
determined with a selective immunoinactivation assay. The HTGL mass
concentrations in PHP from 64 healthy subjects were 1916+/-841 ng/ml by the
direct sandwich-ELISA and 1925+/-785 ng/ml (mean+/-standard deviation (SD)) by
the one-step sandwich-EIA. The present direct sandwich-ELISA permits rapid
identification of certain HTGL abnormalities in PHP samples from patients with
hypertriglyceridemia or diseases such as hypothyroidism or renal failure, which
affect HTGL.
PMID- 10675757
TI - An ELISA method to measure total and specific human secretory IgA subclasses
based on selective degradation by IgA1-protease.
AB - We have taken advantage of the property of IgA1-proteases to selectively cleave
the human IgA1 subclass into Fabalpha and Fcalpha-J chain-secretory component
(Fcalpha-J-SC) fragments in order to design a novel ELISA method for measuring
the two secretory IgA (S-IgA) subclasses in secretions. The assay is based on the
loss of detection of S-IgA1 by a combination of peroxidase-labelled antibodies to
secretory component and Fab following IgA1-protease treatment. The specificity is
that of the protease and the sensitivity of the detection is 5 ng/ml. Moreover,
the use of purified S-IgA1 and S-IgA2 controls is not necessary. The assay has
been successfully applied to the analysis of colostral S-IgA antibodies (Abs) to
HIV-1-gp160 from HIV-1 positive women. The major subclass of colostral S-IgA
antibodies to gp160 was found to be of the alpha1 isotype but the specific
activity of anti-HIV-gp160 S-IgA2 was, however, higher than that of S-IgA1.
PMID- 10675758
TI - A simple method to quantify staphylococcal protein A in the presence of human or
animal IgG in various samples.
AB - Immunoassays designed to measure low concentrations of staphylococcal protein A
(SPA) that have been leached into antibody preparations intended for therapeutic
use are subject to differing degrees of interference. Methods established to
quantify SPA in murine antibody preparations are not accurate in the presence of
human or humanized IgG. We report the development of an enzyme-linked
immunosorbent assay (ELISA) for SPA with a detection limit of 7 pg/ml and the
optimization of a method that permits complete dissociation of SPA-immunoglobulin
complexes. This assay is a modification of our heat-mediated dissociation (HD-SD)
treatment with sodium dodecyl sulfate (SDS) and diethylenetriaminepentacetic acid
(DTPA) for total immune-complex dissociation, in which the heat treatment has
been prolonged and the diluent is characterized by increased protein content and
buffering capacity. The diluent developed contains SDS, DTPA and bovine serum
albumin dissolved in a 0.1 M phosphate buffer (pH 7.2). To validate the
efficiency of this novel method, a series of samples have been assayed, including
samples reconstituted in vitro, samples of purified antibodies, and plasma from
patients. The described method has been shown to be generally efficient in
quantitating all native and recombinant SPA in samples containing up to 50 mg/ml
of human IgG. These data demonstrate the utility of this technique in determining
SPA contamination of recombinant immunoglobulin therapeutic products.
PMID- 10675759
TI - The influence of naturally occurring heterophilic anti-immunoglobulin antibodies
on direct measurement of serum proteins using sandwich ELISAs.
AB - Sandwich ELISAs have become a widely used method for the quantitative detection
of serum proteins. However, they can be biased by a variety of interfering
substances. As reported recently, we observed false-positive levels of interferon
(IFN)-alpha and -beta in up to 27% of sera from healthy blood donors using
commercial ELISAs. We now demonstrate that two different groups of naturally
occurring heterophilic antibodies (IgG-type) are responsible for these titers.
Group I (representing 85% of positive samples) binds to the Fab region of IgG
from goat, mouse, rat, horse, and bovidae (but not rabbit). Group II (15%)
recognizes an epitope in the Fc region of mouse, horse, bovine, and rabbit (but
not goat or rat) immunoglobulins. The antibodies did not crossreact with human
IgG subclasses but contributed to false-positive IgG rheumatoid factor levels
obtained using a commercially available ELISA. To investigate the susceptibility
of assays to these artifacts, various combinations of capture and detection
antibodies have been tested. On this basis, we defined the relative risks that
standard ELISAs might be influenced by heterophilic anti-immunoglobulin
antibodies. In general, assays that use monoclonal antibodies for both capture
and detection are less susceptible than others which include at least one
polyclonal antiserum. However, only systems utilizing rabbit F(ab')(2) fragments
have been found to be immune to this interference.
PMID- 10675760
TI - The development of monoclonal human rabies virus-neutralizing antibodies as a
substitute for pooled human immune globulin in the prophylactic treatment of
rabies virus exposure.
AB - To provide a more defined and safer replacement for the human rabies immune
globulin (HRIG) from pooled serum which is currently used for treatment of
exposure to rabies virus we have developed a series of human rabies virus
specific monoclonal antibodies. Mouse-human heterohybrid myeloma cells producing
rabies virus-specific human monoclonal antibodies were prepared using B cells
obtained from volunteers recently-immunized with a commercial rabies virus
vaccine (HDCV). Cell lines producing antibody which neutralized the Evelyn
Rokitnicki-Abelseth (ERA) rabies virus strain in vitro were cloned and the
resulting monoclonal antibodies characterized for isotype, specificity against a
variety of rabies virus isolates, and neutralization capacity. The ability of the
monoclonal antibodies to neutralize a variety of rabies virus strains in vitro
correlated with their binding specificity for these viruses in an enzyme-linked
immunoadsorbant assay (ELISA). A number of these antibodies have proven suitable
for the formulation of a prophylactic human monoclonal antibody-based reagent
which would provide significant advantages to the HRIG in having defined,
reproducible specificity, lessened possibility of contamination with viral
pathogens, and consistent availability.
PMID- 10675761
TI - Loss of ELISA specificity due to biotinylation of monoclonal antibodies.
AB - A significant degree of nonspecificity was found in ELISA determinations of
soluble urokinase receptor (suPAR) in human blood plasma when biotinylated
monoclonal antibodies (Mabs) were used for the detection layer. Surface plasmon
resonance studies using both nonbiotinylated and biotinylated antibodies
demonstrated that biotinylation reduced specific binding of the antibodies to
their target antigen, suPAR. Furthermore, biotinylation produced a new
interaction with unknown human plasma protein(s), unrelated to suPAR. Nonspecific
interaction with plasma protein(s) was also observed after biotinylation of a Mab
having no specific target antigen in human plasma and, in both cases, the level
of nonspecific interaction was directly related to the degree of antibody
biotinylation. These results reinforce earlier observations that biotinylation of
antibodies can reduce the affinity of antibodies, but also indicate that, in
addition, biotinylation can reduce the specificity of immunoassays for plasma
proteins.
PMID- 10675762
TI - Direct single-step surface plasmon resonance analysis of interactions between
small peptides and immobilized monoclonal antibodies.
AB - Surface plasmon resonance (SPR) methods have been optimized to permit direct
kinetic analysis of the antigenic peptide analytes interacting with immobilized
monoclonal antibodies (mAbs). High reproducibility and a significant correlation
between SPR and previous ELISA data on the same set of antibodies and peptides
were observed. The kinetic data obtained provide further insight into the
structure of the main antigenic site of foot-and-mouth disease virus (FMDV).
PMID- 10675763
TI - Improved generation of catalytic antibodies by MRL/MPJ-lpr/lpr autoimmune mice.
AB - To compare the abilities of different strains of mice to elicit catalytic
antibodies (Abs), we determined the occurrence of esterolytic Abs in BALB/c
(normal strain) and MRL/MPJ-lpr/lpr (MRL/lpr, autoimmune) mice after immunization
with the transition state analog (TSA) 1. Hybridoma supernatants elicited against
TSA 1 were screened by ELISA for binding to the BSA-conjugated TSA 1 (=3b), and
then screened for binding to the BSA-linked short TSA 2 (=4). We obtained eight
times more positives from MRL/lpr mice than from BALB/c mice by these screening
steps. The monoclonal antibodies (mAbs) obtained here were examined for binding
and catalytic activity. Fifteen of 25 mAbs from MRL/lpr had esterolytic activity,
compared with only two of 21 mAbs from BALB/c. These results demonstrated that
the occurrence of catalytic Abs was much higher in MRL/lpr mice than in BALB/c
mice, which is in good agreement with the previous report by Tawfik et al.
[Tawfik, D.S., Chap, R., Green, B.S., Sela, M., Eshhar, Z., 1995. Proc. Natl.
Acad. Sci. U.S.A. 92, 2145-2149] using a different kind of TSA. Thus, these
studies strongly suggest that using the appropriate strain can be a key factor in
the efficient production of catalytic Abs. Furthermore, these mAbs were
characterized to elucidate the mechanism of strain difference, and determine
whether MRL/lpr mice can be used with other TSAs for the efficient production of
catalytic Abs.
PMID- 10675764
TI - Measurement of lymphocyte subset proliferation by three-color immunofluorescence
and DNA flow cytometry.
AB - We developed a method for simultaneous flow cytometric analysis of three-color
immunofluorescence and DNA content. We show here that staining with 7-amino
actinomycin D (7-AAD) at 10 microg/ml using a phosphate-citrate buffer at low pH
containing saponin for cell membrane permeabilization yields good resolution DNA
histograms with low coefficients of variation. Furthermore, light scatter
properties of cells are preserved after permeabilization; this permits gating on
cell populations that differ in scatter signals on the flow cytometer. Because of
the low pH of the phosphate-citrate staining buffer, Alexa488, a pH-independent
green-fluorescent fluorochrome is used instead of fluorescein-isothiocyanate
(FITC) for cell surface staining in combination with phycoerythrin (PE) and with
allophycocyanin (APC) which are both pH insensitive. Removal of 7-AAD after
staining and replacing it with non-fluorescent actinomycin D (AD) retains DNA
staining and allows detection of Alexa488, PE and APC cell surface
immunofluorescence without interference from fluorescent 7-AAD in solution for
clear identification of cell subpopulations even after prolonged stimulation in
culture. Thus, using a four-color benchtop flow cytometer, measurement of
Alexa488, PE and APC three-color immunofluorescence can be combined with 7-AAD
DNA content analysis. Furthermore, we demonstrate that sample storage overnight
without fixation for later analysis on the flow cytometer is possible without
compromising results. Application of the method to the assessment of the
differential proliferative responses of lymphocyte subsets of human peripheral
blood mononuclear cells (PBMC) that were costimulated with CD3 and with CD28.2 is
presented.
PMID- 10675765
TI - Differential expression of S100B and S100A6(1) in the human fetal and aged
cerebral cortex.
AB - S100B and S100A6 (calcylin) are two members of the S100 Ca(2+)-binding protein
family and have been localized in the mammalian nervous system. However,
information on their distribution in the human nervous system, especially in the
developing human fetal brain, is scarce. In the present study, an
immunocytochemical method was used to examine the spatio-temporal protein
expression patterns of S100B and S100A6 in normal human fetal hippocampus,
entorhinal cortex and occipital cortex. Normal aged adult human brain specimens
were also included for comparison. From week 15 onwards, an increase with
advancing gestation age in both the number and staining intensity of S100B
positive, astrocyte-like cells was found in the pyramidal layer of the
hippocampus, while both the molecular and polymorphic layers showed similar S100B
immunoreactivities at all stages examined. A decrease in the immunoreactivities
was found in the molecular layer of the aged adult hippocampus while other layers
exhibited immunoreactivities similar to those of the late fetus. At week 15, the
molecular, pyramidal and ganglionic/multiform layers of the entorhinal cortex
also showed positive S100B immunoreactivities which were maintained throughout
the rest of the gestation and in adult specimens. In the occipital cortex, the
numbers of positive cells for all layers were about twofold higher than those
found in the hippocampus and entorhinal cortex, and immunoreactivities detected
in the granular layer increased from week 21, reaching a plateau at around week
27. S100B positive fibers were also found at week 30 but were not observed in
aged adult specimens. S100A6 positive cells were on the whole fewer in number
than those of S100B in the brain regions examined. The S100A6 immunoreactivities
which were localized in some pyramidal neuron-like and some glial-like cells of
the pyramidal and molecular layers of the hippocampus increased by midgestation
and became weak in the late fetus and in aged adult specimens. Weakly stained
S100A6 positive cells were also observed in the entorhinal cortex throughout the
gestation and in aged adult cortex. S100A6 immunoreactivities were weak in the
fetal occipital cortex. They were also localized in the glial-like cells of the
aged adult occipital cortex. The differential spatio-temporal expression of S100B
and S100A6 proteins suggests that the proteins play different roles in different
brain regions during development and in adulthood.
PMID- 10675766
TI - Effects of hindlimb unloading on neuromuscular development of neonatal rats.
AB - We hypothesized that hindlimb suspension unloading of 8-day-old neonatal rats
would disrupt the normal development of muscle fiber types and the motor
innervation of the antigravity (weightbearing) soleus muscles but not extensor
digitorum longus (EDL) muscles. Five rats were suspended 4.5 h and returned 1.5 h
to the dam for nursing on a 24 h cycle for 9 days. To control for isolation from
the dam, the remaining five littermates were removed on the same schedule but not
suspended. Another litter of 10 rats housed in the same room provided a vivarium
control. Fibers were typed by myofibrillar ATPase histochemistry and
immunostaining for embryonic, slow, fast IIA and fast IIB isomyosins. The
percentage of multiple innervation and the complexity of singly-innervated motor
terminal endings were assessed in silver/cholinesterase stained sections. Unique
to the soleus, unloading accelerated production of fast IIA myosin, delayed
expression of slow myosin and retarded increases in standardized muscle weight
and fiber size. Loss of multiple innervation was not delayed. However, fewer than
normal motor nerve endings achieved complexity. Suspended rats continued unloaded
hindlimb movements. These findings suggest that motor neurons resolve multiple
innervation through nerve impulse activity, whereas the postsynaptic element
(muscle fiber) controls endplate size, which regulates motor terminal
arborization. Unexpectedly, in the EDL of unloaded rats, transition from
embryonic to fast myosin expression was retarded. Suspension-related foot drop,
which stretches and chronically loads EDL, may have prevented fast fiber
differentiation. These results demonstrate that neuromuscular development of both
weightbearing and non-weightbearing muscles in rats is dependent upon and
modulated by hindlimb loading.
PMID- 10675767
TI - Effects of neonatal rat Borna disease virus (BDV) infection on the postnatal
development of the brain monoaminergic systems.
AB - Effects of neonatal Borna disease virus infection (BDV) on the postnatal
development of brain monoaminergic systems in rats were studied. Tissue content
of norepinephrine (NE), dopamine (DA) and its metabolite, 3,4-dihydroxyphenol
acetic acid (DOPAC), and serotonin (5-HT) and its metabolite, 5-hydroxyindole-3
acetic acid (5-HIAA) were assayed by means of HPLC-EC in frontal cortex,
cerebellum, hippocampus, hypothalamus and striatum of neonatally BDV-infected and
sham-inoculated male Lewis rats of 8, 14, 21, 60 and 90 days of age. Both NE and
5-HT concentrations were significantly affected by neonatal BDV infection. The
cortical and cerebellar levels of NE and 5-HT were significantly greater in BDV
infected rats than control animals at postnatal days (PND) 60 and 90. Tissue
content of NE in hippocampus was unaffected. In hippocampus, neonatally BDV
infected rats had lower 5-HT levels at PND 8 and significantly elevated levels at
PND 21 and onwards. Neither striatal levels of 5-HT nor hypothalamic levels of 5
HT and NE were affected by neonatal BDV infection, suggesting that the monoamine
systems in the prenatally maturing brain regions are less sensitive to effects of
neonatal viral infection. 5-HIAA/5-HT ratio was not altered in BDV-infected rats
indicating no changes in the 5-HT turnover in the brain regions damaged by the
virus. Neither DA nor DOPAC/DA ratio was affected by neonatal BDV infection in
any of the brain regions examined. The present data demonstrate significant and
specific alterations in monoaminergic systems in neonatally BDV-infected rats.
This pattern of changes is consistent with the previously reported behavioral
abnormalities resulting from neonatal BDV infection.
PMID- 10675768
TI - Gene expressions during the development and sexual differentiation of the
olfactory bulb in rats.
AB - In this study, expressions of cell-cycle-related genes: p53, retinoblastoma (Rb),
p21, bcl-2(alpha), bcl-2(beta); protooncogene c-ski; glial cell marker protein
gene S100beta; neurotransmitter gene, substance P and sexual-differentiation
related genes, androgen receptor (AR) and estrogen receptor beta (ER(beta)), are
studied in the olfactory bulb of groups of both six female and six male rats at
the ages of 3, 10, 20 and 40 days. Expressions of housekeeping genes such as beta
actin, cyclophilin and proliferating cell nuclear antigens (PCNA) are determined
using reverse transcription polymerase chain reaction (RT-PCR) for the correction
of unequal amount of cDNA added into the samples. Using labeled 32P-dCTP and
Phosphorimager technology, relative abundance of radioactivities of the PCR
products is obtained by dividing the radioactivity of each individual sample by
the corresponding radioactivities of different housekeeping genes. Data evaluated
by Two-way ANOVA indicate that only the bcl-2(alpha) gene expression is affected
significantly by age, sex and their interactions no matter which of the three
housekeeping genes is used for correction. When beta-actin was used for
corrections, effects of age but not sex were found in the expressions of p53, Rb,
p21, AR, ER(beta), substance P and S100beta genes, but not in bcl-2(beta), c-ski,
cyclophilin and PCNA genes. While cyclophilin was used for corrections, only the
p53, Rb, AR, ER(beta), substance P and S100beta but not the bcl-2(beta), p21, c
ski, PCNA and beta-actin genes are affected by age. They are all not influenced
by sex of the animals. Only the AR, ER(beta) and S100beta genes are age-dependent
when PCNA was used for the correction. The other gene expressions are not altered
by sex, while the interactions of age and sex were found to be significantly
affecting the bcl-2(beta) gene expression. Conclusively, developmental changes of
the p53, Rb, AR, ER(beta), substance P and S100beta genes expressions are quite
evidenced while only the bcl-2(alpha) gene seems to change significantly during
the sexual differentiation of olfactory bulb in rats.
PMID- 10675769
TI - Comparative immunocytochemical study of FMRFamide neuronal system in the brain of
Danio rerio and Acipenser ruthenus during development.
AB - The distribution of FMRFamide-like immunoreactive (ir) neurons and fibers was
investigated in the central nervous system of developing zebrafish and juvenile
sturgeon (sterlet). Adult zebrafish was also studied. In zebrafish embryos
FMRFamide-ir elements first appeared 30 h post-fertilization (PF). Ir somata were
located in the olfactory placode and in the ventral diencephalon. FMRFamide-ir
fibers originating from diencephalic neurons were found in the ventral
telencephalon and in ventral portions of the brainstem. At 48 h PF, the ir
perikarya in the olfactory placode displayed increased immunoreactivity and
stained fibers emerged from the somata. At 60 h PF, bilaterally, clusters of
FMRFamide-ir neurons were found along the rostro-caudal axis of the brain, from
the olfactory placode to rostral regions of the ventro-lateral telencephalon. At
60 h PF, numerous ir fibers appeared in the dorsal telencephalon, optic lobes,
optic nerves, and retina. Except for ir fibers in the hypophysis at the age of 72
h PF, and a few ir cells in the nucleus olfacto-retinalis (NOR) at the age of 2
months PF, no major re-organization was noted in subsequent ontogenetic stages.
The number of stained NOR neurons increased markedly in sexually mature
zebrafish. In adult zebrafish, other ir neurons were located in the dorsal zones
of the periventricular hypothalamus and in components of the nervus terminalis.
We are inclined to believe that neurons expressing FMRFamide originate in the
olfactory placode and in the ventricular ependyma in the hypothalamus. On the
same grounds, a dual origin of FMRFamide-ir neurons is inferred in the sturgeon,
an ancestral bony fish: prior to the observation of ir cells in the nasal area
and in the telencephalon stained neurons were noted in circumventricular
hypothalamic regions.
PMID- 10675770
TI - Glial-derived neurotrophic factor (GDNF) prevents ethanol-induced apoptosis and
JUN kinase phosphorylation.
AB - Ethanol exposure during neural development leads to substantial neuronal loss in
multiple brain regions. Our previous research indicated that exogenous glial
derived neurotrophic factor (GDNF) attenuated ethanol-induced cerebellar Purkinje
cell loss. Additionally, ethanol decreased GDNF release suggesting that ethanol
disrupts GDNF-signaling pathways. The present experiments utilized a homogeneous
GDNF-responsive neuroblastoma cell line (SK-N-SH) to test the hypothesis that
exogenous GDNF could attenuate ethanol-induced cell loss by suppressing cytotoxic
signaling pathways and cell suicide. We measured two independently regulated
markers of apoptosis, DNA fragmentation and the externalization of
phosphatidylserine to the outer cell membrane leaflet. Ethanol induced a dose
related increase in both apoptosis and necrosis. Lower concentrations of ethanol
(34 and 68 mM) specifically increased DNA fragmentation, while all concentrations
(up to 137 mM) increased phosphatidylserine translocation, suggesting that
ethanol induction of apoptosis is not a unitary process. Furthermore, only higher
concentrations of ethanol (103 and 137 mM) induced necrosis. Additionally,
ethanol specifically induced phosphorylation of c-jun N-terminal-kinase (JNK), a
mitogen-activated protein (MAP) kinase selectively associated with apoptosis. In
contrast, ethanol did not alter the phosphorylation of another MAP kinase, the
extracellular signal-regulated kinases (ERK) that mediate cell survival. Thus,
ethanol activated specific intracellular cell death-associated pathways and
induced cell death. GDNF, in turn, prevented both ethanol-induced apoptosis and
the activation of the death-associated JNK cascade. Therefore, GDNF may regulate
multiple pathways to prevent ethanol-induced cell loss.
PMID- 10675771
TI - Developmental expression of urinary bladder neurotrophic factor mRNA and protein
in the neonatal rat.
AB - These studies were performed to determine the developmental expression pattern of
neurotrophic factor (NTF: nerve growth factor (betaNGF), brain-derived
neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), ciliary
neurotrophic factor (CNTF), neurotrophin-3 (NT-3) and NT-4 mRNA and NGF, NT-3 and
NT-4 protein in the urinary bladder of the postnatal Wistar rat. It was
hypothesized that NTFs may contribute to the development of the spinobulbospinal
micturition reflex that represents the adult micturition pattern. Changes in NTF
mRNA or protein expression in the urinary bladder at the time of development of
the mature micturition reflex (postnatal days (P) 16-18) may suggest an
involvement of target-derived NTFs in this maturation process. Developmental
ages, prior to (P5, P10, P15) or following (P20, P30, adult P90) the development
of the spinobulbospinal micturition reflex were selected and the urinary bladder
was analyzed for levels of neurotrophic factor mRNA or protein. Results from
ribonuclease protection assays demonstrated a similar developmental pattern among
each neurotrophic factor examined. Neurotrophic factor mRNA levels increased by
P10 and reach a maximum by P15. Subsequently, NTF mRNA levels declined to adult
levels that were less than the earliest postnatal time examined (P5). NTF mRNA
expression was significantly (p=0.05-0.001) greater at P10, P15, P20 and P40
(NT-4 mRNA) compared to adult levels for each NTF examined except GDNF mRNA. In
general, NGF, NT-3 and NT-4 urinary bladder protein levels in early postnatal
development, as determined by ELISA, were similar when compared to the
corresponding mRNA expression. Differences in the correlation between NT-3 and NT
4 mRNA and protein expression were demonstrated in the adult urinary bladder
where significantly (p=0. 001) greater levels of protein were revealed despite
relatively low abundance of NT-3 and NT-4 mRNA. The developmental expression
pattern (maximum expression at the second to third postnatal week) of NTFs in the
urinary bladder is consistent with a potential role in the development of the
spinobulbospinal reflex. Relatively high expression of NT-3 and NT-4 protein in
the adult urinary bladder suggests a potential importance of these factors in the
adult lower urinary tract.
PMID- 10675772
TI - Developmental expression of Bcl-2 protein in human cortex.
AB - Apoptosis is essential for normal human neurodevelopment and is increasingly
recognized for its role in various neurodegenerative diseases such as Alzheimer's
and Parkinson's diseases. Bcl-2 is a 26 kDa membrane-associated protein known to
protect neurons against apoptosis. Interestingly, Bcl-2 protein levels are
altered in certain neurodegenerative disorders that reveal increased apoptosis.
However, little is known about the normal expression of Bcl-2 protein in human
brain. Bcl-2 protein levels were determined by ELISA and semiquantitative Western
Blotting in the frontal cortex of 20 human post-mortem brains, separated into
three groups: six infants (age: 0.83+/-1.0 years, mean+/-S.D.), five adolescents
(age: 17.4+/-1.7 years), and nine adults (age: 41.0+/-9.6 years). All subjects
died of non-CNS related illness and had no history of psychiatric illness. Bcl-2
increased significantly across the age groups in the ELISA (p=0.0058) and the
Western Blot (p=0.002) experiments. The ELISA demonstrated significant
differences in Bcl-2 levels between infant and adolescent cortex (p<0.05), and
between infant and adult cortex (p<0.01) using a post-hoc Tukey's multiple
comparison test. The Western blots demonstrated a similar significant increase in
Bcl-2 between infant and adult cortex (p<0. 01). A secondary analysis showed
significant correlation between individual ages and Bcl-2 levels (r(2)=0.4933,
p=0.0006). This study demonstrates that Bcl-2 protein expression in human cortex
is developmentally regulated and supports the hypothesis that Bcl-2 is involved
in normal aging.
PMID- 10675773
TI - Interferon beta-1a prevents the effects of lipopolysaccharide on embryonic brain
microvessels.
AB - By means of light and electron microscopy we have studied the effect of
interferon beta-1a (IFNbeta-1a) in the optic tecta of 20-day-old chick embryos
under normal conditions and after exposure to lipopolysaccharide (LPS) which
mimics the blood-brain barrier (BBB) disruption in meningoencephalitis. Optic
tecta were examined for: (i) ultrastructure by means of transmission electron
microscopy; (ii) the immunohistochemical localization of HT7 antigen, a specific
marker of differentiation of the brain microvessels; (iii) the brain microvessel
permeability, by means of horseradish peroxidase (HRP) tracer; (iv) the
expression of microvessel glycoconjugates, by means of lectin histochemistry,
using Ricinus communis agglutinin-I (RCA-I), specific for beta-D-galactosyl
moieties and Wheat Germ agglutinin (WGA) specific for sialyl and N
acetylglucosaminyl moieties. A morphometric evaluation of brain microvessel
permeability and of glycoconjugate expression was also performed. In control- and
in IFNbeta-1a-treated embryos, HRP was confined to the vessel lumina which were
sealed by the interendothelial tight junctions. RCA-I binding sites were
recognizable both in the basal membranes and in the tight junctions, while WGA
sites were present on the luminal side of the endothelial cells. HRP was blocked
in the vessels lumina by the interendothelial tight junctions. After LPS
treatment, HRP showed an extravascular localization and the labeling of
microvessels by anti-HT7 antibodies disappeared. RCA-I binding was only found
ultrastructurally and appeared as irregularly clustered gold particles, in the
cleft of damaged tight junctions, but were no longer detectable in the
endothelial basement membranes. After pretreatment of LPS-treated embryos with
IFNbeta-1a, the vessel permeability to HRP strongly decreased and the vessels
showed the normal pattern of HT7 protein and of the RCA-I binding sites. These
results indicate that the changes induced by LPS in the endothelial cells are
prevented by IFNbeta-1a.
PMID- 10675774
TI - Alterations in the distribution of stimulus-evoked c-fos in the spinal cord after
neonatal peripheral nerve injury in the rat.
AB - Neonatal peripheral nerve injury results in a significant rearrangement of the
central terminals of surviving axotomized and adjacent intact primary afferents
in the dorsal horn of the spinal cord. This study investigates the ability of
these afferents to make functional contacts with dorsal horn cells, using c-fos
expression as a marker of synaptic activation. Graded electrical stimulation at A
or C-fiber strength of either the neonatally axotomized sciatic nerve or the
adjacent uninjured saphenous nerve was performed in adult rats. Stimulation of
the contralateral uninjured nerve served as a control. Quantitative examination
of the number and distribution of c-fos-labeled cells in the spinal cord laminae
was performed. Electrical stimulation of the previously axotomized sciatic nerve
at A-fiber intensity resulted in many labeled profiles in laminae I-V of the
lumbar spinal cord on the experimental as compared to the contralateral side.
Electrical stimulation of uninjured saphenous nerve or saphenous-nerve-innervated
skin (using pin electrodes) at A-fiber intensity did not evoke c-fos. Stimulation
of the saphenous nerve at C-fiber intensity, however, resulted in a significant
increase in the number and distribution of c-fos-labeled profiles in laminae I-V
on the experimental side as compared to the contralateral control side. The
results show that the distribution of c-fos-expressing cells after neonatal nerve
injury is compatible with the previously demonstrated distribution of sprouting
of primary afferents belonging to an uninjured nerve adjacent to an injured
nerve, and that the surviving axotomized afferents are capable of transmitting
signals to postsynaptic cells. These findings indicate that Abeta afferent
stimulation of injured but not uninjured afferents elicits c-fos expression in
postsynaptic cells. This may reflect an injury-induced maintenance of a normal
developmental process whereby Abeta stimulation elicits c-fos in dorsal horn
neurons.
PMID- 10675775
TI - Age-associated changes in the densities of presynaptic monoamine transporters in
different regions of the rat brain from early juvenile life to late adulthood.
AB - The binding parameters of highly selective ligands of serotonin (5-HT)
transporters ([3H]paroxetine), noradrenaline (NE) transporters ([3H]nisoxetine),
and of dopamine (DA) transporters ([3H]GBR-12935) were determined on membrane
preparations from frontal cortex, striatum, midbrain and brain stem of Wistar
rats on postnatal days 25, 50, 90 and 240, i.e., from the time of weaning till
late adulthood. No age-dependent alterations in the affinity-parameters (K(D)
values) of all three monoamine transporters were observed. Age-associated changes
in B(max)-values of the binding of all three specific ligands were most
pronounced in the phylogenetically younger, late maturing brain regions (frontal
cortex, striatum). Most likely, these changes reflect age-related changes in 5
HT, NE and DA-innervation densities. In the frontal cortex, 5-HT-transporter
density increased steadily from weaning (day 25) till late adulthood, whereas the
density of NE-transporters was highest at weaning, declined till puberty (day 50)
and remained at this level until old age. DA-transporter density in the frontal
cortex was not reliably measurable by [3H]GBR-binding assays. In the striatum, DA
transporter density increased till puberty and declined thereafter considerably
and steadily to about one-fourth of the pubertal values at old age. No such age
associated changes in DA-transporter density were seen in the midbrain. Densities
of 5-HT and NE remained at the level reached already at weaning until old age in
the striatum, midbrain and brain stem. These findings provide the first
comprehensive description of the normally occurring changes in the densities of
all three presynaptically located monoamine transporters in the rat brain
throughout the life span from weaning to late adulthood.
PMID- 10675776
TI - Two secreted retinal factors regulate different stages of development of the
outer blood-retinal barrier.
AB - The retinal pigment epithelium (RPE) lies at the interface between the neural
retina and the choriocapillaries where it forms a blood-retinal barrier. Like
endothelial regions of the blood-brain barrier, the development of the RPE
barrier is a gradual, multistep process. A culture model of chick RPE was used to
study this development. The permeability of the tight junctions that limit
diffusion between neighboring RPE cells was measured as the transepithelial
electrical resistance (TER). Embryonic day 14 (E14) retinas were used to make a
conditioned medium that lowered the permeability of cultured RPE. The TER of
cultures prepared from E14 RPE was twice that of E7 RPE. In each culture, retinal
conditioned medium increases the TER 2-2.5 fold. The active factors of
conditioned medium that affected each culture had different physical properties.
The factor that affected E7 was protease-resistant with a Mr<10 kDa, but the
factor that affected E14 appeared to be a protein of approximately 49 kDa. Unlike
the effect of astrocyte conditioned medium on endothelia, retinal conditioned
medium did not act synergistically with cAMP. These data indicate that the chick
retina, which lacks astrocytes, uses different diffusible factors to regulate
different stages of tight junction development.
PMID- 10675777
TI - Expression of mu-opioid receptor mRNA in the medial preoptic area of juvenile
rats.
AB - Previous studies indicate that the latency to initiate parental behavior in both
male and female rats increases with age; weanling (21 days old) rats display
parental behavior 0-2 days after exposure to newborn pups, while older juveniles
(30 days old) require 5-6 days of pup exposure before they express the behavior.
Furthermore, activation of mu-opioid receptors inhibits parental behavior in
juvenile and adult rats. We hypothesized that the age-related increase in
behavioral latency could be modulated by the induction of mu-receptor expression
in the medial preoptic area (MPOA), a region in which mu-receptors regulate
parental behavior. In situ hybridization histochemistry was used to measure mu
receptor mRNA expression in the MPOA of male and female Sprague-Dawley rats that
were 21, 24, 27, 30, or 33 days old. Using autoradiographic film analysis, we
observed that neurons within part of the MPOA expressed very dense mu-receptor
mRNA. Comparison of mRNA distribution with histological boundaries indicated that
neurons within the medial preoptic nucleus (MPN), excluding the central part,
exhibited the highest density of mu-receptor mRNA within the MPOA. High densities
of mu-receptor mRNA extended dorsolaterally and caudally from the MPN toward the
bed nucleus of the stria terminalis. MPN mu-receptor mRNA expression was not
altered with age and no sex difference was observed. The dense presence of mu
receptor mRNA in the MPN suggests that ample substrate exists on which mu
receptor ligands could modulate the latency to begin parental behavior in
juvenile rats, but such behavioral expression apparently is not mediated by a
change in mu-receptor mRNA production.
PMID- 10675778
TI - Directional specificity and patterning of sensory axons in trigeminal ganglion
whisker pad cocultures.
AB - In the rodent trigeminal pathway, trigeminal axons invade the developing whisker
pad from a caudal to rostral direction. We investigated directional specificity
of embryonic day (E) 15 rat trigeminal axons within this peripheral target field
using explant cocultures. E15 trigeminal axons readily grow into the same age
whisker pad explants and form follicle-related patterns along a caudal to rostral
direction. They also can grow into this target from its lateral aspects. In
contrast, they are unable to invade the whisker pad from the rostral (nasal)
pole. We did not find any correlation between the distribution of extracellular
matrix molecules and trigeminal axon growth preferences. We also examined age
related changes in trigeminal axon responsiveness to directional cues. E19
trigeminal axons readily grew into E15 whisker pad explants from either the
caudal or the rostral pole. These results suggest the presence of growth
permissive and repulsive cues that guide sensory axons in the whisker pad.
Furthermore, trigeminal axons lose their responsiveness to growth inhibitory cues
at later stages of development.
PMID- 10675779
TI - Age-specific effects of noradrenergic alpha-2 agonist clonidine on the
development of amygdaloid kindling in developing rats.
AB - The effects of clonidine on the development of amygdaloid kindling were studied
in rats of various ages (14, 21, 28 and 70 postnatal days). Administration of
clonidine (0.2, 0.5 mg/kg i.p.) caused a significant retardation of kindling
development in the 28-day-old rats as well as in the adult rats, whereas, in the
14-day-old rats, the development of kindling was significantly facilitated by
clonidine. No significant effect of clonidine was observed in the 21-day-old
rats. These results indicate that in rats the effects of clonidine on the
development of amygdaloid kindling vary during development.
PMID- 10675781
TI - Endogenously generated spontaneous spiking activities recorded from postnatal
spiral ganglion neurons in vitro.
AB - Spontaneous spiking activities in the nervous system play an important role in
the neuronal development and the coding of sensory information. Such firings
could be initiated by transmitter leaked from the first-order sensory receptors
or as a result of the internal operation of voltage-dependent ion channels
intrinsic to the neuron. We recorded endogenously-generated spontaneous action
potentials (APs) from postnatal spiral ganglion (SG) neurons of mouse in vitro.
SG neurons in cultures displayed statistically stable spontaneous firings with no
obvious bursting, rhythmic spiking and long silent gaps for as long as the
recording configuration could be maintained. Average firing rates ranged from
less than 1 to over 10 spikes/s, with most cells fired around 4 spikes/s.
Interpulse interval histograms were remarkably similar to those recorded in vivo
from the auditory nerve, with characteristics of a Poisson-like distribution.
Resting membrane potential greatly altered the AP width and the rate of
spontaneous firings. Spontaneous firing rates were also found to be controlled by
the availability of the Shaw-like potassium channels. In contrast, matured SG
neurons did not display any spontaneous APs, probably due to a large increase in
the expression of the whole-cell potassium currents in comparison to their
postnatal counterparts. This study provided the first direct evidence that
postnatal SG neurons were capable of generating spontaneous APs independent of
inputs from hair cells. Intracellular mechanisms for generating the spontaneous
random spikes and the possible roles of such spontaneous activities in the
postnatal development of SG neurons are discussed.
PMID- 10675780
TI - Utrophin may be a precursor of dystrophin during skeletal muscle development.
AB - Expression patterns of utrophin were investigated and compared to those of
dystrophin and associated proteins in skeletal muscle of rat embryos from E12 to
E21 by immunohistochemistry. Utrophin was readily detected from E12 on, earlier
than full-length dystrophin on E14. A shorter dystrophin isoform was observed
from E12 to E16. The level of utrophin reached a maximum on E16-17 and then
declined while that of dystrophin increased after E17. A complementary
distribution of these two molecules was observed on E18. Beta-dystroglycan
appeared as early as utrophin. Sarcoglycans, appearing from E14 on, were anchored
first by utrophin and then by dystrophin. These results elucidate the
chronological order of expression of the dytrophin/utrophin protein complex and
indicate that this protein complex is originally stabilized by utrophin. This
study supports our hypothesis that utrophin might be a developmental precursor of
dystrophin.
PMID- 10675783
TI - Biological Monitoring of Pesticide Exposure: a review. Introduction.
AB - Pesticides are used worldwide in agriculture, industry, public health and for
domestic applications: as a consequence, a great part of the population may be
exposed to these compounds. In spite of this extensive use, knowledge on the
health risks associated with prolonged exposure is rather poor, and major
uncertainties still exist. Epidemiological observations in man have so far
produced little conclusive information, mainly because of weaknesses in exposure
assessment. Therefore, information on the type and levels of exposure is
fundamental in order to better understand and characterize risk to human health.
Exposure assessment can be carried out via measurement of environmental
concentrations, as well as via determination of the chemical or its metabolites
in body tissues (biological monitoring). Besides indices of internal dose,
biological monitoring also includes measurements of early effects attributable to
interaction between the chemical agent and the human body. Biological monitoring
has the advantage, over environmental monitoring, of determining the dose
actually absorbed via any possible route: differences in absorption can be taken
into account. whether they are due to biological variability or to use of
protective equipment. When, in some cases, a combination of occupational and non
occupational exposure occurs, this also can be taken into consideration by
biological monitoring. Few reference documents have been published on biological
monitoring of pesticides. For this reason, the Office of Occupational Health of
the World Health Organization gave ICPS a mandate to prepare a monograph
specifically addressed to reviewing methods for biological monitoring of
pesticide exposure. This review is based on more than 300 studies published over
the period 1980-1999. For the most representative chemical classes, the available
biological exposure indices are reported. Both indices of internal dose and. when
available, of early effects are discussed. The reported tests were used to
monitor exposure of pesticide applicators in agriculture and public health,
manufacturing and formulating workers. subjects poisoned after accidental
exposure or attempted suicide, volunteers involved in pharmacokinetic studies, as
well as sub-groups of the general population exposed to environmentally
persistent pesticides. Single chapters deal with organophosphorus insecticides,
carbamate pesticides, dithiocarbamates, phenoxyacids, quaternary ammonium
compounds. coumarin rodenticides, synthetic pyrethroids, organochlorine
pesticides, chlorotriazines, and pentachlorophenol.
PMID- 10675782
TI - Demarcation of early mammalian cortical development by differential expression of
fringe genes.
AB - Fringe has originally been found in Drosophila as a gene encoding a putative
secreted protein which regulates the sensitivity of Notch signaling pathway to
different ligands. We show that three members of murine fringe gene family,
Lunatic fringe (L-fng), Manic fringe (M-fng) and Radical fringe (R-fng), show
related patterns of expression in the developing cerebral wall. L-fng is
expressed in immature cells in the ventricular zone. M-fng is upregulated
transiently in maturing neurons when they leave the ventricular zone (VZ). R-fng
is upregulated in more mature neurons when they enter the preplate and cortical
plate. These patterns suggest that the transition from immature to mature neurons
involves sequential changes in the member of fringe family genes expressed. More
detailed expression analyses of fringe genes and immunohistochemistry for neuron
specific class III beta-tubulin suggest a mode of neurogenesis which might
underlie the histogenesis of the cerebral cortex. A proliferative population
situated outside of the VZ is defined as M-fng-positive/BrdU-positive cells,
which constitutes about 10-20% of the total S-phase cells in the cerebral wall of
embryonic day 10.5-12.5. We found that M-fng is expressed in mitotic figures
outside the VZ and some of them react with the antibody against class III beta
tubulin. These observations suggest that a significant number of proliferative
cells exist outside the VZ, which supply neurons during early cortical
development.
PMID- 10675784
TI - Dihydropyridine-sensitive calcium currents in bipolar cells of salamander retina
are inhibited by reductions in extracellular chloride.
AB - Dihydropyridine-sensitive calcium currents (I(Ca)) in photoreceptors are unusual
in that they can be inhibited by reductions in extracellular chloride. The
present study examined whether I(Ca) in retinal bipolar cells, which as in
photoreceptors mediates sustained neurotransmission, is also inhibited by
reductions in chloride. Nystatin-perforated patch, whole cell recordings were
obtained from bipolar cells in a retinal slice preparation of larval tiger
salamander. In the presence of Ba(2+), voltage steps above -40 mV evoked
sustained inward currents, which were enhanced by the dihydropyridine, (
)BayK8644, and inhibited by nisoldipine. Similar to photoreceptors, replacing Cl(
) with gluconate or CH(3)SO(4) inhibited bipolar cell I(Ca) and produced a
negative shift in the current/voltage relationship. Thus, sensitivity to Cl(-)
may be a more general property of L-type Ca(2+) channel subtypes that mediate
sustained neurotransmission.
PMID- 10675785
TI - Partial cDNAs encoding G-protein alpha subunits in the rat vestibular periphery.
AB - To begin understanding what G-proteins are involved in signal transduction in the
vestibular periphery, the expression of Galpha subunits in rat primary afferent
neurons (Scarpa's ganglia) and end-organs was studied. Reverse transcription
polymerase chain reaction (RT-PCR) with degenerate primers corresponding to two
conserved regions of the Galpha protein coding sequence produced partial cDNAs
encoding two distinct forms of Galpha(s) subunit (Galpha(s2) and anove)
Galpha(s2) subunit,GenBank accession number AF1841510); and two forms of
Galpha(i2) subunits. A novel truncated form of Galpha(i2) (designated
Galpha(i2(vest)),Gen Bank accession number AF189020) was detected in the
vestibular periphery. Galpha(i2(vest)) was also expressed in rat cerebellum and
heart. The possible role of the identified Galpha protein cDNAs in the function
of the vestibular periphery is discussed.
PMID- 10675786
TI - Chronic methylphenidate treatment enhances water maze performance following
traumatic brain injury in rats.
AB - Methylphenidate (MPH), a central nervous system stimulant with dopaminergic
activity, facilitates neurobehavioral outcome following cortical suction ablation
injury, but its potential efficacy following experimental traumatic brain injury
(TBI) is unknown. Thus, beginning 24 h after controlled cortical impact injury or
sham surgery, male Sprague-Dawley rats were injected (i.p.) once daily for 18
days with either MPH (5 mg/kg) or saline vehicle (VEH) and motor function
assessed on post-operative days 1-4, followed by Morris water maze training to
find a hidden platform on days 14-18. The MPH treatment regimen was ineffective
in accelerating beam-balance or beam-walk recovery, but did significantly
decrease swim latencies when compared to VEH-treated controls. The results are
consistent with published studies showing improved outcome with MPH therapy.
Furthermore, this positive finding with delayed treatment suggests that
strategies that enhance catecholamine neurotransmission during the chronic post
injury phase may be a useful adjunct in ameliorating some of the neurobehavioral
sequelae following TBI in humans.
PMID- 10675787
TI - Modulation of the neuronal circuitry subserving working memory in healthy human
subjects by repetitive transcranial magnetic stimulation.
AB - We studied the effect of repetitive transcranial magnetic stimulation (rTMS) on
changes in regional cerebral blood flow (rCBF) as revealed by positron emission
tomography (PET) while subjects performed a 2-back verbal working memory (WM)
task. rTMS to the right or left dorsolateral prefrontal cortex (DLPFC), but not
to the midline frontal cortex, significantly worsened performance in the WM task
while inducing significant reductions in rCBF at the stimulation site and in
distant brain regions. These results for the first time demonstrate the ability
of rTMS to produce temporary functional lesions in elements of a neuronal network
thus changing its distributed activations and resulting in behavioral
consequences.
PMID- 10675788
TI - Differential effects of L-trytophan and buspirone on biogenic amine contents and
metabolism in Lurcher mice cerebellum.
AB - The effects of serotoninergic stimulation on monoamines were studied in the
heterozygous Lurcher (Lc/+) mutant mouse, a model of human cerebellar ataxia.
Wild type (+/+) and Lc/+ mice were treated for 40 days with L-tryptophan or
buspirone, and serotonin (5-HT), dopamine (DA), noradrenaline (NA) and their main
metabolites were measured in the cerebellum. In +/+ mice, only buspirone
increased concentrations of 5-HT metabolites. In the hypoplastic Lc/+ cerebellum,
indoleamines were higher, and increased further after both treatments. The 5-HT
turnover index was increased in +/+ mice by buspirone, while in Lc/+ mutants it
increased after L-tryptophan but was decreased by buspirone, indicating that in
the mutants nerve terminals synthesize and accumulate 5-HT, but may not utilize
it efficiently. Catecholamine contents remained unchanged in +/+ mice, but in
Lc/+ mutants with higher endogenous NA, L-tryptophan further increased NA and 3,4
dihydroxy-phenylacetic acid (DOPAC), and buspirone augmented NA, DA and DOPAC
levels.
PMID- 10675789
TI - Effect of intrathecal baclofen on gait control in human hereditary spastic
paraparesis.
AB - The covariation between thigh, shank and foot elevation angles during locomotion
was analysed by means of orthogonal planar regression in a patient with pure
hereditary spastic paraparesis before and after an intrathecal bolus of baclofen
and in seven healthy subjects. The size, shape and spatial orientation of the
loop defining patient's planar covariation (thigh angle vs. shank angle vs. foot
angle) significantly differed from the controls' before baclofen, whereas these
features resumed normal characteristics after baclofen injection. This shows that
alteration of the control of phase coupling for the co-ordination of lower limb
segments in human gait by increased spinal reflexes can be reversed by
intrathecal baclofen injection.
PMID- 10675790
TI - Dynamic characteristics and adaptability of reflex eye movements of Fyn-kinase
deficient mice.
AB - Fyn-kinase is expressed widely in the entire brain, including the cerebellum. Fyn
kinase-deficient mice are known to exhibit hypersensitivity to ethanol. To
evaluate the cerebellar functions of Fyn-kinase, we examined the dynamic
characteristics of the horizontal optokinetic response (HOKR) and vestibulo
ocular reflex (HVOR) and its adaptability in Fyn-kinase-deficient mice. The HOKR
was induced by sinusoidal oscillation of a checkered screen and the HVOR was
induced by sinusoidal oscillation of a turntable in darkness. The HOKR gains of
mutant mice were higher than those of the wild-type mice, and the HVOR phases of
mutant mice were less advanced than those of the wild-type mice. However, no
difference was noted in the adaptability of the HOKR induced by 1 h of sustained
screen oscillation between the mutant and wild-type mice. The cerebellar
functions appear to be unaffected by Fyn-kinase knockout.
PMID- 10675791
TI - Effects of acute systemic 3-nitropropionic acid administration on rat activity
and acoustic startle.
AB - Spontaneous activity, acoustic startle, and prepulse inhibition (PPI) of acoustic
startle were measured in male Sprague-Dawley rats 3-5 h after 0, 10, 15, or 20
mg/kg i.p. 3-nitropropionic acid (3-NP), a mitochondrial toxin. Mean activity was
significantly influenced by the 3-NP dose due to decreased activity for 20 mg/kg.
Mean startle amplitude was not significantly affected by the 3-NP dose. Means of
PPI for prepulses 6 and 12 dBA above background were smaller than means for
respective 0 mg/kg doses, but the main effect of 3-NP dose did not reach
statistical significance in ANOVA. The changes in measured exploratory-type
activity and, possibly, in startle PPI parallel the occurrence of clinical signs
exhibited at 3-5 h after 3-NP injection. Neural processing involved in these
quantitative behavioral endpoints seems to be affected as energy stores are
depleted and degenerative processes are beginning.
PMID- 10675792
TI - 5-Hydroxytryptamine-induced locomotor rhythm in the neonatal mouse spinal cord in
vitro.
AB - We examined the 5-hydroxytryptamine (5-HT)-induced locomotor rhythm in isolated
spinal cord preparations taken from neonatal mice on postnatal day (P) 0-3. Motor
activity was recorded from L2 and L5 ventral roots. Bath application of 5-HT (15
100 microM) evoked rhythmic bursts that alternated between the two sides, and the
bursts in the L2 ventral root alternated with those in the ipsilateral L5 ventral
root. After transection of the mid-lumbar cord, the locomotor rhythm in L2
persisted, while that in the L5 ventral root was abolished. This suggests that
the upper lumbar region has a greater ability to generate a locomotor rhythm than
the lower lumbar spinal cord. Kynurenate, a broad-spectrum glutamate receptor
antagonist, blocked the 5-HT-induced locomotor rhythm indicating that ionotropic
glutamate receptors are required for the rhythm to be generated.
PMID- 10675793
TI - gamma-Aminobutyric acid infusion in substantia nigra pars reticulata in rats
inhibits ascorbate release in ipsilateral striatum.
AB - A relatively high level of extracellular ascorbate in the striatum, which is
known to modulate impulse flow in striatal neurons, originates primarily from
glutamate-containing corticostriatal afferents. Increasing evidence suggests that
ascorbate release from these fibers is regulated by a multisynaptic loop that
includes gamma-aminobutyric acid (GABA) mechanisms in the substantia nigra. To
assess the role that nigral GABA plays in striatal ascorbate release,
extracellular ascorbate was monitored voltammetrically in the striatum during
infusions of GABA into the substantia nigra pars reticulata (SNr) of awake,
unrestrained rats. Compared to vehicle infusions, intranigral GABA lowered
striatal ascorbate by >50%. In contrast, intranigral application of picrotoxin, a
GABA antagonist, had the opposite effect. Neither GABA nor picrotoxin altered
striatal 3,4-dihydroxyphenylacetic acid (DOPAC), a major dopamine metabolite.
Collectively, these results indicate that intranigral GABA exerts a tonic
inhibitory influence on ascorbate release in the striatum.
PMID- 10675794
TI - Laterality effects in selective attention to threat after repetitive transcranial
magnetic stimulation at the prefrontal cortex in female subjects.
AB - Recently, several experiments have indicated that the left and right prefrontal
cortex (PFC) are differently involved in emotional processing. The aim of this
study was to investigate the role of the left and right PFC in selective
attention to angry faces by using a pictorial emotional Stroop task. Slow
repetitive transcranial magnetic stimulation (rTMS) was applied to the left and
right PFC of 10 female subjects for 15 min on separate days. Results showed a
significant effect of stimulation position: right PFC rTMS resulted in selective
attention towards angry faces, whereas left PFC rTMS resulted in selective
attention away from angry faces. This finding is in accordance with theoretical
accounts of the neural implementation of approach and withdrawal systems.
PMID- 10675795
TI - Diurnal preference, sleep habits, circadian sleep propensity and melatonin rhythm
in healthy human subjects.
AB - After 24-h sleep deprivation, 33 healthy young subjects entered the 10/20 min
ultra-short sleep-wake schedule for 26 h. Melatonin rhythm was hourly assessed
simultaneously. Results indicated that morning preference was significantly
correlated with habitual sleep onset (r=-0.41, P=0.04), habitual sleep offset (r=
0.52, P=0.002), melatonin peak time (r=-0.36, P=0.04), and sleep propensity onset
time (r=-0.36, P=0.04). The intervals between habitual sleep mid-point and
melatonin peak time and between habitual sleep mid-point and sleep propensity
onset time were significantly longer in morning-preference subjects than in
evening-preference subjects (P<0.05). These findings suggest that the variance of
diurnal preference may be related to differences in phase relations between
habitual sleep timing and the circadian pacemaker.
PMID- 10675796
TI - Inhibition by neuropeptide Y of fentanyl-induced muscular rigidity at the locus
coeruleus in rats.
AB - The aim of this study was to evaluate the effects of centrally administered
neuropeptide Y (NPY) on muscular rigidity induced by fentanyl in Sprague-Dawley
rats. They were anesthetized with ketamine (120 mg/kg, i.p.) and their lungs were
mechanically ventilated. Intravenous administration of fentanyl (100 microg/kg)
consistently evoked a significant increase in the electromyographic activity
(EMG) recorded from the sacrococcygeus dorsalis lateralis muscle. This implied
muscular rigidity was appreciably attenuated by intracerebroventricular
administration of NPY (4 nmol/2.5 microl). Microinjection of NPY (40 or 160
pmol/50 nl) into the bilateral locus coeruleus (LC) elicited an inhibition of the
EMG activation induced by fentanyl in a dose-dependent manner. Microinjection of
160 pmol NPY plus antiserum against NPY (NPY(Ab), 1:20) into the LC failed to
suppress fentanyl-induced muscular rigidity. However, this implied muscular
rigidity was not affected by NPY plus normal rabbit serum (NRS, 1:20). In
addition, NPY(Ab) or NRS per se had no substantial effect on the rigidity.
Microinjection of NPY (160 pmol) into the areas adjacent to the LC did not
attenuate the rigidity. Our results suggest that the centrally administered NPY
attenuated fentanyl-induced muscular rigidity by acting at the LC, but endogenous
NPY may not be involved in this process.
PMID- 10675797
TI - Polysialylated neural cell adhesion molecule modulates photic signaling in the
mouse suprachiasmatic nucleus.
AB - Polysialic acid (PSA), a sialic acid polymer that regulates plasticity and cell
cell interactions in neural tissues, is expressed in the mammalian circadian
clock located in the suprachiasmatic nucleus (SCN). In vivo enzymatic removal of
PSA from the mouse SCN significantly impaired both the photic induction of Fos
protein in SCN cells and light-induced phase-resetting of the circadian locomotor
activity rhythm. Genetic deletion of PSA and it's neural cell adhesion molecule
(NCAM) carrier correspondingly attenuated light-induced circadian phase-shifting.
Comparison of PSA levels between young and old mice revealed a large aging
related reduction in SCN PSA content that accompanies the diminished capacity for
circadian photic response reported in old rodents. Collectively these data
support the contention that PSA modulates photic signaling in the SCN, and that
normal reductions in the cell surface molecule contribute to aging-related
deficits in SCN circadian clock function.
PMID- 10675798
TI - Repeated administration of systemic gabapentin alleviates allodynia-like
behaviors in spinally injured rats.
AB - The effect of systemic gabapentin, a novel antiepileptic and analgesic, was
tested on allodynia-like behaviors in spinal cord injured rats. On the first day
of treatment 30 mg/kg intraperitoneal gabapentin did not alleviate hyper
reactivity to mechanical and cold stimulation. The allodynia was significantly
reduced by 100 mg/kg gabapentin, which however, produced sedation and motor
impairments. Repeated administration of 30 mg/kg gabapentin once a day produced a
gradually increasing anti-allodynic effect. Total alleviation of mechanical
allodynia was observed in most rats after the third administration of gabapentin.
Thus, build-up of the antiallodynic effect of gabapentin may develop through a
time dependent mechanism or alternatively through a gradual accumulation of the
effective central nervous system concentration of the drug.
PMID- 10675799
TI - Gender-specific association of the angiotensin converting enzyme gene with
Alzheimer's disease.
AB - Epidemiological studies have demonstrated that risk factors for vascular disease
are also risk factors for Alzheimer's disease (AD). The gene for the angiotensin
converting enzyme (ACE) has recently been reported to be associated with risk for
AD. We have investigated the possibility of such an association in 98 clinic
based and 73 community-based AD cases versus 175 community-based controls and
find a gender-specific association of ACE genotype with AD in the female clinic
population. These data suggest that gender may interact with genetic factors to
influence risk for AD. Gender-specific risk for AD has been previously reported,
and a biological rationale for involvement of ACE in the AD process is supported
by studies exploring the relationship between AD and vascular risk factors such
as hypertension. However, the results may also be a consequence of the known
anomalies that arise in genetic association studies as a consequence of sample
selection.
PMID- 10675800
TI - Differential neurotrophin levels in cerebrospinal fluid and their changes during
development in newborn rat.
AB - Cerebrospinal fluid concentration of nerve growth factor (NGF), brain-derived
neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) was measured in normal
developing rat from birth to postnatal day (PND) 21 by enzyme-linked
immunosorbent assay. NGF levels were significantly higher than those of BDNF and
NT-3 from PND 1-21. NGF levels decreased from PND 1-3 to PND 9. At PND 15 and 17,
NGF levels peaked a second time and rapidly decreased to PND 21. BDNF peaked at
PND 13-15, while NT-3 levels peaked at PND 7-9. Each of the three neurotrophins
has its own characteristic pattern in changes in cerebrospinal fluid levels.
PMID- 10675801
TI - Cloning of serotonin 5-HT(1) receptor subtypes from the chimpanzee, gorilla and
Rhesus monkey and their agonist-induced guanosine 5'gamma(35)S triphosphate
binding.
AB - 5-HT(1) receptor subtypes ((1B), (1D) and (1F)) have been implicated in migraine
pathophysiology and their ligands have been examined for pharmacological actions
in various experimental animal models. Considerable divergences exist, however,
in their primary sequences between experimental animals and human, and additional
models closer to human, such as non-human primates seem to be useful for migraine
research. Earlier, we cloned the 5-HT(1D), and here 5-HT(1B) and 5-HT(1F)
receptors from the chimpanzee, gorilla and Rhesus monkey, via polymerase chain
reactions with their genomic DNAs and primers designed from the corresponding
human receptors. Direct sequencing of PCR products showed that the 5-HT(1B)
receptors from the chimpanzee, gorilla and monkey differ from the human receptor
by 0, 1 and 7 residues, respectively while 5-HT(1F) receptors differ by 0, 3 and
10 residues, respectively. These divergent residues are mostly conservatively
substituted and also largely confined to the N-terminal region and the 3rd
intracellular loop, away from transmembrane segments and intracellular loops near
membrane which are critical for ligand binding and G protein coupling. The
chimpanzee 5-HT(1D), 5-HT(1B) and monkey 5-HT(1F) receptors, as heterologously
expressed in human embryonic kidney 293 cells, showed robust agonist-induced
guanosine 5'gamma (35)S triphosphate (GTPgamma(35)S) binding through activation
of G proteins containing Ggamma(i) subunits. Moreover, pronounced inhibition of
basal GTPgamma(35)S binding by methiothepin (an antagonist), representing
constitutively active receptors, was observed with only 5-HT(1D). Overall, ligand
binding and GTPgamma(35)S binding profiles for these primate receptors are
comparable to those for the human receptors and validate non-human primates as
useful models for human migraine research.
PMID- 10675807
TI - Coordination of two- and one-joint muscles: functional consequences and
implications for motor control.
AB - The purpose of this paper is three-fold: (a) to summarize available data on
coordination of major two- and one-joint muscles in multijoint tasks and identify
basic features of muscle coordination, (b) to demonstrate that there may exist an
optimization criterion that predicts essential features of electromyographic
activity of individual muscles in a variety of tasks, and (c) to address the
functional consequences of the observed muscle coordination and underlying
mechanisms of its control. The analysis of the literature revealed that basic
features of muscle coordination are similar among different voluntary motor tasks
and reflex responses. It is demonstrated that these basic features of
coordination of one- and two-joint muscles in two-dimensional tasks are
qualitatively predicted by minimizing the sum of muscle stresses cubed.
Functional consequences of the observed coordination of one- and two-joint
muscles are (a) reduction of muscle force as well as stress, mechanical and
metabolic energy expenditure, muscle fatigue, and perceived effort; (b) a spring
like behavior of a multi-joint limb during maintenance of an equilibrium posture;
and (c) energy transfer between joints via two-joint muscles. A conceptual scheme
of connections between motoneuron pools of one- and two-joint muscles, which
accounts for the observed muscle coordination, is proposed. An important part of
this scheme is the force-dependent inhibition and excitation from two-joint to
one-joint synergists and antagonists, respectively.
PMID- 10675808
TI - Energy-minimizing choices of muscles and patterns of movement.
AB - Prilutsky (1999, target paper) reports that Crowninshield and Brand's (1981)
criterion, minimization of the sum of the cubes of muscle stresses, works well as
a predictor of the division of labor between muscles, for various tasks. However,
no direct benefit from minimizing this particular sum is apparent, and it seems
likely that it is merely a correlate of the criterion that actually drives muscle
choice. In many tasks, there would be a clear, direct benefit from minimizing
metabolic energy costs, as Prilutsky (1999) points out. Alexander (1997a, 1997b)
and Minetti and Alexander (1997) have shown how the metabolic energy costs of
muscle contraction can be estimated, and used to predict optimum muscle
properties or optimal patterns of movement. This article explores the feasibility
of using the same approach to predict optimum division of labor between one- and
two-joint muscles.
PMID- 10675809
TI - Two-joint muscles offer the solution, but what was the problem?
AB - Prilutsky's paper is mainly concerned with the coordination of one- and two-joint
muscles. This commentary on the paper addresses the question why we have two
joint muscles in the first place. From an evolutionary point of view, two-joint
muscles must have contributed to fitness by presenting a solution to problems
that could not be solved with musculoskeletal systems comprising only one-joint
muscles. One such problem, not mentioned by Prilutsky, is the following. In a
system equipped with only one-joint muscles, satisfying directional constraints
would demand, in certain phases of movements, deactivation of muscles that are
shortening. Consequently, the work output of these muscles would be limited. The
incorporation of two-joint muscles helps to overcome this problem. The reason is
that it offers the possibility to redistribute energy across joints, thereby
making it possible to accomplish more successfully the difficult task of
producing work while steering the movement.
PMID- 10675810
TI - Too early to explain all experimental data with a single model.
AB - The target article by Prilutsky gives an excellent overview of the predictions of
the Crowninshield and Brand model and about the relevant literature about muscle
coordination. However, we do not agree with the claim that the Crowninshield and
Brand model can explain the coordination between one-joint and two-joint muscles.
In this commentary we will make three claims: (a) The Crowninshield and Brand
model cannot explain all aspects of muscle coordination, (b) there is good
experimental evidence that different constraints and models may be necessary to
explain muscle coordination in different motor tasks, and (c) the reason for the
lack of quantitative fits between predictions about muscle force and experimental
data is that it is hard to measure muscle force in man. As a compromise one has
to rely on EMG activity as a measure of muscle force. Because of the complex
relationship between EMG and muscle force, a quantitative test of models is
difficult.
PMID- 10675811
TI - Minimizing stress is not enough.
AB - Muscle stress is plainly one of the physical variables that the central nervous
system probably wishes to minimize. This criterion does not uniquely define the
patterns of muscle activation. It fails to explain the degree of coactivation of
muscle antagonists that is widely found, and it cannot explain why two movements
or movement segments that follow an identical trajectory driven by identical
joint torques can be driven by different patterns of muscle activation. Muscle
contraction provides for both net joint torque and limb stability. The
minimization of the sum of muscle stresses, raised to any power, is an
insufficient rule.
PMID- 10675812
TI - Coordination of one- and two-joint muscles during voluntary movement: theoretical
and experimental considerations.
AB - The target article by Dr. Prilutsky is based on three incorrectly derived
mathematical rules concerning force-sharing among synergistic muscles associated
with a cost function that minimizes the sum of the cubed muscle stresses. Since
these derived rules govern all aspects of Dr. Prilutsky's discussion and
conclusion and form the basis for his proposed theory of coordination between one
and two-joint muscles, most of what is said in the target article is confusing or
misleading at best or factually wrong at worst. The aim of our commentary is to
sort right from wrong in Dr. Prilutsky's article within space limitations that do
not allow for detailed descriptions of mathematical proofs and explicit
discussions of the relevant experimental literature.
PMID- 10675813
TI - General coordination principles elucidated by forward dynamics: minimum fatique
does not explain muscle excitation in dynamic tasks.
AB - The target article presents a framework for coordination of one- and two-joint
muscles in a variety of tasks. Static optimization analyses were performed that
minimize muscle fatigue, and it is claimed that the predicted muscle forces
account for essential features of EMG activity qualitatively well. However,
static optimization analyses use the observed joint moments, which implicitly
assumes that they minimize the total muscle fatigue of the task. We use a forward
dynamics (i.e., relationship between muscle forces and the kinematics and
kinetics of task performance) modeling approach to show that this assumption does
not appear to be true in cycling (which was used as an example task in the target
article). Our results challenge the hypothesized coordination framework and the
underlying concept that general coordination principles for dynamic tasks can be
elucidated using inverse-dynamics-based analyses.
PMID- 10675814
TI - Overcomplete musculature or underspecified tasks?
AB - The number of muscles in the body is actually fairly close to the number required
to control completely all its degrees of freedom. The apparent need for a
coordinating principle arises from the experimental practice of asking subjects
to perform simple movements and assuming that they make no implicit assumptions
about other constraints. Natural activities include implicit constraints that
differ greatly for different tasks and circumstances and that would be met best
by a nervous system free of a priori principles.
PMID- 10675815
TI - Subject specific coordination of two- and one-joint muscles during landings
suggests multiple control criteria.
AB - The target article, thoughtfully constructed by Dr. Prilutsky, effectively
synthesizes available data on multijoint movements regarding coordination
patterns of major two- and one-joint muscles, provides evidence for an
optimization criterion that predicts critical features of muscle activation
patterns, and explores the functional consequences of muscle coordination. This
work also provides a clear set of definitions and an organizational framework
that is currently needed for a productive interdisciplinary discussion regarding
the underlying control mechanisms used during realistic multijoint movements.
Although identification of an optimization criterion that predicts muscle
recruitment strategies would greatly simplify control logic required for
rehabilitation and musculoskeletal modeling, our experimental data during
landings indicate more than one criterion may exist. Preliminary review of our
experimental landing data suggests the rules identified by Prilutsky apparently
hold for some subjects during portions of the landing movements. The presence of
more than one muscle activation pattern used to achieve the same NJMs
demonstrates there may be more than one optimization criterion that predicts
critical features of muscle activation patterns. The functional consequences of
more than one control criterion may also prove to be an asset, particularly when
adapting to different environmental constraints.
PMID- 10675816
TI - Some mechanical considerations on muscle coordination.
AB - This commentary emphasizes three points of discussion. (a) The terminology: The
terms multifunctional, synergisic, antagonistic muscles, and synergistic and
antagonistic coactivations are discussed and the conclusion is drawn that they
could not be used without mentioning the particular joint motion. (b) The
importance of the external joint moments for activation of the muscles is
confirmed on the basis of logical and mechanical considerations. Not all
experimental results, however, could be explained by this means. (c) The
optimization criterion: Prilutsky's conclusion concerning the predicted muscle
force proportionality to the muscle moment arm and PCSA is confirmed using a
simple analytical solution of the optimization problem. It is shown, however,
that the proportionality to the PCSA is a consequence of the chosen optimization
criterion.
PMID- 10675817
TI - Muscle coordination: the discussion continues
AB - In this response, the major criticisms of the target article are addressed.
Terminology from the target article that may have caused some confusion is
clarified. In particular, the tasks that have the basic features of muscle
coordination, as identified in the target article, have been limited in scope. A
new metabolic optimization criterion suggested by Alexander (2000) is examined
for its ability to predict muscle coordination in walking. Issues concerning the
validation of muscle force predictions, the rules of muscle coordination, and the
role of directional constraints in coordination of two-joint muscles are
discussed. It is shown in particular that even in one-joint systems, the forces
predicted by the criterion of Crowninshield and Brand (1981) depend upon the
muscle moment arms and the physiological cross-sectional areas in much more
complex ways than either previously assumed in the target article, or incorrectly
derived by Herzog and Ait-Haddou (2000). It is concluded that the criterion of
Crowninshield and Brand qualitatively predicts the basic coordination features of
the major one- and two-joint muscles in a number of highly skilled, repetitive
motor tasks performed by humans under predictable conditions and little demands
on stability and accuracy. A possible functional significance of such muscle
coordination may be the minimization of perceived effort, muscle fatigue, and/or
energy expenditure.
PMID- 10675818
TI - [How can we limit the number of unnecessary appendectomies?].
PMID- 10675819
TI - [Management of Barrett's esophagus].
AB - The subject of this review concerns advances in the diagnosis, etiology,
complications, treatment and surveillance of Barrett's esophagus. Current
management of Barrett's esophagus is discussed and indications of surgical
treatment are clarified while specific destruction of Barrett's mucosa is
possible by endoscopic management (laser or photodynamic therapy).
PMID- 10675820
TI - [Chemotherapy, combined radiochemotherapy and new therapeutic approaches in
adenocarcinoma of the pancreas].
AB - For patients having undergone complete resection for adenocarcinoma of the
pancreas, combined radiochemotherapy protocols using bolus 5FU as neoadjuvant or
adjuvant treatments can help control disease spread and perhaps moderately
lengthen survival. As the rare controlled trials having tested these therapeutic
strategies have provided conflicting data, this therapeutic attitude cannot be
considered as a standard treatment. The tested protocols using combined
radiochemotherapy were developed in the sixties and seventies and have been
greatly improved since that time. New combinations for neoadjuvant and adjuvant
radiochemotherapy protocols are currently under evaluation in controlled
therapeutic trials. Systemic chemotherapy (gemcitabine, 5FU, platinum) has a
palliative effect, improving the quality of life in patients with advanced-stage
disease. Gemcitabine is easy to administer and has a low toxicity profile. It is
widely used in standard protocols. Therapeutic trials combining gemcitabine and
other cytotoxic agents are under way. Radiochemotherapy combinations using 5FU
are a palliative alternative for patients with locally advanced disease,
particularly those with painful symptoms. There is an urgent need for more
effective treatments against metastatic disease and for better loco-regional
management using a multidisciplinary approach. These patients should be treated
within the framework of therapeutic trials.
PMID- 10675821
TI - [Surgical techniques. Laparoscopic right colectomy].
PMID- 10675822
TI - [Surgical techniques. Left pancreatectomies].
PMID- 10675823
TI - [Images in surgery. Benign florid corticoadrenaloma].
PMID- 10675824
TI - [The world's first: laparoscopic portacaval H-graft shunt].
AB - Partial portal diversion prevents recurrent variceal hemorrhage in cirrhotic
patients. Surgical portacaval shunt and trans-jugular intra-hepatic portasystemic
shunt have both been realized. Endoscopic instrument's advances and surgeon's
skill level in laparoscopic surgery had overcome technical impediments.
Laparoscopy could be used in safety condition in shunt procedures. We present the
case report of surgical laparoscopic procedure for portacaval H graft shunt.
PMID- 10675825
TI - [Pseudomyxoma peritonei. A review].
AB - Pseudomyxoma peritonei is a rare disease characterized by the presence of a large
mucin component within the abdomen. Recent pathological and genetic advances
indicate that they originate from an appendiceal adenoma or adenocarcinoma. Their
prognostic is worse than ovarian border-line mucinous tumors (with which they are
frequently confused). Currently, the histologic aspect permits to separate the
diffuse peritoneal adenomucinosis (DPAM) originating from adenomas, with a
relatively benign course, from the mucinous peritoneal carcinomatosis (MPC)
originating from adenocarcinomas, with a very poor prognosis. Paradoxically, the
treatment of these two diseases are rather similar, with supra-radical surgery as
frequently as possible. This type of surgery allows to reach a crude 5-year
survival comprised between 50% and 70%, with very different results according to
the DPAM-type or the MPC-type. The adjunction of an intraperitoneal chemo
hyperthermia is logical for these two types of disease and probably increases the
survival rate.
PMID- 10675827
TI - [In Process Citation]
PMID- 10675826
TI - [Congress of the American College of Surgeons (ACS). San Francisco, 10-15 October
1999].
PMID- 10675828
TI - [Initial access for laparoscopic gynecologic surgery. French Society of
Endoscopic Gynecology, International Society of Pelvic Surgery and the National
College of French Gynecologists-Obstetricians].
PMID- 10675829
TI - [Human papillomaviruses, cell cycle and cervical cancer].
AB - Human papillomaviruses (HPVs) are associated with a broad spectrum of cutaneous
and mucosal lesions. Until now, more than 120 genotypes have been identified.
Most HPVs are associated with benign lesions. Nevertheless certain HPV types are
frequently found in carcinomas. For instance, HPV 16 and 18 which are frequently
associated with cervical cancer, are capable of immortalizing and transforming
primary keratinocytes. The mechanism of transformation is linked to the viral
genome integration into the cell's DNA, accompanied by an overexpression of the
E6 and E7 genes. The viral gene products interact with cellular proteins that
regulate the cycle progression. In particular, the E6 protein binds to the p53
and the E7 protein binds to the p105(Rb). The inactivation of both cellular
proteins distorts the cell cycle and results in genetic instability and cellular
gene alterations. This article reviews the role of the viruses in the
carcinogenesis, the genome structure and the gene expression of HPVs. It also
addresses the cell cycle regulation with a focus on the role of HPVs in cell
transformation.
PMID- 10675830
TI - [Management of lymphoblastic lymphomas during pregnancy].
AB - Lymphoblastic lymphoma (non-Hodgkin lymphoma) is a highly uncommon but serious
condition during pregnancy. With multidisciplinary management (obstetrics,
pediatrics, hematology and anesthesia), outcome is generally good for both mother
and child. Chemotherapy must be initiated rapidly, during pregnancy. Consequences
depend on the stage of the disease, its progressive nature and the of pregnancy.
During the first trimester, medical termination should be proposed in order to
initiate chemotherapy cannot be started until the second trimester using
alkaloids. Chemotherapy has little effect on the fetus during the second
trimester. During the trimester, extraction should be discussed as soon as the
fetal maturity is sufficient.
PMID- 10675831
TI - [Effect of combined conjugated estrogen-medrogestone replacement therapy on lipid
profiles, climacteric symptoms and the endometrium].
AB - OBJECTIVE: To assess the effects of continuous administration of conjugated
estrogen combined with sequential administration of medrogestone on lipid
profiles, climateric symptoms and endometrial tolerance. METHODS: This
multicenter open study was conducted for one year to assess the effects of a
hormone replacement therapy (HRT) regimen using Premarin (0.625 mg/day 28d/28)
combined with medrogestone 5mg for 12 days (d17-d28 of each 28-day cycle) on
lipid profiles, climateric symptoms and cycle control in 228 post menopausal
women with an intact uterus. The subjects were recruited in 23 centers in 7
countries in Europe and Asia. Serum lipid/lipoprotein levels were determined at
baseline and at cycles 3, 6, 13; endometrium biopsies were performed at screening
then at cycle 13. Climateric symptoms and bleeding patterns were recorded by the
patients from daily diaries cards collected at baseline and at visits during
cycle 3, 6, 9, and 13. RESULTS: By cycle 3, the conjugated estrogen-medrogestone
combination induced significant modifications of the lipid profile which were
judged favorable. These modifications were maintained throughout treatment. All
the baseline values were within normal limits. Mean variations compared with
baseline values (expressed in mmol/l) after cycles 3, 6, and 13 were -0.46,
0.54, and -0.46 for total cholesterol (p<0.05), + 0.053, + 0.057, and + 0.078 for
HDL-cholesterol (p<0.05) and -0.556, -0. 542, and -0.493 for LDL-cholesterol
(p<0.001) respectively. VLDL-cholesterol levels were unchanged. Triglycerides
increased significantly though moderately: + 0.12, + 0.15, and + 0.15 mmol/l at
cycles 3, 6, and 13 respectively. Endometrial biopsies obtained at cycle 13
(n=195) did not reveal any endometrial hyperplasia. Withdrowal bleeding was
predictable for a 6 to 7.4 day interval. The incidence of irregular bleeding
varied from 7 to 33% and decreased progressively over the 13-cycle treatment. The
incidence of amenorrhea increased from 14 to 52% over the 12 months studied.
Finally, at each cycle, menopausal symptoms (mean number of hot flushes/day and
Kupperman score) were significantly improved compared with the baseline. As
expected, modifications were more pronounced after cycle 1, but improvements were
maintained throughout the study. CONCLUSION: Continuous administration of
Premarin in combination with sequential administration of medrogestone was found
to be an effective treatment for menopausal symptoms. It was associated with
favorable modifications of the lipid profile and was safe for the endometrium.
PMID- 10675832
TI - [Hysterectomy for benign lesions in Brittany: analysis of medical practices].
AB - OBJECTIVES: By who, why and how are done hysterectomies for benign lesions.
MATERIAL: and methods. The 413 medical files of all the patients who underwent an
hysterectomy for benign lesion during the last trimester of 1997 were recorded by
the Medical Information Departments of the 53 health establishments of the
Brittany Region. Surgical procedures, medical indications, pathological findings
were analyzed according to the guidelines encountered in the medical literature.
RESULTS: Hysterectomies were done by many surgeons (112). Inaugural signs noted
in the medical files were classical, but various and often associated without a
main indication of hysterectomy. Histological diagnose were identical with those
found usually in the literature. The abdominal route was mainly used,
particularly when the operation was done by a generalist surgeon and in case of
uterus weight superior to 250 g. The post operative outcome has revealed the same
nature and frequency of complications as usually described. CONCLUSION: In this
study, it appears that efforts remain necessary to clarify the indications for
hysterectomy in the medical files (in order to promote the alternative procedures
to the hysterectomy), and that the proportion of hysterectomies performed by the
abdominal route should be reduced in aid of the others surgical routes.
PMID- 10675833
TI - [Cervical adenocarcinomas: diagnostic, prognostic and therapeutic aspects in a 49
case-control study].
AB - OBJECTIVES: The aim of this study was to search for potential diagnostic,
therapeutic and prognosis differences between a series of 49 adenocarcinomas of
the cervix and a matched series of epidermoid carcinomas. METHODS: Forty-nine
adenocarcinomas were treated between 1978 and 1992 and retrospectively compared
to a series of 98 paired epidermoid carcinomas. RESULTS: The adenocarcinoma
incidence is 5.4%. There was no significant difference for age distribution,
parity, or hormonal status. There was also no significant difference for clinical
features. Stage I appeared more frequently in the adenocarcinoma group (stage I:
69.4%, stage II: 14.3%, stage III: 14.3%, stage IV: 2%). Stage I are also more
frequently found in the adenocarcinoma group (69.4% versus 42. 9%, p< 0,05).
Combined radio-surgical treatment was proposed more often for the adenocarcinoma
group (respectively radio-surgery combination 73%, radiotherapy alone 18%,
surgery 9%); in the epidermoid carcinoma group, combined radio-surgical treatment
and radiotherapy were the usual treatment (46%); surgery alone appeared in third
rank place (8%). Adenocarcinoma pelvic recurrences appeared more frequently
(28.6% for adenocarcinoma group versus 13.3% for epidermoid group p< 0.05), while
distant recurrence was the same (12. 2% for adenocarcinoma group versus 11.2% for
epidermoid group, p< 0. 05). Five years overall survival rate was worse for the
adenocarcinoma group (52% versus 63.7%, p< 0.05) but the difference was not
significant for the disease free survival rate. Only for stage Ib, there are also
more pelvic recurrences (35.4% versus 13.1%, p< 0.05), more distant recurrences
(9.6% versus 2.6%, p< 0.05), and lower overall survival for adenocarcinomas
(58.7% versus 88.5%, p< 0. 01). CONCLUSION: The incidence of adenocarcinomas is
slightly increasing (absolute value in our experience) and the low stages seem to
be more frequent in our experience probably by staging inaccuracy. Adenocarcinoma
prognosis seems to be worse because of its poor radio-sensitivity. It seems
necessary to optimize clinical staging and therapeutic protocols excluding
radiotherapeutic approach, including surgical purposes or radio-surgical
associations if unfavorable histological features or tumoral enlargement (T> 3
cm) are found.
PMID- 10675834
TI - [Risk factors for prematurity in France and comparisons between spontaneous
prematurity and induced labor: results from The National Perinatal Survey 1995].
AB - OBJECTIVE: To study risk factors of total preterm delivery, spontaneous preterm
delivery and induced preterm delivery. POPULATION: Representative sample of
births in 1995 in France, including 12869 single births. METHOD: Preterm
deliveries included all births before 37 weeks. Risk factors were analyzed with
logistic regression. Factors of spontaneous preterm delivery (after spontaneous
onset of labor) and factors of induced preterm delivery (after induction or
cesarean section before labor) were compared with polytomous logistic regression.
RESULTS: The main risk factors of preterm delivery were history of adverse
pregnancy outcome (ORa=4. 5), history of induced abortion (ORa=1.5), 35 year old
or more (ORa=1.5) and inadequate antenatal care (ORa=2.1). Other factors such as
age under 20 or being single were not significantly linked to preterm delivery.
Risk factors differed slightly between spontaneous and induced preterm
deliveries. CONCLUSION: The present risk factors do not always correspond with
the well-known factors. Thus the assessment of risk factors would be necessary at
regular interval. The small differences between the risk factors of spontaneous
preterm delivery and induced preterm delivery may be explained by difficulties in
defining those two types of preterm delivery or by difficulties in distinguishing
specific causes for each of them.
PMID- 10675835
TI - [Metrorrhagia during the second trimester of pregnancy: obstetrical and perinatal
outcome. A retrospective study including 85 cases].
AB - OBJECTIVE OF THE STUDY: To examine pregnancy outcome in patients with second
trimester vaginal bleeding and to determine a relationship between presumed
etiology and perinatal outcome. MATERIAL: and methods: A retrospective study
performed in Toulouse La Grave CHU between January 1993 and December 1997
including 85 cases of vaginal bleeding from 15 to 27 week's amenorrhea (90
fetuses). Results are compared to overall deliveries during the same period
(14941 deliveries). RESULTS: Mean age at diagnosis is 29.8 years (SD: 5.3 years).
Vaginal bleeding in the midtrimester concern 0.57% of deliveries. Abnormal
ultrasonographic findings are observed in 73% of patients (placenta previa,
subchorionic hematoma, placental abruption) and 81% were hospitalized (mean
hospital duration: 18 days). Perinatal mortality was 17.04% and preterm delivery
rate 30.6% (vs 11% in the overall patients). Perinatal complications are
significatively increased compared with the overall population especially if
ultrasonographic examination was abnormal. Second-trimester placental abruption
had the worse prognosis. On the other hand, perinatal outcome was comparable when
the origin of bleeding was unknown and ultrasonographic examination normal. 41%
patients underwent cesarean section. CONCLUSION: Preterm delivery, perinatal
mortality and morbidity are increased in patients with second-trimester vaginal
bleeding. The risk is higher when abnormalities are detected at ultrasonography
making ultrasonography a useful tool for predicting perinatal outcome.
PMID- 10675836
TI - [Materno-fetal platelet allo-immunization revealed by in utero intracerebral
fetal hemorrhage: proposed management for the next pregnancy].
AB - Materno-fetal platelet allo-immunization causes fetal or neonatal
thrombocytopenia and sometimes severe intracerebral bleeding. The HPA-1s antigen
is most generally implicated. This accident can occur during the first pregnancy
with a major risk of severe recurrence during the next pregnancy. These women
require specific care in a specialized center although no consensus has been
reached on management of second pregnancies. Proposed treatments include
immunoglobulins and/or corticosteroids, fetal blood puncture and unique or
iterative platelet transfusions.
PMID- 10675837
TI - [Drug use during pregnancy: survey in 250 women consulting at a university
hospital center].
AB - A prospective study of drug use in pregnancy was performed in the maternity
outpatient department of a university hospital in Southwestern France. Two
hundred and fifty pregnant women were selected at random and interviewed. Eighty
four percent of the women reported drug consumption, with an average of two
medications per week. Some factors were significantly associated with an increase
in drug use: European origin, high level of education, medical history, alcohol
consumption. The most commonly used drugs were iron (43% of the women),
medications for venous disorders (22%) and gynecology (21%) and analgesics (19%).
Chronic use (beginning before pregnancy) occurred in 9% of the women. Self
medication accounted for around 20% of the women. Adverse effects were described
by the women 25 times out of 544 exposures: they concerned 10 drugs and were not
"serious". After delivery, 14 cases of malformations of the new-born, three
stillbirths, 25 neonatal pathologies and 10 resuscitations were observed. Except
one neonatal withdrawal syndrome after "in utero" exposure to benzodiazepines, no
relationship between drug exposure and pregnancy outcome could be established.
PMID- 10675838
TI - [Sickle cell anemia and pregnancy: review of 68 cases in Guadeloupe].
AB - Pregnancy in women with major sickle cell syndromes is a high risk maternofetal
situation. This descriptive study presents the features and the clinical course
of 68 pregnancies in sickle cell women who were delivered in Guadeloupe from
January 1(st) 1993 to December 31(st) 1997. Specific complications were observed
in all hemoglobin types, but with a severer course in SS women. Painful vaso
occlusive crises were the main causes of hospitalisation (88% of SS pregnancies
and 27% of SC pregnancies) associated most often with worsening anemia and / or
infection. Acute chest syndrome was observed in all genotypes at any time
throughout pregnancy and during the post partum period. One death occurred (a 16
years old SBeta(+)thal woman). Fetal mortality and morbidity were also high,
intrauterine growth retardation and fetal death being the most frequent fetal
complications. The rates of prematurity (21%) and caesarean section (48%) were
higher than in the whole population. Three (3) neonatal deaths occurred. A
multidisciplinary and specific approach, vigilance of health care providers and
patient compliance are required to manage efficiently pregnancy, delivery and
post partum in sickle cell women.
PMID- 10675839
TI - [Length of stay in maternity wards after normal delivery: diverging point of
views].
AB - OBJECTIVES: To compare maternity ward professionals' and patients' views
regarding the length of stay in the maternity after a normal delivery and to
explore working relationships with ambulatory health professionals. METHODS:
Three surveys RESULTS: General professional agreement on a minimum of 4 days; few
contacts with ambulatory health professionals. One third of the women found their
length of stay excessive. Most did not appear to gain new skills after 3 days,
nor to encounter major difficulties once they returned to their home. DISCUSSION:
and conclusion. It will be essential to organize effective working relationships
between the maternity ward and ambulatory health professionals to ensure
appropriate follow-up after an earlier discharge from the hospital, in agreement
with the capabilities and expectations of a majority of women.
PMID- 10675841
TI - [In Process Citation]
PMID- 10675840
TI - [Granulomatous recurrent mastitis during pregnancy].
AB - We report a case of granulomatous mastitis during pregnancy which raised
important diagnostic and therapeutic problems. Several diagnoses were suspected
and subsequently different therapeutic regimen were tried (antibiotic therapy
associated with nonsteroidal antiinflammatory drugs, progestogens, vein tonicity
drugs and bromocriptine). All were ineffective and the patients status worsened.
Histology confirmed the diagnosis of granulomatous recurrent mastitis.
Corticosteroid therapy and interruption of pregnancy successfully controlled the
disease process.
PMID- 10675842
TI - [In Process Citation]
PMID- 10675843
TI - [Difficulties in antenatal recognition of fetal macrosomia].
PMID- 10675844
TI - [Obstetrical strategies and emergency procedures for delivery of macrosomic
fetuses].
PMID- 10675845
TI - [The macrosomic newborn in the maternity ward: practical attitude].
PMID- 10675846
TI - [Obstetrical paralysis of the brachial plexus].
PMID- 10675847
TI - [Long-term consequences of fetal macrosomia].
PMID- 10675848
TI - [Management of pregnant women with chronic psychiatric disorders].
AB - This paper describes the psychic changes occurring within motherhood and their
effects on the various kinds of mental disorders. The necessity of a
multidisciplinary preventive and intervention network is emphasized. However,
prenatal assessment is not predictive of what will happen postnatally. Only with
the birth of the infant will the assessment of parenting begin. Some modification
of the infancy and childhood protective regulations could help improving this
post natal assessment of parenting ability.
PMID- 10675849
TI - [Pre and postnatal depressions: importance of detection and care].
AB - It is highly important to recognize and care for pre and post delivery breakdown
in order to relieve the mother's psychological pain and favor the ongoing
motherhood process as well as the baby's psychological development which can be
hampered by the rupture of mother child interactions during the early months of
life due to the mother's depressive condition.
PMID- 10675850
TI - Symptomatic Valgus Knee: The Surgical Options.
AB - Valgus knee deformities requiring surgery are difficult to manage due to the
relative rarity and abnormal biomechanics of the condition and the unique soft
tissue and osseous pathologic features. Surgical options include arthroscopic
debridement, abrasion arthroplasty, proximal tibial varus osteotomy, distal
femoral varus osteotomy, combined femoral-tibial varus osteotomy,
unicompartmental knee arthroplasty, and total knee arthroplasty. Each procedure
has its own indications, contraindications, and limitations.
PMID- 10675851
TI - Carpal Instability: Evaluation and Treatment.
AB - Carpal instability is a common cause of wrist pain, motion loss, and disability.
Diagnosis and treatment of carpal instability are dependent on a clear
understanding of wrist anatomy and carpal kinematics, both normal and pathologic,
as well as their relation to the current concepts regarding management. A brief
review of anatomy and normal kinematics is presented, followed by a detailed
discussion of specific instability patterns, including pathomechanics. A
treatment algorithm is provided, detailing the authors' preferred treatment for
the most common instability patterns.
PMID- 10675852
TI - Total Joint Replacement: Optimizing Patient Expectations.
AB - Rehabilitation of the patient who has undergone total hip or knee replacement
embraces many facets of care, including prevention of complications, patient
education, and a program of gradual resumption of normal functions. This program
may be divided into three phases. In the perioperative phase, elimination of
factors that contribute to morbidity will facilitate resumption of physical
activities. In the interim phase (the first year following surgery), the
patient's desire to return to full activities must be tempered by the goal of
preserving for the longest possible time the mechanical-biologic construct of the
joint replacement. Although a final functional result is usually achieved in the
first 2 to 3 years following surgery, the patient must be followed up
indefinitely. During this third phase of long-term assessment, the question of
whether total joint arthroplasty was a success must be answered by the surgeon,
by the patient, and by society.
PMID- 10675853
TI - Glenohumeral Instability: Evaluation and Treatment.
AB - Glenohumeral instability encompasses a spectrum of disorders of varying degree,
direction, and etiology. The keys to accurate diagnosis are a thorough history
and physical examination. Plain radiographs are frequently negative, especially
in subtle forms of instability. Computed tomography (CT), CT arthrography,
magnetic resonance imaging, arthroscopy, and examination under anesthesia may
occasionally yield important diagnostic information. Nonoperative treatment of
shoulder instability consists of reduction of the joint (when necessary),
followed by immobilization and rehabilitative exercises. The length and the value
of immobilization remain controversial. Rehabilitative programs emphasize
strengthening f the dynamic stabilizers of the shoulder, particularly the rotator
cuff muscles. Both arthroscopic and open techniques can be used for operative
stabilization of the glenohumeral joint. Results of these repairs are assessed
not only in terms of recurrence rate, but also in terms of functional criteria,
including return to athletics. Some standard repairs have declined in popularity,
giving way to procedures that directly address the pathology of detached or
excessively lax capsular ligaments without distorting surrounding anatomy.
Capsular repairs also allow correction of multiple components of instability.
PMID- 10675854
TI - Percutaneous Lumbar Diskectomy.
AB - The development of an approach for percutaneous lumbar diskectomy (PLD) began
over 20 years ago. Since then, clinical investigations of manual and automated
PLD techniques have recorded an average success rate of 50% to 70%. Currently,
the indications for PLD include (1) a major complaint of acute unilateral leg
pain localized to a single dermatome associated witha a single-disk herniation;
(2) neurologic signs or symptoms appropirate to a single-disk herniation; (3)
magnetic resonance imaginng, computed tomographic, or diskographic evidence of a
single herniation contained within the annulus of the lumbar disk; and (4)
failure of a well-managed course of conservative treatment to relive the pain and
symptoms. Conventional laminotomy/laminectomy, with or without the use of a
microscope or surgical loupes, remains the usual method of surgical care for
symptomatic lumbar disk disease. The role of PLD awaits further prospective
randomized controlled studies.
PMID- 10675855
TI - Meniscus Tears: Treatment in the Stable and Unstable Knee.
AB - Basic science research and follow-up studies after meniscectomy have provided
convincing evidence of the importance of preservation of the meniscus in
decreasing the risk of late degenerative changes. Whether in a stable or an
unstable knee, if a meniscus tear cannot be repaired, a conservative partial
meniscectomy should be undertaken to preserve as much meniscal tissue as
possible. When feasible, repair should be carried out in young patients with an
isolated meniscus tear, despite healing rates that are significantly lower than
those obtained when meniscus repair is done with anterior cruciate ligament (ACL)
reconstruction. The incidence of successful healing is inversely related to the
rim width and tear length. In general, meniscus repair should be limited to
patients under 50 years of age. Vertical longitudinal tears, including bucket
handle tears, are most amenable to repair. Some radial split tears can be
repaired. In an ACL-deficient knee, meniscus repair is more prone to failure if
not performed in conjunction with an ACL reconstruction, and is not recommended.
Meniscal allograft surgery is investigational but may hold promise for selected
patients.
PMID- 10675856
TI - Osteoporosis: The Role of the Orthopaedist.
AB - Osteoporosis is one of the most prevalent musculoskeletal disorders encountered
in orthopaedic practice today. This review provides an update on the
pathophysiology of bone metabolism leading to osteoporosis, describes the latest
methodology in the diagnostic workup of patients with low bone mass, and
summarizes the current status of osteoporosis treatment regimens. The special
needs of the osteoporotic fracture patient are also addressed. In general, load
sharing devices and sliding nail-plate constructs are preferred over rigid
internal-fixation systems. Prolonged immobilization should be avoided.
PMID- 10675857
TI - Isolated and Combined Posterior Cruciate Ligament Injuries.
AB - Posterior cruciate ligament (PCL) injuries represent 3% to 20% of all knee
ligamentous injuries, but the diagnosis often is missed at initial evaluation.
Diagnostic acumen is increased by knowledge of knee biomechanics and selective
ligament-cutting studies. The examiner must differentiate the isolated PCL injury
from combined ligamentous injury to determine appropriate treatment. Isolated
acute PCL tears with less than 10 mm of posterior laxity at 90 degrees of flexion
should be treated with an aggressive rehabilitative program. This amount of
laxity is found in the majority of isolated acute PCL tears. Isolated acute PCL
tears with more than 10 to 15 mm of posterior laxity and PCL tears with combined
ligamentous injuries should be reconstructed. Large PCL bony avulsions should be
fixed internally. Small PCL bony avulsions with more than 10 mm of posterior
laxity should be reconstructed. Chronic PCL injuries initially should be treated
with an aggressive rehabilitation program. If such a program is not successful in
a patient with more than 10 to 15 mm of posterior laxity and no significant
radiographic evidence of degenerative changes, the PCL should be reconstructed.
PMID- 10675858
TI - Metastatic Tumors of the Spine: Diagnosis and Treatment.
AB - Metastatic disease of the spine occurs in as many as 70% of patients with
disseminated cancer and may result in vertebral collapse, spinal instability, and
progressive neurologic compromise. Today, magnetic resonance imaging is the most
effective means of differentiating benign from malignant causation of vertebral
collapse, based on the imaging patterns and extent of marrow ablation. The more
rapid the onset of the neurologic deficit, the worse the prognosis for recovery,
no matter what treatment is instituted. The majority of vertebral lesions
requiring decompression and stabilization emanate from the vertebral body and are
best managed by anterior decompression and stabilization alone. With posterior
element destruction, spinal subluxation through the involved segment, or
involvement of the lumbar spine, a combination of both anterior and posterior
stabilization is required. The author's preference is to perform anterior
vertebral replacement with methylmethacrylate incorporating a Knodt distraction
rod. This construct affords instantaneous stability that is not adversely
affected by postoperative irradiation. Many devices can provide adequate
posterior stabilization, but the author prefers to use Luque rods with sublaminar
wire fixation. In a series of 77 patients with major neurologic compromise
treated with this technique, 62% showed improvement by at least two Frankel
grades, compared with fewer than 5% who improved after laminectomy decompression
with or without irradiation. Nineteen of the 77 patients remained alive more than
4 years postoperatively.
PMID- 10675859
TI - Tendon Disorders of the Foot and Ankle.
AB - Attritional and traumatic injuries to the tendons around the foot and ankle are
not uncommon. Treatment of overuse-type injuries (tendinitis) remains
straightforward. However, surgical treatment of peroneal subluxation, Achilles
tendon ruptures, and posterior tibial tendon insufficiency remains somewhat
controversial. Generally speaking, soft-tissue reconstruction of the superior
peroneal retinaculum is superior to bony procedures for peroneal dislocation.
Open repair of a torn Achilles tendon is more predictable than closed treatment.
Good clinical judgment is needed in determining the best treatment for posterior
tibial tendon problems. The painful os peroneum syndrome is a newly described
spectrum of posttraumatic conditions that may be the cause of lateral foot pain,
which is frequently difficult to identify.
PMID- 10675860
TI - Locked Femoral Nailing.
AB - Locked intramedullary nailing has become the standard of care for most femoral
fractures. Originally designed to prevent rotation and shortening in comminuted
fractures of the midshaft, its application has been extended proximally and
distally to nearly all femoral fractures from the lesser trochanter to the
supracondylar area. Achieving a closed reduction and selecting the proper
starting point in the piriformis region are crucial to a successful result.
Following the proper surgical technique for the specific nail used is more
important than nail material or design. Large-diameter reamed nails provide
greater strength than unreamed nails. Static locking has been shown to yield
nearly the same high union rates as dynamic locking and is now the accepted
standard. Distal targeting of the interlocking screw remains the most difficult
aspect of the surgical technique; most surgeons prefer freehand targeting with a
sharp trocar. Second-generation (reconstruction) nails, with screws directed
toward the femoral head, has extended the indications for locked nailing
proximally to subtrochanteric fractures and combined femoral neck-shaft
fractures.
PMID- 10675861
TI - Elbow Arthritis: Treatment Options.
AB - The treatment of elbow arthritis is conceptually similar to that for arthritis of
other major joints. The treatment of elbow arthritis has been evolving rapidly
due to advances in arthroscopic techniques and surgical treatment for
contractures and improved prosthetic designs. The reliability of total elbow
replacement is approaching that of total replacement of the knee, hip, and
shoulder. There remain a number of controversies and unanswered questions that
require further experience and longer follow-up for resolution.
PMID- 10675862
TI - Plica: Pathologic or Not?
AB - A fold that occurs within a joint is referred to as a plica synovialis. Three
such plicae are seen with regularity within the human knee joint. These folds are
normal structures that represent remnants of mesenchymal tissue and/or septa
formed during embryonic development of the knee joint, and can be seen during
arthroscopic inspection of the knee joint. Controversy exists within the
orthopaedic community as to whether a plica can develop pathologic changes
sufficient to cause disabling knee symptoms. The author defines the clinical
syndrome, describes the arthroscopic appearance of pathologic plica, and outlines
nonsurgical and surgical methods of management of this uncommon condition.
PMID- 10675863
TI - Outcomes Research in Orthopaedics.
AB - A new agenda in outcomes research has developed in the past decade. The stimulus
has come as the result of rapidly increasing health care costs, marked variations
in utilization of health care services, and deficiencies in the research
literature. Outcomes research includes methods such as analysis of large
databases, small-area analysis, structured literature reviews (meta-analysis),
prospective clinical trials, decision analysis, and guideline development.
Clinical research should be prospective and should employ modern statistical and
assessment methods. The focus of this research is on patient-oriented outcomes of
care rather than on assessments of the process of care. To illustrate these
applications in orthopaedics, lumbar spine fusion with internal fixation for
"spinal instability" is presented as an example. Completed large-database
analyses, small-area variation studies, and a meta-analysis indicate the need for
clinical studies. An outline of the form and content of such a study is
presented.
PMID- 10675864
TI - 1999 Costenbader Lecture. Outcome study in amblyopia: treatment and practice
pattern variations.
AB - This study retrospectively evaluates the results of amblyopia therapy and
suggests hypotheses for future study. We address the various methods of treatment
and evaluate the results from the most common therapy techniques. Practice
pattern variations were analyzed in addition to the analysis of overall results.
For ophthalmologists, there is a need to determine whether actual medical
practice approaches the established standard of care, if it exists at all. How
often are medical procedures, thought to be appropriate, based on anecdotal
observation (case reports) rather than hard data (clinical trials)? The 3 types
of vision loss evaluated were strabismic, anisometropic, and deprivation
amblyopia. The methods of treatment studied were full-time patching part-time
occlusion, penalization, and occlusion of the contact lens. Nine centers, thought
to have private as well as indigent patients, were recruited to participate in
this study. The centers responded by filling out an extensive questionnaire and
sending the information through the World Wide Web for inclusion in a
spreadsheet. This information was then collated, and various statistical programs
tabulated the results. Although trends, as a consequence of therapy, are
suggested from our retrospective analysis, concrete results can only arise from a
randomized prospective study. The study included 279 patients. There were a
similar number of male and female patients. Only 77% of the patients without
fusion before treatment had either single binocular vision or peripheral fusion
at the conclusion of therapy. The log improvement of vision was significant in
each group. Factors that potentially influenced the results were severity of
distance acuity in the amblyopic eye before treatment, duration of treatment, and
length of daily patching. The paper suggests that worse vision, not better
vision, at the beginning, predicts better outcome in terms of improvement of
visual acuity. For example, visual acuity less than 20/70 at the initiation of
treatment led to better visual results of geometric log improvement.
Surprisingly, among the 9 centers studied, there was a statistically significant
difference in many of the areas related to practice patterns. Patient compliance,
which directly affects outcome, was highly variable and is a factor that may be
readily influenced by the treating physician.
PMID- 10675865
TI - Why does early surgical alignment improve stereoacuity outcomes in infantile
esotropia?
AB - PURPOSE: Recent studies of infantile esotropia suggest that early surgical
alignment may enhance stereopsis and that alignment during the first 6 months of
life may be optimal. Early surgery both establishes alignment during an early
critical period for the development of stereopsis and minimizes the duration of
misalignment. Here we examine the role of these 2 factors in promoting improved
stereopsis outcomes. METHODS: Participants were 129 consecutive patients enrolled
in a prospective study of infantile esotropia who were followed up for a minimum
of 5 years. At ages 5 to 9 years, Randot stereopsis was evaluated. RESULTS:
Multiple linear regression indicated that duration of misalignment, but not age
at alignment or age at onset, was a significant factor in determining random dot
stereopsis outcomes. Moreover, patients with stereopsis were less likely to have
a loss of horizontal eye alignment requiring surgery than patients without
stereopsis (14% versus 32%; z = 1.96, P =.05). Patients with stereopsis were also
less likely to have dissociated vertical deviation than patients without
stereopsis (25% versus 63%; z = 3.36, P <.001). CONCLUSIONS: The results suggest
that early surgical alignment is associated with better stereopsis in those
patients with infantile esotropia who were treated during the first 24 months of
life, because early surgery minimizes the duration of misalignment, not because
alignment is achieved during an early critical period of visual maturation.
Random dot stereopsis can also be achieved in patients with alignment provided
that the duration of misalignment is not prolonged. Improved outcomes of random
dot stereopsis are associated with more stable long-term alignment outcomes.
PMID- 10675866
TI - Factors influencing stereoacuity in accommodative esotropia.
AB - PURPOSE: Despite successful optical realignment, many children with accommodative
esotropia (ET) have abnormal stereoacuity. In a prospective study, we examined
the influence of age of onset, age at alignment, duration of constant
misalignment, and accommodative convergence/accommodation ratio on random dot
stereoacuity outcomes in accommodative ET. METHODS: Participants were 111
consecutive children with accommodative ET. Random dot stereoacuity was measured
using the Randot preschool stereoacuity test, the Randot stereoacuity test, the
infant random dot stereoacuity cards, and the Lang 1. RESULTS: Age of onset has
only a minor influence on stereoacuity (P <.02); children with onset >/=age 25
months have better stereoacuity compared with children with an onset between ages
7 and 17 months. Age at alignment has a minor influence on stereoacuity (P
<.001); children with intermittent ET who have been treated have better
stereoacuity than children with a constant ET aligned between ages 6 and 24
months and after age 24 months. Duration of constant misalignment has the
strongest influence on stereoacuity (P <.001); children who had intermittent
misalignment or who had a constant misalignment of less than 4 months' duration
have better stereoacuity than patients who had a constant misalignment greater
than 4 months' duration. The accommodative convergence/accommodation ratio does
not influence stereoacuity outcomes (P >.10). CONCLUSIONS: Fine random dot
stereoacuity is associated with a constant misalignment of less than 4 months'
duration. These findings promote prompt and aggressive treatment of accommodative
ET at the onset of intermittent or constant misalignment.
PMID- 10675867
TI - The relationship between nystagmus and surgical outcome in congenital esotropia.
AB - PURPOSE: Congenital esotropia is often associated with congenital nystagmus. This
study examines the relationship between the presence of nystagmus and surgical
outcome in the treatment of patients with congenital esotropia. METHODS: In this
institutional retrospective study, we reviewed the charts of 200 consecutive
patients who underwent surgical correction for congenital esotropia between 1991
and 1995. Preoperative clinical characteristics and subsequent need for
additional strabismus surgery for a residual or consecutive deviation were noted.
Minimum follow-up was 6 months after the original operation. RESULTS: Of the 84
patients who met the inclusion criteria, 15 patients (18%) had latent or manifest
latent nystagmus, and 69 patients (82%) had no nystagmus. Eight of the 15
patients with nystagmus had or required reoperation according to our criteria
(53%). Nineteen of the 69 patients (28%) without nystagmus had or required
reoperation (P =.155). CONCLUSIONS: Nystagmus, when associated with congenital
esotropia, may increase the risk of requiring additional strabismus surgery for
residual or consecutive deviations. Appropriate and complete preoperative
counseling of patients with congenital esotropia who also have nystagmus should
include this increased risk.
PMID- 10675868
TI - Oculographic and clinical characterization of thirty-seven children with
anomalous head postures, nystagmus, and strabismus: the basis of a clinical
algorithm.
AB - BACKGROUND AND PURPOSE: We studied children with nystagmus who also had anomalous
head postures and strabismus to determine the etiology of the conditions and
present a diagnostic clinical algorithm. METHODS: The patients for this study
were among the 560 patients evaluated in the ocular motor neurophysiology
laboratory between the years 1991 and 1997. Clinical characteristics, infrared
oculography data, and medical and surgical treatments were entered into a
database for analysis. Oculography was performed on all patients according to a
standard protocol, and data were stored and analyzed off-line. Etiology of
anomalous head posture was determined with both clinical and oculography
information. RESULTS: Thirty-seven children are the subjects of this report. The
etiology of anomalous head posture was a "gaze null" due to congenital nystagmus
in 23 (62%) patients, an "adduction null" due to manifest latent nystagmus in 12
(32%) patients, spasmus nutans in 1 (3%) patient, and strabismus in 1 (3%)
patient. The patients' ages ranged from 9 months to 12 years and averaged 4.4
years. Sixty-nine percent were male patients. Nineteen (63%) of 30 patients had
abnormal recognition (linear optotype) acuity in at least 1 eye on monocular
cover; the recognition remained abnormal in 5 (17%) of 30 patients under
binocular conditions. Thirty percent of patients had amblyopia, 16% had some
structural disease of the eyes, 22% had some systemic syndrome or abnormality,
57% had a significant refractive error, and 27% had some ability to fuse.
CONCLUSIONS: The major etiology for anomalous head posture in these patients was
to adopt a gaze null due to congenital nystagmus (62% of patients) regardless of
the direction of their anomalous head posture or type of strabismus. Moving the
fixing eye as the first step for the anomalous head posture, combined with moving
the nonfixing eye for the resulting strabismus may help treat these patients.
PMID- 10675869
TI - Does primary intraocular lens implantation prevent "aphakic" glaucoma in
children?
AB - PURPOSE: Open-angle glaucoma may develop after surgery for congenital or
developmental cataract with an incidence ranging from 3% to 41%. The pathogenesis
of "aphakic" (open-angle) glaucoma remains unknown. Despite numerous reported
clinical series (>1000 eyes), we are unaware of any reported case of open-angle
glaucoma after primary intraocular lens (IOL) implantation for congenital or
developmental cataract. We decided to test the hypothesis that primary posterior
chamber IOL implantation might decrease the incidence of open-angle glaucoma in
children. METHODS: Pseudophakic eyes were collected from surgeons who contributed
data to a refractive study and who monitored intraocular pressure on a regular
basis. IOL implantation was commonly performed in eyes with a corneal diameter
>10 mm. Comparable primary data on aphakic eyes were included from 2 published
studies on aphakic glaucoma, which included corneal diameters and the patient's
age at surgery. Glaucoma-free survival estimates for each cohort were estimated.
RESULTS: Only 1 case of glaucoma was found among 377 eyes with primary
pseudophakia (mean age of patient, 5.1 +/- 4.7 years; mean follow-up, 3.9 +/- 2.7
years). There were 14 eyes (11.3%) with glaucoma among 124 aphakic eyes (mean age
of patient, 2.7 +/- 2.6 years; mean follow-up time, 7.2 +/- 3.9 years).
CONCLUSIONS: We report a decreased incidence of open-angle glaucoma among eyes
rendered primarily pseudophakic compared with those that remained aphakic after
cataract surgery. We propose 2 theories on the possible mechanism of reduction in
the incidence of glaucoma in pseudophakic eyes.
PMID- 10675870
TI - Heterochromia after pediatric cataract surgery.
AB - PURPOSE: Changes in iris color have been noted anecdotally after cataract surgery
in infants, but they have not been studied systematically. The mechanism for
these iris color changes has not previously been reported in the biomedical
literature. METHODS: Photographs were taken of both eyes of 15 children and 11
rhesus monkeys who had undergone unilateral cataract surgery. Masked examiners
reviewed the photographs and compared the iris color of the eyes that were
operated on with the eyes that were not operated on. Between 4 and 6 weeks
postoperatively, the level of prostaglandin F(2alpha) in the aqueous humor (n =
4) and vitreous humor (n = 2) was measured in both the operated and nonoperated
eyes of 4 monkeys that had undergone a neonatal lensectomy during the first 5
days of life. RESULTS: Thirteen of 15 children had a darker iris color in the
operated eye in relation to the nonoperated (control) eye. Four of 11 monkeys had
a uniformly darker iris in the operated eye; the other 7 monkeys had regional
darkening or patches of darker iris in the eye that was operated on. The
prostaglandin F(2alpha) levels in neonatal monkeys were higher in the aqueous
humor and in the vitreous humor of the operated eye in relation to the
nonoperated eye. CONCLUSION: In some children, cataract surgery is associated
with a darkening of the iris color in the operated eye. We speculate that this
darkening results from an exuberant prostaglandin release stimulated by the
cataract surgery and may occur through the same or a similar mechanism by which
latanoprost causes the darkening of iris color.
PMID- 10675871
TI - Management and complications of congenital dacryocele with concurrent intranasal
mucocele.
AB - INTRODUCTION: The association of dacryocele and intranasal mucocele has been
previously reported. Its incidence and optimal treatment are unknown. PATIENTS
AND METHODS: A retrospective review of 22 patients with 30 dacryoceles was
performed to determine the mean age at presentation, sex distribution, and
prevalence of associated intranasal mucocele, associated dacryocystitis, and
respiratory distress. The components of the examination, ancillary tests,
treatment modalities, and treatment outcomes were then summarized. RESULTS:
Unilateral dacryoceles were seen in 16 (73%) of the infants, and bilateral
dacryoceles were seen in 6 (27%) of the infants. Four (25%) of the 16 patients
who initially had unilateral dacryoceles later developed bilateral dacryoceles.
Dacryocystitis, preseptal cellulitis, or both were present on presentation or
developed in 18 (60%) of 30 dacryoceles. Nasal endoscopy was performed on 13
(59%) of 22 patients. Nasal examination with nasal speculum and headlight was
performed on 7 patients (32%). A concurrent intranasal mucocele was diagnosed in
23 (77%) of 30 dacryoceles. Respiratory distress arose in 5 (71%) of 7 patients
with bilateral intranasal mucoceles and in 2 (22%) of 9 patients with a
unilateral intranasal mucocele. Thirty-four procedures were performed. Seven
dacryoceles (21%) were treated with nasolacrimal duct probing under topical
anesthesia. Another one (3%) was treated with needle aspiration with later
definitive therapy. All other procedures were managed under general anesthesia.
These included 2 nasolacrimal duct probings (6%), 2 probings with silicone tube
placement (6%), 10 probings with intranasal mucocele marsupialization and
silicone tube placement (29%), and 12 probings with marsupialization alone (35%).
Two (29%) of the 7 probings performed under topical anesthesia failed, whereas
all other procedures were successful. One dacryocele spontaneously resolved.
CONCLUSIONS: Congenital dacryoceles are commonly associated with intranasal
mucoceles, dacryocystitis, and preseptal cellulitis. Respiratory distress is
common in bilateral cases. Bilateral nasolacrimal duct probing should be
considered in unilateral cases because of the high incidence of occult
contralateral involvement.
PMID- 10675872
TI - Is screening for primitive neuroectodermal tumors in patients with unilateral
retinoblastoma necessary?
AB - Retinoblastoma is the most common childhood intraocular tumor, occurring in 1 of
18,000 live births. Retinoblastoma may occur as a germinal mutation or a somatic
mutation. Forty percent of retinoblastoma cases are caused by a germline mutation
and include those patients with a positive family history of the disease.
Children with hereditary forms usually have multifocal, bilateral retinoblastoma,
whereas children with the somatic form have unilateral, unifocal disease.
However, up to 15% of cases of sporadic unilateral retinoblastoma may be
hereditary. It is important to recognize that this subgroup of unilateral
patients remains at risk for the development of second tumors as well as second
primary tumors of the intracranial midline, or "trilateral retinoblastoma." We
report a case of a 2-month-old child with unilateral retinoblastoma in whom
pinealoblastoma subsequently developed.
PMID- 10675873
TI - Anterior segment ischemia after strabismus surgery with microvascular dissection.
AB - Anterior segment ischemia is a rare but well-known complication of extraocular
muscle surgery.(1) Several surgical techniques have been used to prevent this
complication in high-risk patients. A number of studies have suggested that
microvascular dissection and preservation of the anterior ciliary vessels during
strabismus surgery may reduce the risk of ischemic complications. (2-4) We
present a case in which anterior segment ischemia occurred despite the use of
this vessel-sparing technique.
PMID- 10675874
TI - Strabismus surgery in children with Mobius syndrome.
AB - Mobius syndrome is a congenital disorder of facial diplegia associated with
lateral gaze paralysis. Although palsy of the sixth and seventh cranial nerves is
the minimum diagnostic finding for Mobius syndrome, neuropathologic evidence
indicates that this is a more complex syndrome.(1) Clinically, it is
characterized by a total absence of facial expression and severe esotropia. Other
anomalies may be associated with this syndrome, especially other cranial nerve
palsies and Poland syndrome. The etiology of this syndrome has not been clearly
established. Brain stem necrosis resulting from a vascular deficiency has been
offered as a possible pathogenetic explanation.(2) The strabismus in Mobius
syndrome is congenital esotropia with bilateral limitation in abduction. Even
though many reports have described the various features of Mobius syndrome, only
a few articles have reported the results of strabismus surgery in children,
including bimedial rectus muscle recession. (3-5) Some authors report that
bilateral medial rectus muscle recession alone has been disappointing; therefore,
a combination of a medial rectus muscle recession and a lateral rectus muscle
resection was recommended for satisfactory results. (5-7) In more severe cases,
muscle transposition was needed to ensure straight position of the eyes in
primary gaze. (8-9)
PMID- 10675875
TI - Postoperative intraocular pressure elevation after the use of Healon GV in
pediatric cataract surgery.
AB - Intraocular pressure elevation after the use of viscoelastic agents in
uncomplicated cataract surgery has been well documented in adults. However,
pediatric patients are thought to clear residual viscoelastic agents from the
anterior chamber more easily than adults, presumably because of healthier
trabecular meshwork. (1) We report on a series of 4 eyes of 4 children with
previously normal intraocular pressure who underwent cataract extraction with
primary (3 patients) or secondary (1 patient) intraocular lens implantation with
Healon GV, which was complicated by marked postoperative intraocular pressure
elevation (greater than 30 mm Hg). The patients, aged 5 to 14 years, had an
intraocular pressure ranging from 34 to 50 mm Hg with Tonopen or applanation
tonometry 1 day, postoperatively associated with nausea, eye pain, and
microcystic corneal edema. Viscoelastic material was not entirely removed during
surgery. Each of these cases occurred after a change in our preferred
viscoelastic agent from one with less viscosity to Healon GV. Medical management
controlled the elevated intraocular pressure in all cases without affecting the
visual outcome. However, 1 patient with intractable nausea and vomiting required
hospitalization for rehydration. With meticulous removal of all viscoelastic
material at the completion of surgery, we have not documented any additional
cases of postoperative pressure elevation.
PMID- 10675877
TI - Reply
PMID- 10675876
TI - Congenital nystagmus: In search of simplicity on the other side of complexity.
PMID- 10675879
TI - A Boston T party - The highlights.
PMID- 10675878
TI - 'Cleaning' autologous bone marrow transplants with E. coli toxin.
PMID- 10675881
TI - Histamine control of sleep, learning and memory.
PMID- 10675880
TI - RNA as a small-molecule drug target - Letter to the Editor.
PMID- 10675883
TI - Conopeptides: From deadly venoms to novel therapeutics.
AB - Marine cone snails have developed many distinct venoms that contain biologically
active peptides as part of an envenomation survival strategy for feeding and
defense. These peptides, known as conopeptides, have been optimized through
evolution to target specific ion channels and receptors with very high affinities
and selectivities. Side effects of currently available therapies often arise from
their lack of selectivity between pharmacologically relevant targets and targets
that have a similar structure but different function. As conopeptides can be
highly selective between closely related receptor subtypes, they could meet
specific therapeutic needs with a reduced likelihood of side effects.
PMID- 10675884
TI - Integrated bacterial genomics for the discovery of novel antimicrobials.
AB - Sequencing of bacterial genomes has been progressing with breathtaking speed.
Currently, the genomes of 23 bacterial species are sequenced, with approximately
40 more sequencing projects in progress. Industrial research is now facing the
challenge of translating this information efficiently into drug discovery. This
review will summarize the impact of bacterial genomics, bioinformatics and second
generation genomic technologies on target identification, assay development, lead
optimization and compound characterization.
PMID- 10675885
TI - Stress proteins as targets for anti-inflammatory therapies.
AB - Microbial heat shock proteins (HSPs) are ubiquitous and highly immunogenic. In
healthy humans, B- and T-cells with specificity for self-HSP can be easily
detected. In patients with chronic inflammatory diseases, raised levels of
antibodies and T-cells with reactivity to self-HSP have been observed. Based on
this and other evidence, this raised immune reactivity might be the result of
stress-induced upregulation of self-HSP during inflammation and is possibly
caused by tissue destruction. More importantly, immunization with conserved
sequences of microbial-HSP increases resistance to the induction of autoimmune
disease. Together, it appears that immune reactivity directed towards self-HSP
can be part of a regulatory immune effector mechanism that contributes to
maintenance of self-tolerance and has anti-inflammatory activity. Boosting of
such anti-inflammatory effector mechanisms by artificial immunization offers
attractive immunotherapeutic possibilities.
PMID- 10675886
TI - Monitor: molecules and profiles.
AB - Monitor provides an insight into the latest developments in drug discovery
through brief synopses of recent presentations and publications together with
expert commentaries on the latest technologies. There are two sections: Molecules
summarizes the chemistry and the pharmacological significance and biological
relevance of new molecules reported in the literature and on the conference
scene; Profiles offers commentary on promising lines of research, emerging
molecular targets, novel technology, advances in synthetic and separation
techniques and legislative issues.
PMID- 10675887
TI - Combinatorial chemistry.
PMID- 10675888
TI - A genome analysis production line.
PMID- 10675889
TI - Genetic defects of the growth hormone-insulin-like growth factor axis.
AB - Our understanding of the physiology of the growth hormone-insulin-like growth
factor (GH-IGF) axis has been characterized by remarkable advances in the past
decade, with clarification of genetic defects in the development of somatotropes,
GH secretion and action, and IGF synthesis and action. Combined efforts of
research in this area and the development of animal models of growth retardation
have also indicated new genetic abnormalities that might prove to cause short
stature in humans. Genetic defects, both established and hypothetical, are
reviewed, and a pragmatic clinical approach to the genetic investigation of short
statured patients is presented.
PMID- 10675890
TI - Do cytoskeletal components control fatty acid translocation into liver
mitochondria?
AB - For two decades it has been assumed that inhibition of carnitine
palmitoyltransferase I (CPT-I) by malonyl-CoA represents the main regulatory
mechanism of liver ketogenesis. However, recent evidence indicates that CPT-I
activity is also controlled by interactions between mitochondria and cytoskeletal
components. This newly recognized mechanism emphasizes the emerging role of the
cytoskeleton in the regulation of metabolic pathways.
PMID- 10675891
TI - The new human kallikrein gene family: implications in carcinogenesis.
AB - The traditional human kallikrein gene family consists of three genes, namely KLK1
[encoding human kallikrein 1 (hK1) or pancreatic/renal kallikrein], KLK2
(encoding hK2, previously known as human glandular kallikrein 1) and KLK3
[encoding hK3 or prostate-specific antigen (PSA)]. KLK2 and KLK3 have important
applications in prostate cancer diagnostics and, more recently, in breast cancer
diagnostics. During the past two to three years, new putative members of the
human kallikrein gene family have been identified, including the PRSSL1 gene
[encoding normal epithelial cell-specific 1 gene (NES1)], the gene encoding
zyme/protease M/neurosin, the gene encoding prostase/KLK-L1, and the genes
encoding neuropsin, stratum corneum chymotryptic enzyme and trypsin-like serine
protease. Another five putative kallikrein genes, provisionally named KLK-L2, KLK
L3, KLK-L4, KLK-L5 and KLK-L6, have also been identified. Many of the newly
identified kallikrein-like genes are regulated by steroid hormones, and a few
kallikreins (NES1, protease M, PSA) are known to be downregulated in breast and
possibly other cancers. NES1 appears to be a novel breast cancer tumor suppressor
protein and PSA a potent inhibitor of angiogenesis. This brief review summarizes
recent developments and possible applications of the newly defined and expanded
human kallikrein gene locus.
PMID- 10675892
TI - Newer agents for hormonal contraception in the male.
AB - Efforts to create a hormonal contraceptive for men use testosterone to suppress
the production of pituitary gonadotropins and, hence, spermatogenesis. However,
conventional testosterone must be administered by frequent injection, and when
given alone, is not 100% effective. Therefore, newer androgens and agents that
synergistically suppress gonadotropin production are being studied to create an
effective and commercially viable contraceptive.
PMID- 10675893
TI - Answering the question: 'why did biocatalysis in organic media not take off in
the 1930s?'.
PMID- 10675894
TI - Response from kvittingen
PMID- 10675895
TI - On the optimization of classes for the assignment of unidentified reading frames
in functional genomics programmes: the need for machine learning.
AB - At present, the assignment of function to novel genes uncovered by the systematic
genome-sequencing programmes is a problem. Many studies anticipate that this can
be achieved by analysing patterns of gene expression via the transcriptome,
proteome and metabolome. Thus, functional genomics is, in part, an exercise in
pattern classification. Because many genes have known functional classes, the
problem of predicting their functional class is a supervised learning problem.
However, most pattern classification methods that have been applied to the
problem have been unsupervised clustering methods. Consequently, the best
classification tools have not always been used. Furthermore, the present
functional classes are suboptimal and new unsupervised clustering methods are
needed to improve them. Better-structured functional classes will facilitate the
prediction of biochemically testable functions.
PMID- 10675896
TI - Transgene-mediated modifications to animal biochemistry.
AB - The application of gene-transfer technology to domestic animals provides a way
for the introduction of genes encoding biochemical pathways that are currently
nonfunctional in these animals. This might provide a mechanism for increasing the
availability of specific substrates that currently limit certain production
characteristics, such as the production of wool. The progress and problems
associated with recent attempts to transfer a cysteine biosynthetic pathway and a
glyoxylate cycle to sheep are discussed, in addition to the extension of this
concept to other biochemical pathways.
PMID- 10675897
TI - Cold-adapted enzymes: from fundamentals to biotechnology.
AB - Psychrophilic enzymes produced by cold-adapted microorganisms display a high
catalytic efficiency and are most often, if not always, associated with high
thermosensitivity. Using X-ray crystallography, these properties are beginning to
become understood, and the rules governing their adaptation to cold appear to be
relatively diverse. The application of these enzymes offers considerable
potential to the biotechnology industry, for example, in the detergent and food
industries, for the production of fine chemicals and in bioremediation processes.
PMID- 10675898
TI - Simulated moving-bed chromatography and its application to chirotechnology.
AB - The increased awareness of the differences in biological activity of the two
enantiomers of a chiral drug has raised the demand for enantiomerically pure
products, particularly in the pharmaceutical industry. Simulated moving-bed
chromatography can be used for the separation of the two enantiomers of a chiral
molecule, which is feasible at all production scales, from laboratory to pilot to
production plant. The use of non-enantioselective synthesis of racemic mixtures
and simulated moving-bed enantiomer separation might make the development process
of a new chiral drug substantially shorter and cheaper.
PMID- 10675899
TI - Gene therapy: the first decade.
AB - Gene therapy promises to revolutionize medicine by treating the causes of disease
rather than the symptoms. We are nearing the end of the first decade of gene
therapy, and this article summarizes the approaches taken, results achieved,
lessons learned and important recent developments. The early results on the
clinical efficacy of gene therapies were disappointing, largely because the
available gene-transfer vectors proved to be inadequate. Recently, however,
clinical benefit has been clearly demonstrated and great progress made in
selecting and improving vectors. There is now every prospect that the second
decade will see gene therapy live up to its enormous potential.
PMID- 10675900
TI - Regulation of endocytic traffic by rho family GTPases.
AB - Endocytosis is a complicated yet highly efficient process that involves the
uptake and processing of cargoes, ranging from small molecules, to activated
signalling receptors, to whole microorganisms. Regulation of endocytic pathways
is poorly understood. Recent evidence suggests that the Rho GTPase family of
signalling proteins is intimately involved in endocytic traffic, providing novel
insights into the control mechanisms that govern this process.
PMID- 10675901
TI - Germ cell cytonemes?
PMID- 10675902
TI - Searching for a function for nuclear actin.
AB - The abundant cytoskeletal protein actin has numerous cytoplasmic roles. Although
there are many reports of the presence of actin in the nucleus, in general they
have been discounted as artifactual. However, recent work has begun to provide
evidence for important roles for actin in nuclear processes ranging from
chromatin remodelling to splicing. In addition, several regulators of actin
polymerization are localized to the nucleus or translocate to the nucleus in a
regulated manner, suggesting that there is some function of actin in the nucleus
that is subject to regulation. This review discusses the evidence for actin in
the nucleus and summarizes recent work suggesting that actin or actin-related
proteins are involved in the regulation of nuclear processes such as chromatin
remodelling.
PMID- 10675903
TI - Protein-only inheritance in yeast: something to get [PSI+]-ched about.
AB - Recent work suggests that two unrelated phenotypes, [PSI+] and [URE3], in the
yeast Saccharomyces cerevisiae are transmitted by non-covalent changes in the
physical states of their protein determinants, Sup35p and Ure2p, rather than by
changes in the genes that encode these proteins. The mechanism by which
alternative protein states are self-propagating is the key to understanding how
proteins function as elements of epigenetic inheritance. Here, we focus on recent
molecular-genetic analysis of the inheritance of the [PSI+] factor of S.
cerevisiae. Insights into this process might be extendable to a group of
mammalian diseases (the amyloidoses), which are also believed to be a
manifestation of self-perpetuating changes in protein conformation.
PMID- 10675904
TI - Association of STATs with relatives and friends.
AB - Members of the STAT family of transcription factors are present in species as
diverse as mammals, insects and slime molds. Discovered as mediators of
interferon-induced signals, the STATs were later shown to drive many different
ligand-induced responses through receptor-induced tyrosine phosphorylation and
dimerization. STAT1 also functions as a transcription factor, essential for the
efficient constitutive expression of certain genes, without needing tyrosine
phosphorylation, and phosphorylated STAT1 dimers mediate suppression - rather
than activation - of some genes. STATs are present in the cytoplasm of untreated
cells in multiprotein complexes, which might aid in their nuclear translocation
and differential binding to DNA, thus contributing to the specificity of STAT
action. This review explores the diverse protein-protein interactions that
underlie the multiple functions of the STATs.
PMID- 10675905
TI - Integrin signalling: a new Cas(t) of characters enters the stage.
AB - Cellular morphology is determined by the organization of the intracellular actin
cytoskeleton, which is influenced by external and internal cues. Focal adhesions
are sites at which the actin cytoskeleton is linked to the extracellular matrix
by integrin receptor complexes. In addition to providing structural tethering
points for cells, integrin receptor complexes transduce signals that influence a
broad range of cellular processes, including migration, proliferation,
transformation and apoptosis. The Cas proteins (p130Cas, HEF1/Cas-L and Efs/Sin),
a family of docking proteins containing multiple interaction domains, are
important components of integrin receptor signalling and have been implicated in
all of these processes.
PMID- 10675907
TI - Careers-perspective interview.
PMID- 10675906
TI - Interaction blues: protein interactions monitored in live mammalian cells by beta
galactosidase complementation.
PMID- 10675908
TI - The neurobiology of duchenne muscular dystrophy: learning lessons from muscle?
AB - Several forms of inherited muscular dystrophy are associated with brain
abnormalities and cognitive impairment. One of the most common and severe of
these diseases is Duchenne muscular dystrophy (DMD). Dystrophin, the product of
the DMD gene, is found in neurones, where it is associated with the postsynaptic
membrane. Cognitive impairment in individuals with DMD is thought to be due to an
abnormality in the neuronal membrane that is caused by lack of dystrophin. Recent
experimental evidence has provided valuable clues in our understanding of the
complex molecular neurobiology of muscular dystrophy.
PMID- 10675909
TI - Cell birth, cell death, cell diversity and DNA breaks: how do they all fit
together?
AB - Substantial death of migrating and differentiating neurons occurs within the
developing CNS of mice that are deficient in genes required for repair of double
stranded DNA breaks. These findings suggest that large-scale, yet previously
unrecognized, double-stranded DNA breaks occur normally in early postmitotic and
differentiating neurons. Moreover, they imply that cell death occurs if the
breaks are not repaired. The cause and natural function of such breaks remains a
mystery; however, their occurrence has significant implications. They might be
detected by histological methods that are sensitive to DNA fragmentation and
mistakenly interpreted to indicate cell death when no relationship exists. In a
broader context, there is now renewed speculation that DNA recombination might be
occurring during neuronal development, similar to DNA recombination in developing
lymphocytes. If this is true, the target gene(s) of recombination and their
significance remain to be determined.
PMID- 10675910
TI - Unveiling synaptic plasticity: a new graphical and analytical approach.
AB - Short-term synaptic plasticity has a key role in information processing in the
CNS, whereas memories can be formed through long-lasting changes in synaptic
strength. Despite the importance of these phenomena, it remains difficult to
determine whether a synaptic modulation is expressed at a presynaptic or
postsynaptic site. This article describes a new approach that, in its simplest
form, can identify the site of expression by direct graphical means. A more
sophisticated form of the technique can quantify functional synaptic properties
and determine which of these properties is altered following a modulation of
synaptic strength.
PMID- 10675911
TI - Peptide hormones and neuropeptides: birds of a feather.
PMID- 10675912
TI - What is a neuropeptide?
PMID- 10675913
TI - Reply to de Wied and Kastin.
PMID- 10675914
TI - Immunization with beta-amyloid: could T-cell activation have a harmful effect?
PMID- 10675915
TI - Cross-modal reorganization of human cortical functions.
AB - Recent technological development has opened fascinating opportunities in research
on cognitive functions of the human brain. For example, cortical representations
of sensory functions and their reorganization, which have been studied thoroughly
in animals, are far better understood in humans now than they were only a decade
ago. Hemodynamic and electromagnetic studies have demonstrated that a modality
specific brain area that is totally deprived of its normal sensory input becomes
responsive to stimulation of other modalities. The functional significance of
this cross-modal activation was recently indicated by, for example, studies
showing that the occipital cortex of the blind is activated by sound changes,
when the task is to detect these changes. Moreover, trans-cranial magnetic
stimulation applied to the occipital cortex of blind individuals results in
distortions and omissions of letters in Braille text being read by the subject.
Contrary to prevailing views, cross-modal neural reorganization might, as shown
by recent results, take place even in the mature human brain.
PMID- 10675916
TI - Acetylcholine-mediated modulation of striatal function.
AB - Striatal spiny neurones serve as a major anatomical locus for the relay of
cortical information flow through the basal ganglia. these projection neurones
also represent the main synaptic target of cholinergic interneurones, whose
physiological role in striatal activity still remains largely enigmatic. The
striatal cholinergic system has been implicated in the pathophysiology of
movement disorders such as Parkinson's disease, but the cellular mechanisms
underlying cholinergic-neurone function are still unknown. On the basis of in
vitro electrophysiological evidence, obtained from a rat corticostriatal-slice
preparation, we propose that endogenous ACh exerts a complex modulation of
striatal synaptic transmission, which produces both short-term and long-term
effects. ACh-mediated mechanisms might be of crucial importance in processing the
cortical inputs to the striatum.
PMID- 10675917
TI - The origin and migration of cortical neurones: new vistas.
AB - The principal neuronal types of the cerebral cortex are the excitatory pyramidal
cells, which project to distant targets, and the inhibitory nonpyramidal cells,
which are the cortical interneurones. This article reviews evidence suggesting
that these two neuronal types are generated in distinct proliferative zones.
Pyramidal cells are derived from the neuroepithelium in the cortical ventricular
zone, and use the processes of radial glia in order to migrate and take their
positions in the cortex in an 'inside-out' sequence. Relatively few nonpyramidal
cells are generated in the cortical neuroepithelium: the majority is derived from
the ganglionic eminence of the ventral telencephalon. These nonpyramidal neurones
use tangential migratory paths to reach the cortex, probably travelling along
axonal bundles of the developing corticofugal fibre system.
PMID- 10675919
TI - Rarity and diversity in Amazonian forest trees.
PMID- 10675918
TI - Channel noise in neurons.
AB - The probabilistic gating of voltage-dependent ion channels is a source of
electrical 'channel noise' in neurons. This noise has long been implicated in
limiting the reliability (repeatability) of neuronal responses to repeated
presentations of identical stimuli. More recently, it has been shown to increase
the range of spiking behaviors exhibited in some neural populations. Channel
numbers are tied to metabolic efficiency and the stability of resting potential,
and channel noise might be exploited by future cochlear implants in order to
improve the temporal representation of sound.
PMID- 10675921
TI - How the locust got its stripes: the evolution of density-dependant aposematism.
PMID- 10675920
TI - Testosterone and maternal effects - integrating mechanisms and function.
PMID- 10675922
TI - The calculus of biodiversity: integrating phylogeny and conservation.
PMID- 10675923
TI - Transposable elements and host genome evolution.
AB - Several recent reports have challenged the idea that transposable elements (TEs)
are mainly 'selfish' or 'junk' DNA with little importance for host evolution. It
has been proposed that TEs have the potential to provide host genomes with the
ability to enhance their own evolution. They might also be a major source of
genetic diversity, allowing response to environmental changes. Because the
relationships between TEs and host genomes are highly variable, and because the
selfish, junk and beneficial DNA hypotheses are by no means mutually exclusive, a
single label for these relationships appears to be inappropriate and potentially
misleading.
PMID- 10675924
TI - Evolutionary consequences of dating the Yixian Formation.
AB - The Yixian Formation of northeastern China has yielded important new fossils that
are fuelling debates on the origin of angiosperms, on the early radiation of
birds and of mammals, and on the origin of feathers. Although these fossils
provide a wealth of detailed anatomical information, knowledge of the absolute
age of the Yixian Formation is crucial if we are to understand their true
evolutionary significance. The age of the Yixian Formation has been disputed, but
recent evidence provides strong support for an Early Cretaceous rather than a
Late Jurassic age.
PMID- 10675925
TI - Colonization and diversification: towards a phylogeographic synthesis for the
Canary Islands.
AB - Recently, the Canary Islands have become a focus for studies of the colonization
and the diversification of different organisms. Some authors have considered
Canarian endemisms as relicts of Tertiary origin, but new molecular data suggest
a general pattern of continental dispersion followed by in situ speciation.
Recent phylogeographic studies are revealing variants of the simple stepping
stone colonization model that seems to hold for many Hawaiian groups. Many
factors can generate deviations from such a pattern: the stochastic nature of
colonization, competitive exclusion, phylogenetic constraints on adaptive
evolution and extinction. An understanding of island colonization and
diversification can best be developed from an ecosystem level synthesis as more
data for the Canarian archipelago come to hand.
PMID- 10675926
TI - Recreating ancestral proteins.
AB - Tracing the history of molecular changes using phylogenetic methods can provide
powerful insights into how and why molecules work the way they do. It is now
possible to recreate inferred ancestral proteins in the laboratory and study the
function of these molecules. This provides a unique opportunity to study the
paths and the mechanisms of functional change during molecular evolution. What
insights have already emerged from such phylogenetic studies of protein evolution
and function, what are the impediments to progress and what are the prospects for
the future?
PMID- 10675927
TI - A consistent equation for ecological sensitivity in matrix population analysis.
PMID- 10675928
TI - Reply from T. Benton and A. Grant.
PMID- 10675930
TI - Reply from G. Bernasconi and J.E. Strassmann.
PMID- 10675929
TI - From the laboratory to the field: the advantage of pleometrotic colony founding.
PMID- 10675931
TI - Jensen's inequality and optimal life history strategies in stochastic
environments.
PMID- 10675932
TI - Early tetrapod evolution.
AB - Tetrapods include the only fully terrestrial vertebrates, but they also include
many amphibious, aquatic and flying groups. They occupy the highest levels of the
food chain on land and in aquatic environments. Tetrapod evolution has generated
great interest, but the earliest phases of their history are poorly understood.
Recent studies have questioned long-accepted hypotheses about the origin of the
pentadactyl limb, the phylogeny of tetrapods and the environment in which the
first tetrapods lived.
PMID- 10675933
TI - [Acute acromioclavicular dislocations].
AB - Acromioclavicular dislocations represent over 10% of acute traumatic injuries to
the shoulder girdle. The mechanism is usually a direct impact on the shoulder
with the arm in adduction, producing rupture of the acromioclavicular (AC)
ligaments, then of the coracoclavicular (CC) ligament, with displacement of the
lateral end of the clavicle. Rockwood described 6 grades of injury. Physical
examination usually provides the diagnosis, which is confirmed by radiological
examination. X-rays centered on the AC joint, if necessary with forceful
adduction of both shoulders or under traction, are useful to evaluate the
severity of the lesion. Grade I and II lesions are usually treated conservatively
by simply immobilizing the arm for 3 to 4 weeks. Surgical treatment is usually
advocated for grade IV, V and VI lesions: AC or CC fixation, sometimes associated
with ligament repair, depending on the surgeons. AC pinning or C-C screw fixation
are the techniques most often used. Management of grade III lesions remains
controversial. Some authors advocate immediate surgical treatment in young,
active patients, in heavy laborers and even in slender individuals. The choice of
the operative technique is controversial, as no single technique has clearly
proved to be superior to others. Other authors advocate conservative treatment,
which gives functional results which patients consider quite acceptable, with
faster recovery; patients should be informed that results are essentially
similar, whatever the treatment. The possibility of performing secondary
operations with good results in cases with failure of conservative management is
a further argument in favor of applying conservative therapy first in acute
injuries.
PMID- 10675934
TI - Elbow instability.
AB - An understanding of elbow instability is predicated on knowledge of the anatomy
of the lateral collateral ligament complex and of the mechanism and kinematics of
elbow subluxation and dislocation. The lateral collateral ligament complex is the
key structure involved in recurrent elbow instability and it is virtually always
disrupted in elbow dislocations that result from a fall. The ulnar part of the
lateral collateral ligament complex (also known as lateral ulnar collateral
ligament) is the critical portion of the ligament complex securing the ulna to
the humerus and preventing posterolateral rotatory instability. The kinematics of
elbow subluxation and dislocation are a three dimensional coupled motion referred
to as posterolateral rotatory instability in which the forearm rotates off the
humerus in valgus/external rotation during flexion from the extended position.
Elbow instability is diagnosed on clinical examination by the lateral pivot-shift
test, the posterolateral rotatory apprehension and drawer tests and on
radiographic examination by performing stress x-rays. While the lateral pivot
shift test is difficult to perform, the posterolateral rotatory drawer test is
much less difficult. The most sensitive test, however, is the posterolateral
rotatory apprehension test. A positive apprehension test in a patient presenting
with a history of recurrent painful clicking, snapping, clucking, or locking of
the elbow should lead one directly to the suspected diagnosis of posterolateral
rotatory instability. Treatment is surgical, by repair or reconstruction of the
lateral collateral ligament complex, specifically the ulnar part. Deficiencies of
the coronoid and/or radial head must be addressed.
PMID- 10675935
TI - Ulnar variance and its relationship to ligament injuries of the wrist.
AB - An anatomic study on cadavers and a clinico-radiological study on patients were
undertaken to verify if ligament injuries of the wrist could be associated with
ulnar variance. Neither scapholunate nor triquetrolunate ligament injuries could
be related to shorter or longer ulnae. Longer ulnae were associated with
significantly more perforations of the triangular fibrocartilage complex (TFCC).
PMID- 10675936
TI - Intracarpal ligamentous lesions associated with fractures of the distal radius:
outcome at one year. A prospective study of 95 cases.
AB - Intracarpal ligamentous lesions associated with fractures of the distal radius
(FDR) are frequent. The prevalence of these lesions has been assessed either by
arthrography or by arthroscopy, but their outcome remains unknown. We carried out
a radiographic study to assess the incidence of intracarpal ligamentous lesions
with scapholunate (SL) and/or lunotriquetral (LT) dissociation and their outcome
at one year. These lesions were termed "dissociative ligamentous lesions" (DLL).
This prospective series consisted of 102 consecutive FDR's. The initial x-rays,
immediate postoperative x-rays and x-rays at 1 year were studied. We studied the
relationships of the bones of the first carpal row, abnormal joint space
widening, Gilula's lines and the values of the intracarpal angles. The evolution
of the carpal height ratio between day 0 and one year was studied. Complete xrays
were available for 95 patients. There were 9 epiphyseal, 45 metaphyseal and 41
mixed fractures. DLL's were diagnosed in the early stages in 40 patients. There
were 29 isolated SL lesions, 2 isolated LT lesions and 9 cases of associated SL
and LT lesions. At 1 year, the diagnosis was confirmed in all these cases but a
further case of SL dissociation was diagnosed. At 1 year, 61% of DLL's showed
significant loss of carpal height and were considered as progressive. There was
an association between the type of fracture and the presence or absence of DLL (p
= 0.02). This study, based on radiographic analysis alone, showed 43% DLL's. The
majority could be identified immediately. These findings are similar to those in
recent arthrographic or arthroscopic studies, but the interest of plain
radiographic study is to diagnose only those lesions having a definite effect on
the carpus ("static instability"). At 1 year, 61% of lesions diagnosed have
significantly affected carpal height.
PMID- 10675937
TI - Soft tissue stabilization in the management of chronic scapholunate instability
without osteoarthritis. A 15-year series.
AB - Management of chronic scapholunate instability without osteoarthritis remains
controversial. Some surgeons favor partial wrist arthrodesis; others, soft tissue
stabilization. Many techniques for soft tissue repair have been described but
with few or unpredictable results. We reviewed all our cases of scapholunate
instability without osteoarthritis treated by soft tissue stabilization. Since
1979, 37 soft tissue stabilization procedures have been performed to correct
dynamic (25) or static (12) scapholunate instability without osteoarthritis. The
average time from injury to surgical treatment was 7.2 mos. (range 0.25 to 36
mos.). Three cases were treated within the first month of injury. The choice of
repair was determined intraoperatively. The scaphoid shift must be easily
reducible to make the case eligible for soft tissue repair. The scapholunate
ligament was usually disrupted from palmar to dorsal, and the average amount of
disruption was 74%. When scapholunate ligament remnants were of sufficient
quality, secondary repair was performed; but if not, ligament reconstruction
using tendon grafts or capsulodesis was performed. The procedures used were
secondary ligamentous repair in 16 (by direct suture, reinsertion using anchor
and/or transosseous reattachment), ligament reconstruction using tendon grafts in
6, capsulodesis in 7 and a combination of these procedures in 8. The mean follow
up was 27 mos. (range 2 to 62 mos.). Postoperatively, there was an 83% decrease
in pain. The average wrist motion was 60 degrees extension, 47 degrees flexion,
18 degrees radial deviation and 28 degrees ulnar deviation (92%, 84%, 106% and
88% of preoperative values and 88%, 75%, 78% and 76% of the uninvolved wrists,
respectively), and the grip strength was 28 kg (117% of preoperative value and
78% of the uninvolved wrists). On roentgenograms, the mean static scapholunate
distance was 4.2 mm (a 26% loss of reduction compared to the early postoperative
gap), but scapholunate and radiolunate angles were within normal values (58
degrees and 9 degrees, respectively). At follow-up, one patient presenting a
small zone of chondromalacia on the scaphoid at the time of secondary ligamentous
repair developed severe radioscaphoid arthritis 15 months postoperatively. The
results were further assessed according to the form of instability, delay before
surgery, severity of disruption and type of repair. Patients with static
instability showed worse clinical and radiological findings than those with
dynamic instability. Surgical delay did not influence the outcome. The more
severe the ligament disruption was, the poorer were the results. All types of
repair had a comparable outcome except those treated by ligament reconstruction
using tendon grafts. The results in the latter group were unsatisfactory in terms
of motion, grip strength and radiological findings. This technique has been
abandoned by the group. In conclusion, soft tissue stabilization is part of the
armamentarium in the management of reducible chronic scapholunate instability
without osteoarthritis. Ligament reconstruction using tendon grafts gave, in our
hands, unsatisfactory results. Otherwise, all types of repair achieved a
relatively pain-free wrist, with acceptable motion, grip strength, scapholunate
and radiolunate angles but with a wider than normal static scapholunate distance.
A longer follow-up is needed to assess the effect of this abnormal gap. Factors
that favorably affected the outcome were: dynamic type of instability and partial
disruption of the ligament.
PMID- 10675938
TI - Blatt dorsal capsulodesis for scapholunate instability.
AB - This retrospective series reviews 17 patients with scapholunate instability
treated with the Blatt procedure between 1994 and 1997. Indications were 11 cases
of preradiographic instability, three dynamic and three static instabilities.
Subjective and objective assessment was carried out. Average pain and level of
activity score was 60.8/80 (good). Only three patients failed to continue their
jobs. Ten patients were fully satisfied, and seven had minor to major
reservations. Flexion loss averaged 11 degrees and extension loss was 11.3
degrees. Grip force improved significantly by 11.2 kg. Associated scapholunate
interosseous ligament repair in 6 patients resulted in no further improvement.
Major complications were deep infection (one case) and reflex sympathetic
dystrophy (two cases). Given the lack of a superior procedure, we considered the
Blatt capsulodesis a valuable therapeutic option for cases of preradiographic and
dynamic instability, or as an adjunct to scapholunate interosseous ligament
repair in more acute lesions.
PMID- 10675939
TI - The skier's thumb.
AB - The incidence of skier's thumb (rupture of the ulnar collateral ligament of the
first metacarpophalangeal joint) is increasing. To determine whether conservative
or surgical treatment is indicated, ultrasound (US) and magnetic resonance
imaging (MRI) have been advocated in the last few years. Surgery should be
performed in the case of an unstable joint with a ligamentous tear or in the
presence of a displaced bony fragment. Several techniques for surgical repair in
acute and old ruptures are proposed. Conservative and postoperative treatment
consists of immobilization of the joint in a splint or thumb spica cast for 4
weeks. The best results are obtained in bony avulsion fractures. Conservative
treatment of lesions requiring surgical treatment may result in permanent
disability of the joint; thus, correct diagnosis is mandatory.
PMID- 10675940
TI - Arthroscopy of the shoulder. Current concepts review.
AB - Arthroscopy of the shoulder has become much more common in the past decade as
surgeons have developed proficiency with the arthroscope in the knee and
appropriate instrumentation has been developed. In recent years arthroscopic
techniques adapted to the shoulder have continued to evolve from a diagnostic to
a treatment-oriented modality. It is now recognized and accepted as both a
diagnostic and therapeutic technique in orthopedic surgery. A thorough knowledge
of the anatomy, disorders, arthroscopic variations and pathological findings is
essential to successfully perform the procedure. This paper discusses the
operating room set-up, the portal placement and the indications for arthroscopy
of the shoulder.
PMID- 10675941
TI - Diagnosis and treatment of acute ruptures of the Achilles tendon. Current
concepts review.
AB - Subcutaneous rupture of the Achilles tendon seems to have become more common in
recent years. This results from a combination of more awareness in the medical
field and greater participation in physical activities by the general population.
The causes of Achilles tendon rupture are multifactorial and still unclear. The
diagnosis can be made based on physical examination; special diagnostic studies
are rarely necessary. The literature on ruptures of the Achilles tendon and
associated treatment has expanded over the past decade. The lack of a universal,
consistent protocol for subjective and objective evaluation following treatment
of Achilles tendon rupture has prevented any comparison of results. There is
still controversy concerning the best treatment. From a literature review, it
appears that a satisfactory outcome may be achieved with either nonoperative or
operative treatment but surgical repair appears to provide better functional
capacity. Lower rerupture rates and slightly improved strength and functional
ability may be expected with surgical treatment; however, the rate of minor
complications is higher than with nonoperative treatment. Reports in the
literature indicate that in active, young, very demanding individuals, surgical
repair should be considered, with nonsurgical treatment reserved for elderly or
sedentary patients. There is no single, uniformly accepted surgical technique for
Achilles tendon repair. Most acute ruptures have been treated successfully with
simple end-to-end suture, although various augmentation procedures have been
combined with simple suture with satisfactory outcomes. To minimize the
complications typically associated with open surgery, percutaneous techniques to
repair the ruptured Achilles tendon have been advocated, and the results are
reported to be promising, although not without failures and complications.
Several recent studies have reported functional benefits of early postoperative
tendon mobilization in well-motivated patients, since treatment results are
determined not only by the method of repair but also, and perhaps more
importantly, by the early postoperative functional rehabilitation.
PMID- 10675942
TI - Mechanisms of retrolisthesis in the lower lumbar spine. A radiographic study.
AB - The study investigates lower lumbar segments with posterior vertebral shifts
(retrolisthesis) with respect to the orientation of facet joints, disc height,
lordosis of the lumbar spine, and orientation of vertebral endplates. Standing
lumbar radiographs as well as CT and/or MRI investigations of 69 patients were
analyzed. Data from patients with retrolisthesis (20 cases) were compared to data
from patients with degenerative spondylolisthesis (DS, 23 cases), and from
patients without signs of vertebral shifts (26 cases). The orientation of facet
joints in segments with retrolisthesis was not different from segments without
shifts, whereas the facet joints in patients with DS were oriented more
sagittally. The overall lordosis of the lumbar spine and the endplate inclination
were considerably reduced in patients with retrolisthesis, especially compared to
those with DS. Disc height was comparable in retrolisthesis and DS, but was
reduced compared to segments without shifts. The results support biomechanical
considerations, that a retrolisthesis of a lower lumbar spine segment is
correlated with a reduction of lumbar lordosis, endplate inclination, and
segmental height.
PMID- 10675943
TI - Treatment of intracapsular fractures of the femoral neck in Denmark: trends in
indications over the past decade.
AB - A questionnaire survey was set up in Denmark in 1996 including 40 orthopedic
departments and 20 departments of general surgery, all dealing with the treatment
of intracapsular fractures of the femoral neck. The aim of the survey was to
investigate whether the treatment of these complex fractures in Denmark followed
the international standard, the "gold standard", recommended in the recent
international literature. A shift in the treatment was noted, as compared with an
earlier questionnaire survey in 1988, with more orthopedic departments performing
a graduated treatment with respect to the age of the patients and fracture grade
(Garden class). That is: a) nondisplaced fractures, b) displaced fractures (b.1
below 75 years and b.2 above 75 years). Cannulated screws/pins were more commonly
used in Garden I and II fractures (non displaced fractures) and in Garden III and
IV fractures (displaced fractures) in patients below 75 years.
Hemiarthroplasty/arthroplasty were more commonly used in the older age group,
above 75 years, in displaced fractures (Garden III-IV). It is concluded that a
shift in the treatment of these fractures has occurred, especially in orthopedic
departments. One reason for this may be an increasing number of orthopedic
specialists with experience in arthroplastic surgery, making it possible to
perform and/or supervise younger surgeons in this procedure. Another reason must
be an increasing awareness among orthopedic specialists in Denmark that
complication rates in osteosynthesis of the displaced fractures (Garden III-IV)
have been too high.
PMID- 10675944
TI - A method to measure acetabular cup anteversion after total hip replacement.
AB - The authors propose a simple and practical method to measure radiologically the
angle of ante- or retroversion of the acetabular cup using a goniometer. It only
necessitates an anteroposterior radiograph centered on the femoral head and
another one centered on the public symphysis. Special x ray equipment, compass,
conversion table, mathematical formulas, or a pocket calculator are not required.
The opening of the prosthetic cup is projected on the film as an ellipse.
According to the rules of descriptive geometry, the true size of the angle of
anteversion is easily obtained. The geometric constructions consist in drawing
four lines. The adequate positioning on a hip radiograph of the protractor, drawn
on the goniometer, permits the direct reading of the true and planar anteversion
angles of the cup.
PMID- 10675945
TI - [Study of the posterior cruciate ligament using a 3D computer model: ligament
biometry during flexion, application to surgical replacement of the ligament].
AB - We have developed a 3D computed model of the knee joint, constructed from MRI
acquisitions in a living individual. We have used this model to perform an
anatomic and biometric study of the posterior cruciate ligament (PCL) during
flexion, and an assessment of the optimal location for an intraarticular graft.
The method used a 3D computed model constructed from MRI acquisitions during knee
flexion (0 to 75 degrees). The range of motion was limited by a positioning
device. We took 13 acquisitions from 0 to 75 degrees of flexion. Each acquisition
consisted of 21 sagittal cross sections of 3 mm slice thickness. We used the
Delaunay reconstruction to obtain a 3D geometric model. A matching process to fix
one part of the articulation during the movement, allows for the kinematic
analysis of the tibia relative to the fixed femur. This model allows to follow
the displacement of a bone point during knee flexion. Knowing the relative
displacement of the bone insertions of the ligament, it may be possible to
determine the length of the PCL and its bands, to evaluate the length variation
during movement, and to determine the optimal location for the insertion of an
intraarticular graft, that would lead to the least stretch during flexion. It was
found that the mean length of the PCL was 30.2 mm, with the posterior band being
30% longer than the anterior band. During flexion the posterior band increases
its length by 10% at 50 degrees flexion, and by 20% at 75 degrees flexion. The
anterior band stretches more, to reach 40% elongation at 75 degrees flexion. The
best position for insertion of a graft seems to be in the posterolateral portion
of the anatomic tibial insertion, and posterior to the anatomic femoral
insertion. This method confirms the data in the literature, states precisely the
length of the different bands of the PCL, and specifies the points of insertion
for a graft, which lead to the least variation in length during flexion.
PMID- 10675947
TI - Radial tunnel release and tennis elbow: disappointing results?
AB - In a retrospective study, 19 patients with 20 decompressions of the posterior
interosseous nerve for radial tunnel syndrome were reviewed. The results were
evaluated using Roles and Maudsley's criteria; they were found to be consistent
with those previously reported: i.e. 75% favorable outcomes. Despite this finding
only 8 patients (40%) stated they were satisfied. The main reason was residual
pain. Shorter delay between the onset of symptoms and surgical treatment as well
as simultaneous release of the lateral epicondylar muscles was found to influence
positively patient satisfaction. These findings suggest that the scoring system
used in the present study and also in previous studies is inappropriate. They
also cast some doubt on the role of compression of the posterior interosseous
nerve in the pathogenesis of chronic lateral elbow pain.
PMID- 10675946
TI - [Gauthier's subcapital osteotomy in the treatment of metatarsophalangeal luxation
of the 2nd ray. Apropos of 44 cases with 5 year followup].
AB - The authors report on a series of 44 metatarsophalangeal dislocations of the
second ray which were treated surgically using Gauthier's technique. The patients
were 44 middle-aged women. The surgical indication was a dislocation of the 2nd
metatarsophalangeal joint with hallux valgus. There was excess length of the
second metatarsal ray or acquired shortness of the first metatarsal. The
treatment always included an osteotomy of the neck maintained by a transosseous
pin. The average follow-up was 8 years and 3 months (minimum 5 years).
Postoperative results were evaluated using clinical and radiological criteria.
Surgical treatment gave 68.2% very good and good results and 4 recurrences of
dislocation. The results in this series are identical with those in other series
reported, but the backward displacement of the head of second metatarsal was
found to be limited. Weil's osteotomy seems to provide better results because it
better restores the relative lengths of the metatarsals and often makes
interphalangeal arthroplasty unnecessary. Gauthier's metatarsal osteotomy is an
easy procedure which effectively improves static metatarsalgia, but it provides
limited metatarsal shortening. Weil's osteotomy is preferable in cases with long
lateral metatarsals.
PMID- 10675948
TI - [Pneumatocyst of the sacrum. Apropos of a case].
AB - We report a new case of asymptomatic pneumatocyst of the sacrum in a 45-year-old
man with a history of lumbago. Pneumatocysts are rare benign osseous lesions
filled with gas and always found in the subchondral bone of the sacral or iliac
side of the sacroiliac joint. The diagnosis is made by CT scan. In the sacral
location, the pneumatocyst is asymptomatic and surgical treatment is not
justified.
PMID- 10675949
TI - Stress fracture of the acetabular roof. Case report and value of MRI.
AB - The authors report the case of an 11-year-old boy with pain in the left leg
without history of recent trauma. The diagnosis of a stress fracture of the
acetabulum was made based on MRI and bone marrow biopsy. They discuss the role of
MRI in the diagnosis of a stress fracture.
PMID- 10675950
TI - Primary hydatid disease in lumbar muscles.
AB - The authors report a case of primary hydatid disease in the lumbar muscles of a
40-year-old male patient. The rarity of this disease in our regions and the low
incidence of this location make primary diagnosis difficult. The tumor had been
treated elsewhere five years previously by means of simple excision. Recurrence
of the lesion was diagnosed five years after the first surgery. Wide excision of
the cyst and pericyst with a 3.5-cm security margin was performed. Six years
after the last surgery, no recurrence has been detected.
PMID- 10675951
TI - Bilateral intraosseous lipoma of the calcaneus. A case report.
AB - A case of bilateral intraosseous lipomas of the calcaneus is presented. The
bilateral localization of calcaneal intraosseous lipomas is extremely rare.
PMID- 10675952
TI - Treatment of a simple bone cyst of the calcaneus by endoscopic curettage with
cancellous bone injection.
AB - The authors report a case of simple bone cyst involving the calcaneus, treated by
curettage under endoscopy with cancellous bone injection, and its course and
follow-up at two years. This new technique has not yet been published for simple
bone cysts of the calcaneus. Endoscopic curettage of the cavity of a simple bone
cyst can be advocated for the calcaneus to minimize incisions and to avoid
cutaneous complications.
PMID- 10675953
TI - Idiopathic symmetrical shortening of the fourth and fifth metacarpal and
metatarsal bilaterally. A case report.
AB - A case of idiopathic bilateral symmetrical shortening of the fourth and fifth
metacarpal and metatarsal bones in an active 10-year-old Caucasian female is
described. The deformity did not result from trauma or an endocrine disorder and
it was not hereditary. The function of the hands and feet was normal, and the
only discomfort was of a cosmetic nature. Metacarpal or metatarsal lengthening
therefore seemed unnecessary.
PMID- 10675954
TI - [Decision making in borderline situations--anesthesiological aspects].
AB - Over the last few decades, major biomedical developments have been taken place so
that dying and death are nowadays more a matter of deliberate decision--a change
that has profound ethical and legal implications. This progress has influenced
medical decision-making generally and intensively, especially that of the surgeon
and the anaesthesiologist. The representatives of these professions are often
confronted with problems of life-sustaining therapy at the beginning and the end
of life and of resuscitative measures. The surgeon and the anaesthesiologist have
to accept the necessity of close partnership while maintaining a clear dividing
line between their responsibilities, but at the same time jointly doing their
utmost for the good of the patient. Above all the physician has to give due
consideration to the patient's will, but there are many and sometimes great
variations in the individual situations of conscious or permanently unconscious
patients. The highest courts in Germany have laid down that the principles of
medical ethics must supplement the law.
PMID- 10675955
TI - [General anesthesia or spinal anesthesia for hip prosthesis replacement? Studies
of acceptance of both procedures by patients].
AB - Patients undergoing total hip replacement are given general anaesthesia or spinal
anaesthesia. The aim of this study was to investigate the experiences of patients
before, during and after general anaesthesia (68 patients) or spinal anaesthesia
(77 patients). Our investigation revealed that with regard to complications
(nausea and vomiting, headache and back pains), no differences between the two
methods occurred. Between 25 and 30% of the patients in both groups had these
complications, although there were differences between both groups regarding
their concomitant diseases and medication. Patients with spinal anaesthesia had a
three times higher incidence of cardiac concomitant diseases and received
corresponding drugs more frequently. We found that the time of postoperative
analgesia after spinal anaesthesia (210 minutes) was significantly longer than
after general anaesthesia (90 minutes). The majority of the patients in both
groups (approximately 90%) were satisfied with the chosen method of anaesthesia
and with the postoperative pain therapy. These findings make it possible to
conclude that with the exception of differences in the postoperative analgesia
time, there are no differences between general anaesthesia and spinal anaesthesia
regarding complications and satisfaction of the patients with both methods of
anaesthesia.
PMID- 10675956
TI - [Continuous spinal anesthesia in very elderly patients with high anesthesia risk
in traumatologic-orthopedic and general surgery interventions].
AB - Continuous spinal anaesthesia (CSA) was carried out via a 28-gauge spinal
catheter in 154 surgical patients at the Department of Anaesthesiology and
Critical Care at Radeberg Asklepios-ASB Hospital between May 1992 and March 1999.
The method was used preferably in patients aged over 70 (mean age 82.3 years)
with high general risk during anaesthesia (ASA III-IV) who underwent orthopaedic
or general surgery of the lower limb and hypogastrium. Remarkably, an anaesthetic
level of between Th 8 and Th 10 was achieved with the low initial dose of 7.5 mg
of 0.5% hyperbaric bupivacaine. Only minimal cardiovascular and respiratory side
effects were observed in comparison to single shot spinal and general
anaesthesia. In the whole series, no anaesthesia-related complications were seen.
Another benefit of CSA is the option of applying a second dose with longer
duration of surgery to keep the optimal anaesthetic level. In addition, the
method is suitable for postoperative analgesia over a period of 2 to 3 days.
PMID- 10675957
TI - [High-frequency jet ventilation for placing tracheal stents--a case report].
AB - Stenoses of the larynx and trachea may cause acute life-threatening situations.
Surgical procedures in patients presenting this type of problem are a real
challenge for the surgeon and the anaesthesiologist. Depending on the extent and
the nature of the stenosis, the insertion of a stent may be the best therapeutic
option. In this case, the high frequency jet ventilation offers certain
advantages for the surgeon. Thanks to modern jet ventilators with automatic
pressure monitoring and jet ventilation tubes with a separate lumen for pressure
monitoring, the danger of barotrauma is considerably reduced, even in patients
with a high-degree stenosis of the larynx and trachea. During insertion of a
tracheal stent during jet ventilation, the complete cross-section of the trachea
must at least be temporarily available to the surgeon. In addition, at the end of
the operation the newly implanted stent should not be altered by manipulations
necessary for artificial respiration. We describe a new method which uses
tracheal jet ventilation for implanting a stent with only short interruptions of
artificial ventilation. During recovery from anaesthesia, there is no risk of
dislocating the newly placed stent.
PMID- 10675958
TI - [Tuberous breast syndrome. Report on a series of 22 operated patients].
AB - The tuberous breast syndrome is a rare unilateral or bilateral breast
malformation presenting at the age of mammary development. It requires surgical
correction, depending on the severity of the clinical expression, because of its
inaesthetic appearance. We report a series of 22 patients (35 breasts) treated
and followed up in the plastic and reconstructive surgery department of Rennes
over a period of nearly ten years. The average age was 18 +/- 3.2 years (range:
15-26 years old). Long-term results were assessed by the surgical team and the
patients on the basis of objective and subjective criteria with an average follow
up of 36 months (12 to 116 months). In our opinion, surgical correction should be
proposed after puberty with, whenever possible, section of the basal fibrous ring
and glandular plasty via a periareolar incision. The use of mammary implant alone
or in combination with breast tissue remodelling must be reserved for hypoplastic
cases only.
PMID- 10675959
TI - [Adipocyte microinfiltration in the face or tissue restructuration with fat
tissue graft].
AB - The author presents his experience of the autologous fatty tissue
transplantation. He calls his method microinfiltration of adipocytes (MIA). The
fat of the body is harvested with the technique of syringe liposuccion without
trauma and is refined and placed in an intricate layering of autologous fatty
tissue with anatomic patented microcanulaes. This procedure named Lipostructure
by Coleman is not a lipofilling or "liposculpture" as described by P. Fournier in
1989. By focusing on the procedure as autotransplantation fat grafting technique
and fully respecting the delicate nature of the fat cell, the author has been
able to document a high rate of success with 3 years follow-up.
PMID- 10675960
TI - [Deep vertical lift and its development regarding the central facial area and
lower two-thirds of the neck. Our technique].
AB - Deep vertical facelift, that we have developed over the last eight years,
presented certain weak points in the central facial zone and lower two-thirds of
the neck. Ageing of the central facial zone is associated with two main sings:
skeletization of the orbit and accentuation of the nasolabial fold. These two
elements are due to ptosis of the submalar fat. The obvious solution is to
restore the position of this fat. We present a rapid and effective solution. In
the lower two-thirds of the neck, in the presence of marked ptosis, we now opt
for extensive deep vertical facelift with retroauricular dissection. The skin of
the neck in front of the sterno-cleido-mastoid muscle is not dissected, but the
SMAS is extensively dissected over the mandibular angle continuous with the
facial dissection as fat as the lower part of the neck.
PMID- 10675961
TI - [Skin and muscle flaps to cover and fill chronic open osteitis of the tibia.
Results with 10 cases].
AB - Chronic osteomyelitis is a severe long-term bone infection which retains its
mechanical qualities. The authors report 10 cases of osteomyelitis of the tibia
treated by muscular and fascio-cutaneous flaps and reviewed at one year follow
up. Four cases concerned the third upper part of the tibia, 3 the middle and 3
the lower third. Two total failures at the third lower part and three
complications which finally healed with delay were observed. The results of this
small series compared with the reports in the literature suggest the value of
large excision with coverage by a well vascularized flap and the need for
antibiotics. The choice of flap is related to type and site of the bone defect.
Another question should be raised concerning the surgical strategy in one--or two
-stage management and the duration of antibiotic therapy.
PMID- 10675962
TI - [Position of venous outflow: a crucial aspect in flaps with 2 opposed pedicles.
Application to the cutaneous delay phenomenon. Experimental study with rats].
AB - In the present study, the authors decided to focus on the effect of the venous
outflow location in the survival of a flap with a choke vessels barrier by means
of a rat bipedicled ventral island flap. In a first experiment, the extent of
flap necrosis was examined in three experimental groups: group 1, alternate vein
and artery ligation (n = 5); group 2, unilateral artery ligation (n = 5); group
3, unilateral pedicle ligation (n = 5). Less than 10% necrosis occurred in group
1; 28% in group 2 and 33% in group 3. In a second experiment we applied the first
results to the delay phenomenon. 10 rats were divided into 2 groups: group 4,
primary ligation of a complete pedicle on one side; group 5, primary alternate
vein and artery ligation and the flaps were raised 21 days later. We observed 20%
necrosis in group 4 and only 4% in group 5. The data of the first experiment
indicate that a vein remaining near the artery can be a dramatic obstacle to the
efficiency of choke vessels. The second experimental study shows the superiority
of primary selective ligation in the delay phenomenon.
PMID- 10675963
TI - [Facial aging. Analysis of esthetic semiology and proposal for systematic
treatments].
AB - Surgical literature is severely lacking in anatomo-clinical descriptions of
facial aging. Only a few authors provide minor reports on the pathophysiology of
aging in order to propose methods of correction. It therefore appears important
to start with a diagnosis of the lesions as precise as possible in order to be
able to perform the most appropriate treatment. We propose a semeiological
analysis of the face, not only stage by stage but layer by layer, starting with
the skin, then the fat, muscle and bone. We will then consider the methods which
appear to be the most suitable for correction of the various structures concerned
by aging within the framework of a total facial reorganisation. We will conclude
with a presentation of surgical cases describing the surgical techniques used,
with respect to a semiological analysis from each case.
PMID- 10675964
TI - [Unusual breast scars].
AB - The authors report the case of an unusual form of skin tattoo, discovered on the
breasts of a young woman, corresponding to several scars forming a symbolic
image, performed deliberately with a burning object. This form of mutilation is
called "branding". Imported from England, it is developing in France as a result
of fashion, but its followers could one day regret the permanent scars left by
this deep burn.
PMID- 10675965
TI - [Who are the French plastic surgeons?].
AB - Based on data from the national advice of the Conseil National de l'Ordre des
Medecins (French Medical Board), the author found 654 plastic surgeons in France
and classified them into five categories, demonstrating the increasing proportion
of females in this specialty.
PMID- 10675966
TI - [New frontiers in aesthetic surgery. Dallas, May 14-19, 1999].
PMID- 10675967
TI - Perceived, actual, and seasonal changes in the shape of the face, hands and legs.
AB - In this study, we measured the shape of the face, legs, hands and fingers during
the course of a day to determine the amount of swelling. We examined the
relationship between the perception of swelling and the degree of actual
swelling, and considered the influence of seasonal factors. The topology of the
face was measured using the 3D curved shape measuring apparatus, VOXELAN, while
the circumference of the legs and fingers and the volume of the hands were also
recorded. The measurements were used to determine the amount of change in each
parameter, which was then used to determine the degree of swelling. The subjects
for the experiment were 10 healthy Japanese women aged 24 to 30 years of standard
build (BMI: 19.3-25.0). Measurements were carried out twice a day in the mornings
and afternoon, first between 8:30 and 10:00 a.m. and then between 4:00 and 5:30
p.m. At each measurement session, subjects were asked if they perceived swelling
to have occurred. We investigated the relationship between the degree of actual
swelling and the reported perception of swelling. We also investigated the
influence of seasonal factors by conducting the same tests on the same subjects
in summer (August 1997) and in winter (February-March 1998). The relationship
between perceived and actual swelling differs depending on the part of the body.
For the face, actual swelling correlates strongly with perceived swelling. This
trend is particularly noticeable for the upper eyelids. For the thigh and lower
leg, on the other hand, there was no significant difference. The frequency with
which subjects reported the perception of swelling varied depending on the area
of the body, and was generally extremely low for the thighs, hands and fingers.
With respect to seasonal variation, swelling in the face, hands and feet tended
to be more pronounced during the summer. In the facial region, the biggest
difference was in the lower eyelid, where swelling increased more than five
times. This level of variation suggests that the atmospheric temperature is the
main factor affecting swelling.
PMID- 10675968
TI - Blood pressure and hormonal responses to short whole body cold exposure in
subjects with high dietary salt intake.
AB - The objective of the present study was to test a hypothesis that a high dietary
salt intake potentiates a cold induced increase in blood pressure in normotensive
men. Male subjects (n = 12) were given 7 g day-1 sodium chloride during the cold
months of the year, divided in 3-4 doses per day and dissolved in water, for 14
days additional to their normal diet which contained on the average 9.7 g sodium
chloride per day. The same subjects, having their normal diet, served as
controls. The resting blood pressure was measured on the fourteenth day seven
times at the intervals of five minutes in a climatic chamber in thermoneutral
conditions. Then the subjects, wearing a three-layer winter clothing, moved into
a wind tunnel (-15 degrees C, air velocity 3.5 ms-1) in which they stayed for
fifteen minutes and the blood pressure was recorded at the intervals of three
minutes. After the cold exposure, the subjects moved back into the climatic
chamber for 30 min and the blood pressure was measured as before the cold
exposure. Blood samples were drawn before and after the experiment for ion and
hormone measurements. A 12 h urine sample was collected just prior to the cold
exposure. A significant difference both in systolic (7 mmHg) and in diastolic (7
mmHg) blood pressure was found between a salt load group and control group under
thermoneutral conditions, repeatedly measured over 30 min (paired Student's t
test; p < 0.05). During the whole body cold exposure, blood pressure
significantly increased both with and without the extra salt load (repeated
measures ANOVA, Student-Newman-Keuls; p < 0.05). The level to which the mean
arterial pressure increased during the exposure was independent of the salt
intake and the profile of the mean arterial pressure curve was similar in both
groups. The systolic pressure increased by a 25 mmHg in both groups during the
cold exposure. The increase in the diastolic pressure was significantly (paired
Student's t-test, p < 0.05) higher in the high salt group (18 +/- 4 mmHg) than in
the control group (12 +/- 3 mmHg) thus supporting partly our hypothesis. After
the two-week high salt intake, serum Na+, K+, Cl-, Hct, and plasma Hb were at the
similar level as before the extra salt intake. Plasma renin activity, NT-proANP,
ANP, and serum aldosterone were not different between the groups, both before and
after the cold exposure. The main findings are: 1) the mean arterial pressure
increases to the same level and in the same manner independent of the salt load
during a short whole body cold exposure and 2) in cold the diastolic blood
pressure increases significantly more in people under a very high salt diet.
PMID- 10675969
TI - Changes in physical characteristics and performance of elite sailors following
introduction of a sport science programme prior to the 1996 olympic games.
AB - The objective of this study was to examine changes in sailors' physical
characteristics during three different time periods immediately before the 1996
New Zealand Olympic trials, as a result of a newly introduced sport science
programme. Twenty five (19 male and 6 female) Olympic development squad members
volunteered as subjects and completed fitness tests at different times between
April 1995 and March 1996 after being administered with individualised physical
training programmes. Statistically significant improvements were observed in body
weight, sum of skinfolds, flexibility (assessed using a sit-reach test), aerobic
endurance (assessed using a maximal effort 2500 m rowing test) and strength
(assessed as the maximum number of push-ups, pull-ups, and sit-ups that could be
completed in 2 minutes) over the three time periods. Thus, physical training was
effective in improving many aspects of sailors' fitness, especially early in the
sailing season as a result of pre-season training. Physical performance
correlated poorly with both light and heavy wind racing performance. The results
suggest that individually tailored training programmes will increase sailing
specific fitness. However, it is impossible to know what proportions of racing
performance can be attributed to physical fitness, skill, talent, and technology,
therefore the effect of physical training on racing performance is difficult to
determine.
PMID- 10675970
TI - Analysis of heart rate variability during mental task with reference to ambient
temperature.
AB - The purpose of this study was to evaluate the cardiac autonomic control over
mental task under various ambient temperatures (21 degrees C, 28 degrees C and 35
degrees C). Seven healthy male subjects engaged in the mental tasks, which
consisted of distinctive reaction-time tasks. Respiratory coefficient of
variation of instantaneous heart rate (CVRESP), derived from the cross
correlation function between heart rate and respiratory curve, was used as a
parameter to assess parasympathetic nervous functions. The difference between
total coefficient of variation (CVIHR) and CVRESP was used as a parameter to
assess sympathetic nervous functions. The mean heart rate increased at high
ambient temperature (35 degrees C) and also during mental task. Both the effects
of ambient temperature and task conditions were significant on heart rate, and
also on CVIHR. Moreover, the effects of ambient temperature and task conditions
in CVIHR were divided into the effect of ambient temperature on CVRESP and the
effect of task conditions on the difference between CVIHR and CVRESP. These
results implied that respiratory modulated parasympathetic activity might control
basal the effect of ambient temperature, and the other components including
sympathetic activity contribute to the increase in heart rate due to mental task.
PMID- 10675971
TI - Effects of mental task on heart rate variability during graded head-up tilt.
AB - In this study, we used spectral analysis of heart rate variability (HRV) to
estimate the changes in autonomic control in response to disparate stimuli
produced by mental task and graded head-up tilting. The low frequency (LF)
component of HRV provided a quantitative index of the sympathetic and
parasympathetic (vagal) activities controlling the heart rate (HR), while the
high frequency (HF) component of HRV provided an index of the vagal tone. We
studied 17 healthy male subjects (21-25 yr of age) who were placed on a tilt
table and the graded tilt-protocol involved tilted sine angles 0.0, 0.2, 0.4,
0.6, 0.8, and 1.0. These tilt-protocols were repeated with or without the mental
task, which consisted of auditory distinctive reaction-time tasks. The basal
autonomic mode against the graded head-up tilt was characterized by reciprocal
changes in sympathetic and vagal tones. There were significant increases of HR
corresponding to the mental task with lower tilt-angle, albeit the changes with
higher tilt angles were not significant. Furthermore, there were increases and
decreases of the LF component induced by the mental task at lower and higher tilt
angles, respectively. These results revealed that the different responses of HR
and LF component against the same tasks could be derived from the alterations of
autonomic mode during gradual changes in autonomic control.
PMID- 10675972
TI - Cardiovascular regulation during water immersion.
AB - Head-out water immersion at thermoneutral temperature (34-35 degrees C) increases
cardiac output for a given O2 consumption, leading to a relative hyperperfusion
of peripheral tissues. To determine if subjects immersed in water at a colder
temperature show similar responses and to explore the significance of the
hyperperfusion, cardiovascular functions were investigated (impedance
cardiography) on 10 men at rest and while performing exercise on a leg cycle
ergometer (delta M = approximately 95 W.m-2) in air and in water at 34.5 degrees
C and 30 degrees C, respectively. In subjects resting in water, the cardiac
output increased by approximately 50% compared to that in air, mainly due to a
rise in stroke volume. The stroke volume change tended to be greater in 30
degrees C water than in 34.5 degrees C water, and this was due to a greater
increase in cardiac preload, as indicated by a significantly greater left
ventricular end-diastolic volume. Arterial systolic pressure rose slightly during
water immersion. Arterial diastolic pressure remained unchanged in 34.5 degrees C
water, but it rose in 30 degrees C water. The total peripheral resistance fell
37% in 34.5 degrees C water and 32% in 30 degrees C water. Both in air and in
water, mild exercise increased the cardiac output, and this was mainly due to an
increase in heart rate. Since, however, the stroke volume increased with water
immersion, cardiac output at a given work load appeared to be significantly
higher in water than in air. The arterial pressures did not decrease with water
immersion, despite a marked reduction in total peripheral resistance. These
results suggest that 1) during cold water immersion, peripheral vasoconstriction
provides an additional increase in cardiac preload, leading to a further increase
in the stroke volume compared to that of the thermoneutral water immersion, 2)
the mechanism of cardiovascular adjustment during dynamic exercise is not changed
by the persistent increase in cardiac preload in water immersion, and 3) a
relatively high cardiac output during water immersion is to maintain a proper
arterial pressure in the face of reduced vascular resistance.
PMID- 10675973
TI - Protecting workers with developmental disabilities.
PMID- 10675974
TI - Useful bookmarks for your virtual library.
PMID- 10675975
TI - Control of exposure to perchloroethylene in commercial dry cleaning
(ventilation). National Institute for Occupational Safety and Health.
PMID- 10675976
TI - Identification of potential hazards associated with new residential construction.
AB - There were several advantages and limitations of this observational study. The
most important advantage of this study was the opportunity to observe residential
construction workers performing their jobs. By observing work practices, valuable
information was gathered about specific trades and their potential exposure to
various chemical and physical agents. This information will be useful in guiding
subsequent exposure assessments. Probably the greatest limitation of this study
was the lack of participation by homebuilders. Ideally, observations of
construction processes would have been more objective if the study included the
participation of more than one homebuilder. Aside from one worker who was
observed to wear safety glasses, leather gloves, and a dust mask, virtually no
personal protective equipment (PPE) was observed onsite. Often small contractors
do not have the financial resources necessary to procure the appropriate PPE and
issue these items to the workers. Based on hazard prevalence, professional
judgement, and the degree of hazardous product use, potential exposures that
warrant quantitative sampling efforts during Phase 2 of this study are:
bulldozer/backhoe operators--noise, vibration, diesel exhaust; concrete workers-
naphtha, mineral spirits, Portland cement; asphalt workers--petroleum
hydrocarbons, asphalt, mineral spirits; plumbers--methylethyl ketone, acetone,
tetrahydrofuran, cyclohexanone; drywall finishers--total and respirable dust,
hexane, acetone; painters--ethylene glycol, VOCs; masons--dust (during the
preparation of mortar); floor preparation technicians--total and respirable dust;
and ceramic tile installers--toluene, naphtha, silica (from grout powder).
PMID- 10675977
TI - Self-assessment of exposure--a pilot study of assessment of exposure to benzene
in tank truck drivers.
AB - Occupational hygienists or safety engineers perform exposure assessments, mostly
with very little participation by the workers. The objective of our study is to
involve the workers themselves in the assessment and measurement procedure, the
self-assessment method (SAE). A pilot study has been carried out involving tank
truck drivers at a company transporting gasoline. The drivers were supposed to
decide themselves when, and how often, they wanted to measure benzene exposure by
using diffusive samplers that were then sent by mail for analysis. After every
measurement they received their own results in a personal document for
interpretation. The company management also received a document, which summarized
all the drivers' measurements. Expert measurements, with the same type of
sampler, were also accomplished to evaluate the self-assessments. The geometric
mean and the 95 percent confidence intervals of the measurements made by the
drivers (29 measurements) was 0.17 (0.11-0.26), and by an occupational hygienist
(8 measurements) 0.12 mg/m3 (0.04-0.37). The results show that the drivers
technically can perform SAE. Interviews with the workers and the management
indicated that some kind of organizational support within the company is needed
to implement the method into the regular internal control of the working
environment.
PMID- 10675978
TI - Chemical hazards in radiology.
AB - A variety of chemicals are used in medical imaging as developer and fixer
ingredients, germicides, and cleaning agents. Glutaraldehyde, a potent
sensitizer, may cause occupational skin and respiratory diseases in exposed
individuals. Poor ventilation, unsafe practices, and lack of hazard recognition
may contribute to occupational asthma and other respiratory disease in
susceptible medical imaging personnel. Failure to respond effectively to initial
health complaints and reduce exposure levels can have serious consequences for
affected employees. It is therefore important for occupational safety and health
professionals to alert health facility managers to potential dangers and to
recommend effective intervention strategies. When problems are identified, a
multidisciplinary team approach is the best method for evaluating and controlling
hazards. This team should include industrial hygienists, safety staff,
occupational medicine physicians, mechanical and ventilation engineers, personnel
specialists, and medical imaging staff. A thorough hazard assessment, medical
diagnosis, and administrative personnel actions are critical to effective problem
identification and correction. In the case of chemical sensitization, removal of
the affected employee may be necessary. By working with designers and equipment
installers to monitor compliance with appropriate codes and manufacturers'
specifications, hazards can be prevented. We present additional operations,
ventilation, and design improvements to reduce chemical exposures to radiology
employees.
PMID- 10675979
TI - Containment testing of laboratory hoods in the as-used condition.
AB - Airborne contaminants generated inside laboratory fume hoods during use leak into
the breathing zone of the user. Concentration of the leakage is unknown and
variable depending on laboratory design, work practices, arrangement of internal
apparatus, face velocity, and sash height. Surrogate tracer gas tests have been
developed using sulfur hexafluoride (SF6) and a manikin to estimate leakage. This
study presents results of hood leakage tests using SF6 with a manikin and then a
live operator performing a phenol:chloroform (P:C) extraction. Four hoods were
tested in each of three institutions during normal work hours with the lab
occupied. The purpose of the study was to determine leakage concentrations for
the SF6-manikin with effects of sash height, hood contents as found and after
being cleaned out, face velocity, and the actual P:C and SF6 exposure
concentrations of the user during work. Results indicate P:C was not detectable
in the breathing zone of the 12 operators (< 0.1 ppm) at their selected operating
sash heights (7 to 15 inches). Simultaneous SF6 concentrations were also minimal
(average 0.06 ppm). Average leakage was 0.02 percent for SF6 and less than 2
percent based on chloroform concentrations measured in the breathing zone of the
operator and inside the hood. SF6 percent leakage was greater when sash height
was above the breathing zone of the manikin (average 2.09 percent) and lower
leakage (average 0.02 percent) when below the breathing zone (26 inches or less).
Average face velocity did not appear to be a predictor of average hood leakage.
Cleaning out the hoods did not reduce leakage in most tests. The data from this
study shows that when providing training on proper work practices for lab hood
use, lowering the sash should be stressed as being the major factor in reducing
hood leakage.
PMID- 10675980
TI - Lead abatement training for underserved populations: lessons learned.
AB - An environmental-justice (equity) grant program was used to make accessible an
existing lead-training program to minority persons and residents of low-income
communities. The purpose of the program was to enhance the knowledge base within
the communities concerning lead hazards and intervention strategies and expand
possibilities for employment in the lead abatement industry. Barriers to
attendance were anticipated and addressed, and included transportation, meals,
license application fees, reminders of course date and location, and day care.
The program was evaluated through measures of recruitment rates, pre- and post
testing scores, and change in perception of confidence at pre-test, post-test,
and at four-month follow-up. Fee-paying registrants over the same time period
were used as a comparison group. First day attendance rates for individuals
recruited into the equity-grant was 59 percent, of these 94 percent completed all
days. Equity and fee-paying groups had similar scores on the pre-test (p = .209),
while mean scores on the final exam differed significantly (p < .001) between the
groups and were 77 percent and 85 percent, respectively. After adjusting for
demographic and course type attended, perceptions of self-efficacy (benefit) and
outcome-effectiveness (confidence) increased significantly from pre- to post
tests for both groups and remained at post-course levels at four months follow
up. Lessons learned include: (1) Lead abatement and other related activities can
be successfully taught through traditional training methods; (2) A necessary
element for delivery of educational services to minority groups is forming
workable ties with local community groups, but eligibility requirements must be
maintained; (3) Once barriers to first-day attendance are overcome, the
information necessary to perform specific work skills can be taught; (4) Positive
changes in belief are not dependent on minority status, income, or education
levels; (5) Training and education increased confidence in ability to perform
learned skills, and belief that there will be a beneficial outcome when performed
for themselves, their families, and communities; and, (6) A consensus regarding
applicability of regulations must be achieved among federal, state, and local
communities.
PMID- 10675981
TI - Optimization of a solid sorbent dynamic personal air sampling method for
aldehydes.
AB - A solid sorbent personal dynamic air sampling method for aldehydes using
chemisorption with 20 percent (w/w) O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine
hydrochloride (PFBHA) on Tenax TA has been optimized for several aldehydes. The
method for formaldehyde was developed after optimization for valeraldehyde and
acrolein. The effects of temperature, intermittent exposure, and flow rate on
sampling efficiency were investigated. Vapors of known concentrations were
generated in Tedlar gas bags by syringe injection. Aldehyde chemisorption by
reaction with 200-mg coated solid sorbent in a Pyrex Tube (7-cm length, 7-mm OD,
and 5-mm ID) occurred during dynamic collection with a personal sampling pump
operated at 10, 50, or 100 mL/min. The oxime derivatives were 81-87 percent
desorbed by shaking with hexane for two minutes or more, resulting in
coefficients of variation ranging between 4-7 percent. Aliquots were then
injected for gas chromatographic analysis on a nonpolar capillary column with
mass spectrometric or 63Ni electron capture detection. Formaldehyde at 8 ppm
hours equivalent to the permissible exposure limit (PEL) concentration was
sampled with a recovery of 94 +/- 4 percent at 50.0 +/- 0.5 mL/min. Valeraldehyde
and acrolein at their PELs showed no significant differences (P < 0.05) in
recoveries at different relative humidities (1 and 90%), temperatures (1, 25, and
40 degrees C), or intermittent sampling protocol. The sampler capacity at 75
percent recovery was at a PFBHA:aldehyde molar ratio of 12:1 at 10.0 +/- 0.1
mL/min, 17:1 at 50.0 +/- 0.5 mL/min, and 26:1 at 100 +/- 1 mL/min.
PMID- 10675982
TI - An effective protection factor study of respirators used by primary lead smelter
workers.
AB - An industrial hygiene study was conducted at a primary lead smelter to determine
the effective protection factors for negative pressure and powered air purifying
half-mask respirators. The study involved 99 paired personal samples taken in six
different work areas, in which randomly chosen subjects from the workforce wore
dual sampling pumps connected to closed-face 37-mm cassettes. The cassettes were
attached either to the workers' lapels for exposure measurements outside the
respirator or to a ported respirator for exposure measurements inside the
respirator. Samples were collected throughout the work shift and analyzed for
lead according to National Institute of Occupational Safety and Health (NIOSH)
Method 7082. Using particle size distribution data obtained for the same
workplaces, the within-mask samples were corrected for sampling bias. The
negative pressure half-mask respirators showed a mean effective protection factor
of 6.5 and a mean corrected effective protection factor of 4.56, with a 5th
percentile less than 0.5. Approximately 80 percent and 90 percent of the
effective protection factors and the corrected effective protection factors,
respectively, were equal to or less than the assigned protection factor of 10.
For the powered air purifying half-mask respirators, the means for effective
protection factor and corrected effective protection factor were 18.20 and 11.92,
respectively, with a 5th percentile of 1.0 or less. Approximately 90 percent and
95 percent of the effective protection factors and the corrected effective
protection factors, respectively, were equal to or less than the assigned
protection factor of 50. The uncorrected and corrected within-mask lead
concentrations for both types of respirators exceeded the Occupational Safety and
Health Administration (OSHA) permissible exposure limit (PEL) for lead by 19
percent to 58 percent. These results indicate that the straight application of
assigned protection factors to actual workplace situations may not always be
appropriate.
PMID- 10675983
TI - Synthesis and cytotoxicity of 2,4-disubstituted and 2,3,4-trisubstituted
brominated pyrroles in murine and human cultured tumor cells.
AB - The 2,4-disubstituted and 2,3,4-trisubstituted brominated pyrroles were
successfully prepared and demonstrated potent cytotoxicity against the growth of
suspended murine and human tumors, i.e. leukemia and lymphomas, acute monocytic
leukemia, and HeLa-S3 uterine carcinoma. The brominated compounds were more
selective in inhibiting the growth of tumors derived from human solid tumors.
Nevertheless, activity with some of the derivatives occurred in the human KB
nasopharynx, SW-480 colon, and HCT ileum adenocarcinoma, and lung A549 carcinoma
screens. In Tmolt4 T cell leukemia cells DNA synthesis was reduced over 60 min
from 25 to 100 microM followed by RNA synthesis reduction. De novo purine
synthesis was retarded with the regulatory enzyme PRPP-amido transferase being
markedly inhibited with less effects on the activities of IMP dehydrogenase,
dihydrofolate reductase,, and the nucleoside kinases. After 60 min incubations
d[TTP] and d[GTP] pools were marginally reduced. In vitro ct-DNA studies suggest
that the agents may affect the DNA molecule itself with increased DNA viscosity
and the Tmolt4 studies suggest that DNA cross-linking of DNA strands may be
present.
PMID- 10675984
TI - Structure-activity relationships of polycyclic aromatic amines with calcium
channel blocking activity.
AB - 8-Benzylamino-8, 11-oxapentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane (1)
inhibits the calcium current in L-type calcium channels. A series of
nitrobenzylamines (2, 3, 4), methoxybenzylamines (5, 6, 7), methylpyridines (8,
9, 10), and a phenylhydrazine derivative (11) of 8,11
oxapentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane was synthesized. By
substituting the 8,11-oxapentacyclo-[5.4.0.0(2,6).0(3,10).0(5,9)]undecane
skeleton with 3-hydroxyhexacyclo-[6.5.0.0(3,7).0(4,12).0(5,10).0(9,13)]tridec ane
(12), 8,13-dioxapentacyclo[6.5.0.0(2,6).0(5,10).0(3,11)]tridecane- 9-one (13),
and pentacyclo-[5.4.0.0(2,6).0(3,10).0(5,9)]undecane (14), the effect of the
polycyclic skeleton could also be investigated. Increased inhibition of calcium
current was observed with aromatic substitution (especially ortho and meta
substitution) in the pentacycloundecane series. The calcium channel activities of
the methoxy compounds were slightly higher than those of the corresponding nitro
compounds while a definite decrease in activity was observed for the
phenylhydrazine and aminomethylpyridine derivatives. Increased inhibition of the
calcium current was also observed for structures in which the polycyclic 'cages'
were enlarged. Structure-activity relationships in this series of compounds
therefore appear to be dominated by geometric or steric constraints.
PMID- 10675986
TI - New NO donors with antithrombotic and vasodilating activities, Part 28. N-(1
cyanoalkyl)-N-hydroxyureas.
AB - Nineteen N-(1-cyanoalkyl)-N-hydroxyureas comprising aliphatic (3a-i, 4a, b, and
5a) and aromatic (3j-n, 4c, 5b) compounds were prepared, fourteen of them for the
first time, and tested for antithrombotic (p.o. administration to rats, 60 mg/kg)
effects. The N-(1-cyanocyclohexyl)-N-hydroxy-N'-phenylurea (3j) was most potent
and inhibited laser-induced (35 mW, 50 ms) thrombus formation in arterioles by
21% and that in venules by 15%. The compounds form nitric oxide in vitro by the
addition of a Fe3(+)-porphyrin complex and an oxygen donor. Moreover, the most
active compound 3j in vivo exhibits the highest NO formation in vitro.
Furthermore, it was shown that the cyano group is essential for the desired
activities and NO formation. These results suggest that the title compounds act
as NO donors.
PMID- 10675985
TI - Anti-inflammatory and analgesic amides: new developments.
AB - A series of substituted N-cycloalkyl benzamides, cinnamamides, and indole-3
carboxamides were synthesized and evaluated for their analgesic, antiinflammatory
activities as well as for their gastrointestinal irritation liability.
Indomethacin was used as reference drug in both tests. Compounds 1k, 1b, 1h, 1j,
and 1g were the most active in the antiinflammatory paw edema inhibition test,
with a sharply dose-dependent effect. In terms of the analgesic activity (acetic
acid writhing test), the most active compound was 5a followed by 3a, but many
other compounds were found to have a non-negligible potency. Even in this case,
the effect was dose dependent.
PMID- 10675987
TI - First bioanalytical evaluation of nonpeptidic cage dimeric HIV-1 protease
inhibitor N-benzyl 4-aryl-1,4-dihydropyridine H17: biotransformation and toxicity
on Hep G2 cells.
AB - Cage dimeric N-benzyl 4-aryl-1,4-dihydropyridine H17 is a moderate inhibitor of
HIV-1 protease. As representative of an innovative and promising class of
nonpeptidic HIV-1 protease inhibitors H17 was selected for the characterization
of the biochemical profile of the cage dimers concerning metabolic and toxic
aspects. In the first bioanalytical evaluation of H17 on Hep G2 monolayers no
phase-I metabolites were found and the extent of conjugation on phase-II of
biotransformation was poor due to steric hindrance of the hydroxymethylene
groups. H17 was found to be nearly non-toxic. A slight noticeable influence on
cell proliferation, however, did not result from apoptotic activities. Thus,
first biochemical evaluation of H17 practically suggests no decrease of an in
vivo bioavailability by metabolization.
PMID- 10675988
TI - [Effect of knee joint flexion and femur rotation on retropatellar contact of the
human knee joint].
AB - The aim of the present study was to evaluate retropatellar contact
characteristics at different angles of flexion of the knee joint. To this end, 6
cadaveric legs were examined using pressure sensitive film (Fuji Prescale type
"super low") at angles of flexion of 45 degrees, 60 degrees, 90 degrees and 120
degrees both in neutral rotation and 10 degrees internal and external rotation of
the femur in the same knee joints. A force of 140 N was applied to both the
vastus medialis and lateralis, and a comparison made with a medially and a
laterally dominating muscle force. The contact areas decreased with increasing
angles of flexion. The medially dominating muscle traction increased the contact
area. Comparison between internal and external rotation revealed a decrease in
contact area on internal rotation. The pressure measurements were comparable in
all loading situations. Comparison between neutral and medial traction revealed
significant differences in contact area, pressure and force. The influence of
femoral rotation showed no significant difference. A comparison of the different
angles of flexion revealed only few significant differences. To prevent the
development of retropatellar arthrosis, maximum contact areas are necessary. The
study has shown an advantage for medially dominating muscle traction, and
external rotation of the femur.
PMID- 10675989
TI - [Measures for biomechanically correct positioning of knee joint endoprostheses].
AB - Normal post-operative function, permanent stable fixation and long life for the
implant material are determined mainly by the correct biomechanical positioning
of the knee joint prosthesis. We have identified six measures within the surgical
procedure that are of vital importance for achieving biomechanically correct
positioning. Because of their great importance, we call these measures "The
Golden Six", and describe their application using the ESKA Resurfacing Knee
System (RKS). This system, which is so designed that it enables a maximal bone
saving resection technique, makes use of a diagonal screw-fixation of the
endoprosthetic elements, resulting in increased primary stability. For the safe
and reliable implementation of our measures, we have developed a special set of
instruments. Anatomical, kinematic and surgical studies have shown that with the
aid of the above-mentioned six measures biomechanically correct positioning of
all the implanted elements can be achieved, thus ensuring trouble-free post
operative function of the knee joint and the least possible mechanical stressing
of the implanted materials.
PMID- 10675990
TI - [Ceramic acetabular cups for hip endoprostheses. 7: How do position of the center
of rotation and the CCD angle of the shaft modify range of motion and
impingement?].
AB - The range of motion (ROM) of total hip prostheses is influenced by a number of
parameters. An insufficient ROM may cause impingement, which may result in
subluxation, dislocation or material failure of the prostheses. In a three
dimensional CAD simulation, the position of the centre of rotation and the CCD
angle of the stem were investigated. Displacement of the centre of rotation of
the femoral head may be due to wear (PE cups) or to the design of the prosthesis
(ceramic cups). Stems of widely differing design have been developed and
implanted. The results of the present study demonstrate that the ROM is clearly
reduced by increasing penetration of the femoral head. At an inclination angle of
45 degrees, a depth of penetration of 2 mm restricts flexion by about 15 degrees,
and a depth of penetration of 3 mm by about 30 degrees. At smaller angles of
inclination the ROM is reduced and flexion and abduction are associated with an
increased risk of impingement. With steeper acetabular cup inclinations, the risk
of impingement decreases, but dislocation, the risk of rim fractures (ceramic
cups), and wear and penetration rates (PE cups) increase. The CCD angle of the
stem should be oriented to the anatomical situation. At high CCD angles (> 135
degrees), flexion is clearly limited, in particular when there is penetration of
the femoral head. For modern total hip arthroplasty, prosthetic systems
characterised by precise positioning of components, minimum wear, slightly
recessed inserts, and appropriate CCD angles should be used.
PMID- 10675991
TI - [Primary stability of press-fit acetabulum cups using a new acetabulum reamer].
AB - The aim of the present study was to assess the initial stability of uncemented
press-fit acetabular components using a newly developed reamer designed to
optimize the surgical preparation of the acetabulum. Ten synthetic human pelves
were used to investigate the stability of 20 uncemented press-fit acetabular
components, each of which was tested in a servohydraulic testing machine for 6
cycles under an axial load of 2.4 kN. The results of the micrometric measurements
revealed satisfactory stability for a reaming depth of 2 mm, and a press-fit of 2
mm. Micromotion was less than 200 microns in all the anatomical sections of the
acetabulum (ischium 63 microns, pubis 150 microns, ilium 85 microns). A press-fit
of 4 mm and the smaller reaming depth of 1 mm were associated with a substantial
decrease in mechanical stability.
PMID- 10675992
TI - [Primary stability of cement-free press-fit acetabulum cups. In vitro
displacement studies].
AB - The initial stability of 6 different hemispherical press-fit titanium acetabular
cups was investigated by lever-out tests using a foam model. Each cup was
implanted in a standardised manner into machined PVC-foam blocks with an
underreaming of 1/2/3 mm, and levered out 5 times. A computer recorded the load
displacement curves. Both insertion forces and lever-out forces increased with
increasing press-fit from 1 to 2 mm. With underreaming of 2 mm, insertion forces
varied between 9 and 34 Nm, and lever-out torques between 13 and 23 Nm. The cup
made up of multi-layer irregular titanium wire mesh had the highest initial
stability of all the cups tested. 3 mm underreaming was associated with insertion
difficulties, so that lever-out is difficult to compare with that with 1 and 2
mm. The amount of contact on the equatorial rim, where we saw the most attrition
after lever-out, is the most important factor for determining the lever-out
torque. The quality of the PVC foam blocks, the accuracy of reaming, and the
definition of cup insertion are very important parameters for test reproduction.
Since the trials were conducted under laboratory conditions, translation of the
results to the intraoperative situation should be undertaken only with certain
reservations.
PMID- 10675993
TI - Management of rape survivors.
PMID- 10675994
TI - Heat stroke in young adults.
PMID- 10675995
TI - Prevalence of Helicobacter pylori infection in patients with functional
dyspepsia.
AB - OBJECTIVE: To investigate the prevalence of Helicobacter pylori infection in
patients with functional dyspepsia. DESIGN: Prospective descriptive study.
SETTING: Surgical unit, Base Hospital, Panadura. PATIENTS: 67 patients with
persistent symptoms suggestive of functional dyspepsia but no clinical,
endoscopic or ultrasonographic evidence of peptic, biliary, pancreatic or
malignant disease. METHODS: Upper gastrointestinal endoscopy and two antral
mucosal biopsies were performed in all patients and the rapid urease test (CLO
test) was done to detect H pylori status. All patients gave informed consent.
RESULTS: Of the 67 patients (32 males) with a mean age of 45 years (35 to 70
years), only 2 patients (2.9%) were found to be positive for H pylori infection.
CONCLUSION: Incidence of H pylori infection was found to be very low in patients
with functional dyspepsia.
PMID- 10675996
TI - Hepatitis B and C virus markers among new entrant medical students.
AB - AIM: To investigate the presence of hepatitis B and C virus markers in new
entrant medical students at the Faculty of Medicine, University of Kelaniya.
METHOD: 456 students (mean age 24 years, SD 3.5, 257 men) were investigated
before they were exposed to clinical work, using a questionnaire to assess
sociodemographic factors and possible risk factors for contracting hepatitis B or
C. Blood samples were tested for HBs Ag and anti HBs (n = 456), and anti-HCV (n =
162 randomly selected samples) with a third generation sandwich radioimmunoassay
technique. RESULTS: The students were from 20 of the 25 districts in the country,
although their distribution was not inform. A past history of hepatitis or
jaundice was obtained from 24 (5.3%) and 6 (1.3%) students respectively. None of
them had been vaccinated against hepatitis B. At least one risk factor for
hepatitis B or C was present in 32 (7%) of them. None of the samples were
positive for HBsAg or anti-HCV, and only two (0.44%) were positive for anti-HBs.
CONCLUSION: Our results support the view that exposure to hepatitis B and C seems
to be uncommon in this country, at least up to young adulthood. As most new
entrant medical students are not immune to these infections there is a strong
case to vaccinate them against hepatitis B before they are exposed to clinical
work.
PMID- 10675997
TI - Breast cancer: do histopathology reports provide adequate information for patient
care?
AB - INTRODUCTION: Many studies have shown that certain pathologic features correlate
with risk of recurrence, development of nodal and distant metastases, long term
survival and multicentricity of breast carcinoma. Such information is useful in
selection of appropriate therapy and prognostication. OBJECTIVE: To determine the
proportion of histopathology reports of breast carcinoma that provide essential
pathologic prognostic information. METHOD: All (110 mastectomy and 25 lumpectomy)
cases of breast carcinoma reported during 79-month period from January 1992 were
assessed for inclusion of tumour size, information on excision margins and 8
microscopic features. Mastectomy reports were evaluated for information on
axillary lymph node status. RESULTS: 9.6% of reports assessed included all
relevant features. All 110 mastectomy reports gave information on axillary lymph
node status. Tumour size was included in 91.1% of reports. Excision margins were
commented on in 36% of lumpectomy reports. Of the microscopic features assessed,
tumour type was included in 98.5% and histologic grade in 66.7%. In formation on
other features ranged from 28.1% for inflammatory infiltrate at the tumour-host
interface to 69.1% for nipple invasion. CONCLUSION: Reporting on basic prognostic
information falls short of the ideal. Provision of guidelines will help to ensure
the inclusion of relevant histopathologic prognostic information.
PMID- 10675998
TI - Do babies need water in Sri Lanka?
AB - OBJECTIVES: To study the prevalence of exclusive breast feeding and the reasons
for water supplementation, and investigate whether water is necessary in the
humid climate of Colombo. SETTING: Well baby clinic in De Soysa Maternity
Hospital for Women, Colombo. SUBJECTS: 200 breast fed infants born in a baby
friendly hospital between the ages of 1 and 4 months. METHODS: The study sample
was randomly selected. Sick infants and those of working mothers were excluded.
The mothers' knowledge of feeding practices was recorded in an interviewer
administered questionnaire. The infants' weights, lengths and rectal temperatures
were measured and the osmolality of urine estimated. The room temperature and
relative humidity were recorded on each day of study. The data were analysed
using the Chi-Square statistical test. RESULTS: 69% of mothers introduced
supplementary fluids within the first 4 months, because of advice from
grandmothers or relatives, thirst, hiccups or constipation. 45% had introduced
water with "rathakalkaya", a fluid traditionally given to infants in Sri Lanka.
90% of mothers had attended antenatal clinics in the De Soysa Hospital for Women.
70% of mothers who gave supplementary fluids were aware of the importance of
exclusive breast feeding. The range of urine osomolalities of exclusively breast
fed infants was 60 to 204 mosmol/kg. There were no significant differences in
core temperatures and number of times urine was voided daily, or urine
osmolalities, between exclusively breast fed and fluids-supplemented group of
infants. CONCLUSIONS: Despite delivery in a baby friendly hospital a majority of
mothers supplemented breast milk with water or other fluids during the first 4
months. The advice of grandmothers had a significant influence on early feeding
practices. Exclusively breast fed infants were found to maintain water
homeostasis under the hot, humid climatic conditions of this study.
PMID- 10675999
TI - A family with alkaptonuria showing quasidominant inheritance.
PMID- 10676000
TI - Right ventricular arrhythmogenic dysplasia in a young Sri Lankan.
PMID- 10676001
TI - Tilt table test and assessment of neuro-cardiogenic syncope.
PMID- 10676002
TI - Micropapillary serous carcinoma of the ovary: a report of three cases.
PMID- 10676004
TI - Emergency contraception.
PMID- 10676003
TI - Emergency contraception.
PMID- 10676005
TI - A preliminary study on neonatal septicaemia in a tertiary referral hospital
paediatric unit.
PMID- 10676006
TI - Vitamin D supplements in adults.
PMID- 10676007
TI - Anti-ulcer drugs may mask early gastric cancer.
PMID- 10676008
TI - [Complications after joint endoprosthesis for treatment of locomotor system
neoplasms].
AB - The authors present most common complications after tumor related joint
replacement. Twenty-six patients (9 females, 17 males) have been operated on
(mean age 22.5 years). In 19 cases osteosarcoma was diagnosed, Ewing sarcoma in 4
and there were 3 cases of chondrosarcoma. Postoperatively, superficial skin
necrosis occurred in 4 patients but healed in four weeks, full-thickness skin
necrosis in 2 and in 2 cases wound infection resulted in septic loosening of
endoprosthesis. The number of infections in our patients was low but caused delay
of chemotherapy and need for revision of the infected joint.
PMID- 10676009
TI - [Early results of densitometry around the cementless stem of the Parhofer-Monch
hip endoprosthesis].
AB - Fifty-three patients with unilateral hip arthritis (31 females, 22 males) aged
from 29 to 66 years (mean 52.1 years) after total hip replacement with cementless
Parhofer-Monch endoprosthesis underwent densitometry. The content (BMC) and
mineral density (BMD) of calcium within proximal end of the femur was evaluated
at 8-12 days postoperatively and at 6, 12 and 18 months follow-up. Early results
show various mineral changes in Gruen zones around the stem. The greatest BMC and
BMD decrease was found at 6 months follow-up in zones 1 and 7 as well as 2 and 6.
The BMC and BMD tendency to decrease gradually ceased and slightly positive
values were found in zone 3, 4 and 5 at the final evaluation.
PMID- 10676010
TI - [Using arthroscopy for dynamic assessment of the patello-femoral joint in
patients with anterior knee pain].
AB - Arthroscopic assessment of patello-femoral dynamics in 20 females aged from 15 to
23 years with anterior knee pain syndrome has been compared to MRI study done in
this group previously. Arthroscopic evaluation was done according to Lindberg et
al. The study suggests, that arthroscopy is an useful technique in evaluation of
patello-femoral instability, giving a chance for treatment of other
intraarticular disorders (if present) contributing to knee pain.
PMID- 10676011
TI - [Free vascularized joint transfer during surgery for hypoplastic thumb].
AB - Hypoplasia and aplasia of the thumb constitute approximately 11% of congenital
disorders of the upper extremity. Surgical treatment depends on type of disorder
in Blauth classification used in our Department. Soft tissue procedures and
pollicisations are performed most often. Microsurgical transplantation of
interphalangeal joint from the toe is an alternative. This paper describes a case
of microsurgical treatment in 20 years old patient with hypoplastic thumb. Two
months after surgery the range of motion in transplanted joint was between 20 and
75 degrees.
PMID- 10676012
TI - [Does delayed fracture fixation within the upper extremity influence the rate of
complications?].
AB - A series of 42 patients operated on due to humeral shaft fracture and 67 patients
with forearm bones shaft fracture were analyzed clinically and statistically. The
type of fracture was related to the time span between injury and surgery and
number of complications. Complications were divided into two groups--early ones
(skin necrosis, infection) and late ones (fixation failure, delayed union,
pseudoarthrosis). Injury to surgery time span was divided into for sections: less
than 10 h, 10-24 h, 24 h-10 d and above 10 days. Early and late complications
prevailed in patients operated within 24 hours from injury (87% of all
complications). Eleven patients with humeral fracture had fair or poor result; 8
of them were operated within 24 hours from injury. Among 18 patients with fair
and poor results after forearm fracture 13 were operated on within 24 hours from
injury.
PMID- 10676013
TI - [Percutaneous epiphyseodesis for treating limb length inequality in children -
results after termination of growth].
AB - Results of percutaneous epiphyseodesis for limb length egalization in 25 children
(10 girls and 15 boys) after termination of growth are presented. Mean age at the
surgery was 12.9 years (range 10.9-14.4 years), mean limb length discrepancy 4.3
cm (range 2-10 cm), mean follow-up was 50 months (range 14-86 months). In 17
cases distal femoral epiphyseodesis was done, in 7 cases distal femoral, proximal
tibial and fbular and in 1 case only proximal tibial and fibular epiphyseodesis
was performed. In 13 cases CT served to assess the area of removed physis. Among
complications knee hemarthrosis was encountered twice and once subcutaneous
hematoma of the lower leg occurred. At the final follow-up full range of motion
in the knee and correct axial alignment was observed in all cases. Residual limb
length discrepancy was 1.3 cm (range 0-4 cm). Between 20 and 60% of total area of
the physis was destroyed. Yearly rate of femoral bone growth inhibition was the
same in patients with 27% and 40% of physis removed.
PMID- 10676014
TI - [Ultrasonographic evaluation of the rotator cuff after its surgical
reconstruction].
AB - The aim of this paper was to evaluate ultrasonographic picture of rotator cuff
integrity after surgical reconstruction performed in 34 patients with mean follow
up 17.2 months (range 6-45 months). The lack of rotator cuff echo or
hypoechogenic area were the criteria for diagnosis of re-tear. This occurred in
16% of shoulders with isolated supraspinatus tear and in 33.3% of shoulder with 2
tendons involved. Hyperechogenic changes were noted in 35.3% of shoulders, some
thinning of the rotator cuff in 23.5%, while both of these changes in 14.7%. The
thinning of the rotator cuff was classified as pathologic if there was difference
between diameter of rotator cuff measured in 6th to 8th postoperative week and
diameter measured at the time of follow-up. Ultrasonographic examination offers
critical evaluation of both surgical result and postoperative physical therapy
protocol.
PMID- 10676015
TI - [Radiologic changes in hip joints of patients with hemophilia].
AB - Historical overview and contemporary understanding of hemophilia and hemophilic
arthropaty is presented. Avascular necrosis of the femoral head occurs in 7% of
hemophilic patients. Clinical description and hip radiographs of 6 patients were
presented and discussed according to Nuss modification of Arnold-Hilgartner
classification.
PMID- 10676016
TI - [Cross-leg pedicled fibular graft--a new reconstructive method with vascularized
bone graft].
AB - Theoretical foundations for cross-leg pedicled fibular graft, a new method for
reconstruction within lower extremity with vascularized bone graft is presented.
The flap can be raised in two fashions depending on blood flow direction in the
pedicle. In case of regular flow up to 18 cm of fibula is available; in reversed
pedicular flow over 20 cm of fibula can be harvested. An arch of rotation of the
flap reaches mid-thigh and peripheral part of the lower extremity. Cross-leg
pedicled fibular graft can be used for concomitant soft tissue defect
reconstruction as well. Crossing and immobilization of both lower extremities is
necessary for 4 weeks. No microsurgical procedure is required. Skin island of the
fibular flap or narrow muscular cuff left around fibular vessels is sufficient to
protect the pedicle. Main indication for cross-leg pedicled fibular flap include
patients with major lower extremity injury with axial vessels damage or with
history of previous trauma and thrombosis, and patients after bone tumor
resection who had chemotherapy and/or radiotherapy. The indications may be
markedly broadened especially in centers with no access to microsurgery. The
results of this method are very encouraging so far.
PMID- 10676017
TI - [A modified direct lateral approach for total hip arthroplasty].
AB - Literature based review of lateral hip approach (MacFarland, Osborne)
modifications offered by Bauer, Harding, Mills, Moscal and Mann is presented.
Surgical technique for the Moscal and Mann approach is described. The approach
allows easy access to the proximal femur for reaming, cementing, prosthesis
orientation and leg-length discrepancy correction. It offers visualization of the
joint superior to all non transtrochanteric approaches and is successfully used
for both primary and revision THR.
PMID- 10676018
TI - [Clinical use of underoot pressure measurements done with the Emed-system for
diagnosis of foot deformities and disorders].
AB - Emed-system is used for assessment of pressure distribution under the foot at
standing and walking since 1985. The method is non-invasive, useful in diagnosing
and monitoring of treatment for foot disorders both in children and adults. It
may be utilized in orthopedics, traumatology, rehabilitation, rheumathology and
diabetology.
PMID- 10676019
TI - [A method for gait analysis--preliminary report].
AB - A preliminary report on new method for gait evaluation is presented. Specifically
designed shoes with built-in sensors allow for registration of the data during
free gait on normal surface; collected data is than analyzed in PC based system.
Twenty-four patients (16 females, 8 males, mean age 58 years) with hip arthritis
treated at Orthopedic Department were included in this study.
PMID- 10676020
TI - [Covering soft tissue defects after tumor resection around the knee with
vascularized musculo-cutaneous and fascio-cutaneous flaps].
AB - The application of musculo-cutaneous of the medial head of gastrocnemius for
covering skin and soft tissues defects following total knee replacement in
treatment for proximal tibial osteosarcoma in 4 patients is presented. In 2
patients the fascio-cutaneous flaps originated from lower leg were used to cover
defects of anterior aspect of the knee after resection of dermatofibrosarcoma of
the patellae and fibrohistiocytoma localized in proximal tibia.
PMID- 10676021
TI - Amputations and prosthetics.
AB - The author presents in a condensed way an overview of the principles of limb
amputations and further treatment of patients who underwent such a procedure. The
metabolic cost of walking, load transfer, and wound healing are reviewed in a
concise manner. Particular attention is given to blood supply to the wound and
methods to determine adequate perfusion with a clear analysis of the pro and cons
of the Doppler method. Pediatric amputations, because of their specificity, are
considered apart. Disarticulation of limbs is the method of choice in children,
because of it retains growth potential of the bone and prevents bony overgrowth
of the stump. The article discusses the main indications for limb amputations:
trauma, peripheral vascular disease, musculoskeletal tumors and gas gangrene. In
every case the specificity of the amputation is considered by the author.
Postoperative care is also presented, with a short description of possible
complications. Pain is the most common and treatment strategies should be similar
to those used in treating patients with major reflex sympathetic causalgia.
Edema, joint contracture, wound failure and dermatologic problems are all shortly
reviewed. The last part of the article treats with the principles of prosthetics
in both the upper and lower limb. These principles are presented basing on the
level of amputation: for the upper limb hand, transradial, transhumeral
amputations and shoulder disarticulation. For the lower limb foot and ankle,
transtibial and transfemoral amputations are considered.
PMID- 10676022
TI - [Ruptured hepatocarcinoma. Report of 22 cases].
AB - STUDY AIM: Spontaneous rupture of hepatocellular carcinoma (HCC) causing massive
hemoperitoneum is a critical and life threatening complication. The study aim was
to report a retrospective series of 22 cases observed in the same centre.
PATIENTS AND METHODS: From 1978 to 1998, 22 patients (18 males and four females,
mean age: 63 years, range: 18-83) were treated for ruptured H.C.C involving a
cirrhotic liver in 17 cases and a normal liver in five cases. In 14 cases, the
diagnosis of acute hemoperitoneum indicated an immediate laparotomy. The site of
rupture was predominant in the left lobe (eight cases). The surgical treatment
was: left lobectomy (n = 7), right hepatectomy (n = 2), excision (n = 4), hepatic
artery ligation (n = 5), direct hemostasis (n = 4). RESULTS: Postoperative
mortality was 45.4%. Among the 12 survivors, nine died within a delay of 6 to 29
months. Three patients were still alive at the time of this study at 32, 40 and
66 months. CONCLUSION: Acute rupture of HCC requires emergency procedures with a
high risk of mortality. Curative operation with hepatic resection is the most
effective procedure but is not often feasible because of the spreading of the
tumor or/and the cirrhosis. The ligation of hepatic artery seems to be an
alternative procedure to obtain an immediate hemostasis. Fissuration allows
performance of complementary explorations and possibly preoperative arterial
embolization with better immediate results.
PMID- 10676023
TI - [Hepatectomy in intrahepatic lithiasis].
AB - STUDY AIM: The aim of this study was to report the immediate results of a series
of 65 hepatic resections for hepatolithiasis performed in Vietnam. PATIENTS AND
METHOD: From 1986 to 1998, 44 men and 21 women (mean age: 40 years) underwent
hepatic resection for hepatolithiasis. Fourty patients had previously undergone
one or several operations for hepatolithiasis. The procedure was performed on
emergency in 25 patients. Indications for hepatic resection were: angiocholitis
and liver abscess in 22 cases, stones closely inserted in the biliary duct in 20
cases, hemobilia in 12 cases, stones located above a biliary stricture in 8 cases
and stones associated with a postoperative biliary fistula in 3 cases. Liver
resections (minor in 61 patients, including 55 left lobectomies, and major in 4
patients) were performed through transhepatic approach according to the Ton That
Tung technique and followed by an external biliary drainage with a Kehr tube.
RESULTS: There were 6 postoperative deaths (9%), 3 due to septic shock, 2 to
cachexia, and 1 to liver failure. The 15 patients with complications recovered
with conservative therapy. Bile infection was present in 93%, mostly with
Escherichia coli and Enterobacter. Pigmented stones were usually found.
CONCLUSION: Vietnam is a country with high incidence of hepatolithlasis. Hepatic
resection is an adequate treatment for localized intrahepatic bile duct stones
when the involved segment including biliary strictures and calculi can be
completely removed. The procedure may be performed on emergency for liver
abscess, or hemobilia.
PMID- 10676024
TI - [Selective use of vascular clamps in major hepatectomy].
AB - OBJECTIVE: To report the results of a selective use of vascular occlusions in
major hepatectomies according to the size and location of the hepatic lesion.
BACKGROUND: Total vascular exclusion (TVE) and portal triad clamping (PTC) ensure
efficient hemostatic effect but lead to warm ischemia of the liver. Lobar
vascular occlusion (LVO) avoids warm ischemia of the remnant liver but could
result in increased blood loss. PATIENTS AND METHODS: Sixty consecutive major
hepatectomies were studied. TVE was applied in 22 patients with large lesions (=
10 cm) or lesions with connections to the major hepatic veins or inferior vena
cava. PTC (n = 15) and LVO (n = 23) were applied in remaining cases. RESULTS:
Clamping method was efficient in 87%, 93% and 100% for LVO, PTC and TVE,
respectively. Median blood transfusions were 0.3 and 2 units for LVO, PTC and
TVE, respectively. Postoperative aminotransferase peak value was significantly
lower after LVO than after PTC or TVE, while those peaks were not statistically
different with these latter two methods. Postoperative prothrombin time fall
value was identical in the three groups. Mortality was 3.3% (2/60) and was not
influenced by the type of clamping, but both deaths and most complications
occurred in patients with abnormal underlying liver parenchyma. CONCLUSION:
Provided that adequate techniques are used, the need for blood transfusions is
more dependent on the characteristics of the resected tumor than on the type of
clamping used. Total vascular exclusion does not create more ischemic injury to
the liver than portal triad clamping and it should be recommended for the
resection of large or strategically located tumors. Other tumors can be resected
in more than 80% of the cases with LVO, thus avoiding ischemia to the remnant
liver. With the control of hemorrhage, pathology of underlying liver parenchyma
has emerged as the main prognostic factor in major liver resections.
PMID- 10676025
TI - [Adjuvant intra-arterial chemotherapy after curative resection of liver
metastasis from colorectal cancer. Results of a pilot study in 30 patients].
AB - OBJECTIVE: Five-year survival after simple resection of liver metastases from
colorectal carcinoma ranges from 20 to 40%. The aim was to study the reliability
and long term results of adjuvant intra-arterial chemotherapy after resection of
colorectal liver metastases. PATIENTS AND METHOD: From 1991 to 1997, 30 patients
after a complete resection of liver metastases from colorectal cancer were
included (16 men, 14 women, mean age: 62 years). There were 2 stage I, 19 stages
II, 2 stages III, 5 stages IV and 2 stages V according to Gayowski staging
system. During laparotomy, a catheter was placed in the gastroduodenal artery in
order to perfuse the proper hepatic artery. Chemotherapy included 5 Fluorouracil
(12 mg/m2) and Leucovorin (200 mg/m2) and was administered once a week during six
months. Mean follow-up was 52 months. RESULTS: Adjuvant intra-arterial
chemotherapy had to be interrupted before six months in 9 patients because
leukopenia (n = 2), infection or obstruction of the catheter (n = 5), duodenal
migration of the catheter (n = 1) and occurrence of multiple extrahepatic
metastases (n = 1). No death was in relation with the method. Five-year survival
rate was 41.8% for the global series. Five-year disease free survival rate was
21.4%. Causes of death were: hepatic recurrence only (n = 3), extrahepatic +
hepatic recurrence (n = 4), extrahepatic recurrence (n = 2). Two patients died of
another carcinoma (esophagus, ovary), without evidence of recurrence of the
colorectal carcinoma. At the present, there is a recurrence in 4 living patients.
CONCLUSION: Although the benefit on survival is not significant, these results
suggest a longest time of remission in patients with adjuvant intra-arterial
chemotherapy. Trials comparing and/or combining this method to intravenous
chemotherapy should be proposed in patients after resection of colorectal liver
metastases.
PMID- 10676026
TI - [Mycotic aneurysm after kidney transplantation].
AB - PURPOSE: The study aim was to report six cases of mycotic aneurysms in renal
transplant patients and to review the literature on this subject. PATIENTS AND
METHODS: Six patients, aged from 13 to 59 years, who had undergone renal
transplantation 4 months to 16 years earlier, developed a mycotic aneurysm after
bacteremia. The diagnosis was based on morphological investigations
(echotomography, arteriography, spiral computed tomography) and bacteriological
studies (blood culture, culture of the aneurysmal wall and content). The aneurysm
was located in five cases at the anastomosis of the renal artery with the iliac
axis, and in one case on the popliteal artery and tibioperoneal trunk. All
patients were treated surgically: five reconstructions were performed using two
arterial iliac prostheses, three hypogastric artery autografts and one saphenous
vein graft (combined with an iliac prosthesis); one repair was impossible because
of profuse local suppuration, and endoaneurysmorraphy with multiple ligatures of
the popliteal vessels was performed. Postoperative radiological control was
performed in all cases of arterial repair. All patients received antibiotic
therapy during three to six months after the operation. RESULTS: No postoperative
mortality occurred. All kidney transplants were salvaged. Anatomical results of
arterial reconstructions were satisfactory in all cases and remained so during
the follow-up. CONCLUSIONS: Mycotic aneurysms after renal transplantation are
rare since only six observations with a kidney transplant in place have been
published in the literature with a single long-lasting kidney salvage. Surgical
treatment is mandatory to prevent rupture. Survival of patients occurred
exclusively in operated cases.
PMID- 10676027
TI - [Pulmonary aspergilloma: results of surgical treatment. Report of a series of 206
cases].
AB - STUDY AIM: The aim of this retrospective study was to report the results of the
surgical treatment in 188 patients operated on for pulmonary aspergilloma in a
series of 206 patients observed in Morocco. PATIENTS AND METHOD: From 1982 to
1998, 206 patients were treated for pulmonary aspergilloma in the same hospital;
188 were operated on and surgery was contraindicated in the other patients with
general or respiratory failure. Hemoptysis was the main symptom, present in 190
patients (92%). Surgery was performed on principle with 108 lobectomies, 38
segmentectomies, 18 lobectomies and segmentectomies, 21 pleuropneumonectomies and
3 thoracoplasties. RESULTS: Postoperative complications occurred in 36% of the
patients including: pyothorax (n = 15), hemothorax (n = 10), rehabitation defects
(n = 17) and respiratory failure (n = 10). Reoperation was necessary in 6
patients. Postoperative mortality rate was 6.4% (12 patients including 5 treated
by pleuro-pneumonectomy). CONCLUSION: The surgical treatment, in spite of its
high morbidity, has to be proposed to all patients with pulmonary aspergilloma,
even in asymptomatic patients when there is no surgical contraindication.
Pleuropneumonectomy is a very high risk procedure and its indications must be
restricted. Thoracoscopy was rarely performed in this series.
PMID- 10676028
TI - [Use of lanreotide in the prevention of pancreatic fistula after cephalic duodeno
pancreatectomy. Preliminary study].
AB - STUDY AIM: Dehiscence of pancreatic anastomosis is the main complication after
pancreatoduodenectomy. The efficacy of somatostatin analogue to prevent
complications after pancreatic resections is at present well-established by
several randomized trials. The aim of this preliminary prospective study was to
assess the role of lanreotide (a long acting somatostatin analogue) in this
field. PATIENTS AND METHOD: Forty patients with pancreatic head tumour have been
included in a prospective study. Criteria for pancreatic fistula were: high
concentration of amylase in the drainage fluid (> 3 times that in the serum), or
intra-abdominal fluid collection adjacent to the pancreatic anastomosis, or
reoperation (or postmortem verification) showing an anastomotic dehiscence. The
patients received 12 h before the operation 30 mg of lanreotide intramuscularly.
RESULTS: Of the 40 patients included prospectively, 34 underwent a pancreatic
resection. Parenchyma of pancreatic remnant was crumbly in 28 cases. Six patients
experienced a pancreatic fistula (17.6%) which healed in all cases. CONCLUSION:
This preliminary study shows clearly the feasibility of a long acting
somatostatin analogue (lanreotide) to prevent pancreatic fistula after
pancreatectomy. This agent appears simple to use and its efficacy needs obviously
to be assessed by randomized trials.
PMID- 10676029
TI - [Treatment of hemorrhoids with the Longo technique. Preliminary results of a
prospective study on 94 cases].
AB - AIM OF STUDY: The aim of this multicenter prospective study was to report the
early results of Longo procedure for the surgical treatment of hemorrhoids
disease. PATIENTS AND METHOD: From April 1998 to July 1998, 94 patients (60 men
and 34 women with a mean age of 47 years) were treated according to Longo
procedure for a mucosal prolapse (12 grade II, 63 grade III, and 19 grade IV).
All patients were evaluated at 2 and 6 postoperative months. The technique
consisted in the reduction of mucosal and hemorrhoidal prolapses with a circular
suturing device. RESULTS: Postoperative morbidity rate was 6.3% (n = 6). A rectal
bleeding occurred within 12 hours after surgery in five patients. The mean
postoperative length of hospital stay was 36 hours (range: 24-72 hours). The only
antalgic prescribed was paracetamol. Local care was not necessary in any patient.
After 6 months, 89 patients (94.7%) were very satisfied, three patients (3.2%)
were satisfied (rectal sub-mucosal abscess in one case, functional troubles in
two cases) and two patients (2.1%) were not satisfied (persistence of mucosal
prolapse). CONCLUSION: These preliminary results are satisfactory but need to be
confirmed by a prospective randomized trial, comparing Milligan Morgan procedure
and Longo procedure.
PMID- 10676030
TI - [Surgical treatment of colonic cancer after 75 years of age. Study of a series of
240 patients].
AB - AIM OF THE STUDY: The aim of this retrospective study was to report the results
of the surgical treatment for large bowel cancer in patients over 75 years of
age. PATIENTS AND METHOD: From 1985 to 1996, 240 patients. 114 men and 126 women,
aged 75 years or over (mean age: 82, range: 75 to 95 years) underwent surgical
treatment for large bowel carcinoma. Tumors were located in the right colon (n =
120), left colon (n = 100), transverse colon (n = 5), or were multiple (n = 15).
Clinical presentation was failure of general condition (25%), intestinal
obstruction (20%), rectal bleeding (20%), abdominal pain (17%). ASA score was I
(n = 1), II (n = 69), III (n = 134), or IV (n = 36). Emergency surgery was
mandatory in 110 cases (43 urgent and 67 delayed procedures) and 130 patients
underwent elective surgery. Surgical resection was performed in 221 cases,
including 177 cases with curative intent (67%). Surgical procedures included
right colectomy (n = 119), left colectomy (n = 59), transverse colectomy (n = 9)
or subtotal colectomy (n = 31). Histopathological staging was Astler--Coller A (n
= 8), B (n = 116), C (n = 54) et D (n = 62). RESULTS: The postoperative course
was uneventful in 157 cases (65.4%). Medical complications occurred in 46
patients with 34 deaths; and surgical complications in 39 patients with 20
subsequent reoperations and 15 deaths. The overall postoperative mortality rate
was 20.4% (n = 49). Postoperative mortality rate was higher after emergency
operations (32.7% vs 10%), higher with the level of ASA grading (class II: 8.6%,
Class III: 17.1%, Class IV: 38.8%), higher in patients over 90 years (37.4% vs.
19.1%) and in patients without surgical resection (42% vs 18.5%). Disease
specific 5-year survival rate was 45% and did not differ when compared to
patients younger than 75 years (42%, data not reported). CONCLUSIONS: Patients
older than 75 years remain a high risk group, specially if operated on emergency.
Nevertheless, age is not a limiting factor in the surgical treatment of colon
cancer. Prognosis is mostly depending on ASA grading. Colectomy with curative
intent has to be performed when possible.
PMID- 10676032
TI - [The first dissecting room for surgeons in Paris].
PMID- 10676031
TI - [Impact of learning and experience on the laparoscopic treatment of
gastroesophageal reflux].
AB - STUDY AIM: Laparoscopic treatment of gastroesophageal reflux disease (GERD) by
partial (PF) or total (TF) fundoplication is the most appropriate surgical
treatment after failure of medical treatment. The aim of this study was to
compare the results of the same series in three consecutive periods in order to
determine the effects of the learning curve and experience on the technique and
outcome. PATIENTS AND METHODS: From January 1993 to January 1998, 150 patients
(84 men and 66 women) with a mean age of 52.2 years (18 to 78) were included.
Three groups of 49, 50 and 51 patients were chronologically defined. The
comparison was established on the following criteria: the operative technique;
the conversion rate; the mortality and morbidity rate; the duration of surgery
and hospitalization and the results with short and medium follow-up. RESULTS: The
three groups were comparable with respect to patients and GERD characteristics.
One hundred and thirty two patients had a TF and 18 had a PF. Rossetti's type TF
became the reference procedure (80.3% in group III) and closure of the
diaphragmatic crura was performed systematically in group III (100%). The
duration of surgery was significantly reduced between group I and the two other
groups (138, 100, 80 min). The rate of conversion decreased from 10.2% to 4% and
then 0%. The average duration of hospitalization decreased from 5.8 to 4.2 days
(p = 0.01). There was no mortality and the morbidity rate decreased from 14.3% to
4% and then 0%. Seven cases of recurrence occurred (4.6%), 5 in group I (10.2%),
2 in group II (4%), and 0 in group III, (with a shorter follow-up). CONCLUSION:
The effect of the learning curve has to be taken into account in the training of
surgeons (within experienced departments, with "guidance" during initial
interventions) and also in the evaluation of results, in order to allow a more
accurate comparison between the different treatments for GERD.
PMID- 10676033
TI - [Long-term functional results of Nissen fundoplication with laparotomy and
laparoscopy].
PMID- 10676034
TI - [Long-term results of biliary repair of laparoscopic bile duct injuries].
PMID- 10676035
TI - [Carotid endarterectomy with patch versus reversion and reimplantation
endarterectomy: randomized prospective study].
PMID- 10676037
TI - [Theory and practice of daily prescription and gynecologic consultation for
treatment of hyperandrogenism. Indications and contraindications].
PMID- 10676036
TI - [The HPV test and clinical practice].
PMID- 10676038
TI - [What remains of the postcoital test?].
PMID- 10676039
TI - [Are cervicovaginal smears feasible in women over 65 years under hormone
replacement therapy?].
PMID- 10676040
TI - [Should cytological screening for cervical cancer be stopped after menopause?].
PMID- 10676042
TI - [Cytological screening of uterine cervical cancer by samples in liquid medium
(CytoRich). Preliminary study of a series of 111 292 patients].
AB - We report on the preliminary results of a series of 111,292 patients who
benefited from a liquid medium sample (CytoRich) for cervical cancer screening.
The number of dubious or limited smears was reduced by 0.03% and 0.53%
respectively. The junction zone was better explored, and metaplastic changes were
observed in 35.71% of the cases. This method improved the identification of low
grade lesions by +56% (2751/111,292; 2.47%) and of high-grade lesions by +75%
(860/111,292; 0.77%), with a reduction in the number of ASCUS/AGUS by -44%
(2065/111,292; 1.85%). This preliminary study confirms the results already
published. The results demonstrating cytohistological correlation should prove to
be a decisive factor, enabling the testing of the sensitivity and specificity of
this technique. It will then be possible to envisage a future 'new paradigm' for
screening cervical cancer as the result of a liquid medium sample, computer
assisted screening and HPV viral identification by Hybrid capture II.
PMID- 10676041
TI - [Diabetes before pregnancy, apropos of 143 cases].
AB - OBJECTIVE: The authors want to appraise the management of diabetes prior to
pregnancy in a local population treated in the Lille University Hospital. METHOD:
This is a retrospective study of 143 pregnancies occurring in 111 patients with
diabetes prior to pregnancy, between 1987 and 1997, in the Obstetrics Department
at the Lille University Hospital. RESULTS: Only one-third of the patients
benefited from preconception management; the stability of diabetes during the
first trimester was satisfactory in 50% of the cases. The maternal complications
are represented by preeclampsia (20%), metabolic complications specific to
diabetes (hypoglycemia, ketoacidosis), the aggravation or the emergence of a
retinopathy (10%) and polyhydramnios (19%). Concerning the termination of the
pregnancies, of the 147 fetuses (four twin pregnancies), 140 newborns in good
health, two neonatal deaths, three in-utero deaths and two therapeutic
terminations of pregnancy were observed. The fetal malformation rate was 9.5% (14
cases/147). The cesarean section rate was 63%, whereas the fetal macrosomatia
rate was 35%, with dystocia in 26% of the deliveries (outside of planned
cesareans). Three shoulder dystocia were observed (two requiring the Jacquemier's
maneuver and one with transitory plexus brachial palsy for a newborn weighing
5,650 g). CONCLUSION: The authors conclude that preconception management (one
third of the patients in this series) and management of during the first
trimester of pregnancy (50% in this series) was insufficient. This fact is
perhaps due to the confusion, for many practitioners, with gestational diabetes,
which is a very mediatized affection, though much less severe for the fetus and
mother.
PMID- 10676043
TI - [Effects of raloxifene on bone loss and fracture risk in the menopausal woman].
AB - The relevance and efficacy of long-term estrogen therapy is well established,
though some undesirable side effects and contraindications persist. Raloxifene,
the first selective estrogen receptive modulator (SERM) tested in phase III
trials, offers a choice alternative. It increases bone mineral density, lowers
serum lipid concentrations and reduces vertebral fractures.
PMID- 10676044
TI - [Anatomoclinical correlations of endometriosis].
AB - This is an epidemiological study of 1,498 patients who underwent laparoscopic
surgery for different reasons. Between 1989 and 1996, 308 cases of endometriosis
were identified among 1,498 patients who underwent laparoscopic surgery. One
hundred and five patients were admitted for pelvic pain, 794 for infertility, 319
patients had both on admission, and 280 were admitted for non-gynecologic
complaints. The incidence of endometriosis is related to the chief complaint on
admission. This disease has different clinical manifestations, different
locations and different stages. The mean age in our series is greater than that
reported by the literature. The symptoms are related to the location of the
lesions but not the stage of the disease. Unlike pelvic pain, infertility is
correlated to the stages of the disease.
PMID- 10676045
TI - [Proximal tubal unblocking by selective salpingography, apropos of 8 cases].
AB - Proximal tubal desobstuction by selective salpingography: through a study of
eight cases, the authors give their first results about tubal desobstruction by
selective salpingography.
PMID- 10676046
TI - [Inflammatory and/or locally advanced breast cancers. Difficulty evaluating the
response to initial chemotherapy].
AB - At the Tenon Hospital (Paris), 48 inflammatory or locally advanced breast cancers
were treated by neoadjuvant chemotherapy (three different protocols), followed by
surgery (mastectomy or tumorectomy and axillary dissection). The histological
data of the specimens are analyzed with regard to the clinical and radiologic
evolution. Twenty complete clinical responses (41%), 22 partial clinical
responses (45%), and no response in six cases (14%) were observed. Histology
demonstrated residual tumors in 42 cases (87.5%), even in the case of complete
clinical response (14 cases), without notable change of the grade (SBR). Lymph
node clearance demonstrated positive nodes in 38 cases (79%). Despite its great
agreement with clinical examination, mammography does not predict the existence
of histological residual tumors after initial chemotherapy. Chemotherapy allowed
local treatment, but can rarely sterilize the tumor completely.
PMID- 10676047
TI - IMS to support Medicare lawsuit.
PMID- 10676048
TI - Reporting impaired drivers.
PMID- 10676049
TI - Antibiotic resistance: a critical issue in Iowa.
PMID- 10676050
TI - OSHA focuses on safe needle devices.
PMID- 10676051
TI - Is your office handicap compliant?
PMID- 10676052
TI - Don't jump the gun....
PMID- 10676053
TI - [Pediculosis and phthiriasis].
PMID- 10676054
TI - [Viral skin infections in children].
PMID- 10676055
TI - [Skin and sun: prevention and risks].
PMID- 10676056
TI - Determinants of use of maternal-child health services in rural Ghana.
AB - This study uses data from the Ghana Demographic and Health Survey (GDHS) of 1993
to examine factors determining the use of maternal-child health (MCH) services in
rural Ghana. The MCH services under study are: (1) use of a doctor for prenatal
care; (2) soliciting four or more antenatal check-ups; (3) place of delivery; (4)
participation in family planning. Bivariate and multivariate techniques are
employed in the analyses. The analyses reveal that the use of MCH services tends
to be shaped mostly by level of education, religious background and region of
residence, and partially by ethnicity and occupation. The implications of these
results are discussed.
PMID- 10676057
TI - Women's work and fertility in a sub-Saharan urban setting: a social environment
approach.
AB - Data from three separate studies conducted in Maputo, Mozambique, in 1993 are
used to analyse the relationship between the type of social environment in which
women work and their fertility and contraceptive use. The analysis finds that
women who work in more collectivized environments have fewer children and are
more likely to use modern contraception than women who work in more
individualized milieus and those who do not work outside the home. Most of these
differences persist in multivariate tests. It is argued that collectivized work
environments are most conducive to diffusion and legitimation of reproductive
innovations. In contrast, individualized environments tend to isolate women and
therefore may retard their acceptance of innovative fertility-related behaviour.
PMID- 10676058
TI - Hysterectomy is associated with postmenopausal body composition characteristics.
AB - The impact of hysterectomy without oophorectomy and with no malignant purpose on
body composition and postmenopausal weight gain was tested in 184 Viennese
females aged between 47 and 57 years (mean 52.9). Hysterectomized women were
significantly heavier than those who experienced a spontaneous menopause
(controls). The amount of fat tissue, especially in the abdominal region, was
significantly higher in hysterectomized women. Furthermore, they were reported to
have experienced a significantly higher weight gain since menopause (9.1 versus
6.0 kg). No significant differences in bone mass were found. Psychological stress
factors and hormonal changes following hysterectomy are discussed as possible
causes of these differences.
PMID- 10676060
TI - The association between health-related behaviours and the risk of divorce in the
USA.
AB - This study investigates the link between health-related variables and risks of
divorce. The findings indicate that physical characteristics associated with poor
health--namely, obesity and short stature--are not significantly related to risks
of marital dissolution for either men or women. On the other hand, risk-taking
behaviours--such as smoking and drug use--are strongly related to higher risks of
divorce for both sexes. Overall, the results emphasize the need to accommodate
health-related variables in the dominant economic and social psychological
theories of marital dissolution.
PMID- 10676059
TI - Breast-feeding, diarrhoea and sanitation as components of infant and child
health: a study of large scale survey data from Ghana and Nigeria.
AB - Using Demographic and Health Survey datasets from Ghana and Nigeria, this study
examined whether the protective effects of breast-feeding are greatest where the
poorest sanitation conditions prevail. It was found that mixed-fed infants aged
between 0 and 11 months tend to have a higher risk of diarrhoea than fully breast
fed children, while the risk of diarrhoea among weaned infants is twice that of
mixed-fed infants. The probit regression models employed in the analysis were
used to predict the probability of diarrhoea associated with each breast-feeding
pattern for both 'poor' and 'good' sanitation areas. It was found that the risk
of diarrhoea among mixed-fed infants in the poor sanitation areas tends to be
high while the same risk among fully breast-fed infants tends to be minimal. In
essence, the health risks of mixed feeding are real, particularly for infants
aged less than 7 months, and are even worse for those weaned before 6 months of
age.
PMID- 10676061
TI - The impact of co-resident spouses and sons on elderly mortality in rural
Bangladesh.
AB - This paper uses prospective data from the Matlab surveillance system in rural
Bangladesh to demonstrate that initially co-resident spouses and sons have a
major impact on the subsequent mortality of old people, with significant
differences by the sex of the elderly person, and the age of the son. Spouses
significantly reduce mortality by similar magnitudes for both elderly men and
women. On the other hand, co-resident adult sons reduce mortality for elderly
women much more than for elderly men, with younger sons being more beneficial
than older sons. Furthermore, both married and unmarried females appear to
benefit equally from co-resident adult sons. Finally, this analysis suggests that
the impact of spouses and sons on mortality in old age is not substantially
mediated through changes in elderly economic status.
PMID- 10676062
TI - Provider knowledge about emergency contraception in Ghana.
AB - In 1996, the Ministry of Health in Ghana included emergency contraception (EC) in
its newly issued National Reproductive Health Service Policy and Standards. A
short survey was conducted in the summer of 1997 to evaluate health providers'
knowledge of EC. Of the 325 providers interviewed, about one-third (34%) had
heard of EC. No provider had sufficient knowledge to prescribe EC correctly. A
well-coordinated training programme for providers will have to precede successful
introduction of EC in Ghana. Moreover, a dedicated product may be critical for
the successful introduction of EC in a country like Ghana, where provider
knowledge is low.
PMID- 10676063
TI - Contraceptive failure: levels, trends and determinants in Matlab, Bangladesh.
AB - This study investigated the levels, trends and determinants of contraceptive use
failure in Matlab, Bangladesh, using a set of prospective data on 25,960 women of
reproductive age. The data were extracted from the Record Keeping System (RKS) of
Matlab for the period 1978-94. If there was any live birth during the use or
within 7 months after the discontinuation of use, it was considered as a failure.
The life table technique and hazard model were used as analytical tools. The
results suggest that use-failure for pills, IUDs (TCu 200) and injectables and
other temporary methods increased from 1978 to 1988, but began to decline after
1988. The cumulative probability of first-method failure within 1 year of method
acceptance of the cohort of 1990-94 acceptors was 12.9% for pills, 2.0% for IUDs,
0.5% for injectables, 22.0% for condoms and 13.4% for 'other' methods (sampoon,
foam, jelly and traditional methods). For pills, condoms and 'other' methods, the
likelihood of failure declined with the duration of use; by contrast, the
probability of an IUD failure increased over time, peaking at 3 years of use. The
injectables maintained a low likelihood of failure regardless of the duration of
use. The quality of Community Health Workers' (CHWs) performance was associated
with the risk of failure of all temporary methods except condoms; women's
background characteristics associated with failure varied by method. The effect
of the quality of the CHWs' performance and the background variables on failure
did not change much over time. It is felt that contraceptive failure deserves the
serious attention of programme managers and policy makers to make the Bangladesh
national family planning programme more successful.
PMID- 10676064
TI - Fertility and population policy in two counties in China 1980-1991.
AB - A survey of women in two highly developed rural counties of China, Sichuan and
Jiangsu Provinces, was carried out in late 1991, to gain information about
demographic and economic change between 1980 and 1990. Three separate surveys
were conducted: the first a questionnaire administered to married women aged 30
39, eliciting information about childbearing and contraception, as well as the
social and economic background of the respondents; the second, focus group
interviews emphasizing the motivation for childbearing. Official information
about the selected villages, townships and counties was also collected. National
level data in 1987 show that individual reproductive behaviour in China failed to
conform to a universal, effectively implemented, population policy. They imply
either a spatial range of policies, or great diversity in the demand for
children, or perhaps a combination of both. Such diversity in reproductive
behaviour is also found in the study area. The purpose of the analysis was to
examine the diversity in reproductive behaviour and contraceptive practice, and
to discover whether differentials are influenced by area, or else exist between
individuals within areas. If the former, then the explanation may be found in
differences in policy formulation and implementation between areas: and if the
latter, to demand for children, or else differential application of policy
restrictions. The main findings were that: (1) the explanation of the pattern of
fertility and contraceptive use is to be found at the individual level (within
locations) rather than in policy differences between administrative units; (2)
the association between income and number of children is negative, as is that
between income and the propensity for uniparous women to remain unsterilized. The
theory that privilege may be exercised to gain concessions from birth planning
cadres is therefore not supported; (3) ideal family size differentials are
largely absent, showing that social (education) and economic (income, occupation)
characteristics are not responsible for differences in reproductive motivations,
and implying that the nature of the demand for children is very different from
that in most rural areas of the Third World; (4) data on ideal family size by sex
of the existing offspring indicate only a weak preference for sons. The low
demand for children, and the weak son preference, may both be explained by the
social acceptability of uxorilocal marriages, and of village endogamy, together
with the prohibitive costs of children, and especially of sons. This partly
results from the expense of education, but most mothers emphasize marriage costs.
It is speculated that the circumstances responsible for the escalating costs of
children in the two countries are likely to pertain in growing areas of the
country, with the privatization of education and health services, the declining
support of collective institutions, and the replacement of this function by
kinship networks. These on-going changes imply that any policy of reproductive
restriction for the purposes of population control is likely soon to meet with
diminishing resistance; and it may later be rendered unnecessary in the eyes of
government officials, as fulfilled reproductive intentions lead to a fertility
level below replacement level.
PMID- 10676065
TI - Crisis intervention strategies when caring for families of children with cancer.
AB - A diagnosis of childhood cancer is an unexpected life event that often
precipitates a situational crisis for all family members. Required cancer
treatments and other ongoing stressors for both child and family will
significantly disrupt the family's equilibrium and well-being. An increasingly
important role of the pediatric oncology nurse is to facilitate crisis
intervention strategies that help families adjust to the psychosocial stresses
associated with childhood cancer, yet many nurses have little or no training in
crisis theory and/or crisis intervention strategies. This article reviews family
crisis theories and outlines crisis intervention strategies that are appropriate
for the family of a child with cancer.
PMID- 10676066
TI - Choices and control: parental experiences in pediatric terminal home care.
AB - During the past decade, palliative care at home has become an alternative option
to hospital care for terminally ill children. This study describes the experience
of caring for a dying child at home from a parent's perspective. A qualitative
research design was used to conduct and analyze data. Nonstandardized, focused
interviews were conducted with 10 families. Thematic content analysis assisted in
deriving themes from the transcripts of the interviews. "Choice and control" was
the major theme that linked all the other concepts, and it appeared to be
fundamental to parental coping strategies. Most parents were willing to take
responsibility for the nursing care of their child, including administration of
intravenous medication. The patient's home was the overwhelming choice of parents
for delivery of terminal care, with most parents perceiving it as their child's
choice also.
PMID- 10676067
TI - Children's perceptions of pain during 3 weeks of bone marrow transplant
experience.
AB - Most patients undergoing bone marrow transplant (BMT) experience severe pain.
Because self-reporting is the most reliable source when assessing pain, it is
important that health care providers understand how children perceive their pain
and alleviating factors. The purpose of this descriptive, exploratory study was
to understand children's perceptions of: (a) their BMT pain, (b) interventions
effective in relieving their pain, and (c) caregivers' role in managing their
pain. The sample consisted of 20 children (50% male), age 5 to 17 years,
undergoing BMT. All study participants received continuous-infusion opioid
therapy with additional boluses as needed for pain. Using investigator-developed
structured interview guides, children were interviewed four times: on the day of
transplant, then at three weekly intervals. Data were analyzed using a content
analysis approach. In the first interview, children reported that when they hurt,
they most commonly told someone. Several children used nonpharmacologic
techniques to relieve pain. Although all had been told to expect some pain during
BMT, only one-third of the children described the kinds of pain that they
anticipated having during BMT. During subsequent interviews, the majority said
that medication worked best to decrease their pain. In the final interview, most
children said they still hurt. They reported pain predominantly in their mouth
and throat, but mentioned seven other pain sites. Anecdotal comments included
that pain management should be improved on the first BMT day and that nurses need
to teach children that it is okay to use drugs for pain. Implications for
clinical practice, education, and research are discussed.
PMID- 10676068
TI - Description of a multihospital process to develop a care path for the child with
acute lymphoblastic leukemia.
AB - This article describes the National Association of Children's Hospitals and
Related Institutions (NACHRI) collaborative group process used to create a
multihospital care path for the child with acute lymphoblastic leukemia (ALL),
and presents strategies for implementation and future direction. Although most
children in the United States with cancer are treated according to National
Cancer Institute-sponsored comprehensive protocols, there is a wide variation in
the implementation of protocols by physicians and hospitals. The development of
this care path was based on evidence from the literature, review of practice
patterns, expert opinion, and group participant consensus building. The resulting
4-day care path was organized into six categories of care (e.g., assessment
practices, diagnostic tests, teaching, and discharge planning). Discharge
criteria are stated at the beginning of the care path to emphasize the planning
process immediately on admission. Clinical outcomes, skill and knowledge outcomes
for the parent and child, and home assessment considerations are also included.
Strategies to create change and gain support of various stakeholders toward
implementation of the care path are presented. The strength of the resulting care
path is possible in large part because the multihospital group process brought
professionals from around the country together to discuss, analyze, and reach
consensus on the practices related to the child with ALL. The group process
enabled the development of a care path that goes beyond a traditional care path
developed by a single institution.
PMID- 10676069
TI - Home care requirements for children and adolescents with cancer. National
Association of Children's Hospitals and Related Institutions (NACHRI) Patient
Care Oncology FOCUS Group.
PMID- 10676071
TI - A nurse's roadmap.
PMID- 10676070
TI - Radiation somnolence syndrome.
AB - Although initially described 7 decades ago, somnolence syndrome remains a poorly
understood subacute effect of cranial irradiation. Despite the relatively
transient and benign nature of somnolence syndrome, its symptoms can be
distressing for children and caregivers. Anticipatory guidance related to
radiation-induced somnolence remains a critical nursing intervention. This
article reviews what is known about somnolence syndrome, including its causes,
symptoms, and management.
PMID- 10676072
TI - Testability of a color vision screening test in a population with mental
retardation.
AB - PURPOSE: The purpose of this study was to determine the testability of the "Co or
Vision Testing Made Easy" color vision test, marketed as a screening test for
young children, in a population of individuals with mental retardation. The test
uses simple geometric figures that are easily identified. Previously, the test
has demonstrated validity as a measure of color deficiency. METHODS: The test was
presented to Special Olympic athletes, who are individuals with mental
retardation or significant developmental delay, at four sites: the 1997 World
Winter Games in Toronto, Canada; the Texas Summer Games in Houston, Texas; the
Massachusetts Summer Games in Boston, Massachusetts; and Regional European Swim
Competition in Seville, Spain. The criteria for passing was 8 correct responses
on the first trial or 9 of 9 on the second attempt. RESULTS: Testability in
Toronto, Canada; Houston, Texas; and Seville, Spain was high--95.5%, 98.7%, and
95.7%, respectively. Testability, however, dropped to 78.8% during the Boston,
Massachusetts screening. There was no apparent difference in the testing
environment that would account for the difference. The overall rate of
testability was 93.2% for the 1078 athletes screened. The frequency of males
identified as color deficient was similar to that expected in the general
population; only two females (in Spain) failed the color vision screening.
CONCLUSIONS: The "Color Vision Testing Made Easy" color vision test was
successfully completed by a very high percentage of Special Olympics athletes.
These results suggest that this test is useful in screening this population for
color deficiencies, and that the prevalence of color vision deficiencies is
approximately the same in individuals with mental retardation as in the general
population.
PMID- 10676073
TI - Nearpoint phoria changes associated with the cessation of childhood myopia
progression.
AB - BACKGROUND: A convergent (eso) shift in near phoria associated with the onset of
myopia has been reported. METHODS: Data from two Midwestern United States
optometry practices were used to assess whether the near phoria shifted back in
the divergent (exo) direction after the cessation of childhood myopia
progression. Data were collected for myopic children who had three or more
examinations before the age of 15 years and at least one examination after the
age of 17 years. RESULTS: Refractive error data were used to calculate an index
of the age of cessation of childhood myopia progression. The phoria at the first
examination after the cessation age was designated as the baseline and was
normalized to zero. For all previous and subsequent examinations, the changes in
phoria with respect to the baseline phoria were calculated. The phoria at the
examination just after the cessation age was significantly more divergent than
those at the first, third, and fourth examinations prior to the cessation age
(1.1, 1.4, and 1.7 prism diopters, respectively). The third visit after the
cessation age was 1.8 prism diopters more divergent than the first visit after
the cessation age. Thus, these data showed an exo shift in near phoria after the
cessation of childhood myopia progression.
PMID- 10676074
TI - Keratoconus with good unaided visual acuities: two case reports.
AB - BACKGROUND: Ophthalmic evaluation of patients with keratoconus (KC) often reveals
highly myopic and irregular astigmatic refractive corrections. Irregular corneal
astigmatism and central corneal scarring in patients with KC often result in a
loss of best-corrected spectacle acuity. Rigid gaspermeable contact lenses
generally optimize visual acuities for patients with KC. CASE REPORTS: Two cases
are discussed of patients who manifested clinically diagnosed KC but unusually
good unaided Snellen visual acuities (20/25+ or better) in both eyes. CONCLUSION:
Good unaided visual acuities are not necessarily inconsistent with the diagnosis
of KC.
PMID- 10676075
TI - Circumscribed posterior keratoconus: case report.
AB - BACKGROUND: Posterior keratoconus has only a few scattered case reports in the
literature. Posterior keratoconus is characterized by a posterior stroma thinning
and a depression of the posterior corneal surface. The effect on acuity is
variable and may be related to other ocular and systemic conditions. CASE REPORT:
An African-American woman came to us with posterior concavity (corneal thinning),
with stromal scarring in both eyes and an epithelial iron ring present in the
left eye. The endothelia layer appeared intact in both eyes. Corneal topography
of the right eye demonstrated a central flattened zone with peripheral
steepening, while the left eye an inferior nasal steepened zone was present. The
patient was also diagnosed with myopic degeneration (O.D. > O.S.) as well as
cataracts. CONCLUSIONS: Posterior keratoconus generally has a minimal effect on
visual performance and requires no specific treatment. In cases in which visual
defect is severe and is attributable to the posterior keratoconus--and not other
ocular conditions, such as cataracts--penetrating keratoplasty should be
considered.
PMID- 10676076
TI - Late traumatic intraocular lens extrusion after penetrating keratoplasty.
AB - BACKGROUND: Penetrating keratoplasty places a patient at risk for wound rupture
from blunt trauma because the graft-host interface remains weakened for years
after the surgery. Violent environments, contact sports, and strenuous activity
put patients with compromised corneal structural integrity at high risk of
traumatic injury. CASE REPORT: This case report presents a 42-year-old
penetrating keratoplasty patient with a history of homelessness, polysubstance
abuse, and domestic violence. This patient experienced a ruptured globe at the
graft-host junction secondary to a direct blow by a fist, which extruded the
intraocular lens from the eye. After emergency wound closure, the graft continued
to degrade until bullous keratopathy developed. With little visual recovery
potential for this graft, a Gunderson conjunctival flap procedure was implemented
to decrease chronic ocular pain. CONCLUSIONS: After penetrating keratoplasty,
patients should be periodically reminded of the susceptibility of the graft wound
to injury from high-risk activity and violence. Constant use of protective
eyewear should be recommended to corneal transplant recipients.
PMID- 10676077
TI - Hiring a new optometrist? Be prepared!
AB - Bringing a new optometrist into a practice, even if only on an employer-employee
basis, is a complicated process that should not be taken lightly by hirer or
hiree. This article explores the many aspects of the process and the relationship
that must be understood and worked out in advance.
PMID- 10676078
TI - Staying in shape: the different roads to fitness for busy optometrists.
AB - Do you keep telling yourself it's time to get in shape? Are you adding workouts
to your list of New Year's resolutions? If you think you can't balance fitness
with a busy schedule, think again. Here are the stories of some optometrists who
have done just that (along with a couple of hard-core ODs who've taken fitness to
a higher level).
PMID- 10676079
TI - Should there be policies to restrict visitors during labor and birth?
PMID- 10676080
TI - The Cool Kids Coalition.
AB - The Cool Kids Coalition was initiated as a community response to more than 214
hospitalizations of children under the age of five for burns over a 6-year period
in one township in Long Island, NY. The coalition was started by public health
nurses in partnership with the local chapter of the National Safe Kids Campaign.
Goals included: 1. parent education regarding scald burn prevention; 2.
development of innovative interventions for those at risk; and 3, development of
innovative community approaches to scald prevention. Coalition members had
diverse backgrounds and the coalition integrated non-traditional partners in
injury control. The coalition doubled in size due to overwhelming community
interest, growing within a few months from an initial group of 15 to a well
represented group of 30. Innovative programs were implemented that reached more
than 3,000 parents, both in the community and home. Teaching was conducted with
parents in the target population in Head Start centers, homeless shelters, the
home, libraries, child care centers, a shelter for teen parents, etc. Member
agencies incorporated the booklet and materials into their individual programs.
The development of the Cool Kids Coalition illustrates the power of nursing in
community health.
PMID- 10676081
TI - A nurse practitioner model of practice in the neonatal intensive care unit.
AB - PURPOSE: The purpose of this study was to describe the practice of the nurse
practitioner (NP) in the neonatal intensive care unit (NICU) in an attempt to
define an advanced practice nursing model that is unique to NP practice in the
NICU. DESIGN: This qualitative research used an ethnographic case study design to
answer the research question: 'What is the practice model of nurse practitioners
working in the NICU?' METHODS: Seven nurse practitioners working in five level
II/III NICUs in Massachusetts and Rhode Island were interviewed and observed in
practice. Audiotaped interviews using open-ended questions and field notes from
participant observations were analyzed for patterns of behavior. RESULTS: These
nurse practitioners practiced within a model of advanced practice nursing that
emphasized health, holism, and caring within the highly technological and medical
NICU environment. CLINICAL IMPLICATIONS: A model of NP practice in the NICU is
emerging and needs further development and testing. Nurse educators and
administrators must find ways to support the nursing model in the advanced
practice nursing role in the NICU. Nurse practitioners need to be more active in
promoting a clearer understanding of their practice and contributions to the NICU
care delivery team.
PMID- 10676082
TI - Investigating the relationship between satisfaction with social support and
functional status after childbirth.
AB - PURPOSE: To explore the relationship between satisfaction with support and
functional status after childbirth. DESIGN: Prospective longitudinal survey
design. METHODS: Two hundred new mothers who had experienced a healthy pregnancy,
normal delivery and puerperium, and delivered a healthy infant between 37 and 42
weeks gestation were approached while attending primary healthcare maternal-child
health centers and immunization clinics in New South Wales, Australia.
Measurement tools included the Inventory of Functional Status After Childbirth
and the Support Behavior Inventory, and were administered at 6 weeks, 3 months
and 6 months. RESULTS: Significant increases in total mean functional scores,
scores for household responsibilities, social activities, and self-care were
noted. Although no significant correlation was found between satisfaction with
social support and functional status after childbirth, satisfaction with support
from one's partner decreased significantly during the 6-month survey period, as
did satisfaction with support from others. CLINICAL IMPLICATIONS: It could be
that providers need to assess the social support needs of their clients. A
postnatal support plan could be used by mothers to negotiate the long-term
involvement of others in household tasks and selected aspects of infant care.
PMID- 10676083
TI - African American mothers use stories for family sexuality education.
AB - PURPOSE: To examine the sexual knowledge and cultural values transmitted by
stories from African American mothers to their adolescent daughters. METHOD:
Narrative analysis. Stories from 11 mothers were recorded and transcribed by
entering interview narratives into Qualpro, a computerized data management
program, and examined using a narrative analysis method. RESULTS: Analysis
revealed that mothers used story telling as a strategy for family sexuality
education. The mothers used stories from their own experiences to accomplish
socialization/enculturation and to discourage their daughters from making the
same mistakes that they reportedly made (such as becoming pregnant during the
teenage years). Findings supported the fact that stories served as cultural
artifacts that describe the cultural pathways of a group of African Americans
mothers and daughters. IMPLICATIONS: It is important for nurses to have an
awareness of the importance of ethnocentric models for community health nursing
practice and culturally sensitive assessment tools for adolescent sexuality
education programs.
PMID- 10676084
TI - Maternal stress during hospitalization of the adopted child.
AB - PURPOSE: To identify and describe the experiences of mothers whose adopted
children are hospitalized and to compare those experiences to those of mothers
whose biological children are hospitalized. DESIGN: Comparative descriptive
design. METHODS: Mothers of hospitalized children (n = 33 adopted; n = 19
biological) completed a slightly revised version of the Parental Stressor Scale:
Pediatric Intensive Scale Unit (PSS:PICU). Adoptive mothers also completed a
questionnaire related to their perceptions of the impact of their child's
adoption on the hospitalization experience. RESULTS: Adoptive mothers perceived
statistically significantly higher levels of stress related to their child's
behavioral/emotional response to hospitalization. Children who had been with the
family for less time perceived the hospitalization as more stressful. When both
groups of mothers were considered, mothers of younger children perceived a higher
level of stress. A majority of adoptive mothers felt the adoption had an impact
on the hospitalization experience, especially related to their limited
information about their child's medical history, staff lack of knowledge about
legal issues, and concern about attachment to the child. CLINICAL IMPLICATIONS:
Nurses need to be aware of adoptive mothers' concerns related to attachment
issues, limited family medical history, and legal rights in order to provide
sensitive and effective care. Inservice education programs could be designed to
help teach all staff about these important issues.
PMID- 10676085
TI - Perceived barriers to prenatal care services.
AB - PURPOSE: The purpose of this study was to determine barriers to prenatal care
services and to determine if barriers differed by demographic characteristics in
a low-income population. DESIGN: Descriptive correlational study with 110 women
who sought prenatal care after the 20th week of gestation. RESULTS: Two items
were major barriers to seeking prenatal care: long waiting times at the time of
appointments and the cost of getting care. Significant relationships were found
based on the age and race of the women. CLINICAL IMPLICATIONS: Some identifiable
variables prevented these women from seeking early prenatal care; however, the
barriers identified are amenable to change. Strategies to reduce barriers could
include providing more culturally competent care, more timely appointments,
better use of the woman's time when appointments are kept, educating women in the
community about the availability of low-cost care, and assistance at prenatal
care sites for facilitating completion of insurance and financial applications.
Barriers to prenatal care varied by demographic group; therefore, identifying the
characteristics of the group being served seems important in efforts to decrease
barriers to care.
PMID- 10676086
TI - So you want to be an expert witness? Things you need to know.
PMID- 10676088
TI - Evidence-based practice.
PMID- 10676087
TI - Family liaison programs.
PMID- 10676089
TI - Workshop on medical education.
PMID- 10676090
TI - Medical education at the present time.
PMID- 10676091
TI - Educational innovations in the medical faculty.
PMID- 10676092
TI - Telemedicine and processing of scientific information in programs of continuing
education.
AB - Starting from some reflections on the goals of medical education, central
questions are analyzed in relation to the transfer of scientific knowledge and
the generation of more advanced cognitive approaches in professionals who follow
distance courses. The core of this article refers to the information management
processes, according to a cognitive perspective, in terms of the development of
the medical thought. With that intention, particular educational instruments are
indicated in order to achieve the internalization of the "modes of knowledge"
acquired through significant learning. The basic criterion of the educational
program is that physicians can best operate personally in the teaching processes
relatively to their particular scientific domain, because they know, better than
anyone else, what the proper methods of knowledge are: epistemology is the basis
of any special teaching, the article makes specific reference to the production
of texts of information technology. However, the general approach is applicable
to any other means that may be used in telemedicine.
PMID- 10676093
TI - Medical education: what can be learned from Europe.
PMID- 10676094
TI - Medical education in Spain.
PMID- 10676095
TI - Scientific research policy: elements for comparing Europe and Italy.
PMID- 10676096
TI - University and enterprise: the future of knowledge and research, the future of
work.
PMID- 10676097
TI - The university and the needs of the society: what professional models?
AB - An overview of the complex Italian situation and the consequences of the European
integration, which puts an emphasis on the role of research and education
involving the universities and the specific faculties, is given. Attention is
then focused on the characteristics of the evolution of the medical activity and
health services as for prevention, health education, more extensive knowledge and
the need for continuing education. Different problems are tackled and pertinent
suggestions are offered. The cultural and professional perspectives of the doctor
should be considered within a new psychosocial approach to the illness, super-
and hyper-specialization, collaboration and skills in non traditional fields.
Medical education should be based on tutorial teaching and student-centered
rather than on the traditional teacher centered-academic teaching. For better
health care medical education and training should be updated with respect to the
doctor-patient relationship as well as to the technological advances and team
work in medicine. The ethical aspects of the medical profession should be
evidenced to be able to tackle the involved problems. The main features of the
doctor of the future are the need and the difficulty of updating and life-long
learning.
PMID- 10676098
TI - Continuing education towards self-education.
PMID- 10676099
TI - Teaching the teachers.
AB - The author analyzes how the problem is dealt with in Italy in comparison with
other European countries. He also recalls the early moves taken in Italy for
teachers' training, very often started outside the university. The possible ways
of intervention are discussed for the improvement on the present situation which,
as a whole, is considered unsatisfactory, in spite of commendable individual
initiatives in a few Italian medical faculties.
PMID- 10676101
TI - The "Universita Cattolica del S. Cuore" and its educational offer.
PMID- 10676100
TI - Guidelines for medical education at the Medical Faculty of the Catholic
University of Lille, France.
PMID- 10676102
TI - [Guidelines: research in the web, critical assessment, clinical application].
PMID- 10676103
TI - [New trends in pharmacotherapy of arterial hypertension].
PMID- 10676104
TI - [Treatment of acute myocardial infarction: present and future].
PMID- 10676105
TI - [Educational status, social class indicators and diseases].
PMID- 10676106
TI - [Mechanism of action of quinapril in the treatment of primary arterial
hypertension].
AB - The effects of a long-term therapy with quinapril on plasma renin activity,
plasma aldosterone, atrial natriuretic peptide and left ventricular mass were
analysed in patients with mild to moderate systemic hypertension. Fifteen
patients (4 women) were treated for one year with quinapril 10 or 20 mg once
daily, reducing hereby the systolic and diastolic blood pressure from 167.5 +/-
11.3 to 141 +/- 6.7 mmHg p < 0.001 and from 105.3 +/- 5 to 90 +/- 7 mmHg
respectively, within the first two weeks. Blood pressure remained stable during
the following 52 weeks. After 6 and 52 weeks of therapy, as expected, we observed
an increase of plasma renin activity, plasma aldosterone decrease from 262.6 +/-
88.1 to 178.8 +/- 79.9 p = 0.01 and to 170.3 +/- 64.3 ng/ml p = 0.006
respectively. Atrial natriuretic peptide levels were not significantly altered.
After 52 weeks of treatment left ventricular mass index decreased from 107.9 +/-
16.2 to 90.1 +/- 13.4 g/m2 p = 0.0001. It is concluded that treatment with
quinapril for 1 year in addition to controlling blood pressure also reduced left
ventricular mass probably by a favourable effect on renin-angiotensin-aldosterone
system.
PMID- 10676107
TI - [Amiodarone pulmonary toxicity].
AB - The Authors discuss a case of amiodarone pulmonary toxicity, with simultaneous
alveolar and interstitial infiltrates, in a female patient 75 years old, who took
the drug for 6 months at a low dosage (200 mg/daily for 5 days a week). It is
outlined that the diagnosis can be achieved only by exclusion of other
aetiologies, since clinical and diagnostic features are not pathognomonic for
such disease. The withdrawal of the drug and the administration of the steroid
therapy determined a fast improvement of the clinical and radiological
appearance.
PMID- 10676108
TI - [Mycosis fungoides: a clinical case].
PMID- 10676109
TI - [Guidelines in internal medicine].
PMID- 10676110
TI - [Clinical diagnosis of infective endocarditis].
PMID- 10676111
TI - [Treatment of infective endocarditis].
PMID- 10676112
TI - [Endocarditis in valve prosthesis].
PMID- 10676113
TI - [Infective endocarditis in the elderly].
PMID- 10676114
TI - [Nephropathy: current aspects and therapeutic prospects].
PMID- 10676115
TI - [Cardiorenal physiopathology and heart failure: current aspects and therapeutic
prospects].
AB - The heart and the kidney exert a reciprocal control of their function in order to
maintain a steady state of haemodynamics, both in physiological and pathological
conditions. The functional relationship between the two organs becomes
particularly evident during heart failure. The knowledge of such relationship may
play an important role in the management of heart failure. We also report here
our experience in the treatment of congestive heart failure with depletive
techniques vicarious of kidney function.
PMID- 10676116
TI - [The third scientific revolution].
PMID- 10676117
TI - [Health as a fundamental human right: the development of the World Health
Organization].
PMID- 10676118
TI - [Evolution of health systems].
PMID- 10676119
TI - [Peace, vaccine and potatoes (the decline of high mortality].
PMID- 10676120
TI - [Vaccination policies and the eradication of smallpox].
PMID- 10676121
TI - [Medicine and molecular biology: a happy marriage?].
PMID- 10676122
TI - [Medically-assisted reproduction].
PMID- 10676123
TI - [Neonatology: several history lessons].
PMID- 10676124
TI - [The arrival of organ transplantation].
PMID- 10676125
TI - [The major phases of medical imaging].
AB - In this article, we give an insight into the historic developments of radiology,
evoking some of the milestones which from the end of the 19th century to the
beginning of the third millennium have marked the way of one of the most rapidly
growing fields in medicine.
PMID- 10676126
TI - [Blood and transfusion].
PMID- 10676127
TI - [Emergence of infectious diseases].
PMID- 10676128
TI - [Turning points in psychology and psychiatry in the 20th century].
PMID- 10676129
TI - [Rational union between medical sociology and academics].
PMID- 10676131
TI - [The paradox of heads and tails].
PMID- 10676130
TI - [Medicine, bioethics, public health].
PMID- 10676132
TI - [The correspondence of Gottfried Brugger (1857-1891) or the tragic fate of a
young veterinarian].
PMID- 10676133
TI - [A student circle of friends: the portrait collection of the veterinarian
Gottfried Pfister (1836-1903)].
PMID- 10676134
TI - [Formation of veterinarians from Vaud in the 18th century].
PMID- 10676135
TI - [Guide dogs for the blind: aspects of a special human-animal relationship in
history and the present time].
PMID- 10676136
TI - [Memory advantage of performed actions: comments on multimodal memory theory].
AB - Based on the integration of the memory advantage for subject-performed actions
into the multimodal theory of episodic memory by J. Engelkamp (1997), three
issues referring to the so-called enactment effect are discussed and addressed by
statistical r-analyses. Firstly, the empirical basis of the functional
distinction between motor and non-motor memory resources by means of dual-task
experiments is questioned. Secondly, a multinomial modeling analysis is presented
which aims at the contributions of automatic and controlled memory processes to
the enactment effect in the process-dissociation paradigm. Finally, the effect of
enactment on memory for serial order information is discussed with respect to
recent accounts of serial memory.
PMID- 10676137
TI - [Selective interference, process dissociation and serial information in recall of
performed actions. A comment on Thorsten Meiser's remarks on the multimodal
memory theory].
AB - In this commentary, I deal with three questions. (1) Do the findings of
interference experiments justify the distinction between motor and visual
imaginal processes? (2) Can automatic and controlled process components be
identified by the process-dissociation technique? (3) Does encoding of order
information depend on encoding instructions?
PMID- 10676138
TI - [Effects of knowledge acquisition on verbal linearization about spatial
orientation].
AB - This paper deals with determinants of linearization in spatial communication. The
well-known linearization principles, such as the principle of natural order,
primarily emphasize features of the given information. We assume that verbal
linearization is in addition influenced by the speakers' knowledge acquisition.
Six experiments with a total of 272 participants are reported here. A particular
spatial constellation was presented to the participants, who were asked to talk
about it afterwards. The linearizations then produced were defined as dependent
variables. The results show that the linearizations were influenced by the
speaker's experience with the configuration (according-to-experience effect) and
also demonstrate the importance of the first encounter (anchor effect). Further
characteristics of the effects mentioned above are described and discussed
regarding memory research and psycho-linguistics.
PMID- 10676139
TI - [Parametric coupling in sequences of bimanual reversal movements with identical
and different amplitudes].
AB - In sequences of bimanual movements, the voluntary modulation of the amplitude of
the one hand (inducing hand) induces an involuntary modulation of the amplitude
of the other hand (dependent hand), the strength of which increases with
increasing tempo. By means of a task in which subjects perform sequences of two
short and two long reversal movements in alternation with the inducing hand, but
constant short or long reversal movements with the dependent hand, we addressed
two questions. The first question was concerned with differences in the effects
of tempo on the involuntary amplitude modulation of short and long movements; the
second question was whether the involuntary amplitude change fades away or is
propagated when bimanual movements with certain target amplitudes are repeated.
At low tempo the contralateral effect of voluntary amplitude changes on short
amplitude movements was stronger than the effect on long-amplitude movements, but
at high tempo this difference was reversed. This result is not consistent with
the assumption that contralateral amplitude modulation results from an overflow
of efferent commands, which increases with the force of the movement; however, it
is consistent with other findings on a transient coupling during amplitude
specification (parametric coupling). The involuntary amplitude change was
essentially propagated to the next movement in the sequence and did not fade
away. This finding suggests that the assimilation of amplitudes that can be
observed in bimanual sequences of movements with different, but for each hand
constant, amplitudes could result from an effect of transient parametric coupling
during the initial specification of amplitudes and need not necessarily be
attributed to cross-talk at the level of motor commands or efferent innervation.
PMID- 10676140
TI - [Recognize the victim in need: the effect of situational cues and priming on
identification of need for help].
AB - An experimental study investigated the joint influence of priming and situational
cues on the perceived neediness of a target. A scrambled sentence test was used
to prime two groups with the concepts of neediness and safety. In a third group a
neutral concept was activated. A free description of the target and a subsequent
adjective rating were applied as dependent measures. Although results indicated
that both factors affected the attribution of neediness on a free description,
the effects of priming were only apparent on this measurement and disappeared on
the second task.
PMID- 10676141
TI - [Posner's theory of attention: right hemisphere processing advantage in extended
attention].
AB - Posner proposed a theory of attention based on target detection, visual
orienting, and alertness. The latter is supposed to use brain structures mainly
located in the right hemisphere. Whitehead found a right hemisphere processing
superiority during sustained attention. An additional auditory stimulus is
thought to produce a change of alertness and should interfere with this
asymmetry, which Whitehead was able to show, too. It remains unclear how the left
hemisphere is activated by right hemisphere pathways. Therefore we tried to
replicate Whitehead's findings. In our first experiment the expected interaction
between visual field, foreperiod duration, and tone was obtained. Probably the
tone used in our experiment was not intense enough to produce a sufficient change
in alertness. We used a more intense tone in a second experiment. This time a
three-way interaction was present but could not be interpreted in terms of
Whitehead's assumptions. Instead, the additional alerting stimulus seems to
influence the state of alertness in a much more general and long-lasting way.
PMID- 10676142
TI - [Effects of dimensional and social comparisons on ability assessment and
satisfaction with performance].
AB - The study deals with the question whether internal dimensional comparisons
(comparisons of one's own achievement in a task with one's own achievement in
another task) contribute to the development of task-specific self-evaluations. In
an experimental study, N = 135 student subjects who had worked on two different
types of tasks received manipulated achievement feedback with reference to
dimensional and social comparisons. Results indicated the relevance of
dimensional comparison information. Subjects scored their own ability and
contentment with their result in the first type of task more positively
(negatively) when they had received a better (worse) result than in the second
task.
PMID- 10676143
TI - Epidemiology of feline leukaemia and feline immunodeficiency virus infections in
the Czech Republic.
AB - Commercial serological sets were used for the examination of 727 cats kept in
larger towns of the Czech Republic. FeLV antigen and antibodies to FIV were
demonstrated in 96 (13.2%) and 42 (5.8%) of the animals, respectively. Seven
(0.96%) animals were positive for both FeLV and FIV. Most of the FeLV and/or FIV
positive patients were intact rambling males aged 1-4 years. Chronic
gastrointestinal and respiratory diseases were found in 54.2% and 43.8% of the
FeLV-positive patients, respectively. Chronic urinary tract diseases and
generalized lymphadenopathy were found in 47.6% and 45.2% of the FIV-positive
patients, respectively. The results of this first survey in the Czech Republic
have shown prevalence values and clinical patterns similar to those reported
formerly from other European countries.
PMID- 10676144
TI - Prevalence and seasonal pattern of caprine trichostrongyles in a dry area of
central Spain.
AB - A total of 322 gastrointestinal tracts were examined from traditionally reared
goats originating from a dry area of central Spain. A large spectrum of
gastrointestinal nematodes was observed, Teladorsagia circumcincta and T.
trifurcata being the most prevalent species, followed by Trichostrongylus
vitrinus and Nematodirus filicollis. Trichostrongylus capricola recorded a high
level of infection despite low prevalence. A nematode infection rate of 93% and
an average burden of over 3000 worms indicates the highly prevalent infection in
Spanish goats. The seasonal pattern shows a real risk of infection all year
round, with two peaks in the summer and autumn. Females were more frequently
infected than males.
PMID- 10676145
TI - Aggregation of sow lactobacilli with diarrhoeagenic Escherichia coli.
AB - A total of 20 strains of lactobacilli were isolated from the oesophagus and
vagina of 20 sows at the time of partus. Aggregation activity was seen between
six homofermentative autoaggregative lactobacilli and three strains of pathogenic
Escherichia coli with F4, F5 and F6 fimbriae. The highest aggregation activity
was observed between vaginal Lactobacillus acidophilus PV 32 or oesophageal OE
2/1 and E. coli with F4 (K88). The presence of aggregation-promoting factor (APF)
was confirmed by polymerase chain reaction (PCR) with primers of a specific
fragment the apf gene derived from human L. gasseri 4B2 in one oesophageal L.
acidophilus strain OE 2/1. We propose that autoaggregative lactobacilli that
aggregate with diarrhoeagenic E. coli can express a class of APF proteins that
exhibit the function of an aggregation mediator.
PMID- 10676147
TI - Pathological and microbiological studies on pneumonic lungs from Danish calves.
AB - During 1 year, the association between microbiological and pathological findings
in 72 lungs from calves submitted to the Danish Veterinary Laboratory for
diagnostic purposes was studied. All cases were evaluated pathologically and
bacteriologically, whereas only 68 cases were examined for the presence of bovine
respiratory syncytial virus (BRSV), parainfluenza-3 virus (PI-3 virus) and bovine
coronavirus, 62 cases for bovine viral diarrhoea virus (BVD), 45 cases for bovine
adenovirus and 51 cases for mycoplasmas. Based on histopathological examination,
the cases were diagnosed as fibrinous and/or necrotizing bronchopneumonia,
suppurative bronchopneumonia, embolic pneumonia and others. The diagnoses were
based on the dominating and most severe lesions in each lung. Haemophilus somnus,
Pasteurella multocida, Actinomyces pyogenes, P. haemolytica and BRSV were the
most commonly found bacterial and viral lung pathogens, respectively. Pasteurella
spp. and H. somnus were often associated with the more severe fibrinonecrotizing
type of bronchopneumonia, whereas BRSV was primarily detected in cases of
suppurative bronchopneumonia. Mycoplasma bovis was isolated from one case only,
whereas M. dispar, M. bovirhinis and Ureaplasma diversum were present, often
concomitantly, in the majority of cases. Aspergillus fumigatus was isolated from
one case.
PMID- 10676146
TI - Pigeon paramyxovirus-1 (P-group) as the cause of severe outbreaks in fancy
Columba livia in Saudi Arabia.
AB - An avian paramyxovirus-1, which was previously isolated from ailing fancy Columba
livia in Saudi Arabia, was characterized in this study using monoclonal
antibodies (Mabs). The results indicate that although the virus belongs to the
pigeon paramyxovirus-1 (PPMV-1) group 'P' still it shows some variation in its
binding pattern to the Mabs.
PMID- 10676148
TI - Serum bile acids in captive bustards.
AB - Blood samples were collected from clinically normal male and female houbara
(Chlamydotis undulata macqueenii), kori (Ardeotis kori), buff-crested (Eupodotis
ruficrista gindiana) and white-bellied bustards (E. senegalensis) to determine
serum bile acid concentrations. Bile acid concentrations were determined by
analysis with an Ultrospec 3000 ultraviolet/visible spectrophotometer, using an
enzymatic bile acid test. The results provided values of serum bile acid
concentrations for the four species, with means +/- standard errors of 35.8 +/-
2.8 mumol; 51.1 +/- 5.0 mumol; 18.4 +/- 2.1 mumol and 20.8 +/- 5.4 mumol for the
houbara, kori, buff-crested and white-bellied bustard, respectively. Although no
gender or age differences were detected within species, the results demonstrated
significant differences in concentrations in clinically normal individuals
between the different species.
PMID- 10676149
TI - Coagulase-negative staphylococci and mammary gland infections in cows.
AB - Coagulase-negative staphylococci (CNS) are the most frequently isolated bacteria
from bovine mammary gland milk samples. The objective of this study was to
determine the type of inflammation evoked by CNS in the mammary gland of cows
during their first lactation. Twenty-four Israeli-Holstein heifers in their first
lactation were tested for bacteriological status, somatic cell count (SCC) and
differential leucocyte count in milk 60-120 days postparturition and every 50-60
days after until drying off. Following the first testing, the 96 quarters of the
24 heifers were classified as follows: 69.8% as no bacterial growth (NBG), 27.1%
infected with CNS and 3.1% infected with Staphylococcus aureus. During lactation,
84.5% quarters had no change in their classification, 6.2% were newly infected
with other pathogens, 3.1% were classified as self-cured and in 6.2% sporadic
bacteria were isolated. Among the CNS, S. intermedius, S. chromogenes and S.
haemolyticus were the most frequently isolated. Milk from CNS-infected quarters
had significantly higher SCC than milk from NBG quarters. An analysis of the
leucocyte pattern in milk from CNS vs. NBG quarters revealed a significant
increase in polymorphonuclears and a significant decrease in the percentage of
total lymphocytes and lymphocytes bearing CD4+ or CD8+. The high percentage of
CNS-infected quarters that remained unchanged in their bacterial status during
the first lactation, indicates that those CNS have the ability to elude the
immune system and persist in the mammary gland for a long time. The persisting
infection, resulting to some extent from an increase of SCC by some CNS strains,
suggests that in the near future control steps will have to be taken into
consideration, in order to enhance the improvement of milk quality.
PMID- 10676150
TI - Efficacy of an intranasal immunization with gEgC and gEgI double-deletion mutants
of Aujeszky's disease virus in maternally immune pigs and the effects of a
successive intramuscular booster with commercial vaccines.
AB - In this study, an intranasal immunization strategy was set up in maternally
immune pigs in order to protect them not only clinically but also virologically.
Two genetically engineered Aujeszky's disease virus (ADV) strains, Kaplan gE-gI-
and Kaplan gE-gC-, were used for intranasal immunization. Both strains were safe
for 4-week-old pigs. A single intranasal inoculation of 10(6.0) TCID50 of Kaplan
gE-gI- and Kaplan gE-gC- at 4 weeks of age in the presence of moderate titres of
maternally derived antibodies (SN titres: 12-16) reduced the amount of weight
loss, fever and virus excretion upon challenge 6 weeks later. In a second
experiment, the effect of an additional intramuscular booster with three
different commercial vaccines (containing attenuated Bartha or NIA3-783 or
inactivated Phylaxia; all suspended in an oil-in-water emulsion) at 10 weeks of
age was evaluated. One month after the last intramuscular booster, between five
and seven pigs from each group were selected for challenge. All
intranasally/intramuscularly immunized pigs showed a significantly better
clinical and virological protection after challenge than the single intranasally
immunized pigs. In the double immunized group, the protection was better when
Kaplan gE-gC- was used for the intranasal priming (only two of 14 pigs excreted
virus with a duration of 4 days) than when Kaplan gE-gI- was used (13 of 18 pigs
excreted virus with a duration ranging from 1 to 4 days). The virological
protection was not influenced by the type of vaccine used for booster
vaccination. Because the intranasal/intramuscular immunization approach is very
compatible with current pig movements on farms and pigs with moderate levels of
maternally derived antibodies can effectively be immunized, it can be considered
as a good alternative to intramuscular/intramuscular vaccinations especially in
regions with a high ADV prevalence.
PMID- 10676151
TI - Isolation and further characterization of phase variants of Streptococcus equi
subsp. zooepidemicus.
AB - In the present study the soft agar technique was used to isolate phase variants
of S. equi subsp. zooepidemicus-cultures isolated from infections of horses. The
phase variants were characterized by a compact or diffuse colony morphology in
this media. The variants could be cultivated separately and further characterized
genotypically by RAPD analysis and by macrorestriction analysis of their
chromosomal DNA by pulsed-field gel electrophoresis, indicating the identity of
both strains of each pair. The diffuse colony variants grew uniformly turbid
after cultivation in fluid media, did not haemagglutinate rabbit erythrocytes,
and displayed a reduced surface hydrophobicity in hexadecane and phenyl-sepharose
adherence tests. The compact colony variants generally grew as sediment with
clear supernatant in fluid media, haemagglutinated rabbit erythrocytes and showed
an enhanced surface hydrophobicity in both hydrophobicity tests. The presented
soft agar technique allowed a demonstration of phase variation of S. equi subsp.
zooepidemicus and a subsequent isolation of the variants. This might be an
important prerequisite to understanding the pathogenic importance of phase
variation among isolates of this bacterial species.
PMID- 10676152
TI - Antibody against Testudo herpesvirus is not common in Chinese soft-shelled
turtles.
AB - Seventy-six serum samples of Chinese soft-shelled turtles (Trionyx sinensis) were
collected at Jiangsu Province, China. The neutralization test (NT) was performed
with the sera, Testudo herpesvirus (THV) and turtle heart cells (THC).
Neutralizing antibodies were detected in five of 76 samples and the titres were
1:10-1:20. Having optimized the conditions, the dot-enzyme-linked immunosorbent
assay (Dot-ELISA) was developed and eight serum samples exhibited positive
results. Five samples were positive by both NT and Dot-ELISA. The percentage of
positive samples was only 6.6% (NT) and 11% (ELISA). It is suggested that THV
infection is not a serious problem for the Chinese soft-shelled turtle culture in
this region.
PMID- 10676153
TI - Bovine herpesvirus 1 (BHV1) seroprevalence in the breeding cattle population of
the Veneto region: prospects for the implementation of a control programme.
AB - The results of a serological survey for bovine herpes virus (BHV1) antibodies in
the breeding cattle population of the Veneto region are presented. The data do
not support the hypothesis of an high prevalence of BHV1; on farms where
vaccination was not carried out most animals were seronegative, and seropositive
animals were generally older. Therefore, when drawing up the guidelines for a
control programme, systematic immunization (with glycoprotein E-deleted vaccines)
should be restricted only to farms with a high prevalence of BHV1 antibodies
and/or with a high risk of BHV1 occurrence; in most unvaccinated farms a 'test
and removal' policy appears to be more appropriate in order to rapidly eradicate
BHV1 from the entire stock.
PMID- 10676154
TI - Mastitis caused by Mycoplasma mycoides subspecies mycoides (large colony type) in
goat flocks in Spain.
AB - We describe three different outbreaks of mastitis caused by M. mycoides
subspecies mycoides LC type (Mmm LC) in three goat flocks from the Extremadura
Region of south-west Spain. Thirty-two fast-growing isolates were obtained on
Hayflick's and Friis's media with inhibitors from different specimens. All were
identified as Mmm LC in spite of their cultural, biochemical and serological
features.
PMID- 10676177
TI - A strategy for visioning the future for medical education.
PMID- 10676178
TI - Community primary care preceptors: does practice site or specialty make a
difference?
PMID- 10676179
TI - Health professionals' experiences with continuing and distance education.
PMID- 10676180
TI - A partnership model for a health professions student pipeline.
PMID- 10676181
TI - Changing the culture of "unmatch day".
PMID- 10676182
TI - A pre-baccalaureate course on becoming a health professional.
PMID- 10676183
TI - Using medical students in a translation service for the hospital.
PMID- 10676184
TI - Application of a web-based instruction for a clinical course.
PMID- 10676185
TI - A multimedia CD-ROM tool to improve residents' cardiac auscultation skills.
PMID- 10676186
TI - The collaborative pediatrics self-study site for on-line self-assessment for
medical students.
PMID- 10676187
TI - Teaching medical information retrieval skills to internal medicine residents at
the terminal-side.
PMID- 10676188
TI - Computer-administered formative quizzes in a basic science course.
PMID- 10676189
TI - A collaborative virtual medicine library.
PMID- 10676190
TI - Using laptop computers for teaching and evaluation in an extended community
preceptorship.
PMID- 10676191
TI - Using WWW-based instruction modules and E-mail for a remote neurology course.
PMID- 10676192
TI - Promoting reflective teaching with personal digital assistants.
PMID- 10676193
TI - Web-based instruction to enhance the clinical teaching of community preceptors.
PMID- 10676194
TI - Curriculum of literature and medicine for residents.
PMID- 10676195
TI - A public-private collaboration to develop medical students' communication skills
with patients.
PMID- 10676196
TI - A new relationship module for doctor-patient encounters.
PMID- 10676197
TI - Using patient narrative videos for understanding better the illness experience.
PMID- 10676198
TI - Using standardized patients to teach end-of-life skills to clinical clerks.
PMID- 10676199
TI - Teaching professionalism in medical grand rounds.
PMID- 10676200
TI - Incorporating discussion of cultural diversity throughout the first-year medical
curriculum.
PMID- 10676201
TI - A comprehensive student peer-teaching program.
PMID- 10676202
TI - Recruiting and following adolescent standardized patients.
PMID- 10676203
TI - A four-year longitudinal gerontology curriculum for medical students.
PMID- 10676204
TI - A critical care subinternship using the ICU as an applied physiology laboratory.
PMID- 10676205
TI - Improving gross anatomy education by using surgery residents as co-teachers.
PMID- 10676206
TI - A partnership in interdisciplinary clinical education.
PMID- 10676207
TI - Reinvigorating PBL by integrating standardized-patient interviews.
PMID- 10676208
TI - Implementing national guidelines for the internal medicine clerkship: an
ambulatory case workbook.
PMID- 10676209
TI - A diabetes self-care simulation for residents and medical students.
PMID- 10676210
TI - Massachusetts Medical Society Seminar Series on Domestic Violence.
PMID- 10676211
TI - An interactive, problem-based workshop on breastfeeding.
PMID- 10676212
TI - Integrated clerkships for medical undergraduates.
PMID- 10676213
TI - A clinical integration course.
PMID- 10676214
TI - A geriatric medicine program in the internal medicine clerkship.
PMID- 10676215
TI - A women's health course for education in internal medicine.
PMID- 10676216
TI - The interdisciplinary case conference.
PMID- 10676217
TI - Using respiratory therapists to teach arterial puncture for blood gas procedures
to third-year medical students.
PMID- 10676218
TI - The standardized family: a cross-institutional effort to standardize the
ambulatory clerkship experience.
PMID- 10676219
TI - Teaching medical documentation according to the HCFA guidelines.
PMID- 10676220
TI - A tool to evaluate self-efficacy in evidence-based medicine.
PMID- 10676221
TI - Comprehensive performance examination gives insights into the "hidden
curriculum".
PMID- 10676222
TI - Using telemedicine and standardized patients to evaluate off-campus students'
skills.
PMID- 10676223
TI - The brief structured observation--a tool for focused feedback.
PMID- 10676224
TI - A first-year course focused on the patient, the physician, and the community.
PMID- 10676225
TI - A longitudinal community clinical program for first-year medical students.
PMID- 10676226
TI - A science learning initiative with urban junior high school students.
PMID- 10676227
TI - Introducing home visits and interdisciplinary learning to an existing geriatrics
practicum for medical students.
PMID- 10676228
TI - Managed-care curriculum for family practice residents.
PMID- 10676229
TI - Teaching managed-care principles to residents.
PMID- 10676230
TI - A managed care curriculum implemented across four academic departments using
mandated evaluation instruments.
PMID- 10676231
TI - Scheduling solutions for the service-education conflict in internal medicine
residency programs.
PMID- 10676232
TI - A separate-sample pretest-post-test design to evaluate a practice-management
seminar for residents.
PMID- 10676233
TI - Training in behavioral medicine and behavioral change for family practice
residents.
PMID- 10676235
TI - A curriculum for pediatrics residents in development and evaluation of clinical
practice guidelines.
PMID- 10676234
TI - A new approach to the journal club.
PMID- 10676236
TI - Medical education 101--a faculty development course.
PMID- 10676237
TI - Development of a leadership-skills--assessment instrument for medical educators.
PMID- 10676238
TI - A faculty development program in basic teaching skills.
PMID- 10676239
TI - Faculty development using evidence-based medicine as an organizing curricular
theme.
PMID- 10676240
TI - Auscultation CME at the bedside for pediatrics practitioners.
PMID- 10676241
TI - Improving communication in the referral-consultation process.
PMID- 10676242
TI - Training opinion leaders to improve physician practice in the management of
dyslipidemia.
PMID- 10676243
TI - A curriculum for producing resident researchers.
PMID- 10676244
TI - A four-month faculty development curriculum on teaching and learning.
PMID- 10676245
TI - Using distance education for an MPH degree program in health services
administration for physicians.
PMID- 10676246
TI - Building administrative skills: a framework for junior faculty.
PMID- 10676247
TI - Focus groups on curriculum and program evaluation.
PMID- 10676248
TI - Center for Medical Education Research.
PMID- 10676249
TI - Fourth-year students as teachers of the physical examination.
PMID- 10676250
TI - Medical students as co-instructors in an introductory clinical medicine course.
PMID- 10676251
TI - Faculty mentors for interaction over four years.
PMID- 10676252
TI - A computer literacy requirement for medical students.
PMID- 10676253
TI - Virtual PBL: full-scale human simulation technology.
PMID- 10676254
TI - A multimedia and Internet program to present clinical cases.
PMID- 10676255
TI - New sources for accessing and interpreting electronic information.
PMID- 10676256
TI - Medical education over the Internet.
PMID- 10676257
TI - Using computer technology for nutrition education and cancer prevention.
PMID- 10676258
TI - A simulator-based respiratory physiology workshop.
PMID- 10676259
TI - Combining service and learning in partnership with communities.
PMID- 10676260
TI - A structured diary to promote reflection and active learning.
PMID- 10676261
TI - Electronic learning contracts.
PMID- 10676262
TI - Clinical instruction for delivering bad news.
PMID- 10676263
TI - Introducing students to the spiritual dimension of illness.
PMID- 10676264
TI - A student-run course in the medical humanities.
PMID- 10676265
TI - A curriculum in medical record documentation.
PMID- 10676266
TI - Addressing telephone medicine in the medical school curriculum.
PMID- 10676267
TI - Health Policy Fellowship Programs.
PMID- 10676268
TI - An educational conference to recruit women to primary care residencies.
PMID- 10676269
TI - An experiential approach to alternative medicine.
PMID- 10676270
TI - Breastfeeding demonstration in behavioral science curriculum.
PMID- 10676271
TI - Integration of developmental psychology and preventive medicine.
PMID- 10676272
TI - Linking basic, clinical, and social sciences.
PMID- 10676273
TI - Total immersion for medical neuroscience.
PMID- 10676274
TI - A generalist continuity experience in the community.
PMID- 10676275
TI - Replacing lectures with reading, small-group discussion, and computer-assisted
learning.
PMID- 10676276
TI - Maximizing student-centered learning.
PMID- 10676277
TI - GeriAction: a preclinical bedside course.
PMID- 10676278
TI - The paper-case clinic: teaching medical physiology by PBL.
PMID- 10676279
TI - Computer-based learning in PBL.
PMID- 10676280
TI - A course in advanced clinical pharmacology and anesthesiology.
PMID- 10676281
TI - Teaching occupational history-taking.
PMID- 10676282
TI - Branching cases in problem-based learning.
PMID- 10676283
TI - Using problem-based learning to target public health problems.
PMID- 10676284
TI - Integrating women's health issues into the first-year curriculum.
PMID- 10676285
TI - A multidisciplinary approach to a women's health curriculum.
PMID- 10676286
TI - Implementation of a foundations in medicine course.
PMID- 10676287
TI - The Vermont Generalist Curriculum.
PMID- 10676288
TI - Longitudinal clinics for medical students.
PMID- 10676289
TI - A palliative care clerkship for senior medical students.
PMID- 10676290
TI - An interdisciplinary course on domestic and family violence.
PMID- 10676291
TI - An evidence-based medicine seminar series.
PMID- 10676292
TI - Teaching medical students about long-term illness.
PMID- 10676293
TI - "Virtual delivery": an interactive role play of abnormal labor.
PMID- 10676294
TI - Criterion-based evaluation in a third-year internal medicine clerkship.
PMID- 10676295
TI - Group evaluation of student performance in a clerkship.
PMID- 10676296
TI - Critique of a clinical curriculum from examination performance.
PMID- 10676297
TI - An independent community-based ambulatory clerkship.
PMID- 10676298
TI - A comprehensive multidisciplinary ambulatory clerkship.
PMID- 10676299
TI - Development of a multidisciplinary ambulatory clerkship.
PMID- 10676300
TI - Educating medical students in ambulatory clinics while maintaining patient flow.
PMID- 10676301
TI - Interdisciplinary primary care summer preceptorships.
PMID- 10676302
TI - Ethics curriculum for internal medicine residents.
PMID- 10676303
TI - Psychosocial curriculum for a primary care residency.
PMID- 10676304
TI - Psychiatric and psychosocial training for residents.
PMID- 10676305
TI - Physician-patient communication in ambulatory settings.
PMID- 10676306
TI - Joint training for residents and chaplain interns.
PMID- 10676307
TI - Developing evaluation and review skills.
PMID- 10676308
TI - A remedial course on interviewing skills.
PMID- 10676309
TI - An industry-based practicum for occupational medicine.
PMID- 10676310
TI - A rural model for GME.
PMID- 10676311
TI - The "office-based medical team" for residents.
PMID- 10676312
TI - Primary care training for ob-gyn practitioners.
PMID- 10676313
TI - Distance learning in basic science for residents.
PMID- 10676314
TI - A cost-effective program to give video/audiotape feedback.
PMID- 10676315
TI - The IPX: early assessment for interns.
PMID- 10676316
TI - On-going and college-wide faculty development.
PMID- 10676317
TI - Improving the publication rate of fellowship research projects.
PMID- 10676318
TI - Faculty development through distance-learning.
PMID- 10676319
TI - Faculty development for community primary care preceptors.
PMID- 10676320
TI - Global measure of teaching performance.
PMID- 10676321
TI - Automating portfolio documentation for faculty.
PMID- 10676322
TI - Building clinicians' teacher knowledge.
PMID- 10676323
TI - Strategies to increase the number and the quality of innovations in Medical
Education Grants (IMEGs).
PMID- 10676324
TI - The student perception survey: a tool for assessing medical school curricula.
PMID- 10676325
TI - Macro program evaluation: an approach to evaluating a generalist physician
initiative program.
PMID- 10676326
TI - Vital indicators of teaching and learning success (VITALS): stakeholders'
perceptions of a course-improvement system.
PMID- 10676327
TI - Student-run focus groups for the evaluation of pre-clinical courses.
PMID- 10676328
TI - An early-acceptance program for underrepresented minority or economically
disadvantaged students.
PMID- 10676329
TI - An earlier approach to increase awareness of primary care careers.
PMID- 10676330
TI - A psychiatry club as an extracurricular activity for medical students.
PMID- 10676331
TI - A case-based integrated curriculum on the World Wide Web.
PMID- 10676332
TI - Computer case simulations for student evaluation in a PBL track.
PMID- 10676333
TI - LabSim: the western blot--a computer-based learning module.
PMID- 10676334
TI - An Internet home page to log students' patient contacts.
PMID- 10676335
TI - Clerkship evaluation by students: a standardized electronic mechanism.
PMID- 10676336
TI - A Web-based evaluation system.
PMID- 10676337
TI - Integrating basic science, clinical medicine, and applied research in an
ambulatory clerkship.
PMID- 10676338
TI - Teaching nutritional concepts by integrating basic science and introductory
clinical courses.
PMID- 10676339
TI - Using interdisciplinary educational strategies to improve the teaching of
cellular neurodevelopment.
PMID- 10676340
TI - Learning about the environment and health: an interclerkship experience for third
year students.
PMID- 10676341
TI - Integrating women's health issues into third-year medical and surgical curricula.
PMID- 10676342
TI - An interclerkship course on domestic abuse.
PMID- 10676343
TI - An integrated psychiatry-neurology clerkship within a problem-based learning
curriculum.
PMID- 10676344
TI - Integrating basic and clinical sciences in a course for senior medical and
graduate students.
PMID- 10676345
TI - The primary care continuum: basic science and clinical science integration in a
classroom setting.
PMID- 10676346
TI - Committing medical students to the ethics of medicine.
PMID- 10676347
TI - Introducing and assessing bioethical training in an internal medicine clerkship.
PMID- 10676348
TI - Integrating clinical ethical concepts and patient-centered problem solving into
the basic science curriculum.
PMID- 10676349
TI - A program to elucidate differences in medical students' communication skills.
PMID- 10676350
TI - Incorporating multiculturalism into a doctor-patient course.
PMID- 10676351
TI - Sequential assessment of medical student competence with respect to professional
attitudes, values, and ethics. Subcommittee on Professional Attitudes and Values,
Student Progress Assessment.
PMID- 10676352
TI - A multi-modal assessment of behavioral competence.
PMID- 10676353
TI - Teaching the sexual history: a tutorial approach.
PMID- 10676354
TI - Teaching the development of children's concepts of illness.
PMID- 10676355
TI - An extended evidence-based medicine curriculum for medical students.
PMID- 10676356
TI - A medical technology assessment course.
PMID- 10676357
TI - A preclinical practice skills program.
PMID- 10676358
TI - Medical interviewing in Spanish.
PMID- 10676359
TI - A family- and community-centered clinical curriculum.
PMID- 10676360
TI - Comprehensive evaluation of an academic-community partnership program.
PMID- 10676361
TI - A community-skills program in a preclinical curriculum.
PMID- 10676362
TI - Shaping the third year of a primary care program in a tertiary care environment.
PMID- 10676363
TI - A public health sub-curriculum of a pediatrics clerkship.
PMID- 10676364
TI - Introducing students to issues of socioeconomic status and community services.
PMID- 10676365
TI - Enhanced skill building.
PMID- 10676366
TI - Medical student education: an admission and curricular approach to rural
physician shortages.
PMID- 10676367
TI - A year-long longitudinal third-year clerkship in an inner-city health center
designed to maximize continuity.
PMID- 10676368
TI - Introduction to health: a new discipline for the early exposure of medical
students to public-health-related activities in Brazil.
PMID- 10676369
TI - A teaching tool to enhance medical student education in ambulatory internal
medicine.
PMID- 10676370
TI - Using two-way interactive televideo for problem-based tutorials in a family
medicine clerkship.
PMID- 10676371
TI - Using standardized-patient instructors to teach students about the needs of
patients with disabilities.
PMID- 10676372
TI - Cardiovascular risk factor identification: an educational experience for third
year medical students.
PMID- 10676373
TI - Removing rater effects from medical clerkship evaluations.
PMID- 10676374
TI - An alternative to clinical practice examinations.
PMID- 10676375
TI - Improving feedback with a clinical encounter form.
PMID- 10676376
TI - Hidden assets: incorporating the department business manager into training.
PMID- 10676377
TI - A practice-management experience in rural practice.
PMID- 10676378
TI - Practice-management curriculum for family practice residents.
PMID- 10676379
TI - Teaching residents in an ambulatory setting: introducing the concepts of managed
care in a fee-for-service clinic.
PMID- 10676380
TI - Training in community service and public health for internal medicine residents.
PMID- 10676381
TI - A comprehensive community-based program for training internal medicine residents
in ambulatory settings.
PMID- 10676382
TI - A nursing home experience for internal medicine residents.
PMID- 10676383
TI - A graduate medical experience in interdisciplinary group learning.
PMID- 10676384
TI - Incorporating internal medicine residents into an interdisciplinary geriatric
assessment team.
PMID- 10676385
TI - Expanding the pediatrics residency curriculum.
PMID- 10676386
TI - A sports medicine curriculum for pediatrics residents.
PMID- 10676387
TI - Development of a breastfeeding curriculum.
PMID- 10676388
TI - An instructional module in musculoskeletal examination for residents
incorporating physical therapists as patient-instructors and evaluators.
PMID- 10676389
TI - Using simulated students to improve residents' teaching.
PMID- 10676390
TI - Evaluating an evidence-based medicine curriculum.
PMID- 10676391
TI - Facilitated behavior-based evaluation of resident performances on an inpatient
rotation.
PMID- 10676392
TI - Analyzing the questions of physicians participating in CME programs.
PMID- 10676393
TI - An integrated approach to CME and service needs identification, program
development, and information diffusion.
PMID- 10676394
TI - Evaluating continuing competence of physicians through multiple assessment
modalities: the Physicians' Continued Competence Assessment Program (PCCAP).
PMID- 10676395
TI - An examination of the feasibility of developing and offering courses that meet
MAINPRO-C requirements.
PMID- 10676396
TI - Scholars for teaching excellence: institutionalizing faculty development.
PMID- 10676397
TI - A systems-based approach to improving educational quality via community-oriented
faculty development.
PMID- 10676398
TI - Improving written narrative assessments in small-group, problem-based tutorials:
continuous quality assurance and faculty development through peer review.
PMID- 10676399
TI - Enhancing awareness of diversity and cultural competence: a workshop series for
department chairs and course directors.
PMID- 10676400
TI - A situational approach to improve clinical teaching.
PMID- 10676401
TI - A workshop to improve faculty members' administrative skills.
PMID- 10676402
TI - A multidisciplinary experiential course in instructional methodology for academic
clinicians.
PMID- 10676403
TI - An evidence-based education journal club.
PMID- 10676404
TI - Building faculty skills as educators: a total quality management approach.
PMID- 10676405
TI - Risk assessment for children and other sensitive populations.
AB - Children form a unique subgroup within the population who require special
consideration in risk assessment. Children are not little adults. Their tissues
and organs grow rapidly, developing and differentiating. These development
processes create windows of great vulnerability to environmental toxicants.
Furthermore, the exposure patterns of children to environmental chemicals are
very different from those of adults. Traditional risk assessment has generally
failed to consider the special exposures and the unique susceptibilities of
infants and children. Adoption of a new child-centered agenda for research and
risk assessment is necessary if disease in children of toxic environmental origin
is to be identified, understood, controlled, and prevented. This agenda needs to
be multidisciplinary. Specific requirements within the agenda include: (1)
exploration and quantification of unique patterns of exposure for children; (2)
adoption of new, more sensitive approaches to testing chemicals that can
recognize the consequences of exposure during early development; (3)
identification, through clinical and epidemiologic studies, of etiologic
associations between environmental exposures and pediatric diseases; and (4)
elucidation, at the cellular and molecular levels, of the pathogenetic mechanisms
of pediatric environmental illness. In the United States, an important start
toward adoption of this new agenda has occurred since passage of the Food Quality
Protection Act in 1996. A Presidential Executive Order on Children's Health and
the Environment has been promulgated. This Order requires all federal agencies to
make protecting the health of children against environmental hazards a high
priority. A new Office of Children's Health Protection has been established at
the U.S. Environmental Protection Agency. Programs in children's environmental
health have been created at the Centers for Disease Control and Prevention, the
Agency for Toxic Substances and Disease Registry, and the National Institute of
Environmental Health Sciences. A national network of eight new Children's
Environmental Health Research and Disease Prevention Centers has been formed.
These developments will enhance research on previously understudied issues in the
environmental health of children and will provide a scientific basis for child
centered risk assessment.
PMID- 10676406
TI - The scientific and methodological bases of experimental studies for detecting and
quantifying carcinogenic risks.
AB - This paper outlines the aims and potential scope of experimental research for
risk identification and assessment in industrial carcinogenesis (environmental
and occupational). It then reviews the basic, general, and specific requisites of
a rigorously scientific nature that are required to render experiments to be more
appropriate and better geared to the information they seek. A range of
experimental approaches to risk assessment are illustrated by results achieved in
the Cancer Research Centre of the Ramazzini Foundation (CRC/RF). The paper ends
with a call for closer relations and integration among experimental,
epidemiologic, and biostatistical studies.
PMID- 10676407
TI - A Bayesian approach to hazard identification. The case of electromagnetic fields
and cancer.
AB - This paper discusses certain issues related to uncertainty in hazard
identification. Research on the hypothesis that exposure to 50-60-Hz magnetic and
electric fields (EMF) increases the risk of cancer has been ongoing for two
decades. Epidemiological studies provide a somewhat consistent pattern indicating
an increased risk for childhood leukemia and adult chronic lymphatic leukemia and
possibly also for other leukemias and brain cancer. However, there is still no
good candidate for a mechanism. Epidemiological studies have throughout the two
decades been interpreted with great caution, and final evaluations as to
carcinogenicity have been deferred. The reason for this carefulness may be the
lack of knowledge about a plausible mechanism. The purpose of this paper is to
discuss the process of weighing epidemiological data, experimental data, and
other background information into a synthesis such that the evaluation can be
based on all data combined. A Bayesian approach to this weighing is discussed
along with some alternatives. The Bayesian approach provides a structure for the
pooling of evidence and points out where subjective judgments come into play.
PMID- 10676408
TI - Mega-experiments to identify and assess diffuse carcinogenic risks.
AB - Diffuse carcinogenic risks, that is, those of low potency involving large areas
of population and sometimes all mankind, pose a serious public health problem.
Controlling these risks might help to reduce the incidence of, and mortality
from, cancer. Because of their low expected carcinogenic potential, these risks
are difficult to expose or assess. Epidemiologic investigation is of limited use
in this field and yields its data too late to be useful. Experimental studies
offer the only possible approach for assessing such risks. To increase
experimental sensitivity and consistency of results, mega-experiments must be
designed. That is, experiments that use a large number of animals with a well
known basic tumorigram, that extend the exposure and the biophase for as long as
possible, that carefully observe the effects, and that are performed with
suitable standardized methods. In the last 15 years the Ramazzini Foundation, in
its Cancer Research Center at Bentivoglio, has conducted or planned five mega
experiments. Initial results indicate the great potential of these methods for
identifying and assessing diffuse risks.
PMID- 10676409
TI - Long-term chemical carcinogenesis bioassays predict human cancer hazards. Issues,
controversies, and uncertainties.
AB - Long-term carcinogenesis bioassays are the most valued and predictive means for
identifying potential carcinogenic hazards of various agents to humans. Agents
may be chemicals, chemical mixtures, multiple chemicals, combinations of
chemicals, residues and contaminants, commercial products and formulations, and
various exposure circumstances. Life-styles, dietary factors, and occupational
exposure circumstances are very difficult, but not totally impossible, to
evaluate experimentally. Historically, the first chemical bioassay took place in
the early part of this century: Yamagiwa and Ichikawa in 1915, showed that coal
tar applied experimentally to rabbit ears caused skin carcinomas. Since then,
nearly 1500-2000 bioassays of one sort or another have been carried out.
Importantly, however, some of these bioassays must be considered inadequate for
judging the absence of carcinogenicity, since there were various limitations on
the way they were performed: too few animals, too short a duration, too low
exposure concentrations, too limited pathology, as examples. Thus, each bioassay
must be critically evaluated, especially those reported to be negative, because
"false negatives" are certainly more hazardous to human health than are "false
positives". Likewise, one must be careful not to discount bioassay results simply
because a target organ in rodents may not have a direct counterpart in humans
(e.g., Zymbal glands), or because an organ site in rodents may not be a major
site of cancers in humans (e.g., mouse liver). The design and conduct of a
bioassay is not simple, however, and one must be fully aware of possible pitfalls
as well as viable and often necessary alternatives. Similarly, evaluating results
and interpreting findings must be approached with the utmost objectivity and
consistency. These and other select issues, controversies, and uncertainties
possibly encountered in long-term bioassays are covered in this paper. One fact
remains abundantly clear: for every known human carcinogen that has been tested
adequately in laboratory animals, the findings of carcinogenicity are concordant.
PMID- 10676410
TI - Uncertainty in biomonitoring and kinetic modeling.
AB - Uncertainty in exposure assessment and uncertainty in kinetic models of early
effects after exposure to a toxin are addressed in this paper. Sources of
uncertainty in the determination of exposure of workers in chemical industry
exposed to dioxins are exhibited and a simple kinetic model for biomonitor
measurements of the concentrations from occupational exposure is derived. Model
uncertainty, and uncertainty in the model parameters of physiologically-based
pharmacokinetic models (PBPK models) are addressed when these models are used to
estimate the effective dose in risk assessment. Uncertainty in the model
parameters originating from the use of different statistical analysis methods is
exhibited for Hill type nonlinear kinetics of enzyme induction mediated by a
toxin.
PMID- 10676411
TI - Using molecular epidemiology in assessing exposure for risk assessment.
AB - Quantitative estimation of health risks depends on exposure characterization, the
nature of the dose response relationships, and the toxicity of the agents
involved. The greatest uncertainties in risk assessment almost always arise from
sparse or inadequate exposure data, inadequate understanding of exposure
mechanisms, and insufficient understanding of the exposure-dose-response pathway.
Additional sources of uncertainty arise when mixed or multiple exposures are
implicated in the disease pathway, and as a result of variability in both
exposures and responses within and between individuals. Here we consider the role
of exposure assessment in the risk assessment process, the use of biological
markers or molecular epidemiology to contribute to improvements in exposure
assessment for risk assessment, and uncertainties associated with the use of
biological markers.
PMID- 10676412
TI - Kaplan-Meier tumor probability as a starting point for dose-response modeling
provides accurate lifetime risk estimates from rodent carcinogenicity studies.
AB - In rodent carcinogenicity studies the linearized multistage model for modelling
the dose-response for specific tumor incidence has limitations in accuracy. This
note provides an alternative basic method for analyzing the dose-response
relationship. It is based on an actuarial analysis of mortality and specific
tumor incidence. The survival and the Kaplan-Meier specific tumor probability are
fitted to a Weibull model, in which exposure level, exposure period, and
observation period are independent variables. The mortality from specific cancers
at a certain time is simulated by means of the product of survival and specific
tumor rate (derivative of Kaplan-Meier tumor probability) as function of exposure
level, exposure duration, and observation period, integrated over the observation
period. The model is demonstrated by means of fitting the mortality and tumor
incidence data from the second NTP mice study on butadiene to a Weibull model and
to the linear, so-called, one-hit model. It will be shown that, in the
experimental exposure range, the Weibull model is far superior to the one-hit
model and predicts the specific tumor incidence with a high accuracy over the
total dose range. The Kaplan-Meier probability model for a specific tumor is also
useful for regulatory risk estimation. It is proposed that to develop a specific
tumor a risk level of 1 in 1,000 over a lifetime is about equal to 5 in 10,000 at
50% survival of the population. The Kaplan-Meier probability may be estimated at
the time of 50% survival of the exposed population, which can be deduced from the
all mortality data. This estimation method provides meaningful data, using
exposure level, exposure duration, and observation period properly. The advantage
of the actuarial analysis method for interpreting rodent studies is that
allowance is made for competition between death causes, which is essential in
case of considerable difference in mortality and specific mortality between dose
groups. Integrating the product of survival and specific tumor rate is the proper
way to predict, comparatively, mortality and specific mortality in exposed and
unexposed rodent populations.
PMID- 10676413
TI - Uncertainty in estimating exposure using a toxicokinetic model. The example of
2,3,7,8-tetrachlorodibenzo-p-dioxin.
AB - This paper deals with sources of uncertainty in the use of a minimal
physiological toxicokinetic model to obtain dose estimates for a dose-response
analysis of cancer in an occupational cohort. Toxicokinetic models make it
possible to construct exposure parameters that are more closely related to the
individual dose than traditional measures of exposures to toxic agents. However,
the process introduces a wide array of sources of uncertainty. Selecting a model
structure to describe the kinetics of a toxic agent implies necessarily making
simplifications and assumptions that influence the range of applicability of the
model. Once a model has been selected, the value of certain model parameters
(constants) must be assigned, for example, from anthropometric data. The question
then arises of how sensitive the model predictions are to variations in the
values of these constants. Other model parameters, typically those describing the
kinetics of the agent, are next estimated from actual data. There may be
limitations in the data concerning, for example, sparseness (too few observations
per subject) or missing values. The methods used for parameter estimation carry
their own set of assumptions that need to be appropriate to the situation at
hand. In summary, the dioxin example is used to characterize the sources of
uncertainty at different levels, such as model structure, methods and data used
for parameter estimation, estimation of occupational exposure, and imputation of
missing values in exposure indices derived from the kinetic model.
PMID- 10676414
TI - Uncertainty in the relation between exposure to magnetic fields and brain cancer
due to assessment and assignment of exposure and analytical methods in dose
response modeling.
AB - Incomplete scientific knowledge ensures that, in every study, uncertainty will
enter the processes of exposure estimation and exposure-response modeling. In the
light of the heated debate about the health effects of magnetic fields resulting
from power production and usage, we undertook a sensitivity analysis to evaluate
uncertainty related to key decisions in a previous study of brain cancer and
occupational exposure to magnetic fields. The findings appeared to be relatively
insensitive to most variations in the methods of exposure assessment, exposure
assignment, and data analysis. The results can be visualized by defining bands of
uncertainty about a best-bet estimate of the association based on our original
study. These bands of methodological uncertainties were similar in magnitude to
the conventional 95% confidence interval, but they provide a measure of the
potential range of systematic bias in the results, rather than reflecting
statistical variability alone. The methodology employed here can be applied to
other studies, and other researchers are encouraged to conduct sensitivity
analysis in order to estimate methodological uncertainty as an alternative to
statistical confidence intervals.
PMID- 10676415
TI - Measures of exposure to environmental tobacco smoke. Validity, precision, and
relevance.
AB - It is often not clear what the best measures of exposure are for a risk
assessment, or even how one should answer this question. Environmental tobacco
smoke (ETS) provides a good example for an exploration of uncertainty. There are
a variety of methods for estimating exposure and each has short-comings. In this
paper we summarize the physical characteristics of ETS and the principal methods
for assessing exposure. We review the accuracy and applicability of these
methods, and explore major sources of uncertainty in the assessment of ETS.
PMID- 10676416
TI - The contribution of environmental monitoring in the epidemiological assessment of
exogenous risk. The experience of ARPA in the Emilia-Romagna Region of Italy.
AB - The aim of the Emilia Romagna-Region Agency for Prevention and Environment (ARPA)
is to define and improve interactions among the various prevention departments of
the Emilia-Romagna Local Health Authorities in order to attain better knowledge
about the health status of the population by using epidemiology and etiology
studies, as well as predictive models. This is the basis for the environmental
health risk assessment strategy of ARPA. The priority activity areas for ARPA
are: urban areas, environmental and health effects of traffic (atmospheric
pollution and noise pollution); industrial areas (Ravenna chemical plants,
Modena/Reggio-Emilia ceramic factories and Ferrara chemical plants); high-speed
trains; pesticides; asbestos; and pollution of the Adriatic Sea.
PMID- 10676417
TI - Combining uncertainty factors in deriving human exposure levels of
noncarcinogenic toxicants.
AB - Acceptable levels of human exposure to noncarcinogenic toxicants in environmental
and occupational settings generally are derived by reducing experimental no
observed-adverse-effect levels (NOAELs) or benchmark doses (BDs) by a product of
uncertainty factors (Barnes and Dourson, Ref. 1). These factors are presumed to
ensure safety by accounting for uncertainty in dose extrapolation, uncertainty in
duration extrapolation, differential sensitivity between humans and animals, and
differential sensitivity among humans. The common default value for each
uncertainty factor is 10. This paper shows how estimates of means and standard
deviations of the approximately log-normal distributions of individual
uncertainty factors can be used to estimate percentiles of the distribution of
the product of uncertainty factors. An appropriately selected upper percentile,
for example, 95th or 99th, of the distribution of the product can be used as a
combined uncertainty factor to replace the conventional product of default
factors.
PMID- 10676418
TI - Statistical methods for developmental toxicity. Analysis of clustered
multivariate binary data.
AB - This paper discusses some of the statistical issues that arise from developmental
toxicity studies, wherein pregnant mice are exposed to chemicals in order to
assess possible adverse effects on developing fetuses. We begin with a review of
some current approaches to risk assessment, based on NOAELs, and provide
justification for the use of methods based on dose-response models. Due to the
hierarchical nature of the data, such models are more complicated in the present
context than, say, in cancer studies. For example, multivariate binary outcomes
arise when each fetus in a litter is assessed for the presence of malformations
and/or low birth weight. We describe a multivariate exponential family model that
works well for these data and that is flexible in terms of allowing response
rates to depend on cluster side. Maximum likelihood estimation of model
parameters and the construction of score tests for dose effect are briefly
discussed. Results are illustrated with data from several NTP studies.
PMID- 10676419
TI - Sources of uncertainty in dose-response modeling of epidemiological data for
cancer risk assessment.
AB - Epidemiologic data is increasingly being used for dose-response analysis in risk
assessment. The Environmental Protection Agency (EPA) and other U.S. agencies
have expressed a preference for using epidemiologic data rather than toxicologic
data when possible. However, there are a number of important sources of
uncertainty in using epidemiologic data for this purpose that need to be clearly
recognized and, when possible, quantified. This paper presents a critical review
of the major sources of uncertainty in the use of epidemiologic data for cancer
risk assessment. These may include: (1) study design issues such as potential
confounding and other biases, inadequate sample size, and followup, (2) the
choice of the data set, (3) specification of the dose-response model, (4)
estimation of exposure and dose, and (5) unrecognized variability in
susceptibility. Examples from risk assessments for cadmium, asbestos, and diesel
exhaust are used to illustrate the potential magnitude of some of these sources
of uncertainty. It is shown that the overall uncertainty from these various
sources combined may often result in highly uncertain risk estimates from dose
response modeling of epidemiologic data. For this reason, we believe it is best
to present a range of possible risk estimates, which, to the extent possible,
reflects the variability and uncertainty inherent in the dose-response evaluation
of epidemiologic data.
PMID- 10676420
TI - Nonparametric analysis of dose-response relationships.
AB - A nonparametric method, isotonic regression, is proposed for analyzing a dose
response relationship and for assessing a threshold value. There are several
advantages of this method compared to parametric models. No specific form of the
relationship (type of model and use of the covariates) is required. The only
assumption is monotonicity. Rejection of specific hypothesis can be based on the
result of a permutation test. Several applications (para-aramid, crystalline
silica, and PNOC) are presented. In these examples the dose-response
relationships are analyzed. Where a relationship is present the existence of a
threshold is investigated.
PMID- 10676421
TI - Estimates of the proportions of carcinogens and anticarcinogens in bioassays
conducted by the U.S. National Toxicology Program. Application of a new meta
analytic approach.
AB - A meta-analysis was performed in order to estimate the proportion of liver
carcinogens, the proportion of chemicals carcinogenic at any site, and the
corresponding proportion of anticarcinogens among chemicals tested in 397 long
term cancer bioassays conducted by the U.S. National Toxicology Program (NTP).
Although the estimator used was negatively biased, the study provided persuasive
evidence for a larger proportion of liver carcinogens (0.43, 90% CI: 0.35, 0.51)
than was identified by the NTP (0.28). A larger proportion of chemicals
carcinogenic at any site was also estimated (0.59, 90% CI: 0.49, 0.69) than was
identified by the NTP (0.51), although this excess was not statistically
significant. A larger proportion of anticarcinogens (0.66) was estimated than
carcinogens (0.59). Despite the negative bias, it was estimated that 85% of the
chemicals were either carcinogenic or anticarcinogenic at some site in some sex
species group. This suggests that most chemicals tested at high enough doses will
cause some sort of perturbation in tumor rates.
PMID- 10676422
TI - Characterization of uncertainty and variability in residential radon cancer
risks.
AB - Radon, a naturally occurring gas found at some level in most homes, is an
established risk factor for human lung cancer. The U.S. National Research Council
has recently completed a comprehensive evaluation of the health risks of
residential exposure to radon and developed models for projecting radon lung
cancer risks to the general population. This analysis suggests that radon may
play a role in the etiology of 10-15% of all lung cancer cases in the United
States, although these estimates are subject to considerable uncertainty. In this
article, we present a detailed analysis of uncertainty and variability in
estimates of lung cancer risk due to residential exposure to radon. We use a
general framework for the analysis of uncertainty and variability that we
developed previously. Specifically, we focus on estimates of the age-specific
excess relative risk (ERR) and lifetime relative risk (LRR), both of which vary
substantially among individuals. We also consider estimates of the population
attributable risk (PAR), which reflects the proportion of the lung cancer burden
attributable to radon. Variability in the ERR and LRR is largely determined by
variability in residential exposure levels and in the dosimetric K-factor used to
extrapolate from occupational to environmental settings. Uncertainty in the ERR
and LRR is due to uncertainty in the model parameters, notably those reflecting
the carcinogenic potency of radon and the modifying effect of attained age.
Uncertainty in the PAR is determined by uncertainty about the values of the
parameters in the risk models used to estimate the PAR. Uncertainty in radon
levels in homes and the dosimetric K-factor contribute comparatively little to
uncertainty in the PAR. These results suggest that reduction in uncertainty about
the PAR for radon induced lung cancer can only be achieved if more reliable risk
projection models can be developed.
PMID- 10676423
TI - Risk assessment--the mother of all uncertainties. Disciplinary perspectives on
uncertainty in risk assessment.
AB - Uncertainty in the detection and evaluation of chemical hazards to health leads
to challenges when conducting risk assessments. Some of the uncertainty has to do
with data, some with incomplete understanding of processes, and some with the
most fundamental ways of viewing the questions. True variability--across space,
in time, or among individuals--complicates the search for understanding many
important aspects of risk. A few statistical and toxicologic tools are available
to assess uncertainty. Three methods of classifying uncertainty are briefly
discussed. In addition, our disciplinary background may influence how we view and
discuss variability and uncertainty. We rarely know as much as we think we do
(and not just in risk assessment). Great uncertainty is likely to remain an
important part of risk assessment for some decades to come.
PMID- 10676424
TI - Distributions of individual susceptibility among humans for toxic effects. How
much protection does the traditional tenfold factor provide for what fraction of
which kinds of chemicals and effects?
AB - A significant data base has been assembled on human variability in parameters
representing a series of steps in the pathway from external exposure to the
production of biological responses: contact rate (e.g., breathing rates/body
weight, fish consumption/body weight); uptake or absorption (mg/kg)/intake or
contact rate; general systemic availability net of first pass elimination and
dilution; systemic elimination or half-life; active site availability/general
systemic availability; physiological parameter change/active site availability;
functional reserve capacity--change in baseline physiological parameter needed to
pass a criterion of abnormal function or exhibit a response. This paper discusses
the current results of analyzing these data to derive estimates for distributions
of human susceptibility to different routes of exposure and types of adverse
effects. The degree of protection is tentatively evaluated by projecting the
incidences of effects that would be expected for a tenfold lowering of exposure
from a 5% incidence level if the population distribution of susceptibility were
truly log-normal out to the extreme tails, and if the populations, chemicals, and
responses that gave rise to the underlying data were representative of the cases
to which traditional uncertainty factor is applied. The results indicate that,
acting by itself, a tenfold reduction in dose from a 5% effect level is
associated with effect incidences ranging from slightly less than one in ten
thousand, for a median chemical/response, to a few per thousand, for chemicals
and responses that have greater human interindividual variability than 19 out of
20 typical chemicals/responses. In practice, for many of the cases where the
traditional tenfold factor is applied, additional protection is provided by other
uncertainty factors. Nevertheless, the results generate some reason for concern
that current application of traditional safety or uncertainty factor approaches
may allow appreciable incidences of responses in some cases.
PMID- 10676425
TI - Analysis of PBPK models for risk characterization.
AB - Adoption of a Bayesian framework for risk characterization permits the seamless
integration of different kinds of information available in order to choose and
parameterize risk models. It also becomes easy to disentangle uncertainty from
variability, through hierarchical statistical modeling. Appropriate numerical
techniques can be found, for example, in the recently developed arsenal of Markov
chain, Monte Carlo simulations. The developments in this area can actually be
viewed as extensions of the traditional or standard Monte Carlo methods for
uncertainty analysis. Following a brief review of the techniques, examples of
Bayesian analyses of physiologically-based pharmacokinetic models are presented
for tetrachloroethylene and dichloromethane. The discussion touches on some open
problems and perspectives for the proposed methods.
PMID- 10676426
TI - Uncertainty in risk characterization of weak carcinogens.
AB - Epidemiologic inference is subject to uncertainty that is inherent to
observational approaches. It was shown by the present analysis that an SMR of
1.4, as observed for 2,3,7,8-tetrachlorodibenzo-para-dioxin in the pooled
analysis by IARC, would be observed in the absence of carcinogenic risk, if the
smoking prevalence of cohort members was as low as 80%. It was also shown that a
1.4-fold increase in lung cancer risk among nonsmokers, which roughly corresponds
to a daily consumption of one cigarette, might be extremely difficult to identify
if the subjects are exposed to strong carcinogens such as those that result from
cigarette smoking. On the other hand, a genotoxic agent that increases the lung
cancer risk of smokers 1.4-fold, could increase the risk to nonsmokers by as much
as 6.3-fold. In light of these uncertainties in epidemiologic inference, attempts
to estimate the absolute risk in human populations by epidemiologic studies
should be made with caution.
PMID- 10676427
TI - Reducing uncertainty in the derivation and application of health guidance values
in public health practice. Dioxin as a case study.
AB - We were requested by the U.S. Environmental Protection Agency (EPA) to clarify
the relationships among the minimal risk level (MRL), action level, and
environmental media evaluation guide (EMEG) for dioxin established by the Agency
for Toxic Substances and Disease Registry (ATSDR). In response we developed a
document entitled "Dioxin and Dioxin-Like Compounds in Soil, Part I: ATSDR
Interim Policy Guideline"; and a supporting document entitled "Dioxin and Dioxin
Like Compounds in Soil, Part II: Technical Support Document". In these documents,
we evaluated the key assumptions underlying the development and use of the ATSDR
action level, MRL, and EMEG for dioxin. We described the chronology of events
outlining these different health guidance values for dioxin and identified the
areas of uncertainty surrounding these values. Four scientific assumptions were
found to have had a great impact on this process; these were: (1) the specific
uncertainty factors used, (2) the toxicity equivalent (TEQ) approach, (3) the
fractional exposure from different pathways, and (4) the use of body burdens in
the absence of exposure data. This information was subsequently used to develop a
framework for reducing the uncertainties in public health risk assessment
associated with exposure to other chemical contaminants in the environment.
Within this framework are a number of future directions for reducing uncertainty,
including physiologically based pharmacokinetic modeling (PBPK), benchmark dose
modeling (BMD), functional toxicology, and the assessment of chemical mixture
interactions.
PMID- 10676428
TI - Uncertainty in risk characterization and communication. Discussion.
PMID- 10676429
TI - Uncertainty in risk assessment. Current efforts and future hopes.
AB - The incorporation of sampling variability in estimates of excess risk has been
part of risk assessment practice for decades. Currently, there is a strong desire
to incorporate understanding of biological mechanisms into the models used for
exposure assessment and exposure-response modeling. In addition, representing
population heterogeneity in the assessment of risks and the identification of
sensitive subpopulations is of great concern. Finally, the communication of
uncertainty and variability remains a challenge to risk assessors. Based upon the
presentations of workshop faculty, a summary of current practice when addressing
uncertainty together with conjectures concerning future challenges for addressing
uncertainty, are presented.
PMID- 10676430
TI - Common themes at the workshop on uncertainty in the risk assessment of
environmental and occupational hazards.
PMID- 10676431
TI - New vistas for melanocortins. Finally, an explanation for their pleiotropic
functions.
AB - This paper presents a historical overview of melanocortin (MC) research from the
early investigations of the many noncorticotropic effects of peptide fragments of
adrenocorticotropic hormone to the present focus on the discovery and cloning of
the MC receptors (MCRs). Final acceptance of the passage of neuropeptides through
the blood-brain barrier provided the scientific basis for the neuropeptide
concept, formulated previously by both De Weid and Kastin, that peripherally
administered neuropeptides affect neural processes. The discussion includes
melanocortin effects on behavior, the cardiovascular system, central and
peripheral electrophysiological parameters, food intake, inflammation and
analgesia, nerve regeneration and neuroprotection, and development. The
localization of specific MCRs in both neural and nonneural tissues is correlated
with the pleiotropic effects discussed.
PMID- 10676432
TI - Vasoactive intestinal peptide. Link between electrical activity and glia-mediated
neurotrophism.
AB - Vasoactive intestinal peptide has neurotrophic and neuroprotective properties
that influence the survival of activity-dependent neurons in the central nervous
system. Investigations of the mechanism of this neurotrophic peptide indicated
that these actions are contingent on interactions with astroglia. The complex
mixture of neurotrophic mediators released from astroglia include cytokines, a
protease inhibitor, and activity-dependent neurotrophic factor, a protein with
apparent structural similarities to hsp60. Investigations of ADNF resulted in the
discovery of active peptides of extraordinary potency and broad neuroprotective
properties. These studies indicate that a nine-amino acid core peptide of ADNF
had significantly greater neuroprotective properties in comparison to the parent
growth factor and these advantages identify ADNF-9 as an attractive lead compound
for drug development.
PMID- 10676433
TI - Stress, corticotropin-releasing factor, and drug addiction.
AB - The neuropeptide corticotropin-releasing factor (CRE) and related neuropeptides
not only mediate hormonal responses to stressors but also have a neurotropic role
in the central nervous system to mediate behavioral responses to stressors. CRF
antagonists effectively block CRF responses and have effects opposite those of
CRF in many stress-related situations. Recent advances suggest that in addition
to CRF itself there is another CRF-related neuropeptide, urocortin, that may be
involved in stress-related responses, particularly those involving appetite. At
least two CRF receptors have been discovered to date, CRF-1 and CRF-2. CRF may be
involved in various aspects of the addiction cycle associated with drugs of
abuse. CRF appears to be activated during stress-induced reinstatement of drug
taking as well as acute withdrawal from all major drugs of abuse. CRF is
hypothesized to be part of an allostatic change leading to vulnerability to
relapse during prolonged abstinence from drugs of abuse.
PMID- 10676434
TI - Evolution of the corticotropin-releasing hormone signaling system and its role in
stress-induced phenotypic plasticity.
AB - Developing animals respond to variation in their habitats by altering their rates
of development and/or their morphologies (i.e., they exhibit phenotypic
plasticity). In vertebrates, one mechanism by which plasticity is expressed is
through activation of the neuroendocrine system, which transduces environmental
information into a physiological response. Recent findings of ours with
amphibians and of others with mammals show that the primary vertebrate stress
neuropeptide, corticotropin-releasing hormone (CRH), is essential for adaptive
developmental responses to environmental stress. For instance, CRH-dependent
mechanisms cause accelerated metamorphosis in response to pond-drying in some
amphibian species, and intrauterine fetal stress syndromes in humans precipitate
preterm birth. CRH may be a phylogenetically ancient developmental signaling
molecule that allows developing organisms to escape deleterious changes in their
larval/fetal habitat. The response to CRH is mediated by at least two different
receptor subtypes and may also be modulated by a secreted binding protein.
PMID- 10676435
TI - Corticotrophin-releasing hormone and CRH-binding protein. Differences between
patients at risk for preterm birth and hypertension.
AB - BACKGROUND: During pregnancy in the second and third trimester there is a
progressive rise in plasma CRH thought to be secreted by the placenta. Plasma CRH
BP inactivates CRH, which may prevent its peripheral action on the maternal
pituitary and myometrium. In the last few weeks of pregnancy CRH-BP decreases,
thereby causing an increase in free CRH or a CRH/CRH-BP complex available to play
a role in the onset of parturition. OBJECTIVE: We tested the hypothesis that
differences in CRH, CRH-BP, or a CRH/CRH-BP complex in patients at risk for
preterm birth (PTB) and hypertension (HYP) account for the differences in the
timing of parturition. METHODS: From a Behavior in Pregnancy Study database, we
identified 18 patients who had spontaneous PTB and 23 patients who developed HYP.
Both groups were case controlled and matched with patients who delivered at term
(Normal). Maternal plasma samples had been appropriately collected from these
patients at 18-20, 28-30, and 35-36 weeks gestational age. CRH levels were
measured by double antibody RIA kit and the CRH-BP by a immunoradiometric
technique. A CRH-BP/CRH dimer complex index was calculated. Statistical analysis
was done using Kruskal-Wallis test for two cases. RESULTS: Maternal CRH (pg/ml)
in the PTB cases compared to the HYP cases was significantly elevated at all
three time periods. Maternal CRH-BP (pg/ml) in the PTB versus HYP cases was
significantly lower at all three time periods in the PTB cases compared to the
HYP cases. Maternal CRH-BP/CRH dimer complex index was significantly lower in the
PTB cases at all three time periods than either the controls or the HYP cases,
suggesting excessive CRH. The mean GA at delivery for the PTB cases was
significantly lower than the control or HYP cases. CONCLUSIONS: These results
suggest that those patients at risk for PTB have significantly elevated CRH,
lower CRH-BP, and a reduced CRH-BP/CRH dimer complex index at all three time
periods of assessment.
PMID- 10676436
TI - Corticotrophin-releasing hormone and fetal responses in human pregnancy.
AB - During human pregnancy, maternal and fetal compartments of the human placenta
produce and release corticotrophic-releasing hormone (CRH). Elevations of
placental CRH are associated with decreased gestational length (including preterm
delivery). The effects of elevated placental CRH on human fetal neurological
development are not known. Pregnant women in the 31st and 32nd week of gestation
consented to procedures for collection of blood and measurement of fetal heart
rate (FHR) in response to a series of 40 vibro-acoustic stimuli (VAS). Measures
of habituation and dishabituation were calculated from the FHR. All subjects were
followed to delivery. Fetuses (N = 33) of women with highly elevated CRH were
least responsive (p < .03) to stimulation after presentation of a novel
(dishabituating) stimulus with control for parity, fetal gender, medical
(antepartum) risk, and gestational length at term. In a larger sample (N = 156) a
polynomial model predicted the pattern of FHR reactivity for the first 15 trials.
Placental CRH concentration significantly predicted FHR reactivity after
controlling for the effects of trial number, baseline FHR, inter-trial interval,
and presence of uterine contractions. Increased maternal CRH levels were
significantly related to the length of gestation after controlling for the
effects of fetal gender, parity, and medical risk (p = .05). The relationship
between length of gestation and FHR was not significant suggesting separate
actions of CRH on these events. Elevated placental CRH appears to accelerate
certain developmental events (gestational length) and may influence the fetal
nervous system. The impaired fetal responses to novelty and increased arousal
observed in this study suggest that neurological systems may be targets for
placental CRH during sensitive developmental periods.
PMID- 10676437
TI - Short- and long-term consequences of corticotropin-releasing factor in early
development.
AB - Corticotropin-releasing factor (CRF) mediates various stress-related responses in
adult animals. Little is known about the effects of CRF during early development.
Young mammals often vocalize when isolated in novel surroundings. Heightened
levels of CRF inhibit vocalizing in isolated rat and guinea pig pups. Still lower
levels of CRF may facilitate or permit vocalizing in rat pups. In guinea pigs,
CRF appears to move pups from an initial active, to a subsequent passive, stage
of behavioral responsiveness. CRF activity prior to birth can also affect the
young. Exposing pregnant female rats to stressors during the last trimester of
pregnancy alters the morphological and behavioral development of the offspring.
Effects of gestational stress can be mimicked by injecting pregnant females with
CRF during the last trimester. CRF appears to mediate both short- and long-term
responses to stressors during developmental in rodents.
PMID- 10676438
TI - Vasoactive intestinal peptide regulates embryonic growth through the action of
activity-dependent neurotrophic factor.
AB - Activity-dependent neurotrophic factor is a potent, neuroprotective protein
released from astroglia by VIP and accounts in part for the neuroprotective
properties of this neuropeptide. The growth-regulatory actions of VIP during
embryogenesis may also occur indirectly through the release of activity-dependent
neurotrophic factor. Whole cultured day-9 mouse embryos treated with activity
dependent neurotrophic factor (10(-13) M) for 4 hr grew 3.1 somites, compared
with 1.6 somites in control embryos. Treated embryos appeared morphologically
normal and exhibited significant increases in cross-sectional area, protein, and
DNA content and bromodeoxyuridine incorporation. Anti-activity-dependent
neurotrophic factor significantly inhibited growth. Co-treatment of embryos with
anti-activity-dependent neurotrophic factor inhibited VIP-stimulated growth;
however, anti-VIP did not inhibit activity-dependent neurotrophic factor-induced
growth. These data indicate that an activity-dependent neurotrophic factor-like
substance is an endogenous embryonic growth factor and that VIP-regulated growth
occurs, at least in part, through activity-dependent neurotrophic factor.
PMID- 10676439
TI - Regulation of postimplantation mouse embryonic growth by maternal vasoactive
intestinal peptide.
AB - Vasoactive intestinal peptide (VIP) is an identified regulator of growth in the
embryonic day (E) 9-11 mouse. Mouse embryonic and extra-embryonic tissues were
studied to identify the source of VIP at this critical time. VIP and mRNA was
detected in the decidua/trophoblast at E8 and declined until E10, after which it
was not detectable. VIP mRNA was not apparent in the embryo until E11-E12. At E9,
cells in decidua had VIP as well as lymphocyte marker (delta and CD3)
immunoreactivity. VIP binding sites were dense in the decidua/trophoblast at E6,
which gradually decreased until E10. VIP binding sites were detected in embryonic
neuroepithelium by E9. The transient presence of VIP binding sites and mRNA in
the decidua/trophoblast correlate with the identified period of VIP growth
regulation, when VIP mRNA is absent in the embryo. Therefore, these findings
suggest that maternal decidual lymphocytes are the source of VIP that regulate
early postimplantation embryonic growth.
PMID- 10676440
TI - VIP neuroprotection against excitotoxic lesions of the developing mouse brain.
AB - Intracerebral administration of the excitotoxin ibotenate to new-born mice
induced white-matter lesions mimicking the periventricular leukomalacia occurring
in human premature babies. In this model, co-injection of vasoactive intestinal
peptide (VIP) prevented white-matter lesions. VIP did not prevent the initial
appearance of white-matter lesion, but promoted a secondary repair with axonal
regrowth. Co-administration of ibotenate, VIP, and transduction inhibitors showed
that protein kinase C (PKC) and mitogen-associated protein kinase (MAPK) pathways
were critical for neuroprotection. The combination of in vitro and in vivo
studies suggested the following model: VIP activates PKC in astrocytes, which
release soluble factors; these released factors activate neuronal MAPK and PKC,
which will permit axonal regrowth. Previous studies had shown that VIP-treated
cultured astrocytes release growth factors including activity-dependent
neurotrophic factor (ADNF) and that a 14-amino-acid peptide derived from ADNF
protected the developing white matter against ibotenate. However, co-treatment
with ibotenate, VIP, and anti-ADNF antibodies did not abolish VIP-induced
protection, suggesting that ADNF does not mediate VIP protective properties in
the present model.
PMID- 10676441
TI - A novel signaling molecule for neuropeptide action: activity-dependent
neuroprotective protein.
AB - The complete coding sequence of a novel protein (828 amino acids, pI 5.99), a
potential new mediator of vasoactive intestinal peptide (VIP) activity was
recently revealed. The expression of this molecule, activity-dependent
neuroprotective protein (ADNP), was augmented in the presence of VIP, in cerebral
cortical astrocytes. The mRNA transcripts encoding ADNP were enriched in the
mouse hippocampus and cerebellum. The protein deduced sequence contained the
following: (1) a unique peptide, NAPVSIPQ, sharing structural and immunological
homologies with the previously reported, activity-dependent neurotrophic factor
(ADNF) and exhibiting neuroprotection in vitro and in vivo; (2) a glutaredoxin
active site; and (3) a classical zinc binding domain. Comparative studies
suggested that the peptide, NAPVSIPQ (NAP), was more efficacious than peptides
derived from ADNF. ADNP, a potential mediator of VIP-associated neuronal
survival, and the new peptide, a potential lead compound for drug design, are
discussed below.
PMID- 10676442
TI - Endomorphins: novel endogenous mu-opiate receptor agonists in regions of high mu
opiate receptor density.
AB - Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2, EM-1) and endomorphin-2 (Tyr-Pro-Phe-Phe-NH2,
EM-2) are peptides recently isolated from brain that show the highest affinity
and selectivity for the mu (morphine) opiate receptor of all the known endogenous
opioids. The endomorphins have potent analgesic and gastrointestinal effects. At
the cellular level, they activate G-proteins (35S-GTP gamma-S binding) and
inhibit calcium currents. Support for their role as endogenous ligands for the mu
opiate receptor includes their localization by radioimmunoassay and
immunocytochemistry in central nervous system regions of high mu receptor
density. Intense EM-2 immunoreactivity is present in the terminal regions of
primary afferent neurons in the dorsal horn of the spinal cord and in the medulla
near high densities of mu receptors. Chemical (capsaicin) and surgical
(rhizotomy) disruption of nociceptive primary afferent neurons depletes the
immunoreactivity, implicating the primary afferents as the source of EM-2. Thus,
EM-2 is well-positioned to serve as an endogenous modulator of pain in its
earliest stages of perception. In contrast to EM-2, which is more prevalent in
the spinal cord and lower brainstem, EM-1 is more widely and densely distributed
throughout the brain than EM-2. The distribution is consistent with a role for
the peptides in the modulation of diverse functions, including autonomic,
neuroendocrine, and reward functions as well as modulation of responses to pain
and stress.
PMID- 10676443
TI - The ontogeny of endomorphin-1- and endomorphin-2-like immunoreactivity in rat
brain and spinal cord.
AB - Endomorphin-1 and endomorphin-2 are recently described peptides with high
affinity and specificity for the mu opioid receptor. They are believed to be the
endogenous ligands for that receptor. We describe the maturation of the
endomorphins in brain and spinal cord using recently characterized antibodies to
each. Endomorphin-1-like immunoreactivity was examined in brain, focusing on the
periaqueductal gray of the midbrain and the diagonal band of Broca; endomorphin-2
like immunoreactivity is reported for the medulla and spinal cord. In these
regions, and in all other regions studied but not described in this paper, the
endomorphins were not seen at birth or at 3 days of age. Staining was present in
7-day-old and older animals. At these early ages, the pattern and density of
staining are not fully developed, but appear complete by 21 days of age. The
results suggest that both endomorphin-1 and endomorphin-2 develop relatively late
compared to other opioid peptides.
PMID- 10676444
TI - Pain inhibition by endomorphins.
AB - Spinal analgesic effects of endomorphin-1 and endomorphin-2 were studied during
acute, inflammatory, and neuropathic pain in rats chronically implanted with
intrathecal cannulas. Endomorphin-1 and endomorphin-2 (2.5-10 micrograms i.t.),
as well as their analogues, increased the tail-flick and the paw pressure
latencies. In a model of inflammatory pain, the formalin-induced behavior was
attenuated by endomorphins; however, the effect studied was not dose-dependent
and was less pronounced in comparison with that evoked by morphine. On the other
hand, in rats with a sciatic nerve injury (crush), endomorphins antagonized
allodynia in a dose-dependent manner, whereas morphine was found to be
ineffective in a similar dose range. Endomorphins also exhibited an
antinociceptive potency in rats tolerant to morphine. In conclusion, our results
show a powerful analgesic action of endomorphins at the spinal level. The most
interesting finding is a strong effect of endomorphins in neuropathic pain, which
opens up a possibility of using these compounds in pain therapy.
PMID- 10676445
TI - Vasodilator responses to the endomorphin peptides, but not nociceptin/OFQ, are
mediated by nitric oxide release.
AB - The endomorphin peptides, endogenous ligands for the mu-opioid receptor, and
nociceptin (orphanin FQ; OFQ), an endogenous ligand for the ORL1 receptor, have
substantial vasodilator activity in the rat. The roles of nitric oxide,
vasodilator prostaglandins, and the opening of K+ATP channels in mediating
vasodilator responses to these novel agonists were investigated in the
hindquarters vascular bed of the rat. Under constant-flow conditions, injections
of the mu-selective agonists, endomorphin 1 and 2, PL017 ([N-MePhe3, D-Pro4]
morphiceptin), and DAMGO, and the ORL1 receptor agonist, nociceptin/OFQ, produced
dose-dependent decreases in hindquarters perfusion pressure. Vasodilator
responses to endomorphin 1, PL017, and DAMGO were attenuated by the nitric oxide
synthase inhibitor L-NAME at a time when vasodilator responses to nociceptin/OFQ
were not altered. Responses to endomorphin 1 and 2, PL017, DAMGO, and
nociceptin/OFQ were not altered by the cyclooxygenase inhibitor sodium
meclofenamate or the K+ATP channel blocker U-37883A. The results of these studies
indicate that responses to endomorphin 1 and 2, PL017, and DAMGO are mediated in
large part by the release of nitric oxide, while responses to nociceptin/OFQ are
mediated by an L-NAME-insensitive mechanism. Moreover, these results demonstrate
that responses to these peptides are not mediated by the release of vasodilator
prostaglandins or K+ATP channel opening in the hindquarters vascular bed.
PMID- 10676446
TI - Brain tachykinins and the regulation of salt intake.
AB - The regulation of salt intake is achieved through the coordination of behavioral
and physiological responses. Brain neuropeptides, such as the tachykinins, play
an important role in orchestrating both of these responses. Intraventricular
injections of NK3 receptor agonists, such as senktide, are potent in suppressing
salt intake. Experimental results show that intraventricular injections of
senktide that suppress salt intake have no effect on the ingestion of other
tastes, such as sucrose. The means by which senktide suppresses salt intake was
investigated in a series of experiments. Taste reactivity and lick rate analyses
suggest that the activation of NK3 receptors reduces salt intake by modulating
the oral-stimulating property of salt taste.
PMID- 10676447
TI - Neurotransmitter interaction in release of intranuclear oxytocin in magnocellular
nuclei of the hypothalamus.
AB - Oxytocin (OT) is released within the paraventricular (PVN) and supraoptic (SON)
nuclei of the hypothalamus in response to several stimuli. However, the
neurotransmitters that control this intranuclear OT release are unknown. In vivo
microdialysis was used to examine the roles of norepinephrine and histamine in
intranuclear OT release in conscious, lactating female rats. Administration of
alpha- or beta-noradrenergic agonists, or histamine, increased OT release in the
PVN. In addition, the increase in PVN OT evoked by exogenous histamine was
prevented by simultaneous blockade of either H1 or H2 receptors. Furthermore,
histamine-induced release of intranuclear OT was also prevented by blockade of
alpha-adrenergic receptors. Finally, the increase in magnocellular OT release
induced by suckling was abolished by administration of alpha-adrenergic
antagonists. These data demonstrate that norepinephrine and histamine are
important neurotransmitters for release of intranuclear OT, and histamine
releases intranuclear OT by stimulating norepinephrine release.
PMID- 10676448
TI - The role of brain-gut peptides in the control of sodium appetite.
AB - Ingestion of food and fluid stimulates release of a number of peptides from the
gastrointestinal system. These peptides are recognized to act as
neurotransmitters/neuromodulators and act at both peripheral and central
receptors. Many studies indicate that these peptides are important signals in
terminating meals. Recent studies suggest that bombesin, a peptide related to
gastrin-releasing peptide, suppresses sodium appetite. We have investigated the
role of cholecystokinin (CCK) in the control of sodium appetite. Our studies
indicate that CCK is effective at reducing saline intake. We found that
exogenous, intraperitoneal CCK octapeptide suppresses saline intake. Moreover,
administration of trypsin inhibitor to stimulate endogenous CCK release resulted
in suppression of saline intake. Finally, intraperitoneal administration of the
CCK receptor antagonist lorglumide resulted in increased saline intake. These
observations extend the potential role of gastrointestinal peptides in the
modulation of ingestive behavior.
PMID- 10676449
TI - Endogenous vasopressin modulates the cardiovascular responses to exercise.
AB - The role of brain-stem vasopressinergic projections in the genesis of reflex
bradycardia and in the modulation of heart rate control during exercise is
discussed on the basis of both changes in endogenous peptide content and heart
rate changes observed during exercise. Dynamic running caused an increase in
vasopressin content specifically in dorsal and ventral brain-stem areas. Rats
pretreated with vasopressin or the V1 receptor antagonist into the nucleus
tractus solitarii (NTS) showed a significant potentiation or a marked blunting of
the exercise tachycardia, respectively, without any change in the blood pressure
response. It is proposed that long-descending vasopressinergic pathways from the
hypothalamus to the NTS serves as one link between the two main neural
controllers of the circulation, that is, the central command and feedback control
mechanisms driven by the peripheral receptors signals. Therefore vasopressinergic
input contributes to the adjustment of heart rate response (and cardiac output)
to the circulatory demand during exercise.
PMID- 10676450
TI - Pharmacology of FMRFamide-related peptides in helminths.
AB - Nervous systems of helminths are highly peptidergic. Species in the phylum
Nematoda (roundworms) possess at least 50 FMRFamide-related peptides (FaRPs),
with more yet to be identified. To date, few non-FaRP neuropeptides have been
identified in these organisms, though evidence suggests that other families are
present. FaRPergic systems have important functions in nematode neuromuscular
control. In contrast, species in the phylum Platyhelminthes (flatworms)
apparently utilize fewer FaRPs than do nematodes; those species examined possess
one or two FaRPs. Other neuropeptides, such as neuropeptide F (NPF), play key
roles in flatworm physiology. Although progress has been made in the
characterization of FaRP pharmacology in helminths, much remains to be learned.
Most studies on nematodes have been done with Ascaris suum because of its large
size. However, thanks to the Caenorhabditis elegans genome project, we know most
about the FaRP complement of this free-living animal. That essentially all C.
elegans FaRPs are active on at least one A. suum neuromuscular system argues for
conservation of ligand-receptor recognition features among the Nematoda.
Structure-activity studies on nematode FaRPs have revealed that structure
activity relationship (SAR) "rules" differ considerably among the FaRPs. Second
messenger studies, along with experiments on ionic dependence and anatomical
requirements for activity, reveal that FaRPs act through many different
mechanisms. Platyhelminth FaRPs are myoexcitatory, and no evidence exists of
multiple FaRP receptors in flatworms. Interestingly, there are examples of cross
phylum activity, with some nematode FaRPs being active on flatworm muscle. The
extent to which other invertebrate FaRPs show cross-phylum activity remains to be
determined. How FaRPergic nerves contribute to the control of behavior in
helminths, and are integrated with non-neuropeptidergic systems, also remains to
be elucidated.
PMID- 10676451
TI - Actions of nematode FMRFamide-related peptides on the pharyngeal muscle of the
parasitic nematode, Ascaris suum.
AB - The endogenous nematode peptides known as FMRFamide-related peptides (FaRPs) and
various "classical" transmitters have a range of effects on nematodes that result
in changes in behavior, particularly locomotion, including paralysis and
inhibition of feeding. This study describes the application of an in vitro
pharmacological approach to further delineate the action of a number of FaRP
neurotransmitters on feeding behavior. Contraction of Ascaris suum pharyngeal
muscle was monitored using a modified pressure transducer system that detects
changes in intrapharyngeal pressure and therefore contraction of the radial
muscle of the pharynx. The pharynx did not contract spontaneously. However,
serotonin (5-HT, 100 microM) stimulated rhythmic contractions and relaxations
(pumping) at a frequency of 0.5 Hz. The native nematode peptide, KNEFIRFamide
(AF1), inhibited the pumping elicited by 5-HT. The duration of inhibition was
concentration-dependent (1-1000 nM) with a threshold of 1 nM (n = 7).
KSAYMRFamide (AF8/PF3) also inhibited pharyngeal pumping. There was no observable
effect of any of the following nematode peptides on pharyngeal pumping behavior
(1-1000 nM; n = 8): AF2, AF3, AF4, AF6, AF16, PF1/CF1, PF2/CF2, or PF4. Thus,
interruption of pharyngeal processes, such as feeding, regulation of hydrostatic
pressure, and secretion, may provide a new site of anthelmintic action.
PMID- 10676452
TI - Neuropeptide gene families in the nematode Caenorhabditis elegans.
AB - Neuropeptides have diverse roles in the function and development of the nervous
system. With the completion of the sequencing of the C. elegans genome, rapid
identification of nematode neuropeptide genes is possible. To date, 41 C. elegans
neuropeptide genes have been identified. Of these genes, 20 genes, named flp
(FMRFamide-like peptide) genes, encode FMRFamide-related proteins (FaRPs).
Deletion of one of the flp genes, flp-1, results in several behavioral defects,
suggesting that at least one flp gene is not functionally redundant with other
flp genes. Twenty-one genes, named neuropeptide-like protein (nlp) genes, encode
peptides distinct from the FaRP family. The predicted nlp-1 and nlp-2
neuropeptides have modest similarity to buccalin and myomodulin, respectively.
Cellular expression patterns and genetic analysis of flp and nlp genes suggest
that neuropeptides in nematodes also have widespread and varied roles in nervous
system function.
PMID- 10676453
TI - Comparison of FaRP immunoreactivity in free-living nematodes and in the plant
parasitic nematode Heterodera glycines.
AB - The family of FMRFamide-related peptides (FaRPs) is widely distributed among
invertebrates, where the peptides serve as neuromodulators. Published reports
indicate that numerous FaRP sequences exist in free-living and animal parasitic
nematodes. Using a FMRFamide ELISA, FaRP immunoreactivity was detected in
extracts of the soybean cyst nematode, Heterodera glycines, in both sexes and at
all developmental stages. HPLC-ELISA results revealed a number of immunoreactive
components in H. glycines preparations, and a comparison with extracts of the
free-living nematodes Caenorhabditis elegans and Panagrellus redivivus showed
significant qualitative differences in FaRP immunoreactivity between the plant
parasite and the two free-living nematodes. Total and specific immunoreactivities
varied during H. glycines development, with the highest specific activity in
juveniles and males, and the highest total activity in mature females. Total
female immunoreactivity was located primarily within the mature eggs. A
significant portion, however, was associated with the female body, perhaps with
egg laying.
PMID- 10676454
TI - Structure, function, and expression of Drosophila melanogaster FMRFamide-related
peptides.
AB - In 1977, Price and Greenberg identified the tetrapeptide FMRFamide as a
cardioexcitatory molecule from mollusc. Subsequent to this discovery, FMRFamide
related peptides (FaRPs) have been identified in both invertebrates and
vertebrates. Peptides in the FaRP family contain a common RFamide C-terminus and
act as modulators and messengers of neural and gastrointestinal functions. Like
other organisms, Drosophila melanogaster contains several genes that encode for
numerous FaRPs. Elucidating the processing and activities of multiple FaRPs
encoded in a single precursor is critical to establishing their roles in
physiology. In this manuscript, we describe the distribution of FMRFamide
immunoreactive materials in the Drosophila central nervous system and gut, and
correlate it with the expression of specific FaRPs and their activities. The
unique distributions and biological activities of Drosophila FaRPs suggest that
the precursors are highly processed and the structurally related peptides are not
functionally redundant. The complete distribution of FaRPs in the central nervous
system and gut as detected by FMRFamide antisera is not accounted for by the sum
of the individual expression patterns of the known Drosophila peptides. Thus,
these data suggest that one or more Drosophila FaRPs or structurally related
peptides remain to be discovered.
PMID- 10676455
TI - Stimulation of alpha-amylase release in the scallop Pecten maximus by the
myosuppressins. Structure-activity relationships.
AB - The insect myosuppressin LMS (pGlu-Asp-Val-Asp-His-Val-Phe-Leu-Arg-Phe-NH2)
elicits potent stimulation of the release of the digestive enzyme alpha-amylase
from cell suspensions of the stomach-digestive gland complex of the scallop
Pecten maximus. The myosuppressins are members of the FMRFamide-like peptide
superfamily, which immunocytochemical data confirm is present in the scallop.
Structure-activity studies indicated that the two most critical residues for
bioactivity are Arg and Phe. Bioactivity of the peptide can be maintained if the
basic, aromatic residue His is replaced by another basic residue (Lys) and
another aromatic residue (Trp), but not the aromatic Tyr, indicating a
sensitivity to the introduction of a phenolic OH group. A restricted-conformation
analogue containing a cyclopropyl-Ala residue in position 8 (Cpa-MS) demonstrates
an ability to antagonize the amylase secretion activity of LMS at microM
concentrations. This result provides evidence that the myosuppressins adopt a
tight turn in the C-terminal tetrapeptide active core region while binding to the
scallop digestive gland receptor. Cpa-MS may provide a useful tool to
neuroendocrinologists studying in vitro and in vivo digestive processes in
mollusks and other invertebrates.
PMID- 10676456
TI - The unique neuropeptide pattern in abdominal perisympathetic organs of insects.
AB - We successfully isolated and identified the abundant neuropeptides of the
abdominal perisympathetic organs of the American cockroach, including all
myoactive compounds. Peptide sequence analysis and mass spectrometry of abundant
substances that were not bioactive in different muscle assays yielded the
following sequences: TDPLWQLPGAHLEQYLS-NH2 (Pea-YLS-amide), AFLTLTPGSHVDSYVEA-OH
(Pea-VEAacid), and SDLTWTYQSPGDPTNSKN-OH (Pea-SKNacid). The given structures led
to the conclusion of an unique neuropeptide pattern in abdominal perisympathetic
organs. We confirmed this assumption with immunocytochemical studies, using
antisera raised against different myotropic neuropeptides of the abdominal
perisympathetic organs. Moreover, mass spectrometric methods, developed for the
investigation of single neurohemal organs, confirmed the neuropeptide pattern in
these organs.
PMID- 10676457
TI - Adipokinetic hormones. Coupling between biosynthesis and release.
AB - During long-distance flight of migratory locusts, the dramatic energy demand of
the flight muscles is controlled by three adipokinetic hormones (AKHs). These
peptide hormones regulate the mobilization of lipid and carbohydrate stored in
the fat body to serve as energy substrates for the flight muscles. Despite the
relatively huge quantities of the three AKHs that are stored in the corpora
cardiaca, flight induces a differential 2-4-fold increase in the mRNAs for the
three hormones. Moreover, newly synthesized AKHs can be released only during a
restricted period of time, suggesting that by far most of the stored hormones are
physiologically inactive. This raises the question of how the biosynthetic
activity in the AKH-producing cells is coupled to their secretory activity. The
present review discusses the potential mechanisms by which generation and release
of mixtures of bioactive neurohormones are controlled and how peptidergic
neuroendocrine cells cope with variations in physiological stimulation, with the
AKH-producing cells serving as a model system.
PMID- 10676458
TI - The regulation of juvenile hormone production in arthropods. Functional and
evolutionary perspectives.
AB - Although sesquiterpenoids are probably the ancestral regulators of reproduction
and secondarily of metamorphosis in arthropods, our discussion suggests that the
neuropeptides that regulate the biosynthesis of these compounds have arisen on
several distinct occasions. These peptides probably occurred originally as
regulators of other physiological processes and were subsequently co-opted for
the regulation of sesquiterpenoid biosynthesis, perhaps first in adult forms and
thereafter in larval forms. The evolution of peptides to assume additional
physiological functions probably occurred as a result of gene duplication, both
at the peptide level and at the receptor level. There are likely to be numerous
regulators of sesquiterpenoid biosynthesis in both Insecta and Crustacea, and
investigations to date have only begun to reveal the host of peptide families
involved in the regulation of juvenile hormone-related biosynthesis across the
arthropods.
PMID- 10676459
TI - Allatostatins: a growing family of neuropeptides with structural and functional
diversity.
AB - The high degree of conservation of the core sequence of the "cockroach-types" of
AST and their widespread distribution suggest that they should be considered a
ubiquitous family of peptides within the invertebrates, regulating a range of
important physiological processes. These functional processes, by either neural
or humoral routes of action, include the inhibition of endocrine function,
interneuronal functions, neuromodulatory roles, myotropic and myoendocrine roles,
and direct action on biosynthetic pathways. The myomodulatory function appears to
be conserved through evolutionary time, whereas the JH inhibitory activity
appears to be confined to specific orders. This suggests that the myomodulatory
role was the more ancestral of these two particular functions. Certainly, further
purification and gene cloning as a means to precursor identification and
functional analysis will be a prerequisite to understanding the diverse functions
of this peptide family.
PMID- 10676460
TI - The significance of Manduca sexta allatostatin in the tomato moth Lacanobia
oleracea.
AB - The nature and regulation of juvenile hormone (JH) biosynthesis have been
investigated in isolated corpora allata (CA) of adult males and females, and
larvae of the tomato moth Lacanobia oleracea (Noctuidae). Larval CA (Vth day 1 to
VIth day 1) appear to synthesize JH at very low rates (< 0.5 fmol/pr/h). This
synthesis was not affected by Manduca sexta allatostatin (Mas-AS) nor Manduca
sexta allatotropin. In contrast, adult female CA synthesize relatively high
levels of JHI and JHII (> 10 pmol/pr/h), each of which can be inhibited (approx.
60%) by Mas-AS. CA from adult male L. oleracea do not produce detectable levels
of JH but would appear to synthesize JH-acids instead, which can also be
inhibited (approx. 50%) by Mas-AS. When assayed on adult female L. oleracea CA,
brain extracts separated by liquid chromatography show inhibitory activity. The
major biologically active fraction also has the greatest Mas-AS-like
immunoreactivity and co-elutes with synthetic Mas-AS, indicating that most of the
allatostatic activity in brain extracts is due to a Mas-AS-like peptide. In adult
male brains, even though relatively high levels of immunoreactivity co-elute with
synthetic Mas-As, the majority of the Mas-AS-like immunoreactivity is more
hydrophobic.
PMID- 10676461
TI - Insect angiotensin-converting enzyme. A processing enzyme with broad substrate
specificity and a role in reproduction.
AB - Insect angiotensin-converting enzyme (ACE) is a peptidyl dipeptidase that removes
dipeptides and dipeptideamides from the C-terminus of a broad range of in vitro
oligopeptide substrates. In mammals, ACE has important roles in blood homeostasis
and a recently recognized, but as yet undefined, role in the fertility of male
mice. High levels of ACE are found in the male reproductive tissues of several
insect species, and emerging data indicates an important role for the enzyme in
insect reproduction. In this paper we review some of the recent findings about
insect ACE, and we speculate as to the physiological role of this enzyme in
insect reproduction.
PMID- 10676462
TI - Development of amphiphylic mimics of insect neuropeptides for pest control.
AB - Insect neuropeptides regulate virtually all aspects of insect life and are
excellent candidates for development of new methods for pest control. However,
they do not penetrate insect cuticle and are degraded by enzymes both in the
digestive system and hemolymph. We have designed mimics of model neuropeptides by
attachment of various lipidic moieties to the amino terminus of the bioactive
core of the neuropeptides. These mimics have amphiphylic characteristics that
allowed them to penetrate the hydrophobic insect cuticle. The mimics also induced
prolonged physiological responses (up to 20 hours) and were resistant to
peptidase attack. This knowledge has been used to develop a novel, species
specific approach to insect control.
PMID- 10676463
TI - The kinin peptide family in invertebrates.
AB - Kinins comprise a family of peptides that were first found in the central nervous
system of insects and recently also in mollusks and crustaceans. After the
isolation of the first members of the kinin family, the leukokinins from
Leucophaea maderae, leukokinin-related peptides were found in the cricket Acheta
domesticus and the locust Locusta migratoria, all through their ability to induce
Leucophaea maderae hindgut contraction. Subsequently, kinins were found in the
mosquitoes Culex salinarius and Aedes aegypti and in the earworm Helicoverpa zea.
The first noninsect member of this family was isolated from a mollusk, the pond
snail Lymnaea stagnalis. Most recently our group has isolated the first kinins
from crustaceans. Six kinins were isolated from the white shrimp Penaeus
vannamei. To date, 35 members of this family have been isolated. The first
relatively small family of insect kinins has grown into an expanding and rather
large family with members in insects, crustaceans, and mollusks. In this paper we
discuss the kinin family in terms of method of isolation, structure, in vitro and
in vivo activity, distribution, receptors, and signal transduction. We will
compare the crustacean and insect members of the kinin family, using the data
available on crustacea.
PMID- 10676464
TI - Tachykinin-like peptides and their receptors. A review.
AB - Tachykinin-like peptides have been identified in many vertebrate and invertebrate
species. On the basis of the data reviewed in this paper, these peptides can be
classified into two distinct subfamilies, which are recognized by their
respective sequence characteristics. All known vertebrate tachykinins and a few
invertebrate ones share a common C-terminal sequence motif, -FXGLMa. The insect
tachykinins, which have a common -GFX1GX2Ra C-terminus, display about 30% of
sequence homology with the first group. Tachykinins are multifunctional brain/gut
peptides. In mammals and insects, various isoforms play an important
neuromodulatory role in the central nervous system. They are involved in the
processing of sensory information and in the control of motor activities. In
addition, members of both subfamilies elicit stimulatory responses on a variety
of visceral muscles. The receptors for mammalian and insect tachykinins show a
high degree of sequence conservation and their functional characteristics are
very similar. In both mammals and insects, angiotensin-converting enzyme (ACE)
plays a prominent role in tachykinin peptide metabolism.
PMID- 10676465
TI - Comparison of active conformations of the insectatachykinin/tachykinin and insect
kinin/Tyr-W-MIF-1 neuropeptide family pairs.
AB - A comparison of solution conformations of active, restricted-conformation
analogues of two sequence-similar insect/vertebrate neuropeptide family pairs
shed light on the potential existence of molecular evolutionary relationships.
Analogues of the locustatachykinins and the mammalian tachykinin substance P,
containing a sterically hindered Aib-NMePhe/Tyr residue block, share similar low
energy turn conformations incorporating a cis peptide bond. Conversely,
restricted conformation analogues of the insect kinins and the mammalian opiate
peptide Tyr-W-MIF-1, with near identical C-terminal tetrapeptide sequences, adopt
different conformations. The insect kinins adopt a cisPro 1-4 beta-turn, in which
the Phe1 is critical for bioactivity. Tyr-W-MIF-1 prefers a transPro 2-5 turn,
and an additional N-terminal Phe severely inhibits mu-opiate receptor binding.
Comparisons of the chemical/conformational requirements for receptor interaction
are consistent with a distant evolutionary relationship between the
insectatachykinins and tachykinins, but not between the insect kinins and Tyr-W
MIF-1. Therefore, analogues of the insect kinins with pest control potential can
be readily designed to avoid mammalian interactions.
PMID- 10676466
TI - VIP and PACAP38 modulate cytokine and nitric oxide production in peritoneal
macrophages and macrophage cell lines.
PMID- 10676467
TI - Axonal plasticity in the rat pituitary intermediate lobe following chronic D2
receptor modulation.
PMID- 10676468
TI - Chronic intracerebroventricular infusion of beta-amyloid (1-40) results in a
selective loss of neuropeptides in addition to a reduction in choline
acetyltransferase activity in the cortical mantle and hippocampus in the rat.
PMID- 10676469
TI - Correlates of deoxycorticosterone-induced salt appetite behavior and basal
ganglia neurochemistry.
PMID- 10676470
TI - Co-localization of the inwardly rectifying potassium ion channel, Kir2.2, and the
substance P receptor in single locus coeruleus neurons.
PMID- 10676471
TI - Intraventricular injections of tachykinin NK3 receptor agonists affect salt
intake. A shift in taste intensity?
PMID- 10676472
TI - Dominance of nonphotic cues in the circadian rhythm of body temperature in
vasopressin-deficient rats.
PMID- 10676473
TI - Acquisition of improved reference values for cesium, iodine, strontium, thorium,
and uranium in selected NIST reference materials.
AB - As part of a study on the ingestion and organ content of some trace elements of
importance in radiological protection, additional work has been undertaken to
acquire improved reference values for cesium, iodine, strontium, thorium, and
uranium in four selected reference materials provided by the US National
Institute of Standards and Technology. The materials are SRM-1548 Total Diet, SRM
1548a Typical Diet, SRM-1486 Bone Meal, and RM-8414 Bovine Muscle. A coordinated
study was undertaken with the help of seven selected laboratories in five
countries. Instrumental and radiochemical neutron activation analysis and
inductively coupled plasma-mass spectrometry were the analytical main techniques
used.
PMID- 10676474
TI - Trends in trace element determinations in blood, serum, and urine of the Dutch
population, and the role of neutron activation analysis.
AB - A critical review on the quality of literature data on trace elements in human
blood, serum, and urine of inhabitants in the Netherlands has shown that many of
the currently available data have been established 15-20 years ago. Only in a few
publications are quality indicators mentioned, which should be considered typical
-and minimal--for studies resulting at reference values. The use of neutron
activation analysis for determination of trace elements in human body fluids was
restricted to a few studies in the 1970s. However, although it is frequently
assumed that the sensitivity of NAA might be insufficient, it is demonstrated
that modern, large, well-type Ge detectors may serve well for the determination
of trace elements in human body fluids via radiochemical NAA, for example.
PMID- 10676475
TI - INAA of serum zinc of inhabitants in five regions of the Czech Republic.
AB - To investigate the Zn status of inhabitants of the Czech Republic, 1155 serum and
132 hair samples were analyzed for zinc content. Analyzed material was obtained
from randomly selected volunteers of both sexes in the age range 6-65 yr.
Subpopulations from five regions were included in the study. Analyses of both
materials were performed by Instrumental Neutron Activation Analysis (INAA).
Coanalyses of Standard Reference Materials (SRM) for quality control were
performed. The results (mean 910 +/- 276 micrograms Zn/L serum and 189 +/- 45
micrograms Zn/g hair) demonstrate satisfactory zinc status of the searched
population. Significant interregional differences and age-dependent differences,
as well as sex-dependent differences have been detected by the use of correlation
analysis. On the basis of these results, serum Zn concentration results of
individual categories according to age and sex were evaluated, and on the grounds
of mean +/- 2 standard deviations, indicative intervals were calculated. The
frequency of individual serum Zn concentrations proved that the population of the
Czech Republic does not suffer from severe zinc deficiency. On the other hand,
about one-third of our inhabitants has their serum Zn concentrations below the
cutoff value of 800 micrograms Zn/L serum, which means a marginal or mild Zn
deficit of the organism.
PMID- 10676476
TI - Characterization of selenium status of inhabitants in the region Usti nad Orlici,
Czech Republic by INAA of blood serum and hair and fluorimetric analysis of
urine.
AB - Selenium is an essential trace element and its insufficient status may cause
serious health complications for both individuals and the whole populations. To
investigate the selenium status of the subpopulation in northeastern Bohemia
represented by the region Usti nad Orlici, 253 serum, 469 urine, and 31 hair
samples from 470 randomly selected volunteers between 6 and 65 yr of age have
been analyzed for selenium concentration. Serum and hair Se were detected by
instrumental neutron activation analysis (means: 55 +/- 11 micrograms Se/L sera,
0.268 +/- 0.040 microgram Se/g hair). Urine Se was measured by fluorimetry (12 +/
5 micrograms Se/L urine) with coanalyses of Lyphocheck urine, SRM Urine 2670,
and Seronorm urine for quality control of the method. Results proved significant
age-dependent differences, but gender differences were not significant. The
frequency plot of serum Se proved maximal frequencies in adults between 55 and 70
micrograms Se/L and in children in the range 45-55 micrograms Se/L. The same
plots of urine Se for both age groups showed maximal frequency in the limits 8-15
micrograms Se/L. All indices used (Se in serum, urine, and hair) confirmed mild
to severe selenium deficiency in the population of the region.
PMID- 10676477
TI - Instrumental neutron activation analysis of rib bone samples and of bone
reference materials.
AB - The instrumental neutron activation analysis method was used for the
determination of trace elements in rib bone samples taken from autopsies of
accident victims. The elements Br, Ca, Cl, Cr, Fe, Mg, Mn, Na, P, Sr, Rb, and Zn
were determined in cortical tissues by using short and long irradiations with
thermal neutron flux of the IEA-R1m nuclear reactor. The reference materials NIST
SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were also analyzed in order to
evaluate the precision and the accuracy of the results. It was verified that
lyophilization is the most convenient process for drying bone samples because it
does not cause any element losses. Comparisons were made between the results
obtained for rib samples and the literature values as well as between the results
obtained for different ribs from a single individual and for bones from different
individuals.
PMID- 10676478
TI - IAEA Internet database of natural matrix reference materials.
AB - The International Atomic Energy Agency maintains a database on internationally
available certified reference materials of natural origin. The database was
updated in 1998 and prepared for an Internet implementation. A user-friendly
structure was created, providing two main pathways for browsing, either according
to the matrix classification or the producer's name. The database presently
contains over 20,000 values for 480 measurands and 1085 reference materials from
43 different producers. Most of the materials entered contain values for trace
and minor elements (66%).
PMID- 10676479
TI - Microbeam PIXE analysis of Na, K, Mg, and Ca in severely damaged cardiac tissue.
AB - The aim of the study was to measure with microbeam PIXE elements such as Na, K,
Mg, and Ca in cardiac tissue after various treatments in vivo, which affect the
cardiomyocyte integrity. It was assumed that local deviations from normal
electrolyte levels indicate the degree of cardiac damage. The first step in this
feasibility study was comparison of severely damaged cardiac tissues with
controls. Severe cardiac damage was introduced by the so-called Ca paradox.
Experiments were performed with isolated rat hearts, perfused retrogradely with
an oxygenated crystalloid buffer. Results indicated that severe cardiac damage
was accompanied with almost complete disappearance of the normal intracellular
electrolyte composition as a result of the loss of membrane integrity.
Identifications of smaller and more locally present ischemic damages on basis of
altered electrolyte levels appeared to be feasible. However, the prerequisite was
that the mobility of electrolytes be kept under control during tissue sampling
and sample preparation, when physiological mechanisms stop to maintain gradients.
PMID- 10676480
TI - Nuclear microscopy in the life sciences at the National University of Singapore.
A review.
AB - The nuclear microscope is now gaining popularity in the field of life sciences.
In particular, the combination of proton-induced X-ray emission to measure the
elemental concentrations of inorganic elements, Rutherford backscattering
spectrometry to characterize the organic matrix, and scanning transmission ion
microscopy to provide information on the density and structure of the sample
represents a powerful set of techniques that can be applied simultaneously to the
specimen under investigation. These techniques are extremely useful for measuring
any imbalances in trace elements in localized regions of biological tissue and,
as such, can provide unique information on many diseases. In this article, we
describe the nuclear microscope and its related ion-beam techniques, and we
review the biomedical work carried out using the nuclear microscope in the
National University of Singapore.
PMID- 10676481
TI - An external ion microbeam for studies of biological samples.
AB - A new external ion-beam system was developed and combined with a light ion
microbeam system in JAERI Takasaki. The system is designed for micro-particle
induced X-ray emission analysis of biological samples in air environment with 1
micron spatial resolution. One of the most serious problems in keeping such a
high spatial resolution is multiple scattering in a beam exit window. Thin Kapton
film (7.5 microns thick) was adopted as the exit window as well as a sample
backing foil to minimize the distance between the film and samples. The lifetime
of the foil under ion irradiation and spatial resolution of the external
microbeam were investigated. The results shows that the film can endure
sufficient long-time irradiation to take elemental maps and the resolution can be
kept nearly 1 micron.
PMID- 10676482
TI - Improvements in the determination of radionuclide distribution in the analysis of
irradiated samples using double-differentiation method.
AB - The spatial response of an 8 x 4 block detector made up of 5.6-mm-wide, 12.9-mm
high, 30-mm-thick individual detector crystals to a collimated line source of 511
keV annihilation photons was examined. The response of each crystal showed a
spread around the average positioning values and distributions from adjacent
crystals overlapped as the collimated source scanned the individual detectors.
This leads to possible errors in the event assignment. The implementation of
double differentiation or the second derivative method was proposed for the
removal of scattered photons so as to reduce the overlap and, hence, avoid mis
positioning. This method is a mathematical solution implemented when analysing
the results. A curve in a spatial spectrum could be considered to be a function
f(x), where x is the position. When double differentiation of f(x) is carried
out, then the normalized curve d2f(x) appears with some reduction in the wings.
It was shown that a reduction of the scattering contribution in the tails without
overestimating the contribution of scattered events could be achieved by
implementing a double-differentiation process.
PMID- 10676483
TI - Radiotracer analysis of cadmium speciation in soil solutions using
electrophoresis, dialysis, centrifugation, and ultrafiltration.
AB - Speciation of carrier-free 109Cd, added in cationic form to pre-filtered extracts
obtained by leaching forest soil samples with distilled water, was analyzed using
electrophoresis, dialysis, centrifugation, and ultrafiltration. Rapid
establishment of isotopic equilibrium between the added 109Cd and stable cadmium
present in the extracts was observed. All the data obtained indicated that 109Cd
and also stable cadmium were present in the analyzed extracts in the form of
neutral or negatively charged organic complexes or small colloids. The results of
electrophoresis enabled the characterization, at least semiquantitative, of the
abundance and electrophoretic mobility of the forms present. The incomplete
dialysis of 109Cd from the soil extracts through cellophane membrane against
water proved the presence of organic associates with molecular weights higher
than 10(4). Dialysis against the same, but unlabeled extract was always complete,
indicating the reversible (labile) nature of the organic forms of cadmium.
Assessment of the stability constants of the organic forms using a simple
discrete two-site model suggested that humate and/or fulvate complexes of cadmium
were formed.
PMID- 10676484
TI - Study on binding of REEs with water-soluble polysaccharides in fern.
AB - The binding of rare earth elements (REEs) with water-soluble polysaccharides of
nondeproteinization and deproteinization in the leaves of the fern Dicranopteris
dichotoma was studied by molecular activation analysis (MAA). Two cold-water
soluble polysaccharides (extracted by 75% ethanol and 90% ethanol, respectively)
and one hot-water-soluble polysaccharide (extracted by 90% ethanol) were
separated using biochemical separation techniques. The eight rare earth elements
(La, Ce, Nd, Sm, Eu, Tb, Yb, and Lu) in these polysaccharides were determined by
instrumental neutron activation analysis. Our new results showed that the REEs
were bound firmly with the water-soluble polysaccharides in the plant, regardless
of whether nondeproteinization or deproteinization was used. The molecular-weight
(MW) measurement demonstrated that REEs were mainly bound with low-MW (10,000
20,000) polysaccharides.
PMID- 10676485
TI - Correlation between total and EDTA/DTPA-extractable trace elements in soil and
wheat.
AB - Wheat and wheat products are more important sources of energy and nutrients in
diets of people in many cultures compared to other foods. The daily consumption
of wheat is about 200 g/d/person in Western Europe and North America. On the
other hand, 400-450 g of wheat and wheat products are consumed daily by average
Turkish people. Wheat samples collected from the Iskenderun region in 1995 and
1996 and Ankara and Istanbul regions in 1995 were analyzed for their trace
element content by instrumental neutron activation analysis (INAA). In addition,
13 soil samples were collected from the Iskenderun region in 1996. Total soil
samples were analyzed by INAA and atomic absorption spectrometry (AAS), EDTA
extractable elements by INAA, and DTPA-extractable elements by AAS. Correlation
analysis and enrichment factor calculations were applied to the trace element
results. In wheat samples, a strong correlation was found between the elements
such as Sc, La, Sm, Rb, and K whose main source is soil. The concentration of Se
appeared to show larger variations among different regions. No significant
correlation was observed for elements such as As and Se whose main sources in the
atmosphere are anthropogenic activities.
PMID- 10676486
TI - Comparison of the chromium distribution in organs and subcellular fractions of
normal and diabetic rats by using enriched stable isotope Cr-50 tracer technique.
AB - The enriched stable isotope 50Cr(III) tracer technique combined with neutron
activation analysis was used to examine the intracellular distribution of Cr(III)
in the liver, pancreas, testes, and kidney homogenates of both normal and
diabetic rats. Our new results showed that the nucleic fraction has the highest
Cr concentration in the liver cell of both normal and diabetic rats. The diabetic
rats retain more Cr in the mitochondrial and lysosomal fractions of liver
homogenate than the normal. This is likely an indication of chromium
participating in the glucose or lipid metabolism to compensate the low level of
insulin in the body of diabetic rats. The concentrations of Cr in the subcellular
fractions of pancreas, testes, and kidney in the normal rats are higher than
those in the diabetic rats, which favor the hypothesis that Cr(III) plays its
biological function via interaction with the insulin-sensitive tissues or
enhancement of the sensitivity of the insulin receptor.
PMID- 10676487
TI - Investigation of selenium distribution in subcellular fractions of human liver by
neutron activation analysis.
AB - Selenium is an important and essential trace element to living systems. In the
article, two methods of instrumental neutron activation analysis and hydride
generation-atomic fluorescence spectrometry were applied to determine Se in
biological samples and the accuracy was evaluated by several reference materials.
The subcellular distribution of selenium in human liver samples, which were
obtained from normal subjects who had an accidental death, was investigated by
differential centrifugation combined with INAA. Selenium was mainly enriched in
mitochondria, nuclei, and cytosol. Almost half of the total Se content existed in
nuclei as a result of the large amount in liver and the high Se concentration.
Generally, the highest Se concentration in the mitochondrial fractions of each
liver sample suggested that Se had important functions in this liver component.
PMID- 10676488
TI - Speciation of inorganic arsenic and selenium in leachates from landfills in
relation to water quality assessment.
AB - Speciation of arsenic and selenium was carried out on water samples taken from
rivers used as water intake points in the vicinity of landfill areas used for
land-based waste disposal system. Leachates from these landfill areas may
contaminate the river water through underground seepage or overflowing,
especially after a heavy downpour. Preconcentration of the chemical species was
done using a mixture of ammonium pyrrolidinethiocarbamate-chloroform (APDTC
CHCl3). Because only the reduced forms of both arsenic and selenium species could
be extracted by the preconcentrating mixture, suitable reducing agents such as
25% sodium thiosulfate for As(III) and 6M HCl for Se(IV) were used throughout the
studies. Care was taken to exclude the interfering elements such as the alkali
and alkali earth metals from the inorganic arsenic and selenium species by
introducing 12% EDTA solution as the masking agent. The extracted mixture was
irradiated in a thermal neutron flux of 4 x 10(12)/cm/s from a TRIGA Mk.II
reactor at the Malaysia Institute of Nuclear Technology Research (MINT). Gamma
rays of 559 keV and 297 keV from 76As and 75Se, respectively, were used in the
quantitative determination of the inorganic species. Mixed standards of As(III)
and Se(IV) used in the percentage efficiency procedure were prepared from salts
of Analar grade. The water quality evaluation was viewed from the ratio of the
inorganic species present.
PMID- 10676489
TI - Spatial distribution of extractable organohalogens in northern pink shrimp in the
north Atlantic.
AB - Extractable organohalogens (EOX) are organic compounds that contain chlorine,
bromine and/or iodine, which can be separated from the matrix by liquid/liquid or
liquid/solid extraction. A combination of instrumental neutron activation
analysis (INAA) and solvent extraction methods has been developed for the
determination of EOX from the shrimp Pandalus borealis. Levels of EOX were
evaluated for spatial trends for shrimp caught in several areas off the Labrador
coast, off the coast of Nova Scotia, and off the coast of Maine. Muscle contained
1.09-6.05 micrograms EOCl/g tissue and 105-498 micrograms extractable
organochlorine (EOCl)/g lipid; 0.0607-0.288 microgram extractable organobromine
(EOB)r/g tissue and 4.74-10.5 micrograms EOBr/g lipid; and 0.014-0.048 microgram
extractable organoiodine (EOI)/g tissue and 1.03-1.76 micrograms EOI/g lipid,
respectively. The levels of EOCl in roe were 1.60-12.34 micrograms/g tissue and
39.0-146 micrograms/g lipid. In roe, the EOBr levels were 0.707-1.03 micrograms/g
tissue and 6.96-13.5 micrograms/g lipid; and EOI levels were 0.123-0.349
microgram/g tissue and 1.42-4.11 micrograms/g lipid. The EOCl, EOBr, and EOI
levels in roe increased noticeably from north to south along the coast of
Labrador. Samples taken from the coast of Maine and from Canso Hole were
typically higher in EOCl levels than those taken from Labrador. The results for
EOBr and EOI were in the same range as those from Labrador.
PMID- 10676490
TI - Health-related monitoring and assessment of airborne particulate matter. An
overview of recent IAEA programs.
AB - Since 1992, the International Atomic Energy Agency (IAEA) has been promoting
studies of air pollution using a standard design of air sampler that provides
separation on filters into two size fractions with cutoffs of 2.5 and 10 microns
(approximately). These are the size ranges presently considered to have the most
important health consequences. Such filter samples are highly amenable to
analysis using nuclear and related techniques. After reviewing some of the health
effects of airborne particulate matter and current air quality standards and
guidelines, this article provides an overview of current and recent IAEA programs
in this area, which involve collaborative activities with participants in more
than 40 countries.
PMID- 10676491
TI - Characterization of airborne particulates in Bangkok urban area by neutron
activation analysis.
AB - Samples of airborne particulates were collected in a residential area and in an
area near a busy highway in Bangkok during the period from January 1997 to May
1998. A stacked filter system was used for the former site and a Partisol 2000
was used for the latter site. Both 2.5 microns and 10-micron particulates were
collected every week. The total suspended particulate matters were also collected
at the latter site. The samples were analyzed by neutron activation analysis
utilizing neutron flux from a 2-MW TRIGA MARK III research reactor. The elements
most frequently detected in the airborne particulates were Al, As, Br, Ca, Ce,
Cl, Co, Cr, Cs, Fe, I, K, La, Mg, Mn, Na, Rb, Sb, Sc, Sm, Th, Ti, V, and Zn. The
enrichment factor and factor analysis were used to investigate trends, sources,
and origin of the atmospheric aerosols. Anthropogenic elements in road dust,
construction dust, motor vehicles emission, and other combustion components were
identified. A comparative study of data between both sites was performed and it
was found that the mass concentration in the area close to the highway was about
three times higher than in the residential area.
PMID- 10676492
TI - A study of air particulate pollution in Colombo using a nuclear-related
analytical technique.
AB - Air particulate matter of two size fractions (coarse [2.5-10 microns] and fine
[less than 2.5 microns]) were collected at an urban residential site (Colombo
University ground) over a period of 12 mo during 1996 using a Gent PM10 stacked
filter unit. Seventy-five sets of samples collected during this period were
analyzed for 10 elements: Al, Si, K, S, Ca, Ti, Fe, Zn, Br, and Pb by energy
dispersive X-ray fluorescence, which is a multielement analysis. This is a highly
sensitive technique enabling quantitative analysis of very low masses. The
average concentrations of lead, sulfur, and bromine, which are generally
associated with combustion products of automotive exhausts, dominate the fine
fraction in this study. The minimum and maximum concentration of lead resulting
in an annual average of 0.09 microgram/m3 was found to be 0.0042 and 0.441
microgram/m3 in particulate matter with less than 10 microns equivalent
aerodynamic diameter. The maximum concentration determined is well below the
limits set by the World Health Organization (0.5-1.0 microgram/m3). The
recommended value for Pb in Sri Lanka is 0.5 microgram/m3. Al, Si, Ca, Ti, and Fe
exhibited enhanced concentrations in the coarse fraction, which probably
originate from disturbed soil as a result of wind and traffic.
PMID- 10676493
TI - Collection and characterization of a bulk PM2.5 air particulate matter material
for use in reference materials.
AB - A contemporary PM2.5 (particulate matter smaller than 2.5 microns aerodynamic
diameter) aerosol material from an urban site has been collected for the
production of a new standard reference material that will be made available for
the development of new PM2.5 air quality standards. Air particulate matter
corresponding to the PM2.5 fraction was collected at an established Environmental
Protection Agency monitoring site in Baltimore, Maryland. The air-sampling system
that has been constructed for this collection separates fine particles with a
cyclone separator and deposits them onto an array of Teflon membrane filters. The
fine air particulate material is removed by ultrasonication or by mechanical
means and collected for further preparation of standards. The composition of the
collected PM2.5 aerosol, as well as the composition of the deposited PM2.5
aerosol, are determined by instrumental nuclear activation analysis and other
techniques.
PMID- 10676494
TI - Determination of concentrations of elements in the atmospheric aerosol of the
urban and rural areas of Beijing in winter.
AB - The proton-induced X-ray emission technique is one of the most suitable methods
in the study of the multielement content of atmospheric aerosols. Atmospheric
aerosol samples were collected in winter using an eight-stage cascade impactor at
a site of the urban center and a rural site of Beijing. The aerosol samples
collected were analyzed to determine maximum, minimum, and average concentrations
of up to 20 elements and the ratios of the average element concentrations for the
coarse to fine particles (C/F) by the PIXE technique. It has been found that the
average elemental concentrations in the urban center are higher than those in the
rural area, except S and Br. The concentrations for S and Pb in the atmospheric
aerosols are found to be less than the results of previous measurement, but their
concentrations in the fine particles increased in winter in the samples from the
urban center. The deposition probability of the International Commission on
Radiological Protection (ICRP) mode and the mass particle-size distributions of
the elements determined in the urban center have been utilized to evaluate
inhalable particulate matter fractions retained in the three regions of one's
respiratory tract and their harm to human health is discussed.
PMID- 10676495
TI - Content of trace elements in the respirable fractions of the air particulate of
urban and rural areas monitored by neutron activation analysis.
AB - The concentrations (ng/m3) of more than 30 trace elements have been determined in
the total air particulate matter and in the size-segregated fractions collected
in urban, industrialized, and rural residential areas in northern Italy by means
of a multistage inertial impactor with the PM10 inlet. All measurements have been
carried out by instrumental neutron activation analysis, except for Pb and Cd,
which have been determined by electrothermal atomic absorption spectroscopy.
Analytical quality assurance procedures have been developed with special regard
to blanks, reagents, and sampling. Total concentrations and the granulometric
distribution found in the different locations are reported and compared.
PMID- 10676496
TI - Measurement of PM10/2.5 fractionated respirable particles in urban Toronto by
INAA, PIXE, ICP-AES, and LAMS. A comparison.
AB - The chemical analysis of urban Toronto airborne particulate matter (PM), size
segregated into respirable PM10/2.5, is presented. The characterization of PM by
use of proton-induced X-ray emission analysis (PIXE), and inductively coupled
plasma-atomic emission spectrometry revealed elemental information; a newer laser
ablation-ionization mass spectrometry approach has the potential to expand the
chemical information from PM by analyzing both the inorganic and organic species.
These PM analytical approaches will be continued in the future for studying (1)
emission source identification, (2) inhalation health hazards, and (3) urban smog
chemistry.
PMID- 10676497
TI - INAA and PIXE of atmospheric and combustion aerosols.
AB - Using instrumental neutron activation analyses and photon-induced x-ray emission
techniques for analysis of size-fractionated atmospheric and combustion aerosols
and other emission samples arising from fluidized-bed combustion of North
Bohemian lignites up to 42 elements were determined in all samples types. This
allowed the evaluation of element enrichment, time trends, and inter-element
correlations and the performance of factor analysis of various fractions of
atmospheric aerosols. The data obtained on mass and element size distributions of
aerosols and emission samples obtained upon lignite combustion in an experimental
scale atmospheric fluidized-bed combustor without and with added hydrated lime
and limestone were used to elucidate the mechanism of abatement of toxic trace
and matrix elements from flue gas.
PMID- 10676498
TI - An evaluation of atmospheric deposition of trace elements into the Great Lakes.
AB - High-volume air samplers were used to collect aerosol samples on Whatman 41 air
filters at the Canadian air sampling stations Burnt Island, Egbert, and Point
Petre. Once collected, the samples were analyzed for trace elements by neutron
activation analysis. Air concentrations of over 30 trace elements were
determined. A special focus was made to utilize Compton suppression gamma-ray
spectroscopy and epithermal irradiations to enhance the detection limits of
neutron activation analysis. These techniques allowed for the determination of
trace elements at very low levels. Results of the study of the trace-metal dry
deposition into Lakes Huron and Ontario indicated that the majority of the total
deposition resulted from crustal materials. However, dry deposition is also a
significant pathway for many toxic anthropogenic trace metals into the Great
Lakes.
PMID- 10676499
TI - Biomonitoring of air pollution as exemplified by recent IAEA programs.
AB - Biomonitoring is an appropriate tool for assessing the levels of atmospheric
pollution, having several advantages compared with the use of direct measurements
of contaminants (e.g., in airborne particulate matter, atmospheric deposition,
precipitation), related primarily to the permanent and common occurrence of the
chosen organisms in the field, the ease of sampling, and trace element
accumulation. Furthermore, biomonitors may provide a measure of integrated
exposure over an extended period of time and are present in remote areas and no
expensive technical equipment is involved in collecting them. They accumulate
contaminants over the exposure time and concentrate them, thus facilitating
analytical measurements. Based on large-scale biomonitoring surveys, polluted
areas can be identified, and by applying appropriate statistical tools,
information can be obtained on the type of pollution sources and on the
transboundary transport of atmospheric pollutants. The International Atomic
Energy Agency is including the research on biomonitors in its projects on health
related environmental studies. Biomonitoring activities from several coordinated
research projects on air pollution are presented, and results from an
international workshop are discussed. In addition, activities in supporting
improvement quality in the participating laboratories are outlined.
PMID- 10676500
TI - Study on air pollution in Beijing's major industrial areas using multielements in
biomonitors and NAA techniques.
AB - Three kinds of plant leaves, Chinese white aspen, arborvitae, and pine needles,
have been sampled from the Yanshan Oil refinery complex, the Capital Iron and
Steel Factory, and Badachu, a control area in Beijing, as biomonitors for air
pollution studies. Each sample was divided into two parts, washed, and unwashed.
Thirty-one trace elements (As, Au, Br, Ca, Cd, K, La, Lu, Mo, Na, Sb, Sm, U, W,
Yb, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, Rb, Sc, Se, Sr, Ta, Tb, Th, and Zn) have
been determined by using the relative and the K0 methods of instrumental neutron
activation analysis (NAA) techniques. The results indicated the following: (1)
The concentration of trace elements in unwashed samples are much higher than
these in washed samples; (2) the area around Capital Iron and Steel Factory is
heavily polluted, and the Yanshan Oil refinery complex area is moderately
polluted; (3) Chinese white aspen is a good biomonitor in particular seasons and
pine needles are better than arborvitae for yearly monitoring; (4) elements As,
Cd, Hg, Co, Rb, Sb, W, and Zn are highly absorbed by Chinese white aspen. Pine
needles are sensitive for the absorption the elements Br, Cr, Cd, Fe, Sc, Cs and
rare earth elements, but arborvitae is very sensitive for the absorption of Sr.
PMID- 10676501
TI - Environmental assessment in an industrial area of Portugal.
AB - The region of Lisbon and south of Lisbon (Sado estuary) is densely
industrialized, and, therefore, air pollution should be studied in a more
detailed scale there. The topography of the Sado estuary region and the
predominant wind direction from the northwest contribute to the influence in this
region of the industries located in the north. The region selected includes a
fuel-fired power station. Transplants of the lichen Parmelia sulcata Taylor were
suspended in nylon bags within a rectangle 15 km wide and 25 km long on a grid
2.5 km x 2.5 km, centered in the power station. In each of the 47 sites, 2 sets
of 4 transplants each were hung. Care was taken (1) in covering the two sets with
a polyethylene roof to prevent leaching of elements in the lichen, (2) in
building a hanging system that could rotate according to the wind direction, and
(3) in orienting one set toward the wind and the other set opposite the wind. For
a 1-yr period and every 3 mo, one transplant of each set is collected. In this
work, the results of the first campaign (after 3 mo suspension) obtained by
instrumental neutron activation analysis and proton-induced X-ray emission are
shown. Some elemental contents are mapped and discussed.
PMID- 10676502
TI - Determinations of subnanomole elemental levels by NAA and their possible impact
on human health related issues.
AB - Neutron activation analysis (NAA) is an appropriate tool for the determination of
trace elements in biological systems. The virtually blank-free NAA procedures
fittingly complement precautions employed in sampling and sample preparation of
biological matrices. Results from instrumental NAA procedures used to establish
baseline values and time trends for elements in human tissues demonstrate the
advantages as well as the limits of these procedures for nanomole and, in a
considerable number of instances, subnanomole elemental levels. In addition,
subnanomole mass fractions have been determined with extremely low limits of
detection by employing NAA with radiochemical separations isolating very low
levels of radioactivity from the matrix background. The elements reviewed in this
article include Cr, Se, Pt, and others that have been determined by NAA at
subnanomole levels in human tissues and body fluids and in biological
macromolecules.
PMID- 10676503
TI - Evaluation of trace elements in lung samples from coal miners using neutron
activation analysis.
AB - In this study, instrumental neutron activation analysis was applied to the
determination of Sc, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Th, and U in lung
samples from miners working in coal mines located in the state of Santa Catarina,
Brazil. These results were compared to those from a control group constituted of
healthy individuals. The results showed that the elements determined exhibit
considerable intersubject variability within a single group of individuals and
the mean values of concentrations in miners' lungs were higher than those of
normal individuals. Lung samples presented U concentrations varying from 11 to
890 micrograms/kg. Therefore, for some samples, the contribution of the uranium
fission products in the analysis of La, Ce, Nd, and Sm was considered by
determining the interference correction factors. The accuracy of the results was
evaluated by analyzing certified reference materials.
PMID- 10676504
TI - Environmental control in the uranium mine Lagoa Real, Brazil.
AB - Uranium production in Brazil will be restarted in the year 2000, through
exploration of the Jazida da Cachoeira, located in the uraniferous region of
Lagoa Real, Bahia State, northeast Brazil. Because of the mining operations, an
open cast mine of approximately 27 x 10(4) m2 will be produced and the material
removed will constitute approximately 14 x 10(6) tons, occupying an estimated
area of 50 x 10(4) m2. Currently, there is a new concept about project
developing, where the impact assessment is addressed during the initial phases.
Beside this, legislation requires an environmental impact assessment before
starting mining activities. In this context purpose, it is the purpose of this
work to evaluate the chemical composition of the future waste; thus, samples were
collected from the rocks that surround the mineral deposits. Instrumental neutron
activation analysis was used for the elemental quantification, the mean elemental
concentrations were calculated, and the ratios were normalized using North
American Shale Composite (NASC). In the raw material eight main mineral
structures exist whose elementary composition were compared using the statistical
techniques of analysis of variance, ranking ANOVA, and multivariate ANOVA.
PMID- 10676505
TI - Comparative study of desert truffles from Kuwait and other countries in the
Middle East for radionuclide concentration.
AB - Concentrations of some radionuclides, including 137Cs, in desert truffles in
Kuwait were studied and compared with similar samples from other countries in the
Middle East, namely Iran, Egypt, and Tunisia. In addition, sand samples from
Kuwait were assayed to calculate the transfer factor of the radionuclides under
consideration. The measured concentrations of 40K, 226Ra, and 137Cs show that
137Cs is much higher in Egyptian samples, whereas 40K is much lower in samples
from Tunisia. The average effective dose equivalent calculated for the Kuwaiti
population according to their diet habits was found to be in the range 0.14-0.23
microSv/a. The results are compared with values from other countries.
PMID- 10676506
TI - Study of environmental biomonitoring of the Jiaozhou Bay.
AB - The content of 34 elements was determined in tissue samples of several marine
bivalve species collected from various sites in the Jiaozhou Bay. The scope of
the study was to determine the most suitable bivalve species to be used for
environmental biomonitoring and to evaluate the environmental status of the bay.
Clams exhibited higher elemental contents than oysters and they are the major
marine bivalve species in the Jiaozhou Bay; therefore, we consider clams to be
more suitable than oysters as bioindicators for evaluating the environmental
status of the area. Increased elemental levels in clam tissues indicate polluted
sites. Also, increased elemental levels in mussels point to possible pollution
from tourism development at one selected site.
PMID- 10676507
TI - Measurement of fluorine pollutant in plant leaves and soil using nuclear reaction
analysis.
AB - In this article, the soil and the leaves of plants, parasol, cotton, and glossy
privet around a fluorine-polluted area were taken as the samples, and fluorine
concentration of the samples were studied using the nuclear reaction 19F(P,
alpha)16O, and some results were given.
PMID- 10676508
TI - Multielement compositions of marine phytoplankton samples from coastal areas of
Japan by instrumental neutron activation analysis.
AB - Phytoplankton samples were collected during spring bloom of diatoms from three
coastal areas of Japan using a NORPAC P-25 net (25-micron opening) with a NGG52
prenet (335-micron opening), and 25 major and trace elements have been analyzed
by INAA. Concentration ranges of analyzed phytoplankton samples are much wider
than the concentration ranges compiled by Bowen (1979) except for As, and data of
marine phytoplankton samples for Br, Sb, Hf, Sc, La, Ce, Sm, and Eu were not
included in the compilation. The 25 analyzed elements have been categorized into
three groups: elements showing positive correlation with Br, positive correlation
with Al, and no positive correlation with Br or Al. The marine phytoplankton
samples have been plotted on a Masuzawa-Koyama-Terazaki (MKT) plot and it proved
that the MKT plot is applicable to marine phytoplankton samples.
PMID- 10676509
TI - Neutron activation analysis of Se in bovine plasma samples.
AB - Elemental concentration of selenium in bovine plasma at parts-per-billion levels
was determined using radiochemical neutron activation analysis (RNAA). This study
was connected with the relation between the Enteque Seco, a toxic bovine
calcinosis, and the Se status. The technique developed is based on the
coprecipitation of Se with HgS. Good agreement with certified reference materials
have been found. The values for the Se contents in normal bovine samples were in
concordance with literature values.
PMID- 10676510
TI - Plutonium, 241Am, 90Sr, and 137Cs concentrations in some Antarctic matrices.
AB - A radioecological survey in Antarctica shows that the 239 + 240Pu, 238Pu, 241Am,
90Sr, and 137Cs activities were detectable in nearly all the samples. The
activity level of 239 + 240Pu, 241Am, and 137Cs in antarctic sediments was about
5-20 times lower than in the northern Adriatic Sea sediments, but the 238Pu
activities were relatively high. It was interesting to note that the 90Sr
concentrations in all the sediments tended to be low, which could be the result
of the easier exchangeable behavior of 90Sr in water. High concentrations were
detected in mosses and lichens and their activity levels were comparable to those
in central Italy. The radionuclide ratio analyses show that the major part of 239
+ 240Pu, 241Am, 90Sr, and 137Cs was a result of nuclear weapon tests. The higher
241Am/239 + 240Pu ratio was observed and it could perhaps be the result of
fallout of nuclear weapon tests prior to 1962. The 238Pu/239 + 240Pu ratio in the
antarctic matrices was about seven times higher than in the Northern hemisphere
and it could be inferred that the major part of 238Pu was originating from the
SNAP-9A satellite accident.
PMID- 10676511
TI - Bioaccumulation of rare earth elements in cultured HeLa cells.
AB - HeLa S-3 cells were grown in minimal essential medium supplemented with 10% calf
serum and 1 mM L-glutamine without adding any rare earth elements (REEs).
Exponentially growing cells were collected, and dried materials were used to
analyze their REE content by inductively coupled plasma-mass spectrometry. The
results showed that the cells accumulated REEs in individually different manners;
namely the accumulation ratio was higher in the lighter REEs than in the heavier
REEs. To deduce the implication of the accumulation of REEs in HeLa cells, the
accumulation ratios for REEs were compared with those of other biologically
important elements. It was seen that the accumulation ratios obtained for REEs
(from 31.8 [Ce] to 14.7 [Lu]) were intermediate among those of many bioelements:
Fe (124), Mg (54.5), K (38.8), Cr (12.7), Na (11.8), Mn (11.3), Zn (10.7), Ca
(8.8), and V (6.7).
PMID- 10676512
TI - Elemental analysis of herbal preparations for traditional medicines by neutron
activation analysis with the k0 standardization method.
AB - Medicinal herb preparations prescribed for specific treatment purposes were
purchased from markets and were analyzed by instrumental neutron activation
analysis with k0 standardization. Then, 500-700 mg of each sample was pelletized
under a pressure of six tones and irradiated together with monitors for alpha and
neutron flux ratio determinations for about 6 h in a thermal flux of 2.29 x
10(12) n/cm2/s. The accuracy of the method was established by analyzing standard
reference materials. Twenty-nine elements, Ag, As, Au, Ba, Br, Ca, Ce, Co, Cr,
Cs, Eu, Fe, Hf, K, La, Mn, Mo, Na, Rb, Sb, Sc, Se, Sm, Sr, Th, U, Yb, and Zn,
were measured in all the samples, and Hg was detected in some samples, with good
accuracy and reproducibility. The concentration of elements determined was found
to vary depending on the composition of the herbs used. Although the trend
linking the element of the medicinal plants to its curative abilities could not
be clearly determined, this study showed that the toxic elements found in the
samples were below the levels prescribed by health regulations. Nevertheless,
such data are important to understand the pharmacological action and the exact
mechanisms of action and formation of active constituents for each medicinal
plant and to decide the dosage of the herbs used in the final formulation.
PMID- 10676513
TI - Determination of selenium in Canadian food items by cyclic instrumental neutron
activation analysis.
AB - Instrumental neutron activation analysis (INAA) and pseudocyclic INAA (PCINAA)
have been used to determine the selenium content of a variety of Canadian food
items. Use of the 162-keV gamma ray of short-lived 77mSe in INAA allowed
relatively simple and rapid determinations and was suitable for many of the
foods. PCINAA was found to give lower detection limits and was used for the low
selenium food samples. Both internal and external quality assessments were used
to evaluate and assure the accuracy and precision of the methods developed.
PMID- 10676514
TI - Lead and copper contamination of soil from industrial activities and firing
ranges.
AB - Lead still remains one of the most thoroughly investigated heavy metals in the
environment. Although the identification of lead in soil is a routine matter, its
environmental consequence is still much debated because of its potential
mobility. We have investigated lead- and copper-contaminated soil from two
different areas. One was in an urban area, which formerly had a lead smelter
within the city. The other a firing range, in which hundreds of thousands of
rounds were fired into a very large mound known as a berm. Homogeneity tests,
depth profiles, and Pb-Cu correlations are discussed.
PMID- 10676515
TI - Radiochemical neutron activation analysis in the life sciences. A look back and
ahead.
AB - The contribution of radiochemical neutron activation analysis (RCNAA) to a better
understanding of trace element analytics and physiology in the life sciences is
outlined. Now, various non-nuclear powerful techniques for trace element analysis
have become available, competing with RCNAA. This necessitates re-evaluation of
the position of RCNAA, in particular versus inductively coupled plasma--mass
spectrometry (ICP-MS). On basis of the characteristic features of RCNAA and the
capabilities of various competing non-nuclear analytical techniques, future
niches for RCNAA in the analytical market are indicated.
PMID- 10676516
TI - Prompt gamma-ray analysis using cold and thermal guided neutron beams at JAERI.
AB - A highly sensitive neutron-induced prompt gamma-ray analysis (PGA) system, usable
at both cold and thermal neutron beam guides of JRR-3M, has been constructed. The
system was designed to achieve the lowest gamma-ray background by using lithium
fluoride tiles as neutron shielding, by placing the samples in a He atmosphere
and by using a Ge-bismuth germanate detector system for Compton suppression. The
gamma-ray spectrometer can acquire three modes of spectra simultaneously: single,
Compton suppression, and pair modes. Because of the low-energy guided neutron
beams and the low-background system, analytical sensitivities and detection
limits better than those in usual PGA systems have been achieved. Boron and
multielemental determination by a comparative standardization have been
investigated, and accuracy, precision, and detection limits for the elements in
various materials were evaluated. The system has been applied to the
determination of B and multielements in samples of various fields such as
medical, environmental, and geological sciences.
PMID- 10676517
TI - Is loss-free counting under statistical control?
AB - A new formula for the statistical uncertainty of "loss-free counting" (LFC) is
presented. Its validity is demonstrated by comparing with experimental data
obtained with a HPGe gamma-ray spectrometer. Also, computer simulation data of
nuclear counting with different types of count loss (pileup rejection, extending
and nonextending dead time) are in agreement with the predicted counting
uncertainty. The proposed formula for LFC uncertainty is applicable to
spectrometers with a classical semi-Gaussian pulse-shaping amplifier as well as
with a gated-integrator amplifier. Hence, achieving statistical control seems to
be a feasible goal.
PMID- 10676518
TI - Limits of detection of a total reflection X-ray fluorescence system with double
reflection module.
AB - An X-ray tube with a Mo target and Zr filter, operated at 45 kV/20 mA, was used
to excite samples (5 microL deposited on a quartz support) and the total
reflection angle condition was obtained with a double reflector module built with
two 10-cm-long 7-mm-thick quartz crystals placed 50 microns apart. A high
resolution spectrometer based on a Si(Li) detector coupled to a multichannel
analyzer was used for X-ray detection and the spectra were interpreted with the
AXIL software. The system was calibrated with standard chemical solutions
containing Cr, Fe, Cu, Zn, and Pb, and Y was used as an internal standard to
correct eventual geometric errors and high-voltage instabilities of the X-ray
generator. The limits of detection were 19, 9, 5, and 4 ng/mL for Cr, Fe, Cu, and
Zn, respectively, analyzed through characteristic K alpha X-rays, and 7 ng/mL for
Pb, through L alpha X-rays, considering 50 microL samples deposited and dried on
a quartz support, to be excited/detected for 1000 s.
PMID- 10676519
TI - Matrix effects in PIXE analysis of aerosols and ashes.
AB - A comparison of instrumental neutron activation analysis (INAA) and proton
induced X-ray emission (PIXE) results for size-fractionated atmospheric aerosols
("coarse" and "fine" fractions with an equivalent aerodynamic diameter of 2-10
microns and < 2 microns, respectively, or the PM10 fraction) showed that PIXE
yielded significantly lower results for the PM10 and coarse fractions, especially
for elements with a low Z resulting from a particle size effect. Somewhat lower
PIXE results were also obtained for the fine fraction of atmospheric aerosols. A
correction is also needed for irregularly shaped deposits of combustion aerosols
collected by a cascade impactor in 11 size fractions ranging from 0.016 to 14.3
microns, as well as for thick samples of fly and bottom ashes. An equivalent
layer thickness (ELT) model is proposed to correct the matrix effects in PIXE.
The approaches for the calculation of ELT using a comparison of PIXE and INAA
results or by comparing PIXE results obtained using two different incident proton
beam energies (1.31 and 2.35 MeV) are described. The correction for the ash
pellets and irregular deposits are also discussed.
PMID- 10676520
TI - Comparison of the relative and k0 methods for the standardization of NAA with
stable low-flux reactors.
AB - The k0 standardization method was adapted for NAA with stable low-flux reactors
where flux monitors are not needed. The modified k0 method offers the convenience
of the use of libraries of sensitivity constants. It was compared to the relative
method for 52 elements using a SLOWPOKE reactor and 6 counting geometries. The
sensitivity constants determined from k0 values were found to be as accurate or
more accurate than those measured with standards. NAA with this modified k0
method should be accurate to 3% for light elements and 5% for heavy elements.
PMID- 10676521
TI - An evaluation of thermal and epithermal neutron activation analysis compton
suppression methods for biological reference materials.
AB - For neutron activation analysis (NAA), the usual matrix problems of sodium,
chlorine, and bromine are well known to give rise to high backgrounds that
inhibit the determination of several trace elements for short-lived or medium
lived NAA. For long counting times in long-lived NAA, very low backgrounds are
required to achieve good sensitivities. We have investigated the use of thermal
and epithermal NAA in conjunction with Compton suppression to determine several
elements such as arsenic, antimony, cadmium, and mercury, at the level of a few
nanograms. The values of these techniques are discussed in contrast to the
standard radiochemical methods.
PMID- 10676522
TI - Determination of iodide amounts in urine and water by isotope dilution analysis.
AB - Urinary iodide and iodine in drinking water were determined in 318 healthy
children aged 0 to 18 yr living in Izmir and environmental rural and urban areas
in the western part of Turkey. The method is based on substochiometric isotope
dilution analysis. Iodide was precipitated by substoichiometric amounts of AgNO3.
Iodide-131 was used as a tracer. Electrophoresis was performed to separate Ag131I
from excess 131I-. The Ag131I zone was cut off the electrophoresis paper and
counted with a NaI(Tl) scintillation counter. Count rates were plotted versus
added KI concentrations. The unknown iodide amount was found by using these
linear plots. Iodide concentration ranges were within 1.8-100.45 micrograms/L in
the analyzed drinking water samples. The mean value was 44.14 +/- 17.33
micrograms/L and the median was 58.08 micrograms/L. Urinary iodide concentration
ranges were 0.22-142.22 micrograms/L. The median of the distribution was 37.71
micrograms/L and the mean was 40.30 +/- 24.05 micrograms/L. The results show that
the examined area suffers moderate iodine deficiency.
PMID- 10676523
TI - On the fission interference correction and its dependence on the epithermal to
thermal neutron flux ratio in thermal NAA of molybdenum.
AB - The present work aims at the following: (1) analyzing the experimental fission
interference factor for molybdenum, FMo, obtained by the authors, who have
described the irradiation conditions used as concerns the epithermal to thermal
neutron flux ratio, phi epi/phi 0; (2) establishing a simple calculation model
that describes the dependence of FMo on phi epi/phi 0 in an adequate way, to
provide a satisfactory basis to explain the scatter found in the existing
experimental data; and (3) clearly indicating the basic recommendations to take
into account in order to obtain with high accuracy the concentration of
molybdenum in samples containing uranium.
PMID- 10676524
TI - Effects of reactor temperature and sample mass on the activation of biological
and geological materials with a SLOWPOKE reactor.
AB - Neutron activation analysis with a SLOWPOKE reactor relies on the stability of
the neutron flux in the irradiation sites. Flux monitors were irradiated to
measure the flux variation with the reactor temperature and with the amount of
moderator in the irradiation vial. The thermal flux decreased by 2.7% for a 10
degrees C increase in reactor temperature. The thermal flux increased by up to 8%
and the fast flux decreased by up to 13% depending on sample size and hydrogen
content.
PMID- 10676525
TI - Direct preparation of radioactive fullerenes as a tracer for applications.
AB - The C60 and C70 fullerenes were irradiated by high-energy gamma-rays and charged
particles. The irradiated samples were dissolved in CS2 and/or toluene and
filtered to remove insoluble by-products. Finally, radioactive fullerenes and
products labeled with 11C or 13N were isolated and detected in the liquid phase
by radiochromatography. It was found that (1) not only 11C or 13N radioactive
monomer fullerenes but also their dimers (trimers and, possibly, tetramers) were
produced by recoil implantation process following nuclear reaction and (2) the
radioactive fullerene labeled with 11C yields has led to high yields.
PMID- 10676526
TI - Effect of air cavities on the dose delivered to the lung during high-dose
brachytherapy.
AB - In the treatment of lung cancer using the radiotherapy technique of intracavitary
brachytherapy with an 192Ir source, the lung is normally assumed to be entirely
composed of a homogeneous mass of soft tissue. The aim of this study is to
investigate whether there is the possibility that the air cavities in the lung
influence the dose delivered to the lung at a prescribed distance from the
source. The Monte Carlo code MCNP-4A was used to model the dose delivered by both
192Ir and 198Au as a function of treatment medium, density and composition,
photon energy, and distance from the source. The suitability of MCNP-4A for this
study was tested by producing depth-dose profiles for photons in water and
comparing these to calculated profiles produced using well-documented methods.
PMID- 10676527
TI - Tritium incorporation into functional materials by applying OT-for-OH exchange
reaction.
AB - In order to reveal (1) the behavior of the tritium-labeled hydroxyl group (i.e.,
OT group) and (2) the effect of temperature on the dissociation equilibrium of
tritiated water, the OT-for-OH exchange reaction in a homogeneous system was
observed (1) using ion-exchange resins and HTO water, and (2) using hydrogen
oxides and HTO water. Consequently, the following four conclusions were obtained:
(1) The OT-for-OH exchange reaction occurred between each anion-exchange resin
(or each metal hydroxide) and HTO water. (2) The higher the temperature is, the
smaller the activity of both anion-exchange resin and metal hydroxide will be,
and the activity of cation-exchange resin is large when the temperature is high.
(3) The larger the degree of crosslinking in each Biorad AG1 resin is, the lower
the activity of the resin will be. (4) The exchange rate for the OT-for-OH
exchange reaction is small when the electronegativity of the metal ion in the
metal hydroxide is large.
PMID- 10676528
TI - Experience on the neutron activation of natural/enriched Re, Sm, and Ho nuclides
in a reactor for the production of radiotherapeutic radionuclides.
AB - In recent years, much effort has been concentrated on the use of beta-emitting
radionuclides for the treatment of various cancers. The reports suggested the
application of 186Re and 153Sm as radiotherapeutic radionuclides for the
treatment of palliative widespread skeletal metastases, whereas 166Ho was
suggested as an agent for radiation synovectomy. Hence, a study on the production
of 186Re, 153Sm, and 166Ho radionuclides was carried out by neutron activation of
the appropriate target materials using a Pakistan Atomic Research Reactor (PARR
1) at a neutrons flux of 1 x 10(4) n/cm2 s. These radionuclides were then
converted to appropriate radiopharmaceuticals for their use on animals and
patients. The targets of natural Re (metal), natural Sm2O3, enriched Sm2O3
(99.06%), Sm(NO3)3 (solid), Sm(NO3)3 (liquid), and Ho2O3 were irradiated in the
PARR-1. After irradiation, the purity of these radionuclides were checked by a
multichannel analyzer, Canberra series 85 (MCA) coupled with HPGe detector and
then measured in radioisotope calibrator Capintec ionization chamber model CRC
5RH. The effect of the irradiation time and amount of target material was
investigated on the production yields of the radionuclides. The results showed an
increase in the specific activity of Re with an increase in the irradiation time
from 1 to 72 h, whereas a decrease in the specific activity was observed with
increase in the amount of Re from 10 to 100 mg. Similar results were obtained for
153Sm and 166Ho radionuclides. The results further indicated that the specific
activity of powder target was much less than the liquid targets for 153Sm. Their
conversion to the appropriate radiotherapeutic radiopharmaceuticals were also
carried out by investigating the experimental conditions and acceptable quality
of 186Re-HEDP and 153Sm-EDTMP complexes were prepared. These complexes were then
used on animals and patients which showed good performance.
PMID- 10676529
TI - Determination of trace elements in porcine brain by inductively coupled plasma
mass spectrometry, electrothermal atomic absorption spectrometry, and
instrumental neutron activation analysis.
AB - Methods have been developed for the analyses of trace metals in various areas of
porcine brains, (temporal, parietal, frontal cortex, both right and left
hemispheres). Determinations were carried out using inductively coupled plasma
mass spectrometry (ICP-MS) and electrothermal atomic absorption spectrometry
(ETAAS). The elements investigated were Li, Mn, Cu, Zn, Cd, Hg, and Pb by ICP-MS
and Cu, Cd, and Mn by ETAAS. For determination by ICP-MS, a method of standard
additions calibration coupled with internal standards was used, and for ETAAS,
standard additions calibrations were prepared. The accuracy of all methods was
determined using NIST and IAEA certified reference material. A small number of
pig brains were analyzed by instrumental neutron activation analysis for Cr, Co,
Cs, Fe, Rb, Se, Sc, Sb, and Zn using the comparator method of analysis. Four
separate NIST standard reference materials have been used to examine the validity
of the comparator method.
PMID- 10676530
TI - A comparative study in Alzheimer's and normal brains of trace element
distribution using PIXE and INA analyses and glucose metabolism by positron
emission tomography.
AB - The onset of Alzheimer's disease has been shown to affect trace element
concentrations in the brain when compared to "normal" subjects in ex vivo
samples. The techniques used to determine trace element concentrations were
proton-induced X-ray emission and instrumental neutron activation analysis. With
these methods, significant differences are seen between lobes within a hemisphere
and between the same lobes of opposing hemispheres for "normal" brains. The
change observed in trace element concentrations may indicate a possible
alteration in the function of the blood-brain barrier, the effect of which can be
investigated in vivo using the imaging technique of positron emission tomography
(PET). A PET study was performed on nine female and nine male subjects to
determine whether the regional metabolic rate of glucose (rCMRGlu) varied between
hemispheres and sex in the Alzheimer diseased brain as was seen in the trace
element study. Glucose metabolism was measured using [F-18]-fluorodeoxyglucose
(18F-FDG). Hemispherical differences were observed for the frontal, occipital,
parietal lobes, and the temporolateral region in both males and females for
rCMRGlu. Variation was also seen between sexes, where the frontal lobe had a
lower rCMRGlu in females compared to that of males.
PMID- 10676531
TI - Accumulated experience with prenatal diagnosis of Menkes disease by neutron
activation analysis of chorionic villi specimens.
AB - Since 1983, prenatal diagnosis of Menkes disease has been carried out by
determining Cu in samples of chorionic villi from the fetus by means of
radiochemical neutron activation analysis. Concentrations of Cu in chorionic
villi from male fetuses later confirmed to have Menkes disease were invariably
higher than previously reported values for normal controls. Out of 240 samples
analyzed in the period 1983-1998, there were 71 from female fetuses that could be
carriers of the Menkes genetic defect without suffering from the disease.
Increased concentrations of Cu in these samples could not be attributed to the
presence of this genetic defect, but might result from sporadic contamination of
the samples before analysis. Such contamination also may occur in samples from
male fetuses and thus raise the level of Cu in small, but normal specimens into
the range characteristic of Menkes disease. In spite of a strict protocol for
taking samples without contamination, a total of four false positives were
reported during the period of investigation; no false negatives have occurred.
PMID- 10676532
TI - INAA of trace elements in colorectal cancer patients.
AB - The concentration of trace elements in samples of both colorectal cancer tumors
and normal tissues of a Mexican population were irradiated for 30 s and 4 h and
their elemental content were measured by instrumental neutron activation
analysis. Ca, Cu, Co, I, Mg, Se, Fe, Zn, Hg, Ba, and Cr were analyzed.
Alterations in Co, Fe, I, and Ba were found in tumors with respect to normal
tissues.
PMID- 10676533
TI - Determination of trace elements in tissue of human uterine cancer by instrumental
neutron activation analysis.
AB - In this article, the low-temperature freeze-drying pretreated technique and
instrumental neutron activation analysis were used to determine 29 trace elements
in samples of human uterine cancer tissue. The content of these trace elements in
uterine cancer tissue was compared with that in cervicitis tissue and in healthy
tissue, respectively. Preliminary results indicated that significant differences
in contents of Au, I, and Se were observed in these tissues.
PMID- 10676534
TI - Elemental composition changes between breast tissue with and without silicone gel
sheeting and hypertrophic scar tissue.
AB - Hypertrophic scars occur after dermal trauma and are characterized by being
elevated above normal skin level as a result of an abundance of collagen. The
application of silicone gel sheeting (SGS) has been found to be an effective
method of treatment, causing them to regress much quicker than they would do
naturally. Normal skin and hypertrophic scar tissue were characterized using
proton-induced X-ray emission (PIXE). Skin tissue that had been covered in SGS
was also analyzed. For each element and sample type, the concentrations in the
epidermis were plotted against the dermis. By considering the concentrations of
breast tissue with and without SGS, it could be seen if the SGS changed the
compositional structure of the skin. It was found that for the elements P, S, Cl,
and K the SGS has no effect on the structure of the skin, as both breast types
(with and without SGS) have regression lines that overlap. However, this work
shows that there are significant differences for P in the dermis and Cl in the
epidermis between the breast tissue with SGS and its control. Therefore, this
work shows that the effect the SGS has on concentration occurs similarly for both
the epidermis and dermis.
PMID- 10676535
TI - Cell-killing efficiency and number of platinum atoms binding to DNA, RNA, and
protein molecules of HeLa cells treated with combinations of hyperthermia and cis
diamine(glycolato)platinum(II).
AB - HeLa S-3 cells were treated with 195mPt-radiolabeled cis
diamine(glylato)platinum(II) (254-S) for 60 min at various temperatures, and the
relationship between the lethal effect and the number of Pt atoms binding to DNA,
RNA, and proteins was examined. The mean lethal concentration (D0) of 254-S for a
60-min treatment at 0 degree C, 25 degrees C, 37 degrees C, 40 degrees C, 42
degrees C, and 44 degrees C was 233, 132, 61.1, 42.7, 25.6, and 9.9 microM,
respectively. By using identically treated cells, the numbers of Pt atoms
combined with DNA, RNA, and protein molecules were determined in the subcellular
fractions. Thus, the D0 values given as drug concentrations were replaced with
the number of Pt atoms combined in each fraction. The, the cell-killing
efficiency of the Pt atom was expressed as the reciprocal of the number of Pt
atoms combined and was calculated for each molecule. The efficiency for the DNA
molecule was 0.61 x 10(4), 1.09 x 10(4), 1.88 x 10(4), 1.90 x 10(4), 2.66 x
10(4), and 5.88 x 10(4) nucleotides, respectively, for the conditions described.
From 0 degree C to 44 degrees C, the cell-killing efficiency of Pt atoms
increased by a factor of 9.6.
PMID- 10676536
TI - Determination of metallic ion transfer from an implanted prosthesis by the PIXE
method.
AB - Prostheses can release some metallic elements to the surrounding tissues,
particularly when they are not covered with a biomaterial layer and when an
unsealing process happens. We try to measure major and trace elements in these
tissues with an experimentally sensitive method. Proton-induced X-ray emission is
used to detect about 10 elements in tissue. Tissues are calcinated and deposited
in a thin layer before irradiation. Results are obtained in a standard and
samples from three patients. We observe contamination by Ti, Cr, Ni, and Zn in
the tissues. Correlations are to be studied between these atomic transfers and
prosthesis in the patient.
PMID- 10676537
TI - Hydrophilic crosslinked copolymers as tissue-equivalent materials for breast
cancer detection.
AB - Crosslinked hydrophilic copolymers have the potential to be used as breast
phantom materials because they can be made to have similar elemental composition
to that of body soft tissues. The copolymer, which consists of a combination of
hydrophobic monomers (methyl methacrylate [MMA]) and hydrophilic monomers
(vinylpyrolidone [VP]), have all the required major elements, such as hydrogen,
carbon, nitrogen, and oxygen, found in tissues. Photon attenuation measurements
were performed on the crosslinked hydrophilic copolymers in order to ascertain
whether they are good representatives of breast tissues in the photon energy
range of interest. The results of the measurements of transmission of photons by
the hydrophilic copolymers at different discrete energies between 10 and 60 keV
are presented.
PMID- 10676538
TI - Elemental analysis of blood of Nigerian hypertensive subjects.
AB - Proton-induced X-ray emission (PIXE) has been used to obtain the concentrations
of 11 elements (P, S, Cl, K, Ca, Fe, Cu, Zn, Br, Rb, and Cd) in whole-blood
samples of 16 hypertensive subjects (mean age: 52.5 +/- 0.5 yr) and 18 age
matched controls (mean age: 51.5 +/- 0.5 yr) in a Nigerian population. The
results of the study indicate that the hypertensive subjects have significantly
higher mean concentration of Cl, Cd, Cu, and Zn when compared with the controls,
and the mean concentration of P, K, and Ca was found to be significantly lower in
the hypertensive group in comparison to the controls. Furthermore, the Zn:Cd
ratio was found to be significantly higher in the controls than in the
hypertensives, and the Cu:Zn ratio was significantly higher in the hypertensives.
PMID- 10676539
TI - Determination of zinc contents in rabbits with cerebral ischemia by NAA and ICP
AES.
AB - Cerebral ischemia is an important cerebral vascular disease, and zinc is a
necessary trace element for humans. In this work, a cerebral ischemia model of
rabbit was established by operation. The samples of brain and serum in the animal
models were collected. The Zn contents in the samples were determined by neutron
activation analysis and inductively coupled plasma-atomic emission spectrometry.
The results show the Zn contents in brain decreased 2 mo after cerebral ischemia,
and Zn contents in serum decreased even more obviously. In addition, a positive
correlation of Zn contents between left and right cerebral hemispheres was
observed, and the positive correlation between brain and serum was also observed.
A test of Chinese medicine was also carried out in the work. Two Chinese
medicines were fed to rabbits with cerebral ischemia in the experiments. The
results showed they probably can prevent the decrease of Zn contents in serum.
PMID- 10676540
TI - Preliminary study on the relationship between osteoporosis and trace elements
with rat models.
AB - Thirty rats were divided randomly into five groups and fed with different feeds.
They were killed after 2 mo. Right thighs of these rats were taken as samples.
Bone mineral densities of these samples were measured by the double-energy x-ray
bone mineral densitometer, and trace elements contents of the samples were
analyzed by neutron activation analysis. Results of the experiments showed that
some elements were well correlated with others, and there were obvious variances
between some elements of the normal group and those of other four groups.
PMID- 10676541
TI - Study of implanted biomaterial functionality by diphosphonate molecules labeled
with radioactive 99mTc.
AB - An implanted biomaterial can be transformed into young bone after some months,
but it has not necessary reached full biofunctionality. Mineral concentration
kinetics and crystal-structure studies, still being carried out in our group, are
completed here by biofunctionality determinations. A natural coral is implanted
in vivo at the cortical level of the femoral diaphyoff++ in rabbits.
Diphosphonates molecules labeled with radioactive 99mTc are then injected in
rabbits and the fixation of the radioactivity is analyzed in several sites for 8
mo after the implantation. Nuclear instruments and methods are used for the
measurements. Four successive cycles of osseous remodeling are determined before
reaching a biofunctional phase.
PMID- 10676542
TI - Proximal impact of two first-grade preventive interventions on the early risk
behaviors for later substance abuse, depression, and antisocial behavior.
AB - We assessed the immediate effects of two universal, first-grade preventive
interventions on the proximal targets of poor achievement, concentration
problems, aggression, and shy behaviors, known early risk behaviors for later
substance use/abuse, affective disorder, and conduct disorder. The classroom
centered (CC) intervention was designed to reduce these early risk behaviors by
enhancing teachers' behavior management and instructional skills, whereas the
family-school partnership (FSP) intervention was aimed at improving parent
teacher communication and parental teaching and child behavior management
strategies. Over the course of first and second grades, the CC intervention
yielded the greatest degree of impact on its proximal targets, whereas the FSP's
impact was somewhat less. The effects were influenced by gender and by
preintervention levels of risk. Analyses of implementation measures demonstrated
that greater fidelity to the intervention protocols was associated with greater
impact on behavior ratings and on achievement scores, thus providing some
evidence of specificity in the effect of the interventions.
PMID- 10676543
TI - Personal resources and the social distribution of depression.
AB - This paper addresses the hypothesis that gender, age, marital status, and SES
matter for depression partly because of associated differences in the
availability and/or impact of the personal resources of mastery and self-esteem.
It is argued that findings indicating that the social distributions of these
resources complement those for depression would provide preliminary support for
this hypothesis. Based on a large urban community sample (n = 1,390), our
findings fail to support the availability hypothesis in relation to marital
status, provide only modest support in reference to age and gender, but yield
compelling support in relation to socioeconomic status (SES). Indeed, variations
in the availability of these resources, especially mastery, provide a largely, if
not entirely, adequate explanation for the SES-depressive symptoms relationship
and accounts for nearly half of the SES-Major Depressive Disorder relationship.
Although the significance of mastery was more pronounced among women and
unmarried persons, such differences did not contribute to understanding observed
gender or marital status variations in depression.
PMID- 10676544
TI - Principles for designing randomized preventive trials in mental health: an
emerging developmental epidemiology paradigm.
AB - An emerging population-based paradigm is now being used to guide the design of
preventive trials used to test developmental models. We discuss elements of the
designs of several ongoing randomized preventive trials involving reduction of
risk for children of divorce, for children who exhibit behavioral or learning
problems, and for children whose parents are being treated for depression. To
test developmental models using this paradigm, we introduce three classes of
design issues: design for prerandomization, design for intervention, and design
for postintervention. For each of these areas, we present quantitative results
from power calculations. Both scientific and cost implications of these power
calculations are discussed in terms of variation among subjects on
preintervention measures, unit of intervention, assignment, balancing, number of
pretest and posttest measures, and the examination of moderation effects.
PMID- 10676545
TI - Opening the black box: using process evaluation measures to assess implementation
and theory building.
AB - The past decade has seen increasing recognition in prevention science of the need
to move away from a black box approach to intervention evaluation and toward an
approach that can elaborate on the mechanisms through which changes in the
outcomes operate (Chen & Rossi, 1989; Durlak & Wells, 1997; Spoth et al., 1995).
An approach that examines issues of program implementation is particularly
critical in the design of efficacy studies of school-based preventive
interventions. Numerous preventive intervention strategies are now delivered
within the schools, often by regular classroom teachers. The extent to which
teachers faithfully deliver a particular curriculum or incorporate instructional
strategies emphasized by an intervention is a critical question for the overall
project evaluation. This article illustrates the utilization of process measures
from a multicomponent school-based prevention program to examine implementation
of a teaching staff development intervention, and the program's underlying
theoretical basis. Given the nested study design, the analyses utilize
hierarchical linear models (Bryk & Raudenbush, 1992) to examine changes in
teaching strategies by condition and investigate the hypothesized relationships
between teaching practices and student behaviors based on the program's
theoretical framework. Results suggest that teaching practices in two of the six
intervention focus areas were positively impacted in the first 18 months of the
project. Findings also support the relationships between teachers' instructional
practices and students' behavior.
PMID- 10676546
TI - Reflections on oncology in central and eastern Europe.
AB - In the last two decades cancer mortality dramatically increased in the majority
of Central and Eastern European countries. In the period from 1992 to 1995, the
Hungarian male population had the highest death rate (265.0 of 100,000) due to
malignancies among 46 countries worldwide. Hungarian women ranked third in cancer
death rate among these countries (138.0 of 100,000). Several factors might be
responsible for these figures: a) increases in environmental carcinogenic risk
factors, b) unfavourable lifestyle changes in the population especially related
to high tobacco consumption and dangerous drinking habits, c) lack or
insufficiency detection, d) delay in diagnosis, e) inadequate therapeutic patient
management, f) shortage of manpower, and g) unsatisfactory financial support.
Efforts have been made to overcome these difficulties by: a) detail analysis of
exogenous risk factors, b) review of lifestyle of the population, c) public
education efforts for effective prevention, d) introduction of model screening
programs, e) reorganization of cancer diagnosis and treatment services, and f)
design and establishment of a National Cancer Control Program.
PMID- 10676547
TI - The European Society for Medical Oncology (ESMO) and its activities through the
Central Eastern European Task Force.
AB - The article describes the history and organization of the European Society for
Medical Oncology. The society, founded in 1975, aims at advancing medical
oncology on a pan-European basis. Postgraduate training and education constitute
a major part of ESMO's activities through a current CME programme of courses and
other activities. Each year the ESMO Examination is held, and every other year
ESMO organizes its congresses with the latest attendance of more than 6000
delegates. ESMO has a continuous increase of members, also from outside Europe.
In 1996 ESMO created the Central Eastern European Programme with the aim to
support the needs of the countries of the former Eastern Europe. A task force
(CEE TF) with members from 16 Central Eastern European countries meets twice a
year to discuss key areas. An e-mail communication system has been launched,
courses are planned for 1998-1999, exchange programmes are in progress, and
support in setting up national guidelines will follow. A Central Eastern European
Oncology Group (CEE OG), which performs clinical trials on a cooperative basis,
has been established with ESMO guidance.
PMID- 10676548
TI - The pharmaceutical industry and oncology in central and eastern Europe.
AB - Major opportunities exist for patients, investigators and the pharmaceutical
industry in oncology drug development in Central and Eastern Europe. Novel
therapeutics may be offered for investigational use in selected centres capable
of adherence to Good Clinical Practice (GCP). Requirements for participation in
oncology clinical trials include the availability of experienced qualified
investigators highly motivated to conform with the principles of GCP
(International Harmonization (ICH) guidelines); availability of appropriate
Institutional Review Board for Human Subjects (IRB), access to appropriate
patient populations, access to individual patient data, acceptance of possible
audit by sponsoring companies and the Food and Drug Administration (FDA), and a
willingness to participate in the generation of new knowledge. Patients gain
through access to novel therapeutics. We have had success in performing clinical
trials to international standards in Central and Eastern Europe. This experience
will be described.
PMID- 10676549
TI - Progress in the non-Hodgkin's lymphomas.
PMID- 10676550
TI - Treatment of Hodgkin's disease: current strategies of the German Hodgkin's
Lymphoma Study Group.
AB - At present over 90% of early stage Hodgkin's disease patients will be cured. Both
radiotherapy and combination chemotherapy are effective treatment modalities.
However, the optimal choice of treatment or combinations of treatment is still
debated. Recently, several trials reported excellent treatment results with
combined modality in early stages of Hodgkin's disease. The use of chemotherapy
regimen not including alkylating agents may avoid the risk of infertility and
secondary malignancies and facilitates reduction of dose and field size of
radiotherapy in early stages. In intermediate stages new chemotherapy regimen
(i.e., BEACOPP) will offer the chance to reduce the fraction of patients with
initial treatment failure, while reducing the extent of radiotherapy. With the
introduction of the escalated BEACOPP regiment it was demonstrated that the
prognosis of the advanced stages could be positively influenced by
intensification of therapy. Future trials aim to answer: 1) which chemotherapy
regimen in which quantity will be the best with respect to efficacy and longterm
toxicity and 2) which dose and field size of radiotherapy is adequate within the
combined modality approach.
PMID- 10676551
TI - Multiple myeloma: an update on biology and treatment.
AB - Recently, several advances have been made in understanding the pathogenesis of
multiple myeloma. Increasing evidence favours a pre-switched, but somatically
mutated B-cell as myeloma stem cell to give rise to the malignant clone.
Deletions of the p53-gene, partial or total loss of chromosome 13 and
rearrangements of band 14q32 and 11q13 are frequently found in multiple myeloma,
and were shown to harbour prognostic significance. Presence or absence of
distinct chromosomal aberrations may guide selection of treatment strategies in
the future. Although melphalan/prednisolone remains the standard of myeloma
treatment in elderly patients, significant improvement has been achieved in
antimyeloma and in supportive therapy. High dose therapy with autologous stem
cell transplantation enhances survival in younger patients and several trials are
ongoing to substantiate these results. The effects of interferon maintenance
treatment on overall survival is significant in metaanalysis, although the gain
achieved is limited. Newer treatment strategies--targeting the molecular level-
have just entered clinical trials, and may further improve outcome of myeloma
patients.
PMID- 10676552
TI - Treatment of acute leukemia.
AB - Leukemic cells are highly sensitive to chemotherapeutic agents. A reduction of
the leukemic burden is easily achieved by chemotherapy in most cases. However, it
is difficult to reduce the number of leukemic cells to such an extent that a
regrowth does not occur and the patient is cured. Traditionally the therapy of
acute leukemia is divided into induction and post remission therapy. The aim of
the induction therapy is to reduce the number of leukemic cells to a
morphologically undetectable level allowing normal hemopoiesis to recover. The
goal of the post remission treatment is a further reduction of leukemic cells to
zero or to very low levels which can be controlled by (still unknown) endogenous
mechanisms. In some recent treatment protocols induction and the early part of
post remission treatment are not strictly separated.
PMID- 10676553
TI - Modulation of multidrug resistance (MDR) in hematological malignancies.
AB - The term multidrug resistance (MDR) describes the observation that tumour cell
lines can become cross-resistant to several structurally unrelated
chemotherapeutic agents after exposure to a single cytotoxic drug. In
hematological malignancies, MDR is most often associated with overexpression of P
gp, a 170-kd transmembrane glycoprotein encoded by the human MDRI gene. Indeed, P
gp expression has been correlated with drug sensitivity and clinical outcome in
several studies in acute myelogenous leukemia (AML), multiple myeloma (MM), and
malignant lymphomas (NHL). A large number of compounds 'off the shelf' have been
investigated for their ability to reverse the P-gp mediated MDR. However, most of
these agents produced severe toxic effects at doses required to effectively block
P-gp function, and modulation of P-gp in normal tissues can affect the
pharmacokinetics and, thus, the toxicity of the associated chemotherapeutic
agents. Phase I/IIa trials with third generation MDR modulators, such as
valspodar, show that these new agents can be safely administered in combination
with different chemotherapy regiments after dose adjustments of cytotoxic drugs
that a P-gp substrates. Moreover, MDR reversal by valspodar has been demonstrated
in the patients with AML, multiple myeloma, and non-Hodgkin's lymphoma. The
definition of the clinical benefits of using MDR modulators in haematological
malignancies and their full extent awaits the conclusion of the ongoing
randomized phase III trials with valspondar in either newly diagnosed or
resistant relapsed AML patients, and in multiple myeloma patients who have failed
front-line treatment.
PMID- 10676554
TI - The role of energy and fat in cancers of the breast and colon-rectum in a
southern European population.
AB - BACKGROUND: Several uncertainties remain with respect to the role of intake of
fat and/or total energy in the etiology of cancer of the breast and colon-rectum.
PATIENTS AND METHODS: Between 1991 and 1996, 2569 women with incident breast
cancer (median age: 55 years), 1953 subjects with cancer of the colon-rectum
(median age = 62), and 5155 hospital controls were interviewed in six Italian
areas. The validated food frequency questionnaire included questions on 78 foods
and recipes and specific questions on individual fat intake pattern. RESULTS:
Significant trends of increasing breast and colorectal cancer risk with
increasing intake emerged for bread and pasta, pork and processed meats and
potatoes (breast cancer only), cakes and desserts (colon-rectum cancers only),
and refined sugar. Most vegetables were inversely associated with cancer of the
colon and rectum, whereas only carrots and raw vegetables seemed to lower breast
cancer risk. High fruit intake was associated only with a reduction of rectal
cancer. Total energy intake was directly associated with all cancer sites. Among
macronutrients, high intake of starch and saturated fat seemed to lead to an
increase of cancer risk. High intakes of polyunsaturated fatty acids (chiefly
derived from olive oil and seed oils) were protective. Among micronutrients, beta
carotene, vitamin E, and calcium showed inverse associations with breast and
colorectal cancer risk. CONCLUSIONS: An excess of energy intake, particularly
from refined bread and pasta, can be an unfavourable feature of the Mediterranean
diet, in the presence of a sedentary lifestyle.
PMID- 10676555
TI - Once-only sigmoidoscopy.
AB - The rationale for infrequent screening for colorectal cancers by sigmoidoscopy of
the general population around age 60 is reviewed. A progress report for a trial
to evaluate this approach is also presented.
PMID- 10676556
TI - Adjuvant and induction chemotherapy in non-small cell lung cancer.
AB - About 25%-30% of patients with non-small cell lung cancer can be resected with
curative intent. However, systemic relapses occur in up to 70% of these patients.
Thus, postoperative adjuvant chemotherapy was evaluated in several randomised
trials but the results of these trials were inconclusive with a survival benefit
only in some trials. Shortcomings of these trials included low number of
patients, poor patient compliance and inadequate chemotherapy protocols. A recent
meta-analysis suggested an absolute survival benefit of 5% at five years for
postoperative cisplatin-based chemotherapy as compared to surgery alone. Thus
adjuvant chemotherapy with both improved chemotherapy protocols and improved anti
emetics is currently re-evaluated in several randomised trials on large patient
populations.
PMID- 10676557
TI - Chemotherapy of advanced non-small cell lung cancer.
AB - Until recently the role of chemotherapy in NSCLC has generally been questioned.
Major concerns included marginal activity, considerable toxicity and high cost of
this treatment. There has, however, been increasing evidence from individual
studies and meta-analyses that chemotherapy in advanced NSCLC is able to increase
survival and improve quality of life. In the past few years a series of active
drugs (paclitaxel, docetaxel, gemcitabine, vinorelbine, topotecan and irinotecan)
with novel mechanisms of action and favourable toxicity profiles have been
developed. These agents appear to hold the promise of added therapeutic benefit.
In consequence, chemotherapy has currently been considered an important part of
the standard treatment in selected patients with advanced NSCLC. Despite recent
developments, treatment outcomes in advanced NSCLC remain far from satisfactory,
and new effective means are desperately needed if more patients are to enjoy the
prospects of long-term survival.
PMID- 10676558
TI - Treatment of small cell lung cancer patients.
AB - Small cell lung cancers, comprising approximately 20% of lung cancers, are
rapidly growing and disseminating carcinomas which are initially chemosensitive
but acquire drug resistance during the course of disease. Thus, outcome is poor
with median survival of 10-16 months for patients with limited and 7-11 months
for patients with extensive disease. Polychemotherapy with established drugs
(platins, etoposide, anthracyclines, cyclophosphamide, ifosfamide and Vinca
alkaloids) plays the major role in the treatment of this disease and results in
overall response rates between 80%-95% for limited disease and 60%-80% for
extensive disease. Dose-intensified chemotherapy and high-dose chemotherapy with
peripheral blood progenitor cell support were tested in several trials but their
exact impact on outcome remains to be determined. New drugs including the taxanes
(paclitaxel, docetaxel), the topoisomerase I inhibitors (topotecan, irinotecan),
vinorelbine and gemcitabine are currently evaluated in clinical trials. In
limited disease, thoracic radiotherapy improves survival and prophylactic cranial
irradiation should be administered to those with a reasonable chance of cure.
PMID- 10676559
TI - Combined modality therapy of non-small cell lung cancers.
AB - Lung cancer represents the leading cause of cancer mortality. Non-small cell lung
cancer (NSCLC) accounts for about 75% to 80% of lung cancer cases and carries a 5
year survival of about 10% to 15% for all stages. Approximately one third of
NSCLC patients present with stage III disease, which is defined as locally
advanced tumour confined to the chest without distant metastasis. The traditional
treatment for stage III patients has been thoracic radiotherapy (RT). However,
the impact of thoracic RT alone has been minimal with published studies showing
median survival < 1 year and 5-year survival of 5% to 7%. Thus, the treatment of
stage III NSCLC remains a significant challenge. The metastatic nature of this
disease has been responsible for the poor survival statistics and emphasises the
need for effective systemic treatment. In recent years, cisplatin-containing
combination chemotherapy has emerged as a viable option in the treatment of
NSCLC. Combined modality therapy employing systemic (chemotherapy) and local (RT
with or without surgery) approaches has shown favourable results in patients with
stage III disease. Randomised studies have demonstrated the benefit of concurrent
or sequential chemoradiation in selected patients with a good performance status
and minimal weight loss. The exact sequence has yet to be determined. Moreover,
randomised studies in stage IIIA potentially resectable disease show survival
advantage for patients receiving combined modality treatment. Thus, combined
modality treatment has the potential to improve overall survival by increasing
both local and distal control. These recent reports of randomised clinical trials
of combined modality therapy for stage III NSCLC form the basis for this report.
Several new agents, like the taxanes, CPT-II and gemcitabine show promising
activity in NSCLC treatment. Ongoing studies are evaluating the potential role of
these new agents in combined modality treatment but since the phase III trials
have not been reported yet these studies will not be discussed.
PMID- 10676560
TI - Combined modality therapy of rectal cancers.
AB - Rectal cancer accounts for about 10% of new cancer cases each year. It strikes
men and women at nearly the same rate, generally in the range of 50-80 years of
age, with rising incidence with age. Despite simple screening procedures rectal
cancer is often advanced when discovered. Current trends in the management of
cancer have focused on organ preservation and improved quality of life without
compromising the overall survival. During the last decade substantial progress
has been made in treatment modalities: new and improved radiation techniques
(conformal radiotherapy, altered fractionation, brachytherapy), chemotherapy
(protracted infusion, use of radiosensitizers) and development of surgical
procedures-enabling safer postoperative irradiation. In patients with
advanced/unresectable disease aggressive combined chemoradiation can be added
prior to surgery to downstage the tumour and increase the proportion treated with
anal-rectal-sparing procedures. Preoperative chemoradiation therapy regimens are
as safe and tolerable as the standard postoperative treatment. In this
presentation indications for preoperative radiochemotherapy will be discussed in
detail, together with treatment-related side effects, prognostic parameters,
tumour response and outcome. Different irradiation settings and chemotherapy
schedules are described. In patients with primary resectable disease (mainly
Dukes C) several prospective randomised trials have shown less local recurrence
with postoperative combined modality therapy.
PMID- 10676561
TI - New possibilities in chemotherapy for colorectal cancer.
PMID- 10676562
TI - BRCA1 and BRCA2 and breast cancer incidence: a review.
AB - BACKGROUND: Epidemiological studies have repeatedly shown that having a family
history is a risk factor for female (and male) breast cancer. Some rare families
have many (4 or more) cases of early onset breast cancer (some of which also
include women with ovarian cancer) which are most clearly explained by an
autosomal dominant gene with high penetrance. DESIGN: Families with multiple
cases of early onset breast (and/or ovarian cancer) have been studied using
linkage analysis with the intention of finding the chromosomal region containing
such genes. RESULTS: Two predisposition genes, BRCA1 and BRCA2, have been mapped
and cloned. Mutations in these genes confer increased risk of cancer, although
the precise level of the increased risk is still unclear. The majority of
families with four or more cases of breast cancer diagnosed under the age of 60
years are due to mutations in BRCA1 or BRCA2. CONCLUSIONS: The importance of
these two genes to familial breast cancer and to breast cancer incidence overall
is becoming clearer; the current information is reviewed. The findings can be
immediately translated into clinical practice for these multiple case families.
The identification of such families raises a number of other important clinical
questions concerning patient management.
PMID- 10676563
TI - Screening mammography for early detection of breast cancer.
AB - From numerous studies on breast cancer it can be concluded that no single measure
can lessen the burden of this frequent cancer in women in all developed
countries. Complex strategies including primary prevention by identification of
risk factors and their modification, secondary prevention by earlier detection
and tertiary prevention by improving treatment outcome are needed to control the
disease. Besides age, the established breast cancer risk factors include certain
benign breast diseases, family history, ionising radiation, some reproductive
factors and obesity. Primary prevention includes general recommendation for
healthy lifestyle, e.g., avoidance of obesity, proper diet, physical activity and
moderate alcohol consumption. Randomised controlled trials conducted in the USA,
Canada, Scotland and Sweden have shown that regular mammography, alone or in
combination with clinical examination, is effective in reducing mortality for
about 30% in women over the age of 50, and much less in younger population.
However, mammography screening has several drawbacks, the major being its
tendency towards false positive and false negative results with all their
potential psychosocial consequences. High quality assurance and control, as well
as effective and readily available treatment, all of which demand high
investments, are indispensable for good results. Even in the absence of organised
screening, the availability of effective treatment may contribute to reduction in
breast cancer mortality.
PMID- 10676564
TI - Adjuvant therapy of breast cancer: update.
AB - The theoretical prediction that breast cancer is a systemic disease, and that
patients may benefit from addition of systemic therapy to local treatment, has
now been confirmed by three decades of clinical investigations. A long-term
follow up of individual trials and the International Overview based on meta
analyses clearly showed the potential of both hormonal therapies and chemotherapy
to prolong disease-free and overall survival in nearly all groups of patients.
The benefits have been demonstrated for both premenopausal and postmenopausal
patients, with both node-negative and node-positive disease. However, there is
still considerable uncertainty regarding the most appropriate treatment for each
individual patient. In the present review, the results of meta-analysis are
highlighted in the context of the new trials supporting the value of
chemoendocrine therapy and anthracycline-based therapy. The results of
prospective randomised trials evaluating the role of dose intensification, drug
sequencing and dose density are discussed. Also presented are new treatment
strategies, such as preoperative chemotherapy and high-dose chemotherapy with
stem cell support, the value of which remains to be confirmed. Future
possibilities opened by inclusion of biologics into adjuvant therapy are
discussed.
PMID- 10676565
TI - New developments in chemotherapy of advanced breast cancer.
AB - Anthracyclines and taxanes are the two most active classes of chemotherapy for
the treatment of advanced breast cancer. Recent studies have investigated
combination therapy including doxorubicin (Dox) and paclitaxel. The efficacy of
this combination has been established in a phase III study conducted by ECOG,
comparing Dox/paclitaxel versus Dox versus paclitaxel. The combination is
superior to Dox or paclitaxel with respect to response rate and time to disease
progression, indicating that the combination provides a new standard for the
first line treatment of metastatic breast cancer [1]. Phase II studies using
higher doses of Dox and using shorter infusions of paclitaxel have suggested the
combination can be further optimized; Gianni reported a 94% objective response
rate using Dox 60 mg/m2 followed by paclitaxel 175 mg/m2 given over three hours
[2]. The more active regimens are associated with enhanced cardiotoxicity; this
toxicity can be avoided, however, by limiting the exposure to doxorubicin. The
newer regimens have now been moved into phase III studies. Future progress for
this disease will depend on the introduction of new agents. Two novel drugs are
currently being investigated in randomised phase III trials as potentiators of
Dox and/or paclitaxel. One is a monoclonal antibody from Genentech (Herceptin,
trastuzumab) directed at the HER-2/neu oncogene, which is overexpressed in > 25%
of breast cancers [3]. Recent results indicate that Herceptin in combination with
paclitaxel (or with a Dox plus cyclophosphamide regimen) induces a higher
response rate (RR) and prolongs the time to disease progression when compared to
chemotherapy alone. The second agent N,N-diethyl-2[4-(phenylmethyl)-phenoxy]
ethanamine.HCl (DPPE, BMS-217380-01), when combined with Dox, was associated with
a higher RR than previously observed with Dox alone [4]. A randomized trial of
Dox versus Dox plus DPPE is ongoing. The possible mechanisms underlying chemo
potentiation by these agents are discussed. As new anthracycline/taxane
combinations establish themselves in earlier stages of the disease, the need for
effective, non-cross resistant salvage regimens will emerge.
PMID- 10676566
TI - Current issues in phase I trials: new study designs and informed consent
procedures.
PMID- 10676568
TI - Determinants of protogenetic interval in a west Mediterranean rural population:
La Alpujarra (southeast Spain).
AB - This paper analyzes the protogenetic interval determinants and the influence on
family size. The data came from La Alpujarra (Southeast Spain), consisting on a
sample of 847 families marrying through-out the first half of the present
century. The marital fertility includes 85% deliveries, 5% premarital births and
the remaining 10% premarital conceptions. The protogenetic interval was clearly
associated with the reproductive success since family size was nearly one child
greater for short intervals (= < 16 months). The protogenetic interval largely
depends on the occurrence of miscarriages preceding the first liveborn delivery
as well as on maternal age. Consanguineous couples show slightly shorter
intervals. A temporal decrease of protogenetic intervals was observed.
PMID- 10676567
TI - New approaches in cancer treatment.
AB - Major advances in cellular biology, genetics, pharmacology and immunology in the
past decade are beginning to be translated into progress in cancer treatment.
This progress is manifested by new cytotoxic drugs which have recently entered
clinical practice (taxanes, topoisomerase I inhibitors, gemcitabine, vinorelbine,
new purines), as well as the efficacy of monoclonal antibody therapies against
the CD-20 antigen of B-cell lymphomas and the Her2/neu oncogene in breast cancer.
Several new drugs in development are targeted at reversal or prevention of the
multidrug resistance mechanism caused by expression of the MDR1 gene (P
glycoprotein). Tumour angiogenesis as a target is being studied in several early
clinical trials. As with many other biological therapies, the evaluation of these
compounds and their integration with standard therapies presents a major
challenge to clinical investigators. The emerging field of genomics and gene
expression micro-arrays will provide enormous information about the biology of
cancers. This technology offers great opportunities for the discovery of new
therapeutic targets, which should provide a basis for the design and evaluation
of many new agents in the coming decade.
PMID- 10676570
TI - Finger dermatoglyphics in the Corsican population (France).
AB - Finger pattern types, pattern intensity indices and finger ridge counts in 110
individuals (54 males and 56 females) from Corte in the central area of Corsica
(France) were investigated. The comparison of the Corsican qualitative and
quantitative digital dermatoglyphics with those from other samples of
Mediterranean and European countries show a clearcut difference between Corsicans
and Continental Italian populations and a great affinity between Corsicans and
Sardinians. These results are regarded as compatible with the interpretation of
archaeological, historical and genetic evidence.
PMID- 10676569
TI - Comparisons of fatness indicators in Budapest children.
AB - The aim of this study was to estimate the fatness level of Budapest children and
youth in different ways and to compare these estimations using a large
representative sample. Eighteen body measurements were taken on 2606 healthy boys
and 2471 healthy girls aged between 3 and 18 years. About 20% of this sample was
measured by the Futrex 5000A near infrared (NIR) spectrophotometer to assess the
body fat percent (data of 419 boys and 462 girls aged between 5 and 18 years were
analysed). Triceps skinfold thickness (TSF), sum of triceps, medial calf,
subscapular and suprailiac skinfold thicknesses (SFS), body fat percent estimated
according to Slaughter et al. (%BF), BMI (calculated from height and weight) and
body fat percent assessed by NIR-method (NIR%BF) were compared. chi 2 tests of
independence show significant connections among the distributions ranged by the
five fatness indicators. However, correlation coefficients and standard errors
indicate that strong relationships are only among the assessments based on
skinfold thicknesses (r = 0.92-0.97, SEE = 1.8-2.6%). BMI and NIR%BF assess body
fatness differently compared to skinfold thicknesses: r-values are moderate and
SEE-values are relatively large (r = 0.59-0.87, SEE = 1.9-4.7%). These findings
can be seen in both the boys and the girls. NIR%BF comparing to %BF significantly
overpredicts body fat percent in the boys and significantly underpredicts it in
the girls. BMI, height and weight are not in significant correlation with NIR%BF
in the boys but there are moderate correlations in the girls. Our suggestion is
that more research is needed with the use of NIR-method in children and
adolescents, and it is necessary to refine prediction equations taking into
consideration very carefully sex sand age differences.
PMID- 10676571
TI - Dermatoglyphic characteristics of a population from the central Rhodopes (south
Bulgaria).
AB - The finger and palmar prints of a total of 386 individuals (182 males and 204
females) at an age between 10 and 18 years from the region of the villages
Petkovo and Banite, situated along the river Malka Arda in the Central Rhodopes,
were studied. The following dermatoglyphic traits were analyzed: pattern
intensity index (PII), the main line or Cummin's index (MLI), the frequencies of
the proximal palmar triradius (t), the true hypothenar patterns (Hy) and the
accessory interdigital triradii (AIT). The specific dermatoglyphic complexes
after Heet were also determined for the population under study. A peculiarity of
this population is the appearance of a clearly expressed Eastern Complex (EC),
which accounts for 53.1% in the males and for 48.8% in the females. These values
of EC and the calculated dermatoglyphic distances (DD) after Heet show a
similarity between the examined population and a number of populations from the
Volga region, Northern Caucasus, Middle Asia and Siberia. This similarity could
be explained with the preservation of the genetic heritage of the proto
Bulgarians, one of the three main components of the modern Bulgarians.
PMID- 10676572
TI - Study on pottical type, palmar and plantar digital formulae, hand clasping, arm
folding, handedness, leg folding and stride type in the Daur population, China.
AB - The pottical type, palmar and plantar digital formulae, hand clasping, arm
folding, handedness, leg folding and stride type have been investigated on a
sample of 143 male and 160 female students of the Daur population of Molidawa
Banner, Inner Mongolia. The results of this study are the following: 1. the
frequency of the hyperextensive pottical type is 49.17%, the relative length of
index over annularis 12.21%, right hand clasping 45.87%, right arm folding
49.50%, right handedness 94.39%, right leg folding 72.28% and right stride type
44.88%, 2. pottical type, hand clasping, handedness, leg folding and stride type
do not show significant sex differences, 3. there are some relations between hand
clasping and arm folding as well as between arm folding and stride type, 4.
compared with other population groups, the Daur population shows a low frequency
of right hand clasping, a moderate frequency of right arm folding and a low
frequency of left handedness.
PMID- 10676573
TI - Is there a need for blood substitutes in the new millennium and what should we
expect in the way of safety and efficacy?
PMID- 10676574
TI - Gene therapy for hemophilia.
AB - Hemophilia A and B are X-linked genetic disorders caused by deficiency of the
coagulation factors VIII and IX, respectively. Because of the health hazards and
costs of current product replacement therapy, much effort is devoted to the
development of gene therapy for these disorders. Approaches to gene therapy for
the hemophilias include: ex vivo gene therapy in which cells from the intended
recipients are explanted, genetically modified to secrete Factor VIII or IX, and
reimplanted into the donor; in vivo gene therapy in which Factor VIII or IX
encoding vectors are directly injected into the recipient; and non-autologous
gene therapy in which universal cell lines engineered to secrete Factor VIII or
IX are enclosed in immuno-protective devices before implantation into recipients.
Research into these approaches is aided by the many murine and canine models
available. While problems of achieving high and sustained levels of factor
delivery, and issues related to efficacy, safety and cost are still to be
resolved, progress in gene therapy for the hemophilias has been encouraging and
is likely to reach human clinical trial in the foreseeable future.
PMID- 10676575
TI - Second-generation perfluorocarbon emulsion blood substitutes.
AB - A novel series of perfluorocarbon (PFC) emulsions, based on perfluorodecalin
(C10F18) and stabilised with up to 2.5% (w/v) of lecithin have been produced for
evaluation as injectable, temporary respiratory gas-carrying blood substitutes.
Some formulations contained 1.0% (w/v) of perfluorodimorpholinopropane
(C11F22N2O2) to retard droplet growth through molecular diffusion (Ostwald
Ripening). Other emulsions contained novel, amphiphilic fluorinated surfactants,
such as, for example, the monocarbamate, C8F17C2H4NHC(O)(CH2CH2O)2Me (designated
compound P6), at 0.1% (w/v) to enhance stability. Emulsions were prepared by
homogenisation, were steam sterilisable and were stable for > 300 days (25
degrees C). Injection of rats (7.5 ml kg-1 b.w.) with emulsions produced
significant (P < 0.05), transient increases in liver and spleen weights. One
emulsion inhibited phorbol 12-myristate 13-acetate (PMA)-stimulated, Luminol
enhanced, chemiluminescence of human polymorphonuclear leucocytes (PMNL) in
vitro, suggesting possible applications in ischaemic tissues for suppressing PMNL
mediated inflammation. The P6 fluoro-surfactant inhibited spontaneous platelet
aggregation in hirudin-anticoagulated human blood in vitro, suggesting possible
applications as an anti-thrombotic agent.
PMID- 10676576
TI - Sustained drug release characteristics of biodegradable composite poly(d,l)lactic
acid-poly(l)lactic acid microcapsules containing ciprofloxacin.
AB - Ciprofloxacin polylactic microcapsules were prepared by the phase separation
process. Two types of polylactic acid, poly(d,l)lactic acid and poly(l)lactic
acid were combined as membrane materials to prevent the aggregation which
happened frequently in the phase separation process. The polymer compositions of
the microcapsules can influence the release rate of Ciprofloxacin. The optimal
release rate of the drug can be obtained by modifying microcapsule compositions.
Poly(d,l)lactic acid is superior in slowing the rate of drug release than
poly(l)lactic acid. However, poly(l)lactic acid is necessary in the preparation
of the microcapsules to prevent aggregation.
PMID- 10676577
TI - Preparation of biodegradable microspheres of testosterone with poly(D,L-lactide
co-glycolide) and test of drug release in vitro.
AB - Biodegradable microspheres formulation of testosterone (T) can be used as a new
physiological approach for androgen replacement in hypogonadal men. In this
study, poly(D,L-lactide-co-glycolide) (PLGA) microspheres containing T were
prepared by a solvent-evaporation/solvent-diffusion process and the drug release
tests of the microspheres were carried out in vitro. T/PLGA microspheres with
good yield, desired size and satisfied drug loading were obtained. A significant
testosterone sustained release was shown in the drug release tests in vitro.
Since PLGA microspheres preparations are normally sterilized by colbat-60
irradiation, the effects of 25 kGy colbat-60 irradiation on physicochemical
properties and in vitro drug release profile of T/PLGA microsphere were
investigated. The results showed that the irradiation didn't have any effects on
the physicochemical properties of T. Though about one-third decrease in molecular
weight of PLGA was caused by the irradiation, no significant changes were
observed on the drug release profile in vitro.
PMID- 10676578
TI - Evaluation of heparin immobilized chitosan-PEG microbeads for charcoal
encapsulation and endotoxin removal.
AB - A technique is described to encapsulate activated charcoal for hemoperfusion to
be used in an artificial liver support. Activated charcoal was encapsulated
within chitosan-PEG matrix and subsequently surface modified with PGE1 or heparin
(hep-AC-PEGCB) via the glutaraldehyde functionalities. This novel matrix was used
as the supports for perfusion of endotoxin, under a flow rate of 30 ml/mt.
Endotoxin adsorption was quantitatively measured by the method of Limulus
Amebocyte lysate test. It seems, the hep-AC-PEGCB may be a good adsorbent system
for the removal of toxic endotoxin, and the system may be useful for
detoxification of blood. The hep-AC-PEGCB matrix had improved biocompatibility as
demonstrated from their hemolytic potential and charcoal release. However,
further studies are needed to determine their behaviour under clinical
conditions.
PMID- 10676579
TI - The anticalcification effect of polyethylene glycol-immobilized on hexamethylene
diisocyanate treated pericardium.
AB - Pathologic calcification is thought to be the main cause of failure in the
present generation tissue valves fabricated from glutaraldehyde pretreated bovine
pericardium (BP). The present investigation describes the in vitro calcification
and enzymatic degradation of bovine pericardia after hexamethylene diisocyanate
(HMDIC) crosslinking and subsequent modification with polyethylene glycol. The
enzymatic degradation of these treated surfaces were monitored by scanning
electron micrography and tensile strength measurements. Various proteases, such
as alpha-chymotrypsin, bromelain, esterase, trypsin and collagenase were
investigated for tissue stability. Incubation of these enzymes with crosslinked
pericardia had variably reduced their tensile strength. Among these treated
surfaces, polyethylene glycol (PEG) grafted BP via isocyanate functionalities had
retained maximum strength. The PEG modified tissues had also indicated a
substantial reduction in calcification, when compared to other treated tissues.
Further, the biocompatibility of various pericardial tissues were established by
platelet adhesion and octane contact angle measurements. It is assumed that the
PEG modification of pericardium may interfere with the cellular activation of
injury (platelets) to reduce tissue associated calcification. In conclusion, it
seems the PEG modification of bovine pericardium via HMDIC may provide new ways
of controlling tissue biodegradation and calcification. However, more in vivo
studies are needed to develop applications.
PMID- 10676580
TI - Polycation-coated polyanion microspheres of urease for urea hydrolysis.
AB - Urease (EC 3.5.1.5) was immobilized within polyanionic
carboxymethylcellulose/alginate (CMC/Alg) microspheres coated with a cationic
polysaccharide, chitosan (C). Coating with chitosan improved the mechanically
durability of the polyanionic microspheres, as well as increased enzyme
immobilization yield [approximately 0.4 mg.mL-1 gel]. The effects of chitosan
coating and CMC/Alg ratio on the water uptake and spherical morphology of the
microspheres were investigated. The optimal pH of urease was not extensively
affected by the immobilization procedure. However, the optimal temperature of
urease activity increased upto 60 and 65 degrees C within CMC/Alg and C(CMC/Alg)
microspheres, respectively, while the optimum for the free enzyme was 50 degrees
C. The half life (t1/2) and deactivation rate constant (kd) of free urease were
79 min and 8.77 x 10(-3) min-1, respectively, whilst the t1/2 and kd values of
urease within polyanion and polycation-coated polyanion microspheres were 142 min
and 4.88 x 10(-3).min-1, and 179 min and 3.87 x 10(-3).min-1, at 80 degrees C,
respectively. While the activation energy of the hydrolysis reaction of free
urease was found to be 11.86 kJ.M-1.dm-3, it increased to 18.91 and 20.02 kJ.M
1.dm-3, for the immobilized urease within CMC/Alg and C(CMC/Alg) microspheres,
respectively. The free enzyme exhibited K(m) and Vmax values of 2.85 mM.dm-3 and
31.9 mM.dm-3.s-1.g-1p-1, respectively, whilst the K(m) and Vmax for urease within
polyanion and polycation-coated polyanion microspheres were 3.94 mM.dm-3 and 73.4
mM.dm-3.s-1.g-1.p-1, and 4.22 mM.dm-3 and 81.4 mM.dm-3.s-1.g-1.p-1, in the same
order. C(CMC/Alg) microspheres showed a nearly stable urease activity of around
80-85% of the initial maximum activity, after the first 100 minutes.
PMID- 10676581
TI - Pain perception and response: central nervous system mechanisms.
AB - Although several decades of studies have detailed peripheral and ascending
nociceptive pathways to the thalamus and cerebral cortex, pain is a symptom that
has remained difficult to characterize anatomically and physiologically. Positron
emission tomography (PET) and functional magnetic imaging (fMRI) have recently
demonstrated a number of cerebral and brain stem loci responding to cutaneous
noxious stimuli. However, intersubject variability, both in the frequency and
increased or decreased intensity of the responses, has caused uncertainty as to
their significance. Nevertheless, the large number of available imaging studies
have shown that many areas with recognized functions are frequently affected by
painful stimuli. With this evidence and recent developments in tracing central
nervous system connections between areas responding to noxious stimuli, it is
possible to identify nociceptive pathways that are within, or contribute to,
afferent spino-thalamo-cortical sensory and efferent skeletomotor and autonomic
motor systems. In this study it is proposed that cortical and nuclear mechanisms
for pain perception and response are hierarchically arranged with the prefrontal
cortex at its highest level. Nevertheless, all components make particular
contributions without which certain nociceptive failures can occur, as in
pathological pain arising in some cases of nervous system injury.
PMID- 10676582
TI - Predicting dementia in the elderly: a physician-friendly formula.
PMID- 10676583
TI - Predicting who will develop dementia in a cohort of Canadian seniors.
AB - OBJECTIVES: We examined whether easily attainable variables were useful in
predicting who became demented over a five year period and determined the rates
of incident dementia for different categories of mild cognitive impairment.
METHODS: This was a cohort study of subjects recruited nationally in a population
based survey of Canadians 65 years and older (the Canadian Study of Health and
Aging). After standardized clinical assessments, a subset of subjects (n = 1782)
was categorized as not demented at time one. Identical study methods allowed a
reassessment of the cognitive status of surviving subjects (n = 892) five years
later. RESULTS: Three baseline variables (Modified Mini Mental State (3MS) score,
subject's age, and an informant's report of the presence of memory problems) were
statistically significant predictors of the development of a dementia. An
equation incorporating these three variables had a sensitivity of 79% and a
specificity of 56% for predicting dementia among survivors at time two. An
equation substituting the MMSE for the 3MS showed similar results. The various
categories of mild cognitive impairment examined showed significantly different
likelihoods for the subsequent development of a dementia. Some categories with a
higher dementia risk were characterized by inclusion criteria requiring
neuropsychological test scores that were greater than one standard deviation (SD)
below the mean of age based normative data. CONCLUSION: In the absence of
extensive laboratory, radiologic or neuropsychological tests, simple variables
that can be easily determined in the course of a single clinical encounter were
useful in predicting subjects with a higher risk of developing dementia. Attempts
to use neuropsychological results to predict the development of dementia should
look for significant impairments on age-standardized tests.
PMID- 10676584
TI - Use of ambulatory electrocardiography for the detection of paroxysmal atrial
fibrillation in patients with stroke. Canadian Task Force on Preventive Health
Care.
AB - BACKGROUND: Patients with stroke commonly undergo investigations to determine the
underlying cause of stroke. These investigations often include ambulatory
electrocardiography to detect paroxysmal atrial fibrillation. There is
conflicting evidence in the literature regarding whether routine ambulatory
electrocardiography should be performed in all or selected stroke patients. This
paper reviews the available evidence on (1) the yield of ambulatory
electrocardiography in detecting paroxysmal atrial fibrillation in patients with
stroke or transient ischemic attack and (2) the effectiveness of anticoagulation
in preventing recurrent stroke in patients with paroxysmal atrial fibrillation.
METHODS: A MEDLINE search for primary articles was performed, and the references
were reviewed manually. In addition, citations were obtained from experts. The
evidence was systematically reviewed using the evidence-based methodology of the
Canadian Task Force on Preventive Health Care. RESULTS: Ambulatory
electrocardiography can detect atrial fibrillation not found on initial
electrocardiogram in between 1% and 5% of people with stroke. Ambulatory
electrocardiography is generally safe. The risk of recurrent stroke in the
setting of paroxysmal atrial fibrillation is uncertain, but appears to be similar
to that seen with chronic atrial fibrillation (about 12% per year). Therapy with
warfarin may reduce this risk by about two-thirds as compared to placebo. The
annual risk of major bleeding with warfarin therapy is between 1% and 3% but
rates for individual patients depend on various specific risk factors.
INTERPRETATION: There is insufficient evidence to recommend for or against the
use of ambulatory electrocardiography for the detection of paroxysmal atrial
fibrillation in either selected or unselected patients with stroke (C
Recommendation). There is fair evidence to recommend therapy with warfarin for
patients with stroke and paroxysmal atrial fibrillation (B Recommendation).
PMID- 10676585
TI - Predictors of poor outcome in patients with a spontaneous cerebellar hematoma.
AB - BACKGROUND AND PURPOSE: The authors studied the clinical and neuroimaging
features of cerebellar hematomas to predict poor outcome using comprehensive
statistical models. METHODS: We retrospectively reviewed clinical and
neuroimaging features in 94 patients with spontaneous cerebellar hematomas to
identify predictive features for a poor neurologic outcome, defined as death or
dismissal to long-term care facility. Data were analyzed using chi square and
Fisher's exact test with calculation of odd's ratios together with 95% confidence
intervals. RESULTS: Clinical and neuroradiologic predictors for a poor outcome at
p < 0.05 were admission systolic blood pressure > 200 mm Hg, hematoma size > 3
cm, visible brain stem distortion, and acute hydrocephalus. Presenting findings
predicting subsequent death at p < 0.05 were abnormal corneal and oculocephalic
responses, Glasgow coma sum score less than 8, motor response less than
localization to pain, acute hydrocephalus and intraventricular hemorrhage.
CONCLUSION: A tree-based analysis model using binary recursive partitioning
showed that cornea reflex, hydrocephalus, doll's eyes, age, and size were the
most important discriminating factors. Absent corneal reflexes on admission
highly predicts poor outcome (86 percent, confidence limits 67-96 percent). When
a cornea reflex is present, acute hydrocephalus predicts poor outcome but only
when doll's eyes are additionally absent.
PMID- 10676586
TI - Generic substitution for brand name antiepileptic drugs: a survey.
AB - BACKGROUND/OBJECTIVE: There are presently 26 different generic preparations for
five brand name antiepileptic drugs (AEDs) on the Canadian market with others
likely to be released in the near future. The purpose of this review is to
examine the basis for the controversy surrounding generic substitution for brand
name antiepileptic drugs, to present the results of a survey of neurologists' and
patients' attitudes toward generic substitution and to increase neurologists'
awareness of the issues. METHODS: The current federal and provincial regulations
pertaining to generic drug approval and substitution are reviewed. Published
anecdotal and survey reports of the effectiveness and tolerability of generic
substitution for AEDs are reviewed. A pilot questionnaire survey of 83 patients
from four adult epilepsy clinics and 46 neurologists from across Canada was
undertaken to determine attitudes toward generic substitution. RESULTS AND
CONCLUSIONS: Several authors have suggested that some AEDs, particularly those
with a narrow therapeutic index, may pose problems with generic substitution.
Although generic AEDs are lower in price, possible increased side effects and
morbidity and the need for closer monitoring could partially offset the cost
savings. The results of our survey highlight significant unawareness of the
process of generic substitution among both patients and neurologists and reveal a
general level of discomfort among neurologists to prescribe generic AEDs. Further
data should be obtained about the potential consequences of generic substitution
in epilepsy patients.
PMID- 10676587
TI - Craniotomy revisited: techniques for improved access and reconstruction.
AB - OBJECTIVE: To describe simple modifications of the technique of opening and
closure of the craniotomy to improve basal exposure and reconstruction. METHODS:
The modifications involve: a) additional soft-tissue dissection which is carried
downward to the base of the ear and to the orbital rim, exposing the orbital rim
and malar eminence without removing the bone; b) cutting the bone flap so that
'bridges' of bone remain that help to stabilize the flap when it is returned to
the cranium at the end of the operation; c) the wedging of bone chips between the
bone flap and native cranium at the time the bone is being reaffixed so as to
provide firm stability by diminishing movement of the bone flap; d) the use of
bone dust and bone chips mixed with the patient's blood to seal and bridge the
gap between the bone flap and the native bone; e) reattachment of the temporalis
muscle with the bone flap sutures. An 'inlay' technique of duraplasty is also
described. RESULTS AND CONCLUSION: These simple modifications of craniotomy
provide better basal exposure and reconstruction with little additional operating
time at no additional cost.
PMID- 10676588
TI - Postictal aphasia and paresis: a clinical and intracerebral EEG study.
AB - BACKGROUND: We examined the lateralizing value of postictal language and motor
deficits and studied their underlying mechanisms. PATIENTS AND METHODS: The total
sample consisted of 35 patients (26 temporals, 8 frontals, 1 parietal) with a
good postsurgical outcome (Engel's class I and II). Postictal examination was
blindly reviewed on videotapes. In 15 cases (29 seizures), postictal language
manifestations were analyzed in relation with the diffusion of the epileptic
discharge recorded by intracerebral EEG. Language dominance was determined by the
intracarotid amobarbital test. RESULTS: Postictal aphasia was observed only when
(1) seizure originated in the dominant hemisphere and (2) ictal activity spread
to language areas (Wernicke and/or Broca areas). When the epileptic focus was in
the nondominant hemisphere, no postictal aphasia was observed even if there was
secondary generalization of ictal activity affecting the language areas of the
dominant hemisphere. Postictal motor deficits also had a strong lateralizing
value even when seizures were secondarily generalized. CONCLUSION: Postictal
aphasia in temporal epilepsies and postical motor deficits in temporal and extra
temporal epilepsies provided excellent lateralizing information. Postictal
deficits appear to be the result of inhibitory mechanisms induced by previous
ictal activity of the structures related to these functions.
PMID- 10676589
TI - Post-traumatic cervical dystonia: a distinct entity?
AB - BACKGROUND/OBJECTIVE: The incidence of head/neck trauma preceding cervical
dystonia (CD) has been reported to be 5-21%. There are few reports comparing the
clinical characteristics of patients with and without a history of injury. Our
aim was to compare the clinical characteristics of idiopathic CD (CD-I) to those
with onset precipitated by trauma (CD-T). METHODS: We evaluated 114 consecutive
patients with CD over a 9-month period. All patients were interviewed using a
detailed questionnaire and had a neurological examination. Their clinical charts
were also reviewed. RESULTS: Fourteen patients (12%) had mild head/neck injury
within a year preceding the onset of CD. Between the two groups (CD-I and CD-T),
the gender distribution (F:M of 3:2), family history of movement disorders (32%
vs. 29%), the prevalence of gestes antagonistes (65% vs. 64%), and response to
botulinum toxin were similar. There were non-specific trends, including an
earlier age of onset (mean ages 43.3 vs. 37.6), higher prevalence of neck pain
(86% vs. 100%), head tremor (67% vs. 79%), and dystonia in other body parts (23%
vs. 36%) in CD-T. CONCLUSIONS: CD-I and CD-T are clinically similar. Trauma may
be a triggering factor in CD but this was only supported by non-significant
trends in its earlier age of onset.
PMID- 10676590
TI - Difference of disability between electrophysiologic subgroups of essential
tremor.
AB - OBJECTIVE: The aim of the study was to test the validity of the controversial
subdivision of essential tremor (ET) patients into electrophysiological
subgroups. METHODS: We evaluated a hundred patients with ET using surface
electromyographic (EMG) recordings of antagonists forearm muscles and
distinguished three groups: the first group showed synchronous activity of
antagonistic muscles, the second showed alternating activity of antagonist
muscles; and the third group consisted of patients whose EMG recordings were not
compatible with the other two groups. We compared patients with synchronous and
alternating activity in terms of sex, age at onset, duration of illness, family
history of tremor, symmetry and frequency of tremor, and the scores of a
disability scale. RESULTS: The only significant difference between the patients
with synchronous and alternating activity was that the patients with synchronous
activity were more disabled. CONCLUSION: This result adds to the evidence for
distinct electrophysiological subgroups of ET with distinct clinical properties.
PMID- 10676591
TI - Clinical and electromyographic examinations of patients with essential tremor.
AB - BACKGROUND: It is believed that no clinical differences exist among essential,
familial and senile tremor, or between the tremor with synchronous or alternating
electromyographic activity. The aim of this study was to evaluate the clinical
and electromyographic findings in a large group of patients with different types
of essential tremor. METHODS: Two hundred and twenty patients with sporadic,
familial or senile variants of essential tremor were examined. According to the
electromyographic activity recorded from the antagonistic muscles, the patients
were subdivided into a group with synchronous (SYN) and a group with alternating
(ALT) activity. The historical aspects of the disease were noted, and a detailed
neurological examination was performed. RESULTS: A widespread tremor involving
upper and lower limbs and 3-4 different anatomical regions was typical for
familial tremor. It also had higher amplitude than the sporadic and senile
tremor. ALT tremor had a higher amplitude and longer burst duration than SYN and
more often involved lower limbs. Rest tremor was common in the ALT group.
Overall, ALT tremor was more common than previously supposed. CONCLUSION: The
familial and ALT tremors are more disabling than other types of essential tremor.
Since electromyographic ALT activity is common in essential tremor, its presence
does not reliably distinguish essential and Parkinsonian tremor.
PMID- 10676592
TI - Traumatic carotid-cavernous fistula.
PMID- 10676593
TI - Hemorrhagic moyamoya disease during pregnancy.
AB - BACKGROUND: Intracranial hemorrhage in pregnant patients with Moyamoya disease is
rare. We review the case of one such patient who presented with pre-eclampsia and
a catastrophic intracerebral hemorrhage in order to highlight the associated
management difficulties. METHODS: A case of a pregnant (31 weeks) female brought
to the emergency department with hypertension and a progressive decrease in her
level of consciousness is presented. She rapidly developed a dilated right pupil
and left extensor posturing. A CT scan of her head showed a large putamenal
intracerebral hemorrhage. She was intubated, ventilated and given intravenous
mannitol and magnesium sulfate. She underwent a simultaneous craniotomy and
Cesarean section. Post-operatively the patient's ICP and jugular venous
saturation were monitored in the intensive care unit. RESULTS: The patient
delivered a 1185 g infant who did well. The patient's ICP was well controlled
until the tenth post-operative day when she developed malignant brain edema and
died. CONCLUSION: This case highlights three important points. First,
simultaneous craniotomy and Cesarean section can be performed. Second,
intraoperative control of bleeding Moyamoya vessels is described. Third, the
difficult post-operative management of these cases is highlighted. The literature
regarding Moyamoya disease and pregnancy is reviewed and some recommendations for
the management of this rare but potentially deadly condition are presented.
PMID- 10676594
TI - Ogilvie's syndrome as a rare complication of lumbar disc surgery.
AB - BACKGROUND: In this study we report a rare complication after lumbar surgery,
Ogilvie's syndrome, that presents as acute colonic dilatation in the absence of
mechanical obstruction. CASE: A 43-year-old obese woman underwent lumbar surgery
for L4-L5 lumbar disc herniation. The patient complained of persistent abdominal
distention and lack of bowel sounds. Plain radiography and ultrasonography
revealed massive dilatation of the colon. Nasogastric aspiration was initiated
and all analgesic drugs were withdrawn. Abdominal distention gradually
disappeared within three days. CONCLUSIONS: Only three cases of Ogilvie's
syndrome following lumbar spinal surgery have been reported in the literature. In
our case obesity, chronic constipation, and narcotic drugs were the most likely
precipitating causes. Ogilvie's syndrome may resolve with conservative treatment,
but if the cecal diameter continues to increase, colonoscopy or laparotomy may be
needed to prevent perforation of colon.
PMID- 10676595
TI - Neurology and neurosurgery at the Montreal General Hospital 1960-1980.
PMID- 10676596
TI - Re: Management of Parkinson's disease: a review of current and new therapies.
Tilak Mendis, Oksana Suchowersky, Anthony Lang, Serge Gauthier. Can J Neurol Sci
1999;26:89-103.
PMID- 10676597
TI - Amiodarone: what have we learned from clinical trials?
AB - Amiodarone is an antiarrhythmic agent commonly used in the treatment of
supraventricular and ventricular tachyarrhythmias. This paper reviews clinical
trials in which amiodarone was used in one of the treatment arms. Key post
myocardial infarction trials include EMIAT and CAMIAT, both of which demonstrated
that amiodarone reduced arrhythmic but not overall mortality. In patients with
congestive heart failure (CHF), amiodarone was associated with a neutral survival
in CHF/STAT and improvement in survival in GESICA. In patients with nonsustained
ventricular tachycardia, the MADIT trial demonstrated that therapy with an
implantable cardioverter-defibrillator (ICD) improved survival compared with the
antiarrhythmic drug arm in such patients, most of whom were taking amiodarone. In
sustained VT/VF patients, the CASCADE trial demonstrated that empiric amiodarone
lowered arrhythmic recurrence rates compared with other drugs guided by serial
Holter or electrophysiologic studies. Several trials including AVID, CIDS, and
CASH have demonstrated the superiority of ICD therapy compared with empiric
amiodarone in improving overall survival. Clinical implications of these trials
are discussed.
PMID- 10676598
TI - Five-year mortality in patients with acute chest pain in relation to smoking
habits.
AB - BACKGROUND: Smoking is one of the major risk indicators for development of
coronary artery disease, and smokers develop acute myocardial infarction (AMI)
approximately a decade earlier than nonsmokers. In smokers with established
coronary artery disease, quitting smoking has been associated with a more
favorable prognosis. However, most of these studies comprised younger patients,
the majority of whom were males. HYPOTHESIS: The purpose of the study was to
determine mortality, mode of death, and risk indicators of death in relation to
smoking habits among consecutive patients admitted to the emergency department
with acute chest pain. METHODS: In all, 4,553 patients admitted with acute chest
pain to the emergency department at Sahlgrenska University Hospital during a
period of 21 months were included in the analyses and were prospectively followed
for 5 years. RESULTS: Of these patients, 36% admitted current smoking. They were
younger and had a lower prevalence of previous cardiovascular diseases than did
nonsmokers. The 5-year mortality was 19.4% among smokers and 24.9% among non
smokers (p < 0.0001). However, when adjusting for difference in age, smoking was
associated with an increased risk [relative risk (RR) 1.51; 95% confidence
interval (CI) 1.32-1.74; p < 0.0001]. Among patients presenting originally with
chest pain, the increased mortality for smokers was more pronounced in patients
with non-acute than acute myocardial infarction (AMI). Among patients who died,
death in smokers was less frequently associated with new-onset myocardial
infarction (MI) and congestive heart failure. Among those who smoked at onset of
symptoms and were alive 1 year later, 25% had stopped smoking. Patients with a
confirmed AMI who continued smoking 1 year after onset of symptoms had a higher
mortality (28.4%) during the subsequent 4 years than patients who stopped smoking
(15.2%; p = 0.049). CONCLUSION: In consecutive patients admitted to the emergency
department with acute chest pain, current smoking was significantly associated
with an increased risk of death during 5 years of follow-up. Among patients who
died, death in smokers was less frequently associated with new-onset MI and
congestive heart failure than was death in nonsmokers.
PMID- 10676599
TI - Intravenous Optison (FS069) enhances pulmonary vein flow velocity signals: a
multicenter study.
AB - BACKGROUND: Pulmonary vein spectral Doppler signals to characterize ventricular
diastolic and systolic function, though often difficult to obtain, can be
enhanced using contrast agents. HYPOTHESIS: The objective of this study was to
determine the efficacy of the intravenous contrast agent Optison for enhancement
of Doppler signals in patients with poor signals on two-dimensional
echocardiographic examinations. METHODS: Enhancement of pulmonary venous flow was
evaluated in 191 patients at 0.2, 0.5, 3.0, and 5.0 ml per injection. RESULTS:
Greatest contrast enhancement for right and left pulmonary veins was observed at
the highest doses. At 0.5 ml, conversion from inadequate to adequate was observed
in right and left pulmonary veins in 48.0 and 79.3% of patients, respectively,
while any degree of improvement was 54.4 and 65.8%, respectively. The adverse
event rate (6.5%) was similar to a first-generation agent. CONCLUSION: The
results demonstrate that Optison is a safe and effective contrast agent for
improving visualization of pulmonary Doppler signals, especially the left
pulmonary vein.
PMID- 10676600
TI - Effects of early captopril therapy after myocardial infarction on the incidence
of late potentials.
AB - BACKGROUND: Late potentials (LP) on signal-averaged electrocardiography (SAECG),
recorded 6 to 30 days after an acute myocardial infarction (AMI), identify
patients at risk for late arrhythmic events. Angiotensin-converting enzyme (ACE)
inhibitors have been shown to reduce ventricular remodeling and cardiovascular
mortality after AMI. HYPOTHESIS: The aim of this study was to investigate the
effect of early (< 24 h) administration of captopril on the presence of LP on
Days 6-30 after AMI. METHODS: The study included 117 patients with a first AMI;
63 patients (53 men and 10 women, aged 59 +/- 12 years), 35 with an anterior and
28 with an inferior AMI (44 thrombolyzed), received early captopril therapy. The
control group consisted of 54 age-matched patients (39 men and 15 women, aged 60
+/- 12 years), 19 with an anterior and 35 with an inferior AMI (31 thrombolyzed,
p = NS), who did not receive early therapy with an ACE inhibitor. The mean left
ventricular ejection fraction was similar in both groups (48 vs. 46%). Time
domain analysis of SAECG was performed using a band-pass filter of 40-250 Hz.
Late potentials were considered present if any two of three criteria were met:
(1) Filtered QRS duration (QRSD) > 114 ms, (2) root-mean-square voltage of the
last 40 ms of the QRS complex (RMS) < 20 microV, and (3) duration of low
amplitude (< 40 microV) signal of the terminal portion of the QRS (LAS) > 38 ms.
RESULTS: In the two groups of patients there were no differences in mean values
of SAECG parameters. No patient was receiving any antiarrhythmic drugs. In the
captopril group LPs were present in 9 of 63 patients (14%) and in the control
group in 17 of 54 patients (31%) (p = 0.046). There was no difference in the
number of patients with a patent infarct-related artery in the two groups (76 vs.
59%). CONCLUSION: Captopril treatment early after an AMI reduces the incidence of
LPs recorded on Days 6-30 and may thus favorably affect the arrhythmogenic
substrate.
PMID- 10676601
TI - Cardiac autonomic tone and its relation to nonsustained ventricular
tachyarrhythmias in idiopathic dilated cardiomyopathy.
AB - BACKGROUND: In contrast to postinfarct patients, little is known about cardiac
autonomic tone and its relation to spontaneous ventricular tachyarrhythmias in
idiopathic dilated cardiomyopathy (IDC). Both heart rate variability (HRV) and
baroreflex sensitivity (BRS) are indices of autonomic innervation of the heart.
HYPOTHESIS: The aim of the present study was to determine the relation between
cardiac autonomic tone assessed by HRV and BRS and spontaneous nonsustained
ventricular tachycardia (NSVT) on Holter in a large patient population with IDC.
METHODS: 24-h digital Holter recordings including HRV analysis and BRS testing
were prospectively performed in 137 patients with IDC and preserved sinus rhythm.
Mean age was 48 +/- 12 years, and mean left ventricular (LV) ejection fraction
was 32 +/- 9%. The HRV analysis on Holter included the mean RR interval (RRm),
the standard deviation of all normal RR intervals (SDNN), the square root of the
mean of the squared differences between adjacent normal RR intervals (rMSSD), and
the proportion of adjacent normal RR intervals differing more than 50 ms (pNN50).
Testing for BRS was performed noninvasively using the phenylephrine method.
RESULTS: Of 137 study patients, 42 (31%) had spontaneous NSVT on 24-h Holter.
Compared with patients without NSVT, patients with NSVT on Holter had a higher
New York Heart Association (NYHA) functional class (NYHA III: 40 vs. 18%, p <
0.01), a lower ejection fraction (29 +/- 9 vs. 34 +/- 9%, p = 0.01), and an
increased LV end-diastolic diameter (69 +/- 8 mm vs. 66 +/- 7 mm, p = 0.03). The
HRV variables rMSSD, pNN50, RRm, and BRS did not differ significantly between
patients with and without spontaneous NSVT. Only SDNN on Holter was slightly
lower in patients with versus without NSVT (106 +/- 45 vs. 121 +/- 46 ms, p =
0.08). CONCLUSIONS: Patients with IDC and spontaneous NSVT on Holter are
characterized by a higher NYHA functional class, a lower LV ejection fraction, an
increased LV end-diastolic diameter, and a tendency toward a lower SDNN value
compared with patients without NSVT. The remaining measures of HRV including
rMSSD and pNN50 reflecting primarily tonic vagal activity, as well as BRS
reflecting predominantly reflex vagal activity, were similar in patients with and
without NSVT. The prognostic significance of these findings in patients with IDC
is currently under investigation in the Marburg Cardiomyopathy Study (MACAS) at
our institution.
PMID- 10676602
TI - The effect of amlodipine and enalapril on blood pressure and neurohumoral
activation in hypertensive patients with Ribbing's disease (multiple epiphysal
dystrophy).
AB - BACKGROUND: In patients with Ribbing's disease (RD)--a form of multiple epiphysal
dystrophy--hypertension is frequent, often severe, and accompanied by a relevant
cardiac dysfunction. HYPOTHESIS: This study was undertaken to evaluate the
contribution of the calcium antagonist amlodipine and of the angiotensin
converting-enzyme inhibitor enalapril to blood pressure regulation by studying
their effect on neurohormonal activation. METHODS: Fifty hypertensive patients
with RD were studied. After a placebo run-in period of 4 to 6 weeks, patients
were randomly assigned to receive either amlodipine (10 mg once daily) or
enalapril (20 mg once daily) for 6 months. RESULTS: Both drugs significantly
lowered blood pressure. Enalapril did not result in activation of the sympathetic
system (as determined by measurement of the plasma norepinephrine level). On the
other hand, the hypotensive effect of amlodipine occurred with an increase in
heart rate and in the levels of plasma norepinephrine and angiotensin II.
CONCLUSION: It is unclear whether amlodipine may reduce cardiac dysfunction in
patients with RD.
PMID- 10676603
TI - Comparison of left ventricular diastolic filling with myocyte bulk modulus using
Doppler echocardiography and acoustic microscopy in pressure-overload left
ventricular hypertrophy and cardiac amyloidosis.
AB - BACKGROUND: The myocardial bulk modulus has been described as the constitutive
properties of the left ventricular (LV) wall and is measured as rho V2 (rho =
density, V = sound speed) using acoustic microscopy. HYPOTHESIS: The study was
undertaken to assess the relationship between the myocyte bulk modulus and
transmitral inflow patterns in patients with pressure-overload LV hypertrophy
(LVH) and cardiac amyloidosis (AMD). METHODS: In 8 patients with LVH, 8 with AMD,
and 10 controls without heart disease, the transmitral inflow pattern was
recorded by Doppler echocardiography before death, and myocardial tissue
specimens were obtained at autopsy. The tissue density and sound speed in the
myocytes were measured by microgravimetry and acoustic microscopy, respectively.
The diameters of the myocytes were measured on histopathologic specimens stained
by the elastica Van Gieson method. RESULTS: In the subendocardium, the myocyte
bulk modulus was larger in LVH (2.98 x 10(9) N/m2, p < 0.001) and smaller in AMD
(2.61 x 10(9) N/m2, p < 0.001) than in the controls (2.87 x 10(9) N/m2). The
myocyte diameter in LVH (26 +/- 1 microns) was larger than that in the control
(21 +/- 1 microns, p < 0.001) and AMD (20 +/- 1 microns, p < 0.001). The bulk
modulus in the subendocardial myocyte significantly correlated with the
deceleration time (DT) of the early transmitral inflow (r = 0.689, p = 0.028 in
control, r = 0.774, p = 0.024 in LVH, and r = 0.786, p = 0.021 in AMD).
CONCLUSION: The changes in the myocyte elasticity as represented by the bulk
modulus were limited to the subendocardial layers and may be related to
relaxation abnormalities in LVH and a reduction in LV compliance in AMD.
PMID- 10676604
TI - Malpositioned ventricular pacing lead in the left ventricle.
PMID- 10676605
TI - Intercoronary communication between the circumflex and right coronary arteries.
PMID- 10676606
TI - Refractory vasospasm with a malignant course.
AB - We present a patient with two rare disorders, recurrent vasospastic angina
leading to cardiac transplant and acute aortic occlusion. The patient had
recurrent episodes of coronary vasospasm presenting with unstable angina, acute
myocardial infarction, and sudden cardiac death in spite of adequate therapy with
nitrates and calcium-channel blockers. He went on to have a cardiac transplant.
The patient later presented with acute aortic occlusion with concomitant renal
and mesenteric artery spasm. The circumstances of the presentation raise the
possibility of a generalized vasospastic predisposition that is responsible for
both events. Smoking, the only known major risk factor other than
atherosclerosis, was noted to be temporally related to both events in our
patient.
PMID- 10676607
TI - Incomplete ventricular septal rupture following blunt chest trauma.
AB - Nonpenetrating cardiac trauma should be considered in the diagnosis of
electrocardiographic changes after road traffic accidents. Transesophageal
echocardiography is the most useful noninvasive technique for the diagnosis of
cardiac trauma. This paper reports the case of a patient with traumatic contusion
of the ventricular septum following a fall from a 20 m height onto the roof of a
car.
PMID- 10676608
TI - Franz M. Groedel.
PMID- 10676609
TI - Project GRACE (Guidelines for Resuscitation and Care at End-of-life).
PMID- 10676610
TI - Medical futility.
PMID- 10676611
TI - Advance Care Planning. Florida Legislature.
PMID- 10676612
TI - Palliative care.
PMID- 10676613
TI - Summary of Task Forces I, II, and III, and report of Task Force IV Education &
Implementation.
PMID- 10676614
TI - Magnetization transfer imaging of traumatic brain injury.
AB - Magnetization transfer imaging (MTI) has been shown to be sensitive for the
detection of white matter abnormalities in entities such as multiple sclerosis,
progressive multifocal leukoencephalopathy, and wallerian degeneration. Our
hypothesis was that MTI would detect traumatic white matter abnormalities (TWMA)
and provide information additional to that obtainable with routine spin- and
gradient-echo imaging. We hypothesized that the presence of TWMA defined by MTI
would correlate with outcome following TBI. Twenty-eight victims of head trauma
and 15 normal controls underwent magnetic resonance imaging including MTI.
Magnetization transfer ratios (MTR) were calculated for areas of shearing injury
and for normal-appearing white matter (NAWM) in locations frequently subject to
diffuse axonal injury. Abnormal MTRs were detected in NAWM in eight patients. All
eight had persistent neurologic deficits, including cognitive deficits, aphasia,
and extremity weakness. Seven of the 28 patients had no abnormal findings on
neurologic exam at discharge, transfer, or follow-up. None of these patients had
an abnormal MTR in NAWM. In the remaining 13 patients, who had persistent
neurologic deficits, no regions of abnormal MTR were detected in NAWM. MTI is a
sensitive method for the detection of TWMA. Detection of abnormal MTR in NAWM
that is prone to axonal injury may predict a poor patient outcome. The presence
of normal MTR in NAWM in these areas does not necessarily confer a good outcome,
however.
PMID- 10676615
TI - Proton MR spectroscopy in children with acute brain injury: comparison of short
and long echo time acquisitions.
AB - The aim of this study was to evaluate comparatively the information given by
proton magnetic resonance spectroscopy (MRS) with short echo time (TE 20 msec)
stimulated echo acquisition mode and long TE (270 msec) point-resolved
spectroscopy in predicting long-term outcome in children suffering from acute
brain injury. At 1.5 T, we performed single-voxel proton MRS with both methods in
occipital gray matter of 70 children. A linear discriminant analysis used to
predict outcomes based on MRS variables was compared with actual neurologic
outcome assigned at least 6 months after injury by a pediatric neurologist. Using
peak area metabolite ratios and lactate presence, the short and long TE methods
were equally predictive in children over 1 month of age. In neonates less than 1
month of age, the long TE method produced a higher percentage of correct outcome
predictions (91%) than the short TE method (79%). The long TE method detected
lactate more often in all age groups.
PMID- 10676616
TI - Evaluation of intrathecal gadolinium-enhanced MR cisternography in a rabbit model
of traumatic nasoethmoidal CSF fistula.
AB - This pilot study details the feasibility of intrathecal gadopentetate dimeglumine
(Gd) administration in the detection of posttraumatic cerebrospinal fluid (CSF)
fistula in an animal model. Five rabbits were used in this study. An attempt was
made to create a traumatic CSF fistula surgically via a nasal approach. Seven
days following the procedure, images of the cranium in sagittal and coronal
planes were obtained utilizing a 1.9 T magnetic resonance (MR) imaging scanner
before and after intrathecal injection of 16 pmol Gd. Following the imaging
study, the animals were euthanized and grossly sectioned coronally to search for
fistula formation. One animal died on the third day following the surgical
procedure. The other four rabbits underwent the MR and gross pathologic study.
Diagnosis of the fistula by intrathecal Gd-enhanced MR imaging was successful in
two rabbits; this finding was confirmed by gross pathologic examination. No
fistula was detected on either intrathecal Gd-enhanced MR imaging or on
pathologic study in the remaining two rabbits. Intrathecal enhanced MR
cisternography is a potentially promising technique for the evaluation of
posttraumatic CSF fistulae.
PMID- 10676617
TI - Proton magnetic resonance spectroscopy of temporal lobe white matter in patients
with histologically proven hippocampal sclerosis.
AB - The purpose of this study was to assess temporal lobe white matter changes
accompanying hippocampal sclerosis on magnetic resonance (MR) imaging using
single-voxel 1H MR spectroscopy and to strengthen the hypothesis that these white
matter changes are caused by myelin alterations. In 11 patients with
histologically proven hippocampal sclerosis, preoperative coronal fluid
attenuated inversion recovery images were visually assessed by two experienced
neuroradiologists for hippocampal signal increase and size decrease, atrophy of
collateral white matter, and temporal lobe gray/white matter demarcation loss.
Single-voxel 1H MR spectroscopy of the white matter of each anterior temporal
lobe was also performed, excluding the amygdala and hippocampus. The N-acetyl
aspartate (NAA)/choline and NAA/creatine ratios were calculated. In 12 healthy
volunteers both temporal lobes were spectroscopically examined. In all patients
the excised hippocampi were histologically assessed for the presence of
sclerosis, and the excised neocortical temporal lobes were examined for gray and
white matter abnormalities. MRI abnormalities were found on the right in six
patients, on the left in four, and one scan was normal. Hippocampal signal
increase was seen in nine patients, hippocampal size decrease in ten, atrophy of
collateral white matter in nine, and gray/white matter demarcation loss in six. A
significant decrease in the NAA/choline ratio was found in temporal lobe white
matter ipsilateral to the pathologic hippocampus (symptomatic side), compared
with the contralateral, asymptomatic side (P < 0.01), and also compared with
controls (P < 0.001). The ipsilateral NAA/creatine ratio was also significantly
decreased (P < 0.05) compared with the contralateral side and the control
subjects (P < 0.001). Histological examination showed hippocampal sclerosis to a
different degree in all patients. Neither gliosis nor cortical dysplasia was
found in the ipsilateral, symptomatic temporal lobe. Significant decrease in the
mean of NAA/choline ratios is found in temporal lobe white matter of patients
with histologically confirmed hippocampal sclerosis. As this indicates neuronal
loss or dysfunction, the number of axons may be reduced, with associated decrease
in myelin density.
PMID- 10676618
TI - MRA of the abdominal aorta and lower extremities.
AB - Atherosclerotic involvement of the aorta and lower extremity vessels is a common
clinical problem, especially in developed countries. While x-ray angiography has
been the method of choice for preoperative evaluation of patients with
atherosclerotic disease, magnetic resonance angiography (MRA) is emerging as a
powerful noninvasive tool that is capable of providing information critical to
the care of these patients. The objective of this manuscript is to review the
current state-of-the-art of MRA of the abdominal aorta and lower extremity
vessels. The techniques are described, the clinical indications for MRA are
discussed, and the diagnostic accuracy and pitfalls of the various methods are
presented.
PMID- 10676619
TI - Budd-Chiari syndrome: spectrum of appearances of acute, subacute, and chronic
disease with magnetic resonance imaging.
AB - The purpose of this study was to describe our collective experience in the
magnetic resonance (MR) investigation of patients with proven acute, subacute,
and chronic Budd-Chiari syndrome and to demonstrate the spectrum of appearances
on T1- and T2-weighted as well as dynamic post-gadolinium spoiled gradient-echo
imaging. All patients with proven Budd-Chiari syndrome who underwent MR
examinations between June, 1992 and October, 1998 were included in the study.
Fourteen patients were included in the study: four with acute, three with
subacute, three with chronic, and four with acute superimposed on either subacute
(two) or chronic (two) Budd-Chiari syndrome. MR imaging features were
retrospectively evaluated to determine: a) liver morphology, b) pattern of signal
intensity (SI) on T1-weighted images, c) pattern of SI on T2 weighted images, d)
dynamic enhancement characteristics, e) presence or absence of visible venous
thrombosis, and f) presence or absence of venous macroscopic collaterals. The MR
findings were correlated with surgical, histopathological, and laboratory data to
determine imaging characteristics related to the chronicity of the disease
process. Hepatic venous thrombosis or absence of hepatic venous flow was
demonstrated in all patients in the study. In the four patients with acute Budd
Chiari syndrome, the liver periphery was moderately low signal on T1 and
moderately high signal on T2-weighted images relative to the central liver; both
early and late gadolinium-enhanced images revealed diminished peripheral
enhancement. In the three patients with subacute Budd-Chiari syndrome, the liver
periphery was moderately low signal on T1, and moderately high signal on T2
weighted images, while early and late gadolinium-enhanced images revealed
heterogenously increased enhancement within the liver periphery. In the three
patients with chronic Budd-Chiari syndrome, the SI differences between peripheral
and central liver were minimal on T1- and T2-weighted images, and enhancement
differences were also minimal. Extensive bridging intrahepatic and capsular
venous collaterals were visualized in chronic cases. In the four patients with
acute Budd-Chiari syndrome superimposed on more chronic disease, a combination of
gadolinium enhancement patterns was observed on MR images. Enhancement patterns
between central and peripheral liver were different for acute, subacute, and
chronic Budd-Chiari syndromes, suggesting differentiation between these phases of
the disease process. Application of this pattern approach permitted recognition
of acute changes superimposed on more chronic disease.
PMID- 10676620
TI - Polyposis syndromes of the gastrointestinal tract: MR findings.
AB - We describe the magnetic resonance (MR) findings in patients with
gastrointestinal polyposis syndromes using breath-hold T1-weighted sequences,
both standard and with fat suppression, prior to and following gadolinium
administration, and breathing-independent single-shot half-Fourier RARE T2
weighted sequences. Six patients with gastrointestinal polyposis syndromes
underwent MR examination to investigate for the presence of metastatic disease.
The appearances of the gastrointestinal polyps on noncontrast T1-weighted spoiled
gradient-echo (SGE), T2-weighted (half-Fourier RARE) images, and early and late
gadolinium-enhanced SGE images were determined. Other gastrointestinal findings
and extragastrointestinal disease were also evaluated. Patients with the
following gastrointestinal polyposis syndromes were included: familial polyposis
(n = 3), Peutz-Jeghers syndrome (n = 1), Gardner's syndrome (n = 1), and
neurofibromatosis (n = 1). Polypoid lesions in all patients exhibited signal
intensity comparable to bowel on noncontrast images and enhanced similar to bowel
on early and late gadolinium-enhanced images. Polyps larger than 2 cm, observed
in one patient with familial polyposis and the patient with Gardner's disease,
showed mild heterogeneity on late gadolinium-enhanced fat-suppressed images.
Multiple colonic polyps ranging from 5 mm to 3 cm in diameter were observed in
patients with familial adenomatous polyposis. A solitary 1.5 cm polyp associated
with entero-enteric intussusception was observed in the patient with Peutz
Jeghers syndrome. Gastric polyps ranging from 5 mm to 6 cm were observed in the
stomach of the patient with Gardner's syndrome. Duodenal and jejunal
neurofibromas ranging from 1 to 2 cm in diameter were present in the patient with
neurofibromatosis. Extra gastrointestinal findings included an adrenal adenoma (1
patient), a pheochromocytoma (1 patient), and liver metastases (2 patients).
Gastrointestinal polyps in patients with polyposis syndromes may be visualized on
MR images employing breath-hold T1-weighted and breathing-independent snapshot T2
weighted techniques. Appreciation of polyp enhancement on post-gadolinium images
is an important finding, which should help distinguish polyps from bowel
contents.
PMID- 10676621
TI - Comparison of short inversion time inversion recovery (STIR) and fat-saturated
(chemsat) techniques for background fat intensity suppression in cervical and
thoracic MR imaging.
AB - The purpose of this study was to compare short inversion time inversion recovery
(STIR) fast spin-echo (FSE), and fat-saturated T2-weighted FSE sequences in terms
of uniformity of fat suppression and lesion conspicuity for magnetic resonance
(MR) imaging of the neck and thorax. STIR FSE and fat-saturated T2-weighted FSE
images were scored for uniformity of fat suppression (n = 40) and lesion
conspicuity (n = 35). Five-point rank score analyses were utilized by three
experienced radiologists. The mean scores of STIR and fat-saturated FSE
techniques for uniformity of fat suppression were 4.3 and 2.3, respectively (P <
0.0001). The mean scores of STIR and fat-saturated FSE techniques for lesion
conspicuity were 4.2 and 3.5, respectively (P < 0.0001). Insufficient fat
suppression was prominent in the mandible, supraclavicular region, anterior
mediastinum, epipericardial fat, and subdiaphragmatic fat. In addition, fat
saturated T2-weighted FSE showed inadvertent water suppression in 25%. The STIR
FSE technique was superior to the fat-saturated FSE technique for cervical and
thoracic MR imaging.
PMID- 10676622
TI - Statistical analysis of multi-subject fMRI data: assessment of focal activations.
AB - A simple procedure for analyzing multi-subject functional magnetic resonance
imaging (fMRI) data is proposed. In the first step, a voxel-wise t-test across
standardized z-maps is performed to identify areas that are consistently
activated across subjects. In the second step, for each area, individual mean z
scores are calculated and subsequently subjected to an analysis of variance. An
example is provided.
PMID- 10676623
TI - 3D gadolinium-enhanced MRA: evaluation of hepatic vasculature in children with
hepatoblastoma.
AB - We used contrast-enhanced three-dimensional magnetic resonance angiography (3D
MRA) modified for pediatric use to evaluate the hepatic vasculature prior to
partial hepatectomy in five consecutive children with hepatoblastoma.
Modifications included non-breath-hold technique in four of the five children who
were sedated. The single breath-hold technique was performed in only one awake
child. Scan delay times were based on contrast infusion time rather than total
infusion time. The hepatic artery, portal vein, and inferior vena cava were
identified in all patients. MRA findings were confirmed by conventional
angiography in one patient and by surgery in all. Contrast-enhanced 3D MRA is a
useful and rapid technique prior to partial hepatectomy in patients with
hepatoblastoma.
PMID- 10676624
TI - Comparison of artifacts produced from carbon fiber and titanium alloy needles at
1.5 T MR imaging.
AB - A novel coaxial carbon fiber-based biopsy needle set was investigated in phantom
experiments and compared with a commercially available, magnetic resonance (MR)
compatible titanium alloy set using MR imaging at 1.5 T. Image artifacts observed
with different MR sequences were assessed. It was found that the carbon fibers
produced distinctly smaller image artifacts compared with the titanium needle.
Depending on the type of MR sequence, the relative range of artifact size ratios
between the carbon and titanium needles was between 0.7 (spin-echo sequence) and
0.4 (gradient-echo sequence) with the needles oriented perpendicular to the main
magnetic field. Carbon fiber composites are promising materials for the design
and construction of MR-compatible instruments.
PMID- 10676625
TI - Induction of apoptotic cell death and in vivo growth inhibition of human cancer
cells by a saturated branched-chain fatty acid, 13-methyltetradecanoic acid.
AB - A saturated branched-chain fatty acid, 13-methyltetradecanoic acid (13-MTD), was
purified from a soy fermentation product, which was used by many cancer patients
as a treatment supplement. Our preliminary study indicated that 13-MTD could
induce cell death in human cancer cell lines K-562, MCF7, DU 145, NCI-SNU-1, SNU
423, NCI-H1688, BxPC3, and HCT 116. The ID50 dosage of 13-MTD for these tumor
cells ranged from 10 to 25 microg/ml. Further investigation revealed that 13-MTD
caused tumor cell death through rapid induction of apoptosis, which could be
detected 2 h after the treatment of tumor cells with 13-MTD. Xenograft tumors of
prostate carcinoma cell line DU 145 and hepatocarcinoma LCI-D35 were
orthotopically implanted into nude mouse prostate and liver, respectively. 13-MTD
was administered p.o. once daily to the implanted mice for approximately 40 days.
Our results showed that 13-MTD could effectively inhibit the growth of orthotopic
tumor implants of both cell lines compared with control groups. The average
inhibition rate was 84.6% for DU 145 and 65.2% for LCI-D35 (P < 0.01). LD50 test
results showed that mice could well sustain the oral feeding of 5 g/kg/day
without observable anomaly. Our preliminary data demonstrated that 13-MTD could
effectively inhibit in vitro and in vivo growth of various cancer cell lines by
inducing apoptosis without significant toxic side effects, suggesting 13-MTD as a
potential candidate for chemotherapy of human cancers.
PMID- 10676626
TI - Expression of a highly conserved protein, p27BBP, during the progression of human
colorectal cancer.
AB - The highly conserved protein p27BBP is a cytoplasmic interactor of integrin beta4
expressed in epithelia. p27BBP is found in two pools: one nuclear pool enriched
in the perinucleolar region, and one cytoplasmic pool. Deletion of p27BBP in
yeast is lethal as a result of loss of the ribosomal 60S subunit. The aim of this
study was to investigate the distribution of p27BBP in gut epithelium and its
behavior during progression of human colorectal carcinomas. Results indicated
that p27BBP is high in rapidly cycling cells and decreased in villous cells
committed to apoptotic cell death. In dysplastic adenomas and carcinomas, p27BBP
displayed a large increase of its nucleolar component that was superimposable to
argyrophylic nucleolar organizing region-associated proteins and was associated
with the nuclear matrix. Western blotting confirmed increased p27BBP in
dysplastic adenomas and in carcinomas. In particular, p27BBP increased
progressively from adenomas to carcinomas and, in the latter, was related to the
tumor stage. The overexpression of p27BBP corresponded to mRNA up-regulation in
carcinomas, supporting the idea of transcriptional or post-transcriptional
regulation of its expression. Results suggested that p27BBP alterations are an
early event in the transition from benign to malignant colorectal phenotypes and
provide a novel tool in surgical pathology.
PMID- 10676627
TI - p53-dependent global genomic repair of benzo[a]pyrene-7,8-diol-9,10-epoxide
adducts in human cells.
AB - The global genomic repair of DNA adducts formed by the human carcinogen (+/-)
anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) has been studied by 32P
postlabeling in human fibroblasts in which p53 expression can be regulated. At
low BPDE adduct levels (10-50 adducts/10(8) nucleotides), repair was rapid and
essentially complete within 24 h in p53+ cells, whereas no repair was detected
within 72 h in similarly treated p53- cells. At 10-fold higher BPDE adduct
levels, repair under both conditions was rapid up to 8 h, after which a low level
of adducts persisted only in p53- cells. These results demonstrate a dependence
on p53 for the efficient repair of BPDE adducts at levels that are relevant to
human environmental exposure and, thus, have significant implications for human
carcinogenesis.
PMID- 10676628
TI - High frequency of K-ras mutations in biliary duct carcinomas of cases with a long
common channel in the papilla of Vater.
AB - The frequency of K-ras mutation in biliary duct carcinomas in different locations
and the relationship to the form of the junction of the pancreaticobiliary duct
(JPBD) are not understood clearly. These points were investigated in the present
study. Thirty-seven biliary duct carcinomas in patients without anomalous JPBD
were investigated for K-ras mutations. Regarding location, 12 were hilar, 4 in
the upper, 11 in the middle, and 10 in the lower portion of the duct.
Furthermore, with 14 cases for which the form of the JPBD could be confirmed by
endoscopic retrograde cholangiopancreatography or postoperative
cholangiopancreatography, division was made into two types: those with a long
common channel (>5 mm) in the papilla of Vater (type 1, n = 4), and the other
with a shorter or nonapparent common channel (type 2, n = 10). The overall
frequency of K-ras mutation was 30%, the incidence gradually increasing from
upper to lower regions. K-ras mutations were significantly more frequent in
biliary duct carcinomas associated with long common channels (P < 0.05). These
results suggest that a long common channel may bear a relation to K-ras mutations
in biliary duct carcinogenesis, presumably through its influence on pancreatic
juice regurgitation.
PMID- 10676629
TI - Photofrin photodynamic therapy can significantly deplete or preserve oxygenation
in human basal cell carcinomas during treatment, depending on fluence rate.
AB - At high fluence rates in animal models, photodynamic therapy (PDT) can
photochemically deplete ambient tumor oxygen through the generation of singlet
oxygen, causing acute hypoxia and limiting treatment effectiveness. We report
that standard clinical treatment conditions (1 mg/kg Photofrin, light at 630 nm
and 150 mW/cm2), which are highly effective for treating human basal cell
carcinomas, significantly diminished tumor oxygen levels during initial light
delivery in a majority of carcinomas. Oxygen depletion could be found during at
least 40% of the total light dose, but tumors appeared well oxygenated toward the
end of treatment. In contrast, initial light delivery at a lower fluence rate of
30 mW/cm2 increased tumor oxygenation in a majority of carcinomas. Laser
treatment caused an intensity- and treatment time-dependent increase in tumor
temperature. The data suggest that high fluence rate treatment, although
effective, may be inefficient.
PMID- 10676630
TI - Differences in estrogen receptor alpha variant messenger RNAs between normal
human breast tissue and primary breast carcinomas.
AB - We evaluated the differences in prevalence and functional activity of human
estrogen receptor alpha (hER) variant mRNA between 21 normal breast tissues and
41 primary breast carcinomas using a functional assay in yeast for the hER First,
we found that the presence of wild-type hER, relative to the total amount of hER,
differs markedly (P < 0.0001) between normal breast tissue (median, 85% wild-type
hER) and breast tumors (median, 74% wild-type hER). Second, the hER variants with
altered function that are present in normal breast tissue are mainly one-exon
deleted splicing variants (median, 100%), whereas in breast tumors only half of
all variants lack just one single exon (median, 50%; P < 0.0001). Our results
suggest that hER-dependent estrogen responsiveness of breast tissue may change
during tumor outgrowth, indicating that specific hER variants may play a role in
breast cancer development or progression.
PMID- 10676631
TI - High-activity microsomal epoxide hydrolase genotypes and the risk of oral,
pharynx, and larynx cancers.
AB - Human microsomal epoxide hydrolase (mEH), encoded by the EPHX1 gene, is involved
in the metabolism of tobacco carcinogens. We investigated the effect of exon 3
and 4 polymorphisms of the EPHX1 gene in 121 patients with cancers of the oral
cavity/pharynx, 129 patients with cancer of the larynx, and 172 non-cancer
controls, all Caucasian regular smokers. The potential modifying role of
previously analyzed GSTM1, GSTM3, and GSTP1 genotypes was also examined. Compared
with the putative low-activity genotypes, odds ratios (ORs) associated with
predicted intermediate and high mEH activity genotypes were significantly
increased for oropharyngeal cancers [OR = 1.8; 95% confidence interval (CI) = 1.0
3.3; and OR = 2.1; 95% CI = 1.0-4.5, respectively; P(trend) = 0.03] and laryngeal
cancers (OR = 1.7; 95% CI = 1.0-3.1; and OR = 2.4; 95% CI = 1.1-5.1,
respectively; P(trend) = 0.02). Moreover, a positive interaction was found
between mEH activity and GSTM3 genotype for laryngeal cancer. The combined EPHX1
high activity-associated genotype and GSTM3 (AB or BB) genotype conferred a 13.1
fold risk (95% CI = 3.5-48.4) compared with the concurrent presence of the EPHX1
low activity-associated genotype and the GSTM3 AA genotype. Thus, EPHX1
polymorphisms may be one of the factors of importance in susceptibility to
smoking-related cancers of the upper aerodigestive tract.
PMID- 10676632
TI - Methylation of the human telomerase gene CpG island.
AB - The acquisition of expression of hTERT, the catalytic subunit of the telomerase
enzyme, seems to be an essential step in the development of a majority of human
tumors. However, little is known about the mechanisms preventing telomerase gene
expression in normal and transformed cells that do not express hTERT. Using a
methylation-specific PCR-based assay, we have found that the CpG island
associated with the hTERT gene is unmethylated in telomerase-negative primary
tissues and nonimmortalized cultured cells, indicating that mechanisms
independent of DNA methylation are sufficient to prevent hTERT expression. The
hTERT CpG island is methylated in many telomerase-negative and telomerase
positive cultured cells and tumors, but the extent of methylation did not
correlate with expression of hTERT. Demethylation of DNA with 5-azacytidine in
two cell lines induced expression of hTERT, suggesting that DNA methylation can
contribute to hTERT repression in some cells. Together, these data show that the
hTERT CpG island can undergo cytosine methylation in cultured cells and tumors
and that DNA methylation may contribute to the regulation of the hTERT gene, but
that CpG island methylation is not responsible for repressing hTERT expression in
most telomerase-negative cells.
PMID- 10676633
TI - Constitutive activation of cyclin B1-associated cdc2 kinase overrides p53
mediated G2-M arrest.
AB - Recent studies have suggested that p53 regulates the G2 checkpoint in the cell
cycle and that this function is required for the maintenance of genomic
integrity. In this study, we investigated a regulatory role of p53 specifically
in G2-M transition. Human bladder carcinoma cells lacking functional p53 were
synchronized at G1-S, which is preceded by p53-mediated G1 arrest. p53 expression
in the synchronized cells was induced by infection with a recombinant adenovirus
that encodes p53. After release from the G1-S arrest, the cells progressed to S
phase and G2 but failed to enter mitosis. Biochemical analysis showed that p53
inhibits cell cycle-dependent expression of cdc2 and cyclin B1 and consequently
inhibits cdc2 kinase. The role of cyclin B1-associated cdc2 kinase in p53
mediated G2-M arrest was further investigated by expression of both cyclin B1 and
cdc2AF, in which inhibitory phosphorylation sites were substituted. The cells
expressing both cdc2AF and cyclin B1 showed a constitutive activation of cdc2
kinase during cell cycle progression and passed through G2-M regardless of p53
expression. Therefore, inactivation of cdc2 kinase through cdc2 and cyclin B1
repression is an essential step in p53-mediated G2-M arrest.
PMID- 10676634
TI - No evidence of Peutz-Jeghers syndrome gene LKB1 involvement in left-sided
colorectal carcinomas.
AB - LKB1 serine/threonine kinase is a gene for Peutz-Jeghers cancer predisposition
syndrome. Most studies have detected a low frequency of LKB1 defects in sporadic
cancer. A notable exception is a recent report describing frequent, mostly
missense type, LKB1 mutations in Korean distal colorectal tumors. To clarify the
role of LKB1 in colon cancer, we scrutinized 50 left-sided Korean and Finnish
specimens. No somatic mutations were found. The seven Korean somatic missense
mutations reported previously were functionally analyzed, and five were found not
to alter LKB1 kinase activity. One of these changes was found to be a germ-line
polymorphism. LKB1 involvement in distal colorectal cancer is not common.
PMID- 10676635
TI - Genomic imbalances including amplification of the tyrosine kinase gene JAK2 in
CD30+ Hodgkin cells.
AB - Comparative genomic hybridization was applied for a comprehensive screening of
frequently occurring net gains and losses of chromosomal subregions in small
populations of CD30+ Hodgkin cells and their morphological variants. In 12
Hodgkin's lymphomas, recurrent gains were detected on chromosomal arms 2p, 9p,
and 12q (in six, four, and five tumors, respectively) and distinct high-level
amplifications were identified on chromosomal bands 4p16, 4q23-q24, and 9p23-p24.
In Hodgkin cells with 9p23-p24 amplification, fluorescence in situ hybridization
revealed an increased copy number of chromosomal sequences spanning the tyrosine
kinase gene JAK2. Several of the imbalances described, in particular a gain in
chromosomal arm 9p that includes JAK2 amplification, are similar to the genomic
changes detected in primary mediastinal B-cell lymphoma.
PMID- 10676636
TI - Regulation of tumor necrosis factor-related apoptosis-inducing ligand sensitivity
in primary and transformed human keratinocytes.
AB - Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to
exert potent cytotoxic activity against many tumor cell lines but not against
normal cells. It has been hypothesized that this difference in TRAIL sensitivity
between normal and transformed cells might be due to the expression of the non
death-inducing TRAIL receptors (TRAIL-R) TRAIL-R3 and TRAIL-R4, presumably by
competition for limited amounts of TRAIL. To assess the regulation of resistance
versus sensitivity to TRAIL in primary as well as transformed keratinocytes, we
examined TRAIL sensitivity, TRAIL receptor expression, and intracellular
signaling events induced by TRAIL. Although TRAIL induced apoptosis in primary as
well as transformed keratinocytes, a marked difference in sensitivity could be
observed with primary keratinocytes (PK) being 5-fold less sensitive to TRAIL
than transformed keratinocytes (TK). Yet both cell types exhibited similar TRAIL
receptor surface expression, suggesting that expression of TRAIL-R3 and TRAIL-R4
may not be the main regulator of sensitivity to TRAIL. Biochemical analysis of
the signaling events induced by TRAIL revealed that PK could be sensitized for
TRAIL and, similarly, for TRAIL-R1- and TRAIL-R2-specific apoptosis by
pretreatment of the cells with cycloheximide (CHX). This sensitization
concomitantly resulted in processing of caspase-8, which did not occur in TRAIL
resistant PK. These data indicate that an early block of TRAIL-induced apoptosis
was present in PK compared with TK or PK treated with CHX. Interestingly,
cellular FLICE inhibitory protein (cFLIP) levels, high in PK and low in TK and
several other squamous cell carcinoma cell lines, decreased rapidly after
treatment of PK with CHX, correlating with the increase in TRAIL sensitivity and
caspase-8 processing. Furthermore, ectopic expression of cFLIP long (cFLIP(L)) in
TK by transfection with a cFLIP(L) expression vector resulted in resistance to
TRAIL-mediated apoptosis of these cells. Thus, our results demonstrate that TRAIL
sensitivity in PK is primarily regulated at the intracellular level rather than
at the receptor level.
PMID- 10676637
TI - Down-regulation of HER2/neu expression induces apoptosis in human cancer cells
that overexpress HER2/neu.
AB - The HER2/neu oncogene is overexpressed in a significant fraction of human tumors;
such overexpression is thought to play a role in the aberrant proliferation of
cancer cells. The effects of HER2/neu-specific phosphorothioate antisense
oligodeoxyribonucleotides on HER2/neu expression, tumor cell proliferation, and
activation of apoptotic cell death pathways have been examined. Antisense
treatment down-regulates HER2/neu expression in a dose-dependent and sequence
specific manner. HER2/neu antisense treatment specifically inhibits the growth of
tumor lines that overexpress HER2/neu, but it has little effect on the growth of
tumor cells that express low levels of HER2/neu. Down-regulation of HER2/neu
expression is not only cytostatic, but it also results in the activation of
apoptotic cell death pathways in cells that overexpress HER2/neu. These results
suggest that, in addition to stimulating tumor cell proliferation, HER2/neu
overexpression in cancer cells acts as an antiapoptotic cell survival factor.
PMID- 10676638
TI - An indolocarbazole inhibitor of human checkpoint kinase (Chk1) abrogates cell
cycle arrest caused by DNA damage.
AB - Many cancer therapies cause DNA damage to effectively kill proliferating tumor
cells; however, a major limitation of current therapies is the emergence of
resistant tumors following initial treatment. Cell cycle checkpoints are involved
in the response to DNA damage and specifically prevent cell cycle progression to
allow DNA repair. Tumor cells can take advantage of the G2 checkpoint to arrest
following DNA damage and avoid immediate cell death. This can contribute to
acquisition of drug resistance. By abrogating the G2 checkpoint arrest, it may be
possible to synergistically augment tumor cell death induced by DNA damage and
circumvent resistance. This requires an understanding of the molecules involved
in regulating the checkpoints. Human Chk1 is a recently identified homologue of
the Schizosaccharomyces pombe checkpoint kinase gene, which is required for G2
arrest in response to DNA damage. Chk1 phosphorylates the dual specificity
phosphatase cdc25C on Ser-216, and this may be involved in preventing cdc25 from
activating cdc2/cyclinB and initiating mitosis. To further study the role of Chk1
in G2 checkpoint control, we identified a potent and selective indolocarbazole
inhibitor (SB-218078) of Chk1 kinase activity and used this compound to assess
cell cycle checkpoint responses. Limited DNA damage induced by gamma-irradiation
or the topoisomerase I inhibitor topotecan was used to induce G2 arrest in HeLa
cells. In the presence of the Chk1 inhibitor, the cells did not arrest following
gamma-irradiation or treatment with topotecan, but continued into mitosis.
Abrogation of the damage-arrest checkpoint also enhanced the cytotoxicity of
topoisomerase I inhibitors. These studies suggest that Chk1 activity is required
for G2 arrest following DNA damage.
PMID- 10676639
TI - Quantitative analysis of interindividual variation of glutathione S-transferase
expression in human pancreas and the ambiguity of correlating genotype with
phenotype.
AB - Analysis of glutathione S-transferases (GSTs) of the alpha, mu, and pi classes by
reverse-phase high-performance liquid chromatography and electrospray-ionization
mass spectrometry in 43 samples of normal human pancreas demonstrated a wide
variation in expression of subunits P1, A1, A2, A4, M1, M2, and M3 and the
presence of a novel form designated GST "A5." GSTA2 consisted of three forms that
were differentially expressed between individuals in a manner consistent with
allelic polymorphism at the hGSTA2 locus. Expression, in terms of microg GST
subunit/mg cytosolic protein, varied by 6-15-fold for subunits P1, A2, and M3 and
17-30-fold in the case of GSTs A1 and M2. Less consistently expressed were GSTs
M1a, M1b, A4, and A5. Among these, GSTM1 expression (excluding M1-null samples)
varied 12-fold between samples, whereas GST A4 and A5 expression varied
approximately 50-100-fold between samples, well beyond the range of other
subunits, suggesting that their expression is highly inducible. Linear
correlations (P < 0.001-0.003) existed between levels of the most consistently
expressed GST, GSTP1, and total GSTs, GSTA2 and M3, and in GSTM1-positive
samples, between GSTM1, M3, and P1. The correlation between GST subunits P1 and
M3 was bimodal according to M1 genotype, reflecting the presence of the
regulatory element in hGSTM3*B that is linked with the hGSTM1*A genotype. It is
concluded that although a degree of regulation of expression of GSTs occurs in
human pancreas, the variability of phenotype is high and might obscure the
effects of genetic polymorphisms on individual cancer susceptibility.
Interindividual variation of GST expression is, therefore, a factor that should
be taken account of in epidemiological studies.
PMID- 10676640
TI - Differentiation of rat oval cells after activation of peroxisome proliferator
activated receptor alpha43.
AB - Peroxisome proliferators (PPs) act as nongenotoxic tumor promoters in rodents.
Their hepatocarcinogenicity requires the presence of the PP-activated receptor
alpha (PPARalpha); however, the exact role played by this transcription factor in
the liver, more precisely in liver cell growth and differentiation, is not known.
The aim of this study was to investigate the role of PPARalpha in oval cells,
which are considered to be closely related to liver stem cells, act as
bipotential progenitors for the two main hepatic lineages, and have been
implicated as playing a role in several models of liver carcinogenesis. We
studied the PPARalpha-mediated response of primary oval cells isolated from rats
fed a choline-deficient ethionine-supplemented diet (CDE diet, a regimen commonly
used for the induction of oval cell proliferation in rodents) with or without
cotreatment with WY14,643, a prototype PPARalpha-activator. PPARalpha was
expressed at relatively low levels in primary oval cells from rats fed the CDE
diet alone. In vivo treatment with WY14,643 for 2-6 weeks induced, in the oval
cells, the expression of PPARalpha as well as that of the PPARalpha-responsive
genes encoding fatty acyl-CoA oxidase and cytochrome P450 4A1. Moreover, the oval
cell response to WY14,643 was accompanied by an overall phenotypic modulation
toward the hepatocyte lineage. In addition, the PPARalpha activator induced,
among the oval cells, a subpopulation of transitional cells showing features of
maturing hepatocytes expressing the oncofetal marker, alpha-fetoprotein. These
results show that oval cells are responsive to PPs and strongly argue for a role
of PPARalpha in the differentiation/maturation of rat oval cells. In the absence
of the CDE diet regimen, 9-week treatment with WY14,643 lead to the appearance of
a population of large-sized cells somewhat similar to the transitional cells.
However, these cells showed little expression of markers of mature hepatocytes,
consistent with a block during their maturation process, i.e., they are resistant
to PPARalpha-mediated differentiation. Interestingly, the phenotype of these
cells resembled that of the cells usually found in neoplastic foci induced by
PPs. Our results, together with previous reports, suggest the involvement of oval
cells in the hepatocarcinogenicity of PPs.
PMID- 10676641
TI - Single-site methylation within the p53 promoter region reduces gene expression in
a reporter gene construct: possible in vivo relevance during tumorigenesis.
AB - It is not known whether transcriptional suppression by de novo methylation occurs
within the promoter region of the p53 gene during multistage tumorigenesis. To
address this question, in vivo alterations in the CpG methylation within the rat
p53 promoter region were evaluated in control, preneoplastic, and tumor tissue
during tumor progression using the folate/methyl-deficient model of
hepatocarcinogenesis. Alterations in CpG methylation were found to be site
specific and to vary depending on the stage of carcinogenesis. To further explore
the effect of site-specific methylation on p53 promoter activity, reporter gene
constructs were prepared containing specifically methylated sites within the p53
promoter region, and the transcriptional activity in cultured mammalian cells was
determined in a transient transfection assay. Relative to the unmethylated
construct as a positive control, single-site methylation at nucleotide (nt) -450,
which occurs 216 nt upstream from the 85-nt minimal promoter region, suppressed
promoter activity by 85%. In contrast, single-site methylation at nt -179, which
occurs within the minimal essential promoter region, suppressed activity by only
20%. The p53 promoter constructs containing the singly methylated CpG site at nt
450 were then reevaluated for processive changes in methylation status 48 h after
transfection, during maximum suppression of promoter activity. Restriction
analysis with methylation-sensitive enzymes revealed that de novo methylation had
occurred after transfection at previously unmethylated sites. These findings
suggest that nt -450 may constitute a critical site for initiation of de novo
methylation and processive spreading of methylation associated with
transcriptional inactivation of the p53 gene. Furthermore, the results suggest a
possible alternative mechanism for the silencing of the p53 gene in tumors that
do not have p53 mutations.
PMID- 10676642
TI - Transgenic mice overexpressing protein kinase C epsilon in their epidermis
exhibit reduced papilloma burden but enhanced carcinoma formation after tumor
promotion.
AB - To determine the role that protein kinase C epsilon (PKCepsilon) may play in skin
growth, differentiation, and tumor promotion, transgenic mice were generated that
overexpressed an epitope-tagged protein kinase C epsilon (T7-PKCepsilon) in their
epidermis using the human keratin 14 promoter. Three independent mouse lines that
overexpressed the T7-PKCepsilon in their epidermis were produced. The three
independent lines 206, 224, and 215 exhibited a 3-, 6-, and 18-fold elevation,
respectively, in the level of PKCepsilon immunoreactive protein. Line 215
exhibited a 19-fold greater phosphatidylserine and 12-O-tetradecanoylphorbol-13
acetate (TPA) stimulated kinase activity than line 224. Line 206 exhibited a low
basal T7-PKCepsilon activity, which failed to be stimulated by phosphatidylserine
and TPA. All of the line 215 transgenic mice (F0 to the F2 generation) displayed
phenotypic changes in the skin. The phenotypic changes progressed gradually,
starting around 4-5 months of age, with mild dryness of the tail accompanied by
hair loss and inflammation at the base of the tail. Hyperproliferation and
ulceration of the affected regions were observed around 7-8 months of age. The
hyperproliferative epidermis from the affected regions exhibited an expansion of
the suprabasal epidermal cells. Inflammation and/or ulceration were also observed
in the dorsal skin, the ears, and around the eyes. The line 215 mice, which
expressed the highest level of PKCepsilon, were evaluated for sensitivity to
mouse skin tumor promotion by TPA. Tumors were elicited by the initiation (7,12
dimethylbenz[a]anthracene, 100 nmol)-promotion (TPA, 5 nmol/twice weekly)
protocol. The papilloma burden was reduced by 95-96% for male and female T7
PKCepsilon mice compared to wild-type controls. However, carcinomas developed
rapidly in the T7-PKCepsilon mice treated with 7, 12-dimethylbenz[a]anthracene
and TPA. These carcinomas appeared to form independently of prior papilloma
development. These results demonstrate that PKCepsilon is an important regulator
of skin tumor development.
PMID- 10676643
TI - Cell proliferation induced by triiodothyronine in rat liver is associated with
nodule regression and reduction of hepatocellular carcinomas.
AB - Previous studies have demonstrated that short-term treatment with peroxisome
proliferators decreased the size and number of gamma-glutamyl transpeptidase or
placental glutathione S-transferase (GSTP)-positive hepatic hyperplastic lesions.
In this study, we have examined the effect of the hormone triiodothyronine (T3),
which, similarly to peroxisome proliferators, is a strong liver mitogen and a
ligand of nuclear receptors, on the growth of GSTP-positive nodules generated by
the resistant hepatocyte model and on the development of hepatocellular
carcinoma. Hepatic hyperplastic nodules were induced in male Fischer rats by a
single dose (150 mg/kg) of diethylnitrosamine, followed by a 2-week exposure of
the animals to 2-acetylaminofluorene and partial hepatectomy. Nine weeks after
diethylnitrosamine administration, rats were switched to a diet containing 4
mg/kg T3 for 1 week (experiment 1) and sacrificed during T3 feeding or were
exposed to seven cycles of T3-supplemented diet (1 week/month per 7 months), and
sacrificed 6 months after the last cycle (experiment 2). Results showed that T3
treatment for 1 week caused a 70% reduction in the number of GSTP-positive
nodules (14/cm2 in T3-fed rats versus 44/cm2 of control animals), as well as GSTP
positive area (12% versus 43% of controls). Reduction in the number of GSTP
positive nodules observed 1 week after T3 feeding was associated with a strong
increase in the labeling index of enzyme-altered nodules compared with that of
controls (labeling index was 64 and 31%, respectively). No significant
differences in the apoptotic index were observed between the two groups. Results
from experiment 2 did reveal that although rats treated with diethylnitrosamine +
2-acetylaminofluorene developed 100% hepatocellular carcinoma and 33% of them
showed lung metastasis, only 50% of rats exposed to repeated cycles of
triiodothyronine developed hepatocellular carcinoma with no lung metastasis. This
study indicates that cell proliferation per se might not necessarily represent a
promoting condition for putative preneoplastic lesions and demonstrates an
anticarcinogenic effect of T3.
PMID- 10676644
TI - Telomerase activity and telomere length in acute and chronic leukemia, pre- and
post-ex vivo culture.
AB - We studied telomerase regulation and telomere length in hematopoietic progenitor
cells from peripheral blood and bone marrow from patients with acute and chronic
leukemia and myeloproliferative diseases. CD34+ cells from a total of 93 patients
with either acute myeloid leukemia (AML; n = 25), chronic myeloid leukemia (CML;
n = 21), chronic lymphocytic leukemia (CLL; n = 18), polycythemia vera (PV; n =
16), or myelodysplastic syndromes (MDS; n = 13) were analyzed before and in 19
patients after ex vivo expansion in the presence of multiple cytokines (kit
ligand, interleukin-3, interleukin-6, and granulocyte colony-stimulating factor
plus erythropoietin). Compared with hematopoietic progenitor cells from normal
donors (n = 108), telomerase activity (TA) was increased 2- to 5-fold in chronic
phase (CP)-CML, CLL, PV, and MDS. In AML, accelerated phase (AP) and blastic
phase (BP)-CML, basal TA was 10- to 50-fold higher than normal. TA of CP-CML
CD34+ cells was up-regulated within 72 h of ex vivo culture, peaked after 1 week,
and decreased below detection after 2 weeks. In contrast, TA in AP/BP-CML and AML
CD34+ cells was down-regulated after 1 week of culture and decreased further
thereafter. The expansion potential of CD34+ cells from patients with leukemia
was considerably decreased compared with CD34+ cells from normal donors. The
average expansion of cells from leukemic individuals was 6.5-, 2.3-, 0.6-, and
0.2-fold in weeks 1, 2, 3, and 4, respectively, whereas expansion of normal cells
was 5- to 15-fold higher. In serial expansion culture, a median telomeric loss of
0.7 kbp was observed during 3-4 weeks of expansion. Our results demonstrate that
up-regulation of telomerase is similar in CD34+ cells from CP-CML, CLL, PV, and
MDS patients and in normal hematopoietic cells during the first week of culture,
whereas in AML and AP/BP-CML, telomerase is high at baseline and down-regulated
during expansion culture. High levels of telomerase in leukemic progenitors at
baseline may be a feature of both the malignant phenotype and rapid cycling.
Telomerase down-regulation during culture of leukemic cells may be due to the
decreased expansion potential or repression of normal hematopoiesis, or in AML it
may be due to the partial differentiation of AML cells, shown previously to be
associated with loss of TA. Telomere shortening during ex vivo expansion
correlated with low levels of TA, particularly in chronic leukemic and MDS
progenitors where telomerase was insufficient to protect against telomere bp loss
during intense proliferation.
PMID- 10676645
TI - Altered hepatic gluconeogenesis during L-alanine infusion in weight-losing lung
cancer patients as observed by phosphorus magnetic resonance spectroscopy and
turnover measurements.
AB - Profound alterations in host metabolism in lung cancer patients with weight loss
have been reported, including elevated phosphomonoesters (PMEs) as detected by
31P magnetic resonance spectroscopy (MRS). In healthy subjects, infusion of L
alanine induced significant increases in hepatic PMEs and phosphodiesters (PDEs)
due to rising concentrations of 3-phosphoglycerate and phosphoenolpyruvate,
respectively. The aim of the present study was to monitor these changes in the
tumor-free liver of lung cancer patients during L-alanine infusion by means of
simultaneous 31P MRS and turnover measurements. Twenty-one lung cancer patients
without liver metastases with (CaWL) or without weight loss (CaWS), and 12
healthy control subjects were studied during an i.v. L-alanine challenge of 1.4
2.8 mmol/kg followed by 2.8 mmol/kg/h for 90 min. Plasma L-alanine concentrations
increased during alanine infusion, from 0.35-0.37 mM at baseline to 5.37 +/- 0.14
mM in the CaWL patients, 6.67 +/- 0.51 mM in the CaWS patients, and 8.47 +/- 0.88
mM in the controls (difference from baseline and between groups during alanine
infusion, all P < 0.001). Glucose turnover and liver PME levels at baseline were
significantly elevated in the CaWL patients. Alanine infusion increased whole
body glucose turnover by 8 +/- 3% in the CaWS patients (P = 0.03), whereas no
significant change occurred in the CaWL and controls. PME levels increased by 50
+/- 16% in controls (area under the curve, P < 0.01) and by 87 +/- 31% in the
CaWS patients (P < 0.05) after 45-90 min. In contrast, no significant changes in
PME levels were observed in the CaWL patients. Plasma insulin concentrations
increased during L-alanine infusion in all groups to levels that were lower in
the CaWL patients than in the CaWS patients and controls (P < 0.05). In lung
cancer patients, but not in controls, changes in PME and PDE levels during
alanine infusion were inversely correlated with their respective baseline levels
(r = -0.82 and -0.86, respectively; P < 0.001). In addition, changes in PMEs
during alanine infusion in lung cancer patients were inversely correlated with
the degree of weight loss (r = -0.54; P < 0.05). This study demonstrates the
presence of major alterations in the pathway of hepatic gluconeogenesis in weight
losing lung cancer patients, as shown by elevated glucose flux before and during
L-alanine infusion, and by the increased PME and PDE levels, which reflect
accumulation of gluconeogenic intermediates in these patients. Weight-stable lung
cancer patients show accelerated increases in PME and PDE levels during L-alanine
infusion, suggesting enhanced induction of the gluconeogenic pathway. Our results
suggest altered gluconeogenic enzyme activities and elevated alanine uptake
within the livers of weight-losing/weight-stable lung cancer patients.
PMID- 10676646
TI - Imaging brain tumor proliferative activity with [124I]iododeoxyuridine.
AB - Iododeoxyuridine (IUdR) uptake and retention was imaged by positron emission
tomography (PET) at 0-48 min and 24 h after administration of 28.0-64.4 MBq (0.76
1.74 mCi) of [124I]IUdR in 20 patients with brain tumors, including meningiomas
and gliomas. The PET images were directly compared with gadolinium contrast
enhanced or T2-weighted magnetic resonance images. Estimates for IUdR-DNA
incorporation in tumor tissue (Ki) required pharmacokinetic modeling and fitting
of the 0-48 min dynamically acquired data to correct the 24-h image data for
residual, nonincorporated radioactivity that did not clear from the tissue during
the 24-h period after IUdR injection. Standard uptake values (SUVs) and
tumor:brain activity ratios (Tm:Br) were also calculated from the 24-h image
data. The Ki, SUV, and Tm/Br values were related to tumor type and grade, tumor
labeling index, and survival after the PET scan. The plasma half-life of
[124I]IUdR was short (2-3 min), and the arterial plasma input function was
similar between patients (48 +/- 12 SUV*min). Plasma clearance of the major
radiolabeled metabolite ([124I]iodide) varied somewhat between patients and was
markedly prolonged in one patient with renal insufficiency. It was apparent from
our analysis that a sizable fraction (15-93%) of residual nonincorporated
radioactivity (largely [124I]iodide) remained in the tumors after the 24-h
washout period, and this fraction varied between the different tumor groups.
Because the SUV and Tm:Br ratio values reflect both IUdR-DNA incorporated and
exchangeable nonincorporated radioactivity, any residual nonincorporated
radioactivity will amplify their values and distort their significance and
interpretation. This was particularly apparent in the meningioma and glioblastoma
multiforme groups of tumors. Mean tumor Ki values ranged between 0.5 +/- 0.9
(meningiomas) and 3.9 +/- 2.3 microl/min/g (peak value for glioblastoma
multiforme, GBM). Comparable SUV and Tm:Br values at 24 h ranged from 0.13 +/-
0.03 to 0.29 +/- 0.19 and from 2.0 +/- 0.6 to 6.1 +/- 1.5 for meningiomas and
peak GBMs, respectively. Thus, the range of values was much greater for Ki
(approximately 8-fold) compared with that for SUV (approximately 2.2-fold) and
Tm:Br (approximately 3-fold). The expected relationships between Ki, SUV, and
Tm:Br and other measures of tumor proliferation (tumor type and grade, labeling
index, and patient survival) were observed. However, greater image specificity
and significance of the SUV and Tm:Br values would be obtained by achieving
greater washout and clearance of the exchangeable fraction of residual
(background) radioactivity in the tumors, i.e., by increased hydration and
urinary clearance and possibly by imaging later than 24 h after [124I]IUdR
administration.
PMID- 10676647
TI - The urokinase system of plasminogen activation and prognosis in 2780 breast
cancer patients.
AB - The antigen levels of components of the urokinase-type plasminogen activator
(uPA) system of plasminogen activation are correlated with prognosis in several
types of cancers, including breast cancer. In the present study involving 2780
patients with primary invasive breast cancer, we have evaluated the prognostic
importance of the four major components of the uPA system [uPA, the receptor uPAR
(CD87), and the inhibitors PAI-1 and PAI-2]. The antigen levels were determined
by ELISA in cytosols prepared from primary breast tumors. The levels of the four
factors significantly correlated with each other; the Spearman rank correlation
coefficients (r(s)) ranged from 0.32 (between PAI-2 and PAI-1 or uPAR) to 0.59
(between uPA and PAI-1). The median duration of follow-up of patients still alive
was 88 months. In the multivariate analyses for relapse-free survival (RFS) and
overall survival (OS), we defined a basic model including age, menopausal status,
tumor size and grade, lymph node status, adjuvant therapy, and steroid hormone
receptor status. uPA, uPAR, PAI-1, and PAI-2 were considered as categorical
variables, each with two cut points that were established by isotonic regression
analysis. Compared with tumors with low levels, those with intermediate and high
levels showed a relative hazard rate (RHR) and 95% confidence interval (95% CI)
of 1.22 (1.02-1.45) and 1.69 (1.39-2.05) for uPA, and 1.32 (1.14-1.54) and 2.17
(1.74-2.70) for PAI-1, respectively, in multivariate analysis for RFS in all
patients. Compared with tumors with high PAI-2 levels, those with intermediate
and low levels showed a poor RFS with a RHR (95% CI) of 1.30 (1.14-1.48) and 1.76
(1.38-2.24), respectively. Similar results were obtained in the multivariate
analysis for OS in all patients. Furthermore, uPA and PAI-1 were independent
predictive factors of a poor RFS and OS in node-negative and node-positive
patients. PAI-2 also added to the multivariate models for RFS in node-negative
and node-positive patients, and in the analysis for OS in node-negative patients.
uPAR did not further contribute to any of the multivariate models. A prognostic
score was calculated based on the estimates from the final multivariate model for
RFS. Using this score, the difference between the highest and lowest 10% risk
groups was 66% in the analysis for RFS at 10 years and 61% in the analysis for
OS. Moreover, separate prognostic scores were calculated for node-negative and
node-positive patients. In the 10% highest risk groups, the proportion of disease
free patients was only 27 +/- 6% and 9 +/- 3% at 10 years for node-negative and
node-positive patients, respectively. These proportions were 86 +/- 4% and 61 +/-
6% for the corresponding 10% lowest risk groups of relapse. We conclude that
several components of the uPA system are potential predictors of RFS and OS in
patients with primary invasive breast cancer. Knowledge of these factors could be
helpful to assess the individual risk of patients, to select various types of
adjuvant treatment and to identify patients who may benefit from targeted
therapies that are currently being developed.
PMID- 10676648
TI - Substantially reduced risk of cancer of the aerodigestive tract in subjects with
variant--463A of the myeloperoxidase gene.
AB - Myeloperoxidase (MPO), an enzyme that is highly expressed in neutrophil
leukocytes, transforms precarcinogens such as benzo(a)pyrene and aromatic amines
to highly reactive intermediates. A G/A polymorphism located 463 bp upstream of
exon 1 in the promoter region strongly reduces MPO mRNA expression. In a matched
case-control study, 196 lung cancer, 245 laryngeal cancer, and 255 pharyngeal
cancer patients from the Berlin area were investigated for frequency of the G
463A polymorphism by PCR/RFLP, using AciI. They were matched by age and gender to
hospital patients without known malignancies. Moreover, 270 healthy volunteers
were genotyped, obtaining 61.1% of individuals with MPO genotype -463G/G, 34.8%
of individuals with genotype G/A, and 4.1% of individuals with genotype A/A. In
lung and laryngeal cancer patients, but not in pharyngeal cancer patients, mutant
genotypes were significantly less frequent. Crude odds ratios for carriers of one
or two A alleles, compared to wild-type G/G, were 0.58 [95% confidence interval
(CI), 0.38-0.88; P = 0.011] for lung cancer patients, 0.63 (95% CI, 0.43-0.92; P
= 0.017) for laryngeal cancer patients, and 0.82 (95% CI, 0.57-1.17; P = 0.27)
for pharyngeal cancer patients. The relative risks, adjusted for age, gender, and
extent of cigarette smoking were 0.47 (95% CI, 0.28-0.79; P = 0.004), 0.66 (95%
CI, 0.44-1.01; P = 0.054), and 0.75 (95% CI, 0.51-1.12; P = 0.16) for lung,
larynx, and pharyngeal cancer, respectively. Strikingly, relative risk for
carriers of -463A among adenocarcinoma of the lung was 0.24 (95% CI, 0.10-0.58; P
= 0.002). Two cases with larynx cancer, one case with lung cancer, and one
reference subject displayed novel G/A mutations at -297 nucleotide and -296
nucleotide, destroying a constitutive AciI cleavage site. Our data finally
suggest that the MPO -463A variant is a protective factor in the etiology of lung
and larynx cancer, but possibly not of pharyngeal cancer.
PMID- 10676649
TI - Manumycin enhances the cytotoxic effect of paclitaxel on anaplastic thyroid
carcinoma cells.
AB - Despite the current multimodal approach to treatment of anaplastic thyroid cancer
(ATC), the prognosis for patients with the disease is poor. New effective therapy
for ATC is desperately needed. Thus, we investigated the effects of manumycin (a
farnesyl:protein transferase inhibitor), alone and in combination with other
drugs frequently used to treat ATC, in six human ATC cell lines: ARO, C643, DRO,
Hth-74, KAT-4, and KAT-18. By means of a formazan dye-based spectrophotometric
assay of cell viability and light microscopy, manumycin was shown to decrease the
number of viable cells in all six of the cell lines though to a lesser degree in
DRO and C643 cells than in ARO, Hth-74, KAT-4, and KAT-18 cells. In combination,
manumycin enhanced the effect of paclitaxel in all six of the cell lines. The
mechanism of cell death was investigated by measuring caspase-3 activity,
immunoblotting with anti-poly-(ADP-ribose)polymerase (PARP) antibody and
electrophoresis of DNA. After an 18-h incubation, manumycin plus paclitaxel
caused enhanced activation of caspase-3 activity, cleavage of PARP into Mr 89,000
and 28,000 fragments, and internucleosomal fragmentation of DNA (all of which are
characteristic of apoptotic cell death). In contrast, neither manumycin alone,
paclitaxel alone, doxorubicin alone, nor doxorubicin plus manumycin produced
significant specific cleavage of PARP and internucleosomal DNA fragmentation
after 18 h of incubation. The in vivo effect and toxicity of combined manumycin
and paclitaxel treatments were evaluated in a nude mouse xenograft model using
ARO and KAT-4 cells. Drugs were injected i.p. on days 1 and 3 of a 7-day cycle
for three cycles. Both manumycin (7.5 mg/kg/dose) and paclitaxel (20 mg/kg/dose)
had significant inhibitory effects on tumor growth. Combined manumycin and
paclitaxel treatments seemed as effective as manumycin against ARO cells and more
effective than either manumycin or paclitaxel alone against KAT-4 cells. No
significant morbidity or mortality was caused by the treatments. In conclusion,
manumycin can inhibit the growth of ATC both in vitro and in vivo. Manumycin plus
paclitaxel has enhanced cytotoxic effects and increased apoptotic cell death in
ATC cells in vitro compared with either drug by itself. The combination of
manumycin and paclitaxel is also effective in vivo with no significant toxicity
observed. The lack of synergy observed in this in vivo experiment may be due to a
ceiling effect, and further experimentation is warranted to ascertain the optimal
way to combine these two agents for maximal therapeutic effects.
PMID- 10676650
TI - Expression of endogenously activated secreted or cell surface carboxypeptidase A
sensitizes tumor cells to methotrexate-alpha-peptide prodrugs.
AB - Methotrexate (MTX) is one of the most commonly used agents in the treatment of
solid malignancies; however, the toxicities of MTX to bone marrow and
gastrointestinal tract complicate this therapy. We, therefore, propose a gene
dependent enzyme prodrug therapy to limit these toxicities by localizing the
production of MTX to the site of the tumor. The combination of MTX-alpha-peptide
prodrugs, which cannot be internalized by the cellular reduced folate carrier,
with carboxypeptidase A (CPA), which can remove the blocking peptide, has been
demonstrated previously in vitro using antibody-dependent enzyme prodrug therapy.
CPA is normally synthesized as a zymogen that is inactive without proteolytic
removal of its propeptide by trypsin. Therefore, to adapt this system to gene
dependent enzyme prodrug therapy, a mutant form of CPA was engineered, CPA(ST3),
that does not require trypsin-dependent zymogen cleavage but is instead activated
by ubiquitously expressed intracellular propeptidases. Purification, peptide
sequencing, and kinetic analysis indicated that mature CPA(ST3) is structurally
and functionally similar to the trypsin-activated, wild-type enzyme. In addition,
CPA(ST3)-expressing tumors cells were sensitized to MTX prodrugs in a dose- and
time-dependent manner. To limit diffusion of CPA, a cell surface localized form
was generated by constructing a fusion protein between CPA(ST3) and the
phosphatidylinositol linkage domain from decay accelerating factor. SDS-PAGE and
flow cytometric analysis of infected tumor cells indicated that CPA(DAF) was cell
surface localized. Finally, after retroviral transduction, this enzyme/prodrug
strategy exhibited a potent bystander effect, even when <10% of the cells were
transduced, because extracellular production of MTX sensitized both transduced
and nontransduced cells.
PMID- 10676651
TI - Tumor-targeting chemotherapy by a xanthine oxidase-polymer conjugate that
generates oxygen-free radicals in tumor tissue.
AB - Xanthine oxidase (XO) mediates anticancer activity because of its ability to
generate cytotoxic reactive oxygen species (ROS), including superoxide anion
radical and hydrogen peroxide. However, the high binding affinity of XO to blood
vessels would cause systemic vascular damage and hence limits the use of native
XO in clinical settings. We demonstrate here that chemical conjugation of XO with
poly(ethylene glycol) (PEG; the conjugates hereafter referred to as PEG-XO)
significantly enhanced the tumor-targeting efficacy and the antitumor activity of
XO. By using a succinimide-activated PEG derivative, PEG was conjugated to
epsilon-amino groups of lysine residues of XO, which play a crucial role in
binding of XO to blood vessels. PEG-XO administered i.v. showed a 2.8-fold higher
accumulation in solid tumor compared with that of native XO 24 h after injection,
whereas a slight or negligible increase in accumulation of PEG-XO was observed in
normal organs. The highest PEG-XO enzyme activity was detected in tumor compared
with normal organs or tissues except blood; enzyme activity in tumor was 5.0,
3.9, and 9.4 times higher than that in liver, kidney, and spleen, respectively.
Intratumor activity remained high for >48 h. Administration of hypoxanthine, a
substrate of XO, at 33 mg/kg body weight i.p. 12 h after the administration of
PEG-XO (0.6 unit/mouse, i.v.) resulted in significant suppression of tumor growth
(P < 0.001), with no tumor growth even after 52 days. However, either PEG-XO or
hypoxanthine alone, or native XO with hypoxanthine, showed no effect on the
inhibition of tumor growth under present experimental conditions. These findings
suggest that PEG-XO, which accumulates preferentially in tumor tissue, warrants
further investigation as a novel anticancer agent.
PMID- 10676652
TI - Functional interactions between bile acids, all-trans retinoic acid, and 1,25
dihydroxy-vitamin D3 on monocytic differentiation and myeloblastin gene down
regulation in HL60 and THP-1 human leukemia cells.
AB - Bile acids were shown previously to inhibit proliferation and to induce monocytic
differentiation in HL60 human acute promyelocytic leukemia cells (A. Zimber et
al., Int. J. Cancer, 59: 71-77, 1994). In this report, we hypothesized that bile
acids may exert a positive cooperativity with two known inducers of leukemic cell
differentiation, all-trans retinoic acid and 1,25(OH)2-vitamin D3. Our results
provide evidence that bile acids induced the monocytic differentiation of HL60
and THP-1 human leukemia cells exposed to ineffective concentrations of these
inducers. The protein kinase C (PKC) inhibitors H-7 (10 and 20 microM) and
staurosporine (5 and 20 nM) modulated the effects of bile acids on HL60 cell
differentiation. Most interestingly, bile acids are shown herein to down-regulate
the expression of the serine protease myeloblastin gene involved in the
differentiation of myeloid hematopoietic cells. In agreement with the recent
identification of nuclear receptors for bile acids, our data suggest that
functional interactions between nuclear bile acid signaling pathways, PKC, and
nuclear receptors for retinoic acid and vitamin D3 are involved in the down
regulation of the myeloblastin gene and the induction of cell differentiation in
human leukemic cells.
PMID- 10676653
TI - p21WAF1/CIP1 antisense therapy radiosensitizes human colon cancer by converting
growth arrest to apoptosis.
AB - Substantial evidence suggests that loss of cellular p21WAF1/CIP1 results in
increased apoptotic killing by ionizing radiation. We hypothesized that a p21
antisense (AS) oligodeoxynucleotide (ODN) could be used to sensitize cancer cells
to radiotherapy. In vitro treatment of colon cancer cells (HCT116/p21+/+) with
p21 AS ODN (200 nM) led to inhibition of radiation-induced p21 expression (>95%
inhibition, 0-30 Gy), resulting in a loss of G1 arrest and an enhancement of
apoptosis to comparable levels and with similar kinetics to HCT116/p21-/- cells
(approximately 60% apoptotic cells at 96 h after 10 Gy). In vivo, p21 AS ODN in
combination with radiation (i.p. ODN for 6 days at 20 mg/kg/day and 15 Gy)
increased apoptosis in s.c. p21+/+ tumors in nude mice to levels similar to those
of p21-/- tumors (2-fold at 24 h postirradiation) and improved radiocurability of
p21+/+ tumors to levels comparable to those of p21-/- tumors (p21+/+, two of
eight cures versus p21-/-, two of nine cures). Our findings suggest that p21 AS
treatment may be a rational approach to improve conventional radiotherapy
outcomes.
PMID- 10676654
TI - Interleukin-7/B7.1-encoding adenoviruses induce rejection of transplanted but not
nontransplanted tumors.
AB - Most cancer vaccine trials are based on efficacy studies against transplanted
mouse tumors that poorly reflect the clinical situation. We constructed
adenoviruses expressing interleukin-7 and B7.1 and tested their therapeutic
efficacy after transfer into established transplanted and nontransplanted 3
methylcholanthrene-induced tumors. The adenoviruses efficiently induced rejection
of transplanted tumors, leaving behind systemic immunity. Against nontransplanted
tumors of similar size, there were almost no therapeutic effects. This result was
not due to the site of tumor development, tumor type, general immune suppression,
or differences in transduction efficacy. Adenoviral expression of beta
galactosidase as a surrogate antigen in nontransplanted tumors induced cytotoxic
T cells that were unable to quantitatively reach the tumor site. Based on
rigorous mouse models and an effective in situ immunization procedure, it is
suggested that cancer vaccines can be effective, if at all, against "minimal
residual disease"; additional experimental procedures must be found against
established nontransplanted tumors.
PMID- 10676655
TI - Targeting of human p53-overexpressing tumor cells by an HLA A*0201-restricted
murine T-cell receptor expressed in Jurkat T cells.
AB - A potent anti-human (hu) p53 CD8+ CTL response develops in HLA A*0201 transgenic
(Tg) mice after immunization with peptides corresponding to HLA A*0201 motifs
from hu p53. Mice immunized with the hu P53(149-157) peptide develop a CTL
response that is of moderately high affinity and is capable of recognizing hu
tumor cells expressing mutated p53. In this report, the mRNAs encoding the
predominantly expressed T-cell receptor (TCR) sequences were molecularly cloned
from a murine (mu) CTL clone derived from immunized Tg mice, which recognized
endogenously processed hu p53 restricted by HLA A*0201. The separate A and B
chain TCR cDNAs were transfected in the corresponding TCR A- and B- Jurkat-CD3-
mutant T-cell lines, and each rescued CD3 surface expression. Both TCR chains
were simultaneously introduced into Jurkat-CD3+ cells, and the transfected Jurkat
cells recognized hu T2 cells sensitized with the p53(149-157) CTL epitope but not
T2 cells sensitized with a nonspecific CTL epitope. Breast, pancreatic, and
sarcoma tumor cell lines, which overexpress endogenous mutated p53, were
recognized in the presence of anti-CD28 costimulation, only if they also
expressed HLA A*0201. Normal hu fibroblasts established from skin cultures were
not recognized. These results represent the first time that a p53-specific TCR
capable of recognizing hu cancer cells was heterologously expressed in a naive
recipient cell, converting that cell to one recognizing hu tumor cells with
mutated p53. This TCR represents a candidate molecule for a genetic strategy in
combating hu cancer by an adoptive immunotherapy approach, which uses the strong
xenorecognition of hu p53 in mice.
PMID- 10676656
TI - Frequent methylation of estrogen receptor in prostate cancer: correlation with
tumor progression.
AB - Prior studies have shown that the estrogen receptor (ER) gene is down-regulated
in prostate cancer, but the mechanism of its inactivation is not known. We
hypothesize that inactivation of the ER gene in prostate cancer is through
promoter methylation. To test this hypothesis, we investigated the methylation
status of the ER gene in prostate cancer cell lines, prostate cancer, and benign
prostatic hyperplasia (BPH) tissues samples using the bisulfite genomic
sequencing method. Our results show that the ER gene promoter was methylated in
100% (six of six) of the prostate cancer cell lines tested and all were
accompanied by loss of ER mRNA expression. Treatment of these cell lines with
demethylating agent 5-aza-2'-deoxycytidine restored ER mRNA expression in all of
the ER-negative cell lines. In addition, elevated expression of DNA
methyltransferase mRNA was found in all of the prostate cancer cell lines. Of the
prostate tissue samples analyzed, 60% (6 of 10) in the BPH samples, 80% (8 of 10)
in the low-grade cancer samples (grades I and II), and 95% (20 of 21) in the high
grade cancer samples (grades III-V) exhibited promoter methylation of the ER
gene. The overall methylation levels in the cancer samples were higher than that
in the BPH samples. The differences between the high-grade cancer samples and BPH
samples were significant at all CpG sites. Only at three CpG sites were the
differences significant between the low-grade cancer samples and BPH samples.
This study presents the first evidence that ER gene is transcriptionally
inactivated by DNA methylation in prostate cancer. Our data suggest that ER may
be involved in the pathogenesis of prostate cancer, as well as BPH.
PMID- 10676657
TI - Detection of plasma tumor DNA in head and neck squamous cell carcinoma by
microsatellite typing and p53 mutation analysis.
AB - Recent arguments have suggested that tumor DNA in cancer patients could be found
in plasma, but different points remain unclear. Using a series of 117 head and
neck squamous cell carcinoma tumors, our goals for this study were: (a) to
quantify the amount of plasma DNA; (b) to evaluate the presence of plasma tumor
DNA; and (c) to analyze the clinical relevance of tests based on plasma DNA
analyses. Low levels of plasma DNA were found in most samples, but all were
successfully amplified. Two different methods were used to detect tumor-specific
genetic alterations: (a) microsatellite instability at UT5085 with an established
sensitivity of 1:500; and (b) p53 mutation screening. Of the 117 tumors typed at
UT5085, 65 demonstrated bandshifts (55%). Plasma and tumor DNA a showed similar
alteration in only one case among these samples, and the prevalence of tumor DNA
in plasma was estimated to be <2% using microsatellite analysis. Tumor DNA was
detected in plasma at a higher prevalence (2 of 11 cases) when using p53 mutant
allele-specific amplification. These results showed that in plasma, tumor DNA is
largely diluted by normal DNA. By comparison with previously published studies,
the prevalence of microsatellite alterations in plasma in this series of head and
neck squamous cell carcinomas is very low, despite the fact that a large series
of tumors was analyzed. To explain this discrepancy, we analyzed the possibility
of PCR artifacts as suspected by the presence of loss of heterozygosity in two
plasma DNA samples without a similar tumor DNA alteration. When DNA
concentrations were under the threshold of detection (<100 ng/ml), we
demonstrated that PCR artifacts could occur at random, and, if misinterpreted,
these false genetic alterations could artificially enhance the frequency of
plasma DNA alterations. This may have been suspected in previously published
series, but it has never been discussed before. Microsatellite analysis on plasma
DNA is difficult to interpret and can frequently be misleading. Plasma DNA should
be analyzed with very sensitive and specific methods such as mutant allele
specific amplification, which excludes artifacts but requires specific
optimization that is probably not compatible with routine and clinical use.
PMID- 10676658
TI - Integrins alpha(v)beta3 and alpha(v)beta5 are expressed by endothelium of high
risk neuroblastoma and their inhibition is associated with increased endogenous
ceramide.
AB - Inhibition of the RGD-binding integrins, alpha(v)beta3 and alpha(v)beta5,
prevents endothelial cell anchorage and induces endothelial apoptosis, which
results in disruption of tumor angiogenesis and inhibition of tumor growth in
animal models. In this study, we demonstrate by immunohistochemical analysis that
integrin alpha(v)beta3 was expressed by 61% (mean) of microvessels in high-risk
neuroblastomas (stage IV and MYCN-amplified stage III; n = 28) but only by 18%
(mean) of microvessels in low-risk tumors (stages I and II and non-MYCN-amplified
stage III; n = 12). Integrin alpha(v)beta5 was found on 60% (mean) of
microvessels in 21 Stage IV tumors. These data suggest that neuroblastomas may be
targeted for antiangiogenic treatment directed against endothelial integrins
alpha(v)beta3 and alpha(v)beta5. In cell culture, inhibition of integrin
dependent endothelial cell anchorage to vitronectin by RGDfV, an RGD function
blocking cyclic peptide, induced apoptosis in bovine brain endothelial cells
compared with the control peptide, RADfV (37.5% versus 8.7%, respectively), as
detected by chromatin condensation and nuclear fragmentation. Treatment with
RGDfV but not with RADfV, which prevented attachment of endothelial cells to
vitronectin or fibronectin, was associated with up to a 50% increase in
endogenous ceramide, a lipid second messenger that can mediate cell death.
Furthermore, exogenous C2-ceramide was cytotoxic to bovine brain endothelial
cells and induced activation of C-jun N-terminal kinase (JNK), a MAP kinase that
can be activated in stress-induced apoptosis pathways. This suggests that
ceramide may function in detachment-induced endothelial cell apoptosis,
originating from inhibition of vitronectin binding to integrins such as
alpha(v)beta3 and alpha(v)beta5. This is the first report to demonstrate
expression of integrins alpha(v)beta3 and alpha(v)beta5 by microvascular
endothelium of a childhood tumor and association of their expression with
neuroblastoma aggressiveness. Furthermore, our data provide the first suggestion
that inhibition of endothelial cell anchorage, resulting from specific blockade
of RGD-binding integrins, increases endogenous ceramide, which may contribute to
endothelial cell death.
PMID- 10676659
TI - Aminopeptidase N is a receptor for tumor-homing peptides and a target for
inhibiting angiogenesis.
AB - Phage that display a surface peptide with the NGR sequence motif home selectively
to tumor vasculature in vivo. A drug coupled to an NGR peptide has more potent
antitumor effects than the free drug [W. Arap et al., Science (Washington DC),
279: 377-380, 1998]. We show here that the receptor for the NGR peptides in tumor
vasculature is aminopeptidase N (APN; also called CD13). NGR phage specifically
bound to immunocaptured APN and to cells engineered to express APN on their
surface. Antibodies against APN inhibited in vivo tumor homing by the NGR phage.
Immunohistochemical staining showed that APN expression is up-regulated in
endothelial cells within mouse and human tumors. In another tissue that undergoes
angiogenesis, corpus luteum, blood vessels also expressed APN, but APN was not
detected in blood vessels of various other normal tissues stained under the same
conditions. APN antagonists specifically inhibited angiogenesis in
chorioallantoic membranes and in the retina and suppressed tumor growth. Thus,
APN is involved in angiogenesis and can serve as a target for delivering drugs
into tumors and for inhibiting angiogenesis.
PMID- 10676660
TI - Selective expression and constitutive phosphorylation of SHC proteins [corrected]
in the CD34+ fraction of chronic myelogenous leukemias.
AB - The BCR/ABL fusion protein is a constitutively active tyrosine kinase that is
responsible for the pathogenesis of chronic myelogenous leukemia (CML).
Clinically, CML is characterized by a chronic phase (CP) that eventually
terminates into a blast crisis (BC). BC transformation is associated with
accumulation of CD34+ blasts. We investigated the expression and phosphorylation
of Src-homology-2 and collagen-homology domains (SHC) [corrected] proteins in
subpopulations of CML primary cells. Shc polypeptides are tyrosine kinase
substrates that are constitutively tyrosine-phosphorylated in continuous cell
lines of CML origin. High levels of Shc expression were found in the CD34+ cells
from CML-BC, CML-CP and normal bone marrow. In contrast, CD34- fractions from CML
CP and normal bone marrow expressed low levels of p46Shc. Shc proteins were
constitutively phosphorylated in the CD34+ fractions from CML cells (both CP and
BC), but not in normal CD34+ cells. These data bear implications for the role of
Shc in normal hemopoiesis and CML leukemogenesis: (a) dramatic changes of Shc
expression during terminal differentiation of hemopoietic cells adds a further
level of regulation to the signal transduction function of Shc; and (b)
constitutive Shc tyrosine-phosphorylation in the rare CD34+ cells of CML-CP might
contribute to the selection of this subpopulation during the blast crisis
transformation of CMLs.
PMID- 10676661
TI - Basic fibroblast growth factor confers a less malignant phenotype in MDA-MB-231
human breast cancer cells.
AB - Basic fibroblast growth factor (FGF-2) expression is associated with a more
differentiated phenotype, earlier stage of disease, and a better prognosis in
breast cancer patients. To determine whether expression of FGF-2 can cause a less
malignant phenotype, we engineered MDA-MB-231 cells, a highly dedifferentiated,
invasive breast cancer cell line, to express different isoforms of FGF-2. Cells
expressed either cytoplasmic, nuclear, or a combination of both FGF-2 isoforms.
Western blots of 2 M NaCl washes and of conditioned medium demonstrated that
these cells did not export FGF-2. Cells expressing FGF-2 had levels of fibroblast
growth factor receptors equivalent with those of control cells. Transformation
was assayed by anchorage-independent colony formation and tumor formation in
athymic mice. All of the constructs expressing various FGF-2 isoforms had a 60
70% reduction in colony formation in soft agar, but only cells expressing the Mr
18,000 FGF-2 isoform formed fewer and smaller tumors in mice. To determine
potential mechanisms responsible for a less malignant phenotype, experiments
measuring invasion in Matrigel, the secretion of matrix metalloprotease activity
and migration in a modified Boyden chamber and in a patch wound motility assay
were carried out. Cells expressing the Mr 18,000 cytoplasmic FGF-2 moiety had a
45% decrease in invasion in Matrigel compared to vector-transfected controls.
Cells expressing Mr 18,000 FGF-2 had an increase in Mr 97,000 and Mr 48,000
collagenase, demonstrating that the decreased invasive potential was not due to a
down-regulation of gelatinolytic or caseinolytic matrix metalloproteinases.
However, motility was decreased in both assays, primarily in cells expressing Mr
18,000 FGF-2, whereas exogenous recombinant human FGF-2 had no effect. These
studies demonstrate for the first time that FGF-2 expression can cause a less
malignant phenotype in breast cancer cells, possibly as a result of decreased
motility and invasion.
PMID- 10676662
TI - Androgen deprivation of the PC-310 [correction of prohormone convertase-310]
human prostate cancer model system induces neuroendocrine differentiation.
AB - Neuroendocrine (NE) cells are androgen-independent cells and secrete growth
modulating neuropeptides via a regulated secretory pathway (RSP). We studied NE
differentiation after androgen withdrawal in the androgen-dependent prostate
cancer xenograft PC-310. Expression patterns of chromogranin A, secretogranin
III, and prohormone convertase-1 were analyzed at both protein and mRNA level to
mark the kinetics of NE differentiation both in vivo and in vitro. PC-310 tumor
bearing nude mice were killed at 0, 2, 5, 7, 14, and 21 days postcastration. PC
310C cultures initiated from collagenase-treated tumor tissue could be maintained
up to four passages, and androgen-deprivation experiments were performed
similarly. PC-310 tumor volumes decreased by 50% in 10 days postcastration.
Proliferative activity and prostate-specific antigen (PSA) serum levels decreased
to zero postcastration, whereas PSA levels in PC-310C culture media first
decreased and subsequently increased after 5 days. In vivo, androgen receptor
(AR) expression decreased initially but returned to control level from 5 days
postcastration on. CgA, secretogranin III, and secretogranin V expression
increased in vivo from 5 days postcastration on. Subsequently, prohormone
convertase-1 and peptidyl alpha-amidating monooxygenase as well as the vascular
endothelial growth factor were expressed from 7 days postcastration on, and,
finally, growth factors such as gastrin-releasing peptide and serotonin were
expressed in a small part of the NE cells 21 days postcastration. The PC-310
tumors did not show colocalization of the AR on the NE cells in the tumor
residues after 21 days. As in the PC-310 xenograft, NE differentiation was
induced and AR expression relapsed after prolonged androgen suppression in PC
310C. For PC-310C cells, this relapse was associated with the secretion of PSA.
PC-310C is the first culture of human prostatic cancer cells having the NE
phenotype. The PC-310 model system is a potential androgen-dependent model for
studying the role of NE cells in the progression of clinical prostate cancer.
Androgen deprivation of NE-differentiated prostate cancer may induce the
formation of both NE- and AR-positive dormant tumor residues, capable of actively
producing NE growth factors via a RSP, possibly leading to hormone refractory
disease.
PMID- 10676663
TI - Drg-1 as a differentiation-related, putative metastatic suppressor gene in human
colon cancer.
AB - A gene related to cell differentiation was identified by differential display as
a candidate suppressor of metastases in colon cancer. This gene, with a full
length cDNA of 3 kb, is expressed in normal colon and primary colon cancer
tissues and cell lines but not in their metastatic counterparts. A GenBank search
found that it is identical to a recently cloned gene, differentiation-related
gene-1 (Drg-1), isolated from differentiated HT-29 colon cancer cells. Stable
transfection of the SW620 metastatic colon cancer cell line with Drg-1 cDNA
induced morphological changes consistent with differentiation and up-regulated
the expression of several colonic epithelial cell differentiation markers
(alkaline phosphatase, carcinoembryonic antigen, and E-cadherin). Moreover, the
expression of Drg-1 is controlled by several known cell differentiation reagents,
such as ligands of peroxisome proliferator-activated receptor gamma (troglitazone
and BRL46593) and of retinoid X receptor (LG268), and histone deacetylase
inhibitors (trichostatin A, suberoylanilide hydroxamic acid, and tributyrin). A
synergistic induction of Drg-1 expression was seen with the combination of
tributyrin and a low dose of 5'-aza-2'-dexoycytidine (100 nM), an inhibitor of
DNA methylation. Functional studies revealed that overexpression of Drg-1 in
metastatic colon cancer cells reduced in vitro invasion through Matrigel and
suppressed in vivo liver metastases in nude mice. We propose that Drg-1
suppresses colon cancer metastasis by inducing colon cancer cell differentiation
and partially reversing the metastatic phenotype.
PMID- 10676664
TI - A precursor form of prostate-specific antigen is more highly elevated in prostate
cancer compared with benign transition zone prostate tissue.
AB - Prostate-specific antigen (PSA) is a widely used serum marker for prostate cancer
(PCa), but in the critical diagnostic range of 4-10 ng/ml it has limited
specificity for distinguishing early PCa from benign prostatic hyperplasia (BPH).
PSA in serum is comprised of a variety of both "free" and "complexed" forms that
have been used to improve the specificity of PSA for prostate cancer detection.
We previously reported that pro PSA (pPSA), the zymogen or precursor form of PSA,
is a component of free PSA in the serum of PCa patients. In the current study, we
examined prostate tissues to understand the origin and specificity of pPSA. PSA
was immuno-affinity purified from matched sets of prostate tissues including
peripheral zone cancer (PZ-C); peripheral zone noncancer; and benign tissue from
the transition zone (TZ), the primary site of BPH within the prostate. We found
that pPSA is differentially elevated in PZ-C, but is largely undetectable in TZ.
N-terminal sequencing revealed that the pPSA was comprised primarily of [-2]pPSA
and minor levels of [-4]pPSA, containing pro leader peptides of 2 and 4 amino
acids, respectively. The median value of pPSA was 3% in PZ-C and 0%
(undetectable) in TZ (P < 0.0026). No pPSA was detected in 13 of 18 transition
zone specimens (72%), but only 2 of the 18 matched cancer specimens (11%)
contained no measurable pPSA. These results demonstrate that pPSA is more highly
correlated with prostate cancer than with BPH. The pPSA in serum may represent a
more cancer-specific form of PSA that could help distinguish prostate cancer from
BPH.
PMID- 10676665
TI - Down-regulation of the insulin-like growth factor I receptor by antisense RNA can
reverse the transformed phenotype of human cervical cancer cell lines.
AB - The insulin-like growth factor I receptor (IGF-IR) plays an essential role in the
establishment and maintenance of transformed phenotype, and interference with the
IGF-IR pathway by antisense or dominant-negative mutants causes reversal of the
transformed phenotype in many rodent and human tumor cell lines. We stably
transfected an IGF-IR antisense mRNA expression plasmid into human papillomavirus
(HPV)-negative C33a cell line, HPV-16-positive SiHa cell line, and HPV-18
positive HeLa S3 cell line to determine whether the IGF-IR could be a target for
cervical cancer cells, especially in the presence of HPV. Approximately 30-80%
down-regulation of IGF-IR expression was observed by Western blot in antisense
transfected clones. There was a little inhibition in monolayer growth in all cell
lines. In C33a cells, wild-type and sense clones formed 92-146 colonies in soft
agar after 3 weeks; antisense clones formed <12 colonies. In SiHa cells, wild
type and sense clones formed approximately 60 colonies after 5 weeks; antisense
clones formed 0-3 colonies. In HeLa S3 cells, wild-type and sense clones formed
218-291 colonies in soft agar after 2 weeks; antisense clones formed 14-160
colonies. There was a good correlation between IGF-IR down-regulation level and
inhibition of transformation in soft agar. Tumorigenesis in nude mice was
strongly inhibited in HeLa S3 and SiHa clones transfected with the antisense.
These results indicate that down-regulation of IGF-IR by antisense RNA can
reverse the transformed phenotype of human cervical cancer cells, even when
harboring malignant type HPVs.
PMID- 10676666
TI - Correspondence re: S. Shintani et al., Intragenic mutation analysis of the human
epidermal growth factor receptor (EGFR) gene in malignant human oral
keratinocytes. Cancer Res., 59: 4142-4147, 1999.
PMID- 10676667
TI - Eleventh annual Pezcoller Symposium: molecular horizons in cancer therapeutics.
PMID- 10676668
TI - Dietary supplementation with marine omega-3 fatty acids improve systemic large
artery endothelial function in subjects with hypercholesterolemia.
AB - OBJECTIVE: This work was undertaken to determine whether dietary supplementation
with marine omega-3 fatty acids improve systemic large artery endothelial
function in subjects with hypercholesterolemia. BACKGROUND: Marine omega-3 fatty
acids improve vascular function, but the underlying mechanism(s) are unclear. We
studied the effects of marine omega-3 fatty acids on large artery endothelial
function in subjects with hypercholesterolemia. METHODS: Hypercholesterolemic
subjects with no other known cause for endothelial dysfunction were recruited to
a prospective, placebo-controlled, randomized, double-blind, parallel-group
study. Treatment with omega-3 fatty acids at a dose of 4 g/day (n = 15/group) was
compared with placebo, at the beginning (day 0) and end (day 120) of a four-month
treatment period. Endothelial function was assessed pre- and posttreatment by
noninvasive ultrasonic vessel wall tracking of brachial artery flow-mediated
dilation (FMD). RESULTS: Treatment with marine omega-3 fatty acids resulted in a
significant improvement in FMD (0.05 +/- 0.12 to 0.12 +/- 0.07 mm, p < 0.05) and
a significant reduction in triglycerides (2.07 +/- 1.13 to 1.73 +/- 0.95
mmol/liter, p < 0.05), whereas treatment with placebo resulted in no change in
FMD (0.03 +/- 0.10 to 0.04 +/- 0.10 mm) or triglycerides (2.29 +/- 2.09 to 2.05
+/- 1.36 mmol/liter) (both p < 0.05 treated compared with control). Responses to
sublingual glyceryl trinitrate were unchanged. CONCLUSIONS: Marine omega-3 fatty
acids improve large artery endothelium-dependent dilation in subjects with
hypercholesterolemia without affecting endothelium-independent dilation.
PMID- 10676669
TI - Effects of oral L-arginine on endothelium-dependent vasodilation and markers of
inflammation in healthy postmenopausal women.
AB - OBJECTIVES: We examined whether oral administration of L-arginine, the substrate
for nitric oxide (NO) synthesis, increases NO bioactivity in healthy
postmenopausal women. BACKGROUND: Nitric oxide may protect arteries against
atherosclerosis, as suggested by experimental studies in animals. Estrogen
therapy, which has been shown to increase NO bioactivity in the vasculature of
healthy postmenopausal women, is not acceptable for long-term use by many women.
METHODS: In a randomized, double-blind, crossover study, 10 postmenopausal women
without additional risk factors for atherosclerosis received L-arginine 9 g or
placebo daily for one month, with treatment periods separated by one month.
Nitric oxide levels in serum (as an index of endothelial NO release), brachial
artery endothelium-dependent dilator responses to hyperemia by ultrasonography
(as an index of vascular NO bioactivity) and markers of inflammation in blood
that are inhibited by NO in cell culture experiments were measured at the end of
each treatment period. RESULTS: L-arginine levels in plasma were increased in all
women during L-arginine treatment compared with placebo (136.8 +/- 63.1 vs. 75.2
+/- 16.2 micromol/liter, p = 0.009). However, there was no change in serum
nitrogen oxide levels (42.1 +/- 24.5 vs. 39.1 +/- 16.6 micromol/liter, p = 0.61),
nor was there an effect of L-arginine on flow-mediated dilation during hyperemia
(3.8 +/- 3.0% vs. 4.9 +/- 4.8%, p = 0.53) compared with placebo. Our study had
sufficient power (beta = 0.80) to detect a true absolute treatment difference in
flow-mediated brachial artery dilation of 1.7% or larger as statistically
significant at alpha = 0.05. There was no effect of L-arginine on serum levels of
soluble cell adhesion molecules compared with placebo: E-selectin (50.6 +/- 14.8
vs. 52.1 +/- 17.0 ng/ml, p = 0.45), intercellular adhesion molecule-1 (230 +/- 51
vs. 230 +/- 52 ng/ml, p = 0.97) and vascular cell adhesion molecule-1 (456 +/- 62
vs. 469 +/- 91 ng/ml, p = 0.53). CONCLUSIONS: Oral administration of L-arginine
may not augment endothelial NO synthesis and release in postmenopausal women and
is thus unlikely to be of general benefit to healthy postmenopausal women in
protection from the development of atherosclerosis.
PMID- 10676670
TI - Effects of vitamin E on chronic and acute endothelial dysfunction in smokers.
AB - OBJECTIVES: The aims of this study were to determine whether chronic or acute
impairment of flow mediated vasodilation (FMD) in the brachial artery of smokers
can be restored or preserved by the antioxidant vitamin E. BACKGROUND: Transient
impairment of endothelial function after heavy cigarette smoking and chronic
endothelial dysfunction in smokers result at least in part from increased
oxidative stress. METHODS: We studied 22 healthy male smokers (mean +/- SD, 23 +/
9 cigarettes per day) randomly assigned to receive either 600 IU vitamin E per
day (n = 11, age 28 +/- 6 years) or placebo (n = 11, age 27 +/- 6 years) for four
weeks and 11 age-matched healthy male nonsmokers. Flow mediated vasodilation and
endothelium-independent, nitroglycerin-induced dilation were assessed in the
brachial artery using high resolution ultrasound (7.5 MHz) at baseline and after
therapy. Subjects stopped smoking 2 h before the ultrasound examinations. At the
end of the treatment period, a third scan was obtained 20 min after smoking a
cigarette (0.6 mg nicotine, 7 mg tar) to estimate transient impairment of FMD.
RESULTS: Flow mediated vasodilation at baseline was abnormal in the vitamin E
(5.3 +/- 3.8, p < 0.01) and in the placebo group (6.4 +/- 3.5, p < 0.05) compared
with nonsmoking controls (11.6 +/- 4.7). Using a two-way repeated measures
analysis of variance (ANOVA) to examine the effects of vitamin E on FMD, we found
no effect for the grouping factor (p = 0.5834) in the ANOVA over time but a
highly significant difference with respect to time (p = 0.0065). The interaction
of the time factor and the grouping factor also proved to be significant (p =
0.0318). Flow mediated vasodilation values remained similar after treatment for
four weeks in both groups but declined faster after smoking a cigarette in
subjects taking placebo compared with those receiving vitamin E (p values from
successive differences for the time/group factor: 0.0001/0.0017). The transient
attenuation of FMD (calculated as the percent change in FMD) was related to the
improvement of the antioxidant status, estimated as percent changes in
thiobarbituric acid-reactive substances (r = -0.67, p = 0.0024). Nitroglycerin
induced dilation did not differ between study groups at baseline or after
therapy. CONCLUSIONS: These results demonstrate that oral supplementation of
vitamin E can attenuate transient impairment of endothelial function after heavy
smoking due to an improvement of the oxidative status but cannot restore chronic
endothelial dysfunction within four weeks in healthy male smokers.
PMID- 10676671
TI - A comparison of angiotensin-converting enzyme inhibitors, calcium antagonists,
beta-blockers and diuretic agents on reactive hyperemia in patients with
essential hypertension: a multicenter study.
AB - OBJECTIVES: The purpose of this study was to compare the effect of different
antihypertensive agents, calcium antagonists, angiotensin-converting enzyme (ACE)
inhibitors, beta-blockers and diuretic agents on endothelial function.
BACKGROUND: Endothelial dysfunction is a component of essential hypertension, and
various antihypertensive drugs may be able to restore normal function. METHODS:
Forearm blood flow (FBF) was measured in 296 patients with essential
hypertension, including 46 untreated subjects using strain-gauge plethysmography
during reactive hyperemia and after sublingual administration of nitroglycerin
(NTG). Forty-seven normotensive subjects were similarly evaluated as control
subjects. RESULTS: The FBF during reactive hyperemia in the 296 hypertensive
patients was significantly less than that in age-matched normotensive subjects.
The increase in FBF after administration of sublingual NTG was similar in both
groups. Systolic and diastolic blood pressures and forearm vascular resistance
were greater in the untreated group than in the four treated groups and did not
differ with respect to the antihypertensive agent used. The maximal FBF response
from reactive hyperemia was significantly greater in the ACE inhibitor-treated
group than in the group treated with calcium antagonists, beta-blockers, diuretic
agents, or nothing (40.5 +/- 5.2 vs. 32.9 +/- 5.8, 34.0 +/- 5.6, 32.1 +/- 5.9,
and 31.9 +/- 5.8 ml/min per 100 ml tissue, p < 0.05, respectively). Reactive
hyperemia was similar in the calcium antagonist, beta-blocker, diuretic and
untreated groups, and changes in FBF after sublingual NTG administration were
similar in all groups. The infusion of NG-monomethyl-L-arginine, a nitric oxide
(NO) synthase inhibitor, abolished the enhancement of reactive hyperemia in
hypertensive patients treated with ACE inhibitors. CONCLUSIONS: These findings
suggest that ACE inhibitors augment reactive hyperemia, an index of endothelium
dependent vasorelaxation, in patients with essential hypertension. This
augmentation may be due to increases in NO.
PMID- 10676672
TI - Endothelial vasodilator function is related to low-density lipoprotein particle
size and low-density lipoprotein vitamin E content in type 1 diabetes.
AB - OBJECTIVES: We sought to determine whether endothelial vasodilator function (EVF)
in patients with type 1 diabetes was related to low-density lipoprotein (LDL)
particle size (LDLPS), LDL vitamin E content (LDLVE) or the susceptibility of LDL
to oxidation (OxLDL). BACKGROUND: Impaired EVF is an early feature of diabetic
vascular disease and may be related to oxidant stress. Although small, dense LDL
and oxidized LDL are features of type 2 diabetes and predict the development of
coronary artery disease, their role in type 1 diabetes is less clear. METHODS:
Endothelium-dependent vasodilation was assessed in the brachial artery (flow
mediated vasodilation [FMD]) and in the forearm resistance circulation using
venous occlusion plethysmography in response to graded doses of intrabrachial
acetylcholine (ACh). Thirty-seven patients with type 1 diabetes mellitus (DM) and
45 matched controls underwent flow-mediated dilation, while a subset of 19 DM and
20 controls underwent plethysmography. RESULTS: Total, LDL and high-density
lipoprotein cholesterol or triglycerides were not different in DM compared with
controls, but LDLPS was smaller (25.6 +/- 0.06 vs. 26.1 +/- 0.1 nm, p < 0.05) and
LDLVE was reduced (2.0 +/- 0.25 vs. 2.6 +/- 0.18 micromol/mmol LDL, p < 0.05).
Oxidative susceptibility of LDL was not different. Flow-mediated vasodilation was
impaired in DM compared with controls (3.6 +/- 0.6% vs. 7.1 +/- 0.5%, p < 0.005),
as was the vasodilator response to ACh (p < 0.05). Flow-mediated vasodilation was
directly related to LDLPS and LDLVE in both the entire study cohort and DM alone
(p < 0.05), but not to other parameters of the standard lipid profile. Similarly,
endothelium-dependent vasodilation in the resistance circulation was directly
related to LDLPS and LDLVE, but not to OxLDL. CONCLUSION: These results suggest,
but do not prove, that LDL particle size and LDL vitamin E may be determinants of
conduit and resistance vessel endothelial vasodilator function in type 1
diabetes. Further work will be required to prove cause and effect.
PMID- 10676673
TI - Blood glucose and platelet-dependent thrombosis in patients with coronary artery
disease.
AB - OBJECTIVES: To investigate the influence of blood glucose on platelet-dependent
thrombosis (PDT). BACKGROUND: Elevated blood glucose is a predictor of adverse
cardiovascular risk independent of a diagnosis of diabetes, possibly due to
adverse effects promoting thrombosis. The effects of blood glucose on PDT have
not been characterized. METHODS: An ex vivo extracorporeal perfusion protocol was
used to measure PDT in 42 patients with stable coronary artery disease (CAD). The
Badimon chamber was perfused with unanticoagulated venous blood and PDT evaluated
using computerized morphometry. Whole blood impedance aggregometry and flow
cytometry evaluated platelet aggregation and P-selectin expression, respectively.
RESULTS: Using a multivariate stepwise regression model, blood glucose was the
best independent predictor of PDT (R2 = 0.19, p < 0.008), followed by
apolipoprotein B (R2 = 0.18, p = 0.002) and intracellular magnesium levels (R2 =
0.12, p = 0.02). Platelet-dependent thrombosis was significantly greater in
patients with blood glucose >, compared with <, the median value of 4.9 mmol/l
(159 +/- 141 vs. 67 +/- 69 microm2/mm, p < 0.01). Neither platelet aggregation
nor P-selectin expression was significantly different between the two groups.
Insulin levels correlated with blood glucose (r = 0.56, p = 0.0003), but were not
independently associated with either PDT, platelet aggregation or P-selectin
expression. A two-way analysis of variance demonstrated an interaction between
insulin (>126 pmol/l) and blood glucose (>4.9 mmol/l) in modulating PDT (F [1,38]
= 8.5, p < 0.006). CONCLUSIONS: Blood glucose is an independent predictor of PDT
in stable CAD patients. The relationship is evident even in the range of blood
glucose levels considered normal, indicating that the risk associated with blood
glucose may be continuous and graded. These findings suggest that the increased
CAD risk associated with elevated blood glucose may be, in part, related to
enhanced platelet-mediated thrombogenesis.
PMID- 10676674
TI - Snoring and risk of cardiovascular disease in women.
AB - OBJECTIVES: To examine prospectively the association between snoring and
incidence of cardiovascular disease (CVD) in women. BACKGROUND: Whether snoring
increases risk of CVD remains unclear; most previous studies have been small, not
prospective and limited to men. METHODS: Seventy-one thousand seven hundred
seventy-nine female nurses 40 through 65 years of age and without previously
diagnosed CVD or cancer at baseline in 1986 were followed up for eight years.
Frequency of snoring was assessed using mailed questionnaires at baseline.
RESULTS: During eight years of follow-up, we documented 1,042 incident cases of
major CVD events (644 coronary heart disease [CHD] and 398 stroke). Compared with
nonsnorers, the age-adjusted relative risks (RRs) of CVD were 1.46 (95%
confidence interval 1.23 to 1.74) for occasional snorers and 2.02 (1.62 to 2.53)
for regular snorers. The age-adjusted RRs of CHD were 1.43 (1.15 to 1.77) for
occasional snorers and 2.18 (1.65 to 2.87) for regular snorers. The age-adjusted
RRs of stroke were 1.60 (1.21 to 2.12) and 1.88 (1.29 to 2.74), respectively.
After further adjustment for smoking, body mass index (BMI) and other covariates,
the positive association between snoring and CVD was attenuated but remained
statistically significant (RRs of CVD were 1.20 [1.01 to 1.43] for occasional
snorers and 1.33 [1.06-1.67] for regular snorers. CONCLUSIONS: These data
suggested that snoring is associated with a modest but significantly increased
risk of CVD in women, independent of age, smoking, BMI and other cardiovascular
risk factors. While further study is needed to elucidate the biological mechanism
underlying this association, snoring may help clinicians identify individuals at
higher risk for CVD.
PMID- 10676675
TI - Lack of association of lipoprotein(a) levels with coronary calcium deposits in
asymptomatic postmenopausal women.
AB - OBJECTIVES: This study sought to determine the relationship of lipoprotein(a)
(Lp(a)) and other cardiac risk factors to coronary atherosclerosis as measured by
calcification of coronary arteries in asymptomatic postmenopausal women.
BACKGROUND: Lipoprotein(a) is considered a risk factor for coronary heart
disease. Coronary calcium deposition is believed to be a useful noninvasive
marker of coronary atherosclerosis in women. However, to our knowledge, there are
no reports of the relationship of Lp(a) to coronary calcium in postmenopausal
women. METHODS: In 178 asymptomatic postmenopausal women (64 +/- 8 years), we
measured Lp(a) and other cardiac risk factors: age, hypertension, diabetes, low
density lipoprotein cholesterol, smoking status, body mass index, physical
activity level and duration of hormone replacement therapy. Electron-beam
computed tomography was done to measure coronary calcium (calcium score). We
analyzed the relationship between calcium score and cardiac risk factors using
multivariate analysis. RESULTS: Although calcium score correlated with
traditional risk factors of age, diabetes, hypertension and smoking, it did not
correlate with Lp(a) in the asymptomatic postmenopausal women. Similar
multivariate analyses were done in the subjects age >60 years and in the subjects
with significant coronary calcium deposit (calcium score > or =50). These
analyses also have failed to show an association of levels of Lp(a) with coronary
calcium deposits. CONCLUSIONS: We conclude that in asymptomatic postmenopausal
women, Lp(a) levels do not correlate with coronary atherosclerosis as measured by
coronary calcium deposits.
PMID- 10676676
TI - Garlic powder, effect on plasma lipids, postprandial lipemia, low-density
lipoprotein particle size, high-density lipoprotein subclass distribution and
lipoprotein(a).
AB - OBJECTIVES: To test the hypothesis that a garlic supplement alters plasma
lipoproteins, postprandial lipemia, low-density lipoprotein (LDL) size and high
density lipoprotein (HDL) subclass distribution differently in 50 moderately
hypercholesterolemic subjects classified as LDL subclass pattern A or B.
BACKGROUND: Garlic has been variably reported to reduce or not affect plasma
cholesterol values. Low-density lipoprotein pattern B is a common inherited
disorder of lipoprotein metabolism that has been shown to have a significantly
greater response to several lipid lowering treatments including low fat diet when
compared with LDL pattern A individuals. METHODS: A double blind, randomized,
placebo controlled trial in an outpatient lipid research clinic was performed and
included fifty moderately hypercholesterolemic subjects (mean LDL cholesterol =
166 +/- 22 mg/dl) classified as LDL subclass pattern A (predominantly large LDL,
n = 22) or B (predominantly small LDL, n = 28). Following a two-month
stabilization period, subjects were randomly assigned to a placebo or 300 mg
three times a day of a standardized garlic tablet for three months. RESULTS: For
all subjects, LDL pattern A and B subjects combined, garlic treatment for three
months resulted in no significant change in total cholesterol, LDL cholesterol,
HDL cholesterol, HDL subclass distribution, postprandial triglycerides,
apolipoprotein B, lipoprotein (a) (Lp[a]), LDL peak particle diameter or LDL
subclass distribution. There was no significant difference in response for the
same parameters among subjects classified as LDL pattern A or B with the
exception of significantly greater (p = 0.01) reduction in mean peak particle
diameter in pattern A subjects treated with either garlic or placebo. There was
no significant change in LDL subclass distribution. CONCLUSIONS: This
investigation confirms that garlic therapy has no effect on major plasma
lipoproteins and further, that it has no impact on HDL subclasses, Lp(a),
apolipoprotein B, postprandial triglycerides or LDL subclass distribution. Garlic
may have a greater effect on LDL particle diameter in LDL pattern A compared with
pattern B subjects. This difference was not reflected in other plasma lipid
measurements.
PMID- 10676677
TI - Coronary microcirculatory vasoconstriction during ischemia in patients with
unstable angina.
AB - OBJECTIVE: To verify the behavior of coronary microvascular tone during
spontaneous ischemia in patients with unstable angina (UA). BACKGROUND: In UA,
the pathogenetic role of vasoconstriction is classically confined at the stenotic
coronary segment. However, microcirculatory vasoconstriction has been also
suggested by previous experimental and clinical studies. METHODS: The study
included 10 patients with UA (recent worsening of anginal threshold and
appearance of angina at rest) and single-vessel CAD. Blood flow velocity was
monitored by a Doppler catheter in the diseased artery. Transstenotic pressure
gradient was monitored by aortic and distal coronary pressure monitoring.
Stenosis resistance was calculated as the ratio between pressure gradient and
blood flow, microvascular resistance as the ratio between distal pressure and
blood flow. Measurements were obtained at baseline, following intracoronary
adenosine (2 mg) and during transient ischemia. Aortic and distal coronary
pressures were also measured during balloon coronary occlusion. RESULTS:
Adenosine did not affect stenosis resistance, while it decreased (p < 0.05)
microvascular resistance to 52 +/- 22% of baseline. Angina and ischemic ST
segment shift were associated with transient angiographic coronary occlusion in 7
of 10 patients; however, in no case was ischemia associated with interruption of
flow. Despite markedly different flow values, distal coronary pressure was
similar during adenosine and during spontaneous ischemia (48 +/- 15 vs. 46 +/- 20
mm Hg, respectively, NS). During ischemia, a marked increase in the resistance of
both coronary stenosis and coronary microcirculation was observed (to 1,233% +/-
1,298% and 671% +/- 652% of baseline, respectively, p < 0.05). Distal coronary
pressure was markedly reduced during balloon coronary occlusion (14 +/- 7 mm Hg,
p < 0.05 vs. both adenosine and ischemia), suggesting the absence of significant
collateral circulation. CONCLUSIONS: In patients with UA, transient myocardial
ischemia is associated with vasoconstriction of both stenotic arterial segment
and downstream microcirculation.
PMID- 10676678
TI - Identification of severe coronary artery disease in patients with a single
abnormal coronary territory on exercise thallium-201 imaging: the importance of
clinical and exercise variables.
AB - OBJECTIVES: The aim of this study was to determine which clinical, exercise and
thallium variables can aid in the identification of three-vessel or left main
coronary artery disease (3VLMD) in patients with one abnormal coronary territory
(either a reversible or fixed defect) on exercise thallium testing and to test
the prognostic value of these variables. BACKGROUND: Although the sensitivity of
detection of coronary artery disease by thallium-201 imaging is high, the actual
detection of 3VLMD by thallium tomographic images alone is not optimal. METHODS:
A multivariate model for prediction of 3VLMD was developed from several clinical,
exercise and thallium-201 variables in a training population of 264 patients who
had one abnormal coronary artery territory on exercise thallium testing and had
undergone coronary angiography. Using this model, patients were stratified into
risk groups for prediction of 3VLMD. A separate validation cohort of 474
consecutive patients who were treated initially with medical therapy and who had
one abnormal coronary territory were divided into identical risk groupings by the
variables derived from the training population, and they were followed for a
median of 7.0 years to evaluate the prognostic value of this model. RESULTS: The
prevalence of 3VLMD was 26% in the training population despite one abnormal
thallium coronary territory. Four clinical and exercise variables--diabetes,
hypertension, magnitude of ST segment depression, and exercise rate-pressure
product-were found to be independent predictors of 3VLMD. In the training
population, the prevalence of 3VLMD in low-, intermediate- and high-risk groups
was 15%, 22% and 51%, respectively. When the multivariate model was applied to
the validation population, the eight-year overall survival rates in the low-,
intermediate- and high-risk groups were 89%, 73% and 75%, respectively (p <
0.001). CONCLUSIONS: A substantial proportion of patients with one abnormal
thallium coronary territory have 3VLMD with subsequent divergent outcomes based
upon risk stratification by clinical and exercise variables. Consequently, the
finding of only a single abnormal coronary territory by thallium-201 perfusion
imaging does not necessarily confer a benign prognosis in the absence of
consideration of nonimaging variables.
PMID- 10676679
TI - Three minute, but not one minute, ischemia and nicorandil have a preconditioning
effect in patients with coronary artery disease.
AB - OBJECTIVES: This study focused on 1) the determination of the optimal
preconditioning (PC) duration, and 2) the protective effect of nicorandil (NC), a
hybrid nitrate with a KATP channel opening effect, during a percutaneous
transluminal coronary angioplasty (PTCA) model in humans. BACKGROUND: The
ischemic PC effect is induced in 180 s ischemia, but not in 120 s ischemia in
rabbit hearts. However, the duration of ischemia that induces PC effect and the
role of the KATP channel in the PC effect in humans are still unclear. METHODS:
Forty-six patients with stable angina were randomly allocated to four groups: the
duration of the first inflation as PC ischemia was 60 s in the PC60 group (n =
12), and 180 s in the PC180 group (n = 12). In the other groups, NC (80
microg/kg) was intravenously given for 1 min in the NC group (n = 12), and
isosorbide dinitrate (ISDN) (40 microg/kg) was given in the ISDN group (n = 10).
Five minutes after first inflation or drug administration, a second inflation was
conducted for 120 s in each group. In the ECG, the lead with the largest shift in
ST segment (deltaST max), and the sum of elevated ST levels in all leads
(sigmaST) were determined. RESULTS: In the PC60 group, no significant difference
was observed in either deltaST max or sigmaST between the first and second
inflation. However, the second inflation in the PC180 group showed significantly
lower levels of deltaST max and sigmaST compared with those of the first
inflation. In the NC group, both deltaST max and sigmaST measured at 30 s and 60
s after balloon inflation were significantly lower than those of the first
inflation in the PC60 and PC180 control groups. In the ISDN group, no significant
difference was observed in deltaST max or sigmaST. CONCLUSION: In human PTCA
models, a PC effect is observed in 180 s ischemia, but not in 60 s ischemia. A
pharmacological PC effect is induced by NC, a KATP channel opener with a nitrate
like effect but not ISDN. This suggests that the opening of KATP channels plays
an important role in the protecting effect of NC.
PMID- 10676680
TI - Persistent ST segment depression in precordial leads V5-V6 after Q-wave anterior
wall myocardial infarction is associated with restrictive physiology of the left
ventricle.
AB - OBJECTIVES: To examine the relationship between the persistence of ST segment
depression in leads V5-V6 after Q-wave anterior wall myocardial infarction (MI)
and the filling pattern of the left ventricle (LV). BACKGROUND: Precordial ST
segment depression predominantly in leads V5-V6 is associated with increased in
hospital morbidity and mortality after acute myocardial ischemia, perhaps due to
reduced diastolic distensibility of the LV. METHODS: We prospectively studied 19
patients after Q-wave anterior wall MI (>6 months). All patients underwent 12
lead ECG recording, symptom-limited treadmill exercise testing with single photon
emission computed tomography thallium-201 imaging, transthoracic Doppler
echocardiography, cardiac catheterization and measurement of circulating atrial
natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels. Patients
were classified based on the presence of ST segment depression in leads V5-V6:
Group I = ST segment depression <0.1 mV (n = 10); Group II = ST segment
depression > or =0.1 mV (n = 9). RESULTS: Patients in Group II had greater LV end
diastolic pressures (32.4 +/- 6.5 mm Hg vs. 14.8 +/- 6.1 mm Hg; p = 0.0001),
higher plasma ANP (44.4 +/- 47.1 pg/ml vs. 10.7 +/- 14 pg/ml; p = 0.04) and BNP
levels (89.4 +/- 62.7 pg/ml vs. 23.6 +/- 33.1 pg/ml; p = 0.01), greater left
atrium area (20.6 +/- 3.1 cm2 vs. 17.8 +/- 2.4 cm2; p = 0.05), lower peak atrial
(A), higher early (E) mitral inflow velocities, a higher E/A ratio and a lower
deceleration time (167 +/- 44 ms vs. 220 +/- 40 ms; p = 0.05). Lung thallium
uptake during exercise was more common in Group II (78% vs. 10%, p = 0.04).
CONCLUSIONS: Persistent ST segment depression in leads V5-V6 in survivors of Q
wave anterior wall MI is associated with increased LV filling pressure and a
restrictive LV filling pattern.
PMID- 10676681
TI - Serum amyloid A predicts early mortality in acute coronary syndromes: A TIMI 11A
substudy.
AB - OBJECTIVES: We evaluated the ability of serum amyloid A (SAA), alone and in
combination with a rapid qualitative assay for cardiac-specific troponin T
(cTnT), to predict 14-day mortality in patients with unstable angina or non-Q
wave myocardial infarction (NQMI). BACKGROUND: Elevated C-reactive protein (CRP)
has been associated with adverse outcomes in unstable coronary syndromes but data
regarding its acute phase counterpart, SAA, are conflicting. METHODS: Serum
amyloid A measurement and a rapid cTnT assay were performed on blood obtained at
enrollment into Thrombolysis in Myocardial Infarction 11A, a dose-ranging trial
of enoxaparin for unstable angina and NQMI. RESULTS: Serum amyloid A was higher
in patients who died compared with survivors (6.28 vs. 0.75 mg/dL, p = 0.002).
Among patients with a negative rapid cTnT, mortality was higher for those in the
top quintile of SAA (6.1 vs. 0.7%, p = 0.003). Patients with both an early
positive rapid cTnT (< or =10 min until assay positive) and SAA in the fifth
quintile had the highest mortality followed by those with either markedly
elevated SAA or an early positive rapid cTnT, while patients with both a negative
rapid cTnT and SAA in quintiles 1-4 were at very low risk, (9.1 vs. 3.6 vs. 0.7%,
p <0.002). CONCLUSIONS: Similar to CRP, baseline elevation of SAA identifies
patients hospitalized with unstable angina and NQMI at higher risk for early
mortality, even among those with a negative rapid assay for cTnT. These data
support further investigation of inflammatory markers used alone and in
combination with cardiac troponins for risk assessment in unstable coronary
syndromes.
PMID- 10676682
TI - Ratio of left ventricular peak E-wave velocity to flow propagation velocity
assessed by color M-mode Doppler echocardiography in first myocardial infarction:
prognostic and clinical implications.
AB - OBJECTIVES: To determine the ability of the ratio of peak E-wave velocity to flow
propagation velocity (E/Vp) measured with color M-mode Doppler echocardiography
to predict in-hospital heart failure and cardiac mortality in an unselected
consecutive population with first myocardial infarction (MI). BACKGROUND: Several
experimental studies indicate color M-mode echocardiography to be a valuable tool
in the evaluation of diastolic function, but data regarding the clinical value
are lacking. METHODS: Echocardiography was performed within 24 h of arrival at
the coronary care unit in 110 consecutive patients with first MI. Highest Killip
class was determined during hospitalization. Patients were divided into groups
according to E/Vp <1.5 and > or =1.5. RESULTS: During hospitalization 53 patients
were in Killip class > or =II. In patients with E/Vp > or =1.5, Killip class was
significantly higher compared with patients with E/Vp <1.5 (p < 0.0001).
Multivariate logistic regression analysis identified E/Vp > or =1.5 to be the
single best predictor of in-hospital clinical heart failure when compared with
age, heart rate, E-wave deceleration time (Dt), left ventricular (LV) ejection
fraction, wall motion index, enzymatic infarct size and Q-wave MI. At day 35
survival in patients with E/Vp <1.5 was 98%, while for patients with E/Vp > or
=1.5, it was 58% (p < 0.0001). Cox proportional hazards model identified Dt <140
ms, E/Vp > or =1.5 and age to be independent predictors of cardiac death, with Dt
< 140 ms being superior to age and E/Vp. CONCLUSIONS: In the acute phase of MI,
E/Vp > or =1.5 measured with color M-mode echocardiography is a strong predictor
of in-hospital heart failure. Furthermore, E/Vp is superior to systolic
measurements in predicting 35 day survival although Dt <140 ms is the most
powerful predictor of cardiac death.
PMID- 10676683
TI - Treatment and outcome of myocardial infarction in hospitals with and without
invasive capability. Investigators in the National Registry of Myocardial
Infarction.
AB - OBJECTIVES: We sought to determine the extent to which the capability of a
hospital to perform invasive cardiovascular procedures influences treatment and
outcome of patients admitted with acute myocardial infarction (AMI). BACKGROUND:
Patients with AMI are usually transported to the closest hospital. However,
relatively few hospitals have the capability for immediate coronary
arteriography, percutaneous transluminal coronary angioplasty (PTCA) or coronary
artery bypass graft surgery (CABG), should these interventions be needed.
METHODS: The 1,506 hospitals participating in the National Registry of Myocardial
Infarction 2 were classified according to their highest level of invasive
capability: 1) none (noninvasive, 28.1%); 2) coronary arteriography (cath
capable, 25.2%); 3) coronary angioplasty (PTCA-capable, 7.4%); and 4) bypass
surgery (CABG-capable, 39.2%). Treatment and in-hospital outcomes were assessed
for 305,812 patients admitted from June 1994 through October 1996. Follow-up
through 90 days was ascertained in a subset of 30,402 patients enrolled
simultaneously in both the National Registry of Myocardial Infarction (NRMI) 2
and the Cooperative Cardiovascular Project (CCP). RESULTS: The proportion of
patients receiving initial reperfusion intervention was only slightly higher at
the more invasive hospitals (noninvasive 32.5%, cath-capable 31.2%, PTCA-capable
32.9% and CABG-capable 35.9%, p < 0.001 by chi-square statistic). Among
thrombolytic recipients, median door-to-drug time interval differed little among
hospital types and ranged from 42 to 45 minutes. At cath-capable, PTCA-capable
and CABG-capable hospitals, coronary arteriography was performed in 32.9%, 37.4%
and 64.9%, respectively, and PTCA in 0.0%, 5.1% and 31.4%, both p < 0.001 by chi
square statistic. The proportion of patients transferred out to other facilities
was 51.0%, 42.2%, 39.9% and 4.4% (p < 0.0001) among noninvasive, cath-capable,
PTCA-capable and CABG-capable hospitals, respectively. Among patients in the
combined NRMI and CCP data set, mortality at 90 days postinfarction was similar
among patients initially admitted to each of the four hospital types.
CONCLUSIONS: Although patients with AMI admitted to hospitals without invasive
cardiac facilities have a high likelihood of subsequent transfer to other
facilities, their likelihood of receiving a reperfusion intervention at the first
hospital, their door to thrombolytic drug intervals and their 90-day survival
rates are similar to those of patients initially admitted to more invasively
equipped hospitals. These data suggest that a policy of initial treatment of
myocardial infarction at the closest medical facility is appropriate medical
practice.
PMID- 10676684
TI - Management of myocardial infarction: looking beyond efficacy.
PMID- 10676685
TI - Greater late lumen loss after successful coronary balloon angioplasty in the
proximal left anterior descending coronary artery is not explained by extent of
vessel wall damage or plaque burden.
AB - OBJECTIVES: We investigated whether the greater late lumen loss after coronary
balloon angioplasty in the proximal left anterior descending artery (P-LAD)
compared with that in other segments might be related to differences in vascular
dimensions or morphology as determined by angiography and intravascular
ultrasound imaging. BACKGROUND: The greater late lumen loss after angioplasty in
the P-LAD that has been observed in several studies has not been explained.
METHODS: We studied 178 patients and 194 coronary artery lesions by quantitative
angiography and 30 MHz intravascular ultrasound imaging after successful balloon
angioplasty. Vessel wall morphology was compared among three proximal and three
nonproximal segments. Follow-up quantitative angiography for late lumen loss
calculation was performed in 168 lesions. Multivariate analysis was used to
determine predictors of late lumen loss. RESULTS: Absolute and relative late loss
were significantly greater at the P-LAD compared with the pooled group of other
segments (0.42 +/- 0.60 mm vs. 0.10 +/- 0.48 mm, p = 0.0008 and 0.14 +/- 0.24 vs.
0.03 +/- 0.17, p < 0.001). Also, a greater percentage of calcific lesions (65%
vs. 44%, p = 0.034), a lower incidence of rupture (51% vs. 74%, p = 0.009) and a
larger reference segment plaque area (5.4 +/- 2.2 mm2 vs. 4.7 +/- 1.9 mm2, p =
0.05) were found in the P-LAD. In multivariate analysis however, these variables
were not predictive of late loss. CONCLUSIONS: Greater late lumen loss after
coronary balloon angioplasty of the P-LAD is not explained by differences in
atherosclerotic plaque burden or in vessel wall damage.
PMID- 10676686
TI - Procedural results and intermediate clinical outcomes after multiple saphenous
vein graft stenting.
AB - OBJECTIVES: We evaluated the early and mid-term (18-month) clinical events in a
consecutive series of patients undergoing a nonstaged multiple saphenous vein
grafting (SVG) intervention with stents as compared with a single SVG stent
procedure. BACKGROUND: Saphenous vein graft angioplasty has been limited by high
rates of distal embolization, myocardial infarction, restenosis and late
mortality. It is unknown whether stenting of multiple, different SVGs at the same
setting is associated with higher risk. METHODS: We evaluated in-hospital and mid
term clinical outcomes (death, Q wave myocardial infarction [MI] and repeat
revascularization rates up to 18 months) in 70 consecutive patients treated with
coronary stents in 2 (93% of patients) or 3 SVGs, as compared with 649 patients
undergoing stenting of a single SVG between January 1, 1994 and December 31,
1997. RESULTS: Overall procedural success was obtained in 97% of patients with 2
or 3 SVGs and 97% of patients with a single SVG (p = 0.94). Procedural
complications were also similar (2.8% for multiple SVGs vs. 2.7% for a single
SVG, p = 0.94). There was a higher prevalence of periprocedural non-Q wave MI
(28% vs. 16%, p = 0.009) in the multiple SVG group. During follow-up (18 months),
target lesion revascularization was 11% in multiple SVG and 15% in single SVG
interventions (p = 0.19), and repeat revascularization (calculated per treated
patient) was also similar for both groups (19% vs. 18%, p = 0.94). There was no
difference in death (5.6% vs. 5.3%, p = 0.92) and Q wave MI rate (4.3% vs. 2.9%,
p = 0.55) after the multiple SVG intervention. Overall cardiac event-free
survival was similar for both groups (62% vs. 60%, p = 0.75). The study was
powered to detect a clinically meaningful difference of 10% in mortality; smaller
differences could not be evaluated on the basis of this sample size. CONCLUSIONS:
Simultaneous stenting of multiple SVGs in carefully selected patients has similar
in-hospital procedural success and major complications rates, as well as mid-term
(18-month) clinical outcomes, as compared with single SVG stenting. Thus,
multiple SVG interventions using stents may be a viable revascularization
strategy for carefully selected patients and suitable lesions in multiple SVG
disease.
PMID- 10676687
TI - The effects of moxonidine, a novel imidazoline, on plasma norepinephrine in
patients with congestive heart failure. Moxonidine Investigators.
AB - OBJECTIVE: To evaluate the dose response relationship of moxonidine on plasma
concentration of norepinephrine during acute and chronic administration in
patients with congestive heart failure (CHF). BACKGROUND: Sympathetic activation
is increased in heart failure. Moxonidine is an imidazoline ligand acting on the
central nervous system (CNS) receptors to decrease sympathetic activation.
METHODS: Ninety-seven patients with heart failure and New York Heart Association
class II-III symptoms and ejection fraction <40% were randomized to placebo or
one of three target doses of moxonidine, 0.1, 0.2 or 0.3 mg administered twice
daily. An initial dose of moxonidine 0.1 mg twice a day (b.i.d.) was followed by
weekly increments of 0.1 mg b.i.d. until target dose. The second and third study
days occurred after four weeks (at target dose) and after 12 weeks, respectively.
At each study day, repeated blood samples were drawn. RESULTS: There was a
significant dose-related decrease of systolic blood pressure across all three
study days. Heart rate decreased significantly on study day 3 in a dose-related
manner. The acute 2 h decrease in plasma norepinephrine in response to all three
doses of moxonidine was significantly different compared with placebo after four
and 12 weeks. There was a significant linear relation between dose and plasma
norepinephrine after four and 12 weeks in both 2 h peak and the time averaged
effect (>8 h). The number of adverse events was similar in the moxonidine and
placebo groups. CONCLUSIONS: The increased sympathetic activation in CHF can be
reduced by moxonidine through CNS inhibition.
PMID- 10676688
TI - Prediction of paroxysmal atrial fibrillation in patients with congestive heart
failure: a prospective study.
AB - OBJECTIVES: We sought to prospectively determine whether patients with congestive
heart failure (CHF) at risk for paroxysmal atrial fibrillation (PAF) could be
identified by clinical and study variables including the P-wave signal-averaged
electrocardiogram (P-SAECG). BACKGROUND: Although it is important to assess the
risk of developing PAF in patients with CHF, it still remains difficult to
predict the PAF appearance in patients with CHF clinically. METHODS: The study
group consisted of 75 patients in sinus rhythm without a history of PAF, whose
left ventricular ejection fraction, as measured by radionuclide angiography, was
<40%. These patients underwent P-SAECG, echocardiography and 24-h Holter
monitoring; in addition, the plasma concentration of atrial natriuretic peptide
(ANP) was measured at study entry. RESULTS: An abnormal P-SAECG was found at
study entry in 29 of 75 patients. In the follow-up period of 21 +/- 9 months, the
PAF attacks documented on the ECG significantly more frequently occurred in
patients with (32%) rather than without an abnormal P-SAECG (2%) (p = 0.0002).
The plasma ANP level was significantly higher in patients with rather than
without PAF attacks (75 +/- 41 vs. 54 +/- 60 pg/ml, p = 0.01), although there
were no significant differences in age, left atrial dimension or high grade
atrial premature beats between the groups. The multivariate Cox analysis
identified that the variables significantly associated with PAF development were
an abnormal P-SAECG (hazard ratio 19.1, p = 0.0069) and elevated ANP level > or
=60 pg/ml (hazard ratio 8.6, p = 0.018). CONCLUSIONS: An abnormal P-SAECG and
elevated ANP level could be predictors of PAF development in patients with CHF.
PMID- 10676689
TI - Mapping and ablation of ventricular tachycardia guided by virtual electrograms
using a noncontact, computerized mapping system.
AB - OBJECTIVES: The purpose of this study was to describe a computerized mapping
system that utilizes a noncontact, 64 electrode balloon catheter to compute
virtual electrograms simultaneously at 3,360 left ventricular (LV) sites and to
assess the clinical utility of this system for mapping and ablating ventricular
tachycardia (VT). BACKGROUND: Mapping VT in the electrophysiology laboratory
conventionally is achieved by sequentially positioning an electrode catheter at
multiple endocardial sites. METHODS: Fifteen patients with VT underwent 18
electrophysiology procedures using the noncontact, computerized mapping system. A
9F 64 electrode balloon catheter and a conventional 7F electrode catheter for
mapping and ablation were positioned in the LV using a retrograde aortic
approach. Using a boundary element inverse solution, 3,360 virtual endocardial
electrograms were computed and used to derive isopotential maps. An incorporated
locator system was used in conjunction with or instead of fluoroscopy to position
the conventional electrode catheter. RESULTS: A total of 21 VTs, 12 of which were
hemodynamically-tolerated and 9 of which were not, were mapped. Isolated
diastolic potentials, presystolic areas, zones of slow conduction and exit sites
during VT were identified using virtual electrograms and isopotential maps. Among
19 targeted VTs, radiofrequency ablation guided by the computerized mapping
system and the locator signal was successful in 15. CONCLUSIONS: The computerized
mapping system described in this study computes accurate isopotential maps that
are a useful guide for ablation of hemodynamically stable or unstable VT.
PMID- 10676690
TI - High dispersion of ventricular repolarization after an implantable defibrillator
shock predicts induction of ventricular fibrillation as well as unsuccessful
defibrillation.
AB - OBJECTIVES: To test the hypothesis that post-shock dispersion of repolarization
(PSDR) is higher in T wave shocks that induce ventricular fibrillation (VF) than
in those that do not, as well as in implantable cardioverter defibrillator (ICD)
defibrillation shocks which fail to terminate VF when compared with those that
are successful. BACKGROUND: Ventricular fibrillation has been linked to the
presence of dispersion of repolarization, which facilitates reentry. Most of the
studies have been done in animals, and the mechanism underlying the generation
and termination of VF in humans is speculative and remains to be determined.
METHODS: Monophasic action potentials (MAPs) were recorded simultaneously from
the right ventricular outflow tract (RVOT) and the right ventricular apex (RVA)
in 27 patients who underwent implantation and testing of an ICD. T wave shocks
were used to induce VF while the termination was attempted using internal
defibrillator shocks. The post-shock repolarization time (PSRT) was measured in
both the RVA and RVOT MAPs, and the difference between the two recordings was
defined as the PSDR. The averages of PSDR were compared between the successful
and unsuccessful inductions and terminations of VF. RESULTS: T wave shocks that
induced VF generated a greater PSDR (93.4 +/- 85.1 ms) than the unsuccessful ones
(45.1 +/- 55.9 ms, p < 0.001). On the other hand, shocks that failed to terminate
VF were associated with a greater PSDR (59.9 +/- 41.2 ms) than shocks that
terminated VF (21.1 +/- 20.1 ms), p < 0.001. CONCLUSIONS: A high PSDR following a
T wave shock is associated with induction of VF; while following a defibrillating
shock, it is associated with its failure and the continuation of VF. Conversely,
a low PSDR is associated with failure of a T wave shock to induce VF and
successful termination of VF by a defibrillating shock.
PMID- 10676691
TI - Radiofrequency catheter ablation of supraventricular tachycardia substrates after
mustard and senning operations for d-transposition of the great arteries.
AB - OBJECTIVES: The purpose of this study was to determine the efficacy and risks of
radiofrequency ablation of various forms of supraventricular tachycardia after
Mustard and Senning operations for d-transposition of the great arteries.
BACKGROUND: In this patient group, the reported success rate of catheter ablation
of intraatrial reentry tachycardia is about 70% with a negligible complication
rate. There are no reports of the use of radiofrequency ablation to treat other
types of supraventricular tachycardia. METHODS: Standard diagnostic criteria were
used to determine supraventricular tachycardia type. Appropriate sites for
attempted ablation included 1) intraatrial reentry tachycardia: presence of
concealed entrainment with a postpacing interval similar to tachycardia cycle
length; 2) focal atrial tachycardia: a P-A interval < or =-20 ms; and 3) typical
variety of atrioventricular (AV) node reentry tachycardia: combined
electrographic and radiographic features. RESULTS: Nine Mustard and two Senning
patients underwent 13 studies to successfully ablate all supraventricular
tachycardia substrates in eight (73%) patients. Eight of eleven (73%) patients
having intraatrial reentry tachycardia, 3/3 having typical AV node reentry
tachycardia, and 2/2 having focal atrial reentry tachycardia were successfully
ablated. Among five patients having intraatrial reentry tachycardia (IART) and
not having ventriculoatrial (V-A) conduction, two suffered high-grade AV block
when ablation of the systemic venous portion of the medial tricuspid
valve/inferior vena cava isthmus was attempted. CONCLUSIONS: Radiofrequency
catheter ablation can be effectively and safely performed for certain
supraventricular tachycardia types in addition to intraatrial reentry. A novel
catheter course is required for slow pathway modification. High-grade AV block is
a potential risk of lesions placed in the systemic venous medial isthmus.
PMID- 10676692
TI - Mechanism, localization and cure of atrial arrhythmias occurring after a new
intraoperative endocardial radiofrequency ablation procedure for atrial
fibrillation.
AB - OBJECTIVES: The purpose of this study was to test a new pattern of radiofrequency
ablation for atrial fibrillation (AFib) intended to optimize atrial activation,
and to demonstrate the usefulness of catheter techniques for mapping and ablation
of postoperative atrial arrhythmias. BACKGROUND: Linear radiofrequency lesions
have been used to cure AFib, but the optimal pattern of lesions is unknown and
postoperative tachyarrhythmias are common. METHODS: A radial pattern of linear
radiofrequency lesions (Star) was made using an endocardial open surgical
approach in 25 patients. Postoperative arrhythmias were induced and characterized
during electrophysiological studies in 15 patients. RESULTS: The AFib was
abolished in most patients (91%), but atrial flutter (AFlut) occurred in 96% of
patients postoperatively. At postoperative electrophysiological studies, 37
flutter morphologies were studied in 15 patients (46% spontaneous, cycle length
[CL] 223 +/- 25 ms). Seven mechanisms (lesions discontinuity, n = 6; focal
mechanism, n = 1) of AFlut were characterized in six patients. In these cases,
flutter was abolished using further catheter radiofrequency ablation. In the
remaining cases, flutter was usually localized to an area involving the
interatrial septum, but no critical isthmus was identified for ablation. After 16
+/-10 months, 15 patients (65%) were asymptomatic with (n = 3) or without (n =
12) antiarrhythmic medications. Eight (35%) patients had persistent arrhythmias.
Postoperative atrial electrical activation was near physiological. CONCLUSIONS:
The AFib maybe abolished using a radial pattern of linear endocardial
radiofrequency lesions, but postoperative AFlut is common even when lesions are
made under optimal conditions. Endocardial mapping techniques can be used to
characterize the flutter mechanisms, thus enabling subsequent successful catheter
ablation.
PMID- 10676693
TI - Radiofrequency catheter ablation of inappropriate sinus tachycardia guided by
activation mapping.
AB - OBJECTIVE: The purpose of this study was to evaluate the value of activation
mapping for radiofrequency modification of the sinus node and the long-term
success rate of the procedure in a series of patients with inappropriate sinus
tachycardia. BACKGROUND: The results of radiofrequency ablation of inappropriate
sinus tachycardia have been reported in only a small number of patients. METHODS:
The subjects of this study were 29 consecutive drug-refractory patients who
underwent catheter ablation of inappropriate sinus tachycardia. Target sites were
selected by activation mapping during sinus tachycardia. RESULTS: The ablation
procedure was successful acutely in reducing the baseline sinus rate to <90/min
and the sinus rate during isoproterenol infusion by >20% in 22 of 29 patients
(76%). In 13 of 22 patients (59%) with a successful acute outcome, successive
applications of radiofrequency energy at the site of earliest endocardial
activation resulted in a cranial-caudal migration of earliest endocardial
activation from the high lateral right atrium, along with a step-wise reduction
in heart rate. In the other nine patients (41%) with a successful acute outcome,
the reduction in sinus rate occurred abruptly, unaccompanied by migration of the
site of earliest activation. Symptoms due to inappropriate sinus tachycardia
recurred at a mean of 4.4+/-; 3 months after the ablation procedure in 6 of 22
patients (27%). After additional procedures in three patients, symptoms of
inappropriate sinus tachycardia ultimately were successfully eliminated over the
long-term in 19 of 29 patients (66%). CONCLUSIONS: In conclusion, radiofrequency
ablation is at best only modestly effective for managing patients with
inappropriate sinus tachycardia. The two different responses of heart rate to
radiofrequency ablation may reflect differences in the number and/or
multicentricity of subsidiary sites of impulse generation within the sinus node
and/or atrium in patients with inappropriate sinus tachycardia.
PMID- 10676694
TI - Efficacy and safety of catheter ablation in octogenarians.
AB - OBJECTIVES: To determine whether catheter ablation is safe and effective in
patients over the age of 80. BACKGROUND: There is a tendency to withhold invasive
therapy in the elderly until it has been proven safe and effective. METHODS: Over
a two-year period from February 1, 1996 to February 1, 1998, 695 consecutive
patients underwent 744 catheter ablation procedures of supraventricular and
ventricular arrhythmias. These patients were divided into three groups based on
age: > or =80 years, 60 to 79 years and <60 years. Acute ablation success, using
standard criteria and complication rates for these three groups were determined.
RESULTS: There were 37 patients > or =80 years, 275 patients 60 to 79 years and
383 patients <60 years old. The overall acute ablation success rate for the
entire group was 95% with no difference in rates among the three groups (97%, >
or =80 years; 94%, 60-79 years; 95%, <60 years). The percentage of patients
undergoing His bundle ablation was greatest in the > or =80-year-old group (43%
vs. 19% vs. 2%, p < 0.01), and the percentage of patients undergoing accessory
pathway ablation was greatest in the <60-year-old patients (0% vs. 4% vs. 25%, p
< 0.01). The overall complication rate for the entire group was 2.6%, and there
was only one major/life-threatening complication. There was no difference in
complication rates among the groups (0%, > or =80 years; 2.2%, 60 to 79 years;
3.1%, <60 years). Based on the sample size, the 95% confidence interval is 0% to
7.8% for an adverse event in the octogenarian. CONCLUSIONS: Catheter ablative
therapy for the arrhythmias attempted in the very elderly appears to be effective
with low risk. Ablation results appear to be comparable with those noted in
younger patients.
PMID- 10676695
TI - Pulmonary blood flow alters nitric oxide production in patients undergoing device
closure of atrial septal defects.
AB - OBJECTIVE: To determine the effect of pulmonary blood flow (Qp) on nitric oxide
(NO) production in patients with increased Qp due to an atrial septal defect
(ASD). BACKGROUND: Alterations in pulmonary vascular NO production have been
implicated in the development of pulmonary hypertension secondary to increased
Qp. In vitro, acute changes in flow or shear stress alter NO production. However,
the effect of Qp on lung NO production in vivo is unclear. METHODS: Nineteen
patients (2.4-61 years of age, median 17) with secundum ASD undergoing device
closure were studied. Before, and 30 min after ASD closure, exhaled NO and plasma
nitrate concentration were measured by chemiluminescence (NOA 280, Sievers,
Boulder, Colorado). RESULTS: Before ASD closure, all patients had increased Qp
(Qp: systemic blood flow [Qs] of 2.0 +/- 0.7) and normal mean pulmonary arterial
pressure (13.4 +/- 3.1 mm Hg). Atrial septal defect device closure decreased Qp
from 6.0 +/- 2.5 to 3.6 +/- 1.3 L/min/m2 (p < 0.05). Mean pulmonary arterial
pressure was unchanged. Associated with the decrease in Qp, both exhaled NO (
22.1%, p < 0.05) and plasma nitrate concentrations (-17.9%, p < 0.05) decreased.
CONCLUSIONS: These data represent the first demonstration that acute changes in
Qp alter pulmonary NO production in vivo in humans. Exhaled NO determinations may
provide a noninvasive assessment of pulmonary vascular NO production in patients
with congenital heart disease. Potential correlations between exhaled NO,
pulmonary vascular reactivity and pulmonary hypertension warrant further study.
PMID- 10676696
TI - Pulmonary atresia with intact ventricular septum percutaneous radiofrequency
assisted valvotomy and balloon dilation versus surgical valvotomy and Blalock
Taussig shunt.
AB - OBJECTIVE: We compared the result of radiofrequency (RF)-assisted valvotomy and
balloon dilation with closed surgical valvotomy and Blalock Taussig (BT) shunt as
primary treatment in selected patients with pulmonary atresia and intact
ventricular septum (PA-IVS). BACKGROUND: Patients with PA-IVS who have mild to
moderate hypoplasia of the right ventricle (RV) and patent infundibulum have the
greatest potential for complete biventricular circulation. The use of RF or laser
wires to perforate the atretic valve followed by balloon dilation provides an
alternative to surgery. METHODS: Between May 1990 and March 1998, 33 selected
patients underwent either percutaneous RF valvotomy and balloon dilation (group
1, n = 21; two crossed over to group 2) or surgical valvotomy with concomitant BT
shunt (group 2, n = 14). Second RV decompression by balloon dilation or right
ventricular outflow tract (RVOT) reconstruction were performed if necessary.
Patients who remained cyanosed were subjected to transcatheter trial closure of
the interatrial communication. Partial biventricular repair was offered to those
with inadequate growth of the RV. RESULTS: The primary procedure was successful
in 19 patients in group 1. There was one in-hospital death and two late deaths.
Of the remaining 16 survivors, 12 achieved complete biventricular circulation, 7
of whom required no further interventions. Two patients required repeat balloon
dilation, 1 RVOT reconstruction and 2 transcatheter closure of interatrial
communication. Two patients underwent partial biventricular repair. In group 2,
there were 3 in-hospital deaths after the primary procedure and 1 patient died
four months later. All survivors (n = 10) required a second RV decompression, 8
by balloon dilation and 2 by RVOT reconstruction, after which, two patients died.
Of the final 8 survivors, 7 achieved complete biventricular circulation, 5 after
coil occlusion of the BT shunt and 2 after closure of interatrial communication.
CONCLUSIONS: Radiofrequency valvotomy and balloon dilation is more efficacious
and safe compared with closed pulmonary valvotomy and BT shunt in selected
patients with PA-IVS.
PMID- 10676697
TI - Importance of imaging method over imaging modality in noninvasive determination
of left ventricular volumes and ejection fraction: assessment by two- and three
dimensional echocardiography and magnetic resonance imaging.
AB - OBJECTIVES: This study sought to determine the concordance between biplane and
volumetric echocardiography and magnetic resonance imaging (MRI) strategies and
their impact on the classification of patients according to left ventricular (LV)
ejection fraction (EF) (LVEF). BACKGROUND: Transthoracic echocardiography and MRI
are noninvasive imaging modalities well suited for serial evaluation of LV volume
and LVEF. Despite the accuracy and reproducibility of volumetric methods,
quantitative biplane methods are commonly used, as they minimize both scanning
and analysis times. METHODS: Thirty-five adult subjects, including 25 patients
with dilated cardiomyopathies, were evaluated by biplane and volumetric (cardiac
short-axis stack) cine MRI and by biplane and volumetric (three-dimensional)
transthoracic echocardiography. Left ventricular volume, LVEF and LV function
categories (LVEF > or =55%, >35% to <55% and < or =35%) were then determined.
RESULTS: Biplane echocardiography underestimated LV volume with respect to the
other three strategies (p < 0.01). There were no significant differences (p >
0.05) between any of the strategies for quantitative LVEF. Volumetric MRI and
volumetric echocardiography differed by a single functional category for 2
patients (8%). Six to 11 patients (24% to 44%) differed when comparing biplane
and volumetric methods. Ten patients (40%) changed their functional status when
biplane MRI and biplane echocardiography were compared; this comparison also
revealed the greatest mean absolute difference in estimates of EF for those
subjects whose EF functional category had changed. CONCLUSIONS: Volumetric MRI
and volumetric echocardiographic measures of LV volume and LVEF agree well and
give similar results when used to stratify patients with dilated cardiomyopathy
according to systolic function. Agreement is poor between biplane and volumetric
methods and worse between biplane methods, which assigned 40% of patients to
different categories according to LVEF. The choice of imaging method (volumetric
or biplane) has a greater impact on the results than does the choice of imaging
modality (echocardiography or MRI) when measuring LV volume and systolic
function.
PMID- 10676698
TI - Contrast echocardiography clarifies uninterpretable wall motion in intensive care
unit patients.
AB - OBJECTIVES: The study examined the value of contrast echocardiography in the
assessment of left ventricular (LV) wall motion in intensive care unit (ICU)
patients. BACKGROUND: Echocardiograms done in the ICU are often suboptimal. The
most common indication is the evaluation of LV wall motion and ejection fraction
(EF). METHODS: Transthoracic echocardiograms were done in 70 unselected ICU
patients. Wall motion was evaluated on standard echocardiography (SE), harmonic
echocardiography (HE), and after intravenous (IV) contrast echocardiography (CE)
using a score for each of 16 segments. A confidence score was also given for each
segment with each technique (unable to judge; not sure; sure). The EF was
estimated visually for each technique, and a confidence score was applied to the
EF. RESULTS: Uninterpretable wall motion was present in 5.4 segments/patient on
SE, 4.4 on HE (p = 0.2), and 1.1 on CE (p < 0.0001). An average of 7.8 segments
were read with surety on SE, 9.2 on HE (p = 0.1), and 13.7 on CE (p < 0.0001).
Ejection fraction was uninterpretable in 23% on SE, 13% on HE (p = 0.14), and 0%
on CE (p = 0.002 vs. HE; p < 0.0001 vs. SE). The EF was read with surety in 56%
of patients on SE, 62% on HE (p = 0.47), and 91% on CE (p < 0.0001). Thus, wall
motion was seen with more confidence on CE. More importantly, the actual readings
of segmental wall motion and EF significantly differed using CE. CONCLUSIONS: CE
should be used in all ICU patients with suboptimal transthoracic echocardiograms.
PMID- 10676699
TI - Improving the evaluation of left ventricular systolic function with intravenous
perfluorocarbon ultrasound contrast: will suboptimal echocardiograms become an
endangered species?
PMID- 10676700
TI - Polymeric-based perivascular delivery of a nitric oxide donor inhibits intimal
thickening after balloon denudation arterial injury: role of nuclear factor
kappaB.
AB - OBJECTIVES: To examine the effect of a polymeric-based periadventitial delivery
of a nitric oxide (NO)-releasing diazeniumdiolate, spermine/NO (SPER/NO), on
balloon injury-induced neointimal hyperplasia in rat ileofemoral arteries.
BACKGROUND: Reduced local bioavailability and adverse side effects limit systemic
administration of NO to modulate vascular response to injury. METHODS: A
polylactic-polyglycolic acid polymeric matrix containing 2.5% SPER/NO (w/w) was
applied around the injured arteries. Quantitative histomorphometry was performed
at day 14, proliferating cell nuclear antigen (PCNA) immunohistochemistry at day
3 to assess effects on smooth muscle proliferation and electrophoretic mobility
shift assay to evaluate effects on transcription factor, nuclear factor-kappaB
(NF-kappaB). RESULTS: Treatment with SPER/NO reduced the intimal area (0.011 +/-
0.009 vs. 0.035 +/- 0.006 mm2 control, p < 0.01) and the intima to media ratio
(0.089 +/- 0.062 vs. 0.330 +/- 0.057 control, p < 0.005). Spermine/nitric oxide
produced a profound inhibition of PCNA-positive cells (>75%, p < 0.005) and
significantly suppressed the injury-induced activation of NF-kappaB. Vascular
cyclic guanosine monophosphate (cGMP) levels were elevated after treatment with
the SPER/NO (0.28 +/- 0.03 vs. 0.17 +/- 0.02 pmol/mg tissue control, p < 0.01).
The inhibitory effects on neointimal proliferation were localized to the site of
application of SPER/NO and were not associated with any changes in platelet
aggregation or bleeding time. Neither SPER nor polymer alone had any significant
effects on any of the variables examined. CONCLUSIONS: Polymeric-based
perivascular delivery of a NO donor produces a marked localized inhibition of
neointimal proliferation in balloon-injured arteries. This phenomenon is
associated with suppression of NF-kappaB activation and elevation of the vascular
cGMP at the site of injury.
PMID- 10676701
TI - Single-beat determination of preload recruitable stroke work relationship:
derivation and evaluation in conscious dogs.
AB - OBJECTIVES: To derive and evaluate a method of estimating the slope (Mw) of the
preload recruitable stroke work (PRSW) relationship between left ventricular
stroke work (SW) and end-diastolic volume (EDV) from a single beat. BACKGROUND:
Mw is a load-insensitive index of contractile function, but its clinical
application has been limited by the need to record multiple beats over a wide
volume range. METHODS: Pressure-volume loops were recorded over a variable
preload and afterload range by vena caval and aortic constrictions in 12
conscious dogs instrumented with epicardial dimension transducers and
micromanometers. Single-beat Mw (SBMw) was determined as the ratio SW/(EDV-Vw),
where the volume-axis intercept of the PRSW relationship (Vw)(EDV at zero SW) was
estimated as k x EDVB + (k - 1)LVwall, k is the ratio of the epicardial shell
volumes corresponding to Vw and baseline EDV (EDVB) and LVwall is wall volume.
RESULTS: In the first six dogs, k was found to be essentially constant at 0.7,
SBMw estimates were insensitive to wide preload variation, and the relationship
between SBMw and multibeat Mw determined during caval and aortic constrictions
did not differ significantly from the line of identity. When the same constant k
value was applied to SBMw estimation in a different group of six dogs, SBMw did
not differ significantly from multibeat Mw (83 +/- 12 erg x cm(-3) x 10(3) and 77
+/- 12 erg x cm(-3) x 10(3), respectively), neither changed significantly during
aortic constriction and both increased significantly with calcium infusion (107
+/- 18 erg x cm(-3) x 10(3) and 95 +/- 19 erg x cm(-3) x 10(3), respectively,
both p < 0.05). Single-beat Mw was less load-dependent, more reproducible and a
more sensitive index of inotropic state than two previously described single-beat
indexes, single-beat elastance and maximum power divided by EDV2. CONCLUSIONS: Mw
can be determined accurately from a single, steady-state beat in the normal
canine heart and is sensitive to inotropic alterations while being insensitive to
wide variations in preload and afterload. Single-beat Mw estimation should
facilitate noninvasive, load-independent assessment of contractile function.
PMID- 10676702
TI - Nicorandil, a potent cardioprotective agent, acts by opening mitochondrial ATP
dependent potassium channels.
AB - OBJECTIVES: To determine the mechanism of cardioprotection afforded by
nicorandil, an orally efficacious antianginal drug, we examined its effects on
ATP-dependent potassium (K(ATP)) channels. BACKGROUND: Nicorandil can mimic
ischemic preconditioning, while mitochondrial K(ATP) (mitoK(ATP)) channels rather
than sarcolemmal K(ATP) (surfaceK(ATP)) channels have emerged as the likely
effectors. METHODS: Flavoprotein fluorescence and membrane current in intact
rabbit ventricular myocytes were measured simultaneously to assay mitoK(ATP)
channel and surface K(ATP) channel activities, respectively. In a cell-pelleting
model of ischemia, cells permeable to trypan blue were counted as killed by 60
and 120 min of ischemia. RESULTS: Nicorandil (100 micromol/liter) increased
flavoprotein oxidation but not membrane current; a 10-fold higher concentration
recruits both mitoK(ATP) and surfaceK(ATP) channels. Pooled dose-response data
confirm that nicorandil concentrations as low as 10 micromol/liter turn on
mitoK(ATP) channels, while surfaceK(ATP) current requires exposure to millimolar
concentrations. Nicorandil blunted the rate of cell death in a pelleting model of
ischemia; this cardioprotective effect was prevented by the mitoK(ATP) channel
blocker 5-hydroxydecanoate but was unaffected by the surfaceK(ATP) channel
blocker HMR1098. CONCLUSIONS: Nicorandil exerts a direct cardioprotective effect
on heart muscle cells, an effect mediated by selective activation of mitoK(ATP)
channels.
PMID- 10676703
TI - Intracoronary basic fibroblast growth factor enhances myocardial collateral
perfusion in dogs.
AB - OBJECTIVE: In preparation for clinical trials of basic fibroblast growth factor
(bFGF) to treat ischemic heart disease, we sought to identify a clinically
feasible method of bFGF administration. BACKGROUND: Basic FGF has been shown to
promote collateral development after experimentally induced coronary occlusion;
however, methods of bFGF delivery that have been shown to be effective in
previous investigations would not be practical for clinical use. METHODS: Four
randomized, blinded, controlled investigations were conducted independently and
sequentially in an established canine model. For all studies, dogs underwent
operative placement of proximal left circumflex coronary artery ameroid
constrictors. The four investigational regimens included: 1) bFGF by central
venous bolus injection, 1,740 microg/day for one, two or seven days; 2) bFGF by
intravenous infusion, 100 microg/kg body weight per day for seven days; 3) bFGF
by pericardial instillation, 2,000 microg/day for 7 days; and 4) bFGF by
intracoronary injection (Judkin's technique), 100 microg/kg per day for one or
two days. Each substudy included a contemporaneous vehicle control group.
Collateral perfusion (microspheres) was assessed during maximal coronary
vasodilation during the first month after ameroid placement. RESULTS: Maximal
collateral perfusion in dogs that received intracoronary bFGF for two days
exceeded that of concurrent control dogs by 31% (p < 0.01). Perfusion was not
increased in dogs that received single-dose intracoronary bFGF. Basic FGF
administration by central venous bolus injection, intravenous infusion and
pericardial injection failed to enhance collateral perfusion. CONCLUSIONS:
Administration of bFGF by the intracoronary route, an intervention that is
feasible in patients, augments collateral development in dogs. These data provide
a rationale for clinical testing of intracoronary bFGF in ischemic heart disease.
PMID- 10676704
TI - Survival with full neurologic recovery and no cerebral pathology after prolonged
cardiopulmonary resuscitation with vasopressin in pigs.
AB - OBJECTIVES: We sought to determine the effects of vasopressin and saline placebo
in comparison with epinephrine on neurologic recovery and possible cerebral
pathology in an established porcine model of prolonged cardiopulmonary
resuscitation (CPR). BACKGROUND: It is unknown whether increased cerebral blood
flow during CPR with vasopressin is beneficial with regard to neurologic recovery
or detrimental owing to complications such as cerebral edema after return of
spontaneous circulation. METHODS: After 4 min of cardiac arrest, followed by 3
min of basic life support CPR, 17 animals were randomly assigned to receive every
5 min either vasopressin (0.4, 0.4 and 0.8 U/kg; n = 6), epinephrine (45, 45 and
200 microg/kg; n = 6) or saline placebo (n = 5). The mean value +/- SEM of aortic
diastolic pressure was significantly (p < 0.05) higher 90 s after each of three
vasopressin versus epinephrine versus saline placebo injections (60 +/- 3 vs. 45
+/- 3 vs. 29 +/- 2 mm Hg; 49 +/- 5 vs. 27 +/- 3 vs. 23 +/- 1 mm Hg; and 50 +/- 6
vs. 21 +/- 3 vs. 16 +/- 3 mm Hg, respectively). After 22 min of cardiac arrest,
including 18 min of CPR, defibrillation was attempted to achieve return of
spontaneous circulation. RESULTS: All the pigs that received epinephrine and
saline placebo died, whereas all pigs on vasopressin survived (p < 0.05).
Neurologic evaluation 24 h after successful resuscitation revealed only an
unsteady gait in all vasopressin-treated animals; after 96 h, magnetic resonance
imaging revealed no cerebral pathology. CONCLUSIONS: During prolonged CPR,
repeated vasopressin administration, but not epinephrine or saline placebo,
ensured long-term survival with full neurologic recovery and no cerebral
pathology in this porcine CPR model.
PMID- 10676705
TI - Heart failure awareness week: February 14-21.
PMID- 10676706
TI - President's page: back to the future: part III.
PMID- 10676707
TI - Fluorescence in situ hybridization (FISH) maps chromosomal homologies between the
dusky titi and squirrel monkey.
AB - The Platyrrhini are one of the most karyologically derived groups of primates and
the evolution of their karyotypes is far from understood. The identification of
the origin and direction of chromosome rearrangements will contribute to a better
understanding of New World monkey phylogeny, taxonomy, and evolution. We mapped
homology and identified translocations in the chromosomes of the dusky titi
monkey (Callicebus moloch, 2n = 50) and the squirrel monkey (Saimiri sciureus, 2n
= 44) by fluorescence in situ hybridization (FISH) of human chromosome paints.
The hybridization results established chromosomal homologies between these New
World primates, humans, other primates, and more distantly related mammalian
species and show that both species have highly rearranged karyotypes. The total
number of hybridization signals was 37 in C. moloch and 40 in S. sciureus, which
is in the range of most comparisons of human chromosomes with phylogenetically
more distant species outside of the primate order. Parsimony analyses of outgroup
painting patterns allowed us to propose an ancestral karyotype for New World
monkeys consisting of 2n = 56 with homologs to the following human chromosomes or
chromosome segments: 1b; 1c; 2a; 2b; 3a; 3b; 3/21; 4; 5; 6; 7; 8a; 8/18; 9; 10a;
10/16; 11; 12; 13; 14/15; 15a; 16a; 17; 19; 20; 22; X; Y. Associations 8/18 and
10/16 are derived ancestral associations for all Platyrrhini. A 2/16 association
found in S. sciureus and C. moloch was also seen in Ateles geoffroyi and Cebus
capucinus; a 5/7 association in S. sciureus was present in A. geoffroyi, C.
capucinus, and Alouatta belzebul. Other associations seen in the dusky titi
monkey or the squirrel monkey are probably automorphisms. Comparison with
chromosome phylogenies based on R-banding [Dutrillaux et al., 1986] showed that
there were many errors in assigning homology with human chromosomes. The
chromosomal phylogeny of New World monkeys based on banding patterns is in need
of revision using modern molecular methods.
PMID- 10676708
TI - When will the stork arrive? Patterns of birth seasonality in neotropical
primates.
AB - We review and discuss the ultimate and proximate causes of birth seasonality in
Neotropical primates and the seasonal patterns shown by each genus within this
group. Our review of the literature shows that most New World monkey populations
studied so far show some degree of birth seasonality. Photoperiod is the most
important proximate cue used by populations living at relatively high latitudes
to time their reproductive events, but almost nothing is known about the
proximate factors used by those near the equator. The findings are consistent
with the hypothesis that food availability is the most important ultimate cause
of birth seasonality. Predation seems to promote birth synchrony in some species
(e.g., squirrel monkeys). Multiple regression ANCOVA was used to estimate how the
degree of birth seasonality is affected by ecological and life history variables.
The ANCOVA model shows that three factors affect the degree of birth seasonality:
diet, latitude, and body size. Folivores (howlers) are less seasonal than
frugivores and insectivores. The degree of seasonality increases with latitude
and shows a humped relationship with body size, peaking at 1.66 kg body mass.
This last relationship was expected since small bodied species have to pay a cost
(in terms of time lost) by being seasonal on a yearly basis, and large species
are buffered against fluctuations in food availability due to their large body
mass. To understand which of three alternative birth strategies is followed by
each species (reduce energy stress during peak lactation, wean infants during
peak food availability, or store reserves during peak energy availability), we
compared the location of the birth peak in relation to the peak in food
availability for those populations from which data were available. Most species
conform to the typical pattern of births concentrated before the peak in food
availability, allowing peak lactation (small-sized species) or weaning
(capuchins) to take place before the start of the lean season. The pattern of
births of the atelines is consistent with the weaning hypothesis. However, since
they give birth during the lean season, this pattern is also consistent with an
alternative strategy.
PMID- 10676709
TI - Survival and reproduction in the first two years following a large-scale primate
colony move and social reorganization.
AB - (Macaca nemestrina) and baboon (Papio cynocephalus, Papio anubis, and hybrids)
breeding colonies from the Primate Field Station (PFS) (Medical Lake, WA) to the
Tulane Regional Primate Research Center (Covington, LA). Colony records on all
598 pigtailed macaques (Macaca nemestrina) and 157 baboons (P. c. anubis) shipped
to the Tulane Primate Center from the PFS breeding colony were used for analysis
of species, sex, age, origin, current status, and the number of animals born at
Tulane and their status. To provide comparative statistics, colony records on all
1,002 macaques and 258 baboons alive on 1 January 1991 at the Field Station were
retrieved in the same manner as the Tulane data. Overall survival rates of
macaques in the months following the move (71.7%) were similar to those
associated with the Arashiyama West colony move from Japan to Texas. In our
colony, significantly lower survival following the move was seen only in older
(10 years+) macaques, while survival in other age groups was slightly lower than
in the comparison year of 1991 at the Primate Field Station. Captive-bred
macaques exhibited higher survival than wild-caught animals. Infant survival at
Tulane was not significantly different than in pre-move years. Baboons fared well
in the move, with no significant differences in mortality or reproduction when
compared with the 1991 Medical Lake baboon colony.
PMID- 10676710
TI - Diurnal primate densities and biomass in the Kakamega Forest: an evaluation of
census methods and a comparison with other forests.
AB - Line-transect surveys were conducted at the Isecheno study site in the Kakamega
Forest, western Kenya to estimate diurnal primate densities. The estimates from
several different methods of analysis of census data were compared to "true"
density values based on home range size and overlap for two species. The
Whitesides method [Whitesides et al., 1988], which incorporates species-specific
mean group spread into its formula for estimating transect width, provided the
most accurate density estimates. The importance of including as many groups as
possible when calculating density from home range size and overlap is
demonstrated with long-term data from Colobus guereza and Cercopithecus mitis.
Colobus guereza group density at Isecheno was much lower than that published from
a recent brief study [von Hippel, 1996]. Cercopithecus mitis group density has
fallen while overall population biomass appears to have remained stable over 20
years of study. Isecheno has the second highest diurnal primate biomass of the
ten Guineo-Congolian rainforest sites for which biomass data are available,
despite having the lowest primate species richness. Within the Guineo-Congolian
rainforest system, primate biomass appears to vary to some extent between
ecogeographic regions: two of three mid-elevation East African sites have high
biomasses, two of two lowland West African sites have intermediate biomasses, and
four of five lowland Central African sites have low biomasses. There is a strong
positive correlation between total colobine biomass and total primate biomass at
the ten Guineo-Congolian rainforest sites.
PMID- 10676711
TI - Infanticide in a group of wild saddle-back tamarins, Saguinus fuscicollis.
AB - An infanticide was observed in a group of wild saddle-back tamarins, Saguinus
fuscicollis. The newborn singleton was killed by its mother after it had fallen
from the carrier several times. This infanticide may represent a case of parental
manipulation: the mother terminated investment in an offspring that probably had
a low chance of survival. Also, stress associated with the simultaneous pregnancy
of another adult female in the group may have played a role.
PMID- 10676712
TI - Reconciliation in captive Guyanese squirrel monkeys (Saimiri sciureus).
AB - The tendency for agonistic interaction to increase the probability of friendly
interaction between social partners has been demonstrated across a range of Old
World primates. While research on such post-conflict behavior proceeds into an
hypothesis-testing phase, new comparative information must accumulate to provide
full phylogenetic perspective on primate social behavior. Data from New World and
prosimian primates are yet extremely limited. We studied captive squirrel monkeys
(Saimiri sciureus) via post-conflict (PC) and matched control (MC) observations
and analyzed results using both the PC-MC and time-rule methods. Former opponents
maintaining affiliative relationships soon engaged in friendly interaction
following large proportions of agonistic interactions, whereas non-affiliated
individuals, including virtually all male-female pairs, reconciled conflicts
rarely. Close-proximity approaching and huddling contact constituted the
principal modes of post-conflict amicability. Agonistic interactions of
relatively high intensity were most likely to be reconciled and most likely to be
reconciled via physical contact. High vulnerability of Saimiri to predation may
have favored this species' strong inclination to reconcile soon after agonistic
interaction. Research on free-living populations of this and other primate
species is needed to illuminate similarities and differences across taxa.
PMID- 10676713
TI - Beyond "adequate dialysis".
PMID- 10676714
TI - The role of angiotensin II and plasminogen activator inhibitor-1 in progressive
glomerulosclerosis.
AB - Regardless of the primary cause, progressive renal deterioration with sclerosis
is a hallmark of many renal diseases. Several studies have shown the superiority
of angiotensin-converting enzyme inhibitors compared with other antihypertensive
agents in providing protection from progressive renal deterioration. Furthermore,
animal studies have shown that angiotensin II antagonists in excess of
antihypertensive doses can also ameliorate or reverse glomerulosclerosis, leading
to the hypothesis that angiotensin II has nonhemodynamic effects that mediate the
renoprotective effects shown in these investigations. Although historically
angiotensin II has been associated with salt and fluid homeostasis, recent data
show that angiotensin II induces cell growth and matrix accumulation in
glomerular cells. Plasminogen activator inhibitor-1 has been shown to be the
major inhibitor of tissue plasminogen activator and urokinase-like plasminogen
activator, with potentially important effects not only on
thrombosis/fibrinolysis, but also on matrix degradation because of the
proteolytic actions of these substances. Angiotensin II has been shown to
influence the actions of plasminogen activator inhibitor-1 and, consequently, its
thrombotic and sclerotic effects. Various studies, both in vitro and in vivo,
have shown that direct hemodynamic actions, modulation of endothelial injury, and
growth factor actions also may be important in the development of sclerosis.
These factors can be directly modulated by angiotensin II inhibition. Sclerosis
may even be reversed when therapies augment matrix degradation processes, both by
directly increasing proteolytic activity and by downregulating inhibitors of
matrix degradation. These observations indicate that angiotensin II is important
in fibrotic as well as thrombotic renal injuries that lead to progressive renal
disease and also in the development of therapies such as specific angiotensin
receptor antagonists to prevent or reverse these conditions.
PMID- 10676715
TI - Fatal outcome after ingestion of star fruit (Averrhoa carambola) in uremic
patients.
AB - Clinical outcome of dialysis patients after eating star fruit (Averrhoa
carambola) varies, but it may be fatal. In the past 10 years, 20 such patients
were treated in our hospital when they developed clinical symptoms after eating
the fruit or drinking star fruit juice. Their initial presentations included
sudden-onset limb numbness, muscle weakness, intractable hiccups, consciousness
disturbance of various degrees, and seizure. No other major events that might be
responsible for these symptoms could be identified. Eight patients died,
including one patient with a serum creatinine level of 6.4 mg/dL who had not yet
begun dialysis. The clinical manifestations of the survivors were similar to
those who died except for consciousness disturbance and seizure. Death occurred
within 5 days despite emergent hemodialysis and intensive medical care. The
survivors' symptoms usually became less severe after supportive treatment, and
these patients subsequently recovered without obvious sequelae. The purpose of
this article is to report that patients with renal failure who ingest star fruit
may develop neurological symptoms and also run the risk for death in severe
cases. Mortality may also occur in patients with chronic renal failure not yet
undergoing dialysis.
PMID- 10676716
TI - Early treatment with corticosteroids ameliorates proteinuria, proliferative
lesions, and mesangial phenotypic modulation in adult diffuse proliferative IgA
nephropathy.
AB - Diffuse proliferative immunoglobulin A (IgA) nephropathy has the potential risk
for end-stage renal disease. However, treatment of IgA nephropathy has not been
well established. To determine whether early treatment with corticosteroids
ameliorates the proliferative lesions of diffuse proliferative IgA nephropathy,
we conducted a prospective, randomized, controlled trial. Inclusion criteria were
as follows: duration of abnormal urinalysis results less than 36 months,
proteinuria less than 1.5 g/d of protein, serum creatinine level less than 1.5
mg/dL, and mesangial cell proliferation or matrix accumulation involving more
than 50% of glomeruli. Twenty-one patients were randomly assigned to two groups:
the corticosteroid group and the antiplatelet group. After 1 year of treatment,
repeated renal biopsy was performed in 19 patients. We evaluated glomerular
filtration rate, blood pressure, proteinuria, and histological parameters,
including light microscopic findings and staining of alpha-smooth muscle actin
(alphaSMA), as a marker of myofibroblast-like cells and fibronectin EDA (EDA-FN)
as an indicator of renal fibrosis. After 1 year of treatment, proteinuria
significantly decreased in the corticosteroid group. Histological findings, such
as mesangial cell proliferation, mesangial matrix accumulation, and cellular
crescents, showed significant improvement in the corticosteroid group but not in
the antiplatelet group. Expression of alphaSMA in glomeruli significantly
decreased in the corticosteroid group but not in the antiplatelet group. EDA-FN
did not change in either group. We conclude that early treatment with
corticosteroids for adult diffuse proliferative IgA nephropathy is effective in
reducing renal injury.
PMID- 10676717
TI - ACE inhibition delays development of terminal renal failure in the presence of
severe albuminuria.
AB - The hypertensive fawn-hooded (FHH) rat develops progressive albuminuria (UalbV)
and focal glomerulosclerosis (FGS). Early-onset angiotensin-converting enzyme
inhibition (ACE-i) completely prevented the development of hypertension, UalbV,
and FGS. ACE-i was still effective when the start of treatment was delayed,
albeit less than early-onset treatment. In this study, we examined whether more
advanced renal damage reduces the efficacy of ACE-i, and, if so, which factors
dampen the efficacy. ACE-i was started in 36-week-old FHH rats, and follow-up
consisted of regular assessment of systolic blood pressure (SBP) and UalbV.
Untreated rats, matched for age, SBP, and UalbV, served as controls. In separate
groups, untreated or treated with ACE-i from either week 7 or week 36, glomerular
hemodynamics and FGS were determined at week 40. ACE-i normalized SBP and
markedly reduced UalbV. The Initial UalbV response to ACE-i was inversely
correlated with pretreatment UalbV, but despite control of SBP, UalbV rose again.
Eventually, rats died of terminal renal failure. Life expectancy was
significantly increased in treated rats. In both untreated and treated rats,
there was a significant inverse correlation between baseline UalbV and survival
time. However, the gain in survival time decreased when pretreatment UalbV was
higher. Late-onset ACE-i reduced glomerular capillary pressure to the same extent
as early-onset ACE-i. There was a significant linear correlation between FGS and
UalbV. We conclude that in FHH rats with advanced renal damage, ACE-i slows down
the progression to terminal renal failure. The outcome is an increased survival
time that is inversely correlated with baseline UalbV.
PMID- 10676718
TI - ACE gene polymorphism and survival in atherosclerotic renovascular disease.
AB - Renovascular disease (RVD) is an important cause of end-stage renal disease and
is associated with a high mortality rate, mostly because of coexisting
cardiovascular and cerebrovascular disease. The deletion (DD) polymorphism of the
angiotensin-converting enzyme (ACE) gene has been described in association with
severe vascular disease affecting major organs. To investigate whether DD
genotype is a risk factor for mortality in RVD, we performed a follow-up study of
61 patients with this disease. Patients (age, 68.0 +/- 6.5 years) affected by
atherosclerotic vascular disease were enrolled after angiographic demonstration
of a renal artery stenosis. The average follow-up was 48.1 +/- 14.9 months.
Genotype was insertion/deletion (I/D) in 30 patients, DD in 27 patients, and II
in 4 patients. At enrollment, a complete assessment of heart, blood vessels, and
renal function was performed. During the follow-up period, 13 patients died (9
DD, 4 ID) and 7 patients evolved into end-stage renal failure. The cumulative
survival rate at 5 years was 45.4% +/- 13.4%. Factors associated with mortality
were analyzed with Cox proportional hazard regression. The multivariate analysis
showed that DD genotype, severe carotid disease, and smoking were independent
predictors of mortality. The multivariate analysis of predictors of renal failure
showed that the only significant association was found with baseline serum
creatinine level of 265 micromol/L or greater. We conclude that the DD genotype
of the ACE gene is a marker for mortality in RVD.
PMID- 10676719
TI - Digital glomerular reconstruction in a patient with a sporadic adult form of
glomerulocystic kidney disease.
AB - This study describes a sporadic adult form of glomerulocystic kidney disease in a
52-year-old man. To determine whether the aperture of the proximal tubule was
stenosed or obstructed to clarify the pathogenesis of glomerular cyst
development, 100 serial sections of the open biopsy specimen were made. Ten
glomerular cysts were reconstructed using three-dimensional imaging analysis.
Bowman's capsule (glomerular cyst) volume, the volume of glomerular tufts, and
the area of the proximal tubular opening were estimated using imaging analysis.
The volumes of Bowman's capsule and of glomerular tufts were 0.0098 +/- 0.0039
mm3 (mean +/- SD) (normal: 0.0041 to 0.0083 mm3) and 0.0026 +/- 0.0013 mm3,
respectively. The area of the proximal tubular opening was 0.0017 +/- 0.0003 mm2
(normal: 0.0012 to 0.0028 mm2). There was neither obstruction nor stenosis of the
opening of the renal tubule in this sporadic adult form of glomerulocystic kidney
disease. After 4 years of hemodialysis, the glomerular cysts, as well as the
kidneys, enlarged. This study shows that the main cause of glomerular cyst
development is not glomerulotubular neck obstruction.
PMID- 10676720
TI - Effect of probucol in a murine model of slowly progressive polycystic kidney
disease.
AB - Epithelial proliferation, extracellular matrix remodeling, and interstitial
inflammation are central elements in the pathogenesis of slowly progressive
polycystic kidney disorders. Probucol, an antioxidant that lowers plasma
cholesterol, has been shown to decrease smooth muscle cell proliferation and
macrophage accumulation in blood vessels and to prevent restenosis after coronary
angioplasty. We determined in 30-day-old male BDF1-pcy hybrid mice (derived from
mating DBA/2FG-pcy and C57BL/6FG-pcy) the effect of probucol administered in the
diet (1%) for 200 days on kidney weight relative to body weight (KW/BW), cyst
expansion, renal interstitial fibrosis, and serum urea nitrogen (SUN)
concentration. Animals were fed a moderately high-protein diet (HPD, 36%) to
accentuate the development of renal cysts and to promote interstitial fibrosis.
Probucol decreased serum cholesterol from 68 to 16 mg/dL but had no effect on
food intake or body weight. Probucol decreased relative kidney size from 4.16% +/
0.55% to 2.64% +/- 0.12% KW/BW (P < 0.01), SUN from 30.5 +/- 1.8 to 25.9 +/- 1.0
mg/dL (P < 0.05), cystic index from 2.45 +/- 0.11 to 1.36 +/- 0.10 (P < 0.01),
and fibrosis index from 2.40 +/- 0.11 to 1.82 +/- 0.08 (P < 0.01). We conclude
that probucol ameliorates the progressive deterioration in renal function and
structure in pcy mice ingesting a relatively high level of dietary protein.
PMID- 10676721
TI - Effect of 1,25-dihydroxyvitamin D3 and calcium carbonate on bone loss associated
with long-term renal transplantation.
AB - To investigate the effect of calcitriol plus calcium carbonate on the bone loss
associated with long-term renal transplantation, 30 patients with serum
creatinine levels less than 2.0 mg/dL were randomly allocated to a control (n =
14) or treatment group (n = 16) and studied with bone biopsy and densitometry at
baseline and after 1 year of follow-up. Calcitriol (0.25 microg/d) plus calcium
carbonate (500 mg/d of elemental calcium) were administered to patients in the
treatment group. Comparing the baseline and final data of each group at a time,
no change in bone mineral density (BMD) z score was observed at the distal radius
(control, -0.8 +/- 0.8 versus -0.6 +/- 0.9; treatment, -1.0 +/- 1.0 versus -1.0
+/- 1.1). However, a significant increase (P < 0.05) was found at the lumbar
spine in both groups (control, 0.1 +/- 1.6 versus 0.4 +/- 1.6; treatment, -0.1 +/
1.5 versus 0.3 +/- 1.5) and only in the treatment group at the femoral neck
(control, -0.9 +/- 1.0 versus -0.8 +/- 1.0; treatment, -0.5 +/- 0.9 versus -0.3
+/- 1.1). When BMD was compared between groups, no significant differences were
observed at the evaluated anatomic sites at baseline or after 1 year of follow
up. After 1 year of follow-up, adjusting for age and sex (z score), the control
group showed a trend to reduce the value of several histomorphometric parameters,
including osteoblast surface (-2.2 +/- 6.1 versus -3.4 +/- 3.9), osteoid surface
(-2.3 +/- 3.5 versus -3.1 +/- 3.9), and osteoclast surface (0.2 +/- 5.0 versus
1.3 +/- 3.3). Consequently, there was a significant reduction (P < 0.05) in
mineralizing surface (-9.8 +/- 11.0 versus -15.8 +/- 12.3) and appositional rate
(-5.8 +/- 2.7 versus -7.6 +/- 2.2). In the treatment group, a significant
reduction (P < 0.05) in osteoclast surface was observed at the end of the study
(3.9 +/- 6.8 versus -1.2 +/- 4.1), and although a trend to reduce osteoblast
surface (-2.5 +/- 2.6 versus -3.2 +/- 5.7) and osteoid surface (-2.1 +/- 2.5
versus -3.2 +/- 2.8) was also found, patients maintained approximately the same
level of wall thickness (-5.2 +/- 5.3 versus -5.3 +/- 3.3) and bone volume (-2.7
+/- 1.8 versus -2.5 +/- 1.7). However, there was no improvement in mineralizing
surface (-4.2 +/- 2.9 versus -10.4 +/- 3.6) or appositional rate (-5.8 +/- 3.1
versus -8.1 +/- 2.6). No significant differences in bone histomorphometric
variables were observed between groups after 1 year of follow-up. In conclusion,
1,25-dihydroxyvitamin D3 and calcium carbonate did not significantly improve bone
loss in long-term renal transplant recipients. However, significant osteoclast
suppression and a trend to maintain trabecular bone volume and wall thickness as
well as improve the axial BMD were observed in the treatment group.
PMID- 10676722
TI - Life expectancy benefits of cancer screening in the end-stage renal disease
population.
AB - Health maintenance includes secondary prevention through cancer screening. There
are no established guidelines for cancer screening patients with end-stage renal
disease (ESRD). Using an established method of estimating life expectancy,
published literature on cancer screening, and information from databases on
mortality and malignancy (US Renal Data System 1997 Annual Data Report and the
SEER Cancer and Statistical Review, 1973-1994), a "real-time life expectancy
calculator" was developed to guide the primary help provider in making informed
decisions on the benefits of cancer screening in individual patients. Potential
days of life saved by each screening method can be calculated using the
difference in life expectancy per the DEALE (declining exponential approximation
of life expectancy) method with and without cancer screening. Using two sets of
assumptions (one to enhance any bias toward support for screening and one to
limit this bias), a range of potential days of life saved with screening for
breast and colon cancer can be calculated in individual patients with ESRD. In
breast cancer, for example, a 50-year-old black woman with ESRD and multiple risk
factors would have 41 to 291 potential days of life saved with screening. A 60
year-old white woman with ESRD and diabetes mellitus (DM) would have only 1 to 16
days of life saved. This life expectancy calculator can guide the primary health
care provider in making clinical decisions concerning screening in the ESRD
population. In addition to assisting in patient education, the calculator can be
updated as new information becomes available regarding relative risk, treatment,
and mortality.
PMID- 10676723
TI - Impact of disease severity and hematocrit level on reuse-associated mortality.
AB - Prior studies on reuse-associated mortality have presented conflicting results
and included few adjustments for disease severity or hematocrit levels. To
evaluate the impact of patient and provider characteristics on reuse-associated
mortality, we developed a period-prevalent model with a 6-month entry period.
Five cohorts of Medicare hemodialysis patients surviving from July 1 through
December 31 of the entry year (1991, 60,985 patients; 1992, 63,081 patients;
1993, 76,018 patients; 1994, 82,899 patients; 1995, 91,761 patients) were
followed up for the next year. Using a basic Cox regression survival model (M-1)
including age, sex, race, renal diagnosis, prior end-stage renal disease time,
unit age, unit size, water treatment, dialysate, and germicide, results were
compared with those using a more inclusive model (M-4) adding dialyzer type
(conventional or high efficiency/high flux), unit designation (hospital based or
freestanding), unit profit status, comorbidity, disease severity, and hematocrit.
The previous association of for-profit units with increased mortality was not
present after 1994. Whereas the M-1 analysis showed better survival in reuse
units after 1991, the more complete M-4 analysis showed no difference in the risk
for mortality between reuse and no-reuse units. We conclude that mortality rates
in the United States from 1991 to 1995, when adjusted comprehensively for patient
and unit characteristics, were not different in units that practiced reuse and
those that did not.
PMID- 10676724
TI - Cardiovascular effect of normalizing the hematocrit level during erythropoietin
therapy in predialysis patients with chronic renal failure.
AB - The optimal target hematocrit (Ht) level in recombinant human erythropoietin
(rHuEPO) therapy remains controversial and has hardly been investigated in
predialysis patients. We prospectively studied the regression of left ventricular
hypertrophy (LVH) on echocardiography in nine predialysis patients with chronic
renal failure after a partial correction (target Ht, 30%) and normalization
(target Ht, 40%) of the Ht with rHuEPO treatment. Twenty-four-hour ambulatory
blood pressure monitoring was also performed. The administration of rHuEPO
significantly increased Ht to the target values. The rate of renal failure
progression did not change during rHuEPO treatment for 12 months (Cr, from 6.2 +/
2.0 to 5.5 +/- 2.1 mg/dL). The left ventricular mass index (LVMI) tended to
decrease after a partial correction of anemia (Ht, 32.1% +/- 1.8%) at 4 months,
whereas it tended to significantly decrease after normalization of Ht (Ht, 39.1%
+/- 2.4%) at 12 months (baseline, 140.6 +/- 12.1 g/m2; partial correction, 126.9
+/- 10.0 g/m2; normalization, 111.2 +/- 8.3 g/m2). All patients had received
antihypertensive medication before rHuEPO administration, and additional drugs
were also required in four cases during the study. As a result, a good overall
blood pressure control was obtained without any adverse effects on the circadian
blood pressure rhythm. In conclusion, from the perspective of LVH regression, the
normalization of Ht was found to be more effective than that associated with a
partial correction of anemia during rHuEPO therapy.
PMID- 10676725
TI - Interdialytic weight gain, compliance with dialysis regimen, and age are
independent predictors of blood pressure in hemodialysis patients.
AB - Hypertension is a common problem in patients undergoing chronic hemodialysis. The
purpose of this study is to identify the clinical and demographic factors
independently associated with blood pressure in this population. Data collected
for the Dialysis Morbidity and Mortality Study Wave 1 by the US Renal Data System
were analyzed. The mean predialysis blood pressure for this cohort of 5,369
patients was 149/79 mm Hg. Sixty-three percent of the patients were hypertensive;
27%, 25%, and 11% had stages 1, 2, and 3 hypertension, respectively. Young age,
black race, male sex, diabetes as cause of end-stage renal disease,
erythropoietin therapy, and smoking were associated with higher blood pressure in
the univariate analysis. Patients skipping or shortening one or more dialysis
treatments had higher blood pressure. The presence of congestive heart failure
and coronary heart disease was associated with lower blood pressure. On
multivariate analysis, high interdialytic weight gain, noncompliance with
dialysis regimen, and younger age were independent predictors of higher blood
pressure. In summary, hypertension is common and poorly controlled in patients
undergoing chronic hemodialysis. Greater interdialytic weight gain and
noncompliance with dialysis regimen are independently associated with higher
blood pressure, and advancing age is associated with lower blood pressure levels
in this population. Therapeutic regimens emphasizing reduction of interdialytic
weight gain and improved compliance with the dialysis regimen need to be
evaluated for improving the management of hypertension. The effect of age and
other comorbid conditions, particularly cardiovascular disease, must be
considered while studying the relationship between blood pressure and mortality
in patients undergoing chronic hemodialysis.
PMID- 10676726
TI - Improved urea reduction ratio and Kt/V in large hemodialysis patients using two
dialyzers in parallel.
AB - Delivered dose of hemodialysis (HD) in large patients with end-stage renal
disease is often less than adequate. Fourteen chronic HD patients with weights
greater than 80 kg participated in a prospective, cross-over study comparing urea
reduction ratio (URR +/- SEM) and the fractional clearance index for urea
(eKt/V(urea) +/- SEM) on a single polysulfone dialyzer for a control (HDC) period
of 4 weeks versus clearances obtained with two dialyzers in parallel during an
intervention (HDP) period of 4 weeks. Clearance of the surrogate middle molecule
iohexol (C(Io)) was also measured. Health status was assessed with the SF-36.
Blood and dialysate flow rates and duration of HD sessions were constant. URR
increased from 0.67 +/- 0.006 during HDC to 0.72 +/- 0.006 with HDP (P < 0.0001).
eKt/V(urea) increased from 1.16 +/- 0.021 to 1.34 +/- 0.021 (P < 0.0001).
Increased URR and eKt/V(urea) occurred in all 14 during HDP (P < 0.05). C(Io)
during HDP averaged 182 +/- 7.7 mL/min compared with 131 +/- 5.4 mL/min in HDC
sessions (P < 0.00001). Health status improved in six of eight categories.
Expense increased approximately $14.27 per dialysis with HDP. In 11 of 14
patients continued on two dialyzers in parallel for 1 year, monthly eKt/V
averaged 1.46 +/- 0.066, and health status further improved in five of eight
categories. In large patients, two dialyzers in parallel increased urea and
iohexol clearance. Increased urea clearance was maintained for 1 year, and health
status improved.
PMID- 10676727
TI - Use of standardized ratios to examine variability in hemodialysis vascular access
across facilities. Medical Review Board of The Renal Network, Inc.
AB - The type of hemodialysis vascular access (catheter, fistula, graft) is an
important determinant of patient morbidity and dialysis efficiency. The relative
importance of patient versus provider factors in determining type of vascular
access is unclear. We sought to develop a quality improvement tool that adjusts
for differences in patient characteristics, thereby allowing examination of
provider-related variability in types of vascular access used across facilities.
We examined 15,339 patients from 216 chronic hemodialysis units in Indiana,
Kentucky, Ohio, and Illinois and found that 20% of patients had catheters, 24%
had fistulas, and 56% had grafts. Young, male, and white patients were more
likely to have fistulas, whereas old, female, and black patients were more likely
to have grafts. Diabetics were more likely to have catheters and less likely to
have fistulas. New patients were more likely to have catheters and less likely to
have grafts. A facility specific standardized catheter ratio (SCR), standardized
fistula ratio (SFR), and standardized graft ratio (SGR) were calculated based on
the actual number of patients with each type of vascular access divided by the
expected number adjusted for patient characteristics. Facility SCRs ranged from
0.00 to 2.87. Of the 216 facilities, 38 (18%) had an SCR significantly less than
1.00, and 32 (15%) had an SCR significantly greater than 1.00. Similar
variability was observed in SFRs and SGRs. In conclusion, the type of vascular
access varies greatly across facilities. Use of standardized access ratios
adjusted for patient characteristics may help providers examine processes of care
that contribute to variability in access use. Analogous to the standardized
mortality ratio, the SCR, SFR, and SGR should be effective quality improvement
tools.
PMID- 10676728
TI - Septicemia in diabetic hemodialysis patients: comparison of incidence, risk
factors, and mortality with nondiabetic hemodialysis patients.
AB - Diabetes mellitus is the most common cause of treated end-stage renal disease
(ESRD), and diabetic hemodialysis patients have a high mortality rate. To
identify differences in risk of septicemia among diabetic and nondiabetic
hemodialysis patients, we examined the incidence, risk factors, and mortality for
septicemia in a large sample of the US hemodialysis population. We performed a
longitudinal cohort study of the incidence and risk factors for hospitalized
cases of septicemia in diabetic and nondiabetic hemodialysis patients using
baseline data from the US Renal Data System case-mix severity study with 7-year
follow-up from hospitalization and death records. Independent risk factors for
septicemia were assessed using Poisson regression. Independent effect of
septicemia on mortality was assessed using Cox proportional hazards analysis.
Over 7 years, 11.1% of nondiabetic patients and 12.5% of diabetic patients
experienced at least one episode of septicemia. Older age and low serum albumin
were independent risk factors for septicemia in all patients. In diabetics, white
race, peripheral vascular disease, and hemodialyzer reuse, particularly in type
1, were independent risk factors. In nondiabetics, coronary artery disease,
cerebrovascular disease, and temporary and permanent catheters were associated
with an increased risk. In both groups, patients who experienced an episode of
septicemia had twice the risk of death from any cause and an eightfold risk of
death from septicemia. Septicemia occurs equally frequently and carries a marked
increased risk of death in both nondiabetic and diabetic hemodialysis patients.
Improving nutritional status and minimizing the use of catheters might help
ameliorate the risk of septicemia. In diabetics, aggressive treatment of
peripheral vascular disease might help reduce the risk of septicemia. Further
research to elucidate potential mechanisms for variations in risk for septicemia
according to race and hemodialyzer reuse practices are warranted in diabetic
patients.
PMID- 10676729
TI - Quality-of-life evaluation using Short Form 36: comparison in hemodialysis and
peritoneal dialysis patients.
AB - Short Form 36 (SF-36) is a well-documented health-related quality-of-life (HRQOL)
instrument consisting of 36 questions compressed into eight scales and two
primary dimensions: the physical and mental component scores. This tool was used
to evaluate QOL among peritoneal dialysis (PD) and hemodialysis (HD) patients.
The results of 16,755 HD and 1,260 PD patients (728 continuous ambulatory PD
[CAPD] and 532 continuous cycling PD [CCPD]) completing an SF-36 during 1996 were
analyzed. Three analyses of variance were performed, consisting of (1) no
adjustment, (2) case mix (age, sex, race, and diabetes), and (3) case mix plus
laboratory parameters. PD patients were younger (P < 0.001), a larger fraction
were white (P < 0.001), fewer had diabetes (P < 0.001), and had lower serum
albumin concentrations (P < 0.001) and higher creatinine, hemoglobin, and white
blood cell count values (P < 0.001) than HD patients. Diabetes was present in a
larger fraction of CCPD than CAPD patients (P < 0.001). HD and PD patients scored
similarly for scales reflecting physical processes. PD patients scored higher for
mental processes, but only after statistical adjustment for the laboratory
measures. Scores on scales reflecting physical processes were worse, and those
reflecting mental processes were better among CCPD than CAPD patients. HD and
CAPD scores were similar. CCPD patients perceived themselves as more physically
impaired but better adjusted than HD or CAPD patients. These descriptive data
show that perception of QOL among PD and HD patients is similar before
adjustment, but PD patients score higher for mental processes with adjustment.
CCPD patients score worse for physical function and better for mental function
than either CAPD or HD patients. We cannot, however, exclude the influence of
therapy selection.
PMID- 10676730
TI - Role of Fogarty catheter manipulation in management of migrated, nonfunctional
peritoneal dialysis catheters.
AB - Peritoneal dialysis (PD) catheter migration to the upper abdomen is not an
uncommon cause of catheter failure. We prospectively examined the role of the
Fogarty catheter manipulation technique to reposition the PD catheter in the
pelvis and regain patency. All patients with PD catheter malfunction caused by
migration, confirmed by abdominal radiograph, underwent the same protocol. The
patient was placed flat on the back, and the Fogarty was advanced into the PD
catheter to a premarked point at which the end of the Fogarty was near the end of
the PD catheter. The Fogarty balloon was inflated with 0.5 mL of sterile saline,
and manipulation was performed by tugging movements until proper placement of the
PD catheter into the pelvis was suspected. Infusion and drainage of dialysate was
performed to determine patency. The return of the PD catheter into the pelvis was
then confirmed by repeated radiograph. Success rates of Fogarty catheter
manipulation, early and late recurrence (remigration < or =90 days or >90 days),
and complications were prospectively examined in 232 patients over a 6-year
period. Catheter migration occurred in 34 of 232 patients (15% incidence). All
patients had curled-end, double-cuffed, non-swan-neck PD catheters. Successful
repositioning occurred in 24 of 34 patients (71%). None of the 24 repositioned
catheters had early recurrence, and 1 of 24 catheters (4%) had late recurrence.
None of the patients had procedure-related peritonitis, bowel perforation, or
exit-site trauma. These results show that PD catheter migration is relatively
common (15%). The Fogarty manipulation technique is a simple, cost-effective way
to prolong PD catheter life and preserve its long-term patency. This eliminates
the need for surgical intervention in approximately 70% of patients with PD
catheter migration.
PMID- 10676731
TI - Mouse to elephant: biological scaling and Kt/V.
AB - The construct Kt/V is used by the nephrology community in prescribing dialysis
dose. The concerns that have been raised as to what value of V to use in the
calculation of Kt/V touch on the more central question of whether filtration rate
should be normalized by a parameter other than V. Within the animal kingdom, a
number of physiological variables scale to body size according to an equation of
the form Y = YoMb, where Yo is a constant, M is body mass, and b is a scaling
exponent. Glomerular filtration rate (GFR) in mammals weighing from 30 g to 503
kg scales to body weight with an exponent of 0.77. Hence, GFR per unit body
weight (or Kt/V) decreases significantly with increasing body size. Metabolic
rate also scales to body size in a wide range of mammals according to the same
general equation and with a scaling exponent of 0.75. Because GFR and metabolic
rate scale to body mass with virtually the same exponent, a ratio of the two
yields a constant independent of body size. We propose that the ratio (filtration
rate/metabolic rate) replace Kt/V. Such a ratio would underscore the linkage
between filtration rate (and dialysis therapy) and the metabolic demands of the
body.
PMID- 10676732
TI - Noni juice (Morinda citrifolia): hidden potential for hyperkalemia?
AB - We report the case of a man with chronic renal insufficiency who self-medicated
with an alternative medicine product known as noni juice (Morinda citrifolia).
The patient presented to the clinic with hyperkalemia despite claiming adherence
to a low-potassium diet. The potassium concentration in noni juice samples was
determined and found to be 56.3 mEq/L, similar to that in orange juice and tomato
juice. Herbal remedies and alternative medicine products may be surreptitious
sources of potassium in patients with renal disease.
PMID- 10676733
TI - Rapidly progressive fibrosing interstitial nephritis associated with Chinese
herbal drugs.
AB - Rapidly progressive fibrosing interstitial nephritis after a slimming regimen
containing aristolochic acid has been identified as Chinese herbs nephropathy
(CHNP). From 1995 to 1998, we observed 12 Chinese people from different areas of
Taiwan who underwent renal biopsy for unexplained renal failure. Medical history
gave no clue to the causes of impaired renal function except for the ingestion of
traditional Chinese herbs. Although these patients ingested herbal drugs from
various sources for different purposes, their renal biopsy samples showed
amazingly similar histological findings, with extensive hypocellular interstitial
fibrosis and atrophy and loss of tubules in all cases. Glomeruli were apparently
intact. They also had similar clinical features, such as normal or mildly
elevated blood pressure, early and severe anemia, low-grade proteinuria,
glycosuria, and insignificant urinary sediments. Renal function deteriorated
rapidly in most patients despite discontinuation of the herbal medicines. Seven
patients underwent dialysis, and the remainder experienced slowly progressive
renal failure. Bladder carcinoma was found in one patient. Morphologically and
clinically, the nephropathy in our patients was similar to CHNP, reported in
Belgium. Because of the complexity and unknown types of herbs used in different
clinical situations, unidentified phytotoxins other than aristolochic acid might
be responsible for this unique disease entity. We conclude that the relation of
this nephropathy to the consumption of Chinese herbs is striking. Using
uncontrolled herbal remedies carries a high risk for developing interstitial
renal fibrosis and urothelial malignancy.
PMID- 10676734
TI - Cardiopulmonary manifestations of Henoch-Schonlein purpura.
AB - Henoch-Schonlein purpura (HSP) is usually a mild condition involving the skin,
gut, joints, and kidneys and has a good prognosis. We present a 63-year-old
Hispanic man who had an unusually severe form of HSP with a fatal outcome
attributable to vasculitis causing myocardial necrosis. There is only one
citation in the literature of HSP-related myocardial vasculitis, which involved
the right ventricle and was successfully treated with steroids. Our patient had
severe HSP-related myocardial necrosis, tracheobronchitis, and nephritis. The
bronchial lesions resolved, presumably because of steroid therapy. This probably
is the first case of fatal myocardial necrosis related to HSP. We conclude that
HSP can, in some cases, have an aggressive course. It becomes imperative to
recognize the involvement of the other organ systems, such as the heart, so that
appropriate therapy may be initiated. Immunosuppression may have a beneficial
effect on extrarenal lesions. Controlled clinical trials are needed to establish
the efficacy of such treatment.
PMID- 10676735
TI - Charcoal hemoperfusion in the treatment of phenytoin overdose.
AB - In the case of phenytoin, a drug that is generally highly protein bound, there is
a lack of consensus on the use of charcoal hemoperfusion in cases of overdose. We
performed charcoal hemoperfusion on a phenytoin-overdosed patient to assess the
effectiveness of this treatment. The plasma concentrations of total and free
phenytoin fell rapidly, from 40.0 microg/mL and 3.6 microg/mL to 16.2 microg/mL
and 1.5 microg/mL, respectively, after 3 hours of hemoperfusion. The total
phenytoin elimination half-life was 3.9 hours. The fraction of protein-bound
phenytoin was constant (90.8% +/- 0.5%) before, during, and after the procedure.
The relations between the in vitro protein binding and adsorption of phenytoin to
activated charcoal were also examined. Interestingly, bound phenytoin was found
to dissociate from plasma proteins in the presence of activated charcoal and
subsequently became adsorbed to the activated charcoal. Considering that
phenytoin is bound to albumin with a large number of binding sites (n = 6) and a
small binding constant (K = 6 x 10(3/)mol/L), the extent of adsorption to
activated charcoal may depend on the magnitude of the binding constant of the
drug to plasma proteins. The current results suggest that charcoal hemoperfusion
is effective for the removal of drugs that bind to plasma proteins with a low
binding constant.
PMID- 10676736
TI - The failure of breast cancer screening.
PMID- 10676737
TI - Nephropathy and herbal medicine.
PMID- 10676738
TI - Nephrotoxicity of immunosuppressive drugs: long-term consequences and challenges
for the future.
AB - The calcineurin inhibitors cyclosporin A (CsA) and tacrolimus (FK506) are
associated with dose- and efficacy-limiting adverse events, including
nephrotoxicity, which may diminish their overall benefits for long-term graft
survival. Nephrotoxicity is difficult to distinguish from chronic allograft
rejection and is a particular problem in the setting of renal transplantation.
Minimizing immunosuppressant-induced nephrotoxicity could improve long-term renal
allograft survival. However, to obtain significant long-term improvement in renal
allograft outcomes, it may be necessary to adopt new immunosuppressive regimens
that rely less on calcineurin inhibitors. Recipients of other transplanted
organs, as well as patients with autoimmune diseases who require
immunosuppressant therapy, could also benefit from this change in
immunosuppressive drug strategy because their healthy, native kidneys are
particularly susceptible to the nephrotoxic effects of CsA and FK506. CsA- and
FK506-sparing regimens, which use reduced doses of CsA and FK506 in combination
with other nonnephrotoxic immunosuppressants, may be the best current option for
reducing nephrotoxicity. The chemical immunosuppressant mycophenolate mofetil
(MMF) has been used as part of CsA- and FK506-sparing regimens that provide
improved renal function while maintaining adequate immunosuppression. Such
regimens should reduce patient morbidity and mortality. Also, because
immunosuppressant-induced nephrotoxicity has been associated with significant
financial costs, CsA- and FK506-sparing regimens should result in substantial
savings in health care costs.
PMID- 10676739
TI - Incidence and spectrum of dialysis-associated cancer in three continents.
PMID- 10676740
TI - Staphylococcus aureus pneumonia, hyponatremia, hypertension, proteinuria, and
hematuria in a 14-year-old boy.
PMID- 10676741
TI - Pathogenesis of anaphylactoid reactions to intravenous iron.
PMID- 10676742
TI - Prolonged slow dialysis and better survival.
PMID- 10676743
TI - Mandatory cardiac surgery in a patient with a recent history of cholesterol
crystal embolism.
PMID- 10676744
TI - Identical glomerulopathy in two different mouse models of uteroglobin deficiency.
PMID- 10676745
TI - Does imbalance between basal ganglia and cerebellar outputs cause movement
disorders?
PMID- 10676746
TI - Normal pressure hydrocephalus: developments in determining surgical prognosis.
AB - Research into normal pressure hydrocephalus has often focused on the clinical
dilemma of selecting patients who will benefit from cerebrospinal fluid
diversion. Recent developments in imaging and lumbar infusion tests are throwing
light on the underlying pathophysiology, providing researchers with new avenues
for the development of reliable investigative tools.
PMID- 10676747
TI - Neoplasms.
PMID- 10676748
TI - Medulloblastoma.
AB - The utilization of multi-modal therapy in the treatment of medulloblastoma has
improved survival rates and overall outcome. Recent large clinical trials have
supported the use of radiation and chemotherapy as adjuvant treatment. Treatment
advances have been made despite a poor understanding of the biological
underpinnings of medulloblastoma. Current laboratory investigations are shedding
light on the oncogenesis of medulloblastoma and may lead to improved treatments.
PMID- 10676749
TI - Primary central nervous system lymphoma.
AB - Primary central nervous system (CNS) lymphoma is an unusual but increasingly
frequent brain tumor being identified by neurologists. Considerable improvements
in survival have been accomplished by the addition of chemotherapy to cranial
radiotherapy. In addition, many patients achieve substantial disease free
survival with chemotherapy alone, and survival is superior to radiotherapy alone.
Currently, every patient should be considered for chemotherapy as the first line
of treatment. Subsequent cranial radiotherapy may or may not be necessary
depending upon the patient's clinical condition, age and response to initial
chemotherapy. Intensification of multi-agent chemotherapy is under study and it
is anticipated that the incidence of neurotoxicity will reduce with elimination
of combined modality treatment.
PMID- 10676750
TI - Recent advances in the diagnosis and treatment of central nervous system germ
cell tumours.
AB - Primary germ-cell tumors of the central nervous system are rare neoplasms that
are seen primarily in the pediatric age group. Because of their frequent location
in the pituitary and suprasellar regions, they present with typical neuro
ophthalmologic and neuroendocrine symptoms. Sophisticated imaging and surgical
biopsy allow precise anatomic definition, but only allow an approximate guess of
the tumor histopathology. Tumor markers in the serum and cerebrospinal fluid are
extremely helpful in the diagnosis and monitoring of response to treatment when
they are detectable. Because of the deleterious effects of irradiation on
neurocognitive and neuroendocrine functioning, we have looked at strategies that
either reduce or eliminate radiation exposure. Large, randomized, prospective,
cooperative trials in the future will be the only way to identify subgroups of
patients that may benefit from particular treatment strategies.
PMID- 10676751
TI - Rationales for improving motor function.
AB - New findings in basic neuroscience, and the growing knowledge regarding
neuroplasticity and motor learning have exerted influence and have provided
stimuli for motor rehabilitation research. Repeated motor practice has been
identified as crucial for motor recovery. Further novel and scientifically based
therapeutic approaches have been developed: constraint-induced movement therapy,
electromyogram-initiated neuromuscular stimulation, motor imagery and music
therapy are all discussed in the present review.
PMID- 10676752
TI - Setting goals for cognitive rehabilitation.
AB - Evidence for experience-dependent plasticity of the brain, including cell
regeneration, means that rehabilitation can aim at reinstituting impaired
cognitive function, as well as at training compensatory strategies for the lost
function. New theoretical frameworks make predictions regarding the circumstances
under which these two approaches should each be attempted. There has been
progress over the past 6 years in designing effective rehabilitation strategies,
with more of these having a strong theoretical basis in cognitive neuroscience.
Basic cognitive science has generated counter-intuitive, but effective cognitive
rehabilitation methods, showing that the goal of rehabilitation need not always
be the most obvious one dictated by real life performance. Limb Activation
Training for unilateral neglect is an example of a theoretically derived
cognitive rehabilitation procedure that has now been clinically evaluated in
clinical trials.
PMID- 10676753
TI - Mapping plastic brain changes after acute lesions.
AB - The combination of different mapping techniques has yielded new insights in
reorganization processes after acute lesions in humans. Recent research focused
not only on lesion-induced plasticity, but also on therapy-induced reorganization
of the brain. Data from animal experiments has expanded our knowledge of
mechanisms that underlie plastic changes.
PMID- 10676754
TI - Experimental models of brain trauma.
AB - A short review of the most widely used and popular experimental models of
traumatic brain injury is presented. This review focuses on current animal models
of traumatic brain injury that apply mechanical energy to the skull or, after
trephination of the skull, to the intact dura. Recent experimental studies
evaluating the pathobiology of traumatic brain injury using these models are also
discussed. This article attempts to provide a broad overview of current knowledge
and controversies in experimental animal research on brain trauma.
PMID- 10676755
TI - Metabolic disorders and neurotoxicology.
PMID- 10676756
TI - The pathogenesis of neurodegenerative disease: neurotoxic mechanisms of action
and genetics.
AB - The role of environmental and occupational exposures to neurotoxicants in the
pathogenesis of neurodegenerative disease has not been fully elucidated. Recent
published research on whether genetic polymorphisms contribute to individual
susceptibility to develop neurodegenerative diseases such as Parkinson's disease
have been equivocal at best. This review relates putative mechanisms of
neurotoxicant-induced cell damage to polymorphisms in the genes that encode for
the enzymes involved in the metabolism of neurotoxicants. The effects that
genetically induced alterations in enzyme functioning have on neurotoxicant
metabolism and how this relates to the risk of neurotoxic effects among exposed
individuals are reviewed. A pragmatic approach to future research in the area of
neurodegenerative disease is developed on the basis of the interrelationship
between known routes of neurotoxicant metabolism and human genetics.
PMID- 10676757
TI - Neurotoxicants and the cytoskeleton.
AB - Exposure to occupational and environmental toxicants can result in distal
axonopathies through reaction with various components of the axonal cytoskeleton.
The solvents n-hexane and methyl n-butyl ketone are metabolized to the beta
diketone, 2,5-hexanedione, which covalently cross-links neurofilaments, resulting
in large paranodal axonal swellings filled with neurofilaments. Carbon disulfide
exposure leads to an identical axonopathy, achieving neurofilament cross-linking
through a parallel series of reactions. Acrylamide and ethylene oxide, on the
other hand, adduct proteins but do not lead to cross-linking. These toxicants
appear to affect the function of microtubule-associated proteins, such as
kinesin, and result in the impaired transport of synaptic vesicles.
PMID- 10676758
TI - Tracking cholinergic pathways from psychological and chemical stressors to
variable neurodeterioration paradigms.
AB - Cholinergic hyperexcitation can be induced by both acute psychological stress and
exposure to acetylcholinesterase inhibitors. Both factors are known risk factors
for delayed neurodeterioration processes such as Alzheimer's disease and
Parkinson's disease. Recent publications on the involvement of cholinergic
pathways in these and other neurodeterioration syndromes are reviewed.
PMID- 10676759
TI - Neurotoxic effects of endocrine disruptors.
AB - Endocrine disrupting chemicals are a newly defined category of environmental
contaminants that may affect animal and human populations by interfering with
normal hormone action. There is substantial concern that these agents could have
a range of subtle and long-lasting effects. Because of the sensitivity of the
developing central nervous system to low levels of endogenous gonadal hormones
during development, the central nervous system may be a target for the action of
endocrine disrupting chemicals.
PMID- 10676760
TI - Magnetic resonance spectroscopy in toxic encephalopathy and neurodegeneration.
AB - Magnetic resonance spectroscopy allows neurochemistry to be probed noninvasively
in vivo. Recent advances in our understanding of the biochemical significance of
the various neurochemicals that are observable allow a variety of pathologic
states of relevance to encephalopathies and neurodegenerative disorders to be
observed. Measurements of brain glutamate and glutamine allow observation of
neuronal/glial substrate cycling and ammonia detoxification. Myo-inositol allows
changes in cerebral osmolarity and gliosis to be observed. N-acetylaspartate is a
marker of neuronal health and number. Lactate allows nonoxidative glycolysis to
be observed. These molecules are now being used to ask etiologic questions that
are of relevance to encephalopathies and neurodegeneration, as well to probe
longitudinally both natural history and therapeutic interventions in these
conditions. Combined with recent advances in anatomic magnetic resonance imaging
as well as perfusion magnetic resonance imaging, magnetic resonance spectroscopy
has the potential to aid greatly in our understanding of neuronal dysfunction in
a wide variety of neurologic pathologies, even in single patients.
PMID- 10676761
TI - Multiple antioxidants in the prevention and treatment of neurodegenerative
disease: analysis of biologic rationale.
AB - Parkinson's disease and Alzheimer's disease are major progressive neurologic
disorders, the risk of which increases with advancing age (65 years and over). In
familial cases, however, early onset of disease (35-65 years) is observed. In
spite of extensive basic and chemical research on Parkinson's disease and
Alzheimer's disease, no preventive or long-term effective treatment strategies
are available. The analysis of existing literature suggests that oxidative stress
is a major intermediary risk factor for the action of diverse groups of
neurotoxins that are involved in these neurodegenerative diseases. In this
review, it is proposed that the epigenetic components (mitochondria, other
organelles, membranes, protein modification) rather than nuclear genes of neurons
are the primary targets for the action of neurotoxins, including free radicals.
In addition, a scientific rationale for using multiple antioxidants in clinical
trials for the prevention of Parkinson's disease and Alzheimer's disease among
high-risk populations, and as an adjunct to standard therapy in the treatment of
these diseases is presented.
PMID- 10676762
TI - Bibliography. Current world literature. Degenerative diseases.
PMID- 10676763
TI - Bibliography. Current world literature. Neoplasms.
PMID- 10676764
TI - Bibliography. Current world literature. Trauma and rehabilitation.
PMID- 10676765
TI - Bibliography. Current world literature. Metabolic disorders and neurotoxicology.
PMID- 10676766
TI - Hematology and oncology
PMID- 10676767
TI - Idiopathic thrombocytopenic purpura: beyond consensus.
AB - Idiopathic thrombocytopenic purpura (ITP) is the most common acquired bleeding
disorder encountered by pediatricians. Most children with ITP have minimal
bleeding and complete platelet count recovery within weeks to months. Therapy for
ITP has ranged from close observation without medical intervention to aggressive
management with corticosteroids, intravenous immunoglobulin G, or anti-D immune
globulin. The topic of ITP has incited great debate among practitioners, and this
debate prompted the development of ITP practice guidelines by the British
Paediatric Haematology Group in 1992 and by the American Society of Hematology in
1996. A better understanding of the clinical course of, risk for significant
bleeding in, and optimal evaluation and therapy of childhood ITP will require
carefully designed, multicenter, clinical trials.
PMID- 10676768
TI - Oncology practice patterns in the use of hematopoietic growth factors.
AB - Recombinant hematopoietic growth factors were introduced into clinical practice a
decade ago: erythropoietin in 1989, granulocyte colony-stimulating factor (G-CSF)
and granulocyte-macrophage colony-stimulating factor (GM-CSF) in 1991, and
interleukin-11 in 1997. The role of these agents in supportive therapy for
children with cancer is still under considerable evaluation. This pediatric-based
review summarizes current clinical applications, practice guidelines, and
practice patterns for hematopoietic growth factors in the supportive care of
children with cancer. It also discusses ongoing controversies and unanswered
questions.
PMID- 10676769
TI - Return of granulocyte transfusions.
AB - Recently, several groups have begun to administer granulocyte colony-stimulating
factor (G-CSF), a hematopoietic growth factor, with or without dexamethasone to
mobilize peripheral blood neutrophils. Granulocyte colony-stimulating factor (600
microg subcutaneously) and dexamethasone (8 mg orally) given 12 hours before
standard leukapheresis routinely results in the collection of approximately 80 x
10(9) granulocytes. This number of cells is sufficient to increase the neutrophil
count of a severely neutropenic patient to normal and restore the recipients'
ability to develop a neutrophil response in tissues. Several trials are ongoing
to establish the clinical benefit of this new approach to supportive care for
neutropenic patients.
PMID- 10676770
TI - Thrombotic thrombocytopenic purpura and the hemolytic-uremic syndrome.
AB - Large and unusually large von Willebrand factor (vWf) multimers may be
responsible for systemic platelet aggregation in thrombotic thrombocytopenic
purpura (TTP). This possibility is supported by studies that show deficient vWf
cleaving metalloproteinase and increased platelet-vWf binding during TTP
episodes. In acute idiopathic TTP, decreased vWf metalloproteinase is the result
of autoantibodies against the enzyme. In familial and acquired hemolytic-uremic
syndrome, vWf-cleaving metalloproteinase activity is normal. A deficiency or
defect in factor H, which normally dampens the activation of C3 via the
alternative complement pathway, has been seen in some patients with familial
hemolytic-uremic syndrome. Ticlopidine therapy is an important risk factor for
TTP.
PMID- 10676771
TI - Congenital and inherited polycythemia.
AB - Absolute polycythemia is a condition with increased red blood cell mass. There
are a number of primary and secondary polycythemic disorders leading to absolute
polycythemia. Primary polycythemias are caused by a defect intrinsic to the
erythroid progenitor cells. The best characterized primary polycythemia is the
autosomal dominant primary familial and congenital polycythemia (PFCP). Familial
or childhood occurrence of the myeloproliferative disorder polycythemia vera are
also discussed, emphasizing the importance of distinction between polycythemia
vera and PFCP. Congenital or familial secondary polycythemic conditions are
characterized by increased red cell mass, which is caused by circulating serum
factors, typically erythropoietin.
PMID- 10676772
TI - More than skin deep.
PMID- 10676773
TI - Perinatal brachial plexus palsy.
AB - Perinatal brachial plexus palsy (PBPP) has been traditionally classified into
three types: upper plexus palsy (Erb's) affecting the C5, C6, and +/- C7 nerve
roots, lower plexus palsy (Klumpke's) affecting the C8 and T1 nerve roots, and
total plexus palsy. Although most cases will resolve spontaneously, the natural
history of the remaining cases is influenced by contractures of uninvolved muscle
groups and subluxation or dislocation of the shoulder and elbow. Microsurgical
nerve repair has demonstrated to provide improved outcomes compared to
conservative treatment, while advancements in secondary reconstruction have
offered significant improvements in the performance of activities of daily living
for older children with unresolved plexus palsy.
PMID- 10676774
TI - Transient synovitis as a cause of painful limps in children.
AB - Transient synovitis of the hip is one of the most common causes of hip pain and
limp in young children. Its cause is still largely unknown, but its natural
history is that of a self-limiting disorder with no residual sequelae, although
recurrences are possible. Because this benign condition is similar to more
significant disorders, such as septic arthritis, the diagnosis should remain one
of exclusion. Once transient synovitis is diagnosed, treatment consists of rest,
anti-inflammatory agents, and a tincture of time.
PMID- 10676775
TI - Ankle injuries in the pediatric population.
AB - Ankle injuries occur with considerable frequency in the pediatric population,
although diagnosis is rarely straightforward. In this paper, we highlight the
more common pitfalls in diagnosis and management, calling upon classic and
contemporary literature and our own combined 30-year experience in managing
pediatric lower extremity problems.
PMID- 10676776
TI - Congenital scoliosis.
AB - Congenital scoliosis is a deformity of the developing spine that results from
defects in vertebral development. The developmental etiologies may be classified
as either a failure of formation, a failure of segmentation, or a mixture of
these two modes of maldevelopment. Early detection and close surveillance of
congenital scoliosis is critical, as a rapidly progressive curve may lead to
significant deformity, pulmonary restriction, and neurologic problems if not
treated. Early surgical treatment is often necessary for rapidly progressive
curves.
PMID- 10676777
TI - Pediatric spinal injury.
AB - Spine injury in children thankfully is still a relatively rare injury. The
incidence of pediatric spine injuries has been reported as 2% to 5% of all spine
injuries. The biological differences of children make differences in fracture
patterns and alter the management necessary for successful treatment. The other
factors that affect fracture production and associated injuries are head size
relative to the body size, flexibility of the spine and supporting structures,
the growth plates, and the elasticity and compressibility of the bone. The
majority of compression injuries in children are made up of falls from a height.
Spinal injuries in children remain a challenge despite some technical changes in
assessment and treatment.
PMID- 10676778
TI - Advances in the medical treatment of juvenile rheumatoid arthritis.
AB - Juvenile rheumatoid arthritis (JRA) remains a challenge for clinicians.
Nonsteroidal anti-inflammatory drugs and corticosteroids remain the mainstays of
therapy, but concerns persist about side effects and the ability of these agents
to prevent progression of bony disease. In recent years, novel treatments have
been developed and quickly discarded because of unexpected toxicities or lack of
efficacy. However, recent studies have shown that methotrexate and sulfasalazine
are relatively safe and effective for JRA. Newly developed drugs, such as
selective cyclooxygenase-2 inhibitors and soluble tumor necrosis factor receptor,
whose development has stemmed from a more basic understanding of pathophysiology,
may provide better disease control with fewer side effects. Finally, novel
therapies, such as stem cell transplantation, may offer hope for children with
JRA, especially systemic-onset JRA, whose disease has been refractory to
conventional therapy.
PMID- 10676780
TI - Bibliography. Current world literature. Hematology and oncology.
PMID- 10676779
TI - Fever without apparent source on clinical examination, lower respiratory
infections in children, and enterovirus infections.
AB - This section focuses on issues in infectious disease that are commonly
encountered in pediatric office practice. McCarthy discusses recent literature
regarding the evaluation and management of acute fevers without apparent source
on clinical examination in infants and children and the evaluation of children
with prolonged fevers of unknown origin. Klig reviews recent literature about
lower respiratory tract infection in children. Finally, Kennedy and Kahn discuss
recent developments in infectious diseases pertinent to office practice.
PMID- 10676781
TI - Bibliography. Current world literature. Orthopedics.
PMID- 10676782
TI - Confirmation of confocal microscopy diagnosis of Acanthamoeba keratitis using
polymerase chain reaction analysis.
AB - BACKGROUND: Acanthamoeba keratitis has commonly been identified with in vivo
confocal microscopy and confirmed with histologic examination of an epithelial
biopsy specimen. OBJECTIVE: To determine if Acanthamoeba keratitis can be
verified using polymerase chain reaction (PCR) of epithelial biopsy specimens.
METHODS: Epithelial specimens from patients with suspected Acanthamoeba keratitis
by confocal microscopy were tested for Acanthamoeba with PCR of Acanthamoeba
ribosomal DNA. RESULTS: Twenty-four of 31 patients with evidence of Acanthamoeba
keratitis were positive for Acanthamoeba on PCR analysis using 3 sets of primers.
In 22 cases, the sequence obtained closely matched Acanthamoeba castellanii.
CONCLUSIONS: This study demonstrates that PCR analysis of epithelial biopsy
specimens can provide definitive verification of the confocal microscopic and
histologic identification of Acanthamoeba organisms associated with keratitis.
Acanthamoeba keratitis is probably quite common, especially in contact lens
wearers, although more than half of the patients in this study did not wear
contact lenses.
PMID- 10676783
TI - Iridocorneal endothelial syndrome in Thai patients: clinical variations.
AB - OBJECTIVE: To evaluate the spectrum of iridocorneal endothelial syndrome, to our
knowledge, never studied previously in Orientals. METHODS: From 1986 to 1998, we
examined 60 consecutive patients (20 men, 40 women) with characteristic signs of
iridocorneal endothelial syndrome and compared the clinical manifestations to
those reported in white patients. RESULTS: Cogan-Reese syndrome (CRS) was most
common (38 patients), while 14 patients had Chandler syndrome (CS), and 8 had
progressive iris atrophy. Three patients initially classified as having CS and 1
as having progressive iris atrophy progressed to CRS. Glaucoma occurred in 46
patients (76.7%), most commonly in patients with progressive iris atrophy or CRS.
Ten patients had slow progression of disease during the follow-up period of up to
12 years. Three patients (2 with CRS, 1 with CS) had asymptomatic localized
islands of "hammered-silver" appearance and 11 (8 with CRS, 2 with CS, and 1 with
progressive iris atrophy) had subclinical abnormal endothelium in the
contralateral eyes. A translucent membrane was commonly seen on the brown iris
surface. Total endothelial involvement was present in 49 patients, while 6 (4
with CRS, 2 with CS) had focal endothelial abnormalities with sharp demarcation
from adjacent normal endothelium. CONCLUSIONS: Iridocorneal endothelial syndrome
occurs in Orientals. Cogan-Reese syndrome is the most common form and is strongly
associated with glaucoma. Although several clinical manifestations were similar
between whites and Orientals (mean age of onset, sex predilection, iris changes,
peripheral anterior synechiae formation, or corneal edema), CRS was most
prevalent; a translucent membrane were more noticeable in Orientals.
PMID- 10676784
TI - Scanning laser ophthalmoscope correlations with biomicroscopic findings and
foveal function after macular hole closure.
AB - OBJECTIVE: To investigate the relation between foveal findings and visual
function in eyes with a resolved idiopathic macular hole after vitreous surgery.
METHODS: We divided 28 eyes with postoperative idiopathic macular hole resolution
into 3 groups based on postoperative biomicroscopic foveal findings of complete
closure, partial closure, or atrophic closure. To evaluate foveal retinal
function, scanning laser ophthalmoscope (SLO) microperimetry was performed
preoperatively and 6 months postoperatively. RESULTS: Postoperatively in 18 eyes
(64%), the foveal images became normal or almost normal and were classified as
having complete closure, 6 eyes (21%) were classified as having partial closure,
and 4 eyes (14%) as having atrophic closure. The corresponding visual acuity
levels 6 months postoperatively were, respectively, 0.10, 0.35, and 0.64 (P<.01)
based on LogMAR analysis. Preoperative SLO microperimetry detected an absolute
scotoma at the bottom of all macular holes; postoperatively, the absolute scotoma
disappeared in the 18 eyes with complete hole closure, but a relative scotoma was
detected in 6 eyes. Of 6 eyes with partial closure, 1 had an absolute scotoma and
5 had a relative scotoma. An absolute scotoma was detected in 4 eyes with
atrophic closure. CONCLUSIONS: After macular hole closure, SLO findings correlate
both with biomicroscopic findings and foveal function. Better anatomical foveal
recovery in eyes after macular hole closure results in better improvement of
vision than in eyes in which the foveal anatomical findings are not as good.
PMID- 10676785
TI - Observations on 17 patients with retinocytoma.
AB - OBJECTIVE: To study the clinical features and natural history of 17 patients with
retinocytoma. DESIGN: A retrospective case series. SETTING: Tertiary referral
center. PATIENTS: Data on 17 patients with retinocytoma were reviewed for
clinical features. The natural history of retinocytoma and its risk for malignant
transformation were also evaluated. RESULTS: Among 920 consecutive patients who
had retinoblastoma, retinocytoma, or both, we identified 24 tumors in 17 patients
(1.8%) with clinical features compatible with retinocytoma. The median age at
diagnosis was 15 years (range, 4-45 years). Of the 24 tumors, the retinocytoma
was bilateral in 3 cases (13%) and the family history of retinoblastoma was
positive in 3 cases (13%). Seventeen (71%) of the tumors were extramacular in
location, and 7 (29%) were located in the macular area. Ophthalmoscopic features
characteristic of retinocytoma included the presence of a translucent retinal
mass in 21 (88%), calcification in 15 (63%), and retinal pigment epithelial
alteration in 13 (54%) of the 24 tumors. A combination of all 3 features was
observed in 8 (33%) of the 24 tumors. In 13 (54%) of the tumors, a zone of
chorioretinal atrophy could be observed. In 1 patient, subtle tumor regression
was documented photographically. Only 1 retinocytoma (4%) underwent malignant
transformation into retinoblastoma. At the last follow-up visit, none of the
patients had developed a pineoblastoma or another second malignant neoplasm.
CONCLUSIONS: Retinocytoma is a rare benign retinal tumor that has characteristic
clinical features. The areas of chorioretinal atrophy were suggestive of tumor
regression. In our series, the risk for malignant transformation of retinocytoma
into retinoblastoma was 4%; therefore, patients with a presumed diagnosis of
retinocytoma should be closely observed.
PMID- 10676786
TI - Choroidal laser Doppler flowmetry in healthy subjects.
AB - OBJECTIVE: To evaluate normal choroidal blood flow and its relationship with
various factors such as age, systemic blood pressure, and intraocular pressure
(IOP). METHODS: A total of 70 healthy subjects were recruited. Choroidal blood
flow was assessed using a method based on laser Doppler flowmetry (LDF)
technique. The LDF parameters of velocity, volume, and flux were obtained. The
influence of age, mean systemic blood pressure, IOP, smoking, and sex on
choroidal hemodynamic parameters was assessed in a multiple linear regression
model. The correlations between interocular difference in IOP and interocular
differences in the LDF parameters were assessed by means of the Pearson linear
correlation factor. RESULTS: Velocity decreased significantly (P = .03) with
advancing age of the subjects and volume increased significantly (P = .02) with
increasing IOP. Mean blood pressure, smoking, and sex had no influence on the
choroidal LDF parameters. Interocular difference in IOP correlated significantly
with interocular difference in volume (R = 0.34, P<.005). CONCLUSION: Choroidal
blood flow velocity decreased with increasing age of the subjects, while the
volume of moving erythrocytes decreased with lower IOP.
PMID- 10676787
TI - Metastatic neoplasms in the optic disc: the 1999 Bjerrum Lecture: part 2.
AB - BACKGROUND: Little information is available on metastatic tumors to the optic
disc. OBJECTIVE: To determine the clinical features and prognosis of patients
with optic disc metastasis. DESIGN: Retrospective chart review. RESULTS: Of 660
consecutively evaluated patients with intraocular metastasis, 30 (4.5%) (31 eyes)
had metastatic cancer to the optic disc; 24 (80%) were women and 6 (20%) were
men. Mean age at the time of ocular diagnosis was 55 years. The primary neoplasm
was in the breast in 13 patients (43%), in the lung in 8 (27%), in the intestine
in 1 (3%), in the kidney in 1 (3%), and in the prostate in 1 (3%); the primary
neoplasm was never determined in 6 patients (20%). The optic disc metastasis was
unilateral in 29 patients (97%) and bilateral in 1 (3%). Ophthalmoscopically, the
disc metastasis appeared as a diffuse enlargement of the optic disc in 26 eyes
(84%) and as a distinct nodule in 5 (16%). There was an adjacent juxtapapillary
choroidal component to the metastatic disc lesion in 23 eyes (74%), and the optic
disc was involved without a retinal or choroidal component in 8 (26%). Other
associated findings included some degree of secondary disc edema in all eyes,
buried disc blood vessels in 23 (74%), and splinter hemorrhages in 13 (42%). Fine
needle aspiration biopsy was useful in establishing the diagnosis in all 5 eyes
in which it was performed. Mean survival was 13 months after diagnosis of the
disc metastasis. CONCLUSIONS: Metastasis to the optic disc accounts for 5% of all
intraocular metastases. It can occur as invasion from a juxtapapillary choroidal
metastasis or as isolated optic disc metastasis. Breast and lung cancers are the
most common primary neoplasms that account for metastasis to the optic disc. The
primary site is never determined in 20% of patients. The characteristic clinical
features of optic disc metastasis should help differentiate it from other causes
of swollen optic disc. Patient prognosis is poor.
PMID- 10676788
TI - Melkersson-Rosenthal syndrome: new clinicopathologic findings in 4 cases.
AB - OBJECTIVE: To define the clinicopathologic features of eyelid involvement in
Melkersson-Rosenthal syndrome (MRS). METHODS: Four patients with eyelid edema
consistent with MRS were evaluated clinically, including diagnostic imaging in 2
patients. Eyelid tissue from these patients was examined by light microscopy and
immunohistochemistry. Polymerase chain reaction for herpes simplex virus was
performed in 1 case. RESULTS: The 3 men and 1 woman ranged in age from 33 to 74
years. All patients had insidious, painless, nonpitting eyelid edema. Three
patients had unilateral edema; one had bilateral, asymmetric involvement.
Ipsilateral lip edema was present in 1 case. Computed tomography demonstrated
periorbital heterogeneous thickening that corresponded to the microscopic finding
of scattered granulomas. All 4 patients demonstrated epithelioid granulomas
inside and adjacent to dilated lymphatic vessels. Polymerase chain reaction
testing was negative for herpes simplex virus. CONCLUSIONS: Isolated eyelid
swelling that mimics thyroid-associated ophthalmopathy may occur in MRS. Computed
tomography may be useful in the diagnosis. Biopsy should be performed in all
cases of unexplained nonpitting eyelid edema. In the eyelid, MRS is characterized
histopathologically by a granulomatous lymphangitis, a finding that seems to be
unique to this condition.
PMID- 10676789
TI - Swelling and loss of photoreceptors in chronic human and experimental glaucomas.
AB - OBJECTIVE: To determine whether outer retinal changes occur in chronic, presumed
primary open-angle glaucoma (POAG). METHODS: The outer retinas from 128 human
eyes with a diagnosis of chronic glaucoma (presumably POAG in most cases) and 90
control eyes were examined histologically by 3 masked observers for photoreceptor
swelling and loss. Retinas from 9 rhesus monkeys with glaucoma induced
experimentally by laser trabecular destruction were compared with 7 fellow
(control) eyes. The mean pressure elevations in the eyes with laser trabecular
destruction ranged from 26.6 to 53.6 mm Hg with durations varying from 7 to 33
weeks. RESULTS: Swelling of the red- and green-sensitive cones was observed in a
statistically significantly greater proportion of human eyes with presumed POAG
compared with the control eyes. Patchy loss of red/green cones and rods was also
found in some of the glaucomatous retinas. In a subset of the human eyes with end
stage disease, cone swelling was a variable finding. Although no photoreceptor
loss was found in the 9 monkey eyes with experimental glaucoma, 8 had swelling of
their red/green cones that was remarkably similar to that seen in the human eyes.
Swelling was not present in any of the control monkey eyes. CONCLUSIONS: The
photoreceptors are affected by chronically elevated intraocular pressure.
CLINICAL RELEVANCE: These findings may explain some of the abnormalities of color
vision and the electrophysiological effects that have been observed in patients
with POAG.
PMID- 10676790
TI - Tear production after unilateral removal of the main lacrimal gland in squirrel
monkeys.
AB - OBJECTIVE: To study the effects of lacrimal gland removal on basal and reflex
tear production and on the ocular surface in the squirrel monkey. METHODS:
Unilateral main lacrimal gland removal in 6 squirrel monkeys was followed by
Schirmer testing, slit-lamp examination with fluorescein, and collection of basal
and reflex (stimulated) tears for analysis of tear protein spectra between 0 and
20 kd, as well as histological evaluation. RESULTS: Schirmer test results showed
an 80% decrease in basal tears and a 90% decrease in reflex tears during week 1,
and a 32.2% and 33.3% decrease, respectively, at week 20 after surgery, compared
with the contralateral control side. However, no gross abnormalities or
fluorescein staining were seen in 5 of the 6 monkeys, and the conjunctival
surfaces remained normal. The main and accessory lacrimal glands appeared to
secrete similar types of proteins. No histological changes were seen in corneal,
conjunctival, or eyelid tissues 20 weeks after surgery. CONCLUSIONS: Tears from
accessory lacrimal glands were sufficient to maintain a stable tear layer on the
cornea, suggesting that so-called basal tear flow is made up of fluid from both
main and accessory lacrimal glands and that decreased tear production by the main
lacrimal gland is not a causative factor in keratoconjunctivitis sicca. CLINICAL
RELEVANCE: This study shows that total removal of the main lacrimal gland does
not in itself lead to keratoconjunctivitis sicca. However, the nature of neural
control of the accessory glands is not yet clear.
PMID- 10676791
TI - Surgical undertreatment of glaucoma in black beneficiaries of medicare.
AB - OBJECTIVE: To identify whether there was surgical undertreatment of glaucoma in
black beneficiaries of Medicare from 1991 to 1994. METHODS: We performed a
retrospective cohort analysis on all argon laser trabeculoplasty or
trabeculectomy surgery claims to the Health Care Financing Administration between
1991 and 1994. There were 191 287 Medicare patients who were black or white, at
least 65 years of age, and resided in the United States at the time of their
glaucoma surgery. Age- and sex-adjusted rates were obtained and compared with
surgery rates expected based on disease prevalence. RESULTS: The age-sex-adjusted
rate ratio of glaucoma surgical procedures for blacks to whites was 2.14.
Assuming that treatments should be done in proportion to age-race prevalence,
blacks undergo glaucoma surgery at approximately 47% below the expected rate.
CONCLUSIONS: Blacks underwent argon laser trabeculoplasties and trabeculectomies
at half the rate of whites from 1991 to 1994. Although in 1993 and 1994 there was
a slight trend toward higher surgery rates in blacks, the magnitude of this
improvement was small compared with estimated differences in the surgery rates
between blacks and whites.
PMID- 10676792
TI - Anterior chamber depth measurement as a screening tool for primary angle-closure
glaucoma in an East Asian population.
AB - OBJECTIVE: To evaluate anterior chamber depth measurement as a method of
screening for primary angle-closure glaucoma in an East Asian population. DESIGN:
Two-phase, cross-sectional, community-based study. SETTING: Rural and urban
locations in the Hovsgol and Omnogobi provinces, Mongolia. PARTICIPANTS: Nine
hundred forty-two (94.2%) of 1000 individuals in Hovsgol(1995) and 775 (96.9%) of
1000 individuals in Omnogobi (1997) aged 40 years or older were examined. MAIN
OUTCOME MEASURES: Anterior chamber depth was measured by optical pachymetry,
slitlamp-mounted A-mode ultrasound, and handheld ultrasound. Gonioscopy was used
to detect occludable angles, defined as one in which the trabecular meshwork was
visible for less than 90 degrees of angle circumference. Primary open-angle
glaucoma was diagnosed in subjects with an occludable angle and glaucomatous
optic neuropathy with visual morbidity. The area under the curve in a receiver
operating characteristic plot was used to compare test performance. RESULTS:
Optical pachymetry outperformed the slitlamp-mounted ultrasound method of
anterior chamber depth measurement (area under the curve, 0.93 and 0.90,
respectively; z test, P = .001). Handheld ultrasound (area under the curve, 0.86)
was inferior to optical measurement (z test, P = .001) but did not differ
significantly from slitlamp ultrasound (z test, P = .06). The optical method gave
sensitivity of 85% and specificity of 84% at a screening cutoff of less than 2.22
mm for detecting occludable angles. CONCLUSIONS: Measurement of axial anterior
chamber depth can detect occludable angles in this Asian population and therefore
may have a role in population screening for primary angle-closure glaucoma.
PMID- 10676793
TI - Age-specific causes of bilateral visual impairment.
AB - OBJECTIVES: To describe the age-specific prevalence of common eye diseases
causing bilateral visual impairment and estimate the total number of Australians
with cause-specific visual impairment. METHODS: Cluster-stratified random sample
of 5147 residents aged 40 years and older from urban and rural areas and aged
care facilities. Participants completed a standardized interview and eye
examination. Four levels of bilateral visual impairment were defined: less than
20/40 to 20/60 and/or homonymous hemianopia (mild), less than 20/60 to 20/200 or
better and/or less than 20 degrees to 10 degrees radius field (moderate), less
than 20/200 to 10/200 and/or less than 10 degrees to 5 degrees radius field
(severe), and less than 1O/ 200 and/or less than 50 radius field (profound). The
major cause of vision loss was identified for all participants found to be
visually impaired. RESULTS: Uncorrected refractive error was the most common
cause of bilateral visual impairment across all decades of life, rising from 0.5%
in 40- to 49-year-olds to 13% among those aged 80 years and older. Prevalence of
visual impairment due to diabetic retinopathy was 0.7% in 50- to 59-year-olds and
0.8% in those older than 80 years. Visual impairment due to glaucoma had a
prevalence of 0.7% among 60-year-olds and rose to 4% of those older than 90
years. The prevalence of visual impairment due to cataract (only present in those
aged 70 years or older) rose from 0.6% to 11% in those older than 90 years, and
the prevalence of visual impairment due to age-related macular degeneration rose
from 0.8% to 16% in those older than 90 years. CONCLUSIONS: The predominant
causes of visual impairment change with age. Recognition of these patterns is
fundamental for early diagnosis and treatment of eye disease and, where
appropriate, referral for rehabilitation.
PMID- 10676794
TI - The analysis of clinical research: mandatory submission of data sets. Journals
should have access to research data.
PMID- 10676795
TI - Journal editors should not require complete data sets for independent scrutiny.
PMID- 10676796
TI - Management of small corneal infiltrates in contact lens wearers.
PMID- 10676797
TI - T-cell lymphoproliferative disorder of vitreous associated with mycosis
fungoides.
AB - 59-year-old man with a history of mycosis fungoides developed loss of visual
acuity and visual field in the left eye. Epiretinal lesions were present in the
right eye and multifocal choroidal lesions, optic disc edema, and vitritis were
present in the left eye. A diagnostic vitrectomy was performed and cytologic
examination of the vitreous confirmed the diagnosis of T-cell lymphoproliferative
disorder. Systemic and intrathecal chemotherapy resulted in marked improvement in
ocular signs and symptoms. At last follow-up, the patient was found to have
improved visual acuity in the left eye; however, significant worsening of his
systemic condition developed and he died shortly thereafter.
PMID- 10676798
TI - Photorefractive keratectomy for correction of epikeratophakia regression.
PMID- 10676799
TI - Iatrogenic keratoconus: corneal ectasia following laser in situ keratomileusis
for myopia.
PMID- 10676800
TI - Treatment of conjunctival mucosa-associated lymphoid tissue lymphoma with
intralesional injection of interferon alfa-2b.
PMID- 10676801
TI - Spontaneous resolution of vitreomacular traction documented by optical coherence
tomography.
PMID- 10676802
TI - Acute bilateral visual loss associated with retinal hemorrhages following
epiduroscopy.
PMID- 10676803
TI - Capillary hemangioma of the optic nerve head and juxtapapillary retina.
PMID- 10676804
TI - Sildenafil (Viagra) associated anterior ischemic optic neuropathy.
PMID- 10676805
TI - Mycobacterium chelonae infection in a corneal graft.
PMID- 10676806
TI - Peculiar macular hemorrhage.
PMID- 10676807
TI - Retinopathy of NARP syndrome.
PMID- 10676808
TI - Codons 837 and 838 in the retinal guanylate cyclase gene on chromosome 17p: hot
spots for mutations in autosomal dominant cone-rod dystrophy?
PMID- 10676809
TI - Yeast prions and their prion-forming domain.
PMID- 10676810
TI - New roles for Src kinases in control of cell survival and angiogenesis.
PMID- 10676811
TI - Time flies for Drosophila.
PMID- 10676812
TI - Large-scale movement of elongation factor G and extensive conformational change
of the ribosome during translocation.
AB - Elongation factor (EF) G promotes tRNA translocation on the ribosome. We present
three-dimensional reconstructions, obtained by cryo-electron microscopy, of EF-G
ribosome complexes before and after translocation. In the pretranslocation state,
domain 1 of EF-G interacts with the L7/12 stalk on the 50S subunit, while domain
4 contacts the shoulder of the 30S subunit in the region where protein S4 is
located. During translocation, EF-G experiences an extensive reorientation, such
that, after translocation, domain 4 reaches into the decoding center. The factor
assumes different conformations before and after translocation. The structure of
the ribosome is changed substantially in the pretranslocation state, in
particular at the head-to-body junction in the 30S subunit, suggesting a possible
mechanism of translocation.
PMID- 10676813
TI - The crystal structure of human eukaryotic release factor eRF1--mechanism of stop
codon recognition and peptidyl-tRNA hydrolysis.
AB - The release factor eRF1 terminates protein biosynthesis by recognizing stop
codons at the A site of the ribosome and stimulating peptidyl-tRNA bond
hydrolysis at the peptidyl transferase center. The crystal structure of human
eRF1 to 2.8 A resolution, combined with mutagenesis analyses of the universal GGQ
motif, reveals the molecular mechanism of release factor activity. The overall
shape and dimensions of eRF1 resemble a tRNA molecule with domains 1, 2, and 3 of
eRF1 corresponding to the anticodon loop, aminoacyl acceptor stem, and T stem of
a tRNA molecule, respectively. The position of the essential GGQ motif at an
exposed tip of domain 2 suggests that the Gln residue coordinates a water
molecule to mediate the hydrolytic activity at the peptidyl transferase center. A
conserved groove on domain 1, 80 A from the GGQ motif, is proposed to form the
codon recognition site.
PMID- 10676814
TI - Sequence-specific RNA binding by a Nova KH domain: implications for
paraneoplastic disease and the fragile X syndrome.
AB - The structure of a Nova protein K homology (KH) domain recognizing single
stranded RNA has been determined at 2.4 A resolution. Mammalian Nova antigens (1
and 2) constitute an important family of regulators of RNA metabolism in neurons,
first identified using sera from cancer patients with the autoimmune disorder
paraneoplastic opsoclonus-myoclonus ataxia (POMA). The structure of the third KH
domain (KH3) of Nova-2 bound to a stem loop RNA resembles a molecular vise, with
5'-Ura-Cyt-Ade-Cyt-3' pinioned between an invariant Gly-X-X-Gly motif and the
variable loop. Tetranucleotide recognition is supported by an aliphatic alpha
helix/beta sheet RNA-binding platform, which mimics 5'-Ura-Gua-3' by making
Watson-Crick-like hydrogen bonds with 5'-Cyt-Ade-3'. Sequence conservation
suggests that fragile X mental retardation results from perturbation of RNA
binding by the FMR1 protein.
PMID- 10676815
TI - Role of Sec61alpha in the regulated transfer of the ribosome-nascent chain
complex from the signal recognition particle to the translocation channel.
AB - Targeting of ribosome-nascent chain complexes to the translocon in the
endoplasmic reticulum is mediated by the concerted action of the signal
recognition particle (SRP) and the SRP receptor (SR). Ribosome-stripped
microsomes were digested with proteases to sever cytoplasmic domains of SRalpha,
SRbeta, TRAM, and the Sec61 complex. We characterized protein translocation
intermediates that accumulate when Sec61alpha or SRbeta is inactivated by
proteolysis. In the absence of a functional Sec61 complex, dissociation of SRP54
from the signal sequence is blocked. Experiments using SR proteoliposomes
confirmed the assembly of a membrane-bound posttargeting intermediate. These
results strongly suggest that the Sec61 complex regulates the GTP hydrolysis
cycle of the SRP-SR complex at the stage of signal sequence dissociation from
SRP54.
PMID- 10676816
TI - Structure of the Rho family GTP-binding protein Cdc42 in complex with the
multifunctional regulator RhoGDI.
AB - The RhoGDI proteins serve as key multifunctional regulators of Rho family GTP
binding proteins. The 2.6 A X-ray crystallographic structure of the Cdc42/RhoGDI
complex reveals two important sites of interaction between GDI and Cdc42. First,
the amino-terminal regulatory arm of the GDI binds to the switch I and II domains
of Cdc42 leading to the inhibition of both GDP dissociation and GTP hydrolysis.
Second, the geranylgeranyl moiety of Cdc42 inserts into a hydrophobic pocket
within the immunoglobulin-like domain of the GDI molecule leading to membrane
release. The structural data demonstrate how GDIs serve as negative regulators of
small GTP-binding proteins and how the isoprenoid moiety is utilized in this
critical regulatory interaction.
PMID- 10676817
TI - Covalent modification regulates ligand binding to receptor complexes in the
chemosensory system of Escherichia coli.
AB - In the Escherichia coli chemosensory pathway, receptor modification mediates
adaptation to ligand. Evidence is presented that covalent modification influences
ligand binding to receptors in complexes with CheW and the kinase CheA. Kinase
inhibition was measured with serine receptor complexes in different modification
levels; Ki for serine-mediated inhibition increased 10,000-fold from the lowest
to the highest level. Without CheA and CheW, ligand binding is unaffected by
covalent modification; thus, the influence of covalent modification is mediated
only in the receptor complex, a conclusion supported by an analogy to allosteric
enzymes and the observation of cooperative kinase inhibition. Also, the finding
that a subsaturating serine concentration accelerates active receptor-kinase
complex assembly implies that the assembly/disassembly process may also
contribute to kinase regulation.
PMID- 10676818
TI - Integrated cytogenetic map of chromosome arm 4S of A. thaliana: structural
organization of heterochromatic knob and centromere region.
AB - We have constructed an integrated cytogenetic map of chromosome arm 4S of
Arabidopsis thaliana. The map shows the detailed positions of various multicopy
and unique sequences relative to euchromatin and heterochromatin segments. A
quantitative analysis of the map positions at subsequent meiotic stages revealed
a striking pattern of spatial and temporal variation in chromatin condensation
for euchromatin and heterochromatin. For example, the centromere region consists
of three domains with distinguishable structural, molecular, and functional
properties. We also characterized a conspicuous heterochromatic knob of
approximately 700 kb that accommodates a tandem repeat and several dispersed
pericentromere-specific repeats. Moreover, our data provide evidence for an
inversion event that relocated pericentromeric sequences to an interstitial
position, resulting in the heterochromatic knob.
PMID- 10676819
TI - The complete sequence of a heterochromatic island from a higher eukaryote. The
Cold Spring Harbor Laboratory, Washington University Genome Sequencing Center,
and PE Biosystems Arabidopsis Sequencing Consortium.
AB - Heterochromatin, constitutively condensed chromosomal material, is widespread
among eukaryotes but incompletely characterized at the nucleotide level. We have
sequenced and analyzed 2.1 megabases (Mb) of Arabidopsis thaliana chromosome 4
that includes 0.5-0.7 Mb of isolated heterochromatin that resembles the
chromosomal knobs described by Barbara McClintock in maize. This isolated region
has a low density of expressed genes, low levels of recombination and a low
incidence of genetrap insertion. Satellite repeats were absent, but tandem arrays
of long repeats and many transposons were found. Methylation of these sequences
was dependent on chromatin remodeling. Clustered repeats were associated with
condensed chromosomal domains elsewhere. The complete sequence of a
heterochromatic island provides an opportunity to study sequence determinants of
chromosome condensation.
PMID- 10676820
TI - Efficacy and safety of lesopitron in outpatients with generalized anxiety
disorder.
AB - OBJECTIVE: To compare the relative efficacy and safety of lesopitron 4-80 mg/d
versus lorazepam 2-4 mg/d and placebo in a subgroup of patients with anxiety
history taken from a larger study of patients with a primary diagnosis of
generalized anxiety disorder (GAD). DESIGN: Six-week, randomized, double-blind,
parallel, placebo and lorazepam-controlled, Phase II, single-center, outpatient
study. SETTING: Outpatient clinic. PATIENTS: One hundred sixty-one patients with
GAD were randomized in the main study; 68 with a documented history of GAD or
anxiety disorder not otherwise specified were included in the subgroup. METHODS:
After a one-week placebo lead-in, patients were randomized to receive placebo,
lesopitron, or lorazepam twice daily for six weeks, followed by a one-week taper
period. Efficacy was assessed using the Hamilton Rating Scale for Anxiety (HAM-A)
and the Clinical Global Impressions scale. Safety was assessed through physical
examinations, monitoring of vital signs, 12-lead electrocardiograms, laboratory
analyses, and adverse event monitoring. RESULTS: An overall mean improvement in
the HAM-A total score between baseline and end point for all three treatment
groups was seen, with mean changes of 3.4 (95% CI 2.0 to 4.8), 6.1 (95% CI 4.1 to
8.1), and 6.1 (95% CI 4.6 to 7.6) for the placebo, lesopitron, and lorazepam
groups, respectively (omnibus p = 0.044, uncorrected). Positive treatment effects
were also observed in the subgroup population on several other measures and
suggest that additional therapeutic trials may be warranted. Future trials could
be stratified on the basis of referral status (symptomatic volunteer vs. clinical
patient with preexisting illness) or previous exposure to anxiolytics, and use a
fixed-dose rather than flexible-fixed-dose design. CONCLUSIONS: The subgroup
analysis represents a comparison of treatment outcome in GAD patients presenting
with a history of previous episodes of GAD or anxiety disorder not otherwise
specified compared with those who were experiencing their first episode of GAD
and reported no anxiety history. Although the overall study analysis was
equivocal, for the approximately 40% of patients with recurrent anxiety disorder,
beneficial effects for both lesopitron and lorazepam are suggested.
PMID- 10676821
TI - Economic impact of standardized orders for antimicrobial prophylaxis program.
AB - OBJECTIVE: To assess the effect and economic impact of an intervention aimed at
standardizing the timing of preoperative antimicrobial prophylaxis from the
perspective of a major teaching hospital. DESIGN: A pre/post study design in
which a random sample of 60 procedures from a 12-month period in the
preintervention phase were reviewed. A comparative sample of 60 procedures during
a seven-month postintervention phase was selected. For each prophylactic course,
preoperative dose administration details were classified as early (>2 h prior to
incision), on time (0-2 h prior), delayed (0-3 h after), or late (>3 after). To
determine the economic impact of this intervention, we used a predictive decision
analytic model using institutional costs and the published probabilities of
inpatient surgical wound infections (SWIs) following administration of
antimicrobials timed according to the above criteria. Two conditions were
analyzed: (1) an interdisciplinary two-stage therapeutic interchange program
involving staff education and modification of preoperative antimicrobial orders
to ensure timely administration and (2) no intervention. SETTING: An 1100-bed
tertiary care, university-affiliated institution. PATIENTS: 120 randomly selected
procedures involving inpatients who received a preoperative antibiotic. OUTCOME
MEASURES: Differences in preoperative antimicrobial timing and cost avoidance
associated with the intervention. RESULTS: In the preintervention phase, 68% of
prophylactic courses were on time, 22% were early, and the balance were delayed
or late. The incidence of on-time prophylaxis increased to 97% during the
postintervention phase (p = 0.001). Operating room staff involvement in
antimicrobial administration increased from 57% to 92% (p = 0.001). Based on a
setup and annual intervention cost of $9100 CAN ($1 CAN = $0.68 US), an annual
inpatient SWI avoidance of 51 cases, an average infection-associated extended
hospital stay of four days, and an average treatment cost of $1957 CAN per
inpatient SWI, we estimated that 153 hospital days were avoided and there was an
annual cost avoidance of $90 707 CAN ($1779 CAN saved per inpatient infection
avoided) due to this intervention. Using sensitivity analyses, no plausible
changes in the base case estimates altered the results of the economic model.
CONCLUSIONS: An interdisciplinary approach to optimizing the timing of
preoperative antimicrobial doses can impact positively on practice patterns and
result in substantial cost avoidance. Costs incurred to implement such an
intervention are small when compared with the annual cost avoidance to the
institution.
PMID- 10676822
TI - The pharmacokinetics of etanercept in healthy volunteers.
AB - OBJECTIVE: To describe the pharmacokinetics of etanercept when administered by
subcutaneous injection in single doses to healthy volunteers. METHODS: Twenty-six
healthy volunteers between 19 and 50 years of age received single doses of
etanercept 25 mg by subcutaneous injection into the abdomen. Serial serum samples
were collected for 21 days. An enzyme-linked immunosorbent assay with a
quantitation limit of 0.3 ng/mL was used to measure the drug concentrations.
RESULTS: Etanercept was well tolerated by healthy volunteers. A one-compartment
model was found to best describe the concentration-time data and was used to
determine the pharmacokinetic parameters. Etanercept is slowly absorbed from the
site of injection with a time of peak concentration (+/- SD) of 51 +/- 14 hours;
peak concentration was 1.46 +/- 0.72 mg/L. The AUC was 235 +/-98 mg x h/L,
apparent clearance was 132 +/- 85 mL/h, apparent volume of distribution was 12 +/
6 L, and the half-life was 68 +/- 19 hours. CONCLUSIONS: Etanercept was slowly
absorbed and slowly eliminated after subcutaneous administration. Dosing at the
recommended rate of 25 mg twice weekly would be expected to result in
concentrations of approximately 3 mg/L. Intersubject variability for apparent
clearance in healthy volunteers was 64%.
PMID- 10676823
TI - Toxicity of polysaccharide--iron complex exposures reported to poison control
centers.
AB - OBJECTIVE: To evaluate the toxicity of polysaccharide-iron complex (PIC)
exposures reported to poison centers in the US. DESIGN: A retrospective analysis
of potentially toxic exposures to PIC without concomitant substances reported to
the American Association of Poison Control Centers (AAPCC) Toxic Exposure
Surveillance System from 1990 to 1998 was performed. RESULTS: Of 810 potentially
toxic exposures to PIC, 55.9% occurred in females, 43.8% in males; in 0.3%,
gender was unknown. The majority of exposures (74.4%) involved children under six
years of age. The reasons for exposure were: 86.7% unintentional, 11.6%
intentional, and 1.6% adverse reaction. The most frequently reported clinical
effects attributed to PIC were vomiting (n = 23), diarrhea (10), nausea (11),
abdominal pain (10), and lethargy/drowsiness (7). While the majority of exposures
were managed outside a healthcare facility, management site varied depending on
age (management in non-healthcare facility in 71.8% of exposures in children
under six years of age vs. 44.9% in adolescents and adults). The majority of
outcomes (95.6%) were no effect, minor effect, unrelated effect, not followed
since nontoxic, or not followed since only minimal toxicity possible. Of two
cases coded as moderate effect, it could not be determined whether the symptoms
were related to PIC in one, and in the second case inspection of the poison
center record revealed that the actual outcome was minor effect. There were no
major effects or deaths. CONCLUSIONS: There were no serious adverse events
following PIC exposure reported to the AAPCC. Although more data are needed,
these findings suggest reduced toxicity for PIC relative to other forms of iron.
PMID- 10676824
TI - Criteria for assessing the appropriateness of patient counseling in community
pharmacies.
AB - OBJECTIVE: To develop valid, reliable criteria for assessing the appropriateness
of the management of common ailments and nonprescription drug therapy in
community pharmacies in the UK. METHODS: The criteria were developed by an expert
panel using the nominal group technique. The validity of the criteria was tested
by surveying a random sample of pharmacists who were asked to rate the importance
of each criterion on a semantic differential scale from 1 (low) to 7 (high).
Subsequently, the reliability of the criteria was assessed: a random sample of
pharmacists were each asked to apply the criteria to four vignettes of patient
counseling on two separate occasions. RESULTS: All assessment criteria exceeded
our predefined level of face, content, and consensual validity. In reliability
testing, the overall assessment of appropriateness, along with five component
assessment criteria, surpassed our predefined level of reliability. Three
criteria, however, did not meet our predefined standard. These criteria were
rational content of advice, rational product choice, and referral to another
health professional. CONCLUSIONS: This represents the first systematic attempt to
develop an instrument of general applicability for assessing the appropriateness
of patient counseling and to subject it to rigorous validity and reliability
testing. We suggest that further work is required to refine the criteria that did
not meet reliability standards and to understand the decision-making processes
underlying the assessment of vignettes of patient counseling.
PMID- 10676825
TI - Syndrome of inappropriate antidiuretic hormone secretion associated with
lisinopril.
AB - OBJECTIVE: To describe a case of the syndrome of inappropriate antidiuretic
hormone secretion (SIADH) associated with lisinopril therapy. CASE SUMMARY: A 76
year-old white woman who was being treated with lisinopril and metoprolol for
hypertension presented with headaches accompanied by nausea and a tingling
sensation in her arms. Her serum sodium was 109 mEq/L, with a serum osmolality of
225 mOsm/kg, urine osmolality of 414 mOsm/kg, and spot urine sodium of 122 mEq/L.
Diclofenac 75 mg qd for osteoarthritic pain and lisinopril 10 mg qd for
hypertension was begun in 1990. Lisinopril was increased to 20 mg qd in August
1994 and to 20 mg bid pm in August 1996 for increasing blood pressure; metoprolol
50 mg qd was added in July 1996. A diagnosis of SIADH was postulated and further
evaluation was undertaken to exclude thyroid and adrenal causes. After lisinopril
was discontinued and the patient restricted to 1000 mL/d of fluid, serum sodium
gradually corrected to 143 mEq/L. The patient was discharged taking metoprolol
alone for her hypertension; serum sodium has remained > or =138 mEq/L through
April 1999, 32 months after discharge, despite daily use of diclofenac.
DISCUSSION: Angiotensin-converting enzyme (ACE) inhibitors in antihypertensive
doses may block conversion of angiotensin I to angiotensin II in the peripheral
circulation, but not in the brain. Increased circulating angiotensin I enters the
brain and is converted to angiotensin II, which may stimulate thirst and release
of antidiuretic hormone from the hypothalamus, eventually leading to
hyponatremia. CONCLUSIONS: SIADH should be considered a rare, but possible,
complication of therapy with lisinopril and other ACE inhibitors.
PMID- 10676826
TI - Malignant primary hypertension in pregnancy treated with lisinopril.
AB - OBJECTIVE: To report a case of a patient treated with an angiotensin-converting
enzyme (ACE) inhibitor with a good neonatal outcome. CASE REPORT: A 39-year-old
African-Caribbean patient who had chronic hypertension presented at 18 weeks'
gestation with acute hypertension. She was being treated for chronic hypertension
with lisinopril, but had self-discontinued treatment. Attempts to control her
hypertension with labetolol, nifedipine, and methyldopa were ineffective. She was
therefore offered termination of pregnancy so treatment with lisinopril could be
restarted. The patient elected to continue with the pregnancy in spite of the
fetal risks associated with the use of an ACE inhibitor. She was delivered of a
girl at 26 weeks' gestation. The baby initially had renal failure and also
developed acute necrotizing enterocolitis. The renal failure improved
simultaneously with the latter complication, and it is postulated that there was
enteric excretion of lisinopril. The baby was discharged home on day 102 with no
further complications. DISCUSSION: ACE inhibitors are acceptable medications to
use in the first trimester of pregnancy; however, fetal malformations and
neonatal complications have been associated with their use later in pregnancy,
and they have a perinatal mortality rate of 97/1000. Lisinopril is excreted in
urine and feces unchanged, and its half-life is prolonged in anuric neonates.
Peritoneal dialysis eliminates lisinopril; however, this neonate improved after
treatment for necrotizing enterocolitis and simultaneous improvement in bowel
function. CONCLUSIONS: ACE inhibitors should not be used in pregnancy beyond the
end of the first trimester. In exceptional cases, they may be indicated for the
control of severe hypertension when the patient is refractory to other
medications. The patient should be fully counseled about the adverse effect
profile and neonatal outcome. This case report documents a successful outcome for
mother and baby in these circumstances.
PMID- 10676827
TI - Elevated free fractions of valproic acid in a heart transplant patient with
hypoalbuminemia.
AB - OBJECTIVE: To report a case demonstrating the importance of monitoring unbound
valproic acid (VPA) serum concentrations in a patient with hypoalbuminemia. CASE
SUMMARY: A 53-year-old white woman status-post heart transplantation was admitted
to the hospital for declining cardiac function, possible rejection, and increased
lethargy requiring intubation. An extensive workup of the patient's profound
lethargy was initiated, including an evaluation of her VPA regimen. Initially,
VPA dosages were adjusted based on the total serum concentration of VPA.
Hypoalbuminemia compounded with increased lethargy prompted the measurement of
unbound serum concentrations of VPA. The VPA dosage was then adjusted based on
the unbound rather than the total VPA serum concentration; the patient eventually
improved and was discharged from the hospital. DISCUSSION: Lethargy is a
concentration-related adverse effect of VPA. The nonlinear pharmacokinetic and
protein saturation characteristics of VPA may result in nonproportional
elevations in unbound drug, and subsequent increases in adverse effects, when
dosage adjustments are based solely on measurement of total VPA serum
concentrations in patients with hypoalbuminemia. CONCLUSIONS: This case report
suggests that appropriate monitoring of unbound drug concentrations of VPA may
prevent unrecognized concentration-related adverse effects. Awareness of the
pharmacokinetic relationship and adverse effects of VPA will aid clinicians in
identifying the etiology of symptoms.
PMID- 10676828
TI - Tamsulosin for the treatment of benign prostatic hypertrophy.
AB - OBJECTIVE: To review the information necessary to assess the efficacy and safety
of tamsulosin compared with other adrenergic antagonists for treatment of
symptomatic benign prostatic hyperplasia. DATA SOURCES: A search was conducted of
Cumulated Index Medicus, January 1993-August 1999, which was restricted to human
trials and English-language journals. STUDY SELECTION AND DATA EXTRACTION:
Efficacy studies were included if the design was randomized and included a
control group. Drug safety was assessed using data from any patient series or
controlled study. DATA SYNTHESIS: Tamsulosin, a uroselective alpha1A-adrenergic
receptor antagonist, relaxes smooth muscle in the prostate and bladder neck,
thereby enhancing bladder emptying. In randomized, controlled clinical trials
using standardized instruments, tamsulosin improves obstructive voiding symptoms
by at least 25% in 65-80% of patients with symptomatic benign prostatic
hyperplasia. Tamsulosin also improves peak urinary flow rate by 1.4-3.6 mL/sec in
various studies and reduces post-void residual urine volume. The usual dosage of
tamsulosin was 0.4 or 0.8 mg orally once a day in the studies performed in the US
and Europe; daily doses of 0.1-0.4 mg were used in studies performed in Japan.
The beneficial effects of tamsulosin on voiding symptoms, peak urinary flow rate,
and bladder emptying appear to be dose-related, up to a ceiling dose of 0.4 mg.
The most common adverse effects are headache, asthenia, dizziness, and rhinitis
like complaints. Retrograde or delayed ejaculation occurs in 4.5-14.0% of
patients and has required discontinuation of treatment in a minority of these
patients. At the usual dose of 0.4-0.8 mg/d, tamsulosin does not appear to
significantly reduce blood pressure, increase heart rate, or cause first-dose
syncope; therefore, dosage titration is not necessary when initiating treatment.
Use of nifedipine, enalapril, atenolol, furosemide, or digoxin does not require
dosage modification when tamsulosin is initiated concomitantly; hypotension has
not been reported with combined use of tamsulosin and these commonly used agents.
CONCLUSIONS: Tamsulosin is an improvement over other alpha-adrenergic antagonists
for the management of symptoms of benign prostatic hyperplasia. It is a more
convenient alternative that does not require initial dosage titration, has a fast
onset of action, and has a low potential to cause hypotension when used alone or
in combination with commonly used antihypertensive agents. It is more costly than
some of the other second-generation alpha-adrenergic antagonists.
PMID- 10676829
TI - Switching antipsychotic therapies.
AB - BACKGROUND: Atypical antipsychotics are superior to conventional antipsychotics
in improving positive and negative psychotic symptoms. Atypical antipsychotics do
not exacerbate mood symptoms, and may improve mood symptoms and cognitive
functioning; additionally, they have better adverse effect profiles than
conventional antipsychotics. OBJECTIVE: To review the benefits of switching
patients with schizophrenia or schizoaffective disorder from a conventional to an
atypical antipsychotic, or from one atypical antipsychotic to another. In spite
of the higher acquisition cost of atypical antipsychotics, overall treatment
costs may decrease due to lower relapse and hospitalization rates. DATA SOURCES:
A MEDLINE search (January 1977-January 1999) was conducted for articles written
in English about efficacy, adverse effects, compliance, and pharmacoeconomics for
atypical and conventional antipsychotics. STUDY SELECTION: Large, multicenter,
double-blind, controlled studies were used for efficacy, safety, tolerability,
and pharmaco-economic data. Where appropriate, recent review articles were also
used. RESULTS: Atypical antipsychotics are superior to conventional
antipsychotics in the treatment of schizophrenia. Atypical and conventional
antipsychotics have different adverse effect profiles, costs, and compliance
rates. CONCLUSIONS: Some patients may benefit by switching from a conventional to
an atypical antipsychotic, from an atypical to a conventional antipsychotic, or
from one atypical antipsychotic to another. Methods of switching antipsychotic
therapies include tapering and cross-over strategies.
PMID- 10676830
TI - Newer antithrombotic strategies in the initial management of non-ST-segment
elevation acute coronary syndromes.
AB - OBJECTIVE: To review the place in therapy of currently available antithrombotic
agents in the non-ST-segment elevation acute coronary syndromes, that is,
unstable angina and non-Q-wave myocardial infarction (MI). Recommendations are
made based on currently available data. DATA SOURCE: English-language clinical
studies, position statements, and review articles pertaining to the management of
unstable angina and non-Q-wave MI with currently available products. STUDY
SELECTION: Selection of prospective clinical studies was limited to those
focusing on the management of the non-ST-segment elevation acute coronary
syndromes, unstable angina, and non-Q-wave MI. DATA SYNTHESIS: It has yet to be
determined which combination of agents (dalteparin, enoxaparin, lepirudin,
clopidogrel, ticlopidine, abciximab, eptifibatide, tirofiban) and procedural
strategies most significantly reduces mortality and serious events in these
patients. The relevant pathophysiology, diagnostic criteria, and risk-stratifying
procedures are reviewed in context with information from clinical studies
regarding currently available agents for the management of non-ST-segment
elevation acute coronary syndromes. CONCLUSIONS: A large number of new
therapeutic classes and agents are available for the treatment of unstable angina
and non-Q-wave MI. Although the diagnoses of unstable angina or non-Q-wave MI
identify risk, treatment decisions are often based on the presence or absence of
ST-segment elevations. Limited prospective evidence delineates the proper
utilization of resources to best manage these patients. Efforts should be aimed
at identifying particular patients who will best benefit from recently available
therapies.
PMID- 10676831
TI - Immunology of Varicella Immunization in the elderly.
AB - OBJECTIVE: To review the varicella-zoster virus (VZV) and herpes zoster disease
and to summarize published reports on the use of the live-attenuated varicella
zoster vaccine to enhance cell-mediated immunity in elderly individuals. DATA
SOURCE: A MEDLINE search (1966-August 1999) for English-language clinical studies
and review articles pertaining to VZV and the live-attenuated varicella vaccine
was conducted; references obtained from these publications were subsequently
reviewed for additional relevant articles. STUDY SELECTION AND DATA EXTRACTION:
Representative clinical trials were summarized and relevant information was
selected to assist in the understanding of VZV, the subsequent immune response,
and the live-attenuated varicella vaccine. DATA SYNTHESIS: The physiologic, age
related decline in VZV cell-mediated immunity has been shown to be restored on
administration of live-attenuated varicella vaccine. Various studies report serum
anti-VZV antibody concentrations, and production of interferon-gamma were
increased following vaccination. Concentrations subsequently returned to baseline
one year after vaccination. Increase in responder cell frequency, a measure of
cell-mediated immunity, has been reported to last up to four years after
vaccination, at concentrations similar or superior to those observed following
herpes zoster. CONCLUSIONS: Enhancement of cell-mediated immune response in
elderly individuals through vaccination with live-attenuated varicella vaccine is
a possible measure to protect this population from herpes zoster and to attenuate
its complications. A summary of immunogenicity studies to identify the immune
response to live-attenuated varicella vaccine in the elderly is presented. The
absolute clinical significance, as well as appropriate administration guidelines
of this prophylactic intervention, will become evident following forthcoming
large, masked, placebo-controlled trials.
PMID- 10676832
TI - Anterior ocular infections: an overview of pathophysiology and treatment.
AB - OBJECTIVE: To provide a review of the pathophysiology and treatment of anterior
ocular infections. DATA SOURCE: A MEDLINE search (from 1970 to October 1998) as
well as a review of the tertiary literature was performed to identify pertinent
literature on pathophysiology and treatment of ocular infections. STUDY SELECTION
AND DATA EXTRACTION: All articles were considered for possible inclusion in the
review. Relevant studies were selected for discussion in the article. DATA
SYNTHESIS: Ocular infections are common and vary from self-limiting to sight
threatening. Infections occur in different eye structures; presentation and
treatment vary accordingly. Infections can occur when tissues of the eye are
exposed to pathogens not normally present, when the eye is damaged, allowing
pathogens to overcome the natural defenses of the eye, or in immunosuppressed
patients where normal flora may become opportunistic. In deciding on appropriate
treatment, both the causative pathogen and the structure(s) affected must be
considered. The most likely pathogen can often be determined based on clinical
signs and symptoms, patient history, or, in some cases, may need to be determined
microbiologically. Differences in drug absorption, penetration, and availability
to the various structures of the eye affect treatment decisions. Severity of
infection, efficacy and safety of medication, and cost/benefit ratios must be
taken into consideration in choosing the proper pharmacologic management of
various ocular infections. CONCLUSIONS: Treatment of ocular infections depends on
knowledge of the pathophysiology and drug disposition at the site of infection.
An understanding of the current concepts surrounding the management of the
anterior ocular infections presented will aid in the provision of optimal patient
care.
PMID- 10676833
TI - Management protocol for abacavir-related hypersensitivity reaction.
AB - OBJECTIVE: To develop an abacavir hypersensitivity reaction management protocol
for the University of Oklahoma Health Sciences Center. DATA SYNTHESIS: Conference
abstracts, published literature, and manufacturer-provided materials were
reviewed to define the syndrome and manifestations and to recommend steps to take
when a patient develops abacavir-related reactions. RESULTS: Initial education,
formalized contact and response mechanism, and intervention levels were
incorporated into a protocol for clinicians. CONCLUSIONS: Abacavir, a newly
approved agent for the treatment of HIV, has been associated with a fatal
hypersensitivity reaction. Our protocol provides a mechanism to minimize
progression of abacavir hypersensitivity reaction by providing a formalized
management procedure.
PMID- 10676834
TI - The role of vasopressin in the treatment of vasodilation in shock states.
AB - OBJECTIVE: To review the role of vasopressin in the treatment of vasodilatory
shock. DATA SOURCES: A MEDLINE search on published reports (1966-April 1999) was
conducted. STUDY SELECTION: English-language studies and case reports were
selected and evaluated based on quality of review of vasopressin in the treatment
of vasodilatory shock. DATA SYNTHESIS: In patients with end-stage vasodilatory
shock, baroreceptor reflex is impaired and vasopressin stores are depleted.
Persistent elevation of catecholamines may lead to down-regulation of beta
adrenergic receptors and reduces smooth-muscle response to catecholamines,
leading to inability of maintaining organ perfusion. Small-scale studies and case
reports have demonstrated vasopressin's efficacy in maintaining blood pressure in
patients with septic shock, cardiac arrest, and end-stage heart failure,
refractory to other vasopressor therapies. CONCLUSIONS: Vasopressin may be a
reasonable alternative for patients in vasodilatory shock. However, larger-scale
controlled dinical trials are warranted before its routine use can be
recommended.
PMID- 10676835
TI - Do ethanol and metronidazole interact to produce a disulfiram-like reaction?
AB - OBJECTIVE: To obtain and evaluate evidence about the supposed disulfiram-like
interaction between metronidazole and ethanol. DATA SOURCES: MEDLINE search from
January 1964 to June 1999, using the terms metronidazole, ethanol, and drug
reaction. DATA SYNTHESIS: The manufacturer's warnings include a disulfiram-like
reaction between metronidazole and ethanol. However, review of reports published
between 1969 and 1982 produced no convincing evidence that this reaction exists.
Six case reports involving eight patients were evaluated. CONCLUSIONS: Four of
the eight cases were serious, including one death, but the authors of all the
reports presumed the metronidazole-ethanol reaction to be an established
pharmacologic fact. None provided evidence that could justify their conclusions.
PMID- 10676836
TI - Lamotrigine for the treatment of bipolar disorder.
AB - OBJECTIVE: To describe the available data regarding the clinical efficacy of
lamotrigine for the treatment of bipolar disorder. SUMMARY: Anticonvulsants have
emerged as alternative mood-stabilizing agents for patients with bipolar disorder
who do not respond to lithium. Data regarding the efficacy of lamotrigine have
been generated primarily from case reports, small open trials, and one large,
randomized, placebo-controlled trial. These reports suggest that lamotrigine may
be effective for the management of bipolar disorder. CONCLUSIONS: Although
current data are limited, treatment-refractory patients with bipolar disorder may
benefit from lamotrigine therapy. Several studies are currently underway to
determine the appropriate role of lamotrigine in the treatment of bipolar
disorder.
PMID- 10676837
TI - Fever, rash, and pancytopenia following vancomycin rechallenge in the presence of
ceftazidime.
PMID- 10676838
TI - Osteomalacia associated with carbamazepine/valproate.
PMID- 10676839
TI - Psychotropic medication use in older patients referred for evaluation of falls
risk.
PMID- 10676840
TI - de Clerambault syndrome successfully treated with olanzapine.
PMID- 10676841
TI - Withdrawal-emergent dyskinesia in a patient taking risperidone/citalopram.
PMID- 10676842
TI - The p38 signal transduction pathway: activation and function.
AB - The p38 signalling transduction pathway, a Mitogen-activated protein (MAP) kinase
pathway, plays an essential role in regulating many cellular processes including
inflammation, cell differentiation, cell growth and death. Activation of p38
often through extracellular stimuli such as bacterial pathogens and cytokines,
mediates signal transduction into the nucleus to turn on the responsive genes.
p38 also transduces signals to other cellular components to execute different
cellular responses. In this review, we summarize the characteristics of the major
components of the p38 signalling transduction pathway and highlight the targets
of this pathway and the physiological function of the p38 activation.
PMID- 10676843
TI - Induction of protein kinase Czeta-related protein kinase by growth suppression in
carcinogen-initiated epidermal cell-line WYF31 cells.
AB - In primary cultured mouse epidermal cells, protein kinase C isozyme zeta
(PKCzeta) consists of multiple forms, for example, low-salt eluted PKCzeta (1
PKCzeta; 79 and 85 kDa) and high-salt eluted PKCzeta (h-PKCzeta; 79 and 85 kDa)
on anion-exchange column chromatography. In this study, biochemical and
biophysical differences between 1-PKCzeta and h-PKCzeta were examined by using
carcinogen-initiated mouse epidermal cell-line WYF31 cells, whose growth is
stimulated by tumour promoter phorbol 12-myristate 13-acetate (PMA). The binding
efficiency of h-PKCzeta to anti-PKCzeta antibody-affinity column was 10 times
higher than that of 1-PKCzeta. T7-tagged rat PKCzeta overexpressed in WYF31 cells
was recovered only in the high-salt eluted area on the anion-exchange column.
Furthermore, when rat PKCzeta was stably overexpressed in WYF31 cells, the
content of h-PKCzeta increased 4 to 5 times compared to that of parental cells,
but the content of 1-PKCzeta was not altered. All of these results indicate that
h-PKCzeta is the product of the PKCzeta gene (referred to as PKCzeta) and that 1
PKCzeta is closely related but different from PKCzeta (referred to as PKCzeta
related kinase). Interestingly, serum starvation of WYF31 cells caused a marked
increase of the content of PKCzeta-related kinase with a concomitant decrease of
PKCzeta content. These changes were reversed by stimulating the cell growth with
10% foetal calf serum. Prolonged treatment of starved cells with PMA, which
induces the proliferation of WYF31 cells, also caused the downregulation of
PKCzeta-related kinase. These results suggest that the expression levels of
PKCzeta-related kinase and PKCzeta are differently regulated, and that the
increased expression of PKCzeta-related kinase might play a significant role in
the growth-suppression processes of WYF31 cells.
PMID- 10676844
TI - Activation of STAT5 during EPO-directed suppression of apoptosis.
AB - The ligand-dependent activation of the JAK/STAT (Januskinase/Signal Transducer
and Activator of Transcription) pathway has been implicated in the explanation of
cytokine-specific regulation of gene expression. Previous studies have reported
conflicting results on the role of the transcription factor STAT5 in
erythropoietin (EPO)-induced cellular responses. In this study we focused on the
functional importance of STAT5 docking sites in the intracellular EPO receptor
(EPOR) domain for the mediation of antiapoptotic activities. We demonstrate that
EPO-dependent survival of erythroleukemic cell lines is accompanied by sustained
STAT5 DNA-binding activity. The role of single tyrosine residues was dissected by
the analysis of myeloid FDCP-1 cells stably expressing mutant EPOR proteins. The
data show that receptors having a high potential to mediate antiapoptotic signals
also effectively activate STAT5, whereas receptors lacking STAT5 docking sites
are diminished in both activities. We conclude that the transcription factor
STAT5 is functionally implicated in the EPO-dependent survival of cells.
PMID- 10676845
TI - Caffeine exerts a dual effect on capacitative calcium entry in Xenopus oocytes.
AB - Caffeine increases the amplitude of the Cl- currents evoked by capacitative Ca2+
entry (CCE) on thapsigargin-treated Xenopus oocytes. The caffeine-induced
potentiation of the CCE process appears to rest on two distinct and additive
components. The first component involves the cAMP second messenger system since
it can be mimicked by either IBMX perfusion or cAMP microinjection into the
oocyte and inhibited by the PKA inhibitory peptide i-PKA. The second component,
although activatory, is dynamically related to the caffeine-evoked inhibition of
InsP3-mediated Ca+ release and may arise from an interaction between caffeine and
the InsP3 receptor in the context of a conformational coupling between the InsP,
receptor and the channels responsible for CCE.
PMID- 10676846
TI - Altered activation of phospholipase D by lysophosphatidic acid and endothelin-1
in mouse embryo fibroblasts lacking phospholipase C-gamma1.
AB - Lysophosphatidic acid (LPA) and endothelin-1 (ET-1) activate phospholipase D
(PLD) in many cell types. To see if phospholipase C-gamma1 plays a role, we used
embryonic fibroblasts from mice in which the PLCgamma1 gene was disrupted.
Surprisingly, the effect of LPA on inositol phosphate accumulation was increased
in these PLCgamma1-/- cells, whereas that of ET-1 was completely abrogated. When
PLD activity was measured, the response to LPA was also enhanced and the response
to ET-1 lost in the PLCgamma1-/- cells. Treatment of these cells with ionomycin
and oleoyl acetyl glycerol to mimic PLC stimulation restored PLD activity.
Treatment of either PLCgamma1+/+ and PLCgamma1-/- cells with tyrosine kinase
inhibitors did not inhibit LPA- or ET-1-induced PLD activity. Moreover, LPA and
ET-1 treatment of PLCgamma1+/+ and PLCgamma1-/- cells did not cause tyrosine
phosphorylation of PLC-gamma1 or PLC-gamma2. In summary, these results show that
the altered PLD responses to LPA and ET-1 in PLCgamma1-/- are due to changes in
PLC activity and do not involve tyrosine kinase activity.
PMID- 10676847
TI - Acute modulation of Ca2+ influx on rat heart by 17beta-estradiol.
AB - Estrogens initiate their action by binding to specific intracellular receptors
and then acting on gene expression. In addition, there is growing evidence of a
direct membrane effect via interaction with a cell surphase receptor. The aim of
the present study was to investigate the acute effects of 17beta-estradiol on
Ca2+ fluxes through second messenger pathways in rat cardiac muscle. Exposure of
rat ventricle to low levels of 17beta-estradiol (10(-12)-10(-8) M) increased
45Ca2+ influx within 1 min (+38%); the response was biphasic, peaking at 2 and 5
min (+60 and +55%, respectively). The effect of the hormone on rat heart seems to
be specific since 17alpha-estradiol, dihydrotestosterone, and progesterone were
devoid of activity. The effect of 17beta-estradiol (5 min, 10(-10) M) was
suppressed by nitrendipine (1 microM) and LaCl3 (10 microM), involving the
activation of voltage-dependent Ca2+ channels in the acute increase of rat heart
calcium influx by the hormone. 17Beta-estradiol rapidly increased cAMP content
and PKA activity of rat cardiac muscle in parallel to the changes in Ca2+ uptake.
In addition the cAMP antagonist Rp-cAMPS suppressed 17beta-estradiol-dependent
Ca2+ influx. Altogether, the data suggest the involvement of the cAMP/PKA
messenger system in the nongenomic modulation of Ca2+ influx in rat cardiac
muscle by physiological levels of 17beta-estradiol.
PMID- 10676848
TI - Divergent proliferative responses to a gastrin receptor ligand in synchronized
and unsynchronized rat pancreatic AR42J tumour cells.
AB - Depending upon experimental model, the CCK-B/gastrin receptor ligand CI-988
exhibits either agonist or antagonist activity. To confirm that CI-988 behaves as
an antagonist toward gastrin-stimulated growth, its effects on cell proliferation
were investigated in unsynchronized and synchronized AR42J rat pancreatic tumour
cells. In unsynchronized cultures CI-988 alone had no effect, but inhibited
gastrin-stimulated cell proliferation. In contrast, in synchronized cultures, CI
988 stimulated cell proliferation. Similarly, CI-988 inhibited gastrin-stimulated
cAMP production in unsynchronized cells, but stimulated cAMP formation in
synchronized cultures. Therefore, CI-988 stimulation of cAMP production and
proliferation in AR42J cell cultures appears to be cell cycle-dependent. CI-988
inhibited gastrin-stimulated intracellular calcium ([Ca2+]i) mobilization in both
populations and thus acted as an antagonist toward this pathway. Because CCK
receptor densities and affinities were similar in both cell populations, the data
suggest that CI-988's divergent effects on cell proliferation are governed by
postreceptor signalling events which vary with cell cycle.
PMID- 10676849
TI - Involvement of phosphorylation of beta-subunit in cAMP-dependent activation of L
type Ca2+ channel in aortic smooth muscle-derived A7r5 cells.
AB - We investigated the effect of intracellular cAMP on the gating kinetics of L-type
Ca2+ channel in an A7r5 smooth muscle-derived cell line using the whole-cell
patch-clamp technique. Application of dibutyryl cyclic AMP (db-cAMP) to the cell
increased the magnitude of Ca2+ currents through L-type Ca2+ channels (I(Ca)),
and shifted the current-voltage relationship (I-V curve) for I(Ca) to the left.
The magnitudes of maximum I(Ca) were 14.1 +/- 0.7 before and 16.0 +/- 1.1 pA/pF
after application of 1 mM db-cAMP (P < 0.05). The values of the half-activation
potential (V(1/2)) of I(Ca), estimated from activation curves, were -7.0 +/- 0.8
mV before and -10.8 +/- 1.0 mV after application of db-cAMP (P < 0.05). In cells
pretreated with 10 microM Rp-cAMPS (a specific inhibitor of PKA), db-cAMP
affected neither the I-V curve nor the activation curve for I(Ca). In cells
pretreated with the antisense oligonucleotide for the beta-subunit of L-type Ca2+
channel, db-cAMP failed to enhance I(Ca) or alter the activation curve. On the
other hand, in the cells pretreated with the nonsense oligonucleotide,
application of db-cAMP caused an increase in magnitude of I(Ca) and shifted the
activation curve to the left. Western blot analysis revealed that the
pretreatment of cells with antisense oligonucleotide but nonsense oligonucleotide
reduced the expression of the beta-subunit of the L-type Ca2+ channel. We
conclude that the cAMP-dependent phosphorylation of the beta-subunit potentiates
the voltage dependency of the activation kinetics of the L-type Ca2+ channel in
A7r5 cells.
PMID- 10676850
TI - What the evolution of the amyloid protein precursor supergene family tells us
about its function.
AB - The Alzheimer's disease amyloid protein precursor (APP) gene is part of a multi
gene super-family from which sixteen homologous amyloid precursor-like proteins
(APLP) and APP species homologues have been isolated and characterised.
Comparison of exon structure (including the uncharacterised APL-1 gene),
construction of phylogenetic trees, and analysis of the protein sequence
alignment of known homologues of the APP super-family were performed to
reconstruct the evolution of the family and to assess the functional significance
of conserved protein sequences between homologues. This analysis supports an
adhesion function for all members of the APP super family, with specificity
determined by those sequences which are not conserved between APLP lineages, and
provides evidence for an increasingly complex APP superfamily during evolution.
The analysis also suggests that Drosophila APPL and Caenorhabditis elegans APL-1
may be a fourth APLP lineage indicating that these proteins, while not functional
homologues of human APP, are similarly likely to regulate cell adhesion.
Furthermore, the betaA4 sequence is highly conserved only in APP orthologues,
strongly suggesting this sequence is of significant functional importance in this
lineage.
PMID- 10676851
TI - In-vivo glutathione elevation protects against hydroxyl free radical-induced
protein oxidation in rat brain.
AB - Glutathione deficiency has been associated with a number of neurodegenerative
diseases including Lou Gehrig's disease, Parkinson's disease, and HIV. A crucial
role for glutathione is as a free radical scavenger. Alzheimer's disease (AD)
brain is characterized by oxidative stress, manifested by protein oxidation,
lipid oxidation, oxidized glutathione, and decreased activity of glutathione S
transferase, among others. Reasoning that elevated levels of endogenous
glutathione would offer protection against free radical-induced oxidative stress,
rodents were given in vivo injections of N-acetylcysteine (NAC), a known
precursor of glutathione, to study the vulnerability of isolated synaptosomal
membranes treated with Fe2+/H2O2, a known hydroxyl free radical producer. Protein
carbonyls, a marker of protein oxidation, were measured. NAC significantly
increased endogenous glutathione levels in cortical synaptosome cytosol (P <
0.01). As reported previously, protein carbonyl levels of the Fe2+/H2O2-treated
synaptosomes were significantly higher compared to that of non-treated controls
(P < 0.01), consistent with increased oxidative stress. In contrast, protein
carbonyl levels in Fe2+/H2O2-treated synaptosomes isolated from NAC-injected
animals were not significantly different from saline-injected non-treated
controls, demonstrating protection against hydroxyl radical induced oxidative
stress. These results are consistent with the notion that methods to increase
endogenous glutathione levels in neurodegenerative diseases associated with
oxidative stress, including AD, may be promising.
PMID- 10676852
TI - Analgesic effect of interferon-alpha via mu opioid receptor in the rat.
AB - Using the tail-flick induced by electro-stimulation as a pain marker, it was
found that pain threshold (PT) was significantly increased after injecting
interferon-alpha (IFN alpha) into the lateral ventricle of rats. This effect was
dosage-dependent and abolished by monoclonal antibody (McAb) to IFN alpha.
Naloxone could inhibit the analgesic effect of IFN alpha, suggesting that the
analgesic effect of IFN alpha be related to the opioid receptors. Beta
funaltrexamine (beta-FNA), the mu specific receptor antagonist could completely
block the analgesic effect of IFN alpha. The selective delta-opioid receptor
antagonist, ICI174,864 and the kappa-opioid receptor antagonist, nor-BNI both
failed to prevent the analgesic effect of IFN alpha. IFN alpha could
significantly inhibit the production of the cAMP stimulated by forskolin in SK-N
SH cells expressing the mu-opioid receptor, not in NG108-15 cells expressing the
delta-opioid receptor uniformly. The results obtained provide further evidence
for opioid activity of IFN alpha and suggest that this effect is mediated by
central opioid receptors of the mu subtype. The evidence is consistent with the
hypothesis that multiple actions of cytokines, such as immunoregulatory and
neuroregulatory effects, might be mediated by distinct domains of cytokines
interacting with different receptors.
PMID- 10676853
TI - Serotonin transporter function is modulated by brain-derived neurotrophic factor
(BDNF) but not nerve growth factor (NGF).
AB - The serotonin transporter (5-HTT) regulates serotonergic neurotransmission by
determining the magnitude and duration of serotonergic responses. We have
recently described a polymorphism in the 5-HTT gene promoter (5-HTTLPR) which
influences the function of the 5-HTT and is associated with several psychiatric
disorders. Immortalized B lymphocytes express the 5-HTT, and a B lymphocyte line
has been shown to express the receptor for brain-derived neurotrophic factor,
trkB. Since brain-derived neurotrophic factor (BDNF) is a specific growth and
differentiation factor for serotonergic neurons, we assessed whether BDNF is able
to modulate 5-HTT function in B lymphoblasts. Nerve growth factor (NGF), another
neurotrophin which acts via the trkA receptor, was also studied. Eight
immortalized B lymphoblast lines were generated and genotyped for the 5-HTTLPR.
After treatment with BDNF or NGF, 5-HT uptake and proliferation of the cell lines
were assessed. Two of the B cell lines showed a dose-dependent reduction of 5-HT
uptake after exposure to BDNF. Both of these cell lines were homozygous for the
long allele of the 5-HTTLPR. NGF did not influence 5-HT uptake or cellular
proliferation in any of the cell lines. Thus, BDNF but not NGF may influence 5-HT
uptake in some B lymphocytes. The fact that regulation of the 5-HTT was observed
preferentially in cells of the long/long genotype indicates that presence of a
short allele confers reduced regulatory capacity on the 5-HTT. In conclusion, B
lymphoblasts represent a practical model for functional regulation of the 5-HTT
by neurotrophins in serotonergic neurons.
PMID- 10676854
TI - Stimulation of Na+,K+-ATPase activity, increase in potassium uptake, and enhanced
production of ouabain-like compounds in ammonia-treated mouse astrocytes.
AB - Active potassium (K+) uptake and Na+,K+-ATPase activity were measured in primary
cultures of mouse astrocytes. Both parameters were virtually unaffected by acute
ammonia treatment but increased after chronic exposure to pathophysiologically
relevant concentrations of ammonia (0.3 or 3 mM) for 1-4 days. The increased
Na+,K+-ATPase activity after chronic treatment with ammonia was further enhanced
in the acute presence of 12 mM K+. Based on these observations and literature
data it was hypothesized that the direct effect of ammonia is formation of easily
diffusible compound(s) with ouabain-like effect, that upregulation occurs of
Na+,K+-ATPase activity and K+ uptake in response to the resulting ATPase
inhibition, and that the washing procedure preceding the uptake experiments and
the determination of Na+,K+-ATPase activity unmasks the upregulation. To test
this hypothesis, the content of compounds with ouabain-like action was measured
in media in which astrocytes had been incubated in the presence of 3 mM ammonia
for 4 days and in controls to which an additional 3 mM NaCl had been added
instead of ammonia. An endogenous, compound with ouabain-like activity was
demonstrated both under control conditions and in the ammonia-treated cultures,
and the content of this compound was increased by 50% in the ammonia-treated
cultures. Preliminary experiments showed that at least part of the released
ouabain-like compounds cross-react with authentic ouabain.
PMID- 10676855
TI - Melatonin inhibits pituitary adenylyl cyclase-activating polypeptide-induced
increase of cyclic AMP accumulation and [Ca2+]i in cultured cells of neonatal rat
pituitary.
AB - The effects of melatonin on pituitary adenylyl cyclase-activating polypeptide
induced increase of cyclic AMP and [Ca2+]i were studied in neonatal rat pituitary
cells. The polypeptide increased cyclic AMP accumulation. In the presence of
melatonin the increase of cyclic AMP was inhibited in a dose-dependent manner,
the maximal inhibition was achieved with 1-10 nM melatonin. Pituitary adenylyl
cyclase-activating polypeptide also increased [Ca2+]i in 30% of the pituitary
cells and melatonin inhibited the effect. Most of the cells sensitive to adenylyl
cyclase-activating polypeptide (77%) were also sensitive to GnRH, suggesting they
are gonadotrophs. The remaining cells were not identified. The polypeptide
induced [Ca2+]i increase was inhibited in Ca2+-free medium in 2/3 of the cells
indicating that Ca2+ influx was involved. To examine causal relationship between
cyclic AMP and [Ca2+]i increase, we have studied the effect of adenylyl cyclase
activation by forskolin on intracellular Ca2+ concentration. Forskolin had
similar effects as adenylyl cyclase-activating polypeptide: it increased [Ca2+]i
in the pituitary cells and the increase was dependent on presence of Ca2+ in the
medium. Melatonin inhibited the forskolin induced [Ca2+]i increase. Our
observations indicate that increase of cyclic AMP stimulates Ca2+ influx in the
pituitary cells of neonatal rat and that this mechanism is involved in [Ca2+]i
increase induced by the pituitary adenylyl cyclase-activating polypeptide.
Because melatonin inhibits increase of cyclic AMP induced by pituitary adenylyl
cyclase-activating polypeptide or forskolin, the inhibitory effect of melatonin
on Ca2+-influx may be mediated by the decrease of cyclic AMP concentration. This
mechanism of melatonin action has not been described previously. Because
melatonin inhibits the polypeptide- or forskolin-induced [Ca2+]i also in the
cells not sensitive to GnRH, melatonin receptors seem to be present on both
gonadotrophs and non-gonadotrophic pituitary cells.
PMID- 10676856
TI - Difference in glutamate release between retina and cerebral cortex following
ischemia.
AB - The difference in ischemic tolerance between the retina and cerebral cortex may
be attributable to a difference in glutamate release during ischemia. Glutamate
release in the retina and the cerebral cortex was compared in rats. A dialysis
electrode for real-time glutamate measurement was perfused with L-glutamate
oxidase, and the current evoked between two voltage-clamped electrodes was
detected. Two electrodes were implanted in the retina through the choroid and
cerebral cortex in 12 anesthetized rats, each mounted on a stereotaxic frame.
Global ischemia was induced by ligation on both carotid arteries and hypotension
was induced by blood withdrawal. Under control conditions, the glutamate
concentration in the retina was 164 +/- 231 (mean +/- standard deviation) microM,
being significantly higher (P < 0.05) than that in the cerebral cortex (83 +/-
105 microM). In 10 of the 12 animals, the glutamate concentration in the retina
decreased to a minimum of 134 +/- 149 microM (P < 0.01, compared with the value
for the cerebral cortex), but that in the cortex increased to 410 +/- 305 microM
(averaged highest value). Immediately after the start of reperfusion, the
glutamate concentration in the cortex decreased rapidly to 101 +/- 27 microM, but
that in the retina increased gradually to almost the control level (148 +/- 204
microM). In the other two animals, the glutamate concentration remained
unchanged. In conclusion, glutamate release in the retina does not proceed as
rapidly as that in the cerebral cortex during 20 min of ischemia, and in fact
decreases. This opposite trend shown by the two organs may be due to the slow
depletion rate of ATP in the retina. This may explain the differing neuronal
tolerance to ischemia in these two organs.
PMID- 10676857
TI - Lack of stereoselectivity of 8-hydroxy-2(di-N-propylamino)tetralin-mediated
inhibition of forskolin-stimulated adenylyl cyclase activity in human pre- and
post-synaptic brain regions.
AB - The stereoselectivity of the serotonin1A (5-HT1A) receptor compound 8-hydroxy
2(di-N-propylamino)tetralin (8-OH-DPAT) on forskolin-stimulated adenylyl cyclase
activity was investigated in membranes from human 5-HT pre-synaptic (raphe
nuclei) and post-synaptic (hippocampus and prefrontal cortex) regions of autopsy
brains. After sample incubation with agonists and antagonists, results showed
that both the racemic mixture of 8-OH-DPAT or its (+) and (-) enantiomers behaved
as full agonists in the tested brain regions. Enantiomer potency (EC50, nM) and
efficacy (percentage of maximal inhibition, %) values were similar in all regions
under investigation. However, some inter and intra-region variations in racemic 8
OH-DPAT potency and efficacy have been observed. In particular, the potency of
racemic 8-OH-DPAT was higher in the prefrontal cortex and raphe nuclei than in
the hippocampus, where it was in fact lower than either single enantiomers.
Agonist effects were competitively reversed by 5-HT1A antagonists, although once
again a different profile was revealed in the hippocampus. The data underscores
the lack of stereospecificity of 8-OH-DPAT-mediated inhibition of adenylyl
cyclase activity in either pre- or post-synaptic human brain regions. Moreover,
such results have significant implication, as they support the notion that human
5-HT1A receptors might vary from one brain region to the other.
PMID- 10676858
TI - Mitochondrial impairment and recovery after heat shock treatment in a human
microglial cell line.
AB - The application of a heat shock on the human microglial cell line (CHME 5) has
been shown to cause cytoskeleton modifications and alterations in phosphorylated
metabolite content (Macouillard-Poulletier de Gannes et al., 1998a Metabolic and
cellular characterization of immortalized human microglial cells under heat
stress. Neurochem. Int. 33, 61-73). In this study, we focused on the possible
involvement of mitochondria in this heat stress response. The cell respiratory
properties were followed during the recovering period and the possible
relationships between mitochondria and the cytoskeleton were studied. We observed
that the heat shock induced changes in mitochondrial activity due to protein
denaturation, rather than mitochondrial loss. Furthermore, these alterations were
correlated with cytoskeleton disorganization since vimentine, tubuline and
mitochondria shift, simultaneously, to a perinuclear location. The perturbations
of the mitochondrial distribution persisted until cytoskeleton networks had
recovered. Nevertheless, the respiratory properties recovered rapidly suggesting
a renaturation of mitochondrial proteins in connection with mitochondrial
cytoplasmic redistribution.
PMID- 10676859
TI - Effects of an adenosine analogue administration on the striatal NMDA receptors in
an experimental model of epilepsy.
AB - Specific [3H]-MK801 binding to rat NMDA receptors following the administration of
the convulsant drug 3-mercaptopropionic acid (MP) and the adenosine analogue
cyclopentyladenosine (CPA) was studied in striatal membrane fractions. MP
administration (150 mg/kg, i.p.) caused an increase of 53% and 82% in [3H]-MK801
binding during seizure and the postseizure period respectively. Administration of
CPA (2 mg/kg, i.p.) raised [3H]-MK801 binding by 72%. When CPA was administered
30 min before MP and rats sacrificed at seizure (CPA + MPc), an increase of 64%,
was observed. Saturation results indicate that receptor sites increased their
maximal binding capacity (Bmax) in all treatments while the apparent dissociation
constant (Kd) remained unchanged. MP administration brought about an increase of
52% and 42% in [3H]-MK801 binding sites during seizure and postseizure
respectively. Administration of CPA raised receptor density by 75%. When CPA was
administered 30 min before MP and rats sacrificed at seizure (CPA + MPc), an
increase of 62%, was observed. These results show that striatal NMDA receptors
have a selective role in seizure activity in the basal ganglia and that the
adenosine analogue administration may modify [3H]-MK801 binding in a way similar
to that of the convulsant drug.
PMID- 10676860
TI - Uncompetitive stimulation of rat brain Na-K ATPase activity by rapid eye movement
sleep deprivation.
AB - Rapid eye movement sleep deprivation is associated with an increase in Na-K
ATPase activity. In order to understand the possible biochemical mechanism of
this increase, the kinetics of Na-K ATPase was studied. Although the enzyme
activity increased after the deprivation, the catalytic efficiency of the enzyme
remained unaltered. The rapid eye movement sleep deprivation increased both the
Vmax and the Km suggesting an uncompetitive stimulation of the enzyme. While
increase in norepinephrine resulted in an increased Vmax, that of calcium
increased the Km. Since an increase in norepinephrine has been suggested after
deprivation, the increased Vmax is attributed to increased norepinephrine level
following deprivation. However, since rapid eye movement sleep deprivation is
reported to be associated with a decrease in calcium levels, the increase in Km
following deprivation may be attributed to changes in factor(s) other than
calcium.
PMID- 10676861
TI - Adenosine modulation of D-[3H]aspartate release in cultured retina cells exposed
to oxidative stress.
AB - In this study we evaluated the role of adenosine receptor activation on the K+
evoked D-[3H]aspartate release in cultured chick retina cells exposed to oxidant
conditions. Oxidative stress, induced by ascorbate (3.5 mM)/Fe2+ (100 microM),
increased by about fourfold the release of D-[3H]aspartate, evoked by KCl 35 mM
in the presence and in the absence of Ca2+. The agonist of A1 adenosine
receptors, N6-cyclopentyladenosine (CPA; 10 nM), inhibited the K+-evoked D
[3H]aspartate release in control in oxidized cells. The antagonist of A1
adenosine receptor, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX; 50 nM),
potentiated the release of D-[3H]aspartate in oxidized cells, and reverted the
effect observed in the presence of CPA 10 nM. However, in oxidized cells, when
DPCPX was tested together with CPA 100 nM the total release of D-[3H]aspartate
increased from 5.1 +/- 0.4% to 11.4 +/- 1.0%, this increase being reverted by 3,7
dimethyl-1-propargylxanthine (DMPX; 100 nM), an antagonist of A2A adenosine
receptors. In cells of both experimental conditions, the K+-evoked release of D
[3H]aspartate was potentiated by the selective agonist of A2A adenosine
receptors, 2-[4-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamidoadenosin e
(CGS 21680; 10 nM), whereas the antagonist of these receptors, DMPX (100 nM),
inhibited the release of D-[3H]aspartate in oxidized cells, but not in control
cells. Adenosine deaminase (ADA; 1 U/ml), which is able to remove adenosine from
the synaptic space, reduced the K+-evoked D-[3H]aspartate release, from 5.1 +/-
0.4% to 3.1 +/- 0.3% in oxidized cells, and had no significant effect in control
cells. The extracellular accumulation of endogenous adenosine, upon K+
depolarization, was higher in oxidized cells than in control cells, and was
reduced by the inhibitors of adenosine transporter (NBTI) and of ecto-5'
nucleotidase (AOPCP). This suggests that adenosine accumulation resulted from the
outflow of adenosine mediated by the transporter, and from extracellular
degradation of adenine nucleotide. Our data show that both inhibitory A1 and
excitatory A2A adenosine receptors are present in cultured retina cells, and that
the K+-evoked D-[3H]aspartate release is modulated by the balance between
inhibitory and excitatory responses. Under oxidative stress conditions, the
extracellular accumulation of endogenous adenosine seems to reach levels enough
to potentiate the release of D-[3H]aspartate by the tonic activation of A2A
adenosine receptors.
PMID- 10676862
TI - Impact of modifying priming components and fluid administration using
miniaturized circuitry in neonatal cardiopulmonary bypass.
AB - Following a succession of changes in circuitry and priming additives between 1993
and 1998, a comprehensive re-evaluation of neonatal cardiopulmonary bypass (CPB)
practice was undertaken. Samples from 10 infants (Group 1) undergoing CPB were
evaluated for osmolality, oncotic pressure, total protein, hematocrit, glucose,
and electrolytes (Na+, K+, iCa2+). These samples were tested at six measurement
points: (1) after priming, (2) patient pre-CPB, (3) CPB-start, (4) CPB-mid, (5)
CPB-end, and (6) post-modified ultrafiltration (MUF). Prime volumes were also
carefully measured as well as the type and amount of volume given during CPB.
After evaluating the initial data, changes in protocol regarding mannitol,
calcium correction, and oncotic strength on CPB were made. Following
implementation of these protocol changes, a second set (Group 2) of 10 infants
was identically evaluated. Group 1 prime osmolality was 379 +/- 44 mOsm/kg, while
Group 2 prime osmolality was 324 +/- 14 mOsm/kg (p = 0.003). There were no
differences in osmolality between groups during bypass and osmolality was
unaffected by modified ultrafiltration. Ionized calcium levels were significantly
different at the end of bypass between Group 1, 0.6 +/- 0.1 mmol/l; and Group 2,
1.17 +/- 0.24 mmol/l (p < 0.001). In Group 1, there was a 40% drop (p = 0.001) in
colloid osmotic pressure (COP) levels from pre-CPB (13.3 +/- 3.4 mmHg) to CPB-end
(8.8 +/- 1.2 mmHg). In Group 2, there were no differences in COP during CPB. COP
levels of Group 1 and Group 2 at CPB-end were 8.8 +/- 1.2 mmHg and 14 +/- 1.9,
respectively (p < 0.0001). Total volume addition during bypass for Group 1 was
363.5 +/- 148.7 ml and for Group 2 was 245.1 +/- 92.2 ml (p < 0.05). In
conclusion, progressive changes in neonatal circuits and techniques can have
potentially wide-ranging effects on electrolyte and osmotic/oncotic homeostasis.
An audit of perfusion management through expanded laboratory tests is
recommended, especially in periods of change.
PMID- 10676863
TI - Comparison of Sarns 3M heparin bonded to Duraflo II and control circuits in a
porcine model: macro- and microanalysis of thrombi accumulation in circuit
arterial filters.
AB - Heparin-bonded perfusion circuits have been reported to reduce the thrombus
formation during various levels of systemic heparinization. The goal of this
study was to compare the efficacy of thrombo-resistance of the Sarns 3M heparin
bonded circuit to Baxter Duraflo II and untreated control in a porcine model.
Fifteen Yorkshire pigs (60-65 kg) were anesthetized, heparinized with 3000 IU,
intravenously (i.v.) and surgically cannulated with an internal jugular outflow
and a femoral vein inflow. All circuits consisted of a 22-Fr venous cannula,
centrifugal pump, arterial filter, an 18-Fr cannula for return and connected with
equal lengths of 3/8" polyvinyl chloride tubing. The flows were maintained at 2.0
l/min for 4 h. Thrombus formation in filter samples were morphometrically
analyzed through macro-densitometry, light microscopy, and scanning electron
microscopy (SEM). Our findings revealed that the 3M circuit had significantly
less gross thrombus (p < 0.001), 66% and 84% less microscopic thrombi and
fivefold less SEM-measured aggregates (p = 0.03) compared to the Duraflo II and
uncoated groups. This study demonstrated that the 3M heparin-bonded circuit had
significantly reduced the formation of micro- and macro-thrombi in the minimally
heparinized pig model compared to the Duraflo II and untreated control circuits.
PMID- 10676864
TI - In vitro evaluation of sedative drug losses during extracorporeal membrane
oxygenation.
AB - Sedative agents are routinely administered to critically ill patients, both on
and off extracorporeal membrane oxygenation (ECMO), to enable patients to be
comfortable and facilitate patient management. It has been observed empirically
in our paediatric intensive care unit that doses of sedative drugs required to
achieve desired levels of sedation in ECMO patients are far greater than those
used in non-ECMO patients. These differences could not simply be accounted for by
differences in patient types, clinical status or sedation levels. We therefore
undertook an in vitro evaluation of drug binding in ECMO circuits. This study
investigated how the polyvinyl chloride (PVC) and silicone rubber components of
neonatal ECMO circuits affect drug delivery in patients through drug sorption.
Phase 1 investigated drug uptake by the two polymers in static solutions of known
concentrations of four commonly used sedative drugs: lorazepam, midazolam,
diazepam and propofol. Phase 2 involved the setting up of a complete neonatal
ECMO circuit, injecting the drug solutions pre reservoir at a flow rate of 350
ml/min and collecting samples post-oxygenator for analysis. Phase 1 results
revealed significant uptake of drugs with losses in the range 40-98% and in the
order propofol > diazepam > midazolam > orazepam. Phase 2 results were similar
and in the first 40 min of running an ECMO circuit only 10% of propofol passed
through the circuit. These results may help to explain observed clinical
phenomena and raise important issues regarding drug dosing in ECMO patients.
PMID- 10676865
TI - The hazardous effects of alveolar hypocapnia on lung mechanics during weaning
from cardiopulmonary bypass.
AB - The bronchoconstrictive effects of alveolar hypocapnia during weaning from
cardiopulmonary bypass (CPB) were investigated in patients undergoing elective
coronary artery revascularization. Thirty patients were randomly assigned into
two equal groups. In both groups, mechanical ventilation was initiated for 3 min
prior to weaning from CPB with the venous pressure low. This kept the pulmonary
vascular bed empty, resulting in alveolar hypocapnia (ETCO2 < 2 kPa). Peak airway
pressure (P(peak)) and plateau pressures (P(plateau)) were recorded. In group 1,
5% CO2 was added to the inspiratory gas mixture and the ETCO2 allowed to rise
(ETCO2 > 3.3 kPa). The ventilation pressure measurements were recorded again
after 3 min stabilization. In group 2, the venous pressure was increased to allow
the pulmonary venous bed to fill and the ventilation pressures recorded after a 3
min period of stabilization. In group 1, the ventilatory pressures dropped
significantly (p < 0.001) when the alveolar hypocapnia was reversed with added
CO2 (P(peak) 19.71 +/- 5.7 to 12.31 +/- 2.8 cmH2O and P(plateau) 13.15 +/- 3.28
to 9.15 +/- 2.23 cmH2O). In group 2, a similar effect was achieved by allowing
filling of the pulmonary vascular bed (P(peak) 17.46 +/- 4.72 to 11.92 +/- 3.03
cmH2O and P(plateau) 13.93 +/- 4.10 to 9.37 +/- 3.00 cmH2O). These results
suggest that filling the pulmonary vascular bed prior to initiating ventilation,
when weaning from CPB, prevents the otherwise deleterious effects of alveolar
hypocapnia, resulting in raised bronchomotor tonus and raised airway pressures.
PMID- 10676866
TI - Red blood cell trauma during cardiopulmonary bypass: narrow pore filterability
versus free haemoglobin.
AB - Ten patients admitted for coronary artery bypass grafting were investigated with
respect to the influence of cardiopulmonary bypass (CPB) on red blood cell (RBC)
trauma. Blood samples were collected prior to, at the start of, and at 30 and 60
min of CPB. RBC deformability was assessed by filtering re-suspended RBCs through
a polycarbonate membrane using a computer-controlled filtrometer. Multiple
regression analysis was employed to evaluate RBC flow-curve characteristics
denoted by the initial filtration rate (IFR) and clogging slope (CS). Release of
free haemoglobin was determined concomitantly. IFR was estimated at 90.39
microl/s and CS at -5.32 microl/s2 prior to CPB. During 60 min of CPB, neither
IFR nor CS deviated significantly (p > 0.05) from these reference values.
However, release of free haemoglobin increased significantly (p < 0.018) from the
start of CPB to the 60-min determination. In conclusion, 60 min of CPB seems not
to alter significantly RBC deformability in a 5 microm pore filtration model,
despite a significant release of haemoglobin.
PMID- 10676867
TI - Platelets and whole blood coagulation.
AB - In our early work in developing activated clotting time (ACT) assays, it became
apparent that changes occurred in coagulation times as a whole blood sample aged
(0-6 h). Subsequent studies showed that the coagulation parameters of plasma
obtained from the samples remained stable during this time frame. These changes
in whole blood clotting times during storage were eventually traced to the
platelets. Several years of work demonstrated that this change was due to the
removal of the blood from the vascular lining. This recalled a mechanism that was
originally put forth in the 1970s with the discovery of prostacyclin. In this
postulated mechanism, platelets are 'time-bombs'. They are kept under control by
prostacyclin (PGI2) secreted by the vascular lining. Without this prostacyclin,
platelets 'preactivate'. Since that time, additional substances secreted by the
vascular endothelium have been identified, such as nitric oxide, that also
influence platelet activity. The 'preactivation' of platelets in a blood sample
can be followed using an ACT. In the same donor, the preactivation is uniform and
reproducible over an extended period (months). There is, however, considerable
variability between donors. Some donors' platelets preactivate dramatically,
while other donors show hardly any change. Prostacyclin, added to the blood
sample when it is collected, prevents this preactivation. The clinical
significance of these observations has yet to be clearly established, but these
observations raise a number of questions with respect to methods for improving
platelet function during bypass and in evaluating the risk of platelet-mediated
cardiovascular disease.
PMID- 10676868
TI - A retrospective study on perfusion incidents and safety devices.
AB - Despite the acceptance of extracorporeal circulation as an effective modality to
facilitate cardiac surgery, patient outcomes can be negatively influenced by the
occurrence of perfusion incidents. A perfusion survey was conducted to identify
safety techniques and incidents related to cardiopulmonary bypass (CPB). An 80
question survey was mailed to chief perfusionists of all 1030 USA cardiac
surgical centers using CPB. The survey was designed to examine practices and
incidents that occurred during a 2-year period (July 1996 to July 1998). Five
hundred-and-fifty-two (54% response rate) surveys were returned, which accounted
for 797 hospitals (79% of all cardiac centers) and 653,621 surgical procedures.
Of the 27 identified CPB safety devices, the highest utilization was arterial
line filters (98.5%) and the lowest arterial line bubble traps (3.4%). Of the
reported cases, a CPB incident occurred once every 138 cases. The most common
occurring incidents were protamine reactions (1:783), coagulation problems
(1:771), and heater/cooler failures 11:1809). The rate of occurrence of an
incident resulting in a serious injury or death was one for every 1453
procedures. Although techniques and safety devices create a relatively secure
environment for CPB, lower incident rates may be achieved with further
improvements in coagulation monitoring and incident reporting.
PMID- 10676869
TI - Vacuum-assisted venous return in pediatric cardiopulmonary bypass.
AB - Vacuum-assisted venous return (VAVR) has been reported to offer benefits for
adults undergoing cardiopulmonary bypass (CPB), such as improved venous return,
lowering priming volume (by eliminating the need to prime the venous line), and
the use of smaller venous cannulae. All these benefits would be of particular
value in pediatric perfusion because of the unique challenges of these smaller
patients and the relatively large components of the CPB circuit. We have been
using VAVR in children since the early summer of 1998 after we became comfortable
with the technique and convinced of its efficacy in adults. Ours is a medium
sized pediatric caseload of slightly more than 100 CPB cases per year. With that
caseload, it is most effective for us to minimize the inventory of different
sizes of disposables used. We have opted for an oxygenator/reservoir that has a
maximum flow of 4 liters with a priming volume of about 1 liter. We have been
unhappy with the large prime volume in infants and earlier, in 1997-1998, were
using a smaller prime oxygenator/reservoir until it was recalled. Faced again
with a larger priming volume in the infants, we decided to try vacuum to decrease
hemodilution and to evaluate other possible benefits. Through the use of VAVR, we
have been able to decrease our priming volume, use smaller venous cannulae, and
have more consistent return while experiencing no adverse effects of VAVR in our
pediatric cardiac surgery patients.
PMID- 10676870
TI - An in vitro evaluation of a new cannula tip design compared with two clinically
established cannula-tip designs regarding aortic arch vessel perfusion
characteristics.
AB - We investigated in vitro aortic arch vessel perfusion characteristics of single
and multiple jet-stream cannulae and a new dispersion stream tip aortic cannula.
Pressures and flows of all arch vessels were measured while directing cannulae
jets at the different arch vessels using 6 l/min pump flow. The highest increase
in pressure above the set systemic level of 80 mmHg and increase in flow above
the set normal flow distribution in the arch vessels occurred in the jet-streamed
arch vessels with the single stream cannula. The values were as follows: 29 mmHg
and 118 ml/min for the innominate artery, 28 mmHg and 42 ml/min for the left
common carotid artery, and 25 mmHg and 54 ml/min for the left subclavian artery.
The dispersion stream cannula showed increases in pressure and flow, followed by
the multiple stream cannula. Aortic cannula tips and the orientation of jets are
potential sources of imbalances of arch vessel perfusion with possible clinical
implications regarding perfusion of arch vessels during extracorporeal
circulation.
PMID- 10676871
TI - Affinity pump system: a new peristaltic blood pump for cardiopulmonary bypass.
AB - An in vitro study has been carried out to assess the pump performance of a new
peristaltic, extracorporeal displacement pump (Affinity) for cardiopulmonary
bypass. The pump system consists of a pump rotor (0-110 rpm), a pump chamber, a
venous reservoir with a 5/8" connecting tube and the Affinity console. The
polyurethane chamber is connected to the venous reservoir by a 5/8" tube and
fills passively due to the hydrostatic pressure exhibited by the fluid height in
the venous reservoir. The implementation of an occlusive segment in the pump
chamber, which collapses in low filling states, should prevent significant
negative pressures. An in vitro circuit was filled with bovine blood (37 degrees
C, hematocrit 35%) and the pump flow was measured by an ultrasonic transit time
flow probe with respect to pre-load, diameter and length of attached tubing in
the venous line, pump speed (rpm) and size of the connecting tube (3/8" and
5/8"). At 108 rpm and a preload equal to 10 mmHg, the flow was 8.6 +/- 0.42 l/min
for an afterload of 80 mmHg. The reduction of the inlet connector to 3/8"
diminished the pump flow significantly to 5.2 +/- 0.31 l/min (p < 0.0001). The
pump flow decreased linearly with respect to the length of the attached tube in
the venous line and for a 2 m long 5/8" silicon tube, the rpm-optimized flow was
still 6.0 +/- 0.28 l/min at a preload of 10 mmHg. In case of low filling state or
too high rpm, the occlusive segment collapsed and no cavitation bubbles could be
detected. Our in vitro measurements yield a nomogram for rpm-optimized blood flow
with respect to the pre-load in the venous reservoir. The delivered
5/8"connecting tube facilitates optimum filling of the pump chamber for high
blood flow, but limits the use of venous reservoirs to Affinity products. The
pump yields a high blood flow even when long tubing in the venous line is used.
This makes the pump a candidate for a ventricular assist device. In hypovolemia
or high rpm, the occlusive segment collapses and no negative pressure is
generated at the inflow site of the pump chamber.
PMID- 10676872
TI - Effect of chronic paroxetine treatment on 5-HT1B and 5-HT1D autoreceptors in rat
dorsal raphe nucleus.
AB - This study reports the effect of chronic paroxetine (10 mg/kg p.o., 21 days) on 5
HT1B and 5-HT1D autoreceptors controlling stimulated 5-HT efflux in slices of rat
dorsal raphe nucleus. Electrically evoked 5-HT (10 pulses, 200 Hz, 0.1 ms, 10 mA)
was measured using fast cyclic voltammetry. 5-HT efflux was inhibited by CP 93129
(10 nM-10 microM) and by sumatriptan (1 nM-1 microM) agonists at 5-HT1B and 5
HT1D receptors, respectively. Chronic paroxetine did not, initially, appear to
alter the sensitivity of the 5-HT1B autoreceptors to CP 93129. However, when
constructed in the presence of WAY 100635 (10 nM) the selective and silent 5-HT1A
antagonist, there was a significant (P < 0.001) rightward shift of the CP 93129
concentration-response curve in the paroxetine-treated rats but not in the
controls, implying a desensitisation of the 5-HT1B autoreceptor by paroxetine.
Chronic paroxetine did not affect the sumatriptan concentration-response curve,
even with WAY 100635 present, implying that there was no (de)sensitisation of the
5-HT1D autoreceptor. These data suggest that chronic paroxetine treatment may
desensitise 5-HT1B autoreceptors in the dorsal raphe nucleus but that this effect
is unmasked only when the dominant 5-HT1A autoreceptor control is antagonised.
PMID- 10676873
TI - The alpha-ketoglutarate dehydrogenase complex in neurodegeneration.
AB - Altered energy metabolism is characteristic of many neurodegenerative disorders.
Reductions in the key mitochondrial enzyme complex, the alpha-ketoglutarate
dehydrogenase complex (KGDHC), occur in a number of neurodegenerative disorders
including Alzheimer's Disease (AD). The reductions in KGDHC activity may be
responsible for the decreases in brain metabolism, which occur in these
disorders. KGDHC can be inactivated by several mechanisms, including the actions
of free radicals (Reactive Oxygen Species, ROS). Other studies have associated
specific forms of one of the genes encoding KGDHC (namely the DLST gene) with AD,
Parkinson's disease, as well as other neurodegenerative diseases. Reductions in
KGDHC activity can be plausibly linked to several aspects of brain dysfunction
and neuropathology in a number of neurodegenerative diseases. Further studies are
needed to assess mechanisms underlying the sensitivity of KGDHC to oxidative
stress and the relation of KGDHC deficiency to selective vulnerability in
neurodegenerative diseases.
PMID- 10676874
TI - A critical histidine in the vesicular acetylcholine transporter.
AB - The role of proton binding sites in the vesicular acetylcholine transporter was
investigated by characterization of the pH dependence for the binding of
[3H]vesamicol [(-)-trans-2-(4-phenylpiperidino)cyclohexanol] to Torpedo synaptic
vesicles. A single proton binds to a site with pKa 7.1 +/- 0.1, which is
characteristic of histidine, to competitively inhibit vesamicol binding. The
histidine-selective reagent diethylpyrocarbonate causes time-dependent inhibition
of [3H]vesamicol binding with a rate constant only about 20-fold lower than for
reaction with free histidine. Because its pH titration has a simple, ideal shape,
this residue probably controls all pH effects in the transporter between pH 6-8.
Inhibition of [3H]vesamicol binding by diethylpyrocarbonate was slowed by
vesamicol but not acetylcholine, which binds to a separate site. The data suggest
that a critical histidine with a pKa of 7.1 is unhindered when reacting with
diethylpyrocarbonate. A conformational model for the histidine is proposed to
explain why acetylcholine competes with protons but not with
diethylpyrocarbonate. A conserved histidine in transmembrane helix VIII possibly
is the histidine detected here.
PMID- 10676875
TI - Activation of apoptosis-linked caspase(s) in NMDA-injured brains in neonatal
rats.
AB - Unilateral injection of 50 nmol of N-methyl-D-aspartate (NMDA) into the left
posterior striatum of 7 day-old rat pups induces massive neuronal loss in the
ipsilateral hemisphere in 5 days. In this model of excitotoxicity, the form of
neuronal death (necrosis vs apoptosis) has not been clearly addressed. Here we
report evidence of DNA laddering in the ipsilateral hemisphere 24 h after the
NMDA injection. Activation of apoptosis-linked caspase(s) was also identified, as
evidenced by (i) the formation of caspase-produced 120 kDa alpha-spectrin
breakdown product (SBDP120) and (ii) increase in hydrolysis of caspase-3
substrate acetyl-DEVD-7-amido-4-methylcoumarin in the homogenate from the
ipsilateral hemisphere. Lastly, we note that i.p. injection (100 mg/kg) of a pan
caspase inhibitor Z-D-DCB attenuates the levels of SBDP120. Our results suggest
the presence of caspase-activation in this rat pup model of NMDA toxicity.
PMID- 10676876
TI - Effect of ethanol on ATP-induced phospholipases C and D and serine base exchange
in glioma C6 cells.
AB - The effect of extracellular ATP, a nucleotide receptor agonist in the central
nervous system, was investigated in glioma C6 cells on the intracellular Ca2+
level and the formation of phosphatidylethanol and phosphatidic acid in the
presence and absence of ethanol (150 mM). In the cells prelabeled with
[14C]palmitic acid, 100 microM ATP induced both the hydrolysis and the
transphosphatidylation reactions leading to the formation of [14C]phosphatidic
acid; addition of ethanol generated [14C]phosphatidylethanol. However, ATP
mediated increase in the level of [14C]phosphatidic acid was not inhibited by
ethanol. Furthermore, ethanol augmented ATP-induced transient and sustained
increase in the intracellular Ca2+ concentration, whereas ethanol alone did not
produce any change in the intracellular Ca2+ level. These results indicate that
in glioma C6 cells, ATP induces activation of polyphosphoinositide-specific
phospholipase C and phospholipase D and that ethanol enhances this effect. In the
present investigation we have also shown that long-term (2 days) ethanol
treatment, at concentration relevant to chronic alcoholism (100 mM), decreased
the incorporation of [14C]serine into phosphatidylserine. Since the effect of
ethanol on ATP-induced activities of phospholipase C and phospholipase D and on
serine base-exchange in glioma C6 cells differs significantly from that in
cultured neuronal cells, these results may contribute to a better understanding
of the mechanisms of ethanol action in cells of glial origin.
PMID- 10676877
TI - Psychotomimetics moderately affect dopamine receptor binding in the rat brain.
AB - The hypothesis that psychotomimetics induce a rapid dopamine receptor regulation
that could participate in the expression of the brain dopaminergic overactivation
and in the early signs of psychotic-like behaviour, was checked by radioligand
binding on rat brain cryosections. For this purpose, subchronic 7-day-d
amphetamine pretreatment was combined with acute amphetamine, phencyclidine or
LSD challenge. Acute application of psychotomimetics affected only striatal and
accumbens but not nigral and olfactory dopamine receptor binding after 40 min,
while subchronic amphetamine expressed no effect, as revealed by two-way ANOVA.
Post-hoc statistical analysis showed that only striatal and accumbens[3H]SCH
23390 binding decrease (10-12%) following phencyclidine and striatal
[3H]spiperone binding increase (11%) after acute amphetamine were significant. It
is assumed that such moderate dopamine receptor binding changes probably reflect
the fast receptor regulation responses without important influence on a proposed
drug-induced dopaminergic overactivity. The registered alterations of D1 receptor
binding after phencyclidine are suggested to be capable to modify the activity of
some other neural pathways in the basal ganglia and thus participate in a
psychotic-like behaviour.
PMID- 10676878
TI - Expressions of amyloid precursor protein, synaptophysin and presenilin-1 in the
different areas of the developing cerebellum of rat.
AB - This study reveals the expressions of Alzheimer's disease-related amyloid
precursor protein, presenilin-1, and a presynaptic marker protein, synaptophysin,
in the archi-, paleo- and neocerebellum during the postnatal development of the
rat. The Western blot results demonstrate a gradual increase in the soluble
amyloid precursor protein level in the archicerebellum during the first 3 weeks,
while in the neo- and paleocerebellum the levels reach a plateau as early as the
1st week. Immunohistochemically, the protein is present in the deep part of the
external granule cell layer and the internal granule cell layer in the newborn
animal, while in 3-week-old animals the staining appears mainly in the perikarya
and dendrites of the Purkinje cells. The level of synaptophysin increases
progressively from postnatal day 7 up to 3 weeks in the archi- and
paleocerebellum, and up to 6 weeks in the neocerebellum. Immunohistochemically,
the amyloid precursor protein staining appears first in the inner part of the
molecular layer and in the internal granule cell layer. In a 3-week-old animal,
synaptophysin staining is present in all areas of the cerebellar molecular layer
and in the internal granule cell layer. The presenilin-1 immunohistochemical
reaction appeared equally in the archi-, paleo- and neocerebellum. Much of the
staining is present in the glial cells and Purkinje cells. Less immunoreactivity
is observed in the Golgi cells and granule cells. It is concluded that the
postnatal expressions of soluble and membrane-bound amyloid precursor protein,
synaptophysin and presenilin-1 are regulated differently during the ontogenetical
development of the archi-, paleo- and neocerebellum of rat. Further, the amyloid
precursor protein and presenilin-1 may be present in cells which do not
degenerate in Alzheimer's disease.
PMID- 10676879
TI - Internalization and down-regulation of muscarinic acetylcholine receptors in
cerebellar granule cells of tenascin-gene deficient mice.
AB - The expression of tenascin-C on oligodendrocytes parallels the migration of
granule cells in the developing cerebellum, indicating a role for tenascin-C as a
guide for granule neurons to find their proper locations. In this study, cultured
cerebellar granule neurons from tenascin-C-knockout mice were used to examine the
role of tenascin-C in agonist-induced muscarinic acetylcholine receptor down
regulation. Exposure of granule cells from wild-type or tenascin-C-negative mice
to the muscarinic acetylcholine receptor agonist carbachol (1 mM) resulted in
normal sequestration of cell-surface muscarinic acetylcholine receptors as
assessed by [3H]N-methylscopolamine binding; however, down-regulation of total
muscarinic acetylcholine receptors, measured with [3H]quinuclidinyl benzilate,
was inhibited in granule cells from tenascin-C-negative mice. Remarkably,
incubation of the tenascin-C-negative cells with the microtubule stabilizer taxol
(10 microM) restored down-regulation of total muscarinic acetylcholine receptors
to normal levels. We speculate that agonist-induced down-regulation of muscarinic
acetylcholine receptors is functionally associated with tenascin-C-regulated
microtubule structures in the developing cerebellum.
PMID- 10676880
TI - Glutamate-mediated inhibition of oxidative phosphorylation in cultured retinal
cells.
AB - Glutamate is an excitotoxin responsible for causing neuronal damage associated
with mitochondria dysfunction. We have analyzed the relationship between the
mitochondrial respiratory rate, the membrane potential (delta psi) and the
activity of mitochondrial complexes in retinal cells in culture, used as neuronal
models. Glutamate (10 microM-10 mM) dose-dependently decreased the O2 consumption
and the membrane potential. A linear correlation was found between these
parameters, suggesting that the mitochondrial respiratory function was affected.
Exposure to glutamate (100 microM) for 10 min, in the absence of Mg2+, inhibited
the activity of complex I (26.3%), complexes II/III (22.2%) and complex IV
(26.7%). MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10
imine hydrogen maleate), a non-competitive antagonist of the NMDA (N-methyl-D
aspartate) receptors, completely reversed the effect exerted by 100 microM
glutamate at the level of complexes I, II/III and IV. These results suggest that
NMDA receptor-mediated inhibition of mitochondrial respiratory chain complexes
may be responsible for the alteration in the respiratory rate of chick retinal
cells submitted to glutamate.
PMID- 10676881
TI - Transient treatments with L-glutamate and threo-beta-hydroxyaspartate induce
swelling of rat cultured astrocytes.
AB - We characterized swelling of rat cultured astrocytes induced by L-glutamate and
its analogues. Among L-glutamate receptor agonists, L-glutamate, L-aspartate, L
cysteic acid, DL-homocysteic acid, quisqualate and (+/-)-1-aminocyclopentane
trans-1,3-dicarboxylic acid (trans-ACPD) increased astrocytic intracellular
volume (3H-OMG space), while kainate, and N-methyl-D-aspartate did not. Threo
beta-hydroxyaspartate (TBHA), D-aspartate and L-trans-pyrrolidine-2,4
dicarboxylic acid, high-affinity substrates for Na+-dependent L-glutamate
transporters, increased astrocytic 3H-OMG space. L-Glutamate (0.5 mM) increased
astrocytic 3H-OMG space to 300% of control in 40-60 min. The increase in 3H-OMG
space by 1 mM TBHA was comparable to the L-glutamate-induced one. After a 10 min
exposure to 0.5 mM L-glutamate, astrocytic 3H-OMG space was further increased to
200% even in the absence of L-glutamate. Astrocytes transiently exposed to L
glutamate did not increase their cell volume in K+-free medium and in the
presence of 1 mM ouabain, a Na+-K+ ATPase inhibitor. The increase after a
transient exposure was also observed by a treatment of 1 mM TBHA, but not by 0.5
mM quisqualate. These results suggest that the volume increases after a transient
treatment are mediated by activation of Na+-dependent L-glutamate transporter.
PMID- 10676882
TI - Purification and embryotropic roles of tissue inhibitor of metalloproteinase-1 in
development of "HanWoo" (Bos taurus coreanae) oocytes co-cultured with bovine
oviduct epithelial cells.
AB - This study was conducted to purify a tissue inhibitor of metalloproteinase (TIMP)
1 in a serum-free medium conditioned with bovine oviduct epithelial cells (BOEC)
and to evaluate its effect on development of "HanWoo" (Bos taurus coreanae)
embryos to the blastocyst stage. In the first study using SDS-PAGE
electrophoresis, the presence of 32 kDa proteins, which contains TIMP-1, was
detected in the medium conditioned with BOEC, and TIMP-1 was then purified from
the medium by gel filtration and HPLC techniques. When examined TIMP-1 secretion,
fluorescent foci indicating the secretion of TIMP-1 were found after stained BOEC
with fluorescein isothiocyanate. In the next experiment, two-cell embryos derived
from in vitro-fertilization were cultured in a serum-free medium, to which 0,
1.25, 2.5 or 5 microg/ml of purified TIMP-1 was supplemented. More (P<0.05)
embryos developed to the morula and blastocyst stages after the addition of 2.5
microg/ml to culture medium than after no addition. In conclusion, our data
indicate that BOEC secrete TIMP-1 and this glycoprotein promotes the prehatched
development of "HanWoo" embryos derived from in vitro-fertilization.
PMID- 10676883
TI - Adaptation of the muscles of mastication to the flat skull feature in the polar
bear (Ursus maritimus).
AB - The muscles of mastication of the polar bear (Ursus maritimus) and those of the
brown bear (U. arctos) were examined by anatomical approach. In addition, the
examination of the skull was carried out in the polar bear, brown bear and giant
panda (Ailuropoda melanoleuca). In the polar bear, the rostro-ventral part of the
superficial layer of the M. masseter possessed the abundant fleshy portion folded
in the rostral and lateral directions like an accordion. Moreover, the rostro
medial area of the superficial layer became hollow in the nuchal direction when
the mouth was closed. The M. temporalis of the polar bear covered up the anterior
border of the coronoid process of the mandible and occupied the almost entire
area of the cranial surface. The M. pterygoideus medialis of the polar bear was
inserted on the ventral border of the mandible and on the ventral part of the
temporal bone more widely than that of the brown bear. As results of our
measurements of the mandible, an effect of the leverage in the polar bear was the
smallest in three species. In the polar bear, the skull was flat, and the space
between zygomatic arch and ventral border of the mandible, occupied by the M.
masseter was the narrowest. It is suggested that the muscles of mastication of
the polar bear is adapted to the flat skull feature for supplementing the
functions.
PMID- 10676884
TI - Synthesis and secretion of A-type natriuretic peptide in the auricular
cardiocytes during pregnancy and lactation in mouse.
AB - A-type (atrial) natriuretic peptide (ANP) levels in the auricular cardiocytes and
plasma were examined by immunohistochemistry, electron microscopy, and
radioimmunoassay in pregnant and lactating mice. Additionally, the cardiocyte ANP
mRNA expression was measured by the polymerase chain reaction method. ANP
immunoreactivity (IR) and the number of ANP-granules in the cardiocytes on the
18th day of gestation were greater than those in virgin controls, but the plasma
ANP concentration decreased on the 18th day of gestation. On the day of delivery,
ANP-IR and the number of ANP-granules in the cardiocytes were decreased compared
to those during the pregnancy and to those in virgin controls, and then began to
increase continually until the 15th day of lactation. Plasma ANP concentration
after delivery was significantly higher than that during pregnancy, and than that
in virgin controls, and continued to increase until the 15th day of lactation.
Cardiocyte ANP mRNA expression was highest on the day of delivery compared to
that in all the other times. In conclusion, these results suggested that the
circulating systems of ANP during pregnancy and lactation were regulated
differentially.
PMID- 10676885
TI - Apoptosis and cell proliferation in rat hepatocytes induced by barbiturates.
AB - To examine the effect on cell population in hepatocytes of phenobarbital (PB) and
other barbiturates, PB, allobarbital (ALB), barbital sodium (BS) and barbituric
acid (BA) were given orally to male rats for 7 consecutive days. Although there
was no apparent change in non-promoting BA, hepatomegaly was induced by PB, BS
and ALB, which are promoters of hepatocarcinogenesis. In PB- and BS-treated
livers, hepatomegaly was attributable to hepatocyte proliferation and enzyme
induction. In ALB-treated liver, it was attributable to enzyme induction. The
level of cell proliferation was reduced to less than the control values following
withdrawal of PB, ALB and BS. It seemed that the degree of suppression of cell
proliferation following withdrawal of these compounds correlated to the degree of
cell proliferation (PB>BS>ALB) during treatment. In PB-treated liver, apoptosis
was induced during treatment, serving to eliminate the excess of hepatocytes.
This suggests that short-term administration of PB neither induced suppression of
apoptosis nor disturbed homeostasis of hepatocyte populations.
PMID- 10676886
TI - Involvement of CD28/CTLA4-B7 costimulatory pathway in the development of
lymphadenopathy and splenomegaly in MRL/lpr mice.
AB - MRL/lpr mouse is an established animal model which develops autoimmune diseases
including glomerulonephritis, sialoadenitis, hepatitis and inflammatory lung
disease. Additionally, it has been reported that lpr strains uniquely accumulate
CD3+ CD4- CD8- B220+ (double negative, DN) T cells in lymphoid organs leading to
lymphadenopathy and splenomegaly. To investigate the role of CD28/CTLA4-B7
pathway in the development of lymphadenopathy and splenomegaly, MRL/lpr mice were
treated with soluble form of CTLA4 molecules, CTLA4IgG, which efficiently blocks
this pathway. It was demonstrated that (i) the development of DN T cells was
independent of the CD28/CTLA4-B7 pathway, (ii) the CD28/CTLA4-B7 pathway was
required for the development of lymphadenopathy and splenomegaly, (iii) the
CD28/CTLA4-B7 pathway was important for the accumulation of various cell
populations in the lymph node and spleen, (iv) composition of the accumulating
cell populations was not altered by CTLA4IgG treatment, and (v) activation of
conventional T cells and IL-4 production from conventional T cells were the
CD28/CTLA4-B7 pathway dependent. Thus, we concluded that the CD28/CTLA4-B7
pathway was required for the development of full-blown lymphadenopathy and
splenomegaly in MRL/lpr mice.
PMID- 10676887
TI - Detection of annexins I and IV in bronchoalveolar lavage fluids from calves
inoculated with bovine herpes virus-1.
AB - Annexins are phospholipid-binding proteins and are abundant in the lung. Annexins
I and IV, but not II and VI, have been detected in bronchoalveolar lavage (BAL)
fluids from calves inoculated with Pasteurella haemolytica, the pathogen for calf
pneumonia. In this study, BAL fluids from calves with experimental pneumonia
induced by inoculation to right lung lobes of bovine herpes virus-1 (BHV-1), the
major viral pathogen for pneumonia, were examined for detection of annexins I and
IV. Of 6 calves inoculated with BHV-1, annexins I and IV were coincidentally
detected in BAL fluids from right lung lobes of 4 calves, but not in BAL fluids
from left lung lobes of 6 inoculated calves or those from left and right lung
lobes of 3 control calves. Annexin II and VI were not found in any BAL fluids
examined. These results, together with previous findings on calves inoculated
with Pasteurella haemolytica, suggest that the release of annexins I and IV onto
the alveolar surface is an essential event occurring in response to pulmonary
infections of BHIV-1 and Pasteurella haemolytica.
PMID- 10676888
TI - Effects of antioxidants on induction of apoptosis in bursal cells of Fabricius
during in vitro cultivation.
AB - After physically disrupting cell contacts, apoptosis of bursal cells of Fabricius
was induced during in vitro cultivation. The percentage of apoptotic cells
increased with incubation time and approximately 70% cells represented apoptosis
after 6 hr of incubation. The induction of apoptosis was significantly inhibited
by treatment of the cells with ascorbic acid (vitamin C), but not with trolox, a
vitamin E analog. An intense DNA ladder pattern was shown at 6 hr post-isolation,
which is a biochemical hallmark of apoptosis. Treatment of the cells with
ascorbic acid inhibited the DNA fragmentation, but trolox did not. To monitor the
intracellular production of reactive oxygen species (ROSs), the intensity of
fluorescence emitted from DCFH-DA was measured. The intensity of fluorescence
from cells incubated for 0.5-2 hr was approximately 2-fold higher than that from
cells at 0 hr. The relative intensity of fluorescence decreased immediately after
the addition of ascorbic acid to the cells. The intensity from the cells treated
with ascorbic acid was 20-30% of that from the control cells at each incubation
time. For trolox, the intensity was 50-70% of that from the control cells at each
1 to 2 hr incubation time. When ROSs-induced lipid peroxidation was assessed
using cis-parinaric acid (PnA) as a monitor molecule, lipid peroxidation was
found to occur in the control cells after isolation of the bursal cells.
Treatment of the cells with trolox reduced lipid peroxidation, but treatment with
ascorbic acid enhanced peroxidation.
PMID- 10676889
TI - Decreased apolipoprotein C-III concentration in the high-density lipoprotein
fraction from calves inoculated with Pasteurella haemolytica and bovine herpes
virus-1.
AB - Lipoprotein lipid and apoprotein concentrations are known to be altered during
the acute-phase response. We have previously shown that the serum activity of
lecithin:cholesterol acyltransferase (LCAT) and concentration of cholesteryl
esters, both constituents of the high-density lipoprotein (HDL) fraction, are
reduced in calves inoculated with Pasteurella haemolytica and bovine herpes virus
1, the two major pathogens for calf pneumonia. The concentration of
apolipoprotein C-III (apoC-III), a low molecular mass protein component
distributed mainly in the HDL fraction, was therefore examined in bacteria- and
virus-inoculated calves. An enzyme-linked immunosorbent assay demonstrated that
it was decreased by inoculations of Pasteurella haemolytica and bovine herpes
virus-1. The decrease was detected as early as 1 day after inoculation in both
groups. A decreased serum apoC-III concentration was also observed by immunoblot
analysis. It was detected in the HDL fractions from the bacteria- and virus
inoculated calves, and HDL apoC-III concentrations in the inoculated calves were
decreased compared with controls. These results, coupled with the previous
findings on LCAT activity and the cholesteryl ester concentration, indicate that
a decreased HDL concentration is one of the early events occurring during the
acute-phase response evoked by infections with Pasteurella haemolytica and bovine
herpes virus-1.
PMID- 10676890
TI - Regional specialization of ganglion cell layer of the chick retina.
AB - Specialization of the ganglion cell layer (GCL) was studied by Nissl-staining and
axonal tract-tracing methods in chicks and chick embryos. The changes in the
retinal area and the cell number in the GCL produced a disparity in the cell
density that occurred through the two different processes, cell generation
(before embryonic days 10-14, E10-14) and cell loss (after E10-14). One high
density area was found in the retinal fundus on E8 (presumptive central area,
pCA) and its density decreased toward the peripheral retina. Another high-density
area was found in the dorsal retina on E11 (presumptive dorsal area, pDA). Cell
densities of the pCA and the pDA on E11 decreased gradually to 25-30% by P1, and
after that they further decreased to 40-60% by P30. The pCA was still identified
on P30, but the pDA became very obscure by this age. In contrast, ganglion cell
sizes increased 5-7 times in the pCA and pDA from E8 to P30, and increased 12
times in the temporal periphery. The present study suggests that the center
peripheral gradient of cell density results from lager scale of cell genesis in
the pCA, but not from lager scale of cell loss in the peripheral retina. However,
obscuration of the pDA results from equalization of cell density in cellular
degeneration processes.
PMID- 10676891
TI - A hematological study on thirteen cats with myelodysplastic syndrome.
AB - Hematological abnormalities were investigated in 13 cats with myelodysplastic
syndrome (MDS). Examination of the peripheral blood samples from the 13 cats
revealed anemia in 11 cats, leukopenia in 9 cats, and thrombocytopenia in 9 cats.
Four cats had pancytopenia (30.8%) and 9 cats had bicytopenia (69.2%). Dysplastic
changes of erythrocytes, neutrophils, and platelets in the peripheral blood were
found in 5, 10 and 8 cats, respectively. Bone marrow examination of the 13 cats
revealed that ratios of blast cells to all nucleated cells (ANC) ranged from 0 to
20%. Ratios of erythroid progenitor cells to ANC were more than 50% in 3 cats and
less than 50% in 10 cats. Eosinophils accounted for more than 5% of non-erythroid
cells in 10 cats. Dysplastic changes in the granurocytic, erythrocytic, and
megakaryocytic cells in the bone marrow were found in 11, 7 and 5 cats,
respectively. Dysplastic changes in these cats included giant neutrophils, ring
nucleated neutrophils, binuclear myelocytes, hypersegmented and hyposegmented
neutrophils, megaloblastoid erythroblasts, multinucleated erythroblasts,
micromegakaryocytes, and segmented multinucleated megakaryocytes. Virological
examination indicated the presence of feline leukemia virus antigen in the
peripheral blood from all of the 13 cats with MDS. The peripheral blood
cytopenias and dysplastic changes in each blood cell lineage in the bone marrow
were shown to be important for the diagnosis of MDS in cats.
PMID- 10676892
TI - Induction of dog sperm capacitation by glycosaminoglycans and glycosaminoglycan
amounts of oviductal and uterine fluids in bitches.
AB - Ejaculated sperm collected from 12 beagle dogs were incubated in canine
capacitation medium (CCM), supplemented with 5 microg/ml chondroitin sulfate A
(CS), 5 microg/ml hyaluronic acid (HA), or 5 microg/ml heparin (HP) for 7 hr at
38 degrees C in a 5% CO2 in air atmosphere to investigate the effects of
glycosaminoglycans (GAGs) on dog sperm capacitation. The percentages of motile
sperm, hyperactivated sperm (%HY), and acrosome-reacted sperm (%AR) in all media
were examined after 4 hr and 7 hr of incubation. The oviducts and uteri of 9
anestrous and 18 estrous beagle bitches were removed under halothane inhalation
anesthesia to measure the total GAG amounts in oviductal and uterine fluids. The
lumens of the ampulla of the oviducts, isthmus of the oviducts, and the uterine
horns were each flushed with 1 ml HEPES-EDTA fluid. Total GAG amounts in the
flush fluids obtained were measured with a spectrophotometer. Sperm motility (51
59%), %HY (79-86%), and %AR (31-36%) in CCM supplemented with CS, HA, or HP were
significantly higher after 7 hr of incubation than when incubated in CCM without
GAGs (P<0.01 or 0.05). The mean total GAG amounts in the fluids from the ampulla
and isthmus of the oviducts and the uterine horns in the estrous bitches were
higher than in the anestrous bitches. These results indicate that GAGs in the
oviductal and uterine fluids in estrous bitches are associated with in vivo sperm
capacitation.
PMID- 10676893
TI - Effects of orchidectomy on bone metabolism in beagle dogs.
AB - The effects of orchidectomy on bone metabolism in male beagle dogs were examined
using twelve 2-year-old dogs that were orchidectomized. The dogs' bilateral iliac
bones, double-labeled with tetracycline and calcein for the histomorphometry,
were obtained from three dogs prior to orchidectomy and at 3, 6, 9, and 12 months
afterwards. The serum biochemical constituents related to bone metabolism were
examined before and every month after orchidectomy. Between 1 and 6 months after
orchidectomy, the value of serum testosterone decreased (1 month), while the
levels of parathyroid hormone, calcitonin, total calcium, osteocalcin, and
alkaline phosphatase activity increased significantly, indicating a high bone
turnover. The mean trabecular thickness and the fraction of labeled osteoid
surface decreased significantly 3 months after orchidectomy, but other
histomorphometric parameters were unchanged. In the period 7-12 months after
orchidectomy, the parathyroid hormone level increased ever and above that of the
first 6-month period, while the levels of calcitonin, osteocalcin, alkaline
phosphatase activity, and phosphorus decreased. The bone volume, mean trabecular
thickness, and the fraction of labeled trabecular surface decreased significantly
compared with the pre-orchidectomy values. These findings indicate an imbalance
in bone metabolism (i.e. bone resorption > bone formation). These results
indicate that a loss of bone volume accompanied the fall in sex hormone levels
following orchidectomy and suggest that the orchidectomized dog is available as
an animal model for studying osteoporosis caused by hypogonadism and the decline
of sex functions in men.
PMID- 10676894
TI - 1Alpha-hydroxyvitamin D3 prevents the decrease of bone mineral density in
lactating beagles.
AB - We assessed the change of bone mineral density (BMD) in lactating beagles with
dual energy X-ray absorptiometry (DXA) and the preventive effect of 1alpha
hydroxyvitamin D3 (1alpha(OH)D3) on the BMD. Beagles, two to five years old, were
used for detecting the time course change of BMD. Since the coefficient of
variation (CV(%)) on detecting lumber vertebral (L2-L4) and tibial BMD by DXA was
about 0.5%, DXA was useful to detect the change of BMD in beagles. There was a
marked decrease in vertebral BMD during lactational period in the control group.
The BMD levels after weaning were found to reverse to the initial level at
mating. The same tendency was observed in tibial BMD as vertebral BMD, though the
BMD changes were not marked. Beagles were administered at a dose of 0.1 microg/kg
of 1alpha(OH)D3 three times in a week, and it was found to suppress the decrease
in vertebral BMD during the breast feeding period. Also, the administration of
1alpha(OH)D3 promoted the prevention of decreased BMD during lactation both in
vertebrae and tibiae. Significant effects of 1alpha(OH)D3 administration on
tibial BMD were not observed. No adverse effects, such as hypercalcemia and
hypercalciuria, were observed during the experimental period. Therefore, DXA was
useful for detecting the changes of BMD in lactating beagles and the change of
BMD was marked in lumber vertebrae, which are rich in trabecular bone. The
preventive effect of 1alpha(OH)D3 on the decrease of BMD during the lactation
period was observed in beagles.
PMID- 10676895
TI - Antemortem evaluation for magnetic resonance imaging of the equine flexor tendon.
AB - In this study antemortem evaluation of equine flexor tendons--the superficial
digital flexor tendon and the deep digital flexor tendon--using magnetic
resonance (MR) images was performed. Postmortem flexor tendons were used to
prepare the slice positions, coil and body positions for MR imaging. It was
possible by this method to take antemortem MR images of equine limbs that
distinguished features as well as postmortem images described in previous
studies. The total time of antemortem scanning was about 40 min. This study is
the first to report antemortem MR images in horses.
PMID- 10676896
TI - Effects of chlorine, iodine, and quaternary ammonium compound disinfectants on
several exotic disease viruses.
AB - The effects of three representative disinfectants, chlorine (sodium
hypochlorite), iodine (potassium tetraglicine triiodide), and quaternary ammonium
compound (didecyldimethylammonium chloride), on several exotic disease viruses
were examined. The viruses used were four enveloped viruses (vesicular stomatitis
virus, African swine fever virus, equine viral arteritis virus, and porcine
reproductive and respiratory syndrome virus) and two non-enveloped viruses (swine
vesicular disease virus (SVDV) and African horse sickness virus (AHSV)). Chlorine
was effective against all viruses except SVDV at concentrations of 0.03% to
0.0075%, and a dose response was observed. Iodine was very effective against all
viruses at concentrations of 0.015% to 0.0075%, but a dose response was not
observed. Quaternary ammonium compound was very effective in low concentration of
0.003% against four enveloped viruses and AHSV, but it was only effective against
SVDV with 0.05% NaOH. Electron microscopic observation revealed the probable
mechanism of each disinfectant. Chlorine caused complete degeneration of the
viral particles and also destroyed the nucleic acid of the viruses. Iodine
destroyed mainly the inner components including nucleic acid of the viruses.
Quaternary ammonium compound induced detachment of the envelope of the enveloped
viruses and formation of micelle in non-enveloped viruses. According to these
results, chlorine and iodine disinfectants were quite effective against most of
the viruses used at adequately high concentration. The effective concentration of
quaternary ammonium compound was the lowest among the disinfectants examined.
PMID- 10676897
TI - Hematological and plasma biochemical values in captive Eld's-Brow Antlered deer
(Cervus eldi thamin) in Thailand.
AB - Blood samples were collected from 20 sedated captive Eld's-Brow Antlered deer
(Cervus eldi thamin), aged over 1.5 years, to define their mean hematological
values (packed cell volume and hemoglobin) and mean plasma biochemical
parameters. Male deer had a significantly higher plasma glucose level and
aspartate aminotransferase activity than female deer.
PMID- 10676898
TI - Sequence analysis of the genes encoding the phosphoprotein of recent isolates of
canine distemper virus in Japan.
AB - The nucleotide sequences of the phosphoprotein (P) of canine distemper virus
(CDV) strains isolated between 1992 and 1996 in Japan were determined. This is
the first report of the complete sequences of the P genes of recently prevalent
CDV strains. The deduced amino acid sequences of the P, C and V proteins showed
that in the new Japanese isolates, these proteins have approximately 93%, 90-91%
and 92% identities with those of the Onderstepoort vaccine strain, respectively.
The predicted functional regions were conserved. RNA editing resulting in a shift
to the open reading frame (ORF) of the V protein was shown to occur with the same
efficiency in both the field isolates and vaccine strain.
PMID- 10676899
TI - Surgical repair of a depressed fracture in a green sea turtle, Chelonia mydas.
AB - Sea turtles are considered to be endangered species. A depressed fracture of a 35
kg green sea turtle was treated surgically. Isoflurane was used for induction and
maintenance of anesthesia. Slow induction of and slow recovery from anesthesia
was remarkable. After the operation, there was an improvement of general status,
but head tilt and weakness of the left limbs persisted. As the turtle did not
eat, force feeding using stomach tube was performed. The turtle died at about 6
months after the surgery.
PMID- 10676900
TI - Experimental reinfection with homologous porcine reproductive and respiratory
syndrome virus in SPF pigs.
AB - The present examination was conducted to determine if the pigs infected with one
strain of porcine reproductive and respiratory syndrome virus (PRRSV) would be
protected against a subsequent homologous virus challenge. Sixteen 4-week-old SPF
pigs were assigned to 2 experimental groups A and B. The pigs in group A were
inoculated with 10(6.5) TCID50 of PRRSV by intranasal route. On 77 days post
inoculation (PI), pigs in groups A and B were similarly inoculated with same
virus. After the secondary inoculation, the pigs in group A didn't show any
clinical sign including pyrexia and reduction of white blood cell (WBC) number.
Viremia was detected only on 3 days PI with low virus titer and any virus was not
recovered from serum and tissues at the time of necropsy on 14 or 28 days PI. In
contrast, pigs in group B showed pyrexia for 14 days and reduction of WBC number
on 3 days PI. Viremia was detected between 3 and 28 days PI, and virus was
isolated from several tissues of all pigs. These results indicate that previous
exposure to PRRSV can prevent development of clinical signs and reduce virus
proliferation in pigs after subsequent infection with the homologous PRRSV.
PMID- 10676901
TI - Examination of quantitative analysis and measurement of the regurgitation rate in
mitral valve regurgitation by the "proximal isovelocity surface area" method.
AB - In 33 dogs with mitral valve insufficiency (MR), assessed as severe by semi
quantitative color flow Doppler echocardiography, regurgitation volumes were
measured by the "Proximal Isovelocity Surface Area" (PISA) method. Good
correlation (p<0.01, r=0.97) between the regurgitation volumes determined by the
"PISA" and pulsed Doppler methods was confirmed. As evaluated by the "PISA"
method, regurgitation rates in the 32 dogs with measurable regurgitation volumes
ranged from 23 to 73%, with a mean of 51.6 +/- 11.8%. Regurgitation volumes
ranged from 3.3 to 32 ml, with a mean of 8.4 +/- 6.4 ml.
PMID- 10676902
TI - Bone marrow necrosis in a cat infected with feline leukemia virus.
AB - A one-year old castrated male cat was admitted to the hospital with vomiting and
diarrhea. Laboratory examination revealed pancytopenia and positive for FeLV
antigen. A bone marrow examination indicated necrosis of the nucleated cells.
Based on these findings, the cat was diagnosed as bone marrow necrosis.
Pancytopenia was effectively treated with corticosteroids. Re-examination of the
bone marrow confirmed a recovery of normal hematopoietic cells with a
infiltration of many macrophages. It is strongly suspected that the bone marrow
necrosis in this case could be associated with a bone marrow suppression due to
FeLV infection.
PMID- 10676903
TI - Effects of perineural capsaicin treatment on compound action potentials of
superior laryngeal nerve afferents in sevoflurane-anesthetized dogs.
AB - Effects of perineural capsaicin (CAPS) treatment on compound action potentials of
the superior laryngeal nerve (SLN) afferents were studied in 6 sevoflurane
anesthetized dogs. Perineural CAPS (100 microg/ml) to the bilateral SLNs reduced
(P<0.01) the peak and integral amplitudes of the C-wave of the compound action
potential. By contrast, the perineural CAPS had no effect on the A-wave component
(P>0.05). Removal of the perineural CAPS recovered the C-wave to pretreatment
level. The perineural CAPS treatment selectively blocks C-wave compound action
potentials of the SLN afferents, providing a useful tool for studies of laryngeal
C-fibers in respiratory physiology.
PMID- 10676904
TI - Effect of medium change on the development of in vitro matured and fertilized
bovine oocytes cultured in medium containing amino acids.
AB - Bovine in vitro matured and fertilized oocytes were cultured for 153 hr in groups
of 3 or 30 in 30 microl of modified synthetic oviduct fluid medium supplemented
with amino acids. The concentration of ammonium in culture medium at 153 hr of
culture was significantly decreased by medium change at 72 hr of culture.
However, regardless of embryo density, medium change had no beneficial or
detrimental effect on the development of bovine embryos. Increase in the
development to blastocysts and production of ammonium were observed when embryos
were cultured in groups of 30. These results indicated that the ammonium
concentration detected in this culture system has a negligible effect on the
development of bovine embryos to blastocysts.
PMID- 10676905
TI - Melanotic neurofibroma in a steer.
AB - A melanotic neurofibroma in a steer was investigated histologically,
immunohistochemically and ultrastructurally. A very large tumor mass was located
in the region of the head and right cheek. The tumor tissue consisted of an
admixture of cells resembling Schwann cells and spindle-shaped cells, and they
frequently contained melanin granules. Neoplastic Schwann cells were positive for
S100 protein, with variation in intensity of staining, but most spindled cells
were S100 negative. The tumor cells displayed ultrastructural features similar to
those of Schwann cells or perineurial cells. The presence of melanosomes in
varying stages of melanization in both cell types suggests that they have a
common origin. This is a tumor of neural crest origin showing schwannian and
perineurial differentiation, with ectopic production of melanin granules.
PMID- 10676906
TI - Introduction: acquired aplastic anemia.
PMID- 10676907
TI - Hematopoietic cell destruction by immune mechanisms in acquired aplastic anemia.
PMID- 10676908
TI - Myelodysplastic syndrome and aplastic anemia: distinct entities or diseases
linked by a common pathophysiology?
AB - It is often difficult to distinguish myelodysplastic syndrome (MDS) from severe
aplastic anemia (SAA) because both can present with profoundly hypocellular bone
marrows. The distinction matters because although both conditions are complicated
by pancytopenia, the risk of progression to acute leukemia is much greater in
MDS. This chapter reexamines the relationship between SAA and MDS. The clinical
and morphological features and pathophysiology of AA (including moderate and
severe forms of acquired AA) are compared with MDS and hypoplastic MDS, with
particular reference to new observations implicating autoimmune processes in both
conditions. SAA and hypoplastic MDS (HMDS) are discussed in the light of these
findings and attempts to separate nonevolving bone marrow failure syndromes from
marrow failure progressing to acute leukemia are reviewed. The weight of evidence
supports a common pathophysiology and, more speculatively, a common etiology for
at least some forms of AA and MDS.
PMID- 10676909
TI - Current status of allogeneic bone marrow transplantation in acquired aplastic
anemia.
AB - Bone marrow transplantation is an effective therapy for aplastic anemia. Infusion
of allogeneic hematopoietic stem cells after high-dose immune suppression
restores normal hematopoiesis in most patients and long-term follow-up has
confirmed the durability of donor hematopoiesis. However, success of this
approach is limited by transplant-related complications, such as graft failure,
graft-versus-host disease, and various organ toxicities. Long-term survival rates
range from less than 40% to more than 90% in reported series. These rates have
improved over the past 20 years due to significant reductions in graft-versus
host disease, interstitial pneumonitis, and early transplant-related mortality.
Most long-term survivors have excellent performance status. Late effects such as
cataracts, thyroid disorders, joint problems, and therapy-related cancers are
observed, especially in patients who received radiation for pretransplant
conditioning. Results are best in young patients transplanted with bone marrow
from a human leukocyte antigen (HLA)-identical sibling; early transplantation is
appropriate in this group. For older patients or those without an HLA-identical
related donor, transplants are better reserved for those who fail to respond to
immunosuppressive therapy.
PMID- 10676910
TI - Alternative-donor hematopoietic stem-cell transplantation for severe aplastic
anemia.
AB - Bone marrow transplantation (BMT) from a human leukocyte antigen (HLA)-matched
sibling is the treatment of choice in children and young adults with severe
aplastic anemia (SAA). However, because only 30% of patients have a suitable
donor, more aggressive nontransplant immunosuppressive regimens have been used,
with reasonable results. The use of mismatched family member and unrelated
donors, initially fraught with problems of nonengraftment and severe graft-versus
host disease (GVHD), has improved markedly over the past 10 years. The
establishment of donor registries, more precise HLA typing methods, and better
supportive care are significant factors in the improved outcomes. The challenge
for the future is to assemble the optimal combination of donor selection,
conditioning regimen, and GVHD prophylaxis to enhance disease-free survival.
These better outcomes should encourage the treating physician to consider stem
cell transplant at an earlier stage of disease.
PMID- 10676911
TI - Immunosuppressive treatment of aplastic anemia with antithymocyte globulin and
cyclosporine.
AB - Immunosuppression is the treatment modality for the majority of patients with
aplastic anemia, most of whom are not candidates for allogeneic stem-cell
transplantation. Antithymocyte globulin (ATG) or antilymphocyte globulin (ALG)
have proven to be essential components of all regimens. Initial response rates
can be improved by the addition of cyclosporine A (CsA), and this combination has
become the standard of care for appropriate patients. Several new approaches to
immunosuppression are being studied, including the optimal timing of
administration of these drugs, the use of novel immunosuppressive agents, and the
addition of early- and late-acting hematopoietic growth factors.
PMID- 10676912
TI - Treatment of acquired severe aplastic anemia: bone marrow transplantation
compared with immunosuppressive therapy--The European Group for Blood and Marrow
Transplantation experience.
AB - Patients with severe aplastic anemia (SAA) can be successfully treated with bone
marrow transplantation (BMT) or immunosuppressive therapy (IS). The current
outcome using both forms of therapy among 3,669 patients treated in Europe
between 1976 and 1998 is reviewed. Significant progress has been made and the
overall risk of failure is now low, with survival rates greater than 80% for both
treatments. Chronic graft-versus-host disease (GvHD) remains a problem for BMT
patients, and carries a high risk of lethal complications. On the other hand, IS
patients are exposed to late failure due to relapse or clonal/malignant diseases.
First-line BMT from identical siblings is compared with IS therapy in an intent
to-treat analysis of 1,765 patients, regardless of subsequent transplant status.
The outcome of SAA patients has improved considerably over time and is influenced
by patient variables such as severity of the disease and age, but also by the
choice of the initial treatment.
PMID- 10676913
TI - Hematopoietic growth factors in the pathogenesis and for the treatment of
aplastic anemia.
AB - The production and release of hematopoietic growth factors from bone marrow
stromas established in vitro from patients with aplastic anemia is normal or
increased. Addition of hematopoietic growth factors to aplastic anemia bone
marrow cells results in only modest increases in colony growth, with the
exception of granulocyte colony-stimulating factor (G-CSF), which corrects their
impaired cloning efficiency to normal. Most clinical data on the use of
hematopoietic growth factors in aplastic anemia have derived from uncontrolled
and small single-arm studies or case reports. Sustained trilineage hematologic
responses have not been observed when hematopoietic growth factors have been used
alone or in combination. Serious side effects have been reported for most of the
hematopoietic growth factors in patients with aplastic anemia, with the exception
of G-CSF. There is a major concern that they may further increase the risk of
clonal disorders such as myelodysplastic syndrome (MDS) and acute myeloid
leukemia (AML). Hematopoietic growth factors should not be used alone in newly
diagnosed patients as specific treatment for aplastic anemia, and their use in
combination with immunosuppressive therapy should be confined to multicenter,
prospective randomized studies.
PMID- 10676914
TI - Late clonal diseases of treated aplastic anemia.
AB - Recent progress in the treatment of aplastic anemia has dramatically changed the
previously grim prognosis for these patients. Improvements in bone marrow
transplantation and immunosuppression have increased the number of long-term
survivors so that immediate survival is no longer the sole concern. Here, we
review the major clinical studies and summarize recent analyses of risk factors
for developing paroxysmal nocturnal hemoglobinuria (PNH), myelodysplastic
syndrome (MDS), acute leukemia, or solid tumor after treatment for aplastic
anemia. We also examine biologic clues that may shed light on the
interrelationship between aplastic anemia and clonal diseases.
PMID- 10676915
TI - Cyclophosphamide and other new agents for the treatment of severe aplastic
anemia.
AB - Severe aplastic anemia (SAA) has a poor prognosis in the absence of treatment.
Current accepted therapeutic strategies include allogeneic stem-cell
transplantation and immunosuppression, both resulting in long-term survival in
the majority of patients. Although human leukocyte antigen (HLA)-matched sibling
stem-cell transplantation is highly effective, the 25% probability of finding a
suitable sibling donor within a family renders this approach available to only a
minority of patients. Transplantation using HLA-matched, unrelated donors carries
a high risk of treatment failure along with considerable toxicity. While combined
immunosuppression with both antithymocyte globulin (ATG) and cyclosporine A (CSA)
produces hematologic improvement in most patients, relapse is common. Late
evolution of aplastic anemia to other serious hematologic disorders, including
paroxysmal nocturnal hemoglobinuria (PNH), myelodysplasia, and acute leukemia, is
also a significant problem following treatment with ATG/CSA. Recently, results of
immunosuppression in SAA with another potent immunosuppressive agent,
cyclophosphamide, were reported in a small number of patients. The overall
response rate was similar to that seen with ATG/CSA, but relapse and late clonal
disease were not observed during a long period of follow-up. A larger randomized
trial comparing sustained hematologic response rates to either conventional
immunosuppression with ATG/CSA or high-dose cyclophosphamide and CSA is now
underway; secondary end points include response duration, event-free survival,
and overall survival. Additionally, a number of protocols designed to test the
efficacy of alternative immunosuppressive or immunomodulatory agents are being
developed.
PMID- 10676916
TI - Splenectomy-sparing strategies for the treatment and long-term maintenance of
chronic idiopathic (immune) thrombocytopenic purpura.
AB - Patients with idiopathic thrombocytopenic purpura (ITP) have vulnerability to
additional bleeding, leaving them susceptible to severe hemorrhaging. Low
platelet counts contribute to this rare, but significant outcome, but may not be
the sole determinant. Although the only current treatment of ITP felt to be
curative is surgical removal of the spleen, the long-term outcome for these
patients is not well defined. Our group Investigated the use of Intravenous gamma
globulin in the treatment of children with chronic ITP as a means to defer
splenectomy. A variation of this approach uses anti-D to block splenic
macrophages with antibody-coated red blood cells. There may be a correlation
between response to anti-D and response to splenectomy in adults with ITP.
Because the long-term results of splenectomy are not well defined, additional
clinical studies are warranted. Questions requiring further study Include whether
repeated Infusions of anti-D could allow the postponement and ultimate avoidance
of splenectomy and whether the role of anti-D may be for pregnant women who are
not readily eligible for splenectomy. Such an analysis should include information
on the long-term outcome of splenectomy as well as information on whether
patients have a durable improvement. Such studies about the potential outcomes of
splenectomy and of avoidance of splenectomy will help identify new treatment
strategies that may help to eliminate the need for this procedure in patients
with chronic ITP.
PMID- 10676917
TI - The pathogenesis of chronic immune (idiopathic) thrombocytopenic purpura.
AB - Chronic Immune (idiopathic) thrombocytopenic purpura (ITP) is an autoimmune
disorder in which antiplatelet autoantibody induces platelet destruction.
Platelet surface membrane proteins become antigenic, stimulating the immune
system to produce autoantibody. The initial antigenic response probably occurs in
the spleen, inducing autoantibody production followed by stimulation of other
antibody-producing tissues, particularly the bone marrow. Autoantibodies against
either platelet glycoprotein (GP)IIb/IIIa or GPIb/IX are produced by about 75% of
ITP patients and can be detected using antigen-specific assays. The spleen is the
major site of platelet destruction in ITP because of its unique milieu. About one
third of the platelet mass is present in the spleen at all times, where the local
production of antiplatelet antibody leads to high autoantibody concentrations.
These antibody-sensitized platelets circulate slowly through the phagocytic cell
rich spleen, resulting in their destruction. Since autoantibody binds to both
platelets and megakaryocytes, both platelet destruction and inhibition of
thrombopoiesis may be of importance in the pathogenesis of chronic ITP.
PMID- 10676918
TI - The spleen and splenectomy in immune (idiopathic) thrombocytopenic purpura.
AB - The benefits of surgical splenectomy in patients with immune (Idiopathic)
thrombocytopenia purpura (ITP) probably reflect the combined effects of
eliminating a source of antiplatelet antibody synthesis as well as the primary
site of platelet destruction. The recent availability of intravenous Rho(D)
Immune globulin (WinRho SDF; Nabi, Boca Raton, FL) presents an opportunity to
extend the duration of nonsurgical (spleen-sparing) management of chronic ITP by
inducing reversible Fc blockade. While new methods for laparoscopic splenectomy
may offer improved surgical outcomes and reduced costs for ITP patients in the
near-term, the long-term consequences of splenectomy remain to be determined.
Partial splenectomy has been shown to be effective in the management of anemia in
hereditary spherocytosis and elliptocytosis, while preserving vital splenic
phagocytic and immune functions. The concept that cell destruction occurs in
reticuloendothelial cells has been updated with recognition that the mononuclear
phagocyte is neither a reticular nor an endothelial cell. Immune phagocytosis is
now understood to be mediated by macrophage IgG Fc and complement receptors. A
key factor for devising a strategy for selecting medical or surgical splenectomy,
or postponing splenectomy, is an assessment of the relative importance of splenic
immune versus phagocytic function in the pathogenesis of ITP.
PMID- 10676919
TI - The spleen: anatomy and anatomical function.
AB - In this review, our knowledge concerning the structure and function of the spleen
is summarized. The unique architecture of the spleen allows for interactions
between the circulatory, reticuloendothelial, and immune systems. Based on these
interactions in conjunction with its microanatomy, the spleen is able to maintain
the integrity of the blood and respond to circulating antigens. However, this can
be a double-edged sword in the case of patients suffering from autoimmune
diseases such as immune thrombocytopenic purpura since the spleen can be the site
of both antibody production and circulating cell destruction.
PMID- 10676920
TI - Long-term outcome of splenectomy for idiopathic thrombocytopenic purpura.
AB - Idiopathic thrombocytopenic purpura (ITP) is an illness of primary acquired
thrombocytopenia occurring in the absence of marrow failure. Splenectomy was
first used as a treatment for ITP in 1913. However, with the realization that
opsonin (critical for the optimal killing of invasive micro-organisms by white
blood cells) is manufactured only in the spleen, spontaneous splenic removal was
reevaluated and questioned. Splenectomy has a success rate that remains nearly
identical (about 50% to 60%) whether it is performed soon after diagnosis or
several months or years later. As yet, there is no consistently effective method
to predict an individual ITP patient's response to splenectomy. As the time since
splenectomy increases, however, the rate of excellent response decreases. Despite
pneumococcal vaccination prior to splenectomy, fatal fulminant sepsis is an
omnipresent possibility. Because a number of published studies, including the
Johns Hopkins experience, have questioned the long-term outcome of splenectomy,
splenectomy should not be the first treatment option for ITP patients. It should
be performed only after all other therapeutic modalities have been exhausted, and
the patient has a platelet count less than 25,000/microL and is hemorrhaging.
Once patients have undergone splenectomy, they are Ineligible for potentially
excellent treatment such as anti-D globulin or oral tolerance therapy.
PMID- 10676921
TI - The potential for treatment of idiopathic thrombocytopenic purpura with anti-D to
prevent splenectomy: a predictive cost analysis.
AB - Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder affecting
both children and adults that can be manifested by severe bleeding episodes.
Adult ITP patients have a low rate of spontaneous remission, and symptomatic
patients commonly undergo splenectomy; however, maintenance therapy may increase
the rate of remission, allowing splenectomy to be avoided. Anti-D is a recently
licensed treatment for ITP that has the potential to delay, and possibly avoid,
the need for splenectomy. We used preliminary data from an ongoing clinical trial
to evaluate the costs involved in using anti-D therapy for 1 year with the intent
of avoiding the need for splenectomy. We accounted for different possible
outcomes at the completion of the clinical trial. An economic model with a
theoretical cohort of 100 patients was developed using the model of an ongoing
clinical trial. The average wholesale price was used to determine the cost of an
infusion of anti-D based on an average dose ($1,213 per infusion). The cost of
splenectomy was determined by a literature review ($16,000). Costs were
calculated for all known patient outcomes; where outcomes were unknown and likely
to vary, all possible outcomes were accounted for (splenectomy or no
splenectomy). In our theoretical cohort, 31 of 100 patients were taken off anti-D
and received splenectomy, 32 of 100 were stable after receiving anti-D and would
not need splenectomy, and 37 of 100 had Indeterminate outcomes after receiving
anti-D. When compared with the cost of the hypothetical scenario of initially
giving all 100 patients splenectomy ($1.6 million), a minimum of 47 patients
would have to avoid splenectomy to result in a cost savings for our cohort of 100
patients. The group of 47 patients avoiding splenectomy would be composed of the
32 patients comprising the stable group and at least 15 of the 37 patients
comprising the group with indeterminate outcomes. If all 37 of the patients in
the group with indeterminate outcomes avoid splenectomy, $363,000 and 69 spleens
would be saved. Our data suggest that in the phase III trial of maintenance anti
D therapy versus immediate splenectomy, anti-D therapy will be a cost-effective
option if 47% or more of patients avoid splenectomy.
PMID- 10676922
TI - Treatment options for chronic idiopathic (immune) thrombocytopenic purpura.
AB - The goal of treatment for idiopathic (immune) thrombocytopenic purpura (ITP) is
to prevent serious bleeding. Traditionally, corticosteroids have been used as
first-line therapy followed by splenectomy. Experience with splenectomy over 60
years shows that approximately two thirds of patients achieve normal platelet
counts during the initial observation, but that thrombocytopenia often recurs
with longer follow-up. We know that long-term use of corticosteroids can lead to
significant morbidities; there is no consensus regarding the appropriate timing
or indications for splenectomy. To address the Issue of appropriate use of
splenectomy, we designed a multicenter clinical trial that will randomize
patients to either standard care, involving prednisone followed by splenectomy,
or to a novel regimen of limited prednisone treatment followed by WinRho SDF
(Nabi, Boca Raton, FL) (anti-D) therapy to maintain the platelet count in a safe
range for 1 year. Anti-D can be administered easily in an outpatient setting with
few side effects and can provide predictable, transient increases in platelet
count. The hypothesis is that prolonged maintenance therapy with a nontoxic
regimen may increase the percentage of patients who will experience a spontaneous
remission from thrombocytopenia, thereby avoiding an invasive and permanent
surgical procedure, splenectomy, and its potentially life-threatening sequelae.
PMID- 10676923
TI - Treatment options for chronic immune (idiopathic) thrombocytopenia purpura in
children.
AB - Immune (idiopathic) thrombocytopenic purpura (ITP) in children is usually acute
and self-limiting, but may become chronic in 10% to 30% of patients. Salient
issues in the treatment of childhood chronic ITP (cITP) include the following:
the choice of immunomodulatory agent; the child's desire for unrestricted
physical activity; interventions to avoid or defer splenectomy; and, finally,
choosing when (and how) to perform splenectomy. Treatment for children with cITP
during childhood usually is extrapolated from that for acute ITP. Treatment with
pooled intravenous immunoglobulin (IVIg) and anti-D immunoglobulin often gives an
acute response followed by a predictable decay of platelet count. Corticosteroids
usually lead to a platelet increase; however, the associated adverse effects of
chronic usage are generally unsatisfactory for most children and adolescents.
With pulsed, high-dose corticosteroids, a durable platelet response is the
exception, not the rule. More aggressive immunosuppression is usually reserved
for patients who are symptomatic and refractory to the above treatments,
Including splenectomy. Although the estimated success rate ranges from 70% to
90%, the long-term outcome of splenectomy in children with cITP in not well
described. In addition, the risk of fatal postsplenectomy infections is
significant. A familiar initial strategy among pediatric hematologists thus
involves deferral of splenectomy with the reasonable possibility of spontaneous
recovery. Corticosteroids, anti-D, and IVIg are effective, temporizing medical
alternatives to splenectomy in treating cITP in children. Quality-of-life
measurements in children with cITP may help to stimulate the development of new
approaches.
PMID- 10676924
TI - Splenectomy-sparing, long-term maintenance with anti-D for chronic immune
(idiopathic) thrombocytopenic purpura: the New York Hospital experience.
AB - For nonsplenectomized children and adults with chronic or acute immune
(idiopathic) thrombocytopenic purpura (ITP), anti-D has been shown to be a safe
and effective treatment, providing hemostatic platelet increases in more than 70%
of patients. Children had the best results, but all patient groups responded. In
our recently published series, the effect of anti-D therapy lasted for more than
21 days in 50% of the responders and for more than 1 month in 37%. The use of
anti-D as maintenance therapy was evaluated in a subset of patients. Of those who
responded to the initial anti-D infusion, 79 patients (44 children, 35 adults)
received 3 consecutive treatments. There were no significant differences in the
responses after each infusion. Fifty-eight patients responded to all 3
treatments; of those, 20 (9 children, 11 adults) continued anti-D therapy,
receiving an average of 18 infusions each (range, 10 to 36). The overall response
rate was 86%. The ease of administration, duration of effect, and infrequent
development of tachyphylaxis make anti-D an attractive alternative for
maintenance therapy, particularly for children with ITP who have a high rate of
spontaneous remissions. Use of anti-D as a means of spearing the spleen or, at
least, postponing splenectomy should now be considered as a clinical option in
the management of adult patients with chronic ITP.
PMID- 10676926
TI - Seeds of consensus.
PMID- 10676925
TI - Use of anti-D in immune thrombocytopenic purpura as a means to prevent
splenectomy: case reports from two University Hospital Medical Centers.
AB - Presented here are 16 case studies of adults with immune (idiopathic)
thrombocytopenic purpura (ITP); 5 were treated at Hackensack University Medical
Center (HUMC), Hackensack, NJ, and 11 were treated at the Allegheny University
Hospital (AUH), Medical College of Pennsylvania. Four of the 5 patients at HUMC
had initial transient responses to intravenous immunoglobulin G (IVIg) therapy
and required large doses of corticosteroids to maintain platelet counts over
50,000 microL. One elderly patient with systemic lupus erythematosus (SLE) had
been treated unsuccessfully with corticosteroids and immunosuppressants to
maintain her platelet count over 50,000 microL. All 5 patients were given 1 or 2
doses of anti-D at 50 microg/kg, leading to complete resolution of ITP. Following
anti-D therapy, patients were tapered off corticosteroids and currently remain in
complete remission with platelet counts over 100,000/ microL. The mechanism of
action of anti-D in ITP remains unclear and requires further study. Treatment of
the 11 patients at AUH began with corticosteroids, which resulted in no durable
therapeutic response. Anti-D was then given at 50 microg/kg, and this provoked an
excellent response with a prompt recovery of platelet levels to 100,000/ microL,
after which active treatment was halted. Patients were monitored by direct office
visit every 3 months unless a clinical indication required an earlier return. If
the patient's platelets dropped below 100,000/ microL, they were first given
prednisone. As of the last follow-up, all 11 patients remain stable and no
patients have required splenectomy.
PMID- 10676927
TI - Livermore plans radical rescue for 'mismanaged' laser facility
PMID- 10676928
TI - Japan may allow human embryo stem-cell research.
PMID- 10676929
TI - Change of government bodes well for NZ science funding.
PMID- 10676930
TI - WWW project aims to address worldwide decline in amphibians.
PMID- 10676931
TI - Anderson steps down from Wellcome over Oxford row.
PMID- 10676932
TI - IBM joins genomics mapping consortium.
PMID- 10676933
TI - German science starts facing up to its historical amnesia.
PMID- 10676934
TI - Apathy rewards misconduct--and everybody suffers.
PMID- 10676935
TI - End of impact factors?
PMID- 10676936
TI - Nucleic acids revelation delayed by a sceptic.
PMID- 10676938
TI - Decline of the generalist
PMID- 10676937
TI - And should be treated the same as genomics.
PMID- 10676939
TI - From Caribbean to Clementine.
PMID- 10676940
TI - Fluff balls of fire
PMID- 10676941
TI - Survey flights in honeybees.
PMID- 10676942
TI - Electrons in the looking glass
PMID- 10676943
TI - Gene expression in diagnosis.
PMID- 10676944
TI - Plant ecology. Alien invaders.
PMID- 10676945
TI - Hydrology. The sting in a fractal tail
PMID- 10676946
TI - Huntington's disease. A predictor of pathology.
PMID- 10676947
TI - Optical control of reactions
PMID- 10676948
TI - Longevity record for deep-sea invertebrate.
PMID- 10676949
TI - Mitochondria and the death of oocytes.
PMID- 10676950
TI - Demethylation of the zygotic paternal genome.
PMID- 10676951
TI - Distinct types of diffuse large B-cell lymphoma identified by gene expression
profiling.
AB - Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's
lymphoma, is clinically heterogeneous: 40% of patients respond well to current
therapy and have prolonged survival, whereas the remainder succumb to the
disease. We proposed that this variability in natural history reflects
unrecognized molecular heterogeneity in the tumours. Using DNA microarrays, we
have conducted a systematic characterization of gene expression in B-cell
malignancies. Here we show that there is diversity in gene expression among the
tumours of DLBCL patients, apparently reflecting the variation in tumour
proliferation rate, host response and differentiation state of the tumour. We
identified two molecularly distinct forms of DLBCL which had gene expression
patterns indicative of different stages of B-cell differentiation. One type
expressed genes characteristic of germinal centre B cells ('germinal centre B
like DLBCL'); the second type expressed genes normally induced during in vitro
activation of peripheral blood B cells ('activated B-like DLBCL'). Patients with
germinal centre B-like DLBCL had a significantly better overall survival than
those with activated B-like DLBCL. The molecular classification of tumours on the
basis of gene expression can thus identify previously undetected and clinically
significant subtypes of cancer.
PMID- 10676952
TI - Quantum mirages formed by coherent projection of electronic structure
AB - Image projection relies on classical wave mechanics and the use of natural or
engineered structures such as lenses or resonant cavities. Well-known examples
include the bending of light to create mirages in the atmosphere, and the
focusing of sound by whispering galleries. However, the observation of analogous
phenomena in condensed matter systems is a more recent development, facilitated
by advances in nanofabrication. Here we report the projection of the electronic
structure surrounding a magnetic Co atom to a remote location on the surface of a
Cu crystal; electron partial waves scattered from the real Co atom are coherently
refocused to form a spectral image or 'quantum mirage'. The focusing device is an
elliptical quantum corral, assembled on the Cu surface. The corral acts as a
quantum mechanical resonator, while the two-dimensional Cu surface-state
electrons form the projection medium. When placed on the surface, Co atoms
display a distinctive spectroscopic signature, known as the many-particle Kondo
resonance, which arises from their magnetic moment. By positioning a Co atom at
one focus of the ellipse, we detect a strong Kondo signature not only at the
atom, but also at the empty focus. This behaviour contrasts with the usual
spatially-decreasing response of an electron gas to a localized perturbation.
PMID- 10676953
TI - Experimental test of quantum nonlocality in three-photon Greenberger-Horne
Zeilinger entanglement
AB - Bell's theorem states that certain statistical correlations predicted by quantum
physics for measurements on two-particle systems cannot be understood within a
realistic picture based on local properties of each individual particle-even if
the two particles are separated by large distances. Einstein, Podolsky and Rosen
first recognized the fundamental significance of these quantum correlations
(termed 'entanglement' by Schrodinger) and the two-particle quantum predictions
have found ever-increasing experimental support. A more striking conflict between
quantum mechanical and local realistic predictions (for perfect correlations) has
been discovered; but experimental verification has been difficult, as it requires
entanglement between at least three particles. Here we report experimental
confirmation of this conflict, using our recently developed method to observe
three-photon entanglement, or 'Greenberger-Horne-Zeilinger' (GHZ) states. The
results of three specific experiments, involving measurements of polarization
correlations between three photons, lead to predictions for a fourth experiment;
quantum physical predictions are mutually contradictory with expectations based
on local realism. We find the results of the fourth experiment to be in agreement
with the quantum prediction and in striking conflict with local realism.
PMID- 10676954
TI - Ball lightning caused by oxidation of nanoparticle networks from normal lightning
strikes on soil
AB - Observations of ball lightning have been reported for centuries, but the origin
of this phenomenon remains an enigma. The 'average' ball lightning appears as a
sphere with a diameter of 300 mm, a lifetime of about 10 s, and a luminosity
similar to a 100-W lamp. It floats freely in the air, and ends either in an
explosion, or by simply fading from view. It almost invariably occurs during
stormy weather. Several energy sources have been proposed to explain the light,
but none of these models has succeeded in explaining all of the observed
characteristics. Here we report a model that potentially accounts for all of
those properties, and which has some experimental support. When normal lightning
strikes soil, chemical energy is stored in nanoparticles of Si, SiO or SiC, which
are ejected into the air as a filamentary network. As the particles are slowly
oxidized in air, the stored energy is released as heat and light. We investigated
this basic process by exposing soil samples to a lightning-like discharge, which
produced chain aggregates of nanoparticles: these particles oxidize at a rate
appropriate for explaining the lifetime of ball lightning.
PMID- 10676955
TI - Large-scale complementary integrated circuits based on organic transistors
AB - Thin-film transistors based on molecular and polymeric organic materials have
been proposed for a number of applications, such as displays and radio-frequency
identification tags. The main factors motivating investigations of organic
transistors are their lower cost and simpler packaging, relative to conventional
inorganic electronics, and their compatibility with flexible substrates. In most
digital circuitry, minimal power dissipation and stability of performance against
transistor parameter variations are crucial. In silicon-based microelectronics,
these are achieved through the use of complementary logic-which incorporates both
p- and n-type transistors-and it is therefore reasonable to suppose that adoption
of such an approach with organic semiconductors will similarly result in reduced
power dissipation, improved noise margins and greater operational stability.
Complementary inverters and ring oscillators have already been reported. Here we
show that such an approach can realize much larger scales of integration (in the
present case, up to 864 transistors per circuit) and operation speeds of
approximately 1 kHz in clocked sequential complementary circuits.
PMID- 10676956
TI - Fractal stream chemistry and its implications for contaminant transport in
catchments
AB - The time it takes for rainfall to travel through a catchment and reach the stream
is a fundamental hydraulic parameter that controls the retention of soluble
contaminants and thus the downstream consequences of pollution episodes.
Catchments with short flushing times will deliver brief, intense contaminant
pulses to downstream waters, whereas catchments with longer flushing times will
deliver less intense but more sustained contaminant fluxes. Here we analyse
detailed time series of chloride, a natural tracer, in both rainfall and runoff
from headwater catchments at Plynlimon, Wales. We show that, although the
chloride concentrations in rainfall have a white noise spectrum, the chloride
concentrations in streamflow exhibit fractal 1/f scaling over three orders of
magnitude. The fractal fluctuations in tracer concentrations indicate that these
catchments do not have characteristic flushing times. Instead, their travel times
follow an approximate power-law distribution implying that they will retain a
long chemical memory of past inputs. Contaminants will initially be flushed
rapidly, but then low-level contamination will be delivered to streams for a
surprisingly long time.
PMID- 10676957
TI - Rapid diffusive infiltration of sodium into partially molten peridotite
AB - Recent seismological, geochemical and experimental observations suggest that, as
mantle peridotite melts, the resulting basaltic liquid forms an interconnected
network, culminating in the rapid ascent of the basalt relative to the
surrounding solid matrix. Mantle melting is therefore a polybaric process, with
melts produced over a range of pressures having differing chemical
characteristics. Modelling and peridotite-melting experiments designed to
simulate polybaric mantle melting generally assume that there is no interaction
between melts generated at greater pressures and the overlying solid mantle at
lower pressures. Beneath mid-ocean ridges, melts derived from greater depth are
probably channelized during ascent, so preventing direct re-equilibration with
shallow peridotite, as required by geochemical observations. I show here,
however, that sodium in ascending melts will quickly diffuse into the melt formed
within nearby peridotite at lower pressures. This process fundamentally changes
the manner by which the peridotite melts, and can account for both the creation
of silica-rich glass inclusions in mantle xenoliths and the anomalous melting
modes recorded by abyssal peridotites. Increased melting of lithosphere and
upwelling asthenosphere could result from this process without the need to invoke
higher mantle temperatures.
PMID- 10676958
TI - Oxygen-isotope evidence for recycled crust in the sources of mid-ocean-ridge
basalts
AB - Mid-ocean-ridge basalts (MORBs) are the most abundant terrestrial magmas and are
believed to form by partial melting of a globally extensive reservoir of
ultramafic rocks in the upper mantle. MORBs vary in their abundances of
incompatible elements (that is, those that partition into silicate liquids during
partial melting) and in the isotopic ratios of several radiogenic isotope
systems. These variations define a spectrum between 'depleted' and 'enriched'
compositions, characterized by respectively low and high abundances of
incompatible elements. Compositional variations in the sources of MORBs could
reflect recycling of subducted crustal materials into the source reservoir, or
any of a number of processes of intramantle differentiations. Variations in
(18)O/(16)O (principally sensitive to the interaction of rocks with the Earth's
hydrosphere) offer a test of these alternatives. Here we show that (18)O/(16)O
ratios of MORBs are correlated with aspects of their incompatible-element
chemistry. These correlations are consistent with control of the oxygen-isotope
and incompatible-element geochemistry of MORBs by a component of recycled crust
that is variably distributed throughout their upper mantle sources.
PMID- 10676959
TI - Quality of the fossil record through time.
AB - Does the fossil record present a true picture of the history of life, or should
it be viewed with caution? Raup argued that plots of the diversification of life
were an illustration of bias: the older the rocks, the less we know. The debate
was partially resolved by the observation that different data sets gave similar
patterns of rising diversity through time. Here we show that new assessment
methods, in which the order of fossils in the rocks (stratigraphy) is compared
with the order inherent in evolutionary trees (phylogeny), provide a more
convincing analytical tool: stratigraphy and phylogeny offer independent data on
history. Assessments of congruence between stratigraphy and phylogeny for a
sample of 1,000 published phylogenies show no evidence of diminution of quality
backwards in time. Ancient rocks clearly preserve less information, on average,
than more recent rocks. However, if scaled to the stratigraphic level of the
stage and the taxonomic level of the family, the past 540 million years of the
fossil record provide uniformly good documentation of the life of the past.
PMID- 10676960
TI - Ontogeny of orientation flight in the honeybee revealed by harmonic radar.
AB - Cognitive ethology focuses on the study of animals under natural conditions to
reveal ecologically adapted modes of learning. But biologists can more easily
study what an animal learns than how it learns. For example, honeybees take
repeated 'orientation' flights before becoming foragers at about three weeks of
age. These flights are a prerequisite for successful homing. Little is known
about these flights because orienting bees rapidly fly out of the range of human
observation. Using harmonic radar, we show for the first time a striking ontogeny
to honeybee orientation flights. With increased experience, bees hold trip
duration constant but fly faster, so later trips cover a larger area than earlier
trips. In addition, each flight is typically restricted to a narrow sector around
the hive. Orientation flights provide honeybees with repeated opportunities to
view the hive and landscape features from different viewpoints, suggesting that
bees learn the local landscape in a progressive fashion. We also show that these
changes in orientation flight are related to the number of previous flights taken
instead of chronological age, suggesting a learning process adapted to changes in
weather conditions, flower availability and the needs of bee colonies.
PMID- 10676961
TI - Myoglobin-like aerotaxis transducers in Archaea and Bacteria.
AB - Haem-containing proteins such as haemoglobin and myoglobin play an essential role
in oxygen transport and storage. Comparison of the amino-acid sequences of
globins from Bacteria and Eukarya suggests that they share an early common
ancestor, even though the proteins perform different functions in these two
kingdoms. Until now, no members of the globin family have been found in the third
kingdom, Archaea. Recent studies of biological signalling in the Bacteria and
Eukarya have revealed a new class of haem-containing proteins that serve as
sensors. Until now, no haem-based sensor has been described in the Archaea. Here
we report the first myoglobin-like, haem-containing protein in the Archaea, and
the first haem-based aerotactic transducer in the Bacteria (termed HemAT-Hs for
the archaeon Halobacterium salinarum, and HemAT-Bs for Bacillus subtilis). These
proteins exhibit spectral properties similar to those of myoglobin and trigger
aerotactic responses.
PMID- 10676962
TI - Motor disorder in Huntington's disease begins as a dysfunction in error feedback
control.
AB - A steady progression of motor dysfunction takes place in Huntington's disease
(HD). The origin of this disturbance with relation to the motor control process
is not understood. Here we studied reaching movements in asymptomatic HD gene
carriers (AGCs) and subjects with manifest HD. We found that movement jerkiness,
which characterizes the smoothness and efficiency of motion, was a sensitive
indicator of presymptomatic HD progression. A large fraction of AGCs displayed
elevated jerk even when more than seven years remained until predicted disease
onset. Movement termination was disturbed much more than initiation and was
highly variable from trial to trial. Analysis of this variability revealed that
the sensitivity of end-movement jerk to subtle, self-generated early-movement
errors was greater in HD subjects than in controls. Additionally, we found that
HD corrective responses to externally-generated force pulses were greatly
disturbed, indicating that HD subjects display aberrant responses to both
external and self-generated errors. Because feedback corrections are driven by
error and are delayed such that they predominantly affect movement termination,
these findings suggest that a dysfunction in error correction characterizes the
motor control deficit in early HD. This dysfunction may be observed years before
clinical disease onset and grows worse as the disease progresses.
PMID- 10676963
TI - A neuronal analogue of state-dependent learning.
AB - State-dependent learning is a phenomenon in which the retrieval of newly acquired
information is possible only if the subject is in the same sensory context and
physiological state as during the encoding phase. In spite of extensive
behavioural and pharmacological characterization, no cellular counterpart of this
phenomenon has been reported. Here we describe a neuronal analogue of state
dependent learning in which cortical neurons show an acetylcholine-dependent
expression of an acetylcholine-induced functional plasticity. This was
demonstrated on neurons of rat somatosensory 'barrel' cortex, whose tunings to
the temporal frequency of whisker deflections were modified by cellular
conditioning. Pairing whisker stimulation with acetylcholine applied
iontophoretically yielded selective lasting modification of responses, the
expression of which depended on the presence of exogenous acetylcholine.
Administration of acetylcholine during testing revealed frequency-specific
changes in response that were not expressed when tested without acetylcholine or
when the muscarinic antagonist, atropine, was applied concomitantly. Our results
suggest that both acquisition and recall can be controlled by the cortical
release of acetylcholine.
PMID- 10676964
TI - Modulation of A-type potassium channels by a family of calcium sensors.
AB - In the brain and heart, rapidly inactivating (A-type) voltage-gated potassium
(Kv) currents operate at subthreshold membrane potentials to control the
excitability of neurons and cardiac myocytes. Although pore-forming alpha
subunits of the Kv4, or Shal-related, channel family form A-type currents in
heterologous cells, these differ significantly from native A-type currents. Here
we describe three Kv channel-interacting proteins (KChIPs) that bind to the
cytoplasmic amino termini of Kv4 alpha-subunits. We find that expression of KChIP
and Kv4 together reconstitutes several features of native A-type currents by
modulating the density, inactivation kinetics and rate of recovery from
inactivation of Kv4 channels in heterologous cells. All three KChIPs co-localize
and co-immunoprecipitate with brain Kv4 alpha-subunits, and are thus integral
components of native Kv4 channel complexes. The KChIPs have four EF-hand-like
domains and bind calcium ions. As the activity and density of neuronal A-type
currents tightly control responses to excitatory synaptic inputs, these KChIPs
may regulate A-type currents, and hence neuronal excitability, in response to
changes in intracellular calcium.
PMID- 10676965
TI - Slowed recovery of rod photoresponse in mice lacking the GTPase accelerating
protein RGS9-1.
AB - Timely deactivation of the alpha-subunit of the rod G-protein transducin
(Galphat) is essential for the temporal resolution of rod vision. Regulators of G
protein signalling (RGS) proteins accelerate hydrolysis of GTP by the alpha
subunits of heterotrimeric G proteins in vitro. Several retinal RGS proteins can
act in vitro as GTPase accelerating proteins (GAP) for Galphat. Recent
reconstitution experiments indicate that one of these, RGS9-1, may account for
much of the Galphat GAP activity in rod outer segments (ROS). Here we report that
ROS membranes from mice lacking RGS9-1 hydrolyse GTP more slowly than ROS
membranes from control mice. The Gbeta5-L protein that forms a complex with RGS9
1 was absent from RGS9-/- retinas, although Gbeta5-L messenger RNA was still
present. The flash responses of RGS9-/- rods rose normally, but recovered much
more slowly than normal. We conclude that RGS9-1, probably in a complex with
Gbeta5-L, is essential for acceleration of hydrolysis of GTP by Galphat and for
normal recovery of the photoresponse.
PMID- 10676966
TI - Food and metabolic signalling defects in a Caenorhabditis elegans serotonin
synthesis mutant.
AB - The functions of serotonin have been assigned through serotonin-receptor-specific
drugs and mutants; however, because a constellation of receptors remains when a
single receptor subtype is inhibited, the coordinate responses to modulation of
serotonin levels may be missed. Here we report the analysis of behavioural and
neuroendocrine defects caused by a complete lack of serotonin signalling.
Analysis of the C. elegans genome sequence showed that there is a single
tryptophan hydroxylase gene (tph-1)-the key enzyme for serotonin biosynthesis.
Animals bearing a tph-1 deletion mutation do not synthesize serotonin but are
fully viable. The tph-1 mutant shows abnormalities in behaviour and metabolism
that are normally coupled with the sensation and ingestion of food: rates of
feeding and egg laying are decreased; large amounts of fat are stored;
reproductive lifespan is increased; and some animals arrest at the metabolically
inactive dauer stage. This metabolic dysregulation is, in part, due to
downregulation of transforming growth factor-beta and insulin-like neuroendocrine
signals. The action of the C. elegans serotonergic system in metabolic control is
similar to mammalian serotonergic input to metabolism and obesity.
PMID- 10676967
TI - Evidence for stabilizing selection in a eukaryotic enhancer element.
AB - Eukaryotic gene expression is mediated by compact cis-regulatory modules, or
enhancers, which are bound by specific sets of transcription factors. The
combinatorial interaction of these bound transcription factors determines time-
and tissue-specific gene activation or repression. The even-skipped stripe 2
element controls the expression of the second transverse stripe of even-skipped
messenger RNA in Drosophila melanogaster embryos, and is one of the best
characterized eukaryotic enhancers. Although even-skipped stripe 2 expression is
strongly conserved in Drosophila, the stripe 2 element itself has undergone
considerable evolutionary change in its binding-site sequences and the spacing
between them. We have investigated this apparent contradiction, and here we show
that two chimaeric enhancers, constructed by swapping the 5' and 3' halves of the
native stripe 2 elements of two species, no longer drive expression of a reporter
gene in the wildtype pattern. Sequence differences between species have
functional consequences, therefore, but they are masked by other co-evolved
differences. On the basis of these results, we present a model for the evolution
of eukaryotic regulatory sequences.
PMID- 10676968
TI - Structure of human guanylate-binding protein 1 representing a unique class of GTP
binding proteins.
AB - Interferon-gamma is an immunomodulatory substance that induces the expression of
many genes to orchestrate a cellular response and establish the antiviral state
of the cell. Among the most abundant antiviral proteins induced by interferon
gamma are guanylate-binding proteins such as GBP1 and GBP2. These are large GTP
binding proteins of relative molecular mass 67,000 with a high-turnover GTPase
activity and an antiviral effect. Here we have determined the crystal structure
of full-length human GBP1 to 1.8 A resolution. The amino-terminal 278 residues
constitute a modified G domain with a number of insertions compared to the
canonical Ras structure, and the carboxy-terminal part is an extended helical
domain with unique features. From the structure and biochemical experiments
reported here, GBP1 appears to belong to the group of large GTP-binding proteins
that includes Mx and dynamin, the common property of which is the ability to
undergo oligomerization with a high concentration-dependent GTPase activity.
PMID- 10676969
TI - Alternative modular polyketide synthase expression controls macrolactone
structure.
AB - Modular polyketide synthases are giant multifunctional enzymes that catalyse the
condensation of small carboxylic acids such as acetate and propionate into
structurally diverse polyketides that possess a spectrum of biological
activities. In a modular polyketide synthase, an enzymatic domain catalyses a
specific reaction, and three to six enzymatic domains involved in a condensation
processing cycle are organized into a module. A fundamental aspect of a modular
polyketide synthase is that its module arrangement linearly specifies the
structure of its polyketide product. Here we report a natural example in which
alternative expression of the pikromycin polyketide synthase results in the
generation of two macrolactone structures. Expression of the full-length modular
polyketide synthase PikAIV in Streptomyces venezuelae generates the 14-membered
ring macrolactone narbonolide, whereas expression of the amino-terminal truncated
form of PikAIV leads to 'skipping' of the final condensation cycle in polyketide
biosynthesis to generate the 12-membered ring macrolactone 10-deoxymethynolide.
Our findings provide insight into the structure and function of modular
polyketide synthases, as well as a new set of tools to generate structural
diversity in polyketide natural products.
PMID- 10676970
TI - From the CDC: Syphilis elimination: history in the making--opening remarks.
PMID- 10676971
TI - From the CDC: Syphilis elimination: history in the making--closing remarks.
PMID- 10676972
TI - Syphilis in Atlanta during an era of declining incidence.
AB - BACKGROUND: Syphilis transmission in Atlanta is ongoing despite declining
incidence. OBJECTIVES: To identify risk factors and missed opportunities for
prevention. STUDY DESIGN: A case-control study design was used. Twenty-five
sexually transmitted disease (STD) clinic patients with primary or secondary
syphilis by polymerase chain reaction and serology and 49 matched controls were
interviewed. RESULTS: Persons with syphilis more frequently had HIV infection
(24% versus 2%; P = 0.005), crack-using sex partners (52% versus 18%; odds ratio
[OR] = 5.1; 95% CI = 1.7-15.5), and a history of incarceration (80% versus 57%;
OR = 3.0; CI = 1.0-9.3). Many cases (48%) and controls (31%) had received drug
abuse treatment. Only 40% of previously incarcerated patients and 74% of those
with a history of drug treatment reported receiving STD/HIV education in those
settings. Among all patients reporting recent HIV education, 41% were told about
STD recognition and treatment. Unprotected sex and delay in seeking care were
common. CONCLUSION: To prevent syphilis and associated HIV, more extensive STD
education is needed in jails and drug-treatment centers.
PMID- 10676973
TI - Effect of chlorhexidine on genital microflora, Neisseria gonorrhoeae, and
Trichomonas vaginalis in vitro.
AB - BACKGROUND: Chlorhexidine is a disinfectant that has been used in skin and mouth
washes and as a preservative in some vaginal lubricants. A gel containing 0.25%
chlorhexidine gluconate has been found to be effective against Chlamydia
trachomatis in vitro and in animal models. Applied vaginally, 5 g of this gel
could achieve vaginal fluid concentrations of < or = 1250 microg/ml. GOAL: To
test the in vitro activity of chlorhexidine in a gel over a pH range of 4 to 8 in
the presence or absence of blood. STUDY DESIGN: Organisms were exposed to
chlorhexidine for 30 minutes to 2 hours, and the minimum cidal concentration
(MCC) was calculated. RESULTS: The MCC for Neisseria gonorrhoeae was 25 microg/ml
at 30 minutes and 12.5 microg/ml at 1 to 2 hours of exposure, whereas the MCC for
Trichomonas vaginalis was 1250 microg/ml. Chlorhexidine was more active at pH 8
than pH 4, and less active in the presence of blood. The MCC for Lactobacillus
crispatus was 1250 microg/ml at pH 4 and only 125 microg/ml at pH 8. CONCLUSIONS:
Based on its in vitro activity, chlorhexidine may be an appropriate topical
microbicide for prevention of gonorrhea, but not for prevention of
trichomoniasis. This study suggests that the presence of blood and pH affect the
activity of chlorhexidine against genital pathogens and commensals.
PMID- 10676974
TI - Determinants of low-risk and high-risk cervical human papillomavirus infections
in Montreal University students.
AB - BACKGROUND: Previous studies have been inconsistent about the degree of sexual
transmissibility of cervical human papillomavirus (HPV) infection. The authors
hypothesize that risk factors for HPV infection vary according to HPV type. GOAL:
To estimate the prevalence of HPV infection in asymptomatic women and to identify
risk factors for overall HPV infection and HPV infection by oncogenic and
nononcogenic type. STUDY DESIGN: A cross-sectional survey was conducted at the
McGill University clinic in Montreal. Cervical specimens were collected from 489
female students presenting at the clinic for a routine Papanicolaou test. Data on
potential risk factors was obtained by questionnaire. Human papillomavirus DNA
was detected by the polymerase chain reaction using consensus primers (MY09/11)
followed by hybridization with generic and type-specific probes using Southern
blot and dot blot techniques. RESULTS: The overall HPV prevalence was 21.8%. A
low-risk HPV infection was found in 6.2% of the women, 11.8% had a high-risk HPV
infection (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58), 7.1% had an unknown
HPV type, and 2.7% had a multiple type infection. Two profiles emerged for sexual
activity and risk of HPV infection according to oncogenic risk after multivariate
analysis. Lifetime frequency of sexual intercourse and lifetime number of oral
sex partners was associated with high-oncogenic-risk HPV infections; however, HPV
infection with low-oncogenic-risk types was invariant with respect to markers of
sexual activity. CONCLUSION: These results suggest that there are differences in
epidemiologic correlates of transmission between low-risk and high-oncogenic-risk
HPV types based on oncogenicity. This finding has important implications for
primary prevention of HPV infection and cervical cancer precursors.
PMID- 10676975
TI - Risk factors for HTLV-I and II in individuals attending a clinic for sexually
transmitted diseases.
AB - BACKGROUND: To date, few studies have provided information on risk factors for
human t-lymphotropic viruses (HTLV) types I and II in European countries. In
particular, few data are available from published studies conducted in STD
centers. GOALS: To identify risk factors for HTLV-I and HTLV-II infection and to
better distinguish the epidemiologic patterns of the two viruses in Italy. STUDY
DESIGN: A cross-sectional study of individuals at high risk of sexually or
parenterally transmitted infections attending a large STD center in an urban
setting was conducted. Serologic tests for HTLV-I and II, HIV, hepatitis virus
type B (HBV), hepatitis virus type C (HCV), and syphilis were performed.
Information regarding at-risk behavior was collected using a specific
questionnaire. RESULTS: From January 1994 to June 1996, 1,457 individuals were
recruited; of them, 1,016 (69.7%) were males, 1,051 (72.4%) Italians, and 288
(19.8%) non-Europeans. One thousand seventy-five (74.8%) participants were
noninjecting-drug-using heterosexuals, 285 (19.6%) were men who have sex with
men, and 97 (6.6%) were injecting drug users (IDU). The mean age of the study
participants was 33.6 (+/-10.5) years. Nine (0.6%) individuals were positive for
HTLV-I antibodies and 9 (0.6%) for HTLV-II antibodies. The prevalence of HTLV-I
among IDUs, men who have sex with men, and noninjecting-drug-using heterosexuals,
was 2.1% (2/97), 1.4% (4/ 285), and 0.3% (3/1085), respectively. HTLV-II
prevalence was 8.2% (8/97) among IDUs and 0.09% (1/1075) among noninjecting-drug
using heterosexuals. Among the nine HTLV-II-positive individuals, eight were
Italian IDUs and one was a noninjecting-drug-using heterosexual man from India.
None of the 285 men who have sex with men had HTLV-II antibodies. HTLV-infected
individuals tended to be older than those who were uninfected. HTLV-I-infected
individuals were more likely to be non-European and to have antibodies against
Treponema pallidum. Injecting drug use tended to be independently associated with
HTLV-II infection. CONCLUSIONS: The data suggest a role of sexual behavior in the
spread of HTLV-I, which is more likely to be detected in individuals coming from
endemic areas. Injecting drug use remains the most important risk factor for HTLV
II infection in Italy.
PMID- 10676976
TI - Predictors of female condom use among women exchanging street sex in New York
City.
AB - BACKGROUND: Alternative female-initiated barrier methods, such as the female
condom, are needed among women exchanging street sex to enhance their ability to
protect themselves from HIV and STD infection. OBJECTIVE: To describe predictors
of female condom use among 96 women exchanging sex for money and drugs on the
streets of New York City. STUDY DESIGN: A total of 113 sex workers received a
baseline interview, a demonstration on proper female condom use, and 10 female
condoms. A total of 101 sex workers received a followed-up evaluation at 2 weeks,
of which 96 were included in data analysis. Predictors of condom use were
analyzed for (1) any type of use; and (2) use with commercial partners. RESULTS:
The strongest predictors of female condom use among this sample of sex workers
were (1) living with someone with a drug or alcohol problem; (2) having heard of
the female condom; and (3) homelessness. Current physical or sexual abuse by a
commercial partner and marriage decreased the probability of female condom use.
CONCLUSIONS: Female condom distribution encouraged sex workers who may be most
vulnerable or who reported characteristics or behaviors associated with the
highest sexually transmitted disease and HIV risk to try female condoms with
commercial partners. Implications for intervention development include the need
to develop innovative programs provided on the street (e.g., through peers) that
can access homeless, drug-using sex workers in the most at-risk environments.
PMID- 10676977
TI - Evaluating AIDS prevention interventions using behavioral and biological outcome
measures.
AB - OBJECTIVE: To begin a dialogue on the role of behavioral and biological outcome
measures in evaluating the effectiveness of behavior change interventions to
reduce the risk of transmitting and acquiring HIV and other sexually transmitted
diseases (STDs). METHODS: A selective review of the literature was undertaken to
identify issues and problems associated with the use of behavioral and biological
outcome measures. In particular, the article considers the validity of self
reports and the theoretical relationships between behavioral and biological
measures. RESULTS: Available data suggest that when proper care is taken,
behavioral self-reports are valid. Similarly, sensitive and specific diagnostic
tests are available, particularly for bacterial STDs. However, even when
diagnostic tests and behavioral self-reports provide valid data, one should not
expect a simple relationship between behavioral and biological measures.
CONCLUSION: Both behavioral and biological measures are important outcomes for
studying the efficacy and effectiveness of behavior-change interventions.
However, one measure cannot substitute for or validate the other, and neither
serves as a true surrogate for HIV prevalence or incidence. Therefore, it is
important to better understand the relationship among STDs, HIV, and self
reported condom use. To do this, it will first be necessary to assess correct as
well as consistent condom use.
PMID- 10676978
TI - Cumulative experience with Haemophilus ducreyi 35000 in the human model of
experimental infection.
AB - BACKGROUND AND OBJECTIVES: To study Haemophilus ducreyi pathogenesis, the authors
developed an experimental model of infection in human volunteers. The authors
analyze their cumulative experience with strain 35000 in the model and calculate
the papule and pustule formation rates for estimated delivered doses (EDDs)
ranging from 1 cfu to 100 cfu. STUDY DESIGN: Sixty-five volunteers were included
in the analysis. A total of 139 sites were available for calculation of the
papule formation rate, and 117 sites were available for calculation of the
pustule formation rates. RESULTS: The effect of EDDs and probabilities of papule
formation and the pustule formation were dose-dependent. Increasing the EDD
resulted in a higher probability of papule and pustule formation. CONCLUSION: H
ducreyi is highly infectious for humans. Inoculation of an EDD of 1 cfu causes a
papule formation rate of 50%. Pustule formation rates are approximately 50% for
27 cfu and 90% for 100 cfu.
PMID- 10676979
TI - Resistance of Neisseria gonorrhoeae epidemic strains to antibiotics: report of
resistant isolates and surveillance in Zhanjiang, China: 1998 to 1999.
AB - BACKGROUND: Antibiotics are widely used to treat gonorrhea. Changes in the
susceptibility of Neisseria gonorrhoeae to these agents may influence their use.
GOAL: To measure the antibiotic susceptibility of N gonorrhoeae epidemic strains
in Zhanjiang (Guangdong) and to evaluate the prevalence of strains with reduced
susceptibility. STUDY DESIGN: A total of 98 gonococcal isolates obtained from
1998 through 1999 in Zhanjiang were tested for antibiotic susceptibility based on
the systemic identification. The inhibitory zone diameters (mm) and the MICs of
penicillin, tetracycline, spectinomycin, ceftriaxone, and ciprofloxacin were
determined using disk-diffusion and agar-dilution methods, respectively. The
susceptibilities of these isolates were defined using criteria of the National
Committee for Clinical Laboratory Standards. RESULTS: The percentages of
gonococci-resistant strains to penicillin, tetracycline, spectinomycin,
ceftriaxone, and ciprofloxacin were 32.65%, 69.39%, 8.16%, 13.27%, 82.65% by disk
diffusion method and 23.91%, 49.46 %, 11.11%, 16.48%, 59.34% by agar-dilution
method, respectively. CONCLUSIONS: The resistant strains of contemporary
gonococci in Zhanjiang were serious, especially for ciprofloxacin resistance.
Continued active surveillance is needed to detect and control the spread of
ceftriaxone-resistant and spectinomycin-resistant N gonorrhoeae.
PMID- 10676980
TI - Acceptability of formulations and application methods for vaginal microbicides
among drug-involved women: results of product trials in three cities.
AB - BACKGROUND AND OBJECTIVES: Female-controlled methods of HIV prevention, such as
vaginal microbicides, are urgently needed, particularly among drug-involved
women. Acceptability research is critical to product development. GOAL: To assess
the acceptability of forms and application methods for future microbicides.
DESIGN: Eighty-four drug-involved women were introduced in groups to three
lubricant products, asked to try each for 3 weeks, and scheduled for individual
follow-up interviews. RESULTS: Participants and their partners felt positive
about the products, and expressed willingness to use microbicides if they were
shown to be effective against HIV. Women agreed on product characteristics that
influenced their reactions (e.g. ease of insertion, degree of "messiness"), but
often disagreed on whether their reactions to these characteristics were positive
or negative. CONCLUSION: Development of acceptable and effective HIV-prevention
products depends on understanding the interaction between characteristics of the
products and the characteristics and perceptions of women. Levels of sexual risk
and acceptability factors based on drug-use patterns, race and ethnicity,
culture, age, and types and attitudes of male partners suggest that a "one size
fits all" approach will not win broad acceptance among drug-involved women.
PMID- 10676981
TI - Direct injection of physiological fluids in micellar liquid chromatography.
AB - Micellar liquid chromatography (MLC), which uses mobile phases of surfactants
above the critical micellar concentration, provides a solution to the direct
injection of physiological samples by solubilizing the protein components, and
coating the analytical column with surfactant monomers to avoid clogging. A
review showing the advantages and limitations of this technique over other
chromatographic techniques used in drug analysis, working protocols, and examples
of application is presented. The possibility of direct sample introduction
simplifies and greatly expedites the treatments with reduced cost, improving the
accuracy of the procedures. Surfactant monomers and micelles appear to displace
drugs bound to proteins, releasing them for partitioning to the stationary phase.
The versatility of MLC encompasses the wide range of drug classes normally
monitored, such as analgesics, anticancer drugs, antidepressants, bacteriostats,
beta-blockers, bronchodilators, catecholamines, diuretics and steroids, among
others. Analytical procedures have been developed in urine, plasma, serum and cow
milk samples. Most of them utilize sodium dodecyl sulphate as surfactant and a
C18 column. UV detection is usual, but enhanced detection has been reported by
measuring the absorbance in the visible region of drug derivatives formed
precolumn, and with a variety of other techniques, such as fluorimetry,
amperometry, inductively coupled plasma-mass spectrometry and immunoassay. Column
switching with on-line surfactant-mediated sample clean-up is shown as an
attractive enrichment technique, which expands the practical use of MLC beyond
the singular dimensional chromatographic process.
PMID- 10676982
TI - Quantitation of cerivastatin and its seven acid and lactone biotransformation
products in human serum by liquid chromatography-electrospray tandem mass
spectrometry.
AB - A method for the simultaneous quantitation of cerivastatin (acid) and its
biotransformation products, cerivastatin lactone, M-1 (acid), M-1 lactone, M-23
(acid), M-23 lactone, M-24 (acid) and M-24 lactone, in human serum by high
performance liquid chromatography (LC) with positive ion electrospray tandem mass
spectrometry (MS-MS) was developed and validated. The method involves extraction
of cerivastatin and its biotransformation products from acidified human serum
(0.5 ml) using methyl tert.-butyl ether. The standard curve ranges in human serum
were from 0.0100 to 10.0 ng/ml for cerivastatin and cerivastatin lactone, 0.0500
to 10.0 ng/ml for M-1 (acid) and M-1 lactone, 0.100 to 10.0 ng/ml for M-23 (acid)
and M-23 lactone, and 0.500 to 10.0 ng/ml for M-24 (acid) and M-24 lactone. The
lactone compounds in human serum at room temperature underwent considerable
conversion to the corresponding acid compounds after only 4 h. Lowering the serum
pH with a pH 5.0 buffer stabilized the lactone compounds for up to 24 h at room
temperature. The degree of lactonization of the acid compounds was < or = 3.5%
and the degree of hydrolysis of the lactone compounds was < or = 6.0% during the
entire assay procedure. All the eight analytes eluted within 2.0 min and the
total run time was only 3.5 min.
PMID- 10676983
TI - Analysis of melphalan adducts of 2'-deoxynucleotides in calf thymus DNA
hydrolysates by capillary high-performance liquid chromatography-electrospray
tandem mass spectrometry.
AB - Melphalan is a bifunctional alkylating agent that covalently binds with
intracellular nucleophilic sites. A methodology using electrospray mass
spectrometry was developed to detect and identify DNA adducts. Alkylation sites
within a particular nucleotide were examined using electrospray tandem mass
spectrometry hyphenated to capillary liquid chromatography in combination with a
column switching system. In the reaction mixtures resulting from the interaction
of 2'-deoxynucleotides and melphalan several base-aklylated adducts were found.
In the case of 2'-deoxyadenosine monophosphate, thymidine monophosphate and 2'
deoxyguanosine phosphate alkylation was observed in the mononucleotide reaction
mixtures but not in the DNA-hydrolysates. Calf thymus DNA was reacted in vitro
with melphalan. The DNA pellet was isolated and enzymatically hydrolyzed with the
aid of Nuclease P1. In this hydrolysate both mono-alkylated 2'-deoxynucleotides
and dinucleotides were found. The most important adduct found was identified as
the N-7 alklylated dGMP adduct. The alkylated dinucleotides were identified as a
pdApdT/melphalan and pdGpdC/melphalan the latter being the most important.
PMID- 10676984
TI - High-performance liquid chromatographic determination of [11C]1-(2-chlorophenyl)
N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide in mouse plasma and tissue
and in human plasma.
AB - The high-performance liquid chromatographic determination of 1-(2-chlorophenyl)-N
methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide ([11C]PK 11195) is
described. The method was successfully applied for plasma and tissue analysis
after i.v. injection of [11C]PK 11195 in mice and for plasma analysis after
administration of [11C]PK 11195 to humans. Separation is effected on a RP-C18
column, using a mixture of acetonitrile-water-triethylamine (65:35:0.5, v/v).
Quantitative measurements of radioactivity are performed on a one-channel gamma
ray spectrometer equipped with a 2 x 2 in. NaI(Tl) detector. For humans rapid
metabolisation of [11C]PK 11195 was observed. At 5, 20 and 35 min post injection
5%, 22% and 32%, respectively, of the plasma activity consisted of at least two
more polar metabolites. Despite the extensive metabolisation rate in mice (up to
42% at 10 min post injection of [11C]PK 11195), no 11C-labelled metabolites could
be detected in the extracts of brain and heart.
PMID- 10676985
TI - Quantitative determination of a potent lipopolysaccharide antagonist, E5564, in
rat and dog plasma by high-performance liquid chromatography with fluorescence
detection.
AB - The assay method was established for the quantification of a potent
lipopolysaccharide (LPS) antagonist, E5564, in rat and dog plasma using HPLC.
E5564 and the I.S. (an analogue of E5564) were extracted and derivatized with 9
Anthryldiazomethane (ADAM reagent) to be given fluorescence. LC-MS analysis
indicated that single molecule of E5564 was coupled with two molecules of ADAM
reagent at one on each of the phosphorus groups. After solid-phase extraction,
ADAM derivatives of E5564 and the I.S. were separated on an ODS column using
methanol/ethanol containing sodium acetate as a mobile phase at 1.2 ml/min
(gradient elution), and detected by a fluorescence detector (excitation: 254 nm,
emission: 415 nm). The intra-day and inter-day precision were less than 14.4%,
and accuracy were within +/-13.0% in the concentration range of 30 to 20,000
ng/ml plasma in both species. E5564 was stable for at least 13 days in rat and
dog plasma at -20 degrees C, and the processed sample was stable for up to 14
days at 4 degrees C. This validated method was successfully applied to the
evaluation of the pharmacokinetics of E5564 in rats and dogs after single bolus
intravenous doses.
PMID- 10676986
TI - Separation of human vitamin K-dependent coagulation proteins using hydrophobic
interaction chromatography.
AB - A rapid and simple method was developed to separate human vitamin K-dependent
plasma proteins from each other, yielding virtually homogeneous pools. The
purification technique is based on the single use of hydrophobic interaction
chromatography, starting from prothrombin concentrate (PC or DEFIX, also termed
factor IX concentrate) as initial material. Phenyl-sepharose HP demonstrated
optimal separation by comparing several hydrophobic resins as well as resins used
in standard procedures like immobilised heparin and Cibacron blue. Under ideal
conditions, factor X could be separated in a single step as well as prothrombin.
Factor IX co-eluted with other minor proteins. Focus was given only on these
three proteins due to their relative abundance. Complete separation of all
proteins present in the starting material was achieved by MonoQ anion-exchange
chromatography following the phenyl-sepharose run. The resulting purified
material could be demonstrated to be of equal or higher purity than using
described methods. This strategy employing hydrophobic interaction chromatography
for blood macromolecules could be of immense value for purifying the human
vitamin K-dependent proteins and represents a considerable simplification over
other purification schemes. It not only involves minimal sample handling but also
can be readily up-scaled and is a cost-efficient alternative.
PMID- 10676987
TI - Determination of tramadol by capillary gas chromatography with flame ionization
detection. Application to human and rabbit pharmacokinetic studies.
AB - A rapid, sensitive, precise and accurate capillary gas chromatographic assay with
flame ionization detection was developed for the determination of tramadol in
human, rabbit, pig and dog plasma. It is comprised of only a one-step extraction
procedure with dichloromethane at pH 11.15 and gas chromatography on a capillary
column. The recoveries of tramadol and meperidine (internal standard) were
greater than 88%. Calibration graphs were linear over the concentration range
12.5-10,000 ng/ml with a coefficient of variation, both within-day and between
day, of less than 10% at any level. The limit of detection was 8 ng/ml of plasma
based on signal-to-noise ratio of 3. Six other clinically used analgesics were
investigated to check for potential interferences and their analytical
conditions. The specificity of this assay was checked with two major metabolites
of tramadol (M1: O-demethyltramadol; M2: N-demethyltramadol). Tramadol in plasma
did not decompose significantly at -20 degrees C for 56 days. Pharmacokinetic
application with intravenous tramadol in humans and rabbits revealed that
tramadol followed a two-compartment open model with one distribution phase and
one elimination phase. The distribution and elimination half-lives in humans were
1.02 and 141.9 min. The distribution and elimination half-lives in rabbits were
7.31 and 63.2 min, respectively.
PMID- 10676988
TI - Simple and sensitive determination of 5-fluorouracil in plasma by high
performance liquid chromatography. Application to clinical pharmacokinetic
studies.
AB - 5-Fluorouracil (5-FU) is an antineoplastic agent widely employed in the treatment
of many types of cancer. Recent studies have proved the need for individual
adjustment of 5-FU dosage based on pharmacokinetics. A simple and sensitive high
performance liquid chromatographic method for the determination of 5-FU in plasma
and their preliminary clinical pharmacokinetics is described. After sample
acidification with 20 microl of orthophosphoric acid (5%), the drug is extracted
from plasma using n-propanol-diethyl ether (16:84). The organic layer is
evaporated to dryness, the residue dissolved in 100 microl of mobile phase and 20
microl of this mixture is injected into a LiChrospher 100RP-18 (5 microm, 250 x
4.0 mm) analytical column. Mobile phase consisted of potassium
dihydrogenphosphate (0.05 M, adjusted to pH 3). The limit of quantitation was 2
ng/ml. The method showed good precision: the within-day relative standard
deviation (RSD) for 5-FU (10-20,000 ng/ml) was 3.75% (2.57-5.93); the between-day
RSD for 5-FU, in the previously described range, was 5.74% (4.35-7.20). The
method presented here is accurate, precise and sensitive and it has been
successfully applied for 5-FU pharmacokinetic investigation and therapeutic drug
monitoring.
PMID- 10676989
TI - Validation of urine drug-of-abuse testing methods for ketobemidone using thin
layer chromatography and liquid chromatography-electrospray mass spectrometry.
AB - High-performance thin-layer chromatography (TLC) with visual detection (post
chromatographic derivatization) was used in screening for the drug ketobemidone
in human urine samples. High-performance liquid chromatography with electrospray
mass spectrometry (LC-ESI-MS) was used for final confirmation of the result. The
clean-up was performed by mixed-mode solid-phase extraction, and nalorphine was
used as internal standard. A screening cut-off for TLC was established at 0.2
microg/ml. The mean recovery for LC-MS was 91% (n=60) with coefficients of
variation (C.V.) in the range of 7 to 16%. Qualifying fragment ions of
ketobemidone (m/z 190, 201 and 230) were generated by up front collision-induced
dissociation (CID) on a single quadrupole instrument. Relative ion intensities
were within +/- 15% deviation compared with standards in the same batch. The
limit of detection for LC-MS was 0.025 microg/ml. Positive clinical samples from
drug abusers (n=10) had concentrations in the range 0.07 to 3.2 microg/ml, which
could be determined by LC-MS without matrix interference. During screening of
unknown clinical samples (n=27) the results from TLC was in agreement with LC-MS
data. After acid hydrolysis of conjugates in clinical samples the analyte
response of ketobemidone and norketobemidone was increased by a factor of
approximately two and twelve, respectively. A qualitative GC-MS technique was
demonstrated for the detection of the spasmolyticum A29 (N,N-dimethyl-4,4
diphenyl-3-buten-2-amine), which can be found in a preparation combined with
ketobemidone (Ketogan).
PMID- 10676990
TI - Improved and simplified liquid chromatographic assay for adefovir, a novel
antiviral drug, in human plasma using derivatization with chloroacetaldehyde.
AB - A rapid and simplified chromatographic assay is reported for the quantification
of adefovir (PMEA) utilizing derivatization with chloroacetaldehyde. Adefovir is
isolated from plasma using protein precipitation with trichloroacetic acid; next,
the fluorescent 1,N6-etheno derivative is directly formed at 98 degrees C in the
buffered extract with chloroacetaldehyde. This derivative is analyzed using
isocratic ion-pair liquid chromatography and fluorescence detection at 254 nm for
excitation and 425 nm for emission. In the evaluated concentration range (10-1000
ng/ml) precisions < or = 5% and accuracies between 95 and 117% were found, using
a 0.2-ml volume of plasma. The lower limit of quantification is 10 ng/ml with a
intra-assay precision of 16%. The currently reported bioanalytical method is 20
25-fold more sensitive than previously published assays.
PMID- 10676991
TI - Quantitative determination of abacavir (1592U89), a novel nucleoside reverse
transcriptase inhibitor, in human plasma using isocratic reversed-phase high
performance liquid chromatography with ultraviolet detection.
AB - Abacavir is a novel nucleoside reverse transcriptase inhibitor for the treatment
of HIV-1 infection. A simple and rapid high-performance liquid chromatographic
method for the quantification of abacavir in human plasma suitable for
pharmacokinetic research purposes is described. Sample pretreatment consists of
protein precipitation with perchloric acid. The supernatant is injected directly
into the chromatographic system after centrifugation. The drug is separated from
endogenous compounds by isocratic reversed-phase high-performance liquid
chromatography with ultraviolet detection at 285 nm. The method has been
validated over the range of 20-2000 ng/ml using a volume of 300 microl of plasma.
The assay is linear over this concentration range as indicated by the F-test for
lack-of-fit. Within- and between-day precisions are less than 7.5% for all
quality control samples. The lower limit of quantitation is 20 ng/ml and the
recovery of abacavir is 88.1% (+/-1.3%). Frequently coadministered drugs did not
interfere with the described methodology. Abacavir is stable in human plasma
under various relevant storage conditions, for example when stored for 51 days at
-20 degrees C. This validated assay is suited for use in pharmacokinetic studies
with abacavir in human plasma and can readily be implemented in the setting of a
hospital laboratory for the monitoring of abacavir concentrations.
PMID- 10676992
TI - Determination of unbound cefmetazole in rat blood by on-line microdialysis and
microbore liquid chromatography: a pharmacokinetic study.
AB - A specific and sensitive microbore liquid chromatographic method for the
determination of unbound cefmetazole in rat blood was developed. A microdialysis
probe was inserted into the jugular vein/right atrium of a Sprague-Dawley rat.
Cefmetazole (10 mg/kg, i.v.) was then administered via the femoral vein.
Dialysates were automatically injected into a liquid chromatographic system via
an on-line injector. Isocratic elution of cefmetazole was achieved by LC-UV
within 10 min. Intra- and inter-assay accuracy and precision of the assay were <
or = 10%. The detection limit of cefmetazole was 20 ng/ml. Pharmacokinetic
analysis of results indicated that unbound cefmetazole levels in rats best fit a
biexponential decay model.
PMID- 10676993
TI - High-performance liquid chromatographic assay for the determination of the novel
taxane derivative IDN5109 in mouse plasma.
AB - An HPLC assay was developed to determine the paclitaxel analogue 13-(N-tert.
butoxycarbonyl-beta-isobutylisoserinyl)-14-hydroxyb accatin-1,14-carbonate
(IDN5109) and its epimer in mouse plasma. The method involves solid-phase
extraction on cyano cartridges (recovery >75%), HPLC separation on symmetry
shield column, a mobile phase of NaH2PO4 (10 mM) pH 5.2, acetonitrile (47:53) and
detection at 227 nm. Retention times of IDN5109, its epiform and internal
standard were 15, 24 and 25.5 min, respectively. The assay was linear from 0.10
to 10 microg/ml (r2 = 0.999), with a C.V. <5% and accuracy in the range of 95
107%. LOQ was 50 ng/ml for both compounds. Using this method IDN5109
pharmacokinetic was determined in mice.
PMID- 10676994
TI - Radiochemical high-performance liquid chromatographic assay for the determination
of catechol O-methyltransferase activity towards various substrates.
AB - A new chromatographic catechol O-methyltransferase (COMT) assay based on S
adenosyl-L-[methyl-14C]methionine and on-line radioactivity detection was
developed. With minor modifications in the mobile phase composition the
methylation velocities for 30 structurally diverse compounds including simple
catechols, neurotransmitters, catecholestrogens and catecholic drugs could be
measured using human and rat recombinant soluble COMT. The enzymes showed very
similar substrate selectivities. The radiochemical method was validated using 3,4
dihydroxybenzoic acid as a model substrate and it was shown that accurate and
reproducible methylation velocity values could be achieved for both of the
catecholic hydroxyls. The method proved to be suited for determining the enzyme
kinetic parameters and can probably be further used for gathering enzyme kinetic
data on differentially substituted catechols in order to construct proper
structure-activity relationships for COMT.
PMID- 10676995
TI - Aggregation of recombinant hepatitis B surface antigen induced in vitro by
oxidative stress.
AB - In order to examine whether oxygen radicals could be responsible for aggregation
of recombinant hepatitis B surface antigen (HBsAg) during its assembly in yeast,
purified HBsAg was oxidized with ammonium peroxodisulphate (AP) and analyzed by
non-denaturing and denaturing size exclusion chromatography, immunoassay and
immunoelectron microscopy. As a result, peroxodisulphate radicals induced a
reproducible aggregation of HBsAg. At 44 mM AP, the aggregation process took a
few hours and the resulting structures were large, branched and non-antigenic.
During more gentle oxidation with 9 mM AP and 20-80 microM Cu2+, a continuous
structural modification to HBsAg delaying for tens of hours preceded the
aggregation event. During this pre-aggregation period, peroxidation of HBsAg
lipids and covalent cross-linking of S protein chains occurred that led a
complete loss of antigenicity of oxidized particles. In contrast, yeast-derived
HBsAg aggregate is decomposed to S monomers under reducing conditions and
recognized by anti-HBsAg polyclonal and monoclonal antibodies, suggesting that is
has been assembled in vivo from antigenic and reversibly cross-linked particles.
Based on these observations, we conclude that oxidation, at least with respect to
the specific molecular sites oxidized by AP, is not a primary event in HBsAg
aggregate formation in vivo. Since oxidized HBsAg was shown to be irreversibly
cross-linked and non-antigenic, there are no suitable techniques for detection
HBsAg oxidation in biological samples. Hence, at present, the magnitude of the in
vivo oxidative damage to HBsAg cannot be evaluated and thus, whether the plasma
derived HBsAg undergoes radical-induced oxidation in the course of viral
hepatitis remains to be established. If this occurs, this process is expected to
contribute to low HBsAg levels in chronic hepatitis B carriers, failure of the
currently available immunoassays to identify HBsAg-positive blood donors and
inconsistency in the results provided by HBsAg- and anti-HBsAg-based tests in
several recent reports.
PMID- 10676996
TI - Determination of flunarizine in rat brain by liquid chromatography-electrospray
mass spectrometry.
AB - A rapid liquid chromatography-electrospray mass spectrometry (LC-ES-MS) assay for
the determination of flunarizine (FZ) in rat brain has been developed. A C18
column and an isocratic elution were employed for the separation. Using post
column split, 64% of the eluent was introduced into the ES-MS system for
detection. The [M+H]+ (m/z 406) and a fragmented ion (m/z 203) were detected
using selected ion monitoring. The linear range of this assay was good, ranging
from 0.05 to 5 microM (r2=0.99). The intra- and inter-day precisions showed
relative standard deviations ranging from 1.4% to 2.0% and 1.3% to 2.9%,
respectively. The application of this newly developed method was demonstrated by
examining the pharmacokinetics of FZ in rat brain.
PMID- 10676997
TI - Sensitive determination of irinotecan (CPT-11) and its active metabolite SN-38 in
human serum using liquid chromatography-electrospray mass spectrometry.
AB - A couple of sensitive and accurate liquid chromatography-electrospray mass
spectrometry (LC- S-MS) methods for the determination of the total forms of
irinotecan and its active metabolite SN-38 in human serum, using the same
chromatographic and detection conditions, is presented. Both used camptothecin as
internal standard (I.S.). The sample pretreatment for irinotecan involved a
simple protein precipitation with acetonitrile, whereas a liquid-liquid
extraction was necessary for SN-38. A Symmetry C18, 3.5 microm (150 x 1 mm I.D.)
reversed-phase column was used for the chromatographic separation, together with
a gradient elution of acetonitrile in 5 mM ammonium formate buffer (pH 3) as
mobile phase. After ionisation in the pneumatically-assisted electrospray source
and in-source collision induced dissociation, acquisition was performed in the
selected ion monitoring mode. Recoveries were 69 and 47% on average, detection
limits 2.5 and 0.25 ng/ml and quantitation limits 10 and 0.5 ng/ml for irinotecan
and SN-38, respectively. Reproducibility was good and the method was linear from
limits of quantitation up to 10,000 ng/ml for irinotecan, and up to 100 ng/ml for
SN-38. This sensitive and highly specific method is suitable both for
pharmacokinetic studies and routine therapeutic drug monitoring.
PMID- 10676998
TI - Identification of metallothionein isoforms on capillary zone electrophoresis by
adding anti-metallothionein antibody.
AB - The aim of this study was to identify metallothionein (MT) isoforms in mouse
liver by using capillary zone electrophoresis (CZE). Purified MT-1 and MT-2
isoforms were completely separated by CZE using a polyacrylamide-coated tube at
physiologic pH. There were two peaks in the cytosol fraction prepared from zinc
injected mouse liver, in which the migration times corresponded with those of
purified MT-1 and MT-2 isoforms. When anti-MT monoclonal antibody was added with
the purified MT-1 or MT-2 solution, the peaks decreased. Furthermore, the two
peaks in the cytosol prepared from Zn-injected mouse liver decreased in a time
dependent manner from the electropherogram after the addition of the antibody.
Therefore, those peaks were identified as MT-1 and MT-2 isoforms, respectively.
In conclusion, the addition of anti-MT monoclonal antibody to the cytosol
fraction of tissues is an effective method for identification of MT isoforms
after separation using CZE.
PMID- 10676999
TI - Highly sensitive high-performance liquid chromatographic assay for methotrexate
in the presence and absence of anti-methotrexate antibody fragments in rat and
mouse plasma.
AB - Recently, Balthasar and Fung have proposed that anti-methotrexate antibody
fragments may be employed to enhance the selectivity of intraperitoneal
methotrexate (MTX) therapy. This current work presents a sensitive high
performance liquid chromatographic method for measuring plasma concentrations of
total (i.e., bound and unbound) MTX and free (unbound) MTX in rat and mouse
plasma, in the presence or absence of therapeutic anti-MTX antibody fragments.
The assay involves pre-column derivatization of MTX by sodium hydrosulfite to 2,4
diamino-6-methylpteridine. The limit of quantitation for MTX by this assay was
1.25 ng in rat plasma, mouse plasma and mouse plasma ultrafiltrate, which
corresponds to a concentration of 25 ng/ml for a 50 microl sample. The limit of
quantitation was found to be 2.5 ng in rat plasma ultrafiltrate (i.e., 50 ng/ml
in 50 microl rat plasma ultrafiltrate). The method was shown to be quite
accurate, as the mean assayed concentration of quality control samples was within
10% of theoretical values. We have applied the method to the investigation of MTX
pharmacokinetics in mice and rats, following the administration of MTX alone or
following simultaneous administration of MTX and anti-MTX Fab fragments. The
method has been shown to be suitable for the assay of total and free methotrexate
in the plasma of these species and will enable the testing of pharmacokinetic
hypotheses regarding the influence of anti-MTX Fab fragments on the disposition
of MTX.
PMID- 10677000
TI - Stereoselective measurement of E- and Z-doxepin and its N-desmethyl and
hydroxylated metabolites by gas chromatography-mass spectrometry.
AB - A stereoselective method of analysis of the antidepressant drug doxepin (DOX, an
85:15% mixture of E-Z stereoisomers), its principal metabolites E- and Z-N
desmethyldoxepin (desDOX) and ring-hydroxylated metabolites in microsomal
incubation mixtures is described. DOX and its metabolites were extracted from
alkalinised incubation mixtures by either: 9:1 hexane-propan-2-ol (method 1) or
1:1 hexane-dichloromethane (method 2), derivatised with trifluoroacetic anhydride
and analysed by GC-MS with selected ion monitoring. Both methods were suitable
for the analysis of individual desDOX isomers as indicated by correlation
coefficients of > or = 0.999 for calibration curves constructed between 50 and
2500 nM, and good within-day precision at 125 nM (C.V. < or = 14%) and 1000 nM
(C.V. < or = 8%). Method 1, however, was unsuitable for the analysis of ring
hydroxylated metabolites of DOX, whereas the hydroxylated metabolites of E-DOX
and E-desDOX (generated in situ) were extracted by method 2 with a C.V. of ca.
13%. This is the first assay method that permits the simultaneous measurement of
desDOX and hydroxylated metabolites of DOX in microsomal mixtures.
PMID- 10677001
TI - Quantitative analysis of clenbuterol in meat products using liquid chromatography
electrospray ionisation tandem mass spectrometry.
AB - A method is presented that allows quantitation of clenbuterol in meat and liver
products at the ng/kg level by liquid chromatography-electrospray ionisation
tandem mass spectrometry (LC-ESIMS-MS) using a stable isotopically labeled
internal standard. The practical procedure involves acid extraction followed by
two solid-phase clean-up steps with C18 and strong cation-exchange (SCX) resins.
The typical recovery of the analyte spiked at 0.4 microg/kg in meat and liver
samples was at 63+/-7%. Mass spectral acquisition was done in multiple reaction
monitoring (MRM) to provide a high degree of sensitivity, achieving a limit of
detection and quantitation at 10 and 15 ng/kg, respectively. Two precursor ions
at m/z 277 and 279, corresponding to the characteristic isotopic cluster of the
two chlorine atoms of clenbuterol, were monitored by LC-ESIMS-MS to provide
unambiguous identity of the analyte. Samples of meat and liver of various origins
with either incurred residues or spiked with known amounts of clenbuterol were
used to validate the method.
PMID- 10677002
TI - High-performance thin-layer chromatography method for inositol phosphate
analysis.
AB - A simple and inexpensive high-performance thin-layer chromatography (HPTLC)
method for the analysis of inositol mono- to hexakisphosphates on cellulose
precoated plates is described. Plates were developed in 1-propanol-25% ammonia
solution-water (5:4:1) and substance quantities as low as 100-200 pmol were
detected by molybdate staining. Chromatographic mobilities of nucleotides and
phosphorylated carbohydrates were also characterized. Charcoal treatment was
employed to separate nucleotides from inositol phosphates with similar R(F)
values prior to HPTLC analysis. Practical application of the HPTLC system is
demonstrated by analysis of grain extracts from wild type and low-phytate mutant
barley as well as phytate degradation products resulting from barley phytase
activity.
PMID- 10677003
TI - Determination of cetirizine in human plasma by high-performance liquid
chromatography.
AB - A high-performance liquid chromatographic method for the quantitation of
cetirizine in human plasma is presented. The method is based on liquid-liquid
extraction with dichloromethane and reversed-phase chromatography with
spectrophotometric detection at 232 nm. Gradient elution was used to remove late
eluting peaks. Diazepam was used as the internal standard. The limit of
quantitation was 10 ng/ml using 0.5 ml of plasma. Within-day and between-day
precision expressed by relative standard deviation was less than 10% and
inaccuracy did not exceed 8%. The assay was applied to the analysis of samples
from a pharmacokinetic study.
PMID- 10677004
TI - 3-Hydroxyanthranilic acid-derived compounds formed through electrochemical
oxidation.
AB - 3-Hydroxyanthranilic acid (3-HAA)-derived oxidation products were analyzed using
high-performance liquid chromatography with an electrochemical reactor and diode
array detection and high-performance liquid chromatography with an
electrochemical reactor and UV detection coupled with mass spectrometry. In
addition to 3-HAA dimers such as cinnabarinic acid (CA), 6-amino-3-[(2-carboxy-6
hydroxyphenyl)amino]-2,5-dioxo-1,3-cyclohexadien e-1-carboxylic acid and 4,7
diamino-8-hydroxy-6H-dibenzo[a,d]pyran-6-one-3-carboxylic acid, a 3-HAA trimer
and a 3-HAA tetramer were also detected and identified based on their
electrospray ionization mass spectra and their UV-visible spectra. These five
oxidation products were also detected on the elution profiles of high-performance
liquid chromatography-diode array detection analyses for the reaction mixtures of
the auto-oxidation of 3-HAA, of 3-HAA with potassium ferricyanide, of 3-HAA with
horseradish peroxidase and hydrogen peroxide, and of 3-HAA with superoxide
dismutase (SOD). 4,7-Diamino-8-hydroxy-6H-dibenzo[a,d]pyran-6-one-3-carboxylic
acid was predominant in the auto-oxidation, in the reaction of 3-HAA with
horseradish peroxidase and hydrogen peroxide, and in the electrochemical
oxidation of 3-HAA at an applied potential of 0.0 V. On the other hand, CA, the 3
HAA trimer and the 3-HAA tetramer were predominant in the reaction of 3-HAA with
K3[Fe(CN)6] and in the electrochemical oxidation of 3-HAA at an applied potential
of 1.0 V.
PMID- 10677005
TI - Capillary solid-phase extraction-tandem mass spectrometry for fast quantification
of free concentrations of tolterodine and two metabolites in ultrafiltered plasma
samples.
AB - A capillary solid-phase extraction (SPE) system has been coupled directly to
electrospray tandem mass spectrometry for quantification of free tolterodine and
metabolite concentrations in plasma. The unbound fraction of these compounds was
obtained by ultrafiltration of plasma. The ultrafiltrate was directly injected
onto the SPE capillary (4 mm x 200 microm, 5 microm C18). After desalting and
clean-up of the sample, the analytes were eluted in backflush mode with methanol
1 mM triethylamine (70:30, v/v), providing considerable solute focusing. Elution
from the SPE capillary was improved by inserting a short trapping capillary
between the SPE capillary and the MS interface, by which analyte focusing was
increased. The unresolved compounds eluted simultaneously with the remaining
matrix compounds and were detected in a multiple-reaction monitoring (MRM) mode.
No interference of the sample matrix on detection was observed, allowing aqueous
standards to be used for calibration. Linear calibration curves were obtained
between 0.05 and 1000 ng/ml (corresponding to 150 pM-3 microM) and the limit of
detection was 50 pg/ml injecting 10 microl. Equilibration of the SPE capillary,
sample loading, elution and detection took less then 6 min per sample.
PMID- 10677006
TI - Sensitive method for the determination of bisphenol-A in serum using two systems
of high-performance liquid chromatography.
AB - The aim of this study was to establish an easy and accurate method for the
determination of bisphenol-A (BPA) in the body liquid such as serum and urine.
Two high-performance liquid chromatography (HPLC) systems, HPLC with
electrochemical detector (ED), and HPLC with mass spectrometry (MS) using
electrospray ionization (ESI) interface were used for the assay in the serum
samples prepared with solid-phase extraction method. Water or EtOH at a
concentration below 50% was suitable for the extraction of BPA from serum. The
limit of detection of BPA was 0.2 ng ml(-1) for the HPLC-ED method and 0.1 ng ml(
1) for HPLC-MS. There was a good correlation between the data obtained by the two
HPLC systems. BPA concentrations in healthy human serum were low (0-1.6 ng ml(
1)). From various commercial fetal bovine serum and sheep plasma, however,
significant amounts of BPA were detected. Since no BPA was detected from sheep
plasma immediately after collection, the high amounts of BPA were considered to
be caused by the handling of blood during the preparation of the products after
blood collection. In vitro study showed that the amount of BPA leached from
polycarbonate tube into sheep plasma were 40 times larger than those into water
and the leached amount of BPA depended on the temperature (37 degrees C>20
degrees C>5 degrees C).
PMID- 10677007
TI - Direct detection of endogenous histamine in rat peritoneal mast cells by in
capillary derivatization high-performance capillary electrophoresis.
AB - A simple method for the detection of endogenous histamine in rat peritoneal mast
cells was evaluated using on-line mode in-capillary derivatization high
performance capillary electrophoretic (ICD-HPCE) techniques, which were
previously developed by our group [S. Oguri et al., J. Chromatogr. A, 787 (1997)
253-260]. The method involves a suspension of peritoneal mast cells (1 x 10(6)
cells/ml of saline) collected from a male Wistar rat (eight weeks of age), which
are directly introduced into the capillary tube from the anodic end by
hydrostatic injection (at 25 cm height, for 2-20 s). When a high-voltage
potential (25 kV) is applied to the capillary, which is already filled with the
run buffer containing both a lysing reagent (SDS, sodium dodecyl sulfate,) and a
derivatizing reagent (OPA, o-phthalaldehyde; NAC, N-acetylcysteine), histamine in
the mast cells was detected at high-sensitivity level without further procedures.
During ICD-HPCE, the mast cells injected in the capillary were lysed with the
lysing reagent, free histamine released from the cell was labeled with the
derivatizing reagent, and its derivative was electromigrated, separated and
detected with a fluorescence detector (excitation wavelength at 340 nm, emission
wavelength at 450 nm) in a fused-silica capillary (75 cm x effective length x 50
microm I.D.). The run buffer used was a 20 mM phosphate-borate buffer (pH 10)
containing 20 mM SDS, 2 mM OPA and 2 mM NAC. This method was also examined with
regard to the possibility of its use for determination of histamine at the single
mast cell level.
PMID- 10677008
TI - Characterization of a solid-phase extraction device for discontinuous on-line
preconcentration in capillary electrophoresis-based peptide mapping.
AB - Peptide mapping by capillary electrophoresis (CE) with UV detection is
problematic for the characterization of proteins that can only be obtained at low
micromolar concentrations. Dilution of peptide fragments during digestion of the
protein can further reduce the detection sensitivity in peptide mapping to the
point where analysis at sub-micromolar concentrations is not possible. A remedy
to this problem is preconcentration (sample enrichment) of the proteolytic digest
by solid-phase extraction (SPE). To minimize non-specific adsorptive losses
during sample handling, on-line SPE-CE is preferred. However, packed-inlet SPE-CE
is not always feasible due to either instrument or sample limitations. We
describe here a simple method of preconcentration by discontinuous on-line SPE
CE, specifically applied to peptide mapping in low-pH separation buffer after
protein digestion in a solid-phase enzyme microreactor. The SPE-CE system does
not require application of a low pressure during electrophoretic separation to
overcome reversed electroosmotic flow because the preconcentrator device is
disconnected from the separation capillary before the electric field is applied.
Up to a 500-fold preconcentration factor can be achieved with this device, which
can be reused for many samples. Parameters such as the volume of desorption
solution, the adsorption/desorption (chromatographic) process, reproducibility of
packing the SPE preconcentrator and effects of sample concentration on the
peptide map are investigated.
PMID- 10677009
TI - High-performance thin-layer chromatographic determination of theophylline in
plasma.
AB - A high-performance thin-layer chromatographic method for quantification of
theophylline from plasma is described. The calibration curves of theophylline in
methanol and in plasma were linear in the range 20-100 ng. The correlation
coefficients were 0.9971+/-0.0011 and 0.9955+/-0.0003 for standard curves in
methanol and in plasma, respectively. The limit of quantitation of theophylline
in human plasma (assay sensitivity) was 20 ng and no interference from endogenous
compounds was observed. The recovery of theophylline from human plasma using the
described assay procedure was 89%. The mean relative standard deviations for
intra- and inter-day analyses were 1.67% and 2.34% for 50 ng and 2.25% and 3.14%
for 75 ng theophylline concentration, respectively. The method was utilized to
monitor plasma concentration of theophylline post-administration of sustained
release tablets in human patient volunteers.
PMID- 10677010
TI - Determination of lamotrigine in human serum by liquid chromatography.
AB - A rapid high-performance liquid chromatographic method was developed using a
short silica column (30 mm x 4.6 mm) with an aqueous methanol mobile phase
consisting of methanol-water-NH4H2PO4 (94:5.96:0.04) adjusted to a final apparent
pH of 5.0 and pumped at a flow-rate of 1 ml/min. Ultraviolet detection was
carried out at a wavelength of 280 nm, and serum samples were prepared for HPLC
analysis by extraction into dichloromethane after basification. Lamotrigine was
eluted at 0.96 min. Within-day variation of the method was 4.46% at 0.75
microg/ml and 2.37% at 6.0 microg/ml, and day-to-day variation was 9.10% at 0.75
microg/ml and 7.28% at 6.0 microg/ml.
PMID- 10677011
TI - Simple and efficient method for the detection of diethylenetriaminepentaacetic
acid.
AB - Diethylenetriaminepentaacetic acid (DTPA) is a commonly used chelating agent. Its
antiviral, antibacterial and immunomodulatory effects are well documented. DTPA
forms a highly stable complex with lead (II) with an increased absorption
coefficient and a bathochromic shift of the absorption maximum compared to pure
DTPA. Based on this complex a high-performance liquid chromatographic method for
the quantitative detection of DTPA in biological fluids was developed. A
calibration curve was prepared and linearity was shown in the concentration range
between 10 mg l(-1) and 1000 mg l(-1) DTPA. The recovery in water and in human
plasma showed the method to be suitable for routine use.
PMID- 10677012
TI - Temporal and spatial expression of the period gene in the reproductive system of
the codling moth.
AB - The authors examined patterns of spatial and temporal expression of Drosophila
per gene homologue in the codling moth, Cydia pomonella. Since sperm release in
moths is regulated in a circadian manner by an autonomous clock that is
independent from the brain, the authors investigated per expression in male
reproductive system along with its expression in moth heads. per mRNA is
rhythmically expressed with the same phase and amplitude in both tissues under
light-dark (LD) conditions. The levels of per mRNA are low during the day, start
to increase before lights-off, reach the peak in dark, and decrease after lights
on. In constant darkness (DD), cycling of per mRNA continued in heads with
severely blunted amplitude. No cycling of per mRNA was detected in testis in DD.
In situ hybridization and immunocytochemistry revealed distinct spatial patterns
of per expression in the moth reproductive system. There is no expression of per
in cells forming the wall of testes or in sperm bundles. However, per mRNA and
protein are rhythmically expressed in the epithelial cells forming the wall of
the upper vas deferens (UVD) and in the cells of the terminal epithelium, which
are involved in the circadian gating of sperm release. Increase in per mRNA in
the UVD coincides with sperm accumulation in this part of the insect reproductive
system.
PMID- 10677013
TI - Involvement of the period gene in developmental time-memory: effect of the
perShort mutation on phase shifts induced by light pulses delivered to Drosophila
larvae.
AB - Phases of circadian locomotor activity rhythms of adult Drosophila reared in
constant darkness have been shown to be set by a light stimulus delivered as
early as the first-instar larval stage. This implies that a circadian clock
functions continuously throughout postembryonic development. The clock genes
period (per) and timeless (tim) are expressed cyclically in the larval central
nervous system of Drosophila, and daily oscillations of per expression persist
throughout metamorphosis in a group of cells, which gives rise to the pacemaker
cells underlying locomotor activity rhythms of adults. Therefore, PER and TIM
cyclings in these neurons may be responsible for the phenomenon of "larval time
memory." In the absence of any evidence for the involvement of these genes in
such a developmental clock, and because circadian-pacemaker functions are
underanalyzed in terms of the functions during development, the authors tested
the time-memory of a fast-clock period mutant. They show that dark-reared perS
mutant individuals as well as wild-type flies can be entrained as larvae and that
a brief light pulse given to such entrained larvae can induce phase shifts in
animals of either genotype. However, the direction and magnitude of phase shifts
were different between wild type and perS, suggesting that a clock under the
control of period gene participates in the regulation of developmental time
memory. The authors show that the relevant clock can be entrained by two light
input pathways, one involving the phospholipase C encoded by the norpA gene, the
other mediated by the blue-light receptor cryptochrome. Phase shifts of molecular
oscillations during the larval stage were smaller than those measured by adult
behavior, suggesting molecularly transient responses during development.
PMID- 10677014
TI - Physiological response properties of cat retinal ganglion cells projecting to
suprachiasmatic nucleus.
AB - The aim of this experiment was to characterize the physiological properties of
cat retinal ganglion cells that project to the suprachiasmatic nucleus (SCN).
Retrogradely labeled SCN-projecting ganglion cells were recorded extracellularly
in vitro. For the first time, this study provides crucial information on visual
response properties of ganglion cells in the entrainment circuitry. All recorded
cells gave sustained responses (n = 9). Although most of the cells (n = 8) had an
"on" center receptive field, one cell showed "on-off" center receptive field
properties. The range of receptive field sizes was 2 to 5 deg. For most of the
cells tested, the spectral wavelength that evoked peak responses was 500 nm (3
out of 5 cells). All recorded cells (n = 9) preferred still or extremely slow
moving stimuli (3.3 deg/s). These results indicate that cat SCN-projecting cells
receive inputs from conventional photoreceptors. The hypothesis that both
conventional and cryptochromic photoreceptors are involved in transferring photic
signals is discussed.
PMID- 10677015
TI - The suprachiasmatic nucleus in organotypic slice cultures of the common vole
(Microtus arvalis): comparison of development with rat and hamster and the effect
of age.
AB - The intrinsic properties of the suprachiasmatic nucleus (SCN), the site of the
main circadian pacemaker in mammals, have recently been studied in vitro by means
of organotypic slice culturing. So far, only neonatal rats and mice have been
used for such developmental and functional analyses of the isolated pacemaker.
Here, the authors present a comparative developmental study of the SCN of voles,
rats, and hamsters in organotypic slice cultures. In contrast to strictly
circadian organization of behavior in rats and hamsters, common voles (Microtus
arvalis) are characterized by large variability in the strength of circadian
organization of behavior. It is not known to what extent this variability is
reflected in the intrinsic features of the SCN. Cultures were prepared from rat,
hamster, and vole pups (6 to 9 days old) for the purpose of species comparison.
In addition, the authors studied the relation between age and development in
cultures from pup (7 to 10 days old), juvenile (15 to 16 days old), and young
adult (1 to 2 months old) voles. In contrast to the situation in rat and hamster,
the most striking feature in neonatal voles is the variability in shape of the
final, fully developed culture and its poor resemblance with the in vivo SCN. The
SCN of adult voles, however, could be cultured successfully while retaining its
morphological organization seen in situ. Phase-contrast microscopy and
immunocytochemical staining for vasopressin and glial fibrillary acidic protein
revealed that cultures of pup and juvenile voles still have potential for
neurogenesis and morphological reorganization. Young voles, therefore, can serve
as a model to study the developmental establishment of a functional circadian
pacemaker, while adult voles allow the study of intrinsic pacemaker properties in
relation to previously recorded behavior of the donor and aging-related pacemaker
dysfunction.
PMID- 10677016
TI - Exogenous melatonin reduces the resynchronization time after phase shifts of a
nonphotic zeitgeber in the house sparrow (Passer domesticus).
AB - Continuous melatonin administration via silastic implants accelerates the
resynchronization of the circadian locomotor activity rhythm in house sparrows
(Passer domesticus) after exposure to phase shifts of a weak light-dark cycle.
Constant melatonin might induce this effect either by increasing the sensitivity
of the visual system to a light zeitgeber or by reducing the degree of self
sustainment of the circadian pacemaker. To distinguish between these two possible
mechanisms, two groups of house sparrows, one carrying melatonin implants and the
other empty implants, were kept in constant dim light and subjected to advance
and delay shifts of a 12-h feeding phase. The resynchronization times of their
circadian feeding rhythm following the phase shifts were significantly shorter
when the birds carried melatonin implants than when they carried empty implants.
In a second experiment, melatonin-implanted and control birds were released into
food ad libitum conditions 2 days after either a delay or an advance phase shift.
The number of hours by which the activity rhythms had been shifted on the second
day in food ad libitum conditions was assessed. Melatonin-implanted house
sparrows had significantly larger phase shifts in their circadian feeding rhythm
than control birds. This is in accordance with the first experiment since a
larger phase shift at a given time reflects accelerated resynchronization.
Additionally, the second experiment also excludes any possible masking effects of
the nonphotic zeitgeber. In conclusion, constant melatonin accelerates
resynchronization even after phase shifts of a nonphotic zeitgeber, indicating
that constant high levels of melatonin can reduce the degree of self-sustainment
of the circadian pacemaker independent of any effects on the photoreceptive
system.
PMID- 10677017
TI - Restricted daytime feeding attenuates reentrainment of the circadian melatonin
rhythm after an 8-h phase advance of the light-dark cycle.
AB - It is well established that in the absence of photic cues, the circadian rhythms
of rodents can be readily phase-shifted and entrained by various nonphotic
stimuli that induce increased levels of locomotor activity (i.e.,
benzodiazepines, a new running wheel, and limited food access). In the presence
of an entraining light-dark (LD) cycle, however, the entraining effects of
nonphotic stimuli on (parts of) the circadian oscillator are far less clear. Yet,
an interesting finding is that appropriately timed exercise after a phase shift
can accelerate the entrainment of circadian rhythms to the new LD cycle in both
rodents and humans. The present study investigated whether restricted daytime
feeding (RF) (1) induces a phase shift of the melatonin rhythm under entrained LD
conditions and (2) accelerates resynchronization of circadian rhythms after an 8
h phase advance. Animals were adapted to RF with 2-h food access at the projected
time of the new dark onset. Before and at several time points after the 8-h phase
advance, nocturnal melatonin profiles were measured in RF animals and animals on
ad libitum feeding (AL). In LD-entrained conditions, RF did not cause any
significant changes in the nocturnal melatonin profile as compared to AL.
Unexpectedly, after the 8-h phase advance, RF animals resynchronized more slowly
to the new LD cycle than AL animals. These results indicate that prior
entrainment to a nonphotic stimulus such as RF may "phase lock" the circadian
oscillator and in that way hinder resynchronization after a phase shift.
PMID- 10677018
TI - Probing the circadian pacemaker of a mouse using two light pulses.
AB - In two separate sets of experiments, the phases of the locomotor activity rhythm
of the nocturnal field mouse Mus booduga were probed using two light pulses
(LPs). In the first set of experiments, the circadian pacemaker underlying the
locomotor activity rhythm was perturbed at circadian time 14 (CT 14) using a
resetting light pulse LP1 of 1000 lux intensity and 15 min duration. The phases
of the resetting pacemaker were then probed at all even CTs between CT 16 and CT
14 using a PRC probing light pulse LP2 of equal strength. The "LP2 PRC" thus
obtained was then compared with the single light pulse PRC in terms of the area
under delay (D) and advance (A) zones of the PRCs. The time course and waveform
of the two LP PRCs suggest that the LP2 PRC resembled the single LP PRC,
displaced by 2 h toward the right. The LP1 PRC had smaller D compared to the
single LP PRC (p = 0.007), whereas both the PRCs had A of equal magnitude (p =
0.23). This suggests that the pacemaker phase shifts rapidly after LP
perturbations. In the second set of experiments, the LP1 was administered at CT
14. The phase of the pacemaker was then perturbed on day 1 (next cycle after LP1)
either 2 h after activity onset (at ca. CT 14 of the transient cycle) or 8 h
after activity onset (at ca. CT 20 of the transient cycle) using an LP2 of equal
strength. It was observed that the steady-state phase shifts evoked by
positioning an LP2, 2 h after activity onset, were positively correlated with the
phase shifts observed on day 1. The steady-state phase shifts observed, when the
LP2 was positioned, 8 h after activity onset, were negatively correlated with the
phase shifts observed on day 1. These results suggest that the transient cycles
do not mirror the state of the pacemaker oscillator.
PMID- 10677019
TI - Identifying components of Max Factor.
PMID- 10677020
TI - Getting the membrane into shape for endocytosis.
PMID- 10677021
TI - Siesta-time is in the genes.
PMID- 10677022
TI - The binding problem.
PMID- 10677023
TI - The psychophysical evidence for a binding problem in human vision.
PMID- 10677024
TI - The role of neural mechanisms of attention in solving the binding problem.
PMID- 10677025
TI - The temporal correlation hypothesis of visual feature integration: still alive
and well.
PMID- 10677026
TI - Neuronal synchrony: a versatile code for the definition of relations?
PMID- 10677027
TI - Synchrony unbound: a critical evaluation of the temporal binding hypothesis.
PMID- 10677028
TI - Specialized representations in visual cortex: a role for binding?
PMID- 10677029
TI - Are cortical models really bound by the "binding problem"?
PMID- 10677030
TI - The what and why of binding: the modeler's perspective.
PMID- 10677031
TI - Solutions to the binding problem: progress through controversy and convergence.
PMID- 10677032
TI - BMPs as mediators of roof plate repulsion of commissural neurons.
AB - During spinal cord development, commissural (C) neurons, located near the dorsal
midline, send axons ventrally and across the floor plate (FP). The trajectory of
these axons toward the FP is guided in part by netrins. The mechanisms that guide
the early phase of C axon extension, however, have not been resolved. We show
that the roof plate (RP) expresses a diffusible activity that repels C axons and
orients their growth within the dorsal spinal cord. Bone morphogenetic proteins
(BMPs) appear to act as RP-derived chemorepellents that guide the early
trajectory of the axons of C neurons in the developing spinal cord: BMP7 mimics
the RP repellent activity for C axons in vitro, can act directly to collapse C
growth cones, and appears to serve an essential function in RP repulsion of C
axons.
PMID- 10677033
TI - Endophilin/SH3p4 is required for the transition from early to late stages in
clathrin-mediated synaptic vesicle endocytosis.
AB - Endophilin/SH3p4 is a protein highly enriched in nerve terminals that binds the
GTPase dynamin and the polyphosphoinositide phosphatase synaptojanin, two
proteins implicated in synaptic vesicle endocytosis. We show here that antibody
mediated disruption of endophilin function in a tonically stimulated synapse
leads to a block in the invagination of clathrin-coated pits adjacent to the
active zone and therefore to a block of synaptic vesicle recycling. We also show
that in a cell-free system, endophilin is not associated with clathrin coats and
is a functional partner of dynamin. Our findings suggest that endophilin is part
of a biochemical machinery that acts in trans to the clathrin coat from early
stages to vesicle fission.
PMID- 10677034
TI - Integration of NPY, AGRP, and melanocortin signals in the hypothalamic
paraventricular nucleus: evidence of a cellular basis for the adipostat.
AB - Energy stores are held relatively constant in many mammals. The circuitry
necessary for maintaining energy homeostasis should (1) sense the amount of
energy stored in adipose tissue, (2) sense and integrate the multiple opposing
signals regarding nutritional state, and (3) provide output regulating energy
intake and expenditure to maintain energy homeostasis. We demonstrate that
individual neurons within the paraventricular nucleus of the hypothalamus (PVH)
are capable of detection and integration of orexigenic (neuropeptide Y [NPY]) and
anorexigenic (melanocortin) signals, that NPY and melanocortins are functional
antagonists of each other within the PVH in the regulation of feeding behavior,
and that melanocortin administration within the PVH regulates both feeding
behavior and energy expenditure. These data provide a cellular basis for the
adipostat within neurons in the PVH that appear to be jointly regulated by NPY-
and melanocortin-responsive neurons.
PMID- 10677035
TI - Identification of maxillary factor, a maxillary process-derived chemoattractant
for developing trigeminal sensory axons.
AB - Trigeminal sensory axons project to several epithelial targets, including those
of the maxillary and mandibular processes. Previous studies identified a
chemoattractant activity, termed Maxillary Factor, secreted by these processes,
which can attract developing trigeminal axons in vitro. We report that Maxillary
Factor activity is composed of two neurotrophins, neurotrophin-3 (NT-3) and Brain
Derived Neurotrophic Factor (BDNF), which are produced by both target epithelium
and pathway mesenchyme and which are therefore more likely to have a trophic
effect on the neurons or their axons than to provide directional information, at
least at initial stages of trigeminal axon growth. Consistent with this, the
initial trajectories of trigeminal sensory axons are largely or completely normal
in mice deficient in both BDNF and NT-3, indicating that other cues must be
sufficient for the initial stages of trigeminal axon guidance.
PMID- 10677036
TI - Learned movements elicited by direct stimulation of cerebellar mossy fiber
afferents.
AB - Definitive evidence is presented that the conditioned stimulus (CS) in classical
conditioning reaches the cerebellum via the mossy fiber system. Decerebrate
ferrets received paired forelimb and periocular stimulation until they responded
with blinks to the forelimb stimulus. When direct mossy fiber stimulation was
then given, the animals responded with conditioned blinks immediately, that is,
without ever having been trained to the mossy fiber stimulation. Antidromic
activation was prevented by blocking mossy fibers with lignocaine ventral to the
stimulation site. It could be excluded that cerebellar output functioned as the
CS. Analysis of latencies suggests that conditioned responses (CRs) are not
generated by mossy fiber collaterals to the deep nuclei. Hence, the memory trace
is probably located in the cerebellar cortex.
PMID- 10677037
TI - Differential processing of objects under various viewing conditions in the human
lateral occipital complex.
AB - The invariant properties of human cortical neurons cannot be studied directly by
fMRI due to its limited spatial resolution. Here, we circumvented this limitation
by using fMR adaptation, namely, reduction of the fMR signal due to repeated
presentation of identical images. Object-selective regions (lateral occipital
complex [LOC]) showed a monotonic signal decrease as repetition frequency
increased. The invariant properties of fMR adaptation were studied by presenting
the same object in different viewing conditions. LOC exhibited stronger fMR
adaptation to changes in size and position (more invariance) compared to
illumination and viewpoint. The effect revealed two putative subdivisions within
LOC: caudal-dorsal (LO), which exhibited substantial recovery from adaptation
under all transformations, and posterior fusiform (PF/LOa), which displayed
stronger adaptation. This study demonstrates the utility of fMR adaptation for
revealing functional characteristics of neurons in fMRI studies.
PMID- 10677038
TI - Effects of lexicality, frequency, and spelling-to-sound consistency on the
functional anatomy of reading.
AB - Functional neuroimaging was used to investigate three factors that affect reading
performance: first, whether a stimulus is a word or pronounceable non-word
(lexicality), second, how often a word is encountered (frequency), and third,
whether the pronunciation has a predictable spelling-to-sound correspondence
(consistency). Comparisons between word naming (reading) and visual fixation
scans revealed stimulus-related activation differences in seven regions. A left
frontal region showed effects of consistency and lexicality, indicating a role in
orthographic to phonological transformation. Motor cortex showed an effect of
consistency bilaterally, suggesting that motoric processes beyond high-level
representations of word phonology influence reading performance. Implications for
the integration of these results into theoretical models of word reading are
discussed.
PMID- 10677039
TI - How a circadian clock adapts to seasonal decreases in temperature and day length.
AB - We show that a thermosensitive splicing event in the 3' untranslated region of
the mRNA from the period (per) gene plays an important role in how a circadian
clock in Drosophila adapts to seasonally cold days (low temperatures and short
day lengths). The enhanced splicing of this intron at low temperatures advances
the steady state phases of the per mRNA and protein cycles, events that
significantly contribute to the preferential daytime activity of flies on cold
days. Because the accumulation of PER is also dependent on the photosensitive
TIMELESS (TIM) protein, long photoperiods partially counteract the cold-induced
advances in the oscillatory mechanism by delaying the daily increases in the
levels of TIM. Our findings also indicate that there is a temperature-dependent
switch in the molecular logic governing cycles in per mRNA levels.
PMID- 10677040
TI - Serotonin inhibition of synaptic transmission: Galpha(0) decreases the abundance
of UNC-13 at release sites.
AB - We show that serotonin inhibits synaptic transmission at C. elegans neuromuscular
junctions, and we describe a signaling pathway that mediates this effect. Release
of acetylcholine from motor neurons was assayed by measuring the sensitivity of
intact animals to the acetylcholinesterase inhibitor aldicarb. By this assay,
exogenous serotonin inhibited acetylcholine release, whereas serotonin
antagonists stimulated release. The effects of serotonin on synaptic transmission
were mediated by GOA-1 (a Galpha0 subunit) and DGK-1 (a diacylglycerol [DAG]
kinase), both of which act in the ventral cord motor neurons. Mutants lacking goa
1 G(alpha)0 accumulated abnormally high levels of the DAG-binding protein UNC-13
at motor neuron nerve terminals, suggesting that serotonin inhibits synaptic
transmission by decreasing the abundance of UNC-13 at release sites.
PMID- 10677041
TI - Retention of supraspinal delta-like analgesia and loss of morphine tolerance in
delta opioid receptor knockout mice.
AB - Gene targeting was used to delete exon 2 of mouse DOR-1, which encodes the delta
opioid receptor. Essentially all 3H-[D-Pen2,D-Pen5]enkephalin (3H-DPDPE) and 3H
[D-Ala2,D-Glu4]deltorphin (3H-deltorphin-2) binding is absent from mutant mice,
demonstrating that DOR-1 encodes both delta1 and delta2 receptor subtypes.
Homozygous mutant mice display markedly reduced spinal delta analgesia, but
peptide delta agonists retain supraspinal analgesic potency that is only
partially antagonized by naltrindole. Retained DPDPE analgesia is also
demonstrated upon formalin testing, while the nonpeptide delta agonist BW373U69
exhibits enhanced activity in DOR-1 mutant mice. Together, these findings suggest
the existence of a second delta-like analgesic system. Finally, DOR-1 mutant mice
do not develop analgesic tolerance to morphine, genetically demonstrating a
central role for DOR-1 in this process.
PMID- 10677042
TI - A novel nociceptor signaling pathway revealed in protein kinase C epsilon mutant
mice.
AB - There is great interest in discovering new targets for pain therapy since current
methods of analgesia are often only partially successful. Although protein kinase
C (PKC) enhances nociceptor function, it is not known which PKC isozymes
contribute. Here, we show that epinephrine-induced mechanical and thermal
hyperalgesia and acetic acid-associated hyperalgesia are markedly attenuated in
PKCepsilon mutant mice, but baseline nociceptive thresholds are normal. Moreover,
epinephrine-, carrageenan-, and nerve growth factor- (NGF-) induced hyperalgesia
in normal rats, and epinephrine-induced enhancement of tetrodotoxin-resistant Na+
current (TTX-R I(Na)) in cultured rat dorsal root ganglion (DRG) neurons, are
inhibited by a PKCepsilon-selective inhibitor peptide. Our findings indicate that
PKCepsilon regulates nociceptor function and suggest that PKCepsilon inhibitors
could prove useful in the treatment of pain.
PMID- 10677043
TI - Activation of a TRPC3-dependent cation current through the neurotrophin BDNF.
AB - Nonvoltage-gated cation currents, which are activated following stimulation of
phospholipase C (PLC), appear to be major modes for Ca2+ and Na+ entry in
mammalian cells. The TRPC channels may mediate some of these conductances since
their expression in vitro leads to PLC-dependent cation influx. We found that the
TRPC3 protein was highly enriched in neurons of the central nervous system (CNS).
The temporal and spatial distribution of TRPC3 paralleled that of the
neurotrophin receptor TrkB. Activation of TrkB by brain-derived nerve growth
factor (BDNF) led to production of a PLC-dependent, nonselective cation
conductance in pontine neurons. Evidence is provided that TRPC3 contributes to
this current in vivo. Thus, activation of TrkB and PLC leads to a TRPC3-dependent
cation influx in CNS neurons.
PMID- 10677044
TI - Nuclear accumulation of truncated atrophin-1 fragments in a transgenic mouse
model of DRPLA.
AB - Dentatorubral and pallidoluysian atrophy (DRPLA) is a member of a family of
progressive neurodegenerative diseases caused by polyglutamine repeat expansion.
Transgenic mice expressing full-length human atrophin-1 with 65 consecutive
glutamines exhibit ataxia, tremors, abnormal movements, seizures, and premature
death. These mice accumulate atrophin-1 immunoreactivity and inclusion bodies in
the nuclei of multiple populations of neurons. Subcellular fractionation revealed
120 kDa nuclear fragments of mutant atrophin-1, whose abundance increased with
age and phenotypic severity. Brains of DRPLA patients contained apparently
identical 120 kDa nuclear fragments. By contrast, mice overexpressing atrophin-1
with 26 glutamines were phenotypically normal and did not accumulate the 120 kDa
fragments. We conclude that the evolution of neuropathology in DRPLA involves
proteolytic processing of mutant atrophin-1 and nuclear accumulation of truncated
fragments.
PMID- 10677045
TI - Infantile colic: aetiology and prognosis.
PMID- 10677046
TI - Towards a "new beginning": dietary fat restrictions in infancy?
PMID- 10677047
TI - Long-term coping in childhood cancer survivors--influence of illness, treatment
and demographic factors.
PMID- 10677048
TI - Using a large-scale screening method to detect language disability in three-year
olds.
PMID- 10677049
TI - Does breastfeeding increase thymus size?
PMID- 10677050
TI - Infantile colic. Follow-up at four years of age: still more "emotional".
AB - This paper presents a follow-up at 4 y of formerly colicky infants and controls,
with respect to behaviour, temperament, eating and sleeping habits, psychosomatic
complaints, number of hospital stays, growth and "family climate". There were no
differences between the two groups in most parameters studied. However, ex
colicky children displayed more negative emotions according to the temperament
scale. There were also more negative moods during meals, and more reported
stomach-ache. Although relationships regarding crying and mother-infant
interaction remain extremely complex, the findings point toward a possible
temperamental contribution to the pathogenesis of the infantile colic syndrome.
PMID- 10677051
TI - Effectiveness of casein hydrolysate feedings in infants with colic.
AB - This study found that two casein hydrolysate formulas varying in composition were
equally effective in managing colicky symptoms associated with protein
sensitivity. Both hydrolysate formulas were associated with a significant,
comparable reduction in crying duration and intensity from baseline in 15 of 22
infants with complete data. Subsequent challenge data suggest that the population
studied were infants experiencing colicky symptoms due to protein sensitivity. A
greater proportion of infants showed a positive reaction (> or = 1.5 h of
crying/d) to the protein challenges than the placebo challenge, and crying was
rated as more intense during whey and milk protein challenges.
PMID- 10677052
TI - Treatment of infant colic with amino acid-based infant formula: a preliminary
study.
AB - Infant colic, a common disorder of infancy, is characterized by excessive crying
and fussing. In this preliminary study we examined whether Neocate, an amino acid
based formula, would be accepted by formula-fed infants with colic, 3-7 wk of
age, and whether Neocate would improve their symptoms. Six infants with colic
were studied using Barr-type infant behavior diaries for 3-6 d on their current
formula and then for 5-17 d on Neocate exclusively. All infants tolerated Neocate
well and all improved, usually within 1-2 d. The total time spent crying and
fussing was reduced by an average of 45%, representing a decrease of 1.0 to 5.2 h
daily. After colic symptoms improved, infants were challenged with oral doses of
75 mg of bovine IgG at a 1 mg/ml concentration in order to assess its potential
role in colic. Bovine IgG challenges resulted in increased crying and fussing
behavior, suggesting that this protein may be etiologically important.
PMID- 10677053
TI - Fat intake and metabolism in Swedish and Italian infants.
AB - The purpose of the study was to compare fat intake and metabolism between two
infant populations from Sweden and Italy given breast milk or similar infant
formulas, but different weaning foods. Nutrient intake and fat metabolism were
studied prospectively from 3-12 mo in 68 Swedish and 46 Italian healthy infants,
breastfed or given similar infant formulas in combination with Swedish or
Mediterranean weaning foods. Although nutrient intake and fat metabolism were
similar at 6 mo, fat intake was lower at 12 mo in the Italian than in the Swedish
formula group (p < 0.001). At 6 and 12 mo, higher dietary ratios of
monounsaturated to saturated fatty acids (p < 0.01 and p < 0.001, respectively),
and monounsaturated to polyunsaturated fatty acids (p < 0.05, p < 0.001) were
found in the Italian than in the Swedish formula group. Total cholesterol and
apolipoprotein B were lower at 6 mo (p < 0.01) in Italian breastfed infants than
in Swedish ones. Lower concentrations at 6 and 12 mo of total cholesterol (p <
0.05, p < 0.05, respectively), apolipoprotein B (p < 0.05, p < 0.01) and
triglycerides (p < 0.001, p < 0.01), and of apolipoprotein A1 (p < 0.01) at 12
mo, were found in the Italian formula group than in the Swedish one. In
conclusion, plasma total cholesterol, apolipoprotein B and triglycerides were
found to be lower in Italian infants than in Swedish infants during the second
half of infancy. These findings may partly result from differences in fat
compositions between Swedish and Mediterranean weaning diets and in total fat
intake in late infancy. Differences in duration of breastfeeding and possibly in
breast milk composition may also have influenced our results.
PMID- 10677054
TI - Prediction of growth response in prepubertal children treated with growth hormone
for idiopathic growth hormone deficiency.
AB - Several multiple regression models have been developed to predict the first-year
growth response to human growth hormone (hGH) in children with growth hormone
deficiency (GHD). It was the aim of this study to analyse the significance of
various growth parameters for a height prediction model. Data from 148
prepubertal children with idiopathic GHD were evaluated. The prediction model was
developed by means of univariate and stepwise linear regression analysis and an
"all possible" regression approach using Mallow's C(p) statistics. Six out of
eight selected variables had a significant influence on the first-year growth
rate. The most important parameter was the difference between target height SDS
and height SDS at the start of therapy (THSDS-HSDSCO), accounting for 23.95% and
25.74% of the variability. No other single variable or combination of variables
was more informative than the variable THSDS-HSDSCO alone. From these data,
growth velocity for the first year of hGH treatment was estimated as 1.106 (THSDS
HSDSCO) + 6.8 cm/y +/- 2.2 cm (SE), allowing a prediction for different intervals
between THSDS and HSDSCO. This equation was validated in a small group of 18 GHD
patients demonstrating a predicted vs. observed first-year growth rate of 9.4 +/-
1.1 vs. 9.5 +/- 2.6 cm/y. We conclude that the difference between THSDS and
height SDS at the start of therapy is an important predictor of the first-year
growth response in children treated with hGH for idiopathic GHD. Unlike in
previous studies, additional parameters did not increase predictability.
PMID- 10677055
TI - Comparison of the growth-promoting effects of insulin-like growth factor I and
growth hormone in the early years of life.
AB - AIMS: Four infants with isolated growth hormone deficiency (IGHD) and five with
Laron syndrome (LS) were studied. Birth length ranged from -2.5 to -4.5 SDS in
both groups. RESULTS: Untreated IGHD children decreased in length from -2.5 to
5.2 SDS at 1 y and to -5.7 SDS at 2 y. Human growth hormone (hGH) treatment (0.07
U/kg/d) increased height by 1.2-2.4 SDS in 3 y. Untreated children with LS
decreased in length from -3.5 to -6.5 SDS. Insulin-like growth factor (IGF)-I
treatment (150-200 microg/kg/d) in 3 LS patients increased height by 0.5-1.5 SDS
in 3 y. All untreated infants had borderline or below normal head circumferences.
Both treatments induced a rapid catch-up in head size. In the two untreated LS
patients, head circumference remained subnormal. CONCLUSIONS: Despite similar
birth length, infants with IGHD responded better to hGH in terms of linear growth
than did infants with LS to IGF-I, whereas the response in brain growth was
similar.
PMID- 10677056
TI - Association of serum low-density lipoprotein metabolism with oestrogen receptor
gene polymorphisms in healthy children.
AB - The aim of this study was to reveal the association of serum lipid and
apolipoprotein levels with oestrogen receptor (ER) Xba I and Pvu II polymorphisms
in 102 healthy Japanese school children (56M, 46F) aged 10-15 y. Each genotype of
the genomic DNA extracted from peripheral leukocytes was determined using
polymerase chain reaction and digestion with Xba I or Pvu II. The genotypes were
coded as either X1 or X2 (Xba I) and P1 or P2 (Pvu II), when XI, P1 signified the
absence of and X2, P2 the presence of restriction sites. The fasting serum total
cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein (LDL)
cholesterol, triglyceride and apolipoproteins A1, B and E were measured. In the
Xba I polymorphism, LDL cholesterol, apolipoprotein B levels of the XI/XI
genotype were significantly higher than those of the others. The other lipid and
apolipoprotein levels were not significantly different among the three genotypes.
In the Pvu II polymorphism, there were no significant differences in serum lipids
and lipoproteins among the three genotypes. This study reveals that Xba I
polymorphisms are related to LDL metabolism. These findings support previous
reports that the LDL-lowering effects of oestrogen occur through the ER (alpha)
pathway. The Xba I polymorphism may be one of the genetic factors in the control
of LDL metabolism.
PMID- 10677057
TI - Islet cell antibody frequency differs from that of glutamic acid decarboxylase
antibodies/IA2 antibodies after diagnosis of diabetes.
AB - The combination of glutamic acid decarboxylase (GAD) 65 antibodies (GADA) and
protein tyrosine phosphatase-like protein IA2 antibodies (IA2-ab), measured by
radioligand binding assays, has been suggested to replace islet cell antibodies
(ICA), measured by indirect immunofluorescence, as a marker for autoimmune type I
diabetes. The aim of this study was to compare the frequency of ICA and GADA
and/or IA2-ab not only at, but also after the diagnosis of diabetes. ICA, GADA
and IA2-ab were therefore assessed at and up to 11 y after the diagnosis of
diabetes in 86 children (1-15-y-old). At diagnosis, ICA were found in 74 (86%)
and GADA and/or IA2-ab in 79 (92%) of the diabetic children. Hence, there was no
major difference in frequency between ICA and GADA and/or IA2-ab at diagnosis of
diabetes. At follow-up, however, ICA were less frequent than GADA and/or IA2-ab;
1-3 y after diagnosis ICA were found in 12 (44%) and GADA and/or IA2-ab in 24
(89%) of 27 children (p=0.001); 4-6 y after diagnosis ICA were found in 7 (24%)
and GADA and/or IA2-ab in 27 (93%) of 29 children (p < 0.0001); 7-11 y after
diagnosis ICA were found in 4 (13%) and GADA and/or IA2-ab in 21 (70%) of 30
children (p < 0.0001). We conclude that the frequency of ICA does not always
correspond to that of GADA and/or IA2-ab. Many years after diagnosis of diabetes,
measurements of GADA and IA2-ab, but not ICA, detect autoimmunity in high
frequency.
PMID- 10677058
TI - Visual event-related potentials in children with phenylketonuria.
AB - Visual event-related potentials (ERPs) were examined in 16 children (aged 5-14 y)
with phenylketonuria (PKU) and 16 age- and sex-matched controls. Lifetime median
measures of phenylalanine (Phe) were 230-460 micromol/l. The most recent Phe
levels were 56-624 micromol/l. ERPs were recorded whilst the children performed a
discrimination task. All stimuli were square wave gratings degree, which appeared
for 33 ms. A response to an infrequent grating that differed in orientation or
spatial frequency was required. The older children with PKU had a delay in the
first peak (P1) of the ERP, and age-related changes in the amplitude of P1. There
was attenuation of the second peak across age groups in PKU. There was no
evidence of reduced response accuracy or longer reaction times in children with
PKU. Latencies of the cognitive P3 were not delayed in PKU. The delayed early
peaks are consistent with previous studies that have shown delayed visual evoked
potentials in PKU. The lack of differences in reaction time and P3 may be due to
relatively good Phe control in children with PKU, or to the simplicity of the
task. Suggestions are made for future ERP studies of PKU.
PMID- 10677059
TI - Gait disturbance interpreted as cerebellar ataxia after MMR vaccination at 15
months of age: a follow-up study.
AB - Measles, mumps and rubella (MMR) vaccination was included in the Danish childhood
vaccination programme in 1987. During the following 10-y period, 550 notification
records of adverse events after MMR vaccination at 15 mo of age have been
registered, and a total of 41 notifications have included "gait disturbance".
This corresponds to a frequency of 8 per 100,000 doses of MMR vaccine used for 15
mo-old children. The symptoms and signs are characteristic of cerebellar ataxia.
In 28 notifications, the descriptions by the doctors included only "gait
disturbance", while in 13 an additional interpretation was included. Thirty-two
parents (78%) filled in a questionnaire and 26 (63%) agreed to participate in a
clinical follow-up study. The gait disturbance symptoms mainly occurred 7-14 d
after the vaccination, and the duration was median 1-2 wk (range 1 d to more than
4 mo). One-third of the children had symptoms lasting more than 2 wk.
Significantly more children with long duration of symptoms had some kind of
complaint or clinical signs at the follow-up in 1997. Gait disturbance registered
after MMR vaccination seems to be more frequent than hitherto reported. Most
cases are mild and short-lasting and a longer duration of symptoms seems to be
predictive of late sequelae. A clinical diagnosis of cerebellar ataxia after MMR
and the exact frequency of this adverse event remains to be tested in prospective
studies.
PMID- 10677060
TI - Magnetocardiographic determination of the developmental changes in PQ, QRS and QT
intervals in the foetus.
AB - In order to determine developmental changes in atrioventricular (PQ), ventricular
depolarizing (QRS) and QT intervals of the foetal heart, we recorded foetal
magnetocardiographic waveforms using a superconducting quantum interference
device system in a magnetically shielded room in 150 uncomplicated foetuses of
gestational age >20 wk. Recording of the QRS waveform was successful in 128 (85%)
of the subjects, based on unaveraged tracings. After signal averaging of the data
from these 128 cases, P waves were recognized in 102 (68%) subjects and T waves
in 64 (43%). The QRS interval, ranging from 32-74 ms, showed a positive linear
correlation with the gestational age, which probably reflects an increase in the
number and size of myocardial cells. The PQ interval showed low correlation with
the gestational age, and was rather constant, with an average value of 100 ms.
The QT interval ranged from 180-302 ms, and tended to be slightly shorter during
early gestation. Although the success rate of measuring the PQ and QT intervals
was unsatisfactory for this methodology to prevail in a clinical setting, these
values provide the basis for in utero non-invasive investigation of foetal
cardiac activity by magnetocardiography.
PMID- 10677061
TI - Newborn infants' cry after heel-prick: analysis with sound spectrogram.
AB - The aim of the study was to test the hypothesis that a newborn infant's cry can
be used in conjunction with an instrument to measure pain. Crying due to pain was
analysed after a heel-prick stimulus. In a prospective, descriptive study, 50
healthy newborn infants were subjected to a heel-prick for phenylketonuria
screening. Their cries of pain were recorded and analysed. Duration of the crying
sound was analysed and, using a sound spectrogram, the fundamental frequency and
the cry melody of the first five cry sounds were analysed. The analysis showed
that the crying sound after the painful stimulus of the heel-prick had a
significantly higher fundamental frequency and lasted longer at the first than at
the fifth cry. The first cry had a more varied crying melody than the fifth.
There were large differences between individual cries from a single infant, as
well as in the duration of each cry, total crying time, and fundamental
frequencies between infants. While the first cry was more like a cry of pain, the
fifth cry more resembled crying for reasons other than pain. The results suggest
that newborn infants react to pain in a recognizable way. However, other stimuli
may cause a similar reaction. Crying can therefore be used to measure pain in
newborn infants only when the cause of crying is known.
PMID- 10677062
TI - Intrauterine growth retardation and brainstem auditory-evoked response in preterm
infants.
AB - Intrauterine growth retardation is frequently associated with intrauterine
undernutrition, and can deleteriously affect brain function. Twenty-eight
premature small for gestational age infants were compared with 28 premature
appropriate for gestational age infants to determine whether intrauterine growth
retardation was associated with abnormalities in the auditory pathway in the
early neonatal period. The auditory pathway was studied between 4-18 wk of life
by analysis of brainstem auditory-evoked potentials elicited by a 10/s 75 decibel
above normal adult hearing level (dB nHL) click stimulus presented at the
infants' ears. Peak latencies of components I, III and V, and interpeak latencies
I-III, III-V and I-V, yielded no statistically significant differences between
groups. The present study indicates that intrauterine growth-retarded premature
infants may not have abnormalities of brainstem auditory-evoked response in the
early neonatal period.
PMID- 10677063
TI - Unilateral posthaemorrhagic hydrocephalus in the neonatal period or later in
infancy.
AB - Five infants who developed unilateral hydrocephalus associated with antenatal or
perinatal intraventricular haemorrhage (IVH) in the neonatal period or later in
infancy are reported. Unilateral hydrocephalus occurred following discharge home
in four of our five cases, two of whom had been treated during the neonatal
period with either serial lumbar punctures or punctures from a Rickham reservoir.
An obstruction at the level of the foramen of Monro following a large
subependymal matrix bleed appeared to be the underlying aetiology. These data
suggest that infants who suffer a predominantly unilateral IVH, with or without
parenchymal involvement, can subsequently develop unilateral hydrocephalus.
Cranial ultrasound examinations should be repeated at regular intervals during
the first year of life, as unilateral hydrocephalus can still develop after a
period of apparent stabilization.
PMID- 10677064
TI - Neonatal micrognathia is associated with small upper airways on radiographic
measurement.
AB - In order to determine if infants with clinical micrognathia identified in the
newborn period have smaller upper airways than do normal infants, and if their
airway size is related to risk of later apnoea, respiration-timed upper airway
radiographic measurements were performed in 21 asymptomatic neonates with
clinical micrognathia. Their radiographic measurements were compared with those
of a previously reported cohort of 35 normal infants. The micrognathic infants
and a control group of 27 infants referred for parental anxiety were followed for
6 mo on home apnoea monitors. Sleep apnoea at home requiring stimulation by the
parents occurred in 6 of 7 infants with micrognathia associated with craniofacial
anomalies, 9 of 14 (64%) infants with isolated micrognathia, but only 1 of the 27
control infants (p < 0.001). Upper airway measurements at term of the infants
with isolated micrognathia who later experienced apnoea were significantly
smaller than either those of normal infants (p < 0.01) or of micrognathic infants
who did not have apnoea requiring stimulation (p < 0.05). In conclusion, upper
airway measurements on timed lateral radiographs in asymptomatic micrognathic
infants at term (corrected age) revealed them to be smaller than those of normal
infants. Narrower upper airways were associated with increased risk of subsequent
apnoea requiring stimulation.
PMID- 10677065
TI - Are data on the prevalence and duration of breastfeeding reliable? The case of
Italy.
AB - Many countries produce data on the prevalence and duration of breastfeeding, but
are they reliable? We reviewed 16 studies on breastfeeding in Italy published
after 1990. They report a prevalence of breastfeeding at and around birth ranging
from 66% to 91%, decreasing to 17-52% at 4 mo and 28-36% at 6 mo. Most studies
refer to a non-representative sample of the Italian population. Two studies used
standard definitions of breastfeeding, but their results are difficult to
interpret or cannot be generalized. Five other studies used non-standard
definitions that undermine the interpretation of results. The remaining nine
studies used no definition at all. All studies used a recall period different
from 24 h, or from the whole hospital stay for breastfeeding at discharge, making
the interpretation of results even more difficult. We conclude that the published
information gives an inaccurate picture of the prevalence and duration of
breastfeeding in Italy, leading to unjustified optimism and inaction. The actual
figures may be lower, as shown by preliminary data from a small Italian region:
using standard definitions and methods during a 9-mo monitoring period, exclusive
breastfeeding averaged 35% at discharge and 23% at about 4 mo of age.
PMID- 10677066
TI - Can severe language disability be identified in three-year-olds? Evaluation of a
routine screening procedure.
AB - This study evaluates the predictability of a new language screening procedure in
3-y-olds. It is used in several Child Health Centres (CHC) in Sweden and has the
character of a field study involving more than 60 CHC nurses. The main questions
concern the (i) development in 3-y-olds assessed as severely language delayed and
(ii) whether there are any earlier unknown severely disabled children identified
at 4 y of age. Ninety-six percent of the original study population participated
in the follow-up. The calculations are based on results from 2237 children. A
well-established screening routine, which has been shown capable of predicting
the risk of not being able to follow expected schooling, and case records were
used as an acceptable proxy outcome measure, pending a better gold standard. In
the group of severely disabled 3-y-olds, sensitivity, specificity and positive
predictive values were 86, 99 and 43%, respectively. Finally, three false
negatives were identified. In light of the present results, continued application
of the 3-y screening is discussed.
PMID- 10677067
TI - Incidence of type I diabetes among children and young adults (0-29 years) in the
province of Badajoz, Spain during 1992 to 1996.
AB - In this study, we determine the incidence of Type I (insulin-dependent) diabetes
mellitus in the 0-29-y-old group in Badajoz (the largest and least developed
province of Spain). We test for differences in incidence by age at diagnosis,
time cluster and sex. Diabetes clinics and periodic review of hospital
administration data provided the primary source of ascertainment. The secondary
independent data source was based on registries of local Diabetic Associations
and guarantee cards of blood glucose meters. Data were collected retrospectively
in the period 1992-95 and prospectively for 1996. During the 5-y period (1992
96), 186 new cases of Type I diabetes were identified. Completeness of
ascertainment was 95%. Average annual incidence (95% CI) for the 0-14, 15-29 and
0-29-y-old groups was 17.6/100,000 (14.5-21.2), 8.8/100,000 (6.9-11.1) and
12.8/100,000 (11-14.7). The highest age-specific annual incidence rate was found
in the 10-14 age group: 23.4/100,000 (17.6-30.4). The incidence in males
(14.7/100,000/y) was higher than in females (10.7/100,000/y). There was a
seasonal onset pattern, with the highest incidence in autumn and winter. October
was the month with the highest number of new cases (29/186). The province of
Badajoz has a moderately high incidence of Type I diabetes in 0-14-y-old
children, similar to that found in other more developed and densely populated
regions of Spain. These data contradict the hypothesis of a decrease in the
incidence of the disease from north to south over Europe.
PMID- 10677068
TI - Long-term coping in childhood cancer survivors: influence of illness, treatment
and demographic background factors.
AB - In 30 survivors of childhood cancer, long-term psychological coping with
experience of disease and treatment was studied in relation to factors associated
with illness, treatment and demographic background. Coping was assessed in a
prior study, in which three groups of varying levels of coping where delineated
(good, 40%; intermediate, 33%; poor, 27%, coping). The present study showed that
poor individual coping was related to diagnosis, a shorter time of continuous
complete remission, more severe illness and treatment impairments, and lower
scores on a test of intellectual abilities. In addition, a longer time of
treatment tended to be followed by poorer coping. However, no association was
found for gender, parents' occupational level, age at illness onset, neuro
cranial irradiation, irradiation dose (total) or age at investigation. A
tentative path-analysis was executed, displaying a model for the relationships
between medical and demographic background variables, and for their influence on
coping. It was concluded that a complex of factors--associated particularly with
severity of disease and treatment--appears to be related to, and affects, coping
with the illness experience. Patients' long-term coping with their illness trauma
is most likely determined by multiple factors. Intellectual capabilities are
related to coping.
PMID- 10677069
TI - Previous breastfeeding does not alter thymic size in infants dying of sudden
infant death syndrome.
AB - The relationship between thymic weights and previous feeding histories was
examined in 294 infants of 37 wk gestation or more dying of sudden infant death
syndrome (SIDS). One hundred and sixty-five infants had been breastfed
exclusively, 89 had been partially breastfed and 40 had never been breastfed. We
found no relationship between thymic weight and type of previous feeding. The
difference between these findings in SIDS and the substantially greater thymic
size previously reported in 4-mo-old breastfed living infants deserves further
study.
PMID- 10677070
TI - Blueberry muffin rash as a presentation of alveolar cell rhabdomyosarcoma in a
neonate.
AB - Soft tissue sarcomas of childhood continue to present problems with pathologic
diagnosis, staging and treatment. Rhabdomyosarcoma, the most common soft tissue
sarcoma, represents 4-8% of all malignant solid tumours in children. We report a
case of congenital alveolar rhabdomyosarcoma who presented with "blueberry
muffin"-like rash. A full-term female infant was noted at birth to have multiple
skin lesions resembling blueberry muffin rash and an abdominal mass in the left
iliac fossa, which appeared to be fixed to the posterior abdominal wall. There
was no enlargement of liver and spleen, but her para-aortic lymph nodes were
enlarged. Biopsy from the mass confirmed the diagnosis of alveolar cell
rhabdomyosarcoma. Molecular investigation for the t (2:13) translocation was
negative. The infant received chemotherapy but died within 1 mo of diagnosis.
PMID- 10677071
TI - Association of oesophageal atresia and hypertrophic pyloric stenosis.
PMID- 10677072
TI - The increased trend of type 1 diabetes mellitus in children (0-14 years) in the
Upper Silesia region of Poland.
PMID- 10677073
TI - Treatment of nocturnal enuresis.
PMID- 10677074
TI - Cystic fibrosis presenting as heat stroke.
PMID- 10677075
TI - Low-carbon silica sorbents for solid-phase extraction.
AB - The applicability of silica gels, modified with cyclic organosiloxanes, in solid
phase extraction (SPE) has been tested. Surface characteristics of the adsorbents
prepared are determined by: elemental analysis, 29Si cross-polarisation magic
angle spinning nuclear magnetic resonance spectroscopy (29Si CP MAS NMR) and
diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The sorbents
with low carbon contents are used for extraction of chlorinated pesticides,
polychlorinated biphenyls and nitro-compounds from water. The properties of the
sorbents are compared with commercial C18 ones. It is shown that the low-carbon
silica SPE sorbents can ensure satisfactory recoveries and reveal some
selectivity.
PMID- 10677076
TI - Use of optimization software to determine rugged analysis conditions in high
performance liquid chromatography.
AB - The ruggedness evaluation of an analytical method is now generally required for
further validation. By considering ruggedness at an early stage of method
development, major disappointments and amount of work could be avoided. This work
shows that the optimization software OSIRIS can be helpful for the
chromatographer during a method development, as it takes into account the method
ruggedness. The ruggedness of the analysis conditions is then evaluated all along
the selectivity optimization procedure. This optimization software belongs to the
interpretive methods that consist of predicting the optimum conditions by
modeling first the solute retention over the parameter space using a minimum
number of preliminary runs. The choice of a response function is studied. This
response function must be able to take into account several individual criteria:
analysis time, minimal resolution and ruggedness of each parameter. Some optimum
separations, determined using a ruggedness criteria or not, are given and
compared in terms of long term repeatability.
PMID- 10677077
TI - Liquid chromatographic resolution of 2-hydroxycarboxylic acids on a new chiral
stationary phase derived from (S)-leucine.
AB - Enantiomers of racemic 2-hydroxycarboxylic acids have been resolved as their O
ethoxycarbonyl pi-basic anilide derivatives on a new chiral stationary phase
(CSP) derived from N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkylamide and the
resolution results have been compared with those on various commercial pi-acidic
CSPs. The resolution results demonstrate that the new CSP derived from N-(3,5
dinitrobenzoyl)leucine N-phenyl N-alkylamide is most effective among the five
CSPs tested for the resolution of 2-hydroxycarboxylic acid derivatives. In order
to elucidate the chiral recognition mechanism exerted by the new CSP, the
resolution of slightly differently modified derivatives of 2-hydroxycarboxylic
acids on the new CSP has been investigated. Based on the resolution results, a
chiral recognition mechanism utilizing three simultaneous interactions such as
the face to face pi-pi interaction and the two hydrogen bonding interactions
between the CSP and the more retained enantiomer of the analyte has been
proposed.
PMID- 10677078
TI - Determination of aliphatic anhydrides and acids by reversed-phase liquid
chromatography.
AB - Few chromatography methods have been reported for the determination of anhydrides
in mixtures or as mixed anhydrides. The potential reactivity of anhydrides with
water and other common eluent components complicates possible schemes for
separation and analysis. By optimizing variables that affect hydrolysis,
including the stationary phase, conditions can be found to successfully analyze
anhydrides as reactive as acetic anhydride. The corresponding acids can be
determined at the same time. The effect of the stationary phase on anhydride
hydrolysis rates may prove to be a sensitive means of probing stationary phase
chemistry.
PMID- 10677079
TI - Does further clean-up reduce the matrix enhancement effect in gas chromatographic
analysis of pesticide residues in food?
AB - Sample extracts of apples, peas, green beans, oranges, raspberries, clementines,
carrots, and wheat obtained using the Food and Drug Administration (acetone
extraction) and Canadian Pest Management Regulatory Agency (acetonitrile
extraction) multiresidue methods for pesticides were subjected to clean-up using
different solid-phase extraction (SPE) cartridges in an attempt to reduce or
eliminate the matrix enhancement effect. The matrix enhancement effect is related
to the blocking of active sites on the injector liner by matrix components,
thereby increasing signal in the presence of matrix versus standards in solvent
in which the pesticides themselves interact with the active sites. Graphitized
carbon black (GCB) was often used in combination with various anion-exchange SPE
cartridges. The extracts were then spiked with organophosphorus insecticides.
These process standards were then compared to standards in acetone of the same
concentration using gas chromatography with flame photometric detection or ion
trap mass spectrometric detection. Sample matrix enhancement varied from little
to no effect for some pesticides (e.g. chlorpyrifos, malathion) to >200% in the
case of certain susceptible pesticides. The GCB removed color components but
showed little effect in reducing matrix enhancement by itself. The anion-exchange
cartridges in combination with GCB or not, substantially reduced the matrix
enhancement effect but did not eliminate it.
PMID- 10677080
TI - Influence of pH*-value of methanolic electrolytes on electroosmotic flow in
hydrophilic coated capillaries.
AB - The dependency of EOF on the H+-concentration and the related so called pH* value
of methanolic electrolytes has been examined with poly(ethylene glycol) (PEG),
poly(vinyl alcohol) (PVA) and uncoated capillaries. These results were compared
with the pH dependency of EOF of these capillaries using aqueous buffers. In
uncoated capillaries the dependency of EOF on the pH(*)-value is very similar for
aqueous and methanolic electrolytes. The EOF increases with increasing H+
concentration and pH-hysteresis is observed. In PVA coated capillaries the EOF is
strongly reduced over wide pH* or pH ranges for both methanolic electrolytes and
aqueous buffers. The EOF in PEG coated capillaries is surprisingly directed to
the anode with methanolic electrolytes whereas a reduced cathodic EOF is observed
in aqueous electrolytes. The anodic EOF of PEG-coated capillaries in methanolic
electrolytes is independent of the pH*-value. The usefulness of PEG- and PVA
coated capillaries for adjusting the EOF in non-aqueous electrolytes for the
analysis of isomeric organic acids was demonstrated.
PMID- 10677081
TI - Extraction of iridoid glycosides and their determination by micellar
electrokinetic capillary chromatography.
AB - Several methods for the extraction of two iridoid glycosides, catalpol and
aucubin, from the plant matrix (Veronica longifolia leaves) were compared.
Pressurized hot water extraction and hot water extraction were the most efficient
isolation techniques for both. Pressurized liquid extraction and maceration with
various organic solvents were also tested. Relative to the amounts extracted with
hot water, ethanol extracted only 22% of catalpol and 25% of aucubin and
pressurized hot water extracted 83% of catalpol and 92% of aucubin. The lowest
relative standard deviations, 22% for catalpol and 8% for aucubin, were achieved
with hot water extraction (13 repetitions), and the highest relative standard
deviations, 76% for catalpol and 73% for aucubin, with pressurized liquid
extraction (five repetitions). A fast capillary electrophoretic method was
developed for the quantitative determination of catalpol and aucubin.
PMID- 10677082
TI - Protein adsorption to the bare silica wall in capillary electrophoresis
quantitative study on the chemical composition of the background electrolyte for
minimising the phenomenon.
AB - A novel method is reported for quantifying protein adsorption to naked silica
tubings and for assessing the efficacy of amino quenchers added to the background
electrolyte. It consists of flushing a fluorescently-labelled protein (myoglobin)
into a capillary equilibrated in Tris-acetate buffer, pH 5.0, until full
saturation of the potential adsorbing sites. Desorption is then affected by
driving electrophoretically sodium dodecyl sulphate (SDS) micelles into the
capillary from the cathodic reservoir: the peak of eluted material is quantified
fluorometrically by using a dual laser beam instrument able to read the
fluorescein-isothiocyanate-labelled myoglobin at 520 nm and the internal standard
(sulphorodamine) at 630 nm. As potential quenchers, a series of monoamines have
been investigated (triethylamine, triethanolamine, ethylamine), followed by
diamines (putrescine, cadaverine and hexamethonium bromide) and finally by
oligoamines [spermidine, spermine and TEPA (tetraethylenepentamine), i.e., a tri-
a tetra- and a pentamine, respectively]. Two values of molarities have been
derived: a value at 50% (a kind of a dissociation constant) and a value at 90%
inhibition of binding of macromolecules to the silica surface. According to these
figures of merit, mono- and diamines are rather poor quenchers of interaction
with the wall, since the 50% values are of the order of 50-100 mM and the 90%
values reach as high as 560 mM. On the contrary, oligoamines, especially spermine
and TEPA, are most effective, since the 50% molarities are in the sub-millimolar
range and the 90% values are of the order of ca. 1 mM. Figures of merit have also
been derived for different washing procedures. Those most commonly adopted in
routine practice, i.e., of washing with either 1 M NaOH or with 1 M HCl, or with
both, leave behind traces of proteins still bound to the wall, whereas the SDS
micelle electrophoretic desorption seems to be 100% effective.
PMID- 10677083
TI - Determination of diclofenac sodium by capillary zone electrophoresis with
electrochemical detection.
AB - Capillary zone electrophoresis was employed for the determination of diclofenac
sodium using an end-column amperometric detection with a carbon fiber
microelectrode, at a constant potential of 0.83 V vs. saturated calomel
electrode. The optimum conditions of separation and detection are 4.90 x 10(-3)
mol/l Na2HPO4-3.10 x 10(-3) mol/l NaH2PO4 (pH 7.0) for the buffer solution, 10 kV
for the separation voltage, 5 kV and 10 s for the injection voltage and the
injection time, respectively. The limit of detection is 2.5 x 10(-6) mol/l or 5.2
fmol (S/N=2). The relative standard deviation is 0.8% for the migration time and
4.7% for the electrophoretic peak current. The method was applied to the
determination of diclofenac sodium in human urine.
PMID- 10677084
TI - Use of high-performance liquid chromatographic fractionation of large RNA
molecules in the assay of group I intron ribozyme activity.
AB - Ion-pair reversed-phase high-performance liquid chromatography (HPLC), which has
previously been used to fractionate double-stranded DNA molecules, can be applied
to single-stranded RNA molecules in the size range of 200-1000 nucleotides. This
procedure permits RNA molecules to be separated and recovered rapidly in liquid
medium, thereby facilitating recovery. We have used this system to separate an in
vitro transcription product containing a group I intron ribozyme from the
intermediates and products of the splicing reaction, permitting rapid assay of
ribozyme activity without the use of radioactivity.
PMID- 10677085
TI - Determination of interfering triazine degradation products by gas chromatography
ion trap mass spectrometry.
AB - Deethylatrazine (DEA), an atrazine degradation product, has been added to the US
Environmental Protection Agency's Drinking Water Contaminant Candidate List
(CCL). In its gas chromatographic analysis, DEA can coelute with
deisopropylatrazine (DIA), another degradation product. The present work
demonstrates that the coelution of DEA and DIA can induce a significant (up to
approximately 50%) positive bias in the DEA determination, when using an ion-trap
mass spectrometer as the detector. The DIA determination is unaffected by the
coelution within experimental error. This may be explained in terms of gas-phase
ion fragment populations. A correction factor to the observed DEA concentration
may be developed based on the measured DIA concentration.
PMID- 10677086
TI - Apparatus and method for interfacing capillary electrophoresis and
chemiluminescence nitrogen detection for the analysis of nitrogen-containing
compounds.
AB - We have developed an interface that allows the specific detection of nitrogen
containing compounds by using a chemiluminescence nitrogen detector. The
feasibility of using this interface was demonstrated by separating and detecting
two nitrogen-containing compounds, p-aminosalicylic acid and L-phenylalanine.
Although baseline separation was achieved, the theoretical plates were lower when
compared to UV detection (25000 vs. approximately 85000). A sensitivity of 75 ng
(approximately 500 pmol) per injection was achieved with this system which is
adequate for pharmaceutical and biotech applications.
PMID- 10677087
TI - Determination of peroxides by capillary zone electrophoresis with amperometric
detection.
AB - The combination of cathodic amperometric detection with capillary zone
electrophoresis is demonstrated to be a versatile method for the quantification
of organic and inorganic peroxides. A gold microelectrode, polarized at -600 mV
against an Ag/AgCl reference electrode, is placed at the end of the capillary.
Since the electroosmotic flow purges the detector electrode from oxygen, no
degassing of the detector cell or the sample is necessary. With an injection
volume of ca. 1 nl, hydrogen peroxide, peroxosulfate, peroxy alkanoic acids and
the hydroperoxides of linoleic acid can be detected down to 10 micromol/l.
Separation of the isomeric hydroperoxides of the unsaturated fatty acids is
achieved by addition of beta-cyclodextrin to the electrolyte.
PMID- 10677088
TI - Ion exchange-based preconcentration for the determination of anions by capillary
electrophoresis.
AB - In the present paper a capillary zone electrophoresis (CZE)-compatible
preconcentration technique for anions, based on ion exchange, is described. The
described preconcentration approach has found limited use until recently because
of the inherent elution step that leads to contamination of the sample with
eluent components. In this paper, we describe an improved anion exchange-based
preconcentration technique in which contamination of the sample with the eluent
constituents, which occurs during anion elution from the preconcentration column,
is eliminated by on-line chemical suppression on a packed-bed suppressor column.
In the present communication, the basic principles of the proposed anion
enrichment system are presented. The system was optimized, resulting in a minimal
additional dilution of the eluted sample plug. This was achieved by the use of a
computer-controlled, sensing/switching system. The effectiveness of the developed
method was later tested on the determination of some anions in a synthetic sample
using CE apparatus.
PMID- 10677089
TI - Chromatographic analysis of bisphosphonates.
PMID- 10677090
TI - Low-dose methotrexate controls a severe form of polyarteritis nodosa.
PMID- 10677091
TI - "Strawberry" gingival hyperplasia: a pathognomonic mucocutaneous finding in
Wegener granulomatosis.
PMID- 10677092
TI - Serum levels of autoantibodies to BP180 correlate with disease activity in
patients with bullous pemphigoid.
AB - OBJECTIVE: To investigate the possible correlation of levels of circulating anti
BP180 autoantibodies with disease activity in bullous pemphigoid (BP). DESIGN:
Diagnostic study. SETTING: Regional referral center at a university dermatology
department. PATIENTS: Fifteen patients with typical clinical, histologic, and
immunofluorescence findings of BP who had not received prior systemic treatment.
INTERVENTIONS: Initially, 6 consecutive patients with BP were treated with oral
doxycycline and niacinamide. Subsequently, 9 consecutive patients with BP
received a combination of oral dapsone and prednisolone. MAIN OUTCOME MEASURES:
Disease activity, serum levels of autoantibodies to BP180, and titers of
antibasement membrane zone autoantibodies were assayed before initiation of
treatment and 4 and 8 weeks later. Reactivity to BP180 was analyzed by enzyme
linked immunosorbent assay using a recombinant form of BP180 NC16A. Titers of
anti-basement membrane zone autoantibodies were assayed by indirect
immunofluorescence on 1-mol/L sodium chloride-split human skin. RESULTS: In both
treatment groups, disease activity correlated with serum levels of autoantibodies
to BP180 NC16A (P = .004 [dapsone-prednisolone] and .007 [doxycycline
niacinamide]). No correlation was seen between disease activity and indirect
immunofluorescence reactivity (P = .18 and .16, respectively). In patients
receiving dapsone plus prednisolone, the dose of corticosteroids necessary to
suppress new blister formation correlated with anti-BP180 reactivity (P = .002).
CONCLUSIONS: In contrast to indirect immunofluorescence reactivity that reflects
reactivity to both BP 180 and BP230, serum levels of autoantibodies to BP180
correlate with disease activity in BP. Assaying reactivity to BP180 should be a
helpful guide for the therapeutic management of patients with this disease. Our
results underline the pathogenic relevance of autoantibodies to human BP180.
PMID- 10677093
TI - A randomized, 12-year primary-prevention trial of beta carotene supplementation
for nonmelanoma skin cancer in the physician's health study.
AB - CONTEXT: Although basic research provides plausible mechanisms for benefits of
beta carotene supplementation on nonmelanoma skin cancer (NMSC) primarily
consisting of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC),
observational studies are inconsistent. Randomized trial data are limited to 1
trial of secondary prevention that showed no effect of beta carotene on the
incidence of NMSC after 5 years. OBJECTIVE: To test whether supplementation with
beta carotene reduces the risk for development of a first NMSC, including BCC and
SCC. DESIGN: Randomized, double-blind, placebo-controlled trial with 12 years of
beta carotene supplementation and follow-up. SETTING: Physicians' Health Study in
the United States. PARTICIPANTS: Apparently healthy male physicians aged 40 to 84
years in 1982 (N = 22 071). INTERVENTION: Beta carotene, 50 mg, on alternate
days. MAIN OUTCOME MEASURE: Relative risk (RR) and 95% confidence interval (CI)
for a first NMSC, BCC, and SCC. RESULTS: After adjusting for age and randomized
aspirin assignment, there was no effect of beta carotene on the incidence of a
first NMSC (RR, 0.98; 95% CI, 0.92-1.05), BCC (RR, 0.99; 95% CI, 0.92-1.06), or
SCC (RR, 0.97; 95% CI, 0.84-1.13). There was also no significant evidence of
beneficial or harmful effects of beta carotene on NMSC by smoking status
(current, past, or never). CONCLUSION: This large-scale, randomized, primary
prevention trial among apparently healthy well-nourished men indicates that an
average of 12 years of supplementation with beta carotene does not affect the
development of a first NMSC, including BCC and SCC.
PMID- 10677094
TI - Decision support software to help primary care physicians triage skin cancer: a
pilot study.
AB - OBJECTIVE: To determine whether decision support software can help primary care
physicians proficiently triage lesions suggestive of basal cell and squamous cell
carcinoma. DESIGN/MEASURES: Physicians selected triage options for 15 digitized
images of skin lesions, with and without use of the decision support software.
PARTICIPANTS/SETTINGS: Twenty primary care physicians practicing in a health
maintenance organization or a city health clinic. INTERVENTION: Decision support
software designed to help physicians arrive at a triage recommendation consisted
of a clinical information form, a decision tree, and support features (teaching
points, example images, and diagrams). RESULTS: Without using the decision
support software, physicians chose the wrong triage decision 36.7% of the time;
using the decision support software, they chose the wrong response only 13.3% of
the time. Not using the decision support software, they failed to correctly
perform a biopsy on or refer patients with cancerous lesions 22.1% of the time;
using the software, they failed to correctly perform a biopsy on or refer
patients with cancerous lesions only 3.6% of the time. Physicians scored an
average of 3 points (of a possible 15 points) higher when they used the software
(signed rank, 101.0; P<.001). They scored an average of 1 point higher on the 7
cancerous lesions when they used the software (signed rank, 65.5; P<.001).
CONCLUSIONS: Use of decision support software could improve primary care
physicians' triage decisions for lesions suggestive of nonmelanoma skin cancer,
and potentially reduce morbidity and health care costs. We are designing a larger
study to evaluate the accuracy and utility of the software with patients seen in
clinical practice.
PMID- 10677095
TI - Expression of p53 in arsenic-related and sporadic basal cell carcinoma.
AB - BACKGROUND: The TP53 gene has been shown to have an important role in the genesis
of sporadic, presumably mainly sunlight-related, basal cell carcinoma (BCC).
However, its role in arsenic-related BCCs is not clear, although the trivalent
form of arsenic has been long recognized as a cause of BCC. Arsenic treatment has
been shown to cause hypermethylation of the TP53 gene in lung carcinoma cell
lines, but it is not known if this occurs in vivo in arsenic-related BCCs.
OBJECTIVE: To compare the immunohistochemical expression of the p53 protein in
arsenic-related and sporadic BCCs to determine if the expression pattern is
consistent with gene silencing. SETTING: A research institute and hospital in
Australia. CASES: One hundred seventeen white patients with 121 sporadic BCCs and
21 white patients with 92 arsenic-related BCCs. MAIN OUTCOME MEASURES: The
expression and the intensity of p53 were scored semiquantitatively. Statistical
analysis was performed using the chi2 test. RESULTS: Arsenic-related BCCs express
p53 less often and at a lower intensity than sporadic BCCs (P = .001; 2-tailed
test). The BCCs from sun-exposed sites, whether arsenic related or sporadic, more
frequently showed overexpression of p53 than those from less-exposed areas (P =
.004; 2-tailed test). The more aggressive subtypes of BCC show a higher level of
expression of p53 than the less aggressive forms (P = .04; 2-tailed chi2 test).
CONCLUSIONS: These results are consistent with the hypothesis that the TP53 gene
is down-regulated by methylation in arsenic-related BCC, particularly those from
less-exposed sites. However, an alternative possibility is that mutations in TP53
that stabilize the protein are less common in arsenic-related BCCs. Further
analysis will be necessary to distinguish between these hypotheses.
PMID- 10677096
TI - Melanoma screening: report of a survey in occupational medicine.
AB - BACKGROUND: Epidemiological studies concerning melanoma are most often performed
by general practitioners and dermatologists in patients previously aware of the
risk of nevi. OBJECTIVE: To determine the efficiency of early detection of
melanoma by occupational medicine specialists trained in the use of ABCDE
criteria during annual systematic examination of workers. METHODS: A total of 370
subjects with suspect lesions that demonstrated at least 2 of 5 ABCDE criteria
were selected from 65000 employees examined; these subjects were requested to see
their physician about possible excision. Of the 370 subjects, 273 (73.8%) were
seen at a second-year follow-up visit to determine their outcome. RESULTS: Among
the 273 subjects who were seen again, 172 (63.0%) had consulted a physician. For
the 101 subjects who had not seen a physician, the main reason was the negligence
(86.1%). A total of 353 atypical nevi were observed. The mean number of ABCDE
criteria noted per lesion was 2.6. Lesion diameter greater than 6 mm was the most
frequent (80.5%) and enlargement the least frequent criteria seen; heterochromous
coloration and diameter greater than 6 mm was the most common association
(54.5%). Five histologically confirmed melanomas were found among nevi excised in
78 subjects. CONCLUSION: This screening approach seems efficient for the early
detection of melanoma, demonstrating an incidence of 7.7 per 100000 vs. 9 per
100000 in the general French population.
PMID- 10677097
TI - Fibrosing alopecia in a pattern distribution: patterned lichen planopilaris or
androgenetic alopecia with a lichenoid tissue reaction pattern?
AB - BACKGROUND: Androgenetic alopecia is characterized by a defined area of
progressive nonscarring alopecia. The clinical and histological findings in 15
women and 4 men with progressive scarring alopecia in a pattern distribution were
studied. The results were evaluated and compared with clinicopathologic entities
that feature scarring of the central scalp area, specifically, lichen
planopilaris, pseudopelade, and follicular degeneration syndrome. OBSERVATIONS:
Patients developed progressive fibrosing alopecia of the central scalp, without
the multifocal areas of involvement typical of lichen planopilaris and
pseudopelade. Perifollicular erythema, follicular keratosis, and loss of
follicular orifices were limited to a patterned area of involvement. Biopsy
specimens of early lesions demonstrated hair follicle miniaturization and a
lichenoid inflammatory infiltrate targeting the upper follicle region. Advanced
lesions showed perifollicular lamellar fibrosis and completely fibrosed
follicular tracts indistinguishable from end-stage lichen planopilaris,
pseudopelade, or follicular degeneration syndrome. CONCLUSIONS: Some patients
with androgenetic alopecia might have additional clinical and histological
features of inflammation and fibrosis limited to the area of androgenetic hair
loss. In these patients, the histological findings of early lesions are identical
to those seen in lichen planopilaris. The lichenoid tissue reaction leading to
follicular destruction in these patients might be pathogenetically related to the
events underlying androgenetic alopecia.
PMID- 10677098
TI - Clinical findings in mosaic carriers of hypohidrotic ectodermal dysplasia.
AB - BACKGROUND: Hypohidrotic ectodermal dysplasia (HED) is a severe developmental
disorder in which nonallelic genetic heterogeneity has been demonstrated. Even
though X-linked and autosomal recessive forms are phenotypically similar,
identification of the way of transmission is mandatory to give reliable genetic
counseling to the family and to address molecular studies. Complete examination
of relatives of patients with HED and identification of carriers of partial forms
of the disorder in their families is the key to clarifying intrafamilial genetic
transmission. OBSERVATIONS: Seven patients diagnosed as having HED and their
first-degree relatives were carefully examined and tested with starch-iodine.
Useful signs for identifying possible carriers of and postzygotic mosaics for X
linked HED and for finding distinctive features between the X-linked and the
autosomal recessive forms of the disorder were recorded. Of these, the most
striking finding was the clinical evidence of the distribution of normal and
abnormal skin along Blaschko lines in heterozygous and postzygotic mutation
carriers of X-linked HED. Six heterozygous female carriers of X-linked HED, 2
males with postzygotic mutations for X-linked HED, and 1 female with autosomal
recessive HED were clinically identified. At the end, 6 families had a diagnosis
of X-linked HED, while 1 had a diagnosis ofautosomal recessive HED. Clinical
data, family history, and starch-iodine test results were never in conflict in
the 7 families. CONCLUSIONS: Careful clinical examination is the best way to
detect heterozygous carriers and postzygotic mutation of X-linked HED.
Heterozygous parents of patients with autosomal recessive HED show no features of
the disorder. The starch-iodine test is not superior to a clinical examination in
heterozygous carrier detection but may play a confirmative role and be of help in
differentiating X-linked and autosomal recessive HED in isolated patients.
PMID- 10677099
TI - Inflammatory variant of epidermolysis bullosa acquisita with IgG autoantibodies
against type VII collagen and laminin alpha3.
AB - BACKGROUND: The inflammatory variant of epidermolysis bullosa acquisita (EBA) may
clinically closely resemble bullous or cicatricial pemphigoid. Patients with
inflammatory EBA have IgG autoantibodies against type VII collagen. Patients with
anti-epiligrin cicatricial pemphigoid have IgG autoantibodies against laminin 5.
OBSERVATION: We describe a patient with inflammatory EBA exhibiting nonscarring
oral and vaginal involvement. Indirect immunofluorescence using skin substrate
lacking an epidermal basement membrane molecule, direct immunoelectron
microscopy, immunoblot, and immunoprecipitation studies revealed the simultaneous
presence of circulating IgG autoantibodies against type VII collagen and laminin
alpha3. A final diagnosis of EBA was based on the sublamina densa level of
blister formation. CONCLUSION: This case illustrates the clinical and
immunological overlap between EBA and anti-epiligrin cicatricial pemphigoid, a
unique finding that may have developed as a consequence of epitope spreading.
PMID- 10677100
TI - A new look at scarring alopecia.
PMID- 10677101
TI - Prevention of nonmelanoma skin cancer.
PMID- 10677102
TI - Decision support is changing health care.
PMID- 10677103
TI - Levels of antibodies to BP180 correlate with disease activity in bullous
pemphigoid.
PMID- 10677104
TI - Recalcitrant patch of alopecia on the scalp.
PMID- 10677105
TI - Acquired nodule on the right side of the nose.
PMID- 10677106
TI - Truncal hypopigmented macules and facial hyperpigmented papules.
PMID- 10677107
TI - Penile necrosis.
PMID- 10677108
TI - "Significant" scientific productivity should be weighed against the expenses
necessary to finance it.
PMID- 10677109
TI - Use caution when establishing "routine" prophylactic antibiotic procedures.
PMID- 10677110
TI - The ethical issues of the Holmesburg studies have been addressed.
PMID- 10677111
TI - Ethical accusations: the loss of common sense.
PMID- 10677112
TI - Scarring following Q-switched laser treatment of "double tattoos".
PMID- 10677113
TI - Blood transfusions and psoriasis: is there a link?
PMID- 10677114
TI - Systemic photodynamic therapy is a safe and effective treatment for psoriasis.
PMID- 10677115
TI - North American Contact Dermatitis Group patch-test results, 1996-1998.
PMID- 10677116
TI - The prevalence and incidence of atopic dermatitis in a birth cohort: the
importance of a family history of atopy.
PMID- 10677117
TI - Acrosclerosis in patients with systemic sclerosis responds to low-dose UV-A1
phototherapy.
PMID- 10677118
TI - Blood screening--the next generation in testing.
PMID- 10677119
TI - Use of cytokeratin fragments 19.1 and 19.21 (Cyfra 21-1) in the differentiation
of malignant and benign pleural effusions.
AB - BACKGROUND: Differentiation between malignant and benign pleural effusions is
often difficult. Serum level of Cyfra 21-1, a marker of cytokeratin 19 fragments,
has been used in the diagnosis and monitoring of epithelial tumours, especially
bronchogenic carcinomas. AIM: This study is designed to establish the usefulness
of effusion Cyfra 21-1 level in differentiating malignant from benign effusions.
METHODS: Forty-eight malignant effusion aspirates (proven by cytology or pleural
biopsy) and 34 benign samples were compared. Cyfra 21-1 concentration was
measured by a solid phase sandwich radioimmunoassay (Centocur, USA). RESULTS:
Cyfra 21-1 level was significantly higher in malignant effusions (geometric mean
123.6 ng/mL, 95% confidence interval [CI] 76.6-199.4) than in benign ones
(geometric mean 14.3 ng/mL, 95% CI 8.5-23.9), p<0.00005. By Receiver Operating
Characteristics curve analysis, the sensitivity is 77% for a specificity of 79%
if the cut-off is set at 32 ng/mL. No significant difference was observed (p=0.1)
in Cyfra 21-1 concentration between adenocarcinoma and mesothelioma effusions.
Cyfra 21-1 level was not influenced by the effusion protein concentration
(r=0.29), or by renal function as measured by serum creatinine (r=0.1). There was
no significant difference between Cyfra 21-1 levels in benign exudate and
transudate effusions, p=0.28. CONCLUSIONS: Cyfra 21-1 is a useful adjunct in the
workup of effusions but should not replace conventional investigations as there
is considerable overlap in levels between benign and malignant groups. It is
unable to differentiate between subgroups of malignancies.
PMID- 10677120
TI - Renal sarcoidosis in Christchurch, New Zealand 1970-1998.
AB - AIM: To identify patients presenting to a nephrologist in whom a diagnosis of
sarcoidosis could be made, to assess the relevant causes of renal involvement and
to review treatment and long-term follow-up of this group. METHOD: A
retrospective review of the computer database PROTON for patients given the
diagnosis of sarcoidosis, followed by a case note review of identified patients
with respect to the mode of presentation, clinical and laboratory features,
treatment and subsequent follow-up. RESULTS: Nineteen patients (15 males) were
identified, mean age 45 years, all were Caucasian, and follow-up was four months
to 26 years (mean 9.3 years). Most common mode of presentation was acute renal
failure (11) during spring/summer (14). Evidence for systemic disease was present
in all patients. Mean plasma creatinine on presentation was 0.52 mmol/L and
calcium 3.01 mmol/L. Hypercalcaemia was present in 60%. Kidney biopsy was
performed in seven patients with the predominant findings of tubular atrophy and
interstitial fibrosis; significant granulomata were present in only two.
Treatment in all patients was with corticosteroids with good result. Mean long
term plasma creatinine was 0.17 mmol/L at 9.3 years. Steroid withdrawal was
attempted in all patients, successful in five, with the mean time to relapse of
five months in the remaining 14. Mean steroid dose in this group was 7.6 mg on
long term follow-up. CONCLUSIONS: Sarcoidosis causes renal dysfunction mainly
through altered calcium metabolism. Treatment with corticosteroids is successful
in improving renal function, but relapse is common on steroid withdrawal and
prolonged treatment is necessary for disease control.
PMID- 10677121
TI - Severity of liver disease in hepatitis C infection contracted through injecting
drug use.
AB - BACKGROUND: Injecting drug use (IDU) is currently the most common route of
hepatitis C virus (HCV) transmission in Australia and many other Western
countries. Most reports on the natural history of HCV have examined populations
that included patients from all risk groups, but it is possible that this
increasingly important subgroup is different. AIMS: To assess the severity of
liver disease in individuals who acquired HCV through IDU. METHODS: Three hundred
and forty-six patients with confirmed HCV infection and a history of IDU, who had
had a liver biopsy performed were recruited from a liver clinic. Demographic
data, liver function tests and hepatitis B serology were obtained on all
patients. A detailed drug use history and HCV viral studies were also available
in a subgroup of 142 patients. RESULTS: Mean age of the group was 34 years and
73% were male. Mean duration of HCV infection was 14.6 years. Forty one per cent
were infected with genotype 3a, 19% - 1a, 17% - 1 (nonsubtypable), 14% - 1b and
4% - 2b. Cirrhosis was present in 12% of patients. Patients with cirrhosis (38
years) were older than those with chronic hepatitis (34 years; p=0.0003) and had
a longer duration of infection (17.2 vs 14.3 years; p=0.003). On multivariate
analysis, however, patient age was the only factor independently associated with
cirrhosis (odds ratio 4.2; 95% confidence interval 1.4-12.6). CONCLUSION: While
cirrhosis is less common in this group than in other HCV infected populations,
its prevalence may increase as these patients are followed over a longer period
of time.
PMID- 10677122
TI - Cardiac surgery in octogenarians--The Green Lane Hospital Experience 1995-1998.
AB - BACKGROUND: An increasing number of patients aged 80 years and over are being
considered and accepted for cardiac surgery. AIM: To review the experience of
surgery in this elderly group of patients at our institution. METHODS: Hospital
records of octogenarians undergoing surgery between January 1995 and September
1998 were reviewed and follow-up was obtained by general practitioner (GP) and
patient questionnaires. RESULTS: Thirty-seven patients underwent cardiac surgery.
The mean age was 82.8+/-1.4 years (range 80.8 to 86.2 years). Twenty-three (62%)
were male. All were independent pre-operatively with severe symptoms and minor co
existing morbidity. All operations were urgent except two (emergency). Twenty
patients (54%) had isolated coronary surgery, six (16%) aortic valve replacement
alone, and 11 (30%) combined surgery. There were four (11%) early deaths and five
(14%) peri-operative neurological events. The mean duration of post-operative
intensive care stay was 2.4+/-3.9 days (range 0.05 to 16, median 1.0) and post
operative hospital stay 14.0+/-13.9 days (range 0 to 79, median 11). At the time
of follow-up (mean duration 20.0+/-11.2 months) two further patients had died
(non-cardiac). Twenty-six of the 31 survivors were living at home (23
independently), one with relatives, and four in residential care. Their cardiac
symptoms were well controlled. The GPs of all hospital survivors, and all
surviving patients themselves, felt that cardiac surgery had been beneficial.
CONCLUSIONS: Cardiac surgery in the very elderly has been reserved for those with
severe disease or symptoms and little co-morbidity. Early mortality is higher
than for the general population undergoing cardiac surgery, but post-operative
resource use is acceptable and the intermediate-term outcome for survivors is
good.
PMID- 10677123
TI - Evaluation of antibodies to beta2-glycoprotein 1 in the causation of coronary
atherosclerosis as part of the antiphospholipid syndrome.
AB - BACKGROUND: Anticardiolipin antibodies (aCL) are associated with accelerated
coronary atherosclerosis. Beta2-glycoprotein 1 is a cofactor necessary for the
binding of aCL. AIM: The aim of this study was to determine whether antibodies to
beta2-glycoprotein 1 (anti-beta2GP1) predispose to coronary artery disease (CAD),
and whether the measurement of anti-beta2GP1 will be more useful than aCL alone
in the evaluation of coronary risk. METHODS: Persons who had undergone coronary
angiography were invited to participate, and risk factors for coronary
atherosclerosis recorded. IgG aCL and anti-beta2GP1 were measured and fasting
triglyceride (TG) and total cholesterol (TC) levels were determined. Angiographic
score (AS) was defined as the number of diseased vessels (0, 1, 2, 3), (>50%
stenosis). Ethics Committee approval was obtained. Statistical comparison used
the Student's t test and Chi-squared test. RESULTS: Ninety-seven subjects (63
male) with age range 38-81 years (mean 66.0) participated. There were 31 subjects
with AS=0, 27 with AS=1, 22 with AS=2, and 17 with AS=3. The three subjects with
positive aCL all had CAD, as did three of the four subjects with positive anti
beta2GP1. Among patients with CAD, there was an equal incidence (4.5%, three/66)
of aCL and anti-beta2GP1, and an incidence of either aCL or anti-beta2GP1 of 7.6%
(five/66). Compared to the group with AS=0, those with AS=1, 2 or 3 comprised a
higher mean age (p=0.001) however, there was no significant difference in the
prevalence of other coronary risk factors between the two groups. There was no
difference in the proportions of patients with either aCL or anti-beta2GP1 in the
group with AS=1, 2, or 3, compared to the group with AS=0 (5/66 c.f. 1/31,
chi2=0.146, p>0.5). CONCLUSIONS: Our study has not supported an association
between anti-beta2GP1 and CAD. The measurement of anti-beta2GP1 (or aCL) in the
investigation of premature CAD is not justified on the basis of our results.
PMID- 10677124
TI - The effect of parental smoking on presence of wheez or airway hyper
responsiveness in New South Wales school children.
AB - BACKGROUND AND AIMS: To assess accurately the effect of parental smoking on the
respiratory health of New South Wales (NSW) school children, we obtained a large
data set by pooling data from seven cross-sectional studies conducted in NSW
between 1991 and 1993. METHODS: A random sample of 6394 children age eight to 11
years was studied. Respiratory symptoms, family history of asthma and parental
smoking history were measured by questionnaire, atopy by skin prick test and
airway hyper-responsiveness (AHR) by histamine inhalation test. RESULTS: In
total, 58.3% of children had at least one parent who smoked; 38.5% were exposed
to maternal smoking. After adjusting for potential confounders, such as atopy,
parental history of asthma and bronchitis in the first two years, children who
were exposed to maternal smoking had a significantly increased risk of recent
wheeze but not of AHR (odds ratios 1.33; 95% CI: 1.2-1.5 and 1.00; 95% CI: 0.9
1.2). CONCLUSIONS: The positive association with wheeze and the lack of an
association with AHR suggests that exposure to parental smoking leads to
wheezing, but does not increase airway responsiveness.
PMID- 10677125
TI - New treatments for multiple sclerosis.
PMID- 10677126
TI - Bedside pacetermination of arrhythmias using an explanted automatic
defibrillator.
PMID- 10677127
TI - Systematic reviews and geriatric interventions--the need for scientific
methodology.
PMID- 10677128
TI - Medicine at the beginning of the 21st century: a personal viewpoint--a
peripatetic overview.
PMID- 10677129
TI - Extracranial vertebral artery dissection presenting as neurogenic pulmonary
oedema.
PMID- 10677130
TI - Asp or spa (snakebite or drowning)?
PMID- 10677131
TI - Oestrogen and vascular disease.
PMID- 10677132
TI - Adult onset restricted fish allergy.
PMID- 10677133
TI - Gemcitabine and the blood brain barrier.
PMID- 10677134
TI - Multiple organ failure related to pantoprazole.
PMID- 10677135
TI - Irukandji-like syndrome in Victoria.
PMID- 10677136
TI - Faecal occult blood test screening for colorectal cancer.
PMID- 10677137
TI - Trepopnoea due to positional narrowing of the left main bronchus.
PMID- 10677138
TI - Surgical palliation of carcinoid syndrome.
PMID- 10677139
TI - Post obstructive pneumonia secondary to endobronchial tuberculosis--an
institutional review.
PMID- 10677140
TI - Pulmonary and meningeal cryptococcosis in pulmonary alveolar proteinosis.
PMID- 10677141
TI - Health complaints related to pesticide stored at a public health clinic.
AB - Employees at a health center in Georgia were concerned that symptoms experienced
by some employees were related to pesticide exposure at the center. Malathion and
DDT, used for mosquito control from 1969 to 1981, had been stored and handled at
the center's first floor. We surveyed 117 (91%) of 129 employees to determine
whether reported symptoms were associated with pesticide exposure. We performed
environmental sampling for pesticides. We analyzed serum samples for 17
chlorinated pesticides, and urine samples for malathion. We found that 37% of the
participants had reported a diagnosis of sinusitis and 24% of bronchitis since
working at the health center. Frequently reported symptoms were eye irritation
(44%) and headache (68%). DDT and malathion were found at levels of 2.4 and 11%,
respectively, in bulk samples from the loading dock of the building. Multivariate
analysis of responses to the questionnaire showed that the perception of odors,
inadequate air flow, and length of employment were significantly associated with
the employees' health complaints. Pesticide concentrations in employees' serum
and urine samples were not associated with any health complaint. The health
complaints reported by the employees at the health center were precipitated by
both environmental and psychological factors. The epidemiology and laboratory
components of this study highlight the importance of obtaining biological
measurements in episodes of perceived environmental exposure.
PMID- 10677142
TI - Effects of taurine on ozone-induced memory deficits and lipid peroxidation levels
in brains of young, mature, and old rats.
AB - To determine the antioxidant effects of taurine on changes in memory and lipid
peroxidation levels in brain caused by exposure to ozone, we carried out two
experiments. In the first experiment, 150 rats were separated into three
experimental blocks (young, mature, and old) with five groups each and received
one of the following treatments: control, taurine, ozone, taurine before ozone,
and taurine after ozone. Ozone exposure was 0.7-0.8 ppm for 4 h and taurine was
administered ip at 43 mg/kg, after or before ozone exposure. Subsequently, rats
were tested in passive avoidance conditioning. In the second experiment, samples
from frontal cortex, hippocampus, striatum, and cerebellum were obtained from 60
rats (young and old), using the same treatments with 1 ppm ozone. Results show
both an impairment in short-term and long-term memory with ozone and an
improvement with taurine after ozone exposure, depending on age. In contrast to
young rats, old rats showed peroxidation in all control groups and an improvement
in memory with taurine. When taurine was applied before ozone, we found high
peroxidation levels in the frontal cortex of old rats and the hippocampus of
young rats; in the striatum, peroxidation caused by ozone was blocked when
taurine was applied either before or after ozone exposure.
PMID- 10677143
TI - Effects of Great Lakes fish consumption on brain PCB pattern, concentration, and
progressive-ratio performance.
AB - This study investigated the effects of consumption of Great Lakes fish on
progressive ratio performance, and on the pattern and concentrations of brain
polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethene (DDE), and mirex
in the rat. Adult, male Sprague-Dawley rats were fed a 30% diet of either Lake
Ontario salmon (LAKE), Pacific Ocean salmon, or lab chow control for 20 or 65
days. Following the treatment regimen, half the rats from each group were
sacrificed immediately for gas chromatographic analysis of organochlorine
contaminants, and the other half were tested on a multiple fixed-ratio
progressive-ratio reinforcement schedule and then sacrificed for analysis.
Consumption of Lake Ontario fish resulted in significantly higher levels of brain
PCBs, DDE, and mirex relative to controls, but still well within human exposure
ranges (<1 microg/g fat). Consumption of Lake Ontario fish for 20 or 65 days
produced an average brain PCB concentration of 457 and 934 ng/g fat,
respectively. Consumption of laboratory rat chow or Pacific Ocean salmon for 20
or 65 days produced an average brain PCB concentration of 240, 464, and 441 ng/g
fat, respectively. Moreover, both LAKE-fed groups showed a much more heavily
chlorinated pattern of brain PCBs than all control groups, as evidenced by both
significant increases in the most heavily chlorinated PCB congeners and
significant increases in the average chlorine biphenyl. All LAKE brains contained
significant concentrations of DDE and mirex, whereas no control brains contained
any detectable quantities. Analysis of progressive-ratio performance indicated
that LAKE rats responded normally during fixed-ratio schedules but quit
significantly sooner than control rats on a progressive-ratio 5 (PR5) schedule,
indicating reduced persistence on progressively leaner reinforcement schedules.
Analysis of brain PCBs indicated that total PCBs were most strongly related to
PR5 performance. These data indicate that consumption by rats of contaminated
Lake Ontario fish produces (1) increased concentrations of PCBs, DDE, and mirex
in the brain, (2) a more heavily chlorinated distribution of PCBs in the brain,
and (3) reduced persistence of progressive-ratio reinforcement schedules. While
these behavioral changes are related to brain PCB level, more work is necessary
before the effects can be directly attributed to PCBs.
PMID- 10677144
TI - Spatially resolved hazard and exposure assessments: an example of lead in soil at
Lavrion, Greece.
AB - Spatially resolved hazard assessment (SRHA) and spatially resolved exposure
assessment (SREA) are methodologies that have been devised for assessing child
exposure to soil containing environmental pollutants. These are based on either a
quantitative or a semiquantitative approach. The feasibility of the methodologies
has been demonstrated in a study assessing child exposure to Pb accessible in
soil at the town of Lavrion in Greece. Using a quantitative approach, both
measured and kriged concentrations of Pb in soil are compared with an
"established" statutory threshold value. The probabilistic approach gives a
refined classification of the contaminated land, since it takes into
consideration the uncertainty in both the actual measurement and estimated kriged
values. Two exposure assessment models (i.e., IEUBK and HESP) are used as the
basis of the quantitative SREA methodologies. The significant correlation between
the blood-Pb predictions, using the IEUBK model, and measured concentrations
provides a partial validation of the method, because it allows for the
uncertainty in the measurements and the lack of some site-specific measurements.
The semiquantitative applications of SRHA and SREA incorporate both qualitative
information (e.g., land use and dustiness of waste) and quantitative information
(e.g., distance from wastes and distance from industry). The significant
correlation between the results of these assessments and the measured blood-Pb
levels confirms the robust nature of this approach. Successful application of
these methodologies could reduce the cost of the assessment and allow areas to be
prioritized for further investigation, remediation, or risk management.
PMID- 10677145
TI - Determination of spatial continuity of soil lead levels in an urban residential
neighborhood.
AB - This study uses geostatistical techniques to model and estimate soil lead levels
in an urban, residential neighborhood. Sixty-two composite soil samples (median
1773 ppm; range 175 to 7953 ppm) in a four-block area of brick and stone homes
were obtained. The spatial continuity of soil lead levels was modeled with a semi
variogram, which was then used to estimate lead levels at unsampled locations, a
process called kriging. Because soil lead levels were spatially correlated, it is
likely that a "nonrandom" process generated the lead distribution found. This
finding signifies the existence of lead sources which were tentatively identified
on historical maps of the area and from past traffic volume patterns. The
distribution of kriged estimates of soil lead levels provides an explanatory tool
for exploring and identifying potential sources and may be useful for targeting
urban soil abatement efforts.
PMID- 10677146
TI - Cadmium levels in kidney cortex in Swedish farmers.
AB - The cadmium levels in kidney cortex (K-Cd) did not differ statistically between
10 nonsmoking farmers from the south of Sweden, who had a high intake of locally
produced food and who were affected by acid precipitation (as indicated by low pH
in the drinking water from their private wells) and 10 farmers less affected
(medians: K-Cd, 18 vs. 14 microg/g; water pH, 5.2 vs. 7.8). Neither did 10
farmers selected because of "high" blood cadmium (B-Cd) differ from 10 with "low"
[medians: K-Cd, 15 vs. 9 microg/g; B-Cd, 2.6 vs. 1.3 nmol/L (0.29 vs. 0.14
microg/L)]. In all 40 farmers, there was an increase of urinary cadmium levels (U
Cd) with decreasing drinking water pH (r(s) = -0.32, P = 0.045). Further, K-Cd
increased with rising B-Cd (r(s) = 0.33, P = 0.037), and both B-Cd (r(s) = 0.73,
P = 0.0005), and U-Cd (r(s) = 0.74, P = 0.0005) rose with increasing age.
Further, there was an association between U-Cd and B-Cd (r(s) = 0.68, P =
0.0005). We could not demonstrate with certainty any effect of the acid
precipitation on the cadmium retention in the farmers, although the association
between U-Cd and drinking water pH deserves further study.
PMID- 10677147
TI - Acquisition and retention of lead by young children.
AB - The concentrations and isotope ratios of lead in blood and urine, on the hands,
and in duplicate diet samples were measured for children living in Omaha,
Nebraska. One group consisted of 22 children followed from birth to between 1 and
2 years of age and another group was 20 2- to 4-year-old children followed for 1
year, although some in each group were followed for periods between 3 and 4
years. At no time in life was a component of dietary lead identified in blood by
isotope ratios, and blood lead appears dominated by lead derived from the hands,
which in turn appears derived from the floors. For some homes floor lead appeared
to be a mixture of lead from window sills and from the exterior. Only 2 of the
children appear to have ingested lead directly from window sills. Several who
lived in homes being remodeled were exposed to lead before the age of 2 years.
For those who had been briefly exposed during professional remodeling the blood
lead fell with a half-life of 10 months but for those who had suffered prolonged
exposure during remodeling by parents the apparent half-life was longer, between
20 and 38 months.
PMID- 10677149
TI - Re: evaluating mercury exposure through fish consumption in the Amazon--the roles
of biomarkers and predictive models.
PMID- 10677148
TI - Maternal bone lead contribution to blood lead during and after pregnancy.
AB - We examined bone lead contribution to blood lead in a group of 311 immigrant
women, 99% from Latin America, during the third trimester of pregnancy and 1 to 2
months after delivery. We measured in vivo tibia and calcaneus (heel) bone lead
concentration in the postdelivery period with K shell X-ray fluorescence.
Prenatal and postnatal geometric mean (range) blood lead level was 2.2 microg/dL
(0.4 to 38.7) and 2.8 microg/dL (0.4 to 25.4), reflecting low current exposure.
Postnatal blood lead level was significantly higher than prenatal (P<0.0001).
Mean (range) tibia and calcaneus lead concentration was 6.7 microg/g (-33.7 to
62.2) and 8.4 microg/g (- 30.1 to 66.4), reflecting varying but elevated past
lead exposure. Mean calcaneus lead concentration was significantly higher than
mean tibia lead concentration (P = 0.055). Variance-weighted multiple regression
and structural equation models showed that both calcaneus and tibia lead were
directly associated with prenatal blood lead but only calcaneus lead was
associated with postnatal blood lead. Increasing natural log years in the United
States independently predicted decreasing calcaneus and third-trimester blood
lead. The data suggest that while some exogenous lead sources and modulators of
blood lead level, such as use of lead-glazed pottery and calcium in the diet,
control lead exposure during and after pregnancy, endogenous lead sources from
past exposure before immigration continue to influence blood lead levels in this
sample.
PMID- 10677151
TI - Tissue engineered artificial skin composed of dermis and epidermis.
AB - We made an artificial skin comprised of a stratified layer of keratinocytes and a
dermal matrix with a type I collagen containing fibroblasts. In this work, we
showed keratinocyte behavior under primary culture, gel contractions varying with
concentration of collagen solution, and cell growth plots in the collagen gel.
The optimum behavior of dermal equivalent could be obtained using 3.0 mg/ml
collagen solution and attached gel culture. The attached gel culture had a
jumping effect of growth factor on cell growth at the lag phase. To develop the
artificial skin, 1x10(5) cells/cm2 of keratinocytes were cultured on the dermal
equivalent at air-liquid interface. Finally, to overcome the problem that
artificial skin of collagen gel was torn easily during suturing of grafting, we
prepared histocompatible collagen mesh and attached the mesh to the bottom of the
gel. Cultured artificial skins were successfully grafted onto rats.
PMID- 10677150
TI - Influence of different hemodialysis membranes on red blood cell susceptibility to
oxidative stress.
AB - Oxidative stress is crucial in red blood cell (RBC) damage induced by activated
neutrophils in in vitro experiments. The aim of the study was to evaluate whether
the bioincompatibility phenomena occurring during hemodialysis (HD) (where
neutrophil activation with increased free radical production is well documented)
may have detrimental effects on RBC. We evaluated RBC susceptibility to oxidative
stress before and after HD in 15 patients using Cuprophan, cellulose triacetate,
and polysulfone membrane. RBC were incubated with t-butyl hydroperoxide as an
oxidizing agent both in the presence and in the absence of the catalase inhibitor
sodium azide. The level of malonaldehyde (MDA), a product of lipid peroxidation,
was measured at 0, 5, 10, 15, and 30 min of incubation. When Cuprophan membrane
was used, the MDA production was significantly higher after HD, indicating an
increased susceptibility to oxidative stress in comparison to pre-HD. The
addition of sodium azide enhanced this phenomenon. Both cellulose triacetate and
polysulfone membranes did not significantly influence RBC susceptibility to
oxidative stress. Neither the level of RBC reduced glutathione nor the RBC
glutathione redox ratio changed significantly during HD with any of the membranes
used. The RBC susceptibility to oxidative stress was influenced in different ways
according to the dialysis membrane used, being increased only when using the more
bioincompatible membrane Cuprophan, where neutrophil activation with increased
free radical production is well documented. The alterations found in this study
might contribute to the reduced RBC longevity of HD patients where a
bioincompatible membrane is used.
PMID- 10677152
TI - Immobilization of ligand-modified polyamidoamine dendrimer for cultivation of
hepatoma cells.
AB - Cationic polyamidoamine dendrimers are known to be highly branched cascade
polymers. The core part of these polymers, tris(2-aminoethyl)amine, was
immobilized onto polystyrene plates to which animal cells do not adhere. using
photoreactive 4-(3-trifluoromethylazirino) benzoyl-N-succinimide (TDBA-OSu).
Cells of a rat hepatoma cell line, H4-II-E-C3, adhered to a surface immobilized
with a first-generation dendrimer probably through interactions between the
terminal amino groups of the dendrimer and the cell membranes. The adhered cells
were viable, could proliferate, and exhibited urea synthetic activity. The
modification of the terminal amino groups with fructose increased the final
number of cells obtained after 5 days of cultivation. Multigeneration dendrimers
were prepared by repeated linkage of tris(2-aminoethyl)amine with the amino
groups. Theoretically, the number of terminal amino groups available for ligand
modification is twice as much for each generation of dendrimer growth. Cells
cultivated on multigeneration fructose-modified dendrimers exhibited enhanced
urea synthetic activity. The use of ligand-modified dendrimers is, therefore,
considered to be very promising for the construction of bioartificial organs
based on cultivation of the animal cells.
PMID- 10677153
TI - Small diameter vascular prosthesis with a nonthrombogenic phospholipid polymer
surface: preliminary study of a new concept for functioning in the absence of
pseudo- or neointima formation.
AB - The purpose of this study was to prepare a small diameter vascular prosthesis
functioning without pseudointima formation. A nonthrombogenic phospholipid
polymer, the 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, has a cell
membrane-like structure and has demonstrated strong nonthrombogenicity. We have
recently prepared 2 kinds of vascular prostheses, 2 mm in diameter, composed of
the MPC polymer and segmented polyurethane (SPU). One includes 7.5 wt% MPC
polymer (SPU/MPC[7.5] prosthesis), and the other includes 10.0 wt% (SPU/MPC[10]
prosthesis). These prostheses were placed in rabbit carotid arteries and were
retrieved at 1 and 4 weeks after implantation. A pseudointima was observed at 4
weeks on the SPU/MPC(7.5). For the SPU/MPC(10), the surface was macroscopically
clear without a pseudointima even after a 4 week implantation. It appears that
the SPU/MPC(10) prosthesis, functioning without a pseudointima, possesses a
stronger nonthrombogenicity and would be more applicable for clinical use.
PMID- 10677154
TI - Modeling flow effects on thrombotic deposition in a membrane oxygenator.
AB - The hypothesis that regions of low blood velocity in a membrane oxygenator, as
predicted by computational fluid dynamics (CFD), would correspond with regions of
clinical thrombotic deposition was investigated. Twenty heparin-coated
oxygenators were sectioned following use in adult extracorporeal membrane
oxygenation. The activated clotting time (ACT) was maintained at approximately
180 s via heparin infusion throughout the support period. Cross-sections were
systematically photographed, and slides made to allow image projection upon a
digitizing pad. Thrombotic deposition was traced to allow creation of a device
cross-section image with an overlaid color scale representing thrombotic
deposition frequency. A two-dimensional CFD model was developed to predict blood
velocities throughout the oxygenator cross-section. Direct spatial comparisons
were made between maps of CFD modeled blood speed and thrombotic deposition.
Theoretical oxygenator design modification was performed within the CFD model to
investigate flow paths which might minimize regions of low blood velocity. CFD
results demonstrated that low velocity regions qualitatively matched regions with
a high incidence of thrombotic deposition. Thrombotic deposition was also
correlated to longer perfusion periods. This technique of coupling clinical data
and CFD offers the potential to relate flow characteristics to thrombotic
deposition and represents a potentially powerful new methodology for the
optimization of oxygenator flow-related biocompatibility.
PMID- 10677155
TI - Enhanced responsiveness of circulatory neutrophils after cardiopulmonary bypass:
increased aggregability and superoxide producing capacity.
AB - Cardiac surgery with cardiopulmonary bypass (CPB) induces a whole body
inflammatory response that sometimes leads to postoperative organ dysfunction,
and neutrophil activation plays an important role in this reaction. Neutrophil
priming has been described as a change in neutrophil status such that neutrophils
show enhanced responsiveness to a second activating stimulus. We hypothesized
that neutrophil priming occurs by cardiac surgery with CPB and is temporally
related to the neutrophilia after surgery. To evaluate primed circulatory
neutrophil status, we measured aggregation activity stimulated by N-formyl-methyl
leucyl-phenyl-alanine (FMLP) and free radical producing activity by tumor
necrosing factor (TNF) alpha in peripheral blood samples. Eleven adult patients
undergoing elective cardiac surgery with CPB were studied. Blood samples were
taken before surgery, at the end of bypass, 12 h after surgery, and 7 days after
surgery. Aggregation activity and superoxide generation were significantly
elevated 12 h after surgery when compared to presurgery values, indicating that
cardiac surgery is associated with circulatory neutrophil priming. The number of
neutrophils markedly increased at the end of cardiopulmonary bypass and reached a
peak 12 h after surgery. The circulatory neutrophils of cardiac surgical patients
become primed after surgery, coincident with the peak neutrophil count. These
results suggest that circulatory neutrophils after cardiac surgery with CPB have
enhanced responsiveness and are predisposed to systemic inflammation.
PMID- 10677156
TI - Pressure drop, shear stress, and activation of leukocytes during cardiopulmonary
bypass: a comparison between hollow fiber and flat sheet membrane oxygenators.
AB - The membrane oxygenator is known to be superior to the bubble oxygenator, but
little information is available about the difference between the hollow fiber and
flat sheet membrane oxygenators with regard to pressure drop, shear stress, and
leukocyte activation. In this study, we compared these 2 types of membrane
oxygenators in patients undergoing cardiopulmonary bypass (CPB) surgery with
special focus on leukocyte activation and pressure drop across the oxygenators.
Plasma concentration of elastase, a marker indicating leukocyte activation,
increased to 593+/-68% in the flat sheet oxygenator group versus 197+/-42% in the
hollow fiber oxygenator group (p<0.01) at the end of CPB compared to their
respective baseline concentrations before CPB. Pressure drop across the
oxygenator was significantly higher in the flat sheet group than in the hollow
fiber group throughout the entire period of CPB (p<0.01). High pressure drop
across the oxygenator as well as the calculated shear stress was positively
correlated with the release of elastase at the end of CPB (r = 0.760, p<0.01, r =
0.692, p<0.01). However, this positive correlation existed in the flat sheet
oxygenator but not in the hollow fiber oxygenator. Clinically, both membrane
oxygenators have satisfactory performance in O2 and CO2 transfer. These results
suggest that a higher pressure drop across the flat sheet oxygenator is
associated with more pronounced activation of leukocytes in patients undergoing
cardiopulmonary bypass.
PMID- 10677157
TI - Maintenance of blood heparin concentration rather than activated clotting time
better preserves the coagulation system in hypothermic cardiopulmonary bypass.
AB - In cardiopulmonary bypass (CPB), despite heparin regimens in which the activated
clotting time (ACT) is kept at more than 400 s, there is biochemical evidence of
thrombin generation indicating activation of the coagulation system and increased
fibrinolytic activity. Therefore, to reduce the coagulant activation has been one
of the main issues in the improvement of CPB. The purpose of this study was to
compare the heparin concentration with the ACT and to evaluate the effect of
keeping higher heparin concentration on the coagulation and fibrinolytic systems
during hypothermic CPB, employing moderate hypothermia (MHT) or deep hypothermic
circulatory arrest (DHT). Heparin was either administered to maintain an ACT >400
s (ACT group) or to maintain a whole blood heparin concentration of 3 mg/kg
(heparin group). At the lowest core temperature during CPB, the ACT and the
heparinase ACT (unrelated to heparin concentration) were increased the most
whereas the whole blood heparin concentration was less than half the initial
concentration in both ACT groups of MHT and DHT. The thrombin-antithrombin III
(TAT) content just after CPB in both MHT and DHT was significantly lower in the
heparin group than in the ACT group. In conclusion, ACT does not reflect the
whole blood heparin concentration during hypothermic CPB. Furthermore,
maintenance of the higher heparin concentration during hypothermic CPB may
suppress the activation of the coagulation system via thrombin inhibition. That
effect was more remarkable in deep hypothermic CPB. Therefore, we believe that
anticoagulation management during hypothermic CPB should be based on the
maintenance of the higher blood heparin concentration.
PMID- 10677158
TI - Hydrodynamic evaluation of three artificial aortic valve chambers.
AB - The effect of chamber geometry on the characteristics of turbulent steady flow
through a newly designed artificial heart valve, "the jellyfish valve," has been
investigated for flow rates matching those of peak systole. Laser Doppler
Anemometry (LDA) was employed to determine the velocity and shear stress
distributions at various locations downstream of the jellyfish valve. Three
geometrically different aortic valve chambers have been investigated: namely, a
chamber with sinuses of Valsalva, an ellipsoidal chamber, and a cylindrical
chamber. The results of this investigation indicated that the aorta with sinuses
of Valsalva model had the highest turbulent shear stresses whereas the
ellipsoidal model gave the highest-pressure drops. However, for the various flow
rates examined, including the systole peak value of 26 L/min, it appears that the
ellipsoidal model displays better hydrodynamic characteristics in terms of shear
stress and uniformity of axial velocity distributions downstream of the jellyfish
valve.
PMID- 10677159
TI - Evaluation of the inner-surface morphology of an artificial heart by acoustic
microscopy.
AB - The total artificial heart (TAH) is being developed for permanent replacement of
the natural heart instead of heart transplantation. The need for detecting the
material fatigue in the TAH is increasing in order to guarantee long-term use. In
this study, the inner surface morphology of the TAH was evaluated by a specially
developed scanning acoustic microscope (SAM) system operating in the frequency
range of 100-200 MHz. The inner sac of our TAH consisted of polyvinylchloride
coated with polyurethane, and the SAM investigations were performed before and
after the implantations in goats. The amplitude images of the SAM demonstrated
protein adhesion on the inner surface of the TAH after the animal experiment, and
the phase images showed distortion of the wall with spatial resolution of 0.2
microm. These results suggest the feasibility of a high-frequency ultrasound for
evaluating the material fatigue of TAH.
PMID- 10677160
TI - Significance of percutaneous cardiopulmonary bypass support for volume reduction
surgery with severe hypercapnia.
AB - In patients with reduced respiratory function, lung resection is associated with
high risk because separate ventilation is generally needed for safe management.
For patients with end-stage emphysema, intraoperative respiratory management is
important and particularly difficult because neither incomplete oxygenation nor
selective ventilation can be performed, so the operation may be interrupted. In
this study, we assess the effectiveness of the percutaneous cardiopulmonary
support (PCPS) system for lung volume reduction surgery in patients with severe
hypercapnia (arterial carbon dioxide tension >50 mm Hg) and discuss the
significance of PCPS for patients who are beyond the standard criteria for lung
volume reduction surgery (LVRS). We studied 3 patients with severe hypercapnia
due to emphysema who underwent volume reduction surgery. One patient was
previously treated surgically for contralateral pneumothorax. All patients had a
severe smoking history and were suspected to have fragile lungs. During the
operation. PCPS provided sufficient support flow. Intraoperative management using
PCPS was easy, and no severe complications were observed. One patient exhibited
severe hemodynamic deterioration on postoperative Day 15. Other patients' PaCO2
improved postoperatively. One had a calcification of a femoral artery, but there
was no trouble inserting a cannula. Bilateral or unilateral volume reduction
surgery was performed under PCPS in patients with end-stage emphysema. We
conclude that PCPS is an adjunct to LVRS, useful for intraoperative management of
some patients with severe hypercapnea, and the LVRS indications can be extended.
PMID- 10677161
TI - Five-year follow-up of valve replacement with the Jyros bileaflet mechanical
valve.
AB - Jyros bileaflet rotating valves were implanted as a clinical trial conducted in
Japan, and the 5-year results were assessed. Nineteen patients underwent
implantation of the valves: 14 in the mitral and 5 in the aortic position. The
mean follow-up period was 65.4+/-15.7 months. There was 1 case of late death due
to fatal arrhythmia and another case of cerebral thromboembolism (1.0% per
patient year). All survivors were in New York Heart Association class I. On the
early postoperative cinefluorography, 8 valves (42.1%) showed rotation of the
leaflets. However, in the latest assessment 6 valves (33.3%) showed rotation,
some valves had stopped rotation, and others had started to rotate during the
follow-up period. The Jyros valve functions effectively, similar to other
bileaflet valves. However, because the correlation between thromboembolism and
the rotation mechanism is not clear, further follow-up of our patients and more
implant studies are necessary to elucidate this issue.
PMID- 10677162
TI - A clinical use of the Kyocera Gyro C1E3 centrifugal pump.
AB - The Kyocera Gyro C1E3 centrifugal blood pump was clinically applied for a
cardiopulmonary bypass (CPB) of coronary artery bypass grafting (CABG). The
patient was 72-year-old male with postinfarction unstable angina. The surgery was
carried out on November 20, 1998. The air inside the pump was easily and quickly
removed, and its controllability was excellent. The pump flow during operation
was maintained 2.2 L/m2. Total CPB time was 173 min. Perioperative parameters of
hemolysis and cytotoxicity were not remarkably changed. Macroscopically and
microscopically, there were no thrombi inside the pump after usage. This is the
first reported case of clinical use of the Kyocera Gyro C1E3 pump.
PMID- 10677163
TI - Epidemiology and molecular genetics of colorectal cancer.
AB - Colorectal cancer is among the most common cancers affecting the western world.
By the age of 70 yr, at least 50% of the Western population will develop some
form of colorectal tumor, spanning the spectrum from an early benign polyp to an
invasive adenocarcinoma. It is estimated that approximately 10% of the benign
polypoid lesions will progress to invasive carcinoma. The concept that serial
genetic changes are responsible for the transition from benign to neoplastic
disease is not new. The description of hereditary cancers and the demonstration
of carcinogenic substances inducing DNA damage have provided the foundation for
the field of molecular oncology. During the past three decades, our understanding
of how genetic alterations culminate in cancer has progressed rapidly, though the
complete process has not been fully defined. The research to date has spanned
many oncologic diseases, but has been especially well defined in colorectal
cancer. The knowledge of the genetic alterations that result in colorectal cancer
has important ramifications for future prevention, detection, and treatment of
this disease.
PMID- 10677164
TI - Colorectal cancer screening and follow-up.
AB - Cancer of the colon and rectum is a significant health problem in the United
States. Nearly 50% of the 186,000 patients diagnosed annually with colorectal
cancer will eventually die of their disease. Because development of a colorectal
carcinoma is most frequently preceded by the development of a well-recognized pre
malignant lesion, screening modalities can significantly impact the incidence and
mortality rate of this disease. Population screening employing digital rectal
examination, fecal occult blood testing and endoscopic examination of the rectum
and colon has been demonstrated to reduce the risk of death from colorectal
cancer. Screening regimens should be instituted at an earlier age and with
increased frequency for patients in the highest risk categories. Patients who
have been treated for a cancer of the colon or rectum should undergo surveillance
at regular intervals in an attempt to identify recurrences of disease both in the
residual colon and rectum and at distant sites. Most physicians and patients
believe that intensive follow-up strategies will afford improved survival and
quality of life, however few randomized studies examining the utility of
intensive follow-up programs have been performed and the quality of cancer
related follow-up literature is generally poor. Good-quality clinical trials are
needed to sort out which tests make a difference in the patient's long-term
outcome. The algorithm for surveillance for recurrence in the future may be
altered as newer testing modalities are developed.
PMID- 10677165
TI - Tumor markers--prognostic and therapeutic implications for colorectal carcinoma.
AB - Molecular prognostic markers are molecules produced by either the tumor or the
host (patient) whose expression is associated with the clinical outcome. Three
types of molecular markers exist that characterize different aspects of the tumor
: host relationship: (1) tumor biology, (2) tumor burden and (3) host response.
The first type of marker is measured within the primary or metastatic tumor mass
and defines the aggressiveness of the cancer and its ability to respond to
therapy. The other two types of markers are usually measured in the blood and
assess concentrations of circulating tumor products or cytokines that may be
involved in host resistance to the cancer. In this brief review we will define
each type of marker, provide examples of their current utility and then describe
how these markers may be useful.
PMID- 10677166
TI - Surgical management of primary colorectal cancer.
AB - Surgery for potentially curable colorectal cancer most commonly involves
resection of the primary tumor and regional lymph nodes. However, the site,
extent and presentation of disease have an impact on surgical strategy and the
use of combined modality therapy. For colon cancer, complex presentations such as
obstructing or perforated colon cancer may influence surgical therapy, and issues
pertaining to en bloc resection and oophorectomy remain unresolved. For rectal
cancer, surgical management may range from local excision to radical resection.
Extent of resection and relatively new operative techniques such as coloanal
anastomosis with or without a colonic pouch reservoir are directed towards
optimizing both oncologic and functional results.
PMID- 10677167
TI - Minimally invasive techniques for colorectal cancer.
AB - Laparoscopic approaches are increasingly being applied to colorectal surgical
procedures. Initial concerns regarding the existence of benefits from the
laparoscopic approach have now been addressed. Even as these were being
addressed, however, further concerns arose regarding the appropriateness of this
technique in malignancy. Colorectal cancer is the only intra-abdominal malignancy
that is knowingly resected employing laparoscopic techniques. This controversy
was highlighted by reports of early wound implants. With careful technique,
training and experience, however, wound recurrences are rarely seen, suggesting
that this phenomenon, in the clinical setting, is primarily technique-related.
Lack of rigorous evidence either condemning or supporting the laparoscopic
approach for colorectal cancer resulted in the establishment of several large
scale randomized, prospective trials, all currently in progress, that aim to
determine if laparoscopic resection of colorectal cancer results in oncologic
outcomes comparable to the open approach.
PMID- 10677168
TI - Adjuvant and neoadjuvant chemoradiation therapy for primary colorectal cancer.
AB - The management of rectal cancer presents substantial challenges. Patients with T3
and/or node-positive rectal cancers are at high risk for local failure and
distant metastases (DM). Adjuvant radiation has been shown to decrease local
recurrence (LR) rates; however, this local therapy has not been demonstrated to
improve survival when compared to surgery alone. In several prospective
randomized trials adjuvant chemoradiation with 5-fluorouracil-(5-FU)-based
chemotherapy improved LR rates, DM rates, and overall survival (OS). The optimal
chemotherapeutic regimen has not been determined; however, studies comparing
standard IV bolus 5-FU administration with continuous infusion (CI) 5-FU
demonstrated that CI administration was superior. Preoperative therapy has
potential advantages over adjuvant therapy such as less acute bowel toxicity and
improved sphincter preservation. Preoperative chemoradiation has been shown in
several studies to improve LR rates and OS when compared to surgery alone. Our
current approach to patients with resectable T3 or N1 cancer in the distal two
thirds of the rectum on preoperative staging is preoperative chemoradiation with
planned postoperative chemotherapy. This regimen offers the best chance for local
control and disease-free survival while potentially downstaging the tumor and
improving sphincter preservation.
PMID- 10677169
TI - Molecular determinants of colon cancer metastasis.
AB - Colon cancer metastasis is a tightly regulated process that requires a cancer
cell to express genes that allow progression through various distinct steps.
Aberrations in gene expression by cancer cells leads to transformation, growth,
angiogenesis, invasion, dissemination and survival in the circulation, attachment
in the organ of metastasis, and again invasion, growth, and angiogenesis. In
addition to the genotype/phenotype of the tumor cell, for a tumor cell to become
a clinically relevant metastasis, it must be able to respond appropriately to the
environment. This includes being able to utilize growth factors and blood vessels
from the organ of metastasis for the benefit of the tumor mass. Understanding the
molecular and biologic mechanisms of colon cancer metastasis will allow the
development of rationale therapeutic strategies that are more likely to impact
the natural history of this disease than current therapies.
PMID- 10677170
TI - Multidisciplinary management of metastatic colorectal cancer.
AB - When colorectal cancer metastasizes to distant organs, usually multiple sites are
involved and treatment consists primarily of systemic chemotherapy and supportive
care. Chemotherapeutic agents effective against metastatic colorectal cancer
include 5-fluorouracil, often used in combination with leucovorin or
methotrexate, and irinotecan (CPT-11). Median survival with optimal chemotherapy
regimens ranges from 10 to 15 months. Less frequently, colorectal cancer
metastasizes only to the liver or lung. In a minority of these cases, surgical
resection can be performed and results in a median survival of 28-46 months for
hepatic resections and 24-25 months for pulmonary resections. Five-year survival
rates range from 24 to 38% and 21 to 44% for hepatic and pulmonary resections,
respectively. For isolated liver metastases that are not surgically resectable,
other regional therapies that can be considered are hepatic cryosurgery,
radiofrequency ablation, and hepatic arterial infusion chemotherapy. Median
survival following cryosurgery is between 26 and 30 months, while median survival
following radiofrequency ablation has not been established in large series.
Hepatic arterial infusion chemotherapy, especially with newer combination drug
regimens, may increase survival in patients with isolated liver metastases
compared to systemic chemotherapy, but this must be confirmed in randomized,
prospective trials. Colorectal cancer metastases to the brain can be treated with
radiation therapy or surgical resection, but median survival with treatment is
less than one year.
PMID- 10677171
TI - Multidisciplinary management of recurrent colorectal cancer.
AB - Isolated pelvic recurrence of rectal carcinoma may occur in up to one third of
patients following definitive resection of primary disease. The means by which
recurrence is diagnosed, methods by which it may be treated, and reported
outcomes are all evolving and improving. Current data indicate that a substantial
proportion of patients treated by aggressive multi-modality salvage therapy may
be provided with durable survival. This review highlights current concepts in the
diagnosis and management of locally recurrent rectal carcinoma.
PMID- 10677172
TI - [Etiopathogeny of fetal macrosomia].
AB - Fetal macrosomia is an heterogeneous condition in terms of definition and
etiologic factors. Recent findings suggest that macrosomia should not be
classified on the basis of birth weight and gestational age alone. The ponderal
index delineates a symmetric and an asymmetric subtype of macrosomia. The
relationship between maternal diabetes and fetal macrosomia has been extensively
investigated. However, eighty percent of macrosomic infants are born to mothers
who are not hyperglycemic, and various factors have been associated. Maternal
factors explain approximately 50% of the variance in birth weight, whereas
paternal factors have no significant effect. The predisposition to excessive
fetal growth may be shared within the intra uterine environment and the fetal
genome. The respective roles of lipids, amino acids, hormones such as leptin, and
growth factors need to be evaluated. Perinatal morbidity and long term
consequences such as obesity and glucose intolerance might be associated with
some of the factors leading to fetal overgrowth.
PMID- 10677173
TI - [Psychotropes and pregnancy].
PMID- 10677180
TI - Dental fillings. The silver in them thar molars.
PMID- 10677181
TI - Mental health. Adult attention deficit hyperactivity disorder.
PMID- 10677182
TI - Health beat. Targeted chemotherapy.
PMID- 10677184
TI - Caregiving. The health hazards of helping.
PMID- 10677183
TI - By the way, doctor. I lost my sense of taste and smell about four years ago. I
like to eat - always have - and I do what I can to keep on enjoying it by paying
attention to how the food looks, how it feels in my mouth, and my memories of it.
But it isn't the same. Is there anything that can be done? I'm 83 and in good
health.
PMID- 10677185
TI - General review: personality disorders - part I.
PMID- 10677186
TI - Insights: emotional illness and creativity: a psychoanalytic perspective.
PMID- 10677187
TI - Is ritalin underused?
PMID- 10677188
TI - Gay youth at risk.
PMID- 10677189
TI - Forum. How should suicidal behavior be managed?
PMID- 10677190
TI - The mortality of men in Russia: a cautionary tale.
PMID- 10677191
TI - To err is human, but...
PMID- 10677192
TI - Sexuality. It takes two: coping with erectile dysfunction.
PMID- 10677194
TI - Lyme disease update.
PMID- 10677193
TI - Feet. Taking steps toward good health.
PMID- 10677195
TI - By the way, doctor. I recently read that a test for the virus linked to cervical
cancer may be better than a Pap smear. Does this mean I can avoid a regular
pelvic exam and Pap smear? Should I ask my doctor for this test?
PMID- 10677200
TI - Health beat. Vitamin E: E for exaggerated?
PMID- 10677201
TI - By the way, doctor. I went through menopause about 10 years ago and have been
taking estrogen therapy ever since. My uterus was removed because of fibroids, so
there is no risk of endometrial cancer, which is why I am taking estrogen without
progesterone. Should I have a bone density scan? A lot of my friends are having
them, but I'm not sure how this test could alter my therapy.
PMID- 10677202
TI - Nalmefene for alcohol dependence.
PMID- 10677203
TI - GERD: more than just heartburn.
PMID- 10677204
TI - The healthiness of the long-distance runner.
PMID- 10677205
TI - On call: I am a 68-year-old man who had bypass surgery last month. My heart did
fine, but I had trouble urinating after my urinary catheter came out. The problem
cleared up in a day, but my doctor ordered a PSA test, which came back high
(7.8). I don't feel up to another operation. What should I do?
PMID- 10677206
TI - The spasmodic peptide defines a new conotoxin superfamily.
AB - We purified and characterized a peptide from the venom of Conus textile that
makes normal mice assume the phenotype of a well-known mutant, the spasmodic
mouse. This "spasmodic" peptide has 27 amino acids, including two gamma
carboxyglutamate (Gla) residues. A cDNA clone encoding the precursor for the
peptide was identified; a gamma-carboxylation recognition signal sequence (gamma
CRS) is present in the -1 --> -20 region of the peptide precursor. Both the gamma
CRS and the position of the Gla residues in the mature toxin are notably
different from other Gla-containing conopeptides. The spasmodic peptide has a
novel disulfide framework and distinct signal sequence which together define a
new P-superfamily of conopeptides. A cDNA encoding another member of the P
superfamily was identified from a different species, Conus gloriamaris.
PMID- 10677207
TI - Crystal structure of the second domain of the human copper chaperone for
superoxide dismutase.
AB - The human copper chaperone for superoxide dismutase (hCCS) delivers the essential
copper ion cofactor to copper,zinc superoxide dismutase (SOD1), a key enzyme in
antioxidant defense. Mutations in SOD1 are linked to familial amyotrophic lateral
sclerosis (FALS), a fatal neurodegenerative disorder. The molecular mechanisms by
which SOD1 is recognized and activated by hCCS are not understood. To better
understand this biochemical pathway, we have determined the X-ray structure of
the largest domain of hCCS (hCCS Domain II) to 2. 75 A resolution. The overall
structure is closely related to that of its target enzyme SOD1, consisting of an
eight-stranded beta-barrel and a zinc-binding site formed by two extended loops.
The first of these loops provides the ligands to a bound zinc ion, and is
analogous to the zinc subloop in SOD1. The second structurally resembles the SOD1
electrostatic channel loop, but lacks many of the residues important for
catalysis. Like SOD1 and yCCS, hCCS forms a dimer using a highly conserved
interface. In contrast to SOD1, however, the hCCS structure does not contain a
copper ion bound in the catalytic site. Notably, the structure reveals a single
loop proximal to the dimer interface which is unique to the CCS chaperones.
PMID- 10677208
TI - Hybrid and complex glycans are linked to the conserved N-glycosylation site of
the third eight-cysteine domain of LTBP-1 in insect cells.
AB - Covalent association of LTBP-1 (latent TGF-beta binding protein-1) to latent TGF
beta is mediated by the third eight-cysteine (also referred to as TB) module of
LTBP-1, a domain designated as CR3. Spodoptera frugiperda (Sf9) cells have proved
a suitable cell system in which to study this association and to produce
recombinant CR3, and we show here that another lepidopteran cell line,
Trichoplusia niTN-5B1-4 (High-Five) cells, allows the recovery of large amounts
of functional recombinant CR3. CR3 contains an N-glycosylation site, which is
conserved in all forms of LTBP known to date. When we examined the status of this
N-glycosylation using MALDI-TOF mass spectrometry and enzymatic analysis, we
found that CR3 is one of the rare recombinant peptides modified with complex
glycans in insect cells. Sf9 cells mainly processed the fucosylated
paucomannosidic structure (GlcNAc)(2)(Mannose)(3)Fucose, although hybrid and
complex N-glycosylations were also detected. In High-Five cells, the peptide was
found to be modified with a wide variety of hybrid and complex sugars in addition
to paucomanosidic oligosaccharides. Most glycans had one or two fucose residues
bound through alpha1,3 and alpha1,6 linkages to the innermost GlcNAc. On the
basis of these results and on the structure of an eight-cysteine domain from
fibrillin-1, we present a model of glycosylated CR3 and discuss the role of
glycosylation in eight-cysteine domain protein-protein interactions.
PMID- 10677209
TI - The NMR structure of the nucleocapsid protein from the mouse mammary tumor virus
reveals unusual folding of the C-terminal zinc knuckle.
AB - The nucleocapsid protein (NC) from the mouse mammary tumor virus (MMTV) has been
overexpressed in Escherichia coli and purified to homogeneity for structural
studies by nuclear magnetic resonance (NMR) spectroscopy. The protein contains
two copies of a conserved zinc-coordinating "CCHC array" or "zinc knuckle" motif
common to the nucleocapsid proteins of nearly all known retroviruses. The
residues comprising and adjacent to the zinc knuckles were assigned by standard
two-dimensional (1)H and three-dimensional (1)H-(15)N NMR methods; the rotational
dynamic properties of the protein were determined from (15)N relaxation
experiments, and distance restraints derived from the nuclear Overhauser effect
(NOE) data were used to calculate the three-dimensional structure. The (1)H-(1)H
NOE and (15)N relaxation data indicate that the two zinc knuckles do not interact
with each other, but instead behave as independently folded domains connected by
a flexible 13-residue linker segment. The proximal zinc knuckle folds in a manner
that is essentially identical to that observed previously for the two zinc
knuckles of the human immunodeficiency virus type 1 nucleocapsid protein and for
the moloney murine leukemia virus nucleocapsid zinc knuckle domain. However, the
distal zinc knuckle of MMTV NC exhibits a rare three-dimensional fold that
includes an additional C-terminal beta-hairpin. A similar C-terminal reverse turn
like structure was observed recently in the distal zinc knuckle of the Mason
Pfizer monkey virus nucleocapsid protein [Gao, Y., et al. (1998) Protein Sci. 7,
2265-2280]. However, despite a high degree of sequence homology, the conformation
and orientation of the beta-hairpin in MMTV NC is significantly different from
that of the reverse turn in MPMV NC. The results support the conclusion that
structural features of NC zinc knuckle domains can vary significantly among the
different genera of retroviridae, and are discussed in terms of the recent and
surprising discovery that MMTV NC can facilitate packaging of the HIV-1 genome in
chimeric MMTV mutants.
PMID- 10677210
TI - Crystal structure of adenosine 5'-phosphosulfate kinase from Penicillium
chrysogenum.
AB - Adenosine 5'-phosphosulfate (APS) kinase catalyzes the second reaction in the two
step conversion of inorganic sulfate to 3'-phosphoadenosine 5'-phosphosulfate
(PAPS). This report presents the 2.0 A resolution crystal structure of ligand
free APS kinase from the filamentous fungus, Penicillium chrysogenum. The enzyme
crystallized as a homodimer with each subunit folded into a classic kinase motif
consisting of a twisted, parallel beta-sheet sandwiched between two alpha-helical
bundles. The Walker A motif, (32)GLSASGKS(39), formed the predicted P-loop
structure. Superposition of the APS kinase active site region onto several other
P-loop-containing proteins revealed that the conserved aspartate residue that
usually interacts with the Mg(2+) coordination sphere of MgATP is absent in APS
kinase. However, upon MgATP binding, a different aspartate, Asp 61, could shift
and bind to the Mg(2+). The sequence (156)KAREGVIKEFT(166), which has been
suggested to be a (P)APS motif, is located in a highly protease-susceptible loop
that is disordered in both subunits of the free enzyme. MgATP or MgADP protects
against proteolysis; APS alone has no effect but augments the protection provided
by MgADP. The results suggest that the loop lacks a fixed structure until MgATP
or MgADP is bound. The subsequent conformational change together with the
potential change promoted by the interaction of MgATP with Asp 61 may define the
APS binding site. This model is consistent with the obligatory ordered substrate
binding sequence (MgATP or MgADP before APS) as established from steady state
kinetics and equilibrium binding studies.
PMID- 10677211
TI - Computational methodology for estimating changes in free energies of biomolecular
association upon mutation. The importance of bound water in dimer-tetramer
assembly for beta 37 mutant hemoglobins.
AB - The computational modeling program HINT (Hydropathic INTeractions), an empirical
hydropathic force field that includes hydrogen bonding, Coulombic, and
hydrophobic terms, was used to model the free energy of dimer-tetramer
association in a series of deoxy hemoglobin beta 37 double mutants. Five of the
analyzed mutants (beta 37W --> Y, beta 37W --> A, beta 37W --> G, beta 37W --> E,
and beta 37W --> R) have been solved crystallographically and characterized
thermodynamically and subsequently made a good test set for the calibration of
our method as a tool for free energy prediction. Initial free energy estimates
for these mutants were conducted without the inclusion of crystallographically
conserved water molecules and systematically underestimated the experimentally
calculated loss in free energy observed for each mutant dimer-tetramer
association. However, the inclusion of crystallographic waters, interacting at
the dimer-dimer interface of each mutant, resulted in HINT free energy estimates
that were more accurate with respect to experimental data. To evaluate the
ability of our method to predict free energies for de novo protein models, the
same beta 37 mutants were computationally generated from native deoxy hemoglobin
and similarly analyzed. Our theoretical models were sufficiently robust to
accurately predict free energy changes in a localized region around the mutated
residue. However, our method did not possess the capacity to generate the long
range secondary structural effects observed in crystallographically solved mutant
structures. Final method analysis involved the computational generation of
structurally and/or thermodynamically uncharacterized beta 37 deoxy hemoglobin
mutants. HINT analysis of these structures revealed that free energy predictions
for dimer-tetramer association in these models agreed well with previously
observed energy predictions for structurally and thermodynamically characterized
beta 37 deoxy hemoglobin mutants.
PMID- 10677212
TI - Helical interactions in the HIV-1 gp41 core reveal structural basis for the
inhibitory activity of gp41 peptides.
AB - The HIV-1 gp41 envelope protein mediates membrane fusion that leads to virus
entry into the cell. The core structure of fusion-active gp41 is a six-helix
bundle in which an N-terminal three-stranded coiled coil is surrounded by a
sheath of antiparallel C-terminal helices. A conserved glutamine (Gln 652) buried
in this helical interface replaced by leucine increases HIV-1 infectivity. To
define the basis for this enhanced membrane fusion activity, we investigate the
role of the Gln 652 to Leu substitution on the conformation, stability, and
biological activity of the N34(L6)C28 model of the gp41 ectodomain core. The 2.0
A resolution crystal structure of the mutant molecule shows that the Leu 652 side
chains make prominent contacts with hydrophobic grooves on the surface of the
central coiled coil. The Gln 652 to Leu mutation leads to a marginal
stabilization of the six-helix bundle by -0.8 kcal/mol, evaluated from thermal
unfolding experiments. Strikingly, the mutant N34(L6)C28 peptide is a potent
inhibitor of HIV-1 infection, with 10-fold greater activity than the wild-type
molecule. This inhibitory potency can be traced to the corresponding C-terminal
mutant peptide that likely has greater potential to interact with the coiled-coil
trimer. These results provide strong evidence that conserved interhelical packing
interactions in the gp41 core are important determinants of HIV-1 entry and its
inhibition. These interactions also offer a test-bed for the development of more
potent analogues of gp41 peptide inhibitors.
PMID- 10677213
TI - Characterization of a novel DNA primase from the Salmonella typhimurium
bacteriophage SP6.
AB - The gene for the DNA primase encoded by Salmonella typhimurium bacteriophage SP6
has been cloned and expressed in Escherichia coli and its 74-kDa protein product
purified to homogeneity. The SP6 primase is a DNA-dependent RNA polymerase that
synthesizes short oligoribonucleotides containing each of the four canonical
ribonucleotides. GTP and CTP are both required for the initiation of
oligoribonucleotide synthesis. In reactions containing only GTP and CTP, SP6
primase incorporates GTP at the 5'-end of oligoribonucleotides and CMP at the
second position. On synthetic DNA templates, pppGpC dinucleotides are synthesized
most rapidly in the presence of the sequence 5'-GCA-3'. This trinucleotide
sequence, containing a cryptic dA at the 3'-end, differs from other known
bacterial and phage primase recognition sites. SP6 primase shares some properties
with the well-characterized E. colibacteriophage T7 primase. The T7 DNA
polymerase can use oligoribonucleotides synthesized by SP6 primase as primers for
DNA synthesis. However, oligoribonucleotide synthesis by SP6 primase is not
stimulated by either the E. coli- or the T7-encoded ssDNA binding protein. An
amino acid sequence alignment of the SP6 and T7 primases, which share only 22.4%
amino acid identity, indicates amino acids likely critical for
oligoribonucleotide synthesis as well as a putative Cys(3)His zinc finger motif
that may be involved in DNA binding.
PMID- 10677214
TI - Mutational, kinetic, and NMR studies of the roles of conserved glutamate residues
and of lysine-39 in the mechanism of the MutT pyrophosphohydrolase.
AB - The MutT enzyme catalyzes the hydrolysis of nucleoside triphosphates (NTP) to NMP
and PP(i) by nucleophilic substitution at the rarely attacked beta-phosphorus.
The solution structure of the quaternary E-M(2+)-AMPCPP-M(2+) complex indicated
that conserved residues Glu-53, -56, -57, and -98 are at the active site near the
bound divalent cation possibly serving as metal ligands, Lys-39 is positioned to
promote departure of the NMP leaving group, and Glu-44 precedes helix I (residues
47-59) possibly stabilizing this helix which contributes four catalytic residues
to the active site [Lin, J. , Abeygunawardana, C., Frick, D. N., Bessman, M. J.,
and Mildvan, A. S. (1997) Biochemistry 36, 1199-1211]. To test these proposed
roles, the effects of mutations of each of these residues on the kinetic
parameters and on the Mn(2+), Mg(2+), and substrate binding properties were
examined. The largest decreases in k(cat) for the Mg(2+)-activated enzyme of
10(4.7)- and 10(2.6)-fold were observed for the E53Q and E53D mutants,
respectively, while 97-, 48-, 25-, and 14-fold decreases were observed for the
E44D, E56D, E56Q, and E44Q mutations, respectively. Smaller effects on k(cat)
were observed for mutations of Glu-98 and Lys-39. For wild type MutT and its E53D
and E44D mutants, plots of log(k(cat)) versus pH exhibited a limiting slope of 1
on the ascending limb and then a hump, i.e., a sharply defined maximum near pH 8
followed by a plateau, yielding apparent pK(a) values of 7.6 +/- 0.3 and 8.4 +/-
0.4 for an essential base and a nonessential acid catalyst, respectively, in the
active quaternary MutT-Mg(2+)-dGTP-Mg(2+) complex. The pK(a) of 7.6 is assigned
to Glu-53, functioning as a base catalyst in the active quaternary complex, on
the basis of the disappearance of the ascending limb of the pH-rate profile of
the E53Q mutant, and its restoration in the E53D mutant with a 10(1.9)-fold
increase in (k(cat))(max). The pK(a) of 8.4 is assigned to Lys-39 on the basis of
the disappearance of the descending limb of the pH-rate profile of the K39Q
mutant, and the observation that removal of the positive charge of Lys-39, by
either deprotonation or mutation, results in the same 8.7-fold decrease in
k(cat). Values of k(cat) of both wild type MutT and the E53Q mutant were
independent of solvent viscosity, indicating that a chemical step is likely to be
rate-limiting with both. A liganding role for Glu-53 and Glu-56, but not Glu-98,
in the binary E-M(2+) complex is indicated by the observation that the E53Q,
E53D, E56Q, and E56D mutants bound Mn(2+) at the active site 36-, 27-, 4.7-, and
1.9-fold weaker, and exhibited 2.10-, 1.50-, 1.12-, and 1.24-fold lower enhanced
paramagnetic effects of Mn(2+), respectively, than the wild type enzyme as
detected by 1/T(1) values of water protons, consistent with the loss of a metal
ligand. However, the K(m) values of Mg(2+) and Mn(2+) indicate that Glu-56, and
to a lesser degree Glu-98, contribute to metal binding in the active quaternary
complex. Mutations of the more distant but conserved residue Glu-44 had little
effect on metal binding or enhancement factors in the binary E-M(2+) complexes.
Two-dimensional (1)H-(15)N HSQC and three-dimensional (1)H-(15)N NOESY-HSQC
spectra of the kinetically damaged E53Q and E56Q mutants showed largely intact
proteins with structural changes near the mutated residues. Structural changes in
the kinetically more damaged E44D mutant detected in (1)H-(15)N HSQC spectra were
largely limited to the loop I-helix I motif, suggesting that Glu-44 stabilizes
the active site region. (1)H-(15)N HSQC titrations of the E53Q, E56Q, and E44D
mutants with dGTP showed changes in chemical shifts of residues lining the active
site cleft, and revealed tighter nucleotide binding by these mutants, indicating
an intact substrate binding site. (ABSTRACT TRUNCATED)
PMID- 10677215
TI - Active intracellular domain of Notch enhances transcriptional activation of
CCAAT/enhancer binding protein beta on a rat pregnancy-specific glycoprotein
gene.
AB - Pregnancy-specific glycoproteins (PSGs) are primarily expressed in the placenta
and become the major glycoproteins at term. To understand the regulation of PSG
expression, we characterized the promoter elements of a rodent PSG gene, rnCGM3,
and delineated three nuclear protein binding sites: FPI, -II, and -III in the 5'
flanking region of the gene. The FPII-binding factor is shown to be C/EBPbeta,
which positively regulates rnCGM3 expression [Chen, H., et al. (1995) DNA Cell
Biol. 14, 681-688]. In the current study, we used the yeast one-hybrid system to
isolate transcription factors binding to the FPIII site and demonstrated that a
rodent J kappa recombination signal sequence binding protein, rRBPJ kappa-2N,
bound to the FPIII site. Electrophoretic mobility shift assay with rat placental
nuclear proteins revealed a constitutive occupancy of the FPIII site by RBPJ
kappa. By transient expression analyses, we demonstrated that rRBPJ kappa-2N
repressed the expression from an FPIII-driven SV40 promoter. However, this
repression effect was counteracted by the active intracellular domain of Notch
(NotchIC). Using the native rnCGM3 promoter construct, we demonstrated that the
promoter activity stimulated by C/EBP beta was also repressed by rRBPJ kappa-2N
but enhanced by NotchIC. Additionally, we found that NotchIC can stimulate
expression through another RBPJkappa site within the FPI site. A functional
interaction between factors binding to the FPI, FPII, and FPIII sites is
proposed.
PMID- 10677216
TI - RPD3-type histone deacetylases in maize embryos.
AB - Posttranslational core histone acetylation is established and maintained by
histone acetyltransferases and deacetylases. Both have been identified as
important transcriptional regulators in various eukaryotic systems. In contrast
to nonplant systems where only RPD3-related histone deacetylases (HD) have been
characterized so far, maize embryos contain three unrelated families of
deacetylases (HD1A, HD1B, and HD2). Purification, cDNA cloning, and immunological
studies identified the two maize histone deacetylase HD1B forms as close
homologues of the RPD3-type deacetylase HDAC1. Unlike the other maize
deacetylases, HD1A and nucleolar HD2, HD1B copurified as a complex with a protein
related to the retinoblastoma-associated protein, Rbap46. Two HD1B mRNA species
could be detected on RNA blots, encoding proteins of 58 kDa (HD1B-I) and 51 kDa
(HD1B-II). HD1B-I (zmRpd3) represents the major enzyme form as judged from RNA
and immunoblots. Levels of expression of HD1B-I and -II mRNA differ during early
embryo germination; HD1B-I mRNA and protein are present during the entire
germination pathway, even in the quiescent embryo, whereas HD1B-II expression
starts when meristematic cells enter S-phase of the cell cycle. In line with
previous results, HD1B exists as soluble and chromatin-bound enzyme forms. In
vivo treatment of meristematic tissue with the deacetylase inhibitor HC toxin
does not affect the expression of the three maize histone deacetylases, whereas
it causes downregulation of histone acetyltransferase B.
PMID- 10677217
TI - Optical spectroscopic study of the effects of a single deoxyribose substitution
in a ribose backbone: implications in RNA-RNA interaction.
AB - The 2'-OH group in the ribose sugars of an RNA molecule plays an important role
in guiding tertiary interactions that stabilize different RNA structural motifs.
Deoxyribose, or 2'-OH by 2'-H, substitution in both the single-stranded and the
duplex part of an RNA backbone has been routinely used to evaluate what role the
2'-OH plays in different tertiary interactions that guide an RNA-RNA contact. A
deoxyribose substitution not only has the effect of removing a hydrogen bond
donating group, but also introduces a sugar moiety with a preference for C2'-endo
pucker in a backbone of predominantly C3'-endo sugars. This study evaluates the
effects of a single deoxyribose substitution in both single-stranded and double
helical forms of RNA oligomers. A single-stranded, nonrepetitive 7-mer
oligoribonucleotide (7-mer RNA) and four different variants having the same base
sequence but with a single deoxyribose sugar at different positions in the
strands have been studied by ultraviolet (UV) absorption, circular dichroism
(CD), and Fourier transform infrared (FTIR) spectroscopy. Duplexes were formed by
association with the complementary strand of the 7-mer RNA. The results show that
both RNA and DNA single strands have preorganized conformations with spectral
properties resembling those of A- and B-form helices, respectively, with RNA
being more heterogeneous than its DNA counterpart. A single deoxyribose
substitution perturbs the structure of the RNA backbone, with the effect being
more pronounced in the single-stranded than in the duplex structure. The
perturbation depends on the position of the 2'-H substitution in the strand.
PMID- 10677218
TI - Human mitochondrial DNA polymerase holoenzyme: reconstitution and
characterization.
AB - We have reconstituted the holoenzyme of the human mitochondrial DNA polymerase
from cloned and overexpressed catalytic and accessory subunits. We have examined
the polymerization activity of the catalytic subunit alone and of the holoenzyme
to establish the function of the accessory subunit in this two subunit enzyme.
The accessory subunit associates with the catalytic subunit with a dissociation
constant of 35 +/- 16 nM as measured by the concentration dependence of its
effect in stimulating maximal DNA binding and polymerization. At saturating
concentrations, the accessory subunit contributes to every kinetic parameter
examined to facilitate tighter binding of DNA and nucleotide and faster
replication. The accessory protein makes the DNA binding 3.5-fold tighter (K(d)
of 9.9 +/- 2.1 nM compared to 39 +/- 10 nM for the catalytic subunit alone)
without significantly affecting the DNA dissociation rate (0.02 +/- 0.001
compared to 0.03 +/- 0.001 s(-)(1)). The ground-state nucleotide binding is
improved from 4.7 +/- 2.0 to 0.78 +/- 0.065 microM, and the maximum DNA
polymerization rate is increased from 8.7 +/- 1.1 to 45 +/- 1 s(-)(1) by the
addition of the accessory protein. This leads to an increase in processivity from
an estimated 290 +/- 46 to 2250 +/- 162. Although the accessory protein has been
described as a "processivity factor" because of its effect on the ratio of rate
constants defining processivity, this terminology falls short of adequately
describing the profound effects of the small subunit on nucleotide-binding and
incorporation catalyzed by the large subunit. By using the complete holoenzyme,
we can now proceed with a comprehensive analysis of the structural and
mechanistic determinants of enzyme specificity that govern toxicity of nucleoside
analogues used in the treatment of viral infections such as AIDS.
PMID- 10677219
TI - Activation of NF-kappa B and p38 MAP kinase is not sufficient for triggering
efficient HIV gene expression in response to stress.
AB - Recent studies have established an essential role for p38 MAP kinase in UV
activation of human immunodeficiency virus (HIV) gene expression. However, p38
MAP kinase is not involved in activation of NF-kappa B, a key transcriptional
activator of HIV gene expression, in response to UV, suggesting that NF-kappa B
acts independently of p38 MAP kinase. In this study, we have investigated whether
activation of HIV gene expression occurs when p38 MAP kinase and NF-kappa B are
activated by separate stress-causing treatments, each relatively specific for
activating only one of the factors. Treatment of cells with sorbitol
(hyperosmotic shock) strongly activates p38 MAP kinase, whereas the cytokine TNF
alpha is a poor activator of p38 MAP kinase. On the other hand, TNF-alpha is a
strong activator of NF-kappa B whereas sorbitol is not. Sorbitol, however,
activates AP-1 DNA binding activity in a manner similar to that of UV. Most
importantly, both sorbitol and TNF-alpha are poor activators of HIV gene
expression in HeLa cells stably transfected with an HIVcat reporter gene, whereas
UV elicits a strong response. The combined treatment with UV and hyperosmotic
shock produces an additive effect on HIV gene expression, suggesting that these
agents activate at least in part by different mechanisms. The combined treatment
with sorbitol and TNF-alpha activates p38 and NF-kappa B to levels similar to
those with UV, yet only results in 25-30% of the CAT levels elicited by UV.
Inhibition of NF-kappa B activation by the protease inhibitor N-alpha-tosyl-L
phenylalanine chloromethyl ketone (TPCK) prevents UV activation of HIV gene
expression, but does not inhibit p38 MAP kinase activation. We conclude that
whereas both p38 MAP kinase and NF-kappa B are important for UV activation of HIV
gene expression they act independently from each other and activation of both
factors is not sufficient for triggering a full HIV gene expression response.
Activation of HIV gene expression by UV must therefore involve additional
cellular processes, such as those triggered by DNA damage, for generation of a
full gene expression response.
PMID- 10677221
TI - Identity of tRNA for yeast tyrosyl-tRNA synthetase: tyrosylation is more
sensitive to identity nucleotides than to structural features.
AB - The specific aminoacylation of tRNA by yeast tyrosyl-tRNA synthetase does not
rely on the presence of modified residues in tRNA(Tyr), although such residues
stabilize its structure. Thus, the major tyrosine identity determinants were
searched by the in vitro approach using unmodified transcripts produced by T7 RNA
polymerase. On the basis of the tyrosylation efficiency of tRNA variants, the
strongest determinants are base pair C1-G72 and discriminator residue A73 (the 5'
phosphoryl group on C1, however, is unimportant for tyrosylation). The three
anticodon bases G34, U35, and A36 contribute also to the tyrosine identity, but
to a lesser extent, with G34 having the most pronounced effect. Mutation of the
GUA tyrosine anticodon into a CAU methionine anticodon, however, leads to a loss
of tyrosylation efficiency similar to that obtained after mutation of the C1-G72
or A73 determinants. Transplantation of the six determinants into four different
tRNA frameworks and activity assays on heterologous Escherichia coli and
Methanococcus jannaschii tRNA(Tyr) confirmed the completeness of the tyrosine set
and the eukaryotic character of the C1-G72 base pair. On the other hand, it was
found that tyrosine identity in yeast does not rely on fine architectural
features of the tRNA, in particular the size and sequence of the D-loop.
Noticeable, yeast TyrRS efficiently charges a variant of E. coli tRNA(Tyr) with a
large extra-region provided its G1-C72 base pair is changed to a C1-G72 base
pair. Finally, tyrosylation activity is compatible with a +1 shift of the
anticodon in the 3'-direction but is strongly inhibited if this shift occurs in
the opposite 5'-direction.
PMID- 10677220
TI - Catalytic and DNA binding properties of the ogg1 protein of Saccharomyces
cerevisiae: comparison between the wild type and the K241R and K241Q active-site
mutant proteins.
AB - The Ogg1 protein of Saccharomyces cerevisiae belongs to a family of DNA
glycosylases and apurinic/apyrimidinic site (AP) lyases, the signature of which
is the alpha-helix-hairpin-alpha-helix-Gly/Pro-Asp (HhH-GPD) active site motif
together with a conserved catalytic lysine residue, to which we refer as the HhH
GPD/K family. In the yeast Ogg1 protein, yOgg1, the HhH-GPD/K motif spans
residues 225-260 and the conserved lysine is K241. In this study, we have
purified the K241R and K241Q mutant proteins and compared their catalytic and DNA
binding properties to that of the wild-type yOgg1. The results show that the
K241R mutation greatly impairs both the DNA glycosylase and the AP lyase
activities of yOgg1. Specificity constants for cleavage of a 34mer
oligodeoxyribonucleotide containing a 7,8-dihydro-8-oxoguanine (8-OxoG) paired
with a cytosine, [8-OxoG.C], are 56 x 10(-)(3) and 5 x 10(-)(3) min(-)(1) nM(
)(1) for the wild-type and the K241R protein, respectively. On the other hand,
the K241Q mutation abolishes the DNA glycosylase and AP lyase activities of
yOgg1. In contrast, the K241R and K241Q proteins have conserved wild-type DNA
binding properties. K(dapp) values for binding of [8-OxoG.C] are 6.9, 7.4, and
4.8 nM for the wild-type, K241R, and K241Q proteins, respectively. The results
also show that AP site analogues such as 1, 3-propanediol (Pr), tetrahydrofuran
(F), or cyclopentanol (Cy) are not substrates but constitute good inhibitors of
the wild-type yOgg1. Therefore, we have used a 59mer [Pr.C] duplex to further
analyze the DNA binding properties of the wild-type, K241R, and K241Q proteins.
Hydroxyl radical footprints of the wild-type yOgg1 show strong protection of six
nucleotides centered around the Pr lesion in the damaged strand. On the
complementary strand, only the cytosine placed opposite Pr was strongly
protected. The same footprints were observed with the K241R and K241Q proteins,
confirming their wild-type DNA binding properties. These results indicate that
the K241Q mutant protein can be used to study interactions between yOgg1 and DNA
containing metabolizable substrates such as 8-OxoG or an AP site.
PMID- 10677222
TI - Intact aminoacyl-tRNA is required to trigger GTP hydrolysis by elongation factor
Tu on the ribosome.
AB - GTP hydrolysis by elongation factor Tu (EF-Tu) on the ribosome is induced by
codon recognition. The mechanism by which a signal is transmitted from the site
of codon-anticodon interaction in the decoding center of the 30S ribosomal
subunit to the site of EF-Tu binding on the 50S subunit is not known. Here we
examine the role of the tRNA in this process. We have used two RNA fragments, one
which contains the anticodon and D hairpin domains (ACD oligomer) derived from
tRNA(Phe) and the second which comprises the acceptor stem and T hairpin domains
derived from tRNA(Ala) (AST oligomer) that aminoacylates with alanine and forms a
ternary complex with EF-Tu. GTP. While the ACD oligomer and the ternary complex
containing the Ala-AST oligomer interact with the 30S and 50S A site,
respectively, no rapid GTP hydrolysis was observed when both were bound
simultaneously. The presence of paromomycin, an aminoglycoside antibiotic that
binds to the decoding site and stabilizes codon-anticodon interaction in
unfavorable coding situations, did not increase the rate of GTP hydrolysis. These
results suggest that codon recognition as such is not sufficient for GTPase
activation and that an intact tRNA molecule is required for transmitting the
signal created by codon recognition to EF-Tu.
PMID- 10677223
TI - The anticodon-binding domain of tyrosyl-tRNA synthetase: state of folding and
origin of the crystallographic disorder.
AB - The C-terminal domain (residues 320-419) of tyrosyl-tRNA synthetase (TyrRS) from
Bacillus stearothermophilus is disordered in the crystal structure. Its function
consists of binding the anticodon of tRNA(Tyr). We undertook to characterize its
conformational state. A hybrid between the C-terminal fragment and a His-tag
sequence was constructed and purified in large amounts. Analyses by mass
spectrometry and analytical ultracentrifugation showed that the C-terminal
fragment, thus purified, was not degraded and that it neither dimerized nor
aggregated. Its far- and near-UV circular dichroism spectra revealed a high
content in secondary structures and an asymmetrical environment of its aromatic
residues. Each spectrum could be reconstructed by the difference between the
corresponding spectra for the full-length TyrRS and for its N-terminal fragment.
The Stokes radius of the C-terminal fragment, measured by size exclusion
chromatography, indicated a condensed globular state. The fluorescence of ANS (a
small hydrophobic probe) showed that the surface of the C-terminal fragment was
more hydrophilic than that of a molten globule. These results on the C-terminal
fragment and our previous observations that it can undergo cooperative
transitions, demonstrated the following points: it is not in a disordered or
molten globular state, it has a defined and stable three-dimensional structure,
its structures are similar in its isolated and integrated forms, and the apparent
disorder in the crystals of the full-length synthetase must be due to the
flexibility of the polypeptide segment that links the N- and C-terminal domains.
Thus, TyrRS has not evolved strong noncovalent interactions between its catalytic
and anticodon-binding domains, contrary to the other synthetases.
PMID- 10677224
TI - Squalene synthase: steady-state, pre-steady-state, and isotope-trapping studies.
AB - Squalene synthase catalyzes two consecutive reactions in sterol biosynthesis-the
condensation of two molecules of farnesyl diphosphate (FPP) to form the
cyclopropylcarbinyl intermediate presqualene diphosphate (PSPP) and the
subsequent rearrangement and reduction of PSPP to form squalene. Steady-state and
pre-steady-state kinetic studies, in combination with isotope-trapping
experiments of enzyme.substrate complexes, indicate that two molecules of FPP add
to the enzyme before NADPH and that PSPP is converted directly to squalene
without dissociating from the enzyme under normal catalytic conditions. In
addition, formation of PSPP or a prior conformational change in squalene synthase
is the rate-limiting step for synthesis of squalene from FPP via PSPP in the
presence of NADPH and for synthesis of PSPP in the absence of NADPH. Squalene
synthase is inhibited at high concentrations of FPP. Inhibition is specific for
the formation of squalene, but not PSPP, and is competitive with respect to
NADPH. In addition, the binding of either NADPH or a third, nonreacting molecule
of FPP stimulates the rate of PSPP formation. A kinetic mechanism is proposed to
account for these observations.
PMID- 10677225
TI - Identification of the sites of hydroxyl radical reaction with peptides by
hydrogen/deuterium exchange: prevalence of reactions with the side chains.
AB - Hydroxyl radical-effected protium/deuterium ((1)H/(2)H) exchange into the C-H
bonds present in peptides has been used to identify the site of hydrogen atom
abstraction by hydroxyl radical. Radiolysis of anaerobic, N(2)O-saturated D(2)O
solutions containing peptide and dithiothreitol generates a hydroxyl radical that
mediates (1)H/(2)H exchange into the side chains of peptides of up to 66 atom %
excess (2)H. The (1)H/(2)H exchange is determined by measuring the isotope ratio,
[M + H + 1](+)/[M + H](+), of the peptide using electrospray ionization-mass
spectrometry. The (1)H/(2)H exchange within each residue of the peptide was
determined by measuring the isotope ratio of each isolated dansyl amino acid
following hydrolysis and derivatization. Generation of 0.40 mM hydroxyl radical
effected (1)H/(2)H exchange into each of the five different residues of (Ala(2))
leucine enkephalin (YAGFL). The propensity of the residues to undergo exchange
was L > Y > A congruent with F > G, independent of whether they were radiolyzed
separately or as the peptide. The minimal exchange into glycine suggests that
reaction of hydroxyl radical with the side chain hydrogens predominates over
reaction with the polypeptide alpha-hydrogens. The ability of radiolysis to
effect (1)H/(2)H exchange into a larger peptide, SNEQKACKVLGI, was also
demonstrated.
PMID- 10677226
TI - Drug selectivity is determined by coupling across the NAD+ site of IMP
dehydrogenase.
AB - Drug resistance often results from mutations that are located far from the drug
binding site. The effects of these mutations are perplexing. The inhibition of
IMPDH by MPA is an example of this phenomenon. Mycophenolic acid (MPA) is a
species-specific inhibitor of IMPDH; mammalian IMPDHs are very sensitive to MPA,
while the microbial enzymes are resistant to the inhibitor. MPA traps the
covalent intermediate E-XMP and binds in the nicotinamide half of the
dinucleotide site. Previous results indicated that about half of the difference
in sensitivity derives from residues in the MPA-binding site [Digits, J. A., and
Hedstrom, L. (1999) Biochemistry 38, 15388-15397]. The remainder must be
attributed to regions outside the MPA-binding site. The adenosine subsite of the
NAD+ site is not conserved among IMPDHs and is, therefore, a likely candidate.
Our goal is to examine the coupling between the nicotinamide and adenosine sites
in order to test this hypothesis. We performed multiple inhibitor experiments
with the Tritrichomonas foetus and human type 2 IMPDHs using tiazofurin and ADP,
which bind in the nicotinamide and adenosine subsites, respectively. For T.
foetus IMPDH, tiazofurin and ADP are extraordinarily synergistic. In contrast,
these inhibitors are virtually independent for the human type 2 enzyme. We
suggest that the difference in coupling of the nicotinamide and adenosine
subsites accounts for the remaining difference in MPA affinity between T. foetus
and human IMPDH.
PMID- 10677227
TI - The mechanism of orotidine 5'-monophosphate decarboxylase: catalysis by
destabilization of the substrate.
AB - The mechanism of orotidine 5'-monophosphate decarboxylase (OMP decarboxylase,
ODCase) was studied using the decarboxylation of orotic acid analogues as a model
system. The rate of decarboxylation of 1,3-dimethylorotic acid and its analogues
as well as the stability of their corresponding carbanion intermediates was
determined. The results have shown that the stability of the carbanion
intermediate is not a critical factor in the rate of decarboxylation. On the
other hand, the reaction rate is largely dependent on the equilibrium constant
for the formation of a zwitterion. Based on these results, we have proposed a new
mechanism in which ODCase catalyzes the decarboxylation of OMP by binding the
substrate in a zwitterionic form and providing a destabilizing environment for
the carboxylate group of OMP.
PMID- 10677228
TI - Kinetic studies of dimeric Ncd: evidence that Ncd is not processive.
AB - Ncd is a kinesin-related motor protein which drives movement to the minus-end of
microtubules. The kinetics of Ncd were investigated using the dimeric construct
MC1 (Leu(209)-Lys(700)) expressed in Escherichia coli strain BL21(DE) as a
nonfusion protein [Chandra, R., Salmon, E. D., Erickson, H. P., Lockhart, A., and
Endow, S. A. (1993) J. Biol. Chem. 268, 9005-9013]. Acid chemical quench flow
methods were used to measure directly the rate of ATP hydrolysis, and stopped
flow kinetic methods were used to determine the kinetics of mantATP binding,
mantADP release, dissociation of MC1 from the microtubule, and binding of MC1 to
the microtubule. The results define a minimal kinetic mechanism, M.N + ATP
M.N.ATP M.N.ADP.P N. ADP.P N.ADP + P M.N.ADP M.N + ADP, where N, M, and P
represent Ncd, microtubules, and inorganic phosphate respectively, with k(+1) =
2.3 microM(-1) s(-1), k(+2) =23 s(-1), k(+3) =13 s(-1), k(+5)= 0.7 microM(-)(1)
s(-)(1), and k(+6) = 3.7 s(-)(1). Phosphate release (k(+4)) was not measured
directly although it is assumed to be fast relative to ADP release because Ncd is
purified with ADP tightly bound at the active site. ATP hydrolysis occurs at 23
s(-)(1) prior to Ncd dissociation at 13 s(-)(1). The pathway for ATP-promoted
detachment (steps 1-3) of Ncd from the microtubule is comparable to kinesin's.
However, there are two major differences between the mechanisms of Ncd and
kinesin. In contrast to kinesin, mantADP release for Ncd at 3.7 s(-)(1) is the
slowest step in the pathway and is believed to limit steady-state turnover.
Additionally, the burst amplitude observed in the pre-steady-state acid quench
experiments is stoichiometric, indicating that Ncd, in contrast to kinesin, is
not processive for ATP hydrolysis.
PMID- 10677229
TI - Structural transition at actin's N-terminus in the actomyosin cross-bridge cycle.
AB - Force and motion generation by actomyosin involves the cyclic formation and
transition between weakly and strongly bound complexes of these proteins. Actin's
N-terminus is believed to play a greater role in the formation of the weakly
bound actomyosin states than in the formation of the strongly bound actomyosin
states. It has been the goal of this project to determine whether the interaction
of actin's N-terminus with myosin changes upon transition between these two
states. To this end, a yeast actin mutant, Cys-1, was constructed by the
insertion of a cysteine residue at actin's N-terminus and replacement of the C
terminal cysteine with alanine. The N-terminal cysteine was labeled
stoichiometrically with pyrene maleimide, and the properties of the modified
mutant actin were examined prior to spectroscopic measurements. Among these
properties, actin polymerization, strong S1 binding, and the activation of S1
ATPase by pyrenyl-Cys-1 actin were not significantly different from those of wild
type yeast actin, while small changes were observed in the weak S1 binding and
the in vitro motility of actin filaments. Fluorescence changes upon binding of S1
to pyrenyl-Cys-1 actin were measured for the strongly (with or without ADP) and
weakly (with ATP and ATPgammaS) bound acto-S1 states. The fluorescence increased
in each case, but the increase was greater (by about 75%) in the presence of
MgATP and MgATPgammaS than in the rigor state. This demonstrates a transition at
the S1 contact with actin's N-terminus between the weakly and strongly bound
states, and implies either a closer proximity of the pyrene probe on Cys-1 to
structural elements on S1 (most likely the loop of residues 626-647) or greater
S1-induced changes at the N-terminus of actin in the weakly bound acto-S1 states.
PMID- 10677230
TI - Identification of a region at the N-terminus of phospholipase C-beta 3 that
interacts with G protein beta gamma subunits.
AB - Members of the phospholipase C-beta (PLC-beta) family of proteins are activated
either by G alpha or G beta gamma subunits of heterotrimeric G proteins. To
define specific regions of PLC-beta 3 that are involved in binding and activation
by G beta gamma, a series of fragments of PLC-beta 3 as glutathione-S-transferase
(GST) fusion proteins were produced. A fragment encompassing the N-terminal
pleckstrin homology (PH) domain and downstream sequence (GST-N) bound to G
protein beta 1 gamma 2 in an in vitro binding assay, and binding was inhibited by
G protein alpha subunit, G alpha i1. This PLC-beta 3 fragment also inhibited G
beta gamma-stimulated PLC-beta activity in a reconstitution system, while having
no significant effect on G alpha q-stimulated PLC-beta 3 activity. The N-terminal
G beta gamma binding region was delineated further to the first 180 amino acids,
and the sequence Asn150-Ser180, just distal to the PH domain, was found to be
required for the interaction. Mutation of basic residues 154Arg, 155Lys, 159Lys,
and 161Lys to Glu within this region reduced G beta gamma binding affinity and
specifically reduced the EC50 for G beta gamma-dependent activation of the mutant
enzyme 3-fold. Basal activity and G alpha q-dependent activation of the enzyme
were unaffected by the mutations. While these basic residues may not directly
mediate the interaction with G beta gamma, the data provide evidence for an N
terminal G beta gamma binding region of PLC-beta 3 that is involved in activation
of the enzyme.
PMID- 10677231
TI - Bovine NAD+-dependent isocitrate dehydrogenase: alternative splicing and tissue
dependent expression of subunit 1.
AB - NAD+-dependent isocitrate dehydrogenase (IDH), a key regulatory enzyme in the
Krebs cycle, is a multi-tetrameric enzyme. At least three of the subunits in the
core tetramer of mammals are unique gene products. Subunits 1/beta and 2/gamma
are considered to be regulatory, while subunits 3,4/alpha, comprising half the
tetramer, are catalytic. The full sequence was obtained for the major subunit 1
cDNA in bovine heart, IDH 1-A. A second cDNA, rare in heart, was also identified
(IDH 1-B). Differences in the two were confined to the 3'-region, suggesting
alternative splicing. Screening of brain, kidney, and liver RNA showed the
presence of IDH 1-A and 1-B and a third major species, IDH 1-C. Amplification of
bovine genomic DNA by PCR across the regions of difference produced a single
product. Comparison of the genomic and mRNA sequences showed that IDH 1-A
resulted from splicing of exon W to exon Y, eliminating intron w, exon X, and
intron x. IDH 1-B was formed by splice junctions between exon W, exon X, and exon
Y. IDH 1-C resulted from splicing of exon W to exon X and subsequent retention of
intron x. The 2 proteins predicted from these 3 mRNAs are identical over their
first 357 residues. Protein IDH 1-A, resulting from a termination codon within
exon Y, contains an additional 26 residues. Proteins IDH 1-B and 1-C derive from
a common termination codon within exon X and contain an additional 28 residues.
The two C-terminal regions differ notably in the number and nature of charged
residues, resulting in proteins with a charge difference of 3.2 at pH 7.0.
Subunit 1 sequences previously reported from other species grouped with one or
the other of the bovine proteins. No evidence was found for alternative splicing
in subunit 3,4/alpha. The results of the present study, together with recent work
on the 2/gamma subunit [Brenner,V., Nyakatura, G., Rosenthal, A., and Platzer, M.
(1998) Genomics 44, 8], indicate that the regulatory subunits of the enzyme, but
not the catalytic, possess alternatively spliced forms varying in C-terminal
properties with tissue-specific expression. The finding is suggestive of a
mechanism for modulation of allosteric regulation tailored to the needs of
different tissues.
PMID- 10677232
TI - Sodium binding site of factor Xa: role of sodium in the prothrombinase complex.
AB - The nature of residue 225 on a consensus loop in serine proteases determines
whether a protease can bind Na(+). Serine proteases with a Pro at this position
are unable to bind Na(+), but those with a Tyr or Phe can bind Na(+). Factor Xa
(FXa), the serine protease of the prothrombinase complex, contains a Tyr at this
position. Na(+) is also known to stimulate the amidolytic activity of FXa toward
cleavage of small synthetic substrates, but the role of Na(+) in the
prothrombinase complex has not been investigated. In this study, we engineered a
Gla-domainless form of FX (GDFX) in which residue Tyr(225) was replaced with a
Pro. We found that Na(+) stimulated the cleavage rate of chromogenic substrates
by FXa or GDFXa approximately 8-24-fold with apparent dissociation constants
[K(d(app))] of 37 and 182 mM in the presence and absence of Ca(2+), respectively.
In contrast, Na(+) minimally affected the cleavage rate of these substrates by
the mutant, and no K(d(app)) for Na(+) binding to the mutant could be estimated.
Unlike the wild-type enzyme, the reactivity of the mutant with antithrombin was
independent of Na(+) and impaired approximately 32-fold. Ca(2+) improved the
reactivity of the mutant with antithrombin approximately 5-fold. Affinity of the
mutant for binding to factor Va was weakened and its ability to activate
prothrombin was severely impaired. Further studies with the wild-type
prothrombinase complex revealed that FXa binds to factor Va with a similar
K(d(app)) of 1. 1-1.8 nM in the presence of Na(+), K(+), Li(+), Ch(+), and
Tris(+) and that the catalytic efficiency of prothrombinase is enhanced less than
1.5-fold by the specific effect of Na(+) in the reaction buffer. These results
suggest that (1) the loop including residue 225 (225-loop) is a Na(+) binding
site in FXa, (2) the Na(+)- and Ca(2+)-binding loops of FXa are allosterically
linked, and (3) the Tyr conformer of the 225-loop is critical for factor Xa
function; however, both Na(+)-bound and Na(+)-free forms of factor Xa in the
prothrombinase complex can efficiently activate prothrombin.
PMID- 10677233
TI - The polar region consecutive to the HIV fusion peptide participates in membrane
fusion.
AB - The fusion peptide of HIV-1 gp41 is formed by the 16 N-terminal residues of the
protein. This 16-amino acid peptide, in common with several other viral fusion
peptides, caused a reduction in the bilayer to hexagonal phase transition
temperature of dipalmitoleoylphosphatidylethanolamine (T(H)), suggesting its
ability to promote negative curvature in membranes. Surprisingly, an elongated
peptide corresponding to the 33 N-terminal amino acids raised T(H), although it
was more potent than the 16-amino acid fusion peptide in inducing lipid mixing
with large unilamellar liposomes of 1:1:1
dioleoylphosphatidylethanolamine/dioleoylphosphatidylcholine/choleste rol. The 17
amino acid C-terminal fragment of the peptide can induce membrane fusion by
itself, if it is anchored to a membrane by palmitoylation of the amino terminus,
indicating that the additional 17 hydrophilic amino acids contribute to the
fusogenic potency of the peptide. This is not solely a consequence of the
palmitoylation, as a random peptide with the same amino acid composition with a
palmitoyl anchor was less potent in promoting membrane fusion and palmitic acid
itself had no fusogenic activity. The 16-amino acid N-terminal fusion peptide and
the longer 33-amino acid peptide were labeled with NBD. Fluorescence binding
studies indicate that both peptides bind to the membrane with similar affinities,
indicating that the increased fusogenic activity of the longer peptide was not a
consequence of a greater extent of membrane partitioning. We also determined the
secondary structure of the peptides using FTIR spectroscopy. We find that the
amino-terminal fusion peptide is inserted into the membrane as a beta-sheet and
the 17 C-terminal amino acids lie on the surface of the membrane, adopting an
alpha-helical conformation. It was further demonstrated with the use of rhodamine
labeled peptides that the 33-amino acid peptide self-associated in the membrane
while the 16-amino acid N-terminal peptide did not. Thus, the 16-amino acid N
terminal fusion peptide of HIV inserts into the membrane and, like other viral
fusion peptides, lowers T(H). In addition, the 17 consecutive amino acids enhance
the fusogenic activity of the fusion peptide presumably by promoting its self
association.
PMID- 10677234
TI - Changes of intrinsic membrane potentials induced by flip-flop of long-chain fatty
acids.
AB - The passive transbilayer movement-flip-flop-was investigated on planar bilayer
lipid membranes (BLMs), containing myristic, stearic, or linoleic long-chain
fatty acids (FA). In response to a transbilayer pH gradient, a difference in the
surface charges between inner and outer leaflets appeared. Because the BLM was
formed from FA and neutral lipid, a surface potential difference was originated
solely by a concentration difference of the initially equally distributed ionized
FA. As revealed by zeta-potential measurements, the corresponding surface
potential difference DeltaPhi(s) was at least twice the value expected from a
titration of the FA alone. The additional surface charge was attributed to FA
flip-flop induced by the transbilayer pH gradient. DeltaPhi(s) was derived from
capacitive current measurements carried out with a direct current (dc) bias and
was corrected for changes of membrane dipole potential Phi(d). Dual-wavelength
ratiometric fluorescence measurements have shown that Phi(d) values of the pure
DPhPC bilayers and BLMs containing 40 mol % FA differ by less than 6%. It is
concluded that fast FA flip-flop is not restricted to membranes with high
curvature. The role of pH gradient as an effective driving force for the
regulation of FA uptake is discussed.
PMID- 10677235
TI - Mg2+ activates 5-lipoxygenase in vitro: dependency on concentrations of
phosphatidylcholine and arachidonic acid.
AB - Mg2+ gave dose-dependent activation of 5-lipoxygenase (5LO) in vitro. As for
Ca2+, the activation depended on the presence of phosphatidylcholine (PC)
vesicles, and the activation response was different at various combinations of
arachidonate and PC. Stimulation of 5LO activity was observed with Mg2+
concentrations of 0.1-1 mM, similar to the concentration range of free Mg2+ in
mammalian cells. However, to observe a clear increase in 5LO hydrophobicity, a
higher concentration of Mg2+ (4 mM) was required, and at this concentration also
5LO activation was optimal. Combinations of Mg2+ with ATP (containing free Mg2+
and MgATP2- complex) gave better activation of 5LO than either agent alone. This
effect of Mg2+ (and ATP) could be of interest in relation to basal 5LO activity
in cells not subjected to a particular stimulus.
PMID- 10677236
TI - Alpha-ketoacids are potent slow binding inhibitors of the hepatitis C virus NS3
protease.
AB - The replication of the hepatitis C virus (HCV), an important human pathogen,
crucially depends on the proteolytic maturation of a large viral polyprotein
precursor. The viral nonstructural protein 3 (NS3) harbors a serine protease
domain that plays a pivotal role in this process, being responsible for four out
of the five cleavage events that occur in the nonstructural region of the HCV
polyprotein. We here show that hexapeptide, tetrapeptide, and tripeptide alpha
ketoacids are potent, slow binding inhibitors of this enzyme. Their mechanism of
inhibition involves the rapid formation of a noncovalent collision complex in a
diffusion-limited, electrostatically driven association reaction followed by a
slow isomerization step resulting in a very tight complex. pH dependence
experiments point to the protonated catalytic His 57 as an important determinant
for formation of the collision complex. K(i) values of the collision complexes
vary between 3 nM and 18.5 microM and largely depend on contacts made by the
peptide moiety of the inhibitors. Site-directed mutagenesis indicates that Lys
136 selectively participates in stabilization of the tight complex but not of the
collision complex. A significant solvent isotope effect on the isomerization rate
constant is suggestive of a chemical step being rate limiting for tight complex
formation. The potency of these compounds is dominated by their slow dissociation
rate constants, leading to complex half-lives of 11-48 h and overall K(i) values
between 10 pM and 67 nM. The rate constants describing the formation and the
dissociation of the tight complex are relatively independent of the peptide
moiety and appear to predominantly reflect the intrinsic chemical reactivity of
the ketoacid function.
PMID- 10677237
TI - Pressure-induced unfolding/refolding of ribonuclease A: static and kinetic
Fourier transform infrared spectroscopy study.
AB - In this paper, we illustrate the use of high-pressure Fourier transform infrared
(FT-IR) spectroscopy to study the reversible presssure-induced unfolding and
refolding of ribonuclease A (RNase A) and compare it with the results obtained
for the temperature-induced transition. FT-IR spectroscopy monitors changes in
the secondary structural properties (amide I' band) or tertiary contacts
(tyrosine band) of the protein upon pressurization or depressurization. Analysis
of the amide I' spectral components reveals that the pressure-induced
denaturation process sets in at 5. 5 kbar at 20 degrees C and pH 2.5. It is
accompanied by an increase in disordered structures while the content of beta
sheets and alpha-helices drastically decreases. The denatured state above 7 kbar
retains nonetheless some degree of beta-like secondary structure and the molecule
cannot be described as an extended random coil. Increase of pH from 2.5 to 5.5
has no influence on the structure of the pressure-denatured state; it slightly
changes the stability of the protein only. All experimental evidence indicates
that the pressure-denatured states of monomeric proteins have more secondary
structure than the temperature-denatured states. Different modes of denaturation,
including pressure, may correlate differently with the roughness of the energy
scale and slope of the folding funnel. For these reasons we have also carried out
pressure-jump kinetic studies of the secondary structural evolution in the
unfolding/refolding reaction of RNase A. In agreement with the theoretical model
presented by Hummer et al. [(1998) Proc. Natl. Acad. Sci. U.S.A. 95, 1552-1555],
the experimental data show that pressure slows down folding and unfolding
kinetics (here 1-2 orders of magnitude), corresponding to an increasingly rough
landscape. The kinetics remains non-two-state under pressure. Assuming a two-step
folding scenario, the calculated relaxation times for unfolding of RNase A at 20
degrees C and pH 2.5 can be estimated to be tau(1) approximately 0.7 min and
tau(2) approximately 17 min. The refolding process is considerably faster (tau(1)
approximately 0.3 min, tau(2) approximately 4 min). Our data show that the
pressure stability and pressure-induced unfolding/refolding kinetics of monomeric
proteins, such as wild-type staphylococcal nuclease (WT SNase) and RNase A, may
be significantly different. The differences are largely due to the four disulfide
bonds in RNase A, which stabilize adjacent structures. They probably lead to the
much higher denaturation pressure compared to SNase, and this might also explain
why the volume change of WT SNase upon unfolding is about twice as large.
PMID- 10677238
TI - Expression and membrane assembly of a transmembrane region from Neu.
AB - Transmembrane domains of receptor tyrosine kinases are increasingly seen as key
modulatory elements in signaling pathways. The present work addresses problems
surrounding expression, isolation, secondary structure recovery, and assembly
into membranes, of the relatively large quantities of transmembrane peptides
needed to investigate these pathways by NMR spectroscopy. We demonstrate
significant correspondence between SDS-PAGE behavior of such peptides and their
(2)H NMR spectra in lipid bilayer membranes. A 50-residue peptide, Neu(exp),
containing the transmembrane portion of the receptor tyrosine kinase, Neu, was
designed for expression in Escherichia coli. The sequence also contained 11-12
amino acids from each side of the transmembrane domain. The common problem of low
expressivity of transmembrane peptides was encountered-likely associated with
membrane toxicity of the desired gene product. This difficulty was overcome by
expressing the peptide as a TrpE fusion protein in a pATH vector to target
expression products to inclusion bodies, and subsequently removing the TrpE
portion by cyanogen bromide cleavage. Inclusion bodies offered the additional
benefits of reduced proteolytic degradation and simplified purification. The
presence of a hexa-His tag allowed excellent recovery of the final peptide, while
permitting use of denaturing solvents and avoiding the need for HPLC with its
attendant adsorption losses. Isolated expressed peptides were found to be pure,
but existed as high oligomers rich in beta-structure as evidenced by CD
spectroscopy and SDS-PAGE behavior. Dissolution in certain acidic organic
solvents led to material with increased alpha-helix content, which behaved in
detergent as mixtures of predominantly monomers and dimers-a situation often
considered to exist in cell membranes. For purposes of NMR spectroscopy, peptide
alanine residues were deuterated in high yield during expression. The same acidic
organic solvents used to dissolve and dissociate expressed transmembrane peptides
proved invaluable for their assembly into lipid bilayers. Analogous transmembrane
peptides from the human receptor tyrosine kinase, ErbB-2, demonstrated related
phenomena.
PMID- 10677239
TI - Nanosecond dynamics of tryptophans in different conformational states of
apomyoglobin proteins.
AB - Fluorescence anisotropy kinetics were employed to quantify the nanosecond
mobility of tryptophan residues in different conformational states (native,
molten globule, unfolded) of apomyoglobins. Of particular interest is the
similarity between the fluorescence anisotropy decays of tryptophans in the
native and molten globule states. We find that, in these compact states,
tryptophan residues rotate rapidly within a cone of semiangle 22-25 degrees and a
correlation time of 0.5 ns, in addition to rotating together with the whole
protein with a correlation time of 7-11 ns. The similar nanosecond dynamics of
tryptophan residues in both states suggests that the conformation changes that
distinguish the molten globule and native states of apomyoglobins originate from
either subtle, slow rearrangements or fast changes distant from these
tryptophans.
PMID- 10677240
TI - Copper-induced conformational changes in the N-terminal domain of the Wilson
disease copper-transporting ATPase.
AB - The Wilson disease copper-transporting ATPase plays a critical role in the
intracellular trafficking of copper. Mutations in this protein lead to the
accumulation of a toxic level of copper in the liver, kidney, and brain followed
by extensive tissue damage and death. The ATPase has a novel amino-terminal
domain ( approximately 70 kDa) which contains six repeats of the copper binding
motif GMTCXXC. We have expressed and characterized this domain with respect to
the copper binding sites and the conformational consequences of copper binding. A
detailed analysis of this domain by X-ray absorption spectroscopy (XAS) has
revealed that each binding site ligates copper in the +1 oxidation state using
two cysteine side chains with distorted linear geometry. Analysis of copper
induced conformational changes in the amino-terminal domain indicates that both
secondary and tertiary structure changes take place upon copper binding. These
copper-induced conformational changes could play an important role in the
function and regulation of the ATPase in vivo. In addition to providing important
insights on copper binding to the protein, these results suggest a possible
mechanism of copper trafficking by the Wilson disease ATPase.
PMID- 10677241
TI - Treatment of experimental autoimmune encephalomyelitis with adenylate deaminase
from Penicillium lanoso-viride.
AB - The effect of intramuscularly administered immunomodulator, adenylate deaminase
(E.C. 3.5.4.6), from Penicillium lanoso-viride on the clinical score of acute
experimental autoimmune encephalomyelitis (EAE), a T cell-mediated autoimmune
disease, was examined by inoculation of guinea pigs with rabbit brain and spinal
cord homogenate (encephalitogen) and complete Freund's adjuvant. Adenylate
deaminase (ADA) was effective in delaying the onset of clinical disease. ADA
inhibited the severity of EAE. There was a significant decrease in clinical
signs. A decrease in the number of morbid and dead animals was observed. Of ADA
treated animals, 50-80% developed no clinical manifestations of EAE. The optimal
version of treatment was a single preventive injection of ADA 1 day before the
sensitization and then every second day after immunization for 20 days. ADA
treatment of immunized animals diminished the activity of 2', 3'-cyclic
nucleotide 3'-phosphodiesterase in the cerebrospinal fluid, as well the amount of
complement fixing antiencephalitogenic antibodies in the blood serum. The
mechanism of ADA cerebroprotective action is discussed. Significant skin-allergic
cross-reaction of delayed-type hypersensitivity between ADA and encephalitogen
was observed.
PMID- 10677243
TI - Cytotoxic T lymphocyte antigen 4 (CD152) regulates self-reactive T cells in
BALB/c but not in the autoimmune NOD mouse.
AB - Recent studies demonstrated that engagement of cytotoxic T lymphocyte antigen 4
(CTLA-4)/(CD152) generates an inhibitory signal to T cells which arrests an on
going immune response. Since aberrant CD152 activity is thought to contribute to
autoimmunity, we examined the effect of CD152-mediated inhibitory signals on the
response to self and foreign antigens in autoimmune, diabetes-prone NOD and non
autoimmune BALB/c mice. The interaction of CD152 with its ligand B7 was prevented
by treating the mice with anti-CD152 blocking antibody, before and following
immunization of the mice with the self-antigen, syngeneic islet cells, or the
foreign antigen, key-hole limpet hemocyanin (KLH). CD152 blockade in BALB/c mice
stimulated a robust islet-specific T cell-mediated immune response compared to
control antibody-treated mice. The augmentation of T cell responses in BALB/c
mice was consistent with the role proposed for CD152 as a down-regulator of T
cell activation responses. Furthermore, CD152 blockade unmasked islet cell
specific autoreactive T cells in the non-autoimmune BALB/c mouse. Conversely,
CD152 blockade in NOD mice failed to regulate islet-specific auto-reactive T cell
responses. However, CD152 blockade enhanced the T cell response to the exogenous,
foreign antigen KLH in both non-autoimmune BALB/c and autoimmune NOD mice.
Collectively, these results suggest that there is not a global defect in CD152
mediated regulation of peripheral T cell immune responses in NOD autoimmune mice
but rather, a defect specific to T cells recognizing self antigen.
PMID- 10677242
TI - Immunization of low-density lipoprotein receptor deficient (LDL-RD) mice with
heat shock protein 65 (HSP-65) promotes early atherosclerosis.
AB - Heat shock proteins are a family of approximately 25 highly conserved proteins
upregulated in response to various forms of stress. They play an active role in
the development autoimmune diseases in animals, and have been incriminated in
human autoimmune diseases (i.e. rheumatoid arthritis, multiple sclerosis). It has
been previously shown, that an induced immune response against Heat shock protein
65 (HSP-65) results in atherosclerotic lesions in normocholesterolemic rabbits.
We have supported these findings showing that C57BL/6 mice immunized with HSP-65
and fed a high-fat diet develop enhanced fatty streaks. To create a model that
will eliminate the need for exogenous supplementation of a high-fat diet, we have
immunized LDL receptor deficient (LDL-RD) mice with HSP-65 or with heat-killed
Mycobacterium tuberculosis (Mt). Seven groups of LDL-RD mice (n=10), were
immunized subcutaneously with different concentrations of HSP-65, Mt or bovine
serum albumin (BSA). All mice were fed a normal chow-diet for 3 months. The mice
immunized with the higher doses of Mt developed significantly larger fatty
streaks when compared with their BSA immunized littermates. The size of the
lesions in the aortic sinus were: 31,562+/-5,994 microm(2)in the 10 microg Mt and
52,777+/-5,245 microm(2)in the 100 microg Mt vs. 11, 500+/-3,750 microm(2)in the
BSA group (P<0.05). In the HSP-65-immunized mice, only the group injected with
the highest dose (5 microg, twice) developed significantly larger fatty streaks
when compared with the BSA-immunized group (28,611+/-4,716 microm(2)vs. 11,500+/
3,750 microm(2)respectively, (P<0.05). The HSP-65-but not the Mt- or BSA
immunized mice developed high titers of anti HSP-65 antibodies, beginning 10 days
after the immunization, which persisted until they were killed.
Immunohistochemical staining showed CD3-positive lymphocytes in the aortic sinus
of mice immunized with Mt or HSP-65, but not in the control group. Thus, we
established a mouse model of HSP-65 immune mediated atherosclerosis devoid of
high fat diet supplementation. This model will enable us to further study the
role of the immune system in atherosclerosis, via HSP-65 and raise novel
immunomodulatory therapeutic modalities.
PMID- 10677244
TI - Prevention of diabetes in the NOD mouse by a Th1 clone specific for a hsp60
peptide.
AB - Peptide-based therapies have been shown to be effective in the prevention of
diabetes in the NOD mouse. We have been interested in the T cell response
elicited by such therapies and have been studying a T cell clone (C3.5) specific
for hsp60 AA 437-460, generated following immunization with the hsp60 437-460
peptide. The C3.5 clone was CD4(+), Vbeta8.3 TCR(+), I-A(g7)restricted and of the
Th1 type. The injection of this clone into prediabetic NOD mice prevented the
adoptive transfer of the disease and suppressed the development of spontaneous
diabetes. This effect was reflected in a reduction in the degree and severity of
insulitis in mice injected with this clone. In addition, an antibody response was
elicited to the C3.5 clone in mice given multiple injections of the clone. The
epitope recognized by C3.5 is located in the N-terminus of the hsp60 AA 437-460
peptide, and this clone was unable to recognize the native hsp60 molecule. These
data raise questions concerning the mechanism by which peptide-based therapies
prevent autoimmune disease.
PMID- 10677245
TI - Endothelial injury in internal organs of University of California at Davis line
200 (UCD 200) chickens, an animal model for systemic sclerosis (Scleroderma).
AB - Systemic sclerosis (SSc) is a multisystem disorder characterized by mononuclear
cell infiltration and fibrosis. Using skin samples from human SSc and UCD 200
chickens, which spontaneously develop a hereditary disease closely resembling
human SSc, we have shown previously that endothelial cell apoptosis is a primary
event in the pathogenesis of SSc. The aim of the present study was to investigate
the initial disease stage in visceral organs of UCD 200 chickens with special
emphasis on endothelial apoptosis, mononuclear cell infiltration and collagen
deposition using tissue samples from oesophagus, lung, heart, kidney and liver.
Apoptotic endothelial cells were detected by terminal deoxynucleotidyl
transferase-mediated FITC-dUTP nick end labeling (TUNEL), mononuclear cell
infiltrates were stained with hematoxylin and eosin, and increased collagen
deposition was demonstrated by Goldner staining. Apoptotic endothelial cells were
detected in oesophagus, lung and kidney of UCD 200 chickens at the initial stage
of the disease. No apoptotic endothelial cells were found in heart or liver of
UCD 200 or in visceral organs of healthy normal UCD 058 control chickens.
Oesophagus of UCD 200 chickens, which was the most affected internal organ,
showed mononuclear cell infiltrations and increased deposition of collagen.
Perivascular inflammatory infiltrates and collagen deposition appeared later than
endothelial cell apoptosis. These data support the hypothesis that endothelial
cell apoptosis initiates the disease process, followed by mononuclear cell
infiltration and fibrosis.
PMID- 10677246
TI - Treatment of lupus in NZB/W F1 mice with monoclonal antibody against Fas ligand.
AB - Since Fas ligand (FasL) can induce apoptosis of Fas-bearing cells, Fas/FasL
interactions can play a critical role in maintaining self-tolerance. Fas/FasL
interactions in lupus-like autoimmune disease have been well characterized in
studies using either Fas or FasL mutant mice. However, the effect of the
defective FasL-mediated signaling on the establishment of lupus in other mouse
strains, such as NZB/W (B/W) F1, remains uncertain. In the present study, we
examined the effect of anti-FasL monoclonal antibody (mAb) on the development of
lupus. Treatment of B/W F1 mice with anti-FasL mAb augmented IgG1- and IgG2a-type
anti-dsDNA Ab production. However, treatment of B/W F1 mice with anti-FasL mAb
also significantly prevented the development of lupus nephritis. These results
indicate that Fas/FasL interactions not only regulate IgG-type autoantibody
production, but also influence the development of lupus nephritis in B/W F1 mice.
PMID- 10677247
TI - Histone-containing immune complexes are to a large extent responsible for anti
dsDNA reactivity in the Farr assay of active SLE patients.
AB - Increased titres of anti-dsDNA antibodies, especially if of high avidity, are
associated with renal exacerbations in patients with systemic lupus erythematosus
(SLE). One of the most reliable assays to measure anti-dsDNA antibodies, the Farr
assay, is believed to detect preferentially high avidity antibodies. Purified non
complexed monoclonal antibodies (mAbs) against nucleosomes, obtained from mice
with SLE, are not reactive in the Farr assay, but can become so once complexed to
nucleosomes. These Farr-positive, nucleosome containing, immune complexes were
also able to bind in vivo to the glomerular basement membrane (GBM),
predominantly via heparan sulphate (HS). To evaluate whether in SLE patients the
same kind of immune complexes are responsible for Farr reactivity, IgG from serum
or plasma was isolated under dissociating and physiological conditions. We
observed that after purification under dissociating conditions, Farr reactivity
was significantly decreased (P<0.0001) in contrast to reactivity with histones
and two 'control' antigens: Epstein Barr Virus (EBV) and Ro/SS-A. Reactivity with
nucleosomes also decreased after purification, although to a lesser extent.
Plasma purified under physiological conditions showed no decrease in Farr
reactivity. The importance of histones for the generation of immune complexes is
supported by the two following observations. Firstly, the presence of histones
could be demonstrated in serum and plasma of SLE patients but not in serum of
healthy controls or in IgG preparations purified under dissociating conditions.
Secondly, Farr reactivity of purified IgG preparations could be restored by
addition of purified histones. From these studies we conclude that histones
containing immune complexes are responsible for a large part of the Farr
reactivity in active SLE, and are therefore indirectly implicated in the
pathogenesis of lupus nephritis.
PMID- 10677248
TI - A susceptibility locus for human systemic lupus erythematosus (hSLE1) on
chromosome 2q.
AB - To identify chromosomal regions containing susceptibility loci for systemic lupus
erythematosus (SLE), we performed genome scans in families with multiple SLE
patients from Iceland, a geographical and genetic isolate, and from Sweden. A
number of chromosomal regions showed maximum lod scores (Z) indicating possible
linkage to SLE in both the Icelandic and Swedish families. In the Icelandic
families, five regions showed lod scores greater than 2.0, three of which (4p15
13, Z=3.20; 9p22, Z=2.27; 19q13, Z=2.06) are homologous to the murine regions
containing the lmb2, sle2 and sle3 loci, respectively. The fourth region is
located on 19p13 (D19S247, Z=2.58) and the fifth on 2q37 (D2S125, Z=2.06). Only
two regions showed lod scores above 2.0 in the Swedish families: on chromosome
2q11 (D2S436, Z=2. 13) and 2q37 (D2S125, Z=2.18). The combination of both family
sets gave a highly significant lod score at D2S125 of Z=4.24 in favor of linkage
for 2q37. This region represents a new locus for SLE. Our results underscore the
importance of studying well-defined populations for genetic analysis of complex
diseases such as SLE.
PMID- 10677249
TI - Human autoantibodies to a novel Golgi protein golgin-67: high similarity with
golgin-95/gm 130 autoantigen.
AB - Autoantibodies to subcellular organelles have been described in patients with
various systemic rheumatic diseases and our laboratories have been focused on
studies of the Golgi complex as the autoimmune target. We have previously
isolated and described four of the five known Golgi autoantigens reported to
date. During the characterization of Golgi autoantigen golgin-95/gm130, another
human cDNA that shared a significant degree of similarity in both nucleotide and
amino acid sequences was identified. Analysis of cDNAs from different libraries
suggested that this is a distinct gene encoding a protein of 67 kDa which has
four regions with sequence identity to gm130, ranging between 42 and 60%. In this
report, we describe the complete cDNA encoding a closely related Golgi protein
provisionally named golgin-67. Among a group of 84 human anti-Golgi sera, five
(6%) were shown to recognize golgin-67. Anti-golgin-67 human sera and affinity
purified rabbit antibody to the recombinant protein gave predominant Golgi
staining. Golgin-67 is thus the smallest member of a growing family of Golgi
autoantigens rich in alpha-helical coiled-coil domain. The current hypothesis for
the generation of autoimmune antibody to the Golgi complex is discussed.
PMID- 10677250
TI - Latent autoimmune thyroiditis in untreated patients with HCV chronic hepatitis: a
case-control study.
AB - In order to establish a relationship between Hepatitis C virus (HCV) chronic
infection and autoimmune thyroiditis, 97 untreated patients with biopsy-proven
HCV chronic hepatitis and 97 controls were studied. An ultrasound examination of
the thyroid and an assay of serum thyroid-stimulating hormone (TSH), thyroid
hormones and anti-thyroid antibodies were performed in all cases. The overall
prevalence of thyroid abnormalities was higher in patients than in controls (17
vs. 4%, P<0.01) and the prevalence of anti-thyroid antibodies was significantly
different between the two groups (P<0. 02). HCV patients with (n=13) compared to
HCV patients without anti-thyroid antibodies (n=84) were older, predominantly
female, and more frequently had increased serum TSH levels or a hypoechogenic
pattern of the thyroid gland, while Knodell's score and prevalence of cirrhosis
were similar. Latent autoimmune thyroiditis is more frequent in untreated HCV
patients than in controls. This finding raises questions about the mechanism of
autoimmunity induced by HCV and provides an explanation for the high rate of
overt autoimmune thyroiditis during interferon treatment in these patients.
PMID- 10677251
TI - Bilaterian origins: significance of new experimental observations.
AB - Several recent laboratory observations that bear on the origin of the Bilateria
are reviewed and interpreted in light of our set-aside cell theory for bilaterian
origins. We first discuss new data concerning the phylogeny of bilaterian phyla.
Next, we use systematic, molecular, and paleontological lines of evidence to
argue that the latest common ancestor of echinoderms plus hemichordates used a
maximal indirect mode of development. Furthermore, the latest common ancestor of
molluscs and annelids was also indirectly developing. Finally, we discuss new
data on Hox gene expression patterns which suggest that both sea urchins and
polychaete annelids use Hox genes in a very similar fashion. Neither utilizes the
complete Hox complex in the development of the larva per se, while the Hox
complex is expressed in the set-aside cells from which the adult body plan is
formed. Our current views on the ancestry of the bilaterians are summarized in
phylogenetic terms, incorporating the characters discussed in this paper.
PMID- 10677252
TI - Mesenchyme with fgf-10 expression is responsible for regenerative capacity in
Xenopus limb buds.
AB - A young tadpole of an anuran amphibian can completely regenerate an amputated
limb, and it exhibits an ontogenetic decline in the ability to regenerate its
limbs. However, whether mesenchymal or epidermal tissue is responsible for this
decrease of the capacity remains unclear. Moreover, little is known about the
molecular interactions between these two tissues during regeneration. The results
of this study showed that fgf-10 expression in the limb mesenchymal cells clearly
corresponds to the regenerative capacity and that fgf-10 and fgf-8 are
synergistically reexpressed in regenerating blastemas. However, neither fgf-10
nor fgf-8 is reexpressed after amputation of a nonregenerative limb.
Nevertheless, nonregenerative epidermal tissue can reexpress fgf-8 under the
influence of regenerative mesenchyme, as was demonstrated by experiments using a
recombinant limb composed of regenerative limb mesenchyme and nonregenerative
limb epidermis. Taken together, our data demonstrate that the regenerative
capacity depends on mesenchymal tissue and suggest that fgf-10 is likely to be
involved in this capacity.
PMID- 10677253
TI - Sacral neural crest cells colonise aganglionic hindgut in vivo but fail to
compensate for lack of enteric ganglia.
AB - The vagal neural crest is the origin of majority of neurons and glia that
constitute the enteric nervous system, the intrinsic innervation of the gut. We
have recently confirmed that a second region of the neuraxis, the sacral neural
crest, also contributes to the enteric neuronal and glial populations of both the
myenteric and the submucosal plexuses in the chick, caudal to the level of the
umbilicus. Results from this previous study showed that sacral neural crest
derived precursors colonised the gut in significant numbers only 4 days after
vagal-derived cells had completed their migration along the entire length of the
gut. This observation suggested that in order to migrate into the hindgut and
differentiate into enteric neurons and glia, sacral neural crest cells may
require an interaction with vagal-derived cells or with factors or signalling
molecules released by them or their progeny. This interdependence may also
explain the inability of sacral neural crest cells to compensate for the lack of
ganglia in the terminal hindgut of Hirschsprung's disease in humans or
aganglionic megacolon in animals. To investigate the possible interrelationship
between sacral and vagal-derived neural crest cells within the hindgut, we mapped
the contribution of various vagal neural crest regions to the gut and then
ablated appropriate sections of chick vagal neural crest to interrupt the
migration of enteric nervous system precursor cells and thus create an
aganglionic hindgut model in vivo. In these same ablated animals, the sacral
level neural axis was removed and replaced with the equivalent tissue from quail
embryos, thus enabling us to document, using cell-specific antibodies, the
migration and differentiation of sacral crest-derived cells. Results showed that
the vagal neural crest contributed precursors to the enteric nervous system in a
regionalised manner. When quail-chick grafts of the neural tube adjacent to
somites 1-2 were performed, neural crest cells were found in enteric ganglia
throughout the preumbilical gut. These cells were most numerous in the esophagus,
sparse in the preumbilical intestine, and absent in the postumbilical gut. When
similar grafts adjacent to somites 3-5 or 3-6 were carried out, crest cells were
found within enteric ganglia along the entire gut, from the proximal esophagus to
the distal colon. Vagal neural crest grafts adjacent to somites 6-7 showed that
crest cells from this region were distributed along a caudal-rostral gradient,
being most numerous in the hindgut, less so in the intestine, and absent in the
proximal foregut. In order to generate aneural hindgut in vivo, it was necessary
to ablate the vagal neural crest adjacent to somites 3-6, prior to the 13-somite
stage of development. When such ablations were performed, the hindgut, and in
some cases also the cecal region, lacked enteric ganglionated plexuses. Sacral
neural crest grafting in these vagal neural crest ablated chicks showed that
sacral cells migrated along normal, previously described hindgut pathways and
formed isolated ganglia containing neurons and glia at the levels of the
presumptive myenteric and submucosal plexuses. Comparison between vagal neural
crest-ablated and nonablated control animals demonstrated that sacral-derived
cells migrated into the gut and differentiated into neurons in higher numbers in
the ablated animals than in controls. However, the increase in numbers of sacral
neural crest-derived neurons within the hindgut did not appear to be sufficiently
high to compensate for the lack of vagal-derived enteric plexuses, as ganglia
containing sacral neural crest-derived neurons and glia were small and
infrequent. Our findings suggest that the neuronal fate of a relatively fixed
subpopulation of sacral neural crest cells may be predetermined as these cells
neither require the presence of vagal-derived enteric precursors in order to
colonise the hindgut, nor are capable of dramatically altering their
proliferation or d
PMID- 10677254
TI - The Ets domain transcription factor Erm distinguishes rat satellite glia from
Schwann cells and is regulated in satellite cells by neuregulin signaling.
AB - Distinct glial cell types of the vertebrate peripheral nervous system (PNS) are
derived from the neural crest. Here we show that the expression of the Ets domain
transcription factor Erm distinguishes satellite glia from Schwann cells
beginning early in rat PNS development. In developing dorsal root ganglia (DRG),
Erm is present both in presumptive satellite glia and in neurons. In contrast,
Erm is not detectable at any developmental stage in Schwann cells in peripheral
nerves. In addition, Erm is downregulated in DRG-derived glia adopting Schwann
cell traits in culture. Thus, Erm is the first described transcription factor
expressed in satellite glia but not in Schwann cells. In culture, the Neuregulin1
(NRG1) isoform GGF2 maintains Erm expression in presumptive satellite cells and
reinduces Erm expression in DRG-derived glia but not in Schwann cells from
sciatic nerve. These data demonstrate that there are intrinsic differences
between these glial subtypes in their response to NRG1 signaling. In neural crest
cultures, Erm-positive progenitor cells give rise to two distinct glial subtypes:
Erm-positive, Oct-6-negative satellite glia in response to GGF2, and Erm
negative, Oct-6-positive Schwann cells in the presence of serum and the adenylate
cyclase activator forskolin. Thus, Erm-positive neural crest-derived progenitor
cells and presumptive satellite glia are able to acquire Schwann cell features.
Given the in vivo expression of Erm in peripheral ganglia, we suggest that
ganglionic Erm-positive cells may be precursors of Schwann cells.
PMID- 10677255
TI - Anterior endoderm is sufficient to rescue foregut apoptosis and heart tube
morphogenesis in an embryo lacking retinoic acid.
AB - The vitamin A deficient (VAD) quail embryo lacks active retinoids, fails to
express normally GATA-4, and develops a nonlooping heart tube morphogenetic
defect that is a model for congenital cardiomyopathy. VAD quail embryos, or chick
embryos depleted specifically for GATA factors, show in addition abnormal foregut
development, characterized by apoptosis of the endoderm cells associated with
presumptive myocardium during the process of heart tube formation. Exogenous
retinoic acid or transplantation of normal chick embryo anterior endoderm is
sufficient to rescue apoptosis as well as GATA-4 expression and results in normal
development and heart tube morphogenesis. Normal posterior endoderm also contains
retinoids but is unable to rescue the VAD defect. Our results indicate that a
retinoid-dependent transcriptional program, mediated at least in part by GATA
factors, is critical in presumptive foregut endoderm for normal heart tube
morphogenesis.
PMID- 10677256
TI - Smad5 is essential for left-right asymmetry in mice.
AB - Left-right (L-R) asymmetry of the vertebrate body plan is established from an
originally morphologically symmetric embryo. Recent studies have implicated
several TGF-beta family signaling proteins (i.e., nodal, lefty-1, lefty-2,
activin receptor type IIB, and Smad2) in L-R axis determination in the mouse.
However, the genetic pathways underlying L-R patterning are still unclear. Smad5
is a downstream component in the TGF-beta family signaling cascade, and lack of
Smad5 results in embryonic lethality between E9.5 and E11.5. In this report, we
demonstrate that Smad5 mutant embryos have defects in heart looping and embryonic
turning which are the first signs of L-R asymmetry in mice. To gain more insights
into the molecular basis of the laterality defects in the Smad5-deficient
embryos, we examined the expression of lefty-1, lefty-2, nodal, and Pitx2 since
the asymmetric expression of these genes always closely correlates with the
direction of heart looping and embryonic turning. In the absence of Smad5, lefty
1 was expressed at very low or undetectable levels, while nodal, lefty-2, and
Pitx2 were expressed bilaterally. These data suggest that Smad5 is upstream of
lefty-1, nodal, and lefty-2, and as a consequence also of Pitx2, and Smad5 is
essential for L-R axis determination.
PMID- 10677257
TI - Sacral neural crest cell migration to the gut is dependent upon the migratory
environment and not cell-autonomous migratory properties.
AB - Avian neural crest cells from the vagal (somite level 1-7) and the sacral (somite
level 28 and posterior) axial levels migrate into the gut and differentiate into
the neurons and glial cells of the enteric nervous system. Neural crest cells
that emigrate from the cervical and thoracic levels stop short of the dorsal
mesentery and do not enter the gut. In this study we tested the hypothesis that
neural crest cells derived from the sacral level have cell-autonomous migratory
properties that allow them to reach and invade the gut mesenchyme. We
heterotopically grafted neural crest cells from the sacral axial level to the
thoracic level and vice versa and observed that the neural crest cells behaved
according to their new position, rather than their site of origin. Our results
show that the environment at the sacral level is sufficient to allow neural crest
cells from other axial levels to enter the mesentery and gut mesenchyme. Our
study further suggests that at least two environmental conditions at the sacral
level enhance ventral migration. First, sacral neural crest cells take a ventral
rather than a medial-to-lateral path through the somites and consequently arrive
near the gut mesenchyme many hours earlier than their counterparts at the
thoracic level. Our experimental evidence reveals only a narrow window of
opportunity to invade the mesenchyme of the mesentery and the gut, so that
earlier arrival assures the sacral neural crest of gaining access to the gut.
Second, the gut endoderm is more dorsally situated at the sacral level than at
the thoracic level. Thus, sacral neural crest cells take a more direct path to
the gut than the thoracic neural crest, and also their target is closer to the
site from which they initiate migration. In addition, there appears to be a
barrier to migration at the thoracic level that prevents neural crest cells at
that axial level from migrating ventral to the dorsal aorta and into the
mesentery, which is the portal to the gut.
PMID- 10677258
TI - beta-catenin in epithelial morphogenesis: conversion of part of avian foot scales
into feather buds with a mutated beta-catenin.
AB - We explored the role of beta-catenin in chicken skin morphogenesis. Initially
beta-catenin mRNA was expressed at homogeneous levels in the epithelia over a
skin appendage tract field which became transformed into a periodic pattern
corresponding to individual primordia. The importance of periodic patterning was
shown in scaleless mutants, in which beta-catenin was initially expressed
normally, but failed to make a punctuated pattern. To test beta-catenin function,
a truncated armadillo fragment was expressed in developing chicken skin from the
RCAS retrovirus. This produced a variety of phenotypic changes during epithelial
appendage morphogenesis. In apteric and scale-producing regions, new feather buds
with normal-appearing follicle sheaths, dermal papillae, and barb ridges were
induced. In feather tracts, short, wide, and curled feather buds with abnormal
morphology and random orientation formed. Epidermal invaginations and placode
like structures formed in the scale epidermis. PCNA staining and the distribution
of molecular markers (SHH, NCAM, Tenascin-C) were characteristic of feather buds.
These results suggest that the beta-catenin pathway is involved in modulating
epithelial morphogenesis and that increased beta-catenin pathway activity can
increase the activity of skin appendage phenotypes. Analogies between regulated
and deregulated new growths are discussed.
PMID- 10677259
TI - Hydra metalloproteinase 1: a secreted astacin metalloproteinase whose apical axis
expression is differentially regulated during head regeneration.
AB - The newly emerging astacin metalloproteinase family comprises multiple members
with diverse functions. Most recently, the development-related functions have
been attributed to both (1) proteolytic cleavage and subsequent release of active
TGF-beta-like growth factors from latent inhibitory complexes and (2)
modification of extracellular matrix (ECM) assembly and composition. We
previously identified and purified hydra metalloproteinase 1 (HMP-1), a
developmentally important astacin proteinase that functions in head regeneration
and transdifferentiation of tentacle battery cells (L. Yan et al., 1995,
Development 121, 1591-1602). In the present study, further cloning revealed that
HMP-1 is produced as a secreted zymogen with a conserved hydrophobic signal
sequence and a putative propeptide. The processed HMP-1 is composed of a
characteristic astacin proteinase domain and a unique Cys-rich C-terminus. With
this simple domain structure, HMP-1 represents an ancestral astacin proteinase.
Consistent with its role in head regeneration, HMP-1 mRNA is expressed at highest
levels by endodermal cells at the apical pole of the body column just inferior to
the base of tentacles, the region of active cell differentiation or
transdifferentiation. A modified immunocytochemical procedure demonstrated that
HMP-1 protein can be localized not only to ECM of tentacles as we previously
reported, but also to endodermal cells of the body column in a pattern similar to
its mRNA distribution. The localization of HMP-1 protein in tentacles was
confirmed using an enzymatic approach. A translocation of HMP-1 protein from
cells in the body column to the extracellular milieu in tentacles further
suggests that HMP-1 is a secreted protein. HMP-1 expression undergoes extensive
regulation at the transcriptional level both temporally and spatially during head
regeneration. The involvement of HMP-1 in this morphogenetic process is further
supported by the blockage of head regeneration with localized antisense
treatment. Taken together, these results suggest that HMP-1 is a secreted astacin
metalloproteinase that has an important role in regulating hydra head
morphogenesis potentially through its differential expression along the body
axis.
PMID- 10677260
TI - Sequential programs of retinoic acid synthesis in the myocardial and epicardial
layers of the developing avian heart.
AB - Endogenous patterns of retinoic acid (RA) signaling in avian cardiac
morphogenesis were characterized by localized expression of a key RA-synthetic
enzyme, RALDH2, which displayed a biphasic pattern during heart development.
RALDH2 immunoreactivity was initially apparent posterior to Hensen's node of
stage 5-6 embryos and subsequently in somites and unsegmented paraxial and
lateral plate mesoderm overlapping atrial precursors in the cardiogenic plate of
stage 9- embryos. Initial RALDH2 synthesis in the posterior myocardium coincided
with activation of the AMHC1 gene, a RA-responsive marker of inflow heart
segments. A wave of RALDH2 synthesis then swept the myocardium in a posterior-to
anterior direction, reaching the outflow tract by stage 13, then fading from the
myocardial layer. The second phase of RALDH2 expression, initiated at stage 18 in
the proepicardial organ, persisted in migratory epicardial cells that completely
enveloped the heart by stage 24. Early restriction of RALDH2 expression to the
posterior cardiogenic plate, overlapping RA-inducible gene activation, provides
evidence for commitment of posterior avian heart segments by localized production
of RA, whereas subsequent RALDH2 expression exclusively in the migratory
epicardium suggests a role for the morphogen in ventricular expansion and
morphogenesis of underlying myocardial tissues.
PMID- 10677261
TI - The HMG box transcription factor gene Sox14 marks a novel subset of ventral
interneurons and is regulated by sonic hedgehog.
AB - Cell-type diversity along the dorsoventral axis of the developing neural tube is
influenced by factors secreted by groups of cells at the dorsal and ventral
midline. Upon reception of these signals, precursor cells express specific sets
of transcription factors which, in turn, play critical roles in cell-type
specification. Here we report the cloning and characterization of Sox14, a novel
and highly conserved member of the Sry-related Sox transcription factor gene
family, in mouse and chick. Sox14 expression is restricted to a limited
population of neurons in the developing brain and spinal cord of both species.
Sox14 marks a subset of interneurons at a defined dorsoventral position adjacent
to ventral motor neurons in the spinal cord. In vivo grafting of chick notochord
tissue to ectopic positions adjacent to the developing spinal cord altered the
expression domain of Sox14. Furthermore, expression of Sox14 in spinal cord
explants was found to be regulated by Sonic hedgehog in a dose-dependent manner.
These data implicate a novel class of transcription factors in dorsoventral cell
type specification in the spinal cord.
PMID- 10677262
TI - A 130-kDa membrane protein of sperm flagella is the receptor for asterosaps,
sperm-activating peptides of starfish Asterias amurensis.
AB - Spermatozoa of the starfish, Asterias amurensis, have a specific receptor for
asterosap, a sperm-activating peptide isolated from the jelly coat of homologous
eggs. We characterized the receptor by using several asterosap derivatives.
Analysis of equilibrium binding of radioactive di-iodinated Bolton-Hunter reagent
labeled asterosap ((125)I(2)-BHP15) to the spermatozoa indicated that the cell
has 1.1 x 10(5) binding sites of high affinity (K(d) = 57 pM), and also the
receptor showed positive cooperativity for asterosap binding. When spermatozoa
were treated with fluorophore-labeled asterosap, the sperm flagella were labeled,
indicating that the receptors are mostly localized in the sperm tail. When
spermatozoa were reacted with radioactive asterosap prelabeled with photoaffinity
cross-linkers, a single 130-kDa membrane protein of sperm flagella was
specifically radiolabeled. This result was reproducible regardless of the length
of spacer arm of cross-linkers so far studied. Therefore, the 130-kDa protein is
likely to be the receptor for asterosaps. Modification of asterosap at the N
terminal region with bulky molecules such as carboxyfluorescein did not affect
the activity of asterosap, suggesting that the N-terminus of asterosap is not
involved in the ligand-receptor interaction. On the other hand, S-alkylated
asterosaps did not compete with (125)I(2)-BHP15 for binding to the receptor,
indicating that disulfide linkage of asterosap is essential for the ligand
receptor interaction. The properties of the receptor, high affinity and high
concentration, enabled us to apply the fluorescence polarization technique to
study the molecular interaction between asterosap and the receptor. Using this
method, we performed binding experiments in almost real time and found that
divalent cations are significantly involved in the interaction between asterosap
and the receptor.
PMID- 10677263
TI - Development of methods to assess the effects of xenobiotics in outdoor artificial
streams.
AB - Two collaborative research projects were designed to develop and validate methods
for determining the chronic effects of xenobiotics in freshwater ecosystems. The
work reported here focuses on the development of methods for measuring effects on
fish, invertebrates, and algae in outdoor artificial streams. 3,4-Dichloroaniline
(3,4-DCA), has been used as a reference xenobiotic in two artificial stream
experiments. The first used five stream channels: a control and treatments
ranging from 70 to 2400 microg/liter. The second used eight stream channels--a
control and treatments ranging from 0.45 to 4700 microg/liter and four coupled,
510-liter-capacity, downstream ponds-a control and treatments of 1.7, 37, and 820
microg/liter. Effects on the biota of the stream channels and the downstream
ponds were examined using a range of sampling techniques and in situ toxicity
tests.
PMID- 10677264
TI - In vitro cytotoxicity of aromatic aerobic biotransformation products in bluegill
sunfish BF-2 cells.
AB - Toluene (methylbenzene) is a common environmental pollutant that is found in many
hazardous waste sites and it is an aquifer contaminant. A concern is the
potential risk to human and ecosystem health due to exposure to toluene and its
major biotransformation products. The cytotoxicity of eight aromatic products of
toluene aerobic biotransformation was investigated in bluegill sunfish BF-2
cells. The cytotoxicity was determined using several in vitro assay endpoints. BF
2 cells were propagated at 32 degrees C in an atmosphere of 5% CO2-95% air. The
concentrations of these products causing 50% inhibition in cell replication,
protein content, uptake of natural red, and colony formation were evaluated and
compared. The results of the study indicate a direct relationship between the
exposure concentration of these products and observed cytotoxic effects. In
descending order of cytotoxicity, the compounds were 3-methylcatechol, 4
methylcatechol, catechol, o-cresol, p-cresol, m-cresol, benzaldehyde, and methyl
benzoate.
PMID- 10677265
TI - Influence of nitrogen status on the bioconcentration of hydrophobic organic
compounds to Selenastrum capricornutum.
AB - Changes in algal nitrogen status that increase algal lipid content also affect
the bioconcentration of hydrophobic organic compounds (HOCs). Bioconcentration
factors (BCFs) for several HOCs increased up to nine times as the total algal
lipid content of the green algae Selenastrum carpricornutum increased from 17 to
44% of the algal dry weight as a consequence of nitrogen starvation. An increase
in total lipid from 17 to 44% should theoretically increase the BCFs by a factor
of 2.6. BCFs for PCB 31, PCB 49, PCB 153, and DDT increased with maximum lipid
content by factors of 6.3, 8.9, 8.9, and 6.6, respectively, thus more than
theoretically predicted from the lipid normalization of BCFs obtained at
exponential growth phase (17% total lipid for S. carpricornutum), whereas BCFs
for PCB 105, phenanthrene, and 4-chloroaniline increased at 44% lipid content,
only by factors of 1.5, 1.5, and 2.5, respectively, and thus less than or equal
to the theoretical prediction. Lipid-class normalization of BCFs did not reveal
significant information beyond that available from normalizing to total lipid.
PMID- 10677266
TI - Simultaneous geno- and immunotoxicological investigations for early detection of
organophosphate toxicity in rats.
AB - Detectability of toxic effects by repeated doses of dimethoate (DM) and
methylparathion (MPT) were investigated by geno-and immunotoxicological methods
in male Wistar rats following a 28-day oral exposure. In the dose range of 28.2,
14.1, and 7.04, and 7.04 mg/kg/day DM, the two higher doses decreased the body
weight gain. The top dose increased the weight of liver, kidneys, and testicles;
the white blood cell count; and the cell content of the femoral bone marrow. From
immune function parameters measured [IgM-plaque forming cells (PFC) assay,
delayed-type hypersensitivity (DTH) reaction] only the maximum of the DTH
reaction decreased at the top dose. Of the MPT doses (0.872, 0.436, and 0.218
mg/kg/day) the two higher ones increased the liver weight, and a dose-dependent
increase was found in the MCV value. No evaluable changes in the examined immune
function parameters were observed. Both substances increased the number of
numerical but not the structural chromosome aberrations at lower dose levels (the
two larger doses of DM, and all the three doses of MPT) than those ones which
caused changes in the examined immune function parameters. According to these
results, the genotoxicological approach seems to be more sensitive for detection
of repeated-dose oral toxicity of the investigated two organophosphates than the
immunotoxicological one.
PMID- 10677267
TI - Concentration effects of selected insecticides on brain acetylcholinesterase in
the common carp (Cyprinus carpio L.).
AB - The differential inhibition of acetylcholinesterase (AChE) by organophosphate
(OP) and carbamate (C) is followed by the distinct duration of exposure effect on
common carp AChE. Hence, in the present study in vivo exposure period effect and
in vitro concentration-response of chlorfenvinphos, chlorpyrifos diazinon, and
carbofuran were investigated on Cyprinus carpio L. AChE. Individuals of 1-year
old carp were exposed for 96 h to different concentrations of insecticides, after
which AChE activity was measured in the brain. The highest concentrations of
carbofuran (2.44 mg x L(-1)), chlorfenvinphos (2.9 mg x L(-1)), and diazinon (2.5
mg x L(-1)) killed all the test animals after only 4 h, although there was no
statistically significant difference from the control group's brain AChE
activity. The lowest concentration significantly inhibited brain AChE after 96 h.
Chlorfenvinphos was the most potent inhibitor in vivo and chlorpyrifos the least
active inhibitor after 96 h of exposure time. In vitro experimentation with the
same pesticide indicated that several concentrations inhibited 50% of the AChE
activity (I50), ranging from 4.1x10(-7) to 8.12x10(-4) M in both single
inhibitory action and joint inhibitory effect. The results suggest that in
biomonitoring programs carp brain AChE can be a good diagnostic tool for chronic
OP nd C pollution.
PMID- 10677268
TI - Simultaneous action of cypermethrin and two environmental pollutant metals,
cadmium and lead, on bone marrow cell chromosomes of rats in subchronic
administration.
AB - The aim of the present study was to investigate the possible genotoxic effects,
exerted by the pyrethroid cypermethrin and by either of the metals cadmium and
lead alone or in combination, on bone marrow cell chromosomes in a subchronic
experiment. Outbred male Wistar rats were treated per os for 4 weeks in a five
time per week schedule with 5.54, 11.08, or 22.16 mg/kg cypermethrin (1/100,
1/50, 1/25 LD50) alone, or in combination of 1/100 and 1/50 LD50 cypermethrin
with 2.0 mg/kg cadmium chloride or 10 mg/kg lead acetate. On the day following
the last treatment, the animals were sacrificed and bone marrow from the femur
was prepared. Twenty metaphases from 10 animals per group were evaluated. The
evaluation comprised the frequency of aberrant cells, the numerical and
structural aberrations, and the alterations in relative organ weights. In the
dosage used, cypermethrin and cadmium alone caused no significant increase in the
chromosomal aberrations, and lead acetate caused an increase of the numerical
aberrations only. Combination of cypermethrin and cadmium also failed to induce
significant chromosomal effects. The cypermethrin + lead combination, however,
induced a significant increase of structural chromosomal aberrations,
predominantly of all acentric fragments. This lead to the conclusion that the
simultaneous administration of lead and cypermethrin results in an enhanced
genotoxic effect.
PMID- 10677269
TI - Application of quantitative structure--activity relationships for assessing the
aquatic toxicity of phthalate esters.
AB - Phthalate esters (PEs) are an important class of industrial chemicals for which
an extensive aquatic toxicity database is available. The objectives of this study
were to use these data to develop quantitative structure-activity relationships
(QSARs) that describe aquatic toxicity for different freshwater and marine
species, gain insights into toxicity mechanisms, and calculate PE water quality
criteria using statistical extrapolation procedures. Results for low-molecular
weight PEs with log Kow<6 indicate that toxicity data conform to a simple log Kow
dependent QSAR. Fish were found to be more sensitive than algae while
invertebrates spanned a wide range in toxicological response. Freshwater and
marine species demonstrated a similar distribution of sensitivities. Comparison
of species-dependent QSARs supports the hypothesis that biotransformation plays
an important role in explaining toxicity differences observed between species.
Estimated critical body residues (CBRs) for parent PE in fish were in the range
reported for other polar organic chemicals while CBRs for parent PE plus
associated metabolites were in the range reported for nonpolar narcotics (i.e.,
baseline toxicity) suggesting a possible putative role of PE metabolites.
Depending on extrapolation procedure and assumptions, predicted no-effect
concentrations (PNECs) for dimethyl, diethyl, dibutyl, and butybenzyl phthalate
ranged from 3109 to 4780, 865 to 1173, 43 to 62, and 38 to 60 microg l(-1),
respectively. PNECs derived using this approach provide a transparent technical
basis to support aquatic risk assessment for low-molecular-weight PEs. Results
for high-molecular-weight PEs (log Kow>6) indicate that these chemicals are not
acutely or chronically toxic to freshwater or marine organisms due to the
combined role of low water solubility and limited bioconcentration potential
which precludes attainment of internal concentrations that are required to elicit
adverse effects. It is concluded that attempts to establish aquatic PNECs for
high-molecular-weight PEs are not scientifically defensible.
PMID- 10677270
TI - Potential of the insecticides acephate and methamidophos to contaminate
groundwater.
AB - The possible contamination of groundwater by the insecticides acephate and
methamidophos was assessed using the behavior assessment model (BAM) and the
groundwater pollution-potential model (GWP). The dissipation coefficients of the
two insecticides in two soils (Annei silt loam and Pingchen silt clay loam) at
different moisture contents (50 and 100% field capacity) and soil temperatures
(20 and 30 degrees C) were studied by determining the degradation and adsorption
of each insecticide in the soil. The movement of acephate and methamidophos was
studied by leaching each insecticide in a soil column in the laboratory. The
absorption coefficient of methamidophos was much higher than that of acephate in
both types of soil. In the leaching test, methamidophos more easily leached out
from the Pingchen soil column than from the Annei soil column. Methamidophos was
rapidly degraded, with a half-life of 1.11 to 1.61 days in the Annei soil and
7.50 to 13.20 days in the Pingchen soil at different temperatures and soil water
contents. Acephate was found to have a longer half-life than methamidophos in
soil; however, the mobility of methamidophos in both soils was slower than that
of acephate. The mobility of acephate in soil is somewhat faster than that of
methamidophos, and thus acephate may lead to the contamination of groundwater
much more easily than methamidophos under normal conditions.
PMID- 10677271
TI - Sensitivity and significance of luminescent bacteria in chronic toxicity testing
based on growth and bioluminescence.
AB - This study explored the use of luminescent bacteria (Vibrio fischeri) for chronic
aquatic toxicity tests. The evaluated inhibition of growth to Cu2+, Cr6+, Zn2+,
Hg2+, Cd2+, Pb2+, cetyl-trimethylammonium bromide, 3,4-dichloroaniline, acetone,
dimethylsulfoxide, ethanol, nitrobenzene, methanol, and 3,5-dichlorophenol was
compared with results from another investigation, where the inhibition was
determined by bioluminescence. Growth inhibition was found to indicate more
reliably the presence of substances with chronic toxic properties than the loss
of bioluminescence. But growth responded weaker to the majority of the analyzed
toxicants than bioluminescence. This must be connected with the test parameters
and the experimental conditions. But among growth experiments with freshwater
bacteria species the sensitivity of the growth inhibition assay with V. fischeri
is competitive when a poor medium is employed.
PMID- 10677272
TI - Environmental Research Section A.
PMID- 10677273
TI - Tyrosinase kinetics: a semi-quantitative model of the mechanism of oxidation of
monohydric and dihydric phenolic substrates.
AB - A mathematical model of phase I melanogenesis is described based on the
differential reactivity of tyrosinase according to the redox status of the active
site copper atoms shown by Lerch and co-workers (see Lerch, 1981, Metal Ions in
Biological Systems (Sigel, H., ed.) Vol. 13, pp. 143-186. New York: Marcel
Dekker) in combination with the indirect formation of the catecholic intermediate
substrate. In this model the unusual autoactivation kinetics of tyrosinase are
explained by recruitment of enzyme from the met -form, in which the active-site
copper atoms are in the oxidized (Cu(II)) state, by 2-electron donation from
catechol oxidation. Using estimates of the values for the rate constants of the
six reactions involved, the general characteristics of the model are shown to be
consistent with the kinetic behaviour of tyrosinase in vitro. These include a lag
period which is sensitive to catechol addition.
PMID- 10677274
TI - General equilibrium of an ecosystem.
AB - Ecosystems and economies are inextricably linked: ecosystem models and economic
models are not linked. Consequently, using either type of model to design
policies for preserving ecosystems or improving economic performance omits
important information. Improved policies would follow from a model that links the
systems and accounts for the mutual feedbacks by recognizing how key ecosystem
variables influence key economic variables, and vice versa. Because general
equilibrium economic models already are widely used for policy making, the
approach used here is to develop a general equilibrium ecosystem model which
captures salient biological functions and which can be integrated with extant
economic models. In the ecosystem model, each organism is assumed to be a net
energy maximizer that must exert energy to capture biomass from other organisms.
The exerted energies are the "prices" that are paid to biomass, and each organism
takes the prices as signals over which it has no control. The maximization
problem yields the organism's demand for and supply of biomass to other organisms
as functions of the prices. The demands and supplies for each biomass are
aggregated over all organisms in each species which establishes biomass markets
wherein biomass prices are determined. A short-run equilibrium is established
when all organisms are maximizing and demand equals supply in every biomass
market. If a species exhibits positive (negative) net energy in equilibrium, its
population increases (decreases) and a new equilibrium follows. The demand and
supply forces in the biomass markets drive each species toward zero stored energy
and a long-run equilibrium. Population adjustments are not based on typical Lotka
Volterra differential equations in which one entire population adjusts to another
entire population thereby masking organism behavior; instead, individual organism
behavior is central to population adjustments. Numerical simulations use a marine
food web in Alaska to illustrate the model and to show several simultaneous
predator/prey relationships, prey switching by the top predator, and energy flows
through the web.
PMID- 10677275
TI - On optimal size and number of reserves for metapopulation persistence.
AB - Habitat fragmentation is generally considered to be detrimental to the
persistence of natural populations. In nature management, one therefore tends to
prefer few large nature reserves over many small nature reserves having equal
total area. This paper examines whether this preference is warranted in a
metapopulation framework with circular reserves (patches) by formulating the
dependence of metapopulation persistence on the size and number of reserves, both
of which depend on reserve radius if the total area is kept constant. Two
measures of metapopulation persistence are used: R(0), the number of patches
colonized by an occupied patch during its lifetime as an occupied patch, and
T(e), the expected time to extinction. These two measures are functions of the
extinction and colonization rates of the metapopulation. Several mechanisms for
the extinction and colonization processes are formulated from which the
dependence of these rates on reserve radius is calculated. It turns out that
T(e)generally increases with reserve radius for all mechanisms, which supports
the preference of few large reserves. However, R(0)supports this preference only
in the case of some special, rather unrealistic, mechanisms. In many other, more
realistic, cases an intermediate reserve size exists for which metapopulation
persistence measured by R(0)is optimal.
PMID- 10677276
TI - Individual-based perspectives on R(0).
AB - Without doubt the basic reproductive ratio, R(0), is the most widely used
quantity in epidemic theory. Standard compartmental models show how R(0)is
related to the average age of infection, vaccination thresholds for eradication
and equilibrium solutions. However, many of the basic formulae for R(0)break down
when we consider transmission of infection to be a stochastic process involving
discrete individuals. This paper clarifies why and when these differences arise
and predicts when individual-based considerations are likely to be important in
modelling infection dynamics.
PMID- 10677277
TI - A fragment of recombinant GABA(A) receptor alpha1 subunit forming rosette-like
homo-oligomers.
AB - The type A gamma-aminobutyric acid (GABA(A)) receptor plays a major role in
inhibitory synaptic transmission in the central nervous system. A fragment
consisting of residues Cys166 to Leu296 of the alpha1 subunit of the GABA(A)
receptor was overexpressed in Escherichia coli and was found to have stable beta
rich structures. Here, results from laser scattering, gel electrophoresis and
electron microscopy demonstrated that this recombinant protein formed rosette
like homo-oligomers, mainly pentamers in solution. Therefore, the fragment
apparently provides a valuable model system for studying the pentameric
holoreceptor assembly. Non-reducing sodium dodecyl sulfate polyacrylamide gel
electrophoresis of the fragment showed that disulfide bonds formed between
monomers contributed to the oligomerization of the fragment. The fact that this
fragment alone could form pentamers in vitro strongly suggests that amino acid
residues located within the Cys166-Leu296 region of the alpha1 subunit may
contribute to the oligomerization of GABA(A) receptor in vivo.
PMID- 10677278
TI - Ligand-triggered stabilization of vitamin D receptor/retinoid X receptor
heterodimer conformations on DR4-type response elements.
AB - Nuclear receptors integrate an incoming signal in the form of a nuclear hormone
by undergoing a conformational change that results via co-activator proteins in
an activation of the basal transcriptional machinery. The vitamin D(3) receptor
is the nuclear receptor for 1alpha,25-dihydroxyvitamin D(3
)(1alpha,25(OH)(2)D(3)) and is known to function as a heterodimer with the
retinoid X receptor on DR3-type 1alpha,25(OH)(2)D(3) response elements. Here, it
could be demonstrated that DR4-type response elements are at least as effective
as DR3-type 1alpha,25(OH)(2)D(3) response elements. Gel shift clipping analysis
showed that vitamin D(3) receptor-retinoid X receptor heterodimers form in
response to 1alpha, 25(OH)(2)D(3) and retinoid X receptor ligands, the pan
agonist 9-cis retinoic acid (9cRA) and the retinoid X receptor-selective retinoid
CD2425, different conformations on the DR4-type element of the rat Pit-1 gene.
Interestingly, on this response element the heterodimeric complexes of retinoid X
receptor with the thyroid hormone receptor, the retinoic acid receptor and the
benzoate ester receptor also displayed characteristic individual ligand-dependent
complex formation. On the level of complex formation, utilizing DNA affinity and
functional assays, only vitamin D(3) receptor-retinoid X receptor heterodimers
showed a synergistic interaction of both ligands. However, the sensitivity of
vitamin D(3) receptor-retinoid X receptor heterodimers to 1alpha,25(OH)(2)D(3)
was found to be much higher than to retinoid X receptor ligands. Taken together,
this study demonstrates a unique interaction potential of vitamin D(3) receptor
and retinoid X receptor but also establishes DR4-type response elements as multi
functional DNA binding sites with a potential to integrate various hormone
signalling pathways.
PMID- 10677279
TI - IS911 transposition is regulated by protein-protein interactions via a leucine
zipper motif.
AB - Efficient intermolecular transposition of bacterial insertion sequence IS911
involves the activities of two element-encoded proteins: the transposase, OrfAB,
and a regulatory factor, OrfA. OrfA shares the majority of its amino acid
sequence with the N-terminal part of OrfAB. This includes a putative helix-turn
helix and three of four heptads of a leucine zipper motif. OrfA strongly
stimulates OrfAB-mediated intermolecular transposition both in vivo and in vitro.
The present results support the notion that this is accomplished by direct
interaction between these two proteins via the leucine zipper. We used both a
genetic approach, based on gene fusions with phage lambda repressor, and a
physical approach, involving co-immunoprecipitation, to show that OrfA not only
undergoes oligomerisation but is capable of engaging with OrfAB to form
heteromultimers, and that the leucine zipper is necessary for both types of
interaction. Furthermore, mutation of the leucine zipper in OrfA inactivated its
regulatory function. Previous observations demonstrated that the integrity of the
leucine zipper motif was also important for OrfAB binding to the IS911 terminal
inverted repeats. Here, we show, in gel shift experiments, using a derivative of
OrfAB deleted for the C-terminal catalytic domain, OrfAB[1-149], that the protein
is capable of pairing two inverted repeats to generate a species resembling a
"synaptic complex". Preincubation of OrfAB[1-149] with OrfA dramatically reduced
formation of this complex and favored formation of an alternative complex devoid
of OrfA. Together these results suggest that OrfA exerts its regulatory effect by
interacting transiently with OrfAB via the leucine zipper and modifying OrfAB
binding to the inverted repeats.
PMID- 10677280
TI - Mechanisms ensuring rapid and complete DNA replication despite random initiation
in Xenopus early embryos.
AB - Chromosome replication initiates without sequence specificity at average
intervals of approximately 10 kb during the rapid cell cycles of early Xenopus
embryos. If the distribution of origins were random, some inter-origin intervals
would be too long to be fully replicated before the end of S phase. To
investigate what ensures rapid completion of DNA replication, we have examined
the replication intermediates of plasmids of various sizes (5.3-42.2 kbp) in
Xenopus egg extracts by two-dimensional gel electrophoresis and electron
microscopy. We confirm that replication initiates without sequence specificity on
all plasmids. We demonstrate for the first time that multiple initiation events
occur on large plasmids, but not on small (<10 kb) plasmids, at average intervals
of approximately 10 kb. Origin interference may prevent multiple initiation
events on small plasmids. Multiple initiation events are neither synchronous nor
regularly spaced. Bubble density is higher on later than on earlier replication
intermediates, showing that initiation frequency increases throughout S phase,
speeding up replication of late intermediates. We suggest that potential origins
are abundant and randomly distributed, but that the increase of initiation
frequency during S phase, and possibly origin interference, regulate origin
activation to ensure rapid completion of replication.
PMID- 10677281
TI - Conformational flexibility of B-DNA at 0.74 A resolution: d(CCAGTACTGG)(2).
AB - The affinity and specificity of a ligand for its DNA site is a function of the
conformational changes between the isolated and complexed states. Although the
structures of a hydroxypyrrole-imidazole-pyrrole polyamide dimer with 5'
CCAGTACTGG-3' and the trp repressor recognizing the sequence 5'-GTACT-3' are
known, the baseline conformation of the DNA site would contribute to our
understanding of DNA recognition by these ligands. The 0.74 A resolution
structure of a B-DNA double helix, 5'-CCAGTACTGG-3', has been determined by X-ray
crystallography. Six of the nine phosphates, two of four bound calcium ions and
networks of water molecules hydrating the oligonucleotide have alternate
conformations. By contrast, nine of the ten bases have a single, unique
conformation with hydrogen atoms visible in most cases. The polyamide molecules
alter the geometry of the phosphodiester backbone, and the water molecules
mediating contacts in the trp repressor/operator complex are conserved in the
unliganded DNA. Furthermore, the multiple conformational states, ions and
hydration revealed by this ultrahigh resolution structure of a B-form
oligonucleotide are potentially general considerations for understanding DNA
binding affinity and specificity by ligands.
PMID- 10677282
TI - DNA sequence context modulates the impact of a cisplatin 1,2-d(GpG) intrastrand
cross-link on the conformational and thermodynamic properties of duplex DNA.
AB - The anticancer activity of cisplatin derives from its ability to bind and cross
link DNA, with the major adduct being the 1,2-d(GpG) intrastrand cross-link.
Here, the consequences of this adduct on the conformation, thermal stability, and
energetics of duplex DNA are assessed, and the modulation of these parameters by
the sequence context of the adduct is evaluated. The properties of a family of 15
mer DNA duplexes containing a single 1,2-d(GpG) cis-?Pt(NH(3))(2)?(2+)
intrastrand cross-link are probed in different sequence contexts where the
flanking base-pairs are systematically varied from T.A to C.G to A.T. By using a
combination of spectroscopic and calorimetric techniques, the structural,
thermal, and thermodynamic properties of each duplex, both with and without the
cross-link, are characterized. Circular dichroism spectroscopic data reveal that
the cross-link alters the structure of the host duplex in a manner consistent
with a shift from a B-like to an A-like conformation. Thermal denaturation data
reveal that the cross-link induces substantial thermal and thermodynamic
destabilization of the host duplex. Significantly, the magnitudes of these cross
link-induced effects on duplex structure, thermal stability, and energetics are
influenced by the bases that flank the adduct. The presence of flanking A.T base
pairs, relative to T.A or C.G base-pairs, enhances the extent of cross-link
induced alteration to an A-like conformation and dampens the extent of cross-link
induced duplex destabilization. These results are discussed in terms of available
structural data, and in terms of the selective recognition of cisplatin-DNA
adducts by HMG-domain proteins.
PMID- 10677283
TI - Three conformations of an archaeal chaperonin, TF55 from Sulfolobus shibatae.
AB - Chaperonins are cylindrical, oligomeric complexes, essential for viability and
required for the folding of other proteins. The GroE (group I) subfamily, found
in eubacteria, mitochondria and chloroplasts, have 7-fold symmetry and provide an
enclosed chamber for protein subunit folding. The central cavity is transiently
closed by interaction with the co-protein, GroES. The most prominent feature
specific to the group II subfamily, found in archaea and in the eukaryotic
cytosol, is a long insertion in the substrate-binding region. In the archaeal
complex, this forms an extended structure acting as a built-in lid, obviating the
need for a GroES-like co-factor. This extension occludes a site known to bind non
native polypeptides in GroEL. The site and nature of substrate interaction are
not known for the group II subfamily. The atomic structure of the thermosome, an
archaeal group II chaperonin, has been determined in a fully closed form, but the
entry and exit of protein substrates requires transient opening. Although an open
form has been investigated by electron microscopy, conformational changes in
group II chaperonins are not well characterized. Using electron cryo-microscopy
and three-dimensional reconstruction, we describe three conformations of a group
II chaperonin, including an asymmetric, bullet-shaped form, revealing the range
of domain movements in this subfamily.
PMID- 10677284
TI - Sequential determination of ligands binding to discrete components in
heterogeneous mixtures by iterative panning and blocking (IPAB).
AB - Biopanning has been used extensively in conjunction with purified components, but
there are also examples in which mixtures of targets have been investigated. This
study introduces a methodological innovation, termed iterative panning and
blocking (IPAB), to extend the range of specific interactions that can be probed
in mixtures. Here this procedure is used to probe a mixture of high molecular
mass components of human cord blood with phage-peptide display libraries. The
initial panning recovered phage that bore the consensus motif Gly-Pro-Arg-Pro, a
known fibrinogen-binding motif. These phage bound specifically to purified
fibrinogen. A series of peptides containing the Gly-Pro-Arg-Pro motif efficiently
blocked the binding of phage having the same motif, presumably by binding to
their common target. A second round of panning was performed against the same
target mixture in the presence of this blocking peptide. Phage recovered from
this second panning exhibited a motif (Ser-His-Tyr) that was subsequently shown
to bind specifically to complement component C1q. A second peptide containing
this motif specifically blocked the interaction of the phage with C1q. A third
round of panning performed in the presence of both the fibrinogen- and the C1q-
blocking peptides yielded phage with a new peptide motif (Asn-Pro-Phe) that also
bound specifically to C1q, apparently at a new site. The three motifs isolated
through this iterative process were distinct in that each was blocked only by its
corresponding peptide. This IPAB strategy can be applied to many high diversity
selection procedures that target complex mixtures.
PMID- 10677285
TI - Guided selection of a pan carcinoma specific antibody reveals similar binding
characteristics yet structural divergence between the original murine antibody
and its human equivalent.
AB - Antibody engineering provides an excellent tool for the generation of human
immunotherapeutics for the targeted treatment of solid tumours. We have
engineered and selected a completely human antibody to epithelial glycoprotein-2
(EGP-2), a transmembrane glycoprotein present on virtually all human simple
epithelia and abundantly expressed on a variety of human carcinomas. We chose to
use the procedure of "guided selection" to rebuild a high-affinity murine
antibody into a human antibody, using two consecutive rounds of variable domain
shuffling and phage library selection. As a starting antibody, the murine
antibody MOC-31 was used. After the first round of guided selection, where the
V(H) of MOC-31 was combined in Fab format with a human V(L)C(L) library, a small
panel of human light chains was identified, originating from a segment of the
VkappaIII family, whereas the MOC-31 V(L) is more homologous to the VkappaII
family. Nevertheless, one of the chimaeric Fabs, C3, displayed an off-rate
similar to MOC-31 scFv. Combining the V(L) of C3 with a human V(H) library, while
retaining the V(H) CDR3 of MOC-31, clones were selected using human V(H) genes
originating from the rarely used V(H)7 family. The best clone, 9E, shows over 13
amino acid mutations from the germline sequence, has an off-rate comparable to
the original antibody and specifically binds to the "MOC-31"-epitope on EGP-2 in
specificity and competition ELISA, FACS analysis and immunohistochemistry. In
both V(L) and V(H) of antibody 9E, three germline mutations were found creating
the MOC-31 homologue residue. Structural modelling of both murine and human
antibodies reveals that one of the germline mutations, 53Y in V(H) CDR2, is
likely to be involved in antigen binding. We conclude that, although they may
bind the same epitope and have similar binding affinity to the antigen as the
original murine antibody, human antibodies derived by guided selection unlike CDR
grafted antibodies, may retain only some of the original key elements of the
binding site chemistry. The selected human anti-EGP-2 antibody will be a suitable
reagent for tumour targeting.
PMID- 10677286
TI - Solution structure of an 11-mer duplex containing the 3, N(4)-ethenocytosine
adduct opposite 2'-deoxycytidine: implications for the recognition of exocyclic
lesions by DNA glycosylases.
AB - Lipid peroxidation products, as well as the metabolic products of vinyl chloride,
react with cellular DNA producing the mutagenic adduct 3,N(4)-etheno-2'
deoxycytidine (epsilondC), along with several other exocyclic derivatives. High
resolution NMR spectroscopy and restrained molecular dynamics simulations were
used to establish the solution structure of an 11-mer duplex containing an
epsilondC.dC base-pair at its center. The NMR data suggested a regular right
handed helical structure having all residues in the anti orientation around the
glycosydic torsion angle and Watson-Crick alignments for all canonical base-pairs
of the duplex. Restrained molecular dynamics generated a three-dimensional model
in excellent agreement with the spectroscopic data. The (epsilondC. dC)-duplex
structure is a regular right-handed helix with a slight bend at the lesion site
and no severe distortions of the sugar-phosphate backbone. The epsilondC adduct
and its partner dC were displaced towards opposite grooves of the helix,
resulting in a lesion-containing base-pair that was highly sheared but stabilized
to some degree by the formation of a single hydrogen bond. Such a sheared base
pair alignment at the lesion site was previously observed for epsilondC.dG and
epsilondC.T duplexes, and was also present in the crystal structures of duplexes
containing dG.T and dG. U mismatches. These observations suggest the existence of
a substrate structural motif that may be recognized by specific DNA glycosylases
during the process of base excision repair.
PMID- 10677287
TI - Projection structure of a transcriptional regulator, HupR, determined by electron
cryo-microscopy.
AB - Large, well-ordered two-dimensional crystals of the histidine-tagged-HupR
protein, a transcriptional regulator from the photosynthetic bacterium
Rhodobacter capsulatus, were obtained by specific interaction with a Ni(2+)
chelated lipid monolayer. HupR is a response regulator of the NtrC subfamily; it
activates the transcription of the structural genes hupSLC, of [NiFe]hydrogenase.
A projection map of the full-length protein at 9 A resolution was obtained by
electron cryo-microscopy and image analysis of frozen-hydrated two-dimensional
crystals. The crystals have a p6 plane group with unit cell dimensions of
a=b=111.6(+/-1.0) A, gamma=120.4(+/-0.5) degrees. The structure of the N-terminal
domain of NtrC, the family to which HupR belongs, had been determined previously
by NMR. The atomic coordinates of the N-terminal domain of NtrC, were compared to
the structure obtained by cryo-electron microscope techniques of the whole HupR.
These results provide the first structure at medium resolution of a whole
transcription factor, HupR from the NtrC family.
PMID- 10677288
TI - Crystal structure of amylomaltase from thermus aquaticus, a glycosyltransferase
catalysing the production of large cyclic glucans.
AB - Amylomaltase is involved in the metabolism of starch, one of the most important
polysaccharides in nature. A unique feature of amylomaltase is its ability to
catalyze the formation of cyclic amylose. In contrast to the well studied
cyclodextrin glucanotransferases (CGTases), which synthesize cycloamylose with a
ring size (degree of polymerization or DP) of 6-8, the amylomaltase from Thermus
aquaticus produces cycloamyloses with a DP of 22 and higher. The crystal
structure of amylomaltase from Thermus aquaticus was determined to 2.0 A
resolution. It is a member of the alpha-amylase superfamily of enzymes, whose
core structure consists of a (beta, alpha)(8) barrel. In amylomaltase, the 8-fold
symmetry of this barrel is disrupted by several insertions between the barrel
strands. The largest insertions are between the third and fifth barrel strands,
where two insertions form subdomain B1, as well as between the second and third
barrel strands, forming the alpha-helical subdomain B2. Whereas part of subdomain
B1 is also present in other enzyme structures of the alpha-amylase superfamily,
subdomain B2 is unique to amylomaltase. Remarkably, the C-terminal domain C,
which is present in all related enzymes of the alpha-amylase family, is missing
in amylomaltase. Amylomaltase shows a similar arrangement of the catalytic side
chains (two Asp residues and one Glu residue) as in previously characterized
members of the alpha-amylase superfamily, indicating similar mechanisms of the
glycosyl transfer reaction. In amylomaltase, a conserved loop of around eight
amino acid residues is partially shielding the active center. This loop, which is
well conserved among other amylomaltases, may sterically hinder the formation of
small cyclic products.
PMID- 10677289
TI - Binding of equine infectious anemia virus matrix protein to membrane bilayers
involves multiple interactions.
AB - Human immunodeficiency virus (HIV) and equine infectious anemia virus (EIAV) are
closely related lentiviruses that infect immune cells, but their pathogenesis
differ. Localization to the cytosolic leaflet of the plasma membrane is critical
for replication of both viruses. This localization is accomplished through the
matrix (MA) domain of the Gag precursor protein. In HIV-1, association of MA to
anionic membranes appears to be primarily driven by a linear cluster of basic
residues in the MA domain and an N-myristoylation signal. Interestingly, the MA
protein of EIAV does not contain either of these signals. To understand which
factors could promote EIAV assembly we characterized the membrane binding
properties of its MA protein using fluorescence and biochemical methods. We find
that EIAV MA exists as a multimer in solution whose protein-protein interactions
are destabilized by membrane binding. EIAV MA binds strongly to electrically
neutral membranes as well as to negatively charged membranes. Fluorescence
quenching and chemical modification techniques, as well as trypsin proteolysis,
indicate a different exposure of the EIAV MA Trp residues when bound to the two
types of membranes, and EIAV MA proteolysis by trypsin differs when bound to the
two types of membranes. Based on these data and the known structures of closely
related matrix proteins, we constructed a structural model. This model predicts
that EIAV MA binds to negatively charged membranes, but EIAV MA has an additional
membrane binding region rich in residues that partition favorably into the
membrane headgroup region. This secondary site may play a role in early events of
viral infection.
PMID- 10677290
TI - Photocrosslinking of benzophenone-labeled single cysteine troponin I mutants to
other thin filament proteins.
AB - The interaction sites of rabbit skeletal troponin I (TnI) with troponin C (TnC),
troponin T (TnT), tropomyosin (Tm) and actin were mapped systematically using
nine single cysteine residue TnI mutants with mutation sites at positions 6, 48,
64, 89, 104, 121, 133, 155 or 179 (TnI6, TnI48 etc.). Each mutant was labeled
with the heterobifunctional photocrosslinker 4-maleimidobenzophenone (BP-Mal),
and incorporated into the TnI.TnC binary complex, the TnI.TnC.TnT ternary
troponin (Tn) complex, and the Tn.Tm.F-actin synthetic thin filament.
Photocrosslinking reactions carried out in the presence and absence of Ca(2+)
yielded the following results: (1) BP-TnI6 photocrosslinked primarily to TnC with
a small degree of Ca(2+)-dependence in all the complex forms. (2) BP-TnI48, TnI64
and TnI89 photocrosslinked to TnT with no Ca(2+)-dependence. Photocrosslinking to
TnC was reduced in the ternary versus the binary complex. BP-TnI89 also
photocrosslinked to actin with higher yields in the absence of Ca(2+) than in its
presence. (3) BP-TnI104 and TnI133 photocrosslinked to actin with much higher
yields in the absence than in the presence of Ca(2+). (4) BP-TnI121
photocrosslinked to TnC with a small degree of Ca(2+)-dependence, and did not
photocrosslink to actin. (5) BP-TnI155 and TnI179 photocrosslinked to TnC, TnT
and actin, but all with low yields. All the labeled mutants photocrosslinked to
TnC with varying degrees of Ca(2+)-dependence, and none to Tm. These results,
along with those published allowed us to construct a structural and functional
model of TnI in the Tn complex: in the presence of Ca(2+), residues 1-33 of TnI
interact with the C-terminal domain hydrophobic cleft of TnC, approximately 48-89
with TnT, approximately 90-113 with TnC's central helix, approximately 114-125
with TnC's N-terminal domain hydrophobic cleft, and approximately 130-150 with
TnC's A-helix. In the absence of Ca(2+), residues approximately 114-125 move out
of TnC's N-terminal domain hydrophobic cleft and trigger the movements of
residues approximately 89-113 and approximately 130-150 away from TnC and towards
actin.
PMID- 10677291
TI - The GxxxG motif: a framework for transmembrane helix-helix association.
AB - In order to identify strong transmembrane helix packing motifs, we have selected
transmembrane domains exhibiting high-affinity homo-oligomerization from a
randomized sequence library based on the right-handed dimerization motif of
glycophorin A. Sequences were isolated using the TOXCAT system, which measures
transmembrane helix-helix association in the Escherichia coli inner membrane.
Strong selection was applied to a large range of sequences ( approximately 10(7)
possibilities) and resulted in the identification of sequence patterns that
mediate high-affinity helix-helix association. The most frequent motif isolated,
GxxxG, occurs in over 80% of the isolates. Additional correlations suggest that
flanking residues act in concert with the GxxxG motif, and that size
complementarity is maintained at the interface, consistent with the idea that the
identified sequence patterns represent packing motifs. The convergent
identification of similar sequence patterns from an analysis of the transmembrane
domains in the SwissProt sequence database suggests that these packing motifs are
frequently utilized in naturally occurring helical membrane proteins.
PMID- 10677292
TI - Statistical analysis of amino acid patterns in transmembrane helices: the GxxxG
motif occurs frequently and in association with beta-branched residues at
neighboring positions.
AB - To find motifs that mediate helix-helix interactions in membrane proteins, we
have analyzed frequently occurring combinations of residues in a database of
transmembrane domains. Our analysis was performed with a novel formalism, which
we call TMSTAT, for exactly calculating the expectancies of all pairs and
triplets of residues in individual sequences, taking into account differential
sequence composition and the substantial effect of finite length in short
segments. We found that the number of significantly over and under-represented
pairs and triplets was much greater than the random expectation. Isoleucine,
glycine and valine were the most common residues in these extreme cases. The main
theme observed is patterns of small residues (Gly, Ala and Ser) at i and i+4
found in association with large aliphatic residues (Ile, Val and Leu) at
neighboring positions (i.e. i+/-1 and i+/-2). The most over-represented pair is
formed by two glycine residues at i and i+4 (GxxxG, 31.6 % above expectation,
p<1x10(-33)) and it is strongly associated with the neighboring beta-branched
residues Ile and Val. In fact, the GxxxG pair has been described as part of the
strong interaction motif in the glycophorin A transmembrane dimer, in which the
pair is associated with two Val residues (GVxxGV). GxxxG is also the major motif
identified using TOXCAT, an in vivo selection system for transmembrane
oligomerization motifs. In conjunction with these experimental observations, our
results highlight the importance of the GxxxG+beta-branched motif in
transmembrane helix-helix interactions. In addition, the special role for the
beta-branched residues Ile and Val suggested here is consistent with the
hypothesis that residues with constrained rotameric freedom in helical
conformation might reduce the entropic cost of folding in transmembrane proteins.
Additional material is available at http://engelman.csb.yale. edu/tmstat and
http://bioinfo.mbb.yale. edu/tmstat.
PMID- 10677293
TI - Design of nuclease resistant protein kinase calpha DNA enzymes with potential
therapeutic application.
AB - For the therapeutic application of catalytic nucleic acids it is desirable to
have small, stable and inexpensive compounds that are active at physiological
Mg(2+) concentrations. We have explored the possibility of using the versatile 10
23 DNA catalytic core to suppress the expression of the protein kinase Calpha
(PKCalpha) isoform in malignant cells. By introducing either a 3'-3'-inverted
thymidine nucleotide or site-specific phosphorothioate modification into a
PKCalpha DNA enzyme, we have designed stable catalysts that retained a
significant in vitro cleavage activity. In particular, a DNA enzyme containing
phosphorothioate analogues in the antisense arms and in the pyrimidine residues
of the catalytic core was found to be remarkably stable in 50 % human serum
(t(1/2)>90 hours) and inhibited in vitro cell growth by up to 90 % at nanomolar
concentrations. The inhibition of PKCalpha gene expression is sequence-specific,
as a DNA enzyme with reversed antisense arms was found to be ineffective.
Epifluorescence microscopic analysis of cells transfected with a 5' fluorescein
isothiocyanate-conjugated DNA enzyme showed that the DNA enzyme molecules are
mainly localised in the nuclei. Most of the DNA enzyme-treated cells were killed
by apoptosis. The ability of the described PKCalpha DNA enzymes to trigger
apoptosis (apoptozymes) in malignant cells illustrates their therapeutic
potential. Furthermore, such agents can be a valuable tool for probing gene
function.
PMID- 10677294
TI - Methionine adenosyltransferase I/III deficiency: novel mutations and clinical
variations.
AB - Methionine adenosyltransferase (MAT) I/III deficiency, caused by mutations in the
MAT1A gene, is characterized by persistent hypermethioninemia without elevated
homocysteine or tyrosine. Clinical manifestations are variable and poorly
understood, although a number of individuals with homozygous null mutations in
MAT1A have neurological problems, including brain demyelination. We analyzed
MAT1A in seven hypermethioninemic individuals, to provide insight into the
relationship between genotype and phenotype. We identified six novel mutations
and demonstrated that mutations resulting in high plasma methionines may signal
clinical difficulties. Two patients-a compound heterozygote for truncating and
severely inactivating missense mutations and a homozygote for an aberrant
splicing MAT1A mutation-have plasma methionine in the 1,226-1,870 microM range
(normal 5-35 microM) and manifest abnormalities of the brain gray matter or signs
of brain demyelination. Another compound heterozygote for truncating and
inactivating missense mutations has 770-1,240 microM plasma methionine and mild
cognitive impairment. Four individuals carrying either two inactivating missense
mutations or the single-allelic R264H mutation have 105-467 microM plasma
methionine and are clinically unaffected. Our data underscore the necessity of
further studies to firmly establish the relationship between genotypes in MAT
I/III deficiency and clinical phenotypes, to elucidate the molecular bases of
variability in manifestations of MAT1A mutations.
PMID- 10677295
TI - Exon skipping in IVD RNA processing in isovaleric acidemia caused by point
mutations in the coding region of the IVD gene.
AB - Isovaleric acidemia (IVA) is a recessive disorder caused by a deficiency of
isovaleryl-CoA dehydrogenase (IVD). We have reported elsewhere nine point
mutations in the IVD gene in fibroblasts of patients with IVA, which lead to
abnormalities in IVD protein processing and activity. In this report, we describe
eight IVD gene mutations identified in seven IVA patients that result in abnormal
splicing of IVD RNA. Four mutations in the coding region lead to aberrantly
spliced mRNA species in patient fibroblasts. Three of these are amino acid
altering point mutations, whereas one is a single-base insertion that leads to a
shift in the reading frame of the mRNA. Two of the coding mutations strengthen
pre-existing cryptic splice acceptors adjacent to the natural splice junctions
and apparently interfere with exon recognition, resulting in exon skipping. This
mechanism for missplicing has not been reported elsewhere. Four other mutations
alter either the conserved gt or ag dinucleotide splice sites in the IVD gene.
Exon skipping and cryptic splicing were confirmed by transfection of these
mutations into a Cos-7 cell line model splicing system. Several of the mutations
were predicted by individual information analysis to inactivate or significantly
weaken adjacent donor or acceptor sites. The high frequency of splicing mutations
identified in these patients is unusual, as is the finding of missplicing
associated with missense mutations in exons. These results may lead to a better
understanding of the phenotypic complexity of IVA, as well as provide insight
into those factors important in defining intron/exon boundaries in vivo.
PMID- 10677296
TI - Autosomal recessive disorder otospondylomegaepiphyseal dysplasia is associated
with loss-of-function mutations in the COL11A2 gene.
AB - Otospondylomegaepiphyseal dysplasia (OSMED) is an autosomal recessive skeletal
dysplasia accompanied by severe hearing loss. The phenotype overlaps that of the
autosomal dominant disorders-Stickler and Marshall syndromes-but can be
distinguished by disproportionately short limbs, severe hearing loss, and lack of
ocular involvement. In one family with OSMED, a homozygous Gly-->Arg substitution
has been described in COL11A2, which codes for the alpha2 chain of type XI
collagen. We report seven further families with OSMED. All affected individuals
had a remarkably similar phenotype: profound sensorineural hearing loss, skeletal
dysplasia with limb shortening and large epiphyses, cleft palate, an extremely
flat face, hypoplasia of the mandible, a short nose with anteverted nares, and a
flat nasal bridge. We screened affected individuals for mutations in COL11A2 and
found different mutations in each family. Individuals from four families,
including three with consanguineous parents, were homozygous for mutations.
Individuals from three other families, in whom parents were nonconsanguineous,
were compound heterozygous. Of the 10 identified mutations, 9 are predicted to
cause premature termination of translation, and 1 is predicted to cause an in
frame deletion. We conclude that the OSMED phenotype is highly homogenous and
results from homozygosity or compound heterozygosity for COL11A2 mutations, most
of which are predicted to cause complete absence of alpha2(XI) chains.
PMID- 10677297
TI - Mutations in the AIRE gene: effects on subcellular location and transactivation
function of the autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy
protein.
AB - Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a
monogenic autosomal disease with recessive inheritance. It is characterized by
multiple autoimmune endocrinopathies, chronic mucocutaneous candidiasis, and
ectodermal dystrophies. The defective gene responsible for this disease was
recently isolated, and several different mutations in the novel gene, AIRE, have
been identified, by us and by others, in patients with APECED. We have shown that
the APECED protein is mainly localized, both in vitro and in vivo, to the cell
nucleus, where it forms distinct speckles. This accords with the predicted
structural features of the protein, which suggest involvement of AIRE in the
regulation of gene transcription. Here, we report the results of mutational
analyses of a series of 112 patients with APECED who were from various ethnic
backgrounds. A total of 16 different mutations, covering 91% of disease alleles,
were observed; of these, 8 were novel. The mutations are spread throughout the
coding region of AIRE, yet four evident mutational hotspots were observed. In
vitro expression of four different naturally occurring nonsense and missense
mutations revealed a dramatically altered subcellular location of the protein in
cultured cells. Interestingly, the wild-type APECED protein tethered to the Gal4
DNA-binding domain acted as a strong transcriptional activator of reporter genes
in mammalian cells, whereas most of the analyzed mutant polypeptides had lost
this capacity.
PMID- 10677298
TI - Toward a survey of somatic mutation of the NF1 gene in benign neurofibromas of
patients with neurofibromatosis type 1.
AB - Neurofibromatosis type 1 (NF1), a common autosomal dominant disorder caused by
mutations of the NF1 gene, is characterized by multiple neurofibromas,
pigmentation anomalies, and a variety of other possible complications, including
an increased risk of malignant neoplasias. Tumorigenesis in NF1 is believed to
follow the two-hit hypothesis postulated for tumor-suppressor genes. Loss of
heterozygosity (LOH) has been shown to occur in NF1-associated malignancies and
in benign neurofibromas, but only few of the latter yielded a positive result.
Here we describe a systematic approach of searching for somatic inactivation of
the NF1 gene in neurofibromas. In the course of these studies, two new intragenic
polymorphisms of the NF1 gene, a tetranucleotide repeat and a 21-bp duplication,
could be identified. Three tumor-specific point mutations and two LOH events were
detected among seven neurofibromas from four different NF1 patients. Our results
suggest that small subtle mutations occur with similar frequency to that of LOH
in benign neurofibromas and that somatic inactivation of the NF1 gene is a
general event in these tumors. The spectrum of somatic mutations occurring in
various tumors from individual NF1 patients may contribute to the understanding
of variable expressivity of the NF1 phenotype.
PMID- 10677299
TI - Mutational spectrum in the Delta7-sterol reductase gene and genotype-phenotype
correlation in 84 patients with Smith-Lemli-Opitz syndrome.
AB - Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive malformation syndrome,
ranges in clinical severity from mild dysmorphism and moderate mental retardation
to severe congenital malformation and intrauterine lethality. Mutations in the
gene for Delta7-sterol reductase (DHCR7), which catalyzes the final step in
cholesterol biosynthesis in the endoplasmic reticulum (ER), cause SLOS. We have
determined, in 84 patients with clinically and biochemically characterized SLOS
(detection rate 96%), the mutational spectrum in the DHCR7 gene. Forty different
SLOS mutations, some frequent, were identified. On the basis of mutation type and
expression studies in the HEK293-derived cell line tsA-201, we grouped mutations
into four classes: nonsense and splice-site mutations resulting in putative null
alleles, missense mutations in the transmembrane domains (TM), mutations in the
4th cytoplasmic loop (4L), and mutations in the C-terminal ER domain (CT). All
but one of the tested missense mutations reduced protein stability.
Concentrations of the cholesterol precursor 7-dehydrocholesterol and clinical
severity scores correlated with mutation classes. The mildest clinical phenotypes
were associated with TM and CT mutations, and the most severe types were
associated with 0 and 4L mutations. Most homozygotes for null alleles had severe
SLOS; one patient had a moderate phenotype. Homozygosity for 0 mutations in DHCR7
appears compatible with life, suggesting that cholesterol may be synthesized in
the absence of this enzyme or that exogenous sources of cholesterol can be used.
PMID- 10677300
TI - Imprinting effect in premature ovarian failure confined to paternally inherited
fragile X premutations.
AB - Fragile X premutations are considered to be a risk factor for premature ovarian
failure (POF), which is usually defined as menopause at age <40 years. Since
premutations may be inherited from either the mother or the father, we evaluated
the influence of the inheritance pattern on the duration of reproductive life in
female carriers. The occurrence of POF and age at menopause in women with a
paternally inherited fragile X premutation (PIP) were compared to those in women
with a maternally inherited fragile X premutation (MIP). We identified 148 women
in whom the parental origin of the premutation could be determined. In 109 of
these women we were able to establish whether POF had occurred: 82 women had a
PIP, and 27 had a MIP. Twenty-three of the women (28%) with a PIP had POF, versus
only 1 (3.7%) with a MIP (two -tailed Fisher's exact test; P=. 007). Kaplan-Meier
analysis of all 148 premutations showed that the age at menopause was
significantly lower in the women with a PIP than in the woman with a MIP (Breslow
test in Kaplan-Meier analysis; P=.003). Our data strongly suggest that, when POF
occurs in fragile X premutation carriers, a considerable proportion of the
premutations are inherited paternally (parent-of-origin effect). We hypothesize
that this may be owing to a paternal genomic imprinting effect.
PMID- 10677301
TI - Detection of chromosomal aberrations by a whole-genome microsatellite screen.
AB - Chromosomal aberrations are a common cause of multiple anomaly syndromes that
include developmental and growth retardation. Current microscopic techniques are
useful for the detection of such aberrations but have a limit of resolution that
is above the threshold for phenotypic effect. We hypothesized that a genomewide
microsatellite screen could detect chromosomal aberrations that were not detected
by standard cytogenetic techniques in a portion of these individuals. To test
this hypothesis, we performed a genomewide microsatellite screen of patients, by
use of a currently available genetic-marker panel that was originally designed
for meiotic mapping of Mendelian traits. We genotyped approximately 400 markers
on 17 pairs of parents and their children who had normal karyotypes. By using
this approach, we detected and confirmed two cases of segmental aneusomy among 11
children with multiple congenital anomalies. These data demonstrate that a
genomewide microsatellite scan can be used to detect chromosomal aberrations that
are not detected by microscopic techniques.
PMID- 10677302
TI - Assignment of a form of congenital muscular dystrophy with secondary merosin
deficiency to chromosome 1q42.
AB - We have previously reported an autosomal recessive form of congenital muscular
dystrophy, characterized by proximal girdle weakness, generalized muscle
hypertrophy, rigidity of the spine, and contractures of the tendo Achilles, in a
consanguineous family from the United Arab Emirates. Early respiratory failure
resulting from severe diaphragmatic involvement was present. Intellect and the
results of brain imaging were normal. Serum creatine kinase levels were grossly
elevated, and muscle-biopsy samples showed dystrophic changes. The expression of
the laminin-alpha2 chain of merosin was reduced on several fibers, but linkage
analysis excluded the LAMA2 locus on chromosome 6q22-23. Here, we report the
results of genomewide linkage analysis of this family, by use of homozygosity
mapping. In all four affected children, an identical homozygous region was
identified on chromosome 1q42, spanning 6-15 cM between flanking markers D1S2860
and D1S2800. We have identified a second German family with two affected children
having similar clinical and histopathological features; they are consistent with
linkage to the same locus. The cumulative LOD score was 3.57 (straight theta=.00)
at marker D1S213. This represents a novel locus for congenital muscular
dystrophy. We suggest calling this disorder "CMD1B." The expression of three
functional candidate genes in the CMD1B critical region was investigated, and no
detectable changes in their level of expression were observed. The secondary
reduction in laminin-alpha2 chain in these families suggests that the primary
genetic defect resides in a gene coding for a protein involved in basal lamina
assembly.
PMID- 10677303
TI - Familial syndromic esophageal atresia maps to 2p23-p24.
AB - Esophageal atresia (EA) is a common life-threatening congenital anomaly that
occurs in 1/3,000 newborns. Little is known of the genetic factors that underlie
EA. Oculodigitoesophageoduodenal (ODED) syndrome (also known as "Feingold
syndrome") is a rare autosomal dominant disorder with digital abnormalities,
microcephaly, short palpebral fissures, mild learning disability, and
esophageal/duodenal atresia. We studied four pedigrees, including a three
generation Dutch family with 11 affected members. Linkage analysis was initially
aimed at chromosomal regions harboring candidate genes for this disorder. Twelve
different genomic regions covering 15 candidate genes (approximately 15% of the
genome) were excluded from involvement in the ODED syndrome. A subsequent
nondirective mapping approach revealed evidence for linkage between the syndrome
and marker D2S390 (maximum LOD score 4.51 at recombination fraction 0). A
submicroscopic deletion in a fourth family with ODED provided independent
confirmation of this genetic localization and narrowed the critical region to 7.3
cM in the 2p23-p24 region. These results show that haploinsufficiency for a gene
or genes in 2p23-p24 is associated with syndromic EA.
PMID- 10677304
TI - Localization of the gene for a novel autosomal recessive neurodegenerative
Huntington-like disorder to 4p15.3.
AB - A consanguineous family affected by an autosomal recessive, progressive
neurodegenerative Huntington-like disorder, was tested to rule out juvenile-onset
Huntington disease (JHD). The disease manifests at approximately 3-4 years and is
characterized by both pyramidal and extrapyramidal abnormalities, including
chorea, dystonia, ataxia, gait instability, spasticity, seizures, mutism, and
intellectual impairment. Brain magnetic resonance imaging (MRI) findings include
progressive frontal cortical atrophy and bilateral caudate atrophy. Huntington
CAG trinucleotide-repeat analyses ruled out JHD, since all affected individuals
had repeat numbers within the normal range. The presence of only four recombinant
events (straight theta=.2) between the disease and the Huntington locus in 20
informative meioses suggested that the disease localized to chromosome 4. Linkage
was initially achieved with marker D4S2366 at 4p15.3 (LOD 3.03). High-density
mapping at the linked locus resulted in homozygosity for markers D4S431 and
D4S394, which span a 3-cM region. A maximum LOD score of 4.71 in the homozygous
interval was obtained. Heterozygosity at the distal D4S2366 and proximal D4S2983
markers defines the maximum localization interval (7 cM). Multiple brain-related
expressed sequence tags (ESTs) with no known disease association exist in the
linkage interval. Among the three known genes residing in the linked interval
(ACOX3, DRD5, QDPR), the most likely candidate, DRD5, encoding the dopamine
receptor D5, was excluded, since all five affected family members were
heterozygous for an intragenic dinucleotide repeat. The inheritance pattern and
unique localization to 4p15.3 are consistent with the identification of a novel,
autosomal recessive, neurodegenerative Huntington-like disorder.
PMID- 10677305
TI - A new locus for autosomal recessive hypercholesterolemia maps to human chromosome
15q25-q26.
AB - High serum cholesterol is an established risk factor for cardiovascular disease
and is the prime target for therapeutic intervention in large groups of patients.
The development of modern treatments for this major risk factor was propelled by
the early realization that forms of severe hypercholesterolemia could be caused
by dominantly inherited defects in the LDL receptor or in the APOB gene. Further
understanding of the mechanisms contributing to early atherosclerosis will allow
for new targets for therapy. We therefore identified and investigated the
genetics of families from Sardinia that have recessive inheritance of precocious
hypercholesterolemia. We used five families in an analysis of linkage of the
autosomal recessive hypercholesterolemia locus, termed "ARH1," to chromosome
15q25-q26. A genomewide search mapped the disease-causing gene with a LOD score
of 3.3 and excluded major contributions to the phenotype of other genes. A
candidate gene present in the mapped chromosome region-the ligand-activated liver
transcription-factor gene ARP1 (apolipoprotein regulatory-protein gene)-has been
excluded after DNA sequencing. The close-bred nature of the Sardinian population
offers unique opportunities for isolation of this hypercholesterolemia-causing
gene.
PMID- 10677306
TI - X-Linked syndrome of polyendocrinopathy, immune dysfunction, and diarrhea maps to
Xp11.23-Xq13.3.
AB - We describe genetic analysis of a large pedigree with an X-linked syndrome of
polyendocrinopathy, immune dysfunction, and diarrhea (XPID), which frequently
results in death during infancy or childhood. Linkage analysis mapped the XPID
gene to a 17-cM interval defined by markers DXS8083 and DXS8107 on the X
chromosome, at Xp11. 23-Xq13.3. The maximum LOD score was 3.99 (recombination
fraction0) at DXS1235. Because this interval also harbors the gene for Wiskott
Aldrich syndrome (WAS), we investigated mutations in the WASP gene, as the
molecular basis of XPID. Northern blot analysis detected the same relative amount
and the same-sized WASP message in patients with XPID and in a control. Analysis
of the WASP coding sequence, an alternate promoter, and an untranslated upstream
first exon was carried out, and no mutations were found in patients with XPID. A
C-->T transition within the alternate translation start site cosegregated with
the XPID phenotype in this family; however, the same transition site was detected
in a normal control male. We conclude that XPID maps to Xp11.23-Xq13.3 and that
mutations of WASP are not associated with XPID.
PMID- 10677307
TI - A unique form of mental retardation with a distinctive phenotype maps to Xq26
q27.
AB - We report a novel X-linked mental retardation (XLMR) syndrome, with
characteristic facial dysmorphic features, segregating in a large North Carolina
family. Only males are affected, over four generations. Clinical findings in the
seven living affected males include a moderate degree of mental retardation (MR),
coarse facies, puffy eyelids, narrow palpebral fissures, prominent supraorbital
ridges, a bulbous nose, a prominent lower lip, large ears, obesity, and large
testicles. Cephalometric measurements suggest that the affected males have a
distinctive craniofacial skeletal structure, when compared with normative
measures. Obligate-carrier females are unaffected with MR, but the results of
cephalometric skeletal analysis suggest craniofacial dysmorphisms intermediate
between affected males and normative control individuals. Unaffected male
relatives show no clinical or cephalometric resemblance to affected males. The
blood-lymphocyte karyotype and the results of DNA analysis for fragile-X syndrome
and of other routine investigations are normal. Linkage analysis for polymorphic
DNA markers spanning the X chromosome established linkage to Xq26-q27. Maximum
LOD scores were obtained at marker DXS1047 (maximum LOD score = 3.1 at
recombination fraction 0). By use of haplotype analysis, we have localized the
gene for this condition to an 18-cM genetic interval flanked by ATA59C05 and
GATA31E08. On the basis of both the clinical phenotype and the mapping data, we
were able to exclude other reported XLMR conditions. Therefore, we believe that a
unique recessive XLMR syndrome with a distinctive and recognizable phenotype is
represented in this family.
PMID- 10677308
TI - Survey of the fragile X syndrome CGG repeat and the short-tandem-repeat and
single-nucleotide-polymorphism haplotypes in an African American population.
AB - Previous studies have shown that specific short-tandem-repeat (STR) and single
nucleotide-polymorphism (SNP)-based haplotypes within and among unaffected and
fragile X white populations are found to be associated with specific CGG-repeat
patterns. It has been hypothesized that these associations result from different
mutational mechanisms, possibly influenced by the CGG structure and/or cis-acting
factors. Alternatively, haplotype associations may result from the long
mutational history of increasing instability. To understand the basis of the
mutational process, we examined the CGG-repeat size, three flanking STR markers
(DXS548-FRAXAC1-FRAXAC2), and one SNP (ATL1) spanning 150 kb around the CGG
repeat in unaffected (n=637) and fragile X (n=63) African American populations
and compared them with unaffected (n=721) and fragile X (n=102) white
populations. Several important differences were found between the two ethnic
groups. First, in contrast to that seen in the white population, no associations
were observed among the African American intermediate or "predisposed" alleles
(41-60 repeats). Second, two previously undescribed haplotypes accounted for the
majority of the African American fragile X population. Third, a putative
"protective" haplotype was not found among African Americans, whereas it was
found among whites. Fourth, in contrast to that seen in whites, the SNP ATL1 was
in linkage equilibrium among African Americans, and it did not add new
information to the STR haplotypes. These data indicate that the STR- and SNP
based haplotype associations identified in whites probably reflect the mutational
history of the expansion, rather than a mutational mechanism or pathway.
PMID- 10677309
TI - ATM-heterozygous germline mutations contribute to breast cancer-susceptibility.
AB - Approximately 0.5%-1% of the general population has been estimated to be
heterozygous for a germline mutation in the ATM gene. Mutations in the ATM gene
are responsible for the autosomal recessive disorder ataxia-telangiectasia (A-T)
(MIM 208900). The finding that ATM-heterozygotes have an increased relative risk
for breast cancer was supported by some studies but not confirmed by others. In
view of this discrepancy, we examined the frequency of ATM germline mutations in
a selected group of Dutch patients with breast cancer. We have analyzed ATM
germline mutations in normal blood lymphocytes, using the protein-truncation test
followed by genomic-sequence analysis. A high percentage of ATM germline
mutations was demonstrated among patients with sporadic breast cancer. The 82
patients included in this study had developed breast cancer at age <45 and had
survived >/=5 years (mean 15 years), and in 33 (40%) of the patients a
contralateral breast tumor had been diagnosed. Among these patients we identified
seven (8.5%) ATM germline mutations, of which five are distinct. One splice-site
mutation (IVS10-6T-->G) was detected three times in our series. Four heterozygous
carriers were patients with bilateral breast cancer. Our results indicate that
the mutations identified in this study are "A-T disease-causing" mutations that
might be associated with an increased risk of breast cancer in heterozygotes. We
conclude that ATM heterozygotes have an approximately ninefold-increased risk of
developing a type of breast cancer characterized by frequent bilateral
occurrence, early age at onset, and long-term survival. The specific
characteristics of our population of patients may explain why such a high
frequency was not found in other series.
PMID- 10677310
TI - Fine localization of a major disease-susceptibility locus for diffuse
panbronchiolitis.
AB - Diffuse panbronchiolitis affecting East Asians is strongly associated with the
class I human leukocyte antigen (HLA) alleles. Recent observations suggest that a
major disease-susceptibility gene may be located between the HLA-B and HLA-A loci
in the class I region of the major histocompatibility complex on chromosome 6. To
test this possibility, we analyzed 14 polymorphic markers in 92 Japanese patients
and 93 healthy controls. Of these, seven marker alleles, including HLA-B54 and
HLA-A11, were significantly associated with the disease. Maximum-likelihood
haplotype analysis and subsequent direct determination of individual haplotypes
identified a group of disease-associated haplotypes, one of which contained all
seven disease-associated marker alleles. Another haplotype, containing HLA
B*5504, was also associated with the disease. All these haplotypes seem to have
diverged from a common ancestral haplotype in East Asians and share a specific
segment containing three consecutive markers between the S and TFIIH loci in the
class I region. Furthermore, one of the markers within the candidate region
showed the highest delta value, indicating the strongest association. Of 20
Korean patients with diffuse panbronchiolitis, 17 also shared the combination of
the disease-associated marker alleles within the candidate region. These results
indicate that an HLA-associated major susceptibility gene for diffuse
panbronchiolitis is probably located within the 200 kb in the class I region 300
kb telomeric of the HLA-B locus on the chromosome 6p21.3.
PMID- 10677311
TI - Reproducibility and complications in gene searches: linkage on chromosome 6,
heterogeneity, association, and maternal inheritance in juvenile myoclonic
epilepsy.
AB - Evidence for genetic influences in epilepsy is strong, but reports identifying
specific chromosomal origins of those influences conflict. One early study
reported that human leukocyte antigen (HLA) markers were genetically linked to
juvenile myoclonic epilepsy (JME); this was confirmed in a later study. Other
reports did not find linkage to HLA markers. One found evidence of linkage to
markers on chromosome 15, another to markers on chromosome 6, centromeric to HLA.
We identified families through a patient with JME and genotyped markers
throughout chromosome 6. Linkage analysis assuming equal male-female
recombination probabilities showed evidence for linkage (LOD score 2.5), but at a
high recombination fraction (theta), suggesting heterogeneity. When linkage
analysis was redone to allow independent male-female thetas, the LOD score was
significantly higher (4.2) at a male-female theta of.5,.01. Although the overall
pattern of LOD scores with respect to male-female theta could not be explained
solely by heterogeneity, the presence of heterogeneity and predominantly maternal
inheritance of JME might explain it. By analyzing loci between HLA-DP and HLA-DR
and stratifying the families on the basis of evidence for or against linkage, we
were able to show evidence of heterogeneity within JME and to propose a marker
associated with the linked form. These data also suggest that JME may be
predominantly maternally inherited and that the HLA-linked form is more likely to
occur in families of European origin.
PMID- 10677312
TI - Variation in the interleukin 4-receptor alpha gene confers susceptibility to
asthma and atopy in ethnically diverse populations.
AB - After a genomewide screen in the Hutterites was completed, the IL4RA gene was
examined as the 16p-linked susceptibility locus for asthma and atopy. Seven known
variants and one novel variant, representing all nonsynonymous substitutions in
the mature protein, were examined in the Hutterites; on the basis of studies in
the Hutterites, outbred white, black, and Hispanic families were genotyped for
selected markers. All population samples showed evidence of association to atopy
or to asthma (P values.039-.0044 for atopy and. 029-.0000061 for asthma), but the
alleles or haplotypes showing the strongest evidence differed between the groups.
Overall, these data suggest that the IL4RA gene is an atopy- and asthma
susceptibility locus but that variation outside the coding region of the gene
influences susceptibility.
PMID- 10677313
TI - Individual estimates of European genetic admixture associated with lower body
mass index, plasma glucose, and prevalence of type 2 diabetes in Pima Indians.
AB - Individual genetic admixture estimates (IA) from European Americans (EAs) were
computed in 7,996 members of the Gila River Indian Community (Arizona). Parental
populations for the analysis were European Americans and full-heritage Pima
Indians. A logistic regression was performed on 7,796 persons, to assess
association of IA with type 2 diabetes. The odds ratio, comparing diabetes risk
in full-heritage EAs with full-heritage Pima Indians, was 0.329 (95% confidence
interval [CI] 0.225-0.482). Proportional-hazards analysis was performed on 5,482
persons who were nondiabetic at their first examination and 1,215 subjects who
developed diabetes during the study. The hazard risk ratio for IA was 0.455 (95%
CI 0.301-0.688). Nondiabetic persons had significantly more European IA. In
nondiabetic Pimans, multivariate linear regressions of quantitative predictors of
type 2 diabetes mellitus, including fasting plasma glucose, 2-h post-load plasma
glucose, and body-mass index, showed significant inverse relations with IA when
controlled for sex and age. These results illustrate the ongoing evolution of
populations by the mechanism of gene flow and its effect on disease risk in the
groups with admixture. When the two parental populations differ in disease
prevalence, higher or lower risk is associated with admixture, depending on the
origin of the admixed alleles and the relative magnitude of the disease
prevalence in the parental populations. These data also illustrate the strong
genetic components in type 2 diabetes and are consistent with one susceptibility
locus common to obesity and diabetes.
PMID- 10677314
TI - Linkage analyses at the chromosome 1 loci 1q24-25 (HPC1), 1q42.2-43 (PCAP), and
1p36 (CAPB) in families with hereditary prostate cancer.
AB - Recent studies suggest that hereditary prostate cancer (PRCA) is a complex
disease, involving multiple susceptibility genes and variable phenotypic
expression. Through linkage analysis, potential prostate cancer susceptibility
loci have been mapped to 3 regions on chromosome 1. To investigate the reported
linkage to these regions, we conducted linkage studies on 144 PRCA families by
using microsatellite markers in regions 1q24-25 (HPC1) and 1q42.2-43 (PCAP). We
also examined the 1p36 (CAPB) region in 13 PRCA families with at least one case
of brain cancer. No significant evidence of linkage to the HPC1 or PCAP region
was found when the entire data set was analyzed. However, weak evidence for
linkage to HPC1 was observed in the subset of families with male-to-male
transmission (n=102; maximum multipoint nonparametric linkage [NPL] 1.99, P=.03).
Weak evidence for linkage with heterogeneity within this subset was also observed
(HLOD 1.21, P=.02), with approximately 20% of families linked. Although not
statistically significant, suggestive evidence for linkage to PCAP was observed
for the families (n=21) that met the three criteria of male-to-male transmission,
average age of diagnosis <66 years, and >/=5 affected individuals (maximum
multipoint NPL 1.45, P=.08). There was no evidence for linkage to CAPB in the
brain cancer-prostate cancer subset. These results strengthen the argument that
prostate cancer is a heterogeneous disease and that multiple genetic and
environmental factors may be important for its etiology.
PMID- 10677315
TI - Genome screening in human systemic lupus erythematosus: results from a second
Minnesota cohort and combined analyses of 187 sib-pair families.
AB - Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a
loss of immunologic tolerance to a multitude of self-antigens. Epidemiological
data suggest an important role for genes in the etiology of lupus, and previous
genetic studies have implicated the HLA locus, complement genes, and low-affinity
IgG (Fcgamma) receptors in SLE pathogenesis. In an effort to identify new
susceptibility loci for SLE, we recently reported the results of a genomewide
microsatellite marker screen in 105 SLE sib-pair families. By using nonparametric
methods, evidence for linkage was found in four intervals: 6p11-21 (near the
HLA), 16q13, 14q21-23, and 20p12.3 (LOD scores >/=2.0), and weaker evidence in
another nine regions. We now report the results of a second complete genome
screen in a new cohort of 82 SLE sib-pair families. In the cohort 2 screen, the
four best intervals were 7p22 (LOD score 2.87), 7q21 (LOD score 2.40), 10p13 (LOD
score 2.24), and 7q36 (LOD score 2.15). Eight additional intervals were
identified with LOD scores in the range 1.00-1.67. A combined analysis of MN
cohorts 1 and 2 (187 sib-pair families) showed that markers in 6p11-p21 (D6S426,
LOD score 4.19) and 16q13 (D16S415, LOD score 3.85) met the criteria for
significant linkage. Three intervals (2p15, 7q36, and 1q42) had LOD scores in the
range 1.92-2.06, and another 13 intervals had LOD scores in the range of 1.00
1.78 in the combined sample. These data, together with other available gene
mapping results in SLE, are beginning to allow a prioritization of genomic
intervals for gene discovery efforts in human SLE.
PMID- 10677316
TI - Evidence for heterogeneity in recombination in the human pseudoautosomal region:
high resolution analysis by sperm typing and radiation-hybrid mapping.
AB - Accurate genetic and physical maps for the human pseudoautosomal region were
constructed by use of sperm typing and high-resolution radiation-hybrid mapping.
PCR analysis of 1,912 sperm was done with a manual, single-sperm isolation
method. Data on four donors show highly significant linkage heterogeneity among
individuals. The most significant difference was observed in a marker interval
located in the middle of the Xp/Yp pseudoautosomal region, where one donor showed
a particularly high recombination fraction. Longitudinal models were fitted to
the data to test whether linkage heterogeneity among donors was significant for
multiple intervals across the region. The results indicated that increased
recombination in particular individuals and regions is compensated for by reduced
recombination in neighboring intervals. To investigate correspondence between
physical and genetic distances within the region, we constructed a high
resolution radiation-hybrid map containing 29 markers. The recombination fraction
per unit of physical distance varies between regions ranging from 13- to 70-fold
greater than the genome-average rate.
PMID- 10677317
TI - Effects of stratification in the analysis of affected-sib-pair data: benefits and
costs.
AB - The benefits and costs of stratification of affected-sib-pair (ASP) data were
examined in three situations: (1) when there is no difference in identity-by
descent (IBD) allele sharing between stratified and unstratified ASP data sets;
(2) when there is an increase in IBD allele sharing in one of the stratified
groups; and (3) when the data are stratified on the basis of IBD allele-sharing
status at one locus, and the stratified ASPs are then analyzed for linkage at a
second locus. When there is no difference in IBD sharing between strata, a
penalty is always paid for stratifying the data. The loss of power to detect
linkage in the stratified ASP data sets is the result of multiple testing and the
smaller sample size within individual strata. In the case in which etiologic
heterogeneity (i.e., severity of phenotype, age at onset) represents genetic
heterogeneity, the power to detect linkage can be increased by stratifying the
ASP data. This benefit is obtained when there is sufficient IBD allele sharing
and sample sizes. Once linkage has been established for a given locus, data can
be stratified on the basis of IBD status at this locus and can be tested for
linkage at a second locus. When the relative risk is in the vicinity of 1, the
power to detect linkage at the second locus is always greater for the
unstratified ASP data set. Even for values of the relative risk that diverge
sufficiently from 1, with adequate sample sizes and IBD allele sharing, the
benefits of stratifying ASP data are minimal.
PMID- 10677318
TI - Removing the sampling restrictions from family-based tests of association for a
quantitative-trait locus.
AB - One strategy for localization of a quantitative-trait locus (QTL) is to test
whether the distribution of a quantitative trait depends on the number of copies
of a specific genetic-marker allele that an individual possesses. This approach
tests for association between alleles at the marker and the QTL, and it assumes
that association is a consequence of the marker being physically close to the
QTL. However, problems can occur when data are not from a homogeneous population,
since associations can arise irrespective of a genetic marker being in physical
proximity to the QTL-that is, no information is gained regarding localization.
Methods to address this problem have recently been proposed. These proposed
methods use family data for indirect stratification of a population, thereby
removing the effect of associations that are due to unknown population
substructure. They are, however, restricted in terms of the number of children
per family that can be used in the analysis. Here we introduce tests that can be
used on family data with parent and child genotypes, with child genotypes only,
or with a combination of these types of families, without size restrictions.
Furthermore, equations that allow one to determine the sample size needed to
achieve desired power are derived. By means of simulation, we demonstrate that
the existing tests have an elevated false-positive rate when the size
restrictions are not followed and that a good deal of information is lost as a
result of adherence to the size restrictions. Finally, we introduce permutation
procedures that are recommended for small samples but that can also be used for
extensions of the tests to multiallelic markers and to the simultaneous use of
more than one marker.
PMID- 10677319
TI - The relationship between the sibling recurrence-risk ratio and genotype relative
risk.
AB - The recurrence-risk ratio of disease in siblings, lambdaS, is a standard
parameter used in genetic analysis to estimate the statistical power for
detection of a disease locus. However, the relationship between the underlying
risk conferred by a disease-susceptibility allele and lambdaS has not been well
described. The former is generally quantified as a genotype relative risk, gamma,
and measures the ratio of disease risks between those with and those without the
susceptibility genotype(s). We demonstrate that lambdaS varies significantly more
with respect to gamma and the disease-allele frequency for two-locus
multiplicative models than for other two-locus and for single-locus models. For
the single- and two-locus dominant-inheritance models that we studied, when a
disease-susceptibility allele had a frequency >/=.2, lambdaS had an upper limit
of <10. In general, lambdaS values >10 are possible only under recessive
inheritance, dominant inheritance with relatively rare (<5%) disease
susceptibility alleles, or when two or more disease loci have alleles acting
either epistatically or multiplicatively. We introduce the idea of a restricted
sib recurrence-risk ratio (lambda*S) estimated by restriction of sibships to
those ascertained through a proband who already has a putative high-risk allele.
A lambda*S larger than the lambdaS value estimated from randomly selected
probands can serve as an indirect way of testing whether the posited
susceptibility allele increases disease risk. Our results demonstrate that a
lambdaS of 2-3 may portend successful mapping for a variety of genetic models but
that, for some two-locus models, a lambdaS as high as 10 does not guarantee
underlying genes easily mapped by linkage.
PMID- 10677320
TI - Family-based tests of association and linkage that use unaffected sibs,
covariates, and interactions.
AB - We extend the methodology for family-based tests of association and linkage to
allow for both variation in the phenotypes of subjects and incorporation of
covariates into general-score tests of association. We use standard association
models for a phenotype and any number of predictors. We then construct a score
statistic, using likelihoods for the distribution of phenotype, given genotype.
The distribution of the score is computed as a function of offspring genotypes,
conditional on parental genotypes and trait values for offspring and parents.
This approach provides a natural extension of the transmission/disequilibrium
test to any phenotype and to multiple genes or environmental factors and allows
the study of gene-gene and gene-environment interaction. When the trait varies
among subjects or when covariates are included in the association model, the
score statistic depends on one or more nuisance parameters. We suggest two
approaches for obtaining parameter estimates: (1) choosing the estimate that
minimizes the variance of the test statistic and (2) maximizing the statistic
over a nuisance parameter and using a corrected P value. We apply our methods to
a sample of families with attention-deficit/hyperactivity disorder and provide
examples of how covariates and gene-environment and gene-gene interactions can be
incorporated.
PMID- 10677321
TI - A coalescent approach to study linkage disequilibrium between single-nucleotide
polymorphisms.
AB - We present the results of extensive simulations that emulate the development and
distribution of linkage disequilibrium (LD) between single-nucleotide
polymorphisms (SNPs) and a gene locus that is phenotypically stratified into two
classes (disease phenotype and wild-type phenotype). Our approach, based on
coalescence theory, allows an explicit modeling of the demographic history of the
population without conditioning on the age of the mutation, and serves as an
efficient tool to carry out simulations. More specifically, we compare the
influence that a constant population size or an exponentially growing population
has on the amount of LD. These results indicate that attempts to locate single
disease genes are most likely successful in small and constant populations. On
the other hand, if we consider an exponentially growing population that started
to expand from an initially constant population of reasonable size, then our
simulations indicate a lower success rate. The power to detect association is
enhanced if haplotypes constructed from several SNPs are used as markers. The
versatility of the coalescence approach also allows the analysis of other
relevant factors that influence the chances that a disease gene will be located.
We show that several alleles leading to the same disease have no substantial
influence on the amount of LD, as long as the differences between the disease
causing alleles are confined to the same region of the gene locus and as long as
each allele occurs in an appreciable frequency. Our simulations indicate that
mapping of less-frequent diseases is more likely to be successful. Moreover, we
show that successful attempts to map complex diseases depend crucially on the
phenotype-genotype correlations of all alleles at the disease locus. An analysis
of lipoprotein lipase data indicates that our simulations capture the major
features of LD occurring in biological data.
PMID- 10677322
TI - Estimation of variance components of quantitative traits in inbred populations.
AB - Use of variance-component estimation for mapping of quantitative-trait loci in
humans is a subject of great current interest. When only trait values, not
genotypic information, are considered, variance-component estimation can also be
used to estimate heritability of a quantitative trait. Inbred pedigrees present
special challenges for variance-component estimation. First, there are more
variance components to be estimated in the inbred case, even for a relatively
simple model including additive, dominance, and environmental effects. Second,
more identity coefficients need to be calculated from an inbred pedigree in order
to perform the estimation, and these are computationally more difficult to obtain
in the inbred than in the outbred case. As a result, inbreeding effects have
generally been ignored in practice. We describe here the calculation of identity
coefficients and estimation of variance components of quantitative traits in
large inbred pedigrees, using the example of HDL in the Hutterites. We use a
multivariate normal model for the genetic effects, extending the central-limit
theorem of Lange to allow for both inbreeding and dominance under the assumptions
of our variance-component model. We use simulated examples to give an indication
of under what conditions one has the power to detect the additional variance
components and to examine their impact on variance-component estimation. We
discuss the implications for mapping and heritability estimation by use of
variance components in inbred populations.
PMID- 10677323
TI - New estimates of intergenerational time intervals for the calculation of age and
origins of mutations.
AB - Intergenerational time intervals are frequently used in human population-genetics
studies concerned with the ages and origins of mutations. In most cases, mean
intervals of 20 or 25 years are used, regardless of the demographic
characteristics of the population under study. Although these characteristics may
vary from prehistoric to historical times, we suggest that this value is probably
too low, and that the ages of some mutations may have been underestimated.
Analyses were performed by using the BALSAC Population Register (Quebec, Canada),
from which several intergenerational comparisons can be made. Family
reconstitutions were used to measure interval lengths and variations in
descending lineages. Various parameters were considered, such as spouse age at
marriage, parental age, and reproduction levels. Mother-child and father-child
intervals were compared. Intergenerational male and female intervals were also
analyzed in 100 extended ascending genealogies. Results showed that a mean value
of 30 years is a better estimate of intergenerational intervals than 20 or 25
years. As marked differences between male and female interval length were
observed, specific values are proposed for mtDNA, autosomal, X-chromosomal, and Y
chromosomal loci. The applicability of these results for age estimates of
mutations is discussed.
PMID- 10677324
TI - Haplotype fine mapping by evolutionary trees.
AB - To refine the location of a disease gene within the bounds provided by linkage
analysis, many scientists use the pattern of linkage disequilibrium between the
disease allele and alleles at nearby markers. We describe a method that seeks to
refine location by analysis of "disease" and "normal" haplotypes, thereby using
multivariate information about linkage disequilibrium. Under the assumption that
the disease mutation occurs in a specific gap between adjacent markers, the
method first combines parsimony and likelihood to build an evolutionary tree of
disease haplotypes, with each node (haplotype) separated, by a single mutational
or recombinational step, from its parent. If required, latent nodes (unobserved
haplotypes) are incorporated to complete the tree. Once the tree is built, its
likelihood is computed from probabilities of mutation and recombination. When
each gap between adjacent markers is evaluated in this fashion and these results
are combined with prior information, they yield a posterior probability
distribution to guide the search for the disease mutation. We show, by
evolutionary simulations, that an implementation of these methods, called
"FineMap," yields substantial refinement and excellent coverage for the true
location of the disease mutation. Moreover, by analysis of hereditary
hemochromatosis haplotypes, we show that FineMap can be robust to genetic
heterogeneity.
PMID- 10677325
TI - Y chromosomes traveling south: the cohen modal haplotype and the origins of the
Lemba--the "Black Jews of Southern Africa".
AB - The Lemba are a traditionally endogamous group speaking a variety of Bantu
languages who live in a number of locations in southern Africa. They claim
descent from Jews who came to Africa from "Sena." "Sena" is variously identified
by them as Sanaa in Yemen, Judea, Egypt, or Ethiopia. A previous study using Y
chromosome markers suggested both a Bantu and a Semitic contribution to the Lemba
gene pool, a suggestion that is not inconsistent with Lemba oral tradition. To
provide a more detailed picture of the Lemba paternal genetic heritage, we
analyzed 399 Y chromosomes for six microsatellites and six biallelic markers in
six populations (Lemba, Bantu, Yemeni-Hadramaut, Yemeni-Sena, Sephardic Jews, and
Ashkenazic Jews). The high resolution afforded by the markers shows that Lemba Y
chromosomes are clearly divided into Semitic and Bantu clades. Interestingly, one
of the Lemba clans carries, at a very high frequency, a particular Y-chromosome
type termed the "Cohen modal haplotype," which is known to be characteristic of
the paternally inherited Jewish priesthood and is thought, more generally, to be
a potential signature haplotype of Judaic origin. The Bantu Y-chromosome samples
are predominantly (>80%) YAP+ and include a modal haplotype at high frequency.
Assuming a rapid expansion of the eastern Bantu, we used variation in
microsatellite alleles in YAP+ sY81-G Bantu Y chromosomes to calculate a rough
date, 3,000-5,000 years before the present, for the start of their expansion.
PMID- 10677326
TI - The X chromosome frequently lags behind in female lymphocyte anaphase.
AB - Pancentromeric FISH and X-chromosome painting were used to characterize anaphase
aberrations in 2,048 cultured lymphocytes from a healthy 62-year-old woman. Of
163 aberrant anaphases, 66.9% contained either chromosomes or their fragments
that lagged behind. Characterization of 200 laggards showed that 49% were
autosomes, 33. 5% were autosomal fragments, and 17.5% were X chromosomes. The X
chromosome represented one-fourth of all lagging chromosomes and was involved
much more often than would be expected by chance (1/23). Labeling of the late
replicating inactive X chromosome with 5-bromo-2'-deoxyuridine revealed that both
X homologues contributed equally to the laggards. Among 200 micronuclei examined
from interphase cells, the proportion of the X chromosome (31%) and autosomal
fragments (50%) was higher than among anaphase laggards, whereas autosomes were
involved less often (19%). These findings may reflect either selection or the
fact that lagging autosomes, which were more proximal to the poles than were
lagging X chromosomes, were more frequently included within the main nucleus. Our
results suggest that the well-known high micronucleation and loss of the X
chromosome in women's lymphocytes is the result of frequent distal lagging behind
in anaphase and effective micronucleation of this chromosome. This lagging
appears to affect the inactive and active X chromosomes equally.
PMID- 10677327
TI - Age estimate of the N370S mutation causing Gaucher disease in Ashkenazi Jews and
European populations: A reappraisal of haplotype data.
AB - The N370S mutation at the GBA locus on human chromosome 1q21, which causes
Gaucher disease (GD), has a high frequency in the Ashkenazim and is the second
most-widespread GD mutation in the European non-Jewish population. A common
ancient origin for the N370S mutation in the Ashkenazi Jewish and Spanish
populations has been proposed on the basis of both a similar haplotype for
associated markers and an age estimate that suggests that this mutation appeared
several thousand years ago. However, a reappraisal of haplotype data, using the
Risch formula properly along with a Luria-Delbruck setting of the genetic clock,
allows identification of the likely origin of the N370S mutation in Ashkenazi
Jews between the 11th and 13th centuries. This result is consistent with the
estimated ages of other mutations that are frequent among Ashkenazim, with the
exception of type II (Glu117Stop) factor XI deficiency, which is deemed to be
>3000 years old, predating the separation of the Ashkenazi and Iraqi Jews. The
present finding supports the hypothesis of a more recent origin for the N370S
mutation and is consistent with both a founder chromosome transfer from
Ashkenazim who assimilated in some European populations and a non-Jewish origin
of the European N370S-bearing chromosomes.
PMID- 10677328
TI - A new locus for generalized epilepsy with febrile seizures plus maps to
chromosome 2.
AB - Generalized epilepsy with febrile seizures plus (GEFS+) is a recently recognized
but relatively common form of inherited childhood-onset epilepsy with
heterogeneous epilepsy phenotypes. We genotyped 41 family members, including 21
affected individuals, to localize the gene causing epilepsy in a large family
segregating an autosomal dominant form of GEFS+. A genomewide search examining
197 markers identified linkage of GEFS+ to chromosome 2, on the basis of an
initial positive LOD score for marker D2S294 (Z=4.4, recombination fraction
[straight theta] = 0). A total of 24 markers were tested on chromosome 2q, to
define the smallest candidate region for GEFS+. The highest two-point LOD score
(Zmax=5.29; straight theta=0) was obtained with marker D2S324. Critical
recombination events mapped the GEFS+ gene to a 29-cM region flanked by markers
D2S156 and D2S311, with the idiopathic generalized epilepsy locus thereby
assigned to chromosome 2q23-q31. The existence of the heterogeneous epilepsy
phenotypes in this kindred suggests that seizure predisposition determined by the
GEFS+ gene on chromosome 2q could be modified by other genes and/or by
environmental factors, to produce the different seizure types observed.
PMID- 10677329
TI - A new locus for autosomal dominant pure spastic paraplegia, on chromosome 2q24
q34.
AB - Hereditary spastic paraplegia (HSP) comprises a group of clinically and
genetically heterogeneous disorders causing progressive spasticity and weakness
of the lower limbs. We report a large family of French descent with autosomal
dominant pure HSP. We excluded genetic linkage to the known loci causing HSP and
performed a genomewide search. We found evidence for linkage of the disorder to
polymorphic markers on chromosome 2q24-q34: a maximum LOD score of 3. 03 was
obtained for marker D2S2318. By comparison with families having linkage to the
major locus of pure autosomal dominant HSP (SPG4 on chromosome 2p), there were
significantly more patients without Babinski signs, with increased reflexes in
the upper limbs, and with severe functional handicaps.
PMID- 10677330
TI - Absence of significant linkage between phonological coding dyslexia and
chromosome 6p23-21.3, as determined by use of quantitative-trait methods:
confirmation of qualitative analyses.
AB - We recently reported the absence of significant linkage of phonological coding
dyslexia (PCD) to chromosome 6p23-p21.3 in 79 families with at least two affected
siblings, even though linkage of dyslexia to this region has been found in four
other independent studies. Whereas, in our previous analyses, we used a
qualitative (affected, unaffected, or uncertain) PCD phenotype, here we report a
reanalysis of linkage to the chromosome 6p region, by use of four quantitative
measures of reading disability: phonological awareness, phonological coding,
spelling, and rapid-automatized-naming (RAN) speed. The phonological-coding and
spelling measures were highly correlated with each other and with the qualitative
PCD phenotype, whereas the phonological-awareness and RAN-speed measures were
only moderately correlated with the other measures. Using two-point and
multipoint quantitative-trait sib-pair linkage analyses and variance-components
analyses, we were unable to detect significant evidence for a locus in the 6p23
p21.3 region influencing any of the quantitative reading measures, supporting our
previous qualitative linkage results. The most likely explanation for our
inability to detect linkage between dyslexia and this region is that families
with subtypes of dyslexia linked to this region are underrepresented in our
sample, because of either chance or varying ascertainment criteria.
PMID- 10677331
TI - Chromosome 6p influences on different dyslexia-related cognitive processes:
further confirmation.
AB - In this study, which is a continuation and an extension of an earlier study, we
enrolled two new families (N=31) and recruited more individuals from the
previously ascertained families (N=56). The eight multiplex families (N=171)
presented in this study were ascertained from a sample of adult probands whose
childhood reading history is well documented through archival information. Six
phenotypes were constructed to span a range of dyslexia-related cognitive
processes. These phenotypes were (1) phonemic awareness (of spoken words); (2)
phonological decoding (of printed nonwords); (3) rapid automatized naming (of
colored squares or object drawings); (4) single-word reading (orally, of printed
real words); (5) vocabulary; and (6) spelling (of dictated words). In addition,
the diagnosis of lifelong dyslexia was established by clinical means. Genotyping
was done with nine highly polymorphic markers from the 6p22.3-6p21.3 region. The
results of two- and multipoint identity-by-descent and identity-by-state analyses
supported the importance of a putative locus in the D6S464-D6S273 region for a
number of dyslexia-related cognitive deficits.
PMID- 10677332
TI - A third novel locus for primary autosomal recessive microcephaly maps to
chromosome 9q34.
AB - Primary autosomal recessive microcephaly is a clinical diagnosis of exclusion in
an individual with a head circumference >/=4 SDs below the expected age-and-sex
mean. There is associated moderate mental retardation, and neuroimaging shows a
small but structurally normal cerebral cortex. The inheritance pattern in the
majority of cases is considered to be autosomal recessive. Although genetic
heterogeneity for this clinical phenotype had been expected, this has only
recently been demonstrated, with the mapping of two loci for autosomal recessive
primary microcephaly: MCPH1 at 8p and MCPH2 at 19q. We have studied a large
multiaffected consanguineous pedigree, using a whole-genome search, and have
identified a third locus, MCPH3 at 9q34. The minimal critical region is
approximately 12 cM, being defined by the markers cen-D9S1872-D9S159-tel, with a
maximum two-point LOD score of 3.76 (recombination fraction 0) observed for the
marker D9S290.
PMID- 10677333
TI - A locus for autosomal dominant "pure" hereditary spastic paraplegia maps to
chromosome 19q13.
AB - Genetic loci for autosomal dominant pure hereditary spastic paraplegia (ADPHSP)
have been mapped to chromosomes 2p, 8q, 12q, 14q, and 15q. We undertook a
genomewide linkage screen of a large family with ADPHSP, for which linkage at all
previously identified ADPHSP loci was excluded. Analysis of markers on chromosome
19q gave a peak pairwise LOD score of 3.72 at D19S420, allowing assignment of a
novel ADPHSP locus (which we have termed "SPG12") to this region. Haplotype
construction and analysis of recombination events narrowed the SPG12 locus to a
16.1-cM region between markers D19S868 and D19S902.
PMID- 10677334
TI - Vacuoliting megalencephalic leukoencephalopathy with subcortical cysts, mapped to
chromosome 22qtel.
AB - The leukodystrophies form a complex group of orphan genetic disorders that
primarily affect myelin, the main constituent of the brain white matter. Among
the leukodystrophies of undetermined etiology, a new clinical entity called
"vacuoliting megalencephalic leukoencephalopathy" (VL) was recently recognized.
VL is characterized by diffuse swelling of the white matter, large subcortical
cysts, and megalencephaly with infantile onset. Family studies in several ethnic
groups have suggested an autosomal recessive mode of inheritance. We mapped the
VL gene to chromosome 22qtel, within a 3-cM linkage interval between markers
D22S1161 and n66c4 (maximum LOD score 10.12 at recombination fraction.0, for
marker n66c4; maximum multipoint LOD score 17 for this interval) by genome scan
of 13 Turkish families. Linkage analysis under the genetic-heterogeneity
hypothesis showed no genetic heterogeneity. No abnormalities were found in three
tested candidate genes (fibulin-1 and glutathione S-transferases 1 and 2).
PMID- 10677335
TI - Application and interpretation of transmission/disequilibrium tests: transmission
of HLA-DQ haplotypes to unaffected siblings in 526 families with type 1 diabetes.
AB - It is widely believed that, if a genetic marker shows a transmission distortion
in patients by the transmission/disequilibrium test (TDT), then a transmission
distortion in healthy siblings would be seen in the opposite direction. This is
also the case in a complex disease. Furthermore, it has been suggested that
replacing the McNemar statistics of the TDT with a test of heterogeneity between
transmissions to affected and unaffected children could increase the power to
detect disease association. To test these two hypotheses empirically, we analyzed
the transmission of HLA-DQA1-DQB1 haplotypes in 526 Norwegian families with type
1 diabetic children and healthy siblings, since some DQA1-DQB1 haplotypes
represent major genetic risk factors for type 1 diabetes. Despite the strong
positive and negative disease associations with particular DQ haplotypes, we
observed no significant deviation from 50% for transmission to healthy siblings.
This could be explained by the low penetrance of susceptibility alleles, together
with the fact that IDDM loci also harbor strongly protective alleles that can
override the risk contributed by other loci. Our results suggest that, in
genetically complex diseases, detectable distortion in transmission to healthy
siblings should not be expected. Furthermore, the original TDT seems more
powerful than a heterogeneity test.
PMID- 10677336
TI - The 1298(A-->C) mutation of methylenetetrahydrofolate reductase should be
designated to the 1289 position of the gene.
PMID- 10677338
TI - Special oversight groups to add protections for population-based repository
samples.
PMID- 10677339
TI - Letter to human genetics journals.
PMID- 10677340
TI - On the preparation of beta-haematin.
AB - Synthetic beta-haematin is considered to be identical, or at least very similar
to, purified malaria pigment. Methods for its preparation use ferriprotoporphyrin
IX at acid pH in the presence of acetic acid at different concentrations and
degrees of ionization, elevated temperatures and long reaction times. Here we
show that certain widely used reaction conditions, involving very high
concentrations of acetic acid/acetate mixtures, do not produce substantial
amounts of polymeric beta-haematin on immediate isolation of the reaction
products, but only during prolonged drying of the products at 37 degrees C after
washing with water. Alternative, more convenient methods of preparation of pure
beta-haematin are suggested.
PMID- 10677341
TI - The ShBle resistance determinant from Streptoalloteichus hindustanus is expressed
in Haloferax volcanii and confers resistance to bleomycin.
AB - We have designed a gene cassette for expression of the bleomycin-resistance
protein from Streptoalloteichus hindustanus (ShBle) in the extremely halophilic
archaeon Haloferax volcanii, and shown that transformed haloarchaea are resistant
to bleomycin. Recombinant ShBle was purified by a one-step affinity
chromatography procedure as a correctly folded, dimeric protein. ShBle thus
provides a useful haloarchaeal selectable marker and represents the first non
halophilic and soluble heterologous protein to be expressed in the Haloarchaea.
PMID- 10677342
TI - Mechanism of thermal denaturation of maltodextrin phosphorylase from Escherichia
coli.
AB - Maltodextrin phosphorylase from Escherichia coli (MalP) is a dimeric protein in
which each approximately 90-kDa subunit contains active-site pyridoxal 5'
phosphate. To unravel factors contributing to the stability of MalP, thermal
denaturations of wild-type MalP and a thermostable active-site mutant (Asn-133-
>Ala) were compared by monitoring enzyme activity, cofactor dissociation,
secondary structure content and aggregation. Small structural transitions of MalP
are shown by Fourier-transform infrared spectroscopy to take place at
approximately 45 degrees C. They are manifested by slight increases in unordered
structure and (1)H/(2)H exchange, and reflect reversible inactivation of MalP.
Aggregation of the MalP dimer is triggered by these conformational changes and
starts at approximately 45 degrees C without prior release into solution of
pyridoxal 5'-phosphate. It is driven by electrostatic rather than hydrophobic
interactions between MalP dimers, and leads to irreversible inactivation of the
enzyme. Aggregation is inhibited efficiently and specifically by oxyanions such
as phosphate, and AMP which therefore, stabilize MalP against the irreversible
denaturation step at 45 degrees C. Melting of the secondary structure in soluble
and aggregated MalP takes place at much higher temperatures of approx. 58 and 67
degrees C, respectively. Replacement of Asn-133 by Ala does not change the
mechanism of thermal denaturation, but leads to a shift of the entire pathway to
a approximately 15 degrees C higher value on the temperature scale. Apart from
greater stability, the Asn-133-->Ala mutant shows a 2-fold smaller turnover
number and a 4.6-fold smaller energy of activation than wild-type MalP, probably
indicating that the site-specific replacement of Asn-133 brings about a greater
rigidity of the active-site environment of the enzyme. A structure-based model is
proposed which explains the stabilizing interaction between MalP and oxyanions,
or AMP.
PMID- 10677343
TI - Some polyphenols inhibit the formation of pentyl radical and octanoic acid
radical in the reaction mixture of linoleic acid hydroperoxide with ferrous ions.
AB - Effects of some polyphenols and their related compounds (chlorogenic acid,
caffeic acid, quinic acid, ferulic acid, gallic acid, D-(+)-catechin, D-(-)
catechin, 4-hydroxy-3-methoxybenzoic acid, salicylic acid, L-dopa, dopamine, L
adrenaline, L-noradrenaline, o-dihydroxybenzene, m-dihydroxybenzene, and p
dihydroxybenzene) on the formation of 13-hydroperoxide octadecadienoic (13-HPODE)
acid-derived radicals (pentyl radical and octanoic acid radical) were examined.
The ESR spin trapping showed that chlorogenic acid, caffeic acid, gallic acid, D
(+)-catechin, D-(-)-catechin, L-dopa, dopamine, L-adrenaline, L-noradrenaline,
and o-dihydroxybenzene inhibited the overall formation of 13-HPODE acid-derived
radicals in the reaction mixture of 13-HPODE with ferrous ions. The ESR peak
heights of alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN)/13-HPODE
derived radical adducts decreased to 46+/-4% (chlorogenic acid), 54+/-2% (caffeic
acid), 49+/-2% (gallic acid), 55+/-1% [D-(+)-catechin], 60+/-3% [D-(-)-catechin],
42+/-1% (L-dopa), 30+/-2% (dopamine), 49+/-2% (L-adrenaline), 24+/-2% (L
noradrenaline), and 54+/-5% (o-dihydroxybenzene) of the control, respectively.
The high performance liquid chromatography-electron spin resonance (HPLC-ESR) and
high performance liquid chromatography-electron spin resonance-mass
spectrometries (HPLC-ESR-MS) showed that caffeic acid inhibited the formation of
octanoic acid radical and pentyl radical to 42+/-2% and 52+/-7% of the control,
respectively. On the other hand, the polyphenols and their related compounds had
few inhibitory effects on the radical formation in the presence of EDTA. Visible
absorbance measurement revealed that all the polyphenols exhibiting the
inhibitory effect chelate ferrous ions. Above results indicated that the
chelation of ferrous ion is essential to the inhibitory effects of the
polyphenols.
PMID- 10677344
TI - Ca2+ and calmodulin differentially modulate myo-inositol 1,4, 5-trisphosphate
(IP3)-binding to the recombinant ligand-binding domains of the various IP3
receptor isoforms.
AB - We have expressed the N-terminal 581 amino acids of type 1 myo-inositol 1,4,5
trisphosphate receptor (IP(3)R1), IP(3)R2 and IP(3)R3 as recombinant proteins
[ligand-binding site 1 (lbs-1), lbs-2, lbs-3] in the soluble fraction of
Escherichia coli. These recombinant proteins contain the complete IP(3)-binding
domain and bound IP(3) and adenophostin A with high affinity. Ca(2+) and
calmodulin were previously found to maximally inhibit IP(3) binding to lbs-1 by
42+/-6 and 43+/-6% respectively, and with an IC(50) of approx. 200 nM and 3
microM respectively [Sipma, De Smet, Sienaert, Vanlingen, Missiaen, Parys and De
Smedt (1999) J. Biol. Chem. 274, 12157-12562]. We now report that Ca(2+)
inhibited IP(3) binding to lbs-3 with an IC(50) of approx. 700 nM (37+/-4%
inhibition at 5 microM Ca(2+)), while IP(3) binding to lbs-2 was not affected by
increasing [Ca(2+)] from 100 nM to 25 microM. Calmodulin (10 microM) inhibited
IP(3) binding to lbs-3 by 37+/-4%, while IP(3) binding to lbs-2 was inhibited by
only 11+/-2%. The inhibition of IP(3) binding to lbs-3 by calmodulin was dose
dependent (IC(50) approximately 2 microM). We conclude that the IP(3)-binding
domains of the various IP(3)R isoforms differ in binding characteristics for
IP(3) and adenophostin A, and are differentially modulated by Ca(2+) and
calmodulin, suggesting that the various IP(3)R isoforms can have different
intracellular functions.
PMID- 10677345
TI - Pancreatic eukaryotic initiation factor-2alpha kinase (PEK) homologues in humans,
Drosophila melanogaster and Caenorhabditis elegans that mediate translational
control in response to endoplasmic reticulum stress.
AB - In response to different cellular stresses, a family of protein kinases regulates
translation by phosphorylation of the alpha subunit of eukaryotic initiation
factor-2 (eIF-2alpha). Recently, we identified a new family member, pancreatic
eIF-2alpha kinase (PEK) from rat pancreas. PEK, also referred to as RNA-dependent
protein kinase (PKR)-like endoplasmic reticulum (ER) kinase (PERK) is a
transmembrane protein implicated in translational control in response to stresses
that impair protein folding in the ER. In this study, we identified and
characterized PEK homologues from humans, Drosophila melanogaster and
Caenorhabditis elegans. Expression of human PEK mRNA was found in over 50
different tissues examined, with highest levels in secretory tissues. In
mammalian cells subjected to ER stress, we found that elevated eIF-2alpha
phosphorylation was coincident with increased PEK autophosphorylation and eIF
2alpha kinase activity. Activation of PEK was abolished by deletion of PEK N
terminal sequences located in the ER lumen. To address the role of C. elegans PEK
in translational control, we expressed this kinase in yeast and found that it
inhibits growth by hyperphosphorylation of eIF-2alpha and inhibition of eIF-2B.
Furthermore, we found that vaccinia virus K3L protein, an inhibitor of the eIF
2alpha kinase PKR involved in an anti-viral defence pathway, also reduced PEK
activity. These results suggest that decreased translation initiation by PEK
during ER stress may provide the cell with an opportunity to remedy the folding
problem prior to introducing newly synthesized proteins into the secretory
pathway.
PMID- 10677346
TI - Target site search and effective inhibition of leukaemic cell growth by a
covalently closed multiple anti-sense oligonucleotide to c-myb.
AB - Systematic secondary structure simulation of a target mRNA sequence is shown to
be effective for locating a good anti-sense target site. Multiple selected anti
sense sequences were placed in a single molecule. The anti-sense oligonucleotide
(oligo) was covalently closed to avoid exonuclease activities and was designated
CMAS (covalently closed multiple anti-sense)-oligo. CMAS-oligo was found to be
stable, largely preserving its structural integrity after 24 h of incubation in
the presence of either exonuclease III or serum. When human c-myb mRNA was
targeted by the c-myb CMAS-oligo, expression of the gene was completely
abolished. Further, tumour cell growth was inhibited by 82+/-3% as determined by
an MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay
and by 90+/-1% by [(3)H]thymidine incorporation. When a leukaemic cell line K562
was treated with CMAS-oligo, colony formation on soft agarose was also decreased
by 93%. In contrast, treatment with a scrambled control oligo did not
significantly inhibit leukaemic cell growth. These results suggest that a
rational target site search is possible for an anti-sense oligo and that CMAS
oligo can be employed as an effective anti-sense agent with enhanced stability.
PMID- 10677347
TI - HIV-2 protease is inactivated after oxidation at the dimer interface and activity
can be partly restored with methionine sulphoxide reductase.
AB - Human immunodeficiency viruses encode a homodimeric protease that is essential
for the production of infectious virus. Previous studies have shown that HIV-1
protease is susceptible to oxidative inactivation at the dimer interface at Cys
95, a process that can be reversed both chemically and enzymically. Here we
demonstrate a related yet distinct mechanism of reversible inactivation of the
HIV-2 protease. Exposure of the HIV-2 protease to H(2)O(2) resulted in conversion
of the two methionine residues (Met-76 and Met-95) to methionine sulphoxide as
determined by amino acid analysis and mass spectrometry. This oxidation
completely inactivated protease activity. However, the activity could be restored
(up to 40%) after exposure of the oxidized protease to methionine sulphoxide
reductase. This treatment resulted in the reduction of methionine sulphoxide 95
but not methionine sulphoxide 76 to methionine, as determined by peptide
mapping/mass spectrometry. We also found that exposure of immature HIV-2
particles to H(2)O(2) led to the inhibition of polyprotein processing in maturing
virus particles comparable to that demonstrated for HIV-1 particles. Thus
oxidative inactivation of the HIV protease in vitro and in maturing viral
particles is not restricted to the type 1 proteases. These studies indicate that
two distinct retroviral proteases are susceptible to inactivation after a very
minor modification at residue 95 of the dimer interface and suggest that the
dimer interface might be a viable target for the development of novel protease
inhibitors.
PMID- 10677348
TI - Inhibition of atrial natriuretic peptide (ANP) C receptor expression by antisense
oligodeoxynucleotides in A10 vascular smooth-muscle cells is associated with
attenuation of ANP-C-receptor-mediated inhibition of adenylyl cyclase.
AB - Atrial natriuretic peptide (ANP) mediates a variety of physiological effects
through its interaction with ANP-A, ANP-B or ANP-C receptors. However,
controversies exist regarding the involvement of ANP-C receptor and adenylyl
cyclase/cAMP signal-transduction systems to which these receptors are coupled in
mediating these responses. In the present studies, we have employed an antisense
approach to eliminate the ANP-C receptor and to examine the effect of this
elimination on adenylyl cyclase inhibition. An 18-mer antisense phosphorothioate
oligodeoxynucleotide (OH-2) targeted at the initiation codon of the ANP-C
receptor was used to examine its effects on the expression of the ANP-C receptor
and ANP-C-receptor-mediated inhibition of adenylyl cyclase in vascular smooth
muscle cells (A10). Treatment of the cells with antisense oligonucleotide
resulted in complete attenuation of C-ANP(4-23) [des(Gln(18), Ser(19), Gln(20),
Leu(21), Gly(22))ANP(4-23)-NH(2)]-mediated inhibition of adenylyl cyclase,
whereas sense and missense oligomers did not affect the inhibition of adenylyl
cyclase by C-ANP(4-23). In addition, the stimulatory effects of guanine
nucleotides, isoproterenol, sodium fluoride and forskolin as well as the
inhibitory effects of angiotensin II on adenylyl cyclase were not affected by
antisense-oligonucleotide treatment. The attenuation of C-ANP(4-23)-mediated
inhibition of adenylyl cyclase by antisense oligonucleotide was dose- and time
dependent. A complete attenuation of ANP-C-receptor-mediated inhibition of
adenylyl cyclase was observed at 2.5 microM. In addition, treatment of the cells
with antisense oligonucleotide and not with sense or missense oligomers resulted
in the inhibition of the levels of ANP-C-receptor protein and mRNA as determined
by immunoblotting and Northern blotting using antisera against the ANP-C receptor
and a cDNA probe of the ANP-C receptor respectively. On the other hand, ANP-A/B
receptor-mediated increases in cGMP levels were not inhibited by antisense
oligonucleotide treatment. Our results demonstrate conclusively that the
elimination of ANP-C receptor by antisense oligonucleotide attenuates ANP-induced
inhibition of adenylyl cyclase and provide evidence that antisense
oligonucleotide of the ANP-C receptor may serve as a useful pharmacological tool
to elucidate the physiological functions of the ANP-C receptor.
PMID- 10677349
TI - Actin filaments play a critical role in insulin-induced exocytotic recruitment
but not in endocytosis of GLUT4 in isolated rat adipocytes.
AB - Actin-based cytoskeletons have been implicated in insulin-stimulated glucose
transport and translocation of the insulin-regulated glucose transporter, GLUT4,
from the intracellular pool to the plasma membrane. However, most previous
studies were done using adherent cell systems such as L6 myotubes and 3T3-L1
adipocytes, and very little information is available on the significance of the
actin filaments to the insulin action in isolated adipocytes, a widely used
experimental system. In the present study, we investigated the physiological role
of actin filaments in the subcellular trafficking of GLUT4 in isolated rat
adipocytes. We first compared the effects of two actin-disrupting reagents,
latrunculin A and cytochalasin D, on the organization of the actin filaments as
well as on the insulin action on glucose transport by laser confocal microscopy
combined with biochemical analysis of the insulin action. Treatment of the cells
with latrunculin A induced dose- and time-dependent disappearance of the
filamentous actin, which correlated very well with inhibition of the insulin
effect on glucose transport. Although cytochalasin D at 50 microM significantly
inhibited insulin-stimulated glucose transport, it was not effective in
disassembly of the actin filaments; rather, many intense punctate signals were
observed in cytochalasin D-treated cells. In the actin-disrupted adipocytes
treated with latrunculin A, insulin-induced GLUT4 translocation was inhibited
completely. In addition, latrunculin A remarkably inhibited both insulin-induced
glucose transport and GLUT4 translocation in the presense of D(k)-(62-85), a
potent inhibitor of GLUT4 endocytosis, suggesting that intactness of the actin
filaments was necessary for insulin-induced exocytosis of the GLUT4-containing
vesicles. On the other hand, latrunculin A showed little inhibitory effect on
either endocytosis of the trypsin-cleaved 35-kDa fragment of GLUT4 or decay of
the glucose transport activity after addition of wortmannin in insulin-stimulated
cells. The results of our experiment show clearly that, in rat adipocytes, (i)
latrunculin A may be a more suitable tool than cytochalasin D for disruption of
actin filaments, and (ii) actin filaments play a crucial role in exocytotic
recruitment of GLUT4 to the plasma membrane from the intracellular pool, but not
in its endocytosis.
PMID- 10677350
TI - Zinc-regulated ubiquitin conjugation signals endocytosis of the yeast ZRT1 zinc
transporter.
AB - The yeast ZRT1 zinc transporter is regulated by zinc at both transcriptional and
post-translational levels. At the post-translational level, zinc inactivates ZRT1
by inducing the removal of the protein from the plasma membrane by endocytosis.
The zinc transporter is subsequently degraded in the vacuole. This regulatory
system allows for the rapid shut off of zinc uptake activity in cells exposed to
high zinc concentrations, thereby preventing overaccumulation of this potentially
toxic metal. In this report, we examine the role of ubiquitin conjugation in this
process. First, we show that ZRT1 is ubiquitinated shortly after zinc treatment
and before endocytosis. Secondly, mutations in various components of the
ubiquitin conjugation pathway, specifically the RSP5 ubiquitin-protein ligase and
the UBC4 and UBC5 ubiquitin conjugating enzymes, inhibit both ubiquitination and
endocytosis. Finally, mutation of a specific lysine residue in ZRT1 blocks both
ubiquitination and endocytosis. This critical lysine, Lys-195, is located in a
cytoplasmic loop region of the protein and may be the residue to which ubiquitin
is attached. These results demonstrate that ubiquitin conjugation is a critical
step in the signal transduction pathway that controls the rate of ZRT1
endocytosis in response to zinc.
PMID- 10677351
TI - Down-regulation of cyclic-nucleotide phosphodiesterase 3B in 3T3-L1 adipocytes
induced by tumour necrosis factor alpha and cAMP.
AB - We have used murine 3T3-L1 cells, which differentiate in culture and acquire
morphological and biochemical features of mature adipocytes, as a model for
studying the expression of cyclic-nucleotide phosphodiesterase (PDE) 3B activity,
protein and mRNA during differentiation and during long-term treatment of the
cells with tumour necrosis factor alpha (TNF-alpha), a cytokine associated with
insulin resistance, and a cAMP analogue, N(6),2'-O-dibutyryl cAMP (dbcAMP). PDE3B
activity, protein and mRNA could be detected 4 days after the initiation of
differentiation of 3T3-L1 preadipocytes. Treatment of 3T3-L1 adipocytes with 10
ng/ml TNF-alpha for 24 h produced a maximal (50%) decrease in PDE3B activity,
protein and mRNA, which was well correlated with both activation of protein
kinase A (PKA) and stimulation of lipolysis, presumably reflecting an increase in
intracellular cAMP concentration. To investigate the effect of cAMP on PDE3B we
treated 3T3-L1 adipocytes with dbcAMP. After 4 h with 0.5 mM dbcAMP, PDE3B
activity was decreased by 80%, which was also correlated with a decrease in PDE3B
protein and mRNA. This effect was abolished in the presence of N-[2
(bromocinnamylamino)ethyl]-5-isoquinolinesulphonamide] (H-89), a specific PKA
inhibitor. We conclude that the lipolytic effect of TNF-alpha involves the down
regulation of PDE3B, which is associated with increased activation of PKA,
presumably owing to increased levels of cAMP. In addition, the PKA activation
induced by dbcAMP resulted in the down-regulation of PDE3B. These results, which
suggest that PDE3B is a novel target for long-term regulation by TNF-alpha and
cAMP, could contribute to the understanding of the mechanisms of insulin
resistance.
PMID- 10677352
TI - Reagent or myeloperoxidase-generated hypochlorite affects discrete regions in
lipid-free and lipid-associated human apolipoprotein A-I.
AB - We have previously shown that the modification of high-density lipoprotein
subclass 3 (HDL(3)) by HOCl transformed an anti-atherogenic lipoprotein into a
high-uptake form for macrophages and caused a significant impairment of
cholesterol efflux capacity [Panzenboeck, Raitmayer, Reicher, Lindner, Glatter,
Malle and Sattler (1997) J. Biol. Chem. 272, 29711-29720]. To elucidate the
consequences of treatment with OCl(-) on distinct regions in apolipoprotein A-I
(apo A-I), lipid-free and lipid-associated apo A-I were modified with increasing
molar ratios of NaOCl or HOCl generated by the myeloperoxidase/H(2)O(2)/Cl(-)
system. CD analysis revealed a pronounced decrease in alpha-helicity for lipid
free apo A-I modified by NaOCl, whereas lipid-associated apo A-I was less
affected. The modification of apo A-I by NaOCl (molar oxidant-to-lipoprotein
ratio 6:1) resulted in the formation of two distinct oxidized forms of apo A-I
with molecular masses 32 or 48 atomic mass units (a.m.u.) higher than that of
native apo A-I, indicating the addition of two or three oxygen atoms to the
native protein. HPLC analysis of tryptic digests obtained from lipid-free and
lipid-associated apo A-I modified with increasing oxidant-to-apolipoprotein molar
ratios revealed a concentration-dependent modification of apo A-I: at a low molar
oxidant-to-lipoprotein ratio (5:1) the peaks corresponding to the methionine
containing tryptic peptides T11 (residues 84-88), T16 (residues 108-116) and T22
(residues 141-149), located in the central region of apo A-I, disappeared. Their
loss was accompanied by the formation of three oxidation products with a
molecular mass 16 a.m.u. higher than that of the native peptides. This indicates
the addition of oxygen, most probably caused by the oxidation of Met(86),
Met(112) and Met(148) to the corresponding methionine sulphoxides. At a molar
NaOCl-to-apo A-I ratio of 10:1 the disappearance of peptides T1 (residues 1-10),
T7 (residues 46-59) and T9 (residues 62-77) was accompanied by the occurrence of
new peaks 33.5 and 33.1 a.m.u. higher than those of the native peptides. Amino
acid analyses of peptides T7 and T9 after modification with NaOCl confirmed that
Phe(57) and Phe(71) were primary targets for oxidation by HOCl. GLC-MS analysis
of hydrolysates obtained from OCl(-)-modified T7, T9, apo A-I and HDL(3)
confirmed that Phe residues are an early target for OCl(-) modification. At molar
NaOCl-to-apo A-I ratios of 25:1, the peak areas of peptides T31 (residues 189
195) and T32 (residues 196-206) decreased markedly. Most importantly, incubation
of apo A-I with the myeloperoxidase/H(2)O(2)/Cl(-) system (the source of HOCl in
vivo) resulted in almost identical modification patterns to those observed with
reagent NaOCl.
PMID- 10677353
TI - Enzyme activity and dynamics: xylanase activity in the absence of fast anharmonic
dynamics.
AB - The activity and dynamics of a simple, single subunit enzyme, the xylanase from
Thermotoga maritima strain Fj SS3B.1 have been measured under similar conditions,
from -70 to +10 degrees C. The internal motions of the enzyme, as evidenced by
neutron scattering, undergo a sharp transition within this temperature range;
they show no evidence for picosecond-timescale anharmonic behaviour (e.g. local
diffusive motions or jumps between alternative conformations) at temperatures
below -50 degrees C, whereas these motions are strongly activated at higher
temperatures. The activity follows Arrhenius behaviour over the whole of the
temperature range investigated, -70 to +10 degrees C. The results indicate that a
temperature range exists over which the enzyme rate-limiting step is independent
of fast anharmonic dynamics.
PMID- 10677354
TI - Stimulation of cleavage of membrane proteins by calmodulin inhibitors.
AB - The ectodomain of several membrane-bound proteins can be shed by proteolytic
cleavage. The activity of the proteases involved in shedding is highly regulated
by several intracellular second messenger pathways, such as protein kinase C
(PKC) and intracellular Ca(2+). Recently, the shedding of the adhesion molecule L
selectin has been shown to be regulated by the interaction of calmodulin (CaM)
with the cytosolic tail of L-selectin. Prevention of CaM-L-selectin interaction
by CaM inhibitors or mutation of a CaM binding site in L-selectin induced L
selectin ectodomain shedding. Whether this action of CaM inhibitors also affects
other membrane-bound proteins is not known. In the present paper we show that CaM
inhibitors also stimulate the cleavage of several other transmembrane proteins,
such as the membrane-bound growth factor precursors pro-transforming growth
factor-alpha and pro-neuregulin-alpha2c, the receptor tyrosine kinase, TrkA, and
the beta-amyloid precursor protein. Cleavage induced by CaM inhibitors was a
rapid event, and resulted from the activation of a mechanism that was independent
of PKC or intracellular Ca(2+) increases, but was highly sensitive to hydroxamic
acid-based metalloprotease inhibitors. Mutational analysis of the intracellular
domain of the TrkA receptor indicated that CaM inhibitors may stimulate membrane
protein ectodomain cleavage by mechanisms independent of CaM-substrate
interaction.
PMID- 10677355
TI - Stress-induced generation of N-acylethanolamines in mouse epidermal JB6 P+ cells.
AB - It has long been known that N-acylethanolamine phospholipids [N
acylphosphatidylethanolamine (N-acyl PE)] and N-acylethanolamines (NAEs)
accumulate in mammalian tissues undergoing degenerative membrane changes
associated with necrosis. Here we studied the effects of stress factors (UVB
irradiation and serum deprivation) on the endogenous levels of N-acyl PE and NAE
in mouse epidermal JB6 P(+) cells. We found that 16:0, 18:0, 18:1,n-9 and 18:1,n
7 are the predominant amide-linked fatty acids in both N-acyl PE and NAE in these
cells. UVB irradiation and serum deprivation resulted in significantly increased
levels of N-acyl PE and NAE, especially 18:1, n-9 N-acyl PE and NAE. UVB
challenge increased the cellular content of anandamide (20:4,n-6 NAE), but this
increase was the lowest of all NAEs measured. Serum deprivation resulted in a
decreased cellular anandamide level, as well as a decrease in 20:4,n-6 N-acyl PE.
Interestingly, the replacement of serum-free medium with medium containing 5%
(v/v) fetal calf serum after 36 h of serum deprivation restored N-acyl PE and NAE
levels almost completely within 4-8 h. These data suggest the involvement of N
acyl PE and NAE in cellular responses to stress.
PMID- 10677356
TI - Ferredoxin III of Desulfovibrio africanus: sequencing of the native gene and
characterization of a histidine-tagged form.
AB - Desulfovibrio africanus ferredoxin III (Da FdIII) contains one [4Fe-4S](2+/1+)
cluster and one [3Fe-4S](1+/0) cluster, bound by seven Cys residues, in which the
[3Fe-4S] cluster is co-ordinated by the unusual sequence, Cys(11)-Xaa-Xaa-Asp(14)
Xaa-Xaa-Cys(17)-Xaa(n)-Cys(51)-Glu. The [3Fe-4S] core of this ferredoxin is so
far unique in showing rapid bi-directional [3Fe-4S]<-->[4Fe-4S] cluster
interconversion with a wide range of metal ions. In order to obtain protein for
mutagenesis studies Da FdIII has been cloned, sequenced, and expressed as a hexa
histidine tagged (ht) polypeptide in Escherichia coli strain BL21(DE3) pLysS.
Expression of ht Da FdIII, whether translated from a synthetic gene (pJB10) or
from the native nucleotide sequence (pJB11), occurred at similar levels (approx.
6 mg.l(-1)), but without incorporation of metal clusters. The nucleotide sequence
confirms the protein sequence reported previously [Bovier-Lapierre, Bruschi,
Bonicel and Hatchikian (1987) Biochim. Biophys. Acta 913, 20-26]. Cluster
incorporation was achieved using FeCl(3) together with cysteine sulphur
transferase, NifS, plus cysteine to generate low levels of sulphide ions.
Absorption and EPR spectroscopy show that both [3Fe-4S] and [4Fe-4S] clusters are
correctly inserted. Thin-film electrochemistry provides evidence that the [3Fe
4S] cluster undergoes reversible cluster transformation in the presence of Fe(II)
and Zn(II) ions with properties identical to the native protein. Nevertheless the
protein has lower stability than native Da FdIII during chromatography. The one
dimensional 600 MHz NMR spectrum of the apoprotein indicates an unstructured
protein with random coil chemical shifts whereas spectra of the reconstituted ht
protein show secondary structural elements and 18 peaks shifted downfield of 9.6
p.p.m. The spectra are unique but have similarities with the shift patterns seen
with 7Fe Desulfurolobus ambivalens Fd. The ht does not affect iron-sulphur
cluster incorporation, but NMR evidence suggests that excess Fe binds to the tag.
This may account for the lower stability of the ht compared with the native
protein.
PMID- 10677357
TI - Estimation of systolic and diastolic free intracellular Ca2+ by titration of Ca2+
buffering in the ferret heart.
AB - Spectroscopic Ca(2+)-indicators are thought to report values of free
intracellular Ca(2+) concentration ([Ca(2+)](i)) that may differ from unperturbed
values because they add to the buffering capacity of the tissue. To check this
for the heart we have synthesized a new (19)F-labelled NMR Ca(2+) indicator, 1, 2
bis-[2-bis(carboxymethyl)amino-4,5-difluorophenoxy]ethane ('4, 5FBAPTA'), with a
low affinity (K(d) 2950 nM). The new indicator and four previously described
(19)F-NMR Ca(2+) indicators 1,2-bis-[2-(1 - carboxyethyl)(carboxymethyl)amino - 5
- fluorophenoxy]ethane ('DiMe-5FBAPTA'), 1, 2-bis-[2-(1
carboxyethyl)(carboxymethyl)amino-4-fluorophenoxy]ethane ('DiMe-4FBAPTA'), 1, 2
bis-[2-bis(carboxymethyl)amino-5-fluorophenoxy]ethane ('5FBAPTA') and 1, 2-bis-[2
bis(carboxymethyl)amino-5-fluoro-4-methylphenoxy]ethane ('MFBAPTA'), with
dissociation constants for Ca(2+) ranging from 46 to 537 nM, have been used to
measure [Ca(2+)](i), over the range from less than 100 nM to more than 3 microM,
in Langendorff-perfused ferret hearts (30 degrees C, pH 7.4, paced at 1.0 Hz) by
(19)F-NMR spectroscopy. Loading hearts with indicators resulted in buffering of
the Ca(2+) transient. The measured end-diastolic and peak-systolic [Ca(2+)](i)
were both positively correlated with indicator K(d). The positive correlations
between indicator K(d) and the measured end-diastolic and peak-systolic
[Ca(2+)](i) were used to estimate the unperturbed end-diastolic and peak-systolic
[Ca(2+)](i) by extrapolation to K(d)=0 (diastolic) and to K(d)=infinity
(systolic) respectively. The extrapolated values in the intact beating heart were
161 nM for end-diastolic [Ca(2+)](i) and 2650 nM for peak-systolic [Ca(2+)](i),
which agree well with values determined from single cells and muscle strips.
PMID- 10677358
TI - Ca2+ buffering in the heart: Ca2+ binding to and activation of cardiac
myofibrils.
AB - The measurement of cardiac Ca(2+) transients using spectroscopic Ca(2+)
indicators is significantly affected by the buffering properties of the
indicators. The aim of the present study was to construct a model of cardiac
Ca(2+) buffering that satisfied the kinetic constraints imposed by the maximum
attainable rates of cardiac contraction and relaxation on the Ca(2+) dissociation
rate constants and which would account for the observed effects of (19)F-NMR
indicators on the cardiac Ca(2+) transient in the Langendorff-perfused ferret
heart. It is generally assumed that the Ca(2+) dependency of myofibril activation
in cardiac myocytes is mediated by a single Ca(2+)-binding site on troponin C. A
model based on 1:1 Ca(2+) binding to the myofilaments, however, was unable to
reproduce our experimental data, but a model in which we assumed ATP-dependent co
operative Ca(2+) binding to the myofilaments was able to reproduce these data.
This model was used to calculate the concentration and dissociation constant of
the ATP-independent myofilament Ca(2+) binding, giving 58 and 2.0 microM
respectively. In addition to reproducing our experimental data on the
concentration of free Ca(2+) ions in the cytoplasm ([Ca(2+)](i)), the resulting
Ca(2+) and ATP affinities given by fitting of the model also provided good
predictions of the Ca(2+) dependence of the myofibrillar ATPase activity measured
under in vitro conditions. Solutions to the model also indicate that the Ca(2+)
mobilized during each beat remains unchanged in the presence of the additional
buffering load from Ca(2+) indicators. The new model was used to estimate the
extent of perturbation of the Ca(2+) transient caused by different concentrations
of indicators. As little as 10 microM of a Ca(2+) indicator with a dissociation
constant of 200 nM will cause a 20% reduction in peak-systolic [Ca(2+)](i) and 30
microM will cause approx. 50% reduction in the peak-systolic [Ca(2+)](i) in a
heart paced at 1.0 Hz.
PMID- 10677359
TI - Thyroxine regulation of monolysocardiolipin acyltransferase activity in rat
heart.
AB - Treatment of rats with thyroxine has been shown to elevate the biosynthesis and
content of cardiolipin in the heart [Cao, Cheng, Angel and Hatch (1995) Biochim.
Biophys. Acta 1256, 241-244]. Treatment with thyroxine resulted in a 1.8-fold
increase (P<0.025) in [1-(14)C]linoleate and a 1.7-fold increase (P<0.025) in [1
(14)C]oleate incorporated into cardiolipin in perfused hearts, compared with
controls. The mechanism for the elevation in incorporation of unsaturated fatty
acids into cardiolipin was a 1. 6-fold (P<0.025) increase in mitochondrial
monolysocardiolipin acyltransferase activity. The results demonstrate that the
acylation of cardiac monolysocardiolipin is regulated by thyroid hormone. Thus an
elevation in cardiolipin biosynthesis is accompanied by an elevation in
monolysocardiolipin acyltransferase activity to maintain the appropriate
molecular species composition of cardiolipin in the cardiac mitochondrial
membrane. We postulate that monolysocardiolipin acyltransferase might be a rate
limiting enzyme for the molecular remodelling of cardiolipin in the heart.
PMID- 10677360
TI - Continuous exposure to high concentrations of nitric oxide leads to persistent
inhibition of oxygen consumption by J774 cells as well as extraction of oxygen by
the extracellular medium.
AB - Nitric oxide (NO) plays a key role in many physiological and pathophysiological
events, including the control of cell respiration. Both reversible and
irreversible inhibition of mitochondrial respiration have been reported following
the generation of NO by cells. We have exposed the murine macrophage cell line
J774 to high concentrations of NO, such as are generated in some pathological
conditions, and determined their effect on oxygen consumption. We observed a
persistent inhibition of respiration which was due to a redox-dependent,
progressive inhibition of complex I activity. No other enzyme of the respiratory
chain was inhibited in this way. At the same time, we detected a paradoxical
removal of oxygen by the extracellular medium. This removal was due to a chemical
interaction between dissolved oxygen and NO-related species released from cells
exposed to NO. A similar removal of oxygen by the cell supernatant also occurred
following activation of cells with cytokines and bacterial products. Thus, the
amounts of NO generated during pathological conditions may contribute to tissue
hypoxia both by inhibiting cell respiration and by promoting removal of oxygen
from the extracellular medium.
PMID- 10677361
TI - Investigation of the mechanism by which glucose analogues cause translocation of
glucokinase in hepatocytes: evidence for two glucose binding sites.
AB - Glucokinase translocates between the cytoplasm and nucleus of hepatocytes where
it is bound to a 68 kDa protein. The mechanism by which glucose induces
translocation of glucokinase from the nucleus was investigated using glucose
analogues that are not phosphorylated by glucokinase. There was strong synergism
on glucokinase translocation between effects of glucose analogues (glucosamine, 5
thioglucose, mannoheptulose) and sorbitol, a precursor of fructose 1-phosphate.
In the absence of glucose or glucose analogues, sorbitol had a smaller effect
than glucose on translocation. However, sorbitol potentiated the effects of
glucose analogues. In the absence of sorbitol the effect of glucose on
glucokinase translocation is sigmoidal with a Hill coefficient of 1.9 suggesting
involvement of two glucose-binding sites. The effects of glucosamine and 5
thioglucose were also sigmoidal but with lower Hill Coefficients. In the presence
of sorbitol, the effects of glucose, glucosamine and 5-thioglucose were
hyperbolic. Mannoheptulose, unlike the other glucose analogues, had a hyperbolic
effect on glucokinase translocation in the absence of sorbitol suggesting
interaction with one site and was synergistic rather than competitive with
glucose. The results favour a two-site model for glucokinase translocation
involving either two glucose-binding sites or one binding-site for glucose and
one for fructose 1-phosphate. The glucose analogues differed in their effects on
the kinetics of purified glucokinase. Mannoheptulose caused the greatest decrease
in co-operativity of glucokinase for glucose whereas N-acetylglucosamine had the
smallest effect. The anomalous effects of mannoheptulose on glucokinase
translocation and on the kinetics of purified glucokinase could be explained by a
second glucose-binding site on glucokinase.
PMID- 10677362
TI - Identification and expression of an allergen Asp f 13 from Aspergillus fumigatus
and epitope mapping using human IgE antibodies and rabbit polyclonal antibodies.
AB - The Aspergillus genus of fungi is known to be one of the most prevalent
aeroallergens. On two-dimensional immunoblotting using patients' sera containing
IgE specific for Asp f 13, an allergen with a molecular mass of 33 kDa and a pI
of 6.2 was identified. This allergen was also present in A. fumigatus culture
filtrates. Furthermore, the sequence of the Asp f 13 cDNA was identical to that
for alkaline protease isolated from A. fumigatus and showed 42-49% identity of
amino acids with two proteases from P. cyclopium and T. album and with the Pen c
1 allergen from P. citrinum. Asp f 13 coding sequences were expressed in
Escherichia coli as a [His](6)-tagged fusion protein which was purified by Ni(2+)
chelate affinity chromatography. Recombinant Asp f 13 was recognized by rabbit
polyclonal antibodies against Asp f 13 and by IgE antibodies from subject
allergic to A. fumigatus. To identify and characterize the linear epitopes of
this allergen, a combination of chemical and enzymatic cleavage and
immunoblotting techniques, with subsequent N-terminal sequencing and mass
spectrometry, were performed. At least 13 different linear epitopes reacting with
the rabbit anti-Asp f 13 antiserum were identified, located throughout the entire
molecule. In contrast, IgE from A. fumigatus-sensitive patients bound to three
immunodominant epitopes at the C-terminal of the protein.
PMID- 10677363
TI - Protein phosphatase 2A is associated in an inactive state with microtubules
through 2A1-specific interaction with tubulin.
AB - Protein phosphatase (PP) 2A1, a trimer composed of A-, B- and C-subunits in the
PP2A family, has been regarded as a principal form localizing at microtubules
(MT), but PP2A2, the dimer of A- and C-subunits, has not. Substantiating the
claim, the present work shows that the PP2A1 but not PP2A2, both isolated from
bovine extract, largely associated with the purified preparation of MT.
Furthermore, PP2A1 was found to bind purifiedtubulin polymerized by taxol. The
presence of MT associated proteins with purified tubulin hardly affected the
binding of PP2A1 to the tubulin. In addition, PP2A1 activity towards glycogen
phosphorylase, a probably unphysiological but good substrate, was similarly
inhibited by MT proteins and purified tubulin, which accounts for > or =85% of MT
proteins, with their IC(50) of about 0.15 mg/ml. In contrast, the inhibition of
PP2A2 was about 40% with 1 mg/ml MT proteins and 20% with 0.8 mg/ml tubulin,
consistent with its weak association with MT. Therefore, the association with and
resultant inhibition by MT proteins of PP2A1 is largely effected by the binding
of PP2A1 to tubulin molecule. Moreover, PP2A1 isolated from MT has higher
affinity for polymerized MT proteins than has PP2A1 from the postmicrotubule
supernatant. The MT PP2A1 has also higher sensitivity to the inhibition by
tubulin and MT proteins than has the supernatant PP2A1 (IC(50): 0.1-0.2 mg/ml vs.
0.3-0.6 mg/ml), demonstrating the importance of its association with polymerized
tubulin.
PMID- 10677364
TI - Identification of a DNA-binding domain and an active-site residue of pseudorabies
virus DNase.
AB - The pseudorabies virus (PRV) DNase gene has an open reading frame of 1476 nt,
capable of coding a 492-residue protein. A previous study showed that PRV DNase
is an alkaline exonuclease and endonuclease, exhibiting an Escherichia coli
RecBCD-like catalytic function. To analyse its catalytic mechanism further, we
constructed a set of clones truncated at the N-terminus or C-terminus of PRV
DNase. The deleted mutants were expressed in E. coli with the use of pET
expression vectors, then purified to homogeneity. Our results indicate that (1)
the region spanning residues 274-492 exhibits a DNA-binding ability 7-fold that
of the intact DNase; (2) the N-terminal 62 residues and the C-terminal 39
residues have important roles in 3'-exonuclease activity, and (3) residues 63-453
are responsible for 5'- and 3'-exonuclease activities. Further chemical
modification of PRV DNase revealed that the inactivation of DNase by diethyl
pyrocarbonate, which was reversible on treatment with hydroxylamine, seemed to be
attributable solely to the modification of histidyl residues. Because the
herpesviral DNases contained only one well-conserved histidine residue, site
directed mutagenesis was performed to replace His(371) with Ala. The mutant lost
most of its nuclease activity; however, it still exhibited a wild-type level of
DNA-binding ability. In summary, these results indicate that PRV DNase contains
an independent DNA-binding domain and that His(371) is the active-site residue
that has an essential role in PRV DNase activity.
PMID- 10677365
TI - Characterization of peptidyl boronic acid inhibitors of mammalian 20 S and 26 S
proteasomes and their inhibition of proteasomes in cultured cells.
AB - Proteasomes are large multisubunit proteinases which have several distinct
catalytic sites. In this study a series of di- and tri-peptidyl boronic acids
have been tested on the chymotrypsin-like activity of purified mammalian 20 S and
26 S proteasomes assayed with succinyl-Leu-Leu-Val-Tyr-amidomethylcoumarin (suc
Leu-Leu-Val-Tyr-AMC) as substrate. The inhibition of 20 S proteasomes is
competitive but only slowly reversible. The K(i) values for the best inhibitors
were in the range 10-100 nM with suc-Leu-Leu-Val-Tyr-AMC as substrate, but the
compounds tested were much less effective on other proteasome activities measured
with other substrates. Free boronic acid inhibitors exhibited equivalent potency
to their pinacol esters. Both benzoyl (Bz)-Phe-boroLeu and benzyloxycarbonyl
(Cbz)-Leu-Leu-boroLeu pinacol ester inhibited 20 S and 26 S proteasomes with non
ideal behaviour, differences in inhibition of the two forms of proteasomes
becoming apparent at high inhibitor concentrations (above 3xK(i)). Both of these
compounds were also potent inhibitors of 20 S and 26 S proteasomes in cultured
cells. However, gel filtration of cell extracts prepared from cells treated with
radiolabelled phenacetyl-Leu-Leu-boroLeu showed that only 20 S proteasomes were
strongly labelled, demonstrating differences in the characteristics of inhibition
of 20 S and 26 S proteasomes. The usefulness of peptidyl boronic acid inhibitors
for investigations of proteasome-mediated protein degradation was confirmed by
the observation that Bz-Phe-boroLeu and Cbz-Leu-Leu-boroLeu pinacol ester
inhibited NFkappaB activation with IC(50) values comparable to their K(i) values
for purified proteasomes. The latter result supports the view that the
chymotrypsin-like activity of proteasomes assayed with suc-Leu-Leu-Val-Tyr-AMC is
a critical one for protein degradation in cells.
PMID- 10677367
TI - Expression of heparan sulphate L-iduronyl 2-O-sulphotransferase in human kidney
293 cells results in increased D-glucuronyl 2-O-sulphation.
AB - Functionally important interactions between heparan sulphate and a variety of
proteins depend on the precise location of O-sulphate groups. Such residues occur
at C-2 of L-iduronic (IdoA) and D-glucuronic acid (GlcA) units, and at C-3 and C
6 of D-glucosamine (GlcN) units. Stable transfection of human embryonic kidney
293 cells with a cDNA encoding mouse mastocytoma IdoA 2-O-sulphotransferase
resulted in an approx. 6-fold increase in O-sulphotransferase activity, compared
with control cells, as determined using O-desulphated heparin as an acceptor.
Structural analysis of endogenous heparan sulphate in the transfected cells,
following metabolic labelling with either [(3)H]GlcN or [(35)S]sulphate, showed
appreciable formation of -GlcA(2-OSO(3))-GlcNSO(3)- disaccharide units (6% of
total disaccharide units; 17% of total O-sulphated disaccharide units) that were
essentially absent from heparan sulphate from control cells. The increase in GlcA
2-O-sulphation was accompanied by a decrease in the amount of IdoA formed,
whereas overall 2-O-sulphation or 6-O-sulphation remained largely unaffected.
These findings indicate that 2-O-sulphation of IdoA and GlcA residues is
catalysed by the same enzyme in heparan sulphate biosynthesis.
PMID- 10677368
TI - Tandem mass spectrometric analysis of aspergillus niger pectin methylesterase:
mode of action on fully methyl-esterified oligogalacturonates.
AB - The substrate specificity and the mode of action of Aspergillus niger pectin
methylesterase (PME) was determined using both fully methyl-esterified
oligogalacturonates with degrees of polymerization (DP) 2-6 and chemically
synthesized monomethyl trigalacturonates. The enzymic activity on the different
substrates and a preliminary characterization of the reaction products were
performed by using high-performance anion-exchange chromatography at neutral pH.
Electrospray ionization tandem MS (ESI-MS/MS) was used to localize the methyl
esters on the (18)O-labelled reaction products during the course of the enzymic
reaction. A. niger PME is able to hydrolyse the methyl esters of fully methyl
esterified oligogalacturonates with DP 2, and preferentially hydrolyses the
methyl esters located on the internal galacturonate residues, followed by
hydrolysis of the methyl esters towards the reducing end. This PME is unable to
hydrolyse the methyl ester of the galacturonate moiety at the non-reducing end.
PMID- 10677366
TI - Involvement of Gialpha2 in sodium butyrate-induced erythroblastic differentiation
of K562 cells.
AB - The chronic myelogenous leukaemia cell line K562 can be triggered in culture to
differentiate along the erythrocytic pathway in response to a variety of
stimulatory agents. In the presence of sodium butyrate, these cells differentiate
to erythroblasts and acquire the capability to synthesize haemoglobin. We used
this cell system to study alterations in the levels of several G-protein subunits
during the cell differentiation programme and to assess the involvement of
G(i)alpha2 in this process. Western immunoblot analysis revealed the presence of
G(s)alpha1, G(s)alpha2, G(i)alpha2, G(q)alpha, Galpha(12), Gbeta1 and Gbeta2 in
K562 cells. G(o)alpha, G(z)alpha, Galpha(13) and Galpha(16) were not detected.
Although the levels of several G-protein subunits were altered after treatment
with sodium butyrate, the most striking change was the robust increase in the
levels of G(i)alpha2, which was accompanied by an increase in the mRNA for
G(i)alpha2. Inactivation of G(i)alpha2 by adding Bordetella pertussis toxin to
the cultures inhibited erythroblastic differentiation by as much as 62%, as
measured by haemoglobin accumulation. Furthermore, the addition of an
oligonucleotide anti-sense to G(i)alpha2 inhibited the sodium butyrate-induced
robust increase in G(i)alpha2 levels, decreasing it to the basal levels seen in
control cells; this treatment decreased the erythroblastic differentiation of the
cells (as measured by haemoglobin expression) by 50%. Taken together, these
findings imply that increased levels of G(i)alpha2 contribute to the sodium
butyrate-induced erythroblastic differentiation of K562 cells.
PMID- 10677369
TI - Cloning and functional characterization of the 5'-flanking region of human
methionine adenosyltransferase 1A gene.
AB - Methionine adenosyltransferase (MAT) is an essential cellular enzyme which
catalyses the formation of S-adenosylmethionine, the principal methyl donor and
precursor for polyamines. In mammals, two different genes, MAT1A and MAT2A,
encode for liver-specific and non-liver-specific MAT respectively. We previously
described a switch in the MAT expression from MAT1A to MAT2A in human liver
cancer, which offered the cancerous cell a growth advantage. Loss of MAT1A
expression was due to lack of gene transcription. To study regulation of the
MAT1A gene, we have cloned and characterized a 1.9 kb 5'-flanking region of the
human MAT1A gene. One transcriptional start site, located 25 nt downstream from a
consensus TATA box, was identified by primer extension and RNase protection
assays. The promoter contains several consensus binding sites for CAAT enhancer
binding protein (C/EBP) and hepatocyte-enriched nuclear factor (HNF),
transcriptional factors important in liver-specific gene expression. The human
MAT1A promoter was able to efficiently drive luciferase expression in Chang
cells, a human liver cell line, but not in HeLa cells. Sequential deletion
analysis of the promoter revealed two DNA regions upstream of the translational
start site, -705 to -839 bp and -1111 to -1483 bp, which are involved in positive
and negative gene regulation, respectively. Specific protein binding to these
regions was confirmed by electrophoretic-mobility-shift and DNase I footprinting
assays. Similar to the situation with the rat MAT1A, glucocorticoid treatment
also increased human MAT1A expression and promoter activity in a dose- and time
dependent manner.
PMID- 10677370
TI - The N-terminal 34 residues of the 55 kDa regulatory subunits of phosphoinositide
3-kinase interact with tubulin.
AB - There are five regulatory subunit isoforms of phosphoinositide 3-kinase (PI 3
kinase), which are classified into three groups: proteins of 85 kDa (p85alpha and
p85beta), 55 kDa (p55alpha and p55gamma) and 50 kDa (p50alpha). Structural
differences between the three groups reside in the N-terminus. To elucidate the
unique functional role of the 55 kDa regulatory subunits, GST (glutathione S
transferase) fusion proteins containing a unique N-terminal portion consisting of
a 34-amino-acid sequence of p55alpha or p55gamma (GST-p55alpha/gammaN(1-34)) were
used as affinity matrices to screen rat brain cell extracts for proteins to which
this portion binds specifically. A protein that bound was identified as beta
tubulin by protein sequencing. In addition, not only the beta isoform of tubulin,
but also the alpha and gamma isoforms, were detected in the protein absorbed from
cell lysates with GST-p55gammaN(1-34) and GST-p55alphaN(1-34) by immunoblotting.
Indeed, the only regulatory subunit present in the purified microtubule assembly
from rat brain was the 55 kDa isoform; neither 85 kDa nor 50 kDa subunits were
detected. These results indicate endogenous binding of 55 kDa regulatory subunits
of PI 3-kinase to tubulin in the brain. Finally, we measured tubulin-associated
PI 3-kinase activity in CHO/IR cells overexpressing each of the five regulatory
subunit isoforms. Only in cells expressing p55alpha or p55gamma was there a
significant elevation of tubulin-associated PI 3-kinase activity in response to
insulin. These results suggest that the p55alpha and p55gamma regulatory subunits
have important roles in regulating PI 3-kinase activity, particularly for
microtubules at the cell periphery.
PMID- 10677371
TI - Vitamin C protects against and reverses specific hypochlorous acid- and
chloramine-dependent modifications of low-density lipoprotein.
AB - Activated phagocytes produce the highly reactive oxidant hypochlorous acid (HOCl)
via the myeloperoxidase-catalysed reaction of hydrogen peroxide with chloride
ions. HOCl reacts readily with a number of susceptible targets on apolipoprotein
B-100 of low-density lipoprotein (LDL), resulting in uncontrolled uptake of HOCl
modified LDL by macrophages. We have investigated the effects of vitamin C
(ascorbate), an effective water-soluble antioxidant, on the HOCl- and chloramine
dependent modification of LDL. Co-incubation of vitamin C (25-200 microM) with
LDL resulted in concentration-dependent protection against HOCl (25-200 microM)
mediated oxidation of tryptophan and lysine residues, formation of chloramines
and increases in the relative electrophoretic mobility of LDL. Vitamin C also
partially protected against oxidation of cysteine residues by HOCl, and fully
protected against oxidation of these residues by the low-molecular-mass
chloramines, N(alpha)-acetyl-lysine chloramine and taurine chloramine, and to a
lesser extent monochloramine (each at 25-200 microM). Further, we found that HOCl
(25-200 microM)-dependent formation of chloramines on apolipoprotein B-100 was
fully reversed by 200 microM vitamin C; however, the loss of lysine residues and
increase in relative electrophoretic mobility of LDL were only partially
reversed, and the loss of tryptophan and cysteine residues was not reversed. Time
course experiments showed that the reversal by vitamin C of HOCl-dependent
modifications became less efficient as the LDL was incubated for up to 4 h at 37
degrees C. These data show that vitamin C not only protects against, but also
reverses, specific HOCl- and chloramine-dependent modifications of LDL. As HOCl
mediated LDL modifications have been strongly implicated in the pathogenesis of
atherosclerosis, our data indicate that vitamin C could contribute to the anti
atherogenic defence against HOCl.
PMID- 10677372
TI - GTPase mechanism and function: new insights from systematic mutational analysis
of the phosphate-binding loop residue Ala30 of Rab5.
AB - Structural and biochemical data indicate the importance of the phosphate-binding
loop residues Gly(12) and Gly(13) of Ras both in the GTP hydrolysis reaction and
in biological activity, but these two residues are not conserved in other Ras
related GTPases. To gain a better understanding of this region in GTP hydrolysis
and GTPase function, we used the Ras-related Rab5 GTPase as a model for
comparison, and substituted the Ala(30) residue (the equivalent of Gly(13) of
Ras) with all the other 19 amino acids. The resulting mutants were analysed for
GTP hydrolysis, GTP binding, GTP dissociation and biological activity. Only the
substitution of alanine with proline reduced the GTPase activity by an order of
magnitude. This effect is in sharp contrast with the observation that a proline
substitution at the neighbouring position (Gly(12) of Ras) has little effect on
the GTPase activity. Whereas most other substitutions showed either a small
negative effect or no effect on the GTPase activity, the arginine substitution
surprisingly stimulated the GTPase activity by 5-fold. Molecular modelling
suggests that this built-in arginine mimics the catalytic arginine residues found
in trimeric GTPases and GTPase-activating proteins in providing the positive
charge to facilitate the GTP hydrolysis reaction. We investigated further the
biological activity of the Rab5 mutants in relation to stimulating endocytosis.
When expressed in cultured baby hamster kidney cells, both arginine and proline
mutants, like wild-type Rab5, stimulated endocytosis. However, the arginine
mutant was a more potent stimulator than the proline mutant (3-fold stimulation
as against 1.7-fold). The tryptophan mutant, on the other hand, was completely
deficient in activity in terms of the stimulation of endocytosis, demonstrating
the importance of the phosphate-binding loop in Rab GTPase function.
PMID- 10677373
TI - Mutations in the reduced-folate carrier affect protein localization and
stability.
AB - The reduced-folate-carrier (rfc) gene has been shown to be functionally important
for reduced-folate transport in mammalian cells. In the present paper we describe
the identification of alterations in both alleles of the rfc gene in a mutant
Chinese-hamster ovary cell line deficient in methotrexate transport. One allele
of the rfc gene contains a point mutation resulting in a Gly(345)-->Arg
substitution in the predicted amino acid sequence. In this case, a protein of
similar size to the wild-type protein is produced, although it remains as an
immature, core-glycosylated, form. The second allele contains a point mutation in
the last base of intron 5 that results in the utilization of a cryptic splice
site leading to a seven-base deletion in the mRNA. The use of an alternate splice
site changes the reading frame to yield a truncated protein with 68 different C
terminal amino acids as compared with the wild-type. Both of these altered gene
products were monitored by fusion with green fluorescent protein and found to be
non-functional with an increased rate of turnover. The protein with the point
mutation is trapped in the endoplasmic reticulum with subsequent degradation,
whereas the product of the splice mutation is not membrane-associated and is
partially degraded. Thus mutations in both alleles of the rfc gene in this
resistant cell line account for the loss of reduced-folate transport. The
observations made regarding the degradation of these mutant gene products also
provide support for putative checkpoints in the endoplasmic reticulum.
PMID- 10677374
TI - Crystal structure of the anti-(carcinoembryonic antigen) single-chain Fv antibody
MFE-23 and a model for antigen binding based on intermolecular contacts.
AB - MFE-23 is the first single-chain Fv antibody molecule to be used in patients and
is used to target colorectal cancer through its high affinity for
carcinoembryonic antigen (CEA), a cell-surface member of the immunoglobulin
superfamily. MFE-23 contains an N-terminal variable heavy-chain domain joined by
a (Gly(4)Ser)(3) linker to a variable light-chain (V(L)) domain (kappa chain)
with an 11-residue C-terminal Myc-tag. Its crystal structure was determined at
2.4 A resolution by molecular replacement with an R(cryst) of 19.0%. Five of the
six antigen-binding loops, L1, L2, L3, H1 and H2, conformed to known canonical
structures. The sixth loop, H3, displayed a unique structure, with a beta-hairpin
loop and a bifurcated apex characterized by a buried Thr residue. In the crystal
lattice, two MFE-23 molecules were associated back-to-back in a manner not seen
before. The antigen-binding site displayed a large acidic region located mainly
within the H2 loop and a large hydrophobic region within the H3 loop. Even though
this structure is unliganded within the crystal, there is an unusually large
region of contact between the H1, H2 and H3 loops and the beta-sheet of the V(L)
domain of an adjacent molecule (strands DEBA) as a result of intermolecular
packing. These interactions exhibited remarkably high surface and electrostatic
complementarity. Of seven MFE-23 residues predicted to make contact with antigen,
five participated in these lattice contacts, and this model for antigen binding
is consistent with previously reported site-specific mutagenesis of MFE-23 and
its effect on CEA binding.
PMID- 10677375
TI - Interaction between the homeodomain proteins Cdx2 and HNF1alpha mediates
expression of the lactase-phlorizin hydrolase gene.
AB - Lactase-phlorizin hydrolase is a brush-border enzyme which is specifically
expressed in the small intestine where it hydrolyses lactose, the main
carbohydrate found in milk. We have previously demonstrated in transgenic mice
that the tissue-specific and developmental expression of lactase is controlled by
a 1 kb upstream region of the pig lactase gene. Two homeodomain transcription
factors, caudal-related homeodomain protein (Cdx2) and hepatic nuclear factor
1alpha (HNF1alpha), are known to bind to regulatory cis elements in the promoters
for several intestine-specific genes, including lactase, and are present in
mammalian intestinal epithelia from an early stage in development. In the present
study, we examined whether Cdx2 and HNF1alpha physically interact and co
operatively activate transcription from the lactase-phlorizin hydrolase promoter.
We show that the presence of both factors leads to a much higher level of
transcription than the sum of the activation by either factor alone. The N
terminal activation domain of Cdx2 is required for maximal synergy with
HNF1alpha. With the use of pull-down assays, we demonstrate a direct protein
protein interaction between Cdx2 and HNF1alpha. The interaction domain includes
the homeodomain region of both proteins. This is the first demonstration of a
functional interaction between two transcription factors involved in the
activation of a number of intestine-specific genes. Synergistic interaction
between tissue-restricted factors is likely to be an important mechanism for
reinforcing developmental and tissue-specific gene expression within the
intestine.
PMID- 10677376
TI - Rapid replenishment of sphingomyelin in the plasma membrane upon degradation by
sphingomyelinase in NIH3T3 cells overexpressing the phosphatidylinositol transfer
protein beta.
AB - In order to study the in vivo function of the phosphatidylinositol transfer
protein beta (PI-TPbeta), mouse NIH3T3 fibroblasts were transfected with cDNA
encoding mouse PI-TPbeta. Two stable cell lines were isolated (SPIbeta2 and
SPIbeta8) in which the levels of PI-TPbeta were increased 16- and 11-fold
respectively. The doubling time of the SPIbeta cells was about 1.7 times that of
the wild-type (wt) cells. Because PI-TPbeta expresses transfer activity towards
sphingomyelin (SM) in vitro, the SM metabolism of the overexpressors was
investigated. By measuring the incorporation of [methyl-(3)H]choline chloride in
SM and phosphatidylcholine (PtdCho), it was shown that the rate of de novo SM and
PtdCho synthesis was similar in transfected and wt cells. We also determined the
ability of the cells to resynthesize SM from ceramide produced in the plasma
membrane by the action of bacterial sphingomyelinase (bSMase). In these
experiments the cells were labelled to equilibrium (60 h) with [(3)H]choline. At
relatively low bSMase concentrations (50 munits/ml), 50% of [(3)H]SM in wt NIH3T3
cells was degraded, whereas the levels of [(3)H]SM in SPIbeta cells appeared to
be unaffected. Since the release of [(3)H]choline phosphate into the medium was
comparable for both wt NIH3T3 and SPIbeta cells, these results strongly suggest
that breakdown of SM in SPIbeta cells was masked by rapid resynthesis of SM from
the ceramide formed. By increasing the bSMase concentrations to 200 munits/ml, a
50% decrease in the level of [(3)H]SM in SPIbeta cells was attained. During a
recovery period of 6 h (in the absence of bSMase) the resynthesis of SM was found
to be much more pronounced in these SPIbeta cells than in 50% [(3)H]SM-depleted
wt NIH3T3 cells. After 6 h of recovery about 50% of the resynthesized SM in the
SPIbeta cells was available for a second hydrolysis by bSMase. When monensin was
present during the recovery period, the resynthesis of SM in bSMase-treated
SPIbeta cells was not affected. However, under these conditions 100% of the
resynthesized SM was available for hydrolysis. On the basis of these results we
propose that, under conditions where ceramide is formed in the plasma membrane,
PI-TPbeta plays an important role in restoring the steady-state levels of SM.
PMID- 10677377
TI - Plasmodium falciparum-infected red blood cells depend on a functional glutathione
de novo synthesis attributable to an enhanced loss of glutathione.
AB - During the erythrocytic cycle, Plasmodium falciparum is highly dependent on an
adequate thiol status for its survival. Glutathione reductase as well as de novo
synthesis of GSH are responsible for the maintenance of the intracellular GSH
level. The first and rate-limiting step of the synthetic pathway is catalysed by
gamma-glutamylcysteine synthetase (gamma-GCS). Using L-buthionine-(S, R)
sulphoximine (BSO), a specific inhibitor of the gamma-GCS, we show that the
infection with P. falciparum causes drastic changes in the GSH metabolism of red
blood cells (RBCs). Infected RBCs lose GSH at a rate 40-fold higher than non
infected RBCs. The de novo synthesis of the tripeptide was found to be essential
for parasite survival. GSH depletion by BSO inhibits the development of P.
falciparum with an IC(50) of 73 microM. The effect of the drug is abolished by
supplementation with GSH or GSH monoethyl ester. Our studies demonstrate that the
plasmodicidal effect of the inhibitor BSO does not depend on its specificity
towards its target enzyme in the parasite, but on the changed physiological needs
for the metabolite GSH in the P. falciparum-infected RBCs. Therefore the
depletion of GSH is proposed as a chemotherapeutic strategy for malaria, and
gamma-GCS is proposed as a potential drug target.
PMID- 10677378
TI - Modulation of the glutathione S-transferase in Ochrobactrum anthropi: function of
xenobiotic substrates and other forms of stress.
AB - The gluthathione S-transferase gene of the atrazine-degrading bacterium
Ochrobactrum anthropi (OaGST) encodes a single-subunit polypeptide of 201 amino
acid residues (Favaloro et al. 1998, Biochem. J. 335, 573-579). RNA blot analysis
showed that the gene is transcribed into an mRNA of about 800 nucleotides,
indicating a monocistronic transcription of the OaGST gene. The modulation of
OaGST in this bacterium, in the presence of different stimulants, was
investigated. The level of expression of OaGST was detected both by measuring the
mRNA level and by immunoblotting experiments. OaGST is a constitutive enzyme
which is also inducible by several stimulants. In fact, atrazine caused an
increase in the expression of OaGST even at concentrations which had no effect on
growth rates of the bacteria. Moreover, the presence of other aromatic substrates
of this bacterium, such as phenol and chlorophenols, leads to a marked
enhancement in OaGST expression. In this case, the expression of OaGST was
related to growth inhibition and membrane damage caused by these hydrophobic
compounds, and to the adaptive responses of the cell membranes. On the other
hand, toluene and xylene, two aromatic compounds not degradable by this
bacterium, did not induce the OaGST expression. The same was observed for other
stress conditions such as low pH, heat shock, hydrogen peroxide, osmotic stress,
starvation, the presence of aliphatic alcohols or heavy metals. These results
suggest a co-regulation of the OaGST gene by the catabolic pathways of phenols
and chlorophenols in this bacterium. Therefore, OaGST could function as a
detoxifying agent within the catabolism of these xenobiotics.
PMID- 10677379
TI - Autonomic function in normal pregnancy: the role of studying heart rate
variability.
PMID- 10677380
TI - Nitric oxide and the airway.
PMID- 10677381
TI - Identifying genetic susceptibility factors for tuberculosis in Africans: a
combined approach using a candidate gene study and a genome-wide screen.
AB - There is convincing evidence that host genes affect the outcome of infection in
human tuberculosis. Two complementary strategies were used to identify the genes
involved. A linkage-based genome-wide screen was carried out to locate the
positions of genes exerting a major population-wide effect on tuberculosis
susceptibility. A candidate-gene-based case-control study was used to examine the
effects of genes that may exert a more moderate effect on risk of clinical
tuberculosis. The genome screen was conducted in two stages. In the first stage
299 microsatellite markers, spanning all 23 chromosomes, were typed in 92
independent sib-pairs, and seven regions showed some evidence of co-segregation
with the disease. These seven regions were examined in a second set of 81 sib
pairs, and markers on chromosomes 15q and Xq showed evidence of linkage to
tuberculosis. An X chromosome susceptibility gene may contribute to the excess of
males with tuberculosis observed in many populations. The candidate gene approach
compared the frequency of polymorphisms in several genes in over 400 subjects
with smear-positive pulmonary tuberculosis and 400 ethnically matched healthy
controls. Polymorphisms in genes encoding natural-resistance-associated
macrophage protein, vitamin D receptor and mannose-binding lectin were associated
with tuberculosis. These results suggest that many genes may be involved in
determining host susceptibility to tuberculosis, and highlight the importance of
using several different study methods to locate them.
PMID- 10677382
TI - Genetic analysis of the atrial natriuretic peptide gene in essential
hypertension.
AB - Atrial natriuretic peptide (ANP) plays an important role in the regulation of
blood pressure through sodium-water homoeostasis. Accordingly, several
investigators have raised the question of whether the gene encoding ANP is
involved in the aetiology of essential hypertension or related phenotypes such as
salt sensitivity. Most of the studies have used anonymous polymorphic markers of
the gene, and made inconclusive claims about the disease relevance of ANP.
Therefore, in order to find sequence variations with potential functional
significance and to characterize the pattern of linkage disequilibrium between
polymorphisms, we screened a 3368-bp genomic fragment of ANP. Subsequently we
tested the association of detected polymorphisms with plasma ANP levels and with
hypertension status. Two new polymorphisms were identified, in the 5'
untranslated region and exon 1 respectively, as well as three previously reported
polymorphisms in intron 2 and exon 3. When analysed in 102 healthy normotensive
subjects, none of the polymorphisms appeared to significantly affect plasma ANP
levels. A case-control study in a Japanese population (255 hypertensive and 225
normotensive individuals) revealed a marginally significant association (P=0.026)
between an ANP polymorphism located in the 5'-untranslated region (C-664G) and
hypertension, but no association for the other polymorphisms. Each of the
uncommon variants has an allele frequency of less than 10% in Japanese people,
which may have hampered our detection of a significant association between ANP
variants and hypertension status (and plasma ANP levels). The pathophysiological
relevance of ANP, however, needs to be further defined in relation to
hypertension-associated phenotypes, and also should be examined in different
ethnic groups.
PMID- 10677383
TI - Changes in baroreceptor sensitivity for heart rate during normotensive pregnancy
and the puerperium.
AB - Normal pregnancy is associated with marked changes in cardiovascular
haemodynamics, which in part may be due to changes in autonomic control
mechanisms. Baroreflex sensitivity for heart rate (BRS) was calculated in the
supine and standing positions using power spectral analysis of pulse interval
(PI) and systolic blood pressure (SBP) in 16 normotensive pregnant women and 10
normotensive non-pregnant controls. The pregnant women were studied on three
occasions during their pregnancy (early, mid- and late gestation) and once during
the puerperium. Supine total SBP variability increased between early and late
pregnancy by 79% [95% confidence intervals (CI) 30%, 145%; P<0. 001], and supine
high-frequency PI variability decreased by 75% (CI 51%, 88%; P<0.001). Supine BRS
fell by 50% (P<0.001), with values returning to early-pregnancy levels in the
puerperium, which were similar to those recorded in the control group. Standing
SBP variability and BRS values were unchanged during pregnancy and post partum.
The low/high frequency ratio of PI variability, taken as a surrogate measure of
sympathovagal balance, increased by 137% (CI 42%, 296%; P<0.01) in the supine but
not the standing position from early to late pregnancy. This was due to a
decrease in high-frequency variability rather than to an increase in low
frequency variability, suggesting that these changes may have been due to vagal
withdrawal rather than increased sympathetic activity. Normotensive pregnancy is
associated with a marked decrease in supine BRS, although the exact mechanisms
for these changes remain unclear. Further studies are required to define whether
changes in BRS and sympathovagal tone in early pregnancy can be used to predict
the onset of pregnancy-induced hypertension.
PMID- 10677384
TI - Antihypertensive treatment in early postnatal life modulates prenatal dietary
influences upon blood pressure in the rat.
AB - Epidemiological evidence from diverse human populations, supported by
experimental evidence from animal models, suggests that maternal nutrition during
pregnancy is an important fetal programming influence upon cardiovascular
disease. Experiments with a low-protein-diet model of rat pregnancy suggest a
role for the renin-angiotensin system in the programming mechanism, since fetal
undernutrition permanently elevates pulmonary and plasma angiotensin-converting
enzyme activity. Long-term beneficial effects of captopril on blood pressure in
this model require further investigation in order to clarify the role of
angiotensin II. Pregnant rats were fed a control diet containing 18% (w/w) casein
as the protein source or a low-protein diet containing 9% (w/w) casein. Between
the ages of 2 and 4 weeks postnatally, mothers and their pups were treated with
losartan or nifedipine. All pups in the study had blood pressure determined at 4
and 12 weeks of age using a tail cuff. Animals exposed to the low-protein diet in
utero and not subjected to drug treatment had elevated blood pressure relative to
control rats (mean increase of 27 mmHg; P<0.001). Treatment of rats exposed to
the control diet in utero with either nifedipine or losartan between 2 and 4
weeks of age did not alter their blood pressure. Nifedipine had no effect upon
the blood pressure of low-protein-exposed pups, but losartan prevented the blood
pressure elevation in these animals. Between 4 and 12 weeks of age, blood
pressure increased significantly in all groups (P<0.001). The pattern of blood
pressure among the groups was identical to that observed at 4 weeks, suggesting
that the observed early effects of losartan would be maintained into adult life.
The data are consistent with the hypothesis that angiotensin II plays a major
role in the prenatal programming of hypertension. The action of angiotensin II at
the AT(1) receptor between 2 and 4 weeks of age may be critically up-regulated by
fetal factors, including exposure to glucocorticoids of maternal origin.
PMID- 10677385
TI - Cytochrome P450 metabolites of arachidonic acid may be important mediators in
angiotensin II-induced vasoconstriction in the rat mesentery in vivo.
AB - We have investigated the role of cytochrome P450 (CYP-450) metabolites of
arachidonic acid in the modulation of vascular reactivity to angiotensin II in
vivo using an in situ blood-perfused mesenteric preparation in anaesthetized
spontaneously hypertensive rats (SHR). Miconazole, a non-selective inhibitor of
CYP-450 that inhibits both hydroxylation and epoxidation, substantially
suppressed mesenteric vasoconstrictor responses to angiotensin II in SHR, but had
no effect on responses to noradrenaline or sympathetic nerve stimulation. In
normotensive Wistar-Kyoto (WKY) rats, miconazole caused only a modest suppression
of vasoconstrictor responses to angiotensin II. N-Methylsulphonyl-12, 12
dibromododec-11-enamide (DDMS), a new selective inhibitor of CYP-450 omega
hydroxylase activity, decreased mean intra-arterial blood pressure and
significantly attenuated mesenteric angiotensin II-induced vasoconstrictor
responses in SHR. Isolated mesenteric vessels were able to metabolize (14)C
labelled arachidonic acid to hydroxyeicosatetraenoic acids (HETEs) in vitro, and
this was substantially inhibited by DDMS. The results from the present studies
combined with the existing evidence that angiotensin II stimulates the release of
20-HETE, a CYP-450 metabolite of arachidonic acid, suggest that CYP-450-derived
HETEs may be important mediators in angiotensin II-induced vasoconstriction.
However, the development of more sensitive assays for the detection in vivo of 20
HETE in mesenteric vessels would be required to confirm these findings.
PMID- 10677386
TI - Effects of proinsulin C-peptide on nitric oxide, microvascular blood flow and
erythrocyte Na+,K+-ATPase activity in diabetes mellitus type I.
AB - This study was conducted to evaluate the influence of proinsulin C-peptide on
erythrocyte Na(+),K(+)-ATPase and endothelial nitric oxide synthase activities in
patients with type I diabetes. In a randomized double-blind study design, ten
patients with type I diabetes received intravenous infusions of either human C
peptide or physiological saline on two different occasions. C-peptide was infused
at a rate of 3 pmol.min(-1).kg(-1) for 60 min, and thereafter at 10 pmol.min(
1).kg(-1) for 60 min. At baseline and after 60 and 120 min, laser Doppler flow
(LDF) was measured following acetylcholine iontophoresis or mild thermal
stimulation (44 degrees C), and venous blood samples were collected to determine
plasma cGMP levels and erythrocyte membrane Na(+),K(+)-ATPase activity. The LDF
response to acetylcholine increased during C-peptide infusion and decreased
during saline infusion [18.6+/-19.2 and -13.2+/-9.4 arbitrary units respectively;
mean+/-S.E.M.; P<0.05). No significant change in LDF was observed after thermal
stimulation. The baseline plasma concentration of cGMP was 5.5+/-0.6 nmol.l(-1);
this rose to 6.8+/-0.9 nmol.l(-1) during C-peptide infusion (P<0.05). Erythrocyte
Na(+),K(+)-ATPase activity increased from 140+/-29 nmol of P(i).h(-1).mg(-1) in
the basal state to 287+/-5 nmol of P(i). h(-1).mg(-1) during C-peptide infusion
(P<0.01). There was a significant linear relationship between plasma C-peptide
levels and erythrocyte Na(+),K(+)-ATPase activity during the C-peptide infusion
(r=0.46, P<0.01). No significant changes in plasma cGMP levels or Na(+),K(+)
ATPase activity were observed during saline infusion. This study demonstrates an
effect of human proinsulin C-peptide on microvascular function, which might be
mediated by an increase in NO production and an activation of the erythrocyte
Na(+),K(+)-ATPase. These mechanisms are compatible with the previous observed
microvascular effects of C-peptide in patients with type I diabetes.
PMID- 10677387
TI - Role of nitric oxide in airway remodelling.
AB - Airway remodelling, which is manifested by thickening of bronchial wall, is an
important causative factor of bronchial hyper-responsiveness in asthma. The
pathophysiological mechanism of airway remodelling is not clear. In the present
study we evaluated the relationship between nitric oxide (NO) generation and
airway wall thickening in patients with chronic asthma. As a marker of NO
production, the levels of nitrite/nitrate were measured in induced sputum, and
bronchial wall thickening was measured by high-resolution computed tomography.
Sputum concentrations of nitrite/nitrate were significantly increased in
asthmatic patients compared with controls. The ratio of airway wall thickness to
lumen diameter was significantly correlated with the sputum concentration of
nitrite/nitrate. Although statistical correlation does not prove causation, this
finding suggests that NO may play a key role in the pathogenesis of airway
remodelling.
PMID- 10677388
TI - Albumin stimulates p44/p42 extracellular-signal-regulated mitogen-activated
protein kinase in opossum kidney proximal tubular cells.
AB - The presence of protein in the urine of patients with renal disease is an adverse
prognostic feature. It has therefore been suggested that proteinuria per se may
be responsible for the development of renal tubulo-interstitial scarring and
fibrosis, and disturbances in tubular cell growth and proliferation. We have used
the opossum kidney proximal tubular cell line to investigate the effects of
albumin on cell growth. The effect of albumin on cell proliferation was
investigated by cell counting and measurement of [(3)H]thymidine incorporation.
We studied the effect of recombinant human albumin on the activity of p44/p42
extracellular-signal-regulated mitogen-activated protein kinase (MAP kinase )
using an in vitro kinase assay, and immunoblotting with antibodies against active
extracellular-signal-regulated kinase (ERK). The effects of the ERK inhibitor
PD98059 were also examined. Recombinant human albumin was found to stimulate
proliferation of opossum kidney cells in a dose-dependent manner, with maximal
stimulation at a concentration of 1 mg/ml. In addition, recombinant human albumin
activated ERK in a time-dependent (maximal after 5 min) and dose-dependent
(maximal at 1 mg/ml) fashion. These effects on cell proliferation and ERK
activity were inhibited by PD98059, and were not reproduced by ovalbumin or
mannitol. The data therefore indicate that albumin is able to stimulate growth
and proliferation of proximal tubular cells that is dependent on the ERK family
of MAP kinases. The potential importance of this pathway in the development of
renal disease is discussed.
PMID- 10677389
TI - Effects of adenosine receptor antagonists on the responses to contrast media in
the isolated rat kidney.
AB - Contrast media can induce both a decrease in renal blood flow and a reduction in
glomerular filtration rate (GFR) when administered to both experimental animals
and humans. In the present study we have examined the role of adenosine in
mediating these effects using the isolated perfused rat kidney. Kidneys were
perfused with a 6. 7%-(w/v)-albumin-based perfusate supplemented with glucose and
amino acids (n=6 per group). They were exposed to diatrizoate [20 mg of iodine
(mgI)/ml; osmolality 1650 mOsm/kg of water] or iotrolan (20 mgI/ml; osmolality
320 mOsm/kg of water) in the presence or absence of theophylline (10.8
microg/ml), or to diatrizoate in the presence or absence of a specific adenosine
A(1) receptor antagonist (KW-3902; 2 microg/ml) or a specific A(2) receptor
antagonist (KF17837; 6 microg/ml). Diatrizoate (n=6) produced a fall in GFR from
0.65+/-0.04 to 0.42+/-0.03 ml.min(-1).g(-1) (P<0.05); renal perfusate flow (RPF)
also declined, from 36.5+/-3.8 to 22.0+/-3.2 ml. min(-1).g(-1) (P<0.05). Iotrolan
(n=6) produced a fall in GFR from 0. 64+/-0.02 to 0.48+/-0.04 ml.min(-1).g(-1)
(P<0.05) and in RPF from 33.3+/-3.8 to 24.0+/-3.0 ml.min(-1).g(-1) (P<0.05).
Theophylline (10.8 microg/ml) prevented the fall in GFR caused by either
diatrizoate (baseline, 0.63+/-0.05 ml.min(-1).g(-1); diatrizoate+theophylline, 0.
60+/-0.04 ml.min(-1).g(-1)) or iotrolan (baseline, 0.64+/-0.04 ml. min(-1).g(-1);
iotrolan+theophylline, 0.67+/-0.05 ml.min(-1).g(-1)), but did not affect the
decreases in RPF caused by either agent. KW-3902 (2 microg/ml) also prevented the
fall in GFR produced by diatrizoate (baseline, 0.66+/-0.05 ml.min(-1).g(-1);
diatrizoate+KW-3902, 0.61+/-0.05 ml.min(-1).g(-1)), while the fall in RPF
remained unaffected. KF17837 (6 microg/ml) had no effect on the decreases in
either GFR or RPF induced by diatrizoate (n=6 per group). The results suggest a
role for adenosine acting at the A(1) receptor in mediating the decrease in GFR
induced by contrast media. This effect is independent of a change in renal
vascular resistance, and possibly secondary to mesangial cell contraction causing
a decrease in the ultrafiltration coefficient.
PMID- 10677390
TI - Does a high concentration of calcium in the urine cause an important renal
concentrating defect in human subjects?
AB - The objective of this study was to evaluate the hypothesis that a high
concentration of ionized calcium in the lumen of the medullary collecting duct
causes an osmole-free water diuresis. The urine flow rate and osmolality were
measured in normal human subjects, as well as in patients with a history of
nephrolithiasis who excreted more than 5 mmol of calcium per 24 h. There was an
inverse relationship between the concentration of calcium in the urine and the 24
h urine volume both in normal subjects and in patients with a history of
nephrolithiasis. When the concentration of calcium in the urine was greater than
5 mmol/l, the urine volume was less than 1 litre per day in the majority of
subjects. After 16 h of water deprivation, when the concentration of calcium in
the urine was as high as 17 mmol/l (ionized calcium 7.4 mmol/l), urine osmolality
was 1258 mOsm/kg of water and the urine flow rate was 0.30 ml/min. We conclude
that, although a calcium receptor may be present in the lumen of the medullary
collecting duct in human subjects, an extremely high concentration of urinary
total and ionized calcium does not cause a clinically important defect in the
renal concentrating process.
PMID- 10677391
TI - Myocardial tissue oxygen supply and utilization during coronary artery bypass
surgery: evidence of microvascular no-reflow.
AB - The supply and utilization of oxygen by the myocardium reflect the dynamic
efficiency of the microcirculation. The present study examines these parameters
during coronary artery bypass surgery. We used a voltammetric microelectrode
technique to assess regional variations in myocardial tissue partial pressure of
oxygen (PO(2)) and myocardial tissue perfusion (MTP) in patients undergoing
coronary artery bypass surgery. A total of 29 myocardial regions were studied in
17 patients to assay tissue PO(2), and 13 regions in 10 patients to measure MTP.
There was an increase in MTP from 53+/-9 ml.min(-1).100 g(-1) before
cardiopulmonary bypass to 72+/-13 ml. min(-1).100 g(-1) after (means+/-S.E.M.;
P=0.05). Tissue PO(2) showed an overall increase from a baseline level of 45+/-8
mmHg to a final level of 88+/-10 mmHg (P<0.0001). Following release of the aortic
cross-clamp there was a variable time delay before a change in tissue PO(2) was
observed. There was an immediate response in five regions, whereas in 20 regions
the response was delayed by between 0.5 and 32 min. In the remaining four regions
there was no change in tissue PO(2). The duration of the delay in response was
correlated positively with the cross-clamp time (r=0.45, P<0.05) and negatively
with the final tissue PO(2) (r=-0.5, P<0.05). Voltammetric methods for monitoring
changes in oxygen supply and utilization offer new insights into the changes that
occur during ischaemia and reperfusion. A delay in the delivery of oxygen to the
myocardium occurs in many patients following coronary artery bypass surgery.
PMID- 10677392
TI - Effects of prolonged hypobaric hypoxia on human skeletal muscle function and
electromyographic events.
AB - This study tested the hypothesis that a prolonged decrease in arterial oxygen
pressure in resting or contracting skeletal muscles alters their ability to
develop force through an impairment of energy-dependent metabolic processes and
also through an alteration of electrophysiological events. The experiment was
conducted during a 32-day simulated ascent of Mt. Everest (8848 m altitude)
(Everest III Comex '97), which also allowed testing of the effects of re
oxygenation on muscle function. Maximal voluntary contractions (MVCs) of the
flexor digitorum, and static handgrips sustained at 60% of MVC, were performed by
eight subjects before the ascent (control), then during the stays at simulated
altitudes of 5000 m, 6000 m and 7000 m, and finally 1 day after the return to 0
m. The evoked muscle compound action potential (M-wave) was recorded at rest and
during the manoeuvres at 60% of MVC. The changes in median frequency of
electromyographic (EMG) power spectra were also studied during the contraction at
60% of MVC. In four individuals, transient re-oxygenation during the ascent
allowed us to test the reversibility of hypoxia-induced MVC and M-wave changes.
At rest, a significant decrease in M-wave amplitude was noted at 5000 m. This
effect was associated with a prolonged M-wave conduction time at 6000 m and an
increased M-wave duration at 7000 m, and persisted after the return to 0 m. Re
oxygenation did not modify the changes in M-wave characteristics. A significant
decrease in MVC was measured only during the ascent (-10 to -24%) in the non
dominant forearm of subjects who underwent re-oxygenation; this intervention
slightly improved muscle strength at 6000 m and 7000 m. During the ascent and
after the return to 0 m, there was a significant reduction of the median
frequency decrease throughout contraction at 60% of MVC compared with the EMG
changes measured before the ascent. It is concluded that prolonged exposure to
hypoxia slows the propagation of myopotentials and alters sensorimotor control
during sustained effort. Re-oxygenation did not affect the hypoxia-induced EMG
changes and had a modest influence on muscle strength.
PMID- 10677393
TI - Deleterious effects of chronic clenbuterol treatment on endurance and sprint
exercise performance in rats.
AB - The beta(2)-adrenergic agonist, clenbuterol, has powerful muscle anabolic and
lipolytic effects and is used by athletes to improve exercise performance;
however, its use in conjunction with different forms of exercise training has
received limited attention. Since previous studies have reported that chronic use
of other beta(2)-adrenergic agonists has deleterious effects on cardiac muscle
structure and function, the aim of the present study was to determine whether
chronic clenbuterol administration would reduce the exercise capabilities of rats
subjected to long-term treadmill sprint running, endurance swimming or voluntary
wheel running training. The effect of clenbuterol treatment on exercise
performance in rats was evaluated in three separate studies. Different groups of
male rats were assigned to an endurance swimming (2 h/day, 5/7 days, 18 weeks)
group, a treadmill sprint running (8x1 min bouts, 1.05 m/s, 20 weeks) group, or a
voluntary wheel running (16 weeks) group. In each study, rats were allocated into
either a treated group that received clenbuterol (2 mg.kg(-1).day(-1)) in their
drinking water or an untreated control group. In each of the three studies,
treated rats exhibited a reduction in exercise performance compared with
untreated rats. Treated rats ran approximately 57% less total distance than
untreated rats in the voluntary running programme and were unable to complete the
swimming and sprinting protocols performed by the untreated rats. In each of the
studies, the treated rats exhibited cardiac hypertrophy, with absolute heart mass
increased by approximately 19% and heart mass relative to body mass increased by
approximately 20%. The hearts of sedentary rats treated with clenbuterol
exhibited extensive collagen infiltration surrounding blood vessels and in the
wall of the left ventricle. The results indicate strongly that chronic
clenbuterol administration deleteriously affects exercise performance in rats,
potentially due to alterations in cardiac muscle structure and function.
PMID- 10677394
TI - Effects of pre- and post-absorptive factors on the lactulose/rhamnose gut
permeability test.
AB - It is assumed that the outcome of the lactulose/rhamnose gut permeability test is
not influenced by pre- or post-absorptive factors. The aim of our study was to
investigate the role of a pre-absorptive factor, i.e. small-intestinal transit,
and a post-absorptive factor, i.e. renal clearance. Ten healthy male subjects
were studied. Urinary lactulose and rhamnose excretion was measured after
intraduodenal administration of lactulose and rhamnose following induction of
increased intestinal permeability using chenodeoxycholic acid (chenodiol), in the
absence and in the presence of accelerated intestinal transit. Urinary sugar
excretion was measured after intravenous administration of either a regular dose
(50 mg/50 mg) or a high dose (250 mg/250 mg) of lactulose/rhamnose. The
intraduodenal experiments showed that a combination of accelerated small-bowel
transit and increased permeability did not lead to significant differences in the
recovery of lactulose (P=0.647) or rhamnose (P=0.889), or in the
lactulose/rhamnose ratio, compared with those under conditions of increased
permeability alone (P=0.68). However, lactulose recovery was significantly lower
(P=0.025) after intravenous administration of a high dose of the sugars. There
was no significant difference in urinary rhamnose recovery (P=0.575) between the
high and the regular doses. This resulted in a significantly lower
lactulose/rhamnose ratio (P=0.021) after intravenous administration of a high
dose, compared with a regular dose, of the sugars. In conclusion, the assumption
that post-absorptive processes do not influence the outcome of the
lactulose/rhamnose permeability test appears not to be valid.
PMID- 10677395
TI - Low paraoxonase activity in type II diabetes mellitus complicated by retinopathy.
AB - Human serum paraoxonase 1 (PON1) is located on high-density lipoprotein and has
been implicated in the detoxification of organophosphates, and possibly in the
prevention of lipid peroxidation of low-density lipoprotein. PON1 has two genetic
polymorphisms, both due to amino acid substitutions: one involving glutamine (Q
genotype) and arginine (R genotype) at position 192, and the other involving
leucine (L genotype) and methionine (M genotype) at position 55. We investigated
the effects of these polymorphisms, and of a polymorphism of the PON2 gene at
position 310 (Cys/Ser; C and S genotypes respectively), on serum PON1 activity
and concentration, plasma lipids and lipoproteins and glycaemic control in 93
individuals with type II diabetes with no complications and in 101 individuals
with type II diabetes with retinopathy. Serum PON1 activity in the group with no
complications [median 164.1 nmol.min(-1).ml(-1) (range 8.0-467.8)] was
significantly higher than in the group with retinopathy [113.4 nmol. min(-1).ml(
1) (3.0-414.6)] (P<0.001), but the serum PON1 concentration was not different
between the groups. The gene frequencies of the PON1-55 and PON1-192
polymorphisms and of the PON2-310 polymorphism were not different between the
study populations. The PON1-55 and PON1-192 polymorphisms affected PON1 activity
in the way described in a previous study of a control group and subjects with
type II diabetes. The PON2-310 polymorphism also significantly affected serum
PON1. PON1 activity was significantly higher in individuals with the PON2-310 CC
genotype in both groups with type II diabetes, and the PON1 concentration was
significantly higher in PON2-310 CC homozygotes with no complications than in the
group with retinopathy. Neither the PON1-55 nor the PON1-192 polymorphism was
correlated with the serum lipid or lipoprotein concentration in either group. In
the group with retinopathy (but not the group with no complications), all three
PON polymorphisms were correlated with glycaemic control, which was worse for the
PON1-55 genotypes in the order MM>LM>LL (P=0.0032), for the PON1-192 genotypes in
the order RR>QR>QQ (P=0.011) and for the PON2-310 genotypes in the order CC>CS>SS
(P=0.010). Low serum PON1 activity in retinopathy may be related to an increased
tendency for lipid peroxidation. Our findings thus raise the possibility that, in
retinopathy, the PON2 gene may influence PON1, and that an inter-relationship
between the PON1 and PON2 genes may influence glycaemic control in subjects with
type II diabetes complicated by retinopathy.
PMID- 10677396
TI - Percutaneous myocardial laser revascularisation.
PMID- 10677397
TI - Five years of percutaneous transluminal septal myocardial ablation.
PMID- 10677398
TI - Stamps in cardiology. Acupuncture anaesthesia for open heart surgery.
PMID- 10677399
TI - Is there a role for renin profiling in selecting chronic heart failure patients
for ACE inhibitor treatment?
AB - BACKGROUND: It remains uncertain whether angiotensin converting enzyme (ACE)
inhibitors benefit all heart failure patients or just those with renin
angiotensin-aldosterone system (RAAS) activation. OBJECTIVE: To determine whether
the response to an ACE inhibitor, assessed by urine sodium excretion, was
different in patients with low renin versus those with high renin. DESIGN: Plasma
renin activity (PRA) was measured in 38 patients with stable chronic heart
failure (21 male, 17 female; mean (SD) age 71 (6) years, range 59-82 years) on
chronic diuretic treatment alone. They were divided into three groups: low (PRA
= 1.5 ng/ml/h, n = 11); normal (1.5 < PRA < 5, n = 14); and high (PRA > 5, n =
13). The effect of ACE inhibition was then assessed on diuretic induced
natriuresis with respect to renin status. RESULTS: There were no significant
differences in age and sex distribution between the groups. Plasma angiotensin II
and aldosterone increased serially from low to high renin groups, while 24 h
urinary sodium concentrations fell from low to high renin groups (low PRA, 96.7
(39.5); normal PRA, 90.4 (26.7); high PRA, 66. 3 (18.9) mmol/l; p = 0.033),
despite a higher diuretic dose in the high renin group. This blunted natriuretic
effect of loop diuretics was caused by RAAS activation, which could partly be
reversed by ACE inhibition. ACE inhibitors increased natriuresis by 22% in the
high renin group (p = 0.029), but had no effect in the normal and low renin
groups. Within the low renin group, five of the 11 patients had persistently low
renin levels despite ACE inhibition. There was a non-significant reduction in
natriuresis (-9.6%, p = 0.335) following ACE inhibition in this subgroup of
patients. CONCLUSIONS: About one third of heart failure patients in our study had
low renin status and a non-activated RAAS, despite diuretic treatment. ACE
inhibitors did not alter natriuresis significantly in this subgroup of patients,
and enhanced natriuresis only in patients with high renin. There is thus
tentative support for renin profiling in targeting ACE inhibitors to the most
deserving, by showing that short term sodium retention does not occur in low
renin patients if ACE inhibitors are withdrawn.
PMID- 10677400
TI - Images in cardiology. Perivalvar abscess of the mitral valve annulus with
perforation owing to infective endocarditis.
PMID- 10677401
TI - Effect of verapamil on systolic and diastolic coronary blood flow velocity in
asymptomatic and mildly symptomatic patients with hypertrophic cardiomyopathy.
AB - OBJECTIVE: To assess non-invasively the effect of verapamil treatment on coronary
blood flow velocity in asymptomatic and mildly symptomatic patients with
hypertrophic cardiomyopathy. DESIGN: High frequency transthoracic Doppler
echocardiography was used to compare resting phasic coronary blood flow velocity
before and after a one month period of verapamil treatment in 17 patients (14 men
and three women) with non-obstructive hypertrophic cardiomyopathy. Eighteen
healthy subjects formed an age and sex matched control group. Systolic and
diastolic coronary blood flow velocity was measured in the distal portion of left
anterior descending coronary artery using high frequency transthoracic Doppler
echocardiography. Blood flow velocity before and after verapamil was compared in
the patients with cardiomyopathy and with the results in the control group.
RESULTS: Compared with the controls, patients with hypertrophic cardiomyopathy
had increased diastolic coronary blood flow velocity (41.8 (8.1) v 59.9 (21.9)
cm/s, p < 0.01) and a lower mean systolic coronary blood flow velocity (18.7
(10.8) v -11.2 (27.5) cm/s, p < 0. 01) before verapamil treatment. A backward
pattern of systolic flow, manifested by negative values of coronary blood flow
velocity, was recorded in eight of the patients, while no negative values were
found in the controls. After verapamil treatment the retrograde systolic blood
flow was restored to an anterograde pattern in only one patient. The mean value
of systolic coronary blood flow velocity did not change significantly and
remained lower than the systolic forward flow velocity in the controls (-3.6
(31.8) v 18.7 (10.8) cm/s, p < 0.05). However, diastolic coronary blood flow
velocity decreased significantly after verapamil (59.9 (21.9) v 50.7 (19.5) cm/s
p < 0.05), reaching a level comparable with that in the controls (50.7 (19.5) v
41.8 (8.1) cm/s, p > 0.05). CONCLUSIONS: In contrast to healthy subjects, in non
obstructive hypertrophic cardiomyopathy the systolic pattern of coronary blood
flow was heterogeneous (both retrograde and anterograde), and diastolic coronary
blood flow velocity was abnormally increased, despite a lack of significant
symptoms. Verapamil treatment did not restore the forward pattern of systolic
blood flow but decreased diastolic blood flow velocity to a level comparable with
that in healthy subjects.
PMID- 10677402
TI - Racial variation in cardiovascular morbidity and mortality in essential
hypertension.
AB - OBJECTIVES: To perform a longitudinal comparison of morbidity and mortality among
white, south Asian and Afro-Caribbean hypertensive patients in relation to
baseline demographic characteristics and clinic and ambulatory blood pressure
variables. DESIGN: Observational follow up study. SETTING: District general
hospital and community setting in Harrow, England. PATIENTS: 528 white, 106 south
Asian, and 54 Afro-Caribbean subjects with essential hypertension who had
undergone 24 hour ambulatory intra-arterial blood pressure monitoring.
INTERVENTIONS: Follow up for assessment of all cause morbidity and mortality over
a mean (SD) of 9.2 (4.1) years. MAIN OUTCOME MEASURES: Non-cardiovascular death,
coronary death, cerebrovascular death, peripheral vascular death, non-fatal
myocardial infarction, non-fatal stroke, coronary revascularisation. RESULTS:
South Asians had the highest all cause event rate of 3.46, compared with 2.50
(NS) and 0.90 (p = 0.002) events/100 patient-years for whites and Afro
Caribbeans, respectively. This was because of an excess of coronary events (2.86
v 1.32 events/100 patient-years in south Asians v whites, respectively; p =
0.002). Age (p < 0.001), sex (p < 0.001), race (south Asians : whites, hazard
ratio 1.79; p = 0.008), diabetes (p = 0.05), previous history of cardiovascular
disease (p < 0.001), and 24 hour ambulatory systolic blood pressure (p = 0.006)
were independent predictors of time to a first event. Clinic blood pressure did
not provide additional prognostic information. CONCLUSIONS: South Asian origin
was an independent predictor of all cause events, mainly because of an excess of
coronary events in this group. Ambulatory but not clinic blood pressure was of
additional value in predicting subsequent morbidity and mortality.
PMID- 10677403
TI - Blood pressure, arterial compliance, and left ventricular mass: no relation to
small size at birth in south Indian adults.
AB - OBJECTIVE: To determine whether reduced fetal growth leads to raised blood
pressure, reduced arterial compliance, and increased left ventricular mass in an
Indian population. DESIGN: A retrospective cohort study of men and women (age
range 40-61 years) whose weight, length, and head circumference at birth were
recorded. SETTING: The Holdsworth Memorial Hospital, Mysore, South India.
SUBJECTS: 435 men and women born in the hospital between 1934 and 1953. MAIN
OUTCOME MEASURES: Systolic and diastolic blood pressures; compliance in four
arterial segments derived from pulse wave velocity, measured by a non-invasive
optical method; and left ventricular mass measured using M mode echocardiography.
RESULTS: Small size at birth was not associated with increased adult blood
pressure or left ventricular mass, or with reduced arterial compliance. Systolic
blood pressure and left ventricular mass were higher in subjects who were greater
in length at birth, rising by 1.64 mm Hg (95% confidence interval (CI) -0.08 to
+3.37 mm Hg) and 1.63 g/m(2) (95% CI 0.13 to 3.13 g/m(2)), respectively, per one
inch (2.5 cm) increase in birth length, independently of adult size. Arterial
compliance was reduced in people whose mothers were lighter and had smaller
pelvic (external conjugate) diameters. CONCLUSIONS: The higher prevalence of
coronary heart disease in Indian men and women of lower birth weight, shown in an
earlier study of the same cohort, cannot be explained by changes in blood
pressure, arterial compliance, and left ventricular mass. The association of
raised blood pressure and left ventricular mass with longer birth length suggests
that the way in which the intrauterine environment influences coronary heart
disease differs between Indian and Western populations.
PMID- 10677404
TI - Images in cardiology. Growth and the implantable cardioverter defibrillator.
PMID- 10677405
TI - Influence of hypertension, left ventricular hypertrophy, and left ventricular
systolic dysfunction on plasma N terminal proBNP.
AB - OBJECTIVES: To examine the relation between plasma concentration of the N
terminal of the precursor of brain natriuretic peptide (NT proBNP), left
ventricular hypertrophy (LVH), and left ventricular systolic dysfunction (LVSD)
in patients with a history of hypertension. DESIGN: Prospective study. SETTING:
Teaching hospital based study. PATIENTS: NT proBNP concentrations were determined
in five groups of individuals. Group 1: 15 echocardiographic normal controls;
group 2: 22 patients with hypertension, normal left ventricular systolic
function, and no LVH; group 3: 24 patients with hypertension, normal left
ventricular systolic function, and LVH; group 4: 13 patients with history of
hypertension, no history of ischaemic heart disease, and left ventricular wall
motion index (WMI) between 1.9-1.3; and group 5:17 patients with a history of
hypertension, no history of ischaemic heart disease, and WMI < 1.2. RESULTS:
Median (range) NT proBNP concentrations (in fmol/ml) for groups 1-5,
respectively, were: 129.4 (53.6-159.7), 147.4 (54.3-730. 5), 137.1 (35.8-403.9),
356.7 (124.4-934.4), and 493.5 (248.9-909). Mean log NT proBNP differed among all
five groups (p < 0.0001), and between groups 4 and 5 versus groups 1-3 (p <
0.0001), and group 4 versus group 5 (p = 0.02) only. CONCLUSIONS: The results
suggest that the presence of hypertension with or without LVH (and normal left
ventricular systolic function) does not affect NT proBNP concentrations.
Moreover, there is a significant rise in NT proBNP only when LVSD develops in
hypertension. Thus, NT proBNP remains a useful diagnostic aid for LVSD, even in
hypertensive patients.
PMID- 10677406
TI - Prolonged left ventricular dysfunction occurs in patients with coronary artery
disease after both dobutamine and exercise induced myocardial ischaemia.
AB - OBJECTIVE: To determine whether pharmacological stress leads to prolonged but
reversible left ventricular dysfunction in patients with coronary artery disease,
similar to that seen after exercise. DESIGN: A randomised crossover study of
recovery time of systolic and diastolic left ventricular function after exercise
and dobutamine induced ischaemia. SUBJECTS: 10 patients with stable angina,
angiographically proven coronary artery disease, and normal left ventricular
function. INTERVENTIONS: Treadmill exercise and dobutamine stress were performed
on different days. Quantitative assessment of systolic and diastolic left
ventricular function was performed using transthoracic echocardiography at
baseline and at regular intervals after each test. RESULTS: Both forms of stress
led to prolonged but reversible systolic and diastolic dysfunction. There was no
difference in the maximum double product (p = 0.53) or ST depression (p = 0.63)
with either form of stress. After exercise, ejection fraction was reduced at 15
and 30 minutes compared with baseline (mean (SEM), -5.6 (1.5)%, p < 0.05; and
6.1 (2.2)%, p < 0. 01), and at 30 and 45 minutes after dobutamine (-10.8 (1.8)%
and -5. 5 (1.8)%, both p < 0.01). Regional analysis showed a reduction in the
worst affected segment 15 and 30 minutes after exercise (-27.9 (7.2)% and -28.6
(5.7)%, both p < 0.01), and at 30 minutes after dobutamine (-32 (5.3)%, p <
0.01). The isovolumic relaxation period was prolonged 45 minutes after each form
of stress (p < 0.05). CONCLUSIONS: In patients with coronary artery disease,
dobutamine induced ischaemia results in prolonged reversible left ventricular
dysfunction, presumed to be myocardial stunning, similar to that seen after
exercise. Dobutamine induced ischaemia could therefore be used to study the
pathophysiology of this phenomenon further in patients with coronary artery
disease.
PMID- 10677407
TI - Images in cardiology. Abnormal ventricular conduction following dothiepin
overdose simulating acute myocardial infarction.
PMID- 10677408
TI - Patients with uncomplicated coronary artery disease have reduced heart rate
variability mainly affecting vagal tone.
AB - AIM: To investigate whether uncomplicated chronic coronary artery disease causes
changes in heart rate variability and if so, whether the heart rate variability
pattern is different from that described in patients with acute myocardial
infarction. METHODS: Heart rate variability was studied in 65 patients with
angina who had no previous myocardial infarcts, no other diseases, and were on no
drug that could influence the sinus node. Results were compared with 33 age
matched healthy subjects. The diagnosis of coronary artery disease in angina
patients was established by coronary angiography in 58, by thallium scintigraphy
in six, and by exercise test only in one. Patients and controls were Holter
monitored 24 hours outside hospital, and heart rate variability was calculated in
the frequency domain as global power (GP: 0.01-1.00 Hz), low frequency peak (LF:
0. 04-0.15 Hz), high frequency peak (HF: 0.15-0.40 Hz), LF/HF in ms(2), and in
the time domain as SDNN (SD of normal RR intervals), SDANN (SD of all five minute
mean normal RR intervals), SD (mean of all five minute SDs of mean RR intervals),
rMSSD (root mean square of differences of successive normal RR intervals) (all in
ms), and pNN50 (proportion of adjacent normal RR intervals differing more than 50
ms from the preceding RR interval) as per cent. RESULTS: The mean age in patients
and controls was 60.4 (range 32-81) and 59.1 (32-77) years, respectively (NS),
the male/female ratio, 57/65 and 24/33 (NS), and the mean time of Holter
monitoring, 23.0 (18-24) and 22.8 (18-24) hours (NS). Mortality in angina
patients was 0% (0/65) at one year, 0% (0/56) at two years, and 3% (1/33) at
three years. Compared with healthy subjects angina patients showed a reduction in
GP (p = 0.007), HF (p = 0.02), LF (p = 0.02), SD (p = 0.02), rMSSD (p = 0.01),
and pNN50 (p = 0.01). No significant difference was found in RR, LF/HF, SDNN, or
SDANN. CONCLUSIONS: Uncomplicated coronary artery disease without previous acute
myocardial infarction was associated with reduced high and low frequency heart
rate variability, including vagal tone. SDANN and SDNN, expressing ultra low and
very low frequencies which are known to reflect prognosis after acute myocardial
infarction, were less affected. This is in agreement with the good prognosis in
uncomplicated angina in this study.
PMID- 10677409
TI - Effects of cardiac sympathetic innervation on regional wall motion abnormality in
patients with long QT syndrome.
AB - AIM: To assess the spatial relation between regional cardiac sympathetic
innervation and regional ventricular repolarisation indicated by ventricular wall
motion abnormality in patients with congenital long QT syndrome. DESIGN: Regional
percentage uptake and washout rate of (123)I metaiodobenzylguanidine (MIBG) were
measured to assess cardiac sympathetic innervation in septum, anterior wall,
lateral wall, and posterior wall. Left ventricular short axis images on
echocardiography were digitised to reconstruct digitised M mode echocardiograms,
from which left ventricular wall thickness curves were obtained. The wall
thickening time (ThT) was defined as the period in which the instantaneous wall
thickness exceeded 90% of the maximum wall thickness. The ThT was measured from
the ventricular wall thickness curve at the same segments where regional
percentage uptake and washout rate of (123)I MIBG were measured. PATIENTS: Seven
patients with long QT syndrome. RESULTS: The regional washout rate (mean (SD)) of
(123)I MIBG in patients with long QT syndrome was greater in the segments with
decreased percentage uptake of (123)I MIBG than in those without (17.4 (10.6)% v
9.7 (16.5)%, p < 0. 03). ThT in segments both with and without decreased
percentage uptake of (123)I MIBG was longer than in control subjects (p < 0.
0001). ThT was longer in the segments with decreased percentage uptake of (123)I
MIBG than in those without (199 (70) ms v 150 (66) ms, p = 0.0018). CONCLUSIONS:
Activation of regional cardiac sympathetic terminals is likely to participate in
additional regional prolongation of ventricular repolarisation in patients with
long QT syndrome.
PMID- 10677410
TI - Acute yellow oleander (Thevetia peruviana) poisoning: cardiac arrhythmias,
electrolyte disturbances, and serum cardiac glycoside concentrations on
presentation to hospital.
AB - OBJECTIVE: To describe the cardiac arrhythmias, electrolyte disturbances, and
serum cardiac glycoside levels seen in patients presenting to hospital with acute
yellow oleander (Thevetia peruviana) poisoning and to compare these with
published reports of digitalis poisoning. DESIGN: Case series. SETTING: Medical
wards of Anuradhapura District General Hospital, Sri Lanka, and coronary care
unit of the Institute of Cardiology, National Hospital of Sri Lanka, Colombo, the
national tertiary referral centre for cardiology. PATIENTS: 351 patients with a
history of oleander ingestion. MEASUREMENTS: ECG and blood sample analysis on
admission. RESULTS: Most symptomatic patients had conduction defects affecting
the sinus node, the atrioventricular (AV) node, or both. Patients showing cardiac
arrhythmias that required transfer for specialised management had significantly
higher mean serum cardiac glycoside and potassium but not magnesium
concentrations. Although there was considerable overlap between groups, those
with conduction defects affecting both sinus and AV nodes had significantly
higher mean serum cardiac glycoside levels. CONCLUSIONS: Most of these young
previously healthy patients had conduction defects affecting the sinus or AV
nodes. Relatively few had the atrial or ventricular tachyarrhythmias or
ventricular ectopic beats that are typical of digoxin poisoning. Serious yellow
oleander induced arrhythmias were associated with higher serum cardiac glycoside
concentrations and hyperkalaemia but not with disturbances of magnesium.
PMID- 10677411
TI - Long term consequences of regressed coronary aneurysms after Kawasaki disease:
vascular wall morphology and function.
AB - OBJECTIVES: To investigate the long term consequences of regressed aneurysms
after Kawasaki disease, using follow up coronary angiography; to assess the
vascular wall morphology at the site of the aneurysms by intravascular ultrasound
imaging; and to evaluate the function of the affected vessels using intracoronary
infusions of acetylcholine and isosorbide dinitrate. DESIGN: 33 patients were
studied, 27 with previous Kawasaki disease and six with congenital heart disease.
All Kawasaki disease patients were followed for more than 10 years from disease
onset. The 33 patients comprised four groups: group 1 included 13 Kawasaki
disease patients with a total of 23 sites of regressed large sized (>/= 4 mm)
coronary aneurysms; group 2 included 13 Kawasaki disease patients with 22 sites
of regressed small sized (< 4 mm) coronary aneurysms (four patients had sites of
both large and small sized aneurysms); group 3 included a further five Kawasaki
disease patients with 25 normal coronary angiography sites in the acute stage of
Kawasaki disease; and group 4 comprised the six patients with congenital heart
disease as controls, with a total of 27 normal coronary angiography sites. During
coronary angiography, 15 microg of acetylcholine and 0.5 mg isosorbide dinitrate
were infused into the coronary artery. The luminal diameter at the sites was
measured using a cine-videodensitometric analyser, to assess the distensibility
of the coronary artery wall. RESULTS: Coronary angiography in all 22 patients in
groups 1 and 2 and in all the patients in group 3 was normal, with no stenoses
and no irregularity of the arterial wall. However, the intravascular ultrasound
imaging in groups 1 and 2 showed various degrees of the intimal thickening. In
groups 1 and 2, there was significantly more vascular constriction with
acetylcholine, and poorer dilatation with isosorbide dinitrate than in groups 3
or 4 (each p < 0.05, respectively). There was no difference between group 3 and
group 4 in response to either acetylcholine or isosorbide dinitrate, CONCLUSIONS:
There is evidence of persisting abnormal vascular wall morphology and vascular
dysfunction at the site of regressed coronary aneurysms in patients with previous
Kawasaki disease. These patients should be counselled to avoid potential risk
factors for atherosclerosis, and long term follow up is needed into adult life.
PMID- 10677412
TI - Antiarrhythmic management and implantable defibrillator use in survivors of
prehospital cardiac arrest without myocardial infarction in West Yorkshire.
AB - OBJECTIVE: To explore the current use of secondary preventive treatment in
survivors of out of hospital cardiac arrest without myocardial infarction
(primary ventricular tachycardia/ventricular fibrillation (VT/VF)) in West
Yorkshire, and assess the implications of recent studies on the benefits of
implantable cardioverter-defibrillators (AICD) in this context. DESIGN:
Retrospective analysis of an ambulance service based database of outcome after
resuscitation of out of hospital cardiac arrest and the Leeds AICD implantation
database. MAIN OUTCOME MEASURES: Mortality, rate of referral for specialist
investigation, antiarrhythmic treatment. RESULTS: Twelve month mortality
following successful discharge after primary VF arrest was 15%. Of 53 patients
with primary VF/VT, 29 apparently did not see a cardiologist during the initial
admission. Amiodarone was the most widely used antiarrhythmic agent. Six patients
(15%) received an AICD. During the same period 22 patients from the same
catchment area received an AICD following an in-hospital cardiac arrest.
CONCLUSIONS: Mortality among survivors of non-infarct related prehospital cardiac
arrest remains significant, with few patients being referred for specialist
investigation. The implementation of recent guidelines on AICD use in cardiac
arrest survivors would have resulted in an approximate 60% increase in the total
numbers of defibrillators implanted in the West Yorkshire area.
PMID- 10677413
TI - Partial left ventriculectomy improves left ventricular end systolic elastance in
patients with idiopathic dilated cardiomyopathy.
AB - OBJECTIVE: To assess the effect of partial left ventriculectomy (PLV) on estimate
of left ventricular end systolic elastance (Ees), arterial elastance, and
ventriculoarterial coupling. PATIENTS: 11 patients with idiopathic dilated
cardiomyopathy before and two weeks after PLV, and 11 controls. INTERVENTIONS:
Single plane left ventricular angiography with simultaneous measurements of
femoral artery pressure was performed during right heart pacing before and after
load reduction. RESULTS: PLV increased mean (SD) Ees from 0.52 (0.27) to 1.47
(0.62) mm Hg/ml (p = 0.0004). The increase in Ees remained significant after
correction for the change in left ventricular mass (p = 0.004) and end diastolic
volume (p = 0.048). As PLV had no effect on arterial elastance,
ventriculoarterial coupling improved from 3.25 (2.17) to 1.01 (0.93) (p = 0.017),
thereby maximising left ventricular stroke work. CONCLUSION: It appears that PLV
improves both Ees and ventriculoarterial coupling, thus increasing left
ventricular work efficiency.
PMID- 10677414
TI - Coronary arterial origins in transposition of the great arteries: factors that
affect outcome. A morphological and clinical study.
AB - OBJECTIVE: Transfer of the coronary arteries is crucial during the arterial
switch operation for transposition, but little attention has been paid to the
position of their orifices relative to the valvar sinuses. The objective of this
study was to determine the factors which are important for effective transfer and
to determine potential surgical significance. DESIGN: Morphological and clinical
study. SETTING: Two national centres for neonatal cardiac surgery. PATIENTS: 277
patients with transposition of the great arteries. One group comprised 88
necropsy specimens (ages ranging from 17 weeks of fetal life to 17 years old),
and the other comprised 189 children undergoing surgery. The coronary artery
orifices were inspected relative to the depth of the aortic sinuses (vertical
origin), relative to the commissures between the valvar leaflets (radial origin),
and their angle of exit from the aortic wall (angle of origin). The data were
compared with the surgical results. RESULTS: In the necropsy specimens, the
vertical origin of the arteries was at, or above, the sinutubular junction in
20%, the radial origin was paracommissural in 3%, and the angle of origin was not
orthogonal in 7%. Those with high take off and paracommissural origin were all
intramural. In the clinical cases, those children with high take off,
paracommissural origin or tangential origin had an increased risk at surgery.
CONCLUSIONS: In 20% of hearts, high take off, paracommissural orifice, or
tangential origin of coronary arteries is found. This may be recognised
preoperatively by echocardiography and may cause technical difficulty in transfer
during the arterial switch procedure.
PMID- 10677415
TI - Percutaneous transluminal septal myocardial ablation for hypertrophic obstructive
cardiomyopathy: long term follow up of the first series of 25 patients.
AB - OBJECTIVE: To determine the long term outcome in patients treated with
percutaneous transluminal septal myocardial ablation (PTSMA) for hypertrophic
obstructive cardiomyopathy (HOCM). DESIGN AND SETTING: Observational, single
centre study. PATIENTS: 25 patients (13 women, 12 men, mean (SD) age 54.7 (15.0)
years) with drug treatment resistant New York Heart Association (NYHA) class 2.8
(0. 6) symptoms attributed to a high left ventricular outflow gradient (LVOTG)
and a coronary artery anatomy suitable for intervention. INTERVENTION: PTSMA by
injection of 4.1 (2.6) ml of alcohol (96%) into 1.4 (0.6) septal perforator
arteries to ablate the hypertrophied interventricular septum. OUTCOME MEASURES:
During in-hospital follow up, enzyme rise, the frequency of atrioventricular
conduction lesions requiring permanent DDD pacing, and in-hospital mortality were
assessed. Long term follow up (30 (4) months, range 24-36 months) included
symptoms, echocardiographic measurements of left atrial and left ventricular
dimensions and function, and LVOTG. RESULTS: Mean postinterventional creatine
kinase rise was 780 (436) U/l. During PTSMA 13 patents developed total heart
block, permanent pacing being necessary in five of them. One 86 year old patient
died from ventricular fibrillation associated with intensive treatment (beta
mimetic and theophylline) for coexistent severe obstructive airway disease. After
three months, three patients underwent re-PTSMA because of a dissatisfactory
primary result, leading to LVOTG elimination in all of them. During long term
follow up, LVOTG showed sustained reduction (3 (6) mm Hg at rest and 12 (19) mm
Hg with provocation) associated with stable symptomatic improvement (NYHA class
1.2 (1.0)) and without significant global left ventricular dilatation.
CONCLUSIONS: PTSMA is an effective non-surgical technique for reduction of
symptoms and LVOTG in HOCM. Prospective, long term observations of larger
populations are necessary in order to determine the definitive significance of
the procedure.
PMID- 10677416
TI - Outcome from balloon induced coronary artery dissection after intracoronary beta
radiation.
AB - OBJECTIVE: To evaluate the healing of balloon induced coronary artery dissection
in individuals who have received beta radiation treatment and to propose a new
intravascular ultrasound (IVUS) dissection score to facilitate the comparison of
dissection through time. DESIGN: Retrospective study. SETTING: Tertiary referral
centre. PATIENTS: 31 patients with stable angina pectoris, enrolled in the beta
energy restenosis trial (BERT-1.5), were included. After excluding those who
underwent stent implantation, the evaluable population was 22 patients.
INTERVENTIONS: Balloon angioplasty and intracoronary radiation followed by
quantitative coronary angiography (QCA) and IVUS. Repeat QCA and IVUS were
performed at six month follow up. MAIN OUTCOME MEASURES: QCA and IVUS evidence of
healing of dissection. Dissection classification for angiography was by the
National Heart Lung Blood Institute scale. IVUS proven dissection was defined as
partial or complete. The following IVUS defined characteristics of dissection
were described in the affected coronary segments: length, depth, arc
circumference, presence of flap, and dissection score. Dissection was defined as
healed when all features of dissection had resolved. The calculated dose of
radiation received by the dissected area in those with healed versus non-healed
dissection was also compared. RESULTS: Angiography (type A = 5, B = 7, C = 4) and
IVUS proven (partial = 12, complete = 4) dissections were seen in 16 patients
following intervention. At six month follow up, six and eight unhealed
dissections were seen by angiography (A = 2, B = 4) and IVUS (partial = 7,
complete = 1), respectively. The mean IVUS dissection score was 5.2 (range 3-8)
following the procedure, and 4.6 (range 3-7) at follow up. No correlation was
found between the dose prescribed in the treated area and the presence of
unhealed dissection. No change in anginal status was seen despite the presence of
unhealed dissection. CONCLUSION: beta radiation appears to alter the normal
healing process, resulting in unhealed dissection in certain individuals. In view
of the delayed and abnormal healing observed, long term follow up is indicated
given the possible late adverse effects of radiation. Although in this cohort no
increase in cardiac events following coronary dissections was seen, larger
populations are needed to confirm this phenomenon. Stenting of all coronary
dissections may be warranted in patients scheduled for brachytherapy after
balloon angioplasty.
PMID- 10677417
TI - Biocompatibility of phosphorylcholine coated stents in normal porcine coronary
arteries.
AB - OBJECTIVE: To improve the biocompatibility of stents using a phosphorylcholine
coated stent as a form of biomimicry. INTERVENTIONS: Implantation of
phosphorylcholine coated (n = 20) and non-coated (n = 21) stents was performed in
the coronary arteries of 25 pigs. The animals were killed after five days (n =
6), four weeks (n = 7), and 12 weeks (n = 8), and the vessels harvested for
histology, scanning electron microscopy, and morphometry. MAIN OUTCOME MEASURES:
Stent performance was assessed by studying early endothelialization, neointima
formation, and vessel wall reaction to the synthetic coating. RESULTS: Stent
thrombosis did not occur in either group. Morphometry showed no significant
differences between the two study groups at any time point. At five days both the
coated and non-coated stents were equally well endothelialised (91% v 92%,
respectively). At four and 12 weeks there was no difference in intimal thickness
between the coated and non-coated stents. Up to 12 weeks postimplant the
phosphorylcholine coating was still discernible in the stent strut voids, and did
not appear to elicit an adverse inflammatory response. CONCLUSION: In this animal
model the phosphorylcholine coating showed excellent blood and tissue
compatibility, unlike a number of other polymers tested in a similar setting.
Given that the coating was present up to 12 weeks postimplant with no adverse
tissue reaction, it may be a potential candidate polymer for local drug delivery.
PMID- 10677419
TI - Pacemaker lead related tricuspid stenosis: a report of two cases.
AB - Only four cases of tricuspid stenosis related to endocardial pacemaker leads have
been reported. Two further cases associated with perforation of a tricuspid valve
leaflet by a pacemaker lead are presented: a 46 year old woman and a 60 year old
man. It is possible that tricuspid valve disease related to endocardial pacemaker
and non-thoracotomy defibrillator leads is underrecognized. Diagnosis requires
clinical suspicion and the use of Doppler echocardiography. Recent evidence of
fibrosis affecting the tricuspid valve in hearts from patients who have had non
thoracotomy defibrillator implants suggests that this problem could be more
common in the future.
PMID- 10677418
TI - Increased serum neopterin: a marker of coronary artery disease activity in women.
AB - OBJECTIVE: To assess whether neopterin concentrations in women with unstable
angina differ from those in women with chronic stable angina. DESIGN: Prospective
cohort study. SETTING: University hospital in south west London. PATIENTS: 114
consecutive women with angina were studied: 82 had chronic stable angina (typical
exertional chest pain, positive exercise ECG testing, and/or abnormal myocardial
scintigraphy; symptoms stable for at least three months), and 32 had unstable
angina (Braunwald class III). All patients with chronic stable angina (100%) and
18 with unstable angina (56.3%) underwent digital coronary angiography; neopterin
concentrations were determined using a commercially available immunoassay. MAIN
OUTCOME MEASURES: Major clinical events during one year follow up were
readmission with Braunwald's class IIIb unstable angina, non-fatal myocardial
infarction, and cardiac death. RESULTS: Major events occurred in 12 women with
chronic stable angina (14.6%) and nine women with unstable angina (28.1%). Mean
(range) neopterin concentrations were significantly higher in women with unstable
angina than in those with chronic stable angina (7.6 (5.1-11.5) nmol/l v 5.9 (4.4
7.5) nmol/l; p = 0.003), even after adjustment for variables which were
significantly different on univariate analysis. In women with chronic stable
angina, baseline neopterin concentrations were higher in those with cardiac
events than in those without events (7.1 (5.9-9.1) nmol/l v 5.7 (3.9-7.3 nmol/l);
p = 0.010), even after adjustment for variables with significant differences
between both groups on univariate analysis. CONCLUSIONS: On average, women with
unstable angina had significantly higher neopterin concentrations than women with
chronic stable angina. Women with chronic stable angina with events during follow
up had higher neopterin concentrations than those without events. Neopterin
concentrations were similar in patients with unstable angina and women with
chronic stable angina who developed events. Neopterin concentrations may
therefore be a marker of risk in women with coronary artery disease.
PMID- 10677420
TI - Abnormal atrial and ventricular repolarisation resembling myocardial injury after
tricyclic antidepressant drug intoxication.
PMID- 10677421
TI - Myocardial perfusion imaging.
PMID- 10677422
TI - The pathophysiology of acute coronary syndromes.
PMID- 10677423
TI - Antenatal diagnosis of heart disease.
PMID- 10677424
TI - Patterns of protein synthesis and tolerance of anoxia in root tips of maize
seedlings acclimated to a low-oxygen environment, and identification of proteins
by mass spectrometry.
AB - Tolerance of anoxia in maize root tips is greatly improved when seedlings are
pretreated with 2 to 4 h of hypoxia. We describe the patterns of protein
synthesis during hypoxic acclimation and anoxia. We quantified the incorporation
of [(35)S]methionine into total protein and 262 individual proteins under
different oxygen tensions. Proteins synthesized most rapidly under normoxic
conditions continued to account for most of the proteins synthesized during
hypoxic acclimation, while the production of a very few proteins was selectively
enhanced. When acclimated root tips were placed under anoxia, protein synthesis
was depressed and no "new" proteins were detected. We present evidence that
protein synthesis during acclimation, but not during subsequent anoxia, is
crucial for acclimation. The complex and quantitative changes in protein
synthesis during acclimation necessitate identification of large numbers of
individual proteins. We show that mass spectrometry can be effectively used to
identify plant proteins arrayed by two-dimensional gel electrophoresis. Of the 48
protein spots analyzed, 46 were identified by matching to the protein database.
We describe the expression of proteins involved in a wide range of cellular
functions, including previously reported anaerobic proteins, and discuss their
possible roles in adaptation of plants to low-oxygen stress.
PMID- 10677425
TI - Amino acid transporters are localized to transfer cells of developing pea seeds.
AB - To determine the nature and cellular localization of amino acid transport in pea
seeds, two cDNA clones belonging to the AAP family of H(+)/amino acid co
transporters (PsAAP1 and PsAAP2) were isolated from a cotyledon cDNA library of
pea (Pisum sativum L.). Functional expression in the yeast amino acid uptake
mutants 22Delta6AAL and 22Delta8AA showed that PsAAP1 mediates transport of
neutral, acidic, and basic amino acids. RNA-blot analyses showed that PsAAP1 is
expressed in seeds and vegetative organs, including amino acid sinks and sources,
whereas PsAAP2 could not be detected. For developing seeds, transcripts of PsAAP1
were detected in coats and cotyledons, with seed coats giving a weak signal. In
cotyledons, expression was highest in epidermal-transfer-cell-enriched tissue.
RNA in situ hybridization analysis showed that PsAAP1 was predominantly present
in epidermal transfer cells forming the outer surface of cotyledons, which abuts
the seed coats. Overall, our observations suggest that this transporter, which is
localized in transfer cells of cotyledons, might play a role in the uptake of the
full spectrum of amino acids released from seed coats.
PMID- 10677426
TI - Cell division and subsequent radicle protrusion in tomato seeds are inhibited by
osmotic stress but DNA synthesis and formation of microtubular cytoskeleton are
not.
AB - We studied cell cycle events in embryos of tomato (Lycopersicon esculentum Mill.
cv Moneymaker) seeds during imbibition in water and during osmoconditioning
("priming") using both quantitative and cytological analysis of DNA synthesis and
beta-tubulin accumulation. Most embryonic nuclei of dry, untreated control seeds
were arrested in the G(1) phase of the cell cycle. This indicated the absence of
DNA synthesis (the S-phase), as confirmed by the absence of bromodeoxyuridine
incorporation. In addition, beta-tubulin was not detected on western blots and
microtubules were not present. During imbibition in water, DNA synthesis was
activated in the radicle tip and then spread toward the cotyledons, resulting in
an increase in the number of nuclei in G(2). Concomitantly, beta-tubulin
accumulated and was assembled into microtubular cytoskeleton networks. Both of
these cell cycle events preceded cell expansion and division and subsequent
growth of the radicle through the seed coat. The activation of DNA synthesis and
the formation of microtubular cytoskeleton networks were also observed throughout
the embryo when seeds were osmoconditioned. However, this pre-activation of the
cell cycle appeared to become arrested in the G(2) phase since no mitosis was
observed. The pre-activation of cell cycle events in osmoconditioned seeds
appeared to be correlated with enhanced germination performance during re
imbibition in water.
PMID- 10677427
TI - Iron deficiency decreases the Fe(III)-chelate reducing activity of leaf
protoplasts.
AB - The ferric-chelate reductase (FC-R) activity of mesophyll protoplasts isolated
from Fe-sufficient (control) and Fe-deficient sugar beet (Beta vulgaris L.)
leaves has been characterized. Measurements were made in an ionic environment
similar to that in the apoplastic space of the sugar beet mesophyll cells. The FC
R activity of Fe-sufficient and Fe-deficient protoplasts was dependent on light.
Fe deficiency decreased markedly the FC-R activity per protoplast surface unit.
The optimal pH for the activity of the FC-R in mesophyll protoplasts was in the
range 5.5 to 6.0, typical of the apoplastic space. Beyond pH 6.0, the activity of
the FC-R in mesophyll protoplasts decreased markedly in both Fe-sufficient and Fe
deficient protoplasts. These data suggest that both the intrinsic decrease in FC
R activity per protoplast surface and a possible shift in the pH of the
apoplastic space could lead to the accumulation of physiologically inactive Fe
pools in chlorotic leaves.
PMID- 10677428
TI - Differentiation of mucilage secretory cells of the Arabidopsis seed coat.
AB - In some plant species, including Arabidopsis, fertilization induces the epidermal
cells of the outer ovule integument to differentiate into a specialized seed coat
cell type with a unique morphology and containing large quantities of
polysaccharide mucilage (pectin). Such seed coat mucilage cells are necessary for
neither viability nor germination under normal laboratory conditions. Thus, the
Arabidopsis seed coat offers a unique system with which to use genetics to
identify genes controlling cell morphogenesis and complex polysaccharide
biosynthesis and secretion. As a first step in the application of this system, we
have used microscopy to investigate the structure and differentiation of
Arabidopsis seed coat mucilage cells, including cell morphogenesis and the
synthesis, secretion, and extrusion of mucilage. During seed coat development in
Arabidopsis, the epidermal cells of the outer ovule integument grow and
differentiate into cells that produce large quantities of mucilage between the
primary cell wall and plasma membrane. Concurrent with mucilage production, the
cytoplasm is shaped into a column in the center of the cell. Following mucilage
secretion the cytoplasmic column is surrounded by a secondary cell wall to form a
structure known as the columella. Thus, differentiation of the seed coat mucilage
cells involves a highly regulated series of events including growth,
morphogenesis, mucilage biosynthesis and secretion, and secondary cell wall
synthesis.
PMID- 10677429
TI - Hypersensitivity of an Arabidopsis sugar signaling mutant toward exogenous
proline application.
AB - In transgenic Arabidopsis a patatin class I promoter from potato is regulated by
sugars and proline (Pro), thus integrating signals derived from carbon and
nitrogen metabolism. In both cases a signaling cascade involving protein
phosphatases is involved in induction. Other endogenous genes are also regulated
by both Pro and carbohydrates. Chalcone synthase (CHS) gene expression is induced
by both, whereas the Pro biosynthetic Delta(1)-pyrroline-5-carboxylate synthetase
(P5CS) is induced by high Suc concentrations but repressed by Pro, and Pro
dehydrogenase (ProDH) is inversely regulated. The mutant rsr1-1, impaired in
sugar dependent induction of the patatin promoter, is hypersensitive to low
levels of external Pro and develops autofluorescence and necroses. Toxicity of
Pro can be ameliorated by salt stress and exogenously supplied metabolizable
carbohydrates. The rsr1-1 mutant shows a reduced response regarding sugar
induction of CHS and P5CS expression. ProDH expression is de-repressed in the
mutant but still down-regulated by sugar. Pro toxicity seems to be mediated by
the degradation intermediate Delta(1)-pyrroline-5-carboxylate. Induction of the
patatin promoter by carbohydrates and Pro, together with the Pro hypersensitivity
of the mutant rsr1-1, demonstrate a new link between carbon/nitrogen and stress
responses.
PMID- 10677430
TI - Expression and localization of nitrilase during symptom development of the
clubroot disease in Arabidopsis.
AB - The expression of nitrilase in Arabidopsis during the development of the clubroot
disease caused by the obligate biotroph Plasmodiophora brassicae was
investigated. A time course study showed that only during the exponential growth
phase of the clubs was nitrilase prominently enhanced in infected roots compared
with controls. NIT1 and NIT2 are the nitrilase isoforms predominantly expressed
in clubroot tissue, as shown by investigating promoter-beta-glucuronidase fusions
of each. Two peaks of beta-glucuronidase activity were visible: an earlier peak
(21 d post inoculation) consisting only of the expression of NIT1, and a second
peak at about 32 d post inoculation, which predominantly consisted of NIT2
expression. Using a polyclonal antibody against nitrilase, it was shown that the
protein was mainly found in infected cells containing sporulating plasmodia,
whereas in cells of healthy roots and in uninfected cells of inoculated roots
only a few immunosignals were detected. To determine which effect a missing
nitrilase isoform might have on symptom development, the P. brassicae infection
in a nitrilase mutant (nit1-3) of Arabidopsis was investigated. As a comparison,
transgenic plants overexpressing NIT2 under the control of the cauliflower mosaic
virus 35S promoter were studied. Root galls were smaller in nit1-3 plants
compared with the wild type. The phenotype of smaller clubs in the mutant was
correlated with a lower free indole-3-acetic acid content in the clubs compared
with the wild type. Overexpression of nitrilase did not result in larger clubs
compared with the wild type. The putative role of nitrilase and auxins during
symptom development is discussed.
PMID- 10677431
TI - Cloning and functional characterization of a constitutively expressed nitrate
transporter gene, OsNRT1, from rice.
AB - Elucidating how rice (Oryza sativa) takes up nitrate at the molecular level could
help improve the low recovery rate (<50%) of nitrogen fertilizer in rice paddies.
As a first step toward that goal, we have cloned a nitrate transporter gene from
rice called OsNRT1. OsNRT1 is a new member of a growing transporter family called
PTR, which consists not only of nitrate transporters from higher plants that are
homologs of the Arabidopsis CHL1 (AtNRT1) protein, but also peptide transporters
from a wide variety of genera including animals, plants, fungi, and bacteria.
However, despite the fact that OsNRT1 shares a higher degree of sequence identity
with the two peptide transporters from plants (approximately 50%) than with the
nitrate transporters (approximately 40%) of the PTR family, no peptide transport
activity was observed when OsNRT1 was expressed in either Xenopus oocytes or
yeast. Furthermore, contrasting the dual-affinity nitrate transport activity of
CHL1, OsNRT1 displayed only low-affinity nitrate transport activity in Xenopus
oocytes, with a K(m) value of approximately 9 mM. Northern-blot and in situ
hybridization analysis indicated that OsNRT1 is constitutively expressed in the
most external layer of the root, epidermis and root hair. These data strongly
indicate that OsNRT1 encodes a constitutive component of a low-affinity nitrate
uptake system for rice.
PMID- 10677432
TI - Toward a functional catalog of the plant genome. A survey of genes for lipid
biosynthesis.
AB - Public databases now include vast amounts of recently acquired DNA sequences that
are only partially annotated and, furthermore, are often annotated by automated
methods that are subject to errors. Maximum information value of these databases
can be derived only by further detailed analyses that frequently require careful
examination of records in the context of biological functions. In this study we
present an example of such an analysis focused on plant glycerolipid synthesis.
Public databases were searched for sequences corresponding to 65 plant
polypeptides involved in lipid metabolism. Comprehensive search results and
analysis of genes, cDNAs and expressed sequence tags (ESTs) are available online
(http://www.canr.msu.edu/lgc). Multiple alignments provided a method to estimate
the number of genes in gene families. Further analysis of sequences allowed us to
tentatively identify several previously undescribed genes in Arabidopsis. For
example, two genomic sequences were identified as candidates for the palmitate
specific monogalactosyldiacylglycerol desaturase (FAD5). A candidate genomic
sequence for 3-ketoacyl-acyl-carrier protein (ACP) synthase involved in
mitochondrial fatty acid biosynthesis was also identified. Biotin carboxyl
carrier protein (BCCP) in Arabidopsis is encoded by at least two genes, but the
most abundant BCCP transcript so far has not been characterized. The large number
(>165,000) of plant ESTs also provides an opportunity to perform "digital
northern" comparisons of gene expression levels across many genes. EST abundance
in general correlated with biochemical and flux characteristics of the enzymes in
Arabidopsis leaf tissue. In a few cases, statistically significant differences in
EST abundance levels were observed for enzymes that catalyze similar reactions in
fatty acid metabolism. For example, ESTs for the FatB acyl-ACP thioesterase occur
21 times compared with 7 times for FatA acyl-ACP thioesterase, although flux
through the FatA reaction is several times higher than through FatB. Such
comparisons may provide initial clues toward previously undescribed regulatory
phenomena. The abundance of ESTs for ACP compared with that of stearoyl-ACP
desaturase and FatB acyl-ACP thioesterase suggests that concentrations of some
enzymes of fatty acid synthesis may be higher than their acyl-ACP substrates.
PMID- 10677433
TI - Influence of the testa on seed dormancy, germination, and longevity in
Arabidopsis.
AB - The testa of higher plant seeds protects the embryo against adverse environmental
conditions. Its role is assumed mainly by controlling germination through
dormancy imposition and by limiting the detrimental activity of physical and
biological agents during seed storage. To analyze the function of the testa in
the model plant Arabidopsis, we compared mutants affected in testa pigmentation
and/or structure for dormancy, germination, and storability. The seeds of most
mutants exhibited reduced dormancy. Moreover, unlike wild-type testas, mutant
testas were permeable to tetrazolium salts. These altered dormancy and
tetrazolium uptake properties were related to defects in the pigmentation of the
endothelium and its neighboring crushed parenchymatic layers, as determined by
vanillin staining and microscopic observations. Structural aberrations such as
missing layers or a modified epidermal layer in specific mutants also affected
dormancy levels and permeability to tetrazolium. Both structural and pigmentation
mutants deteriorated faster than the wild types during natural aging at room
temperature, with structural mutants being the most strongly affected.
PMID- 10677434
TI - Gibberellin requirement for Arabidopsis seed germination is determined both by
testa characteristics and embryonic abscisic acid.
AB - The mechanisms imposing a gibberellin (GA) requirement to promote the germination
of dormant and non-dormant Arabidopsis seeds were analyzed using the GA-deficient
mutant ga1, several seed coat pigmentation and structure mutants, and the
abscisic acid (ABA)-deficient mutant aba1. Testa mutants, which exhibit reduced
seed dormancy, were not resistant to GA biosynthesis inhibitors such as
tetcyclacis and paclobutrazol, contrarily to what was found before for other non
dormant mutants in Arabidopsis. However, testa mutants were more sensitive to
exogenous GAs than the wild-types in the presence of the inhibitors or when
transferred to a GA-deficient background. The germination capacity of the ga1-1
mutant could be integrally restored, without the help of exogenous GAs, by
removing the envelopes or by transferring the mutation to a tt background (tt4
and ttg1). The double mutants still required light and chilling for dormancy
breaking, which may indicate that both agents can have an effect independently of
GA biosynthesis. The ABA biosynthesis inhibitor norflurazon was partially
efficient in releasing the dormancy of wild-type and mutant seeds. These results
suggest that GAs are required to overcome the germination constraints imposed
both by the seed coat and ABA-related embryo dormancy.
PMID- 10677435
TI - Purification and characterization of barley dipeptidyl peptidase IV.
AB - Barley (Hordeum vulgare L.) storage proteins, which have a high content of
proline (Pro) and glutamine, are cleaved by cysteine endoproteases to yield
peptides with a Pro next to the N-terminal and/or C-terminal amino acid residues.
A peptidase cleaving after Xaa-Pro- at the N terminus of peptides was purified
from green barley malt. It was identified as a serine-type dipeptidyl peptidase
(DPP), based on inhibitor studies, and the nature of the cleavage product. It is
a monomeric glycoprotein with an apparent molecular mass of 105 kD (85 kD after
deglycosylation), with a pI of 3.55 and a pH optimum at 7.2. Substrate
specificity was determined with a series of fluorogenic peptide substrates with
the general formula Xaa-Pro-AMC, where Xaa is an unspecified amino acid and AMC
is 7-amino-4-methylcoumarin. The best substrates were Xaa = lysine and arginine,
while the poorest were Xaa = aspartic acid, phenylalanine, and glutamic acid. The
K(m) values ranged from 0.071 to 8.9 microM, compared with values of 9 to 130
microM reported for mammalian DPP IVs. We discuss the possible role of DPP IV in
the degradation of small Pro-containing peptides transported from the endosperm
to the embryo of the germinating barley grain.
PMID- 10677436
TI - Major protein of resting rhizomes of Calystegia sepium (hedge bindweed) closely
resembles plant RNases but has no enzymatic activity.
AB - The most abundant protein of resting rhizomes of Calystegia sepium (L.) R.Br.
(hedge bindweed) has been isolated and its corresponding cDNA cloned. The native
protein consists of a single polypeptide of 212 amino acid residues and occurs as
a mixture of glycosylated and unglycosylated isoforms. Both forms are derived
from the same preproprotein containing a signal peptide and a C-terminal
propeptide. Analysis of the deduced amino acid sequence indicated that the C.
sepium protein shows high sequence identity and structural similarity with plant
RNases. However, no RNase activity could be detected in highly purified
preparations of the protein. This apparent lack of activity results most probably
from the replacement of a conserved His residue, which is essential for the
catalytic activity of plant RNases. Our findings not only demonstrate the
occurrence of a catalytically inactive variant of an S-like RNase, but also
provide further evidence that genes encoding storage proteins may have evolved
from genes encoding enzymes or other biologically active proteins.
PMID- 10677437
TI - Nucleoside diphosphate kinase required for coleoptile elongation in rice.
AB - Although several nucleoside diphosphate (NDP) kinase genes have been cloned in
plants, little is known about the functional significance of this enzyme during
plant growth and development. We introduced a chimeric gene encoding an antisense
RNA of NDP kinase under the control of the Arabidopsis heat shock protein HSP81-1
promoter into rice (Oryza sativa L.) plants using the Agrobacterium tumefaciens
transformation system. The expression of antisense RNA down-regulated the
accumulation of mRNA, resulting in reduced enzyme activity even under the
standard growth temperature (25 degrees C) in transgenic plants. Following heat
shock treatment (37 degrees C), NDP kinase activities in some transgenic rice
plants were more reduced than those grown under 25 degrees C. The comparison of
the coleoptile growth under submersion showed that cell elongation process was
inhibited in antisense NDP kinase transgenic plants, suggesting that an altered
guanine nucleotide level may be responsible for the processes.
PMID- 10677438
TI - Interaction of root gravitropism and phototropism in Arabidopsis wild-type and
starchless mutants.
AB - Root gravitropism in wild-type Arabidopsis and in two starchless mutants, pgm1-1
and adg1-1, was evaluated as a function of light position to determine the
relative strengths of negative phototropism and of gravitropism and how much
phototropism affects gravitropic measurements. Gravitropism was stronger than
phototropism in some but not all light positions in wild-type roots grown for an
extended period, indicating that the relationship between the two tropisms is
more complex than previously reported. Root phototropism significantly influenced
the time course of gravitropic curvature and the two measures of sensitivity.
Light from above during horizontal exposure overestimated all three parameters
for all three genotypes except the wild-type perception time. At the irradiance
used (80 micromol m(-2) s(-1)), the shortest periods of illumination found to
exaggerate gravitropism were 45 min of continuous illumination and 2-min doses of
intermittent illumination. By growing roots in circumlateral light or by
gravistimulating in the dark, corrected values were obtained for each gravitropic
parameter. Roots of both starchless mutants were determined to be about three
times less sensitive than prior estimates. This study demonstrates the importance
of accounting for phototropism in the design of root gravitropism experiments in
Arabidopsis.
PMID- 10677439
TI - Phenylarsine oxide inhibits the fusicoccin-induced activation of plasma membrane
H(+)-ATPase.
AB - To investigate the mechanism by which fusicoccin (FC) induces the activation of
the plasma membrane (PM) H(+)-ATPase, we used phenylarsine oxide (PAO), a known
inhibitor of protein tyrosine-phosphatases. PAO was supplied in vivo in the
absence or presence of FC to radish (Raphanus sativus L.) seedlings and cultured
Arabidopsis cells prior to PM extraction. Treatment with PAO alone caused a
slight decrease of PM H(+)-ATPase activity and, in radish, a decrease of PM
associated 14-3-3 proteins. When supplied prior to FC, PAO drastically inhibited
FC-induced activation of PM H(+)-ATPase, FC binding to the PM, and the FC-induced
increase of the amount of 14-3-3 associated with the PM. On the contrary, PAO was
completely ineffective on all of the above-mentioned parameters when supplied
after FC. The H(+)-ATPase isolated from PAO-treated Arabidopsis cells maintained
the ability to respond to FC if supplied with exogenous, nonphosphorylated 14-3-3
proteins. Altogether, these results are consistent with a model in which the
dephosphorylated state of tyrosine residues of a protein(s), such as 14-3-3
protein, is required to permit FC-induced association between the 14-3-3 protein
and the PM H(+)-ATPase.
PMID- 10677440
TI - The gene pat-2, which induces natural parthenocarpy, alters the gibberellin
content in unpollinated tomato ovaries.
AB - We investigated the role of gibberellins (GAs) in the effect of pat-2, a
recessive mutation that induces facultative parthenocarpic fruit development in
tomato (Lycopersicon esculentum Mill.) using near-isogenic lines with two
different genetic backgrounds. Unpollinated wild-type Madrigal (MA/wt) and
Cuarenteno (CU/wt) ovaries degenerated, but GA(3) application induced
parthenocarpic fruit growth. On the contrary, parthenocarpic growth of MA/pat-2
and CU/pat-2 fruits, which occurs in the absence of pollination and hormone
application, was not affected by GA(3). Pollinated MA/wt and parthenocarpic
MA/pat-2 ovary development was negated by paclobutrazol, and this inhibitory
effect was counteracted by GA(3). The main GAs of the early-13-hydroxylation
pathway (GA(1), GA(3), GA(8), GA(19), GA(20), GA(29), GA(44), GA(53), and,
tentatively, GA(81)) and two GAs of the non-13-hydroxylation pathway (GA(9) and
GA(34)) were identified in MA/wt ovaries by gas chromatography-selected ion
monitoring. GAs were quantified in unpollinated ovaries at flower bud, pre
anthesis, and anthesis. In unpollinated MA/pat-2 and CU/pat-2 ovaries, the GA(20)
content was much higher (up to 160 times higher) and the GA(19) content was lower
than in the corresponding non-parthenocarpic ovaries. The application of an
inhibitor of 2-oxoglutarate-dependent dioxygenases suggested that GA(20) is not
active per se. The pat-2 mutation may increase GA 20-oxidase activity in
unpollinated ovaries, leading to a higher synthesis of GA(20), the precursor of
an active GA.
PMID- 10677441
TI - Basipetal auxin transport is required for gravitropism in roots of Arabidopsis.
AB - Auxin transport has been reported to occur in two distinct polarities,
acropetally and basipetally, in two different root tissues. The goals of this
study were to determine whether both polarities of indole-3-acetic acid (IAA)
transport occur in roots of Arabidopsis and to determine which polarity controls
the gravity response. Global application of the auxin transport inhibitor
naphthylphthalamic acid (NPA) to roots blocked the gravity response, root waving,
and root elongation. Immediately after the application of NPA, the root gravity
response was completely blocked, as measured by an automated video digitizer.
Basipetal [(3)H]IAA transport in Arabidopsis roots was inhibited by NPA, whereas
the movement of [(14)C]benzoic acid was not affected. Inhibition of basipetal IAA
transport by local application of NPA blocked the gravity response. Inhibition of
acropetal IAA transport by application of NPA at the root-shoot junction only
partially reduced the gravity response at high NPA concentrations. Excised root
tips, which do not receive auxin from the shoot, exhibited a normal response to
gravity. The Arabidopsis mutant eir1, which has agravitropic roots, exhibited
reduced basipetal IAA transport but wild-type levels of acropetal IAA transport.
These results support the hypothesis that basipetally transported IAA controls
root gravitropism in Arabidopsis.
PMID- 10677442
TI - The role of chloroplast electron transport and metabolites in modulating Rubisco
activity in tobacco. Insights from transgenic plants with reduced amounts of
cytochrome b/f complex or glyceraldehyde 3-phosphate dehydrogenase.
AB - Leaf metabolites, adenylates, and Rubisco activation were studied in two
transgenic tobacco (Nicotiana tabacum L. cv W38) types. Plants with reduced
amounts of cytochrome b/f complex (anti-b/f) have impaired electron transport and
a low transthylakoid pH gradient that restrict ATP and NADPH synthesis. Plants
with reduced glyceraldehyde 3-phosphate dehydrogenase (anti-GAPDH) have a
decreased capacity to use ATP and NADPH in carbon assimilation. The activation of
the chloroplast NADP-malate dehydrogenase decreased in anti-b/f plants,
indicating a low NADPH/NADP(+) ratio. The whole-leaf ATP/ADP in anti-b/f plants
was similar to wild type, while it increased in anti-GAPDH plants. In both plant
types, the CO(2) assimilation rates decreased with decreasing ribulose 1, 5
bisphosphate concentrations. In anti-b/f plants, CO(2) assimilation was further
compromised by reduced carbamylation of Rubisco, whereas in anti-GAPDH plants the
carbamylation remained high even at subsaturating ribulose 1,5-bisphosphate
concentrations. We propose that the low carbamylation in anti-b/f plants is due
to reduced activity of Rubisco activase. The results suggest that light
modulation of activase is not directly mediated via the electron transport rate
or stromal ATP/ADP, but some other manifestation of the balance between electron
transport and the consumption of its products. Possibilities include the
transthylakoid pH gradient and the reduction state of the acceptor side of
photosystem I and/or the degree of reduction of the thioredoxin pathway.
PMID- 10677443
TI - Redox control of psbA gene expression in the cyanobacterium Synechocystis PCC
6803. Involvement of the cytochrome b(6)/f complex.
AB - We investigated the role of the redox state of the photosynthetic and respiratory
electron transport chains on the regulation of psbA expression in Synechocystis
PCC 6803. Different means to modify the redox state of the electron carriers were
used: (a) dark to oxidize the whole electron transport chain; (b) a shift from
dark to light to induce its reduction; (c) the chemical interruption of the
electron flow at different points to change the redox state of specific electron
carriers; and (d) the presence of glucose to maintain a high reducing power in
darkness. We show that changes in the redox state of the intersystem electron
transport chain induce modifications of psbA transcript production and psbA mRNA
stability. Reduction of the intersystem electron carriers activates psbA
transcription and destabilizes the mRNA, while their oxidation induces a decrease
in transcription and a stabilization of the transcript. Furthermore, our data
suggest that the redox state of one of the electron carriers between the
plastoquinone pool and photosystem I influences not only the expression of the
psbA gene, but also that of other two photosynthetic genes, psaE and cpcBA. As a
working hypothesis, we propose that the occupancy of the Q(0) site in the
cytochrome b(6)/f complex may be involved in this regulation.
PMID- 10677444
TI - Regulatory role of the N terminus of the vacuolar calcium-ATPase in cauliflower.
AB - The vacuolar calmodulin (CaM)-stimulated Ca(2+)-ATPase, BCA1p, in cauliflower
(Brassica oleracea) has an extended N terminus, which was suggested to contain a
CaM-binding domain (S. Malmstrom, P. Askerlund, M.G. Palmgren [1997] FEBS Lett
400: 324-328). The goal of the present study was to determine the role of the N
terminus in regulating BCA1p. Western analysis using three different antisera
showed that the N terminus of BCA1p is cleaved off by trypsin and that the N
terminus contains the CaM-binding domain. Furthermore, the expressed N terminus
binds CaM in a Ca(2+)-dependent manner. A synthetic peptide corresponding to the
CaM-binding domain of BCA1p (Ala-19 to Leu-43) strongly inhibited ATP-dependent
Ca(2+) pumping by BCA1p in cauliflower low-density membranes, indicating that the
CaM-binding region of BCA1p also has an autoinhibitory function. The expressed N
terminus of BCA1p and a synthetic peptide (Ala-19 to Met-39) were good substrates
for phosphorylation by protein kinase C. Sequencing of the phosphorylated fusion
protein and peptide suggested serine-16 and/or serine-28 as likely targets for
phosphorylation. Phosphorylation of serine-28 had no effect on CaM binding to the
alanine-19 to methionine-39 peptide. Our results demonstrate the regulatory
importance of the N terminus of BCA1p as a target for CaM binding, trypsin
cleavage, and phosphorylation, as well as its importance as an autoinhibitory
domain.
PMID- 10677445
TI - Auxin-regulated genes encoding cell wall-modifying proteins are expressed during
early tomato fruit growth.
AB - An expansin gene, LeExp2, was isolated from auxin-treated, etiolated tomato
(Lycopersicon esculentum cv T5) hypocotyls. LeExp2 mRNA expression was restricted
to the growing regions of the tomato hypocotyl and was up-regulated during
incubation of hypocotyl segments with auxin. The pattern of expression of LeExp2
was also studied during tomato fruit growth, a developmental process involving
rapid cell enlargement. The expression of genes encoding a xyloglucan
endotransglycosylase (LeEXT1) and an endo-1, 4-beta-glucanase (Cel7), which, like
LeExp2, are auxin-regulated in etiolated hypocotyls (C. Catala, J.K.C. Rose, A.B.
Bennett [1997] Plant J 12: 417-426), was also studied to examine the potential
for synergistic action with expansins. LeExp2 and LeEXT1 genes were coordinately
regulated, with their mRNA accumulation peaking during the stages of highest
growth, while Cel7 mRNA abundance increased and remained constant during later
stages of fruit growth. The expression of LeExp2, LeEXT1, and Cel7 was
undetectable or negligible at the onset of and during fruit ripening, which is
consistent with a specific role of these genes in regulating cell wall loosening
during fruit growth, not in ripening-associated cell wall disassembly.
PMID- 10677446
TI - Intron-mediated enhancement of gene expression independent of unique intron
sequences and splicing.
AB - Either of the first two introns of the Arabidopsis tryptophan pathway gene PAT1
elevates mRNA accumulation from a PAT1:beta-glucuronidase (GUS) fusion roughly 5
fold without affecting the rate of PAT1:GUS transcription. To further explore the
mechanism of this intron-mediated enhancement of gene expression, we wanted to
determine whether splicing or specific intron sequences were necessary. In-frame
derivatives of PAT1 intron 1, whose splicing was prevented by a point mutation or
large deletions, were able to increase mRNA accumulation from a PAT1:GUS fusion,
demonstrating that splicing per se is not required. Furthermore, each of a series
of introns containing overlapping deletions that together span PAT1 intron 1
increased PAT1:GUS mRNA accumulation as much as the full-length intron did,
indicating that all intron sequences are individually dispensable for this
phenomenon. These results eliminate the simple idea that this intron stimulates
mRNA accumulation via a unique RNA-stabilizing sequence or through the completed
act of splicing. However, they are consistent with a possible role for redundant
intron sequence elements or an association of the pre-mRNA with the spliceosome.
PMID- 10677447
TI - Induction of an extracellular cyclic nucleotide phosphodiesterase as an accessory
ribonucleolytic activity during phosphate starvation of cultured tomato cells.
AB - During growth under conditions of phosphate limitation, suspension-cultured cells
of tomato (Lycopersicon esculentum Mill.) secrete phosphodiesterase activity in a
similar fashion to phosphate starvation-inducible ribonuclease (RNase LE), a
cyclizing endoribonuclease that generates 2':3'-cyclic nucleoside monophosphates
(NMP) as its major monomeric products (T. Nurnberger, S. Abel, W. Jost, K. Glund
[1990] Plant Physiol 92: 970-976). Tomato extracellular phosphodiesterase was
purified to homogeneity from the spent culture medium of phosphate-starved cells
and was characterized as a cyclic nucleotide phosphodiesterase. The purified
enzyme has a molecular mass of 70 kD, a pH optimum of 6.2, and an isoelectric
point of 8.1. The phosphodiesterase preparation is free of any detectable
deoxyribonuclease, ribonuclease, and nucleotidase activity. Tomato extracellular
phosphodiesterase is insensitive to EDTA and hydrolyzes with no apparent base
specificity 2':3'-cyclic NMP to 3'-NMP and the 3':5'-cyclic isomers to a mixture
of 3'-NMP and 5'-NMP. Specific activities of the enzyme are 2-fold higher for
2':3'-cyclic NMP than for 3':5'-cyclic isomers. Analysis of monomeric products of
sequential RNA hydrolysis with purified RNase LE, purified extracellular
phosphodiesterase, and cleared -Pi culture medium as a source of 3'-nucleotidase
activity indicates that cyclic nucleotide phosphodiesterase functions as an
accessory ribonucleolytic activity that effectively hydrolyzes primary products
of RNase LE to substrates for phosphate-starvation-inducible
phosphomonoesterases. Biosynthetical labeling of cyclic nucleotide
phopshodiesterase upon phosphate starvation suggests de novo synthesis and
secretion of a set of nucleolytic enzymes for scavenging phosphate from
extracellular RNA substrates.
PMID- 10677448
TI - Nitrogenase activity in Alnus incana root nodules. Responses to O(2) and short
term N(2) deprivation.
AB - O(2) and host-microsymbiont interactions are key factors affecting the physiology
of N(2)-fixing symbioses. To determine the relationship among nitrogenase
activity of Frankia-Alnus incana root nodules, O(2) concentration, and short-term
N(2) deprivation, intact nodulated roots were exposed to various O(2) pressures
(pO(2)) and Ar:O(2) in a continuous flow-through system. Nitrogenase activity
(H(2) production) occurred at a maximal rate at 20% O(2). Exposure to short-term
N(2) deprivation in Ar:O(2) carried out at either 17%, 21%, or 25% O(2) caused a
decline in the nitrogenase activity at 21% and 25% O(2) by 12% and 25%,
respectively. At 21% O(2), nitrogenase activity recovered to initial activity
within 60 min. The decline rate was correlated with the degree of inhibition of
N(2) fixation. Respiration (net CO(2) evolution) decreased in response to the
N(2) deprivation at all pO(2) values and did not recover during the time in
Ar:O(2). Increasing the pO(2) from 21% to 25% and decreasing the pO(2) from 21%
to 17% during the decline further decreased rather than stimulated nitrogenase
activity, showing that the decline was not due to O(2) limitation. The decline
was possibly due to a temporary disturbance in the supply of reductant to
nitrogenase with a partial O(2) inhibition of nitrogenase at 25% O(2). These
results are consistent with a fixed O(2) diffusion barrier in A. incana root
nodules, and show that A. incana nodules differ from legume nodules in the
response of the nitrogenase activity to O(2) and N(2) deprivation.
PMID- 10677449
TI - A specific beta-glucosidase-aggregating factor is responsible for the beta
glucosidase null phenotype in maize.
AB - Maize (Zea mays L.) beta-glucosidase was extracted from shoots of a wild-type
(K55) and a "null" (H95) maize genotype. Enzyme activity assays and
electrophoretic data showed that extracts from the null genotype had about 10% of
the activity present in the normal genotype. Zymograms of the null genotype were
devoid of any activity bands in the resolving gel, but had a smeared zone of
activity in the stacking gel after native polyacrylamide gel electrophoresis.
When extracts were made with buffers containing 0.5% to 2% sodium dodecyl
sulfate, the smeared activity zone entered the resolving gel as a distinct band.
These data indicated that the null genotypes have beta-glucosidase activity, but
the enzyme occurs as insoluble or poorly soluble large quaternary complexes
mediated by a beta-glucosidase-aggregating factor (BGAF). BGAF is a 35-kD protein
and binds specifically to beta-glucosidase and renders it insoluble during
extraction. BGAF also precipitates beta-glucosidase that is added exogenously to
supernatant fluids of the null tissue extracts. The specific beta-glucosidase
aggregating activity of BGAF is unequivocally demonstrated. These data clearly
show that the monogenic inheritance reported for the null alleles at the beta
glucosidase gene is actually for the BGAF protein, and BGAF is solely responsible
for beta-glucosidase aggregation and insolubility and, thus, the apparent null
phenotype.
PMID- 10677451
TI - Distinguishing between luminal and localized proton buffering pools in thylakoid
membranes.
AB - The dual gradient energy coupling hypothesis posits that chloroplast thylakoid
membranes are energized for ATP formation by either a delocalized or a localized
proton gradient geometry. Localized energy coupling is characterized by
sequestered domains with a buffering capacity of approximately 150 nmol H(+) mg(
1) chlorophyll (Chl). A total of 30 to 40 nmol mg(-1) Chl of the total
sequestered domain buffering capacity is contributed by lysines with anomolously
low pK(a)s, which can be covalently derivatized with acetic anhydride. We report
that in thylakoid membranes treated with acetic anhydride, luminal acidification
by a photosystem I (duraquinol [DQH(2)] to methyl viologen [MV]) proton pumping
partial reaction was nearly completely inhibited, as measured by three separate
assays, yet surprisingly, H(+) accumulation still occurred to the significant
level of more than 100 nmol H(+) mg Chl(-1), presumably into the sequestered
domains. The treatment did not increase the observed rate constant of dark H(+)
efflux, nor was electron transport significantly inhibited. These data provide
support for the existence of a sequestered proton translocating pathway linking
the redox reaction H(+) ion sources with the CF(0) H(+) channel. The sequestered,
low-pK(a) Lys groups appear to have a role in the H(+) diffusion process and
chemically modifying them blocks the putative H(+) relay system.
PMID- 10677450
TI - Nitric oxide modulates the activity of tobacco aconitase.
AB - Recent evidence suggests an important role for nitric oxide (NO) signaling in
plant-pathogen interactions. Additional elucidation of the role of NO in plants
will require identification of NO targets. Since aconitases are major NO targets
in animals, we examined the effect of NO on tobacco (Nicotiana tabacum)
aconitase. The tobacco aconitases, like their animal counterparts, were inhibited
by NO donors. The cytosolic aconitase in animals, in addition to being a key
redox and NO sensor, is converted by NO into an mRNA binding protein (IRP, or
iron-regulatory protein) that regulates iron homeostasis. A tobacco cytosolic
aconitase gene (NtACO1) whose deduced amino acid sequence shared 61% identity and
76% similarity with the human IRP-1 was cloned. Furthermore, residues involved in
mRNA binding by IRP-1 were conserved in NtACO1. These results reveal additional
similarities between the NO signaling mechanisms used by plants and animals.
PMID- 10677453
TI - Exposure to low irradiances favors the synthesis of 9-cis beta, beta-carotene in
Dunaliella salina (Teod.).
AB - We examined the effect of irradiance on the synthesis of beta-carotene and its
isomers by Dunaliella salina. Growth irradiance had a marked effect both on
growth of the alga (which was suppressed at both low and high irradiances) and on
the accumulation of beta-carotene. The accumulation of beta-carotene but not
alpha-carotene was closely linked to an increase in irradiance. Growth at low
irradiances (20-50 micromol m(-2) s(-1)) promoted a high ratio of 9-cis to all
trans beta-carotene (>2:1), while exposure to high irradiances (200-1,250
micromol m(-2) s(-1)) resulted in a large reduction in this ratio (to <0.45:1). A
similar pattern was seen for the geometric isomers of alpha-carotene, with
exposure to low irradiance favoring the accumulation of the 9-cis form. The
carotenoid biosynthesis inhibitors 4-chloro-5(methylamino)-2-(alpha-alpha-alpha
trifluoro-m-tolyl)-3-(sH )-pyridazinone and 2-(4-chlorophenylthio)triethylamine
caused the accumulation of the precursors phytoene and lycopene, respectively, in
D. salina. High-performance liquid chromatography and infrared analysis showed
that phytoene adopted the 15-cis and all-trans forms (as in higher plants), and
that lycopene primarily adopted the all-trans form. This indicates that
isomerization of beta-carotene takes place during or after cyclization.
PMID- 10677452
TI - Metabolic dysfunction and unabated respiration precede the loss of membrane
integrity during dehydration of germinating radicles.
AB - This study shows that dehydration induces imbalanced metabolism before loss of
membrane integrity in desiccation-sensitive germinated radicles. Using a
photoacoustic detection system, responses of CO(2) emission and fermentation to
drying were analyzed non-invasively in desiccation-tolerant and -intolerant
radicles of cucumber (Cucumis sativa) and pea (Pisum sativum). Survival after
drying and a membrane integrity assay showed that desiccation tolerance was
present during early imbibition and lost in germinated radicles. However,
tolerance could be re-induced in germinated cucumber radicles by incubation in
polyethylene glycol before drying. Tolerant and polyethylene glycol (PEG)-induced
tolerant radicles exhibited a much-reduced CO(2) production before dehydration
compared with desiccation-sensitive radicles. This difference was maintained
during dehydration. In desiccation-sensitive tissues, dehydration induced an
increase in the emission of acetaldehyde and ethanol that peaked well before the
loss of membrane integrity. Acetaldehyde emission from sensitive radicles was
significantly reduced when dehydration occurred in 50% O(2) instead of air.
Acetaldehyde/ethanol were not detected in dehydrating tolerant radicles of either
species or in polyethylene glycol-induced tolerant cucumber radicles. Thus, a
balance between down-regulation of metabolism during drying and O(2) availability
appears to be associated with desiccation tolerance. Using Fourier transform
infrared spectroscopy, acetaldehyde was found to disturb the phase behavior of
phospholipid vesicles, suggesting that the products resulting from imbalanced
metabolism in seeds may aggravate membrane damage induced by dehydration.
PMID- 10677454
TI - The electronic Plant Gene Register.
PMID- 10677455
TI - The past climate change heats up.
PMID- 10677456
TI - Of bears, conservation genetics, and the value of time travel.
PMID- 10677457
TI - Closing the ring: links between SMC proteins and chromosome partitioning,
condensation, and supercoiling.
PMID- 10677458
TI - More surprises in translation: initiation without the initiator tRNA.
PMID- 10677459
TI - Computation with biomolecules.
PMID- 10677460
TI - Ice-core evidence of abrupt climate changes.
AB - Ice-core records show that climate changes in the past have been large, rapid,
and synchronous over broad areas extending into low latitudes, with less
variability over historical times. These ice-core records come from high mountain
glaciers and the polar regions, including small ice caps and the large ice sheets
of Greenland and Antarctica.
PMID- 10677461
TI - Nonglacial rapid climate events: past and future.
AB - The paleoclimate record makes it clear that rapid climate shifts of the 20th
century are only a subset of possible climate system behavior that might occur in
the absence of glacial conditions, and that climatic surprises could be a
challenge for society even in the absence of significant greenhouse warming.
PMID- 10677462
TI - Was a change in thermohaline circulation responsible for the Little Ice Age?
PMID- 10677463
TI - Detecting holocene changes in thermohaline circulation.
AB - Throughout the last glacial cycle, reorganizations of deep ocean water masses
were coincident with rapid millennial-scale changes in climate. Climate changes
have been less severe during the present interglacial, but evidence for
concurrent deep ocean circulation change is ambiguous.
PMID- 10677464
TI - Abrupt climate change and thermohaline circulation: mechanisms and
predictability.
AB - The ocean's thermohaline circulation has long been recognized as potentially
unstable and has consequently been invoked as a potential cause of abrupt climate
change on all timescales of decades and longer. However, fundamental aspects of
thermohaline circulation changes remain poorly understood.
PMID- 10677465
TI - As climate changes, so do glaciers.
AB - Understanding abrupt climate changes requires detailed spatial/temporal records
of such changes, and to make these records, we need rapidly responding,
geographically widespread climate trackers. Glacial systems are such trackers,
and recent additions to the stratigraphic record show overall synchronous
response of glacial systems to climate change reflecting global atmosphere
conditions.
PMID- 10677466
TI - Climate change and the tropical Pacific: the sleeping dragon wakes.
PMID- 10677467
TI - Sensitivity and rapidity of vegetational response to abrupt climate change.
AB - Rapid climate change characterizes numerous terrestrial sediment records during
and since the last glaciation. Vegetational response is best expressed in
terrestrial records near ecotones, where sensitivity to climate change is
greatest, and response times are as short as decades.
PMID- 10677468
TI - Abrupt climate change in the computer: is it real?
AB - Models suggest that dramatic changes in the ocean circulation are responsible for
abrupt climate changes during the last ice age and may possibly alter the
relative climate stability of the last 10,000 years.
PMID- 10677469
TI - Very intense pulse in the groundwater flow in fissurized-porous stratum.
AB - An asymptotic solution is obtained corresponding to a very intense pulse: a
sudden strong increase and fast subsequent decrease of the water level at the
boundary of semi-infinite fissurized-porous stratum. This flow is of practical
interest: it gives a model of a groundwater flow after a high water period or
after a failure of a dam around a collector of liquid waste. It is demonstrated
that the fissures have a dramatic influence on the groundwater flow, increasing
the penetration depth and speed of fluid penetration into the stratum. A
characteristic property of the flow in fissurized-porous stratum is the rapid
breakthrough of the fluid at the first stage deeply into the stratum via a system
of cracks, feeding of porous blocks by the fluid in cracks, and at a later stage
feeding of advancing fluid flow in fissures by the fluid, accumulated in porous
blocks.
PMID- 10677470
TI - Archimedean solids: transition metal mediated rational self-assembly of
supramolecular-truncated tetrahedra.
AB - A family of nanoscale-sized supramolecular cage compounds with a polyhedral
framework is prepared by self-assembly from tritopic building blocks and
rectangular corner units via noncovalent coordination interactions. These highly
symmetrical cage compounds are described as face-directed, self-assembled
truncated tetrahedra with T(d) symmetry.
PMID- 10677471
TI - Molecular computation: RNA solutions to chess problems.
AB - We have expanded the field of "DNA computers" to RNA and present a general
approach for the solution of satisfiability problems. As an example, we consider
a variant of the "Knight problem," which asks generally what configurations of
knights can one place on an n x n chess board such that no knight is attacking
any other knight on the board. Using specific ribonuclease digestion to
manipulate strands of a 10-bit binary RNA library, we developed a molecular
algorithm and applied it to a 3 x 3 chessboard as a 9-bit instance of this
problem. Here, the nine spaces on the board correspond to nine "bits" or
placeholders in a combinatorial RNA library. We recovered a set of "winning"
molecules that describe solutions to this problem.
PMID- 10677472
TI - Two terrestrial records of rapid climatic change during the glacial-Holocene
transition (14,000- 9,000 calendar years B.P.) from Europe.
AB - Two independent multidisciplinary studies of climatic change during the glacial
Holocene transition (ca. 14,000-9,000 calendar yr B.P.) from Norway and
Switzerland have assessed organism responses to the rapid climatic changes and
made quantitative temperature reconstructions with modern calibration data sets
(transfer functions). Chronology at Krakenes, western Norway, was derived from
calibration of a high-resolution series of 14C dates. Chronologies at Gerzensee
and Leysin, Switzerland, were derived by comparison of delta18O in lake
carbonates with the delta18O record from the Greenland Ice Core Project. Both
studies demonstrate the sensitivity of terrestrial and aquatic organisms to rapid
temperature changes and their value for quantitative reconstruction of the
magnitudes and rates of the climatic changes. The rates in these two terrestrial
records are comparable to those in Greenland ice cores, but the actual
temperatures inferred apply to the terrestrial environments of the two regions.
PMID- 10677473
TI - Paleoproterozoic snowball earth: extreme climatic and geochemical global change
and its biological consequences.
AB - Geological, geophysical, and geochemical data support a theory that Earth
experienced several intervals of intense, global glaciation ("snowball Earth"
conditions) during Precambrian time. This snowball model predicts that
postglacial, greenhouse-induced warming would lead to the deposition of banded
iron formations and cap carbonates. Although global glaciation would have
drastically curtailed biological productivity, melting of the oceanic ice would
also have induced a cyanobacterial bloom, leading to an oxygen spike in the
euphotic zone and to the oxidative precipitation of iron and manganese. A
Paleoproterozoic snowball Earth at 2.4 Giga-annum before present (Ga) immediately
precedes the Kalahari Manganese Field in southern Africa, suggesting that this
rapid and massive change in global climate was responsible for its deposition. As
large quantities of O(2) are needed to precipitate this Mn, photosystem II and
oxygen radical protection mechanisms must have evolved before 2.4 Ga. This
geochemical event may have triggered a compensatory evolutionary branching in the
Fe/Mn superoxide dismutase enzyme, providing a Paleoproterozoic calibration point
for studies of molecular evolution.
PMID- 10677474
TI - Twentieth century climate change: evidence from small glaciers.
AB - The relation between changes in modern glaciers, not including the ice sheets of
Greenland and Antarctica, and their climatic environment is investigated to shed
light on paleoglacier evidence of past climate change and for projecting the
effects of future climate warming on cold regions of the world. Loss of glacier
volume has been more or less continuous since the 19th century, but it is not a
simple adjustment to the end of an "anomalous" Little Ice Age. We address the
1961-1997 period, which provides the most observational data on volume changes.
These data show trends that are highly variable with time as well as within and
between regions; trends in the Arctic are consistent with global averages but are
quantitatively smaller. The averaged annual volume loss is 147 mm.yr(-1) in water
equivalent, totaling 3.7 x 10(3) km(3) over 37 yr. The time series shows a shift
during the mid-1970s, followed by more rapid loss of ice volume and further
acceleration in the last decade; this is consistent with climatologic data.
Perhaps most significant is an increase in annual accumulation along with an
increase in melting; these produce a marked increase in the annual turnover or
amplitude. The rise in air temperature suggested by the temperature sensitivities
of glaciers in cold regions is somewhat greater than the global average
temperature rise derived largely from low altitude gauges, and the warming is
accelerating.
PMID- 10677475
TI - Can ozone depletion and global warming interact to produce rapid climate change?
AB - The atmosphere displays modes of variability whose structures exhibit a strong
longitudinally symmetric (annular) component that extends from the surface to the
stratosphere in middle and high latitudes of both hemispheres. In the past 30
years, these modes have exhibited trends that seem larger than their natural
background variability, and may be related to human influences on stratospheric
ozone and/or atmospheric greenhouse gas concentrations. The pattern of climate
trends during the past few decades is marked by rapid cooling and ozone depletion
in the polar lower stratosphere of both hemispheres, coupled with an increasing
strength of the wintertime westerly polar vortex and a poleward shift of the
westerly wind belt at the earth's surface. Annular modes of variability are
fundamentally a result of internal dynamical feedbacks within the climate system,
and as such can show a large response to rather modest external forcing. The
dynamics and thermodynamics of these modes are such that strong synergistic
interactions between stratospheric ozone depletion and greenhouse warming are
possible. These interactions may be responsible for the pronounced changes in
tropospheric and stratospheric climate observed during the past few decades. If
these trends continue, they could have important implications for the climate of
the 21st century.
PMID- 10677476
TI - Twist fields, the elliptic genus, and hidden symmetry.
AB - We combine infinite dimensional analysis (in particular a priori estimates and
twist positivity) with classical geometric structures, supersymmetry, and
noncommutative geometry. We establish the existence of a family of examples of
two-dimensional, twist quantum fields. We evaluate the elliptic genus in these
examples. We demonstrate a hidden SL(2,Z) symmetry of the elliptic genus, as
suggested by Witten.
PMID- 10677477
TI - The multivariate L1-median and associated data depth.
AB - This paper gives three related results: (i) a new, simple, fast, monotonically
converging algorithm for deriving the L1-median of a data cloud in Rd, a problem
that can be traced to Fermat and has fascinated applied mathematicians for over
three centuries; (ii) a new general definition for depth functions, as functions
of multivariate medians, so that different definitions of medians will,
correspondingly, give rise to different dept functions; and (iii) a simple closed
form formula of the L1-depth function for a given data cloud in Rd.
PMID- 10677478
TI - Evolutionary conservation of apoptosis mechanisms: lepidopteran and baculoviral
inhibitor of apoptosis proteins are inhibitors of mammalian caspase-9.
AB - We cloned a new inhibitor of apoptosis protein (IAP) homolog, SfIAP, from
Spodoptera frugiperda Sf-21 cells, a host of insect baculoviruses. SfIAP contains
two baculovirus IAP repeat domains followed by a RING domain. SfIAP has striking
amino acid sequence similarity with baculoviral IAPs, CpIAP and OpIAP, suggesting
that baculoviral IAPs may be host-derived genes. SfIAP and baculoviral CpIAP
inhibit Bax but not Fas-induced apoptosis in human cells. Their apoptosis
suppressing activity in mammalian cells requires both baculovirus IAP repeat and
RING domains. Further biochemical data suggest that SfIAP and CpIAP are specific
inhibitors of mammalian caspase-9, the pinnacle caspase in the
mitochondria/cytochrome c pathway for apoptosis, but are not inhibitors of
downstream caspase-3 and caspase-7. Thus the mechanisms by which insect and
baculoviral IAPs suppress apoptosis may involve inhibition of an insect caspase-9
homologue. Peptides representing the IAP-binding domain of the Drosophila cell
death protein Grim abrogated human caspase suppression by SfIAP and CpIAP,
implying evolutionary conservation of the functions of IAPs and their inhibitors.
PMID- 10677479
TI - Synergy in a medicinal plant: antimicrobial action of berberine potentiated by 5'
methoxyhydnocarpin, a multidrug pump inhibitor.
AB - Multidrug resistance pumps (MDRs) protect microbial cells from both synthetic and
natural antimicrobials. Amphipathic cations are preferred substrates of MDRs.
Berberine alkaloids, which are cationic antimicrobials produced by a variety of
plants, are readily extruded by MDRs. Several Berberis medicinal plants producing
berberine were found also to synthesize an inhibitor of the NorA MDR pump of a
human pathogen Staphylococcus aureus. The inhibitor was identified as 5'
methoxyhydnocarpin (5'-MHC), previously reported as a minor component of
chaulmoogra oil, a traditional therapy for leprosy. 5'-MHC is an amphipathic weak
acid and is distinctly different from the cationic substrates of NorA. 5'-MHC had
no antimicrobial activity alone but strongly potentiated the action of berberine
and other NorA substrates against S. aureus. MDR-dependent efflux of ethidium
bromide and berberine from S. aureus cells was completely inhibited by 5'-MHC.
The level of accumulation of berberine in the cells was increased strongly in the
presence of 5'-MHC, indicating that this plant compound effectively disabled the
bacterial resistance mechanism against the berberine antimicrobial.
PMID- 10677480
TI - Climate and infectious disease: use of remote sensing for detection of Vibrio
cholerae by indirect measurement.
AB - It has long been known that cholera outbreaks can be initiated when Vibrio
cholerae, the bacterium that causes cholera, is present in drinking water in
sufficient numbers to constitute an infective dose, if ingested by humans.
Outbreaks associated with drinking or bathing in unpurified river or brackish
water may directly or indirectly depend on such conditions as water temperature,
nutrient concentration, and plankton production that may be favorable for growth
and reproduction of the bacterium. Although these environmental parameters have
routinely been measured by using water samples collected aboard research ships,
the available data sets are sparse and infrequent. Furthermore, shipboard data
acquisition is both expensive and time-consuming. Interpolation to regional
scales can also be problematic. Although the bacterium, V. cholerae, cannot be
sensed directly, remotely sensed data can be used to infer its presence. In the
study reported here, satellite data were used to monitor the timing and spread of
cholera. Public domain remote sensing data for the Bay of Bengal were compared
directly with cholera case data collected in Bangladesh from 1992-1995. The
remote sensing data included sea surface temperature and sea surface height. It
was discovered that sea surface temperature shows an annual cycle similar to the
cholera case data. Sea surface height may be an indicator of incursion of
plankton-laden water inland, e.g., tidal rivers, because it was also found to be
correlated with cholera outbreaks. The extensive studies accomplished during the
past 25 years, confirming the hypothesis that V. cholerae is autochthonous to the
aquatic environment and is a commensal of zooplankton, i.e., copepods, when
combined with the findings of the satellite data analyses, provide strong
evidence that cholera epidemics are climate-linked.
PMID- 10677481
TI - The subcellular localization of acetyl-CoA carboxylase 2.
AB - Animals, including humans, express two isoforms of acetyl-CoA carboxylase (EC ),
ACC1 (M(r) = 265 kDa) and ACC2 (M(r) = 280 kDa). The predicted amino acid
sequence of ACC2 contains an additional 136 aa relative to ACC1, 114 of which
constitute the unique N-terminal sequence of ACC2. The hydropathic profiles of
the two ACC isoforms generally are comparable, except for the unique N-terminal
sequence in ACC2. The sequence of amino acid residues 1-20 of ACC2 is highly
hydrophobic, suggesting that it is a leader sequence that targets ACC2 for
insertion into membranes. The subcellular localization of ACC2 in mammalian cells
was determined by performing immunofluorescence microscopic analysis using
affinity-purified anti-ACC2-specific antibodies and transient expression of the
green fluorescent protein fused to the C terminus of the N-terminal sequences of
ACC1 and ACC2. These analyses demonstrated that ACC1 is a cytosolic protein and
that ACC2 was associated with the mitochondria, a finding that was confirmed
further by the immunocolocalization of a known human mitochondria-specific
protein and the carnitine palmitoyltransferase 1. Based on analyses of the fusion
proteins of ACC-green fluorescent protein, we concluded that the N-terminal
sequences of ACC2 are responsible for mitochondrial targeting of ACC2. The
association of ACC2 with the mitochondria is consistent with the hypothesis that
ACC2 is involved in the regulation of mitochondrial fatty acid oxidation through
the inhibition of carnitine palmitoyltransferase 1 by its product malonyl-CoA.
PMID- 10677482
TI - A structural basis for integrin activation by the cytoplasmic tail of the alpha
IIb-subunit.
AB - A key step in the activation of heterodimeric integrin adhesion receptors is the
transmission of an agonist-induced cellular signal from the short alpha- and/or
beta-cytoplasmic tails to the extracellular domains of the receptor. The
structural details of how the cytoplasmic tails mediate such an inside-out
signaling process remain unclear. We report herein the NMR structures of a
membrane-anchored cytoplasmic tail of the alpha(IIb)-subunit and of a mutant
alpha(IIb)-cytoplasmic tail that renders platelet integrin alpha(IIb)beta(3)
constitutively active. The structure of the wild-type alpha(IIb)-cytoplasmic tail
reveals a "closed" conformation where the highly conserved N-terminal membrane
proximal region forms an alpha-helix followed by a turn, and the acidic C
terminal loop interacts with the N-terminal helix. The structure of the active
mutant is significantly different, having an "open" conformation where the
interactions between the N-terminal helix and C-terminal region are abolished.
Consistent with these structural differences, the two peptides differ in
function: the wild-type peptide suppressed alpha(IIb)beta(3) activation, whereas
the mutant peptide did not. These results provide an atomic explanation for
extensive biochemical/mutational data and support a conformation-based "on/off
switch" model for integrin activation.
PMID- 10677483
TI - Human aspartic protease memapsin 2 cleaves the beta-secretase site of beta
amyloid precursor protein.
AB - The cDNAs of two new human membrane-associated aspartic proteases, memapsin 1 and
memapsin 2, have been cloned and sequenced. The deduced amino acid sequences show
that each contains the typical pre, pro, and aspartic protease regions, but each
also has a C-terminal extension of over 80 residues, which includes a single
transmembrane domain and a C-terminal cytosolic domain. Memapsin 2 mRNA is
abundant in human brain. The protease domain of memapsin 2 cDNA was expressed in
Escherichia coli and was purified. Recombinant memapsin 2 specifically hydrolyzed
peptides derived from the beta-secretase site of both the wild-type and Swedish
mutant beta-amyloid precursor protein (APP) with over 60-fold increase of
catalytic efficiency for the latter. Expression of APP and memapsin 2 in HeLa
cells showed that memapsin 2 cleaved the beta-secretase site of APP
intracellularly. These and other results suggest that memapsin 2 fits all of the
criteria of beta-secretase, which catalyzes the rate-limiting step of the in vivo
production of the beta-amyloid (Abeta) peptide leading to the progression of
Alzheimer's disease. Recombinant memapsin 2 also cleaved a peptide derived from
the processing site of presenilin 1, albeit with poor kinetic efficiency.
Alignment of cleavage site sequences of peptides indicates that the specificity
of memapsin 2 resides mainly at the S(1)' subsite, which prefers small side
chains such as Ala, Ser, and Asp.
PMID- 10677484
TI - Consequences of placing an intramolecular crosslink in myosin S1.
AB - This paper describes the placement of a crosslinking agent (dibromobimane)
between two thiols (Cys-522 and Cys-707) of a fragment, "S1," of the motor
protein, myosin. It turns out that fastening the first anchor of the crosslinker
is easy and rapid, but fastening the second anchor (Cys-522) is very temperature
dependent, taking 30 min at room temperature but about a week on ice. Moreover,
crystallography taken at 4 degrees C would seem to predict that the linkage is
impossible, because the span of the crosslinking agent is much less than the
interthiol distance. The simplest resolution of this seeming paradox is that
structural fluctuations of the protein render the linkage increasingly likely as
the temperature increases. Also, measurements of the affinity of MgADP for the
protein, as well as the magnetic resonance of the P-atoms of the ADP once
emplaced, suggest that binding the first reagent anchor to Cys-707 initiates an
influence that travels to the rather distant ADP-binding site, and it is
speculated what this "path of influence" might be.
PMID- 10677485
TI - Three-dimensional modeling of and ligand docking to vitamin D receptor ligand
binding domain.
AB - The ligand binding domain of the human vitamin D receptor (VDR) was modeled based
on the crystal structure of the retinoic acid receptor. The ligand binding pocket
of our VDR model is spacious at the helix 11 site and confined at the beta-turn
site. The ligand 1alpha, 25-dihydroxyvitamin D(3) was assumed to be anchored in
the ligand binding pocket with its side chain heading to helix 11 (site 2) and
the A-ring toward the beta-turn (site 1). Three residues forming hydrogen bonds
with the functionally important 1alpha- and 25-hydroxyl groups of 1alpha,25
dihydroxyvitamin D(3) were identified and confirmed by mutational analysis: the
1alpha-hydroxyl group is forming pincer-type hydrogen bonds with S237 and R274
and the 25-hydroxyl group is interacting with H397. Docking potential for various
ligands to the VDR model was examined, and the results are in good agreement with
our previous three-dimensional structure-function theory.
PMID- 10677486
TI - Self-assembly of large, ordered lamellae from non-bilayer lipids and integral
membrane proteins in vitro.
AB - In many biological membranes, the major lipids are "non-bilayer lipids," which in
purified form cannot be arranged in a lamellar structure. The structural and
functional roles of these lipids are poorly understood. This work demonstrates
that the in vitro association of the two main components of a membrane, the non
bilayer lipid monogalactosyldiacylglycerol (MGDG) and the chlorophyll-a/b light
harvesting antenna protein of photosystem II (LHCII) of pea thylakoids, leads to
the formation of large, ordered lamellar structures: (i) thin-section electron
microscopy and circular dichroism spectroscopy reveal that the addition of MGDG
induces the transformation of isolated, disordered macroaggregates of LHCII into
stacked lamellar aggregates with a long-range chiral order of the complexes; (ii)
small-angle x-ray scattering discloses that LHCII perturbs the structure of the
pure lipid and destroys the inverted hexagonal phase; and (iii) an analysis of
electron micrographs of negatively stained 2D crystals indicates that in MGDG
LHCII the complexes are found in an ordered macroarray. It is proposed that, by
limiting the space available for MGDG in the macroaggregate, LHCII inhibits
formation of the inverted hexagonal phase of lipids; in thylakoids, a spatial
limitation is likely to be imposed by the high concentration of membrane
associated proteins.
PMID- 10677487
TI - Folding and activity of circularly permuted forms of a polytopic membrane
protein.
AB - The transmembrane subunit of the Glc transporter (IICB(Glc)), which mediates
uptake and concomitant phosphorylation of glucose, spans the membrane eight
times. Variants of IICB(Glc) with the native N and C termini joined and new N and
C termini in the periplasmic and cytoplasmic surface loops were expressed in
Escherichia coli. In vivo transport/in vitro phosphotransferase activities of the
circularly permuted variants with the termini in the periplasmic loops 1 to 4
were 35/58, 32/37, 0/3, and 0/0% of wild type, respectively. The activities of
the variants with the termini in the cytoplasmic loops 1 to 3 were 0/25, 0/4 and
24/70, respectively. Fusion of alkaline phosphatase to the periplasmic C termini
stabilized membrane integration and increased uptake and/or phosphorylation
activities. These results suggest that internal signal anchor and stop transfer
sequences can function as N-terminal signal sequences in a circularly permuted
alpha-helical bundle protein and that the orientation of transmembrane segments
is determined by the amino acid sequence and not by the sequential appearance
during translation. Of the four IICB(Glc) variants with new termini in
periplasmic loops, only the one with the discontinuity in loop 4 is inactive. The
sequences of loop 4 and of the adjacent TM7 and TM8 are conserved in all
phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system transporters
of the glucose family.
PMID- 10677488
TI - A regulator of G protein signaling interaction surface linked to effector
specificity.
AB - Proteins of the regulator of G protein signaling (RGS) family accelerate GTP
hydrolysis by the alpha subunits (G(alpha)) of G proteins, leading to rapid
recovery of signaling cascades. Many different RGS proteins can accelerate GTP
hydrolysis by an individual G(alpha), and GTP hydrolysis rates of different
G(alpha)s can be enhanced by the same RGS protein. Consequently, the mechanisms
for specificity in RGS regulation and the residues involved remain unclear. Using
the evolutionary trace (ET) method, we have identified a cluster of residues in
the RGS domain that includes the RGS-G(alpha) binding interface and extends to
include additional functionally important residues on the surface. One of these
is within helix alpha3, two are in alpha5, and three are in the loop connecting
alpha5 and alpha6. A cluster of surface residues on G(alpha) previously
identified by ET, and composed predominantly of residues from the switch III
region and helix alpha3, is spatially contiguous with the ET-identified residues
in the RGS domain. This cluster includes residues proposed to interact with the
gamma subunit of G(talpha)'s effector, cGMP phosphodiesterase (PDEgamma). The
proximity of these clusters suggests that they form part of an interface between
the effector and the RGS-G(alpha) complex. Sequence variations in these residues
correlate with PDEgamma effects on GTPase acceleration. Because ET identifies
residues important for all members of a protein family, these residues likely
form a general site for regulation of G protein-coupled signaling cascades,
possibly by means of effector interactions.
PMID- 10677489
TI - Role of endocytosis in the activation of the extracellular signal-regulated
kinase cascade by sequestering and nonsequestering G protein-coupled receptors.
AB - Acting through a number of distinct pathways, many G protein-coupled receptors
(GPCRs) activate the extracellular signal-regulated kinase (ERK)/mitogen
activated protein kinase (MAPK) cascade. Recently, it has been shown that in some
cases, clathrin-mediated endocytosis is required for GPCR activation of the
ERK/MAPK cascade, whereas in others it is not. Accordingly, we compared ERK
activation mediated by a GPCR that does not undergo agonist-stimulated
endocytosis, the alpha(2A) adrenergic receptor (alpha(2A) AR), with ERK
activation mediated by the beta(2) adrenergic receptor (beta(2) AR), which is
endocytosed. Surprisingly, we found that in COS-7 cells, ERK activation by the
alpha(2A) AR, like that mediated by both the beta(2) AR and the epidermal growth
factor receptor (EGFR), is sensitive to mechanistically distinct inhibitors of
clathrin-mediated endocytosis, including monodansylcadaverine, a mutant dynamin
I, and a mutant beta-arrestin 1. Moreover, we determined that, as has been shown
for many other GPCRs, both alpha(2A) and beta(2) AR-mediated ERK activation
involves transactivation of the EGFR. Using confocal immunofluorescence
microscopy, we found that stimulation of the beta(2) AR, the alpha(2A) AR, or the
EGFR each results in internalization of a green fluorescent protein-tagged EGFR.
Although beta(2) AR stimulation leads to redistribution of both the beta(2) AR
and EGFR, activation of the alpha(2A) AR leads to redistribution of the EGFR but
the alpha(2A) AR remains on the plasma membrane. These findings separate GPCR
endocytosis from the requirement for clathrin-mediated endocytosis in EGFR
transactivation-mediated ERK activation and suggest that it is the receptor
tyrosine kinase or another downstream effector that must engage the endocytic
machinery.
PMID- 10677490
TI - Host factor Hfq of Escherichia coli stimulates elongation of poly(A) tails by
poly(A) polymerase I.
AB - Current evidence suggests that the length of poly(A) tails of bacterial mRNAs
result from a competition between poly(A) polymerase and exoribonucleases that
attack the 3' ends of RNAs. Here, we show that host factor Hfq is also involved
in poly(A) tail metabolism. Inactivation of the hfq gene reduces the length of
poly(A) tails synthesized at the 3' end of the rpsO mRNA by poly(A) polymerase I
in vivo. In vitro, Hfq stimulates synthesis of long tails by poly(A) polymerase
I. The strong binding of Hfq to oligoadenylated RNA probably explains why it
stimulates elongation of primers that already harbor tails of 20-35 A.
Polyadenylation becomes processive in the presence of Hfq. The similar properties
of Hfq and the PABPII poly(A) binding protein, which stimulates poly(A) tail
elongation in mammals, indicates that similar mechanisms control poly(A) tail
synthesis in prokaryotes and eukaryotes.
PMID- 10677491
TI - Allosteric inhibitors of inducible nitric oxide synthase dimerization discovered
via combinatorial chemistry.
AB - Potent and selective inhibitors of inducible nitric oxide synthase (iNOS) (EC )
were identified in an encoded combinatorial chemical library that blocked human
iNOS dimerization, and thereby NO production. In a cell-based iNOS assay (A-172
astrocytoma cells) the inhibitors had low-nanomolar IC(50) values and thus were
>1,000-fold more potent than the substrate-based direct iNOS inhibitors 1400W and
N-methyl-l-arginine. Biochemical studies confirmed that inhibitors caused
accumulation of iNOS monomers in mouse macrophage RAW 264.7 cells. High affinity
(K(d) approximately 3 nM) of inhibitors for isolated iNOS monomers was confirmed
by using a radioligand binding assay. Inhibitors were >1,000-fold selective for
iNOS versus endothelial NOS dimerization in a cell-based assay. The crystal
structure of inhibitor bound to the monomeric iNOS oxygenase domain revealed
inhibitor-heme coordination and substantial perturbation of the substrate binding
site and the dimerization interface, indicating that this small molecule acts by
allosterically disrupting protein-protein interactions at the dimer interface.
These results provide a mechanism-based approach to highly selective iNOS
inhibition. Inhibitors were active in vivo, with ED(50) values of <2 mg/kg in a
rat model of endotoxin-induced systemic iNOS induction. Thus, this class of
dimerization inhibitors has broad therapeutic potential in iNOS-mediated
pathologies.
PMID- 10677492
TI - Studies on the role of the hydrophobic domain of Ost4p in interactions with other
subunits of yeast oligosaccharyl transferase.
AB - In the yeast, Saccharomyces cerevisiae, oligosaccharyl transferase (OT), which
catalyzes the transfer of dolichol-linked oligosaccharide chains to nascent
polypeptides in the endoplasmic reticulum, consists of nine nonidentical membrane
protein subunits. Genetic and biochemical evidence indicated these nine proteins
exist in three subcomplexes. Three of the OT subunits (Ost4p, Ost3p, and Stt3p)
have been proposed to exist in one subcomplex. To investigate the interaction of
these three membrane proteins, initially we carried out a mutational analysis of
Ost4p, which is an extraordinarily small membrane protein containing only 36
amino acid residues. This analysis indicated that when single amino acid residues
in a region close to the luminal face of the putative transmembrane domain of
Ost4p were changed into an ionizable amino acid such as Lys or Asp, growth at 37
degrees C and OT activity measured in vitro were impaired. In addition, using
immunoprecipitation techniques and Western blot analysis, we found that with
these mutations the interaction between Ost4p, Ost3p, and Stt3p was disrupted.
Introduction of Lys or Asp residues at other positions in the putative
transmembrane domain or at the N or C terminus of Ost4p had no effect on
disrupting subunit interactions or impairing the activity of OT. These findings
suggest that a localized region of the putative transmembrane domain of Ost4p
mediates in stabilization of the interaction with the two other OT subunits
(Ost3p and Stt3p) in a subcomplex in the endoplasmic reticulum membrane.
PMID- 10677493
TI - Coupling between protein folding and allostery in the GroE chaperonin system.
AB - GroEL is an allosteric protein that facilitates protein folding in an ATP
dependent manner. Herein, the relationship between cooperative ATP binding by
GroEL and the kinetics of GroE-assisted folding of two substrates with different
GroES dependence, mouse dihydrofolate reductase (mDHFR) and mitochondrial malate
dehydrogenase, is examined by using cooperativity mutants of GroEL. Strong intra
ring positive cooperativity in ATP binding by GroEL decreases the rate of GroEL
assisted mDHFR folding owing to a slow rate of the ATP-induced transition from
the protein-acceptor state to the protein-release state. Inter-ring negative
cooperativity in ATP binding by GroEL is found to affect the kinetic partitioning
of mDHFR, but not of mitochondrial malate dehydrogenase, between folding in
solution and folding in the cavity underneath GroES. Our results show that
protein folding by this "two-stroke motor" is coupled to cooperative ATP binding.
PMID- 10677494
TI - Transition-state structure as a unifying basis in protein-folding mechanisms:
contact order, chain topology, stability, and the extended nucleus mechanism.
AB - I attempt to reconcile apparently conflicting factors and mechanisms that have
been proposed to determine the rate constant for two-state folding of small
proteins, on the basis of general features of the structures of transition
states. Phi-Value analysis implies a transition state for folding that resembles
an expanded and distorted native structure, which is built around an extended
nucleus. The nucleus is composed predominantly of elements of partly or well
formed native secondary structure that are stabilized by local and long-range
tertiary interactions. These long-range interactions give rise to connecting
loops, frequently containing the native loops that are poorly structured. I
derive an equation that relates differences in the contact order of a protein to
changes in the length of linking loops, which, in turn, is directly related to
the unfavorable free energy of the loops in the transition state. Kinetic data on
loop extension mutants of CI2 and alpha-spectrin SH3 domain fit the equation
qualitatively. The rate of folding depends primarily on the interactions that
directly stabilize the nucleus, especially those in native-like secondary
structure and those resulting from the entropy loss from the connecting loops,
which vary with contact order. This partitioning of energy accounts for the
success of some algorithms that predict folding rates, because they use these
principles either explicitly or implicitly. The extended nucleus model thus
unifies the observations of rate depending on both stability and topology.
PMID- 10677495
TI - A double-hexamer archaeal minichromosome maintenance protein is an ATP-dependent
DNA helicase.
AB - The minichromosome maintenance (MCM) proteins are essential for DNA replication
in eukaryotes. Thus far, all eukaryotes have been shown to contain six highly
related MCMs that apparently function together in DNA replication. Sequencing of
the entire genome of the thermophilic archaeon Methanobacterium
thermoautotrophicum has allowed us to identify only a single MCM-like gene (ORF
Mt1770). This gene is most similar to MCM4 in eukaryotic cells. Here we have
expressed and purified the M. thermoautotrophicum MCM protein. The purified
protein forms a complex that has a molecular mass of approximately 850 kDa,
consistent with formation of a double hexamer. The protein has an ATP-independent
DNA-binding activity, a DNA-stimulated ATPase activity that discriminates between
single- and double-stranded DNA, and a strand-displacement (helicase) activity
that can unwind up to 500 base pairs. The 3' to 5' helicase activity requires
both ATP hydrolysis and a functional nucleotide-binding site. Moreover, the
double hexamer form is the active helicase. It is therefore likely that an MCM
complex acts as the replicative DNA helicase in eukaryotes and archaea. The
simplified replication machinery in archaea may provide a simplified model for
assembly of the machinery required for initiation of eukaryotic DNA replication.
PMID- 10677496
TI - A 9-nt segment of a cellular mRNA can function as an internal ribosome entry site
(IRES) and when present in linked multiple copies greatly enhances IRES activity.
AB - This study addresses the properties of a newly identified internal ribosome entry
site (IRES) contained within the mRNA of the homeodomain protein Gtx. Sequential
deletions of the 5' untranslated region (UTR) from either end did not define
distinct IRES boundaries; when five nonoverlapping UTR fragments were tested,
four had IRES activity. These observations are consistent with other cellular
IRES analyses suggesting that some cellular IRESes are composed of segments (IRES
modules) that independently and combinatorially contribute to overall IRES
activity. We characterize a 9-nt IRES module from the Gtx 5' UTR that is 100%
complementary to the 18S rRNA at nucleotides 1132-1124. In previous work, we
demonstrated that this mRNA segment could be crosslinked to its complement within
intact 40S subunits. Here we show that increasing the number of copies of this
IRES module in the intercistronic region of a dicistronic mRNA strongly enhances
IRES activity in various cell lines. Ten linked copies increased IRES activity up
to 570-fold in Neuro 2a cells. This level of IRES activity is up to 63-fold
greater than that obtained by using the well characterized encephalomyocarditis
virus IRES when tested in the same assay system. When the number of nucleotides
between two of the 9-nt Gtx IRES modules was increased, the synergy between them
decreased. In light of these findings, we discuss possible mechanisms of ribosome
recruitment by cellular mRNAs, address the proposed role of higher order RNA
structures on cellular IRES activity, and suggest parallels between IRES modules
and transcriptional enhancer elements.
PMID- 10677497
TI - Determination of the binding sites of the proton transfer inhibitors Cd2+ and
Zn2+ in bacterial reaction centers.
AB - The reaction center (RC) from Rhodobacter sphaeroides couples light-driven
electron transfer to protonation of a bound quinone acceptor molecule, Q(B),
within the RC. The binding of Cd(2+) or Zn(2+) has been previously shown to
inhibit the rate of reduction and protonation of Q(B). We report here on the
metal binding site, determined by x-ray diffraction at 2.5-A resolution, obtained
from RC crystals that were soaked in the presence of the metal. The structures
were refined to R factors of 23% and 24% for the Cd(2+) and Zn(2+) complexes,
respectively. Both metals bind to the same location, coordinating to Asp-H124,
His-H126, and His-H128. The rate of electron transfer from Q(A)(-) to Q(B) was
measured in the Cd(2+)-soaked crystal and found to be the same as in solution in
the presence of Cd(2+). In addition to the changes in the kinetics, a structural
effect of Cd(2+) on Glu-H173 was observed. This residue was well resolved in the
x-ray structure-i.e., ordered-with Cd(2+) bound to the RC, in contrast to its
disordered state in the absence of Cd(2+), which suggests that the mobility of
Glu-H173 plays an important role in the rate of reduction of Q(B). The position
of the Cd(2+) and Zn(2+) localizes the proton entry into the RC near Asp-H124,
His-H126, and His-H128. Based on the location of the metal, likely pathways of
proton transfer from the aqueous surface to Q(B) are proposed.
PMID- 10677498
TI - Identification of the proton pathway in bacterial reaction centers: replacement
of Asp-M17 and Asp-L210 with asn reduces the proton transfer rate in the presence
of Cd2+.
AB - The reaction center (RC) from Rhodobacter sphaeroides converts light into
chemical energy through the reduction and protonation of a bound quinone molecule
Q(B) (the secondary quinone electron acceptor). We investigated the proton
transfer pathway by measuring the proton-coupled electron transfer, k(AB)((2))
[Q(A)Q(B) + H(+) --> Q(A)(Q(B)H)(-)] in native and mutant RCs in the absence and
presence of Cd(2+). Previous work has shown that the binding of Cd(2+) decreases
k(AB)((2)) in native RCs approximately 100-fold. The preceding paper shows that
bound Cd(2+) binds to Asp-H124, His-H126, and His-H128. This region represents
the entry point for protons. In this work we investigated the proton transfer
pathway connecting the entry point with Q(B) by searching for mutations that
greatly affect k(AB)((2)) ( greater, similar10-fold) in the presence of Cd(2+),
where k(AB)((2)) is limited by the proton transfer rate (k(H)). Upon mutation of
Asp-L210 or Asp-M17 to Asn, k(H) decreased from approximately 60 s(-1) to
approximately 7 s(-1), which shows the important role that Asp-L210 and Asp-M17
play in the proton transfer chain. By comparing the rate of proton transfer in
the mutants (k(H) approximately 7 s(-1)) with that in native RCs in the absence
of Cd(2+) (k(H) >/= 10(4) s(-1)), we conclude that alternate proton transfer
pathways, which have been postulated, are at least 10(3)-fold less effective.
PMID- 10677499
TI - The golgi-associated COPI-coated buds and vesicles contain beta/gamma -actin.
AB - It has been shown previously that the morphology and subcellular positioning of
the Golgi complex is controlled by actin microfilaments. To further characterize
the association between actin microfilaments and the Golgi complex, we have used
the Clostridium botulinum toxins C2 and C3, which specifically inhibit actin
polymerization and cause depolymerization of F-actin in intact cells by the ADP
ribosylation of G-actin monomers and the Rho small GTP-binding protein,
respectively. Normal rat kidney cells treated with C2 showed that disruption of
the actin and the collapse of the Golgi complex occurred concomitantly. However,
when cells were treated with C3, the actin disassembly was observed without any
change in the organization of the Golgi complex. The absence of the involvement
of Rho was further confirmed by the treatment with lysophosphatidic acid or
microinjection with the constitutively activated form of RhoA, both of which
induced the stress fiber formation without affecting the Golgi complex.
Immunogold electron microscopy in normal rat kidney cells revealed that beta- and
gamma-actin isoforms were found in Golgi-associated COPI-coated buds and
vesicles. Taken together, the results suggest that the Rho signaling pathway does
not directly regulate Golgi-associated actin microfilaments, and that beta- and
gamma-actins might be involved in the formation and/or transport of Golgi-derived
vesicular or tubular intermediates.
PMID- 10677500
TI - RANK is the intrinsic hematopoietic cell surface receptor that controls
osteoclastogenesis and regulation of bone mass and calcium metabolism.
AB - We have generated RANK (receptor activator of NF-kappaB) nullizygous mice to
determine the molecular genetic interactions between osteoprotegerin,
osteoprotegerin ligand, and RANK during bone resorption and remodeling processes.
RANK(-/-) mice lack osteoclasts and have a profound defect in bone resorption and
remodeling and in the development of the cartilaginous growth plates of
endochondral bone. The osteopetrosis observed in these mice can be reversed by
transplantation of bone marrow from rag1(-/-) (recombinase activating gene 1)
mice, indicating that RANK(-/-) mice have an intrinsic defect in osteoclast
function. Calciotropic hormones and proresorptive cytokines that are known to
induce bone resorption in mice and human were administered to RANK(-/-) mice
without inducing hypercalcemia, although tumor necrosis factor alpha treatment
leads to the rare appearance of osteoclast-like cells near the site of injection.
Osteoclastogenesis can be initiated in RANK(-/-) mice by transfer of the RANK
cDNA back into hematopoietic precursors, suggesting a means to critically
evaluate RANK structural features required for bone resorption. Together these
data indicate that RANK is the intrinsic cell surface determinant that mediates
osteoprotegerin ligand effects on bone resorption and remodeling as well as the
physiological and pathological effects of calciotropic hormones and proresorptive
cytokines.
PMID- 10677501
TI - A functional genetic screen identifies regions at the C-terminal tail and death
domain of death-associated protein kinase that are critical for its proapoptotic
activity.
AB - Death-associated protein kinase (DAP-kinase) is a Ca(+2)/calmodulin-regulated
serine/threonine kinase with a multidomain structure that participates in
apoptosis induced by a variety of signals. To identify regions in this protein
that are critical for its proapoptotic activity, we performed a genetic screen on
the basis of functional selection of short DAP-kinase-derived fragments that
could protect cells from apoptosis by acting in a dominant-negative manner. We
expressed a library of randomly fragmented DAP-kinase cDNA in HeLa cells and
treated these cells with IFN-gamma to induce apoptosis. Functional cDNA fragments
were recovered from cells that survived the selection, and those in the sense
orientation were examined further in a secondary screen for their ability to
protect cells from DAP-kinase-dependent tumor necrosis factor-alpha-induced
apoptosis. We isolated four biologically active peptides that mapped to the
ankyrin repeats, the "linker" region, the death domain, and the C-terminal tail
of DAP-kinase. Molecular modeling of the complete death domain provided a
structural basis for the function of the death-domain-derived fragment by
suggesting that the protective fragment constitutes a distinct substructure. The
last fragment, spanning the C-terminal serine-rich tail, defined a new regulatory
region. Ectopic expression of the tail peptide (17 amino acids) inhibited the
function of DAP-kinase, whereas removal of this region from the complete protein
caused enhancement of the killing activity, indicating that the C-terminal tail
normally plays a negative regulatory role. Altogether, this unbiased screen
highlighted functionally important regions in the protein and revealed an
additional level of regulation of DAP-kinase apoptotic function that does not
affect the catalytic activity.
PMID- 10677502
TI - Survival function of ERK1/2 as IL-3-activated, staurosporine-resistant Bcl2
kinases.
AB - Bcl2 phosphorylation at Ser-70 may be required for the full and potent
suppression of apoptosis in IL-3-dependent myeloid cells and can result from
agonist activation of mitochondrial protein kinase C (PKC). Paradoxically,
expression of exogenous Bcl2 can protect parental cells from apoptosis induced by
the potent PKC inhibitor, staurosporine (stauro). High concentrations of stauro
of up to 1 microM only partially inhibit IL-3-stimulated Bcl2 phosphorylation but
completely block PKC-mediated Bcl2 phosphorylation in vitro. These data indicate
a role for a stauro-resistant Bcl2 kinase (SRK). We show that aurintricarboxylic
acid (ATA), a nonpeptide activator of cellular MEK/mitogen-activated protein
kinase (MAPK) kinase, can induce Ser-70 phosphorylation of Bcl2 and support
survival of cells expressing wild-type but not the phosphorylation-incompetent
S70A mutant Bcl2. A role for a MEK/MAPK as a responsible SRK was implicated
because the highly specific MEK/MAPK inhibitor, PD98059, also can only partially
inhibit IL-3-induced Bcl2 phosphorylation, whereas the combination of PD98059 and
stauro completely blocks phosphorylation and synergistically enhances apoptosis.
p44MAPK/extracellular signal-regulated kinase 1 (ERK1) and p42 MAPK/ERK2 are
activated by IL-3, colocalize with mitochondrial Bcl2, and can directly
phosphorylate Bcl2 on Ser-70 in a stauro-resistant manner both in vitro and in
vivo. These findings suggest a role for the ERK1/2 kinases as SRKs. Thus, the
SRKs can serve to functionally link the IL-3-stimulated proliferative and
survival signaling pathways and, in a novel capacity, may explain how Bcl2 can
suppress stauro-induced apoptosis. In addition, although the mechanism of
regulation of Bcl2 by phosphorylation is not yet clear, our results indicate that
phosphorylation may functionally stabilize the Bcl2-Bax heterodimerization.
PMID- 10677503
TI - The catalytic subunit of DNA-dependent protein kinase selectively regulates p53
dependent apoptosis but not cell-cycle arrest.
AB - DNA damage induced by ionizing radiation (IR) activates p53, leading to the
regulation of downstream pathways that control cell-cycle progression and
apoptosis. However, the mechanisms for the IR-induced p53 activation and the
differential activation of pathways downstream of p53 are unclear. Here we
provide evidence that the catalytic subunit of DNA-dependent protein kinase (DNA
PKcs) serves as an upstream effector for p53 activation in response to IR,
linking DNA damage to apoptosis. DNA-PKcs knockout (DNA-PKcs-/-) mice were
exposed to whole-body IR, and the cell-cycle and apoptotic responses were
examined in their thymuses. Our data show that IR induction of apoptosis and Bax
expression, both mediated via p53, was significantly suppressed in the thymocytes
of DNA-PKcs-/- mice. In contrast, IR-induced cell-cycle arrest and p21 expression
were normal. Thus, DNA-PKcs deficiency selectively disrupts p53-dependent
apoptosis but not cell-cycle arrest. We also confirmed previous findings that p21
induction was attenuated and cell-cycle arrest was defective in the thymoctyes of
whole body-irradiated Atm-/- mice, but the apoptotic response was unperturbed.
Taken together, our results support a model in which the upstream effectors DNA
PKcs and Atm selectively activate p53 to differentially regulate cell-cycle and
apoptotic responses. Whereas Atm selects for cell-cycle arrest but not apoptosis,
DNA-PKcs selects for apoptosis but not cell-cycle arrest.
PMID- 10677504
TI - Aggregation of huntingtin in yeast varies with the length of the polyglutamine
expansion and the expression of chaperone proteins.
AB - Huntington's disease (HD) is an inherited neurodegenerative disorder caused by
polyglutamine (polyQ) expansions in the huntingtin (Ht) protein. A hallmark of HD
is the proteolytic production of an N-terminal fragment of Ht, containing the
polyQ repeat, that forms aggregates in the nucleus and cytoplasm of affected
neurons. Proteins with longer polyQ repeats aggregate more rapidly and cause
disease at an earlier age, but the mechanism of aggregation and its relationship
to disease remain unclear. To provide a new, genetically tractable model system
for the study of Ht, we engineered yeast cells to express an N-terminal fragment
of Ht with different polyQ repeat lengths of 25, 47, 72, or 103 residues, fused
to green fluorescent protein. The extent of aggregation varied with the length of
the polyQ repeat: at the two extremes, most HtQ103 protein coalesced into a
single large cytoplasmic aggregate, whereas HtQ25 exhibited no sign of
aggregation. Mutations that inhibit the ubiquitin/proteasome pathway at three
different steps had no effect on the aggregation of Ht fragments in yeast,
suggesting that the ubiquitination of Ht previously noted in mammalian cells may
not inherently be required for polyQ length-dependent aggregation. Changing the
expression levels of a wide variety of chaperone proteins in yeast neither
increased nor decreased Ht aggregation. However, Sis1, Hsp70, and Hsp104
overexpression modulated aggregation of HtQ72 and HtQ103 fragments. More
dramatically, the deletion of Hsp104 virtually eliminated it. These observations
establish yeast as a system for studying the causes and consequences of polyQ
dependent Ht aggregation.
PMID- 10677505
TI - Myeloblastin is a granulocyte colony-stimulating factor-responsive gene
conferring factor-independent growth to hematopoietic cells.
AB - Hematopoiesis depends on a pool of quiescent hematopoietic stem/progenitor cells.
When exposed to specific cytokines, a portion of these cells enters the cell
cycle to generate an amplified progeny. Myeloblastin (MBN) initially was
described as involved in proliferation of human leukemia cells. The granulocyte
colony-stimulating factor (G-CSF), which stimulates the proliferation of
granulocytic precursors, up-regulates MBN expression. Here we show that
constitutive overexpression of MBN confers factor-independent growth to murine
bone marrow-derived Ba/F3/G-CSFR cells. Our results point to MBN as a G-CSF
responsive gene critical to factor-independent growth and indicate that
expression of the G-CSF receptor is a prerequisite to this process. A 91-bp MBN
promoter region containing PU.1, C/EBP, and c-Myb binding sites is responsive to
G-CSF treatment. Although PU.1, C/EBP, and c-Myb transcription factors all were
critical for expression of MBN, its up-regulation by G-CSF was associated mainly
with PU.1. These findings suggest that MBN is an important target of PU.1 and a
key protease for factor-independent growth of hematopoietic cells.
PMID- 10677506
TI - neurogenin3 is required for the development of the four endocrine cell lineages
of the pancreas.
AB - In the mammalian pancreas, the endocrine cell types of the islets of Langerhans,
including the alpha-, beta-, delta-, and pancreatic polypeptide cells as well as
the exocrine cells, derive from foregut endodermal progenitors. Recent genetic
studies have identified a network of transcription factors, including Pdx1, Isl1,
Pax4, Pax6, NeuroD, Nkx2.2, and Hlxb9, regulating the development of islet cells
at different stages, but the molecular mechanisms controlling the specification
of pancreatic endocrine precursors remain unknown. neurogenin3 (ngn3) is a member
of a family of basic helix-loop-helix transcription factors that is involved in
the determination of neural precursor cells in the neuroectoderm. ngn3 is
expressed in discrete regions of the nervous system and in scattered cells in the
embryonic pancreas. We show herein that ngn3-positive cells coexpress neither
insulin nor glucagon, suggesting that ngn3 marks early precursors of pancreatic
endocrine cells. Mice lacking ngn3 function fail to generate any pancreatic
endocrine cells and die postnatally from diabetes. Expression of Isl1, Pax4,
Pax6, and NeuroD is lost, and endocrine precursors are lacking in the mutant
pancreatic epithelium. Thus, ngn3 is required for the specification of a common
precursor for the four pancreatic endocrine cell types.
PMID- 10677507
TI - Efficient studies of long-distance Bmp5 gene regulation using bacterial
artificial chromosomes.
AB - The regulatory regions surrounding many genes may be large and difficult to study
using standard transgenic approaches. Here we describe the use of bacterial
artificial chromosome clones to rapidly survey hundreds of kilobases of DNA for
potential regulatory sequences surrounding the mouse bone morphogenetic protein-5
(Bmp5) gene. Simple coinjection of large insert clones with lacZ reporter
constructs recapitulates all of the sites of expression observed previously with
numerous small constructs covering a large, complex regulatory region. The
coinjection approach has made it possible to rapidly survey other regions of the
Bmp5 gene for potential control elements, to confirm the location of several
elements predicted from previous expression studies using regulatory mutations at
the Bmp5 locus, to test whether Bmp5 control regions act similarly on endogenous
and foreign promoters, and to show that Bmp5 control elements are capable of
rescuing phenotypic effects of a Bmp5 deficiency. This rapid approach has
identified new Bmp5 control regions responsible for controlling the development
of specific anatomical structures in the vertebrate skeleton. A similar approach
may be useful for studying complex control regions surrounding many other genes
important in embryonic development and human disease.
PMID- 10677508
TI - Zic2 regulates the kinetics of neurulation.
AB - Mutation in human ZIC2, a zinc finger protein homologous to Drosophila odd
paired, causes holoprosencephaly (HPE), which is a common, severe malformation of
the brain in humans. However, the pathogenesis is largely unknown. Here we show
that reduced expression (knockdown) of mouse Zic2 causes neurulation delay,
resulting in HPE and spina bifida. Differentiation of the most dorsal neural
plate, which gives rise to both roof plate and neural crest cells, also was
delayed as indicated by the expression lag of a roof plate marker, Wnt3a. In
addition the development of neural crest derivatives such as dorsal root ganglion
was impaired. These results suggest that the Zic2 expression level is crucial for
the timing of neurulation. Because the Zic2 knockdown mouse is the first mutant
with HPE and spina bifida to survive to the perinatal period, the mouse will
promote analyses of not only the neurulation but also the pathogenesis of human
HPE.
PMID- 10677509
TI - Endogenous expression of Mullerian inhibiting substance in early postnatal rat
sertoli cells requires multiple steroidogenic factor-1 and GATA-4-binding sites.
AB - Mullerian inhibiting substance (MIS) is a key element required to complete
mammalian male sex differentiation. The expression pattern of MIS is tightly
regulated in fetal, neonatal, and prepubertal testes and adult ovaries and is
well conserved among mammalian species. Although several factors have been shown
to be essential to MIS expression, its regulatory mechanisms are not fully
understood. We have examined MIS promoter activity in 2-day postnatal primary
cultures of rat Sertoli cells that continue to express endogenous MIS mRNA. Using
this system, we found that the region between human MIS-269 and -192 is necessary
for full MIS promoter activity. We identified by DNase I footprint and
electrophoretic mobility-shift analyses a distal steroidogenic factor-1 (SF-1)
binding site that is essential for full promoter activity. Mutational analysis of
this new distal SF-1 site and the previously identified proximal SF-1 site showed
that both are necessary for transcriptional activation. Moreover, the proximal
promoter also contains multiple GATA-4-binding sites that are essential for
functional promoter activity. Thus multiple SF-1- and GATA-4-binding sites in the
MIS promoter are required for normal tissue-specific and developmental expression
of MIS.
PMID- 10677510
TI - Climate change is affecting altitudinal migrants and hibernating species.
AB - Calendar date of the beginning of the growing season at high altitude in the
Colorado Rocky Mountains is variable but has not changed significantly over the
past 25 years. This result differs from growing evidence from low altitudes that
climate change is resulting in a longer growing season, earlier migrations, and
earlier reproduction in a variety of taxa. At our study site, the beginning of
the growing season is controlled by melting of the previous winter's snowpack.
Despite a trend for warmer spring temperatures the average date of snowmelt has
not changed, perhaps because of the trend for increased winter precipitation.
This disjunction between phenology at low and high altitudes may create problems
for species, such as many birds, that migrate over altitudinal gradients. We
present data indicating that this already may be true for American robins, which
are arriving 14 days earlier than they did in 1981; the interval between arrival
date and the first date of bare ground has grown by 18 days. We also report
evidence for an effect of climate change on hibernation behavior; yellow-bellied
marmots are emerging 38 days earlier than 23 years ago, apparently in response to
warmer spring air temperatures. Migrants and hibernators may experience problems
as a consequence of these changes in phenology, which may be exacerbated if
climate models are correct in their predictions of increased winter snowfall in
our study area. The trends we report for earlier formation of permanent snowpack
and for a longer period of snow cover also have implications for hibernating
species.
PMID- 10677511
TI - Chemical defense against predation in an insect egg.
AB - The larva of the green lacewing (Ceraeochrysa cubana) (Neuroptera, Chrysopidae)
is a natural predator of eggs of Utetheisa ornatrix (Lepidoptera, Arctiidae), a
moth that sequesters pyrrolizidine alkaloids from its larval foodplant (Fabaceae,
Crotalaria spp.). Utetheisa eggs are ordinarily endowed with the alkaloid.
Alkaloid-free Utetheisa eggs, produced experimentally, are pierced by the larva
with its sharp tubular jaws and sucked out. Alkaloid-laden eggs, in contrast, are
rejected. When attacking an Utetheisa egg cluster (numbering on average 20 eggs),
the larva subjects it to an inspection process. It prods and/or pierces a small
number of eggs (on average two to three) and, if these contain alkaloid, it
passes "negative judgement" on the remainder of the cluster and turns away. Such
generalization on the part of the larva makes sense, because the eggs within
clusters differ little in alkaloid content. There is, however, considerable
between-cluster variation in egg alkaloid content, so clusters in nature can be
expected to range widely in palatability. To check each cluster for acceptability
must therefore be adaptive for the larva, just as it must be adaptive for
Utetheisa to lay its eggs in large clusters and to apportion alkaloid evenly
among eggs of a cluster.
PMID- 10677512
TI - Biodiversity of Costa Rican salamanders: implications of high levels of genetic
differentiation and phylogeographic structure for species formation.
AB - Although salamanders are characteristic amphibians in Holarctic temperate
habitats, in tropical regions they have diversified evolutionarily only in
tropical America. An adaptive radiation centered in Middle America occurred late
in the history of a single clade, the supergenus Bolitoglossa (Plethodontidae),
and large numbers of species now occur in diverse habitats. Sublineages within
this clade decrease in number from the northern to southern parts of Middle
America, and in Costa Rica, there are but three. Despite this phylogenetic
constraint, Costa Rica has many species; the number of salamander species on one
local elevational transect in the Cordillera de Talamanca may be the largest for
any such transect in the world. Extraordinary variation in sequences of the
mitochondrial gene cytochrome b within a clade of the genus Bolitoglossa in Costa
Rica reveals strong phylogeographic structure within a single species,
Bolitoglossa pesrubra. Allozymic variation in 19 proteins reveals a pattern
largely concordant with the mitochondrial DNA phylogeography. More species exist
than are currently recognized. Diversification occurs in restricted geographic
areas and involves sharp geographic and elevational differentiation and zonation.
In their degree of genetic differentiation at a local scale, these species of the
deep tropics exceed the known variation of extratropical salamanders, which also
differ in being less restricted in elevational range. Salamanders display
"tropicality" in that although speciose, they are usually local in distribution
and rare. They display strong ecological and physiological differentiation that
may contribute importantly to morphological divergence and species formation.
PMID- 10677513
TI - Population genetics of ice age brown bears.
AB - The Pleistocene was a dynamic period for Holarctic mammal species, complicated by
episodes of glaciation, local extinctions, and intercontinental migration. The
genetic consequences of these events are difficult to resolve from the study of
present-day populations. To provide a direct view of population genetics in the
late Pleistocene, we measured mitochondrial DNA sequence variation in seven
permafrost-preserved brown bear (Ursus arctos) specimens, dated from 14,000 to
42,000 years ago. Approximately 36,000 years ago, the Beringian brown bear
population had a higher genetic diversity than any extant North American
population, but by 15,000 years ago genetic diversity appears similar to the
modern day. The older, genetically diverse, Beringian population contained
sequences from three clades now restricted to local regions within North America,
indicating that current phylogeographic patterns may provide misleading data for
evolutionary studies and conservation management. The late Pleistocene
phylogeographic data also indicate possible colonization routes to areas south of
the Cordilleran ice sheet.
PMID- 10677514
TI - Hox cluster genomics in the horn shark, Heterodontus francisci.
AB - Reconstructing the evolutionary history of Hox cluster origins will lead to
insights into the developmental and evolutionary significance of Hox gene
clusters in vertebrate phylogeny and to their role in the origins of various
vertebrate body plans. We have isolated two Hox clusters from the horn shark,
Heterodontus francisci. These have been sequenced and compared with one another
and with other chordate Hox clusters. The results show that one of the horn shark
clusters (HoxM) is orthologous to the mammalian HoxA cluster and shows a
structural similarity to the amphioxus cluster, whereas the other shark cluster
(HoxN) is orthologous to the mammalian HoxD cluster based on cluster organization
and a comparison with noncoding and Hox gene-coding sequences. The persistence of
an identifiable HoxA cluster over an 800-million-year divergence time
demonstrates that the Hox gene clusters are highly integrated and structured
genetic entities. The data presented herein identify many noncoding sequence
motifs conserved over 800 million years that may function as genetic control
motifs essential to the developmental process.
PMID- 10677515
TI - Identification of hepatitis B virus indigenous to chimpanzees.
AB - Hepatitis B viruses (HBV) and related viruses, classified in the Hepadnaviridae
family, are found in a wide variety of mammals and birds. Although the chimpanzee
has been the primary experimental model of HBV infection, this species has not
been considered a natural host for the virus. Retrospective analysis of 13
predominantly wild-caught chimpanzees with chronic HBV infection identified a
unique chimpanzee HBV strain in 11 animals. Nucleotide and derived amino acid
analysis of the complete HBV genome and the gene coding for the hepatitis B
surface antigen (S gene) identified sequence patterns that could be used to
reliably identify chimpanzee HBV. This analysis indicated that chimpanzee HBV is
distinct from known human HBV genotypes and is closely related to HBVs previously
isolated from a chimpanzee, gibbons, gorillas, and orangutans.
PMID- 10677516
TI - In vitro cloning of complex mixtures of DNA on microbeads: physical separation of
differentially expressed cDNAs.
AB - We describe a method for cloning nucleic acid molecules onto the surfaces of 5
micrometer microbeads rather than in biological hosts. A unique tag sequence is
attached to each molecule, and the tagged library is amplified. Unique tagging of
the molecules is achieved by sampling a small fraction (1%) of a very large
repertoire of tag sequences. The resulting library is hybridized to microbeads
that each carry approximately 10(6) strands complementary to one of the tags.
About 10(5) copies of each molecule are collected on each microbead. Because such
clones are segregated on microbeads, they can be operated on simultaneously and
then assayed separately. To demonstrate the utility of this approach, we show how
to label and extract microbeads bearing clones differentially expressed between
two libraries by using a fluorescence-activated cell sorter (FACS). Because no
prior information about the cloned molecules is required, this process is
obviously useful where sequence databases are incomplete or nonexistent. More
importantly, the process also permits the isolation of clones that are expressed
only in given tissues or that are differentially expressed between normal and
diseased states. Such clones then may be spotted on much more cost-effective,
tissue- or disease-directed, low-density planar microarrays.
PMID- 10677517
TI - Mitochondrial carbonic anhydrase CA VB: differences in tissue distribution and
pattern of evolution from those of CA VA suggest distinct physiological roles.
AB - A cDNA for a second mouse mitochondrial carbonic anhydrase (CA) called CA VB was
identified by homology to the previously characterized murine CA V, now called CA
VA. The full-length cDNA encodes a 317-aa precursor that contains a 33-aa
classical mitochondrial leader sequence. Comparison of products expressed from
cDNAs for murine CA VB and CA VA in COS cells revealed that both expressed active
CAs that localized in mitochondria, and showed comparable activities in crude
extracts and in mitochondria isolated from transfected COS cells. Northern blot
analyses of total RNAs from mouse tissues and Western blot analyses of mouse
tissue homogenates showed differences in tissue-specific expression between CA VB
and CA VA. CA VB was readily detected in most tissues, while CA VA expression was
limited to liver, skeletal muscle, and kidney. The human orthologue of murine CA
VB was recently reported also. Comparison of the CA domain sequence of human CA
VB with that reported here shows that the CA domains of CA VB are much more
highly conserved between mouse and human (95% identity) than the CA domains of
mouse and human CA VAs (78% identity). Analysis of phylogenetic relationships
between these and other available human and mouse CA isozyme sequences revealed
that mammalian CA VB evolved much more slowly than CA VA, accepting amino acid
substitutions at least 4.5 times more slowly since each evolved from its
respective human-mouse ancestral gene around 90 million years ago. Both the
differences in tissue distribution and the much greater evolutionary constraints
on CA VB sequences suggest that CA VB and CA VA have evolved to assume different
physiological roles.
PMID- 10677518
TI - Nonlinearity in genetic decoding: homologous DNA replicase genes use alternatives
of transcriptional slippage or translational frameshifting.
AB - The tau and gamma subunits of DNA polymerase III are both encoded by a single
gene in Escherichia coli and Thermus thermophilus. gamma is two-thirds the size
of tau and shares virtually all its amino acid sequence with tau. E. coli and T.
thermophilus have evolved very different mechanisms for setting the approximate
1:1 ratio between tau and gamma. Both mechanisms put ribosomes into alternate
reading frames so that stop codons in the new frame serve to make the smaller
gamma protein. In E. coli, approximately 50% of initiating ribosomes translate
the dnaX mRNA conventionally to give tau, but the other 50% shift into the -1
reading frame at a specific site (A AAA AAG) in the mRNA to produce gamma. In T.
thermophilus ribosomal frameshifting is not required: the dnaX mRNA is a
heterogeneous population of molecules with different numbers of A residues
arising from transcriptional slippage on a run of nine T residues in the DNA
template. Translation of the subpopulation containing nine As (or +/- multiples
of three As) yields tau. The rest of the population of mRNAs (containing nine +/-
nonmultiples of three As) puts ribosomes into the alternate reading frames to
produce the gamma protein(s). It is surprising that two rather similar dnaX
sequences in E. coli and T. thermophilus lead to very different mechanisms of
expression.
PMID- 10677519
TI - Protective DNA vaccination against organ-specific autoimmunity is highly specific
and discriminates between single amino acid substitutions in the peptide
autoantigen.
AB - DNA vaccines that encode encephalitogenic sequences in tandem can protect from
subsequent experimental autoimmune encephalomyelitis induced with the
corresponding peptide. The mechanism for this protection and, in particular, if
it is specific for the amino acid sequence encoding the vaccine are not known. We
show here that a single amino acid exchange in position 79 from serine (nonself)
to threonine (self) in myelin basic protein peptide MBP68-85, which is a major
encephalitogenic determinant for Lewis rats, dramatically alters the protection.
Moreover, vaccines encoding the encephalitogenic sequence MBP68-85 do not protect
against the second encephalitogenic sequence MBP89-101 in Lewis rats and vice
versa. Thus, protective immunity conferred by DNA vaccination exquisitely
discriminates between peptide target autoantigens. No bystander suppression was
observed. The exact underlying mechanisms remain elusive because no simple
correlation between impact on ex vivo responses and protection against disease
were noted.
PMID- 10677520
TI - Human cytomegalovirus harbors its own unique IL-10 homolog (cmvIL-10).
AB - We identified a viral IL-10 homolog encoded by an ORF (UL111a) within the human
cytomegalovirus (CMV) genome, which we designated cmvIL-10. cmvIL-10 can bind to
the human IL-10 receptor and can compete with human IL-10 for binding sites,
despite the fact that these two proteins are only 27% identical. cmvIL-10
requires both subunits of the IL-10 receptor complex to induce signal
transduction events and biological activities. The structure of the cmvIL-10 gene
is unique by itself. The gene retained two of four introns of the IL-10 gene, but
the length of the introns was reduced. We demonstrated that cmvIL-10 is expressed
in CMV-infected cells. Thus, expression of cmvIL-10 extends the range of counter
measures developed by CMV to circumvent detection and destruction by the host
immune system.
PMID- 10677521
TI - Early expression of antiinsulin autoantibodies of humans and the NOD mouse:
evidence for early determination of subsequent diabetes.
AB - With the development of an insulin autoantibody (IAA) assay performed in 96-well
filtration plates, we have evaluated prospectively the development of IAA in NOD
mice (from 4 weeks of age) and children (from 7 to 10 months of age) at genetic
risk for the development of type 1 diabetes. NOD mice had heterogeneous
expression of IAA despite being inbred. IAA reached a peak between 8 and 16 weeks
and then declined. IAA expression by NOD mice at 8 weeks of age was strongly
associated with early development of diabetes, which occurred at 16-18 weeks of
age (NOD mice IAA(+) at 8 weeks: 83% (5/6) diabetic by 18 weeks versus 11% (1/9)
of IAA negative at 8 weeks; P <.01). In man, IAA was frequently present as early
as 9 months of age, the first sampling time. Of five children found to have
persistent IAA before 1 year of age, four have progressed to diabetes (all before
3.5 years of age) and the fifth is currently less than age 2. Of the 929 children
not expressing persistent IAA before age 1, only one has progressed to diabetes
to date (age onset 3), and this child expressed IAA at his second visit (age
1.1). In new onset patients, the highest levels of IAA correlated with an earlier
age of diabetes onset. Our data suggest that the program for developing diabetes
of NOD mice and humans is relatively "fixed" early in life and, for NOD mice, a
high risk of early development of diabetes is often determined by 8 weeks of age.
With such early determination of high risk of progression to diabetes,
immunologic therapies in humans may need to be tested in children before the
development of IAA for maximal efficacy.
PMID- 10677522
TI - The dual functions of fas ligand in the regulation of peripheral CD8+ and CD4+ T
cells.
AB - Although Fas ligand (FasL) is well characterized for its capacity to deliver a
death signal through its receptor Fas, recent work demonstrates that FasL also
can receive signals facilitating antigen (Ag)-specific proliferation of CD8(+) T
cells. The fact that the gld mutation differentially influences the proliferative
capacity of CD8(+) and CD4(+) T cells presented the intriguing possibility that a
single molecule may play opposing roles in these two subpopulations. The present
study focuses on how these positive and negative regulatory roles are balanced.
We show that naive CD4(+) T cells are responsive to FasL-mediated costimulation
on encounter with Ag when Fas-mediated death is prevented. Thus, the machinery
responsible for transducing the FasL positive reverse signal operates in both
CD4(+) and CD8(+) T cells. Instead, differential control of FasL expression
distinguishes the role of FasL in these two T cell subpopulations. FasL
costimulation occurs immediately on T cell receptor ligation and correlates with
the up-regulation of FasL expression on CD8(+) and naive CD4(+) T cells, both of
which are sensitive to the FasL costimulatory signal. Conversely, FasL-initiated
death occurs late in an immune response when high levels of FasL expression are
maintained on CD4(+) T cells that are sensitive to Fas-mediated death, but not on
CD8(+) T cells that are relatively insensitive to this signal. This careful
orchestration of FasL expression during times of susceptibility to costimulation
and conversely, to death, endows FasL with the capacity to both positively and
negatively regulate the peripheral T cell compartment.
PMID- 10677523
TI - Role of Syk in B-cell development and antigen-receptor signaling.
AB - Antigen receptors (BCRs) on developing B lymphocytes play two opposing roles
promoting survival of cells that may later bind a foreign antigen and inhibiting
survival of cells that bind too strongly to self-antigens. It is not known how
these opposing outcomes are signaled by BCRs on immature B cells. Here we analyze
the effect of a null mutation in the Syk tyrosine kinase on maturing B cells
displaying a transgene-encoded BCR that binds hen egg lysozyme (HEL). In the
absence of HEL antigen, HEL-specific BCRs are expressed normally on the surface
of Syk-deficient immature B-lineage cells, but this fails to promote maturation
beyond the earliest stages of B-lineage commitment. Binding of HEL antigen,
nevertheless, triggers phosphorylation of CD79alpha/beta BCR subunits and
modulation of receptors from the surface in Syk-deficient cells, but it cannot
induce an intracellular calcium response. Continuous binding of low- or high
avidity forms of HEL, expressed as self-antigens, fails to restore the signal
needed for maturation. Compared with the effects in the same system of null
mutations in other BCR signaling elements, such as CD45 and Lyn kinase, these
results indicate that Syk is essential for transmitting a signal that initiates
the program of B-lymphocyte maturation.
PMID- 10677524
TI - Hypothyroidism in transgenic mice expressing IFN-gamma in the thyroid.
AB - IFN-gamma has been implicated with contradictory results in the pathogenetic
process of autoimmune (Hashimoto's) thyroiditis, the most common cause of
hypothyroidism in adults. To test whether the local production of IFN-gamma can
lead to thyroid dysfunction, we have generated transgenic mice that express
constitutively IFN-gamma in the thyroid follicular cells. This expression
resulted in severe hypothyroidism, with growth retardation and disruption of the
thyroid architecture. The hypothyroidism derived from a profound inhibition of
the expression of the sodium iodide symporter gene. Taken together, these results
indicate a direct role of IFN-gamma in the thyroid dysfunction that occurs in
autoimmune thyroiditis.
PMID- 10677525
TI - Adapter proteins SLP-76 and BLNK both are expressed by murine macrophages and are
linked to signaling via Fcgamma receptors I and II/III.
AB - The SLP-76 (Src homology 2 domain-containing leukocyte protein of 76 kDa) adapter
protein is expressed in T cells and myeloid cells, whereas its homologue BLNK (B
cell linker protein) is expressed in B cells. SLP-76 and BLNK link immunoreceptor
tyrosine-based activation motif-containing receptors to signaling molecules that
include phospholipase C-gamma, mitogen-activated protein kinases, and the GTPases
Ras and Rho. SLP-76 plays a critical role in T cell receptor, FcvarepsilonRI and
gpVI collagen receptor signaling, and participates in signaling via FcgammaR and
killer cell inhibitory receptors. BLNK plays a critical role in B cell receptor
signaling. We show that murine bone marrow-derived macrophages express both SLP
76 and BLNK. Selective ligation of FcgammaRI and FcgammaRII/III resulted in
tyrosine phosphorylation of both SLP-76 and BLNK. SLP-76(-/-) bone marrow-derived
macrophages display FcgammaR-mediated tyrosine phosphorylation of Syk,
phospholipase C-gamma2, and extracellular signal regulated kinases 1 and 2, and
normal FcgammaR-dependent phagocytosis. These data suggest that both SLP-76 and
BLNK are coupled to FcgammaR signaling in murine macrophages.
PMID- 10677526
TI - Polycystin 1 is required for the structural integrity of blood vessels.
AB - Autosomal dominant polycystic kidney disease (ADPKD), often caused by mutations
in the PKD1 gene, is associated with life-threatening vascular abnormalities that
are commonly attributed to the frequent occurrence of hypertension. A previously
reported targeted mutation of the mouse homologue of PKD1 was not associated with
vascular fragility, leading to the suggestion that the vascular lesion may be of
a secondary nature. Here we demonstrate a primary role of PKD1 mutations in
vascular fragility. Mouse embryos homozygous for the mutant allele (Pkd1(L))
exhibit s.c. edema, vascular leaks, and rupture of blood vessels, culminating in
embryonic lethality at embryonic day 15.5. Kidney and pancreatic ductal cysts are
present. The Pkd1-encoded protein, mouse polycystin 1, was detected in normal
endothelium and the surrounding vascular smooth muscle cells. These data reveal a
requisite role for polycystin 1 in maintaining the structural integrity of the
vasculature as well as epithelium and suggest that the nature of the PKD1
mutation contributes to the phenotypic variance in ADPKD.
PMID- 10677527
TI - Regulated expression of P210 Bcr-Abl during embryonic stem cell differentiation
stimulates multipotential progenitor expansion and myeloid cell fate.
AB - P210 Bcr-Abl is an activated tyrosine kinase oncogene encoded by the Philadelphia
chromosome associated with human chronic myelogenous leukemia (CML). The disease
represents a clonal disorder arising in the pluripotent hematopoietic stem cell.
During the chronic phase, patients present with a dramatic expansion of myeloid
cells and a mild anemia. Retroviral gene transfer and transgenic expression in
rodents have demonstrated the ability of Bcr-Abl to induce various types of
leukemia. However, study of human CML or rodent models has not determined the
direct and immediate effects of Bcr-Abl on hematopoietic cells from those
requiring secondary genetic or epigenetic changes selected during the pathogenic
process. We utilized tetracycline-regulated expression of Bcr-Abl from a promoter
engineered for robust expression in primitive stem cells through multilineage
blood cell development in combination with the in vitro differentiation of
embryonal stem cells into hematopoietic elements. Our results demonstrate that
Bcr-Abl expression alone is sufficient to increase the number of multipotent and
myeloid lineage committed progenitors in a dose-dependent manner while
suppressing the development of committed erythroid progenitors. These effects are
reversible upon extinguishing Bcr-Abl expression. These findings are consistent
with Bcr-Abl being the sole genetic change needed for the establishment of the
chronic phase of CML and provide a powerful system for the analysis of any
genetic change that alters cell growth and lineage choices of the hematopoietic
stem cell.
PMID- 10677528
TI - Cardiolipin is a normal component of human plasma lipoproteins.
AB - Anticardiolipin (anti-CL) antibodies, diagnostic for antiphospholipid antibody
syndrome, are associated with increased risks of venous and arterial thrombosis.
Because CL selectively enhances activated protein C/protein S-dependent
anticoagulant activities in purified systems and because CL is not known to be a
normal plasma component, we searched for CL in plasma. Plasma lipid extracts
[chloroform/methanol (2:1, vol/vol)] were subjected to analyses by using TLC,
analytical HPLC, and MS. A plasma lipid component was purified that was
indistinguishable from reference CL (M:1448). When CL in 40 fasting plasma lipid
extracts (20 males, 20 females) was quantitated by using HPLC, CL (mean +/- SD)
was 14.9 +/- 3.7 microgram/ml (range 9.1 to 24.2) and CL was not correlated with
phosphatidylserine (3.8 +/- 1.7 microgram/ml), phosphatidylethanolamine (64 +/-
20 microgram/ml), or choline-containing phospholipid (1,580 +/- 280
microgram/ml). Based on studies of fasting blood donors, CL (>/=94%) was
recovered in very low density, low density, and high density lipoproteins (11 +/-
5.3%, 67 +/- 11.0%, and 17 +/- 10%, respectively), showing that the majority of
plasma CL (67%) is in low density lipoprotein. Analysis of relative phospholipid
contents of lipoproteins indicated that high density lipoprotein is selectively
enriched in CL and phosphatidylethanolamine. These results shows that CL is a
normal plasma component and suggest that the epitopes of antiphospholipid
antibodies could include CL or oxidized CL in lipoproteins or in complexes with
plasma proteins (e. g., beta(2)-glycoprotein I, prothrombin, protein C, or
protein S) or with platelet or endothelial surface proteins.
PMID- 10677529
TI - Phosphatidylinositol 3-kinase signaling mediates angiogenesis and expression of
vascular endothelial growth factor in endothelial cells.
AB - Phosphatidylinositol 3-kinase (PI 3-kinase) is a signaling molecule that controls
numerous cellular properties and activities. The oncogene v-p3k is a homolog of
the gene coding for the catalytic subunit of PI 3-kinase, p110alpha. P3k induces
transformation of cells in culture, formation of hemangiosarcomas in young
chickens, and myogenic differentiation in myoblasts. Here, we describe a role of
PI 3-kinase in angiogenesis. Overexpression of the v-P3k protein or of cellular
PI 3-kinase equipped with a myristylation signal, Myr-P3k, can induce
angiogenesis in the chorioallantoic membrane (CAM) of the chicken embryo. This
process is characterized by extensive sprouting of new blood vessels and
enlargement of preexisting vessels. Overexpression of the myristylated form of
the PI 3-kinase target Akt, Myr-Akt, also induces angiogenesis. Overexpression of
the tumor suppressor PTEN or of dominant-negative constructs of PI 3-kinase
inhibits angiogenesis in the yolk sac of chicken embryos, suggesting that PI 3
kinase and Akt signaling is required for normal embryonal angiogenesis. The
levels of mRNA for vascular endothelial growth factor (VEGF) are elevated in
cells expressing activated PI 3-kinase or Myr-Akt. VEGF mRNA levels are also
increased by insulin treatment through the PI 3-kinase-dependent pathway. VEGF
mRNA levels are decreased in cells treated with the PI 3-kinase inhibitor
LY294002 and restored by overexpression of v-P3k or Myr-Akt. Overexpression of
VEGF by the RCAS vector induces angiogenesis in chicken embryos. These results
suggest that PI 3-kinase plays an important role in angiogenesis and regulates
VEGF expression.
PMID- 10677530
TI - Combined effect of tumor necrosis factor-related apoptosis-inducing ligand and
ionizing radiation in breast cancer therapy.
AB - Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent
endogenous activator of the cell death pathway and functions by activating the
cell surface death receptors 4 and 5 (DR4 and DR5). TRAIL is nontoxic in vivo and
preferentially kills neoplastically transformed cells over normal cells by an
undefined mechanism. Radiotherapy is a common treatment for breast cancer as well
as many other cancers. Here we demonstrate that ionizing radiation can sensitize
breast carcinoma cells to TRAIL-induced apoptosis. This synergistic effect is p53
dependent and may be the result of radiation-induced up-regulation of the TRAIL
receptor DR5. Importantly, TRAIL and ionizing radiation have a synergistic effect
in the regression of established breast cancer xenografts. Changes in tumor
cellularity and extracellular space were monitored in vivo by diffusion-weighted
magnetic resonance imaging (diffusion MRI), a noninvasive technique to produce
quantitative images of the apparent mobility of water within a tissue. Increased
water mobility was observed in combined TRAIL- and radiation-treated tumors but
not in tumors treated with TRAIL or radiation alone. Histological analysis
confirmed the loss of cellularity and increased numbers of apoptotic cells in
TRAIL- and radiation-treated tumors. Taken together, our results provide support
for combining radiation with TRAIL to improve tumor eradication and suggest that
efficacy of apoptosis-inducing cancer therapies may be monitored noninvasively,
using diffusion MRI.
PMID- 10677531
TI - Human AML1/MDS1/EVI1 fusion protein induces an acute myelogenous leukemia (AML)
in mice: a model for human AML.
AB - The human t(3;21)(q26;q22) translocation is found as a secondary mutation in some
cases of chronic myelogenous leukemia during the blast phase and in therapy
related myelodysplasia and acute myelogenous leukemia. One result of this
translocation is a fusion between the AML1, MDS1, and EVI1 genes, which encodes a
transcription factor of approximately 200 kDa. The role of the AML1/MDS1/EVI1
(AME) fusion gene in leukemogenesis is largely unknown. In this study, we
analyzed the effect of the AME fusion gene in vivo by expressing it in mouse bone
marrow cells via retroviral transduction. We found that mice transplanted with
AME-transduced bone marrow cells suffered from an acute myelogenous leukemia
(AML) 5-13 mo after transplantation. The disease could be readily transferred
into secondary recipients with a much shorter latency. Morphological analysis of
peripheral blood and bone marrow smears demonstrated the presence of myeloid
blast cells and differentiated but immature cells of both myelocytic and
monocytic lineages. Cytochemical and flow cytometric analysis confirmed that
these mice had a disease similar to the human acute myelomonocytic leukemia. This
murine model for AME-induced AML will help dissect the molecular mechanism of AML
and the molecular biology of the AML1, MDS1, and EVI1 genes.
PMID- 10677532
TI - Identification of a Plasmodium falciparum intercellular adhesion molecule-1
binding domain: a parasite adhesion trait implicated in cerebral malaria.
AB - Binding of infected erythrocytes to brain venules is a central pathogenic event
in the lethal malaria disease complication, cerebral malaria. The only parasite
adhesion trait linked to cerebral sequestration is binding to intercellular
adhesion molecule-1 (ICAM-1). In this report, we show that Plasmodium falciparum
erythrocyte membrane protein 1 (PfEMP1) binds ICAM-1. We have cloned and
expressed PfEMP1 recombinant proteins from the A4tres parasite. Using
heterologous expression in mammalian cells, the minimal ICAM-1 binding domain was
a complex domain consisting of the second Duffy binding-like (DBL) domain and the
C2 domain. Constructs that contained either domain alone did not bind ICAM-1.
Based on phylogenetic criteria, there are five distinct PfEMP1 DBL types
designated alpha, beta, gamma, delta, and epsilon. The DBL domain from the A4tres
that binds ICAM-1 is DBLbeta type. A PfEMP1 cloned from a distinct ICAM-1 binding
variant, the A4 parasite, contains a DBLbeta domain and a C2 domain in tandem
arrangement similar to the A4tres PfEMP1. Anti-PfEMP1 antisera implicate the
DBLbeta domain from A4var PfEMP1 in ICAM-1 adhesion. The identification of a P.
falciparum ICAM-1 binding domain may clarify mechanisms responsible for the
pathogenesis of cerebral malaria and lead to interventions or vaccines that
reduce malarial disease.
PMID- 10677533
TI - Generation of in vivo activating factors in the ischemic intestine by pancreatic
enzymes.
AB - One of the early events in physiological shock is the generation of activators
for leukocytes, endothelial cells, and other cells in the cardiovascular system.
The mechanism by which these activators are produced has remained unresolved. We
examine here the hypothesis that pancreatic digestive enzymes in the ischemic
intestine may be involved in the generation of activators during intestinal
ischemia. The lumen of the small intestine of rats was continuously perfused with
saline containing a broadly acting pancreatic enzyme inhibitor (6-amidino-2
naphthyl p-guanidinobenzoate dimethanesulfate, 0.37 mM) before and during
ischemia of the small intestine by splanchnic artery occlusion. This procedure
inhibited activation of circulating leukocytes during occlusion and reperfusion.
It also prevented the appearance of activators in portal venous and systemic
artery plasma and attenuated initiating symptoms of multiple organ injury in
shock. Intestinal tissue produces only low levels of activators in the absence of
pancreatic enzymes, whereas in the presence of enzymes, activators are produced
in a concentration- and time-dependent fashion. The results indicate that
pancreatic digestive enzymes in the ischemic intestine serve as an important
source for cell activation and inflammation, as well as multiple organ failure.
PMID- 10677534
TI - Global analysis of gene expression in pulmonary fibrosis reveals distinct
programs regulating lung inflammation and fibrosis.
AB - The molecular mechanisms of pulmonary fibrosis are poorly understood. We have
used oligonucleotide arrays to analyze the gene expression programs that underlie
pulmonary fibrosis in response to bleomycin, a drug that causes lung inflammation
and fibrosis, in two strains of susceptible mice (129 and C57BL/6). We then
compared the gene expression patterns in these mice with 129 mice carrying a null
mutation in the epithelial-restricted integrin beta6 subunit (beta6(-/-)), which
develop inflammation but are protected from pulmonary fibrosis. Cluster analysis
identified two distinct groups of genes involved in the inflammatory and fibrotic
responses. Analysis of gene expression at multiple time points after bleomycin
administration revealed sequential induction of subsets of genes that
characterize each response. The availability of this comprehensive data set
should accelerate the development of more effective strategies for intervention
at the various stages in the development of fibrotic diseases of the lungs and
other organs.
PMID- 10677535
TI - Lipotoxic heart disease in obese rats: implications for human obesity.
AB - To determine the mechanism of the cardiac dilatation and reduced contractility of
obese Zucker Diabetic Fatty rats, myocardial triacylglycerol (TG) was assayed
chemically and morphologically. TG was high because of underexpression of fatty
acid oxidative enzymes and their transcription factor, peroxisome proliferator
activated receptor-alpha. Levels of ceramide, a mediator of apoptosis, were 2-3
times those of controls and inducible nitric oxide synthase levels were 4 times
greater than normal. Myocardial DNA laddering, an index of apoptosis, reached 20
times the normal level. Troglitazone therapy lowered myocardial TG and ceramide
and completely prevented DNA laddering and loss of cardiac function. In this
paper, we conclude that cardiac dysfunction in obesity is caused by lipoapoptosis
and is prevented by reducing cardiac lipids.
PMID- 10677536
TI - Chemical chaperones mediate increased secretion of mutant alpha 1-antitrypsin
(alpha 1-AT) Z: A potential pharmacological strategy for prevention of liver
injury and emphysema in alpha 1-AT deficiency.
AB - In alpha1-AT deficiency, a misfolded but functionally active mutant alpha1-ATZ
(alpha1-ATZ) molecule is retained in the endoplasmic reticulum of liver cells
rather than secreted into the blood and body fluids. Emphysema is thought to be
caused by the lack of circulating alpha1-AT to inhibit neutrophil elastase in the
lung. Liver injury is thought to be caused by the hepatotoxic effects of the
retained alpha1-ATZ. In this study, we show that several "chemical chaperones,"
which have been shown to reverse the cellular mislocalization or misfolding of
other mutant plasma membrane, nuclear, and cytoplasmic proteins, mediate
increased secretion of alpha1-ATZ. In particular, 4-phenylbutyric acid (PBA)
mediated a marked increase in secretion of functionally active alpha1-ATZ in a
model cell culture system. Moreover, oral administration of PBA was well
tolerated by PiZ mice (transgenic for the human alpha1-ATZ gene) and consistently
mediated an increase in blood levels of human alpha1-AT reaching 20-50% of the
levels present in PiM mice and normal humans. Because clinical studies have
suggested that only partial correction is needed for prevention of both liver and
lung injury in alpha1-AT deficiency and PBA has been used safely in humans, it
constitutes an excellent candidate for chemoprophylaxis of target organ injury in
alpha1-AT deficiency.
PMID- 10677537
TI - Cure of human carcinoma xenografts by a single dose of pretargeted yttrium-90
with negligible toxicity.
AB - A covalent conjugate (NR-LU-10/SA) was prepared between streptavidin (SA) and NR
LU-10, a mAb that binds an antigen expressed on the surface of most human
carcinomas. NR-LU-10/SA was injected into nude mice bearing human tumor
xenografts. Injection of biotinylated galactosyl-human serum albumin reduced the
circulating levels of conjugate by 95%. Subsequent administration of (90)Y-1,4,7,
10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-biotin achieved peak uptake at
the tumor within 2 hr while >80% of the radioactivity was eliminated in the
urine. A single dose of 600-800 microCi of (90)Y-1,4,7,10-tetraazacyclododecane
1,4,7,10-tetraacetic acid-biotin produced cures in 10/10 mice with established
(>200 mm(3)) s.c. human small cell lung or colon cancer xenografts and 8/10 cures
in mice with human breast cancer xenografts without significant toxicity.
PMID- 10677538
TI - Facilitated diffusion of fructose via the phosphoenolpyruvate/glucose
phosphotransferase system of Escherichia coli.
AB - From mutants of Escherichia coli unable to utilize fructose via the
phosphoenolpyruvate/glycose phosphotransferase system (PTS), further mutants were
selected that grow on fructose as the sole carbon source, albeit with relatively
low affinity for that hexose (K(m) for growth approximately 8 mM but with V(max)
for generation time approximately 1 h 10 min); the fructose thus taken into the
cells is phosphorylated to fructose 6-phosphate by ATP and a cytosolic
fructo(manno)kinase (Mak). The gene effecting the translocation of fructose was
identified by Hfr-mediated conjugations and by phage-mediated transduction as
specifying an isoform of the membrane-spanning enzyme II(Glc) of the PTS, which
we designate ptsG-F. Exconjugants that had acquired ptsG(+) from Hfr strains used
for mapping (designated ptsG-I) grew very poorly on fructose (V(max)
approximately 7 h 20 min), even though they were rich in Mak activity. A mutant
of E. coli also rich in Mak but unable to grow on glucose by virtue of transposon
mediated inactivations both of ptsG and of the genes specifying enzyme II(Man)
(manXYZ) was restored to growth on glucose by plasmids containing either ptsG-F
or ptsG-I, but only the former restored growth on fructose. Sequence analysis
showed that the difference between these two forms of ptsG, which was reflected
also by differences in the rates at which they translocated mannose and glucose
analogs such as methyl alpha-glucoside and 2-deoxyglucose, resided in a
substitution of G in ptsG-I by T in ptsG-F in the first position of codon 12,
with consequent replacement of valine by phenylalanine in the deduced amino acid
sequence.
PMID- 10677539
TI - A herpes simplex virus 1 recombinant lacking the glycoprotein G coding sequences
is defective in entry through apical surfaces of polarized epithelial cells in
culture and in vivo.
AB - During infection of a new host, the first surfaces encountered by herpes simplex
viruses are the apical membranes of epithelial cells of mucosal surfaces. These
cells are highly polarized, and the protein composition of their apical and
basolateral membranes are very different, so that different viral entry pathways
have evolved for each surface. To determine whether the viral glycoprotein G (gG)
is specifically required for efficient infection of a particular surface of
polarized cells, apical and basal surfaces were infected with wild-type virus or
a gG deletion mutant. After infection of polarized cells in culture, the gG(-)
virus was deficient in infection of apical surfaces but was able to infect cells
through basal membranes, replicate, and spread into surrounding cells. The gG
dependent step in apical infection was a stage beyond attachment. After in vivo
infection of apical surfaces of epithelial cells of nonscarified mouse corneas,
infection by glycoprotein C(-) or gG(-) virus was considerably reduced as
compared with that observed after infection with wild-type virus. In contrast,
when corneas were scarified, allowing virus access to other cell surfaces, the gG
and glycoprotein C deletion mutants infected eyes as efficiently as wild-type
viruses. A secondary mutation allowing infection of apical surfaces by gG(-)
virus arose readily during passage of the virus in nonpolarized cells, indicating
that either the gG-dependent step of apical infection can be bypassed or that
another viral protein can acquire the same function.
PMID- 10677540
TI - Importance of newly generated neurons in the adult olfactory bulb for odor
discrimination.
AB - In adult rodents, neurons are continually generated in the subventricular zone of
the forebrain, from where they migrate tangentially toward the olfactory bulb,
the only known target for these neuronal precursors. Within the main olfactory
bulb, they ascend radially into the granule and periglomerular cell layers, where
they differentiate mainly into local interneurons. The functional consequences of
this permanent generation and integration of new neurons into existing circuits
are unknown. To address this question, we used neural cell adhesion molecule
deficient mice that have documented deficits in the migration of olfactory-bulb
neuron precursors, leading to about 40% size reduction of this structure. Our
anatomical study reveals that this reduction is restricted to the granule cell
layer, a structure that contains exclusively gamma-aminobutyric acid (GABA)ergic
interneurons. Furthermore, mutant mice were subjected to experiments designed to
examine the behavioral consequences of such anatomical alteration. We found that
the specific reduction in the newly generated interneuron population resulted in
an impairment of discrimination between odors. In contrast, both the detection
thresholds for odors and short-term olfactory memory were unaltered,
demonstrating that a critical number of bulbar granule cells is crucial only for
odor discrimination but not for general olfactory functions.
PMID- 10677541
TI - Activation of a heterologously expressed octopamine receptor coupled only to
adenylyl cyclase produces all the features of presynaptic facilitation in aplysia
sensory neurons.
AB - Short-term behavioral sensitization of the gill-withdrawal reflex after tail
stimuli in Aplysia leads to an enhancement of the connections between sensory and
motor neurons of this reflex. Both behavioral sensitization and enhancement of
the connection between sensory and motor neurons are importantly mediated by
serotonin. Serotonin activates two types of receptors in the sensory neurons, one
of which is coupled to the cAMP/protein kinase A (PKA) pathway and the other to
the inositol triphosphate/protein kinase C (PKC) pathway. Here we describe a
genetic approach to assessing the isolated contribution of the PKA pathway to
short-term facilitation. We have cloned from Aplysia an octopamine receptor gene,
Ap oa(1), that couples selectively to the cAMP/PKA pathway. We have ectopically
expressed this receptor in Aplysia sensory neurons of the pleural ganglia, where
it is not normally expressed. Activation of this receptor by octopamine
stimulates all four presynaptic events involved in short-term synaptic
facilitation that are normally produced by serotonin: (i) membrane
depolarization; (ii) increased membrane excitability; (iii) increased spike
duration; and (iv) presynaptic facilitation. These results indicate that the
cAMP/PKA pathway alone is sufficient to produce all the features of presynaptic
facilitation.
PMID- 10677542
TI - An electric lobe suppressor for a yeast choline transport mutation belongs to a
new family of transporter-like proteins.
AB - Choline is an important metabolite in all cells due to the major contribution of
phosphatidylcholine to the production of membranes, but it takes on an added role
in cholinergic neurons where it participates in the synthesis of the
neurotransmitter acetylcholine. We have cloned a suppressor for a yeast choline
transport mutation from a Torpedo electric lobe yeast expression library by
functional complementation. The full-length clone encodes a protein with 10
putative transmembrane domains, two of which contain transporter-like motifs, and
whose expression increased high-affinity choline uptake in mutant yeast. The gene
was called CTL1 for its choline transporter-like properties. The homologous rat
gene, rCTL1, was isolated and found to be highly expressed as a 3. 5-kb
transcript in the spinal cord and brain and as a 5-kb transcript in the colon. In
situ hybridization showed strong expression of rCTL1 in motor neurons and
oligodendrocytes and to a lesser extent in various neuronal populations
throughout the rat brain. High levels of rCTL1 were also identified in the
mucosal cell layer of the colon. Although the sequence of the CTL1 gene shows
clear homology with a single gene in Caenorhabditis elegans, several homologous
genes are found in mammals (CTL2-4). These results establish a new family of
genes for transporter-like proteins in eukaryotes and suggest that one of its
members, CTL1, is involved in supplying choline to certain cell types, including
a specific subset of cholinergic neurons.
PMID- 10677543
TI - Columnar distribution of serotonin-dependent plasticity within kitten striate
cortex.
AB - Recent studies have identified the potential for an important role for serotonin
(5-HT) receptors in the developmental plasticity of the kitten visual cortex. 5
HT(2C) receptors are transiently expressed in a patchy fashion in the visual
cortex of kittens between 30-80 days of age complementary to patches demarcated
by cytochrome oxidase staining. 5-HT, operating via 5-HT(2C) receptors, increases
cortical synaptic plasticity as assessed both in brain slices and in vivo.
Herein, we report that bath application of 5-HT substantially increases the
probability of long-term potentiation within 5-HT(2C) receptor-rich zones of
cortex, but this effect is not observed in the 5-HT(2C) receptor-poor zones.
Instead, in these zones, 5-HT application increases the probability of long-term
depression. These location-specific effects of 5-HT may promote the formation of
compartment-specific cortical responses.
PMID- 10677544
TI - Poly(ADP-ribosyl)ation basally activated by DNA strand breaks reflects glutamate
nitric oxide neurotransmission.
AB - Poly(ADP-ribose) polymerase (PARP) transfers ADP ribose groups from NAD(+) to
nuclear proteins after activation by DNA strand breaks. PARP overactivation by
massive DNA damage causes cell death via NAD(+) and ATP depletion. Heretofore,
PARP has been thought to be inactive under basal physiologic conditions. We now
report high basal levels of PARP activity and DNA strand breaks in discrete
neuronal populations of the brain, in ventricular ependymal and subependymal
cells and in peripheral tissues. In some peripheral tissues, such as skeletal
muscle, spleen, heart, and kidney, PARP activity is reduced only partially in
mice with PARP-1 gene deletion (PARP-1(-/-)), implicating activity of alternative
forms of PARP. Glutamate neurotransmission involving N-methyl-d-aspartate (NMDA)
receptors and neuronal nitric oxide synthase (nNOS) activity in part mediates
neuronal DNA strand breaks and PARP activity, which are diminished by NMDA
antagonists and NOS inhibitors and also diminished in mice with targeted deletion
of nNOS gene (nNOS(-/-)). An increase in NAD(+) levels after treatment with NMDA
antagonists or NOS inhibitors, as well as in nNOS(-/-) mice, indicates that basal
glutamate-PARP activity regulates neuronal energy dynamics.
PMID- 10677545
TI - Carbon monoxide and nitric oxide as coneurotransmitters in the enteric nervous
system: evidence from genomic deletion of biosynthetic enzymes.
AB - Nitric oxide (NO) and carbon monoxide (CO) seem to be neurotransmitters in the
brain. The colocalization of their respective biosynthetic enzymes, neuronal NO
synthase (nNOS) and heme oxygenase-2 (HO2), in enteric neurons and altered
intestinal function in mice with genomic deletion of the enzymes
(nNOS(Delta/Delta) and HO2(Delta/Delta)) suggest neurotransmitter roles for NO
and CO in the enteric nervous system. We now establish that NO and CO are both
neurotransmitters that interact as cotransmitters. Small intestinal smooth muscle
cells from nNOS(Delta/Delta) and HO2(Delta/Delta) mice are depolarized, with
apparent additive effects in the double knockouts
(HO2(Delta/Delta)/nNOS(Delta/Delta)). Muscle relaxation and inhibitory
neurotransmission are reduced in the mutant mice. In HO2(Delta/Delta)
preparations, responses to electrical field stimulation are nearly abolished
despite persistent nNOS expression, whereas exogenous CO restores normal
responses, indicating that the NO system does not function in the absence of CO
generation.
PMID- 10677546
TI - Regulation of the phosphorylation of the dopamine- and cAMP-regulated
phosphoprotein of 32 kDa in vivo by dopamine D1, dopamine D2, and adenosine A2A
receptors.
AB - Dopamine D(1), dopamine D(2), and adenosine A(2A) receptors are highly expressed
in striatal medium-sized spiny neurons. We have examined, in vivo, the influence
of these receptors on the state of phosphorylation of the dopamine- and cAMP
regulated phosphoprotein of 32 kDa (DARPP-32). DARPP-32 is a potent endogenous
inhibitor of protein phosphatase-1, which plays an obligatory role in
dopaminergic transmission. A dose-dependent increase in the state of
phosphorylation of DARPP-32 occurred in mouse striatum after systemic
administration of the D(2) receptor antagonist eticlopride (0.1-2.0 mg/kg). This
effect was abolished in mice in which the gene coding for the adenosine A(2A)
receptor was disrupted by homologous recombination. A reduction was also observed
in mice that had been pretreated with the selective A(2A) receptor antagonist SCH
58261 (10 mg/kg). The eticlopride-induced increase in DARPP-32 phosphorylation
was also decreased by pretreatment with the D(1) receptor antagonist SCH 23390
(0.125 and 0.25 mg/kg) and completely reversed by combined pretreatment with SCH
23390 (0.25 mg/kg) plus SCH 58261 (10 mg/kg). SCH 23390, but not SCH 58261,
abolished the increase in DARPP-32 caused by cocaine (15 mg/kg). The results
indicate that, in vivo, the state of phosphorylation of DARPP-32 and, by
implication, the activity of protein phosphatase-1 are regulated by tonic
activation of D(1), D(2), and A(2A) receptors. The results also underscore the
fact that the adenosine system plays a role in the generation of responses to
dopamine D(2) antagonists in vivo.
PMID- 10677547
TI - Role of the cAMP signaling pathway in the regulation of gonadotropin-releasing
hormone secretion in GT1 cells.
AB - We studied the signaling pathways coupling gonadotropin-releasing hormone (GnRH)
secretion to elevations in cAMP levels in the GT1 GnRH-secreting neuronal cell
line. We hypothesized that increased cAMP could be acting directly by means of
cyclic nucleotide-gated (CNG) cation channels or indirectly by means of
activation of cAMP-dependent protein kinase (PKA). We showed that GT1 cells
express the three CNG subunits present in olfactory neurons (CNG2, -4.3, and -5)
and exhibit functional cAMP-gated cation channels. Activation of PKA does not
appear to be necessary for the stimulation of GnRH release by increased levels of
cAMP. In fact, pharmacological inhibition of PKA activity caused an increase in
the basal secretion of GnRH. Consistent with this observation activation PKA
inhibited adenylyl cyclase activity, presumably by inhibiting adenylyl cyclase V
expressed in the cells. Therefore, the stimulation of GnRH release by elevations
in cAMP appears to be the result of depolarization of the neurons initiated by
increased cation conductance by cAMP-gated cation channels. Activation of PKA may
constitute a negative-feedback mechanisms for lowering cAMP levels. We
hypothesize that these mechanisms could result in oscillations in cAMP levels,
providing a biochemical basis for timing the pulsatile release of GnRH.
PMID- 10677548
TI - Gamma rhythms and beta rhythms have different synchronization properties.
AB - Experimental and modeling efforts suggest that rhythms in the CA1 region of the
hippocampus that are in the beta range (12-29 Hz) have a different dynamical
structure than that of gamma (30-70 Hz). We use a simplified model to show that
the different rhythms employ different dynamical mechanisms to synchronize, based
on different ionic currents. The beta frequency is able to synchronize over long
conduction delays (corresponding to signals traveling a significant distance in
the brain) that apparently cannot be tolerated by gamma rhythms. The
synchronization properties are consistent with data suggesting that gamma rhythms
are used for relatively local computations whereas beta rhythms are used for
higher level interactions involving more distant structures.
PMID- 10677550
TI - Dopamine tone regulates D1 receptor trafficking and delivery in striatal neurons
in dopamine transporter-deficient mice.
AB - In vivo, G protein-coupled receptors (GPCR) for neurotransmitters undergo complex
intracellular trafficking that contribute to regulate their abundance at the cell
surface. Here, we report a previously undescribed alteration in the subcellular
localization of D1 dopamine receptor (D1R) that occurs in vivo in striatal
dopaminoceptive neurons in response to chronic and constitutive
hyperdopaminergia. Indeed, in mice lacking the dopamine transporter, D1R is in
abnormally low abundance at the plasma membrane of cell bodies and dendrites and
is largely accumulated in rough endoplasmic reticulum and Golgi apparatus.
Decrease of striatal extracellular dopamine concentration with 6-hydroxydopamine
(6- OHDA) in heterozygous mice restores delivery of the receptor from the
cytoplasm to the plasma membrane in cell bodies. These results demonstrate that,
in vivo, in the central nervous system, the storage in cytoplasmic compartments
involved in synthesis and the membrane delivery contribute to regulate GPCR
availability and abundance at the surface of the neurons under control of the
neurotransmitter tone. Such regulation may contribute to modulate receptivity of
neurons to their endogenous ligands and related exogenous drugs.
PMID- 10677549
TI - Circadian modulation of dopamine receptor responsiveness in Drosophila
melanogaster.
AB - We investigated the circadian function of Drosophila dopamine receptors by using
a behaviorally active decapitated preparation that allows for direct application
of drugs to the nerve cord. Quinpirole, a D2-like dopamine receptor agonist,
induces reflexive locomotion in decapitated flies. We show that the amount of
locomotion induced changes as a function of the time of day, with the highest
responsiveness to quinpirole during the subjective night. Furthermore, dopamine
receptor responsiveness is under circadian control and depends on the normal
function of the period gene. The head pacemaker is at least partly dispensable
for the circadian modulation of quinpirole-induced locomotion, because changes in
agonist responsiveness persist in decapitated flies that are aged for 12 h. This
finding suggests a role for the period-dependent molecular oscillators in the
body in the modulation of amine receptor responsiveness.
PMID- 10677551
TI - Induction of topoisomerase I cleavage complexes by 1-beta -D
arabinofuranosylcytosine (ara-C) in vitro and in ara-C-treated cells.
AB - 1-beta-d-Arabinofuranosylcytosine (Ara-C) is a nucleoside analog commonly used in
the treatment of leukemias. Ara-C inhibits DNA polymerases and can be
incorporated into DNA. Its mechanism of cytotoxicity is not fully understood.
Using oligonucleotides and purified human topoisomerase I (top1), we found a 4-
to 6-fold enhancement of top1 cleavage complexes when ara-C was incorporated at
the +1 position (immediately 3') relative to a unique top1 cleavage site. This
enhancement was primarily due to a reversible inhibition of top1-mediated DNA
religation. Because ara-C incorporation is known to alter base stacking and sugar
puckering at the misincorporation site and at the neighboring base pairs, the
observed inhibition of religation at the ara-C site suggests the importance of
the alignment of the 5'-hydroxyl end for religation with the phosphate group of
the top1 phosphotyrosine bond. This study also demonstrates that ara-C treatment
and DNA incorporation trap top1 cleavage complexes in human leukemia cells.
Finally, we report that camptothecin-resistant mouse P388/CPT45 cells with no
detectable top1 are crossresistant to ara-C, which suggests that top1 poisoning
is a potential mechanism for ara-C cytotoxicity.
PMID- 10677552
TI - Ascorbic acid acts as an inhibitory transmitter in the hypothalamus to inhibit
stimulated luteinizing hormone-releasing hormone release by scavenging nitric
oxide.
AB - Because ascorbic acid (AA) is concentrated in synaptic vesicles containing
glutamic acid, we hypothesized that AA might act as a neurotransmitter. Because
AA is an antioxidant, it might therefore inhibit nitric oxidergic (NOergic)
activation of luteinizing hormone-releasing hormone (LH-RH) release from medial
basal hypothalamic explants by chemically reducing NO. Cell membrane
depolarization induced by increased potassium concentration [K(+)] increased
medium concentrations of both AA and LH-RH. An inhibitor of NO synthase (NOS),
N(G)-monomethyl-l-arginine (NMMA), prevented the increase in medium
concentrations of AA and LH-RH induced by high [K(+)], suggesting that NO
mediates release of both AA and LH-RH. Calcium-free medium blocked not only the
increase in AA in the medium but also the release of LH-RH. Sodium nitroprusside,
which releases NO, stimulated LH-RH release and decreased the concentration of AA
in the incubation medium, presumably because the NO released oxidized AA to
dehydro-AA. AA (10(-5) to 10(-3) M) had no effect on basal LH-RH release but
completely blocked high [K(+)]- and nitroprusside-induced LH-RH release. N-Methyl
d-aspartic acid (NMDA), which mimics the action of the excitatory amino acid
neurotransmitter glutamic acid, releases LH-RH by releasing NO. AA (10(-5) to 10(
3) M) inhibited the LH-RH-releasing action of NMDA. AA may be an inhibitory
neurotransmitter that blocks NOergic stimulation of LH-RH release by chemically
reducing the NO released by the NOergic neurons.
PMID- 10677553
TI - Isolation and characterization of powdery mildew-resistant Arabidopsis mutants.
AB - A compatible interaction between a plant and a pathogen is the result of a
complex interplay between many factors of both plant and pathogen origin. Our
objective was to identify host factors involved in this interaction. These
factors may include susceptibility factors required for pathogen growth, factors
manipulated by the pathogen to inactivate or avoid host defenses, or negative
regulators of defense responses. To this end, we identified 20 recessive
Arabidopsis mutants that do not support normal growth of the powdery mildew
pathogen, Erysiphe cichoracearum. Complementation analyses indicated that four
loci, designated powdery mildew resistant 1-4 (pmr1-4), are defined by this
collection. These mutants do not constitutively accumulate elevated levels of PR1
or PDF1.2 mRNA, indicating that resistance is not simply due to constitutive
activation of the salicylic acid- or ethylene- and jasmonic acid-dependent
defense pathways. Further Northern blot analyses revealed that some mutants
accumulate higher levels of PR1 mRNA than wild type in response to infection by
powdery mildew. To test the specificity of the resistance, the pmr mutants were
challenged with other pathogens including Pseudomonas syringae, Peronospora
parasitica, and Erysiphe orontii. Surprisingly, one mutant, pmr1, was susceptible
to E. orontii, a very closely related powdery mildew, suggesting that a very
specific resistance mechanism is operating in this case. Another mutant, pmr4,
was resistant to P. parasitica, indicating that this resistance is more
generalized. Thus, we have identified a novel collection of mutants affecting
genes required for a compatible interaction between a plant and a biotrophic
pathogen.
PMID- 10677554
TI - UV light selectively coinduces supply pathways from primary metabolism and
flavonoid secondary product formation in parsley.
AB - The UV light-induced synthesis of UV-protective flavonoids diverts substantial
amounts of substrates from primary metabolism into secondary product formation
and thus causes major perturbations of the cellular homeostasis. Results from
this study show that the mRNAs encoding representative enzymes from various
supply pathways are coinduced in UV-irradiated parsley cells (Petroselinum
crispum) with two mRNAs of flavonoid glycoside biosynthesis, encoding
phenylalanine ammonia-lyase and chalcone synthase. Strong induction was observed
for mRNAs encoding glucose 6-phosphate dehydrogenase (carbohydrate metabolism,
providing substrates for the shikimate pathway), 3-deoxyarabinoheptulosonate 7
phosphate synthase (shikimate pathway, yielding phenylalanine), and acyl-CoA
oxidase (fatty acid degradation, yielding acetyl-CoA), and moderate induction for
an mRNA encoding S-adenosyl-homocysteine hydrolase (activated methyl cycle,
yielding S-adenosyl-methionine for B-ring methylation). Ten arbitrarily selected
mRNAs representing various unrelated metabolic activities remained unaffected.
Comparative analysis of acyl-CoA oxidase and chalcone synthase with respect to
mRNA expression modes and gene promoter structure and function revealed close
similarities. These results indicate a fine-tuned regulatory network integrating
those functionally related pathways of primary and secondary metabolism that are
specifically required for protective adaptation to UV irradiation. Although the
response of parsley cells to UV light is considerably broader than previously
assumed, it contrasts greatly with the extensive metabolic reprogramming observed
previously in elicitor-treated or fungus-infected cells.
PMID- 10677555
TI - The production of recombinant proteins in transgenic barley grains.
AB - The grain of the self-pollinating diploid barley species offers two modes of
producing recombinant enzymes or other proteins. One uses the promoters of genes
with aleurone-specific expression during germination and the signal peptide code
for export of the protein into the endosperm. The other uses promoters of the
structural genes for storage proteins deposited in the developing endosperm.
Production of a protein-engineered thermotolerant (1, 3-1, 4)-beta-glucanase with
the D hordein gene (Hor3-1) promoter during endosperm development was analyzed in
transgenic plants with four different constructs. High expression of the enzyme
and its activity in the endosperm of the mature grain required codon optimization
to a C+G content of 63% and synthesis as a precursor with a signal peptide for
transport through the endoplasmic reticulum and targeting into the storage
vacuoles. Synthesis of the recombinant enzyme in the aleurone of germinating
transgenic grain with an alpha-amylase promoter and the code for the export
signal peptide yielded approximately 1 microgram small middle dotmg(-1) soluble
protein, whereas 54 microgram small middle dotmg(-1) soluble protein was produced
on average in the maturing grain of 10 transgenic lines with the vector
containing the gene for the (1, 3-1, 4)-beta-glucanase under the control of the
Hor3-1 promoter.
PMID- 10677556
TI - The pollen determinant of self-incompatibility in Brassica campestris.
AB - Many flowering plants possess self-incompatibility (SI) systems that prevent
inbreeding. In Brassica, SI is controlled by a single polymorphic locus, the S
locus. Two highly polymorphic S locus genes, SLG (S locus glycoprotein) and SRK
(S receptor kinase), have been identified, both of which are expressed
predominantly in the stigmatic papillar cell. We have shown recently that SRK is
the determinant of the S haplotype specificity of the stigma. SRK is thought to
serve as a receptor for a pollen ligand, which presumably is encoded by another
polymorphic gene at the S locus. We previously have identified an S locus gene,
SP11 (S locus protein 11), of the S(9) haplotype of Brassica campestris and
proposed that it potentially encodes the pollen ligand. SP11 is a novel member of
the PCP (pollen coat protein) family of proteins, some members of which have been
shown to interact with SLG. In this work, we identified the SP11 gene from three
additional S haplotypes and further characterized the gene. We found that (i)
SP11 showed an S haplotype-specific sequence polymorphism; (ii) SP11 was located
in the immediate flanking region of the SRK gene of the four S haplotypes
examined; (iii) SP11 was expressed in the tapetum of the anther, a site
consistent with sporophytic control of Brassica SI; and (iv) recombinant SP11 of
the S(9) haplotype applied to papillar cells of S(9) stigmas, but not of S(8)
stigmas, elicited SI response, resulting in inhibition of hydration of cross
pollen. All these results taken together strongly suggest that SP11 is the pollen
S determinant in SI.
PMID- 10677557
TI - Elemental propagation of calcium signals in response-specific patterns determined
by environmental stimulus strength.
AB - Plant cells can respond qualitatively and quantitatively to a wide range of
environmental signals. Ca(2+) is used as an intracellular signal for volume
regulation in response to external osmotic changes. We show here that the
spatiotemporal patterns of hypo-osmotically induced Ca(2+) signals vary
dramatically with stimulus strength in embryonic cells of the marine alga Fucus.
Biphasic or multiphasic Ca(2+) signals reflect Ca(2+) elevations in distinct
cellular domains. These propagate via elemental Ca(2+) release in nuclear or
peripheral regions that are rich in endoplasmic reticulum. Cell volume regulation
specifically requires Ca(2+) elevation in apical peripheral regions, whereas an
altered cell division rate occurs only in response to stimuli that cause Ca(2+)
elevation in nuclear regions.
PMID- 10677559
TI - Parsing executive processes: strategic vs. evaluative functions of the anterior
cingulate cortex.
AB - Event-related functional MRI and a version of the Stroop color naming task were
used to test two conflicting theories of anterior cingulate cortex (ACC) function
during executive processes of cognition. A response-related increase in ACC
activity was present when strategic processes were less engaged, and conflict
high, but not when strategic processes were engaged and conflict reduced. This is
inconsistent with the widely held view that the ACC implements strategic
processes to reduce cognitive conflicts, such as response competition. Instead,
it suggests that the ACC serves an evaluative function, detecting cognitive
states such as response competition, which may lead to poor performance, and
representing the knowledge that strategic processes need to be engaged.
PMID- 10677558
TI - The epidemiology of antibiotic resistance in hospitals: paradoxes and
prescriptions.
AB - A simple mathematical model of bacterial transmission within a hospital was used
to study the effects of measures to control nosocomial transmission of bacteria
and reduce antimicrobial resistance in nosocomial pathogens. The model predicts
that: (i) Use of an antibiotic for which resistance is not yet present in a
hospital will be positively associated at the individual level (odds ratio) with
carriage of bacteria resistant to other antibiotics, but negatively associated at
the population level (prevalence). Thus inferences from individual risk factors
can yield misleading conclusions about the effect of antibiotic use on resistance
to another antibiotic. (ii) Nonspecific interventions that reduce transmission of
all bacteria within a hospital will disproportionately reduce the prevalence of
colonization with resistant bacteria. (iii) Changes in the prevalence of
resistance after a successful intervention will occur on a time scale of weeks to
months, considerably faster than in community-acquired infections. Moreover,
resistance can decline rapidly in a hospital even if it does not carry a fitness
cost. The predictions of the model are compared with those of other models and
published data. The implications for resistance control and study design are
discussed, along with the limitations and assumptions of the model.
PMID- 10677560
TI - Estrogen receptor variants are present in many normal human tissues.
AB - Estrogen receptors (ER) are present in various reproductive tissues as well as in
other tissues not considered classical targets for estrogen. A variety of
alternatively spliced ER variants which co-exist with the wild-type receptor has
also been described in many tissues. We analyzed the presence of both wild-type
and variant receptors from normal human tissues of various origin using semi
nested PCR and direct automated sequence of the amplified products. We
demonstrate that many normal human tissues of various origin contain a number of
spliced variants of the estrogen receptor that co-exist with the wild-type
receptor. Variants lacking exons 2, 4, 5, and 7 are detected in a variety of
normal human tissues.
PMID- 10677561
TI - Familial neurohypophyseal diabetes insipidus associated with a novel mutation in
the vasopressin-neurophysin II gene.
AB - Familial neurohypophyseal diabetes insipidus (FNDI) is an autosomal dominant
disorder of renal water conservation due to deficiency of arginine vasopressin as
the result of mutations in the arginine vasopressin-neurophysin II (AVP-NPII)
gene that encodes the hormone or its carrier protein. Thirty-one different
mutations have been reported. In this study, we evaluated the AVP-NPII gene in a
family with FNDI and identified a new mutation (1911Gright curved arrow A) in the
coding sequence for NPII in affected family members. This mutation substitutes
Tyr for 74 Cys in the NPII moiety. NPII is an intracellular carrier protein for
AVP during the axonal transport from the hypothalamus to the posterior pituitary
and contains 14 conserved cysteine residues forming 7 disulfide bonds. Because
the mutation cosegregates with the phenotype, it is possible that this mutation
causes neurohypophyseal diabetes insipidus in this family.
PMID- 10677562
TI - Spectral karyotyping and chromosome banding studies of primary breast carcinomas
and their lymph node metastases.
AB - Three primary breast tumors and their lymph node metastases were characterized by
G-banding, spectral karyotyping (SKY), and fluorescence in situ hybridization
(FISH). In each case, the karyotypic abnormalities detected were similar in the
primary tumor and its matched metastasis. Two of the pairs had near-diploid
karyotypes with three to four chromosomal aberrations, whereas the third pair had
a near-pentaploid chromosome content and many marker chromosomes in the primary
tumor and a near-tetraploid chromosome number with almost the same marker
chromosomes in the metastasis. SKY and FISH confirmed the karyotypic similarities
between the primary tumors and their metastases and, in addition, improved the
identification and characterization of marker chromosomes. One of the tumor pairs
with near-diploid karyotypes had gain of 8q, 16q, and 17q, whereas the other had
gain of 1q and chromosome 8 material in the form of ring chromosomes. The third
pair had more complex chromosomal translocations and numerical changes resulting
in net gain of material from chromosomes X, 1, 2, 6, 7, 14, 16, 19, and 20, and
chromosome arms 8q and 11q, as well as net loss of material from chromosomes 3,
13, 18, 21, and 22. The present study underscores the need to combine
conventional chromosome banding and molecular cytogenetic techniques in the
cytogenetic analysis of solid tumors.
PMID- 10677563
TI - Recombinant Semliki forest virus infects and kills human prostate cancer cell
lines and prostatic duct epithelial cells ex vivo.
AB - Semliki Forest Virus (SFV) is a broad host range RNA virus capable of high-level
recombinant protein expression and apoptosis induction in many cell types. We
have successfully used a recombinant, replication deficient SFV vector to express
the LacZ marker gene product in seven human prostate cell lines, as well as in
human prostate tissue explants. Flow cytometry revealed that 40-60% of PPC-1
prostate cancer cells died 24-72 h after infection with SFV-LacZ virus. Most
human prostate cancer cell lines expressed high levels of recombinant protein.
Infection of human prostate tissue ex vivo led to similarly high expression
levels but the recombinant beta-galactosidase was confined to duct epithelial
cells. Infection of cell and tissue cultures resulted in detachment of adherent
cells from the culture surface and detachment of epithelial cells from the
basement membrane of tissue. Our results indicate that SFV may be useful in
targeting recombinant protein expression and apoptosis to prostatic duct
epithelial cells.
PMID- 10677564
TI - Induction of the putative protective protein ferritin by infrared radiation:
implications in skin repair.
AB - The modification of ferritin in human skin cells in vitro and in vivo following
infrared-A irradiation by immunohistochemical analysis and ELISA were evaluated.
In addition, we observed that IR-A is not capable of inducing frank damage to DNA
(pyrimidine dimers, p53), induction of oxidative stress proteins (heme oxygenase,
nitric oxide, superoxide dismutase, heat shock proteins) or proteases
(collagenase, stromelysin, gelatinase) involved in carcinogenesis and photoaging
of the skin. in vivo, basal levels of ferritin were heterogeneous for all
individuals tested but all showed ferritin to stain precisely in the basal layer
of unirradiated epidermis. Following IR-A radiation, the ferritin increase was
localized to epidermal tissue and showed an increase from 120 to 220%. Parallel
to the in vivo analysis, dermal fibroblasts were cultured from six individuals.
Quantitative analysis for ferritin in cultured fibroblasts was assessed by ELISA
and increases were seen to be dose-dependent and up to 130% of basal levels of
ferritin following infrared-A. Our findings indicate that the putative defense
system of ferritin that exists in human skin in vivo can be induced by infrared-A
radiation and that these wavelengths may prove to be beneficial for human skin.
Importantly, following the same doses of IR-A that induced ferritin levels, there
was no alteration seen for nuclear DNA type damage, oxidative stress proteins or
proteases involved in the degradation of skin. The increased concentrations of
this antioxidant in human skin following acute UV radiation could afford
increased protection against subsequent oxidative stress.
PMID- 10677565
TI - Role of HIF-1 as a transcription factor involved in embryonic development, cancer
progression and apoptosis (review).
AB - Hypoxia-inducible factor-1 (HIF-1) is a transcription factor first identified as
being activated by hypoxia but also in normoxic conditions by insulin and IGF-2.
It is able to induce the expression of glycolytic genes and hence the ATP
production, it also regulates the expression of the angiogenic factor VEGF and
stimulates erythropoiesis via EPO production. HIF-1 is a protein necessary for
the normal embryonic and cardiovascular system development, but seems to be also
involved in cancer progression and apoptosis. Thus, it appears that HIF-1 plays a
central role in normal cellular functions and in tissue metabolism but it is also
involved in pathological evolutions raising its interest as a therapeutic target.
In this review, we summarize the dual role of HIF-1 as a major component of the
embryo development, as well as an element of tumor progression and of anoxia
induced apoptosis.
PMID- 10677566
TI - Suppressive effect of genistein on rat bone osteoclasts: involvement of protein
kinase inhibition and protein tyrosine phosphatase activation.
AB - The suppressive effect of genistein on osteoclast-like multinucleated cells from
rat femoral tissues was investigated. The bone cells isolated from rat femoral
tissues were cultured for 48 h in an alpha-minimal essential medium (5% fetal
bovine serum) containing either vehicle or genistein (10(-7)-10(-5) M).
Osteoclasts were estimated by staining for tartrate-resistant acid phosphatase, a
marker enzyme of osteoclasts. The presence of genistein caused a significant
decrease in the number of osteoclasts. Such a decrease was also seen in the
presence of calcium choride (10(-5) M). Magnesium chloride (10(-5)-10(-3) M), a
blocker of Ca2+ channels, had no effect on the number of osteoclasts. The effect
of genistein (10(-5) M) or calcium (10(-3) M) in decreasing osteoclasts was
significantly prevented by the presence of magnesium (10-3 M). Vanadate (10(-6)
10(-4) M), an inhibitor of protein tyrosine phosphatase activity, did not have an
effect on the number of osteoclasts. The genistein's effect was not altered by
vanadate. When isolated osteoclasts were cultured for 24 h in the presence of
genistein (10(-7)-10(-5) M), protein kinase activity in the 5500 g supernatant of
homogenate of the cells was significantly decreased, while protein tyrosine
phosphatase activity was significantly elevated. Such an effect was also seen by
the addition of genistein (10(-7)-10(-5) in the enzyme reaction mixture in vitro.
The present study suggests that the suppressive effect of genistein on rat bone
osteoclasts is partly involved in the inhibition of protein kinase and the
activation of protein tyrosine phosphatase in osteoclasts.
PMID- 10677567
TI - Molecular interactions between presenilin and calpain: inhibition of m-calpain
protease activity by presenilin-1, 2 and cleavage of presenilin-1 by m-, mu
calpain.
AB - Several mutations of presenilin (PS)-1, 2 result in early onset Alzheimer
disease. Using the yeast two-hybrid system, the interaction between PS2 loop
domain and the C-terminal region of mu-calpain was previously identified. Calpain
is a calcium dependent-protease and there are two isoforms, m-calpain and mu
calpain, which differ in the calcium concentration required for activation. m
Calpain needs about 10(-3) M calcium ions, whereas mu-calpain about 10(-5) M.
When PS and calpain were separately expressed in COS cells by cDNA transfection
and then combined in vitro, or both were co-transfected to be co-expressed in
vivo in COS cells, PS1 and PS2 reduced the casein proteolysis activity of m
calpain but not that of mu-calpain. Some of the PS mutations related to Alzheimer
disease decreased this inhibitory activity. On the other hand, PS1 was cleaved by
m-calpain and mu-calpain at a different site from those already reported
(constitutive cleavage or alternative cleavage). These results suggest a
regulatory function of presenilin on the calpain system.
PMID- 10677568
TI - Regression of experimental liver tumor after distant intra-hepatic injection of
cytosine deaminase-expressing tumor cells and 5-fluorocytosine treatment.
AB - Cytosine deaminase (CD) gene of E. coli converts the non-toxic compound 5
fluorocytosine (5-FC) into 5-fluorouracil. We have introduced a vector expressing
the CD gene in a rat colon carcinoma cell line. Expression of the CD gene confers
5-FC sensitivity to these cells in vitro and in vivo. In a bifocal model
consisting in a simultaneous engrafment of a CD+ tumor on one lobe of the liver
and a wild-type parental tumor on the opposite lobe, treatment with 5-FC results
in regression of both type of tumors, indicating the existence of a distant
bystander effect.
PMID- 10677569
TI - Cancer cell selectivity of 5-iodo-6-aminobenzopyrone (INH2BP) and methyl-3,5
diiodo-4(4'-methoxyphenoxy) benzoate (DIME).
AB - The cellular pharmacologic actions, as measured by cell killing, of INH2BP, DIME
and INO2BA (+ BSO) were determined in three types of cancer cells and compared to
their action on quiescent confluent human foreskin fibroblast (HSF) and pre
confluent growing fibroblasts. The confluent HSF cells were completely refractory
to the action of INH2BP and DIME, but were killed by INO2BA (+ BSO).
Proliferating HSF and all three tumor cell types were killed by all three drugs.
The apparent in vivo tumor specificity of INH2BP and DIME is explained by
preferential cell cycle dependent selective drug uptake into tumor cells and by
drug metabolism that reverses drug action in less vigorously cycling normal
cells. The covalent binding of iodonitrosobenzamide (formed from INO2BA) and its
toxicity are regulated by the concentration of GSH, and exhibit no cell cycle
selectivity.
PMID- 10677570
TI - Transcript heterogeneity of the human gene for Ca2+-binding protein regucalcin.
AB - Regucalcin is a Ca2+-binding protein which plays a regulatory role in liver cell
functions related to Ca2+. In this study we have cloned and characterized cDNA
for regucalcin from human liver and human hepatoma cell line Hep G2 by screening
and rapid amplification of cDNA ends (RACE). The nucleotide sequences of the
clones revealed that they were identical in their coding region and differed only
in their 5' untranslated regions (UTRs). Northern blot analysis showed that
regucalcin mRNA in the Hep G2 was longer than that of the liver. The present
study demonstrates the existence of transcript heterogeneity of the human gene
for regucalcin.
PMID- 10677571
TI - Immobilization of tumoral pancreatic islet cells on a two-dimensional
microsupport.
AB - A new procedure for the immobilization of tumoral pancreatic islet cells to a two
dimensional microsupport is presented. Tumoral islet cells of the RINm5F line
(0.7x10(6) cells/ml) were immobilized to two-dimensional microcarriers (16.6
cm2/ml). Within 24 h of culture, and as judged from the number of cells, their
protein or insulin content, less than 10% of the cells escaped immobilization.
The metabolic response of the immobilized cells to D-glucose was well preserved,
the paired ratio between D-[U-14C] glucose oxidation and D-[5-3H]glucose
utilization being even significantly higher in immobilized than free cells. The
advantages of this novel approach in the perspective of islet cell
transplantation are underlined.
PMID- 10677572
TI - The H9/M8166 tropism of various HIV-1 mutants is determined by distinct cellular
factors (review).
AB - We have previously shown that a number of human immunodeficiency virus type 1
(HIV-1) mutants generated in vitro display a replication-defect in a cell
dependent manner. Of the mutants of this category, those of gag, vif, and env
mutants do not grow at all in lymphocytic H9 (non-permissive) cells, but quite
well in M8166 (permissive) cells. To determine whether the cell-dependent growth
of the mutants is functionally related to each other, a number of double mutants
were constructed, and monitored for their replication and biochemical property in
various cells. The results obtained have indicated that there are multiple
cellular factors responsible for the growth phenotype. Together with our previous
findings on the host cell-dependent mutants of HIV-1, it is concluded that number
of distinct cellular factors are involved in the various steps in HIV-1
replication cycle.
PMID- 10677573
TI - Construction of new amplifier expression vectors for high levels of IL-2 gene
expression.
AB - The success of IL-2 gene therapy in cancer is in part dependent on the
development of high level IL-2 gene expression vectors. Currently, expression
vectors based on the human cytomegalovirus (CMV) promoter give the highest levels
of expression. We have attempted to construct new IL-2 expression vectors to test
whether gene expression can be further increased. The first approach was to use
the new SR-alpha promoter to control IL-2 gene expression. The second approach
was to combine the Tat transcription activator gene and the HIV 1 and 2 promoters
in the same construct so that the levels of gene expression can be amplified.
Transient transfection results using the human colon cancer cell line SW480
showed that the SR-alpha promoter yields similar levels of activity as the CMV
promoter. However, the HIV 1 and 2 promoter-based amplifier constructs produced
11 and 28 times more secreted IL-2 than the CMV promoter control. The augmented
activity of the amplifier constructs was dependent on the presence of the Tat
gene and the transcriptional units must be placed in the same orientation.
Reducing the size of the vectors by elimination of the neomycin selectable marker
did not increase the activity of the constructs.
PMID- 10677574
TI - Molecular medicine: the present and the future.
AB - In the recent past, major achievements have been obtained in the understanding of
the molecular defects at the basis of several different diseases. The field of
'Molecular Medicine' has thus become more solid, and several reports have been
published linking the basic molecular investigation to the clinical practice. In
line with this new approach to medicine a Symposium was organized where the
linkage between investigations in basic science could be explored in view of
clinical disorders, and vice versa. in Rosario, Argentina, September 9-11, 1999,
molecular biologists, molecular pathologists and clinicians discussed the
molecular defects possibly at the basis of some common diseases. This report
summarizes the presentations and discussions during the symposium.
PMID- 10677575
TI - Therapeutically targeting lymphocyte energy metabolism by high-dose
glucocorticoids.
AB - Lymphocytes use a considerable amount of energy, mainly in the form of ATP,
especially when they become stimulated following activation by antibodies or
mitogens. Cellular respiration is the major energy source, and in quiescent cells
the ATP produced is used to drive protein synthesis and sodium transport. In
stimulated cells there is significantly higher ATP production to balance the
higher ATP demand of specific processes resulting from activation. The major ATP
consuming processes under these conditions are protein synthesis and Na(+),K(+)
ATPase (about 20% each), while Ca(2+)-ATPase and RNA/DNA syntheses contribute
about 10% each. There is a wealth of available information about glucocorticoid
effects on lymphocytes, but here we focus on the extent to which this lymphocyte
bioenergetic machinery is targeted by glucocorticoids when they are used
therapeutically at high doses. High-dose glucocorticoids have been shown recently
to interfere with processes that are essential for the activation and maintenance
of lymphocytes, such as sodium and potassium transport. Therefore, in this
article we describe the bioenergetics of lymphocytes in resting, activated, and
glucocorticoid-treated states and present a concept for discussion to describe
the relationship among these states in fundamental and clinical terms.
PMID- 10677576
TI - Attenuation of interleukin-8 production by inhibiting nuclear factor-kappaB
translocation using decoy oligonucleotides.
AB - Interleukin-8 (IL-8), a monocyte-derived neutrophil chemoattractant factor, is a
polymorphonuclear neutrophil chemotaxin that is involved in a number of
inflammatory disorders. Transcription of the IL-8 gene is controlled by
regulatory proteins, including nuclear factor-kappaB (NF-kappaB), a family of
proteins that is important in the transcriptional control of a number of genes.
When cells are activated, NF-kappaB translocates from the cytoplasm to the
nucleus, where it activates transcription by binding to a specific sequence
within the 5' untranslated region of the gene. During translocation, NF-kappaB is
potentially susceptible to diversion by oligonucleotides that contain the binding
sequence for this protein. In the current study, we produced phosphorothioate
modified oligonucleotides containing the specific DNA sequence that NF-kappaB
binds within the IL-8 gene. We then investigated the effects of transfection of
monocytes with these oligonucleotides on interleukin-1beta (IL-1beta)-stimulated
IL-8 production, IL-8 mRNA expression, and NF-kappaB binding activity. We found
that transfection with these oligonucleotides significantly inhibited monocyte IL
8 production. A single-stranded oligonucleotide with two copies of the NF-kappaB
binding sequence was the most potent of those tested. This single-stranded
oligonucleotide also inhibited IL-1beta-induced translocation of NF-kappaB to the
nucleus and reduced IL-8 mRNA expression. These studies demonstrated that
monocyte production of IL-8 can be attenuated using a single-stranded
oligonucleotide that binds a transcriptional activating protein before it
translocates to the cell nucleus. This approach ultimately may be useful in the
control of inflammation involved in a number of diseases.
PMID- 10677577
TI - Uptake of the nitroimidazole drug megazol by African trypanosomes.
AB - Megazol, CL 64,855 (2-amino-5-[1-methyl-5-nitro-2-imidazolyl]-1,3, 4-thiazole)
has been shown to be extremely effective in clearing experimental infections of
African trypanosomes. An unusual amino-purine transporter termed P2, implicated
in the transport of both the diamidine and melaminophenyl arsenical classes of
drug in Trypanosoma brucei, recognised chemical groups on compounds which are
also present on megazol. Megazol interacted with this carrier protein, as judged
by its ability to inhibit P2 adenosine transport and to abrogate in vitro
arsenical-induced lysis in a dose-dependent manner. However, parasites resistant
to melaminophenyl arsenical and diamidine drugs due to lack of the P2 transporter
showed no resistance to megazol. This is because passive diffusion represented
the major route of entry. Initial rates of uptake were not saturable within the
limit of megazol's solubility and did not conform to thermodynamic precepts
compatible with carrier-mediated uptake. Adenosine and other P2 transporter
substrates, even at high concentration, had little impact on megazol uptake.
Uptake was biphasic, with a very rapid equilibration across the membrane followed
by a slower accumulation over time. The equilibration phase represented a simple
passive diffusion, with the subsequent uptake probably being due to metabolism of
the drug.
PMID- 10677578
TI - Contribution of several metabolites of the vitamin D analog 20-epi-22-oxa
24a,26a,27a-tri-homo-1,25-(OH)(2) vitamin D(3) (KH 1060) to the overall
biological activity of KH1060 by a shared mechanism of action.
AB - The synthetic 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) analog 20-epi-22-oxa
24a,26a,27a-tri-homo-1,25-(OH)(2)vitamin D(3) (KH1060) is considerably more
potent than its cognate hormone. The mechanism of action of KH1060 includes
interaction with the vitamin D receptor (VDR). We previously showed that KH1060
increases VDR stability in ROS 17/2.8 osteoblastic cells by inducing a specific
conformational change in the VDR. KH1060 is metabolized, both in vivo and in
vitro, into several stable products. In the present study, we investigated
whether these metabolites might contribute to the increased biological activity
of KH1060. We found that the potencies of two of these metabolites, 24a-OH-KH1060
and 26-OH-KH1060, were similar to that of 1,25-(OH)(2)D(3) in inducing
osteocalcin production by the osteoblast cell line ROS 17/2.8. This report
further showed that these metabolites had the same effects as KH1060 on VDR: they
increased VDR stability in ROS 17/2.8 cells, while limited proteolytic analysis
revealed that they caused a conformational change in the VDR, resulting in an
increased resistance against proteolytic cleavage. Furthermore, as shown in gel
mobility shift assays, both compounds clearly induced VDR binding to vitamin D
response elements. Together, these results show that the potent in vitro activity
of KH1060 is not only directed by the effects on the VDR
conformation/stabilization of the analog itself, but also by certain of its long
lived metabolites, and emphasizes the importance of detailed knowledge of the
metabolism of synthetic hormonal analogs.
PMID- 10677579
TI - Camptothecin-stabilised topoisomerase I-DNA complexes in leukaemia cells
visualised and quantified in situ by the TARDIS assay (trapped in agarose DNA
immunostaining).
AB - We have shown that the TARDIS assay (trapped in agarose DNA immunostaining) can
be used to detect DNA-topoisomerase I (topo I) cleavable complexes in situ in
individual cells following treatment with topo I-targeting drugs. This assay is a
modification of the assay for DNA-topoisomerase II (topo II) cleavable complexes
(Willmore et al., Mol Pharmacol 53: 78-85, 1998). Drug-stabilised topo I-DNA
complexes were detected in situ by topo I-specific primary antibodies and then
visualised using fluorescein isothiocyanate conjugated second antibodies.
Immunofluorescence was then quantified using a cooled slow-scan coupled device
camera and image analysis procedures. Camptothecin (CPT) was shown to stabilise
topo I-DNA cleavable complexes in whole cells in a dose-dependent manner in both
CCRF-CEM and K562 cells and in lymphoblasts from an adult with newly diagnosed
acute myeloid leukaemia treated ex vivo with CPT. In K562 cells, cleavable
complexes were found to be maximal between 30 and 90 minutes continuous exposure
of CPT, and approximately 78% of cleavable complexes formed in these cells were
found to be reversed within 5 minutes of drug removal. It has also been shown
that the immunofluorescence detected by the TARDIS assay was specific for topo I
targeting agents. Hence, the TARDIS assay provides a powerful tool to determine
the levels of drug-stabilised cleavable complexes in whole cells and thereby aid
in the understanding of the mechanism of interaction between topo I-targeting
drugs and their target.
PMID- 10677580
TI - A novel action of the antianginal drug bepredil: induction of internal Ca(2+)
release and external Ca(2+) influx in Madin-Darby canine kidney (MDCK) epithelial
cells.
AB - The effect of the antianginal drug bepridil on Ca(2+) signaling in Madin-Darby
canine kidney (MDCK) cells was investigated by using fura-2 as a Ca(2+) probe.
Bepridil at 10-50 microM evoked a significant rise in cytosolic free Ca(2+)
concentration ([Ca(2+)](i)) in a dose-dependent manner. The [Ca(2+)](i) rise
consisted of an immediate initial rise and a slow decay. Removal of external
Ca(2+) partly inhibited the Ca(2+) signals by reducing both the initial rise and
the decay phase, suggesting that bepridil activated both external Ca(2+) influx
and internal Ca(2+) release. In Ca(2+)-free medium, pretreatment with 50 microM
bepridil nearly abolished the Ca(2+) release induced by thapsigargin (1 microM),
an endoplasmic reticulum Ca(2+) pump inhibitor, and vice versa, pretreatment with
thapsigargin inhibited most of the bepridil-induced Ca(2+) release, suggesting
that the thapsigargin-sensitive Ca(2+) store was the main source of bepridil
induced Ca(2+) release. Bepridil (50 microM) induced considerable Mn(2+) quench
of fura-2 fluorescence at an excitation wavelength of 360 nm, which was partly
inhibited by La(3+) (0.1 mM). Consistently, La(3+) (0.1 mM) pretreatment
significantly inhibited the bepridil-induced [Ca(2+)](i) rise. Addition of 3 mM
Ca(2+) induced a significant [Ca(2+)](i) rise after prior incubation with 10-50
microM bepridil in Ca(2+)-free medium, suggesting that bepridil induced dose
dependent capacitative Ca(2+) entry. However, 50 microM bepridil inhibited 1
microM thapsigargin-induced capacitative Ca(2+) entry by 38%. Pretreatment with
aristolochic acid (40 microM) so as to inhibit phospholipase A(2) inhibited 50
microM bepridil-induced internal Ca(2+) release by 42%, but inhibition of
phospholipase C with U73122 (2 microM) or inhibition of phospholipase D with
propranolol (0.1 mM) had little effect, suggesting that bepridil induced internal
Ca(2+) release in an inositol 1,4,5-trisphosphate-independent manner that could
be modulated by phospholipase A(2)-coupled events. This is the first report
providing evidence that bepridil, currently used as an antianginal drug, induced
a rise in [Ca(2+)](i) in a non-excitable cell line.
PMID- 10677581
TI - Pharmacological properties of rat brain fatty acid amidohydrolase in different
subcellular fractions using palmitoylethanolamide as substrate.
AB - In the present study, the pharmacological properties of fatty acid amide
hydrolase (FAAH) in subcellular fractions of rat brain were investigated using
palmitoylethanolamide (PEA) and arachidonyl ethanolamide (anandamide, AEA) as
substrates. FAAH hydrolysed [(3)H]PEA in crude homogenates with median K(m) and
V(max) values of 2.9 microM and 2.14 nmol.(mg protein)(-1).min(-1), respectively.
[(3)H]PEA hydrolysis was inhibited both by non-radioactive AEA (with a K(i) value
very similar to the K(m) value for [(3)H]AEA as substrate using the same assay)
and by R(-)ibuprofen (mixed-type inhibition K(i) and K'(i) values 88 and 720
microM, respectively). FAAH activity towards both [(3)H]PEA and [(3) myelin =
cytosol, but there were no differences between the relative activities towards
the two substrates in any of the fractions. [(3)H]PEA hydrolysis in
mitochondrial, myelin, microsomal, and synaptosomal fractions was inhibited by
oleyl trifluoromethylketone, phenylmethylsulphonyl fluoride, and the R(-)- and
S(+)-enantiomers of the nonsteroidal anti-inflammatory drug ibuprofen, with mean
IC(50) values in the ranges 0.028-0.041, 0.37-0.52, 67-110, and 130-260 microM,
respectively. It is concluded that the pharmacological properties of FAAH in the
different subcellular fractions are very similar.
PMID- 10677582
TI - Biological activity of hexitol nucleic acids targeted at Ha-ras and intracellular
adhesion molecule-1 mRNA.
AB - Hexitol nucleic acid (HNA) is a new steric blocking oligonucleotide, hybridizing
sequence selectively with RNA. The biological activity of HNA was evaluated in an
in vitro translation arrest system targeting Ha-ras mRNA and in a cellular system
targeting intracellular adhesion molecule-1 (ICAM-1) expression. HNA very
efficiently and selectively inhibited Ha-ras mRNA translation (IC(50) of 50 nM)
when targeted at the translation initiation region. When targeting at the 12th
codon region, a gap-mer approach was needed to inhibit mRNA translation.
Similarly, HNA inhibited ICAM-1 expression in keratinocytes when targeting at
codon sequences. In this test system, HNA is less active but more selective than
phosphorothioates, but needs lipofection to become active in keratinocytes. This
new steric blocker may be an efficient antisense agent providing that enough
material can be brought into cells.
PMID- 10677583
TI - Effects of sodium deoxycholate and sodium caprate on the transport of epirubicin
in human intestinal epithelial Caco-2 cell layers and everted gut sacs of rats.
AB - The effects of sodium deoxycholate (Deo-Na), a bile salt, and sodium caprate (Cap
Na), a fatty acid, on the transport of epirubicin were investigated in both the
human colon adenocarcinoma (Caco-2) cell line and the everted gut sacs of the rat
jejunum and ileum. The possible use of these two potent absorption enhancers as
multidrug resistance (MDR) reversing agents also was examined. Epirubicin uptake
experiments using a flow cytometer showed that Deo-Na and Cap-Na significantly
increased the accumulation of epirubicin in Caco-2 cells. These two enhancers
significantly increased apical to basolateral absorption of epirubicin across
Caco-2 monolayers and mucosal to serosal absorption of epirubicin in the rat
jejunum and ileum. Moreover, the addition of Deo-Na or Cap-Na significantly
reduced the basolateral to apical efflux of epirubicin across Caco-2 monolayers.
The co-presence of verapamil, one typical P-glycoprotein (P-gp) substrate, and
Deo-Na or Cap-Na demonstrated further reduction of epirubicin efflux. The study
suggests that inhibition of P-gp or other transporter proteins located in the
intestines may be involved, at least partially, in the reduction of epirubicin
efflux. In conclusion, the therapeutic efficacy of epirubicin may be improved by
the use of such low toxicity excipients as absorption enhancers and MDR
modulators in formulations.
PMID- 10677584
TI - Effect of the beta-adrenoceptor agonist flerobuterol on serotonin synthesis in
the rat brain.
AB - The influence of 2- and 14-day treatments with flerobuterol, a preferential
beta(2)-adrenoceptor agonist, on regional serotonin (5-HT) synthesis in the rat
brain was studied by autoradiography using alpha-[(14)C]methyl-L-tryptophan.
Flerobuterol was delivered at a rate of 0.5 mg/kg/day using osmotic pumps
implanted s.c. The 2-day flerobuterol treatment significantly increased plasma
Trp, both free and total, and decreased plasma Leu and Ile. This resulted in a
significant increase in the facilitated transport of Trp. There was a significant
increase in the synthesis of 5-HT in the 2-day treatment group in the dorsal and
median raphe as well as in all postsynaptic structures, with the exception of the
hypothalamus. In contrast, after a 14-day treatment, the enhanced facilitated
transport of Trp was no longer present, and the increase in the rate of 5-HT
synthesis persisted only in the parietal and occipital cortex and the superior
colliculus. These data suggest that flerobuterol, similar to other beta
adrenergic agonists, acutely increases 5-HT synthesis, in part, through an
elevation of brain Trp availability.
PMID- 10677585
TI - The decrease in total collagen fibers in the liver by hepatocyte growth factor
after formation of cirrhosis induced by thioacetamide.
AB - Liver cirrhosis is an inveterate disease accompanying fibrosis, hepatocyte
damage, and liver dysfunction. In this study, the therapeutic effects of
recombinant human hepatocyte growth factor (rhHGF) on liver cirrhosis were
examined in rats administered thioacetamide (TAA). Repeated administration of TAA
for 10 weeks to rats induced liver cirrhosis with collagen nodes and pseudo-lobe
generation, a condition that was pathologically similar to that in humans.
Administration of rhHGF after the formation of liver cirrhosis markedly decreased
the incidence of pathological fibrosis and the degree of fibrosis as measured by
a computed image analysis system. Continuous administration of rhHGF by infusion
pump was more effective than bolus administration. Northern blotting analysis
showed that rhHGF reduced mRNA levels of procollagen alpha2(I), alpha1(IV), and
transforming growth factor-beta1 (TGF-beta1) that were stimulated in the TAA
treated liver. The labeling index of hepatocytes increased following
administration of rhHGF in this model. These observations suggest that the
pathological recession of liver fibrosis is the result of the reduction of TGF
beta1 and collagen synthesis and, in part, of the stimulation of mitosis of
hepatocytes directly by rhHGF and indirectly by TGF-beta1 reduction in the
cirrhotic liver. These results demonstrate the usefulness of rhHGF as a
therapeutic agent in liver cirrhosis.
PMID- 10677586
TI - Novel ring A stereoisomers of 2-methyl-1alpha,25-dihydroxyvitamin D(3) and 2
methyl-20-epi-1alpha,25-dihydroxyvitamin D(3): transactivation of target genes
and modulation of differentiation in human promyelocytic leukemia (HL-60) cells.
AB - We evaluated the biological activity of two sets of ring A stereoisomers of 2
methyl-1alpha,25-dihydroxyvitamin D(3) (2-methyl-1alpha,25(OH)(2)D(3)) and 2
methyl-20-epi-1alpha, 25-dihydroxyvitamin D(3) (2-methyl-20-epi
1alpha,25(OH)(2)D(3)) in terms of the following: transactivation of a rat 25
hydroxyvitamin D(3)-24-hydroxylase gene promoter including two vitamin D response
elements (VDREs) and a human osteocalcin gene promoter including a VDRE in
transfected human osteosarcoma (MG-63) cells; a vitamin D receptor (VDR)-mediated
response using a VDR-GAL4 one-hybrid luciferase reporter system and a retinoid X
receptor alpha (RXRalpha)-mediated response using an expressed VDR/RXRalpha-GAL4
modified two-hybrid luciferase reporter system in transfected human epitheloid
carcinoma, cervix (HeLa) cells; and modulation of cell surface CD11b antigen
expression in human leukemia (HL-60) cells. All the diastereomers of both
analogues exhibited unique biological activity profiles depending upon the
configurations of the C-1 and C-3 hydroxyl groups, the C-2 methyl group in ring
A, and the C-20 methyl group in the side chain. Of the eight possible
diastereomers of the 2-methyl analogues, 2alpha-methyl-1alpha,25(OH)(2)D(3) was
the most potent and exhibited comparable or even greater biological potency than
1alpha,25(OH)(2)D(3). Of the eight possible diastereomers of the 2-methyl-20-epi
analogues, 2alpha-methyl-20-epi-1alpha,25(OH)(2)D(3) was the most potent and
exhibited 100- to 200-fold higher transcriptional potencies than
1alpha,25(OH)(2)D(3) and exceptionally high cell regulatory activities. 2beta
methyl-20-epi-1alpha,25(OH)(2)D(3) was nearly as potent as its 2-epimer, 2alpha
methyl-20-epi-1alpha,25(OH)(2)D(3), whereas its 20-epimer, 2beta-methyl
1alpha,25(OH)(2)D(3), was almost completely biologically inactive. In these
respects, it can be postulated that the double modification of 2-methyl
substitution and 20-epimerization to 1alpha,25(OH)(2)D(3) induces remarkable
changes in a VDR/RXRalpha/VDRE-mediated signaling response and greatly enhances
biological activity. The other striking finding was that 2beta-methyl-20-epi-3
epi-1beta,25(OH)(2)D(3) is transcriptionally more active than
1alpha,25(OH)(2)D(3) despite lacking the 1alpha-hydroxyl group, which was
believed to be essential for expressing VDR-mediated gene transcription. Since
the C-20 natural counterpart, 2beta-methyl-3-epi-1beta,25(OH)(2)D(3), was almost
completely biologically inactive, 20-epimerization is probably responsible for
activation of gene expression. Although earlier extensive structure-activity
studies of vitamin D analogues showed stereochemistry at the C-1, C-3, and C-20
of 1alpha,25(OH)(2)D(3) to be the key structural motif for vitamin D action, our
results clearly demonstrated that stereochemistry at the C-2 is also an important
structural motif for vitamin D action and imply that 2-methyl substitution
possibly induces conformational changes in ring A depending upon the combinations
of configurations of the C-1 and C-3 hydroxyl groups with C-20 stereochemistry.
Consequently, several of these analogues exhibit exceptionally high or unexpected
biological activities at the molecular and cellular levels. These results suggest
that 2-methyl substitution together with alterations of stereochemistry in both
ring A and the side chain of 1alpha, 25(OH)(2)D(3) will provide useful analogues
for structure-activity studies and development of therapeutic agents with unique
biological activity profiles.
PMID- 10677587
TI - Comparison of oxidative stress response parameters in newborn mouse liver versus
simian virus 40 (SV40)-transformed hepatocyte cell lines.
AB - Induction of approximately one dozen genes and/or enzyme activities in liver of
the untreated newborn c(14CoS)/c(14CoS) mouse-when compared with the
c(ch)/c(14CoS) heterozygote or the c(ch)/c(ch) wild-type-is the result of
enhanced levels of reactive oxygenated metabolites originating from a block in
the tyrosine degradation pathway. Oxidative stress activates genes via the
electrophile response element, whereas dioxin activates genes via the receptor
mediated aromatic hydrocarbon response element. Here, we compared several
parameters in 14CoS/14CoS versus ch/ch newborn mouse liver with that in simian
virus 40 (SV40)-transformed hepatocyte lines that had been derived from newborn
liver. We showed in this study that: (a) NADP(H):quinone oxidoreductase and UDP
glucuronosyltransferase 1A6 mRNA levels were increased in both the (untreated)
14CoS/14CoS newborn liver and cell line; (b) aldehyde dehydrogenase 3A1 mRNA was
increased by both oxidative stress and dioxin in hepatocyte cultures, but was not
detectable in liver of the intact mouse; (c) the glutathione S-transferase GSTA1,
GSTP1, GSTA3, and GSTM1 mRNA levels were increased by oxidative stress in
14CoS/14CoS newborn liver, but these transcripts were either low or undetectable
in the cell lines; (d) GSTA1 mRNA was up-regulated by the absence of cytochrome
P450 1A1 (CYP1A1) activity (i.e. the Gsta1 gene is a member of the aromatic
hydrocarbon [Ah] battery); and (e) GSTP1 mRNA was not up-regulated by the absence
of CYP1A1 activity (i. e. Gstp1 is not a member of the [Ah] battery). The
14CoS/14CoS and ch/ch hepatocyte established cell lines were transformed with
SV40, which expresses large T antigen; this gene product is known to bind to, and
interact with, several cell cycle regulatory proteins such as p53 and the
retinoblastoma protein-E2F complex. It is therefore likely that differences in
the oxidative stress responses between the 14CoS/14CoS newborn liver and the
immortalized hepatocyte cell line might be explained by the presence of large T
antigen in the established cell line.
PMID- 10677588
TI - Expression of nitric oxide-sensitive guanylyl cyclase subunits in human corpus
cavernosum.
AB - The muscles of the corpus cavernosum of the penis relax in response to
stimulation of non-adrenergic, non-cholinergic nerves or nitric oxide (NO)
donating drugs to elicit erection. It is generally assumed that NO mediates this
effect via activation of soluble guanylyl cyclase and a subsequent increase in
cyclic guanosine 3', 5'-monophosphate concentration. However, there are no data
on the expression of this enzyme in human corpus cavernosum. The purpose of the
present study was the molecular characterization of NO-sensitive guanylyl cyclase
in human corpus cavernosum. RNA was extracted from tissue samples obtained from
seven patients undergoing penile prosthetic surgery or correction of penile
deviation. Reverse transcriptase-polymerase chain reaction (RT-PCR) with specific
primers for the subunits of NO-sensitive guanylyl cyclase was performed, and PCR
products were subcloned and sequenced. Specific amplification products encoding
the alpha(1), beta(1), alpha(2), and beta(2) subunits were detected. In addition,
we isolated a transcript encoding a novel variant beta(2) subunit. To test
whether this novel transcript arises by alternative splicing or whether it is
encoded by a separate gene, a 4000-bp clone of the corresponding genomic DNA
sequence was isolated. Sequence analysis suggests that the novel beta(2) variant
arises by alternative splicing from the same gene as the beta(2) subunit on
chromosome 13. In conclusion, our findings suggest the presence of different
subunit mRNAs of NO-sensitive guanylyl cyclase in human corpus cavernosum.
PMID- 10677589
TI - Inhibitory effects of aclarubicin on nitric oxide production in aortic smooth
muscle cells and macrophages.
AB - The effects of aclaruhicin (ACR), an anthracycline antibiotic, on inducible
nitric oxide (NO) synthesis was investigated in rat aortic smooth muscle cells
(RASMCs) and RAW macrophages. ACR at concentrations as low as 0.1 microM
significantly inhibited NO production induced by interleukin-1beta in RASMCs.
About 5- to 10-fold higher concentrations of ACR were required for inhibition of
interferon-gamma and lipopolipopolysaccharide-induced NO production in RAW cells.
When ACR was subsequently administered to inducible NO synthase (iNOS) induction,
the NO production was barely suppressed in RASMCs. Moreover, ACR (up to 10
microM) lacked direct inhibitory effects on iNOS activity in homogenates of these
cells. ACR (0.1 microM) inhibited the expression of iNOS protein and mRNA in
RASMCs without concomitant cytotoxic effects. ACR (>0.5 microM)-induced
inhibition of NO production in RAW cells was associated with substantial
cytotoxic effects as shown by measurement of lactate dehydrogenase release. These
results suggest that ACR is a potent inhibitor of iNOS induction in vascular
smooth muscle, but inhibits iNOS induction in macrophage only at high cytotoxic
PMID- 10677590
TI - Differential expression of renal adenosine A(1) receptors induced by acute renal
failure.
AB - The distribution of renal adenosine A(1) receptors was investigated in rats with
glycerol- or mercuric chloride (HgCl(2))-induced acute renal failure. Receptors
were localised by autoradiography using [(3)H]8-cyclopentyl-1,3-dipropylxanthine
([(3)H]DPCPX), a selective A(1) adenosine receptor antagonist. In saline-injected
control animals, significant labelling with [(3)H]DPCPX was detected in
glomeruli, the inner stripe of outer medulla, and the inner medulla. Sixteen
hours following induction of glycerol-induced acute renal failure (ARF), a 34%
increase in labelling in glomeruli was noted compared to saline-injected
controls, and by 48 hr, glomerular labelling had increased by 200%. In addition,
48 hr following glycerol injection, significant labelling was now detected in the
cortical labyrinth and medullary rays whilst, in the inner medulla, labelling had
decreased by 34%. By contrast to glycerol-induced ARF, the only significant
change noted 48 hr following induction of HgCl(2)-induced ARF was a 39% decrease
in labelling in the inner medulla. It is concluded that glycerol-induced ARF
results in differential expression of renal adenosine A(1) receptors with
increased expression in the cortex and reduced expression in the inner medulla.
Increased density of A(1) receptors in glomeruli may account, at least in part,
for the increased renal vasoconstrictor response to adenosine and depressed
glomerular filtration rate noted previously in this type of acute renal failure.
PMID- 10677591
TI - Involvement of hippocampal PKCbetaI isoform in the early phase of memory
formation of an inhibitory avoidance learning.
AB - Several evidences demonstrate that protein kinase C (PKC) is involved in
hippocampal long-term potentiation (LTP) and in different forms of learning,
including inhibitory avoidance training in rats. Here, we evaluated the levels of
conventional PKC isozymes (alpha, betaI, betaII, gamma) in synaptic plasma
membrane (SPM) fractions isolated from hippocampus of rats subjected to a one
trial inhibitory avoidance paradigm. At 0, 30 and 120 min after training, there
was a significant increase in the total amount of PKCbetaI. Densitometric
analysis of the immunoblots showed an increase of 142+/-11% at 0 min, 193+/-16%
at 30 min and 156+/-6% at 120 min after training relative to shocked control
values. No changes were found in PKCbetaI levels in SPM fractions of the shocked
animals relative to naive control values. No training-specific increments in the
levels of PKCalpha, betaII and gamma were observed at any time point tested.
However, an increase in PKCgamma levels was found in trained and shocked animals
sacrificed 120 min after each experimental procedure. In addition, bilateral
microinjections of a fairly selective inhibitor of PKCbetaI isozyme into the CA1
of the dorsal hippocampus produced amnesia when given 10 min before training, or
50, 110, but not 170 min, after training. Thus, the present findings demonstrate
the participation of PKCbetaI in the early synaptic events responsible for the
acquisition and consolidation of an inhibitory avoidance learning, and suggest a
putative role of this presynaptic isozyme on the enhanced PKC-dependent B-50/GAP
43 phosphorylation previously detected by us during this associative learning.
PMID- 10677592
TI - The influence of endogenous dopamine levels on the density of [3H]SCH23390
binding sites in the brain of the honey bee, Apis mellifera L.
AB - This paper examines the relationship between endogenous dopamine (DA) levels and
the density of [3H]SCH23390-binding sites in the brain of the adult worker honey
bee. DA levels were reduced pharmacologically using a single 10 microl injection
of either alpha-methyl-DL-p-tyrosine (AMT; 250 microg or 500 microg) or alpha
methyl-DL-tryptophan (AMTP; 250 or 500 microg) into the haemolymph of the bee. In
all cases, maximum depletion of DA was observed 3 h after treatment, but in bees
treated with AMTP (250 or 500 microg) or with 250 microg AMT, DA levels returned
to normal within 24 h of treatment. Neither AMT nor AMTP was selective for DA:
both drugs also reduced serotonin (5-hydroxytryptamine, 5HT) levels in the brain.
However, AMTP was more effective than AMT at depleting 5HT, whereas for DA, the
reverse was true. Depletion of DA levels, using 250 microg AMT, led to a dramatic
decline in the levels of specific binding of [3H]SCH23390, defined in this study
as binding in the presence of 5x10(-6) M cis-(Z)-flupentixol (see Ref. [28] ). In
contrast, naturally occurring diel fluctuations in DA levels, identified in the
optic lobes of the brain, and changes in brain DA levels resulting from
queenlessness, had no significant effect on the density of [3H]SCH23390-binding
sites in the brain of the bee. Overall, these results indicate that under normal
physiological conditions, there is no direct link in honey bees between changes
in endogenous brain DA levels and the density of D(1)-like receptors labelled by
[3H]SCH23390.
PMID- 10677593
TI - Are neocortical gamma waves related to consciousness?
AB - Previous research has shown that neocortical gamma waves (approximately 30-80 Hz)
are continuously present during low voltage fast neocortical activity (LVFA)
occurring during waking or active sleep. Gamma waves occur in a burst-suppression
pattern in association with large amplitude slow waves during quiet sleep or
anesthesia. The present experiments show that continuous gamma activity is also
present in rats during LVFA occurring during surgical anesthesia (with ether,
isoflurane or urethane) and that a burst-suppression pattern of gamma activity
occurs during large amplitude slow waves occurring in the waking state either
spontaneously in undrugged rats or as a result of treatment with
parachlorophenylalanine and scopolamine. The amplitude of gamma activity
occurring during anesthesia is variable but is often greater than it is in the
normal waking state. It is concluded that the pattern of neocortical gamma wave
activity is strongly related to the presence or absence of large amplitude slow
waves but is quite independent of the state of behavioral arousal. Whether or not
gamma wave activity is related to subjective awareness is a very difficult
question which cannot be answered with certainty at the present time.
PMID- 10677594
TI - N-type calcium channel blockers - tools for modulation of cerebral functional
units?
AB - According to in vitro and in vivo studies, the direct application of N-type
calcium channel blockers as for instance omega-conotoxin GVIA (omega-ctx)
potently inhibits the release of neurotransmitters like dopamine. To find out
whether this effect could be used for modulation of neurological functions, omega
ctx was used for continuous infusion into the functionally well characterized rat
striatum. Over the 2-week time course of intrastriatal application, rats
developed a decrease in spontaneous motor activity, spontaneous rotational
asymmetry towards the side of application, and behavioral supersensitivity to
apomorphine. After the end of infusion period, all functional deficits showed
reversibility. The pattern of spontaneous neurological deficits - in particular
supersensitivity to apomorphine - points to a substantial unilateral alteration
of dopaminergic transmission due to omega-ctx, which is suggested also by an
increase in dopamine receptor protein expression within the ipsilateral striatum.
Time course and reversibility of neurological deficits caused by omega-ctx, as
well as a lack of dopamine depletion contrast findings after selective
destruction of dopaminergic neurons and support a functional modulation of
dopaminergic transmission. The present study suggests that omega-ctx is an
effective potent tool for the unilateral and reversible intracerebral modulation
of neuronal circuits. Intracerebral application of omega-ctx could possibly open
the way to therapeutic interventions.
PMID- 10677595
TI - Cytochrome P-450 activities in human and rat brain microsomes.
AB - The role of cytochrome P450 in the metabolism of dextromethorphan, amitriptyline,
midazolam, S-mephenytoin, citalopram, fluoxetine and sertraline was investigated
in rat and human brain microsomes. Depending on the parameters, the limit of
quantification using gas chromatography-mass spectrometry methods was between 1.6
and 20 pmol per incubation, which generally contained 1500 microg protein.
Amitriptyline was shown to be demethylated to nortriptyline by both rat and human
microsomes. Inhibition studies using ketoconazole, furafylline, sulfaphenazole,
omeprazole and quinidine suggested that CYP3A4 is the isoform responsible for
this reaction whereas CYP1A2, CYP2C9, CYP2C19 and CYP2D6 do not seem to be
involved. This result was confirmed by using a monoclonal antibody against
CYP3A4. Dextromethorphan was metabolized to dextrorphan in rat brain microsomes
and was inhibited by quinidine and by a polyclonal antibody against CYP2D6. Only
the addition of exogenous reductase allowed the measurement of this activity in
human brain microsomes. Metabolites of the other substrates could not be
detected, possibly due to an insufficiently sensitive method. It is concluded
that cytochrome P450 activity in the brain is very low, but that psychotropic
drugs could undergo a local cerebral metabolism which could have pharmacological
and/or toxicological consequences.
PMID- 10677596
TI - Possible involvement of cytosolic phospholipase A(2) in cell death induced by 1
methyl-4-phenylpyridinium ion, a dopaminergic neurotoxin, in GH3 cells.
AB - Previously we reported that 1-methyl-4-phenylpyridinium ion (MPP(+)), a
dopaminergic neurotoxin, induced apoptosis of GH3 cells established from rat
anterior pituitary. In the present study, the role of MPP(+) along with that of
other apoptotic factors such as Ca(2+) and H(2)O(2) in cell death was examined.
Ionomycin induced DNA fragmentation and lactate dehydrogenase (LDH) leakage in
GH3 cells. H(2)O(2) also induced LDH leakage. Co-addition of MPP(+), in
conditions where MPP(+) had no effect by itself, enhanced ionomycin- and H(2)O(2)
induced cell death. Because the stimulation of phospholipase A(2) (PLA(2))
causing arachidonic acid (AA) release has been proposed to be involved in
neuronal cell death, the effect of MPP(+) on AA release in GH3 cells was
investigated. MPP(+) treatment for 8 h enhanced ionomycin- and H(2)O(2)
stimulated AA release mediated by activation of cytosolic PLA(2) in a
concentration-dependent manner, although MPP(+) by itself had no effect on AA
release. An inhibitor of cytosolic PLA(2) inhibited MPP(+)-induced cell death.
These findings suggest a synergistic effect of MPP(+) on Ca(2+)- and H(2)O(2)
induced cell death, and the involvement of cytosolic PLA(2) activation in MPP(+)
induced cell death in GH3 cells. Pretreatment with a caspase inhibitor or EGF did
not modify the ionomycin- or H(2)O(2)-induced AA release, or enhancement by
MPP(+), but the pretreatment inhibited the cell death in the presence and absence
of MPP(+). The involvement of caspase(s) on activation of PLA(2) by MPP(+) was
excluded, and EGF inhibited MPP(+)-induced cell death downstream of the AA
release.
PMID- 10677597
TI - Development of kindling and spontaneous seizures after massed stimulation of
different loci in the rat piriform cortex.
AB - Massed electrical stimulation of the anterior piriform cortex (PC) in rats using
short (5 min) interstimulus intervals has previously been reported to induce
severe chronic epilepsy with spontaneous seizures and has thus proposed to
represent a novel model of temporal lobe epilepsy. In the present study, we used
this stimulation protocol to evaluate the frequency and severity of recurrent
spontaneous seizures produced in this way. In addition to the locus in the
anterior PC previously used for massed stimulation (MS), we also stimulated rats
via a locus in the transition zone between anterior and posterior PC ("central
PC"), which previously was found to be more sensitive to electrical stimulation
than various other loci in the anterior or posterior PC. During MS (71
stimulations for 1 s each at twice afterdischarge threshold), focal and
infrequent secondary generalized seizures occurred in both groups, but there was
no consistent progressive increase in seizure severity with increasing number of
seizures, possibly as a result of postictal inhibitory processes. Following MS,
rats were restimulated after 1, 2, 4, and 7 weeks, using five stimuli at 5-min
interstimulus periods at each retest period. In both PC-implanted groups, seizure
severity and seizure duration progressively increased over the period of the
retests, indicating a delayed development of kindling. Spontaneous seizures were
only observed rarely, so that MS of the PC is certainly no effective means of
producing recurrent spontaneous seizures.
PMID- 10677598
TI - The involvement of dopamine in nociception: the role of D(1) and D(2) receptors
in the dorsolateral striatum.
AB - Determination of the neuroanatomical and neurochemical factors that contribute to
nociception is an essential element in the study and treatment of pain. Several
lines of evidence have implicated nuclei and neurotransmitters within the basal
ganglia in nociception. For example, previous studies have shown that dopamine
receptors in the striatum are involved in acute nociception, however, it remains
to be determined if dopamine receptors in the dorsolateral striatum are involved
in persistent nociception. The purpose of the present study was therefore to
determine whether activation or antagonism of dopamine receptors in the
dorsolateral striatum influences the nociceptive responses of rats in the
formalin test, a model of persistent pain. It was found that micro-injection of
the non-selective dopamine antagonist haloperidol into the dorsolateral striatum
increases formalin-induced nociception whereas injection of the non-selective
dopamine agonist apomorphine reduces formalin-induced nociception. Injection of
the D(1) antagonist SCH23390 or the D(1) agonist SKF38393 does not affect
formalin-induced nociception. In contrast, injection of the D(2) antagonist
eticlopride enhances formalin-induced nociception, whereas injection of the D(2)
agonist quinpirole reduces formalin-induced nociception. These results provide
additional evidence that dopamine receptors in the striatum are involved in
nociception. Furthermore, this study strongly suggests that D(2), but not D(1),
dopamine receptors in the dorsolateral striatum are involved in modulation of
persistent nociception.
PMID- 10677599
TI - N-Ethylmaleimide modulation of tetrodotoxin-sensitive and tetrodotoxin-resistant
sodium channels in rat dorsal root ganglion neurons.
AB - The effects of N-ethylmaleimide (NEM), an alkylating reagent to protein
sulfhydryl groups, on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant
(TTX-R) sodium channels in rat dorsal root ganglion (DRG) neurons were studied
using the whole cell configuration of patch-clamp technique. When currents were
evoked by step depolarizations to 0 mV from a holding potential of -80 mV NEM
decreased the amplitude of TTX-S sodium current, but exerted little or no effect
on that of TTX-R sodium current. The inhibitory effect of NEM on TTX-S sodium
channel was mainly due to the shift of the steady-state inactivation curve in the
hyperpolarizing direction. NEM did not affect the voltage-dependence of the
activation of TTX-S sodium channel. The steady-state inactivation curve for TTX-R
sodium channel was shifted by NEM in the hyperpolarizing direction as that for
TTX-S sodium channel. NEM caused a change in the voltage-dependence of the
activation of TTX-R sodium channel unlike TTX-S sodium channel. After NEM
treatment, the amplitudes of TTX-R sodium currents at test voltages below -10 mV
were increased, but those at more positive voltages were not affected. This was
explained by the shift in the conductance-voltage curve for TTX-R sodium channels
in the hyperpolarizing direction after NEM treatment.
PMID- 10677600
TI - Participation of Rel/NF-kappaB transcription factors in long-term memory in the
crab Chasmagnathus.
AB - The induction of gene expression has been correlated with long-lasting neuronal
plasticity and long-term memory (LTM) formation. The fast activation of
constitutive transcription factors by signaling mechanisms is thought to be the
link between synaptic events and gene expression. However, only one constitutive
transcription factor, CREB, has been shown to play a key role in several memory
paradigms, both in vertebrates and invertebrates. Here, we report evidences for
Rel/NFkappa-B constitutive transcription factors participation in memory. Using
the LTM paradigm in the crab Chasmagnathus, an enhancement of NFkappa-B DNA
binding activity was found after spaced training, which induces LTM, but not
after massed training which yields an intermediate-term memory (ITM). Such
finding is correlated with the requirement of protein synthesis for LTM
consolidation but not for ITM. Furthermore, NFkappa-B activation was observed
after 15 or 30 training trials, which are sufficient to induce LTM, but not after
5 or 10 trials, a number of trials insufficient to induce LTM. The kinetics of
activation was studied and two waves of DNA-binding activity were found, similar
to the time course described in other systems. NFkappa-B activation after
training was also found in synaptosomal extracts. The latter result supports the
hypothesis of a novel synapse-to-nucleus signaling system, in which the
transcription factor is locally activated by synaptic events and then transported
to the nucleus.
PMID- 10677601
TI - Effects of nitric oxide gas on cat carotid body chemosensory response to hypoxia.
AB - It has been proposed that nitric oxide (NO) is an inhibitory modulator of carotid
body (CB) chemoreception to hypoxia. However, the effects of NO gas on carotid
chemoreception have not been tested yet. The role played by NO has been revealed
by the use of pharmacological tools (i.e., NO donors and NO synthase inhibitors).
Here, we studied the effects of NO gas (25 ppm in N(2)) on the chemosensory
response to hypoxia (PO(2) approximately 30 Torr) in the cat CB perfused in
vitro. During steady hypoxic chemoreceptor excitation, bolus injections or
perfusion of Tyrode equilibrated with NO reduced the increased frequency of
carotid chemosensory discharges (f(x)). Perfusion for 2 min of Tyrode
equilibrated with NO also reduced the rate of the rise of the chemosensory
response, as well as the maximal amplitude, as compared with the normal
chemosensory response to hypoxia. Present results provide direct evidence that NO
gas is an inhibitory modulator of CB hypoxic chemoreception.
PMID- 10677602
TI - Immunohistochemical detection of heme oxygenase-2 in the periodontal Ruffini
ending of the rat incisor.
AB - The present study was carried out to examine the occurrence of heme oxygenase-2
(HO-2) in the periodontal ligament of the rat incisor. HO-2-like immunoreactive (
IR) structures showed dendritic profiles, resembling the Ruffini endings, in the
alveolar half of the ligament of rat incisor. Neither thin nerve fibers nor
perivascular nerve fibers displayed HO-2-like immunoreactivity (-LI). No non
neural elements exhibited HO-2-LI. Electron microscopy revealed that
immunoreactions were diffusely observed in the axon terminals of the Ruffini
endings, but neither terminal Schwann cells nor Schwann sheaths contained
immunoreactions for HO-2. Both most neurons in the trigeminal ganglion and
trigeminal mesencephalic nucleus showed HO-2-LI. The presence of HO-2 in the
periodontal Ruffini endings and its absence in the periodontal thin nerve fibers
suggest the involvement of carbon monoxide produced by HO-2 in mechanoreception
in the periodontal ligament.
PMID- 10677603
TI - Inhibition of L-homocysteic acid and buthionine sulphoximine-mediated
neurotoxicity in rat embryonic neuronal cultures with alpha-lipoic acid
enantiomers.
AB - In the present report, we have set out to investigate the potential capacity of
both the oxidised and reduced forms of RS-alpha-lipoic acid, and its separate R
(+) and S-(-)enantiomers, to prevent cell death induced with L-homocysteic acid
(L-HCA) and buthionine sulphoximine (BSO) in rat primary cortical and hippocampal
neurons. L-HCA induced a concentration-dependent neurotoxic effect, estimated by
cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT)
reduction, in primary neurons, but was significantly more toxic for hippocampal
(EC(50)=197 microM) compared with cortical neurons (EC(50)=1016 microM) whereas D
HCA demonstrated only moderate (<20%) toxicity. On the other hand, cortical and
hippocampal cultures were equally susceptible (341 and 326 microM, respectively)
to the neurotoxic action of BSO. Antioxidants including butylated hydroxyanisole,
propyl gallate and vitamin E protected cells against the neurotoxic effect of L
HCA and BSO. However, N-acetyl-cysteine and tert-butylphenyl nitrone, although
capable of abrogating L-HCA-mediated cell death showed no protective effect
against BSO-mediated toxicity. RS-alpha-lipoic acid, RS-alpha-dihydrolipoic acid
and the enantiomers R-alpha-lipoic acid and S-alpha-lipoic acid protected cells
against L-HCA-mediated toxicity with EC(50) values between 3.1-8.3 microM in
primary hippocampal neurons and 2.6-16.8 microM for cortical neurons. However, RS
alpha-lipoic acid, RS-alpha-dihydrolipoic acid, and S-alpha-lipoic acid failed to
protect cells against the degeneration induced by prolonged exposure to BSO,
whereas the natural form, R-alpha-lipoic, was partially active under the same
conditions. The present results indicate a unique sensitivity of hippocampal
neurons to the effect of L-HCA-mediated toxicity, and suggest that RS-alpha
lipoic acid, and in particular the R-alpha-enantiomeric form is capable of
preventing oxidative stress-mediated neuronal cell death in primary cell culture.
PMID- 10677604
TI - The effects of N-methyl-N-nitrosourea and azoxymethane on focal cerebral
infarction and the expression of p53, p21 proteins.
AB - If the activity of pro-apoptotic genes can be down-regulated by certain
chemicals, cells may be protected from apoptosis. To test this hypothesis in a
cerebral infarction model, we used N-methyl-N-nitrosourea (MNU) and azoxymethane
(AOM), which were approved gene-modulating chemicals. A focal cerebral infarction
was created by coagulation of the right middle cerebral artery and ipsilateral
common carotid artery (CCA) and simultaneous transient occlusion of the
contralateral CCA for 30 min in 25 adult Sprague-Dawley rats that were sacrificed
24 h later. In one group (n=7), MNU (5 mg/kg) was injected intravenously 30 min
before initiation of ischemia. In another group (n=7), AOM (15 mg/kg) was
administered intraperitoneally before 24 h of ischemia. The infarction volumes
were checked and the brains were stained for p53 and p21 proteins. The width in
micrometers of the peri-infarct area containing p53 or p21 protein-positive
cells, and the number of p53 or p21 protein-positive cells (cells/HPF) were
measured at an adjacent peri-infarct area. The AOM-treated group showed a
significantly reduced infarction volume (by 42.5%, p<0.001), a significantly
greater number of p53 positive cells (by 12.0%, p<0. 05), and a significantly
wider p53 protein-positive area (by 15.6%, p<0.01) than the untreated group. AOM
did not show any influence on the expression pattern of the p21 protein. MNU had
no effect in the expression of p53 or p21 proteins. As a result, we concluded
that AOM revealed a protective effect in ischemia by suppressing the pro
apoptotic activity of the p53 gene. Safer chemicals that can modulate apoptotic
genes, if any, will provide a new therapeutic modality for cerebral infarction.
PMID- 10677605
TI - N-methyl-D-aspartate-type glutamate receptors are found in post-synaptic targets
of adrenergic terminals in the thoracic spinal cord.
AB - Adrenergic (C1) neurons in the rostral ventrolateral medulla (RVL) are
sympathoexcitatory and project directly to sympathetic preganglionic neurons
(SPNs) in the thoracic spinal cord. C1 neurons also contain glutamate which may
mediate the excitatory effects of RVL stimulation on SPNs through the N-methyl-D
aspartate (NMDA)-type receptor. Dual-labeling immunocytochemistry, combined with
electron microscopy, was used to determine if NMDA receptors are located post
synaptic to adrenergic terminals in the spinal cord. Adrenergic terminals were
labeled using an antibody directed against phenylethanolamine-N-methyl
transferase (PNMT) and the NMDA receptor was identified using an antibody
directed against the R1 subunit of the receptor (NMDAR1). NMDAR1 was found
primarily in large and small dendrites and a few perikarya. The presence of
NMDAR1 in the dendritic targets of PNMT-containing terminals was quantified in
spinal cords sectioned either horizontally or coronally. PNMT-labeled terminals
formed asymmetric synapses on dendrites containing immunogold labeling for
NMDAR1, but NMDAR1 was more often detected in the targets of PNMT terminals when
spinal cords were sectioned horizontally (59%) rather than coronally (28%). This
difference in prevalence of NMDAR1 in targets of PNMT terminals is likely due to
the preferential orientation of SPN dendrites in the horizontal plane, since
longer dendritic shafts were visible in horizontal sections. When NMDAR1 was
present in the dendritic targets of many adrenergic terminals, it was usually
located at sites distal to the adrenergic input. We conclude that NMDA receptor
ligands are likely to modulate the activity of dendritic targets of adrenergic
terminals in the spinal cord, but are not closely associated with adrenergic
synaptic input.
PMID- 10677606
TI - C-terminal phosphorylation of the high molecular weight neurofilament subunit
correlates with decreased neurofilament axonal transport velocity.
AB - We probed the relationship of NF axonal transport of neurofilaments (NFs) to
their phosphorylation state by comparing these parameters in two closely-aged
groups of young adult mice - 2 and 5 months of age. This particular time interval
was selected since prior studies demonstrate that optic axons have already
completed axonal caliber expansion and attained adult NF levels by 2 months but,
as shown herein, continue to increase NF-H C-terminal phosphorylation. NF axonal
transport was monitored by autoradiographic analysis of the distribution of
radiolabeled subunits immunoprecipitated from optic axon segments at intervals
following intravitreal injection of 35S-methionine. Both the peak and front of
radiolabeled NFs translocated faster in 2- vs. 5-month-old mice. This
developmental decline in NF transport rate was not due to reduced incorporation
of NFs into the cytoskeleton, nor to an overall decline in slow axonal transport.
By excluding or minimizing other factors, these findings support previous
conclusions that C-terminal NF phosphorylation regulates NF axonal transport.
PMID- 10677607
TI - Elevated substance-P-like immunoreactivity levels in spinal dialysates during the
formalin test in normal and diabetic rats.
AB - Pharmacologic studies implicate the involvement of substance P in spinal
nociceptive processing during the formalin test. However, no direct measurement
of the temporal changes in substance P levels within the spinal cord of conscious
animals has been reported. Further, dissociation between substance P levels and
formalin-evoked nocifensive behavior may exist in diabetic rats, as exaggerated
hyperalgesic behavior coexists with reduced peripheral nerve substance P levels.
The present study was performed to directly measure the appearance of substance-P
like immunoreactivity (SP-LI) in spinal CSF of conscious, unrestrained rats using
microdialysis techniques following injection of formalin into the hindpaw. The
effect of diabetes upon formalin-evoked SP-LI levels in spinal CSF dialysates was
also determined. In control rats, SP-LI increased in spinal dialysates following
formalin injection and levels were maximal 20-30 min after injection, rising to
325% of basal values (p<0.02). Diabetic rats exhibited reduced (p<0.05) SP-LI in
their spinal roots, while basal levels in spinal CSF were not different from
controls. Formalin-evoked nocifensive behavior was increased in diabetic rats but
SP-LI levels in spinal CSF dialysates after paw formalin injection were
significantly (p<0.05) attenuated, reaching a maximum of only 161% of basal
levels. This was accompanied by attenuated swelling at the formalin injection
site and increased thermal response latencies. While increased SP-LI in spinal
CSF coincides with phase 2 behavior in the formalin test and may contribute to
spinal nociceptive processing during this period, exaggerated spinal substance P
release is unlikely to underlie the increased nocifensive behavior seen in
diabetic rats.
PMID- 10677608
TI - Reduced glutathione oxidation ratio and 8 ohdG accumulation by mild ischemic
pretreatment.
AB - A critical role of oxidative stress has been implicated in ischemic brain damage.
Mild ischemic pretreatment and/or synthesis of heat shock proteins (HSPs) has
been suggested to protect against oxidative brain damage. However, experimental
support of this suggestion have proven to be difficult partly because sensitive
indices to assess oxidative consequences of ischemic brain damage were few. In
this study, we have attempted to establish biochemical assay systems to
quantitate oxidative brain damage following ischemia. We produced experimental
brain ischemia in the Mongolian gerbil (Meriones unguiculatus) and examined the
hippocampus for ischemic brain damage. The results obtained from ischemic gerbil
hippocampus demonstrated that oxidative brain damage can be quantitated by
determining glutathione oxidation ratio together with the accumulation of the
oxidative DNA damage product, 8-hydroxy-2'-deoxyguanosine (8 ohdG). Our results
also demonstrated a role for mild ischemic pretreatment and synthesis of HSPs
against oxidative brain damage. We showed that mild 2-min ischemic pretreatment
reduced the degree of both glutathione oxidation ratio and 8 ohdG accumulation in
gerbil hippocampus subsequent to 10 min ischemic challenge. We also showed that
the accumulation of HSP70 was closely associated with the reduction of oxidative
brain damage. To our knowledge, this is the first report to investigate
glutathione redox states and oxidative DNA damage levels to evaluate a protective
role of mild ischemic pretreatment and HSP synthesis following brain ischemia.
Our data validate the previous suggestions and provide new additional data that
argue for the protective role of mild ischemic pretreatment and HSP70 synthesis
against oxidative brain damage.
PMID- 10677609
TI - Localization of hindbrain glucoreceptive sites controlling food intake and blood
glucose.
AB - Feeding and blood glucose responses to local injection of nanoliter volumes of 5
thio-D-glucose (5TG), a potent antimetabolic glucose analogue, were studied at
142 hindbrain and 61 hypothalamic cannula sites. A site was considered positive
if 5TG elicited at least 1.5 g more food intake or a hyperglycemic response at
least 25 mg/dl greater than the respective responses elicited by vehicle
injection in the same rat. Of 61 hypothalamic cannula sites tested, none were
positive for blood glucose and only one was positive for feeding. Increasing the
5TG dose to 48 ug did not produce additional positive results at hypothalamic
sites. In contrast, 66 hindbrain sites were positive for feeding and 49 were
positive for blood glucose, with 33 of these being positive for both responses.
The distribution of positive sites for feeding and hyperglycemia overlapped
almost completely. Positive sites were concentrated in two distinct zones: one in
the ventrolateral and one in the dorsomedial medulla. In both locations, the
glucoreceptive areas extended approximately from the level of the area postrema
(AP) to the pontomedullary junction. Glucoreceptive zones were co-distributed
with epinephrine cell groups C1-C3, suggesting that epinephrine neurons may be
important components of the neural circuitry for glucoregulation. Localization of
glucoreceptive sites will facilitate positive identification of glucoreceptor
cells and the direct analysis of the neural mechanisms through which they
influence food intake and metabolic responses.
PMID- 10677610
TI - Effects of a novel neurotensin peptide analog given extracranially on CNS
behaviors mediated by apomorphine and haloperidol.
AB - Neurotensin (NT) is a neuropeptide neurotransmitter in the central nervous
system. It has been implicated in the therapeutic and in the adverse effects of
neuroleptics. Activity of NT in brain can only be shown by direct injection of
the peptide into that organ. However, we have developed a novel analog of NT(8
13), NT69L, which is active upon intraperitoneal (i.p.) injection. Like atypical
neuroleptics, NT69L blocked the climbing behavior in rats, but not the licking
and sniffing behaviors of a high dose (600 microgram/kg) of the non-selective
dopamine agonist apomorphine. Its blockade of climbing was very potent with an
ED(50) (effective dose at 50% of maximum) of 16 microgram/kg. Both apomorphine
and NT69L caused a long-lasting hypothermia, which was greater with the peptide
but not synergistic in combination with apomorphine. The ED(50) of NT69L for
hypothermia was 390 microgram/kg. NT69L (up to 5 mg/kg i.p.) did not produce
catalepsy. However, when given before haloperidol, NT69L, but not clozapine,
completely prevented catalepsy. When given after haloperidol, NT69L, but not
clozapine, reversed haloperidol's cataleptic effects with an ED(50) of 260
microg/kg. There was no significant difference between the ED(50)s for
hypothermia and anticataleptic effects of NT69L. However, the ED(50) for blocking
the effects of apomorphine was significantly lower than the other two. These data
suggest that NT69L may have neuroleptic properties in humans and may be useful in
the treatment of extrapyramidal side effects caused by typical neuroleptics such
as haloperidol.
PMID- 10677611
TI - Colocalization of arginine-vasotocin and chicken luteinizing hormone-releasing
hormone-I (cLHRH-I) in the preoptic-hypothalamic region of the chicken.
AB - To characterize a possible relationship between chicken luteinizing hormone
releasing hormone-I (cLHRH-I) and arginine-vasotocin (AVT) we performed
immunocytochemical double-stainings throughout the preoptic-hypothalamic region
of the chicken brain. This study clearly reveals a partial colocalization between
both neuropeptides. Single-labeled neurons, containing either cLHRH-I or AVT are
found intermingled with double stained cells, immunoreactive (ir) for both
peptides. A significant number of double-labeled perikarya is found in the
preoptic area, more specifically in the ventral and external portion of the
supraoptic nucleus (SOv and SOe) and in the medial preoptic nucleus (MPOv). At
the level of the anterior hypothalamus, double-labeled cells are predominantly
observed near the third ventricle in the nucleus paraventricularis
magnocellularis (PVN) and the nucleus periventricularis hypothalami (PHN). Next
to this colocalization, a number of cLHRH-I-ir cell bodies are found in close
apposition to AVT-ir fiber profiles in the very same areas. Taken together, these
data are the first to provide morphological evidence indicating that the AVT
system might be involved in the regulation of cLHRH-I release and thus of
reproductive functions in birds.
PMID- 10677612
TI - Selective responsiveness of medial prefrontal cortex neurons to the meaningful
stimulus with a low probability of occurrence in rats.
AB - Multi-unit neuronal activity was recorded in the medial prefrontal cortex (mPFC)
of 13 chronically prepared male rats while they performed a two-tone
discrimination task. Tones at 1000 and 2000 Hz were sequentially presented at
intervals of 3-6 s. The duration of each tone was 0.8 s. Rats were trained to
press a bar within 1.2 s after the cessation of the 1000 Hz tone (target), and
not to press the bar when the other tone (non-target) was presented. Intracranial
electrical stimulation (ICS) of the medial forebrain bundle was given as a reward
immediately after the rats had correctly responded to the target tone.
Probability of the target occurrence was either 30% or 70% in different sessions.
When the target tone was presented on only 30% of the trials, the mPFC neurons in
the majority of rats tested (10/13) exhibited phasic excitation about 100 ms
after the onset of the target tone. However, when the target tone occurred on 70%
of the trials, mPFC neurons in most of rats (11/13) did not show excitatory
responses, and in some of them (5/13) were inhibited. No mPFC neurons exhibited
significant responses to the non-target tone, regardless of its probability.
These results suggest that the mPFC neurons selectively respond to meaningful
events with a low probability of occurrence.
PMID- 10677613
TI - Cloning, sequencing, chromosomal location, and function of cDNAs encoding an
opioid growth factor receptor (OGFr) in humans.
AB - The native opioid growth factor (OGF), [Met(5)]-enkephalin, is a tonic inhibitory
peptide that modulates cell proliferation and tissue organization during
development, cancer, cellular renewal, wound healing, and angiogenesis. OGF
action is mediated by a receptor mechanism. We have cloned and sequenced cDNAs
encoding multiple spliced forms of a human OGF receptor. The open reading frame
in the longest cDNA was found to encode a protein of 697 amino acids, and 8
imperfect repeats of 20 amino acids each were a prominent feature. Altogether,
five alternatively spliced forms were observed. The cDNA hybridized to mRNA from
a variety of normal and neoplastic cells and tissues. Functional studies using
antisense oligonucleotides to OGFr demonstrated an enhancement in cell growth.
Fluorescent in situ hybridization (FISH) experiments showed the chromosomal
location to be 20q13.3. This OGF receptor has no homology to classical opioid
receptors. These results provide molecular validity for the interaction of OGF
and OGF receptor in the regulation of growth processes in humans.
PMID- 10677614
TI - The distribution of neuronal nitric oxide synthase in the nucleus tractus
solitarii of the squirrel monkey.
AB - The distribution of neuronal nitric oxide synthase (nNOS) containing neurons and
fibers in subnuclei of the nucleus tractus solitarii (NTS) in the squirrel
monkey, Saimuri sciureus, was investigated by nNOS immunohistochemistry and
nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry.
Generally, the staining pattern of nNOS and NADPH-diaphorase in the NTS was
similar. A high density of neurons and fibers exhibiting both nNOS
immunoreactivity and NADPH-diaphorase reactivity was present in the central,
medial, intermediate, and dorsolateral subnuclei of the NTS. A moderate density
of neurons and fibers that stained for both nNOS and NADPH-diaphorase was noted
in the interstitial and ventromedial subnuclei. The gelatinosus and commissural
subnuclei contained a low density of neurons and fibers exhibiting nNOS
immunoreactivity and NADPH-diaphorase staining. The dorsal motor nucleus of vagus
contained a high density of nNOS immunopositive and NADPH-diaphorase containing
neurons and fibers at the rostral level, but contained a moderate density of
positive fibers and very few positive neurons at the intermediate, subpostremal
and commissural NTS levels. Incongruence was noted, however, between nNOS
immunostaining and NADPH-diaphorase staining in blood vessels in the brainstem.
Capillaries and small vessels exhibited strong staining for NADPH-diaphorase but
no nNOS immunoreactivity. In summary, this work substantiates the presence of
nNOS in subnuclei of the monkey NTS and is consistent with a role for NO(.) in
neurotransmission in primate NTS.
PMID- 10677615
TI - Early and sequential recruitment of apoptotic effectors after focal permanent
ischemia in mice.
AB - In experimental models of cerebral ischemia, cells within the damaged territory
die by necrosis and by apoptosis that contributes to the expansion of the insult.
Apoptotic machinery mobilizes intracellular processes such as induction of Bcl-2
family members, activation of the proteolytic cascade including the caspases, and
cleavage of caspase substrates, such as poly(ADP-ribose) polymerase or PARP.
Mitochondria play a pivotal role in controlling apoptosis by releasing cytochrome
c and modulating redox state, both under the regulation of manganese superoxide
dismutase (Mn SOD) via superoxide anion detoxification. The implication and the
kinetics of such events in apoptosis induced after focal permanent ischemia in
mice remains to be studied. In a paradigm of ischemic insult induced by occlusion
of the middle cerebral artery (MCAO) in mice, we showed by immunohistochemistry a
constitutive expression of caspase-3 that is enhanced after MCAO in neurons
localized within the infarcted zone. As a function of time intervals after MCAO,
the cytochrome c amount increased in the cytosolic fraction of ischemic cortical
extracts. The kinetics of the release was in concordance with the expression of
caspase-3 and the subsequent cleavage of PARP appearing before the
internucleosomal fragmentation of DNA, the ultimate step of apoptosis. When the
apoptotic markers progressively appeared, no changes of Mn SOD activity or Mn SOD
expression were detected after MCAO. We can therefore speculate that the
recruitment of Mn SOD did not participate per se in the release of cytochrome c
elicited after permanent focal ischemia.
PMID- 10677616
TI - Mechanical activation of dorsal root ganglion cells in vitro: comparison with
capsaicin and modulation by kappa-opioids.
AB - The aim of this study was to characterize plasma membrane pathways involved in
the intracellular calcium ([Ca(2+)](i)) response of small DRG neurons to
mechanical stimulation and the modulation of these pathways by kappa-opioids.
[Ca(2+)](i) responses were measured by fluorescence video microscopy of Fura-2
labeled lumbosacral DRG neurons obtained from adult rats in short-term primary
culture. Transient focal mechanical stimulation of the soma, or brief superfusion
with 300 nM capsaicin, resulted to [Ca(2+)](i) increases which were abolished in
Ca(2+)-free solution, but unaffected by lanthanum (25 microM) or tetrodotoxin
(10(-6) M). 156 out of 465 neurons tested (34%) showed mechanosensitivity while
55 out of 118 neurons (47%) were capsaicin-sensitive. Ninty percent of capsaicin
sensitive neurons were mechanosensitive. Gadolinium (Gd(3+); 250 microM) and
amiloride (100 microM) abolished the [Ca(2+)](i) transient in response to
mechanical stimulation, but had no effect on capsaicin-induced [Ca(2+)](i)
transients. The kappa-opioid agonists U50,488 and fedotozine showed a dose
dependent inhibition of mechanically stimulated [Ca(2+)](i) transients but had
little effect on capsaicin-induced [Ca(2+)](i) transients. The inhibitory effect
of U50,488 was abolished by the kappa-opioid antagonist nor-Binaltorphimine
dihydrochloride (nor-BNI; 100 nM), and by high concentrations of naloxone (30-100
nM), but not by low concentrations of naloxone (3 nM). We conclude that
mechanically induced [Ca(2+)](i) transients in small diameter DRG somas are
mediated by influx of Ca(2+) through a Gd(3+)- and amiloride-sensitive plasma
membrane pathway that is co-expressed with capsaicin-sensitive channels.
Mechanical-, but not capsaicin-mediated, Ca(2+) transients are sensitive to kappa
opioid agonists.
PMID- 10677617
TI - Methylmalonic and propionic acids increase the in vitro incorporation of 32P into
cytoskeletal proteins from cerebral cortex of young rats through NMDA glutamate
receptors.
AB - In this study we investigated the effects of methylmalonic acid (MMA) and
propionic acid (PA) on the phosphorylation of cytoskeletal proteins of cerebral
cortex of rats. Slices of tissue were incubated with 32P-orthophosphate in the
presence or absence of glutamate, MMA, PA and ionotropic or metabotropic
glutamate receptor agonists. The cytoskeletal fraction was isolated and the
radioactivity incorporated into the cytoskeletal proteins was measured. Results
demonstrated that the acids, glutamate and NMDA increased the phosphorylation of
the proteins studied. However, this effect was not observed for non-NMDA
ionotropic agonists or metabotropic agonists. Experiments using glutamate
receptor antagonists confirmed that MMA and PA at the same concentrations as
found in tissues from propionic or methylmalonic acidemic children increase the
phosphorylation of cytoskeletal proteins, possibly via NMDA glutamate receptors.
Therefore, it is feasible that these findings may be related to the neurological
dysfunction characteristic of these disorders.
PMID- 10677618
TI - Effects of gestational hypoxia on mRNA levels of Glut3 and Glut4 transporters,
hypoxia inducible factor-1 and thyroid hormone receptors in developing rat brain.
AB - Alterations of brain development result from noxious intrauterine signals, as
oxygen deprivation, which decrease glucose energetic yield. To verify the
hypothesis that a defect of brain energetic adaptation is responsible for these
alterations, we have studied the effects of gestational hypoxia (10% oxygen
during the last 2 weeks of fetal life) on cerebral ontogenesis of glucose
transporters which control the limiting step of glucose utilization by neurons.
This study is realised in rats by quantification of whole brain Glut3 and Glut4
mRNA in 14- and 19-day-old embryos (E14, E19), newborn (P0) and 7 postnatal-day
old rats (P7) by using reverse transcription-polymerase chain reaction (RT-PCR)
method. We have associated our study with the analysis of a transcriptional
factor, the hypoxia inducible factor-1alpha (HIF-1alpha), known to control the
expression of glucose transporter, and with a family of transcriptional factors,
the thyroid hormone receptors (TR), regulating specific genes involved in brain
development. The data show (1) for the first time the Glut4 and HIF-1alpha gene
expression in fetal rat brain which are detected as soon as E14, (2) that
gestational hypoxia induces an increase of mRNA transcript levels of Glut3,
Glut4, TRalpha2, TRbeta1 and HIF-1alpha genes mainly or exclusively at E14, and
(3) that the absence of response of Glut3 and HIF-1alpha at E19 in hypoxic vs.
normoxic group could indicate an insufficient energetic adaptation at this period
of development which could lead to the neural alterations observed postnatally.
PMID- 10677619
TI - LP-BM5 infection impairs spatial working memory in C57BL/6 mice in the Morris
water maze.
AB - Previous studies show that the LP-BM5 murine leukemia virus causes an acquired
immunodeficiency syndrome in C57BL/6 mice (MAIDS) and impairs learning and memory
without gross motor impairment. To assess spatial working memory impairment after
LP-BM5 infection and the time course of this impairment, we tested mice in a
modified working-memory version of the Morris water maze. Twenty mice were
inoculated with LP-BM5; controls received medium (Minimum Essential Medium). In
the test procedure, animals had two 1-min training sessions to learn the position
of a randomly placed hidden platform. Thirty seconds after the second training
session, animals were placed in the maze without the platform, and time and
pathlength spent in each quadrant of the maze were measured. For 9 weeks after LP
BM5 infection, both groups showed preference for the target quadrant compared to
the opposite quadrant. At 10 and 11 weeks after infection, the LP-BM5 virus
infected mice lost this target quadrant preference. We conclude that LP-BM5
infection impaired spatial working memory in a modified working-memory version of
the Morris water maze test in C57BL/6 mice at 10 and 11 weeks after virus
infection.
PMID- 10677620
TI - Sensory deafferentation and olfactory bulb morphology in the zebrafish and
related species.
AB - The zebrafish, Danio rerio, has become an important model species for examining
olfactory system structure and function, yet little is known about developmental
changes in olfactory bulb morphology from embryo to adult. The present study
examined both normal growth and the effects of deafferentation on the bulb from
hatching to adulthood. In young animals, the bulb is small relative to body size
and has a higher percentage of its volume occupied by incoming olfactory nerve
fibers. Young animals are also more affected by sensory deafferentation.
Olfactory rosette removal resulted in more than 50% reductions in laminar
volumes, indicating that sensory input is important during periods of rapid
development. In addition, three closely related species were examined to compare
how differing bulb morphology might influence the effects of bulb manipulation.
The cherry barb, Barbus (=Puntius) titteya, and giant danio, Danio aequipinnatus,
have larger bulbs and laminar volumes relative to body size than the zebrafish or
scissortail rasbora, Rasbora trilineata. Both are also more affected by
deafferentation, with at least a 35% reduction in laminar sizes in many of the
bulb layers. The studies are discussed in terms of the importance of the
olfactory system to each species and are also compared to the effects of sensory
manipulations in other animals.
PMID- 10677621
TI - Cells containing immunoreactive estrogen receptor-alpha in the human basal
forebrain.
AB - The distribution of estrogen receptor protein-alpha (ER-alpha)-containing cells
in the human hypothalamus and adjacent regions was studied using a monoclonal
antibody (H222) raised against ER-alpha derived from MCF-7 human breast cancer
cells. Reaction product was found in restricted populations of neurons and
astrocyte-like cells. Neurons immunoreactive for ER-alpha were diffusely
distributed within the basal forebrain and preoptic area, infundibular region,
central hypothalamus, basal ganglia and amygdala. Immunoreactive astrocyte-like
cells were noted within specific brain regions, including the lamina terminalis
and subependymal peri-third-ventricular region. These data are consistent with
the location of estrogen receptors in the basal forebrain of other species and
the known effects of estrogens on the cellular functions of both neurons and
supporting elements within the human hypothalamus and basal forebrain.
PMID- 10677622
TI - Organization of intratelencephalic projections to the visual Wulst of the chick.
AB - The avian visual Wulst, said to be the equivalent of the striate cortex in
mammals, is the telencephalic visual area of the thalamofugal visual pathway. In
this study, by means of retrograde labelling with fluorescent tracers injected
into the Wulst regions in the left and right hemispheres, we have investigated
the organization of the intratelencephalic projections to the visual Wulst in
chicks. After injecting Fluorogold (FG), True blue (TB) or rhodamine into the
visual Wulst, fluorescent-labelled neurones were found in the ipsilateral
neostriatum frontale, pars lateralis (NFl), the ipsilateral neostriatum
intermedium (NI) and the ipsilateral dorso-lateral neostriatum. Labelled neurones
were also found in both the ipsilateral and contralateral archistriata. In
addition, some neurones in the archistriatum were double-labelled, which
indicates that these archistriatal neurones have axon collaterals projecting to
the visual Wulst on both sides of the forebrain. Through these intratelencephalic
afferents to the visual Wulst, visual information transmitted in the thalamofugal
pathway may be modulated by other telencephalic areas. The possible roles of
these connections in regulating behaviour are discussed.
PMID- 10677623
TI - Conformation of paired helical filaments blocks dephosphorylation of epitopes
shared with fetal tau except Ser199/202 and Ser202/Thr205.
AB - To determine if the high phosphate content of paired helical filaments (PHFs) in
Alzheimer's disease (AD) is a result of limited access to filament
phosphorylation sites, we studied in vitro dephosphorylation of intact PHFs, PHFs
with filamentous structure abolished by formic acid treatment (PHF(FA)) and fetal
human tau protein. Samples were treated with alkaline phosphatase for up to 24 h
at 37 degrees C and then immunoblotted with eight well characterized tau
antibodies, that recognize two phosphorylation-insensitive sites and six
phosphorylation-sensitive epitopes at Thr181, Ser199/202, Ser202/Thr205, Thr231,
Ser262/356 and Ser396/404. Intact PHFs were effectively dephosphorylated only at
the two N-terminal epitopes Ser199/202 and Ser202/Thr205, with little change in
electrophoretic mobility. In contrast, PHF(FA) were dephosphorylated at all
epitopes, with particular effectiveness at those in the C-terminus and with
significant increase in electrophoretic mobility. The fetal tau epitopes were
effectively dephosphorylated except at Thr181 and Thr231 with marked increase in
mobility. The extent of dephosphorylation of PHF(FA) was equal or more effective
than in fetal tau, except for Thr181 that was minimally dephosphorylated in both
proteins. The results indicate that intact PHFs, but not PHF(FA) or fetal tau
display differential dephosphorylation of the N- and C-terminal epitopes. The
results confirm that the filamentous conformation may significantly contribute to
hyperphosphorylation of PHFs in the C-terminus. The filamentous conformation,
however, does not limit access to two N-terminal epitopes Ser199/202 and
Ser202/Thr205. The access to these sites in AD may be limited by other factors,
e.g., inhibition of phosphatase binding.
PMID- 10677624
TI - The role of nigral and thalamic output pathways in the expression of oral
stereotypies induced by amphetamine injections into the striatum.
AB - Microinjections of amphetamine into the ventrolateral striatum (VLS) elicit a
striking behavioral syndrome characterized by compulsive oral and forelimb motor
stereotypies. The neural pathways that mediate these behavioral responses
downstream from the striatum have not yet been identified. In a series of
experiments, we investigated the involvement of the substantia nigra pars
reticulata (SNr) and the ventromedial nucleus of the thalamus (VMT) in the
mediation of this behavioral syndrome. We demonstrated that lidocaine-induced
reversible inactivation of the SNr reduced amphetamine-induced stereotyped biting
and gnawing behaviors, suggesting that the nigral output pathway plays a
significant role in the expression of these behavioral responses. In turn,
injections of lidocaine into the VMT only transiently reduced amphetamine
stimulated biting and increased stereotyped gnawing and paw nibbling, suggesting
that the expression of oral stereotypies induced by amphetamine injections into
the VLS is not dependent on thalamocortical feedback.
PMID- 10677625
TI - Fetal alcohol exposure alters serotonin transporter sites in rat brain.
AB - This study examined the effects of fetal alcohol exposure (FAE) on serotonin
transporter (5-HTT) binding sites in the brains of developing male and female rat
offspring using the technique of quantitative autoradiography. Time-pregnant dams
were fed liquid ethanol diet, isocaloric diet without ethanol or normal rat chow.
Male and female offspring were sacrificed at 21, 40 and 60 days of age, brains
removed and sectioned for analysis of 5-HTT sites. FAE led to distinct effects on
5-HTT sites depending on the age and gender of the offspring. FAE increased 5-HTT
binding sites in cortical layers 5, 6, hippocampal layers CA(2,3), lateral
nucleus of the amygdala and in the dorsal raphe nucleus. FAE decreased 5-HTT
binding sites in the medial nucleus of amygdala, dorsomedial and ventromedial
nuclei of the hypothalamus. FAE decreased 5-HTT binding sites temporarily in the
ventromedial nucleus of the hypothalamus in the 21-day-old female; this effect
was found to disappear by day 40. In contrast, FAE increased 5-HTT sites in the
lateral nucleus of the amygdala in the adult animal, suggesting that ethanol
exposure in utero may alter serotonin neurotransmission in discrete brain regions
permanently.
PMID- 10677626
TI - Microinfusion of protein kinase inhibitor H7 into the cerebellum impairs the
acquisition but not the retention of classical eyeblink conditioning in rabbits.
AB - Rabbits were infused with H7, a general protein kinase inhibitor, into the region
of the cerebellar interpositus nucleus during classical eyeblink conditioning.
Acquisition of the conditioned eyeblink response was delayed by the H7 infusion,
but the protein kinase inhibitor had no effect on performance of the learned
response when infused after asymptotic learning had been reached. These data
indicate that protein kinases in the cerebellum are involved in plasticity
processes that underlie the learning of this simple conditioned behavior.
PMID- 10677627
TI - Morphologic and electrophysiologic maturation in developing dentate gyrus granule
cells.
AB - Dentate gyrus granule cells from immature (7-28 days) Sprague-Dawley rats were
examined with whole cell patch clamp recordings and biocytin filling in in vitro
hippocampal slice preparations. Although recordings were confined to the middle
third of the suprapyramidal limb of the dentate, the granule cells exhibited
marked variability in their physiologic properties: input resistance (IR) ranged
from 250 MOmega to 3 GOmega, and resting membrane potential (RMP) from -82 to -41
mV. Both IR and RMP were inversely correlated with dendritic length, a
morphometric indicator of cell maturity. Thus the highest IR cells were the
youngest, and maturation was characterized by a progressive decrease in IR,
hyperpolarization of RMP, and elongation of the dendritic arbor. When cells were
grouped by IR, significant intergroup differences were found in RMP, dendritic
length, and number of dendritic terminal branches. Although cells of all IR
categories were examined throughout the age spectrum under study, none of the
inter-IR group differences was age-dependent. These data suggest that IR provides
a reasonable estimate of granule cell maturity and that maturation entails
predictable changes in cell properties and morphology. These aspects of
maturation correlate with each other, are independent of animal age, and most
likely proceed according to a program related to cell birth.
PMID- 10677628
TI - Aging regulates 5-HT(1B) receptors and serotonin reuptake sites in the SCN.
AB - Middle age is associated with changes in circadian rhythms (e.g., alterations in
the timing of the circadian wheel running rhythm) which resemble changes induced
by selective destruction of the serotonergic input to the suprachiasmatic nucleus
(SCN), the principal mammalian circadian pacemaker. We hypothesized that
serotonergic neurotransmission in the SCN is decreased in middle-aged hamsters,
as compared to young adults. This hypothesis was tested indirectly by
investigating the effect of aging on two markers of serotonin neurotransmission,
5-HT(1B) receptors and serotonin reuptake sites, which are regulated by
serotonin. Previous studies have shown that experimentally induced decreases in
serotonergic neurotransmission increase 5-HT(1B) receptors but decrease serotonin
reuptake sites. Quantitative autoradiography was conducted using
[125I]iodocyanopindolol ([125I]ICYP) and [3H]paroxetine, selective radioligands
for the 5-HT(1B) receptors and the serotonin reuptake sites, respectively.
Consistent with the hypothesis, specific ([125I]ICYP binding was significantly
elevated in the SCN of middle-aged hamsters, as compared to young hamsters. The
results also showed that serotonin reuptake sites in the SCN were significantly
increased in both middle-aged and old hamsters, as compared to young controls.
This result could not have been caused by decreased serotonin release.
Alternatively, increased serotonin reuptake, which would reduce serotonin levels
in the synaptic cleft, may cause or contribute to the increase in 5-HT(1B)
receptor binding in the SCN in middle aged animals. These results show that the
SCN exhibits changes in serotonergic function during middle age, which has been
characterized by changes in the expression of circadian rhythms. Because these
changes occur during middle age, they probably reflect the aging process, rather
than senescence or disease.
PMID- 10677629
TI - Is intracellular brain pH a dependent factor in NOS inhibition during focal
cerebral ischemia?
AB - The interaction between nitric oxide (NO.) and focal cerebral ischemia is
multifaceted. Experiments have shown that inhibition of nitric oxide synthase
(NOS) either ameliorates or exacerbates focal cerebral ischemia. Recent in vitro
experiments have shown that NOS activity is pH-dependent. Previous work from this
laboratory has demonstrated that N(G)-nitro-L-arginine-methyl-ester (L-NAME)
mitigated cerebral ischemia independent from regional cerebral blood flow (rCBF)
changes during moderate focal cerebral ischemia. This study examined the effects
of L-NAME inhibition on brain pH(i), rCBF, and NADH redox state during 3 h of
severe focal cerebral ischemia. Fifteen fasted rabbits under 1.5% halothane were
equally divided into three groups: ischemic controls and two drug groups
receiving either 1.0 or 10 mg/kg L-NAME intravenously 30 min prior to ischemia.
In the ischemic controls, brain pH(i) declined from 6.95+/-0.04 to 6.60+/-0.05,
rCBF declined from 48+/-7 to 10+/-3 ml/100 g/min, and NADH fluorescence increased
by 149+/-15% 3 h after onset of ischemia (p<0.01 for all three parameters). L
NAME at either dose did not significantly alter these values. Infarct volume was
not significantly different between both the L-NAME treated groups and the
ischemic control group. This data suggests that during severe focal cerebral
ischemia, NO. mechanisms of injury have a less important punitive role. One
possible explanation is that the severity of acidosis secondary to anaerobic
metabolism during severe focal cerebral ischemia attenuates NOS activity.
PMID- 10677630
TI - Enhanced analgesic potency and reduced tolerance of morphine in 129/SvEv mice:
evidence for a deficiency in GM1 ganglioside-regulated excitatory opioid receptor
functions.
AB - 10-fold higher doses in SW mice. Furthermore, cotreatment of 129/SvEv mice with
morphine plus a low dose of naltrexone (ca. 0.1 microgram/kg) that markedly
enhances and prolongs morphine's antinociceptive effects in SW mice did not
enhance, and often attenuated6 h. The marked GM1-induced attenuation of
morphine's antinociceptive effects in 129/SvEv mice may be due to conversion of
some of the opioid receptors in these mice from an inhibitory Gi/Go-coupled to an
excitatory Gs-coupled mode. Exogenous GM1 supplementation can, therefore, reverse
the anomalous lack of morphine tolerance displayed by this mouse strain in
comparison to SW and other mice. The present study may provide insights into
factors that regulate the marked variability in nociceptive sensitivity and
opioid tolerance/dependence liability among individual humans.
PMID- 10677631
TI - Flupirtine ameliorates ischaemic-like death of rat retinal ganglion cells by
preventing calcium influx.
AB - The effect of flupirtine on the loss of retinal ganglion cells following
transient elevation of intraocular pressure (experimental ischaemia) or NMDA
induced excitotoxicity was studied. Ischaemia (60 min) or intravitreal injection
of NMDA (20 nmol) caused a decrease in Thy-1 mRNA and Thy-1 immunoreactivity
which are associated with ganglion cells. Administration of flupirtine
counteracted these changes. Moreover, flupirtine dose-dependently inhibited NMDA
induced 45Ca(2+) influx into cultured cortical neurones and retinal pieces in
vitro with maximal inhibition being observed at 200 microM. A similar
concentration of flupirtine failed to inhibit kainate-stimulated calcium influx
into cultured cortical neurones. In addition, flupirtine had no significant
effect on [3H]nitrendipine or [3H]diltiazem binding to cortical membranes. The
present studies are consistent with previous findings which suggested flupirtine
to act as a NMDA antagonist by a mechanism that still remains to be clarified.
PMID- 10677632
TI - Discharge of group IV phrenic afferent fibers increases during diaphragmatic
fatigue.
AB - The discharge of single unit group III (n=7) and group IV (n=8) phrenic afferent
fibers was recorded during rhythmic diaphragmatic contractions before and after
the onset of fatigue. Compared to pre-fatigue impulse activity, group IV, but not
group III, phrenic afferent fibers discharged more (p<0.05) during rhythmic
diaphragmatic contractions when the diaphragm was fatigued. This increase in
group IV fiber discharge during diaphragmatic fatigue provides
electrophysiological evidence consistent with the notion that group IV phrenic
afferent fibers comprise the afferent arm of a fatigue-induced inhibitory reflex
originating in the diaphragm.
PMID- 10677633
TI - Clonidine diminishes c-jun gene expression in the cardiovascular sensitive areas
of the rat brainstem.
AB - The present study investigated the effect of clonidine on the basal and inducible
c-jun and c-fos mRNA expression in the nucleus tractus solitarius (middle, mNTS,
and rostral, rNTS) and the rostral ventrolateral medulla (caudal, cRVLM, and
rostral, rRVLM). Conscious rats received saline, clonidine (30 microg/kg, i.v.),
saline plus sodium nitroprusside (NP), or clonidine plus NP. Under basal
conditions (saline-infused rats), c-jun mRNA was expressed in the mNTS and rRVLM
but not in the rNTS or cRVLM whereas c-fos mRNA was not detectable. Clonidine
attenuated the increases in c-fos in the mNTS and cRVLM and c-jun gene expression
in the mNTS and rRVLM caused by NP-evoked hypotension and also reduced the basal
expression of c-jun mRNA in the mNTS and rRVLM. These findings establish a causal
link between clonidine inhibition of c-fos expression in brainstem and its
hypotensive action, and provide the first evidence that clonidine attenuates the
expression of the closely linked c-jun gene in neurons implicated in centrally
mediated hypotension.
PMID- 10677634
TI - Neostigmine influences the L-dopa-induced extracellular dopamine levels in the
striatum.
AB - Using in vivo microdialysis in freely moving rats, we show that the addition to
the dialysis perfusion fluid of the acetylcholinesterase inhibitor neostigmine
influences the decarboxylation of levodopa (L-dopa). Continuous perfusion of
neostigmine (10, 50 and 100 nM) in striatum attenuated the L-dopa-induced
dopamine release in a dose-dependent manner. This effect suggests that changes in
magnitude of drug responses may occur when an acetylcholinesterase inhibitor is
included in the perfusion solution. Results obtained under these circumstances
should be carefully interpreted concerning the pharmacological effects of other
drugs when used concomitantly with neostigmine.
PMID- 10677635
TI - The interstitial nuclei of the human anterior hypothalamus: an investigation of
sexual variation in volume and cell size, number and density.
AB - The four interstitial nuclei of the anterior hypothalamus (INAH) have been
considered as candidate human nuclei for homology with the much studied sexually
dimorphic nucleus of the preoptic area of the rat. Assessment of the INAH for
sexual dimorphism has produced discrepant results. This study reports the first
systematic examination of all four INAH in the human for sexual variation in
volume, neuronal number and neuronal size. Serial Nissl-stained coronal sections
through the medial preoptic area and anterior hypothalamus were examined from 18
males and 20 females who died between the ages of 17 and 65 without evidence of
hypothalamic pathology or infection with the human immunodeficiency virus. A
computer-assisted image-analysis system and commercial stereology software
package were employed to assess total volume, neuronal number and mean neuronal
size for each INAH. INAH3 occupied a significantly greater volume and contained
significantly more neurons in males than in females. No sex differences in volume
were detected for any of the other INAH. No sexual variation in neuronal size or
packing density was observed in any nucleus. The present data corroborate two
previous reports of sexual dimorphism of INAH3 but provide no support for
previous reports of sexual variation in other INAH.
PMID- 10677636
TI - U-69,593 microinjection in the infralimbic cortex reduces anxiety and enhances
spontaneous alternation memory in mice.
AB - The present report investigated the contributions of the ventromedial prefrontal
cortex to the control of spontaneous alternation/working memory and anxiety
related behaviour. In Experiment 1, we examined the effects of microinjections of
the selective kappa(1) receptor agonist, U-69,593, in the infralimbic cortex (IL)
of CD-1 mice on several ethologically-derived anxiety indices in the elevated
plus-maze (EPM) and defensive/withdrawal (D/W) anxiety in the open field, as well
as on memory in the EPM transfer-latency (T-L) test and implicit spontaneous
alternation memory (SAP) in the Y-maze. In week 1, pretreatment with one
injection of vehicle, 1, 10 or 25 nmol/1.0 microliter U-69,593 in the IL dose
dependently prolonged T-L and produced a dose-dependent anxiolytic behavioural
profile in the first EPM trial. Following a 24-h delay, the same mice were given
a drug-free second trial in the EPM tests of T-L memory and anxiety. Whereas T-L
memory was not disturbed, small but detectable carry-over effects were observed
in trial-2 EPM behaviour relative to vehicle-treated animals. In week 2, the same
groups of mice were again pretreated with one injection of the same doses of U
69,593 in the IL and given a D/W test in an open field, followed immediately by
an 8-min SAP trial in the Y-maze. The smallest U-69,593 dose was anxiolytic in
the D/W test, and SAP/working memory was dose-dependently enhanced in the Y-maze.
In Experiment 2, we evaluated whether 0.5 microliter volume microinjections would
produce comparable behavioural and carry-over effects in the IL of three new
groups of CD-1 mice, in the event that the 1.0 microl volume injections used in
Experiment 1 diffused beyond the IL and therefore may have confounded some
effects. Experiment 2 procedures were carried out in the same manner as in
Experiment 1, except the animals were tested in reverse order. Thus in week 1,
SAP memory was tested in the Y-maze followed by D/W anxiety in the open field for
half of the animals in each group, and the other half was tested in reverse
order. In week 2, T/L memory and anxiety were tested in the EPM in 2 trials as
described in Experiment 1. Pretreatment with one injection of vehicle, 10 or 25
nmol/0.5 microliter U-69,593 in the IL reduced D/W anxiety and enhanced SAP
memory regardless of testing order in week 1. In week 2, the same groups of mice
were again pretreated with one injection of the same doses of U-69,593 in 0.5
microliter volumes in the IL and tested in the EPM. In a similar fashion to
Experiment 1, U-69,593 dose-dependently prolonged T/L and produced an anxiolytic
behavioural profile in the first EPM trial. Following a 24-h delay, T/L recall
memory was again not significantly influenced, but a robust anxiolytic
behavioural profile was observed in the second drug-free anxiety trial in the EPM
relative to vehicle-treated animals. Results are discussed relative to a)
injection volumes and testing order, b) the possible influence kappa receptors
may exert on neurochemical responsivity to anxiety-provoking environments in the
IL area of the mPFC, c) the possibility that kappa-mediated anxiolysis from the
IL in CD-1 mice results from interactions with neurochemical systems involved in
the blunting of incoming anxiety-provoking information, d) evidence that SAP
memory may be an implicit subtype of working memory, and e) the possibility that
IL implicit working memory processes may modulate the induction and expression of
anxiety-related behaviour.
PMID- 10677637
TI - Comparison of cytosine arabinoside delivery to rat brain by intravenous,
intrathecal, intraventricular and intraparenchymal routes of administration.
AB - We evaluated the delivery of 14C-cytosine arabinoside (AraC) to rat brain by: 1)
intravenous (IV) bolus, by 2) intrathecal (IT) and 3) intraventricular (IVT)
infusion, and by 4) convection-enhanced delivery (CED) into the caudate nucleus.
Plasma and brain AraC metabolites were measured with HPLC, and distribution and
concentration of 14C-AraC in brain sections were measured by quantitative
autoradiography. After IV administration, the alpha and beta plasma half-lives
were 1.9 and 46.5 min, respectively. The blood-to-brain transfer constant of AraC
was 2.5+/-1.4 microliter g(-1) min(-1), compatible with high water solubility.
After IT and IVT administration, tissue levels were high at the brain and
ventricular surfaces, but declined exponentially into brain. After CED, maximum
brain levels were up to 10,000 times higher than the IV group, and the
distribution pattern was one of high 14C-AraC concentration in the convective
component, with exponentially declining concentrations outside this region. The
rate loss constant from brain was 0.002+/-0.0004 min(-1), suggesting that AraC
was accumulating in brain cells. AraC was metabolized into uracil arabinoside
within the brain. 14C-AraC was infused into 1 dog and distributed widely in the
ipsilateral hemisphere. These studies suggest that delivery of AraC to brain
parenchyma by the IV, IT or IVT routes will be subtherapeutic. Delivery by CED
can achieve, and maintain, therapeutic levels of AraC in the brain, and should be
further evaluated as a potential method of drug delivery.
PMID- 10677638
TI - Brain activation during human finger extension and flexion movements.
AB - Corticospinal projections to the motor neuron pool of upper-limb extensor muscles
have been reported to differ from those of the flexor muscles in humans and other
primates. The influence of this difference on the central nervous system control
for extension and flexion movements is unknown. Cortical activation during thumb
extension and flexion movements of eight human volunteers was measured using
functional magnetic resonance imaging (fMRI), which detects signal changes caused
by an alteration in the local blood oxygenation level. Although the relative
activity of the extensor and flexor muscles of the thumb was similar, the brain
volume activated during extension was substantially larger than that during
flexion. These fMRI results were confirmed by measurements of EEG-derived
movement-related cortical potential. Higher brain activity during thumb extension
movement may be a result of differential corticospinal, and possibly other
pathway projections to the motoneuron pools of extensor and flexor muscles of
upper the extremities.
PMID- 10677639
TI - Striatal trophic activity is reduced in the aged rat brain.
AB - Our previous studies demonstrated that the survival of a mesencephalic graft was
reduced in aged animals suggesting an age-related decline in target-derived
neurotrophic activity. We tested this hypothesis by examining dopamine (DA) and
trophic activities from the striatum of intact or unilateral 6-hydroxydopamine (6
OHDA) lesioned rats of increasing age. Fisher 344 rats were 4, 12, 18, and 23
months old (m.o.) at sacrifice. Half the animals had received unilateral 6-OHDA
lesions of the mesostriatal DA pathway 8 weeks earlier. Striatal tissue punches
were analyzed for DA, homovanillic acid (HVA), and DA activity (HVA/DA) using
HPLC. The remainder of the striatal tissue was homogenized to generate tissue
extracts which were added to E14.5 ventral mesencephalic cultures to test trophic
activity. In the non-lesioned animals, striatal DA was reduced and striatal DA
activity was increased in the 18 and 23 m.o. animals relative to the 4 and 12
m.o. animals. Striatal trophic activity was inversely related to age. In the
lesioned animals, striatal DA ipsilateral to 6-OHDA infusion was below detection
limits while the contralateral striatum exhibited age-related changes in DA
similar to those seen in the non-lesioned animals. In 4 m.o. lesioned rats,
striatal trophic activity ipsilateral to 6-OHDA infusion was elevated by 26%
relative to the contralateral side. The ipsi/contra-lateral differences in
striatal trophic activity were reduced in 12 m.o. animals and absent in the 18
and 23 m.o. groups. These data suggest that advancing age is associated with a
reduction in striatal DA as well as trophic activity. Moreover, the aged striatum
loses its ability to biochemically and trophically compensate for DA reduction
and therefore may represent a more challenging environment for the survival,
growth, and function of a fetal graft.
PMID- 10677640
TI - The role of the International Organization of Psychophysiology (IOP) in the 20th
century and its promising march towards the 21st.
AB - In this Presidential Address, the contribution of the International Organization
of Psychophysiology (IOP) to the 20th century is summarized. Its official
relationship with the United Nations and other international bodies is discussed.
Future trends paving the way for the 21st Century as the 'Century of the Brain'
are emphasized. The importance of psychophysiology to Humanity is underlined.
PMID- 10677641
TI - Brain oscillations in perception and memory.
AB - Gamma oscillations, now widely regarded as functionally relevant signals of the
brain, illustrate that the concept of event-related oscillations bridges the gap
between single neurons and neural assemblies. Taking this concept further, we
review experiments showing that oscillatory phenomena such as alpha, theta, or
delta responses to events are strongly interwoven with sensory and cognitive
functions. This review argues that selectively distributed delta, theta, alpha,
and gamma oscillatory systems act as resonant communication networks through
large populations of neurons. Thus, oscillatory processes might play a major role
in relation with memory and integrative functions. A new 'neurons-brain' doctrine
is also proposed to extend the neuron doctrine of Sherrington.
PMID- 10677642
TI - Near-infrared spectroscopy: does it function in functional activation studies of
the adult brain?
AB - Changes in optical properties of biological tissue can be examined by near
infrared spectroscopy (NIRS). The relative transparency of tissues including the
skull to near-infrared light is the prerequisite to apply the method to brain
research. We describe the methodology with respect to its applicability in non
invasive functional research of the adult cortex. A summary of studies
establishing the 'typical' response in NIRS vascular parameters, i.e. changes in
the concentration of oxygenated and deoxygenated haemoglobin, over an activated
area is followed by the validation of changes in the cytochrome-oxidase redox
state in response to a visual stimulus. Proceeding from these findings a rough
mapping of this metabolic response over the motion-sensitive extrastriate visual
area is demonstrated. NIRS measures concentration changes in deoxygenated
haemoglobin [deoxy-Hb] which are assumed to be the basis of fMRI BOLD contrast
(blood oxygenation level-dependent). The method is therefore an excellent tool to
validate assumptions on the physiological basis underlying the fMRI signal, due
to its high specificity as to the parameters measured. Questions concerning the
concept of 'activation'/'deactivation' and that of the linearity of the vascular
response are discussed. To challenge the method we finally present results from a
complex single-trial motor paradigm study testing the hypothesis, that premotor
potentials (contingent negative variation) can be examined by functional
techniques relying on the vascular response. Some of the work described here has
been published elsewhere.
PMID- 10677643
TI - Lonely traits and concomitant physiological processes: the MacArthur social
neuroscience studies.
AB - Loneliness is a complex set of feelings encompassing reactions to unfulfilled
intimate and social needs. Although transient for some individuals, loneliness
can be a chronic state for others. Prior research has shown that loneliness is a
major risk factor for psychological disturbances and for broad-based morbidity
and mortality. We examined differences between lonely and socially embedded
individuals that might explain differences in health outcomes. Satisfying social
relationships were associated with more positive outlooks on life, more secure
attachments and interactions with others, more autonomic activation when
confronting acute psychological challenges, and more efficient restorative
behaviors. Individuals who were chronically lonely were characterized by elevated
mean salivary cortisol levels across the course of a day, suggesting more
discharges of corticotropin-releasing hormone and elevated activation of the
hypothalamic-pituitary-adrenocorticol axis. An experimental manipulation of
loneliness further suggested that the way in which people construe their self in
relation to others around them has powerful effects on their self concept and,
possibly, on their physiology.
PMID- 10677644
TI - Cortical dynamics of memory.
AB - Memory networks are formed in the cerebral cortex by associative processes,
following Hebbian principles of synaptic modulation. Sensory and motor memory
networks are made of elementary representations in cell assemblies of primary
sensory and motor cortex (phyletic memory). Higher-order individual memories,
e.g. episodic, semantic, conceptual - are represented in hierarchically organized
neuronal networks of the cortex of association. Perceptual memories are organized
in posterior (post-rolandic) cortex, motor (executive) memories in cortex of the
frontal lobe. Memory networks overlap and interact profusely with one another,
such that a cellular assembly can be part of many memories or networks. Working
memory essentially consists in the temporary activation of a memory network, as
needed for the execution of successive acts in a temporal structure of behavior.
That activation of the network is maintained by recurrent excitation through
reentrant circuits. The recurrent reentry may occur within local circuits as well
as between separate cortical areas. In either case. recurrence binds together the
associated components of the network and thus of the memory it represents.
PMID- 10677645
TI - Visuomotor neurons: ambiguity of the discharge or 'motor' perception?
AB - The cortical motor system has been classically considered as the unitary, output
stage of the brain processing of sensory information. According to this idea, the
motor cortex - the acting brain - receives the result of the perceptual
processing (visual, acoustical, tactile, etc.) elaborated by the 'associative
cortex'. During the last two decades this perspective has been challenged by a
series of anatomical, hodological, and neurophysiological data. This converging
evidence delineates a dramatically changed picture. Far from being unitary, the
cortical motor system appears to be constituted by a constellation of distinct
areas, each of those endowed with specific functional properties and linked by
reciprocal connections with distinct sectors of the parietal cortex. Furthermore,
several 'motor' neurons in addition to their motor discharge, are also activated
by somatosensory and visual stimulation (somatomotor and visuomotor neurons). In
the present paper we will discuss the functional properties of those sensorimotor
neurons located in the ventral part of the monkey premotor cortex. On the basis
of electrophysiological data, we will propose that the apparent parodox stemming
from the coexistence within the same neuron of motor and sensory properties can
be solved by postulating that the motor system not only executes actions but also
internally represents them in terms of 'motor ideas'. These motor ideas may
provide the neurobiological basis for space representation, understanding of
actions made by others and, possibly, semantic categorization of objects.
PMID- 10677646
TI - Hierarchical neuronal modeling of cognitive functions: from synaptic transmission
to the Tower of London.
AB - Recent progress in the molecular biology of synaptic transmission, in particular
of neurotransmitter receptors, offers novel information relevant to 'realistic'
modeling of neural processes at the single cell and network level. Sophisticated
computer analyses of two-dimensional crystals by high resolution electron
microscopy yield images of single neurotransmitter receptor molecules with
tentative identifications of ligand binding sites and of conformational
transitions. The dynamics of conformational changes can be accounted for by a
'multistate allosteric network' model. Allosteric receptors also possess the
structural and functional properties required to serve as coincidence detectors
between pre- and post-synaptic signals and, therefore, can be used as building
blocks for a chemical Hebb synapse. These properties were introduced into
networks of formal neurons capable of producing and detecting temporal sequences.
In more elaborate models of pre-frontal cortex functions, allosteric receptors
control the selection of transient 'pre-representations' and their stabilization
by external or internal reward signals. We apply this scheme to Shallice's Tower
of London test, and we show how a hierarchical neuronal architecture can
implement executive or planning functions associated with frontal areas.
(Academie des sciences/Elsevier, Paris.)
PMID- 10677647
TI - Role of neurotrophins in the development and plasticity of the visual system:
experiments on dark rearing.
AB - An extensive series of studies, beginning with the pioneering experiments of
Wiesel and Hubel, have shown that correct visual experience is crucial for the
development of the visual system. Several years ago, we put forward the
hypothesis that neurotrophic factors of the neurotrophin family (NGF, BDNF, NT-3,
NT-4) have a role in mediating the effects of visual experience in the developing
visual system. This theory is based on the following experimental results: (a)
exogenous supply of neurotrophins during the critical period prevents the effects
of monocular deprivation; and (b) transplant of cells releasing NGF allows a
normal development of the functional properties of visual cortical neurons in
dark-reared rats.
PMID- 10677648
TI - Perception and the conditioning reflex: vector encoding.
AB - Color perception is dependent on the generation of an excitation vector which,
acting on a pool of color detectors (color detector map), produces a
corresponding sensation. The generation of the color excitation vector starts at
the retinal level, proceeds in the lateral geniculate body, and reaches color
detectors at the cortical level. Following processing at the level of declarative
memory and semantic maps, results in a verbal categorization of colors. Parallel
to the excitation vector pathway, a network computing color differences is
operating. The computation of color differences at the retinal level possibly
takes place in phasic bipolar cells and progresses in the lateral geniculate body
and at the cortical level. Detectors of color differences are assumed to be a
basis of respective numerical estimations in humans. Data from frogs, fish,
monkeys and humans are compared.
PMID- 10677649
TI - Psychophysiology by the end of the 20th century.
AB - The first real breakthrough in the research of brain organization and thinking in
the 20th century was made in neurophysiological investigations performed in
direct contact with different sites of the brain, which became possible in
diagnosis and treatment. The second breakthrough is happening at present. It is
based on the opportunities provided by the non-invasive technique. The theory of
the unique character of the brain system consisting of rigid and flexible
elements maintaining thinking was created as well as concepts on the reliability
in the system, of the error detector and intrinsic protective mechanisms of the
brain. In the clinic these data enabled us to help patients who had lost various
functions due to stroke. In confirmation with the above theory it was revealed
that the same task could be solved in the brain by systems consisting of
different elements due to environmental changes or even direction of attention.
Data on the functional properties or every zone of the cortex and subcortex as
well as cerebellum are rapidly increasing in number. The first priority lies in
neurophysiologically penetrating into the physiological character and micromosaic
of the activation sites of PET. The main aim of future brain research lies in the
investigation of the fine physiological rearrangements which underlie thinking,
i.e. deciphering its brain code. This is going to be the basis for the third,
extremely valid breakthrough in the research on brain organization of thinking.
PMID- 10677650
TI - Neuronal imprinting of human values.
AB - In the 21st century, psychophysiology will face the challenge of establishing
ethical principles and practical means for the genetic and social influencing of
the development of human beings. Neuronal imprinting of beliefs and morality
within infantile minds will be necessary for the peaceful coexistence of races
and cultures. This process requires study and consideration, among others, of the
following psychophysiological facts: (1) Genes do not transmit moral values. (2)
Material support of physiological activities is necessary for the existence and
development of mental functions. (3) Imprinting of human values is based on
material changes within neuronal structures. (4) Early neuronal imprinting is
performed without personal awareness or consent of the individual and depends on
sensory inputs, mainly from the social structure of the group. (5) Biological
structures lack values. Personal and social antagonisms do not depend on genes,
but on cultural indoctrination. (6) Pleasure and punishment (positive and
negative reinforcement) are the two main elements, which regulate animal and
human behavior. (7) Values must be chosen by adults, who decide the questions
'why'? 'when'? 'which ones'?, 'who should teach'?, 'what?' and 'how'? (8) Many
biological imperatives are shared by all animals and by all people. Human beings
may be considered the 'crickets of the Universe', unable to understand the
mysteries of nature because of our insufficient neuronal capacity. (9) Our
emotional life is mainly related to the structure of the limbic system controlled
by the neocortex. (10) New theories based on the integration of physics,
chemistry, biology and other specific areas of knowledge, as proposed by the
General Theory of Systems, will avoid 'opposites', favoring the acceptance of
complementary aspects of reality. (11) Early education will promote preferential
learning which depends on both genetic endowment and neuronal development
influenced by experience. It is the responsibility of psychophysiology to
establish the guidelines for better education, clarifying the material and
psychological aspects of the mind.
PMID- 10677651
TI - The assessment and management of third party risk around a major airport.
AB - Schiphol, the main airport of the Netherlands, is growing rapidly. The aircraft
movements, also growing in number, place a considerable environmental burden on
the surrounding population, notably, noise and odour nuisance and risks. In the
process of deciding on how to extend the capacity of the airport to accommodate
the anticipated twofold growth in the number of movements with respect to 1990,
environmental problems form a major concern. The concern about risks for the
surrounding population was enhanced after the crash on 4 October 1992, in which a
Boeing 747 cargo carrier bored into a block of flats in a suburb of Amsterdam
near Schiphol. In this accident, the four crew members were killed, together with
39 inhabitants of the flats/apartment building. These risks were studied as part
of the Environmental Impact Assessment (EIA). To make these studies useful for
decision making necessitated a major improvement in the available techniques for
risk quantification. The results of the quantitative analyses, using several
different methods, have all indicated that the activities of Schiphol pose a
considerable risk compared to other major industrial activities in the
Netherlands. This paper describes the development of the methodology from 1990 in
the light of the policy context in which it took place. Use of the methods in the
decision-making process is illustrated by describing the current status of this
process.
PMID- 10677652
TI - Integrated safety planning for underground systems.
AB - Underground systems are becoming increasingly popular for business activities,
transportation systems, and storage purposes. Safety planning for underground
systems calls for an integrated approach which considers the interests of many
parties, the dynamics of different activities, and the potential threats posed by
hazardous materials. A visual interactive modeling approach is presented which
helps organizations to derive a safety concept for underground systems. The
modeling approach emphasizes procedural aspects of dealing with multiple parties,
as well as conceptual and analytic aspects of assessing risks and defining safety
goals. The paper summarizes the framework for developing a safety concept for
underground systems which was developed for the Dutch Ministry of the Interior. A
hypothetical example is discussed to illustrate the theoretical constructs.
PMID- 10677653
TI - Application of risk assessment and decision analysis to the evaluation, ranking
and selection of environmental remediation alternatives.
AB - A single framework integrating risk assessment and decision analysis methods for
evaluating, ranking and selecting preferred remediation alternatives at a
contaminated site was developed and demonstrated. The methodology used relies on
stakeholder inputs throughout the entire process and employs those inputs to
combine the results of multiple risk assessments to arrive at a total impact for
each remediation alternative. The total impact values allow the ranking of the
alternatives, which in turn, serves as the basis for deliberations among the
stakeholders in order to identify the preferred alternative. Six major risk or
impact categories were considered in the evaluation of the alternatives: human
health and safety, environmental protection, life cycle cost, socio-economics,
cultural, archeological and historical resources, and programmatic assumptions.
PMID- 10677654
TI - Risk analysis and safety policy developments in the Netherlands.
AB - In the Netherlands, external safety policy has been developed and implemented
since the early eighties on the basis of a risk-based approach involving
quantitative criteria for the tolerability of risk. Good experiences have been
gained with the risk policy that applies to some 4000 establishments in the
Netherlands where hazardous substances are present. On the basis of these
experiences, legislation is now being prepared to give the risk tolerability
criteria a full legal basis. This is aimed, in particular, to balance between
risk control measures at the source through the licensing system, and spatial
planning instruments to protect, e.g. residential areas against major hazards.
The revision of the Seveso directive (96/82/EC) leads to the implementation of an
integrated form of safety reporting, evaluation and inspection. Practical tools
were developed for this implementation, e.g. for facilitating the selection of
establishments and for assessing risks from major hazard establishments to
surface water. In the past few years, the application of risk-based safety policy
has been extended to other fields than establishments, e.g. for transport of
hazardous chemicals and external safety of airports.
PMID- 10677655
TI - Risk management of LPG transport activities in Hong Kong.
AB - This paper gives a background to risk management of liquefied petroleum gas (LPG)
transport activities, with special regard to the activities taking place in Hong
Kong. In particular, it looks at the recent activities undertaken by the
Government of the Hong Kong Special Administrative Region (SAR); the recent risk
assessment of LPG transport in the Territory, the measures developed to minimise
the risks (including risk management improvements) and the risk management
activities undertaken by the Government and the operators.
PMID- 10677656
TI - Human factors impact on risk analysis of complex systems.
AB - This paper discusses the methods and techniques that are applied for including
human factors considerations into risk analysis of modern plants. The application
of new control design principles and the extensive use of automation have
strongly modified the role of operators, who have progressively become
supervisors of automatically performed procedures and decision makers in a
context of shared management processes. This implies that cognitive functions and
organisational factors affect risk analysis much more than behavioural and
physical performances. Another crucial issue of human reliability assessment
concerns the dynamic nature of human-machine interaction. This feature covers a
wide spectrum of real situations, but demands quite complex and extensive data.
These considerations favour the development of new and evolutionary techniques
which must be confronted with the requirements and needs of different types of
risk analysis be carried out for different objectives, such as quantitative risk
analysis, safety management, accident investigation, risk-based decision making
and risk-based regulations. Advantages and areas of application of different
techniques are briefly discussed, without attempting to develop a detailed
comparison.
PMID- 10677657
TI - 'Worst case' methodology for the initial assessment of societal risk from
proposed major accident installations.
AB - This paper considers the application of one of the weighted risk indicators used
by the Major Hazards Assessment Unit (MHAU) of the Health and Safety Executive
(HSE) in formulating advice to local planning authorities on the siting of new
major accident hazard installations. In such cases the primary consideration is
to ensure that the proposed installation would not be incompatible with existing
developments in the vicinity, as identified by the categorisation of the existing
developments and the estimation of individual risk values at those developments.
In addition a simple methodology, described here, based on MHAU's "Risk Integral"
and a single "worst case" even analysis, is used to enable the societal risk
aspects of the hazardous installation to be considered at an early stage of the
proposal, and to determine the degree of analysis that will be necessary to
enable HSE to give appropriate advice.
PMID- 10677658
TI - Mitigation of dense gas releases in buildings: use of simple models.
AB - When an accidental release of a hazardous material is considered within a safety
case or risk assessment, its off-site effects are generally assessed by
calculating the dispersion of vapour from the site. Although most installations
handling flammables will be in the open air, many types of plant, particularly
those handling toxics, are enclosed, partly to provide some form of containment
and hence to mitigate the effects of any release. When such a release occurs
within a building, the gas or vapour will undergo some mixing before emerging
from any openings. The degree of mixing will depend upon the building geometry
and the nature of the ventilation, which in turn may be modified by the leak.
This situation is considered in this paper, with specific application to
calculating the rate of release of a dense vapour from a building. All the
calculations presented are based upon simple zone modelling, such that the region
occupied by the vapour is assumed to be well mixed, and, in the isothermal case,
either its concentration or its depth increases as it is fed by the gas leak.
Transfer of air or gas/air mixture through the building openings is estimated by
use of standard ventilation calculation methods. For the non-isothermal case, a
preliminary model is presented in which it is assumed that there is complete
mixing throughout the building and no wind-driven ventilation effects. A moderate
release of chlorine is used as an example, and results are shown of the effects
of various ventilation possibilities on the release rate to the atmosphere. In
addition, comparisons are given between model results and experimental data,
demonstrating the level of confidence which can be placed in the models, and also
identifying areas where there is scope for further improvement.
PMID- 10677659
TI - Consequence analysis in LPG installation using an integrated computer package.
AB - This paper presents the prototype of the computer code, Atlantide, developed to
assess the consequences associated with accidental events that can occur in a LPG
storage plant. The characteristic of Atlantide is to be simple enough but at the
same time adequate to cope with consequence analysis as required by Italian
legislation in fulfilling the Seveso Directive. The application of Atlantide is
appropriate for LPG storage/transferring installations. The models and
correlations implemented in the code are relevant to flashing liquid releases,
heavy gas dispersion and other typical phenomena such as BLEVE/Fireball. The
computer code allows, on the basis of the operating/design characteristics, the
study of the relevant accidental events from the evaluation of the release rate
(liquid, gaseous and two-phase) in the unit involved, to the analysis of the
subsequent evaporation and dispersion, up to the assessment of the final
phenomena of fire and explosion. This is done taking as reference simplified
Event Trees which describe the evolution of accidental scenarios, taking into
account the most likely meteorological conditions, the different release
situations and other features typical of a LPG installation. The limited input
data required and the automatic linking between the single models, that are
activated in a defined sequence, depending on the accidental event selected,
minimize both the time required for the risk analysis and the possibility of
errors. Models and equations implemented in Atlantide have been selected from
public literature or in-house developed software and tailored with the aim to be
easy to use and fast to run but, nevertheless, able to provide realistic
simulation of the accidental event as well as reliable results, in terms of
physical effects and hazardous areas. The results have been compared with those
of other internationally recognized codes and with the criteria adopted by
Italian authorities to verify the Safety Reports for LPG installations. A brief
of the theoretical basis of each model implemented in Atlantide and an example of
application are included in the paper.
PMID- 10677660
TI - Use of QRA for decision support in the design of an offshore oil production
installation.
AB - QRA is today widely used as a tool for decision support in the offshore industry.
Its use has gradually changed from a prescribed analysis for verification
purposes to a tool being actively used in an integrated mode. The paper describes
its use in the design of a modern offshore platform. The paper addresses work
methodology, selection of tools and data, organisation of QRA with other
activities. Specific examples are given.
PMID- 10677661
TI - Mitigation of dense gas releases within buildings: validation of CFD modelling.
AB - When an accidental release of a hazardous material is considered within a safety
case or risk assessment, its off-site effects are generally assessed by
calculating the dispersion of vapour from the site. Although most installations
handling flammable materials will be in the open air, many types of plant,
particularly those handling toxics, are enclosed, partly to provide some form of
containment and hence, to mitigate the effects of any release. When such a
release occurs within a building, the gas or vapour will undergo some mixing
before emerging from any opening. The degree of mixing will depend upon the
building geometry and the nature of the ventilation, which in turn may be
modified by the leak. This situation is considered in this paper, with specific
application to calculating the rate of release of a dense vapour from a building.
The paper describes the application of computational fluid dynamics (CFD)
techniques to modelling the release and mixing processes within buildings.
Examples of validation calculations for simple geometric arrangements, as well as
more complex geometries representative of an industrial site, are described. The
results demonstrate the capabilities of CFD for this application but highlight
the need for careful modelling of the near-wall flows and heat transfer, and need
for an accurate fluid dynamics and thermodynamic representation of the release
source.
PMID- 10677662
TI - Improved nuclear power plant operations and safety through performance-based
safety regulation.
AB - This paper illustrates some of the promise and needed future work for risk
informed, performance-based regulation (RIPBR). RIPBR is an evolving alternative
to the current prescriptive method of nuclear safety regulation. Prescriptive
regulation effectively constitutes a long, fragmented checklist of requirements
that safety-related systems in a plant must satisfy. RIPBR, instead, concentrates
upon satisfying negotiated performance goals and incentives for judging and
rewarding licensee behavior to improve safety and reduce costs. In a project
reported here, a case study was conducted concerning a pressurized water reactor
(PWR) emergency diesel generator (EDG). Overall, this work has shown that the
methods of RIPBR are feasible to use, and capable of justifying simultaneous
safety and economic nuclear power improvements. However, it also reveals several
areas where the framework of RIPBR should be strengthened. First, researchers
need better data and understanding regarding individual component-failure modes
that may cause components to fail. Not only are more data needed on failure
rates, but more data and understanding are needed to enable analysts to evaluate
whether these failures become more likely as the interval between tests is
increased. This is because the current state of failure data is not sufficiently
finely detailed to define the failure rates of individual component failure
modes; such knowledge is needed when changing component-specific regulatory
requirements. Second, the role of component testing, given that a component has
failed, needs to be strengthened within the context of RIPBR. This includes
formulating requirements for updating the prior probability distribution of a
component failure rate and conducting additional or more frequent testing.
Finally, as a means of compensating for unavoidable uncertainty as an obstacle to
regulatory decision-making, limits to knowledge must be treated explicitly and
formally. This treatment includes the formulation of probabilities through expert
solicitation and the review of risk-informed, performance-based and engineering
analyses used to evaluate proposed changes to existing technical specifications.
PMID- 10677663
TI - Statistical analysis of domino chemical accidents.
AB - A set of chemical accidents is retrieved from the literature and classified with
regard to the substance involved and whether domino effects are present. This set
of accidents and each of the classes defined are statistically analyzed with
respect to its severity and comparison is made between domino and non-domino
accidents. The analysis reveals that each accident category shows characteristic
patterns in terms of fatalities caused and domino effects likelihood. Moreover,
chemical accidents severity frequencies are described by using a two-parameter,
revised form of the Pareto probability density function. The range within which
the values of the parameters lie is investigated using Bayesian inference.
PMID- 10677664
TI - Uncertainty in compartmental models for hazardous materials - a case study.
AB - Performing uncertainty analysis on compartmental models is the main topic of this
article. Elements of the methodology developed during a joint CEC/USNRC accident
consequence code uncertainty analysis are introduced. The uncertainty is
quantified using structured expert judgment. Experts are queried about physically
observable quantities. Many code input parameters of the accident consequence
codes are not physically observable but are used to predict observable
quantities. Therefore, a probabilistic inversion technique was developed which
'transfers' the uncertainty from the physically observable quantities to the code
input parameters. The probabilistic inversion technique is illustrated using the
compartmental model of systemic retention of Sr in the human body. The article is
concluded with a discussion on capturing uncertainty via compartmental models.
PMID- 10677665
TI - Standard methods for land-use planning to determine the effects on societal risk.
AB - In the Netherlands, the individual risk and the societal risk are used in efforts
to reduce the number of people exposed to the effects of an accident. In
principle, the societal risk for each new land-use plan should be recalculated.
Since this is proving increasingly cumbersome for planning agencies, several
methods have been developed for SEVESO establishments and establishments for
which in the Netherlands a generic zoning policy is used to determine the effects
of new land-use plans on the societal risk. The methods give the uniform
population density from a certain distance around the establishment at which the
indicative limit for the societal risk is not exceeded. Correction factors are
determined for non-uniform population distributions around the establishment, non
continuous residence times and deviating societal risk limits. Using these
methods allows decision-making without the necessity of repeating quantified risk
analyses for each alternative proposal.
PMID- 10677666
TI - Hazardous materials transportation: a risk-analysis-based routing methodology.
AB - This paper introduces a new methodology based on risk analysis for the selection
of the best route for the transport of a hazardous substance. In order to perform
this optimisation, the network is considered as a graph composed by nodes and
arcs; each arc is assigned a cost per unit vehicle travelling on it and a vehicle
capacity. After short discussion about risk measures suitable for linear risk
sources, the arc capacities are introduced by comparison between the societal and
individual risk measures of each arc with hazardous materials transportation risk
criteria; then arc costs are defined in order to take into account both
transportation out-of-pocket expenses and risk-related costs. The optimisation
problem can thus be formulated as a 'minimum cost flow problem', which consists
of determining for a specific hazardous substance the cheapest flow distribution,
honouring the arc capacities, from the origin nodes to the destination nodes. The
main features of the optimisation procedure, implemented on the computer code
OPTIPATH, are presented. Test results about shipments of ammonia are discussed
and finally further research developments are proposed.
PMID- 10677667
TI - Developments in vapour cloud explosion blast modeling.
AB - TNT Equivalency methods are widely used for vapour cloud explosion blast
modeling. Presently, however, other types of models are available which do not
have the fundamental objections TNT Equivalency models have. TNO Multi-Energy
method is increasingly accepted as a more reasonable alternative to be used as a
simple and practical method. Computer codes based on computational fluid dynamics
(CFD) like AutoReaGas, developed by TNO and Century Dynamics, could be used also
in case a more rigorous analysis is required. Application of the Multi-Energy
method requires knowledge of two parameters describing the explosion: a charge
size and a charge strength. During the last years, research has led to an
improved determination of the charge strength (i.e., the class number or source
overpressure) to be chosen to apply the blast charts. A correlation has been
derived relating the charge strength to a set of parameters describing the
boundary conditions of the flammable cloud and the fuel in the cloud. A simple
approach may not be satisfactory in all situations. The overpressure distribution
inside a vapour cloud explosion is generally not homogeneous and the presence of
obstructions causes directional blast propagation in the near field. A CFD
approach, in which the actual situation is modeled, supplies case-specific
results. An overview of the key aspects relevant to the application of the Multi
Energy method and CFD modeling is provided. Then the application of the two
methods is demonstrated for an example problem involving the calculation of the
explosion blast load on a structure at some distance from the explosion in an
offshore platform complex.
PMID- 10677668
TI - Decision support in nuclear emergencies.
AB - In a nuclear emergency, protective actions such as evacuation, sheltering and
food bans can be taken to mitigate the consequences of any release of
radioactivity. Within the RODOS project, an evaluation framework has been
developed to support the assessment of the costs and benefits of potential
actions. In order to help the decision makers gain insight into the decision
problem and clarify their preferences, guidance can be given in three stages.
First, the search of feasible portfolios of protective actions is seen as a
constraint satisfaction problem; only those portfolios that satisfy constraints
depending on factors such as feasibility are worth further evaluation. Second,
the portfolios are ranked based on their consequences and the preferences of the
decision makers using either a multi-attribute value or utility function. Third,
a natural language report explaining the ranking is produced to help the decision
makers gain insight into the decision problem and refine the decision parameters.
An intelligent decision system has been developed to demonstrate the feasibility
of the framework.
PMID- 10677669
TI - Supporting decision makers in land use planning around chemical sites. Case
study: expansion of an oil refinery.
AB - An approach for supporting decisions on land use around chemical sites - along
with a software decision support system (DSS) - based on multi-criteria decision
analysis (MCDA; and particularly on the establishment of the set of efficient
solutions and letting the final selection depend on local procedures and value
tradeoffs) is being illustrated through a case study where five alternative
expansions of a refinery are considered along with the existing situation.
Alternative land use plans are based on combinations of alternative uses of
specific land cells coupled with alternative expansion options. Criteria for
evaluating alternative land use plans are the potential loss of life (PLL), the
noise levels and the economic benefit resulting for each specific land use plan.
PMID- 10677670
TI - Risk informed resource allocation policy: safety can save costs.
AB - During economic doldrums, decision making on investments for safety is even more
difficult than it already is when funds are abundant. This paper attempts to
offer some guidance. After stating the present challenge to prevention of losses
in the process industries, the systematic approach of quantified risk assessment
is briefly reviewed and improvements in the methodology are mentioned. In
addition, attention is given to the use of a risk matrix to survey a plant and to
derive a plan of action. Subsequently, the reduction of risk is reviewed.
Measures for prevention, protection, and mitigation are discussed. The
organization of safety has become at least as important as technical safety of
equipment and standards. It is reflected in the introduction of a safety
management system. Furthermore, the design process in a pro-active approach is
described and the concept of inherent safety is briefly addressed. The concept of
Layer of Protection Analysis is explained and also the reason why it is relevant
to provide a cost-benefit analysis. Finally, after comments regarding the cost of
accidents, the basics of costing and profitability are summarized and a way is
suggested to apply this approach to risk-reducing measures. An example is
provided on how a selection can be made from a number of alternatives.
PMID- 10677671
TI - Risk of hydrocyanic acid release in the electroplating industry.
AB - This paper suggests assessing the consequences of hydrocyanic acid (HCN) release
into the air by aqueous cyanide solutions in abnormal situations such as the
accidental introduction of an acid, or the insertion of a cyanide in a pickling
bath. It provides a well-defined source model and its resolution by methods
peculiar to mass transport phenomena. The procedure consists of four stages:
calculation of the liquid phase concentration, estimate of the HCN liquid-vapour
equilibrium, determination of the mass transfer coefficient at the liquid-vapour
interface, evaluation of the air concentration of HCN and of the damage
distances. The results show that small baths operating at high temperatures are
the major sources of risk. The building up of lethal air concentrations, on the
other hand, is governed by the values of the mass transfer coefficient, which is
itself determined by the flow dynamics and bath geometry. Concerning the
magnitude of the risk, the fallout for external emergency planning is slight in
all the cases investigated.
PMID- 10677672
TI - Off-site ignition probability of flammable gases.
AB - A key step in the assessment of risk for installations where flammable liquids or
gases are stored is the estimation of ignition probability. A review of current
modelling and data confirmed that ignition probability values used in risk
analyses tend to be based on extrapolation of limited incident data or, in many
cases, on the judgement of those conducting the safety assessment. Existing
models tend to assume that ignition probability is a function of release rate (or
flammable gas cloud size) alone and they do not consider location, density or
type of ignition source. An alternative mathematical framework for calculating
ignition probability is outlined in which the approach used is to model the
distribution of likely ignition sources and to calculate ignition probability by
considering whether the flammable gas cloud will reach these sources. Data are
collated on the properties of ignition sources within three generic land-use
types: industrial, urban and rural. These data are then incorporated into a
working model for ignition probability in a form capable of being implemented
within risk analysis models. The sensitivity of the model results to assumptions
made in deriving the ignition source properties is discussed and the model is
compared with other available ignition probability methods.
PMID- 10677673
TI - Through ARIPAR-GIS the quantified area risk analysis supports land-use planning
activities.
AB - The paper first summarises the main aspects of the ARIPAR methodology whose steps
can be applied to quantify the impact on a territory of major accident risks due
to processing, storing and transporting dangerous substances. Then the
capabilities of the new decision support tool ARIPAR-GIS, implementing the
mentioned procedure, are described, together with its main features and types of
results. These are clearly shown through a short description of the updated
ARIPAR study (reference year 1994), in which the impact of changes due to
industrial and transportation dynamics on the Ravenna territory in Italy were
evaluated. The brief explanation of how results have been used by local
administrations offers the opportunity to discuss about advantages of the
quantitative area risk analysis tool in supporting activities of risk management,
risk control and land-use planning.
PMID- 10677674
TI - PROTEUS, a technical and management model for aquatic risk assessment of
industrial spills.
AB - The assessment of risks to the aquatic environment related to industrial
installations is a priority in environmental pollution control in the
Netherlands. Major accidents to the surface water such as the Sandoz incident,
but also the high number of smaller accidents that occur every year has invoked
the need for an effective method to assess these risks. Two different models have
been used in this field in the Netherlands over several years. These two software
applications, VERIS and RISAM were developed from two different perspectives:
VERIS from the perspective of supplying major accidents related information in
the safety report, RISAM form the perspective of controlling risks for both
smaller and larger facilities that may pollute surface waters through accidents.
Both systems comprised particular strong points: VERIS considers safety
management aspects in the assessment, RISAM considers differences in surface
water vulnerability and involves quantitative probabilities in the assessment. It
was decided to integrate both methods and maintain these strong points in the
resulting method. This paper describes the new integrated risk assessment method
that now has been developed in a concerted effort between the Ministry of
Transport, Public Works and Water Management, the Ministry of Housing, Spatial
Planning and Environment, and the National Institute for Public Health and
Environment. It also describes the essential elements of the computer program
PROTEUS that is based on the new method and that makes the assessment of aquatic
risks for industrial activities an easy task, partly due to the automatic
generation of the assessment report.
PMID- 10677675
TI - Performance-based standards: safety instrumented functions and safety integrity
levels.
AB - This paper discusses two international performance-based standards, ANSI/ISA
S84.01 and IEC d61508 and the requirements they place upon companies that rely on
electrical, electronic and programmable electronic systems to perform safety
functions. Performance-based regulations are also discussed and common safety
elements between the standards and regulations are identified. Several risk
analysis techniques that can be used to comply with the aforementioned
requirements are discussed and a simple example is used to illustrate the use,
advantages and disadvantages of the techniques. The evaluation of safety
integrity level (SIL) of the Safety Instrumented System (SIS) in terms of the
probability to fail to function is outside the scope of this paper.
PMID- 10677676
TI - Risk based methodology for safety improvements in ports.
AB - With the introduction of the Formal Safety Assessment in the International
Maritime Organisation decision making process regarding new regulations, and the
recent tanker disasters resulting in extensive oil pollution, the public and
political pressure to improve safety in ports and the shipping industry has
increased. Considering that some kind of Safety Report (case) regulations related
to marine operations have not been established, and that the ports and shipping
industry are at the onset of safety regimes utilised in other industries, a step
wise methodology for safety improvements in ports has been developed. In the
first step, the hazard identification and the qualitative risk assessment is
carried out to establish hazard barriers which are or should be in place to
prevent hazards from being released; the controls for managing these hazards are
then developed and integrated into the Safety Management System (SMS). In the
second and optional step, the areas of high risk are investigated in detail and
the approach for risk quantification discussed. The use of the quantitative risk
assessment results is illustrated in two examples.
PMID- 10677677
TI - Maintenance-based strategies for environmental risk minimization in the process
industries.
AB - Industry, environmental agencies and the scientific community have all emphasized
the need to include environmental impact considerations next to profitability
objectives in the design phase of modern chemical processes, responding to the
increasing social concern over environmental degradation in the past years. Most
environmental impact assessment and minimization approaches, however, are rather
qualitative, providing general guidelines. In this work, to overcome their
limitations and rigorously represent the defining elements of environmental risk,
i.e. the mechanism of occurrence of unexpected events usually related to
equipment failure and the severity of their consequences, detailed process,
reliability and maintenance characteristics are incorporated within a process
optimization framework. The objective concerns the optimization of overall
process performance defined as a system effectiveness vector characterized by
both the environmental and the profitability functions of the system.
Implementation of the framework on a process example identifies the optimal
combination of process design and operation as well as preventive maintenance
strategies that accomplish the conflicting environmental and profitability
targets and quantifies the existing trade-offs between them.
PMID- 10677678
TI - Methodological framework for developing decision support systems (DSS) for
hazardous materials emergency response operations.
AB - The production, storage, and transportation of hazardous materials are processes
of vital economic importance for any advanced and technologically complex
society. Although the production and distribution of hazardous materials is
associated with economic development, there is a significant potential danger to
the natural and social environment in the event of their accidental release, a
fact that prompts for the development and implementation of methods and
techniques that aim to improve hazardous materials risk management decisions. The
objective of this paper is to present a unified framework for developing a
Decision Support System (DSS) for supporting a vital function of risk management,
namely the management of emergency response operations. The proposed framework
recognizes the peculiarities of the hazardous materials decision-making
environment which is characterized by: (i) multiple stakeholders, i.e., persons
and organizations involved in and affected by hazardous materials risk management
decisions; (ii) lack of a formal management structure for monitoring and
controlling in a unified manner all Emergency Response Resources; (iii) lack of
clear distinction and fragmentation of responsibilities of the actors involved in
risk management operations; and (iv) dynamic/real-time decisions, i.e., risk
determinants change over time. The proposed framework was used in order to
develop a DSS for managing emergency response operations for large scale
industrial accidents in Western Attica, Greece.
PMID- 10677679
TI - XRCC1 keeps DNA from getting stranded.
PMID- 10677680
TI - UV lesions located on the leading strand inhibit DNA replication but do not
inhibit SV40 T-antigen helicase activity.
AB - DNA replication in eucaryotic cells involves a variety of proteins which
synthesize the leading and lagging strands in an asymmetric coordinated manner.
To analyse the effect of this asymmetry on the translesion synthesis of UV
induced lesions, we have incubated SV40 origin-containing plasmids with a unique
site-specific cis, syn-cyclobutane dimer or a pyrimidine-pyrimidone (6-4)
photoproduct on either the leading or lagging strand template with DNA
replication-competent extracts made from human HeLa cells. Two dimensional
agarose gel electrophoresis analyses revealed a strong blockage of fork
progression only when the UV lesion is located on the leading strand template.
Because DNA helicases are responsible for unwinding duplex DNA ahead of the fork
and are then the first component to encounter any potential lesion, we tested the
effect of these single photoproducts on the unwinding activity of the SV40 T
antigen, the major helicase in our in vitro replication assay. We showed that the
activity of the SV40 T-antigen helicase is not inhibited by UV-induced DNA
lesions in double-stranded DNA substrate.
PMID- 10677681
TI - Cellular and molecular effects of bleomycin are modulated by heat shock in
Saccharomyces cerevisiae.
AB - To study some mechanisms underlying the stress responses in eukaryotic cells, we
investigated the effect of heat shock (HS) on the induction of DNA double strand
breaks as well as on potentially lethal and mutagenic events induced by the
radiomimetic antibiotic bleomycin (BLM) in Saccharomyces cerevisiae. Haploid wild
type yeast cells in the logarithmic phase of growth were exposed to different
concentrations of BLM (0-30 microg/ml, 1.5 h) without and with a previous HS (38
degrees C, 1 h). Immediately after treatments, survival as well as mutation
frequency were determined, and quantitative analysis of chromosomal DNA by laser
densitometry were performed both immediately after treatments and after
incubation of cells during different time intervals in liquid nutrient medium
free of BLM. Our results indicate that HS induces resistance to potentially
lethal and mutagenic effects of BLM. Quantitative analysis of chromosomal DNA
performed immediately after treatments showed the same DNA fragmentation, either
upon BLM as single agent or preceded by HS. However, HS pretreated cells
incubated during 4 h in liquid nutrient medium free of BLM repaired DNA double
strand breaks more efficiently as compared to non-pretreated cells. On this
basis, we propose that the observed HS-induced resistance to BLM depends on a
regulatory network acting after DNA-induced damage, which includes genes involved
in DNA repair, HS response and DNA metabolism.
PMID- 10677683
TI - Mitotic viability and metabolic competence in UV-irradiated yeast cells.
AB - Colony formation is the classic method for measuring survival of yeast cells.
This method measures mitotic viability and can underestimate the fraction of
cells capable of carrying out other DNA processing events. Here, we report an
alternative method, based on cell metabolism, to determine the fraction of
surviving cells after ultraviolet (UV) irradiation. The reduction of 2,3,5
triphenyl tetrazolium chloride (or TTC) to formazan in mitochondria was compared
with cell colony formation and DNA repair capacity in wt cells and two repair
deficient strains (rad1Delta and rad7Delta). Both TTC reduction and cell colony
formation gave a linear response with different ratios of mitotically viable
cells and heat-inactivated cells. However, monitoring the formation of formazan
in non-dividing yeast cells that are partially (rad7Delta) or totally (wt)
proficient at DNA repair is a more accurate measure of cell survival after UV
irradiation. Before repair of UV photoproducts (cis-syn cyclobutane pyrimidine
dimers or CPDs) is complete, these two assays give very different results,
implying that many damaged cells are metabolically competent but cannot
replicate. For example, only 25% of the rad7Delta cells are mitotically viable
after a UV dose of 12 J/m(2)75% of these cells are metabolically competent and
remove over 55% of the CPDs from their genomic DNA. Moreover, repair of CPDs in
wt cells dramatically decreases after the first few hours of liquid holding
(L.H.; incubation in water) and correlates with a substantial decrease in cell
metabolism over the same time period. In contrast, cell colony formation may be
the more accurate indicator of cell survival after UV irradiation of rad1Delta
cells (i.e., cells with little DNA repair activity). These results indicate that
the metabolic competence of UV-irradiated, non-dividing yeast cells is a much
better indicator of cell survival than mitotic viability in partially (or
totally) repair proficient yeast cultures.
PMID- 10677682
TI - AP lyases and dRPases: commonality of mechanism.
AB - Enzymes that release 5'-deoxyribose-5-phosphate (dRP) residues from preincised
apurinic/apyrimidinic (AP) DNA have been collectively termed DNA
deoxyribophosphodiesterases (dRPases), but they fall into two distinct
categories: the hydrolytic dRPases and AP lyases. In order to resolve a number of
conflicting reports in the dRPase literature, we examined two putative hydrolytic
dRPases (Escherichia coli exonuclease I (exo I) and RecJ) and four AP lyases (E.
coli 2, 6-dihydroxy-5N-formamidopyrimidine (Fapy) DNA glycosylase (Fpg) and
endonuclease III (endo III), bacteriophage T4 endonuclease V (endo V), and rat
polymerase beta (beta-pol)) for their abilities to (i) excise dRP from preincised
AP DNA and (ii) incise AP DNA. Although exo I and RecJ exhibited robust 3' to 5'
and 5' to 3' exonucleolytic activities, respectively, on appropriate substrates,
they failed to demonstrate detectable dRPase activity. All four AP lyases
possessed both dRPase and traditional AP lyase activities, albeit to varying
degrees. Moreover, as best illustrated with Fpg, AP lyase enzymes could be
trapped on both preincised and unincised AP DNA using NaBH(4) as the reducing
agent. These results further support the assertion that the catalytic mechanism
of the AP lyases, the beta-elimination reaction, does proceed through an imine
enzyme-DNA intermediate and that the active site residues responsible for dRP
release must contain primary amines. Further, these data indicate a biological
significance for the beta-elimination reaction of DNA glycosylase/AP lyases in
that they, in concert with hydrolytic AP endonucleases, can create appropriate
gapped substrates for short patch base excision repair (BER) synthesis to occur
efficiently.
PMID- 10677684
TI - Overexpression of bacterial RecA protein stimulates homologous recombination in
somatic mammalian cells.
AB - The pairing of homologous molecules and strand exchange is a key event in
homologous recombination promoted by RecA protein in Escherichia coli. Structural
homologs of RecA are widely distributed in eukaryotes including mouse and man. As
has been shown, human HsRad51 protein is not only structural but also functional
homolog of RecA. The question arises whether the bacterial functional homolog of
Rad51 can function in mammalian cells and increase the frequency of the
homologous recombination. To investigate possible effects of bacterial RecA
protein on the frequency of homologous recombination in mammalian cells, the E.
coli RecA protein fused with a nuclear location signal from the large T antigen
of simian virus 40 was overexpressed in the mouse F9 teratocarcinoma cells. We
found that the frequency of gene targeting at the hprt locus was 10-fold
increased in the mouse cells expressing the nucleus-targeted RecA protein.
Southern blot analysis of individual clones that were generated by targeting
recombination revealed predicted type of alterations in hprt gene. The data
indicate that the bacterial nucleus-targeted RecA protein can stimulate
homologous recombination in mammalian cells.
PMID- 10677685
TI - Chronic lymphocytic leukemia lymphocytes lack the capacity to repair UVC-induced
lesions.
AB - Cells from chronic lymphocytic leukemia (CLL) patients and from healthy
individuals were irradiated with UVC and incubated for varying periods of time.
The number of single strand breaks and alkali-labile sites was determined by
comet analysis. Unirradiated CLL and healthy cells exhibited no significant
numbers of single strand breaks. The extent of DNA damage was found to increase
with dose for both healthy and CLL cells. However, the CLL cells had much more
extensive DNA fragmentation than healthy cells at each dose. Deoxyribonucleoside
supplemented medium inhibited comet formation in both cell types. Thymidine alone
produced the same effect. In healthy cells, repair of lesions was complete after
4 h of incubation as indicated by the absence of comet formation. The CLL cells
exhibited no significant repair even after 48 h. CLL lymphocytes are killed by
very low doses of UVC radiation. The results reported here suggest that this
hypersensitivity results from the inability of CLL cells to repair UVC-induced
DNA damage and a contributing factor is the low amounts of intracellular
deoxyribonucleosides.
PMID- 10677686
TI - Dominant sensitization variants of human O(6)-methylguanine-DNA-methyltransferase
obtained by a mutational screen of surface residues.
AB - A scanning mutagenesis experiment was performed on human O(6)-methylguanine
methyltransferase (hMGMT), directed largely at non-conserved surface residues
that have not previously been studied. Variants typically contained two or more
substitutions. Two of the 16 variants characterized in detail are inactive for
methyltransfer, but increase the cytotoxicity and mutagenic effects of
methylating agents. This phenotype is reminiscent of a variant (C145A) that has a
mutation in the methyl-accepting cysteine. C145A is inactive, but reportedly
binds methylated DNA and confers sensitivity to methylating agents. The
sensitization phenotype of the two new variants is more striking in strains that
are wild-type for DNA repair than in strains that are deficient for repair,
suggesting that these proteins inhibit functional DNA repair proteins by
competitively binding to methylated DNA. Both variants have multiple
substitutions in the last helix of the protein. These results suggest that the C
terminal helix is necessary for methyltransfer activity, but not for
methylguanine-specific binding.
PMID- 10677687
TI - Foreword
PMID- 10677688
TI - Chagas disease, from discovery to control - and beyond: history, myths and
lessons to take home.
PMID- 10677689
TI - A short review on the morphology of Trypanosoma cruzi: from 1909 to 1999.
AB - The morphology of Trypanosoma cruzi is reviewed since the initial description of
Giemsa-stained preparations by Carlos Chagas until the most recent micrographs
obtained with freeze-fracture techniques. Special emphasis is given to structures
such as the cell surface, the flagellum, the kinetoplast, the reservosomes and
the endocytic pathway, and the acidocalcisomes.
PMID- 10677690
TI - Relevant glycoconjugates on the surface of Trypanosoma cruzi.
PMID- 10677691
TI - A role for extracellular amastigotes in the immunopathology of Chagas disease.
AB - In spite of the growing knowledge obtained about immune control of Trypanosoma
cruzi infection, the mechanisms responsible for the variable clinico-pathological
expression of Chagas disease remain unknown. In a twist from previous concepts,
recent studies indicated that tissue parasitism is a pre-requisite for the
development of chronic myocarditis. This fundamental concept, together with the
realization that T. cruzi organisms consist of genetically heterogeneous clones,
offers a new framework for studies of molecular pathogenesis. In the present
article, we will discuss in general terms the possible implications of genetic
variability of T. cruzi antigens and proteases to immunopathology. Peptide
epitopes from a highly polymorphic subfamily of trans-sialidase (TS) antigens
were recently identified as targets of killer T cell (CTL) responses, both in
mice and humans. While some class I MHC restricted CTL recognize epitopes derived
from amastigote-specific TS-related antigens (TSRA), others are targeted to
peptide epitopes originating from trypomastigote-specific TSRA. A mechanistic
hypothesis is proposed to explain how the functional activity and specificity of
class I MHC restricted killer T cells may control the extent to which tissue are
exposed to prematurely released amastigotes. Chronic immunopathology may be
exacerbated due the progressive accumulation of amastigote-derived antigens and
pro-inflammatory molecules (eg. GPI-mucins and kinin-releasing proteases) in dead
macrophage bodies.
PMID- 10677692
TI - The population structure of Trypanosoma cruzi: expanded analysis of 54 strains
using eight polymorphic CA-repeat microsatellites.
AB - Recently we cloned and sequenced the first eight Trypanosoma cruzi polymorphic
microsatellite loci and studied 31 clones and strains to obtain valuable
information about the population structure of the parasite. We have now studied
23 further strains, increasing from 11 to 31 the number of strains obtained from
patients with chronic Chagas disease. This expanded set of 54 strains and clones
analyzed with the eight microsatellites markers confirmed the previously observed
diploidy, clonal population organization and very high polymorphism of T. cruzi.
Moreover, this new study disclosed two new features of the population genetic
structure of T. cruzi. The first was the discovery that, similarly to what we had
previously shown for strains isolated from insect vectors, mammals and humans
with acute disease, isolates from patients in the chronic phase of Chagas disease
could also be multiclonal, albeit at a reduced proportion. Second, when we used
parsimony to display the genetic relationship among the clonal lineages in an
unrooted Wagner network we observed, like before, a good correlation of the tree
topography with the classification in three clusters on the basis of single locus
analysis of the ribosomal RNA genes. However, a significant new finding was that
now the strains belonging to cluster 2 split in two distant sub-clusters. This
observation suggests that the evolutionary history of T. cruzi may be more
complex than we previously thought.
PMID- 10677693
TI - Immunopathology of Chagas disease.
AB - The main clinical forms of Chagas disease (acute, indeterminate and chronic
cardiac) present strong evidences for the participation of the immune system on
pathogenesis. Although parasite multiplication is evident during acute infection,
the intense acute myocarditis of this phase exhibits clear ultrastructural signs
of cell-mediated immune damage, inflicted to parasitized and non-parasitized
myocardiocytes and to the endothelium of myocardial capillaries
(microangiopathy). Inflammation subsides almost completely when immunity
decreases parasite load and suppressor factors modulate host reaction, but
inflammation does not disappear when the disease enters the indeterminate phase.
Inflammation becomes mild and focal and undergoes cyclic changes leading to
complete resolution. However, the process is maintained because the disappearance
of old focal lesions is balanced by the upsurge of new ones. This equilibrium
allows for prolonged host survival in the absence of symptoms or signs of
disease. The chronic cardiac form is represented by a delayed-type, cell-mediated
diffuse myocarditis, that probably ensues when the suppressive mechanisms,
operative during the indeterminate phase, become defaulted. The mechanism
responsible for the transition from the indeterminate to the cardiac form, is
poorly understood.
PMID- 10677694
TI - Evolution of the clinical and epidemiological knowledge about Chagas disease 90
years after its discovery.
AB - Three different periods may be considered in the evolution of knowledge about the
clinical and epidemiological aspects of Chagas disease since its discovery: (a)
early period concerning the studies carried out by Carlos Chagas in Lassance with
the collaboration of other investigators of the Manguinhos School. At that time
the disease was described and the parasite, transmitters and reservoirs were
studied. The coexistence of endemic goiter in the same region generated some
confusion about the clinical forms of the disease; (b) second period involving
uncertainty and the description of isolated cases, which lasted until the 1940
decade. Many acute cases were described during this period and the disease was
recognized in many Latin American countries. Particularly important were the
studies of the Argentine Mission of Regional Pathology Studies, which culminated
with the description of the Romana sign in the 1930 decade, facilitating the
diagnosis of the early phase of the disease. However, the chronic phase, which
was the most important, continued to be difficult to recognize; (c) period of
consolidation of knowledge and recognition of the importance of Chagas disease.
Studies conducted by Laranja, Dias and Nobrega in Bambui updated the description
of Chagas heart disease made by Carlos Chagas and Eurico Villela. From then on,
the disease was more easily recognized, especially with the emphasis on the use
of a serologic diagnosis; (d) period of enlargement of knowledges on the disease.
The studies on denervation conducted in Ribeirao Preto by Fritz Koberle starting
in the 1950 decade led to a better understanding of the relations between Chagas
disease and megaesophagus and other visceral megas detected in endemic areas.
PMID- 10677695
TI - [Evolution of the knowledge about Chagas disease vectors 90 years after its
discovery].
PMID- 10677696
TI - Prevention of transfusional Trypanosoma cruzi infection in Latin America.
AB - Trypanosoma cruzi is a protozoan infection widely spread in Latin America, from
Mexico in the north to Argentina and Chile in the south. The second most
important way of acquiring the infection is by blood transfusion. Even if most
countries of Latin America have law/decree/norms, that make mandatory the
screening of blood donors for infectious diseases, including T. cruzi (El
Salvador and Nicaragua do not have laws on the subject), there is usually no
enforcement or it is very lax. Analysis of published serologic surveys of T.
cruzi antibodies in blood donors done in 1993, indicating the number of donors
and screening coverage for T. cruzi in ten countries of Central and South America
indicated that the probability of receiving a potentially infected transfusion
unit in each country varied from 1,096 per 10,000 transfusions in Bolivia, the
highest, to 13.02 or 13.86 per 10,000 transfusions in Honduras and Venezuela
respectively, where screening coverage was 100%. On the other hand the
probability of transmitting a T. cruzi infected unit was 219/10,000 in Bolivia,
24/10,000 in Colombia, 17/10,000 in El Salvador, and around 2-12/10,000 for the
seven other countries. Infectivity risks defined as the likelihood of being
infected when receiving an infected transfusion unit were assumed to be 20% for
T. cruzi. Based on this, estimates of the absolute number of infections induced
by transfusion indicated that they were 832, 236, and 875 in Bolivia, Chile and
Colombia respectively. In all the other countries varied from seven in Honduras
to 85 in El Salvador. Since 1993, the situation has improved. At that time only
Honduras and Venezuela screened 100% of donors, while seven countries, Argentina,
Colombia, El Salvador, Honduras, Paraguay, Uruguay and Venezuela, did the same in
1996. In Central America, without information from Guatemala, the screening of
donors for T. cruzi prevented the transfusion of 1,481 infected units and the
potential infection of 300 individuals in 1996. In the same year, in seven
countries of South America, the screening prevented the transfusion of 36,017
infected units and 7, 201 potential cases of transfusional infection.
PMID- 10677697
TI - The evolution of Chagas disease (American trypanosomiasis) control after 90 years
since Carlos Chagas discovery.
PMID- 10677698
TI - The noble enigma: Chagas' nominations for the Nobel prize.
AB - Carlos Chagas, a Brazilian physician, discovered the American trypanosomiasis in
1909. Like other remarkable discoveries of those days, his work helped to
articulate the insect-vector theory and other theoretical guidelines in tropical
medicine. Unlike all other discoveries, all the stages of this work were
accomplished in a few months and by a single man. Chagas' discovery was widely
recognized at home and abroad. He was twice nominated for the Nobel Prize - in
1913 and in 1921-, but never received the award. Evidence suggests that the
reasons for this failure are related to the violent opposition that Chagas faced
in Brazil. The contentions towards Chagas were related to a rejection of the
meritocratic procedures that gave him prominence, as well as to local petty
politics.
PMID- 10677699
TI - Biology and ultra-structure of Trypanosoma cruzi: a 90-year old challenge for
scientists.
PMID- 10677700
TI - Features of host cell invasion by different infective forms of Trypanosoma cruzi.
AB - Through its life cycle from the insect vector to mammalian hosts Trypanosoma
cruzi has developed clever strategies to reach the intracellular milieu where it
grows sheltered from the hosts' immune system. We have been interested in several
aspects of in vitro interactions of different infective forms of the parasite
with cultured mammalian cells. We have observed that not only the classically
infective trypomastigotes but also amastigotes, originated from the extracellular
differentiation of trypomastigotes, can infect cultured cells. Interestingly, the
process of invasion of different parasite infective forms is remarkably distinct
and also highly dependent on the host cell type.
PMID- 10677701
TI - The reservosome of Trypanosoma cruzi epimastigotes: an organelle of the endocytic
pathway with a role on metacyclogenesis.
PMID- 10677702
TI - Internalization of components of the host cell plasma membrane during infection
by Trypanosoma cruzi.
AB - Epimastigote and trypomastigote forms of Trypanosoma cruzi attach to the
macrophage surface and are internalized with the formation of a membrane bounded
vacuole, known as the parasitophorous vacuole (PV). In order to determine if
components of the host cell membrane are internalized during formation of the PV
we labeled the macrophage surface with fluorescent probes for proteins, lipids
and sialic acid residues and then allowed the labeled cells to interact with the
parasites. The interaction process was interrupted after 1 hr at 37 masculineC
and the distribution of the probes analyzed by confocal laser scanning
microscopy. During attachment of the parasites to the macrophage surface an
intense labeling of the attachment regions was observed. Subsequently labeling of
the membrane lining the parasitophorous vacuole containing epimastigote and
trypomastigote forms was seen. Labeling was not uniform, with regions of intense
and light or no labeling. The results obtained show that host cell membrane
lipids, proteins and sialoglycoconjugates contribute to the formation of the
membrane lining the PV containing epimastigote and trypomastigote T. cruzi forms.
Lysosomes of the host cell may participate in the process of PV membrane
formation.
PMID- 10677703
TI - Trypanosoma cruzi-cardiomyocytes: new contributions regarding a better
understanding of this interaction.
AB - The present paper summarizes new approaches regarding the progress done to the
understanding of the interaction of Trypanosoma cruzi-cardiomyocytes. Mannose
receptors localized at the surface of heart muscle cell are involved in binding
and uptake of the parasite. One of the most striking events in the parasite-heart
muscle cells interaction is the disruption of the actin cytoskeleton. We have
investigated the regulation of the actin mRNA during the cytopathology induced in
myocardial cells by the parasite. T. cruzi invasion increases calcium resting
levels in cardiomyocytes. We have previously shown that Ca2+ ATPase of the
sarcoplasmic reticulum (SERCA) is involved in the invasion of T. cruzi in
cardiomyocytes. Treating the cells with thapsigargin, a drug that binds to all
SERCA ATPases and causes depletion of intracellular calcium stores, we found a
75% inhibition in the T. cruzi-cardiomyocytes invasion.
PMID- 10677704
TI - Why studies on invasion of host cell by Trypanosoma cruzi using established cell
lines or primary cell cultures give conflicting results?
PMID- 10677705
TI - Recent issues of the biochemistry and molecular biology of Trypanosoma cruzi.
PMID- 10677706
TI - Epidemiology, biochemistry and evolution of Trypanosoma cruzi lineages based on
ribosomal RNA sequences.
PMID- 10677707
TI - Differential gene expression during Trypanosoma cruzi metacyclogenesis.
AB - The transformation of epimastigotes into metacyclic trypomastigotes involves
changes in the pattern of expressed genes, resulting in important morphological
and functional differences between these developmental forms of Trypanosoma
cruzi. In order to identify and characterize genes involved in triggering the
metacyclogenesis process and in conferring to metacyclic trypomastigotes their
stage specific biological properties, we have developed a method allowing the
isolation of genes specifically expressed when comparing two close related cell
populations (representation of differential expression or RDE). The method is
based on the PCR amplification of gene sequences selected by hybridizing and
subtracting the populations in such a way that after some cycles of hybridization
amplification genes specific to a given population are highly enriched. The use
of this method in the analysis of differential gene expression during T. cruzi
metacyclogenesis (6 hr and 24 hr of differentiation and metacyclic
trypomastigotes) resulted in the isolation of several clones from each time
point. Northern blot analysis showed that some genes are transiently expressed (6
hr and 24 hr differentiating cells), while others are present in differentiating
cells and in metacyclic trypomastigotes. Nucleotide sequencing of six clones
characterized so far showed that they do not display any homology to gene
sequences available in the GeneBank.
PMID- 10677708
TI - Organization and expression of a multigene family encoding the surface
glycoproteins of Trypanosoma cruzi metacyclic trypomastigotes involved in the
cell invasion.
PMID- 10677709
TI - Trypanosoma cruzi mucins: potential functions of a complex structure.
PMID- 10677710
TI - Characterization of Trypanosoma cruzi.
PMID- 10677711
TI - Taxonomy of Trypanosoma cruzi: a commentary on characterization and nomenclature.
PMID- 10677712
TI - Trypanosoma cruzi: clonal structure of parasite strains and the importance of
principal clones.
PMID- 10677713
TI - Genetic diversity and genetic exchange in Trypanosoma cruzi: dual drug-resistant
"progeny" from episomal transformants.
AB - Extensive characterisation of Trypanosoma cruzi by isoenzyme phenotypes has
separated the species into three principal zymodeme groups, Z1, Z2 and Z3, and
into many individual zymodemes. There is marked diversity within Z2. A strong
correlation has been demonstrated between the strain clusters determined by
isoenzymes and those obtained using random amplified polymorphic DNA (RAPD)
profiles. Polymorphisms in ribosomal RNA genes, in mini-exon genes, and
microsatellite fingerprinting indicate the presence of at least two principal T.
cruzi genetic lineages. Lineage 1 appears to correspond with Z2 and lineage 2
with Z1. Z1 (lineage 2) is associated with Didelphis. Z2 (lineage 1) may be
associated with a primate host. Departures from Hardy-Weinberg equilibrium and
linkage disequilibrium indicate that propagation of T. cruzi is predominantly
clonal. Nevertheless, two studies show putative homozygotes and heterozygotes
circulating sympatrically: the allozyme frequencies for phosphoglucomutase, and
hybrid RAPD profiles suggest that genetic exchange may be a current phenomenon in
some T. cruzi transmission cycles. We were able to isolate dual drug-resistant T.
cruzi biological clones following copassage of putative parents carrying single
episomal drug-resistant markers. A multiplex PCR confirmed that dual drug
resistant clones carried both episomal plasmids. Preliminary karyotype analysis
suggests that recombination may not be confined to the extranuclear genome.
PMID- 10677714
TI - Populational heterogeneity of Brazilian Trypanosoma cruzi isolates revealed by
the mini-exon and ribosomal spacers.
PMID- 10677715
TI - Reflections on the population dynamics of Trypanosoma cruzi: heterogeneity versus
plasticity.
PMID- 10677716
TI - The sylvatic cycle of Trypanosoma cruzi: a still unsolved puzzle.
PMID- 10677717
TI - Morphobiological characterization of Trypanosoma cruzi Chagas, 1909 and its
distinction from other trypanosomes.
PMID- 10677718
TI - Trypanosoma cruzi - vector-vertebrate hosts interactions.
PMID- 10677719
TI - Biological factors involving Trypanosoma cruzi life cycle in the invertebrate
vector, Rhodnius prolixus.
PMID- 10677720
TI - Some morphological and molecular aspects of the life cycle of Trypansoma cruzi in
the insect vector.
PMID- 10677721
TI - Immunity in Rhodnius prolixus: trypanosomatid-vector interactions.
PMID- 10677722
TI - Triatominae as a model of morphological plasticity under ecological pressure.
AB - The use of biochemical and genetic characters to explore species or population
relationships has been applied to taxonomic questions since the 60s. In
responding to the central question of the evolutionary history of Triatominae,
i.e. their monophyletic or polyphyletic origin, two important questions arise (i)
to what extent is the morphologically-based classification valid for assessing
phylogenetic relationships? and (ii) what are the main mechanisms underlying
speciation in Triatominae? Phenetic and genetic studies so far developed suggest
that speciation in Triatominae may be a rapid process mainly driven by ecological
factors.
PMID- 10677724
TI - The synanthropic process of Chagas disease vectors in Brazil, with special
attention to Triatoma brasiliensis Neiva, 1911 (Hemiptera, reduviidae,
triatominae) population, genetical, ecological, and epidemiological aspects.
PMID- 10677723
TI - Mitochondrial DNA variation of Triatoma infestans populations and its implication
on the specific status of T. melanosoma.
AB - DNA sequence comparison of 412 base-pairs fragments of the mitochondrial
cytochrome B gene was used to infer the genetic structure of nine geographical
Triatoma infestans populations and their phylogenetic relationship with T.
melanosoma and T. brasiliensis. T. infestans and T. melanosoma were compared by
morphometry, allozyme and cytogenetic analyses, as well as subjected to
reciprocal crosses, in order to clarify the taxonomic status of the latter. No
differences were found to distinguish the two species and the crosses between
them yielded progeny. T. infestans populations presented four haplotypes that
could be separated in two clusters: one formed by the samples from Bolivia (Andes
and Chaco) and the other formed by samples from Argentina and Brazil. Silvatic
and domestic T. infestans populations from Bolivia (Andes) were genetically
identical.
PMID- 10677725
TI - Trypanosoma cruzi interaction with its vectors and vertebrate hosts.
PMID- 10677726
TI - Immunopathology of Chagas disease - a historical overview.
PMID- 10677727
TI - Integration of Trypanosoma cruzi kDNA minicircle sequence in the host genome may
be associated with autoimmune serum factors in Chagas disease patients.
AB - Integration of kDNA sequences within the genome of the host cell shown by PCR
amplification with primers to the conserved Trypanosoma cruzi kDNA minicircle
sequence was confirmed by Southern hybridization with specific probes. The cells
containing the integrated kDNA sequences were then perpetuated as transfected
macrophage subclonal lines. The kDNA transfected macrophages expressed membrane
antigens that were recognized by antibodies in a panel of sera from ten patients
with chronic Chagas disease. These antigens barely expressed in the membrane of
uninfected, control macrophage clonal lines were recognized neither by factors in
the control, non-chagasic subjects nor in the chagasic sera. This finding
suggests the presence of an autoimmune antibody in the chagasic sera that
recognizes auto-antigens in the membrane of T. cruzi kDNA transfected macrophage
subclonal lines.
PMID- 10677728
TI - The role of the immune response on the development of severe clinical forms of
human Chagas disease.
PMID- 10677729
TI - Immunopathology of cardiomyopathy in the experimental Chagas disease.
AB - The mechanisms by which Trypanosoma cruzi causes cardiomyopathy and induces
neuronal destruction are discussed in this paper. The results suggest that
autoimmunity in the chronic phase is the main cause of the progressive cardiac
destruction, and that autoreactivity is restricted to the CD4+ T cell
compartment. During the acute phase, the neuronal and cardiac fiber destruction
occurs when ruptured parasite nests release T. cruzi antigens that bind to the
cell surface in the vicinity which become targets for the cellular and humoral
immune response against T. cruzi. The various factors involved in the genesis of
autoimmunity in chronic T. cruzi infection include molecular mimicry,
presentation of self-antigens and imbalance of immune regulation.
PMID- 10677730
TI - Human chronic chagasic cardiopathy: participation of parasite antigens, subsets
of lymphocytes, cytokines and microvascular abnormalities.
AB - This article tries to demonstrate by new pathological findings (with the use of
immunohistochemical technique and confocal laser microscopy) that chronic
chagasic cardiomyopathy is a result of multiple factors involving myocarditis,
immunodepression, severe fibrosis and microvessels dilatation and that all of
these alterations are probably directly related with the presence of Trypanosoma
cruzi parasites in the host associated with inadequate immunological response of
the host.
PMID- 10677731
TI - Mouse as a model for Chagas disease: does mouse represent a good model for Chagas
disease?
PMID- 10677732
TI - Immunosuppressive drugs as a tool to explore immunopathology in experimental
Chagas disease.
PMID- 10677733
TI - Evolution on the immunopathology of Chagas disease.
PMID- 10677734
TI - The role of tissue-infiltrating T cells in immunopathology of Chagas disease.
PMID- 10677735
TI - Development in the etiologic diagnosis of Chagas disease.
PMID- 10677736
TI - Evolution of knowledge on the etiological diagnosis of chagasic infection.
PMID- 10677737
TI - Serological diagnosis of Chagas disease with purified and defined Trypanosoma
cruzi antigens.
PMID- 10677738
TI - Xenodiagnosis.
PMID- 10677739
TI - Changes in the hemoculture methodology improve the test positivity.
PMID- 10677740
TI - Chagas disease diagnosis using polymerase chain reaction, hemoculture and
serologic methods.
PMID- 10677741
TI - Diagnosis of Trypanosoma cruzi chronic infections in humans: usefulness of the
complement regulatory protein antigens and lytic antibodies in the control of
cure.
PMID- 10677742
TI - Polymerase chain reaction detection: new insights into the diagnosis of chronic
Chagas disease.
PMID- 10677743
TI - Screening and confirmation in chagas disease serology - a contribution.
PMID- 10677744
TI - Clinical evolution and morbi-mortality in Chagas disease.
PMID- 10677745
TI - Indeterminate form of Chagas disease.
PMID- 10677746
TI - Risk of death due to chronic chagasic cardiopathy.
AB - In this longitudinal study 5,710 people were included. The inclusion criteria
were two positive serological results for Trypanosoma cruzi infection, 15 and 50
years old and no other demonstrable disease at the time of study. In the five
year follow up 1,117 patients were lost. The follow up involved yearly evaluation
of serology, clinical examination, X-ray of thorax, and ECG, for 4,593 patients
and 263 were contacted at home because they did not assist for their clinical
consultant. Time average of follow up was 5.3 years. Eighty nine (1.5%) of the
4,593 patients died during the follow-up period, 63 (71%) by cardiac
insufficiency (CI) and 26 (29%) by severe ventricular arrhythmias. Diagnosis of
cardiomegaly was present in all the patients with diagnosis of CI and in 15 (5%)
of the patients with diagnosis of arrhythmias. The ECG alterations of these
patients show 61 right bundle branch block (RBBB), associated or not with left
anterior hemiblock (LAHB), 47 pathological Q wave and 70 primary repolarization
alterations; 61 had polyfocal ventricular arrhythmia. The death rate was similar
in the sexes and was more frequent between 40 and 50 years of age. Information on
1,380 recuperated patients shows that 15 died with no previous symptoms and
without medical assistance and were interpreted as sudden death. The latest ECG
in three follow-up of these patients indicates (before death) that only one had
normal study and 14 presented 12 RBBB; 9 LAHB; 7 isolated ventricular arrhythmia;
10 repolarize alterations; 2 pathological Q wave, 10 patients of them with RBBB
and repolarize alterations. In all the cases we had people between 35 and 43
years old, 9 men and 6 women. This study shows that in Chagas disease is possible
to differentiate two risk groups. A low risk death group that have normal ECG and
clinical evaluation during the follow up, and a high risk group associate ECG
with RBBB and primary alterations of repolarization and/or inactivation zones
with not annual clinical evaluation.
PMID- 10677747
TI - Sudden death in patients with Chagas disease.
PMID- 10677748
TI - Chagas disease and immunosuppression.
PMID- 10677749
TI - Longitudinal radiological study of the esophagus in Chagas disease.
PMID- 10677750
TI - Criteria of Chagas disease cure.
PMID- 10677751
TI - Etiological treatment for infection by Trypanosoma cruzi.
PMID- 10677752
TI - Clinical treatment of the digestive form of Chagas disease.
PMID- 10677753
TI - Chagas disease surgery.
PMID- 10677754
TI - Parasitological cure of Chagas disease: is it possible? Is it relevant?
PMID- 10677755
TI - Chagas disease: criteria of cure and prognosis.
PMID- 10677756
TI - Treatment of Trypanosoma cruzi infection in the undetermined phase. Experience
and current guidelines of treatment in Argentina.
PMID- 10677757
TI - Climatic factors related to Chagas disease transmission.
PMID- 10677758
TI - Genetic variability in Brazilian triatomines and the risk of domiciliation.
PMID- 10677759
TI - The process of domestication in Triatominae.
PMID- 10677760
TI - Chagas disease: from bush to huts and houses. Is it the case of the Brazilian
Amazon?
AB - Two of the major problems facing the Amazon - human migration from the other
areas and uncontrolled deforestation - constitute the greatest risk for the
establishment of endemic Chagas disease in this part of Brazil. At least 18
species of triatomines had been found in the Brazilian Amazon, 10 of them
infected with Trypanosoma cruzi, associated with numerous wild reservoirs. With
wide-range deforestation, wild animals will perforce be driven into other areas,
with tendency for triatomines to become adapted to alternative food sources in
peri and intradomicilies. Serological surveys and cross-sectional studies for
Chagas disease, carried out in rural areas of the Rio Negro, in the Brazilian
Amazon, showed a high level of seropositivity for T. cruzi antibodies. A strong
correlation of seroreactivity with the contact of gatherers of piacava fibers
with wild triatomines could be evidenced.
PMID- 10677761
TI - Epidemiology and dynamics of the vectorial transmission of Chagas disease.
PMID- 10677762
TI - Epidemiology of Chagas disease in Ecuador. A brief review.
AB - Chagas disease is a complex public health problem that has been underestimated in
Ecuador. Here we review the relevant published information, and present
unpublished and new data that help to understand the current Chagas disease
epidemiological situation and its evolution in the country. Three main
characteristics have been identified: (i) persistence of Trypanosoma cruzi
transmission in already known foci; (ii) a marked endemicity in some urban areas
of Guayaquil; and (iii) the transformation of new Amazon foci into truly endemic
areas. The situation in other suspect areas remains uncertain. Five Triatominae
species have been implicated in the transmission of T. cruzi to people in Ecuador
(Triatoma dimidiata, Rhodnius ecuadoriensis, R. pictipes, R. robustus and
Panstrongylus geniculatus), but some others may also play a role in some areas
(P. rufotuberculatus, P. howardi, T. carrioni and P. chinai). Other Triatominae
reported seem to have little or no epidemiological relevance (T. venosa, T.
dispar, Eratyrus mucronatus, E. cuspidatus, P. lignarius and Cavernicola pilosa).
High frequency of acute cases and severe chronic disease has been observed.
Although cardiomyopathy is more frequent, serious digestive disease is also
present. It is estimated that around 120,000-200,000 people may be infected. 2.2
to 3.8 million people are estimated to live under transmission risk conditions.
PMID- 10677763
TI - Considerations on the epidemiology and transmission of Chagas disease in the
Brazilian Amazon.
PMID- 10677764
TI - Potential for domestication of Panstrongylus geniculatus (Latreille, 1811)
(Liemiptera, reduviidae, triatominae) in the municipality of Muana, Marajo
island, state of Para, Brazil.
PMID- 10677765
TI - Progress towards interruption of transmission of Chagas disease.
PMID- 10677766
TI - Elimination of vector-borne transmission of Chagas disease.
AB - The control of the vector-borne transmission of Chagas disease in Brazil was
organized as a national program in 1975, when two large entomological and sero
epidemiological surveys were conducted in the country in order to identify areas
at highest risk of transmission and to guide interventions regarding the chemical
treatment of domestic vectors of the disease. The authors present the baseline
data gathered through these studies and compare them with more recent data. The
evaluation performed shows that the transmission by Triatoma infestans is
virtually interrupted and that the transmission by other native species of
triatominae from different regions of the country is possibly very low. It is
emphasized the need to maintain permanent actions of entomological surveillance
in order to prevent recurrent transmission.
PMID- 10677767
TI - Interruption of Chagas disease transmission in the Andean countries: Colombia.
PMID- 10677768
TI - Elimination of the vectorial transmission of Chagas disease in Central American
countries: Honduras.
PMID- 10677769
TI - Chagas infection transmission control: situation of transfusional transmission in
Brazil and other countries of Latin America.
AB - The transmission of the transfusion-associated Chagas disease is an important
mechanism of its dissemination in several Latin American countries. The
transmission risk depends on five factors: prevalence of infection in blood
donors, degree of serological coverage, sensibility of used tests, safety of
obtained results and infection risk. The Southern Cone Iniciative set off by the
Pan-American Health Organization, in 1991, is contributing to the implementation
of blood law in each endemic country, and to reduce the risk of transfusional
transmission of this horrible disease. Despite the clear improvement of Brasilian
hemotherapy after 1980 (with the creation of the Blood National Program - Pro
Sangue) and the significant reduction of the chagasic infection among its blood
donors; socio-economic, politic and cultural unlevels, prevent it from reaching
the necessary universality and security. In order to assure both, the Brazilian
Ministry of Health decided to restructure its blood system. In May, 1998, a great
program was launched, to reach a specific goal: Blood - 100% with quality safety
in all its process until 2003. It was divided in 12 projects, intends to
guarantee the quality and self sufficiency in blood and hemoderivates.
PMID- 10677771
TI - Recommendations from a satellite meeting.
PMID- 10677770
TI - Differences of susceptibility of five triatomine species to pyrethroid
insecticides - implications for Chagas disease vector control.
AB - As pyrethroids are presently the favored group of insecticides to control
triatomines, we performed a series of bioassays to determine the intrinsic
activity of some of the main compounds used in the control campaigns, against
five of the main species of triatomines to be controlled. Comparing the
insecticides it can be seen that lambdacyhalothrin is more effective than the
other three pyrethroids, both considering the LD50 and 99 for all the three
species with comparable results. On Triatoma infestans the LD50 of
lambdacyhalothrin was followed by that of alfacypermethrin, cyfluthrin and
deltamethrin. On Rhodnius prolixus the sequence, in decreasing order of activity,
was lambdacyhalothrin, alfacypermethrin, deltamethrin and cyfluthrin. Some
modifications can be seen when we compare the LD99, that has more to see to what
happens in the field. T. brasiliensis showed to be as sensible to
lambdacyhalothrin as T. infestans, the most susceptible for this product. By the
other side T. sordida is the least susceptible considering the LD99 of this
insecticide.
PMID- 10677772
TI - The Mount Sinai Hospital--a brief history.
AB - In 1852, The Jews Hospital was founded for the increasing number of Jews in New
York. It opened in 1855 with 45 beds on West 28th Street; 92% of the patients
were indigent. In 1864, the hospital formally became nonsectarian and, in 1866,
changed its name to The Mount Sinai Hospital. The medical staff was primarily
Jewish, because until relatively recently, it was difficult for Jewish doctors to
obtain postgraduate training or specialist posts at major New York hospitals. As
the Jewish population moved uptown, so did The Mount Sinai Hospital: in 1870 to
66th Street, and in 1904 to 100th Street, with 456 beds, growing with new
buildings and services to the current 1100 beds, 50,000 discharges, 400,000
inpatient days and 300,000 outpatient visits each year. Services increasingly
became specialized, and then subspecialized. Key innovations included the choice
of interns by competitive examination (1872), an advisory Medical Board (1872),
the Nurse Training School (1881), the library (1883), the Alumni Association
(1896), a professional medical hospital administrator (1903), research
laboratories (1904), clinicopathological conferences (1905), the Social Services
Department (1906), postgraduate teaching programs (1923), full-time chiefs of
clinical services (1944), the dedication of the Mount Sinai School of Medicine
(1968), and the merger in 1998 into the Mount Sinai-New York University Medical
Center.
PMID- 10677773
TI - Gastroenterology and hepatology as subspecialties.
AB - Gastroenterology grew as a subspecialty in Germany in the 19th century. In the
1880s and 1890s, Austrian and German clinics were attended by American physicians
who, on returning to the U.S., founded the American Gastroenterological
Association in 1897. The creation of a subspecialty board, however, had to wait
until 1941. At The Mount Sinai Hospital, Dr. A.A. Berg was appointed Surgeon in
1899. His practice focused on the alimentary tract, which in 1910 became one of
the four surgical specialties. In 1914, further subdivision led to the stomach
and duodenum becoming additional specialties. In 1917, wards were endowed for Dr.
Berg's specialty. The first Mount Sinai physician to have an interest in
gastroenterology was Morris Manges, but the first to limit his practice to
gastroenterology was Dr. Edward Aronson, for whom a specialist outpatient
division was formed in 1913. Aronson died in 1922 and was succeeded by Dr.
Burrill Crohn, who was followed in 1934 by Dr. Asher Winkelstein; all three
collaborated closely with the surgeons, physiologists and biochemists. In 1958,
Dr. Henry Janowitz became chief of the Division of Gastroenterology; he was
succeeded in 1983 by Dr. David Sachar, who was followed in 1999 by his associate
Dr. Steven Itzkowitz. In 1958 Dr. Fenton Schaffner became chief of the Division
of Hepatology (now headed by Dr. Paul Berk), and in 1979 Dr. LeLeiko became chief
of Pediatric Gastroenterology.
PMID- 10677774
TI - Morris Manges and Edmund Aronson.
PMID- 10677775
TI - Burrill B. Crohn (1884-1983).
PMID- 10677776
TI - Asher Winkelstein (1893-1972).
PMID- 10677777
TI - Franklin Hollander (1899-1966).
PMID- 10677778
TI - Gastroenterology and hepatology--the diagnostic data.
AB - The Annual Reports of the Mount Sinai Hospital from the 1850s, and the Mount
Sinai Hospital Reports for 1897-1906, make it possible to trace the discharges of
gastroenterological inpatients, and (for a few years) of outpatients. Fully
computerized diagnostic data have only been available since 1986. In the 19th
century, about 20% of the outpatients had digestive disorders, the commonest of
which were gastralgia/gastritis/dyspepsia, gastroenteritis, oropharyngeal
complaints and constipation. A similar proportion of inpatients had digestive
diagnoses, but the four disorders listed above decreased markedly in the second
half of the 19th century, so that by the turn of the century the commonest
diseases were typhlitis (appendicitis), hemorrhoids and other anal problems. By
the 1990s, digestive diseases accounted for only 5% of total admissions,
hepatobiliary diagnoses being the commonest group. Some cancers such as gastric
and esophageal showed little change, while colorectal increased markedly. Some
newly recognized diseases, such as peptic ulcer, waxed and then waned, while
colitis and regional enteritis came and have continued to increase. Other new
diagnoses, such as autointoxication and visceroptosis, flashed into prominence
and then disappeared totally, presumably because they were nondiseases.
PMID- 10677779
TI - The esophagus.
AB - Original investigations and descriptions of the radiographic findings and
techniques of evaluation of the esophagus and esophagogastric junction were made
at The Mount Sinai Hospital by Drs. Bernard S. Wolf and colleagues in the third
quarter of the 20th century. These included basic descriptions of peptic
ulceration of the esophagus, the gastric lined esophagus, definitions of hiatus
hernia, terminology of the esophagogastric junction, use of the barium pill and
correlations of cineradiology with manometry.
PMID- 10677780
TI - Gastric secretion.
AB - The European gastric test meal was widely used in The Mount Sinai Hospital in the
1890s and early 1900s, but was then abandoned diagnostically after the
introduction of gastroscopy and radiology. The fundamental methodological
advances of Franklin Hollander led to his quantitative formulation of the ionic
concentrations of the gastric acid parietal and nonparietal components, followed
by his insulin test for completeness of vagotomy.
PMID- 10677781
TI - Acid secretion after gastric operations.
AB - In the early 20th century, the commonest surgical treatment of peptic ulcer was
gastroenterostomy. Crohn and Wilensky demonstrated that this operation did not
achieve its aim of markedly reducing gastric acidity or of accelerating motility.
These results were highly controversial, but led to Lewisohn visiting Haberer in
Austria in 1922, and convincing Dr. A.A. Berg to abandon gastroenterostomy and
use partial gastrectomy as the standard ulcer operation, with additional vagotomy
in those patients with duodenal ulcer with high acidity. In 1929, a few patients
were treated by vagotomy and gastrojejunostomy by Dr. Ralph Colp, with
discouraging results. It was only in the 1940s that Mount Sinai surgeons adopted
transthoracic or subdiaphragmatic vagotomy and gastroenterostomy (or later,
pyloroplasty) as their standard, effective acid-lowering treatment of peptic
ulcers.
PMID- 10677782
TI - The gastric mucosal barrier.
AB - Most gastroduodenal ulcer disease results from a weakness in the normal gastric
mucous barrier against the penetration of acid secreted by the stomach. Based on
meticulous and insightful research, the distinguished physiologist Franklin
Hollander hypothesized that the stomach is protected against its own acid
secretion by a dynamic two-component mucus-mucosal barrier. Hollander and his co
workers defined the physical and chemical characteristics of the mucus components
of this barrier, as well as the defense provided by the surface epithelial cell
layer, which he viewed as the second line of defense (the second component).
Barrier investigators at Mount Sinai demonstrated the effects of impairment of
barrier function with resultant increased back-diffusion of acid, and they
defined the consequences of this acid penetration into the gastric epithelium.
The contribution of these workers included important observations on the natural
impermeability of the gastric corpus and fundus as well as the normally increased
permeability of the antrum. They also presented evidence on the role of bile in
duodenogastric reflux in gastric ulcer disease and the presence of impaired
barrier function in patients with gastric ulcer and pernicious anemia. Further
studies included demonstration that stress and carcinogens could disrupt the
gastric mucosal barrier. Disruption of the barrier, in turn, was shown to allow
carcinogenesis to occur by permitting the absorption of certain carcinogens which
otherwise are warded off by the barrier. The Hollander two-component gastric
mucosal barrier hypothesis has, in recent years, been increasingly validated by
experimental data coming from other laboratories.
PMID- 10677783
TI - Peptic ulcer.
AB - Indigestion and heartburn have been described for thousands of years, but it was
only in the 16th century that the disease peptic ulcer was established by
autopsy. At first, only gastric ulcers were identified. In the 18th century,
duodenal ulcers, most of which were fatal cases after perforation or hemorrhage,
were seen. In the 19th century, when autopsy became a common, even routine,
hospital procedure, uncomplicated acute and chronic ulcers were found and then
correlated with symptoms. Thus, our current clinical understanding dates from the
1820s, by which time peptic ulcers were being reported in the U.S. It is unclear
why gastric ulcers were not diagnosed at The Mount Sinai Hospital until 1873 and
duodenal ulcers until 1885. However, after that time both conditions were
diagnosed frequently, and they rapidly became common and were treated medically
and surgically.
PMID- 10677784
TI - Treatments of peptic ulcer.
AB - From the late 19th century, Mount Sinai gastroenterologists declared their
scepticism of the efficacy of all recommended treatments of peptic ulcer, and
looked forward to trials which could distinguish between sequence and
consequence, between association and causation. The rationale of all the early
studies was to reduce gastric acidity, but it soon became clear that any
neutralization by single doses of antacids was brief and ineffective. Winkelstein
s demonstration that patients with duodenal ulcer had higher acidities not only
before and after meals but also through the night hours led him to introduce a
new treatment, the alkalinized intragastric milk drip together with atropine. One
of the earliest controlled clinical trials at Mount Sinai compared different
antacid regimes and showed that pH values above 3.5 were achieved in only about
half of the patients on the various drips. When the new anticholinergic drugs
were developed in the 1950s, they were found to produce sustained hypoacidity and
were tried as maintenance treatment, as an alternative to acid-lowering
operations. The third Mount Sinai approach was to attack the machinery of the
acid-producing cell itself by an inhibitor of the enzyme producing hydrogen ions.
In 1939, this enzyme had been thought to be carbonic anhydrase, but when Janowitz
and Hollander tested its inhibitor, acetazolamide, and showed marked but very
brief acid inhibition, they concluded that its action was too brief to be
therapeutically useful. The problem was to be solved decades later by H2 receptor
blockers from Britain and H+K+ATPase inhibitors from Sweden.
PMID- 10677785
TI - The pancreas.
AB - Pancreatic secretion was first studied at The Mount Sinai Hospital by Crohn in
1912, but measurements of pancreatic enzymes in duodenal aspirate or feces were
found unhelpful in diagnosis. Such pancreatic tests fell into disuse because of
advances in radiology of the biliary tree in the 1920s. Once extracts of secretin
and cholecystokinin-pancreozymin became available from Sweden in the 1930s, it
became possible for the biochemist Franklin Hollander and the surgeon David
Dreiling to develop pancreatic secretion tests into practical procedures for the
diagnosis of benign and malignant diseases of the pancreas and biliary tree, and
produce physiological studies of the mechanisms of ion transport. With more
purified hormones, it became possible to measure maximum (alkaline) bicarbonate
output of the pancreas analogous to the maximal acid response of the stomach to
an augmented histamine test, and to determine whether patients with duodenal
ulcer had decreased neutralization of gastric acid in the duodenum. Clinical
studies were also directed to the pathophysiology of acute relapsing and chronic
pancreatitis and carcinoma. However, advances in imaging and endoscopy have now
shifted the thrust of pancreatology.
PMID- 10677786
TI - The history of liver disease at The Mount Sinai Hospital.
AB - Diseases of the liver and biliary tract interested the physicians of The Mount
Sinai Hospital from the time the hospital started until the present. Indeed, the
institution has become a well-recognized center for the study of the liver and
its diseases. During the first 75 years of the hospital, there were many
admissions for hepatobiliary diseases, resulting in many case reports. The
evolution of the hospital into a teaching hospital brought with it a more
systematic method of studying diseases, not only in Pathology under Paul
Klemperer, but in clinical chemistry and microbiology as well. Liver biopsy was
also attempted. With the arrival of Hans Popper in 1957, the emphasis shifted to
coordinated studies of structure and function under normal circumstances and in
diseases as they progressed. Soon, Liver Diseases (Hepatology) were split from
Gastroenterology, with Fenton Schaffner as the first chief. Over the next 30
years, more than 1000 papers, chapters and books were published. The main areas
of research were fibrosis, cholestasis (especially morphology and bile salt
metabolism), toxic liver injury, metabolic transformations and carcinogenesis.
Primary biliary cirrhosis and viral hepatitis were and continue to be special
interests. Fellows from all over the world were trained and many moved on to
leadership positions. Although he was active in the development of the liver
transplant program, Popper did not live to see its start. A new generation of
hepatologists maintains the interest and position of The Mount Sinai Hospital in
this important field of medicine.
PMID- 10677787
TI - Alcohol and the liver: metabolism of alcohol and its role in hepatic and
extrahepatic diseases.
AB - Dr. Charles S. Lieber conducted clinical and experimental studies for more than
four decades (three at Mount Sinai and the Bronx VA Medical Centers) with
emphasis on liver, nutrition and GI pathophysiology. His major contributions
include elucidation of the pathogenesis of alcoholic liver disease, by
demonstrating the toxic role of alcohol and describing associated metabolic
disorders. This was achieved through judicious clinical studies and newly
developed rodent and primate models with the administration of ethanol in liquid
diets. The mechanisms of various pathological and metabolic effects of ethanol
were clarified, including hyperlipemia (with the rise in HDL), hyperuricemia, the
role of acetaldehyde toxicity and alcohol-induced oxidative stress. The latter,
including glutathione depletion, was corrected by S-adenosyl-1-methionine given
to alcohol-fed baboons; the compound is now being used successfully for the
treatment of patients with alcoholic liver disease in Europe. Alcoholic cirrhosis
was produced for the first time in nonhuman primates and shown to be fully
prevented by polyenylphosphatidylcholine, which is now being tested in a
multicenter clinical trial. Lieber also discovered a new (microsomal) pathway of
ethanol metabolism, responsible for the tolerance to ethanol and for several
clinically important toxic interactions with other drugs (e.g., acetaminophen),
anesthetics, industrial solvents, carcinogens, as well as retinol and b-carotene,
with narrowing of their therapeutic window. His work defined the role of the
stomach in ethanol metabolism, description of corresponding gender differences,
cloning (for the first time) of the gene for sigma ADH (a newly-recognized
gastric alcohol dehydrogenase isozyme) with its chromosomal localization, and the
discovery of the effects of commonly used medications (e.g., H2 blockers and
aspirin) on the activities of the enzyme and on blood alcohol levels in social
drinkers. Lieber was among the first to use antibiotics for the elimination of
gastric bacterial urease and its ammonia production in man, thereby alleviating
chronic gastritis and hypoacidity, with attenuation of hepatic encephalopathy in
cirrhotics. He promoted early detection and treatment of heavy drinkers before
their social or medical disintegration, by defining precirrhotic lesions and
markers of alcohol consumption. CONCLUSIONS: The research of Dr. Lieber and his
group yielded a better understanding of the pathogenesis of common hepatic,
gastric and nutritional disorders, with elucidation and prevention of serious
toxic alcohol-drug interactions and the development of methods for early
recognition and more effective approaches to prevent and treat liver and
gastrointestinal diseases.
PMID- 10677788
TI - The role of clinical risk factors in the prediction of future risk.
PMID- 10677789
TI - Predicting a second hip fracture.
AB - In an attempt to identify a high-risk cohort of patients, who could be offered
preventive therapy, we assessed patients who had suffered one hip fracture. A
total of 394 patients were prospectively followed to determine those who had
suffered a second fracture. Entry bone mass of the unfractured hip and total body
was examined by dual X-ray absorptiometry (DXA) and of the os calcis, by
quantitative ultrasound (QUS), along with various clinical parameters. The
relative risks in the QUS parameters did not reach significance, except for
broadband ultrasound attentuation as measured by the McCue CUBA Clinical, whereas
femoral neck and total body bone mineral density also reached significance.
Lowest quartile body weight was also a significant risk factor as were occurrence
of a new fall and poor mobility score. Using Receiver Operator Characteristic
curves, we found no significant differences between DXA trochanter or for the
Mini Mental State Examination score in predicting those who sustained a second
hip fracture. In this elderly group risk factors are almost as good as bone mass
at predicting those who will sustain a second hip fracture. Low body weight and
poor mobility could be used as triggers for the use of preventive therapy without
the use of bone mass measurements and to target expensive preventive therapy to
reduce fracture risk.
PMID- 10677790
TI - Influence of strontium on bone mineral density and bone mineral content
measurements by dual X-ray absorptiometry.
AB - The presence of Sr in bone influences bone mineral density (BMD) and content
(BMC) measurements by dual-energy X-ray absorptiometry (DXA). This interaction is
of interest, since strontium ranelate (S12911) demonstrated positive effects on
bone metabolism in various animal models of osteoporosis, and is currently being
evaluated for treatment of postmenopausal osteoporosis. The present in vitro
study aimed to determine adjustment factors for DXA measurements of BMC and BMD
at different Sr concentrations in order to estimate the corresponding values that
would have been measured without Sr. A series of mixtures of Ca and Sr
hydroxyapatites were prepared, with biologically relevant Sr/Ca ratios ranging
from 0 to 3.5 mol/mol%, and a constant total concentration of divalent cations
(145 mmol). The mixtures were conditioned in plastic dishes 4.5 cm in diameter,
to obtain an areal density close to the human vertebral mineral density of 0.7
1.1 g/cm(2). DXA measurements of the mixtures were made with a wide range of
different instruments and various acquisition modes. A direct linear relationship
(r(2) > 0.99) was found between strontium content and overestimation of BMD and
BMC. There were no significant differences in adjustment factors for BMC or BMD
between the different machines or acquisition modes, and the presence of Sr in
the water bath used to mimic soft tissues did not affect the accuracy and
precision of the method. This demonstrates that reliable DXA determinations of
BMD may be carried out in the presence of Sr, and may be interpreted in terms of
calcium hydroxyapatite equivalent if the bone Sr content of the measured bone is
known. The same adjustment factor (10% overestimation for 1 mol/mol% Sr) can be
used for all presently available types of instrument and acquisition modes.
PMID- 10677791
TI - Measurement of distal forearm bone mineral density: can different forearm
segments be used interchangeably ?
AB - Many different forearm sites have been used for the measurement of bone mineral
density (BMD) and prediction of risk of future fracture among community dwelling
populations. In populations where bone densitometry of peripheral sites may be
the most cost effective and practical means of measuring BMD, such as the nursing
home population, knowing the characteristics of forearm BMD measures would be
beneficial. The purpose of this study was to assess the relationship of four
common commercially available measures to each other and to estimate the inter-
and intrarater reliability of the measures in a sample of nursing home residents
as a first step toward identifying appropriate forearm measurement sites. These
sites were the distal radius, the distal ulna, a composite of the distal radius
and distal ulna, and the ultra distal radius. BMD measurements on 48 nursing home
patients were obtained using single X-ray absorptiometry. Inter- and intrarater
reliability was excellent at all four sites (interclass correlation coefficients
> 0. 85). Moderate to high correlations (0.84-0.91) between the distal radius and
ultra distal radius sites of the forearm suggest that these measures may be
interchangeable. Although not directly assessed here, differences in bone
composition among forearm sites may partially explain moderate rather than high
correlations between sites and may affect the ability of each site to predict
future fractures. Thus, different forearm sites may be used interchangeably for
diagnostic purposes; however, the prognostic value of each site remains unknown.
PMID- 10677792
TI - Quantitative ultrasound in the assessment of skeletal status in uremic patients.
AB - Renal osteodystrophy (ROD) can be characterized by both high (HT) and low (LT)
bone turnover states. Although bone biopsy remains the "gold standard" to
diagnose ROD, noninvasive tools for the diagnosis and follow-up of such bone
disease are desirable. Recently, ultrasound (US) techniques, proposed to assess
skeletal status, have been shown to be correlated not only with bone density but
also with bone quality. We have investigated 98 patients on chronic hemodyalisis
(HD) and 98 healthy, sex- and age-matched subjects. Amplitude-dependent speed of
sound (AD-SOS) and ultrasound bone profile score (UBPS) at phalanxes and speed of
sound (SOS), broadband ultrasound attenuation (BUA), and a quantitative
ultrasound index (QUI/stiffness) at the heel were performed in both groups. In
all subjects intact parathyroid hormone (PTH), total alkaline phosphatase (T
ALP), bone isoenzyme alkaline phosphatase (B-ALP), and carboxy-terminal
telopeptide of type I collagen (ICTP) were assessed. All US parameters were
significantly lower in the hemodialysis group than in control subjects. Moreover,
among US parameters only AD-SOS and UBPS showed a significant correlation with
PTH, T-ALP, and B-ALP. Dialytic age showed a modest, but significant correlation
only with US parameters at the phalanxes. On the basis of bone biochemical
markers, we considered a group with high and a group with normal to low bone
turnover. AD-SOS and UBPS, but not SOS, BUA, and stiffness were significantly (p
< 0.01) lower in the high bone turnover than in low bone turnover group.
Furthermore, in the high bone turnover group, parameters of the US phalanxes
strongly correlated with B-ALP. Our results seem to demonstrate that US
parameters are a useful tool in the assessment of skeletal status in patients on
maintenance dialysis.
PMID- 10677793
TI - Radiation dose to the patient and operator from a peripheral dual X-ray
absorptiometry system.
AB - Although peripheral dual X-ray absorptiometry (pDXA) scanners for measuring bone
mineral density (BMD) in the forearm are known to produce an exceptionally low
radiation dose to the patient, quantitative assessment of patient dose from pDXA
procedures is important for reassuring patients about their safety. We have
estimated the effective dose of radiation (ICRP-60) to the patient and also the
scattered dose to the operator from a forearm BMD examination performed on a DTX
200 pDXA system (Osteometer Meditech, Hoersholm, Denmark). Measurements were
performed using thermoluminescent dosimeters (TLD's) attached to the forearm
phantom supplied by the manufacturer. The effective dose to a patient was
estimated to be 0.1 microSv. At a distance of 1 m from the center of the forearm,
the time-averaged scattered dose to the operator assuming scanning five patients
per hour was measured to be <0.1 microSv/h. The dose rate over the outside
surface of the DTX-200 in line with the primary X-ray beam was measured to be 1.4
microSv/h. These figures compare with a natural background radiation in the
United Kingdom of 7 microSv/d. In conclusion the radiation doses from forearm
pDXA to both patients and operator were found to be truly trivial.
PMID- 10677794
TI - A comparison of calcaneus ultrasound and dual X-ray absorptiometry in healthy
North American youths and young adults.
AB - Quantitative ultrasound is the newest noninvasive method to be accepted for
assessing bone mineral in adults. Heel ultrasound measurements correlate with
bone density measurements by dual X-ray absorptiometry (DXA) and predict fracture
risk in adults. Far less is known about the value of calcaneus ultrasound (CUS)
in children. We determine spine, femoral neck, and whole-body bone mineral by DXA
and heel bone mass by CUS in 125 youths (69 females, 56 males) ages 9-25 yr. CUS
and DXA measurements of bone mass increased with age and pubertal development
during adolescence in a parallel fashion. Among females, Tanner stage was a
stronger predictor than age for all CUS and DXA measurements, and among males,
pubertal stage was a stronger predictor for spine bone mineral apparent density
(BMAD) and femoral bone mineral density (BMD). CUS measurements correlated
moderately well with DXA measurements of the spine, femoral neck, and whole-body
BMD and spine BMAD (r = 0.23-0.58, p < 0. 008). CUS warrants further study as a
tool for assessing bone mineral acquisition in children.
PMID- 10677795
TI - In vivo detection of structural differences between dominant and nondominant
radii using peripheral quantitative computed tomography.
AB - This cross-sectional study identifies differences in distal radial trabecular
bone structure related to habitual loading patterns in the upper extremities
using high-resolution peripheral quantitative computed tomography. As well, it
determines whether measurements of these indices in one limb serve as
satisfactory surrogates for the contralateral limb. The dominant and nondominant
forearms of 106 adult volunteers (mean age [SD], 44.3[17.5] yr) were scanned and
indices of trabecular bone structure (connectivity index [CI], maximum hole size
[H(M)], and mean hole size [H(A)]) were determined at the distal radius. The
images were also analyzed to determine bone density. For all subjects, H(M) is
significantly smaller in the dominant radius (p < 0.01). Right-handed subjects (n
= 96) have greater CI (p < 0.05) and smaller H(M) (p < 0.01) in the dominant
radius. For the total group, the dominant limb has a greater mass (total and
cortical bone mineral content, p < 0.01 and p < 0.05, respectively) and greater
total bone volumetric density (p < 0.05). There are no significant differences
between limbs for the group of left-handed subjects &lapr;n = 10). As expected,
significant associations exist between side-to-side measurements of bone
structure and density (p < 0.001). The correlation coefficients for connectivity
index, H(M), and H(A) are 0.86, 0.85, and 0.87, respectively. For bone density,
the between-limb associations are 0. 90, 0.73, and 0.92 for the total, cortical,
and trabecular bone compartments at the distal radius. Differences in the
structure of the trabecular bone network suggest that differential loading of the
dominant limb preserves bone strength.
PMID- 10677796
TI - Perspectives on bone mechanical properties and adaptive response to mechanical
challenge.
AB - The bones of the human skeleton serve a mechanical function besides providing a
reservoir for calcium and hematopoietic homeostatis. When mechanically
challenged, they usually respond and adapt; failure to do so can result in
fracture. The mechanical behavior of bone is determined by bone mass and its
material properties and by its geometry and architecture. Therefore, in vivo
noninvasive measurements of bone mass, geometry, and structure can predict bone
strength and are usually employed as a useful-if not always reliable-way to
estimate bone fragility, whereas direct bone biomechanical testing in vitro can
provide detailed information about mechanical strength. Because bone strains are
likely to be regulators of bone mass and strength, exercise protocols designed to
counteract the effects of osteoporosis should load the target bone with repeated
high peak forces and high strain rates or high impacts on a long-term basis. Such
a protocol creates varied strain distributions throughout the bone structure,
producing short, repeated strains on the bone in directions to which it is
unaccustomed. Exercise in this manner can maintain and perhaps increase bone mass
and improve mechanical properties and neuromuscular competency, reducing skeletal
fragility and the predisposition to falls.
PMID- 10677797
TI - A review of clinical trials of therapies for osteoporosis using fracture as an
end point.
AB - As the population ages, fragility fractures grow in importance as a public health
problem. The principal goal of osteoporosis therapy is primary and secondary
fracture prevention. A growing choice of therapies is now available for the
treatment of osteoporosis. In this article, we review their efficacy using
fracture prevention as an end point. The considerable heterogeneity among studies
with regard to patient age, past fracture history, fracture site, and analytical
methods precludes the possibility of performing a meaningful meta-analysis.
Fracture outcomes have been reported in clinical trials with calcium
supplementation, vitamin D supplementation, estrogen replacement therapy (ERT),
calcitonin, etidronate, alendronate, sodium fluoride (NaF), parathyroid hormone
(PTH), and raloxifene. Compelling evidence for fracture prevention has been
provided for calcium and vitamin D supplementation and alendronate treatment.
Evidence of fracture prevention exists for ERT, raloxifene, calcitonin,
etidronate, and PTH. Data on NaF are inconsistent. Across agents, there is a
trend toward greater efficacy for patients at greatest risk of fracture.
PMID- 10677798
TI - A marked increase in bone mineral density in a patient with glucocorticoid
induced osteoporosis.
AB - During the densitometric follow-up of a 73-yr-old male suffering from bullous
pemphigoid and glucocorticoid-induced osteoporosis, a marked increase in bone
mineral density (BMD) led to the diagnosis of an asymptomatic prostatic cancer
with secondary diffuse bone lesions. This eventuality must be considered in
patients with a rapid and unexplained gain in BMD.
PMID- 10677799
TI - Perspective on assessment of vitamin D nutrition.
AB - Although routine fortification of milk and a few other dairy products has been
successful in preventing rickets in children, its impact on preventing vitamin D
depletion in adults is less than satisfactory. The prevalence of vitamin D
depletion in the elderly is on the rise again and appears to be more common than
is currently appreciated. Several groups of individuals are at risk of developing
vitamin D depletion, and a significant minority of otherwise healthy individuals
is vitamin D insufficient. Unrecognized vitamin D depletion leads to secondary
hyperparathyroidism, accelerates cortical bone loss, and increases the risk of
hip fractures. With the availability of techniques to assess vitamin D nutrition,
it is probably cost effective to routinely measure 25-hydroxyvitamin D levels in
individuals at the greatest risk and in patients with various metabolic bone
diseases to prevent vitamin D depletion. Early recognition and prompt treatment
of vitamin D depletion improves functional well being of the individual, reduces
morbidity related to bone loss and fractures, and is associated with a highly
favorable cost/benefit ratio.
PMID- 10677800
TI - PROQUAD: accreditation program of the Brazilian society for clinical
densitometry.
AB - In 1996, the Brazilian Society for Clinical Densitometry (SBDens) developed an
accreditation program to be applied to all densitometry centers, under the
supervision of the certified physicians from SBDens. This program is named
Programa Nacional de Qualidade em Densitometria (PROQUAD) and was developed to
verify at least three aspects of the bone densitometry practice: the functioning
of equipment, the methods used by technicians in performing the scans, and how
the physicians are analyzing the scans and interpreting the results. From the 360
certified physicians who are members of SBDens, nearly one-third are
participating in this program. The final purpose of PROQUAD is to provide
approved centers with a seal, to be stamped on their examinations. The seal will
signify to referring physicians, and the community, which centers are working
under high standards of quality. It has been 2 yr since PROQUAD was established,
and the data obtained confirm the improvement of quality in the practice of
densitometry in Brazil. Any input from other societies that could improve PROQUAD
is welcomed. Ensuring good densitometry practices is a goal for which all
densitometry societies must strive.
PMID- 10677801
TI - Electroporation therapy of solid tumors.
AB - The curative effects of some chemotherapeutic drugs are impeded by their poor
permeation through the cell membrane. This limitation can be overcome by a novel
approach called electroporation therapy (EPT), electrochemotherapy (ECT), or
electrical impulse chemotherapy (EIC). The method involves application of brief
electrical pulses, which destabilize the cell membrane barrier, allowing
intracellular access of chemotherapeutic drugs that otherwise would not be able
to penetrate the cell membrane effectively. EPT makes it possible to lower the
drug dose, thereby relieving the patient of adverse side effects associated with
conventional chemotherapy. Even with the lower drug dose, EPT has shown
significantly higher efficacy than has conventional chemotherapy. The method is
currently being evaluated clinically for treating various cancer indications
using the anticancer drugs bleomycin or cisplatin. This article provides a
historical perspective and current insights into this new modality of cancer
treatment, including basic physical, biological, and medical facts about EPT;
computer-assisted development of electrical pulse generators and electrodes
necessary to create effective electrical fields in the treatment area; results of
cancer cell and tumor treatments in vitro, in animals, and in humans; safety
aspects of EPT; potential combined delivery of chemotherapeutic drugs and
biological agents to reduce or eliminate metastatic disease; and intracellular
delivery of DNA by electroporation for cancer gene therapy.
PMID- 10677802
TI - Pharmacodynamic aspects of modes of drug administration for optimization of drug
therapy.
AB - Because of various pharmacodynamic properties, such as the nonlinearity of the
concentration-effect relationship, activation of feedback homeostatic mechanisms,
induction of pharmacodynamic tolerance, etc., administration of the same dose of
drug by different modes is expected to produce different outcomes. This review
clarifies the theoretical and practical aspects of the impact of different modes
of drug administration on the magnitude of response, and hence on therapy
outcomes. It discusses how the interrelationship between the pharmacodynamic
properties and the drug input function affects the magnitude of response. To
demonstrate this special dimension of drug therapy, relevant pharmacodynamic data
was obtained for drugs with different therapeutic applications, including
antibiotics, analgesics, diuretics, anti-cancer, anti-ulcer, anti-inflammatory,
anti-hypertensive, lipid-lowering anti-parkinsonian, and immunosuppressive drugs.
These examples provide guidelines for implementing the role of the mode of drug
administration (including rate, schedule, and route of drug treatment) during
drug development or optimization of drug therapy.
PMID- 10677803
TI - Analysis of mean disintegration time and mean dissolution time by moment analysis
using microcalorimetric curves.
AB - The mean disintegration time (MDGT; mean time required for disintegration of
tablets) and mean dissolution time (MDST; mean time required for drug
dissolution) of water-soluble drugs from solid dosage forms were determined by
moment analysis using microcalorimetric curves. Microcalorimetric curves for heat
of dilution and for heat of dissolution of the drug were prepared, and the zeroth
and first moments of the calorimetric curves were then calculated. The difference
between the first moments of the curves for powder dissolution and tablet
dissolution was taken to be the MDGT. The difference between the first moment of
the curve for heat of dilution and that of the curve for heat of dissolution was
taken to be the MDST. Nicotinic acid and D-mannitol were used as model drugs. The
dissolution rate was determined by the conventional beaker method and also by the
deconvolution method. The dissolution process could be traced well by moment
analysis, as well as by the other methods employed. Moment analysis has some
advantages: (a) both the MDGT and the MDST can be determined simultaneously; (b)
it is applicable to many drugs that are soluble with heat evolution without the
need for quantitative analysis of the drug.
PMID- 10677804
TI - The release of 5-fluorouracil from microspheres of poly(epsilon-caprolactone-co
ethylene oxide).
AB - The purpose of this study was to evaluate the in vitro release of 5-fluorouracil
from microspheres prepared using a novel triblock copolymer of epsilon
caprolactone and ethylene oxide as the encapsulating material. Microspheres of
poly(epsilon-caprolactone-co-ethylene oxide) were prepared by employing the "hot
melt" method of microencapsulation. Microspheres were sized using sieve analysis
and scanning electron microscopy (SEM). Release studies were performed using a
custom-made rotating paddle dissolution apparatus. Copolymer microspheres,
fabricated by the hot melt method were shown by electron microscopy to have
smooth, nonporous surfaces. Drug-loaded microspheres were found to have a broad
distribution of sizes, which was thought to be a consequence of the wide range of
crystal sizes of the encapsulated unmilled drug. Nonlinear release kinetics were
observed from microspheres in the size fraction 75-250 microns, with a pronounced
"burst release" associated with the presence of drug at the surface of the
microspheres. A specific delineation of the drug release mechanism was not
possible due to rapid gelation, swelling, and subsequent dissolution of the
microspheres that occurred on hydration. This work describes the preparation of
microspheres that swell rapidly and coalesce together on hydration, accompanied
by rapid drug release and copolymer dissolution over a 2-hr period.
PMID- 10677805
TI - The stability of theophylline tablets with a hydroxypropylcellulose matrix.
AB - The behavior of 40:60 anhydrous theophylline/hydroxypropylcellulose (HPC) direct
compression tablets obtained using a variety of hydroxypropylcelluloses with low
or medium-high degrees of substitution (L-HPCs and HPCs, respectively) was
determined immediately following their preparation and after storage for 6 months
at 20 degrees C and a relative humidity (RH) of either 70.4% or 93.9%. The lower
relative humidity did not bring about hydration of the active principle in any
formulation, but the higher relative humidity totally hydrated the drug in all
except one L-HPC formulation, in which hydration remained incomplete. Both
relative humidities caused significant tablet swelling, with L-HPC formulations
being more affected than HPC formulations. Drug release was slowed by hydration
of the active principle, but accelerated with tablet swelling. The lower relative
humidity caused significant alteration of drug release characteristics in only
two L-HPC formulations, release from which was accelerated, while the higher
relative humidities only failed to cause such alterations in two HPC
formulations, with release from all except one of the others slowed (in the
exceptional formulation, which exhibited incompletely hydrated theophylline and
the greatest swelling of all, release was accelerated).
PMID- 10677806
TI - Development of matrix-based theophylline sustained-release microtablets.
AB - Microtablets containing high theophylline content (from 60% to 80%) based on a
Eudragit RS PO matrix were produced on a rotary tablet press. The influence of
the compaction pressure, the plasticizer content used for the granulation of
theophylline particles, and the amount of theophylline on the drug release were
investigated. The effects of surface area and the addition of magnesium stearate
as a hydrophobic agent on the drug release were studied. The storage stabilities
of the release rate at room temperature and at 50 degrees C were also determined.
Dissolution profiles expressed as percentage of theophylline dissolved were
obtained over 8 hr in 900 ml of purified water at 37 degrees C and 75 rpm. It was
observed that the compaction pressure (from 200 MPa to 250 MPa) had no effect on
the theophylline release. The use of triethyl citrate (TEC) as a plasticizer in
the granulation of theophylline enhanced the physical properties of the
microtablets. Theophylline content in the range 60% to 80% did not affect the
drug release. The theophylline release obtained was a function of the quotient
surface area/tablet weight and therefore was dependent on the tablet diameter. To
reduce the dissolution rates, magnesium stearate was added in a concentration up
to 50% of the matrix material. Tablets of this hydrophobic formulation fulfilled
the requirements of USP 23 for theophylline sustained-release preparations.
Storage at room temperature for 3 months and at 50 degrees C for 2 months showed
no significant influence on the theophylline release.
PMID- 10677807
TI - Bioavailability of itraconazole in rats and rabbits after administration of
tablets containing solid dispersion particles.
AB - A tablet dosage form containing solid dispersions of itraconazole (Asd tablets)
was prepared by using the spray-drying and wet granulation methods. The
dissolution rate of itraconazole from Asd tablets was fast, with more than 90%
released within 10 min, compared to less than 20% for a marketed product,
Sporanox capsules. The oral absorption of itraconazole from Asd tablets was
determined in rats and rabbits and was compared with that for Sporanox capsules.
In the rat, there was no difference between the Asd tablets and Sporanox capsules
in the mean area under the curve (AUC) (3089.5 +/- 4332.8 ng.hr/ml and 3653.9 +/-
2348.9 ng.hr/ml, respectively) and Cmax (295.0 +/- 344.5 and 390.5 +/- 169.4
ng/ml, respectively). Also, in the rabbit, no difference was found between the
two products in the mean AUC (AUMC; 19357.9 +/- 5117.5 ng.hr/ml and 23382.2 +/-
6236.5 ng.hr/ml, respectively) and Cmax (766.4 +/- 276.5 and 1127.5 +/- 577.9
ng/ml, respectively). Despite the rapid in vitro release characteristics of
itraconazole from the Asd tablets, the in vivo absorption of itraconazole was
comparable to that of Sporanox capsules, with no difference in Tmax in both
animal species. Serum levels of the major active metabolite hydroxyitraconazole
were also measured. Itraconazole was rapidly converted to hydroxyitraconazole in
both rats and rabbits, but there were species-specific differences in their
pharmacokinetics. It is concluded that, in addition to drug solubility and
dissolution characteristics, other formulation factors such as the physical state
of the drug and the granulation process, may also need to be considered in the
prediction of the in vivo absorption of itraconazole based on in vitro data.
PMID- 10677808
TI - The influence of hydrocolloid patch composition on the bioavailability of
triamcinolone acetonide in humans.
AB - Triamcinolone acetonide (TACA) is a corticosteroid; it is used in the systemic
and topical treatment of a variety of inflammatory conditions, including eczema
and psoriasis. Conventionally, for topical use, the drug is formulated in a cream
or ointment. However, it has been observed in vitro that percutaneous penetration
of corticosteroids can be influenced by hydrocolloid patches. Corticosteroids
produce a pallor or blanching when applied to the skin that correlates with anti
inflammatory activity; this property has been used extensively as a bioassay. The
aim of this study therefore was to evaluate the occlusive properties of a range
of hydrocolloid patches containing TACA on the drug's penetration in vivo using
visual assessment and a graded multiple measurement. The in vivo hydration of
these dermatological patches was also investigated. Statistical analysis of the
weight gains of patches containing either NaCMC 39% or pectin 39% showed that
there was a significant difference in the rates of hydration of the two types of
patch (p < .005). An increase in application time of the hydrocolloid patches
allowed more TACA to be released, which was illustrated by an increase in both
the maximum percentage total possible score (%TPS) values and AUC, although
changes in the hydrocolloid composition did not significantly alter the blanching
response. All of the patches adhered well, were unobtrusive to the normal
activity of the wearers, and showed great potential for the convenient,
localized, prolonged delivery of drugs to the skin.
PMID- 10677809
TI - The skin permeation mechanism of ketotifen: evaluation of permeation pathways and
barrier components in the stratum corneum.
AB - To evaluate the pathways and barrier components in the stratum corneum (SC) for
the permeation of ketotifen, the effect of delipidization on the permeation and
partition was examined under several donor pHs. Assuming that ionized ketotifen
(KTH+) and un-ionized ketotifen (KT) contribute independently in both permeation
and partition, the intrinsic permeability coefficients and SC/water partition
coefficients of both species were estimated. Delipidization enlarged the
permeability of KTH+ 100 times. This suggested that the lipid phase functions as
the barrier against KTH+. KT has an intrinsic permeability 100 times larger than
that of KTH+. Delipidization did not result in a significant change in
permeability of KT. This suggested that the permeability of KT through the lipid
phase is comparable to that through the aqueous phase in delipidized SC; that is,
the lipid phase functions as a highly permeable pathway for KT. On the other
hand, the permeability coefficient of KT through delipidized SC was 1/34 of that
through the pure aqueous layer, which had a thickness equivalent to SC. Since
this suggests that the permeability of KT through the proteinaceous phase is much
lower than that through the aqueous phase, the proteinaceous phase can be assumed
to function as a barrier against the permeation of KT. From these results, it is
concluded that the predominant permeation pathway for KT is through the lipid
phase. The SC/water partition coefficient of KT was cut in half by
delipidization, but the value was still more than 100. These results show that
the proteinaceous phase functions not only as the barrier, but also as the depot
for KT. The knowledge obtained here will be useful for formulation design and for
the selection of enhancers in a transdermal therapeutic system of ketotifen.
PMID- 10677810
TI - Application of a sensorial response model to the design of an oral liquid
pharmaceutical dosage form.
AB - In this paper, we discuss the application of a compartmental model to study the
sensorial response, in terms of taste intensity versus time, in an oral solution
for pharmaceutical use. The numerical model was developed from sensorial response
curves obtained by a panel of three trained individuals. Parameter identification
was carried out by means of a least-squares procedure that obtained the linear
coefficients in the model by solving an exact linear least-squares problem
conditional on the values of the nonlinear parameters for each iteration. Thus,
nonlinear estimation was done in terms of the first-order kinetic parameters
only, and ill-conditioning of the Hessian matrix present in these models was
solved. Results of modeling for a set of formulations were used to determine the
effects of various ingredients (sweeteners and an essence) on a baseline
unflavored formulation of acetaminophen in a mixture of cosolvents. The first
moment of the area under the curve of taste intensity versus time was found to be
the best global indicator of taste for the purpose of product design. It was
found that a mixture of sweeteners and an essence was the most efficient way of
masking the bitter taste of this active ingredient.
PMID- 10677811
TI - Biodegradable progesterone microsphere delivery system for osteoporosis therapy.
AB - The purpose of this study was to formulate and characterize a controlled-release
biodegradable delivery system of progesterone for the treatment or prevention of
osteoporosis. Microspheres of progesterone were formulated using copolymers of
poly(glycolic acid-co-dl-lactic acid) (PGLA 50/50 and PGLA 15/85) and poly(L
lactic acid) (L-PLA) of similar molecular weight by the emulsion solvent
evaporation technique. The effects of process variables, such as volume fraction,
polyvinyl alcohol (PVA) concentration, polymer composition, and stir speed during
preparation, on the yield, encapsulation efficiency (EEF), particle size
distribution, in vitro release profiles of progesterone, and surface morphology
of progesterone microspheres were investigated. Increasing the volume fraction
from 9% to 22% increased the EEF without significantly increasing the yield;
however, the rate of progesterone release from the microspheres decreased.
Increasing the PVA concentration from 1% to 5% had no significant influence on
the EEF, but the rate of progesterone release from microspheres increased.
Polymer composition had no significant effect on the EEF, but had a significant
effect on the particle size distribution, surface morphology, and release rate of
progesterone from the microspheres. Stir speed did not have a significant
influence on the EEF; however, stir speed influenced particle size distribution
and the rate of progesterone release from microspheres of the same sieve-size
range. The results suggest that controlled release of progesterone is possible by
varying the different process variables, and that PGLA 50/50 provided the slowest
release of progesterone. This should provide a means of delivering progesterone
for months for the treatment or prevention of osteoporosis in postmenopausal
women.
PMID- 10677812
TI - Scale-up of an oil/water cream containing 40% diethylene glycol monoethyl ether.
AB - The purpose of this study was to scale up an oil/water (o/w) cream formulation
containing 40% diethylene glycol monoethyl ether (DGME), developed via 300-g
laboratory batches in a 2(5-2) fractional factorial design, to 7-kg batch sizes
in a Brogli-10 homogenizer. The o/w cream was manufactured via a standard phase
inversion process in the Brogli-10 homogenizer. Partitioning studies of DGME were
conducted in test tubes at ambient temperature and after 24 hr at 70 degrees C in
a convection oven. Phase height was measured by vernier calipers. Microscopy
studies of excipients with and without treatment with water or a DGME/water
mixture were conducted with a Nikon microscope after equilibration at 35 degrees
C for 24 hr. During creation of the 7-kg pilot-scale batches, congealed material
was observed between the sweep agitation blade and the discharge port, where the
Brogli-10 homogenizer is not temperature jacketed. Factors that increased the
amount of congealed material were higher temperatures during primary
emulsification and longer cooling times. Partitioning studies revealed that DGME
resides in the aqueous external phase of this formulation. Microscopy studies
revealed that DGME in the external phase of this cream has a profound impact on
the solubility of certain solid, waxy excipients (e.g., cetyl alcohol and
polyoxyethylene-2-stearyl ether) at 35 degrees C. From this study, it appears
that DGME resides in the external phase of the o/w cream. During manufacturing,
it is hypothesized that the presence of DGME in the external phase alters the
solubility of certain solid, waxy excipients in the formula such that they no
longer primarily reside in the internal oil phase. On cooling, these materials
precipitate or congeal in the external phase. The fractional factorial
experimental design at the 300-g laboratory scale did not predict the issues
encountered during scale-up. Differences between laboratory scale and pilot plant
scale that explain why this phenomenon was not seen during laboratory scale are
differences in cooling times, nonjacketed or "cold spots" in the Brogli-10
homogenizer, and a low proportion of congealed material in relation to the total
batch size (< 1.5%).
PMID- 10677813
TI - The use of a hydrophobic matrix for the sustained release of a highly water
soluble drug.
AB - An experimental investigation into the use of a hydrophobic matrix to control the
release of a highly water soluble drug was undertaken. Matrices consisting of
hydrogenated vegetable oil and calcium sulfate with a 4% drug loading showed a
sustained-release profile of up to 24 hr. The release mechanism from such
matrices seemed to obey both root time kinetics and first-order behavior.
Investigations showed that the effect of geometry had a significant effect on the
drug release rate.
PMID- 10677814
TI - Interaction of ubiquinone-10 with dipalmitoylphosphatidylcholine and their
formation of small dispersed particles.
AB - Stable aqueous dispersions of ubiquinone-10 (UQ) were obtained by cosonication
with dipalmitoylphosphatidylcholine (DPPC) in the UQ mole fraction range 0.1-0.7.
To clarify the dispersal mechanism, the dispersed particles were characterized,
and the interaction between UQ and DPPC was investigated using several
physicochemical techniques. Dynamic light scattering (DLS) measurements showed
that the diameter of the dispersed particles was 50-70 nm. A limited amount of UQ
was incorporated into DPPC bilayer membranes (approximately 5 mol%). The trapped
aqueous volume inside the particles was determined fluorometrically using the
aqueous space marker calcein, and the volume in the UQ/DPPC particles decreased
remarkably with the addition of UQ into small unilamellar vesicles of DPPC. The
decline in the fraction of vesicular particles was also confirmed by fluorescence
quenching of N-dansylhexadecylamine in the DPPC membrane by the addition of the
quencher CuSO4. These results indicate that the excess UQ separated from the DPPC
bilayers is stabilized as emulsion particles by the DPPC surface monolayer.
PMID- 10677815
TI - An approach to controlled-release dosage form of propranolol hydrochloride.
AB - It is possible to release a drug with only limited diffusion from a membrane
coated system using osmotic pumping. In this study, a propranolol osmotic pump
was produced by coating the core tablets with cellulose acetate. The effects of
membrane thickness, pore size, and stirring rate on the release rate of
propranolol hydrochloride were studied. It was found that the thickness of
cellulose acetate membrane had a profound effect on the release rate of
propranolol hydrochloride from the membrane-coated tablets. The results showed
that, when the membrane thickness increased, the release rate of propranolol
decreased. The drug release follows a zero-order release when the delivery
orifice is between 200 and 800 microns, but when the delivery orifice size is
increased to 1000 microns, the release kinetic is abnormal. Fluid dynamics have
an important effect on the delivery rate of propranolol from this device; the
delivery rate increases as a function of the fluid flow. The drug release is
higher under a turbulent condition with high rate of stirring.
PMID- 10677816
TI - Studies of the drug permeability and mechanical properties of free films prepared
by cellulose acetate pseudolatex coating system.
AB - Free films produced with cellulose acetate (CA) pseudolatex were prepared by the
casting method. The effects of plasticizer concentration, drying temperature, and
drying time on drug permeability and mechanical properties of free films were
investigated by three-factor spherical second-order composite experimental
design. The results were analyzed by the multivariable regression method. The
experimental results indicated that plasticizer concentration, drying
temperature, and drying time had complex effects on free film permeability and
mechanical behavior. These results probably arise from the film-forming ability
of CA pseudolatex particles at various conditions and the evaporation of
plasticizer during the film-forming process.
PMID- 10677817
TI - Pharmacokinetics and urinary excretion of DW116, a new fluoroquinolone
antibacterial agent, in humans as a phase I study.
AB - Pharmacokinetics and urinary excretion of the new fluoroquinolone antibacterial
agent DW116 [1-(5-fluoro-2-pyridyl)-6-fluoro-7-(4-methyl-1-piperazynyl)-1, 4
dihydro-4-oxoquinolone-3-carboxylic acid, hydrochloride] following oral
administration (200, 400, 600 mg) were studied in humans as a phase I study. The
plasma concentration of DW116 declined monoexponentially with a half-life range
of 16-22 hr. The area under the curve (AUC) and Cmax increased proportionally as
the dose increased. The T1/2 and mean residence time (MRT) (28.3-30.9 hr) were
independent of dose. The Tmax appeared within 3 hr (0.9-2.7 hr) after drug
administration. The Ka ranged from 1.3 to 4.1 (hr-1). The plasma half-life was
much longer, and Cmax was higher by about two- to three-fold than conventional
fluoroquinolones. Urinary recovery of DW116 was 29.6-61.6% of the dose. The
maximum excretion rate appeared within 4 hr and decreased continuously after drug
administration. A urinary metabolite was not detected in the urine extract
obtained before and after hydrolysis by beta-glucuronidase (from Escherichia
coli); this was different from other fluoroquinolone antibacterial agents. Poor
metabolism in the kidney may contribute to the good oral bioavailability, but due
to the low recovery (< 60%) in urine, it is possible that DW116 is metabolized in
the liver or other organs.
PMID- 10677818
TI - Using online and offline change models to improve ICU access and revenues.
AB - BACKGROUND: Hospital operational problems that span departments often present
formidable challenges because they involve both processes and organizational
relationships. Many improvement efforts fail because of relationship issues
rather than a lack of understanding of system processes. Reflection on a recent
change initiative led to the development of an integrated change model that
includes both online and offline components. The online component draws on
performance improvement models that provide concepts and tools for use in team
meetings to improve processes. The offline component borrows from an earlier
tradition of change management that offers guidelines for individuals or teams
desiring to be change agents. METHODS: The integrated change model was applied in
1997 at The Johns Hopkins Hospital, Baltimore, to reduce ambulance bypass hours,
a chronic problem resulting in $6.7 million in lost revenue annually. The goal
was to reduce red alert hours per month by 50%. Three Plan-Do-Study-Act (PDSA)
cycles were implemented to test change concepts. RESULTS: There was a significant
reduction in red alert hours after the change initiative, with an estimated $6
million in additional hospital revenue. DISCUSSION: The integrated change model
may serve as a prototype for improving complex problems in which improving
organizational relationships may be as difficult as improving processes and is
likely to require a significant amount of work offline. For example, this
approach may be particularly helpful for improving processes that span
departments or functional units such as reducing cycle times for admissions,
first-dose medications, as well as in building and improving integrated delivery
systems. The model awaits further testing and evolution.
PMID- 10677819
TI - Improving management of atrial fibrillation and anticoagulation in a community
hospital.
AB - BACKGROUND: Clinical trials have established the safety and efficacy of warfarin
anticoagulation for stroke prevention in patients with atrial fibrillation. Other
studies have documented patterns of underutilization and suboptimal warfarin
therapy; physician underuse of warfarin may reflect the demands associated with
monitoring the drug's effects. BASELINE STUDY: At Carney Hospital, a 230-bed
acute care community teaching hospital in Boston, a retrospective chart review
indicated that between July 1, 1995, and June 30, 1996, of 465 patients admitted
with atrial fibrillation, 209 (45%) patients were discharged with warfarin
therapy: 198 were receiving warfarin at admission, and 11 began therapy during
hospitalization. Analysis of the admission international normalized ratios (INRs)
indicated that a minority of patients on warfarin were safely anticoagulated at
the time of admission. DESIGNING THE INTERVENTION: An anticoagulation clinic was
established in fall 1997 to increase utilization of warfarin, standardize
anticoagulation practices, and minimize physician time and effort needed to
ensure safe anticoagulation. In early 1998 monitoring of hospitalized patients
with chronic atrial fibrillation began. RESULTS: The proportion of patients
receiving warfarin therapy at admission increased from 46% in February-May 1998
to 63% in April-June 1999. Between October 1997 and July 1998, 49.1% of the 2,738
patient visits to the anticoagulation clinic showed an INR in the desired range.
For the 2,238 visits during January through August 1999, 53.7% of the INRs were
in the desired range. DISCUSSION: Establishment of a clinic to oversee warfarin
therapy and dissemination of indications for anticoagulation in patients with
atrial fibrillation were followed by increases in the frequency of warfarin use
in hospital patients and the incidence of safe therapy in ambulatory patients.
PMID- 10677820
TI - Merging clinical pathway programs as part of overall health system mergers: a ten
step guide. Spectrum Health.
AB - BACKGROUND: Mergers, acquisitions, and reorganizations can be stressful and
accompanied by ambivalence, confusion, and uncertainty. Providing clear and
simple steps for merging clinical pathways may help organizations move through
the transition process more smoothly. The ten steps according to which Spectrum
Health merged its pathway program-conduct an inventory of previous efforts, plan
for the ideal program, bring staff together early in the merger process, decide
on a common format, standardize the development and revision process, standardize
a reporting tool, create a clinical pathway manual, implement an educational
plan, present the program to key customers, and appoint an advisory group-need
not be done sequentially. The ten-step pathway merger program uses pathways as a
means to improve the quality of the care provided, with a focus on
multidisciplinary clinical pathway teamwork. Before the merger, the two hospital
systems' pathway programs used different approaches to operations and pathway
format. When the announcement to merge came in September 1997, steps to merge the
clinical pathway programs began. DISCUSSION: More than two years into the merger,
Spectrum Health continues to struggle with the evolution of the health system.
Clinical pathways represent just one of the significant and extensive issues
related to organizational mergers; organizational values, finances, vision,
mission, customer relations, strategic priorities, and people issues are a few of
the others. Focusing on merging programs such as clinical pathway programs can
help put one large piece of the merger puzzle in place and reduce some of the
ambiguity associated with all mergers. Executive support is critical to the
success of the clinical pathway program.
PMID- 10677821
TI - Controlled trials of CQI and academic detailing to implement a clinical practice
guideline for depression.
AB - BACKGROUND: The release of the Agency for Health Care Policy and Research
(AHCPR)'s Guideline for the Detection and Treatment of Depression in Primary Care
created an opportunity to evaluate under naturalistic conditions the
effectiveness of two clinical practice guideline implementation methods:
continuous quality improvement (CQI) and academic detailing. A study conducted in
1993-1994 at Kaiser Permanente Northwest Division, a large, not-for-profit
prepaid group practice (group-model) HMO, tested the hypotheses that each method
would increase the number of members receiving depression treatment and would
relieve depressive symptoms. METHODS: Two trials were conducted simultaneously
among adult primary care physicians, physician assistants, and nurse
practitioners, using the same guideline document, measurement methods, and one
year follow-up period. The academic detailing trial was randomized at the
clinician level. CQI was assigned to one of the setting's two geographic areas.
To account for intraclinician correlation, both trials were evaluated using
generalized equations analysis. RESULTS: Most of the CQI team's recommendations
were not implemented. Academic detailing increased treatment rates, but--in a
cohort of patients with probable chronic depressive disorder--it failed to
improve symptoms and reduced measures of overall functional status. CONCLUSIONS:
New organizational structures may be necessary before CQI teams and academic
detailing can substantially change complex processes such as the primary care of
depression. New research and treatment guidelines are needed to improve the
management of persons with chronic or recurring major depressive disorder.
PMID- 10677822
TI - Water-macromolecule interactions by NMR: a quadrature-free constant-time approach
and its application to CI2.
AB - A pulse sequence is proposed to select water magnetization with enhanced
specificity through a synergetic combination of several filtering principles.
This approach relies on a constant-time evolution period implemented without
quadrature detection, which results in a square root 2 increase in signal-to
noise ratios as compared to traditional non-selective methods for water
filtration. In addition, the quadrature-free constant-time block facilitates the
implementation of the water flip-back strategy, which leads to further gains in
sensitivity. The proposed experiment was applied to unlabeled HEW lysozyme and to
15N-labeled chymotrypsin inhibitor 2 which was partially or non 13C-enriched.
Water molecules belonging to a spine of hydration between two pseudo beta-sheet
strands were identified, solving previously reported discrepancies between the X
ray and refined NMR structure of CI2. The proposed experiment in particularly
suitable for hydration studies of mixtures of labeled and unlabeled components,
such as ligand-macromolecule complexes.
PMID- 10677823
TI - Random-coil chemical shifts of phosphorylated amino acids.
AB - The 1H, 13C, 15N and 31P random-coil chemical shifts and phosphate pKa values of
phosphorylated amino acids pSer, pThr and pTyr in the protected peptide Ac-Gly
Gly-X-Gly-Gly-NH2 have been obtained in water at 25 degrees C over the pH range 2
to 9. Analysis of ROESY spectra indicates that the peptides are unstructured.
Phosphorylation induces changes in random-coil chemical shifts, some of which are
comparable to those caused by secondary structure formation, and are therefore
significant in structural analyses based on the chemical shift.
PMID- 10677824
TI - Observation of internucleotide NH...N hydrogen bonds in the absence of directly
detectable protons.
AB - Several structural motifs found in nucleic acids involve N-H...N hydrogen bonds
in which the donor hydrogens are broadened to extinction due to chemical or
conformational exchange. In such situations, it is impossible to use the well
established HNN-COSY or soft HNN-COSY experiments, which report the presence of
the hydrogen bond directly on the donor proton(s). We present a pulse sequence,
H(CN)N(H), for alleviating this problem in hydrogen bonds of the type NdH...Na
CH, in which the donor Nd nitrogen is correlated with the corresponding non
exchangeable C-H proton associated with the acceptor Na nitrogen. In this way,
missing NdH...Na correlations in an HNN-COSY spectrum may be recovered from CH-Nd
correlations in the H(CN)N(H) spectrum. By correlating a different set of nuclei
relative to the HNN-COSY class of experiments, the H(CN)N(H) experiment also
serves to remove ambiguities associated with degeneracies in HNN-COSY spectra.
The technique is demonstrated on d(GGAGGAG)4,a quadruplex containing a novel A.
(G.G.G.G). A hexad and on d(GGGCAGGT)4, containing a G.G.G.C tetrad, in which
missing NH2...N7 correlations are retrieved via H8-(N2,N6) correlations in the
H(CN)N(H) spectrum.
PMID- 10677825
TI - Solvation study of the non-specific lipid transfer protein from wheat by
intermolecular NOEs with water and small organic molecules.
AB - Intermolecular nuclear Overhauser effects (NOEs) were measured between the
protons of various small solvent or gas molecules and the non-specific lipid
transfer protein (ns-LTP) from wheat. Intermolecular NOEs were observed with the
hydrophobic pocket in the interior of wheat ns-LTP, which grew in intensity in
the order cyclopropane (saturated solution) < methane (140 bar) < ethane (40 bar)
< acetonitrile (5% in water) < cyclohexane (saturated solution) < benzene
(saturated solution). No intermolecular, NOEs were observed with dioxane (5% in
water). The intermolecular NOEs were negative for all of the organic molecules
tested. Intermolecular NOEs between wheat ns-LTP and water were weak or could not
be distinguished from exchange-relayed NOEs. As illustrated by the NOEs with
cyclohexane versus dioxane, the hydrophobic pocket in wheat ns-LTP preferably
binds non-polar molecules. Yet, polar molecules like acetonitrile can also be
accommodated. The pressure dependence of the NOEs between methane and wheat ns
LTP indicated incomplete occupancy, even at 190 bar methane pressure. In general,
NOE intensities increased with the size of the ligand molecule and its vapor
pressure. NMR of the vapor phase showed excellent resolution between the signals
from the gas phase and those from the liquid phase. The vapor concentration of
cyclohexane was fivefold higher than that of the dioxane solution, supporting the
binding of cyclohexane versus uptake of dioxane.
PMID- 10677826
TI - Efficient side-chain and backbone assignment in large proteins: application to
tGCN5.
AB - In determining the structure of large proteins by NMR, it would be desirable to
obtain complete backbone, side-chain, and NOE assignments efficiently, with a
minimum number of experiments and samples. Although new strategies have made
backbone assignment highly efficient, side-chain assignment has remained more
difficult. Faced with the task of assigning side-chains in a protein with poor
relaxation properties, the Tetrahymena histone acetyltransferase tGCN5, we have
developed an assignment strategy that would provide complete side-chain
assignments in cases where fast 13C transverse relaxation causes HCCH-TOCSY
experiments to fail. Using the strategy presented here, the majority of aliphatic
side-chain proton and carbon resonances can be efficiently obtained using
optimized H(CC-CO)NH-TOCSY and (H)C(C-CO)NH-TOCSY experiments on a partially
deuterated protein sample. Assignments can be completed readily using additional
information from a 13C-dispersed NOESY-HSQC spectrum. Combination of these
experiments with H(CC)NH-TOCSY and (H)C(C)NH-TOSCY may provide complete backbone
and side-chain assignments for large proteins using only one or two samples.
PMID- 10677827
TI - Determination of sugar conformation in large RNA oligonucleotides from analysis
of dipole-dipole cross correlated relaxation by solution NMR spectroscopy.
AB - A new experiment, the forward directed quantitative gamma-HCCH-TOCSY for the
measurement of the conformation of the five-membered ribosyl unit in RNA
oligonucleotides, is presented. The experiment relies on quantification of cross
peak intensities caused by evolution of CH, CH-dipole-dipole cross correlated
relaxation in non-evolution periods and the resolution enhancement obtainable in
forward directed HCC-TOCSY transfer. Cross correlated relaxation rates are
interpreted to reveal the sugar conformation of 22 out of 25 nucleotides in an
isotopically labelled 25-mer RNA. The results obtained with this new method are
in agreement with the conformational analysis derived from 3J(H,H) coupling
constants.
PMID- 10677829
TI - 1H and 15N sequential assignment and solution secondary structure of 15N labelled
human pancreatic ribonuclease.
PMID- 10677828
TI - HYPER: a hierarchical algorithm for automatic determination of protein dihedral
angle constraints and stereospecific C beta H2 resonance assignments from NMR
data.
AB - A new computer program, HYPER, has been developed for automated analysis of
protein dihedral angle values and C beta H2 stereospecific assignments from NMR
data. HYPER uses a hierarchical grid-search algorithm to determine allowed values
of phi, psi, and chi 1 dihedral angles and C beta H2 stereospecific assignments
based on a set of NMR-derived distance and/or scalar-coupling constraints.
Dihedral-angle constraints are valuable for restricting conformational space and
improving convergence in three-dimensional structure calculations. HYPER computes
the set of phi, psi, and chi 1 dihedral angles and C beta H2 stereospecific
assignments that are consistent with up to nine intraresidue and sequential
distance bounds, two pairs of relative distance bounds, thirteen homo- and
heteronuclear scalar coupling bounds, and two pairs of relative scalar coupling
constant bounds. The program is designed to be very flexible, and provides for
simple user modification of Karplus equations and standard polypeptide
geometries, allowing it to accommodate recent and future improved calibrations of
Karplus curves. The C code has been optimized to execute rapidly (0.3-1.5 CPU-sec
residue-1 using a 5 degrees grid) on Silicon Graphics R8000, R10000 and Intel
Pentium CPUs, making it useful for interactive evaluation of inconsistent
experimental constraints. The HYPER program has been tested for internal
consistency and reliability using both simulated and real protein NMR data sets.
PMID- 10677830
TI - 1H, 13C and 15N chemical shift assignments of the capsid protein from Rous
sarcoma virus.
PMID- 10677831
TI - 1H, 15N, and 13C resonance assignment of the PH domain from C. elegans UNC-89.
PMID- 10677832
TI - The use of solid-phase microextraction in conjunction with a benchtop quadrupole
mass spectrometer for the analysis of volatile organic compounds in human blood
at the low parts-per-trillion level.
AB - The analysis of volatile organic compounds (VOCs) in whole human blood at the low
parts-per-trillion level has until recently required the use of a high-resolution
mass spectrometer to obtain the specificity and detection limits required for
epidemiological studies of VOC exposure in the general public. Because of the
expense and expertise required to operate and maintain a high-resolution
instrument, the applicability of this method has been limited. These limitations
are overcome in a new method using automated headspace solid-phase
microextraction (SPME) in conjunction with a gas chromatograph and a benchtop
quadrupole mass spectrometer. A combination of SPME and multiple single-ion
monitoring minimizes the interferences and chemical noise associated with whole
blood samples. This method permits the analysis of 10 VOCs in human blood while
simplifying the sample preparation and reducing the possible exposure of the
analyst to blood aerosols. Twelve samples can be run successively in a fully
automated mode, thus eliminating the need for operator attention. Detection
limits are below 50 ppt (pg/mL) for a majority of the VOCs tested with a 5-mL
sample.
PMID- 10677833
TI - Determination of polycyclic aromatic hydrocarbons in sediment using solid-phase
microextraction with gas chromatography-mass spectrometry.
AB - Manual solid-phase microextraction (SPME) coupled with gas chromatography-mass
spectrometry (GC-MS) is applied for the determination of polycyclic aromatic
hydrocarbons (PAHs) from natural matrix through a distilled water medium. Seven
of the 16 PAH standards (naphthalene, acenaphthene, fluorene, anthracene,
fluoranthene, pyrene, benzo[a]anthracene) are spiked on a marine muddy sediment.
The samples, containing PAHs in the range of 10-20 ppm, are then aged at room
temperature more than 10 days before analysis. The influence of the matrix, SPME
adsorption time, pH, salt content, and SPME adsorption temperature are
investigated. The reproducibility of the technique is less than 13% (RDS) for the
first 6 considered PAHs and 28% (RDS) for benzo(a)anthracene with a fiber
containing a 100-micron poly dimethylsiloxane coating. Linearity extended in the
range of 5-50 picograms for PAHs direct injection, 5-70 picograms for PAHs in
water, and 1-170 picograms for PAHs in sediment. The detection limit is estimated
less than 1 microgram/kg of dry sample for the first 6 considered PAHs in
sediment and 1.5 micrograms/kg of dry sample for benzo(a)anthracene using the
selected ion monitoring mode in GC-MS. The recoveries of the considered PAHs are
evaluated.
PMID- 10677834
TI - Complexation ion-exchange chromatography of some metal ions on papers impregnated
with Ti(IV)-based inorganic ion exchangers.
AB - The chromatographic behavior of 40 metal ions is studied on titanium (IV)
arsenate, titanium (IV) phosphate-, titanium (IV) molybdate-, titanium(IV)
tungstate-, and titanium(IV) selenite-impregnated papers in 0.1M oxalic, citric,
and tartaric acid as mobile phases. Similar studies are carried out on Whatman
No. 1 papers for comparison. The ion-exchange capacity of these papers is
determined, and their selectivity for different cations is discussed. The
mechanism of migration is explained in terms of ion-exchange, precipitation, and
adsorption. The prediction of elution sequence from RF values is also checked.
The average Ri is found to be almost linearly dependent on the charge of the
metal ions. The effect of the pKa of complexing acids on average RF values of 3d
series metal ions is explained. A number of binary and ternary separations are
achieved.
PMID- 10677835
TI - A convenient method for routine estimation of dead time in gas chromatography.
AB - A set of retention times (tR) of n-alkanes at different temperatures and the
primary dead times (tM) are used to determine the 4 numerical constants (a, b, c,
and d) of an equation. This equation is rearranged into a second equation, used
in turn for routine calculation of the secondary dead time (tMS) of each
chromatogram from any member of the n-alkane series. Equation 2 can be used to
calculate the tMS of both packed and capillary columns. The calculated tMS values
are in good agreement with those of the tM values. The greatest difference is
3.38%, but it is speculated that the percent difference would be lower when more
tR data are collected for the determination of the 4 numerical constants of
Equation 1. Error in measurement of retention time undoubtedly would affect the
accuracy of the estimated dead time, but it is attenuated by a factor of 1 + e(a
+ bN + c/T + dN/T).
PMID- 10677836
TI - Liquid chromatographic determination of rifampin in human plasma, bronchoalveolar
lavage fluid, and alveolar cells.
AB - A technique is presented for the measurement of rifampin in humans by reversed
phase column chromatography and postcolumn photo irradiation. The assay employs
diazepam as an internal standard and provides specific, rapid, and reliable
determinations for drug concentration in plasma, bronchoalveolar lavage (BAL),
and alveolar cells (AC). The preparation of plasma and AC samples utilizes a
simple deproteinization step, whereas BAL supernatants require a solid-phase
extraction. The assay produces sharp peaks with retention times of 6.2 and 15 min
for rifampin and diazepam, respectively. The detection limits for rifampin were
0.5 microgram/mL for plasma, 0.015 microgram/mL for BAL supernatants, and 0.03
microgram/mL for AC suspensions. The assay has excellent performance
characteristics, making it suitable for pharmacological studies in humans, and it
is being used to support a study of the intrapulmonary pharmacokinetics of
rifampin.
PMID- 10677838
TI - Gas chromatography problem solving and troubleshooting.
PMID- 10677837
TI - Analyte loss due to membrane filter adsorption as determined by high-performance
liquid chromatography.
AB - The phenomenon of membrane filter adsorption in high-performance liquid
chromatography (HPLC) is investigated utilizing 16 brands of filters representing
3 polymeric materials: cellulose acetate (CA), nylon, and polyvinylidene
difluoride in a variety of diameters (3, 4, 7, 13, and 25 mm). Sixteen compounds
commonly encountered in drug preparations are selected as sample analytes and
classified as acidic, basic, and neutral in chemical behavior. Six mobile
phase/sample solvent mixtures are included: 3 with methanol-water and 3 with
acetonitrile-water as major constituents. When using methanol as the mobile phase
organic component, CA, nylon, and polyvinylidene difluoride (PVDF) filters
exhibit negligible to moderate adsorption levels with regard to the neutral and
basic drug compounds. The acidic drug test compounds are adsorbed by 50% of all 3
filter materials tested in methanol-water. In acetonitrile, neutral compounds are
affected by 31.4%, basic compounds are affected by 47.0%, and acidic compounds
are affected by 53.6% of the nylon and PVDF filters. CA is incompatible with
acetonitrile and is excluded from the study with this solvent.
PMID- 10677839
TI - Disinfectant effects of hot water, ultraviolet light, silver ions and chlorine on
strains of Legionella and nontuberculous mycobacteria.
AB - The disinfectant effects on Legionella and nontuberculous mycobacteria of hot
water, ultraviolet light, silver ions and chlorine, were evaluated. The bacterial
strains Legionella pneumophila ATCC33152 and Mycobacterium avium ATCC25291 and
strains of L. pneumophila and M. avium which had been isolated from a 24 h bath,
were examined for their resistance to treatments. All strains were killed within
3 min on exposure to hot water at 70 degrees C and exposure to ultraviolet light
at 90 mW.s/cm2. The strains of L. pneumophila tested were killed within 6 h on
exposure to a solution of silver ions at 50 micrograms/l. The number of viable
cells of strains of M. avium fell from 10(5) CFU/ml to 10(3) CFU/ml after
exposure to an aqueous solution of silver ions at 100 micrograms/l for 24 h.
Chlorine effectively killed strains of Legionella which were exposed to an
aqueous solution of chlorine at 2 mg/l within 3 min, but strains of Mycobacterium
survived exposure to chlorine at 4 mg/l for more than 60 min.
PMID- 10677840
TI - Enhancement of growth and toxin production of Clostridium argentinense by co
culture with Pseudomonas mendocina.
AB - The growth and toxin production of Clostridium argentinense in co-culture with
Pseudomonas mendocina was examined in a micro-fermenter without aeration
characterizing the association in terms of several growth parameters. The biomass
obtained in co-cultures was 4.4 times higher than that in C. argentinense
monocultures with total consumption of the carbon source. The pH and Eh attained
in co-cultures at later stages of cultivation were suitable for toxin production
by C. argentinense. In comparison with C. argentinense monocultures the
production of toxin was 17.5 times higher with a specific toxicity of 0.56 LD50
per g of co-culture biomass.
PMID- 10677841
TI - Flow cytometric analysis of a marine LAS-degrading consortia.
AB - The specific nucleic acid fluorochrome SYTO-13 was used in flow cytometric
analysis to assess changes in the density and heterogeneity of marine bacterial
populations which biodegrade linear alkylbenzene sulphonate (LAS). Seawater
samples with LAS and incubated in the laboratory (20 degrees C, 100 rpm, 30 days)
were used to monitor LAS-degrading consortia. Flow cytometric studies and culture
methods were used to characterize the LAS degrading bacterioplankton consortia.
Fluorescence and scatter signals enabled us to define three regions (R1, R2 and
R3) in the dual parameter cytograms. The distribution of the bacterial counts in
these regions allowed us to monitor the formation and evolution of the consortia.
PMID- 10677842
TI - Effects of caffeic acid, chlorogenic acid and ferulic acid on growth and
arylamine N-acetyltransferase activity in Shigella sonnei (group D).
AB - Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene (2-AF) as
substrates were determined in Shigella sonnei (group D) collected from patients
with diarrhoeal disease. The NAT activity was determined using an acetyl CoA
recycling assay and high pressure liquid chromatography. Inhibition of growth
studies from S. sonnei (group D) demonstrated that caffeic acid (CA), chlorogenic
acid (CGA) and ferulic acid (FA) elicited a dose-dependent bactericidal effect in
S. sonnei (group D) cultures, i.e. the greater the concentration of CA, CGA and
FA, the greater the inhibition of growth of S. sonnei (group D). Cytosols or
suspensions of S. sonnei (group D) with and without selected concentrations of
CA, CGA and FA co-treatment showed different percentages of 2-AF acetylation. The
data indicated that there was reduced NAT activity associated with increased CA,
CGA and FA in Shigella dysenteriae (group D) cytosols and intact cells. For the
cytosol and intact bacteria examinations, the apparent values of K(m) and Vmax
decreased after being co-treated with 400 microM CA, CGA and FA. This report is
the first demonstration of plant phenolic inhibition (CA, CGA and FA) of
arylamine NAT activity and growth in the bacterium S. sonnei (group D).
PMID- 10677843
TI - Effects of media composition of delta-endotoxin production and morphology of
Bacillus thuringiensis in wild types and spontaneously mutated strains.
AB - Bacillus thuringiensis strains HD-73 and 4412, and two spontaneous mutants termed
4412aa-ind and 4412sph-cry were studied for the ability to produce crystals of
different size and shape when grown in a rich medium and in an appropriate
minimal medium defined during this study. Strain 4412aa-ind showed medium
dependent variation in the crystal phenotype. Scanning electron microscopy was
utilized in order to show crystal variations in size and shape. B. thuringiensis
strains 4412aa-ind and 4412sph-cry grown in rich and in minimal media produced
differences in crystal morphology, and SDS-PAGE gel indicated that crystal
variation was only at the morphological level and not in composition of the amino
acids. A further nineteen B. thuringiensis strains were tested for the ability to
sporulate in two simple defined media. Of these strains thirteen were able to
complete sporulation with crystal production in one or both media. All strains
grew and sporulated in a medium containing the usual twenty amino acids, and no
vitamins or other growth factors were required.
PMID- 10677844
TI - Compartment-specific isoforms of TPI and GAPDH are imported into diatom
mitochondria as a fusion protein: evidence in favor of a mitochondrial origin of
the eukaryotic glycolytic pathway.
AB - Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and triosephosphate isomerase
(TPI) are essential to glycolysis, the major route of carbohydrate breakdown in
eukaryotes. In animals and other heterotrophic eukaryotes, both enzymes are
localized in the cytosol; in photosynthetic eukaryotes, GAPDH and TPI exist as
isoenzymes that function in the glycolytic pathway of the cytosol and in the
Calvin cycle of chloroplasts. Here, we show that diatoms--photosynthetic protists
that acquired their plastids through secondary symbiotic engulfment of a
eukaryotic rhodophyte--possess an additional isoenzyme each of both GAPDH and
TPI. Surprisingly, these new forms are expressed as an TPI-GAPDH fusion protein
which is imported into mitochondria prior to its assembly into a tetrameric
bifunctional enzyme complex. Homologs of this translational fusion are shown to
be conserved and expressed also in nonphotosynthetic, heterokont-flagellated
oomycetes. Phylogenetic analyses show that mitochondrial GAPDH and its N-terminal
TPI fusion branch deeply within their respective eukaryotic protein phylogenies,
suggesting that diatom mitochondria may have retained an ancestral state of
glycolytic compartmentation that existed at the onset of mitochondrial symbiosis.
These findings strongly support the view that nuclear genes for enzymes of
glycolysis in eukaryotes were acquired from mitochondrial genomes and provide new
insights into the evolutionary history (host-symbiont relationships) of diatoms
and other heterokont-flagellated protists.
PMID- 10677845
TI - Mitochondrial genes and mammalian phylogenies: increasing the reliability of
branch length estimation.
AB - Since branch lengths provide important information about the timing and the
extent of evolutionary divergence among taxa, accurate resolution of evolutionary
history depends as much on branch length estimates as on recovery of the correct
topology. However, the empirical relationship between the choice of genes to
sequence and the quality of branch length estimation remains ill defined. To
address this issue, we evaluated the accuracy of branch lengths estimated from
subsets of the mitochondrial genome for a mammalian phylogeny with known
subordinal relationships. Using maximum-likelihood methods, we estimated branch
lengths from an 11-kb sequence of all 13 protein-coding genes and compared them
with estimates from single genes (0.2-1.8 kb) and from 7 different combinations
of genes (2-3.5 kb). For each sequence, we separated the component of the log
likelihood deviation due to branch length differences associated with alternative
topologies from that due to those that are independent of the topology. Even
among the sequences that recovered the same tree topology, some produced
significantly better branch length estimates than others did. The combination of
correct topology and significantly better branch length estimation suggests that
these gene combinations may prove useful in estimating phylogenetic relationships
for mammalian divergences below the ordinal level. Thus, the proper choice of
genes to sequence is a critical factor for reliable estimation of evolutionary
history from molecular data.
PMID- 10677846
TI - High DNA sequence variability at the alpha 1 Na/K-ATPase locus of Artemia
franciscana (brine shrimp): polymorphism in a gene for salt-resistance in a salt
resistant organism.
AB - We previously reported that the Na/K-ATPase alpha 1 subunit coding gene showed
signs of being a very polymorphic locus in Artemia franciscana. This species is
adapted to highly saline waters, and the Na/K-ATPase alpha 1 isoform presumably
plays a key role in this adaptation. Therefore, we were interested in further
study of the alpha 1 Na/K-ATPase polymorphisms to examine whether they might be
due to an adaptation to salt resistance driven by natural selection. Using coding
sequences from 10 genomic clones and 3 cDNAs, we observed that most substitutions
are in synonymous positions (88.8%). The 12 nonsynonymous substitutions code for
conservative amino acid replacements with an apparent scattered distribution
across functional domains of the protein. Interspecific comparison between these
sequences and two genomic clones from Artemia parthenogenetica containing 1,122
bp of the alpha 1 Na/K-ATPase locus coding sequence showed independence of the
synonymous/nonsynonymous ratio in the comparison within A. franciscana and
between A. franciscana and A. parthenogenetica, which fits the neutral model of
evolution. Since there were no previous studies on DNA polymorphism for other A.
franciscana genes, we also studied variability at the Actin 302 locus for
comparison. Both loci were amplified by reverse transcription-polymerase chain
reaction, and 20 sequences were obtained for each. This study shows that the
amplified region of the alpha 1 Na/K-ATPase gene is 3.5 times as polymorphic as
the Actin 302 gene and 2.9 times as heterozygotic. Interestingly, under a model
of neutral evolution, the data observed would be expected with a probability of
approximately 0.05, suggesting an excess of intraspecific variation of alpha 1
Na/K-ATPase with respect to Actin 302. Restriction fragment length polymorphism
studies show similar patterns of polymorphism along the approximately 41-kb span
of the alpha 1 Na/K-ATPase locus. Most of the nucleotide differences are linked
in a few haplotypes, although recombination events are also inferred from the
data. We propose a possible explanation for the high polymorphic levels at the
alpha 1 Na/K-ATPase locus which invokes positive selection acting tightly to the
locus in transiently isolated or semi-isolated subpopulations.
PMID- 10677847
TI - Multiple acquisition of methanogenic archaeal symbionts by anaerobic ciliates.
AB - Anaerobic heterotrichous ciliates (Armophoridae and Clevelandellidae) possess
hydrogenosomes that generate molecular hydrogen and ATP. This intracellular
source of hydrogen provides the basis for a stable endosymbiotic association with
methanogenic archaea. We analyzed the SSU rRNA genes of 18 heterotrichous
anaerobic ciliates and their methanogenic endosymbionts in order to unravel the
evolution of this mutualistic association. Here, we show that the anaerobic
heterotrichous ciliates constitute at least three evolutionary lines. One group
consists predominantly of gut-dwelling ciliates, and two to three, potentially
four, additional clades comprise ciliates that thrive in freshwater sediments.
Their methanogenic endosymbionts belong to only two different taxa that are
closely related to free-living methanogenic archaea from the particular
ecological niches. The close phylogenetic relationships between the endosymbionts
and free-living methanogenic archaea argue for multiple acquisitions from
environmental sources, notwithstanding the strictly vertical transmission of the
endosymbionts. Since phylogenetic analysis of the small-subunit (SSU) rRNA genes
of the hydrogenosomes of these ciliates indicates a descent from the mitochondria
of aerobic ciliates, it is likely that anaerobic heterotrichous ciliates hosted
endosymbiotic methanogens prior to their radiation. Therefore, our data strongly
suggest multiple acquisitions and replacements of endosymbiotic methanogenic
archaea during their host's adaptation to the various ecological niches.
PMID- 10677848
TI - Rapid expansion of microsatellite sequences in pines.
AB - Microsatellite persistence time and evolutionary change was studied among five
species of pines, which included a pair of closely related species (Pinus
sylvestris and Pinus resinosa) in the subgenus Pinus, their relative Pinus
radiata, and another closely related species pair (Pinus strobus and Pinus
lambertiana) in the subgenus Strobus. The effective population sizes of these
species are known to have ranged from the very small bottlenecks of P. resinosa
to vast populations of P. sylvestris. This background allowed us to place the
microsatellite evolution in a well-defined phylogenetic setting. Of 30 loci
originating from P. strobus and P. radiata, we were able to consistently amplify
4 in most of the these pine species. These priming sites had been conserved for
over 100 Myr. The four microsatellites were sequenced in the five species.
Flanking sequences were compared to establish that the loci were orthologous. All
microsatellites had persisted in these species, despite very different population
sizes. We found a recent microsatellite duplication: a closely related pair of
loci in P. strobus, where the other four species had just one locus. On two
independent occasions, the repeat area of this same microsatellite (locus RPS
105a/b) had grown from a very low repeat number to 15 or 17 in the last 10-25
Myr. Other parts of the same compound microsatellite had remained virtually
unchanged. Locus PR 4.6 is known to be polymorphic in both P. radiata and P.
sylvestris, but the polymorphism in the two species is due to different motifs.
The very large pine genomes are highly repetitive, and microsatellite loci also
occur as gene families.
PMID- 10677849
TI - Complete sequence of the mitochondrial DNA of the primitive opisthobranch
gastropod Pupa strigosa: systematic implication of the genome organization.
AB - The complete sequence (14,189 bp) of the mitochondrial DNA of the opisthobranch
gastropod Pupa strigosa was determined. The genome contains 13 protein, 2 rRNA,
and 22 tRNA genes typical of metazoan mtDNA. The Pupa mitochondrial genome is
highly compact and shows the following unusual features, like pulmonate land
snails: (1) extremely small genome size, (2) absence of lengthy noncoding regions
(with the largest intergenic spacer being only 46 nt), (3) size reduction of
encoded genes, and (4) many overlapping genes. Several tRNA genes exhibit bizarre
secondary structures with reduced T or D stems, and many tRNA genes have unstable
acceptor stems that might be corrected by posttranscriptional RNA editing. The
Pupa mitochondrial gene arrangement is almost identical to those of pulmonate
land snails but is radically divergent from those of the prosobranch gastropod
Littorina saxatilis and other molluscs. Our finding that the unique gene
arrangement and highly compact genome organization are shared between
opisthobranch and pulmonate gastropods strongly suggests their close phylogenetic
affinity.
PMID- 10677850
TI - An unusual form of purifying selection in a sperm protein.
AB - Protamines are small, highly basic DNA-binding proteins found in the sperm of
animals. Interestingly, the proportion of arginine residues in one type of
protamine, protamine P1, is about 50% in mammals. Upon closer examination, it was
found that both the total number of amino acids and the positions of arginine
residues have changed considerably during the course of mammalian evolution. This
evolutionary pattern suggests that protamine P1 is under an unusual form of
purifying selection, in which the high proportion of arginine residues is
maintained but the positions may vary. In this case, we would expect that the
rate of nonsynonymous substitution is not particularly low compared with that of
synonymous substitution, despite purifying selection. We would also expect that
the selection for a high arginine content results in a high frequency of the
nucleotide G in the coding region of this gene, because all six arginine codons
contain at least one G. These expectations were confirmed in our study of
mammalian protamine genes. Analysis of nonmammalian vertebrate genes also showed
essentially the same patterns of evolutionary changes, suggesting that this
unusual form of purifying selection has been active since the origin of bony
vertebrates. The protamine gene of an insect species shows similar patterns,
although its purifying selection is less intense. These observations suggest that
arginine-rich selection is a general feature of protamine evolution. The driving
force for arginine-rich selection appears to be the DNA-binding function of
protamine P1 and an interaction with a protein kinase in the fertilized egg.
PMID- 10677851
TI - Intragenomic variation within ITS1 and ITS2 of freshwater crayfishes (Decapoda:
Cambaridae): implications for phylogenetic and microsatellite studies.
AB - Intragenomic variation in ITS1 and ITS2 is known to exit but is widely ignored in
phylogenetic studies using these gene regions. The amount of variation in seven
crayfish species, including three populations of Orconectes luteus and two of
Procambarus clarkii, was assessed by sequencing 3, 5, or 10 clones from the same
individuals, for a total of 77 sequences. The ITS1 and ITS2 sequences reported
here are some of the longest known, with aligned lengths of 760 and 1,300 bp,
respectively. They contain multiple microsatellite insertions, all of which show
considerable intragenomic variation in the number of repeat elements. This
variation is enough to obscure phylogenetic relationships at the population
level, although relationships between species can be estimated. Given the
hybridization techniques used to locate microsatellites, multiple-copy regions
like ITS1 and ITS2 will be preferentially found if they contain microsatellites,
and in these cases the microsatellites will not behave as typical Mendelian
markers and could give spurious results.
PMID- 10677852
TI - The alpha-mannosidases: phylogeny and adaptive diversification.
AB - alpha-Mannosidase enzymes comprise a class of gylcoside hydrolases involved in
the maturation and degradaton of glycoprotein-linked oligosaccharides. Various
alpha-mannosidase enzymatic activities are encoded by an ancient and ubiquitous
gene superfamily. A comparative sequence analysis was employed here to
characterize the evolutionary relationships and dynamics of the alpha-mannosidase
superfamily. A series of lineage-specific BLAST searches recovered the first ever
recognized archaean and eubacterial alpha-mannosidase sequences, in addition to
numerous eukaryotic sequences. Motif-based alignment and subsequent phylogenetic
analysis of the entire superfamily revealed the presence of three well-supported
monophyletic clades that represent discrete alpha-mannosidase families. The
comparative method was used to evaluate the phylogenetic distribution of alpha
mannosidase functional variants within families. Results of this analysis
demonstrate a pattern of functional diversification of alpha-mannosidase paralogs
followed by conservation of function among orthologs. Nucleotide polymorphism
among the most closely related pair of duplicated genes was analyzed to evaluate
the role of natural selection in the functional diversification of alpha
mannosidase paralogs. Ratios of nonsynonymous and synonymous variation show an
increase in the rate of nonsynonymous change after duplication and a relative
excess of fixed nonsynonymous changes between the two groups of paralogs. These
data point to a possible role for positive Darwinian selection in the evolution
of alpha-mannosidase functional diversification following gene duplication.
PMID- 10677853
TI - Solvent accessibility and purifying selection within proteins of Escherichia coli
and Salmonella enterica.
AB - The neutral theory of molecular evolution predicts that variation within species
is inversely related to the strength of purifying selection, but the strength of
purifying selection itself must be related to physical constraints imposed by
protein folding and function. In this paper, we analyzed five enzymes for which
polymorphic sequence variation within Escherichia coli and/or Salmonella enterica
was available, along with a protein structure. Single and multivariate logistic
regression models are presented that evaluate amino acid size, physicochemical
properties, solvent accessibility, and secondary structure as predictors of
polymorphism. A model that contains a positive coefficient of association between
polymorphism and solvent accessibility and separate intercepts for each secondary
structure element is sufficient to explain the observed variation in polymorphism
between sites. The model predicts an increase in the probability of amino acid
polymorphism with increasing solvent accessibility for each protein regardless of
physicochemical properties, secondary-structure element, or size of the amino
acid. This result, when compared with the distribution of synonymous
polymorphism, which shows no association with solvent accessibility, suggests a
strong decrease in purifying selection with increasing solvent accessibility.
PMID- 10677854
TI - The glutamine synthetases of rhizobia: phylogenetics and evolutionary
implications.
AB - Glutamine synthetase exists in at least two related forms, GSI and GSII, the
sequences of which have been used in evolutionary molecular clock studies. GSI
has so far been found exclusively in bacteria, and GSII has been found
predominantly in eukaryotes. To date, only a minority of bacteria, including
rhizobia, have been shown to express both forms of GS. The sequences of
equivalent internal fragments of the GSI and GSII genes for the type strains of
16 species of rhizobia have been determined and analyzed. The GSI and GSII data
sets do not produce congruent phylogenies with either neighbor-joining or maximum
likelihood analyses. The GSI phylogeny is broadly congruent with the 16S rDNA
phylogeny for the same bacteria; the GSII phylogeny is not. There are three
striking rearrangements in the GSII phylograms, all of which might be explained
by horizontal gene transfer to Bradyrhizobium (probably from Mesorhizobium), to
Rhizobium galegae (from Rhizobium), and to Mesorhizobium huakuii (perhaps from
Rhizobium). There is also evidence suggesting intrageneric DNA transfer within
Mesorhizobium. Meta-analysis of both GS genes from the different genera of
rhizobia and other reference organisms suggests that the divergence times of the
different rhizobium genera predate the existence of legumes, their host plants.
PMID- 10677855
TI - Evolutionary history of the human endogenous retrovirus family ERV9.
AB - Several distinct families of endogenous retrovirus-like elements (ERVs) exist in
the genomes of primates. Despite the important evolutionary consequences that
carrying these intragenomic parasites may have for their hosts, our knowledge
about their evolution is still scarce. A matter of particular interest is whether
evolution of ERVs occurs via a master lineage or through several lineages
coexisting over long periods of time. In this work, the paleogenomic approach has
been applied to the study of the evolution of ERV9, one of the human endogenous
retrovirus families mobilized during primate evolution. By searching the GenBank
database with the first 676 bp of the ERV9 long terminal repeat, we identified
156 different element insertions into the human genome. These elements were
grouped into 14 subfamilies based on several characteristic nucleotide
differences. The age of each subfamily was roughly estimated based on the average
sequence divergence of its members from the subfamily consensus sequence.
Determination of the sequential order of diagnostic substitutions led to the
identification of four distinct lineages, which retained their capacity of
transposition over extended periods of evolution. Strong evidence for mosaic
evolution of some of these lineages is presented. Taken altogether, the available
data indicate that the possibility of ERV9 still being active in the human
lineage can not be discarded.
PMID- 10677856
TI - Evidence for genomic duplication of the glutathione transferase A3 gene in genus
Rattus.
PMID- 10677857
TI - Neuromuscular disorders in childhood: a descriptive epidemiological study from
western Sweden.
AB - A retrospective epidemiological study of neuromuscular disorders was carried out
in children born between 1979 and 1994 in western Sweden. The purpose was to
determine overall and specific prevalences, overall cumulative incidence and
birth incidences of selected disorders. Cases were ascertained from 12 different
sources and medical records, investigations and diagnosis were reviewed. We found
a point prevalence in the population < 16 years of age of 63.1 x 10(-5) for all
neuromuscular disorders and 53.1 x 10(-5) for inherited neuromuscular disorders.
The point prevalence in children of school age was even higher. We found a higher
occurrence of hereditary motor and sensory neuropathy, congenital myopathies and
mitochondrial encephalo-myopathy, a slightly lower occurrence of Duchenne
muscular dystrophy and spinal muscular atrophy and equal occurrence of myotonic
dystrophy compared to previous studies in other countries. We conclude that
neuromuscular disorders are more common in childhood than has previously been
reported.
PMID- 10677858
TI - Autosomal recessive hereditary neuropathy with focally folded myelin sheaths and
linked to chromosome 11q23: a distinct and homogeneous entity.
AB - We describe a six generation Saudi kindred, with a recessive hereditary motor and
sensory neuropathy (HMSN). Four individuals were affected including two children
(a boy and a girl) and a 23-year-old man. The fourth (a female) died at the age
of 14 years. Onset of the disease was early (< 2 years) and the clinical and
neurophysiological features were, generally, quite similar to those of an Italian
family linked to chromosome 11q23. The peculiar pathologic pattern was irregular
and redundant loops associated with folding of the myelin sheaths. The genetic
study confirmed linkage to chromosome 11q23 and refined the location of the gene
between D11S1311 and D11S917, a 3.3 cM region. These findings support the
existence of a homogeneous and distinct entity within the form of HMSN associated
with focally folded myelin sheaths.
PMID- 10677859
TI - Muscle membrane-skeleton protein changes and histopathological characterization
of muscle-eye-brain disease.
AB - Muscle-eye-brain disease belongs to congenital muscular dystrophies with central
nervous system abnormalities. The etiology of MEB is still unknown, but abnormal
immunoreactivity for laminin-2 has been reported. To evaluate disease progression
in muscle tissue, 32 biopsy specimens from 17 muscle-eye-brain patients were
analysed. The samples of four patients were studied by immunohistochemical
techniques and by quantitative Western blotting. The samples showed a great
variation in the muscle pathology. Regenerative fibers and mild fiber size
variation were present in over 60%. At infancy, necrotic and regenerative fibers
were common, while fat infiltration was the most prominent finding in the age
group over five years. In quantitative studies, the amount of laminin alpha 2
chain was clearly reduced to 10-20% of normal. In contrast, laminin beta 2 chain
was overexpressed in the Western blotting studies. These findings may reflect a
yet unidentified primary disturbance in the basement membrane composition and
function.
PMID- 10677860
TI - Two distal mutations in the gene encoding emerin have profoundly different
effects on emerin protein expression.
AB - Emerin, the product of the gene responsible for X-linked Emery-Dreifuss muscular
dystrophy (EDMD), has a ubiquitous tissue distribution and is localised to the
nuclear envelope. We present here the relationship between emerin protein
expression, nuclear localization and clinical phenotype for two distal mutations
identified in unrelated EDMD patients. The first mutation predicts the
replacement of the last eight amino acids of emerin with the addition of 101
amino acids, but no emerin expression is detected. The second mutation, 35 bp
upstream from the first mutation, deletes six amino acids from the transmembrane
region, but in this case emerin expression is seen. Emerin from this second
patient is expressed at reduced levels, mistargeted and has altered biochemical
properties compared to wild type emerin. In both cases the clinical phenotype was
similar to patients with typical null mutations. We discuss these data in
comparison with previous reports of other C-terminal mutations in the emerin gene
and suggest that the efficiency of emerin's nuclear membrane localization is
affected by the hydrophobicity (and possibly length) of its transmembrane region,
and a longer C-terminal tail prevents nuclear localization.
PMID- 10677861
TI - Different effects of mexiletine on two mutant sodium channels causing
paramyotonia congenita and hyperkalemic periodic paralysis.
AB - Effects of the antiarrhythmic and antimyotonic drug mexiletine were studied on
two sodium channel mutants causing paramyotonia congenita (R1448H) and an overlap
paramyotonic and hyperkalemic paralytic syndrome (M1360V). Channels were
expressed in human embryonic kidney cells and studied electrophysiologically,
using the whole-cell patch-clamp technique. Compared to the wild-type, channel,
both mutants showed alterations of inactivation, i.e. slower inactivation, left
shift of steady-state inactivation and faster recovery from inactivation.
Mexiletine caused a significantly larger use-dependent block of the R1448H mutant
when compared to M1360V and wild-type channels. This can be explained by a
prolonged recovery from mexiletine block as observed for R1448H channels, since
the affinity of mexiletine for the inactivated state was similar for all three
clones. The use-dependent block of sodium channels by mexiletine reduces
repetitive series of action potentials and therefore improves muscle stiffness in
myotonic patients. The enhanced use-dependent block as seen with R1448H may
explain the extraordinary therapeutic efficacy of mexiletine in most patients
with paramyotonia congenita.
PMID- 10677862
TI - Effects of aerobic training on lactate and catecholaminergic exercise responses
in mitochondrial myopathies.
AB - The aim of this study was to evaluate the effects of an aerobic training program
on the metabolic and sympathetic responses to exercise in 12 patients with
mitochondrial myopathies. A 10-week course of aerobic training, consisting of
supervised exercise every other day on an electrically braked pedal-rate bicycle
ergometer was prescribed to each patient and four healthy controls. Venous
lactate, epinephrine (EP) and norepinephrine (NEP) levels were assessed at
baseline and after the aerobic training by means of constant-workload exercise
performed at near lactate threshold (LT). In patients, a decrease in exercise
peak values, significant for lactate (-38.6%, P < 0.01) but not for
catecholamines (EP: -26.0%, NEP: -22.1%) was observed after training, findings
confirmed by the lactate/EP and lactate/NEP area ratios. The results show that
lactate accumulation during exercise is decreased after aerobic training in
mitochondrial myopathies and that the effect is partially dissociated from the
catecholaminergic response. This in turn suggests that the lactate decrease can
be explained, at least in part, by the improved muscle oxidative metabolism
consequent to the proposed training program.
PMID- 10677863
TI - Dermatomyositis and Whipple's disease.
AB - A 14-year-old boy presented with a 3-year history of a skin rash typical of
juvenile dermatomyositis, and a 2-month history of mild proximal weakness,
myalgia, and weight loss. A quadriceps biopsy showed perifascicular fibre
atrophy, focal necrosis and regeneration, immunohistochemical labelling for HLA-1
on the surface of the fibres, and focal C5-9 deposition in capillaries.
Macrophages with diastase-resistant, PAS-positive cytoplasm were present.
Ultrastructural studies showed electron dense and membranous debris. The
patient's symptoms responded to intravenous immunoglobulin and oral prednisolone.
Four months after discontinuing prednisolone, the patient developed cardiac
failure, ventricular tachycardia, and a recurrence of his rash. The 16S ribosomal
RNA specific for Tropheryma whippelii was identified by polymerase chain reaction
(PCR) analysis in skeletal and cardiac muscle. The myalgia and skin rash
responded to prednisolone and oral co-trimoxazole, and the tachycardia is
controlled by oral verapamil. This patient appears to have a novel association of
juvenile dermatomyositis and Whipple's disease.
PMID- 10677864
TI - An Italian family with Ala-47 transthyretin mutation associated with
cardiomyopathy and polyneuropathy.
AB - We describe two Italian first cousins with familial amyloidotic polyneuropathy
associated with transthyretin variant consisting of the substitution of alanine
for glycine at codon 47 (TTR Ala-47), from a family with a history of cardiac
failure. The 40-year-old patient presented with autonomic dysfunction and the 44
year-old cousin with congestive heart failure. Both developed sensorimotor and
autonomic polyneuropathy. Since a similar clinical picture has been described in
another Italian family, the cardiac involvement must be regarded as a salient and
early feature of the TTR Ala-47 mutation.
PMID- 10677865
TI - Single large-scale mitochondrial DNA deletion in a patient with encephalopathy,
cardiomyopathy, and prominent intestinal pseudo-obstruction.
AB - We studied a 62 year-old woman with a clinical phenotype characterized by
encephalopathy, restrictive cardiomyopathy, and prominent intestinal pseudo
obstruction. Muscle morphology showed ragged red fibres with ultrastructurally
abnormal mitochondrial whereas muscle respiratory chain was normal. Molecular
genetics revealed the 'common deletion' in mtDNA, which represented 40% of total
mtDNA. These data expand and confirm the wide clinical spectrum of mitochondrial
disorders associated with single large-scale mtDNA deletions.
PMID- 10677866
TI - Identification of homozygous and heterozygous dy2J mice by PCR.
AB - The dystrophia muscularis dy2J/dy2J mouse is an animal model for one form of
human congenital muscular dystrophy. A point mutation in the gene coding for the
laminin-2 alpha 2 chain leads to the expression of a truncated, partially
functional protein. We developed a simple assay for the detection of the dy2J
allele, which contains a new NdeI restriction site. Genomic DNA was prepared from
animals of known status and amplified by PCR. The digestion of the PCR product
with the restriction enzyme resulted in characteristic profiles. Then, this
technique was used to identify heterozygous mice among unaffected animals of
unknown status. Subsequently, the heterozygous genotype of these mice was
confirmed by the birth of dystrophic offspring after mating. This technique
allows the detection of the dy2J allele in heterozygous and homozygous animals at
any age.
PMID- 10677867
TI - Amyotrophic lateral sclerosis: copper/zinc superoxide dismutase (SOD1) gene
mutations.
AB - Mutations of the SOD1 gene, encoding the enzyme copper/zinc superoxide dismutase,
have been identified in around 20% of patients with familial amyotrophic lateral
sclerosis (ALS), and also in patients with apparently sporadic ALS. The table
documents the mutations identified and published to date, and references clinical
and pathological descriptions of the patients and families with individual
mutations. The table includes 63 different mutations of SOD1 at 43 codons, three
intronic sites, and two in the 3' untranslated region. Most of the mutations are
heterozygotes, with autosomal dominant inheritance, but a small number of
individuals appear to be sporadic, or are homozygotes with autosomal dominant
recessive inheritance.
PMID- 10677868
TI - 5th Workshop of the European CMT Consortium, 69th ENMC International Workshop:
therapeutic approaches in CMT neuropathies and related disorders 23-25 April
1999, Soestduinen, The Netherlands.
PMID- 10677869
TI - Ten years of ENMC--from a patients' initiative to a successful European research
institution: the story of the European Neuromuscular Centre.
PMID- 10677870
TI - Neuromuscular disorders: gene location.
PMID- 10677871
TI - Mitochondrial encephalomyopathies: gene mutation.
PMID- 10677872
TI - Introduction: community action research and the prevention of alcohol problems at
the local level.
AB - Many community action projects from around the world exist to reduce alcohol
problems at the local level. The role of research within this international
movement is discussed within this introduction for the entire special issue on
community action research in alcohol problem prevention. Previous community
prevention programs have utilized a variety of prevention strategies: (a) an
educational approach which focuses on changing behavior through changes in
knowledge, attitudes, and information; and (b) an environmental approach which
focuses on changing behavior through changes in the social and economic systems
within a community. Many projects have used both approaches. This special issue
provides a current overview of many types of community action projects from
different countries and summarizes what has been learned to date from these
experiences.
PMID- 10677873
TI - To prevent alcohol problems in Europe by community actions--various national and
regional contexts.
AB - The European transformation during the 1990s, concerning political, economic,
social and cultural changes, has made alcohol policy in many countries very
fragile and uncertain because of new social and economic conditions and
decreasing power of national governments. On this background, regions,
municipalities, nongovernmental organizations and the civic society are to play a
more prominent role in the European alcohol policy arena. In December 1997 the
first European research and evaluation symposium on community action alcohol
programs was held in Malmo, Sweden. The themes were: Research-based evaluation of
community action programs; The interaction between local, national, and European
prevention strategies; Local programs in schools, workplaces, health sectors,
primary health care, and other community contexts; The role of citizens'
movements, consumer organizations, women's groups, and other voluntary
organizations; Local political action. This paper is the first attempt to
summarize the similarities and differences in the programs presented at the
symposium.
PMID- 10677874
TI - Reducing alcohol problems through community action research projects: contexts,
strategies, implications, and challenges.
AB - Community-based action research projects may include a number of challenges. The
secular context may impede a project; for example, reducing aggregate rates of
drinking-related problems may involve curtailing very popular high-risk drinking
occasions. These projects may also embrace important but unrealistic goals,
require matching competing goals emerging from multifoci project teams, or
involve convoluted funding arrangements. Attention to team development, priority
setting, and project design and evaluation issues is essential. Many projects
downplay conceptual issues, such as understanding the nature of communities,
organizations, systems, their operation, and social change and prevention models.
Focus populations, community members and leaders, change agents team members,
funding agencies, and policymakers can benefit from these projects.
PMID- 10677875
TI - A decade of community action research.
AB - The aim of this paper is to reflect on the past decade of research and community
action on alcohol and especially on some of the presentations given in the three
previous international meetings on community action: in Ontario 1989, San Diego
1992, and Greve Florence 1995. The projects reported on are diverse, reflecting
the different cultures represented, but there are also common strands. Among
these common strands is the growing consensus that at the heart of successful
evaluated community action projects is a process of reciprocal and respectful
communication: between different community sectors and also between the community
and researchers. While there is increased acknowledgment of the knowledge
community sectors bring to planning and implementing community action, there is
also an increasing focus on the role of the researcher in providing research
based knowledge to facilitate the development of effective community strategies
to reduce alcohol-use-related harm. This is in contrast to a research role which
emphasizes only outcome evaluation. Another development apparent through the
years covered in the international meeting is the use of more naturalistic
approaches to evaluation in acknowledgment that experimental design may not be
feasible or scientifically appropriate for the evaluation of community action
projects.
PMID- 10677876
TI - Institutionalization of community action projects to reduce alcohol-use related
problems: systematic facilitators.
AB - This article reviews papers from a recent conference on community action research
in order to identify factors that contribute to long-term maintenance,
sustainability, or institutionalization of community project interventions. The
descriptions of long-term outcomes and aftereffects of projects that emerged in
the conference are valuable because relatively few instances of
institutionalization have been documented in the scientific literature. After a
general theoretical discussion of institutionalization in communities, the
article identifies characteristics of successful community action programs that
outlived their original funding. These characteristics include honoring community
values and cultural relevance, cultivating key leader support, and utilizing
indigenous staff. They also include developing local resources, maintaining
flexibility, and leveraging prior success. The paper concludes by noting that
aiming for policy and structural changes is a goal for an institutionalization of
measures positively affecting desired health outcomes, even if the programs which
created them are not themselves sustained.
PMID- 10677877
TI - Community action research: who does what to whom and why? Lessons learned from
local prevention efforts (international experiences).
AB - This paper describes lessons learned about community action research, drawing
upon papers written and presented at a recent international conference on
community action research and the prevention of alcohol and other drug problems.
Projects reflected both action and evaluation research traditions and focused on
a variety of issues from moderation of drinking to alcohol-related violence, and
on range of target populations from youth to specific ethnic groups. The
interventions described ranged from policy-based prevention to education and
training and to secondary prevention and treatment. Lessons identified in the
papers are discussed within three broad areas: the community targeted for change;
the implementation of community projects; and community action research projects
generally. The common lessons emerging from these diverse projects provide useful
lessons on which to base future progress in community action research.
PMID- 10677878
TI - The Finnish case: community prevention in a time of rapid change in national and
international trade.
AB - This article looks at the present Finnish situation in planning and development
of community-level prevention of alcohol and drug problems, and the experiences
gained so far. Results from the first extensive evaluated project of this kind in
Finland, the Lahti Project, and the program and evaluation plans for a new
project in the Helsinki metropolitan area are also described. It is argued that
in the present Finnish context there is need for detailed theoretical and well
measured evaluation on why the results of community-based prevention are or are
not achieved.
PMID- 10677879
TI - Alcohol carousel and children's school drawings as part of a community
educational strategy.
AB - Within a community action research program, messages for the community population
can be conveyed through already existing channels (newspapers, magazines, TV,
radio) or special tools can be created. As part of the Rifredi Health District
(16,900 inhabitants), Florence, Italy, Community Alcohol Action Research Project,
5,500 alcohol carousels (translated and adapted from the Stockholm carousel) were
distributed during 1996 in the project's area where they were freely available.
Two samples, one of a consumers' association (response rate 26%) and the other of
school parents, employed a questionnaire. A few local key people underwent a
qualitative interview. In all circumstances the carousel proved to be
understandable, useful, and able to elicit discussions about alcohol issues. In
1996-97, after a 2-year training program in communication skills and alcohol
prevention, 13 teachers in local preschools, elementary schools, and middle
schools planned and implemented a health education program on the issues of
alcohol and food. One outcome was nine drawings produced by the school children.
The drawings were exhibited in some schools and supermarkets, and were hung in
city buses.
PMID- 10677880
TI - Community action to reduce rural drink and drive crashes in New Zealand: adapting
approaches in dynamic environments.
AB - This paper discusses the evolution of a two-and-a-half year pilot community
action project aimed at developing strategies to reduce alcohol-use-related
crashes in a rural police district in New Zealand. Formative evaluation aimed to
assist an intersectoral coordinating group identify and implement strategies.
Initially the idea was to establish community-based committees to mobilize on
drinking and driving around the district. However, it became clear that the
original concept impeded action. The focus was changed to provide more support to
strengthen existing initiatives, particularly those relating to police traffic
enforcement and drinking environments. This helped give the project renewed life
and direction. The paper focuses on process, organizational, and external
community issues affecting the project and the use of formative evaluation to
assist the project to respond and adapt to dynamic circumstances.
PMID- 10677881
TI - Community-identified alcohol issues in the Mexican American community: research
design and utilization.
AB - This article describes a community-based study, Alcohol Outlet Density and
Mexican American Youth Violence, funded by the California Wellness Foundation-
Violence Prevention Initiative to the prevention Research Center in Berkeley,
California. The study was conducted in three northern California cities in 1993
1996. The focus is on the inclusionary planning process in designing and
implementing the study. Community members were an integral part in the
identification of study questions. As a result, the findings of the study are
relevant to community activists in advocating alcohol-related policies. The need
for more utilization-based community studies is emphasized.
PMID- 10677882
TI - Time trends in alcohol habits. Results from the Kirseberg project in Malmo,
Sweden.
AB - This paper reports on a pilot demonstration to implement an alcohol consumption
reduction project in the community of Kirseberg, located in the city of Malmo,
Sweden. The objective is to present data on time trends in alcohol use habits and
alcohol-use-related problems in the Kirseberg population and to discuss potential
effects of the alcohol prevention activities. It was possible to implement an
alcohol consumption prevention community program successfully. The analysis of
time trends in alcohol use habits and alcohol-use-related problems was, however,
mainly inconclusive, but indicated a decrease in alcohol consumption and alcohol
use-related problems among young and middle-aged men.
PMID- 10677883
TI - Malczyce, Poland: a multifaceted community action project in eastern Europe in a
time of rapid economic change.
AB - The major focus of this paper is the sustainability of a one-year demonstration
project on drug misuse prevention, which was implemented in a local community
affected by acute economic crisis and high unemployment. The project was
initiated by the Institute of Psychiatry and Neurology, and supported by the
European Commission. The primary goal of the project was to demonstrate that
community-based prevention is possible and feasible within the context of current
transitions in Poland. Its major outcome was a community prevention package
consisting of a number of booklets and videos to assist other communities in
their prevention efforts. Experiences from this study suggest that factors
contributing to the sustainability of a community prevention project can be
identified and emphasized through simple analysis of community surveys, as well
as focus group discussion.
PMID- 10677884
TI - Cardiovascular effects of odors.
AB - Several occupational and residential settings can expose both normal and
sensitive human subjects to odors and irritants. These settings include intensive
agricultural operations housing swine and poultry, cigarette-smoke-filled bars,
landfills and manufacturing processes. The literature suggests that adverse
sensory reactions to strong odors and irritants may lead to the release of
catecholamines and stress hormones. Physiological and biochemical measurements
related to cardiovascular risk, e.g., blood pressure, heart rate, high-density
lipoprotein (HDL) cholesterol level and serum triglyceride level, may be altered
as a result of exposure to odor and irritant-induced release of catecholamines.
Further work in the form of field studies and chamber exposure protocols is
required to determine whether the physiological and biochemical changes observed
to date represent an increase in cardiovascular risk, or are reversible changes
within the normal homeostatic range.
PMID- 10677885
TI - Agency for Toxic Substances and Disease Registry's 1997 priority list of
hazardous substances. Latent effects--carcinogenesis, neurotoxicology, and
developmental deficits in humans and animals.
AB - In support of Superfund re-authorization legislation, the Division of Toxicology
of the Agency for Toxic Substances and Disease Registry (ATSDR) prepared a
chemical-specific consultation document for Congress that identified those
chemicals with carcinogenic, neurological, or developmental adverse effects
having a latency period longer than 6 years. The review was limited to the top 50
substances listed on ATSDR's 1997 Priority List of Hazardous Substances (Priority
List). Among the top 50 chemicals, a review of the technical literature indicated
that 38 (76%) were classified as "reasonably anticipated," "possibly," or
"probably" capable of causing cancer in humans, based either on human and animal
data. Eight chemicals (16%) had well-established cancer latency periods in humans
of 6 years or more following exposure. Three substances (6%)--arsenic, creosote,
and benzidine--had data indicating latency periods longer than 6 years. The
technical literature review likewise confirmed the potential for neurological and
developmental effects with a latency of 6 years. Twenty-seven (54%) of the top 50
substances caused acute and/or chronic neurotoxic effects; a number of these also
caused neurological effects that persisted beyond 6 years (or the equivalent in
animal studies) such as: behavioral problems, neurological deficiencies, reduced
psychomotor development, cognitive deficiencies, and reduced IQ. Twenty-eight
substances (56%) caused adverse developmental effects in offspring of exposed
individuals or animals including increased fetal and infant mortality, decreased
birth weights and litter sizes, and growth delays. Latency periods for related
chemicals are expected to be similar due to structural and toxicological
similarities.
PMID- 10677886
TI - [Misconduct and fraud in science].
PMID- 10677887
TI - [Current aspects of handedness].
AB - Handedness is one example of many forms of behavioural lateralization seen in
humans. Left-handedness has existed in a small subset of the human population,
approximately 8%, since the origin of man. The incidence of left-handedness is
usually reported to be consistent among human populations. Sinistrality is more
common in males than in females. A vast range of testing techniques have been
used to assess handedness. There are preference and performance tests. Writing
hand and self-report are two of the most popular techniques. There is a strong
evidence that the dominance of language functions in the cerebral cortex is
different in left-handed from that in right-handed people. An understanding of
handedness may provide valuables clues as to how the brain becomes organized the
way it is. Several theories have been advanced over the years to explain the
genesis of handedness and, in particular, left-handedness. Theories have ranged
from genetic models to socio-cultural theories. Other authors suggested a
pathological origin of left-handedness in man. Left-handedness runs in families
and adoption studies suggests a genetic rather than an environmental origin.
However, monozygotic twins appear to be substantially discordant. A polygenetic
explanation which takes environmental influences into consideration is probably
called for.
PMID- 10677888
TI - Twenty years of the ethics committee at the medical faculty of the University of
Vienna. An interim report.
AB - The organisation and assessment procedures of the ethics committee of the
University of Vienna medical faculty are described. Data concerning the work of
the committee from 1993 through to 1997 are given in detail. Finally, the results
of a survey among physicians on the acceptance of the committee's work are
presented. In conclusion, the workload of an ethics committee in a large medical
faculty can only be handled by efficient management of assessment procedures.
However, it is difficult to achieve sufficient acceptance in a field governed by
various interests.
PMID- 10677889
TI - Treatment of hairy cell leukemia with cladribine (2-chlorodeoxyadenosine).
AB - Hairy cell leukemia is a rare lymphoproliferative disorder resistant to
conventional chemotherapeutic agents. Recently, the purine analogue cladribine (2
chlorodeoxyadenosine, 2-CdA) was introduced for the treatment of this disease. We
report on 14 patients with hairy cell leukemia who were treated with 2-CdA at our
department between 1993 and 1997. The patients received a single cycle of 2-CdA
at a dose of 0.07 or 0.09 mg/kg/day by continuous infusion, over a seven-day
period. Five patients were previously untreated, while the others had received
prior treatment with interferon-alpha (seven patients), interferon-alpha and
splenectomy (one patient) or interferon-alpha, splenectomy and pentostatin (one
patient). Six patients achieved complete remission, three a good partial response
and three partial remission. Two patients did not respond to treatment and one of
them died from septicemia in aplasia. Relapse of the disease occurred in two
patients. Side effects such as fever (WHO grade 2) and/or neutropenia (WHO grade
4) were noted in eight patients. Thus, 2-CdA is an effective treatment of hairy
cell leukemia that can induce long lasting remissions in both, previously treated
and untreated patients.
PMID- 10677890
TI - The role of local anaesthetic inhalation during premedication before
bronchoscopy.
AB - In a prospective randomized study, the efficacy of local anaesthetic inhalation
during premedication before bronchoscopic examination was evaluated. Eighty
patients with chronic nonproductive cough were inhaling either nebulized
anaesthetics (10 ml of 1% trimecain; 40 patients--group A) or an isotonic
chlorine solution (40 patients--group B). This was followed by topical
anaesthesia using spray and laryngeal syringe. Comparing the score of cough and
episodes of gagging, the inhalation of local anaesthetics appeared to make the
procedure slightly more comfortable for some patients. Additional anaesthesia was
less frequently needed in group A than in group B (12 vs. 19 patients). However,
none of the observed differences reached statistical significance. In conclusion,
the inhalation of local anaesthetics at the beginning of premedication before
bronchoscopy was not confirmed as a useful method that made the examination more
comfortable for patients with chronic non-productive cough, but did produce a
moderately beneficial effect in some of them.
PMID- 10677891
TI - [Hormone replacement therapy with 17 beta-estradiol dydrogesterone: results of a
3-month open-label study].
AB - Hormone replacement therapy is well known for its beneficial effects on
climacteric symptoms and is also used for the prevention of osteoporosis. In a
prospective open label study we evaluated the efficacy and safety of hormone
replacement therapy with 17 beta estradiol dydrogesterone (Femoston, 17 beta
estradiol/continuously and dydrogesterone/sequentially). We observed 704 women
who were treated with 17 beta estradiol-dydrogesterone over three months. 448 of
the women previously had not used hormone replacement therapy, 224 women had been
treated with a different hormone replacement therapy before they were entered
into the study; for 20 women this information was not available. The physicians
were asked to assess the severity of climacteric symptoms at baseline and after
three months of hormone replacement therapy. In addition, the following
parameters were evaluated before and at the end of the study: blood pressure,
total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, blood
glucose, alkaline phosphatase and gamma glutamyltransferase. Twelve women did not
tolerate 17 beta estradiol-dydrogesterone and therefore dropped out of the study.
Climacteric symptoms clearly improved after treatment with 17 beta estradiol
dydrogesterone. During our open label prospective study, a significant decrease
in blood pressure and serum levels of total cholesterol, LDL cholesterol and the
LDL/HDL ratio were observed, whereas serum levels of HDL cholesterol increased
significantly. Surprisingly, triglyceride levels also decreased significantly.
Serum levels of alkaline phosphatase decreased significantly in women who had
received a different hormone replacement therapy before they took 17 beta
estradiol-dydrogesterone. We conclude that hormone replacement therapy with 17
beta estradiol-dydrogesterone is highly effective and well tolerated. Hormone
replacement therapy with 17 beta estradiol-dydrogesterone appears to have a
positive effect on blood pressure and the serum lipid profile. We therefore
hypothesise that prolonged treatment with 17 beta estradiol-dydrogesterone may
reduce morbidity and mortality secondary to cardiovascular diseases.
PMID- 10677892
TI - [Austrian Society for Lung Diseases and Tuberculosis: Consensus on diagnosis and
therapy of bronchial asthma in adults. Revised draft 1999].
PMID- 10677893
TI - Minimal residual disease, its detection and significance in hairy-cell leukemia.
AB - As minimal residual disease (MRD) is considered the detection of hairy cells
(HCs) in a patient with hairy cell leukemia (HCL) in complete remission with the
absence of detectable HCs by routine morphology of peripheral blood, aspirates
and bone marrow core sections, using more sensitive methods of identification as
immunohistological staining or polymerase chain reaction (PCR) to detect
immunoglobulin heavy chain genes rearrangement. Various monoclonal antibodies
(MoAbs) as CD20, DBA.44, B ly-7, HC2, CD25 and CD11c have been applied using
immunological staining. There is no standardized technique for identification of
MRD. According to the technique used the MRD has been detected in 13% to 100% of
patients in complete remission (CR). It may be concluded that many patients, if
not all, in stable CR may have residual HCs. Whether MRD will have impact on
early relapse or on long term outcome, or whether patients in CR with persistent
MRD will remain so, is a matter of a longer follow-up.
PMID- 10677894
TI - The influence of dimethoxybenfluron on biochemical and haematological parameters
in rabbits.
AB - The influence of repeated i.v. administration of dimethoxybenfluron (NO-1-B) (12
or 24 mg base/kg once weekly, 10 weeks) on biochemical and haematological
parameters were studied in rabbits in vivo. No significant changes were mostly
found in the serum ion levels between the dimethoxybenfluron and the control
groups, as well as in most of other biochemical parameters (including total
protein and albumin levels). Nevertheless, the lower dose of dimethoxybenfluron
caused an increase in the glucose level. Furthermore, no significant changes were
mostly present also in haematological parameters in the dimethoxybenfluron groups
of rabbits (a mild decrease in thrombocytes and leucocytes). The results of our
study support an assumption of good tolerance of dimethoxybenfluron from the
viewpoint of its influence on biochemical and haematological parameters in
rabbits and may be considered of importance for a possible therapeutic use of the
derivatives.
PMID- 10677895
TI - Is factor V Leiden a risk factor for fetal loss?
AB - A successful pregnancy is dependent on the development of adequate placental
circulation. The abnormalities of placental vasculature may result in a number of
gestational pathologies, including fetal loss. The aim of our study was to
determine whether women with f V Leiden are at an increased risk of pregnancy
loss. For this purpose we assessed three groups of women. In a prospective group
we examined 30 females with spontaneous abortions for f V Leiden. In a
retrospective group we assessed the frequency of abortions in 80 women (172
pregnancies) with f V Leiden (72 heterozygous, 8 homozygous) from 57 unrelated
families. In a control group we evaluated the frequency of abortions in 45 women
without f V Leiden. Factor V Leiden was found in 3% of women in the 1st group.
Fetal loss occurred in 10% of women in the 2nd group and in 9% in the 3rd group.
Factor V Leiden was not found to be a risk factor for fetal loss in our study
group.
PMID- 10677896
TI - Serum soluble adhesion molecules (sICAM-1, sVCAM-1, sE-selectin) and neopterin in
patients with Sjogren's syndrome.
AB - Sjogren's syndrome is a systemic autoimmune disease characterized by focal
lymphocytic infiltration of the salivary and lacrimal glands. Expression and up
regulation of adhesion molecules and activation of cellular immune system is
essential for the migration of inflammatory cells into tissues. Soluble forms of
adhesion molecules sICAM-1, sVCAM-1, sE-selectin and neopterin were analyzed in
serum of 17 patients with primary Sjogren's syndrome and 11 patients with
secondary Sjogren's syndrome together with 26 age-matched healthy blood donors.
There were significantly higher serum concentrations (mean +/- 1SD) of sICAM-1
(362.0 +/- 67.9 ng/ml, p < 0.001), sE-selectin (78.7 +/- 28.1 ng/ml, p < 0.001)
and neopterin (17.9 +/- 6.4 nmol/l, p < 0.001) in primary Sjogren's syndrome
patients in comparison to control group (sICAM-1: 128.3 +/- 46.9 ng/ml, sE
selectin: 46.3 +/- 39.5 ng/ml, and neopterin: 7.6 +/- 2.3 nmol/l). Sera from
patients with secondary Sjogren's disease contained significantly higher levels
of sICAM-1 (356.0 +/- 62.4 ng/ml, p < 0.001), sE-selectin (65.5 +/- 27.0 ng/ml, p
< 0.05), and neopterin (18.8 +/- 9.8 nmol/l, p < 0.001) in comparison with
control group. There were no significant differences between patients with
primary and secondary Sjogren's syndrome in any parameters tested. No
statistically significant differences in serum levels of sVCAM-1 were found
either in patients with primary or secondary SS compared to control group.
PMID- 10677897
TI - Tumours and tumour-like lesions of scapula.
AB - A retrospective study of 68 cases of tumours and tumour-like lesions related to
the scapula, included in the registry of the Bone Tumour Reference Centre at the
Institute of Pathology/University Clinics, Basle, has been carried out. Each case
was evaluated for lesion entity, activity and location, age and sex of the
patient, and, in 49 files with available radiographic documentation (mostly plain
films), for radiologic appearance, with the aim to predict the histologic
diagnosis or at least the correct dignity of the lesion. Statistically most
frequent were cartilaginous tumours. More than 1/3 of all cases were
osteochondromas, which demonstrated mostly a typical appearance. They were
encountered predominantly in the first 3 decades in males and were located most
often in the body of the scapula. 1/4 of all cases were chondrosarcomas, which
were prevailing in the 4th-7th decades, but were occasionally found at a younger
age too. Chondrosarcomas were located mainly at the lateral scapular margin over
the inferior angle and in the acromion and coracoid process and their appearance
ranged from typical to falsely benign. 1/3 of the cases represented a number of
other benign and malignant histological entities.
PMID- 10677898
TI - Surgery for bullous emphysema.
AB - The present indications for surgery are mainly large or increasing bullae that
result in compression of apparently good lung tissue, and the complications of
bullous diseases such as pneumothorax. The results of local resection of
localized giant bullae are dramatic. The resection of small bullae generally has
little effect on lung function. Lobectomy should not be done until bullae have
been removed locally and the remaining lung has been tested by positive
ventilation. The indications for the resection of large bullae in the presence of
diffuse emphysema require very careful individual study. Pulmonary function tests
are mandatory but computed tomography is the single most useful method of
assessing the extent of the bullous disease and the underlying lung disease. If
the underlying lung is diffusely cystic then any surgical treatment is palliative
only.
PMID- 10677899
TI - [Changes in visual function in myopia 12 months after photorefractive
keratectomy].
AB - 1. 110 myopes undergoing photorefractive keratectomy (PRK) with refraction from
0.25 D to -12.0 D were divided into 4 groups: A: upto -2.75 D, B: -3.0 D to -5.75
D, C: -6.0 D to -8.75 D and D: -9.0 D to -12.0 D. BCVA using the computerized
method with Landolt rings and CS using an adjustment method with ascendant and
descendent approach to threshold contrast adaptation on a computerized system of
the Contrast sensitivity 8010 type were examined in patients before and 1 year
after PRK. 20 emmetropes of the same median age were evaluated as a control
group. 2. Preoperative BCVA and CS in myopes of all four groups was significantly
lower (p < 0.05 az p < 0.001), compared to controls. Decrease of functions was
proportional to refraction. 3. With increasing refraction less patients were
within +/- 0.5 D and +/- 1.0 after surgery. 4. Twelve months after PRK, BCVA in
the group A reached the level of controls, CS in the same time interval was equal
to control even in groups A and B. 5. According to results of our study, PRK is a
suitable method for myopia upto -6.0 D.
PMID- 10677900
TI - [Hereditary occurrence of deep cavities in the optic nerve associated with Best's
disease].
AB - The authors present a pedigree where in three generations in male members deep
excavations of the optic discs along with Best's disease of the centres in a
variable form were recorded. The heredity is autosomal dominant. Retinal changes
conditioned by defects of the pigmented epithelium reduce vision to a maximum of
6/60. The anomaly is associated with a pathological EOG record and normal ERG
response. The observation is a contribution to discussions in the literature
about the hereditary character of excavations of the optic nerve.
PMID- 10677901
TI - [Removal of silicone oils from the eyes after vitrectomy].
AB - The author describes his experience with elimination of silicone oil in 60
patients. The follow-up period was 4 to 16 months. In 30% of patients where the
retina adhered, removal of the oil was associated with improved visual acuity and
quality of vision. In 5%, on the other hand, removal of silicone oil was
associated with reoperation of a relapse of detachment of the retina as the
operation proved ineffective and the finding on the retina did not change. In 3%
patients who had only one functional eye there was a subjective deterioration of
vision. Before removal of silicone oil in adverse cases it is always necessary to
consider carefully the risks of a relapse of detachment and deterioration of
visual functions.
PMID- 10677902
TI - [Clinical results in 100 corneal transplantations].
AB - The authors refer clinical results of 100 consensual penetrating keratoplasties
performed at the Department of Ophthalmology, University Hospital, Hradec
Kralove, in the year 1997. There were 55 women (55%) and 45 men (45%). The mean
age of the patients was 58 years (range 18-84). The operation was performed for
keratoconus in 24 eyes (24%), pseudophakic or aphakic endothelial failure in 18
eyes (18%), primary endothelial failure in 14 eyes (14%), traumatic changes in 18
eyes (18%), post-inflammatory changes in 7 eyes (7%). The repeated
transplantation was performed in 19 cases (19%), for rejection of the previous
graft in 18 eyes (94.7%) and for refractive error in 1 eye (5.3%). The average
follow-up period was 10 months (range 6-17 months). For the control analysis 74
patients (74%) were available. The best corrected visual acuity was 6/6-6/18 in
21 eyes (28.4%) and 6/24-6/60 in 15 eyes (20.3%). Postoperative complications
comprised rejection of the graft in 17 patients (23.0%), endophthalmitis in 3
patients (4.1%) and secondary glaucoma in 4 patients (5.4%). The results of this
study indicate that despite the advantages achieved on this field, there is still
scope for improvement.
PMID- 10677903
TI - [A tear of the retinal pigment epithelium].
AB - Tears of the retinal pigment epithelium is less common complication of RPE
ablation. There is a discussion about the pathogenesis and the reasons of the
disease's origin. The presence of drusen reflects congenital changes of Bruch's
membrane with a tendency to rise the RPE tears after the former detachment.
Demonstrated patient before the foundation of a tear was followed up for drusen
in maculae bilaterally. There is reported the very characteristical
ophthalmoscopic and mainly fluorescein angiographic appearance accompanied with a
sudden loss of vision and the foundation of a fibrovascular scar.
PMID- 10677904
TI - [The Schmid-Fraccaro syndrome].
AB - The authors describe a female patient with bilateral colobomatous malformations
of the uvea in conjunction with anorectal atresia and other symptoms suggesting
Schmid-Fraccaro's syndrome called also cat eye syndrome. Using fluorescent
hybridization in situ, the authors identified the supernumerous bisatellite
marker chromosome derived from chromosome 22 which made it possible to confirm
the suspected diagnosis.
PMID- 10677905
TI - [Measurement of adhesion of the corneal lamella to the stroma in the early
postoperative period after microkeratotomy].
AB - The early postoperative adhesion of corneal lamella after LASIK was measured. The
interface was washed by hypo, iso and hypertonic saline solution and the
influence on the lamella adhesion was assessed. Drying the interface and the
excimer laser ablation of epithelial cells along the edge of the lamella were
assessed in terms of the influence on the adhesion. The term "phototerapeutic
epithelectomy (PTE)" was proposed for the excimer laser ablation of corneal
epithelial cells. Small insignificant influence of PTE was found. The clinical
application of PTE to increase the early adhesion of lamella is not recommended
because of the epithelial destruction along the lamella edge. The adhesion was
increased significantly by means of drying the interface which is recommended for
the clinical application. High variability od measurements between different eyes
was found.
PMID- 10677906
TI - [Use of citation indexes and impact factors].
AB - Article deals with evaluation method of scientific works by means of Citation
Indexes and Impact Factor which are produced by Institute for Scientific
Information of Philadelphia. It criticizes criteria of the usage of Impact factor
and way of research workers evaluation.
PMID- 10677907
TI - [Surgical treatment of idiopathic macular tears].
PMID- 10677908
TI - [Giant retinal tears].
PMID- 10677909
TI - [The HAAG-STREIT AG 900BQ--a good quality and affordable endoset for corneal
endothelial microscopy].
PMID- 10677910
TI - [Expression of p53, p21 and bcl-2 in prognosis of lung carcinomas].
AB - Expression of suppressor genes 53 and bcl-2 as well as of protein p21 (partly
induced by p53 gene) was analyzed in a group of 77 resection specimens and
bronchial excision of lung carcinomas (of all basic histological types--squamous
cell, neuroendocrine, adenocarcinoma, undifferentiated). Simultaneously the
relation of tumor immunophenotype and level of differentiation, cell death and 2
year-survival of patients was evaluated. Gene p53 showed non-only an expected
strong expression in squamous cell carcinomas but especially in adenocarcinomas,
which were newly characterized by exceptional hyper-expression of p53 in lowly
differentiated variants. Expression level of protein p21 and gene p53 was
parallel only in adenocarcinomas and undifferentiated carcinomas but discordant
in squamous cell and neuroendocrine carcinomas. Positivity of p21 slightly
prevailed in well-differentiated variants of the histological types but an
exceptional positivity was found even in all the undifferentiated carcinomas.
Gene bcl-2 revealed a paradox of strong expression in lowly differentiated
neuroendocrine and undifferentiated carcinomas. The level of bcl-2 expression in
squamous cell carcinomas was found higher than in references. Among tumors with
cell death there was an inverted relation of bcl-2 and p53 expression (high/low)
in neuroendocrine carcinomas but both of them were mostly negative in squamous
cell carcinomas. A more frequent 2-year-survival of squamous cell carcinomas was
verified for bcl-2 positive tumors and newly for p53 positive squamous cell
carcinomas. Evaluation of the expression of p53, p21 and bcl-2 in lung carcinomas
is so equivocal that its prognostic usage was found to be only complementary to
the direct immunohistochemical investigation of the growth activities.
PMID- 10677911
TI - [New diagnostic possibilities in Alport's syndrome].
AB - An overview of immunohistological and molecular genetic methods for diagnosis of
Alport syndrome (AS) is given with practical experience from groups of authors'
observations. Immunofluorescent investigation using antibodies against alfa
chains of collagen IV was performed on cryostat sections from 29 punction
nephrobiopsies and 9 skin excisions taken for support of differential diagnosis
of AS particularly against the thin membranes glomerulopathy. Alfa chains
deviations in other renal diseases were followed in another 14 cases. Molecular
genetical investigation of AS by an indirect DNA diagnostics was performed in 35
families with presumed AS and in 27 patients with probable mutation a mutation
screening of COL4AS gene by a direct method SSCP was made. The mutation was
proved in 10 cases. Because of genotypical and phenotypical variability of AS the
diagnostic gain only increases when all the accessible methods are combined.
PMID- 10677912
TI - Ovarian hemangioma.
AB - A rare case report of a clinically asymptomatic hemangioma of the left ovary is
described. This tumor was an additional and accidental finding in a biopsy
specimen removed because of a medium-sized mucinous cystadenoma in a 32-year-old
patient. Immunohistochemically the expressions of Factor VIII and smooth muscle
actin and negativity of estrogen and progesterone receptors were found.
PMID- 10677913
TI - [Well differentiated inflammatory subcutaneous liposarcoma (inflammatory atypical
lipomatous tumor)].
AB - Well differential inflammatory liposarcoma is a rare type of low grade
liposarcoma. Its microscopical features may simulate benign inflammatory
pseudotumor. A case of this lesion was described occurring in the subcutis of the
right supraclavicular region in 61-year-old woman. The tumor was round well
circumscribed and measured 3 cm in diameter. Histologically, it contained a 1.5
cm inflammatory nodule, which was surrounded by otherwise typical lipoma-like
liposarcoma. The inflammatory nodule was composed of lymphocytic aggregates and
spindle to stellate cells with mild atypism. No lipoblasts were seen in this area
which mimicked an inflammatory pseudotumor. Correct diagnosis was based on the
recognition of the lipoma-like liposarcoma area in this lesion. Our patient had
no recurrence six years after the tumor excision.
PMID- 10677914
TI - [Helicobacter heilmanii, a spiral bacterium, in gastric mucosa biopsies].
AB - Interest in possible microbiological causes of gastritis has increased
significantly since the discovery of Helicobacter pylori (Hp). Recently a spiral
bacterium named Helicobacter heilmannii (Hh) was described in association with
chronic gastritis in adult and pediatric patients. Comparisons between these two
organisms, as well as the literature on Hh, have also been reviewed. The
incidence of Hh gastritis is far lower than that of Hp gastritis. Concomitant
infections by Hh and Hp are very rare. It is very probable that Hh gastritis is
transmitted from domestic animals or pets to humans. The frequency of Hh
gastritis (11/6059 cases, 0.18%) in authors' material was similar to that
reported in Western Europe. The role of touch cytology has been becoming more and
more significant recently in the diagnosis of mucosal infections of the GIT.
PMID- 10677915
TI - [Use of science citation indexes and impact factors].
AB - Article deals with evaluation method of scientific works by means of Citation
Indexes and Impact Factor which are produced by Institute for Scientific
Information of Philadelphia. It criticizes criteria of the usage of Impact factor
and way of research workers evaluation.
PMID- 10677916
TI - [The effect of autolysis on the interpretation of results of immunohistochemical
detection of myoglobin and fibrinogen in the myocardium].
AB - Immunohistochemical detection of myoglobin and fibrinogen in the myocardium makes
it possible to diagnose very early stages of ischaemic/hypoxic changes of the
heart muscle. The authors demonstrate on the myocardium of a 58-years-old female
patients who died suddenly with the finding of acute infarction of the anterior
wall of the left ventricle with transmural rupture and cardiac tamponade the
effect of autolysis on this examination. Tissue excision taken from the close
vicinity of the rupture were subjected to autolysis at room temperature and
immersed in formol for fixation within an interval of 24 hours. The control
series of examinations was made in a similar way on the heart muscle of a 20
years-old woman who died from violent death, and ischaemic changes of the heart
muscle were not anticipated. While in the early stages of autolysis it was
possible to use combined immunohistochemical detection of myoglobin and
fibrinogen, after a longer postmortal interval extensive artificial losses of
myoglobin were observed, and the method of detection of fibrinogen deposits in
damaged cardiomyocytes seemed more suitable. Even after a postmortal interval of
168 hours it was possible to differentiate reliably damaged myocytes with
fibrinogen deposits from intact muscle fibres, where fibrinogen deposits were not
observed.
PMID- 10677917
TI - [Overview of the changes in alcohol content of beers produced in the Czech
Republic].
AB - Paper concerns the alcohol contents of beer now produced. The previous and
contemporary ways of beer signing as well as a complete list of beer sorts
produced in the Czech Republic is presented.
PMID- 10677918
TI - Impact of hepatitis B and C virus infection on the outcome of kidney
transplantation in Chinese patients.
AB - BACKGROUND: There has been improvement in kidney transplantation over the years;
however, the impact of hepatitis B and C virus (HBV, HCV) infection on the long
term outcome of kidney transplant is still controversial. METHODS: A total of 113
patients who received renal allografts from 1986 to 1998 were analyzed. Nine were
positive for both hepatitis B surface antigen (HBsAg) and antibody to HCV (anti
HCV) (Group 1), 20 were HBsAg-positive and anti-HCV-negative (Group 2), 30 were
HBsAg-negative and anti-HCV-positive (Group 3) and 54 were negative for both
markers (Group 4). The outcome and survival were compared among the four groups
of patients. RESULTS: The mean follow-up period was 5.1 +/- 3.2 years (range, 0.5
13 years) for all patients. Group 2 patients had significantly higher liver
related complications (35% vs 0%, p < 0.0001) and liver-related deaths (20% vs
0%, p = 0.004) than did Group 4 patients. Among all, four HBsAg-positive patients
had fulminant hepatitis and died within two years of transplantation. Three
(Group 2) of the patients who died were seropositive for hepatitis B e antigen
and/or HBV DNA and none had a history of or positive serologic marker to indicate
hepatitis of other etiologies. The remaining patient (Group 1) had evidence of
superinfection of HCV. Liver cirrhosis occurred in one, two and one patient in
Groups 1, 2 and 3, respectively, and hepatocellular carcinoma occurred in two and
one patient in Groups 2 and 3, respectively. Despite high liver-related mortality
in HBV-infected patients, paradoxically, no significant differences among the
four groups in the long-term graft and patient survivals were demonstrated. The
presence of HBsAg or anti-HCV was not associated with a poor prognosis of
survival as determined by Cox regression analysis. CONCLUSIONS: HBV or HCV
infection is not a contraindication to kidney transplantation in Chinese
patients. However, it should be noted that serious liver-related complications
may occur and limit survival in HBV- and/or HCV-infected patients after kidney
transplantation.
PMID- 10677919
TI - Significantly higher levels of oxidized LDL autoantibody in coronary artery
disease patients.
AB - BACKGROUND: Increasing evidence shows that oxidized low-density lipoprotein (ox
LDL) might play an important role in the pathogenesis of atherosclerosis. Ox-LDL
is immunogenic and induces an autoantibody, which we used as a tool for measuring
the content of ox-LDL in vivo. METHODS: Patients who were admitted for diagnostic
cardiac catheterization for typical or atypical angina pectoris were enrolled in
this study. After fasting for 12 hours, a venous blood sample was drawn from the
antecubital vein for testing triglyceride, total cholesterol, LDL cholesterol,
high-density lipoprotein (HDL) cholesterol, and ox-LDL autoantibody. The ox-LDL
autoantibody was quantified using an enzyme linked immunosorbent assay. All
patients underwent coronary angiography. Those who had more than 50% angiographic
coronary luminal stenosis, were grouped into the coronary artery disease (CAD)
group. RESULTS: Sixty-four patients were enrolled in the study (male/female =
46/18; mean +/- standard deviation, age, 64 +/- 9 years). The CAD group had a
significantly higher level of ox-LDL autoantibody than the non-CAD group (494.0
+/- 355.0 mU/ml vs 258.1 +/- 196.8 mU/ml, p = 0.004). However, the other lipid
profiles including triglyceride, total cholesterol, LDL-cholesterol and HDL
cholesterol were not statistically different between the two groups. Forty-six
patients in this study had an arterial blood sample taken from the femoral artery
for testing ox-LDL autoantibody. There was no significant difference between the
arterial and venous samples of ox-LDL autoantibody (385.2 +/- 333.3 mU/ml vs
399.3 +/- 339.5 mU/ml, n = 46, p = 0.530). CONCLUSIONS: Ox-LDL autoantibody was
significantly higher in the CAD group. Ox-LDL may prove to play a key role in the
pathogenesis of atherosclerosis. Further study of Ox-LDL and its role in the
process of atherosclerosis is warranted.
PMID- 10677920
TI - Catheter-induced coronary spasm--a view of mechanical factors and experience with
selective left coronary arteriography.
AB - BACKGROUND: Coronary spasm during cardiac catheterization is not unusual. The
mechanism of spasm remains uncertain, but is considered to be multifactorial.
Many researchers believe that coronary spasm that develops during catheterization
is partly spontaneous and partly catheter-induced. Because catheter-induced spasm
results from mechanical irritation, we tried to find the iatrogenic factors that
predispose patients to coronary spasm during coronary angiography. METHODS:
Retrospectively, we reviewed the records of 7,295 patients who underwent coronary
angiography at our hospital from June, 1983 to November, 1997; coronary spasm was
documented in 30 patients, who became the study group. We randomly selected 41
patients who had normal coronary arteries as the normal control group. After
reviewing cine films of coronary angiography, we compared these two groups for
several parameters. These parameters included the length and diameter of the left
main coronary artery (LMC), the angle between the LMC and the aorta, the angle
between the catheter tip and the LMC, whether the catheter tip came into contact
with the vascular wall and whether there was vessel wall bulging, catheter size
and catheter/LMC ratio. This angiographic data and the demographic features,
including age, sex, history of hypertension, diabetes mellitus, smoking, previous
myocardial infarction, family history of coronary artery disease, cholesterol and
triglyceride levels and chest pain character (exertional or rest pain) were
compared between the study patient group and the control group. RESULTS: The
results disclosed that larger catheter size (7.1 +/- 0.6 mm vs 6.4 +/- 0.7 mm, p
< 0.001), smaller LMC diameter (4.2 +/- 0.9 mm vs 4.9 +/- 1.0 mm, p = 0.004),
larger catheter/LMC ratio (0.07 +/- 0.05 vs 0.05 +/- 0.03, p = 0.022), catheter
contact with the vessel wall (27/30 vs 20/41, p < 0.001) and vessel bulging
(18/30 vs 5/41, p < 0.001) were related to catheter-induced coronary spasm. We
found that the catheter tip coming into contact with the vessel wall, vessel wall
bulging and catheter/LMC ratio (odds ratio 8.92 x 10(14)) were statistically
significant factors predisposing patients to catheter-induced coronary spasm.
CONCLUSIONS: Multiple factors contribute to coronary spasm. Of those, mechanical
or iatrogenic factors might predispose patients to spasm during coronary
catheterization. These facts deserve our attention, because iatrogenically
induced spasms may be avoided by meticulously selecting catheters and
manipulating them gently.
PMID- 10677921
TI - Influence of morning or evening administration on absorption of theophylline.
AB - BACKGROUND: Bronchoconstriction during the night causing nocturnal and early
morning wheezing is recognized as a major problem for asthmatics. Oral sustained
release theophyllines (SRTs) were developed to reduce the symptoms. A circadian
variation in theophylline kinetics has been demonstrated with many SRTs. The
purpose of this study was to evaluate the differences in serum theophylline
concentration (STC) caused by morning or evening dosing of Euphyllin Retard, a
brand of SRT, for a period of 36 hours following oral administration. METHODS: A
total of nine non-smoking healthy male volunteers were involved in the study,
with a two-period crossover comparison. They were randomly divided into two
groups. The first group took a single oral dose of 350 mg Euphyllin Retard at
8:00 A.M. and the second group took it at 8:00 P.M. Blood samples were collected
during the 36 hours following administration. Two weeks later, the first group
took the drug at night and the second group took it in the morning. The
difference in the absorption of theophylline with daytime administration versus
night-time administration was assessed using pharmacokinetic parameters derived
from the plasma drug concentration vs time curve. RESULTS: The means of
unextrapolated area under the concentration vs time curve (AUC) from time 0 to 24
hours (AUCUN) and of the extrapolated AUC from time 0 to infinity (AUCEX) in the
night phase were higher than those in the day phase (62.403 micrograms/ml/hr vs
53.081 micrograms/ml/hr, p = 0.9186; 107.21 micrograms/ml/hr vs 98.879
micrograms/ml/hr, p = 0.8807, respectively). The mean of maximum concentration
(Cmax) was higher in the night phase than that in the day phase (4.166
micrograms/dl vs 3.451 micrograms/dl, p = 0.9234). Daytime administration showed
a delayed time to maximum concentration (Tmax) when compared to that of night
time administration (6.5 hr vs 5.75 hr, p = 0.6244). The terminal elimination
rate constant (Kel) was lower in the day phase than in the night phase (0.053
l/hr vs 0.06 l/hr, p = 0.7601). The day phase and night phase data are combined
data from the two night and two day groups. The statistical analysis of the
results show that the time of administration does not influence the STC.
CONCLUSIONS: No diurnal variation in theophylline kinetics was found with
Euphyllin Retard. This study was performed in a limited number of normal healthy
subjects, and the same result is yet to be proved in asthmatic patients and a
larger population of normal subjects.
PMID- 10677922
TI - In vitro activity of quinupristin/dalfopristin and other antibiotics against
ampicillin-resistant enterococcus faecium.
AB - BACKGROUND: Enterococcus faecium constitutes approximately 10% of clinical
isolates of enterococci and is noted for its antimicrobial resistance. In
particular, E faecium is commonly resistant to ampicillin. The optimal treatment
for severe infections caused by these multi-resistant organisms has yet to be
determined. METHODS: Enterococci tested were isolated from blood, pleural fluid
and cerebrospinal fluid. Ampicillin-resistant Enterococcus faecium (AREF) was
identified using the API Rapid Strep Kit system. A total of 58 isolates of AREF
were enrolled in this study. Ten different antibiotics were tested, including
Synercid (quinupristin/dalfopristin), teicoplanin, vancomycin, ampicillin,
trimethoprim/sulfamethoxazole (TMP/SMX), ciprofloxacin, gentamicin,
chloramphenicol, rifampicin and tetracycline. The agar dilution method described
by the National Committee for Clinical Laboratory Standards was used to determine
the minimum inhibitory concentrations (MICs) of the antibiotics tested. RESULTS:
Teicoplanin showed the best in vitro activity. Its MIC ranged from 0.25 to 2
micrograms/ml with an MIC90 of 1 microgram/ml. The MIC of vancomycin was 0.5-128
micrograms/ml with an MIC90 of 2 micrograms/ml. Three strains were vancomycin
resistant, and they were the VanB phenotype. The MIC of quinupristin/dalfopristin
was 0.5 to 8 micrograms/ml with an MIC90 of 2 micrograms/ml. Chloramphenicol and
tetracycline showed moderate susceptibility. AREF showed high resistance to other
antibiotics tested, including ciprofloxacin, gentamicin, TMP/SMX and rifampicin.
High-level gentamicin resistance (MIC > 1,000 micrograms/ml) was found in 78% of
AREF tested. CONCLUSIONS: Teicoplanin showed the best in vitro activity against
AREF. Clinical studies are necessary to confirm the efficacy of
quinupristin/dalfopristin in vivo.
PMID- 10677924
TI - Lymph node revealing solution and traditional 10% buffered formaldehyde for
detecting lymph nodes in colorectal carcinoma.
AB - BACKGROUND: Cancer stage has been the most important factor in evaluating the
prognosis and treatment of colorectal carcinoma, and the presence of lymph node
metastasis in the resected specimen plays a key role in serial staging. We
evaluated a newly proposed "lymph node revealing solution" (LNRS) that proponents
claim is inexpensive, easy, rapid, and innocuous, and that could help to
establish the stage of disease more accurately than buffered formaldehyde
(formalin). Our study compared traditional 10% formalin and LNRS as second search
solutions to determine whether LNRS is a more useful and practical solution than
formalin. METHODS: Thirty randomly selected colorectal carcinomas from low
anterior resection (LAR) were studied. The specimens were handled routinely on
the first day. Then, the entire fat of odd-numbered cases was immersed in three
times its volume of LNRS, and the entire fat of even-numbered cases was immersed
in 10 times its volume of formalin overnight. The chi-squared test was used to
evaluate the results. RESULTS: Of 145 cassettes in the second search by LNRS,
seven had no lymph nodes. Of 107 cassettes in the second search by formalin, 18
had no lymph nodes. Totally, 792 lymph nodes were found with an average number of
26.4 per case and 1.53/cm (per centimeter of specimen) in all 30 cases. By the
LNRS method, 138 lymph nodes were found in the 15 odd-numbered cases, and by the
formalin method, 89 lymph nodes were found in the 15 even-numbered cases. We were
able to adjust the stage upward in two cases by LNRS-fixation method. There were
no changes in staging in the formalin-fixation method cases. CONCLUSIONS: LNRS
showed no statistically significant difference from formalin in the numbers of
total lymph nodes, positive lymph nodes, or minute (less than 1 mm) lymph nodes
found. Nonetheless, we do believe that LNRS is a potential replacement solution
for formalin due to its fast fixation, ease of searching, high identification
rate and time-saving procedure.
PMID- 10677923
TI - Prediction of biochemical relapse for stage pT3 prostate cancer following radical
prostatectomy.
AB - BACKGROUND: Approximately 30% to 50% of clinically localized prostate cancers are
found to be locally advanced after radical prostatectomy. Without adjuvant
therapy, more than 30% of stage pT3 patients will have biochemical failure in a
median follow-up of three years. Whether adjuvant therapy should be given remains
controversial. Identification of prognostic indicators may be helpful to select
patients at risk of biochemical failure for postoperative adjuvant therapy.
METHODS: The medical records of 22 pT3 prostate cancer patients were analyzed
retrospectively. Postoperative management included surveillance (7 patients),
adjuvant hormone therapy (7) and radiotherapy (8). Patients were monitored every
three months using serum prostate-specific antigen (PSA). Biochemical failure was
defined as an elevation in PSA of more than 0.2 ng/ml. The clinical outcome was
correlated with tumor grading, pathologic staging, preoperative PSA level, and
p53 and bcl-2 status. RESULTS: Five patients (23%) experienced biochemical
relapse within a median follow-up time of 52 months (range, 10-71 months). A
Gleason score of 8 or more (p = 0.001) and seminal vesicle involvement (p =
0.014) were significant prognostic indicators in the univariate analysis.
Patients with low preoperative PSA levels (< 20 ng/ml) had a significantly higher
failure rate (p = 0.031). However, most of these patients (56%) had tumors with
Gleason scores of 8 or more. Neither p53 gene mutation nor bcl-2 overexpression
predicted PSA failure. Postoperative adjuvant therapy did not appear to reduce
the risk of disease recurrence. In multivariate analysis, the Gleason score was
the only significant factor predicting biochemical failure (p = 0.017).
CONCLUSIONS: Patients with poorly differentiated tumors and/or seminal vesicle
invasiveness are at higher risk of biochemical failure after radical
prostatectomy. Our limited experience did not support the routine application of
adjuvant therapy for this subgroup of patients. A larger sample size with a
longer follow-up period is necessary to reach a definitive conclusion.
PMID- 10677925
TI - Midbrain hemorrhage presenting with trochlear nerve palsy.
AB - A 40-year-old normotensive man suddenly developed diplopia, tinnitus and a
burning sensation on the left side of his body while driving a motorcycle. He did
not complain of headache, nausea or vomiting. Neurologic examination revealed
left trochlear nerve palsy and impaired pinprick, temperature and joint position
sensation of the left limbs. There was no ptosis or motor deficit. He had a mild
bleeding diathesis due to alcoholic liver cirrhosis. Computerized tomography and
magnetic resonance image of the brain disclosed hemorrhages in the right midbrain
tectum and the left temporal lobe. After nine months of observation, there was
nearly complete recovery of symptoms, except for mild residual diplopia. From a
literature review, only nine case of midbrain tectal hemorrhage involving the
inferior colliculus have been reported. These patients had a unique clinical
presentation. Diplopia due to trochlear nerve palsy, either unilateral or
bilateral, was present in all of the cases. Tinnitus and sensory disturbance
contralateral to the lesion side were very common. Only three patients had risk
factors for hemorrhage, including bleeding diathesis, hypertension and vascular
anomalies. In the majority of patients, no underlying causes were detected. The
outcome was favorable with conservative treatment.
PMID- 10677926
TI - Symptomatic esophageal stricture after endoscopic variceal ligation--success of
endoscopic balloon dilation.
AB - Endoscopic variceal ligation is a preferred endoscopic method to treat esophageal
variceal bleeding. Esophageal stricture complicated by endoscopic ligation is
very unusual. We report a case of symptomatic esophageal stricture after variceal
ligation. Endoscopic balloon dilatation was used to treat the stricture
successfully. The possible mechanism of stricture formation is discussed.
PMID- 10677927
TI - Immediate repair of intestinal injury during laparoscopically assisted vaginal
hysterectomy.
AB - With the increasing popularity of laparoscopic surgery in gynecologic diseases,
complications with this procedure are noted more frequently. The majority of
complications occur during operation, and most of the cases are immediately
identified. The recovery and outcome are relatively good due to urgent repair and
management. Herein, we report a complication--a trocar, inducing small intestinal
damage, which was detected during laparoscopically assisted vaginal hysterectomy.
The damage was repaired promptly extraperitoneally with an uneventful recovery.
Through a review of the literature and our experience, possible preventive
methods of this complication are discussed. In addition, by this case review, we
hoped that such a complication could be avoided in the future.
PMID- 10677928
TI - Coexistence of epilepsy, myasthenia gravis and psoriasis vulgaris.
AB - We report the case of a 36-year-old Chinese man with a history of complex partial
seizure of temporal lobe origin since the age of 12 years, superimposed by
myasthenia gravis since the age of 27 years and psoriasis vulgaris since the age
of 29 years. With an eight-year follow-up, the above three diseases remained
without complete remission. Anticonvulsant therapy (phenytoin and trimethadione)
caused drug-induced myasthenia gravis, which should gradually disappear after
discontinuing the drugs. However, the myasthenic symptoms and serum acetylcholine
receptor antibody persisted following the discontinuation of phenytoin in our
patient. Myasthenia gravis and psoriasis are both autoimmune diseases and
correlate with specific human histocompatibility antigens. This suggests a close
connection between these two diseases. The coexistence of epilepsy, myasthenia
gravis and psoriasis vulgaris has not been previously reported, and to the best
of our knowledge, our patient is the first reported case. The relationship among
these three diseases requires further investigation.
PMID- 10677929
TI - Endoscopic sinus surgery for ethmoid sinus meningioma.
AB - Meningiomas in the ethmoid sinuses are a challenge to manage. A 50-year-old man
suffered from a left olfactory groove meningioma. He underwent a bilateral
craniotomy to remove the tumor mass in August, 1997. During the follow-up period,
a tumor was found in the right posterior ethmoid sinus. Endoscopic sinus surgery
was performed to remove the tumor mass in August, 1998. Pathologic examination of
the mass revealed a meningioma. No intraoperative or postoperative complications
occurred, except for an episode of seizure.
PMID- 10677930
TI - Successful birth after intracytoplasmic sperm injection for severe male factor
infertility in a woman with poor response to controlled ovarian hyperstimulation.
AB - Poor responders to controlled ovarian hyperstimulation (COH) present a clinical
challenge for in vitro fertilization (IVF) and embryo transfer. The failure of
IVF for the treatment of severe male-factor infertility can now be overcome by
intracytoplasmic sperm injection (ICSI). The infertile couple documented in this
case report came to our hospital because of bilateral tubal occlusion and severe
oligoasthenospermia. After three poor-response cycles to COH, one mature oocyte
was retrieved and was fertilized using ICSI. Normal fertilization ensued and one
good-quality, eight-celled embryo was transferred into the woman's uterus. A
single gestation was confirmed by ultrasound seven weeks after transfer.
Amniocentesis was performed at 16 weeks and demonstrated a normal male fetus with
a karyotype of 46,XY. The patient had a spontaneous, normal, vaginal delivery of
a 2,650 g healthy male infant.
PMID- 10677931
TI - Congenital muscular dystrophy.
AB - Congenital muscular dystrophy (CMD) is a rare heterogeneous disease found in the
oriental population, especially the occidental type of CMD. We report a case of a
one-year-old infant who presented with early onset hypotonia, muscular weakness,
delayed motor development and normal intelligence. A muscle biopsy revealed
dystrophic muscle fibers. A high creatine kinase (CK) level, mostly of the MM
type, was also noted. Further study of brain images showed hyperintense lesions
in the white matter area. The patient showed the clinical and laboratory findings
characteristic of CMD, more likely to be of the occidental type. Further genetic
or histopathologic studies, especially merosin investigation, are suggested for
improved classification and prognosis prediction.
PMID- 10677932
TI - Chronic myeloid leukemia initially presenting with spontaneous mediastinal
hematoma and hemothorax.
AB - Spontaneous mediastinal hematoma is rarely seen in hematologic malignancy. We
report a case of chronic myeloid leukemia initially presenting with spontaneous
hematoma and hemothorax. In addition to a detailed history, computerized
tomography of the chest is important in analyzing whether an anterior mediastinal
mass lesion is present. Magnetic resonance imaging is helpful in confirming the
nature of a mediastinal hematoma. Trauma, vascular disease and coagulopathy
should first be ruled out when making a diagnosis of spontaneous bleeding in the
thorax. In our patient, the mediastinal hematoma regressed spontaneously after
three months. Leukemia should be considered in the differential diagnosis of
spontaneous mediastinal hematoma. In leukemia patients with spontaneous
mediastinal hematoma, supportive observation and close follow-up may be better
than surgery, unless massive hemorrhage or active bleeding in the thorax is
suspected.
PMID- 10677933
TI - [nm23 expression and its correlation with lung metastasis in human salivary
adenoid cystic carcinoma].
AB - The nm23 gene products, nucleoside diphosphate kinase (NDPK), expression in
salivary adenoid cystic carcinoma (ACC) was evaluted by using LSAB
immunohistochemical method. Of 25 cases tested, 16 (64.0%) showed positive
staining, in which, higher incidence of positive staining was found in ACC
without lung metastasis (88.2%, 15/17) than in that with lung metastasis (12.5%,
1/8; P < 0.01). Expression of NDPK/nm23 was correlated with the P-TNM pattern (P
< 0.05), otherwise it was not correlated with pathologic types (P > 0.05). The
result suggest that the nm23/NDPK may play a role in suppressing the metastatic
potential in ACC.
PMID- 10677934
TI - [Serotype distribution of Actinobacillus actinomycetemcomitans].
AB - A total of 131 Actinobacillus actinomycetemcomitans clinical strains from 28
periodontally healthy or diseased subjects were serologically categorized by
indirect enzyme-linked immnosorbent assay. Sepecies-specific and serotype b, c
specific monoclonal antibodies against Actinobacillus actinomycetemcomitans were
used. Preliminary data revealed that each subject harbored only one serotype of
Actinobacillus actinomycetemcomitans. The distribution of serotype a, b and c
were respectively 11%, 21% and 68%, both of periodontally healthy subjects
harbered serotype b, 7 of 9 juvenile periodontitis subjects harbered serotype c,
12 of the other subjects which included 3 adult periodontitis and 14 gingivitis
harbered serotype c.
PMID- 10677935
TI - [Surgical correction of dentofacial deformities following temporomandibular joint
ankylosis].
AB - The paper presents 22 patients (9 male, 13 female; 13 unilateral, 9 bilateral)
with temporomandibular ankylosis and dentofacial deformities treated by
arthroplasty and orthognathic operations. The results were satisfactory. The key
point is to ensure the function of mouth opening and correction of dentofacial
deformities caused by ankylosis. The indications for one-stage or two-stage
surgical correction are discussed.
PMID- 10677936
TI - [Mast cells in the labial cancer: histochemical and electron microscopical
study].
AB - The labial cancer tissue of 24 cases and normal labial tissue of 7 cases were
studied histochemically and electron microscopically. The result showed that the
number of mast cells around the periphery of labial cancer tissue increased
significantly. The histochemical properties of these mast cells differed from
those in the normal labial tissue. The former did not contain heparin which was
present normally. Under electron microscope, according to the characteristic
ultrastructure, the mast cells around the labial cancer were TC mast cells. Some
of them showed the appearance of degranulation, and contacted intimately with
cancer cells, lymphocytes and macrophages, etc. These findings suggest that
together with lymphocytes, macrophages, these mast cells contribute to the
defence reaction to the cancer tissue.
PMID- 10677937
TI - [Experimental study on bone formation in a denser coral used for repairing
cortical defects in dogs].
AB - The present study was designed to investigate a coral skeleton, Favites, which
was originated from the reef builders in Hainan island, as a bone substitute. The
coral Favites, like porites, is composed of anagonite (CaCO3), but contains less
volume of porosity, higher strength and denser construction than Porites. After
implanted into cortical bone defects in mandibles and femurs of dogs, skeleton
fragment of coral Favites demonstrated good biocompatibility and
biodegradability. A resorption of the implant and a simultaneous apposition of
new bone was observed. Coral Favites was totally replaced by newly formed bone
after a period of time from 6-8 months. Compared to Porites, Favites has a lower
rate of resorption and therefore the defects of host bone are repaired completely
without any lost of bone volume. The results showed that coral Favites may be
used as a bone substitute for the segmental defects of mandibles.
PMID- 10677938
TI - [Finite element analysis of force produced by "T" loop retraction archwire].
AB - This study introduced three presumed springs to imitate the three dimensional
bolstering function of the bracket-tooth-periodontal tissue on the archwire with
three dimensional finite element method (FEM), and, systematically analysed the
force system produced by the "T" loop retraction archwire on the incisors. The
following conclusions were drawn; (1) The activation of the "T" loop retraction
archwire will produce extrusion and root lingual torque force as well as
horizontal force on the incisors; (2) Adequate torqul on the incisor segment and
gable bend mesial to the T-loop are necessary to control the position of the
anterior teeth while they are being retracted; (3) retraction archwire should not
be activated too much; (4) Lighter wire will produce milder and more durable
forces.
PMID- 10677939
TI - [Clinical studies on pulpitis and periapical periodontitis caused by traumatic
occlusion].
AB - 89 cases including 100 teeth with pulpitis and apical periodontitis caused by
traumatic occlusion were clinically observed. All teeth are caries-free, no any
dental disease, and no pocket formation. But there is a distinct evidence of
marked occlusal trauma, such as premature contact and occlusal interference. The
single-root teeth are usually involved. When subjected to vitality testing the
teeth associated with the periapical lesions sometimes yield positive response
(about 30%). The result of investigation endodontic treatment demonstrated that
the presence of predisposing factors of trauma from occlusion led to decrease of
endodontic success.
PMID- 10677940
TI - [Electron microscopy of elastic system fibers in the rat mandibular joint].
AB - We study the Elastic System Fibers (ESFs) in the rat mandibular joint using light
microscope and image analyzer system and Electron Microscope. The results showed
that the ESFs in the articular disc and capsule were more than in the articular
cartilage. In addition, microfibrils and elaunin were the principal ESFs in all
the articular components. The microfibrils in the articular surfaces ran at
nearly right angle to the collagen fibers. The ESFs beneath the articular
surfaces and the other articular components showed no specific directivity. ESFs
construct an extensive fibers network in the disc and the capsule.
PMID- 10677941
TI - [Using Nd-YAG laser to desensitize the hypersensitive dentine in preparing the
abutment teeth for removable partial dentures prosthesis].
AB - Patients often suffer from sensitivity and pain while preparing the seats of
occlusal rests of clasps on abutment teeth with hypersensitive dentine for
removable partial dentures prosthesis. Base Nd-YAG laser desensitization effect
by making a hard surface layer in the hypersensitive dentine of the abutment
teeth, We use this method to treat the teeth before and after occlusal seats of
clasps preparation, 20 patients, more than 30 occlusal seats of clasp rests are
completed smoothly without any suffering since 1991. All the patients wear their
dentures satisfactorily without afterward side effect. After half one year to
four years followed observation all the rests adapt to their seats well without
marking wear, We believe that the desensitizing effect of Nd-YAG Laser is
effective in preparing occlusal seats for removable partial denture prosthesis.
PMID- 10677942
TI - [Quantitative histological study of adult condylar proliferation zone].
AB - The thicknesses and cell numbers of 43 adult condylar proliferation zone were
observed by serial section and multiarea measurement in order to investigate the
relationships between them and age. The samples were divided into three groups by
age (19-45, 46-59, 60-74). By way of statistical analysis, the cell numbers and
thicknesses of different areas of the same age group, different age of the same
area, and the relationship between thicknesses and age was analysed. The results
show that the average proliferation zone thickness is different among different
age groups, it becomes thinner with the increase of age, and the cell number is
decreased. There is high significant difference among different age groups (P <
0.01). But there is no significant difference of the proliferation zone thickness
between the group of 45-59 years old and the older group (60-74)(P > 0.05). There
is diverse correlation between thicknesses and age increase.
PMID- 10677943
TI - [A bio-electrochemical theory in pathogenesis of dental caries].
AB - Since the Bio-electrochemical theory in pathogenesis of dental caries was
suggested by Huang (1990), many experimental proofs have obtained in studies of
dental bio-electrical potential and dielectric properties of the tooth. Recently,
the model of the electrochemical artificial dental caries that have directly
proved Huang's theory was developed successfully in laboratory. This paper make a
systematic exposition of the bio-electrochemical theory in pathogenesis of dental
caries.
PMID- 10677944
TI - [Mandibular ridge augmentation by sandwich osteotomy and BMP-HA implantation].
AB - In order to solve a series of problems ridge augmentation by subperiosteal
implantstion, HA combined with BMP was implanted in between the two pieces of
mandible produced by osteotomy. Nine adult mongrel dogs were used in this study
and six patients were treated with this mathod. The specimens were examined by
light microscope, scanning electron microscope in the experimental study. The
results show that there are a large amount of new bone formation both within and
around the combined material. The amount is increasing as the time lapsed and the
new bone is connected directly with the host bone of two side. Clinical
application showed that after augmentation of the atrophic alveolar ridge with
this mathod, the shape and volume of the alveolar ridge were good. The retention
and stability of the lower denture was improved significantly. The results showed
that this method of alveolar ridge augmentation has many advantages.
PMID- 10677945
TI - [The experimental study about the relations between Chinese herb-epimedium
leptorrhizum stearn (CH-ELS) and endogenous cAMP in alveolar bone of orthodontic
tooth in rats].
AB - The aim of this study was, to explore the mechanism of CH-ELS promoting bone
remodelling of orthodontic tooth in rats. 11 male sprague-Dawleg rats was divided
into 3 groups. Group I (normal control group) Group II (applied force, no
injection) Group III (applied force, injection). The experimental period was 3
days. The radioimmunoassay (RIA) method were used to investigate the effects of
CH-ELS on the content of endogenous cAMP in alveolar bone of orthodontic tooth in
rats. Results indicate that CH-ELS has no significant effects on endogenous cAMP
in alveolar bone of orthodontic tooth, perhaps, cAMP were not involved to
regulate the mechanism of CH-ELS promoting bone remodelling. To explore the
mechanism of bone remodelling of orthodontic tooth is more significant in
orthodontic clinic.
PMID- 10677946
TI - [Significance of glycosaminoglycans content in developing mechanism of cleft
palate].
AB - To explore significance of Glycosaminoglycans content in the development of
embryo and forming mechanism of cleft palate, Dexamethason acetate was injected
into the abdomen of NIH mouse on the 12th day of gestation to induce cleft palate
mouse embryo model. Then by taking cranio-maxillary coronary sections, stained
with Alcian blue/PAS and quantitatively analysing the area of the palatal process
covered by glycosaminoglycans using a TDS-90 photodigital system with computer.
Results indicate that on 13(12) day(hour) of gestation the colour of Alcian blue
starts to show in the palatal process. By then, the area covered by
glycosaminoglycans in the normal group is 4.69 mm whereas for the experimental
group is 2.40 mm, showing a significant statistical difference (P < 0.05). The
area of the palatal process covered by glycosaminoglycans gradually increases as
the embryo developes, but is distinctly smaller in experimental than in the
normal group (P > 0.05). This proves that there's a relationship between the
level of glycosaminoglycans in the palatal process and development of cleft
palates.
PMID- 10677947
TI - [Effects of IL-1 on experimental tooth movement in rabbits].
AB - The purpose of this study was to search the effects of IL-1 on the orthodontic
tooth movement and alveolar bone by animal experiment. The distance of tooth
movement was measured and histologic changes were observed. 12 rabbits were
divided into two groups. IL-1 was injected in the gingiva around the moving tooth
of the experimental group. The rate of tooth movement and the number of
osteoclasts of the two groups were compared. The results suggested that IL-1 can
promote the tooth movement and increase the number of osteoclasts and can also
promote bone remodelling.
PMID- 10677948
TI - [The alveolar bone density in rats with experimental diabetes].
AB - The alveolar bone turnover in rat with experimental diabetes was investigated.
The serum osteocalcin concentration in diabetic rat was shown to increase as
determined by radioimmunoassay; while alveolar and femur bone density decrease as
determined by Dual Energy X-ray Bone Densitometer; histological examination
showed that bone resorption was increased and bone formation decreased in the
alveolar bone in diabetic rat. It is suggested that the alveolar bone in rats
with diabetes mellitus have a tendency to develop osteoporosis.
PMID- 10677949
TI - [Effects of overdose fluoride on metabolism of extracellular matrix collagen and
proteoglycan in condylar cartilage].
AB - The study was conducted to evaluate the effects of chronic fluorosis on the
metabolism of extracellular matrix in the development of rabbit condylar
cartilage using the technique of pathology, biochemistry and radiographs. The
results demonstrated that collagen content of condylar cartilage and the bone
under condylar cartilage decreased (P < 0.01), and the proteoglycar contents
increased significantly during the process of fluorosis (P < 0.01). The
chondroprogenitor was obviously thin, and the cells of maturation zone increased
in number. All the results indicated that overdose of fluoride retarded the
growth of the condyle and ramus of the mandible.
PMID- 10677950
TI - [The behaviour and treatment of myoepithelial carcinoma of salivary glands].
AB - Nineteen cases of myoepithelial carcinoma (malignant myoepithelioma) in salivary
glands were studied clinicopathologically. The clinical features are as follows:
arise most frequently within the parotid glands, followed by the submandibular
glands; rapidly enlarging mass with extensive invasion of the surrounding tissues
in some cases; low rate of cervical lymph node metastasis but high rate of
distant metastasis; very frequent recurrence after surgical excision; and poor
prognosis. The carcinoma belongs to the high grade malignant tumor. It must be
treated radically. The elective neck dissection is generally unnecessary. It is
resistant to radiotherapy. It is possible to get rather good result in limited
recurrent tumors by prompt surgery.
PMID- 10677951
TI - [Detection of types I, III and IV collagen in human cementum, periodontal
ligament and alveolar bone].
AB - The aim of the present study was to investigate distribution and composition of
collagen Types I, III and IV in human cementum, periodontal ligament and alveolar
bone with immunohistochemical localization and image analysis technique. The
results showed that collagen Type I was 78.06% in periodontal ligament, 73.09% in
cementum and 30.50% in alveolar bone; Type III was 11.73% in periodontal ligament
and was also observed in apical cementum and bone tissue of alveolar socket; Type
IV was restricted to the basement membrane of the blood vessles; Sharpey's fibers
was stained by Type I and its periphery was demonstrated stronger staining by
Type I and Type III as a sheath. These results provided necessary informations on
healthy periodontal tissues that will be required for future studies on the
effects of pathological and regenerative processes.
PMID- 10677952
TI - [Titanium plate reconstruction and fixation system for maxillofacial surgery: a
synthetic clinical and experimental investigation].
AB - Titanium plate-screw systems for maxillofacial reconstruction and internal
fixation were studied including examination of chemical components, measurement
of mechanical natures, biomechanical and biological evaluation, in combination
with retrospective analysis of 319 cases fixed by means of plate-screw
appliances. The results demonstrated that all experimental data have satisfied
basically the design and clinical requirements, with the exception of a weaker
curve-resistance and fixative stability of miniplate as well as lower surface
wear-resistance of pure titanium. So, further improvement is necessary.
Additionally, the function classification and indication of plate-screw systems
are discussed. The duration and condition of intermaxillary fixation is
suggested. The complications and their causes are analysed through comparison
among different fixation systems.
PMID- 10677953
TI - [Image analysis of cell nuclear morphology and DNA content in osteosarcoma of the
jaws].
AB - The measurement of nuclear morphology and quantitative analysis of nuclear DNA
content were made by Interactive Image Analysis System in 47 osteosarcomas of the
jaws. The results showed that with a decreased degree of differentiation, the
cell nuclei of osteoblastic and chondroblastic osteosarcomas came to be large and
irregular, those of fibroblastic osteosarcomas, however, to be small and round.
It was revealed that high-grade osteosarcomas had increased amounts of DNA and
that the mean of DNA content, proportion of hyperploid cells and tumor ploidy
were found to be of important prognostic value.
PMID- 10677954
TI - [Studies on aging enzyme activities of the human dental pulp blood vessels].
AB - Histochemical distribution and age changes of alkaline phosphatase (AKPase E. C.
3. 1. 3. 1) and adenosine triphosphatase (ATPase E. C. 3. 6. 1. 3) in normal
human dental pulp blood were investigated qualitatively and quantitatively. 42
dental pulp samples from patients aged 10 to 70 years old were divided into three
groups. Results showed that accompanying aging, activities of AKPase and ATPase
of dental pulp blood vessels decreased. AKPase staining quantities for group one
(10-30 years), group two (31-50 years) and group three (51-70 years) were 40.62
+/- 13.79, 36.75 +/- 9.78 and 19.20 +/- 5.35 and ATPase staining quantities were
33.00 +/- 10.09, 27.53 +/- 16.60 and 23.27 +/- 5.04 respectively. The endothelial
cells of capillaries in dental pulp changed greatly. With aging, metabolic
ability of dental pulp decreased gradually. In addition, it was observed that the
capillaries in sub-odontoblasts decreased and odontoblast layer became thin with
aging. The close association of the capillaries of the pulp to the odontoblasts
had been demonstrated.
PMID- 10677955
TI - [Gama hydroxybutyrate sodium (gama-OH)-diazepam combined anaesthesia for cleft
palate repair in children below 3 years old].
AB - To investigate the effect of Gama-OH-Diazepam combined anaesthesia for cleft
palate repair in children below 3 years old. METHODS: Heart rates were measured
in 120 children at induction, at 5 minutes after endotrocheal intubation, at
finishing of operation, and at 5 minutes after extubation. In addition, changes
of SpO2 was randomly detected in 10 children. RESULTS: Heart rate decreased after
intubation, increased when operation was completed and decreased again after
extubation. SpO2 of all stages were in the normal range. CONCLUSIONS: This method
of anaesthesia is suitable for cleft palate repair in children below 3 years old,
with the advantages of little effect on the children's circulatory and
respiratory systems, and being easy to perform and control.
PMID- 10677956
TI - [Palatography including lingual and occlusal surface of teeth, palatogram pattern
of Chinese sounds].
AB - In order to develop a method that can determine not only the contact pattern of
the tongue with the palate but also with the teeth during speech. Static
palatograph recording system was used in this study. Palatograms of six normal
dentulous adults were made by the recording system during pronounce the following
Chinese phonetic alphabets: /S/, /X/, /D/, /J/, /N/, /K/, /R/, /L/. The contact
pattern that is the contact area of tongue to palate and tongue to teeth in the
palatograms were identified and analysed. The result indicated that the
palatograms of the six normal adults are different which can be divided into four
types: Type1/S, X/; Type2/D, N, J/; Type 3/K/; Type 4/R, L/.
PMID- 10677957
TI - [The inhibitory effect of hydroprednisolone on tumor necrosis factor in rabbits'
temporomandibular joint disturbance syndrome].
AB - In order to study the mechanism of hydroprednisolone for temporomandibular joint
disturbance syndrome (TMJDS), 12 white rabbits were injected TNF into the
rabbits' right TMJDS for 2 to 3 times, 90,000 u each time, then another drug, 2
mg hydroprednisolone, was injected into these TMJDS again. The rabbits were
killed after 8 to 18 days and the TMJDS were examined by microscope. We found the
articular tissues only destroyed slightly and sometimes the cartilages were
nearly normal. So, the study suggested that hydroprednisolone can reduce the
destruction of TNF on rabbit's TMJ obviously. This may be the cause why
hydroprednisolone is useful to TMJDS.
PMID- 10677958
TI - [The use of panoramic radiograph to observe abnormal movement of condyle].
AB - The abnormal movement of mandible is one of the three chief symptoms of TMJDS, it
is described usually by the degree and type of mouth opening. We use close and
open mouth position panoramic radiographs of 144 cases with TMJDS to observe the
relationship between the head of condyle and the articular eminence. It can show
the different degrees of movement of condyle and the degree of movement of both
sides to see they are in balance or not. We classified the movement of the
condyle in to six types, and measure the degree of mouth opening on the same
film. The rela-tionship between the result of them and the climnical symptoms are
then analysed. We concluded that the supermovement of the condyle, which cause
the acute and chronic trauma to the structures of TMJ and related muscles and
ligaments, is one of the chief etiologic factors of TMJDS. The method and
advantages of using panoramic radiography to observe movement of condyle are
discussed.
PMID- 10677959
TI - [A study of parotid salivary proteins from caries-free and caries-active people
by high performance liquid chromatography].
AB - In this study, we isolated and analysed parotid salivary proteins of different
individuals with different caries-susceptibility. Protein fractions isolated were
identified by biochemical methods. The results showed that six proteins were
isolated from parotid saliva by HIC (hydrophobic interaction chromatography).
Four proteins were found in all hydrophobic interaction chromatography. Three of
them were identified as different polymorphic forms of proline-rich proteins
(PRPS) and the other as alpha-amylase. Comparing chromatography of fifteen
healthy caries-free adults with ten caries-active adults, we found that there was
no difference in salivary protein composition. Three different phenotypes of PRPS
had different relations with caries-susceptibility and relative ratios of the
three PRPS were different between two groups. It suggested that abnormal
proportions of salivary proteins may be another important determinant in caries
susceptibility.
PMID- 10677960
TI - [A comparative study of autologous facial nerve graft in situ with the vein
tubulation: the observation of neurons changes].
AB - For further study of the effects of the repairment of facial nerve with vein
tubulation, we used horseradish peroxidase (HRP) retrograde mark method to
observe the changes of the labeled cells in facial neucleus after the tubulation
of rat facial nerve. And, we compared the changes with nerve graft in situ and
the normal group. The results showed: 1. The vein tubulatiton can repair the
short defect of facial nerve as well as the nerve graft does. 2. Irregular
outgrowth of axon sprouts could be found in both methods. 3. There was few chance
for homolateral target organ to be reinnervated by contralateral motoneurons in
both methods. 4. Using the vein tubulation method, a more natural relationship
between the peripheral target organ and central nucleus may be easily achieved.
PMID- 10677961
TI - [Ultrastructure of adherence of Streptococcus mutans MT8148 and its
glucosyltransferase deficient mutants].
AB - The ultrastructure of adherence of Streptococcus mutans MT8148 and its
glucosyltransferase deficient mutants were compared by Scanning Electronic
Microscope. Four patterns of adherence of tested strains in the presence of
sucrose were observed. These results suggest that the cell-associated GTase is
responsible for firm aggregation of cells. However, cell free GTase is also
important in aggregation between cells.
PMID- 10677962
TI - [Three-dimensional finite element stress analysis of magnetical retaining and bar
retaining in overdenture implants].
AB - The purpose of this study was to determine which type of denture retaining
implants can produce better biomechanical effect on the bone tissue. Two
mechanical models of magnetically retained complete overdenture supported by
osseo-integrated implant and bar-retained complete over denture supported by
osseo-integrated implant were made. The peak stress in mandibular peri-implant
bone tissue of the models were studied under the same loading conditions
vertically and horizontally by three-dimensional FEM stress analysis. The results
were as follows: (1) Both types of dentures retention can produce significant
stress effect on the peri-implant and other regions of the jaw bone and (2)
Magnetical retention is more beneficial to maintenance both of peri-implant bone
tissue and long-term success of denture supported by osseo-integrated implant
than bar retention does.
PMID- 10677963
TI - [Observations on before and after employ of screw of implant denture with SEM].
AB - The loss of screw is one of the clinic complication in MDIC implant denture
cases. The purpose of this study is to find the cause of loss of screw. The
authors has studied MDIC implant denture with SEM before and after employ of the
screw and found that the causes of screw loss were crevice corrosion and friction
pressure. Crevice corrosion may promote the loss of screw. Base the above
condition, it is necessary to select Ti-alloy screw and associat with
anticorrosive measure in MDIC implant denture construction.
PMID- 10677964
TI - [The application of dental stents in implant therapy].
AB - The improperiety of the location of implants would cause many difficulties to
prosthetic procedure. The function, appearance and long-term health of implant
denture would then be effected. Dental stents were used to resolve the above
problems for 30 cases of implant denture involved 74 implants in present study. A
radiographic stent with given diameter sphere can be used to eliminate distortion
and determine the bone quantity. A surgical stent can express the prosthetic plan
to surgeons during operation directly in the mouths of patients. It is very
helpful to the surgeons to take account of both the condition of jaw bone and the
future denture making. Holes, tunnels and windows on surgical stents can be used
as the guidances of drilling positions and directions. The surgical stents may
also be a useful reference to surgeons to make bone graft, do some changes in
surgical plan and even cancel the implant denture therapy when the situation of
jaw bone significantly differ from what the expectancy.
PMID- 10677965
TI - [A clinical study on treating the obstructive sleep apnea syndrome with
orthognathic surgery].
AB - When severe mandibular hypoplasia accompanying obstructive sleep apnea syndrome
(OSAS) were treated by the orthognathic surgery, the results were quite
successful not only in patients' profile, occlusion and functions, but also in
the subjective and objective evaluations related to OSAS. The paper summarizes
the methods and surgical procedures of treating OSAS with orthognathic surgery
through the diagnoses and treatment of a group cases suffering from severe
mandibular hypoplasia accompanying OSAS. Severe mandibular hypoplasia can cause
not only the deformity and the disorder of occlusion, but also the OSAS. The
advancements of mandible and hyoid with orthognathic surgery can improve the
patients'prfile, occlusion and expand the patency of upper airway, so it can cure
OSAS.
PMID- 10677966
TI - [Anterior segmental maxillary osteotomies (ASMO)].
AB - Anterior segmental maxillary osteotomies (ASMO) were performed with both the
Wassmund and downfracture methods in 15 patients and folloned-up regularly for 12
months The postoperative maxillary incisor edge point "Is" movements and
complications were examined. The results indicated that the point "Is" movement
was 1.66 +/- 0.77 mm postoperatively. No major complications occurred, The
stability of anterior segmental maxillary osteotomies was found to be acceptable.
PMID- 10677967
TI - [Dentin non-collagenous proteins and their induction of dentin cells].
PMID- 10677968
TI - [To raise critical care in China to a higher standard].
PMID- 10677969
TI - [Effect of recombinant bactericidal/permeability-increasing protein on pulmonary
cytokine mRNA expression in rats following hemorrhage and resuscitation].
AB - To determine the possible mechanisms underlying beneficial effect of recombinant
bactericidal/permeability-increasing protein (rBPI) on acute lung injury response
to blood loss, we used reverse transcription polymerase chain reaction to measure
pulmonary tumor necrosis factor (TNF), interleukin 6 (IL-6) mRNA expression in a
rat model of prolonged hemorrhagic shock (4.00 kPa, 180 min) followed by adequate
resuscitation. The results showed that systemic plasma endotoxin concentrations
elevated rapidly after a 180-min hemorrhagic insult (P < 0.05), and TNF, IL-6
mRNA expression in the lung were significantly increased at 2, 8 hours after
resuscitation respectively. However, treatment with rBPI resulted in almost
neutralization of plasma endotoxin values, remarkable reduction of TNF, IL-6 mRNA
levels following hemorrhage/resuscitation. Also, it was found that rBPI
administration markedly blunted the increase in pulmonary Evans blue dye
extravasation, concomitant with a significant decrease in lung myeloperoxidase
activity compared with the control group (P < 0.05-0.01). These data suggest that
local proinflammatory cytokine mRNA expression associated with gut origin
endotoxemia may be an important mechanism contributing to the development of
hemorrhage-induced lung injury. Treatment with rBPI is effective in inhibiting
marked TNF, IL-6 mRNA expression and ameliorating acute lung injury secondary to
severe hemorrhagic shock.
PMID- 10677970
TI - [The effect of anisodaminum and dexamethasone on microcirculation, TNF, LPO and
pathology in MODS].
AB - In order to evaluate the effect of anisodaminum and dexamethasone to the
microcurculation, TNF, LPO and pathology in MODS, we first established MODS model
using cecem ligature and perfuration of rabbit then divided it into four groups:
anisodaminum, dexamethasone, combined anisodaminum and dexamethasone and control.
After used the corresponding drugs we observed the change of microcirculation,
TNF, LPO and organ pathology. The result showed that microcirculation improved,
the serum level of TNF and LPO decreased, and the pathomorphological changes
lessensed. It is suggested that the combined use of anisodaminum and
dexamethasone may be a new way for treating MODS.
PMID- 10677971
TI - [The nosocomial infection in ICU: characteristics and prevention].
AB - In 84 consecutive patients who were treated in ICU, 35 had microbiological 5
data. 117 strains (bacteria: 77; fungus: 40) were isolated from 24 of the 35
patients for 97 times. The positive rate was 68.6%, or 28.6% of 84 patients. The
gram-negative bacilli were still the main source of nosocomial infection in ICU,
especially the pseudomonas aeruginosa, clostridium welchii, and E. coli, but gram
positive cocci, especially MRSA infection were also increased. Mycotic infection
increased very rapidly. 12 of the 24 patients were found a complicated mycotic
infection. Six of the 12 (50%) died. Candida tropicalis and candida guilliermondi
replaced candida albicans as the main pathogenic fungus. Sputum is still the most
important specimen source of positive culture, followed by wound drainage, blood,
urine, central venous catheter as well as feces. It is indicated that the
respiratory system is still the main focus of nosocomial infection, and mycotic
infection is most dangerous in ICU. Regular monitoring of microbial flora
changes, detection correct use of antibiotics by drug sensitivity test, adequate
surgical drainage, early and prevention of mycotic infection as well as
improvement of ICU design will prevent or minimize the nosocomial infection in
ICU.
PMID- 10677972
TI - [Prospective study of central venous catheter-related sepsis in critically ill
patients].
AB - To evaluate the incidence of central venous catheter-related sepsis (CRS) in
critically ill patients, we performed a prospective study of the central venous
catheters (CVCs) in ICU of the Peking Union Medical College Hospital from Jan.
1995 to March 1996. Of 151 CVCs, 13 (8.6%) had CRS, with an incidence of 16.7
episodes per 1000 catheter-days. Presence of infectious focus at catheterization,
catheter insertion site, duration of catheterization, and the decrease of body
temperature after catheter removal correlated with definite CRS, while difficulty
of insertion, body temperature at catheter removal, as well as the decrease of
body temperature after catheter removal correlated well with no CRS. The study
showed that CRS is a serious problem in critically ill patients. Careful
manipulation of CVCs is a major determinant in reducing the incidence of CRS.
PMID- 10677973
TI - [Clinical study of systemic inflammatory response syndrome and multiple organ
dysfunction syndrome in critically patients].
AB - We defined the epidemiology of systemic inflammatory response syndrome (SIRS) and
multiple organ dysfunction syndrome (MODS) in critically ill patients, and
evaluated the procession from SIRS to MODS and the therapeutic strategies. 230
patients were studied prospectively until discharge or death. On admission, the
morbidity rate of SIRS was 71.3%. The mortality rate of the patients with SIRS
was 18.9%. MODS was developed in 65 patients (28.3%), and 33 patients dided
(50.8%). In SIRS patients with non-infectious SIRS, sepsis and septic shock, the
morbidity rates of MODS were 22.8%, 61.1% and 85.7%, and the mortality rates were
11.4%, 30.6% and 50.0% respectively. The outcome of critically ill patients may
be improved if SIRS is early diagnosed and the body inflammatory response is
reglulated properly.
PMID- 10677974
TI - [Changes of plasma cytokines in patients with severe trauma and their
relationship with organ damage].
AB - We investigated kinetics of plasma TNF, IL-6 and IL-8 and their relationship with
organ dysfunction and endotoxemia in 17 patients with severe trauma in order to
further elucidate the role of cytokines in the development of organ damage and
their production mechanism after trauma. Plasma cytokine levels significantly
increased in trauma patients, and their plasma TNF was increased earlier. The
cytokines were positively correlated with ISS, cardiac and hepatic enzyme
activities, index of renal function, and plasma endotoxin levels. It is suggested
that TNF, IL-6 and IL-8 may participate in the development of organ damage after
trauma, and its release might be related to massive endotoxin translocation into
body at the early stage of trauma.
PMID- 10677975
TI - [Total knee replacement of severe flexion contracture deformities greater than 60
degree].
AB - The technique of total knee arthroplasty for the patients with severe flexion
contractures of more than 60 degrees is not clear. Recently, We have performed 37
total knee arthroplasties in 23 patients with flexion contracture of more than 60
degrees (average 77.97 degrees). Among them, 14 knees (37.9%) with flexion
contracture of more than 90 degrees, and 7 knees (18.0%) with 90 degrees flexion
fusion deformities. Significant improvements occurred after averaged 4.3-year
follow-up. Complications occurred in four patients: three had transient peroneal
nerve palsy, and one had temporary circulatory disturbance of the lower
extremity. They recovered after conservative therapy. We consider that severe
flexion contracture of more than 60 degrees is not a contraindication of TKR.
Staged bone resection and thoroughly soft-tissue release of the posterior capsule
and collateral ligament balance were the critical procedure. If necessary,
additional distal femoral condyle resection with posterior cruciate ligment
sacrifice can be considered.
PMID- 10677976
TI - [The structural changes of cortical bone beneath plate after rigid platefixation
and removal].
AB - We investigated the structural changes of bone under the plate after plate
fixation and removal. Twenty-four New Zealand white rabbits were plated on their
intact left tibiae with stainless steel plates and 4 animals served as controls.
The plates were removed 2 months after implantation in 20 plated animals, of
which, 4 were sacrificed immediately after plate removal and the other were
killed in successive groups of 4 each at 1, 2, 3 and 4 months after plate removal
respectively. The remaining 4 plated animals were killed at 6 months after
implantation. Bone samples were harvested and prepared for scanning microscopic
observation. Internal fixation with a rigid plate may lead not only to osteopenia
of the cortex under the plate, but also to disorganization of the cortex, in
which the mineral column and collagen fibers were oriented in a randomized
pattern. The regional osteoporosis could recover gradually after removal of the
rigid plate. However, the restoration of normal bone structure occurred later
than that of the bone mass. Delayed restoration of bone structure might be one of
the potential causes of refracture of the plated bone.
PMID- 10677977
TI - [Long-term results in 31 patients on total hemispherectomy modified for infantile
hemiplegic epilepsy].
AB - To overcome long-term complications of hemispherectomy, We modified its operative
method. The modified hemispherectomy was performed for 31 patients between 1985
and 1992. These patients were studied for 7 years after operation. The results
showed total control of seizures in 28 children with chronic epilepsy (90%) or
near-total control in the others. No deaths or delayed complications were noted
but improvement in behavior and hemiplegia. CT and MRI showed marked shift of the
remaining hemisphere. On brain-stem auditory evoked potentials, the latency of
peak I was not variant (P > 0.05). The method makes the insulation of the
subdural cavity from the ventricular system more reliable, and climates the
pathological conditions.
PMID- 10677978
TI - [Coronary artery bypass graft with internal mammary artery in 53 cases].
AB - Coronary bypass graft (CABG) with internal mammary artery was used (IMA) in 53
cases. They were treated medically but not effective. More than one time
myocardial infarctions occurred 44 cases, and 16 of them had complicated
ventricular aneurysm. All of them had moderate hypothermia cardiopulmonary bypass
except one, who was only subjected to anastomosis of left IMA to left anterior
descending branch without cardiopulmonary bypass. The mean grafts of this group
were 4.28 (lift ventricular aneurysmectomy was performed simultaneously in 4
cases). Operative death was occurred in 4 cases. Of the 35 cases which had been
followed for 6 months to 1 year, 30 were free of symptoms, 5 got better and had
more physical exertion. It is suggested that CABG with IMA is satisfactory.
PMID- 10677979
TI - [Surgical consideration in congenital partial atrioventricular septal defect in
59 patients].
AB - We report surgical anatomic characteristics, timing of surgery, corrective
methods of partial atrioventricular defect and prevention of complications. In
the past 15 years, we operated on 59 patients with partial atrioventricular
septal defect, associated with conduction abnormality in 39 patients, common
atrium in 2, mitral insufficiency (MI) in 54, tricuspid insiufficiency in 29,
andunroofed coronary sinus in 6. One patient could not wean from cardiopulmanary
bypass and died during operation. After surgery, 5 patients had moderate residual
MI, and 1 complete heart block. During 1 to 16 years of followup, all but 1
patient with class III (NYHA) had satisfactory results.
PMID- 10677980
TI - [Management of acute arterial occlusion of limbs: an analysis of 105 cases].
AB - 105 cases of acute arterial occlusion of limbs were admitted to our hospital from
march 1982 to September 1996. We compared the treatment results of the patients
with acute embolism and acute thrombosis. The limb-salvage rate of 86.8% in
patients with embolic occlusion was higher than that of 57.9% in patients with
thrombotic occlusion (P < 0.01), while the mortality rate of 8% patients
associated with thrombosis was lower than that of 15.7% with embolism (P < 0.01).
The results of limb salvage and mortality were related to different etiology of
acute arterial occlusion, embolism and thrombosis.
PMID- 10677982
TI - [Factors for postoperative persistent hypertension in patients with aldosterone
producing adenoma].
AB - We determined the factors for postoperative persistent hypertension in the
patients with aldosterone-producing adrenal adenoma (APA) in 53 patients with APA
who were followed up for average 3.1 years. All had normal serum potassium
concentration postoperatively. Blood pressure was normal in 37 patients (69.8%)
but 18.7/12.7 kPa or more in 16 patients (30.2%) with persistent hypertension.
Also compared were sex, age, history of hypertension, effect of reducing blood
pressure to antisterone, preoperative blood pressure, time of persistent
hypertension, serum potassium concentration, aldosterone concentration in 24 hour
urine, amount of PRA, and the type of operation. The results showed that an APA
patient aged 50 years or more appears to have a great chance of persistent
hypertension than an APA patient under age of 40 years, and the odds ratio is
3:1. There was a significant difference between the mean age for persistent
hypertension and for normal blood pressure, and varioas response of reducing
blood pressure to antisterone (P < 0.05). It is suggested that for an older APA
patient and the patient without of reducing blood pressure to antisterone, there
are other factors for hypertension such as renal veinlet change or renal
interstitial lesions except for hyperaldosteronism. We recommend renal biopsy
(using kidney puncture) at the operating table for those patients in order to
understand pathological change and guide treatment after operation.
PMID- 10677981
TI - [Prenatal diagnosis and early treatment of congenital urological deformites].
AB - 11 children were treated in our hospital from 1987 to 1990 for the congenital
urological defomities. They were diagnosed prenatally and were treated early
after birth, and 5 of them were compared with 28 children who had been treated in
the same hospital in the same stage for hydronephrosis due to the congenital
pelvic-ureter stenosis, that was not prenatally diagnosed. Analysis of a series
of renal functional test, special methods and clinical study, showed the
possibility of prenatal diagnosis and the necessary of early treatment of
congenital urological deformities.
PMID- 10677983
TI - [Quantitative electroencephalogram monitoring the depth of anesthesia during skin
incision].
AB - We investigated the EEG parameter changes of skin incision during different depth
of sevoflurane/nitrous oxide analgesia. 65 ASA physical status I patients (aged
34 +/- 12 yr) scheduled for elective abdominal surgery were studied. The tracheal
of each patient was intubated and the lungs were ventilated. Patients were
randomly assigned to one of three groups. Anesthesia was maintained with 1%
(group I n = 25), 1.5% (group II n = 20) or 2% (group III n = 20) end-tidal
sevoflurane concentration in 66% nitrous oxide. Each of the concentration levels
was maintained for at least 15 minutes before surgical incision. The EEG
electrodes were placed on each patient in a front-oparietal montage (Fp1- A1, Fp2
A2) referred to Cz. EEG was recorded during 3-min period before incision.
Hemodynamic variables were also monitored. Inadequate anesthetic depth was
defined as patient movement in response to a 5-cm skin incision. The ventilation
was controlled to maintain normocapnia (PETCO2 5 +/- 0.04 kPa). The data were
analysed using ANOVA, liner correlation analysis and t-test. A significant
difference between EEG parameters (SEF, BIS,) and skin incision responsive rate
were found among the three concentration groups (P < 0.01). There were no
difference of hemodynamics among the three groups. Patients who moved at incision
also had significantly higher SEF, BIS leveles compared to non-movers (P < 0.01).
Quantitative EEG determinants were correlated well with the end-tidal sevoflurane
concentration and were a useful predictor of patient movement in response to skin
incision during sevoflurane/nitrous oxide anesthesia.
PMID- 10677984
TI - [Early diagnosis and treatment of mesenteric venous thrombosis].
AB - From 1967 to 1995, we treated 16 patients with mesenteric venous thrombosis
(MVT). Major complaint was abdominal pain, and 13 patients had predisposing
factors. One was diagnosed by color Doppler ultrasonography and cured by
anticoagulant, 14 were misdiagnosed, 7 died postoperatively, and 8 cured. Early
diagnosis lies on predisposing factors, discordance of symptoms and signs, color
Doppler ultrasonography, CT, and angiography. Early operation for removing the
involved intestine with its mesentery and early application of anticoagulant are
essential to decrease the mortality and recurrence.
PMID- 10677985
TI - [Nutritional rehabilitation for patients with extreme short bowel].
AB - The prolonged parenteral nutrition and intestinal transplantation is considered
as useful therapeutics for patients with extreme short bowel. However, both of
them are still limited. We report the results of nutritional rehabilitation for
patients with extreme short bowel. Three patients whose residual intestines were
65 cm, 75 cm and 30 cm respectively were treated with growth hormone, glutamine
and a fiber-containing diet for 2-3 weeks. The nutritional status of patients and
the absorptive ability of residual intestine in these patients improved obviously
after the treatment. This nutritional rehabilitation regime offers a new
potential method for patients with short bowel syndrome.
PMID- 10677986
TI - [Liver resection after transcatheter hepatic arterial chemoembolization for
hepatocellular carcinoma and curative effect analysis].
AB - To study the therapeutic result of hepatic resection for those hepatocellular
carcinoma (HCC) shrunked after transcatheter hepatic arterial chemoembolization
(TACE) in the patients with unresectable HCC, authors reported 59 patients with
HCC. Among the 59 patients, the maximum diameter of the tumor was 5.6 to 20.0 cm
prior to the first TACE, mean 9.43 cm. The patients underwent 1 to 6 times of
TACE, mean 2.9 times. The tumor diameters were reduced to 3.29 cm prior to
operations. The duration between the last TACE treatment and sequential resection
varied from 1 to 7 months, mean 2.53 months. Of the 59 patients, 35 patients'
serum alpha-fetoprotein (AFP) levels were elevated. AFP levels returned to normal
after TACE treatment in 13 patients. Of the patients, liver segmentectomy,
combined liver segmentectomy or partial liver resection was performed in 56
patients, left trilobectomy in 2 and left hemihepatectomy in 1. Tumor necrosis
ranged from 40% to 100% pathologically and complete tumor necrosis occurred in 9
patients. Of the 13 patients with AFP levels decreased to normal, 9 still had
microscopic living tumor foci. The 1-, 3- and 5- year survival rates were 79.7%,
65% and 56%, respectively. These results indicated that TACE treatment can
provide chance of tumor resection for those patients with unresectable HCC and
good results can be obtained.
PMID- 10677987
TI - [Clinical application of expanded radical operation with improved Whipple
technique to late pancreas head cancer].
AB - Studies on the expanded eradicative and modified operation for treatment in
patients of late pancreas head cancer, so as to enhance the incised rate,
survival rate and life quality. Elective laparotomy was done in 20 patients.
Expanded eradicative operation was performed in 18 patients (portal vein excision
19, left outer leaf of liver 8, transverse colon 3). We have reconstructed the
portal vein 6, modified the Whipple operation, reconstructed the elementary tract
using Roux-Y interposed jejunum with orientatied intussusception of artificial
papilla. The incised rate of expanded eradication was 90% without postoperative
serious complications such as biliary and pancreatic leakage, massive hemorrhage
and operative death. The longest survival time was 5 years. The two-year survival
rate was 50%. Statistical analysis (t test and x2) showed signithicant
differences (P < 0.001).: (1) The exsion of original carcinomous focus may
relieve the patient's symptoms and can prevent portal vein from carcinomous cell
infiltration. (2) After enbloc incision with metastatic focus, sequential
treatment could be given successfully.
PMID- 10677988
TI - [Serial modifications of bacon's pull through resection for low rectal cancer].
AB - Four modifications of Bacon's pull-thru resection were undertaken to improve
postoperative defecatory control and to avoid the 2nd stage resection of the pull
thru colon stump. 54 cases of modified Bacon's rectal resection (9.64% of
sphincter saving resections) were performed between 1954-1989. The 1st
modification (1954) preserves the levator ani and the intact anorectal ring. The
2nd modification (1964) preserves the dentate margin and anal transitional zone
(acute anal sensation), thus greatly improving defecatory control. The 3rd
modification (1980) simplified intraanal resective procedure. The 4th
modification (1991) was to encircle and ligate the distal end of colon over a
sterilized corrugated intraluminal splinting tube (The other end of which is
already connected to a long latex tube prior to operation). The latex tube was
pulled out thru anus, until the colonic ligature reaches the Dentate margin, to
substitute for colonic pull-thru and to divert feces during & after operation, 4
8 fine stitches approximate the colon wall 1 cm proximal to the ligature, to the
cut edge of anal mucosa. The colon wall distal to the ligature sloughed in 7-10
days, the proximal colon has partially healed to the raw areas of anal canal
without infection. The 2nd stage colon stump resection is thus obviated and
hospitalization shortened. The postoperative anal function was good in 86.66%.
Modified Bacon's operation is indicated for very low rectal cancer when the
rectal remnant above levator ani after adequate resection is less than 1 cm which
is difficult for intraabdominal anastomosis. It extends the scope of sphincter
saving operation. It is a good substitute for Park's coloanal anastomosis.
PMID- 10677989
TI - [Treatment of atrial fibrillation using maze procedure by radiofrequency
ablation].
AB - From May 1994 to May 1996, 20 cases of atrial fibrillation were treated by means
of Maze procedure by radiofrequenncy ablation, at the same time 19 cases of these
patients were complicated with rheumatic heart valve disease and valve
replacement operations were perfomned, in the other case atrial septal defect was
repaired. Yoshio Kosakai's operation route was adopted in radiofrequency ablation
procedure. After operation 16 patients of atrial fibrillation resumed sinus
rhythm (80%), in 4 casess of atrial fibrillation sinus rhythm was unsuccessfully
restored, two patients remained atrial fibrillation, one patient was of atrial
flutter, the other was of nodal rhythm. Short time was needed in radiofrequency
ablation Maze procedure, average time increase of aortic clamping was 20.5
minutes, and there was no danger of hemorrhage related to this kinds of Maze
procedure. During 7-10 days after operation, there appeared superventricular
arrhythmia which might be related to ill-distribution of radiofrequency ablation,
and interference of atrial electric activity.
PMID- 10677990
TI - [Complications of osteotomy of vertebral arch and body in kyphosis].
AB - Among total 67 postoperative complications resulted from osteotomy of vertebral
arch and body in 439 cases of kyphosis, massive bleeding accounted for 2 cases
(0.46%); spondylolisthesis, 6 (1.37%); paraplegia caused by compressing of the
spinal cord, 5(1.14%); root pain, 6(1.37%); loss of correction, 26(29.55%);
leaking and subcutaneous accumulation of CST, 5(1.14%); incision necrosis,
16(3.64%); lifting of luque rod with peneatration through the skin, 1(0.23%).
Causes, treatment and prevention of these complications have been discussed in
this study. We emphasize that the operation should be done after the stable of
ankylosing spondylcitis. The degree of correction by osteotomy at one-level
should be limited.
PMID- 10677991
TI - [Reconstruction of anterior cruciate ligament using bone-patellar tendon
prepatellar periosteum free graft with impacting bone technique].
AB - In order to make full and effective use of patellar tendon (middle one-third)
during reconstruction of anterior cruciate ligament, we designed bone-patellar
tendon-tendon of quadriceps femoris free graft with impacting bone technique and
38 cases were treated by this method. Follow-up for 2 years and 7 months showed
that the clinical results were good. The exellent and good rate was 89.7%.
Clinical results indicated that the fixation of this reconstructive method was
firm and grafts in the joint cavity were patellar tendon tissue. The anterior
medial rotatory instability of the knee joint could be corrected with the same
graft that have enough length. The experience of acute rupture of anterior
cruciate ligament and the rupture of anterior cruciate ligament combined with
injury of meniscus were reported.
PMID- 10677992
TI - [Forty six cases of application of free femoris forelateralis flap in trauma].
AB - In serious scar or chronic ulcer caused by burn or trauma, skin graft can not be
survival and the local flap can not be found in these cases. Also skin grafts can
not improve function of these places. Free flap transplantation should be used in
these cases. Femoris forelateralis flap has some advantages. It is hidden from
view and there is no effect after it is taken. It has constant blood vessels
which are easy anastomosed. So the flap is more widely used. Forty-six cases were
given femoris forelateralis flaps (hand burn scar deformity 15 cases, foot scar
10, forearm or leg scar or tissue defect 8, leg or foot chronic ulcer 8, face or
neck tissue defect or serious scar 8). Forty-five cases (97.8%), were survival.
Only one case had necrosis. The key of survival is choice of the operative
indication, excellent anastomosis technique, good fixation postoperatively, care
observation, and timely handling. In vasculitis or phlebitis ulcer, the vessel
condition is bad. In old people, especial with heart or vessel diseases,
condition is also bad. We shoule be careful in these situations.
PMID- 10677993
TI - [Treatment of posterior urethral break caused by pelvic fracture and inflammatory
urethral stricture via laying three silicone tubers into urethra].
AB - We investigated a new approach for the treatment of posterior urethral break
caused by pelvic fracture and inflammatory urethral stricture. 7-10 days after
the operation of urethral realignment on patients with urethral break caused by
pelvic fracture or after forced dilatation of inflammatory urethral stricture,
three silicone tubers were laid into urethra and kept there for three months. In
66 cases of urethral break, the cure rate (58/66) was 87.9%, the improving rate
(2/66) 3.0% and the failure rate (6/66) 9.1%. In 15 cases of inflammatory
urethral stricture, the recovery rate was 100%. In this group of 81 cases, the
cure rate was 92.6% and failure rate was only 7.4%. This new therapeutic approach
proved to be simple, safe and effective. It could also dramatically reduce the
infection or the stricture of urethra.
PMID- 10677994
TI - [Use of appendix to restore a ureter: report of 2 cases].
AB - In two cases the appendix was utilised as a substitute for part of the left
ureter. Case one used the appendix as a conduit from the upper left ureter to the
right one to treat the megaureter, and the other one used the appendix as a
connection to join the two transected openings of the left ureter to treat the
obstruction caused by the chronic ureteritis of the left ureter. Long-term
observation after the operation showed satisfactory functions of kidneys. We
suggested that the appendix is an autologus tissue whose active peristalsis,
little mucous absorption along with its easy performance make this method highly
valuable and practical.
PMID- 10677995
TI - [High-methylprednisolone treatment in acute cervical spinal cord injury without
fracture and dislocation].
AB - We compared methylprednisolone (MP), surgical decompression and both in acute
cervical spinal cord injury without fracture and dislocation. The study involved
32 acute cervical spinal cord injury without fracture and dislocation. MP was
given to 8 cases (high-MP group) within 8 hours after injury. 12 cases (surgical
group) underwent surgical decompression (anterior or posterior approach) within
48 hours after injury. 12 cases (combined group) were treated with MP within 8
hour of their injury and surgical decompression within 48 hours after injury.
Neurological function was assessed using scores according to international
standards for neurological and functional classification of spinal cord injury.
The results showed that combined group were more effective than high-MP or
surgical group, in the complete or incomplete spinal cord injury, and in motor
and sensory. The risk of such complication as gastrointestinal bleeding or
delayed wound healing is not significant with using high-MP.
PMID- 10677996
TI - [Video image analysis of AgNORs distribution in the testicular tumor].
AB - For the purpose of exploring the relationship between AgNORs and the biological
behaviour of the testicular tumor, the value of enumeration and image analysis of
AgNORs has been investigated in 10 normal testicular tissues and 49 cases of
testicular tumors. The major findings were: AgNORs value for number, area, mean
area, large partical number (LPN) and roundness in normal, benign and malignant
tumors had significant difference (P < 0.01). The former four parameters turned
larger when the tumor became more malignant, and they were significantly higher
in the good prognosis group than in the bad one. LPN was higher in stage III than
in stage I and II (P < 0.05), no difference was found between stage I and II.
Other parameters had no significant difference in each stage. These results
indicate that AgNORs is helpfull in differentiating the benign and malignant
testicular tumors, in determining the degree of malignancy and offering an
additional prognostic indicator in testicular tumors. Partical numbers, area and
LPN were more helpfull. It had no important value in differenciating each stage.
PMID- 10677997
TI - [The role and mechanism of fatty acids in gallstones].
AB - 18 Chinese cases and 37 Japanese cases of gallstones were analyzed according to
the procedure of extracting fatty acids in the gallstone. High perforamance
liquid chromatography (HPLC), showed that the contents of total fatty acid and
free fatty acid in pigment stones were obviously higher than those in black stone
or cholesterol stone. The ratio free saturated to total saturated fatty acid is
the highest in intrahepatic pigment stone and less in extrahepatic pigment stone,
which significantly differs from the latter two kinds of stones. This may
indicate that phospholipid in the bile catablizes into free fatty acids involved
in the formation of stone under the action of phospholipase in the course of
pigment stone formation. The action of phosphoipase A1 is more important than
phospholipase A2.
PMID- 10677998
TI - [Experimental study on the treatment of smoke inhalation injury with lung lavage
and exogenous pulmonary surfactant].
AB - To investigate the prevention and treatment effects of lung lavage and exogenous
pulmonary surfactant (PS) on endogenous surfactant system dysfunction and acute
respiratory failure caused by severe smoke inhalation, Wistar rats were randomly
divided into five groups: Group I, normal control; Group II, smoke inhalation;
Group III, smoke + lavage + PS + mechanical ventilation (MV); Group IV, smoke +
lavage + MV; Group V, smoke + MV. The lungs were lavaged with 30 ml/kg 0.9% NaCl
containing 100 mg/kg PS or same volume of saline via tracheal catheter at 5 min
after smoke inhalation, then the animals were placed on a ventilator for 4 h, and
observed until 24 h postinjury. The arterial blood gas levels, lung water volume,
static lung compliance (Cst), total protein and albumin contents in
bronchoalveolar lavage fluid (BALF), surface tension properties of BALF, and
fatality rate at 24 h were measured. Smoke inhalation caused a similar acute
hypoxia and severe carbon monoxide poisoning immediately in all injuried groups.
The animals in group II showed acute respiratory failure, serious high
permeability pulmonary edema, and surfactant system dysfunction. The surface
tension properties of BALF, Cst, and the oxygenation were significantly improved
with lung lavage and exogenous PS treatment. The lung water volume, total protein
and albumin contents in BALF were decreased dramatically in this group. The
fatality rate at 24 h declined markedly only in group III. It was suggested that
lung lavage and exogenous surfactant treatment trestores effectively endogenous
surfactant function inhibited by smoke inhalation, improves lung function,
prevents high permeability pulmonary edema and respiratory failure, and decreases
the mortality in early stage after smoke inhalation injury.
PMID- 10677999
TI - [The mutual benefit role of pancreas and liver in combined transplantation].
AB - We study observed the mutual benefits of pancreas and liver in combined
hepaticopancreatic transplantation in rats. The result indicated that pancreas,
when transplanted with liver, could survive for a significantly longer time (13.4
+/- 1.01 days) than it transplanted alone (9.2 +/- 1.14 days) (P < 0.05). The
interstitial rejection was mild and its rejection grade was significantly
different from that of pancreas transplanted alone (P < 0.05, chi 2 test). The
liver, when transplanted with pancreas, regenerated with strong competence and
contact structure morphologically compared with liver transplanted alone. We
concluded that pancreas could be immunologically protected against rejection and
liver can be nutritionalized by pancreas in combined pancreas and liver
transplantation.
PMID- 10678000
TI - [The hepatic ischemia/reperfusion injury in cirrhotic rats].
AB - We assessed ischemia/reperfusion injury in carbon tetrachloride induced cirrhotic
liver as compared to normal liver in the rats. Hepatic vein nitric oxide (NO)
level was measured by method of luminol chemiluminensence, and portal vein
endotoxin level by limulus lysate with chyomogenic substract. In cirrhotic liver,
instead of diminishing the hepatic vein NO level increased significantly after
ischemia and remained high till 5 hrs postreperfusion. The portal vein endotoxin
level was also increased but to a higher level than that of normal liver. In
cirrhotic liver, ischemia/reperfusion injury is aggrevated as evidenced by higher
level of endotoxin, increased generation of NO.
PMID- 10678001
TI - [Maze procedure for chronic atrial fibrillation: electrophysiologic basis and
therapeutic effects].
PMID- 10678002
TI - [Pay more attention to the diagnosis and treatment of gallbladder cancers].
PMID- 10678003
TI - [Retrospective analysis of 830 extrahepatic biliary carcinoma].
AB - We retrospectively analysed clinical data of 830 patients with extrahepatic
biliary carcinomas treated in our hospital from 1956 to 1995. Among them, 601 had
gallbladder carcinomas, and 229 cholangiocarcinomas. The results showed that
extrahepatic bile duct carcinoma accounted for 6.77% of bile duct diseases.
Gallbladder carcinomas and cholangiocarcinomas accounted for 72.4% and 27.6% of
extrahepatic biliary carcinomas, while the mean age was 56.55 and 56.44 years
old, respectively. The sex ratio (male:female) was 1:2. 54 and 1. 46:1. The
operation rate and resection rate were 65.1% and 29.4% in gallbladder carcinoma
while 66.4% and 20.4% in cholangiocarcinoma. The incidence rate and resection
rate of extrahepatic biliary carcinomas were elevated.
PMID- 10678004
TI - [The long-term results of surgical treatment in 103 cases of hilar
cholangiocarcinoma].
AB - We studied characteristics including clinicopathology, operation style, late
survival rate of 103 patients with hilar bile duct carcinomas treated surgically
in our hospital between 1986 and 1996. The factors affecting surgical treatment
and late result of hilar bile duct carcinoma were analyzed. Of the 103 patients,
subjected to 66 (radical resection, 36; palliative resection, 30) were section,
and 37 (internal drainage, 11; external drainage, 26) were not. The total
resectional rate was 64.1%. Operative mortality was 2.9% for palliltive or
noresctive groups. In the radical resection group, the 1, 3 and 5-year survival
rates were 96.7%, 23.3% and 13.2%, and the longest survival time was more than 8
years, whereas in the palliative resection group, the 3-year survival rate was
only 3.8% and no one survived for over 5 years. In the unresected group, the
survival time of the patients with internal drainage was longer than that of the
patients with external drainage, but their viability was not improved
significantly. Most of them died within 12 months. We proposed the new clinical
types for hilar bile duct carcinoma. The pathological type in all patients
survived for over 5 years was welldifferatiated papillary or tubular
adenocarcinomas. The secondary operative rate in these patients was high. This
showed that the biological characteristic is very important for the long-term
results of bile duct carcinoma after operation.
PMID- 10678005
TI - [Complications of laparoscopic cholecystectomy in China: analysis of 39,238
cases].
AB - All Chinese articles published from November 1995 through April 1994 about
laparoscopic cholecystectomy were identified through CMCC. From 600 titles, 105
were read and left for analysis. Other 21 articles were from the 6th Biliary
Surgical Congress and this hospital. Severe complications of laparoscopic
cholecystectomy were identified in 409 patients (0.4%), bile duct injury
accounted for 0.32%, postoperative cystic duct leak and bile leak for 0.11% and
0.20% respectively. Peritoneal abscess and bowel injury occurred in 0.07% and
0.06% of cases, and postoperative hemorrhages were identified in 0.1% of the
cases. Fourteen (0.04%) postoperative deaths resulted from operative injury. The
data demonstrate that laparoscopic cholecystectomy is an operation which
associated with low morbidity and mortality. But bile duct injury is still a
problem, and complications of laparoscopic cholecystetomy can be minimized by
improving operative procedure.
PMID- 10678006
TI - [Effects of gallbladder ruptured under laparoscopic cholecystectomy on pulmonary
function].
AB - To assess effects of gallbladder ruptured and bile running out under laparoscopic
cholecystectomy on pulmonary function, we preprospectively studied 20 patients
without gallbladder rupture (group A), 10 with gallbladder rupture (group B), and
10 open cholecystectomy (group C). Significant differences were found in the
group B and C to all pulmonary function values compared with preoperative values
until the 5th to 7th postoperative day (P < 0.05). The group A showed only a
significant difference on the first day after operation (P < 0.05). There are no
significant differences between groups B and C. Comparing the group A with the
group B and C respectively showed a significant differences from the 1st to 7th
day (P < 0.05). This study confirms that the group A is superior to the groups B
and C. Postoperative peritonitis is also an important cause of pulmonary
dysfunction to reduce small airway function. Performing LC, we should try to
avoid rupture of gall bladder or hemorrhage to fasten the recovery of patients'
pulmonary function and reduce the chance of pulmonary complications.
PMID- 10678007
TI - [The comparison of conventional open cholecystectomy, laparoscopic
cholecystectomy and minor-incision cholecystectomy].
AB - To study the clinical value of minor incision for cholecystectomy, compared
conventional open cholecystectomy (300 patients, group A), alparoscopic
cholecytectomy (300 patients, group B), and minor-incision cholecystectomy (300
patients, group C) with regard to duration (day) of operation, amount of
intraoperative bleeding, complications, time (day) of gastrointestinal function
recovery, intravenous infusion, and expense and time (day) of hospitalization.
The results showed that the operating time, amount of bleeding, duration of
intravenous infusion, time of gastrointestinal function recovery and
hospitalization in group A were significantly different from those in group B and
C (P < 0.05), but the incidence in group A was lower than that in group B. The
operating time, amount of intraoperative bleeding, and the time of
gastrointestinal function recovery and intravenous infusion in group B were
similar to those in group C, but there was a high rate of intraoperative and
postoperative complication in group B (1.66%). There was no complication in group
C (P < 0.05). Comparison of the effects among group A, B and C showed that it was
superior in group C to those in group A and B.
PMID- 10678008
TI - [Detection of bacterial DNA from cholesterol gallstones by NP-PCR and its
clinical significance].
AB - To search for bacterial DNA sequences in cholesterol gallstones with negative
bacterial culture. We used nested primers polymerase chain reaction (NP-PCR)
technique to amplify bacterial gene fragments were amplified in vitro from DNA
extracted from cholesterol gallstones. Comparative 16S ribosomal RNA sequence
analysis was used for elucidation of bacterial identification. The gallbladder
gallstones of 30 patients were analyzed. Bacterial DNA was found in the stones of
26 patients. There was no difference either in cholesterol and water content or
in harboring bacterial DNA of gallstones. E. coli-related DNA fragments were
found in the stones of 8 patients (26.67%). Propionibacteria type DNA was found
in the stones of 7 patients (23.33%). Stones of 2 patients (6.67%) harbored
bacterial gene fragments with similarity of Streptococcus pyogenes. A more
heterogeneous sequence collection was found in 7 patients (23.33%) and could be
assigned to the multiple bacterial infections. Another stones of 2 patients
(6.67%) had bacterial DNA with lower molecularweight which might be related to
some unidentified bacteria. The results suggested that most cholesterol
gallstones harbor bacterial DNA. It is important to determine whether these
microorganisms are innocent bystanders or active participants in cholesterol
gallstone formation.
PMID- 10678009
TI - [Maze procedure for chronic atrial fibrillation associated with mitral valve
disease].
AB - From May 1995 to October 1996, 20 patients with mitral valve disease underwent
the maze procedure for chronic atrial fibrillation and mitral valve replacement
or mitral valvuloplasty. Epicardial mapping data demonstrated that the large
macrorecurre flutter circuit was located in left atrium (14/20) and complex
fibrillation in right atrium (18/20) of the majority of patients. No early death
occurred. 20 patients were followed up for at least 3 months (range 3-20 months)
and 14 patients for at least 1 year after operation, sinus rhythm and
atrioventricular synchrony were restored (100%), atrial fibrillation was not
induced by electrophysiologic study. The right and left atrial transport function
was preserved (100%) by Doppler echocardiogram tracings. One patient died from
acute necrotic hepatitis, 4 and half months after operation. Cox maze procedure
was modified, atrial flutter and atrial fibrillation never occurred. In this
study, the electrophysiologic mechanism of chronic atrial fibrillation associated
with mitral valve disease, indications of operation and clinical results are
discussed.
PMID- 10678010
TI - [VATS in malignant pleural effusions].
AB - Between November 1992 and October 1996, 20 patients with malignant pleural
effusions were submitted to VATS under general anesthesia. The overall positive
histological diagnoses were obtained through VATS (20/20). The malignant pleural
mesothelioma in 8 cases and metastatic cancers in 12 cases were
histopathologically confirmed. Talc pleurodesis was performed for all the cases,
and 18 patients gained lasting pleurodesis and the other 2 patients did not. The
failure of pleurodesis was due to that the lung could not reexpand to come into
contact with the chest wall. Postoperative complications included transient fever
and slight asthma in 2 cases, and the symptoms were relieved obviously after some
simple therapy to symptom. In conclusion, VATS has provided a high positive
diagnosis of patients with malignant pleural effusions not diagnosed by
conventional methods and good results in pleurodesis, but some operating skills
must be emphasized.
PMID- 10678011
TI - [Atypical manigioma].
AB - Most meningiomas have typical clinical and CT features. But some meningiomas
which have an atypical clinical and CT findings can lead to a wrong diagnosis.
The authors have reviewed 123 hospitalized patients with meningiomas which had
been pathologically diagnosed. Nine of them had atypical meningiomas according to
their histories, symptoms, signs and CT findings. All of these patients were mis
diagnosed as having gliomas or metastatic tumors. The authors analyed these cases
carefully and find the clues that may help to do an accurate preoperative
diagnosis.
PMID- 10678012
TI - [Scalp expansion in treatment of scalp defect with skull exposure].
AB - We repaired the scalp defect and skull exposure with scalp expansion. The
technique consisted of two stages. First, expander was implaned an then N. S
injected to its enough volume. The size of the expander was estimated by the
formula that 1 cm2 needs 4 ml expansive volume. The incision was made at normal
skin. Second flap was transferred. The expander was removed and the external
skull which was necrotic severed. There were five patient with eight flaps at
all, followed up for 6 months to 1 year. The hair grew. The results were
satisfactory. This method not only treated the disease, but also avoided
alopecia.
PMID- 10678013
TI - [Clinical observations on syringomyelia treated by syrinx-peritoneal shunting
with "T" tube].
AB - We 22 cases of syringomyelia were verified by MR and treated by syrinx-peritoneal
shunting with "T" tube. After the operation, the patients were reexamined by MR
and B ultrasound and confirmed that their shunting was functional. Symptoms of
the patients disappeared. But four patients got slight numbness in one leg or at
the saddle area. One patient suffered from a difficult movement in one hand. With
the exception of 6 patients, 16 showed that both of the newly and original
symptoms improved significantly. Follow up for 2 years with regular MR and B
ultrasound reexaminations was made. The patients resumed their work and study. MR
and B ultrasound reexaminations showed that all of syrinxes collapsed
significantly as the same as that after the operation immediately. These mean
that this kind of operation is useful and effective for most syringomeylias.
PMID- 10678014
TI - [Investigation on matrix degrading enzymes of lumbar intervertebral discs].
AB - Changes in the macromolecular matrix of the intervertebral disc may predispose to
biomechanical failure of the disc. Such changes would involve extracellular
enzymes capable of altering the collagen and proteoglycan of the disc matrix. In
this study, tritium-labeled type I collagen was used as a substrate to estimate
the activity of collagenase in the discs of 41 cases of lumbar disc protrusion
(LDP) patients by surgical intervention. The annulus fibrous (AF) and nucleus
pulposus (NP) were measured separately. 34 normal discs harvested by autopsy
acted as controls. For estimation of relative neutral proteinase content of 6
normal and 16 degenerated lumbar discs, polyacrylamide gelelectrophoresis (PAGE),
heat-denatured collagen as a substrate, and photo-density scanning with peak area
autocalculating system were adopted. The results presented that both AF and NP of
the normal discs had a similar lower collagenolytic activity and a very limited
activity of neutral proteinase, while the degenerated discs showed a higher
activity, especially in the degenerated NP. The extruded type of LDP got a higher
collagenolytic activity in NP than that of the prolapsed LDP. The fact showed
that the matrix degrading enzymes play a very important role in the process of
lumbar disc degeneration. The difference of disc degeneration is the biochemical
basis of different clinical types of LDP. Matrix degrading enzyme system is a
very complexed multienzymatic system. Other neutral proteinases may join this
system besides the collagenase.
PMID- 10678015
TI - [Influence of human bone morphogenetic protein (hBMP) on the articular cartilage
pieces cultured in vitro].
AB - To understand the influence of hBMP on the articular cartilage, we investigated
the expression of osteocalcin (BGP) and hBMP, and calcium deposit in cartilage
matrix induced by hBMP. Under the inducing of hBMP, chondrocytes in cartilage
pieces begun to express BGP and hBMP. The hBMP promoted calcium deposition in the
cartilage matrix, hBMP made some chondrocytes further differentiat into
osteoblast-like cells. We consider that these osteoblast-like cells might be
other source of osteoblasts in endochondral osteogenesis.
PMID- 10678016
TI - [The experimental studies of immune response of antigen-extracted bovine
cancellous bone grafting].
AB - Xenogeneic bone grafting is an alternative to autogeneic bone grafting, but the
intense immune rejection makes its clinical practice limited. We performed
lymphocytes proliferation assay, enzyme-linked immunosorbent assay, and
histological observation to evaluate the levels of cellular and humoral immunity,
and the tissue reaction to the grafting of BALB/c mice receiving fresh bovine
cancellous bone (FCB), antigen-extracted bovine massive cancellous bone (MCB),
antigen-extracted bovine granular cancellous bone (GCB). Lymphocyte proliferation
was increased in an early phase of the grafting and persisted for a long period
in FCB group. Meanwhile higher levels of specific antibody were detected. In MCB
and GCB groups, lymphocyte proliferation and specific antibody production were
not ascended and no significant difference was observed between MCB and GCB
groups in these immunological responses. There were no appreciable histologic
signs of immune or foreign body reaction both in MCB and GCB groups. The results
suggested that MCB, GCB were characterized less antigenicity and can be used as
osteoconductive material or a carrier of bone growth factors.
PMID- 10678017
TI - [The etiologic role of thermal injury on the induction of NO and NOS in plasma,
burned wounds and visceral organs].
AB - Using a 35% TBSA burned animal moedl, we investigated the levels of NO contents
(nitritc concentration assay) and NOS (hemoglobulin absorbent optical density
test) in the burned wound, circulation, as well as five visceral organs which
inluded heart, lung, liver, kidney and intestine mucosa. Samples were obtained
from scalded male Wistar rats at 1 hour postburn (PBh1)PBh3, PBh8, PBh12, PBh24,
PBh48 and PBh72, respectively. Samples of sham burned rats were obtained as
controls. The plasma level of NO concentration was decreased within 72 hours
postburn especially at PBh3, 8, 12, 24, 48 (P < 0.05 to P < 0.01). This was in
agreement with our findings in the ESR assay. The cutaneous NO cotents was 3.8 to
57.8 times higher than that of plasma and other visceral organs. It is thus
possible for burned skin tissue to be an important sites in the production of NO.
However, the cutaneous NO might have little systemic influences and can only be a
local fator due to its short half-life. The close relationship of changes in the
NO and NOS in five visceral organs postburn provided strong evidence on the
function of NOS as NO premerase.
PMID- 10678018
TI - [Drug resistance and its mechanism of intrinsic drug-resistant cell line GRC-1].
AB - In order to probe the characteristics of drug resistance and its mechanisms of
renal cell carcinoma, drug-resistant spectrum of renal cell carcinoma cell line
GRC-1 was detected by in vitro MTT colorimetric assay, the mechanism of drug
resistance in GRC-1 was also studied by the methods of both immunocytochemistry
assay and flow fluorescence cytometry. The results demonstrated that GRC-1 was
cross-resistant to adriamycin, vincrinstine, etoposide and carboplatinium, both
mdr1 gene product P-glycoprotein and GST-pi which was an isozyme of glutathione S
transferases were expressed in GRC-1. The accumulation of net intracellular drugs
of GRC-1 was less than that of drug sensitive breast cancer cell line MCF7, and
the ability of pumping drugs out of cells was higher than that of MCF7. The
results suggested that there is an intrinsic multidrug resistance in GRC-1 cell
line, and both P-glycoprotein and glutathione systems play a role in the
development of drug resistance for GRC-1. GRC-1 is an ideal target cell line for
the study of drug resistance.
PMID- 10678019
TI - [Possibility of gene therapy in orthopedics].
PMID- 10678020
TI - [The different influences of splenectomy plus ligation of pericardial vein and
shunt on portal hypertensive gastropathy].
AB - A prospective and controlled study has been made to probe into the different
influences of splenectomy plus ligation of pericardial vein (SPLPY) and shunt on
portal hypertensive gastropathy (PHG). 26 patients with cirrhosis of liver and
portal hypertension admitted from January 1994 to April 1996 were randomized into
two groups. One group was treated with SPLPV (15 cases), and the other shunt (11
cases). Gastroscopy was made in all patients pre- and postoperatively to observe
the changes of gastric mucosa. It has been shown that SPLPV exacerbate PHG (P <
0.05) and the shunt has an opposite effect (P < 0.05). We consider that it is
necessary to modify SPLPV and reevaluate the clinical effects of the both.
PMID- 10678021
TI - [Clinical study of expandable venous stents for treatment of Budd-Chiari
syndrome].
AB - Expandable venous stents is a new method for treatment of Budd-Chiari syndrome
(BCS). Ten cases of BCS underwent expandable venous stents in inferior cava vein
or/and in hepatic vein, or/and intrahepatic portosystemic shunt according to the
location and the extent of lesion. Expandable venous stents were successful in
all patients. No serious procedure-related complications were observed. The
symptoms and signs disappeared. Portal pressure and inferior cava vein pressure
gradient reduced immediately after treatment. The blood in stents flowed quickly.
During follow-up of 1-21 months, rebleeding was observed in one case. The
stenoses of intrahepatic shunts and inferior vena vein respectively occurred in
two cases requiring repeat intervention. Therefore, expandable venous stent is
safe and effective in patients with BCS, and will be of great value in wide
application and further study.
PMID- 10678022
TI - [Clinico-transcranial Doppler sonography monitoring on vasospasm and delayed
cerebral ischemia after resection of intracranial tumors].
AB - The occurrence of vasospasm and delayed cerebral ischemia after resection of
intracranial tumor has not received extensive attention clinically, and is often
misdiagnosed and improperly treated as surgical brain damage or brain swelling.
Seventy-two patients with intracranial tumor were continuously monitored pre- and
postoperatively by means of neurological assessment and transcranial Doppler
sonography. Vasospasm was found in 35 (48.6%) patients (18 mild, 13 moderate and
4 severe vasospasm). No significant difference among age, sex, surgical
approaches, pathological diagnosis, duration of surgery, amount of blood loss and
transfusion during surgery were found, but significant difference was seen in
cisternal hemorrhage on CT scan and the amount of blood in cerebrospinal fluid.
The cause and features of postoperative vasospasm were discussed, transcranial
Doppler sonography played an important role in the diagnosis of vasospasm. To
decrease the amount of blood in basal cistern by microsurgery in preventing
vasospasm and to differentiate vasospasm from brain swelling are helpful to
confirm the coexistent or causal relation based on neurological assessment, CT
imagine, transcranial Doppler sonography and ICP monitoring both in deciding
therapeutic strategy and successfully controlling vasospasm. Nimotop played a key
role in preventing brain damage from vasospasm and cerebral swelling.
PMID- 10678023
TI - [Influence of idiotypic network regulation on renal transplant].
AB - Pretransplant sera from 68 patients were tested for antiidiotypic antibodies
(Ab2) and anti-antiidiotypic antibodies (Ab3) by lyphocytotoxicity inhibitory and
potentiating assay. In the first six nomths, 6% of the patients in the Ab2 group
had had a rejection episode compared with 21% of the patients in the no antibody
(P < 0.01), whereas patients in the Ab3 group had significant rejection episodes
(67%) compared with no antibody group (P < 0.01). These results suggest that Ab2
can introduce recipients tolerating the graft in some degree and patients with
Ab3 are of high risk of graft rejection.
PMID- 10678024
TI - [The significance of use of anti-intrarenal artery spasm in renal allografts with
HAR like manifestation].
AB - In the past, severe ischemia of unknown cause in renal allografts after
restoration of renal blood flow was regarded as a sign of hyperacute rejection
(HAR) or other irreversible lesions, so that the grafts were usually excised
during the operation. From January, 1994 to April, 1996, 8 cases of renal
allografts with ischemia as described above were encountered in our hospital.
Measures of anti-intrarenal artery spasm (IRAS) were taken to those grafts.
Except that three grafts of HAR were excised, ischemia disappeared an renal
functions recovered in 5 grafts. It suggested that ischemia of the five grafts
was caused by IRAS. Thus, IRAS should be taken into account for renal allografts
with severe ischemia of unknown cause and early anti-IRAS is essential for the
diagnosis and treatment of IRAS.
PMID- 10678025
TI - [Diagnostic value of CD44 splice variants in urine exfoliated cells of bladder
cancer].
AB - To study the early and non-invasive diagnostic value of CD44 splice variants in
urine exfoliated cells of bladder cancer. We used reverse transcriptionpolymerase
chain resection (RT-PCR) and southern blot hybridization to detect CD44 splice
variants in exfoliated cells in 40 urine samples (20 bladder cancers, 20 non
neoplastic controls), and compared with the results of urine cytology on the same
set of samples. 90% (18/20) of the urine samples of bladder cancer showed
overexpression of CD44 splice variants while none of the 20 controls did so. This
method not only has a sensitivity of 90% (18/20) which was much higher than that
of 65% (13/20) by using urine cytology, but also is non-invasive and comfortable.
The results suggest that CD44 splice variants in exfoliated cells in urine
samples are a new tumor marker for early and non-invasive diagnosis of bladder
cancer.
PMID- 10678026
TI - [Hepatic resection and hepatic arterial chemoembolization for primary liver
carcinoma].
AB - Three hundreds of primary liver carcinoma (PLC) were subjected to hepatic
resection and hepatic chemoembolization (HACE). Among them, hepatic resetion was
performed in 106 cases, and HACE in 194. The two-stage operation after HACE was
performed in 23 cases. Hepatitis B antigen was positive in 69.8%. PLC with
cirrhosis accounted for 81.6%. The effect of hepatic resection was superior to
HACE. The cause of early local recurrence after HACE can be a valuable therapy in
the hepervascular PLC. However, HACE should be unsuitable for ischemic PLC.
Quantitative estimation of hepatic resection of PLC with cirrhosis was dependent
on 5 parameters (ALT, serum bilirubin, PT and R15TCG), and morphological changes
of cirrhotic liver.
PMID- 10678027
TI - [Primary curative incision in the treatment of perianorectal abscess].
AB - More than 50% of the patients with perianorectal abscess treated with traditional
incisional drainage will lead to fistula formation postoperatively. We present a
procedure of primary curative incision for treatment with perianorectal abscess
without fistula formation. The result of primary curative incision in comparison
with traditional incisional drainage in a randomized control study showed that
the incidence of postoperative fistula formation and recurrent abscess was 2.56%
in the former and 56.25% in the latter. The key points of the procedure were
discussed in detail and the causes and prevention of the disease occurred after
injection of sclerotic drugs for hemorrhoids were also discussed.
PMID- 10678028
TI - [Experimental and clinical study on gastroesophagostomy after cardiectomy of
gastric stump].
AB - 60 hybrid dogs, divided into 2 groups, were subjected to subtotal gastrectomy in
B-I and B-II pattern respectively. 20 weeks later, resection of cardia and fundus
ventriculi and the gastric remnant esophagus anastomosis was performed. There
were more omentum blood vessel embedments about the gastrojejunostomic and
gastroduodenostomic stoma and collateral circulation was plentiful. In 1980,
there were 25 patients with cardiac cancer of the gastric stump with an average
period of 13 years and 3 months following subtotal gastrectomy and a mean age of
59.1 years. 19 patients were subjected to exploratory thoractomy, 17 resection of
cardia and fundus of gastric stump and gastroesophagostomy (9 to tunnel
gastroesophagostomy and 8 end-to-side esophagogastrostomy). The largest tumor was
5 cm x 4 cm. Except for a death due to intestinal obstruction following
operation, the others attained a good recovery. Resection of cardia and fundus of
gastric stump and gastroesophagostomy can be carried out for patients with
cardiac cancer for gastric stump, which is in line with the principle of
conservation surgery.
PMID- 10678029
TI - [Video-assisted thoracoscopic bullectomy for giant bullous emphysema].
AB - Giant bullous emphysema often has serious dyspnea, and is difficult to manage.
Bullectomy through thoracotomy for this disease carries a substantial morbidity
and mortality. The aim of this report is to investigate the feasibility and key
techniques of video-assisted thoracoscopic bullectomy for giant bullous
emphysema. From December 1995 to October 1996, 6 patients with giant bullous
emphysema underwent bullectomy by means of video-assisted thoracoscopy. Giant
bullae occupied at least 50% of hemithorax, and 4 of which occupied more than
90%. According to Hugh-Jones dyspnea criteria: grade II in 3 cases, grade III in
2 and grade IV in 1, four bullectomies were done by video-assisted theracoscopy
alone. One bullectomy and one left pneumonectomy were performed by combination of
theracoscopy and a 8 cm thoracic incision. All procedures were accomplished
successfully. The operating time ranged from 65 to 150 minutes. There was no
blood transfusion and perioperative complications. Lung function was
significantly improved in all patients after surgery (all better than grade II).
Thoracoscopic bullectomy for giant bullous emphysema is a technically feasible
and safety procedure, especially for group I and group II patients. However,
there are still many problems to be resolved in thoracoscopy for group III and IV
giant bullous emphysema.
PMID- 10678030
TI - [Diagnosis and treatment of mediastinal tumor by VATS].
AB - Twenty-eight patients with mediastinal tumors underwent thoracoscopic operation,
among which 22 received the resection of mediastinal tumor including mediastinal
cyst (9), teratoma (5), neurogenic tumor (5), thymoma (1), vagothyrophyma (1),
and lipoma (1), and 6 patients received diagnostic biopsy of mediastinal tumor.
The preliminary results were promising. The experience of thoracoscopic operation
on mediastinal tumor are discussed in this article and VATS is regarded as a new
diagnostic and treating method which is superior to conventional thoractomy on
some kinds of mediastinal diseases.
PMID- 10678031
TI - [Treatment of carinal resections for primary pulmonary carcinoma].
AB - Threeteen patients of lung cancer of center type underwent carinal resections in
our department from January 1985 to December 1996. There were 3 patients, T3N2M0
and 10 patients, T4N2M0. Palliative resections were performed for 3 patients and
radical resections, for 10 patients. Carinal resection with right pneumonectomy
was done in 3 patients, part carinal resection with right pneumonectomy 6
patients, part carinal resection with left pneumonectomy 1 case, and part carinal
resection with right sleeve upper and middle lobectomy 3 patients. There were no
operative complications and deaths. The 3-year survival rate was 54% and the 5
year survival rates, 30%. One patient has survived for 8 years. The satisfied
results of operative therapy were followed when no lymph node metastesis in
mediastinum and mass could be resected.
PMID- 10678032
TI - [Treatment of esophageal and cardial stricture with TiNi memory alloys srent].
AB - A thermal-shaped memory metal stent, which is made of Nitinal, used in 95
patients with malignant tumors and 35 patients with anastomosis stenosis tumor
resection. All patients had no opportunities of surgical operation and no
response to dilation radiotherapy, chemotherapy, lasertherapy and traditional
Chinese medicine. Dysphagia ameliorated in all patients after stent therapy. The
mean dysphagia grade varied from 3.71 +/- 0.45(range 3-4) to 1.08 +/- 0.59 (range
0-2)(P < 0.01). Complications occurred in 49 patients (31.5%), including chest
pain in 36, local bleeding in 5, tumor overgrowth in 4, stent migration in 2, and
food obstraction in 2. In summary, treatment with placement of a Nitinol stent is
effective, safe and simple in our patients with dysphagia which were due to
malignant esophageal and cardiac strictures and is feasible for some benign
esophageal and cardiac strictures as well through our clinical practice and
observation nearly three years.
PMID- 10678033
TI - [Measures for decreasing the early mortality after valvular replacement
cardiovascular surgery].
AB - To probe the effective measure for decreasing the early mortality after
artificial valvular replacement. We analyzed the cause of death among 1215
patients receiving artificial valvular replacement who were admitted in our
intensive care unit during 1990-1995. All 44 deaths were serious-illed patients
with preoperative cardiac functions of 3-4 degree. The factors affecting surgical
survival rate include: enhancement of patient's cardiac function before operation
and prevention of cardiac arrhythmia; a clear operational view and myocardial
protection, especially for reoperative patients; application of membrane
oxygenator; treatment of LCOS without delay, including intraveously administered
agents and IABP used promptly when necessary; prevention and treatment of
postoperative cardiac arrhythmia; strict, intensive care and synthesized
treatment.
PMID- 10678034
TI - [Limb salvage and amputation in osteosarcoma: report of 31 cases].
AB - Three different types of operation were performed in 31 osteosarcoma patients,
and some cases received chemotherapy. It revealed, wide resection of tumor
supplemented with chemotherapy improved the survival and limb salvage rate
enormously. Chemotherapy and wide resection were all absolutely essential. The
life of prosthesis was long and most patients were satisfied with it.
Chemotherapy and limb salvage can enhance the survival and life quality in
patients with osteosarcoma.
PMID- 10678036
TI - [Auxiliary partial orthotopic liver transplantation in rats].
AB - A rat model of auxiliary partial orthotopic liver transplantation (APOLT) was
developed in this study. Under hemihepatic inflow and outflow occlusions, the
recipient underwent 75% partial hepatectomy before the liver graft comprising 30%
of the donor liver was implanted on the orthotopic site. Forty rat APOLT were
successfully performed. The 5-day survival rate of the recipient was 87.5% and
that of the graft was 75%. On the fifth postoperative day, the living graft
weight increased by 100%, the liver cell showed an active proliferation with a
diploid of deoxyribonuclease (DNA), and the liver cells in DNA-synthetic phase
accounted for 22.6 +/- 2.75%, significantly exceeding 12.22% +/- 1.48% of the
normal rat hepatocytes (P < 0.001). It may be concluded that the rat APOLT is a
more ideal animal model.
PMID- 10678035
TI - [Nutritional effects of glutamine-enriched parenteral nutrition on transplanted
small intestine in the rat].
AB - We evaluated the preventive effects of glutamine-enriched pareneral nutrition on
the atrophy and hypofunction of the transplanted small intestines in the rat.
Wistar rats received jejunal isografts and central venous catheters for
parenteral nutrition (PN) for ten days. Rats received either PN with 3% alanyl
glutamine or the PN with isonitrogenous ballanced nonessential amino acids.
Glutamine-enriched PN significantly increased mucosal villous height mucosal
thickness, crypt depth and villous surface area compared with the non-glutamine
PN. Normal enterocyte ultrastructure of the graft was maintained in the Glutamine
enriched group. Atrophied microvilli and broken mitochondrial crista were
observed in the control group. It was found that the amount of absorption of 15N
glycine was greater at the 1st, 2nd, 3rd hour in glutamine-enriched group than
that in the control. These results indicate that the glutamine-enriched
parenteral nutrition can promote the proliferation of mucosa, maintain the
ultrastructure and improve the amino acid absorption in the transplanted small
bowel in the rat.
PMID- 10678037
TI - [The effects of microwave heating on osteoinduction of demineralized bone matrix
in rabbits].
AB - In order to study the change of the autograft demineralized bone matrix, twenty
four new-Zealand rabbits were randomly divided into four groups of 2, 4, 8, 12
week by sacrified time, each group had 7, 7, 5, 5 rabbits. Autoradiography was
done for 2 rabbits in 2, 4 weeks respectively. The tibiae were removed by
amputation at knee joint level, then they were cleansed of marrow and periosteun,
cut into six pieces in length of 0.8 cm heated with microwave. Demineralized bone
matrix were made by defated and decalcified, and implanted into abdomenal walls
autograft. The results showed that the implants heated at 45 degrees C 30 min had
same osteoinduction as control group. The 65 degrees C 30 minutes heating may
reduce implant's osteoinduction slightly. The osteoinduction of the groups heated
75 degrees C for 30-60 minutes were impaired severely. The implants boiled at 100
degrees C 30 minuts had no osteoinduction at all, 65 degrees C 30 minutes may be
a "safty" limit when heat treatment on bone clinically. Otherwise, bone formation
ability would be reduced and remodelling was delayed.
PMID- 10678038
TI - [Advances in the etiology and pathogenesis of congenital megacolon].
PMID- 10678039
TI - [Advances in the chemotherapy of osteosarcoma].
PMID- 10678040
TI - [Emphasis on combined modality therapy of breast cancers].
PMID- 10678042
TI - [The correlation between tumor angiogenesis and lymph node metastasis in primary
breast carcinoma].
AB - To study the relationship between tumor angiogenesis and lymph node metastasis in
primary breast carcinoma. Agiogenesis was assessed by the microvessel density
(MVD) and expression of vascular endothelial growth factor (VEGF) using
immunohistochemical staining. Paraffin-embedded specimens from 70 patients with
primary breast cancer who had undergone radical mastectomy from 1984 to 1985 were
studied. Thirty-one patients had histologically proven positive axillary lymph
node (N+). The axillary node negative (N-) group was composed of thirty-nine
patients. Microvessels per 200x (as MVD) and VEGF positively stained cancer cells
per 400x were counted with light microscope. MVD and VEGF expression were higher
in tumors with N+ showed than those with N-, MVD and VEGF expression were higher
in N+ than in N-. MVD and the expression of VEGF are highly correlated with
metastasis in primary breast cancer, which may serve as a parameter for
determining tumor biological, metastatic potential and prognosis.
PMID- 10678041
TI - [Prognosis and adjuvant chemotherapy of axillary node-negative breast cancer
patients].
AB - The significance of postoperative chemotherapy was studied in 439 cases of
unilateral primary breast cancer which were proved histologically with no
axillary lymph node metastasis. The survival rate was analyzed by life table
method. The prognosis of node negative breast cancer patients was mainly
associated with tumor size. 10 year survival rate of patients with tumor less
than 3 cm treated operativel and by operation combined with chemotherapy was
92.60% and 94.13% respectively. If tumor size was larger than 3 cm, the ten year
survival rate of the patients treated operatived was 79.89%, and that of the
patients with combined theropy 96.02%. The prognosis was statistically different
between the two groups. As to age, status of menopause, pathologral type, kind of
surgery and status of ER, the prognosis of patients treated by combined therapy
was better than that of patients treated by operation alone. The postoperative
chemotherapy was not significantly beneficial to breast cancer patients with
tumor less than 3 cm.
PMID- 10678043
TI - [The prognostic values of FCM determination of primary tumor and axillary lymph
node of the patients with breast cancer].
AB - Using Flow cytometry, we determined the ploidy and SPF on the primary tumor and
axillary lymph node of 58 patients with breast cancer. Follow up for 5 years
evealed that 23 patients had recurrence. 21 of them died. We conclude that the
patients with aneuploid and high SPF have a higher relapce rate than those with
diploid and low SPF, especially in those with advanced stage tumor or metastatic
lymph node. It seems that ploidy and SPF of primary tumors affect more strong the
prognosis of the patient than those of axillary lymph node. The probable cause of
the recurrence of diploid tumor patients suggest post operation treatment for the
patients with aneuploid cancer.
PMID- 10678044
TI - [Therapy for 29 sarcoma of the breast].
AB - We discuss the best therapeutic method for sarcoma of the breast. The data of all
cases treated from March 1964 to May 1994 were analyzed retrospectively. Of all
cases, 7 died, 9 recurred, and 15 survived more than 15 years and 5 over 20
years. The follow-up time was 4 months to 25 years. Most sarcomas were
pathologically proved. The best therapeutic method was operation. The sarcomas of
all cases must be extensively resected including surrounding tissues. The
recurrent sarcoma should be resected again. The axillary lymphnodes should not be
eliminated when lymphnodes is not discovered.
PMID- 10678045
TI - [Male breast cancer: experience with 42 cases].
AB - Data were collected on 42 men with breast cancer treated at department of
surgery, cancer hospital in Shanghai between 1960 to 1996. We studied several
clinical features and the importance of established prognostic factors.
Observation for 76 months showed the 5 year survival rate was 57.1%, and the
total survival was 64.3%. Prognostic indicator analysis showed that only axillary
lymph node status proved to have a prognostic impact. Tumor size, age did not
show any prognostic influence. Because of less cases, we can not use Cox's
regression model to do multivariate analysis.
PMID- 10678046
TI - [Micrometastasis of colorectal carcinoma in bone marrow with immunohistochemical
staining].
AB - From April 1994 to April 1996, immunohistochemical technique was used to detect
micrometastasis of patients with colorectal carcinoma with monoclonal antibody to
epithelial membrane antigen (anti EMA). Positive cells were found in their bone
marrow in 23 of 57 cases, including 14 in 34 patients with colonic carcinoma
(positive rate 41%) and 9 in 23 patients with rectal carcinoma (positive rate
39.1%). The positive rate was 40.4%. Statistical analysis showed that the
modified Dukes stage of the cancer, the pathological type of carcinoma and the
age of the patients were correlated with the positive rate, but the primary
locations of the cancer were not. This method can be used to identify the extent
of the cancer and direct clinical comprehensive treatment for colorectal
carcinoma.
PMID- 10678047
TI - [The effect of low temperature on von Willbrand factor expression of cultured
human umbilical vein endothelial cells].
AB - We investigated the effect of low temperature on von Willbrand factor (vWF) of
endothelial cells (EC) and the importance of low temperature in thrombogensis. We
used the immunocytochemistry staining and image analysis system to study the
expression of vWF of cultured human umbilical vein endothelial cells in low (33
degrees C) and normal (37 degrees C) temperature conditions. The expression of
von Willbrand factor of EC was higher in low temperature than in normal
temperature (P < 0.001). The low temperature plays an important role in
thrombogensis.
PMID- 10678048
TI - [Nucleolar organizer regions enumeration in testicular teratoma].
AB - To differenciate the benign and malignant testis teratoma. We investigated the
value of AgNORs enumeration in 10 normal testis tissues, 6 benign teratomas and 7
malignant teratomas. The shape of the AgNORs in normal and benign teratoma was
round, regular, with clear boundary and even size, setting in the center or the
margin of the nucleus. In the malignant teratoma, the shape was irregular with
unclear boundary and uneven size, setting in the near center or scattered in the
nucleus. AgNORs enumeration: normal group: 1.56 +/- 0.17, benign teratoma: 2.40
+/- 0.26, malignant teratoma: 5.24 +/- 0.36. There was significant difference
between the two groups (P < 0.01). The range of AgNORs enumeration in benign and
malignant teratoma was separate. These results indicate that the mathod is
helpful in differentiating benign and malignant testicular teratoma, and may
provide an objective parameter.
PMID- 10678049
TI - [Expression of the bcl-2 and bax oncoprotein in TCC and its clinical
significances].
AB - To investigate the role of bcl-2 (an apoptosis suppressing oncogene) and bax (an
apoptosis accelerating oncogene) in the development of TCC. We investigated bcl-2
and bax expression by means of immunohistochemical technique in 34 cases of TCC
and in 9 cases of normal bladder tissue. Bcl-2 was positive in 44.44% of normal
bladder tissue and in 82.35% of TCC. Bcl-2 staining intensity was significantly
stronger in TCC than that in normal bladder tissue. Intensity and positivity of
bcl-2 also increased with increasing grades of TCC. Bax was positive in 88.89% of
normal bladder tissue and in 52.94% of TCC. Bax staining intensity was
significantly weaker in TCC than that in the normal bladder tissue. These results
suggested that increased expression of bcl-2 and decreased expression of bax in
TCC play an important role in the development of TCC.
PMID- 10678050
TI - [Fertility and related hormones before and after female successful renal
transplantation].
AB - To evaluate the level of hormones before and after female renal transplantation,
we measured pituitary gonadal hormones, estrovite, progestin, and prolactin in 25
renal transplant recipients (RTR) and 25 cases of chronic renal failure (CRF)
using engyme immunoassay (EIA). The results indicated that serum RRL, FSH and LH
level were reduced in RTR females compared with CRF, whereas E2 and P were
normal. Serum PRL levels were elevated in CRF females whereas P levels were
significantly lower compared with those of other groups. After clomiphene
stimulation test, the plasma levels of LH FSH and E2 elevated, suggesting
hypothalamic anovulation. Following successful renal transplantation, uremic
hypothalamic disfunction was ameliorated and normal menstrual cycle, fertility
was restored. During dialysis, treatment was given using suit therapy rather than
trigger the ovulatory. Renal transplantation is the best treatment.
PMID- 10678051
TI - [Surgical management of patients with infected vascular prostheses].
AB - We evaluated the therapeutic efficacy of surgical management of patients with
infected vascular prostheses. Eight cases of infected vascular prosthetic grafts
from 250 prosthetic bypasses were reviewed. The rate of graft infection was 3.2%.
Clinical manifestations were localized wound infection with prosthetic graft
exposure, anastomotic hemorrhage and gangrene in lower extremity. Treatment
included graft removal and debridement; graft removal and primary amputation;
graft removal and revascularization; debridement and local graft irrigation. Two
cases died from anastomotic hemorrhage and the others recovered. The predisposing
factors of vascular prosthetic infection are diabetes mellitus, secondary
hemotoma and reoperation in the same position. Conservative treatment efforts
without revascularization justifies a more aggressive approach to suspected graft
infection.
PMID- 10678052
TI - [Diagnosis and treatment of congenital choledochal cysts in adults].
AB - We report the experience with 97 adult patients with bile duct cysts in the past
30 years (1965-1995). The median age at time of initial therapy in our department
was 37 years (range, 16 to 78 years). Clinical symptoms in most cases were non
specific, resulting in delayed diagnosis. 74 patients (76%) had coexistent
pancreaticohepatobiliary disease. Carcinoma of the biliary duct occurred in 16
patients (17%). Abnormal pancreatobiliary duct junction (APBDJ) was found in 28
patients. 94 patients underwent a total of 169 biliarytract procedures. Cyst
excision with Roux-en-y hepaticojejunostomy and internal drainage were the main
procedures. The result of long-term follow-up shows that internal drainage
frequently resulted in recurrent cholangitis and cyst malignancy which need
reoperation. In contrast, cyst excision was associated with a significantly lower
incidence of recurred cholangitis and lower occurrence of malignancy. Thus, cyst
excision with Roux-en-y hepaticojejunostomy is recommended as the treatment of
choice for adult patient.
PMID- 10678053
TI - [Clinical application of transmyocardial laser revascularization].
AB - Transmyocardial laser revascularization (TMLR), a new technique, provides direct
perfusion of ischemic myocardium via laser-created transmural channels. From 1995
to 1996, we treated 7 patients (mean age 60 years, all men) with TMLR.
Preperatively, 5 patients were in angina class (C. C. S) 3-4 and 2 patients had
unstable angina. To identify the location and extent of their reversible
ischemia, the coronary angiogram, 99mSPECT and/or dobutamine echocardiography was
performed before operation in 7 patients. Through a left anterior thoractomy in
the fifth intehcostal space, heart exposure was gained. With the use of a 700
watt CO2 laser, TMLR was performed on the beating heart. An average of 22 +/- 3
channels were created in 45 minutes with a total operative time of less than 2
and half hours. The in hospital mortality was one of 7 patients. Follow-up ranged
from 2 to 12 months (accumulated 48 patient-months). Postoperatively, the relief
of angina was noted in 6 patients. Postoperative SPECT and dubatamin-UCG were
obtained at 3, 6, and 12 months. (99mTc) SPECT showed a significant improvement
of myocardial perfusion in the area of reversible ischemia. Dobutamin-UCG
documented an increase in the ventricular wall motion and LVEF in 2 patients as
compared with basline. These early results indicate that TMLR may provide angina
relief, improve myocardial perfusion and increase cardiac function for patients
with ischemic heart disease.
PMID- 10678054
TI - [Experience and lessons of lung transplantation].
AB - In the last 2 years, four hospitals performmed cooperatively single-lung
transplantation for 3 patients, 1 left lung and 2 right lung. The patients had
pulmonary fibrosis, COPD with cancer or tuberculosis, infection in some extent
before transplantation. The patients died from severe infection 9, 48 and 43 days
after the operation. We discussed the selection of donors and recipients,
operative procedures, postoperative management, especially monitoring,
differential diagnosis and treatment of infection and rejection. HLA
compatibility and transbronchial lung biopsy were important to the success of
lung transplantation. We believe that rejection and infection are important
causes of short-term death that should be given more attention.
PMID- 10678055
TI - [24 hour esophageal pH monitoring in patients with cardiac cancer
postoperatively].
AB - Twenty-four-hour esophageal pH monitoring was performed in thirty patients with
cardiac cancer on the 13rd to 18th postoperative day in order to understand the
condition of gastroesophageal reflux (GER), the value of commonly used operative
procedures and the effect of patients sleeping position for preventing GER. GER
parameters were higher than those of normal subjects (P < 0.001), but there were
only 60% patients who had typical GER symptoms. No significant differences were
found between anastomoses in abdomen and chest, encasing-in style, and "scarf"
style (P > 0.05). Patients sleeping with upper body raised for 30 degrees had
much lower GER parameters than those of controls. Manual anastomosis often used
now couldn't decrease GER. All patients with cardiac cancer have postoperative
GER though they had no typical symptoms of GER, but GER was avoided during
sleeping with upper body erected.
PMID- 10678056
TI - [Traumatic ascending ischemic injury of the spinal cord].
AB - We report five cases that the paraplegic level showed ascending from the segment
of spinal injury upward to the higher level. In T10-11 fracture-dislocation, the
paraplegic level ascended gradually to C2-3 in case 1 within 10 days and death
due to breathing paralysis. In case 2, the paraplegic level ascended to cervical
cord with loss of strength in both arms within 14 days. The remaining 3 cases
were Ti2(in 2 cases) and L3(1 case) fracture. Their paraplegic level ascended to
T8(2 cases) and T9(1 case). There were lower motor neuron paralysis in all cases.
Observation on spinal cord specimen of case 1 showed thrombosis of dorsal vessels
at T9-10 segment and multiple thrombosis were found in anterior spinal vessels,
central spinal vessels and intramedullar small vessels upward to C3 and downward
to S1 segments. The whole cord underwent ischemic necrosis.
PMID- 10678057
TI - [The vascular basis of pedicled adrenal transposition and its usage in the
treatment of Cushing's disease].
AB - To treat Cushing's disease, we studied the length and exterior diameter of the
inferior phrenic and superior adrenal artery and vein, and the reflow of the
adrenal vein. The length and exterior diameter of those blood vessels were
divided and measured by veiner calipor. Six patients with Cushing's disease were
treated by pedicled adrenal transposition to the musculus of the back. The right
inferior phrenic artery was 75-110 mm from the exterior edge of the vena cava to
the distant branch of the superior adrenal artery, while the left inferior
phrenic artery was 70-90 mm from the left edge of the aorta to the distant branch
of the superior adrenal artery, both of which have veins to accompany them. The
superior adrenal artery came from the inferior phrenic artery relatively common
and was divided into six branches. The exterior diameter of the distal superior
adrenal artery was 1.5-2.5 mm and could be freed for 40-80 mm. Lateral veins
could complete the adrenal blood drainage after the left central adrenal vein was
ligated. The transpositioned blood vessel pedicle consisted of the distant
inferior phrenic artery and vein, the distant branches of the superior adrenal
artery and vein. The patient who had received the transposition treatment had
neither hypocortisolism nor recurrence after 4 to 35 months. The length of the
inferior phrenic, superior adrenal gland vessels could content the remained
adrenal gland to reach their transposition bed when freed. The pedicled adrenal
transposition to the musculi is an ideal method in the treatment of Cushing's
disease.
PMID- 10678058
TI - [Experimental study on the effect of extremities ischemia reperfusion inducing
anterior tibial compartment pressure].
AB - We observed the changes of compartment pressure after extremities were reperfused
at different intervals of ischemia and its relationship with the changes of serum
MDA and CPK content. The protective effect of mannite on extremities ischemia
reperfusion was also studied. 18 New Zealand rabbits were separated into three
groups: group A (ischemia 4 h); group B (ischemia 8 h); group C (ischemia 4 h).
The rabbits of group A and B were intravenous injected with normal saline (NS),
and group C was injected with 20% mannite. The changes of compartment pressure of
serum MDA and CPK content and the histological changes of skeletal muscles in
every group were noted at different times: preoperation; the beginning of
ischemia; the end of ischemia and reperfusion for 4 h; 24 h; 72 h, respectively.
The longer ischmia lasted, the more serious the tissue damage was. Reperfusion
made tissue damaged further. After reperfusion for 24 h, the damage was the most
serious. Meanwhile, the serum MDA and CPK content also reached the peak value.
These changes were in accord with those of compartment pressure. On the other
hand, the damage of mannite group was relatively mild. Extremity ischemia
reperfusion would led to the increase of compartment pressure, then intensified
the damage. The damage was the most serious at 24 h of reperfusion. Using mannite
could reduce the tissue damage and compartment pressure. Mannite should be
recommended as the first-selected drug for extremity ischemia reperfusion injury.
PMID- 10678059
TI - [Lumbar intervertebral disc injuries].
PMID- 10678060
TI - [Prevention and treatment of joint prosthesis complications].
PMID- 10678061
TI - [Severe vascular injuries following total hip replacement].
AB - Severe vascular injury following total hip replacement (THR) is very rare. It has
an a incidence of 0.25% and poses a serious threat to the involved limb and the
patient's life. Vascular structures affected include the external iliac artery
and vein, femoral artery and vein. In 721 cases of THR 3 had vascular injuries.
The first case sustained the injury of the external iliac vessel which was cut by
the sharp edge of bone cement while removing the displaced prosthesis. The second
had laceration of the iliac vein while a pneumatic drill was used in the anterion
superior acetabulum, and the third had the cut injury of the femoral artery
during resection of the capsular scar tissue. The understanding of the mechanisms
and location of vascular injury during THR will help surgeons in early diagnosis
and treatment of the injury.
PMID- 10678062
TI - [One-stage reimplantation for the salvage of total knee arthroplasty complicated
by infection].
AB - One-stage reimplantation for the salvage of infected total knee arthroplasty in 8
patients was reviewed at an average follow-up of 20.1 months late infections
occurred in 7 (87.5%) patients. The timing of the diagnosis of the infection
after knee arthroplasty was of the prosthesis averaged 11.5 months. No one had
recurrent infection and pain was relieved significantly in all patients. Our
results suggest that one-stage reimplantation is a reasonably reliable procedure
for the management of an infected prosthesis. The use of Gentamicin-impregnated
bone cement and the Streptomicin bead mixed with Gentamicin improve the success
of treating or preventing recurrence of the infection. Early one-stage
reimplantation was needed as soon as the deep infection was defined in order to
decrease more destruction of the bone.
PMID- 10678063
TI - [Polyethylene wear in periprosthetic tissue of failed cemented total hip
arthroplasties].
AB - To elucidate the relationship between polyethylene wear and loosening of total
hip arthroplasty, we observed grossly the periprosthetic tissues, polyethylene
wear debris and polyethylene acetabular liners retrieved from 6 failed cemented
total hip arthroplasties during revisions by means of polar light miscroscope and
scanning electron microscope. The production mechanism of polyethylene wear
debris from acetabular liner was analyzed together with its role in
periprosthetic fibrosis and prosthetic loosening. Results showed the abrasion of
two bearing surfaces interposed with third-body particles as called three-body
abrasion was the main model of polyethylene wear. All inner surfaces of the
liners appeared clear abrasive scratches and big flat debris were found in most
of the retrieved tissues. Histologically, the wear debris of various sizes
embraced by 1 or several polynuclear giant cells that were found not only great
in number but also active in function. The implication is that three body
abrasion is the key factor of high rate wear of the polyethylene liner and that
polynuclear giant cell is acting as an important cellular component leading to
the prosthetic loosening.
PMID- 10678064
TI - [Total knee replacement in diabetic patients].
AB - From December 1987 to March 1995, 16 TKRs were performed for 9 diabetic patients
at our department. 7 of them had rheumatoid arthritis (RA), and 2 osteoarthritis
(OA). There were 1 male and 8 females. The average age was 55.9 years (range 49
69 years), and the average weight was 64.5 kg (range 54-78 kg). According to the
hospital for special surgery (HSS) knee rating scale, the pre and postoperative
evaluations were made. The HSS scores were improved after the operation from
average 30.2 points preoperatively to 78.2 points postoperatively. The excellent
and good rate was 94%. After 3.9 years follow-up (range 10 months to 8 years),
the HSS score was 74.4 points, and the rate of excellent and good was 87.5%.
Compared to the other 209 RA or OA patients with 287 TKR at the same period, the
HSS score was almost the same, but the infection rate was higher (3.5%). We
conclude that the TKR of diabetic patients could also get the similar results as
common patients if the patients are under the good control of glycemia and
medical treatment.
PMID- 10678065
TI - [Sonographic measures of the hip joint of 1328 newborns of Han and Uygur
nationalities-relative factors of congenital dislocation of hip].
AB - The four sonographic methods (Engesaeter, Terjesen, Graf, Morin-Harcke) were used
for examining the hip joint of 1328 newborns of Han and Uygur nationalities. The
difference between Han and Uygur newborns was not statistical significant, but
some literatures reported that in our country, the incidence of different
nationalities in different regions varied. Our conclusion is that there is no
obvious relationship between the depth of the acetabulum and the percentage of
the femoral head covered by the acetabulum. It is caused by other factors,
inherent or acquired. The value of the hip joint of the male and female has
significant difference (P < 0.0005). The incidence of CDH in girls is much higher
than that in boys. This may be related to the different depth of the acetabulum
and different percentage of the femoral head covered by the acetabulum. In the
period of newborn, girl's depth of the acetabulum is smaller than that of boys.
PMID- 10678066
TI - [Effects of peripheral biofilm infection of artificial prosthesis on bacteria].
PMID- 10678067
TI - [Posterior cruciate ligament injuries].
PMID- 10678068
TI - [Prognosis prediction of S-phase fraction and p53, c-erbB-2, estrogen receptor,
progesterone receptor in axillary node-negative breast cancer].
AB - The prognostic factors in 180 axillary node-negative breast cancer patients with
more than 5 year follow-up were searched for with multiple regression. Based on
the regression results, the cases with treatment failure in 5 year and the cases
with 5 year disease free survival were matched at 1:2 ratio. Then the c-erbB-2
protein, p53 Protein, estrogen receptor (ER), progesterone receptor (PR) and the
S-phase fraction (SPF) were measured in paraffin-embedded breast cancer tissue.
The results were analysed with log-rank test and Cox-Model. Among the
biobehaviour factors measured, the SPF was the strongest prognosis predictor for
ANN. The 5 year disease free survival rate of ANN with SPF < 10% or > 10% was 94%
and 52% respectively (P < 0.001). The treatment failure relative risk of patients
with SPF > 10% ANN was 11.31. The relative risk of other four factors was
respectively, PR 3.58 (P < 0.002), ER 2.93 (P < 0.05), p53 1.44 (P > 0.3), c-erbB
2 1.38 (P > 0.5). The combination of PR or EP with SPF could make the relative
risk even higher.
PMID- 10678069
TI - [Application of preoperative angiography in diagnosis of gastric cancer].
AB - To improve preoperative diagnosis of gastric cancer, we applied DSA in clinical
diagnosis. 36 patients with gastric cancer were observed. Preoperative DSA and
postoperative pathological analysis revealed the following results. With DSA, the
accuracy of diagnosis of invasion depth of gastric cancer reached 72.2%. We
summarised the criteria for diagnosis of gastric cancer. If subsidiary
anastomotic channels narrow or obliterate in DSA, the case may be early cancer.
If parietal branches narrow or obliterate in DSA, the cancer may invade the
muscle of the stomach. If arcade of this lesser curvature narrows in DSA, the
cancer may invade the serosa of the stomach. If the roots of main vascular
vessels, such as the left gastric artery, and vascular vessels of other organs
narrow or obliterate in DSA, the cancer may directly invade other organs as well.
Two-thirds of gastric cancer could be identified through DSA with their shapes
and characteristics. The varied shapes of vascular vessels caused by invasion of
gastric cancer could reveal growing mode of the cancer.
PMID- 10678070
TI - [Extra-anatomical bypass for subclavian artery occlusion].
AB - 20 patients with subclavian artery occlusion were treated by extra-anatomical
bypass from 1989 to 1996. There were 9 men and 11 women, aged from 20 to 63 years
with a duration of 1 month to 18 years. The main causes of illness were
Takayasu's arteritis and atherosclerosis. Symptoms of upper extremity ischemia
were present in 17 patients and vertebrobasilar insufficiency in 11. Carotid
subclavian/axillary bypass and axilloaxillary bypass were performed on 17 and 3
patients respectively. There were no operative deaths. Relief of symptomes was
achieved in all the patients except one who had reocclusion of bypass graft due
to rather poor outflow vessel. We stressed the surgiacal technique of extra
anatomical bypass in the treatment of subclavian artery occlusion. With few
postoperative complications and high patency rate, we consider extra-anatomical
bypass a safe, simple, well-tolerated and durable procedure for the treatment of
subclavian artery occlusive disease in high-risk patients.
PMID- 10678071
TI - [Treatment of malignant or aggressive bone tumors with microwave induced
hyperthermia].
AB - Limb-sparing procedures have been well established for dealing with malignant
bone tumors. Unfortunately, these procedures have different problems. We used an
alternative operation combined with microwave-induced hyperthemia to modify the
surgical methods. Thermotherapy with microwave intracorporeal irradiation was
used to treat 112 patients with bone tumors. In this series, 79 had malignant
tumors and 33 aggressive benigh tumors. Postoperatively, immune therapy was
carried out regularly. The patients immunologic functions were monitored by assay
of the subpopulation of T cells, IL-2 and sIL-2R (soluble IL-2 receptor). Follow
up varied from 3 to 50 months (mean 23 month) s. Excluding 5 patients with
malignancy in the vertebrae treated for palliation, 107 were evaluated by
oncological and orthopedic criteria. 10 patients had local recurrence and
required amputation. The remaining 97 had excellent local control. In 12 of the
74 patients with malignancy of the extremities, lung metastasis occurred 4 months
to 2 years after surgery. Pathological fracture occurred at devitalized bone in 8
patients. In 29 out of 40 tumor-free cases followed for more than 2 years, the
knee joints functioned properly with almost full range of motion. Single photon
emission computered tomography (SPECT) study revealed revascularization of the
devitalized tumor bearing bone segment could accomplish in one year or more. The
immune state was improved after thermotherapy plus immunotherapy in the majority
of patients. These results indicated that the use of microwave hyperthermia and
adjuvant immunotherapy in the surgical treatment of bone tumors can be considered
a definitive procedure, which is safe and well-tolerated.
PMID- 10678072
TI - [Tracheobronchoplasty: a report of 40 cases].
AB - Tracheo bronchoplastic surgery with or without simultaneous arterioplasty was
porformed in 40 cases of various bronchopulmanary diseases (benign in 8 and
malignant 32). The operation consisted of reconstruction of trachea in 3 cases,
plastic carinoplasty 2 cases, and bronchoplasty and pulmonary arterioplasty 1
case, sleeve resection of bronchus 34 cases, 4 cases (10%) had postoperative
complications. Two cases (5%) died shortly after operation. Thirty-eight cases
recovered. Thirty cases of malignant tumor were followed up from 1 to 10 years.
The survival rates were 83.3% (25/30), 53.3% (16/30), 40% (12/30), 23.3% (7/30)
at 1, 3, 5 and 10 years respectively. We discussed indication, anesthetic
management, surgical procedure and results. The indication must be controlled
strictly. The operative procedure and postoperative management must be further
improved because the complications and mortality of tracheobronchoplasty are
higher than those of conventional resections.
PMID- 10678073
TI - [Surgical treatment of non-thoracotraumatic pneumomediastinum].
AB - The experience of surgical treatment of non-thoracotraumatic pneumomediastinum in
48 cases was summarized. The etiology, classification, pathology, and surgical
treatment of non-thoracotraumatic pneumomediastinum were discussed. We conclude
that most non-thoracotraumatic pneumomediastinum was complicated by secondary
diseases. Therefore, the effective treatments for primary diseases are important.
A satisfactory effect must be based on different surgical techniques according to
the different clinical symptoms and age of patients.
PMID- 10678074
TI - [Diagnosis and surgical management of 22 patients with congenital coronary artery
fistula].
AB - Twenty-two patients underwent surgical treatment of coronary artery fistulas. The
right coronary artery was the most common vessel of origin (68.2%), and the most
frequent drainage site was the right ventricle (45.4%). The operation was
performed with the use of extracorporeal circulation in 21 patients. Only one
patient underwent distal ligation without the use of extracorporeal circulation.
The absence of operative mortality and severe postoperative complication provide
clear indications for surgical treatment. In view of currently improved and
standardized techniques of extracorporeal circulation, we believe that it should
be employed routinely.
PMID- 10678075
TI - [Simultaneous coronary artery bypass grafting with other cardiovascular surgical
procedures].
AB - To improve the effect and reduce the mortality of the simultaneous coronary
artery bypass grafting (CABG) with other cardiovascular surgical procedures, from
Nov, 1984 to July, 1996, 51 patients underwent such operation. Among them 45
patients had valvular heart diseases, 4 postinfarction ventricular septal defect
and ventricular aneurysm, and 1 myxoma of left atrium and abdominal aortal
aneurysm. The operative mortality was 5.85% (3/51), and 3 patients died.
Cardiovascular surgical patients of over 50 years or with angina pectorsi and ECG
confirmed myocardiac ischemia should undergo coronary angiography routinely. If
main coronary artery branches stenosis occupied over 50%, CABG must be performed.
During the operation revasculariztion should be made as full as possible to
enhance myocardiac protection and reduce the ascending aortic cross-clamping
time.
PMID- 10678076
TI - [Isolation of human herpes virus 6 from peripheral blood of renal transplant
recipients].
AB - One strain of the viruses was isolated from preipheral blood lymphocytes (PBL) of
a renal transplant recipient. PBL isolated from blood samples were cocultured
with the PHA actived cord blood lymphocytes (CBL). Two of twelve recipient's
samples found cytopathic effect after 10 to 14 days. Examination of ultrathin
sections of the virus infected cells by electron microscope showed herpes-like
virus particles. Detection of indirect immunofluorescences with McAbs against HHV
6 was positive in the infected cells.
PMID- 10678077
TI - [Diagnosis and treatment of postrenal acute renal failure].
AB - 52 cases of postrenal acute renal failure (ARF) from 1985 to 1995 were studied.
50 cases underwent emergency operation, and 2 were drained with ureter intubation
by cystoscope. 37 cases (71.2%) were cured, 14 (26.9%) were improved, and 1
(1.9%) died. Oliguria, anuria and progressive increase of blood urea nitrogen and
serum creatinine are the main points of diagnosis. Renal percussive pain is the
important sign. B-ultrasonography examination is the first choice and often
indicate the increase of the volume of kidney and mild hydronephrosis.
Obstruction should be removed as quickly as possible, infection should be
prevented and treated to protect renal function. The way of treatment should be
adopted according to the variant causes and conditions of disease. The etiology,
clinical findings, diagnosis, operating methods and cautions were discussed.
PMID- 10678078
TI - [The role of PMN CD11b/CD18 on the increasing PMN adhesion to endothelial cells
induced by severe burn injury].
AB - The process of leukocyte adhesion was mediated by the intercellular adhesion
molecular. In this study, both the influence of burn serum on the expression of
PMN CD11b/CD18 and the role of CD11b/CD18 on the burn serum stimulated PMN
adhesion to endothelial cells (EC) were investigated. The expression of
CD11b/CD18 on PMN incubated with burn serum for 2 hours was increased obviously.
So was PMN adhesion to EC. Monoclone antibody to PMN CD11b/CD18 could reduce the
normal PMN adhesion to EC by half and block the increasing PMN adhesion induced
by burn serum. These indicated that PMN CD11b/CD18 may be the main adhesion
molecular participating in the increasing PMN adhesion to EC due to severe burn.
PMID- 10678079
TI - [Preparation and clinical application of blocking glue for cancerous serosa].
AB - The blocking glue of cancerous serosa (F-TH glue) is unharmful to human body. It
has characteristics of shorter solidification time to become membrane, good
elasticity and close adherence to tissue, mainly used for covering cancerous
serosa in operation to prevent dropping of cancer cells. In this group, F-TH glue
was used in 200 cases of gastrointestinal cancer, in which 75 had positive
results of imprinting slice of cancerous serosa, and all became negative. It was
confirmed that the glue adhered to cancerous serosa firmly and formed intact
protective membrane. No rhagades and dropping of glue were seem by naked eye
magnifying glass and electron microscope. The membrane of glue forbid cancer
cells not penetrated. It was an excellent glue to block the cancerous serosa.
PMID- 10678080
TI - [Treatment of liver or renal cyst by percutaneous injection of TH glue into the
cyst cavities].
AB - From April 1995 to May 1996, 32 cases of liver or renal cyts were detected by B
ultra sound. Among them, TH glue was injected into the cyst to make it coagulated
and occluded in 4 cases of liver cyst and 8 cases of renal cyst after
intracapsular fluid was abstracted. The curative effect was good. The curative
rate of single injection was 83.3%. The period of treatment and the curative rate
were obviously different from the past methods. The present method is easy,
quick, small wounded, few complicated and no toxic and side effects.
PMID- 10678081
TI - Dynamic digital fluorescence ratio imaging of cell calcium in vascular
endothelial cells.
AB - AIM: To study the spatial and temporal distribution of intracellular Ca2+
concentration in cultured bovine pulmonary artery endothelial (BPAE) cells.
METHODS: Cultured BPAE cells were loaded with Fura-2 and observed under an
inverted microscope coupled to a microfluorimeter, which enables pixel-to-pixel
ratio imaging of the BPAE cells in real time. RESULTS: Addition of Ca2+ 1-2
mmol.L-1 to BPAE cells, which were exposed to Ca(2+)-free medium containing
egtazic acid, resulted in a transient elevation of cytosolic Ca2+ concentration,
which rapidly returned to the resting level. Biphasic elevation (a larger
transient phase followed by a smaller sustained phase) of intracellular Ca2+
concentration was observed upon the addition of ATP (via activation of surface
membrane receptor). 4-Chloro-3-ethyl phenol (CEP; an activator of Ca(2+)-induced
Ca2+ channels) potently induced elevation of Ca2+ level. Cyclopiazonic acid (CPA;
an inhibitor of endoplasmic reticulum Ca(2+)-ATPase pump) offered a more
sustained elevation of Ca2+. In most cases, the highest level of Ca2+ elevation
was observed around the cell peripheries, sometimes at rest and particularly upon
stimulation. Ca2+ elevation associated with nuclear complex seemed to be higher
compared to that in the cytosolic compartment. CONCLUSION: Changes of cell Ca2+
upon stimulation by various agents that acted at different intracellular sites
were found to be temporarily and spatially heterogenous among BPAE cells. At the
single cell level, Ca2+ elevation seemed to occur initially near the peripheral
region followed by the nuclear region. This study raised the possibility that
nuclear Ca2+ and cytosolic Ca2+ might be regulated independently in BPAE cells.
PMID- 10678082
TI - 6,7-dimethoxycoumarin attenuated cisplatin-induced DNA interstrand crosslink and
DNA-protein crosslink in primary cultured rabbit kidney proximal tubular cells.
AB - AIM: To study the mechanism of cisplatin interaction with DNA, and the
attenuating effects of 6,7-dimethoxycoumarin (DMOC) on crosslink. METHODS:
Primary cultured rabbit kidney proximal tubular cells (PTC) were established. DNA
interstrand crosslink was assayed with ethidium bromide binding and DNA-protein
crosslink with 125I-postlabelling. PTC were incubated with cisplatin for 24 h.
DMOC was preincubated with PTC for 24 h, and cisplatin (26 mumol.L-1) was added
into culture and incubated for another 24 h. RESULTS: Cisplatin induced formation
of DNA interstrand crosslink (13, 26, 52, and 78 mumol.L-1) and DNA-protein
crosslink (26, 52, and 78 mumol.L-1) (P < 0.01). DNA interstrand crosslink in
DMOC (0.4, 4, and 8 mg.L-1) and DNA-protein crosslink in DMOC (4, 8 mg.L-1) were
less than those in cisplatin group (26 mumol.L-1), respectively (P < 0.01).
CONCLUSION: The mechanisms of cisplatin interaction with DNA in PTC were DNA
interstrand crosslink and DNA-protein crosslink, and DMOC attenuated these
effects in vitro.
PMID- 10678083
TI - Cytosolic-Ca2+ and coxsackievirus B3-induced apoptosis in cultured cardiomyocytes
of rats.
AB - AIM: To explore the role of cytosolic free calcium ([Ca2+]i) in apoptosis induced
by coxsackievirus B3 (CVB3) in cultured cardiomyocytes of rats. METHODS: Primary
cultured cardiomyocyte was prepared from Wistar rats ages 2-3 d. The apoptosis in
cardiomyocyte was determined by terminated deoxynucleotide transferase directed d
UTP nick and end labeling (TUNEL) method, and the apoptosis was observed under a
transmission electron microscope. [Ca2+]i in single cardiomyocyte loaded with
Fluo 3-AM was measured by confocal microsorope. RESULTS: (1) The concentration of
CVB3 in the medium reached the peak at 24 h after CVB3 infection. (2) The
apoptotic cells were not found in CVB3-infected cardiomyocyte in first 10 h, but
amounted to 5% at 17 h, 60% at 24 h, and 90% at 36 h. (3) The peak value of
[Ca2+]i elevation reached at 17 h after CVB3 infection (P < 0.01). (4) The
characteristics of apoptosis was also seen by transmission electron microscope.
CONCLUSION: CVB3 induced the apoptosis in cultured cardiomyocyte, and [Ca2+]i
mobilization was involved in the signal transduction process in apoptosis cells,
and played an important role especially in the early stage of apoptosis induced
by CVB3.
PMID- 10678084
TI - Effects of anordrin, droloxifene, nomegestrol, and mifepristone on cultured rat
luteal cell apoptosis.
AB - AIM: To study the effect of four kinds of antifertility agents anordrin(Ano),
droloxifene(Dro), nomegestrol (Nom), and mifepristone (Mif) on luteal cell
apoptosis. METHODS: Cultured rat luteal cells were incubated with different
agents. HE stain was used to observe morphological changes. Extracted DNA was
electrophoresed on agarose gel. Apoptotic cells were quantitated by flow
cytometry. RESULTS: All 4 drugs reduced cell viability. Dro induced apoptosis
while the other 3 drugs induced necrosis. Typical DNA ladders were observed after
cells were incubated with Dro and there were 15.4%, 75.4%, or 90.5% apoptotic
cells after treatment with Dro 1.25, 2.5, or 3.75 mg.L-1, respectively.
CONCLUSION: Dro induced apoptosis while Ano, Nom, and Mif induced necrosis in
cultured rat luteal cells.
PMID- 10678085
TI - Systemic anti-inflammation by synthetic interleukin-1 blockers.
AB - AIM: To study the systemic anti-inflammatory actions of interleukin-1 (IL-1)
blockers, OB-101 and OB-186. METHODS: Prevention of palm swelling induced by
carrageenin injection was used as an animal model of systemic anti-inflammation
efficacy. RESULTS: Both OB-101 and OB-186 (10-30 mg.kg-1) were approximately 10
30-fold more potent than aspirin (300 mg.kg-1) to inhibit carrageenin-induced
systemic inflammation. The LD50 of OB-101 and OB-186 were at least 20 g.kg-1
i.g., indicating that they were extremely safe agents with a therapeutic index
(LD50/ED50) of at least 2000. CONCLUSION: These IL-1 blockers are extremely safe
systemically and are useable for the treatment of systemic inflammation such as
rheumatoid arthritis.
PMID- 10678086
TI - Protective effect of melatonin on injuried cerebral neurons is associated with
bcl-2 protein over-expression.
AB - AIM: To study the protective effect of melatonin against neuronal injury and the
possible roles of alteration in the expression of bcl-2 and bax following brain
ischemia. METHODS: Brain ischemia was induced by left middle cerebral artery
occlusion (MCAO) for 60 min in rats. Brain damage was evaluated by the infarct
area and the neuronal cell counting. The expression of bcl-2 and bax was analyzed
by immunohistochemical method. RESULTS: Melatonin decreased the infarct area and
prevented the neuronal death after 24-h reperfusion following 1-h MCAO. Melatonin
given before the ischemia enhanced the expression of bcl-2 in the penumbra area
and had no significant effect on the expression of bax. CONCLUSION: Melatonin
effectively attenuated ischemic brain injury and increased the expression of
neuronal bcl-2 in the ischemic brain, indicating that the protective effect of
melatonin was associated with up-regulation of bcl-2 in ischemia-induced neuronal
death.
PMID- 10678087
TI - Effects of calcium channel blockers on calcium release-activated calcium currents
in rat hepatocytes.
AB - AIM: To study the influences of calcium channel blockers on calcium release
activated calcium currents (ICRAC) in rat hepatocytes. METHODS: Whole-cell patch
clamp technique was used. RESULTS: The peak amplitude of ICRAC was -0.41 nA +/-
0.09 nA (n = 15), its reversal potential was about 0 mV. Verapamil (Ver),
diltiazem (Dil), and nifedipine (Nif) decreased ICRAC strikingly, without
affecting its reversal potential. The inhibitory rate of Ver 5 mumol.L-1 was 40%
+/- 12% (n = 3), Ver 50 mumol.L-1 reduced the peak amplitude of ICRAC from -0.49
nA +/- 0.12 nA to -0.20 nA +/- 0.09 nA (P < 0.01 vs control, n = 5). The
inhibitory rate was 57% +/- 15%. Dil 50 mumol.L-1 and Nif reduced ICRAC from
0.43 nA +/- 0.10 nA to -0.29 nA +/- 0.07 nA (P < 0.01 vs control, n = 5), from
0.32 nA +/- 0.08 nA to -0.27 nA +/- 0.08 nA (P < 0.01 vs control, n = 5). The
inhibitory rate was 31% +/- 11%, 19% +/- 7%, respectively. The amplitude of ICRAC
was dependent on extracellular Ca2+ concentration. The peak amplitude of ICRAC
was -0.21 nA +/- 0.08 nA (n = 3) in Tyrode's solution with Ca2+ 1.8 mmol.L-1 (P <
0.01 vs the peak amplitude of ICRAC in external solution with Ca2+ 10 mmol.L-1).
CONCLUSION: The three calcium antagonists inhibited ICRAC effectively and
protected hepatocytes from calcium overload via the inhibition of ICRAC.
PMID- 10678088
TI - Devazepide reversed effect of sincalide against morphine on rat jejunal
activities.
AB - AIM: To study the antagonism of sincalide to the effect of morphine and its
mechanism. METHODS: The electrophysiologic and mechanic activities of rat jejunum
in vitro were recorded. RESULTS: Acetylcholine (ACh, 150 nmol.L-1) increased the
spike potential amplitude (SPA) and the number (SPN) of rat jejunum in vitro,
followed by an increase of jejunal contraction amplitudes (CA), showing a
positive correlation. Morphine 330 nmol.L-1 inhibited the potentiation of ACh,
showing a negative correlation. Sincalide 0.7 nmol.L-1 antagonized the effects of
morphine, i.e., the SPA and SPN were increased again, followed by an increase of
CA. CCK-A receptor antagonist devazepide (10 nmol.L-1) reversed the antagonism of
sincalide to the effect of morphine. CONCLUSION: Sincalide antagonized the effect
of morphine which inhibited the potentiation of ACh on jejunal activities in
vitro. The antagonistic effect of sincalide on morphine was mainly mediated by
CCK-A receptor.
PMID- 10678090
TI - Quercetin decreased heart rate and cardiomyocyte Ca2+ oscillation frequency in
rats and prevented cardiac hypertrophy in mice.
AB - AIM: To study the effects of quercetin (Que) on myocardial excitation-contraction
coupling and cardiac remodeling. METHODS: Left ventricles and femoral arteries of
rats were cannulated for hemodynamic recording. Mouse cardiac hypertrophy was
induced by abdominal aortic coarctation (AAC). Cultured myocardial cells in
neonatal rats were loaded with Fura 2-AM. The intracellular calcium ([Ca2+]i) and
spontaneous [Ca2+]i oscillations ([Ca2+]i-SO) were tested by AR-CM-MIC cation
measurement system. RESULTS: Que 3 or 25 mg.kg-1 i.v. in rats decreased heart
rate from (420 +/- 19) to (390 +/- 15) and (314 +/- 18) beat.min-1, respectively,
companied with very modest changes in both left ventricular pressures (LVP) and
its differential dpLV/dtmax. Que 10, 50, 250 mumol.L-1 concentration-dependently
slowed the frequency of [Ca2+]i-SO in cultured myocardial cells from (26 +/- 4)
to (25 +/- 3), (18 +/- 4), and (12 +/- 3) time.min-1, respectively, but did not
change their resting [Ca2+]i or amplitudes of [Ca2+]i-SO. Similarly, the
increases in frequency of [Ca2+]i-SO caused by either isoproterenol (Iso) or
ouabain (Oua) were prevented by Que 100 mumol.L-1, while the simultaneous
increases in amplitude of [Ca2+]i-SO remained. Besides, [Ca2+]i rises excited by
angiotensin II (Ang II) but not high [K+]o were prevented by Que 100 mumol.L-1.
Daily administration of Que 120 mg.kg-1 i.g. for 5 d markedly prevented the
cardiac hypertrophy in AAC mice, without effects on the ventricular mass to body
weight ratio (VM/BW) in sham-operated mice. CONCLUSION: Que decreased myocardial
[Ca2+]i-oscillation frequency and prevented cardiac remodeling, but had no direct
effect on cardiac excitation-contraction coupling.
PMID- 10678089
TI - Antagonistic effects of Ginkgo biloba extract on adhesion of monocytes and
neutrophils to cultured cerebral microvascular endothelial cells.
AB - AIM: To study the action of Ginkgo biloba extract (GbE) on tumor necrosis factor
(TNF-alpha)-induced adhesion of monocytes (Mon) and neutrophils (Neu) to cultured
cerebral microvascular endothelial cells. METHODS: TNF-alpha-induced endothelial
adhesivity toward Mon and Neu was studied using bovine cerebral microvascular
endothelial cells (BCMEC) in vitro. The number of Mon and Neu adhering to the
BCMEC monolayers was determined by flow cytometry. RESULTS: Pretreatment of BCMEC
with TNF-alpha increased Mon and Neu adhesion to BCMEC from 12.5% +/- 0.2% to
31.3% +/- 0.5% and from 13.8% +/- 0.4% to 32.1% +/- 0.5%, respectively. GbE (1
100 mg.L-1) inhibited the effect of TNF-alpha in a concentration-dependent
manner. E-selectin mAb (1 mg.L-1) blocked Mon and Neu adhesion to BCMEC induced
by TNF-alpha. CONCLUSION: The inhibition of GbE on Mon and Neu adhesion to BCMEC
was mediated through the suppression of E-selection expression.
PMID- 10678091
TI - Selective effects of alfuzosin and doxazosin with intraduodenal administration on
urethral pressure of cats.
AB - AIM: To observe the selective effects of alfuzosin (Alf) and doxazosin (Dox) on
the urethral pressure by different administration routes. METHODS: The urethral
pressure of the anesthetized cat was increased by electric stimulation of the
hypogastric nerve. The different effects of Alf or Dox on the arterial blood
pressure and urethral pressure between intraduodenal administration (i.d.) and
intravenous infusion (i.v.) were compared. RESULTS: When the hypogastric nerve
was stimulated by electric stimulation (10 Hz, 25 V), the ratios of
ED20(BP)/ED50(UP) i.d. to ED20(BP)/ED50(UP) i.v. were 10.9:4.3 for Alf, and
3.1:2.1 for Dox. The reduction in urethral pressure induced by i.d. Alf was
greater than that by i.v. Alf. Dox did not show any difference in its effects by
2 administration routes. CONCLUSION: Intraduodenal administration of Alf, but not
Dox, selectively decreased the urethral pressure elevated by electric
stimulation. The uroselectivity of i.d. Alf was not due to the species difference
in its bioavailability and biotransformation.
PMID- 10678092
TI - Circumvention of tumor multidrug resistance by a new annonaceous acetogenin:
atemoyacin-B.
AB - AIM: To explore the effect of atemoyacin-B (Ate) on overcoming multidrug
resistance (MDR). METHODS: Bullatacin (Bul) was used as a positive control.
Cytotoxic effects of Bul and Ate were studied with cell culture of human MDR
breast adenocarcinoma cells, MCF-7/Dox and human KBv200 cells, and their parental
sensitive cell lines MCF-7 and KB. Cytotoxicity was determined by tetrazolium
(MTT) assay. The function of P-glycoprotein (P-gp) was examined by Fura 2-AM
assay. Cellular accumulation of doxorubicin (Dox) was determined by fluorescence
spectrophotometry. Apoptosis was measured by flow cytometry. RESULTS: IC50 of Ate
for MCF-7/Dox, MCF-7, KBv200, and KB cells were 122, 120, 1.34, and 1.27 nmol.L
1, respectively. IC50 of Bul for MCF-7/Dox, MCF-7, KBv200, and KB cells were
0.60, 0.59, 0.04, and 0.04 nmol.L-1, respectively. The cytotoxicities of Bul and
Ate to MDR cells were similar to those to parental sensitive cells. Bul and Ate
markedly increased cellular Fura-2 and Dox accumulation in MCF-7/Dox cells, but
not in MCF-7 cells. The rates of apoptosis in MDR cells were similar to those in
sensitive cells induced by Ate. CONCLUSION: There was no cross-resistance of P-gp
positive MCF-7/Dox and KBv200 cell lines to Bul and Ate as compared with their
sensitive P-gp negative MCF-7 and KB cell lines. The mechanism of the
circumvention of MDR was associated with the decrease of P-gp function and the
increase of cellular drug accumulation in MDR cells.
PMID- 10678093
TI - Gene therapy for human hepatocellular carcinoma with cytosine deaminase gene and
prodrug flucytosine.
AB - AIM: To investigate the antitumor effects of cytosine deaminase (CD) gene in
combination with prodrug flucytosine (Flu, 5-fluorocytosine) on human
hepatocellular carcinoma. METHODS: CD gene was transduced into human
hepatocellular carcinoma cell line SMMC7721 with retroviral method and the
cytotoxicity of Flu on the tumor cells was assayed in vitro with clonogenic
techniques. The xenograft tumor model in nude mice was used to study in vivo
therapeutic effects of CD gene/Flu system against human hepatocellular carcinoma.
RESULTS: CD gene/Flu system had significant antitumor activities on human
hepatocellular carcinoma cells in vitro and in nude mice. The antitumor
activities of Flu 500 mg.kg-1 on hepatocellular carcinoma xenografts in nude mice
were more potent than those of 5-fluouracil 10 mg.kg-1. CD gene/Flu system
possessed bystander killing effects on hepatocellular carcinoma xenografts in
nude mice. CONCLUSION: The experiment demonstrates the potential value of the CD
gene/Flu system in the treatment of human hepatocellular carcinoma.
PMID- 10678094
TI - Apoptosis and necrosis induced by sulfur mustard in Hela cells.
AB - AIM: To study the apoptotic effect of sulfur mustard (SM) on Hela cells. METHODS:
Exponentially growing Hela cells were treated with SM at various concentrations
for 3 h, then apoptosis was examined by electron-microscope, DNA gel
electrophoresis, and flow cytometry. RESULTS: SM 1 mumol.L-1 arrested cell
growth. After treatment with SM 10-100 mumol.L-1, cells were mainly blocked at G1
phase with apoptosis. Agarose gel electrophoresis of DNA from cells treated with
SM revealed "DNA Ladder." About 33% of the Hela cells showed apoptosis 12 h after
3-h treatment with SM 100 mumol.L-1 as determined by flow cytometry and the S
phase cells were more susceptible. However, SM 1000 mumol.L-1 caused marked
necrosis in Hela cells. CONCLUSION: SM caused 2 distinct forms of cell death,
apoptosis or necrosis, in Hela cells in a concentration-dependent manner.
PMID- 10678095
TI - Ro 31-8220 inhibits release of interleukin-1 and interleukin-6 from mouse
peritoneal macrophages induced by fibrin fibrinogen degradation products.
AB - AIM: To study the effect of fibrin fibrinogen degradation products (FFDP) on
release of interleukin-1 (IL-1) and interleukin-6 (IL-6) from mouse peritoneal
macrophages, and the effect of a new selectively potent protein kinase C
inhibitor Ro 31-8220 (Ro). METHODS: IL-1 and IL-6 activities were measured by
thymocyte proliferation assay and B9 cell proliferation methyl thiazolyl
tetrazolium (MTT) colorimetric method, respectively. RESULTS: Ro 0.01-1 mumol.L-1
obviously inhibited FFDP-induced release of IL-1 and IL-6 from mouse peritoneal
macrophages. CONCLUSION: Ro exerted inhibitory effects on FFDP-induced release of
IL-1 and IL-6 in vitro.
PMID- 10678096
TI - Effects of opioid receptor agonists on cAMP second messenger system.
AB - AIM: To study the mechanism underlying the difference in physical dependence
potential of morphine (Mor), methadone (Met), buprenorphine (Bup), etorphine
(Eto), and dihydroetorphine (DHE). METHODS: Adenylate cyclase of NG108-15 cells
were used for studying the effects of different opiates on cAMP second messenger
system. RESULTS: Bup, DHE, and Eto were distinct from Mor in naloxone
precipitated rebound response of cAMP in NG108-15 cells chronically treated with
these opiates. Naloxone given to NG108-15 cells treated with Mor for 24 h
produced marked rebound response of adenylate cyclase. While no such rebound
response was detected when the cells were treated with Bup, DHE, and Eto for 24
h. The naloxone-induced rebound response of cAMP in chronic Met-treated NG108-15
cells was also lower than that in chronic Mor-treated NG108-15 cells. Following a
prolonged exposure to Bup, DHE, and Eto for 72 h, the naloxone-induced rebound
response of cAMP in these cells was still markedly lower than that in Mor-treated
cells. The substitution of Mor with Bup, Met, DHE, and Eto inhibited naloxone
induced rebound response of cAMP in chronic Mor-treated NG108-15 cells.
CONCLUSION: There were distinct differences among these opiates in regulating
cAMP second messenger system, which was related to their physical dependence
potential.
PMID- 10678097
TI - Anti-inflammatory and nitric oxide-inhibiting properties of granulocyte colony
stimulating factor.
AB - A proposed scheme between the possible interactions of pro- and anti-inflammatory
cytokines, NO and G-CSF during severe inflammation/infection is presented. Taken
together, these data indicate that G-CSF exhibits anti-inflammatory properties
which may prove to be beneficial in situations associated with an increased
activity of the cellular immune system. Since the suppressive effects of G-CSF on
the production of pro-inflammatory mediators like TNF-alpha and nitric oxide are
most likely neither cell type nor tissue specific, it is conceivable that NO
release induced by pro-inflammatory mediators can be reduced by G-CSF in various
organ systems and in different forms of shock. In this context, G-CSF might
represent a counterregulatory mechanism directed against a downstream oriented
inflammatory response to infection. Therefore, the investigation of G-CSF in the
prophylaxis of nonneutropenic infections, sepsis, and other severe inflammatory
disorders seems reasonable.
PMID- 10678098
TI - Vascular effects of estrogens: rapid actions, novel mechanisms, and potential
therapeutic implications.
AB - Although estrogen-dependent effects on the vasculature were first observed more
than a century ago, many of the mechanisms by which estrogens interact with the
vascular wall have been identified only in the past 15 years. Estrogens bind to
vascular estrogen receptors (ER), including the ER alpha, the novel ER beta as
well as to membrane-bound receptors. Estrogens have direct effects in human
coronary and internal mammary arteries by inducing rapid, endothelium-independent
relaxation, enhancement of endothelial function and inhibition of
vasoconstriction by vasoactive agonists. Furthermore, estrogens contribute to
vascular homeostasis through modulation of gene expression, changes in membrane
potentials, as well as expression and function of receptors. In addition,
estrogens interfere with the activity of vasoactive peptides and vascular enzymes
and act as natural antioxidants. Some of these effects have also been observed
for phyto-estrogens, which are important dietary components in Asian countries.
In the vasculature, the sum of these actions of estrogens results in
vasodilatation and inhibition of vascular cell growth. Accordingly, estrogens
have been shown to improve vascular function of animals and humans and to inhibit
the response to injury after balloon angioplasty and the progression of
atherosclerosis. Prospective clinical studies are ongoing to determine whether
replacement therapy with estrogen or derivatives provides an alternative to lower
cardiovascular mortality in postmenopausal women.
PMID- 10678099
TI - Comparison of effects of surfactant and inhaled nitric oxide in rabbits with
surfactant-depleted respiratory failure.
AB - AIM: To compare effects of pulmonary surfactant and inhaled nitric oxide (iNO) in
improvement of survival and blood oxygenation in ventilated rabbits with acute
hypoxic respiratory failure induced by repeated bronchoalveolar lavage (BAL).
METHODS: After BAL all the rabbits had more than 50% reduction of dynamic lung
compliance (Cdya), 50% increment of resistance of respiratory system (Rrs), and
an increase of mean oxygenation index (OI) from 1 to 22. The rabbits were then
randomly allocated to groups receiving (1) mechanical ventilation only (Control),
(2) iNO 0.8 mumol.L-1 (20 ppm) (NO), (3) intratracheal bolus surfactant
phospholipids at 100 mg.kg-1 (Surf), and (4) combined surfactant at 100 mg.kg-1
with inhaled NO at 0.8 mumol.L-1 (Surf + NO). All the rabbits were ventilated
with standardized tidal volume (8-10 mL.kg-1) for another 8 h or until early
death. RESULTS: The rabbits in both control and NO groups had the lowest survival
rate, deterioration of lung mechanics and OI, whereas those in the Surf and Surf
+ NO groups had modestly improved Cdyn, Rrs, and OI. Only rabbits in the Surf +
NO group had significantly improved survival rate and alveolar expansion.
CONCLUSION: Surfactant with or without iNO is more effective compared to the
control and iNO groups in rabbit, suggesting that iNO is not effective unless a
method to recruit alveoli is applied.
PMID- 10678100
TI - dl-3-n-butylphthalide attenuates reperfusion-induced blood-brain barrier damage
after focal cerebral ischemia in rats.
AB - AIM: To study the protective effect of dl-3-n-butylphthalide (NBP) on blood-brain
barrier (BBB) damage induced by reperfusion following focal cerebral ischemia.
METHODS: Focal cerebral ischemia in rats was performed by inserting a nylon
suture into intracranial segment of internal carotid artery to block the origin
of middle cerebral artery and reperfusion by withdrawing the nylon suture.
Permeability of BBB was determined by extravasation of the protein-bound Evans
blue dye to cerebral cortex and further evaluated by immunohistochemical or
electronmicroscopic method. RESULTS: Reperfusion for 3 h following focal cerebral
ischemia for 3 h produced BBB damage which exhibited the increase in
extravasation in cerebral cortex, elevation of the expression of immunoglobulin
(IgG), and pore formation in endothelial cell membrane of capillary in cerebral
cortex. NBP (5-20 mg.kg-1) decreased the extravasation in a dose-dependent
manner. The expression of IgG in cerebral cortex was decreased and the
ultrastructure damage of capillaries was alleviated after treatment with NBP. NBP
20 mg.kg-1 also alleviated brain edema caused by 3-h reperfusion following 3-h
middle cerebral artery occlusion (MCAO). CONCLUSION: NBP has protective effect on
BBB damage induced by reperfusion after MCAO.
PMID- 10678101
TI - Antagonistic effects of shikimic acid against focal cerebral ischemia injury in
rats subjected to middle cerebral artery thrombosis.
AB - AIM: To study the effects of shikimic acid (SA) on focal cerebral ischemic injury
after middle cerebral artery thrombosis (MCAT). METHODS: Thrombosis was induced
by FeCl3 in middle cerebral artery of rats. The influences of SA on neurologic
deficit (ND), infarct size (IS), brain edema, and cerebral blood flow (CBF) in
ischemic region were observed. RESULTS: SA 25 and 50 mg.kg-1 i.p. for 3 d before
MCAT attenuated ND, and reduced IS by 51% and 42%; and decreased brain water
content from 80.7% to 79.8% and 79.9%; and increased CBF after ischemia from
50.2% of the preischemic level to 75.5% and 73.3%, respectively. In pathologic
examination, there was much less thrombosis in MCA in the rat with the
pretreatment by SA 25 mg.kg-1. The extent of brain ischemia was much less than
that of control. CONCLUSIONS: SA reduced focal cerebral ischemic injury induced
by middle cerebral artery thrombosis.
PMID- 10678102
TI - Effects of berbamine on ATP-induced [Ca2+]i mobilization in cultured vascular
smooth muscle cells and cardiomyocytes.
AB - AIM: To study the effects of berbamine (Ber) on [Ca2+]i homeostasis induced by
adenosine triphosphate (ATP) in vascular smooth muscle cells (VSMC) of rabbits
and cardiomyocytes of rats. METHODS: Both cell types were cultured and loaded
with Fura 3-AM. [Ca2+]i was measured by fluorescent intensity (FI) in each cell
with confocal microscopy. RESULTS: (1) ATP 30 mumol.L-1 elevated [Ca2+]i in VSMC
and cardiomyocytes, FI values reached 660 +/- 258 and 1058 +/- 252 from 250 +/-
84 and 218 +/- 76 at 19 s +/- 5 s and 11.8 s +/- 2.4 s, but FI in nucleus was not
changed in VSMC. (2) Ber 30 mumol.L-1 did not affect the resting FI in both cell
types, but prolonged the time to peak (P < 0.01) and reduced the FI elevated by
ATP (P < 0.01), but not completely inhibited even at 100 mumol.L-1. (3) In D
Hanks' solution or in the presence of egtazic acid (EGTA) 3 mmol.L-1, the
inhibitory effect of Ber was not seen (P > 0.05). (4) All effects of Ber on ATP
induced [Ca2+]i mobilization were similar to those of Ver 10 mumol.L-1.
CONCLUSION: In VSMC and cardiomyocytes, ATP-induced CA2+ influx was inhibited by
Ber and Ver, while the Ca2+ release was not.
PMID- 10678103
TI - Antiviral effects of rhIFN-alpha 1 against seven influenza viruses.
AB - AIM: To study the antiviral effects of rhIFN-alpha 1 (Chinese silkworm gene
recombinant interferon alpha 1) on 7 influenza viruses in MDCK cells and in mouse
pneumonia caused by PR8 virus. METHODS: 100TCID50 virus (H1N1, H2N2, H3N3, type
B, type C, clinical A1, and clinical B) were inoculated into MDCK cells, PR8
viruses were dropped nasally in mice, the antiviral effects of rhIFN-alpha 1 were
observed. RESULTS: The minimal effective concentrations of rhIFN-alpha 1 against
these 7 influenza viruses were 12.5, 25, 50, 25, 12.5, 25, and 12.5 kU.L-1,
respectively. The infectious therapeutic indices of rhIFN-alpha 1 to these
viruses in MDCK cells were 8 x 10(3), 4 x 10(3), 2 x 10(3), 4 x 10(3), 8 x 10(3),
4 x 10(3), and 8 x 10(3), respectively. The inhibitory indices of rhIFN-alpha 1
to the 7 influenza viruses in MDCK cells were 3.6, 4.7, 3.5, 3.3, 3.9, 4.6, and
3.5, respectively. The rhIFN-alpha 1 inhibited the intracellular replication of
influenza viruses effectively, but did not kill viruses directly. The rhIFN-alpha
1 prolonged the life span of mice infected with pneumonia by influenza virus A
strain PR8 to 94.2%-132.7%. It inhibited the inflammation and hyperplasia of
interstitial fibers, and decreased the virus titer. The inhibitory rates of rhIFN
alpha 1 to pulmonary-indice were 14.8%-37.4%. CONCLUSION: rhIFN-alpha 1 inhibited
the proliferation of influenza virus and improved the symptom of mouse pneumonia
caused by influenza virus.
PMID- 10678104
TI - Supraspinal D2 receptor involved in antinociception induced by l
tetrahydropalmatine.
AB - AIM: To study the role of dopamine (DA) receptors in l-tetrahydropalmatine (l
THP)-induced antinociception. METHODS: The intraperitoneal (i.p.) and intrathecal
(ith) injections were used to give the drugs. The tail-flick test was used to
assess the nociceptive threshold of rats. RESULTS: By i.p. injection, l-THP (10,
20, 40 mg.kg-1) as well as D2 receptor antagonist spiperone (1, 2, 3 mg.kg-1)
produced dose-dependent antinociceptive effects on the nociception of rats, while
D2 receptor agonist quinpirole, D1 receptor agonist SKF38393, and D1 receptor
antagonist Sch-23390 showed no antinociception. Moreover, l-THP- or spiperone
induced antinociception was markedly attenuated by quinpirole (2, 3 mg.kg-1) but
not SKF38393 or naloxone. On the other hand, ith quinpirole (20, 30, 40
micrograms.kg-1) also induced a dose-dependent antinociception, while ith l-THP,
spiperone, SKF38393, and Sch-23390 did not exhibit any antinociception.
Furthermore, ith spiperone (20, 30, 40 micrograms.kg-1) but not Sch-23390 dose
dependently antagonised the antinociception induced by quinpirole. l-THP (ith,
100, 200, 300 micrograms.kg-1) also dramatically attenuated the quinpirole
induced antinociception with a dose-dependent relationship. CONCLUSION:
Activating the spinal D2 receptor or blocking the supraspinal D2 receptor
produces antinociception. D1 receptor might be not directly involved in the
antinociception. l-THP (as a D2 antagonist) as well as spiperone produces
antinociception via blocking the supraspinal D2 receptor.
PMID- 10678105
TI - CYP2D6 phenotype determines pharmacokinetic variability of propafenone
enantiomers in 16 HAN Chinese subjects.
AB - AIM: To determine the role of the CYP2D6 phenotype in the metabolism of
propafenone (Pro) enantiomers in 16 HAN Chinese subjects. METHODS: Seven very
extensive metabolizers (VEM) and nine intermediate metabolizers (IM) were
enrolled from a Chinese population whose phenotype had been previously assessed
with a dextromethorphan metabolic phenotyping. The blood samples (0-15 h) were
taken after oral administration of a single dose (400 mg) of rac-Pro
hydrochloride. Enantiomeric concentrations of propafenone in plasma were measured
by a reverse-phase HPLC with precolumn derivatization. RESULTS: S-Pro was less
metabolized and had higher plasma concentrations than R-Pro in both CYP2D6
phenotypes. Besides, the T1/2 of R-Pro was longer than that of S-Pro in IM, but
not in VEM. However, there were significant differences in the metabolism of Pro
enantiomers between VEM and IM. The Cmax and AUC of both isomers in the IM group
were higher than those in the VEM group (P < 0.01). The Cl of Pro enantiomers in
IM group was only about half of that in VEM group [(67 +/- 17) vs (133 +/- 28)
L.h-1 for S-Pro, (90 +/- 24) vs (200 +/- 87) L.h-1 for R-Pro, P < 0.01]. The S/R
ratios of T1/2, Tmax, Cmax, Cl, and AUC were not significantly different (P >
0.05). CONCLUSION: CYP2D6 phenotype determines the pharmacokinetic variability of
propafenone enantiomers and existence of IM may be relevant to diminished
capacity of CYP2D6 enzyme in Chinese subjects.
PMID- 10678106
TI - Subtypes of central nicotinic receptors involved in learning and memory.
AB - AIM: To observe the effects of different subtypes of central nicotinic receptor
on learning and memory. METHODS: Passive avoidance response, including step-down
avoidance and step-through avoidance in mice and long-term potentiation (LTP) in
rat hippocampal slices. RESULTS: Hexamethonium (C6) 7 micrograms/mouse and kappa
bungarotoxin (kappa-BTX) 0.6 microgram/mouse inhibited the acquisition of
avoidance conditioning in mice, and kappa-BTX yielded this effect with a dose
response relationship. kappa-BTX 1 mumol.L-1 suppressed the induction of LTP (P <
0.05), but not normal synaptic transmission and maintenance of LTP in rat
hippocampal slices. CONCLUSION: The subtypes of central nicotinic receptor
sensitive to kappa-BTX play an important role in learning and memory.
PMID- 10678107
TI - Effects of tetrandrine on changes of NMDA receptor channel in cortical neurons of
rat induced by anoxia.
AB - AIM: To study the effects of tetrandrine (Tet) on the changes of NMDA receptor
channels in cortical neurons induced by anoxia. METHODS: Cell-attached
configuration of patch-clamp techniques. Anoxia was produced by perfused cells
with 95% N2 + 5% CO2 gassed bath solution. RESULTS: During anoxia, the open time
constant (tau 2), open probability (Po) of 35-pS and 100-pS channels increased.
Tet 7.5 mumol.L-1 reduced the Po of 35-pS and 100-pS channels, 15 and 30 mumol.L
1 inhibited open of 100-pS channel fully, and changed the open time constant of
35-pS from two to single exponential distribution. CONCLUSION: Tet inhibition of
the open of NMDA receptor channels induced by anoxia was one of its protective
mechanisms.
PMID- 10678108
TI - L-pyroglutamic acid protects rat cortical neurons against sodium glutamate
induced injury.
AB - AIM: To evaluate the effects of L-pyroglutamic acid (L-PGA, L-5-oxo-2
pyrrolidinecaroxylic acid) on sodium glutamate-induced neurotoxicity in rat
cortical neurons. METHODS: In primary cortical cultures from 16-d-old fetal rat,
neuronal viability and contents of nitrite in the bathing medium after transient
exposure to sodium glutamate (Glu) were measured; with Fura 2-AM as an
intracellular calcium indicator, AR-CM-MIC cation measurement system was used to
examine cytosolic free calcium ([Ca2+]i). RESULTS: L-PGA 10-80 mumol.L-1,
inhibited Glu (500 mumol.L-1)-induced neuronal loss in a concentration-dependent
manner with IC50 value of (41 +/- 9) mumol.L-1 (95% confidence limits: 30.3-54.7
mumol.L-1). L-PGA also attenuated Glu-induced NO release. L-PGA 1, 3, 10, 30, and
100 mumol.L-1 depressed Glu-caused [Ca2+]i elevation by 20.5%, 34.4%, 47.7%,
70.6%, and 80.4%, respectively. CONCLUSION: L-PGA protects cortical neurons
against Glu-induced neurotoxity which may be related to inhibition of NO
formation or suppression of the rise in [Ca2+]i.
PMID- 10678109
TI - Intrathecal injection of corticotropin inhibited nitric-oxide synthase-positive
neuron increase in rat spinal cord after formalin-induced hyperalgesia.
AB - AIM: To study the effects of corticotropin (Cor) on formalin-induced hyperalgesia
and the change of nitric-oxide synthase (NOS)-positive neurons in spinal dorsal
horn in rats. METHODS: Measurement of pain intensity rating (PIR), NADPH-d
histochemistry, and Fos immunohistochemistry were adopted. RESULTS: The increases
of NOS-positive neurons, Fos, NOS/Fos double labelling neurons of the spinal
dorsal horn and the PIR after formalin injection were markedly inhibited by
intrathecal injecting (ith) Cor (0.5-1.5 U), which were obviously attenuated by L
arginine (Arg, 5-15 nmol, ith), the substrate of NOS. CONCLUSION: Cor inhibits
formalin-induced hyperalgesia by the decrease of NOS-positive neurons in the
spinal dorsal horn of rats.
PMID- 10678110
TI - Effects of pentoxifylline and protein kinase C inhibitor on phorbol ester-induced
intercellular adhesion molecule-1 expression in brain microvascular endothelial
cells.
AB - AIM: To study the potential roles of protein kinase C (PKC) on expression of
intercellular adhesion molecule-1 (ICAM-1) in rat brain microvascular endothelial
cells (RBMEC). METHODS: ICAM-1 expression in RBMEC was measured by ELISA
analyses. RESULTS: Phorbol ester (PMA) enhanced the expression of ICAM-1 in a
concentration (10-100 nmol.L-1) and time (4-16 h)-dependent manner in RBMEC.
Pentoxifylline (PTX) 1-100 mumol.L-1 and the PKC inhibitor H7 5-50 mumol.L-1
prevented PMA-induced stimulation of ICAM-1 expression. At PTX 100 mumol.L-1 and
H7 50 mumol.L-1, they reached maximal inhibitory effects [ICAM-1 expression (A)
from (0.410 +/- 0.014) to (0.175 +/- 0.022) and (0.182 +/- 0.013), respectively;
P < 0.01]. CONCLUSION: Activation of PKC in RBMEC is associated with increased
expression of ICAM-1 in RBMEC. PTX and H7 preincubation may inhibit PKC-induced
up-regulation of ICAM-1.
PMID- 10678111
TI - Hydrolysis of extracellular adenine nucleotides by cultured bovine endocardial
endothelial cells.
AB - AIM: To characterize the ATP diphosphohydrolase (apyrase) of bovine endocardial
endothelial cells, and to compare ecto-adeninenucleotidase activity between
bovine endocardial and aortic endothelial cells (BEEC and BAEC). METHODS: The
nucleotide was analyzed by reversed phase HPLC and apyrase activity was assayed
by inorganic phosphate release. RESULTS: Apyrase inhibitors, both NaN3 10 mmol.L
1 and NaF 20 mmol.L-1, inhibited BEEC apyrase activity by 51% and 38%,
respectively. The inhibitor for Na+/K(+)-ATPase, ouabain, did not affect the
enzyme activity. Edetic acid 5 mmol.L-1 completely inhibited the enzyme activity.
H2O2 0.5 mmol.L-1 downregulated BEEC apyrase activity in a time-dependent manner.
The apyrases activities in BAEC were higher than those in BEEC, while the ecto
AMPase activity in BAEC was much weaker than that in BEEC. CONCLUSION: BEEC have
NaN3- and NaF-sensitive, ouabain-insensitive apyrase activity. BEEC had high ecto
AMPase activities, and low apyrases activities as compared with BAEC.
PMID- 10678112
TI - Effect of artemether on phosphorylase, lactate dehydrogenase, adenosine
triphosphatase, and glucosephosphate dehydrogenase of Schistosoma japonicum
harbored in mice.
AB - AIM: To study the effect of artemether (Art) on phosphorylase (PP), lactate
dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-PDH), and adenosine
triphosphatase (ATPase) of S japonicum. METHODS: Mice infected with S. japonicum
cercariae for 32-38 d were treated i.g. with Art 100-300 mg.kg-1 and killed 24-72
h after treatment for collection of schistosomes. The activities of PP, LDH, and
G-6-PDH were measured by the formation of NADH or NADPH. The activity of ATPase
was measured by the rate of release of inorganic phosphate (Pi) from ATP at 37
degrees C. RESULTS: After infected mice were treated i.g. with Art 300 mg.kg-1
for 24-48 h, the activities of total PP and PPa (active form) increased markedly
in both male and female worms, while PPb (inactive form) showed no or only a
slight increase. At 24-72 h after the above-mentioned mice were treated i.g. with
Art 100-300 mg.kg-1, the inhibitory rates of LDH and G-6-PDH were 9%-59% (male)
and 41%-75% (female) as well as 22%-42% (male) and 74%-89% (female),
respectively. When Art 300 mg.kg-1 was given to infected mice for 24 h, only the
activity of Mg(2+)-ATPase showed marked inhibition in both male and female worms.
At 48 h, the Ca(2+)-ATPase, Mg(2+)-ATPase, and Na(+)-K(+)-ATPase were all
inhibited, the inhibitory rates of 17% (male) and 19% (female), 32% (male) and
48% (female) as well as 29% (male) and 44% (female), respectively. CONCLUSION: In
schistosomes, the increase in the activity of AMP-independent PPa induced by Art
may enhance the decomposition of glycogen and the inhibition of LDH by Art could
reduce the formation of lactate. Moreover, Art exerts a potent inhibition on the
G-6-PDH activity of the female S japonicum.
PMID- 10678113
TI - Schizontocidal effects of oral artesunate on Plasmodium berghei in mice and P
knowlesi in monkeys.
AB - AIM: To study the blood schizontocidal effect of oral artesunate on P berghei in
mice and P knowlesi in monkey. METHODS: Effects of artesunate and chloroquine
were detected with "4-day test" and "28-day test" on P berghei in mice and "7-day
test" on P knowlesi in Macaca mudatta. RESULTS: The suppressive efficacy of oral
artesunate was inferior to chloroquine on P berghei K173 strain but the time for
50% and 90% reduction and the time of clearance of parasitemia was 10-15 h
shorter than that of chloroquine. Its curative effect on RC/K173 line was
markedly superior to that of chloroquine. Moreover, artesunate showed no cross
resistance with chloroquine, index of resistance I90 was only 1.4. At 31.6, 10.0,
and 3.16 mg.kg-1, artesunate and chloroquine oral administrations cured P
knowlesi in all monkeys. Recrudescence did not occur in 105 d. CONCLUSION: The
study of effects of oral artesunate in P berghei/mice and P knowlesi/Macaca
mulatta model provided a useful index for clinical trial.
PMID- 10678114
TI - Cytokines enhance nitric oxide production from human BT325 astrocytoma cells.
AB - AIM: To study the effects of lipopolysaccharides (LPS) and pre-inflammatory
cytokines on nitric oxide (NO) production from cultured astrocytes. METHODS:
Nitrites in supernatants were measured with Griess assay. RESULTS: The NO
production from cultured human BT325 astrocytoma cells started when cultured for
4 h, reached the peak concentration (15.0 mumol.L-1) at 12 h, maintained a high
level (15.0-17.5 mumol.L-1) up to 72 h, and was enhanced by LPS 1 mg.L-1,
interferon-gamma (IFN-gamma) 100 kU.L-1, tumor necrosis factor-alpha (TNF-alpha)
100 kU.L-1, interleukin (IL)-1 100 kU.L-1, or IL-2 100 kU.L-1. The enhancements
of TNF-alpha, IL-1, IL-2, or the mixture of the above four cytokines were higher.
CONCLUSION: Stimulants and pre-inflammatory cytokines enhance astrocytes
producing NO.
PMID- 10678115
TI - Effect of recombinant human basic fibroblast growth factor on stomach ulcers in
rats and mice.
AB - AIM: To study the curative effects of recombinant human basic fibroblast growth
factor (rh-bFGF) on gastric ulcer healing. METHODS: Pylorus ligated, water
immersion stress-induced, reserpine-induced, and acetic acid-induced gastric
ulcers in rats or mice were prepared. Morphometric analyses on ulcer were
performed using microscope and true color image analysis system. The DNA and RNA
contents were measured by diphenylamine method and orcinol method, respectively.
RESULTS: In acetic acid-induced gastric ulcers in rats, rh-bFGF 2.5-40 kU.kg-1
i.g. accelerated the chronic ulcer healing with a bell-shaped dose-effect curve
and the best dosage was 10 kU.kg-1. The regenerated gland epithelium width,
density of capillaries in granulation tissue, and collagen content in scar
tissues obviously increased in rh-bFGF-treated groups. Simultaneously, rh-bFGF
promoted the differentiation and maturation of regenerated glands around ulcers.
rh-bFGF 2-4 kU.kg-1 s.c. also increased the synthesis of RNA in ulcer tissues. In
acute gastric ulcers, rh-bFGF i.g. was only effective on pylorus ligated ulcers,
but showed no effect on total acid output and pepsin activity in gastric juice of
rats. CONCLUSION: rh-bFGF promoted the gastric ulcer healing and improved the
quality of gastric ulcer healing.
PMID- 10678116
TI - Pharmacological regulation of striatal gene expression by metabotropic glutamate
receptors.
AB - Metabotropic glutamate receptors (mGluR) are densely expressed by striatal medium
spiny neurons. Activation of mGluR in this brain region alters local transmitter
release and behaviors of experimental animals. In particular, mGluR regulate
transcription factor and neuropeptide gene expression in striatal neurons through
their connections with multiple intracellular effectors. This prominent
involvement of mGluR in overall cellular activity is pivotal for the development
of neuronal plasticity underlying long-term adaptive changes in cellular
physiology related to a variety of neurologic disorders. Accumulating evidence
demonstrates that the subtypes of mGluR have distinct effects on gene expression:
group I subtypes facilitating, and group II/III subtypes inhibiting, gene
expression. Thus, the mGluR can be considered as promising targets in the
development of novel therapeutic drugs that can relieve neurologic disorders
resulting from dysfunction of the striatum.
PMID- 10678117
TI - Correlation between cytochrome P-450 CYP2D6 (CYP2D6) genotype and phenotype.
AB - AIM: To study the correlation between CYP2D6 genotype and its phenotype. METHODS:
CYP2D6 genotyping was made by detecting CYP2D6*3, *4, *6, and *7 alleles with an
allele-specific polymerase chain reaction procedure. RESULTS: The CYP2D6
genotypes were well correlated with its phenotypes in all 125 extensive
metabolizers and in 43 poor metabolizers. Extensive metabolizers had at least one
wildtype CYP2D6 gene and the genotypes were *1/*1, *1/*3, and *1/*4. Poor
metabolizers were found to be homozygous mutants of CYP2D6 gene and the genotypes
were *3/*4, *4/*4, *3/*6, *4/*7, *4/*6, and *6/*6. CONCLUSION: Genotype could be
used to screen variations of CYP2D6 expression.
PMID- 10678118
TI - Presynaptic release of ATP from superior cervical ganglion of rats modulated by
various receptors.
AB - AIM: To determine whether adenosine 5'-triphosphate (ATP) is released from the
superior cervical ganglion (SCG) of rats and whether the release is regulated by
presynaptic mechanism. METHODS: Using the luciferin-luciferase technique.
RESULTS: Electric stimulation evoked the release of ATP from the rat SCG.
Adenosine (100 mumol.L-1), P1(A1) purinoceptor agonist N6-cyclopentyladenosine
(0.1 mumol.L-1), the muscarinic agonist oxotremorine (1 mumol.L-1), and 5
hydroxytryptamine (100 mumol.L-1) decreased the evoked release of ATP from the
rat SCG. On the contrary, P1(A1) purinoceptor antagonist 8-cyclopentyl-1,3
dipropylxanthine (10 nmol.L-1), P2 purinoceptor antagonist pyridoxal-5-phosphate
6-azophenyl-2',4-disulphonic acid (10 mumol.L-1), muscarinic antagonist atropine
(1 mumol.L-1), alpha 2 adrenoceptor antagonist yohimbine (3 mumol.L-1), D2
dopamine receptor antagonist sulpiride (20 mumol.L-1), and histamine (100 mumol.L
1) increased the evoked release of ATP from the rat SCG. CONCLUSION: ATP is
released from the rat SCG and the release of ATP can be presynaptically modulated
by P1(A1), P2, muscarinic, alpha adrenergic, D2, 5-HT, and H1 receptor agonists
and antagonists.
PMID- 10678119
TI - Influence of agmatine in adaptation of cAMP signal transduction system of opiate
receptors.
AB - AIM: To observe attenuative effects of agmatine on opiate desensitization and
substance dependence. METHODS: Guanosine 5'-O-(3-[35S] thiotriphosphate)
([35S]GTTP) binding and cellular cyclic AMP (cAMP) level were determined by
radioligand binding assay and radioimmunoassay in NG108-15 cells, respectively.
RESULTS: Agmatine increased stimulative action of opioids on [35S]GTTP binding by
about 35% and inhibitory effects of opioids on cellular cAMP concentration by
about 114.3% in NG108-15 cells pretreated with opioids. On the other hand, it
also inhibited cAMP over-shooting by 214.9% of morphine substance dependent cells
precipitated by naloxone compared with that of control. These effects of agmatine
were antagonized by idazoxan in a concentration-dependent manner. CONCLUSION:
Agmatine reversed the formative process of adaptation in cAMP signal transduction
cascade.
PMID- 10678120
TI - Effects of fenfluramine combined with electroacupuncture on monoamine release in
periaqueductal gray of rat brain.
AB - AIM: To study the changes of monoamines in ventrolatoral periaqueductal gray of
rat brain before and after electroacupuncture (EA) analgesia (EAA) was enhanced
by fenfluramine (Fen), a 5-hydroxytryptamine (5-HT) releaser. METHODS: Monoamines
were collected by in vivo microdialysis and measured by HPLC connected with
electrochemical detector. RESULTS: The level of norepinephrine (Nor) after EA was
decreased (P < 0.05 vs NS group). The contents of 5-HT, 5-hydroxyindol acetic
acid (5-HIAA), dopamine (DA), and homovanillic acid (HVA) in periaqueductal gray
dialysate were increased (P < 0.05 vs NS group). When Fen was combined with EA,
the level of 5-HT and 5-HIAA were further increased (P < 0.05 vs NS + EA group).
There was no obvious change of Nor, DA, and HVA. CONCLUSION: Fen potentiating EAA
may be related to further activation of serotoninergic system.
PMID- 10678121
TI - Huperzine-A capsules enhance memory and learning performance in 34 pairs of
matched adolescent students.
AB - AIM: To study the efficacy of huperzine-A capsules (Hup) on memory and learning
performance of adolescent students. METHODS: Using double-blind and matched pair
method, 34 pairs of junior middle school students complaining of memory
inadequacy were divided into two groups by normal psychological health inventory
(PHI), similar memory quotient (MQ), same sex and class. The Hup group was
administrated orally 2 capsules of Hup (each contains Hup 50 micrograms) b.i.d.,
and the placebo group was given 2 capsules of placebo (starch and lactose inside)
b.i.d. for 4 wk. RESULTS: At the end of trial, the Hup group's MQ (115 +/- 6) was
more than that of the placebo group (104 +/- 9, P < 0.01), and the scores of
Chinese language lesson in the Hup group were elevated markedly too. CONCLUSION:
The Hup capsules enhance the memory and learning performance of adolescent
students.
PMID- 10678122
TI - Effect of moxonidine on carotid sinus baroreflex in anesthetized rats.
AB - AIM: To study the effect of moxonidine (Mox) on carotid sinus baroreflex.
METHODS: By perfusing the carotid sinus in anesthetized rats, the functional
parameters of baroreflex were measured. The femoral artery was perfused with
constant flow and the change of perfusing pressure was recorded to determine the
effect of Mox on vascular tone. RESULTS: Mox 32 and 100 mumol.L-1 shifted the
functional curve of carotid sinus baroreflex to the right and upward, with the
reduction in peak slope and in reflex decrease of mean arterial pressure,
suggesting that Mox produced an inhibitory effect on baroreflex. The effect of
Mox 100 mumol.L-1 on baroreflex was completely blocked by efaroxan 100 mumol.L-1.
Mox increased vascular resistance. CONCLUSION: Mox inhibits carotid baroreflex
via its constrictive action on sinus wall.
PMID- 10678123
TI - Effects of allitridi on intracellular Ca2+ concentration in isolated rat brain
cells.
AB - AIM: To study actions of allitridi extracted from garlic on intracellular calcium
in isolated rat brain cells. METHODS: Brain cells were isolated from newborn rat
brain with Fura 2-AM measurements of intracellular Ca2+ concentration ([Ca2+]i).
RESULTS: Allitridi 1-100 mumol.L-1 concentration-dependently blocked increases of
[Ca2+]i caused by potassium chloride and sodium glutamate (Glu) with IC50 of 59.7
and 69.9 mumol.L-1 respectively. Allitridi 100 mumol.L-1 blocked norepinephrine
(Nor)-induced [Ca2+]i elevation. CONCLUSION: Allitridi is an effective agent for
blocking the [Ca2+]i increase caused by potassium chloride, Nor and Glu.
PMID- 10678124
TI - Target selectivity of MAPK phosphorothioate antisense ODN on p42/p44, p38 MAPK,
and JNK protein expression and its inhibitory effect on VSMC DNA synthesis.
AB - AIM: To analyze the target selective and sequence-specific inhibitory effect of
mitogen-activated protein kinase (MAPK) phosphorothioate antisense
oligodeoxynucleotides (ODN) on p42/p44, p38 MAPK, c-jun NH2-terminal protein
kinases (JNK) protein expression, and DNA synthesis in vascular smooth muscle
cell (VSMC). METHODS: Using a phosphorothioate-protected 17-mer antisense MAPK
ODN directed against the initiation of translation sites of the p42/p44 MAPK
isoforms by liposomal transfection to deplete cultured rat, rabbit, and fetal
calf VSMC MAP kinases. The 17-mer sense and random sequence MAPK ODN were used as
controls. After liposomal transfection, cells were exposed to 20% serum for 24 h,
and then harvested in lysis buffer. P42/p44, p38 MAPK, and p46/p58 JNK protein
expression were measured by Western blot. DNA synthesis was measured by
[3H]thymidine incorporation. RESULTS: Treatment with MAPK antisense ODN (0.1-0.8
mumol.L-1) for 48 h reduced phosphored p42/p44 MAPK protein expression but
without effect on p38 MAPK and JNK expression, and inhibited cultured rat,
rabbit, and fetal calf VSMC [3H]thymidine incorporation stimulated by 20% serum
in a concentration-dependent manner. CONCLUSION: The MAPK antisense ODN target
selectively and sequence-specifically reduces the p42/p44 MAPK protein expression
and concentration-dependently inhibits proliferation of rat, rabbit and fetal
calf VSMC.
PMID- 10678125
TI - Effect of advanced glycosylation end products on diacylglycerol signaling pathway
in cultured rat aortic smooth muscle cells.
AB - AIM: To investigate whether diacylglycerol (Dia) signaling pathway is stimulated
by advanced glycosylation end products (AGEP) and to determine effect of vitamin
E and aminoguanidine on Dia level induced by AGEP in cultured rat aortic vascular
smooth muscle cells (VSMC). METHODS: The effect of AGEP on Dia level in cultured
VSMC was measured by radio-enzymatic assay. Quantitative measurements of
[32P]phosphatidic acid were performed by thin-layer chromatography and
autoradiography. RESULTS: The Dia level in VSMC incubated with AGEP-BSA was
markedly increased in a concentration-dependent, biphasic manner. The early phase
was rapid and transient, peaking at 15 s. The late phase reached the maximal
level at 10 min and decayed slowly. The Dia levels in VSMC exposed to different
concentrations of AGEP-BSA and AGEP-BSA glycosylated for various periods were
greatly increased compared with control group. Vitamin E 50, 100 nmol.L-1
prevented the AGEP-BSA-stimulated elevation of Dia level in VSMC, from (940 +/-
43) pmol.L-1 to (599 +/- 38), (290 +/- 21) pmol.L-1, respectively. In
aminoguanidine-treated AGEP-BSA groups, Dia level in the cells incubated with the
same concentration of AGEP-BSA (100, 200 mg.L-1) were decreased to (260 +/- 8)
and (289 +/- 10) pmol.L-1, respectively. Early glycosylated low-density
lipoproteins (LDL) did not affect Dia level. CONCLUSION: AGEP causes a robust
stimulation of Dia signaling pathway in VSMC. Vitamin E and aminoguanidine
attenuate the production of Dia.
PMID- 10678126
TI - Inhibitory effects of sodium quercetin monosulfate on pig platelet aggregation
induced by thrombin.
AB - AIM: To study the inhibitory effects of sodium quercetin monosulfate (SQMS) on
pig platelet aggregation induced by thrombin. METHODS: Platelet aggregation was
analyzed by turbidimetry. Cytosolic free calcium concentration ([Ca2+]i) was
determined by Fura-2 fluorescence. Activity of protein kinase C (PKC) was assayed
by incubating PKC with histone III S and [gamma-32 P] ATP. The cytoskeletal
proteins were precipitated by Triton X-100 and separated by SDS-PAGE. RESULTS:
SQMS inhibited the platelet aggregation induced by thrombin 500 U.L-1 with IC50
132 (50-347) mumol.L-1. SQMS inhibited Ca2+ influx in blood platelets induced by
thrombin 500 U.L-1 in the presence of extracellular Ca2+ 1 mmol.L-1 with IC50 20
(9-46) mumol.L-1; SQMS inhibited the internal Ca2+ release in the absence of
extracellular Ca2+. SQMS also decreased [Ca2+]i level in quiescent blood
platelets. SQMS (10-160 mumol.L-1) inhibited the activity of cytosolic PKC from
blood platelets in a concentration-dependent manner, but had no effect on
membrane PKC. SQMS (20-80 mumol.L-1) inhibited the actin polymerization induced
by thrombin 500 U.L-1 inblood platelets in a concentration-dependent manner.
CONCLUSION: SQMS inhibited pig platelet aggregation induced by thrombin and its
mechanism might be due to its inhibitions of Ca2+ influx, internal Ca2- release,
PKC activity, and actin polymerization.
PMID- 10678127
TI - Effects of MK-447 on platelet shape change, aggregation, and ATP release by
collagen, ADP, and stable analogue of thromboxane A2 in rabbit platelets.
AB - AIM: To investigate the effects of MK-447 on platelet shape change, aggregation,
and ATP release by collagen (Col), ADP, and stable analogue of thromboxane A2
(STA2) in rabbits. METHODS: Platelet shape change and aggregation were quantified
in light transmission by turbidimetric method and release reaction was assessed
by the amount of ATP in platelet-rich plasma (PRP). RESULTS: (1) MK-447 100-700
mumol.L-1 caused only the shape change, which was not inhibited by indometacin 3
mumol.L-1. Platelet shape changes by Col, ADP, and STA2 were reduced (P < 0.01)
after the addition of MK-447. The lag phase was prolonged (P < 0.01) in Col and
shortened (P < 0.01) in ADP. (2) MK-447 reduced the aggregation by Col 5 mg.L-1
(P < 0.01), and enhanced that by ADP 0.3-10 mumol.L-1 and STA2 0.1-3 mumol.L-1 (P
< 0.01). (3) The release reaction by STA2 1-3 mumol.L-1 was also increased (P <
0.01). The effects of MK-447 on STA2 were not inhibited by S-145. CONCLUSION: MK
447 induced the platelet shape change, and showed the dual effects, inhibition or
enhancement, on the actions by different aggregating agents.
PMID- 10678128
TI - Inhibitory effects of estradiol on inward rectifier and delayed rectifier K+
currents in guinea pig ventricular myocytes.
AB - AIM: To study the effects of estradiol (Est) on inward rectifier K+ (IK1) and
delayed rectifier K+ (IK) channels in isolated guinea pig ventricular myocytes.
METHODS: Using whole cell patch-clamp recording techniques. RESULTS: Est 10
mumol.L-1 and 100 mumol.L-1 decreased the action potential duration, APD50, from
(474 +/- 71) ms to (330 +/- 75) ms and (229 +/- 67) ms (n = 7 cells of 7 guinea
pigs, P < 0.05), respectively. Est 100 mumol.L-1 also decreased APD90 from (587
+/- 60) ms to (418 +/- 79) ms (n = 7, P < 0.05). Est inhibited IK tail current
(IK.tail) concentration-dependently. IK.tail was depressed 53% (n = 5, P < 0.05)
at 10 mumol.L-1 and 80% (n = 5, P < 0.01) at 100 mumol.L-1 compared with control.
Est > or = 10 mumol.L-1 blocked IK1. The maximal inhibition of inward current of
IK1 occurred at -100 mV test potential was 49% (n = 5, P < 0.01) and outward
current of IK1 at -40 mV was 72% (n = 5, P < 0.01). The reverse potential shifted
negatively, from -70 to -76 mV. CONCLUSION: Est possessed blocking effects on
both IK1 and IK channels in guinea pig ventricular myocytes.
PMID- 10678130
TI - Hypotensive effect of tenuifolic saponin and its mechanism.
AB - AIM: To study the effect of tenuifolic saponin (TS) on arterial pressure.
METHODS: Mean arterial pressure (MAP) was recorded from left carotid artery in
rat which was anesthetized with urethane and then injected i.v. gtt with a
transfusion of NaCl 0.15 mol.L-1. Systolic blood pressure (SBP) of conscious rat
and renovascular hypertensive rat (RVHR) was measured by tail cuff method.
RESULTS: TS 2, 4, 8 mg.kg-1 i.v., 20 and 40 mg.kg-1 i.g. reduced the MAP by 31%,
37%, 50%, 21%, and 31%, respectively. Bilateral vagotomy plus atropine (Atr)
i.v., or pretreatment with diphenhydramine hydrochloride (Dip) failed to
influence TS effect. Lack of effect of TS on carotid-occlusion-induced- or
epinephrine (Epi)-induced-hypertensive response was found. SBP in conscious rat
and RVHR was suppressed, highest by 38.0% and 26.8% at 60 and 90 min, maintaining
at least 2 and 3 h, respectively, after i.g. TS 40 mg.kg-1. CONCLUSION: TS
reduced the arterial pressure, not related to vagus excitation, ganglionic
blockade, and peripheral alpha-adrenergic-, M-cholinergic-, and H1-receptors.
PMID- 10678129
TI - Protective effects of Ginkgo biloba extract on cultured rat cardiomyocytes
damaged by H2O2.
AB - AIM: To investigate the influence of Ginkgo biloba extract (GbE) on
cardiomyocytes damaged by H2O2. METHODS: Cultured rat cardiomyocytes were divided
into 3 groups randomly: control group; H2O2 (2.5 mmol.L-1) group; H2O2 2.5 mmol.L
1 + GbE 150 mg.L-1 group. The cardiomyocytes were cultured in MEM (Eagle's) at 37
degrees C in the presence of 5% CO2 for 4 h. Lactate dehydrogenase (LDH) was
assayed by colorimetric method. Lipid peroxidation was determined by measuring
thiobarbituric acid-reactive substances. Ultrastructure was viewed under
transmission electron microscope. RESULTS: Compared with the control group, LDH
leakage and malondialdehyde (MDA) content increased in H2O2 group, LDH increased
from (2166 +/- 247) U.L-1 to (5180 +/- 648) U.L-1, MDA increased from (3.5 +/-
0.2) nmol/10(6) cells to (7.2 +/- 0.4) nmol/10(6) cells (P < 0.01). The
ultrastructure was damaged seriously. GbE inhibited the increase of LDH leakage
and MDA content induced by H2O2. In this group, LDH decreased from (5180 +/- 648)
U.L-1 to (3496 +/- 386) U.L-1, MDA decreased from (7.2 +/- 0.4) nmol/10(6) cells
to (4.8 +/- 0.9) nmol/10(6) cells (P < 0.01). Ultrastructure of cells was also
protected by GbE. CONCLUSION: GbE protected the cardiomyocyte against H2O2
injury, the protective action was attributed to its antiperoxidative effect.
PMID- 10678131
TI - Glutathione antagonized cyclophosphamide- and acrolein-induced cytotoxicity of
PC3 cells and immunosuppressive actions in mice.
AB - AIM: To study the antagonistic effect of glutathione (GSH) on toxicity of PC3
cell induced by cyclophosphamide (Cyc) and acrolein (Acr) and on
immunosuppressive actions caused by Cyc. METHODS: Splenocyte, PC3 cell
proliferation and cell protein content were measured by tetrazolium (MTT) assay
and Coomassie brilliant blue assay. Serum anti-SRBC hemolysin, agglutinin, and
splenocyte proliferation were measured in normal and S-180-bearing mice. Tumors
were weighed. RESULTS: Pretreatment with GSH 2 mmol.L-1 reduced splenocyte
proliferation inhibition from 18.64%, 49.72% to 6.78%, 18.36% (induced by Cyc 1,
and 5 mmol.L-1), and PC3 cell proliferation inhibition from 27.7%, 45.3%, and
74.6% to 14.6%, 18.8%, and 49.1% (induced by Cyc 1, 3, and 5 mmol.L-1), and from
62.6%, 85.4%, and 90.6% to 41.9%, 57.7%, and 86.4% (induced by Acr 10, 25, and 50
mumol.L-1), respectively. In normal mice, s.c. GSH 75 or 150 mg.kg-1 b.i.d. x 5 d
after i.p. Cyc 40 mg.kg-1, the hemolysin and the splenocyte proliferation were
higher than those in normal mice i.p. Cyc 40 mg.kg-1 alone. Hemolysin, serum
agglutinin, and splenocyte proliferation in S-180-bearing mice given s.c. GSH 150
mg.kg-1 b.i.d. x 10 d after i.p. Cyc 40 mg.kg-1 were also markedly higher than
those in S-180-bearing mice given i.p. Cyc alone. But, according to tumor weight,
GSH did not interfere the antitumor activity of Cyc in S-180-bearing mice.
CONCLUSION: GSH exhibited protective effects against Cyc and Acr, but had no
effect on the antitumor action of Cyc.
PMID- 10678132
TI - R-dl-verapamil downmodulates multidrug resistance of KBv200 cells to vincristine
and doxorubicin.
AB - AIM: To study the attenuation of multidrug resistance (MDR) by R-dl-verapamil (R
Ver) and the acute animal toxicity of R-Ver, and to compare these results of R
Ver with the results of dl-verapamil (Ver). METHODS: Cytotoxicity was determined
by tetrazolium (MTT) assay. Cellular accumulation of doxorubicin (Dox) was
measured by fluorescence spectrophotometry. Acute animal toxicity was tested by
i.p. drug administration in BALB/c mice. RESULTS: R-Ver attenuated MDR of KBv200
cells to vincristine (VCR) and Dox. This attenuation ability was dose-related,
and was also dependent on drug exposure time. R-Ver 1.25 mumol.L-1 increased the
sensitivity of KBv200 cells to VCR (P < 0.01) with a 24-h period of drug
exposure. R-Ver downmodulated MDR and increased cellular Dox accumulation of
KBv200 cells as effectively as Ver, but possessed lower acute toxicity in BALB/c
mice. While LD50 of Ver was 60 (49-73) mg.kg-1, LD50 of R-Ver was 166 (137-202)
mg.kg-1. CONCLUSION: R-Ver downmodulated the MDR to VCR and Dox at 1.25 mumol.L
1, and this effect on VCR can be realized with drug exposure duration of 24 h.
PMID- 10678133
TI - Bronchodilating effects of bambuterol on bronchoconstriction in guinea pigs.
AB - AIM: To study the effects of bambuterol (Bam) on bronchoconstriction in guinea
pigs. METHODS: Bronchospasm induced by histamine aerosol, lung resistance (RL)
and dynamic lung compliance (Cdyn) changes induced by ovalbumin aerosol in vivo,
isolated resting lung parenchyma strips, and carbamylcholine-induced tracheal
constriction in vitro in guinea pig were investigated. RESULTS: Bam dose
dependently prolonged the time to histamine-induced collapse, ED50 values (95%
confidence limits) of Bam intragastric gavage (i.g.) after 1 h, 4 h, and 24 h
were 0.74 (0.60-0.91), 0.75 (0.61-0.91) and 1.00 (0.77-1.30) mg.kg-1,
respectively. Bam 2 or 10 mg.kg-1 i.g. 2 h before ovalbumin aerosol partly or
almost completely inhibited bronchial challenge of ovalbumin-induced change of RL
and Cdyn. Bam 0.1-1.0 mumol.L-1 gave a weak relaxation on isolated tracheal
strips induced by carbamylcholine and failed to relax the isolated resting lung
parenchyma strips in guinea pig. CONCLUSION: Bam showed a long-acting
bronchodilation by its slow metabolism in vivo.
PMID- 10678134
TI - Pharmacokinetics of 2-hydroxyflutamide, a major metabolite of flutamide, in
normal and CCl4-poisoned rats.
AB - AIM: To study the pharmacokinetics of 2-hydroxyflutamide (HF), a major active
metabolite of flutamide (Flu), in normal and CCl4-poisoned rats. METHODS: Normal
and CCl4-poisoned rats were given i.g. HF 25 mg.kg-1. HF concentrations of plasma
were determined by HPLC with YWG C 18 column, Flu was used as an internal
standard. The mobile phase was composed of methanol: water = 3:2 (vol), and
absorbance was measured at lambda 295 nm. RESULTS: HF elimination was inhibited
in CCl4-poisoned rats compared with normal rats. K decreased from (0.11 +/- 0.05)
to (0.05 +/- 0.01) h-1 (P < 0.01), T1/2 was prolonged from (6.8 +/- 1.9) to (14
+/- 4) h (P < 0.01), Cl decreased from (0.18 +/- 0.06) to (0.12 +/- 0.02) L.kg
1.h-1 (P < 0.05), AUC increased from (149 +/- 47) to (226 +/- 54) mg.L-1.h (P <
0.05). CONCLUSION: This HPLC assay was sensitive and precise, and the elimination
of HF was inhibited due to CCl4 poisoning.
PMID- 10678135
TI - [Effects of acetylcholine on inositol 1,4,5-triphosphate formation in cervix
uteri myometrial cells of human].
AB - AIM: To detect inositol 1,4,5-triphosphate (IP3) formation of pregnant and
nonpregnant human myometrial cells induced by acetylcholine (ACh). METHODS: [3H]
IP3 competitive protein binding assay. RESULTS: Basal levels of IP3 in pregnant
and nonpregnant human myometrial cells were (82 +/- 9) and (96 +/- 10) nmol.g-1
(protein), respectively (n = 6). Incubated with ACh 50 mumol.L-1 for 5 min, IP3
reached the peak levels (109 +/- 11) and (122 +/- 15) nmol.g-1 (protein),
respectively (n = 6), but difference of the increments of IP3 in pregnant and
nonpregnant women was not significant. The increased IP3 induced by ACh was
inhibited by atropine (Atr) 1 mumol.L-1. CONCLUSION: The basal IP3 level in
pregnant cervix myometrial cells was higher than that in nonpregnant women. ACh
increased the IP3 formation.
PMID- 10678136
TI - Effects of ramipril on cardiac gene transcription levels of angiotensin II
receptors after myocardial infarction.
AB - AIM: To study the early changes of cardiac angiotensin (Ang) II receptor gene
transcription after myocardial infarction (MI) in rats chronically treated with
the angiotensin-converting enzyme (ACE) inhibitor ramipril. METHODS: MI was
induced by left anterior descending coronary artery ligation in rats and sham
operated rats were used as control. Rats were treated daily with ramipril (1
mg.kg-1) or water, initiated 1 wk before surgery. Quantitative RT-PCR was applied
to determine the Ang II receptors AT1, AT2 receptor gene mRNA levels in the non
infarcted myocardium. RESULTS: AT1 and AT2 mRNA levels increased time point
dependently in the cardiac septum after MI reaching a peak on d 1. There was no
significant difference of the myocardial AT1 and AT2 receptor mRNA levels between
the ramipril-treated and water-treated rats after MI. CONCLUSION: The AT1 and AT2
receptor gene transcription in the non-infarcted myocardium was associated with
the process of cardiac remodeling after MI but not affected by ACE inhibition.
PMID- 10678137
TI - Huperzine-A in capsules and tablets for treating patients with Alzheimer disease.
AB - AIM: To compare the efficacy and safety between huperzine-A (Hup) in capsules and
tablets for treating patients with Alzheimer disease (AD). METHODS: Using
multicenter, prospective, double-blind, double-mimic, parallel, positive
controlled and randomized methods, 60 patients meeting with the NINCDS-ARDRA
criteria of AD were divided into 2 equal groups. Patients in the capsule group
received 4 capsules of Hup (each contains 50 micrograms) and 4 tablets of placebo
(lactose and starch inside); while the tablet group received 4 tablets of Hup
(each contains 50 micrograms) and 4 capsules of placebo, p.o., twice a day for 60
d. All the patients were evaluated with a lot of related ranting scales, and
physiological and laboratory examination. RESULTS: There were significant
differences (P < 0.01) on all the psychological evaluations between 'before' and
'after' the 60-d trial of 2 groups, but there was no significant difference
between 2 groups by group t test (P > 0.05). The changes of oxygen free radicals
in 2 groups showed marked improvement. No severe side effect besides moderate to
mild nausea was found in both groups. CONCLUSION: There is equal efficacy and
safety between Hup in capsule and tablet for treating patients with AD, and Hup
can reduce the pathological changes of the oxygen free radicals in the plasma and
erythrocytes of patients with AD.
PMID- 10678138
TI - Leucine-2-alanine enkephalin induced delta opioid receptors internalization
expressed stably in CHO cells.
AB - AIM: To characterize the internalization of delta opioid receptors (DOR) stably
expressed in Chinese hamster ovary (CHO) cells and the role of the C-terminal in
this process. METHODS: Receptor membrane anchoring was shown by
immunofluorescence microscopy. Receptor internalization was assessed by measuring
the radioligand binding resistant to the acid-buffer wash. RESULTS: Originally,
all the wild-type (CHO-W) and C-truncated (CHO-T) DOR expressed were localized to
the membrane. Agonist [3H] leucine-2-alanine enkephalin (LAE) but not the
antagonist [3H]diprenorphine (Dip) induced rapid receptor internalization. The
internalization of C-truncated DOR in CHO-T was similar to that of the wild-type
in maximal level, but climbed up more slowly. DOR internalization was
extracellular osmolarity- and temperature-sensitive. Pertussis toxin and
universal protein kinase inhibitor staurosporine had no effect on it. CONCLUSION:
DOR internalization is an agonist and clathrin-coated pits dependent, but post
receptor cellular signal transduction independent process; moreover, the C
terminal of DOR, not engaged in membrane anchoring, affects the initialization of
DOR internalization.
PMID- 10678139
TI - Recurrent events in meta-analysis of multiple clinical trials.
AB - AIM: To study the efficacy and safety of drug or therapy with recurrent events in
meta-analysis of multiple clinical trials. METHODS: A nonparametric approach is
proposed to estimate the rates of recurrent events for meta-analysis of trials.
The method was used in meta-analysis of angiotensin-converting enzyme (ACE)
inhibitor clinical trials to analyze the relative rates and the excess rates
between ACE inhibitor and placebo treatment groups for endpoints of
hospitalizations for CHF, hospitalizations for CHF or cardiac death, and
hospitalizations for CHF or any death, respectively. RESULTS: The estimates of
those three endpoints were 69%, 74%, and 76% (P < 0.01). Compared with placebo,
ACE inhibitor reduced 30 cases of hospitalizations for CHF per 1000 person-years,
or 40 cardiac deaths or hospitalizations for CHF per 1000 person-years (P <
0.01). CONCLUSION: The method was a simple and efficient approach to conduct meta
analysis of clinical trials with recurrent events.
PMID- 10678140
TI - Effects of low-pH treatment on cAMP second messenger system regulated by
different opioid agonists.
AB - AIM: To study the mechanism of opioid agonists in regulation of cAMP second
messenger system. METHODS: Low-pH treatment was used to deplete the stimulatory G
protein (Gs) function. The effects of some opiates on adenylate cyclase were
compared between control and low-pH treatment membranes. RESULTS: In contrast to
dehydroetorphine (DHE), etorphine (Eto), morphine (Mor) and methadone (Met)
substantially increased the inhibitory effects on adenylate cyclase in membranes
prepared from naive and chronic Mor- or Met-treated NG108-15 cells by low-pH
treatment. In contrast to Mor, DHE and Eto did not result in significant decrease
in the inhibitory effects on adenylate cyclase in membranes from the cells
treated chronically with DHE or Eto. Marked rebound of adenylate cyclase was also
not observed in membranes from chronic DHE or Eto-treated cells when precipitated
with naloxone. Low-pH treatment eliminated naloxone-induced rebound of adenylate
cyclase in chronic Mor-treated cells. CONCLUSION: The difference in opiate
induced functional adaptive alteration of Gs is at least one biochemical
mechanism of developing opiate tolerance and dependence.
PMID- 10678141
TI - 5-HT1P receptor-mediated slow depolarization in neurons of guinea pig inferior
mesenteric ganglion.
AB - AIM: To study the effects of several 5-hydroxytryptamine (5-HT) receptor subtype
antagonists on 5-HT-induced depolarization and the effects of 5-HT1P receptor
agonist on the membrane potential in the neurons of guinea pig inferior
mesenteric ganglion (IMG). METHODS: Intracellular recordings were made from
neurons of the isolated guinea pig IMG. RESULTS: Cyproheptadine (5-HT1/2
antagonist 10 mumol.L-1, n = 7) and BRL 24924 (5-HT1P antagonist 10 mumol.L-1, n
= 19) reversibly suppressed 5-HT slow response; pressure ejection of MCPP (5-HT1P
agonist 10 mmol.L-1) induced a slow depolarization in most of 5-HT sensitive
neurons (10/14). CONCLUSION: 5-HT-induced slow depolarization is mediated by 5
HT1P receptor.
PMID- 10678142
TI - dl-3-n-butylphthalide improves regional cerebral blood flow after experimental
subarachnoid hemorrhage in rats.
AB - AIM: To investigate the effect of dl-3-n-butylphthalide (dl-NBP) on experimental
subarachnoid hemorrhage (SAH) in rats. METHODS: SAH was induced by injection of
autologous artery blood 0.35 mL into lateral ventricle. Regional cerebral blood
flow (rCBF) in caudate nucleus was determined by hydrogen clearance method.
RESULTS: A rapid and marked decrease in rCBF in caudate nucleus was observed 15
min after SAH and the rCBF remained at low level (about 50% pre-SAH value) within
180 min. dl-NBP (50, 100 mg.kg-1, i.g.) increased rCBF 30-180 min after the onset
of SAH without significant effect on mean artery blood pressure. dl-NBP 100 mg.kg
1 increased rCBF in caudate nucleus by 26% at 15 min and by 36% at 180 min
respectively after SAH. d-NBP but not l-NBP (10 mg.kg-1, i.p.) increased rCBF.
CONCLUSION: dl-NBP improves rCBF in caudate nucleus of rats subjected to SAH.
PMID- 10678143
TI - Dauricine suppressed CsCl-induced early afterdepolarizations and triggered
arrhythmias in rabbit heart in vivo.
AB - AIM: To study the effect of dauricine on CsCl-induced early afterdepolarizations
(EAD) and ventricular arrhythmias in rabbits. METHODS: Monophasic action
potentials (MAP) of the left ventricle of the rabbit heart in situ were recorded
with MAP recording technique. CsCl 1-2 mmol.kg-1 i.v. was used to induce EAD and
ventricular arrhythmias. RESULTS: CsCl resulted in decrease of MAP amplitude
(MAPA, P < 0.05) and prolongation of MAP duration at 90% repolarization (MAPD90,
P < 0.01), QRS, and R-R duration (P < 0.05) compared with those before CsCl in
the dauricine and control group. CsCl injection induced EAD that appeared within
about 30 s and disappeared 5-15 min thereafter. EAD always preceded ventricular
arrhythmias including ventricular premature beats and paroxysmal ventricular
tachycardia. The EAD amplitude (EADA) in the dauricine group (26% +/- 9% of MAPA)
was smaller than that in the control group (52% +/- 5% of MAPA, P < 0.05) and the
incidence of arrhythmias in dauricine group (28%) was lower than that in control
group (80%, P < 0.05). CONCLUSION: Dauricine exerted an antagonistic effect on
EAD and suppressed triggered ventricular arrhythmias by decreasing EADA.
PMID- 10678144
TI - Anti-arrhythmic effects of sophoridine and oxysophoridine.
AB - AIM: To compare the effects of oxysophoridine (Oxy) and sophoridine (Sop) on
experimental arrhythmias and myocardial physiologic properties. METHODS:
Arrhythmias were induced by drugs and myocardial ischemia. Physiologic properties
were determined on isolated heart atria. RESULTS: Oxy 500 mg.kg-1 (1/6 LD50)
decreased the incidence of ventricular arrhythmias induced by aconitine (P <
0.01), increased the threshold dose of ouabain-induced ventricular premature (VP,
P < 0.05), ventricular tachycardia (VT, P < 0.05), ventricular fibrillation (VF,
P < 0.01), and cardiac arrest, (P < 0.01). After i.v. Oxy 500 mg.kg-1 into the
rats with ligation of left anterior descending coronary artery, the total numbers
of ectopic beats were decreased (P < 0.05), the incidence of VF was lowered, and
the duration of VT was shortened (P < 0.01). Oxy 250 mg.kg-1 (1/13 LD50) i.v.
shortened the duration of arrhythmias induced by BaCl2 (P < 0.01) and delayed the
onset of arrhythmias induced by chloroform-epinephrine (P < 0.05). Oxy produced
dose-dependent positive inotropic effects in the isolated left atrial of guinea
pigs, increased the concentration of epinephrine to elicit automaticity in left
atria, decreased slightly the excitability, and prolonged the functional
refractory period. Sop produced the similar effects on arrhythmias as Oxy.
CONCLUSION: Oxy produced the similar anti-arrhythmic effects as Sop did at the
equivalent effective dose.
PMID- 10678145
TI - High glucose enhances mitogenic response to endothelin-1 in rabbit vascular
smooth muscle cells.
AB - AIM: To examine the effects of high glucose on the mitogenic response of rabbit
aortic vascular smooth muscle cells (VSMC) to endothelin-1 (ET-1). METHODS: VSMC
were cultured in normal glucose (5.5 mmol.L-1), high glucose (25 mmol.L-1) or
high osmolality (glucose 5.5 mmol.L-1, plus mannitol 19.5 mmol.L-1). DNA
synthesis was measured by [3H]thymidine incorporation. The expression of phospho
p44/42 MAPK was determined by Western blot. RESULTS: At a concentration range
from 10(-12) to 10(-8) mol.L-1, ET-1 stimulated [3H]thymidine incorporation and
phospho-p44/42 MAPK expression in VSMC in a concentration-dependent manner. From
10(-11) to 10(-8) mol.L-1, the mitogenic effect of ET-1 was higher in VSMC
cultured in high glucose at equivalent concentration than cells cultured in
normal glucose or high osmolality (P < 0.05 or P < 0.01), but no marked
difference was observed in the growth response between cells cultured under the
latter two conditions. Similarly, ET-1 increased expression of phospho-p44/42
MAPK by 60%-65% in VSMC cultured in high glucose, compared with cells in normal
glucose or high osmolality. CONCLUSION: VSMC cultured in high glucose exhibited
increased mitogenic response to ET-1, which seemed to be related to the enhanced
expression of phospho-p44/42 MAPK.
PMID- 10678146
TI - Inhibition of myocardial inward rectifier potassium current by
propylbutyldopamine.
AB - AIM: To study the effects of propylbutyldopamine (PBDA) on the inward rectifier
potassium current (Ik1). METHODS: The quasi-steady state current-voltage
relationship from the isolated guinea pig ventricular cells were measured using
whole-cell patch-clamp techniques with a slow ramp depolarization (8 mV.s-1).
RESULTS: PBDA 5, 50, and 100 mumol.L-1 concentration-dependently reduced the
inward rectifier potassium current. PBDA blocked Ik1 in guinea pig ventricular
cells. The effect of PBDA was not blocked by the selective dopamine D2-receptor
blocker, domperidone. CONCLUSION: PBDA inhibited Ik1 directly, independent of the
dopamine D2-receptor.
PMID- 10678147
TI - Prophylactic effects of tetramethyl pyrazine on mice with endotoxemia and its
relationship with platelet-activating factor.
AB - AIM: To study the prophylactic effects of tetramethyl pyrazine (TMP) on mice with
endotoxemia and its relationship with platelet-activating factor (PAF). METHODS:
LD80 of lipopolysaccharides (LPS, 15 mg.kg-1) was injected into mice (i.v.)
pretreated with TMP (i.p.). The survival rate and the level of serum PAF were
observed. The PAF induced by LPS in vivo and in vitro, and the activities of PLA2
and acetyl-CoA: lyso-PAF acetyltransferase were determined. RESULTS: TMP (10, 30,
90 mg.kg-1) obviously lowered the mortality of mice and also dose-dependently
decreased the level of serum PAF [(25.5 +/- 1.7), (13.4 +/- 3.2), (9.6 +/- 2.1)
micrograms.L-1, vs control (29.3 +/- 2.1) micrograms.L-1, P < 0.01]. TMP (0.05,
0.5, 5, 50 mumol.L-1) dose-dependently decreased the release of PAF [(12.7 +/-
1.6), (8.9 +/- 1.2), (6.9 +/- 0.8), (5.5 +/- 1.0) micrograms.L-1 vs control (11.9
+/- 1.8) micrograms.L-1, P < 0.01] from PMO cultured with LPS (5 mg.L-1), reduced
the PLA2 activity [(149.9 +/- 2.8), (117.5 +/- 2.0), (89.6 +/- 2.0), (75.0 +/-
2.8) U vs control (170.8 +/- 3.9) U, P < 0.01] and acetyl-CoA: lyso-PAF
acetyltransferase activity [PAF (9.5 +/- 0.7), (5.2 +/- 0.7), (2.9 +/- 0.3), (2.5
+/- 0.3) micrograms.g-1 (protein).min-1 vs control (11.0 +/- 0.7) micrograms.g-1
(protein).min-1, P < 0.01] of PMO lysate. CONCLUSION: TMP protected the mice with
endotoxemia from the death by decreasing the biosynthesis of PAF through the
inhibition of the activities of PLA2 and acetyl-CoA: lyso-PAF acetyl-transferase.
PMID- 10678148
TI - Dauricine inhibits redistribution of platelet membrane glycoprotein IV and
release of intracellular alpha-granule thrombospondin induced by thrombin.
AB - AIM: To study the possibility of dauricine (Dau) inhibiting redistribution of
platelet membrane glycoprotein IV (GPIV) and release of intracellular alpha
granule thrombospondin (TSP) on platelet activation. METHODS: Using the flow
cytometric assay of washed platelet to record expression of GPIV and release of
TSP induced by thrombin. RESULTS: Dau did not affect GPIV and TSP on resting
platelet membrane but inhibited redistribution of GPIV to the platelet surface
and TSP release on activated platelet. There was a marked positive correlation
between changes of GPIV and TSP (r = 0.511, P < 0.01). The inhibitory effect of
Dau appeared not to be Ca2+ concentration-dependent. CONCLUSION: Dau inhibited
redistribution of GPIV and release of intracellular alpha-granule thrombospondin
induced by thrombin.
PMID- 10678149
TI - Flutamide suppressed prostate hypertrophy in rats and mice.
AB - AIM: To study the suppressive effect of flutamide (Flu) on benign prostate
hypertrophy. METHODS: The effect of Flu 10, 25, and 50 mg.kg-1 i.g. on the
prostate was tested in orchiectomized rats with s.c. testosterone daily for 30 d
and in mice implanted with homologous strain fetal mouse urogenital sinus for 14
d. RESULTS: 1) Flu dose-dependently suppressed the weight and volume of each lobe
of the prostate to about 10%-50% of control. Also, the acini and height of
epithelial cells atrophied. The effect was more powerful than that of estradiol
(Est). 2) The weight and volume of the mouse prostate diminished in Flu-treated
groups, but the dose-response relationship was seen only in volume. In this
model, Est was better than Flu. CONCLUSION: Flu possesses the suppressive action
on benign prostate hypertrophy.
PMID- 10678150
TI - Effects of antitumor compounds isolated from Pteris semipinnata L on DNA
topoisomerases and cell cycle of HL-60 cells.
AB - AIM: To study the effect of the antitumor compounds 5F, 6F, and A from Pteris
semipinnata L on the activities of DNA topoisomerases and cell cycle of HL-60
cells, and the synergism of compound 6F in combination with genistein in vitro.
METHODS: DNA topoisomerases were isolated from HL-60 cell lines, and supercoiled
pBR322 DNA was used as substrate to determine the activities of DNA topoisomerase
I and II. Cell cycle was analyzed by flow cytometry (FCM). Cytotoxicity assay was
tested by MTT method. RESULTS: Compounds 5F, 6F, and A inhibited the activities
of DNA topoisomerase I and II. After exposure of the cells to compound 6F, an
increase in cells in the S and G2/M phases and a decrease in cells in the G0/G1
phase of the cell cycle were observed. At low concentrations (57.8 and 115.6
nmol.L-1), compound 6F enhanced the cytotoxicity against HL-60 cell line in
combination with genistein, q values were > 1.15. The enhancement times of 57.8
and 115.6 nmol.L-1 of 6F by genistein were 2.60 and 4.65, respectively.
CONCLUSION: Compounds 5F, 6F, and A inhibited the activities of DNA
topoisomerases of HL-60 cells. Compound 6F increased the number of cells in S and
G2/M phases, decreased the population of G0/G1 phase cells, and enhanced the
cytotoxicity of genistein, which had synergism with 6F in antitumor action.
PMID- 10678151
TI - Suppressive effect of kanglemycin C on T- and B-lymphocyte activation.
AB - AIM: To elucidate the suppressive effect of kanglemycin C (Kan) on lymphocyte
proliferation and T-lymphocyte subsets. METHODS: Splenocyte proliferation was
quantified with [3H]thymidine ([3H]TdR) pulsing method or 3-(4,5-dimethylthiazol
2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetery. L3T4+ and Lyt2+ T-cell
subsets were measured with fluorescence-activated cell sorter (FACS). Splenocyte
viability was assessed with trypan blue exclusion. RESULTS: Like ciclosporin
(Cic), Kan 8, 40, 80, and 400 nmol.L-1 inhibited the proliferation of 20%-80%
incubated mouse splenocytes stimulated by concanavalin A (Con A) 5 mg.L-1,
phytohemagglutinin (PHA) 5 mg.L-1, tetradecanoylphorbol acetate (TPA) 10
micrograms.L-1 + ionomycin (IM) 0.5 mg.L-1, and alloantigen (mixed lymphocyte
reaction). Kan had no toxicity to the splenocytes at the treated doses.
Suppression by Kan was declined with addition time of Kan after culture onset.
Furthermore, the suppressive effect of Kan on splenocyte proliferation stimulated
by lipopolysaccharides (LPS) 10 mg.L-1 was similar to that on splenocyte
proliferation mediated by Con A. Unlike Cic, Kan reversed the ratio of
L3T4+/Lyt2+ T-cell subsets. CONCLUSION: Kan had a suppressive action on
proliferation of T- and B-lymphocytes and had a selective effect on helper
inducer T-lymphocyte (Th) subset from Cic. Suppression by Kan was time-dependent
and not associated with toxicity of Kan.
PMID- 10678152
TI - Anti-inflammatory effects of total saponins of Panax notoginseng.
AB - AIM: To study the anti-inflammatory effects of total saponins of Panax
notoginseng (PnS). METHODS: Rat air-pouch acute inflammatory model was
established with s.c. carrageenan (Car, 25 mg.kg-1). The protein content in
exudate was measured. Micro-acid titration assay and radioimmunoassay (RIA) were
applied respectively to investigate effects of PnS on phospholipase A2 (PLA2)
activity and dinoprostone (Din) content in exudate. Fura-2 fluorescence technique
was used to determine the intracellular free calcium concentration in neutrophils
(Neu-[Ca2+]i). RESULTS: At 12 h, PnS 60-240 mg.kg-1 i.p. reduced Neu counts,
protein content [(7.7 +/- 1.3) to (4.4 +/- 1.4) g.L-1], and Din content [(1619 +/
391) to (883 +/- 268) ng.L-1]; inhibited the PLA2 activity in exudate [(248 +/-
42) to (157 +/- 35) kU.L-1] in a dose-dependent manner. PnS 60, 120, and 240
mg.kg-1 lowered the level of Neu-[Ca2+]i with the inhibitory rate of 9.1%, 33.2%,
and 39.4%, respectively. CONCLUSION: PnS has an obvious anti-inflammatory effect
and its mechanisms are related to the inhibition of the Neu-[Ca2+]i level and
PLA2 activity, and reduction of Din content.
PMID- 10678153
TI - Scavenging effect of chinonin on free radicals studied with quantum chemistry.
AB - AIM: To study whether the xanthonoid structure can enhance the ability of
chinonin to scavenge free radicals and to understand the sequence of activity of
chinonin hydroxyls. METHODS: Semiempirical quantum chemistry method AM1 was
employed to calculate delta HOF values, the differences between heat of
formations of mother molecule and its free radicals, and spin density
distribution of different states of chinonin. delta HOF values were used as
theoretical indices to measure scavenging activity of chinonin on free radicals
and effects of structure on delta HOF values were investigated. RESULTS: delta
HOF values of different phenolics were calculated to be 139.09 kJ.mol-1 (O5-H6),
141.46 kJ.mol-1 (O4-H5), 185.14 kJ.mol-1 (O2-H2) and 195.71 kJ.mol-1 (O1-H1).
Spin density distribution of free radicals were obtained as well. CONCLUSION:
Xanthonoid structure of chinonin made ring C to display high passive effect on
ring B, which reduced scavenging activity of phenolics of ring B on free
radicals. The sequence of activities of chinonin hydroxyls was O5-H6 > O4-H5 > O2
H2 > O1-H1.
PMID- 10678154
TI - Water-retention effect of suberogorgin was due to secretion of antidiuretic
hormone in rat.
AB - AIM: To study the mechanism of antidiuretic effect of suberogorgin (Sub).
METHODS: Conscious rat was given i.g. Sub 3.16 mg.kg-1 20 min after water-loaded
treatment and then urine was collected in metabolic cage. Ion excretion was
determined in atomic emission spectrometry. Urinary prostaglandin E (PGE), plasma
PGE, antidiuretic hormone (ADH), and aldosterone were measured with RIA. Sub vs
pituitrin or DOCA effects were carried out in hypophysectomized or
adrenalectomized rats. RESULTS: The urine volume and the excretions of urinary
sodium and potassium were decreased, maximally by 91%, 76%, and 86%, during the
24-h period after Sub. This antidiuretic effect possessed a progressive weakening
with time. The concentrations of urinary PGE, plasma PGE, and ADH were increased
by 25%, 212%, and 538%, respectively, but plasma aldosterone was not
significantly influenced, 2 h after Sub dosing. The response of urine-excretion
of rat to Sub was almost resisted by hypophysectomy but not by adrenalectomy.
CONCLUSION: Sub decreased the urine excretion by, at least in part, accelerating
the secretion of ADH but neither by PGE nor by aldosterone.
PMID- 10678155
TI - Effect of aerobic exercise and ginsenosides on lipid metabolism in diet-induced
hyperlipidemia mice.
AB - AIM: To study the effect of aerobic exercise and its combination with Gin
(ginsenosides from stems and leaves of ginseng) on lipid metabolism in diet
induced hyperlipidemia mice. METHODS: The mouse hyperlipidemia model was set up
by feeding high cholesterol diet. Unloaded swimming was designed to be a manner
of aerobic exercise. The effects of aerobic exercise and its combination with Gin
on total cholesterol (TC), triglycerides (TG), high density lipoprotein
cholesterol (HDL-c) in serum, malondialdehyde (MDA), and superoxide dismutase
(SOD) in liver tissue were measured; the thymus and liver were weighed. RESULTS:
(1) The mouse hyperlipidemia model was set up successfully: TC and MDA increased
(P < 0.05) but HDL-c and SOD decreased (P < 0.05); the liver weight increased and
the thymus weight reduced; fatty liver was found; (2) aerobic exercise reduced TC
but increased MDA and HDL-c in cholesterol-rich diet mice; the liver weight did
not reduce, and fatty liver did not clear up; and (3) when aerobic exercise
combined with Gin, TC and TG decreased markedly (P < 0.01), and MDA also
decreased (P < 0.05); SOD and HDL-c increased markedly (P < 0.01); the thymus
weight increased and the liver weight decreased to normal level; fatty liver
cleared up. CONCLUSION: Aerobic exercise could lower serum lipid to some extent
but could not satisfactorily regulate lipid metabolism. When combined with Gin,
aerobic exercise could better lower serum lipid, regulate lipid metabolism,
promote antioxidation, and enhance immune activity.
PMID- 10678156
TI - [Effect of endothelin-1 injected into rostral ventrolateral medulla on
cardiovascular responses in cats].
AB - AIM: To study the effect of endothelin-1 (ET-1) in the rostral ventrolateral
medulla (rVLM) on cardiovascular responses in cats. METHODS: The stereotatic
technique and microinjection method were used. RESULTS: ET-1 (4 mumol.L-1 0.5
microL) microinjected into rVLM induced mean arterial pressure (MAP) increasing
(3.7 +/- 1.3) kPa, heart rate (HR) accelerating (29 +/- 7) beats.min-1, and renal
nerve activity (RNA) intensifying 45% +/- 10%. The effects were dose-dependent.
Before and after bilateral vagotomy, there was no significant difference in the
reaction of MAP, HR, and RNA. After intravenous injection with phentolamine (5
mg.kg-1, alpha-blocker), ET-1 did not induce significant change of MAP. ET-1
raised the content of peripheral plasma argipressin (Arg) from (12.4 +/- 6.5) to
(70.3 +/- 24.2) ng.L-1 with radioimmunoassay, and showed a correlation with MAP
changes. ET-1 induced heart rhythm disorder (HRhD) in acute myocardiac ischemia,
the occur time of HRhD was (4.8 +/- 2.9) min, and the score was 4.4 +/- 1.6, and
it was significantly different from control. CONCLUSION: ET-1 microinjected into
rVLM could involve with control regulation of cardiovascular and sympathetic
nerve activity.
PMID- 10678157
TI - Action of free radical in podophyllic acid piperindyl hydrazone nitroxide radical
on its antitumor activity and toxicity.
AB - AIM: To study the action of free radical in the spin-labeled podophyllotoxin
derivative, podophyllic acid piperindyl hydrazone nitroxide radical (GP-1) on its
antitumor activity and toxicity, by comparison with those of its free radical
reduced product, podophyllic acid piperindyl hydrazone (GP-1-H). METHODS: After
treatment with GP-1 and GP-1-H, the inhibitory effects on the growth of mouse
transplantable tumors were determined; MTT formazan formation, [3H]deoxythymidine
([3H]TdR) incorporation, cell cycle progression, and mitotic index of SGC-7901 or
L1210 cells were measured; the acute toxicity and immune function of mice were
assayed. RESULTS: At doses of 1/6 and 1/12 LD50, the inhibitory rates against
Lewis lung carcinoma were 60.3% and 42.1% (GP-1), 38.9% and 10.3% (GP-1-H),
respectively; more effective antitumor activity of GP-1 against P388, HePS, and S
180 than that of GP-1-H were found. In vitro, GP-1 exhibited more powerful
inhibitory effects on the proliferation and DNA synthesis of SGC-7901 and L1210
cells than GP-1-H. GP-1 and GP-1-H arrested the L1210 cells at G2/M phase with a
corresponding decrease of the cells in G1 phase, and increased the mitotic index
of the cells; but the effects of GP-1-H were weaker than those of GP-1. After
treatment with doses of 1/4 and 1/8 LD50 for 5 d, no significant difference on
immune function of mice between GP-1 and GP-1-H was found. CONCLUSION: GP-1 had
more powerful antitumor activities than GP-1-H. The free radical in the spin
labeled podophyllotoxin derivative, GP-1, played an important role in its
antitumor activity.
PMID- 10678158
TI - Emergency department evaluation and treatment of pelvic fractures.
AB - Pelvic fractures are associated with a high morbidity and mortality rate. This
article reviews the anatomy of the pelvis, discusses fracture patterns commonly
seen in patients with an injured pelvis, and proposes a new method of classifying
pelvic fractures based on potential associated injuries. Finally, algorithms for
the management of hemodynamically stable and unstable patients with pelvic
fractures are presented.
PMID- 10678159
TI - Emergency department evaluation and treatment of hip and thigh injuries.
AB - This article reviews the clinical and diagnostic evaluation of patients with
injuries to the hip and thigh. The history and physical examination, appropriate
imaging strategies, complications and associated injuries, analgesia, treatment,
and appropriate patient disposition are emphasized.
PMID- 10678160
TI - Emergency department evaluation and treatment of knee and leg injuries.
AB - The knee is one of the most commonly injured joints in the human body, and,
largely because of athletic injuries, they are increasing in frequency in the
United States. This article provides a brief overview of knee anatomy, examines
radiographic imaging techniques and arthrocentesis of the knee, and discusses
injuries specific to the knee. An overview of leg anatomy is also presented,
along with discussions of specific fractures common to the leg.
PMID- 10678161
TI - Emergency department evaluation and treatment of ankle and foot injuries.
AB - Ankle and foot injuries are among the most common sports injuries and extremity
complaints presenting to the emergency department. Although generally benign,
some of these injuries have prolonged morbidity. This article reviews the anatomy
of the foot and ankle and examines the approach and therapy for common types of
injuries.
PMID- 10678162
TI - Soft tissue complications of orthopedic emergencies.
AB - The emergency physician encounters a diversity of potentially devastating and
disabling soft tissue maladies. This article reviews the literature and approach
to the compartment syndrome and Volkmann contracture, reflex sympathetic
dystrophy and causalgia, fracture blisters, and gas gangrene.
PMID- 10678163
TI - Systemic analgesia and sedation in managing orthopedic emergencies.
AB - Many potent agents have become available in the emergency department for
providing systemic analgesia and sedation for painful orthopedic procedures. This
article details the pharmacology and principles of systemic analgesia and
sedation, which will help the emergency physician provide maximal patient comfort
with minimal complications during painful procedures. The use of an appropriate
agent in these situations will optimize the outcome of the procedure itself and
result in greater patient satisfaction.
PMID- 10678164
TI - The activation loop of phosphatidylinositol phosphate kinases determines
signaling specificity.
AB - Phosphatidylinositol-4,5-bisphosphate plays a pivotal role in the regulation of
cell proliferation and survival, cytoskeletal reorganization, and membrane
trafficking. However, little is known about the temporal and spatial regulation
of its synthesis. Higher eukaryotic cells have the potential to use two distinct
pathways for the generation of phosphatidylinositol-4,5-bisphosphate. These
pathways require two classes of phosphatidylinositol phosphate kinases, termed
type I and type II PIP kinases. While highly related by sequence, these kinases
localize to different subcellular compartments, phosphorylate distinct
substrates, and are functionally nonredundant. Here, we show that a 20- to 25
amino acid loop spanning the catalytic site, termed the activation loop,
determines both enzymatic specificity and subcellular targeting of PIP kinases.
Therefore, the activation loop controls signaling specificity and PIP kinase
function at multiple levels.
PMID- 10678165
TI - Diaphanous-related formins bridge Rho GTPase and Src tyrosine kinase signaling.
AB - We have examined the role of the mouse Diaphanous-related formin (DRF) Rho GTPase
binding proteins, mDia1 and mDia2, in cell regulation. The DRFs are required for
cytokinesis, stress fiber formation, and transcriptional activation of the serum
response factor (SRF). 'Activated' mDia1 and mDia2 variants, lacking their GTPase
binding domains, cooperated with Rho-kinase or ROCK to form stress fibers but
independently activated SRF. Src tyrosine kinase associated and co-localized with
the DRFs in endosomes and in mid-bodies of dividing cells. Inhibition of Src also
blocked cytokinesis, SRF induction by activated DRFs, and cooperative stress
fiber formation with active ROCK. Our results show that the DRF proteins couple
Rho and Src during signaling and the regulation of actin dynamics.
PMID- 10678166
TI - Microtubule binding to Smads may regulate TGF beta activity.
AB - Smad proteins are intracellular signaling effectors of the TGF beta superfamily.
We show that endogenous Smad2, 3, and 4 bind microtubules (MTs) in several cell
lines. Binding of Smads to MTs does not require TGF beta stimulation. TGF beta
triggers dissociation from MTs, phosphorylation, and nuclear translocation of
Smad2 and 3, with consequent activation of transcription in CCL64 cells.
Destabilization of the MT network by nocodazole, colchicine, or a tubulin mutant
disrupts the complex between Smads and MTs and increases TGF beta-induced Smad2
phosphorylation and transcriptional response in CCL64 cells. These data
demonstrate that MTs may serve as a cytoplasmic sequestering network for Smads,
controlling Smad2 association with and phosphorylation by activated TGF beta
receptor I, and suggest a novel mechanism for the MT network to negatively
regulate TGF beta function.
PMID- 10678167
TI - Left-right asymmetric expression of lefty2 and nodal is induced by a signaling
pathway that includes the transcription factor FAST2.
AB - The left-right (L-R) asymmetric expression of lefty2 and nodal is controlled by a
left side-specific enhancer (ASE). The transcription factor FAST2, which can
mediate signaling by TGF beta and activin, has now been identified as a protein
that binds to a conserved sequence in ASE. These FAST2 binding sites were both
essential and sufficient for L-R asymmetric gene expression. The Fast2 gene is
bilaterally expressed when nodal and lefty2 are expressed on the left side. TGF
beta and activin can activate the ASE activity in a FAST2-dependent manner, while
Nodal can do so in the presence of an EGF-CFC protein. These results suggest that
the asymmetric expression of lefty2 and nodal is induced by a left side-specific
TGF beta-related factor, which is most likely Nodal itself.
PMID- 10678168
TI - Signal transduction by a death signal peptide: uncovering the mechanism of
bacterial killing by penicillin.
AB - The binding of bactericidal antibiotics like penicillins, cephalosporins, and
glycopeptides to their bacterial targets stops bacterial growth but does not
directly cause cell death. A second process arising from the bacteria itself is
necessary to trigger endogenous suicidal enzymes that dissolve the cell wall
during autolysis. The signal and the trigger pathway for this event are
completely unknown. Using S. pneumoniae as a model, we demonstrate that signal
transduction via the two-component system VncR/S triggers multiple death
pathways. We show that the signal sensed by VncR/S is a secreted peptide, Pep27,
that initiates the cell death program. These data depict a novel model for the
control of bacterial cell death.
PMID- 10678169
TI - Hedgehog creates a gradient of DPP activity in Drosophila wing imaginal discs.
AB - Hedgehog (HH) and Decapentaplegic (DPP) direct anteroposterior patterning in the
developing Drosophila wing by functioning as short- and long-range morphogens,
respectively. Here, we show that the activity of DPP is graded and is directly
regulated by a novel HH-dependent mechanism. DPP activity was monitored by
visualizing the activated form of Mothers against dpp (MAD), a cytoplasmic
transducer of DPP signaling. We found that activated MAD levels are highest near
the source of DPP but are unexpectedly low in the cells that express dpp. HH
induces dpp in these cells; it also attenuates their response to DPP by
downregulating expression of the DPP receptor thick veins (tkv). We suggest that
regulation of tkv by HH is a key part of the mechanism that controls the level
and distribution of DPP.
PMID- 10678170
TI - The murine SCP3 gene is required for synaptonemal complex assembly, chromosome
synapsis, and male fertility.
AB - During meiosis, the homologous chromosomes pair and recombine. An evolutionarily
conserved protein structure, the synaptonemal complex (SC), is located along the
paired meiotic chromosomes. We have studied the function of a structural
component in the axial/lateral element of the SC, the synaptonemal complex
protein 3 (SCP3). A null mutation in the SCP3 gene was generated, and we noted
that homozygous mutant males were sterile due to massive apoptotic cell death
during meiotic prophase. The SCP3-deficient male mice failed to form
axial/lateral elements and SCs, and the chromosomes in the mutant spermatocytes
did not synapse. While the absence of SCP3 affected the nuclear distribution of
DNA repair and recombination proteins (Rad51 and RPA), as well as synaptonemal
complex protein 1 (SCP1), a residual chromatin organization remained in the
mutant meiotic cells.
PMID- 10678171
TI - CDK inactivation is the only essential function of the APC/C and the mitotic exit
network proteins for origin resetting during mitosis.
AB - Passage through mitosis is required to reset replication origins for the
subsequent S phase. During mitosis, a series of biochemical reactions involving
cyclin-dependent kinases (CDKs), the anaphase promoting complex or cyclosome
(APC/C), and a mitotic exit network including Cdc5, 14, and 15 coordinates the
proper separation and segregation of sister chromatids. Here we show that cyclin
B/CDK inactivation can drive origin resetting in either early S phase or mitosis.
This origin resetting occurs efficiently in the absence of APC/C function and
mitotic exit network function. We conclude that CDK inactivation is the single
essential event in mitosis required to allow pre-RC assembly for the next cell
cycle.
PMID- 10678172
TI - Identification of two catalytic residues in RAG1 that define a single active site
within the RAG1/RAG2 protein complex.
AB - During V(D)J recombination, the RAG1 and RAG2 proteins cooperate to catalyze a
series of DNA bond breakage and strand transfer reactions. The structure,
location, and number of active sites involved in RAG-mediated catalysis have as
yet not been determined. Using protein secondary structure prediction algorithms,
we have identified a region of RAG1 with possible structural similarities to the
active site regions of transposases and retroviral integrases. Based on this
information, we have identified two aspartic acid residues in RAG1 (D600 and
D708) that function specifically in catalysis. The results support a model in
which RAG1 contains a single, divalent metal ion binding active site structurally
related to the active sites of transposases/integrases and responsible for all
catalytic functions of the RAG protein complex.
PMID- 10678173
TI - The eIF1A solution structure reveals a large RNA-binding surface important for
scanning function.
AB - The translation initiation factor eIF1A is necessary for directing the 43S
preinitiation complex from the 5' end of the mRNA to the initiation codon in a
process termed scanning. We have determined the solution structure of human
eIF1A, which reveals an oligonucleotide-binding (OB) fold and an additional
domain. NMR titration experiments showed that eIF1A binds single-stranded RNA
oligonucleotides in a site-specific, but non-sequence-specific manner, hinting at
an mRNA interaction rather than specific rRNA or tRNA binding. The RNA binding
surface extends over a large area covering the canonical OB fold binding site as
well as a groove leading to the second domain. Site-directed mutations at
multiple positions along the RNA-binding surface were defective in the ability to
properly assemble preinitiation complexes at the AUG codon in vitro.
PMID- 10678174
TI - Mammalian microsomal cytochrome P450 monooxygenase: structural adaptations for
membrane binding and functional diversity.
AB - Microsomal cytochrome P450s participate in xenobiotic detoxification,
procarcinogen activation, and steroid hormone synthesis. The first structure of a
mammalian microsomal P450 suggests that the association of P450s with the
endoplasmic reticulum involves a hydrophobic surface of the protein formed by
noncontiguous portions of the polypeptide chain. This interaction places the
entrance of the putative substrate access channel in or near the membrane and
orients the face of the protein proximal to the heme cofactor perpendicular to
the plane of the membrane for interaction with the P450 reductase. This structure
offers a template for modeling other mammalian P450s and should aid drug
discovery and the prediction of drug-drug interactions.
PMID- 10678175
TI - Mapping interactions between nuclear transport factors in living cells reveals
pathways through the nuclear pore complex.
AB - The interactions between transport receptors and proteins of the nuclear pore
complex (NPC) are fundamental to understanding nucleocytoplasmic transport. In
order to delineate the path that a particular transport receptor takes through
the NPC, we have employed fluorescence resonance energy transfer (FRET) between
enhanced cyan and yellow fluorescent proteins (ECFP, EYFP) in living cells. A
panel of yeast strains expressing functional receptor--ECFP and nucleoporin--EYFP
fusions has been analyzed with a FRET assay. With this approach, we define points
of contact in the NPC for the related importin Pse1/Kap121 and exportin Msn5.
These data demonstrate the utility of FRET in mapping dynamic protein
interactions in a genetic system. Furthermore, the data indicate that an importin
and exportin have overlapping pathways through the NPC.
PMID- 10678176
TI - Disruption of the beta-sarcoglycan gene reveals pathogenetic complexity of limb
girdle muscular dystrophy type 2E.
AB - Limb-girdle muscular dystrophy type 2E (LGMD 2E) is caused by mutations in the
beta-sarcoglycan gene, which is expressed in skeletal, cardiac, and smooth
muscle. beta-sarcoglycan-deficient (Sgcb-null) mice developed severe muscular
dystrophy and cardiomyopathy with focal areas of necrosis. The sarcoglycan
sarcospan and dystroglycan complexes were disrupted in skeletal, cardiac, and
smooth muscle membranes. epsilon-sarcoglycan was also reduced in membrane
preparations of striated and smooth muscle. Loss of the sarcoglycan-sarcospan
complex in vascular smooth muscle resulted in vascular irregularities in heart,
diaphragm, and kidneys. Further biochemical characterization suggested the
presence of a distinct epsilon-sarcoglycan complex in skeletal muscle that was
disrupted in Sgcb-null mice. Thus, perturbation of vascular function together
with disruption of the epsilon-sarcoglycan-containing complex represents a novel
mechanism in the pathogenesis of LGMD 2E.
PMID- 10678177
TI - The ves multigene family of B. bovis encodes components of rapid antigenic
variation at the infected erythrocyte surface.
AB - B. bovis, an intraerythrocytic protozoal parasite, establishes chronic infections
in cattle in part through rapid variation of the polymorphic, heterodimeric VESA1
protein on the infected erythrocyte surface and sequestration of mature
parasites. We describe the characterization of the ves1 alpha gene encoding the
VESA1a subunit, thus providing a description of a gene whose product is involved
in rapid antigenic variation in a babesial parasite. This three-exon gene, a
member of a multigene family (ves), encodes a polypeptide with no cleavable
signal sequence, a single predicted transmembrane segment, and a cysteine/lysine
rich domain. Variation appears to involve creation and modification or loss of a
novel, transcribed copy of the gene.
PMID- 10678178
TI - Rnq1: an epigenetic modifier of protein function in yeast.
AB - Two protein-based genetic elements (prions) have been identified in yeast. It is
not clear whether other prions exist, nor is it understood how one might find
them. We established criteria for searching protein databases for prion
candidates and found several. The first examined, Rnq1, exists in distinct,
heritable physical states, soluble and insoluble. The insoluble state is dominant
and transmitted between cells through the cytoplasm. When the prion-like region
of Rnq1 was substituted for the prion domain of Sup35, the protein determinant of
the prion [PSI+], the phenotypic and epigenetic behavior of [PSI+] was fully
recapitulated. These findings identity Rnq1 as a prion, demonstrate that prion
domains are modular and transferable, and establish a paradigm for identifying
and characterizing novel prions.
PMID- 10678179
TI - The crystal structure of the nuclear receptor for vitamin D bound to its natural
ligand.
AB - The action of 1 alpha, 25-dihydroxyvitamin D3 is mediated by its nuclear receptor
(VDR), a ligand-dependent transcription regulator. We report the 1.8 A resolution
crystal structure of the complex between a VDR ligand-binding domain (LBD)
construct lacking the highly variable VDR-specific insertion domain and vitamin
D. The construct exhibits the same binding affinity for vitamin D and
transactivation ability as the wild-type protein, showing that the N-terminal
part of the LBD is essential for its structural and functional integrity while
the large insertion peptide is dispensable. The structure reveals the active
conformation of the bound ligand and allows understanding of the different
binding properties of some synthetic analogs.
PMID- 10678180
TI - VASA mediates translation through interaction with a Drosophila yIF2 homolog.
AB - The Drosophila gene vasa (vas) encodes an RNA-binding protein required for
embryonic patterning and germ cell specification. In vas mutants, translation of
several germline mRNAs is reduced. Here we show that VAS interacts directly with
the Drosophila homolog of yeast translation initiation factor 2, encoded by a
novel gene, dIF2. Embryos produced by vas/+; dIF2/+ females have pattern defects
and fewer germline progenitor cells, indicating a functional interaction between
endogenous vas and dIF2 activities. Mutations in other translation initiation
factors do not enhance the vas phenotype, suggesting that dIF2 has a particular
role in germ plasm function. We conclude that VAS regulates translation of
germline mRNAs by specific interaction with dIF2, an essential factor conserved
from bacteria to humans.
PMID- 10678181
TI - Nf1 and Gmcsf interact in myeloid leukemogenesis.
AB - The NF1 tumor suppressor gene encodes neurofibromin, a GTPase-activating protein
(GAP) for p21ras (Ras). Children with NF1 are predisposed to juvenile
myelomonocytic leukemia (JMML). Some heterozygous Nf1 mutant mice develop a
similar myeloproliferative disorder (MPD), and adoptive transfer of Nf1-deficient
fetal liver cells consistently induces this MPD. Human JMML and murine Nf1
deficient cells are hypersensitive to granulocyte-macrophage colony-stimulating
factor (GM-CSF) in methylcellulose cultures. We generated hematopoietic cells
deficient in both Nf1 and Gmcsf to test whether GM-CSF is required to drive
excessive proliferation of Nf1-/- cells in vivo. Here we show that GM-CSF play a
central role in establishing and maintaining the MPD and that recipients
engrafted with Nf1-/- Gmcsf-/- hematopoietic cells are hypersensitive to
exogenous GM-CSF.
PMID- 10678182
TI - Disclosure of HIV status and its consequences.
PMID- 10678183
TI - HIV seropositivity in the Western Cape.
PMID- 10678184
TI - Chemically dependent medical practitioners--the prognosis for treatment.
PMID- 10678185
TI - Durban Malaria Conference--a short report.
PMID- 10678186
TI - Rationalizing the use of intravenous therapy in newborns.
PMID- 10678187
TI - AZT--the saga continues.
PMID- 10678188
TI - Saving mothers--report on maternal deaths in South Africa.
PMID- 10678190
TI - R100M Vincent Pallotti Hospital expansion completed
PMID- 10678189
TI - SAMA assists with development of health package for regional hospitals.
PMID- 10678192
TI - Health and human rights in post-apartheid South Africa.
PMID- 10678191
TI - Clinical progression of HIV infection in adults.
PMID- 10678193
TI - The value of electromyography and nerve conduction studies in the diagnosis of
neurological disorders.
PMID- 10678194
TI - How iron should be administered.
PMID- 10678195
TI - Benzoylserine and benzoylthreonine in propionic acidaemia treated with sodium
benzoate.
PMID- 10678196
TI - Microbiologically proven Pneumocystis carinii pneumonia (PCP) at Ga-Rankuwa
Hospital.
PMID- 10678197
TI - Growth and nutrition in South African children with cystic fibrosis.
AB - OBJECTIVES: To study nutritional status and its dietary correlates in a South
African cystic fibrosis (CF) population. DESIGN: Cross-sectional survey.
POPULATION: Thirty-eight children and adolescents attending the CF clinic at Red
Cross War Memorial Children's Hospital, Cape Town. METHODS: Standard
anthropometry and a 3-day weighted food record. RESULTS: Median percentage
expected weight for height (WFH) was 93 (interquartile range 84-101). Sixteen per
cent of patients were below the 5th percentile for height. The proportion of
patients who were malnourished (WFH less than 90) was greater among those over 10
years of age (47% v. 14.3%, chi 2 = 4.33, P = 0.037). Sixty-eight per cent of
patients consumed less than the recommended daily intake of energy. There was no
correlation between WFH and energy intake. Fat intake represented 29.6%
(interquartile range 27.5-33%) of daily energy intake. CONCLUSIONS: Young South
African children with CF are growing well despite relatively low intakes of
energy and fat. Greater attention needs to be given to overcoming malnutrition
among older children.
PMID- 10678198
TI - Pregnancy- and lactation-related folate deficiency in South Africa--a case for
folate food fortification.
AB - OBJECTIVE: Characterisation of patients presenting with megaloblastic anaemia
according to clinical, sociological, haematological and aetiological aspects of
their disease, and use of these findings to increase awareness among clinicians
and to make recommendations regarding changes in national health policy. METHODS:
This study included 104 patients presenting with megaloblastic anaemia to a large
referral hospital over a 1-year period. Data were collected and analysed in terms
of age, gender, parity, gravidity, duration of lactation, socio-economic status,
geographical origins, diet, previous haematinic treatment, clinical presentation
and haematological measurements. RESULTS: The most common cause of megaloblastic
anaemia was pernicious anaemia or probable pernicious anaemia (50%), followed by
pregnancy- and lactation-related folate deficiency (32%); of these patients, the
majority (28) presented postpartum while lactating; 5 patients were in the
immediate puerperal period of 6 weeks, and a further 16 were seen during the
first year and 7 during the second year following delivery. Only 4 patients were
pregnant, and it is noteworthy that 2 of these were still lactating at 34 weeks'
gestation. CONCLUSION: Pregnancy- and lactation-related folate deficiency up to 2
years after delivery remains a common cause of megaloblastic anaemia in South
Africa. Certain communities in rural South Africa have recently been shown to
have high incidences of both neural tube defects and folate deficiency. The
fortification of a staple food (e.g. maize or flour) with folic acid is feasible,
inexpensive, safe and likely to be beneficial. This practice should reduce the
prevalences of megaloblastic anaemia in fertile women, neural tube defects, other
congenital abnormalities, intra-uterine growth retardation, prematurity and
possibly cardiovascular disease. There is urgent need for a national policy in
this regard.
PMID- 10678199
TI - Intracranial mass lesions in HIV-positive patients--the KwaZulu/Natal experience.
Neuroscience AIDS Research Group.
AB - BACKGROUND: Neurological disease heralds the development of AIDS in 10-20% of HIV
seropositive individuals. In over half of these cases the presentation will be
that of an intracranial mass lesion (IML). In developed countries toxoplasmosis
is the most frequent cause of IML in a positive patient, followed by primary
central nervous system lymphoma. Less common causes include tuberculomas,
cryptococcomas, abscesses and gummas. As a result of these observations, the
algorithm adopted in developed countries calls for initial empirical treatment
for toxoplasmosis. Biopsy of the IML is only considered if there is no response
to treatment after 10-14 days. Whether such an algorithm would be applicable to
the local population is unknown. OBJECTIVE: We undertook a prospective study to
determine the type and frequency of IML in local HIV-seropositive patients. A
secondary objective, based on the findings, was to develop a local algorithm of
management. PATIENTS AND METHODS: Over a 17-month period HIV-seropositive
individuals with an IML were entered into the study. Biopsy or aspiration of the
lesion was performed either stereotactically or free-hand. Tissue obtained was
processed for routine and special histological studies. RESULTS: In the 38 cases
where tissue was obtained, the most frequent cause of the IML was toxoplasmosis
followed by encephalitis of obscure origin', brain abscess and
tuberculoma/mycobacterial infection. CONCLUSION: This study demonstrated that the
spectrum of IML seen locally was similar to that in developed countries. The
management protocol used elsewhere was therefore adopted for local patients.
PMID- 10678201
TI - Medical recipients of the Victoria Cross during the Anglo-Boer War, 1899-1902.
PMID- 10678200
TI - Aorto-iliac occlusive disease in the different population groups--clinical
pattern, risk profile and results of reconstruction.
AB - BACKGROUND: It has previously been accepted that atherosclerotic disease is
uncommon among blacks worldwide; however, recent studies have increasingly
reported atherosclerotic disease in this group. STUDY DESIGN: Prospective study
of hospital patients with aorto-iliac occlusive disease presenting to the
vascular service of the Durban metropolitan hospitals. The study was designed to
assess clinical pattern, risk profile and results of reconstruction in these
patients. METHODS: This is a study of 688 patients with aorto-iliac occlusive
disease managed over 9 years in Durban, with clinical pattern and risk factors
compared in the different population groups. A subgroup of 492 patients underwent
aortobifemoral bypass, providing material for comparison of the results of
reconstruction in the different population groups. RESULTS: More black patients
presented with gangrene and threatened limb, whereas whites tended to present
early with claudication. All groups had hypertension and diabetes as risk
factors. In addition, whites and Indians had ischaemic heart disease, which was
not found among blacks. Mortality was 5% (blacks 1.8%, whites 8.5%, Indians 5%).
Medium-term occlusion rates were 19% in blacks, 13% in Indians and 5% among
whites. Five-year cumulative patency rates were 92% for whites, 77% for Indians
and 74% for blacks. CONCLUSION: Whites do significantly better than blacks, who
tend to present at an advanced stage of the disease. The presence of ischaemic
heart disease among whites and Indians contributes to the higher mortality in
these groups.
PMID- 10678202
TI - Media events.
PMID- 10678203
TI - A statistical perspective on gender in medicine.
PMID- 10678204
TI - Gender bias in biomedical research.
PMID- 10678205
TI - Gender bias in medical education: twenty vignettes and recommended responses.
PMID- 10678206
TI - Gender discrimination: a health and career development problem for women
physicians.
PMID- 10678208
TI - The need for a national cancer control strategy in New Zealand.
PMID- 10678207
TI - Gender bias in a peer-reviewed medical journal.
PMID- 10678209
TI - Socio-demographic characteristics of New Zealand smokers: results from the 1996
census.
AB - AIMS: To examine the key socio-demographic characteristics of adult smokers in
New Zealand based on 1996 census data. METHODS: Data were obtained from the 1996
Census of Populations and Dwellings on smoking status and key socio-demographic
variables. Age standardised smoking prevalence rates were calculated. RESULTS: Of
the New Zealand population aged 15 years and over, 23.7% reported that they were
regular smokers. Maori have the highest smoking prevalence in New Zealand (40.5%)
and the peak rate is 55% among young Maori women aged 25-29 years. Pacific Island
people, particularly males, have higher smoking rates than Europeans, while among
Asians, the rate for males is three to four times the rate for females. People
with no qualifications, who are unemployed or earning less than $30,000 per year,
and women with high parities also have relatively high smoking prevalence rates.
CONCLUSION: The smoking rates of New Zealand population groups are highly
heterogeneous and there is substantial scope for focusing tobacco control
interventions on those groups with the highest prevalence.
PMID- 10678210
TI - How many pregnant women in Christchurch are using folic acid supplements in early
pregnancy?
AB - AIMS: To determine the proportion of pregnant women in Christchurch using folic
acid supplements in early pregnancy. To evaluate the level of current knowledge
relating to folic acid amongst pregnant women. To determine the main sources from
which this information was gained. METHODS: A short questionnaire was
administered to 191 pregnant women in Christchurch during antenatal visits with
their lead maternity carer. The survey contained questions relating to knowledge
about folic acid and use together with sources of information regarding folic
acid. Obstetric and demographic details were also collected. RESULTS: The
response rate was 95.5%. Ninety-one per cent (174/191) of participants had heard
of folic acid and, of these, 63% knew that folic acid reduces the risk of spina
bifida. Of the 191 participants in the study, 118(62%) took folic acid
supplements at some stage of their pregnancy, however, only 33(17%) had taken
periconceptual folic acid supplements. Of the 44% of all women in the study with
a planned pregnancy, only 35% had taken folic acid supplements periconceptually.
Of those women with an unplanned pregnancy (55%), only 2.8% had taken a folic
acid supplement periconceptually. The main sources of advice for women relating
to folic acid were general practitioners (48%) or media advertising, either in
the form of a magazine, or health pamphlet or television promotion (20%).
CONCLUSIONS: The results of this study indicate that the level of knowledge
amongst women of child-bearing age relating to folic acid is relatively high
compared with other countries. Despite this high level of knowledge, only a small
percentage of women are actually consuming a folic acid supplement during the
recommended periconceptual period due in part to the high proportion of unplanned
pregnancies. These results emphasize the need for an effective public health
strategy to ensure that all women of child-bearing age have access to an adequate
folic acid intake.
PMID- 10678211
TI - Outcomes of transrectal ultrasound scan of the prostate with sector biopsies for
323 New Zealand men with suspicion of prostate cancer.
AB - AIMS: To assess the results and clinical outcomes of the first four years of
transrectal ultrasound scanning (TRUS) with sector biopsies of the prostate, as
the definitive second-line investigation for men with suspicion of prostate
cancer, including comparability with subsequent information from histology of
surgical specimens. METHODS: Information was collated from the author's ongoing
surgical audit. TRUS and sector biopsies were carried out as a rooms procedure
using a Toshiba Sono-Layer SSA-270A ultrasound machine with a PVL 725 RT
transrectal probe and biopsy guide. Six or eight sector biopsies were taken with
a Manan biopsy gun using 18 French gauge biopsy needles. Prophylactic
ciprofloxacin and tinidazole were administered. Men with suspicion of prostate
specific antigen assay or digital rectal examination were considered for the
investigation, especially if they were candidates for potentially curative
treatments. RESULTS: Of 330 TRUS procedures performed on 323 men, 328 were done
in rooms under local anaesthetic. The only significant complication was a
transient bacteraemia in one patient not taking the antibiotics. Twenty men had
prostate intraepithelial neoplasia or atypia, and 94 (29%) had cancer, of whom 24
(25%) had evidence of metastases. Curative treatment by radical prostatectomy or
radiotherapy was attempted in 62 men (66%) and 28 are being managed by
surveillance only. Comparisons with subsequent radical prostatectomy in 44 men
showed that if only one TRUS biopsy core was involved with cancer (15 men),
surgical margins were clear. For those with more cores involved (29 men), one
third (9 men) had positive margins or capsular perforation. The Gleason Score was
different, more often higher, for 29 men by histology at radical prostatectomy
compared to TRUS. Twenty-eight men had a subsequent transurethral resection of
the prostate of which the histology resulted in management changes for ten of the
28, including three who were placed on surveillance and seven who underwent
radical prostatectomy. CONCLUSIONS: TRUS and sector biopsy is a tolerable rooms
procedure for men with suspician of prostate cancer. Complications are rare if
prophylactic antibiotics are taken. The procedure provides information of
sufficient quality to advise patients further. No defects in specificity were
detected. Defects in sensitivity were demonstrated by comparison with later
histology following transurethral resection. Therefore, men with benign results
at TRUS need ongoing follow-up. TRUS histology tends to underestimate the extent
of cancer present as determined by subsequent radical prostatectomy histology.
When used with prostate-specific antigen and digital rectal examination, TRUS and
sector biopsy is capable of detecting prostate cancer before it has metastasized,
more reliably than if symptoms are awaited before diagnosis is attempted. It may
also recognize forms of cancer of apparent low clinical significance which can be
managed by surveillance.
PMID- 10678212
TI - For whom is the Caesarean section rate high?
AB - AIM: To define a method for examining and comparing Caesarean section rates.
METHODS: Data on Caesarean section rates at National Women's Hospital for 1997
were analysed by two methods which adjust Caesarean section rates according to
casemix: 1. standard nulliparae and 2. grouping women by factors influencing
Caesarean section rates. RESULTS: The Caesarean section rate in New Zealand is
rising and National Women's Hospital had a Caesarean section rate of 22.3% in
1997. The instrumental vaginal delivery rate was 13.1%. Our 1997 data were
analysed for casemix -- standard nulliparae and dividing women into six distinct
groups. The Caesarean section rate for standard nulliparae was 19.2%. Nulliparae
had an increased induction of labour rate compared to multiparae (29.1% versus
22.9%, p < 0.001). The Caesarean section rate was increased in association with
induction of labour for nulipare (26.0% versus 13.1%, p < 0.001), multiparae with
unscarred uteri, (5.4% versus 2.5%, p < 0.001) and primiparae with previous
caesareans (36.8% versus 30.4%, p = 0.02) CONCLUSION: We suggest our second
method of grouping women by the most important factors influencing intervention
rates should be used by obstetric units for benchmarking and internal audit
purposes.
PMID- 10678213
TI - Attention is needed to the high prevalence of vitamin D deficiency in our older
population.
AB - The aim of this study was to assess the prevalence of vitamin D deficiency in
females residing in one large, aged-care facility in Auckland. Thirty-nine
residents, most of whom were able to go outdoors without assistance, were tested
for midwinter 25-hydroxyvitamin D, and, of these, 36 were tested again in
midsummer. The prevalence of frank hypovitaminosis (<10 microg/L) was found to be
49% in midwinter and 33% in midsummer. The vitamin D status of such at-risk
individuals could be normalised either by 15-30 minutes of daily sun exposure or,
alternatively, a programme of supplementation.
PMID- 10678214
TI - Patient enrollment with co-payments: implications for patient choice in general
practice.
PMID- 10678215
TI - Antibiotics in otitis media.
PMID- 10678216
TI - Home birth outcome: a personal series.
PMID- 10678217
TI - Screening for prothrombotic diathesis in family planning clinics.
PMID- 10678218
TI - Medical Council and penalties for misconduct.
PMID- 10678219
TI - Ethics of ACC continued.
PMID- 10678220
TI - Mycobacterium xenopi lung infection.
PMID- 10678221
TI - Measuring health-related quality of life using the SF-36.
PMID- 10678222
TI - Medical practitioner guilty of misconduct.
PMID- 10678223
TI - Cardiac allograft vasculopathy: the green lane hospital experience 1987-1998.
AB - AIMS: To determine the prevalence of cardiac allograft vasculopathy in heart
transplant recipients at Green Lane Hospital and to examine potential risk
factors for vasculopathy. METHODS: We retrospectively reviewed the coronary
angiograms of all cardiac transplant recipients. Angiography was usually
performed one, two and five years after operation. The diagnosis of allograft
vasculopathy was made if there was any evidence of coronary artery disease.
Patients' medical records were reviewed for potential risk factors. RESULTS:
Ninety-one patients underwent cardiac transplantation between December 1987 and
March 1998. One year survival was 87%. Angiographic evidence of coronary disease
was present in 30 patients and in three patients coronary lesions were first
identified at post mortem. Vasculopathy was present in 25%, 35% and 61% of
patients at one two and five years following transplant. Donor-acquired lesions
could not be excluded as few patients had immediate postoperative angiograms for
comparison. Five late deaths have been due to vasculopathy. Recipient age, race,
donor age and ischaemic time were similar for those with and without
vasculopathy. Frequency or severity of acute rejection episodes, cytomegalovirus
infection, lipid profiles, diabetes and hypertension were not significantly
different in patients with vasculopathy. CONCLUSION: Cardiac allograft
vasculopathy is a common finding after heart transplantation. No definite risk
factors were identified in this patient group.
PMID- 10678224
TI - Postoperative adhesive small bowel obstruction: the resources impacts.
AB - AIM: To assess the resource implications of managing small bowel obstruction,
which is common and has diverse causes and outcomes. METHOD: A retrospective
study of 332 patients documented to have postoperative, adhesive small bowel
obstruction, from 1988 to 1996, was carried out. Complications and resources used
were recorded and costs were determined. Results. There were 207 females and 125
males, with a median age of 63 years. There were 374 hospital admissions, in 121
(32.4%) of which no surgical operation was performed. Patients had a median
hospital stay of eight days. The overall median cost for a patient who had no
operation was NZ$1 039 (minimum $94, maximum $13 262), compared to NZ$7 630
(minimum $2 038, maximum $135 173) for a patient who had an operation.
Postoperative adhesive small bowel obstruction accounted for 1.3% of all
admissions, 59.2% of all cases of bowel obstruction, 65.2% of all admissions with
small bowel conditions, 73.5% of laparotomies for bowel obstruction and 4.1% of
all laparotomies. Sixty-eight patients (20.5%) developed a total of 102
complications and there were eight deaths (2.4%). CONCLUSION: Postoperative
adhesive small bowel obstruction is a common condition, which is associated with
a substantial morbidity and workload. The treatment of these conditions has
significant health care costs. Most are emergencies and the costs of their
management are very variable.
PMID- 10678225
TI - Susceptibility of anaerobic bacteria in Auckland: 1991-1996.
AB - AIM: To determine the antimicrobial susceptibility of local anaerobic bacteria.
METHOD: The antimicrobial susceptibility of 357 obligate anaerobes collected
between 1991 and 1997 was determined by a standard agar dilution method. Isolates
tested included Bacteroides spp. 131, Fusobacterium spp. 12, Prevotella spp. 13,
Veillonella spp. 5, Clostridium perfringens 27, other Clostridium spp. 29,
Propionibacterium spp. 57, Actinomyces spp. 7, other non-sporing gram-positive
bacilli 28 and Peptostreptococcus spp. 48. Ten antimicrobials were tested:
penicillin, amoxycillin/ clavulanic acid, pipercillin/tazobactam, ceftriaxone,
cefoxitin, cefotetan, imipenem, meropenem, clindamycin and metronidazole.
RESULTS: Imipenem, pipercillin/tazobactam, meropenem and amoxycillin/clavulanic
acid were active against virtually all anaerobes tested. Metronidazole was active
against all anaerobic gram-negative bacteria and Clostridium spp., but had
variable activity against other anaerobes. Cefoxitin was the most active
cephalosporin against Bacteroides spp., with 76%, 64% and 15% of Bacteroides spp.
being susceptible to cefoxitin, cefotetan and ceftriaxone, respectively.
Penicillin had poor activity against anaerobic gram negative bacilli. Actinomyces
and Propionibacterium spp. were susceptible to all antimicrobials tested except
metronidazole. Variable results were obtained with other antimicrobial-organism
combinations. Comparison of results with data from a previously published survey
showed little change in susceptibility except for increased resistance of
Bacteroides fragilis to ceftriaxone and Clostridium species (not C perfringens)
to clindamycin. CONCLUSION: Our results update the local susceptibility profile
of anaerobic bacteria and may be considered when choosing an antimicrobial agent
for prophylaxis or treatment of anaerobic infections.
PMID- 10678226
TI - The health of elderly residents in long term care institutions in New Zealand.
AB - AIMS: To estimate the morbidity of residents in long term care institutions in
Hamilton, New Zealand and examine the prescribing practice within these
institutions. METHODS: One hundred residents were selected at random from the
total population of residents in long-term institutions in Hamilton. Residents
were examined by a physician to arrive at ICD-9 diagnoses and details were
recorded about prescribing practice. RESULTS: Eighty residents were examined. Of
these, 73% had dementia. Forty-five per cent were diagnosed as having heart
failure and 44% cerebrovascular disease. The most common previously undiagnosed
disorder was postural hypotension (24%). Residents were prescribed an average of
4.5 non-psychotropic medications. Seventy-seven per cent of residents were
prescribed three or more medications. CONCLUSION: Elderly residents in long term
care institutions in Hamilton have complex health care needs which offer
particular challenges for doctors and other health care workers. Regular health
care reviews could lead to more accurate diagnosis and better prescribing
practice.
PMID- 10678227
TI - Death due to unrecognised myocardial infarction causing left ventricular rupture:
can we improve the diagnostic rate?
AB - AIM: To investigate the clinical presentations of ruptured myocardial infarction,
where the initial diagnosis of myocardial infarction was missed, to enhance the
diagnostic rate of primary care physicians. METHODS: We studied 67 cases of
myocardial infarction, terminating with left ventricular rupture, between January
1988 and December 1996. The study was restricted to sudden death where, at
coroner-directed autopsy, a ruptured myocardial infarction was determined as the
cause of death. It was also restricted to patients who consulted a doctor within
the two weeks prior to death. The report made to the coroner by attending police
and the autopsy report was studied, and the requisite data were abstracted.
RESULTS: Half of our study group did not present with chest pain. Of the atypical
presentations: 15/67 cases (22%) were from referred pain (neck, arm, abdomen or
back), 12/ 67 patients presented with "flu-like illness" (18%), 4/67 cases had
respiratory presentations (cough or shortness of breath) (6%) and 2/67 falls
(3%). Of those with chest pain, 16/34 (47%) were diagnosed or referred and 2/15
infarcts with atypical or referred pain were diagnosed. None of those presenting
with "flu like illness" or respiratory symptoms was diagnosed or referred.
CONCLUSION: Fifty per cent of our patients had "silent" myocardial infarcts. A
large proportion of this group complained of a flu-like illness, which is
currently not considered a presentation of this disease. Patients at higher risk
of a myocardial infarct, should be treated with a high index of suspicion when
unwell, especially when complaining of a flu-like illness. Pathologically,
posterior and lateral infarcts accounted for over half the cases.
PMID- 10678228
TI - Screening for hepatitis B carriers: evidence and policy development in New
Zealand.
PMID- 10678229
TI - PHARMAC: at what cost?
PMID- 10678230
TI - PHARMAC and good science?
PMID- 10678231
TI - PHARMAC complicates treatment of glaucoma.
PMID- 10678232
TI - Measuring health-related quality of life.
PMID- 10678233
TI - Systemic inflammatory response syndrome (SIRS) from acute polyarticular gout.
PMID- 10678234
TI - Diabetes complication screening.
PMID- 10678235
TI - A changing world- the need and value of home visits.
PMID- 10678236
TI - Do referring doctors and rheumatologists agree?
PMID- 10678237
TI - Oral contraceptives and venous thromboembolism.
PMID- 10678238
TI - Simple technology use in patient care at a distance.
PMID- 10678239
TI - Radiologist found guilty of misconduct.
PMID- 10678240
TI - Hyperhomocysteinaemia: a risk factor for vascular disease.
PMID- 10678241
TI - Homocysteine levels in healthy New Zealanders and those with vascular disease.
AB - AIMS: Levels of plasma homocysteine (tHcy) have been shown to vary between
populations. The aim of the present study was to determine tHcy levels in a New
Zealand population to facilitate interpretation of international reference
ranges. METHODS: Fasting tHcy levels were determined in 431 volunteer men and
women, aged between 17 and 83 years, from the greater Otago region. Subjects with
self-reported incidences of vascular disease (n=138) were compared with healthy
control subjects (n=293). RESULTS: Mean (SD) fasting tHcy level of the entire
population was 8.3(3.5) micromol/L and men had significantly higher levels than
women (9.0(3.4) and 7.8(3.5) micromol/L, respectively, p<0.05). Levels increased
significantly with increasing age (0.5 micromol/L for every ten years). There was
a small but non-significant difference in tHcy levels between subjects with and
without vascular disease (difference after excluding two outliers and adjusting
for age and gender; 0.63, 95% CI, -0.03,1.29). tHcy levels were not significantly
correlated with lipid or lipoprotein levels. CONCLUSION: Levels of tHcy in a
group of volunteers from the greater Otago region were similar to those reported
in other populations at high risk of cardiovascular disease. Reference ranges
derived from these populations would appear to be applicable for New Zealanders.
tHcy measurements should be made when assessing individuals at high risk of
vascular disease and intervention strategies considered.
PMID- 10678242
TI - Methadone maintenance treatment: outcomes from the Otago methadone programme.
AB - AIM: To provide information on methadone treatment outcomes for opiate-dependent
individuals. METHODS: Questionnaires and random urine tests were completed for
112 Otago clients comparing outcomes before and during methadone maintenance
treatment. RESULTS: Treatment retention rates were high, with 86% of clients
remaining on the programme six months or more. The number of clients on benefits
reduced by almost 30% during treatment, with employment rates doubling from 19%
to 40% (including attendance at educational programmes). For the 89 clients
injecting opiates daily at initial presentation, 64% reported no opiate use in
the three months prior to review. Of the remaining 36%, opiate use reduced
significantly. Rates of sharing injecting equipment reduced by almost 90%. Almost
50% of cannabis users reduced their use from daily to less than daily use.
Clients reporting no current use of illicit benzodiazepines increased by 85%.
Heavy binge drinking weekly or more reduced by almost 75%. Use of other illicit
drugs reduced by almost 90%. Drug-related convictions reduced by almost 60%,
while accidental drug overdoses reduced by over 90%. CONCLUSION: The widespread
benefits of methadone maintenance treatment demonstrated underline the importance
of making quality methadone programmes readily accessible within the health
system. Currently, there are long waiting lists and many individuals cannot gain
access to active treatment. We believe the health system urgently needs to look
at expanding existing services and/or establishing private methadone clinics
similar to those in New South Wales.
PMID- 10678243
TI - Ophthalmomyiasis and nasal myiasis in New Zealand: a case series.
AB - We report three cases of ophthalmomyiasis in New Zealand, due to the larvae of
Oestrus ovis. All three patients reported eye injury caused by a fly. The larvae
were removed from the conjunctival sac without difficulty under local
anaesthesia. Presenting ocular symptoms of foreign body sensation, irritation,
redness and photophobia all resolved swiftly. Topical antibiotic and steroid eye
drops were administered. All three patients also developed nasal symptoms such as
sneezing, nasal discharge and epistaxis. Otolaryngology follow-up demonstrated
nasal myiasis in two patients which was treated with nasal decongestants. In
addition, all three patients were treated with ivermectin (Mectizan).
PMID- 10678244
TI - Cervical pregnancy managed without hysterectomy.
PMID- 10678245
TI - Excessive use of inhaled salbutamol: the potential benefits of dose-reduction. A
case report.
AB - Inhaled, short-acting, beta-agonist medications are widely used in the treatment
of asthma. It is recommended in current asthma management guidelines that these
medications should only be used "as required" for relief of asthma symptoms.
Despite this, there are still a number of asthmatic patients who are using
excessive amounts. In occasional patients this may be detrimental to the control
of asthma. We report the case of a 43-year-old, steroid-dependent asthmatic, with
unstable asthma, using salbutamol up to 30 times a day. Following reduction of
her beta-agonist use she had a dramatic improvement in her asthma control and was
able to successfully stop her oral steroids.
PMID- 10678246
TI - Breathlessness in older people.
AB - Breathlessness in the elderly is a common clinical problem but should not be
considered an inevitable consequence of the aging process. Because of the diverse
causes and the possibility of more than one underlying mechanism, the approach to
the breathless patient needs to be comprehensive with investigations guided by
specific clinical questions. Once the underlying reversible factors have been
identified and treated as far as practicable, management of the chronically
breathless patient is based on symptom relief, exercise conditioning,
optimisation of breathing patterns and patient education. Interventions should be
objectively evaluated using symptom scores or a measure of exercise tolerance
rather than a physiological measure alone. As there is the potential for harm
(including cost), treatments offering no benefit should be promptly withdrawn.
PMID- 10678247
TI - Immunisation coverage in New Zealand.
PMID- 10678248
TI - Childhood immunisation in Rotorua.
PMID- 10678249
TI - Third generation oral contraceptives and the risk of pulmonary embolism.
PMID- 10678250
TI - Alternative therapies and "standard medicines".
PMID- 10678251
TI - General practitioner found guilty of professional misconduct.
PMID- 10678252
TI - Obesity research and the new century.
PMID- 10678253
TI - Use of tape-recorded food records in assessing children's dietary intake.
AB - BACKGROUND: Dietary assessment among children is particularly problematic when
techniques are dependent on memory skills or advanced cognitive development.
OBJECTIVE: The current study explored the use of self-report by tape recorders to
document children's dietary intake immediately upon consumption, and compared
this method with the traditional, interviewer-guided recall technique. In
addition, the influence of body fatness and sociodemographic characteristics on
the accuracy of recall and tape-recorded food records was determined. RESEARCH
METHODS AND PROCEDURES: The sample included 30 black and white children aged 6.5
to 11.6 years (x = 9.5). Energy intake (EI), measured by six 24-hour food records
(three for each method), was compared with total energy expenditure calculated by
the doubly labeled water technique. Paired t tests, correlation analyses, and
multiple regression analyses were performed. RESULTS: The analyses revealed poor
validity of the tape recorder method (x misreporting score = -1.13+/-2.62 MJ/day,
r for total energy expenditure and EI = -0.06, p = 0.74). Estimates of EI
differed significantly between the tape recorder and recall methods (p<0.01). The
traditional recall method was confirmed as a valid estimate of energy intake (x
misreporting score = 0.04+/-2.38 MJ/day), although demonstrating a modest
correlation with TEE (r = 0.32, p = 0.08). Although no significant predictors of
misreporting using the recall method were identified in the multivariate
analyses, older children and children with higher adiposity were more likely to
misreport using the tape recorder method. DISCUSSION: The results suggest that
the use of the tape recorder for estimating EI does not result in accurate
assessments among children, although this technique may be useful for specific
subgroups (i.e., younger and leaner children).
PMID- 10678254
TI - Heart rate variability in obese children: relations to total body and visceral
adiposity, and changes with physical training and detraining.
AB - OBJECTIVE: Heart rate variability provides non-invasive information about cardiac
parasympathetic activity (PSA). We determined in obese children: (1) relations of
baseline PSA to body composition and hemodynamics; (2) effects of physical
training (PT) and cessation of PT; and (3) which factors explained individual
differences in responsivity of PSA to the PT. RESEARCH METHODS AND PROCEDURES:
The root mean square of successive differences (RMSSD) was the index of PSA.
Obese children (n = 79) were randomly assigned to groups that participated in PT
during the first or second 4-month periods of the study. RESULTS: Baseline RMSSD
was significantly (p<0.05) associated with lower levels of: fat mass, fat-free
mass, subcutaneous abdominal adipose tissue, resting heart rate (HR), resting
systolic blood pressure, and exercise HR. Stepwise multiple regression produced a
final model (R2 = 0.36) that included only resting HR. The analysis of changes
over the three time points of the study found a significant (p = 0.026) time by
group interaction, such that RMSSD increased during periods of PT and decreased
following cessation of PT. Greater individual increases in response to the PT
(p<0.05) were seen in those who had lower pre-PT RMSSD levels, showed the
greatest decreases in resting HR, and increased most in vigorous physical
activity. The final regression model retained only the change in resting HR as a
significant predictor of the changes in the RMSSD (R2 = 0.23). DISCUSSION:
Regular exercise that improved fitness and body composition had a favorable
effect on PSA in obese children.
PMID- 10678255
TI - Abnormal signal-averaged electrocardiogram (SAECG) in obesity.
AB - OBJECTIVE: The occurrence of small high-frequency electrocardiogram (ECG)
potentials (1 to 20 microV) seen at the end of the QRS complex and into the ST
segment have been correlated with increased risk for ventricular arrhythmias and
sudden cardiac death. Computer-assisted analysis of these "late potentials" by
signal-averaged electrocardiography (SAECG) has been studied and utilized to
predict the likelihood of ventricular arrhythmias in various clinical states.
Obesity is associated with significant cardiovascular morbidity and sudden death.
Ventricular arrhythmias are postulated causes. We studied the occurrence of late
potentials in a randomly selected group of obese patients and healthy volunteers.
RESEARCH METHODS AND PROCEDURES: We performed SAECG on 105 subjects. Of these, 62
were obese ambulatory patients with body mass index (BMI) of >30 kg/m2, whereas
43 were healthy asymptomatic volunteers with a BMI of <30 kg/m2. Patients with a
history of clinical heart disease and pulmonary disease, electrolyte
abnormalities, recent hospitalizations, or abnormal screening ECG or taking
medications known to alter the QRS interval were excluded. At least 250 beats
were analyzed with a noise level of <0.50 microV. Criteria of a late potential
include QRS duration >114 ms, high-frequency low amplitude >38 ms, and root-mean
square voltage <20 microV. Patients were divided into four subgroups based on BMI
values. The prevalence of SAECG abnormalities in each BMI subgroup was studied.
We utilized multiple logistic regression analysis to study the effect of obesity,
hypertension, and diabetes mellitus on abnormal SAECG results. RESULTS: Compared
to age- and sex-matched healthy volunteers with BMI of <30 kg/m2, obese patients
with BMI of >30 kg/m2 had significantly more abnormalities on SAECG (4.6% vs.
55%). In the obese group, the prevalence and number of abnormalities increased
with increase in BMI (35% in the BMI 31 to 40 kg/m2 subgroup, 86% in the BMI 41
to 50 kg/m2 subgroup, and 100% in patients with BMI of >50 kg/m2). Multiple
logistic regression analysis shows that BMI is an independent predictor variable
of abnormal SAECG results in obese patients (n = 62) with BMI of >30 kg/m2 as
well as in all study subjects (n = 105). BMI also predicts abnormality of each
abnormal SAECG criterion in both obese and all subjects. Hypertension was found
to influence the QRS duration alone in obese and all subjects. DISCUSSION:
Obesity is associated with increased occurrence of abnormal SAECG results. These
abnormalities are found both in obese patients with and without hypertension
and/or diabetes. Obesity is an independent predictor variable of abnormal SAECG
results. A history of hypertension predicts abnormality of QRS duration only.
PMID- 10678256
TI - Leptin responses to weight loss in postmenopausal women: relationship to sex
hormone binding globulin and visceral obesity.
AB - OBJECTIVE: Leptin concentrations increase with obesity and tend to decrease with
weight loss. However, there is large variation in the response of serum leptin
levels to decreases in body weight. This study examines which endocrine and body
composition factors are related to changes in leptin concentrations following
weight loss in obese, postmenopausal women. RESEARCH METHODS AND PROCEDURES: Body
composition (DXA), visceral obesity (computed tomography), leptin, cortisol,
insulin, and sex hormone-binding globulin (SHBG) concentrations were measured in
54 obese (body mass index [BMI] = 32.0+/-4.5 kg/m2; mean +/- SD), women (60+/-6
years) before and after a 6-month hypocaloric diet (250 to 350 kcal/day deficit).
RESULTS: Body weight decreased by 5.8+/-3.4 kg (7.1%) and leptin levels decreased
by 6.6+/-11.9 ng/mL (14.5%) after the 6-month treatment. Insulin levels decreased
10% (p< 0.05), but mean SHBG and cortisol levels did not change significantly.
Relative changes in leptin with weight loss correlated positively with relative
changes in body weight (r = 0.50, p<0.0001), fat mass (r = 0.38, p<0.01),
subcutaneous fat area (r = 0.52, p<0.0001), and with baseline values of SHBG (r =
0.38, p<0.01) and baseline intra-abdominal fat area (r = -0.27, p<0.06). Stepwise
multiple regression analysis showed that baseline SHBG levels (r2 = 0.24,
p<0.01), relative changes in body weight (cumulative r2 = 0.40, p<0.05), and
baseline intra-abdominal fat area (cumulative r2 = 0.48, p<0.05) were the only
independent predictors of the relative change in leptin, accounting for 48% of
the variance. DISCUSSION: These results suggest that obese, postmenopausal women
with a lower initial SHBG and more visceral obesity have a greater decrease in
leptin with weight loss, independent of the amount of weight lost.
PMID- 10678257
TI - Usefulness of anthropometry and DXA in predicting intra-abdominal fat in obese
men and women.
AB - OBJECTIVE: To investigate the usefulness of anthropometry and DXA in predicting
intra-abdominal fat (IAF) in obese men and women. RESEARCH METHODS AND
PROCEDURES: Observational, cross sectional study of 22 women and 18 men with a
body mass index of 30 or above. IAF from 20 cm above and 10 cm below the L4 to L5
intervertebral disc was measured by magnetic resonance imaging (MRI) as a
reference method. Central abdominal fat was measured from the upper border of L2
to the lower border of L4 by DXA. Waist and hip circumferences were also
measured. RESULTS: In obese women DXA, waist circumference and waist-hip ratio
were equally well correlated with IAF (r = 0.74, 0.75, and 0.70, respectively).
In obese men DXA was moderately correlated with IAF measured by MRI (r = 0.46),
whereas waist circumference and waist-hip ratio were not significantly correlated
with IAF. DISCUSSION: The prediction of IAF in obese subjects was highly
dependent on sex more than in non-obese persons. Anthropometry and DXA were
equally useful in obese women, whereas anthropometry had no predictive power and
DXA was the only acceptable predictor of IAF in obese men.
PMID- 10678258
TI - Diabetes disease stage predicts weight loss outcomes with long-term appetite
suppressants.
AB - OBJECTIVES: Characterize degree of weight loss with stage of diabetes and
describe its effect on cardiovascular disease risk factors in obese patients with
and without diabetes. RESEARCH METHODS AND PROCEDURES: Retrospective cohort
analysis from patients participating in a long-term weight management protocol
using diet, exercise, behavioral modification, and appetite-suppressant therapy.
Patient groups, with (n = 19) and without diabetes (n = 19) were matched for age,
gender, and weight before weight loss therapy. The effect of 12 months of therapy
on weight, blood pressure, glycemic control, lipid profile, and medication
requirements were tested. Additionally, patients were grouped or staged based
upon therapy required for control of diabetes at the beginning of weight loss
intervention. Analysis of covariance described relationships between diabetes
disease stage and weight loss at 12 months. RESULTS: Nondiabetic patients had
greater mean reduction in BMI than the diabetic group (7.98 kg/m2 vs. 4.77 kg/m2,
p<0.01). A significant linear trend (p<0.001) for decreasing weight loss with
stage of diabetes was observed. Blood pressure, lipid profile, and glycemia
improved significantly. The average daily glyburide-equivalent dose decreased
from 9.4 to 3.0 mg (p<0.01). DISCUSSION: Patients with diabetes lost less weight
than similarly obese patients without diabetes. Regardless of differential weight
loss between groups, cardiovascular disease risk factors improved. Hypoglycemic
medication requirements decreased with weight loss therapy. A predictive
relationship may exist between diabetes disease stage before weight loss therapy
and future weight loss potential.
PMID- 10678259
TI - Weight loss, weight maintenance, and improved cardiovascular risk factors after 2
years treatment with orlistat for obesity. European Orlistat Obesity Study Group.
AB - OBJECTIVE: To determine the effect of orlistat, a new lipase inhibitor, on long
term weight loss, to determine the extent to which orlistat treatment minimizes
weight regain in a second year of treatment, and to assess the effects of
orlistat on obesity-related risk factors. RESEARCH METHODS AND PROCEDURES: This
was a 2-year, multicenter, randomized, double-blind, placebo-controlled study.
Obese patients (body mass index 28 to 43 kg/m2) were randomized to placebo or
orlistat (60 or 120 mg) three times a day, combined with a hypocaloric diet
during the first year and a weight maintenance diet in the second year of
treatment to prevent weight regain. Changes in body weight, lipid profile,
glycemic control, blood pressure, quality of life, safety, and tolerability were
measured. RESULTS: Orlistat-treated patients lost significantly more weight
(p<0.001) than placebo-treated patients after Year 1 (6.6%, 8.6%, and 9.7% for
the placebo, and orlistat 60 mg and 120 mg groups, respectively). During the
second year, orlistat therapy produced less weight regain than placebo (p = 0.005
for orlistat 60 mg; p<0.001 for orlistat 120 mg). Several obesity-related risk
factors improved significantly more with orlistat treatment than with placebo.
Orlistat was generally well tolerated and only 6% of orlistat-treated patients
withdrew because of adverse events. Orlistat leads to predictable
gastrointestinal effects related to its mode of action, which were generally
mild, transient, and self-limiting and usually occurred early during treatment.
DISCUSSION: Orlistat administered for 2 years promotes weight loss and minimizes
weight regain. Additionally, orlistat therapy improves lipid profile, blood
pressure, and quality of life.
PMID- 10678260
TI - Lipoprotein subpopulation distributions in lean, obese, and type 2 diabetic
women: a comparison of African and white Americans.
AB - OBJECTIVE: Abnormal subpopulation distributions of plasma lipoproteins have been
reported in white American (WA) women with obesity and type 2 diabetes that
explain part of the elevated rate of cardiovascular disease in these patients.
This study examined if these perturbations also occur in obese and diabetic
African American (AA) women and compared the lipoprotein profiles with WA
counterparts. RESEARCH METHODS AND PROCEDURES: We determined the lipoprotein
subpopulation distribution in the plasma of 51 lean women (29 WA, 22 AA, body
mass index [BMI] < 30), 50 obese women (27 WA, 23 AA, BMI > 30), and 43 obese
women with type 2 diabetes (27 WA, 16 AA), by nuclear magnetic resonance
spectroscopy. RESULTS: AA diabetic women, like WA diabetic women, had a larger
average very low density lipoprotein (VLDL) size, elevated levels of small low
density lipoprotein cholesterol (LDL-C), and lower levels of small high density
lipoprotein cholesterol (HDL-C), when compared to lean controls (p<0.05). These
differences were accompanied by higher VLDL-triglycerides (TG) and LDL-C in WA
(p<0.05), but not in AA. Although the effects of obesity and diabetes on
lipoprotein subpopulation were fairly similar for AA and WA, some racial
differences, particularly with respect to HDL, were observed. DISCUSSION: The
atherogenic perturbations in lipoprotein profiles of obese AA women, particularly
those with diabetes, were relatively similar to those found in WA women and may
be contributing to the increased rate of cardiovascular disease (CVD) in AA with
obesity and diabetes. The parameters of subpopulation distribution may provide
better markers for CVD than lipid concentrations alone, particularly in AA women.
Furthermore, subtle racial differences in lipoprotein profiles suggest that race
specific criteria may be needed to screen patients for CVD.
PMID- 10678261
TI - Six-month treatment of obesity with sibutramine 15 mg; a double-blind, placebo
controlled monocenter clinical trial in a Hispanic population.
AB - OBJECTIVE: To evaluate the safety and efficacy of sibutramine 15 mg by mouth once
per day in obese patients over a period of 6 months. RESEARCH METHODS AND
PROCEDURES: A monocenter, double-blind, placebo controlled, parallel, prospective
clinical trial was carried out. Sixty-nine male and female obese patients (body
mass index [BMI] > 30 kg/m2) aged 16 to 65 years entered the trial. RESULTS: 22
of 35 patients in the sibutramine group and 9 of 34 patients in the placebo group
completed the trial. The high dropout rate in the sibutramine group was due to
adverse events in 3 cases, lack of efficacy (as judged by patients) in 7, loss to
follow-up in 2, and an orthopedic device being worn in 1; in the placebo group
the dropouts were ascribed to lack of efficacy (as judged by patients) in 17
cases and to loss to follow-up in 8 cases. Using the method of last observation
carried forward, the weight loss in the sibutramine group was 10.27 kg (95%
confidence intervals [95% CI] 7.66; 13.07) and 1.26 kg (95% CI 0.3; 2.23) in the
placebo group. The BMI loss was 4.17 kg/m2 (95% CI 3.11; 5.22) in the sibutramine
group and 0.53 kg/m2 (95% CI 0.13; 0.92) in the placebo group. The waist
circumference reduction was 12.51 cm (95% CI 9.25; 15.77) in the sibutramine
group and 3.26 cm (95% CI 1.38; 5.14) in the control group (p<0.05 by paired
Student's t test for all the intragroup comparisons). Twenty-three sibutramine
patients had 34 adverse events, the most frequent adverse events in the
sibutramine group were upper respiratory tract infections (n = 6) and
constipation (n = 6); 16 placebo patients had 21 adverse events. Three
sibutramine patients withdrew their informed consent when they had adverse
events. DISCUSSION: The results show that sibutramine induces significant loss of
body weight and waist circumference. Cardiovascular function was not
significantly affected by sibutramine. Sibutramine was well tolerated by most of
the patients.
PMID- 10678262
TI - The expression of peroxisome proliferator-activated receptor gamma in pig fetal
tissue and primary stromal-vascular cultures.
AB - OBJECTIVE: This study was designed to determine when peroxisome proliferator
activated receptor gamma (PPARgamma) is expressed in developing fetal adipose
tissue and stromal-vascular adipose precursor cells derived from adipose tissue.
In addition we examined developing tissue for CCAAT/enhancer-binding protein beta
(C/EBPbeta) expression to see if it was correlated with PPARgamma expression.
Pituitary function and hormones involved with differentiation (dexamethasone and
retinoic acid) were also tested for their effects on PPARgamma expression to
determine if hormones known to affect differentiation also effect PPARgamma
expression in vivo and in cell culture. RESEARCH METHODS AND PROCEDURES:
Developing subcutaneous adipose tissues from the dorsal region of the fetal pig
were collected at different gestation times and assayed using Western blot
analysis to determine levels of PPARgamma and C/EBPbeta. Hypophysectomy was
performed on 75-day pig fetuses and tissue samples were then taken at 105 days
for Western blot analysis. Adipose tissue was also taken from postnatal pigs to
isolate stromal-vascular (S-V) cells. These adipose precursor cells were grown in
culture and samples were taken for Western blot analysis to determine expression
levels of PPARgamma. RESULTS: Our results indicate that PPARgamma is expressed as
early as 50 days of fetal development in adipose tissue and continues through 105
days. Expression of PPARgamma was found to be significantly enhanced in adipose
tissue from hypophysectomized fetuses at 105 days of fetal development (p<0.05).
C/EBPbeta was not found in 50- or 75-day fetal tissues and was found only at low
levels in 105-day tissues. C/EBPbeta was not found in hypophysectomized (hypoxed)
105-day tissue where PPARgamma was elevated. S-V cells freshly isolated from
adipose tissue of 5- to 7-day postnatal pigs showed the expression of PPARgamma1.
When S-V cells were cultured, both PPARgamma1 and 2 were expressed after the
first day and continued as cells differentiated. High concentrations of retinoic
acid decreased PPARgamma expression in early S-V cultures (p<0.05). DISCUSSION:
Our data indicate that PPARgamma is expressed in fetal adipose tissue very early
before distinct fat cells are observed and can be expressed without the
expression of C/EBPbeta. The increase in PPARgamma expression after
hypophysectomy may explain the increase in fat cell size under these conditions.
Adipose precursor cells (S-V cells) from 5- to 7-day postnatal pigs also express
PPARgamma in the tissue before being induced to differentiate in culture. Thus S
V cells from newborn pig adipose tissue are probably more advanced in development
than the 3T3-L1 cell model. S-V cells may be in a state where PPARgamma and
C/EBPalpha are expressed but new signals or vascularization are needed before
cells are fully committed and lipid filling begins.
PMID- 10678263
TI - The human obesity gene map: the 1999 update.
AB - This report constitutes the sixth update of the human obesity gene map
incorporating published results up to the end of October 1999. Evidence from the
rodent and human obesity cases caused by single gene mutations, Mendelian
disorders exhibiting obesity as a clinical feature, quantitative trait loci (QTL)
uncovered in human genome-wide scans and in crossbreeding experiments with mouse,
rat, pig and chicken models, association and linkage studies with candidate genes
and other markers is reviewed. Twenty-five human cases of obesity can now be
explained by variation in five genes. Twenty Mendelian disorders exhibiting
obesity as one of their clinical manifestations have now been mapped. The number
of different QTLs reported from animal models reaches now 98. Attempts to relate
DNA sequence variation in specific genes to obesity phenotypes continue to grow,
with 89 reports of positive associations pertaining to 40 candidate genes.
Finally, 44 loci have linked to obesity indicators in genomic scans and other
linkage study designs. The obesity gene map depicted in Figure 1 reveals that
putative loci affecting obesity-related phenotypes can be found on all autosomes,
with chromosomes 14 and 21 showing each one locus only. The number of genes,
markers, and chromosomal regions that have been associated or linked with human
obesity phenotypes continues to increase and is now well above 200.
PMID- 10678264
TI - Population advice on salt restriction: the social issues.
AB - The scientific evidence that underlies public health advice depends upon critical
integration of information from several sources. The most informative evidence
relating to the effects of population reduction in salt intake comes from
systematic reviews of clinical trials. Recent rigorous reviews of salt
restriction trials in normal subjects show extremely small effects ranging from 1
to 2 mm Hg for systolic blood pressure and 0.1 to 1.0 mm Hg for diastolic
pressure. These are the result of much greater reductions in sodium intake than
can be achieved by population advice, and may be further amplified by publication
bias and effects of changes in other dietary components. There is little trial
evidence to enable possible benefits and adverse effects to be balanced. Reviews
biased by the inclusion of nonrandomized studies exaggerate the apparent blood
pressure fall 5- to 50-fold and create spurious apparent progressive falls in
blood pressure. Nevertheless, citation analysis shows that they are quoted much
more frequently than rigorous reviews reaching more negative conclusions. This
appears to be the result of an attempt to create an impression of scientific
consensus. The salt debate has important implications for social policy.
PMID- 10678265
TI - Evidence in favor of moderate dietary sodium reduction.
PMID- 10678266
TI - Plasma homocysteine concentrations and insulin sensitivity in hypertensive
subjects.
AB - Hyperhomocysteinemia is associated with several cardiovascular disease risk
factors including endothelial dysfunction and abnormalities of clotting
functions, which are also common features of insulin resistance syndrome observed
in hypertensive patients. Recent study has shown that acute hyperinsulinemia can
lower plasma homocysteine concentrations in nondiabetic but not in type 2
diabetic individuals, indicating that insulin may regulate homocysteine
metabolism. To investigate the relationships between plasma homocysteine
concentration and insulin sensitivity, we studied 90 Chinese hypertensive
patients and a group of control subjects (n = 86) matched for age, gender, and
body mass index. Fasting plasma homocysteine levels, plasma lipoprotein
concentrations, plasma glucose, and insulin responses to oral glucose tolerance
tests (OGTT) were determined. The results showed that fasting plasma homocysteine
concentrations were significantly higher in subjects with hypertension than in
those with normotension (mean +/- SEM, 8.1 +/- 0.6 v 6.8 +/- 0.2 micromol/L; P <
.05). Fasting plasma homocysteine levels correlated significantly with insulin
secretion in response to OGTT even after adjustment for body mass index (P < .05)
in hypertensive patients but not in normotensive individuals. However, fasting
plasma homocysteine concentrations showed no correlations with steady-state
plasma glucose concentration, a measurement of insulin sensitivity, during an
insulin suppression test in groups of hypertensive (n = 42) and normotensive (n =
37) subjects. When the steady-state plasma glucose concentrations were divided
into three tertiles, fasting plasma homocysteine concentrations showed no
difference across these three groups in either hypertensive patients (8.6 +/- 0.5
v 7.2 +/- 0.5 v 8.4 +/- 0.6 micromol/L; P = .148) or normotensive subjects (6.3
+/- 0.4 v 8.0 +/- 0.8 v 7.0 +/- 0.8 micromol/L; P = .199). In conclusion,
hypertensive Chinese subjects had higher fasting plasma homocysteine
concentrations and a higher degree of insulin resistance when compared to a group
of age-, gender-, and body mass index-matched normotensive individuals. Fasting
plasma homocysteine levels were associated with insulin response to OGTT in
hypertensives but not in normotensives. No correlation was observed between the
degree of insulin resistance and plasma homocysteine levels in either the
hypertensive or the normotensive group. The role of insulin in homocysteine
metabolism deserves further investigation.
PMID- 10678267
TI - Effects of hyperinsulinemia on sympathetic responses to mental stress.
AB - In a recent study, we could not find evidence to support the hypothesis that
insulin activates the sympathetic nervous system (SNS) during a hyperinsulinemic
glucose clamp procedure. Mental stress tests (MST), however, may be used to
detect differences in blood pressure and SNS activity that are not present during
baseline or resting conditions. In this study, we aimed to investigate the
effects of hyperinsulinemia during glucose clamp on blood pressure and
sympathetic responses to mental stress. Borderline hypertensive but otherwise
healthy 21-year-old men (n = 18) underwent 5 min of mental arithmetic stress
testing (MST-1) before and at the end of 120 min of isoglycemic hyperinsulinemic
glucose clamp (MST-2) with infusion rates of glucose and insulin kept constant.
Insulin concentration increased from 119 +/- 10 pmol/L to 752 +/- 65 pmol/L. We
observed highly significant increases in blood pressure and heart rate in
response to MST, but neither insulin nor saline solution infusions affected these
responses. During MST-1, norepinephrine increased by 461 +/-165 pmol/L (mean +/-
SEM) and epinephrine by 218 +/- 76 pmol/L. During MST-2 the changes were 372 +/-
112 pmol/L and 187 +/- 60 pmol/L, respectively. The norepinephrine (P = .8) and
epinephrine (P = .7) responses were unchanged by insulin. Thus, there were
similar increases in blood pressure, heart rate, and plasma catecholamine
concentrations in arterialized venous blood in response to MST despite the
infusion of insulin. A possible time effect was excluded by including a saline
solution control group (n = 7) that showed almost identical results. Our results
suggest that acute hyperinsulinemia during isoglycemic glucose clamp does not
interfere with cardiovascular or sympathetic responses to mental stress.
PMID- 10678268
TI - Sympathoexcitatory responses to the acute blood pressure fall induced by central
or peripheral antihypertensive drugs.
AB - This study was designed to evaluate the effects of an acute blood pressure
reduction brought about by a peripheral vasodilator agent (prazosin) or by a drug
combining central and peripheral modes of action (urapidil), on three markers of
adrenergic tone such as muscle sympathetic nerve traffic (MSNA), venous plasma
norepinephrine (NE), and heart rate (HR). In 12 untreated essential hypertensives
(age, 50.7 +/- 1.9 years; mean +/- SEM), we evaluated in two experimental
sessions, according to a double-blind crossover design, the effects of acute oral
administration of 2 mg prazosin or 30 mg urapidil on beat-to-beat finger blood
pressure (Finapres), HR (electrocardiogram), NE (high-performance liquid
chromatography), and MSNA (microneurography at a peroneal nerve). In each session
measurements were performed in the no-drug control state and repeated throughout
a 3-h period after drug administration. For similar blood pressure reductions,
the two drugs caused similar increases in NE and MSNA (peak effects: NE = +1.1 +/
0.2 vs 0.9 +/- 0.2 nmol/L and MSNA = +10.9 +/- 1.8 vs +10.1 +/- 1.6 bursts/min
for prazosin and urapidil respectively, P = ns between drugs), whereas HR
increased more markedly after prazosin administration (+6.1 +/- 1.1 vs +2.4 +/-
0.8 beats/min, P < 0.05). These data provide evidence that acute blood pressure
reductions induced by antihypertensive drugs with central or peripheral modes of
action activate the sympathetic nervous system to a similar extent. Thus
adrenergic activation is not peculiar to vasodilators but rather generalized to
any drug-induced acute blood pressure fall, presumably because of the lack of a
baroreflex resetting, which occurs during chronic but not during acute
antihypertensive treatment.
PMID- 10678269
TI - Changes in clinical features and long-term prognosis in patients with
pheochromocytoma.
AB - To investigate changes in preoperative clinical features and the long-term
outcome of tumor recurrence, mortality, and morbidity in patients with
pheochromocytoma, we retrospectively examined changes in the clinical features by
comparing 49 patients from 1957 to 1985 (group I) with 46 patients from 1986 to
December 1995 (group II). In addition in these 95 patients (excluding 2 who had
died before operation), we evaluated long-term postoperative outcome from the
initial operation to August 1996 (909 patient-years). The mean age in group II
was older than that of group I. The percentage of patients having proteinuria or
hypertensive retinopathy in group II was less than that in group I. Of 20
patients with incidentally discovered pheochromocytoma, 7 (35%) were > or =60
years old, 7 asymptomatic, and 11 (55%) normotensive. Plasma and urinary
catecholamines in these patients were significantly (P < .01) lower than in
patients with pheochromocytoma having typical clinical features. Long-term cohort
study showed 14 deaths. Relative survival rates were 91% at 5 years and 83% at 10
years and unchanged thereafter. The Kaplan-Meier estimate of pheochromocytoma
free survival was shorter in patients with a larger-than-median (60 g) tumor
weight. Six patients had malignant recurrence 3 to 101 months (median, 45 months)
after the initial operation. Of 65 patients confirmed alive at follow-up, 11 were
hypertensive. In the Cox model, hypertension-free survival was not associated
with age, a family history of hypertension, duration of hypertension, or
creatinine clearance. Pheochromocytoma should be diagnosed from a wide spectrum
of clinical features including those that are not generally suspected of
resulting from excess catecholamines or hypertension, and after surgery, patients
with this disease should be followed-up carefully for a long period (at least 10
years) because of the risk of tumor recurrence and the high prevalence of
disease.
PMID- 10678270
TI - Ambulatory blood pressure after acute exercise in older men with essential
hypertension.
AB - We sought to determine whether reductions in blood pressure in hypertensives
after acute exercise persist for more than the 2 to 3 h found in controlled
laboratory settings. Subjects (n = 11) were obese (32 +/- 4% body fat), sedentary
(VO2max 27 +/- 4 mL/kg/min) 60 +/- 6-year-old men with stage 1 or 2 essential
hypertension. Ambulatory blood pressure was recorded on 1 day preceded by 45 min
of 70% VO2max treadmill exercise and on another day not preceded by exercise.
Systolic blood pressure was lower by 6 to 13 mm Hg for the first 16 h after
exercise (P < .05) compared to the day without prior exercise. Twenty-four-hour,
day, and night average systolic blood pressures were significantly lower on the
day after exercise. There was a trend for peak systolic blood pressure to be
lower during the entire 24 h and the day portion of the recording; peak systolic
blood pressure was significantly lower during the night portion of the recording
after exercise. Systolic blood pressure load (percent of systolic blood pressure
readings >140 mm Hg) was reduced during the entire 24 h and the day portion of
the recording after exercise. Diastolic blood pressure was lower for 12 of the
first 16 h after acute exercise (hours 0 to 4, 5 to 8, 13 to 16) (P < .05)
compared to the day without prior exercise. Twenty-four-hour, day, and night
average diastolic blood pressure was also significantly lower on the recording
after exercise. Peak diastolic blood pressure was lower over the entire 24-h
period. Diastolic blood pressure load (percent of diastolic blood pressure
readings >90 mm Hg) was lower during the entire 24 h and the day portion of the
day after exercise. Preliminary data also suggest that common genetic
polymorphisms at the angiotensinogen, lipoprotein lipase, and angiotensin
converting enzyme loci may affect the blood pressure-lowering response after
acute exercise. Thus, in sedentary, obese hypertensive men a single aerobic
exercise session reduced blood pressure enough to result in significantly lower
24-h average systolic, diastolic, and mean arterial blood pressure. This could
result in a reduced cardiovascular load during the 24 h after acute exercise in
older hypertensive men.
PMID- 10678271
TI - Predictors of interindividual variation in ambulatory blood pressure and their
time or activity dependence.
AB - The objectives of this study were to determine whether total interindividual
variation in blood pressure (BP) differs between inactive and active hours of the
day, to identify predictors of interindividual variation in BP, and to assess
whether variation associated with any of these identified predictors is greater
(or less) during inactive hours than during active hours of the day. We obtained
ambulatory BP recordings over 20 consecutive hours (12 active, out of bed
[daytime]; and 8 inactive, in bed [nighttime]) in a sample of 240 unrelated, non
Hispanic white adults (138 men; 102 women). We estimated total interindividual
variation in BP, and the percentage of interindividual variation associated with
measures of age and body size, metabolic traits, catecholamines, erythrocyte
cation transport, and renal function. We used linear regression to assess changes
in the hourly estimates of total interindividual variation and in variation
attributable to each set of predictor traits over the 20 h. In both men and
women, total interindividual variation in systolic BP was significantly greater
(not less) during inactive hours than during active hours. In addition, in women,
total interindividual variation in diastolic BP was as great during inactive
hours as during active hours. Each set of traits considered predicted a
statistically significant percentage of interindividual variation in BP. None of
the sets of traits predicted a greater percentage of interindividual variation
during the inactive hours than during the active hours. Measures of age and body
size, catecholamines, cation transport and renal function traits predicted
significantly less interindividual variation during inactive hours than during
active hours of the day. That total interindividual variation in BP is as great
or greater during inactive hours than during active hours of the day emphasizes
the potential for differences in nighttime BP to contribute to the development of
cardiovascular disease. In as much as the predictors of interindividual variation
in BP differ between the daytime and nighttime, the causes of variation during
these two times may also differ.
PMID- 10678272
TI - Resistance to activated protein C and FV leiden mutation in patients with a
history of acute myocardial infarction or primary hypertension.
AB - This study was designed to investigate both resistance to activated protein C
(APC-R) and the factor FV Q506 mutation incidence in patients with a history of
acute myocardial infarction (AMI) and patients with primary hypertension (PH), a
high-risk group for arterial thrombosis. Eighty patients with a history of AMI
(group A), 160 patients with a history of PH (group B), and 124 age-matched
controls without arterial disease (group C) were studied. APC-R was determined
using the Coatest APC Resistance Kit of Chromagenix, Sweden. The prevalence of
the FV Q506 mutation was estimated by DNA analysis (Bertina method). The
prevalence of the FV Q506 mutation was 20%, 13.75%, and 8% in groups A, B, and C,
respectively (A v C P = .0466). The prevalence of APC-R was 47.5% in group A v
13% in group C (P < .0001) and 36.25% in group B v 13% in group C (P < .0001).
The response to activated protein C expressed as mean value +/- SD was 2.05 +/-
0.33 in group A v 2.56 +/- 0.46 in group C (P < .05) and 2 +/- 0.22 in group B v
2.56 +/- 0.46 in group C (P < .05). These findings suggest that patients with a
history of AMI or PH have a significantly increased incidence of both APC-R and
FV Q506 mutation compared with the control group. These findings support the
hypothesis that these anticoagulant defects may be risk factors for arterial
thrombosis.
PMID- 10678273
TI - Human chorionic gonadotrophin is an endothelium-independent inhibitor of rat
aortic smooth muscle contractility.
AB - The study tested the hypothesis that human chorionic gonadotrophin (hCG)
attenuates isolated vascular smooth muscle contractility and investigated the
role of the vascular endothelium in hCG-induced altered responses of vascular
smooth muscle. The contractile responses of isolated aortic rings from normal,
hCG-treated, and estrogen-treated female virgin Wistar rats to phenylephrine,
angiotensin II, KCl, and CaCl2 were compared. The effect of pretreatment with N
monomethyl-L-arginine (L-NMMA), methylene blue, indomethacin, calcium-free
medium, and de-endothelialization on responses to phenylephrine of aortic rings
from control and hCG-treated rats were also examined. Intraperitoneal
administration of hCG caused attenuation of contractile responses of isolated
aortic rings to all agents. The attenuated responses to phenylephrine were not
reversed by de-endothelialization, or pretreatment of the rings with L-NMMA,
methylene blue, or indomethacin. It was concluded that hCG attenuates vascular
smooth muscle contractility. The effect is independent of the vascular
endothelium, not agonist-specific, and appears to involve alterations of calcium
availability.
PMID- 10678274
TI - Peroxisome proliferator-activated receptor (PPAR)-gamma expression in human
vascular smooth muscle cells: inhibition of growth, migration, and c-fos
expression by the peroxisome proliferator-activated receptor (PPAR)-gamma
activator troglitazone.
AB - This study was conducted to determine whether cultured human coronary artery and
aorta vascular smooth muscle (VSM) cells express the nuclear transcription factor
peroxisome proliferator-activated receptor-gamma (PPARgamma); whether the
thiazolidinedione troglitazone, a ligand for PPARgamma, would inhibit c-fos
expression by these cells; and whether troglitazone would inhibit proliferation
and migration induced in these cells by mitogenic growth factors. Using
immunoblotting and reverse-transcriptase polymerase chain reaction (RT-PCR)
techniques, we show that both human aorta and coronary artery VSM cell lines
expressed PPARgamma protein and mRNA for both PPARgamma isoforms, PPARgamma1 and
PPARgamma2. Immunocytochemical staining localized the PPARgamma protein primarily
within the nucleus. Troglitazone inhibited basic fibroblast growth factor and
platelet-derived growth factor-BB induced DNA synthesis in a dose-dependent
manner and downregulated the growth-factor-induced expression of c-fos.
Troglitazone also inhibited the migration of coronary artery VSM cells along a
platelet-derived growth factor-BB concentration gradient. These findings
demonstrate for the first time the expression and nuclear localization of
PPARgamma in human coronary artery and aorta VSM cells. The data also suggest
that the downregulation of c-fos expression, growth-factor-induced proliferation,
and migration by VSM may, in part, be mediated by activation of the PPARgamma
receptor.
PMID- 10678275
TI - Modulation of endothelin-1 coronary vasoconstriction in spontaneously
hypertensive rats by the nitric oxide system.
AB - To determine whether nitric oxide contributes to the augmented vasoconstrictive
response to endothelin-1 (ET-1) in coronary vessels of hypertensive hearts, and
also whether L-arginine administration can inhibit the augmented response to ET
1, we designed experiments to measure coronary perfusion resistance in isolated
hearts of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto
rats (WKY) with or without L-arginine administration (0.5 g/L) for 2 weeks. The
hearts were paced at a constant rate and perfused by the Langendorff technique at
constant pressure (75 mm Hg). Perfusion flow and pressure were monitored, and
coronary vascular resistance (CVR) was calculated. ET-1 infusion elicited dose
dependent increases in CVR in both WKY and SHR. At an ET-1 concentration of 1.5 x
10(-9) mol/L, the response was significantly greater in SHR. In L-NAME-treated
WKY and SHR, responses to ET-1 were augmented, compared with those of nontreated
rats, and this augmentation was greater in WKY. L-arginine administration reduced
the CVR response to ET-1 in SHR, whereas it did not change responses to ET-1 in
WKY. These findings suggest that the augmented vasoconstriction of the coronary
artery induced by ET-1 in hypertensive hearts was due to a reduction in nitric
oxide release in coronary vessels and that L-arginine can partially inhibit the
vasoconstrictive response of the coronary artery.
PMID- 10678276
TI - Influence of correction for within-person variability in blood pressure on the
prevalence, awareness, treatment, and control of hypertension.
AB - We assessed the influence of correction for within-person variability (WPV) on
the prevalence, awareness, treatment, and control of hypertension. Data were
collected from two cross-sectional population-based studies on cardiovascular
disease risk factors from 1987 to 1995 among 56,026 subjects aged 20 to 59 years.
Correction factors were calculated from an internal reproducibility study among
924 subjects who were examined in 1989 and 1990. The prevalence of hypertension
without a correction of blood pressure values for WPV was substantially
overestimated (38%), whereas the prevalence of awareness and treatment of
hypertension were substantially underestimated (-13% and -28%). The prevalence of
control of hypertension did not change much after this correction. It may be
advisable to perform a correction for within-person variability to obtain valid
prevalence estimates in surveys that only take one or two measurements of blood
pressure.
PMID- 10678277
TI - Reproducibility of heart rate measured in the clinic and with 24-hour
intermittent recorders.
AB - This study was undertaken to assess the reproducibility of office versus
ambulatory heart rates in 839 hypertensive subjects participating in the
Hypertension and Ambulatory Recording Venetia Study (HARVEST). A 24-hour heart
rate was recorded twice; this procedure was repeated three months later.
Reproducibility was better for ambulatory than for office measurement, and was
greater for 24-hour than for daytime heart rate, and lowest for night-time heart
rate. Reproducibility of office heart rate was impaired above 85 bpm, and was
poorer in subjects with more severe office hypertension. A small but significant
decrease in average daytime (-1 bpm, P < 0.0001) and virtually no change in night
time heart rate (-0.3 bpm, NS) were observed at repeat recording. Heart rate
reproducibility indices were related to the extent of the heart rate and blood
pressure white-coat effect, but did not vary according to age, gender, body mass
index, day-night blood pressure difference, or alcohol or tobacco use. Results
indicate that heart rate recorded over the 24 hours has a better reproducibility
than office heart rate, and could thus be a better prognostic indicator than
traditional measurement of resting heart rate in the hospital setting.
PMID- 10678278
TI - Chronic intravenous glucose infusion causes moderate hypertension in rats.
AB - We have reported that chronic insulin infusion increases mean arterial pressure
(MAP) in rats. In those studies, glucose was coinfused to prevent hypoglycemia,
but it is possible that the glucose infusion rate may have exceeded the rate
actually required to prevent hypoglycemia. If true, then the glucose infusion
alone should have a similar effect, and this study tested that hypothesis. In six
rats (insulin group) instrumented with artery and vein catheters, insulin was
infused for 7 days intravenously (iv) at 1.5 mU/kg/min together with glucose iv
at 18.6 mg/kg/min. Seven other rats (glucose group) received the same glucose
infusion for 7 days but without iv insulin. MAP increased significantly in both
groups, from 98 +/- 3 and 96 +/- 2 mm Hg to 107 +/- 5 and 104 +/- 3 mm Hg in the
insulin and glucose groups, respectively, and the renal and hormonal changes were
similar to those previously reported during insulin infusion. There were no
significant differences between the two groups for any variable measured. These
data indicate that the sugar intake provided by the glucose infusion essentially
mimics the response to our insulin and glucose infusion protocol, and that
similar mechanisms underlie the renal and cardiovascular responses to each
protocol.
PMID- 10678279
TI - Statement from the National High Blood Pressure Education Program: prevalence of
hypertension.
PMID- 10678280
TI - What level of plasma homocyst(e)ine should be treated? Effects of vitamin therapy
on progression of carotid atherosclerosis in patients with homocyst(e)ine levels
above and below 14 micromol/L.
AB - High levels of plasma homocyst(e)ine (H[e]) are associated with increased
vascular risk. Treatment is being contemplated, but the level at which patients
should be treated is not known. We compared the response of carotid plaque to
vitamin therapy in patients with H(e) above and below 14 micromol/L, a level
commonly regarded as high enough to warrant treatment. Two-dimensional B-mode
ultrasound measurement of carotid plaque was used to assess the response to
vitamin therapy with folic acid 2.5 mg, pyridoxine 25 mg, and cyanocobalamin 250
microg daily, in 101 patients with vascular disease (51 with initial plasma
levels above, and 50 below 14 micromol/L). Among patients with plasma H(e) >14
micromol/L, the rate of progression of plaque area was 0.21 +/- 0.41 cm2/year
before vitamin therapy, and -0.049 +/- 0.24 cm2/year after vitamin therapy (P2 =
.0001; paired t test). Among patients with levels <14 micromol/L, the rate of
progression of plaque was 0.13 +/- 0.24 cm2/year before vitamin therapy and
0.024 +/- 0.29 cm2/year after vitamin therapy (P2 = .022, paired t test). The
change in rate of progression was -0.15 +/- .44 cm2/year below 14 micromol/L, and
-0.265 +/- 0.46 cm2/year above 14 micromol/L (P = 0.20). Vitamin therapy
regresses carotid plaque in patients with H(e) levels both above and below 14
micromol/L. These observations support a causal relationship between
homocyst(e)ine and atherosclerosis and, taken with epidemiologic evidence,
suggest that in patients with vascular disease, the level to treat may be <9
micromol/L.
PMID- 10678281
TI - Carotid thickening, cardiac hypertrophy, and angiotensin converting enzyme gene
polymorphism in patients with hypertension.
AB - An insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme
(ACE) gene has been associated with increased risk for myocardial infarction,
cardiomyopathy, carotid thickening, and cardiac hypertrophy. However, a
conclusive agreement about the role of ACE genotype in the genetics of
cardiovascular disease has not yet been reached. This study was undertaken to
investigate the relationship of the I/D polymorphism of the ACE gene with carotid
intima-media thickness (IMT) and left ventricular mass (LVM) in 175 Chinese
patients with mild-to-moderate hypertension. The I/D genotypes were detected by
the polymerase chain reaction using primers flanking the polymorphic region in
intron 16 of the ACE gene. The IMT was measured in the common carotid and carotid
bifurcation by B-mode ultrasound. The LVM was calculated with M-mode
echocardiographic measures of the left ventricle. Patients with the DD genotype
(n = 41) showed significant greater carotid IMT (1.593 +/- 0.879 v 1.309 +/-
0.703 and 1.171 +/- 0.583 mm, P = .01) but insignificant higher LVM index (123.8
+/- 36.6 v 123.7 +/- 37.4 and 118.2 +/- 33.0 g/m2, P = .61) than did those with
the DI (n = 69) and II (n = 65) genotypes. The deletion polymorphism of the ACE
gene (P = .04) was a significant predictor for carotid IMT on multiple regression
analysis, controlling all the potential confounding factors including age (P =
.001), systolic blood pressure (P = .09), smoking (P = .08), and plasma tissue
plasminogen activator antigen (P = .03), but the LVM correlated only with age (P
= .02), sex (P < .001), and body mass index (P < .001). These results indicated
that the DD genotype of the ACE gene could be considered a risk factor for the
development of early atherosclerosis in carotid arteries but not for left
ventricular hypertrophy in the hypertensive population.
PMID- 10678282
TI - Risk stratification in hypertension: new insights from the Framingham Study.
AB - Five decades of epidemiologic research have established that blood pressure
elevation is a common and powerful contributor to all of the major cardiovascular
diseases, including coronary disease, stroke, peripheral artery disease, renal
disease, and heart failure. The common variety of hypertension designated benign
essential hypertension was not shown to be either benign or essential. Although
clinicians favor the diagnosis and treatment of hypertension in terms of
diastolic blood pressure elevation and categoric cut points, epidemiologic data
show a more important influence of systolic blood pressure, and a continuous,
graded influence of blood pressure even within what is regarded as the
normotensive range. An important revelation in epidemiologic hypertension
research is that hypertension usually occurs in conjunction with other
metabolically linked risk factors; therefore, less than 20% occurs in isolation.
The other risk factors that tend to accompany hypertension include glucose
intolerance, obesity, left ventricular hypertrophy, and dislipidemia (elevated
total, LDL, and small dense LDL cholesterol levels, raised triglyceride, and
reduced HDL cholesterol levels). Clusters of three or more of these additional
risk factors occur at four times the rate expected by chance. This clustering is
attributed to an insulin resistance syndrome promoted by abdominal obesity. The
amount of risk factor clustering accompanying elevated blood pressure was
observed to increase with weight gain. Based on Framingham Study data the
prevalence of insulin resistance syndrome in the general population could be as
high as 22% in men and 27% in women. Risk of coronary disease, the most common
and most lethal sequel to hypertension, increased stepwise with the extent of
risk factor clustering. Among persons with hypertension, about 40% of coronary
events in men and 68% in women are attributable to the presence of two or more
additional risk factors. Only 14% of coronary events in hypertensive men and 5%
of those in hypertensive women occurred in the absence of additional risk
factors. Other important features of risk stratification of hypertension are the
presence of an elevated heart rate and left ventricular hypertrophy, and an
elevated fibrinogen that often accompany hypertension. Recent population-based
data reported suggest that elevated renin accompanying hypertension may
independently enhance the risk of coronary events. Because clustering of other
major risk factors with hypertension is the rule, the prudent physician should
routinely screen for the presence of these other factors. Multivariate risk
assessment profiles are now available for coronary disease, stroke, peripheral
artery disease, and heart failure, to enable physicians to pool all the relevant
risk factor information so as to arrive at a composite risk estimate.
Hypertensive patients are more appropriately targeted for therapy by such risk
stratification and the goal of the therapy should be to improve the multivariate
risk profile.
PMID- 10678283
TI - Trials of antihypertensive treatment--new agenda for the millennium.
AB - In 1968 a group of investigators from the US Veterans Association study reported
that, compared to placebo, antihypertensive medication dramatically reduces
morbidity and mortality in patients whose diastolic blood pressure was 115 mm Hg
or higher. Three years later a reduction of morbidity had also been demonstrated
in subjects whose diastolic pressure ranged from 95 to 114 mm Hg. In the
following decades these findings were confirmed in numerous investigations of
various populations. We now know that antihypertensive treatment is beneficial in
mild hypertension, in isolated systolic hypertension, and in hypertension of the
elderly. When it comes to the treatment of mild hypertension we will have to
practice evidenceless medicine and act on the internal logic of the issue. The
logic suggests that many present-day antihypertensive agents are harmless, that
over the long term they may prevent target organ damage, that early intervention
may be more beneficial than late treatment, and, finally, that treating mild
hypertension may have a major positive impact on public health.
PMID- 10678284
TI - Newly emerging pharmacologic differences in angiotensin II receptor blockers.
AB - Several angiotensin II receptor blockers (ARB) are currently available for the
treatment of hypertension. These drugs share a common mechanism of action
antagonism of angiotensin II AT1 receptors; however, their receptor binding
kinetics differ. Candesartan has a higher affinity for the AT1 receptor than all
the other ARB. In addition, candesartan and irbesartan block the AT1 receptor
with insurmountable antagonism, whereas losartan, valsartan, and eprosartan are
competitive antagonists. The pharmacokinetics of these ARB also differ in terms
of oral bioavailability, rate of absorption, metabolism, and route and rate of
elimination. Both losartan potassium and candesartan cilexetil are prodrugs;
however, losartan is partially converted into EXP3174 in the liver, whereas
candesartan cilexetil is converted completely into candesartan during
gastrointestinal absorption. On the basis of elimination half-lives, losartan,
valsartan, and eprosartan may be classified as shorter acting and candesartan
cilexetil and irbesartan as longer acting. Each drug effectively lowers blood
pressure during once daily administration to patients with mild to moderate
hypertension, with candesartan cilexetil requiring the lowest dosage and
providing dose-dependent efficacy. Initial comparative clinical trials suggest
that both candesartan cilexetil and irbesartan in the doses used are
significantly more effective than losartan in lowering trough sitting diastolic
blood pressure. It remains to be determined, however, whether the observed
pharmacologic and pharmacokinetic differences among the members of the ARB class
will have a clinically significant impact on long-term cardiovascular outcomes
and reductions of cardiovascular mortality.
PMID- 10678285
TI - Update on the clinical pharmacology of candesartan cilexetil.
AB - The renin-angiotensin system plays a central role in the regulation of blood
pressure through its primary effector hormone angiotensin II. Studies conducted
nearly 30 years ago with peptidic angiotensin II receptor blockers (ARB)
suggested that disruption of the renin-angiotensin system offered considerable
promise for the treatment of hypertension as well as heart failure. This promise
was initially realized with the advent of angiotensin converting enzyme
inhibitors, and more recently with nonpeptidic ARB that selectively antagonize
the AT1-angiotensin receptor subtype. The potent and long-acting agent
candesartan cilexetil illustrates how these new ARB fulfill the promises
suggested by the early studies. Candesartan cilexetil provides a clinically
relevant, dose-dependent reduction in diastolic and systolic blood pressure at
doses of 4 to 16 mg once daily in patients with mild to moderate hypertension.
Recent studies suggest that further blood pressure lowering is obtained with a 32
mg once daily dose. In comparative clinical trials, 8 mg of candesartan cilexetil
and 10 to 20 mg of enalapril provided comparable antihypertensive effects. The
safety and tolerability profile of candesartan cilexetil is comparable to
placebo. Notably, this agent does not produce the dry, nonproductive cough that
often limits use of angiotensin converting enzyme inhibitors, nor does it cause
side effects that limit other antihypertensive drug classes. On the basis of the
results of initial clinical studies, ARB also possess cardioprotective and
renoprotective properties that promise to expand the role that these new agents
will play in treating cardiovascular disorders.
PMID- 10678286
TI - Localization and function of angiotensin AT1 receptors.
AB - The distributions of angiotensin AT1 and AT2 receptors have been mapped by in
vitro autoradiography throughout most tissues of many mammals, including humans.
In addition to confirming that AT1 receptors occur in sites known to be targets
for the physiologic actions of angiotensin, such as the adrenal cortex and
medulla, renal glomeruli and proximal tubules, vascular and cardiac muscle and
brain circumventricular organs, many new sites of action have been demonstrated.
In the kidney, AT1 receptors occur in high density in renal medullary
interstitial cells. The function of these cells, which span the interstitial
space between the tubules and the vasa rectae, remains to be determined. Renal
medullary interstitial cells possess receptors for a number of vasoactive
hormones in addition to AT1 receptors and this, in concert with their anatomic
location, suggests they may be important for the regulation of fluid reabsorption
or renal medullary blood flow. In the heart, the highest densities of AT1
receptors occur in association with the conduction system and vagal ganglia. In
the central nervous system, high AT1 receptor densities occur in many regions
behind the blood-brain barrier, supporting a role for neurally derived
angiotensin as a neuromodulator. The physiologic role of angiotensin in many of
these brain sites remains to be determined. The AT2 receptor also has a
characteristic distribution in several tissues including the adrenal gland,
heart, and brain. The role of this receptor in physiology is being elucidated,
but it appears to inhibit proliferation and to participate in development. Thus,
receptor-binding studies, localizing the distribution of AT1 and AT2 receptors,
provide many insights into novel physiologic roles of angiotensin.
PMID- 10678287
TI - AT1 receptors: coronary flow and flow reserve.
AB - Angiotensin II, through its effects at the angiotensin-type 1 receptor, elevates
arterial pressure and exacerbates hypertensive heart disease. Alterations in
coronary hemodynamics, including reductions in coronary blood flow and flow
reserve promotes coronary insufficiency and contributes to the increased
cardiovascular risk associated with these conditions. In spontaneously
hypertensive rats, coronary flow reserve, the difference between basal coronary
blood flow and the flow achieved during maximal coronary vasodilation achieved by
dipyridimole, was increased to a greater extent after treatment for 3 months with
an angiotensin II receptor blocker as compared with an angiotensin converting
enzyme inhibitor. The combination of the two agents, in equidepressor doses,
almost restored coronary flow reserve to levels seen in normotensive Wistar Kyoto
rats. This finding suggests a possible advantage of combination angiotensin
converting enzyme inhibitors and angiotensin II receptor blocker therapy in
patients with hypertension and hypertensive heart disease.
PMID- 10678289
TI - The role of pharmacists in the detection, management, and control of
hypertension: a national call to action.
PMID- 10678288
TI - Renal responses to AT1 receptor blockade.
AB - Because of the importance of the renin-angiotensin system in the pathophysiology
of hypertension and in mediating associated alterations in renal function,
angiotensin II (Ang II) AT1 receptor blockers provide a direct means of
protecting against influences of excessive Ang II levels. The kidney is an
important site of action of Ang II AT1 receptor blockers because intrarenal Ang
II not only vasoconstricts the renal vasculature but also reduces sodium
excretion and suppresses the pressure natriuresis relationship. Even in normal
conditions, intrarenal Ang II content is greater than can be explained on the
basis of circulating Ang II and is compartmentalized with proximal tubule
concentrations of Ang I and Ang II being several times higher than plasma
concentrations. The localization of angiotensinogen in proximal tubule cells
further supports the concept that the proximal tubule secretes Ang II or
precursors of Ang II into the tubular fluid to activate luminal Ang II receptors.
Recent immunohistochemical studies have demonstrated an abundance of AT1
receptors on the luminal surface of proximal and distal tubule cells as well as
on vascular smooth muscle cells of afferent and efferent arterioles and on
glomerular mesangial cells. Activation of luminal AT1 receptors stimulates the
sodium hydrogen exchanger and increases reabsorption rate. The prominence of AT1
receptors in vascular and epithelial tissues in the kidney provides the basis for
the powerful effects of AT1 receptor blockers on renal function especially in
hypertensive conditions. In the two-kidney, one-clip (2K1C) Goldblatt
hypertensive rat model, the nonclipped kidney is renin depleted but the
intrarenal Ang II levels are not suppressed and Ang II concentrations in proximal
tubular fluid remain high (10(-8) mol/L). AT1 receptor blockers such as
candesartan have been shown to cause significant increases in glomerular
filtration rate, renal blood flow and proportionately much greater increases in
sodium excretion and fractional sodium excretion. Ang II blockade also markedly
increases the slope of the pressure natriuresis relationship. The collective
actions of Ang II blockers on tubular transport and renal hemodynamics provide
long-term effects to regulate sodium balance, which contributes to the long-term
control of hypertension.
PMID- 10678290
TI - Levalbuterol nebulizer solution: is it worth five times the cost of albuterol?
AB - Albuterol is a 50:50 mixture of R-albuterol, the active enantiomer, and S
albuterol, which appears to be inactive in humans. The Food and Drug
Administration recently approved levalbuterol, the pure R-isomer, as a
preservative-free nebulizer solution. Published studies indicate that it is
neither safer nor more effective than an equimolar dose of racemic albuterol
(levalbuterol 1.25 mg = albuterol 2.5 mg). However, these studies were conducted
in patients with stable asthma (at the top of the dose-response curve), whereas a
nebulized bronchodilator most likely would be used by patients with an acute
exacerbation. Because such patients, in the hospital setting, often require
higher doses of albuterol, the manufacturer's recommended dose of levalbuterol is
likely to be too low for rescue therapy. Levalbuterol may cost as much as 5 times
more than racemic albuterol, depending on purchase method. We conclude that
levalbuterol offers no advantage over albuterol but is likely to be more costly.
PMID- 10678291
TI - Pharmacologic, pharmacokinetic, and therapeutic differences among angiotensin II
receptor antagonists.
AB - Over the past 4 years, six angiotensin II receptor antagonists (ARBs) were
approved for treating essential hypertension. They differ with respect to dosing,
metabolism, elimination, clinical efficacy, and investigational applications.
Candesartan cilexetil is the only prodrug among the agents. Losartan is
distinguished from other ARBs by cytochrome P450 (CYP) 3A4- and CYP2C9-mediated
biotransformation to its active metabolite EXP-3174. No ARB requires dosage
adjustment for renal impairment, but the initial dose of losartan should be
reduced 50% in hepatically impaired patients. None of the drugs is significantly
cleared by hemodialysis. Completion of continuing trials will elucidate the
drugs' role in treating heart failure, cerebral stroke, and myocardial
infarction.
PMID- 10678292
TI - Treatment of pediatric hypertension.
AB - We conducted a MEDLINE search from January 1966-March 1999 to obtain information
on clinical trials of treatment of pediatric hypertension. An article was
selected for review if it described a randomized or nonrandomized study;
randomized studies were given priority. Case reports were considered when studies
were unavailable. Review articles were useful in identifying references.
According to data we collected, hypertension is present in 1-3% of the pediatric
population. Nonpharmacologic treatment may be effective initially in those with
mild to moderate disease or as an adjunct to drug therapy. Drugs for treatment of
chronic hypertension include calcium channel blockers, angiotensin-converting
enzyme inhibitors, diuretics, and beta-blockers. Patient and drug characteristics
determine therapy. Intravenous labetalol, nicardipine, and nitroprusside are
effective for treating hypertensive emergencies.
PMID- 10678293
TI - Human immunodeficiency virus drug resistance testing: state of the art in
genotypic and phenotypic testing of antiretrovirals.
AB - Antiretroviral drugs have significantly reduced death rates from the acquired
immunodeficiency syndrome in the United States. They are highly effective in
reducing viral replication, but their utility is threatened by rapid development
of drug resistance. Although antiretroviral drug resistance testing is available
by either genotyping or phenotyping, no consensus guidelines have been published
regarding the appropriate use or interpretation of these new tests. Even though
their role in clinical practice is not defined, it is important for clinicians to
become familiar with relative advantages and disadvantages of genotypic and
phenotypic testing and various mechanisms of antiretroviral resistance.
PMID- 10678294
TI - A review of pathophysiology and therapy of patients with vasovagal syncope.
AB - Vasovagal syncope is a common disorder that can compromise quality of life and
lead to significant morbidity. It is characterized by an initial exaggerated
sympathetic output followed by parasympathetic activation and sympathetic
withdrawal, as shown by diagnostic head-up tilt (HUT) table testing. Numerous
drugs have been evaluated for treating this disorder. beta-Blockers are well
studied and commonly administered but are specifically more efficacious in
patients with isoproterenol HUT than in those with regular HUT. The role of the
serotonergic system has captured new interest. Selective serotonin reuptake
inhibitors show promising results in preventing vasovagal syncope in treatment
refractory patients. Also, new investigations suggest that serotonin receptor
antagonism may be beneficial. Despite these findings, definitive treatment does
not exist.
PMID- 10678295
TI - Aerosolized antimicrobial therapy in acutely ill patients.
AB - Recent data are sparking renewed interest in therapy with aerosolized
antimicrobials in critically ill patients as well as other populations such as
those with neutropenia, human immunodeficiency virus infection, and cystic
fibrosis. Pneumonia is a common complication in these patients and is associated
with substantial morbidity and increased mortality. Clinical trials evaluated
aerosolized antimicrobials for the prevention and treatment of pneumonia in
hospitalized patients. In addition, factors that affect the pulmonary deposition
of aerosolized drugs in mechanically ventilated patients were identified.
PMID- 10678296
TI - Evaluation of the influence of diabetes mellitus on antipyrine metabolism and
CYP1A2 and CYP2D6 activity.
AB - STUDY OBJECTIVE: To evaluate the metabolism of antipyrine, a general metabolic
probe, caffeine, a probe for cytochrome P450 (CYP) 1A2 and N-acetyltransferase
activity, and dextromethorphan, a specific probe for CYP2D6 activity in patients
with type 1 or 2 diabetes mellitus. DESIGN: Prospective, controlled study.
SETTING: Research facility. Patients. Fifteen patients with type 1 and 16 with
type 2 diabetes, and 16 healthy controls. INTERVENTION: Each subject
simultaneously received antipyrine 10 mg/kg, caffeine 100 mg, and
dextromethorphan 30 mg. MEASUREMENTS AND MAIN RESULTS: The pharmacokinetics of
antipyrine and its primary metabolites were determined from saliva and urine
samples. Type 1 diabetes had marked effects on antipyrine metabolism whereas type
2 disease did not alter the metabolism of any of the probe drugs. The apparent
oral clearance of antipyrine was increased 72% in patients with type 1 disease
compared with controls (p=0.0001). In addition, formation clearances of 4
hydroxyantipyrine and 3-hydroxymethylantipyrine were increased by 74% and 137% in
those patients relative to controls. The caffeine metabolic index
(paraxanthine/caffeine) was increased 34% (p=0.11), and N-acetylation and CYP2D6
phenotype were not altered. CONCLUSION: The metabolism of antipyrine is increased
in patients with type 1 diabetes. Based on in vitro reports of antipyrine
metabolism and current caffeine metabolic index data, the predominant effect of
type 1 diabetes appears to be an increase in CYP1A2 activity. Assessment of the
effect of the disease on other specific CYP metabolic pathways is warranted.
PMID- 10678297
TI - Quantification of human H1 histamine receptor mRNA from peripheral blood.
AB - STUDY OBJECTIVE: To develop a reverse transcription (RT)-polymerase chain
reaction (PCR) technique to detect and quantify human histamine1 (H1) receptor
mRNA in peripheral blood. METHODS: Primer pairs were based on the human H1
receptor nucleotide sequence. A competitive reference standard (CRS) was
developed that used the same primers as wild-type mRNA but contained a 92-bp
deletion. RT-PCR was performed with 5 microg of total RNA obtained from venous
blood of six subjects that was added to known concentrations of CRS RNA. Linear
regression comparing wild-type with CRS product was used to quantify wild-type
mRNA. MEASUREMENTS AND MAIN RESULTS: Three subjects had detectable H1 mRNA, with
a range of 31-435 pg. In three subjects PCR product was not detected, although
the presence of RNA was confirmed. Redesigned primer pairs showed mRNA to H1
receptor in two of the remaining subjects, but it was undetectable in the third.
CONCLUSION: RT-PCR can be used to detect and quantify human H1 receptor mRNA from
peripheral blood.
PMID- 10678298
TI - Increased therapeutic failure for cephalexin versus comparator antibiotics in the
treatment of uncomplicated outpatient cellulitis.
AB - We reviewed records of outpatients to determine the therapeutic failure rate of
cephalexin in treating uncomplicated cellulitis. Therapeutic failure was defined
as an increase in antibiotic dosage, prescription renewal, or addition or
substitution of another antibiotic. Demographics, physical characteristics, risk
factors, intervention, and outcome data were collected. Twenty-seven percent of
patients failed therapy with an oral antibiotic. The failure rate for cephalexin
was 40% versus 20% for comparator antibiotics (p=0.02, odds ratio [OR] 2.62, 95%
confidence interval [CI] 1.18-5.75). We identified no statistically significant
variables related to cephalexin failure. Concomitant acid suppressive therapy was
administered with cephalexin in 42% of failures and 20% of nonfailures (p=0.11,
OR 2.78, 95% CI 0.77-9.87). These data suggest that cephalexin's efficacy was
less than that of other antimicrobials in treating cellulitis, possibly related
to concurrent acid suppression.
PMID- 10678299
TI - A multidisciplinary renal clinic for corticosteroid-induced bone disease.
AB - A multidisciplinary clinic to manage complicated bone disease was established due
to the high prevalence of osteoporosis in corticosteroid-treated patients with a
history of organ transplantation or chronic glomerulonephritis. Assessments were
performed by a renal clinical pharmacist, nephrology nurse, and rheumatologist.
Of 70 patients (27 men, 43 women) evaluated from December 1997-June 1999, 37% had
osteoporosis (30% spine, 23% hip, 16% both sites) and 34% had a history of
fracture. Analysis revealed low 1,25-hydroxyvitamin D3 levels (15 patients),
hormone deficiency (16), elevated parathyroid hormone (27), and history of taking
at least one other risk drug in addition to corticosteroids (58). Thirty-nine
percent of patients had a documented height loss (mean 1.0 in.). Other risk
factors included 32 episodes of graft rejection requiring additional
corticosteroids, history of smoking (24 patients), poor physical activity (40),
and low dietary calcium intake (47). Drug interventions included calcium and/or
vitamin D (44 patients), calcitonin (7), alendronate (20), and hormone
replacement therapy (11). Preliminary results showed an increase in bone mineral
density (a surrogate marker for fracture risk) of 3-5%. An organized clinic to
assess osteoporosis risks can unmask a large population of patients with
documented bone loss. Appropriate interventions such as drug therapy and
lifestyle changes may increase bone mineral density. A long-term benefit of
therapy, although not measured in this study, may be a decreased predisposition
to fractures and their sequelae.
PMID- 10678300
TI - Impact of an indigent care program on use of resources: experiences at one
hospital.
AB - Thirty-six indigent patients hospitalized within 6 months of study initiation and
who met criteria were enrolled in a 6-month assistance program to determine if
provision of both medical care and prescription drugs at no cost would be
associated with a change in overall health care charges secondary to a change in
therapy adherence. A historical control group was identified. Charges for drugs
and medical care, and the number of hospitalizations and emergency room visits
were evaluated for comparison with the pretreatment period. Adherence to drug
regimens was measured using the Med-Out indicator. Inpatient admissions decreased
by 39.5% (from 43 to 26) and outpatient visits decreased by 64.4% (from 194 to
69). This amounted to a cost avoidance to the hospital of $378,183. The cost of
drugs during the study was $27,588. Patients who adhered to therapeutic regimens
provided an even greater cost avoidance.
PMID- 10678301
TI - A database analysis of potentially inappropriate drug use in an elderly medicaid
population.
AB - We conducted a cross-sectional retrospective review of 1996 Kentucky Medicaid
Pharmacy claims data to examine the prevalence of potentially inappropriate drug
use in 64,832 Medicaid recipients aged 65 years and older who received a
prescription. Twenty-seven percent of patients received at least one potentially
inappropriate agent. Prevalence was higher for nursing home residents (33%) than
for community dwellers (24%). Amitriptyline (7.6%), propoxyphene (6.5%), doxepin
(4.0%), and indomethacin (2.3%) were the most prescribed potentially
inappropriate agents. Education programs and interventions aimed at optimizing
the prescribing and dispensing of the most appropriate drugs are needed.
PMID- 10678302
TI - Phenytoin as a possible cause of acetaminophen hepatotoxicity: case report and
review of the literature.
AB - A 55-year-old woman was hospitalized for treatment of community-acquired
pneumonia. Unexplained, moderate elevations in hepatic transaminase and enzyme
levels prompted review of her drug regimen. She had taken acetaminophen 1,300
6,200 mg/day during the hospitalization. She also received phenytoin for
posttraumatic seizures. Acetaminophen was discontinued, and the patient's liver
chemistries returned to normal within 2 weeks of discharge. Acetaminophen is
metabolized in part by cytochrome P450 (CYP) 2E1, and inducers of CYP2E1 are
known to predispose patients to acetaminophen-related hepatotoxicity. Phenytoin
induces CYP2C and CYP3A4 isoforms, but not CYP2E1. The literature suggests,
however, that CYP3A4 may participate in acetaminophen metabolism to a greater
extent than previously realized, and induction of this isoform may predispose
patients to acetaminophen-induced hepatotoxicity.
PMID- 10678303
TI - Potentiation of oral anticoagulation and hemarthrosis associated with nabumetone.
AB - Concomitant therapy with warfarin and nonsteroidal antiinflammatory drugs
(NSAIDs) is of concern due to the potential for increased bleeding. Nonsteroidal
antiinflammatory drugs may alter patient response to warfarin by pharmacodynamic
or pharmacokinetic interactions. A man receiving long-term, stable warfarin
therapy experienced a significant increase in international normalized ratio 1
week after nabumetone was added to his regimen. Despite prompt reduction of the
warfarin dosage, he experienced hemarthrosis of his right knee. Previous reports
suggested lack of interaction between nabumetone and warfarin. Caution and close
monitoring are advisable when the two agents are administered concomitantly.
PMID- 10678304
TI - Epistaxis associated with elevation of INR in a patient switched to generic
warfarin.
AB - A 61-year-old man with atrial fibrillation receiving Coumadin brand warfarin was
switched to Barr brand warfarin without his knowledge as a result of a retail
pharmacy dispensing error. The patient took the same dosage for 6-7 days and
experienced severe epistaxis that required two visits to the emergency room.
Previously, his coagulation values were within therapeutic range, but when tested
at the emergency room the international normalized ratio was elevated. The
patient denied changes in therapy compliance, diet, alcohol ingestion, or use of
other drugs. His only other drug, taken periodically, was sildenafil for erectile
dysfunction. Clinicians should be aware of differences between branded and
generic compounds.
PMID- 10678305
TI - Psychiatric diagnosis in sociocultural context.
PMID- 10678306
TI - International systems of diagnosis in psychiatry.
AB - International standardization of diagnosis is the culmination of developments set
in motion in Europe during the first half of the 19th century. Its ultimate
rationale has been the science of descriptive psychopathology. The enterprise
implies that a common way of defining, describing, identifying, naming, and
classifying such disorders is possible and that a common system of psychiatric
diagnosis constitutes a first step toward dealing with them. Its natural science
approach implies that social and cultural factors are extraneous. Yet, as
discussed, the enterprise is based upon unique historical and cultural responses
to human behavioral individuality. Cultural aspects of psychiatric phenomena
create tensions in the application of the internationalist enterprise: Although
in theory applicable to all people regardless of populational/genetic, national,
or cultural background, it is used by clinicians of highly specific cultural
origin and in settings characterized by distinctive cultural traditions about
sickness, healing, nonsickness or health, and social behavior. Tensions created
by the international enterprise are discussed and illustrated by drawing
attention to how cultural factors impact on its basic assumptions and by a
selective review of literature.
PMID- 10678307
TI - Painful coitus: a review of female dyspareunia.
AB - The literature on female dyspareunia is reviewed with an emphasis on description
and classification, incidence and prevalence, etiological factors, and treatment
approaches. The research is found to be plagued with methodological problems and
characterized by a persistent dichotomization of issues into physiological and
psychological categories. A systematized and integrated approach to the study of
coital pain is proposed.
PMID- 10678308
TI - Visual hallucinations in patients from an ophthalmology clinic and medical clinic
population.
AB - Although visual hallucinations have been associated with patients with visual
disorders, no study has specifically examined whether visual hallucinations are
indeed more prevalent than in a general medical population. In this study, 127
consecutive visual disorder patients and 100 consecutive general medical patients
were screened for complex visual hallucinations. A total of 6.3% of visual
disorder patients and 2% of general medical patients had visual hallucinations.
Interestingly, the two medical patients with visual hallucinations also had
visual disorders. Factors significantly associated with visual hallucinations
were female sex (p = .029) and lower cognitive score (p = .001). Data from a
previous study of patients with the visual disorder age-related macular
degeneration were combined with this study to increase the sample size of visual
hallucinators. Factors significantly associated with visual hallucinations in the
combined sample were female sex (p = .015), living alone (p = .019), having
hearing problems (p = .047), older age (p = .013), and lower cognitive score (p <
.001). Implications and future research are discussed.
PMID- 10678309
TI - Longitudinal, expert, all data procedure for psychiatric diagnosis in patients
with psychoactive substance use disorders.
AB - The Longitudinal, Expert, All Data (LEAD) procedure has been proposed as a
criterion for the assessment of the procedural validity of diagnostic
instruments. The authors evaluated the procedure's test-retest reliability and
whether it enhanced diagnosis based on a single interview. Data were collected
using interviews and questionnaires to assess current and lifetime substance use
disorders and common comorbid disorders in 100 patients recruited from a
substance abuse treatment program. An initial diagnostic interview was conducted
by a primary expert who, at the end of treatment, formulated LEAD diagnoses for
each patient, based on the results of the research assessment and all available
clinical records. Secondary experts used a similar procedure in a subsample of 40
patients to provide a measure of test-retest reliability. Overall reliability of
LEAD diagnoses was good, though it varied from excellent for substance use
disorders to poor for some comorbid psychiatric disorders. As a consequence of
the LEAD procedure, the total number of substance use diagnoses increased
significantly, with no effect on diagnostic reliability. Based on these findings,
we conclude that, while the overall reliability of the LEAD procedure is
comparable to other diagnostic methods, there was considerable variability among
groups of diagnoses. The additional cost of the procedure would appear to be
justified only when diagnostic sensitivity is at a premium and principally for
the diagnosis of psychoactive substance use disorders. Before it is widely used
as a diagnostic criterion measure, the utility of the LEAD procedure should be
evaluated in a variety of patient samples and under varying circumstances.
PMID- 10678310
TI - A sibling study of sensation seeking and opiate addiction.
AB - Substance abuse and its correlative personality traits may have familial
associations. We assessed the relationship between sensation seeking and drug use
in 201 opiate addicts and 133 of their siblings in a cross-sectional family
study. Probands and their drug-abusing siblings showed greater sensation seeking
than their non-drug-abusing siblings and this diagnosis accounted for the most
variance in regression models. Degree of sensation seeking correlated among drug
abusing siblings and with age of first drug use. The results are discussed in
terms of substance abuse typologies and for using sensation-seeking assessments
for prevention and treatment of substance abuse.
PMID- 10678311
TI - Remission and relapse in subjects with panic disorder and panic with agoraphobia:
a prospective short-interval naturalistic follow-up.
AB - This article reports on the course of uncomplicated panic disorder and panic with
agoraphobia on 309 patients participating in the Harvard/Brown Anxiety Research
Project, a prospective longitudinal study of patients with DSM-III-R-defined
anxiety disorders. At 1 year, there was a .39 probability of full remission for
uncomplicated panic disorder and a .17 probability of full remission for panic
disorder with agoraphobia Similar differences in time to remission for these
syndromes were still found when criteria for remission were made less stringent.
However, even requiring less improvement for remission left a large percentage of
subjects in an episode, and for those that remitted, relapse occurred quickly,
indicating a chronic and recurrent course of illness. This is the first
longitudinal, prospective, naturalistic study on a large cohort of subjects with
anxiety disorders to have regular, structured, short-interval follow-up. Our
results are consistent with the view that panic disorder has a chronic course
with high rates of relapse after remission and longer episodes when agoraphobia
is a part of the constellation of symptoms.
PMID- 10678312
TI - A prospective, follow-along study of the course of social phobia: II. Testing for
basic predictors of course.
AB - This study examined the 65-week outcome of a group of subjects with social phobia
to determine predictors of course. Social phobic patients in the Harvard/Brown
Anxiety Disorders Research Project study were followed for 65 weeks using the
Longitudinal Interval Follow-Up Evaluation-UpJohn scale. The following variables
did not predict outcome over the course of the study: sex, age of onset, duration
of illness, lifetime history of various anxiety disorders, current comorbidity of
anxiety or depressive disorders, Global Assessment Scale score, or measures of
role functioning. We find that in a social phobic population with a mean duration
of illness of 18 years, none of the tested variables examined predicted 65-week
outcome.
PMID- 10678313
TI - Hyperreligiosity in psychotic disorders.
PMID- 10678314
TI - The heterogeneity of stealing behaviors in Chinese patients with anorexia nervosa
in Hong Kong.
PMID- 10678315
TI - Domains of psychopathology: an approach to the reduction of heterogeneity in
schizophrenia.
AB - The manifest clinical heterogeneity of schizophrenia, combined with the failure,
to date, to demonstrate the existence of a unitary disease process, has led to
the conceptualization of schizophrenia as a pathophysiologically heterogeneous
disorder. Various approaches have been developed to define homogeneous subgroups
of schizophrenic patients. An alternative approach to the use of multiple
criteria for defining putative disease entities is the use of specific sign and
symptom complexes, or domains of psychopathology, for reducing heterogeneity.
There is now considerable evidence supporting the separation of schizophrenic
symptoms into three domains: hallucinations and delusions, thought disorder, and
deficit symptoms. The conceptual evolution and validating evidence for this
approach are reviewed, and an illustration of how the domains of psychopathology
are applied in schizophrenia research is presented.
PMID- 10678316
TI - Application of artifical intelligence principles to the analysis of "crazy"
speech.
AB - Artificial intelligence computer simulation methods can be used to investigate
psychotic or "crazy" speech. Here, symbolic reasoning algorithms establish
semantic networks that schematize speech. These semantic networks consist of two
main structures: case frames and object taxonomies. Node-based reasoning rules
apply to object taxonomies and pathway-based reasoning rules apply to case
frames. Normal listeners may recognize speech as "crazy talk" based on violations
of node- and pathway-based reasoning rules. In this article, three separate
segments of schizophrenic speech illustrate violations of these rules. This
artificial intelligence approach is compared and contrasted with other
neurolinguistic approaches and is discussed as a conceptual link between
neurobiological and psychodynamic understandings of psychopathology.
PMID- 10678317
TI - Dissecting psychotic speech.
PMID- 10678318
TI - Metaphors and models in the neuropsychiatry of language.
PMID- 10678319
TI - Artificial intelligence and schizophrenic speech analysis.
PMID- 10678320
TI - The problem of missing clinical data for research in psychopathology: some
solution guidelines.
AB - There are no guidelines to help psychiatric researchers statistically adjust for
missing data. We discuss the problems resulting from missing values, and
illustrate some of them with examples from our work. Using structured
instruments, we obtained clinical information from 241 patients. Some instrument
items were not rated, and these did not occur randomly: hallucinations and
delusions were most frequently unrated, especially in chronic schizophrenics, and
patients with high scores for other psychopathology. Systematically assigning an
intermediate value between present and absent to nonrated items was a
satisfactory solution, unaffected by nonrandom missing values. This simple
solution was equivalent to a complicated one (vectoring) in discriminating
patients. When relationships between variables are linear, we recommend the
intermediate value method as a practical solution to missing values. We stress
that missing values do not mean missing information, and the most common response
to missing values (dropping subjects) is least informative.
PMID- 10678321
TI - Are there two depressive syndromes after stroke?
AB - The objective of this study was to describe the clinical characteristics of minor
depression after stroke and to compare this disorder with poststroke major
depression and the nondepressed state. Ninety-four stroke inpatients were
examined 8 weeks after stroke and reexamined 15 months later. Twenty-one (22%) of
the 94 patients suffered from minor depression, 14 (15%) suffered from major
depression, and 59 (63%) were not depressed. Minor depressed patients were twice
as symptomatic as nondepressed patients but were only half as symptomatic as
major depressed patients. Minor depressed patients were more likely than
nondepressed patients to have a previous history of stroke and were more
physically disabled. They were less likely than major depressed patients to have
a family history of affective disorder. Depression symptom severity was
associated with greater physical disability among minor but not major depressed
patients. Fewer minor than major depressed patients were depressed at 15 months.
These findings suggest that poststroke major and minor depression may be
different depressive syndromes. Some cases of minor depression may be construed
as an adjustment reaction to stroke disability.
PMID- 10678322
TI - Group differences in the relationship between apathy and depression.
AB - The purpose of this study was to evaluate the discriminability of apathy and
depression by determining whether the relationship of these two dimensions of
behavior varies in different diagnostic groups. Using the authors' Apathy
Evaluation Scale and the Hamilton Rating Scale for Depression, we rated 123
subjects, mean age 72 years, who met research criteria for healthy elderly
controls, left or right hemisphere stroke, probable Alzheimer's disease, and
major depression. Elevated apathy scores unassociated with elevated depression
were most frequent in Alzheimer's disease and right hemisphere stroke, and also
occurred in a small number of left hemisphere stroke and normal subjects. In
major depression, apathy was associated with high depression scores, although a
substantial number of major depressives showed elevated depression without
elevated apathy. In left hemisphere stroke, probable Alzheimer's disease, and
major depression, there were significant positive correlations between apathy and
depression. The slope of the regression of apathy on depression was greatest in
probable Alzheimer's disease and major depression. These results indicate that
the relationship between apathy and depression differs across diagnostic groups
and, thus, support the discriminability of apathy and depression.
PMID- 10678323
TI - Impulsivity scores in patients with obsessive-compulsive disorder.
PMID- 10678324
TI - Propranolol: a treatment for pseudoakathisia.
PMID- 10678325
TI - Monitoring chronic fatigue syndrome.
PMID- 10678326
TI - A case of posttraumatic stress disorder masked by pseudoseizures in a Jewish
Iranian immigrant in Israel.
PMID- 10678327
TI - Posttraumatic stress disorder and sociopolitical context: a comment.
PMID- 10678328
TI - Comparing buprenorphine and methadone maintenance.
PMID- 10678329
TI - Aspirin for atrial fibrillation.
PMID- 10678330
TI - Preventing stroke in patients with atrial fibrillation.
PMID- 10678331
TI - Bed rest ineffective as therapy.
PMID- 10678332
TI - Helicobacter pylori eradication for nonulcer dyspepsia is of limited value.
PMID- 10678334
TI - Interspeciality differences in medical resource utilization.
PMID- 10678335
TI - Physician satisfaction with Medicaid managed care: the Missouri experience.
AB - BACKGROUND: Medicaid managed care is important to health reform at the state
level. However, little is known about physician satisfaction with these programs.
We sought to measure this satisfaction in Missouri and determine its predictors.
METHODS: We surveyed a random sample of primary care physicians participating in
Medicaid managed care (n = 670) or traditional Medicaid (n = 670). Primary
outcomes measured were physicians' satisfaction Medicaid managed care,
traditional Medicaid and commercial managed care. Satisfaction was measured on a
5-point Likert-type scale. RESULTS: The response rate was 52%. Physicians
participating in Medicaid managed care were less likely to be satisfied or very
satisfied with Medicaid managed care (28.6%) than with commercial managed care
(40%) or their previous experience with traditional Medicaid (39.7%). Among
physicians participating in traditional Medicaid, 29.8% were satisfied or very
satisfied with traditional Medicaid. Physicians participating in Medicaid managed
care were less satisfied with clinical autonomy under that system in comparison
with their previous experience with traditional Medicaid (relative difference =
10.8%, P =.001). In multiple linear regression analyses, clinical autonomy (R2 =
0.40) was a strong predictor of overall satisfaction with Medicaid managed care.
CONCLUSIONS: Enhancing physicians' clinical autonomy may result in improved
satisfaction with Medicaid managed care. State Medicaid agencies should include
physician satisfaction as a measure of Medicaid managed care plans' quality.
PMID- 10678336
TI - A circle, broken.
PMID- 10678337
TI - Alcohol-related discussions in primary care: a report from ASPN. Ambulatory
Sentinel Practice Network.
AB - BACKGROUND: Problem drinking is common, and a 15-minute intervention can help
some patients reduce drinking to safe levels. Little is known, however, about the
frequency and duration of alcohol-related discussions in primary care. METHODS:
Nineteen clinicians in the Ambulatory Sentinel Practice Network (ASPN) collected
data about alcohol-related discussions for 1 week following their usual office
routine (Phase 1) and for 1 week with the addition of routine screening for
problem drinking (Phase 2). Of those, 15 clinicians collected data for a third
week after receiving training in brief interventions with problem drinkers (Phase
3). Clinicians collected data on standard ASPN reporting cards. RESULTS: In Phase
1 the clinicians discussed alcohol during 9.6% of all visits. Seventy-three
percent of those discussions were shorter than 2 minutes long, and only 10%
lasted longer than 4 minutes. When routine screening was added (Phase 2),
clinicians were more likely to discuss alcohol at acute-illness visits, but the
frequency, duration, and intensity of such discussions did not change. Only 32%
of Phase 2 discussions prompted by a positive screening result lasted longer than
2 minutes. After training, the duration increased (P <.004). In Phase 3, 58% of
discussions prompted by a positive screening result lasted longer than 2 minutes,
but only 26% lasted longer than 4 minutes. CONCLUSION: Routine screening changed
the kinds of visits during which clinicians discussed alcohol use. Training in
brief-intervention techniques significantly increased the duration of alcohol
related discussions, but most discussions prompted by a positive screening result
were still shorter than effective interventions reported in the literature.
PMID- 10678338
TI - Use of a high-sensitivity rapid strep test without culture confirmation of
negative results: 2 years' experience.
AB - BACKGROUND: Optimal diagnostic management of patients with pharyngitis is
controversial. In our study, we compared streptococcal complication rates at a
large suburban medical center during 2 time periods: when pharyngitis patients
were managed almost exclusively with throat culture and when they were managed
primarily with a high-sensitivity antigen test without culture confirmation of
negative results. METHODS: Using a combination of Current Procedural Terminology
and International Classification of Diseases, Ninth Revision codes, we studied
all patients seen for either pharyngitis or known streptococcal complications
during a 4-year period. We then reviewed all available charts of patients with
known streptococcal complications for coding accuracy. We compared streptococcal
complication rates during each -time period. RESULTS: A total of 30,036 patients
were seen for pharyngitis during the 4 years. A streptococcal diagnostic test was
used in 66% of patient encounters. During the first 2 years (period 1), 99.9% of
the tests ordered were blood agar plate throat cultures. During the second 2
years (period 2), 76.6% of tests ordered were high-sensitivity antigen tests
without culture confirmation of negative results. Suppurative complications
occurred in 37 patients in period 1 and 36 patients in period 2. There were no
cases of acute rheumatic fever in either period. There was one case of
poststreptococcal glomerulonephritis in period 2. CONCLUSIONS: Use of a high
sensitivity antigen test without culture confirmation of all negative results has
not been associated with an increase in suppurative and nonsuppurative
complications of group A beta-hemolytic streptococci.
PMID- 10678339
TI - The impact of regular vaginal pH screening on the diagnosis of bacterial
vaginosis in pregnancy.
AB - BACKGROUND: Bacterial vaginosis has recently been associated with preterm labor
and delivery. The purpose of our study was to determine whether regular prenatal
vaginal pH testing resulted in more frequent diagnoses of bacterial vaginosis and
other vaginal infections, more frequent treatment with antibiotics, and fewer
preterm deliveries. We also sought to determine the sensitivity and specificity
of pH testing and vaginal symptom reporting in identifying vaginal infections.
METHODS: Our study was a prospective clinical trial involving 121 pregnant women
randomized to receive either standard prenatal care, including routine inquiry
about vaginal symptoms, or standard care supplemented by vaginal pH testing.
Women with symptoms or a vaginal pH level >4.5 received a wet mount examination.
Confirmed infections were treated according to study protocols. RESULTS: Women
who received regular pH testing showed significantly higher detection rates for
bacterial vaginosis than controls (48.4% vs 27.1%, P =.015) and more frequent
detection of Trichomonas vaginalis (7.8% vs 1.7%, P = .116). A higher percentage
of women in the experimental group were treated for bacterial vaginosis and
trichomoniasis (46.9% vs 27.1%, P =.024), and the preterm birth rate was one half
that of the control group (4.7% vs 10.2%, P = .243). The presence of vaginal
symptoms or a vaginal pH level >4.5 identified bacterial vaginosis or
trichomoniasis with 84.4% sensitivity. CONCLUSIONS: In our study, frequent
vaginal pH testing during pregnancy resulted in more frequent diagnosis and
treatment of bacterial vaginosis. Since vaginal symptoms and elevated pH levels
appear to be useful in screening for bacterial vaginosis and trichomoniasis,
frequent pH testing should be evaluated in larger studies.
PMID- 10678340
TI - The evidence regarding the drugs used for ventricular rate control.
AB - OBJECTIVE: Our goal was to determine what drugs are most efficacious for
controlling the ventricular rate in patients with atrial fibrillation. SEARCH
STRATEGY: We conducted a systematic review of the literature published before May
1998, beginning with searches of The Cochrane Collaboration's CENTRAL database
and MEDLINE. SELECTION CRITERIA: We included English-language articles describing
randomized controlled trials of drugs used for heart rate control in adults with
atrial fibrillation. DATA COLLECTION/ANALYSIS: Abstracts of trials were reviewed
independently by 2 members of the study team. We reviewed English-language
abstracts of non-English-language publications to assess qualitative consistency
with our results. MAIN RESULTS: Forty-five articles evaluating 17 drugs met our
criteria for review. In the 5 trials of verapamil and 5 of diltiazem, heart rate
was reduced significantly (P <.05), both at rest and with exercise, compared with
placebo, with equivalent or improved exercise tolerance in 6 of 7 comparisons. In
7 of 12 comparisons of a beta-blocker with placebo, the beta-blocker was
efficacious for control of resting heart rate, with evidence that the effect is
drug specific, as nadolol and atenolol proved to be most efficacious. All 9
comparisons demonstrated good heart rate control with beta-blockers during
exercise, although exercise tolerance was compromised in 3 of 9 comparisons. In 7
of 8 trials, digoxin administered alone slowed the resting heart rate more than
placebo, but it did not significantly slow the rate during exercise in 4 studies.
The trials evaluating other drugs yielded insufficient evidence to support their
use, but those drugs may yet be promising. CONCLUSIONS: The calcium-channel
blockers verapamil or diltiazem, or select beta-blockers are efficacious for
heart rate control at rest and during exercise for patients with atrial
fibrillation without a clinically important decrease in exercise tolerance.
Digoxin is useful when rate control during exercise is less a concern.
PMID- 10678341
TI - Becoming an information master: using POEMs to change practice with confidence.
Patient-Oriented Evidence that Matters.
AB - Today's physicians are faced with identifying, evaluating, and applying a huge
quantity of medical information. In addition, many stakeholders in health care,
from patients to payers, are taking an active role in the previously inviolable
process of physician decision making. This is the third paper in a series
discussing the concept of information mastery. In the first paper we discussed
using the criteria for Patient-Oriented Evidence that Matters (POEMs) to distill
clinically relevant information. The second paper in the series focused on
techniques for efficiently obtaining this information from the myriad resources
available. In this paper we discuss the final step in the process, changing
practice habits after finding new information that necessitates it. We discuss
managing change, consider barriers, and present ideas to help with the process.
PMID- 10678342
TI - Depression diagnoses and antidepressant use in primary care practices: a study
from the Practice Partner Research Network (PPRNet).
AB - BACKGROUND: We examined the pharmacologic management and follow-up of adults with
newly diagnosed depression, and the use of antidepressants among patients not
diagnosed with depression in primary care practice. A total of 389 physicians in
39 practices in the Practice Partner Research Network (PPRNet), a national
network of primary care physicians provided data for the study. METHODS: We
performed a retrospective cohort study for the year 1996 using demographic,
contact, diagnosis, and prescription data available in the December 1997 PPRNet
database. We identified patients with new diagnoses of depression from the
problem lists in the electronic medical record. Psychopharmacologic agents
prescribed within 5 days of the diagnosis, follow-up contacts within 6 months of
the diagnosis, and diagnoses of patients prescribed antidepressants without a new
diagnosis of depression were also identified. We performed descriptive analyses
for all practices and for individual practices. RESULTS: During 1996, there were
149,327 active adult patients in the 39 participating practices. Of the 131,141
patients without a history of depression or antidepressant prescription, 2103
(1.6%) had a new diagnosis of depression in 1996. Incidence among the 39
practices ranged from 0.4% to 4.0%. Forty-nine percent of the newly diagnosed
patients received an antidepressant prescription within 5 days of diagnosis; 81%
of the prescriptions were for selective serotonin reuptake inhibitors. Ninety
percent of the patients prescribed antidepressants had at least one contact in
the 6 months after diagnosis (mean = 5.3 contacts). One third of the patients who
had not begun antidepressants within 5 days of their diagnoses started taking one
by the end of 1996. Among the 149,327 active patients, 6.3% received a
prescription for an antidepressant in 1996. More than 40% of these patients had
never been diagnosed with depression. CONCLUSIONS: Our study highlights the high
prevalence and wide interpractice variations of diagnosing depression and
prescribing antidepressants in primary care. Follow-up of patients newly
diagnosed with depression was common and consistent with published guidelines.
Opportunities for increased detection and treatment of depression exist in
approximately half of the study practices.
PMID- 10678343
TI - High prevalence of overweight children in Michigan primary care practices. An
UPRNet study. Upper Peninsula Research Network.
AB - BACKGROUND: Our goal was to determine whether the prevalence of obesity in
children who receive care in Michigan primary care practices is greater than
national and state prevalences. METHODS: We compared prevalences of overweight
children and adolescents in primary care practices with the results of the
National Health Examination Survey (NHES), the National Health and Nutrition
Examination surveys, and a contemporary survey of Michigan schoolchildren. We
collected data from 19 rural family practice offices and 2 urban clinics. We
measured the heights and weights of 993 consecutive patients aged 4 to 17 years
who visited one of the participating practices during the spring of 1996.
RESULTS: Obesity prevalences were the main outcome measure. Of the boys, 38% were
above the 85th percentile of the NHES, and 16% were above the 95th percentile. Of
the girls, 33% were above the 85th percentile, and 13% were above the 95th
percentile. Prevalences of obesity were much higher among the primary care
patients than in the results of the national surveys and the contemporary
Michigan schoolchildren survey. CONCLUSIONS: The prevalences of obesity for
children and adolescents presenting for care in Michigan primary care practices
are higher than the prevalences documented in state and national surveys. A
larger systematic study is needed to confirm or refute these findings. If this
prevalence of obesity in primary care patients is confirmed, explanations for the
differences should be explored.
PMID- 10678344
TI - Helicobacter pylori eradication does not improve symptoms of nonulcer dyspepsia.
PMID- 10678345
TI - Neuroleptics for behavioral symptoms of dementia.
PMID- 10678346
TI - Treating carpal tunnel syndrome.
AB - BACKGROUND CTS is a common problem caused by compression of the median nerve at
the wrist resulting in hand numbness, loss of dexterity, muscle wasting, and
decreased functional ability at work. This study investigated the efficacy of a
corticosteroid injection just proximal (not into) the carpal tunnel for CTS.
POPULATION STUDIED: Study participants included 60 patients referred to a
neurology clinic in Amsterdam, Netherlands, with CTS symptoms for longer than 3
months' duration and confirmed with electrophysiological tests. Patients in the
intervention and control groups had symptoms for an average of 32 months and 25
months, respectively. In patients with bilateral symptoms, the arm with the most
severe symptoms was chosen for randomization. Patients aged younger than 18 years
and those who had previous treatment for CTS were excluded. STUDY DESIGN AND
VALIDITY: Patients were randomized to receive an injection of either lignocaine
(Lidocaine 10 mg) and methylprednisolone 40 mg or a lignocaine 10-mg injection
only. The site of injection was proximal to the carpal tunnel on the volar side
of the forearm 4 cm proximal to the wrist crease, between the tendon of the
radial flexor muscle and the long palmar muscle. Injections were given at a 10
degrees to 20 degrees angle with a 3-cm needle. At baseline, there were no
significant differences between the control group and the intervention group. The
study was performed at one clinic where one neurologist performed all injections.
Thus, we do not know if the results of this technique can be consistently
reproduced. No patients were reported lost to follow-up at 1 year. To ensure
blinding of the treatment assignment, a pharmacist wrapped the syringes in paper
and a second neurologist performed outcomes assessment interviews. One month
after the initial injection, patients were asked whether they had no symptoms or
only minor symptoms that they considered so much improved that they felt no
further treatment was necessary. Investigators broke the trial code at follow-up
assessment visits to offer nonresponders an injection with methylprednisolone or
surgery. OUTCOMES MEASURED: Patients were considered improved if they self
reported no symptoms or only minor symptoms needing no additional treatment.
Other symptoms (weakness, nighttime pain) or impact on lifestyle and occupation
were not reported. RESULTS: At 1 month, 20% of the patients in the control group
had improved compared with 77% of patients in the intervention group (P <.001;
number needed to treat = 1.8). After 1 year, 8 of the 23 patients (35%) who
initially responded to methylprednisolone required a second injection. A total of
86% of nonresponders in the control group improved after receiving a
methylprednisolone injection, but 50% of these patients went on to need surgical
treatment within 1 year. The investigators reported no side effects to the
injection.
PMID- 10678347
TI - Treatment modalities for primary basal cell carcinomas.
PMID- 10678348
TI - The hidden value of primary care.
PMID- 10678349
TI - Treatment of influenza.
PMID- 10678350
TI - Targeting gene expression to tumor cells with loss of wild-type p53 function.
AB - The tumor suppressor protein p53 is a transcription factor that can positively
regulate the expression of critical target genes involved in negative control of
cell growth or induction of apoptosis; p53 is also able to suppress the
transcription of other genes by virtue of its ability to bind components of the
basal transcription machinery. Over 50% of human tumors are characterized by p53
mutations that result in a loss of wild-type p53 (wtp53) function in the
transcriptional control of these target genes. We have exploited this loss of p53
function in the regulation of gene transcription to develop a novel gene therapy
strategy that maximizes expression of the potential therapeutic gene in tumors
while simultaneously down-regulating the same gene in normal cells. In one
construct (unit I), the potential therapeutic gene (in this case represented by a
luciferase reporter) is placed under the control of a promoter such as the heat
shock protein 70 gene promoter, which is repressed by wtp53 but overexpressed in
many tumor cells with defective p53 function. Residual expression of the reporter
in normal cells is repressed by cotransfection of another construct (unit II)
consisting of a repressor of unit I under the control of a promoter that is
activated by wtp53 expression. Unit II contains a promoter with a consensus wtp53
binding site driving a transcriptional repressor or an antisense construct for
the gene in unit I. Our results suggest that this dual control approach may
represent a strategy with wide applications in the field of cancer gene therapy.
PMID- 10678351
TI - Modifications of the fiber in adenovirus vectors increase tropism for malignant
glioma models.
AB - Recombinant adenovirus (Ad) vectors provide a means of local, therapeutic gene
delivery to a wide range of neoplasms. Ad-mediated gene therapy trials in
malignant glioma models have been limited by the need for high viral titers and
multiple dosages. In an attempt to improve Ad vector gene transfer, we studied
human (U87, D54) and rodent (GL261, C6) malignant glioma cell lines transfected
with various doses of unmodified Ad vectors (AdZ), Ad vectors that contain an
alteration of the fiber-coat protein and that direct virus binding to heparan
sulfate receptors (AdZ.F(pK7)), and Ad vectors with modifications of the fiber
coat protein that direct virus binding to alpha1, integrin cellular receptors
(AdZ.F(RGD)). AdZ.F(pK7) increased the frequency of cells expressing the reporter
gene, beta-galactosidase, and improved transduction by 2- to 20-fold compared
with AdZ in U87, D54, and GL261 cells. In U87, D54, GL261, and C6 tumors,
AdZ.F(pK7) increased gene transfer by 10- to 100-fold compared with AdZ.
AdZ.F(RGD) increased gene expression in C6 xenografts compared with AdZ, but had
reduced transduction compared with the C6 xenografts of AdZ in all other glioma
tumors. These findings suggest that the increased tropisms resulting from
alterations of the Ad vector fiber-coat protein as in AdZ.F(pK7) and AdZ.F(RGD)
offer a feasible approach to improving in vitro and in vivo transduction
efficiencies in certain malignant glioma cell lines.
PMID- 10678352
TI - Cytosine deaminase suicide gene therapy for peritoneal carcinomatosis.
AB - Gene therapy is a novel therapeutic approach that might soon improve the
prognosis of some cancers. We investigated the feasibility of cytosine deaminase
(CD) suicide gene therapy in a model of peritoneal carcinomatosis. DHD/K12
colorectal adenocarcinoma cells transfected in vitro with the CD gene were highly
sensitive to 5-fluorocytosine (5-FC), and a bystander effect could also be
observed. Treating CD+ cells with 5-FC resulted in apoptosis as detected by
terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick-end
labeling. In vitro, several human cell lines derived from ovarian or colorectal
carcinomas, as well as the rat glioblastoma 9 L cell line, responded to CD/5-FC
and showed a very strong bystander effect. 5-FC treatment of peritoneal
carcinomatosis generated in syngeneic BDIX rats by CD-expressing DHD/K12 cells
led to a complete and prolonged response and to prolonged survival. Our study
thus demonstrated the efficacy of CD suicide gene therapy for the treatment of
peritoneal carcinomatosis.
PMID- 10678353
TI - Highly efficient suicide gene expression in hepatocellular carcinoma cells by
epstein-barr virus-based plasmid vectors combined with polyamidoamine dendrimer.
AB - The present study was aimed at devising an efficient nonviral strategy for
suicide gene therapy of hepatocellular carcinoma (HCC). To improve the efficiency
of DNA delivery and expression, we applied Epstein-Barr virus (EBV)-based plasmid
vectors instead of conventional plasmid vectors and combined them with cationic
liposome (EBV/lipoplex) or polyamidoamine dendrimer (PAAD) (EBV/polyplex). When
the beta-galactosidase gene was transferred to HuH7, PLC/PRF/5, or HLE cells, <
or =50-fold higher beta-galactosidase activities were demonstrated in the cells
transfected with EBV vector compared with those transfected with conventional
plasmid vectors. PAAD-mediated transfection of HCC with pSES.Tk (an EBV-based
vector carrying the herpes simplex virus-1 thymidine kinase gene) resulted in a
marked reduction in viable cell number by the addition of ganciclovir (GCV). The
HCC cells transfected with pSES.Tk/PAAD showed 100- to 1000-fold higher
susceptibilities to GCV than those transfected with pS.Tk (a conventional plasmid
vector carrying herpes simplex virus-1 thymidine kinase gene)/PAAD. The pSES.Tk
transfected HCC cells were effectively killed by day 9 in culture with a
clinically feasible concentration of GCV (25 microM), whereas the pS.Tk
transfected cells survived the culture. These results demonstrate highly
efficient suicide gene transfer into various HCC cells by EBV-based plasmid
vectors in vitro, suggesting the possible application of this nonviral vector
system to gene therapy of HCC.
PMID- 10678354
TI - Adenoviral transfer of xenogeneic MHC class I gene results in loss of
tumorigenicity and inhibition of tumor growth.
AB - The immune system confers protection against a variety of pathogens and
contributes to the destruction of neoplastic cells. Foreign major
histocompatibility complex (MHC) protein serves as a potent stimulus to the
immune system. In this report, a mouse H-2Kb gene was introduced into two poorly
immunogenic tumor cell lines, a mouse colonic carcinoma cell line, MCA-26 (H
2Kd), and a rat mammalian carcinoma cell line, LN-4, in an effort to stimulate
tumor rejection. Our results showed that the expression of xenogeneic MHC class I
antigen completely abolished the LN-4 tumorigenicity in rats, whereas the
expression of allogeneic MHC class I antigen only partially reduced the MCA-26
tumorigenicity in mice. Rats with tumor regression of LN-4/H-2Kb developed a T
helper type 1-dominant response, whereas rats with LN-4 tumor growth developed a
T helper type 2-dominant response. The immunized rats that experienced LN-4/H-2Kb
tumor regression further developed protective immunity against a subsequent
challenge of LN-4 cells. This protective immunity was mediated by the LN-4 tumor
specific cellular immune response against both the transduced and the parental LN
4 cells. Recombinant adenoviral vectors are highly efficient at in vitro and in
vivo gene delivery. The LN4 cells transfected with the recombinant adenovirus AdV
H-2Kb in vitro expressed the cell surface H-2Kb molecule by fluorescence
activated cell sorter analysis. Adenovirus-mediated H-2Kb gene transfer in vivo
can further significantly inhibit pre-established LN-4 tumors. Those rats with
complete tumor regression further developed protective immunity against the
subsequent challenge of a parental LN-4 tumor. Therefore, our study indicates
that the adenovirus-mediated transfer of xenogeneic MHC class I gene may be an
effective alternative to the current protocol of cancer gene therapy in which the
allogeneic MHC class I gene is used.
PMID- 10678355
TI - Potentiation of ganciclovir toxicity in the herpes simplex virus thymidine
kinase/ganciclovir administration system by ponicidin.
AB - The herpes simplex virus thymidine kinase (HSV-TK)/ganciclovir (GCV)
administration system is commonly used in gene therapy trials. We have evaluated
the effect of ponicidin, a diterpenoid isolated from a plant, Rabdosia
ternifolia, on the cell-killing activity of the anti-herpes drugs acyclovir (ACV)
and GCV. Ponicidin preferentially activated HSV-1-specific TK but not cellular
kinases. In HSV-infected cells, ponicidin significantly accumulated the
phosphorylated metabolites of GCV and suppressed the extracellular release of
GCV. These data suggested that the cytotoxicities of ACV and GCV in HSV-TK
expressing cells might be potentiated by ponicidin. After transfected with the
HSV-1 TK gene, COS-1 and several human cancer cells became highly sensitive to
the cytotoxic properties of the nucleoside analogs. When ponicidin at the
concentration without antiviral activities (0.2 microg/mL) was combined with ACV
or GCV, the cytotoxic levels in HSV-TK-expressing cells were enhanced by 3- to 87
fold and 5- to 52-fold, respectively, compared with the nucleoside alone. When
the stability of the bioactivity of ponicidin in the blood of mice was evaluated,
the substance showed relatively long-lasting effects on the potentiation of the
anti-herpetic and cytotoxic activities of GCV after intravenous administration.
These data suggest that the combined use of ponicidin with GCV will be effective
for cancer gene therapy, because high cytotoxicity in viral TK-expressing cells
should yield more rapid and enhanced tumor elimination.
PMID- 10678356
TI - Fusogenic effects of murine retroviruses and cationic enhancers of transduction.
AB - The maturation of retrovirus particles involves proteolytic cleavage of the
envelope glycoprotein transmembrane component, resulting in conversion of the
virus particle to a fusogenic or infectious state. Susceptible murine cells
exposed to virus-containing supernatants from ecotropic retroviral helper cells
occasionally fused to neighboring cells, resulting in syncytia (giant cells with
multiple nuclei). Polycationic molecules dramatically enhanced the effect,
leading to widespread cell death. The degree of cell fusion was dependent upon
the retroviral envelope subtype (ecotropic-->amphotropic, gibbon ape leukemia
virus was negative) as well as on the polycationic reagent used (G9 dendrimer-
>Lipofectamine-->polybrene). Cell fusion effects were not mediated by the
retroviral vector backbone, because virus-containing supernatants from helper
cells (without vector) and vector producer cells had a similar effect. Human
target cells were not fused by any type of murine retrovirus; in addition,
amphotropic virus from human helper cells was not fusogenic toward murine cells.
Thus, fusogenic effects were important during the propagation of vectors using
murine helper cells but were not a significant factor during the transduction of
human cells.
PMID- 10678357
TI - Effects of epidermal growth factor, transferrin, and insulin on lipofection
efficiency in human lung carcinoma cells.
AB - Poor transfection efficiency is the major drawback of lipofection. We showed
previously that addition of transferrin (TF) to Lipofectin enhanced the
expression of a reporter gene in HeLa cells by 120-fold and achieved close to
100% transfection efficiency. The purpose of this study was to determine whether
TF and other ligands could improve the efficiency of lipofection in lung
carcinoma cells. Confluent A549, Calu3, and H292 cells were transfected for 18
hours with a plasmid DNA (pCMVlacZ) using Lipofectin plus TF, insulin, or
epidermal growth factor as the vector. The transfected cells were assessed for
transfection efficiency by beta-galactosidase activity (light units/microg
protein) and the percentage of blue cells following 5-bromo-4-chloro-3-indolyl
beta-D-galactopyranoside staining. Lipofectin supplemented with epidermal growth
factor yielded the largest enhancement of lipofection efficiency (< or =23-fold
over that by Lipofectin alone) in all three cell lines. Insulin significantly
enhanced the lipofection efficiency in A549 and Calu3 cells but not in H292
cells, whereas TF showed significant lipofection efficiency-enhancing effect in
Calu3 and H292 cells but not in A549 cells. The transfection efficiency
correlated well with the amounts of DNA delivered to the nucleus as well as the
amounts of the receptor. These results indicate that the gene delivery strategy
employing ligand-facilitated lipofection can achieve high transfection efficiency
in human lung carcinoma cells. In addition, enhancement of the expression of the
receptor may be a possible strategy for increasing the efficiency of gene
targeting.
PMID- 10678358
TI - Vaccinia as a vector for tumor-directed gene therapy: biodistribution of a
thymidine kinase-deleted mutant.
AB - Tumor-directed gene therapy, such as "suicide gene" therapy, requires high levels
of gene expression in a high percentage of tumor cells in vivo to be effective.
Current vector strategies have been ineffective in achieving these goals. This
report introduces the attenuated (thymidine kinase (TK)-negative) replication
competent vaccinia virus (VV) as a potential vector for tumor-directed gene
therapy by studying the biodistribution of VV in animal tumor models. A TK
deleted recombinant VV (Western Reserve strain) expressing luciferase on a
synthetic promoter was constructed. Luciferase activity was measured in vitro
after transduction of a variety of human and murine tumor cell lines and in vivo
after intraperitoneal (i.p.) delivery in C57BL/6 mice with 7-day i.p. tumors
(10(6) MC-38 cells). Three other in vivo tumor models were examined for tumor
specific gene expression after intravenous delivery of VV (human melanoma in nude
mice, adenocarcinoma liver metastasis in immunocompetent mice, and subcutaneous
sarcoma in the rat). In addition, a replication-incompetent vaccinia (1 microg of
psoralen and ultraviolet light, 365 nm, 4 minutes) was tested in vitro and in
vivo and compared with active virus. Luciferase activity in i.p. tumors at 4 days
after i.p. injection of VV was >7000-fold higher than lung, >3000-fold higher
than liver, and >250-fold higher than ovary. In addition, intravenous injection
of VV resulted in markedly higher tumor luciferase activity compared with any
other organ in every model tested (up to 188,000-fold higher than liver and
77,000-fold higher than lung). Inactivation of the virus resulted in negligible
gene expression in vivo. In summary, VV has a high transduction efficiency in
tumor cells with high levels of gene expression. The results suggest a selective
in vivo replication of TK-deleted VV in tumor cells. Replication competent, TK
deleted VV appears to be an ideal vector for testing the in vivo delivery of
toxic genes to tumor cells.
PMID- 10678359
TI - In vivo efficacy and toxicity of 5-fluorocytosine/cytosine deaminase gene therapy
for malignant gliomas mediated by adenovirus.
AB - We evaluated the therapeutic efficacy and neurotoxicity of adenovirus-mediated
transduction of the cytosine deaminase (CD) gene and 5-fluorocytosine (5-FC) for
experimental malignant brain tumors. The 5-FC sensitivity in 9 L cells infected
by an adenovirus vector expressing CD (AdexCACD) was increased 1700-fold compared
with control cells. Rats bearing 9 L brain tumors were treated with an
intratumoral injection of AdexCACD followed by intraperitoneal administration of
5-FC. The rats demonstrated remarkable inhibition of tumor growth by magnetic
resonance imaging, and 7 of 10 rats survived for >90 days. To evaluate the
potential side-effects of the 5-FC/CD gene therapy, rats were treated with an
intracerebral injection of AdexCACD into the right basal ganglia and with 5-FC.
The magnetic resonance imaging showed a highly enhanced area on the gadollinium
enhanced T1-weighted image at 18 days postinjection. Pathologically, this
corresponded to an area of necrosis with surrounding apoptotic cells. In
addition, there was demyelination and gliosis with enlargement of the lateral
ventricles. These results suggest that the 5-FC/CD gene therapy may provide an
anticancer effect for malignant brain tumors in humans, but also show that there
are neurotoxic effects on normal brain tissue.
PMID- 10678360
TI - Effectiveness of cancer vaccine therapy using cells transduced with the
interleukin-12 gene combined with systemic interleukin-18 administration.
AB - We introduced the interleukin-12 (IL-12) gene into mouse renal cell carcinoma
(RenCa) cells to develop a tumor vaccine and to examine mechanisms of tumor
rejection. IL-12-secreting RenCa (RenCa/IL-12) cells were completely rejected
when implanted into syngeneic BALB/c but not athymic nude mice, suggesting that T
cells were involved in this antitumor effect. Depletion of natural killer (NK)
cells in nude mice did not affect the tumor growth of RenCa/IL-12. The
simultaneous injection of mitomycin C-treated RenCa/IL-12 inhibited the tumor
growth of parental RenCa injected at a distant site, whereas injection of
mitomycin C-treated parental RenCa did not. The antitumor effect of RenCa/IL-12
as a cancer vaccine was induced by CD8+ T cells and NK cells and was inhibited by
CD4+ T cells. Although the systemic administration of recombinant IL-18 (rIL-18)
alone did not inhibit the tumor growth, it did enhance the cancer vaccine effect
of RenCa/IL-12. The combination therapy of RenCa/IL-12 and the systemic
administration of rIL-18 retarded even the growth of established tumors. The
effector cells of this combination therapy consist not only of CD8+ T cells and
NK cells but also of CD4+ T cells. This synergistic cancer vaccine effect of in
situ secretion of IL-12 and the systemic administration of rIL-18 may be
attributed to a functional change of CD4+ T cells.
PMID- 10678361
TI - Attenuating the growth of tumors by intratumoral administration of DNA encoding
Pseudomonas exotoxin via cationic liposomes.
AB - A gene therapy approach was taken to inhibit tumor growth by transfecting tumor
cells with a plasmid encoding a truncated but active form of Pseudomonas exotoxin
A (PE), using cationic lipids as the transfection reagent. Cells transfected with
this plasmid express PE intracellularly and undergo apoptosis. Transfection was
optimized in vitro using two cationic lipids, DOGS and DOSPER. A ratio of between
1:4 and 1:10 (wt/wt) was found to be optimal for DOSPER, and the ratio 1:4 was
used for the in vivo study when a smaller injection volume was desired.
Estimating the activity of the PE-encoding plasmid was done both directly, by
counting cells in vitro after transfection, and by using a cytotoxicity assay,
and indirectly, by cotransfecting the plasmid with a plasmid carrying a reporter
beta-galactosidase gene and observing a reduction in beta-galactosidase activity
with increasing amounts of the PE-encoding plasmid. The cotransfection method was
found to be very sensitive, and showed transfection of cells even with 1-2 ng of
the PE-encoding plasmid per 10(5) cells. Complexes of the PE-encoding plasmid
together with cationic lipid were injected into tumor xenografts in athymic nude
mice. The tumor growth of transfected tumors was attenuated compared with control
untreated tumors or tumors transfected with a nontoxin-expressing vector. These
results indicate the potential of such a treatment for attenuating solid tumor
growth in vivo.
PMID- 10678362
TI - The nitroreductase/CB1954 combination in Epstein-Barr virus-positive B-cell
lines: induction of bystander killing in vitro and in vivo.
AB - Epstein-Barr virus (EBV)-based gene delivery vectors that preferentially express
toxic genes in EBV-infected cells could be used to target EBV-positive tumors for
destruction. We have shown previously that the cytosine deaminase (CD) enzyme,
which converts the prodrug 5-fluorocytosine (5-FC) into the toxic compound 5
fluorouracil efficiently kills EBV-positive cells in the presence of 5-FC, with a
substantial bystander killing effect in vitro and in vivo. To identify the
optimal enzyme/prodrug combination for treating EBV-positive lymphomas, we have
compared the effectiveness of the CD/5-FC combination with the nitroreductase
(NTR)/CB1954 combination for killing EBV-positive B-cell lines. NTR metabolizes
CB1954 into an alkylating agent that cross-links DNA. When the CD gene or the NTR
gene were transfected into two different EBV-positive B-cell lines in vitro,
approximately 90% of cells were killed in a prodrug-dependent manner, although
the transfection efficiency was <5%. However, severe combined immunodeficient
mouse tumors containing either 30% or 100% of NTR-expressing Burkitt lymphoma
(Jijoye) cells were growth inhibited, but not cured, by treatment with
intraperitoneal CB1954 (20 mg/kg/day) for 10 days. These results suggest that the
NTR/CB1954 combination induces efficient bystander killing of EBV-positive B-cell
lines in vitro but may not be as effective as the CD/5-FC combination for
treating B-cell lymphomas in vivo.
PMID- 10678363
TI - Comparison of the genotoxic and apoptosis-inducing properties of ganciclovir and
penciclovir in Chinese hamster ovary cells transfected with the thymidine kinase
gene of herpes simplex virus-1: implications for gene therapeutic approaches.
AB - We studied the genotoxic and apoptosis-inducing properties of ganciclovir (GCV)
and penciclovir (PCV) using Chinese hamster ovary cells stably transfected with
the thymidine kinase (tk) gene of herpes simplex virus-1 (HSV-1). Cells
expressing HSVtk were 300 and 100 times more sensitive than their isogenic HSVtk-
counterparts to the cytotoxic effects of GCV and PCV, respectively. Using
radiolabeled drugs, GCV was found to be incorporated into the genomic DNA much
more effectively than PCV. GCV was highly potent in inducing chromosomal
aberrations compared with PCV, which provoked less sister chromatid exchanges and
chromosomal changes using equimolar or equitoxic doses. For both agents,
apoptosis was shown to be the major route of cell killing. Time course
experiments revealed that neither genotoxicity nor apoptosis were induced within
the cell cycle exposed to the drug; they are late events provoked in the
following cell cycle(s). This indicates that the incorporation/exposure step of
GCV or PCV into DNA is not decisive for triggering genotoxicity and apoptosis,
but that events occurring subsequently, presumably during replication of a DNA
containing the nucleotide analogs, are of major importance. Because PCV, unlike
GCV, induced highly effectively apoptosis without exerting much genotoxicity, the
use of PCV as a relatively safe alternative drug for suicide gene therapy of
malignant diseases is recommended.
PMID- 10678364
TI - Purified herpes simplex thymidine kinase retroviral particles. II. Influence of
clinical parameters and bystander killing mechanisms.
AB - High-titer, purified herpes simplex virus thymidine kinase (HSV-TK) retroviral
particles, followed with intraperitoneal ganciclovir (GCV) were tested in Fischer
rats bearing 1-week established 9L gliosarcomas. 9L cells were infused
intracranially through a cannula on day 0, given intracranial infusions of HSV-TK
retroviral particles on days 7-12, and given 5 or 10 daily doses of
intraperitoneal GCV starting at day 14. Tumor volumetric studies performed on rat
brains at day 26 after tumor infusion revealed significant differences in
experimental groups receiving HSV-TK retroviral particles plus 10-day GCV or the
100% transduced 9L-TK group receiving GCV versus control groups treated with
either buffer, HSV-TK vector, or either 5- or 10-day regimens of GCV alone. The
duration of GCV administration and the volume of tumor burden influenced
efficacy. Adjuvant dexamethasone did not significantly affect efficacy.
Experiments in which 9L rechallenge of animals treated with 9L-TK/GCV or 9L
tumors treated with HSV-TK vector/GCV indicated that a host immune response was
involved in rejecting the rechallenge tumor. Outcome was dependent upon the site
and size of the rechallenge inoculum. In vitro, bystander effects were
significant but were especially marked when cell-to-cell contact was maintained.
Cumulatively, the data indicate that both the bystander effect and the host
immune response are responsible for the efficacy observed in the suicide gene
therapy paradigm using purified HSV-TK retroviral particles and GCV to treat
smaller tumor burden in rats with 9L gliosarcoma.
PMID- 10678365
TI - Ligand-mediated cytolysis of tumor cells: use of heregulin-zeta chimeras to
redirect cytotoxic T lymphocytes.
AB - New specificities may be engrafted onto lymphocytes by the transfer of genes for
chimeric receptors that combine antigen recognition and signal-transducing
elements. We have engineered and evaluated a new class of chimeric receptors that
use the natural ligands of receptors found to be frequently overexpressed by
cancer cells. The heregulin molecule, a ligand for Her3 and Her4 receptors when
fused with the CD3 zeta-chain, was capable of redirecting T lymphocytes to
recognize and respond to cancer cell lines that overexpress these receptors.
Thus, CD8+ T lymphocytes were isolated from a healthy individual and transduced
to express the chimeric heregulin-zeta receptor. These modified effector cells
acquired the ability to specifically lyse a breast cancer cell line that
overexpresses Her3 and Her4. A new class of chimeric receptors, such as heregulin
zeta, endowing anti-cancer effector cells with the potential to recognize and
eliminate tumor targets, are likely to increase the effectiveness of adoptive
immunotherapy for the treatment of cancer.
PMID- 10678366
TI - Development of a murine orthotopic model of leukemia: evaluation of TP53 gene
therapy efficacy.
AB - The onco-suppressor gene TP53 has potential use in the gene therapy of many human
cancers including leukemias. The latter indication derived from numerous
experimental reports of p53-mediated suppressing effects on human and murine
leukemia cells in vitro. However, few in vivo experiments have been performed,
and those that have used a subcutaneous injection of p53-transduced leukemia
cells. Thus, we developed an orthotopic leukemia model in adult, syngenic mice to
evaluate the feasibility of TP53-mediated therapeutic approaches. We found that
among other cells, v-src-transformed 32D myeloid progenitors induce leukemia when
injected intravenously in syngenic mice. The resulting malignancy resembles the
clinical manifestations of human acute myeloid leukemia because it is
characterized by a massive invasion of bone marrow compartments, splenomegaly,
generalized lymphadenopathy, and a macroscopic or microscopic infiltration of the
kidneys, liver, and lungs. When these 32Dv-src cells were infected with a TP53
recombinant retrovirus before intravenous injection, we found a decreased
mortality and, in those animals that develop leukemia, a drastic reduction of the
generalized organ infiltration, suggesting that exogenous TP53 expression might
be used for ex vivo bone marrow purging from leukemia cells.
PMID- 10678367
TI - Immunogene therapy against mouse leukemia using B7 molecules.
AB - B7 costimulatory molecules play an important role in T-cell activation. It is
well known that tumor cells that express B7 molecules can elicit antitumor
immunity, but little is known regarding which B7 molecule, B7-1 (CD80) or B7-2
(CD86), can do so more efficiently. To address this issue, we have introduced B7
1 or B7-2 into 8709 cells, a radiation-induced mouse myelocytic leukemic cell
line, and have compared their potentials regarding the induction of antitumor
immunity. Either B7-1- or B7-2-transduced monoclonal sublines, 8709/B7-1 or
8709/B7-2, respectively, diminished tumorigenicity in syngeneic C3H mice. Some
reports have indicated that B7-1 is superior to B7-2 in the induction of
antitumor immunity. Contrary to these results, the 8709/B7-2 lines are superior
to the 8709/B7-1 lines in their capacity to induce antitumor immunity. In vivo
depletion of lymphocyte subsets demonstrated that both CD4+ and CD8+ T cells were
indispensable for B7-1- or B7-2-dependent antitumor immunity, whereas natural
killer cells were not. These results suggest that in some circumstances, B7-2
molecule is more effective than B7-1 molecule in eliciting antitumor immunity.
PMID- 10678368
TI - Tetracycline-induced expression of an anti-c-Myb single-chain antibody and its
inhibitory effect on proliferation of the human leukemia cell line K562.
AB - Ablation of c-Myb function might be an effective approach for the therapy of
chronic myelogenous leukemia or other c-myb-dependent malignancies. To this end,
we have previously used an intracellular anti-c-Myb single-chain antibody (sFv)
to achieve the functional knockout of the c-Myb oncoprotein. In this study, we
have employed a tetracycline-inducible system to control the expression of the
sFv. A nuclear-localizing form of an anti-c-Myb sFv was cloned into a tet
regulated plasmid vector. Using a transient expression system in COS-1 cells, we
observed that doxycycline (Dox) induced expression of the sFv in a dose-dependent
manner, and that the sFv was localized mainly in the nucleus. The Dox-induced
anti-c-Myb sFv also inhibited the transactivating activity of c-Myb in a dose
dependent manner. We subsequently confirmed the Dox-induced expression of the sFv
in the leukemia cell line K562. Proliferation of the target leukemia cells was
also inhibited. These results suggest that the anti-c-Myb sFv may represent a
viable method for gene therapy of c-myb-dependent hematopoietic malignancies.
PMID- 10678369
TI - The aortic valve blood supply.
AB - BACKGROUND AND AIM OF THE STUDY: Normal valves are known to be metabolically
active, yet the route of oxygen delivery is unclear. Although diffusion from the
valve surface is the presumed source, the presence, distribution and importance
of the aortic valve's vascular bed is unclear. METHODS: Seventeen porcine hearts
(51 cusps) were obtained at slaughter. The coronary circulation was pressure
rinsed with a heparin solution and filled with an Aquablack solution at
physiological pressure. The cusps were subsequently dissected and fixed for
viewing with an inverted microscope. The anterior leaflet of the mitral valve was
evaluated as a control for the vessel filling protocol. Using Adobe Photoshop and
captured images, whole cusps were reconstructed, a grid was overlaid and vascular
distribution evaluated. RESULTS: Of the 15 porcine aortic valves that filled,
32/45 (71%) of the cusps contained vessels. Nine valves had vasculature in all
three cusps and two valves were completely avascular. Vessels were found
predominantly in the basal third of the cusps and extended in from the
commissures almost to the level of the free edge. There was a statistically
significant difference (p<0.001) between the appearance of vessels in the basal
region and in the mid and free edge regions of the valve. No difference in
vascularization pattern was noted between the left, right or non-coronary cusps.
CONCLUSIONS: The presence of a vasculature suggests that the metabolic activity
of the cusp is greater than can be supported by diffusion from the cusp surface
alone. The absence of functioning vessels might explain the failure associated
with cryopreserved implants and may play a role in the durability problems faced
by bioprosthetic valves. It will also be important to consider the role of this
intrinsic circulation with the advent of tissue-engineered valves.
PMID- 10678370
TI - Significant increase of aortic root volume and commissural area occurs prior to
aortic valve opening.
AB - BACKGROUND AND AIM OF THE STUDY: The increased use of autologous, homologous or
heterologous aortic root demands a detailed knowledge of its anatomy and
function. The advent of 3-D digital sonomicrometry offered the opportunity to
acquire precise information on the root and leaflet movements during the cardiac
cycle. METHODS: Under cardiopulmonary bypass, sonomicrometry crystals were
implanted in the aortic root and valve of eight sheep. Crystals were sutured at
each commissure (n = 3), the top of the sinotubular junction (n = 3), lowest
point of the annulus (n = 3), and leaflet tip (n = 3). 3-D coordinates of each
crystal were recorded, together with left ventricular and aortic root pressures
and ECG. When the animal had returned to a stable hemodynamic condition, the
maximum and minimum distances between two crystals, and areas between three
crystals, were calculated. Changes in root volume and leaflet position were time
related to the pressure changes. RESULTS: The most significant change between
maximum and minimum distance between crystals during the cardiac cycle occurred
at the commissural level. Similarly, the triangle defined by the three
commissural crystals showed the greatest change in area (47%). The root volume
increased by an average of 22%; about 40% of this increase occurred during the
isovolumic phase. The aortic leaflets began to open before ejection. CONCLUSION:
We postulate that aortic valve opening is initiated by the outward pull of the
commissures. These findings should impact on aortic root surgery.
PMID- 10678371
TI - Aortic root dilation prior to valve opening explained by passive hemodynamics.
AB - BACKGROUND AND AIM OF STUDY: During the June 1999 World Symposium on Heart Valve
Disease, the mechanism by which the aortic valve opens was discussed. It was
suggested, indirectly, that the recently discovered contractile elements within
the aortic valve may be responsible. We propose that aortic root dilation does
not require any active mechanism within the leaflets or aortic wall, and provide
an explanation based entirely on the passive hemodynamics of the aortic valve and
root. METHODS AND RESULTS: Previous studies using cine fluoroscopy and
sonomicrometry have reported a 5-7% expansion of the aortic root during
ventricular contraction, prior to aortic valve opening. Simplified force
calculations indicate that the mechanical interactions between the aortic valve
and root produce an inward pull on the commissures, constraining the aorta from
fully dilating. During systole, as the pressure in the ventricle increases and
the aortic valve becomes unloaded, the inward pull on the commissures is reduced
and the aorta is able to dilate fully. Aortic dilation therefore occurs before
the aortic valve opens. CONCLUSION: We conclude that this mechanism of aortic
root dilation prior to valve opening is purely passive, and does not require any
active process by the aortic valve or the aortic root.
PMID- 10678372
TI - Decalcification of the aortic valve does not prevent early recalcification.
AB - BACKGROUND AND AIM OF THE STUDY: The excellent results with atrioventricular
valve reconstruction have stimulated surgeons to attempt reconstruction of
calcified aortic valves using decalcifying techniques, but long-term results have
been disappointing. The aim of this in vitro study was to evaluate the surface
structure of decalcified aortic valve tissue and its potential for
recalcification. METHODS: Aortic leaflets were removed from 26 patients with
aortic stenosis during elective valve replacement and decalcified by meticulous
dissection. Representative specimens were prepared for scanning electron
microscopy (SEM) and calcium content in the heavily calcified part of the leaflet
in both macroscopically non-calcified and decalcified tissue was determined by
atomic absorption spectroscopy (AAS). Additional probes of 'non-calcified' and
decalcified tissue were incubated for two and four weeks with medium containing a
physiological concentration of calcium to determine their potential for
recalcification. As a control, 13 specimens from non-calcified valves were
incubated according to the same protocol. RESULTS: All calcified specimens
contained high calcium levels (142.70+/-53.76 mg/g). Surgical dissection reduced
tissue calcium content significantly (10.04+/-13.43 mg/g). Following two weeks'
incubation with calcium, these specimens retained significantly higher levels of
calcium (2.88+/-5.17 mg/g) than the 'non-calcified' specimens (19.17+/-7.61
versus 13.49+/-6.27 mg/g; p<0.05); after four weeks similar calcium levels were
reached (32.00+/-10.27 versus 28.35+/-9.84 mg/g; p = NS). Non-calcified tissue
showed the lowest calcium uptake (4.75+/-4.55 mg/g and 12.29+/-9.43 mg/g at two
and four weeks; p<0.05). SEM revealed a loss of endothelial coverage in the
calcified areas; decalcification led to an irregular fibrillar surface. Only
parts of the macroscopically normal tissue contained endothelial cells, whereas
the control tissue showed intact cellular coverage. CONCLUSION: Aortic valve
decalcification can effectively remove calcifications, but leaves a fibrillar
structure that tends rapidly to accumulate calcium. Even normal-appearing tissue
from diseased valves has a higher potential for calcification than normal
valvular tissue. These data support the observation of only limited clinical
benefits being derived after aortic valve decalcification for aortic stenosis.
PMID- 10678373
TI - Mechanics of cryopreserved aortic and pulmonary homografts.
AB - BACKGROUND AND AIM OF THE STUDY: The surgical placement of pulmonary valve grafts
into the aortic position (the Ross procedure) has been performed for three
decades. Cryopreserved pulmonary valves have had mixed clinical results, however.
The objectives of this study were to compare the mechanics of cryopreserved human
aortic and pulmonary valve cusps and roots to determine if the pulmonary root can
withstand the greater pressures of the aortic position. METHODS: Six aortic and
six pulmonary valve roots were obtained from the Oxford Valve Bank. They were
harvested during cardiac transplantation from hearts explanted for dilated
cardiomyopathy (mean patient age 68 years). The whole roots were initially stored
frozen at -186 degrees C, then shipped packed on dry ice. After complete thawing,
the roots were pressurized whole; test strips were then cut from the valve cusps,
roots and sinuses and tested for stress/strain, stress relaxation, and ultimate
failure strength. RESULTS: The pulmonary roots were more distensible (30% versus
20% strain to lock-up) and less compliant when loaded to aortic pressures. The
pulmonary valve cusp and root tissue also showed greater extensibility and
greater stiffness (lower compliance) when subjected to the same loads.
CONCLUSION: We conclude that mechanical differences between aortic and pulmonary
valve tissues are minimal. The pulmonary root should withstand the forces imposed
on it when placed in the aortic position. However, if implanted whole, the
pulmonary root will distend about 30% more than the aortic root when subjected to
aortic pressures. These geometric changes may affect valve function in the long
term and should be appreciated when implanting a pulmonary valve graft.
PMID- 10678374
TI - Results of the Ross operation in rheumatic versus non-rheumatic aortic valve
disease.
AB - BACKGROUND AND AIM OF THE STUDY: A total of 213 patients underwent the Ross
operation at our institution between January 1990 and January 1999. Outcome was
assessed in rheumatic (RH) patients and compared with that in patients with other
etiology (non-RH). METHODS: After exclusion of 69 patients with a follow up of
<18 months, the study group comprised 144 patients (119 RH, 25 non-RH). Patients
were studied clinically and by echo-Doppler cardiography preoperatively, within 2
months and 6-8 months after surgery, and yearly afterwards. Preoperative
assessment included age, gender, body surface area (BSA), type of aortic valve
lesion and additional valve disease, left and right ventricular outflow tract
(LVOT, RVOT) dimensions, and left ventricular (LV) size, function and mass.
Postoperatively, patients were studied for presence and severity of autograft
regurgitation, mitral regurgitation, LV size, function and mass, and incidence
and timing of reoperation. RESULTS: On average, RH patients were older and had
higher BSA, more aortic regurgitation than stenosis, more additional mitral valve
disease (mostly regurgitation), larger LV size and poorer LV function. Mitral
valve repair was performed in 24% of RH patients versus 0% of non-RH patients.
Postoperatively, differences in LV size, function and mass remained present, but
diminished during follow up. The autograft reoperation incidence was 22% (26/119)
in RH patients versus 8% (2/25) in non-RH patients (p = NS). Preoperative
predictors for reoperation in the RH group were severe concomitant mitral
regurgitation (MR), followed by male gender and large indexed LVOT (all p<0.001
by discriminant analysis). CONCLUSION: Marked differences were present in patient
characteristics between rheumatic and nonrheumatic patients who underwent the
Ross operation. Rheumatic patients had a higher incidence of autograft
reoperation. Severe concomitant MR was the most important predictor for
reoperation in rheumatic patients.
PMID- 10678375
TI - Comparative analysis of left ventricular hemodynamics and hypertrophy after
aortic valve replacement with homografts or mechanical valves.
AB - BACKGROUND AND AIM OF THE STUDY: The study aim was to examine comparatively the
effects of prosthetic and homograft valves in the aortic position on ventricular
hemodynamics and structure. METHODS: Hemodynamic evaluations were performed at
rest and during exercise in 38 patients who had undergone aortic valve
replacement (AVR) with either a homograft (n = 19) or prosthetic valve (19-23 mm;
n = 19). Using echocardiographic, electrocardiographic and hematologic methods,
the pressure gradient (PG); aortic valve area; diameters of left anterior wall,
posterior wall (PW) and interventricular septum (IVS); ejection fraction (EF);
left ventricular mass (LVM) and mass index (LVMI); electrocardiographic data of
LV hypertrophy; hemoglobin; hematocrit and lactate dehydrogenase (LDH) levels
were measured. RESULTS: LVM and LVMI decreased significantly after surgery in
both groups (p<0.001), but the decrease was significantly greater in the
homograft group (p<0.05). The IVS and PW diameters in the homograft group
decreased significantly postoperatively (p<0.05); the inter-group difference was
also significant (p<0.01). In the homograft group there was a significant
improvement in EF (p<0.05), and the exercise PG was significantly less. Both
groups showed improved LV hypertrophy and correlation between V1S >24 mm criteria
and LVMI measurements. Postoperative LDH levels in the homograft group were
significantly lower than preoperative levels (p<0.05); the intergroup difference
was also significant (p<0.001). CONCLUSIONS: Our data suggest that homografts, as
compared to mechanical prostheses, provide significantly better hemodynamics in
the aortic position.
PMID- 10678376
TI - Wound healing in the mitral valve.
AB - BACKGROUND AND AIMS OF THE STUDY: Limited information is available on the healing
of wounds in the mitral valve. In the present study, this process has been
evaluated in young sheep. METHODS: Histologic, histochemical and transmission
electron microscopic studies were made of the healing of wounds produced
surgically under cardiopulmonary bypass, in the mitral valve (a 1 cm-long
radially oriented incision at the free edge of the anterior leaflet) of young
sheep (n = 11). RESULTS: All animals developed severe mitral regurgitation, as
demonstrated by hemodynamic, ultrasound and ventriculographic studies. At four to
five weeks, the edges of the incision were only partially covered by endothelium
and had small deposits of fibrin. Two types of granulation tissue were associated
with wound healing. The first covered the cut edge and consisted of myxoid tissue
that extended from the valvular spongiosa and fibrosa; the second type consisted
of spindle-shaped cells arranged parallel to the surface and surrounded by a
slightly myxoid stroma. This granulation tissue resembled that caused by reactive
fibrosis in regurgitant mitral valves. The connective tissue cells in granulation
tissue developed increasing amounts of actin-like filaments as a function of time
after operation. This differentiation resulted in the development of
myofibroblasts. In contrast to the avascular nature of normal mitral leaflets,
capillaries and arterioles first appeared in the middle portion of the leaflet at
eight weeks, and at the proximal edges of the wounds at 12 weeks. CONCLUSION: The
healing of mitral valvular wounds is a slow process that requires between eight
and 12 weeks for the formation of a dense collagenous scar at the edges and
complete restoration of the endothelial lining. Progression of healing is
associated with the phenotypic modulation of connective tissue cells from
fibroblasts to myofibroblasts and neovascularization of the leaflets.
PMID- 10678377
TI - Ischemic mitral valve repair surgery.
AB - BACKGROUND AND AIM OF THE STUDY: The management of concomitant moderate or severe
ischemic mitral regurgitation in the presence of ischemic heart disease is
important for long-term prognosis. Mitral repair by either a suture or ring
annuloplasty method has been advocated, although clear superiority of either
method has not been established. METHODS: Combined coronary artery bypass and
mitral valve surgery for ischemic mitral incompetence was performed on 68
consecutive patients between January 1996 and December 1998. The outcome in 63 of
these patients (35 females, 28 males) who underwent mitral valve repair was
reviewed. RESULTS: Average patient age was 61+/-9.4 years (range: 39-81 years).
Average left ventricular ejection fraction (LVEF) was 42.1%; a suture
annuloplasty was used in 84% and a ring in 16%. The average number of distal
anastomoses was 3.9+/-1.1 (range: 1-6) and aortic cross-clamp time was 131+/-35
min (range: 58-238 min). Operative mortality rate (<30 days or in-hospital) was
12.7% and only requirement for intra-aortic balloon pumping either before or
during surgery (21%) was predictive (p<0.05). On discharge, 98.2% of patients
were in NYHA class I or II. Follow up (range: 1-35 months) was complete in 95% of
cases. Moderate mitral regurgitation on discharge occurred in nine patients and
was not related to the type of annuloplasty. Predictive risk factors were
preoperative severe mitral regurgitation (p<0.04), poor LVEF (p = 0.05), and was
predictive of deterioration of NYHA class (p<0.02), progression of regurgitation
(p<0.05), and poor outcome (p<0.01). Poor outcome was also related to surgeon's
experience. Structural valvular deterioration occurred in 21.8% of operative
survivors, and there was one reoperation and four late deaths. The survival rate
(including operative deaths) at 35 months was 68.3 +/- 13.1%, and event-free
survival rate (no mortality, reoperation or angina) 65.2+/-6.2%. CONCLUSIONS: The
type of annuloplasty used did not influence outcome. The risk of structural
mitral valve dysfunction on follow up was related to severe preoperative mitral
regurgitation, poor LVEF, surgeon's experience, and was predictive of poor
outcome.
PMID- 10678378
TI - Surgical repair of the prolapsing anterior leaflet in degenerative mitral valve
disease.
AB - BACKGROUND AND AIM OF THE STUDY: Repair of the prolapsing anterior leaflet (AML)
in degenerative mitral valve disease is more demanding than that of the posterior
leaflet. We reviewed our experience in the past eight years, to examine the
safety, efficacy and stability of various repair artifices. METHODS: Between
January 1989 and December 1997, 102 patients (mean age 64 years; range: 26-86
years) with mitral regurgitation (MR) due to prolapse of the anterior or both
mitral leaflets underwent mitral valve repair. Sixty-six patients were in NYHA
class > or =III, and 94 had MR grade >II. Acute endocarditis was present in 12
patients and Barlow disease in 16. Surgical techniques consisted of chordal
shortening (n = 36), chordal transposition (n = 16), papillary muscle shortening
or plication (n = 10), flip-over (n = 20) and artificial chordae implantation (n
= 20). RESULTS: There was no early mortality; one patient required early mitral
valve replacement (MVR) for late-appearing systolic anterior motion, and one
patient benefited from a successful re-repair on day 8 for partial posterior
leaflet desinsertion. Mean follow up was 30 months (range: 3-92 months); there
were four late deaths (two valve-related cerebrovascular accidents); two patients
required re-repair (one after three months for prosthetic ring thrombosis, and
one after 10 months for rupture of shortened chordae (corrected by flip-over)).
Five patients had MVR between four and 32 months later: one for mitral stenosis
due to posterior leaflet calcification, and four for recurrent MR due to the
rupture of shortened chordae (n = 3) or plicated papillary muscle (n = 1). One
patient suffered bacterial endocarditis which was treated medically. Of the 92
remaining patients with valve repair, 81 are currently asymptomatic, five are in
NYHA class II and four in class III. Transesophageal echocardiographic restudy (n
= 76) at a mean of 30 months after surgery revealed no MR in 68 patients, and MR
of grade or =70 years and with small aortic root diameters (< or =23 mm).
PMID- 10678384
TI - First clinical experience with a mechanical valve with silver coating.
AB - BACKGROUND AND AIM OF THE STUDY: The interface between the annulus and sewing
cuff is the infectious center of prosthetic valve endocarditis (PVE). To decrease
the incidence of PVE, the sewing cuff of the St. Jude Medical (SJM) mechanical
heart valve was permanently coated with elemental silver (Silzone coating). In
vitro data have supported the antimicrobial efficacy of this coating. METHODS: To
study any adverse effects of the silver coating in humans, serum silver levels
were determined (by graphite furnace atomic absorption spectrometry) before
(baseline) and at five intervals after operation: day 1, day 3, discharge, one
month, and two months. Between January and August 1997, 38 patients (71% males)
underwent surgical implant of a SJM Masters Series valve with Silzone coating for
the aortic valve (n = 29), mitral valve (n = 6), or both valves (n = 3). Five
patients (13%) underwent concomitant procedures. Two patients (5%) presented with
native active valve endocarditis. RESULTS: There was no hospital mortality or
valve-related hospital morbidity. Blood silver concentrations peaked shortly
after surgery and then decreased during the postoperative period. Average levels
were consistently below 4 parts per billion (ppb). Levels below 10 ppb are
considered normal. Follow up was 95% complete. There were no recurrent or new
cases of endocarditis. CONCLUSION: These clinical data indicate that the SJM
Masters Series valve with Silzone coating performs well. No adverse effects of
the silver coating could be detected, and there were no valve-related
complications.
PMID- 10678385
TI - Preliminary experience with Silzone-coated St. Jude medical valves in acute
infective endocarditis.
AB - BACKGROUND AND AIM OF THE STUDY: The rate of recurrent postoperative endocarditis
after valve replacement in early-stage acute infective endocarditis is extremely
high. Metallic silver coating of the sewing ring may improve the short- and long
term outcome after valve implantation. This report details our experience with
the St. Jude Medical Silzone prosthesis in early surgical treatment of acute
infective endocarditis. METHODS: Ten patients (mean age 66.4 years) referred for
native valve or prosthetic valve endocarditis were operated on between April 1998
and June 1999. The microorganisms responsible for the acute infection were
Staphylococcus (n = 1), Streptococcus (n = 1) and Pseudomonas aeruginosa (n = 1);
blood cultures remained negative in two cases. The indication for surgical
treatment was related to hemodynamic condition (n = 5), a major cerebral event
(stroke; n = 1), annulus abscess (n = 1), and echocardiographic evidence of large
cuspal vegetations (n = 3). All patients had received preoperative intravenous
antibiotics (mean 7.8 days). Four mitral, five aortic valve replacements, and one
double mitral-aortic valve replacement, were performed after extensive
debridement of the infected and necrotic tissues. Mean duration of postoperative
antibiotic treatment was 32.3 days. Postoperative follow up (mean 6 months;
range: 2-14.2 months) was 100% complete, and included prospective repeated
transthoracic echocardiography at one week, and one, six and 12 months
postoperatively. RESULTS: One patient died early in the immediate postoperative
period from pneumonia and major hypoxemia. All other patients are symptom-free,
without evidence of recurrent infection and perivalvular leak. CONCLUSION:
Although these early results with the St. Jude Medical Silzone prosthesis require
confirmation by more extensive studies, they infer that silver coating of the
sewing ring may dramatically improve management of patients with active
endocarditis.
PMID- 10678386
TI - In vivo efficacy of silver-coated fabric against Staphylococcus epidermidis.
AB - BACKGROUND AND AIM OF THE STUDY: Prosthetic valve endocarditis (PVE) is a serious
complication of heart valve replacement. The use of silver-coated polyester
fabric in sewing cuff fabrication is intended to reduce the incidence of PVE. In
this study, three pathogenic strains of Staphylococcus epidermidis (two PVE and
one peripheral vasculature pathogen) were used to evaluate infection of silver
coated and uncoated fabric. METHODS: Fabric was inoculated by preincubation for
30 min in bacterial suspensions containing 10(4), 10(5), 10(6), 10(7) or 10(8)
CFU/ml, and implanted subdermally in mice for up to seven days. Bacteria adherent
to fabric implanted for zero, one, three, or seven days were enumerated by
sonicating the fabric and plating serial dilutions of the resulting suspension.
Percent infection was assessed by implanting samples, subdermally, for seven
days, then incubating explanted samples in growth media for three days and
calculating the percent of fabric showing bacterial growth, for each
concentration of inoculum. A logistic regression model was used to estimate
curves relating percent infection to log concentration of the bacterial inoculum.
These curves were used to estimate the concentration of inoculum required to
produce 50% infection (ID50) for the three strains of S. epidermidis, for silver
coated and uncoated fabric. RESULTS: Direct enumeration showed no difference in
bacteria adherent to silver-coated and uncoated fabric, and no bacteria present
in either fabric type in samples implanted for seven days. Nevertheless,
incubation of those samples in growth media showed that many of the samples were
infected. The calculated ID50 was significantly lower for silver-coated fabric
than for uncoated fabric, for all three strains of S. epidermidis tested.
CONCLUSION: Silver-coated fabric increases resistance to infection by S.
epidermidis in this direct-contamination, mouse subdermal model.
PMID- 10678387
TI - Examination of hemolytic potential with the On-X(R) prosthetic heart valve.
AB - BACKGROUND AND AIM OF THE STUDY: Mechanical valves are known to produce chronic,
subclinical hemolysis in most patients. Generally, haptoglobin is reduced to
below normal in most patients, while lactate dehydrogenase (LDH) is increased to
as much as 200% above the upper normal, sometimes resulting in anemia. The study
was designed to investigate the clinical hemolysis of the On-X(R) prosthetic
heart valve in a multicenter experience with a standard protocol and a single
clinical laboratory. METHODS: Between September 1996 and August 1998, 248
patients underwent isolated valve replacement at 10 European centers. Blood
samples were collected from these preoperatively and at 3-6 months and one year
postoperatively. All samples were analyzed at a central laboratory, thus assuring
poolability of the data. In total, 151 patients were tested at 3-6 months, and 62
at one year. Blood parameters measured were LDH, haptoglobin, hematocrit, total
hemoglobin, red cell count and reticulocyte count. Paired analysis was used to
compare preoperative baseline values with 3-6-month and one-year values. Data
were analyzed with regard to both valve position and size. RESULTS: At 3-6 months
and one year after surgery, average values for hematocrit, hemoglobin, red cell
count and reticulocyte count were all near the center of the normal range,
regardless of valve position or size. Statistically significant increases in red
cell count and decreases in reticulocyte count occurred after both aortic valve
replacement (AVR) and mitral valve replacement (MVR). These changes were of no
clinical importance, but indicate that anemia has not occurred in these patients.
At 3-6 months, haptoglobin was reduced to below normal in 86% of both AVR and MVR
patients; this also occurred after one year and was statistically significant.
Postoperatively, the mean LDH value in AVR was 228 U/l (91% of upper normal, 250
U/l) at 3-6 months, and 246 U/l (98% of upper normal) at one year. In MVR, these
LDH values were 271 U/l (108% of upper normal) and 265 U/l (106% of upper
normal). CONCLUSIONS: These results indicate that the On-X valve causes lower
levels of chronic hemolysis in the immediate postoperative period and up to one
year after surgery, especially when compared with reports of LDH elevations up to
200% of upper normal. Hemolytic anemia has not occurred in this patient
population.
PMID- 10678388
TI - Repeated thrombolysis in multiple episodes of obstructive thrombosis in
prosthetic heart valves: a report of three cases and review of the literature.
AB - BACKGROUND AND AIM OF THE STUDY: Thrombolysis is an emerging method to open
thrombosed prosthetic heart valves. However, its applicability and safety in
multiple recurrent thrombotic episodes is unclear. METHODS: Among 16 patients
with thrombosed prosthetic valves treated with thrombolysis during a 33-month
period, three patients (one mitral and two tricuspid) experienced four episodes
each, and these were treated with repeated thrombolytic therapy. Data on patient
demographics, clinical presentation, diagnosis, treatment and outcome are
presented. RESULTS: Thrombolysis was successful in 10/12 episodes (83%); there
was delayed response in one episode (8%), and partial response in one episode
(8%). There were no major complications. However, a fifth thrombotic episode
occurred in two patients with tricuspid prostheses, mandating re-do surgery.
CONCLUSION: Thrombolysis in re-thrombosed prosthetic heart valves is feasible,
highly successful and safe, and may therefore be used judiciously in selected
patients who could not, or would not, undergo redo surgery. A high recurrence
rate in the tricuspid position may implicate earlier surgical intervention, which
should be individualized.
PMID- 10678389
TI - Phenotypic and functional characterization of interstitial cells from human heart
valves, pericardium and skin.
AB - BACKGROUND AND AIM OF THE STUDY: Human heart valve interstitial cells (ICs) have
been understudied to date. The aim of this study was to determine whether valve
ICs were uniquely different from pericardial ICs and skin fibroblasts by
determining their phenotype and investigating their reactivity. METHODS: ICs were
cultured from human heart valves (n = 13), pericardium (n = 4) and skin (n = 4).
Cell phenotype was determined by immunofluorescence using a panel of antibodies
against surface and cytoskeletal components, and intracellular calcium changes
were evaluated by loading the cells with fura-2 acetoxymethyl ester. RESULTS:
Skin fibroblasts expressed virtually no smooth muscle (SM) alpha-actin, whereas,
56.9+/-8.9% (mean +/- SEM) of ICs from valves and 21+/-7.6% of ICs from
pericardium expressed SM alpha-actin. ICs from pericardium and skin fibroblasts
always expressed a fibroblast surface antigen, whereas expression was variable on
valve ICs (80+/-6.9%). All cells expressed prolyl 4-hydroxylase, beta-tubulin and
vimentin, but not desmin. Transient increases in intracellular calcium were
induced by vasoactive agents: skin fibroblasts were least responsive to all
agents. CONCLUSIONS: ICs cultured from heart valves consist of a mixed population
of specific cell types, many of which express SM alpha-actin and may be
classified as myofibroblasts. The intracellular calcium responses to vasoactive
agents indicated that a number of receptor signaling pathways existed. Evaluation
of these may help to elucidate the role of myofibroblasts and other fibroblast
phenotypes in valve function/dysfunction, as well as contribute to the
development of tissue-engineered valves.
PMID- 10678390
TI - The dilemma of accelerated bioprosthetic and polymeric valve testing.
PMID- 10678391
TI - Fatigue analysis of clinical bioprosthetic heart valves manufactured using
photooxidized bovine pericardium.
AB - BACKGROUND AND AIM OF THE STUDY: Recent reports have given details of early
clinical failures of bioprosthetic heart valves manufactured using dye-mediated
photooxidized bovine pericardium. These failures were attributed to abrasion of
the inflow surface of the leaflets against the cloth-covered inner face of the
outer valve frame. These failures had not been detected during preclinical
testing of such valves. The aim of this study was to determine if such failure
modes could be replicated during fatigue testing of the photooxidized valves, and
whether lining of the inflow face of the outer frame with pericardium could
eliminate these failures. METHODS: The fatigue properties of six lined and six
unlined PhotoFix(R) alpha valves was determined using two Rowan Ash fatigue
testers which were cycled at 15 Hz for a maximum of 210 million cycles. The
closing pressure within in each chamber was 110+/-10 mm Hg. Each valve was
inspected every 40 million cycles for any signs of fatigue failure. All valves
were tested to at least 210 million cycles. RESULTS: In all six lined PhotoFix
alpha valves there was no evidence that wear, tear or abrasion of the inflow
aspect of the leaflets adjacent to the inflow face of the outer frame had
occurred. Only one unlined valve showed any signs of damage adjacent to the outer
frame, as evidenced by loss of loose connective tissue, but this did not have the
imprint of the cloth covering, which would have suggested actual wear.
Effectively, after 200 million cycles, no fatigue failures of either the lined or
the unlined PhotoFix alpha valves had occurred. Moreover, the leaflet tears that
had been observed clinically were not replicated in this study. CONCLUSION:
Previous studies have shown a good qualitative, quantitative association between
fatigue failure in Rowan Ash accelerated fatigue testers, and clinical experience
in glutaraldehyde-treated bovine pericardial valves. The accelerated fatigue
tester did not provide an adequate model for the prediction of clinical failure
for the photooxidized pericardial valves.
PMID- 10678392
TI - Future directions in tissue heart valves: impact of recent insights from biology
and pathology.
PMID- 10678393
TI - Mitral valve replacement with a pulmonary autograft: initial experience.
PMID- 10678394
TI - Sheep CD1 genes and proteins.
AB - Interest in CD1 genes and proteins was initially stimulated by their close
evolutionary and structural relationship to MHC class I molecules. The
demonstration that CD1b and c molecules present novel non-peptide antigens to T
cells and play a role in protection against mycobacterial infection then focused
attention on the functional role of CD1 proteins. Sheep possess at least seven
CD1 genes, including CD1B, D and E, which is the most complex genetic arrangement
identified so far in any animal. OvCD1B consists of at least three distinct
genes, with the probability of limited polymorphism and the existence of splice
variants. Most anti-sheep CD1-specific monoclonal antibodies react with OvCDlb
and phenotypic and immunochemical data suggests the existence of two variants.
CD1D genes have been identified in all species studied, suggesting a conserved
role for CDld proteins across mammalian species. Presumptive evidence for the
existence of OvCDIE has been obtained by NH2-terminal sequencing of protein
precipitated by the mAb 20.27 (SBU-T6). Confirmatory evidence from gene cloning
experiments is currently being sought. Collectively, these factors make the sheep
CD1 family a highly relevant model for investigating the in vivo role of CD1
molecules. In this survey, the properties of monoclonal antibodies specific for
sheep CD1, the cellular distribution and physicochemical characteristics of sheep
CD1 molecules and the current state of knowledge on sheep CD1 genetics are
reviewed.
PMID- 10678395
TI - Lymphocyte populations and adhesion molecule expression in bovine tonsils.
AB - Bovine tonsils are mucosal-associated lymphoid tissue (MALT) located at the entry
of the pharynx where both inhaled and ingested antigens can induce an immune
response. This study was conducted to determine the lymphocyte populations and
adhesion molecule expression in the palatine tonsil (PT) and pharyngeal tonsil
(PhT) of adult cattle and compare them with typical MALT (discrete Peyer's
patches, PP) and a peripheral lymph node (parotid lymph node, PLN). The
distribution of various lymphocyte subsets was determined in situ by
immunofluorescence, and their proportions were determined by multicolor flow
cytometry. The tonsils were similar to PP in the proportions of B- and T-cells
(25-32% T-cells, 39-45% B-cells), and T cell subpopulations (CD4, CD8, and
gammadelta). The PP contained the highest proportion of memory T-helper cells
with beta7 integrin (30.3%+/-5.4), the tonsils intermediate (PT: 19.8%+/-4.4 and
PhT: 19.7%+/-4.9), and the PLN had the lowest proportion (15.4%+/-3.1). The
opposite relationship was observed with CD62L on naive T- helper cells as PP had
the lowest proportion (14.2%+/-6.4), the tonsils intermediate (PT: 17.4%+/-2.5
and PhT: 24.3%+/-7.3), and the PLN the highest proportion (45.3%+/-6.5). MAdCAM-1
was highly expressed in the high endothelial venules (HEV) of PP, with variable
and weak expression in the tonsils and PLN. PNAd, on the other hand, was highly
expressed in HEV of tonsils and PLN, and weakly expressed in the PP. These
results indicate that the bovine tonsils share characteristics with both PP and
PLN. The alpha4beta7/MadCAM-land CD62L/PNAd interaction may be involved in
lymphocyte migration to the tonsils, but it is likely that other adhesion
molecules participate as well. Similarities between the human and bovine tonsils
suggest that cattle may provide a good model to study the role of the tonsil in
the respiratory immune response.
PMID- 10678396
TI - Molecular cloning, phylogenetic analysis and expression of beluga whale
(Delphinapterus leucas) interleukin 6.
AB - Interleukin 6 (IL-6) is a cytokine produced primarily by the
monocytes/macrophages with regulatory effects in hematopoiesis, acute phase
response, and multiple aspects of the immune response. IL-6 exerts its activity
through its binding to specific high affinity receptors at the surface of target
cells. As yet, no molecular data have been reported for the beluga whale IL-6. In
this study, we cloned and determined the entire beluga whale IL-6-encoding cDNA
sequence by reverse transcription-polymerase chain reaction (RT-PCR) sequencing,
and analysed its genetic relationship with those from several mammalian species
including human, rodent, ruminant, carnivore and other marine species. The
identity levels of beluga whale IL-6 nucleic and deduced amino acid sequences
with those from these mammalian species ranged from 62.3 to 97.3%, and 42.9 to
95.6%, respectively. Phylogenetic analysis based on amino acid sequences showed
that the beluga whale IL-6 was most closely related to that of the killer whale.
Thereafter, beluga whale IL-6-encoding sequence was successfully expressed in
Escherichia coli by using the pTHIOHisA expression vector for the production of a
recombinant fusion protein. The immunogenicity of the recombinant fusion protein
was then confirmed as determined by the production of a beluga whale IL-6
specific rabbit antiserum.
PMID- 10678397
TI - Equine bullous pemphigoid IgG autoantibodies target linear epitopes in the NC16A
ectodomain of collagen XVII (BP180, BPAG2).
AB - Bullous pemphigoid (BP) is an autoimmune subepithelial blistering dermatosis of
humans, dogs, cats and pigs. It is characterized by skin-fixed and circulating
IgG autoantibodies that target one or both BP antigens. An immunological
homologue of BP in humans was diagnosed in two horses with cutaneous and mucosal
ulcerations as well as microscopic subepithelial vesiculation. Immunological
investigations revealed similar findings for both the horses. Direct
immunofluorescence demonstrated the presence of IgG deposited linearly at the
dermoepidermal junction in mucosal and skin biopsy specimens. Indirect
immunofluorescence testing confirmed the existence of circulating basement
membrane-specific IgG autoantibodies. Using intact and salt-split epithelial
substrates, serum IgG were shown to target antigens situated not only at the
basal, but also at the lateral and apical aspects of stratum basale
keratinocytes. Immunoblotting and ELISA corroborated that the IgG from affected
horses, but not those from normal controls, exhibited high immunoreactivity
against the NC16A extracellular domain of type XVII collagen (BPAG2, BP180).
Equine BP could be proposed, therefore, as another spontaneous model of this most
common basement membrane autoimmune dermatosis of humans.
PMID- 10678398
TI - Identification of two allelic IgG1 C(H) coding regions (Cgamma1) of cat.
AB - Two types of cDNA encoding IgG1 heavy chain (gamma1) were isolated from a single
domestic short-hair cat. Sequence analysis indicated a higher level of similarity
of these Cgamma1 sequences to human Cgamma1 sequence (76.9 and 77.0%) than to
mouse sequence (70.0 and 69.7%) at the nucleotide level. Predicted primary
structures of both the feline Cgamma1 genes, designated as Cgamma1a and Cgamma1b,
were similar to that of human Cgamma1 gene, for instance, as to the size of
constant domains, the presence of six conserved cysteine residues involved in
formation of the domain structure, and the location of a conserved N-linked
glycosylation site. Sequence comparison between the two alleles showed that 7 out
of 10 nucleotide differences were within the C(H)3 domain coding region, all
leading to nonsynonymous changes in amino acid residues. Partial sequence
analysis of genomic clones showed three nucleotide substitutions between the two
Cgamma1 alleles in the intron between the CH2 and C(H)3 domain coding regions. In
12 domestic short-hair cats used in this study, the frequency of Cgamma1a allele
(62.5%) was higher than that of the Cgamma1b allele (37.5%).
PMID- 10678399
TI - Production and characterisation of two monoclonal antibodies recognising equine
IgG Fc receptors.
AB - Despite the importance of IgG Fc receptors in the regulation of various
immunological mechanisms, these receptors have not been well characterised in the
domesticated animals including equines. This paper describes the production of
two monoclonal antibodies (CVS 59 and CVS 61) that recognise equine IgG Fc
receptors. Fusions were conducted using BALB/c mice hyperimmunised with equine
peripheral blood mononuclear cells. Hybridoma supernatants were screened on the
basis of their ability to inhibit the rosetting of equine antibody coated sheep
erythrocytes with equine peripheral blood mononuclear cells. The mAbs were then
characterised for cellular distribution of the antigen by flow cytometry. Using
immunoprecipitation, it was shown that both under reducing and non-reducing
conditions, CVS 59 and CVS 61 precipitated a 80 and 40 kD protein, respectively.
From the functional study coupled with cellular distribution and molecular weight
of the antigen recognised by these mAbs, it would appear that CVS 59 and CVS 61
recognise an epitope on equine equivalent of human and murine FcgammaRIII and
FcgammaRII, respectively.
PMID- 10678400
TI - Induction of aggregation in porcine lymphoid cells by antibodies to CD46.
AB - CD46 is a major transmembrane glycoprotein that belongs to the regulator of
complement activation (RCA) family. Recently, mAbs to human CD46 were shown to
suppress IL-12 production. Here, we describe that mAbs against different porcine
CD46 epitopes induced a marked adhesion of normal lymphocytes. Addition of low
amounts of antibody to freshly isolated lymphocytes or thymocytes resulted in the
clustering of the cells. Cross-linking of CD46 molecules seems essential since
Fab fragments failed to induce aggregation. This aggregation was dependent on
active cell metabolism and on the presence of divalent cations and required a
functional cytoskeleton. It was not inhibited by antibodies to CD18, CD29, CD2,
CD11a and CD11b. Staurosporine, an inhibitor of protein kinases, partially
blocked the aggregation. This finding is indicative of a role of protein kinases
in the transduction of the signal generated by CD46 engagement.
PMID- 10678401
TI - Phenotypical characterization of T and B cell areas in lymphoid tissues of dogs
with spontaneous distemper.
AB - CD3, CD4, CD5, and CD8 antigen expression of T cells and IgG expression of B
cells and canine distemper virus (CDV) antigen distribution were
immunohistochemically examined in lymphoid tissues (lymph node, spleen, thymus,
and tonsil) of control dogs and animals with spontaneous canine distemper. In
addition, CNS tissue of all animals was studied for neuropathological changes and
CDV antigen distribution. Based on the degree of depletion distemper dogs were
classified into two groups. Group I represented animals with moderate to marked
lymphoid depletion, while group II dogs displayed mild or no depletion. CDV
antigen was mainly found in lymphocytes and macrophages of group I dogs, whereas
CDV expression was most prominent in dendritic cells of group II animals. In
group I dogs, a marked loss of CD3, CD4, CD5, CD8, and IgG expression was
noticed, hereby loss of CD4+ cells was more prominent than depletion of CD8+
cells. In the lymphoid tissues of group II animals, a significant increase in the
number of T and B cells was observed compared to group I dogs. The number of
CD3+, CD4+, and CD8+ cells in group II dogs was similar to the findings in
controls, however, CD5 and IgG expression was mildly reduced in T and B cell
areas, respectively. Additionally, in groups I and II dogs, CD3+ and CD5- T cells
were detected in T cell areas. Whether this cell population represents a cell
type with autoimmune reactive potential remains to be determined. Surprisingly in
group II animals, viral antigen was found predominantly in dendritic cells
indicating a change in the cell tropism of CDV during chronic infection and a
possible mechanism of viral persistence. The two patterns of lymphoid depletions
correlated to two different types of canine distemper encephalitis (CDE). Group I
dogs displayed acute non-inflammatory CDE, whereas group II dogs suffered from
chronic inflammatory demyelinating CDE, indicating a pathogenic relationship
between lymphocytic depletion and inflammatory brain lesions in distemper.
PMID- 10678402
TI - The possible role of osteoclastogenic oral bacterial products in etiology of
Paget's disease.
PMID- 10678403
TI - Normative data for iliac bone histomorphometry in growing children.
AB - Many insights into normal and pathologic bone development can only be gained by
bone histomorphometry. However, the use of this technique in pediatrics has so
far been hampered by the lack of reference data. Therefore, we obtained
transfixing iliac bone samples from 58 individuals between 1.5 and 22.9 years of
age (25 male; tetracycline labeling performed in 48 subjects), who underwent
surgery for reasons independent of abnormalities in bone development and
metabolism. The results of histomorphometric analyses of cancellous parameters
and cortical width are presented as means and standard deviations, as well as
medians and ranges in five age groups. In addition, the original data are
available from the authors. There were significant age-dependent increases in
both cortical width and cancellous bone volume, the latter being due to an
increase in trabecular thickness. Osteoid thickness did not vary significantly
with age. Bone surface-based indicators of bone formation showed an age-dependent
decline, reflecting similar changes in activation frequency. Mineral apposition
rate decreased continuously with age. Parameters of bone resorption did not vary
significantly between age groups. Paired biopsies from adjacent sites, obtained
in eight subjects, were used to examine the reproducibility of histomorphometric
parameters in children. The lowest coefficients of variation (<10%) were found
for structural measures, as well as mineral apposition rate and wall thickness.
The highest variability was found for cellular parameters. The availability of
reference material will greatly facilitate the use of histomorphometry in
pediatrics.
PMID- 10678404
TI - No major effect of estrogen receptor gene polymorphisms on bone mineral density
or bone loss in postmenopausal Danish women.
AB - The polymorphisms of the estrogen receptor (ER) gene defined by the restriction
enodonucleases PvuII and XbaI have recently been reported to be associated with
bone mineral density (BMD) in postmenopausal women. To investigate the possible
relation of the PvuII and XbaI restriction fragment-length polymorphisms of the
ER gene with BMD in Danish postmenopausal women, two studies were undertaken: 1)
a cross-sectional study of 499 postmenopausal women, where the ER genotypes and
alleles were related to BMD of the hip, spine, and lower forearm; and 2) a
longitudinal study of 101 postmenopausal women followed up for 18 years. In the
latter study, late postmenopausal bone loss in the hip and spine was determined
over a period of 6 years in women (mean age of 63 to 69 years), and long-term
postmenopausal bone loss in the lower forearm was determined over a period of 18
years in women (mean age of 51 to 69 years). Genotyping was performed through the
restriction cleavage of polymerase chain reaction-amplified genomic DNA with the
two restriction enzymes, PvuII and XbaI. Restriction fragment-length
polymorphisms were represented as P or p (PvuII) and X or x (XbaI), with the
lower case letters signifying the presence of the restriction site. The
frequencies of the ER genotypes were similar to previously published genotype
frequencies in Caucasian and Asian populations. No significant effect of the ER
genotypes or alleles on BMD was found at any site, nor was there a relation
between ER genotypes and the rate of bone loss either in the hip and spine over 6
years, or in the lower forearm over 18 years. In conclusion, we could not
demonstrate any major effect of the ER gene polymorphisms on BMD or rate of bone
loss in healthy postmenopausal Danish women.
PMID- 10678405
TI - Cellular distribution of estrogen receptor beta in neonatal rat bone.
AB - Estrogens affect bone metabolism, and ovariectomy of rats results in marked bone
loss caused by stimulation of osteoclastic bone resorption. Estrogen receptors
(ER) have been demonstrated in osteoblasts and bone marrow stromal cells, but
their presence in osteoclasts is controversial. Until recently, only one type of
ER (now renamed ERalpha) had been identified. After the discovery of a novel ER
subtype (ERbeta), it became necessary to re-investigate the ER expression in
human and rodent bone. In the present study we examined the expression of ER mRNA
in neonatal rat bone. Expression of ER alpha and beta mRNA (RT-PCR) was evident
in femurs of 3-week-old male and female rats. In situ hybridization
histochemistry of femural bones with digoxigenin labelled riboprobes, as well as
radioactively labeled riboprobes, revealed that ERbeta mRNA was predominantly
expressed in osteoblasts covering the metaphyseal bone trabecular surface. The
presence of ERbeta mRNA in osteoblasts of rat bone suggests that ERbeta is
involved in the mechanism of action of estrogens in bone.
PMID- 10678406
TI - Cross-sectional assessment of age-related bone loss in men: the MINOS study.
AB - There are few data on osteoporosis in men, but cross-sectional studies have shown
that age-related bone loss in men is of lower magnitude than in women. To
elucidate some controversies related partially to methodological aspects, we
measured bone mineral density (BMD) by dual-energy X-ray absorptiometry (DEXA) at
various skeletal sites (spine, hip, and whole body using a Hologic QDR-1500
device; forearm using an Osteometer DTX 100 device) in a large cohort of 1040
men, aged 19-85 years. The final investigation was performed on 934 men, aged 19
85 years, after exclusion of 106 men with disease or treatment known to affect
bone metabolism. Peak BMD was achieved at 25 and 29 years at the lumbar spine and
hip, respectively, but only at 40 and 37 years at the distal forearm and whole
body, respectively. The magnitude of bone loss between peak bone mass and 80
years of age was linear at most sites and averaged 13%-18%; that is, SD of 1.1
1.8 from peak BMD, except for Ward's triangle, which showed a marked bone loss of
43% (i.e., 2.5 SD), and for the lumbar spine. In the entire cohort, increase of
the average lumbar spine BMD after the age of 55 years was related to the
development of osteoarthritis, because, in men without severe arthritis, lumbar
spine BMD continued to decrease. Height-adjusted partial correlations indicate
that both the mineral content and the area of long bones of the limbs increased
with age up to 50 years, followed by a significant decrease of BMD without change
of bone surface. SD of mean BMD increased significantly with age at most skeletal
sites. In summary, age-related change of BMD varied according to skeletal site in
men with peak bone mass achieved earlier at sites rich in trabecular bone than at
those rich in cortical bone. Bone loss varied according to skeletal site from 14%
to 43%. The variability of BMD increased with age, which may reflect
interindividual variability of age-related bone loss.
PMID- 10678407
TI - Cross-sectional and longitudinal assessment of pre- and postmenopausal bone loss
with a portable forearm X-ray device: the Ofely study.
AB - The aim of our study was to describe cross-sectional and longitudinal bone
mineral decrease in pre-, peri-, and postmenopausal healthy women using a
monoenergy X-ray densitometer specifically designed for forearm assessement.
Measurements were performed on the most distal part of the radius (ultradistal,
55% of trabecular bone and 45% of trabecular bone), and on the distal part
(distal, 13% of trabecular bone and 87% of cortical bone). A specific trabecular
rich region of interest (nROI) comprising two trapezoids regions of interest
located proximally to the endplates of the radius and ulna was also investigated.
From a large prospective study (OFELY study), 455 women were measured once a year
for 2 years (three measurements). The proportion of postmenopausal women
classified as having osteoporosis (i.e., a T score <-2.5) was 33% for the distal
region, 44% for the ultradistal region, and 45% for the nROI. No significant bone
mineral decrease was found over the 2-year period in premenopausal women (n =
138). In perimenopausal (n = 48) women, a bone loss of 1% was found at the distal
site. In the 269 postmenopausal women, a significant decrease was observed at all
sites, ranging from 2.14% for the nROI to 2.68% for the ultradistal part. Bone
loss was greater in the first 5 years after menopause in trabecular sites and
decreased thereafter. For the distal site, bone loss remained stable during the
postmenopausal period. We conclude that this small and portable forearm
densitometer is suitable for the diagnosis of osteoporosis, and provides
information on the rate of bone loss in peri- and postmenopausal women in
trabecular and cortical compartments of bone.
PMID- 10678408
TI - Cytokine RNA levels in transiliac bone biopsies from healthy early postmenopausal
women.
AB - The cytokines interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF
alpha), and IL-6 induce osteoclast formation and may contribute to the
development of postmenopausal osteoporosis. Cross-sectional studies have
suggested that both IL-1 and IL-1ra secretion increase on estrogen withdrawal,
and that postmenopausal osteoporosis is associated with an inadequate increase in
monocyte IL-1ra secretion with age. We measured cytokine mRNA (IL-1beta, IL-1ra,
IL-6, and TNF-alpha) directly in bone biopsies from early postmenopausal women to
determine if a lower compensatory increase in IL-1ra mRNA could be demonstrated
in women with rapid bone loss after the menopause. Biopsies were obtained from 23
early postmenopausal women (mean age 53.9 years) who participated in a randomized
study of hormone replacement therapy (HRT) and risk factors for osteoporosis.
Bone mineral density was assessed by duel energy X-ray absorptiometry at 0, 1, 2,
and 5 years. Women in the control group were recruited to the biopsy study based
on their observed rate of bone loss (upper or lower tertile). Consent was also
obtained from 11 participants receiving HRT. Biopsies were taken at 2 years,
frozen in nitrogen, and homogenized. Cytokine mRNA was measured by competitive
reverse transcriptase polymerase chain reaction. The IL-1ra/IL-1beta mRNA slope
for the slow-loss group was steeper (deltaF = 23.3, p < 0.01) than that observed
in the fast-loss group, indicating that slower bone loss was associated with
higher IL-1ra mRNA levels relative to IL-1beta. During HRT, the IL-1beta mRNA
level was inversely correlated with serum estradiol (log r2 = 0.77, p < 0.01),
and women with a serum estradiol below 200 pmol/L during HRT had IL-1beta, mRNA
levels identical to the control group. In contrast, IL-1ra mRNA was independent
of serum estradiol. Histomorphometric analysis revealed weak correlations between
IL-1beta mRNA and activation frequency (r2 = 0.26, p = 0.06) and between IL-1ra
and volume referent bone resorption rate (r2 = 0.19, p = 0.11). TNF-alpha was not
associated with the bone loss rates or with serum estradiol, and only three
samples were positive for IL-6 mRNA. The findings support the hypothesis that IL
1beta production within bone increases with declining estrogen levels, and that
an increase in II-1ra protects against accelerated bone loss.
PMID- 10678409
TI - In vivo diffuse damage in human vertebral trabecular bone.
AB - Accumulation of microdamage in vivo may lead to loss of bone quality. Until
recently, linear microcracks were the only known form of in vivo microdamage, but
through the use of confocal microscopy an additional level of damage (diffuse
damage) has been identified. In this study, in vivo diffuse damage was
characterized and quantified in human vertebral trabecular bone as a function of
tissue morphology, age, race, gender, and previously quantified in vivo linear
microcracks. Presence of diffuse damage in human vertebral tissue was confirmed
and validated by simultaneous use of polarized, ultraviolet, and laser confocal
microscopy. Diffuse damage was found to occur preferentially within trabecular
packets rather than in interstitial bone (p < 0.05). It was consistently higher
in men compared with women (p < 0.05), but was not different by race or age
group. Diffuse damage did not correlate with linear microcracks, but both
exhibited the same probability distribution in which the percentage of
individuals having a particular amount of damage decreased exponentially as
damage content increased. These findings suggest that diffuse damage accumulation
and repair are governed by the same biological phenomena as microcracks, but
diffuse damage contributes independently to the microdamage content of bone.
PMID- 10678410
TI - Does the mechanical milieu associated with high-speed running lead to adaptive
changes in diaphyseal growing bone?
AB - Exercise during growth can be important for attaining optimal bone mass. High
intensity long-duration protocols, however, can have detrimental effects on
immature bone morphology and mechanics. The underlying mechanisms are poorly
understood. Here, we quantified the mechanical environment of the middiaphyseal
rooster tarsometatarsus during high-speed running and examined whether short
bouts of this exercise-related mechanical milieu can induce positive changes in
cortical bone morphology, mechanics, and mineral ash content. At 9 weeks of age,
roosters were assigned to controls (n = 9) and runners (n = 8). Treadmill running
was applied in loading sessions of 5 min, three times per day (approximately 2600
cycles/day) for 8 weeks. Both controls and runners received double-fluorochrome
labels during weeks 3 and 8 of the protocol. Middiaphyseal distributions of
tarsometatarsal longitudinal normal strain, strain rate, and strain gradients
engendered by walking and running were determined via in vivo strain gauges.
Compared with walking, running elevated mean peak strain magnitude by 19%, peak
strain rates by 136%, and peak strain gradients by approximately 18%. After 8
weeks of running, middiaphyseal areal and mechanical properties and normalized
ash weight were no different between runners and controls. Transient and focal
reductions in periosteal mineral apposition rates occurred during the exercise
protocol. Our current data suggest that reducing the number of loading cycles can
mitigate the adverse response previously observed in this model with long
duration running. This study also supports the tenet that the exercise-generated
mechanical milieu must differ substantially from the habitual milieu to induce
significant adaptations.
PMID- 10678411
TI - Effects of recombinant human fibroblast growth factor-2 on osteogenic cell
populations during orthopic osteogenesis in vivo.
AB - The osteogenic effects of fibroblast growth factor-2 (FGF-2) in vivo on different
cell populations of the osteoblastic cell lineage have not been fully elucidated.
In this study, the efficacy of recombinant human fibroblast growth factor-2
(rhFGF-2) to stimulate orthopic bone formation in transosseous rat mandibular
defects, with different cell populations allowed access to the defects, was
investigated with the aim to further decipher FGF-2 effects. Three different
doses of rhFGF-2 (10 ng, 100 ng, and 1 microg) were delivered in an absorbable
collagen sponge carrier, whereas some defects were implanted with the carrier
only, and some were left untreated. Barrier membranes, made of microporous
expanded polytetrafluoroethylene, were simultaneously placed over half the number
of defects in each treatment group, thus forcing osteogenic cells to be derived
from intraosseous sources. Evaluation was made by light microscopy and
computerized image analysis after 12 and 24 of days healing. Whereas no general
stimulatory effect could be ascertained at 12 days, higher rhFGF-2 doses
decreased bone formation by both intraosseously and periosteally derived cells.
At 24 days, a clear, although rather limited, stimulatory effect on osteogenesis
was observed, but again a decrease was observed with the 1 microg dose. At both
observation periods, an increased number of osteocytes was found in the newly
formed bone at sites treated with the lower rhFGF-2 doses, whereas the high-dose
rhFGF-2 resulted in a return to control levels, irrespective of whether cells
were intraosseously derived or from the periosteum also. Based on differential
analysis of bone healing by cells from different sources as well as on bone
cellularity, the results suggest that rhFGF-2 in vivo exerts a stimulatory effect
on proliferation of committed osteoblastic cells. This effect is biphasic, in
that higher doses are without effect or may even be inhibitory. No inductive
effect on osteoblast recruitment could be found. These effects differ from those
of, for instance, BMP-2 and TGF-beta1.
PMID- 10678412
TI - Bone stiffness predicts strength similarly for human vertebral cancellous bone in
compression and for cortical bone in tension.
AB - The yield strength and ultimate strength of cortical and cancellous bone tissue
are very highly correlated to bone stiffness. For samples of human vertebral
cancellous bone in compression and for bovine cortical bone in tension, the
coefficient of determination (r2) for regression between ultimate strength and
stiffness was 0.89 and 0.92, and between yield strength and stiffness it was 0.94
and 0.93, respectively. The slope of the regression for human vertebral
cancellous bone ultimate strength predicted by stiffness was not statistically
different from similar regressions for cortical bone in tension in either a
bovine sample or in published data from multiple species. We believe that the
observed correlation results from the evolutionary need to build sufficiently
strong bones using cells that are sensitive to deformation and that directly
control bone stiffness, but not strength. The practical significance of this work
is that an in vivo estimate of bone stiffness (e.g., from ultrasound measurement)
may be a surrogate for bone strength.
PMID- 10678413
TI - Daily intermittent decreases in serum levels of parathyroid hormone have an
anabolic-like action on the bones of uremic rats with low-turnover bone and
osteomalacia.
AB - The calcium receptor agonist (calcimimetic) compound NPS R-568 causes rapid
decreases in circulating levels of parathyroid hormone (PTH) in rats and humans.
We hypothesized that daily intermittent decreases in serum PTH levels may have
different effects on bone than do chronically sustained decreases. To test this
hypothesis, we compared two NPS R-568 dosing regimens in rats with chronic renal
insufficiency induced by two intravenous injections of adriamycin. Fourteen weeks
after the second adriamycin injection, creatinine clearance was reduced by 52%,
PTH levels were elevated approximately 2.5-fold, and serum 25(OH)D3 and
1,25(OH)2D3 levels were reduced substantially. Treatment by daily per os gavage,
which decreased PTH levels intermittently, or continuous subcutaneous infusion,
which resulted in a sustained suppression of serum PTH levels, then began for 8
weeks. Despite the hyperparathyroidism, the adriamycin-injected rats developed a
low-turnover bone lesion with osteomalacia (fourfold increase in osteoid volume
in the proximal tibial metaphysis) and osteopenia (67% decrease in cancellous
bone volume and an 18% reduction in bone mineral density at the distal femur).
Daily administered (but not infused) NPS R-568 significantly increased cancellous
bone volume solely by normalizing trabecular thickness, and increased femoral
bone mineral density by 14%. These results indicate that daily intermittent, but
not sustained, decreases in PTH levels have an "anabolic-like" effect on bones
with a low-turnover lesion in this animal model of chronic renal insufficiency.
PMID- 10678414
TI - A murine model of inflammatory bone disease.
AB - We have recently reported the identification of a new recessive mutation on
murine chromosome 18 that results in tail kinks and deformity in the lower
extremities of mice. Preliminary examination of the bones of these mice showed
that there are abnormalities present that resembled chronic recurrent multifocal
osteomyelitis. Accordingly, this new mutation was named "CMO." In this report, we
describe the histology of bones in CMO mice, as well as the capacity of the bone
marrow cells from these animals to form osteoclasts (OCLs). In addition, we
tested conditioned media from non-adherent marrow cells and total marrow cells
from CMO mice for their capacity to induce OCL formation in normal murine marrow
cultures. These studies demonstrated that the bone disease in these animals is
inflammatory in nature, and a soluble factor(s) that is not IL-1alpha, IL-6 or
TNF-alpha is released by marrow cells from CMO animals and enhances OCL formation
in normal murine marrow cultures.
PMID- 10678415
TI - Relationships between bone protein and mineral in developing porcine long bone
and calvaria.
AB - Several proteins in the bone matrix have been implicated in the regulation of
mineral crystal formation and growth. To investigate the relationships between
these proteins and the mineral phase at various stages of mineral maturation,
fetal porcine calvariae and long bones were fragmented and the particles (20
microm) separated by density gradient sedimentation into fractions of increasing
density (1.8 to >2.2 g/cm3). Samples from each fraction were analyzed by X-ray
diffraction to obtain the average crystal size/strain and chemical composition.
Other samples were sequentially extracted, first with 4.0 mol/L guanidium
hydrochloride (GuHCl) (G1), then with 0.5 mol/L ethylene-diamine tetraacetic acid
(EDTA) (E), and again with 4.0 mol/L Gu-HCI (G2), for analysis of proteins in
different tissue compartments. Based on the mineral density distribution and
crystal size, fetal porcine bone protein content was determined for tissue
residue and each extract and the protein composition analyzed by sodium dodecyl
polyacrylamide gel electrophoresis (SDS-PAGE). Although the insoluble organic
matrix decreased with mineral density the collagen and protein content remained
fairly constant, representing approximately 10% of the tissue weight, except in
the highest density fraction. Whereas the total extractable protein, representing
predominantly noncollagenous proteins, did not show density-related differences,
differences were observed for individual proteins on SDS-PAGE. Consistent with
their presence in osteoid, the content of bone sialoprotein (BSP), tyrosine-rich
acidic matrix protein (TRAMP), and a series of small proteins with cell
attachment properties in the G1 extract decreased with mineral density, whereas
TRAMP and BSP were increased in G2 extracts. Mineral-associated proteins,
including alpha2HS-glycoprotein, BSP, osteopontin (OPN), and osteocalcin,
increased with mineral density, whereas secreted protein acidic and rich in
cysteine (SPARC)/osteonectin, and some minor proteins, appeared to decrease.
Differences of individual proteins within and between the calvarial and long
bones could be related to the role of these proteins in the formation and
maturation of hydroxyapatite crystals. Collectively, these studies demonstrate
mineral density-associated changes in protein composition that reflect a rapid
maturation of mineral crystals in embryonic porcine bones.
PMID- 10678416
TI - Criteria used to identify osteoclasts formed in vitro.
PMID- 10678417
TI - Multidrug-resistant Salmonella Typhimurium DT104 in poultry.
AB - Salmonella Typhimurium isolates from feed ingredients or poultry sources isolated
during 1995 to 1997 from different geographical locations within Minnesota were
examined for the presence of Salmonella Typhimurium definitive type 104 (DT104).
Antibiotic susceptibility studies indicated that 15 of 50 isolates of Salmonella
Typhimurium had an antibiotic resistance pattern (ampicillin, chloramphenicol,
streptomycin, sulfonamides, and tetracycline) that is usually observed with
multidrug-resistant Salmonella Typhimurium DT104. Of the 15 isolates showing the
antibiotic resistance pattern, 8 isolates were phage type 104, 3 isolates were
typed as phage type 104 complex, and the remaining 4 isolates belonged to phage
types 193, 81, and 126. DT104 was recovered from both feed ingredients and
poultry samples. Of the seven feed ingredient-associated Salmonella Typhimurium
isolates, four were DT104, whereas only 7 of 43 poultry-associated Salmonella
Typhimurium isolates were DT104. A repetitive sequence-based polymerase chain
reaction (rep-PCR) of 50 isolates of Salmonella Typhimurium representing 13 phage
types identified seven distinct fingerprint profiles. No correlation between
phage type and rep-PCR type was noticed. Eleven Salmonella Typhimurium isolates
belonging to DT104 and its complex were grouped into two closely related rep-PCR
types.
PMID- 10678418
TI - Survival of Pseudomonas fluorescens and Salmonella typhimurium after electron
beam and gamma irradiation of refrigerated beef.
AB - The radurization effects of gamma ray and electron beam irradiation at 1.5 and
3.0 kGy on beef steaks inoculated with Salmonella Typhimurium and Pseudomonas
fluorescens were investigated during 8 days of storage at 5 degrees C. Total
bacterial counts and numbers of Salmonella Typhimurium and P. fluorescens were
analyzed at 2-day intervals. Total bacterial counts of samples irradiated by both
gamma rays and electron beam were significantly (P < 0.05) reduced by 3.8 to 5.3
log CFU/g. Salmonella Typhimurium was not detectable during the experimental
period. P. fluorescens counts of beef samples irradiated by gamma rays at both
1.5 and 3.0 kGy were not detected; however, P. fluorescens in samples irradiated
by electron beam at 1.5 and 3.0 kGy was recovered after 2 days, and bacterial
counts reached 7.8 and 6.9 log CFU/g, respectively. Both gamma ray and electron
beam irradiation reduced total bacterial counts initially, possibly extending
shelf life. Irradiation was very effective in destroying Salmonella Typhimurium;
however, P. fluorescens was not completely eliminated by electron beam
irradiation. Consequently, gamma ray irradiation was more effective than electron
beam irradiation in the destruction of P. fluorescens.
PMID- 10678419
TI - Microbiological sampling of carcasses by excision or swabbing.
AB - Groups of 25 carcasses were obtained by random selection of carcasses at the end
of each of eight commercial processes for the dressing or cooling of carcasses.
Samples were collected from six groups of pig or beef carcasses by excision or
swabbing with sponge, gauze, or cotton wool, with one sample obtained by each of
the four methods from a separate, randomly selected site on each carcass. Total
aerobic counts, coliforms, and Escherichia coli from each sample were enumerated.
Values for the mean log10, log10 mean, and log10 total numbers recovered were
calculated for each set of total aerobic counts. Those statistics indicated that
the numbers of bacteria recovered by excision or swabbing with sponge or gauze
were similar, while the numbers recovered by swabbing with cotton wool were at
the lower end of or below the range of the numbers recovered by the other
methods. The numbers of coliforms or E. coli recovered from carcasses by sampling
areas up to 100 cm2 were too few for the estimation of log mean numbers. Sampling
of two groups of carcasses by swabbing with gauze indicated that each 10-fold
increase in the area sampled, from 10 to 1,000 cm2, approximately doubled the
number of samples from which coliforms or E. coli were recovered. Sampling of six
groups of carcasses from one process indicated that the sizes of swabs and
volumes of diluent used for processing swabs did not have to be increased
proportionally to the area of carcass surface sampled to recover numbers of E.
coli proportional to the sampled area. It therefore appears that carcass sampling
techniques can be varied widely without compromising the recovery of bacteria,
and that the relative efficiencies with which bacteria are recovered by different
techniques can be assessed by sampling each carcass in a group of 25 by each of
the methods to be compared.
PMID- 10678420
TI - Attempts to isolate Helicobacter from cattle and survival of Helicobacter pylori
in beef products.
AB - This study focused on important factors related to the potential of cattle and
beef products to transmit Helicobacter pylori to humans. Mucosal samples were
collected from the rumen and abomasum of 105 cattle and were plated on a
selective medium to isolate Helicobacter spp.; none of the samples examined
contained these bacteria. Studies were also conducted to determine how long H.
pylori survives in refrigerated or frozen ground beef; results indicated that the
microorganism dies rapidly in ground beef, whether refrigerated or frozen.
Packaging in vacuum or air had little effect on survival of the organism. The
number of H. pylori decreased in refrigerated samples from 3.3 log10 CFU/g on day
0 to 1.4 log10 CFU/g on day 6. H. pylori died even more rapidly when frozen,
decreasing from 3.3 log10 CFU/g on day 0 to 0.5 log10 CFU/g on day 6. Retail beef
cuts (n = 20) were also examined for the presence of H. pylori by direct plating
on a selective medium and by incubation in an enriched broth followed by plating
on a selective medium. None of the retail samples contained H. pylori. This
research suggests that transmission of H. pylori from beef and beef products is
not a primary factor in the high prevalence of this bacterium in humans.
PMID- 10678421
TI - Ribotype analysis of strain distribution in Listeria monocytogenes.
AB - Changes in the temporal and spatial patterns of strain distribution for the
foodborne pathogen Listeria monocytogenes were studied by ribotyping using the
Qualicon Riboprinter system. Ribotype patterns were obtained by using the
restriction enzymes EcoRI and PvuII for 72 isolates of L. monocytogenes recovered
from smoked salmon samples over a period of 3 years. Each pattern was classified
both by comparison to a pattern library and by comparison among the 72 isolate
patterns. Eleven EcoRI-based ribogroups and 16 PvuII groups were identified.
Eight of the 11 EcoRI ribogroups were found in isolates obtained over a period of
>12 months, and 75% of the EcoRI ribogroups that were found in more than one food
sample were distributed nationally. Within the set of isolates, there were 26
instances where more than one isolate was obtained from a single food sample. In
35% of these instances, the co-isolates produced different ribotype patterns,
indicating that multiple strains of L. monocytogenes commonly coexist in the same
environment. Overall, these data indicate that the population of L. monocytogenes
consists of a number of widely dispersed strains with little geographic or
temporal stratification.
PMID- 10678422
TI - Incidence and characterization of Listeria monocytogenes from domestic and
imported foods in Korea.
AB - A total of 1,537 domestic and imported food products were examined for the
incidence of Listeria monocytogenes between 1993 and 1997 in Korea. L.
monocytogenes was detected using the U.S. Department of Agriculture isolation
method. Isolated L. monocytogenes was confirmed by polymerase chain reaction with
hly1 and hly2 primers designed from the listeriolysin O. Overall, 122 samples
(7.9%) contained L. monocytogenes. The rate of isolation was 4.3% for beef, 19.1%
for pork, 30.2% for chicken, 1.2% for shellfish, 4.4% for raw milk, 4.4% for
frozen smoked mussels, and 6.1% for ice cream. No L. monocytogenes was found in
pasteurized milk, pasteurized processed cheese, saltwater fish, dried seafoods,
or ham. The overall incidence was lower than that reported in previous studies
from other countries. Most isolates were serotype 1/2b except for chicken, in
which serotype 1/2a was predominant. The serotyping results might imply the
presence of food or geography-specific L. monocytogenes strains.
PMID- 10678423
TI - Estimating the survival of Clostridium botulinum spores during heat treatments.
AB - A recently published study of the inactivation of Clostridium botulinum spores at
various temperatures in the range of 101 to 121 degrees C and neutral pH revealed
that their semilogarithmic survival curves all had considerable upward concavity.
This finding indicated that heat inactivation of the spores under these
conditions did not follow a first-order kinetics and that meaningful D values
could not be calculated. The individual survival curves could be described by the
cumulative form of the Weibull distribution, i.e., by log S = -b(T)t(n(T)), where
S is the survival ratio and b(T) and n(T) are temperature-dependent coefficients.
The fact that at all temperatures in the above range n(T) was smaller than 1
suggested that as time increases sensitive members of the population parish and
survivors with increasing resistance remain. If damage accumulation is not a main
factor, and the inactivation is path independent, then survival curves under
monotonously increasing temperature can be constructed using a relatively simple
model, which can be used to calculate the spores' survival in a limiting case.
This is demonstrated with computer-simulated heating curves and the experimental
constants of the C. botulinum spores, setting the number of decades reduction to
8, 10, and 12 (the current criterion for commercial sterility).
PMID- 10678424
TI - Oyster preservation by high-pressure treatment.
AB - The purpose of this study was to analyze the effect of 10-min continuous pressure
and pulsed pressure in two 5-min steps (400 MPa at 7 degrees C) on the microbial
flora, total volatile bases, pH, and texture of purified and unpurified oysters.
High-pressure treatment reduced the number of all the target microorganisms
(total viable count, H2S-producing microorganisms, lactic acid bacteria,
Brochothrix thermosphacta, and coliforms), in some cases by around 5-log units.
The difference between the counts in the control and the pressurized oysters
remained stable throughout 41 days of storage at 2 degrees C. No Salmonella spp.
were detected in either the control batch or the pressurized batches during this
storage period. Deterioration of the oyster was accompanied by increased total
volatile bases, mainly in the nonpressurized samples. The pH was practically
constant in the pressurized oysters and fell slightly in unpressurized samples.
As for mechanical properties, shear strength values were higher in pressurized
than in unpressurized oysters. Step-pulse pressurizing (400 MPa at 7 degrees C in
two 5-min pulses) produced no apparent advantages over continuous pressurizing
based on any of the indices used.
PMID- 10678425
TI - The antimicrobial properties of chitosan in mayonnaise and mayonnaise-based
shrimp salads.
AB - The potential for using chitosan glutamate as a natural food preservative in
mayonnaise and mayonnaise-based shrimp salad was investigated. Mayonnaise
containing 3 g/liter of chitosan combined with acetic acid (0.16%) or lemon juice
(1.2 and 2.6%) was inoculated with log 5 to 6 CFU/g of Salmonella Enteritidis,
Zygosaccharomyces bailii, or Lactobacillus fructivorans and stored at 5 and 25
degrees C for 8 days. In mayonnaise containing chitosan and 0.16% acetic acid, 5
log CFU/g of L. fructivorans were inactivated, and numbers remained below the
sensitivity limit of the plate counting technique for the duration of the
experiment. Z. bailii counts were also reduced by approximately 1 to 2 log CFU/g
within the first day of incubation at 25 degrees C, but this was followed by
growth on subsequent days, giving an overall growth delay of 2 days. No
differences in counts of Z. bailii in mayonnaise stored at 5 degrees C or of
Salmonella Enteritidis stored at either temperature were observed. In mayonnaise
containing lemon juice at both 1.2 and 2.6%, no substantial differences were
observed between the controls and the samples containing chitosan. In shrimp
salads stored at 5 degrees C, the presence of a coating of chitosan (9 mg/g of
shrimp) inhibited growth of the spoilage flora from approximately log 8 CFU/g in
the controls to log 4 CFU/g throughout 4 weeks. However, at 25 degrees C,
chitosan was ineffective as a preservative. The results demonstrated that
chitosan may be useful as a preservative when combined with acetic acid and chill
storage in specific food applications.
PMID- 10678426
TI - Microbial testing methods for detection of residual cleaning agents and
disinfectants-prevention of ATP bioluminescence measurement errors in the food
industry.
AB - The ATP luminescence measurement is based on the presence of an enzymatic
reaction and may significantly be affected by cleaning agents and disinfectants.
In addition, disinfectants can also reduce the activity of the luciferase enzyme
and also act as ATP-releasing agents. The agents disrupt the cell walls but
preserve ATP in measurable form, and therefore correlation with culture methods
can be poor. Therefore, if a rapid method is used to detect ATP, a control must
be used for reliable results. The possible effect of disinfectants can be
eliminated with a rapid test to minimize sources of error. In the present study a
microbiological residue testing method that is nonspecific for residues was
developed. The effects of a total of 38 commercial cleaning agents and
disinfectants of various types were assessed using two microbiological methods,
the Vibrio fischeri photobacteria test and Micrococcus luteus inhibition zone
technique. The results show that the V. fischeri photobacteria test is very
sensitive. This test can therefore be used for testing cleaning agent residues on
surfaces in very small amounts. A small study was also carried out in a food
factory to show applicability in processing facilities. The study showed, that a
need for this type of method exists in food processing.
PMID- 10678427
TI - Characterization of whey cheese packaged under vacuum.
AB - Vacuum packaging was assayed at 4 degrees C and was tested in comparison to
unpackaged counterparts, in both microbiological and physicochemical terms, in
studies pertaining to the preservation of Requeijao, a traditional Portuguese
whey cheese. Bacteria were absent (i.e., <10 CFU/g) in whey cheeses on the day of
manufacture as a result of thermal processing. After storage, both unpackaged and
packaged cheeses exhibited high viable counts of Bacillus, Pseudomonas,
Enterobacteriaceae, and lactic acid bacteria (especially lactococci). Yeasts,
staphylococci, enterococci, and spore-forming clostridia were severely inhibited
by the package vacuum combined with the increasing acidification developed
therein. Whey cheeses packaged under vacuum underwent substantial acidification,
slight depletion of lactose, and no significant variation in moisture content or
texture; conversely, unpackaged whey cheeses exhibited substantial loss of water
and a concomitant increase in rigidity. Vacuum packaging strongly inhibited
lipolysis (even if viable counts of some microbial groups were high); saturated
fatty acids (mainly C16:0 and C14:0) accounted for ca. 73% of the total free
fatty acid content, whereas the most concentrated unsaturated fatty acids were
C18:1 and C18:2 (ca. 14% each). The conclusions generated in our study are, in
general, useful for a wide range of whey cheeses worldwide: i.e., Requeson
(Spain), Ricotta (Italy), Broccio (France), and Anthotyro (Greece). In addition,
our conclusions are particularly helpful in terms of improving the safety of
Requeijao, a widely acclaimed dairy specialty.
PMID- 10678428
TI - The boundary for growth of Zygosaccharomyces bailii in acidified products
described by models for time to growth and probability of growth.
AB - Models to predict days to growth and probability of growth of Zygosaccharomyces
bailii in high-acid foods were developed, and the equations are presented here.
The models were constructed from measurements of growth of Z. bailii using
automated turbidimetry over a 29-day period at various pH, NaCl, fructose, and
acetic acid levels. Statistical analyses were carried out using Statistical
Analysis Systems LIFEREG procedures, and the data were fitted to log-logistic
models. Model 1 predicts days to growth based on two factors, combined molar
concentration of salt plus sugar and undissociated acetic acid. This model allows
a growth/no-growth boundary to be visualized. The boundary is comparable with
that established by G. Tuynenburg Muys (Process Biochem. 6:25-28, 1971), which
still forms the basis of industry assumptions about the stability of acidic
foods. Model 2 predicts days to growth based on the four independent factors of
salt, sugar, acetic acid, and pH levels and is, therefore, much more useful for
product development. Validation data derived from challenge studies in retail
products from the U.S. market are presented for Model 2, showing that the model
gives reliable, fail-safe predictions and is suitable for use in predicting
growth responses of Z. bailii in high-acid foods. Model 3 predicts probability of
growth of Z. bailii in 29 days. This model is most useful for spoilage risk
assessment. All three models showed good agreement between predictions and
observed values for the underlying data.
PMID- 10678429
TI - Effects of substrate, water activity, and temperature on growth and verrucosidin
production by Penicillium polonicum isolated from dry-cured ham.
AB - Penicillium polonicum, a common mold on dry-cured meat products, is able to
produce verrucosidin, a potent neurotoxin. The ability of P. polonicum isolated
from dry-cured ham to grow and produce verrucosidin from 4 to 40 degrees C at
water activities (a(w)) of 0.99, 0.97, and 0.95 on malt extract agar (MEA) and a
medium made up with meat extract, peptone, and agar (MPA) was evaluated.
Verrucosidin was quantified by high-pressure liquid chromatography and mass
spectrometry. P. polonicum was able to grow on MEA and MPA at all the a(w) values
tested from 4 to 37 degrees C but not at 40 degrees C. The optimal environmental
conditions for growth were 20 degrees C, 0.99 a(w) on MEA and 20 to 25 degrees C,
0.97 a(w) on MPA, but the highest amount of verrucosidin was obtained at 25
degrees C, 0.99 a(w) in both media. No direct correlation between extension of
mold growth and verrucosidin production was found. Temperature appears to be the
most important factor ruling mycelial growth, whereas verrucosidin accumulation
is mostly influenced by a(w). However, analysis of variance of the data showed
that there was a complex interaction among all the environmental factors (medium,
temperature, and a(w)) that significantly (P < 0.0001) affected growth and
verrucosidin production. The reduction of a(w) to intermediates values of 0.95
has a stronger effect on growth on MEA than on MPA. Given that the meat-based
medium proved to be an appropriate substrate for the biosynthesis of verrucosidin
by P. polonicum, the ability of this mold to produce the toxin on meat products
should be established.
PMID- 10678430
TI - Reduction of biogenic amine formation using a negative amino acid-decarboxylase
starter culture for fermentation of Fuet sausages.
AB - The ability of Lactobacillus sakei CTC494, a negative amino acid-decarboxylase
starter culture, to reduce biogenic amine accumulation during sausage
fermentation and storage at 4 and 19 degrees C was studied. The effect on the
amine formation of the tyramine producer Lactobacillus curvatus CTC371, as a
positive strain, was also examined in comparison to a spontaneous fermentation
process without starter culture (control batch). The polyamines spermine,
spermidine, and diaminopropane were not influenced by the ripening, and their
levels slightly decreased in all the batches throughout the storage. Tyramine,
cadaverine, and putrescine were the main amines formed during the ripening. The
addition of starter culture resulted in a decrease on the biogenic amine
formation, depending on the strain inoculated. A great reduction in tyramine
content was achieved when L. sakei CTC494 was inoculated, whereas L. curvatus
CTC371 only attenuated tyramine accumulation compared with the control batch.
Both starters were able to significantly limit the production of putrescine and
cadaverine, and they inhibited tryptamine and phenylethylamine formation by the
wild microbial flora. Tyramine levels of the control sausages rose during the
storage at both temperatures, whereas those of cadaverine only increased at 19
degrees C. On the contrary, sausages manufactured through the starter controlled
fermentation did not show changes of amine contents during the storage. The
addition of a proper selected starter culture is advisable to produce safer
sausages with low contents of biogenic amines.
PMID- 10678431
TI - Histamine and biogenic amine production by Morganella morganii isolated from
temperature-abused albacore.
AB - Histamine-producing bacteria were isolated from albacore stored at 0, 25, 30, and
37 degrees C. They were screened using Niven's differential medium, and their
histamine production was confirmed by high-pressure liquid chromatography
analysis. The optimum temperature for growth of histamine-producing bacteria was
25 degrees C. The bacterium producing the highest level of histamine was isolated
from fish abused at 25 degrees C. It was identified as Morganella morganii by
morphological, cultural, biochemical, and antimicrobial characteristics and by
the Vitek microbial identification system. The M. morganii isolate was inoculated
into tuna fish infusion broth medium, and the effect of temperature was
determined for microbial growth and formation of histamine and other biogenic
amines. The isolate produced the highest level of histamine, 5,253 ppm, at 25
degrees C in the stationary phase. At 15 degrees C, histamine production was
reduced to 2,769 ppm. Neither microbial growth nor histamine formation was
detected at 4 degrees C. To determine whether the isolate can also produce other
biogenic amines that can potentiate histamine toxicity, production of cadaverine,
putrescine, serotonin, tryptamine, tyramine, phenylethylamine, spermidine, and
spermine by the isolate was also monitored. Cadaverine, putrescine, and
phenylethylamine were detected with microbial growth in the tuna fish infusion
broth medium. The optimum temperature for cadaverine, putrescine, and
phenylethylamine formation was found to be 25 degrees C, as it was for histamine.
PMID- 10678432
TI - A sandwich enzyme-linked immunosorbent assay for the detection of almonds in
foods.
AB - An enzyme-linked immunosorbent assay was developed to detect almonds as potential
allergenic contaminants in food. Polyclonal antibodies directed against roasted
almonds were partially purified from immunized sheep and rabbits and used as
capture and secondary antibodies, respectively, in a sandwich-type, 96-well plate
format. Food samples and almond-spiked samples were extracted 1:10 in phosphate
buffered saline at 60 degrees C for 2 h, centrifuged, and applied to wells coated
with sheep anti-almond antibody. After incubation, washing, and the addition of
rabbit anti-almond antibody, the amount of almond present was detected with the
subsequent addition of goat anti-rabbit immunoglobulin G-alkaline phosphatase
conjugate and p-nitrophenyl phosphate substrate. Plate absorbances were read at
410 nm, and standard curves were developed in all matrices to quantify unknowns.
Antibodies developed were specific for almond; however, some cross-reactivity was
observed with extracts of some tree nuts and sesame seeds. Sodium dodecylsulfate
polyacrylamide gel electrophoresis and Western immunoblotting indicated that
sheep anti-almond antibody recognized proteins extracted from black walnuts,
Brazil nuts, cashews, hazelnuts, macadamia nuts, pistachios, and sesame seeds in
addition to those from almond. The assay was optimized to detect less than 1 ppm
of almond and was used successfully to determine almond residues in cereal and
chocolate without cross-reacting interferences. A retail survey of 20 brands of
cereal demonstrated that the assay produced statistically consistent results.
This assay provides a useful quality control tool for the food industry for the
protection of consumers allergic to almonds.
PMID- 10678433
TI - Identification of central nervous system tissue in retail meat products.
AB - A procedure to detect tissues from the central nervous system that involved
quantification of cholesterol and immunochemical detection of neuron-specific
enolase and glial fibrillary acidic protein was used to analyze 402 samples of
heat-treated meat products from various food outlets in Germany. The cholesterol
content of 16 samples (4.0%) indicated the possible presence of central nervous
system tissue because the levels exceeded the normal maximum cholesterol content
of cooked sausages. In 7 of these 16 heat-treated meat products, immunoblotting
of both neuron-specific enolase and glial fibrillary acidic protein confirmed the
presence of CNS tissue. Repeated sampling by veterinary officials and analysis by
both cholesterol quantification and immunoblotting confirmed these findings.
Whereas all of the control samples (with and without added central nervous system
tissue) were correctly classified by both cholesterol quantification and
immunoblotting, negative results of immunoblotting must be carefully interpreted
in the case of intensively heat-treated meat products. Thus, studies have yet to
establish an increase in sensitivity of immunoblotting of neuron-specific enolase
and glial fibrillary acidic protein. However, the detection of illegal use of
central nervous system tissue in heat-treated retail meat products demonstrates
the need for suitable analytical methods to control transmissible
encephalopathies and to enforce labeling laws.
PMID- 10678434
TI - Specificity of a conductance assay for enumeration of Escherichia coli from
broiler carcass rinse samples containing genetically similar species.
AB - Experiments were conducted to evaluate the specificity of a rapid method for
enumeration of Escherichia coli from fresh broiler chicken carcasses. In three
separate trials, E. coli, Citrobacter freundii, Salmonella Enteritidis, and
Shigella sonnei were serially diluted and then inoculated into identical broiler
chicken carcass rinses. Inoculated rinses were mixed with double-strength
Coliform Medium supplemented with 2% dextrose. This mixture was placed in a
Bactometer module in duplicate, and conductance was measured at 44 degrees C.
Results indicated that C. freundii did not grow to an appreciable degree in the
selective medium at 44 degrees C. Salmonella Enteritidis grew similarly to E.
coli; however, an initial level of 10(6) Salmonella in the food product would be
required for Salmonella to interfere with enumeration of E. coli using this
method. S. sonnei grew at a more rapid rate than E. coli; however, there was an
interaction between the regression lines formed when serial dilutions (log10
CFU/ml) were compared to E. coli detection times for these two species of
bacteria. Therefore, high levels of S. sonnei in a food sample may interfere with
the enumeration of E. coli. In general, Salmonella and Shigella are not found at
high enough levels on poultry products to interfere with enumeration of E. coli
using this method and, if found at high levels, would be detected and rejected
using this procedure. Hence, the presence of organisms that are genetically and
phylogenetically similar to E. coli would not preclude enumeration of E. coli
using conductance under these conditions.
PMID- 10678435
TI - Validation and analysis of modeled predictions of growth of Bacillus cereus
spores in boiled rice.
AB - The growth of psychrotrophic Bacillus cereus 404 from spores in boiled rice was
examined experimentally at 15, 20, and 30 degrees C. Using the Gompertz function,
observed growth was modeled, and these kinetic values were compared with kinetic
values for the growth of mesophilic vegetative cells as predicted by the U.S.
Department of Agriculture's Pathogen Modeling Program, version 5.1. An analysis
of variance indicated no statistically significant difference between observed
and predicted values. A graphical comparison of kinetic values demonstrated that
modeled predictions were "fail safe" for generation time and exponential growth
rate at all temperatures. The model also was fail safe for lag-phase duration at
20 and 30 degrees C but not at 15 degrees C. Bias factors of 0.55, 0.82, and 1.82
for generation time, lag-phase duration, and exponential growth rate,
respectively, indicated that the model generally was fail safe and hence provided
a margin of safety in its growth predictions. Accuracy factors of 1.82, 1.60, and
1.82 for generation time, lag-phase duration, and exponential growth rate,
respectively, quantitatively demonstrated the degree of difference between
predicted and observed values. Although the Pathogen Modeling Program produced
reasonably accurate predictions of the growth of psychrotrophic B. cereus from
spores in boiled rice, the margin of safety provided by the model may be more
conservative than desired for some applications. It is recommended that if
microbial growth modeling is to be applied to any food safety or processing
situation, it is best to validate the model before use. Once experimental data
are gathered, graphical and quantitative methods of analysis can be useful tools
for evaluating specific trends in model prediction and identifying important
deviations between predicted and observed data.
PMID- 10678436
TI - Heavy metals in mussels (Mytilus galloprovincialis) from the lonian Sea, Italy.
AB - Concentrations of six heavy metals (Hg, Pb, Cd, Cr, Zn, and Sn) were determined
in mussels (Mytilus galloprovincialis) collected between June and September 1997
from 10 locations along a sound formed by two inlets (Mar Piccolo) near the Gulf
of Taranto (Ionian Sea, Italy). The average concentrations of the heavy metals
found in mussels samples were 0.15 mg/kg for Hg, 1.19 mg/kg for Pb, 0.64 mg/kg
for Cd, 0.31 mg/kg for Cr, 5.15 mg/kg for Zn, and 0.54 mg/kg for Sn. The
concentrations of heavy metals in mussels from the first inlet did not differ
greatly from those observed in mussels from the second inlet. The concentrations
of heavy metals in the mussels analyzed were below acceptable levels for human
consumption.
PMID- 10678437
TI - Application of the Bigelow (z-value) model and histamine detection to determine
the time and temperature required to eliminate Morganella morganii from seafood.
AB - In New Zealand, the product most frequently implicated in cases of scombroid or
histamine poisoning is the hot-smoked fish, kahawai (Arripis trutta). A properly
controlled heating step in the production of hot-smoked seafood could eliminate
bacteria able to convert the amino acid histidine to histamine. In this study, we
determined the core temperatures and times required during hot smoking of kahawai
to eliminate histamine-forming bacteria and to ensure a final product that will
not produce histamine if subsequent temperature abuse occurs. Morganella morganii
strains previously isolated from portions of hot-smoked kahawai with elevated
histamine levels were inoculated onto product to be tested. A variation of the
Bigelow or z-value model was used to generate a thermal death time graph, where
the production of histamine, in a heat-treated and subsequently temperature
abused sample, was scored as a positive value (growth) and the absence of
histamine was scored as a negative value (no growth). From a line fitted to the
data, calculated times for the elimination of histamine-forming bacteria at test
temperatures of 58, 59, 60, 61, and 62 degrees C were estimated to be 15.27,
8.81, 4.79, 2.68, and 1.46 min, respectively, giving a z value of 3.85 degrees C.
This approach to thermal death determination, based on the presence or absence of
a bacterial metabolite, proved to be an efficient way to determine the thermal
regime required to eliminate bacteria capable of converting histidine to
histamine on kahawai.
PMID- 10678438
TI - Immunochemical detection of molds: a review.
AB - Molds are widely distributed in nature and cause deterioration of foods and
feeds. Their mycotoxins can adversely affect human and animal health. Suitable
assays for molds, therefore, are required to implement control and regulatory
strategies and to develop appropriate feeding regimens for mold-infested feeds.
Many different types of mold assays have been used, most of which are not
reproducible or accurate. However, the immunoassays, particularly enzyme-linked
immunosorbent assays (ELISAs), can be especially useful. Among these, assays that
detect the water-soluble extracellular secretions of fungi, the exoantigens, are
generally able to detect fungi at the genus or species level, whereas the heat
stable polysaccharides tend to be specific for one or more genus of fungi.
Several species and genus (genera)-specific ELISAs have been developed using
monoclonal or polyclonal antibodies against exoantigens and heat-stable
polysaccharides from a wide range of fungi, including Aspergillus, Penicillium,
and Fusarium species. Other assays have been developed that nonspecifically
detect mold in food or feed, some using antibodies against a mixture of antigens
from different fungi. These assays are highly sensitive, are easy to perform, and
provide an index of the amount of mold present in the sample. Further refinement
of these assays should facilitate their widespread use by food and feed
processors, regulatory agencies, taxonomists, and research scientists.
PMID- 10678439
TI - Factors influencing clinical outcomes after revascularization in the asymptomatic
cardiac ischemia pilot (ACIP). ACIP Study Group.
AB - BACKGROUND AND AIM: The Asymptomatic Cardiac Ischemia Pilot is the first
randomized trial where revascularization involved choice of either coronary
bypass or angioplasty used in an early or a delayed symptom-driven approach. One
year outcomes were favorable (reduced recurrent ischemia and adverse outcomes)
for an early revascularization strategy (within 4 weeks), compared with an early
medical strategy when revascularization was delayed until symptom-driven. This
ancillary study examined variables influencing outcomes after these 2
revascularization approaches (early vs. delayed until symptom-driven). METHODS:
Participants were clinically stable coronary disease patients with stress-induced
and daily life ischemia who underwent revascularization. Characteristics
associated with clinical outcomes occurring within the year following
revascularization were examined using Cox regression analysis. RESULTS: A total
of 262 patients received revascularization; 170 in the early approach and 92 in
the delayed symptom-driven approach. Thirty-three patients had adverse outcomes
(death, nonfatal myocardial infarction, or repeat revascularization) during 1
year follow-up. The most important independent predictor of improved outcome
during the follow-up year was attempted revascularization of > or = 66% of
vessels with significant stenosis for the early (risk ratio [RR] 0.25, 95%
confidence interval [CI] 0.09-0.67) and the delayed (RR 0.21, CI 0.08-0.58)
approaches. Factors such as age, stress test results, and coronary angiographic
findings did not predict clinical outcome. CONCLUSIONS: Our findings are
important in the planning of a large trial with longer follow-up.
PMID- 10678440
TI - Self-expanding endovascular stent-graft implant for treatment of descending
aortic diseases.
AB - BACKGROUND: Aneurysms and dissections involving the descending thoracic aorta and
the distal portion of the aortic arch are difficult to resolve surgically. The
introduction of endovascular self-expanding stent-grafts has simplified the
operation. Given the complications associated with their peripheral placement, we
explored the feasibility of surgical insertion. METHODS: Thirteen patients
underwent surgical insertion of a stent-graft into the aortic arch via
longitudinal aortotomy. Six patients had aneurysms (ruptured in two, and seven
dissections (acute in two, ruptured in one). Five patients also underwent
associated procedures including aortic valve replacement (one), ascending aorta
replacement (two), arch replacement (one), and coronary artery bypass (one).
RESULTS: There was one intraoperative death due to ascending aortic dissection,
and two hospital deaths due to multiple complications. Of ten patients
discharged, one died 3 months postoperatively. The remaining survivors are well,
and imaging studies confirmed adequate correction of the aortic disease.
CONCLUSIONS: The use of this technique simplifies the operation and treatment of
particular cases of aortic disease. The observed morbidity and mortality are due
to factors independent of the technique.
PMID- 10678441
TI - Clinical results of endarterectomy of the right and left anterior descending
coronary arteries.
AB - In this study, we examined the clinical outcome of coronary endarterectomy. From
1990 to 1998, 4839 patients underwent surgical revascularization. Coronary artery
bypass graft surgery (CABG) was performed alone on 4516 patients, was combined
with right coronary artery endarterectomy (RCA-E) in 242 patients, and was
combined with left anterior descending coronary artery endarterectomy (LAD-E) in
81 patients. An analysis of preoperative variables revealed a higher proportion
of males (90.7% vs 80.2%, p < 0.001), of patients with low ejection fraction (<
35%; 4.6% vs 1.7%, p < 0.001), and of three-vessel disease (47.9% vs 36%, p <
0.001) in the RCA-E versus the CABG patients. There was a higher proportion of
unstable angina (51.9% vs 40.3%, p = 0.04) in the LAD-E patients. The 30-day
mortality rate for CABG was 2% versus 2.5% for RCA-E and 3.7% for LAD-E (p = NS).
Perioperative myocardial infarction (MI) rate for CABG was 3.4% versus 7.0% for
RCA-E (p < 0.001) and 4.9% for LAD-E patients (p = NS). Postoperative low cardiac
output syndrome was recorded in 11.5% of CABG, 18.6% of RCA-E (p = 0.01), and
11.1% of LAD-E (p = NS) patients. Predictors of postoperative bad outcome (death,
MI, low cardiac output, cerebrovascular accident) were preoperative intra-aortic
balloon pump, repeat operation, ejection fraction of < 35%, renal insufficiency,
female gender, RCA-E, and age over 70. Protective factors included the use of
internal mammary artery, multiple arterial grafts, and warm cardioplegia.
Actuarial analysis at 6, 12, and 24 months showed late mortality rates of 0.8%,
1.3%, and 2.1% for CABG; 1.2%, 3.7%, and 3.7% for RCA-E; and 2.9%, 2.9%, and 2.9%
for LAD-E, respectively. Late MI occurrence was 0.4%, 0.4%, and 0.7% for CABG;
1.5%, 1.5%, and 2.7% for RCA-E; and 0% for LAD-E, respectively. Multivariate
analysis found renal insufficiency, ejection fraction of < 35%, repeat operation,
female gender, New York Heart Association functional class IV, and diabetes to be
predictors for late adverse events (recurrence of angina, MI, and cardiac death),
and RCA-E was found to be a predictor of late MI. We conclude that the use of
coronary endarterectomy to achieve complete revascularization in patients with
diffuse distal coronary artery disease is a reasonable option, associated with a
minimal addition in complication rates.
PMID- 10678442
TI - Use of extrafascially harvested radial artery for coronary artery
revascularization: technical considerations.
AB - BACKGROUND: The use of the radial artery for coronary artery revascularization
was abandoned due to its tendency for spasm; the revival was attributed to
improved harvesting technique as well as the use of calcium channel blockers.
METHODS: Between February 1996 and June 1997, the radial artery graft was used in
77 of 89 consecutive patients undergoing coronary artery bypass graft surgery.
Only the patients with positive Allen's test or forearm deformity were denied the
use of the radial artery. We used an extrafascial, no-touch technique using low
strength electrocautery for harvesting the radial artery. Calcium channel
blockers were not used in any of these patients. RESULTS: There were no early
deaths. No patient sustained perioperative myocardial infarction or required
intra-aortic balloon pump. Only one patient required inotropic agents. Three
noncardiac late deaths occurred during the follow-up of 6 to 24 months. No early
or late ischemic or functional forearm disability was reported in any of the
patients. CONCLUSIONS: The radial artery is easy to harvest and safe to use
routinely. When harvested extrafascially, diltiazem infusion may not be
necessary. Maximal arterial-global revascularization using the left internal
thoracic artery-to-left anterior descending coronary artery and radial artery-to
circumflex artery system may improve the early and long-term results.
PMID- 10678443
TI - Excision of coronary artery fistula and coronary artery reconstruction without
cardiopulmonary bypass.
AB - In three patients, coronary artery fistulas originating from a conal branch of
the mid-segment of the left anterior descending coronary artery (n = 2) and right
coronary artery (n = 1) with drainage into the right atrium (n = 2) and right
ventricle (n = 1) were successfully closed without the use of cardiopulmonary
bypass. The use of a coronary artery stabilizer greatly facilitated the operation
by immobilization of the fistula, its supplying coronary artery, and the regional
myocardium. In selected patients, this technique allows secure closure of the
fistula and meticulous reconstruction of the coronary artery without the use of
cardiopulmonary bypass.
PMID- 10678444
TI - New horizons on the surgical treatment of dilated cardiomyopathy.
PMID- 10678445
TI - Left ventricular volume reduction: new dawn or false horizon? Basic science and
clinical doubts.
AB - Left ventricular volume reduction surgery (LVVR) for end-stage dilated
cardiomyopathy is a surgical option used selectively but with unclear long-term
results. Increasing numbers of reports are appearing in the literature. These
should be pooled into an international registry through collaborative efforts
that allow for more effective analysis. Furthermore, high priority must be given
to identify subgroups of patients who will potentially gain most benefit from
LVVR. Basic science may add invaluable data and in this article we describe how
intraoperative myocardial biopsies from patients with idiopathic dilated
cardiomyopathy were utilized to isolate myocytes in an effort to determine
differential physiological characteristics at the cellular level. The result
showed various degrees of contractile anomalies in response to electrical
stimulation associated with defective calcium handling as reflected by
measurements of calcium transients. It is hoped that this approach may be
extended to preoperative catheter biopsy to gain information that will facilitate
patient selection to avoid unnecessary surgical failures.
PMID- 10678446
TI - Endoventricular patch reconstruction in large ischemic wall-motion abnormalities.
AB - Endoventricular patch plasty (EVPP) has been used since 1984 to rebuild the left
ventricle. The global experience of our group includes more than 835 cases. Large
wall-motion abnormalities were detected by the center line method when > 60% of
the circumference of the left ventricle was asynergic. In this series, 269
patients had an ejection fraction < 30%. Surgery for repair of large wall-motion
abnormalities was conducted on the arrested heart with insertion within the left
ventricle of a patch rebuilding the contractile area while leaving a residual
volume between 50 and 70 cc/m2 of body surface. The global results of the
technique of EVPP are analyzed on the last 700 operated patients. Three series of
patients with large wall-motion abnormalities were examined. We conclude that
this technique is appropriate in advanced stages of ischemic disease as an
alternative to cardiac transplant. At an operative risk of approximately 12%,
improvement is obtained in 80% of cases.
PMID- 10678447
TI - Commonality of ischemic and dilated cardiomyopathy: laplace and ventricular
restoration.
PMID- 10678448
TI - Left ventricular volume reduction for end-stage heart disease.
AB - Partial left ventriculectomy (PLV) was recently introduced for end-stage dilated
cardiomyopathy to improve ventricular function. Since November 1996 we have
performed PLV in 14 patients; preoperatively 4 patients had idiopathic dilated
cardiomyopathy and 10 had ischemic dilated cardiomyopathy. 57.1% of patients were
in New York Heart Association functional Class IV. The mitral valve was replaced
in 11 patients. Postoperative echocardiography showed a reduction of left end
diastolic diameter (55.4 +/- 5.4 mm) and an increase in forward ejection (cardiac
index from 2.19 +/- 0.571 min/m2 to 2.67 +/- 0.931/min/m2). The 30-day mortality
was 28.6% and 20-month survival was 57.2%. Only one patient was not in NYHA
functional class due to postoperative progressive mitral incompetence. Prognostic
factors should be identified to avoid early failure. However, even if the
mortality rate for PLV high, this operation is a valid choice for the treatment
of end-stage dilated cardiomyopathy.
PMID- 10678449
TI - Dilated cardiomyopathy: changing pathophysiological concepts and mechanisms of
dysfunction.
AB - Experimental observations made over the past two decades have led to a profound
shift in the conceptual paradigms about the syndrome of heart failure and dilated
cardiomyopathy. As a consequence, heart failure is currently considered a complex
disease and is not merely characterized by hemodynamic disturbances. It is now
believed that the syndrome is governed and impelled by neurohormonal imbalances
and intracardiac paracrine processes. The latter processes are mediated by
activated cardiac endothelial cells and cytokines, creating a state of cardiac
maladaption and leading to disease progression. Therapeutic interventions such as
operative left ventricular volume reduction or mitral valve reconstruction should
therefore no longer be solely interpreted in terms of hemodynamics (i.e.,
symptomatic improvements). Effects on neurohormonal, endothelial, and cytokine
activities should be taken equally into account.
PMID- 10678450
TI - Low vision and blindness.
PMID- 10678451
TI - Outcome assessment of the rehabilitation of the visually impaired.
AB - The purposes of this project are to establish the psychometric properties of
instruments used to gather data relevant to blind rehabilitation outcomes, to
refine the scaling and scoring protocols for the instruments, and to revise and
refine the outcome instruments. This 3-year project will gather outcome and
demographic data from an estimated 1,200 visually impaired veterans per year,
along with a companion sample an estimated 1,200 visually impaired nonveterans
per year, using the following core measures: Blind Rehabilitation Service Follow
up Outcome Survey (BRSFOutSur) measuring functional performance, Blind
Rehabilitation Service Data Base (BRSDBase) recording subject characteristics,
and Blind Rehabilitation Service Satisfaction Survey (BRSSatSur) measuring
satisfaction with rehabilitation. As of July 1999, data from 2,624 veterans have
been collected for the demographic instrument, from 1,630 veterans for the
functional outcomes instrument, and from 1,655 veterans for the satisfaction
instrument. Data collection and analysis are currently ongoing. These findings
and the further development of outcome instruments in this area will contribute
to greater efficiency and effectiveness of the delivery of blind rehabilitation
services by the Department of Veterans Affairs.
PMID- 10678452
TI - Characteristics of AMD patients with low vision receiving visual rehabilitation.
AB - The purpose of this retrospective study done on 255 AMD patients evaluated at a
low vision rehabilitation service was: 1) to describe the visual function
characteristics (VFCs) of AMD patients presenting to visual rehabilitation, 2) to
document changes in these VFCs between initial and follow-up rehabilitation
visits, and 3) to investigate the relationship of the VFCs found at
rehabilitation intake to the length of time between initial diagnosis and initial
rehabilitation visit. Standard clinical testing (visual acuity and contrast
sensitivity) as well as Scanning Laser Ophthalmoscope (SLO) visual function
testing were performed to determine visual function including: 1) macular
perimetry for scotoma boundary mapping and 2) PRL (preferred retinal locus)
location and abilities in fixation, saccadic, and pursuit eye movements. The
difference between the first and second visit VFCs were compared to the length of
time between visits for 44 of the 255 patients returning for a second visit 0.5
to 4.5 years later. Finally, the initial date of AMD diagnosis was found for 51
of the 255 patients to analyze VFCs as a function of the time duration between
diagnosis and the intake to the rehabilitation. Most VFCs had a wide range of
results at initial intake to rehabilitation, while all patients had significant
visual impairment by 24 months after initial diagnosis. The majority of low
vision patients with AMD have bilateral central scotomas with the corresponding
visual function and ADL problems that can often be overcome with visual
rehabilitation.
PMID- 10678453
TI - Visual factors and mobility in persons with age-related macular degeneration.
AB - The objectives of this study were to determine the effects of reducing light
level on mobility performance in persons with age-related macular degeneration
(ARMD) and how performance relates to measures of visual sensory and perceptual
function. ARMD results in the loss of central, high-acuity vision and is the
leading cause of vision loss in veterans participating in the blind
rehabilitation programs of the Department of Veterans Affairs. In 41 subjects
with ARMD acuity, peak letter contrast sensitivity, visual field extent, glare
disability, color confusion, spatio-temporal contrast sensitivity, motion
sensitivity, scanning ability, and figure-ground discrimination were measured to
determine their ability to predict mobility performance. Mobility performance was
assessed under photopic (high illumination) and mesopic (low illumination)
lighting conditions on a laboratory obstacle course and two real-world courses,
an indoor hallway and an outdoor residential route. Reducing illumination
resulted in significant increases in the time to complete each course and the
number of mobility incidents (errors) that occurred. Two measures of overall
performance, total time and total mobility incidents, were calculated for each
course by summing time and incidents over the two illumination levels.
Combinations of vision variables were able to account for 30 to 60% of the
variance in the measures of overall performance. Log contrast sensitivity
measured with the Pelli-Robson chart test and visual field extent were the most
important predictors of performance. Other variables making significant
contributions to prediction in multi-predictor models included: scanning ability,
glare sensitivity, color confusion, and peak contrast sensitivity to drifting
gratings.
PMID- 10678454
TI - Auditory perception of walls via spectral variations in the ambient sound field.
AB - Individuals with visual disabilities often use their hearing in order to maintain
a line of travel parallel to walls, such as when walking down a hallway or along
the side of a building. Previous studies established that this ability depends on
the sense of hearing, but the specific acoustic information has not been
investigated. The present paper describes a model of how sound pressure builds up
within a meter or so in front of a wall, particularly in the low frequency end of
the sound spectrum. This buildup of sound pressure is based on ambient or
"background" sound, not self-produced sound such as footsteps. The model leads to
a prediction that walls are detected by means of a spectral shift toward low
frequencies. This prediction was tested in three experiments, in which sighted
adults listened for such spectral shifts. In each experiment, a threshold value
was obtained corresponding to the farthest simulated distance from a wall that
could be detected. Threshold values were in good agreement with previous
observations of the distance at which pedestrians can utilize acoustic
information from walls. There was no evidence that simulated listener motion
enhanced perception of walls. The model underlying these experiments implies that
the term echolocation carries inappropriate connotations about the auditory
processes that are involved in walking along walls. It is suggested that a more
apt description is that pedestrians listen for spatial variations in the
structure of the ambient sound field.
PMID- 10678455
TI - A biomechanical evaluation of visually impaired persons' gait and long-cane
mechanics.
AB - This study was designed to compare selected kinematic components of gait and long
cane mechanics between groups of visually impaired travelers. Twenty subjects
were placed in Traditional or Modified technique groups according to their long
cane traveling technique. Subjects were measured during the following conditions;
1) normal walking (NW), 2) walking while anticipating a simulated drop-off (AD),
3) walking while responding to an audible task (ST) and, 4) walking while
anticipating a simulated drop-off and responding to an audible task (STAD). Data
were analyzed using a repeated measures analysis of variance (ANOVA) and
Pearson's r correlation coefficient. Analyses revealed no differences between
groups of travelers. However, significant differences were noted between trials
for components of gait velocity, stride length, and hip flexion velocity. These
findings may indicate a potentially dangerous alteration in the normal gait cycle
of visually impaired travelers when faced with additional attention-demanding
tasks while walking.
PMID- 10678456
TI - The use of the sonic pathfinder as a secondary mobility aid for travel in
business environments: a single-subject design.
AB - Two studies were conducted using a single subject research design in different
business environments to evaluate the efficacy of the Sonic Pathfinder for
increasing efficiency in travel with an experienced and accomplished blind
traveller. The Sonic Pathfinder is one of eight or nine commercially available
electronic travel aids (ETAs) designed for use by blind or visually impaired
persons. The use of ETAs are thought to result in more rapid travel and a greater
ability to detect and avoid obstacles in one's path. Elapsed time for travel and
the number of unintentional contacts made while travelling were used as the
dependent variables in both studies. No marked effect was observed for either
variable in either study. An additional traveller who was slower and more tenuous
in his movements was recruited to participate in the second study to investigate
the possibility that a floor effect may have masked the results of the use of the
ETA with the first subject. However, no marked effects were observed with this
subject either. Yet, both subjects stated that the use of the aid increased their
distance for environmental preview over and above that provided by the long cane
alone, while providing them with the opportunity to judge the distance of objects
approached beyond cane length. Discussion centers on the need to identify other
means to evaluate the utility of this aid in light of the positive statements
made by the participants of these studies.
PMID- 10678457
TI - Remote infrared signage evaluation for transit stations and intersections.
AB - Opportunities for education and employment depend upon effective and independent
travel. For mainstream society, this is accomplished to a large extent by printed
signs. People who are print disabled, visually impaired, or totally blind are at
a disadvantage because they do not have access to signage. Remote infrared
signage, such as the Talking Signs (TS) system, provides a solution to this need
by labeling the environment for distant viewing. The system uses a transmitting
"sign" and a hand-held receiver to tell people about their surroundings. In a
seamless infrared signage environment, a visually impaired traveler could: walk
safely across an intersection to an ATM or fare machine, from fare machine to bus
stop, from bus stop to bus; from bus to building, from building to elevator, from
elevator to office, from office to restroom, and so forth. This paper focuses on
two problems that are among the most challenging and dangerous faced by blind
travelers: negotiating complex transit stations and controlled intersections. We
report on human factors studies of TS in these critical tasks, examining such
issues as how much training is needed to use the system, its impact on
performance and safety, benefits for different population subgroups and user
opinions of its value. Results indicate that blind people can quickly and easily
learn to use remote infrared signage effectively, and that its use improves
travel safety, efficiency, and independence.
PMID- 10678458
TI - Relative locations of macular scotomas near the PRL: effect on low vision
reading.
AB - Patients referred for low vision rehabilitation had Minnesota Reading Acuity
(MNRead), visual acuity (VA), and scanning laser ophthalmoscope (SLO) macular
function testing performed in their initial evaluation to determine whether dense
macular scotomas near the preferred retinal locus (PRL) have a significant effect
on the characteristics of reading based on rate. The 99 subjects had macular
scotoma characteristics relative to the fovea/PRL of: 22% only to the right; 15%
only to the left; 26% both the right and left; 19% above or below; 17% had no
dense scotomas. Reading performance (maximum reading speed, critical print size,
and reading acuity) was significantly different between the non-scotoma group and
all of the scotoma groups. There was no statistically significant difference in
the characteristics of reading based on rate between the four scotoma groups:
within each there was a wide variation in the characteristics of reading based on
rate not fully explained by either VA or scotoma location. The position of the
scotoma relative to the PRL was not a statistically significant factor in
determining reading rate as found in studies on normally sighted people with
artificial scotomas. Other factors (e.g., maybe PRL ability in fixation and
saccadic eye movements and/or cognitive ability) are significantly involved in
determining reading rate characteristics in people with macular scotomas.
PMID- 10678459
TI - Impact of digital miniaturization and networked topologies on access to next
generation telecommunication by people with visual disabilities.
AB - In the past, telecommunication technologies did not present any particular
problem for persons with visual disabilities. The telephones themselves were
auditory in nature and could be operated by touch. As telecommunication begins to
incorporate video and as telecommunication devices become more complex (including
the incorporation of visual displays), new barriers are appearing. Fortunately,
advancing technologies are also providing new opportunities for access. The
rapidly shrinking size and cost of electronics is allowing us to build
intelligence and flexibility into telecommunication products. Advances will soon
allow voice to be incorporated into most devices. In addition, clever use of
networks and network-based services will allow access features to be built
directly into the network, providing access to key visual information. As a
result, future telecommunication systems can be more accessible than technologies
of the past-if they are implemented correctly.
PMID- 10678460
TI - Subretinal implantation of semiconductor-based photodiodes: progress and
challenges.
AB - Retinal diseases that result in photoreceptor degeneration may spare the inner
retinal layers. This review concerns a prosthetic approach to restoring visual
function through the use of a semiconductor-based microphotodiode array implant,
designed to be placed under the neural retina in the subretinal space. The
fundamental idea is that current generated by the device in response to light
stimulation will alter the membrane potential of overlying neurons and thereby
activate the visual system. Initial acute studies indicated that the implant will
function in the subretinal space in the absence of an external power supply. More
recent and ongoing studies involve chronic subretinal implantations in normal
animals. Post-operative studies have demonstrated that implant function will
persist for many months. These chronic studies have also assessed the
biocompatibility of the implant. Photoreceptors are lost directly overlying the
implant, due to the blockade of choroidal circulation to the outer retina by the
solid disk device. In comparison, the inner retina maintains its characteristic
lamellar structure. Away from the implant site, the retina retains normal anatomy
and function. Future studies are needed to determine whether the implant can
establish a functional connection to the inner retina and to determine the
quality of this connection.
PMID- 10678461
TI - A new method for continuous, long-term polysomnographic recording of neonatal
rats.
AB - STUDY OBJECTIVES: Many findings suggest that in altricial mammals neonatal REM
sleep has developmental functions. However, investigations of these developmental
functions has been hampered by technical limitations of the conventional
polysomnographic (PSG) recording technique. One limitation is that continuous (24
hour/day), long-term (weeks) PSG recordings have not been achieved. A second
limitation is that the metal screw electrodes and head plugs cemented to the
skull cannot be removed to allow the neonate to mature into adulthood. As a
result of these limitations, the relationship between neonatal sleep/wake
variables and adult variables has not been studied. Also the effects of
polysomnographically controlled neonatal REM sleep deprivation on adult variables
have not been studied. The present work describes a new technique called the soft
head plug (SH) method for continuous, long-term PSG recording. DESIGN: In the new
technique, electrodes are thin, strong, Teflon wires that are led by a suturing
needle through the soft skull to the epidural space, then with a U-turn exited
from the skull and tied to the entry wire. Thus, in contrast to the conventional
technique, the soft head plug technique does not use screws as electrodes and
does not cement a hard, relatively large electrode plug to the skull, removal of
which is fatal or very traumatic. The SH recording electrodes can be removed
without damage to neonates. SETTING: NA. PATIENTS: NA. INTERVENTIONS: NA.
RESULTS: In the present study sleep/wake results with the soft head plug
technique were reliable (replicated) and, compared with results of the
conventional method, valid. CONCLUSIONS: The results indicate that the soft head
plug technique can be used to study relationships between neonatal sleep/wake
variables and adult variables.
PMID- 10678462
TI - The impact of split-night polysomnography for diagnosis and positive pressure
therapy titration on treatment acceptance and adherence in sleep apnea/hypopnea.
AB - STUDY OBJECTIVES: The time and resource intensive nature of the traditional two
night paradigm for diagnosing and titrating positive pressure therapy for
Obstructive Sleep Apnea/Hypopnea (OSA/H) contributes to patient care cost and
limitation of service availability. Although split night polysomography (PSG(SN))
algorithms can establish a diagnosis of OSA/H and establish a positive pressure
prescription for many patients, there has been only limited evidence that this
strategy does not impair acceptance and adherence to treatment. The objective of
this study was to test the null hypothesis that PSG(SN) does not adversely impact
acceptance and adherence to positive pressure therapy for OSA/H compared with a
standard two-night PSG strategy (PSG(TN)). DESIGN: Retrospective case-controlled
study. SETTING: University-based sleep disorders program PATIENTS: Both PSG(SN)
and PSG(TN) (control) patients were selected on the basis of having an initial
medical/sleep evaluation by a full-time physician member of the University of
Pittsburgh Sleep Disorders Program, must not have had prior diagnostic PSG or
treatment for sleep-disordered breathing, and must have been followed by the
Sleep Program team. Selection of PSG(SN) patients required the ability to be
matched with a control patient. Both groups underwent evaluation during the same
time period. Of 146 patients who underwent PSG(SN) between October 1995 and
September 1997, 51 had their initial evaluation and subsequent follow-up by
physician-staff members of our Program. Of these, 15 were excluded from analysis
because of a previous diagnostic PSG's or prior OSA/H therapy. Also, matches were
unavailable for 5 patients. Seven patients refusal to use positive pressure at
home and were not available for assessment of adherence, but were included in
analysis of therapeutic acceptance. Thus, analysis of the impact of PSG(SN) on
adherence to positive pressure therapy was based on a data set of 24 patients in
whom a PSG(SN) was performed and 24 patients who had PSG(TN). The two groups were
matched for age, Apnea+Hypopnea Index (AHI) and gender. MEASUREMENT AND RESULTS:
There were no significant differences between the PSG(SN) and PSG(TN) groups with
respect to age, body mass index (BMI), Desaturation Event Frequency (DEF),
Arousal Index (ArI) or the Epworth Sleepiness Score (ESS). The nadir of
oxyhemoglobin saturation (SpO2) during sleep was lower in the PSG(TN) than
PSG(SN) group (69.3+/-15 vs. 79.8+/-9, mean+/-SD, p=0.012). During positive
pressure titration, the time spent at the final pressure which was prescribed for
the patients were comparable in both groups (123.4+/-64 vs. 161+/-96 minutes,
PSG(SN) and PSG(TN), respectively, p=0.17). Adherence to therapy was objectively
assessed by the average daily run-time of the positive pressure device at the
first meter-read following initiation of treatment (55.1+/-44 vs. 40.8+/-16 days
following home set-up, PSG(SN) and PSG(TN), respectively, p=0.14). Depending
whether or not patients with previous exposure to positive pressure therapy were
included in the analysis, 84-86% of patients undergoing PSG(SN) accepted therapy.
There was no difference between the groups with respect to adherence (5.1+/-4 vs.
4.6+/-3 hours, PSG(SN) and PSG(TN), respectively, p=0.64). CONCLUSIONS: In a
population of predominantly moderate-to-severe OSA/H patients, PSG(SN) strategy
does not adversely impact on adherence to positive pressure therapy over the
first six weeks of treatment. Acceptance of therapy is comparable to that
reported in the literature following PSG(TN).
PMID- 10678463
TI - Prevalence and correlates of self-reported sleep problems among Chinese
adolescents.
AB - STUDY OBJECTIVES: This study examined the prevalence and correlates of sleep
problems in Chinese adolescents. DESIGN AND SETTING: An epidemiological
questionnaire survey was carried out in five high schools in Shandong Province of
Mainland China. PARTICIPANTS: A total of 1365 adolescents between the ages of 12
and 18 years comprising 823 boys and 542 girls. MEASUREMENTS AND INTERVENTIONS:
The participants completed a self-administered questionnaire regarding sleep
duration, sleep problems, stressful life events, lifestyles, and personal and
family characteristics. RESULTS: Mean sleep duration at night was 7.64 hours (SD
= 0.86) and decreased with increasing age. Of the sample, 16.9% (95% CI = 13.2
20.5%) reported insomnia symptoms including difficulty initiating sleep (10.8%),
difficulty maintaining sleep (6.3%), and early morning awakening (2.1%).
Nightmares were reported more frequently by girls (chi2=20.09, p<0.001). Only
2.3% of the sample had ever taken hypnotic medication during the past month.
Almost 22% of the subjects went to bed later than 12:00 PM at least once a week.
Multiple logistic regression analysis showed that greater age, being at senior
high school, doing no habitual physical exercise, poor physical health, self
selection of diet, longer distance from home to school, and life stress
experienced during the past 12 months were significantly associated with an
increased risk of insomnia. CONCLUSIONS: Self-reported sleep problems in Chinese
adolescents are common and associated with multiple factors. These findings
suggest the need for comprehensive programs to prevent sleep problems in
adolescents.
PMID- 10678464
TI - An epidemiological study of insomnia among the Japanese general population.
AB - The study examined the prevalence and correlates of insomnia in a representative
sample (n=3030) from the general population of Japan. Using a structured
questionnaire, we found that the overall prevalence of insomnia during the
preceding month was 21.4%, including difficulty initiating sleep (DIS: 8.3%),
difficulty maintaining sleep (DMS: 15.0%), and early morning awakening (EMA:
8.0%). Multiple logistic regression analysis showed that older age, being
unemployed, lack of habitual exercise, poor perceived health, psychological
stress, and being unable to cope with stress were associated with an increased
prevalence of insomnia. These findings indicate that the prevalence of insomnia
in the general population of Japan is comparable to that reported in Western
countries, and that insomnia is associated with multiple psychosocial factors.
PMID- 10678465
TI - Sleepiness at work among commercial truck drivers.
AB - Two separate groups consisting of both long-haul (N=184) and short-haul (N=133)
truck drivers were surveyed to examine the frequency of driver sleepiness-related
problems at work during the previous three months and to assess the incidence of
sleep apnea syndrome symptoms. We also aimed to identify factors likely to
predict self-reported difficulties in staying alert in work driving, dozing off
(sometimes referred to as microsleeps) at the wheel and near misses. The
responses suggest that for approximately 13% of the long-haul drivers the mean
driving time per shift exceeded the EEC regulation. About 40% of the long-haul
drivers and 21% of the short-haul drivers reported having problems in staying
alert on at least 20% of their drives. Over 20% of the long-haul drivers also
reported having dozed off at least twice while driving. Near misses due to dozing
off had occurred in 17% of these drivers. Factors indicating sleep apnea syndrome
occurred in only about 4% of the long-haul drivers and in only two short-haul
drivers. Work and individual related factors as well as factors indicating sleep
apnea syndrome contributed only slightly to predicting driver sleepiness-related
problems. This suggests that driver sleepiness-related problems tend to be shared
by many of the professional drivers, rather than being a "specific" and permanent
problem for a smaller portion of drivers. However, difficulties in sleep
patterns, such as having difficulty falling asleep, were infrequent.
PMID- 10678466
TI - Accuracy of oximetry with thermistor (OxiFlow) for diagnosis of obstructive sleep
apnea and hypopnea.
AB - OBJECTIVES: To evaluate the diagnostic accuracy for obstructive sleep apnea and
hypopnea (OSAH) of the OxiFlow (OF) device which combines oximetry with recording
of thermistor airflow. DESIGN & SETTING: Patients scheduled for overnight
diagnostic polysomnography (PSG) were studied with OF either simultaneously
during laboratory PSG (L-OF, n=86), at home on a separate night (H-OF, n=66), or
both (n=55). PATIENTS: 97 patients with suspected OSAH, of whom 40 had OSAH
defined as an apnea-hypopnea index (AHI) of more than 15 events per hour of sleep
on PSG. INTERVENTIONS: NA. MEASUREMENTS & RESULTS: The automated respiratory
disturbance index (RDI) generated by the OF software considerably underestimated
the AHI by PSG for both L-OF and H-OF. Altering the parameters for hypopnea
identification by the software did not improve this. Visual inspection of the
computerized OF tracings added considerable diagnostic information, but a manual
count of RDI during visual review overestimated AHI. For the identification of
cases vs. non-cases of OSAH, receiver operating characteristic area-under-the
curve statistics ranged from 0.77-0.90 for L-OF and from 0.71-0.77 for H-OF.
Combining automated analysis with subsequent visual inspection of OF tracings
yielded an overall sensitivity of 86% and specificity of 74% for the diagnosis of
OSAH during H-OF recordings. Analysis of potential technician time saved
indicated a benefit from the use of OF. CONCLUSIONS: OF has diagnostic utility
for the identification of OSAH. However, because of hardware and software
limitations, it is unclear whether this device is superior to oximetry alone.
PMID- 10678467
TI - Sleep latency and duration estimates among sleep disorder patients: variability
as a function of sleep disorder diagnosis, sleep history, and psychological
characteristics.
AB - STUDY OBJECTIVES: Insomnia patients often report greater sleep disturbance than
found via polysomnography; yet the specific patient factors related to such sleep
time misperceptions are poorly understood. We sought to characterize the extent
to which a diverse group of patients complaining of insomnia (n=104) misperceive
overnight total sleep time and sleep latency, and to identify patient factors
associated with these variations. DESIGN: Cross-sectional. SETTING: University
based sleep disorders center. PATIENTS: Sleep disorder groups consisted of
patients with psychophysiological insomnia (n=19), sleep state misperception
(n=8), insomnia with depressive disorder (n=11), insomnia secondary to Axis I
psychiatric disorder other than depression (n=21), periodic limb movement
disorder (n=24), and obstructive sleep apnea (n=21). MEASUREMENT AND RESULTS:
Patients completed a sleep history questionnaire and the MMPI, underwent
overnight diagnostic polysomnographic assessment, and then estimated their total
sleep time and sleep latency the subsequent morning. On average, patients
overestimated sleep latency, but were equally likely to underestimate vs.
overestimate total sleep time. Sleep time misperception was associated with
longer periods of wakefulness following sleep onset, greater self-perceived sleep
impairment, as well as several psychological dimensions. CONCLUSIONS: Patient
factors, including sleep quality, perceptions of habitual sleep time, and current
psychopathology, potentially influence sleep time estimation. Whereas
psychological factors may lead to exaggeration of sleep disturbance among some
patients, sleep quality itself may also influence the congruence between
subjective and objective indices of sleep.
PMID- 10678468
TI - Sleep deprivation and phasic activity of REM sleep: independence of middle-ear
muscle activity from rapid eye movements.
AB - In the recovery nights after total and partial sleep deprivation there is a
reduction of rapid eye movements during REM sleep as compared to baseline nights;
recent evidence provided by a selective SWS deprivation study also shows that the
highest percentage of variance of this reduction is explained by SWS rebound. The
present study assesses whether the reduction of rapid eye movements (REMs) during
the recovery night after total sleep deprivation is paralleled by a decrease of
middle-ear muscle activity (MEMA), another phasic muscle activity of REM sleep.
Standard polysomnography, MEMA and REMs of nine subjects were recorded for three
nights (one adaptation, one baseline, one recovery); baseline and recovery night
were separated by a period of 40 hours of continuous wake. Results show that, in
the recovery night, sleep deprivation was effective in determining an increase of
SWS amount and of the sleep efficiency index, and a decrease of stage 1, stage 2,
intra-sleep wake, and NREM latencies, without affecting REM duration and latency.
However, MEMA frequency during REM sleep did not diminish during these nights as
compared to baseline ones, while there was a clear effect of REM frequency
reduction. Results indicate an independence of phasic events of REM sleep,
suggesting that the inverse relation between recovery sleep after sleep
deprivation and REM frequency is not paralleled by a concomitant variation in
MEMA frequency.
PMID- 10678469
TI - Daily social and physical activity increases slow-wave sleep and daytime
neuropsychological performance in the elderly.
AB - Decreased levels of physical and social activity associated with aging can be
particularly pronounced in residents of assisted living facilities. Reduced
exposure to important behavioral and time-giving cues may contribute to the age
related changes in circadian rhythmicity and sleep. The present study was
conducted to test the hypothesis that an enforced schedule of structured social
and physical activity (0:900 to 10:30 and 19:00 to 20:30 daily for two weeks) can
have beneficial effects on circadian rhythmicity, nocturnal sleep, daytime
functioning, mood, and vigor. The subjects were 14 elderly residents of continued
care retirement facilities while a similar group of 9 elderly residents served as
controls. The group exposed to structured activities had increased amounts of
slow-wave sleep and demonstrated improvement in memory-oriented tasks following
the intervention. Conversely, no significant changes were noted in the amplitude
and phase of the body temperature rhythm or in subjective measures of vigor and
mood. These results indicate that short-term exposure to structured social
intervention and light physical activity can significantly improve memory
performance and enhance slow-wave sleep in older adults without alterations to
the circadian phase or amplitude of body temperature. This is the first report to
demonstrate that low intensity activity in an elderly population can increase
deep sleep and improve memory functioning. The high degree of interest in these
activities paired with the simple nature of the tasks makes this a potentially
practical intervention which can be adapted for both community dwelling and
assisted-living elders.
PMID- 10678471
TI - Recent literature in sleep research.
PMID- 10678470
TI - The roles of vertex sharp waves and K-complexes in the generation of N300 in
auditory and respiratory-related evoked potentials during early stage 2 NREM
sleep.
AB - STUDY OBJECTIVES: To determine the scalp topography of the N300 response to
stimuli of different modalities and to investigate the relationship of the N300
component to K-complexes and vertex sharp waves seen in the un-averaged EEG.
DESIGN: Two experiments were conducted one using auditory; the other using
respiratory occlusion stimuli presented during stage 2 sleep. Trials were
classified on the basis of whether they produced a K-complex, a vertex sharp
wave, or some other response. Auditory stimuli were presented in the form of an
oddball paradigm, and averaged separately depending on whether they were
"frequent" or "rare". In both experiments, responses were averaged separately
based on the appearance of K-complexes, vertex sharps waves, or some "other"
response to the stimuli. SETTING: Data were collected in the Melbourne University
Sleep Laboratory. PARTICIPANTS: Young healthy male adults, eight in experiment 1
and six in experiment 2. INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: Data were
collected from 29 scalp sites. In all cases, N300 amplitude was maximal in the
vertex sharp wave averages, despite being clearly present in the averages of K
complexes and "other" responses. The vertex maximal scalp topography of the N300
did not differ across response conditions or as a function of stimulus modality.
This is consistent with the N300 being produced by the same intracranial
generators in all cases. There were no effects of stimulus or response type on
N300 latency. CONCLUSIONS: N300 should be viewed as a multi-modal component with
a different underlying generator mechanism than that of the K-complex.
PMID- 10678472
TI - The emerging AIDS crisis in Russia: review of enabling factors and prevention
needs.
AB - Eastern Europe is experiencing increased rates of HIV/AIDS, and the Russian
Federation is among the countries with the most alarming case rate increases.
Behavioural and biological studies demonstrate that the transmission of HIV in
Russia is occurring as a result of injection drug use, homosexual, and
heterosexual risk behaviours. Factors that promote risk and therefore enable HIV
transmission in Russia parallel those found in other countries, including
epidemics of other sexually transmitted infections, economic instability,
poverty, and social factors such as gender roles. Research is urgently needed to
better understand and forecast the HIV epidemic in Russia, as well as to develop
effective interventions to prevent a Russian AIDS crisis.
PMID- 10678473
TI - Mycoplasma species in rapid and slow HIV progressors.
AB - We determined the relationship between the presence of Mycoplasma fermentans and
Mycoplasma penetrans and the rate of progression of HIV-associated disease in a
nested case-control study based on a cohort of 159 HIV-infected patients with
different rates of disease progression. Study participants were divided into 3
progression groups: non-progressors who had been HIV-1 seropositive for at least
9 years and had remained asymptomatic with a CD4 cell count of > 500/mm3; slow
progressors who had been HIV-1 seropositive for at least 9 years and whose CD4
cell count had fallen below 500 cells, and who had developed symptomatic disease
or AIDS; and rapid progressors who had developed AIDS within 5 years of HIV
infection. Peripheral blood mononuclear cells (PBMCs) were collected at
enrollment and examined by mycoplasma polymerase chain reaction (PCR) assays.
Three (7%) of 46 non-progressors, 3 (3%) of 86 slow progressors, and 2 (7%) of 27
rapid progressors were M. fermentans positive. The PBMCs from 91 subjects were
tested for M. penetrans DNA and none was positive. The small proportion of M.
fermentans-positive patients indicates that the mycoplasma cannot be important in
the development of AIDS in the large majority of patients. Furthermore, no
association was found between its presence and more rapid HIV disease
progression.
PMID- 10678474
TI - Asymptomatic penile HPV infection: a prospective study.
AB - The occurrence of human papillomavirus (HPV) among males was analysed with the
polymerase chain reaction (PCR) method. Penile brush samples were taken once from
147 males attending for a control or for HPV non-related reasons, and consecutive
samples were collected from 88 males re-attending the clinic. Of the males
attending once, 13% (19/147) were HPV DNA positive and among the re-attenders 14%
(12/88) were initially positive as compared with 33% (29/88) who were positive at
least at one visit. Totally, 22 different HPV types were detected of which HPV 16
was most common, found in 6.4% (15/235), followed by HPV 42 found in 3.8%
(9/235). Among 14 HPV-positive males with at least one follow-up, 7 had
persistent infections with at least one HPV type, and transient HPV types were
observed in 9; but in 5 of them new types appeared at follow-up. Among sexually
active males subclinical/latent HPV infection is common and repeated sampling
increases its prevalence.
PMID- 10678475
TI - Detection of human cytomegalovirus retinitis and monitoring of ganciclovir
treatment using conjunctival swab with polymerase chain reaction in AIDS
patients.
AB - This report studies the accuracy of conjunctival swab polymerase chain reaction
(CS-PCR) for the diagnosis of human cytomegalovirus retinitis (HCMV) in AIDS
patients. PCR and virus culture were used for the detection of HCMV in
conjunctival swab, serum, and urine specimens from 38 AIDS patients between April
1996 and April 1998. The clinical utility of the identification of HCMV retinitis
by these 6 different methods was demonstrated by their prediction power to
estimate AIDS patients at risk of contracting HCMV retinitis. The sensitivity,
specificity, positive predictive value, and negative predictive value of CS-PCR
for the detection of HCMV retinitis were 91.5%, 80.9%, 60.8%, and 92.7%,
respectively; for serum PCR were 74.3%, 81.7%, 57.2%, and 90.3%; for urine PCR
were 100%, 17.3%, 20.4%, and 100%; for conjunctival swab culture were 22.7%,
100%, 100%, and 86%; for serum culture were 27.3%, 98.1%, 75%, and 86.4%; and for
urine culture were 90.9%, 44.2%, 25.6%, and 95.8%.
PMID- 10678476
TI - A survey of patients with Chlamydia trachomatis infection: sexual behaviour and
perceptions about contact tracing.
AB - The aim of this study was to evaluate how patients with Chlamydia trachomatis
infection perceived the legal enforcement of partner notification and to seek
their views on legislation impinging on their own sexual behaviour. The
investigation was performed at STD clinics in Stockholm, Sweden in 1997.
Consecutive patients (n=192) answered a questionnaire about sexual behaviour and
contact tracing. More men (40%) than women (21%) had had sexual intercourse
during the past 6 months with an occasional partner. The mean number (6 months
prior to this) was 2.3 partners (1-15) for men and 2.2 partners (1-21) for women.
Eighteen per cent admitted to having avoided disclosing the name of their
partner(s). Ninety per cent considered it beneficial that chlamydial infection
was regulated and that a named partner could be forced to undergo STD testing.
Partly based on this report, the government has recommended police enforcement to
be removed from the legislation as a tool for contact tracing in chlamydial
infections.
PMID- 10678477
TI - Condom use and 'withdrawal': exploring gay men's practice of anal intercourse.
AB - Some gay men who have unprotected anal intercourse avoid ejaculation-they
practise 'withdrawal'. Using data collected in 1997 from a sample of Sydney gay
men (n=625), we explored the relation between men's practice of ejaculation and
their use of condoms. We also investigated whether men who had unprotected
withdrawal but not unprotected ejaculation were more likely to think unprotected
withdrawal was safe, liked condoms less, liked anal intercourse more, or were
more sexually adventurous. Considering separately insertive and receptive anal
intercourse with regular and with casual partners, we found that the majority of
men who practised unprotected withdrawal also practised unprotected ejaculation.
Of those whose only unprotected sex was withdrawal ('true withdrawers'), most
never used condoms (they did not also have protected sex with ejaculation). True
withdrawers were compared with men who had unprotected ejaculation, who always
used condoms, who had no anal sex and who had no partners. Those who were true
withdrawers with casual partners were more likely to believe withdrawal was safe;
no group effects were found with regular partners. No significant differences in
condom attitudes were found. True withdrawers with regular partners liked anal
intercourse less than other men, but true withdrawers with casual partners were
indistinguishable from those who had unprotected ejaculation. True withdrawers
did not differ in sexual adventurousness from other men who had anal intercourse.
Most withdrawers avoided anal sex with ejaculation rather than use condoms.
Converting them into reliable condom users may be a considerable challenge for
health promotion.
PMID- 10678478
TI - Evaluation of a drama-in-education programme to increase AIDS awareness in South
African high schools: a randomized community intervention trial.
AB - A community intervention trial was undertaken in KwaZulu Natal, South Africa to
evaluate the effectiveness of a high school drama-in-education programme. Seven
pairs of secondary schools were randomized to receive either written information
about HIV/AIDS or the drama programme. Questionnaire surveys of knowledge,
attitude and behaviour were compared before and 6 months after the interventions.
One thousand and eighty students participated in the first survey and 699 in the
second. Improvements in knowledge (P=0.0002) and attitudes (P < 0.00001) about
HIV/AIDS were demonstrated in pupils at schools receiving the drama programme
when compared to pupils receiving written information alone. These changes were
independent of age, gender, school or previous sexual experience. In schools
receiving the drama programme, sexually active pupils reported an increase in
condom use (P < 0.01). It is important to provide resources to sustain such
programmes and to obtain stronger evidence of effect on behaviour by measuring
changes in HIV incidence.
PMID- 10678479
TI - Risk perception and counselling among HIV-positive women in Sao Paulo, Brazil.
AB - This study of HIV-positive women at a clinic for HIV/AIDS in Sao Paulo examined
their risk perception for HIV before they had learned of their diagnosis and
their experiences with pre- and post-test counselling. A sample of 148 women was
interviewed regarding demographics, HIV risk factors and risk perception, pre-
and post-test counselling, and sexual and reproductive conduct. The majority
(77%) had been infected by their partners--37% by an injecting drug user partner.
More than half (53%) did not perceive themselves at risk before learning of their
HIV status and, of 68 who had perceived themselves at risk, 29% did so only after
their partners became ill. The majority (64%) did not receive any kind of pre
test counselling. Post-test counselling was reported by 83% but 14% reported
being mishandled by a physician in the process. Findings suggest the importance
of prevention efforts to reduce women's barriers to learning about HIV status and
the necessity of improving the quality of pre- and post-test counselling.
PMID- 10678480
TI - Trend of antimicrobial resistance in Neisseria gonorrhoeae at New Delhi, India.
AB - We aim to monitor the trends of antimicrobial resistance in Neisseria gonorrhoeae
and to compare the results of antimicrobial sensitivity by disc diffusion and
minimum inhibitory concentration (MIC). Two hundred and eleven confirmed strains
of N. gonorrhoeae were subjected to antimicrobial sensitivity testing by disc
diffusion using penicillin, tetracycline, ciprofloxacin and ceftriaxone from 1995
to June 1999. Penicillinase-producing Neisseria gonorrhoeae (PPNG) were detected
by lodometric method. Minimum inhibitory concentration was determined by E test.
A low level of penicillin resistance and PPNG detected in 1996 was maintained
over the years. Significant increasing trend of tetracycline and ciprofloxacin
resistance with high MIC i.e. 2-96 microg/ml and 1-32 microg/ml respectively were
found. Ceftriaxone was found to be the drug of choice, being 100% sensitive.
Comparison of resistance pattern by the 2 tests showed satisfactory agreement.
Emergence of penicillin, quinolone and tetracyline resistance in N. gonorrhoeae
isolates from a major STD centre at New Delhi indicates the need for increased
awareness, prudent use of antimicrobials, and evaluation of new antimicrobials
for the treatment of gonorrhoea.
PMID- 10678481
TI - Lymphocytic interstitial pneumonitis in an HIV-infected adult: response to
antiretroviral therapy.
PMID- 10678482
TI - An annular erythema secondary to primary genital herpes.
PMID- 10678483
TI - Disseminated Penicillium marneffei in a patient infected with human
immunodeficiency virus.
AB - A case of a 31-year-old man with systemic Penicillium marneffei infection
acquired in Thailand and who developed endophthalmitis is described. This
presentation has not previously been reported. He responded to combined treatment
with intravenous and intravitreal amphotericin.
PMID- 10678484
TI - Sexual health knowledge of adolescents in a Great Yarmouth high school.
PMID- 10678485
TI - The need to exercise caution in the management of patients co-infected with HIV
and hepatitis B.
PMID- 10678486
TI - Four-drug salvage antiretroviral treatment including nelfinavir and efavirenz in
highly treated children with congenital HIV disease.
PMID- 10678487
TI - Behavioural and biomedical risk factors for the transmission of HIV/AIDS in
Bangladesh.
PMID- 10678488
TI - Evaluation and prediction of drug permeation.
AB - A major challenge confronting the pharmaceutical scientist is to optimize the
selective and efficient delivery of new active entities and drug candidates.
Successful drug development requires not only optimization of specific and potent
pharmacodynamic activity, but also efficient delivery to the target site.
Following advances in rational drug design, combinatorial chemistry and high
throughput screening techniques, the number of newly discovered and promising
active compounds has increased dramatically in recent years, often making
delivery problems the rate-limiting step in drug research. To overcome these
problems, a good knowledge of the pharmacokinetic barriers encountered by
bioactive compounds is required. This review gives an overview of the properties
of relevant physiological barriers and presents some important biological models
for evaluation of drug permeation and transport. Physicochemical determinants in
drug permeation and the relevance of quantitative and qualitative approaches to
the prediction and evaluation of passive drug absorption are also discussed.
PMID- 10678489
TI - Biochemical and pharmacological characteristics of a newly synthesized H+/K+
ATPase inhibitor, YJA20379-8, 3-butyryl-4-[R-1-methylbenzylamino]-8-ethoxy-1,7
naphthyridine, in pigs and rats.
AB - We have investigated the effect of the newly synthesized proton-pump inhibitor
YJA20379-8, 3-butyryl-4-[R-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, on
gastric mucosal proton pump (H+/K+-ATPase) activity, gastric acid secretion and
gastric lesions in experimental animals. In lyophilized pig gastric microsomes,
YJA20379-8 was shown to inhibit H+/K+-ATPase activity; the inhibitory effect was
not affected by pH, the IC50 (dose resulting in 50% inhibition) being 28.0 microM
and 30.0 microM at pH 6.4 and pH 7.4, respectively. The effect was fully reversed
by dilution and subsequent washing of the incubation mixtures of H+/K+-ATPase and
YJA20379-8, suggesting the reversible nature of the enzyme inhibition. In pylorus
ligated rats, YJA20379-8 administered by different routes (intraduodenal,
subcutaneous, intravenous or oral) resulted in dose-dependent suppression of
basal gastric acid secretion. The duration of antisecretory action of 30 mg kg(
1) YJA20379-8 given intraduodenally was very brief (less than 7 h). Pretreatment
with YJA20379-8 also dose-dependently prevented gastric lesions induced by
absolute ethanol and water-immersion stress in rats. These results suggest that
YJA20379-8 might exert its antiulcer activity partly by reversible suppression of
acid secretion and partly by protecting the gastric mucosa against ulcerative
stimuli.
PMID- 10678490
TI - Inclusion complexation of the sunscreen agent 2-ethylhexyl-p
dimethylaminobenzoate with hydroxypropyl-beta-cyclodextrin: effect on
photostability.
AB - The interaction between the UV filter, 2-ethylhexyl-p-dimethylaminobenzoate, and
unmodified and modified alpha-, beta- or gamma-cyclodextrins was studied in water
by phase-solubility analysis. Of the cyclodextrins available, only hydroxypropyl
beta-cyclodextrin caused a marked increase in the aqueous solubility of 2
ethylhexyl-p-dimethylaminobenzoate. The data from the solubility study indicated
the formation of a 1:1 (sunscreen-cyclodextrin) complex. The inclusion of the
sunscreen agent into the hydroxypropyl-beta-cyclodextrin cavity was confirmed by
thermal analysis and by nuclear magnetic resonance spectroscopy. Irradiation
induced degradation of 2-ethylhexyl-p-dimethylaminobenzoate was reduced by
complexation with hydroxypropyl-beta-cyclodextrin, this effect being more
pronounced in solution (the extent of degradation was 25.5% for the complex
compared with 54.6% for free 2-ethylhexyl-p-dimethylaminobenzoate) than in the
emulsion vehicle (the extent of degradation was 25.1% for the complex compared
with 33.4% for free 2-ethylhexyl-p-dimethylaminobenzoate). Although
photodegradation of the sunscreen agent is significantly reduced by formation of
the inclusion complex it is important to design a suitable vehicle. Inclusion of
2-ethylhexyl-p-dimethylaminobenzoate-DMAB into the hydroxypropyl-beta
cyclodextrin cavity limits interaction of the UV filter with the skin reducing
the side-effects of the formulation.
PMID- 10678491
TI - Absorption of vitamin K2 by dogs after oral administration of a soft gelatin
capsule formulation containing a new emulsion-type vehicle.
AB - This study has evaluated the performance of a newly developed vehicle for
administration of a drug in a soft gelatin capsule. The absorption of vitamin K2
in dogs after oral administration of the vitamin in a soft gelatin capsule
containing the newly developed vehicle was compared with absorption after
administration of a control formulation prepared by encapsulating the contents of
a commercially available vitamin K2 capsule (Glakay capsules 15 mg) in the same
type of soft gelatin. Under non-fasted conditions the profile of the plasma
concentration of vitamin K2 against time for the test formulation was comparable
with that for the control formulation in non-fasted dogs. Under fasted
conditions, however, both the maximum concentration (Cmax) and the area under the
plot of concentration against time (AUC) were significantly smaller for the test
formulation than for the control formulation. The Cmax and AUC for the test
formulation were about 10 times larger for non-fasted dogs than for fasted dogs
whereas values for the control formulation were about twice as large. These
results suggest that both formulations might require the presence of food or
digestive fluid components, or both, for better absorption of vitamin K2. It
seems that although the performances of the test and control formulations were
comparable in the presence of these components, the control formulation works
better in their absence. It should be also noted that, in contrast with the
results from the absorption tests, the dispersibility of the test vehicle in
water was much better than that of the control vehicle. This suggests that
dispersibility does not significantly affect vitamin K2 absorption. In
conclusion, although the new vehicle did not perform better than the control
vehicle in terms of vitamin K2 absorption, the performance of the control
formulation was comparable for non-fasted dogs. Because the new vehicle contains
considerably less surfactant than the vehicles currently used in soft gelatin
capsules, it could be a safer alternative for use under non-fasted conditions.
PMID- 10678492
TI - Statistical moments for placental transfer of solutes in man.
AB - The placental transfer of red blood cells and solutes in man has been
investigated by statistical moment analysis, using the impulse-response
technique. Model compounds of different lipophilicity (sucrose, water,
antipyrine, propranolol and labetalol) were injected with a vascular reference
(labelled red blood cells) as boluses into either the foetal or maternal
circulation of a single-pass perfused placental lobule. Maternal and foetal
venous outflow fractions were collected at intervals ranging from 1 to 600 s.
Perfusion was conducted at maternal flow rates of 4 and 6 mL min(-1) and foetal
flow rates of 2 and 3 mL min(-1), respectively, to yield a constant materno
foetal flow ratio of 2. The outflow concentration-time profile curves were
analysed by statistical moment analysis. The sum of foetal and maternal recovery
was close to 100% for red blood cells, sucrose, water and antipyrine, but lower
for propranolol and labetalol. The mean transit time (MTT) values ranged from 20
to 500 s. The normalized variance (CV2) for red blood cells in the foetal and
maternal circulation of the placenta were in the ranges 2.31 to 3.86 and 2.00 to
2.03, respectively. The shape of the outflow concentration-time profiles after
bolus input is consistent with that of vascular residence time models such as the
dispersion model. The heterogeneity in red blood cell transit times, as defined
by CV2, is greater than in either the perfused leg or perfused liver.
PMID- 10678493
TI - Effect of oral administration of fennel (Foeniculum vulgare) on ciprofloxacin
absorption and disposition in the rat.
AB - The aim of this study was to investigate the possibility of a drug-drug
interaction between ciprofloxacin and fennel (Foeniculum vulgare) in a rat model.
Pharmacokinetic assessment of ciprofloxacin was performed in two groups of male
Sprague-Dawley rats. One group (n = 5) received 20 mg kg(-1) antibiotic orally
with concomitant oral dosing of the aqueous fennel extract (2 g herb kg(-1))
whereas the controls (n = 5) received 20 mg kg(-1) oral ciprofloxacin. Blood and
urine samples were collected over 6 and 24 h, respectively, for quantitation of
ciprofloxacin by HPLC. A non-compartmental model was employed for pharmacokinetic
analysis. Major ingredients and metal cations in the fennel extract were
determined. Compared with the control, maximum plasma concentration, area under
the curve and urinary recovery of ciprofloxacin were significantly (P < 0.05)
lower, by 83, 48 and 43%, respectively, in rats receiving concomitant dosing of
the two agents. The relative bioavailability of ciprofloxacin, under the
influence of fennel, was estimated to be 0.52. In addition, its apparent volume
of distribution and terminal elimination half-life were significantly (P < 0.05)
increased, from 30.8 +/- 11.1 (L kg(-1)) and 2.0 +/- 0.4 (h) to 143.8 +/- 31.6 (L
kg(-1)) and 5.2 +/- 2.0 (h), respectively. Although none of the organic
components of fennel seemed to cause this interaction, the total amount of ten
metal cations measured was found to be 13 mg g(-1). Significant interaction
between ciprofloxacin and fennel was observed in this study. Absorption,
distribution and elimination of ciprofloxacin were all affected. These changes
might be because of the formation of a more lipophilic ciprofloxacin chelate in
the presence of relatively large amounts of metal cations. If, therefore, the two
therapeutic agents are used concurrently, an adequate dosing interval is needed
to ensure the efficacy of ciprofloxacin.
PMID- 10678494
TI - The mechanisms of immune suppression by high-pressure stress in mice.
AB - The effects of high-pressure stress on the induction of anti-sheep red blood
cells (SRBC) and of plaque-forming cells (PFC), and on thymus weight, were
studied in BALB/c mice in-vivo and in-vitro. The efficacy of high-pressure stress
in suppressing PFC and thymic involution was maximum when the stress was applied
1 h day(-1) for 2 days before immunization with SRBC. Both effects were blocked
by administration of indomethacin, atropine, naloxone or phentolamine before the
first application of stress, whereas hexamethonium and propranolol had no such
effect. Hexamethonium, naloxone and propranolol administered before the second
application of high-pressure stress blocked both effects. Prostaglandin and
acetylcholine given 24 h before application of high-pressure stress caused a
marked reduction in PFC count, but not in thymus weight. The reduced PFC count
caused by acetylcholine was blocked by pretreatment with indomethacin. When
adrenaline was injected 24 h after application of high-pressure stress a marked
reduction in PFC was observed, but without thymic involution. When adrenaline was
injected 24 h after prostaglandin injection the PFC count was also markedly
reduced, but not thymus weight. The decrease in PFC caused by two exposures to
stress or one exposure to stress plus injection of adrenaline was blocked by
diethylcarbamazine before the second exposure to stress or the injection of
adrenaline. In addition, normal spleen cells, were induced as suppressor cells
when incubated with the serum of stressed mice, but not when supplemented with
anti-leukotriene C4, D4 antibody. These data suggest that mice fall into a pre
stress condition via the release of prostaglandin after the first stress, and
then immunosuppression is induced in these prestressed mice via the release of
leukotriene C4, D4, caused by the activation of the autonomic nervous system by
the second exposure to stress.
PMID- 10678495
TI - Time-dependent striatal dopamine depletion after injection of 6-hydroxydopamine
in the rat. Comparison of single bilateral and double bilateral lesions.
AB - For future investigation of possible perturbation of circadian rhythm in animal
models of Parkinson's disease we needed an animal model providing lasting 80-100%
striatal dopaminergic depletion in rats, but without induced mortality. We have
thus compared the effects of a single hydroxydopamine bilateral striatal lesion
(SB-hydroxydopamine) with those of a double hydroxydopamine bilateral lesion (DB
hydroxydopamine) at the same dose (16 microg/striatum) by HPLC determination of
dopamine and 3,4-dihydrophenylacetic acid (dopac) levels in the striatum. Two
weeks after neurosurgery, SB-hydroxydopamine and DB-hydroxydopamine induced
dopaminergic depletion of at least 81% compared with control groups. After eight
weeks striatal dopaminergic depletion was only 60.97% in SB-hydroxydopamine rats,
suggesting a compensatory phenomenon, whereas in DB-hydroxydopamine rats
dopaminergic loss was stable at 88%. For the DB-hydroxydopamine group the
dopac/dopamine ratio was significantly increased at week 2 only, whereas no
significant change was observed for other groups. This increase might be
explained by increased dopamine turnover. We have demonstrated that striatal DB
hydroxydopamine injection induces lasting 80-100% neuronal loss, close to that
observed in the disease in man, without induced mortality, and provides a tool
which meets our experimental requirements.
PMID- 10678496
TI - Oestrogenic compounds modulate cytokine-induced nitric oxide production in mouse
osteoblast-like cells.
AB - Nitric oxide (NO) is a mediator of bone metabolism with effects on both bone
resorption and formation. Its production by both the constitutive and inducible
isoforms of nitric oxide synthase (NOS) is affected by oestrogen in several types
of cell and in tissues other than bone cells. Recently, oestrogens were found to
increase basal NO production by osteoblasts via enhanced activity or expression,
or both, of NOS-3. Inflammatory cytokines, however, increase NO by increasing the
expression of NOS-2. In this study we have examined whether cytokine-induced NO
production by osteoblastic cells was affected by oestrogenic compounds by
studying the effect of 17beta-oestradiol and the anti-oestrogens ICI164,384 and 4
hydroxytamoxifen on cytokine-induced NO production in oestrogen receptor positive
MC3T3-E1 osteoblast-like cells. Combinations of the inflammatory cytokines
interleukin-1beta, tumour necrosis factor-alpha, and interferon-gamma with
lipopolysaccharide stimulated NO production up to 11-fold. This cytokine-induced
NO production was further increased dose-dependently by the anti-oestrogens
ICI164,384 and 4-hydroxytamoxifen (133.3 +/- 3.2% and 146.0 +/- 13.2%,
respectively). 17Beta-oestradiol either had no effect on or slightly inhibited
cytokine-induced NO production. It did, however, dose-dependently counteract the
stimulatory effect of the anti-oestrogens. Concentrations of 17beta-oestradiol
needed to prevent the stimulatory effect of 4-hydroxytamoxifen were ca tenfold
that of ICI164,384. These findings show that, in addition to the stimulatory
effect of oestrogen on basal NO production by NOS-3, cytokine-induced NO
production is also affected by oestrogenic compounds in osteoblasts.
PMID- 10678497
TI - Effects of 5-hydroxytryptamine on the transintestinal electrical activity and
cardiovascular function of fawn-hooded rats in-vivo.
AB - Fawn-hooded rats, which have abnormal serotonergic function, were used to
investigate the receptors involved in 5-hydroxytryptamine (5-HT)-induced
intestinal secretion. The effects of 5-HT on secretion by the small intestine and
proximal colon, monitored as increased transintestinal electrical activity, and
on cardiovascular function, measured as changes in heart rate and blood pressure,
were compared in fawn-hooded and Wistar rats. The maximum fall in heart rate
induced by 5-HT (mediated by 5-HT3 receptors) was greater in fawn-hooded than in
Wistar rats. ED50 values (the doses resulting in 50% of the maximum effect) for
the 5-HT2-mediated increases in systolic pressure were lower for both 5-HT and 5
methoxytryptamine in the fawn-hooded group. The prolonged fall in diastolic
pressure mediated by 5-HT1-like receptors was significantly attenuated in fawn
hooded rats, with the maximum responses to 5-HT, 5-methoxytryptamine and 6
hydroxyindalpine reduced to 21%, 42% and 28%, respectively, of the values
obtained for Wistar rats. In fawn-hooded rats the small intestine was less
sensitive to the effects of 5-HT (ED50 = 47 nmol kg(-1); ED50 for Wistar rats =
23 nmol kg(-1)) and the maximum colonic response to 5-methoxytryptamine was
greater (7.0 mV compared with 4.3 mV in Wistar rats), but other indices did not
differ for the two strains. The responses to 6-hydroxyindalpine were similar in
fawn-hooded and Wistar rats. It is concluded that although the cardiovascular
response of fawn-hooded rats to 5-HT challenge is very different from that of
Wistar rats, this difference is not reflected in marked alterations in 5-HT
induced intestinal secretion. This is consistent with 5-HT stimulating secretion
via the activation of several different receptor subtypes so that any changes in
the receptor profile in fawn-hooded rats results in little alteration in the
overall intestinal response.
PMID- 10678498
TI - Effect of pretreatment with FTY720 and cyclosporin on ischaemia-reperfusion
injury of the liver in rats.
AB - The effect of pretreatment with FTY720 (2-amino-2-[2-(4-octylphenyl)ethyl]-1,3
propanediol hydrochloride) or cyclosporin, or both, on neutrophil-mediated injury
has been examined by use of a rat model of transient clamping of hepatic flow.
Pretreatment with FTY720 alone or with cyclosporin induced a marked reduction of
circulatory lymphocytes, whereas the use of these drugs in combination was very
effective at suppressing the elevation of the number of peripheral
polymorphonuclear neutrophils (PMN) after reperfusion. Pretreatment with
cyclosporin, with or without FTY720, significantly reduced hepatic damage,
whereas FTY720 alone tended to prolong hepatic damage. Pretreatment of
cyclosporin alone, but not in combination with FTY720, significantly reduced the
accumulation of PMN and led to lower myeloperoxidase levels in the damaged liver.
In conclusion, pretreatment with cyclosporin, with or without FTY720, reduced
hepatic damage after warm ischaemia-reperfusion, whereas pretreatment with FTY720
alone tended to prolong this damage.
PMID- 10678499
TI - Modulation of nitric oxide-dependent vascular and platelet function in-vitro by
the novel phosphodiesterase type-V inhibitor, ONO-1505.
AB - We have characterized the in-vitro modulation of both nitric oxide (NO)-dependent
vasodilator activity and anti-platelet function by the novel type-V
phosphodiesterase inhibitor, ONO-1505 (4-[2-(2-hydroxyethoxy)ethylamino]-2-(1H
imidazol-1-yl)-6-methoxyquin azoline methanesulphonate). ONO-1505 elicited
vasorelaxation in the rat isolated aorta. If the concentration of ONO-1505 was <
or = 10 microM the vasorelaxation was abolished by N(G)-nitro-L-arginine methyl
ester (L-NAME), by methylene blue, and by endothelial denudation. Furthermore,
pretreatment of the rat isolated aorta for 10 min with ONO-1505 in the presence
of L-NAME potentiated vasorelaxation to the NO-donor, sodium nitroprusside.
Similarly, ONO-1505, although having no effect on adenosine diphosphate (ADP)
induced rat platelet aggregation in-vitro, augmented established anti-aggregatory
effects of sodium nitroprusside. The data therefore show that the novel
phosphodiesterase V inhibitor ONO-1505 augments endogenous and exogenous
nitrovasodilator activity in-vitro; they also imply modulation of the NO pathway
in the haemodynamic actions of this compound, previously reported in-vivo.
PMID- 10678500
TI - In-vivo and in-vitro assessment of the free-radical-scavenger activity of Ginkgo
flavone glycosides at high concentration.
AB - Free radicals are involved in numerous skin diseases, especially inflammatory
reactions and photosenescence. To identify possible free-radical scavenging by an
original terpene-free Ginkgo biloba extract containing 33% Ginkgo flavone
glycosides, mostly quercetin and kaempferol derivatives, we studied its activity
by means of in-vitro and in-vivo experiments, using superoxide dismutase (SOD) as
a positive control. By means of an in-vitro electron-spin resonance (ESR) assay
we compared the activity of the Ginkgo extract with that of its two aglycones,
quercetin and kaempferol. Quercetin and Ginkgo extract had significant
antioxidant properties without pro-oxidant effect. In contrast, kaempferol, above
an optimum antioxidant concentration, behaved as a pro-oxidant. The in-vivo
experiments were conducted on an anti-inflammatory model. The cutaneous blood
flux which reflects the skin inflammatory level was recorded by means of a laser
Doppler perfusion imager. The data confirmed the free-radical-scavenging property
of both Ginkgo extract and SOD. The Ginkgo extract significantly inhibited (37%)
cutaneous blood flux to the same extent as SOD. These data confirmed the
antioxidant property of Ginkgo extract. A complementary spin-trapping technique
would enable identification of the free radicals involved. This Ginkgo extract
should be useful for protection of the skin against free radicals.
PMID- 10678501
TI - Isolation of opioid-active compounds from Tabernaemontana pachysiphon leaves.
AB - A procedure for prefractionation of crude plant extracts by centrifugal partition
chromatography (CPC) has been developed to enable rapid identification of known
positive compounds or false-positive compounds and to increase the chance of
identifying minor unknown-active compounds. The study explored the use of CPC as
a tool in the prefractionation step before investigation of bioactivity.
Fractions obtained by CPC from an ethanolic extract of Tabernaemontana
pachysiphon Stapf (Apocynaceae) were screened by means of an opiate-receptor
binding assay and an adenosine A1-receptor-binding assay. Fractions containing
fatty acids, which had false-positive effects on the assay, were identified, as
were unknown-positive fractions from which two opioid-active compounds,
tubotaiwine and apparicine, were subsequently isolated. The affinities (Ki) of
tubotaiwine and apparicine at the opiate receptor were 1.65 +/- 0.81 and 2.65 +/-
1.56 micromol, respectively. Both alkaloids had analgesic activity in the
abdominal constriction test in mice. CPC prefractionation led to the rapid
isolation of two opioid-active compounds, tubotaiwine and apparicine, from the
unknown-positive fraction; false-positive fractions were rapidly identified. Both
tubotaiwine and apparicine had affinity for adenosine receptors in the micromolar
range and also had in-vivo analgesic activity in mice.
PMID- 10678502
TI - Anti-inflammatory and antinociceptive effects in rodents of the essential oil of
Croton cajucara Benth.
AB - The plant Croton cajucara Benth. (Euphorbiaceae) is widely used in Amazonian folk
medicine for the treatment of a wide range of illnesses. In this investigation
the analgesic and anti-inflammatory properties of the essential oil from the bark
of C. cajucara Benth., administered orally, were determined in several standard
rodent models of pain and inflammation. We observed that pretreatment with
essential oil significantly reduced the latency of sleeping time evoked by
pentobarbital compared with the control group (P < 0.001). Doses of 100 or 1000
mg kg(-1) also increased the sleeping time induced by pentobarbital (30.9 +/-
3.91 and 52.1 +/- 15.6 min, respectively) compared with the negative control
(12.4 +/- 4.27 min). We investigated the antinociceptive effect of the essential
oil in chemical (acetic acid) and thermal (hot-plate) models of nociception in
mice. Dipyrone (200 mg kg(-1)) and the highest doses of the essential oil (1000
mg kg(-1)) significantly inhibited acetic acid-induced abdominal constriction in
mice (5.00 +/- 1.38 and 6.8 +/- 2.1 constrictions, respectively) compared with
the negative control (33.1 +/- 2). The same dose of essential oil also raised the
pain thresholds of mice in the hot-plate test and significantly (P < 0.05)
increased the latency at all observation times. In acetic acid-induced abdominal
constriction in mice pretreatment of the animals with naloxone (5 mg kg(-1))
significantly reversed the analgesic effect of morphine and of the essential oil
at the highest dose (1000 mg kg(-1)). The essential oil of C. cajucara was also
investigated for its anti-inflammatory properties. At the lowest dose (100 mg kg(
1)) the essential oil had anti-inflammatory effects in animal models of acute
(carrageenin-induced paw oedema in mice) and chronic (cotton pellet granuloma)
inflammation. The essential oil at doses of 50, 100 and 200 mg kg(-1)
significantly and dose-dependently inhibited carrageenan-induced oedema (49 +/-
5; 37 +/- 5; 34 +/- 8 mg, respectively) compared with the negative control (74 +/
8 mg). The essential oil (100 mg kg(-1)) also inhibited chronic inflammation by
38% whereas diclofenac inhibited it by 36%. However, the essential oil did not
inhibit the migration of neutrophils into the peritoneal cavity. These data show
that the essential oil from C. cajucara contains compounds that had a significant
antinociceptive effect when the oil was administered at the highest dose. This
effect seems to be related to interaction with the opioid system. The essential
oil also had a significant anti-inflammatory effect in acute and chronic
inflammation models when administered at lower doses. This effect seems to be
related to cyclooxygenase inhibition.
PMID- 10678503
TI - Investigation of plants used in Jamaican folk medicine for anti-bacterial
activity.
AB - We have started a systematic scientific study of folklore medicinal plants
currently used as alternative medicine in Jamaican society. In this initial
study, extracts of plants widely used by the islanders are studied for
antibacterial activity against five common pathogens; Streptococcus group A,
Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa and Escherichia
coli. These studies revealed that 25% (approx.) of the plant extracts had
antimicrobial activity against at least one of the microbes used. Subsequent to
these observations, extracts from Mikania micrantha were examined in detail. This
led to the isolation of two sesquiterpenoids, mikanolide and dihydromikanolide,
with activity against S. aureus and C. albicans. The results suggest that
traditional folk medicine could be used as a guide in our continuing search for
new natural products with potential medicinal properties.
PMID- 10678504
TI - Fluorimetric determination of ampicillin by use of non-toxic catalysts.
Estimation of beta-lactamase activity and parameters.
AB - A fluorescence assay based on the use of biological reducing agents as catalysts
rather than heavy metal ions has been developed for estimation of ampicillin
concentrations. The assay is based on the conversion of ampicillin to its
penicilloate, by treatment with sodium hydroxide, then neutralization, dilution
with 0.5 M acetate buffer at pH4 and heating for 30 min at 100 degrees C in the
presence of ascorbic acid (0.5 mg) and EDTA (50 microM). Reduced glutathione,
cysteine and N-acetylcysteine also catalysed the development of fluorescence. A
practical sensitivity range of 0.5-50 microM ampicillin was used. The assay was
used to estimate ampicillin in some biological solutions to which the antibiotic
has been added. Milk, blood serum, trypticase soy broth and nutrient broth
containing 25 microM antibiotic assayed at 18.5, 21.7, 16.5 and 14.7 microM,
respectively, with standard deviations between 1.2 and 0.7%. The low results were
attributed to binding of some ampicillin by proteins or peptides which were
removed by pretreatment. Urine containing 5 mM ampicillin assayed at 4.97 mM with
a standard deviation of 3%. A modification of the procedure was used to measure
beta-lactamase activity against ampicillin in several organisms in a fixed time
assay. Kinetic parameters of a commercial beta-lactamase preparation from
Bacillus cereus could also be determined by an additional modification. In both
instances a correction was required for the intrinsic fluorescence of ampicillin
remaining in the solution. The preparation examined had a Michaelis constant (Km)
of 0.32 mM, a maximum velocity (Vmax) of 5398 micromol ampicillin hydrolysed mg(
1) min(-1), an apparent catalytic constant (Kcat, turnover number) of 20,220 s(
1) and a Kcat/Km ratio of 0.63 x 10(7) M(-1) s(-1). The major advantage of using
this assay technique is that toxic metals are not used in the development of
fluorescence so it is more environmentally acceptable. The technique is useful
for examining beta-lactamase activity against ampicillin and might be useful for
pharmaceutical products-for determining available therapeutic levels and for
monitoring the activity of penicillin acylase against the penicilloate of
ampicillin.
PMID- 10678505
TI - Application of magnetoencephalography to the study of autism.
PMID- 10678506
TI - Cognitive correlates of the negative, disorganized, and psychotic symptom
dimensions of schizophrenia.
AB - Knowledge of the relationship between specific cognitive abnormalities and the
clinical symptoms of schizophrenia could give insight into the nature of their
underlying pathophysiology. Composite scores were generated for negative,
disorganized, and psychotic symptom ratings in 134 patients with schizophrenia
(DSM-IV criteria). Partial correlations (each composite corrected for the others)
were computed with neuropsychological measures. Negative symptoms were related to
poor performance on tests of verbal learning and memory, verbal fluency, visual
memory, and visual-motor sequencing. Disorganized symptoms were correlated with
lower verbal IQ and poor concept attainment. Psychotic symptoms had no
significant relationship with cognitive deficit.
PMID- 10678507
TI - Prevalence of obsessive-compulsive disorder in schizophrenia and significance of
motor symptoms.
AB - To investigate the differences between schizophrenic subjects with and without
obsessive-compulsive disorder (OCD), the authors systematically assessed 76
schizophrenic subjects for OCD. Subjects with and without OCD were then compared
with regard to motor symptoms, including catatonia, and several measures of
psychopathology. Treatment strategies were evaluated retrospectively. The 12
subjects with OCD (15.8%) had more motor symptoms, including catatonia, than non
OCD schizophrenic subjects. Some differences were found with regard to
psychopathological symptoms. Treatment strategies also differed in the two
groups. The high prevalence of motor symptoms in these subjects supports the
hypothesis of a basal ganglia-frontal lobe connection linking OCD with
schizophrenia.
PMID- 10678508
TI - Occipital atrophy is associated with visual hallucinations in Alzheimer's
disease.
AB - In this study of patients with Alzheimer's disease (AD), patients with visual
hallucinations were compared with patients who did not have visual hallucinations
to determine if selective occipital lobe atrophy is associated with visual
hallucinations. Seven AD patients with visual hallucinations were matched by
cognitive score to 7 AD patients without visual hallucinations and 3-D MRI images
obtained. A ratio of measured occipital volumes to whole brain volumes was
compared between the two groups. AD patients with visual hallucinations had a
significantly smaller occipital/whole brain ratio than AD patients without visual
hallucinations. These results suggest visual hallucinations in AD may be
associated with neuropathology of the occipital lobe.
PMID- 10678509
TI - Olfactory dysfunction discriminates probable Alzheimer's dementia from major
depression: a cross-validation and extension.
AB - The present study was conducted to cross-validate and extend the hypothesis that
olfactory dysfunction could discriminate between groups of patients with
Alzheimer's disease and major depression. Forty patients meeting the DSM-IV
criteria for either Alzheimer's disease or major depression (20 per group)
underwent assessment with the Pocket Smell Test (PST), a three-item screening
measure of odor identification, and the Mini-Mental State Examination (MMSE). A
PST score of < or = 1 (1 or 0 correct) discriminated between the groups with a
hit rate of 97.5% (sensitivity = 95%, specificity = 100%). The optimal hit rate
for the MMSE (< or =24) was less effective (hit rate = 90%, sensitivity = 80%,
specificity = 100%). Age, gender, and education had minimal impact on the PST for
both groups. Olfactory assessment continues to add to the diagnostic utility in
the differential diagnosis of Alzheimer's disease versus major depression in
elderly patients.
PMID- 10678510
TI - An instrumental study of the relationship between extrapyramidal signs and
psychosis in Alzheimer's disease.
AB - Neurobehavioral disturbances often coexist with extrapyramidal signs (EPS) in
patients with Alzheimer's disease (AD). In the present study, we examined the
relationships between delusions and hallucinations and EPS by using standard
observer ratings and sensitive electromyographic (EMG) measures in 52 patients
with probable AD. On the basis of observer ratings, 36.5% of the patients
exhibited psychotic features and 63.5% exhibited parkinsonism. Severity of
clinically rated parkinsonism and the EMG measure of bradykinesia were
significantly correlated with severity of neurobehavioral disturbances in this
sample. The association between parkinsonism and delusions and hallucinations
suggests a subcortical mechanism in the etiopathology of psychosis in AD.
PMID- 10678511
TI - Treatment of dementia-associated agitation with gabapentin.
AB - The authors describe the use of gabapentin in the treatment of 4 outpatients with
dementia-associated agitation. On the basis of clinical case reports and the
Overt Agitation Severity Scale, all 4 patients had reduced agitation with
gabapentin. Three of 4 patients were successfully titrated to a full dose of
2,400mg/day. These findings suggest a possible role for gabapentin in the
behavioral management of patients with dementia.
PMID- 10678512
TI - Normal cognitive performance in patients with chronic alcoholism in contrast to
patients with Korsakoff's syndrome.
AB - This study investigated which cognitive deficits are associated with chronic
alcoholism. Neuropsychological profiles and MRI brain structure volumes of 14
patients with Korsakoff's syndrome, 15 patients with chronic alcoholism, and 16
healthy control subjects were compared. The patients with alcoholism had a normal
cognitive performance and normal brain structure volumes. The patients with
Korsakoff's syndrome had performance deficits on tests of memory,
visuoperceptual, and executive functions, as well as reduced brain structure
volumes. The results suggest that the cognitive deficits cannot be ascribed to
mere chronic consumption of alcohol. If cognitive deficits are present in
patients with chronic alcoholism, this may point to an underlying brain disorder.
PMID- 10678513
TI - Relationship between symptoms and motoric subtype of delirium.
AB - For 46 patients with delirium who were consecutive referrals to a consultation
liaison psychiatry service, the authors describe the relationships between
symptoms, as rated on the Delirium Rating Scale, and delirium motoric subtypes,
as defined by Liptzin and Levkoff's criteria. Most cases were of the mixed
subtype (46%), 24% were hypoactive, and 30% were hyperactive. Overall scores
differed significantly among motoric subtype groups, being highest in the
hyperactive, lowest in the hypoactive, and intermediate in the mixed. On item
scores, the hypoactive group scored lower than the hyperactive group for
delusions, mood lability, sleep-wake cycle disturbances, and variability of
symptoms, but lower than the mixed group only for mood lability. The results
suggest that delirium presents as motoric subtypes that differ according to
symptom profile and severity of delirium. These subtypes may differ in their
underlying pathophysiologies, responsiveness to therapeutic interventions, and
outcome.
PMID- 10678514
TI - Is delirium after cardiac surgery related to plasma amino acids and physical
condition?
AB - The authors studied interrelationships between plasma levels of amino acids,
physical condition (as apparent from cortisol, albumin, and thyroid hormone
concentrations), and postoperative delirium in 296 patients undergoing elective
cardiac surgery. Both plasma tryptophan (Trp) and ratio of Trp to the other large
neutral amino acids (oLNAA) were reduced in delirious patients compared with
control patients. The lower availability of Trp for the brain in delirious
patients may lead to decreased serotonergic function. Besides, the ratio of
phenylalanine (Phe) to the oLNAA was increased in delirium, which may result in a
higher synthesis of cerebral dopamine and norepinephrine. Delirious patients were
also in poorer physical condition than nondelirious patients, having decreased
albumin level and increased ratio of inactive reverse triiodothyronine (T3) to
active T3. Decreased Trp and increased Phe availability may give rise to an
imbalance in cerebral neurotransmitters and thus contribute to delirium.
PMID- 10678515
TI - A neuropsychological comparison of depressed suicide attempters and
nonattempters.
AB - The neuropsychological performance of 18 older inpatients with major depression
who were admitted following a suicide attempt was compared with that of 29 older
depressed inpatients who had never attempted suicide. There was an interactive
effect of age and group on the Trail Making Test, part B, such that attempters
showed greater performance declines with age. No other differences were detected
between groups on a range of neuropsychological tasks. These findings are
discussed in the context of the methodological limitations of previous studies
and the need for future research to better elucidate the nature of the
relationships between age, cognitive functioning, and suicidal behavior.
PMID- 10678516
TI - Pedophilia and temporal lobe disturbances.
AB - Paraphilias may occur with brain disease, but the nature of this relationship is
unclear. The authors report 2 patients with late-life homosexual pedophilia. The
first met criteria for frontotemporal dementia; the second had bilateral
hippocampal sclerosis. Both were professional men with recent increases in sexual
behavior. In both, 18-fluorodeoxyglucose positron emission tomography revealed
prominent right temporal lobe hypometabolism. These cases and the literature
suggest that bilateral anterior temporal disease affecting right more than left
temporal lobe can increase sexual interest. A predisposition to pedophilia may be
unmasked by hypersexuality from brain disease. These observations have potential
implications for all neurologically based paraphilias.
PMID- 10678517
TI - Impaired auditory gating and P50 nonsuppression following traumatic brain injury.
AB - Traumatic brain injury (TBI) can produce persistent attention and memory
impairment that may in part be produced by impaired auditory sensory gating. The
P50 evoked waveform response to paired auditory stimuli appears to be a useful
measure of auditory gating. The first controlled measurement of the P50 ratio in
TBI patients is described: when 20 patients with persistently symptomatic TBI
were compared with 20 control subjects, the P50 ratio was significantly greater
in the TBI group. The potential neurophysiologic and therapeutic implications of
this finding in TBI patients who report symptoms consistent with impaired
auditory gating are discussed.
PMID- 10678518
TI - Interrelationships between nocturnal sleep, daytime alertness, and sleepiness:
two types of alertness proposed.
AB - The authors studied daytime sleepiness and alertness (based on the Multiple Sleep
Latency Test [MSLT] and Maintenance of Wakefulness Test [MWT]) and nocturnal
sleep in 22 patients with depression/anxiety and in 47 nondepressed patients with
sleep apnea. The patients underwent two overnight sleep studies followed by
daytime tests. In depressed patients, MWT scores correlated negatively with total
sleep time and stage 3. MSLT scores correlated negatively with total sleep time
and with sleep efficiency. Apneic patients showed a negative correlation between
MWT results and amount of stage 1 sleep. MSLT results correlated positively with
sleep onset latency on the preceding overnight sleep study. Thus, in depressed
patients, there is a paradox that with more disturbed sleep there is greater
daytime alertness. In contrast, the more disturbed the sleep is in sleep apnea
patients, the more difficult it is to maintain daytime alertness.
PMID- 10678519
TI - Clinical and neuropsychological profiles of obsessive-compulsive schizophrenia: a
pilot study.
AB - This pilot study compared characteristics of obsessive-compulsive (OC)
schizophrenic patients and a matched non-OC schizophrenic control group. The OC
schizophrenic group required more intensive clinical interventions and had a
poorer clinical course, lower levels of functioning, and longer periods of
hospitalization. They showed greater negative symptoms and more impaired
executive functioning. These findings suggest OC-schizophrenic patients may have
an atypical set of clinical and neuropsychiatric characteristics, perhaps
constituting a subgroup within the schizophrenia spectrum. Pathophysiology and
possible treatment implications require further study.
PMID- 10678521
TI - Perceptual aberration and schizotypy: a cautionary note.
AB - This study assessed 51 college students for associations between Continuous
Performance Test performance and schizotypy scale scores. Results suggest that
perceptual aberration scores, while generally correlated with overall schizotypy
scores, may not be adequate as a single-criterion measure of schizotypy.
PMID- 10678520
TI - Heritability heightens brain metabolite differences in schizophrenia.
AB - Single-voxel proton magnetic resonance spectroscopy was performed in 64 medicated
schizophrenic patients and 51 healthy subjects. Spectra were obtained from a
voxel in the left medial temporal lobe by using a 2.0-tesla whole-body magnetic
resonance imaging system. Schizophrenic patients showed a lower N
acetylaspartate/ creatine-phosphocreatine ratio than did healthy subjects, and
this reduction was greater in 13 patients with a family history of psychotic
disorders.
PMID- 10678522
TI - Treatment of pathological affect: variability of response for laughter and
crying.
AB - Pathological laughing and crying (PLC) is increasingly recognized to accompany
diverse neurologic conditions, although it remains poorly understood. The authors
describe 3 cases of amyotrophic lateral sclerosis (ALS) with an unusual change
from a predominance of pathological crying to laughter following drug treatment.
Possible explanations for this phenomenon are discussed.
PMID- 10678524
TI - "Hyperacusis" and origins of lowered sound tolerance.
PMID- 10678523
TI - Loss of recent memory after bilateral hippocampal lesions. 1957.
AB - Bilateral medial temporal lobe resection in man results in a persistent
impairment of recent memory whenever the removal is carried far enough
posteriorly to damage portions of the anterior hippocampus and hippocampal gyrus.
This conclusion is based on formal psychological testing of nine cases (eight
psychotic and one epileptic) carried out from one and one-half to four years
after operation. The degree of memory loss appears to depend on the extent of
hippocampal removal. In two cases in which bilateral resection was carried to a
distance of 8 cm posterior to the temporal tips the loss was particularly severe.
Removal of only the uncus and amygdala bilaterally does not appear to cause
memory impairment. A case of unilateral inferior temporal lobectomy with radical
posterior extension to include the major portion of the hippocampus and
hippocampal gyrus showed no lasting memory loss. This is consistent with Milner
and Penfield's negative findings in a long series of unilateral removals for
temporal lobe epilepsy. The memory loss in these cases of medial temporal lobe
excision involved both anterograde and some retrograde amnesia, but left early
memories and technical skills intact. There was no deterioration in personality
or general intelligence, and no complex perceptual disturbance such as is seen
after a more complete bilateral temporal lobectomy. It is concluded that the
anterior hippocampus and hippocampal gyrus, either separately or together, are
critically concerned in the retention of current experience. It is not known
whether the amygdala plays any part in this mechanismi, since the hippocampal
complex has not been removed alone, but always together with uncus and amygdala.
PMID- 10678525
TI - Cotard's syndrome in a young male bipolar patient.
PMID- 10678526
TI - The distributions of apoptotic cells in the medial preoptic areas of male and
female neonatal rats.
AB - The medial preoptic area (MPA) of the hypothalamus of the rat contains two
sexually dimorphic nuclei, the periventricular preoptic nucleus (PVpo) and the
medial preoptic nucleus (MPN). To examine the relationship between sexual
dimorphism and neuronal death, we examined the number of apoptotic cells in the
subdivisions of the MPA in neonatal rats of postnatal days 1 (P1), 4 (P4), 7 (P7)
and 14 (P14). Apoptotic cells in these areas were classified according to their
progression into three stages. P1 and P4 rats contained many apoptotic cells in
the subfield along the third ventricle, including the PVpo, and their number was
significantly larger in P1 males: in particular, the number of early-stage cells
was larger in males than females. The number of apoptotic cells in the MPN was
increased in P4 and P7 rats, although no significant sexual differences were seen
in the total number or in the number of each progressive stage of apoptotic
cells. In P14 rats, very few apoptotic cells were seen in the MPA. Our data
revealed that the distribution of apoptotic cells in the MPA of developing rats
depends on the sexuality, subdivision of the area and postnatal period.
PMID- 10678527
TI - Hemispheric asymmetry and corpus callosum morphometry: a magnetic resonance
imaging study.
AB - Previous post-mortem studies (Aboitiz, F., Scheibel, A.B., Fisher, R.S., Zaidel,
E., 1992. Brain Res. 598, 154-161 and Aboitiz, F., Scheibel, A.B., Zaidel, E.,
1992. Brain 115, 1521-1541) have shown an inverse association between asymmetry
in perisylvian areas and the size of a specific segment, the isthmus, of the
corpus callosum (CC) in males. The purpose of this work was to study in vivo the
association between hemispheric asymmetry and the total size of the CC in 35
right-handed subjects (16 males, 19 females; mean age 24.9 +/- 3.9). An MRI scan
was performed for each subject. The area of the right (RH) and left (LH)
hemispheres were measured from images in the sagittal plane and the area of the
CC from images in the mid-sagittal plane. The index of hemispheric asymmetry was
absolute value((LH - RH)/[(LH + RH)/2]). There was a negative correlation between
the absolute value of hemispheric asymmetry and the size of the CC in males (r =
0.55, P = 0.03) but not in females (r = -0.20, P = 0.42). These findings, like
those of Aboitiz et al. (Aboitiz, F., Scheibel, A.B., Zaidel, E., 1992. Brain
115, 1521-1541), suggest a sex-dependent decrease in interhemispheric
connectivity with increasing hemispheric asymmetry.
PMID- 10678528
TI - Direct projection from the cardiovascular control region of the cerebellar
cortex, the lateral nodulus-uvula, to the brainstem in rabbits.
AB - In decerebrate unanesthetized rabbits, electrical stimulation of the lateral
nodulus-uvula in the cerebellar vermal cortex evoked an increase in renal
sympathetic nerve activity, an increase in blood pressure and a decrease in renal
arterial blood flow, which were all in contrast to the effects reported
previously in the anesthetized rabbits. In order to identify the pathway
mediating these responses, we investigated the Purkinje cell projection from the
lateral nodulus-uvula using both anterograde (biotinylated dextran amine, BDA)
and retrograde (horseradish peroxidase, HRP) tracing methods in rabbits. When BDA
was iontophoretically injected into the lateral nodulus-uvula, labeled Purkinje
cell axons were found within and around the superior and inferior cerebellar
peduncles (SCP and ICP, respectively). Furthermore, terminal-like fields were
found in the dentate and vestibular nuclei as reported in previous studies.
However, the terminal-like patterns that we observed in the parabrachial nucleus
(PB) in the rabbit have not been reported yet. When HRP was microinjected into
the lateral PB, retrogradely labeled Purkinje cells were found in the lateral
nodulus-uvula. These results indicate that Purkinje cells in the lateral nodulus
uvula project into the vestibular nuclei via the ICP and to the lateral PB via
the SCP. We suggest that these two pathways mediating cardiovascular responses
have different sensitivities to anesthetics.
PMID- 10678529
TI - Suppression on neuronal responses by a metacontrast masking stimulus in monkey
V4.
AB - We studied the temporal characteristics of suppression in area V4 of the monkey
using a visual stimulus for metacontrast masking. Visual responses of V4 neurons
to a brief test stimulus presented within the receptive field were recorded, and
the effect of a mask stimulus that did not spatially overlap the test stimulus
was examined. Responses to the test stimulus were suppressed by the mask
stimulus, which either preceded or followed the test stimulus. To study the
temporal characteristics of suppression, the interval between the onset of the
test stimulus and that of the mask stimulus (stimulus onset asynchrony, SOA) was
varied. Maximum suppression occurred with a simultaneous presentation of the two
stimuli, and the suppression gradually weakened as the SOA increased. The
suppressive effect of the mask stimulus lasted on average about 77 ms in the
negative SOA (forward masking) and 65 ms in the positive SOA (backward masking).
These results indicate that surround suppression in V4 neurons has considerable
temporal width, which is longer than that previously reported in areas V1 and V2.
There were marked differences between the time course of suppression in V4
neurons in the present study and those reported in human metacontrast masking.
PMID- 10678530
TI - Interaction between nitric oxide and substance P on heat-induced inflammation in
rat paw.
AB - To elucidate the interaction between nitric oxide (NO) and substance P (SP) in
neurogenic inflammatory responses, we measured the change in the degree of Evans
blue leakage and NO levels in perfusate from the subcutaneous space in the rat
instep following noxious heat stimulation (47 degrees C for 30 min). Furthermore,
the effects of drugs affecting nitric oxide synthase were examined. Noxious heat
stimulation caused on an increase in NOx, or NO2- and NO3- into the perfusate in
parallel with plasma extravasation. Nw-nitro-L-arginine methylester (L-NAME: 100
mg/kg once daily.) intraperitoneally (i.p.) given five times (chronic treatment)
significantly suppressed the increase in Evans blue extravasation induced by heat
stimulation, whereas acute treatments with L- and D-NAME (100 mg/kg once, i.p.)
did not show any significant effect. NO release induced by heating also was
significantly suppressed by chronic pretreatment with L-NAME, but not by acute
treatment. SP (10(-5) M) applied into the perfusate caused a remarkable increase
in the NOx release into the perfusate. Intra-arterial injection of RP67580 (1
mg/kg) on the perfused side, but not SR48968 (1 mg/kg), significantly attenuated
the increases in Evans blue leakage and NOx release during heat stimulation.
These results suggest that heat-induced SP release from the peripheral endings of
small-diameter afferent fibers causes NO generation through NK-1R, and that this
gas act to elicit or enhance inflammatory responses.
PMID- 10678531
TI - Intrinsic and commissural connections within the entorhinal cortex. An
anterograde and retrograde tract-tracing study in the cat.
AB - Intrinsic and commissural connections within the entorhinal cortex (EC) were
examined in the cat by the anterograde and retrograde tract-tracing methods with
Phaseolus vulgaris leucoagglutinin and cholera toxin B subunit. Intrinsic axons
to the superficial layers (layers I-III) arose mainly from layers II, III, Vd
(deep part of layer V), and VI, were distributed more widely in the superficial
layers than in the deep layers, and terminated progressively more densely in more
superficial layers; most densely in layer I. In the medial entorhinal area (MEA)
and the ventromedial and the ventrolateral divisions of the lateral entorhinal
area (VMEA and VLEA), the longitudinal connections through the intrinsic fibers
to the superficial layers is often more restricted in rostral direction than in
caudal direction. In the dorsolateral division of the lateral EC (DLEA), the
longitudinal connections through the intrinsic fibers to the superficial layers
extended distantly in both rostral and caudal directions. Intrinsic fibers to the
deep layers (layers IV-VI) originated mainly from layers IV and Vs (superficial
part of layer V) and were distributed rather sparsely and diffusely; they were
distributed more widely in the deep layers than in the superficial layers.
Commissural axons to the homotopic EC regions originated from layers II and III
of the MEA and DLEA and terminated in all EC layers, most densely in layer I.
PMID- 10678532
TI - Histamine excites rat cerebellar Purkinje cells via H2 receptors in vitro.
AB - Recent neuroanatomical studies have revealed a direct hypothalamocerebellar
histaminergic pathway. However, the functional significance of the histaminergic
fibers in the cerebellum is not yet clear. In this study, the effects of
histamine on the firing of cerebellar Purkinje cells (PCs) were investigated in
vitro. Histamine predominantly produced excitatory (106/111, 95.5%) and in a few
cases inhibitory (5/111, 4.5%) responses in PCs. The histamine-induced excitation
was not blocked by perfusing the slice with low Ca2+ high/Mg2+ medium (n = 8),
supporting a direct postsynaptic action of histamine. The histamine H2 receptor
antagonist ranitidine effectively blocked the excitatory response of PCs to
histamine (n = 20), but triprolidine, an H1 receptor antagonist, could not
significantly block the histamine-induced excitation, or only very slightly
decreased the excitatory effect of histamine on the cells (n = 13). On the other
hand, the highly selective H2 receptor agonist dimaprit mimicked the excitatory
effect of histamine on PCs and this dimaprit-induced excitation was also blocked
by ranitidine (n = 20), but not triprolidine (n = 8). However, the H1 receptor
agonists betahistine and 2-thiazolylethylamine did not show any effect on the PCs
(n = 9 and 14). These results reveal that histamine excites cerebellar PCs via H2
receptors and suggest that the hypothalamocerebellar histaminergic fibers may
play an important role in functional activities of the cerebellum.
PMID- 10678533
TI - Heterosynaptic expression of depolarization-induced suppression of inhibition
(DSI) in rat hippocampal cultures.
AB - Depolarization-induced suppression of inhibition (DSI) is a transient suppression
of the inhibitory synaptic transmission, observed in the hippocampus and the
cerebellum, upon postsynaptic depolarization. Using rat hippocampal cultures, we
examined whether DSI is confined to the inhibitory synapses on the depolarized
neuron or, if DSI can spread to those on neighboring non-depolarized neurons.
Whole-cell recordings were performed in 108 neuronal pairs with the following
synaptic responses. Stimulation of one neuron evoked the inhibitory autaptic
currents (IACs) recurrently in that neuron and also elicited the inhibitory
postsynaptic currents (IPSCs) orthodromically in the other neuron. In 38 of 108
pairs, the postsynaptic depolarization caused transient suppression of IPSCs
(homosynaptic DSI). In 11 of the 38 pairs exhibiting the homosynaptic DSI, the
depolarization also induced suppression of IACs (heterosynaptic DSI). The
heterosynaptic DSI, like the homosynaptic DSI, depended on depolarizing pulse
duration and was blocked by a phorbol ester. These results suggest that DSI can
spread to the synapses on a neighboring non-depolarized neuron in rat hippocampal
cultures.
PMID- 10678534
TI - Directional tuning profiles of motor cortical cells.
AB - The directional tuning profiles of motor cortical cells are commonly described by
a cosine tuning function with three adjustable parameters (Georgopoulos, A.P.,
Kalaska. J.F., Crutcher, M.D., Caminiti, R., Massey, J.T., 1982. On the relations
between the direction of two-dimensional (2D) arm movements and cell discharge in
primate motor cortex. J. Neurosci. 2, 1527-1537). In this study the variation in
the shape of the directional tuning profiles among a population of cells recorded
from the arm area of the motor cortex of monkeys using movements in 20
directions, every 18 degrees, was examined systematically. This allowed the
investigation of tuning functions with extra parameters to capture additional
features of the tuning curve (i.e. tuning breadth, symmetry, and modality) and
determine an 'optimal' tuning function. These functions provided better fit than
the standard cosine one. The optimal function for the large majority of tuned
cells was unimodal (84%), and only for a few of them (16%) it was bimodal. Of the
unimodal cells, 73% exhibited symmetric and 27% asymmetric shape. The half-width,
sigma, at the midpoint of optimal tuning curves differed among cells from 30 to
90 degrees, with a median at 56 degrees. This is much narrower than in the
standard cosine tuning function with a fixed width of sigma = 90 degrees. It was
concluded that motor cortical cells are more sharply tuned than previously
thought.
PMID- 10678535
TI - When pyramidal neurons lock, when they respond chaotically, and when they like to
synchronize.
AB - We give an overview on the locking properties of perturbed regularly firing
pyramidal neurons, as a function of perturbation strength, self-spiking frequency
and perturbation frequency. For inhibitory perturbations, instead of locking
chaotic response emerges for a whole range of parameters. This suggests that
global synchronization on the set of inhibitory connections may easily be
achieved.
PMID- 10678536
TI - A new technique for implanting a fine-wire microelectrode for chronic recording
of unit activity from freely-moving mice.
AB - We report here a newly developed chronic implantation technique using an epoxy
coated fine-stainless steel wire (33 microm in diameter) to record single unit
activity from the brain of freely-moving mice with as little tissue injury as
possible. Since the fine-wire electrode is not capable of staying straight by
itself or of penetrating into the brain, a pair of permanent neodymium magnets
placed on a micromanipulator as well as below the animal's head was used for
stereotaxic implantation to keep the fine-wire straight and strong by the
magnetic fields. With those implanted electrodes recording of single units from
the hippocampal CA1 of freely-moving mice was performed during sleep and
wakefulness.
PMID- 10678537
TI - Should we still use nitrovasodilators to test baroreflex sensitivity?
PMID- 10678538
TI - How to measure baroreflex sensitivity: from the cardiovascular laboratory to
daily life.
AB - Arterial baroreflex function in humans is commonly assessed through a number of
laboratory tests based on quantification of the reflex responses in heart rate or
blood pressure to external stimuli applied to the cardiovascular system. Evidence
is available that these laboratory estimates of baroreflex sensitivity have both
pathophysiological and clinical relevance. Indeed, a number of studies have shown
that the sensitivity of the baroreceptor-heart rate reflex may have a prognostic
value in myocardial infarction, heart failure and diabetic patients, where
mortality seems to be inversely related to the sensitivity of cardiac baroreflex
modulation. A deeper insight into the features of daily-life baroreflex
cardiovascular control has been offered more recently by techniques based on
computer analysis of spontaneous blood pressure and heart rate fluctuations. This
innovative approach allows spontaneous baroreflex sensitivity to be assessed in
real life conditions, with no need for external stimulation of the patient as
required by the older laboratory techniques. This review will briefly survey the
methods most widely used to assess baroreflex function in humans, in the
laboratory and in daily life.
PMID- 10678539
TI - Controlled study of circadian rhythm of blood pressure in patients with
aldosterone-producing adenoma compared with those with essential hypertension.
AB - OBJECTIVE: The circadian rhythm of blood pressure in patients with aldosterone
producing adenoma (APA) is not well understood. We evaluated the circadian blood
pressure rhythm in such patients by comparison with that in patients with
essential hypertension (EHT). The latter are characterized by a nocturnal blood
pressure decline, the so called 'dipping' blood pressure pattern. DESIGN AND
METHODS: A total of 12 patients with APA and 36 patients with EHT who were
matched by age and sex, and who had no severe organic disorders, were
hospitalized to control their diet (low sodium) and activities. Ambulatory blood
pressure monitoring was conducted for 24 h. The 24-h blood pressure was divided
into waking blood pressure (0600-2130 h) and sleeping blood pressure (2200-0530
h). RESULTS: The two groups showed no significant differences in age, sex, serum
creatinine, plasma glucose, daily urinary sodium excretion, and left ventricular
mass index. Although the 24-h mean blood pressure was higher in APA (112 +/- 8
mmHg) than EHT (102 +/- 12 mmHg), the dipping mean blood pressure ratio (%),
which was calculated from the sleeping and waking blood pressures, did not differ
significantly between the two groups (93.2 +/- 5.4 versus 92.8 +/- 5.9).
CONCLUSION: The dipping ratio of blood pressure in patients with APA resembled
that of patients with EHT. Variables that would influence the circadian rhythm of
blood pressure were controlled during study. The results suggest that a circadian
blood pressure in patients with APA is of the dipping type, characterized by a
nocturnal blood pressure decline, when a low sodium diet is ingested.
PMID- 10678540
TI - Blood pressure and menopausal transition: the Atherosclerosis Risk in Communities
study (1987-95).
AB - OBJECTIVE: Blood pressure changes during menopausal transition have not been
studied previously using a biracial sample. We investigated whether menopausal
transition was associated with change in blood pressure in African-American or
white women. DESIGN, SETTING AND PARTICIPANTS: The prospective multicenter study,
the Atherosclerosis Risk In Communities (ARIC) Study (1987-95) was utilized.
Included were never-users of hormone replacement therapy (3,800 women, 44% of the
original sample). MAIN OUTCOME MEASURE: Changes in blood pressure were adjusted
for baseline age and body mass index, baseline blood pressure, antihypertensive
use, ARIC field center and weight change. The menopausal transition group was
compared to the non-transition group, separately, by ethnicity. RESULTS: Women
undergoing the menopausal transition did not differ significantly in regard to
systolic blood pressure change [5.2, 95% confidence interval (CI) 4.0-6.4] from
non-transitional women (4.6, 95% CI 4.0-5.2); adjustment for age, baseline
systolic blood pressure and other factors did not alter this finding.
Transitional women had significantly less diastolic blood pressure change (-0.5,
95% CI -1.1 to 0.2) than non-transitional women (-2.0, 95% CI -2.4 to -1.7, P=
0.000) but, after adjustment for other covariates, the result was not significant
African-American women had significantly (P= 0.003) higher systolic blood
pressure change compared to white women, but this difference became non
significant (P= 0.21) after restricting the sample to women younger than 55 years
of age. Interactions between menopausal transition and ethnicity were not
significant, either in systolic blood pressure or diastolic blood pressure
change. CONCLUSION: Menopausal transition is not associated with significant
blood pressure change in African-American or white women.
PMID- 10678541
TI - Effect of bisoprolol and atenolol on endurance exercise capacity in healthy men.
AB - OBJECTIVES: To compare the effects of a highly beta1-selective adrenoceptor
antagonist bisoprolol with those of atenolol and placebo on endurance exercise
capacity in young, healthy male volunteers. DESIGN: Twelve subjects randomly
received oral placebo, atenolol (100 mg/day) or bisoprolol (10 mg/day) for 3
weeks, following a double-blind cross-over design. METHODS: At the end of each
period, the subjects performed an endurance exercise test on the bicycle
ergometer at 70% of maximal aerobic power. Cardiac output was measured by means
of an automated CO2-rebreathing method. Venous blood was sampled before, during
and after exercise. RESULTS: Exercise duration was not significantly different
between the two drugs tested. Total exercise duration was significantly reduced
by bisoprolol (-19.4 +/- 6.7%, P< 0.01) (mean +/- SEM) and by atenolol (-29.8 +/-
6.6%, P< 0.001), compared with placebo. Atenolol and bisoprolol were equally
effective in lowering resting plasma renin activity, heart rate and systolic
blood pressure. Resting and exercise stroke volume were significantly increased
by both drugs, so that cardiac output was not significantly affected. Both drugs
induced significant decreases in plasma-free fatty acid concentrations during
recovery and blunted the exercise-induced increase. There were no significant
relationships between the reduction of exercise duration and the haemodynamic
changes or the degree of impairment of the exercise-induced increase in free
fatty acid release resulting from beta-blockade. CONCLUSIONS: It is concluded
that both drugs affect endurance exercise capacity in young, normotensive men,
with a tendency to a smaller reduction during bisoprolol treatment. Haemodynamic
variables are unlikely to be involved in the reduction of endurance exercise
capacity. The role of the reduced availability of plasma free fatty acids remains
unclear.
PMID- 10678542
TI - Fetal versus maternal determinants of the reduced fetal and placental growth in
spontaneously hypertensive rats.
AB - OBJECTIVE: Epidemiological studies indicate that a reduced birth weight and
enlarged placenta increase the likelihood of human cardiovascular disease later
in life. The relative importance of fetal versus maternal factors in these
phenomena is not known. To assess the relative role of genotypic versus
environmental factors in this effect, we examined whether the altered fetal and
placental growth rates and amniotic fluid volume of spontaneously hypertensive
rat (SHR) fetuses of the Okamoto strain, are modified by gestation in
normotensive Wistar- Kyoto (WKY) rat mothers and vice versa. DESIGN: One-day-old
SHR embryos were gestated for 16 days in either SHR or WKY recipients. Similarly,
1-day-old WKY rat embryos were gestated for 16 days in either SHR or WKY
surrogates. At 16 days, fetal and placental weights were recorded. Paternal and
maternal donor and recipient blood pressures, maternal body weight and average
litter size within the four groups were also studied. METHODS: One cell SHR and
WKY embryos were harvested from timed matings and transferred to psuedopregnant
mothers of the same or opposite strain. Timed matings required routine vaginal
smears for the detection of proestrus and the presence of sperm following
overnight matings. Harvested embryos were temporarily maintained in culture
medium in a 37 degrees C incubator until injection into the oviduct of
recipients. Blood pressures were meaured using indirect tail-cuff plethysmography
and a computerized data acquisition system. RESULTS: SHR fetal and placental
weights at 16 days gestation were significantly lower than WKY fetal and
placental weights, irrespective of maternal strain. At 16 days of gestation, the
fetal and placental weights of SHR fetuses gestated in WKY rat surrogate mothers
(0.21 +/- 0.01 g and 0.19 +/- 0.01 g, respectively) were not significantly
different from those of SHR gestated in a surrogate SHR mother (0.21 +/- 0.01 g
and 0.18 +/- 0.01 g, respectively). Similarly, the fetal and placental weights of
WKY fetuses gestated in a WKY rat (0.27 +/- 0.01 g and 0.25 +/- 0.01 g,
respectively) were unaltered by gestation in a SHR recipient (0.25 +/- 0.01 g and
0.23 +/- 0.01 g, respectively). The amniotic fluid volumes of SHR gestated in WKY
rats and those of WKY fetuses gestated in SHR were not significantly different to
each other (0.37 +/- 0.01 ml versus 0.38 +/- 0.01 ml, respectively) and were
intermediate between the values for SHR and WKY fetuses gestated in a mother of
the same strain (0.34 +/- 0.01 ml versus 0.44 +/- 0.02 ml, respectively).
CONCLUSION: The SHR fetus exhibited reduced growth rate and placental size
irrespective of maternal surrogate strain, suggesting that these measures are
likely to be determined by the fetus or the placenta and, presumably, are
independent of maternal blood pressure or altered electrolyte and hormonal
milieu.
PMID- 10678543
TI - Effect of ACE inhibition and angiotensin AT1 receptor blockade on renal and blood
pressure response to L-arginine in humans.
AB - OBJECTIVE: Nitric oxide (NO) may contribute to the actions of angiotensin
converting enzyme (ACE) inhibitors. In contrast, angiotensin type 1 (AT1)
receptor blockers (AT1B) have been considered to act exclusively by inhibiting
angiotensin II actions. However, recent experimental findings suggest that AT1B
actions may be also partly mediated by NO. In this study, we explored whether ACE
inhibitors and AT1B modulate hemodynamic responses to L-arginine (L-arg), a NO
precursor. METHODS: Systemic (Finapres) and renal hemodynamic responses to L-arg
(200 mg/kg body weight), associated with markers of systemic and renal NO
production, were assessed before (control) and after 3 weeks of randomized
pretreatment with the ACE inhibitor ramipril (5 mg/day for 3 weeks) or the AT1B
losartan (50 mg/day for 3 weeks) in nine healthy male subjects (33 +/- 2 years;
body mass index 25.5 +/- 0.5 kg/m2). RESULTS: Control L-arg did not influence
mean arterial pressure (MAP) (92 +/- 5 versus 90 +/- 5 mmHg; not significant). In
contrast, L-arg decreased MAP when administered after pretreatment with ramipril
(89 +/- 5 versus 83 +/- 4 mmHg; P< 0.01) or losartan (90 +/- 44 versus 86 +/- 4;
P< 0.05). Control L-arg infusion had no effect on renal plasma flow (RPF)
(paraminohippuric acid clearance) and renal vascular resistance (RVR), whereas
the glomerular filtration rate (GFR) (inulin clearance) decreased (98 +/- 4
versus 89 +/- 5 ml/min; P< 0.05), resulting in a decrease in filtration fraction
(P< 0.05). After ramipril, L-arg induced renal vasodilation as indicated by
significant changes in RPF (576 +/- 41 versus 669 +/- 21 ml/min; P< 0.01) and RVR
(P< 0.05). The GFR did not change statistically after ramipril pretreatment (91
+/- 3 versus 97 +/- 4 ml/min; not significant); however, the trend was different
as compared with control (F= 5.7, P < 0.05). L-Arg-induced renal vasodilation was
also observed after losartan (RPF, 637 +/- 34 versus 706 +/- 40 ml/min; P< 0.05).
Enhanced renal and systemic responses to L-arg after ACE inhibitor and AT1B were
associated with a rise in plasma L-citrulline levels, which was greater than
after control L-arg (P < 0.05). However, other indicators of NO activity such as
plasma and urinary cyclic guanosine 3',5'-monophosphate, and nitrates, remained
unchanged throughout all experiments. CONCLUSION: The results indicate that ACE
inhibitors and AT1B have a potential to enhance L-arg-induced vasodilation both
in systemic and renal vascular beds. However, these hemodynamic responses were
not associated with convincing changes in indicators of systemic or renal NO
activity, suggesting a contribution of NO-independent vasodilator mechanisms.
PMID- 10678544
TI - Adrenomedullin selectively inhibits angiotensin II-induced aldosterone secretion
in humans.
AB - OBJECTIVE: Adrenomedullin inhibits angiotensin II stimulated aldosterone
production in vitro and in vivo in experimental animals. The aim of this study
was to investigate the effect of adrenomedullin on angiotensin II and
adrenocorticotrophic hormone-stimulated aldosterone production in vivo in healthy
humans. DESIGN AND METHODS: Seven volunteers were studied in a quiet, temperature
controlled laboratory. After 35 min of rest, an infusion of placebo or
adrenomedullin (3 pmol/kg per min) was given over 60 min; 15 min after starting
this first infusion, a second infusion of angiotensin II (0.96 fmol/kg per min)
or adrenocorticotrophic hormone (0.1 mIU/kg per min) was co-infused and continued
for 45 min. RESULTS: Adrenomedullin significantly inhibited angiotensin II
stimulated aldosterone production: the increment in aldosterone on the placebo
day was 691 pmol/l compared with 552 pmol/l on the adrenomedullin day (P< 0.004).
Adrenomedullin did not inhibit adrenocorticotrophic hormone-stimulated
aldosterone or cortisol release. CONCLUSION: Adrenomedullin selectively inhibits
angiotensin II-stimulated aldosterone production.
PMID- 10678545
TI - Postural hypotension following N-type Ca2+ channel blockade is amplified in
experimental hypertension.
AB - OBJECTIVE: To determine the relative importance of the cardiac and vascular
sympathetic components of the orthostatic response to 90 degrees head-up tilt
after N-type calcium-channel blockade in normotensive (sham renal cellophane
wrap) and hypertensive (renal wrap) conscious rabbits. METHODS: The effects of N
type calcium-channel blockade with omega-conotoxin GVIA (omega-CTX, 10 microg/kg
i.v. bolus) were assessed in the absence or presence of cardiac block by
propranolol and methscopolamine. These were contrasted with the effects of alpha1
adrenoceptor antagonism (prazosin 0.5 mg/kg i.v. bolus, in the presence of
cardiac block) or ganglion blockade (mecamylamine 4 mg/kg i.v. bolus). RESULTS:
In vehicle (0.9% saline) treatment groups, the response to tilt consisted of a
small pressor effect (4 +/- 2 and 7 +/- 1 mmHg) and tachycardia (29 +/- 6 and 17
+/- 6 beats/min) in sham (n = 6) and wrap (n = 5) rabbits, respectively. After
prazosin administration (with cardiac block), there were significant falls in MAP
of 3 +/- 1 and 7 +/- 2 mmHg in sham (n = 7) and wrap (n = 6) rabbits,
respectively, in response to tilt omega-CTX caused postural hypotensive responses
of 8 +/- 2 and 13 +/- 2 mmHg in sham (n = 6) and wrap (n = 7) rabbits,
respectively, and 7 +/- 1 and 14 +/- 2 mmHg in sham (n = 7) and wrap (n = 7)
rabbits with prior cardiac block. Similarly, mecamylamine caused falls in MAP of
8 +/- 1 and 10 +/- 2 mmHg in response to tilt in sham (n = 6) and wrap (n = 9)
animals, respectively. CONCLUSION: Sympathetic vasoconstrictor effectors are
primarily responsible for maintaining blood pressure during tilt in conscious
rabbits. The postural hypotension caused by sympatholytic agents is about double
in hypertensive rabbits, and N-type calcium-channel blockade is as effective as
ganglion blockade at inducing this syndrome.
PMID- 10678546
TI - Relative influence of insulin resistance versus blood pressure on vascular
changes in longstanding hypertension. ICARUS, a LIFE sub study. Insulin Carotids
US Scandinavia.
AB - BACKGROUND: Insulin resistance is associated with hypertension. The relative
influences of hyperinsulinaemia and high blood pressure on vascular hypertrophy
and carotid distensibility is unclear in patients with longstanding hypertension.
METHODS: In 88 unmedicated patients with stage II-III hypertension and left
ventricular hypertrophy on electrocardiogram we measured blood pressure, minimal
forearm vascular resistance (MFVR) using plethysmography, intima-media thickness
(IMT) and the wall distensibility of the common carotid arteries using
ultrasound, and insulin sensitivity using a 2-h isoglycaemic hyperinsulinaemic
clamp. RESULTS: IMT was positively correlated to systolic blood pressure (r=
0.26, P < 0.05), whole body glucose uptake index (M/IG; r= 0.22, P< 0.05), age
(r= 0.24, P< 0.05) and negatively correlated to body mass index (r= -0.24, P <
0.05); IMT did not correlate to fasting serum insulin (r= -0.14, NS). In men (n =
64) MFVR was positively correlated to systolic blood pressure (r = 0.30, P <
0.05), but was unrelated to M/G and serum insulin. The distensibility of the
common carotid arteries was negatively correlated to systolic blood pressure (r =
-0.40, P< 0.001) and in untreated patients (n = 22) positively correlated to M/IG
(r = 0.47, P < 0.05). CONCLUSIONS: High systolic blood pressure was related to
vascular hypertrophy, whereas hyperinsulinaemia and insulin resistance were not,
suggesting that longstanding high blood pressure is a far more important
determinant for structural vascular changes than insulin resistance at this stage
of the hypertensive disease. However, hyperinsulinaemia and insulin resistance
were associated with low distensibility of the common carotid arteries in the
subgroup of never treated hypertensive patients.
PMID- 10678547
TI - Insulin levels during fasting and the glucose tolerance test and Homa's index
predict subsequent development of hypertension.
AB - OBJECTIVE: To determine whether there is a longitudinal relationship between
hypertension and hyperinsulinemia and to find the most useful parameter(s) for
predicting the subsequent development of hypertension. SUBJECTS AND METHODS: The
oral glucose (75 g) tolerance test (OGTT) was performed in 313 patients, who were
divided into three groups according to glucose tolerance based on the WHO
criteria: normal, borderline and diabetes mellitus. The fasting insulin (IRI)
levels, sigmaIRI (the sum of the insulin levels 0, 30, 60 and 120 min after the
OGTT), insulinogenic index and Homa's index, a candidate for the simple
assessment of insulin sensitivity, of the normotensive and hypertensive subjects
in each subgroup were compared. In addition, 145 normotensive subjects were
followed up for over 3 years and observed for the development of hypertension.
RESULTS: Hypertensive diabetic subjects had not only higher fasting IRI levels
and sigmaIRI values, but they also had higher Homa's indices than normotensive
diabetics. Normotensive subjects with normal glucose tolerance (n = 20) did not
develop hypertension. However, 16 out of 94 patients with borderline glucose
tolerance and five out of 31 diabetics became hypertensive. The incidence of
hypertension in the group with fasting IRI > or = 15, sigmaIRI > or = 150 or
Homa's index > or = 4 was between 5 and 9 times higher than that in the group
with fasting IRI < 10, sigmaIRI < 100 or Homa's index < 2. This difference was
still significant when multivariate analysis, including various factors such as
age, body mass index (BMI) and sex, was performed. CONCLUSIONS: These results
suggest that higher plasma IRI levels and/or insulin resistance are closely
related to the pathogenesis of hypertension in patients with diabetes mellitus.
Homa's index, fasting and sigmaIRI may be useful predictors of the subsequent
development of hypertension.
PMID- 10678548
TI - Safety of the combination of valsartan and benazepril in patients with chronic
renal disease. European Group for the Investigation of Valsartan in Chronic Renal
Disease.
AB - OBJECTIVE: Several experimental and clinical studies indicate that the renin
system may play a pivotal role in progressing renal disease. The combination of
an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker
could provide a higher degree of blockade of the renin-angiotensin system than
either agent alone. Such enhanced suppression might be of benefit for patients
exhibiting a progressive decline in renal function because of chronic renal
disease. METHODS: A pilot multinational, multicentre, randomized, active
controlled, parallel group open-label study has been conducted in a group of
patients with progressive chronic renal failure (creatinine clearance 20-45
ml/min) either with or without proteinuria and hypertension. The primary aim of
the study was to investigate the safety and tolerability of the combination of
valsartan and benazepril. Patients were randomly assigned to one of three groups:
group 1 received valsartan 160 mg once daily (n = 22); group 2 received valsartan
80 mg once daily plus benazepril 5 or 10 mg once daily (n = 42); group 3 received
valsartan 160 mg once daily plus benazepril 5 or 10 mg once daily (n = 44). The
study lasted for 5 weeks, and in groups 2 and 3 benazepril was added on top of
valsartan after the first week of therapy with the angiotensin receptor blocker.
RESULTS: Serum creatinine increased in all three groups (mean change within a
group: 11 micromol/l in group 1, P= 0.045; 9 micromol/l in group 2, P= 0.030; 15
micromol/l in group 3, P= 0.0006). Serum potassium also increased in all three
groups of patients (mean change within a group: 0.28 mmol/l in group 1, P= 0.28;
0.48 mmol/l in group 2, P= 0.0008; 0.36 mmol/l in group 3, P= 0.02). After 5
weeks of treatment, the largest decrease in blood pressure was observed in group
3 (the mean change from baseline in seated diastolic blood pressure (SDBP) and
seated systolic blood pressure (SSBP), respectively, were: -2.0 and -11.5 mmHg in
group 1; -7.6 and -15.4 mmHg in group 2; -12.6 and -21.6 mmHg in group 3). In
addition, both combination treatments resulted in the reduction of proteinuria.
The total number of patients with adverse experiences were 10 (45.5%), 14 (33.3%)
and 11 (25%) in groups 1,2 and 3, respectively. In six patients (5.6%) therapy
was discontinued as a result of adverse experiences. Only one patient in each of
the combined therapy groups withdrew from the study because of hyperkalaemia and
no patients were forced to withdraw because of an increase in serum creatinine,
acute renal failure or hospitalization. CONCLUSIONS: These results indicate that
short-term combination of an angiotensin-converting enzyme inhibitor and an
angiotensin receptor blocker is safe and well tolerated in patients with moderate
chronic renal failure.
PMID- 10678549
TI - Serum urate is associated with baseline renal dysfunction but not survival or
deterioration in renal function in malignant phase hypertension.
AB - BACKGROUND: There has been speculation whether serum uric acid levels are an
independent prognostic factor in patients with hypertension. OBJECTIVE: To
investigate the clinical associations and prognostic value of serum urate in
patients with malignant phase hypertension (MHT), by comparing clinical features
in patients with serum urate levels above and below the median levels for this
population, and secondly, by performing a survival analysis in these patients.
PATIENTS AND METHODS: Review of the data on 153 patients (98 males; mean age 50.3
years, SD 13.5) with MHT on the west Birmingham MHT register. Median uric acid
levels in this population was 0.41 mmol/l (6.9 mg/dl), with an interquartile
range of 0.34-0.50 mmol/l (5.7-8.4 mg/dl). Clinical characteristics of patients
with a serum urate <0.41mmol/1 (group 1) were compared to those with levels above
the median (0.41 mmol/l, group 2). RESULTS: Mean duration of follow-up was
similar in both groups. The mean diastolic blood pressure at presentation and
both mean systolic and diastolic blood pressures at follow-up were significantly
higher in group 2 (that is, those with high serum urate levels) (unpaired t test,
P= 0.039). There was also more renal dysfunction in group 2 patients with MHT,
with higher mean serum urea and creatinine levels, both at presentation and at
follow-up (unpaired t test, P< 0.01). The commonest causes of death were
myocardial infarction (n = 7), heart failure (n = 4), stroke (n = 10) and renal
failure (n = 5). There was no difference in mean survival duration between groups
1 and 2 (Kaplan-Meier, 64.6 versus 66.8 months; log-rank test, P= 0.519). Serum
urate levels also did not predict the rise in serum creatinine levels (log-rank
test, P= 0.84) or urea (P= 0.4033) amongst these patients. Using a multivariate
Cox proportional hazards analysis, the only independent predictors of outcomes
(death or the need for dialysis) were age (P = 0.007) and serum creatinine levels
at presentation (P = 0.0046). CONCLUSION: Our analysis of a large series of
patients with MHT shows that those with high urate levels had higher diastolic
blood pressures and greater renal impairment at baseline. At follow-up, patients
with median serum urate >0.41 mmol/l showed a greater deterioration in renal
function and higher blood pressures, but no significant difference in survival.
Serum urate levels also do not appear to be predictive of the deterioration in
renal function or overall survival in patients with MHT.
PMID- 10678550
TI - Relationship of renal histological damage to glomerular hypertension in patients
with immunoglobulin A nephropathy.
AB - OBJECTIVE: Studies of experimental animals show glomerular hypertension to be
important in the progression of glomerular disease. We evaluated this connection
clinically by examining the relationship between glomerular hemodynamics and
histological changes in patients with immunoglobulin (Ig)A nephropathy. METHODS:
The subjects were 23 patients with IgA nephropathy. All patients underwent renal
biopsies. Glomerular hemodynamics, in terms of glomerular capillary hydraulic
pressure (PGC) and the whole-kidney ultrafiltration coefficient, were calculated
from the renal clearance, plasma total protein concentration, and pressure
natriuresis relationship. The severity of glomerulosclerosis, tubulointerstitial
damage and mesangial matrix expansion was evaluated semiquantitatively. RESULTS:
PGC ranged from 33-69 mm Hg, and the mean arterial pressure (MAP) from 79-112 mm
Hg. Their correlation was not significant (r= 0.29, P= 0.18). PGC was
significantly correlated with the glomerulosclerosis score, and also with the
score for tubulointerstitial damage (r= 0.65, P < 0.001 and rs = 0.59, P = 0.007,
respectively), but not with the score for mesangial matrix expansion (r= 0.08, P=
0.72). MAP was significantly correlated only with the score for
tubulointerstitial damage (rs = 0.63, P = 0.004). In multiple linear regression
analysis of the histological changes and hemodynamics, the glomerulosclerosis
score and the score for tubulointerstitial damage were correlated with PGC, but
not with MAP. CONCLUSION: These clinical results support the speculation that
glomerular hypertension is involved in the glomerulosclerosis and
tubulointerstitial damage that occurs in IgA nephropathy.
PMID- 10678551
TI - Development of different phenotypes of hypertensive heart failure: systolic
versus diastolic failure in Dahl salt-sensitive rats.
AB - OBJECTIVE: There are two phenotypes of heart failure, systolic failure and
isolated diastolic heart failure with preserved left ventricular systolic
function. Although isolated diastolic heart failure frequently occurs, there are
only models for diastolic dysfunction unassociated with heart failure and models
with overt diastolic heart failure have not been established. We attempted to
develop two different models, i.e. diastolic and systolic failure models, based
on hypertension. MATERIALS AND METHODS: Dahl salt-sensitive rats were placed on
8% NaCl diet from 7 weeks old (7-week starting group) or 8 weeks old (8-week
starting group). As an age-matched control, Dahl salt-sensitive rats were
consistently placed on normal chow. In these rats, echocardiogram was serially
recorded, followed by hemodynamic and histological studies. RESULTS: The 7-week
starting rats showed a steep elevation in blood pressure and progressive left
ventricular hypertrophy, and fell into overt heart failure at approximately 19
weeks. The development of heart failure was not associated with a decrease in
left ventricular midwall fractional shortening or an increase in left ventricular
end-diastolic dimension as compared with the age-matched control, which mimics
the characteristics of clinically observed isolated diastolic heart failure. The
8-week starting rats showed a gradual rise in blood pressure and less progressive
left ventricular hypertrophy, and fell into heart failure at approximately 26
weeks with a decrease in mid-wall fractional shortening and an increase in left
ventricular end-diastolic dimension. Hemodynamic and histological studies at
failing stage revealed comparable elevation of left ventricular end-diastolic
pressure and comparable left ventricular fibrosis in both groups. CONCLUSION:
These two different models of overt heart failure may be useful as models of
isolated diastolic heart failure and systolic heart failure based on the same
hypertensive heart disease, respectively, and may contribute to discrimination of
the mechanisms of the development of the two different phenotypes of heart
failure.
PMID- 10678552
TI - How to assess endothelial function in human blood vessels.
PMID- 10678553
TI - Tumor markers in monitoring response to chemotherapy for patients with gastric
cancer.
PMID- 10678555
TI - Frequency of HLA-A alleles in Japanese patients with head and neck cancer.
AB - BACKGROUND: Association between certain human leukocyte antigen (HLA) types such
as HLA-A1 and -A3 and squamous cell carcinoma of the head and neck (SCCHN) has
been demonstrated in the Caucasian population. HLA typings in these studies were
performed by conventional serological methods. However, recent comparison studies
between serological and molecular typings have revealed that the former are often
inaccurate. METHODS: The frequency of HLA-A alleles in 100 Japanese patients with
SCCHN and 100 control subjects was determined by the polymerase chain reaction,
with primers specific for the HLA-A locus, in combination with dot-blot
hybridization with 31 sequence-specific oligonucleotides. RESULTS: The
frequencies of HLA-A*2602 and HLA-A*3303 were higher and those of HLA-A*2603 and
HLA-A*3101 were lower in the patients with SCCHN than in healthy controls, but
these differences were not statistically significant. In the 39 male patients
with laryngeal carcinoma, the most common malignancies in Japanese patients with
SCCHN, the frequency of HLA-A*2402 was significantly lower than that in the 80
male controls; however, after correction of the P value, statistical significance
was not confirmed. In oral carcinoma patients, the frequency of HLA-A*2402 was
significantly higher than that in healthy controls. CONCLUSIONS: These results
suggest that the contribution of certain HLA-A alleles to susceptibility to SCCHN
may differ between sites in the head and neck regions, despite these cancers
being of an identical histological type, and that HLA-A*2402 may influence the
development of oral carcinoma in Japanese patients.
PMID- 10678554
TI - Expression pattern of chemoresistance-related genes in human malignant brain
tumors: a working knowledge for proper selection of anticancer drugs.
AB - BACKGROUND: In addition to traditional modalities such as surgical intervention
and radiotherapy, chemotherapy is a common therapeutic method for human malignant
brain tumors. However, the effectiveness of chemotherapy is frequently hampered
by cancer cell chemoresistance, resulting in an unsatisfactory outcome. To
overcome this disadvantage, the proper selection of efficacious anticancer agents
is required. METHODS: The expression levels of chemoresistance-related genes,
MGMT, mdr1, MRP, MTIIA and GST-pi, in 28 surgical specimens of human brain tumors
and in 10 human glioma cell lines were examined by Northern blot analysis. In
addition, the SD10 values of human glioma cell lines against ACNU, CDDP, ADM and
VP16 were estimated by a cell survival assay. RESULTS: The expression levels of
each of the chemoresistance-related genes, except MRP, were generally higher in
brain tumors than those in non-neoplastic brain tissues. MGMT expression
correlated exclusively with ACNU resistance in all glioma cell lines examined (p
= 0.0002). The transcriptional level of mdr1 in the tumor cells correlated with
the SD10 values of VCR (p = 0.04) and ADM (p = 0.034). In contrast, the
expression levels of MTIIA and GST-pi did not correlate with resistance to any of
the drugs tested. A correlation of MRP mRNA expression with multidrug resistance
was not apparent in the 10 cell lines tested. CONCLUSIONS: The data indicate that
knowledge of the expression levels of MGMT and mdr1 may be particularly useful
for a more rational selection of drugs which are not influenced by these
resistance genes and which have improved efficacy against human brain tumors.
PMID- 10678556
TI - Lung cancer in patients who had received thoracoplasty for pulmonary
tuberculosis.
AB - BACKGROUND: In Japan in the 1950s, thoracoplasty was a powerful therapy for
pulmonary tuberculosis. Now there are many aged people who have tuberculosis
sequelae caused by thoracoplasty. We have encountered some cases of lung cancer
among these people. METHODS: To elucidate the features of lung cancer occurring
after thoracoplasty for pulmonary tuberculosis, we reviewed for analysis 20 such
cases. RESULTS: There were 17 men and three women, aged 55 to 78 years (mean 65
years). All had respiratory dysfunction and most were cigarette smokers. Lung
cancers were located in the upper lobes in nine cases, in the middle lobe in one
and in the lower lobes in 10. Ten lung cancers were in the thoracoplastied lung
and the remaining 10 in the opposite lung. Histologically, squamous cell
carcinoma was predominant (11 cases). Eight lung cancers were detected in stages
I and II and 12 in stages III and IV. Most cancer lesions were separate from
tuberculosis lesions. Surgical resection was selected in only three of 11 stages
I-IIIA cases in consideration of respiratory dysfunction and/or ventilatory
impairment due to thoracoplasty. Chemotherapy and/or radiotherapy were performed
in nine and supportive care alone was performed in eight. Fourteen patients died
of lung cancer and four died of cor pulmonale due to tuberculosis sequelae. Five
year survival was achieved in only one surgical case. Eight of the nine patients
who received chemotherapy or radiotherapy died within 1 year, and, further, seven
of eight patients who received supportive care died within 6 months. CONCLUSION:
Lung cancer in the patients who had received thoracoplasty occurred in each lung
and every lobe, independent of thoracoplasty. In addition, delay of detection was
such that stage III-IV cases were in the majority, there were some limitations in
therapeutic benefits related to thoracoplasty and the prognosis was very poor.
Physicians should avoid delay in the detection of lung cancer through careful
follow-up of such patients.
PMID- 10678557
TI - Phase I study of cisplatin and docetaxel plus mitomycin C in patients with
metastatic non-small cell lung cancer.
AB - BACKGROUND: Docetaxel, cisplatin and mitomycin C are some of the active drugs
used in the treatment of patients with metastatic non-small cell lung cancer
(NSCLC). The purpose of this study was to determine the maximum tolerated dose
(MTD) and recommended dose of the three drugs in combination for such patients.
METHODS: Chemotherapy-native patients with metastatic NSCLC were enrolled in this
study. The doses of docetaxel and cisplatin were fixed at 60 and 80 mg/m2,
respectively. It was planned to increase the dose of mitomycin C from 4 to 6 and
8 mg/m2. All drugs were administered on day 1 and repeated every 3-4 weeks.
RESULTS: All six patients received 60 mg/m2 of docetaxel and 80 mg/m2 of
cisplatin, three of them with 4 mg/m2 of mitomycin C (level 1) and the other
three with 6 mg/m2 of mitomycin C (level 2). Two of the three level 2 patients
experienced dose-limiting toxicities (DLTs) in first cycle: febrile neutropenia
and grade 3 hyponatremia. Based on these data, the MTD was concluded to be 60
mg/m2 for docetaxel, 80 mg/m2 for cisplatin and 6 mg/m2 for mitomycin C.
Evaluation of the data from all of the cycles, however, showed that four of the
six patients experienced DLTs. CONCLUSIONS: The addition of mitomycin C to
docetaxel and cisplatin resulted in relatively high toxicities. It was impossible
to use a high enough dose of mitomycin C to improve the survival of NSCLC
patients. We therefore concluded that further evaluation of this combination is
unwarranted.
PMID- 10678558
TI - Tumor markers CEA, CA19-9 and CA125 in monitoring of response to systemic
chemotherapy in patients with advanced gastric cancer.
AB - BACKGROUND: To evaluate whether tumor markers can be used to assess response to
systemic chemotherapy, we analyzed preliminarily the relationship between the
response to chemotherapy based on serial imaging and on change in serum tumor
marker level of CEA, CA19-9 and CA125. METHODS: We analyzed 26 patients with
advanced gastric cancer in whom at least one of the tumor markers CEA, CA19-9 and
CA125 was elevated before systemic chemotherapy with regard to the relationship
between the change in serum tumor marker level and response assessment by imaging
studies throughout the treatment course. A responder was defined as showing a >
or = 50% drop in tumor marker level for more than 4 weeks. RESULTS: The
sensitivity and negative predictive value of falling tumor marker level after
chemotherapy for a partial response in imaging was 100%. When patients were
categorized as responders or non-responders, a significant correlation was
observed between the assessment of response by tumor markers and by imaging
studies. The survival time of responders assessed by tumor markers was
significantly longer than that of non-responders. CONCLUSIONS: The measurement of
tumor markers might be useful in monitoring response and in predicting the
prognosis of patients with advanced gastric cancer treated with systemic
chemotherapy. Tumor markers may be used as a means of monitoring treatment in
patients when in an imaging study it is difficult to assess response to
chemotherapy in clinical practice. Further studies are required to confirm these
findings.
PMID- 10678559
TI - Clinicopathological comparisons of familial and sporadic cases in 219 consecutive
Japanese epithelial ovarian cancer patients.
AB - BACKGROUND: It is estimated that approximately 5-10% of epithelial ovarian cancer
patients in Western countries are associated with an autosomal dominant
inheritance with variable penetrance. There are a few reports of familial ovarian
cancer in Japan and considerable uncertainties remain regarding Japanese familial
ovarian cancer. The aim of this study was to clarify the clinicopathological
features of Japanese familial ovarian cancer. METHODS: We studied
clinicopathological findings for 219 consecutive epithelial ovarian cancer
patients treated at our institution from April 1987 to September 1997. RESULTS:
Eleven patients in nine families were diagnosed as familial ovarian cancer and
the incidence of familial cases was 5.0%. Most women (90.9%) with familial cases
were diagnosed as the breast ovarian cancer syndrome, whereas ovarian cancer
associated with hereditary nonpolyposis colorectal cancer was relatively rare
(9.1%). Serous adenocarcinoma, high histological grade, advanced FIGO stage and
breast cancer as multiple primary cancer were significantly more common in
familial cases compared with sporadic cases (p < 0.001, p < 0.05, p < 0.005 and p
< 0.005, respectively). Earlier age of onset was thought to be a characteristic
of familial ovarian cancer in Western countries; however, we did not find any
difference in age at diagnosis between familial and sporadic cases (53.4 vs 51.3
years). The prognosis of familial ovarian cancer remains controversial and our
data did not show a significant difference (p = 0.45) in prognosis between these
two groups. CONCLUSION: These findings, except for age at diagnosis, in Japanese
familial ovarian cancer are in accordance with the features of familial ovarian
cancer in Western countries.
PMID- 10678561
TI - Surgical management of primary lung cancer in an elderly patient with
preoperative empyema.
AB - A 74-year-old man with primary lung cancer developed preoperative empyema but was
successfully managed surgically. The patient was given a diagnosis of c-T2N1M0,
stage IIB, moderately differentiated squamous cell carcinoma, but before surgery
pneumothorax and empyema developed, resulting from rupture of the carcinoma.
Thoracic drainage, lavage and systemic administration of antibiotics improved his
empyema. As there were no malignant cells in the drainage fluid, right middle
lower bilobectomy, empyemal cavity resection and lymph node dissection were
performed. The bronchial stump was covered with an intercostal muscle flap.
Thoracic drainage, lavage and systemic administration of antibiotics were
performed for 6 days following the operation. The patient was discharged on the
27th postoperative day without any complications having developed. The
pathological diagnosis of the tumor was p-T4N2(#7)M0, stage IIIB, br(-), ly(+),
v(+), p3(pleura), pm1 and d0. He died of recurrence at home 18 months after the
operation. We believe the following to be the minimum requirements for surgical
management of such patients: (1) immediate thoracic cavity drainage and lavage
with systemic antibiotic therapy, aiming at infection control before surgery; (2)
prophylactic lavage of the thoracic cavity during and after surgery and (3)
coverage of the bronchial stump with an adequate flap. Six reported cases of
primary lung cancer with preoperative empyema are also discussed.
PMID- 10678560
TI - Goserelin acetate with or without antiandrogen or estrogen in the treatment of
patients with advanced prostate cancer: a multicenter, randomized, controlled
trial in Japan. Zoladex Study Group.
AB - OBJECTIVE: The aims of this randomized, controlled study were to investigate the
efficacy and safety of long-term monotherapy with the luteinizing hormone
releasing hormone agonist goserelin acetate compared with both short- and long
term combined androgen blockade. METHODS: Patients with advanced prostate cancer
(n = 371) were randomized to treatment with goserelin acetate alone or a
combination of goserelin acetate plus either long-term or short-term antiandrogen
(chlormadinone acetate) or short-term estrogen (diethylstilbestrol diphosphate).
RESULTS: There were no significant differences between the treatment groups with
respect to objective progression, overall survival or disease-specific survival.
Nevertheless, subgroup analysis suggested that patients with minimal disease or a
good prognosis might benefit more from combined androgen blockade than other
patients. Combined androgen blockade significantly reduced the incidence of
disease flare compared with goserelin acetate treatment alone. CONCLUSIONS:
Neither short- nor long-term combined androgen blockade had a survival advantage
over goserelin acetate alone.
PMID- 10678562
TI - Possible associations of rectal carcinoma with Schistosoma japonicum infection
and membranous nephropathy: a case report with a review.
AB - We report the first case of rectal carcinoma associated with S. japonicum and
membranous nephropathy. A 57-year-old Japanese man noticed narrowing of his
feces. He had lived in Yamanashi prefecture, an endemic area of S. japonicum. He
had suffered from nephrotic syndrome for about 1 year. Barium enema study showed
a severe stricture in the upper rectum and biopsy specimens from the tumor
demonstrated well differentiated adenocarcinoma and many ova of S. japonicum.
Sonography of the liver showed a network pattern and a linear high echoic area.
Low anterior resection with incisional biopsy of the liver and the right kidney
was performed. Histopathological findings showed well differentiated
adenocarcinoma and schistosomal ova. The total number of ova in the resected
colon amounted to 15,133, consisting of 2243 inside and 12,890 outside the
carcinoma. The nearer to the carcinoma the area was, the higher was the density
of ova. The findings of light microscopy and electron microscopy of the biopsy
specimen from the kidney were compatible with membranous nephropathy (stage II).
This case suggests that schistosomal ova have some effect on carcinogenesis and
nephrotic syndrome. In patients with nephrotic syndrome of unknown cause,
especially in inhabitants of endemic areas of S. japonicum, gastrointestinal
malignancy should be ruled out as an etiological factor. Sigmoidoscopy would be
useful for colorectal carcinoma surveillance in S. japonicum patients.
PMID- 10678563
TI - Cisplatin-5-fluorouracil therapy with remarkable effect and 5-year survival for
paraaortic lymph node metastases of rectal carcinoma in females: a case report.
AB - A 68-year-old woman was admitted because of a rectal carcinoma with huge
paraaortic lymph node metastases. Low anterior resection with regional lymph node
dissection was performed, leaving the paraaortic mass. After the operation,
cisplatin-5-fluorouracil therapy was used as supplemental chemotherapy. The
metastatic lymph nodes shrank remarkably in response to anticancer drugs. We
evaluated the effect of chemotherapy as a partial response. The physical
condition of the patient was well controlled for more than 4 years until she was
admitted again because of cardiac failure accompanied by relapse of abdominal
lymph node swelling. She died of cardiac failure 5 years and 3 days after the
operation.
PMID- 10678564
TI - The probability of a Japanese person developing cancer during their lifetime.
PMID- 10678565
TI - Gene regulation during the development of embryonic vascular endothelium-
reflections of an Irish postdoc in Japan.
PMID- 10678566
TI - Subtle signs may mask cancer-related emergencies.
PMID- 10678567
TI - Cancer statistics digest. Comparison of mortality and incidence trends in Japan.
PMID- 10678568
TI - International Agency for Research on Cancer (http://www.iarc.fr/)
PMID- 10678569
TI - Phenotypical and morphological alterations to rat sinusoidal endothelial cells in
arterialized livers after portal branch ligation.
AB - The hepatic sinusoids are preferentially supplied with portal venous blood and
equipped with fenestrated endothelial cells that are distinct from capillary
endothelial cells. We previously observed in rats that sinusoidal capillarization
proceeded concurrently with arterial blood supply during hepatocarcinogenesis.
This study aimed to clarify the inducing role of arterialization in sinusoidal
capillarization by investigating phenotypical, morphological and functional
alterations to sinusoidal endothelial cells (SECs) in arterialized rat livers
induced by portal branch ligation. At one week, after massive hepatic necrosis
following ligation, the livers were restored to their normal architecture without
causing post-necrotic fibrosis. At 12-21 weeks, they exhibited a normal histology
except for mild pericellular fibrosis which developed along sinusoids or between
adjacent hepatocytes. SECs expressed factor VIII-related antigen and showed a
decrease in the number of fenestrae and porosity, still lacking any basement
membrane but further retaining the functional capacity for carmine dye uptake.
Stellate cells, while occasionally associated with large amounts of collagen
bundles, contained many lipid droplets and expressed no alpha-smooth muscle
actin, indicating a quiescent property. Kupffer cells were commonly found within
the sinusoids. The present results indicate that arterialization of the liver
induces a partial (but not complete) transition of SECs into capillary-type
endothelial cells, suggesting that arterialization might be one of the factors
which induce sinusoidal capillarization in the development of hepatocellular
carcinoma.
PMID- 10678570
TI - The role of Kupffer cells in liver regeneration.
AB - The liver has a remarkable proliferative capacity after a partial hepatectomy.
Previous studies have indicated that Kupffer cells have the potential to exert
both stimulatory and inhibitory influences on hepatocyte proliferation. To
elucidate the role of Kupffer cells in liver regeneration, mice were selectively
depleted of Kupffer cells by injection of liposome-encapsulated dichloromethylene
diphosphonate (lipo-MDP) at day 3 after a two-thirds hepatectomy. Results showed
that liver regeneration was delayed after Kupffer cell-depletion. In control
mice, hepatocyte growth factor (HGF) mRNA expressions were enhanced during liver
regeneration and expressions of HGF were localized in fat-storing cells (Ito
cells). In Kupffer cell-depleted mice, the number of HGF-expressing cells
decreased in the regenerating liver, and expressions of HGF and its receptor (c
met) as well as other growth factors/cytokines were less prominent than in
control mice. In contrast, expressions of TNF-alpha, another potent cytokine
involved in liver regeneration, did not differ between Kupffer cell-depleted and
control mice during the regeneration. Administration of TNF-alpha antibody did
not reduce the expression of HGF or liver regeneration. These findings imply that
Kupffer cells play a stimulatory role in liver regeneration by enhancing HGF
expression via TNF-alpha-non-mediated mechanisms.
PMID- 10678571
TI - The induction of autophagic vacuoles and the unique endocytic compartments, C
shaped multivesicular bodies, in GH4C1 cells after treatment with 17beta
estradiol, insulin and EGF.
AB - The mechanisms for the formation of autophagic vacuoles were investigated using
GH4C1 cells, a rat pituitary tumor cell line, whose induction increases
intracellular levels of lysosomal proteinases and their mRNA by treatment with a
combination of hormones (17beta-estradiol, insulin and EGF). By ordinary electron
microscopy, autophagic vacuoles containing various undigested structures with or
without limiting membranes were abundant in the hormone-induced cells. These
vacuoles, also containing numerous small vesicles, appeared to be derived from
multivesicular bodies. In fact, there were also numerous C-shaped multivesicular
bodies which enclosed cytoplasmic portions, suggesting that these unique
structures are involved in the production of the autophagic vacuoles. Moreover,
the cytoplasmic portions enlapped by the C-shaped multivesicular bodies were high
in electron density and contained filamentous structures. By the cryothin-section
immunogold method, the C-shaped multivesicular bodies in some cases contained
lysosomal marker proteins such as cathepsins B and H, and Igp 120. Using an anti
actin monoclonal antibody, immunogold particles clearly labeled the cytoplasmic
portions enclosed by the C-shaped multivesicular bodies. Pulse-chase experiments
with horse radish peroxidase, a fluid-phase endocytic marker, revealed that the
incidence of the C-shaped multivesicular bodies labeled with horse radish
peroxidase peaked at 30 min after the beginning of chase incubation, whereas no C
shaped multivesicular body with horse radish peroxidase was detected in the cells
by cytochalasin D treatment. These results suggest that the C-shaped
multivesicular bodies occur in a transitional process from endosomes to lysosomes
by the action of actin filaments, and that this morphological change may be
essential for the production of autophagic vacuoles in the hormone-induced GH4C1
cells.
PMID- 10678572
TI - Heterogeneous localizations of Trk B among individual periodontal Ruffini endings
in the rat incisor.
AB - The present immunocytochemical study examined the localization of Trk B, a high
affinity neurotrophin receptor, in the neural elements of the periodontal
ligament of the rat incisor. In light microscopy, the immunoreactivity was
demonstrated in dendritic profiles in the alveolar half of the periodontal
ligament. Their location and morphological features indicated that they were
periodontal Ruffini endings. Occasional rounded cells associated with periodontal
Ruffini endings, which had immunonegative kidney-shaped nuclei, were
immunoreactive; these were judged to be terminal Schwann cells. Immunoelectron
microscopy revealed the heterogeneous localization of Trk B among individual
Ruffini endings. Some terminal Schwann cells contained immunoreactive products
for Trk B in the cytoplasm, while others did not. Similarly, a part of the
Schwann sheaths covering the axon terminals showed Trk B immunoreactivity. Most
axon terminals associated with periodontal Ruffini endings were immunopositive
for Trk B, though a few of them were immunonegative. The ordinary Schwann cells
did not contain Trk B immunoreactive products. These findings imply that Trk B is
required for the maintenance of periodontal Ruffini endings. The different
expression pattern of Trk B suggests that neuronal and glial elements comprising
individual periodontal Ruffini endings are subject to heterogeneous conditions
with regard to the requirement of Trk B.
PMID- 10678573
TI - Immunocytochemical localization of taurine in the developing retina of the
lefteye flounder Paralichthys olivaceus.
AB - Light microscopic immunolocalization of taurine, a sulfur-containing free amino
acid, was investigated in the developing retina of a lefteye flounder,
Paralichthys olivaceus, which exhibits metamorphic changes with rod cell addition
for 3-5 weeks after hatching. This immunocytochemical study of the developing
retina revealed: 1) From 3 to 13 days after hatching, intense immunostaining was
shifted from the surroundings of neural cells to the neural somata and processes
in the inner retina. 2) Intense immunoreactivity appeared also in the outer and
inner segments and basal processes (pedicles) of cone cells within 6 days or 13
days after hatching. 3) Lack of immunoreactivity was found in the outer segment
of rod cells from their appearance during metamorphosis. These findings are
discussed with the possible functional roles of taurine in the fish retina: 1)
involvement in cell differentiation and/or development; 2) protection of the
outer segments against light stimuli; and 3) regulation of neural transmission.
PMID- 10678574
TI - Reappraisal of potassium permanganate oxidation applied to Lowicryl K4M embedded
tissues processed by high pressure freezing/freeze substitution, with special
reference to differential staining of the zymogen granules of rat gastric chief
cells.
AB - The high pressure freezing/freeze substitution technique is known to yield a deep
vitreous freezing of tissues. Combination of this technique with Lowicryl K4M
embedding allows us histochemical studies of dynamic cellular processes with
improved structural preservation. The disadvantage of Lowicryl K4M embedding is
its poor electron density in electron microscopy. To address this problem, we
examined the effects of KMnO4 oxidation applied to Lowicryl K4M embedded rat
gastric glands processed by high pressure freezing. The KMnO4 oxidation-uranyl
acetate-lead citrate sequence succeeded not only in contrast enhancement of
cellular components, but also in differential staining of the zymogen granules of
rat gastric chief cells. This technique could be applied to semi-thin sections of
Lowicryl K4M embedded rat gastric glands. The KMnO4 oxidation-toluidine blue
staining provided sufficient contrast with regard to the zymogen granules.
Various experiments used in this study verified that the KMnO4 oxidation plays an
essential role in the differential staining of the zymogen granules. Combined use
of the KMnO4 oxidation with phospholipase A2-immunostaining demonstrated that
gold labeling was localized to the zymogen granules without the loss of
immunolabeling. Energy dispersive X-ray microanalysis revealed some manganese
depositions on the zymogen granules. It is highly anticipated that the KMnO4
oxidation will become a useful tool for histochemical investigations combined
with cryofixation/freeze substitution and low temperature embedding techniques.
PMID- 10678575
TI - Immunolocalization of tight junction proteins, occludin and ZO-1, and glucose
transporter GLUT1 in the cells of the blood-nerve barrier.
AB - Facilitated-diffusion glucose transporter GLUT1 is abundant in the blood-nerve
barrier. To observe the relationship between glucose transfer across the barrier
and the molecular architecture of the barrier, we examined the localization of
GLUT1 and tight junction proteins, occludin and zonula occludens-1 (ZO-1), by
immunofluorescence microscopy and immunogold electron microscopy in the rat
sciatic nerve. GLUT1 was enriched at the whole aspects of the plasma membranes of
the cells of the barrier: perineurial cells, and endothelial cells of the blood
vessels in the endoneurium. These GLUT1-positive cells were also positive for
occludin and ZO-1, both of which were localized at tight junctions. ZO-1
additionally was present in the GLUT1-negative cells not serving as the blood
nerve barrier. These observations suggest that occludin in the tight junctions
and GLUT1 at the plasma membranes in the cells of the barrier may constitute a
mechanism for the selective transfer of glucose across the barrier while
preventing the non-specific flow of blood constituents.
PMID- 10678576
TI - Porosity of the epithelial basement membrane as an indicator of macrophage
enterocyte interaction in the intestinal mucosa.
AB - The epithelial basement membrane of intestinal villi is perforated with numerous
small pores, through which free cells in the lamina propria communicate with the
enterocytes. This study was a comparative analysis of the pores in the basement
membrane by SEM after removal of the gut epithelium with OsO4 maceration. The
porosity as represented by the area fraction of the pores varied along the baso
apical axis of villi in patterns specific for each animal species examined:
consistent scantiness along the entire length of villi in mice, acute elevation
in the second and third distal one-sixths of villi in rats, and gradual
augmentation toward the villus tips in guinea pigs. Size distribution analyses of
the pores indicated their heterogeneous enlargement in the regions of elevated
porosity. Concomitant observation of lamina propria macrophages by histochemical
labelings and by conventional TEM showed that the cells specifically clustered
beneath the hyperporous basement membrane, with their thick processes penetrating
it. The spatially-regulated patterns of perforation of the epithelial basement
membrane indicate phase-specific interventions of lamina propria macrophages in
the maturation or aging of enterocytes, which steadily proliferate in crypts and
exfoliate at the villus tips.
PMID- 10678577
TI - Immunocytochemical demonstration of heat shock protein 25 in the rat
temporomandibular joint.
AB - The expression of heat shock protein 25 (Hsp 25) was investigated in the rat
temporomandibular joint by immunocytochemistry combined with confocal and
electron microscopy. Immunostaining with an antibody to Hsp25 was able to
demonstrate various cellular elements in the synovial membrane of the joint.
Intense immunoreaction for Hsp25 was recognized in certain cells comprising the
synovial lining layer. Confocal microscopic observation revealed two
characteristic profiles of the Hsp25-positive cells with cytoplasmic processes:
one extended thick and long processes towards the articular cavity, and the other
prejected horizontally slender processes which covered the synovial membrane.
Under the electron microscope, the immunoreactive synovial lining cells were
characterized by a well-developed rough endoplasmic reticulum and secretory
granules, suggesting that they can be categorized as fibroblastic type B cells.
The covering by the cytoplasmic extensions was confirmed by immuno-electron
microscopic observations. This cytoplasmic covering presumably performs a barrier
function and expedites the effective secretion/resorption of synovial fluids.
Since it has been proposed that Hsp 25 is associated with an estrogen receptor,
the immunopositive synovial lining cells were considered estrogen-target cells.
Immunoreactivity for Hsp25 was also observed in the chondrocytes of the
maturative and hypertrophic cell layers as well as in the cells of the articular
disk. A suggestion was made that Hsp25 might be involved in the inhibition of
apoptosis of those cells.
PMID- 10678578
TI - Microdissection or microspot CO2 laser for limited vocal fold benign lesions: a
prospective randomized trial.
AB - CO2 lasers have become an important technological advance and an integral tool
for the laryngeal surgeon since the 1960s. Surgeons have used lasers for a
variety of benign and malignant lesions in the larynx with good success. With
better understanding of the microarchitecture of the vocal folds and the
recognition of heat distribution into surrounding tissues that occurs with the
use of standard CO2 lasers, questions and concerns have been raised regarding the
use of the CO2 laser for benign lesions of the vocal folds. With the advent of
the microspot CO2 laser with a spot size of less than 250 microm, the potential
heat distribution to the deeper layers of the lamina propria has been reduced.
The microspot CO2 laser has been suggested to be an appropriate tool for the
excision of superficial benign lesions of the vocal fold and may be considered as
an appropriate treatment alternative to microdissection. Only a limited number of
studies have compared the efficacy of microdissection versus microspot CO2 laser
surgery in the larynx, and no prospective, randomized trials have been performed.
OBJECTIVE: This study was designed to compare microspot CO2 laser excision and
microdissection for superficial benign lesions confined to the free margin of the
vocal fold. STUDY DESIGN: A randomized, prospective trial comparing microspot CO2
laser excision and microdissection in the removal of nodules, polyps, and mucous
retention cysts of the vocal fold. METHODS: Acoustic and aerodynamic measures and
videostroboscopic and perceptual audio recordings evaluated by a panel of blinded
viewers and listeners were studied preoperatively and 2 to 3 weeks and 5 to 12
weeks postoperatively. Surgical and recovery times were compared between the two
groups. RESULTS: Thirty-seven patients met selection criteria and were enrolled,
21 in the microdissection group and 16 in the laser excision group. Significant
improvements in videostroboscopic parameters were found over time in both groups.
Significant improvements were noted for perceptual analysis over time for the
laser excision group with nonsignificant improvements over time for the
microdissection group. There was no difference in any measure between laser
excision and microdissection at the two postoperative visits. There was no
difference in surgical or recovery time between laser excision and
microdissection. Acoustic and aerodynamic parameters were noncontributory in
evaluating outcomes of treatment, since most values were normal before surgery.
CONCLUSION: No differences in clinical outcomes are identified when comparing
microdissection with laser excision of nodules, polyps, and mucous retention
cysts of the vocal folds.
PMID- 10678579
TI - Molecular pathology of cyclooxygenase-2 in neoplasia.
AB - Cyclooxygenase (COX)-2 levels are elevated in several types of human cancer
tissues. Nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both
the COX-1 and COX-2 protein, the two enzymes that convert arachidonic acids to
prostaglandins. Regular use of such NSAIDs significantly reduces the risk and
spread of some cancers. The objective of this study was to elucidate the
molecular pathology of neoplasms that overexpress COX-2. Epidemiological data and
clinical studies were analyzed and compared with results of studies of human
tumor tissues, animal models, and cultured tumor cells. COX-2, but not COX-1, is
highly expressed in human colon carcinoma, squamous cell carcinoma of the
esophagus, and skin cancer. COX-2 is inducible by oncogenes ras and scr,
interleukin-1, hypoxia, benzo[a]pyrene, ultraviolet light, epidermal growth
factor, transforming growth factor beta, and tumor necrosis factor alpha.
Dexamethasone, antioxidants, and tumor-suppressor protein p53 suppress COX-2
expression. COX-2 synthesizes prostaglandin E2 (PGE2) which stimulates bcl-2 and
inhibits apoptosis, and induces interleukin-6 (IL-6) which enhances haptoglobin
synthesis. PGE2 is associated with tumor metastases, IL-6 with cancer cell
invasion, and haptoglobin with implantation and angiogenesis. Drastic reduction
in polyp number results from COX-2 gene knockout as well as from selective COX-2
inhibition in a mouse model of human familial adenomatous polyposis. Nonselective
NSAIDs, for instance aspirin, and selective COX-2 inhibitors such as celecoxib
(SC-58635) and NS-398 suppress azoxymethane-induced colon carcinogenesis in rats.
Aspirin, indomethacin, and ibuprofen decrease cultured lung cancer cell
proliferation. Selective inhibition of COX-2 is preferable to nonselective
inhibition. It reduces cancer cell proliferation, induces cancer cell apoptosis,
and spares COX-1-induced cytoprotection of the gastrointestinal tract.
PMID- 10678580
TI - Wellness assessment: A role for laboratory medicine.
AB - Within the next 20-25 years, 20% of the U.S. population is expected to be 65
years old or older. Unless significant changes are made (ie, increased research,
improved treatment, and promotion of health and disease prevention), medical
costs will continue to rise but with fewer citizens to finance them. However,
this need not be the case. The 10 most common causes of death in the U.S. are
all, to a significant degree, lifestyle-related. Most of these diseases take
years or even decades to develop. By the time a physician makes a diagnosis, the
disease is already present. However, with a panel of laboratory tests, combined
with age, sex, family history, body mass index, blood pressure, and information
regarding lifestyle (diet, exercise, smoking, alcohol), an estimate can be made
regarding the relative risk for developing the major diseases/disorders. If
recommendations are followed, these conditions will decline, medical costs will
be reduced, and people will enjoy longer, healthier, and more productive lives.
PMID- 10678581
TI - Molecular predictive factors for local recurrence and distant metastasis of
breast cancer after lumpectomy with postoperative radiation therapy.
AB - To determine the risk factors associated with the recurrence and metastasis of
breast cancer after lumpectomy with postoperative radiation therapy, 112 cases
were studied who had been treated during a period of 11 years at the University
of Florida Health Science Center/Jacksonville. The patients were evaluated for
their age, race, and clinical stage, as well as the tumor grade, stage,
histological type, and node involvement. Among these cases, four (4%) recurred
locally within a year of treatment; 10 (9%) cases presented with distant
metastasis within three years. No obvious clinical risk factors were identified
for local recurrence; however, positive-node status seemed to be associated with
distant metastasis. The primary tumors of these cases were then studied using
immunohistochemical staining to evaluate the potential prognostic value of tumor
markers such as estrogen receptor (ER), progesterone receptor (PR), tumor
suppressor gene p53, HER-2/neu oncogene, and multi-drug resistance gene (MDR).
The expression of p53 was associated with all local recurrence cases as well as
50% of those who had metastasis. The expression of MDR was observed in 80% of the
distant metastatic cases. This preliminary result may warrant further studies on
larger number of cases to assess the predictive value of p53 and MDR in the
outcome of breast cancers in patients treated with postoperative radiation
therapy.
PMID- 10678582
TI - Fluorescence in situ hybridization (FISH) for detection of HER-2/neu
amplification in breast cancer: a multicenter portability study.
AB - Amplification and/or overexpression of HER-2/neu has been shown to be both a
prognostic and predictive marker in breast cancer. Recent studies have also
confirmed the efficacy of Herceptin (trastuzumab) as adjuvant therapy for
patients with overexpression of HER-2/neu. Therefore, it is critical that precise
and reproducible assays be used in the clinical laboratory setting for
determination of the HER-2/neu status in patients with breast cancer. The
objective of this study was to determine the portability (reproducibility between
different institutions) of the PathVysion HER-2 fluorescence in situ
hybridization (FISH) assay used for detection of amplification of the HER-2/neu
gene in formalin-fixed, paraffin-embedded tissue sections of invasive ductal
carcinoma of the breast. Study specimens consisted of one breast tumor with a
normal HER-2/neu copy number, two tumors with a low level, and one tumor with a
high level of HER-2/neu amplification. The PathVysion HER-2 assay was shown to be
highly reproducible on different assay days (n = 3) and between different
institutions (n = 5) in the detection of amplification of the HER-2/neu gene in
routinely processed clinical specimens of breast carcinoma. In addition, this
study examined the feasibility of enumerating FISH signals in 20 nuclei in
contrast to 60 nuclei per specimen. Although a modest increase in variation was
observed when analyzing 20 compared to 60 nuclei, the mean ratios were similar.
Therefore, analysis of as few as 20 nuclei with this FISH HER-2/neu assay may be
sufficient for determining the amplification level of the HER-2/neu gene.
PMID- 10678583
TI - Quantification of HER2 oncoprotein in fine-needle aspirates of the breast.
AB - Measurements of either HER2 gene overexpression or its gene-coded protein (p185)
are clinically useful for predicting prognosis in breast cancer. The measurements
are also useful for identifying metastatic breast cancer patients who may benefit
from Herceptin treatment. Since fine needle aspiration (FNA) of the breast has
become an increasingly popular technique for obtaining tissue specimens, we have
developed a sensitive method to quantify p185 in the aspirate. For this
procedure, p185 from the cell pellet of FNA is extracted with a buffer containing
Triton X-100, and the p185 is measured with an enzyme immunoassay. Most of the
malignant breast tumors (N=7) in this study were associated with elevated p185
concentrations (6/7, 319+/-222 U/mg), compared to the p185 concentrations in
normal breast tissue (42.8+/-35 U/mg, N=47) or benign lesions (43.1+/-20.2 U/mg,
N=22). Quantification of p185 in FNA may improve the assessment of breast cancer
patients, revealing whether they are at high risk and may benefit from Herceptin
treatment.
PMID- 10678584
TI - Glutathione-S-Transferase as a selective inhibitor of oncogenic ras-p21-induced
mitogenic signaling through blockade of activation of jun by jun-N-terminal
kinase.
AB - We have identified the intracellular detoxification enzyme, glutathione-S
transferase (GST), as a potent inhibitor of the activation of jun by its kinase,
jun-N-terminal kinase (JNK), in vitro. All three major isozymes (alpha, mu, and
pi) bind to JNK-jun complexes and inhibit activation of jun by JNK. We now find
that GST inhibits JNK-induced oocyte maturation in vivo and strongly inhibits
oocyte maturation induced by oncogenic ras-p21 protein, but not by insulin
activated normal cellular p21 protein. These results correlate with the finding
that oncogenic, but not insulin-activated normal, p21 induces high levels of
activated JNK. GST also strongly blocks induction of oocyte maturation by protein
kinase C (PKC) which is a critical downstream target of oncogenic but not normal
ras-p21. Thus, we have established a new function for GST as a potent
physiological inhibitor of the ras-JNK-jun pathway.
PMID- 10678585
TI - On the role of hydroxyl radical and the effect of tetrandrine on nuclear factor-
kappaB activation by phorbol 12-myristate 13-acetate.
AB - Nuclear factor kappaB (NF-kappaB) is considered to be an important target for
therapeutic intervention because of its role in the regulation of proinflammatory
and profibrotic mediators. The present study examined the role of hydroxyl (*OH)
radical and the effect of tetrandrine, an alkaloid extracted from the Chinese
medicinal herb Stephania tetrandra, on NF-kappaB activation by a tumor promoter,
phorbol 12-myristate 13-acetate (PMA) in human lymphoid T cells (ie, Jurkat
cells). Exogenous superoxide dismutase (SOD) enhanced the NF-kappaB activation by
PMA, while catalase blocked it. Formate, a scavenger of *OH radical, also was
inhibitory, as was deferoxamine, a metal chelator. These data suggest an
important role of *OH radical in PMA-induced NF-kappaB activation. Incubation of
the cells with tetrandrine prior to the stimulation of the cells was found to
inhibit PMA-induced NF-kappaB activation. Tetrandrine activity was so potent that
50 microM of tetrandrine was sufficient to inhibit activation of NF-kappaB
completely. Electron spin resonance (ESR) spin trapping was used to investigate
the antioxidant action of tetrandrine using 5,5-dimethyl-1-pyrroline N-oxide
(DMPO) as a spin trap. Tetrandrine is an antioxidant for both *OH and superoxide
(O2-)radicals. The reaction rate constant of tetrandrine with *OH is 1.4 x 10(10)
M(-1)sec(-1), which is comparable with several well established antioxidants,
such as ascorbate, glutathione, and cysteine. The Fenton reaction (Fe(II) + H2O2-
>Fe(III) + *OH + OH-) and xanthine/xanthine oxidase were used as sources of *OH
and O2- radicals. The free radical scavenging activity of tetrandrine is
responsible for its inhibition of PMA-induced NF-kappaB activation.
PMID- 10678586
TI - Cytogenetics as an aid in the diagnosis of lymphomas.
AB - Multiple classifications of lymphomas are available. Generally, distinctions are
made to identify low, intermediate, and high-risk groups. Histopathologic
differentiation is at times difficult. The revised European-American lymphoma
classification (REAL) uses histology, clusters of differentiation markers,
histochemistry, and cytogenetics for definitive identification. This work reviews
the karyotypic and FISH (fluorescent in situ hybridization) findings in some
common lymphomas. B-Cell lymphomas, which make up approximately 85-90% of
lymphomas, are associated with cytogenetic changes of +12, 13q14, 14q32, 2p11,
and 22q13. Translocations help to support the diagnosis of follicular cell
lymphoma t(14;18),(q32;q21), mantle cell lymphoma t(11;14)(q13;q32), and
Burkitt's lymphoma t(2;8),t(8;14) and t(8;22). T-Cell lymphomas may show changes
in 14q11,7p or 7q. Many of the lymphomas are characterized by complex karyotypic
changes. Specific FISH probes are useful in determining characteristic or
identifying marker chromosomes. Cytogenetic and FISH studies aid in the
diagnosis, correct classification, and evaluation of therapy for a variety of
lymphomas.
PMID- 10678587
TI - Acute renal artery and vein thrombosis after renal transplant, associated with a
short partial thromboplastin time and factor V Leiden mutation.
AB - Renal graft thrombosis is a rare but devastating complication of renal
transplantation. It accounts for one-third to one-half of early graft losses. We
report a patient with acute renal artery and vein thrombosis associated with
abnormally short activated partial thromboplastin time (aPTT) and factor V Leiden
mutation. Vascular thrombosis developed on the ninth post-transplant day and led
to a graft loss. Before transplantation, the patient had three episodes of
thrombosis of arteriovenous access for hemodialysis. Our case illustrates the
importance of investigating pretransplant patients for hypercoagulable states,
particularly those with short aPTT.
PMID- 10678588
TI - Urine protein electrophoresis and immunofixation electrophoresis supplement one
another in characterizing proteinuria.
AB - Urine protein electrophoresis (UPE) is often considered to have limited
usefulness in evaluating proteinuria that is not associated with gammopathies.
Unusual protein bands that are detected by UPE are commonly characterized by
immunofixation electrophoresis (IFE). In this paper, electrophoretic gel patterns
are shown to illustrate the greater sensitivity of IFE, compared to UPE. However,
UPE remains useful for three applications: (1) UPE provides distinctive patterns
that can indicate the source of proteinuria and is useful in assessing renal
diseases that are independent of gammopathy; (2) combined use of UPE and IFE can
avoid misinterpretations and repeated analyses of urine proteins, and (3) UPE can
be used in conjunction with IFE to improve the quantitation of Bence-Jones
proteinuria (BJP).
PMID- 10678589
TI - Modification of screening immunoassays to detect sub-threshold concentrations of
cocaine, cannabinoids, and opiates in urine: use for detecting maternal and
neonatal drug exposures.
AB - Testing for drugs of abuse in urine is commonplace in emergency departments and
neonatal units. However, the clinical sensitivity of immunochemical screening
methods is limited by the threshold concentrations used to distinguish between
positive and negative specimens. Immunochemical screening methods for cocaine
metabolite (benzoylecgonine), cannabinoids, and opiates in urine were
recalibrated to detect drugs at lower threshold concentrations. The precision and
linearity of the signals at the modified thresholds were verified by diluting
drug-positive urine specimens to concentrations below the conventional cutoff
concentration and measuring the rate signals in triplicate. To assess the
clinical performance of the modified methods, specimens that tested negative
using the unmodified assays were re-screened at the lower threshold, and
specimens that re-screened positive were submitted for gas chromatographic/mass
spectrometric (GC/MS) confirmation. Reproducibility of sub-threshold measurements
was comparable to the unmodified assays, and rate separations between successive
dilutions were sufficient to give semi-quantitative results. Using the lower
thresholds, drugs were detected in 4-5% of the subjects that had screened
negative at the conventional threshold concentration. GC/MS analysis confirmed
the presence of cannabinoids and cocaine metabolite in 74% and 84%, respectively,
of urine specimens that re-screened positive. Morphine, codeine, hydromorphone,
or hydrocodone was detected by GC/MS analysis in 31% of opiate-positive re
screens.
PMID- 10678590
TI - Expression of stress proteins HSP 72 & HSP 32 in response to endotoxemia.
AB - Pretreatment with heat decreases mortality and acute lung injury in the rat
septic shock model, presumably by the production of heat shock proteins (HSP).
However, endotoxin, a severe cell stresser, has not been shown to induce HSP 70.
We investigated the effects of severe endotoxemia on the expression of specific
protective stress proteins, including HSP 72 (inducible HSP 70), HSP 32 (heme
oxygenase-1), and HSP 90. Fifteen rats received intravenously either 3 mg/kg of
endotoxin (E. coli O127:B8 lipopolysaccharide, LPS) (n=9) or saline (n=6). Two hr
later the spleen was removed and splenocytes were separated into three groups and
analyzed for specific HSP by Western blot. In Group 1, both endotoxin-treated and
saline-treated splenocytes were incubated for 3 hr at 37 degrees C. In Group 2,
the splenocytes were washed twice, then heat shocked for 30 min at 42 degrees C
and subsequently incubated for 2.5 hr at 37 degrees C. In Group 3, splenocytes
were washed twice, then incubated for 3.0 hr at 37 degrees C. HSP 90 & HSP 70c
(constitutive) were present in all groups. Consistent with observations by
others, HSP 72 was not induced in Group 1. HSP 72 was induced in both the saline
treated and endotoxin-treated splenocytes after heating (Group 2). However, in
the absence of heat stress, HSP 72 was present in endotoxin-treated but not in
saline-treated splenocytes after incubation (Group 3). Conversely, HSP 32, while
present in Group 1 splenocytes, was not detected in the endotoxin-treated
splenocytes of Group 2 and Group 3, but was present in the saline-treated cells.
In conclusion, endotoxemic shock results in induction of HSP 72 and depletion of
HSP 32, but only after the cells have been washed and further incubated.
PMID- 10678591
TI - Effect of gliotoxin on development of diabetes mellitus in diabetes-prone BB/Wor
rats.
AB - The object of this investigation was to determine if gliotoxin, an
immunomodulating fungal secondary metabolite, is capable of preventing the
development of autoimmune diabetes mellitus in diabetes-prone BB/Wor rats.
Chronic treatment, consisting of 1 microg gliotoxin/g of body wt administered
three times weekly from the age of 30 days through 120 days, reduced the
incidence of diabetes from 90% diabetic by 120 days among vehicle-treated animals
to 56% diabetic among gliotoxin-treated animals. This result was significant by
life table analysis. Animals treated with gliotoxin maintained lower serum
glucose levels even in the pre-diabetic state than control (vehicle-treated)
rats. Gliotoxin at levels used in this study showed no appreciable effect on the
viability of rat insulinoma (RIN 38) cells in culture and only slightly decreased
their insulin secretion. Animals chronically treated with gliotoxin showed weight
gains comparable to those seen in controls, and the effect of gliotoxin on
peripheral blood leukocyte counts was not significant. The possibility that
gliotoxin exerted its effect through immunomodulating effects was implied by the
loss of white pulp in splenic follicles of gliotoxin-treated animals.
PMID- 10678592
TI - Pathoaetiology, epidemiology and diagnosis of hypertension.
AB - Hypertension is currently defined in terms of levels of blood pressure associated
with increased cardiovascular risk. A cut-off of 140/90 mm Hg is accepted as a
threshold level above which treatment should at least be considered. This would
give a prevalence of hypertension of about 20% of the adult population in most
developed countries. Hypertension is associated with increased risk of stroke,
myocardial infarction, atrial fibrillation, heart failure, peripheral vascular
disease and renal impairment. Hypertension results from the complex interaction
of genetic factors and environmental influences. Many of the genetic factors
remain to be discovered, but environmental influences such as salt intake, diet
and alcohol form the basis of nonpharmacological methods of blood pressure
reduction. Investigation of the individual hypertensive patient aims to identify
possible secondary causes of hypertension and also to assess the individual's
overall cardiovascular risk, which determines the need for prompt and aggressive
therapy. Cardiovascular risk can be determined from (i) target organ damage to
the eyes, heart and kidneys; (ii) other medical conditions associated with
increased risk; and (iii) lifestyle factors such as obesity and smoking.
Secondary causes of hypertension are individually rare. Screening tests should be
initially simple, with more expensive and invasive tests reserved for those in
whom a secondary cause is suspected or who have atypical features to their
presentation. The main determinants of blood pressure are cardiac output and
peripheral resistance. The typical haemodynamic finding in patients with
established hypertension is of normal cardiac output and increased peripheral
resistance. Treatment of hypertension should initially use nonpharmacological
methods. Selection of initial drug therapy should be based upon the strength of
evidence for reduction of cardiovascular mortality in controlled clinical trials,
and should also take into account coexisting medical conditions that favour or
limit the usefulness of any given drug. Given this approach, it would be
reasonable to use a thiazide diuretic and/or a beta-blocker as first-line therapy
unless there are indications to the contrary. Individual response to given drug
classes is highly variable and is related to the underlying variability in the
abnormal pathophysiology. There are data to suggest that the renin-angiotensin
system is more important in young patients. The targeting of this system in
patients under the age of 50 years with a beta-blocker (or ACE inhibitor), and
the use of a thiazide diuretic (or calcium antagonist) in patients over 50 years,
may enable blood pressure to be controlled more quickly.
PMID- 10678593
TI - Pharmacoeconomic considerations in the management of hypertension.
AB - Hypertension is highly prevalent in developed and developing countries (more than
30% of the adult population when a threshold value of 140/90 mm Hg is selected).
It constitutes one of the major cardiovascular risk factors and accounts for more
than 5% of total deaths worldwide. The economic impact of hypertension is
enormous, representing $US23.74 billion in the US in 1995 and approximately
$US1685 million in Spain in 1994. Direct costs amount to more than 50% of the
total costs of hypertension, and almost 70% of these are attributable to drug
treatment. Furthermore, hypertensive patients use medical services 50% more than
normotensive individuals, and hypertension represents one of the 3 leading causes
of visits to primary healthcare centres. When considering the cost effectiveness
of hypertension treatment, there is no doubt that it is cost effective in
comparison with other interventions, although some controversies exist, mainly
with respect to mild-to-moderate hypertension and to the long term versus short
term benefits. The controversy about the absolute risk of hypertension influences
the cost-effectiveness analysis. Because of the limitations of the available cost
effectiveness analyses, it is currently impossible to recommend the use of any
particular antihypertensive drug for all patients with hypertension.
Consequently, the choice of antihypertensive in any patient should be guided by
clinical experience and the recommendations of the present international
guidelines.
PMID- 10678594
TI - Diuretics as a basis of antihypertensive therapy. An overview.
AB - Diuretics have been, except for during a few recent years, the most commonly used
therapy for hypertension. Although use of these agents fell significantly in the
early 1990s, since then it has begun to increase again. Their recent return to
popularity reflects 3 major factors: (i) recognition of the effectiveness of much
lower dosages than previously used, thereby providing good antihypertensive
activity with fewer adverse effects; (ii) the excellent reductions in morbidity
and mortality achieved by low dosage diuretic-based therapy in multiple
randomised controlled trials in elderly patients with hypertension; and (iii) the
increasing recognition that some diuretic-induced shrinkage of effective blood
volume is essential for the adequate treatment of many, if not most, patients
with hypertension. Therefore, diuretics will probably continue to be the basis
for antihypertensive therapy, and the indapamide sustained release 1.5 mg
formulation provides all the essential characteristics of diuretic therapy.
PMID- 10678595
TI - Clinical positioning of indapamide sustained release 1.5mg in management
protocols for hypertension.
AB - Indapamide sustained release (SR) 1.5mg is a new galenic formulation that is
characterised by a relatively constant plasma concentration at steady state, with
only minor fluctuations during the 24-hour period. A dose-titration study of 3
doses of indapamide SR (1.5, 2 and 2.5mg) given once daily has shown that the 3
dosages are equipotent in lowering blood pressure, and have an effect similar to
that of indapamide immediate-release (IR) 2.5mg; all were statistically more
effective than placebo. The percentage of hypertensive patients whose serum
potassium was less than 3.4 mmol/L was significantly lower after indapamide SR
1.5mg than after indapamide IR 2.5mg. Neither indapamide formulation had any
significant effects on lipid profile, glucose, urea and serum creatinine; only
uric acid was slightly raised during the 2-month study. In an equivalence study,
indapamide SR 1.5mg and IR 2.5mg produced similar blood pressure reductions
(within the equivalence limit of +/-5mm Hg), whereas the percentage of patients
whose serum potassium fell to less than 3.4 mmol/L was lower in the IR 1.5mg
group than in the SR 2.5mg group. Antihypertensive treatment with indapamide SR
1.5mg once daily produced reductions in blood pressure in elderly patients with
systolic/diastolic or isolated systolic hypertension that were similar to
reductions with amlodipine 5 mg/day. The incidence of adverse effects was very
low in all studies with indapamide SR 1.5mg and very similar to that in the
placebo group, confirming thereby the improvement in the efficacy: tolerance
ratio with the new indapamide compound.
PMID- 10678596
TI - Paralytic vs. "nonparalytic" polio: distinction without a difference?
AB - Nonparalytic polio (NPP) is commonly thought to be synonymous with "abortive
polio," in which the poliovirus neither entered the central nervous system nor
damaged neurons. Described are two epidemic illness-"The Summer Grippe" and
Iceland disease-apparently caused by a low virulence but neuropathic type 2
poliovirus. Studies show that neuronal lesions in the brain and spinal cord and
muscle weakness were common in NPP, and epidemiologic studies document late-onset
weakness and fatigue in 14% to 42% of NPP survivors. These findings indicate that
clinicians should not require a history of paralytic polio, electromyographic
evidence of denervation, and new muscle weakness for the diagnosis of "Postpolio
Syndrome" but should be aware that NPP, and possibly even poliovirus-induced
"minor illnesses," can be associated with acute central nervous system damage and
late-onset muscle weakness and fatigue.
PMID- 10678597
TI - Nonparalytic polio and postpolio syndrome.
AB - We describe four cases of postpolio syndrome with typical histories, physical
examination results, and electrodiagnostic evidence of extensive anterior horn
cell disease, as well as the putative pathophysiology of postpolio syndrome in
persons with histories of nonparalytic polio and the diagnostic implications for
individuals older than 40 yr of age who are experiencing unexplained new
weakness, fatigue, and muscle or joint pain. Although the diagnosis of postpolio
syndrome traditionally has required a remote history of paralytic polio, many
persons such as the ones described here with typical symptoms of postpolio
syndrome have no clear history of paralytic disease and are being misdiagnosed.
With this in mind, we believe that the diagnostic criteria for postpolio syndrome
should be modified to include the following: a history of remote paralytic polio
or findings on history, physical examination results, and laboratory studies
compatible with poliovirus damage of the central nervous system earlier in life.
PMID- 10678598
TI - Late functional loss in nonparalytic polio.
PMID- 10678599
TI - Kyphoscoliosis ventilatory insufficiency: noninvasive management outcomes.
AB - OBJECTIVE: To determine the effects on symptoms, pulmonary function, sleep, and
other clinical variables of treating kyphoscoliosis-associated chronic alveolar
hypoventilation with nocturnal nasal ventilation. DESIGN: Sixteen patients with
kyphoscoliosis were treated with nocturnal nasal ventilation delivered by volume
cycled (seven patients) and pressure-cycled (nine patients) ventilators. Dyspnea,
morning headaches, fatigue, hypersomnolence, and perceived sleep quality were
assessed. RESULTS: All pretreatment symptoms improved significantly with nasal
ventilation. Likewise, PaO2 (mm Hg), PaO2/FlO2, PaCO2 (mm Hg), pH, and forced
vital capacity (in milliliters and as a percentage of predicted normal)
significantly improved with treatment. Maximum inspiratory pressures and maximum
expiratory pressures also significantly increased. Tidal volumes increased
significantly and breathing frequency decreased (not significant). Although
perceived sleep quality improved, as well as sleep oxyhemoglobin saturation,
there was no significant change in sleep architecture. Hospitalization days for
respiratory difficulties also decreased from 10.9 +/- 13.3 days in the 6 mo
before intermittent positive-pressure ventilation to 0 days during the first 6 mo
of treatment. CONCLUSIONS: Although not apparently affecting sleep architecture,
nocturnal nasal ventilation can significantly improve nocturnal and daytime blood
gases, pulmonary function, and symptoms of hypoventilation for patients with
severe kyphoscoliosis.
PMID- 10678600
TI - Balance, mobility, and falls among elderly African American women.
AB - OBJECTIVE: To compare balance, mobility, recent falls, and injuries among elderly
African American and white women. DESIGN: This was a nonexperimental study.
Participants, who were older than 65 yr of age, able to walk at least 30 ft, not
residing in a nursing home, and with no acute medical problems, were recruited
from 17 senior citizens' community centers. RESULTS: Compared with white women
(n=180), African American women (n = 118) took fewer medications, had greater
body mass indexes, had less muscle strength, and had more medical conditions and
neurologic abnormalities. Additionally, these women were less active and had
poorer performances on an obstacle course. The two groups had a similar histories
of falls and injuries. For both groups, activity level and neurologic findings
were predictors of obstacle course performance. For white women, muscle strength
was an additional predictor of obstacle course performance. An additional
predictor for African American women was range of motion. CONCLUSION: The poorer
balance and mobility of African American women compared with white women may have
consequences such as their functional dependence, resulting in their greater use
of hospitals and formal and informal health services.
PMID- 10678601
TI - Temporal effects of isometric contraction maneuvers on threshold sural amplitude.
AB - OBJECTIVE: To investigate the effect of isometric biceps brachii contraction and
neck flexion on the time course of threshold sural amplitude. DESIGN: Twelve
healthy subjects, who were asked to lie supine on an examination bench, performed
1 min of muscle contraction. The sural sensory nerve action potential was
recorded before, immediately after, and at 2-min intervals after muscle
contraction. The preexercise level of stimulus intensity remained unchanged for
sural readings throughout the entire course of the experiment. RESULTS: The
temporal changes in sensory nerve action potential amplitudes for both maneuvers
were similar (P = 0.9734, two-way interaction). The mean sural amplitude after
neck flexion increased from 6.0 +/- 2.9 microV (SD) to 10.6 +/- 6.6 microV (SD)
10 min after contraction. Similarly, mean sural amplitude increased from 6.5 +/-
1.8 microV (SD) to 14.5 +/- 9.7 microV (SD) 8 min after biceps brachii
contraction. Statistical analysis performed using repeated measures with post hoc
least significant difference showed a significant temporal effect in the two
groups (P = 0.04). CONCLUSION: The temporal responses of threshold sural
amplitudes after isometric biceps brachii contraction and central reinforcement
neck flexion maneuvers are nearly identical with regard to increase in the
amplitude.
PMID- 10678602
TI - Botulinum toxin injection of spastic finger flexors in hemiplegic patients.
AB - OBJECTIVE: To assess the outcomes of botulinum toxin injection of spastic finger
flexors followed by intensive training of finger extensors. DESIGN: Fourteen
subjects with chronic hemiplegia spasticity of the upper limb had
electromyographic-guided botulinum toxin injection into the long finger flexors.
All patients presented with minimal active finger extension with the wrist
flexed, sustained clonus of the finger flexors, functional proximal arm function,
and absence of fixed contracture. Cadaver dissections directed selection of two
injection sites: the flexor digitorum sublimis and the flexor digitorum
profundus. Fifty mouse units of botulinum toxin were injected into each muscle.
After injection, the subjects were instructed in a home program of stretching the
long finger flexors, upper limb weight bearing with a weight-bearing splint, and
exercise to improve finger extension control. RESULTS: Compared with preinjection
measures, assessment the first week after the initial injection showed
significantly reduced tone, reduced clonus, and greater active finger extension
with the wrist in the neutral position. Four months later, the Ashworth scale
increased to preinjection levels in the six subjects with repeated injections but
was again decreased postinjection. Active finger extension with the wrist in the
neutral position and clonus showed a statistically nonsignificant trend toward
cumulative improvement after the second injection. CONCLUSION: The greatest
change in finger extension and spasticity reduction occurred after the first
injection. Continued significant improvement in finger extension was not
observed.
PMID- 10678603
TI - Treatment of myofascial pain.
AB - OBJECTIVE: To investigate the effectiveness of ultrasound treatment and trigger
point injections in combination with neck-stretching exercises on myofascial
trigger points of the upper trapezius muscle. DESIGN: Depression and anxiety
associated with chronic pain were assessed using the Beck Depression Inventory
(BDI) and the Taylor Manifest Anxiety Scale (TMAS). The study population
comprised 102 patients who had myofascial trigger points in one side of the upper
trapezius. The patients were randomly assigned to one of three groups: group 1
received ultrasound therapy to trigger points in conjunction with neck-stretching
exercises; group 2 received trigger point injections and performed neck
stretching exercises; and group 3, the control group, performed neck-stretching
exercises only. Treatment effectiveness was assessed using subjective pain
intensity (PI) with a visual analog scale, pressure pain threshold (PT) with
algometry, and range of motion (with a goniometer) of the upper trapezius muscle.
RESULTS: Compared with the control group, patients in groups 1 and 2 had a
statistically significant reduction in PI, an increase in PT, and an increase in
range of motion. There were no statistically significant differences between
treatment groups 1 and 2. Although not statistically significant, patients in the
control group had better results at the 3-mo follow-up. The BDI scores indicated
depression in 22.9% of the patient, with 4.8% of the patients having severe
depression. High anxiety scores on the TMAS were present in 89.3% of the
patients. When BDI and TMAS scores were compared with PI or PT levels, no
significant correlations were found, but when compared with pain duration before
treatment, correlations were significant. CONCLUSIONS: Patients with myofascial
pain syndrome had higher scores for anxiety than for depression. When combined
with neck stretching exercises, ultrasound treatment and trigger point injections
were found to be equally effective.
PMID- 10678604
TI - Effects of botulinum toxin A on upper limb spasticity in children with cerebral
palsy.
AB - OBJECTIVE: Botulinum toxin A inhibits presynaptic release of acetylcholine at the
neuromuscular junction and has reportedly been successful in the treatment of
spastic disorders. This prospective study attempted to determine whether
botulinum toxin A injection resulted in clinically measurable gains for 4 mo.
DESIGN: Measurements were obtained from 32 children (range, 1-18 yr; average age,
6.9 yr) with hemiplegic or quadriplegic cerebral palsy before and at 1, 3, and 4
mo after botulinum toxin A injections. Spasticity was measured using the Modified
Ashworth Scale for 12 different joints. RESULTS: Results showed that spasticity
as measured by Ashworth scores for elbow and wrist extension clearly declined (P
< 0.02) by 1 mo after botulinum toxin A injection, and diminished spasticity
continued for 3-4 mo. Caregivers reported improvement in subjectively rated
management, appearance, and function. However, patient response to botulinum
toxin A injection was not predictable. Age had no significant relationship to
gains. CONCLUSIONS: Further research is needed on the use of botulinum toxin A to
diminish spasticity and improve function.
PMID- 10678606
TI - Dosing practices of physicians for anticoagulation with warfarin during inpatient
rehabilitation.
AB - OBJECTIVE: To determine the percentage of international normalized ratios (INRs)
maintained within the therapeutic range for patients receiving chronic
anticoagulation treatment with warfarin during inpatient rehabilitation. DESIGN:
A consecutive, 4-month, retrospective chart review of all patients receiving oral
anticoagulation treatment was conducted in a large academic rehabilitation
center. The percentage of INRs within and out of the therapeutic range, frequency
of blood samples, length of therapy, and warfarin dose prescribed by physicians
were calculated. A total of 181 patients receiving chronic anticoagulation
treatment were identified. A total of 3,709 blood samples were analyzed. In 74
patients, the primary physician recommended a therapeutic range (Group 1). In the
remaining 107 patients, no therapeutic range was specified, and a target INR
range of 2.0-3.0 was assumed (Group 2). RESULTS: In Group 1, the INRs were in the
recommended range in 38.2% of all blood samples. In Group 2, 37.6% of all blood
drawn was within an INR range of 2.0-3.0. Statistical analysis showed that no
better accuracy was obtained when the INR range was predefined by a physician
(Group 1) or assumed to be in the 2.0-3.0 range (Group 2; P = 0.839).
CONCLUSIONS: Despite frequent physician monitoring, this study demonstrates the
difficulty in maintaining INRs within therapeutic ranges for patients receiving
oral anticoagulation. An overall tendency for underdosing is observed.
Improvement is necessary, given the high morbidity and mortality associated with
insufficient anticoagulation in rehabilitation inpatients.
PMID- 10678605
TI - Effect of history and exam in predicting electrodiagnostic outcome among patients
with suspected lumbosacral radiculopathy.
AB - OBJECTIVE: To determine the extent to which the history and physical examination
predict the outcome of the electrodiagnostic (EDX) evaluation in patients with
suspected lumbosacral radiculopathy. DESIGN: Data for 170 subjects referred for
low-back and lower limb symptoms were prospectively collected at five EDX
laboratories. The sensitivity, specificity, positive and negative predictive
values, and odds ratios were determined for symptoms and neurologic signs.
RESULTS: Symptoms were not significantly associated with an EDX study or a
lumbosacral radiculopathy. The physical examination was better at predicting that
an EDX study would be abnormal in general than it was at predicting a lumbosacral
radiculopathy in particular. Of those subjects with normal physical examinations,
15%-18% still had abnormal EDX findings. CONCLUSIONS: In a population of patients
referred for an EDX study, the history and physical examination alone cannot
reliably predict electrodiagnostic outcome.
PMID- 10678607
TI - The future of physical medicine and rehabilitation.
PMID- 10678608
TI - The Uniform Data System for Medical Rehabilitation: report of first admissions
for 1998.
PMID- 10678609
TI - Heparin-induced hyperkalemia confirmed by drug rechallenge.
AB - Subcutaneous heparin is commonly used as a prophylaxis against deep venous
thrombosis in a wide variety of hospitalized patients. As with most medications,
heparin has a significant side effect profile; heparin-induced hyperkalemia is an
unusual but well described side effect. To increase awareness of heparin-induced
hyperkalemia and of those patients at greatest risk, we present two cases of
documented hyperkalemia induced by heparin and reconfirmed by drug rechallenge.
PMID- 10678610
TI - Improving the workers compensation system: case management perspective.
PMID- 10678611
TI - Rough sets: a knowledge discovery technique for multifactorial medical outcomes.
AB - Rough sets is a fairly new and promising technique for data mining and knowledge
discovery from databases. This tutorial article presents the fundamentals of
rough set theory in a nontechnical manner and outlines how the technique can be
used to extract minimal if-then rules from tables of empirical data that either
fully or approximately describe given example classifications. An example
application for prediction of ambulation for patients with spinal cord injury is
given. Because such rules are readily interpretable, they can be inspected to
yield possible new insight into how various contributing factors interact and,
thus, serve as hypothesis generators for further research. Additionally, the set
of mined rules may function as a classifier of new, unseen cases.
PMID- 10678612
TI - Starting inhaled corticosteroids in asthma: when, how high, and how long.
PMID- 10678613
TI - The lung in inflammatory bowel disease.
PMID- 10678614
TI - Low- and high-dose fluticasone propionate in asthma; effects during and after
treatment.
AB - The dose dependency of the effects of inhaled corticosteroids on markers of
asthmatic airway inflammation have not been well studied. There is a need to
study the dose/response effects on this inflammation. In order to determine the
dose/response effects of fluticasone propionate (FP), 24 asthmatic subjects were
randomized to low- (100 microg x day(-1)) or high-dose (1,000 microg x day(-1))
FP for six weeks followed by placebo for 3 weeks. During treatment, the median
increase in forced expiratory volume in one second (FEV1)was 12% in the high-dose
group (p<0.05) and 10% in the low-dose group (p<0.05) (p>0.05 between groups);
the median decrease in the percentage of sputum eosinophils was 93% in the high
dose group (p<0.05) and 46% in the low-dose group (p<0.05) (p>0.05 between
groups). Symptoms, salbutamol use, morning peak flow, provocative concentration
of methacholine causing a 20% fall in FEV1 (PC20), sputum eosinophil cationic
protein concentration and tryptase activity improved significantly in both groups
(p<0.05), but only the improvement in salbutamol use was greater in the high-dose
group (p<0.05). During the run-out, the improvements in FEV1 and PC20 were
rapidly reversed in both groups, but the improvements in peak flow and tryptase
activity persisted; the improvement in sputum eosinophil concentration persisted
only in the high-dose group (p<0.05). It was concluded that dose/response effects
for FP are not easily demonstrable because low-dose FP is quite effective. For
most outcomes, the effects of high- and low-dose FP are relatively short-lived
after treatment is stopped. This finding raises questions about the extent to
which inhaled corticosteroids are disease-modifying in asthma.
PMID- 10678615
TI - Effect of inhaled fluticasone propionate on airway responsiveness in treatment
naive individuals--a lesser benefit in females.
AB - A randomized double-blind placebo-controlled parallel group study with inhaled
fluticasone propionate over 6 weeks, designed to quantify the beneficial effect
on airway responsiveness, and so assess whether short pulses of intermittent
prophylactic treatment might serve as an alternative means of managing mild
asthma, is reported. The 20-50-yr-old participants, who were recruited from an
epidemiological study of the general population, had never knowingly received any
regular treatment for asthma. Fluticasone propionate at the maximum recommended
dose level (2,000 microg daily) and placebo were administered via metered-dose
inhalers, and airway responsiveness was quantified conventionally by the
provocative dose of methacholine causing a 20% fall in forced expiratory volume
in one second (FEV1) (PD20) at 2-week intervals during the treatment phase and at
various intervals subsequently. Compared with placebo fluticasone propionate was
associated with a highly significant decrease in airway responsiveness (1.9
doublings of the geometric mean PD20), which was maximal at the end of the 6-week
treatment period. No persisting benefit was detectable at the next measurement 2
weeks later, or thereafter. Multiple linear regression analysis showed that the
magnitude of the fluticasone propionate effect was significantly greater in males
than in females (3.2 versus 1.2 doublings respectively of the geometric mean
PD20), but was uninfluenced by current smoking, age or FEV1. In conclusion, in
the absence of any possibility of tachyphylaxis, inhaled fluticasone propionate
at this dose causes a steadily increasing improvement in airway responsiveness
over a 6-week period, which is modified by sex but lost almost immediately on
treatment cessation. Short pulses of intermittent prophylactic treatment would
not, therefore, be useful as a means of managing mild asthma.
PMID- 10678616
TI - Asthma management in five European countries: doctors' knowledge, attitudes and
prescribing behaviour. Drug Education Project (DEP) group.
AB - The aim of the study was to examine the relationship between guideline
recommendations on asthma management, and the performance of doctors in five
different European health care contexts. Knowledge, attitudes and prescribing
behaviour of doctors recruited to an educational project was investigated. A
total of 698 general practitioners from Germany, The Netherlands, Norway and
Sweden, and 94 specialists from the Slovak Republic participated. A questionnaire
was used to assess their knowledge and attitudes. Antiasthmatic drugs dispensed
to their patients reflected their prescribing behaviour. In response to questions
on how to treat chronic asthma, most doctors were in agreement with guideline
recommendations. In practice, however, the proportion of asthma patients
receiving inhaled steroids varied almost twofold, ranging 31% in Germany to 58%
in The Netherlands. On questions related to exacerbation of asthma, German and
Slovakian doctors often preferred treatment with antibiotics to steroids. They
also more often associated yellow-green sputum with bacterial infection. In
conclusion, although many doctors in different health care contexts have accepted
the recommendations given in guidelines, the proportion of their patients treated
accordingly differed. German and Slovakian doctors seem to attach less importance
to the inflammatory features of asthma than the doctors from the other three
European countries.
PMID- 10678618
TI - Neutrophils in induced sputum arise from central airways.
AB - A high neutrophil count is often found in induced sputum compared to
bronchoalveolar lavage fluid (BALF). This study investigated whether such a high
neutrophil count may be a response to inhaled hypertonic saline or that the
airway compartment sampled by induced sputum has a higher concentration of
neutrophils than BALF. Saliva and induced sputum samples were taken at 10 and 20
min following inhalation of 3% hypertonic saline from an ultrasonic nebulizer in
12 healthy nonsmoking subjects. Four days later the 12 subjects underwent
bronchoscopy (six following inhalation with 3% saline). Tracheal, proximal
bronchial secretions, bronchial washings and BALF samples were obtained. The
neutrophil count (% total leukocytes) increased significantly in saliva at 10 and
20 min post nebulization with 3% saline, although there was no change in
neutrophils in induced sputum at 10 and 20 min. There was no significant
difference in neutrophil count in the subjects who inhaled 3% saline as compared
to those who did not, in secretions from the trachea, proximal bronchi, bronchial
washings and BALF. Neutrophil counts were significantly higher in the trachea,
proximal bronchi and bronchial washings as compared to BALF (p<0.001). It is
concluded that neutrophil counts in healthy subjects increase from the peripheral
towards the proximal airways, in the absence of hypertonic saline-induced
changes. This suggests that the relatively high neutrophil count in induced
sputum arises from the proximal airways and is not a response to inhaled
hypertonic saline during the procedure.
PMID- 10678617
TI - Bronchial hyperresponsiveness and airway inflammation markers in nonasthmatics
with allergic rhinitis.
AB - Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma which
is often associated with airways inflammation. However, some patients with
allergic rhinitis and no clinical evidence of asthma also exhibit BHR. This study
therefore investigated whether inflammatory cell infiltrate is present in the
induced sputum of nonasthmatic subjects with allergic rhinitis during the pollen
season and examined its relationship with airway hyperresponsiveness to inhaled
methacholine and adenosine 5'-monophosphate (AMP). Twenty subjects (12 allergic
rhinitis, eight nonallergic controls) underwent methacholine and AMP challenge
and sputum induction with hypertonic saline on separate days. Cell differentials
were calculated from whole sputum samples. A significantly greater number of
eosinophils was found in the sputum of nonasthmatic subjects with allergic
rhinitis compared to that of nonallergic controls, their median (range)
percentages being 17.5 (4-47) and 1.5 (0-5) (p<0.001) respectively. Although
sputum eosinophilia failed to be significantly associated with methacholine
responsiveness (r(s)=-0.50; p=0.095), the provocative concentration of AMP
causing a 20% fall in forced expiratory volume in one second correlated strongly
and significantly with the absolute number of eosinophils (r(s)= -0.73; p=0.007).
Eosinophil cationic protein levels in the sputum of rhinitic subjects were
significantly elevated compared to controls and correlated with eosinophil number
(r(s)=0.67; p=0.017). These findings support the view that bronchial eosinophilia
alone is insufficient to cause asthmatic symptoms. Diverse agonists for assessing
bronchial hyperresponsiveness are selectively associated with airway inflammation
in allergic rhinitis.
PMID- 10678619
TI - Clinical and radiological characteristics of lung disease in inflammatory bowel
disease.
AB - The pulmonary associations of inflammatory bowel disease (IBD) are poorly
characterized. The clinical, physiological and high-resolution computed
tomographic thorax characteristics of the lung disease in patients with IBD
presenting with respiratory symptoms are described. Detailed clinical information
was obtained and standard pulmonary physiological tests and thorax high
resolution computed tomography performed on 14 patients with ulcerative colitis
(UC) and three with Crohn's disease (CD), 10 male, aged 38-83 yrs. Respiratory
symptoms had been present for 2-50 yrs and extraintestinal manifestations were
present in three (17.6%). Normal pulmonary physiology (six patients) was
associated with the high resolution computed tomographic changes of
bronchiectasis, mosaic perfusion and air trapping suggestive of obliterative
bronchiolitis and a pattern of centrilobular nodules and branching linear
opacities ("tree in bud" appearance) suggestive of either cellular bronchiolitis
or bronchiolectasis with mucoid secretions. Bronchiectasis was found in 13
patients (11 UC, 2 CD), 11 had air trapping and five had a "tree in bud"
appearance on computed tomography. One patient had a predominantly peripheral
reticular pattern at the lung bases similar to that found in cryptogenic
fibrosing alveolitis and one patient had a mixed reticular and ground-glass
pattern in the midzones with a patchy distribution in the central and peripheral
portions of the lungs with air trapping. Eleven patients (three with alveolitis)
exhibited a clinical and/or physiological response to steroids. Pulmonary
abnormalities in ulcerative colitis and Crohn's disease can present years after
the onset of the bowel disease and can affect any part of the lungs. Early
recognition is important as they can be strikingly steroid-responsive.
PMID- 10678620
TI - B7-1, B7-2 and class II MHC molecules in idiopathic pulmonary fibrosis and
bronchiolitis obliterans-organizing pneumonia.
AB - Interstitial lung diseases are thought to be associated with the infiltration of
activated T-lymphocytes. To induce an effective immune response, antigen
presenting cells have to not only present antigenic peptide with major
histocompatibility complex (MHC) molecules to T-lymphocytes but also express B7
molecules. Therefore, the expression of B7-1, B7-2 and class II MHC molecules was
investigated in lung tissues from patients with idiopathic pulmonary fibrosis
(IPF) and bronchiolitis obliterans-organizing pneumonia (BOOP), and in normal
lung parenchyma as a control, using immunohistochemical localization. B7-1 and B7
2 were aberrantly expressed in bronchiolar and alveolar epithelial cells, and
class II MHC molecules were also aberrantly expressed in bronchiolar epithelial
cells in IPF. B7-1 was aberrantly expressed in bronchiolar epithelial cells in
BOOP. There was no significant difference in the expression of these proteins in
alveolar macrophages between IPF and control subjects. However, B7-2 and class II
MHC molecule expression in alveolar macrophages was decreased in BOOP compared
with that in control subjects. Expression of CD28 and CTLA4, receptors for B7
molecules, was detected in infiltrating lymphocytes in lung tissues in IPF and
BOOP. It was concluded that bronchiolar and alveolar epithelial cells may
actively participate in the pathophysiology of idiopathic pulmonary fibrosis
through the aberrant expression of B7 and class II major histocompatibility
complex molecules. The dysregulation of these molecules in epithelial cells may
lead to the activation of autoreactive T-lymphocytes, which might contribute to
the pathogenesis of fibrosing lung diseases.
PMID- 10678621
TI - Pulmonary function and complications following chemotherapy and stem cell support
in breast cancer.
AB - Pulmonary complications are frequent in patients treated with high-dose
chemotherapy and autologous bone marrow transplantation for breast cancer or
other solid tumours. This study analyses the development of lung toxicity,
changes in respiratory function and occurrence of clinical symptoms in a group of
24 patients (mean age 46+/-7 yrs) who underwent high-dose sequential chemotherapy
(HDS) with autologous peripheral blood stem cell (PBSC) support for high risk
breast cancer. Clinical examination, chest radiography and lung function tests
were performed before the HDS and 1 and 3 months following transplantation. Only
one patient developed acute interstitial pulmonary disease which resolved after
prednisone therapy. No patients developed infectious complications after
transplantation. Baseline respiratory function was normal for most of the
parameters. Only lung diffusing capacity of the lung for carbon monoxide (TL,CO)
and maximal inspiratory pressure were below the normal range. Following PBSC
transplantation only one patient had an altered vital capacity while 72.3% of
patients had reduced TL,CO values at 1 month and 54.5% at 3 months after
transplantation. Maximal expiratory flow at 25% forced vital capacity, TL,CO and
maximal expiratory pres-sure were significantly reduced after 1 month but
recovered slightly by 3 months. Arterial oxygen tension between baseline and both
follow-up evaluations declined significantly in patients seropositive for human
cytomegalovirus. It is concluded that this high-dose sequential chemotherapy
regimen is acceptably safe since no pulmonary related mortality or respiratory
infectious complications were observed. The only lung function alteration induced
was an isolated diffusing capacity of the lung for carbon monoxide impairment,
clinically negligible and partially recovered within 3 months.
PMID- 10678622
TI - Macrolide antibiotics inhibit nitric oxide generation by rat pulmonary alveolar
macrophages.
AB - There is evidence that macrolide antibiotics are effective in the treatment of
chronic airway inflammatory diseases, probably through actions other than their
antibacterial properties. In order to determine whether macrolides affect the
nitric oxide-generating system in the respiratory tract, rat pulmonary alveolar
macrophages (PAMs) were studied in vitro. The release of NO was assessed by
direct measurement with a specific amperometric sensor for this molecule, and the
expression of type II NO synthase (NOS) messenger ribonucleic acid (mRNA) was
determined by Northern blotting. Incubation of PAMs with lipopolysaccharide from
Escherichia coli and recombinant human interferon-gamma caused release of NO,
which was accompanied by induction of type II NOS mRNA. The release of NO was
reduced by coincubation of cells with the macrolides erythromycin, clarithromycin
and josamycin in a concentration-dependent manner, the maximal inhibition being
73+/-10, 81+/-6 and 84+/-9%, respectively, but was not altered by amoxycillin or
cefaclor. These macrolides likewise inhibited the induction of type II NOS mRNA,
whereas no inhibitory effects were observed with amoxycillin or cefaclor. These
results suggest that macrolide antibiotics specifically inhibit type II NO
synthase gene expression and consequently reduce NO production by rat pulmonary
alveolar macrophages, which might result in attenuation of airway inflammation.
PMID- 10678623
TI - Budesonide and formoterol inhibit ICAM-1 and VCAM-1 expression of human lung
fibroblasts.
AB - The glucocorticoid budesonide and the long-acting beta2-adrenoceptor agonist
formoterol are used in asthma therapy for their anti-inflammatory and
bronchodilating effects, respectively. Since expression of adhesion molecules on
resident cells in the lung plays an important role in asthmatic inflammatory
responses, the effects of these drugs on the cytokine-induced intercellular
adhesion molecule-1 (ICAM)-1 and vascular cell adhesion molecule-1 (VCAM)-1
expression of human lung fibroblasts were investigated. Budesonide and formoterol
were added in the absence or presence of interleukin (IL)-1beta, tumour necrosis
factor-alpha (TNF-alpha), interferon gamma (IFN-gamma) or IL-4 to human lung
fibroblasts; ICAM-1 and VCAM-1 expression were measured after 8 h using a cell
surface enzyme linked immunosorbent assay (ELISA). It was found that both
budesonide and formoterol significantly inhibited (p<0.05) the increased
expression of ICAM-1 and VCAM-1 after stimulation with IL-1beta (maximal
inhibition (median (25-75% percentiles) 50 (48-52) and 61% (42-69), respectively,
with budesonide and 55 (50-73) and 86% (64-94), respectively, with formoterol
(10(-7) M)), TNF-alpha (maximal inhibition 49 (46-57) and 57% (44-68),
respectively, with budesonide and 44 (40-75) and 62% (52-83) respectively, with
formoterol), IFN-gamma (maximal inhibition 64% (41-67) with budesonide and 39%
(29-49) with formoterol for ICAM-1) and IL-4 (maximal inhibition 82% (69-92) with
budesonide and 43% (33-67) with formoterol for VCAM-1) in a dose-dependent
manner. The results show that budesonide, as well as formoterol, in probably
clinically relevant concentrations inhibits cytokine-induced adhesion molecule
expression on human lung fibroblasts from a concentration of 10(-9) M. This
inhibitory effect on resident cells may have implications for the infiltration of
inflammatory cells into pulmonary tissue during therapy with these drugs in
asthma.
PMID- 10678624
TI - Leukotoxin and its diol induce neutrophil chemotaxis through signal transduction
different from that of fMLP.
AB - When injected into animals, leukotoxin (Lx) causes acute lung injury which is
associated with neutrophils infiltrating the lung tissues. However, the effect of
Lx on neutrophils is still unknown, and recently it has been reported that Lx
diol, a hydrolyzed metabolite, should be more potent than Lx in vitro. In this
study, the authors examined the effect of Lx and its diol on human neutrophils by
assessing their chemotactic response, expression of adhesion molecules, and
production of peroxides. Both Lx and its diol induced chemotaxis in human
neutrophils via an involvement of pertussis toxin-sensitive G-proteins, but they
did not influence the expression of adhesion molecules or the production of
peroxides. Furthermore, Lx synergistically affected chemotaxis with N-formyl
methionyl-leucyl-phenylalanine (fMLP), but not with endothelin-1. Neutrophil
chemotaxis induced by both Lx and its diol was inhibited by phosphatidylinositol
3-kinase (PI3-K) inhibitors, but not by protein tyrosine kinase (PTK) inhibitors
or by protein kinase C (PKC) inhibitors, whereas fMLP-induced chemotaxis was
inhibited by PTK inhibitors, but not by PI3-K inhibitors or by PKC inhibitors.
These results suggest that neutrophil chemotaxis induced by both Lx and its diol
involves pathways different from those induced by fMLP. In conclusion, both
leukotoxin and its diol metabolite induce chemotaxis in human neutrophils in a
unique way and may act as important bioactive lipids when considering the
pathological mechanism of acute lung injury.
PMID- 10678625
TI - Effects of aging on surfactant forms in rats.
AB - Surfactant present in the alveolar space exists in two major forms: functional
large aggregate forms (LA) and nonfunctional small aggregate forms (SA), but
there is no information about the changes of surfactant forms and the rate of
conversion of LA to SA in the aged lungs. The purpose of the present study was to
investigate the developmental aspects of surfactant forms in newborn, young,
middle-aged and aged rats, LA and SA were recovered from alveolar lavages of
rats. The rate of conversion from LA to SA was then analysed using a surface-area
cycling technique. Age-related changes of saturated phosphatidylcholine (Sat-PC)
and surfactant protein A (SP-A) pool sizes were also evaluated in alveolar
lavages. The alveolar lavages recovered from aged rats contained a significantly
higher proportion of LA than did those obtained from young or newborn rats. There
was also an age-related decrease in the rate of conversion from LA to SA in
vitro. The Sat-PC pool sizes in the alveolar lavages decreased with age, but the
SP-A contents were similar between young and aged rats. These results suggested
that decreased form conversion may contribute to maintaining functional
surfactant pool sizes in the lungs of aged rats.
PMID- 10678626
TI - Respiratory effects of lipopolysaccharide-induced inflammatory lung injury in
mice.
AB - The pathogenic mechanisms of lipopolysaccharide (LPS)-induced lung injury have
not been classified. This study examined the physiological changes after
endotoxin inhalation and related those to features of pulmonary inflammation in
mice. Pulmonary mechanics, histopathology, and bronchoalveolar lavage fluid
(BALF) from BALB/c mice were analysed at different occasions (3, 24, 48 and 72 h)
after inhalation of saline or LPS from Escherichia coli (0.3 (L0.3) or 10 mg x
mL(-1) (L10)). Mice were sedated, anaesthetized, and ventilated. After chest wall
resection static (Est) and dynamic (Edyn) elastances, deltaE (Edyn-Est),
resistive (deltaP1) and viscoelastic/inhomogeneous pressures (deltaP2), and
deltaP1+deltaP2 (deltaPtot) were obtained by end-inflation occlusion method.
Lungs were prepared for histopathology. In parallel groups, tumour necrosis
factor (TNF)-alpha, neutrophils, and protein were evaluated in the BALF. L0.3 and
L10 showed a time-dependent production of TNF-alpha preceding a massive
neutrophil infiltration. In L10 BALF there was an increase in protein level at 24
and 48 h. Est and Edyn increased early in L0.3 (65%, 63%) and L10 (41%, 51%). In
L10 deltaE, deltaP2, and deltaPtot showed a gradual rise. At 72 h all groups were
similar. L0.3 showed an early increase in cellularity, which returned to normal
at 72 h. L10 presented the same pattern with the cell count remaining elevated
until 72 h. In conclusion, lipopolysaccharide inhalation led to elastic and
viscoelastic pulmonary changes together with tumour necrosis factor-alpha
production and neutrophil infiltration in mouse lung.
PMID- 10678627
TI - Skeletal muscle strength and endurance in patients with mild COPD and the effects
of weight training.
AB - This study poses two questions: 1) is there an abnormality in isokinetic skeletal
muscle strength and endurance in mild chronic obstructive pulmonary disease
(COPD)? and 2) what is the effect of a randomized, controlled, 12 week hospital
outpatient weight training programme in terms of skeletal muscle function and
exercise tolerance? Upper and lower limb isokinetic maximum and sustained muscle
function were compared in 43 COPD patients (age 49+/-11 yrs), mean forced
expiratory volume in one second (FEV1) 77+/-23% pred and 52 healthy, sedentary
subjects (age 51 (10) yrs), mean FEV1 109+/-16% pred. The 43 COPD patients were
randomly allocated into training (n=26) and control (n=17) groups. Isokinetic and
isotonic muscle function, whole body endurance, maximal exercise capacity and
lung function were measured. The COPD patients had reduced isokinetic muscle
function (with the exception of sustained upper limb strength) as compared with
healthy sedentary subjects. Muscle function improved after weight training in the
COPD patients. Whole body endurance during treadmill walking also improved with
no change in maximal oxygen consumption. A deficit in skeletal muscle function
can be identified in patients with mild chronic obstructive pulmonary disease
which cannot be explained by factors such as hypoxaemia and malnutrition.
Intervention with weight training is effective in countering this deficit which
the authors conclude is probably due to muscle deconditioning.
PMID- 10678628
TI - Nasal ventilation in COPD exacerbations: early and late results of a prospective,
controlled study.
AB - Noninvasive positive pressure mechanical ventilation (NIPPV) in exacerbated
chronic obstructive pulmonary disease (COPD) has been investigated early and
after 1 yr of follow-up. To this end, 30 patients were enrolled in a prospective,
controlled trial: 15 had early administration of NIPPV (Group A), 15 had medical
therapy only (Group B); assignment was made on the basis of equipment
availability only. In-hospital mortality, need for endotracheal intubation and
mean length of hospitalization were lower in Group A, though the difference was
not statistically significant. Arterial oxygen tension in arterial blood (Pa,O2),
carbon dioxide tension in arterial blood (Pa,CO2) and HCO3- improved
significantly in both groups from admission to discharge: 45.8+/-8.6 versus
64.9+/-10.0; 59.4+/-11.8 versus 48.6+/-7.3; 34.3+/-4.3 versus 30.1+/-3.4 in group
A; 49.2+/-11.4 versus 60.9+/-8.2; 52.6+/-15.9 versus 44.4+/-8.7; 31.7+/-5.9
versus 28.0+/-3.6 in group B, respectively, p<0.05 for all comparisons; pH,
percentage forced expiratory volume in one second (FEV1) and tidal volume (VT)
improved significantly in patients of group A only: 7.36+/-0.04 versus 7.41+/
0.02; 39.8+/-13.6 versus 49.4+/-11.7; 0.71+/-0.3 versus 0.84+/-0.4, respectively,
p<0.05. During follow-up, 3, 6, and 12 months survival rates were significantly
higher in Group A than in Group B (p<0.02). Hospital new admissions over 1 yr
were more frequent in Group B (n=6, incidence rate: 0.216%) than in Group A (n=4,
incidence rate: 0.084%). Therefore, noninvasive positive pressure mechanical
ventilation may be added to "conventional" medical therapy in exacerbated chronic
obstructive pulmonary disease.
PMID- 10678629
TI - Peripheral airway findings in chronic obstructive pulmonary disease using an
ultrathin bronchoscope.
AB - The authors performed bronchoscopic examination using an ultrathin bronchoscope
to determine the characteristics of the peripheral airways in chronic obstructive
pulmonary disease (COPD). The study population comprised 13 healthy control
subjects, 10 patients with chronic bronchitis without airflow limitation, and 20
patients with COPD. The COPD patients were divided clinically into 10 with
chronic bronchitis and 10 with pulmonary emphysema. The peripheral airways were
examined using an ultrathin bronchoscope. In chronic bronchitis, peripheral
airways of the 11th or 12th generation showed a high frequency of obstruction and
mucosal changes such as granulation. In pulmonary emphysema, the peripheral
airways frequently showed a net-like appearance of the bronchial epithelium and
obstruction at the 11th or 12th generation. Morphological changes of the small
airways in chronic obstructive pulmonary disease can be detected by an ultrathin
bronchoscope, and this method is likely to be useful for investigating the small
airways in vivo.
PMID- 10678630
TI - Comparison of induced sputum with bronchial wash, bronchoalveolar lavage and
bronchial biopsies in COPD.
AB - It is unclear how cellular and soluble inflammatory markers in induced sputum
relate to markers in lavage fluid and biopsies in chronic obstructive pulmonary
disease (COPD). This was investigated and also the possible differences between
subjects with COPD and healthy controls assessed. Eighteen nonatopic subjects
with COPD and 11 healthy controls were studied. Sputum was induced by inhalation
of hypertonic saline. The airways were lavaged, using the first 50 mL for
bronchial wash (BW) and the subsequent 150 mL for bronchoalveolar lavage (BAL),
and biopsies were taken from subsegmental carinae. Neutrophils were the
predominant cell type in sputum in COPD (median 77.3%) but not in BW (5.5%) and
BAL fluid (1.7%). Differential cell counts in sputum did not correlate with the
counts in BW or BAL fluid or biopsies, whereas sputum eosinophil cationic protein
(ECP) levels correlated with BW fluid ECP levels (p=0.66, p=0.007) and sputum
interleukin-8 (IL-8) concentration with BAL fluid IL-8 concentration (p= 0.52,
p=0.026). Subjects with COPD had a higher percentage of sputum neutrophils and
eosinophils and higher concentrations of ECP and IL-8 than healthy controls. The
higher percentages of eosinophils and concentrations of ECP were also seen in BW
and BAL fluid. Finally, higher numbers of macrophages and eosinophils were found
in biopsies. In conclusion, induced sputum is derived from a different
compartment from BW and BAL fluid and biopsies. Induced sputum may be useful for
studying the contribution of luminal neutrophils and eosinophils in chronic
obstructive pulmonary disease.
PMID- 10678631
TI - Venous and arterial changes in pulmonary veno-occlusive disease, mitral stenosis
and fibrosing mediastinitis.
AB - The pathogenesis of pulmonary veno-occlusive disease (PVOD) is not known. The
diagnosis of PVOD frequently relies on its histological changes since it is often
difficult to distinguish clinically from primary pulmonary hypertension. This
study carried out a systematic analysis of the pulmonary venous and arterial
remodelling that occurs in PVOD (n=5) and compared these changes to two other
diseases affecting the pulmonary veins, mitral stenosis (MS; n=6) and fibrosing
mediastinitis (FM; n=2), using established morphometric techniques. In PVOD,
pronounced intimal and adventitial thickening were noted in veins of all sizes
and arterialization of veins >50 microm external diameter was found. Similar
changes were evident in the arterial wall, but intimal thickening was less severe
than in the veins and medial thickening was more pronounced in arteries <300
microm external diameter. Eccentric intimal fibrosis of the veins was also noted
for the first time in PVOD, although this feature occurred less frequently
(approximately one third) than in MS. Less pronounced structural remodelling was
also encountered in the veins in cases of MS and FM. The severity of the venous
changes in PVOD may aid its diagnosis and lend insight into its pathogenesis.
However, the similarity of the vascular changes in each form of venous
hypertension also suggests that pathology alone may not always differentiate
between these disease states. The similarity of the vascular changes in the three
forms of venous hypertension suggests that, as in pulmonary artery hypertension,
pressure, per se, is one of the triggers to vascular remodelling.
PMID- 10678632
TI - Theophylline improves acute mountain sickness.
AB - A randomized two-part study was conducted in order to determine the efficacy of
theophylline in the treatment of acute mountain sickness during fast ascent to
altitudes >2,500 m. Fourteen healthy male subjects participated in a randomized
single-blind placebo-controlled crossover study carried out in a decompression
chamber (simulated altitude 4,500 m). A second randomized single-blind, placebo
controlled study was conducted at a high-altitude research laboratory (3,454 m)
and included 21 healthy male subjects. The study medication was either 375 mg
oral slow-release theophylline (250 mg if <70 kg) or a matched placebo tablet
taken twice daily. The acute mountain sickness score (AMSS) was assessed three
times a day, beginning 18 h prior to altitude exposure and continuing for 18 h
after altitude exposure. In addition, measurements of respiratory frequency,
pulse rate, oxygen saturation and arterial blood gas levels were performed. Acute
mountain sickness was significantly reduced by theophylline during the
decompression chamber study (mean+/-SD 1.2+/-0.9) with placebo versus 3.6+/-0.8
with theophylline; p=0.03). During the high-altitude study, subjects with
theophylline showed a significantly lower AMSS on arrival and after 18 h at
altitude (0.6 versus 2.3, p=0.03). Oxygenation was improved in both parts of the
study. In conclusion, oral slow-release theophylline improves acute mountain
sickness.
PMID- 10678633
TI - Assessing the risk of hypoxia in flight: the need for more rational guidelines.
AB - This study aimed to test the hypothesis that advice currently given by
respiratory physicians to potentially hypoxic patients planning air travel varies
and is not evidence-based. A prospective observational study was performed,
surveying respiratory physicians in England and Wales. Sixty-two per cent
responded. Nearly two-thirds worked in district general hospitals, a quarter in
university hospitals, and the rest in tertiary referral (specialist) centres or a
combination thereof. Most provide advice routinely; most of the remainder do on
request or if concerned. Assessments comprise spirometry, blood gas level
measurement, oximetry, predictive equations and hypoxic challenge tests. Twenty
five per cent of physicians measuring blood gas levels recommend in-flight oxygen
when arterial oxygen tension (Pa,O2) <7.3 kPa, 50% when Pa,O2 is 7.3-8.0 kPa.
Over two-thirds using spirometry recommend oxygen when the forced expiratory
volume in one second <40% of the predicted value. Half recommend oxygen when
arterial oxygen saturation (Sa,O2) <90%, 33% when Sa,O2 is 90-94%. Fewer than 10%
of district hospital physicians (and none in other hospitals) use predictive
equations. More than half of specialists but fewer than 10% of district hospital
physicians perform hypoxic challenge tests. The risk of hypoxia at altitude is
recognized by most respiratory physicians in England and Wales, but assessment
methods and criteria for recommending oxygen vary widely. This suggests that most
current advice is not evidence-based. Evidence-based guidelines are required.
PMID- 10678634
TI - Clinically "small" effects of air pollution on FVC have a large public health
impact. Swiss Study on Air Pollution and Lung Disease in Adults (SAPALDIA) -
team.
AB - Epidemiological studies have repeatedly established adverse health effects due to
long-term exposure to ambient air pollution. The Swiss Study on Air Pollution and
Lung Disease in Adults (SAPALDIA) published a -3.14% decrease in forced vital
capacity (FVC) per 10 microg x m(-3) increment in particulate matter (particles
with a 50% cut-off aerodynamic diameter of 10 microm (PM(10)). Compared to the
within-subject variability of FVC, the effect may be considered small. This
individual (or clinical) perspective is, however, misleading. The purpose of this
study was to demonstrate the public health relevance of apparently "small"
effects, using the impact of PM10 on FVC as an example. The scenario compares a
population A, exposed to an annual mean PM10 of 20 microg x m(-3), with a
population B exposed to 30 microg x m(-3) mean PM10. A shift of -3.14% in the
population distribution of FVC increases the number of subjects in the lower tail
of the distribution. In population B a relative increase was expected of 47% (16
91%) in the prevalence of "FVC <80% predicted", (i.e., from 5.17 to 7.59% and
5.88 to 8.65% among males and females, respectively). The relative increase in
the prevalence of "FVC <70% predicted" (approximately 1% of population) was 63%
(30-98%, males) and 57% (21-86%, females). An epidemiological estimate of a
change in the mean value of the population distribution should not be
misinterpreted as an effect on the individual level. However, the impact of a 10
microg x m(-3) increase in particles with a 50% cut-off aerodynamic diameter of
10 microm (PM10) on the number of subjects with a clinically relevant reduction
in lung function is quantitatively important.
PMID- 10678635
TI - Impact of correcting peak flow for nonlinear errors on air pollutant effect
estimates from a panel study.
AB - Air pollutant effects are commonly investigated using panel studies employing
daily measurement of changes in peak expiratory flow (PEF). Variable orifice PEF
meters are inaccurate with a nonlinear relationship to actual PEF. The impact on
a panel study of correcting these errors was examined. Twice-daily PEF readings
were taken by 147 9-yr old children for 8 weeks and corrected using an equation
derived from the response of 32 Vitalograph meters to a servomechanism-controlled
pump. Pollutant effect estimates for corrected and uncorrected readings were
derived using a regression approach incorporating appropriate confounders.
Correction impacted little on mean PEF values (333.1-334.2 L x min(-1)), but did
alter effect sizes. Nonsignificant nitrogen dioxide estimates for the entire
panel decreased by up to 73%, but, for symptomatic/atopic children, a significant
5-day mean result was lost (decrease in effect size from -2.53 to -0.90% per 10
parts per billion (ppb)) and lag 0 became significant (decrease from -0.51 to
1.22% per 10 ppb). Mass concentration estimates of particles with a 50% cut-off
aerodynamic diameter of 2.5 microm moved in both directions (-0.22 changed to
0.11% per 10 microg x m(-1) lag 3 and -0.29 to -0.73% per 10 microg x m(-3) for
the 5-day mean). Correction of nonlinearity of peak expiratory flow meters
influenced the overall outcome of this panel study, and the changes in effect
estimates would be sufficient to alter the interpretation of some studies. For
adults, a greater change in effect estimates may follow the larger correction
required for their usual peak expiratory flow range.
PMID- 10678636
TI - Fractional analysis of bronchoalveolar lavage fluid cytology in cystic fibrosis
patients with normal lung function. Bronchoalveolar lavage for the evaluation of
anti-inflammatory treatment (BEAT) study group.
AB - Cystic fibrosis (CF) is associated with a neutrophil dominated airway
inflammation. So far bronchoalveolar lavage (BAL) studies in CF have used pooled
BAL samples which may be more representative of the alveolar compartment rather
than the airways. To assess whether the first sample of a BAL is more sensitive
in the evaluation of airway inflammation, the authors have studied 105 stable CF
patients aged 5-37 yrs with a mean forced expiratory volume in one second (FEV1)
of 96+/-15% (mean+/-SD). BAL cytology of the first and pooled samples were
compared to reference values obtained in children without respiratory disease.
Absolute cell counts and the percentage of neutrophils were significantly
increased in CF patients. If the 95% confidence interval was used as a cut-off
point, 17/105 CF patients had a normal percentage of neutrophils in pooled BAL
samples, but only three also had a normal percentage of neutrophils in the first
BAL aliquot. Therefore, neutrophil dominated airway inflammation is more
pronounced in the first, mainly bronchial, bronchoalveolar lavage sample
suggesting that sequential analysis of bronchoalveolar lavage fluid may have a
higher sensitivity to detect early inflammatory changes in CF patients.
PMID- 10678637
TI - Sodium channel blockers and uridine triphosphate: effects on nasal potential
difference in cystic fibrosis mice.
AB - Sodium channel inhibitors block the enhanced Na+ reabsorption in cystic fibrosis
(CF). Extracellular nucleotides facilitate Cl- secretion via Ca2+ gated Cl-
channels. A combination of these effects may produce less viscid secretions in CF
which are easier to expectorate. This study examined the effects of combining
sodium channel blockers with uridine triphosphate (UTP) on nasal membrane
potential difference (PD) in CF insertional null mutant mice (cftr(tm1HGU)),
deltaF508 homozygous mice (cftr(tm1Cam)) and matched control animals. Median
basal PD in the insertional CF mice and deltaF508 CF mice were -28 and -34 mV
respectively. These values were significantly different to the control animals (
20 mV). Amiloride and loperamide reduced the PD in cftr(tm1HGU) CF mice (deltaPD
13 mV & 15 mV respectively) suggesting Na+ blockade. The subsequent addition of
UTP in a chloride-free vehicle increased the PD (deltaPD -8- -12.5 mV). DeltaF508
mice showed significantly greater responses compared with CF insertional null
mutant mice (p<0.05). The action of UTP was brief and not prolonged by the
addition alpha-beta-methylene-adenosine 5' diphosphate. Suramin, a competitive
antagonist of P2 purinoceptors blocked the action of UTP. In conclusion, this
study demonstrated dose dependant nasal membrane potential changes in differences
mice with uridine triphosphate in the presence of sodium channel blockers
suggestive of chloride secretion. More stable analogues of uridine triphosphate
in combination with long acting sodium channel blockers such as loperamide may
have therapeutic potential in cystic fibrosis.
PMID- 10678638
TI - The association between early life lung function and wheezing during the first 2
yrs of life.
AB - Reports have suggested that certain infants are predisposed to wheezing in the
first 2 yrs of life due to abnormal lung function, prior to the first wheezing
illness. The authors investigated the association between infant lung function
and wheeze during the first 2 yrs of life. A cohort of 253 infants was evaluated.
Respiratory function assessment was performed at 1, 6, and 12 months of age.
Parental history of asthma, atopy, and maternal antenatal smoking habits were
recorded. An infant was identified as having wheezed on the basis of parental
report and, where possible, physician diagnosis. One hundred and sixty infants
(63%) had complete diary and questionnaire information on wheeze available for
analysis. Of these: 79 infants (50%) had never wheezed (NW) during the first 2
yrs of life and 81 had reported wheeze (W) (50%). Of those with a report of
wheeze, the distribution through the first 2 yrs of life was; 28 during the first
year of life only (Y1), 21 in the second year of life only (Y2), and 32 wheezed
in both the first and second years of life (Y1&2). At the age of 1 month, prior
to any lower respiratory illness, the W group had impaired lung function in
comparison to the NW group. In Y1 infants, the neonatal lung function differences
resolved by 12 months of age. In Y2 and Y1&2 infants lung function differences
persisted throughout the first year of life. Prevalence of parental asthma and
maternal antenatal smoking was increased in the W group p=0.001, p=0.008,
respectively), in comparison to the NW infants. Maternal antenatal smoking
prevalence was increased in the Y2 and Y1&2 infants in comparison to the NW group
(p=0.04), (p=0.01), respectively. Wheezing during the first year of life is often
a transient condition which improves with time. It appears to be related to early
life reduced small airway calibre. Wheezing that begins or persists into the
second year of life is usually associated with a different abnormality of the
airways. Commencement or persistence of wheeze into the second year of life may
be part of the clinical entity recognized as asthma.
PMID- 10678639
TI - Maturational changes of endothelial vasoactive factors and pulmonary vascular
tone at birth.
AB - The aim of this study was to determine which endothelial factors were involved in
the decrease of pulmonary vascular resistance at birth, and how they changed with
maturation. Response of intrapulmonary artery rings precontracted with
prostaglandin F2alpha were studied from piglets aged <2 h, 2-3 day, 10 day and
adult pigs for pharmacological responses to acetylcholine (ACh) and cromakalim
(CMK) in the presence and the absence of the nitric oxide synthase (NOS)
inhibitor, N(omega)-nitro-L-arginine (L-NA), the adenosine triphosphate sensitive
potassium (K(ATP)) channel blocker, glibenclamide and the endothelin (ET)-A
receptor antagonist, BQ123. In situ hybridization and immunochemistry studies
were performed in lung tissues of the same animals in order to determine the
expression of NOS and ET. There was a small contractile effect of ACh in the
newborn. Relaxation to ACh, which was blocked by L-NA and reduced by
glibenclamide, only appeared from the age of 3 days. The significantly greater
relaxation to CMK in rings without endothelium (p<0.05) was abolished by BQ123 in
the newborn, and then disappeared by 2 days of age. Glibenclamide had a greater
inhibitory effect on relaxation induced by CMK at 10 days than in the newborn and
2 days old piglets. NOS expression was low in pulmonary arteries of the newborn
and increased by 2 days of age whereas the converse was seen with ET expression.
It is concluded that: 1) relaxant response to acetylcholine was absent at birth
and appeared at 2 days; 2) the reduced relaxant response to cromakalin in rings
with endothelium at birth could be blocked by BQ123; and 3) the expression of
endothelin decreased whereas the expression of nitric oxide synthase increased
from birth to 2 days of age.
PMID- 10678640
TI - Diagnostic utility of eosinophils in the pleural fluid.
AB - This study was conducted to assess the prevalence of eosinophilia in 358
consecutive samples of pleural fluid (all cases corresponded to first
thoracentesis), to review the cause of eosinophilic pleural effusions, and to
determine whether the presence of eosinophils increases the likelihood of
nonmalignant underlying disorders. Eosinophilic pleural effusions were identified
in 45 patients (12.6%): malignant underlying conditions were diagnosed in 11
patients (24.4% with eosinophilic effusions) and benign aetiologies were found in
27 patients. Benign aetiologies included uncomplicated paraneumonic effusion in
10 patients, tuberculosis in seven, complicated paraneumonic in five, liver
cirrhosis in three, hydronephrosis in one and pulmonary thromboembolism in one.
Seven pleural effusions were idiopathic. There was no difference in the
prevalence between eosinophilic and noneosinophilic effusions according to the
different diagnoses. With parameters of sensitivity, specificity, pretest and
post-test probability and positive and negative predictive values for any
prevalence figure using the Bayes' theorem and for any value of eosinophils (both
in percentage or absolute numbers) in the pleural fluid (receiver operating
characteristic curve) an adequate predictor of benign disease was not found. It
is concluded that pleural eosinophilia at the initial thoracentesis cannot be
considered as a predictor of an underlying benign disorder.
PMID- 10678641
TI - Release of endothelins and platelet-activating factor by a rat pleural
mesothelial cell line.
AB - Thrombin is a multifunctional serine protease. It is generated in inflammatory
processes and induces the proliferation and chemotaxis of a variety of cells
including mesothelial cells (MTCs). MTCs are epithelial cells derived from the
mesoderm, as are the vascular endothelial cells. Since thrombin acts on
endothelial cells to produce platelet-activating factor (PAF) and endothelin (ET)
1, it was hypothesized that MTCs also produce PAF and ET via the action of
thrombin. Rat pleural MTC (RMTC, 4/4 R.M.-4) monolayers were cultural in tissue
culture dishes for various periods. The supernatants were fractionated by means
of high-performance liquid chromatography to determine the ET isoforms and PAF
species present. Immunoreactive ET was measured using an enzyme-linked
immunosorbent assay, and PAF was measured by means of a bioassay using a platelet
aggregometer. ET-1, ET-2 and ET-3 were detected in RMTC-conditioned medium, and
the predominant isoforms were ET-1 and ET-2. RMTCs mainly released C16:0 PAF into
the supernatant. Immunoreactive ET and PAF were released via the action of
thrombin. Synthetic PAF significantly induced secretion of ET, but the PAF
receptor antagonists, WEB2086 and E6123, failed to modulate thrombin-induced ET
release. These results indicate that thrombin acts on pleural rat mesothelial
cells to release ET and PAF, which may play a role in the development of
pleurisy.
PMID- 10678642
TI - The measurement of exhaled carbon monoxide is influenced by airflow obstruction.
AB - The concentration of carboxyhaemoglobin (COHb) is often estimated from
measurements of carbon monoxide in the exhaled air (COexh). This study
investigates whether the presence of airflow obstruction significantly alters the
relationship between COexh and COHb. Eighty-one regular smokers were
prospectively studied and divided in four groups according to the presence and
severity of airflow obstruction (none, mild, moderate, severe). In each subject,
the authors measured in this order: 1) arterial blood gases; 2) haemoglobin
concentration and COHb (by co-oxymetry); 3) COexh; 4) lung volumes; and 5) forced
spirometry. The size of the measurement error (deltaCO) was calculated from the
difference between COHb and COexh. Neither the smoking history nor COexh were
different in the four groups of subjects studied. In contrast, deltaCO increased
in parallel to the degree of airflow obstruction. DeltaCO was >2% (a threshold
value normally used in the clinic to separate smokers from nonsmokers) only in
patients with severe airflow obstruction. A stepwise multivariate analysis showed
that both forced expiratory volume in one second (FEV1) (percentage reference)
and COHb contributed significantly (p<0.0001) to predict deltaCO. This study
shows that the estimation of carboxyhaemoglobin from exhaled carbon monoxide
measurements can be inaccurate in patients with severe airflow obstruction. In
these patients, the direct measurement of carboxyhaemoglobin seems advisable in
clinical practice.
PMID- 10678643
TI - Comparison of two standardized methods of methacholine inhalation challenge in
young adults.
AB - In the European Community Respiratory Health Study (ECRHS), airway responsiveness
to methacholine was determined using the Mefar dosimeter protocol. Elsewhere, the
2-min tidal breathing method has become the preferred standardized method. The
relationship between measurements of responsiveness by these two methods is not
well established. This study measured airway responsiveness to methacholine by
dosimeter and tidal breathing methods in 47 healthy asthmatic subjects aged 20-44
yrs. Tests were performed within 1 week and in random order. Baseline forced
expiratory volume in one second (FEV1) varied by <10% between tests in 42/47
subjects. There was a close association between responsiveness determined by the
two methods. A provocative concentration of methacholine causing a 20% fall in
FEV1 (PC20) value of < or =8.0 mg x mL(-1) (tidal method) used to categorize
airway hyperresponsiveness agreed most closely with a provocative dose of
methacholine causing a 20% fall in FEV1 (PD20) value of < or =0.5 mg (dosimeter
method) (kappa statistic 0.78). Each doubling or halving of PC20 to define a
level of hyperresponsiveness agreed closely with a doubling or halving of PD20.
Assessment of airway responsiveness as provocative dose of methacholine causing a
20% fall in forced expiratory volume in one second by the Mefar dosimeter
protocol gave a close and predictable relationship with provocative concentration
of methacholine causing a 20% fall in expiratory volume in one second assessed
using the tidal breathing method. Airway hyperresponsiveness as determined by the
accepted criterion of provocative concentration of methacholine causing a 20%
fall in expiratory volume in one second < or =8 mg x mL(-1) was best correlated
with provocative dose of methacholine causing a 20% fall in forced expiratory
volume in one second <0.5 mg by Mefar dosimeter.
PMID- 10678644
TI - A simplified method for monitoring respiratory impedance during continuous
positive airway pressure.
AB - The forced oscillation technique is useful in detecting changes in upper airway
obstruction in patients with sleep apnoea undergoing continuous positive airway
pressure (CPAP) ventilation. The aim of this study was to implement and evaluate
a method for estimating respiratory impedance (Zrs) from the pressure and flow
recorded at the inlet of the CPAP tubing. The method is based on correcting
impedance measured at the inlet of the CPAP tubing (Zi) for the effect of the
tubing and the exhalation port. The method was evaluated in mechanical analogues
and in a healthy subject. Sinusoidal oscillation of 5, 10 and 20 Hz were
superimposed on CPAP (5-15 cmH2O). At 5 Hz, the changes in airflow obstruction
were substantially underestimated by Zi. Furthermore, Zi exhibited a negative
dependence on Zrs at 20 Hz. The assessment of Zrs was greatly improved after
correcting Zi for the effects of the CPAP tubing and the exhalation port. Zrs was
well estimated at low frequencies, reaching very high values during total
occlusion (>60 cmH2O x s x L(-1) at 5-10 Hz). These results indicate that changes
in airflow obstruction can be detected using the forced oscillation technique
from pressure and flow recorded on the continuous positive airway pressure
device. This facilitates the clinical application of the forced oscillation
technique for monitoring upper airway patency during sleep.
PMID- 10678645
TI - Shortening the duration of treatment for cervical tuberculous lymphadenitis.
AB - The aim of the study was to determine the optimal duration of treatment for
patients with tuberculous lymphadenitis. The Medline database was searched for
relevant articles published between 1978-1997. Inclusion criteria were study
populations of patients with predominantly cervical tuberculous lymphadenitis in
whom the diagnosis had been confirmed bacteriologically and/or histologically, or
was made probable by using clinical and laboratory markers. Treatment management
had to include at least isoniazid, rifampicin and pyrazinamide and a follow-up of
at least 12 months after the end of treatment. Patients with resistance to
rifampicin and pyrazinamide and previous treatment for tuberculosis were
excluded. The number of patients who relapsed after treatment was calculated. The
study population in eight out of the 35 articles retrieved were suitable for
analysis. Some concerned comparative studies. There were eight treatment
schedules of 6 months' duration and three schedules of 9 months' duration.
Treatment for 6 months resulted in a tuberculous lymphadenitis relapse rate of
13/422=3.3% (95% confidence interval: 1.7-5.5), with a mean follow-up of 31
months after completion of treatment. Treatment for 9 months resulted in a
relapse rate of 3/112=2.7% (95% confidence interval: 0.6-7.8), with a mean follow
up of 20 months. Despite the limitations of the literature available, 6 months of
therapy is probably sufficient for patients with tuberculous lymphadenitis.
PMID- 10678646
TI - Physiotherapy for airway clearance in paediatrics.
AB - The basic therapeutic principles in paediatric chest physiotherapy (CPT) are
identical to those applied in adults. However, the child's growth and development
results in continuing changes in respiratory structure and function, and the
requirement for different applications of CPT in each age group. Forced
expiratory manoeuvres and coughing serve as basic mechanisms for mobilization and
transport of secretions, but the reduced bronchial stability after birth requires
special techniques in very young patients. High externally applied transthoracic
pressures have to be avoided in order to prevent interruption of airflow. In
addition, airway patency is maintained by the application of back pressure and by
liberal use of continuous positive airway pressure. Since sympathomimetic
bronchodilators might further decrease bronchial stability, their use must be
individualized in newborns and young infants. Inspiration is a basic mechanism
for inflating alveolar space behind obstructing mucus plugs. Due to a highly
unstable chest, the premature baby, newborn and infant cannot distend their lung
parenchyma to the same extent as can older patients. Consequently all chest
physiotherapy strategies applied in this age group have to incorporate
appropriate techniques for raising lung volume. Positioning serves to
redistribute ventilation, but the young infant's response to gravitational forces
differs substantially from that of the adult, and consequently strategies used in
older patients have to be modified. In addition, the therapist has to consider
pathology such as bronchial instability lesions and airway hyperresponsiveness
and has to adjust the therapeutic response accordingly. It is particularly
important to consider the special vulnerability of newborns and young infants and
to modify therapeutic interventions to avoid the harm that could otherwise be
inflicted. Consideration of these differences between infant, child and adult and
careful analysis of the available mucus clearance techniques allows tailoring of
an individualized therapeutic approach to the paediatric patient.
PMID- 10678647
TI - Eosinophilic pneumonia and respiratory failure associated with venlafaxine
treatment.
AB - Drugs are well known causes of eosinophilic lung disease. In many patients,
symptoms increase slowly, pulmonary infiltrates and eosinophilia progress over
weeks, and resolve upon withdrawal of the offending agent. Rarely, the disease
presents like acute eosinophilic pneumonia with acute onset of symptoms and
rapidly progressing infiltrates which may be associated with respiratory failure.
This report describe a case of venlafaxine-induced acute eosinophilic pneumonia
causing respiratory insufficiency that rapidly resolved upon institution of
corticosteroid treatment. This 5-hydroxytryptamine and noradrenaline reuptake
inhibitor was previously not known to cause lung or peripheral blood
eosinophilia. Considering the increasing use of this class of medication
physicians have to be aware of this life-threatening and fully reversible
complication.
PMID- 10678648
TI - Severe tracheobronchial stenosis in a patient with Crohn's disease.
AB - Tracheobronchial involvement in Crohn's disease is rare, usually associated with
symptoms of tracheobronchitis, and typically responds well to steroids. The
authors report a case of a 29-yr old patient with Crohn's disease, who presented
with dyspnoea, fever, and a productive cough. Computed tomography of the chest
revealed extensive nodular tracheobronchial stenosis, that was accompanied by
severe mucosal inflammation at bronchoscopy. High-dose oral steroids diminished
the mucosal inflammation, but had limited efficacy on the underlying
tracheobronchial stenosis. It is speculated that this relative ineffectiveness of
steroids may be due to the persistence of the untreated inflammatory process.
PMID- 10678649
TI - Granulomatous Pneumocystis carinii pneumonia in Wegener's granulomatosis.
AB - This study reports on a first case of granulomatous Pneumocystis carinii
pneumonia (PCP) in a human immunodeficiency virus-negative patient with
antineutrophil cytoplasmic antibody-positive Wegener's granulomatosis whilst
receiving immunosuppressive treatment. The patient presented with diffuse
alveolar haemorrhage, pauci-immune rapid progressive glomerulonephritis and
leukocytoclastic vasculitis of the skin. Granulomatous Pneumocystis carinii
pneumonia developed under immunosuppressive treatment with cyclophosphamide and
prednisone. At the time Pneumocystis carinii pneumonia developed, there was a
marked lymphopenia with a very low CD8+ cell count in the blood. Grocott staining
in bronchoalveolar lavage fluid revealed no Pneumocystis carinii. The diagnosis
was made via a video-assisted thoracoscopic lung biopsy which showed granulomas
containing high numbers of Pneumocystis carinii cysts.
PMID- 10678650
TI - Bronchoalveolar lavage in children. ERS Task Force on bronchoalveolar lavage in
children. European Respiratory Society.
PMID- 10678651
TI - Alveolar ejection volume: a misnomer?
PMID- 10678652
TI - Difficult asthma.
PMID- 10678653
TI - New syndrome?: Three sibs diagnosed prenatally with situs inversus totalis, renal
and pancreatic dysplasia, and cysts.
AB - Recently we described a previously apparently undescribed autosomal recessive
syndrome in two sib fetuses with situs inversus totalis, cystic dysplastic
kidneys and pancreas, bowing of the lower limbs and clavicles, severe
intrauterine growth retardation, and oligohydramnios. This syndrome differs from
that of Ivemark and related syndromes due to lack of liver involvement. After
these two sibs, this consanguineous family had a third child and an early
prenatal diagnosis of pancreatic and dysplastic renal cysts was made in the 19.5
week-old fetus. The last case supports the genetic hypothesis.
PMID- 10678654
TI - Short stature in carriers of recessive mutation causing familial isolated growth
hormone deficiency.
AB - Isolated growth hormone deficiency (IGHD) IB is an autosomal recessive disorder
characterized by a good response to exogenous growth hormone (GH) treatment
without development of anti-GH antibodies. Patients with IGHD IB were found to be
compound heterozygotes for deletion and frameshift mutations as well as
homozygotes for splicing mutations in the GH-1 gene. Recently, a novel splicing
mutation in the GH-1 gene was identified in an extended, consanguineous Arab
Bedouin family from Israel with IGHD IB. Prior to the identification of this
mutation, a considerable number of children with short stature in this family
were found normal on pharmacological stimulation for GH release. This observation
prompted a genotype/phenotype correlation of potential heterozygotes in the
family. Carriers of the mutant GH-1 allele were found as a group to have a
significantly shorter stature than normal homozygote (mean standard deviation
scores, 1.67 and -0.40, respectively, P<0.05). Moreover, 11 of 33 (33%)
heterozygotes, but only 1 of 17 (5.9%) normal homozygotes, had their height at 2
or more SD below the mean. Overall, 48.5% of studied heterozygotes were found to
be of appreciably short stature with height at or lower than the 5th centile (>
or = -1.7 SD), whereas only 5.9% of the normal homozygotes did (P<0.004). This
phenomenon of heterozygotes for a recessive mutation in the GH-1 gene manifesting
short stature, might imply that some such mutations may account for non-GH
deficiency reduced height in the general population.
PMID- 10678655
TI - Congenital absence of permanent teeth in a six-generation Chinese kindred.
AB - We report on rare, heritable, permanent tooth agenesis in a large Chinese
kindred. The congenital absence of permanent teeth except the first and second
accessory teeth was observed in 52 individuals through six successive generations
in the kindred comprising 328 members. Clinical assessments were carried out, and
inheritance mode and spousal influence of the anomaly on their offspring were
analyzed. Consequently, the anomaly was transmitted in an autosomal dominant
fashion with incomplete penetrance (P = 0.88), and no significant clinical
manifestations other than the oligodontia were found. A geographical or
environmental effect on the affected individuals was obviously eliminated,
because any who are related to the kindred but live under the same conditions are
fully healthy. The disorder we describe, therefore, differs from any previously
reported oligodontia/anodontia syndromes. The oligodontia ranged from a few teeth
to the whole set of teeth, and usually occurred at a period from age 7 or 8
years, the time when primary teeth are normally replaced by permanent teeth, to
the forties. Roentgenography of the affected persons indicated that only the
first and/or second accessory teeth with tooth buds developed as permanent teeth.
In fact, the diphyodontic germination sometimes occurred in the oral cavity of
the affected individuals.
PMID- 10678656
TI - Spondylometaphyseal dysplasia: Sedaghatian type.
AB - We report a case of spondylometaphyseal dysplasia in an infant who was born to
nonconsanguineous Yemeni parents. Radiological findings were consistent with
lethal metaphyseal chondrodysplasia (Sedaghatian type). Although all previously
reported cases died within 4 days of life, our patient survived 161 days. This
reported case was thoroughly investigated for serum calcium, magnesium, zinc,
ammonia, phosphate level, alkaline phosphatase, parathormone level, liver and
renal function test, TORCH, metabolic screening, skeletal survey, chromosomal
studies, muscle enzymes, EEG, computed tomography scan, and magnetic resonance
imaging (brain). Genomic DNA analysis of patient and parents were sent to the
Faculty de Medicine Xavier Bichat, France, but yet abnormal gene could not be
detected.
PMID- 10678657
TI - Cri du chat syndrome: changing phenotype in older patients.
AB - The cri du chat syndrome or 5p deletion syndrome is a well-delineated clinical
entity and has an incidence of 1/50,000 in newborn infants. A de novo deletion is
present in 85% of the patients. Ten to 15% are familial cases with more than 90%
due to a parental translocation and 5% due to an inversion of chromosome 5.
Although the size of the deleted segment varies, the critical segment that is
deleted in all patients appears to be 5p15.2. The clinical picture is well known
in younger patients and includes the typical high-pitched cry, psychomotor
retardation, microcephaly, growth rate failure, and craniofacial abnormalities
including round face, hypertelorism, broad nasal bridge, downward slanting
palpebral fissures, and micrognathia. With advancing age, the clinical picture
becomes less striking. We present seven patients with 5p deletion syndrome, who
were between age 16 and 47 years. Comparing their phenotype at several ages, a
change of their phenotype was noted. Some of the clinical characteristics became
more evident such as long face, macrostomia, and scoliosis. All patients were
severely or profoundly mentally retarded except one patient who was mildly
mentally retarded. The diagnosis was difficult to make in some of the patients
who were first seen at an older age. In some of them, the craniofacial appearance
resembled that seen in Angelman syndrome. Most patients had periods of
destructive behavior, self mutilation, and aggression. The clinical diagnosis
should be confirmed as soon as possible with cytogenetic investigation to provide
specific support, prevention, and treatment of complications. Therefore, it is
important to perform follow-up studies in young children to determine their
outcome after infant-stimulation programs.
PMID- 10678658
TI - Splicing mutations in the COL3 domain of collagen IX cause multiple epiphyseal
dysplasia.
AB - We report on a three-generation family with multiple epiphyseal dysplasia (MED).
The propositus had typical MED findings of knees, ankles, elbows, and hands in
childhood. The 2 other affected relatives were adults. The main clinical findings
consisted of osteochondritis dissecans and osteoarthritis of the knees. DNA of
the propositus was screened for mutations by conformation sensitive gel
electrophoresis in all known candidate genes for MED, cartilage oligomeric matrix
protein, and the COL9A1, COL9A2, and COL9A3 genes coding for the alpha1, alpha2,
and alpha3 chains of collagen IX. The screening identified a unique change in PCR
products of exon 3 of the COL9A3 gene. Sequencing indicated a G to A mutation in
the acceptor splice site (G(-1)IVS2-->A) of intron 2 in all affected relatives,
but not in unaffected relatives. Analysis of RNA from the propositus indicated a
skipping of exon 3, and thus, a deletion of 12 amino acid residues as a
consequence of the mutation. All four other collagen IX mutations previously
described in MED have consequences identical to that characterized here, thus it
seems likely that this type of mutation in collagen IX plays an important role in
the pathogenesis of MED.
PMID- 10678659
TI - Rothmund-Thomson syndrome due to RECQ4 helicase mutations: report and clinical
and molecular comparisons with Bloom syndrome and Werner syndrome.
AB - Rothmund-Thomson syndrome (RTS), an autosomal recessive disorder, comprises
poikiloderma, growth deficiency, some aspects of premature aging, and a
predisposition to malignancy, especially osteogenic sarcomas. Two kindreds with
RTS were recently shown to segregate for mutations in the human RECQL4 helicase
gene. We report identification of a new RTS kindred in which both brothers
developed osteosarcomas. Mutation analysis of the RECQL4 gene was performed on
both brothers and both parents. The brothers were shown to be compound
heterozygotes for mutations in the RECQL4 gene, including a single basepair
deletion in exon 9 resulting in a frameshift and early termination codon and a
base substitution in the 3-prime splice site in the intron-exon boundary of exon
8, which would be predicted to cause a deletion of at least part of a consensus
helicase domain. Each parent was shown to be a heterozygote carrier for one
mutation. This report strengthens the association between mutations in RECQL4
helicase gene and RTS. Two other recessive disorders, Bloom syndrome and Werner
syndrome, are known to be due to other human RECQ helicase gene mutations. These
three disorders all manifest abnormal growth, premature aging, and predisposition
to site-specific malignancies. The clinical and molecular aspects of RTS, Bloom
syndrome, and Werner syndrome are compared and contrasted.
PMID- 10678660
TI - Twin carriers of X-linked agammaglobulinemia (XLA) due to germline mutation in
the Btk gene.
AB - We report on an X-linked agammaglobulinemia (XLA) family in which mothers of two
affected cousins were monozygotic twins. We analyzed the Btk gene of several
members in three generations of the family by SSCP analysis, DNA sequencing, and
RFLP analysis following polymerase chain reaction-amplification of the individual
exons. We identified a missense point mutation, G1817C (R562P), in exon 17 of the
Btk gene in the affected cousins. The same mutation was also present in both
mothers (twin sisters) of the cousins identifying them as carriers. However, the
mutation was absent in all other relatives including the grandmother of the
cousins (mother of the twin sisters). This strongly suggests that the mutation in
the Btk gene had originated in one of the germ lines or in the zygote. This may
be the first demonstration of a germ line (or zygotic) mutation in XLA.
PMID- 10678661
TI - Routine prenatal diagnosis of aneuploidy by FISH studies in high-risk
pregnancies.
AB - This study is a prospective clinical trial with fluorescent in situ hybridization
(FISH) as a "routine" test for prenatal detection of the most common aneuploidies
in high-risk pregnancies. Since April 1996, FISH studies with multicolor,
commercially available, specific probes for chromosomes 13, 18, 21, X, and Y have
been routinely performed in our cytogenetic laboratory on uncultured chorionic
villous samplings (CVS), amniotic fluid samples, or fetal blood obtained by
cordocentesis from patients with major or minor fetal anomalies detected by
ultrasonography. Among the 4,193 prenatal samples analyzed between April 1996 and
June 1998, routine FISH studies were ordered by the referring physicians on 301
(7.2%) cases. Aneuploidies were detected in 32 (10.6%) samples. Fourteen trisomy
21, 10 trisomy-18, 3 trisomy-13, 4 monosomies of X, and 1 case of triploidy were
diagnosed by FISH. All 1,505 hybridizations were informative, and all 301 results
were available and reported to the referring physicians in 24-48 hr. All relevant
FISH results were confirmed by subsequent cytogenetic analysis. In 10 (3.8%)
cases with normal FISH results, the final cytogenetic analysis revealed abnormal
chromosomal rearrangements that could not be detected by the routine FISH
studies. We conclude that rapid FISH analysis of interphase, uncultured fetal
cells is an accurate and very sensitive method for routine prenatal diagnosis of
the most common aneuploidies in high-risk pregnancies.
PMID- 10678662
TI - Boy with syndactylies, macrocephaly, and severe skeletal dysplasia: not a new
syndrome, but two dominant mutations (GLI3 E543X and COL2A1 G973R) in the same
individual.
AB - An unusual combination of syndactylies, macrocephaly, and severe skeletal
dysplasia was observed in a newborn infant. A history of digital anomalies in the
father and grandfather lead to the diagnosis of dominantly inherited Greig
cephalopolysyndactyly syndrome (GCPS, MIM #175700). Having explained the digital
findings and macrocephaly, the skeletal changes were thought to fit best
congenital spondyloepiphyseal dysplasia (SEDC MIM #183900), a type II collagen
disorder. Molecular analysis confirmed the presence of two dominant mutations in
the propositus: a GLI3 mutation (E543X), which was present also in the father and
grandfather, and a de novo COL2A1 mutation leading to a G973R substitution. Thus,
this boy combined the syndactyly-macrocephaly phenotype of Greig
cephalosyndactyly syndrome with a severe form of spondyloepiphyseal dysplasia
caused by the structural defect in type II collagen. The diagnostic difficulties
posed by the combination of two genetic disorders and the contribution of
molecular diagnostics are well illustrated by this case.
PMID- 10678663
TI - Giant congenital aortic aneurysm with cleft sternum, supraumbilical raphe, and
hemangiomatosis: report and review.
AB - We report on a child with giant congenital aortic aneurysm, sternal defect,
hemangiomas of face, supraumbilical raphe, and review the only two other cases
reported to date. Congenital aortic aneurysm is an ominous malformation that has
to be systematically searched in children with the sternal malformation/vascular
dysplasia complex.
PMID- 10678664
TI - Pathogenetic classification of a series of 27,145 consecutive infants with
congenital defects.
AB - We studied a series of 27,145 consecutive infants with congenital defects and
classified them into the currently recognized pathogenetic types of errors of
morphogenesis, as defined by the International Working Group [Spranger et al.,
1982: J Pediatrics 1:160-165]. Of all infants with congenital defects, 97.94% had
malformations, 3.92% deformations, and 1.65% disruptions. Malformations
associated with deformations were present in 3.12% of children with congenital
anomalies, malformations with disruptions in 0.18%, deformations with disruptions
in 0.07%, and malformations with deformations and disruptions in 0.14%. While
deformations, including deformation sequences, were 2.38 times more common than
disruptions and disruption sequences, isolated disruptions (1.27%) were more
frequent than isolated deformations (0.59%). Knowledge of the frequencies of the
different types of errors of morphogenesis (malformations, deformations,
disruptions, developmental field defects, associations, complexes, unrecognized
patterns of multiple congenital anomaly, and syndromes) may be of great value in
the evaluation of patients with congenital anomalies.
PMID- 10678665
TI - Recurrence risk for sibs of children with "sporadic" achondroplasia.
AB - Because of gonadal mosaicism, the risk of recurrence of achondroplasia in the
sibs of achondroplastic children with unaffected parents is presumably higher
than twice the mutation rate, but it has not been measured. Data from 11 Canadian
genetics centers provide an estimate of 1/443, or 0.02%.
PMID- 10678666
TI - Ataxia-pancytopenia syndrome.
AB - We report on a Mexican girl who developed cerebellar ataxia at age 3 years and
pancytopenia at age 13 years. Cerebral computed tomography scan and magnetic
resonance imaging showed evidence of severe cerebellar atrophy. Telangiectasias
were not present; immunoglobulins and alpha-fetoprotein levels were normal.
Cytogenetic studies showed no evidence of spontaneous chromosome aberrations, a
normal rate of diepoxybutane (DEB) and mitomycin C (MMC)-induced chromosome
aberrations, but an increased response to bleomycin. The phenotype support the
diagnosis of ataxia-pancytopenia syndrome, although monosomy of chromosome 7 was
not found in bone marrow. The cytogenetic studies suggest that this may be a
chromosomal instability disorder.
PMID- 10678667
TI - Whistling face syndrome with normal hands.
PMID- 10678668
TI - Second case of bladder carcinoma in a patient with Costello syndrome.
PMID- 10678669
TI - Incidence of Smith-Lemli-Opitz syndrome in Slovakia.
PMID- 10678670
TI - Miscarriage and use of multi-vitamins or folic acid.
PMID- 10678671
TI - The methods to measure stable isotope tracers and their applications to clinical
nutrition problems keep getting better...
PMID- 10678672
TI - Energy expenditure in wasting diseases: current concepts and measurement
techniques.
AB - Weight loss occurs secondary to many acute and chronic disease states. The
measurement of energy balance is crucial to understanding disease-related changes
in body composition. This review considers various techniques for measuring
energy expenditure in wasting diseases and the current concepts regarding the
effect of disease on energy expenditure.
PMID- 10678673
TI - Neutron activation analysis determination of body composition.
AB - The nutritional status of patients can be evaluated by monitoring changes in body
composition, including the depletion of protein and muscle, adipose tissue
distribution and changes in hydration status, bone or cell mass. Neutron
activation analysis is a unique reference tool for the in-vivo determination of
body composition. In this review we describe the recent changes in the field that
followed the advent of new portable generators of fast neutrons, capable of
performing elemental analysis in the clinical environment. New models were
developed based on the partition of the measurable elements of the body. The
recent developments help evaluate new treatments for wasting and obesity, in
which change in body composition is the main outcome.
PMID- 10678674
TI - Use of gas chromatography-combustion-isotope ratio mass spectrometry in nutrition
and metabolic research.
AB - Linking gas chromatography via an on-line combustion interface to isotope ratio
mass spectrometry has opened the door to high-precision compound-specific isotope
analysis. For this reason, gas chromatography-combustion-isotope ratio mass
spectrometry is now increasingly employed in metabolic and nutritional research
because it offers a reliable and risk-free alternative to the use of radioactive
tracers.
PMID- 10678675
TI - Inter-organ fluxes in a methodological perspective.
AB - Inter-organ fluxes remain a cornerstone as an investigating tool in metabolic
research. Combination with isotopic labelling and microdialysis have now opened
new possibilities of addressing a number of questions not previously accessible.
However, the technique requires a high level of knowledge among investigators as
well as among readers.
PMID- 10678676
TI - Plasma cytokines: what we are measuring.
AB - Immunoassays, in particular enzyme-linked immunosorbent assays, have become
increasingly important tools for the measurement of plasma cytokines. However,
many technical factors contribute to the complexity of their quantitation. The
study of plasma cytokine levels is also of limited value, and complementary
methods are now available to investigate and understand more precisely the
involvement of cytokines in pathological processes.
PMID- 10678677
TI - Methods for assessing the potential of prebiotics and probiotics.
AB - Prebiotics and probiotics are microflora management tools designed to improve
human health. Both are dietary materials that fortify components of the gut flora
seen as 'beneficial'. Gut flora modulation is an important area of the
nutritional sciences, however, it is imperative that reliable methodologies be
used to determine efficacy. This review will discuss the current techniques used
in prebiotic and probiotic research.
PMID- 10678678
TI - Modulation of endogenous glutathione availability.
AB - Glutathione is quantitatively the most important antioxidant and scavenger. In
addition it has a number of important functions in amino acid transport across
membranes, in protein synthesis and degradation, in gene regulation and in
cellular redox regulation. It becomes more and more evident that depletion of
glutathione is associated with states of severe diseases. From this perspective,
the possibility of manipulating the availability of glutathione becomes a very
attractive form of treatment. In this review, new insights into pathophysiology
and the regulation of glutathione metabolism, in addition to effects of
precursors to and stimulants of glutathione synthesis, are covered. It is very
likely that glutathione precursors will soon be an important pharmacological tool
for treatment in a number of diseased states.
PMID- 10678679
TI - N-acetyl-cysteine in the therapy of HIV-positive patients.
AB - Randomly selected asymptomatic HIV-positive persons reveal, on average, a massive
daily loss of sulphur, which appears to represent in first approximation the mean
loss throughout the asymptomatic stage, and may explain the widely observed
decrease in cyst(e)ine and glutathione levels. This sulphur loss is reasonably
expected to lead, within a few years, to a life-threatening condition and may,
therefore, contribute decisively to disease progression. Importantly, the rate of
sulphur loss is not ameliorated by highly active antiretroviral therapy and may
contribute to antiretroviral treatment failure. Several clinical trials on N
acetyl-cysteine treatment of HIV-positive patients have revealed various
therapeutic effects, but did not meet the rigorous standards for approval by the
health authorities.
PMID- 10678680
TI - Recent advances in conjugated linoleic acid research.
AB - New results on the physiological properties of conjugated linoleic acid have been
published by several working groups, especially showing the effects of single
conjugated linoleic acid isomers on carcinogenesis and body composition.
Recently, other studies have shown that conjugated linoleic acid has an influence
on diabetes mellitus, platelet aggregation and the immune system. Conjugated
linoleic acid was found to modify prostaglandin metabolism and delta9-desaturase
activity and influence apoptosis. Furthermore, improved analytical methods using
13C nuclear magnetic resonance and silver ion high performance liquid
chromatography are available to investigate the composition of conjugated
linoleic acid mixtures and the exact structure of separated isomers. Also, the
synthesis of isolated isomers is described, as published by different authors, in
order to determine further the effects of each single conjugated linoleic acid
isomer. In addition, new data on the contents of conjugated linoleic acid in
foods, human adipose tissue and fluids are given in this review. More data need
to be obtained using isolated isomers, with particular emphasis on studies in
humans.
PMID- 10678681
TI - Benefits and dangers of iron during infection.
AB - Iron is essential for both human and microbial metabolism, and it is therefore
important that iron status is maintained at a level that permits optimal immune
responses by the host but does not facilitate availability of iron to
microorganisms. This paper reviews the role of iron in resistance to infection,
with particular reference to malaria and hepatitis C, and discusses the
desirability of iron supplementation of populations at risk of infection.
PMID- 10678682
TI - Carbohydrate and exercise.
AB - Total body carbohydrate stores are limited, and are often less than the
carbohydrate requirements of athletic training and competition. However, the
availability of carbohydrate as a substrate for muscle metabolism is a critical
factor in the performance of both high-intensity intermittent work and prolonged
aerobic exercise. The rate of carbohydrate oxidation during exercise is tightly
regulated, with glucose availability closely matching the needs of the working
muscles. Both the absolute and relative work rate play important roles in the
regulation of substrate metabolism: carbohydrate-based fuels predominate at
moderate to high power outputs, with muscle glycogen and glucose utilization
scaling exponentially to the relative work rate. As such, strategies to maintain
or enhance carbohydrate availability, such as the ingestion of carbohydrate
before, during and after exercise, are critical to the performance of a variety
of sports events, and are a key recommendation in current sports nutrition
guidelines.
PMID- 10678683
TI - Dietary fat and physical performance.
AB - Although the relationship between dietary carbohydrate and physical performance
is well described, there is much controversy about the relationship between
dietary fat and physical performance. Recently, several studies have tried to
clarify this relationship. Here the effects of acute fat on metabolism and
performance will be discussed, as well as the effects of short-term and long-term
high-fat diets.
PMID- 10678684
TI - The tricarboxylic acid cycle in human skeletal muscle: is there a role for
nutritional intervention?
AB - The tricarboxylic acid (TCA) cycle is essential for oxidative energy production.
The expansion (anaplerosis) of the intermediates of the TCA cycle is achieved via
a number of pathways, and is known to be influenced by metabolic status and
nutritional and pharmacological interventions. Contraction is associated with
anaplerosis in skeletal muscle, and some authors have suggested that the rate of
anaplerosis can limit oxidative energy delivery. The results of more recent
studies, however, are consistent with the idea that expansion of the muscle TCA
intermediate pool is principally a reflection of muscle pyruvate availability,
and is of little functional importance to TCA cycle flux, thereby indicating that
any intervention aimed at increasing TCA intermediates expansion will be of
little practical value.
PMID- 10678685
TI - Protein and physical performance.
AB - Important advances have been made in the understanding of the regulation of
protein metabolism, which are of relevance to those interested in maximizing
muscle performance in sport and aging. The use of 24 h amino acid infusion
studies, the development of methods to measure skeletal muscle fractional
breakdown rate and the fractional synthetic rate of specific proteins have and
will continue to enhance our understanding of protein metabolism in exercise.
Recent studies have demonstrated potentially beneficial effects upon protein
metabolism by altering the composition and timing of nutrient delivery. Exercise
and nutritional interventions may positively influence the negative effects of
aging upon protein metabolism.
PMID- 10678686
TI - Amino acid supplements to improve athletic performance.
AB - This review provides a critical evaluation of the metabolic rationale for the use
of individual amino acids as nutritional ergogenic (work-generating) aids in
athletes. The conclusion is that in contrast to the claims made on sport
nutrition products, branched-chain amino acids do not improve endurance
performance, that the evidence that glutamine supplements may improve immune
function is rather weak, and that the available commercial supplements contain
too little arginine to increase growth hormone levels. No studies have been
performed to investigate the claim that tyrosine supplements can improve
explosive exercise.
PMID- 10678687
TI - Bibliography. Current world literature. Assessment of nutritional status and
analytical methods.
PMID- 10678688
TI - Bibliography. Current world literature. Nutraceutics.
PMID- 10678689
TI - Bibliography. Current world literature. Nutrition and physiological function.
PMID- 10678690
TI - The effect of variability of unattended information on global and local
processing: evidence for lateralization at early stages of processing.
AB - Visual objects can often be analyzed as hierarchical in structure, composed of
local elements that are spatially arranged to form a global shape. The brain
mechanisms involved in the analysis of hierarchical figures have been under
considerable scrutiny in recent years, and one of the many interesting features
that have emerged is that there is an asymmetry across the two hemispheres for
global (right hemisphere) vs local (left hemisphere) processing. Event-related
potentials (ERP) were used to examine selective attention to global or local
levels of hierarchical figures to determine the stage of processing at which the
asymmetry first emerges. Two conditions were tested, one in which unattended
information was variable from trial to trial, and one in which it was not. The
variability of unattended information influenced the lateralization of
processing. Presentation of invariable, neutral distractors resulted in
global/local processing asymmetries at early stages (P1). In contrast,
presentation of variable, task-relevant distractors resulted in processing
asymmetries that occurred at much later stages (N2). Our hypothesis is that
lateralized enhancement of neural populations in extrastriate cortex results from
both selective attention to locations in the visual field, as well as selective
attention to global or local information. We suggest that unattended information
that varies from trial to trial is processed in parallel with attended
information, masking hemisphere biases for local vs global information at early
stages of processing.
PMID- 10678691
TI - Implicit and explicit memory: a functional dissociation in persons with Down
syndrome.
AB - This study aimed at investigating implicit and explicit long-term memory
functioning in subjects with Down syndrome (DS) compared to Mental-Age (MA)
matched normal children. For this purpose, tests of verbal and visuo-perceptual
explicit memory, verbal and visual repetition priming and procedural learning
tasks were administered to 14 DS and 20 MA subjects. Our results document
comparable implicit memory abilities in the two groups. In contrast, regarding
explicit memory, normal children performed better than DS individuals. These
results reveal a functional dissociation between implicit and explicit memory in
subjects with DS. Theoretical and rehabilitative implications are discussed.
PMID- 10678692
TI - The nature and staging of attention dysfunction in early (minimal and mild)
Alzheimer's disease: relationship to episodic and semantic memory impairment.
AB - The development of cholinergic therapies for Alzheimer's disease (AD) has
highlighted the importance of understanding the role of attentional deficits and
the relationship between attention and memory in the earliest stages of the
disease. Variability in the tasks used to examine aspects of attention, and in
the disease severity, between studies makes it difficult to determine which
aspects of attention are affected earliest in AD, and how attentional impairment
is related to other cognitive modules. We tested 27 patients in the early stages
of the disease on the basis of the MMSE (minimal 24-30 corresponding to minimal
cognitive impairment, very mild or possible AD in other classifications; and mild
18-23) on a battery of attentional tests aimed to assess sustained, divided, and
selective attention, plus tests of episodic memory, semantic memory,
visuoperceptual and visuospatial function, and verbal short-term memory. Although
the mildly demented group were impaired on all attentional tests, the minimally
impaired group showed a preserved ability to sustain attention, and to divide
attention based on a dual-task paradigm. The minimally demented group had
particular problems with response inhibition and speed of attentional switching.
Examination of the relationship between attention and other cognitive domains
showed impaired episodic memory in all patients. Deficits in attention were more
prevalent than deficits in semantic memory suggesting that they occur at an
earlier stage and the two were partially independent. Impairment in
visuoperceptual and visuospatial functions and verbal short-term memory were the
least common. Although attention is impaired early in AD, 40% of our patients
showed deficits in episodic memory alone, confirming that amnesia may be the only
cognitive deficit in the earliest stages of sporadic AD.
PMID- 10678693
TI - Hemispheric asymmetries in the resolution of lexical ambiguity.
AB - The linguistic phenomenon of lexical ambiguity has been intensively investigated
as a means of gaining insight into general mechanisms of lexical access. It is
now evident that both context and meaning frequency are significant factors in
the determination of lexical outcomes. This suggests that hemispheric processes
may be relevant to the resolution of lexical ambiguity, because both factors have
been shown to have differential implications for the processing of language in
the hemispheres. This study set out to examine the effects of context and meaning
frequency on the resolution of ambiguous word meanings within the hemispheres.
Sentences presented at the beginning of each trial embodied contexts which
expressed either the dominant or subordinate meaning of a terminating homographic
prime. Laterally presented target words reflected senses of the prime which were
either consistent with, or inconsistent with, the context created by the
preceding sentence. The most interesting results were observed at short prime
target intervals where it was found that although dominant meanings of the target
did not give rise to visual field differences, subordinate meanings evoked
facilitated responses only in the left visual field. This result suggests that
the right hemisphere immediately and exhaustively activates the various meanings
associated with a word, while in the left hemisphere initial access is
selectively restricted to the dominant meaning. It is proposed that this reflects
a model of language comprehension in which the right hemisphere plays a
supportive role by making available a set of alternative and less probable word
meanings, thus freeing the left hemisphere to focus cognitive resources upon the
most probable meaning of a word in a given context.
PMID- 10678694
TI - Divided visuo-spatial attention systems with total and anterior callosotomy.
AB - The role of the corpus callosum in the inter-hemispheric integration of the visuo
spatial attention system, was investigated in patients with a total callosotomy
or with an anterior callosal section. Subjects produced simple reaction times
(RTs) to visual targets shown to the left or right visual hemifield. Preceding
the target by an interval of 500 ms, arrow cues predicting the target location
were shown left and right of the point of ocular fixation. For a majority of
total and anterior callosotomy patients, results with valid focused cues (both
arrows pointing to the target location) and with divided-attention cues (arrows
pointing away from fixation) did not differ and both conditions produced shorter
RTs than with neutral cues (equal signs). In contrast, neurologically intact
subjects showed equal RTs with divided-attention and neutral cues, whereas valid
focused cues produced reduced RTs relative to neutral cues. These results
indicate that most split-brains, in contrast to normal observers, are capable of
directing their attention to left and right visual field locations
simultaneously, and therefore that each cerebral hemisphere controls its own
visuo-spatial attention mechanism.
PMID- 10678695
TI - Material-specific and non-specific attention deficits in children and adolescents
following temporal-lobe surgery.
AB - Attentional control in children and adolescents with unilateral temporal-lobe
excisions was examined using two experimental tasks, a lexical-decision and a
spatial-cue task, and a standardized vigilance task. Participants with left
temporal excisions took longer than controls to reorient their attention after
invalid cues compared to neutral cues in the lexical task and they made more
errors on all three of the tasks. Participants with right temporal excisions
differed from controls in the number of errors made on the spatial task. No
differences were found between the lesion and control groups on reaction-time
measures of the spatial task. The results suggest that a material-specific
inhibition impairment, as well as a more general sustained attention deficit, may
result after a left temporal excision in childhood or adolescence. These deficits
are considered in the context of neuroanatomical models of attentional control.
PMID- 10678696
TI - Interhemispheric asymmetry of the human motor cortex related to handedness and
gender.
AB - Most people are right-handed, preferring the right hand for skilled as well as
unskilled activities, but a notable proportion are mixed-handed, preferring to
use the right hand for some actions and the left hand for others. Assuming a
structural/functional correlation in the motor system we tested whether
asymmetries in hand performance in consistent right and left handers as well as
in mixed handers are associated with anatomical asymmetries in the motor cortex.
In vivo MR morphometry was used for analyzing interhemispheric asymmetry in the
depth of the central sulcus in the region of cortical hand representation of 103
healthy subjects. Subjects were tested both for hand preference and hand
performance. As expected, left-right differences in hand performance differed
significantly between consistent right, consistent left and mixed handers and
were independent on gender. Male consistent right handers showed a significant
deeper central sulcus on the left hemisphere than on the right. Anatomical
asymmetries decreased significantly from male consistent right over mixed to
consistent left handers. Sixty two per cent of consistent left handers revealed a
deeper central sulcus on the right than on the left hemisphere, but for the group
as a whole this rightward asymmetry was not significant. No interhemispheric
asymmetry was found in females. Thus, anatomical asymmetry was associated with
handedness only in males, but not in females, suggesting sex differences in the
cortical organization of hand movements.
PMID- 10678697
TI - Insights from semantic dementia on the relationship between episodic and semantic
memory.
AB - An influential theory of long-term memory, in which new episodic learning is
dependent upon the integrity of semantic memory, predicts that a double
dissociation between episodic and semantic memory is not possible in new
learning. Contrary to this view, we found, in two separate experiments, that
patients with impaired semantic memory showed relatively preserved performance on
tests of recognition memory if the stimuli were perceptually identical between
learning and test. A significant effect of semantic memory was only seen when a
perceptual manipulation was introduced in the episodic task. To account for these
findings, we propose a revision to current models of long-term memory, in which
sensory/perceptual information and semantic memory work in concert to support new
learning.
PMID- 10678698
TI - The calculating brain: an fMRI study.
AB - To explore brain areas involved in basic numerical computation, functional
magnetic imaging (fMRI) scanning was performed on college students during
performance of three tasks; simple arithmetic, numerical magnitude judgment, and
a perceptual-motor control task. For the arithmetic relative to the other tasks,
results for all eight subjects revealed bilateral activation in Brodmann's area
44, in dorsolateral prefrontal cortex (areas 9 and 10), in inferior and superior
parietal areas, and in lingual and fusiform gyri. Activation was stronger on the
left for all subjects, but only at Brodmann's area 44 and the parietal cortices.
No activation was observed in the arithmetic task in several other areas
previously implicated for arithmetic, including the angular and supramarginal
gyri and the basal ganglia. In fact, angular and supramarginal gyri were
significantly deactivated by the verification task relative to both the magnitude
judgment and control tasks for every subject. Areas activated by the magnitude
task relative to the control were more variable, but in five subjects included
bilateral inferior parietal cortex. These results confirm some existing
hypotheses regarding the neural basis of numerical processes, invite revision of
others, and suggest productive lines for future investigation.
PMID- 10678699
TI - Large plaque parapsoriasis: clinical and genotypic correlations.
AB - Twelve patients with large plaque parapsoriasis (LPP) were investigated for the
presence of predominant T-cell clones, analyzing the T-cell receptor (TCR) gamma
chain gene. The diagnostic and prognostic significance of TCR gene rearrangement
status was assessed by a correlation with the long-term clinical follow-up. Six
out of 12 patients showed a clonal T-cell population. Clinically, among the
patients with clonal disease one developed clearcut mycosis fungoides (MF) after
a follow-up of 8 years, in the other 5 patients no such diagnosis could be made
after follow-up of 2-21 years (median: 9 years). In patients with polyclonal
infiltrates the lesions remained virtually unchanged. These findings indicate
that in LPP TCR gene rearrangement status has no prognostic significance and does
not allow distinction of LPP and early MF. Both conditions show a clonal T-cell
infiltrate with similar frequency, are very similar in clinical and histologic
presentation and according to recent studies share the same low risk to develop
overt MF. Therefore both terms refer to the identical clinical situation. This
should be designated as early MF and efforts should concentrate on identifying
those patients that are at risk to develop aggressive disease.
PMID- 10678700
TI - The microanatomy of the distal arrector pili: possible role for alpha1beta1 and
alpha5beta1 integrins in mediating cell-cell adhesion and anchorage to the
extracellular matrix.
AB - The arrector pili (AP) muscle is a small band of smooth muscle that attaches
proximally to the bulge area of the pilosebaceous apparatus in the reticular
dermis and extends up toward the epidermis. The distal anatomy of the AP and the
anchorage mechanism allowing hair erection have not been previously described.
Integrins are likely candidates mediating this attachment. Immunohistochemical
techniques were used to determine the distribution of the following integrins:
alpha1, alpha2, alpha3, alpha4, alpha5, alpha6 and beta1 as well as fibronectin.
Frozen human scalp tissue was sectioned in traditional planes, obliquely and
horizontally to visualize microanatomy in three dimensions. Histological
examination revealed that the distal portions of smooth muscle fibers splay
extensively between collagen bundles of the upper dermis. Integrin subunits
alpha1, alpha5 and beta1 were expressed by the AP muscle. Analysis of the
relative density of immunoreactivity in digitized sections revealed increased
alpha5 subunit expression at the extracellular matrix (ECM)-muscle interface.
These data suggest that anchorage of the AP muscle to the ECM is via alpha5beta1
integrin and alpha1beta1 integrin functions in muscle cell-cell adhesion.
Extensive splaying of smooth muscle fibers may allow increased surface area
contact between the ECM and smooth muscle cells expressing peripherally situated
alpha5 integrin.
PMID- 10678701
TI - Melanocytes in nevi and melanomas synthesize basement membrane and basement
membrane-like material. An immunohistochemical and electron microscopic study
including immunoelectron microscopy.
AB - Light microscopic studies have shown that nevus cell nests and melanoma nests are
surrounded by basement membrane (BM) material containing type IV collagen and
laminin. This study confirms this by electron microscopy and relates it to
proteins which interact with the basement membrane. Nevi except for dysplastic
and Spitz nevi, malignant melanomas, and melanoma metastases were studied by
immunohistopathology, routine electron microscopy (EM), and immunoelectron
microscopy. The lesions were incubated with monoclonal antibody (moAb) against
type IV collagen, laminin, and the integrin alpha6 and studied by light
microscopy. In addition, melanomas were studied by immuno-EM after incubation
with a moAb against matrix metalloproteinase-2 (MMP-2). Nevus cell nests and
melanoma nests are surrounded by BM material containing type IV collagen and
laminin by immuno-EM. The BM material various in thickness and is amorphous. Type
IV collagen, laminin, and MMP-2 are synthesized by melanoma cells as well as
adjacent fibroblasts. Destruction or loss of the BM is not mandatory for melanoma
invasion or even metastasis. Possibly the BM material is a protective wall for
melanoma cells. Interactions between melanocytes and the extracellular matrix of
which the BM is a part, can be traced back to the migration of melanocytes from
the neural crest.
PMID- 10678702
TI - Benign mucinous metaplasia of the penis. A lesion resembling extramammary Paget's
disease.
AB - Benign mucinous metaplasia in the surface epithelium of the genital area is rare
and has only been reported once in the vulva. A unique case of benign mucinous
metaplasia of the prepuce in a 65-year-old man is reported here. The lesion
measured 0.6 cm, was located in the mucous surface of the foreskin, and showed
acid mucin containing cells. We regard benign mucinous metaplasia as a reactive
rather than a neoplastic process. The main lesions to be considered in the
differential diagnosis are mucinous syringometaplasia, extramammary Paget's
disease, cutaneous squamous cell carcinoma in situ with mucinous metaplasia,
superficial spreading malignant melanoma, and epidermotropic metastasis. The
confinement of mucin-containing cells to the epidermis, the absence of nuclear
atypia, the basal orientation of the nuclei, the predominant location of the
cells in the upper layers of the epithelium, and the fact that the mucinous cells
are replacing the squamous epithelium rather that infiltrating it, all assist in
recognizing mucinous metaplasia of the penis as a specific and benign entity.
PMID- 10678703
TI - Extranodal peripheral T-cell lymphoma with angiocentric growth pattern and
Epstein-Barr viral DNA associated affecting paratesticular soft tissue.
AB - Peripheral T-cell lymphomas are uncommon, accounting for only 10% to 15% of all
non-Hodgkin lymphomas and their classification has been controversial. We report
a case of peripheral T-cell lymphoma with angiocentric growth pattern which
presented as a paratesticular tumoral nodule in a 47-year-old-man. Formalin-fixed
paraffin-embedded samples from the paratesticular tumor and non-infiltrated
adjacent tissue were submitted to histological, immunohistochemical, polymerase
chain reaction (PCR)-based and in situ hybridization analysis.
Histopathologically, there was a lymphomatous infiltrate in the paratesticular
soft tissue, composed of a variable mixture of medium-sized to large cells with
large cytoplasm and irregular-shaped nuclei, together with blood vessel
destruction, necrosis and karyorrhexis. Immunohistochemical study revealed a high
p53 expression in neoplastic cells that showed T cytotoxic immunophenotype,
failing to express the natural killer (NK)-cell antigen CD56. A monoclonal
rearrangement of the T-cell receptor (TCR) gamma gene by a PCR technique was
demonstrated. Type-A Epstein-Barr Virus (EBV) DNA was detected by PCR-based
analysis. A combined in situ hybridization and immunohistochemical study revealed
that most cells labeled positive for EBV RNA showed immunostaining with the
CD45RO antibody. Based on the above results, the case reported was classified as
extranodal peripheral T-cell lymphoma with cytotoxic phenotype and EBV
associated. The present case does not fit neatly into any of the specific types
of peripheral T-cell lymphomas of the REAL classification, so a diagnosis of
peripheral T-cell lymphoma unspecified was made.
PMID- 10678704
TI - Glomeruloid hemangioma in POEMS syndrome shows two different immunophenotypic
endothelial cells.
AB - The case of a Japanese woman with glomeruloid hemangioma, an initial marker for
POEMS syndrome, is reported. Her cutaneous lesions were multiple and consisted of
glomeruloid hemangiomas, cherry-type capillary hemangiomas, and a mixture of
both. The specimens of glomeruloid hemangiomas were studied by paraffin section
immunohistochemistry with a large panel of antibodies and electron microscopy,
respectively. The lesions, whose size ranged from minute foci to large nodules,
were composed of anastomosing vascular channels resembling renal glomeruli and
had irregular lumina, often featuring capillaries and sinusoid-like spaces. The
vascular channels were lined by a single layer of endothelial cells, which showed
two types of cells. The capillary-type endothelium possessed large vesicular
nuclei with open chromatin and large amount of cytoplasm. The sinusoidal
endothelium possessed small basal nuclei with dense chromatin as well as scant
amount of cytoplasm. The former cells had a characteristic CD31+/CD34+/UEA
I+/CD68- phenotype. Some of these cells ultrastructurally showed intracytoplasmic
lumen formation. The latter cells had a characteristic CD31+/CD34-/UEA I-/CD68+
phenotype. The present study shows that glomeruloid hemangioma has unique
morphologic and immunologic features that differ from the traditional hemangiomas
as well as littoral cell angioma of the spleen.
PMID- 10678705
TI - Pigmented squamous cell carcinoma.
AB - Pigmented squamous cell carcinomas have been reported in the oral and ocular
mucosae, but rarely in the skin. We present a case of pigmented squamous cell
carcinoma of the forehead and review the current English literature. Pigmented
squamous cell carcinoma can be confused with pigmented basal cell carcinomas and
melanoma, especially those melanomas associated with pseudoepitheliomatous
hyperplasia and should be included in the differential diagnosis of atypical
pigmented lesions.
PMID- 10678706
TI - Generalized pruritic eruption with suprabasal acantholysis preceeding the
development of bullous pemphigoid.
AB - We report a patient who presented with a papular pruritic eruption of a 3-month
duration that histologically showed suprabasal acantholysis accompanied of an
eosinophilic inflammatory infiltrate that was consistent with the diagnosis of
Grover's disease. Later, erythematous plaques and vesicles appeared which showed
a histopathological pattern of eosinophilic spongiosis. The direct
immunofluorescence (DIF) study showed lineal IgG and C'3 at the dermal epidermal
junction which was consistent with the diagnosis of bullous pemphigoid. No anti
intercellular deposits of immunoglobulin G (IgG) or C'3 were observed. We
consider that suprabasal acantholysis may represent the early phase of bullous
pemphigoid.
PMID- 10678707
TI - Pleomorphic giant cells in basal cell carcinoma.
PMID- 10678708
TI - Cell death in pilomatricoma.
PMID- 10678709
TI - Myofibroblasts and matrix components in healing palatal wounds in the rat.
AB - In order to identify wound contraction and scar formation during palatal
mucoperiosteal wound healing in growing rats, the temporal and spatial
distribution of myofibroblasts and matrix components were determined
immunohistochemically. Myofibroblasts were found in the mucosal part of the
palatal wound tissue between 4 and 22 days, with the highest density at 8 days
post-wounding. The number of collagen type I and type III fibers gradually
increased until about 8 days postwounding, and thereafter the staining intensity
of collagen type III decreased. At 60 days post-wounding there were more
transversely oriented collagen type I fibers and less type III fibers and elastin
present in the submucosa than in normal tissue. The results suggest that in this
model wound contraction mainly takes place in the mucosa between 4 and 22 days
postwounding. Furthermore, palatal wounds made in young rats heal with distinct
scar tissue formation. Therefore, this model is useful to test the effects of
therapies that aim to reduce wound contraction and scarring after cleft palate
surgery.
PMID- 10678710
TI - Synergistic enhancement of collagenous protein synthesis by human gingival
fibroblasts exposed to nifedipine and interleukin-1-beta in vitro.
AB - Gingival overgrowth commonly occurs coincident to therapy with calcium channel
blockers. The biologic mechanism for this condition is unknown; however, many
clinicians suggest that poor oral hygiene may contribute to development of the
overgrowth. This study tests the hypothesis that collagenous protein synthesis by
gingival fibroblasts is synergistically enhanced when they are exposed to both
nifedipine (N) and the pro-inflammatory cytokine, interleukin-1-beta, a cytokine
expressed in inflamed gingiva. Human gingival fibroblasts were isolated from
biopsies of normal gingiva and cells separated into two groups. Group 1 was
exposed to media containing 0, 5, 50, or 500 pg/ml IL-1-beta, or 10(-7) M N for 7
days; Group 2 was exposed to those concentrations of IL-1-beta +10(-7) M N. [3H]
proline was added to the medium for the final 24 h. Cells and matrix were
harvested and radioactivity determined by liquid scintillation analysis. Means
(d.p.m./10(3) cells) were compared by factorial ANOVA and Scheffe comparisons.
Collagenous protein synthesis was significantly reduced by 5 pg/ml IL-1-beta +10(
7) M N and enhanced by 500 pg/ml IL-1-beta +10(-7) M N as compared to N or IL-1
beta alone. Thus, patients may be more susceptible to gingival overgrowth
coincident to nifedipine therapy as a result of the synergistic enhancement of
connective tissue synthesis by these agents.
PMID- 10678711
TI - Juvenile ossifying fibroma. An analysis of eight cases and a comparison with
other fibro-osseous lesions.
AB - Juvenile ossifying fibroma (JOF) is a well-defined clinical and histological
entity that has recently been separated from other fibro-osseous lesions,
including cemento-ossifying fibromas. Its biological behaviour is well defined,
but unexplained. Its behaviour, clinical and histological appearance, however,
bears resemblance to osteofibrous dysplasia of long bones, a lesion that in some
cases has been reported to be part of a spectrum of diseases associated with
adamantinoma, thus accounting for its variable biological behaviour. Eight cases
of JOF were examined for islands of epithelium or single epithelial cells using
immunocytochemistry. While these cases of JOF could clearly be separated from
other fibro-osseous lesions, and were histologically similar to osteofibrous
dysplasia, the absence of cytokeratin-positive cells in all cases suggests that
another reason for its biological behaviour has still to be found.
PMID- 10678712
TI - Immunolocalization of tumor necrosis factor-alpha expressing cells in recurrent
aphthous ulcer lesions (RAU).
AB - Tumor necrosis factor (TNF)-alpha is a pro-inflammatory cytokine and crucial
mediator in many aspects of immunity. Although several studies have shown that
recurrent aphthous ulcers (RAU) can be prevented by treatment that prevents the
synthesis of endogenous TNF-alpha little is known about the location and
distribution of TNF-alpha-expressing cells at disease sites. The aim of the
present work is, therefore, to investigate TNF-alpha and its cellular
distribution in RAU lesions compared with those in induced oral traumatic ulcers
(TUs). Twelve biopsies of RAU lesions of oral mucosa were obtained from 12
patients with RAU. They were compared to a control group consisting of ten
samples of induced TUs. All samples were analyzed for TNF-alpha expression by
using monoclonal mouse anti-human TNF-alpha antibody in avidin-biotin-peroxidase
complex (ABC) staining. Results were quantified by a semi-automatic VIDAS image
analysis system. TNF-alpha immunoreactivity was contained mainly in
monocyte/macrophages and lymphocytes within the mononuclear inflammatory
infiltrates. TNF-alpha was often seen in mast cells and vascular endothelial
cells in connective tissue lateral to the inflammatory infiltrates.
Interestingly, 32%-60% of the mononuclear cells were found to be TNF-alpha
immunoreactive in RAU lesions. TNF-alpha containing cells were more numerous in
aphthae (188+/-46 cells/0.2 mm2) compared with controls (52+/-14 cells/0.2 mm2,
P<0.001). These findings suggest that RAU lesions are characterized by high
expression of TNF-alpha. Because such expression occurred in the mononuclear
inflammatory cells, mast cells and vascular endothelial cells, TNF-alpha, which
is a major inflammatory mediator, may contribute to the activation and
recruitment of leukocytes that are found in RAU lesions.
PMID- 10678713
TI - Lack of association between Streptococcus oralis and recurrent aphthous
stomatitis.
AB - In the present study, the potential involvement of Streptococcus oralis in the
aetiology of recurrent aphthous stomatitis (RAS) was investigated using the
polymerase chain reaction (PCR). Biopsies from 28 RAS patients were analysed, in
addition to 20 oral lichen planus (OLP) and 13 normal biopsies that were used as
controls. PCR was carried out using a primer pair that targets the D-alanine:D
alanine ligase gene and detects DNA from both S. oralis and the closely related
species Streptococcus mitis. Discrimination between these two species was
achieved by digestion of PCR products with the restriction endonucleases HaeIII
and HindIII, which both give distinct restriction profiles for each species. S.
oralis DNA was detected in 8 of 28 (29%) RAS samples, 10 of 20 (50%) OLP samples
and 6 of 13 (46%) normal samples. These results suggest that S. oralis is not of
primary aetiological significance in RAS.
PMID- 10678714
TI - Argyrophilic nucleolar organizer regions (AgNORs) in mucosal epithelium under
experimental denture bases in rats.
AB - The purpose of this study was to evaluate changes in the argyrophilic nucleolar
organizer region (AgNOR) counts in mucosal epithelium induced by continuous or
intermittent compressive pressure exerted through experimental denture bases and
to examine the relationships between the AgNOR count, histopathological changes
and the intensity of the pressure under denture bases. Continuous or intermittent
compressive pressure exerted through the denture bases was applied to the hard
palate of the molar region in rats. A morphometric analysis of AgNORs was
performed in denture-supporting tissue 3 days and 1, 2, 4, 8, 12 and 20 weeks
after the denture insertion. From the results of this study, it was found that
non-pressure contact of the denture bases with palatal tissues did not change the
AgNOR count. The AgNOR count was decreased by continuous or intermittent
compressive pressure, and then recovered to almost the same level as with the non
pressure contact at 20 weeks following a decrease of the pressure. The AgNOR
counts in the epithelium under the denture bases were revealed to be related to
the histopathological changes in the denture-supporting tissues and the intensity
of the pressure under the denture bases.
PMID- 10678715
TI - Hepatitis C virus-associated oral lichen planus: no influence from hepatitis G
virus co-infection.
AB - There is a variable geographic distribution in the prevalence of hepatitis C
virus (HCV)-related oral lichen planus (OLP), which appears unrelated to either
HCV genotype or HCV epidemiology. The present study investigated whether
hepatitis G virus (HGV) co-infection may be a feature of patients with HCV
related OLP, which might explain these phenomena. HGV co-infection was detected
in 6 of 39 Italian patients with HCV-related OLP, but the presence of HGV did not
influence the clinical presentation of OLP. It is concluded that HGV co-infection
is unlikely to influence the clinical detection of HCV-related OLP.
PMID- 10678716
TI - Clear cell odontogenic tumor in the mandible: report of a case with duct-like
appearances and dentinoid induction.
AB - A case of clear-cell odontogenic tumor with unusual histological features is
presented. A 61-year-old Japanese man was admitted because of swelling of the
left premolar-molar region of the mandible. Radiological examination revealed a
multilocular radiolucency with irregular margins. Histological examination of the
resected specimen showed infiltrative proliferation of both clear and
eosinophilic cells into the adjacent soft tissue without encapsulation,
suggesting the malignant potential of the tumor. The tumor cells sporadically
formed cystic lesions. In addition, several tumor cell nests showed duct-like
characteristics, and many eosinophilic dentin-like structures were attached to
the tumor cell nests, suggesting the potential for epithelial-mesenchymal
induction. Histochemically, the clear tumor cells possessed cytoplasmic glycogen
granules. Both clear and eosinophilic tumor cells showed positive
immunoreactivities for cytokeratin 19, epithelial membrane antigen and filaggrin,
indicating an odontogenic epithelial origin.
PMID- 10678717
TI - Food allergy: when and how to perform oral food challenges.
AB - In many situations, the diagnosis of food allergy rests simply upon a history of
an acute onset of typical symptoms, such as hives and wheezing, following the
isolated ingestion of a suspected food, with confirmatory laboratory studies of
positive prick skin tests or Radioallergosorbent tests. However, the diagnosis is
more complicated when multiple foods are implicated or when chronic diseases,
such as asthma or atopic dermatitis, are evaluated. The diagnosis of food allergy
and identification of the particular foods responsible is also more difficult
when reactions are not mediated by IgE antibody, as is the case with a number of
gastrointestinal food allergies. In these latter circumstances, well-devised
elimination diets followed by physician-supervised oral food challenges are
critical in the identification and proper treatment of these disorders. Because
childhood food allergies to common allergenic foods such as milk, egg, wheat and
soy are usually outgrown, oral food challenges are also an integral part of the
long-term management of these children.
PMID- 10678718
TI - Different serum interleukin-12 and sCD30 levels in food- and pollen-sensitized
children.
AB - It has been proposed that a down-regulation of interleukin (IL)-12 and interferon
(IFN)-gamma might be related to susceptibility to allergy in early life. The aim
of this study was to assess serum IL-12 levels in food-sensitized and pollen
sensitized children and to compare these with another activation marker, sCD30.
Twenty children with pollen allergy and 22 food-sensitized children were
included. The diagnosis of immunoglobulin (Ig)-E-mediated allergy, suggested by
clinical symptoms, was based on skin-prick tests, serum IgE antibodies and total
IgE levels. Samples from 24 non-allergic children were used as controls. IL-12
and sCD30 levels were measured by ELISA. It was found that pollen-sensitized
patients had normal IL-12 and higher sCD30 levels than controls (114 vs. 63 U/ml,
p = 0.028), but, surprisingly, food-sensitized infants showed normal sCD30 and
increased serum IL-12 levels (323 vs. 118 pg/ml, p = 0.0001). No differences were
found in patients suffering from asthma or allergic dermatitis. Levels of sCD30
and IL-12 determined in May showed a strong correlation with those obtained in
November. Interleukin-12 and IgE levels had an inverse correlation (r = -0.494, p
= 0.0001) whereas no correlation was found between sCD30 and IgE. Age had a
strong negative influence on IL-12 levels in allergic (Z = 4.834, p < 0.0005) and
in normal children (Z = 3.00, p < 0.002); by contrast, sCD30 levels were not
significantly age-dependent. When IL-12 levels from the food-allergy group were
compared with those from normal controls younger than 4 years of age, the
difference remained significant (p = 0.001), ruling out an age-bias. The
conclusions made in this study were that serum IL-12 and sCD30 showed different
behaviors in children with food or pollen allergy. We found IL-12 and sCD30
levels in pollen-allergic patients that agree with the classical T-helper (Th)
1/Th2 paradigm of allergy. In contrast, serum IL-12 levels were increased in food
sensitized children, suggesting a different immunologic pathogenesis.
PMID- 10678719
TI - Infants colonized with enterotoxin-producing staphylococci at 3 months display a
decreased frequency of interferon-gamma-producing CD45RO lymphocytes upon
stimulation with staphylococcal enterotoxin A at birth but not at 6 months of
age.
AB - The aim of the study was to elucidate the relationship between the cytokine
response to staphylococcal enterotoxin A (SEA) at birth and subsequent
staphylococcal colonization in the first months of life. In a cohort of 45
newborns, cord blood lymphocytes were stimulated with SEA (10 ng/ml) in vitro, re
stimulated with PMA (phorbol myristate acetate) and ionomycin at day 3 and
assessed for CD45RO expression and cytokine generation by flow cytometry. The
infants were classified into three groups according to nasal staphylococcal
colonization and enterotoxin generation at 3 months: There were 16 infants with
either no colonization or non-enterotoxin-producing staphylococci, 16 infants
with enterotoxins B, C, D and E, and 13 infants colonized with SEA-producing
staphylococci. At birth, the group without subsequent colonization displayed a
significantly higher frequency of CD45RO-positive interferon-gamma-producing
cells (1.7%; range 0.0-9.3%) in comparison to the SEA-positive group (0.1%; range
0.0-0.4%) and also to the group positive for other enterotoxins (0.50%; range 0.0
2.5%). Comparable but less pronounced results were found for interleukin-5 but
not for interleukins 2 and 4. At 6 months, no differences in cytokine generation
were detected between the three groups. The results provide evidence that a non
specific immunologic immaturity at birth is a risk factor for early bacterial
colonization. Furthermore, it is remarkable that this immaturity is similar to
that seen in infants destined to be atopic with respect to disequilibrium of
interferon-gamma to interleukin-4 generation. Thus the link between early
staphylococcal colonization and subsequent atopy requires further investigation.
PMID- 10678720
TI - Mononuclear cell reactivity to food allergens in neonates, children and adults.
AB - A model of antigen-specific T-cell proliferative responses based on reciprocal
patterns of responses to dietary and inhalant allergens has been suggested, the
former being frequent in infancy but rare in adults, whereas the latter are
preserved and expand between infancy and adulthood. We have evaluated the age
related variations of mononuclear cell reactivity to food allergens. The cord
blood mononuclear cells (CBMC) of 30 neonates without family history of atopy and
the peripheral blood mononuclear cells (PBMC) of 20 healthy children and of 40
healthy adults were stimulated in vitro with beta-lactoglobulin (BLG) or
ovalbumin (OVA) and the cultures were harvested after 7 days. Neonates, children
and adults were compared for the percentages of positive responses and for the
magnitude of response. Adult subjects showed significantly lower percentages of
positive responses and reduced magnitude of response than those observed in
neonates and children either in BLG or in OVA cultures. We have not observed a
decrease of food allergen mononuclear cell reactivity between neonates and
children for the frequency of positive responses. The magnitude of response of
neonates was significantly lower than that of children in BLG cultures. Our
results seem to confirm the loss of mononuclear cell reactivity to food allergens
in adult age. However, other reports show conflicting data. We suggest that a
rigorous standardization of the methodological steps of in vitro mononuclear cell
stimulation with allergen is necessary.
PMID- 10678721
TI - Cutaneous lymphocyte-associated antigen expression in children with atopic
dermatitis and non-atopic healthy children.
AB - Cutaneous lymphocyte-associated antigen (CLA) is a cell surface glycoprotein
which has been implicated in the homing of lymphocytes to cutaneous sites. It is
postulated to play an important role in T-cell migration to skin in atopic
dermatitis; however, the expression of CLA in both normal children and children
with atopic dermatitis has not been extensively studied. If CLA expression on T
cells were important in the traffic of lymphocytes to atopic dermatitis skin
lesions, it might be expected that the proportion of CLA+ T cells in unstimulated
peripheral blood from children with atopic dermatitis would be elevated. We have
examined the proportion of CLA+ T cells in children with atopic dermatitis and
non-atopic age-matched controls. The proportion of CLA+ T cells in non-atopic
children was highly associated with and increased with increasing age (r = 0.88,
p < 0.001). There was no difference between the proportion of T cells expressing
CLA in the unstimulated peripheral blood mononuclear cells from children with
severe (p = 0.18) or with mild/moderate (p = 0.3) atopic dermatitis and age
matched non-atopic controls. Despite this, children with atopic dermatitis did
show evidence of perturbation of CLA expression, as unlike the non-atopic
children the proportion of CLA+ T cells in the atopic children did not correlate
with age. These findings suggest that while CLA expression may play a role in
atopic dermatitis, other as yet undefined surface markers are likely to
principally determine the migration of T cells to skin in atopic dermatitis.
PMID- 10678722
TI - Dust mite allergens are carried on not only large particles.
AB - The major obstacle for the successful measurement of airborne mite allergen is
its very low concentration in the absence of vigorous disturbance. The aim of
this study was to investigate the particle size distribution of group 2 dust mite
allergen using an amplified ELISA system. Air sampling was performed using an
Andersen sampler placed in the centre of the room, 1.2 m above floor level
(airflow rate 28.7 l/min). This is a multistage, multiorifice cascade impactor
that is comprised of six stages. Any particle greater that 4.7 microm should
impact on stages 1 and 2, whilst stages 3-6 measure the predominantly respiratory
range. The sampling was carried out for 30 min after 15 min of vigorous
disturbance (vacuum cleaning without bag and filter). Der p 2 was measured using
mAb-based ELISA with the AmpliQ amplification kit (Dako Ltd, Cambridgeshire, UK).
The sensitivity was increased 15-fold as compared with standard assay, bringing
the level of detection to 300 pg/ml. The majority of airborne Der p 2 (79.4%) was
carried on large particles (> 4.7 microm). However, a small but important
proportion of airborne Der p 2 (20.6%) was associated with small particles (1.1
4.7 microm). It is worth noting that all the levels measured were below the
detection limit of standard assay. In conclusion, we have shown that using an
amplification system, airborne mite allergen previously undetectable owing to its
low concentration can be quantified. Group 2 dust mite allergen is carried not
only on large particles. A small, but potentially significant proportion of this
airborne allergen is associated with small particles which, when inhaled, may
penetrate deep into the human respiratory tract.
PMID- 10678723
TI - Prevalence of asthma and allergic diseases in primary school children in Ankara,
Turkey: two cross-sectional studies, five years apart.
AB - The prevalence of allergic diseases is reported to have increased worldwide. Two
questionnaire surveys, five years apart, were conducted to evaluate the trend of
prevalence rates and possible risk factors among primary school children in
Ankara, Turkey. A previous survey in 1992 revealed the lifetime prevalences of
asthma, wheezing, allergic rhinitis and atopic dermatitis were 17.4%, 23.3%, 28%
and 6.1%, and the prevalences for the last 12 months were 8.3%, 11.9%, 15.4% and
4%, respectively. The survey was repeated with the same questionnaire in the same
age group (6-13 years) of the same school in May 1997. The parents of 358 boys
and 380 girls completed the questionnaire. The lifetime and last 12 months'
prevalences of asthma, wheezing, rhinitis and atopic dermatitis were 16.8%,
22.5%, 18.7%, 6.5%, and 9.8%, 13.3%, 14.1%, 4.3%, respectively. There was a
significant change only for the lifetime prevalence of rhinitis (p < 0.001). The
rate of indoor smoking had declined from 73.9% to 64%, and pet ownership had
risen from 7.9% to 22.9% (p < 0.001 for both). Atopic family history was the most
prominent risk factor for all types of allergic disorders. Male gender was a
significant risk factor for current asthma and wheezing [odds ratio (OR) = 1.80
and 1.59; 95% confidence intervals (CI) = 1.09-2.98 and 1.01-2.48, respectively],
and passive smoking affected the occurrence of allergic rhinitis (OR = 1.84; CI =
1.13-3.00). The prevalence rates of allergic diseases among primary school
children in Ankara stabilized during a 5-year period for all diseases other than
allergic rhinitis. However, there are changing behavior patterns, i.e. indoor
smoking and keeping pet animals, which that may have affected these rates.
PMID- 10678724
TI - Use of pocket-sized turbine spirometer in monitoring exercise-induced
bronchospasm and bronchodilator responses in children.
AB - For field studies of asthma, portable hand-held pulmonary function testing
devices are required. Other than for peak flow measurements, little has been done
to validate their use in children. Fifty children aged 5-15 years having asthma
symptoms were examined using an exercise challenge (8 min free running outdoors)
and a bronchodilation test (salbutamol inhalation at a dose of 0.15 mg/kg).
Pulmonary function was measured with a turbine spirometer, with a Wright peak
flow meter (WPEF) and with a flow-volume spirometer (FVS). A fall of 15% or more
in peak expiratory flow associated with wheezing or cough was considered
diagnostic for bronchial hyper-responsiveness to exercise (BHRE). A rise of 15%
or more from baseline in peak expiratory flow after salbutamol inhalation was
considered as a positive bronchodilator response (BDR). BHRE was present in 16
children (32%). Using the limit of a 15% or greater fall in FEV1, turbine
spirometry identified 12 as BHRE-positive and no additional cases, giving a
sensitivity of 75% and a specificity of 100%. The turbine spirometer showed lower
FEV1 values than the FVS, the difference increasing with airway obstruction. BDR
was positive in eight children (16%). Using the limit of a 10% or greater rise in
FEV1, turbine spirometry was positive in six cases. FEV1 measured by turbine
spirometry could not be used interchangeably with conventional FVS. However, the
turbine spirometer offers the possibility to measure FEV1 repeatedly in field
conditions, such as during exercise challenges outdoors.
PMID- 10678725
TI - Allergy to an occupational allergen (Sapelli wood) in a child.
AB - The case is presented of a child who developed rhinoconjunctivitis, angioedema
and asthma by sensitization to Sapelli wood, which was used in his father's
carpentry. Positive skin-prick test, high levels of specific immunoglobulin E by
ELISA and a positive conjunctival challenge test suggest a type I
hypersensitivity mechanism to this wood. This is the first case report of
sensitization to Sapelli wood and it confirms that occupational allergen exposure
as Sapelli wood may also cause sensitization in a child.
PMID- 10678726
TI - The clinical interpretation of skin prick tests (SPT)
PMID- 10678727
TI - Anatomical bases for paravertebral anesthetic block: fluid communication between
the thoracic and lumbar paravertebral regions.
AB - An injection of a local anesthetics in the paravertebral region produces an
analgesic field on the same side of the body, a paravertebral block. One point in
question about this block is whether the local anesthetic spreads from the
thoracic to the lumbar level of the paravertebral region. The purpose of this
study was to find how the anesthetic fluid traveled to the lumbar paravertebral
region, if at all. Twelve cadavers were used in this study. 15 ml of crimson dye
was injected into the paravertebral region at the 11th thoracic level. The
viscerae were removed so that we could examine the dye spread. While the crimson
dye spread in the endothoracic fascia posterior to the parietal pleura, it also
spread downward in the fascia mostly along the splanchnic nerves. At the upper
surface of the diaphragm the dye spread laterally in the fascia, and entered the
abdominal cavity through the medial and lateral arcuate ligaments. In the
abdominal cavity, the dye was found to have spread so widely in the transversalis
fascia that the subcostal, iliohypogastric, ilioinguinal, genitofemoral, lateral
femoral cutaneous and femoral nerves were involved. We concluded that the dye in
the thoracic paravertebral region can enter the abdominal cavity through the
medial and lateral arcuate ligaments. This study explained possible fluid
communication between the thoracic and lumbar paravertebral regions and confirmed
our former clinical observations. The result is important for the future clinical
application of paravertebral anesthesia.
PMID- 10678728
TI - High and low lateral approaches to the popliteal artery.
AB - Using a series of 20 dissections and two anatomic transverse sections of a lower
limb, the authors investigated the lateral approaches to the popliteal artery.
The high lateral approach (above the knee) is not very aggressive and gives
access to the retro-genicular part of the popliteal artery. After cutaneous and
fascial incision, a simple gap between the vastus lateralis and biceps femoris
mm. allows easy exposure of the popliteal vessels after backward retraction of
the sciatic nerve. The low lateral approach to the artery (below the knee) is
very aggressive for the vessels, nerves, and ligaments of the area. It involves
the resection of the upper fourth of the fibula and the isolation and protection
of the common peroneal nerve Nevertheless, these lateral approaches must be known
and used when classic approaches (medial and posterior) are impossible.
PMID- 10678729
TI - Topoanatomic relations of the ophthalmic artery viewed in four horizontal layers.
AB - In the present paper we have studied the gross anatomy of the ophthalmic artery
in 200 human cadaver dissections viewed in four horizontal layers. The ophthalmic
artery can be divided into the origin, intracranial, intracanalicular and
intraorbital parts. The most common origin of the artery was from the medial half
of the anterior side of the internal carotid artery (ICA) in its upper curve
(52%), followed by the medial half of the superior side (44%), and in only 4%
from the medial side of the upper curve of the ICA. We have examined the
topographic anatomy of the ophthalmic artery in detail, and found a rare
anastomosis of the ophthalmic artery with the frontal branch of the middle
meningeal artery.
PMID- 10678730
TI - Biomechanical behaviour in vitro of the spine and lumbosacral junction.
AB - Six fresh human specimens extending from the 9th thoracic vertebra (T9) to the
pelvis were used to study the biomechanical behaviour of the long lumbopelvic
segments, including mobility of the sacrum. The loads were applied at T9 using
pure couples up to 5 Nm. The displacements were measured by an optoelectronic
method (VICON 140). Stress-displacement curves were obtained for the three
angular components of the vertebra studied according to the plane of the
principal stresses and of the two other planes corresponding to the coupled
mobilities. Mobility decreased from T9 to the sacrum. There was mobility of the
sacrum in relation to the pelvis in flexion, with a mean of 1.28 degrees (0.5 to
2.8 degrees); 3 sacrums showed a mobility of the order of one degree for
torsional stresses. There was no sacral mobility during stresses in lateral
flexion. The use of this experimental protocol with low mechanical stresses
should allow the evaluation of long osteosyntheses extending to the sacrum.
PMID- 10678731
TI - A new radiographic method for evaluation of the position of the carpus in the
coronal plane: results in normal subjects.
AB - The methods used to quantify pathological variations of the position of the
carpus in the coronal plane, mainly ulnar translation of the carpus from trauma
or rheumatoid disease, are often difficult to use in arthritic or postsurgical
wrists; moreover, they require the measurement of the whole length of the third
metacarpal. The aim of this study was to determine a reliable and easy-to-use
index to analyse the position of the carpus in the coronal plane. One hundred PA
X-rays of normal wrists were studied, of which 56 presented with a medial hamate
facet of the lunate. An index of position of the carpus in the coronal plane is
defined as the ratio of orthogonal distances from [1] the most medial point of
the distal radius and [2] the most medial point of the capitate to the long axis
of the radius: its mean value being 1.06 (+/- 0.13) in this series of normal
wrists. The index is influenced by the presence of a medial hamate facet of the
lunate, but is not dependent on the ulnar head and radial styloid process, nor on
the length of the third metacarpal. To help to define the usefulness of the index
in quantifying the different types of ulnar carpal translations in clinical
practice, further studies are required.
PMID- 10678732
TI - Importance of elliptic Fourier methods for morphometry of complex outlines:
application to the distal human femur.
AB - The purpose of this technical note is to present an automatic procedure of shape
characterisation using new developments in elliptical Fourier methods combined
with image analysis techniques. It was applied, as an example, to the outline of
the distal extremity of the distal human femur in inferior axial view. This
outline was automatically extracted and characterised by an ordered series of
harmonics, each harmonic being described by four new parameters called elliptical
descriptors. Step by step reconstructions of outlines using an increasing number
of harmonics were than performed. The simultaneous study of the elliptic
descriptors and of the step by step reconstructions allowed a considerably easier
geometric and morphologic interpretation of the harmonic contributions than
classically. The main morphologic features of the distal femur (lateral and
medial condyles, intercondylar fossa, lateral and medial borders of the articular
surface, and patellar groove) were mainly described by the first seven harmonics.
These new developments in elliptic Fourier methods open interesting perspectives
for the study of complex outlines, providing an accurate individual morphologic
characterisation, and thus the possibility of polymorphic analysis.
PMID- 10678733
TI - The neurovascular and muscular anomalies of the gluteal region: an atypical
pudendal nerve.
AB - In two cases, one male and one female, muscular anomalies together with
neurovascular variations were encountered in the gluteal regions, in each cadaver
on the same side. In the male cadaver, there was a double piriformis muscle and
high division of the sciatic nerve. In the female cadaver, in addition to these
anomalies, the superior and inferior gemelli and obturator internus muscles, and
the internal pudendal vessels and pudendal nerve passed behind the sacrotuberous
ligament. Although duplication of the piriformis and high division of the sciatic
nerve have been reported previously, to the best of our knowledge the other
anomalies have not yet been reported. The abnormal relationship of the internal
pudendal vessels and the pudendal nerve with the sacrotuberal ligament, as in our
case, may cause venous congestion, arterial obstruction, dysfunction of penile
erection and perineal neuralgia. These anomalies of the gluteal region are not
only of academic interest, but may be of practical importance for surgical
intervention in the area.
PMID- 10678734
TI - Double gluteus maximus muscle with associated variations in the gluteal region.
AB - We report bilateral muscular and neurovascular anomalies of the gluteal region in
a cadaver. On the right side, the gluteus maximus muscle had two parts, one of
which was fibrous and the other muscular. In addition, there were duplicated
piriformis muscles and high division of the sciatic nerve. The common peroneal
nerve passed between the two parts of the piriformis muscle, and the tibial nerve
emerged from under the lower piriformis muscle (infrapiriform foramen). At the
same time the internal pudendal vessels and pudendal nerve passed over the
sacrotuberous ligament on the left side. The double piriformis muscles and high
division of the nerve are known as an anomaly which is believed to cause a nerve
compression syndrome called the syndrome of the piriformis muscle. To the best of
our knowledge anomalies of the gluteus maximus muscle and pudendal structures
have not yet been reported. This complex anomaly should be kept in mind in
connection with intramuscular injections of the gluteal region, the piriformis
syndrome, and the surgery of this region.
PMID- 10678735
TI - Role of hip abduction in the kinetics of the thoracic and lumbar spine.
AB - The motion of the thoracic and lumbar spine segments was analysed by mean of the
skin landmarks method in 14 volunteers (7 males, 7 females). The results
demonstrated that there was no significant difference between men and women and
there was either facilitation or limitation of the motion of the characteristic
landmarks of spinal segments during trunk motion in perpendicular planes. The
mobility of spinal segments was associated with pelvic girdle motion in order to
obtain the planned amplitude, and varied with hip joint abduction. The analysis
of the precise mechanisms of relaxing or stretching of the pelvivertebral musculo
ligamentous structures constitutes a large field of investigation that
necessitates the study of other lower limb postures and the use of robotic
techniques.
PMID- 10678736
TI - Physiological time series: distinguishing fractal noises from motions.
AB - Many physiological signals appear fractal, in having self-similarity over a large
range of their power spectral densities. They are analogous to one of two classes
of discretely sampled pure fractal time signals, fractional Gaussian noise (fGn)
or fractional Brownian motion (fBm). The fGn series are the successive
differences between elements of a fBm series; they are stationary and are
completely characterized by two parameters, sigma2, the variance, and H, the
Hurst coefficient. Such efficient characterization of physiological signals is
valuable since H defines the autocorrelation and the fractal dimension of the
time series. Estimation of H from Fourier analysis is inaccurate, so more robust
methods are needed. Dispersional analysis (Disp) is good for noise signals while
bridge detrended scaled windowed variance analysis (bdSWV) is good for motion
signals. Signals whose slopes of their power spectral densities lie near the
border between fGn and fBm are difficult to classify. A new method using signal
summation conversion (SSC), wherein an fGn is converted to an fBm or an fBm to a
summed fBm and bdSWV then applied, greatly improves the classification and the
reliability of H, the estimates of H, for the times series. Applying these
methods to laser-Doppler blood cell perfusion signals obtained from the brain
cortex of anesthetized rats gave H of 0.24+/-0.02 (SD, n=8) and defined the
signal as a fractional Brownian motion. The implication is that the flow signal
is the summation (motion) of a set of local velocities from neighboring vessels
that are negatively correlated, as if induced by local resistance fluctuations.
PMID- 10678737
TI - Heart fatty acid binding protein and cardiac troponin T plasma concentrations as
markers for myocardial infarction after coronary artery ligation in mice.
AB - Ligation of the main left coronary artery in mice serves as a model for
myocardial infarction (MI). We tested whether plasma concentrations of heart-type
fatty acid-binding protein (H-FABP) and/or cardiac troponin T (cTnT) discriminate
between infarcted and sham-operated mice and allow estimation of infarct size.
Mice were subjected to coronary artery ligation or sham surgery and release
curves of H-FABP and cTnT were determined. At 4 h after surgery the mean (+/-SD)
H-FABP plasma concentration was 461+/-134 microg/l (n=10) in MI and 185+/-51
microg/l (n=6; P<0.001) in sham-operated mice. By 24 h after surgery H-FABP
levels had returned to normal in both groups. cTnT plasma concentrations
increased up to 48 h after MI to 13.5+/-6.2 microg/l (n=6; P<0.001) compared with
0.031+/-0.063 microg/l (n=7) in sham-operated mice. Linear regression analysis
revealed a significant correlation between plasma H-FABP at 4 h and infarct size
assessed 7 days after surgery. Plasma cTnT did not correlate significantly with
infarct size. In conclusion, plasma cTnT concentration at 48 h after infarction
can be used to distinguish MI from sham mice, whereas H-FABP concentration at 4 h
can be used for stratification of animals according to infarct size.
PMID- 10678738
TI - Modulation of cloned skeletal muscle sodium channels by the scorpion toxins Lqh
II, Lqh III, and Lqh alphaIT.
AB - The scorpion alpha-toxins Lqh II, Lqh III, and Lqh alphaIT from Leiurus
quinquestriatus hebraeus are representatives of typical alpha-toxins, specific
for either mammals (Lqh II) or insects (Lqh alphaIT), and alpha-like toxins (Lqh
III) which act on both mammals and insects. For a comparative study of the
effects of these toxins on mammalian sodium channels we stably expressed rat
skeletal muscle sodium channel alpha subunits (microI) in HEK 293 cells and
measured Na+ currents in the whole-cell patch-clamp mode. The alpha- and alpha
like toxins strongly slowed down channel inactivation with a half-maximal effect
at 1.4 nM (Lqh II), 5.4 nM (Lqh III), and 0.5 nM (Lqh alphaIT). The recovery from
fast inactivation was accelerated by all toxins with the potency sequence: Lqh
II>Lqh alphaIT>Lqh III. The voltage dependence of inactivation and recovery from
inactivation were reduced while the threshold for activation was only slightly
shifted by approximately equal to 10 mV without altering the slope factors,
suggesting uncoupling of the impaired inactivation from the activation. The
toxins induced an increase in peak inward current, which was accounted for by an
increased maximal open-channel probability. Although all three toxins induced
similar modifications of the channel properties, their kinetics of association
and dissociation were very different. Between -140 and -80 mV toxin association
was not voltage dependent. In 100 nM toxin the association time constants were:
1.3 s (Lqh II), 20 s (Lqh III), and 3.8 s (Lqh alphaIT). At positive voltages the
toxin dissociated from the channel; at +100 mV the dissociation time constants
were 30, 321, and 135 ms, respectively. In contrast to the association,
dissociation was voltage dependent with a similar slope of about 12 mV per e-fold
change for all three toxins. The strong differences in the association and
dissociation kinetics of these toxins may identify them as members of different
scorpion alpha-toxin subgroups.
PMID- 10678740
TI - Endogenous nitric oxide attenuates erythropoietin gene expression in vivo.
AB - This study aimed to investigate the role of endogenous nitric oxide (NO) in
erythropoietin (EPO) gene expression in mice in vivo. For this purpose EPO mRNA
was semiquantitated by ribonuclease protection assay in livers and kidneys of
three groups of mice: wild-type (wt), endothelial NO-synthase (NOS) knockout mice
(eNOS-/-), and wt treated with the NOS inhibitor N(G)-nitro-L-arginine methyl
ester (50 mg x kg(-1) x day(-1)) for 4 days (wt+L-NAME). EPO gene expression was
stimulated by normobaric hypoxia (8% O2) or by 0.1% carbon monoxide (CO)
inhalation for 4 h each, or by intraperitoneal injection of 60 mg/kg cobaltous
chloride (CoCl2) for 6 h. Renal EPO mRNA in wt increased 12-, 40-, and 13-fold
over normoxic levels in response to hypoxia, CO and CoCl2 respectively. EPO mRNA
was detectable in the livers only after CO exposure. Renal and hepatic EPO gene
expression in wt+L-NAME appeared moderately increased relative to wt with a
maximal 2.5-fold enhancement after CO exposure. EPO mRNA levels in eNOS-/-
mirrored those of wt+L-NAME, but the effects were less prominent. Our data
suggest that endogenous NO attenuates EPO gene expression in mice. This effect is
dependent on the rate of EPO gene induction.
PMID- 10678741
TI - Structural and cellular adaptation of duodenal iron uptake in rats maintained on
an iron-deficient diet.
AB - Iron deficiency induced in rats maintained on a commercial diet with a low iron
content has been used to investigate adaptive mechanisms that enhance duodenal
iron uptake. These adaptive changes have been divided into those that result from
changes in villus surface area (structural adaptation) and those that reflect
changes in the way individual enterocytes express iron transport function
(cellular adaptation). Cellular adaptation was assessed by carrying out
microdensitometry of autoradiographs prepared from duodenal tissue previously
incubated for 5 min in 200 micromol/l 59Fe2+-ascorbate. Structural adaptation was
studied by performing image analysis of microdissected and sectioned villi.
Cellular adaptation involved increased iron uptake by enterocytes present in the
lower villus. Thus iron deficiency resulted in a threefold enhanced expression of
uptake in the lower 100 microm villus (3.9+/-2.4 versus 12.6+/-1.5 arbitrary
units, P<0.001). Maximal uptake was reached in the upper region of both control
and iron-deficient villi, but iron deficiency had no effect on cellular uptake at
this part of the villus. Structural adaptation involved the lengthening (+16%,
P<0.05) and broadening (+14%) of villi in the duodenum of iron-deficient rats.
The resultant expansion in villus area caused a further increase in uptake that
was mostly expressed in the upper villus. Maximal uptake corrected for structure
occurred in the middle third of villi from control and iron-deficient rats.
Cellular plus structural adaptation produced a twofold increase in iron uptake.
More than half of this effect was caused by changes in villus structure.
[3H]Thymidine labelling experiments revealed a slightly earlier expression of
enterocyte iron uptake in iron deficiency.
PMID- 10678739
TI - Calcium, ATP and nuclear pore channel gating.
AB - Nuclear envelope (NE) cisternal Ca2+ and cytosolic ATP are required for nuclear
pore-complex-(NPC-) mediated transport of DNAs, RNAs, transcription factors and
other large molecules. Isolated cardiomyocyte nuclei, capable of macromolecular
transport (MMT), have intrinsic NPC ion channel behavior. The large ion
conductance (gamma) activity of the NPC channel (NPCC) is blocked by the NPC
monoclonal antibody mAb414, known to block MMT, and is also silenced during
periods of MMT. In cardiomyocytes, neither cytosolic Ca2+ nor ATP alone directly
affects NPCC gating. To test the role of Ca2+ and ATP in NPCC activity, we
carried out the present patch-clamp study with the pipette attached to the outer
NE membrane of nuclei isolated from cultured Dunning G prostate cancer cells. Our
investigations demonstrate that in these isolated nuclei neither cytosolic Ca2+
nor ATP alone directly affects NPCC gating. However, when simultaneously applied
to the bath and pipette, they transiently silence NPCC activity through
stimulation of MMT by raising the Ca2+ concentration in the NE cisterna
([Ca2+]NE). Our fluorescence microscopy observations with nuclear-targeted
macromolecular fluorochromes (B-phycoerythrin and plasmid for the enhanced green
fluorescence protein EGFP, pEGFP-C1) and with FITC-labeled RNA support the view
that channel silence accompanies MMT. Repeated Ca2+ loading of the NE with Ca2+
and ATP, after unloading with 1-5 microM inositol 1,4,5-trisphosphate (IP3),
thapsigargin (TSG) or 5 mM BAPTA or EGTA, failed to affect channel gating. This
result indicates that other factors are involved in this phenomenon and that they
are exhausted during the first cycle of NE Ca2+ loading/unloading--in agreement
with current theories of NPC-mediated MMT. The results explain how Ca2+ and IP3
waves may convert the NE into an effective Ca2+ barrier and, consequently, affect
the regulation of gene activity and expression through their feedback on MMT and
NPCC gating. Thus, [Ca2+]NE regulation by intracellular messengers is an
effective mechanism for synchronizing gene activity and expression to the
cellular rhythm.
PMID- 10678742
TI - Lithium activates mammalian Na+/H+ exchangers: isoform specificity and inhibition
by genistein.
AB - Replacement of external NaCl with LiCl induced cytoplasmic alkalinization in CCL
39 cells and rat L6 myoblasts expressing the endogenous Na+/H+ exchanger isoform
NHE1. This Li+-induced alkalinization is due to activation of the Na+/H+
exchanger because it was completely inhibited by 100 microM
ethylisopropylamiloride (apparent Kd=1 microM) and because it did not occur in
exchanger-deficient PS120 cells. The effect of Li+ was not mimicked by Na+, K+,
Cs+ and choline+. Li+ caused cytoplasmic alkalinization in PS120 cells expressing
NHE1 or NHE2, but not NHE3, when Li+ was added to cells at a concentration high
enough to saturate their external transport sites as predicted from Li+
affinities. Li+ did not induce phosphatidylinositol (PI) turnover or
intracellular Ca2+ mobilization. Li+-induced alkalinization was not affected by
protein kinase C down-regulation, loss of glycogen synthase kinase 3beta caused
by antisense oligonucleotide treatment, or pretreatment with calphostin C,
pertussis toxin, MEK inhibitor PD98059 and PI3-kinase inhibitor LY294002.
However, it was markedly suppressed by the tyrosine kinase inhibitor genistein
(10 microM). Thus, externally added Li+ activates NHE1 and NHE2 via a mechanism
possibly involving a tyrosine kinase, causing an increase in cytoplasmic pH that
could potentially affect various cell functions.
PMID- 10678743
TI - Developmental changes in chemoreceptor nerve activity and catecholamine secretion
in rabbit carotid body: possible role of Na+ and Ca2+ currents.
AB - In order to better understand the post-natal increase in peripheral chemoreceptor
responsiveness to hypoxia, chemoreceptors of newborn (1-2 days) and older (10-12
days, 30 days, adult) rabbits were isolated and superfused, in vitro. The free
tissue catecholamine concentration was measured using carbon-fiber voltammetry
and pauci-fiber nerve activity was recorded from the sinus nerve during
stimulation (4 min) with graded hypoxia or increased potassium. Both the peak
catecholamine and peak nerve responses to stimulation with 10% and 0% oxygen
increased with age, particularly between 10 and 30 days of age. In contrast, peak
nerve and peak catecholamine responses to increased potassium did not
significantly change with age. For a better understanding of how responsiveness
increases with age, the fast Na+ and the Ca2+ currents were measured from
isolated glomus cells of newborn and older rabbits, but the magnitude of the
currents when normalized to membrane area was not significantly different between
ages. We conclude that: (1) rabbit chemoreceptors mature in the newborn period
(10-30 days) and part of this maturation is an increase in catecholamine
secretion, (2) maturation of hypoxia transduction primarily occurs in steps prior
to depolarization since potassium-evoked responses were not affected, and (3) an
increase in the magnitude of glomus cell fast Na+ or Ca2+ currents is not a
likely mechanism for the maturational change, but changes in the oxygen
sensitivity of these currents cannot be excluded.
PMID- 10678744
TI - Inner-medullary organic osmolytes and inorganic electrolytes in K depletion.
AB - The renal concentrating defect typical for chronic K depletion has been ascribed
to malfunction of renomedullary cells caused by inadequate accumulation of
organic osmolytes. A reduction in intracellular ionic strength, which is believed
to influence decisively the accumulation of organic osmolytes, has been held
responsible for insufficient osmolyte accumulation. To test this hypothesis,
intra- and extracellular Na, Cl and K concentrations, the major determinants of
ionic strength, were measured in the papilla by electron microprobe analysis and
organic osmolytes (glycerophosphorylcholine, betaine, sorbitol, myo-inositol,
free amino acids) in inner-medullary tissue by HPLC in antidiuretic rats kept on
either a control (normal-K) or a K-deplete (low-K) diet and in euhydrated rats
with free access to water and control diet. K depletion was associated with a
reduced urine concentrating ability. Papillary interstitial ionic strength (sum
of Na, Cl and K) in antidiuretic low-K rats was significantly reduced compared
with antidiuretic normal-K rats (688+/-19 vs. 971+/-61 mmol/kg wet wt) but was
similar to that in euhydrated normal-K rats (643+/-35 mmol/kg wet wt). The lower
interstitial ionic strength in antidiuretic low-K and euhydrated normal-K rats
was associated with a lower total content of organic osmolytes in the inner
medulla (365+/-14 and 381+/-20, respectively, vs. 465+/-11 mmol/kg protein in
antidiuretic normal-K rats). Intracellular ionic strength (sum of Na, Cl and K)
of papillary collecting duct cells, however, was similar in antidiuretic normal-K
and euhydrated normal-K rats (171+/-5 and 179+/-11 mmol/kg wet wt) but lower in
antidiuretic low-K rats (138+/-9 mmol/kg wet wt). These results do not support
the view that, in the steady state of osmotic adaptation of renomedullary cells
in situ, intracellular ionic strength is the decisive factor for maintaining high
levels of organic osmolytes. During chronic K depletion, reduced osmolyte
accumulation by renomedullary cells may be the consequence, rather than the
cause, of lower medullary interstitial tonicity.
PMID- 10678745
TI - Trans/paracellular, surface/crypt, and epithelial/subepithelial resistances of
mammalian colonic epithelia.
AB - The epithelial barrier function of the large intestine resides in the trans- and
paracellular pathways of the surface epithelium and crypts. Conventional
transmural resistance and permeability measurements, however, yield only the
resistance of the whole tissue and not that of its individual components.
Combining conductance scanning techniques and impedance analysis, we determined
the resistance of epithelial and subepithelial tissues, crypts and surface
epithelium, and trans- and paracellular pathways of the mouse distal colon. The
subepithelial tissue contributed 15% to the transmural resistance of 118+/-9
omega x cm2. In the epithelium proper the resistance of crypts (429+/-86 omega x
cm2) exceeded that of the surface epithelium (132+/-15 omega x cm2). The
paracellular resistance (3.2+/-0.4 k omega x cm2) of the surface epithelium was
23-fold higher than the transcellular resistance (137+/-16 omega x cm2), and thus
the epithelium was classified as "medium tight". In order to investigate the
trans- and paracellular resistances of the crypt epithelium as well, flat
monolayers of HT-29/B6 cultured colon crypt cells were studied, which had a
transepithelial resistance of 349+/-32 omega x cm2. With transcellular resistance
(377+/-41 omega x cm2) tenfold lower than the paracellular resistance (3.9+/-1.3
k omega x cm2), this cryptal monolayer was also classified as "medium tight".
Hence, considering the 1.2 times larger area of the crypt epithelium, the surface
epithelium has a 4 times larger ion permeability than the crypt epithelium.
However, the paracellular resistances are not different. Thus the lower
transcellular resistance of the surface compared to the crypt epithelium suggests
a higher density of ion channels in the apical membrane of surface cells.
PMID- 10678746
TI - Operation Everest III: energy and water balance.
AB - We hypothesized that hypoxia decreases energy intake and increases total energy
requirement and, additionally, that decreased barometric pressure increases total
water requirement. Energy and water balance was studied over 31 days in a
hypobaric chamber at 452-253 Torr (corresponding to 4,500-8,848 m altitude),
after 7 days acclimatization at 4,350 m. Subjects were eight men, age 27+/-4
years (mean+/-SD), body mass index 22.9+/-1.5 kg/m2. Food and water intake was
measured with weighed dietary records, energy expenditure and water loss with
labelled water. Insensible water loss was calculated as total water loss minus
urinary and faecal water loss. Energy intake at normoxia was 13.6+/-1.8 MJ/d.
Energy intake decreased from 10.4+/-2.1 to 8.3+/-1.9 MJ/d (P<0.001) and energy
expenditure from 13.3+/-1.6 to 12.1+/-1.8 MJ/d (P<0.001) over the first and
second 15-day intervals of progressive hypoxia. Absolute insensible water loss
did not change (1.67+/-0.26 and 1.66+/-0.37 l/d), however, adjusted for energy
expenditure it increased with ambient pressure reduction (P<0.05). In conclusion,
hypoxia induced a negative energy balance, mainly by a reduction of energy
intake. Overall insensible water loss was unchanged because the increase in
respiratory evaporative water loss was counterbalanced by a decrease in metabolic
rate that probably limited the hypoxia-induced increase in ventilation.
PMID- 10678747
TI - Chronic oxidative stress in the RVLM modulates sympathetic control of circulation
in pigs.
AB - Oxidative stress is a key event in the pathogenesis of several cardiovascular
diseases and may be similarly induced by long-term treatment with organic
nitrates. We examined the effects of inhibiting extracellular oxidative stress in
the rostral ventrolateral medulla (RVLM), the brain stem area which primarily
controls sympathetic tone. Superoxide dismutase (SOD, 10 U/microl) was
microinjected into the RVLM of anesthetized pigs that were either untreated
(control, n=10), treated for 4 weeks with the organic nitrate isosorbidedinitrate
(ISDN, 4 mg kg(-1) day(-1), n=6) or ISDN-treated followed by a 2-week recovery
period (recovery, n=4). In control animals SOD produced moderate inhibitory
effects on baseline sympathetic activity, indicated by decreases in renal
sympathetic nerve activity (RSNA), mean arterial blood pressure (MAP), and heart
rate (HR) without causing changes in femoral vascular conductance (FC). These
effects of SOD were greatly enhanced in ISDN-treated pigs. Following the recovery
period, SOD again produced smaller effects in the RVLM but they were, however,
still significantly greater than in untreated animals. In contrast, the
transmission of sympathoexcitatory reflexes by the RVLM, as evoked by sciatic
nerve stimulation, was not affected by SOD injections in either experimental
group. Furthermore, the number of NO-synthase-positive neurons in the RVLM region
was significantly reduced both in ISDN-treated and the recovery pigs, suggesting
that oxidative stress caused sustained changes in NOS activity within the brain
stem. These data suggest that excitatory actions of oxidative stress contribute
significantly to the generation of baseline sympathetic tone in the RVLM during
long-term treatment with organic nitrates. Similar mechanisms could promote
sympathetic tone in cardiovascular diseases that are associated with endogenous
oxidative stress for longer periods.
PMID- 10678748
TI - Lysophosphatidylcholine triggers intracellular calcium release and activation of
non-selective cation channels in renal arterial smooth muscle cells.
AB - The effects of a lipid component of oxidized low-density lipoproteins (ox-LDL), L
alpha-palmitoyl-lysophosphatidylcholine (LPC), on membrane currents of isolated
canine renal artery smooth muscle cells (RASMC) were examined using the whole
cell configuration of the patch-clamp technique. In RASMC exposed to nominally
Ca2+-free solutions and dialyzed with 0.1 mM EGTA and 140 mM K+, superfusion with
LPC (10 microM) elicited spontaneous transient outward currents (STOCs) and/or
spontaneous transient inward currents (STICs), followed by the activation of a
large voltage-independent current with a reversal potential (Er) close to 0 mV.
Buffering intracellular Ca2+ with 10 mM BAPTA prevented the appearance of STOCs
and STICs, but not the activation of the voltage-independent current. Er of the
LPC-induced voltage-independent current exhibited sensitivity to changes in [K+]o
and [Na+]o in a manner consistent with a non-selective cation current (I(NSC))
and was blocked by gadolinium (Gd3+; 10 microM). Shifts in Er of the LPC-induced
I(NSC) in response to changes in [Ca2+]o were used to estimate a relative Ca2+ to
Na+ permeability ratio (P(Ca)/P(Na)) of 1.67. These results suggest that LPC
causes abnormal sarcoplasmic reticulum Ca2+ regulation, leading to the appearance
of STOCs and STICs, and the activation of I(NSC) in vascular smooth muscle cells.
These effects may explain the ability of ox-LDLs to elevate [Ca2+]i in vascular
smooth muscle and inhibit endothelium-dependent relaxation.
PMID- 10678749
TI - Quinpirole attenuates the striatal immediate early gene expression, but not the
hyperactivity, induced by the serotonin agonist RU-24969.
AB - Systemic administration of the mixed 5-HT(1A/1B) agonist RU-24969 has been shown
to produce a dramatic increase in locomotor activity and to induce robust c-Fos
expression in the rat striatum. Previous studies have also shown that
pretreatment with the D2-like dopamine agonist quinpirole virtually abolishes RU
24969-induced striatal c-Fos expression. The present study was undertaken to
determine whether the effects of RU-24969 on immediate early gene expression
extend to the additional Fos family transcription factors FosB and Fra-2.
Additionally, this study quantitatively examined the effect of quinpirole
pretreatment on the ability of RU-24969 to induce both locomotor hyperactivity
and striatal immediate early gene expression. RU-24969 alone produced elevations
in locomotor activity and induced clear expression of c-Fos, FosB and Fra-2
throughout the entire striatal complex. Quinpirole pretreatment virtually
abolished RU-24969-induced expression of all three transcription factors, but did
not alter the elevated locomotor activity produced by RU-24969. These results
demonstrate that the effects of RU-24969 on locomotor activity can be dissociated
from its effects on immediate early gene expression within the striatum.
PMID- 10678750
TI - Mapping of the progressive metabolic changes occurring during the development of
hippocampal sclerosis in a model of mesial temporal lobe epilepsy.
AB - We have recently characterized the histopathological changes in an experimental
model of mesial temporal lobe epilepsy (MTLE) induced by the intrahippocampal
injection of low dose of kainate in mice. Although cerebral metabolism and blood
flow are extensively studied and used in human MTLE to locate the regions
involved in seizures before surgery, this exploration is only performed once the
disease has fully developed. Therefore, in the present study, we followed the
temporal evolution of intrahippocampal kainate-induced metabolic changes in mice
from kainate injection to 120 days later by the quantitative autoradiographic
[14C]2-deoxyglucose (2DG) technique. At day 0 (late phase of status epilepticus
(SE)) and 15 days after kainate, i.e., during the period of ongoing
neuropathological changes, glucose utilization was decreased bilaterally in all
parts of the cerebral cortex, and ipsilaterally in the thalamus. In the
hippocampus, CA1 metabolic activity was depressed at day 0 and increased at day
15 while CA3 glucose utilization was increased at both day 0 and 15. By day 30,
there were almost no pyramidal cells left in the two hippocampal regions. At day
120, ipsilateral decreases persisted in the entorhinal cortex, anterior and
ventromedian thalamus, and metabolic increases were recorded bilaterally in the
central amygdala, anterior hypothalamus and mamillary body. At all times after
kainate, a normo-, hypo- or hypermetabolic level was recorded in the dentate
gyrus. The present study shows that the process of hippocampal sclerosis involves
bilateral cortical reactivity and the participation of some limbic forebrain and
motor structures. When hippocampal sclerosis has fully developed, hypometabolism
is limited to regions directly connected to the damaged hippocampus and most
likely involved in the new hyperexcitable circuit of limbic seizures.
PMID- 10678751
TI - Gender differences in brain volume and size of corpus callosum and amygdala of
rhesus monkey measured from MRI images.
AB - While it has been established that the weight of the female rhesus monkey brain
is less than that of the male, the sexual dimorphism of specific brain structures
has not been well-documented. To further understand potential sex differences, we
measured the whole brain volume and the size of the corpus callosum (mid
sagittal) and amygdala (largest coronal section) in MRI images from juvenile to
adult male and female rhesus monkeys between 8 months and 7.2 years of age. The
mean volume of the male brain was 89.2 +/- 1.9 (S.E.M.) compared to the female
brain volume of 70.8 +/- 0.72 cm3. The average area of the corpus callosum
increased from 8 months to 4.5 years; 0.56 to 0.93 cm2 in males and 0.45 to 0.66
cm2 in females. However, the average area of splenium is significantly greater in
females (0.280 cm2), than males (0.184 cm2). The average area of the amygdala did
not change with age; it was 1.07 +/- 0.037 (S.E.M.) in males and 1.08 +/- 0.022
cm2 in females. This data suggests that the whole brain volume and the size of
the entire corpus callosum of young adult female rhesus monkeys are approximately
20% smaller than those of young adult males. Interestingly, the area of the
splenial portion of the corpus callosum is larger in female monkeys. The size of
the amygdala showed no sex difference.
PMID- 10678752
TI - Evidence that synaptically-released zinc contributes to neuronal injury after
traumatic brain injury.
AB - Prior evidence indicates that synaptically-released zinc enters postsynaptic
neurons in toxic excess during ischemia and seizures. In addition, prevention of
this zinc translocation has been shown to be neuroprotective in both ischemia and
seizures. Here we show evidence that the same translocation of zinc from
presynaptic boutons into postsynaptic neurons occurs after mechanical injury to
the brain. Specifically, using a rat model of traumatic brain injury, we show
that trauma is associated with (i) loss of zinc from presynaptic boutons (ii)
appearance of zinc in injured neurons, and (iii) neuroprotection by
intraventricular administration of a zinc chelator just prior to brain impact.
The possible use of zinc chelators for neuroprotection after head trauma is
considered.
PMID- 10678753
TI - Histochemically-reactive zinc in amyloid plaques, angiopathy, and degenerating
neurons of Alzheimer's diseased brains.
AB - Excess brain zinc has been implicated in Alzheimer's neuropathology. Here we
evaluated that hypothesis by searching the brains of Alzheimer's patients for
abnormal zinc deposits. Using histochemical methods, we found vivid Zn2+ staining
in the amyloid deposits of dense-core (senile) plaques, in the amyloid angiopathy
surrounding diseased blood vessels, and in the somata and dendrites of neurons
showing the characteristic neurofibrillary tangles (NFT) of Alzheimer's. In
contrast, brains from age-matched, non-demented subjects showed only occasional
staining for Zn2+ in scattered neurons and possible plaques. A role of abnormal
zinc metabolism in Alzheimer's neuropathology is suggested.
PMID- 10678754
TI - p75-mediated neuroprotection by NGF against glutamate cytotoxicity in cortical
cultures.
AB - Accumulating evidence suggests that the neurotrophin receptors, Trks and p75,
play distinct roles in regulating cells survival and death, with Trks important
for cell survival, and p75 acting to induce cell death. Here, we provide evidence
that, in neuronal cultures from rat cerebral cortex, nerve growth factor (NGF)
exerts neuroprotective actions via p75. Incubating cultures with NGF for 1-24 h
protected cortical neurons from delayed cytotoxicity induced by brief exposure to
glutamate. Delayed neurotoxicity induced by a calcium ionophore, ionomycin, or
nitric oxide (NO) donors such as S-nitrosocysteine (SNOC) and 3
morpholinosydnonimine (SIN-1), was also attenuated by pretreatment with NGF. RT
PCR analysis revealed the presence of p75 and trkB transcripts in cortical
cultures, but did not detect transcripts of trkA, a high-affinity receptor for
NGF. Brain-derived neurotrophic factor (BDNF), but not NGF, induced tyrosine
phosphorylation of Trks, indicating that NGF does not activate Trks in cortical
neurons. Concurrent application of anti-p75 neutralizing antibody markedly
reduced the neuroprotective effect of NGF, but resulted in only a modest
reduction of that of BDNF. BDNF-induced neuroprotection, but not NGF-induced
neuroprotection, was inhibited by a protein synthesis inhibitor cycloheximide.
Distinct signaling pathways mobilized by NGF and BDNF were also revealed in that
NGF but not BDNF stimulated significant production of ceramides, whereas BDNF but
not NGF caused persistent activation of mitogen-activated protein kinases. These
results indicate that, although NGF and BDNF both protect cortical neurons from
excitotoxicity, the mechanisms involved in their effects are totally different.
The present results are, to our knowledge, the first to demonstrate the principal
involvement of p75 in cytoprotective actions of neurotrophins.
PMID- 10678755
TI - Functional MRI of apomorphine activation of the basal ganglia in awake rhesus
monkeys.
AB - Functional magnetic resonance imaging (fMRI) was used to analyze blood oxygen
level-dependent (BOLD) responses in the nigrostriatal system (caudate nucleus,
putamen and substantia nigra) of awake rhesus monkeys to systemic apomorphine
administration. The study (1) measured BOLD responses as an index of neuronal
activity in the three structures following injections of the mixed D1/D2 agonist,
and (2) assessed the effects of isoflurane anesthesia on the fMRI responses.
Compared to control saline injections, 0.1 mg/kg apomorphine significantly
activated the caudate nucleus (P < or = 0.005), putamen (P < or = 0.001) and
substantia nigra (P < or = 0.005). The responses were consistent with activation
of GABAergic neurons in these three structures seen in other animal models.
Isoflurane gas measurably blunted the response to apomorphine, so that a
significant apomorphine activation was only seen in the substantia nigra of
anesthetized animals. Even there, the mean MR signal change was reduced from 9.8%
in awake monkeys to 2.3% in anesthetized animals. The data support the hypothesis
that fMRI can be used to study the effects of drugs that alter basal ganglia
activity in awake rhesus monkeys.
PMID- 10678756
TI - Acrylamide-regulated neurofilament expression in rat pheochromocytoma cells.
AB - Using the rat pheochromocytoma cell line (PC12), we present molecular evidence
that the neurotoxicant acrylamide directly induces neurofilament gene expression,
and the signaling pathways are initially distinctive from, but eventually merged
into, that for nerve growth factor (NGF)-induced neurofilament expression. In
PC12 cells, acrylamide increased neurofilament protein levels and synthesis.
Acrylamide had no effect on the stability of neurofilament mRNAs suggesting that
it directly increased neurofilament mRNA synthesis. K252a, a selective inhibitor
for NGF receptor gp140trk, had no effect on acrylamide induction, but completely
inhibited NGF-induced neurofilament protein synthesis. Therefore, the initial
step for acrylamide signaling was distinctive from NGF. Dexamethasone reversed
the effects of both NGF and acrylamide on neurofilament protein levels and
synthesis indicated that there is a dexamethasone-sensitive signaling step upon
which NGF and acrylamide merge, suggesting involvement of transcription
activating proteins like AP-1. These results, taken together with previous
studies of transgenic mice that overexpress neurofilament genes, may partially
explain the mechanisms of neurofilament accumulation in distal parts of large
axons, a pathognomonic feature of acrylamide neurotoxicity in animals.
PMID- 10678757
TI - Neuregulin found in cultured-sciatic nerve conditioned medium causes neuronal
differentiation of PC12 cells.
AB - The present work deals with the search and identification of the molecule or
combination of molecules, present in a medium conditioned by cultured rat-sciatic
nerves (CM), able to cause neuronal differentiation of PC12 cells. The molecular
mass range of the active fraction, as well as the thermostability and heparin
affinity of the active component found in previous work, all characteristics
shared with neuregulin (NRG) family members, led us to search for a NRG protein
in the CM. Nerves were previously cultured for 8 days and the CM collected every
24 h, the following 3 days. The CM was concentrated (30,000 NMWL) and
fractionated by quaternary ammonium chromatography and Cibacron blue affinity
chromatography. The most active fraction B1.2 was further characterized by
heparin affinity chromatography, size exclusion HPLC, Western blotting and
immunoprecipitation. Results reveal abundance of NRG mRNA in the cultured nerves,
presence of a 54 kDa NRG protein in the CM that increases along fractionation,
and progressive diminution of fraction B1.2 differentiation activity on PC12
cells by gradual removal of the NRG protein by immunoprecipitation. The abundance
of Schwann cells and the lack of axons in the cultured nerves suggest Schwann
cells as the main NRG source, to which fibroblasts and perineurial cells might
contribute.
PMID- 10678758
TI - Nitrotyrosine generation via inducible nitric oxide synthase in vascular wall in
focal ischemia-reperfusion.
AB - Nitrotyrosine produced by NO-mediated reaction is a possible marker for
cytotoxicity in brain ischemia. In this study, we aimed to determine whether iNOS
is responsible for the nitrotyrosine formation and which type of cell is
predominantly nitrated. Fifty-eight wild-type and 28 iNOS knockout male mice were
used. Under halothane anesthesia the left middle cerebral artery was occluded for
2 h and reperfused for 0.5 or 15 h. The ratio of nitrotyrosine to total tyrosine
(%NO2-Tyr) was measured by means of a hydrolysis/HPLC. After 0.5-h reperfusion,
%NO2-Tyr in the ischemic cortex of wild-type and knockout mice amounted to 0.037
+/- 0.040% (n = 8) and 0.064 +/- 0.035% (n = 6), respectively, being
significantly higher than that in the sham operation group (n = 7) (P < 0.05).
After 15-h reperfusion, nitrotyrosine was detected only in wild-type mice (0.039
+/- 0.025%, n = 7), not in knockout or sham-operated mice (P < 0.05).
Immunohistochemical reaction for nitrotyrosine was seen predominantly in the
vascular wall in the peri-infarct region of the cerebral cortex in wild-type mice
after 15-h reperfusion, but not in corresponding knockout mice. Our data suggest
that iNOS is responsible for nitrotyrosine formation in the later phase of
reperfusion, and that vascular endothelium is the major site of this reaction, at
least in the case of 15-h reperfusion.
PMID- 10678759
TI - Oxidative stress and Ca2+ influx upregulate calpain and induce apoptosis in PC12
cells.
AB - Calpain, a Ca2+-dependent cysteine protease, has previously been implicated in
apoptosis or programmed cell death (PCD) in immune cells. Although oxidative
stress and intracellular free Ca2+ are involved in neurodegenerative diseases,
the mechanism of neuronal cell death in the central nervous system (CNS) due to
these agents has not yet been defined. To explore a possible role for calpain in
neuronal PCD under oxidative stress and Ca2+ influx, we examined the effects of
H2O2 and A23187 on PC12 cells. Treatments caused PCD (light microscopy and TUNEL
assay) with altered mRNA expression (RT-PCR) of bax (pro-apoptotic) and bcl-2
(anti-apoptotic) genes, resulting in a high bax/bcl-2 ratio. Control cells
expressed 1.3-fold more microcalpain (requiring microM Ca2+) than mcalpain
(requiring mM Ca2+). Expression of mcalpain was significantly increased following
exposure to oxidative stress and Ca2+ influx. The mRNA levels of calpastatin
(endogenous calpain inhibitor) and beta-actin (house-keeping) genes were not
changed. Western analysis indicated degradation of 68 kDa neurofilament protein
(NFP), a calpain substrate. Pretreatment of cells with MDL28170 (a cell permeable
and selective inhibitor of calpain) prevented increase in bax/bcl-2 ratio,
upregulation of calpain, degradation of 68 kDa NFP, and occurrence of PCD. These
results suggest a role for calpain in PCD of PC12 cells due to oxidative stress
and Ca2+ influx.
PMID- 10678760
TI - Subcommissural organ-Reissner's fiber complex of the teleost Clarias batrachus
responds to GABA treatment.
AB - Subcommissural organ (SCO) is a highly specialized ependymal gland located in the
roof of the third ventricle. The secretory products of the SCO, which condense to
form Reissner's fiber (RF), were recently found to cross-react with the anti
calcitonin antibody. To understand the mechanisms regulating the formation of the
RF and the possible function of these discrete structures, we studied the
response of the SCO-RF complex to intracranially administered GABA, using
immunocytochemical labeling with anti-calcitonin antibody. Although the SCO-RF
complex of control fish was intensely immunostained, 1 h after GABA treatment,
the ependymal cells revealed partial loss of immunoreactivity; the RF showed
occasional loss of immunoreactivity with its diameter increased by about 56% of
the control value. Following 2 h of GABA treatment, the SCO revealed dramatic
loss of calcitonin-like immunoreactivity from the ependymal cells. The RF showed
a dual response in this group, while in some segments the RF appeared
conspicuously thick, elsewhere it appeared thin. The mean diameter was, however,
not significantly different from the normal. Following 4 h of GABA treatment,
while calcitonin-like immunoreactive material made its reappearance in the SCO,
the RF diameter was uniformly reduced to about 35% of the control value. The
responses by the RF as well as the SCO to intracranially administered GABA were
blocked by pretreatment with bicuculline, a GABA(A) receptor antagonist. The
results suggest that GABA, acting via GABA(A) receptors, may trigger the release
of secretory material from the SCO and induce histomorphological changes in the
RF indicative of discharge of stored material.
PMID- 10678761
TI - Propofol increases agonist efficacy at the GABA(A) receptor.
AB - Using the whole-cell patch-clamp technique, we have determined that propofol, but
not midazolam, increases the efficacy of piperidine-4-sulphonic acid (P4S), a
partial agonist at alpha1beta1gamma2s, GABA(A) receptors expressed in HEK 293
cells. These findings are consistent with the idea that propofol facilitates
receptor gating, while midazolam increases receptor occupancy by the agonist.
PMID- 10678762
TI - Macrophages: a major source of cytochrome b558 in the rat carotid body.
AB - The carotid body monitors arterial oxygen tension. Spectrophotometric recording
of the intact organ has revealed a cytochrome aa3 and a cytochrome b558 as
potential oxygen sensor candidates. The latter is known as part of the NADPH
oxidase system generating superoxide anions in the "respiratory burst" defense
mechanism, and glomus cells have been found to exhibit immunoreactivity against
this phagocyte cytochrome b558. Using a monoclonal antibody against the large
cytochrome b558 subunit, gp91phox, and other antibodies serving as neural (PGP
9.5) and monocyte/macrophage markers (ED1, ED2), we here demonstrate at light and
electron microscopical level that monocytes/macrophages are abundantly present in
the rat carotid body and represent the major source of cytochrome b558 in this
organ. Their presence has profound implications on the interpretation of
spectrophotometric recordings aimed to elucidate the mechanisms of oxygen sensing
since their high cytochrome b558 content will obscure possible contributions of
cell types involved in the oxygen sensor process.
PMID- 10678763
TI - Neurotrophin receptors in the somatosensory cortex of the mature rat: co
localization of p75, trk, isoforms and c-neu.
AB - Trk immunoreactivity is expressed by a discrete population of cortical neurons,
primarily those with cell bodies in layer Vb and dendrites in supragranular
cortex. We tested the hypothesis that neurons co-express multiple isoforms of trk
receptors. The distribution of neurons expressing specific high affinity
neurotrophin receptors was determined immunohistochemically. Multiple antibodies
directed against each trk isoform and an antibody directed against an epitope
shared by all three trk isoforms were used. The distribution of neurons
expressing each of the three receptors was virtually identical. Each anti-trk
antibody primarily labeled neurons with cell bodies in layer V. More than one
third of layer V neurons was positive for a high affinity trk receptor. Few
immunoreactive somata (1%-5%) were in the other layers. In addition, the neuropil
in the supragranular laminae was immunopositive for each trk isoform. Recent data
show that layer V neurons in the mature somatosensory cortex express the tyrosine
kinase receptor c-erbB2, also known as c-neu. Immunofluorescence double labeling
shows that approximately 80% of the c-neu-immunolabeled neurons in layer V co
expressed pan-trk immunoreactivity and two-thirds of all c-neu-positive neurons
expressed a specific trk isoform. We concluded from these data that there is
significant co-expression of trk isoforms in layer V neurons. In summary, trkA,
trkB, trkC, and c-neu were primarily expressed by cortical projection neurons in
layer V and co-expression among these receptors was common. This implies that
cortical growth factor systems are redundant and that cortical neurons are
responsive to more than one growth factor.
PMID- 10678764
TI - In vivo evidence that activation of tyrosine kinase is a trigger for
lipopolysaccharide-induced fever in rats.
AB - We measured the rectal temperature of free-moving, conscious rats after
intracerebroventricular (i.c.v.) injections of lipopolysaccharide (LPS) and
interleukin-1beta (IL-1beta) with or without various antagonists to investigate
the mechanisms involved in LPS-induced fever. LPS (3 microg) elicited significant
increases in rectal temperature, which lasted from 0.5 h to more than 8 h after
administration. This febrile response was inhibited by pretreatment with L-nitro
arginine (LNA), indomethacin (IND), genistein (GEN), tyrphostin 46 and anti-rat
IL-1beta antibody (anti-IL-1beta Ab), but was not inhibited by pretreatment with
daidzein or chelerythrine (CHE) into the ventricle. LPS (0.3 microg) following
orthovanadate (i.c.v.) produced fever, although the small amount of LPS (0.3
microg) or orthovanadate alone showed no effect on rectal temperature. I.c.v.
injections of IL-1beta also induced fever of approximately 4-h duration. This
effect was inhibited by pretreatment with IND and anti-IL-1beta Ab, but was not
inhibited by pretreatment with LNA, GEN or CHE into the ventricle. These findings
demonstrate that in the central nervous system, LPS increases IL-1beta production
after activation of tyrosine kinase and NO synthase, and IL-1beta promotes
prostaglandin production resulting in increased rectal temperature. Activation of
tyrosine kinase in the central nervous system is probably a trigger for the
febrile response induced by LPS.
PMID- 10678765
TI - GSH transport in human cerebrovascular endothelial cells and human astrocytes:
evidence for luminal localization of Na+-dependent GSH transport in HCEC.
AB - The purpose of the present study was to identify and localize glutathione (GSH)
transport in an in vitro tissue culture model of blood-brain barrier (BBB). The
localization of Na+-dependent GSH transport in an immortalized cell line of human
cerebrovascular endothelial cells (HCEC) and asymmetry of transport in Transwell
studies were investigated. Initial studies with cultured HCEC established a
significant (45%) Na+-dependency for GSH uptake in cultured HCEC pretreated with
acivicin, an inhibitor of gamma-glutamyltranspeptidase (GGT). Transendothelial
electrical resistance (TEER) and uptake of [35S]GSH from luminal and abluminal
fluids of HCEC were measured in Na+-containing and Na+-free (choline chloride)
buffers using cells grown on gelatin-coated membrane filters. TEER of HCEC
monolayers in regular medium was 40.1 +/- 8.0 ohms cm2. Human astrocyte
conditioned medium (ACM) caused no change in TEER, but increased GGT activity
approximately threefold when measured in cell lysates. Luminal and abluminal GSH
uptake increased in a time-dependent fashion and were not affected by inhibition
of GGT activity with acivicin. Sodium dependency was only observed for luminal
uptake (Na+-containing 2.41 +/- 0.15 vs. Na+-free 0.96 +/- 0.03 pmol/30
min/million cells, p < 0.001) but not for abluminal uptake (1.02 +/- 0.13 vs.
1.11 +/- 09, p > 0.05). Apparent efflux via the luminal membrane was lower in the
presence of sodium as compared to that without sodium, further suggesting that a
Na+-dependent uptake process for GSH is operative at this membrane. GSH uptake
and efflux were also demonstrated in neonatal rat and fetal human astrocytes,
both exhibiting partial Na+-dependency of uptake. In conclusion, our results show
for the first time, that HCEC and astrocytes take up GSH by both Na+-dependent
and -independent mechanisms. The Na+-dependent GSH transport process in HCEC
appears to be localized to luminal plasma membranes of HCEC.
PMID- 10678766
TI - The neural code for taste in the nucleus of the solitary tract of the rat:
effects of adaptation.
AB - Adaptation of the tongue to NaCl, HCl, quinine or sucrose was used as a tool to
study the stability and organization of response profiles in the nucleus of the
solitary tract (NTS). Taste responses in the NTS were recorded in anesthetized
rats before and after adaptation of the tongue to NaCl, HCl, sucrose or quinine.
Results showed that the magnitude of response to test stimuli following
adaptation was a function of the context, i.e., adaptation condition, in which
the stimuli were presented. Over half of all taste responses were either
attenuated or enhanced following the adaptation procedure: NaCl adaptation
produced the most widespread, non-stimulus-selective cross-adaptation and sucrose
adaptation produced the least frequent cross-adaptation and the most frequent
enhancement of taste responses. Adaptation to quinine cross-adapted to sucrose
and adaptation to HCl cross-adapted to quinine in over half of the units tested.
The adaptation procedure sometimes unmasked taste responses where none were
present beforehand and sometimes altered taste responses to test stimuli even
though the adapting stimulus did not itself produce a response. These effects
demonstrated a form of context-dependency of taste responsiveness in the NTS and
further suggest a broad potentiality in the sensitivity of NTS units across taste
stimuli. Across unit patterns of response remained distinct from each other under
all adaptation conditions. Discriminability of these patterns may provide a
neurophysiological basis for residual psychophysical abilities following
adaptation.
PMID- 10678767
TI - Activation of CB1 cannabinoid receptors inhibits neurotransmitter release from
identified synaptic sites in rat hippocampal cultures.
AB - The effects of cannabinoids on synaptic transmission were measured optically in
rat hippocampal cultures. Synaptic release sites were labeled with the
fluorescent dye FM1-43 in a stimulus-dependent manner. Action potential-induced
release of FM1-43 required extracellular Ca2+ and was inhibited 65 +/- 3% by
blockade of high-threshold voltage-gated Ca2+ channels with omega-grammotoxin SIA
(300 nM). The cannabimimetic drug, Win 55212-2 (300 nM), inhibited FM1-43 release
by 51 +/- 3%. The inhibition produced by Win55212-2 was blocked by the CB1
cannabinoid receptor antagonist, SR141716 (1 microM). The intensity of FM1-43
labeled puncta ranged 4-fold, although the inhibition produced by Win55212-2 was
distributed normally across synaptic sites of various labeling intensities. The
FM1-43-based optical method appears promising for the study of the effects of
cannabinoids and other drugs on synaptic networks. These results indicate that
cannabimimetics act presynaptically to inhibit the release of neurotransmitter
and that this inhibition is observed uniformly at boutons of varied activity
levels.
PMID- 10678768
TI - Evidence for physiological asymmetries in the intertectal connections of the
pigeon (Columba livia) and their potential role in brain lateralisation.
AB - In pigeons, visual object processing is lateralised with a dominance of the left
tectofugal system. To test the hypothesis, that avian visual lateralisation may
arise, at least in part, from asymmetric interhemispheric inhibition, the
intertectal modulation was quantified in 19 pigeons. Field potentials were
recorded from intratectal electrodes in response to a stroboscope flash to the
contralateral eye. Electrical stimulation of the contralateral tectum changed
these flash-evoked potentials. This change was taken as a measure of intertectal
modulation. It was found that the left-to-right tectotectal modulation was more
pronounced than vice versa, supporting the hypothesis of an asymmetric modulation
between the tecta of both hemispheres. It is conceivable that this lateralised
interhemispheric crosstalk could constitute an important component of asymmetric
visual processing.
PMID- 10678769
TI - Functional properties of the primary motor cortex and ventral premotor cortex in
the monkey during a visually guided jaw-movement task with a delay period.
AB - This study investigated single neuronal activity in the face area of the primary
motor cortex (MI) and ventral part of the premotor cortex (PMv) while a monkey
performed a visually guided jaw-movement task with a delay period. When the
monkey executed the jaw movements, 48 MI and 53 PMv neurons showed statistically
significant activities time-locked to jaw movements and were defined as movement
related neurons. The activities of movement-related neurons could be classified
into phasic, phasic-tonic and tonic patterns based on the changes in discharge
rate. Most of the neurons exhibiting phasic and phasic-tonic activities probably
contributed to the initiation of jaw movements, since they exhibited transient
responses immediately after the onset of the go-cue indicating the jaw movement.
In contrast, the sustained activity of the movement-related neurons exhibiting
phasic-tonic and tonic activities may be involved in controlling and/or
maintaining jaw position. Sustained activity was also detected during the delay
period in 4 MI and 29 PMv neurons and these neurons were defined as set-related
neurons. It is thought that these set-related neurons are involved in the
preparation for the subsequent jaw movement, since the masticatory muscles showed
no significant changes during the delay period. These findings suggest that the
MI may be involved predominantly in the initiation and control of jaw movements,
and that the PMv may be involved in motor preparation, and may play a role as a
higher-order motor area related to the initiation and control of jaw movements.
PMID- 10678770
TI - Expression of c-fos-like immunoreactivity in the feline brainstem in response to
isometric muscle contraction and baroreceptor reflex changes in arterial
pressure.
AB - This study compared whether activation of muscle ergoreceptor afferents caused by
isometric muscle contraction, activation of baroreceptor afferents induced by
i.v. infusion of phenylephrine, or baroreceptor afferent inactivation, caused by
carotid artery occlusion, elicit similar patterns of c-Fos induction in brainstem
areas. Adult cats were anesthetized with alpha-chloralose, and in each case, the
experimental intervention caused an increase in the arterial blood pressure.
There were two sets of control experiments: in both, animals underwent the same
surgical procedures but then either remained at rest for the entire study, or the
tibial nerve was stimulated, as in the contraction group, following muscle
paralysis with tubocurarine. Following the procedures, animals rested for 90 min
to allow neuronal expression of c-Fos. Control cats showed very little c-Fos
immunoreactivity (c-Fos-ir) in the brainstem. Muscle contraction induced c-Fos-ir
expression mainly in the nucleus tractus solitarius, lateral reticular nucleus,
lateral tegmental field, vestibular nucleus, subretrofacial nucleus, spinal
trigeminal tract and in a lateral region of the periaqueductal grey (P 0.5-1.0).
The majority of the c-Fos-ir was found in brainstem areas contralateral to the
contracted muscle. In addition, muscle contraction induced c-Fos-ir in the dorsal
horns of spinal segments L6-S1 on the ipsilateral side of the spinal cord.
Phenylephrine infusion caused c-Fos-ir expression in the nucleus tractus
solitarius, spinal trigeminal tract, solitary tract, and dorsal motor nucleus of
the vagus. No c-Fos-ir was apparent in the periaqueductal grey. Carotid
occlusions induced c-Fos-ir expression in the area postrema, nucleus tractus
solitarius, solitary tract, and spinal trigeminal tract. Expression was
bilateral. Areas that exhibited c-Fos-ir correspond to sites previously reported
to release various neuropeptides in response to muscle contraction or carotid
occlusions. These results indicate that the exercise pressor reflex and
baroreflex activate similar, but not completely identical, sites in the
brainstem.
PMID- 10678771
TI - (+/-)-Alpha-methyl-4-carboxyphenylglycine, a metabotropic glutamate receptor
blocker, impairs retention of an inhibitory avoidance task in rats when infused
into the basolateral nucleus of the amygdala.
AB - The amygdala is important for memory processes of emotionally motivated learning
and the amygdala glutamatergic system may play a key role in this process. In
this study we assessed the effect of the infusion of (+/-)-alpha-methyl-4
carboxyphenylglycine (MCPG), a metabotropic glutamate receptor (mGluR)
antagonist, into the basolateral complex of the amygdala (BLA) on the learning
and retention of an emotionally motivated task. Rats received either vehicle or
three different doses of MCPG (0.2, or 1.0, or 5.0 microg/0.2 microl/side,
respectively) bilaterally into the BLA, 5 min before they were trained in a
continuous multiple-trial inhibitory avoidance (CMIA) task. Response latencies
during the training were recorded. Retention was assessed 8 days later. MCPG in
the doses given did not significantly affect the acquisition of the CMIA task.
However, MCPG at a dose of 5.0 microg/0.2 microl/side impaired the long-term
retention test performance. Additionally, a nociception test indicated that dose
of MCPG infused into the BLA did not affect the footshock sensitivity. Our
results indicate that MCPG, when infused into the BLA of rats prior to the
training, impaired long-term memory of aversive training without affecting
acquisition.
PMID- 10678773
TI - Expression and development of the proenkephalin mRNA in the C cells of chicken
ultimobranchial glands.
AB - A large number of enkephalin-immunoreactive cells transiently appear in chick
ultimobranchial glands during embryonic development. The expression and
development of proenkephalin mRNA were examined in the ultimobranchial glands by
in situ hybridization with digoxigenin (DIG)-labeled oligonucleotide probes, in
comparison with those of calcitonin mRNA and enkephalin peptide. Proenkephalin
mRNA, as well as calcitonin mRNA, appeared in some C cells at embryonal day 14 (E
14), and in many cells at E 16. Subsequently, there is a marked increase in the
level of calcitonin mRNA around E 18-19; all C cells exhibited intense reaction
for calcitonin mRNA. After hatching, intensity of calcitonin mRNA expression was
more and more increased. Northern blot analysis with the calcitonin probe also
indicated that calcitonin synthesis of the C cells progressively increased with
developmental gradient, and reached to the adult level at 1 month after hatching.
On the other hand, intensity of hybridization signal of proenkephalin mRNA was
maintained moderately during development. In contrast to enkephalin
immunoreactivity, which is markedly decreased after hatching, proenkephalin mRNA
expression was consistently detected in many C cells of 1- and 2-month-old
chickens. Reverse transcription-polymerase chain reaction (RT-PCR) analysis
confirmed that proenkephalin mRNA was obtained in the ultimobranchial glands of
not only embryos but also 1-day- and 1-month-old chickens. Furthermore, Northern
blot analysis demonstrated that a single band for proenkephalin mRNA was obtained
in the poly (A)+RNA isolated from the ultimobranchial gland of 1-day-old chicks.
Thus, the present study evidences that proenkephalin mRNA is synthesized in
almost all C cells of chicken ultimobranchial glands throughout life. Enkephalin
may be essential for C cell function.
PMID- 10678772
TI - Co-distribution patterns of chromogranin B-like immunoreactivity with
chromogranin A and secretoneurin within the human brainstem.
AB - As members of the chromogranin family, chromogranin A, chromogranin B, and
secretogranin II are acidic proteins found in large, dense core vesicles. They
are endoproteolytically processed to smaller peptides and released after neuronal
stimulation. Using immunocytochemistry, this study closely examines chromogranin
B-like immunoreactivity within the human brainstem and then takes a comparative
view of co-distribution patterns by chromogranin B, chromogranin A, and
secretogranin II. We used an antiserum raised against a synthetic peptide (PE-11)
present in the chromogranin B molecule. Secretogranin II was localized with an
antiserum against secretoneurin, a 33 amino acid peptide, found within the
secretogranin II precursor. Like chromogranin A and secretoneurin, chromogranin B
is expressed through all levels of the human brainstem. Chromogranin B was
exclusively detected in neuronal structures. The medial part of the substantia
nigra pars reticulata, the nucleus interpeduncularis, the area of the central
gray, and the raphe complex displayed a high density of PE-11-like
immunoreactivity. Furthermore, a prominent staining was found in the medial,
dorsal and gelatinous subnuclei of the solitary tract and the dorsal motor
nucleus of vagus. The substantia gelatinosa of the caudal trigeminal nucleus and
spinal cord were also very strongly PE-11-immunopositive. In conclusion,
chromogranin B and secretogranin II showed similar distributions while neuronal
localization typically differed from chromogranin A aside from a few exceptions.
These findings may provide a framework for future research in revealing a
functional role of chromogranin peptides in the human brainstem.
PMID- 10678774
TI - A comparative non-radioactive in situ hybridization and immunohistochemical study
of the distribution of alpha7 and alpha8 subunits of the nicotinic acetylcholine
receptors in visual areas of the chick brain.
AB - The distribution of mRNA transcripts corresponding to the alpha7 and alpha8
subunits of the nicotinic acetylcholine receptors (nAChRs) was studied in
selected structures of the chick visual system with non-radioactive in situ
hybridization and immunohistochemical techniques. The results indicated that the
alpha7 and alpha8 nAChR transcripts are widely distributed in the brain,
exhibiting differential expression in some structures but also some degree of co
localization. The pattern of localization of alpha7 and alpha8 nAChR transcripts
was highly correlated with immunohistochemical data, with very few instances of
possible mismatches between the distribution of mRNAs and their corresponding
proteins.
PMID- 10678775
TI - Upregulation of brain somatostatin and neuropeptide Y following lidocaine-induced
kindling in the rat.
AB - Male Sprague-Dawley rats received a daily injection of 60 mg/kg of lidocaine (>
30 days). Twenty percent of rats developed convulsions (kindled rats) and
remaining rats did not show convulsions (non-kindled rats). The level of
immunoreactive somatostatin (IR-SRIF) in kindled rats was significantly increased
in amygdala than that in non-kindled rats and control rats. Immunoreactive
neuropeptide Y (IR-NPY) contents in kindled rats were significantly increased in
amygdala, hippocampus, cortex and striatum compared to non-kindled and control
rats. The expression of SRIF mRNA in kindled rats produced a significant increase
in amygdala, while NPY mRNA in kindled rats showed an elevated expression in both
amygdala and hippocampus. These results coincide with the previous findings with
the elevated expression of SRIF and NPY mRNA in electrically and
pharmacologically kindled models, suggesting the important role of these peptides
in the kindling phenomenon.
PMID- 10678776
TI - The distribution of neuropeptide Y and brain-derived neurotrophic factor
immunoreactivity in hippocampal formation of the monkey and rat.
AB - The distribution of neuropeptide Y (NPY) and Brain-Derived Neurotrophic Factor
(BDNF) in the hippocampal formation of monkey and rat brains was studied
immunohistochemically. The NPY-neuronal system is more highly developed in the
monkey compared to that in the rat. The distribution of NPY-positive products was
coincident with that of abundant BDNF-positive deposits. These observations
suggest that the role of BDNF and the interaction of BDNF-NPY may differ between
species.
PMID- 10678777
TI - Sleep-inducing effects of adenosine microinjections into the medial preoptic area
are blocked by flumazenil.
AB - Microinjection of a wide range of sedative agents, including triazolam,
pentobarbital, ethanol and adenosine, into the medial preoptic area has been
shown to increase sleep, suggesting that it is an important (though not
necessarily the only) anatomic site mediating hypnotic effects of these
compounds. The mechanism by which adenosine increases sleep at this site is not
clear, but one possibility is that this is related to its effects on the GABA(A)
benzodiazepine receptor complex. In order to assess this possibility, this paper
describes the administration of adenosine, alone and in combination with the
benzodiazepine receptor blocker flumazenil, into the MPA. It was found that 12.5
and 25 nM of adenosine significantly reduced sleep latency and increased total
sleep time. The sleep-inducing effect was blocked by flumazenil. Flumazenil
caused a modest increase in total sleep, and prevented the increase in total
sleep induced by the higher dose of adenosine. These data suggest that at least
one aspect of the hypnotic properties of adenosine is mediated by a direct or
indirect action on the GABA(A)-benzodiazepine receptor complex.
PMID- 10678778
TI - Human interferon-alpha induces immobility in the mouse forced swimming test:
involvement of the opioid system.
AB - In a previous study, we indicated that human interferon (IFN)-alpha (IFN-alpha, 6
x 10(4) IU/kg, i.v.), but not human IFN-beta or -gamma, prolonged the immobility
time of the forced swimming test in mice. In this study, we investigated the
mechanism of the effect of human IFN-alpha. None of the mouse IFNs tested (IFN
alpha/beta, IFN-beta, and IFN-gamma, 3 x 10(5) U/kg, i.v.) changed the immobility
time or the spontaneous locomotor activity in mice. Indomethacin (10 mg/kg,
s.c.), a cyclooxygenase inhibitor, did not affect the increase in the immobility
time induced by human IFN-alpha (6 x 10(4) IU/kg, i.v.). However, naloxone (1
mg/kg, s.c.), an opioid receptor antagonist, blocked the increasing caused by
human IFN-alpha in the forced swimming test. These results suggest that the
increase in the immobility time caused by human IFN-alpha in the forced swimming
test might be mediated through opioid receptors, but not mouse IFN receptors.
PMID- 10678779
TI - Interactions of galanin and morphine in the spinal antinociception in rats with
mononeuropathy.
AB - The increased hind-paw withdrawal latency (HWL) to thermal stimulation and hind
paw withdrawal threshold (HWT) to mechanical stimulation induced by morphine were
attenuated by intrathecal injection of 1 or 3 nmol, but not 0.3 nmol of the
selective galanin antagonist galantide. The result indicated a possible
interaction between galanin and opioids in the transmission of presumed
nociceptive information in the spinal cord of rats with mononeuropathy.
PMID- 10678780
TI - Potassium chloride depolarization enhances MPP+-induced hydroxyl radical
generation in the rat striatum.
AB - We determined that extracellular potassium ion concentration, [K+]o-induced
depolarization, enhances 1-methyl-4-phenylpyridinium ion (MPP+)-induced hydroxyl
radical (*OH) generation in the rat striatum. Rats were anesthetized, and sodium
salicylate in Ringer's solution (0.5 nmol/microl/min) was infused through a
microdialysis probe to detect the generation of *OH as reflected by the non
enzymatic formation of 2,3-dihydroxybenzoic acid (DHBA) in the striatum.
Induction of high concentration KCl (70 mM) drastically increased formation of
*OH trapped as DHBA by the action of MPP+. When dopamine (DA) was administered to
the high KCl-treated animals, a marked elevation of DHBA was observed, compared
with MPP+-only-treated animals, that showed a positive linear correlation between
DA and *OH formation trapped as DHBA (R2 = 0.979) in the dialysate. When
corresponding experiments were performed with iron (II), the same results were
obtained: a positive linear correlation between the release of iron (II) and DHBA
(R2 = 0.988) in the dialysate. These results suggest that [K+]o-induced
depolarization enhances the formation of *OH products of efflux/oxidation due to
MPP+.
PMID- 10678781
TI - A role of glutamate in drug-induced ototoxicity: in vivo microdialysis study
combined with on-line enzyme fluorometric detection of glutamate in the guinea
pig cochlea.
AB - The time course of the changes in perilymphatic glutamate was determined during
the application of kanamycin and ethacrynic acid, which are known to damage the
hair cells in the inner ear. For the continuous recording of glutamate, the
microdialysis technique combined with an enzyme-linked fluorometric assay was
used. In guinea pigs receiving a loading dose of 800 mg/kg of kanamycin
subcutaneously followed 3 h later by an i.v. injection of 40 mg/kg of ethacrynic
acid, a marked glutamate release was clearly found about 2 h after the injection
of ethacrynic acid. Injection of kanamycin or ethacrynic acid alone did not
produce any change in the perilymphatic glutamate. The morphological changes
induced by the administration of both drugs indicated that the collapsing hair
cells might release glutamate into the perilymphatic space. The present findings
provide additional evidence that glutamate acts as an aggravating factor in
aminoglycoside-induced ototoxicity.
PMID- 10678782
TI - Loss of bag-1 immunoreactivity in rat brain after transient middle cerebral
artery occlusion.
AB - Although bag-1 is a strong apoptosis repressor protein, its functions in normal
or injured brains are not fully understood. In the present study, we investigated
expression of bag-1 protein in rat brain after transient middle cerebral artery
(MCA) occlusion, and compared the results with that of terminal deoxynucleotidyl
transferase-mediated dUTP-biotin end labeling (TUNEL). Immunohistochemical
analysis revealed that neuronal, choroid plexus, and ependymal cells were
positively stained in the sham control brain. After 90 min of transient MCA
occlusion, immunoreactivity for bag-1 progressively decreased from 3 to 48 h in
the nuclei of neurons. Western blot analysis revealed that immunoreactive bag-1
was markedly decreased in the nuclear fraction. In contrast, cytosolic and
mitochondrial fractions showed no or only slight change after the ischemia. TUNEL
positive cells appeared at 48 h after the reperfusion, which was preceded by loss
of bag-1 immunoreactivity. The present results suggest that bag-1 plays some
roles in normal neuronal function, and its loss may be involved in neuronal cell
death after ischemia.
PMID- 10678783
TI - New advances in preventing and treating serious surgical infection: introduction.
PMID- 10678784
TI - Antimicrobial action and pharmacokinetics/pharmacodynamics: the use of AUIC to
improve efficacy and avoid resistance.
AB - In in-vitro and in animal models, antibiotics show good relationships between
concentration and response, when response is quantified as the rate of bacterial
eradication. The strength of these in-vitro relationships promises their utility
for dosage regimen design and predictable cure of human infections. Resistance is
also predictable from these parameters, fostering a rational means of using
dosing adjustments to avoid or minimize the development of resistant organisms.
Newly developed computerized methods for the quantitation of susceptibility allow
testing of integrated kinetic-susceptibility models in patients. Our attention
has focused recently on fluoroquinolones, since they are relatively non-toxic and
provide the necessary range of dosage needed to elucidate correlations between
concentration and response in the Intensive Care Unit patient. Studies conducted
in patients with nosocomial gram-negative pneumonia reveal good correlations
between bacterial eradication and integration of concentration with bacterial
susceptibility. In patients, the best correlation parameters are time over MIC,
and the ratio of 24-hour AUC to MIC (AUIC). Patients with serious infections like
nosocomial pneumonia require bactericidal antimicrobial activity. Studies in our
laboratory demonstrate that the minimum effective antimicrobial action is an area
under the inhibitory titer (AUIC) of 125, where AUIC is calculated as the 24-hour
serum AUC divided by the MIC of the pathogen. This target AUIC may be achieved
with either a single antibiotic or it can be the sum of AUIC values of two or
more antibiotics. There is considerable variability in the actual AUIC value for
patients when antibiotics are given in their usually recommended dosages.
Examples of this variance will be provided using aminoglycosides,
fluoroquinolones, beta-lactams, macrolides and vancomycin. The achievement of
minimally effective antibiotic action, consisting of an AUIC of at least 125, is
associated with bacterial eradication in about 7 days for beta-lactams and
quinolones. When AUIC is increased to 250, the quinolone ciprofloxacin (which
displays in vivo concentration dependent bacterial killing) can eliminate the
bacterial pathogen in 1-2 days. Beta lactams, even when dosed to an AUIC of 250,
often require longer treatment duration to eliminate the bacterial pathogen,
because the in vivo bacterial killing rate is slower with beta-lactams than with
the quinolones. This remains true even at AUIC values of 250 for both compounds,
which is theoretically identical dosing. Antibiotic activity indices allow
clinicians to evaluate individualized patient regimens. Furthermore, antibiotic
activity is a predictable clinical endpoint with predictable clinical outcome.
This value is also highly predictive of the development of bacterial resistance.
Antimicrobial regimens that do not achieve an AUIC of at least 125 cannot prevent
the selective pressure that leads to overgrowth of resistant bacterial sub
populations. Indeed, there is considerable anxiety that conventional respiratory
tract infection management strategies, which prescribe antibacterial dosages that
may attain AUIC values below 125, are contributing to the pandemic rise in
bacterial resistance levels.
PMID- 10678785
TI - Antimicrobial chemotherapy in the control of surgical infectious complications.
AB - In spite of the progress in surgical technique and antibiotic prophylaxis,
postoperative infection still accounts for both the commonest surgical
complication and one of the most frequent nosocomial infections, also causing an
increase in duration and costs of hospital stay. The choice of treatment for post
surgical infections requires an understanding of the usual infecting flora,
available antimicrobial agents, and susceptibility patterns. The most common
organisms in simple wound infection are gram-positive cocci and mainly
Staphylococcus aureus. Staphylococcus epidermidis and S. aureus (quite often
methicillin-resistant strains) are the organisms which predominate in the
infectious complications following clean surgical procedures with implantation of
vascular grafts or prosthetic devices. Mixed aerobic and anaerobic flora are
mainly responsible for cases of intra-abdominal and intra-pelvic postoperative
infections: the most common aerobes are Enterobacteriaceae (Escherichia coli,
Proteus spp., and others) and enterococci, and among anaerobes Bacteroides
fragilis group prevails. Adequate drainage and surgical control of the source of
infection, when needed, and adjunctive effective antimicrobial therapy are
important factors in successful treatment of postoperative infections.
Semisynthetic penicillinase-resistant penicillins and glycopeptides (vancomycin
and teicoplanin) are the drugs of choice for the treatment of infections caused
by penicillin-resistant methicillin-sensitive, and methicillin-resistant,
respectively, S. aureus and S. epidermidis. For the treatment of intra-abdominal
and intra-pelvic infections, animal and human studies support the recommendation
that treatment should be directed against both gram-negative enteric and
anaerobic bacteria. Combinations of aminoglycosides with clindamycin or
metronidazole have been widely used with great success; however adverse reactions
such as nephrotoxicity and ototoxicity have been a problem in some patients. In
recent years monotherapy with either a carbapenem (imipenem/cilastatin or
meropenem) or a penicillin/beta-lactamase inhibitor combination has been
proposed. Among these combination antimicrobials, piperacillin combined with
tazobactam is a very well designed formulation. Indeed, piperacillin is active
against a broad range of gram-negative and gram-positive pathogens, and
tazobactam is a potent beta-lactamase inhibitor which acts on a variety of
clinically important plasmid and chromosomal beta-lactamases. This combination
seems particularly attractive for the treatment of mixed polymicrobial anaerobic
aerobic infections such as intra-abdominal and intra-pelvic postoperative
infections.
PMID- 10678786
TI - Chemotherapy for gram-positive nosocomial sepsis.
AB - Over recent years gram-positive bacterial pathogens have become dominant in many
forms of nosocomial infections. The principal pathogens in severe infections are
Staphylococcus aureus and enterococci. The utility of the traditional antibiotics
used for nosocomial sepsis, particularly beta-lactam agents, has been severely
compromised by the spread of resistance and there was, often, no therapeutic
alternative to the glycopeptide antibiotics, vancomycin and teicoplanin, for
empirical (and often also the specific) therapy of infections caused by
methicillin-resistant S. aureus (MRSA) and Enterococcus spp. This reliance on
glycopeptides, however, is now also threatened by acquired resistance. Vancomycin
resistant enterococci (VRE), particularly E. faecium, have become a therapeutic
problem in many European cities and are now endemic in some hospital wards. The
recent reports from several continents of MRSA with reduced glycopeptide
susceptibility (GISA) is of grave concern. New agents are needed to meet these
threats and several classes of compounds are under development. One class is the
streptogramins and the combination of quinupristin/dalfopristin (Synercid) is
nearing licensing. Clinical trials and a compassionate use programme have already
shown it to have considerable promise for the treatment of the most problematic
forms of gram-positive nosocomial sepsis, including MRSA and vancomycin-resistant
E. faecium infections that had failed therapy with other antibiotics.
PMID- 10678787
TI - New advances in the use of antimicrobial agents in surgery: intra-abdominal
infections.
AB - Advances in both technical methods and antimicrobial therapy have significantly
reduced morbidity and mortality for secondary (enterogenous) or community
acquired intra-abdominal infections. Presumptive antimicrobial therapy for most
community-acquired intra-abdominal infection can be safely initiated with a
single broad-spectrum antimicrobial effective against the expected
Enterobacteriaceae and anaerobic flora. Beta-lactams and carbapenems are
effective against gram-negative rods and anaerobes, achieve therapeutic levels
rapidly, and have low toxicity in the absence of penicillin allergy. Second
generation cephalosporins (e.g. cefoxitin and cefotetan) remain useful in
surgical prophylaxis and treatment of mild community-acquired pneumonia, but
limitations in their spectra and antimicrobial resistance restrict their utility
in more serious infections. The fourth generation cephalosporins are also
effective, but should be combined with other antimicrobials such as metronidazole
for adequate anaerobic coverage. Preliminary data on new fluoroquinolones are
scant, but promising results were obtained in one clinical trial. We predict the
current trend toward the use of broad-spectrum single agent antimicrobials for
therapy of intra-abdominal infection will continue.
PMID- 10678788
TI - Management of complicated intra-abdominal infections.
AB - Complicated intra-abdominal infections are defined by the U.S. Food and Drug
Administration as those in which an operation would not remove all of the
infected tissue. Therefore perforated appendicitis, although usually
straightforward to treat, would be considered complicated, whereas gangrenous non
perforated appendicitis would not. Antibiotics play an adjunctive role to the
surgical procedure in the management of these infections. Studies of newer
antibiotics generally exclude critically ill patients, so it is unclear whether
dose or duration of therapy can be addressed by such studies. Typical
characteristics of anti-infective studies of intra-abdominal infection are:
enrollment of upwards of 50% appendicitis cases, mortality 5%, and a clinical
cure rate of 85%. Several antibiotic combinations with metronidazole are
acceptable (e.g. third- or fourth-generation cephalosporin, aminoglycoside,
aztreonam, or second-generation quinolone), as are several agents as monotherapy
(e.g. second-generation cephalosporin, beta-lactamase agent, or third-generation
quinolone). In addition to questions of dose and duration, questions have been
raised regarding the value of intraoperative cultures, and whether issues of the
quality of the surgical procedure can be addressed. The issue of the adequacy of
surgical "source control" may be paramount, as an improper, untimely, or
incorrect operation would have an overwhelmingly negative effect on outcome
compared to the efficacy of the antibiotic.
PMID- 10678789
TI - High-dose intravenous fluoroquinolones in the treatment of severe infections.
AB - A bacterial infection should be considered "serious" in case of underlying
disease, nosocomial origin, antibiotic resistant pathogen, and/or poor delivery
of antibiotics at the site of infection. Treatment of most serious infections
requires parenteral administration of antimicrobial agents. Intravenous
fluoroquinolones are a class of antimicrobial agents from which physicians must
choose when treating nosocomial infections. Fluoroquinolones are bactericidal
antimicrobial agents that act by inhibiting DNA gyrase. They are active in vitro
against most gram-negative bacteria and methicillin-susceptible staphylococci.
Activity against anaerobic bacteria and streptococci is poor. The rapid
development of bacterial resistance in centers with high quinolone usage is of
great concern. Resistance develops most commonly in Pseudomonas aeruginosa and
staphylococci. Most clinical trials with ciprofloxacin, ofloxacin, pefloxacin,
the fluroquinolones currently available in France for parenteral use, are almost
10 years old. There are few studies with higher dosage and most of them have been
carried out with ciprofloxacin. The findings of these studies indicate that
higher dosage regimens of i.v. ciprofloxacin are much more effective against
severe nososcomial infections than is the dosage of 200 mg twice daily. The
higher dosage regimens resulted in greater rates of clinical cure and improvement
in both monomicrobial and polymicrobial infections. Although the overall
frequency of side effects to fluoroquinolones is low, seizures and allergic
reactions have been attributed to their use.
PMID- 10678790
TI - Fourth generation cephalosporins in the antimicrobial chemotherapy of surgical
infections.
AB - Surgical infections include a variety of entities such as secondary peritonitis,
intra-abdominal abscesses, obstetric and gynecological infections as well as bone
joint and soft-tissue infections. By definition the term "surgical infection"
implies that surgery itself plays the major role in therapy, while antimicrobial
chemotherapy is only supplementary. Broad-spectrum empirical regimens employed
include the combination of a 1st or 2nd generation cephalosporin plus clindamycin
or metronidazole +/- aminoglycoside (depending on the severity of the condition).
Cefepime and cefpirome are new 4th generation parenteral cephalosporins with a
spectrum of activity which makes them suitable for the treatment of infections
caused by a wide variety of bacteria. They are active against both gram-positive
and gram-negative organisms, including Staphylococcus aureus and Pseudomonas
aeruginosa with activity comparable to or greater than that of cefotaxime or
ceftazidime respectively. Cefepime in particular is also very active against
strains of Enterobacter and Pseudomonas spp resistant to these two agents. In
comparison with 3rd generation cephalosporins, cefepime appears to be less likely
to induce resistance, due to a lower rate of hydrolysis by beta-lactamases, a low
affinity for these enzymes and more rapid permeation into the cell. Despite the
fact that a 4th generation cephalosporin is well-suited for the treatment of
polymicrobial infections, the following should be kept in mind: (I) MRSA strains
and Bacteroides fragilis group are not included in their spectrum of activity.
(II) Cefpirome is the only cephalosporin with in vitro activity against
Enterococci. (III) Severe surgical infections of nosocomial origin, and
particularly in settings where Enterobacter spp predominate, represent the major
indication for empirical use of a 4th generation cephalosporin in combination
with a nitroimidazole.
PMID- 10678791
TI - Treatment of fungal infections in surgical patients using conventional
antifungals.
AB - In surgical and intensive care units an alarming increase in the number of
invasive fungal infections has been observed. This is partly due to temporal
transferral of patients from hemato-oncological units or transplant units and
partly to the enhanced use of corticosteroids and other immunosuppressants.
Candida species have now become a common isolate in ill patients. Amphotericin B
with or without flucytosine constituted the standard therapy for candidosis but
similar response rates with less toxicity may be obtained with lipid and with
fluconazole. Data on an improved outcome of candidemia if a central venous
catheter is removed promptly are conflicting. Amphotericin B remains the standard
therapy for other invasive mycoses; it is seldom possible to administer adequate
doses and therefore the options and limitations of the triazoles and liposomal
preparations should be explored.
PMID- 10678792
TI - Role of newer azoles in surgical patients.
AB - Fungal infection has become an important cause of morbidity and mortality in
critically ill surgical patients. Surgical patients at highest risk for invasive
mycoses include those undergoing extensive abdominal surgery, those with
underlying malignancy or other immunosuppressive conditions, and patients
undergoing transplantation. Nosocomial candidemia remains a major complication
for patients in surgical intensive units; however, the epidemiology of invasive
fungal infection continues to change with molds and yeasts other than Candida
albicans emerging as important causes of infection especially in immunosuppressed
patients. This changing epidemiology has resulted in the need for an expanded
armamentarium of antifungal therapies. One effective approach has been the
utilization of higher doses of well-tolerated azoles, such as fluconazole,
particularly against yeasts with dose-dependent susceptibility. Alternatively,
the presumptive use of therapeutic doses of fluconazole may be indicated in
intensive care unit patients with persistent leukocytosis and fever in whom a
source of fever cannot be identified, particularly if the patient is extensively
colonized at mucosal sites with yeast. New azoles with an expanded spectrum of
activity are in development. These include agents include voriconazole, which has
activity against resistant yeasts and molds and is in phase III clinical trials,
posaconazole (Sch 56592) and ravuconazole (BMS-207147)--both of which are less
advanced in clinical development, but which also offer an expanded spectrum of
activity. Other new azoles with expanded activity are still in the early phases
of development. In this review, strategies for optimizing use of the clinically
available new azoles and the potential for new agents are discussed.
PMID- 10678793
TI - Impact of severe infections on the outcome of major liver surgery: a
pathophysiologic and clinical analysis.
AB - Although major progress has been achieved, particularly in the field of patient
selection and postoperative intensive care, morbidity and mortality rates after
major liver surgery are still significant. In fact, the mortality rate in major
series reaches 30% of patients undergoing complex liver procedures, mostly
related to postoperative septic events. Among these, although extra-abdominal
infectious localizations are also frequently reported, intra-abdominal sepsis and
abscess formation are probably the most frequent infective clinical
presentations. The literature reports that the magnitude of the resection and
duration of surgery are associated with a significantly higher postoperative
morbidity and mortality rate. Severe postoperative infectious events cause a high
proportion of this morbidity and in the presence of a septic evolution of the
clinical picture the mortality rises dramatically. Such a tight association
between severe infections and mortality after major hepatic surgery gives account
to the fundamental role played by the liver in the metabolic homeostasis of the
patient and also to the central hepatic function in the immune response to
microorganisms of gastroenteric origin. After major liver surgery these central
hepatic functions may by significantly impaired, thus leading to higher
susceptibility to infections, in particular in the elderly. On these bases the
improvement in prophylaxis protocols, in the early diagnosis and in the treatment
of these postoperative infectious events can help optimize clinical results after
major hepatic surgery.
PMID- 10678794
TI - Emerging antimicrobial resistance in the surgical compromised host.
AB - Improvements in the treatment of compromised patients have resulted in their
prolonged survival in a debilitated state. Patients have repeated courses of
antibiotics and become colonised with multiresistant pathogens during a stay in
the intensive care unit. Surgical wound infections can then be very difficult to
treat. Methicillin-resistant Staphylococcus aureus is now common although wide
variations in prevalence exist between countries and regions. Klebsiella spp with
multiple resistance is a common cause of septicemia and can be associated with
cephalosporin use. Acinetobacter spp and vancomycin-resistant enterococci can
cause infections resistant to all readily available antibiotics. The prevalence
of infection with each of these pathogens is increasing. Control measures should
include hand washing, universal precautions for infection control, source
isolation, restrictive antibiotic policy and antibiotic rotation. Although new
agents currently in trials may be effective in the long term, the future for
antibiotic treatment or prophylaxis of surgical infections is in doubt.
PMID- 10678795
TI - Management of the critically ill patient with severe sepsis.
AB - Sepsis is a common cause of morbidity and mortality among the critically ill
patient population. However, no anti-sepsis therapy has yet been found to be
effective and treatment is thus largely supportive. Adequate fluid resuscitation
must be accompanied by effective ventilation, and adrenergic agents may be needed
to restore perfusion pressure and improve myocardial function. Enteral
nutritional support with specialized nutrients has beneficial effects on
morbidity, and should be started early. Further research will allow better
definition of the septic patient according to immune status and enable more
effective targeting of future anti-sepsis treatments.
PMID- 10678796
TI - Antibiotic use and microbial resistance in intensive care units: impact of
computer-assisted decision support.
AB - As part of our integrated hospital information system (the HELP system), we
developed computer-assisted decision support programs for antimicrobial
prescribing that are available at bedside terminals throughout our 520-bed
community hospital. Recently, options have been added to allow direct physician
order entry of anti-infective agents in the shock-trauma intensive care unit
(STRICU). Physicians prescribed the computer-suggested regimens for 46% but
followed the suggested dose and interval for 93% of the orders during a 1-year
study period. In comparison to a 2-year pre-intervention period, improved drug
selection and reductions in adverse drug events and costs were seen.
Antimicrobial resistance patterns for nosocomial gram-negative isolates remained
stable or improved in the STRICU over an 11-year period of computer-assisted
antibiotic management. We conclude that strategies for optimizing antimicrobial
prescribing have the potential to stabilize resistance and reduce costs by
encouraging heterogeneous prescribing patterns, use of local antimicrobial
susceptibility patterns to inform empiric drug selection, and reduced "tonnage"
of antibiotic use.
PMID- 10678797
TI - Sepsis and septic shock: pro-inflammatory or anti-inflammatory state?
AB - A considerable body of evidence indicates that together with an important pro
inflammatory reaction, a anti-inflammatory response contributes to the onset of
sepsis and organ failure. At a local site of injury or infection and during the
initial appearance of pro- and anti-inflammatory mediators in the circulation,
the beneficial effects of these compounds counterbalance their harmful effects.
Only when the balance between these two forces is lost may these substances
become harmful. The sequelae of an unbalanced systemic inflammatory reaction
include derangement of microcirculation, shock, transudation into organs and
defects of coagulation. An unbalanced systemic compensatory anti-inflammatory
response often results in anergy and immunosuppression. The pro-inflammatory and
anti-inflammatory conditions may ultimately reinforce each other, creating a
state of destructive immunologic dissonance. In the present report, recent
literature on cytokines was reviewed together with the 89 clinical papers
published between 1993 and 1997 on the role of cytokines during sepsis and other
inflammatory reactions. Cytokines were analyzed in more than 5,000 patients.
Sepsis and septic shock were the two groups most represented (2834 individuals
and 550 respectively). Only 12% (11) of the studies showed a correlation with the
presence of sepsis or septic complications. Overall 27 (39%) studies found a
correlation between levels of cytokine and mortality. Fifty (62%) of the 80
studies that investigated this correlation found that the amount of cytokines did
not predict death. The rest of the 30 (48%) investigations depicted an
unhomogeneous picture: even though 27 studies evidenced higher levels of
cytokines in non-survivors, 3 studies found the opposite.
PMID- 10678798
TI - New rationale for glucocorticoid treatment in septic shock.
AB - Two recent small randomized trials evaluating a 5- to 12-day course of low dose
hydrocortisone in patients with septic shock have reported a significant clinical
improvement and a reduction in mortality. Recent studies indicate that an
overaggressive and unregulated systemic inflammatory response is a major
determinant of outcome in sepsis. In septic shock, nonsurvivors as opposed to
survivors have over time: (1) significantly higher NF-kB activity in peripheral
mononuclear cells, (2) persistent elevation in circulating inflammatory cytokine
levels, and (3) elevated ACTH and cortisol levels. Current research recognizes
that cytokines can cause a concentration-dependent resistance to endogenous
glucocorticoids (GC). It is postulated that an excess of cytokine-induced
transcription factors, such as NF-kB, may form complexes with activated
glucocorticoid receptors (GCR), preventing GCR interaction with DNA. When T cells
are incubated with a combination of cytokines, GC resistance is induced in a
cytokine concentration-dependent fashion and reversed by removal of cytokines.
Prolonged treatment with physiological doses of exogenous GCs may be necessary to
compensate adequately for the inability of target organs to respond to endogenous
cortisol and for the inability of the host to produce appropriately elevated
levels of GCs. This hypothesis is supported by the laboratory findings of a
recent randomized study of patients with unresolving acute respiratory disease.
PMID- 10678799
TI - Short-term prophylaxis in clean-contaminated surgery.
AB - Postoperative infections are not consistently controlled by current practice
measures. From a recent study of 12,384 patients, postoperative infection
occurred in 22% of colorectal procedures and 25% of upper gastrointestinal
procedures. Infections were associated with a higher death rate, longer
hospitalization, and more intense post-discharge care. Control of infections for
clean-contaminated procedures requires effective bowel cleansing when
appropriate, meticulous surgical technique, and timely antimicrobial
administration. Many patients undergoing clean-contaminated surgery do not
receive properly timed antimicrobials. Although the comparative value of oral
(neomycin and erythromycin) or parenteral antimicrobials for colon surgery
remains an unresolved issue, the combination can be beneficial for many
colorectal operations. Third generation cephalosporins are not consistently more
effective than older agents such as cefoxitin and increase bacterial resistance.
Improper antimicrobial timing is one of the most common problems with surgical
prophylaxis and is fully under the control of the surgeon. To maximize benefits
of antimicrobial prophylaxis, systems should be devised to assure timely
administration.
PMID- 10678800
TI - Is single-dose antibiotic prophylaxis sufficient for any surgical procedure?
AB - The objective of perioperative prophylaxis is to prevent postoperative
infections, which are the primary cause of morbidity and mortality in patients
undergoing surgery today. One cannot predict with certainty when bacterial
contamination at the operative site may occur during surgery. Furthermore, it has
been suggested that the period of highest risk may actually be at the end, rather
than at the beginning, of the operation. Therefore, the effect of antimicrobial
prophylaxis ideally should cover the entire perioperative "period of risk". It
should be remembered that the period of risk for postoperative infection may last
substantially longer than the actual surgical procedure. The duration of the risk
period also may vary based on a number of other factors, such as the age and
general condition of the patient, presence of concomitant disease, amount of
blood loss during surgery, and number of blood transfusions required.
Antimicrobial prophylaxis that provides coverage throughout the entire
perioperative period of risk will reduce not only the risk of wound infections
but may also reduce the danger of other types of infectious complications.
Numerous clinical studies have clearly shown that appropriately-timed "single
shot" prophylaxis is as effective as multiple-dose prophylaxis. This paper
considers the evolution of this therapeutic intervention and reviews the
opportunities available for antibiotic prophylaxis in surgery, with particular
attention to the long-acting cephalosporin, ceftriaxone.
PMID- 10678801
TI - Antimicrobial prophylaxis in surgery: the role of pharmacokinetics.
AB - Even though surgical infection rates have decreased dramatically during the past
25 years, morbidity and mortality of infection in surgical treatment remains
substantial. From a pharmacological point of view, the key factor of the efficacy
of antibiotic prophylaxis is to attain bactericidal levels of antibiotic in serum
and tissues (target site) during the whole intraoperative and early postoperative
period. The success of antibiotic prophylaxis is assured only when the chosen
antibiotic with a targeted spectrum and high antimicrobial efficacy is available
at the critical moment, at the correct site and in sufficiently high
concentration to prevent bacterial contamination of the surgical area. It would
be desirable for reasons of convenience and cost if a single preoperative
administration were sufficient. The pharmacokinetics and the half-life of
antibiotics in the serum are directly related to the duration of activity of
antibiotic in the tissue. Antibiotics with longer half-lives maintain levels in
the tissues for longer periods than do antibiotics with shorter half-lives and
they cover with a single dose the time required for prophylaxis even for longer
operations. Finally, the application of the pharmacokinetic properties of
antibiotics to surgical prophylaxis can provide the surgeon with certainty that
adequate coverage and protection with antibiotics are achieved before and
throughout the operation.
PMID- 10678802
TI - Monitoring of antimicrobial prophylaxis in general surgery.
AB - The incidence of infections in general surgery is related to different factors.
Cost-benefit analysis of antimicrobic prophylaxis is positive, even though
incorrect use may be even dangerous (development of resistance and/or
superinfections, for instance). The authors report data on a study concerning a
total of 316 patients divided into two series, who had antimicrobic prophylaxis
before a surgical operation. 274 patients out of 316 (or 86.7%) had an ultra
short (one-shot-only) or short (<24 hours) prophylaxis, 42 (13.3%) standard (>24
hours). The operations performed were classified following class of
contamination, i.e. I (clean), II (potentially contaminated), III (contaminated).
Antibiotics used were ceftizoxime, cefepime, ceftriaxone, piperacillin and
gentamicin in combination. A total of 16 postoperative infections was observed
(5%); 11 of these 16 belonged to class III operations. Escherichia coli and
Staphylococcus aureus were isolated in most of the infected wounds. The data
confirm what is reported in the literature. The authors conclude that a
preoperative single-shot 3rd or 4th generation cephalosporin reduces the
incidence of wound infections in clean and clean-contaminated surgery.
PMID- 10678803
TI - Antimicrobial prophylaxis in obstetric and gynecological surgery.
AB - A major problem in obstetric and gynecological surgery, especially following
cesarean section in labor, total vaginal or abdominal hysterectomy, or
myomectomy, is postoperative wound infection. Consequently, the use of
antimicrobial prophylaxis for cesarean section and for gynecological surgery has
been advocated and shown to be effective in reducing postoperative morbidity,
costs and duration of hospitalization. We reviewed 1021 patients who underwent
cesarean section (597 elective, 424 emergency) and 814 gynecological patients
undergoing abdominal (373) or vaginal (248) hysterectomy and myomectomy (193)
between 1997-98 in the Obstetrics and Gynecology Clinic of the University of
Florence. Before surgery 83.6% of obstetric and 75.1% of gynecological patients
received 1 or 2 g of a first or second generation cephalosporin i.v. as a single
dose regimen at induction of anesthesia and sometimes a second postoperative
dose. 1.5% of obstetric surgical patients had wound infection, as did 2.8% of
gynecological surgery patients, with a mean postoperative hospital stay of 8
days. The short-term perioperative antimicrobial prophylaxis with cephalosporins
is useful and provides the benefit of minimal toxicity and risk of
chemoresistance.
PMID- 10678804
TI - Management of Helicobacter pylori infection: gastroenterological and surgical
perspectives.
AB - Diagnosis and treatment of Helicobacter pylori is a crucial point in the
management of the different gastroduodenal disorders. Management involves the
general practitioner and different specialists such as internists,
gastroenterologists and surgeons. Among the most frequent H. pylori-related
gastroduodenal disorders of medical interest are some diseases such as dyspepsia
and gastroesophageal reflux, where the role of the bacterium is not well defined
and therefore the importance H. pylori eradication is still controversial. On the
contrary, the relationship of H. pylori and gastric and duodenal peptic ulcer is
widely and definitively proven, and there are no doubts regarding the importance
of curing the bacterium in these disorders. However, the surgical aspect of
peptic ulcer, in particular the relevance and management of its complications,
has not been widely investigated so far. In fact, the prevalence of H. pylori in
perforated, bleeding and stenotic peptic ulcers seem to be lower that in non
complicated peptic ulcer, and whenever H. pylori eradication virtually prevents
the re-bleeding of peptic ulcer in all cases, the effect of curing the bacterium
in perforated and stenotic ulcers is still largely unknown. The management of H.
pylori infection after gastric surgery is also still controversial. Most studies
suggest that H. pylori can persist after gastric surgery whenever its incidence
is much lower than that before operation. However it seems most unlikely that the
infection plays a major role in the development of ulcer recurrence after gastric
surgery or in the induction of gastric carcinoma. In any case, there are no
convincing data that its cure may prevent the occurrence of gastric carcinoma
following gastrectomy procedures.
PMID- 10678805
TI - Helicobacter pylori determinants of pathogenicity.
AB - The bacterium Helicobacter pylori colonises the stomach of man and induces a
strong inflammatory response. Differences in the possession of pathogenicity
determinants by H. pylori isolates could account in part for the different
clinical outcomes of infection. The main H. pylori pathogenic factors, i.e.
urease, the cytotoxin VacA, and the genes involved in virulence contained in the
pathogenicity island (PAI) cag, may promote tissue damage and ulceration, and
could contribute to gastric cancer development. Strains with the mosaic vacA
allelic type s1a/m1 and possessing the cag insertion are considered endowed with
increased inflammatory potential, and are more likely to be isolated from
patients with peptic ulcer and gastric cancer. The presence in H. pylori cag PAI
of operons involved in the stimulation of gastric epithelial cells to secrete
high levels of inflammatory cytokines, in mobilisation of DNA, and formation of
secretory mechanisms and conjugation apparati, could contribute to increase the
risk of gastric cancer development in patients infected by this microorganism.
PMID- 10678807
TI - Pet Travel Scheme: updated advice from MAFF.
PMID- 10678806
TI - Helicobacter pylori: optimum diagnosis and test of cure.
AB - The fact that about 50% of the world's population is infected with Helicobacter
(H.) pylori and the important role that this bacterium plays in public health
have been important incentives in the search for accurate diagnostic methods. A
large number of invasive and non-invasive methods have been used to diagnose H.
pylori infection. Each method has its advantages and disadvantages and each
practitioner should choose the best diagnostic method according to the facilities
available. Non-invasive tests for the diagnosis of H. pylori infection are
largely used in clinical practice and in management of patients with
gastroduodenal disease. Serology is the most widespread test but its use is not
advised in the post-treatment follow-up. The Urea Breath Test is a simple, safe
and highly accurate method ideal for evaluating the short-term follow-up of H.
pylori eradication after therapy.
PMID- 10678808
TI - Abomasal bloat, haemorrhage and ulcers in young Norwegian lambs.
AB - An abomasal syndrome affecting mainly three- to four-week-old lambs was studied
by using a case-control design involving 88 cases and 85 controls. The principal
clinical signs were tympany and colic. The cases were divided into three groups
according to the main gross pathological findings in 82 of them. The 28 lambs in
group 1 had abomasal tympany, the 29 lambs in group 2 had severe damage to the
abomasal mucosa, and the 25 lambs in group 3 consisted mainly of lambs with
various other diseases in combination with abomasal changes. The lambs in group 1
had a significantly (P<0.05) lower mean (se) abomasal pH (2.7 [0.19]) than those
in group 2 (4.1 [0.32]), group 3 (3.7 [0.39]) or the controls (3.3 [0.13]). The
ruminal pH values ranged from 3.5 to 7.4 but there were no significant
differences between the groups. Lambs with ulcers had a significantly (P<0.05)
higher frequency of trichophytobezoars, than the cases without ulcers or the
controls. The tympanic lambs in group 1 had a significantly higher mean packed
cell volume, and higher mean red and white blood cell counts, and a significantly
lower mean cell volume and mean cell haemoglobin concentration than the healthy
control lambs.
PMID- 10678809
TI - Identification of porcine circovirus in tissues of pigs with porcine dermatitis
and nephropathy syndrome.
AB - Thirty-three pigs affected by porcine dermatitis and nephropathy syndrome, 30
from Spain and three from the USA, were investigated in order to detect porcine
circovirus (PCV) in their tissues. A standard in situ hybridisation technique
using a specific DNA 317-bp probe based on a well-conserved sequence of PCV
(which recognises both PCV-1 and PCV-2) was applied to formalin-fixed, paraffin
embedded tissues. Twenty-eight of the 30 Spanish pigs and all three American pigs
had PCV in at least one tissue. Viral nucleic acid was detected mainly in
lymphoid organs, and especially the lymph nodes. The viral genome was also found,
in order of decreasing quantity, in Peyer's patches, tonsil, lung, spleen,
kidney, liver, and skin. Viral nucleic acid was located mainly within the
cytoplasm of monocyte/macrophage lineage cells, including follicular dendritic
cells, macrophages, histiocytes and Kupffer cells. No viral nucleic acid was
found in damaged glomeruli or arteriolar walls. In frozen samples available from
three Spanish pigs, the virus was identified as type 2 by using the polymerase
chain reaction and restriction fragment length polymorphism. Most of the pigs
from which serum was available were seropositive against porcine respiratory and
reproductive syndrome virus (PRRSV), and PRRSV antigen was detected in the lung
of two of the Spanish pigs. These results suggested that PCV is present in
tissues of almost all pigs affected by PDNS, and PCV has to be considered as a
possible agent involved in the pathogenesis of the syndrome.
PMID- 10678810
TI - Urethral duplication and chromosomal translocation in a Swiss braunvieh heifer.
AB - As it was urinating, a six-month-old Swiss braunvieh heifer produced a second
stream of urine from a fistula that opened on the ventrolateral margin of the
left vulval lip. A catheter was introduced into this opening and passed easily
into the bladder. Urethrography showed that the fistula joined the urethra in the
mid-pelvic region and that a single canal originated from the bladder. Endoscopy
confirmed this finding and also revealed a duplication of the vaginal portion of
the cervix, a division of the cranial vagina by a septum and a fibrous band in
the region of the hymenal ring. Cytogenetic examination revealed reciprocal
translocation between chromosomes 20q23 and 22q23. A diagnosis of urethra duplex,
duplication of the vaginal portion of the cervix and reciprocal autosomal
translocation between chromosomes 20 and 22 was made on the basis of these
findings.
PMID- 10678811
TI - Bordetella bronchiseptica infection in cats following contact with infected dogs.
PMID- 10678812
TI - Dichloromethane poisoning in a dog: a case report.
PMID- 10678813
TI - Birth of a BVDV-free calf from a persistently infected embryo transfer donor.
PMID- 10678814
TI - Rabies in African wild dogs (Lycaon pictus) in the Madikwe Game Reserve, South
Africa.
PMID- 10678815
TI - Development of canine oocytes matured and fertilised in vitro.
PMID- 10678816
TI - Chronic nasal discharge in dairy cows.
PMID- 10678817
TI - Vet Helpline.
PMID- 10678818
TI - Severe foot lesions in sheep.
PMID- 10678819
TI - Society for Veterinary Clinical Research.
PMID- 10678820
TI - Returning to practice.
PMID- 10678821
TI - Reindeer concerns.
PMID- 10678822
TI - Reindeer concerns.
PMID- 10678823
TI - Interpreting differential temperature trends at the surface and in the lower
troposphere
AB - Estimated global-scale temperature trends at Earth's surface (as recorded by
thermometers) and in the lower troposphere (as monitored by satellites) diverge
by up to 0.14 degrees C per decade over the period 1979 to 1998. Accounting for
differences in the spatial coverage of satellite and surface measurements reduces
this differential, but still leaves a statistically significant residual of
roughly 0.1 degrees C per decade. Natural internal climate variability alone, as
simulated in three state-of-the-art coupled atmosphere-ocean models, cannot
completely explain this residual trend difference. A model forced by a
combination of anthropogenic factors and volcanic aerosols yields surface
troposphere temperature trend differences closest to those observed.
PMID- 10678824
TI - Crystal structure of the ribonucleoprotein core of the signal recognition
particle.
AB - The signal recognition particle (SRP), a protein-RNA complex conserved in all
three kingdoms of life, recognizes and transports specific proteins to cellular
membranes for insertion or secretion. We describe here the 1.8 angstrom crystal
structure of the universal core of the SRP, revealing protein recognition of a
distorted RNA minor groove. Nucleotide analog interference mapping demonstrates
the biological importance of observed interactions, and genetic results show that
this core is functional in vivo. The structure explains why the conserved
residues in the protein and RNA are required for SRP assembly and defines a
signal sequence recognition surface composed of both protein and RNA.
PMID- 10678825
TI - Three-layered atmospheric structure in accretion disks around stellar-mass black
holes
AB - Modeling of the x-ray spectra of the Galactic superluminal jet sources GRS
1915+105 and GRO J1655-40 reveals a three-layered atmospheric structure in the
inner region of their accretion disks. Above the cold and optically thick disk
with a temperature of 0.2 to 0.5 kiloelectron volts, there is a warm layer with a
temperature of 1.0 to 1.5 kiloelectron volts and an optical depth around 10.
Sometimes there is also a much hotter, optically thin corona above the warm
layer, with a temperature of 100 kiloelectron volts or higher and an optical
depth around unity. The structural similarity between the accretion disks and the
solar atmosphere suggests that similar physical processes may be operating in
these different systems.
PMID- 10678826
TI - Multidecadal changes in the vertical temperature structure of the tropical
troposphere
AB - Trends in global lower tropospheric temperature derived from satellite
observations since 1979 show less warming than trends based on surface
meteorological observations. Independent radiosonde observations of surface and
tropospheric temperatures confirm that, since 1979, there has been greater
warming at the surface than aloft in the tropics. Associated lapse-rate changes
show a decrease in the static stability of the atmosphere, which exceeds unforced
static stability variations in climate simulations with state-of-the-art coupled
ocean-atmosphere models. The differential temperature trends and lapse-rate
changes seen during the satellite era are not sustained back to 1960.
PMID- 10678827
TI - Self-assembling amphiphilic siderophores from marine bacteria.
AB - Most aerobic bacteria secrete siderophores to facilitate iron acquisition. Two
families of siderophores were isolated from strains belonging to two different
genera of marine bacteria. The aquachelins, from Halomonas aquamarina strain
DS40M3, and the marinobactins, from Marinobacter sp. strains DS40M6 and DS40M8,
each contain a unique peptidic head group that coordinates iron(III) and an
appendage of one of a series of fatty acid moieties. These siderophores have low
critical micelle concentrations (CMCs). In the absence of iron, the marinobactins
are present as micelles at concentrations exceeding their CMC; upon addition of
iron(III), the micelles undergo a spontaneous phase change to form vesicles.
These observations suggest that unique iron acquisition mechanisms may have
evolved in marine bacteria.
PMID- 10678828
TI - Widespread complex flow in the interior of the antarctic ice sheet
AB - It has been suggested that as much as 90% of the discharge from the Antarctic Ice
Sheet is drained through a small number of fast-moving ice streams and outlet
glaciers fed by relatively stable and inactive catchment areas. Here, evidence
obtained from balance velocity estimates suggests that each major drainage basin
is fed by complex systems of tributaries that penetrate up to 1000 kilometers
from the grounding line into the interior of the ice sheet. This finding has
important consequences for the modeled or estimated dynamic response time of past
and present ice sheets to climate forcing.
PMID- 10678829
TI - Density of phonon states in iron at high pressure
AB - The lattice dynamics of the hexagonal close-packed (hcp) phase of iron was
studied with nuclear inelastic absorption of synchrotron radiation at pressures
from 20 to 42 gigapascals. A variety of thermodynamic parameters were derived
from the measured density of phonon states for hcp iron, such as Debye
temperatures, Gruneisen parameter, mean sound velocities, and the lattice
contribution to entropy and specific heat. The results are of geophysical
interest, because hcp iron is considered to be a major component of Earth's inner
core.
PMID- 10678830
TI - Inhibition of experimental liver cirrhosis in mice by telomerase gene delivery.
AB - Accelerated telomere loss has been proposed to be a factor leading to end-stage
organ failure in chronic diseases of high cellular turnover such as liver
cirrhosis. To test this hypothesis directly, telomerase-deficient mice, null for
the essential telomerase RNA (mTR) gene, were subjected to genetic, surgical, and
chemical ablation of the liver. Telomere dysfunction was associated with defects
in liver regeneration and accelerated the development of liver cirrhosis in
response to chronic liver injury. Adenoviral delivery of mTR into the livers of
mTR(-/-) mice with short dysfunctional telomeres restored telomerase activity and
telomere function, alleviated cirrhotic pathology, and improved liver function.
These studies indicate that telomere dysfunction contributes to chronic diseases
of continual cellular loss-replacement and encourage the evaluation of
"telomerase therapy" for such diseases.
PMID- 10678831
TI - Prevention of acute liver failure in rats with reversibly immortalized human
hepatocytes.
AB - Because of a critical shortage in suitable organs, many patients with terminal
liver disease die each year before liver transplantation can be performed.
Transplantation of isolated hepatocytes has been proposed for the temporary
metabolic support of patients awaiting liver transplantation or spontaneous
reversion of their liver disease. A major limitation of this form of therapy is
the present inability to isolate an adequate number of transplantable
hepatocytes. A highly differentiated cell line, NKNT-3, was generated by
retroviral transfer in normal primary adult human hepatocytes of an immortalizing
gene that can be subsequently and completely excised by Cre/Lox site-specific
recombination. When transplanted into the spleen of rats under transient
immunosuppression, reversibly immortalized NKNT-3 cells provided life-saving
metabolic support during acute liver failure induced by 90% hepatectomy.
PMID- 10678832
TI - The glucocorticoid receptor: rapid exchange with regulatory sites in living
cells.
AB - Steroid receptors bind to site-specific response elements in chromatin and
modulate gene expression in a hormone-dependent fashion. With the use of a tandem
array of mouse mammary tumor virus reporter elements and a form of glucocorticoid
receptor labeled with green fluorescent protein, targeting of the receptor to
response elements in live mouse cells was observed. Photobleaching experiments
provide direct evidence that the hormone-occupied receptor undergoes rapid
exchange between chromatin and the nucleoplasmic compartment. Thus, the
interaction of regulatory proteins with target sites in chromatin is a more
dynamic process than previously believed.
PMID- 10678833
TI - Dopaminergic loss and inclusion body formation in alpha-synuclein mice:
implications for neurodegenerative disorders.
AB - To elucidate the role of the synaptic protein alpha-synuclein in
neurodegenerative disorders, transgenic mice expressing wild-type human alpha
synuclein were generated. Neuronal expression of human alpha-synuclein resulted
in progressive accumulation of alpha-synuclein-and ubiquitin-immunoreactive
inclusions in neurons in the neocortex, hippocampus, and substantia nigra.
Ultrastructural analysis revealed both electron-dense intranuclear deposits and
cytoplasmic inclusions. These alterations were associated with loss of
dopaminergic terminals in the basal ganglia and with motor impairments. These
results suggest that accumulation of wild-type alpha-synuclein may play a causal
role in Parkinson's disease and related conditions.
PMID- 10678834
TI - Neuroimaging evidence for dissociable forms of repetition priming.
AB - Repetition priming has been characterized neurophysiologically as a decreased
response following stimulus repetition. The present study used event-related
functional magnetic resonance imaging to investigate whether this repetition
related response is sensitive to stimulus familiarity. A right fusiform region
exhibited an attenuated response to the repetition of familiar stimuli, both
faces and symbols, but exhibited an enhanced response to the repetition of
unfamiliar stimuli. Moreover, both repetition effects were modulated by lag
between successive presentations. Further experiments replicated the interactions
between repetition, familiarity, and lag and demonstrated the persistence of
these effects over multiple repetitions. Priming-related responses are therefore
not unitary but depend on the presence or absence of preexisting stimulus
representations.
PMID- 10678835
TI - Sparse coding and decorrelation in primary visual cortex during natural vision.
AB - Theoretical studies suggest that primary visual cortex (area V1) uses a sparse
code to efficiently represent natural scenes. This issue was investigated by
recording from V1 neurons in awake behaving macaques during both free viewing of
natural scenes and conditions simulating natural vision. Stimulation of the
nonclassical receptive field increases the selectivity and sparseness of
individual V1 neurons, increases the sparseness of the population response
distribution, and strongly decorrelates the responses of neuron pairs. These
effects are due to both excitatory and suppressive modulation of the classical
receptive field by the nonclassical receptive field and do not depend critically
on the spatiotemporal structure of the stimuli. During natural vision, the
classical and nonclassical receptive fields function together to form a sparse
representation of the visual world. This sparse code may be computationally
efficient for both early vision and higher visual processing.
PMID- 10678836
TI - Mitochondrial FtsZ in a chromophyte alga.
AB - A homolog of the bacterial cell division gene ftsZ was isolated from the alga
Mallomonas splendens. The nuclear-encoded protein (MsFtsZ-mt) was closely related
to FtsZs of the alpha-proteobacteria, possessed a mitochondrial targeting signal,
and localized in a pattern consistent with a role in mitochondrial division.
Although FtsZs are known to act in the division of chloroplasts, MsFtsZ-mt
appears to be a mitochondrial FtsZ and may represent a mitochondrial division
protein.
PMID- 10678837
TI - Convergent solutions to binding at a protein-protein interface.
AB - The hinge region on the Fc fragment of human immunoglobulin G interacts with at
least four different natural protein scaffolds that bind at a common site between
the C(H2) and C(H3) domains. This "consensus" site was also dominant for binding
of random peptides selected in vitro for high affinity (dissociation constant,
about 25 nanomolar) by bacteriophage display. Thus, this site appears to be
preferred owing to its intrinsic physiochemical properties, and not for
biological function alone. A 2.7 angstrom crystal structure of a selected 13
amino acid peptide in complex with Fc demonstrated that the peptide adopts a
compact structure radically different from that of the other Fc binding proteins.
Nevertheless, the specific Fc binding interactions of the peptide strongly mimic
those of the other proteins. Juxtaposition of the available Fc-complex crystal
structures showed that the convergent binding surface is highly accessible,
adaptive, and hydrophobic and contains relatively few sites for polar
interactions. These are all properties that may promote cross-reactive binding,
which is common to protein-protein interactions and especially hormone-receptor
complexes.
PMID- 10678838
TI - Evidence for a high frequency of simultaneous double-nucleotide substitutions.
AB - Point mutations are generally assumed to involve changes of single nucleotides.
Nevertheless, the nature and known mechanisms of mutation do not exclude the
possibility that several adjacent nucleotides may change simultaneously in a
single mutational event. Two independent approaches are used here to estimate the
frequency of simultaneous double-nucleotide substitutions. The first examines
switches between TCN and AGY (where N is any nucleotide and Y is a pyrimidine)
codons encoding absolutely conserved serine residues in a number of proteins from
diverse organisms. The second reveals double-nucleotide substitutions in primate
noncoding sequences. These two complementary approaches provide similar high
estimates for the rate of doublet substitutions, on the order of 0.1 per site per
billion years.
PMID- 10678839
TI - Treating young patients with breast cancer. The evidence suggests that all should
be treated with adjuvant therapy.
PMID- 10678840
TI - Is CS gas dangerous? Current evidence suggests not but unanswered questions
remain.
PMID- 10678841
TI - Cholesterol and strokes. Cholesterol lowering is indicated for strokes due to
carotid atheroma.
PMID- 10678842
TI - Innovation to prevent dependency in old age. Technological innovations may reduce
the cost burden of an ageing population.
PMID- 10678843
TI - Beds in the NHS. The National Bed Inquiry exposes contradictions in government
policy.
PMID- 10678844
TI - Government inquiry finds inadequate beds provision.
PMID- 10678845
TI - Police question medical MP over "euthanasia".
PMID- 10678846
TI - Clinic sued for unauthorized use of sperm.
PMID- 10678847
TI - In brief
PMID- 10678848
TI - Senators introduce bill to improve patient safety.
PMID- 10678849
TI - Doctor's book shames French prisons.
PMID- 10678850
TI - GMC speeds up disciplinary action against doctors.
PMID- 10678851
TI - GMC reprimands doctor for denigrating rival's service.
PMID- 10678852
TI - Bristol inquiry hears closing submissions.
PMID- 10678853
TI - Heart disease rising in central and eastern Europe.
PMID- 10678854
TI - Clinton outlaws genetic discrimination in federal jobs.
PMID- 10678855
TI - Nestle accused of breaking international code
PMID- 10678856
TI - Additives may be displayed on cigarette packs.
PMID- 10678857
TI - Extent and determinants of error in doctors' prognoses in terminally ill
patients: prospective cohort study.
AB - OBJECTIVE: To describe doctors' prognostic accuracy in terminally ill patients
and to evaluate the determinants of that accuracy. DESIGN: Prospective cohort
study. SETTING: Five outpatient hospice programmes in Chicago. PARTICIPANTS: 343
doctors provided survival estimates for 468 terminally ill patients at the time
of hospice referral. MAIN OUTCOME MEASURES: Patients' estimated and actual
survival. RESULTS: Median survival was 24 days. Only 20% (92/468) of predictions
were accurate (within 33% of actual survival); 63% (295/468) were overoptimistic
and 17% (81/468) were overpessimistic. Overall, doctors overestimated survival by
a factor of 5.3. Few patient or doctor characteristics were associated with
prognostic accuracy. Male patients were 58% less likely to have overpessimistic
predictions. Non-oncology medical specialists were 326% more likely than general
internists to make overpessimistic predictions. Doctors in the upper quartile of
practice experience were the most accurate. As duration of doctor-patient
relationship increased and time since last contact decreased, prognostic accuracy
decreased. CONCLUSION: Doctors are inaccurate in their prognoses for terminally
ill patients and the error is systematically optimistic. The inaccuracy is, in
general, not restricted to certain kinds of doctors or patients. These phenomena
may be adversely affecting the quality of care given to patients near the end of
life.
PMID- 10678858
TI - A memorable patient: The scars of the Jewish holocaust.
PMID- 10678859
TI - Factors influencing the effect of age on prognosis in breast cancer: population
based study.
AB - OBJECTIVE: To investigate whether young age at diagnosis is a negative prognostic
factor in primary breast cancer and how stage of disease at diagnosis and
treatment influences such an association. DESIGN: Retrospective cohort study
based on a population based database of patients with breast cancer containing
detailed information on tumour characteristics, treatment regimens, and survival.
SETTING: Denmark. SUBJECTS: 10 356 women with primary breast cancer who were less
than 50 years old at diagnosis. MAIN OUTCOME MEASURES: Relative risk of dying
within the first 10 years after diagnosis according to age at diagnosis after
adjustment for known prognostic factors and expected mortality. RESULTS: Overall,
young women with low risk disease who did not receive adjuvant treatment had a
significantly increased risk of dying; risk increased with decreasing age at
diagnosis (adjusted relative risk: 45-49 years (reference): 1; 40-44 years: 1.12
(95% confidence interval 0.89 to 1.40); 35-39 years: 1.40 (1.10 to 1.78); <35
years: 2.18 (1.64 to 2.89). However, no similar trend was seen in patients who
received adjuvant cytotoxic treatment. The increased risk in younger women who
did not receive adjuvant treatment compared with those who did remained when
women were grouped according to presence of node negative disease and by tumour
size. CONCLUSION: The negative prognostic effect of young age is almost
exclusively seen in women diagnosed with low risk disease who did not receive
adjuvant cytotoxic treatment. These results suggest that young women with breast
cancer, on the basis of age alone, should be regarded as high risk patients and
be given adjuvant cytotoxic treatment.
PMID- 10678861
TI - Effectiveness of modified release isosorbide mononitrate affected by incorrect
use.
PMID- 10678860
TI - Obstructive sleep apnoea syndrome as a risk factor for hypertension: population
study.
AB - OBJECTIVE: To assess whether sleep apnoea syndrome is an independent risk factor
for hypertension. DESIGN: Population study. SETTING: Sleep clinic in Toronto.
PARTICIPANTS: 2,677 adults, aged 20-85 years, referred to the sleep clinic with
suspected sleep apnoea syndrome. OUTCOME MEASURES: Medical history, demographic
data, morning and evening blood pressure, and whole night polysomnography.
RESULTS: Blood pressure and number of patients with hypertension increased
linearly with severity of sleep apnoea, as shown by the apnoea-hypopnoea index.
Multiple regression analysis of blood pressure levels of all patients not taking
antihypertensives showed that apnoea was a significant predictor of both systolic
and diastolic blood pressure after adjustment for age, body mass index, and sex.
Multiple logistic regression showed that each additional apnoeic event per hour
of sleep increased the odds of hypertension by about 1%, whereas each 10%
decrease in nocturnal oxygen saturation increased the odds by 13%. CONCLUSION:
Sleep apnoea syndrome is profoundly associated with hypertension independent of
all relevant risk factors.
PMID- 10678862
TI - Clopidogrel associated with acute arthritis.
PMID- 10678863
TI - Misunderstandings in prescribing decisions in general practice: qualitative
study.
AB - OBJECTIVES: To identify and describe misunderstandings between patients and
doctors associated with prescribing decisions in general practice. DESIGN:
Qualitative study. SETTING: 20 general practices in the West Midlands and south
east England. PARTICIPANTS: 20 general practitioners and 35 consulting patients.
MAIN OUTCOME MEASURES: Misunderstandings between patients and doctors that have
potential or actual adverse consequences for taking medicine. RESULTS: 14
categories of misunderstanding were identified relating to patient information
unknown to the doctor, doctor information unknown to the patient, conflicting
information, disagreement about attribution of side effects, failure of
communication about doctor's decision, and relationship factors. All the
misunderstandings were associated with lack of patients' participation in the
consultation in terms of the voicing of expectations and preferences or the
voicing of responses to doctors' decisions and actions. They were all associated
with potential or actual adverse outcomes such as non-adherence to treatment.
Many were based on inaccurate guesses and assumptions. In particular doctors
seemed unaware of the relevance of patients' ideas about medicines for successful
prescribing. CONCLUSIONS: Patients' participation in the consultation and the
adverse consequences of lack of participation are important. The authors are
developing an educational intervention that builds on these findings.
PMID- 10678864
TI - Mortality variations as a measure of general practitioner performance:
implications of the Shipman case.
PMID- 10678865
TI - Before birth
PMID- 10678867
TI - St Columba's case book
PMID- 10678866
TI - Tropical medicine.
PMID- 10678868
TI - ABC of heart failure. Management: digoxin and other inotropes, beta blockers, and
antiarrhythmic and antithrombotic treatment.
PMID- 10678869
TI - Internal and external morality of medicine: lessons from New Zealand.
PMID- 10678870
TI - Expressing the magnitude of adverse effects in case-control studies: "the number
of patients needed to be treated for one additional patient to be harmed".
PMID- 10678872
TI - The royal academy exhibition
PMID- 10678873
TI - Doctors write on patients' eye view of quality. Do patients want first class or
economy services?
PMID- 10678871
TI - "Where name and image meet"--the argument for "adrenaline".
PMID- 10678874
TI - Effectiveness of rivastigmine in Alzheimer's disease. Participation in trials
should be based on clinical uncertainty, not enforcement.
PMID- 10678875
TI - Accuracy of perceptions of hepatitis B and C status. Injecting drug users need
vaccination against hepatitis B.
PMID- 10678876
TI - Acupuncture may be associated with serious adverse events.
PMID- 10678877
TI - Healthcare providers in New Zealand and England could learn from each other.
PMID- 10678878
TI - Bible's stance on homosexuality. Bible shows no understanding of homosexual
orientation as mutually supportive and affirming.
PMID- 10678879
TI - Evidence produced in evidence based medicine needs to be relevant.
PMID- 10678880
TI - Fatigue and psychological distress. Statistics are improbable.
PMID- 10678881
TI - Evaluation of effect of changes is essential in policymaking.
PMID- 10678883
TI - Obituaries
PMID- 10678882
TI - Getting HIV/AIDS accepted on the political agenda.
PMID- 10678884
TI - NHS funding confused by lack of clarity
PMID- 10678885
TI - The magic bullet and other medical stories
PMID- 10678887
TI - ADAM interactive anatomy
PMID- 10678886
TI - Assuming the risk: the mavericks, the lawyers, and the whistleblowers who beat
big tobacco
PMID- 10678888
TI - Netlines
PMID- 10678889
TI - The stigma of schizophrenia.
PMID- 10678890
TI - Tropical medicine
PMID- 10678893
TI - No quick fixes
PMID- 10678892
TI - Lord, protect me from my friends
PMID- 10678895
TI - Chemotherapy may benefit young, low risk breast cancer patients
PMID- 10678894
TI - Doctors are overoptimistic in predicting survival for patients with cancer
PMID- 10678896
TI - Sleep apnoea contributes to hypertension
PMID- 10678897
TI - Doctors and patients misunder- stand each other when relevant information is not
exchanged
PMID- 10678898
TI - Mortality data for GPs may not identify future murders
PMID- 10678899
TI - Renaming adrenaline is wrong and may lead to errors
PMID- 10678900
TI - Differential bacterial survival, replication, and apoptosis-inducing ability of
Salmonella serovars within human and murine macrophages.
AB - Salmonella serovars are associated with human diseases that range from mild
gastroenteritis to host-disseminated enteric fever. Human infections by
Salmonella enterica serovar Typhi can lead to typhoid fever, but this serovar
does not typically cause disease in mice or other animals. In contrast, S.
enterica serovar Typhimurium and S. enterica serovar Enteritidis, which are
usually linked to localized gastroenteritis in humans and some animal species,
elicit a systemic infection in mice. To better understand these observations,
multiple strains of each of several chosen serovars of Salmonella were tested for
the ability in the nonopsonized state to enter, survive, and replicate within
human macrophage cells (U937 and elutriated primary cells) compared with murine
macrophage cells (J774A.1 and primary peritoneal cells); in addition, death of
the infected macrophages was monitored. The serovar Typhimurium strains all
demonstrated enhanced survival within J774A.1 cells and murine peritoneal
macrophages, compared with the significant, almost 100-fold declines in viable
counts noted for serovar Typhi strains. Viable counts for serovar Enteritidis
either matched the level of serovar Typhi (J774A. 1 macrophages) or were
comparable to counts for serovar Typhimurium (murine peritoneal macrophages).
Apoptosis was significantly higher in J774A.1 cells infected with serovar
Typhimurium strain LT2 compared to serovar Typhi strain Ty2. On the other hand,
serovar Typhi survived at a level up to 100-fold higher in elutriated human
macrophages and 2- to 3-fold higher in U937 cells compared to the serovar
Typhimurium and Enteritidis strains tested. Despite the differential
multiplication of serovar Typhi during infection of U937 cells, serovar Typhi
caused significantly less apoptosis than infections with serovar Typhimurium.
These observations indicate variability in intramacrophage survival and host
cytotoxicity among the various serovars and are the first to show differences in
the apoptotic response of distinct Salmonella serovars residing in human
macrophage cells. These studies suggest that nonopsonized serovar Typhimurium
enters, multiplies within, and causes considerable, acute death of macrophages,
leading to a highly virulent infection in mice (resulting in death within 14
days). In striking contrast, nonopsonized serovar Typhi survives silently and
chronically within human macrophages, causing little cell death, which allows for
intrahost dissemination and typhoid fever (low host mortality). The type of
disease associated with any particular serovar of Salmonella is linked to the
ability of that serovar both to persist within and to elicit damage in a specific
host's macrophage cells.
PMID- 10678901
TI - Reduced Th1, but not Th2, cytokine production by lymphocytes after in vivo
exposure of healthy subjects to endotoxin.
AB - Endotoxin (lipopolysaccharide [LPS]) tolerance is characterized by a reduced
capacity of monocytes to produce proinflammatory cytokines upon restimulation in
vitro. To determine whether LPS exposure induces a change in lymphocyte cytokine
production and whether this results in a shift in the T-helper 1 (Th1)/Th2
balance, whole blood obtained from seven healthy subjects before and after an
intravenous injection of LPS (4 ng/kg) was stimulated in vitro with the T-cell
stimulus anti-CD3/CD28 or staphylococcal enterotoxin B. Whole-blood production of
the Th1 cytokines gamma interferon (IFN-gamma) and interleukin-2 (IL-2) was
markedly reduced at 3 and 6 h, while the production of the Th2 cytokines IL-4 and
IL-5 was not influenced or was slightly increased. The IFN-gamma/IL-4 ratio was
strongly decreased at 6 h. Serum obtained after LPS exposure could slightly
inhibit the release of IFN-gamma but increased IL-4 production during stimulation
of blood drawn from subjects not previously exposed to LPS. Normal serum also
inhibited IFN-gamma production, albeit to a lesser extent. LPS exposure
influences lymphocyte cytokine production, resulting in a shift toward a Th2
cytokine response, an effect that may be mediated in part by soluble factors
present in serum after LPS administration in vivo.
PMID- 10678902
TI - Allele substitution of the streptokinase gene reduces the nephritogenic capacity
of group A streptococcal strain NZ131.
AB - To investigate the role of allelic variants of streptokinase in the pathogenesis
of acute poststreptococcal glomerulonephritis (APSGN), site-specific integration
plasmids were constructed, which contained either the non-nephritis-associated
streptokinase gene (skc5) from the group C streptococcal strain Streptococcus
equisimilis H46A or the nephritis-associated streptokinase gene (ska1) from the
group A streptococcal nephritogenic strain NZ131. The plasmids were introduced by
electroporation and homologous recombination into the chromosome of an isogenic
derivative of strain NZ131, in which the streptokinase gene had been deleted and
which had thereby lost its nephritogenic capacity in a mouse model of APSGN. The
introduction of a non-nephritis-associated allelic variant of streptokinase did
not rescue the nephritogenic capacity of the strain. The mutant and the wild-type
strains produced equivalent amounts of streptokinase. Complementation of the ska
deletion derivative with the original ska allele reconstituted the
nephritogenicity of wild-type NZ131. The findings support the hypothesis that the
role of streptokinase in the pathogenesis of APSGN is related to the allelic
variant of the protein.
PMID- 10678903
TI - B cells are essential for vaccination-induced resistance to virulent Toxoplasma
gondii.
AB - T lymphocytes and gamma interferon (IFN-gamma) are known mediators of immune
resistance to Toxoplasma gondii infection, but whether B cells also play an
important role is not clear. We have investigated this issue using B-cell
deficient (muMT) mice. If vaccinated with attenuated T. gondii tachyzoites, muMT
mice are susceptible to a challenge intraperitoneal infection with highly
virulent tachyzoites that similarly vaccinated B-cell-sufficient mice resist.
Susceptibility is evidenced by increased numbers of parasites at the challenge
infection site and by extensive mortality. The susceptibility of B-cell-deficient
mice does not appear to be caused by deficient T-cell functions or diminished
capacity of vaccinated and challenged B-cell-deficient mice to produce IFN-gamma.
Administration of Toxoplasma-immune serum, but not nonimmune serum, to vaccinated
B-cell-deficient mice significantly prolongs their survival after challenge with
virulent tachyzoites. Vaccinated mice lacking Fc receptors or the fifth component
of complement resist a challenge infection, suggesting that neither Fc-receptor
dependent phagocytosis of antibody-coated tachyzoites nor antibody-dependent
cellular cytotoxicity nor antibody-and-complement-dependent lysis of tachyzoites
is a crucial mechanism of resistance. However, Toxoplasma-immune serum
effectively inhibits the infection of host cells by tachyzoites in vitro.
Together, the results support the hypothesis that B cells are required for
vaccination-induced resistance to virulent tachyzoites in order to produce
antibodies and that antibodies may function protectively in vivo by blocking
infection of host cells by tachyzoites.
PMID- 10678904
TI - Shigella flexneri 2a strain CVD 1207, with specific deletions in virG, sen, set,
and guaBA, is highly attenuated in humans.
AB - A phase 1 clinical trial was conducted among 35 healthy adult volunteers to
evaluate the safety, immunogenicity, and shedding of different doses of CVD 1207,
a live attenuated Shigella flexneri 2a vaccine candidate with specific deletion
mutations in virG, sen, set, and guaBA. CVD 1207 retains the ability to invade
epithelial cells but cannot effectively spread intercellularly after invasion
(DeltavirG), does not produce enterotoxin (Deltasen and Deltaset), and has
limited proliferation in vivo (DeltaguaBA). In a consecutive fashion, groups of
three to seven subjects ingested a single oral dose of CVD 1207 at an inoculum of
either 10(6), 10(7), 10(8), 10(9), or 10(10) CFU. CVD 1207 was remarkably well
tolerated at inocula as high as 10(8) CFU. In comparison, one of 12 subjects who
received 10(9) CFU experienced mild diarrhea and another experienced a single
episode of emesis. One of five subjects who received 10(10) CFU experienced
watery diarrhea and emesis. All subjects who ingested doses of 10(8) to 10(10)
CFU excreted the vaccine; in 23 of 25, the duration of excretion was =3 days. A
dose-related, immunoglobulin A antibody-secreting cell (ASC) response to S.
flexneri 2a O-specific lipopolysaccharide was seen, with geometric mean peak
values of 6.1 to 35.2 ASCs/10(6) peripheral blood mononuclear cells (PBMC) among
recipients of 10(7) to 10(10) CFU. The cytokine response to Shigella-specific
antigens observed in volunteers' PBMC following vaccination suggested a Th1
pattern with stimulation of gamma interferon and absence of interleukin 4 (IL-4)
or IL-5. CVD 1207 represents a Shigella live oral vaccine strain prepared from
wild-type S. flexneri 2a by rational use of recombinant DNA technology that
achieves a remarkable degree of attenuation compared with earlier recombinant
strains, even when administered at high dosage.
PMID- 10678906
TI - Construction and characterization of an agr deletion mutant of Staphylococcus
epidermidis.
AB - The physiological significance of the accessory gene regulator (agr) system of
Staphylococcus epidermidis was investigated by construction of an agr deletion
mutant via allelic replacement with a spectinomycin resistance cassette. Sodium
dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed
that the protein pattern was strongly altered in the mutant; the amounts of most
surface proteins were higher, whereas the amounts of most exoproteins were lower.
The agr system of S. epidermidis thus appears to have an important impact on
growth phase-dependent protein synthesis as has been shown for Staphylococcus
aureus. The activity of the exoenzymes lipase and protease, assumed to be
involved in staphylococcal pathogenicity, was investigated by agar diffusion
assays and SDS-PAGE activity staining. A general reduction of these enzyme
activities in the agr mutant was found. The difference in overall lipase activity
was small, but zymographic analysis suggested a clear defect in lipase processing
in the agr mutant.
PMID- 10678905
TI - Cloning of the gene encoding a 22-kilodalton cell surface antigen of
Mycobacterium bovis BCG and analysis of its potential for DNA vaccination against
tuberculosis.
AB - Using spleen cells from mice vaccinated with live Mycobacterium bovis BCG, we
previously generated three monoclonal antibodies reactive against a 22-kDa
protein present in mycobacterial culture filtrate (CF) (K. Huygen et al., Infect.
Immun. 61:2687-2693, 1993). These monoclonal antibodies were used to screen an M.
bovis BCG genomic library made in phage lambdagt11. The gene encoding a 233-amino
acid (aa) protein, including a putative 26-aa signal sequence, was isolated, and
sequence analysis indicated that the protein was 98% identical with the M.
tuberculosis Lppx protein and that it contained a sequence 94% identical with the
M. leprae 38-mer polypeptide 13B3 recognized by T cells from killed M. leprae
immunized subjects. Flow cytometry and cell fractionation demonstrated that the
22-kDa CF protein is also highly expressed in the bacterial cell wall and
membrane compartment but not in the cytosol. C57BL/6, C3H, and BALB/c mice were
vaccinated with plasmid DNA encoding the 22-kDa protein and analyzed for immune
response and protection against intravenous M. tuberculosis challenge. Whereas
DNA vaccination induced elevated antibody responses in C57BL/6 and particularly
in C3H mice, Th1-type cytokine response, as measured by interleukin-2 and gamma
interferon secretion, was only modest, and no protection against intravenous M.
tuberculosis challenge was observed in any of the three mouse strains tested.
Therefore, the 22-kDa antigen seems to have little potential for a DNA vaccine
against tuberculosis, but it may be a good candidate for a mycobacterial antigen
detection test.
PMID- 10678907
TI - Decreased production of local immunoglobulin A to Pneumocystis carinii in
bronchoalveolar lavage fluid from human immunodeficiency virus-positive patients.
AB - An enzyme-linked immunosorbent assay and a Western blot analysis were developed
to study the antibody response to Pneumocystis carinii in serum and
bronchoalveolar lavage fluid from 27 human immunodeficiency virus 27 (HIV)
infected patients with P. carinii pneumonia (Pcp), 32 patients without Pcp, and
51 HIV-negative controls. Urea was used for the correct dilution of epithelial
lining fluid, and albumin was used to evaluate transudation from plasma for the
assessment of local production of antibodies to P. carinii. By contrast with
those of immunoglobulin G (IgG), IgA responses to P. carinii were increased in
serum from HIV-positive patients compared to negative controls. Local production
of antibodies to P. carinii, especially IgA, was decreased in patients with Pcp.
In a study of 10 patients of each group, IgG and IgA responses to gp116 from P.
carinii were lower in patients with Pcp than in other groups. These results
suggest that, in addition to alveolar macrophages, local antibodies may play a
role in host defense against P. carinii.
PMID- 10678908
TI - A shift from oral to blood pH is a stimulus for adaptive gene expression of
Streptococcus gordonii CH1 and induces protection against oxidative stress and
enhanced bacterial growth by expression of msrA.
AB - Viridans group streptococci (VS) from the oral cavity entering the bloodstream
may initiate infective endocarditis (IE). We aimed to identify genes expressed in
response to a pH increase from slightly acidic (pH 6.2) to neutral (pH 7.3) as
encountered by VS entering the bloodstream from the oral cavity. Using a recently
developed promoter-screening vector, we isolated five promoter fragments from the
genomic DNA of Streptococcus gordonii CH1 responding to this stimulus. No common
regulatory sequences were identified in these promoter fragments that could
account for the coordinate expression of the corresponding genes. One of the
isolated fragments contained the promoter region and 5' end of a gene highly
homologous to the methionine sulfoxide reductase gene (msrA) of various bacterial
and eukaryotic species. This gene has been found to be activated in S. gordonii
strain V288 in a rabbit model of IE (A. O. Kilic, M. C. Herzberg, M. W. Meyer, X.
Zhao, and L. Tao, Plasmid 42:67-72, 1999). We isolated and characterized the msrA
gene of S. gordonii CH1 and constructed a chromosomal insertion mutant. This
mutant was more sensitive to hydrogen peroxide, suggesting a role for the
streptococcal MsrA in protecting against oxidative stress. Moreover, MsrA
appeared to be important for the growth of S. gordonii CH1 under aerobic and
anaerobic conditions. Both these properties of MsrA may contribute to the ability
of S. gordonii to cause IE.
PMID- 10678909
TI - The Legionella pneumophila iraAB locus is required for iron assimilation,
intracellular infection, and virulence.
AB - Legionella pneumophila, a facultative intracellular parasite of human alveolar
macrophages and protozoa, causes Legionnaires' disease. Using mini-Tn10
mutagenesis, we previously isolated a L. pneumophila mutant that was
hypersensitive to iron chelators. This mutant, NU216, and its allelic equivalent,
NU216R, were also defective for intracellular infection, particularly in iron
deficient host cells. To determine whether NU216R was attenuated for virulence,
we assessed its ability to cause disease in guinea pigs following intratracheal
inoculation. NU216R-infected animals yielded 1,000-fold fewer bacteria from their
lungs and spleen compared to wild-type-130b-infected animals that had received a
50-fold-lower dose. Moreover, NU216R-infected animals subsequently cleared the
bacteria from these sites. While infection with 130b resulted in high fever,
weight loss, and ruffled fur, inoculation with NU216R did not elicit any signs of
disease. DNA sequence analysis revealed that the transposon insertion in NU216R
lies in the first open reading frame of a two-gene operon. This open reading
frame (iraA) encodes a 272-amino-acid protein that shows sequence similarity to
methyltransferases. The second open reading frame (iraB) encodes a 501-amino-acid
protein that is highly similar to di- and tripeptide transporters from both
prokaryotes and eukaryotes. Southern hybridization analyses determined that the
iraAB locus was largely limited to strains of L. pneumophila, the most pathogenic
of the Legionella species. A newly derived mutant containing a targeted
disruption of iraB showed reduced ability to grow under iron-depleted
extracellular conditions, but it did not have an infectivity defect in the
macrophage-like U937 cells. These data suggest that iraA is critical for
virulence of L. pneumophila while iraB is involved in a novel method of iron
acquisition which may utilize iron-loaded peptides.
PMID- 10678910
TI - Eukaryotic cell uptake of heparin-coated microspheres: a model of host cell
invasion by Chlamydia trachomatis.
AB - Using polystyrene microspheres coated with heparin or heparan sulfate, it was
shown that coated microspheres specifically bound eukaryotic cells and were
endocytosed by nonprofessional phagocytic cells. Coated microspheres displayed
properties of binding to eukaryotic cells that were similar to those of
chlamydiae, and the microspheres were competitively inhibited by chlamydial
organisms. Endocytosis of heparin-coated beads resulted in the tyrosine
phosphorylation of a similar set of host proteins as did endocytosis of
chlamydiae; however, unlike viable chlamydial organisms, which prevent
phagolysosomal fusion, endocytosed beads were trafficked to a lysosomal
compartment. These findings suggest that heparin-coated beads and Chlamydia
trachomatis enter eukaryotic cells by similar pathways.
PMID- 10678911
TI - Cloning of porcine NRAMP1 and its induction by lipopolysaccharide, tumor necrosis
factor alpha, and interleukin-1beta: role of CD14 and mitogen-activated protein
kinases.
AB - The gene for natural resistance-associated macrophage protein 1 (NRAMP1) plays a
dominant role in controlling the resistance of inbred mice to infection with
intracellular bacteria, such as Mycobacteria, Salmonella, and Leishmania. NRAMP1
is a membrane protein with a consensus transport motif present in one of the
intracellular loops. Although its functions remain unclear, recent clues suggest
that NRAMP1 protein plays a potential role in ion transport, which presumably
accounts for the ability of this single protein to regulate the intraphagosomal
replication of several species of antigenically unrelated intracellular
pathogens. Expression of NRAMP1 in mice can be induced by lipopolysaccharide
(LPS) or bacterial infection; however, little is known about the mechanisms of
induction. Here, we report the cloning of the full-length cDNA for porcine
NRAMP1, which had over 85% identity in amino acid sequence to its congeners from
humans, mice, cattle, and sheep. As for its mammalian congeners, expression of
porcine NRAMP1 mRNA was cell and tissue specific and was highest in macrophages.
Investigation of the molecular mechanisms by which NRAMP1 is induced showed that
LPS-induced expression in macrophages, neutrophils, and peripheral blood
mononuclear cells was time and dose dependent and was mediated primarily through
CD14. Induction of NRAMP1 required de novo protein synthesis, and mitogen
activated protein kinases (MAPK) were essential. Blockage of either p38 or p42/44
MAPK pathways suppressed the expression of NRAMP1 to basal levels. These findings
suggest that bacterial infection and proinflammatory mediators induce NRAMP1
expression via activation of MAPK pathways.
PMID- 10678912
TI - New method to generate enzymatically deficient Clostridium difficile toxin B as
an antigen for immunization.
AB - The family of the large clostridial cytotoxins, encompassing Clostridium
difficile toxins A and B as well as the lethal and hemorrhagic toxins from
Clostridium sordellii, monoglucosylate the Rho GTPases by transferring a glucose
moiety from the cosubstrate UDP-glucose. Here we present a new detoxification
procedure to block the enzyme activity by treatment with the reactive UDP-2', 3'
dialdehyde to result in alkylation of toxin A and B. Alkylation is likely to
occur in the catalytic domain, because the native cosubstrate UDP-glucose
completely protected the toxins from inactivation and the alkylated toxin
competes with the native toxin at the cell receptor. Alkylated toxins are good
antigens resulting in antibodies recognizing only the C-terminally located
receptor binding domain, whereas formaldehyde treatment resulted in antibodies
recognizing both the receptor binding domain and the catalytic domain, indicating
that the catalytic domain is concealed under native conditions. Antibodies
against the native catalytic domain (amino acids 1 through 546) and those
holotoxin antibodies recognizing the catalytic domain inhibited enzyme activity.
However, only antibodies against the receptor binding domain protected intact
cells from the cytotoxic activity of toxin B, whereas antibodies against the
catalytic domain were protective only when inside the cell.
PMID- 10678913
TI - Cytotoxic activity of coagulase-negative staphylococci in bovine mastitis.
AB - Secreted toxins play important roles in the pathogenesis of bacterial infections.
In this study, we examined the presence of secreted cytotoxic factors of
coagulase-negative staphylococci (CoNS) from bovine clinical and subclinical
mastitis. A 34- to 36-kDa protein with cell-rounding cytotoxic activity was found
in many CoNS strains, especially in Staphylococcus chromogenes strains. The
protein caused cell detachment and cell rounding in several cell lines, including
HEp-2, Int 407, CHO-K1, and Y-1 cells. Native protein recovered from nondenatured
polyacrylamide gel electrophoresis showed both cytotoxic activity and casein
hydrolysis activity. The purified protein had a pH optimal at 7.2 to 7.5 and a pI
of 5.1 and was heat labile. The proteolytic activity could be inhibited by zinc
and metal specific inhibitors such as 1, 10-phenanthroline and EDTA, indicating
that it is a metalloprotease. Protein mass analysis and peptide sequencing
indicated that the protein is a novel metalloprotease. Different bacterial
strains expressed variable levels of 34- to 36-kDa protease, which may provide an
indication of strain virulence.
PMID- 10678914
TI - Salmonella enterica serovar typhimurium surA mutants are attenuated and effective
live oral vaccines.
AB - A previously described attenuated TnphoA mutant (BRD441) of Salmonella enterica
serovar Typhimurium C5 (I. Miller, D. Maskell, C. Hormaeche, K. Johnson, D.
Pickard, and G. Dougan, Infect. Immun. 57:2758-2763, 1989) was characterized, and
the transposon was shown to be inserted in surA, a gene which encodes a
peptidylprolyl-cis, trans-isomerase. A defined surA deletion mutation was
introduced into S. enterica serovar Typhimurium C5 and the mutant strain, named
S. enterica serovar Typhimurium BRD1115, was extensively characterized both in
vitro and in vivo. S. enterica serovar Typhimurium BRD1115 was found to be
defective in the ability to adhere to and invade eukaryotic cells. Furthermore,
S. enterica serovar Typhimurium BRD1115 was attenuated by at least 3 log units
when administered orally or intravenously to BALB/c mice. Complementation of the
mutation with a plasmid carrying the intact surA gene almost completely restored
the virulence of BRD1115. In addition, S. enterica serovar Typhimurium BRD1115
demonstrated potential as a vaccine candidate, since mice immunized with BRD1115
were protected against subsequent challenge with S. enterica serovar Typhimurium
C5. S. enterica serovar Typhimurium BRD1115 also showed potential as a vehicle
for the effective delivery of heterologous antigens, such as the nontoxic,
protective fragment C domain of tetanus toxin, to the murine immune system.
PMID- 10678915
TI - Distribution of core oligosaccharide types in lipopolysaccharides from
Escherichia coli.
AB - In the lipopolysaccharides of Escherichia coli there are five distinct core
oligosaccharide (core OS) structures, designated K-12 and R1 to R4. The objective
of this work was to determine the prevalences of these core OS types within the
species. Unique sequences in the waa (core OS biosynthesis) gene operon were used
to develop a PCR-based system that facilitated unequivocal determination of the
core OS types in isolates of E. coli. This system was applied to the 72 isolates
in the E. coli ECOR collection, a compilation of isolates that is considered to
be broadly representative of the genetic diversity of the species. Fifty (69. 4%)
of the ECOR isolates contained the R1 core OS, 8 (11.1%) were representatives of
R2, 8 (11.1%) were R3, 2 (2.8%) were R4, and only 4 (5.6%) were K-12. R1 is the
only core OS type found in all four major phylogenetic groups (A, B1, B2, and D)
in the ECOR collection. Virulent extraintestinal pathogenic E. coli isolates tend
to be closely related to group B2 and, to a lesser extent, group D isolates. All
of the ECOR representatives from the B2 and D groups had the R1 core OS. In
contrast, commensal E. coli isolates are more closely related to group A, which
contains isolates representing each of the five core OS structures. R3 was the
only core OS type found in 38 verotoxigenic E. coli (VTEC) isolates from humans
and cattle belonging to the common enterohemorrhagic E. coli serogroups O157,
O111, and O26. Although isolates from other VTEC serogroups showed more core OS
diversity, the R3 type (83.1% of all VTEC isolates) was still predominant. When
non-VTEC commensal isolates from cattle were analyzed, it was found that most
possessed the R1 core OS type.
PMID- 10678916
TI - Intracellular infection by the human granulocytic ehrlichiosis agent inhibits
human neutrophil apoptosis.
AB - In patients with human granulocytic ehrlichiosis (HGE), the HGE agent has been
seen only in the peripheral blood granulocytes, which have a life span too short
for ehrlichial proliferation. To determine if the HGE agent delays the apoptosis
of human peripheral blood neutrophils for its advantage, peripheral blood
granulocytes consisting mostly of neutrophils were incubated with freshly freed
host cell-free HGE agent in vitro. The HGE agent induced a significant delay in
morphological apoptosis and the cytoplasmic appearance of histone-associated DNA
fragments in the granulocytes. This antiapoptotic effect was dose dependent.
Although much weaker than the HGE agent freshly freed from the host cells,
noninfectious purified HGE agent stored frozen and thawed also had antiapoptotic
effect, which was lost with proteinase K treatment but not with periodate
treatment. Treatment of neutrophils with a transglutaminase inhibitor,
monodansylcadaverine, blocked the antiapoptotic effect of the HGE agent. Addition
of oxytetracycline, however, did not prevent or reverse the antiapoptotic effect
of the HGE agent. These results suggest that binding of a protein component(s) of
the HGE agent to neutrophils and subsequent cross-linking and/or internalization
of the receptor and ehrlichiae are required for antiapoptotic signaling, but
ehrlichial protein synthesis and/or proliferation is not required. MG-132, a
proteasome inhibitor, and cycloheximide accelerated the apoptosis of neutrophils
and overrode the antiapoptotic effect of the HGE agent. Studies with specific
inhibitors suggest that protein kinase A, NF-kappaB, and interleukin 1beta are
not involved in the antiapoptotic mechanism of the HGE agent.
PMID- 10678917
TI - Mechanisms of the proinflammatory response of endothelial cells to Candida
albicans infection.
AB - Endothelial cells can influence significantly the host inflammatory response
against blood-borne microbial pathogens. Previously, we found that endothelial
cells respond to in vitro infection with Candida albicans by secreting
interleukin 8 (IL-8) and expressing E-selectin, intercellular adhesion molecule 1
(ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1). We have now examined
the mechanisms mediating this endothelial cell response. We determined that C.
albicans stimulated endothelial cells to synthesize tumor necrosis factor alpha
(TNF-alpha), which in turn induced these infected cells to secrete IL-8 and
express E-selectin by an autocrine mechanism. Expression of VCAM-1 was mediated
not only by TNF-alpha but also by IL-1alpha and IL-1beta, all of which were
synthesized by endothelial cells in response to C. albicans. These three
cytokines remained primarily cell associated rather than being secreted. Candidal
induction of ICAM-1 expression was independent of TNF-alpha, IL-1alpha, and IL
1beta. These observations demonstrate that different proinflammatory endothelial
cell responses to C. albicans are induced by distinct mechanisms. A clear
understanding of these mechanisms is important for therapeutically modulating the
endothelial cell response to C. albicans and perhaps other opportunistic
pathogens that disseminate hematogenously.
PMID- 10678919
TI - Cytokines in Mycoplasma hyorhinis-induced arthritis in pigs bred selectively for
high and low immune responses.
AB - Yorkshire pigs were bred selectively for high and low immune responses (H and L
pigs, respectively) based on multiple antibody (Ab) and cell-mediated immune
response traits. In a previous experiment, generation 4 (G4) pigs of each line
were infected with Mycoplasma hyorhinis. High responders had a more rapid and
higher Ab response and less polyserositis, but arthritis was more severe in H
pigs than in L pigs. To test the hypothesis that line differences were
attributable to differential expression of cytokines, M. hyorhinis infection was
induced in pigs of G8. Arthritis was more severe clinically (P, =0.05) and
postmortem (P, =0.001) when M. hyorhinis CFU were more numerous in synovial
fluid (SF) of H pigs than of L pigs (P, =0.03). In H pigs but not L pigs, CFU
and lesion scores were correlated positively. In H pigs, infection increased the
frequency of expression of mRNAs for interleukin-8 (IL-8), IL-10, and tumor
necrosis factor alpha (TNF-alpha) in mononuclear cells from synovial membranes
(SM). In L pigs, IL-1alpha, IL-6, IL-10, and TNF-alpha mRNAs were increased in
frequency of expression. The quantity of the cytokine message for IL-6 was
increased in infected H pigs. For L pigs, infection increased the cytokine
message for IL-1alpha, IL-6, IL-10, and TNF-alpha. IL-6 in SM and gamma
interferon (IFN-gamma) in SF were produced at a higher copy number in H pigs than
in L pigs after infection. For H pigs, there were no positive rank correlations
between lesion or CFU scores and cytokines. For L pigs, IL-1alpha, IL-8, IL-10,
and TNF-alpha in SM correlated with CFU, while IL-6, TNF-beta, and IFN-gamma in
SF correlated with CFU. Lesion score in L pigs correlated with IL-1alpha in SF.
While these results indicate that H and L pigs differ in the cytokine response to
M. hyorhinis infection, they do not confirm a characteristic cytokine response in
association with the relative susceptibility to infection and arthritis observed
in H pigs.
PMID- 10678918
TI - Modulation of cytokine profiles by the Mycoplasma superantigen Mycoplasma
arthritidis mitogen parallels susceptibility to arthritis induced by M.
arthritidis.
AB - Mycoplasma arthritidis mitogen (MAM) is a potent superantigen secreted by M.
arthritidis, an agent of murine arthritis. Here we compare the abilities of MAM
to induce a panel of cytokines in vitro and in vivo in BALB/c and C3H/HeJ mouse
strains that differ in susceptibility to mycoplasmal arthritis. Splenocytes from
both mouse strains produced high levels of all cytokines by 24 h following in
vitro exposure to MAM. No differences in cytokine profiles were seen irrespective
of the MAM dose. However, there were striking differences in cytokine profiles
present in supernatants of splenocytes that had been collected from mice after
intravenous (i.v. ) injection of MAM and subsequently rechallenged with MAM in
vitro. Splenocytes collected 24 and 72 h after i.v. injection of MAM and
challenged in vitro with MAM showed the most marked divergence in the secreted
cytokines. Type 1 cytokines were markedly elevated in C3H/HeJ cell supernatants,
whereas they were depressed or remained low in BALB/c cell supernatants. In
contrast, the levels of type 2 cytokines were all greatly increased in BALB/c
cell cultures but were decreased or remained low in C3H/HeJ supernatants.
Interleukin-12 mRNA and protein was also markedly elevated in C3H/HeJ mice, as
were the levels of immunoglobulin G2a. The data indicate a major skewing in
cytokine profiles to a type 1 inflammatory response in C3H/HeJ mice but to a
protective type 2 response in BALB/c mice. These cytokine changes appear to be
associated with the severe arthritis in C3H/HeJ mice following injection of M.
arthritidis in comparison to the mild disease seen in injected BALB/c mice.
PMID- 10678920
TI - Synthetic peptide immunogens elicit polyclonal and monoclonal antibodies specific
for linear epitopes in the D motifs of Staphylococcus aureus fibronectin-binding
protein, which are composed of amino acids that are essential for fibronectin
binding.
AB - A fibronectin (Fn)-binding adhesin of Staphylococcus aureus contains three tandem
37- or 38-amino-acid motifs (D1, D2, and D3), which function to bind Fn. Plasma
from patients with S. aureus infections contain antibodies that preferentially
recognize ligand induced binding sites in the D motifs and do not inhibit Fn
binding (F. Casolini, L. Visai, D. Joh, P. G. Conaldi, A. Toniolo, M. Hook, and
P. Speziale, Infect. Immun. 66:5433-5442, 1998). To eliminate the influence of Fn
binding on antibody development, we used synthetic peptide immunogens D1(21-34)
and D3(20-33), which each contain a conserved pattern of amino acids that is
essential for Fn binding but which cannot bind Fn without N- or C-terminal
extensions. The D3(20-33) immunogen promoted the production of polyclonal
antibodies that were 10-fold more effective as inhibitors of Fn-binding to the D3
motif than antibodies obtained by immunizing with an extended peptide D3(16-36),
which exhibits functional Fn binding. The D3(20-33) immunogen also facilitated
the production of a monoclonal antibody, 9C3, which was highly specific for the
epitope SVDFEED, and abolished Fn binding by the D3 motif. When mixed with
polyclonal anti-D1(21-34) immunoglobulin G, 70% inhibition of Fn binding to the
three tandem D motifs was achieved compared to no more than 30% inhibition with
either antibody preparation alone. Therefore, by immunizing with short synthetic
peptides that are unable to bind Fn, we have effectively stimulated the
production of antibodies specific for epitopes comprised of amino acids that are
essential for Fn binding. Although these epitopes occur within a conserved
pattern of amino acids that is required for Fn binding, the antibodies recognized
specific linear epitope sequences and not a conserved structure common to all
repeated motifs.
PMID- 10678921
TI - Actinobacillus pleuropneumoniae iron transport: a set of exbBD genes is
transcriptionally linked to the tbpB gene and required for utilization of
transferrin-bound iron.
AB - Upon iron restriction, Actinobacillus pleuropneumoniae has been shown to express
the transferrin-binding proteins TbpB and TbpA, both of which have been implied
to be important virulence factors. In order to identify additional iron-regulated
proteins, we cloned and analyzed the region upstream of the transferrin-binding
protein genes in an A. pleuropneumoniae serotype 7 strain. We located immediately
upstream of the tbpB gene two open reading frames which were 43% homologous to
the neisserial ExbBD protein genes. By raising specific antibodies, we showed
that ExbB is expressed under iron-limiting growth conditions only, and RT-PCR
analysis revealed that the exbBD genes and the tbpB gene are transcribed on a
single polycistronic mRNA. By constructing an isogenic and nonpolar exbBD mutant,
we showed that the exbBD genes are required by A. pleuropneumoniae for
utilization of transferrin-bound iron. Using PCR and Western blotting, we showed
that the genetic organization found in A. pleuropneumoniae serotype 7 is similar
in all 12 A. pleuropneumoniae serotype reference strains.
PMID- 10678922
TI - In vitro and in vivo analyses of constitutive and in vivo-induced promoters in
attenuated vaccine and vector strains of Vibrio cholerae.
AB - The optimal promoter for in vivo expression of heterologous antigens by live,
attenuated vaccine vector strains of Vibrio cholerae is unclear; in vitro
analyses of promoter activity may not accurately predict expression of antigens
in vivo. We therefore introduced plasmids expressing the B subunit of cholera
toxin (CtxB) under the control of a number of promoters into V. cholerae vaccine
strain Peru2. We evaluated the tac promoter, which is constitutively expressed in
V. cholerae, as well as the in vivo-induced V. cholerae heat shock htpG promoter
and the in vivo-induced V. cholerae iron-regulated irgA promoter. The
functionality of all promoters was confirmed in vitro. In vitro antigenic
expression was highest in vaccine strains expressing CtxB under the control of
the tac promoter (2 to 5 microgram/ml/unit of optical density at 600 nm
[OD(600)]) and, under low-iron conditions, in strains containing the irgA
promoter (5 microgram/ml/OD(600)). We orally inoculated mice with the various
vaccine strains and used anti-CtxB immune responses as a marker for in vivo
expression of CtxB. The vaccine strain expressing CtxB under the control of the
tac promoter elicited the most prominent specific anti-CtxB responses in vivo
(serum immunoglobulin G [IgG], P = 0.05; serum IgA, P = 0.05; stool IgA, P
= 0.05; bile IgA, P = 0.05), despite the finding that the tac and irgA
promoters expressed equivalent amounts of CtxB in vitro. Vibriocidal antibody
titers were equivalent in all groups of animals. Our results indicate that in
vitro assessment of antigen expression by vaccine and vector strains of V.
cholerae may correlate poorly with immune responses in vivo and that of the
promoters examined, the tac promoter may be best suited for expression from
plasmids of at least certain heterologous antigens in such strains.
PMID- 10678923
TI - Emerging family of proline-specific peptidases of Porphyromonas gingivalis:
purification and characterization of serine dipeptidyl peptidase, a structural
and functional homologue of mammalian prolyl dipeptidyl peptidase IV.
AB - Porphyromonas gingivalis is an asaccharolytic and anaerobic bacterium that
possesses a complex proteolytic system which is essential for its growth and
evasion of host defense mechanisms. In this report, we show the purification and
characterization of prolyl dipeptidyl peptidase IV (DPPIV) produced by this
organism. The enzyme was purified to homogeneity, and its enzymatic activity and
biochemical properties were investigated. P. gingivalis DPPIV, like its human
counterpart, is able to cleave the N terminus of synthetic oligopeptides with
sequences analogous to those of interleukins 1beta and 2. Additionally, this
protease hydrolyzes biologically active peptides including substance P, fibrin
inhibitory peptide, and beta-casomorphin. Southern blot analysis of genomic DNA
isolated from several P. gingivalis strains reveal that a single copy of the
DPPIV gene was present in all strains tested.
PMID- 10678924
TI - Malaria infection induces rapid elevation of the soluble Fas ligand level in
serum and subsequent T lymphocytopenia: possible factors responsible for the
differences in susceptibility of two species of Macaca monkeys to Plasmodium
coatneyi infection.
AB - The intraerythrocytic stage of the simian malaria parasite Plasmodium coatneyi
(CDC strain) was intravenously inoculated into two species of macaques with
different susceptibilities to infection with this parasite, including four
Japanese macaques (Macaca fuscata) and three cynomolgus macaques (M.
fascicularis). The Japanese macaques infected with P. coatneyi developed severe
clinical manifestations similar to those of severe human malaria and eventually
became moribund, while the infected cynomolgus macaques, natural hosts of the
parasite, exhibited no severe manifestation of disease except anemia and finally
recovered from the infection. In the infected Japanese macaques, peripheral
CD4(+) and CD8(+) T-cell populations were markedly decreased and fragmentation of
chromosomal DNA in peripheral blood mononuclear cells was detected during the
terminal period of infection, suggesting that apoptotic cell death was
responsible at least in part for the T lymphocytopenia. Furthermore, soluble Fas
ligand levels in sera of the infected Japanese macaques increased gradually to a
markedly high level of 28. 83 +/- 10.56 pg/ml (n = 4) when the animals became
moribund. On the other hand, none of the infected cynomolgus monkeys exhibited
either T lymphocytopenia or elevated soluble Fas ligand level. These findings
suggest that differences in immune response between the two species of macaque
tested accounted for the contrasting outcomes after infection with the same
isolate of malarial parasite, and in particular that a profound T lymphocytopenia
due to Fas-derived apoptosis played a role in the fatal course of malaria in the
infected Japanese macaques.
PMID- 10678925
TI - Tumor necrosis factor alpha and interleukin 1beta up-regulate gastric mucosal Fas
antigen expression in Helicobacter pylori infection.
AB - Fas-mediated gastric mucosal apoptosis is gaining attention as a cause of tissue
damage due to Helicobacter pylori infection. We explored the effects of H. pylori
directly, and the effects of the inflammatory environment established subsequent
to H. pylori infection, on Fas-mediated apoptosis in a nontransformed gastric
mucosal cell line (RGM-1). Exposure to H. pylori-activated peripheral blood
mononuclear cells (PBMCs), but not H. pylori itself, induced Fas antigen (Fas Ag)
expression, indicating a Fas-regulatory role for inflammatory cytokines in this
system. Of various inflammatory cytokines tested, only interleukin 1beta and
tumor necrosis factor alpha induced Fas Ag expression, and removal of either of
these from the conditioned medium abrogated the response. When exposed to Fas
ligand, RGM-1 cells treated with PBMC-conditioned medium underwent massive and
rapid cell death, interestingly, with a minimal effect on total cell numbers
early on. Cell cycle analysis revealed a substantial increase in S phase cells
among cells exposed to Fas ligand, suggesting an increase in their proliferative
response. Taken together, these data indicate that the immune environment
secondary to H. pylori infection plays a critical role in priming gastric mucosal
cells to undergo apoptosis or to proliferate based upon their Fas Ag status.
PMID- 10678926
TI - Phase 2 clinical trial of attenuated Salmonella enterica serovar typhi oral live
vector vaccine CVD 908-htrA in U.S. volunteers.
AB - Salmonella enterica serovar Typhi strain CVD 908-htrA is a live attenuated strain
which may be useful as an improved oral typhoid vaccine and as a vector for
cloned genes of other pathogens. We conducted a phase 2 trial in which 80 healthy
adults received one of two dosage levels of CVD 908-htrA in a double-blind,
placebo-controlled, crossover study. There were no differences in the rates of
side effects among volunteers who received high-dose vaccine (4.5 x 10(8) CFU),
lower-dose vaccine (5 x 10(7) CFU), or placebo in the 21 days after vaccination,
although recipients of high-dose vaccine (8%) had more frequent diarrhea than
placebo recipients (0%) in the first 7 days. Seventy-seven percent and 46% of
recipients of high- and lower-dose vaccines, respectively, briefly excreted
vaccine organisms in their stools. All blood cultures were negative. Antibody
secreting cells producing antilipopolysaccharide (LPS) immunoglobulin A (IgA)
were detected in 100 and 92% of recipients of high- and lower-dose vaccines,
respectively. Almost half the volunteers developed serum anti-LPS IgG. Lymphocyte
proliferation and gamma interferon production against serovar Typhi antigens
occurred in a significant proportion of vaccinees. This phase 2 study supports
the further development of CVD 908-htrA as a single-dose vaccine against typhoid
fever and as a possible live vector for oral delivery of other vaccine antigens.
PMID- 10678927
TI - Metalloprotease activity in a small heat shock protein of the human malaria
parasite Plasmodium vivax.
AB - The malaria parasite affects millions of people each year, lives and multiplies
in two different hosts, and synthesizes a large number of proteases and heat
shock proteins (HSPs) for its survival. We describe here the characterization of
a metalloprotease activity which resides in the small HSP (PVHSP28) of the common
but noncultivable human malaria parasite Plasmodium vivax. The protein is
expressed by erythrocytic stages of the parasite. It is expressed as a
approximately 55-kDa polypeptide which is then processed to the 28-kDa mature
protein. The latter was found to be an active protease in gelatin zymography.
This protease showed its optimal activity at 37 degrees C (pH 7.6). It also
retained its proteolytic activity at higher temperatures of up to 55 degrees C.
The enzyme belongs to the metalloprotease class, as its proteolytic activity was
most effectively blocked by 1,10-phenanthroline and was restored to a maximal
level by the addition of zinc metal ions. Inhibitors for the cysteine, serine,
and aspartate classes of proteases were ineffective against this enzyme. A
homology search indicates that PVHSP28 probably belongs to a new class of HSPs
which possess the metalloprotease signature sequence.
PMID- 10678928
TI - Pathogenic mechanism of mouse brain damage caused by oral infection with Shiga
toxin-producing Escherichia coli O157:H7.
AB - In a previous study, we showed that infection with Shiga toxin (Stx)-producing
Escherichia coli O157:H7 (strain Sm(r)N-9) caused neurologic symptoms in
malnourished mice with positive immunoreactions of Stx2 in brain tissues. The
present study explores the mechanism of how Stx injures the vascular endothelium
to enter the central nervous system in mice. Oral infection with strain Sm(r)N-9
elicited a tumor necrosis factor alpha (TNF-alpha) response in the blood as early
as 2 days after infection, while Stx was first detected at 3 days postinfection.
In the brain, TNF-alpha was detected at day 3, and its quantity was increased
over the next 3 days. Frozen sections of the brains from moribound mice contained
high numbers of apoptotic cells. Glycolipids recognized by an anti-Gb3 monoclonal
antibody were extracted from the brain, and purified Stx2 was able to bind to the
glycolipids. In human umbilical vascular endothelial cells (HUVEC) cultured with
fluorescein-labeled Stx2 (100 ng/ml), TNF-alpha (20 U/ml) significantly
facilitated the intracellular compartmentalization of fluorescence during 24 h of
incubation, suggesting the enhanced intracellular processing of Stx2.
Consequently, higher levels of apoptosis in HUVEC were found at 48 h. Short-term
exposure of HUVEC to Stx2 abrogated their apoptotic response to subsequent
incubation with TNF-alpha alone or TNF-alpha and Stx2. In contrast, primary
exposure of HUVEC to TNF-alpha followed by exposure to Stx2 alone or TNF-alpha
and Stx2 induced apoptosis at the same level as obtained after 48-h incubation
with these two agents. These results suggest that the rapid production of
circulating TNF-alpha after infection induces a state of competence in vascular
endothelial cells to undergo apoptosis, which would be finally achieved by
subsequent elevation of Stx in the blood. In this synergistic action, target
cells must be first exposed to TNF-alpha. Such cell injury may be a prerequisite
to brain damage after infection with Stx-producing E. coli O157:H7.
PMID- 10678929
TI - Role of group A streptococcal virulence factors in adherence to keratinocytes.
AB - To evaluate the role of putative group A streptococcal virulence factors in the
initiation of skin infections, we compared the adherence of a wild-type M49
protein skin-associated strain to that of a series of 16 isogenic mutants created
by insertional inactivation of virulence genes. None of the mutants, including
the M-protein-deficient (emm mutant) strain, displayed reduced adherence to early
passage cultured human keratinocytes, but adherence of the mutant lacking
hyaluronic acid capsule expression (has mutant) was increased 13-fold. In
contrast, elimination of capsule expression in M2-, M3-, and M18-protein has
mutants increased adherence only slightly (1.3- to 2.3-fold) compared to their
respective wild-type strains. A mutant with inactivation of both emm and has
displayed high-level adherence (34.9 +/- 4.1%) equal to that of the has mutant
strain (40.7 + 8.0%), confirming the lack of involvement of M49 protein in
attachment. Moreover, adherence of the M49-protein-deficient (emm mutant) and
wild-type strains was increased to the same level (57 and 55%, respectively)
following enzymatic digestion of their hyaluronic acid capsule. Adherence of
mutants lacking oligopeptide permease (Opp) expression was increased 3.8- to 5.5
fold, in association with decreased cell-associated hyaluronic acid capsule.
Finally, soluble CD46 failed to inhibit adherence of M49- and M52-serotype skin
strains. We conclude that (i) bacterial M protein and keratinocyte CD46 do not
mediate adherence of M49 skin-associated Streptococcus pyogenes to epidermal
keratinocytes, (ii) hyaluronic acid capsule impedes the interaction of bacterial
adhesins with keratinocyte receptors, (iii) modulation of capsule expression may
be important in the pathogenesis of skin infections, and (iv) the molecular
interactions in attachment of skin strains of S. pyogenes to keratinocytes are
unique and remain unidentified.
PMID- 10678930
TI - Borrelia burgdorferi gene expression in vivo and spirochete pathogenicity.
AB - Borrelia burgdorferi spirochetes that do not cause arthritis or carditis were
developed and used to investigate Lyme disease pathogenesis. A clonal isolate of
B. burgdorferi N40 (cN40), which induces disease in C3H/HeN (C3H) mice, was
repeatedly passaged in vitro to generate nonpathogenic spirochetes. The passage
75 isolate (N40-75) was infectious for C3H mice but did not cause arthritis or
carditis, and spirochetes were at low levels or absent in the joints or hearts,
respectively. N40-75 could, however, cause disease in severe combined
immunodeficient (SCID) mice, suggesting that the response in immunocompetent mice
prevented effective spirochete dissemination and the subsequent development of
arthritis and carditis. Administration of immune sera at 4 days after spirochete
challenge aborted N40-75, but not cN40, infection in SCID mice. A B. burgdorferi
genomic expression library was differentially probed with sera from cN40- and N40
75-infected mice, to identify genes that may not be effectively expressed by N40
75 in vivo. N40-75 was defective in the up-regulation of several genes that are
preferentially expressed during mammalian infection, including dbpAB, bba64, and
genes that map to the cp32 family of plasmids. These data suggest that adaptation
and gene expression may be required for B. burgdorferi to effectively colonize
the host, evade humoral responses, and cause disease.
PMID- 10678931
TI - Transient loss of resistance to pulmonary tuberculosis in p47(phox-/-) mice.
AB - Mycobacterium tuberculosis is an important respiratory pathogen the growth of
which is controlled primarily by cytokine-activated macrophages. One of the
principal mediators of this control is nitric oxide; however, superoxide has
recently been shown to be protective in systemic mycobacterial infections. To
determine whether superoxide is important in controlling M. tuberculosis during
primary pulmonary infection, mice lacking the cytosolic p47(phox) gene (which is
essential for effective superoxide production by the NADPH oxidase) were infected
aerogenically. The lack of superoxide during an aerosol infection with M.
tuberculosis resulted in a significant increase in bacterial growth over the
early period of infection. Once antigen-specific gamma interferon-producing
lymphocytes were detected in the draining lymph nodes, however, bacterial growth
in the lung stopped. One interesting consequence of the lack of superoxide was an
increase in neutrophilic infiltrates within the granuloma. This may be a
consequence of increased tissue damage due to more rapid bacterial growth or may
reflect a role for superoxide in controlling inflammation.
PMID- 10678932
TI - Synergistic epithelial responses to endotoxin and a naturally occurring muramyl
peptide.
AB - We have investigated the synergistic interactions of a naturally occurring
peptidoglycan fragment (muramyl peptide) and bacterial endotoxin in the induction
of inflammatory processes within respiratory epithelial cells, at the levels of
both signal transduction events and ultimate cellular metabolic effects. The
source of the muramyl peptide is Bordetella pertussis, the causative agent of the
respiratory disease pertussis. During log-phase growth, B. pertussis releases the
muramyl peptide tracheal cytotoxin (TCT), which has the structure N -
acetylglucosaminyl - 1,6 - anhydro - N - acetylmuramyl - (L) - alanyl - gamma -
(D) - glutamyl - meso - diaminopimelyl - (D) - alanine, equivalent to a monomeric
subunit of gram-negative bacterial peptidoglycan. When applied to hamster trachea
epithelial (HTE) cells, TCT and endotoxin were found to be highly synergistic in
the induction of interleukin-1alpha (IL-1alpha), type II (inducible) nitric oxide
synthase (iNOS), nitric oxide production, and inhibition of DNA synthesis.
Neither molecule alone significantly triggered these responses. The
serine/threonine protein kinase inhibitor H7 blocked induction of both IL-1alpha
and iNOS. More selective inhibitors of protein kinase C, cyclic AMP-dependent
protein kinase, and cyclic GMP-dependent protein kinase were not capable of
blocking the effects of TCT and endotoxin, suggesting that the H7-inhibited
component in this pathway is not among the commonly described kinase targets of
H7. Treatment of HTE cells with exogenous IL-1 reproduced the induction of iNOS
and DNA synthesis inhibition caused by TCT and endotoxin. H7 was not capable of
interfering with effects caused by exogenous IL-1, implying that the H7-sensitive
step in the pathway is upstream of IL-1 protein production. Similar assays with
the phorbol ester phorbol myristate acetate indicate that it could effectively
synergize with endotoxin but not with TCT, suggesting that TCT and endotoxin
induce different signal transduction events that combine synergistically. The
synergy observed with TCT and endotoxin in epithelial cells is significantly
different from their interaction with other cell types, revealing a unique
inflammatory response by epithelial cells to these natural bacterial products.
PMID- 10678933
TI - Tumor necrosis factor receptor p55-deficient mice respond to acute Yersinia
enterocolitica infection with less apoptosis and more effective host resistance.
AB - Tumor necrosis factor (TNF) has generally been regarded as a protective cytokine
in host defense against bacterial infections. In the present study, we evaluated
the role of TNF in the acute phase of infection by Yersinia enterocolitica by
using mice rendered genetically deficient in TNF receptor p55 (TNFRp55(-/-)).
Unexpectedly, TNFRp55(-/-) mice showed more effective resistance to the bacteria,
reflected in enhanced bacterial clearance and less tissue damage, than did
control C57BL/6 mice. C57BL/6 mice showed evidence of extensive apoptosis in the
spleen accompanied by a selective decrease in the CD4(+)-T-cell population of
splenocytes, whereas TNFRp55(-/-) mice were spared these changes. The splenocytes
from TNFRp55(-/-) mice also maintained a robust gamma interferon IFN-gamma
response to mitogenic stimulation, while the comparable response in C57BL/6 mice
was impaired. In addition, splenocytes harvested from infected mice demonstrated
lower production of interleukin-10 IL-10 in TNFRp55(-/-) mice than in C57BL/6
mice. These findings suggest that Yersinia can induce TNFRp55-mediated apoptosis
of splenocytes in the acute phase of the infection and that alteration of T-cell
generated cytokines can dramatically alter the early events in host defense
against this pathogen.
PMID- 10678934
TI - High immunoglobulin G2 (IgG2) and low IgG4 levels are associated with human
resistance to Plasmodium falciparum malaria.
AB - There is accumulating evidence for a role of immunoglobulin G (IgG) in protection
against malarial infection and disease. Only IgG1 and IgG3 are considered
cytophilic and protective against P. falciparum, whereas IgG2 and IgG4 were
thought to be neither and even to block protective mechanisms. However, no clear
pattern of association between isotypes and protection has so far emerged. We
analyzed the isotypic distribution of the IgG response to conserved epitopes and
P. falciparum blood-stage extract in 283 malaria-exposed individuals whose
occurrence of infection and malaria attack had been monitored for about 1 year.
Logistic regression analyses showed that, at the end of the season of
transmission, high levels of IgG2 to RESA and to MSP2 epitopes were associated
with low risk of infection. Indeed, IgG2 is able to bind FcgammaRIIA in
individuals possessing the H131 allele, and we showed that 70% of the study
subjects had this allele. Also, high specific IgG4 levels were associated with an
enhanced risk of infection and with a high risk of malaria attack. Moreover,
specific IgG2 and IgG3 levels, as well as the IgG2/IgG4 and IgG3/IgG4 ratios,
increased with the age of subjects, in parallel with the protection against
infection and disease. IgG4 likely competes with cytophilic antibodies for
antigen recognition and may therefore block cytotoxicity mediated by antibody
activated effector cells. In conclusion, these results favor a protective role of
IgG3 and IgG2, which may activate effector cells through FcgammaRIIA, and provide
evidence for a blocking role of IgG4 in malarial infection and disease.
PMID- 10678935
TI - Phospholipid synthesis by Staphylococcus aureus during (Sub)Lethal attack by
mammalian 14-kilodalton group IIA phospholipase A2.
AB - Killing of gram-positive bacteria by mammalian group IIA phospholipases A2 (PLA2)
requires the catalytic activity of the enzyme. However, nearly complete
degradation of the phospholipids can occur with little effect on bacterial
viability, suggesting that PLA2-treated bacteria can biosynthetically replace
phospholipids that are lost due to PLA2 action. In the presence of albumin,
phospholipid degradation products are quantitatively sequestered extracellularly.
In the absence of albumin, the bacteria retain and substantially reutilize the
phospholipid breakdown products and survive an otherwise lethal dose of PLA2.
PLA2-treated bacteria also continue to incorporate sodium [2-(14)C]acetate into
phospholipids, suggesting that the bacteria are attempting to repair the damaged
membranes by de novo synthesis of phospholipids. To determine whether PLA2 action
also triggers activation of bacterial lipolytic enzymes, the effects of nisin and
PLA2 on the degradation of S. aureus lipids were compared. In contrast to nisin
treatment, PLA2 treatment does not stimulate endogenous phospholipase activity in
S. aureus. These findings show that S. aureus responds to PLA2 attack by
continued phospholipid (re)synthesis by both de novo and salvage pathways. The
fate of PLA2-treated S. aureus therefore appears to depend on the relative rates
of phospholipid degradation and synthesis.
PMID- 10678936
TI - Febrile core temperature is essential for optimal host defense in bacterial
peritonitis.
AB - Fever, a nonspecific acute-phase response, has been associated with improved
survival and shortened disease duration in infections, but the mechanisms of
these beneficial responses are poorly understood. We previously reported that
increasing core temperature of bacterial endotoxin (LPS)-challenged mice to the
normal febrile range modified expression of tumor necrosis factor alpha (TNF
alpha), interleukin 1beta (IL-1beta), and IL-6, three cytokines critical to
mounting an initial defense against microbial pathogens, but survival was not
improved in the warmer animals. We speculated that our inability to show a
survival benefit of optimized cytokine expression in the warmer animals reflected
our use of LPS, a nonreplicating agonist, rather than an infection with viable
pathogens. The objective of this study was to determine if increasing murine core
temperature altered cytokine expression and improved survival in an experimental
bacterial peritonitis model. We showed that housing mice at 35.5 degrees C rather
than 23 degrees C increased core temperature from 36.5 to 37.5 degrees C to 39.2
to 39.7 degrees C, suppressed plasma TNF-alpha expression for the initial 48 h,
delayed gamma interferon expression, improved survival, and reduced the bacterial
load in mice infected with Klebsiella pneumoniae peritonitis. We showed that the
reduced bacterial load was not caused by a direct effect on bacterial
proliferation and probably reflected enhanced host defense. These data suggest
that the increase in core temperature that occurs during bacterial infections is
essential for optimal antimicrobial host defense.
PMID- 10678937
TI - Iron acquisition from Pseudomonas aeruginosa siderophores by human phagocytes: an
additional mechanism of host defense through iron sequestration?
AB - Chelation of iron to iron-binding proteins is a strategy of host defense. Some
pathogens counter this via the secretion of low-molecular-weight iron-chelating
agents (siderophores). Human phagocytes possess a high-capacity mechanism for
iron acquisition from low-molecular-weight iron chelates. Efficient acquisition
and sequestration of iron bound to bacterial siderophores by host phagocytes
could provide a secondary mechanism to limit microbial access to iron. In the
present work we report that human neutrophils, macrophages, and myeloid cell
lines can acquire iron from the two Pseudomonas aeruginosa siderophores.
Analogous to iron acquisition from other low-molecular-weight chelates, iron
acquisition from the siderophores is ATP independent, induced by multivalent
cationic metals, and unaffected by inhibitors of endocytosis and pinocytosis. In
vivo, this process could serve as an additional mechanism of host defense to
limit iron availability to invading siderophore-producing microbes.
PMID- 10678938
TI - Mutations in the S1 subunit of pertussis toxin that affect secretion.
AB - Pertussis toxin is a member of the AB(5) family of toxins and is composed of five
subunits (S1 to S5) present in a 1:1:1:2:1 ratio. Secretion is a complex process.
Each subunit has a secretion signal that mediates transport to the periplasm,
where processing and assembly occur. Secretion of the assembled 105-kDa toxin
past the outer membrane is mediated by the nine proteins encoded in the ptl
operon. Previous studies have shown that S1, the catalytically active A subunit
of pertussis toxin, is necessary for efficient secretion, suggesting that a
domain on S1 may be required for interaction with the secretion apparatus.
Previously, recombinant S1 from four different mutants (serine 54 to glycine,
serine 55 to glycine, serine 56 to glycine, and arginine 57 to lysine) was shown
to retain catalytic activity. We introduced these mutations into Bordetella
pertussis and monitored pertussis toxin production and secretion. No pertussis
toxin was detected in the serine 54-to-glycine mutant. The other S1 mutants
produced periplasmic pertussis toxin, but little pertussis toxin secretion was
observed. The arginine 57-to-lysine mutant had the most dramatic secretion
defect. It produced wild-type levels of periplasmic pertussis toxin but secreted
only 8% as much toxin as the wild-type strain. This phenotype was similar to that
observed for strains with mutations in the ptl genes, suggesting that this region
may have a role in pertussis toxin secretion.
PMID- 10678939
TI - Eimeria tenella infection induces local gamma interferon production and
intestinal lymphocyte subpopulation changes.
AB - The role of intestinal lymphocytes and gamma interferon (IFN-gamma) production in
protective immunity to Eimeria tenella infection was evaluated in two inbred
strains of chickens (SC and TK) that display different patterns of susceptibility
to coccidiosis. Oral inoculation of either strain with E. tenella led to parasite
invasion of the intestinal cecum and cecal tonsils. Greater fecal oocyst shedding
was seen in TK chickens. Flow cytometric analyses of cecal tonsil lymphocytes
demonstrated greater numbers of CD4(+) and T-cell receptor gammadelta-positive
(TCR1(+)) cells in SC chickens and elevated numbers of CD8(+) and TCR2(+) cells
in TK chickens following primary infection. IFN-gamma mRNA expression was
significantly increased in cecal tonsil and intraepithelial lymphocytes at days 6
and 8, respectively, after primary infection in SC compared to TK chickens. While
no differences were noted between cecal tonsil lymphocytes of the two strains
following secondary infection, TK chickens showed elevated IFN-gamma transcript
levels in intestinal intraepithelial lymphocytes at this time. Selective
depletion of CD4(+), but not CD8(+), cecal tonsil lymphocytes in SC chickens
resulted in a reduced IFN-gamma mRNA expression, indicating that CD4(+) cells are
the primary source of this cytokine. Collectively, these results indicate that
local lymphocyte responses and production of IFN-gamma are influenced by host
genetic factors.
PMID- 10678940
TI - Induction of necrosis in human neutrophils by Shigella flexneri requires type III
secretion, IpaB and IpaC invasins, and actin polymerization.
AB - Infection by Shigella flexneri is characterized by infiltration of neutrophils in
the intestinal mucosa and by a strong inflammatory reaction. Although neutrophils
are constitutively programmed to die by apoptosis, we show that isolated human
neutrophils undergo necrosis 2 h after infection with virulent S. flexneri strain
M90T but not with the virulence plasmid-cured strain BS176. This was demonstrated
by the release of azurophil granule proteins concomitant with the release of
lactate dehydrogenase (LDH), disruption of the plasma membrane, and absence of
DNA fragmentation. Mutants with the mxiD1 gene, coding for an essential component
of the secretion type III machinery, or the genes coding for IpaB or IpaC
invasins deleted were not cytotoxic. Neutrophil necrosis occurred independently
of the bacterial ability to leave phagosomes, and it involved actin
polymerization, as the addition of cytochalasin D after phagocytosis of Shigella
inhibited the release of LDH. In conclusion, Shigella kills neutrophils by
necrosis, a process characterized by the release of tissue-injurious granular
proteins. This probably contributes to disruption of the epithelial barrier,
leading to the dysentery observed in shigellosis and allowing Shigella to enter
its host cells.
PMID- 10678941
TI - Identification of Brucella suis genes affecting intracellular survival in an in
vitro human macrophage infection model by signature-tagged transposon
mutagenesis.
AB - Bacteria of the genus Brucella are facultative intracellular pathogens which have
developed the capacity to survive and multiply in professional and
nonprofessional phagocytes. The genetic basis of this aspect of Brucella
virulence is still poorly understood. To identify new virulence factors, we have
adapted signature-tagged transposon mutagenesis, which has been used essentially
in animal models, to an in vitro human macrophage infection model. A library of
1,152 Brucella suis 1330 tagged mini-Tn5 Km2 mutants, in 12 pools, was screened
for intracellular survival and multiplication in vitamin D(3)-differentiated THP1
cells. Eighteen mutants were identified, and their attenuation was confirmed in
THP1 macrophages and HeLa cells. For each avirulent mutant, a genomic fragment
containing the transposon was cloned. The genomic DNA sequence flanking the
transposon allowed us to assign functions to all of the inactivated genes.
Transposon integration had occurred in 14 different genes, some of which were
known virulence genes involved in intracellular survival or biosynthesis of
smooth lipopolysaccharide (the virB operon and manB), thus validating the model.
Other genes identified encoded factors involved in the regulation of gene
expression and enzymes involved in biosynthetic or metabolic pathways. Possible
roles in the virulence of Brucella for the different factors identified are
discussed.
PMID- 10678942
TI - Direct quantitative transcript analysis of the agr regulon of Staphylococcus
aureus during human infection in comparison to the expression profile in vitro.
AB - Bacteria possess a repertoire of distinct regulatory systems promoting survival
in disparate environments. Under in vitro conditions it was demonstrated for the
human pathogen Staphylococcus aureus that the expression of most virulence
factors is coordinated by the global regulator agr. To monitor bacterial gene
regulation in the host, we developed a method for direct transcript analysis from
clinical specimens. Quantification of specific transcripts was performed by
competitive reverse transcription-PCR, and results were normalized against the
constitutively expressed gene for gyrase (gyr). Using sputum from cystic fibrosis
(CF) patients infected with S. aureus we examined the transcription of the
effector molecule RNAIII of agr, of spa (protein A), generally repressed by agr,
and of hla (alpha-toxin), generally activated by agr. In the CF lung RNAIII was
expressed poorly, indicating an inactive agr in vivo. Despite the low level of
RNAIII expression, spa was detectable only in minute amounts and an irregular
transcription of hla was observed in all sputum samples. After subculturing of
patient strains agr-deficient isolates and isolates with unusual expression
profiles, i.e., not consistent with those obtained from prototypic strains, were
observed. In conclusion, the agr activity seems to be nonessential in CF, and
from the described expression pattern of spa and hla, other regulatory circuits
aside from agr are postulated in vivo.
PMID- 10678943
TI - The CD40/CD40 ligand interaction is required for resistance to toxoplasmic
encephalitis.
AB - Since the CD40/CD40 ligand (CD40L) interaction is involved in the regulation of
macrophage production of interleukin 12 (IL-12) and T-cell production of gamma
interferon (IFN-gamma), effector cell functions associated with resistance to
Toxoplasma gondii, the role of CD40L in immunity to this parasite was assessed.
Infection of C57BL/6 mice with T. gondii results in an upregulation of CD40
expression on accessory cell populations at local sites of infection as well as
in lymphoid tissues. Splenocytes from C57BL/6 mice infected with T. gondii for 5
days produced high levels of IL-12 and IFN-gamma when stimulated with toxoplasma
lysate antigen, and blocking CD40L did not significantly alter the production of
IFN-gamma or IL-12 by these cells. Similar results were observed with splenocytes
and mononuclear cells isolated from the brains of chronically infected mice.
Interestingly, although CD40L(-/-) mice infected with T. gondii produced less IL
12 than wild-type mice, they produced comparable levels of IFN-gamma but
succumbed to toxoplasmic encephalitis 4 to 5 weeks after infection. The inability
of CD40L(-/-) mice to control parasite replication in the brain correlated with
the ability of soluble CD40L, in combination with IFN-gamma, to activate
macrophages in vitro to control replication of T. gondii. Together, these results
identify an important role for the CD40/CD40L interaction in resistance to T.
gondii. However, this interaction may be more important in the control of
parasite replication in the brain rather than the generation of protective T-cell
responses during toxoplasmosis.
PMID- 10678944
TI - Mutation and recombination in the upstream homology box-flanked ospE-related
genes of the Lyme disease spirochetes result in the development of new antigenic
variants during infection.
AB - The ospE gene family of the Lyme disease spirochetes encodes a polymorphic group
of immunogenic lipoproteins. The ospE genes are one of several gene families that
are flanked by a highly conserved upstream sequence called the upstream homology
box, or UHB, element. Earlier analyses in our lab demonstrated that ospE-related
genes are characterized by defined hypervariable domains (domains 1 and 2) that
are predicted to be hydrophilic, surface exposed, and antigenic. The flanking of
hypervariable domain 1 by DNA repeats may indicate that recombination contributes
to ospE diversity and thus ultimately to antigenic variation. Using an isogeneic
clone of Borrelia burgdorferi B31G (designated B31Gc1), we demonstrate that the
ospE-related genes undergo mutation and rearrangement during infection in mice.
The mutations that develop during infection resulted in the generation of OspE
proteins with altered antigenic characteristics. The data support the
hypothesized role of OspE-related proteins in immune system evasion.
PMID- 10678945
TI - Subunit vaccination of mice against new world cutaneous leishmaniasis: comparison
of three proteins expressed in amastigotes and six adjuvants.
AB - A mixture of well-defined recombinant antigens together with an adjuvant that
preferentially stimulates specific gamma interferon (IFN-gamma)-secreting helper
type 1 CD4(+) T cells (Th1 cells) presents a rational option for a vaccine
against leishmaniasis. The potential of this approach was investigated in murine
infections with Leishmania mexicana, which are characterized by the absence of a
parasite-specific Th1 response and uncontrolled parasite proliferation. A mixture
of three antigens (glycoprotein 63, cysteine proteinases, and a membrane-bound
acid phosphatase), which are all expressed in amastigotes, the mammalian stage of
the parasite, were used for the immunization of C57BL/6 mice in combination with
six adjuvants (interleukin 12 [IL-12], Detox, 4'-monophosphoryl lipid A, QS-21,
Mycobacterium bovis BCG, and Corynebacterium parvum). All six vaccine
formulations containing the mixture of recombinant antigens were protective
against challenge infections with promastigotes, the insect stage of the
parasite, in that mice controlled and healed infections but developed transient
and, in certain cases, accentuated disease. The most effective adjuvants were IL
12 followed by Detox. Further studies using these two adjuvants showed that a
similar protective effect was observed with a mixture of the corresponding native
proteins, and mice which had controlled the infection showed a preponderance of
IFN-gamma-secreting CD4(+) T cells in the lymph nodes draining the lesion. Using
the recombinant proteins individually, it is shown that the relatively abundant
cysteine proteinases and glycoprotein 63, but not the acid phosphatase, are able
to elicit a protective response. The results are discussed in comparison to
previous studies with subunit vaccines and with respect to cell biological
aspects of antigen presentation in Leishmania-infected macrophages.
PMID- 10678946
TI - Characterization of in vitro DNA binding sites of the EUO protein of Chlamydia
psittaci.
AB - The EUO gene of chlamydia is highly expressed early in the developmental cycle,
relative to other genes, but continues to be expressed throughout the active
growth phases. The precise function of EUO protein is not known, but it binds to
DNA in vitro. In this study, we developed a selection and amplification scheme
for identifying chlamydial genomic fragments to which EUO preferentially binds in
vitro. The scheme involved mixing recombinant EUO with a Chlamydia psittaci
genomic library in a pBluescript plasmid vector in vitro, trapping EUO-bound
plasmid clones on filters, and amplifying the clones in Escherichia coli. After
nine rounds of enrichment, the EUO binding sites of the three most highly
enriched clones were identified by DNase I footprint analysis. All three clones
had multiple binding sites of various sizes with no clear distinguishing feature
other than they were AT-rich and were usually not located in putative promoter
regions. We used limited site-specific mutagenesis to characterize the strongest
binding site of the most-highly-enriched clone, which represented about 50% of
the population after nine rounds. This mutagenesis identified a core binding site
of 15 nucleotides (nt) whose sequence was used to find related sequences within
each of the strong binding sites in the other two clones. Using the frequency of
bases at specific positions within this group of sequences as a guide, we carried
out trial-and-error searching with many related sequences, eliminating those
which identified nonfootprinted sites. This process led us to the consensus 15-nt
sequence AHGAAAWVTYTWDAY, which, when allowing two mismatches, picked out all of
the strong binding sites and no nonfootprinting sites within the three enriched
clones. This sequence may be useful for predicting additional possible EUO
binding sites in the chlamydial genome.
PMID- 10678947
TI - Identification of novel serine/threonine protein phosphatases in Trypanosoma
cruzi: a potential role in control of cytokinesis and morphology.
AB - We cloned two novel Trypanosoma cruzi proteins by using degenerate
oligonucleotide primers prepared against conserved domains in mammalian
serine/threonine protein phosphatases 1, 2A, and 2B. The isolated genes encoded
proteins of 323 and 330 amino acids, respectively, that were more homologous to
the catalytic subunit of human protein phosphatase 1 than to those of human
protein phosphatase 2A or 2B. The proteins encoded by these genes have been
tentatively designated TcPP1alpha and TcPP1beta. Northern blot analysis revealed
the presence of a major 2.3-kb mRNA transcript hybridizing to each gene in both
the epimastigote and metacyclic trypomastigote developmental stages. Southern
blot analysis suggests that each protein phosphatase 1 gene is present as a
single copy in the T. cruzi genome. The complete coding region for TcPP1beta was
expressed in Escherichia coli by using a vector, pTACTAC, with the trp-lac hybrid
promoter. The recombinant protein from the TcPP1beta construct displayed
phosphatase activity toward phosphorylase a, and this activity was preferentially
inhibited by calyculin A (50% inhibitory concentration [IC(50)], approximately 2
nM) over okadaic acid (IC(50), approximately 100 nM). Calyculin A, but not
okadaic acid, had profound effects on the in vitro replication and morphology of
T. cruzi epimastigotes. Low concentrations of calyculin A (1 to 10 nM) caused
growth arrest. Electron microscopic studies of the calyculin A-treated
epimastigotes revealed that the organisms underwent duplication of organelles,
including the flagellum, kinetoplast, and nucleus, but were incapable of
completing cell division. At concentrations higher than 10 nM, or upon prolonged
incubation at lower concentrations, the epimastigotes lost their characteristic
elongated spindle shape and had a more rounded morphology. Okadaic acid at
concentrations up to 1 microM did not result in growth arrest or morphological
alterations to T. cruzi epimastigotes. Calyculin A, but not okadaic acid, was
also a potent inhibitor of the dephosphorylation of (32)P-labeled phosphorylase a
by T. cruzi epimastigotes and metacyclic trypomastigote extracts. These inhibitor
studies suggest that in T. cruzi, type 1 protein phosphatases are important for
the completion of cell division and for the maintenance of cell shape.
PMID- 10678948
TI - Coinvasion of dentinal tubules by Porphyromonas gingivalis and Streptococcus
gordonii depends upon binding specificity of streptococcal antigen I/II adhesin.
AB - Cell wall-anchored polypeptides of the antigen I/II family are produced by many
species of oral streptococci. These proteins mediate adhesion of streptococci to
salivary glycoproteins and to other oral microorganisms and promote binding of
cells to collagen type I and invasion of dentinal tubules. Since infections of
the root canal system have a mixed anaerobic bacterial etiology, we investigated
the hypothesis that coadhesion of anaerobic bacteria with streptococci may
facilitate invasive endodontic disease. Porphyromonas gingivalis ATCC 33277 cells
were able to invade dentinal tubules when cocultured with Streptococcus gordonii
DL1 (Challis) but not when cocultured with Streptococcus mutans NG8. An isogenic
noninvasive mutant of S. gordonii, with production of SspA and SspB (antigen I/II
family) polypeptides abrogated, was deficient in binding to collagen and had a
40% reduced ability to support adhesion of P. gingivalis. Heterologous expression
of the S. mutans SpaP (antigen I/II) protein in this mutant restored collagen
binding and tubule invasion but not adhesion to P. gingivalis or the ability to
promote P. gingivalis coinvasion of dentin. An isogenic afimbrial mutant of P.
gingivalis had 50% reduced binding to S. gordonii cells but was unaffected in the
ability to coinvade dentinal tubules with S. gordonii wild-type cells. Expression
of the S. gordonii SspA or SspB polypeptide on the surface of Lactococcus lactis
cells endowed these bacteria with the abilities to bind P. gingivalis, penetrate
dentinal tubules, and promote P. gingivalis coinvasion of dentin. The results
demonstrate that collagen-binding and P. gingivalis-binding properties of antigen
I/II polypeptides are discrete functions. Specificity of antigen I/II polypeptide
recognition accounts for the ability of P. gingivalis to coinvade dentinal
tubules with S. gordonii but not with S. mutans. This provides evidence that the
specificity of interbacterial coadhesion may influence directly the etiology of
pulpal and periapical diseases.
PMID- 10678949
TI - Assessing the binding of four Plasmodium falciparum T helper cell epitopes to HLA
DQ and induction of T-cell responses in HLA-DQ transgenic mice.
AB - A subunit vaccine for Plasmodium falciparum malaria will need to contain well
defined T helper cell epitopes that induce protective immune responses to the
parasite. One major barrier to the use of subunit vaccines is the requirement for
T helper cell epitopes to be presented by the HLA class II molecules that are
present in the population being vaccinated. Since the majority of malaria studies
have focused on HLA-DR, little information on the role of HLA-DQ in the binding
and immune response to malarial epitopes is available. This study used an in
vitro peptide-binding assay to predict the extent of HLA-DQ binding of four
conserved T helper cell epitopes identified from asexual-stage malaria vaccine
candidate antigens. Epstein-Barr virus (EBV)-transformed human B-cell lines
expressing 14 different DQ molecules (DQ2.1, -2.2, -4.1, -4.2, -5.1 to -5.3,
6.1, -6.2, -6.4, -7.1, -7.3, -8, and -9) representing all broad serological
specificities, including common DQ molecules present in populations in areas
where malaria is endemic, were used in the binding assay. Moreover, an HLA-DQ
transgenic mouse model was employed to evaluate the correlation between the in
vitro DQ binding of the peptides and the generation of in vivo immune responses
following peptide immunization. This study identified two broad DQ-binding
peptides, ABRA#14 and SERA#9. ABRA#14 also induced T-cell proliferation and Th1
associated cytokine production in DQ8(+) transgenic mice. The combination of
peptide binding to EBV-transformed cell lines and DQ transgenic mice provides a
method for identifying additional T-cell epitopes for inclusion in a vaccine.
PMID- 10678950
TI - Genetic relationships between clinical isolates of Streptococcus pneumoniae,
Streptococcus oralis, and Streptococcus mitis: characterization of "Atypical"
pneumococci and organisms allied to S. mitis harboring S. pneumoniae virulence
factor-encoding genes.
AB - The oral streptococcal group (mitis phylogenetic group) currently consists of
nine recognized species, although the group has been traditionally difficult to
classify, with frequent changes in nomenclature over the years. The pneumococcus
(Streptococcus pneumoniae), an important human pathogen, is traditionally
distinguished from the most closely related oral streptococcal species
Streptococcus mitis and Streptococcus oralis on the basis of three
differentiating characteristics: optochin susceptibility, bile solubility, and
agglutination with antipneumococcal polysaccharide capsule antibodies. However,
there are many reports in the literature of pneumococci lacking one or more of
these defining characteristics. Sometimes called "atypical" pneumococci, these
isolates can be the source of considerable confusion in the clinical laboratory.
Little is known to date about the genetic relationships of such organisms with
classical S. pneumoniae isolates. Here we describe these relationships based on
sequence analysis of housekeeping genes in comparison with previously
characterized isolates of S. pneumoniae, S. mitis, and S. oralis. While most
pneumococci were found to represent a closely related group these studies
identified a subgroup of atypical pneumococcal isolates (bile insoluble and/or
"acapsular") distinct from, though most closely related to, the "typical"
pneumococcal isolates. However, a large proportion of isolates, found to be
atypical on the basis of capsule reaction alone, did group with typical
pneumococci, suggesting that they have either lost capsule production or
represent as-yet-unrecognized capsular types. In contrast to typical S.
pneumoniae, isolates phenotypically identified as S. mitis and S. oralis, which
included isolates previously characterized in taxonomic studies, were genetically
diverse. While most of the S. oralis isolates did fall into a well-separated
group, S. mitis isolates did not cluster into a well-separated group. During the
course of these studies we also identified a number of potentially important
pathogenic isolates, which were frequently associated with respiratory disease,
that phenotypically and genetically are most closely related to S. mitis but
which harbor genes encoding the virulence determinants pneumolysin and autolysin
classically associated with S. pneumoniae.
PMID- 10678951
TI - A regulatory role for interleukin 4 in differential inflammatory responses in the
lung following infection of mice primed with Th1- or Th2-inducing pertussis
vaccines.
AB - Protection against infectious pathogens at mucosal surfaces is dependent on local
antibody responses, production of inflammatory mediators, and recruitment of
immune effector cells to the site of infection. Since Th1 and Th2 cells produce
cytokines with pro- and anti-inflammatory activities, immunization with vaccines
that induce these T-cell subtypes may regulate the subsequent inflammatory
response to infection. We have demonstrated that immunization of mice with
pertussis whole-cell or acellular vaccines (Pw or Pa) selectively induces Th1 and
Th2 cells, respectively. In this study we have used a murine respiratory
infection model to demonstrate that priming with a Th1- or Th2-inducing pertussis
vaccine can influence the local inflammatory response and immune effector cells
in the lung following aerosol challenge with Bordetella pertussis. Analysis of
bronchoalveolar lavage (BAL) fluid taken during the course of B. pertussis
infection of naive mice or mice immunized with Pw revealed an early influx of
neutrophils and local production of interleukin 1beta (IL-1beta) in the lungs. In
contrast, neutrophil infiltration and IL-1beta production were not observed
following challenge of mice immunized with the Th2-inducing Pa. Conversely,
during infection local production of IL-6 and IL-1ra was significantly greater in
mice immunized with Pa than in those immunized with Pw. Studies of knockout mice
revealed neutrophil and lymphocyte infiltration in the lungs following B.
pertussis infection of IL-4-defective (IL-4(-/-)) mice but not in wild-type mice
immunized with Pa. Furthermore, the levels of IL-1beta, IL-6, and IL-1ra in Pa
immunized IL-4(-/-) mice were comparable to those in mice immunized with Pw.
These results demonstrate distinct influences of Th1- and Th2-inducing vaccines
on the protective inflammatory responses in the lungs following challenge with B.
pertussis and implicate IL-4 as an important regulator of inflammatory-cell
recruitment.
PMID- 10678952
TI - Role of decay-accelerating factor domains and anchorage in internalization of Dr
fimbriated Escherichia coli.
AB - Dr-fimbriated Escherichia coli capable of invading epithelial cells recognizes
human decay-accelerating factor (DAF) as its cellular receptor. The role of
extracellular domains and the glycosylphosphatidylinositol anchor of DAF in the
process of internalization of Dr(+) E. coli was characterized in a cell-cell
interaction model. Binding of Dr(+) E. coli to the short consensus repeat 3
domain of DAF expressed by Chinese hamster ovary cells was critical for
internalization to occur. Deletion of short consensus repeat 3 domain or
replacement of Ser(165) by Leu in this domain, or the use of a monoclonal
antibody to this region abolished internalization. Replacing the
glycosylphosphatidylinositol anchor of DAF with the transmembrane anchor of
membrane cofactor protein or HLA-B44 resulted in abolition or reduction of
internalization respectively. Cells expressing glycosylphosphatidylinositol
anchored DAF but not the transmembrane-anchored DAF internalized Dr(+) E. coli
through a glycolipid pathway, since the former cells were more sensitive to
inhibition by methyl-beta-cyclodextrin, a sterol-chelating agent. Electron
microscopic studies revealed that the intracellular vacuoles containing the
internalized Dr(+) E. coli were morphologically distinct between the anchor
variants of DAF. The cells expressing glycosylphosphatidylinositol-anchored DAF
contained a single bacterium in tight-fitting vacuoles, while the cells
expressing transmembrane-anchored DAF contained multiple (two or three) bacteria
in spacious phagosomes. This finding suggests that distinct postendocytic events
operate in the cells expressing anchor variants of DAF. We provide direct
evidence for the DAF-mediated internalization of Dr(+) E. coli and demonstrate
the significance of the glycosylphosphatidylinositol anchor, which determines the
ability and efficiency of the internalization event.
PMID- 10678953
TI - Iha: a novel Escherichia coli O157:H7 adherence-conferring molecule encoded on a
recently acquired chromosomal island of conserved structure.
AB - The mechanisms used by Shiga toxin (Stx)-producing Escherichia coli to adhere to
epithelial cells are incompletely understood. Two cosmids from an E. coli O157:H7
DNA library contain an adherence-conferring chromosomal gene encoding a protein
similar to iron-regulated gene A (IrgA) of Vibrio cholerae (M. B. Goldberg, S. A.
Boyko, J. R. Butterton, J. A. Stoebner, S. M. Payne, and S. B. Calderwood, Mol.
Microbiol. 6:2407-2418, 1992). We have termed the product of this gene the IrgA
homologue adhesin (Iha), which is encoded by iha. Iha is 67 kDa in E. coli
O157:H7 and 78 kDa in laboratory E. coli and is structurally unlike other known
adhesins. DNA adjacent to iha contains tellurite resistance loci and is conserved
in structure in distantly related pathogenic E. coli, but it is absent from
nontoxigenic E. coli O55:H7, sorbitol-fermenting Stx-producing E. coli O157:H-,
and laboratory E. coli. We have termed this region the tellurite resistance- and
adherence-conferring island. We conclude that Iha is a novel bacterial adherence
conferring protein and is contained within an E. coli chromosomal island of
conserved structure. Pathogenic E. coli O157:H7 has only recently acquired this
island.
PMID- 10678954
TI - Interferon consensus sequence binding protein confers resistance against Yersinia
enterocolitica.
AB - Interferon consensus sequence binding protein (ICSBP)-deficient mice display
enhanced susceptibility to intracellular pathogens. At least two distinct
immunoregulatory defects are responsible for this phenotype. First, diminished
production of reactive oxygen intermediates in macrophages results in impaired
intracellular killing of microorganisms. Second, defective early interleukin-12
(IL-12) production upon microbial challenge leads to a failure in gamma
interferon (IFN-gamma) induction and subsequently in T helper 1 immune responses.
Here, we investigated the role of ICSBP in resistance against the extracellular
bacterium Yersinia enterocolitica. ICSBP(-/-) mice failed to produce IL-12 and
IFN-gamma, but also IL-4, after Yersinia challenge. In addition, granuloma
formation was highly disturbed in infected ICSBP(-/-) mice, leading to multiple
necrotic abscesses in affected organs. Consequently, ICSBP(-/-) mice rapidly
succumbed to acute Yersinia infection. In vitro treatment of spleen cells from
ICSBP(-/-) mice with recombinant IL-12 (rIL-12) or rIL-18 in combination with a
second stimulus resulted in IFN-gamma induction. In experimental therapy of
infected ICSBP(-/-) mice, we observed that administration of rIL-12 induced IFN
gamma production which was associated with improved resistance to Yersinia. In
contrast, treatment with rIL-18 failed to enhance endogenous IFN-gamma production
but nevertheless reduced bacterial burden in ICSBP(-/-) mice. Although cytokine
therapy with rIL-12 or rIL-18 ameliorated the course of Yersinia infection in
ICSBP(-/-) mice, both cytokines failed to completely restore impaired immunity.
Taken together, the results indicate that the transcription factor ICSBP is
essential for efficient host immune defense against Yersinia. These results are
important for understanding the complex host immune responses in bacterial
infections.
PMID- 10678955
TI - Vaccine efficacy of recombinant Plasmodium falciparum merozoite surface protein 1
in malaria-naive, -exposed, and/or -rechallenged Aotus vociferans monkeys.
AB - Protection against a lethal challenge infection of Plasmodium falciparum was
elicited in malaria-naive Aotus vociferans monkeys by vaccination with the C
terminus 19-kDa protein of the major merozoite surface protein (MSP-1(19)) fused
to tetanus toxoid universal T-cell epitopes P30 and P2. Three of four monkeys
were protected against a 10(4)-parasite challenge. Four monkeys were challenged
with 10(5) parasites; one self-cured the infection, two were protected against
high parasitemia (<2%) but were treated for severe anemia (hematocrit of <25%),
and the fourth was not protected. In this model system, anemia appears to be a
manifestation of incomplete protection (prolonged low-level parasitemia). Enzyme
linked immunosorbent assay (ELISA) antibody titers correlated with protection.
Antibodies from some protected monkeys inhibited secondary processing of MSP
1(42) to MSP-1(33) and MSP-1(19). To mimic the repeated reinfections seen in
regions where malaria is endemic, a second malaria parasite challenge was
administered 4 months later. All P30P2MSP-1(19)-vaccinated monkeys were
protected; thus, a single challenge infection may underestimate vaccine efficacy.
ELISA antibody titers correlated with protection against a second infection but
had decreased compared to the first challenge. As most target populations for
asexual blood-stage malaria vaccines will have been exposed to malaria parasites,
a malaria parasite-exposed monkey was vaccinated with P30P2MSP-1(19). This monkey
was completely protected, while a malaria parasite-naive P30P2MSP-1(19)
vaccinated monkey self-cured a low-grade parasitemia. Prior malaria parasite
infection primed the production of anti-native MSP-1(19) antibodies, which were
boosted by vaccination with recombinant P30P2MSP-1(19). Preliminary data suggest
that immunogenicity studies of vaccines designed for malaria parasite-exposed
populations should also be conducted in malaria parasite-exposed subjects.
PMID- 10678956
TI - Activated T cells induce macrophages to produce NO and control Leishmania major
in the absence of tumor necrosis factor receptor p55.
AB - The ability to activate macrophages in vitro for nitric oxide production and
killing of Leishmania major parasites is dependent on tumor necrosis factor,
although L. major-infected mice lacking the TNF receptor p55 (TNFRp55(-/-) mice)
or both the TNFRp55 and TNFRp75 (TNFRp55p75(-/-) mice) are able to produce NO in
vivo and eliminate the parasites. Here we report that activated T cells
cocultured with macrophages results in TNFR-independent activation sufficient to
control parasites and that both CD40/CD40L and LFA-1 contribute to T-cell
mediated macrophage activation. Thus, anti-CD3-stimulated T cells activated TNFR
deficient macrophages, while T cells from CD40L(-/-) mice were partially
defective in triggering NO production by TNFRp55p75(-/-) macrophages. Moreover,
in the presence of gamma interferon, anti-CD40 monoclonal antibody (MAb)
activated TNFR-deficient macrophages. Finally, MAb blockade of LFA-1 completely
inhibited macrophage NO production. Our data indicate that T cells can activate
macrophages in the absence of TNF, thus providing a mechanism for how TNFR
deficient mice can control intracellular pathogens.
PMID- 10678957
TI - Immunogenicity and tolerance of a 7-valent pneumococcal conjugate vaccine in
nonresponders to the 23-valent pneumococcal vaccine.
AB - There is still a lack of effective vaccination strategies for patients with a
deficient antibody response to bacterial polysaccharide antigens. In an open
trial, we evaluated the immunogenicity and tolerance of a new 7-valent
pneumococcal conjugate vaccine in 22 infection-prone nonresponders to
pneumococcal polysaccharide vaccine and 21 controls. In the patient group,
nonresponsiveness was confirmed by repeated vaccination with a 23-valent
pneumococcal polysaccharide vaccine. The study protocol provided two doses of the
pneumococcal conjugate vaccine, given 4 to 6 weeks apart, for both groups. The
antibody response was determined before each vaccination and on follow-up by an
enzyme-linked immunosorbent assay and compared to the response in a functional
opsonophagocytosis assay. Patients showed a significantly lower postvaccination
immune response for all serotypes than did controls. The postvaccination response
was serotype dependent. A median titer of >1 microgram/ml in patients was
recorded only for serotypes 4, 9V, 14, and 19F, which are known to be more
immunogenic than serotypes 6B, 18C, and 23F. In the patient group, 70% responded
to serotype 19F (Pnc 19F), 65% responded to Pnc 14 and 4, 60% responded to Pnc
9V, 55% responded to Pnc 18C, 50% responded to Pnc 23F, and 25% responded to Pnc
6B. In the control group >95% of individuals showed a titer of >1 microgram/ml to
every serotype. The vaccine was tolerated well, and no major side effects have
been reported. The new pneumococcal conjugate vaccine is clearly more immunogenic
in previous nonresponders than is the 23-valent pneumococcal vaccine.
Immunization with a pneumococcal conjugate vaccine should be considered as a
strategy to protect high-risk patients.
PMID- 10678958
TI - Characterization of Porphyromonas gingivalis-induced degradation of epithelial
cell junctional complexes.
AB - Porphyromonas gingivalis is considered among the etiological agents of human
adult periodontitis. Although in vitro studies have shown that P. gingivalis has
the ability to invade epithelial cell lines, its effect on the epithelial barrier
junctions is not known. Immunofluorescence analysis of human gingival epithelial
cells confirmed the presence of tight-junction (occludin), adherens junction (E
cadherin), and cell-extracellular matrix junction (beta1-integrin) transmembrane
proteins. These transmembrane proteins are expressed in Madin-Darby canine kidney
(MDCK) cells. In addition, MDCK cells polarize and therefore serve as a useful in
vitro model for studies on the epithelial cell barrier. Using the MDCK cell
system, we examined the effect of P. gingivalis on epithelial barrier function.
Exposure of the basolateral surfaces of MDCK cells to P. gingivalis (>10(9)
bacteria/ml) resulted in a decrease in transepithelial resistance.
Immunofluorescence microscopy demonstrated decreases in the amounts of
immunoreactive occludin, E-cadherin, and beta1-integrin at specific times which
were related to a disruption of cell-cell junctions in MDCK cells exposed to
basolateral P. gingivalis. Disruption of cell-cell junctions was also observed
upon apical exposure to bacteria; however, the effects took longer than those
seen upon basolateral exposure. Cell viability was not affected by either
basolateral or apical exposure to P. gingivalis. Western blot analysis
demonstrated hydrolysis of occludin, E-cadherin, and beta1-integrin in lysates
derived from MDCK cells exposed to P. gingivalis. Immunoprecipitated occludin and
E-cadherin molecules from MDCK cell lysates were also degraded by P. gingivalis,
suggesting a bacterial protease(s) capable of cleaving these epithelial junction
transmembrane proteins. Collectively, these data suggest that P. gingivalis is
able to invade the deeper structures of connective tissues via a paracellular
pathway by degrading epithelial cell-cell junction complexes, thus allowing the
spread of the bacterium. These results also indicate the importance of a critical
threshold concentration of P. gingivalis to initiate epithelial barrier
destruction.
PMID- 10678959
TI - CpG oligodeoxynucleotides act as adjuvants for pneumococcal polysaccharide
protein conjugate vaccines and enhance antipolysaccharide immunoglobulin G2a
(IgG2a) and IgG3 antibodies.
AB - Pneumococcal polysaccharide-protein conjugate vaccines elicit antipolysaccharide
antibodies, but multiple doses are required to achieve protective antibody levels
in children. In addition, the immunogenicity of experimental multivalent
pneumococcal conjugate vaccines varies with different polysaccharide serotypes.
One strategy to improve these vaccines is to incorporate an adjuvant to enhance
their immunogenicity. Synthetic oligodeoxynucleotides containing unmethylated CpG
motifs (CpG ODN) are adjuvants that promote T-cell and T-dependent antibody
responses to protein antigens, but it has been unclear whether CpG ODN can
enhance polysaccharide-specific antibody responses. The present studies
demonstrate significant adjuvant activity of CpG ODN for antibody responses
against Streptococcus pneumoniae polysaccharide types 19F and 6B induced by
conjugates of 19F and 6B with the protein carrier CRM(197). BALB/c ByJ mice were
injected with 19F-CRM(197) or 6B-CRM(197) with or without CpG ODN, and sera were
tested for anti-19F or anti-6B antibodies by enzyme-linked immunosorbent assay.
The polysaccharide-specific antibody response to 19F-CRM(197) alone was
predominantly of the immunoglobulin G1 (IgG1) and IgM isotypes, but addition of
CpG ODN markedly increased geometric mean titers of total anti-19F antibody (23
fold), anti-19F IgG2a (26-fold), and anti-19F IgG3 (>246-fold). The
polysaccharide-specific antibody response to 6B-CRM(197) alone consisted only of
IgM, but addition of CpG ODN induced high titers of anti-6B IgG1 (>78-fold
increase), anti-6B IgG2a (>54-fold increase), and anti-6B IgG3 (>3,162-fold
increase). CpG ODN also increased anti-CRM(197) IgG2a and IgG3. Adjuvant effects
were not observed with control non-CpG ODN. Thus, CpG ODN significantly enhance
antipolysaccharide IgG responses (especially IgG2a and IgG3) induced by these
glycoconjugate vaccines.
PMID- 10678960
TI - Chlamydial development is adversely affected by minor changes in amino acid
supply, blood plasma amino acid levels, and glucose deprivation.
AB - This study has demonstrated the extreme sensitivity of Chlamydia trachomatis
growing in McCoy cells to small changes in external amino acid supply. In the
absence of cycloheximide, a decrease in the amino acid concentration of medium to
75% of control values was sufficient to induce the growth of enlarged chlamydial
forms of reduced infectivity. Morphology became more distorted and the yield of
infectious particles from inclusions declined as medium amino acid levels were
further reduced. These events correlated with a general decline in intracellular
amino acids, as measured by high-performance liquid chromatography, suggesting
that chlamydiae require a minimum concentration of each amino acid for normal
development. Cycloheximide enhanced the production of normal organisms and
increased infectivity yield in media, suggesting that the drug increased the
available pool of amino acids. This was supported by intracellular amino acid
analyses. Aberrant forms with reduced infectivity were also induced during supply
of infected cell cultures with medium containing blood plasma amino acid
concentrations, supporting the proposal that nutrient levels in vivo could
promote abnormal chlamydial development. Markedly abnormal forms were also
observed during glucose deprivation, providing further evidence that aberrant
development is a general stress-related response.
PMID- 10678961
TI - Use of defined mutants to assess the role of the Campylobacter rectus S-layer in
bacterium-epithelial cell interactions.
AB - Campylobacter rectus is a periodontal pathogen with a 150-kDa protein on its cell
surface. This protein forms a paracrystalline lattice, called the S-layer,
surrounding the outer membrane of this gram-negative bacterium. To initiate a
genetic analysis of the possible role of the S-layer in the initial interaction
of C. rectus with host epithelial cells, C. rectus strains lacking the S-layer
protein gene (crsA) were constructed by allelic exchange mutagenesis.
Surprisingly, the lack of the S-layer had only a minor effect on the interaction
of C. rectus with HEp-2 epithelial cells; CrsA(+) cells were 30 to 50% more
adherent than were CrsA(-) bacteria. Since the host cell expression of cytokines
appears to play an important role in the pathogenesis of periodontal diseases,
the effect of the S-layer on the epithelial cell cytokine response was also
examined by quantitative reverse transcriptase PCR and enzyme-linked
immunosorbent assay. Although there were no changes in the mRNA levels for the
anti-inflammatory cytokines interleukin-1 receptor agonist (IL-1ra), IL-13, and
transforming growth factor beta, the expression and secretion of the
proinflammatory cytokines IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha)
were significantly induced by both wild-type C. rectus and CrsA(-) bacteria.
Interestingly, the kinetics of cytokine induction differed for the CrsA(+) and
CrsA(-) bacteria. At early time points, the HEp-2 cells challenged with CrsA(-)
bacteria produced higher levels of IL-6, IL-8, and TNF-alpha mRNA and protein
than did cells challenged with CrsA(+) bacteria. We conclude that C. rectus may
help initiate periodontitis by increasing the expression of proinflammatory
cytokines and that the S-layer may temper this response to facilitate the
survival of C. rectus at the site of infection.
PMID- 10678962
TI - Identification of two distinct types of flagellar cap proteins, FliD, in
Pseudomonas aeruginosa.
AB - Binding of Pseudomonas aeruginosa strain PAK to mucin has been shown to be
mediated by the flagellar cap protein, product of the fliD gene. Since the
flagellar cap is very likely an exposed structure, the FliD polypeptide should be
recognized by the host immune system, analogous to the recognition of dominant
epitopes located in the exposed parts of the flagellin polypeptide within the
assembled flagellum. In P. aeruginosa, a number of distinct flagellin variants
are made, and these variable sequences presumably allow the newly infected P.
aeruginosa to escape recognition by the antibody induced during a previous
infection. Since similar mechanisms may direct the selection of FliD variants, we
examined the extent of sequence heterogeneity among various FliD sequences among
a selected group of P. aeruginosa. The results of PCR and nucleotide sequencing
of the fliD region of eight different P. aeruginosa strains (laboratory strains
PAK, PAO1, and PA103; clinical strains 1244, CS2, and CS32; cystic fibrosis
strains CS29 and MDR) suggested that there were two distinct types of FliD in P.
aeruginosa, which we named A type and B type. The results of Western blotting
using the polyclonal antibodies raised against the purified FliD of A type (PAK)
or B type (PAO1) further confirmed the existence of two distinct antigenic types
of FliD proteins, with no cross-reactivity between the two serotypes. Further
Western immunoblot analysis of the same strains using polyclonal FliC antibody
showed that the strains with A-type FliD possessed a-type FliC and those with B
type FliD had b-type FliC. Similar Western blot analyses of 50 more P. aeruginosa
strains obtained from varied sources revealed that all strains contained either A
type or B-type FliD, suggesting the existence of only two types of FliD in P.
aeruginosa and indicating that fliC and fliD were coinherited. This limited
diversity of FliC and FliD serotypes seems to be a unique feature of flagellar
proteins. A chromosomal mutant having an insertion in the fliD gene of P.
aeruginosa PAO1 was constructed. The motility defect of this mutant and a
previously constructed PAK fliD mutant was better complemented with the fliD gene
of the homologous types.
PMID- 10678963
TI - Influence of the bcg locus on natural resistance to primary infection with the
facultative intracellular bacterium Francisella tularensis in mice.
AB - The implication of the Bcg locus in the control of natural resistance to
infection with a live vaccine strain (LVS) of the intracellular pathogen
Francisella tularensis was studied. Analysis of phenotypic expression of natural
resistance and susceptibility was performed using mouse strains congenic at the
Bcg locus. Comparison of the kinetics of bacterial colonization of spleen showed
that B10.A.Bcg(r) mice were extremely susceptible during early phases of primary
sublethal infection, while their congenic C57BL/10N [Bcg(s)] counterparts could
be classified as resistant to F. tularensis LVS infection according to the 2-log
lower bacterial CFU within the tissue as long as 5 days after infection.
Different phenotypes of Bcg congenic mice were associated with differential
expression of the cytokines tumor necrosis factor alpha, interleukin-10, and
gamma interferon and production of reactive oxygen intermediates. These results
strongly suggest that the Bcg locus, which is close or identical to the Nramp1
gene, controls natural resistance to infection by F. tularensis and that its
effect is the opposite of that observed for other Bcg-controlled pathogens.
PMID- 10678964
TI - Cellular changes and apoptosis in the spleens and peripheral blood of mice
infected with blood-stage Plasmodium chabaudi chabaudi AS.
AB - Infection with blood-stage Plasmodium chabaudi chabaudi AS results in
splenomegaly, peripheral leukocytosis, and a major activation of the immune
system. The frequencies and absolute numbers of T-cell, B-cell, and macrophage
populations in spleen and peripheral blood from P. chabaudi-infected BALB/c mice
were compared and found to be significantly altered during acute infection. The
kinetics of the redistribution of the different cell types in spleen and
peripheral blood were different, with T and B cells appearing in the blood when
their frequencies and absolute numbers in the spleen were low. The frequency and
absolute number of apoptotic cells in the spleen were increased during acute P.
chabaudi infection and involved both T cells, B cells, and macrophages. Both Fas
and Fas-ligand expression were increased in the spleen. Taken together, our data
provide new information on the complex cellular interactions that take place in
the immune system during blood-stage malaria infection in a mouse model.
PMID- 10678965
TI - The virulence regulatory protein ToxR mediates enhanced bile resistance in Vibrio
cholerae and other pathogenic Vibrio species.
AB - The transmembrane regulatory protein ToxR is required for expression of virulence
factors in the human diarrheal pathogen Vibrio cholerae, including cholera toxin
(CT) and the toxin coregulated pilus (TCP). ToxR is necessary for transcription
of the gene encoding a second regulatory protein, ToxT, which is the direct
transcriptional activator of CT and TCP genes. However, ToxR, independent of
ToxT, directly activates and represses transcription of the outer membrane porins
OmpU and OmpT, respectively. The genes encoding TCP and CT (and including ToxT)
lie on horizontally acquired genetic elements, while the toxR, ompU, and ompT
genes are apparently in the ancestral Vibrio chromosome. The contribution of ToxR
dependent modulation of outer membrane porins to cholera pathogenesis has
remained unknown. We demonstrate that ToxR mediates enhanced bile resistance in a
ToxT-independent manner. In both classical and El Tor biotypes of V. cholerae, a
toxR mutant strain has a reduced minimum bactericidal concentration (MBC) of
bile, the bile component deoxycholate (DC), and the anionic detergent sodium
dodecyl sulfate (SDS) compared to both wild-type and toxT mutant strains.
Classical and El Tor toxR mutant strains also exhibit reduced growth rates at
subinhibitory concentrations of DC and SDS. Growth of either V. cholerae biotype
in subinhibitory concentrations of bile or DC induces increased ToxR-dependent
production of a major 38-kDa outer membrane protein, which was confirmed to be
OmpU by Western blot. Measurement of transcription of a ompUp-lacZ fusion in both
biotypes reveals stimulation (about two- to threefold) of ToxR-dependent ompU
transcription by the presence of bile or DC, suggesting that ToxR may respond to
the presence of bile. The toxR mutant strains of three additional human
intestinal pathogenic Vibrio species, V. mimicus, V. fluvialis, and V.
parahaemolyticus, display lower MBCs of bile, DC, and SDS and have altered outer
membrane protein profiles compared to the parental wild-type strains. Our results
demonstrate a conserved role for ToxR in the modulation of outer membrane
proteins and bile resistance of pathogenic Vibrio species and suggest that these
ToxR-dependent outer membrane proteins may mediate enhanced resistance to bile.
We speculate that ToxR-mediated bile resistance was an early step in the
evolution of V. cholerae as an intestinal pathogen.
PMID- 10678966
TI - Listeria monocytogenes as a short-lived delivery system for the induction of type
1 cell-mediated immunity against the p36/LACK antigen of Leishmania major.
AB - Listeria monocytogenes has been used as an experimental live vector for the
induction of CD8-mediated immune responses in various viral and tumoral
experimental models. Susceptibility of BALB/c mice to Leishmania major infection
has been correlated to the preferential development of Th2 CD4 T cells through an
early production of interleukin 4 (IL-4) by a restricted population of CD4 T
cells which react to a single parasite antigen, LACK (stands for Leishmania
homologue of receptors for activated C kinase). Experimental vaccination with
LACK can redirect the differentiation of CD4(+) T cells towards the Th1 pathway
if LACK is coadministrated with IL-12. As IL-12 is known to be induced by L.
monocytogenes, we have tested the ability of a recombinant attenuated actA mutant
L. monocytogenes strain expressing LACK to induce the development of LACK
specific Th1 cells in both B10.D2 and BALB/c mice, which are resistant and
susceptible to L. major, respectively. After a single injection of LACK
expressing L. monocytogenes, IL-12/p40 transcripts showed a rapid burst, and
peaks of gamma interferon (IFN-gamma)-secreting LACK-specific Th1 cells were
detected around day 5 in the spleens and livers of mice of both strains. These
primed IFN-gamma-secreting LACK-reactive T cells were not detected ex vivo after
day 7 of immunization but could be recruited and detected 15 days later in the
draining lymph node after an L. major footpad challenge. Although immunization of
BALB/c mice with LACK-expressing L. monocytogenes did not change the course of
the infection with L. major, immunized B10.D2 mice exhibited significantly
smaller lesions than nonimmunized controls. Thus, our results demonstrate that,
in addition of its recognized use for the induction of effector CD8 T cells, L.
monocytogenes can also be used as a live recombinant vector to favor the
development of potentially protective IFN-gamma-secreting Th1 CD4 T lymphocytes.
PMID- 10678967
TI - Infectious CTXPhi and the vibrio pathogenicity island prophage in Vibrio mimicus:
evidence for recent horizontal transfer between V. mimicus and V. cholerae.
AB - Vibrio mimicus differs from Vibrio cholerae in a number of genotypic and
phenotypic traits but like V. cholerae can give rise to diarrheal disease. We
examined clinical isolates of V. mimicus for the presence of CTXPhi, the
lysogenic filamentous bacteriophage that carries the cholera toxin genes in
epidemic V. cholerae strains. Four V. mimicus isolates were found to contain
complete copies of CTXPhi. Southern blot analyses revealed that V. mimicus strain
PT5 contains two CTX prophages integrated at different sites within the V.
mimicus genome whereas V. mimicus strains PT48, 523-80, and 9583 each contain
tandemly arranged copies of CTXPhi. We detected the replicative form of CTXPhi,
pCTX, in all four of these V. mimicus isolates. The CTX prophage in strain PT5
was found to produce infectious CTXPhi particles. The nucleotide sequences of
CTXPhi genes orfU and zot from V. mimicus strain PT5 and V. cholerae strain
N16961 were identical, indicating contemporary horizontal transfer of CTXPhi
between these two species. The receptor for CTXPhi, the toxin-coregulated pilus,
which is encoded by another lysogenic filamentous bacteriophage, VPIPhi, was also
present in the CTXPhi-positive V. mimicus isolates. The nucleotide sequences of
VPIPhi genes aldA and toxT from V. mimicus strain PT5 and V. cholerae N16961 were
identical, suggesting recent horizontal transfer of this phage between V. mimicus
and V. cholerae. In V. mimicus, the vibrio pathogenicity island prophage was
integrated in the same chromosomal attachment site as in V. cholerae. These
results suggest that V. mimicus may be a significant reservoir for both CTXPhi
and VPIPhi and may play an important role in the emergence of new toxigenic V.
cholerae isolates.
PMID- 10678968
TI - Immunity reduces reservoir host competence of Peromyscus leucopus for Ehrlichia
phagocytophila.
AB - Infection with Ehrlichia phagocytophila in white-footed mice is transient and
followed by a strong immune response. We investigated whether the presence of
acquired immunity against E. phagocytophila precludes white-footed mice from
further maintenance of this agent in nature. Mice were infected with E.
phagocytophila via tick bite and challenged either 12 or 16 weeks later by Ixodes
scapularis nymphs infected with the same agent. Xenodiagnostic larvae fed upon
each mouse simultaneously with challenging nymphs and 1 week thereafter. Ticks
were tested for the agent by PCR, and the prevalence of infection was compared to
that in ticks that fed upon nonimmune control mice. Only 30% of immunized mice
sustained cofeeding transmission of E. phagocytophila between simultaneously
feeding infected and uninfected ticks, compared to 100% of control mice. An
average of 6.3% of xenodiagnostic ticks acquired Ehrlichia from previously
immunized mice when fed 1 week after the challenge, compared to 82.5% infection
in the control group. Although an immune response to a single infection with E.
phagocytophila in white-footed mice provided only partial protection against
reinfection with the same agent, the majority of mice were rendered reservoir
incompetent for at least 12 to 16 weeks. Immunity acquired by mice during I.
scapularis nymphal activity in early summer may exclude a large proportion of the
mouse population from maintaining E. phagocytophila during the period of larval
activity later in the season.
PMID- 10678969
TI - Differential regulation of CD4 lymphocyte recruitment between the upper and lower
regions of the genital tract during Chlamydia trachomatis infection.
AB - Genital infection with Chlamydia trachomatis results in both the local
recruitment of protective immune responses and an inflammatory infiltrate that
may also participate in tubal pathology. As a beginning to understanding the
etiology of immune system-mediated tubal pathology, we evaluated the regional
recruitment of lymphocyte subsets to different areas of the female genital tract
(GT) over the course of a murine infection with the mouse pneumonitis agent of
Chlamydia trachomatis (MoPn). Using flow cytometric techniques we found that the
CD4 lymphocyte subset was preferentially recruited to the upper GT (oviduct and
uterine horn) over the lower GT (cervical-vaginal region) throughout the course
of MoPn infection. The influx of CD4 cells also correlated with the expression of
endothelial cell adhesion molecules (ECAMs) and in vitro lymphocyte adherence in
the upper GT. Interestingly, the expression of ECAMs in the lower GT was not
maintained longer than 7 days after infection, even in the presence of viable
chlamydiae. Taken together, these data suggest that regulatory mechanisms of
lymphocyte recruitment differ between the upper and lower regions of the GT and
may influence the clearance of chlamydiae and the development of tubal pathology.
PMID- 10678970
TI - Phase 1 and phase 2 studies of Salmonella enterica serovar paratyphi A O-specific
polysaccharide-tetanus toxoid conjugates in adults, teenagers, and 2- to 4-year
old children in Vietnam.
AB - Salmonella enterica serovar Paratyphi A O-specific polysaccharide (O-SP) was
activated with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) and
bound to tetanus toxoid (TT) with adipic acid dihydrazide as a linker (SPA-TT(1))
or directly (SPA-TT(2)). In mice, these two conjugates elicited high levels of
immunoglobulin G (IgG) anti-lipopolysaccharide (LPS) in serum with bactericidal
activity (E. Konadu, J. Shiloach, D. A. Bryla, J. B. Robbins, and S. C. Szu,
Infect. Immun. 64:2709-2715, 1996). The safety and immunogenicity of the two
conjugates were then evaluated sequentially in Vietnamese adults, teenagers, and
2- to 4-year-old children. None of the vaccinees experienced significant side
effects, and all had preexisting LPS antibodies. At 4 weeks after injection,
there were significant increases of the geometric mean IgG and IgM anti-LPS
levels in the adults and teenagers: both conjugates elicited a greater than
fourfold rise in the IgG anti-LPS level in serum in >/=80% of the volunteers. SPA
TT(2) elicited slightly higher, though not statistically significantly, levels of
IgG anti-LPS than did SPA-TT(1) in these age groups. Accordingly, only SPA-TT(2)
was evaluated in the 2- to 4-year-old children. On a random basis, one or two
injections were administered 6 weeks apart to the children. No significant side
effects were observed, and the levels of preexisting anti-LPS in serum were
similar in children of all ages. A significant rise in the IgG anti-LPS titer was
elicited by the first injection (P = 0.0001); a second injection did not elicit a
booster response. Representative sera from all groups had bactericidal activity
that could be adsorbed by S. enterica serovar Paratyphi A LPS.
PMID- 10678971
TI - Colonization of the respiratory tract by a virulent strain of avian Escherichia
coli requires carriage of a conjugative plasmid.
AB - The E3 strain of E. coli was isolated in an outbreak of respiratory disease in
broiler chickens, and experimental aerosol exposure of chickens to this strain
induced disease similar to that seen in the field. In order to establish whether
the virulent phenotype of this strain was associated with carriage of particular
plasmids, four plasmid-cured derivatives, each lacking two or more of the
plasmids carried by the wild-type strain, were assessed for virulence. Virulence
was found to be associated with one large plasmid, pVM01. Plasmid pVM01 was
marked by introduction of the transposon TnphoA, carrying kanamycin resistance,
and was then cloned by transformation of E. coli strain DH5alpha. The cloned
plasmid was then reintroduced by conjugation into an avirulent plasmid-cured
derivative of strain E3 which lacked pVM01. The conjugant was shown to be as
virulent as the wild-type strain E3, establishing that this plasmid is required
for virulence following aerosol exposure. This virulence plasmid conferred
expression of a hydroxamate siderophore, but not colicins, on both strain E3 and
strain DH5alpha. Carriage of this plasmid was required for strain E3 to colonize
the respiratory tracts of chickens but was not necessary for colonization of the
gastrointestinal tract. However, the virulence plasmid did not confer virulence,
or the capacity to colonize the respiratory tract, on strain DH5alpha. Thus,
these studies have established that infection of chickens with E. coli strain E3
by the respiratory route is dependent on carriage of a conjugative virulence
plasmid, which confers the capacity to colonize specifically the respiratory
tract and which also carries genes for expression of a hydroxymate siderophore.
These findings will facilitate identification of the specific genes required for
virulence in these pathogens.
PMID- 10678972
TI - Colonic bacteria express an ulcerative colitis pANCA-related protein epitope.
AB - Bacteria are a suspected pathogenic factor in inflammatory bowel disease, but the
identity of the relevant microbial species remains unresolved. The pANCA
autoantibody is associated with most cases of ulcerative colitis (UC) and hence
reflects an immune response associated with the disease process. This study
addresses the hypothesis that pANCA identifies an antigen(s) expressed by
bacteria resident in the human colonic mucosa. Libraries of colonic bacteria were
generated using aerobic and anaerobic microbiologic culture conditions, and
bacterial pools and clonal isolates were evaluated for cross-reactive antigens by
immunoblot analysis using the pANCA monoclonal antibody Fab 5-3. Two major
species of proteins immunoreactive to pANCA monoclonal antibodies were detected
in bacteria from the anaerobic libraries. Colony isolates of the expressing
bacteria were identified as Bacteroides caccae and Escherichia coli. Isolation
and partial sequencing of the B. caccae antigen identified a 100-kDa protein
without database homologous sequences. The E. coli protein was biochemically and
genetically identified as the outer membrane porin OmpC. Enzyme-linked
immunosorbent assay with human sera demonstrated elevated immunoglobulin G anti
OmpC in UC patients compared to healthy controls. These findings demonstrate that
a pANCA monoclonal antibody detects a recurrent protein epitope expressed by
colonic bacteria and implicates colonic bacterial proteins as a target of the
disease-associated immune response.
PMID- 10678973
TI - Construction and characterization of a Salmonella enterica serovar typhimurium
clone expressing a salivary adhesin of Streptococcus mutans under control of the
anaerobically inducible nirB promoter.
AB - Attenuated Salmonella enterica serovar Typhimurium has been used for targeted
delivery of recombinant antigens to the gut-associated lymphoid tissues. One
potential problem associated with this vaccine approach is the likelihood of in
vivo instability of the plasmid constructs caused by constitutive hyperexpression
of the heterologous immunogen. The aim of this study was to generate and
characterize an expression system encoding the saliva-binding region (SBR) of
Streptococcus mutans antigen I/II adhesin, either alone or linked with the
mucosal adjuvant cholera toxin A2/B subunits (CTA2/B), under the control of the
inducible nirB promoter. This promoter is activated in an anaerobic environment
and within macrophages, which are the primary antigen-presenting cells involved
in phagocytosis and processing of Salmonella. The gene encoding the chimeric SBR
CTA2/B was amplified by PCR using primers containing appropriate restriction
sites for subcloning into pTETnirB, which contains the nirB promoter. The
resulting plasmid was introduced into serovar Typhimurium by electroporation.
Production of the SBR-CTA2/B chimeric protein under anaerobic conditions was
verified by enzyme-linked immunosorbent assay of whole-cell lysates on plates
coated with G(M1) ganglioside and developed with antibodies to SBR. Similar
procedures were followed for cloning the gene encoding SBR in serovar Typhimurium
under nirB control. Anaerobic expression of SBR was confirmed by Western blotting
of whole-cell lysates probed with anti-SBR antibodies. The resulting serovar
Typhimurium strains were administered by either the oral or the intranasal route
to mice, and colonization was assessed by microbiologic analysis of dissociated
spleens, Peyer's patches (PP), and nasal tissues. High numbers of the recombinant
strains persisted in PP and spleen for at least 21 days following oral challenge.
A single intranasal administration of the Salmonella clones to mice also resulted
in the colonization of the nasal tissues by the recombinant bacteria. Salmonellae
were recovered from nasal lymphoid tissues, superficial lymph nodes, internal
jugular lymph nodes, PP, and spleens of mice for at least 21 days after
challenge. This study provides quantitative evidence for colonization by
Salmonella strains expressing a recombinant protein under the control of the
inducible nirB promoter in PP or nasal tissues following a single oral or nasal
administration of the bacteria, respectively.
PMID- 10678974
TI - Relative roles of pneumolysin and hydrogen peroxide from Streptococcus pneumoniae
in inhibition of ependymal ciliary beat frequency.
AB - Ciliated ependymal cells line the ventricular system of the brain and the
cerebral aqueducts. This study characterizes the relative roles of pneumolysin
and hydrogen peroxide (H(2)O(2)) in pneumococcal meningitis, using the in vitro
ependymal ciliary beat frequency (CBF) as an indicator of toxicity. We have
developed an ex vivo model to examine the ependymal surface of the brain slices
cut from the fourth ventricle. The ependymal cells had cilia beating at a
frequency of between 38 and 44Hz. D39 (wild-type) and PLN-A (pneumolysin
negative) pneumococci at 10(8) CFU/ml both caused ciliary slowing. Catalase
protected against PLN-A-induced ciliary slowing but afforded little protection
from D39. Lysed PLN-A did not reduce CBF, whereas lysed D39 caused rapid ciliary
stasis. There was no effect of catalase, penicillin, or catalase plus penicillin
on the CBF. H(2)O(2) at a concentration as low as 100 microM caused ciliary
stasis, and this effect was abolished by coincubation with catalase. An additive
inhibition of CBF was demonstrated using a combination of both toxins. A
significant inhibition of CBF at between 30 and 120 min was demonstrated with
both toxins compared with either H(2)O(2) (10 microM) or pneumolysin (1 HU/ml)
alone. D39 released equivalent levels of H(2)O(2) to those released by PLN-A, and
these concentrations were sufficient to cause ciliary stasis. The brain slices
did not produce H(2)O(2), and in the presence of 10(8) CFU of D39 or PLN-A per ml
there was no detectable bacterially induced increase of H(2)O(2) release from the
brain slice. Coincubation with catalase converted the H(2)O(2) produced by the
pneumococci to H(2)O. Penicillin-induced lysis of bacteria dramatically reduced
H(2)O(2) production. The hemolytic activity released from D39 was sufficient to
cause rapid ciliary stasis, and there was no detectable release of hemolytic
activity from the pneumolysin-negative PLN-A. These data demonstrate that D39
bacteria released pneumolysin, which caused rapid ciliary stasis. D39 also
released H(2)O(2), which contributed to the toxicity, but this was masked by the
more severe effects of pneumolysin. H(2)O(2) released from intact PLN-A was
sufficient to cause rapid ciliary stasis, and catalase protected against H(2)O(2)
induced cell toxicity, indicating a role for H(2)O(2) in the response. There is
also a slight additive effect of pneumolysin and H(2)O(2) on ependymal toxicity;
however, the precise mechanism of action and the role of these toxins in
pathogenesis remain unclear.
PMID- 10678975
TI - Regulation of immunoglobulin G2 production by prostaglandin E(2) and platelet
activating factor.
AB - Patients with localized juvenile periodontitis (LJP) have elevated levels of
immunoglobulin G2 (IgG2) in their sera. This is also observed in vitro when
peripheral blood leukocytes from LJP patients are stimulated with pokeweed
mitogen. In previous studies, we showed that lymphocytes from subjects with no
periodontitis (NP subjects) produced substantial amounts of IgG2 when they were
cultured with monocytes from LJP patients (LJP monocytes). These observations
indicate that monocytes or monocyte-derived mediators are positive regulators of
the production of IgG2. The present study was initiated to determine if secreted
factors from LJP monocytes were capable of enhancing IgG2 production and to
determine if prostaglandin E2 (PGE(2)), which LJP monocytes produce at elevated
levels, enhances IgG2 production. Experiments in a transwell system and with
monocyte-conditioned media indicated that cell-cell contact was not necessary for
LJP monocytes to augment the production of IgG2 by T and B cells from NP
subjects. Moreover, the production of IgG2 was selectively induced by the
addition of PGE(2) or platelet-activating factor (PAF), another lipid cytokine,
which can elevate PGE(2) synthesis. Furthermore, IgG2 production was abrogated
when cells were treated with indomethacin, a cyclooxygenase inhibitor that blocks
the synthesis of PGE(2), or the PAF antagonists CV3988 and TEPC-15. The effects
of indomethacin were completely reversed by PGE(2), indicating that this is the
only prostanoid that is essential for the production of IgG2. Similarly, PGE(2)
reversed the effects of a PAF antagonist, suggesting that the effects of PAF are
mediated through the induction of PGE(2) synthesis. Together, these data indicate
that PGE(2) and PAF are essential for the production of IgG2.
PMID- 10678976
TI - Immune responses to specific antigens of Streptococcus pneumoniae and Moraxella
catarrhalis in the respiratory tract.
AB - Streptococcus pneumoniae and Moraxella catarrhalis are two common respiratory
pathogens, colonizing as many as 54 and 72% of children, respectively, by 1 year
of age. The immune responses to surface protein A of S. pneumoniae (PspA) and the
high-molecular-weight outer membrane protein of M. catarrhalis (UspA) in the sera
of various age groups in the general population and in the nasopharynges of 30
children monitored from birth through 1 year of age were evaluated.
Immunoglobulin G (IgG) was the dominant serum antibody to PspA and UspA. Whereas
the serum antibody response to PspA peaked in childhood, the antibody response to
UspA peaked in adulthood. In the first 2 years of life, comparable amounts of IgM
and IgG antibodies to both proteins were observed. In older persons, IgG
antibodies to both antigens predominated over IgM antibodies. The levels of IgA
antibody to these antigens in serum remained low during the first 2 years of
life. The levels of IgM antibody to the two antigens in serum exceeded the levels
of IgA antibody to the same two antigens throughout life. Although IgA was the
dominant antibody to PspA and UspA in airway secretions, it was detected in a
minority of the children (3 of 15 for PspA and 0 of 15 for UspA). Even the
majority of the children previously colonized with these pathogens lacked
antibody to them in their secretions.
PMID- 10678977
TI - Molecular and evolutionary characterization of the cp32/18 family of supercoiled
plasmids in Borrelia burgdorferi 297.
AB - In this study, we characterized seven members of the cp32/18 family of
supercoiled plasmids in Borrelia burgdorferi 297. Complete sequence analysis of a
21-kb plasmid (cp18-2) confirmed that the strain 297 plasmids are similar in
overall content and organization to their B31 counterparts. Of the 31 open
reading frames (ORFs) in cp18-2, only three showed sequence relatedness to
proteins with known functions, and only one, a ParA/SopA ortholog, was related to
nonborrelial polypeptides. Besides the lipoproteins, none of the ORFs appeared
likely to encode a surface-exposed protein. Comparison with the B31 genomic
sequence indicated that paralogs for most of the ORFs in cp18-2 can be identified
on other genetic elements. cp18-2 was found to lack a 9- to 10-kb fragment
present in the 32-kb homologs which, by extrapolation from the B31 cp32
sequences, contains at least 15 genes presumed to be unnecessary for plasmid
maintenance. Sequence analysis of the lipoprotein-encoding variable loci provided
evidence that recombinatorial processes within these regions may result in the
acquisition of exogenous DNA. Pairwise analysis with random shuffling revealed
that the multiple lipoproteins (Mlp; formerly designated 2.9 LPs) fall into two
distinct homology groups which appear to have arisen by gene fusion events
similar to those recently proposed to have generated the three OspE, OspF, and
Elp lipoprotein families (D. R. Akins, M. J. Caimano, X. Yang, F. Cerna, M. V.
Norgard, and J. D. Radolf, Infect. Immun. 67:1526-1532, 1999). Comparative
analysis of the variable regions also indicated that recombination within the
loci of each plasmid may occur independently. Last, comparison of variable loci
revealed that the cp32/18 plasmid complements of the B31 and 297 isolates differ
substantially, indicating that the two strains have been subject to divergent
adaptive pressures. In addition to providing evidence for two different types of
recombinatorial events involving cp32/18 plasmids, these findings underscore the
need for genetic analysis of diverse borrelial isolates in order to elucidate the
Lyme disease spirochete's complex parasitic strategies.
PMID- 10678978
TI - Analysis of the F antigen-specific papA alleles of extraintestinal pathogenic
Escherichia coli using a novel multiplex PCR-based assay.
AB - Polymorphisms in PapA, the major structural subunit and antigenic determinant of
P fimbriae of extraintestinal pathogenic Escherichia coli, are of considerable
epidemiological, phylogenetic, and immunotherapeutic importance. However, to
date, no method other than DNA sequencing has been generally available for their
detection. In the present study, we developed and rigorously validated a novel
PCR-based assay for the 11 recognized variants of papA and then used the new
assay to assess the prevalence, phylogenetic distribution, and bacteriological
associations of the papA alleles among 75 E. coli isolates from patients with
urosepsis. In comparison with conventional F serotyping, the assay was extremely
sensitive and specific, evidence that papA sequences are highly conserved within
each of the traditionally recognized F serotypes despite the diversity observed
among F types. In certain strains, the assay detected serologically occult copies
of papA, of which some were shown to represent false-negative serological results
and others were shown to represent the presence of nonfunctional pap fragments.
Among the urosepsis isolates, the assay revealed considerable segregation of papA
alleles according to O:K:H serotype, consistent with vertical transmission within
clones, but with exceptions which strongly suggested horizontal transfer of papA
alleles between lineages. Sequencing of papA from two strains that were papA
positive by probe and PCR but F negative in the new PCR assay led to the
discovery of two novel papA variants, one of which was actually more prevalent
among the urosepsis isolates than were several of the known papA alleles. These
findings provide novel insights into the papA alleles of extraintestinal
pathogenic E. coli and indicate that the F PCR assay represents a versatile new
molecular tool for epidemiological and phylogenetic investigations which should
make rapid, specific detection of papA alleles available to any laboratory with
PCR capability.
PMID- 10678979
TI - Bacterial induction of beta interferon in mice is a function of the
lipopolysaccharide component.
AB - We investigated the reason for the inability of lipopolysaccharide (LPS)
resistant (Lps-defective [Lps(d)]) C57BL/10ScCr mice to produce beta interferon
(IFN-beta) when stimulated with bacteria. For this purpose, the IFN-beta and
other macrophage cytokine responses induced by LPS and several killed gram
negative and gram-positive bacteria in LPS-sensitive (Lps-normal [Lps(n)];
C57BL/10ScSn and BALB/c) and Lps(d) (C57BL/10ScCr and BALB/c/l) mice in vitro and
in vivo were investigated on the mRNA and protein levels. In addition, double
stranded RNA (dsRNA) was used as a nonbacterial stimulus. LPS and all gram
negative bacteria employed induced IFN-beta in the Lps(n) mice but not in the
Lps(d) mice. All gram-positive bacteria tested failed to induce significant
amounts of IFN-beta in all four of the mouse strains used. As expected, all other
cytokines tested (tumor necrosis factor alpha, interleukin 1alpha [IL-1alpha], IL
6, and IL-10) were differentially induced by gram-negative and gram-positive
bacteria. Stimulation with dsRNA induced IFN-beta and all other cytokines
mentioned above in all mouse strains, regardless of their LPS sensitivities. The
results suggest strongly that LPS is the only bacterial component capable of
inducing IFN-beta in significant amounts that are readily detectable under the
conditions used in this study. Consequently, in mice, IFN-beta is inducible only
by gram-negative bacteria, but not in C57BL/10ScCr or other LPS-resistant mice.
PMID- 10678980
TI - Serum resistance in Haemophilus ducreyi requires outer membrane protein DsrA.
AB - Haemophilus ducreyi is resistant to killing by normal serum antibody and
complement. We discovered an H. ducreyi outer membrane protein required for
expression of serum resistance and termed it DsrA (for "ducreyi serum resistance
A"). The dsrA locus was cloned, sequenced, and mutagenized. An isogenic mutant
(FX517) of parent strain 35000 was constructed and characterized, and it was
found to no longer express dsrA. FX517 was at least 10-fold more serum
susceptible than 35000. DsrA was expressed by all strains of H. ducreyi tested,
except three naturally occurring, avirulent, serum-sensitive strains. FX517 and
the three naturally occurring dsrA-nonexpressing strains were complemented in
trans with a plasmid expressing dsrA. All four strains were converted to a serum
resistant phenotype, including two that contained truncated lipooligosaccharide
(LOS). Therefore, serum resistance in H. ducreyi does not require expression of
full-length LOS but does require expression of dsrA. The dsrA locus from eight
additional H. ducreyi strains was sequenced, and the deduced amino acid sequences
were more than 85% identical. The major difference between the DsrA proteins was
due to the presence of one, two, or three copies of the heptameric amino acid
repeat NTHNINK. These repeats account for the variability in apparent molecular
mass of the monomeric form of DsrA (28 to 35 kDa) observed in sodium dodecyl
sulfate-polyacrylamide gel electrophoresis. Since DsrA is present in virulent
strains, is highly conserved, and is required for serum resistance, we speculate
that it may be a virulence factor and a potential vaccine candidate.
PMID- 10678981
TI - Genetic resistance to experimental infection with Mycobacterium bovis in red deer
(Cervus elaphus).
AB - Tuberculosis (Tb) caused by Mycobacterium bovis is a worldwide threat to
livestock and humans. One control strategy is to breed livestock that are more
resistant to Mycobacterium bovis. In a 3-year heritability study 6 farmed red
deer stags were selected from 39 on the basis of their differing responses to
experimental challenge via the tonsillar sac with approximately 500 CFU of M.
bovis. Two stags remained uninfected, two were moderately affected, and two
developed serious spreading Tb. Seventy offspring, bred from these six stags by
artificial insemination using stored semen, were similarly challenged with M.
bovis. The offspring showed patterns of response to M. bovis challenge similar to
those of their sires, providing evidence for a strong genetic basis to resistance
to Tb, with an estimated heritability of 0.48 (standard error, 0.096; P < 0. 01).
This is the first time the heritability of Tb resistance in domestic livestock
has been measured. The breeding of selection lines of resistant and susceptible
deer will provide an ideal model to study the mechanisms of Tb resistance in a
ruminant and could provide an additional strategy for reducing the number and
severity of outbreaks of Tb in farmed deer herds. Laboratory studies to identify
genetic and immunological markers for resistance to Tb are under way. Preliminary
studies showed no associations between NRAMP or DRB genes and resistance to Tb in
deer. Patterns of immune responses seen in resistant animals suggest that both
innate and acquired pathways of immunity are necessary to produce the resistant
phenotype.
PMID- 10678982
TI - Endotoxin-induced lung inflammation is independent of the complement membrane
attack complex.
AB - Several products of the activated complement system are known to modulate
endothelial cell function in vitro. It has been shown that the membrane attack
complex (MAC) (C5b-C9) can enhance tumor necrosis factor alpha (TNF-alpha)
induced expression of P- and E-selectin and intercellular adhesion molecule type
1 in cell cultures of human umbilical vein endothelial cells. In the present
study the potential role of this synegism for lung injury during endotoxin
mediated septic shock in vivo was examined using a model of C6-deficient PVG (C-)
(RT1(C)) rats and the congenic PVG (C+) (RT1(C)) strain. Following administration
of a high (5 mg/kg) or low (0.5 mg/kg) dose of lipopolysaccharide (LPS)
(Escherichia coli O55:B5), we determined the expression of cytokines, chemokines,
and adhesion molecules as well as the recruitment of leukocytes in the lung.
Challenge with intraperitoneal i.p. injections of LPS resulted in a strong
induction of TNF-alpha, interleukin-1alpha/beta, cytokine-induced neutrophil
chemoattractant, interferon-inducible protein 10, macrophage inflammatory
proteins 1alpha and 2, macrophage chemotactic protein 1, and P-selectin. However,
there were no significant differences between PVG (C-) and PVG (C+) rats.
Immunoperoxidase staining showed a similar increase of lung infiltration by
CD11b/c(+) leukocytes in both rat strains. We therefore conclude that the
described synergism between TNF-alpha and the MAC of the complement system on the
induction of endothelial adhesion molecules is dispensable for inflammatory
processes during endotoxin-mediated septic shock in vivo.
PMID- 10678984
TI - Protection against candidiasis by an immunoglobulin G3 (IgG3) monoclonal antibody
specific for the same mannotriose as an IgM protective antibody.
AB - We previously reported that a liposome-mannan vaccine (L-mann) of Candida
albicans induces production of mouse antibodies that protect against disseminated
candidiasis and vaginal infection. Immunoglobulin M (IgM) monoclonal antibody
(MAb) B6.1, specific for a C. albicans cell surface beta-1,2-mannotriose,
protects mice against both infections. Another IgM MAb, termed B6, which is
specific for a different cell surface mannan epitope, does not protect against
disseminated candidiasis. The B6.1 epitope is displayed homogeneously over the
entire cell surface, compared to a patchy distribution of the B6 epitope. To
determine if protection is restricted to an IgM class of antibody, we tested an
IgG antibody. MAb C3.1 was obtained from L-mann-immunized mice. By results of
sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, capture
enzyme-linked immunosorbent assay, and immunodiffusion tests, MAb C3.1 is an IgG3
isotype. By epitope inhibition assays, we determined that MAb C3.1 is specific
for same mannotriose as MAb B6. 1. As expected by the results of the inhibition
assays, immunofluorescence microscopy showed that the C3.1 epitope is distributed
on the yeast cell surface in a pattern identical to that of the B6.1 epitope.
Kidney CFU and mean survival times of infected mice pretreated with MAb C3.1
indicated that the antibody enhanced resistance of mice against disseminated
candidiasis. Mice in pseudoestrus that were given MAb C3.1 prior to vaginal
infection developed fewer vaginal Candida CFU than control animals that received
buffered saline instead of the antibody. The finding that an IgG3 antibody is
protective is consistent with our hypothesis that epitope specificity and
complement activation are related to the ability of an antibody to protect
against candidiasis.
PMID- 10678983
TI - Comparative genome analysis of the pathogenic spirochetes Borrelia burgdorferi
and Treponema pallidum.
AB - A comparative analysis of the predicted protein sequences encoded in the complete
genomes of Borrelia burgdorferi and Treponema pallidum provides a number of
insights into evolutionary trends and adaptive strategies of the two spirochetes.
A measure of orthologous relationships between gene sets, termed the orthology
coefficient (OC), was developed. The overall OC value for the gene sets of the
two spirochetes is about 0.43, which means that less than one-half of the genes
show readily detectable orthologous relationships. This emphasizes significant
divergence between the two spirochetes, apparently driven by different biological
niches. Different functional categories of proteins as well as different protein
families show a broad distribution of OC values, from near 1 (a perfect, one-to
one correspondence) to near 0. The proteins involved in core biological
functions, such as genome replication and expression, typically show high OC
values. In contrast, marked variability is seen among proteins that are involved
in specific processes, such as nutrient transport, metabolism, gene-specific
transcription regulation, signal transduction, and host response. Differences in
the gene complements encoded in the two spirochete genomes suggest active
adaptive evolution for their distinct niches. Comparative analysis of the
spirochete genomes produced evidence of gene exchanges with other bacteria,
archaea, and eukaryotic hosts that seem to have occurred at different points in
the evolution of the spirochetes. Examples are presented of the use of sequence
profile analysis to predict proteins that are likely to play a role in
pathogenesis, including secreted proteins that contain specific protein-protein
interaction domains, such as von Willebrand A, YWTD, TPR, and PR1, some of which
hitherto have been reported only in eukaryotes. We tentatively reconstruct the
likely evolutionary process that has led to the divergence of the two spirochete
lineages; this reconstruction seems to point to an ancestral state resembling the
symbiotic spirochetes found in insect guts.
PMID- 10678985
TI - Influence of synthetic antiendotoxin peptides on lipopolysaccharide (LPS)
recognition and LPS-induced proinflammatory cytokine responses by cells
expressing membrane-bound CD14.
AB - Lipopolysaccharides (LPS) are proinflammatory bacterial products implicated in
the pathogenesis of gram-negative sepsis and septic shock. Polymyxin B (PMB), a
cyclic, cationic peptide antibiotic, inhibits biological activities of LPS
through high-affinity binding to the lipid A moiety. Small synthetic peptides
have been designed to mimic the primary and secondary structures of PMB to
determine structural requirements for binding and detoxification of lipid A and
to assess possible therapeutic potential. The purpose of this study was to
compare and contrast the endotoxin-neutralizing activities of two synthetic
antiendotoxin peptides (SAEP-2 and SAEP-4), PMB, and an LPS core-specific
monoclonal antibody (MAb), WN1 222-5, based on their abilities to inhibit CD14
mediated target cell uptake of fluorescein isothiocyanate (FITC)-conjugated LPS,
detected by flow cytometry and confocal microscopy, and LPS-induced production of
the proinflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor
alpha (TNF-alpha), as measured by bioassays. PMB and SAEP-4 produced dose
dependent inhibition of FITC-LPS uptake by CD14-transfected Chinese hamster ovary
fibroblasts (CHO-CD14 cells) and by human peripheral blood mononuclear cells. The
anti-LPS MAb, WN1 222-5, also blocked LPS uptake by these cells and synergized
with PMB and SAEP-4. LPS-induced IL-6 release was inhibited by PMB, SAEP-4, and
MAb WN1 222-5, and these inhibitory activities were additive or synergistic. LPS
induced TNF-alpha release by PBMC was also inhibited by PMB and SAEP-4 alone and
in combination with anti-LPS MAb. SAEP-2, in contrast, produced comparatively
minor decrements in cellular uptake of LPS and LPS-induced cytokine responses,
and did so only in the absence of serum, while a nonsense peptide exerted no
discernible inhibitory effect on LPS uptake or LPS-induced cytokine expression in
the presence or absence of serum. Thus, PMB and SAEP-4, like the LPS-reactive
MAb, WN1 222-5, block proinflammatory activities of LPS in part by preventing LPS
recognition by membrane-bound CD14-expressing target cells. Differences in
peptide structure, however, like those exemplified by SAEP-2 and SAEP-4, may
differentially affect the endotoxin-neutralizing potency of these peptides
despite similar binding activity against lipid A, reflecting possible differences
in peptide solubility or peptide regulation of intracellular signal transduction.
PMID- 10678986
TI - Bacterial phosphorylcholine decreases susceptibility to the antimicrobial peptide
LL-37/hCAP18 expressed in the upper respiratory tract.
AB - A number of pathogens of the upper respiratory tract express an unusual
prokaryotic structure, phosphorylcholine (ChoP), on their cell surface. We tested
the hypothesis that ChoP, also found on host membrane lipids in the form of
phosphatidylcholine, acts so as to decrease killing by antimicrobial peptides
that target differences between bacterial and host membranes. In Haemophilus
influenzae, ChoP is a phase-variable structure on the oligosaccharide portion of
the lipopolysaccharide (LPS). There was a bactericidal effect of the peptide LL
37/hCAP18 on a nontypeable H. influenzae strain, with an increasing selection for
the ChoP(+) phase as the concentration of the peptide was raised from 0 to 10
microgram/ml. Moreover, constitutive ChoP-expressing mutants of unrelated strains
showed up to 1,000-fold-greater survival compared to mutants without ChoP. The
effect of ChoP on resistance to killing by LL-37/hCAP18 was dependent on the salt
concentration and was observed only when bacteria were grown in the presence of
environmental choline, a requirement for the expression of ChoP on the LPS.
Further studies established that there is transcription of the LL-37/hCAP18 gene
on the epithelial surface of the human nasopharynx in situ and inducible
transcription in epithelial cells derived from the upper airway. The presence of
highly variable amounts of LL-37/hCAP18 in normal nasal secretions (<1.2 to >80
microgram/ml) was demonstrated with an antibody against this peptide. It was
concluded that ChoP alters the bacterial cell surface so as mimic host membrane
lipids and decrease killing by LL-37/hCAP18, an antimicrobial peptide that may be
expressed on the mucosal surface of the nasopharynx in bactericidal
concentrations.
PMID- 10678988
TI - Interaction between Burkholderia pseudomallei and Acanthamoeba species results in
coiling phagocytosis, endamebic bacterial survival, and escape.
AB - Burkholderia pseudomallei causes melioidosis, a potentially fatal disease whose
clinical outcomes include rapid-onset septicemia and relapsing and delayed-onset
infections. Like other facultative intracellular bacterial pathogens, B.
pseudomallei is capable of survival in human phagocytic cells, but unlike
mycobacteria, Listeria monocytogenes, and Salmonella serovar Typhimurium, the
species has not been reported to survive as an endosymbiont in free-living
amebae. We investigated the consequences of exposing Acanthamoeba astronyxis, A.
castellani, and A. polyphaga to B. pseudomallei NCTC 10276 in a series of
coculture experiments. Bacterial endocytosis was observed in all three
Acanthamoeba species. A more extensive range of cellular interactions including
bacterial adhesion, incorporation into amebic vacuoles, and separation was
observed with A. astronyxis in timed coculture experiments. Amebic trophozoites
containing motile intravacuolar bacilli were found throughout 72 h of coculture.
Confocal microscopy was used to confirm the intracellular location of endamebic
B. pseudomallei cells. Transmission electron microscopy of coculture preparations
revealed clusters of intact bacilli in membrane-lined vesicles inside the
trophozoite cytoplasm; 5 x 10(2) CFU of bacteria per ml were recovered from lysed
amebic trophozoites after 60 min of coculture. Demonstration of an interaction
between B. pseudomallei and free-living acanthamebae in vitro raises the
possibility that a similar interaction in vivo might affect environmental
survival of B. pseudomallei and subsequent human exposure. Endamebic passage of
B. pseudomallei warrants further investigation as a potential in vitro model of
intracellular B. pseudomallei infection.
PMID- 10678987
TI - Complement activation in Mycoplasma fermentans-induced mycoplasma clearance from
infected cells: probing of the organism with monoclonal antibodies against
M161Ag.
AB - Mycoplasma fermentans, a cell wall-less prokaryote, is capable of infecting
humans and has been suggested to serve as a cofactor in AIDS development.
Recently, we discovered a novel lipoprotein with a molecular mass of 43 kDa
originating from M. fermentans. This protein, named M161Ag, activated human
complement via the alternative pathway and efficiently induced the
proinflammatory cytokines interleukin 1beta (IL-1beta), tumor necrosis factor
alpha, IL-6, IL-10, and IL-12 in human peripheral blood monocytes. It is likely
that M161Ag of M. fermentans affects the host immune system upon mycoplasma
infection. In this study, we developed monoclonal antibodies (MAbs) against
M161Ag and examined the direct role of complement in M. fermentans infection
using these MAbs as probes. M. fermentans was rapidly cleared from the surfaces
of infected cells by human complement, but a low-grade infection persisted in
human tumor cell lines. Mycoplasma particles remaining alive in host cells may
cause recurrent infection, and liberated M161Ag may serve as a biological
response modifier affecting both innate and acquired immunity.
PMID- 10678989
TI - Roles of the surface layer proteins of Campylobacter fetus subsp. fetus in ovine
abortion.
AB - The role of the surface (S)-layer proteins of Campylobacter fetus subsp. fetus
has been investigated using an ovine model of abortion. Wild-type strain 23D
induced abortion in up to 90% of pregnant ewes challenged subcutaneously.
Isolates recovered from both dams and fetuses expressed S-layer proteins with
variable molecular masses. The spontaneous S-layer-negative variant, strain 23B,
neither colonized nor caused abortions in pregnant ewes. A series of isogenic
sapA and recA mutants, derived from 23D, also were investigated in this model. A
mutant (501 [sapA recA(+)]) caused abortion in one of five challenged animals and
was recovered from the placenta of a second animal. Another mutant (502 [sapA
recA]) with no S-layer protein expression caused no colonization or abortions in
challenged animals but caused abortion when administered intraplacentally.
Mutants 600(2) and 600(4), both recA, had fixed expression of 97- and 127-kDa S
layer proteins, respectively. Two of the six animals challenged with mutant
600(4) were colonized, but there were no abortions. As expected, all five strains
recovered expressed a 127-kDa S-layer protein. In contrast, mutant 600(2) was
recovered from the placentas of all five challenged animals and caused abortion
in two. Unexpectedly, one of the 16 isolates expressed a 127-kDa rather than a 97
kDa S-layer protein. Thus, these studies indicate that S-layer proteins appear
essential for colonization and/or translocation to the placenta but are not
required to mediate fetal injury and that S-layer variation may occur in a recA
strain.
PMID- 10678990
TI - Enhanced susceptibility to subcutaneous abscess formation and persistent
infection around catheters is associated with sustained interleukin-1beta levels.
AB - A persistent Staphylococcus epidermidis infection in mice around a subcutaneous
polyvinylpyrrolidone-grafted silicon elastomer catheter (SEpvp) but not around a
conventional silicon elastomer catheter was observed. With SEpvp pericatheter
tissue, protracted and exaggerated interleukin-1beta (IL-1beta) production was
found. Apparently, sustained levels of IL-1beta are associated with enhanced
susceptibility to biomaterial-associated S. epidermidis infection.
PMID- 10678991
TI - Macropinocytosis as a mechanism of entry into primary human urethral epithelial
cells by Neisseria gonorrhoeae.
AB - Gonococcal entry into primary human urethral epithelial cells (HUEC) can occur by
macropinocytosis. Scanning and transmission electron microscopy revealed
lamellipodia surrounding gonococci, and confocal laser scanning microscopy
analysis showed organisms colocalized with M(r) 70,000 fluorescein isothiocyanate
labeled dextran within the cells. Phosphoinositide 3-kinase inhibitors and an
actin polymerization inhibitor prevented macropinocytic entry of gonococci into
HUEC.
PMID- 10678992
TI - Cytotoxic cell vacuolating activity from Vibrio cholerae hemolysin.
AB - A Vibrio cholerae cytotoxin, designated VcVac, was found to cause vacuolation in
Vero cells. It was originally detected in the pathogenic O1 Amazonia variant of
V. cholerae and later shown to be produced in environmental strains and some El
Tor strains. Comparison of VcVac production in various strains suggested that
hemolysin was responsible for the vacuolating phenotype. Genetic experiments
established a firm correlation between vacuolation and hemolysin production. The
mammalian cell vacuolating activity of the V. cholerae hemolysin is a new
property of this protein and points to a previously unknown type of interaction
between V. cholerae and its host.
PMID- 10678993
TI - Effective preexposure tuberculosis vaccines fail to protect when they are given
in an immunotherapeutic mode.
AB - Two vaccine formulations previously shown to induce protective immunity in mice
and prevention of long-term necrosis in guinea pigs were tested as potential
immunotherapeutic vaccines in mice earlier infected by aerosol with Mycobacterium
tuberculosis. Neither vaccine had any effect on the course of the infection in
the lungs, but both reduced the bacterial load in the spleen. Similarly,
inoculation with Mycobacterium bovis BCG had no effect whatsoever and, if given
more than once, appeared to induce an increasingly severe pyogranulomatous
response in the lungs of these mice.
PMID- 10678994
TI - Intestinal epithelial cell apoptosis following Cryptosporidium parvum infection.
AB - Cryptosporidium parvum induces moderate levels of apoptosis of cultured human
intestinal epithelial cells, which are maximal at 24 h after infection. Apoptosis
is further increased in C. parvum-infected cells by inhibition of NF-kappaB. C.
parvum infection also attenuates epithelial apoptosis induced by strongly
proapoptotic agents. The data suggest C. parvum has developed strategies to limit
apoptosis in order to facilitate its growth and maturation in the early period
after epithelial cell infection.
PMID- 10678995
TI - Conservation and heterogeneity of vlsE among human and tick isolates of Borrelia
burgdorferi.
AB - The vls (variable major protein [VMP]-like sequence) locus of Borrelia
burgdorferi encodes an antigenic variation system that closely resembles the VMP
system of relapsing fever borreliae. To determine whether vls sequences are
present consistently in low-passage, infectious isolates of B. burgdorferi, 22
blood and erythema migrans biopsy isolates from Lyme disease patients in
Westchester County, New York, were examined by Southern blot and PCR analysis.
Each of the strains contained a single plasmid varying in size from 21 to 38 kb
that hybridized strongly with a vlsE probe based on the B. burgdorferi B31
sequence. In contrast, PCR products were obtained with only 10 of the 22 strains
when primers corresponding to the 5' and 3' regions of the B31 vlsE sequence
outside the variable cassette region were used. Only 2 of 16 B. burgdorferi
infected tick specimens yielded detectable PCR product. Eight of 10 strains that
yielded a PCR product under these conditions were type 1 (a genotype with a high
rate of dissemination), according to PCR-restriction fragment length polymorphism
analysis of intergenic rDNA sequences, whereas the isolates that did not yield
vlsE PCR products were either type 2 or type 3. Comparison of the sequences of
cloned PCR products from the patient isolates indicated a high degree of identity
to the B31 sequence, with most of the differences restricted to the hypervariable
regions known to undergo sequence variation. Taken together, these results both
reinforce previous evidence that vls sequences are present consistently in low
passage Lyme disease spirochetes and indicate that both highly conserved and
heterogeneous subgroups exist with regard to vlsE sequences.
PMID- 10678996
TI - T-cell epitopes in variable segments of Chlamydia trachomatis major outer
membrane protein elicit serovar-specific immune responses in infected humans.
AB - We previously identified 18 stimulatory Chlamydia trachomatis major outer
membrane protein (MOMP) peptides containing at least 23 epitopes presented with
various HLA class II allotypes. Only one peptide contained an epitope localized
in a variable segment (VS2). Continued studies reported here identified a total
of five VS peptides containing T-cell epitopes that are distributed among MOMPs
VS1, VS2, and VS4. Only MOMP-primed T-cell cultures from subjects infected with
serovar E responded to the serovar E VS peptides, while the response of such
cultures to constant-segment peptides was independent of the infecting serovar.
Furthermore, MOMP-primed T cells proliferated in response only to the VS peptides
encoded in serovar E but not to the corresponding peptides derived from serovar
F, I, or J, confirming that these responses were serovar specific.
PMID- 10678997
TI - Effects of iron on extracellular and intracellular growth of Penicillium
marneffei.
AB - Killing of intracellular Penicillium marneffei conidia is demonstrated in gamma
interferon-lipopolysaccharide-activated human THP1 and mouse J774 cells. Iron
overload significantly reduces the antifungal activity of macrophages. Likewise,
exogenous iron enhances and iron chelators inhibit the extracellular growth of P.
marneffei. These results suggest that iron availability critically affects
immunity to and the pathogenicity of P. marneffei.
PMID- 10678998
TI - Stability of Borrelia burgdorferi bdr loci in vitro and in vivo.
AB - The Lyme disease spirochete Borrelia burgdorferi expresses diverse subsurface yet
antigenically cross-reactive Bdr protein paralogs from distinct circular- and
linear-plasmid loci. We assessed the possible effects of in vitro and in vivo
growth on bdr locus structure, searching for recombinational events leading to
either deletions or insertions of central repeat units or novel amino- and
carboxy-terminus combinations. Our data indicate that, apart from plasmid loss
during in vitro cultivation, the bdr paralog loci of strain B31 are stable. This
suggests that recombinatorial variation of bdr genes is not essential for
persistent mammalian infection.
PMID- 10678999
TI - Lipopolysaccharide entry in the damaged cornea and specific uptake by
polymorphonuclear neutrophils.
AB - Bacterial lipopolysaccharide (LPS) is an important agent of induction of ocular
pathology following corneal injury or wearing of contaminated contact lenses. The
mechanism of LPS uptake through the corneal epithelium is unclear, and the role
played by inflammatory cells in this phenomenon has not been previously assessed.
Fluorescein isothiocyanate-labeled LPS from Escherichia coli was deposited onto
the abraded corneas of New Zealand White rabbits. Epifluorescence microscopy of
living excised corneas revealed diffuse LPS staining in the epithelial and
stromal layers only in the vicinity of the abrasion. In addition, specific
cellular uptake of LPS was suggested by fluorescence staining of cells along the
abrasion site. In a second series of experiments, an anti-CD18 polyclonal
antibody was used to block infiltration of polymorphonuclear neutrophils (PMN)
into the cornea. In these experiments, a diffuse distribution of fluorescent LPS
was still observed along the abrasion, but the specific cellular uptake was
abolished. The findings indicate that LPS enters the cornea via diffuse
penetration at sites of injury and that specific cellular uptake of LPS occurs
within the cornea via PMN which have migrated into the damaged tissue.
PMID- 10679000
TI - Bordetella pertussis virulence factors affect phagocytosis by human neutrophils.
AB - The interaction between human neutrophils and wild-type Bordetella pertussis or
mutants expressing altered lipopolysaccharide or lacking virulence factors
pertussis toxin, adenylate cyclase toxin, dermonecrotic toxin, filamentous
hemagglutinin (FHA), pertactin, or BrkA-was examined. In the absence of
antibodies, the wild-type strain and the mutants, with the exception of mutants
lacking FHA, attached efficiently to neutrophils. The addition of opsonizing
antibodies caused a significant reduction (approximately 50%) in attachment of
the wild-type strain and most of the mutants expressing FHA, suggesting that
bacterium-mediated attachment is more efficient than Fc-mediated attachment.
Phagocytosis was also examined. In the absence of antibodies, about 12% of the
wild-type bacteria were phagocytosed. Opsonization caused a statistically
significant reduction in phagocytosis (to 3%), possibly a consequence of reduced
attachment. Phagocytosis of most of the mutants was similar to that of the wild
type, with the exception of the mutants lacking adenylate cyclase toxin. About
70% of the adenylate cyclase toxin mutants were phagocytosed, but only in the
presence of opsonizing antibody, suggesting that Fc receptor-mediated signaling
may be needed for phagocytosis. These studies indicate that FHA mediates
attachment of B. pertussis to neutrophils, but adenylate cyclase toxin blocks
phagocytosis.
PMID- 10679001
TI - Lipopolysaccharides of Brucella abortus and Brucella melitensis induce nitric
oxide synthesis in rat peritoneal macrophages.
AB - Smooth lipopolysaccharide (S-LPS) and lipid A of Brucella abortus and Brucella
melitensis induced the production of nitric oxide (NO) by rat adherent peritoneal
cells, but they induced lower levels of production of NO than Escherichia coli
LPS. The participation of the inducible isoform of NO synthase (iNOS) was
confirmed by the finding of an increased expression of both iNOS mRNA and iNOS
protein. These observations might help to explain (i) the acute outcome of
Brucella infection in rodents, (ii) the low frequency of septic shock in human
brucellosis, and (iii) the prolonged intracellular survival of Brucella in
humans.
PMID- 10679002
TI - Polymorphonuclear neutrophils are necessary for the recruitment of CD8(+) T cells
in the liver in a pregnant mouse model of Chlamydophila abortus (Chlamydia
psittaci serotype 1) infection.
AB - The role of polymorphonuclear neutrophils (PMNs) in the development of the
specific immune response against Chlamydophila abortus (Chlamydia psittaci
serotype 1) infection was studied in a pregnant mouse model involving treatment
with RB6-8C5 monoclonal antibody. PMN depletion significantly affected the immune
response in the liver, in which the T-lymphocyte and F4/80(+) cell populations
decreased, particularly the CD8(+) T-cell population. A Th1-like response,
characterized by high levels of gamma interferon without detectable levels of
interleukin 4 (IL-4) in serum, was observed in both depleted and nondepleted
mice, although an increased production of IL-10 was detected in the depleted
group. Our results suggest that PMNs play a very important role in the
recruitment of other leukocyte populations to the inflammatory foci but have
little influence in the polarization of the immune specific response toward a Th1
like response.
PMID- 10679003
TI - Quantitative imaging of pre-mRNA splicing factors in living cells.
PMID- 10679004
TI - Reconstitution of ATP-dependent movement of endocytic vesicles along microtubules
in vitro: an oscillatory bidirectional process.
AB - We have previously used the asialoglycoprotein receptor system to elucidate the
pathway of hepatocytic processing of ligands such as asialoorosomucoid (ASOR).
These studies suggested that endocytic vesicles bind to and travel along
microtubules under the control of molecular motors such as cytoplasmic dynein. We
now report reconstitution of this process in vitro with the use of a microscope
assay to observe the interaction of early endocytic vesicles containing
fluorescent ASOR with fluorescent microtubules. We find that ASOR-containing
endosomes bind to microtubules and translocate along them in the presence of ATP.
This represents the first time that mammalian endosomes containing a well
characterized ligand have been directly observed to translocate on microtubules
in vitro. The endosome movement does not require cytosol or exogenous motor
protein, is oscillatory, and is directed toward the plus and minus ends at equal
frequencies. We also observe endosomes being stretched in opposite directions
along microtubules, suggesting that microtubules could provide a mechanical basis
for endocytic sorting events. The movement of endosomes in vitro is consistent
with the hypothesis that microtubules actively participate in the sorting and
distribution of endocytic contents.
PMID- 10679005
TI - Sbe2p and sbe22p, two homologous Golgi proteins involved in yeast cell wall
formation.
AB - The cell wall of fungal cells is important for cell integrity and cell
morphogenesis and protects against harmful environmental conditions. The yeast
cell wall is a complex structure consisting mainly of mannoproteins, glucan, and
chitin. The molecular mechanisms by which the cell wall components are
synthesized and transported to the cell surface are poorly understood. We have
identified and characterized two homologous yeast proteins, Sbe2p and Sbe22p,
through their suppression of a chs5 spa2 mutant strain defective in chitin
synthesis and cell morphogenesis. Although sbe2 and sbe22 null mutants are
viable, sbe2 sbe22 cells display several phenotypes indicative of defects in cell
integrity and cell wall structure. First, sbe2 sbe22 cells display a sorbitol
remediable lysis defect at 37 degrees C and are hypersensitive to SDS and
calcofluor. Second, electron microscopic analysis reveals that sbe2 sbe22 cells
have an aberrant cell wall structure with a reduced mannoprotein layer. Finally,
immunofluorescence experiments reveal that in small-budded cells, sbe2 sbe22
mutants mislocalize Chs3p, a protein involved in chitin synthesis. In addition,
sbe2 sbe22 diploids have a bud-site selection defect, displaying a random budding
pattern. A Sbe2p-GFP fusion protein localizes to cytoplasmic patches, and Sbe2p
cofractionates with Golgi proteins. Deletion of CHS5, which encodes a Golgi
protein involved in the transport of Chs3p to the cell periphery, is lethal in
combination with disruption of SBE2 and SBE22. Thus, we suggest a model in which
Sbe2p and Sbe22p are involved in the transport of cell wall components from the
Golgi apparatus to the cell surface periphery in a pathway independent of Chs5p.
PMID- 10679006
TI - beta1 integrins regulate keratinocyte adhesion and differentiation by distinct
mechanisms.
AB - In keratinocytes, the beta1 integrins mediate adhesion to the extracellular
matrix and also regulate the initiation of terminal differentiation. To explore
the relationship between these functions, we stably infected primary human
epidermal keratinocytes and an undifferentiated squamous cell carcinoma line,
SCC4, with retroviruses encoding wild-type and mutant chick beta1 integrin
subunits. We examined the ability of adhesion-blocking chick beta1-specific
antibodies to inhibit suspension-induced terminal differentiation of primary
human keratinocytes and the ability of the chick beta1 subunit to promote
spontaneous differentiation of SCC4. A D154A point mutant clustered in focal
adhesions but was inactive in the differentiation assays, showing that
differentiation regulation required a functional ligand-binding domain. The
signal transduced by beta1 integrins in normal keratinocytes was "do not
differentiate" (transduced by ligand-occupied receptors) as opposed to "do
differentiate" (transduced by unoccupied receptors), and the signal depended on
the absolute number, rather than on the proportion, of occupied receptors. Single
and double point mutations in cyto-2 and -3, the NPXY motifs, prevented focal
adhesion targeting without inhibiting differentiation control. However, deletions
in the proximal part of the cytoplasmic domain, affecting cyto-1, abolished the
differentiation-regulatory ability of the beta1 subunit. We conclude that
distinct signaling pathways are involved in beta1 integrin-mediated adhesion and
differentiation control in keratinocytes.
PMID- 10679007
TI - Rab7: a key to lysosome biogenesis.
AB - The molecular machinery behind lysosome biogenesis and the maintenance of the
perinuclear aggregate of late endocytic structures is not well understood. A
likely candidate for being part of this machinery is the small GTPase Rab7, but
it is unclear whether this protein is associated with lysosomes or plays any role
in the regulation of the perinuclear lysosome compartment. Previously, Rab7 has
mainly been implicated in transport from early to late endosomes. We have now
used a new approach to analyze the role of Rab7: transient expression of Enhanced
Green Fluorescent Protein (EGFP)-tagged Rab7 wt and mutant proteins in HeLa
cells. EGFP-Rab7 wt was associated with late endocytic structures, mainly
lysosomes, which aggregated and fused in the perinuclear region. The size of the
individual lysosomes as well as the degree of perinuclear aggregation increased
with the expression levels of EGFP-Rab7 wt and, more dramatically, the active
EGFP-Rab7Q67L mutant. In contrast, upon expression of the dominant-negative
mutants EGFP-Rab7T22N and EGFP-Rab7N125I, which localized mainly to the cytosol,
the perinuclear lysosome aggregate disappeared and lysosomes, identified by
colocalization of cathepsin D and lysosome-associated membrane protein-1, became
dispersed throughout the cytoplasm, they were inaccessible to endocytosed
molecules such as low-density lipoprotein, and their acidity was strongly
reduced, as determined by decreased accumulation of the acidotropic probe
LysoTracker Red. In contrast, early endosomes associated with Rab5 and the
transferrin receptor, late endosomes enriched in the cation-independent mannose 6
phosphate receptor, and the trans-Golgi network, identified by its enrichment in
TGN-38, were unchanged. These data demonstrate for the first time that Rab7,
controlling aggregation and fusion of late endocytic structures/lysosomes, is
essential for maintenance of the perinuclear lysosome compartment.
PMID- 10679008
TI - Role for dynamin in late endosome dynamics and trafficking of the cation
independent mannose 6-phosphate receptor.
AB - It is well established that dynamin is involved in clathrin-dependent
endocytosis, but relatively little is known about possible intracellular
functions of this GTPase. Using confocal imaging, we found that endogenous
dynamin was associated with the plasma membrane, the trans-Golgi network, and a
perinuclear cluster of cation-independent mannose 6-phosphate receptor (CI-MPR)
containing structures. By electron microscopy (EM), it was shown that these
structures were late endosomes and that the endogenous dynamin was preferentially
localized to tubulo-vesicular appendices on these late endosomes. Upon induction
of the dominant-negative dynK44A mutant, confocal microscopy demonstrated a
redistribution of the CI-MPR in mutant-expressing cells. Quantitative EM analysis
of the ratio of CI-MPR to lysosome-associated membrane protein-1 in endosome
profiles revealed a higher colocalization of the two markers in dynK44A
expressing cells than in control cells. Western blot analysis showed that dynK44A
expressing cells had an increased cellular procathepsin D content. Finally, EM
revealed that in dynK44A-expressing cells, endosomal tubules containing CI-MPR
were formed. These results are in contrast to recent reports that dynamin-2 is
exclusively associated with endocytic structures at the plasma membrane. They
suggest instead that endogenous dynamin also plays an important role in the
molecular machinery behind the recycling of the CI-MPR from endosomes to the
trans-Golgi network, and we propose that dynamin is required for the final
scission of vesicles budding from endosome tubules.
PMID- 10679009
TI - Nuclear pre-mRNA compartmentalization: trafficking of released transcripts to
splicing factor reservoirs.
AB - In the present study, the spatial organization of intron-containing pre-mRNAs of
Epstein-Barr virus (EBV) genes relative to location of splicing factors is
investigated. The intranuclear position of transcriptionally active EBV genes, as
well as of nascent transcripts, is found to be random with respect to the
speckled accumulations of splicing factors (SC35 domains) in Namalwa cells,
arguing against the concept of the locus-specific organization of mRNA genes with
respect to the speckles. Microclusters of splicing factors are, however,
frequently superimposed on nascent transcript sites. The transcript environment
is a dynamic structure consisting of both nascent and released transcripts, i.e.,
the track-like transcript environment. Both EBV sequences of the chromosome 1
homologue are usually associated with the track, are transcriptionally active,
and exhibit in most cases a polar orientation. In contrast to nascent transcripts
(in the form of spots), the association of a post-transcriptional pool of viral
pre-mRNA (in the form of tracks) with speckles is not random and is further
enhanced in transcriptionally silent cells when splicing factors are sequestered
in enlarged accumulations. The transcript environment reflects the intranuclear
transport of RNA from the sites of transcription to SC35 domains, as shown by
concomitant mapping of DNA, RNA, and splicing factors. No clear vectorial
intranuclear trafficking of transcripts from the site of synthesis toward the
nuclear envelope for export into the cytoplasm is observed. Using Namalwa and
Raji cell lines, a correlation between the level of viral gene transcription and
splicing factor accumulation within the viral transcript environment has been
observed. This supports a concept that the level of transcription can alter the
spatial relationship among intron-containing genes, their transcripts, and
speckles attributable to various levels of splicing factors recruited from
splicing factor reservoirs. Electron microscopic in situ hybridization studies
reveal that the released transcripts are directed toward reservoirs of splicing
factors organized in clusters of interchromatin granules. Our results point to
the bidirectional intranuclear movement of macromolecular complexes between
intron-containing genes and splicing factor reservoirs: the recruitment of
splicing factors to transcription sites and movement of released transcripts from
DNA loci to reservoirs of splicing factors.
PMID- 10679010
TI - Regulation of the vitellogenin receptor during Drosophila melanogaster oogenesis.
AB - In many insects, development of the oocyte arrests temporarily just before
vitellogenesis, the period when vitellogenins (yolk proteins) accumulate in the
oocyte. Following hormonal and environmental cues, development of the oocyte
resumes, and endocytosis of vitellogenins begins. An essential component of yolk
uptake is the vitellogenin receptor. In this report, we describe the ovarian
expression pattern and subcellular localization of the mRNA and protein encoded
by the Drosophila melanogaster vitellogenin receptor gene yolkless (yl). yl RNA
and protein are both expressed very early during the development of the oocyte,
long before vitellogenesis begins. RNA in situ hybridization and lacZ reporter
analyses show that yl RNA is synthesized by the germ line nurse cells and then
transported to the oocyte. Yl protein is evenly distributed throughout the oocyte
during the previtellogenic stages of oogenesis, demonstrating that the failure to
take up yolk in these early stage oocyte is not due to the absence of the
receptor. The transition to the vitellogenic stages is marked by the accumulation
of yolk via clathrin-coated vesicles. After this transition, yolk protein
receptor levels increase markedly at the cortex of the egg. Consistent with its
role in yolk uptake, immunogold labeling of the receptor reveals Yl in endocytic
structures at the cortex of wild-type vitellogenic oocytes. In addition, shortly
after the inception of yolk uptake, we find multivesicular bodies where the yolk
and receptor are distinctly partitioned. By the end of vitellogenesis, the
receptor localizes predominantly to the cortex of the oocyte. However, during
oogenesis in yl mutants that express full-length protein yet fail to incorporate
yolk proteins, the receptor remains evenly distributed throughout the oocyte.
PMID- 10679011
TI - Functional elements within the dynein microtubule-binding domain.
AB - Dynein interacts with microtubules through an ATP-sensitive linkage mapped to a
structurally complex region of the heavy chain following the fourth P-loop motif.
Virtually nothing is known regarding how binding affinity is achieved and
modulated during ATP hydrolysis. We have performed a detailed dissection of the
microtubule contact site, using fragment expression, alanine substitution, and
peptide competition. Our work identifies three clusters of amino acids important
for the physical contact with microtubules; two of these fall within a region
sharing sequence homology with MAP1B, the third in a region just downstream.
Amino acid substitutions within any one of these regions can eliminate or weaken
microtubule binding (KK3379, 80, E3385, K3387, K3397, KK3410,11, W3414, RKK3418
20, F3426, R3464, S3466, and K3467), suggesting that their activities are highly
coordinated. A peptide that actively displaces MAP1B from microtubules perturbs
dynein binding, supporting previous evidence for similar sites of interaction. We
have also identified four amino acids whose substitutions affect release of the
motor from the microtubule (E3413, R3444, E3460, and C3469). These suggest that
nucleotide-sensitive affinity may be locally controlled at the site of contact.
Our work is the first detailed description of dynein-tubulin interactions and
provides a framework for understanding how affinity is achieved and modulated.
PMID- 10679012
TI - Detergent-insoluble GPI-anchored proteins are apically sorted in fischer rat
thyroid cells, but interference with cholesterol or sphingolipids differentially
affects detergent insolubility and apical sorting.
AB - In contrast to Madin-Darby canine kidney cells, Fischer rat thyroid cells deliver
the majority of endogenous glycosylphosphatidyl inositol (GPI)-anchored proteins
to the basolateral surface. However, we report here that the GPI proteins
Placental Alkaline Phosphatase (PLAP) and Neurotrophin Receptor-Placental
Alkaline Phosphatase (NTR-PLAP) are apically localized in transfected Fischer rat
thyroid cells. In agreement with the "raft hypothesis," which postulates the
incorporation of GPI proteins into glycosphingolipids and cholesterol-enriched
rafts, we found that both of these proteins were insoluble in Triton X-100 and
floated into the lighter fractions of sucrose density gradients. However,
disruption of lipid rafts by removal of cholesterol did not cause surface
missorting of PLAP and NTR-PLAP, and the altered surface sorting of these
proteins after Fumonisin B1 treatment did not correlate with reduced levels in
Triton X-100 -insoluble fractions. Furthermore, in contrast to the GPI-anchored
forms of both of these proteins, the secretory and transmembrane forms (in the
absence of a basolateral cytoplasmic signal) were sorted to the apical surface
without association with lipid microdomains. Together, these data demonstrate
that the GPI anchor is required to mediate raft association but is not sufficient
to determine apical sorting. They also suggest that signals present in the
ectodomain of the proteins play a major role and that lipid rafts may facilitate
the recognition of these signals in the trans-Golgi network, even though they are
not required for apical sorting.
PMID- 10679013
TI - The puc1 cyclin regulates the G1 phase of the fission yeast cell cycle in
response to cell size.
AB - Eukaryotic cells coordinate cell size with cell division by regulating the length
of the G1 and G2 phases of the cell cycle. In fission yeast, the length of the G1
phase depends on a precise balance between levels of positive (cig1, cig2, puc1,
and cdc13 cyclins) and negative (rum1 and ste9-APC) regulators of cdc2. Early in
G1, cyclin proteolysis and rum1 inhibition keep the cdc2/cyclin complexes
inactive. At the end of G1, the balance is reversed and cdc2/cyclin activity down
regulates both rum1 and the cyclin-degrading activity of the APC. Here we present
data showing that the puc1 cyclin, a close relative of the Cln cyclins in budding
yeast, plays an important role in regulating the length of G1. Fission yeast
cells lacking cig1 and cig2 have a cell cycle distribution similar to that of
wild-type cells, with a short G1 and a long G2. However, when the puc1(+) gene is
deleted in this genetic background, the length of G1 is extended and these cells
undergo S phase with a greater cell size than wild-type cells. This G1 delay is
completely abolished in cells lacking rum1. Cdc2/puc1 function may be important
to down-regulate the rum1 Cdk inhibitor at the end of G1.
PMID- 10679014
TI - Characterization of a bone morphogenetic protein-responsive Smad-binding element.
AB - Bone morphogenetic proteins (BMPs) are pleiotropic growth and differentiation
factors belonging to the transforming growth factor-beta (TGF-beta) superfamily.
Signals of the TGF-beta-like ligands are propagated to the nucleus through
specific interaction of transmembrane serine/threonine kinase receptors and Smad
proteins. GCCGnCGC has been suggested as a consensus binding sequence for
Drosophila Mad regulated by a BMP-like ligand, Decapentaplegic. Smad1 is one of
the mammalian Smads activated by BMPs. Here we show that Smad1 binds to this
motif upon BMP stimulation in the presence of the common Smad, Smad4. The binding
affinity is likely to be relatively low, because Smad1 binds to three copies of
the motif weakly, but more repeats of the motif significantly enhance the
binding. Heterologous reporter genes (GCCG-Lux) with multiple repeats of the
motif respond to BMP stimulation but not to TGF-beta or activin. Mutational
analyses reveal several bases critical for the responsiveness. A natural BMP
responsive reporter, pTlx-Lux, is activated by BMP receptors in P19 cells but not
in mink lung cells. In contrast, GCCG-Lux responds to BMP stimulation in both
cells, suggesting that it is a universal reporter that directly detects Smad
phosphorylation by BMP receptors.
PMID- 10679015
TI - Conserved composition of mammalian box H/ACA and box C/D small nucleolar
ribonucleoprotein particles and their interaction with the common factor Nopp140.
AB - Small nucleolar ribonucleoprotein particles (snoRNPs) mainly catalyze the
modification of rRNA. The two major classes of snoRNPs, box H/ACA and box C/D,
function in the pseudouridylation and 2'-O-methylation, respectively, of specific
nucleotides. The emerging view based on studies in yeast is that each class of
snoRNPs is composed of a unique set of proteins. Here we present a
characterization of mammalian snoRNPs. We show that the previously characterized
NAP57 is specific for box H/ACA snoRNPs, whereas the newly identified NAP65, the
rat homologue of yeast Nop5/58p, is a component of the box C/D class. Using
coimmunoprecipitation experiments, we show that the nucleolar and coiled-body
protein Nopp140 interacts with both classes of snoRNPs. This interaction is
corroborated in vivo by the exclusive depletion of snoRNP proteins from nucleoli
in cells transfected with a dominant negative Nopp140 construct. Interestingly,
RNA polymerase I transcription is arrested in nucleoli depleted of snoRNPs,
raising the possibility of a feedback mechanism between rRNA modification and
transcription. Moreover, the Nopp140-snoRNP interaction appears to be conserved
in yeast, because depletion of Srp40p, the yeast Nopp140 homologue, in a
conditional lethal strain induces the loss of box H/ACA small nucleolar RNAs. We
propose that Nopp140 functions as a chaperone of snoRNPs in yeast and vertebrate
cells.
PMID- 10679016
TI - An endosome-to-plasma membrane pathway involved in trafficking of a mutant plasma
membrane ATPase in yeast.
AB - The plasma membrane ATPase, encoded by PMA1, is delivered to the cell surface via
the secretory pathway. Previously, we characterized a temperature-sensitive pma1
mutant in which newly synthesized Pma1-7 is not delivered to the plasma membrane
but is mislocalized instead to the vacuole at 37 degrees C. Several vps mutants,
which are defective in vacuolar protein sorting, suppress targeting-defective
pma1 by allowing mutant Pma1 to move once again to the plasma membrane. In this
study, we have analyzed trafficking in the endosomal system by monitoring the
movement of Pma1-7 in vps36, vps1, and vps8 mutants. Upon induction of
expression, mutant Pma1 accumulates in the prevacuolar compartment in vps36
cells. After chase, a fraction of newly synthesized Pma1-7 is delivered to the
plasma membrane. In both vps1 and vps8 cells, newly synthesized mutant Pma1
appears in small punctate structures before arrival at the cell surface.
Nevertheless, biosynthetic membrane traffic appears to follow different routes in
vps8 and vps1: the vacuolar protein-sorting receptor Vps10p is stable in vps8 but
not in vps1. Furthermore, a defect in endocytic delivery to the vacuole was
revealed in vps8 (and vps36) but not vps1 by endocytosis of the bulk membrane
marker FM 4-64. Moreover, in vps8 cells, there is defective down-regulation from
the cell surface of the mating receptor Ste3, consistent with persistent receptor
recycling from an endosomal compartment to the plasma membrane. These data
support a model in which mutant Pma1 is diverted from the Golgi to the surface in
vps1 cells. We hypothesize that in vps8 and vps36, in contrast to vps1, mutant
Pma1 moves to the surface via endosomal intermediates, implicating an endosome-to
surface traffic pathway.
PMID- 10679017
TI - Roles of Hof1p, Bni1p, Bnr1p, and myo1p in cytokinesis in Saccharomyces
cerevisiae.
AB - Cytokinesis in Saccharomyces cerevisiae occurs by the concerted action of the
actomyosin system and septum formation. Here we report on the roles of HOF1,
BNI1, and BNR1 in cytokinesis, focusing on Hof1p. Deletion of HOF1 causes a
temperature-sensitive defect in septum formation. A Hof1p ring forms on the
mother side of the bud neck in G2/M, followed by the formation of a daughter-side
ring. Around telophase, Hof1p is phosphorylated and the double rings merge into a
single ring that contracts slightly and may colocalize with the actomyosin
structure. Upon septum formation, Hof1p splits into two rings, disappearing upon
cell separation. Hof1p localization is dependent on septins but not Myo1p.
Synthetic lethality suggests that Bni1p and Myo1p belong to one functional
pathway, whereas Hof1p and Bnr1p belong to another. These results suggest that
Hof1p may function as an adapter linking the primary septum synthesis machinery
to the actomyosin system. The formation of the actomyosin ring is not affected by
bni1Delta, hof1Delta, or bnr1Delta. However, Myo1p contraction is affected by
bni1Delta but not by hof1Delta or bnr1Delta. In bni1Delta cells that lack the
actomyosin contraction, septum formation is often slow and asymmetric, suggesting
that actomyosin contraction may provide directionality for efficient septum
formation.
PMID- 10679018
TI - VPS21 controls entry of endocytosed and biosynthetic proteins into the yeast
prevacuolar compartment.
AB - Mutations in the VPS (vacuolar protein sorting) genes of Saccharomyces cerevisiae
have been used to define the trafficking steps that soluble vacuolar hydrolases
take en route from the late Golgi to the vacuole. The class D VPS genes include
VPS21, PEP12, and VPS45, which appear to encode components of a membrane fusion
complex involved in Golgi-to-endosome transport. Vps21p is a member of the Rab
family of small Ras-like GTPases and shows strong homology to the mammalian Rab5
protein, which is involved in endocytosis and the homotypic fusion of early
endosomes. Although Rab5 and Vps21p appear homologous at the sequence level, it
has not been clear if the functions of these two Rabs are similar. We find that
Vps21p is an endosomal protein that is involved in the delivery of vacuolar and
endocytosed proteins to the vacuole. Vacuolar and endocytosed proteins accumulate
in distinct transport intermediates in cells that lack Vps21p function.
Therefore, it appears that Vps21p is involved in two trafficking steps into the
prevacuolar/late endosomal compartment.
PMID- 10679019
TI - Occludin 1B, a variant of the tight junction protein occludin.
AB - Occludin and claudin are the major integral membrane components of the mammalian
tight junction. Although more than 11 distinct claudins have been identified,
only 1 occludin transcript has been reported thus far. Therefore, we searched by
reverse transcription-PCR for occludin-related sequences in Madin-Darby canine
kidney (MDCK) mRNA and identified a transcript encoding an alternatively spliced
form of occludin, designated occludin 1B. The occludin 1B transcript contained a
193-base pair insertion encoding a longer form of occludin with a unique N
terminal sequence of 56 amino acids. Analysis of the MDCK occludin gene revealed
an exon containing the 193-base pair sequence between the exons encoding the
original N terminus and the distal sequence, suggesting that occludin and
occludin 1B arise from alternative splicing of one transcript. To assess the
expression and distribution of occludin 1B, an antibody was raised against its
unique N-terminal domain. Immunolabeling of occludin 1B in MDCK cells revealed a
distribution indistinguishable from that of occludin. Furthermore, occludin 1B
staining at cell-to-cell contacts was also found in cultured T84 human colon
carcinoma cells and in frozen sections of mouse intestine. Immunoblots of various
mouse tissues revealed broad coexpression of occludin 1B with occludin. The wide
epithelial distribution and the conservation across species suggests a
potentially important role for occludin 1B in the structure and function of the
tight junction.
PMID- 10679020
TI - The role of the tethering proteins p115 and GM130 in transport through the Golgi
apparatus in vivo.
AB - Biochemical data have shown that COPI-coated vesicles are tethered to Golgi
membranes by a complex of at least three proteins: p115, giantin, and GM130. p115
binds to giantin on the vesicles and to GM130 on the membrane. We now examine the
function of this tethering complex in vivo. Microinjection of an N-terminal
peptide of GM130 or overexpression of GM130 lacking this N-terminal peptide
inhibits the binding of p115 to Golgi membranes. Electron microscopic analysis of
single microinjected cells shows that the number of COP-sized transport vesicles
in the Golgi region increases substantially, suggesting that transport vesicles
continue to bud but are less able to fuse. This was corroborated by quantitative
immunofluorescence analysis, which showed that the intracellular transport of the
VSV-G protein was significantly inhibited. Together, these data suggest that this
tethering complex increases the efficiency with which transport vesicles fuse
with their target membrane. They also provide support for a model of mitotic
Golgi fragmentation in which the tethering complex is disrupted by mitotic
phosphorylation of GM130.
PMID- 10679021
TI - The secretory pathway mediates localization of the cell polarity regulator
Aip3p/Bud6p.
AB - Aip3p/Bud6p is a regulator of cell and cytoskeletal polarity in Saccharomyces
cerevisiae that was previously identified as an actin-interacting protein. Actin
interacting protein 3 (Aip3p) localizes at the cell cortex where cytoskeleton
assembly must be achieved to execute polarized cell growth, and deletion of AIP3
causes gross defects in cell and cytoskeletal polarity. We have discovered that
Aip3p localization is mediated by the secretory pathway. Mutations in early- or
late-acting components of the secretory apparatus lead to Aip3p mislocalization.
Biochemical data show that a pool of Aip3p is associated with post-Golgi
secretory vesicles. An investigation of the sequences within Aip3p necessary for
Aip3p localization has identified a sequence within the N terminus of Aip3p that
is sufficient for directing Aip3p localization. Replacement of the N terminus of
Aip3p with a homologous region from a Schizosaccharomyces pombe protein allows
for normal Aip3p localization, indicating that the secretory pathway-mediated
Aip3p localization pathway is conserved. Delivery of Aip3p also requires the type
V myosin motor Myo2p and its regulatory light-chain calmodulin. These data
suggest that one function of calmodulin is to activate Myo2p's activity in the
secretory pathway; this function is likely the polarized movement of late
secretory vesicles and associated Aip3p on actin cables.
PMID- 10679022
TI - Essential functions of protein tyrosine phosphatases PTP2 and PTP3 and RIM11
tyrosine phosphorylation in Saccharomyces cerevisiae meiosis and sporulation.
AB - Tyrosine phosphorylation plays a central role in eukaryotic signal transduction.
In yeast, MAP kinase pathways are regulated by tyrosine phosphorylation, and it
has been speculated that other biochemical processes may also be regulated by
tyrosine phosphorylation. Previous genetic and biochemical studies demonstrate
that protein tyrosine phosphatases (PTPases) negatively regulate yeast MAP
kinases. Here we report that deletion of PTP2 and PTP3 results in a sporulation
defect, suggesting that tyrosine phosphorylation is involved in regulation of
meiosis and sporulation. Deletion of PTP2 and PTP3 blocks cells at an early stage
of sporulation before premeiotic DNA synthesis and induction of meiotic-specific
genes. We observed that tyrosine phosphorylation of several proteins, including
52-, 43-, and 42-kDa proteins, was changed in ptp2Deltaptp3Delta homozygous
deletion cells under sporulation conditions. The 42-kDa tyrosine-phosphorylated
protein was identified as Mck1, which is a member of the GSK3 family of protein
kinases and previously known to be phosphorylated on tyrosine. Mutation of MCK1
decreases sporulation efficiency, whereas mutation of RIM11, another GSK3 member,
specifically abolishes sporulation; therefore, we investigated regulation of
Rim11 by Tyr phosphorylation during sporulation. We demonstrated that Rim11 is
phosphorylated on Tyr-199, and the Tyr phosphorylation is essential for its in
vivo function, although Rim11 appears not to be directly regulated by Ptp2 and
Ptp3. Biochemical characterizations indicate that tyrosine phosphorylation of
Rim11 is essential for the activity of Rim11 to phosphorylate substrates. Our
data demonstrate important roles of protein tyrosine phosphorylation in meiosis
and sporulation
PMID- 10679023
TI - Effects of I domain deletion on the function of the beta2 integrin lymphocyte
function-associated antigen-1.
AB - A subset of integrin alpha subunits contain an I domain, which is important for
ligand binding. We have deleted the I domain from the beta2 integrin lymphocyte
function-asssociated antigen-1 (LFA-1) and expressed the resulting non-I domain
containing integrin (DeltaI-LFA-1) in an LFA-1-deficient T cell line. DeltaI-LFA
1 showed no recognition of LFA-1 ligands, confirming the essential role of the I
domain in ligand binding. Except for I domain monoclonal antibodies (mAbs),
DeltaI-LFA-1 was recognized by a panel of anti-LFA-1 mAbs similarly to wild-type
LFA-1. However, DeltaI-LFA-1 had enhanced expression of seven mAb epitopes that
are associated with beta2 integrin activation, suggesting that it exhibited an
"active" conformation. In keeping with this characteristic, DeltaI-LFA-1 induced
constitutive activation of alpha4beta1 and alpha5beta1, suggesting intracellular
signaling to these integrins. This "cross-talk" was not due to an effect on beta1
integrin affinity. However, the enhanced activity was susceptible to inhibition
by cytochalasin D, indicating a role for the cytoskeleton, and also correlated
with clustering of beta1 integrins. Thus, removal of the I domain from LFA-1
created an integrin with the hallmarks of a constitutively active receptor
mediating signals into the cell. These findings suggest a key role for the I
domain in controlling integrin activity.
PMID- 10679024
TI - The yeast kinesin-related protein Smy1p exerts its effects on the class V myosin
Myo2p via a physical interaction.
AB - We have discovered evidence for a physical interaction between a class V myosin,
Myo2p, and a kinesin-related protein, Smy1p, in budding yeast. These proteins had
previously been linked by genetic and colocalization studies, but we had been
unable to determine the nature of their association. We now show by two-hybrid
analysis that a 69-amino acid region of the Smy1p tail interacts with the
globular portion of the Myo2p tail. Deletion of this myosin-binding region of
Smy1p eliminates its ability to colocalize with Myo2p and to overcome the myo2-66
mutant defects, suggesting that the interaction is necessary for these functions.
Further insights about the Smy1p-Myo2p interaction have come from studies of a
new mutant allele, myo2-2, which causes a loss of Myo2p localization. We report
that Smy1p localization is also lost in the myo2-2 mutant, demonstrating that
Smy1p localization is dependent on Myo2p. We also found that overexpression of
Smy1p partially restores myo2-2p localization in a myosin-binding region
dependent manner. Thus, overexpression of Smy1p can overcome defects in both the
head and tail domains of Myo2p (caused by the myo2-66 and myo2-2 alleles,
respectively). We propose that Smy1p enhances some aspect of Myo2p function,
perhaps delivery or docking of vesicles at the bud tip.
PMID- 10679025
TI - Monoclonal antibodies to NTF2 inhibit nuclear protein import by preventing
nuclear translocation of the GTPase Ran.
AB - Nuclear transport factor 2 (NTF2) is a soluble transport protein originally
identified by its ability to stimulate nuclear localization signal (NLS)
dependent protein import in digitonin-permeabilized cells. NTF2 has been shown to
bind nuclear pore complex proteins and the GDP form of Ran in vitro. Recently, it
has been reported that NTF2 can stimulate the accumulation of Ran in digitonin
permeabilized cells. Evidence that NTF2 directly mediates Ran import or that NTF2
is required to maintain the nuclear concentration of Ran in living cells has not
been obtained. Here we show that cytoplasmic injection of anti-NTF2 mAbs resulted
in a dramatic relocalization of Ran to the cytoplasm. This provides the first
evidence that NTF2 regulates the distribution of Ran in vivo. Moreover, anti-NTF2
mAbs inhibited nuclear import of both Ran and NLS-containing protein in vitro,
suggesting that NTF2 stimulates NLS-dependent protein import by driving the
nuclear accumulation of Ran. We also show that biotinylated NTF2-streptavidin
microinjected into the cytoplasm accumulated at the nuclear envelope, indicating
that NTF2 can target a binding partner to the nuclear pore complex. Taken
together, our data show that NTF2 is an essential regulator of the Ran
distribution in living cells and that NTF2-mediated Ran nuclear import is
required for NLS-dependent protein import.
PMID- 10679026
TI - Palmitoylation of apolipoprotein B is required for proper intracellular sorting
and transport of cholesteroyl esters and triglycerides.
AB - Apolipoprotein B (apoB) is an essential component of chylomicrons, very low
density lipoproteins, and low density lipoproteins. ApoB is a palmitoylated
protein. To investigate the role of palmitoylation in lipoprotein function, a
palmitoylation site was mapped to Cys-1085 and removed by mutagenesis. Secreted
lipoprotein particles formed by nonpalmitoylated apoB were smaller and denser and
failed to assemble a proper hydrophobic core. Indeed, the relative concentrations
of nonpolar lipids were three to four times lower in lipoprotein particles
containing mutant apoB compared with those containing wild-type apoB, whereas
levels of polar lipids isolated from wild-type or mutant apoB lipoprotein
particles appeared identical. Palmitoylation localized apoB to large vesicular
structures corresponding to a subcompartment of the endoplasmic reticulum, where
addition of neutral lipids was postulated to occur. In contrast, nonpalmitoylated
apoB was concentrated in a dense perinuclear area corresponding to the Golgi
compartment. The involvement of palmitoylation as a structural requirement for
proper assembly of the hydrophobic core of the lipoprotein particle and its
intracellular sorting represent novel roles for this posttranslational
modification.
PMID- 10679027
TI - Association of insulin receptor substrate proteins with Bcl-2 and their effects
on its phosphorylation and antiapoptotic function.
AB - Insulin receptor substrate (IRS) proteins are docking proteins that couple growth
factor receptors to various effector molecules, including phosphoinositide-3
kinase, Grb-2, Syp, and Nck. Here we show that IRS-1 associates with the loop
domain of Bcl-2 and synergistically up-regulates antiapoptotic function of Bcl-2.
IRS-2 but not IRS-3 binds to Bcl-2, and IRS-1 associates with Bcl-XL but not with
Bax or Bik. Overexpression of IRS-1 suppresses phosphorylation of Bcl-2 induced
by stimulation with insulin, and the hypophosphorylation may lead to its enhanced
antiapoptotic activity. The binding site for Bcl-2 is located on the carboxyl
half-domain of IRS-1. IRS-3, which lacks the corresponding region, dominant
negatively abrogates the survival effects of IRS-1 and Bcl-2. For the
antiapoptotic activity of IRS-1, binding to Bcl-2 is more critical than
activating phosphoinositide-3 kinase. Our results indicate that IRS proteins
transmit signals from the insulin receptor to Bcl-2, thus regulating cell
survival probably through regulating phosphorylation of Bcl-2.
PMID- 10679028
TI - The mouse SKD1, a homologue of yeast Vps4p, is required for normal endosomal
trafficking and morphology in mammalian cells.
AB - The mouse SKD1 is an AAA-type ATPase homologous to the yeast Vps4p implicated in
transport from endosomes to the vacuole. To elucidate a possible role of SKD1 in
mammalian endocytosis, we generated a mutant SKD1, harboring a mutation (E235Q)
that is equivalent to the dominant negative mutation (E233Q) in Vps4p.
Overexpression of the mutant SKD1 in cultured mammalian cells caused defect in
uptake of transferrin and low-density lipoprotein. This was due to loss of their
receptors from the cell surface. The decrease of the surface transferrin receptor
(TfR) was correlated with expression levels of the mutant protein. The mutant
protein displayed a perinuclear punctate distribution in contrast to a diffuse
pattern of the wild-type SKD1. TfR, the lysosomal protein lamp-1, endocytosed
dextran, and epidermal growth factor but not markers for the secretory pathway
were accumulated in the mutant SKD1-localized compartments. Degradation of
epidermal growth factor was inhibited. Electron microscopy revealed that the
compartments were exaggerated multivesicular vacuoles with numerous tubulo
vesicular extensions containing TfR and endocytosed horseradish peroxidase. The
early endosome antigen EEA1 was also redistributed to these aberrant membranes.
Taken together, our findings suggest that SKD1 regulates morphology of endosomes
and membrane traffic through them.
PMID- 10679029
TI - Role of ribosome and translocon complex during folding of influenza hemagglutinin
in the endoplasmic reticulum of living cells.
AB - Protein folding in the living cell begins cotranslationally. To analyze how it is
influenced by the ribosome and by the translocon complex during translocation
into the endoplasmic reticulum, we expressed a mutant influenza hemagglutinin (a
type I membrane glycoprotein) with a C-terminal extension. Analysis of the
nascent chains by two-dimensional SDS-PAGE showed that ribosome attachment as
such had little effect on ectodomain folding or trimer assembly. However, as long
as the chains were ribosome bound and inside the translocon complex, formation of
disulfides was partially suppressed, trimerization was inhibited, and the protein
protected against aggregation.
PMID- 10679031
TI - Progressive familial intrahepatic cholestasis: a personal perspective.
AB - Progressive familial intrahepatic cholestasis (PFIC), originally described as
"Byler disease" in an Amish kindred, has been distinguished from other forms of
cholestatic liver disease in childhood by clinical findings, clinical-laboratory
observations, and morphologic studies in biopsy, hepatectomy, and autopsy
specimens. Correlation with genetic analyses has permitted both more precise
definition of PFIC and distinctions within PFIC. Two types of PFIC now are
recognized: PFIC-1, resulting from mutations in a gene called FIC1 (familial
intrahepatic cholestasis, type 1), and PFIC-2, resulting from mutations in a gene
called BSEP (bile salt export pump). Other forms of PFIC may yet be identified.
The roles of FIC1 and BSEP in the secretion of bile acids into bile and in the
post-secretory modification of bile are under study.
PMID- 10679032
TI - Definitive classes of childhood supratentorial neuroglial tumors. The Childhood
Brain Tumor Consortium.
AB - Our objective in this study was to identify histologically homogenous classes of
childhood supratentorial neuroglial tumors. Previously, we identified five
quantitative histologic factors (differing linear combinations of 17 reliably
recognized histologic features in neuroglial tumors). They account for much of
the histologic variance in the 703 supratentorial tumors in the Childhood Brain
Tumor Consortium (CBTC) database. In this study, we used the scores on the
factors in cluster analyses and identified eight classes of neuroglial tumors.
Each of these classes had significant differences in histology, allowing the
separation of many of the conventional types of neuroglial tumors into two or
more classes. For instance, fibrillary astrocytoma, pilocytic astrocytoma,
subependymal giant cell astrocytoma, anaplastic astrocytoma, oligodendroglioma,
and ependymoma were represented in two or more classes. Often these classes had
statistically significant differences in survival distributions. For instance,
the two classes of "anaplastic astrocytomas" have widely discrepant 5-year
survival probabilities of 0.7 and 0.2. Use of the classes identified in this
study ensures relatively homogeneous histologic subsets of tumors. We suggest
that these classes will be useful for the selection of children for therapeutic
clinical trials.
PMID- 10679030
TI - Identification of novel, evolutionarily conserved Cdc42p-interacting proteins and
of redundant pathways linking Cdc24p and Cdc42p to actin polarization in yeast.
AB - In the yeast Saccharomyces cerevisiae, Cdc24p functions at least in part as a
guanine-nucleotide-exchange factor for the Rho-family GTPase Cdc42p. A genetic
screen designed to identify possible additional targets of Cdc24p instead
identified two previously known genes, MSB1 and CLA4, and one novel gene,
designated MSB3, all of which appear to function in the Cdc24p-Cdc42p pathway.
Nonetheless, genetic evidence suggests that Cdc24p may have a function that is
distinct from its Cdc42p guanine-nucleotide-exchange factor activity; in
particular, overexpression of CDC42 in combination with MSB1 or a truncated CLA4
in cells depleted for Cdc24p allowed polarization of the actin cytoskeleton and
polarized cell growth, but not successful cell proliferation. MSB3 has a close
homologue (designated MSB4) and two more distant homologues (MDR1 and YPL249C) in
S. cerevisiae and also has homologues in Schizosaccharomyces pombe, Drosophila
(pollux), and humans (the oncogene tre17). Deletion of either MSB3 or MSB4 alone
did not produce any obvious phenotype, and the msb3 msb4 double mutant was
viable. However, the double mutant grew slowly and had a partial disorganization
of the actin cytoskeleton, but not of the septins, in a fraction of cells that
were larger and rounder than normal. Like Cdc42p, both Msb3p and Msb4p localized
to the presumptive bud site, the bud tip, and the mother-bud neck, and this
localization was Cdc42p dependent. Taken together, the data suggest that Msb3p
and Msb4p may function redundantly downstream of Cdc42p, specifically in a
pathway leading to actin organization. From previous work, the BNI1, GIC1, and
GIC2 gene products also appear to be involved in linking Cdc42p to the actin
cytoskeleton. Synthetic lethality and multicopy suppression analyses among these
genes, MSB, and MSB4, suggest that the linkage is accomplished by two parallel
pathways, one involving Msb3p, Msb4p, and Bni1p, and the other involving Gic1p
and Gic2p. The former pathway appears to be more important in diploids and at low
temperatures, whereas the latter pathway appears to be more important in haploids
and at high temperatures.
PMID- 10679033
TI - Congenitally malformed hearts from a population of children undergoing cardiac
transplantation: comments on sequential segmental analysis and dissection.
AB - Our aim is to examine the types of cardiac malformations found in a population of
children undergoing cardiac transplantation, and to discuss a method for
examining cardiac explants based on intrinsic morphology. We describe in detail
the congenital malformations found in 65 cardiac explants acquired from a
population of children over a period of 15 years. The specimens were examined and
diagnosed using the method of sequential segmental analysis. The most prevalent
type of cardiac malformation was severe obstruction of the left heart (29. 2%),
followed by double-outlet right ventricle (15.4%), complete transposition
(13.8%), hearts with left-hand ventricular topology (10.8%), ventricular septal
defect(s) (9.2%), tricuspid valvar agenesis (4.6%), and tetralogy of Fallot
(4.6%). These abnormalities accounted for 87.6% of the specimens studied. We also
cataloged the extracardiac malformations found at autopsy in those patients who
died despite the transplantation. Extracardiac malformations were identified in
10 of the 19 patients who came to autopsy. Three had heterotaxy syndrome with
isomerism of the atrial appendages, one with right and two with left isomerism.
Other anomalies included tracheoesophageal fistula, pulmonary sequestration,
extrahepatic biliary atresia, duodenal atresia, choanal atresia, and vascular
malformations.Our study shows that even the most complicated cardiac
malformations can readily be diagnosed in an explanted heart using the segmental
approach based on observed morphology.
PMID- 10679034
TI - Bannayan-Riley-Ruvalcaba syndrome: spectrum of intestinal pathology including
juvenile polyps.
AB - Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a disorder that includes juvenile
polyposis as part of its pathologic spectrum, and it recently has been shown to
share phenotypic and genotypic features with Cowden's disease. In existing
literature, descriptions of intestinal pathology in patients with BRRS are
relatively sparse and occasionally erroneous. We describe the intestinal
pathology in multiple specimens from three children with BRRS. Examination of
gastrointestinal biopsies from these children revealed predominantly colonic and
rectal polyps with the histology of juvenile polyps. Additionally, two cases with
clusters of ectopic ganglion cells within the lamina propria, one in a colonic
polyp and one in a duodenal biopsy, and an atypical polyp were observed. Bannayan
Riley-Ruvalcaba syndrome should be included in the list of differential
diagnostic considerations when a child or young adult presents with a juvenile
polyp, particularly if unusual histologic features such as atypical polyps or
ectopic ganglion cells are encountered.
PMID- 10679035
TI - Evaluation of a neuraminidase detection assay for the rapid detection of
influenza A and B virus in children.
AB - A prototype version of a new diagnostic assay for influenza A and B (Zstat
Flutrade mark) based on detection of viral neuraminidase was evaluated and
compared to culture in 196 clinical samples. Children with respiratory illnesses
were prospectively evaluated at a pediatrician's office and at a large children's
hospital using the neuraminidase assay and viral culture performed on respiratory
secretions. Influenza virus was isolated from 51 samples and 83 were positive by
the neuraminidase assay. When compared to culture the sensitivity of the assay
was 96%, specificity was 77%, positive predictive value was 59%, and negative
predictive value was 98%. Testing in the laboratory of pure cultures of bacteria
and non-influenza viruses frequently found in the respiratory tract showed 0%
cross-reactivity with the neuraminidase assay and 100% specificity for influenza
virus in vitro. This new assay provided useful information for the preliminary
diagnosis of influenza A and B infections and appears to be suitable for both
point-of-care use in the physician's office and rapid diagnosis in a virology
laboratory. The high sensitivity makes it particularly useful as a screening test
for exclusion of influenza A and B infections. To confirm the diagnosis and
exclude a false-positive result, as well as to determine the influenza virus
type, a viral culture may be considered.
PMID- 10679036
TI - Clinical and histopathological study of merosin-deficient and merosin-positive
congenital muscular dystrophy.
AB - The clinical features of merosin-positive congenital muscular dystrophy (CMD) and
merosin-deficient CMD are well known, with those of merosin-deficient CMD being
more severe. Whether the severity of histopathological findings correlates with
these clinical features remains unanswered. In this study, the clinical and
histopathological findings of 39 merosin-deficient and 37 merosin-positive CMD
patients were compared. Merosin-deficient CMD patients were found to be younger,
with earlier onset of symptoms, age of diagnosis, and a more severe clinical
state (reflecting maximum motor capacity and contractures). On histopathological
evaluation, endomysial fibrosis, perimysial fibrosis, and histopathological state
(reflecting fibrosis, adiposis, necrosis, and variation in fiber size) were more
severe in merosin-deficient CMD. There was a correlation between clinical and
histopathological states only in merosin-deficient CMD.
PMID- 10679037
TI - Significance of lymphoid follicles and aggregates in gastric mucosa of children.
AB - This study was designed to evaluate the significance of gastric lymphoid
follicles (LF) and aggregates (LA) in children with and without Helicobacter
pylori (HP) infection. All 605 antrum biopsies performed during 1994 were
reviewed and classified according to the presence or absence of inflammation, LF,
or LA. HP was searched with a DiffQuik stain in all biopsies showing gastritis,
LF, or LA. Gastritis was diagnosed in 80 biopsies (16 with LF, 18 with LA and 46
without LA or LF). Identification of HP in these biopsies was as follows: (a)
cases with LF: 12/16; (b) cases with LA: 3/18; (c) cases without LF or LA: 8/46.
The biopsies without gastritis had a higher frequency of LA (65/525) than of LF
(2/525). HP was not identified in any case without gastritis. The presence of LF
with histologic gastritis had the strongest correlation with HP (R = 0.5, p <
0.00001). LF with gastritis had a positive predictive value of 75% for HP and the
absence of LF had a negative predictive value of 82.8% (sensitivity 52%;
specificity 92%). LA with gastritis had no significant correlation with HP. From
these results we conclude that lymphoid follicles should be distinguished from
lymphoid aggregates. Lymphoid follicles can rarely be present in an otherwise
normal gastric mucosa; however, they are more frequently found in cases of
gastritis and are strongly associated with HP infection. Lymphoid aggregates are
not significantly associated with HP infection and may be a component of the
normal gastric lymphoid tissue.
PMID- 10679038
TI - Novel point mutation (W184R) in neonatal type 2 Gaucher disease.
AB - Gaucher disease is the most prevalent inherited sphingolipidosis and results from
deficient glucocerebrosidase activity. Three clinical forms of Gaucher disease
have been described: type 1, or non-neuronopathic; type 2, or acute
neuronopathic; and type 3, or subacute neuronopathic. We have identified a novel
mutation in a patient of Russian-British descent who died of type 2 Gaucher
disease a few hours after birth. A heterozygous T --> C transition mutation in
exon 6, cDNA nucleotide position 667, results in the substitution of tryptophan
by arginine at amino acid residue 184 (W184R) of glucocerebrosidase. This
mutation creates a new cleavage site for the restriction endonuclease Hinf1. We
developed a method that utilizes Hinf1 restriction endonuclease analysis to
confirm the presence of the mutation and test family members. The second mutation
identified in the other glucocerebrosidase allele of the patient is mutation
L444P, a severe mutation frequent in type 2 and 3 Gaucher disease. Since the
patient died very shortly after birth, we postulate that the W184R/L444P genotype
may result in little or no detectable glucocerebrosidase activity and thus a poor
prognosis.
PMID- 10679039
TI - Peripheral neuroblastic tumors: pathologic classification based on
recommendations of international neuroblastoma pathology committee (Modification
of shimada classification).
PMID- 10679041
TI - Twenty-One Years Old-Pediatric Cardiology Coming of Age.
PMID- 10679040
TI - Lysozyme immunostaining in renal tubular dysgenesis.
PMID- 10679044
TI - Inhibition of germ tube formation by Candida albicans by local anesthetics: an
effect related to ionic channel blockade.
AB - Formation of germ tubes by Candida albicans has been assumed as a putative
virulence factor. Local anesthetics (LAs), e.g., lidocaine and bupivacaine, are
known to inhibit germ tube formation. The study confirmed this observation for
the novel drug ropivacaine, although it was less potent than the former two
drugs. Hypothesizing that the effect is due to blockading ionic channels, we
exposed Candida albicans to selective calcium blockers, i.e., nifedipine and
verapamil, and to a general blocker of ionic channels, i.e., lanthanum. All
blockers inhibited germ tube formation. The effect was dose-dependent and pH
independent. Addition of calcium reverted the effect of the blockers as well as
the effect of lidocaine and ropivacaine. The study suggests that the inhibitory
effect of LAs on germ tube formation by C. albicans is due to blockade of ionic
channels, particularly calcium channels. Therefore, LAs can affect morphology and
probably also the pathogenesis of C. albicans.
PMID- 10679045
TI - Streptococcal opacity factor: a family of bifunctional proteins with
lipoproteinase and fibronectin-binding activities.
AB - The serum opacity factor (SOF) of Streptococcus pyogenes is a type-specific
lipoproteinase of unknown biological significance. We have sequenced the sof gene
and characterized the corresponding SOF protein from a strain of type M63. It was
found that sof63 is related to sof22 and that, similar to SOF22 [25], SOF63 binds
fibronectin. Moreover, we demonstrate opacity factor activity in a Streptococcus
dysgalactiae fibronectin-binding protein FnBA that is structurally related to the
SOF proteins of S. pyogenes. Sequence analysis of these three SOF proteins showed
a unique periodical pattern of conserved and variable regions. The enzymatically
active part of SOF63 was localized to the fragment corresponding to the entire
set of conserved and variable sequences, while for fibronectin-binding a single
repeat in the C terminal part of the protein was sufficient. The results show
that streptococcal SOF proteins form a novel family of bifunctional proteins with
lipoproteinase and fibronectin-binding activities.
PMID- 10679046
TI - Use of sequence-specific antisense oligodeoxynucleotides to determine the
protozoan parasite antigen recognized by nonspecific cytotoxic cells.
AB - The antigen on the protozoan parasite Tetrahymena pyriformis recognized by
catfish nonspecific cytotoxic cells (NCC) is a 46- to 48-kDa protein referred to
as NKTag. The complete cDNA-derived amino acid sequence of NKTag has been
obtained. The antigenic determinant of NKTag corresponding to the NCC binding
site has been determined with synthetic peptides in target cell competition
experiments. To more directly characterize the mechanism of parasite:effector
cell interaction, we applied NKTag sequence-specific antisense
oligodeoxynucleotides to Tetrahymena in vitro. NKTag mRNA translation by
Tetrahymena was blocked by specific antisense (AS) oligodeoxynucleotides. 5'-3'
sense (S) oligodeoxynucleotide sequences were synthesized corresponding to the
first 17 N-terminal amino acids of NKTag (in addition to -2 untranslated codons
plus the start codon). Complimentary AS oligodeoxynucleotides were likewise
synthesized. To determine the optimum in vitro conditions for AS treatment, we
tested parasites at various phases of their growth cycle for the effects of a
single AS treatment. At 9 h post-AS treatment (during the linear phase of the
growth curve), maximum reduction in membrane expression of NKTag was observed.
Eighty-five percent of Tetrahymena were positive for expression of NKTag at 0
time post-AS treatment versus 13% positive at 9 h. Membrane expression of AS
treated parasites returned to normal levels by 24 h post-treatment. In cold
target inhibition experiments, the reduced NKTag expression by Tetrahymena at 9 h
AS treatment was confirmed by observing a complete inability (compared with S
treated parasites) to compete with IM-9 cells for binding with NCC. These data
demonstrated a unique experimental in vitro system to define the antigen
determinant on target cells responsible for recognition by cytotoxic effector
cells that participate in innate immune responses.
PMID- 10679047
TI - Construction of a promoter-rescue plasmid for Butyrivibrio fibrisolvens and its
use in characterization of a flagellin promoter.
AB - The Butyrivibrio fibrisolvens/Escherichia coli shuttle vector pBHerm has been
modified to produce a plasmid (pBHE) that can be used for the identification and
characterization of promoters in B. fibrisolvens. pBHE allows the insertion of a
test promoter immediately upstream of a promoterless erythromycin resistance gene
(ermAM). The efficacy of the pBHE plasmid in isolating and characterizing
promoters was tested by inserting the flagellin gene (flaA) promoter from B.
fibrisolvens OR77. Transcription of the ermAM gene from the flaA promoter was
significantly higher than that observed when the ermAM gene was under the control
of its own promoter. The flagelling gene of OR77 appears to be transcribed from
two different promoters that produce transcripts initiating approximately 130 bp
apart. Two mutant flaA promoter constructs, containing mutations in the -10 and
35 regions of either of the two putative promoter regions, showed drastic
alterations in both the origin and amounts of the two transcripts produced.
Mutations in either promoter affected transcription from both promoters,
indicating that both regions contribute to gene expression.
PMID- 10679048
TI - Mcchs1, a member of a chitin synthase gene family in Mucor circinelloides, is
differentially expressed during dimorphism.
AB - A complete chitin synthase gene and one chitin synthase gene fragment of the
zygomycete Mucor circinelloides have been cloned and analyzed. Both genes encode
zymogenic Class II chitin synthases. Hybridization analysis showed that there
must exist at least another Class II chitin synthase gene in M. circinelloides
highly homologous to the cloned Mcchs1 and Mcchs2. The expression of these genes
during the dimorphic growing stages was analyzed. Northern hybridizations showed
that Mcchs1 transcript accumulates only during the exponentially growing hyphal
stage, while no expression could be detected in the yeast form. Expression of
Mcchs2 could not be detected at any stage. Accumulation of Mcchs1 transcript was
not influenced by visible light. The existence of a multigene chitin synthase
family and the observation that Mcchs1 transcription depends upon the dimorphic
stage indicate that various chitin synthase activities may have different roles
in the dimorphic growth of M. circinelloides.
PMID- 10679049
TI - The effect of a methanogen, Methanobrevibacter smithii, on the growth rate,
organic acid production, and specific ATP activity of three predominant ruminal
cellulolytic bacteria.
AB - Three predominant ruminal cellulolytic organisms, Fibrobacter succinogenes S85,
Ruminococcus albus 8, and R. flavefaciens FD-1, were cultured with a methanogen,
Methanobrevibacter smithii. Growth rates, bacterial protein, organic acids, and
methane production were measured. When grown in diculture with the methanogen, a
fermentative advantage was observed with F. succinogenes S85 as seen by an
increase in specific rate of ATP production and organic acid concentration. The
introduction of the methanogen did not improve the growth rate, organic acid
yield, or specific rate of ATP production for R. albus 8. The growth rate and
amount of organic acid end products increased when R. flavefaciens FD-1 was
cultured with the methanogen; however, the specific activity of ATP production
did not increase.
PMID- 10679050
TI - Purification and characterization of invertase from Lactobacillus reuteri CRL
1100.
AB - The invertase of Lactobacillus reuteri CRL 1100 is a glycoprotein composed by a
single subunit with a molecular weight of 58 kDa. The enzyme was stable below 45
degrees C over a wide pH range (4.5-7.0) with maximum activity at pH 6.0 and 37
degrees C. The invertase activity was significantly inhibited by bivalent metal
ions (Ca(++), Cu(++), Cd(++), and Hg(++)), beta-mercaptoethanol, and
dithiothreitol and partially improved by ethylenediaminetetraacetic acid. The
enzyme was purified 32 times over the crude extract by gel filtration and ion
exchange chromatography with a recovery of 17%. The K(m) and V(max) values for
sucrose were 6.66 mM and 0.028 micromol/min, respectively. An invertase is
purified and characterized for the first time in Lactobacillus, and it proved to
be a beta-fructofuranosidase.
PMID- 10679051
TI - Variations in the ability of ruminal gram-negative Prevotella species to resist
monensin.
AB - Gram-negative, ruminal Prevotella strains (n = 15) differed greatly in their
sensitivity to the feed additive monensin. Strains that were repeatedly
transferred with sublethal doses tolerated more monensin than those that were
unadapted, but growth experiments indicated that the sensitivity range was as
great as 2000-fold. Prevotella bryantii B(1)4 grew with monensin concentrations
as high as 20 microM, but P. ruminicola H15a, D31d, 20-63, E40a, and D42f never
initiated growth if monensin was greater than 0.01 microM. Washed cell
preparations that were energized with glucose lost intracellular potassium when
monensin was added, and potassium depletion could also be used as an index of
monensin sensitivity. Adapted cells of P. bryantii B(1)4 had a half-maximal
potassium depletion constant (K(d)) of 3.2 microM, but the K(d) values of P.
ruminicola strains H15a, D31d, 20-63, E40a, and D42f were less than 0.04 microM.
Maximal potassium depletion (K(max)) values range from 90% to 40%, and monensin
adapted cells always had lower K(max) values than unadapted cells. A linear
regression of log K(d)/K(max) versus percentage decrease in optical density
divided by monensin concentration had an r(2) of 0.75, and this regression
indicated that potassium depletion from washed cells closely correlated with
growth inhibition. P. bryantii B(1)4 had a K(d)/K(max) ratio that was sevenfold
greater than other Prevotella strains, and this result indicated that P. bryantii
may be unusual in its ability to grow with very high concentrations of monensin.
PMID- 10679052
TI - Formation of aniline as a transient metabolite during the metabolism of tetryl by
a sulfate-reducing bacterial consortium.
AB - A laboratory study was conducted to determine whether tetryl (2,4,6
trinitrophenylmethylnitramine) can be degraded by an anaerobic process. The
results indicated that the metabolic conversion of tetryl to aniline is possible
by a sulfate-reducing bacterial (SRB) consortium. This SRB consortium metabolized
tetryl by co-metabolism with pyruvate as a growth substrate. For every mole of
tetryl metabolized, 1 mole of aniline was produced, and the aniline was further
metabolized. This metabolic conversion of tetryl is likely to be of value in the
anaerobic treatment of tetryl-contaminated soil and ground water, such as found
at many military ammunition sites.
PMID- 10679053
TI - Biodegradability of food-associated extracellular polysaccharides.
AB - Exopolysaccharides (EPSs) produced by lactic acid bacteria, which are common in
fermented foods, are claimed to have various beneficial physiological effects on
humans. Although the biodegradability of EPSs is important in relation to the
bioactive properties, knowledge on this topic is limited. Therefore, the
biodegradability of eight EPSs, six of which were produced by lactic acid
bacteria, was compared with microorganisms from human feces or soil. EPS
degradation was determined from the decrease in polysaccharide-sugar
concentration and by high-performance size exclusion chromatography (HPSEC).
Xanthan, clavan, and the EPSs produced by Streptococcus thermophilus SFi 39 and
SFi 12 were readily degraded, in contrast to the EPSs produced by Lactococcus
lactis ssp. cremoris B40, Lactobacillus sakei 0-1, S. thermophilus SFi20, and
Lactobacillus helveticus Lh59. Clearly, the susceptibility of exopolysaccharides
to biological breakdown can differ greatly, implying that the physiological
effects of these compounds may also vary a lot.
PMID- 10679054
TI - The crystal proteins from Bacillus thuringiensis subsp. thompsoni display a
synergistic activity against the codling moth, Cydia pomonella.
AB - Crystal proteins from Bacillus thuringiensis subsp. thompsoni strain HnC are
active against the codling moth, Cydia pomonella, a major pest of orchards.
Inclusion bodies purified from strain HnC displayed an LC(50) of 3.34 x 10(-3)
microgram/microliter. HnC-purified crystals were tenfold more active than Cry2Aa
and Cry1Aa toxins, and 100-fold more toxic than Cry1Ab. The 34-kDa and 40-kDa
proteins contained in HnC inclusion bodies were shown to act synergistically. The
toxicity of crystal proteins produced by the recombinant B. thuringiensis strain
BT-OP expressing the full-length native operon was about tenfold higher than that
of the 34-kDa protein. When the gene encoding the non-insecticidal 40-kDa
protein, which is not active, was introduced into the recombinant strain
producing only the 34-kDa protein, the toxicity was raised tenfold and was
similar to that of the strain BT-OP.
PMID- 10679055
TI - Occurrence of Bacillus thuringiensis on cured tobacco leaves.
AB - A worldwide survey was conducted to evaluate the frequency and distribution of
Bacillus thuringiensis populations on cured tobacco leaves during post-harvest
storage. In total, 133 tobacco samples of different types and origins were
analyzed. Nine percent of the samples showed the presence of B. thuringiensis,
and 24 B. thuringiensis strains were isolated and characterized. The majority of
the isolates produced bipyramidal crystals, and three fourths of them showed a
second type of crystal protein (cuboidal or heterogeneous crystals). Only three
isolates showed the rhomboidal crystal morphology characteristic of the anti
coleopteran B. thuringiensis subsp. tenebrionis. PCR analysis with primers
specific for cry1 and cry3 genes revealed eight distinct cry gene profiles. The
results of this study indicate that B. thuringiensis is naturally present at low
frequency on the phylloplane of cured tobacco leaves and that its distribution is
worldwide.
PMID- 10679056
TI - Influence of sulfate-reducing bacteria on outdoor hydrogen production by
photosynthetic bacterium with seawater.
AB - The application of seawater for bacterial fermentative production is a cost
effective technology. Hydrogen production by marine photosynthetic bacterium with
seawater failed to continue after more than 10 days, and was accompanied by the
formation of hydrogen sulfide and a change in culture color from red to black.
However, substrate consumption in the blackish culture was comparable to that in
a hydrogen-producing culture. A decrease in hydrogen production occurred upon the
addition of sodium sulfide at concentrations of 1.5 mM or higher. PCR analysis
targeted at the 16S rDNA sequence selective for sulfate-reducing bacteria
revealed the existence of sulfate-reducing bacteria in inoculation cultures of
the phototrophic bacterium and medium for hydrogen production. Hence, the high
sulfate concentration of seawater, the low oxidation-reduction potential under
hydrogen-producing conditions, and the presence of electron donors such as
acetate might promote the metabolic activities of sulfate-reducing bacteria,
resulting in the deterioration of hydrogen production with seawater.
PMID- 10679058
TI - Cutting edge: lipoxin (LX) A4 and aspirin-triggered 15-epi-LXA4 block allergen
induced eosinophil trafficking.
AB - Tissue eosinophilia prevention represents one of the primary targets to new anti
allergic therapies. As lipoxin A4 (LXA4) and aspirin-triggered 15-epi-LXA4 (ATL)
are emerging as endogenous "stop signals" produced in distinct pathologies
including some eosinophil-related pulmonary disorders, we evaluated the impact of
in situ LXA4/ATL metabolically stable analogues on allergen-induced eosinophilic
pleurisy in sensitized rats. LXA4/ATL analogues dramatically blocked allergic
pleural eosinophil influx, while concurrently increasing circulating
eosinophilia, inhibiting the earlier edema and neutrophilia associated with
allergic reaction. The mechanisms underlying this LXA4/ATL-driven allergic
eosinophilia blockade was independent of mast cell degranulation and involved
LXA4/ATL inhibition of both IL-5 and eotaxin generation, as well as platelet
activating factor action. These findings reveal LXA4/ATL as a novel class of
endogenous anti-allergic mediators, capable of preventing local eosinophilia.
PMID- 10679059
TI - Cutting edge: functional role for proline-rich tyrosine kinase 2 in NK cell
mediated natural cytotoxicity.
AB - Protein tyrosine kinase activation is one of the first biochemical events in the
signaling pathway leading to activation of NK cell cytolytic machinery. Here we
investigated whether proline-rich tyrosine kinase 2 (Pyk2), the nonreceptor
protein tyrosine kinase belonging to the focal adhesion kinase family, could play
a role in NK cell-mediated cytotoxicity. Our results demonstrate that binding of
NK cells to sensitive target cells or ligation of beta2 integrins results in a
rapid induction of Pyk2 phosphorylation and activation. By contrast, no
detectable Pyk2 tyrosine phosphorylation is found upon CD16 stimulation mediated
by either mAb or interaction with Ab-coated P815 cells. A functional role for
Pyk2 in natural but not Ab-mediated cytotoxicity was demonstrated by the use of
recombinant vaccinia viruses encoding the kinase dead mutant of Pyk2. Finally, we
provide evidence that Pyk2 is involved in the beta2 integrin-triggered
extracellular signal-regulated kinase activation, supporting the hypothesis that
Pyk2 plays a role in the natural cytotoxicity by controlling extracellular signal
regulated kinase activation.
PMID- 10679060
TI - Cutting edge: differential production of prostaglandin D2 by human helper T cell
subsets.
AB - Several effector molecules, including cytokines, are differentially produced by
Th1 and Th2 cells. We used a gene expression screen method to identify a gene
encoding hematopoietic PG D synthase (hPGDS) which was preferentially expressed
in human Th2 but not Th1 clones. Studies with anti-hPGDS mAbs confirmed the Th2
dominated expression of hPGDS protein. Upon stimulation with anti-CD3 plus anti
CD28 mAbs, coordinated cyclooxygenase-2 expression and PGD2 production were
induced in Th2 lines. hPGDS expression was also observed in a small population
(<1.0%) of peripheral blood CD4+ lymphocytes from healthy adults. Most hPGDS
expressing CD4+ lymphocytes showed a typical Th2-type cytokine pattern. Our
results suggest that, at the sites of Ag presentation, at least part of the Th2
cell population produces PGD2, which may be involved in various aspects of Th2
related immune responses similar to mast cells.
PMID- 10679061
TI - Cutting edge: complement-activating complex of ficolin and mannose-binding lectin
associated serine protease.
AB - Both ficolins and mannose-binding lectin (MBL) are lectins characterized by the
presence of collagen-like and carbohydrate-binding domains in a subunit, although
their carbohydrate-binding moieties are quite different. A fibrinogen-like domain
is in ficolins, and a carbohydrate recognition domain is in MBL. On binding to
pathogens, human MBL activates the complement system via the lectin pathway in
association with two types of MBL-associated serine proteases (MASP), MASP-1 and
MASP-2 and its truncated form, small MBL-associated protein (sMAP, also called
MAp19). We report here that ficolin/P35, a human serum ficolin, was found to
copurify with MASPs and sMAP. MASPs that were complexed with ficolin/P35
exhibited proteolytic activities against complement components C4, C2, and C3.
The ficolin/P35-MASPs-sMAP complex that was bound to Salmonella typhimurium
activated complement. These findings indicate that ficolin/P35 is a second
collagenous lectin capable of activating the lectin pathway and thus plays a role
in innate immunity.
PMID- 10679062
TI - TGF-beta 1 reciprocally controls chemotaxis of human peripheral blood monocyte
derived dendritic cells via chemokine receptors.
AB - We examined the effect of TGF-beta 1 on the chemotactic migratory ability of
human monocyte-derived dendritic cells (DCs). Treatment of immature DCs with TGF
beta 1 resulted in increased expressions of CCR-1, CCR-3, CCR-5, CCR-6, and CXC
chemokine receptor-4 (CXCR-4), which were concomitant with enhanced chemotactic
migratory responses to their ligands, RANTES (for CCR-1, CCR-3, and CCR-5),
macrophage-inflammatory protein-3 alpha (MIP-3 alpha) (for CCR-6), or stromal
cell-derived growth factor-1 alpha (for CXCR-4). Ligation by TNF-alpha resulted
in down-modulation of cell surface expressions of CCR-1, CCR-3, CCR-5, CCR-6, and
CXCR-4, and the chemotaxis for RANTES, MIP-3 alpha, and stromal cell-derived
growth factor-1 alpha, whereas this stimulation up-regulated the expression of
CCR-7 and the chemotactic ability for MIP-3beta. Stimulation of mature DCs with
TGF-beta 1 also enhanced TNF-alpha-induced down-regulation of the expressions of
CCR-1, CCR-3, CCR-5, CCR-6, and CXCR-4, and chemotaxis to their respective
ligands, while this stimulation suppressed TNF-alpha-induced expression of CCR-7
and chemotactic migratory ability to MIP-3 beta. Our findings suggest that TGF
beta 1 reversibly regulates chemotaxis of DCs via regulation of chemokine
receptor expression.
PMID- 10679063
TI - IFN-alpha 2b reduces IL-2 production and IL-2 receptor function in primary CD4+ T
cells.
AB - Initially described as an antiviral cytokine, IFN-alpha has been subsequently
shown to affect several cellular functions, including cellular differentiation
and proliferation. For these reasons, IFN-alpha is currently used in clinical
practice for the treatment of viral infections and malignancies. In this
manuscript, we show two novel mechanisms concomitantly responsible for the
antiproliferative effect of IFN-alpha. First, long-term treatment with IFN-alpha
of primary CD4+ T cells reduced surface expression of CD3 and CD28. These events
resulted in decreased phosphorylation of the mitogen-activated extracellular
signal-regulated activating kinase and its substrate extracellular signal
regulated kinase, leading to diminished production of IL-2. Second, IFN-alpha
treatment of primary CD4+ T cells reduced proliferative response to stimulation
in the presence of exogenous IL-2 by markedly decreasing mRNA synthesis and
surface expression of CD25 (alpha-chain), a critical component of the IL-2R
complex. These results may be relevant for the antitumor effects of IFN-alpha and
may help us to better understand its detrimental role in the inhibition of
proliferation of the bulk of CD4+ T cells (uninfected cells) in HIV-infected
persons, who are known to overproduce IFN-alpha.
PMID- 10679064
TI - Stat6 regulation of in vivo IL-4 responses.
AB - Although in vitro development of a Th2 response from naive CD4+ T cells is Stat6
dependent, mice immunized with a goat Ab to mouse IgD have been reported to
produce a normal primary IL-4 response in Stat6-deficient mice. Experiments have
now been performed with mice immunized with more conventional Ags or inoculated
with nematode parasites to account for this apparent discrepancy. The ability of
an immunogen to induce a primary in vivo IL-4 response in Stat6-deficient mice
was found to vary directly with its ability to induce a strong type 2 cytokine
biased response in normal mice. Even immunogens, however, that induce strong
primary IL-4 responses in Stat6-deficient mice induce poor memory IL-4 responses
in these mice. Consistent with this, Stat6-deficient CD4+ T cells make relatively
normal IL-4 responses when stimulated in vitro for 3 days with anti-CD3 and anti
CD28, but poor IL-4 responses if they are later restimulated with anti-CD3. Thus,
Stat6 signaling enhances primary IL-4 responses that are made as part of a type 0
cytokine response (mixed type 1 and type 2) and is required for normal
development or survival of Th2 memory cells.
PMID- 10679065
TI - Identification of a membrane Ig-induced p38 mitogen-activated protein kinase
module that regulates cAMP response element binding protein phosphorylation and
transcriptional activation in CH31 B cell lymphomas.
AB - The cAMP response element (CRE) binding protein (CREB) is emerging as a key
regulatory factor of gene transcription in B lymphocytes; however, the
postreceptor pathways that regulate CREB activity and CRE-dependent gene
transcription remain largely undefined. We investigated B cell Ag receptor (BCR)
mediated phosphorylation and activation of CREB in the surface IgM+ CH31 B cell
lymphoma, which undergoes Ag-dependent cell death. The activity of p38 mitogen
activated protein kinase (MAPK) was increased in response to BCR ligation.
Phosphorylation of CREB on serine 133, a modification that positively regulates
its trans-activation, was concomitantly increased. Inhibition of p38 MAPK by
pretreating CH31 B cells with the highly specific bicyclic imidazole inhibitor,
SB203580, reduced BCR-induced CREB phosphorylation. BCR cross-linking also led to
increased MAPK-activated protein kinase-2 activity, an enzyme that lies
immediately downstream from p38 MAPK; MAPK-activated protein kinase-2 immune
complexes phosphorylated a peptide substrate containing the CREB serine 133
phosphoacceptor motif. Given the role of CREB in regulating junB gene expression
in mature B lymphocytes, we examined whether p38 MAPK activity was necessary for
CRE-dependent junB transcription in CH31 B cells. BCR ligation led to increased
junB mRNA levels, which were significantly reduced in CH31 B cells pretreated
with SB203580. Activation of a CRE-dependent junB promoter/chloramphenicol
acetyltransferase (CAT) reporter gene by the BCR was also blocked by SB203580.
Similarly, inhibition of p38 MAPK in surface IgM+ WEHI-231 B cell lymphomas
resulted in reduced BCR-induced junB mRNA expression and junB promoter
activation. The results implicate a p38 MAPK pathway in BCR-mediated CREB
phosphorylation and junB transcriptional activation in B cell lymphomas.
PMID- 10679066
TI - 4-1BB costimulation is required for protective anti-viral immunity after peptide
vaccination.
AB - Peptide vaccination induces T cell activation and cytotoxic T cell development.
In an effort to understand what factors can improve immune responses to peptide
vaccination, the role of 4-1BB (CD137) costimulation was examined, since 4-1BB
has been shown to promote T cell responses in other systems. 4-1BBL-deficient (-/
) and wild-type (+/+) mice were immunized with a lipidated lymphocytic
choriomeningitis virus (LCMV) peptide NP396-404. Analysis of peptide-specific
responses early after immunization by CTL assay, intracellular IFN-gamma
staining, and IFN-gamma enzyme-linked immunospot assay (ELISPOT) indicated that
CD8 T cell responses were reduced 3- to 10-fold in the absence of 4-1BB
costimulation. Moreover, when agonistic anti-4-1BB Ab was given, CD8 T cell
responses in 4-1BBL-/- mice were augmented to levels similar to those in 4
1BBL+/+ mice. Two months after immunization, 4-1BBL+/+ mice still had epitope
specific cells and were protected against viral challenge, demonstrating that
peptide vaccination can induce long-term protection. In fact, 70% of CD8 T cells
were specific for the immunizing peptide after viral challenge, demonstrating
that strong, epitope-specific CD8 T cell responses are generated after peptide
vaccination. In contrast, peptide-immunized 4-1BBL-/- mice had fewer epitope
specific cells and were impaired in their ability to resolve the infection. These
results show that immunization with a single LCMV peptide provides long term
protection against LCMV infection and point to costimulatory molecules such as 4
1BB as important components for generating protective immunity after vaccination.
PMID- 10679067
TI - MEK activity regulates negative selection of immature CD4+CD8+ thymocytes.
AB - CD4+CD8+ thymocytes are either positively selected and subsequently mature to CD4
single positive (SP) or CD8 SP T cells, or they die by apoptosis due to neglect
or negative selection. This clonal selection is essential for establishing a
functional self-restricted T cell repertoire. Intracellular signals through the
three known mitogen-activated protein (MAP) kinase pathways have been shown to
selectively guide positive or negative selection. Whereas the c-Jun N-terminal
kinase and p38 MAP kinase regulate negative selection of thymocytes, the
extracellular signal-regulated kinase (ERK) pathway is required for positive
selection and T cell lineage commitment. In this paper, we show that the MAP/ERK
kinase (MEK)-ERK pathway is also involved in negative selection. Thymocytes from
newborn TCR transgenic mice were cultured with TCR/CD3epsilon-specific Abs or TCR
specific agonist peptides to induce negative selection. In the presence of the
MEK-specific pharmacological inhibitors PD98059 or UO126, cell recovery was
enhanced and deletion of DP thymocytes was drastically reduced. Furthermore,
development of CD4 SP T cells was blocked, but differentiation of mature CD8 SP T
cells proceeded in the presence of agonist peptides when MEK activity was
blocked. Thus, our data indicate that the outcome between positively and
negatively selecting signals is critically dependent on MEK activity.
PMID- 10679068
TI - Qualitative changes accompany memory T cell generation: faster, more effective
responses at lower doses of antigen.
AB - The generation of memory T cells is critically important for rapid clearance and
neutralization of pathogens encountered previously by the immune system. We have
studied the kinetics of response and Ag dose requirements for proliferation and
cytokine secretion of CD4+ memory T cells to examine whether there are
qualitative changes which might lead to improved immunity. TCR Tg CD4+ T cells
were primed in vitro and transferred into T cell-deficient hosts. After 6 or more
weeks, the persisting T cells were exclusively small resting cells with a memory
phenotype: CD44high CD62L+/- CD25-. Memory CD4 T cells showed a similar pattern
of response as naive cells to peptide analogues with similar Ag dose requirements
for IL-2 secretion. However, memory cells (derived from both Th2 and Th1
effectors) displayed faster kinetics of cytokine secretion, cell division, and
proliferation, enhanced proliferation in response to low doses of Ag or peptide
analogues, and production of IL-4, IL-5, and IFN-gamma. These results suggest
there is a much more efficient response of CD4 memory T cells to Ag re-exposure
and that the expanded functional capacity of memory cells will promote a rapid
development of effector functions, providing more rapid and effective immunity.
PMID- 10679069
TI - Exclusive Th2 primary effector function in spleens but mixed Th1/Th2 function in
lymph nodes of murine neonates.
AB - Recent studies have shown that neonatal mice are competent to develop mature, Ag
specific Th1 function in situ. However, under many conditions, Th2 responses
dominate in the neonate, while Th1 responses are more prevalent in adults. To
compare further the immune responses of neonates and adults, we used the enzyme
linked immunospot method to measure the frequencies of primary Th1/Th2 effectors
generated in situ in the spleens and lymph nodes. As assessed by the detection of
IFN-gamma- or IL-4-producing cells, adults developed mixed Th1/Th2 responses in
both organs. Neonatal lymph nodes contained mature frequencies of IFN-gamma- and
IL-4-producing cells. In striking contrast, while mature frequencies of Th2 cells
developed in neonatal spleens, virtually no IFN-gamma-secreting cells were
detected. Exclusive Th2 function was observed in both BALB/c and C57BL/6
neonates, strains in which the Th2 and Th1 lineages, respectively, are favored in
adults. Although Th1 effectors were virtually undetectable, the addition of rIL
12 boosted the frequency of IFN-gamma-secreting cells to adult levels. Therefore,
Th1 effectors apparently developed in situ, but Th1 effector function either was
not promoted or was inhibited upon subsequent exposure to the Ag in culture.
Together, these results indicate that the quality of a primary Th response in
neonates is strongly dependent on the site of initial Ag exposure; responses
initiated in the lymph nodes are mixed Th1/Th2, whereas responses occurring in
the spleen are heavily Th2 biased.
PMID- 10679070
TI - The density of peptides displayed by dendritic cells affects immune responses to
human tyrosinase and gp100 in HLA-A2 transgenic mice.
AB - Several HLA-A*0201-restricted peptide epitopes that can be used as targets for
active immunotherapy have been identified within melanocyte differentiation
proteins. However, uncertainty exists as to the most effective way to elicit CD8+
T cells with these epitopes in vivo. We report the use of transgenic mice
expressing a derivative of HLA-A*0201, and dendritic cells, to enhance the
activation of CD8+ T cells that recognize peptide epitopes derived from human
tyrosinase and glycoprotein 100. We find that by altering the cell surface
density of the immunizing peptide on the dendritic cells, either by pulsing with
higher concentrations of peptide, or by changing the MHC-peptide-binding affinity
by generating variants of the parent peptides, the size of the activated CD8+ T
cell populations can be modulated in vivo. Significantly, the density of peptide
that produced the largest response was less than the maximum density achievable
through short-term peptide pulsing. We have also found, however, that while some
variant peptides are effective at eliciting both primary and recall CD8+ T cell
responses that can recognize the parental epitope, other variant epitopes lead to
the outgrowth of CD8+ T cells that only recognize the variant. HLA-A*0201
transgenic mice provide an important model to define which peptide variants are
most likely to stimulate CD8+ T cell populations that recognize the parental,
melanoma-specific peptide.
PMID- 10679071
TI - Heat shock protein 70 is able to prevent heat shock-induced resistance of target
cells to CTL.
AB - Heat shock or transfection with heat shock protein 70 (Hsp70) genes has been
shown to protect tumor cell lines against immune mechanisms of cytotoxicity. We
have reported previously that heat shock confers resistance to CTL in the rat
myeloma cell line Y3 that is Hsp70 defective. Evidence is now presented that
Hsp70 is able to prevent the induction of the resistant phenotype. In Con A
stimulated lymphocytes and in lymphocyte x Y3 somatic cell hybrid clones a
severe, non-Hsp70-inducing heat shock elicits resistance to CTL in contrast to a
heat shock that results in Hsp70 expression. Thus, Hsp70 expression appears to be
negatively associated with the development of resistance. Furthermore, loading of
Y3 cells with recombinant Hsp70 protein before heat shock is able to prevent
resistance. Because apoptosis induced in Y3 cells by heat shock is not affected,
Hsp70 appears to interfere selectively with the CTL-induced lethal pathway that
is found to be calcium but not caspase dependent. It is suggested that after heat
shock Hsp70 enhances the CTL-induced apoptotic pathway by chaperoning certain
proteins in the target cell that are involved in the execution of cell death.
Thus, although shown to confer protection against many cytotoxic mechanisms,
Hsp70 does not appear to be generally cytoprotective. This observation could also
be of relevance when interpreting the effectiveness of tumor immunity.
PMID- 10679072
TI - CpG-DNA activates in vivo T cell epitope presenting dendritic cells to trigger
protective antiviral cytotoxic T cell responses.
AB - MHC class I-restricted T cell epitopes lack immunogenicity unless aided by IFA or
CFA. In an attempt to circumvent the known inflammatory side effects of IFA and
CFA, we analyzed the ability of immunostimulatory CpG-DNA to act as an adjuvant
for MHC class I-restricted peptide epitopes. Using the immunodominant CD8 T cell
epitopes, SIINFEKL from OVA or KAVYNFATM (gp33) from lymphocytic choriomeningitis
virus glycoprotein, we observed that CpG-DNA conveyed immunogenicity to these
epitopes leading to primary induction of peptide-specific CTL. Furthermore,
vaccination with the lymphocytic choriomeningitis virus gp33 peptide triggered
not only CTL but also protective antiviral defense. We also showed that MHC class
I-restricted peptides are constitutively presented by immature dendritic cells
(DC) within the draining lymph nodes but failed to induce CTL responses. The use
of CpG-DNA as an adjuvant, however, initiated peptide presenting immature DC
progression to professional licensed APC. Activated DC induced cytolytic CD8 T
cells in wild-type mice and also mice deficient of Th cells or CD40 ligand. CpG
DNA thus incites CTL responses toward MHC class I-restricted T cell epitopes in a
Th cell-independent manner. Overall, these results provide new insights into CpG
DNA-mediated adjuvanticity and may influence future vaccination strategies for
infectious and perhaps tumor diseases.
PMID- 10679073
TI - HLA-DR-mediated apoptosis susceptibility discriminates differentiation stages of
dendritic/monocytic APC.
AB - Professional APC are characterized by their ability to present peptide via HLA
class II in the presence of costimulatory molecules (CD40, CD80, and CD86). The
efficiency of Ag presentation can be classed as follows: mature dendritic cells
(DC) are most efficient, immature DC and macrophages are intermediate, and
monocytes are considered poor APC. There is a large body of evidence
demonstrating that HLA-DR transmits signals in the APC. In this study, we have
addressed the question of the outcome of HLA-DR signals on APC of the monocyte/DC
lineages throughout their differentiation from immature to mature APC. DC were
generated from both monocytes and CD34+ cells of the same individual, macrophages
were differentiated from monocytes. Immunophenotypical analysis clearly
distinguished these populations. HLA-DR-mediated signals led to marked apoptosis
in mature DC of either CD34 or monocytic origin. Significantly less apoptosis was
observed in immature DC of either origin. Nonetheless, even immature DC were more
susceptible to HLA-DR-mediated apoptosis than macrophages, whereas monocytes were
resistant to HLA-DR-mediated apoptosis. The mechanism of HLA-DR-mediated
apoptosis was independent of caspase activation. Taken together, these data lead
to the notion that signals generated via HLA-DR lead to the demise of mature
professional APC, thereby providing a means of limiting the immune response.
PMID- 10679074
TI - Sensitivity difference to the suppressive effect of prostaglandin E2 among mouse
strains: a possible mechanism to polarize Th2 type response in BALB/c mice.
AB - PGE2 has been shown to play a prominent role in regulating Th1 and Th2 type
responses. We studied the role of PGE2 in IFN-gamma production by Staphylococcus
aureus Cowan I-stimulated spleen cells from several mouse strains such as BALB/c,
C3H/HeN, and C57BL/6. When spleen cells were pretreated with indomethacin
(cyclooxygenase (COX)-1 and COX-2 inhibitor) or NS-398 (COX-2-specific
inhibitor), S. aureus Cowan I -induced IFN-gamma production was increased more
markedly in spleen cells from BALB/c mice than from C3H/HeN and C57BL/6 mouse.
However, PGE2 production was not significantly different among spleen cells from
three mouse strains. When various concentrations of PGE2 were exogeneously added
to spleen cells, PGE2 showed a stronger suppressive effect on IFN-gamma
production in spleen cells from BALB/c mice than from other strains of mice. This
suppressive effect of PGE2 in BALB/c mice mainly depended on IL-12p70 production
by APCs. More PGE2 binding sites were found in BALB/c spleen cells than in
C3H/HeN spleen cells, indicating that the sensitivity difference to the
suppressive effect of PGE2 was due to the difference of the number of PGE2
receptors. The administration of NS-398 into BALB/c mice enhanced Ag-specific IFN
gamma production, but not IL-4 production. This effect is the same as IL-12
administration in vivo. From these results, we propose that the modulation of
PGE2 is important for Th1 activation via IFN-gamma and IL-12p70 production in
vitro and in vivo and that PGE2 is one of the pivotal factors in the Th2-dominant
immune response in BALB/c mice.
PMID- 10679075
TI - RANTES binding and down-regulation by a novel human herpesvirus-6 beta chemokine
receptor.
AB - The human herpesvirus 6 (HHV-6) U51 gene defines a new family of betaherpesvirus
specific genes encoding multiple transmembrane glycoproteins with similarity to G
protein-coupled receptors, in particular, human chemokine receptors. These are
distinct from the HHV-6 U12 and HCMV US28 family. In vitro transcription and
translation as well as transient cellular expression of U51 showed properties of
a multiple transmembrane protein with a 30-kDa monomer as well as high m.w.
aggregates or oligomers. Transient cellularly expressed U51 also appeared to form
dimeric intermediates. Despite having only limited sequence similarity to
chemokine receptors, U51 stably expressed in cell lines showed specific binding
of the CC chemokine RANTES and competitive binding with other beta chemokines,
such as eotaxin; monocyte chemoattractant protein 1, 3, and 4; as well as the HHV
8 chemokine vMIPII. In epithelial cells already secreting RANTES, U51 expression
resulted in specific transcriptional down-regulation. This correlated with
reduced secretion of RANTES protein into the culture supernatants. Regulation of
RANTES levels may alter selective recruitment of circulating inflammatory cells
that the virus can infect and thus could mediate the systemic spread of the virus
from initial sites of infection in epithelia. Alternatively, chemokine regulation
could modulate a protective inflammatory response to aid the spread of virus by
immune evasion. Such mimicry, by viral proteins, of host receptors leading to
down-regulation of chemokine expression is a novel immunomodulatory mechanism.
PMID- 10679076
TI - 1 Alpha,25-dihydroxyvitamin D3 inhibits differentiation, maturation, activation,
and survival of dendritic cells leading to impaired alloreactive T cell
activation.
AB - 1 Alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3), the active form of vitamin D3, is a
potent immunomodulatory agent. Here we show that dendritic cells (DCs) are major
targets of 1,25(OH)2D3-induced immunosuppressive activity. 1,25(OH)2D3 prevents
the differentiation in immature DCs of human monocytes cultured with GM-CSF and
IL-4. Addition of 1,25(OH)2D3 during LPS-induced maturation maintains the
immature DC phenotype characterized by high mannose receptor and low CD83
expression and markedly inhibits up-regulation of the costimulatory molecules
CD40, CD80, and CD86 and of class II MHC molecules. This is associated with a
reduced capacity of DCs to activate alloreactive T cells, as determined by
decreased proliferation and IFN-gamma secretion in mixed leukocyte cultures. 1,
25(OH)2D3 also affects maturing DCs, leading to inhibition of IL-12p75 and
enhanced IL-10 secretion upon activation by CD40 ligation. In addition,
1,25(OH)2D3 promotes the spontaneous apoptosis of mature DCs. The modulation of
phenotype and function of DCs matured in the presence of 1,25(OH)2D3 induces
cocultured alloreactive CD4+ cells to secrete less IFN-gamma upon restimulation,
up-regulate CD152, and down-regulate CD154 molecules. The inhibition of DC
differentiation and maturation as well as modulation of their activation and
survival leading to T cell hyporesponsiveness may explain the immunosuppressive
activity of 1, 25(OH)2D3.
PMID- 10679077
TI - NK1.1+ T cells in the liver arise in the thymus and are selected by interactions
with class I molecules on CD4+CD8+ cells.
AB - NK1.1+ T cells represent a specialized T cell subset specific for CD1d, a
nonclassical MHC class I-restricting element. They are believed to function as
regulatory T cells. NK1.1+ T cell development depends on interactions with CD1d
molecules presented by hematopoietic cells rather than thymic epithelial cells.
NK1.1+ T cells are found in the thymus as well as in peripheral organs such as
the liver, spleen, and bone marrow. The site of development of peripheral NK1.1+
T cells is controversial, as is the nature of the CD1d-expressing cell that
selects them. With the use of nude mice, thymectomized mice reconstituted with
fetal liver cells, and thymus-grafted mice, we provide direct evidence that
NK1.1+ T cells in the liver are thymus dependent and can arise in the thymus from
fetal liver precursor cells. We show that the class I+ (CD1d+) cell type
necessary to select NK1.1+ T cells can originate from TCRalpha-/- precursors but
not from TCRbeta-/- precursors, indicating that the selecting cell is a CD4+CD8+
thymocyte. 5-Bromo-2'-deoxyuridine-labeling experiments suggest that the thymic
NK1.1+ T cell population arises from proliferating precursor cells, but is a
mostly sessile population that turns over very slowly. Since liver NK1.1+ T cells
incorporate 5-bromo-2'-deoxyuridine more rapidly than thymic NK1.1+ T cells, it
appears that liver NK1.1+ T cells either represent a subset of thymic NK1.1+ T
cells or are induced to proliferate after having left the thymus. The results
indicate that NK1.1+ T cells, like conventional T cells, arise in the thymus
where they are selected by interactions with restricting molecules.
PMID- 10679078
TI - Role of IL-6 in directing the initial immune response to schistosome eggs.
AB - The eggs of Schistosoma mansoni are strong inducers of a Th2 response, and
previous work has shown that Ag-specific IL-6 is produced within 24 h after the
injection of eggs into mice. Investigations to determine the role of IL-6 in
orchestrating the early response to schistosome eggs have revealed that IL-12 is
rapidly produced in lymph node cell cultures from egg-injected mice. This "early"
IL-12 primes for the production of IL-6 and IFN-gamma, for in IL-12-/- mice egg
injection fails to stimulate increased production of either of these cytokines.
Furthermore, IL-6 also up-regulates IL-10 production which, together with IL-6,
negatively regulates IL-12 and IFN-gamma production. Finally, IL-10 down
regulates the production of its inducer, IL-6. These data indicate that the anti
inflammatory role of IL-6 may be effected through negative regulation of type 1
(IFN-gamma) and type 1-associated (IL-12) cytokines either directly (by IL-6) or
indirectly (through the induction of IL-10) and suggest that one mechanism by
which eggs may support the development of Th2 responses is through the negative
regulation of the type 1 response.
PMID- 10679079
TI - Specific B cell tolerance is induced by cyclosporin A plus donor-specific blood
transfusion pretreatment: prolonged survival of MHC class I disparate cardiac
allografts.
AB - Donor-specific blood transfusion (DST), designed to prolong allograft survival,
sensitized recipients of the high-responder PVG-RT1u strain, resulting in
accelerated rejection of MHC-class I mismatched (PVG-R8) allografts. Rejection
was found to be mediated by anti-MHC class I (Aa) alloantibody. By pretreating
recipients 4 wk before grafting with cyclosporin A (CsA) daily (x7), combined
with once weekly (x4) DST, rejection was prevented. The investigation explores
the mechanism for this induced unresponsiveness. CD4 T cells purified from the
thoracic duct of CsA/DST-pretreated RT1u rats induced rejection when transferred
to R8 heart-grafted RT1u athymic nude recipients, indicating that CD4 T cells
were not tolerized by the pretreatment. To determine whether B cells were
affected, nude recipients were pretreated, in the absence of T cells, with
CsA/DST (or CsA/third party blood) 4 wk before grafting. The subsequent transfer
of normal CD4 T cells induced acute rejection of R8 cardiac allografts in third
party- but not DST-pretreated recipients; prolonged allograft survival was
reversed by the cotransfer of B cells with the CD4 T cells. Graft survival
correlated with reduced production of anti-MHC class I (Aa) cytotoxic
alloantibody. The results indicated that the combined pretransplant treatment of
CsA and DST induced tolerance in allospecific B cells independently of T cells.
The resulting suppression of allospecific cytotoxic Ab correlated with the
survival of MHC class I mismatched allografts. The induction of B cell tolerance
by CsA has important implications for clinical transplantation.
PMID- 10679080
TI - Engrafting costimulator molecules onto tumor cell surfaces with chelator lipids:
a potentially convenient approach in cancer vaccine development.
AB - The genetic modification of cells to develop cell-based vaccines and to modulate
immune responses in vivo can be risky and inconvenient to perform in clinical
situations. A novel chelator lipid, nitrilotriacetic acid di-tetradecylamine (NTA
DTDA) that, via the NTA group has high affinity for 6His peptide, was used to
directly anchor recombinant forms of T cell costimulatory molecules containing a
C-terminal 6-His sequence onto tumor cell surfaces. Initial experiments using
murine P815 tumor cells established the optimum conditions for incorporating NTA
DTDA onto the membranes of cells. P815 cells with incorporated NTA-DTDAbound
hexahistidine-(6His)-tagged forms of the extracellular domains of murine B7.1 and
CD40 (B7.1-6H and CD40-6H) at very high levels (fluorescence 200-300-fold above
background), and both proteins could be anchored onto the cells simultaneously.
Significant loss of the anchored or "engrafted" protein occurred through membrane
internalization following culture of the cells under physiological conditions,
but P815 cells with engrafted B7.1-6H and/or CD40-6H stimulated the proliferation
of allogenic and syngeneic splenic T cells in vitro, and generated cytotoxic T
cells when used as vaccines in syngeneic animals. Furthermore, the immunization
of syngeneic mice with P815 cells engrafted with B7.1-6H or with B7. 1-6H and
CD40-6H induced protection against challenge with the native P815 tumor. The
results indicate that the use of chelator lipids like NTD-DTDA to engraft
costimulatory and/or other molecules onto cell membranes could provide a
convenient alternative to transfection in the development of cell-based vaccines
and for modulation of immune function.
PMID- 10679081
TI - Low CD86 expression in the nonobese diabetic mouse results in the impairment of
both T cell activation and CTLA-4 up-regulation.
AB - The nonobese diabetic (NOD) mouse spontaneously develops autoimmune insulin
dependent diabetes mellitus and serves as a model for human type I diabetes. NOD
spleen cells proliferate to a lesser extent than those from C57BL/6 and BALB/c
mice in response to anti-CD3. To investigate the cause of this reduced T cell
proliferation, costimulatory molecule expression was investigated. It was found
that NOD macrophages, dendritic cells, and T cells, but not B cells, expressed
lower basal levels of CD86, but not CD80, CD28, or CD40, compared with C57BL/6
and BALB/c. This low CD86 expression was not dependent on the MHC haplotype or on
diabetes development since the NOD-related, diabetes-free mouse strains NON (H
2nb1) and NOR (H-2g7) exhibited similar low levels of CD86 expression and
proliferation. Furthermore, following activation, the relative up-regulation of
CTLA-4, as compared with CD28, was more pronounced on C57BL/6 and BALB/c T cells
as shown by an increased CTLA-4/CD28 ratio. This activation-induced increase in
the CTLA-4/CD28 ratio was markedly reduced on NOD T cells compared with the other
two strains. The low CD86 expression in NOD mice may account for the reduced
increase in both proliferation and the CTLA-4/CD28 ratio, since reducing CD86
expression in C57BL/6 and BALB/c cultures to NOD levels significantly reduces the
proliferation and the CTLA-4/CD28 ratio. Therefore, we propose that a low level
of CD86 expression in the NOD mouse contributes to a defective regulation of
autoreactive T cells by preventing the full activation of T cells and therefore
the up-regulation of CTLA-4.
PMID- 10679082
TI - IL-10 contributes to the inhibition of contact hypersensitivity in mice treated
with photodynamic therapy.
AB - We have explored the effect of photodynamic therapy (PDT) with verteporfin on the
induction and expression of contact hypersensitivity (CHS) to 2,4
dinitrofluorobenzene (DNFB) in normal mice and IL-10-deficient mice. Our results
indicate that DNFB sensitized mice given PDT with verteporfin and whole body red
light irradiation exhibited a significant reduction in CHS compared with control
animals. Administration of rIL-12 reversed the effect(s) of PDT as did treatment
of mice with anti-IL-10-neutralizing Ab. Knockout mice deficient in IL-10 were
found to be resistant to the inhibitory effects of PDT. In vitro proliferative
responses using spleen cells from DNFB-sensitized and PDT-treated mice showed a
significantly lower response to DNBS as compared with cells from DNFB-sensitized
mice or DNFB and PDT-treated IL-10-deficient mice. Finally, naive mice exposed to
PDT exhibited an increase in skin IL-10 levels, which peaked between 72 and 120 h
post-PDT. Together these data support the role of IL-10 as a key modulator in the
inhibition of the CHS response by whole body PDT.
PMID- 10679083
TI - Stage-specific expression of mucosal addressin cell adhesion molecule-1 during
embryogenesis in rats.
AB - Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is essential for lymphocyte
trafficking to gut-associated lymphoid tissues and is implicated in inflammatory
disorders in the gut and pancreatic islets. In this study, we examined the
functional role of MAdCAM-1 during rat ontogeny using newly generated specific
mAb. As previously observed in mice and humans, MAdCAM-1 was preferentially
expressed in high endothelial venules (HEV) in gut-associated lymphoid tissues
and venules of lamina propria in adult rats. Lymphocyte rolling and adhesion on
HEV in Peyer's patches (PP) were completely abrogated with neutralizing anti
MAdCAM-1 mAb, in agreement with the notion that MAdCAM-1 is the principal HEV
ligand for lymphocyte rolling and adhesion in adult PP. In the developing
gastrointestinal tract, MAdCAM-1 was widely expressed in the venules of the
lamina propria of fetal rats. In addition, MAdCAM-1 was also expressed in
follicular dendritic cells in the neonatal PP. Interestingly, MAdCAM-1 expression
was found also in nonmucosal tissues during ontogeny. MAdCAM-1 was transiently
expressed in blood vascular endothelial cells in the fetal skin and neonatal
thymus. Notably, MAdCAM-1-positive blood vessels were localized mainly in the
cortico-medullary junction in the neonatal thymus and about 10-20% of thymocytes,
most of which were either CD4, CD8 double positive or single positive
specifically reacted with soluble MAdCAM-1 via integrin alpha4beta7. After birth,
MAdCAM-1 expression in thymus blood vessels disappeared and concomitantly, the
soluble MAdCAM-1-reactive thymocytes were rapidly down-regulated. Our results
suggest that MAdCAM-1 functions as a vascular addressin in not only mucosal, but
also nonmucosal lymphoid tissues during ontogeny.
PMID- 10679084
TI - The accumulation of dendritic cells in the lung is impaired in CD18-/- but not in
ICAM-1-/- mutant mice.
AB - Bone marrow-derived dendritic cell (DC) precursors migrate via the blood stream
to peripheral tissues to adopt their sentinel function. To identify factors
facilitating their emigration to the lung, mutant mice deficient in E-selectin, P
selectin, E/P-selectin, ICAM-1, or CD18 and their respective controls were
examined. DCs and monocytes/macrophages were immunolabeled with M5/114 and MOMA-2
mAbs, respectively, and quantified morphometrically. Of these genotypes, the
numbers of DC and MOMA-2+ cells were significantly less only in the lungs of CD18
/- mice by 68 and 35% in alveolar walls and by 28 and 26% in venous walls,
respectively. DCs were reduced by 30 and 41% around large and small airways,
respectively, but the number of MOMA-2+ cells in these locations was not
significantly different from controls. Ablation of a single gene may be
associated with augmented expression of other, related gene products. Therefore,
we examined the expression of VCAM-1. Increased numbers of arteries exhibited
continuous luminal VCAM-1 staining in both CD18-/- and ICAM-1-/- mutants. VCAM-1
expression was absent in pulmonary capillaries and unchanged in veins. These data
suggest that under nonperturbing conditions, CD18-mediated adhesion is required
for the full complement of DC precursors to accumulate in the lungs. However, the
defect in CD18-/- mice is partial, suggesting that CD18-independent adhesion
occurs. The alternative pathway may involve VLA-4/VCAM-1 in arteries and venules
but not in capillaries. The smaller defect in ICAM-1-/- mice suggests that the
CD11/CD18 complex recognizes ligands other than ICAM-1 at some sites.
PMID- 10679085
TI - Specific inhibition of glucocorticoid-induced thymocyte apoptosis by substance P.
AB - Glucocorticoids (GC) are strong inducers of thymocyte apoptosis. In the present
study we looked into the possibility that the neuropeptide substance P (SP) might
serve as an antagonist to GC-induced apoptosis. Indeed, SP inhibited
hydrocortisone (HC)-induced apoptosis of CD4+CD8+ thymocytes in mice, both in
vivo and in vitro. It also inhibited HC-induced apoptosis in the T cell hybridoma
line 2B4.11, which is sensitive to GC. The inhibitory effect was complete if SP
was given with HC or within 1 h after it; partial inhibitory effect could be seen
at 2 h and no effect at 3 h. The presence of the SP antagonist nullified SP
effect. The effect was specific to both components of the system (i.e., HC as
apoptosis inducer and SP as its inhibitor), as judged from comparison to three
other apoptosis-inducing means (irradiation, thymic epithelial cells, or retinoic
acid), and to two other neuropeptides (somatostatin and vasoactive intestinal
peptide). SP/HC antagonism was further demonstrated in two relevant molecular
events: 1) HC augmented GC receptor production in our cell system and this was
inhibited by SP; and 2) HC reduced the expression of the transcription factor NF
kappaB, SP increased it and when both were present, SP effect dominated. On the
other hand, the level of IkappaB (NF-kappaB inhibitory molecule) was decreased by
SP, preserved at a relatively high level with HC, and when both SP and HC were
present, SP effect dominated. The intensity of SP effect, both in vivo and in
vitro, its specificity, its inhibition by SP antagonist, as well as the
previously documented presence of SP and its receptor in the thymus suggest that
SP might be a physiological antagonist of the potent thymocyte apoptosis induced
by GC.
PMID- 10679086
TI - Maturation and trafficking of monocyte-derived dendritic cells in monkeys:
implications for dendritic cell-based vaccines.
AB - Human dendritic cells (DC) have polarized responses to chemokines as a function
of maturation state, but the effect of maturation on DC trafficking in vivo is
not known. We have addressed this question in a highly relevant rhesus macaque
model. We demonstrate that immature and CD40 ligand-matured monocyte-derived DC
have characteristic phenotypic and functional differences in vitro. In
particular, immature DC express CC chemokine receptor 5 (CCR5) and migrate in
response to macrophage inflammatory protein-1alpha (MIP-1alpha), whereas mature
DC switch expression to CCR7 and respond exclusively to MIP-3beta and 6Ckine.
Mature DC transduced to express a marker gene localized to lymph nodes after
intradermal injection, constituting 1.5% of lymph node DC. In contrast, cutaneous
DC transfected in situ via gene gun were detected in the draining lymph node at a
20-fold lower frequency. Unexpectedly, the state of maturation at the time of
injection had no influence on the proportion of DC that localized to draining
lymph nodes, as labeled immature and mature DC were detected in equal numbers.
Immature DC that trafficked to lymph nodes underwent a significant up-regulation
of CD86 expression indicative of spontaneous maturation. Moreover, immature DC
exited completely from the dermis within 36 h of injection, whereas mature DC
persisted in large numbers associated with a marked inflammatory infiltrate. We
conclude that in vitro maturation is not a requirement for effective migration of
DC in vivo and suggest that administration of Ag-loaded immature DC that undergo
natural maturation following injection may be preferred for DC-based
immunotherapy.
PMID- 10679088
TI - Lymphotoxin-alpha-dependent spleen microenvironment supports the generation of
memory B cells and is required for their subsequent antigen-induced activation.
AB - Lymphotoxin alpha-deficient (LTalpha-/-) mice show dramatically reduced IgG
responses after either primary or secondary immunizations with sheep red blood
cells (SRBC). When splenocytes from SRBC-primed wild-type donor mice were infused
into irradiated naive wild-type recipient mice, they generated a robust memory
IgG response, but not when infused into LTalpha-/- recipients, indicating that
the microenvironment that develops in LTalpha-/- mice is incompetent to support
the activation of this memory response. When irradiated wild-type mice were
reconstituted with splenocytes from primed LTalpha-/- donors and then challenged
with the same immunizing Ag, no memory response was observed, indicating further
that memory cells could not be generated in the LTalpha-/- environment. To
address which lymphocyte subsets were impaired in the LTalpha-/- mice, we
performed reconstitution experiments using a hapten/carrier system and T cells
and B cells from different primed donors. There was no detectable defect in
either the generation or expression of memory T cells from LTalpha-/- donors. In
contrast, B cells were not primed for memory in the microenvironment of LTalpha-/
mice. Additionally, primed wild-type memory B cells could not express a memory
IgG response in the LTalpha-/- microenvironment. Thus, splenic white pulp
structure, which depends on the expression of LTalpha for its development and
maintenance, is needed to support the generation of memory B cells and to permit
existing memory B cells to express an isotype switched memory Ig response
following antigenic challenge.
PMID- 10679087
TI - NOD/LtSz-Rag1null mice: an immunodeficient and radioresistant model for
engraftment of human hematolymphoid cells, HIV infection, and adoptive transfer
of NOD mouse diabetogenic T cells.
AB - Development of a small animal model for the in vivo study of human immunity and
infectious disease remains an important goal, particularly for investigations of
HIV vaccine development. NOD/Lt mice homozygous for the severe combined
immunodeficiency (Prkdcscid) mutation readily support engraftment with high
levels of human hematolymphoid cells. However, NOD/LtSz-scid mice are highly
radiosensitive, have short life spans, and a small number develop functional
lymphocytes with age. To overcome these limitations, we have backcrossed the null
allele of the recombination-activating gene (Rag1) for 10 generations onto the
NOD/LtSz strain background. Mice deficient in RAG1 activity are unable to
initiate V(D)J recombination in Ig and TCR genes and lack functional T and B
lymphocytes. NOD/LtSz-Rag1null mice have an increased mean life span compared
with NOD/LtSz-scid mice due to a later onset of lymphoma development, are
radioresistant, and lack serum Ig throughout life. NOD/LtSz-Rag1null mice were
devoid of mature T or B cells. Cytotoxic assays demonstrated low NK cell
activity. NOD/LtSz-Rag1null mice supported high levels of engraftment with human
lymphoid cells and human hemopoietic stem cells. The engrafted human T cells were
readily infected with HIV. Finally, NOD/LtSz-Rag1null recipients of adoptively
transferred spleen cells from diabetic NOD/Lt+/+ mice rapidly developed diabetes.
These data demonstrate the advantages of NOD/LtSz-Rag1null mice as a radiation
and lymphoma-resistant model for long-term analyses of engrafted human
hematolymphoid cells or diabetogenic NOD lymphoid cells.
PMID- 10679089
TI - Oral administration of hapten inhibits in vivo induction of specific cytotoxic
CD8+ T cells mediating tissue inflammation: a role for regulatory CD4+ T cells.
AB - We investigated whether oral tolerance could block the development of an
inflammatory response mediated by CD8+ T cells, using a mouse model of oral
tolerance of contact sensitivity (CS) to the hapten 2, 4-dinitrofluorobenzene
(DNFB). In this system, the skin inflammatory response is initiated by hapten
specific class I-restricted cytotoxic CD8+ T (CTL) cells, independently of CD4
help. Oral delivery of DNFB before skin sensitization blocked the CS response by
impairing the development of DNFB-specific CD8+ effector T cells in secondary
lymphoid organs. This was shown by complete inhibition of DNFB-specific CTL and
proliferative responses of CD8+ T cells, lack of specific IFN-gamma-producing
CD8+ T cells, and inability of CD8+ T cells to transfer CS in RAG20/0 mice. RT
PCR and immunohistochemical analysis confirmed that recruitment of CD8+ effectors
of CS in the skin at the site of hapten challenge was impaired in orally
tolerized mice. Sequential anti-CD4 Ab treatment showed that only depletion of
CD4+ T cells during the afferent phase of CS abrogated oral tolerance induction
by restoring high numbers of specific CD8+ effectors in lymphoid organs, whereas
CD4 depletion during the efferent phase of CS did not affect oral tolerance.
These data demonstrate that a single intragastric administration of hapten can
block in vivo induction of DNFB-specific CD8+ CTL responsible for tissue
inflammation and that a subset of regulatory CD4+ T cells mediate oral tolerance
by inhibiting expansion of specific CD8+ effectors in lymph nodes.
PMID- 10679090
TI - Significant role for Fas in the pathogenesis of autoimmune diabetes.
AB - Programmed cell death represents an important pathogenic mechanism in various
autoimmune diseases. Type I diabetes mellitus (IDDM) is a T cell-dependent
autoimmune disease resulting in selective destruction of the beta cells of the
islets of Langerhans. beta cell apoptosis has been associated with IDDM onset in
both animal models and newly diagnosed diabetic patients. Several apoptotic
pathways have been implicated in beta cell destruction, including Fas, perforin,
and TNF-alpha. Evidence for Fas-mediated lysis of beta cells in the pathogenesis
of IDDM in nonobese diabetic (NOD) mice includes: 1) Fas-deficient NOD mice
bearing the lpr mutation (NOD-lpr/lpr) fail to develop IDDM; 2) transgenic
expression of Fas ligand (FasL) on beta cells in NOD mice may result in
accelerated IDDM; and 3) irradiated NOD-lpr/lpr mice are resistant to adoptive
transfer of diabetes by cells from NOD mice. However, the interpretation of these
results is complicated by the abnormal immune phenotype of NOD-lpr/lpr mice. Here
we present novel evidence for the role of Fas/FasL interactions in the
progression of NOD diabetes using two newly derived mouse strains. We show that
NOD mice heterozygous for the FasL mutation gld, which have reduced functional
FasL expression on T cells but no lymphadenopathy, fail to develop IDDM. Further,
we show that NOD-lpr/lpr mice bearing the scid mutation (NOD-lpr/lpr-scid/scid),
which eliminates the enhanced FasL-mediated lytic activity induced by Fas
deficiency, still have delayed onset and reduced incidence of IDDM after adoptive
transfer of diabetogenic NOD spleen cells. These results provide evidence that
Fas/FasL-mediated programmed cell death plays a significant role in the
pathogenesis of autoimmune diabetes.
PMID- 10679091
TI - The IL-2 receptor promotes lymphocyte proliferation and induction of the c-myc,
bcl-2, and bcl-x genes through the trans-activation domain of Stat5.
AB - Studies assessing the role of Stat5 in the IL-2 proliferative signal have
produced contradictory, and thus inconclusive, results. One factor confounding
many of these studies is the ability of IL-2R to deliver redundant mitogenic
signals from different cytoplasmic tyrosines on the IL-2R beta-chain (IL-2Rbeta).
Therefore, to assess the role of Stat5 in mitogenic signaling independent of any
redundant signals, all cytoplasmic tyrosines were deleted from IL-2Rbeta except
for Tyr510, the most potent Stat5-activating site. This deletion mutant retained
the ability to induce Stat5 activation and proliferation in the T cell line CTLL
2 and the pro-B cell line BA/F3. A set of point mutations at or near Tyr510 that
variably compromised Stat5 activation also compromised the proliferative signal
and revealed a quantitative correlation between the magnitude of Stat5 activation
and proliferation. Proliferative signaling by a receptor mutant with a weak Stat5
activating site could be rescued by overexpression of wt Stat5a or b.
Additionally, the ability of this receptor mutant to induce c-myc, bcl-x, and bcl
2 was enhanced by overexpression of wt Stat5. By contrast, overexpression of a
version of Stat5a lacking the C-terminal trans-activation domain inhibited the
induction of these genes and cell proliferation. Thus, Stat5 is a critical
component of the proliferative signal from Tyr510 of the IL-2R and regulates
expression of both mitogenic and survival genes through its trans-activation
domain.
PMID- 10679092
TI - Molecular analysis of the autoantibody response in peptide-induced autoimmunity.
AB - Immunization of nonautoimmune BALB/c mice with multimeric DWEYSVWLSN, a peptide
mimotope of DNA, induces anti-DNA and other lupus-associated Abs. To further
investigate the pathogenesis of the autoantibody response induced by peptide
immunization, we generated hybridomas from peptide-immunized mice that bound
peptide, dsDNA, cardiolipin, Sm/ribonucleoprotein (RNP), or some combination of
these Ags. Analysis of 24 IgM Abs led to the identification of three groups of
Abs: 1) Abs reactive with peptide alone, 2) anti-peptide Abs cross-reactive with
one or more autoantigens, and 3) autoantibodies that do not bind to peptide. The
gene families and particular VH-VL combinations used in those hybridomas binding
DNA were similar to those used in the anti-DNA response in spontaneous murine
lupus. Another similarity to the spontaneous anti-DNA response was the generation
of arginines in the complementarity-determining region-3 of DNA-binding
hybridomas. Interestingly, one Ab had the VH-VL combination present in the
original R4A anti-DNA Ab used to select the DWEYSVWLSN peptide from a phage
display library. Many of the heavy and light chains displayed evidence of somatic
mutation, suggesting that they were made by Ag-activated B cells. Analysis of the
Ab repertoire in peptide-induced autoimmunity may provide insights into the
generation of anti-DNA Abs following exposure to foreign Ag. Furthermore, the
recovery of an Ab with the heavy and light chain combination of the Ab originally
used to isolate the immunizing peptide confirms the utility of phage display
peptide libraries in generating true molecular mimics.
PMID- 10679093
TI - An upstream Oct-1- and Oct-2-binding silencer governs B29 (Ig beta) gene
expression.
AB - The B cell-specific B29 (Igbeta) gene is activated in the earliest B cell
precursors and is expressed throughout B cell development. Tissue-specific
expression of the murine B29 gene is controlled by a B cell-specific promoter
whose activity is governed by a cassette of upstream transcriptional silencers.
This study describes a potent new silencer that is located 5' of the previously
identified B29 silencer elements, FROG and TOAD. Like these known elements, the
new B29 silencer is not restricted to the B29 promoter. Nuclear proteins from all
cell lines tested interacted with this A+T-rich sequence, which closely resembled
a noncanonical octamer binding motif and also conformed to the consensus sequence
for nuclear matrix attachment regions. Interaction of Oct-1 and Oct-2 with the
B29 A+T-rich sequence was confirmed using octamer-specific Abs. Oct-1/Oct-2
binding was required for the inhibitory activity of this sequence because
mutations that blocked Oct-1/Oct-2 binding also eliminated inhibition of the B29
promoter. This B29 A+T-rich sequence specifically interacted with isolated
nuclear matrix proteins in vitro, suggesting that it may also function as a
matrix attachment region element. Maintenance of the level of B29 gene expression
through the interaction of the minimal promoter and the upstream silencer
elements FROG, TOAD, and the A+T-rich Oct-1/Oct-2 binding motif may be essential
for normal B cell development and/or function.
PMID- 10679094
TI - Regulation of the calcium/NF-AT T cell activation pathway by the D2 domain of
CD45.
AB - CD45 contains tandem repeated protein tyrosine phosphatase (PTP) domains and is
essential for the initiation of the earliest activation events resulting from Ag
ligation of the TCR. The second PTP domain (D2) contains four CK2 phosphorylation
sites in a unique 19-aa insert, which are targets of CK2 phosphorylation. This
study was designed to evaluate the roles of these Ser residues in T cell
activation. Transient transfection of the CD45- T cell line, J45.01, with CD45
cDNA incorporating four Ser to Ala (S/A) mutations in the 19-aa insert did not
affect the magnitude of NF-AT activation resulting from TCR ligation. However,
the basal level of NF-AT activity in unstimulated cells expressing the CD45 S/A
mutation was elevated 9- to 10-fold. Increased basal NF-AT was dependent on
extracellular Ca2+ stores as judged by EGTA treatment. In additional experiments,
isolation of stable clones derived from transfection of the CD45 S/A mutant into
CD45- H45.01 cells showed sustained calcium flux after TCR engagement. The
sustained calcium flux returned to baseline levels after addition of EGTA,
suggesting that the expression of the CD45 S/A mutant may have prevented
deactivation of plasma membrane calcium channels. Consideration of both transient
and stable transfection systems suggests that in addition to being essential for
initial events in T cell triggering, the intact CD45 D2, 19-aa insert is
necessary for regulation of TCR-mediated calcium signaling pathways.
PMID- 10679095
TI - Identification of a gene coding for a new squamous cell carcinoma antigen
recognized by the CTL.
AB - Peptide-based specific immunotherapy has resulted in tumor regression in some
melanoma patients. However, tumor Ags and peptides for specific immunotherapy,
except for treatment of melanomas, have not yet been well identified. In this
study, we report a gene encoding a new squamous cell carcinoma (SCC) Ag
recognized by cells of the HLA-A24-restricted and tumor-specific CTL line. This
gene with 3958-bp length was transcribed from the chromosome 6q22 with six exons,
and its mRNA was ubiquitously expressed in both SCCs and normal tissues, and
partly expressed in adenocarcinomas. The deduced 958-aa sequence encoded by this
gene showed no similarity to any known amino acid sequences. This gene product
had a characteristic of an endoplasmic reticulum-resident protein. A 100-kDa
protein was detected in the vast majority of SCCs from various tissues, in
majority of renal cell carcinomas and brain tumors, and in about one-third of
melanomas and adenocarcinomas from various organs other than the breast. In
contrast, it was not expressed at all in any of the normal cells or tissues
tested, including the testis and fetal liver. Three different peptides at
positions 93-101, 161-169, and 899-907 of this Ag were recognized by this CTL
line, and all of them induced HLA-A24-restricted and tumor-specific CTLs from
PBMCs of SCC patients. Therefore, these peptides may be useful for peptide-based
specific immunotherapy of HLA-A24+ patients with SCC in various organs, as well
as for treatment of other cancer.
PMID- 10679096
TI - IL-12-independent Th1-type immune responses to respiratory viral infection:
requirement of IL-18 for IFN-gamma release in the lung but not for the
differentiation of viral-reactive Th1-type lymphocytes.
AB - We demonstrated that IL-12 was induced during primary or secondary pulmonary
adenoviral infection in wild-type (wt) mice. However, cellular responses were not
compromised in the lungs of IL-12-/- mice. The level of IFN-gamma in the lung was
similar in wt and IL-12-/- mice during pulmonary viral infection. Upon Ag
stimulation in vitro, lymphocytes from draining lymph nodes or spleen of infected
IL-12-/- mice released large amounts of IFN-gamma, but not IL-4, which were
comparable to those released by wt lymphocytes. Furthermore, a predominantly
IgG2a response to adenoviral infection was unimpaired in IL-12-/- mice. These
significant anti-adenoviral Th1-type responses in IL-12-/- mice led to an
efficient clearance of virus-infected cells in the lung. Whether IL-18 was
involved in IL-12-independent anti-adenoviral immune responses was investigated.
Abrogation of endogenous IL-18 by an Ab resulted in diminished IFN-gamma release
and lymphocytic infiltrate in the lung during adenoviral infection. Nevertheless,
the development of lymphocytes of the Th1 phenotype was unimpaired in the absence
of both IL-12 and IL-18. In contrast to their intact ability to mount Th1-type
responses to viral infection, IL-12-/- mice suffered impaired Th1-type immune
responses to pulmonary mycobacterial infection. Our findings suggest that IL-12,
although induced, is not required for Th1-type responses to respiratory viral
infection, in contrast to mycobacterial infection. IL-18 is required for the
optimal release of IFN-gamma in the lung during viral infection, but is not
required for the generation of virus-reactive Th1-type lymphocytes. Th1
differentiation during respiratory adenoviral infection may involve molecules
different from IL-12 or IL-18.
PMID- 10679097
TI - Schistosome infection of transgenic mice defines distinct and contrasting
pathogenic roles for IL-4 and IL-13: IL-13 is a profibrotic agent.
AB - Experimental Schistosoma mansoni infections of mice lead to a dynamic type 2
cytokine-mediated pathological process. We have used IL-4-deficient, IL-13
deficient, and IL-4/13-deficient mice to dissect the role of these cytokines in
the development of immune response and pathology following S. mansoni infection.
We demonstrate that while both of these cytokines are necessary to develop a
robust Th2 cell-driven, eosinophil-rich granuloma response, they also perform
disparate functions that identify novel sites for therapeutic intervention. IL-13
deficient mice demonstrated significantly enhanced survival following infection,
which correlated with reduced hepatic fibrosis. In contrast, increased mortality
was manifest in IL-4-deficient and IL-4/13-deficient mice, and this correlated
with hepatocyte damage and intestinal pathology. Therefore, we demonstrate that
during a dynamic type 2 cytokine disease process IL-13 is detrimental to survival
following infection, whereas IL-4 is beneficial.
PMID- 10679098
TI - Lipopolysaccharide inhibits HIV-1 infection of monocyte- derived macrophages
through direct and sustained down-regulation of CC chemokine receptor 5.
AB - It is now well established that HIV-1 requires interactions with both CD4 and a
chemokine receptor on the host cell surface for efficient infection. The
expression of the CCR5 chemokine receptor in human macrophages facilitates HIV-1
entry into these cells, which are considered important in HIV pathogenesis not
only as viral reservoirs but also as modulators of altered inflammatory function
in HIV disease and AIDS. LPS, a principal constituent of Gram-negative bacterial
cell walls, is a potent stimulator of macrophages and has been shown to inhibit
HIV infection in this population. We now present evidence that one mechanism by
which LPS mediates its inhibitory effect on HIV-1 infection is through a direct
and unusually sustained down-regulation of cell-surface CCR5 expression. This LPS
mediated down-regulation of CCR5 expression was independent of de novo protein
synthesis and differed from the rapid turnover of these chemokine receptors
observed in response to two natural ligands, macrophage-inflammatory protein
1alpha and -1beta. LPS did not act by down-regulating CCR5 mRNA (mRNA levels
actually increased slightly after LPS treatment) or by enhancing the degradation
of internalized receptor. Rather, the observed failure of LPS-treated macrophages
to rapidly restore CCR5 expression at the cell-surface appeared to result from
altered recycling of chemokine receptors. Taken together, our results suggest a
novel pathway of CCR5 recycling in LPS-stimulated human macrophages that might be
targeted to control HIV-1 infection.
PMID- 10679099
TI - Granulocyte-macrophage colony-stimulating factor in the innate immune response to
Pneumocystis carinii pneumonia in mice.
AB - Innate immunity plays an important role in pulmonary host defense against
Pneumocystis carinii, an important pathogen in individuals with impaired cell
mediated immunity. We investigated the role of GM-CSF in host defense in a model
of P. carinii pneumonia induced by intratracheal inoculation of CD4-depleted
mice. Lung GM-CSF levels increased progressively during the infection and were
significantly greater than those in uninfected controls 3, 4, and 5 wk after
inoculation. When GM-CSF gene-targeted mice (GM-/-) depleted of CD4+ cells were
inoculated with P. carinii, the intensities of infection and inflammation were
increased significantly compared with those in CD4-depleted wild-type mice. In
contrast, transgenic expression of GM-CSF directed solely in the lungs of GM-/-
mice (using the surfactant protein C promoter) dramatically decreased the
intensity of infection and inflammation 4 wk after inoculation. The
concentrations of surfactant proteins A and D were greater in both uninfected and
infected GM-/- mice compared with those in wild-type controls, suggesting that
this component of the innate response was preserved in the GM-/- mice. However,
alveolar macrophages (AM) from GM-/- mice demonstrated impaired phagocytosis of
purified murine P. carinii organisms in vitro compared with AM from wild-type
mice. Similarly, AM production of TNF-alpha in response to P. carinii in vitro
was totally absent in AM from GM-/- mice, while GM-CSF-replete mice produced
abundant TNF in this setting. Thus, GM-CSF plays a critical role in the
inflammatory response to P. carinii in the setting of impaired cell-mediated
immunity through effects on AM activation.
PMID- 10679100
TI - Purification and characterization of two mannan-binding lectins from mouse serum.
AB - Mannan-binding lectin (MBL) is a serum protein that activates the complement
system after binding to glycoconjugates found on the surface of microorganisms.
By molecular cloning two forms of MBL have been identified in the mouse (mMBL-A
and mMBL-C), but only mMBL-A has been purified and characterized at the protein
level. MBL-C has been termed the liver form of MBL. The present report describes
the purification and characterization of mMBL-A and mMBL-C from serum. The two
forms of mMBL could be separated both by ion-exchange and carbohydrate-affinity
chromatography. The initial identification by immunochemical technique was
confirmed by N-terminal amino-acid sequencing. Both proteins give bands
corresponding to polypeptide chains of 28 kDa on SDS-PAGE in the reduced state,
but mMBL-A migrated more rapidly than mMBL-C in acid/urea-PAGE, in accordance
with the calculated pIs. Both forms mediated activation of complement component
C4 in mannan-coated microtiter wells. MBL-A showed a higher affinity for d
glucose and alpha-methyl-d -glucose then did MBL-C. Serum concentrations of mMBL
A in laboratory strains and wild mice were found to vary from 5 to 80 microg/ml,
with wild mice tending to show higher levels than laboratory strains.
PMID- 10679101
TI - Mice bearing late-stage tumors have normal functional systemic T cell responses
in vitro and in vivo.
AB - Immune suppression in tumor-bearing hosts is considered to be one factor causally
associated with the growth of antigenic tumors. Support for this hypothesis has
come from reports that spleen T cells in tumor-bearing mice are deficient in
either priming or effector phase functions. We have reexamined this hypothesis in
detail using multiple murine tumor models, including transplantable
adenocarcinoma, melanoma, sarcoma, and thymoma, and also a transgenic model of
spontaneous breast carcinoma. In both in vitro and in vivo assays of T cell
function (proliferation, cytokine production, induction of CD8+ alloreactive CTL,
and development of anti-keyhole limpet hemocyanin CD4+ T cells, rejection of
allogeneic or syngeneic regressor tumors, respectively) we show that mice bearing
sizable tumor burdens are not systemically suppressed and do not have diminished
T cell functions. Therefore, if immune suppression is a causal function in the
growth of antigenic tumor, the basis for escape from immune destruction is likely
to be dependent upon tumor-induced T cell dysfunction at the site of tumor
growth.
PMID- 10679102
TI - Decreased resistance of B cell-deficient mice to infection with Toxoplasma gondii
despite unimpaired expression of IFN-gamma, TNF-alpha, and inducible nitric oxide
synthase.
AB - The role of B cells in resistance against Toxoplasma gondii was studied using B
cell-deficient (muMT) mice. Following peroral infection with 10 cysts of the ME49
strain, all muMT mice survived the acute stage of the infection but died between
3 and 4 wk after infection. In contrast, all control mice were alive at 8 wk
after infection. At the stage during which muMT animals succumbed to the
infection, parasite replication and pathology were most evident in their brains;
small numbers of tachyzoites were also detectable in their lungs. Significantly
greater numbers of T. gondii cysts and areas of inflammation associated with
tachyzoites were observed in brains of muMT than in control mice. Large areas of
necrosis associated with numerous tachyzoites were observed only in brains of
muMT mice. Anti-T. gondii IgG Abs were detected only in sera of control mice,
whereas similar levels of IFN-gamma were detected in sera of both strains of
mice. Amounts of mRNA for IFN-gamma, IL-10, and inducible NO synthase in the
brain did not differ between infected muMT and control mice. Expression of mRNA
for TNF-alpha was increased in brains of muMT mice. Administration of polyclonal
rabbit anti-T. gondii IgG Ab prevented early mortality and pathology associated
with tachyzoites in the brain in the infected muMT mice. These results indicate
that B cells play an important role, most likely through their production of
specific Abs, in resistance to persistent active (tachyzoite) infection with T.
gondii in mice, especially in the brain and lung.
PMID- 10679103
TI - Th cell-deficient mice control influenza virus infection more effectively than Th
and B cell-deficient mice: evidence for a Th-independent contribution by B cells
to virus clearance.
AB - The notion that MHC class I- restricted CD8+ T (Tc) cells are capable of
resolving autonomously infections with influenza virus is based largely on
studies testing virus strains of low pathogenicity in CD4+ T (Th) cell
deficient/depleted mice. To test whether this holds also for pathogenic strains
and to exclude possible contributions by B cells, we analyzed PR8 infection in Th
cell-depleted B cell-deficient (muMT) mice. These mice, termed muMT (-CD4),
showed 80% mortality after infection with a small dose of PR8, which resulted in
insignificant mortality in intact or Th cell-depleted BALB/c mice. Infection of
muMT(-CD4) mice with a virus of low pathogenicity was resolved without mortality,
but, compared with intact BALB/c mice, with delay of approximately 5 and
approximately 20 days from lung and nose, respectively. The low mortality of Th
cell-depleted BALB/c mice suggested that B cells contributed to recovery in a Th
independent manner. This was verified by showing that transfer of 8-10 million T
cell-depleted naive spleen cells into muMT(-CD4) mice 1 day before infection
reduced mortality to 0%. The mechanism by which B cells improved recovery was
investigated. We found no evidence that they operated by improving the lung
associated Tc response. Treatment of infected muMT(-CD4) mice with normal mouse
serum spiked with hemagglutinin-specific IgM did not reduce mortality. Taken
together, the data show that 1) the Tc response is capable of resolving
autonomously (in conjunction with innate defenses) influenza virus infections,
although with substantial delay compared with intact mice, and 2) B cells can
contribute to recovery by a Th-independent mechanism.
PMID- 10679104
TI - Neutralization of IL-18 reduces neutrophil tissue accumulation and protects mice
against lethal Escherichia coli and Salmonella typhimurium endotoxemia.
AB - In addition to stimulating IFN-gamma synthesis, IL-18 also possesses inflammatory
effects by inducing synthesis of the proinflammatory cytokines TNF and IL-1beta
and the chemokines IL-8 and macrophage inflammatory protein-1alpha. We
hypothesized that neutralization of IL-18 would have a beneficial effect in
lethal endotoxemia in mice. IL-1beta converting enzyme (ICE)-deficient mice,
lacking the ability to process mature IL-18 and IL-1beta, were completely
resistant to lethal endotoxemia induced by LPS derived from either Escherichia
coli or Salmonella typhimurium. In contrast, both wild-type and IL-1beta-/- mice
were equally susceptible to the lethal effects of LPS, implicating that absence
of mature IL-18 or IFN-gamma but not IL-1beta in ICE-/- mice is responsible for
this resistance. However, IFN-gamma-deficient mice were not resistant to S.
typhimurium LPS, suggesting an IFN-gamma-independent role for IL-18. Anti-IL-18
Abs protected mice against a lethal injection of either LPS. Anti-IL-18 treatment
also reduced neutrophil accumulation in liver and lungs. The increased survival
was accompanied by decreased levels of IFN-gamma and macrophage inflammatory
protein-2 in anti-IL-18-treated animals challenged with E. coli LPS, whereas IFN
gamma and TNF concentrations were decreased in treated mice challenged with S.
typhimurium. In conclusion, neutralization of IL-18 during lethal endotoxemia
protects mice against lethal effects of LPS. This protection is partly mediated
through inhibition of IFN-gamma production, but mechanisms involving decreased
neutrophil-mediated tissue damage due to the reduction of either chemokines (E.
coli LPS) or TNF (S. typhimurium LPS) synthesis by anti-IL-18 treatment may also
be involved.
PMID- 10679105
TI - Role of CC chemokines (macrophage inflammatory protein-1 beta, monocyte
chemoattractant protein-1, RANTES) in acute lung injury in rats.
AB - The role of the CC chemokines, macrophage inflammatory protein-1 beta (MIP-1
beta), monocyte chemotactic peptide-1 (MCP-1), and RANTES, in acute lung
inflammatory injury induced by intrapulmonary deposition of IgG immune complexes
injury in rats was determined. Rat MIP-1 beta, MCP-1, and RANTES were cloned, the
proteins were expressed, and neutralizing Abs were developed. mRNA and protein
expression for MIP-1 beta and MCP-1 were up-regulated during the inflammatory
response, while mRNA and protein expression for RANTES were constitutive and
unchanged during the inflammatory response. Treatment of rats with anti-MIP-1
beta Ab significantly decreased vascular permeability by 37% (p = 0.012), reduced
neutrophil recruitment into lung by 65% (p = 0.047), and suppressed levels of TNF
alpha in bronchoalveolar lavage fluids by 61% (p = 0.008). Treatment of rats with
anti-rat MCP-1 or anti-rat RANTES had no effect on the development of lung
injury. In animals pretreated intratracheally with blocking Abs to MCP-1, RANTES,
or MIP-1 beta, significant reductions in the bronchoalveolar lavage content of
these chemokines occurred, suggesting that these Abs had reached their targets.
Conversely, exogenously MIP-1 beta, but not RANTES or MCP-1, caused enhancement
of the lung vascular leak. These data indicate that MIP-1 beta, but not MCP-1 or
RANTES, plays an important role in intrapulmonary recruitment of neutrophils and
development of lung injury in the model employed. The findings suggest that in
chemokine-dependent inflammatory responses in lung CC chemokines do not
necessarily demonstrate redundant function.
PMID- 10679106
TI - Lipoxin A4 inhibits IL-1 beta-induced IL-6, IL-8, and matrix metalloproteinase-3
production in human synovial fibroblasts and enhances synthesis of tissue
inhibitors of metalloproteinases.
AB - Lipoxins are a novel class of endogenous eicosanoid mediators that potently
inhibit inflammatory events by signaling via specific receptors expressed on
phagocytic cells. Animal models have shown that lipoxin A4 (LXA4) down-regulates
inflammation in vivo. Here we demonstrate, for the first time, the expression of
LXA4 receptors, and their up-regulation by IL-1 beta, in normal human synovial
fibroblasts (SF). We examined whether exogenous LXA4 abrogated IL-1 beta
stimulation of SF in vitro. IL-1 beta induced the synthesis of IL-6, IL-8, and
matrix metalloproteinases (MMP)-1 and -3. At nanomolar concentrations, LXA4
inhibited these IL-1 beta responses with reduction of IL-6 and IL-8 synthesis, by
45 +/- 7% and 75 +/- 11%, respectively, and prevented IL-1 beta-induced MMP-3
synthesis without significantly affecting MMP-1 levels. Furthermore, LXA4 induced
a 2-fold increase of tissue inhibitor of metalloproteinase (TIMP)-1 and a
approximately 3-fold increase of TIMP-2 protein levels. LXA4 inhibitory responses
were dose dependent and were abrogated by pretreatment with LXA4 receptor
antiserum. LXA4-induced changes of IL-6 and TIMP were accompanied by parallel
changes in mRNA levels. These results indicate that LXA4 in activated SF inhibits
the synthesis of inflammatory cytokines and MMP and stimulates TIMP production in
vitro. These findings suggest that LXA4 may be involved in a negative feedback
loop opposing inflammatory cytokine-induced activation of SF.
PMID- 10679107
TI - Role for IgE in airway secretions: IgE immune complexes are more potent inducers
than antigen alone of airway inflammation in a murine model.
AB - IgE is present in airway secretions from human patients with allergic rhinitis
and bronchial asthma. However, the contribution of IgE present locally to the
overall airway inflammation is not well understood. We hypothesize that Ag
specific IgE can capture airborne Ags and form immune complexes. These immune
complexes may function as potent inducers of immune responses in the lung,
contributing to the perpetuation of airway inflammation. BALB/c mice were first
sensitized with OVA in alum systemically and then challenged with nebulized OVA.
Bronchoalveolar lavage (BAL) fluid from these mice contained significant amounts
of IgE, of which >50% was Ag specific. The IgE levels in airway secretions
remained elevated for more than 15 days after the termination of Ag exposure.
Significant amounts of IgE-OVA immune complexes were detected in BAL fluid from
the OVA-challenged mice. For comparison of IgE immune complexes vs Ag alone, we
treated OVA-immunized mice with intranasal administration of trinitrophenyl-OVA
or trinitrophenyl-OVA-anti-DNP IgE. Those treated with the immune complexes
showed significantly higher levels of IL-4 and more pronounced eosinophilia in
BAL fluid than did those receiving the Ag alone. The IgE immune complexes did not
augment the inflammatory response in high affinity IgE receptor (FcepsilonRI)
deficient mice. We conclude that IgE present in the airways can capture the Ag
and that the immune complexes thus formed may augment allergic airway response in
an FcepsilonRI-dependent manner. Thus, IgE present in airway secretions may
facilitate Ag-mediated allergic airway inflammation.
PMID- 10679108
TI - Neutrophil activation by bacterial lipoprotein versus lipopolysaccharide:
differential requirements for serum and CD14.
AB - Neutrophil activation plays an important role in the inflammatory response to
Gram-negative bacterial infections. LPS has been shown to be a major mediator of
neutrophil activation which is accompanied by an early down-regulation of L
selectin and up-regulation of CD1lb/CD18. In this study, we investigated whether
lipoprotein (LP), the most abundant protein in the outer membrane of bacteria
from the family Enterobacteriaceae, can activate neutrophils and whether this
activation is mediated by mechanisms that differ from those used by LPS or
Escherichia coli diphosphoryl lipid A (EcDPLA). Neutrophil activation was
assessed by measuring down-regulation of L-selectin and up-regulation of
CD11b/CD18. When comparing molar concentrations of LP vs EcDPLA, LP was more
potent (four times) at activating neutrophils. In contrast to LPS/EcDPLA, LP
activation of neutrophils was serum independent. However, LP activation of
neutrophils was enhanced by the addition of soluble CD14 and/or LPS-binding
protein. In the presence of serum, LP activation of neutrophils was inhibited by
different mAbs to CD14. This inhibition was significantly reduced or absent when
performed in the absence of serum. Diphosphoryl lipid A from Rhodobacter
spheroides (RaDPLA) completely inhibited LPS/EcDPLA activation of neutrophils but
only slightly inhibited LP activation of neutrophils. These results suggest that
LP activation of human neutrophils can be mediated by a mechanism that is
different from LPS activation and that LP is a potentially important component in
the development of diseases caused by Gram-negative bacteria of the family
Enterobacteriaceae.
PMID- 10679109
TI - Functional genomic analysis in arthritis-affected cartilage: yin-yang regulation
of inflammatory mediators by alpha 5 beta 1 and alpha V beta 3 integrins.
AB - Osteoarthritis-affected cartilage exhibits enhanced expression of fibronectin
(FN) and osteopontin (OPN) mRNA in differential display and bioinformatics
screen. Functional genomic analysis shows that the engagement of the integrin
receptors alpha 5 beta 1 and alpha v beta 3 of FN and OPN, respectively, have
profound effects on chondrocyte functions. Ligation of alpha 5 beta 1 using
activating mAb JBS5 (which acts as agonist similar to FN N-terminal fragment) up
regulates the inflammatory mediators such as NO and PGE2 as well as the
cytokines, IL-6 and IL-8. Furthermore, up-regulation of these proinflammatory
mediators by alpha 5 beta1 integrin ligation is mediated via induction and
autocrine production of IL-1 beta, because type II soluble IL-1 decoy receptor
inhibits their production. In contrast, alpha v beta 3 complex-specific function
blocking mAb (LM609), which acts as an agonist similar to OPN, attenuates the
production of IL-1 beta, NO, and PGE2 (triggered by alpha 5 beta 1, IL-1 beta, IL
18, or IL-1 beta, TNF-alpha, plus LPS) in a dominant negative fashion by
osteoarthritis-affected cartilage and activated bovine chondrocytes. These data
demonstrate a cross-talk in signaling mechanisms among integrins and show that
integrin-mediated "outside in" and "inside out" signaling very likely influences
cartilage homeostasis, and its deregulation may play a role in the pathogenesis
of osteoarthritis.
PMID- 10679110
TI - Lipopolysaccharide induces scavenger receptor A expression in mouse macrophages:
a divergent response relative to human THP-1 monocyte/macrophages.
AB - Gene deletion studies indicate that the macrophage scavenger receptor A (SR-A)
protects mice from LPS-induced endotoxemia. Paradoxically, cultured human
monocyte-derived macrophages down-regulate SR-A expression when exposed to LPS.
We found that human THP-1 monocyte/macrophages decrease SR-A expression in
response to LPS independent of their differentiation status. In contrast, primary
and elicited mouse peritoneal macrophages as well as the J774A.1 and RAW264.7
mouse macrophage lines increase SR-A expression in response to LPS. Exposure to
LPS caused J774A.1 and RAW264.7 cells to increase SR-A transcripts by 3- and 5
fold, respectively. LPS caused a concomitant 3-fold increase in SR-A protein
levels and increased cell membrane expression of the receptor. RAW264.7 cells
increased SR-A transcript levels in response to LPS at concentrations as low as 1
ng/ml, and the response was saturated at 10 ng/ml. The LPS induction of SR-A
transcripts required continual protein synthesis and began at 8 h, peaked by 16
h, and persisted for at least 48 h. LPS induction did not increase SR-A gene
transcription or affect alternative transcript splicing, but mildly increased
mature transcript stability and proceeded in the presence of actinomycin D.
Finally, treatment of RAW264.7 cells with TNF-alpha did not induce SR-A
transcript levels, indicating that a TNF-alpha autocrine/paracrine signaling
mechanism alone is not sufficient to recapitulate the LPS induction of SR-A
transcripts. The induction of SR-A expression by LPS-stimulated mouse macrophages
is the opposite of the down-regulation of SR-A reported in human monocyte-derived
macrophages and may have implications for the observed resistance mice show
toward endotoxemia.
PMID- 10679111
TI - IFN-gamma-inducing factor (IL-18) increases allergic sensitization, serum IgE,
Th2 cytokines, and airway eosinophilia in a mouse model of allergic asthma.
AB - We investigated the effects of IFN-gamma-inducing factor (IL-18) in a ragweed
(RW) mouse model of allergic asthma. Administration of IL-18 in conjunction with
allergic sensitization and challenge in wild-type, but not IFN-gamma -/- mice,
inhibited the bronchoalveolar lavage (BAL) eosinophilia induced by RW challenge,
and increased serum levels of RW-specific IgG2a and production of IFN-gamma from
splenocytes cultured with RW, indicating a critical role for IFN-gamma in
mediating these effects. Paradoxically, the same treatment schedule in WT mice
increased serum levels of RW-specific IgE and IgG1, and production of IL-4 and IL
5 from splenocytes cultured with RW. When the effects of the same IL-18 treatment
schedule were allowed to mature for 3 wk, the inhibition of lung eosinophil
recruitment was replaced by augmentation of lung eosinophil recruitment. In
another experiment, IL-18 administered only with allergic sensitization increased
BAL eosinophilia and lung expression of IL-5 and IFN-gamma, while IL-18
administered only with RW challenge decreased BAL eosinophilia and increased lung
IFN-gamma expression, while lung expression of IL-5 remained unchanged. IL-18
administered without RW or adjuvant to naive mice increased total serum IgE
levels. Finally, intrapulmonary administrations of IL-18 plus RW in naive mice
dramatically increased Th2 cytokine production, IgE levels, eosinophil
recruitment, and airway mucus, demonstrating induction of allergic sensitization.
This is the first report demonstrating that IL-18 promotes a Th2 phenotype in
vivo, and potently induces allergic sensitization. These results suggest that IL
18 may contribute to the pathogenesis of allergic asthma.
PMID- 10679112
TI - A conserved mycobacterial heat shock protein (hsp) 70 sequence prevents adjuvant
arthritis upon nasal administration and induces IL-10-producing T cells that
cross-react with the mammalian self-hsp70 homologue.
AB - Immunization with Mycobacterium tuberculosis heat shock protein (hsp) 60 has been
shown to protect rats from experimental arthritis. Previously, the protection
inducing capacity was shown to reside in the evolutionary conserved parts of the
molecule. Now we have studied the nature of the arthritis suppressive capacity of
a distinct, antigenically unrelated protein, M. tuberculosis hsp70. Again, a
conserved mycobacterial hsp70 sequence was found to be immunogenic and to induce
T cells that cross-reacted with the rat homologue sequence. However, in this case
parenteral immunization with the peptide containing the critical cross-reactive T
cell epitope did not suppress disease. Upon analysis of cytokines produced by
these peptide-specific T cells, high IL-10 production was found, as was the case
with T cells responsive to whole hsp70 protein. Nasal administration of this
peptide was found to lead to inhibition of subsequent adjuvant arthritis
induction. The data presented here shows the intrinsic capacity of conserved
bacterial hsp to trigger self-hsp cross-reactive T cells with the potential to
down-regulate arthritis via IL-10.
PMID- 10679113
TI - T lymphocytes activated by persistent viral infection differentially modify the
expression of metalloproteinases and their endogenous inhibitors, TIMPs, in human
astrocytes: relevance to HTLV-I-induced neurological disease.
AB - Activation of T lymphocytes by human pathogens is a key step in the development
of immune-mediated neurologic diseases. Because of their ability to invade the
CNS and their increased secretion of proinflammatory cytokines, activated CD4+ T
cells are thought to play a crucial role in pathogenesis. In the present study,
we examined the expression of inflammatory mediators the cytokine-induced
metalloproteinases (MMP-2, -3, and -9) and their endogenous inhibitors, tissue
inhibitors of metalloproteinases (TIMP-1, -2, and -3), in human astrocytes in
response to activated T cells. We used a model system of CD4+ T lymphocytes
activated by persistent viral infection (human T lymphotropic virus, HTLV-I) in
transient contact with human astrocytes. Interaction with T cells resulted in
increased production of MMP-3 and active MMP-9 in astrocytes despite increased
expression of endogenous inhibitors, TIMP-1 and TIMP-3. These data suggest
perturbation of the MMP/TIMP balance. These changes in MMP and TIMP expression
were mediated, in part, by soluble factors (presumably cytokines) secreted by
activated T cells. Integrin-mediated cell adhesion is also involved in the change
in MMP level, since blockade of integrin subunits (alpha1, alpha3, alpha5, and
beta1) on T cells resulted in less astrocytic MMP-9-induced expression.
Interestingly, in CNS tissues from neurological HTLV-I-infected patients, MMP-9
was detected in neural cells within the perivascular space, which is infiltrated
by mononuclear cells. Altogether, these data emphasize the importance of the MMP
TIMP axis in the complex interaction between the CNS and invading immune cells in
the context of virally mediated T cell activation.
PMID- 10679114
TI - Induction of chemokine secretion and enhancement of contact-dependent macrophage
cytotoxicity by engineered expression of granulocyte-macrophage colony
stimulating factor in human colon cancer cells.
AB - We investigated the role of tumor cell-derived GM-CSF in recruitment and
tumoricidal activation of tissue macrophages. Transfection of the murine GM-CSF
gene into KM12SM human colon cancer cells decreased the tumorigenicity of
transfected cells and nontransfected bystander colon cancer cells in nude mice.
Sequential tissue sections from sites injected with high GM-CSF-producing tumor
cells (but not from nontransfected or low GM-CSF-producing cells) demonstrated a
dense infiltration of polymorphonuclear cells (PMN), followed by infiltration of
macrophages, which correlated with expression of the macrophage-inflammatory
protein-1alpha and the monocyte chemoattractant protein-1 (MCP-1) in mouse PMN
and macrophages. GM-CSF-producing KM12SM cells were highly sensitive to lysis by
mouse macrophages and also increased macrophage-mediated lysis of bystander
nontransfected KM12SM cells. The incubation of macrophages with GM-CSF induced
expression of the CD11b surface adhesion molecule, which was associated with
increased attachment to tumor cells. All KM12SM cells were sensitive to
macrophage-mediated lysis in the presence of rGM-CSF and recombinant MCP-1.
Collectively, the results demonstrate that tumor cell-derived GM-CSF stimulates
PMN and macrophages to secrete macrophage-inflammatory protein-1alpha and MCP-1,
which triggers recruitment of mononuclear cells, induces expression of adhesion
molecules on macrophages, and enhances contact-dependent cytolysis of tumor
cells.
PMID- 10679115
TI - Expression and contribution of endogenous IL-13 in an experimental model of
sepsis.
AB - IL-13 has been shown to exert potent anti-inflammatory properties. In this study,
we elucidated the functional role of endogenous IL-13 in a murine model of septic
peritonitis induced by cecal ligation and puncture (CLP). Initial studies
demonstrated that the level of IL-13 increased in tissues including liver, lung,
and kidney, whereas no considerable increase was found in either peritoneal fluid
or serum after CLP. Immunohistochemically, IL-13-positive cells were Kupffer
cells in liver, alveolar macrophages in lung, and epithelial cells of urinary
tubules in kidney. IL-13 blockade with anti-IL-13 Abs significantly decreased the
survival rate of mice after CLP from 53% to 14% on day 7 compared with control.
To determine the potential mechanisms whereby IL-13 exerted a protective role in
this model, the effects of anti-IL-13 Abs on both local and systemic inflammation
were investigated. Administration of anti-IL-13 Abs did not alter the leukocyte
infiltration and bacterial load in the peritoneum after CLP but dramatically
increased the neutrophil influx in tissues after CLP, an effect that was
accompanied by significant increases in the serum levels of aspartate
transaminase, alanine transaminase, blood urea nitrogen, and creatinine. Tissue
injury caused by IL-13 blockade was associated with increases in mRNA and the
protein levels of CXC chemokines macrophage inflammatory protein-2 and KC as well
as the CC chemokine macrophage inflammatory protein-1alpha and the
proinflammatory cytokine TNF-alpha. Collectively, these results suggest that
endogenous IL-13 protected mice from CLP-induced lethality by modulating
inflammatory responses via suppression of overzealous production of inflammatory
cytokines/chemokines in tissues.
PMID- 10679116
TI - Pivotal role of CCR1-positive leukocytes in bleomycin-induced lung fibrosis in
mice.
AB - We have investigated the involvement of chemokine receptor CCR1-positive cells in
bleomycin-induced lung injury, a model of pulmonary fibrosis. After bleomycin
challenge in C57BL/6J mice, the expression of CCR1 mRNA increased and peaked at
day 7, which paralleled to the expression of its ligands, macrophage-inflammatory
protein-1 alpha and RANTES. Immunohistochemical study showed that CCR1-positive
cells accumulated in the interstitial inflammatory site. Furthermore, the
treatment of anti-CCR1 Ab significantly reduced the accumulation of inflammatory
cells and collagen deposition, resulting in dramatic improvement of survival.
These results suggest that CCR1-positive cells play significant roles in the
pathogenesis of pulmonary fibrosis subsequent to bleomycin-induced lung injury,
and that CCR1 could be a novel molecular target for intervention therapy against
pulmonary fibrosis.
PMID- 10679117
TI - Time-dependent loss of Mac-1 from infiltrating neutrophils in the reperfused
myocardium.
AB - Numerous studies have shown that polymorphonuclear neutrophils (PMNs) infiltrate
the myocardium immediately after reperfusion of infarcted tissue. Studies with
mAbs in vivo and cellular studies in vitro suggest that PMN-induced injury of the
cardiac myocyte involve Mac-1 adhesion to myocyte ICAM-1. In this study we
demonstrate that PMNs that have infiltrated the ischemic area begin to lose Mac-1
within the first 3 h. By the fifth hour of reperfusion, minimal CD11b staining is
seen on PMNs using immunostaining, whereas CD11a remained unchanged.
Immunoreactivity of postreperfusion cardiac lymph with R15.7 (anti-CD18) or MY904
(anti-CD11b) was positive in all animals but not for CD11a (R7.1), indicating a
specific loss of Mac-1. Immunoprecipitation with either R15.7 or MY904 resulted
in identical peptides (a doublet at 190 kDa and a band at 80 kDa), suggesting
that both alpha and beta subunits of Mac-1 heterodimer were released.
Immunoprecipitation of control PMN lysates revealed bands of 198 kDa and 91 kDa
slightly greater than those from the released Mac-1. An in vitro model of
homotypic aggregation showed a similar loss of Mac-1 from PMNs;
immunoprecipitates of the supernatant demonstrated peptide bands identical with
those found in postischemic cardiac lymph. The appearance of soluble Mac-1 in
vitro was prevented by anti-CD18 mAb, R15.7, and also by protease inhibition by
PMSF. Thus, in vivo and in vitro, activated PMNs lose Mac-1 in a process that may
be dependent upon adhesion and subsequent proteolysis.
PMID- 10679118
TI - IFN-gamma shapes immune invasion of the central nervous system via regulation of
chemokines.
AB - Dynamic interplay between cytokines and chemokines directs trafficking of
leukocyte subpopulations to tissues in autoimmune inflammation. We have examined
the role of IFN-gamma in directing chemokine production and leukocyte
infiltration to the CNS in experimental autoimmune encephalomyelitis (EAE).
BALB/c and C57BL/6 mice are resistant to induction of EAE by immunization with
myelin basic protein. However, IFN-gamma-deficient (BALB/c) and IFN-gammaR
deficient (C57BL/6) mice developed rapidly progressing lethal disease. Widespread
demyelination and disseminated leukocytic infiltration of spinal cord were seen,
unlike the focal perivascular infiltrates in SJL/J mice. Gr-1+ neutrophils
predominated in CNS, and CD4+ T cells with an activated (CD69+, CD25+) phenotype
and eosinophils were also present. RANTES and macrophage chemoattractant protein
1, normally up-regulated in EAE, were undetectable in IFN-gamma- and IFN-gammaR
deficient mice. Macrophage inflammatory protein-2 and T cell activation gene-3,
both neutrophil-attracting chemokines, were strongly up-regulated. There was no
induction of the Th2 cytokines, IL-4, IL-10, or IL-13. RNase protection assays
and RT-PCR showed the prevalence of IL-2, IL-3, and IL-15, but no increase in IL
12p40 mRNA levels in IFN-gamma- or IFN-gammaR-deficient mice with EAE. Lymph node
cells from IFN-gamma-deficient mice proliferated in response to myelin basic
protein, whereas BALB/c lymph node cells did not. These findings show a
regulatory role for IFN-gamma in EAE, acting on T cell proliferation and
directing chemokine production, with profound implications for the onset and
progression of disease.
PMID- 10679119
TI - IL-8 reduced tumorigenicity of human ovarian cancer in vivo due to neutrophil
infiltration.
AB - Paclitaxel is a frontline therapy for ovarian cancer. Our laboratory has shown
that paclitaxel induces IL-8, a member of the C-X-C family of chemokines, in
subsets of human ovarian cancer cells. However, the critical issue concerns the
biological significance of this chemokine in human ovarian cancer. To study the
influence of IL-8 on tumor growth, human ovarian cancer cell lines were
transfected with an expression vector for human IL-8 and tested for their ability
to form tumors in nude mice. IL-8 expression by the transfected cells did not
alter their growth properties in vitro. In contrast, tumor growth in vivo was
significantly attenuated in animals receiving IL-8-expressing cells when compared
with mice injected with control cells. As additional evidence that IL-8 is a
crucial factor in tumor growth, it was noted that ovarian cell lines in which
constitutive IL-8 expression is elevated did not form tumors. Injection of
neutralizing Ab to IL-8 reverted the phenotype and caused tumor growth in vivo.
Examination of tissue from the inoculation site revealed a dramatically elevated
cellularity, containing neutrophils and macrophages, in mice receiving IL-8
expressing tumor cells. These results suggest that IL-8 production by human
ovarian tumor cells can play a role in reducing the rate of tumor growth; this
effect may be mediated by the increased targeting of neutrophil and other
mononuclear cells to the tumor injection site. These studies indicate a role for
IL-8 in ovarian cancer control and suggest that chemotherapy-induced IL-8 may
have a positive role in controlling tumor growth.
PMID- 10679120
TI - Gene therapy for chronic relapsing experimental allergic encephalomyelitis using
cells expressing a novel soluble p75 dimeric TNF receptor.
AB - In a murine relapsing experimental allergic encephalomyelitis (EAE) model, gene
therapy to block TNF was investigated with the use of a retroviral dimeric p75
TNF receptor (dTNFR) construct. To effectively produce these TNF inhibitors in
vivo, a conditionally immortalized syngeneic fibroblast line was established,
using a temperature-sensitive SV40 large T Ag-expressing retrovirus. These cells
were subsequently infected with a retrovirus expressing soluble dTNFR. CNS
injected cells could be detected 3 mo after transplantation and were shown to
produce the transgene product by immunocytochemistry and ELISA of tissue fluids.
These levels of dTNFR protein were biologically active and could significantly
ameliorate both acute and relapsing EAE. This cell-based gene-vector approach is
ideal for delivering proteins to the CNS and has particular relevance to the
control of inflammatory CNS disease.
PMID- 10679121
TI - Accumulation of clonally related B lymphocytes in the cerebrospinal fluid of
multiple sclerosis patients.
AB - The accumulation of B lymphocyte clones in the cerebrospinal fluid (CSF) of
patients with multiple sclerosis (MS) and patients with other neurological
disorders was investigated using PCR technologies. Oligoclonal B cell
accumulations were detected in 10 of 10 MS patients, but only in 3 of 10 of the
patients with other neurological disorders. Analyses of the Ig V(D)J sequences on
the CSF from MS patients disclosed that VH3 and VH4 genes were extensively
mutated compared with germline sequences. Moreover, a substantial proportion of
the molecular clones analyzed shared the same third CDR of the H chain variable
region gene (HCDR3) and the same VH genes, albeit with different numbers and
locations of point mutations, thus indicating an ongoing process of intraclonal
diversification. A larger number of clonally related VH sequences could be
obtained by using a VH3 gene-specific PCR so that genealogical trees depicting
the process of diversification could be drawn. Analyses of the Ig V(D)J from the
CSF of a patient with viral meningitis and oligoclonal B cell accumulations
revealed that VH3 genes were extensively mutated. However, no intraclonal
diversification could be observed even using VH3 gene-specific PCR methodologies.
Clone-specific PCR and sequencing was used to detect the V(D)J found in the CSF
of one MS patient in the PBL of the same patient. Only 1/3 of the V(D)J sequences
investigated could be demonstrated in the PBL, indicating that the V(D)J genes
utilized by B cells in the CSF are much less represented in the PBL.
Collectively, the data suggest that in MS there is a compartmentalized clonal
expansion.
PMID- 10679122
TI - Naturally developing memory T cell xenoreactivity to swine antigens in human
peripheral blood lymphocytes.
AB - Naturally developing xenospecific Abs are well-documented barriers to xenograft
transplantation in humans, but whether analogous xenoreactive T cell immunity
develops is not known. We used an enzyme-linked immunospot assay to determine the
frequency and cytokine profiles of xenoreactive PBLs from a panel of human
volunteers. Because naive T cells produce only IL-2 in short term culture, IFN
gamma production by this approach is a measure of a memory immune response.
Stimulation of human PBLs or purified T lymphocytes with stimulator cells from
inbred swine revealed a high frequency of IFN-gamma producers with 5-fold fewer
IL-2 producers. In contrast, lymphocytes obtained from neonatal umbilical cord
blood contained swine-specific IL-2 producers but few IFN-gamma producers, which
is what one would expect to find with a naive phenotype. Moreover, PBLs from
adults with a history of abstention from pork consumption responded to swine
cells with a significantly lower frequency of IFN-gamma producers than PBLs from
adults with unrestricted diets did, suggesting that pork consumption may result
in priming of swine-specific T cell immunity. Our findings provide the first
evidence for naturally occurring xenospecific T cell immunity in humans. The
detected strength of this memory response suggests that it will present a
formidable barrier to transplantation of swine organs.
PMID- 10679123
TI - Systemic activation and antigen-driven oligoclonal expansion of T cells in a
mouse model of colitis.
AB - Transfer of CD4+CD45RBhigh T cells into immunodeficient mice results in both the
expansion of the transferred T cells and colitis. Here we show that colitis
pathogenesis requires expression of MHC class II molecules by the immune
deficient host. Analysis of the TCRbeta repertoire of the cells found in the
large intestine of diseased mice revealed a population with restricted TCR
diversity. Furthermore, nucleotide sequence analysis demonstrated the selection
for particular CDR3beta amino acid sequence motifs. Collectively, these data
indicate that the expansion of T cells in the intestine and colitis pathogenesis
are likely to require the activation of Ag-specific T cells, as opposed to
nonspecific or superantigen-mediated events. There is relatively little overlap,
however, when the TCR repertoires of different individuals are compared,
suggesting that a number of Ags can contribute to T cell expansion and the
generation of a T cell population in the intestine. Surprisingly, many of the
expanded clones found in the large intestine also were found in the spleen and
elsewhere, although inflammation is localized to the colon. Additionally, donor
derived T cells appear to be activated in both the intestine and the spleen at
early time points after cell transfer. Together, these results strongly suggest
that disease induction in this model involves either the early and systemic
activation of antigen-specific T cells or the rapid dispersal of T cells
activated at a particular site.
PMID- 10679124
TI - The human UTY gene encodes a novel HLA-B8-restricted H-Y antigen.
AB - The mammalian Y chromosome encodes male-specific minor histocompatibility (H-Y)
Ags that are recognized by female T cells in an MHC-restricted manner. Two human
H-Y epitopes presented by HLA-A2 and HLA-B7, respectively, have been identified
previously and both are derived from the SMCY gene. We previously isolated CD8+
CTL clones that recognized a male-specific minor histocompatibility Ag presented
by HLA-B8. In contrast to the SMCY-encoded H-Y epitopes, the B8/H-Y Ag was not
presented by fibroblasts from male donors, suggesting that it was encoded by a
novel gene. We now report that the HLA-B8-restricted H-Y epitope is defined by
the octameric peptide LPHNHTDL corresponding to aa residues 566-573 of the human
UTY protein. Transcription of the UTY gene is detected in a wide range of human
tissues, but presentation of the UTY-derived H-Y epitope to CTL by cultured human
cells shows significant cell-type specificity. Identification of this CTL-defined
H-Y epitope should facilitate analysis of its contribution to graft/host
interactions following sex-mismatched organ and bone marrow transplantation.
PMID- 10679125
TI - Analysis and significance of anti-latent membrane protein-1 antibodies in the
sera of patients with EBV-associated diseases.
AB - Anti-latent membrane protein-1 (LMP-1) is an EBV-encoded type III integral
membrane protein with oncogenic potential that is expressed most consistently in
various EBV-associated malignancies. Unlike many other EBV proteins, LMP-1 Abs
have rarely been demonstrated in EBV-associated disease conditions. We
established a high level LMP-1-expressing cell clone and used it for the
detection, quantitation, and characterization of these Abs in various human sera
in immunoblots and ELISA. Our results demonstrate that, in contrast to the
commonly held notion, LMP-1 induces significant humoral immune responses in EBV
associated malignant conditions especially in nasopharyngeal carcinoma (NPC)
patients in whom >70% sera are positive for these Abs, and their titers correlate
with the clinical condition of the tumors. Interestingly, anti-LMP-1 Abs of IgA
isotype were found only in NPC patients. These Abs were absent from the sera of
infectious mononucleosis and chronic EBV infection patients, whereas a small
fraction ( approximately 5%) of the healthy, EBV-seropositive individuals were
positive for them; however, their OD values were much lower than those of NPC
patients. These studies demonstrate, for the first time, the potential
significance of LMP-1-specific Abs for the diagnosis and prognosis of EBV
associated malignancies, especially of NPC.
PMID- 10679126
TI - Accumulation of common T cell clonotypes in the salivary glands of patients with
human T lymphotropic virus type I-associated and idiopathic Sjogren's syndrome.
AB - To clarify the pathogenesis of human T lymphotropic virus type I (HTLV-I)
associated Sjogren's syndrome (SS), the TCR Vbeta gene usage by the infiltrating
lymphocytes in the target organ was examined. The Vbeta families predominantly
used in the labial salivary gland (LSG) from the HTLV-I-seropositive (HTLV-I+) SS
patients were more restricted than those from the HTLV-I-seronegative
(idiopathic) SS patients, and were commonly Vbeta5.2, Vbeta6, and Vbeta7. The
single-strand conformation polymorphism analysis revealed that T cell clonotypes
with Vbeta5.2, Vbeta6, and Vbeta7 accumulate in the LSG from the HTLV-I+ and
idiopathic SS patients. Among junctional sequences of the most dominant Vbeta7
transcripts, the conserved amino acid motif (QDXG: X is any amino acid) was found
in six of the five HTLV-I+ SS patients and was also detected in two of the five
idiopathic SS patients. Using the probes specific to the motif, the Vbeta7
transcripts with the motif were detected in the LSG from all of the seven HTLV-I+
and five of the six idiopathic SS patients, but not from eight healthy subjects.
The Vbeta7 transcripts with this motif were also detected in the HTLV-I-infected
T cell lines obtained from the LSG of an HTLV-I+ SS patient. The accumulation of
HTLV-I-infected T cells expressing TCR with the conserved motif was thus
indicated. These T cells were commonly present in patients with idiopathic SS and
are strongly suggested to most likely be involved in the pathogenesis of both
HTLV-I-associated and idiopathic SS.
PMID- 10679128
TI - Correction
PMID- 10679127
TI - High levels of IL-17 in rheumatoid arthritis patients: IL-15 triggers in vitro IL
17 production via cyclosporin A-sensitive mechanism.
AB - Recent data suggest that IL-15 plays an important role in the pathogenesis of
rheumatoid arthritis. In the present study, we hypothesized that elevated in the
joints of rheumatoid arthritis, but not osteoarthritis, patients, IL-15 may exert
its proinflammatory properties via the induction of IL-17, a cytokine known to
stimulate synoviocytes to release several mediators of inflammation including IL
6, IL-8, GM-CSF and PGE2. To test this hypothesis, we first measured the levels
of IL-17 and IL-15 using specific ELISA and found that synovial fluids of
patients with rheumatoid arthritis, but not with osteoarthritis, contain high
levels of these cytokines. A strong correlation between IL-15 and IL-17 levels in
synovial fluids was observed. Among tested factors, LPS and TNF-alpha failed, IL
15 and IL-2 were equipotent, and PMA + ionomycin was far more efficient in the
induction of IL-17 secretion by PBMCs isolated from healthy blood donors.
Interestingly, synovial fluid cells, in contrast to PBMCs isolated from patients
with rheumatoid arthritis, but not osteoarthritis, respond to PMA + ionomycin
with much lower, comparable to IL-15-triggered IL-17 secretion. Moreover, PMA +
ionomycin-triggered IL-17 secretion is completely or partially blocked in the
presence of low doses of cyclosporin A or high doses of methylprednisolone,
respectively. IL-15-triggered IL-17 secretion by PBMCs was completely inhibited
by these drugs. Thus, our results suggest for the first time that IL-15 may
represent a physiological trigger that via cyclosporin A and steroid sensitive
pathways leads to the overproduction of IL-17 in the joints of rheumatoid
arthritis patients.
PMID- 10679130
TI - Effect of a comprehensive infection control program on the incidence of
infections in long-term care facilities.
AB - BACKGROUND: Control of infection within the long-term care facility is a daunting
problem. Elderly patients are at high risk for contracting infection because of
reduced innate immunity, malnutrition, and the presence of chronic medical
conditions. This small study tested the effect of developing and implementing a
comprehensive preventive infection control program in the long-term care setting
and examined the resultant incidence of infections. METHODS: Eight private,
freestanding, long-term care facilities in urban and suburban settings were
selected for the study. The 4 test sites had a total of 443 beds; there were 447
beds in 4 matched control sites. Data on infection rates were accrued in both
preintervention and intervention years. The control homes maintained their
existing infection control policies and procedures. The test homes were provided
with an infection control educational program and replaced all currently used
germicidal products with single-branded products for a 12-month period. A
criteria-based standardized infection control surveillance system was used to
monitor and report infections in all facilities. RESULTS: In the preintervention
year, the test sites experienced 743 infections (incidence density rate, 6.33)
and the control homes experienced 614 infections (incidence density rate, 3.39).
In the intervention year, the test homes reported 621 infections, a decrease of
122 infections (incidence density rate, 4.15); in the control homes, the number
of infections increased slightly, to 626 (incidence density rate, 3.15). The
greatest reduction in infections in the test homes was in upper respiratory
infections (P =.06). CONCLUSIONS: This study provides additional evidence that a
comprehensive infection control program that includes handwashing and
environmental cleaning and disinfecting may help reduce infections among the
elderly residing in long-term care settings.
PMID- 10679131
TI - Microbiologic survey of long-term care facilities.
AB - BACKGROUND: We undertook a microbiologic survey of long-term care facilities to
categorize bacteria found in cultures of residents. Culture and sensitivity data
were collected on 566 samples from indwelling bladder catheters, percutaneous
gastrostomy tubes, nares, stool, wounds, pressure ulcers, and tracheostomies in
25 Nebraska and Iowa facilities. Information was also collected on resident
factors (eg, presence of indwelling urinary catheter, prior antibiotic
administration) and institutional variables (eg, number of beds, nosocomial
infection rates). RESULTS: There were 478 gram-negative isolates, the leading
organisms being Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, and
Klebsiella pneumoniae. There were 221 gram-positive isolates, the most frequently
seen of which were enterococci and Staphylococcus aureus. Of the 442 residents
sampled in the study, 168 (38%) were taking, or had within the previous month
been taking, a systemic antibiotic. Quinolones were the most frequently
prescribed antibiotic class. The institutional prevalence of urinary
catheterization averaged 6.7%. CONCLUSIONS: Significant antibiotic pressure
exists in long-term care facilities, a fact that is reflected in antibiotic
resistance patterns. A variety of gram-positive and gram-negative bacteria were
found in nursing home culture specimens.
PMID- 10679132
TI - Surgical site infections at the National Cancer Institute in Mexico: a case
control study.
AB - OBJECTIVES: To quantify the surgical infection rate and to identify risk factors
associated with surgical site infection. METHODS: We conducted a case-control
study of all surgical patients between January 1, 1993, and June 30, 1994. The
frequency of surgical site infection per 100 surgeries was calculated. The odds
ratio (OR) was estimated by using logistic regression analysis. SETTING: A 130
bed tertiary-care teaching hospital for adult patients with cancer. RESULTS: The
study followed 3372 surgeries. Three hundred thirteen patients had a surgical
site infection (rate per 100 surgeries: 9. 30). The risk factors associated with
surgical site infection were diabetes mellitus (OR = 2.5, 95% confidence interval
[CI] = 1.27-4. 91), obesity (OR = 1.76, 95% CI = 1.14-2.7), presence of surgical
drains for >5 and <16 days (OR = 1.84, 95% CI = 1.02-3.31), and presence of
surgical drains for >/=16 days (OR = 2.14, 95% CI = 1. 0-4.6). The bacteria most
frequently isolated were Escherichia coli 38 (21.8% of the total of
microorganisms found), Pseudomonas sp 22 (12.6%), Staphylococcus aureus 16
(9.2%), and coagulase-negative Staphylococcus 25 (13.6%). The coexistence of
other nosocomial infections was greater among the cases (OR = 1.8, 95% CI = 1.1
3.1) than in the control group. CONCLUSIONS: The surgical site infection rate in
our hospital is slightly higher than the rates reported for general hospitals.
The risk factors associated with surgical site infection are similar to those
previously reported. Diabetes mellitus, obesity, and prolonged presence of a
surgical drain increased the risk of infection.
PMID- 10679133
TI - Survey on attitudes toward HIV-infected individuals and infection control
practices among dentists in Mexico City.
AB - BACKGROUND: The teaching of infection control is gradually being introduced at
dental schools in Mexico. However, most practicing dentists have limited access
to current infection control standards. Deficiencies of knowledge with regard to
blood-borne pathogens such as HIV and hepatitis B virus may influence attitudes
toward infected individuals and reduce compliance with infection control
recommendations. OBJECTIVE: The purpose of this study was to assess (1) attitudes
toward HIV-infected patients and hepatitis B virus-infected patients and (2)
infection control knowledge and practices among dental practitioners in Mexico
City. METHOD: A total of 196 dentists were interviewed by means of a
questionnaire with Likert-type scales and open-ended questions (response rate,
86.1%). RESULTS: Most respondents had no previous social or professional contact
with HIV-positive individuals. Nine percent indicated that they had knowingly
treated HIV-positive patients. Perceived professional and moral obligations to
treat HIV-positive patients were high. Thirty-five percent of the respondents
perceived the risk of HIV infection as "considerable" to "very strong." The risk
of hepatitis B infection was considered significantly higher than the risk of HIV
infection (P <.01); however, 78% of the respondents had not been immunized
against hepatitis B. Reported use of personal protective equipment was high. Most
respondents used dry heat sterilization. The principal disinfectants used were
quaternary ammonium compounds, bleach, and glutaraldehyde. Fifty-four percent of
the respondents acknowledged that clinical precautions reduced occupational
risks. CONCLUSIONS: This survey revealed contradictory attitudes toward HIV
positive individuals and limited understanding of infection control
recommendations. Educational and regulatory efforts are needed to promote better
adherence to current infection control standards.
PMID- 10679134
TI - Watching the bottom line: enhancing the role and impact of infection control in a
managed care environment.
AB - Health care expenditures exceeded $1 trillion in 1997, with projections for $2.2
trillion in expenditures by 2008. Decreasing organizational revenues and efforts
to reduce operating costs have had a direct impact on infection control programs.
Senior managers in hospitals and other provider organizations are focusing on
achieving and maintaining revenues while controlling costs. Infection control
professionals must align themselves and their programs with these organizational
goals by (1) identifying areas in which the infection control program can support
and enhances revenues, (2) facilitating the avoidance of excess costs for care,
especially those related to nosocomial infection, (3) identifying opportunities
for cost reduction through value analysis, and (4) participating in efforts to
measure and prevent other adverse outcomes of care.
PMID- 10679135
TI - The fifth evolutionary era in infection control: interventional epidemiology.
AB - A historical review of infection control over the last 4 decades indicates that
the field has evolved from being one whose investigative work laid the foundation
for understanding the chain of infection to an influential profession whose
research on effective prevention methods have revoluntionized clinical practice
throughout the world. Underlying our successes is the fact that growth in the
profession has brought with it an enormous expansion in responsibilities, which
in turn has impacted, in some cases severely, the personnel and time resources of
infection control departments. At the same time, the economic pressures brought
on by the upheavals in the business of health care have trickled down wherein it
now influences the makeup and effectiveness of infection control programs. To
continue with our mission of reducing morbidity and mortality, and perhaps to
avoid a diminishing of our own professional influence, it will become essential
that new approaches to the management of infection control programs be
implemented. The approach must start by incorporating a basic mandate for change
in the infection control professional.
PMID- 10679136
TI - Reengineering and infection control programs: commentary and a case study.
AB - Transformation of the health care system has been an ongoing process for
generations, but many changes in the past 2 decades have focused on reducing
costs in concert with rapidly changing technologies and demands for high quality
care. Many cost-containment efforts in the 1990s are characterized by attempts to
apply the business model for "reengineering the corporation" to health care
systems. This commentary reviews principles of reengineering and how strategies
to reduce costs through market forces, competition, and downsizing can result in
substantial problems for bureaucratic organizations unaccustomed to rapid change
and innovation. A case study drawn from experiences of a large metropolitan
academic health care system is presented, with specific focus on lessons that
will be helpful to infection control professionals (ICPs) confronted with similar
situations.
PMID- 10679137
TI - Effect of a comprehensive program to reduce infectious waste.
PMID- 10679138
TI - Direct costs associated with a nosocomial outbreak of Salmonella infection: an
ounce of prevention is worth a pound of cure.
AB - BACKGROUND: Nosocomial outbreaks of Salmonella infections in Australia are an
infrequent but significant source of morbidity and mortality. Such an outbreak
results in direct, measurable expenses for acute care management, as well as
numerous indirect (and less quantifiable) costs to those affected, the hospital,
and the wider community. This article describes the significant direct costs
incurred as a result of a nosocomial outbreak of Salmonella infection involving
patients and staff. METHOD: Information on costs incurred by the hospital was
gathered from a number of sources. The data were grouped into 4 sections (medical
costs, investigative costs, lost productivity costs, and miscellaneous) with use
of an existing tool for calculating the economic impact of foodborne illness.
RESULTS: The outbreak cost the hospital more than AU $120, 000. (US $95,000).
This amount is independent of more substantial indirect costs. CONCLUSION:
Salmonella infections are preventable. Measures to aid the prevention of costly
outbreaks of nosocomial salmonellosis, although available, require an investment
of both time and money. We suggest that dedication of limited resources toward
such preventive strategies as education is a practical and cost-effective option
for health care facilities.
PMID- 10679139
TI - Expanding the role of the infection control professional in the cost-effective
use of antibiotics.
AB - There is a growing demand that health care expenses be contained and that
excessive and inappropriate use of antibiotics be eliminated. At the University
of California, San Diego Medical Center, strategies aimed at controlling drug
usage and subsequently reducing costs have been implemented and found to be
effective. Mechanisms designed to achieve such goals without diminishing quality
of care involve expanding the role of the infection control professional (ICP)
while implementing antibiotic control stratagems such as antimicrobial
utilization teams, antibiotic order sheets, audits of use, automatic stop orders,
computer-assisted management, drug use reviews, educational efforts, formulary
practice, restricted drug policies, and target drug monitoring. The infection
control professional, as well as other members of the antimicrobial utilization
team, contributes to the promotion of the appropriate use of antibiotics in part
by identifying individual cases in which antibiotics might be used
inappropriately, such as for the treatment of colonization rather than infection
or when appropriate microbiologic testing has not been carried out.
PMID- 10679140
TI - "Where's the science"?
PMID- 10679141
TI - Clinical and economic consequences of nosocomial catheter-related bacteriuria.
AB - Indwelling catheters are strongly associated with the development of bacteriuria,
which can lead to significant morbidity in hospitalized patients. This report, a
review of the literature, evaluates the infectious outcomes of patients with
indwelling catheters to determine the precise clinical and economic impact of
catheter-related infection. Statistical pooling was used to estimate the
incidence of bacteriuria in hospitalized patients with indwelling catheters. In
addition, the proportion of patients with catheter-related bacteriuria in whom
symptomatic urinary tract infection and bacteremia will develop was estimated
through quantitative synthesis of previous reports. Costs were estimated by using
microcosting techniques. Of patients who have indwelling catheters for 2 to 10
days, bacteriuria is expected to develop in 26% (95% confidence interval [CI],
23% to 29%). Among patients with bacteriuria symptoms of urinary tract infection
will develop in 24%, (95% CI, 16% to 32%), and bacteremia from a urinary tract
source will develop in 3.6% (95% CI, 3.4% to 3.8%). Each episode of symptomatic
urinary tract infection is expected to cost an additional $676, and catheter
related bacteremia is likely to cost at least $2836. Given the clinical and
economic burden of urinary catheter-related infection, infection control
professionals and hospital epidemiologists should use the latest infection
control principles and technology to reduce this common complication.
PMID- 10679142
TI - Gastrointestinal hormones.
AB - Solomon A. Berson, M.D., the first Murray M. Rosenberg Professor and Chair of the
Department of Medicine at Mount Sinai from 1968 until his death in 1972, and
Rosalyn S. Yalow, Ph.D., 1977 Nobel Laureate in Medicine or Physiology and
Solomon A. Berson Distinguished Professor-at-Large, brought meticulous
quantitation and new vistas to all of clinical medicine and biomedical science
through the application of their technique of radioimmunoassay. I was fortunate
to know and work with them for many years. In 1972, while I was an NIH Fellow in
gastroenterology at Mount Sinai, Dr. Berson suggested that I pursue my research
in their laboratory at the Bronx Veterans Administration Hospital. Dr. Berson
died one month after I began my research in the Bronx. Yalow and Berson had
already discovered big gastrin (G-34), but much work with gastrin remained to be
done. Challenging work with secretin, cholecystokinin, and a host of other gut
peptides, would keep the Mount Sinai group at the forefront of this exciting
field.
PMID- 10679144
TI - Robert Jackson Williams (1931-1999).
PMID- 10679145
TI - Cryopreservation of mouse oocytes using a medium with low sodium content: effect
of plunge temperature.
AB - The effect of various combinations of plunge temperature and thawing protocol on
the survival and viability of mouse oocytes was examined. The oocytes were frozen
either in a standard freezing medium (ETFM, embryo transfer freezing medium) or
in a low-sodium, choline-based freezing medium (CJ2), with 1.5 M 1,2-propanediol
and 0.1 M sucrose, and using a conventional slow cooling method. The criteria
used to assess survival were morphological state after thawing (intact or lysed),
ability to become fertilized, and ability to develop to the two-cell, morula, and
blastocyst stage in vitro. Oocytes frozen in CJ2 and plunged into liquid nitrogen
(LN(2)) from -10, -20, or -33 degrees C remained intact and developed to the
blastocyst stage at significantly higher rates than oocytes frozen in ETFM. For
oocytes plunged into LN(2) from -33 degrees C, very rapid thawing (10 s in 30
degrees C water) was more detrimental than rapid or slow thawing (holding in air
at room temperature for 10 or 30 s, respectively, prior to submersion in water at
30 degrees C for 10 s). By contrast, oocytes plunged into LN(2) from -10 or -20
degrees C survived better when thawing was very rapid or rapid than when thawing
was slow. With the current protocol CJ2 was very effective over a wide range of
plunge temperatures (-20 to -33 degrees C), although the optimal thawing protocol
depended on the particular plunge temperature. Over 90% of oocytes surviving
after slow cooling in CJ2 to -33 degrees C could be plunged to -196 degrees C
with little or no further damage.
PMID- 10679146
TI - Rapid MR imaging of cryoprotectant permeation in an engineered dermal
replacement.
AB - Magnetic resonance (MR) imaging is a powerful technique for monitoring the
permeation of cryoprotective agents (CPAs) inside tissues. However, the
techniques published until now suffer from inherently long imaging times,
limiting the application of these techniques to slow diffusion processes and
large CPA concentrations. In this study, we present a rapid MR imaging technique
based on a CHESS-FLASH scheme combined with Keyhole image acquisition. This
technique can image the fast permeation of Me(2)SO solutions into freeze-dried
artificial dermal replacements for concentrations down to 10% v/v. Special
attention is given to evaluating the technique for quantitative analysis.
PMID- 10679147
TI - Effect of phospholipase A2 inhibitors on the release of arachidonic acid and cell
viability in cold-stored hepatocytes.
AB - We investigated the effect of phospholipase A(2) (PLA(2)) inhibitors on PLA(2)
activity and cell viability in cold-stored rat hepatocytes. The cells were
radiolabeled with [(3)H] arachidonic acid (AA) and cold stored in the University
of Wisconsin (UW) solution containing various PLA(2) inhibitors. PLA(2) activity
was determined by measuring the total free (cellular + supernatant) AA by thin
layer chromatography after inhibiting reacylation of free AA with inhibitors of
energy production (carbonyl cyanide m-chlorophenylhydrazone + iodoacetate).
Aristolochic acid, chlorpromazine, and quinacrine in the UW solution showed a
significant inhibitory effect throughout 48 h cold storage but only at relatively
high concentration. PLA(2) activity was also suppressed (58% of control) by
trifluoperazine (50 microM), but its effect was limited to only 24 h. In
contrast, pretreatment of the cells prior to hypothermic preservation with
trifluoperazine (10 to 100 microM) suppressed PLA(2) activity during 48 h
storage. Inclusion of calmodulin antagonist W-7 did not affect PLA(2) activity.
Thus, the inhibitory activity of these agents appears unrelated to Ca-calmodulin
phospholipid interaction but to have an inhibitory effect on PLA(2) activity. To
study the effects of PLA(2) inhibitors on cell viability, lactate dehydrogenase
(LDH) release was measured in the presence or absence of inhibitors upon
rewarming cold-stored cells in Krebs-Henseleit buffer for 2 h at 37 degrees C.
None of the inhibitors tested improved cell viability after 48 h storage. Thus,
although PLA(2) inhibitors blocked PLA(2) activity, there was no suppression of
LDH release. PLA(2) may play a minor role in preservation/reperfusion injury to
cold-stored hepatocytes.
PMID- 10679148
TI - Fertilizing potential of mouse spermatozoa cryopreserved in a medium containing
whole eggs.
AB - Experiments were conducted to improve survival of mouse spermatozoa through the
cryopreservation process. In the first experiment, percentages of motile
spermatozoa and fertilizing capacities of spermatozoa were evaluated when mouse
spermatozoa were cryopreserved using three previously reported cryopreservation
media: (1) 18% raffinose in 3% skim milk; (2) Tes/Tris medium containing 25% egg
yolk and 1.25% glycerol; and (3) PBS containing 18% raffinose and 1.75% glycerol,
each at three different cooling rates (-3, -10, and -50 degrees C/min).
Spermatozoa frozen in the skim milk/raffinose medium exhibited the highest
percentage of motile spermatozoa (39%) when cells were frozen at -10 degrees
C/min (P<0.05). The second experiment evaluated the effects of modifying the
Tes/Tris/egg yolk medium, comparing different concentrations of egg yolk, BSA,
and sodium dodecyl sulfate. Reducing egg yolk from 25% of the medium volume to
5%, increased percentages of motile spermatozoa after cryopreservation from 29 to
36% (P<0.05). Addition of 1% BSA and sodium dodecyl sulfate to medium containing
5% egg yolk further improved percentages of motile spermatozoa after freezing. In
the final experiment, 20% whole egg was substituted for 5% egg yolk and 1% BSA
used in previous experiments and resulted in percentages of motile spermatozoa
(51%) equal to that of the skim milk-raffinose medium. However, fertility rates
were higher (68%) than for spermatozoa frozen in the skim milk-raffinose medium
(P < 0.05) and were comparable to the fertility rates of fresh spermatozoa (77%;
P>0.05). In conclusion, freezing mouse spermatozoa in a medium containing 20%
whole egg, 0.035% sodium dodecyl sulfate, and 1.25% glycerol using a cooling rate
of -10 degrees C/min preserves the motility and fertilization capacity of mouse
spermatozoa.
PMID- 10679149
TI - Cryopreservation of seabream (Sparus aurata) spermatozoa.
AB - The aim of this research was to optimize protocols for freezing spermatozoa of
seabream (Sparus aurata). All the phases of the cryopreservation procedure
(sampling, choosing the cryoprotective extender, cooling, freezing, and thawing)
were studied in relation to the species of spermatozoa under examination, so as
to be able to restore on thawing the morphological and physiological
characteristics of fresh semen. Seabream spermatozoa were collected by stripping
and transported to the laboratory chilled (0-2 degrees C). Five cryoprotectants,
dimethyl sulfoxide (Me(2)SO), ethylene glycol (EG), 1,2-propylene glycol (PG),
glycerol, and methanol, were tested at concentrations between 5 and 15% by volume
to evaluate their effect on the motility of semen exposed for up to 30 min at 26
degrees C. The less toxic cryoprotectants, 10% EG, 10% PG, and 5% Me(2)SO,
respectively, were added to 1% NaCl to formulate the extenders for freezing. The
semen was diluted 1:6 with the extender, inserted into 0.25-ml plastic straws by
Pasteur pipette, and frozen using a cooling rate of either 10 or 15 degrees C/min
to -150 degrees C followed by transfer and storage in liquid nitrogen (-196
degrees C). The straws were thawed at 15 degrees C/s. On thawing, the best
motility was obtained with 5% Me(2)SO, although both 10% PG and EG showed good
results; no differences were found between the two freezing gradients, although
semen frozen with the 10 degrees C/min gradient showed a slightly higher and more
prolonged motility.
PMID- 10679150
TI - Cell-cell contact affects membrane integrity after intracellular freezing.
AB - The response of cells to freezing depends critically on the presence of an intact
cell membrane. During rapid cooling, the cell plasma membrane may no longer be an
effective barrier to ice propagation and can be breached by extracellular ice
resulting in the nucleation of the supercooled cytoplasm. In tissues, the
formation of intracellular ice is compounded by the presence of cell-cell and
cell-surface interactions. Three different hamster fibroblast model systems were
used to simulate structures found in organized tissues. Samples were supercooled
to an experimental temperature on a cryostage and ice nucleated at the constant
temperature. A dual fluorescent staining technique was used for the quantitative
assessment of the integrity of the cell plasma membrane. A novel technique using
the fluorescent stain SYTO was used for the detection of intracellular ice
formation (IIF) in cell monolayers. The cumulative incidence of cells with a loss
of membrane integrity and the cumulative incidence of IIF were determined as a
function of temperature. Cells in suspension and individual attached cells showed
no significant difference in the number of cells that formed intracellular ice
and those that lost membrane integrity. For cells in a monolayer, with cell-cell
contact, intracellular ice formation did not result in the immediate disruption
of the plasma membrane in the majority of cells. This introduces the potential
for minimizing damage due to IIF and for developing strategies for the
cryoprotection of tissues during rapid cooling.
PMID- 10679151
TI - A two-parameter model of cell membrane permeability for multisolute systems.
AB - A two-parameter model of cell osmotic response (F. W. Kleinhans, 1998,
Cryobiology 37, 271-289) is expanded for multisolute systems. The cell water
volume W and intracellular osmolalities of N solutes are related as W[1 +
L(p)RTSigma(N)(i=1)(M(i)/P(i))] = W(0)[1 + L(p)RTSigma(N)(i=1)(M(0)i)/P(i))],
where M(i) is the intracellular osmolality of the ith solute (i = 1 ellipsis N),
P(i) is the membrane permeability of the ith solute, L(p) is the membrane
hydraulic conductivity, R is the gas constant, T is the absolute temperature, and
the subscript "0" denotes the initial values at time zero. The above formula
allows calculating the final (equilibrium) volume when all entities are
permeable. Simple algebraic expressions for calculation of the number and
magnitude of transient maximum volume excursions are presented. These simple
expressions can all be calculated by hand on a pocket calculator. Practical
examples of one-, two-, and three-solute systems are discussed. Special attention
has been given to situations when systems contain an impermeable component. All
formulas are simple to use for optimization of variety of cryobiological
protocols. Application of the theory for optimization of addition and dilution of
a permeable cryoprotectant is also discussed.
PMID- 10679152
TI - Transplantation of mammalian livers following freezing: vascular damage and
functional recovery.
AB - We transplanted rat livers cryopreserved at high subzero temperatures with a
protocol that mimics freezing in freeze-tolerant animals. The results of nine
transplants show that: (a) every single transplanted liver produced bile, which
suggests that the cryopreserved livers retained some physiological function; (b)
eight of the animals survived between 2 and 4 h with loss of microvascular
integrity which suggests that transplantation failure is related to the
circulation and tests of bile production are not indicative of transplantation
success; and (c) one animal survived for 5 days with an intact circulation which
might be due to an unidentified technical variation or could indicate that when
the circulation recovers animals with transplanted livers survive.
PMID- 10679153
TI - Molecular phylogeny of north mediterranean freshwater barbs (genus Barbus:
cyprinidae) inferred from cytochrome b sequences: biogeographic and systematic
implications.
AB - We investigated phylogenetic relationships among north Mediterranean species of
the genus Barbus using sequences of the cytochrome b gene. Our results indicate
that the species belong to two major clades that are consistent with those
previously defined from morphological features. The first clade includes species
ranging from France to the Black Sea. In this clade, there is a well-supported
monophyletic group of large-sized fluvio-lacustrine barbs; however, the monophyly
of the small-sized rheophilic species is not clear. The second clade comprises
species found in Spain, Greece, and Asia Minor and probably represents the oldest
group present in the north Mediterranean rivers. In general, there is good
concordance between geography and phylogenetic relationships. These results are
compared to those from previous morphological- and allozyme-based studies and
demonstrate widespread discordance and polyphyly in the traditional taxonomy of
the genus Barbus. This study is one of the first reporting the phylogenetic and
biogeographic relationships of a genus that is widely distributed in European
rivers and contains species that are a major component of the European
ichthyofauna.
PMID- 10679154
TI - An 18S rDNA-based molecular phylogeny of aphidiinae (Hymenoptera: braconidae).
AB - We have obtained a molecular phylogeny of the subfamily Aphidiinae (Hymenoptera:
Braconidae) by sequencing the 18S rDNA in 37 aphidiine taxa. Approximately 1857
nucleotides were sequenced in each species. Evolutionary relationships were
established by comparing the results of maximum-parsimony, maximum-likelihood,
and distance analyses. The most variable region of this gene, V4 (approx 403
nucleotides), was employed to establish the basality of the tribe Ephedrini
within this subfamily. All phylogenetic reconstructions yielded trees with very
similar topologies that confirmed the existence of two of the four traditionally
accepted tribes, Ephedrini and Praini, but questioned the existence of Trioxini
and Aphidiini. To better ascertain the status of some groups, the same analyses
were repeated with a reduced taxonomic sample in which some species that produced
systematic errors in the former phylogenetic reconstructions had been removed.
The results from this second analysis favor either the three-tribes hypothesis
(Ephedrini, Praini, and Aphidiini) or a new classification with at least five
tribes (Ephedrini, Praini, Monoctonini, Trioxini, and Aphidiini). The 18S rDNA
gene is a useful marker to recover relationships not only at the tribe but also
at the subtribe and genus levels in this group. The natural status of some
traditionally accepted clusters is also corroborated with the present data
whereas the placement of other clusters is questioned or remains unresolved.
PMID- 10679155
TI - Molecular phylogenetics of subfamily Calamoideae (Palmae) based on nrDNA ITS and
cpDNA rps16 intron sequence data.
AB - Phylogenetic relationships among the 22 genera of the palm subfamily Calamoideae
were investigated using DNA sequence data from the nuclear ribosomal internal
transcribed spacer (ITS) region and the chloroplast rps16 intron. The rps16
intron displayed low levels of variation, corroborating previous reports that the
chloroplast genome of palms is highly conserved. High levels of within-individual
polymorphism were identified in the ITS region, indicating that concerted
evolution is not effectively homogenizing the ITS repeats. In the majority of
cases, multiple clones from individuals resolved as monophyletic. However, the
high levels of homoplasy in the ITS dataset, along with generally poor jackknife
support for many clades, led to concerns that topologies obtained from these data
might be unreliable. Nevertheless, congruence between trees based on ITS data
alone and those based on rps16 intron data was high. Simultaneous analyses of
both datasets yielded well-resolved topologies with high levels of jackknife
support. A number of exciting groups emerged from the analyses: the African
rattan clade comprising the endemic African rattan genera Laccosperma,
Eremospatha, and Oncocalamus; the Lepidocaryeae-Raphia clade comprising the fan
leaved New World tribe Lepidocaryeae and the African genus Raphia; and the Asian
clade comprising all Asian genera except Eugeissona. The position of Eugeissona
was variable, although it did not resolve inside any of the three major clades
mentioned above.
PMID- 10679156
TI - Molecular phylogenetics of Calamus (Palmae) and related rattan genera based on 5S
nrDNA spacer sequence data.
AB - Phylogenetic relationships among the rattan palm genera Calamus, Daemonorops,
Ceratolobus, Calospatha, Pogonotium, and Retispatha were investigated using DNA
sequences from the nontranscribed spacer of 5S nrDNA. Moderate levels of
intragenome polymorphism were identified, indicating that concerted evolution is
not completely homogenizing the multiple copies of the 5S nrDNA repeat present in
the nuclear genome. The existence of intragenome polymorphism did not excessively
interfere with phylogeny reconstruction because, in the majority of cases,
multiple clones obtained from individual species were resolved as monophyletic
groups. The highly speciose genus Calamus was found to be nonmonophyletic with
all five remaining genera being embedded within it. A number of major lineages
within Calamus were resolved, one of which included the monotypic genus
Calospatha, another included the monotypic genus Retispatha, and a third included
a monophyletic group comprising Daemonorops, Ceratolobus, and Pogonotium. While
the findings indicate that generic circumscriptions require revision, a
nomenclatural solution was not sought at this stage because inadequate sampling
and lack of support at basal nodes suggested that the topologies obtained might
not be entirely reliable. Under these circumstances, name changes to such an
important group would be both unhelpful and irresponsible.
PMID- 10679157
TI - Study of the evolutionary relationships among Limonium species (Plumbaginaceae)
using nuclear and cytoplasmic molecular markers.
AB - The genus Limonium, due to the patchiness of the natural habitats of its species
as well as the high frequency of hybridization and polyploidy and the possibility
of reproduction by apomixis, provides an example of all the principal mechanisms
of rapid speciation of plants. As an initial study of evolution in this genus, we
have analyzed intra- and interspecific variability in 17 species from section
Limonium, the largest in the genus, based on RFLPs of cpDNA and nuclear rDNA ITS
sequences. In the cpDNA analysis, 21 restriction enzymes were used, resulting in
779 fragments, 490 of which were variable and 339 parsimony informative. L.
furfuraceum exhibited two relatively divergent cpDNA haplotypes. The
relationships found among the species based on cpDNA restriction fragments were
coincident using different methods of phylogenetic analysis. Due to the presumed
reticulate evolution in the genus Limonium, the comparison of these results with
data from the nuclear DNA was necessary; ITS sequences were analyzed. The final
alignment contained 488 characters, of which 198 were variable and 156 parsimony
informative. Two relatively divergent ITS types were present at the
intraindividual level in L. delicatulum, a triploid species. Each type was
related to ITS from different groups of diploid Limonium species, one with a base
haploid chromosome number n = 8 (represented by L. cossonianum) and the other
with n = 9 (represented by L. minutum). The different phylogenetic inference
methods used for the analysis of ITS sequences rendered very similar topologies.
In general, the relationships among the species studied were coincident with
those obtained with the chloroplast genome. Both nuclear and cytoplasmic markers
support the polyphyly of section Limonium, with at least two species, L.
narbonense and L. vulgare, clearly divergent from the rest. Moreover, the
remaining subsections into which section Limonium is currently divided seem to be
artificial.
PMID- 10679158
TI - A new molecular phylogenetic hypothesis for the evolution of freshwater eels.
AB - Phylogenetic analysis of a segment of the mitochondrial 16S rDNA of eight
Anguilla species from the Indo-Pacific region and from the North Atlantic
revealed that the genus Anguilla appears to be surprisingly young, based upon the
small observed maximum genetic distance of 4.8% and the high degree of
morphological similarity among the species. The placement of A. marmorata as the
most ancestral lineage suggests that the genus is likely to have originated in
the Indo-Malayian region, from which it quickly spread. Two Pacific species, A.
obscura and A. japonica, branched next. A. japonica was placed as sister group to
all remaining species, which formed three clades: the first comprising A.
australis, the second A. reinhardti and A. mossambica, and the third A. anguilla
and A. rostrata. All analyzed specimens of A. rostrata originating from southern
New Jersey to Nova Scotia had identical mitotypes, while five mitochondrial
genotypes were found in Europe differing by zero to two substitutions. The two
Atlantic eel species are very closely related; all surveyed specimens of A.
anguilla differ by three to five substitutions from their American allies,
corroborating the existence of two distinct biological species. This was also
confirmed by restriction analysis of a 350-bp segment of the cytochrome b, in
which American specimens were distinct in sharing a single diagnostic restriction
site of HinfI. Our results suggest little to no gene flow between the two nominal
Atlantic eel species.
PMID- 10679159
TI - DNA archives and our nearest relative: the trichotomy problem revisited.
AB - Ever since Thomas H. Huxley correctly identified the chimpanzee and the gorilla
as the two closest relatives of the human, the problem of the relationship among
the three species ("the trichotomy problem") has remained unresolved. Comparative
morphology and other classical methods of biological investigation have failed to
answer definitively whether the chimpanzee or the gorilla is the closest relative
of the human species. DNA sequences, both mitochondrial and nuclear, too, have
provided equivocal solutions, depending on the region of the genome analyzed.
Random sorting of ancestral allelic lineages, sequence convergence, and sequence
exchanges between alleles or duplicated loci have been identified as likely
factors confounding the interpretation of the interrelationships among the three
species. In the present study most of these difficulties are overcome by
identifying evolutionary causes that might potentially provide misleading
information. Altogether, 45 loci consisting of 46, 855 bp are analyzed. About 60%
of the loci and approximately the same proportion of phylogenetically informative
sites support the human-chimpanzee clade. The remaining 40% of loci and sites
support the two alternatives equally. It is demonstrated that, while
incompatibility between loci can be explained by random sorting of allelic
lineages, incompatibility within loci must be attributed largely to the joint
effect of recombination and genetic drift. The trichotomy problem can be properly
addressed only within this framework.
PMID- 10679160
TI - Ancestral lineages of arbuscular mycorrhizal fungi (Glomales).
AB - Using new and existing 18S rRNA sequence data, we show that at least five species
of glomalean fungi lie outside the previously defined families and diverged very
early in the evolution of that group. These five fungi would have been missed by
many previous ecological studies because their sequences are not well matched to
available taxon-specific primers and they do not stain well with the standard
reagents used for morphological analysis. Based upon spore morphology, these
species are currently assigned to Glomus and Acaulospora, and two of the species
are dimorphic, exhibiting spore stages of both genera. This suggests that
dimorphic spores are the ancestral state for the order and that one or the other
morphology was lost in various lineages. Our analyses also show that Geosiphon
pyriforme, a symbiont with cyanobacteria, is not necessarily a sister group of
the Glomales; instead, it may be derived from mycorrhizal ancestors.
PMID- 10679161
TI - The complete external transcribed spacer of 18S-26S rDNA: amplification and
phylogenetic utility at low taxonomic levels in asteraceae and closely allied
families.
AB - For molecular phylogenetic reconstruction of some intrageneric groups of plants,
a DNA region is needed that evolves more rapidly than the internal transcribed
spacer (ITS) of the 18S-26S nuclear ribosomal DNA (nrDNA) repeat. If the region
identified is nuclear, it would also be desirable for it to undergo rapid
concerted evolution to eliminate problems with coalescence. The external
transcribed spacer (ETS) of the nrDNA repeat has shown promise for intrageneric
phylogenetic reconstruction, but only the 3' end of the region has been utilized
for phylogenetic reconstruction and "universal" primers for PCR amplification
have been elusive. We present a method for reliably amplifying and sequencing the
entire ETS throughout Asteraceae and some closely allied families. We also show
that the ETS is more variable and phylogenetically informative than the ITS in
three disparate genera of Asteraceae-Argyranthemum (tribe Anthemideae),
Asteriscus (tribe Inuleae), and Helianthus (tribe Heliantheae). The full ETS was
amplified using a primer (ETS1f) within the intergenic spacer in combination with
a primer (18S-2L) in the 5' end of the highly conserved 18S gene. ETS1f was
designed to correspond to a highly conserved region found in Helianthus and
Crepis, which are in separate subfamilies of Asteraceae. ETS1f/18S-2L primed in
all of the tribes of Asteraceae as well as exemplar taxa from Campanulaceae,
Goodeniaceae, and Calyceraceae. For both Argyranthemum and Asteriscus, we were
able to directly sequence the ETS PCR products when a single band was produced.
When multiple bands were produced, we gel-purified and occasionally cloned the
band of interest before sequencing. Although PCR produced single bands for
Helianthus species, it was necessary to clone Helianthus amplifications prior to
sequencing due to multiple intragenomic ETS repeat types. Alignment of ETS
sequences for Argyranthemum and Asteriscus was straightforward and unambiguous
despite some subrepeat structure in the 5' end. For Helianthus, different numbers
of large tandem subrepeats in different species required analysis of the
orthology of the subrepeats prior to alignment. In all three genera, the ETS
provided more informative variation for phylogenetic reconstruction and allowed
better resolution of relationships than the ITS. Although cloned sequences from
Helianthus differed, intragenomic clones consistently formed clades. This result
indicated that concerted evolution was proceeding rapidly enough in ETS that
species-specific phylogenetic signal was retained. It should be now be possible
to use the entire ETS for phylogenetic reconstruction of recently diverged
lineages in Asteraceae and at least three other families (approximately 26,000
species or about 8% of all angiosperms).
PMID- 10679162
TI - The evolutionary history of the genus Timarcha (Coleoptera, Chrysomelidae)
inferred from mitochondrial COII gene and partial 16S rDNA sequences.
AB - The apterous genus Timarcha consists of three subgenera and more than 100 species
in its Palearctic distribution, with specialized feeding on few plant families.
Fifty-four sequences sampled from 31 taxa of the genus plus three outgroup leaf
beetles were studied for their complete cytochrome oxidase II (COII) and a
fragment of 16S rDNA mitochondrial genes, representing a total of about 1200 bp.
Phylogenetic analyses using maximum-parsimony and distance methods for each gene
separately and for the combined data set gave compatible topologies. The subgenus
Metallotimarcha consistently appears in a basal position and is well
differentiated from the remaining Timarcha, but no clear monophyletic grouping of
Timarchostoma and Timarcha s. str. subgenera can be deduced from our analysis.
Calibration of the molecular clock has been done using the opening of the
Gibraltar Strait after the Messinian salinity crisis (about 5.5 MYA) as the
biogeographic event causing disjunction of two particular taxa. Accordingly, the
COII evolutionary rate has been estimated to be of 0.76 x 10(-8)
substitution/site/year in Timarcha. Relation between phylogeny and host-plant use
indicates widening of trophic regime as a derived character in Timarcha.
PMID- 10679163
TI - Characterization of novel sequences from distantly related taxa by walking PCR.
PMID- 10679182
TI - Regional differences in the CBF and BOLD responses to hypercapnia: a combined PET
and fMRI study.
AB - Previous fMRI studies of the cerebrovascular response to hypercapnia have shown
signal change in cerebral gray matter, but not in white matter. Therefore, the
objective of the present study was to compare (15)O PET and T *(2)-weighted MRI
during a hypercapnic challenge. The measurements were performed under similar
conditions of hypercapnia, which were induced by inhalation of 5 or 7% CO(2). The
baseline rCBF values were 65.1 ml hg(-1) min(-1) for temporal gray matter and
28.7 ml hg(-1) min(-1) for white matter. By linear regression, the increases in
rCBF during hypercapnia were 23.0 and 7. 2 ml hg(-1) min(-1) kPa(-1) for gray and
white matter. The signal changes were 6.9 and 1.9% for the FLASH sequence and
were 3.8 and 1. 7% for the EPI sequence at comparable echo times. The regional
differences in percentage signal change were significantly reduced when
normalized by regional flow values. A deconvolution analysis is introduced to
model the relation between fMRI signal and end-expiratory CO(2) level. Temporal
parameters, such as mean transit time, were derived from this analysis and
suggested a slower response in white matter than in gray matter regions. It was
concluded that the differences in the magnitude of the fMRI response can largely
be attributed to differences in flow and that there is a considerable difference
in the time course of the response between gray and white matter.
PMID- 10679183
TI - Electrophysiological correlates of recollecting faces of known and unknown
individuals.
AB - We recorded brain potentials from healthy human subjects during a recognition
test in order to monitor neural processing associated with face recollection.
Subjects first attempted to memorize 40 faces; half were accompanied by a voice
simulating that person speaking (e.g., "I'm Jimmy and I was a roadie for the
Grateful Dead") and half were presented in silence. In the test phase, subjects
attempted to discriminate both types of old faces (i.e., "named" and "unnamed"
faces) from new faces. Recognition averaged 87% correct for named faces, 74%
correct for unnamed faces, and 91% correct for new faces. Potentials to old faces
were more positive than those to new faces from 300 to 600 ms after face onset.
For named faces, the old-new ERP difference was observed at anterior and
posterior scalp locations. For unnamed faces, the old-new ERP difference was
observed only at posterior scalp locations. Results from a prior experiment
suggest that these effects do not reflect perceptual priming of faces. The
posterior portion of the old-new ERP difference was thus interpreted as a neural
correlate of retrieval of visual face information and the anterior portion as an
indication of retrieval of person-specific semantic information.
PMID- 10679184
TI - Cortical activity related to accuracy of letter recognition.
AB - Previous imaging and neurophysiological studies have suggested that the posterior
inferior temporal region participates in tasks requiring the recognition of
objects, including faces, words, and letters; however, the relationship between
accuracy of recognition and activity in that region has not been systematically
investigated. In this study, positron emission tomography was used to estimate
glucose metabolism in 60 normal adults performing a computer-generated letter
recognition task. Both a region of interest and a voxel-based method of analysis,
with subject state and trait variables statistically controlled, found task
accuracy to be: (1) negatively related to metabolism in the left ventrolateral
inferior temporal occipital cortex (Brodmann's area 37, or ventrolateral BA 37)
and (2) positively related to metabolism in a region of the right ventrolateral
frontal cortex (Brodmann's areas 47 and 11, or right BA 47/11). Left
ventrolateral BA 37 was significantly related both to hits and to false alarms,
whereas the right BA 47/11 finding was related only to false alarms. The results
were taken as supporting an automaticity mechanism for left ventrolateral BA 37,
whereby task accuracy was associated with automatic letter recognition and in
turn to reduced metabolism in this extrastriate area. The right BA 47/11 finding
was interpreted as reflecting a separate component of task accuracy, associated
with selectivity of attention broadly and with inhibition of erroneous responding
in particular. The findings are interpreted as supporting the need for control of
variance due to subject and task variables, not only in correlational but also in
subtraction designs.
PMID- 10679185
TI - The functional neuroanatomy and long-term reproducibility of brain activation
associated with a simple finger tapping task in older healthy volunteers: a
serial PET study.
AB - We examined long-term reproducibility of the functional organization of the brain
associated with a simple finger tapping movement using positron emission
tomography (PET). Repeat measurements of regional cerebral blood flow were
obtained in 10 individuals, ages 35 to 82 years (mean 52 years), at scanning
sessions separated by 6 months. Although the functional neuroanatomy of hand
movements has previously been investigated with PET by a number of groups, none
has reported systematic investigation of the consistency of brain activation over
an extended time. As expected, we found significant activation in the left
precentral gyrus [Talairach coordinate (-32, -34, 52)], postcentral gyrus (-22,
48, 56), and supplementary motor area (SMA) (-2, -18, 52) at the initial study,
consistent with previous studies in younger subjects. For the follow-up study we
also found significant activation in the left precentral (-36, -28, 52) and
postcentral (-28, -36, 52) gyri and in the SMA (2, -16, 56). Our group results
demonstrate consistent anatomical location and extent of motor activation over
time. More importantly, analysis of individuals confirmed the presence of
consistent sites of activation in primary sensorimotor cortex and SMA over the 6
month interval in most subjects. A high degree of consistency in location of
activation in the group, and within individuals, over time suggests that changes
in loci of activation may be confidently monitored using the PET method. Evidence
of individual differences in extent of activation over time highlights the need
for caution when interpreting similar changes in patient studies.
PMID- 10679186
TI - Distinguishing the functional roles of multiple regions in distributed neural
systems for visual working memory.
AB - We have investigated the human neural systems for visual working memory using
functional magnetic resonance imaging to distinguish sustained activity during
memory delays from transient responses related to perceptual and motor
operations. These studies have identified six distinct frontal regions that
demonstrate sustained activity during memory delays. These regions could be
distinguished from brain regions in extrastriate cortex that participate more in
perception and from brain regions in medial and lateral frontal cortex that
participate more in motor control. Moreover, the working memory regions could be
distinguished from each other based on the relative strength of their
participation in spatial and face working memory and on the relative strength of
sustained activity during memory delays versus transient activity related to
stimulus presentation. These results demonstrate that visual working memory
performance involves the concerted activity of multiple regions in a widely
distributed system. Distinctions between functions, such as perception versus
memory maintenance, or spatial versus face working memory, are a matter of the
degree of participation of different regions, not the discrete parcellation of
different functions to different modules.
PMID- 10679187
TI - A PET investigation of the attribution of intentions with a nonverbal task.
AB - Several authors have demonstrated that theory of mind is associated with a
cerebral pattern of activity involving the medial prefrontal cortex. This study
was designed to determine the cerebral regions activated during attribution of
intention to others, a task which requires theory-of-mind skills. Eight healthy
subjects performed three nonverbal tasks using comic strips while PET scanning
was performed. One condition required subjects to attribute intentions to the
characters of the comic strips. The other two conditions involved only physical
logic and knowledge about objects' properties: one condition involved characters,
whereas the other only represented objects. The comparison of the attribution of
intention condition with the physical logic with characters condition was
associated with rCBF increases in the right middle and medial prefrontal cortex
including Brodmann's area (BA) 9, the right inferior prefrontal cortex (BA 47),
the right inferior temporal gyrus (BA 20), the left superior temporal gyrus (BA
38), the left cerebellum, the bilateral anterior cingulate, and the middle
temporal gyri (BA 21). The comparison of the physical logic with characters
condition and the physical logic without characters condition showed the
activation of the lingual gyri (BA 17, 18, 19), the fusiform gyri (BA 37), the
middle (BA 21) and superior (BA 22, 38) temporal gyri on both sides, and the
posterior cingulate. These data suggest that attribution of intentions to others
is associated with a complex cerebral activity involving the right medial
prefrontal cortex when a nonverbal task is used. The laterality of this function
is discussed.
PMID- 10679188
TI - Regulation of beta-catenin signaling in the Wnt pathway.
AB - beta-Catenin not only regulates cell to cell adhesion as a protein interacting
with cadherin, but also functions as a component of the Wnt signaling pathway.
The Wnt signaling pathway is conserved in various organisms from worms to
mammals, and plays important roles in development, cellular proliferation, and
differentiation. Wnt stabilizes cytoplasmic beta-catenin and then beta-catenin is
translocated into the nucleus where it stimulates the expression of genes
including c-myc, c-jun, fra-1, and cyclin D1. The amounts and functions of beta
catenin are regulated in both the cytoplasm and nucleus. Its molecular mechanisms
are becoming increasingly well understood.
PMID- 10679189
TI - Evidence for the carboxyl methylation of nuclear lamin-B in the pancreatic beta
cell.
AB - Lamins are intermediate filament proteins that constitute the main components of
the lamina underlying the inner-nuclear membrane and serve to organize chromatin.
Lamins (e.g., lamin-B) undergo posttranslational modifications (e.g.,
isoprenylation and methylation) at their C-terminal cysteine. Such modifications
are thought to render optimal association of lamins with the nuclear envelop.
Herein, we examined whether nuclear lamin-B undergoes carboxyl methylation in
islet beta cells. A 65- to 70-kDa protein was carboxyl methylated in intact rat
islets and clonal beta (HIT or INS) cells or in homogenates which could be
immunoprecipitated using lamin-B antiserum. Incubation of purified HIT cell
nuclear fraction with [(3)H]S-adenosyl methionine yielded a single carboxyl
methylated protein peak (ca. 65-70 kDa); this protein was immunologically
identified as lamin-B. Several methylation inhibitors, including acetyl farnesyl
cysteine, a competitive inhibitor of protein prenyl cysteine methylation,
inhibited the carboxyl methylation of lamin-B, indicating that the carboxyl
methylated amino acid is cysteine. These findings, together with our recent
observations demonstrating that inhibition of protein isoprenylation causes
apoptotic death of the pancreatic beta cell, raise an interesting possibility
that inhibition of C-terminal cysteine modifications of lamin-B might result in
disruption of nuclear assembly, leading to further propagation of apoptotic
signals, including DNA fragmentation and chromatin condensation.
PMID- 10679190
TI - Evidence for translational repression of the SOCS-1 major open reading frame by
an upstream open reading frame.
AB - The suppressor of cytokine signalling 1 protein (SOCS-1) belongs to a novel
family of cytokine inducible factors which function as inhibitors of the JAK/STAT
pathway. While SOCS-1 previously has been described as a single-exon gene, here
we present evidence for an additional 5' exon, separated by a 509 bp intron from
exon 2. Exon 1 and part of exon 2 contain an open reading frame of 115 nt, ending
one nucleotide upstream of the major reading frame. Using SOCS-1
promoter/luciferase constructs, we investigated which sequences are involved in
the regulation of SOCS-1 expression. Serial promoter deletion clones indicate the
localization and functionality of SP1, interferon-stimulated responsive elements
(ISRE), and interferon-gamma-activated sites (GAS) promoter elements in the SOCS
1 5' flanking region. We present evidence that the upstream open reading frame
(uORF) represses the translation of the downstream major open reading frame
(mORF). Mutating the start codon of the uORF relieves this repression. Our data
indicate that expression of the SOCS-1 protein is repressed on translational
level by a mechanism, which bears similarities to that postulated for genes like
retinoic acid receptor beta2 (RARbeta2), S-adenosylmethionine-decarboxylase
(AdoMetDC), Bcl-2, and others.
PMID- 10679191
TI - Mode of molecular recognition of L-fucose by fucose-binding legume lectins.
AB - Recognition of cell surface carbohydrate moieties by lectins plays a vital role
in many a biological process. Fucosyated residues are often implicated as key
recognition markers in many cellular processes. In particular, the aspects of
molecular recognition of fucose by fucose-bindinglectins UEA 1 and LTA pose a
special case because no crystal structure of these lectins is available. The
study was conducted to elucidate the process of recognition of l-fucose by UEA1
and LTA by correlating structure-based sequence alignment and other available
biochemical/biophysical data. The study points out that the mode of recognition
of l-fucose is coordinated by the invariant triad of residues the asparagine 137,
glycine 105, and aspartate 87. The major hydrophobic stacking residue in this
case is the tyrosine 220. The study also reiterates the key role of the conserved
triad of residues in the combining site which is a common feature for all legume
lectins whose crystal structures are known.
PMID- 10679192
TI - Retinoic acid extends the in vitro life span of normal human oral keratinocytes
by decreasing p16(INK4A) expression and maintaining telomerase activity.
AB - Retinoic acid (RA) plays an important role in the regulation of cell growth and
differentiation. To investigate whether RA extends in vitro the life span of
human epithelial cells, we examined the effect of all-trans RA on both the
cumulative population-doubling level (PDL) and the replicative senescence of
cultured oral keratinocytes. When proliferating oral keratinocytes were cultured
in medium containing 1 nM of all-trans RA, the in vitro life span of the cells
was increased 1.5- to 1.8-fold compared to the vehicle control and the
replicative senescence of the cells was significantly inhibited. Since the
replicative senescence of human epithelial cells is associated with a steady
increase of p16(INK4A) and a loss of telomerase activity, we expected that RA
could delay the replicative senescence of oral keratinocytes by decreasing
p16(INK4A) expression and/or inhibiting the loss of telomerase activity. To test
this possibility, we examined the expression of replicative senescence-associated
genes and the telomerase activities of different PDL numbers of oral
keratinocytes exposed to 1 nM of all-trans RA. The protein level of cellular
p16(INK4A) in the RA-treated oral keratinocytes was gradually but significantly
enhanced by an increased PDL number; however, the level was significantly lower
than that of the vehicle control at all of the same PDL numbers. In contrast, the
telomerase activity was maintained in oral keratinocytes with increasing PDL
numbers induced by RA treatment. Summarizing, these results indicate that RA
induces the in vitro life-span extension of oral keratinocytes, which is linked
to a decreased cellular level of p16(INK4A) and the maintenance of telomerase
activity.
PMID- 10679193
TI - Vomeroglandin/CRP-Ductin is strongly expressed in the glands associated with the
mouse vomeronasal organ: identification and characterization of mouse
vomeroglandin.
AB - Vomeroglandin, a subform of mouse CRP-ductin, is a protein strongly expressed in
the glands of mouse vomeronasal system. Both the proteins contain several of
scavenger receptor cysteine-rich and CUB domains and one ZP domain. This domain
arrangement is similar to those of rat Ebnerin, human DMBT1, and rabbit hensin.
In situ hybridization analysis shows strong expression of vomeroglandin mRNA in
the glands of vomeronasal system. Immunological analyses detect both membrane
bound and secreted forms of vomeroglandin. The secreted protein seems to be
localized in the lumen of the vomeronasal organ, playing a certain role in the
pheromone perception.
PMID- 10679194
TI - Isolation and characterization of dcw cluster from Streptomyces collinus
producing kirromycin.
AB - A 4.5-kb BamHI fragment of chromosomal DNA of Streptomyces collinus containing
gene ftsZ was cloned and sequenced. Upstream of ftsZ are localized genes ftsQ,
murG, and ftsW, and downstream is yfiH. Gene ftsA is not adjacent to ftsZ or
other genes of the cloned fragment. Protein FtsZ was isolated and characterized
with respect to its binding to GTP and GTPase activity. The binding of GTP to
FtsZ was Ca(2+) or Mg(2+) dependent with an optimum at 10 mM. The rate of GTP
hydrolysis by FtsZ was stimulated by KCl. The presence of Ca(2+) (3-5 mM)
resulted in a significant increase of GTPase activity. Higher concentrations of
Ca(2+) than 5 mM had an inhibitory effect on GTPase activity. These results
indicate that divalent ions (Ca(2+) or Mg(2+)) can be involved in regulation of
GTP binding and hydrolysis of FtsZ. The maximum level of FtsZ was detected in
aerial mycelium when spiral loops and sporulation septa were formed. FtsZ is
degraded after finishing sporulation septa.
PMID- 10679195
TI - Vectors of shannon information from fourier signals characterizing base
periodicity in genes and genomes.
AB - Equal Symbol Fourier Transforms (FTES), characterizing nucleotide periodicity,
comprise components of 5-D vectors that define base-repeat properties of a
genomic sequence. This report describes a conversion of the FTES signals to a
common platform of Shannon information content to facilitate comparisons of
periodic data with other measures of information for genes and genomes. The
autocorrelation used to compute the discrete FTES formed the basis to define
repeating bases in terms of conditional probabilities. We derived a vector
equation to express the Shannon information content of a sequence in a way that
preserves the distinct specificity of base repeat patterns characterized by FTES
vectors. We suggest application of such information vectors to study the
structure of information in genes, chromosomes, and genomes by chi(2)
comparisons.
PMID- 10679196
TI - Purification, cloning, and three-dimensional structure prediction of Micrococcus
luteus FAD-containing tyramine oxidase.
AB - The FAD-containing tyramine oxidase enzyme and gene from the Gram (+) bacterium
Micrococcus luteus were isolated, and computer prediction was used to propose a
preliminary 3D model of the protein. A 2.8-kb Sau3AI fragment containing the
structural gene of tyramine oxidase was cloned from a M. luteus genomic DNA
library. The 1332 bp gene encodes a protein of 443 amino acids, with a calculated
molecular mass of 49.1 kDa. The enzyme was found to be a homodimer with a
molecular weight of 49,000. It oxidizes tyramine, adrenaline, 3-hydroxytyramine,
dopamine, and noradrenaline, and was reversibly inhibited by FAD-containing
monoamine oxidase A and B specific inhibitors. Sequence comparison show that
tyramine oxidase is smaller than other FAD-amine oxidases but that it contains
well-conserved amino acid residues reported in all other FAD-amine oxidases. A
hypothetical three-dimensional structure of tyramine oxidase has also been
proposed based on secondary structure predictions, threading, and comparative
modeling.
PMID- 10679197
TI - Cloning and characterization of a putative human d-2-hydroxyacid dehydrogenase in
chromosome 9q.
AB - There is little information on d-isomer-specific dehydrogenases in humans.
Identification of d-2-hydroxyglutaric aciduria, an inherited metabolic disorder
associated with severe neurological dysfunction, highlights the role of d-isomers
in human metabolism. The possibility of a defect in d-2-hydroxyglutarate
dehydrogenation prompted us to employ E. coli d-2-hydroxyacid dehydrogenase cDNA
to search the human expressed sequence tags database. Two human EST homologues
were retrieved and sequenced. Analysis showed the two clones were identical with
1258 nucleotides encoding 248 amino acids of the putative human d-2-hydroxyacid
dehydrogenase. It was highly homologous to bacterial d-2-hydroxyacid
dehydrogenases (46%), d-phosphoglycerate dehydrogenase (38%), and formate
dehydrogenase (36%) at the amino acid level. The gene is expressed ubiquitously
in tissue, most abundantly in liver, and was mapped to chromosome 9q between
markers WI-3028 and WI-93330. To our knowledge this is the first cloning and
characterization of the cDNA for a human d-isomer specific NAD(+)-dependent 2
hydroxyacid dehydrogenase.
PMID- 10679198
TI - Deficiency of current methods in assaying endochitinase activity.
AB - Since chitin is degraded by a combination of both endo- and exochitinases, it is
likely that both enzymes will be present in a crude extract. Currently used
substrates for detecting endochitinase activity suffer from the fact that they
could easily be digested by the contaminating exochitinase, thus giving either a
false-positive or an inaccurate reading of the endochitinase activity. Using
Photorhabdus luminescens, a bacterium symbiotically associated with insect
parasitic nematode Heterorhabditis bacteriophora as an exemplary system, we have
identified these two chitinases by a simple "fluorimetric zymography" procedure.
The exochitinase is a metalloenzyme and its activity is inhibited by 1,10
phenanthroline. Once the exochitinase activity is detected in a crude extract,
its contribution must be eliminated before accurate determination of the
endochitinase activity can be carried out. Specific properties of these enzymes
including the pH activity profile, the requirement of metal ions for activity,
and the molecular weight of the enzymes are among the factors to be considered in
developing assaying procedures for endochitinase.
PMID- 10679199
TI - Molecular characterization reveals identity of microtubule-associated proteins
MAP3 and MAP4.
AB - The identity of two microtubule-associated proteins, MAP3 and MAP4, was verified
both immunologically and biochemically. MAP3 was enriched from the heat-stable
fraction of rat brain extracts by reverse-phase HPLC and preparative two
dimensional gel electrophoresis. Both MAP3 and MAP4 antibodies reacted with the
corresponding spots on two-dimensional Western blots. Amino acid sequences of
internal peptides derived from rat MAP3 matched with corresponding sequence
stretches of mouse MAP4. In the kidney cortex, the MAP3 antibody stained not only
glomerular podocytes but also interstitial cells. This distribution pattern of
MAP3 is identical to that of MAP4 reported previously. These results indicate
that MAP3 and MAP4 are identical.
PMID- 10679200
TI - Inhibition of protein tyrosine phosphatases by low-molecular-weight S
nitrosothiols and S-nitrosylated human serum albumin.
AB - The homogeneous recombinant mammalian protein tyrosine phosphatase 1B (PTP1B) and
Yersinia protein tyrosine phosphatase (PTPase) are inactivated by a series of low
molecular-weight S-nitrosothiols. These compounds exhibited different inhibitory
activities in a time- and concentration-dependent manner with second-order rate
constants (k(inact)/K(I)) ranging from 37 to 113 M(-1) min(-1) against mammalian
PTP1B and from 66 to 613 M(-1) min(-1) against Yersinia PTPase. Furthermore, the
inactivation of Yersinia PTPase by S-nitrosylated protein:S-nitroso human serum
albumin was investigated. Both single-S-nitrosylated and poly-S-nitrosylated
human serum albumin show good inhibitory ability to Yersinia PTPase. The second
order rate constants are 472 and 1188 M(-1) min(-1), respectively. This result
indicates a possibility that S-nitrosylated albumin in vivo may function as an
inhibitor for a variety of cysteine-dependent enzymes.
PMID- 10679202
TI - Cloning and characterization of a novel adaptor protein, CIN85, that interacts
with c-Cbl.
AB - The c-Cbl protooncogene product is a prominent substrate of protein tyrosine
kinases and is rapidly tyrosine-phosphorylated upon stimulation of a wide variety
of cell-surface receptors. We have identified a novel c-Cbl-interacting protein
termed CIN85 with a molecular mass of 85 kDa which shows similarity to adaptor
proteins, CMS and CD2AP. CIN85 mRNA is expressed ubiquitously in normal human
tissues and cancer cell lines analyzed. CIN85 was basally associated with c-Cbl.
For interaction of CIN85 with c-Cbl, the second SH3 domain of CIN85 was shown to
serve as a central player. The CIN85-c-Cbl association was enhanced shortly after
stimulation of 293 cells with epidermal growth factor (EGF) and gradually
diminished to a basal level, which correlated with a tyrosine phosphorylation
level of c-Cbl. Our results suggest that CIN85 may play a specific role in the
EGF receptor-mediated signaling cascade via its interaction with c-Cbl.
PMID- 10679201
TI - PKB inhibition prevents the stimulatory effect of insulin on glucose transport
and protein translocation but not the antilipolytic effect in rat adipocytes.
AB - We identified 1-(5 chloronaphthalenesulfonyl)-1H-hexahydro-1, 4-diazepine, also
known as ML-9, as a powerful inhibitor of PKB activity in different cells as well
as of recombinant PKB. It also inhibits other downstream serine/threonine
kinases, such as PKA and p90 S6 kinase, but not upstream tyrosine phosphorylation
or PI3-kinase activation in response to insulin. We compared the effects of ML-9
and wortmannin on several insulin-stimulated effects in isolated rat fat cells.
Both ML-9 and wortmannin inhibited glucose transport and GLUT4/IGF II receptor
translocation to the plasma membrane. In contrast, only wortmannin inhibited the
antilipolytic effect and PDE3B activation by insulin. Thus, ML-9 inhibits PKB but
not PI3-kinase activation in response to insulin and is useful to differentiate
between these effects. Both PI3-kinase and PKB are important for glucose
transport and intracellular protein translocation while PKB does not appear to
play an important role for the antilipolytic effect or activation of PDE3B in
response to insulin.
PMID- 10679203
TI - Effect of hypoxia on nitric oxide production and its synthase gene expression in
rat smooth muscle cells.
AB - It has not been clarified yet as to whether hypoxia and inflammation affect NO
synthesis. In this study, we investigated the transcription of inducible nitric
oxide synthase (iNOS) mRNA and the production of nitric oxide (NO) in rat smooth
muscle cells (SMCs) cultured under hypoxic conditions in the presence and absence
of proinflammatory cytokine interferon-gamma (IFN-gamma) and lipopolysaccharide
(LPS). We found that hypoxia inhibited the production of NO but did not affect
the transcription of iNOS mRNA in rat SMCs treated with IFN-gamma, LPS, or both.
These results indicate that O(2) is involved in the regulation of NO synthesis in
inflammatory tissues.
PMID- 10679204
TI - Antimicrobial peptide of korean native goat lactoferrin and identification of the
part essential for this activity.
AB - The antimicrobial activity of lactoferrin isolated from Korean native goat (KN
goat) milk was studied and its antimicrobial domain was identified using
synthetic peptides. Antimicrobial activity was assayed by a micro-method using 96
well microplates and a microplate reader. The amino acid sequence of the
antimicrobial domain was suggested to be YQWQRRMRKLGAPSIT and this sequence
corresponds to amino acid residues 20 to 35 of KN goat lactoferrin. Five peptides
with certain amino acid residues deleted were synthesized in an effort to
identify the residues essential for antimicrobial activity and it was found that
the part with the sequence RRMRK (24-28) is the region most important for this
activity. On the other hand, the conformation of the peptides did not influence
the antimicrobial activity.
PMID- 10679205
TI - Constitutive and inducible expression of hepatic CYP2E1 in leptin-deficient ob/ob
mice.
AB - In this study we have analyzed the inducible as well as constitutive hepatic
expression of Cyp2e1 in a genetic model of obesity and non-insulin dependent
(type II) diabetes, the leptin-deficient ob/ob mouse. In obese mice, Cyp2e1
levels were decreased compared to lean littermates. Treatment with leptin
increased hepatic Cyp2e1 in obese mice to the levels observed in lean animals,
but failed to alter Cyp2e1 expression in lean animals. As expected, leptin also
reduced food intake in treated mice compared to saline-treated controls. In obese
mice pair-fed the reduced amount of food, there was a significant increase in
Cyp2e1 mRNA but no increase in Cyp2e1 protein or enzyme activity. Fasting and
administration of acetone and 4-methylpyrazole increased Cyp2e1 mRNA as well as
protein and activity in both obese and lean mice. The present data indicate that
while Cyp2e1 is still inducible in obese mice by xenobiotics and fasting, full
constitutive expression of Cyp2e1 requires leptin to be present. This effect of
leptin appears to be at least partly independent of the hypothalamic control of
food intake.
PMID- 10679206
TI - Cloning and characterization of the cytochrome P450 oxidoreductase gene from the
zygomycete fungus Cunninghamella.
AB - The filamentous fungus Cunninghamella utilizes cytochrome P450 system(s) in the
metabolism of a broad range of polyaromatic and aliphatic pollutants and a
variety of drugs, but prior attempts at isolation of P450 system components of
this fungus have been generally unsuccessful. We report upon the cytochrome P450
oxidoreductase (CPR) gene from two widely studied species, C. elegans and C.
echinulata. The C. elegans CPR gene was obtained by screening a genomic library
using as probe a PCR amplicon obtained with degenerate primers based on known
CPRs. The 2420 bp coding region contained two apparent introns (149 bp and 138
bp). Northern blot analysis showed that the CPR gene is transcriptionally
expressed in C. elegans and appears to be inducible by an alkane substrate, n
tetradecane. Phylogenetic comparison of the deduced C. elegans CPR (710 aa)
suggested that it is more closely related to animal CPRs (41-42%) than to yeast
(38-41%) and plant (35-36%) forms. A 2074 bp sequence containing most of the CPR
gene homolog from C. echinulata was also isolated.
PMID- 10679207
TI - Alternative splicing of gar-1, a Caenorhabditis elegans G-protein-linked
acetylcholine receptor gene.
AB - We have recently identified a gene, designated gar-1, coding for a novel form of
G-protein-linked acetylcholine (ACh) receptor in Caenorhabditis elegans. Although
this receptor is most closely related to muscarinic ACh receptors (mAChRs),
electrophysiological analyses have shown that ligand binding specificity of the
receptor is distinct from that of mAChRs. Here we report that three receptor
isoforms are generated by alternative splicing of the gar-1 transcript. These
receptor isoforms differ only in the third intracellular loop that is considered
to be important for G protein coupling. The three splice variants, when expressed
in Xenopus oocyte, displayed similar pharmacological profiles and signaling
activities. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis
showed that the three gar-1 mRNAs are present at all developmental stages
examined. The results in this study provide evidence that alternative splicing is
involved in promoting molecular diversity of G-protein-linked ACh receptors.
PMID- 10679208
TI - Restoration of mRNA splicing by a second-site intragenic suppressor in the T4
ribonucleotide reductase (small subunit) self-splicing intron.
AB - The nrdB gene of bacteriophage T4 codes for the small subunit of ribonucleotide
reductase and contains a 598-base self-splicing intron which is closely related
to other group I introns of T4 and eukaryotes. Thirty-one mutants causing
splicing defects in the nrdB intron were isolated. Twenty-three EMS-induced
revertants for these 31 primary mutants were isolated by the strategic usage of
the white halo plaque phenotype. We mapped these revertants by marker rescue
using subclones of the nrdB gene. Some of these second-site mutations mapped to
regions currently predicted by the secondary structure model of the nrdB intron.
One of these suppressor mutants (nrdB753R) was found to be intragenic by marker
rescue with the whole nrdB gene. However, this mutation failed to map within the
nrdB intron. Splicing assays showed that this pseudorevertant restored splicing
proficiency of the nrdB primary mutation to almost wild-type conditions. This is
the first example of a mutation within the exons of a gene containing a self
splicing intron that is capable of restoring a self-splicing defect caused by a
primary mutation within the intron. In addition, two other suppressor mutations
are of interest (nrdB429R and nrdB399R). These suppressors were able to restore
their primary 5' defect but in turn create a 3' splicing defect. Both of these
revertants mapped in different regions of the intron with respect to their
primary mutations.
PMID- 10679209
TI - The metal dependence of Bacillus subtilis phytase.
AB - The metal ion requirement of a Bacillus subtilis phytase has been studied.
Removal of metal ions from the enzyme by EDTA resulted in complete inactivation.
Circular dichroism spectroscopy was used to study the effect of metal ion removal
on the protein conformation. The loss of enzymatic activity is most likely due to
a conformational change, as the circular dichroism spectra of holoenzyme and
metal-depleted enzyme were different. Metal-depleted enzyme was partially able to
restore the active conformation when incubated in the presence of calcium. Only
minor reactivation was detected with other divalent metal ions and their
combinations. Based on the data we conclude that B. subtilis phytase requires
calcium for active conformation. Calcium has also a strong stabilizing effect on
the enzyme against thermal denaturation. However, the conformational change
resulted by calcium depletion does not affect the protease susceptibility.
PMID- 10679210
TI - X-Linked juvenile retinoschisis associated with a 4-base pair insertion at codon
55 of the XLRS1 gene.
AB - X-linked juvenile retinoschisis (RS) is a bilateral vitreoretinal disorder with
no known cure. The gene responsible for the disease was recently isolated by
positional cloning methods and a spectrum of mutations has been described in
families with RS pathology. In this report, we screened six sporadic cases of RS
for mutations in the RS gene to understand the etiology of isolated cases. Our
extensive studies revealed a novel 4 bp insertion in one family and the remaining
families did not show mutations in the RS gene. This mutation altered the reading
frame including codon 55 resulting in nine aberrant amino acid residues. The
unaffected mother did not contain this mutation. Additionally, it was not found
in 60 normal control chromosomes, suggesting that the insertion mutation is
disease related in the family analyzed.
PMID- 10679211
TI - Expression of the Aspergillus fumigatus phytase gene in Pichia pastoris and
characterization of the recombinant enzyme.
AB - Aspergillus fumigatus phytase is a heat-stable enzyme of great potential. Our
objective was to determine if a high level of functional expression of the A.
fumigatus phytase gene could be produced in Pichia pastoris and how the
recombinant phytase reacted to different substrates, heating conditions, and
proteases. A 1.4-kb DNA fragment containing the coding region of the gene was
inserted into the expression vector pPICZalphaA and expressed in P. pastoris as
an active, extracellular phytase (r-Afp). The yield was 729 mg of purified
protein per liter of culture, with a specific activity of 43 units/mg of protein.
The enzyme r-Afp shared similar pH and temperature optima, molecular size,
glycosylation extent, and specificity for p-nitrophenyl phosphate and sodium
phytate to those of the same enzyme expressed in A. niger. Given 20 min of
exposure to 65 to 90 degrees C, the enzyme retained 20 to 39% higher residual
activity in 10 and 200 mM sodium acetate than that in sodium citrate. The enzyme
seemed to be resistant to pepsin digestion, but was degraded by high levels of
trypsin. In conclusion, P. pastoris is a potential host to express high levels of
A. fumigatus phytase and the thermostability of the recombinant enzyme is
modulated by the specificity of buffer used in the heat treatment.
PMID- 10679212
TI - Characterization of a new phenoloxidase inhibitor from the cuticle of Manduca
sexta.
AB - Melanin, the phenolic biopolymer that serves as a skin- and hair pigment
protecting agent against harmful solar radiation and a free radical trap, is
biosynthesized in animals mainly by the action of tyrosinase also known as
phenoloxidase. Regulation of tyrosinase and hence melanogenesis is vital for all
animals. In this report, we present the isolation and characterization of a new,
heat-labile glycoprotein inhibitor of phenoloxidase from the larvae of Manduca
sexta. The inhibitor was isolated from the live larval cuticle by buffer
extraction and purified to homogeneity employing ammonium sulfate precipitation,
dialysis, and concanavalin A-Sepharose chromatography. It migrated with a
molecular weight of 380,000 on SDS-PAGE gels and inhibited the activity of insect
and plant as well as fungal phenoloxidases. Inhibitor formed a tight complex with
phenoloxidases, which resisted dissociation even by 1% Triton X-100 or SDS.
Selective inhibition of phenoloxidase, while acting on certain but not all
different substrates, was observed. The physiological importance of this newly
discovered high-molecular-weight phenoloxidase inhibitor is discussed.
PMID- 10679213
TI - Computational design of new cyclic urea inhibitors for improved binding of HIV-1
aspartic protease.
AB - We report in this paper the design, by means of computational techniques, of new
cyclic urea inhibitors of the HIV aspartic protease. The relationship between the
complexation energies of the enzyme with known inhibitors and the experimentally
determined log K(i) have been studied and used to predict inhibition constants
for new inhibitors.
PMID- 10679214
TI - Light chain of natural antibody plays a dominant role in protein antigen binding.
AB - Examinations of the contribution and the specificity of heavy (H) and light (L)
chains of natural antibodies to antigen binding may help us to better understand
antigen recognition and the development of naive B cells. We previously generated
natural Fab antibody fragments reactive to preS1 of HBV using a naive, non
immunized Fab antibody library derived from peripheral B cells of a normal
healthy volunteer. We now constructed expression vectors for the Fd (VH + CH1), L
chain, and scFv fragments using the sequences encoding parental Fabs as a source
of natural antibody genes. The recombinant antibody fragments were expressed as
inclusion bodies in E. coli BL21 (DE) cells. When denatured and then refolded,
the antibody fragments retained their binding properties. Recombinant L chains
and scFvs exhibited three- to 40-fold higher affinities (in the order of 10(7) M(
1)) over the parental Fabs, whereas the affinities of Fds (in the order of 10(5)
M(-1)) were much lower compared to the parental Fabs. The results obtained from
sandwich ELISA revealed that the L chains bound the virus more efficiently than
Fds. Additional experiments were performed to evaluate the specificity of the
recombinant fragments for surface proteins of HBV. Fds and L chains were reactive
towards HBsAg and the preS2 peptide as well as preS1 and showed patterns of
epitope recognition quite different from those of parental Fabs. The data
presented here demonstrate that the prominence of the L chain in determining
protein binding activity is a property of natural antibodies and is quite unlike
the antibodies induced by immunization, and that the specificity of Fab is not
determined by the individual antibody chain but by the correct pairing of H and L
chain.
PMID- 10679215
TI - Interactions of cytochrome c peroxidase with lysine peptides.
AB - Structural change of Cytochrome c peroxidase (CcP) due to interaction with lysine
peptides (Lysptds) has been studied by absorption spectra and measurements on
electron transfer between cytochrome c (cyt c) and CcP in the presence of Lysptd.
Peaks were observed in the difference absorption spectrum of CcP between in the
presence and absence of Lysptds, demonstrating a structural perturbation of CcP,
at least at its heme site, on interaction with Lysptd. The interaction between
CcP and Lysptd was electrostatic, since no significant peak was detected in the
difference absorption spectrum when 100 mM of NaCl was added to the solution.
Lysptds competitively inhibited electron transfer from cyt c to CcP, which
indicated that they interacted with CcP at the same site as cyt c and would be
models of the CcP interacting site of cyt c.
PMID- 10679216
TI - High affinity ScFvs from a single rabbit immunized with multiple haptens.
AB - We report the generation of single-chain Fv (scFv) fragments with high affinities
against four different hapten molecules from a single immunised rabbit. The
rabbit was immunised with a mixture of protein conjugates of four different
haptens, namely the herbicide mecoprop and derivatives of the herbicides
atrazine, simazine, and isoproturon. An scFv phage display library was
constructed, and several scFvs with high affinity against each hapten were
isolated. For each hapten, a single binder was selected by k(off) ranking and
used for affinity determination. The affinities were in sub-nanomolar range and
the lowest K(d) value obtained was 6.75 x 10(-10) M. An unusual feature of one of
the anti-isoproturon scFvs was its ability to retain binding activity at pH1.7.
The utility and potential of using a single animal and immunisation with multiple
antigens for the production of multiple, specific, high affinity scFvs by phage
display is discussed.
PMID- 10679217
TI - A novel function of serum amyloid A: a potent stimulus for the release of tumor
necrosis factor-alpha, interleukin-1beta, and interleukin-8 by human blood
neutrophil.
AB - High density lipoprotein (HDL) and its main apolipoproteins, AI and serum amyloid
A (SAA), present in physiological and acute phase response conditions,
respectively, affect the inflammatory process. This study focuses on the effect
of AI, SAA, and HDL from healthy (N-HDL) and acute phase individuals (AP-HDL) on
the release of TNF-alpha, IL-1beta, and IL-8 by human blood neutrophils. It was
observed that SAA (100 microg/mL) causes a dramatic increase (75-400 times) in
the basal liberation of the three cytokines assayed. This effect is not triggered
by AP-HDL. Although AI (100 microg/ml) increases the release of IL-1beta and IL-8
modestly, N-HDL does not. Both HDLs (0.16-0.32 mg of protein/mL) had an anti
inflammatory action, decreasing the basal and LPS-stimulated cytokine release.
Given that the biological role of SAA is still uncertain, the present study adds
an important finding potentially pertinent to the biological role of this acute
phase protein.
PMID- 10679218
TI - Physiological evidence for an interaction between helix XI and helices I, II, and
V in the melibiose carrier of Escherichia coli.
AB - In a previous study 23 residues in helix XI of the cysteine-less melibiose
carrier were changed individually to cysteine. Several of these cysteine mutants
(K377C, A383C, F385C, L391C, G395C) had low transport activity and they were
white on melibiose MacConkey fermentation plates. After several days of
incubation of these white clones on melibiose MacConkey plates a rare red mutant
appeared. The plasmid DNA was then isolated and sequenced. The two second site
revertants from K377C were I22S and D59A. This change of aspartic acid to a
neutral residue suggests that physiologically there is an interaction between
K377 and D59 (possibly a salt bridge). The revertants from A383C were in
positions 20 (F20L) and 22 (I22S and I22N). Revertants of F385C were intrahelical
changes (I387M and A388G) and a change in C-terminal loop (R441C). Revertants of
L391C were in helix I (I22N, I22T and D19E) and helix V (A152S). Revertants of
G395C were in helix I (D19E and I22N). We suggest that there is an interaction
between helix XI and helices I, II, and V and proximity between these helices.
PMID- 10679219
TI - Differential stimulation of prostaglandin G/H synthase-2 in osteocytes and other
osteogenic cells by pulsating fluid flow.
AB - Mechanical stress produces flow of fluid in the osteocytic lacunar-canalicular
network, which is likely the physiological signal for the adaptive response of
bone. We compared the induction of prostaglandin G/H synthase-2 (PGHS-2) by
pulsating fluid flow (PFF) and serum in osteocytes, osteoblasts, and periosteal
fibroblasts, isolated from 18-day-old fetal chicken calvariae. A serum-deprived
mixed population of primarily osteocytes and osteoblasts responded to serum with
a two- to threefold induction of PGHS-2 mRNA. Serum stimulated PGHS-2-derived
PGE(2) release from osteoblasts and osteocytes but not from periosteal
fibroblasts as NS-398, a PGHS-2 blocker, inhibited PGE(2) release from osteocytes
and osteoblasts with 65%, but not that from periosteal fibroblasts. On the other
hand PFF (0.7 Pa, 5 Hz) stimulated (3 fold) PGHS-2 mRNA only in OCY. The related
PGE(2) response could be completely inhibited by NS-398. We conclude that
osteocytes have a higher intrinsic sensitivity for loading-derived fluid flow
than osteoblasts or periosteal fibroblasts.
PMID- 10679220
TI - Characterization of Erwinia chrysanthemi PY35 cel and pel gene existing in tandem
and rapid identification of their gene products.
AB - Genomic DNA of the phytopathogenic Erwinia chrysanthemi PY35 was partially
digested with Sau3AI, ligated into the BamHI site of pBluescript II SK+, and
introduced into E. coli. One clone that was able to hydrolyse
carboxymethylcellulose and polygalacturonic acid was selected. A 2.9 kb fragment
containing the pelL1 gene (pPY300) and cel5Z gene (pPY401) in tandem was
subcloned and sequenced. The pelL1 and cel5Z genes had open reading frames of
1,278 bp and 1,281 bp encoding 425 and 426 amino acid residues with calculated
molecular weights of 45,649 Da and 46,473 Da, respectively. pelL1 and cel5Z
carried a typical prokaryotic signal peptide of 24 and 41 amino acid residues,
respectively. The apparent molecular masses of the proteins when expressed in E.
coli cells were approximately 43 kDa (PelL1) and 42 kDa (Cel5Z) as assessed by
PGA-SDS-PAGE and CMC-SDS-PAGE.
PMID- 10679221
TI - Correlation between the chaperone-like activity and aggregate size of alpha
crystallin with increasing temperature.
AB - alpha-Crystallin, the major protein of the mammalian eye lens, is also found in
the major tissues of the body, where one or the other of its two isoforms is
characteristically expressed. Both isoform sequences are highly related to others
of the small heat shock protein superfamily, leading to speculation about their
functions in vivo outside of the lens. Tests of chaperone-like activity at 37 and
66 degrees C indicate that the protein can act to prevent the superaggregation of
partially denatured proteins, but both alpha-crystallin aggregate size and shape
are significantly altered with increasing temperature. Characterization of these
changes indicates that secondary, tertiary, and quaternary structure are
modified, with the latter effect especially striking above 50 degrees C.
Furthermore, these changes appear to be irreversible when the temperature is
returned to 25 or 37 degrees C. Functionally, the protein is effective in
chaperone-like activity at all temperatures, but exhibits a somewhat increased
capability after a cycle of heating and cooling. The results presented here
indicate the heat-induced formation of high-molecular-weight aggregates of alpha
crystallin is a slow progressive process. The increased activity of these
aggregates suggests that chaperone-like activity depends in part on the packing
parameters of the aggregate and on conformation of the subunit within that
aggregate.
PMID- 10679222
TI - Kassinatuerin-1: a peptide with broad-spectrum antimicrobial activity isolated
from the skin of the hyperoliid frog, Kassina senegalensis.
AB - Kassinatuerin-1 (GFMKYIGPLI(10)PHAVKAISDL(20)I.NH(2)) was isolated in high yield
(75 nmol/g) from an extract of the skin of a Hyperoliid frog, the African running
frog Kassina senegalensis and its sequence was confirmed by total synthesis. The
peptide inhibited growth of the gram-negative bacterium Escherichia coli (minimum
inhibitory concentration, MIC = 4 microM), the gram-positive bacterium
Staphylococcus aureus (MIC = 8 microM), and the yeast Candida albicans (MIC = 70
microM). A structurally related peptide, kassinatuerin-2
(FIQYLAPLI(10)PHAVKAISDL(20)I.NH(2)) was also isolated in high yield (96 nmol/g)
from the extract but was devoid of antimicrobial activity against these
microrganisms. Kassinatuerin-1 may be classified with other linear, cationic
antimicrobial peptides that can potentially adopt an amphipathic alpha-helical
conformation but it contains almost no amino acid sequence identity with
previously characterized bioactive peptides from frog skin.
PMID- 10679223
TI - Human 3'-phosphoadenosine 5'-phosphosulfate synthetase 1 (PAPSS1) and PAPSS2:
gene cloning, characterization and chromosomal localization.
AB - Sulfae conjugation is an important pathway in the metabolism of a large number of
exogenous and endogenous compounds. These reactions are catalyzed by
sulfotransferase (SULT) enzymes that utilize 3'-phosphoadenosine 5'
phosphosulfate (PAPS) as a sulfate donor. PAPS is synthesized from ATP and
inorganic sulfate by PAPS synthetase (PAPSS). Two separate PAPSS cDNAs, PAPSS1
and PAPSS2, have been identified in human tissues. We have cloned and
characterized the genes for human PAPSS1 and PAPSS2 to make it possible to study
the pharmacogenomics of these enzymes. Both genes consisted of 12 exons with
virtually identical exon-intron splice junction locations. All splice junctions
conformed to the "GT-AG" rule. The total length of PAPSS1 was approximately 108
kb, while that of PAPSS2 was greater than 37 kb. The 5'-flanking region of PAPSS1
did not include a TATA box sequence near the site of transcription initiation,
but PAPSS2 had a TATA motif located 21 bp upstream from the site of transcription
initiation. Northern blot analysis showed that the major PAPSS1 and PAPSS2
transcripts were approximately 2.7 and 4.2 kb in length, respectively. PAPSS1
mapped to human chromosome band 4q24 while PAPSS2 mapped to 10q22-23 by
fluorescence in situ hybridization analysis. Cloning and structural
characterization of PAPSS1 and PAPSS2 will make it possible to perform molecular
genetic and pharmacogenomic studies of these important enzymes in humans.
PMID- 10679224
TI - Number of glomeruli is increased in the kidney of transgenic mice expressing the
truncated type II activin receptor.
AB - Histological analyses of the kidney were performed in transgenic mice expressing
the truncated type II activin receptor. In these mice, signaling through the
activin receptor was attenuated. Size and wet weight of the kidneys were
identical to those of normal mice. Histologically, the number of glomeruli was
approximately 180% of that in normal mice. The sizes and shapes of the glomeruli
were variable, but many of them were smaller than those in normal mice.
Morphometrically, the total glomerular area was 130% of that of the normal mice.
Abnormality of the epithelia in Bowman's capsule was observed and the number of
tubular epithelial cells was increased in the transgenic mice. The serum levels
of blood urea nitrogen, creatinine, and creatinine clearance were identical to
those in normal mice. These results suggest that the action of activin or related
ligands is critical for determination of the nephron number.
PMID- 10679225
TI - Multipotency of a bone marrow stromal cell line, TBR31-2, established from ts
SV40 T antigen gene transgenic mice.
AB - Bone marrow is believed to contain multipotential stromal stem cells which can
differentiate into osteoblasts, chondrocytes, adipocytes, and myoblasts (Prockop,
D. J. Science 276, 71-74, 1997). Therefore, characterization and identification
of the stem-like cell within the stromal cells are important to understand bone
marrow function in relation to the hematopoietic microenvironment, and
repair/regeneration of tissue defects. TBR31-2 cell, a bone marrow stromal cell
line established from bone marrow of transgenic mice harboring temperature
sensitive (ts) simian virus (SV) 40T-antigen gene for immortality, is induced
toward both adipocytic and osteogenic cells under conditions of the inactivation
of T-antigen (Okuyama, R., Yanai, N., Obinata, M. Exp. Cell Res. 218, 424-429,
1995). In this work, using a semiquantitative reverse transcriptase-polymerase
chain reaction (RT-PCR) analysis, mRNA expressions of tissue-specific
differentiation markers for adipocyte (lipoprotein lipase), osteoblast (type I
collagen and osteocalcin), chondrocyte (type II and X collagen), and muscle cell
(desmin) were examined during a long-term culture of the cell. In addition,
histochemical studies showed the appearance of adipocytic, osteoblastic,
chondrocytic, and muscle cells during this long-term culture. Thus, TBR31-2,
which has characteristics of an undifferentiated cell, has the potential to
express the multipotential cell lineages. These results indicated that a
multipotential progenitor cell including potential to differentiate into a muscle
cell and which is situated in the mesenchymal cell lineage was first obtained.
PMID- 10679226
TI - Human hepatitis B virus X protein is a possible mediator of hypoxia-induced
angiogenesis in hepatocarcinogenesis.
AB - The hepatitis B virus (HBV)-encoded transcriptional activator HBV-X protein (HBx)
was known to be involved in hepatocarcinogenesis. Hepatocarcinogenesis generally
included an active angiogenesis that was mainly considered to be due to a local
hypoxia in liver tissues. However, the exact mechanisms of HBx-induced
hepatocarcinogenesis were poorly understood. In this study, we examined the role
of HBx in the increased angiogenesis and the possible regulating mechanisms of
HBx by hypoxia. We demonstrated that HBx stimulated the transcription of vascular
endothelial growth factor (VEGF), a potent angiogenic factor, in HBx-stable
transfectants. HBx-induced angiogenesis was confirmed by in vivo tumor
angiogenesis assay, resulting in that the HBx transfectants increased the
formation of new blood vessels compared to the control transfectants. Then, we
demonstrated that the expression of HBx was enhanced after incubating HBV
infected hepatoma cells under hypoxia. Moreover, the activity of HBV enhancer 1
(Enh1) was increased when hepatoma cells transfected with the reporter plasmid
containing HBV Enh1 were exposed to hypoxic conditions. These results strongly
suggest that HBx may play a critical role in the hypoxia-induced angiogenesis
through transcriptional activation of VEGF during hepatocarcinogenesis.
PMID- 10679227
TI - Engineered metal binding sites on green fluorescence protein.
AB - The ability to assay a variety of metals by noninvasive methods has applications
in both biomedical and environmental research. Green fluorescent protein (GFP) is
a protein isolated from coelenterates that exhibits spontaneous fluorescence. GFP
does not require any exogenous cofactors for fluorescence, and can be easily
appended to other proteins at the DNA level, producing a fluorescence-labeled
target protein in vivo. Metals in close proximity to chromophores are known to
quench fluorescence in a distance-dependent fashion. Potential metal binding
sites on the surface of GFP have been identified and mutant proteins have been
designed, created, and characterized. These metal-binding mutants of GFP exhibit
fluorescence quenching at lower transition metal ion concentrations than those of
the wild-type protein. These GFP mutants represent a new class of protein-based
metal sensors.
PMID- 10679228
TI - Characterization of a novel gene encoding a phytocyanin-related protein in
morning glory (Pharbitis nil).
AB - A cDNA for a novel phytocyanin homolog was cloned from apical buds of morning
glory (Pharbitis nil). The predicted protein was most similar to a family of
early nodulins, which are expressed during the formation of symbiotic root
nodules of legume plants, and less similar to typical phytocyanins such as
lacquer tree stellacyanin and cucumber basic protein. The amino acid sequence
predicted that it is a secreted protein associated with other components of the
extracellular matrix. Hybridization analyses showed that the transcript was
expressed specifically in meristems and procambia of apical buds and root tips.
The transcript level in the apical buds decreased significantly on flower
inducing treatment. Involvement of this phytocyanin-related protein in plant
organ differentiation is discussed.
PMID- 10679229
TI - Enhancement of the migration of metastatic human breast cancer cells by
phosphatidic acid.
AB - Phosphatidic acid (PA), lysophosphatidic acid (LPA), and sphingosine 1-phosphate
(SPP) are naturally occurring phospholipids which induce a variety of effects as
extracellular messengers. In this study, we compared the effects of these
phospholipid signaling molecules on the migration of invasive and noninvasive
breast cancer cell lines, an index of the metastatic potential of these cells. As
previously demonstrated, invasive MDA-MB-231 breast cancer cells exhibited
increased constitutive (nonstimulated) migration in comparison to poorly invasive
MCF-7 cells. Phosphatidic acid employed at nanomolar concentrations markedly
potentiated migration of the invasive cells but had no effect on migration of
either the noninvasive MCF-7 cells or nonneoplastic human epithelial cells.
Lysophosphatidic acid and sphingosine 1-phosphate inhibited both the directed
(chemotactic) and random (chemokinetic) migration of MDA-MB-231 cells.
Experiments were undertaken to characterize the signaling pathway involved in
constitutive and PA-stimulated migration of MDA-MB-231 cells. The tyrosine kinase
inhibitors staurosporine and genistein inhibited constitutive and PA-induced
migration in a dose-dependent manner, consistent with a role for tyrosine
phosphorylation in the migratory response. In addition, the phosphatidylinositol
(PI) 3' kinase inhibitors wortmannin and LY294002 strongly inhibited both the
constitutive and PA-stimulated migration of the invasive breast cancer cells,
indicating that PI-3' kinase plays an important role in the metastatic migration
of breast cancer cells. Finally, PA-induced migration of MDA-MB-231 was markedly
attenuated by pretreatment of cells with Clostridium difficile Toxin B, pertussis
toxin and suramin, implying a role for a Gi receptor-dependent process involving
activation of the small GTP-binding protein Rho. Since an enhanced ability to
migrate heightens the metastatic potential of cells within solid tumors, our
results suggest that the metastatic capabilities of breast cancer cells may be
enhanced by a receptor-driven cellular process initiated by phosphatidic acid or
related lipid phosphate messengers.
PMID- 10679230
TI - Nicotine binding to native and substituted peptides comprising residues 188-207
of nicotinic acetylcholine receptor alpha1, alpha2, alpha3, alpha4, alpha5, and
alpha7 subunits.
AB - Structural determinants of L-[(3)H]nicotine binding to synthetic peptides
comprising residues 188-207 of nicotinic acetylcholine receptor alpha subunits
were invesitigated by equilibrium binding analysis. Two binding components were
detected, one of low affinity (K(d) approximately 1.5 microM) that did not differ
significantly among peptides and another of high affinity. The high affinity
binding component was higher for the neuronal peptides (K(d) = 14-23 nM) than the
muscle alpha1 peptides (K(d) = 52 nM). The following nonconservative
substitutions in the alpha4 peptide resulted in a significant decrease in
nicotine affinity for the peptide: Y190A, Y190D, C192G, E195A, E195-, P199A, P199
, and Y203A. Substitution of alpha4P199 with a leucine which is present in the
alpha1 sequence decreased the affinity of the alpha4 peptide for nicotine and
substitution of alpha1L199 with a proline (alpha4) or a glutamine (alpha3)
increased the affinity of the alpha1 peptide. It is concluded that aromatic
residues contribute to the binding site for nicotine on the alpha4 subunit and
that the residue present at position 199 partly determines differences in
nicotine affinity for different alpha subunits.
PMID- 10679231
TI - Pancreatic acinar cells submitted to stress activate TNF-alpha gene expression.
AB - To elucidate whether pancreatic acinar cell submitted to stress is able to
express TNF-alpha, we studied TNF-alpha mRNA expression by Northern blot and in
situ hybridization in healthy pancreas, in tissue from caerulein-induced
pancreatitis and after lipopolysaccharide (LPS) treatment. In specimens from
normal pancreas, TNF-alpha mRNA expression, as judged by both Northern blot and
in situ hybridization, was negative, whereas a strong but transient expression
was observed in acinar cells from caerulein pancreatitis and LPS treatment. TNF
alpha mRNA appeared as rapidly as 30 min after treatment, and was maximal 6 h
after. At this time, there was mild infiltration consisting mostly of
polymorphonuclear leukocytes (PMNL) and no signal of TNF-alpha transcript was
found in their cytoplasm. Our results strongly indicate that pancreatic acinar
cell is the source of TNF-alpha early in the course of acute pancreatitis and LPS
treatment, and suggest that the expression of this cytokine is a part of a
general response of the acinar cell to aggression.
PMID- 10679232
TI - The role of glucose and its metabolism in the regulation of glucokinase
expression in isolated human pancreatic islets.
AB - Previous reports concerning the regulation of glucokinase expression in beta
cells have been done using cell models from rodent origin. Evidence is lacking so
far to implicate the same regulatory mechanisms in human cells. In this study, we
investigate the effects of glucose on the expression of glucokinase using
isolated human pancreatic islets. High glucose (16.7 mM), in a time-dependent
manner, increases the amount of immunoreactive glucokinase (+150% after 7 days
culture, P < 0.01) without apparent changes in glucokinase gene expression,
suggesting that glucose exerts its effect at a posttranscriptional level.
Mannose, but not the nonmetabolized hexoses, 3-O-methylglucose or 2-deoxyglucose,
increases glucokinase protein content. Even though these findings are compatible
with an involvement of signals derived from glucose metabolism, additional data
argue against this hypothesis: (i) a glucokinase inhibitor (mannoheptulose) does
not block glucose-induced increase in glucokinase content and (ii) other
metabolic fuels (amino acids) are ineffective. We suggest that the glucose
molecule, by mechanisms yet to be defined, but probably not involving its
metabolism, regulates human glucokinase expression.
PMID- 10679233
TI - Peridinin as the major biological carotenoid quencher of singlet oxygen in marine
algae Gonyaulax polyedra.
AB - Carotenoids in light-harvesting proteins and reaction centers increase the
overall efficiency of photosynthesis by transferring absorbed light energy to
chlorophylls. Peridinin and beta-carotene were isolated from Gonyaulax polyedra
in a one-step purification protocol using the preparative circular chromatography
(Chromatotron), performed on silica gel under N(2) atmosphere and n
hexane/acetone 8:2 as mobile phase and characterized by extensive (1)H NMR,
infrared, and electrospray ionization mass spectrometry analyses. The quenching
of singlet molecular oxygen [O(2) ((1)Delta(g))] was evaluated by NIR-emission
assays using singlet oxygen generated by sensitization of either perinaphthenone
or methylene blue. The NIR-emission assay showed that peridinin quench as singlet
oxygen (k(q) = 9.5 x 10(8) M(-1) s(-1)) 5-fold less efficiently than beta
carotene (52 x 10(8) M(-1) s(-1)). A method, based on the use of high-performance
liquid chromatography with UV-VIS detection, was then developed for the sensitive
quantification of peridinin (55% of total carotenoids) and beta-carotene (4.1% of
total carotenoids). Thus, since peridinin is 10-fold more abundant than beta
carotene, it is expected to be the major protector against the deleterious
effects of O(2) ((1)Delta(g)) in Gonyaulax polyedra.
PMID- 10679234
TI - Histone H1 variants play individual roles in transcription regulation in the DT40
chicken B cell line.
AB - Thirty-nine of the 44 chicken histone genes are located in a major gene cluster
of 110 kb, the others being distributed in four separate regions. All 6 H1 genes,
which are present in the cluster and encode different variants, are expressed in
the DT40 chicken B cell line, at levels ranging from about 5 to 40%. To clarify
differences in the natures of these H1 variants, using gene-targeting techniques,
we generated a series of DT40 mutants, which are devoid of each of the 5 H1
genes, respectively. Analyses of six H1-deficient mutants, comprising the latter
five and a previously generated H1-deficient mutant, revealed that the protein
patterns on 2D-PAGE were definitely different from each other, indicating that
each H1 variant plays an individual role in the transcription regulation of
specific genes in DT40 cells.
PMID- 10679235
TI - Identification of a nuclear ribonucleoprotein particle which contains
incompletely spliced HIV-1 RNAs.
AB - Unspliced and partially spliced HIV RNAs are transported to the cytoplasm by the
HIV encoded Rev protein. In the present study, a ribonucleoprotein complex which
contains such incompletely spliced HIV RNA is identified. Soluble nuclear
extracts were prepared from the lymphocyte cell line H9/IIIB that constitutively
produces HIV-1 from a stably integrated provirus. Sucrose gradient centrifugation
of the extracts and subsequent analysis of the gradient fractions by a
ribonuclease protection assay revealed a population of incompletely spliced HIV-1
RNAs which accumulates in the 100S region of the gradient. Similar analysis of
cellular mRNAs including beta-actin and glyceraldehyde 3-phosphate dehydrogenase
(GAPDH) revealed that these RNA molecules also exhibit characteristic
sedimentation profiles in sucrose gradients. This study suggests that nuclear
ribonucleoprotein particles containing incompletely spliced HIV-1 RNAs are
amenable for biochemical characterisation.
PMID- 10679236
TI - Activation of caspase-3 in molt4 cells by apoptosis-inducing nucleosides from
CD57(+)HLA-DR(bright) natural suppressor cell line.
AB - Apoptosis-inducing nucleosides (AINs), which were released and isolated from
CD57(+)HLA-DR(bright) natural suppressor (57.DR-NS) cell line derived from human
decidual tissue, induced apoptosis in Molt4 cells. The addition of caspase-3
inhibitor into the reaction blocked the cleavage of caspase-3 and apoptosis in
Molt4 cells treated with AINs, detected by flow cytometrical or
spectrofluorometrical analysis and DNA fragmentation assay. Furthermore, by means
of immunoblotting, the processing of caspase-3 was shown with the appearance of
their catalytically active subunits of 20 and 11 kDa during the generation of
apoptosis in Molt4 cells treated with AINs. This processing of caspase-3 into
active subunits was also blocked by the addition of caspase-3 inhibitor. Thus, it
was definitely revealed that the activation of caspase-3 was a key feature in the
caspase cascade of AINs-induced apoptosis in Molt4 cells.
PMID- 10679237
TI - Duality monomer-dimer of the pheromone-binding protein from Bombyx mori.
AB - The analysis of a recombinant pheromone-binding protein from the silkworm moth,
Bombyx mori, by native gel electrophoresis with Coomassie staining showed one
single band with a molecular mass consistent with a monomer. A slow migrating
band, detected in the recombinant and native samples by a polyclonal antibody,
was indistinguishable from the monomer in the mass spectrum fragmentation pattern
and chromatographic behavior. Flow injection analyses of the protein by mass
spectrometry in the negative mode showed fragments of a dimer. The dimeric form
was also supported by estimation of the molecular mass by gel filtration at basic
pH. A cross-linked dimer coeluted with the noncovalent dimer on a gel filtration
column. The molecular mass of the protein changed in a pH-dependent way with a
dramatic transition from dimer to monomer between pH 6 and 4.5. A low pH induced
not only dissociation of the dimer, but also a conformational change in the
protein. In marked contrast to denaturation with guanidinium chloride, the
emission maxima of tryptophan was not significantly changed at low pH. BmPBP is
thus a dimer at slightly acid, neutral, and basic pH, which dissociates and then
undergoes conformational change at low pH.
PMID- 10679238
TI - Human p55(CDC)/Cdc20 associates with cyclin A and is phosphorylated by the cyclin
A-Cdk2 complex.
AB - The initiation of anaphase and exit from mitosis depend on the activation of the
anaphase-promoting complex/cyclosome (APC/C), a multicomponent, ubiquitin-protein
ligase. The WD-repeat protein called p55(CDC)(Cdc20) directly binds to and
activates APC/C. By using yeast two-hybrid screening, we found that cyclin A, a
critical cell cycle regulator in the S and G2/M phases, specifically interacts
with p55(CDC). Ectopically expressed p55(CDC) and cyclin A form a stable protein
complex in mammalian cells. The p55(CDC)-cyclin A interaction occurs through the
region containing the WD repeats of p55(CDC) and the region between the
destruction box and the cyclin box of cyclin A. In addition to the physical
interaction, p55(CDC) is phosphorylated by cyclin A-associated kinase. These
findings suggest that the function of p55(CDC) is mediated or regulated by its
complex formation with cyclin A.
PMID- 10679239
TI - Genome-wide detection of unknown subtle mutations in bacteria by combination of
MutS and RDA.
AB - We propose a procedure for detecting unknown, subtle DNA changes throughout the
entire bacterial genome by a combination of MutS and RDA. Current techniques
detect subtle mutations after PCR amplification of the target regions, so the
mutation detection is done between amplified PCR fragments. In this paper, genome
wide subtle mutation scanning in bacteria was performed by combining the MutS and
RDA techniques. Our strategy for cloning a small mutation region is composed of
two steps: an enrichment of fragments containing subtle mutations using MutS,
followed by an RDA subtraction procedure for further enrichment. We successfully
identified small mutations such as a four-base insertion, a two-base insertion,
and transition mutations in bacteria.
PMID- 10679240
TI - Signaling through the p38 and p42/44 mitogen-activated families of protein
kinases in pancreatic beta-cell proliferation.
AB - The present study has focused on the role of the 42- and 44-kDa mitogen-activated
protein kinases (p42/44 MAPKs) and the 38-kDa mitogen-activated protein kinase
(p38 MAPK) in the proliferation of the pancreatic beta-cell line MIN6. MIN6 beta
cell proliferation was assessed by measuring 5-bromo-2'-deoxyuridine (BrdU)
incorporation into cellular DNA. Inhibition of both the p42/44 MAPK pathway using
the MEK inhibitor PD098059 (PD) and the p38 MAPK pathway using the p38 inhibitor
SB203580 (SB) caused a marked, concentration-dependent reduction in the BrdU
immunostaining observed in the presence of 15% FCS when assessed using
fluorescence immunocytochemistry. These data provide direct evidence of a role
for p42/44 MAPKs in the mitogenic response of MIN6 beta-cells to FCS.
Furthermore, these data also suggest a novel role for the p38 MAPK pathway in
MIN6 beta-cell proliferation.
PMID- 10679241
TI - E-Selectin expression in a murine model of chronic colitis.
AB - The objective of this study was to quantify E-selectin surface expression in the
colon as well as other tissues in a CD4(+) T-cell model of chronic colitis in
mice using the newly developed dual radiolabel monoclonal antibody technique.
Male SCID mice were reconstituted with either 5 x 10(5) CD4(+) CD45RB(low) or
CD45RB(high) T-cells isolated from normal CB-17 donor mouse spleens and
subsequently monitored for clinical signs of colitis. We found that animals
injected with CD45RB(high) but not CD45RB(low) T-cells nor PBS developed colitis
at 6-8 weeks following reconstitution as assessed by loss of body weight,
development of loose stools and/or diarrhea, and histopathology. Concurrent with
the onset of distal bowel inflammation was enhanced expression of E-selectin
compared to SCID mice injected with PBS or reconstituted with CD45RB(low) T
cells, both of which did not develop colitis. We also observed significant
increases in E-selectin expression in cecum, small intestine, mesentery, and
liver of colitic mice. Our data confirm that reconstitution of SCID mice with
CD45RB(high) but not CD45RB(low) T-cells induces chronic colitis and demonstrate
that this chronic colitis is associated with enhanced expression of an
endothelial cell-specific adhesion molecule. Furthermore, our studies demonstrate
that reconstitution of SCID mice with CD45RB(high) T-cells enhances E-selectin
expression in a variety of tissues distant from the site of active inflammation.
PMID- 10679242
TI - Growth suppression of Escherichia coli by induction of expression of mammalian
genes with transmembrane or ATPase domains.
AB - Growth inhibition of Escherichia coli host cells is frequently observed when some
mammalian genes are induced to express exogenously. To find common features of
these mammalian genes, an assay was designed for the isolation of these genes
which show growth-inhibitory effect on E. coli by induction of expression. Of
38,000 clones derived from a mouse brain cDNA library, 64 cDNA clones were
systematically selected out by this method, of which 45 clones had putative open
reading frames encoding proteins with putative membrane-associated regions or ATP
binding/ATPase activities. These results show that a fraction of membrane
associated proteins or ATP-binding/ATPase genes can be isolated from cDNA
libraries by our simple method.
PMID- 10679243
TI - Identification of casein kinase I substrates by in vitro expression cloning
screening.
AB - Casein kinase I (CKI) is a widely expressed protein kinase family implicated in
diverse processes including membrane trafficking, DNA repair, and circadian
rhythm. Despite the large number of CKI genes, few biologically relevant
substrates have been identified. As an approach to better defining the spectrum
of CKI substrates, we extended a recently described in vitro expression cloning
(IVEC) strategy. Polypeptides pools were screened for kinase-dependent
electrophoretic mobility shifts. Ten putative CKI substrates were isolated from
an initial sample of 3000 random cDNA clones. Candidate substrates include
proteins involved in RNA metabolism (a putative RNA helicase, the nucleolar
protein hNOP56, and hnRNP A1, and ribosomal proteins L4, L8, and L13), as well as
keratin 17, a necdin-related protein, and the calcium-binding proteins desmoglein
2 and annexin II. The same pools were also screened with active ERK2, and four
substrates identified: aldolase, NSD-like protein, uracil-DNA glycosylase, and
HHR23A. IVEC is an effective method to identify novel protein kinase substrates.
PMID- 10679244
TI - Effect of somatostatin and octreotide on proliferation and vascular endothelial
growth factor secretion from murine endothelial cell line (HECa10) culture.
AB - Angiogenesis, development of new blood vessels, is required for normal tissue
repair and also for tumor cell proliferation, extracellular matrix invasion, and
hematogenous metastases. Vascular endothelial growth factor (VEGF) is an
endothelial cell-specific mitogen that has been shown to play a key role in
neovascularization. Inhibition of angiogenesis in vitro and in vivo was
documented by administration of native neuropeptide somatostatin and its analog
octreotide. We have studied the effect of somatostatin-14 (SRIF) and ocreotide
(sandostatin) on proliferation activity and VEGF release from cultured murine
endothelial cells HECa10 in vitro. SRIF in concentrations from 10(-9) to 10(-5) M
and ocreotide in concentrations from 10(-9) to 10(-5) M diminished the
proliferative activity of cultured cells vs controls. SRIF and ocreotide in
concentrations from 10(-14) to 10(-6) M did not change the release of VEGF into
supernatants of 24 or 72 h endothelial cell cultures. Although we showed the
antiproliferative effect of SRIF and ocreotide on mouse endothelial cells, we
were unable to demonstrate the inhibitory effect of tested peptides on VEGF
secretion in vitro.
PMID- 10679245
TI - Rapid agonist-induced phosphorylation of the human CRF receptor, type 1: a
potential mechanism for homologous desensitization.
AB - Agonist-induced phosphorylation of the human corticotropin-releasing factor type
1 receptor (hCRF(1)-R) was investigated using an influenza hemagglutinin (HA)
epitope-tagged receptor transiently expressed in COS-7 cells. The HA-hCRF(1)-R
migrated as a broad band (M(r) 60,000-70,000) in SDS-PAGE and showed increased
mobility (M(r) approximately 48,000) after enzymatic deglycosylation with peptide
N-glycosidase F, consistent with the predicted size (47 kDa) of the
nonglycosylated HA-hCRF(1)-R protein. A marked increase in HA-hCRF(1)-R
phosphorylation was observed in HA-hCRF(1)-R-expressing COS-7 cells exposed to 1
microM ovine CRF for 5 min, whereas activation of protein kinase A (PKA) by 50
microM forskolin, or of Ca(2+)/calmodulin (CaM)-dependent kinases by 10 microM
ionomycin, had little effect. These findings are consistent with preliminary data
suggesting that CRF(1)-R phosphorylation mediated by G protein receptor kinase 3
(GRK3), but not by PKA or CaM-dependent kinases, has an important role in the
homologous desensitization of brain CRF(1)-Rs.
PMID- 10679246
TI - Characterization of a postreceptor signaling defect that impairs cfos expression
in cultured fibroblasts of a patient with insulin resistance.
AB - Induction of cfos expression is a definite end point of signal transduction by
receptor tyrosine kinases via MAPK cascades. We have examined signal transduction
to transcription factor cFos in isolated fibroblasts of a patient with an
inherited syndrome of insulin resistance. MAPK phosphorylation and activity were
unaltered, but inducibility of cfos transcription was strongly impaired by
insulin and reduced by PDGF. Induction of the cfos promoter via MAPK is mediated
by activation of the ternary complex. Abundance of SRF or Elk-1 was unaltered,
but Elk-1 phosphorylation following stimulation was reduced. Transient
transfections with reporter genes under control of the Elk-1 binding ets/sre cis
element or expression plasmids coding for the regulatory domain of Elk-1 fused to
heterologous DNA binding domains revealed a defect of Elk-1 activation in the
patient cells. These data identify a novel postreceptor defect of insulin and
growth factors involving activation of transcription.
PMID- 10679247
TI - Edg-6 as a putative sphingosine 1-phosphate receptor coupling to Ca(2+) signaling
pathway.
AB - The endothelial differentiation gene-6 (Edg-6) was recently identified as an
orphan G-protein-coupled receptor. Its predicted amino acid sequence is very
close to Edg family of receptor proteins whose ligand is supposed to be
lysophosphatidic acid (LPA) or lysosphingolipid such as sphingosine 1-phosphate
(S1P) and sphingosylphosphorylcholine (SPC). Transfection of the Edg-6 into
Chinese hamster ovary (CHO) cells and K562 cells resulted in the appearance of
high-affinity [(3)H]S1P binding activity. Among lipids employed, S1P and, even
though less potent, SPC, displaced the [(3)H]S1P binding, but LPA was inactive.
In Edg-6-transfected CHO cells, an increase in cytosolic Ca(2+) concentration in
response to S1P or SPC was clearly enhanced without change in the LPA-induced
action as compared with the vector-transfected cells. The enhancement of the
Ca(2+) response was associated with a significant accumulation of inositol
phosphate, reflecting activation of phospholipase C. Similar enhancement of
Ca(2+) response to S1P or SPC was also observed in Edg-6-expressing K562 cells.
These lipid-induced actions in CHO cells and K562 cells expressing Edg-6 were
markedly suppressed by pertussis toxin treatment. We conclude that Edg-6 is one
of S1P or lysosphingolipid receptors that couple to phospholipase C-Ca(2+) system
through pertussis toxin-sensitive G-proteins.
PMID- 10679248
TI - The oocyte-specific methylated region of the U2afbp-rs/U2af1-rs1 gene is
dispensable for its imprinted methylation.
AB - Imprinted genes harbor discrete regions which are differentially methylated in
gametes; usually the final differential methylation patterns in adults are
established during embryogenesis through modifications of the initial methylation
patterns in gametes. Previous reports have shown that a 200-bp region termed
region II within the CpG island of the mouse imprinted U2afbp-rs gene is
methylated in oocytes but not in sperm, suggesting that this region is a center
for the propagation of methylated CpGs on the maternal allele and is also a
candidate for an imprinting control element. To determine whether region II is
required for the imprinted methylation of this gene at the endogenous locus, we
generated mice carrying a deletion of this region. We herein show that parental
methylation differences still exist in the CpG island on the region II-deleted
allele. These findings suggest that region II is dispensable for the imprinted
methylation of the U2afbp-rs gene.
PMID- 10679249
TI - Identification of three alternative first exons and an intronic promoter of human
PDE5A gene.
AB - In the accompanying paper we present evidence for the existence of three PDE5A
isoforms that differed only in the 5' end of the mRNAs. In this paper we present
evidence that the three isoform-specific 5' ends were encoded by three
alternative first exons that were arranged in the order of A1-A3-A2. Because the
isoform-specific mRNAs could be transcribed from individual promoters, DNA
fragments of the two intronic regions (A1-A3 and A3-A2) were tested for possible
promoter activities. The intron between A1- and A3-specific exons did not exhibit
any promoter activities even in smooth muscle cells that expressed the A3 isoform
(see accompanying paper). In contrast, the intron between A3- and A2-specific
exons had promoter activities in PDE5A2-expressing COS-7 and smooth muscle cells.
This intronic promoter was bound by transcription factors AP-2 and Sp1, but not
by AP-1, as shown by DNase I footprint analysis. However, the sequence bound by
AP-2 (5'-GGGAAACGCTCGCGGGAGAGTTGG) is unusual in that it bears little resemblance
to the consensus AP-2-binding sequence.
PMID- 10679250
TI - Sphingomyelin potentiates chemotherapy of human cancer xenografts.
AB - We propose that one manifestation of altered sphingolipid metabolism within tumor
cells may be a reduced sensitivity to anti-cancer therapies because of an
inability to produce a sufficient apoptotic signal via sphingomyelin hydrolysis
to ceramide. If so, then sphingomyelin administration could reverse this effect
and increase a tumor's sensitivity to chemotherapy. In vivo, intravenous
sphingomyelin (10 mg/day, 7 days) potentiated 5-fluorouracil chemotherapy (0.45
mg/day, 5 days) when co-administered to HT29 human colonic xenograft-bearing nude
mice. In vitro, sphingomyelin (SM) at its maximum tolerated concentration
increased 5-fluorouracil and doxorubicin sensitivity of HCT15 and MOSER (1 mg/ml
SM) and LS174T and SW480 human colonic tumor cells (0.1 mg/ml) approximately 100
300%. At 1 mg/ml SM, however, no effect was seen using HT29, LoVo and WiDr cells.
There was no sensitization of normal human umbilical cord endothelial cells.
Thus, sphingomyelin co-administration may be one method to improve the selective
efficacy of chemotherapy in some tumors, possibly through enhancement of the
apoptotic response.
PMID- 10679251
TI - Transforming growth factors beta(1) (TGF-beta(1)) and TGF-beta(2) promote glioma
cell migration via Up-regulation of alpha(V)beta(3) integrin expression.
AB - The migratory behaviour of malignant gliomas relies on the interaction of
integrins with extracellular matrix (ECM) components. Transforming growth factor
beta(1) (TGF-beta(1)) potently stimulates glioma cell motility whereas TGF
beta(2) is known for its immunosuppressive properties. Here, we show that both
TGF-beta(1) and TGF-beta(2) promote migration of glioma cells. In parallel, TGF
beta(1) and TGF-beta(2) induce alpha(V) and beta(3) intergrin mRNA expression and
enhance cell surface expression of alpha(V)beta(3) integrin. TGF-beta-mediated
promotion of migration is abrogated by echistatin, a Arg-Gly-Asp (RGD) peptide
antagonist of alpha(V)beta(3) integrin, and by a neutralizing anti
alpha(V)beta(3) integrin antibody. Taken together, we report a novel mechanism by
which TGF-beta modulates cell ECM interactions and promotes glioma cell motility.
PMID- 10679252
TI - Missense variations of the gene responsible for Wolfram syndrome (WFS1/wolframin)
in Japanese: possible contribution of the Arg456His mutation to type 1 diabetes
as a nonautoimmune genetic basis.
AB - Recently, a novel gene for a putative transmembrane protein (WFS1/wolframin) was
found to be mutated in patients with Wolfram syndrome or DI-DM-OA-D (diabetes
insipidus, diabetes mellitus, optic atrophy, and deafness) syndrome. It is
suggested that the WFS1 protein is important in the survival of islet beta-cells.
We studied the WFS1 gene in a Japanese population to assess its possible role in
common type 1 diabetes. Mutation screening revealed four missense mutations;
R456H, G576S, H611R, and I720V. By genetic association studies of 185 type 1
diabetes patients and 380 control subjects, we found that R456H was significantly
increased in the type 1 diabetes group compared to the control group (P =
0.0005); H611R and I720V were also significantly increased with weaker
significance. Furthermore, in patients with the R456H mutation, type 1 diabetes
resistant HLA-DRB1 alleles (DRB1*0406, 1501, and 1502) were significantly
increased compared to mutation-negative patients while susceptible DRB1*0901 was
significantly decreased. Frequencies of autoimmunity characteristics (ICA or GAD
Ab positiveness and combination of autoimmune thyroid disease) were decreased in
the R456H-positive patients compared to the R456H-negative patients. These data
suggest that the WFS1 gene may have a role in the development of common type 1
diabetes as a nonautoimmune genetic basis.
PMID- 10679253
TI - Cloning and characterization of mRNA capping enzyme and mRNA (Guanine-7-)
methyltransferase cDNAs from Xenopus laevis.
AB - The mRNA cap structure, which is synthesized by a series of reactions catalyzed
by capping enzyme, mRNA (guanine-7-)-methyltransferase, and mRNA (ribose-2'-O-)
methyltransferase, has crucial roles for RNA processing and translation.
Methylation of the cap structure is also implicated in polyadenylation-mediated
translational activation during Xenopus oocyte maturation. Here we isolated two
Xenopus laevis cDNAs, xCAP1a and xCAP1b, for mRNA capping enzyme and one cDNA for
mRNA (guanine-7-)-methyltransferase, xCMT1, which encode 598, 511, and 402 amino
acids, respectively. The deduced amino acid sequence of xCAP1a was highly
homologous to that of human capping enzyme hCAP1a, having all the characteristic
regions including N-terminal RNA 5'-triphosphatase as well as C-terminal mRNA
guanylyltransferase domains which are conserved among animal mRNA
guanylyltransferases, whereas in xCAP1b the most C-terminal motif was missing.
The amino acid sequence of xCMT1 was also similar to human (guanine-7-)
methyltransferase, hCMT1a, with all the conserved motifs among cellular (guanine
7-)-methyltransferases, except for its N-terminal portion. The recombinant xCAP1a
and xCMT1 exhibited cap formation and mRNA (guanine-7-)-methyltransferase
activities, respectively. RT-PCR analysis showed that mRNA for xCAP1a and xCMT1
exist abundantly in fertilized eggs as maternal mRNAs, but xCMT1 mRNA gradually
decreased in its amount in later stages of early development.
PMID- 10679254
TI - ATP synthesis in rod outer segments of bovine retina by the reversal of the disk
Ca(2+) pump.
AB - Purified disk membranes from rod outer segments of the bovine retina were able to
synthesize ATP with a maximal activity (about 52 nmoles ATP/min/mg of protein) at
physiological calcium concentrations. This activity was inhibited by vanadate or
thapsigargin but not by oligomycin, suggesting the reversal functioning of the
disk Ca(2+)-ATPase, which would act as a ATP synthesizer at the expense of the
calcium gradient between the disks and the cytoplasm of the rod outer segment.
The results are discussed in terms of the need of an immediate source of ATP on
the disk membranes where the energy is required to supply the rapid reactions of
the photoreception processes.
PMID- 10679255
TI - Expression of three isoforms of cGMP-binding cGMP-specific phosphodiesterase
(PDE5) in human penile cavernosum.
AB - Inhibition of cGMP-specific phosphodiesterase type V (PDE5) has been shown to
improve penile erection in patients with erectile dysfunction. We report here the
cloning of three PDE5 isoforms from human penile tissues. Two of the isoforms
were identical to PDE5A1 and PDE5A2, respectively, which had been isolated from
nonpenile tissues. The third isoform was novel and hence called PDE5A3. The
deduced amino acid sequence of PDE5A3 was the same as the C-terminal 823-residue
sequence of PDE5A1 and PDE5A2. While PDE5A1 and A2 isoforms were expressed in all
tissues examined, the A3 isoform was confined to tissues with a smooth muscle or
cardiac muscle component. When expressed in COS-7 cells, PDE5A1, A2, and A3
isoforms had similar cGMP-catalytic activities with K(m) of 6.2, 5.75, and 6.06
microM, respectively. Their cGMP-catalytic activities were inhibited by zaprinast
with IC(50) values of 3.2 microM, 1.3 microM, and 1.6 microM, respectively, and
by sildenafil with IC(50) of 28, 14, and 13 nM, respectively.
PMID- 10679256
TI - C2-Ceramide increases cytoplasmic calcium concentrations in human parathyroid
cells.
AB - Effects of extracellular calcium ([Ca(2+)](ext)) on parathyroid cells are mainly
due to the activation of a plasma membrane calcium receptor (CaR) coupled with
release of intracellular calcium. In addition, high [Ca(2+)](ext) activates the
sphingomyelin pathway in bovine parathyroid cells, generating ceramides and
sphingosine. This study explored the direct effects of synthetic ceramides on
[Ca(2+)](i) in human parathyroid cells. Cells from five parathyroid adenomas
removed from patients with primary hyperparathyroidism were dispersed and
maintained in primary culture. Intracellular calcium concentration ([Ca(2+)](i))
[Ca(2+)](i) was monitored using standard quantitative fluorescence microscopy in
Fura-2/AM-loaded cells. Laser scanning microscopy was used to monitor the
intracellular distribution of a fluorescent ceramide analogue (BODIPY-C5). After
addition of 10 microM C2-ceramide (N-acetyl-d-erythro-sphingosine), [Ca(2+)](i)
increased rapidly (30-60 s) to a peak three times above basal levels in 70% of
cells (37/55 cells in four experiments). This effect appeared to be due to
release of Ca(2+) from intracellular stores rather than Ca(2+) entry from the
extracellular medium. C2-responsive cells had a smaller [Ca(2+)](i) response to
subsequent stimulation with the CaR agonist-neomycin (1 mM). These responses were
specific to C2 since C6-ceramide (N-hexanoyl-d-erythro-sphingosine) did not
affect basal [Ca(2+)](i) nor the responses to an increase in [Ca(2+)](ext) and to
neomycin. C5-BODIPY generated intense perinuclear fluorescence, suggesting
targeting of the ceramides to the Golgi apparatus. These data demonstrate that
endogenous generation of ceramides has the potential to modulate changes in
[Ca(2+)](i) and secretion in response to [Ca(2+)](ext) in human parathyroid
cells.
PMID- 10679257
TI - Oxidative stress induces increase in intracellular amyloid beta-protein
production and selective activation of betaI and betaII PKCs in NT2 cells.
AB - Amyloid beta-protein (Abeta) aggregation produces an oxidative stress in neuronal
cells that, in turn, may induce an amyloidogenic shift of neuronal metabolism. To
investigate this hypothesis, we analyzed intra- and extracellular Abeta content
in NT2 differentiated cells incubated with 4-hydroxy-2,3-nonenal (HNE), a major
product of lipid peroxidation. In parallel, we evaluated protein kinase C (PKC)
isoenzymes activity, a signaling system suspected to modulate amyloid precursor
protein (APP) processing. Low HNE concentrations (0.1-1 microM) induced a 2-6
fold increase of intracellular Abeta production that was concomitant with
selective activation of betaI and betaII PKC isoforms, without affecting either
cell viability or APP full-length expression. Selective activation of the same
PKC isoforms was observed following NT2 differentiation. Our findings suggest
that PKC beta isoenzymes are part of cellular mechanisms that regulate production
of the intracellular Abeta pool. Moreover, they indicate that lipid peroxidation
fosters intracellular Abeta accumulation, creating a vicious neurodegenerative
loop.
PMID- 10679258
TI - Inhibition of MAP kinase kinase (MEK) results in an anti-inflammatory response in
vivo.
AB - The MAP kinase pathway has been well-characterized as a cascade of sequential
protein phosphorylation events leading to the upregulation of a variety of genes
in response to growth factors and mitogens. We are interested in the role of
these kinases in inflammation and have thus examined their activity in vivo using
TPA-induced ear edema in the mouse as a model of inflammation. We show that the
activities of both ERK-1 and ERK-2 are upregulated in this model in response to
TPA. Increased levels of ERK phosphorylation are measurable as early as 15 min
poststimulation and reach a level 8-fold over controls at 4 h. In contrast,
minimal activation of JNK or p38 is observed. Topical treatment of ears with the
MEK inhibitor, U0126, prevents ERK phosphorylation and ear swelling in a dose
dependent manner in this model. These results suggest that the MEK/ERK pathway is
important during an inflammatory response in vivo.
PMID- 10679259
TI - Zinc induces the accumulation of hypoxia-inducible factor (HIF)-1alpha, but
inhibits the nuclear translocation of HIF-1beta, causing HIF-1 inactivation.
AB - The replacement of heme iron by cobalt or nickel in a putative oxygen sensor is
supposed to reduce oxygen binding to the heme protein, resulting in HIF-1
activation and erythropoietin (EPO) induction. According to this hypothesis, zinc
might be another example of a transition metal which is capable of stimulating
EPO production. By substituting for heme iron, zinc protoporphyrin IX is
produced, which has a known low oxygen affinity. However, it has been reported
that zinc fails to induce EPO in normoxia, and that it suppresses EPO production
in hypoxic cells. This unexpected effect of zinc on EPO production is not
understood. In this study, we found that zinc induced the accumulation and
nuclear translocation of hypoxia-inducible factor (HIF)-1alpha but inhibited the
nuclear translocation of HIF-1beta, which inactivated HIF-1 and suppressed EPO
mRNA induction in hypoxic cells.
PMID- 10679260
TI - Lipopolysaccharide augments expression and secretion of vascular endothelial
growth factor in rat ventricular myocytes.
AB - Vascular endothelial growth factor (VEGF), also known as vascular permeability
factor, is highly expressed in the myocardium under various stimuli including
hypoxia and ischemia. On the other hand, lipopolysaccharide (LPS) causes systemic
inflammatory response syndrome (SIRS), which consists of systemic
pathophysiological changes related to vascular hyperpermeability. To test the
hypothesis that VEGF is one of the important mediators of SIRS, we examined
effects of LPS on the VEGF expression and secretion in cultured neonatal rat
ventricular myocytes. LPS (10 microg/ml) rapidly (within 1 h) augmented the
levels of VEGF mRNA in these cells. Pharmacological inhibition of nucleic factor
kappaB or tyrosine kinases did not affect the LPS-induced augmentation of VEGF
mRNA expression, while these treatments markedly suppressed the up-regulation of
inducible nitric oxide synthase (iNOS) expression by LPS. The VEGF concentrations
in the conditioned media were also significantly increased by the LPS treatment
of 6 h. In conclusion, LPS augments VEGF expression and secretion in rat
ventricular myocytes, suggesting that VEGF may be involved in pathogenesis of
SIRS. LPS may induce VEGF mRNA through the signaling pathways that are distinct
from those responsible for the iNOS induction.
PMID- 10679261
TI - Heme metabolism of Plasmodium is a major antimalarial target.
AB - The malarial parasite manifests unique features of heme metabolism. In the
intraerythrocyte stage it utilizes the host hemoglobin to generate amino acids
for its own protein synthesis, but polymerizes the acquired heme as a mechanism
for detoxification. At the same time the parasite synthesizes heme de novo for
metabolic use. The heme biosynthetic pathway of the parasite is similar to that
of hepatocytes and erythrocytes. However, while the parasite makes its own delta
aminolevulinate (ALA) synthase that is immunochemically different from that of
the host, it imports ALA dehydrase and perhaps the subsequent enzymes of the
pathway from the host red cell. Many schizonticidal drugs such as chloroquine and
artemisinin act by interfering with the heme metabolism of the parasite and there
is scope to design new molecules based on the unique features of this metabolic
machinery in the parasite.
PMID- 10679262
TI - Age-related decline in osteoprotegerin expression by human bone marrow cells
cultured in three-dimensional collagen sponges.
AB - With advancing age, an increase in bone resorption relative to bone formation
results in bone loss. Bone marrow stromal cells and their products support
osteoclastogenesis from hematopoietic progenitors. Another of their products,
osteoprotegerin (OPG), blocks the osteoclast-stimulatory effects of OPG ligand.
We tested the hypothesis that with advancing age there is a decrease in OPG
expression by human bone marrow cells. Bone marrow cells were obtained from 18
subjects (age range 38-84 years). Expression of mRNA transcripts of OPG was
assessed by quantitative competitive RT-PCR. Median number of OPG transcripts in
the younger group was 0. 3 zetptomoles (range 0.01 to 1.30) and was higher than
in the older group's median of 0.06 (range 0 to 0.5; p < 0.05). The decline in
the expression of OPG with age may increase the capacity of stromal/osteoblast
cells to support osteoclastogenesis.
PMID- 10679263
TI - Dramatic magnesium efflux induced by high potassium in rat thymocytes.
AB - When incubated in 150 mM KCl, rat thymocytes exhibited a very important magnesium
efflux (11.4 +/- 0.7 mmoles/liter cells/20 min, n = 29), about 90 times higher
than the physiological magnesium efflux catalyzed by the Na-Mg exchanger (0.126
+/- 0.093 mmoles/liter cells/20 min). Cells remained viable (trypan blue test)
and membrane integrity was shown by the absence of an increase in sodium
permeability. K(+)-induced magnesium efflux exhibited the following properties:
(i) it required the presence of external chloride; (ii) it was fully blocked by
DIOA, a selective KCl-cotransporter inhibitor (IC(50) = 35 microm); and (iii) it
was associated to a progressive increase in cell volume via the DIOA-sensitive K
Cl cotransporter. Such cell swelling seems to play a causal role, because (i)
hypertonic media (+400 mM sucrose) abolished K(+)-induced magnesium efflux and
(ii) hypotonic Ringer media (205 mOsm) increased both cell volume and magnesium
efflux (from a basal value of 0.35 +/- 0.03 mmoles/liter cells/20 min up to 1.44
+/- 0.24 mmoles/liter cells/20 min), even in the presence of DIOA. In conclusion,
high potassium induced a dramatic release of intracellular magnesium from rat
thymocytes. Such a phenomenon was, at least in part, caused by cell swelling via
the DIOA-sensitive K-Cl cotransporter. The nature of the magnesium transport
mechanism and its role in the transduction signal of K-Cl cotransporter
activation by cell swelling deserve further investigation.
PMID- 10679264
TI - Cloning and expression of cytochrome P450 genes belonging to the CYP4 family and
to a novel family, CYP48, in two hymenopteran insects, Trichogramma cacoeciae and
Apis mellifera.
AB - Cytochrome P450 partial sequences were isolated by PCR using genomic DNA from two
hymenopteran insects of agronomical importance, Trichogramma cacoeciae, a
parasitoid wasp, and Apis mellifera, the honeybee. Four new P450 genes were
identified: one honeybee gene belongs to the CYP4 family and was named CYP4G11;
the three other genes were from Trichogramma and belong to the CYP4 family
(CYP4G12) and to a novel family, the CYP48 one (CYP48A1 and CYP48A2). The four
genes contain a short intron (72-95 bp) at the same position as already described
for other insect species. The two genes CYP48A1 and CYP48A2 have a supernumary
intron (57-71 bp) upstream the first one. Only the two CYP4 genes were
constitutively transcribed, at a high level for CYP4G12 and at a low level for
CYP4G11. No expression was observed for CYP48A1 and CYP48A2.
PMID- 10679265
TI - The effect of water on the Fe(3+)/Fe(2+) reduction potential of heme.
AB - Hemeproteins can act as catalysts, oxygen carriers or electron conductors. The
ferric/ferrous reduction potential E(m7) of iron in the center of the prosthetic
group ranges from negative values for peroxidases to an extreme positive value
for cytochrome a(3) with Hb and Mb in the middle [1]. Proteins exercise their
influence on E(m7) in several ways: via substituents at the periphery of the
chelate structure, via the proximal ligand, and via interaction with the
surrounding medium, amino acid side chains, or polar solvents. Work on recombined
proteins and 2,4-substituted free hemes documented that the first two effects are
additive [2]. For the third effect, models of the dielectric media on a molecular
level have been successfully applied [3-5]. E(m7) has also been empirically
correlated to the degree of heme exposure to water [6-8]. The
apoprotein/porphyrin and water/porphyrin interfaces are complementary since water
molecules fill any empty space in the crevice and surround any pertinent part of
heme outside the protein boundary. The present work links to this idea by a
combination of statistical mechanics simulations and quantum mechanical
calculations comparing heme in water with heme in an apolar environment. Our
results show that polarization of the porphyrin pi-electron cloud by the field
from water dipoles influences E(m7). The dominant effect of this and other
determinates of iron electron availability is perturbations of delocalized
electron density in the porphyrin chelate, reproduced by a model where the
prosthetic group is treated as a disc of uniform electron density. The present
work is also of interest since the interfacial energy constitutes the main
barrier for heme-protein separation [9-11].
PMID- 10679266
TI - Expression of a Desulfovibrio tetraheme cytochrome c in Escherichia coli.
AB - A tetraheme cytochrome c was successfully overexpressed for the first time in
Escherichia coli. Desulfovibrio desulfuricans ATCC 27774 tetraheme cytochrome
c(3) was expressed in aerobically grown Escherichia coli cotransformed with
Escherichia coli ccm gene cluster (Arslan et al. (1998) Bioch. Biophys. Res.
Commun. 251, 744-747). The analysis of the produced cytochrome showed that the
signal peptide was correctly cleaved, the four heme groups were inserted and the
electronic structure around the heme irons was conserved, i.e., the recombinant
tetraheme cytochrome was identical to that isolated from the native source.
Contradicting previous results which indicated that Escherichia coli was only
capable of producing apocytochrome c(3) (Pollock et al. (1989) J. Gen. Microbiol.
135, 2319-2328), the present work proves unequivocally that the holoform can also
be obtained.
PMID- 10679267
TI - Human glial cell-line-derived neurotrophic factor: a structure-function analysis.
AB - Glial cell-line-derived neurotrophic factor (GDNF) is a protein known to enhance
the survival of dopaminergic and motor neurons. It has been shown to have
therapeutic potential in the treatment of Parkinson's disease and other
neurodegenerative diseases. GDNF gene was modified by deletion and insertion
mutagenesis using PCR methods. The various mutants were all highly expressed in
Escherichia coli. The recombinant proteins were purified and their survival
promoting activities were determined by motor neurons. The result showed that the
C-terminus was critical for structure stability of GDNF, and the alpha-helix,
finger1 and finger2 regions were involved in receptor binding, while the N
terminus was not essential for the biological functions of GDNF.
PMID- 10679268
TI - Molecular cloning of murine STAP-1, the stem-cell-specific adaptor protein
containing PH and SH2 domains.
AB - To identify the novel substrate of c-kit which is important for hematopoietic
stem cell self-renewal or differentiation, CD34-low/negative, Sca-1-positive, c
kit-positive, and lineage marker-negative (CD34(low/-)Sca-1(+)c-kit(+)Lin(-))
cells were sorted by a fluorescence-activated cell sorter from mouse bone marrow
cells and a yeast two-hybrid cDNA library was constructed. By screening with c
kit as bait, we cloned a novel cDNA, designed STAP-1, encoding an adaptor protein
with a Pleckstrin homology domain, the Src homology 2 (SH2) domain, and a number
of tyrosine phosphorylation sites. RT-PCR analysis revealed that STAP-1
expression is restricted in the bone marrow cell fraction expressing c-kit. The
highest expression was observed in the CD34(low/-)Sca-1(+)c-kit(+)Lin(-) stem
cell-enriched fraction. The murine myeloid cell line, M1, expressed a high level
of STAP-1. However, the expression was strongly repressed in response to leukemia
inhibitory factor (LIF) which induced monocytic differentiation of M1 cells,
suggesting that STAP-1 is associated with the undifferentiated cell type. A two
hybrid assay indicated that STAP-1 bound not only to c-kit but also to c-fms but
not to JAK2 or Pyk2. In 293 cells, STAP-1 was tyrosine-phosphorylated by
activated c-kit. An in vitro binding assay suggested that the STAP-1 SH2 domain
interacted with several tyrosine-phosphorylated proteins including c-kit and
STAT5. These suggest that STAP-1 functions as an adaptor molecule downstream of c
kit in hematopoietic stem cells.
PMID- 10679269
TI - The human PEX3 gene encoding a peroxisomal assembly protein: genomic
organization, positional mapping, and mutation analysis in candidate phenotypes.
AB - In yeasts, the peroxin Pex3p was identified as a peroxisomal integral membrane
protein that presumably plays a role in the early steps of peroxisomal assembly.
In humans, defects of peroxins cause peroxisomal biogenesis disorders such as
Zellweger syndrome. We previously reported data on the human PEX3 cDNA and its
protein, which in addition to the peroxisomal targeting sequence contains a
putative endoplasmic reticulum targeting signal. Here we report the genomic
organization, sequencing of the putative promoter region, chromosomal
localization, and physical mapping of the human PEX3 gene. The gene is composed
of 12 exons and 11 introns spanning a region of approximately 40 kb. The highly
conserved putative promoter region is very GC rich, lacks typical TATA and CCAAT
boxes, and contains potential Sp1, AP1, and AP2 binding sites. The gene was
localized to chromosome 6q23-24 and D6S279 was identified to be the closest
positional marker. As yeast mutants deficient in PEX3 have been shown to lack
peroxisomes as well as any peroxisomal remnant structures, human PEX3 is a
candidate gene for peroxisomal assembly disorders. Mutation analysis of the human
PEX3 gene was therefore performed in fibroblasts from patients suffering from
peroxisome biogenesis disorders. Complementation groups 1, 4, 7, 8, and 9
according to the numbering system of Kennedy Krieger Institute were analyzed but
no difference to the wild-type sequence was detected. PEX3 mutations were
therefore excluded as the molecular basis of the peroxisomal defect in these
complementation groups.
PMID- 10679270
TI - Apoaequorin monitors degradation of endoplasmic reticulum (ER) proteins initiated
by loss of ER Ca(2+).
AB - Apoaequorin was targeted to the cytosol, nucleus, and endoplasmic reticulum of
HeLa cells in order to determine the effect of Ca(2+) release from the ER on
protein degradation. In resting cells apoaequorin had a rapid half-life (ca. 20
30 min) in the cytosol or nucleus, but was relatively stable for up to 24 h in
the ER (t(1/2) > 24 h). However, release of Ca(2+) from the ER, initiated by the
addition of inhibitors of the ER Ca(2+)/Mg(2+) ATPase such as 2 microM
thapsigargin or 1 microM ionomycin, initiated rapid loss of apoaequorin in the
ER, but had no detectable effect on apoaequorin turnover in the cytosol nor the
nucleus. This loss of apoprotein was not the result of secretion into the
external fluid, and could not be inhibited by inhibitors of protein degradation
by proteosomes. Proteolysis of apoaequorin in cell extracts (t(1/2) < 20 min) was
completely inhibited in the presence of 1 mM Ca(2+), and this effect was
independent of the ER retention signal KDEL at the C-terminus. Proteolysis was
unaffected by the presence of selected serine protease inhibitors, or 10 microM
Zn(2+), a known caspase-3 inhibitor. The results show that apoaequorin can
monitor proteolysis of ER proteins activated by loss of ER Ca(2+). Several Ca(2+)
binding proteins exist in the ER, acting as the Ca(2+) store and chaperones. Our
results have important implications both for the role of ER Ca(2+) in cell
activation and stress and when using aequorin for monitoring free ER Ca(2+) over
long time periods.
PMID- 10679271
TI - Fungal gliotoxin targets the onset of superoxide-generating NADPH oxidase of
human neutrophils.
AB - Gliotoxin from Aspergillus, bearing a S&bond;S bond in its structure, prevented
the onset of O(-)(2) generation by the human neutrophil NADPH oxidase in response
to phorbol myristate acetate (PMA). Gliotoxin affected the activation process
harder than the activated oxidase, as shown by its stronger inhibition when added
to neutrophils prior to, than post-PMA at maximum enzyme turnover. Decreased O(
)(2) generation persisted even if cells treated with gliotoxin were subsequently
washed, with half-inhibition concentrations (IC(50)) of 5.3, and 3.5 microM for
treatments of 15 and 30 min, respectively. In addition, gliotoxin made
neutrophils reduce cytochrome c regardless of absence of PMA, through its
reaction with intracellular reductants in an oxygen-dependent process, named
redox cycling. Thus, we next tested whether preincubation of neutrophils with
gliotoxin under hypoxic conditions would relieve the inhibition of NADPH oxidase.
Instead, this prevention of redox cycling significantly favored damage to the
NADPH oxidase with an IC(50) of 0.009 microM. Moreover, conversion of gliotoxin
to its dithiol derivative by addition of reduced dithiothreitol during incubation
protected cells from losing oxidase activity. These findings support that the
disulfide form of gliotoxin targets NADPH oxidase activation.
PMID- 10679272
TI - 3-Methyladenine-DNA glycosylase I from Escherichia coli-computer modeling and
supporting experimental evidence.
AB - TagA (3-methyladenine-DNA glycosylase I) excises 3-methyadenine and 3
methylguanine from alkylated DNA. The structure of this enzyme has not yet been
determined experimentally. We propose a three-dimensional model of the TagA
protein based on the threading algorithm. The model shows that TagA is a mostly
alpha-helical protein, in agreement with circular dichroism measurements. None of
the eight cysteines present in the TagA sequence forms a disulfide bridge in the
model structure, which has also been experimentally verified with the use of
Ellman method.
PMID- 10679273
TI - In situ demonstration of inhibitory effects of hammerhead ribozymes that are
targeted to the hepatitis Bx sequence in cultured cells.
AB - Chronic hepatitis B virus (HBV) infection is endemic to several populous areas of
the world and is frequently complicated by hepatocellular carcinoma. Ribozymes
can be designed to cleave target RNA sequences specifically and show promise for
the treatment of HBV infection. Demonstration of intracellular inhibition of HBV
gene expression, essential to developing therapeutic ribozymes, has been the aim
of this investigation. We generated two vectors encoding hammerhead ribozymes
that target the HBx region of HBV. Plasmids containing intact HBV sequences or a
modification in which the preS2/S region was replaced by DNA encoding enhanced
green fluorescent protein (EGFP) were used to test ribozyme action in transfected
cells. Both ribozymes inhibited surface antigen secretion and EGFP expression
similarly. The measurement of EGFP expression is convenient to assess ribozyme
action in situ and effective targeting of HBV sequences that are common to all
HBV transcripts is potentially useful to develop strategies to counter HBV
infection.
PMID- 10679274
TI - Receptor-mediated gene delivery approach demonstrates the role of 5'-proximal DNA
region in conferring phenobarbitone responsiveness to CYP2B2 gene in rat liver in
vivo.
AB - The phenobarbitone (PB) responsiveness of the 5'-proximal region of the CYP2B1/B2
gene was examined in detail with plasmid DNA constructs containing G-free
cassette as reporter, using in vivo targeting of the same DNA constructs into rat
liver as galactosylated-polylysine complexes. The contribution of the proximal
region (-1 to -179 bp) and the positive element (-69 to -98 bp) identified
earlier in this laboratory to PB responsiveness was assessed. The results
obtained on PB treatment of rats subjected to receptor-mediated gene delivery to
liver were conclusive and dramatic, with the control (saline-treated) rats
manifesting very little expression of the reporter, reflecting the in vivo
picture of CYP2B1/B2 gene expression. The positive element conferred PB
responsiveness to homologous and heterologous promoters. Deletion of the positive
element led to elimination of PB response. The entire -179 bp region was
significantly more effective in responding to PB treatment than the region up to
98 bp, both containing one copy of the positive element. Thus, the positive
element and its flanking sequences in the 5'-proximal region are involved in
conferring PB responsiveness to the CYP2B1/B2 gene.
PMID- 10679275
TI - Clay-bridged electron transfer between cytochrome p450(cam) and electrode.
AB - We demonstrate a very fast heterogeneous redox reaction of substrate-free
cytochrome P450(cam) on a glassy carbon electrode modified with sodium
montmorillonite. The linear relationship of the peak current in the cyclic
voltammogram with the scan rate indicates a reversible one-electron transfer
surface process. The electron transfer rate is in the range from 5 to 152 s(-1)
with scan rates from 0.4 to 12 V/s, respectively. These values are comparable to
rates reported for the natural electron transfer from putidaredoxin to P450(cam).
The formal potential of adsorbed P450(cam) is -139 mV (vs NHE) and therefore
positively shifted by 164 mV compared to the potential of substrate-free
P450(cam) in solution. UV-VIS and FTIR spectra do not indicate an influence of
the clay colloidal particles on the heme and the secondary structure of P450(cam)
in solution. However, P450(cam) adsorbed on the surface of the clay-modified
electrode may undergo partial dehydration resulting in the shift of the formal
potential.
PMID- 10679276
TI - Biochemical/spectroscopic characterization and preliminary X-ray analysis of a
new aldehyde oxidoreductase isolated from Desulfovibrio desulfuricans ATCC 27774.
AB - Aldehyde oxidoreductase (AOR) activity has been found in different sulfate
reducing organisms (Moura, J. J. G., and Barata, B. A. S. (1994) in Methods in
Enzymology (Peck, H. D., Jr., and LeGall, J., Eds.), Vol. 243, Chap. 4. Academic
Press; Romao, M. J., Knablein, J., Huber, R., and Moura, J. J. G. (1997) Prog.
Biophys. Mol. Biol. 68, 121-144). The enzyme was purified to homogeneity from
extracts of Desulfovibrio desulfuricans (Dd) ATCC 27774, a sulfate reducer that
can use sulfate or nitrate as terminal respiratory substrates. The protein
(AORDd) is described as a homodimer (monomer, circa 100 kDa), contains a Mo-MCD
pterin, 2 x [2Fe-2S] clusters, and lacks a flavin group. Visible and EPR
spectroscopies indicate a close similarity with the AOR purified from
Desulfovibrio gigas (Dg) (Barata, B. A. S., LeGall, J., and Moura, J. J. G.
(1993) Biochemistry 32, 11559-11568). Activity and substrate specificity for
different aldehydes were determined. EPR studies were performed in native and
reduced states of the enzyme and after treatment with ethylene glycol and
dithiothreitol. The AORDd was crystallized using ammonium sulfate as precipitant
and the crystals belong to the space group P6(1)22, with unit cell dimensions a =
b = 156.4 and c = 177.1 A. These crystals diffract to beyond 2.5 A resolution and
a full data set was measured on a rotating anode generator. The data were used to
solve the structure by Patterson Search methods, using the model of AORDg.
PMID- 10679277
TI - Amyloid-beta peptides interact with plasma proteins and erythrocytes:
implications for their quantitation in plasma.
AB - Amyloid beta peptides are bound rapidly in the plasma complicating an accurate
assessment of their in vivo abundance by immunoassay procedures. The extent of
Abeta immunoassay interference was used to estimate the Abeta binding capacity of
purified plasma proteins, erythrocytes and whole plasma. Human serum albumin
bound Abeta peptides rapidly with a 1:1 stoichiometry and at physiological
concentrations was capable of binding over 95% of an input of 5 ng/ml Abeta.
Purified alpha2-macroglobulin was able to bind Abeta peptides and at
physiological concentration bound 73% of 5 ng/ml of Abeta. Erythrocytes also
sequestered the Abeta peptides, showing a preference for binding Abeta 1-42.
Incubation of 5 ng/ml of Abeta in plasma revealed that about 30% of the peptides
were still detectable by immunoassay, presumably reflecting the binding of Abeta
peptides with albumin and other plasma molecules. Thus, our studies reveal that
both the soluble and formed elements of the blood are capable of sequestering
Abeta peptides. To avoid underestimating plasma Abeta values, we employed an
improved column chromatography method under denaturing conditions to liberate
Abeta from its associations with plasma proteins. Quantification of Abeta 40 and
42 levels in plasma from both normal and AD individuals after chromatography
showed a large overlap between AD and control groups, despite the very large pool
of Abeta present in the AD brains. The potential origins of the plasma Abeta pool
are discussed.
PMID- 10679278
TI - Involvement of ERK in BMP-2 induced osteoblastic differentiation of mesenchymal
progenitor cell line C3H10T1/2.
AB - The signaling mechanisms responsible for bone morphogenetic protein (BMP) induced
osteoblast differentiation remains poorly understood. Previous research
demonstrated that Smad proteins are the substrates and the mediators of BMP bound
serine/threonine receptor kinase. In the present study, we examined the possible
involvement of extracellular signal-regulated kinase (Erk) in the BMP induced
osteoblast differentiation of mesenchymal progenitor cell C3H10T1/2. Our results
indicate that BMP-2 inducement increased MAP kinase activity in mesenchymal
progenitor cell line C3H10T1/2. Contrary to previous reports, this increased MAP
kinase activity showed a latent but sustained pattern. Elevation of Erk1 and Erk2
protein levels was observed simultaneously. RT-PCR results demonstrated that the
elevation of Erk protein level in BMP-2 induced cells was from the upregulation
of mRNA expression. Furthermore, upregulated Erk proteins present enhanced
phosphorylation. By using a dominant-negative Erk2 cell line, we demonstrated
that nonfunctional Erk2 partially eliminated BMP-2 induced cell proliferation and
ALP activity in the C3H10T1/2 cell. These results indicate that Erk is involved
in BMP-2 induced osteoblast differentiation. The results also demonstrate that a
latent and sustained signaling pattern exists in BMP induced signaling cascade.
PMID- 10679279
TI - Enhanced expression of cellular prion protein gene by insulin or nerve growth
factor in immortalized mouse neuronal precursor cell lines.
AB - In order to understand the fundamental and putative roles of PrP(c) in the
central nervous system, neuronal cell lines were established. Cells were
immortalized by recombinant retrovirus vector-mediated transduction of SV40 T
antigen gene. Among these, two cell lines were selected based on their RT-PCR
expressions of neuron-specific neurofilament (NF-H, NF-M) and cell morphology.
These cell lines showed the properties of neuronal progenitor cells in
antigenicity, morphology and responses to differentiating agents. Expression of
PrP(c) was detected by immunocytochemical analysis. These cell lines responded to
differentiating agents such as dibutyl cyclic AMP (dcAMP) and phorbol 12
myristate 13-acetate (PMA) before developing into neuronal-like cells. Neurite
extensions were observed 20 min after incubation with the differentiating agents.
Treatment with nerve growth factor (NGF) and insulin induced cell differentiation
and enhanced expression of PrP gene (Prnp) mRNA and protein. The latter
phenomenon was not inhibited by wortmannin, which is a specific inhibitor of
phosphatidylinositol 3-kinase. These results suggest that PrP(c) plays an
important role in the differentiation-mediated classic signaling pathway of
neuronal cell.
PMID- 10679280
TI - Green tea polyphenols: novel and potent inhibitors of squalene epoxidase.
AB - The green tea gallocatechins, (-)-epigallocatechin-3-O-gallate (EGCG) (IC(50) =
0.69 microM), (-)-gallocatechin-3-O-gallate (GCG) (IC(50) = 0.67 microM), (-)
epicatechin-3-O-gallate (ECG) (IC(50) = 1.3 microM), and theasinensin A (IC(50) =
0.13 microM), were found to be potent and selective inhibitors of rat squalene
epoxidase (SE), a rate-limiting enzyme of cholesterol biogenesis. On the other
hand, flavan-3-ols without galloyl group at C-3 did not show significant enzyme
inhibition. It was demonstrated for the first time that the cholesterol lowering
effect of green tea may be attributed to their potent SE inhibition activities.
Inhibition kinetics revealed that EGCG inhibited SE in noncompetitive (K(I) =
0.74 microM), and non-time-dependent manner. The potent enzyme inhibition would
be caused by specific binding to the enzyme, and by scavenging reactive oxygen
species required for the monooxygenase reaction.
PMID- 10679281
TI - Selective activation of antitumor activity of macrophages by the delivery of
muramyl dipeptide using a novel polynucleotide-based carrier recognized by
scavenger receptors.
AB - We have shown that muramyl dipeptide (MDP) conjugated to a 10-mer polyguanylic
acid (PolyG) is specifically internalized by macrophages through scavenger
receptor (SCR)-mediated endocytosis. Macrophages activated by PolyG-MDP displayed
about 20-fold higher cytotoxic activity against nonmacrophage tumor cells
compared to that elicited by free MDP. The PolyG-MDP was found to trigger the
secretion of higher levels of interleukin-6, interleukin-1alpha, TNF-alpha, and
nitric oxide in comparison to free MDP. Addition of antibodies directed against
IL-6 and TNF-alpha to macrophage culture completely abrogated the tumoricidal
response of PolyG-MDP, indicating that these two cytokines are primarily
responsible for bioefficacy. This general approach of PolyG as a vehicle may find
wide application in the delivery of genes and antisense oligonucleotides to
macrophages.
PMID- 10679282
TI - Expression of 5-lipoxygenase by human colorectal carcinoma Caco-2 cells during
butyrate-induced cell differentiation.
AB - Butyrate, a short-chain fatty acid, modulates proliferation and differentiation
of normal and neoplastic colonocytes. We examined the expression of 5
lipoxygenase (5-LO) and its metabolites in human colorectal carcinoma (Caco-2)
cells, exposed to differentiation-inducing doses of butyrate. Treatment with
butyrate significantly increased 5-lipoxygenase mRNA and protein in comparison to
nontreated cells. Cyclooxygenases (COX)-1 and COX-2 mRNA were not significantly
influenced by the treatment. However, 5-LO activity, low in nontreated cells,
increased only minimally after butyrate, and its metabolic product (5-HETE) was
detectable neither in control nor in treated cells. In contrast, 15-HETE (a
product of 15-LO, which is also upregulated by butyrate) rose significantly. We
conclude that, although being overexpressed by butyrate on mRNA and protein
level, 5-LO remains inactive in differentiating Caco-2 cells. This is likely to
be due either to some associated actions of butyrate, or to 5-LO-inhibition by 15
HETE, concomitantly induced by butyrate treatment.
PMID- 10679283
TI - Ras-related GTPase RhoB forces alkylation-induced apoptotic cell death.
AB - rhoB encoding a Ras-related GTPase is immediate-early inducible by genotoxic
treatments. To address the question of the physiological role of RhoB in cellular
defense, cells stably overexpressing wild-type RhoB protein were generated.
Overexpression of RhoB renders cells hypersensitive to the killing effect of
alkylating agents including antineoplastic drugs but not to UV-light and
doxorubicin. As compared to control cells, RhoB overexpressing cells revealed an
increase in the frequency of alkylation-induced apoptotic cell death. This
indicates that RhoB is involved in modulating apoptotic signaling. Furthermore,
overexpression of RhoB resulted in a prolonged transient block to DNA replication
upon MMS treatment. UV-induced replication blockage was not affected by RhoB.
Based on the data we suggest RhoB to be a novel regulatory factor which takes
influence on the level of cytotoxicity of DNA damaging drugs and forces cells to
alkylation-induced apoptosis. The data indicate that this might be due to RhoB
mediated delay in cell cycle progression upon alkylation treatment.
PMID- 10679284
TI - Intracellular supply of phospholipids for biliary secretion: evidence for a
nonvesicular transport component.
AB - Phospholipids (PL) for biliary secretion could be supplied from the endoplasmic
reticulum (ER) to the plasma membrane by cytosolic transfer proteins or transport
vesicles. Therefore, we studied whether biliary secretions of PL and
apolipoprotein A-I (apo A-I), as markers for the ER-to-Golgi vesicular transport
pathway, are tightly coupled in isolated perfused rat livers with enhanced
secretion (+60%) of PL after withdrawal of the cholesterol synthesis inhibitor
pravastatin (0.1% of chow, fed for 7 days). Blocking agents dissociated the
secretion of apo A-I and PL. Brefeldin A as well as cycloheximide inhibited
biliary secretion of apo A-I (-52%; -68%), however, not of PL. Both bilirubin
ditaurate and taurodehydrocholic acid reduced biliary secretion of PL (-27%;
79%), but not of apo A-I. The data support the concept that PL destined for
biliary secretion bypass the vesicular transport pathway of apo A-I through the
Golgi compartment, most likely via cytosolic transfer proteins.
PMID- 10679285
TI - De novo RNA synthesis catalyzed by HCV RNA-dependent RNA polymerase.
AB - The 65 kDa RNA-dependent RNA polymerase (NS5B), encoded by the hepatitis C virus
(HCV) genome, is a key component involved in viral replication. Here we provide
the direct evidence that purified HCV polymerase catalyzed de novo RNA synthesis
in a primer-independent manner using homopolymers and HCV RNA as templates. The
enzyme could utilize both polyC and polyU as templates for de novo RNA synthesis,
suggesting that NS5B specifically recognized pyrimidine bases for initiation.
More importantly, NS5B also catalyzed de novo RNA synthesis with an HCV RNA
template; the resulting nascent RNA products, smaller than the template used,
contained ATP as the first nucleotide. These results indicate that the newly
synthesized RNAs did not result from template self-priming and suggest that a
replication initiation site in the HCV RNA genome is a uridylate.
PMID- 10679286
TI - A two-hit model for development of multiple endocrine neoplasia type 2B by RET
mutations.
AB - Multiple endocrine neoplasia (MEN) type 2B mutations have been reported at
methionine 918 or alanine 883 in the tyrosine kinase domain of the RET proto
oncogene. Recently, a new combination of two germline missense mutations at
valine 804 and tyrosine 806 was identified in a patient with MEN 2B-like clinical
phenotypes including medullary thyroid carcinoma, mucosal neuroma, and marfanoid
habitus. In this case, valine 804 and tyrosine 806 were replaced with methionine
and cysteine, respectively. In the present study, biological activities of RET
with these new mutations were compared with those with known MEN 2A or MEN 2B
mutations. The transforming activity of RET with the V804M/Y806C mutation was
about 8- to 13-fold higher than that of RET with a single V804M or Y806C
mutation. Like RET with the M918T or A883F MEN 2B mutation, the transforming
activity of RET with the V804M/Y806C mutation was not affected by substitution of
phenylalanine for tyrosine 905 that abolished the activity of RET with the MEN 2A
mutation. On the other hand, substitution of phenylalanine for tyrosines 864 and
952 drastically diminished the activity of RET with the V804M/Y806C, M918T or
A883F mutation, suggesting that these three mutant proteins have similar
biological properties.
PMID- 10679287
TI - In vitro remodeling of tumor vascular endothelial cells using conditioned medium
from various tumor cells and their sensitivity to TNF-alpha.
AB - Prevention of tumor-associated blood vessel formation (angiogenesis) is a
potentially powerful strategy to treat cancer. We found that tumor vascular
endothelial cells were rearranged in vitro with conditioned culture medium
derived from tumor cells and compared the sensitivity to the effects of TNF-alpha
between normal and tumor endothelial cells. Incubation with tumor (Meth-A,
Colon26)-derived conditioned medium showed that no effect was observed on cell
growth. Tumor cells (Meth-A, Colon26, and B16BL6) only showed no sensitivity to
TNF-alpha. Normal and control endothelial cells in culture showed little
cytotoxicity in response to TNF-alpha treatment, but marked cytotoxicity of TNF
alpha was observed in endothelial cells cultured with tumor-derived conditioned
medium. Sensitivity to TNF-alpha was different depending on the type of tumor
from which the conditioned medium was derived. This difference in sensitivity was
assumed to be due to the in vivo sensitivity to TNF-alpha. The results of this
study suggested that the sensitivity of tumors to TNF-alpha is controlled by the
sensitivity of tumor vasculature.
PMID- 10679288
TI - N-Glycan structures of an osteopontin from human bone.
AB - N-Glycan structures of osteopontin (a bone matrix protein) from human bone
(lumbar vertabrate) are reported in detail. Asn-linked glycan portion was
released from 100 microg of osteopontin by digestion with glycoamidase A (from
sweet almond), and the reducing ends of the N-glycans were reductively aminated
with 2-aminopyridine. The derivatized N-glycans were separated and structurally
identified by a multidimensional mapping technique on HPLC columns. Two major N
glycan structures were also confirmed by mass spectrometry. The proposed
structures are shown below. The result should permit future comparison with the N
glycan structures of osteopontins obtained from other sources (kidney tissues,
macrophages, urinary stones, human milk, etc.).
PMID- 10679289
TI - The kinetics of copper-induced LDL oxidation depend upon its lipid composition
and antioxidant content.
AB - Copper promotes oxidation of human low-density lipoprotein (LDL) through
molecular mechanisms that are still under investigation. We employed native human
LDL, phospholipid-containing delipidated LDL ghosts, or trilinolein
reconstituted, phospholipid-containing LDL to investigate both LDL oxidation and
the associated process of copper reduction. Both LDL ghosts and trilinolein
reconstituted LDL were devoid of antioxidants and were extremely susceptible to
AAPH-induced oxidation but, paradoxically, were rather resistant to copper
mediated oxidation. The dynamic reduction of Cu(II) to Cu(I) was quantitatively
decreased in LDL ghosts and in trilinolein-reconstituted LDL, also lacking the
initial rapid reduction and the subsequent inhibition phases, due to the absence
of endogenous antioxidants. Conversely, the rate of copper reduction was linear
and likely due to lipid peroxides, either already present or formed during copper
induced oxidation. We suggest that copper undergoes redox transitions in LDL by
utilizing reducing equivalents originating from endogenous antioxidants and/or
from lipid peroxides in the LDL lipid core.
PMID- 10679290
TI - Frequency and Markov chain analysis of amino-acid sequences of human glutathione
reductase.
AB - The amino-acid sequence of human glutathione reductase was measured according to
two- and three-amino-acid sequences. The measured frequency and probability were
compared with predicted frequency and probability. Of 477 two-amino-acid
sequences in human glutathione reductase, 176 (36.897%) and 90 (18.868%)
sequences can be explained by the predicted frequency and the predicted
probability according to a purely random mechanism. Of 477 measured first Markov
transition probabilities for the second amino acid in two-amino-acid sequences, 1
(0.210%) measured first Markov transition probability matches the predicted
conditional probability and can therefore be explained by a purely random
mechanism. No more than two-amino-acid sequences can be explained by a purely
random mechanism.
PMID- 10679291
TI - Cardiac type cGMP-inhibited phosphodiesterase (PDE3A) gene structure: similarity
and difference to adipocyte type PDE3B gene.
AB - Phosphodiesterase type 3 isoforms, PDE3A and 3B, are expressed primarily in
cardiovascular and adipose tissues, respectively. We previously reported a
shorter transcript of 4.4-kb PDE3A which is predominantly transcribed in human
placenta, whereas a full-length 7. 6-kb transcript corresponding to the cardiac
PDE3A cDNA has not been characterized. Due to unfortunate circumstances created
by changes in PDE3 nomenclature, PDE3B gene structure previously reported used
PDE3A in its title. Here, we describe PDE3A gene structure, which comprises 16
exons spanning over 130 kb on chromosome 12p12. Two PDE3 isoforms share similar
gene organization, but localize to different chromosomes. The most distal
transcription initiation site of the PDE3A gene is approximately 1071 bases
upstream of the ATG site, suggesting that exon 1 consists of 1071 and 960 bp of
untranslated and translated sequences, respectively. The proximal 5'-flanking
region, which does not contain TATA-like sequences, exhibited weak but
significant promoter activity. Results suggest potential involvement of distal
promoter/enhancer and translational regulation for expression of the 7.6-kb
transcript.
PMID- 10679292
TI - Apolipoprotein E and apolipoprotein D expression in a murine model of singlet
oxygen-induced cerebral stroke.
AB - Apolipoprotein E (apoE)-deficient mice exhibit neuronal abnormalities similar to
those in Alzheimer's disease and enhanced sensitivity to stroke-associated
injuries. Here, we show that apoE deficiency results in impaired
microglia/macrophage recruitment and accumulation after cerebral infarct.
Astrogliosis and apolipoprotein D (apoD) expression are unaffected, suggesting
that the neurological abnormalities of apoE-deficient mice could be due to
impaired microglia/macrophage recruitment/accumulation, which is important for
the clearance of neurodegenerative products via reverse cholesterol transport. To
our knowledge, the results presented herein provide the first experimental
evidence that brain microglia/macrophage recruitment/accumulation is affected by
apoE deficiency. The insights gained from this study should facilitate the
elucidation of the role of apoE in neurological disorders such as dementia with
stroke and Alzheimer's disease.
PMID- 10679293
TI - Survival and differentiation of cultured retinal progenitors transplanted in the
subretinal space of the rat.
AB - We have shown that embryonic retina contains progenitors which display stem cell
properties in vitro. These cells are proliferative and in addition to expressing
the neuroectodermal marker, nestin, are multipotential. These properties and the
fact that the putative stem cells can differentiate as photoreceptors when
exposed to conducive environment identify them as a viable transplantation
reagents to address degenerative retinal diseases. Here we report the survival
and differentiation of cultured retinal progenitors upon subretinal
transplantation. The retinal progenitor grafts, either as neural spheres or in
the form of dissociated cells, survived without disrupting the morphology and
laminar organization of the host retina. They did not form rosettes, the
morphological barrier to the reconstruction of the normal anatomy of the retina.
In addition, transplanted progenitors expressed photoreceptor-specific markers,
suggesting that progenitors have the potential to differentiate as
photoreceptors. Our observations suggest that cultured retinal progenitors can be
a viable reagents for therapeutic transplantation.
PMID- 10679294
TI - An evaluation of the expression, subcellular localization, and function of rab4
in the exocrine pancreas.
AB - The small GTP-binding protein, rab4, is involved in recycling of transferrin
receptors and translocation of GLUT4. Recent studies suggest that rab4 controls
regulated exocytosis in the exocrine pancreas. We conducted the present study to
further investigate the role of rab4 in the exocrine pancreas. We found that the
exocrine pancreas expresses two rab4 immunoanalogs, one of approximately 28 kDa
identified previously in neonatal glands, and one of approximately 24 kDa which
is similar to rab4 characterized in other systems. The latter species was mostly
membrane-anchored and localized to endosome-like structures in a supranuclear
region that was immunopositive for the transferrin receptor. The approximately 24
kDa rab4 form also localized to the apical plasmamembrane, and this
immunofluorescence increased greatly in tissue challenged with a secretagogue. We
propose that the approximately 24-kDa rab4 species is involved in compensatory
membrane retrieval following regulated exocytosis, and that rab4-positive
endocytic vesicles move through a supranuclear recycling compartment.
PMID- 10679295
TI - A non-transmembrane form of Jagged-1 regulates the formation of matrix-dependent
chord-like structures.
AB - Jagged-Notch interactions regulate a transmembrane ligand-receptor signaling
pathway involved in the regulation of cell fate determination as well as myoblast
and endothelial cell differentiation. To further examine the role of the
transmembrane ligand, Jagged-1, in the regulation of cell differentiation, we
stably transfected NIH 3T3 cells with a truncated form of Jagged(J)-1, which
results in the secretion of a soluble(s) form of the protein. Comparison of gene
expression by serial analysis demonstrated that among the 227 transcripts
differentially regulated in the sJ-1 transfectants, the expression of the pro
alpha-2(I) collagen transcript and pro-alpha-1(I) collagen translation product
was predominantly repressed in sJ-1 transfectants. When plated on extracellular
matrices, sJ-1 transfectants formed prominent chord-like structures on type I
collagen but not on fibrin, fibronectin, or vitronectin. While the sJ-1
transfectants exhibited growth kinetics similar to control cells and were unable
to grow in soft agar, the cells were less sensitive to contact inhibition of
growth in vitro and sJ-1 allografts formed tissue masses in nude mice after a
prolonged latency period and exhibited an abundance of host-derived microvascular
endothelial cells. These data suggest that J-1 may be able to modulate, in a
matrix-dependent manner, the organization of cell to cell interactions including
its ability to promote the development of chord-like structures.
PMID- 10679296
TI - Association of EXT1 and EXT2, hereditary multiple exostoses gene products, in
Golgi apparatus.
AB - We prepared the specific antibodies for EXT1 and EXT2, hereditary multiple
exostoses (HME) gene products, and characterized their expression, subcellular
localization, and protein association among EXT members. Biochemical analyses
indicate that EXT1 and EXT2 can associate and form homo/hetero-oligomers in vivo
with or without HME-linked mutations, EXT1 (R340C) and EXT2 (D227N), when
exogenously expressed in COS-7 cells. An immunocytochemical analysis showed that
both EXT1 and EXT2 localized in Golgi apparatus, irrespective of HME mutations.
An immunohistochemical analysis on developing bones further showed that both EXT1
and EXT2 were concomitantly expressed in hypertrophic chondrocytes of forelimb
bones from 1-day-old neonatal mouse, but down-regulated in maturing chondrocytes
of developing cartilage from 21-day-old mouse. Taken together with the recent
finding that EXTs encode for the glycosyltransferase required for the synthesis
of heparan sulfate [Lind, T., Tufaro, F., McCormick, C., Lindahl, U., and
Lindholt, K. (1998) J. Biol. Chem. 273, 26265-26268], our results implied a
molecular basis that a HME-linked mutation found in EXT genes could interfere the
physiological function(s) of EXT homo/hetero-oligomers as glycosyltransferases in
the developing bones of HME patients.
PMID- 10679297
TI - Direct detection of apoptotic cells in peripheral blood from highly pathogenic
SHIV-inoculated monkey.
AB - Apoptosis in peripheral blood leukocytes (PBL) has been estimated by the
enhancement of spontaneous apoptosis after in vitro culture, because apoptotic
cells have not been observed directly in freshly isolated PBL in the course of
HIV/AIDS. In monkeys infected with a highly pathogenic simian/human
immunodeficiency virus (SHIV), which corresponds to rapid progressors of HIV
infection, a high frequency of apoptotic cells was directly detected in fresh PBL
by electron-microscopic studies. Peripheral blood apoptosis transiently occurred
after intense plasma viremia, and peaking at 3 weeks postinfection; occurrence
was not limited specifically to lymphocytes, but also occurred in other types of
leukocytes. Apoptosis in peripheral lymph nodes was also detected following
intense plasma viremia. However, the in vivo apoptosis was not detected in
nonpathogenic SHIV-infected monkeys that showed no cell loss. Thus, we directly
showed the apoptosis of PBL, which might be associated with pathogenic SHIV
produced during the time of plasma viremia.
PMID- 10679298
TI - Human growth hormone stimulates proteinase activities of rabbit bone cells via
IGF-I.
AB - Human growth hormone (hGH) and human insulin-like growth factor-I (hIGF-I) are
known to have a marked influence on osteoclastic formation and bone resorption in
an unfractionated rabbit bone cell model. This study investigated the effects of
both of these factors on the induction of cysteine-proteinases and matrix
metalloproteinase-2 (MMP-2) and MMP-9. After 4 days of rabbit bone cell culture,
hGH and hIGF-I significantly modulated cathepsin, MMP-9 (latent form) and MMP-2
(active form) activities. Similar studies were performed in the presence of
parathyroid hormone (hPTH). hPTH increased MMP-2 and MMP-9 activities whereas it
had no effect on the production of cathepsins by bone cells. When neutralizing
anti-hIGF-1 antiserum was added to the culture, the stimulatory effects of hGH
were totally abolished, indicating that hGH-modulated cathepsin and
metalloproteinase activities were partly mediated by local hIGF-I secretion.
Cysteine-proteinase activities released by purified osteoclasts were very low and
were not modulated by hGH and h-IGF-I. However, hIGF-I but not hGH increased MMP
2 and MMP-9 activities released by purified osteoclasts. It may be concluded that
hGH markedly stimulates the expression of proteinases in total rabbit bone cells
via local hIGF-I production by stromal cells. Cysteine-proteinase activities are
mainly produced by non-osteoclastic cells, while MMP-2 and MMP-9 modulated by
hIGF-I are mainly expressed by osteoclastic cells.
PMID- 10679299
TI - Binding domain for p21(WAF1) on the polypeptide chain of the protein kinase CK2
beta-subunit.
AB - Protein kinase CK2 is a ubiquitous serine/threonine kinase which is involved in
many proliferation-related processes in the cell. It is composed of two
regulatory beta-subunits and two catalytic alpha-subunits. Its regulation still
remains mysterious in spite of many years of intense research. One of its
regulators is the cdk inhibitory molecule p21(WAF1)-a protein which is expressed
in situations of genotoxic stress. p21(WAF1) binds to the beta-subunit of CK2 and
inhibits the activity of CK2. Using deletion mutants of CK2 beta as well as a
peptide library consisting of 15-amino-acid-long peptides derived from the
polypeptide chain of CK2 beta we mapped the binding region for p21(WAF1) on the
polypeptide chain of CK2 beta. We localized an amino-terminal and a carboxy
terminal binding domain. Binding of p21(WAF1) to both regions of the CK2 beta
subunit interferes with the phosphotransferase activity of the CK2 holoenzyme.
PMID- 10679300
TI - Promoter usage for insulin-like growth factor-II in cancerous and benign human
breast, prostate, and bladder tissues, and confirmation of a 10th exon.
AB - Upregulation of insulin-like growth factor (IGF)-II expression has been reported
for a variety of childhood and adulthood tumors. We determined IGF-II gene
promoter usage in human cancerous and benign tissues by semiquantitative RT-PCR
using P1-P4-specific primers. Although the human IGF-II gene structure is
commonly thought to consist of nine exons and four promoters, we detected
substantial utilization of a previously reported exon 4b, which is downstream of
exon 4. Thus, exon 4b was intensively studied using 4b-specific primers. IGF-II
gene promoter usage is highly variable in malignant and benign breast, prostate,
and bladder tissues. While a majority of samples utilized P2-P4 promoters in a
variety of combinations, when quantitated, P3 and P4 promoters were much more
active than P2 promoter. This study not only demonstrated that IGF-II gene
promoter usage is highly variable in malignant and benign tissues, but suggested
that alternatively spliced exon 4b should be recognized as a 10th exon.
PMID- 10679301
TI - Three rat brain alternative splicing dynamin-like protein variants: interaction
with the glycogen synthase kinase 3beta and action as a substrate.
AB - Dynamin-like protein, a large GTP-binding protein, has recently been cloned, and
studies have shown that it may be involved in the formation of coated vesicles.
In this report, three different alternatively spliced dynamin-like protein
variants (DLP1-WT, -11, and -37) from rat brain were identified by reverse
transcription/polymerase chain reaction (RT-PCR). One novel rat alternatively
spliced variant (DLP1-37), not described previously, was identified. We examined
the interaction of these three rat brain dynamin-like protein variants with
glycogen synthase kinase 3beta (Gsk-3beta) using the yeast two-hybrid screening,
in vitro binding assay, and immunoprecipitation analysis. It was found that all
three examined rat brain dynamin-like protein variants can bind to Gsk-3beta.
Moreover, in vitro kinase (phosphorylation) assay showed that mammalian dynamin
like protein acts as a substrate for glycogen synthase kinase 3beta. These data
suggest that Gsk-3beta may participate in a functional role in dynamin-like
proteins in vesicle trafficking.
PMID- 10679302
TI - High extracellular calcium concentrations directly stimulate osteoclast
apoptosis.
AB - Although the inhibitory effects of high extracellular calcium concentrations
([Ca](e)) on osteoclastic bone resorption have been known for several years, the
exact mechanism remains poorly understood. The present study was performed to
investigate the possible effect of [Ca](e) on osteoclast apoptosis. Using highly
purified rabbit osteoclasts, we have shown that calcium directly promotes
apoptosis in a dose-dependent manner which correlates with the dose range of
calcium for the inhibition of bone resorption. A time-course experiment of
apoptotic changes of osteoclasts cultured in presence of 1.8 or 20 mM calcium
showed a significant difference after as early as 8 h of culture. After 72 h of
culture, we observed that 80% of the cells cultured in the presence of 20 mM
calcium displayed the typical features of apoptosis compared to only 20% in the
medium containing 1.8 mM calcium. Calcium channel blockers and ryanodine
abrogated the effects of [Ca](e) on apoptosis while neomycin, a calcium-sensing
receptor agonist, did not alter cell viability. Taken together, these results
suggest that calcium influx is involved in calcium-induced osteoclast apoptosis.
Our results are consistent with the concept that in the presence of high [Ca](e)
generated during bone demineralization, osteoclasts are subjected to negative
feedback regulation due, at least in part, to the induction of apoptosis.
PMID- 10679303
TI - Characterization of endopeptidase activity of tripeptidyl peptidase-I/CLN2
protein which is deficient in classical late infantile neuronal ceroid
lipofuscinosis.
AB - Endopeptidase activities of the CLN2 gene product (Cln2p)/tripeptidyl peptidase I
(TPP-I), purified from rat spleen, were studied using the synthetic fluorogenic
substrates. We designed and constructed decapeptides, based on the known sequence
cleavage specificities of bacterial pepstatin-insensitive carboxyl proteases
(BPICP). MOCAc-Gly-Lys-Pro-Ile-Pro-Phe-Phe-Arg-Leu-Lys(Dnp)r-NH(2) is readily
hydrolyzed by Cln2p/TPP-I (K(cat)/K(m) = 7.8 s(-1) mM(-1)). The enzyme had a
maximal activity at pH 3.0 for an endopeptidase substrate, but at pH 4.5 with
respect to tripeptidyl peptidase activity. Both endopeptidase and tripeptidyl
peptidase activities were strongly inhibited by Ala-Ala-Phe-CH(2)Cl, but not
inhibited by tyrostatin, an inhibitor of bacterial pepstatin-insensitive carboxyl
proteases, pepstatin, or inhibitors of serine proteases. Fibroblasts from
classical late infantile neuronal ceroid lipofuscinosis patients have less than
5% of the normal tripeptidyl peptidase activity and pepstatin-insensitive
endopeptidase activity. Cln2p/TPP-I is a unique enzyme with both tripeptidyl
peptidase and endopeptidase activities for certain substrate specificity.
PMID- 10679304
TI - In vitro binding of nucleolin to double-stranded telomeric DNA.
AB - We have purified a 100 kDa protein, resolved in a Southwestern binding screen of
total nuclear proteins from Hela cells with double-stranded human telomeric
probe. A polyclonal antiserum raised by this protein recognizes purified
nucleolin and stains nucleoli in growing Hela cells. We demonstrate that a
truncated form of human nucleolin and a purified deletion derivative of mouse
nucleolin bind in vitro to duplex telomeric DNA. This study suggests a new link
between telomeres and the nucleolus.
PMID- 10679305
TI - MPP(+)-induced mitochondrial dysfunction is potentiated by dopamine.
AB - MPP(+), the major metabolite of the Parkinsonism-inducing compound MPTP,
responsible for the destruction of the nigrostriatal pathway in primates and
rodents, has been assayed in isolated rat liver mitochondria in the presence of
physiological concentrations of dopamine or analogous concentrations of melanin
dopamine. 5 microM MPP(+) in the presence of 70 microM dopamine or melanin
dopamine, but not alone, decreased the heat production and oxygen consumption of
a mitochondrial suspension activated with succinate and ADP. Both dopamine and
oxidized dopamine plus MPP(+) also decreased the mitochondrial reductive power
measured with MTT. Mitochondrial swelling was observed, associated with an
increase in membrane mitochondrial potential, as a synergistic effect between low
concentrations of MPP(+) and dopamine. It is suggested that cytosolic dopamine,
by itself or via its autooxidation products, may play a relevant role in the
mitochondrial toxicity of MPP(+). A failure in the regulation of the
storage/release of dopamine could aggravate a mitochondrial damage and trigger
the neurodegenerative process underlying MPTP toxicity and Parkinson's disease.
PMID- 10679306
TI - Mouse peroxiredoxin V is a thioredoxin peroxidase that inhibits p53-induced
apoptosis.
AB - We have identified human and mouse peroxiredoxin V (Prx-V) by virtue of the
sequence homologies to yeast peroxisomal antioxidant enzyme PMP20. Prx-V
represents the fifth of the six currently known subfamilies of mammalian
peroxiredoxins. It is a novel organellar enzyme that has orthologs in bacteria.
Biochemically, Prx-V is a thioredoxin peroxidase. One important aspect of p53
function in mammalian cells involves induction of apoptosis likely mediated by
redox. We show that overexpression of Prx-V prevented the p53-dependent
generation of reactive oxygen species. Likewise, Prx-V inhibited p53-induced
apoptosis. Thus, Prx-V is critically involved in intracellular redox signaling.
PMID- 10679307
TI - Induction of COX-2 expression by nitric oxide in rheumatoid synovial cells.
AB - Prostaglandins formed by cyclooxygenase (COX) enzymes are important mediators of
inflammation. The contribution of inducible COX-2 in the rheumatoid synovium is
well documented. In this study, we evaluated the contribution of nitric oxide
(NO) to COX-2 expression in rheumatoid synovial cells. Exposure of rheumatoid
synovial cells to a NO donor, SNAP, induced COX-2 protein expression in a dose
dependent manner. RT-PCR analysis also demonstrated that COX-2 mRNA was induced
in SNAP-treated synovial cells. Dexamethasone at therapeutic concentrations
markedly inhibited this NO-mediated COX-2 expression in synovial cells. In
contrast to its effect on COX-2 expression, SNAP did not affect the constitutive
expression of COX-1 in rheumatoid synovial cells. Our findings suggest that NO is
an important modulator of COX-2 expression and that glucocorticoids exert their
anti-inflammatory action in rheumatoid synovium, at least in part, by suppression
of COX-2 induction.
PMID- 10679308
TI - Cloning and characterization of a gene, mpsA, encoding a protein associated with
intracellular magnetic particles from Magnetospirillum sp. strain AMB-1.
AB - Proteins located within the lipid bilayer, surrounding the intracellular
bacterial magnetic particles (BMP) from Magnetospirillum sp. AMB-1, were
separated using SDS-PAGE. Several major proteins of approximate molecular weight
66.2, 35.6, and 24.8 kDa were identified. The N-terminal amino acid sequence of
one of these proteins, designated MpsA, was determined and used to design a pair
of PCR primers which amplified a 105 bp DNA fragment from AMB-1 genomic DNA. Gene
walking, using anchored PCR, was used to determine the complete nucleotide
sequence (954 bp) of the mpsA gene. The mpsA encodes a 317 amino acid protein
which does not have an N-terminal cytoplasmic transport signal sequence.
Intracellular localization studies were carried out using an mpsA-luc gene fusion
expressed in AMB-1 following gene transfer by conjugation. The gene fusion was
constructed by cloning a 1.6 kb mpsA fragment upstream of luc in the conjugal
plasmid pKLC. The MpsA-Luc fusion protein was preferentially located on the
magnetic particle membrane. Although the function of MpsA remains unknown,
homology searches suggest similarity with the alpha subunit of acetyl-CoA
carboxylase and the CoA-binding motif.
PMID- 10679309
TI - Identification of viral macrophage inflammatory protein (vMIP)-II as a ligand for
GPR5/XCR1.
AB - Lymphotactin is unique among chemokines in that it contains only two of four
conserved cysteines and may possess a structure less constrained than other
chemokines. The viral chemokine vMIP-II, which presumably has a structure similar
to that of CC chemokines has been shown to inhibit many chemokine receptors, but
its activity at GPR5/XCR1 has not been described. Interestingly, vMIP-II (but not
vMIP-I) was found to be a potent antagonist of lymphotactin activity at
GPR5/XCR1, extending the range of chemokine classes that this viral protein is
known to inhibit to include the C class chemokine. In addition, we have extended
previous analyses of GPR5/XCR1 expression and show that this receptor is
expressed in leukocyte cells previously shown to be responsive to lymphotactin.
PMID- 10679310
TI - Pyrrolidine dithiocarbamate induces apoptosis by a cytochrome c-dependent
mechanism.
AB - Pyrrolidine dithiocarbamate (PDTC) is a synthetic antioxidant molecule, which has
been recently proposed as an antitumoral agent on the basis of its capability of
inducing apoptosis. We investigated the effect of PDTC on the proliferation and
survival of the promyelocitic cell line HL-60. Concentration as low as 10 microM
of PDTC induces a significant reduction of the growth rate and the
contemporaneous activation of the apoptotic process. Programmed cell death was
demonstrated by biochemical analyses, including the activation of procaspase 3
and the cleavage of poly(ADP-ribose) polymerase (PARP). PDTC-dependent apoptosis
was associated with an early release of cytochrome c from mitochondria, while the
involvement of pathways due to cell death receptors engagement was ruled out by
detailed time-course analyses of caspases 3 and 8 activation. Moreover, no up
regulation of p21(CIP1) level, a pivotal cyclin-dependent kinase inhibitor,
occurred at PDTC concentration able to induce apoptosis. Finally, in vitro
incubation of purified mitochondria with PDTC demonstrated that the molecule is
directly able to induce cytochrome c release from the intermembrane space, thus
confirming that mitochondria are a primary cellular target of the molecule.
PMID- 10679312
TI - Epstein-Barr virus: Co-opting B-cell memory and migration.
AB - Epstein-Barr virus, a B-lymphotropic human herpesvirus, persists in vivo by
entering the long-lived memory B-cell compartment. Work with genetically modified
mice suggests that the viral latent membrane protein LMP1 might allow infected B
cells to access the memory compartment by an unusual route.
PMID- 10679311
TI - Xenopus and chicken sperm contain a cytosolic soluble protein factor which can
trigger calcium oscillations in mouse eggs.
AB - There is evidence showing that at fertilization the sperm introduces into egg
cytoplasm a protein-based cytosolic factor, which serves as the physiological
trigger for inducing Ca(2+) oscillations in mammalian eggs. Here we show that
sperm of nonmammalian vertebrates also contain a cytosolic protein factor that
can induce Ca(2+) oscillations when introduced into mammalian eggs. We have
observed that cytosolic extracts derived from Xenopus or chicken sperm could
induce mouse eggs to undergo Ca(2+) oscillations similar to those induced by
bovine sperm extracts. The factor responsible for inducing Ca(2+) oscillations
was of high molecular weight and heat- or proteinase K-labile. We show that 0.5
chicken sperm-equivalents or 1-2 Xenopus sperm-equivalents of the extracts had
enough activity to trigger Ca(2+) oscillations in mouse eggs. Our findings
illustrate that although Xenopus, chicken, and mammals are evolutionarily
divergent species, the function of the sperm protein factor in triggering Ca(2+)
oscillations in mammalian eggs appears not to be species specific in vertebrates.
PMID- 10679313
TI - Axon regeneration: Vaccinating against spinal cord injury.
AB - Myelin is a potent inhibitor of axon regeneration, but has been viewed as just
one of many factors that prevent regeneration after injury. So it comes as a
surprise that immunization against myelin has been found to allow extensive axon
regeneration after injury, without apparent autoimmune-induced demyelination.
PMID- 10679314
TI - Neurotransmission: Chemical and electrical interneuron coupling.
AB - Recent studies have described the coupling between pairs of neocortical
interneurons involving both electrical and chemical transmission; these new
results may have important implications for the mechanisms underlying neuronal
synchrony and rhythmic activity in the brain.
PMID- 10679315
TI - Seed plant phylogeny: Demise of the anthophyte hypothesis?
AB - Recent molecular phylogenetic studies indicate, surprisingly, that Gnetales are
related to conifers, or even derived from them, and that no other extant seed
plants are closely related to angiosperms. Are these results believable? Is this
a clash between molecules and morphology?
PMID- 10679316
TI - Protein folding: Thickening the broth.
AB - Recent results support the notion that macromolecular 'crowding' enhances protein
aggregation, at the expense of correct folding. The results can be rationalised
in terms of kinetic competition between distinct processes, taking into account
the relative influence of crowding on each process.
PMID- 10679317
TI - Intracellular signalling: Is PIP(2) a messenger too?
AB - The phospholipid phosphatidylinositol (4,5) bisphosphate (PIP(2)) has recently
been shown to act downstream of the small G proteins Rac and Arf. Different
effectors may be employed in each case, suggesting that PIP(2) has multiple
signalling roles.
PMID- 10679318
TI - Signal transduction: Life, the universe and ... development.
AB - Glycogen synthase kinase 3 (GSK-3) is a key component of the Wnt signalling
pathway, among others, and is known to be regulated by inhibition. Now a novel,
dual specificity protein kinase known as Zaphod kinase has been discovered that
activates GSK-3 by tyrosine phosphorylation.
PMID- 10679319
TI - Quantitative genetics: Resolving wing shape genes.
AB - Recent high-resolution quantitative mapping experiments aimed at elucidating the
genetics of natural variation for wing shape in fruit-flies suggest that very
many genes can subtly influence the trait.
PMID- 10679320
TI - Molecular motors: Kinesin's dynamically dockable neck.
AB - Kinesin is a molecular walking machine with two identical motor heads connected
to a coiled-coil tail. Details of the coordination mechanism, which causes
kinesin to walk directionally, and the tracking mechanism, which guides each
detaching head to its next site on the microtubule, are beginning to emerge.
PMID- 10679321
TI - Activating the DNA damage checkpoint in a developmental context.
AB - BACKGROUND: Studies in unicellular systems have established that DNA damage by
irradiation invokes a checkpoint that acts to stall cell division. During
metazoan development, the modulation of cell division by checkpoints must occur
in the context of gastrulation, differential gene expression and changes in cell
cycle regulation. To understand the effects of checkpoint activation in a
developmental context, we examined the effect of X-rays on post-blastoderm
embryos of Drosophila melanogaster. RESULTS: In Drosophila, DNA damage was
previously found to delay anaphase chromosome separation during cleavage cycles
that lack a G2 phase. In post-blastoderm cycles that included a G2 phase, we
found that irradiation delayed the entry into mitosis. Gastrulation and the
developmental program of string (Cdc25) gene expression, which normally regulates
the timing of mitosis, occurred normally after irradiation. The radiation-induced
delay of mitosis accompanied the exclusion of mitotic cyclins from the nucleus.
Furthermore, a mutant form of the mitotic kinase Cdk1 that cannot be inhibited by
phosphorylation drove a mitotic cyclin into the nucleus and overcame the delay of
mitosis induced by irradiation. CONCLUSIONS: Developmental changes in the cell
cycle, for example, the introduction of a G2 phase, dictate the response to
checkpoint activation, for example, delaying mitosis instead of or in addition to
delaying anaphase. This unprecedented finding suggests that different mechanisms
are used at different points during metazoan development to stall cell division
in response to checkpoint activation. The delay of mitosis in post-blastoderm
embryos is due primarily to inhibitory phosphorylation of Cdk1, whereas nuclear
exclusion of a cyclin-Cdk1 complex might play a secondary role. Delaying cell
division has little effect on gastrulation and developmentally regulated string
gene expression, supporting the view that development generally dictates cell
proliferation and not vice versa.
PMID- 10679322
TI - Rsk1 mediates a MEK-MAP kinase cell survival signal.
AB - BACKGROUND: Growth factors activate an array of cell survival signaling pathways.
Mitogen-activated protein (MAP) kinases transduce signals emanating from their
upstream activators MAP kinase kinases (MEKs). The MEK-MAP kinase signaling
cassette is a key regulatory pathway promoting cell survival. The downstream
effectors of the mammalian MEK-MAP kinase cell survival signal have not been
previously described. RESULTS: We identify here a pro-survival role for the
serine/threonine kinase Rsk1, a downstream target of the MEK-MAP kinase signaling
pathway. In cells that are dependent on interleukin-3 (IL-3) for survival,
pharmacological inhibition of MEKs antagonized the IL-3 survival signal. In the
absence of IL-3, a kinase-dead Rsk1 mutant eliminated the survival effect
afforded by activated MEK. Conversely, a novel constitutively active Rsk1 allele
restored the MEK-MAP kinase survival signal. Experiments in vitro and in vivo
demonstrated that Rsk1 directly phosphorylated the pro-apoptotic protein Bad at
the serine residues that, when phosphorylated, abrogate Bad's pro-apoptotic
function. Constitutively active Rsk1 caused constitutive Bad phosphorylation and
protection from Bad-modulated cell death. Kinase-inactive Rsk1 mutants antagonize
Bad phosphorylation. Bad mutations that prevented phosphorylation by Rsk1 also
inhibited Rsk1-mediated cell survival. CONCLUSIONS: These data support a model in
which Rsk1 transduces the mammalian MEK-MAP kinase signal in part by
phosphorylating Bad.
PMID- 10679323
TI - Ordered assembly of roX RNAs into MSL complexes on the dosage-compensated X
chromosome in Drosophila.
AB - BACKGROUND: In the male Drosophila, the X chromosome is transcriptionally
upregulated to achieve dosage compensation, in a process that depends on
association of the MSL proteins with the X chromosome. A role for non-coding RNAs
has been suggested in recent studies. The roX1 and roX2 RNAs are male-specific,
non-coding RNAs that are produced by, and also found associated with, the dosage
compensated male X chromosome. Whether roX RNAs are physically part of the MSL
complex has not been resolved. RESULTS: We found that roX RNAs colocalize with
the MSL proteins and are highly unstable unless the MSL complex is coexpressed,
suggesting a physical interaction. We were able to immunoprecipitate roX2 RNA
from male tissue-culture cells with antibodies to the proteins Msl1 and Mle,
consistent with an integral association with MSL complexes. Localization of roX1
and roX2 RNAs in mutants indicated an order of MSL-complex assembly in which roX2
RNA is incorporated early in a process requiring the Mle helicase. We also found
that the roX2 gene, like roX1, is a nucleation site for MSL complex spreading
into flanking chromatin in cis. CONCLUSIONS: Our results support a model in which
MSL proteins assemble at specific chromatin entry sites (including the roX1 and
roX2 genes); the roX RNAs join the complex at their sites of synthesis; and
complete complexes spread in cis to dosage compensate most genes on the X
chromosome.
PMID- 10679324
TI - Type Ialpha phosphatidylinositol-4-phosphate 5-kinase mediates Rac-dependent
actin assembly.
AB - Action polymerization is essential for a variety of cellular processes including
movement, cell division and shape change. The induction of actin polymerization
requires the generation of free actin filament barbed ends, which results from
the severing or uncapping of pre-existing actin filaments [1] [2], or de novo
nucleation, initiated by the Arp2/3 complex [3] [4] [5] [6] [7]. Although little
is known about the signaling pathways that regulate actin assembly, small GTPases
of the Rho family appear to be necessary [8] [9] [10] [11]. In thrombin
stimulated platelets, the Rho family GTPase Rac1 induces actin polymerization by
stimulating the uncapping of actin filament barbed ends [2]. The mechanism by
which Rac regulates uncapping is unclear, however. We previously demonstrated
that Rac interacts with a type I phosphatidylinositol-4-phosphate 5-kinase (PIP 5
kinase) in a GTP-independent manner [12] [13]. Because PIP 5-kinases synthesize
phosphatidylinositol-4,5-bisphosphate (PI(4,5)P(2)), a lipid that dissociates
capping proteins from the barbed ends of actin filaments [14] [15] [16], they are
good candidates for mediating the effects of Rac on actin assembly. Here, we have
identified the Rac-associated PIP 5-kinase as the PIP 5-kinase isoforms alpha and
beta. When added to permeabilized platelets, PIP 5-kinase alpha induced actin
filament uncapping and assembly. In contrast, a kinase-inactive PIP 5-kinase
alpha mutant failed to induce actin assembly and blocked assembly stimulated by
thrombin or Rac. Furthermore, thrombin- or Rac-induced actin polymerization was
inhibited by a point mutation in the carboxyl terminus of Rac that disrupts PIP 5
kinase binding. These results demonstrate that PIP 5-kinase alpha is a critical
mediator of thrombin- and Rac-dependent actin assembly.
PMID- 10679325
TI - Role of proton gradients and vacuola H(+)-ATPases in the refilling of
intracellular calcium stores in exocrine cells.
AB - Numerous hormones and neurotransmitters activate cells by increasing cytosolic
calcium concentration ([Ca(2+)](i)), a key regulatory factor for many cellular
processes. A pivotal feature of these Ca(2+) signals is the release of Ca(2+)
from intracellular stores, which is followed by activation of extracellular
calcium influx, allowing refilling of the stores by SERCA pumps associated with
the endoplasmic reticulum. Although the mechanisms of calcium release and calcium
influx have been extensively studied, the biology of the Ca(2+) stores is poorly
understood. The presence of heterogeneous calcium pools in cells has been
previously reported [1] [2] [3]. Although recent technical improvements have
confirmed this heterogeneity [4], knowledge about the mechanisms underlying
Ca(2+) transport within the stores is very scarce and rather speculative. A
recent study in polarized exocrine cells [5] has revealed the existence of Ca(2+)
tunneling from basolateral stores to luminal pools, where Ca(2+) is initially
released upon cell activation. Here, we present evidence that, during
stimulation, Ca(2+) transported into basolateral stores by SERCA pumps is
conveyed toward the luminal pools driven by proton gradients generated by
vacuolar H(+)-ATPases. This finding unveils a new aspect of the machinery of
Ca(2+) stores.
PMID- 10679326
TI - Role of the kinesin neck linker and catalytic core in microtubule-based motility.
AB - Kinesin motor proteins execute a variety of intracellular microtubule-based
transport functions [1]. Kinesin motor domains contain a catalytic core, which is
conserved throughout the kinesin superfamily, followed by a neck region, which is
conserved within subfamilies and has been implicated in controlling the direction
of motion along a microtubule [2] [3]. Here, we have used mutational analysis to
determine the functions of the catalytic core and the approximately 15 amino acid
'neck linker' (a sequence contained within the neck region) of human conventional
kinesin. Replacement of the neck linker with a designed random coil resulted in a
200-500-fold decrease in microtubule velocity, although basal and microtubule
stimulated ATPase rates were within threefold of wild-type levels. The catalytic
core of kinesin, without any additional kinesin sequence, displayed microtubule
stimulated ATPase activity, nucleotide-dependent microtubule binding, and very
slow plus-end-directed motor activity. On the basis of these results, we propose
that the catalytic core is sufficient for allosteric regulation of microtubule
binding and ATPase activity and that the kinesin neck linker functions as a
mechanical amplifier for motion. Given that the neck linker undergoes a
nucleotide-dependent conformational change [4], this region might act in an
analogous fashion to the myosin converter, which amplifies small conformational
changes in the myosin catalytic core [5,6].
PMID- 10679327
TI - Lif1p targets the DNA ligase Lig4p to sites of DNA double-strand breaks.
AB - DNA ligases catalyse the joining of DNA single- and double-strand breaks.
Saccharomyces cerevisiae Cdc9p is a homologue of mammalian DNA ligase I and is
required for DNA replication, recombination and single-strand break repair. The
other yeast ligase, Lig4p/Dnl4p, is a homologue of mammalian DNA ligase IV, and
functions in the non-homologous end-joining (NHEJ) pathway of DNA double-strand
break repair [1] [2] [3] [4]. Lig4p interacts with Lif1p, the yeast homologue of
the human ligase IV-associated protein, XRCC4 [5]. This interaction takes place
through the carboxy-terminal domain of Lig4p and is required for Lig4p stability.
We show that the carboxy-terminal interaction region of Lig4p is necessary for
NHEJ but, when fused to Cdc9p, is insufficient to confer NHEJ function to Cdc9p.
Also, Lif1p stimulates the in vitro catalytic activity of Lig4p in adenylation
and DNA ligation. Nevertheless, Lig4p is inactive in NHEJ in the absence of Lif1p
in vivo, even when Lig4p is stably expressed. We show that Lif1p binds DNA in
vitro and, through in vivo cross-linking and chromatin immuno precipitation
assays, demonstrate that it targets Lig4p to chromosomal DNA double-strand
breaks. Furthermore, this targeting requires another key NHEJ protein, Ku.
PMID- 10679328
TI - Discrete in vivo roles for the MutL homologs Mlh2p and Mlh3p in the removal of
frameshift intermediates in budding yeast.
AB - The DNA mismatch repair machinery is involved in the correction of a wide variety
of mutational intermediates. In bacterial cells, homodimers of the MutS protein
bind mismatches and MutL homodimers couple mismatch recognition to downstream
processing steps [1]. Eukaryotes possess multiple MutS and MutL homologs that
form discrete, heterodimeric complexes with specific mismatch recognition and
repair properties. In yeast, there are six MutS (Msh1-6p) and four MutL (Mlh1-3p
and Pms1p) family members [2] [3]. Heterodimers comprising Msh2p and Msh3p or
Msh2p and Msh6p recognize mismatches in nuclear DNA [4] [5] and the subsequent
processing steps most often involve a Mlh1p-Pms1P heterodimer [6] [7]. Mlh1p also
forms heterodimeric complexes with Mlh2p and Mlh3p [8], and a minor role for
Mlh3p in nuclear mismatch repair has been reported [9]. No mismatch repair
function has yet been assigned to the fourth yeast MutL homolog, Mlh2p, although
mlh2 mutants exhibit weak resistance to some DNA damaging agents [10]. We have
used two frameshift reversion assays to examine the roles of the yeast Mlh2 and
Mlh3 proteins in vivo. This analysis demonstrates, for the first time, that yeast
Mlh2p plays a role in the repair of mutational intermediates, and extends earlier
results implicating Mlh3p in mismatch repair.
PMID- 10679329
TI - Re-modelling of nuclear architecture in quiescent and senescent human
fibroblasts.
AB - Spatial organisation of the genome within the nucleus can play a role in
maintaining the expressed or silent state of some genes [1]. There are distinct
addresses for specific chromosomes, which have different functional
characteristics, within the nuclei of dividing populations of human cells [2].
Here, we demonstrate that this level of nuclear architecture is altered in cells
that have become either quiescent or senescent. Upon cell cycle exit, a gene-poor
human chromosome moves from a location at the nuclear periphery to a more
internal site in the nucleus, and changes its associations with nuclear
substructures. The chromosome moves back toward the edge of the nucleus at a
distinctive time after re-entry into the cell cycle. There is a 2-4 hour period
at the beginning of G1 when the spatial organisation of these human chromosomes
is established. Lastly, these experiments provide evidence that temporal control
of DNA replication can be independent of spatial chromosome organisation. We
conclude that the sub-nuclear organisation of chromosomes in quiescent or
senescent mammalian somatic cells is fundamentally different from that in
proliferating cells and that the spatial organisation of the genome is plastic.
PMID- 10679330
TI - Biology in pictures. Grow with the flow.
PMID- 10679331
TI - The yen for success.
PMID- 10679332
TI - Allergy.
PMID- 10679333
TI - Fevered headlines.
PMID- 10679334
TI - Muscular dystrophy.
PMID- 10679335
TI - Chemoinformatics - similarity and diversity in chemical libraries.
AB - Molecular similarity and molecular diversity techniques lie at the heart of
attempts to design structurally diverse combinatorial libraries for the
identification of novel bioactive compounds. Recent advances include the
development of new types of selection algorithm, the validation of such
algorithms, the use of filtering systems to screen out undesirable molecules
prior to the design of a library, and the integration of similarity and diversity
analysis with other methods for computer-aided molecular design.
PMID- 10679336
TI - Neutron scattering: good news for biotechnology.
AB - In its application to biological systems, neutron scattering is still an emerging
technology with a great deal of potential. A consequence of the native
interaction between neutrons and biological samples is that the hydrogen isotopes
(1)H and (2)H are most significant in dynamical and structural studies,
respectively.
PMID- 10679337
TI - Large-scale predictions of secretory proteins from mammalian genomic and EST
sequences.
AB - Machine learning techniques have improved predictions of secretory proteins from
protein, genomic and expressed sequence tag (EST) sequences. Artificial neural
networks, physical sequence analysis using high-performance optimization, and
hidden Markov models identify extremely variable signal peptides (the vehicles of
protein transport across the endoplasmic reticulum membrane), transmembrane
segments, and specific extracellular and intracellular domains as indicators of
possible roles in the intercellular and intracellular chemical signaling
pathways. The major role of peptide hormones, blood coagulation factors,
carcinogenesis agents, and other secretory proteins in orchestrating
multicellular life indicates pharmacological potential in the cure of major
diseases and numerous biotechnological applications.
PMID- 10679338
TI - Extraction of pharmacophore information from high-throughput screens.
AB - Two major advances have been made in the computational perception and utilization
of pharmacophores in compound libraries, both real and virtual. Firstly, a
hierarchical set of filtering calculations has emerged that can be used to
efficiently partition a library into a trial set of pharmacophores. This
sequential filtering permits large libraries to be efficiently processed, as well
as compounds judged as 'hits' to be analyzed in great detail. Secondly, new and
extended methods of QSAR (quantitative structure-activity relationship) analysis
have evolved to translate pharmacophore information into QSAR models that, in
turn, can be used as virtual high-throughput screens for activity profiling of a
library.
PMID- 10679339
TI - Microarray technology - enhanced versatility, persistent challenge.
AB - Microarray analysis of nucleic acid related phenomena on a genome-wide scale is
now a proven technology. New applications of the method are appearing rapidly and
problems unique to the handling and interpretation of the large data sets
produced by the technique are beginning to be addressed.
PMID- 10679340
TI - Visualization of data.
AB - Data visualization has developed in several directions: theoretical;
methodological; and in new application areas. Advances include the development of
a grammar of graphics, deeper understanding of human perception and implications
for graphical layout, and better approaches to visualizing multi-dimensional data
and large data sets. Gene expression is a notable new application area for
visualization of large data sets.
PMID- 10679341
TI - Finding function through structural genomics.
AB - The recent availability of whole-genome sequences and large numbers of protein
coding regions from high-throughput cDNA analysis has fundamentally changed
experimental biology. These efforts have provided huge databases of protein
sequences, many of which are of unknown function. Deciphering the functions of
these myriad proteins presents a major intellectual challenge.
PMID- 10679342
TI - Advances in surface plasmon resonance biosensor analysis.
AB - The number and diversity of surface plasmon resonance (SPR) biosensor
applications continue to increase. Evolutions in instrument and sensor chip
technology, experimental methodology, and data analysis are making it possible to
examine a wider variety of biomolecular interactions in greater mechanistic
detail. SPR biosensors are poised to make a significant impact in basic research
and pharmaceutical discovery.
PMID- 10679343
TI - Discovery and modeling of transcriptional regulatory regions.
AB - A complex network of regulatory controls governs the patterns of gene expression.
Enabled by the tools of molecular cloning, initial experimental queries into the
gene regulatory network elucidated a wide array of transcription factors and
their cognate binding sites from hundreds of genes. The recent fusion of genome
scale experimental tools, a more comprehensive gene catalog, and concomitant
advances in computational methodology, has extended the range of questions being
posed. The potential to further our understanding of the biochemical mechanisms
of transcriptional regulation and to accelerate the delineation of regulatory
control regions in the human genome is enormous.
PMID- 10679344
TI - Chemoinformatics - predicting the physicochemical properties of 'drug-like'
molecules.
AB - A few major advances have occurred in the area of physicochemical modeling of
organic compounds during the past several years, spurred on by changes in the
pharmaceutical industry. Recent advances include the ability to categorize and
screen the overall physicochemical properties of potential drug candidates based
entirely on their molecular structures and the ability to model the components
that contribute to the oral absorption characteristics of potential drug
candidates.
PMID- 10679345
TI - Structural energetics of protein folding and binding.
AB - Structural energetics is a method for calculating the energetics of protein
folding and binding reactions as a function of temperature. This approach allows
measured energetics to be interpreted with regards to the protein structure and
the prediction of energetics from known structures. Recent advances include
improvements in the parameterization of enthalpy, entropy and heat capacity terms
and new applications, especially with regards to understanding dynamic properties
of proteins and how these are affected by ligand binding.
PMID- 10679346
TI - Biotechnology match making: screening orphan ligands and receptors.
AB - To date there has been a considerable amount of interest and success in the
pharmaceutical industry in the discovery of drug targets and diagnostics via
genomic technologies, namely DNA sequencing, mutation/polymorphism detection and
expression monitoring of mRNA. As the ultimate targets for the majority of these
methods are actually proteins, more and more emphasis has been placed upon
protein-based methods in an effort to define the function of proteins discovered
by genomic technologies. One of the most challenging areas of drug target
discovery facing researchers today is the search for novel receptor-ligand pairs.
Database mining techniques in conjunction with other computational methods are
able to identify many novel sequences of putative receptors, but the ability to
similarly identify the receptor's natural ligand is not possible by these
methods. The past few years have seen an increase in methodology and
instrumentation focused on the ability to discover and characterize protein
protein interactions, as well as receptor-ligand pairs. Significant advances have
been made in the areas of instrumentation (biosensors and fluorescent plate
readers) as well as methodologies relating to phage/ribosome display and library
construction.
PMID- 10679347
TI - Riding the wave: structural and energetic principles of helical membrane
proteins.
AB - Genome sequencing efforts have revealed that perhaps as many as 20-40% of open
reading frames in complex organisms may encode proteins containing at least one
helical transmembrane segment. Contrasting with this approaching tidal wave of
helical membrane proteins is the fact that our understanding of the sequence
structure-function relationships for membrane proteins lags far behind that of
soluble proteins. This looming reality emphasizes the tremendous biochemical and
structural work that remains to be done on helical membrane proteins in order to
elucidate the structural and energetic principles that specify and stabilize
their folds, which define their functions. These facts are not lost on the
pharmaceutical industry, where successful therapeutics and major discovery
efforts are targeting membrane proteins.
PMID- 10679348
TI - Biopharmaceutical formulation.
AB - The rapid maturation of the field of biopharmaceutical formulation is the result
of the simultaneous development of a thermodynamic mechanism for protein-solvent
interaction and identification of natural chemicals employed by nature to
stabilize proteins in response to environmental stresses. In general, these
cosolvents are excluded from the protein surface. Proteins are maintained in
their native folded conformations by these cosolvents as a result of the highly
unfavorable interaction between cosolvents and peptide backbones, which would be
exposed to the cosolvent upon unfolding.
PMID- 10679349
TI - High-throughput and ultra-high-throughput screening: solution- and cell-based
approaches.
AB - The trend towards assay miniaturization for high-throughput and ultra-high
throughput screening continues to spur development of homogeneous, fluorescence
based assays in higher density, smaller volume microplate formats. Recently,
first-generation microfluidic devices have been designed for performing
continuous-flow biochemical and cell-based assays. These devices provide orders
of-magnitude reduction in reagent consumption, and offer the potential for
implementing high-throughput screening in formats that integrate up-front
compound handling with unique assay functionality.
PMID- 10679350
TI - Biological function made crystal clear - annotation of hypothetical proteins via
structural genomics.
AB - Many of the gene products of completely sequenced organisms are 'hypothetical' -
they cannot be related to any previously characterized proteins - and so are of
completely unknown function. Structural studies provide one means of obtaining
functional information in these cases. A 'structural genomics' project has been
initiated aimed at determining the structures of 50 hypothetical proteins from
Haemophilus influenzae to gain an understanding of their function. Each stage of
the project - target selection, protein production, crystallization, structure
determination, and structure analysis - makes use of recent advances to
streamline procedures. Early results from this and similar projects are
encouraging in that some level of functional understanding can be deduced from
experimentally solved structures.
PMID- 10679351
TI - gamma-tubulin complexes: binding to the centrosome, regulation and microtubule
nucleation.
AB - Microtubule assembly is initiated in vivo by gamma-tubulin complexes. Cytoplasmic
gamma-tubulin complexes are targeted to centrosomes or to other microtubule
organizing centers (MTOCs) via a set of so called gamma-tubulin complex binding
proteins (GTBPs) that probably interact with the conserved Spc97p/Spc98p protein
family of gamma-tubulin complexes. In other cell types, gamma-tubulin complexes
may initiate microtubule formation near chromosomes in a MTOC-independent manner.
Recently, major advances have been achieved through the finding that gamma
tubulin, Spc97p and Spc98p form a conserved core that is probably responsible for
microtubule nucleation, and by the discovery that a yeast GTBP is regulated in a
cell-cycle-dependent manner and in response to an external signal. Furthermore,
it was found that the small GTPase Ran in its GDP-bound state may promote spindle
assembly. In addition, an essential function of gamma-tubulin in basal body
duplication has been demonstrated in Paramecium.
PMID- 10679352
TI - Membrane trafficking, organelle transport, and the cytoskeleton.
AB - Cytoskeleton-associated motor proteins typically drive organelle movements in
eukaryotic cells in a manner that is tightly regulated, both spatially and
temporally. In the past year, a novel organelle transport mechanism utilizing
actin polymerization was described. Important advances were also made in the
assignment of functions to several new motors and in our understanding of how
motor proteins are regulated during organelle transport. In addition, insights
were gained into how and why organelles are transported cooperatively along the
microtubule and actin cytoskeletons, and into the importance of motor-mediated
transport in the organization of the cytoskeleton itself.
PMID- 10679354
TI - Microtubule dynamics and tubulin interacting proteins.
AB - Microtubule dynamics are crucial in generation of the mitotic spindle. During the
transition from interphase to mitosis, there is an increase in the frequency of
microtubule catastrophes. Recent work has identified two proteins, Op 18/stathmin
and XKCM1, which can promote microtubule catastrophes in vitro and in cells or
extracts. Although both of these proteins share the ability to bind tubulin
dimers, their mechanisms of action in destabilizing microtubules are distinct.
PMID- 10679353
TI - Parallel actin bundles and their multiple actin-bundling proteins.
AB - Parallel actin bundles are present in a diverse array of structures, where they
are critical determinants of cellular shape and physiology. In the past 18
months, new findings have solidified the concept that parallel actin bundles are
assembled in cells through the sequential action of multiple actin-bundling
proteins and have begun to shed light on the roles played by the individual actin
bundling proteins.
PMID- 10679355
TI - Kinesins and microtubules: their structures and motor mechanisms.
AB - Atomic resolution three-dimensional structures of two oppositely directed kinesin
motors - conventional kinesin and non-claret disjunctional (ncd) protein - are
now available in their functional dimeric form. A detailed model of the
microtubule has also been recently obtained by docking the 3.7 A structure of
tubulin into a 20 A map of the microtubule. Recent structural studies of kinesin
motors and their microtubule tracks are contributing to our current understanding
of kinesin motor mechanisms.
PMID- 10679356
TI - Cytokinesis without myosin II.
AB - The ability of substrate-anchored Dictyostelium cells to divide without myosin II
has opened the possibility of analysing the formation of cleavage furrows in the
absence of a contractile ring made of filamentous myosin and actin. Similar
possibilities exist in mutants of budding yeast and, less strictly, also in drug
treated mammalian cells. Myosin-II-independent activities in Dictyostelium
include the microtubule-induced programming of the cell surface into ruffling
areas and regions that are converted into a concave furrow, as well as the
translocation of cortexillins and cross-linked membrane proteins towards the
cleavage furrow. A centripetal flow of actin filaments followed by their
disassembly in the cleavage furrow is proposed to underlie the translocation.
PMID- 10679357
TI - Functional cooperation between the microtubule and actin cytoskeletons.
AB - In diverse cell types, microtubule (MT) and actin filament networks cooperate
functionally during a wide variety of processes, including vesicle and organelle
transport, cleavage furrow placement, directed cell migration, spindle rotation,
and nuclear migration. The mechanisms by which MTs and actin filaments cooperate
to mediate these different processes can be grouped into two broad categories:
coordinated MT- and actin-based transport to move vesicles, organelles, and cell
fate determinants; and targeting and capture of MT ends at cortical actin sites.
Over the past several years, a growing number of cellular factors that bridge
these cytoskeletal systems have been identified. These include 'hetero-motor'
complexes (physically associated myosin and kinesin), myosin-CLIP170 complexes,
formin homology (FH) proteins, dynein and the dynactin complex, Kar9p, coronin,
Kelch repeat-containing proteins, and ERM proteins.
PMID- 10679358
TI - Control of actin assembly and disassembly at filament ends.
AB - The most important discovery in the field is that the Arp2/3 complex nucleates
assembly of actin filaments with free barbed ends. Arp2/3 also binds the sides of
actin filaments to create a branched network. Arp2/3's nucleation activity is
stimulated by WASP family proteins, some of which mediate signaling from small G
proteins. Listeria movement caused by actin polymerization can be reconstituted
in vitro using purified proteins: Arp2/3 complex, capping protein, actin
depolymerizing factor/cofilin, and actin. actin depolymerizing factor/cofilin
increases the rate at which actin subunits leave pointed ends, and capping
protein caps barbed ends.
PMID- 10679359
TI - Functions of unconventional myosins.
AB - To date, fourteen classes of unconventional myosins have been identified. Recent
reports have implicated a number of these myosins in organelle transport, and in
the formation, maintenance and/or dynamics of actin-rich structures involved in a
variety of cellular processes including endocytosis, cell migration, and sensory
transduction. Characterizations of organelle dynamics in pigment cells and
neurons have further defined the contributions made by unconventional myosins and
microtubule motors to the transport and distribution of organelles. Several
studies have provided evidence of complexes through which cooperative organelle
transport may be coordinated. Finally, the myosin superfamily has been shown to
contain at least one processive motor and one backwards motor.
PMID- 10679360
TI - Intermediate filaments and their associates: multi-talented structural elements
specifying cytoarchitecture and cytodynamics.
AB - The assembly of intermediate filament (IF) arrays involves the recruitment of a
complex set of cell-type-specific IF-associated proteins. Some of them are
integral membrane proteins, others act as crosslinking proteins with vectorial
binding activities, and yet others comprise motor proteins. In vivo IFs appear to
be predominantly heteropolymers, although in vitro several IF proteins (e.g.
vimentin, desmin, neurofilament (NF)-L and the nuclear lamins) do self-assemble
into IF-like polymers. In contrast, NF-M, NF-H, nestin, synemin and paranemin,
all bona fide IF proteins, are unable to self-assemble into IFs either in vitro
or in vivo. The individual IF proteins of this large multigene family are
chemically heterogeneous, exhibiting different assembly kinetics and yielding
discrete types of filaments. The unique physical properties and interaction
capabilities of these distinct IF molecular building blocks, in combination with
accessory proteins, mediate the generation of a highly dynamic and
interconnected, cell-type-specific cytoarchitecture.
PMID- 10679361
TI - Focal adhesions - the cytoskeletal connection.
AB - Cellular contacts with the extracellular matrix are regulated by the Rho family
of GTPases through their effects on both the actin and the microtubule
cytoarchitecture. Recent genetic, biochemical and structural data have
highlighted the role played by a subset of actin-binding proteins in coupling
integrins to cytoskeletal actin and in assembling signalling complexes that are
important for cell motility and cell proliferation.
PMID- 10679362
TI - How WASP-family proteins and the Arp2/3 complex convert intracellular signals
into cytoskeletal structures.
AB - In most cells, the structure of the actin cytoskeleton is regulated by Rho-family
G proteins. Recent work has outlined a highly conserved signaling pathway from G
protein activation to actin assembly. The key downstream components are WASP
family proteins - adaptor molecules that bind multiple signaling and cytoskeletal
proteins - and the Arp2/3 complex - a multi-functional protein complex that
nucleates and crosslinks actin filaments.
PMID- 10679363
TI - Actomyosin: law and order in motility.
AB - The crystal structures of smooth muscle and scallop striated muscle myosin have
both been completed in the past 18 months. Structural studies of unconventional
myosins, in particular the stunning discovery that myosin VI moves backwards on
actin, are starting to have deep impact on the field and have induced new ways of
thinking about actin-based motility. Sophisticated genetic, biochemical and
biophysical studies were used to test and refine hypotheses of the molecular
mechanism of motility that were developed in the past. Although all these studies
confirmed some aspects of these hypotheses, they also raised many new unresolved
questions. Much of the evidence points to the importance of the actin-myosin
binding process and an associated disorder-to-order transition.
PMID- 10679364
TI - How centrioles work: lessons from green yeast.
AB - Centrioles are the organizing centers around which centrosomes assemble. Despite
a century of study, the molecular details of centriole function and assembly
remain largely unknown. Recent work has exploited the unique advantages of
unicellular algae to reveal proteins that play central roles in centriole
biology.
PMID- 10679365
TI - Single molecule analysis of the actomyosin motor.
AB - Progress in imaging techniques and nano-manipulation of single molecules has been
remarkable. These techniques have allowed the accurate determination of myosin
head-induced displacements and of how the mechanical cycles of the actomyosin
motor are coupled to ATP hydrolysis. This has been achieved by measuring
mechanical and chemical events of actomyosin directly at the single molecule
level. Recent studies have made detailed measurements of myosin step size and
mechanochemical coupling. The results of these studies suggest a new model for
the mechanism of motion underlying actomyosin motors, which differs from the
currently accepted lever-arm swinging model.
PMID- 10679366
TI - Actin machinery: pushing the envelope.
AB - The reconstitution of microbial rocketing motility in vitro with purified
proteins has recently established definitively that no myosin motor is required
for protrusion. Instead, actin polymerization, in conjunction with a small number
of proteins, is sufficient. A dendritic pattern of nucleation controlled by the
Arp2/3 complex provides an efficient pushing force for lamellipodial motility.
PMID- 10679367
TI - Oxynitrilases for asymmetric C-C bond formation.
AB - Oxynitrilases for the preparation of (R)- or (S)-cyanohydrins are now readily
available. The research efforts of a number of groups have established these
enzymes as catalysts with significant potential for application to asymmetric
synthesis. Advances made in molecular cloning and genetics have delivered
information on the oxynitrilase mechanism of action and sufficient quantities of
enzyme to satisfy industrial requirements.
PMID- 10679368
TI - Elucidation of protein-protein interactions using chemical cross-linking or label
transfer techniques.
AB - Understanding the architectures of multiprotein complexes is a central problem in
biology. Of the many chemical methods available, label transfer and cross-linking
are becoming more popular. Recently, label transfer has been applied to very
large protein complexes with great success, and new oxidative methods for protein
cross-linking have been developed that are fast and highly efficient. Advances in
these techniques should increase the understanding of biological structures and
mechanisms.
PMID- 10679369
TI - Enzyme-catalyzed synthesis of carbohydrates.
AB - Several new enzymes of utility in the synthesis of carbohydrates have been
reported during the past year. Additionally, the utility of several well studied
enzymes has been expanded. Pyruvate aldolases, aldolase abzymes and both wild
type and mutated glycosidases have found increasing acceptance in the community.
Preliminary reports suggest that thermophilic enzymes may possess significant
advantages compared to their mesophilic counterparts for carbohydrate synthesis.
PMID- 10679370
TI - Nitrile hydrolases.
AB - A number of nitrile-related enzymes have been screened over the past year for use
in synthetic applications. There have also been significant advances in our
understanding of the structures and modes of regulation of metal-containing
nitrile hydratases. Enzyme structural characterization has provided new insights
into how the molecular structure determines the enzyme function and how an enzyme
can be endowed with new properties. This information has important implications
for potential future applications other than the present industrial production of
acrylamide and nicotinamide.
PMID- 10679371
TI - Covalent modification as a strategy to block protein-protein interactions with
small-molecule drugs.
AB - It is generally difficult to block protein-protein interactions with small
molecule drugs. A novel pharmaceutical development strategy to block protein
interactions is emerging: targeted covalent modification to sterically block
interactions. By this approach, compounds first interact non-covalently with a
specific target protein. This interaction juxtaposes a weakly reactive group of
the drug with a target amino acid sidechain, which then react by virtue of their
high local concentration.
PMID- 10679372
TI - Design of novel sequence-specific DNA-binding proteins.
AB - The design and selection of DNA-binding proteins or individual domains capable of
novel sequence recognition continues to make great strides. Recent studies have
also highlighted the role of the non-DNA-contacting portions of the protein and
the optimal assembly of the domains. For the first time, it appears that it is
possible to produce proteins capable of targeting any gene with an 18 base pair
recognition domain. A variety of applications are being explored, such as
targeted transcriptional regulation, recombination and viral integration. These
proteins will probably find diverse applications in gene therapy, functional
genomics, and agriculture.
PMID- 10679373
TI - Directed evolution of enantioselective enzymes for organic chemistry.
AB - The production of enantiopure compounds is of steadily increasing importance to
the chemical and biotechnological industries. In principal, the application of
directed evolution in combination with newly developed screening methods enables
the generation of enzymes with improved enantioselectivity. The first and most
advanced example relates to a bacterial lipase from Pseudomonas aeruginosa. This
enzyme was evolved towards a model substrate to yield in a lipase mutant showing
> 90% enantiomeric excess as compared to 2% for the wild-type lipase. The
creation of enantioselective enzymes by directed evolution will become an
important technology in the near future.
PMID- 10679374
TI - Small-molecule inhibitors of the cell cycle.
AB - The cell cycle remains an attractive target for the development of small-molecule
inhibitors for use as both novel chemotherapeutics and research probes. Given the
importance of cytoskeletal dynamics and cyclin-dependent kinases for cell-cycle
progression, much interest has focused on the identification of anti-mitotic
agents and kinase inhibitors. However recent advances in cell-based screening
technologies and an increased interest in inhibitors with greater specificity are
beginning to influence the search for novel cell-cycle inhibitors.
PMID- 10679375
TI - Role of linkers in communication between protein modules.
AB - Multidomain proteins are common in a variety of cellular processes. Their domains
are interconnected through short stretches of amino acid residues referred to as
linkers. Recent studies on many systems have provided compelling evidence that
linkers are more than simple covalent connectors. They also perform the important
task of establishing communication between the different functional modules that
exist within such proteins.
PMID- 10679376
TI - Modifying ligand specificity of gene regulatory proteins.
AB - Nuclear receptors contain a conserved hydrophobic ligand binding pocket that is
particularly amenable to structure-based protein engineering. Thus, site-directed
mutagenesis of the ligand binding pocket has resulted in the creation of nuclear
receptors with novel ligand specificities. Such proteins are now being used to
control gene expression in vivo in a ligand-dependent manner.
PMID- 10679377
TI - Combinatorial protein reagents to manipulate protein function.
AB - The design and use of combinatorial protein libraries has become a fast moving
field in molecular biology. Different experimental systems supporting various
selection schemes are now available. The latest breakthroughs include
evolutionary experiments to improve existing binding surfaces, selections of
homodimerizing peptides, the use of peptide aptamers to disrupt protein
interactions inside living cells, and functional selections of aptamers to probe
regulatory networks.
PMID- 10679378
TI - Engineering biosynthetic pathways: new routes to chiral amino acids.
AB - The engineering of microbial biosynthetic pathways is advancing rapidly because
of new molecular genetic approaches, sophisticated analysis of metabolic flux and
the rapid sequencing of diverse bacterial genomes. The classical methods of
mutagenesis/selection, originally applied in the development of amino-acid-over
producing bacteria are now being complemented by an increasingly rational
strategy.
PMID- 10679379
TI - Biocatalysis in low-water media: understanding effects of reaction conditions.
AB - The key role played by counter-ions with enzymes in low-water systems has become
better appreciated with, for example, large effects on enantioselectivity. In low
dielectric media, counter-ions will associate strongly with charges in the
protein or its substrates. Studies of temperature dependence have shown that hard
to-model entropies have a significant effect on behaviour, including
enantioselectivity. Evidence has been presented that the supramolecular
organisation of enzyme molecules can have important effects on behaviour, for
example collapse of microstructure in cross-linked crystals.
PMID- 10679380
TI - New approaches for cell-specific targeting: identification of cell-selective
peptides from combinatorial libraries.
AB - Peptides that recognize specific cell types promise to be valuable tools both in
research and clinical applications. Cell-specific peptides can be useful as drug
delivery vehicles, diagnostic agents, affinity reagents for cell purification,
gene therapy delivery agents, and research tools to probe the nature of a cell's
surface. Recently, cell-specific targeting-peptides have been identified by phage
display selections against purified cell-surface markers, whole cells in tissue
culture, and even tissues within live animals. These methods for identifying cell
targeting peptides will certainly increase the tools available to the scientist
for cell-specific targeting.
PMID- 10679381
TI - Observation of unstable species in enzyme-catalyzed transformations using protein
crystallography.
AB - Recent advances in rapid X-ray diffraction data collection methods,
cryocrystallography, and other techniques have made it possible to visualize
short-lived species in enzyme-catalyzed reactions directly at atomic resolution
for a significant number of crystalline enzymes. The wide range of reaction
types, intermediate lifetimes, and crystal characteristics means that different
methods must be employed in each case, but there are enough examples now of
successful structure determinations of normally unstable species to suggest
guidelines for future investigations.
PMID- 10679382
TI - Molecular modeling and biocatalysis: explanations, predictions, limitations, and
opportunities.
AB - Rapid advances in structural biology have revealed the three-dimensional
structures of many biocatalysts. Molecular modeling is the tool that links these
structures with experimental observations. As a qualitative tool, current
modeling methods are extremely useful. They can explain, on a molecular level,
unusual features of reactions. They can predict how to increase the selectivity
either by substrate modification or by site-directed mutagenesis. Quantitative
predictions, for example the degree of enantioselectivity, are still not
reliable, however. Modeling is limited also by the availability of three
dimensional structures. Most current modeling involves hydrolases, especially
proteases and lipases, but structures for other types of enzymes are starting to
appear.
PMID- 10679383
TI - The ARF/p53 pathway.
AB - The ARF tumor suppressor connects pathways regulated by the retinoblastoma
protein and p53. ARF inactivation reduces p53-dependent apoptosis induced by
oncogenic signals. Nucleolar relocalization of Mdm2 by ARF connotes a novel
mechanism for preventing p53 turnover and provides a framework for understanding
how stress signals cooperate to regulate p53 function.
PMID- 10679384
TI - RecQ family helicases: roles in cancer and aging.
AB - The RecQ family of DNA helicases includes at least three members in humans that
are defective in genetic disorders associated with cancer predisposition and/or
premature aging. Recent studies have shed light on the roles of RecQ helicases in
suppressing 'promiscuous' genetic recombination and in ensuring accurate
chromosome segregation. In particular, the biochemical properties of several
family members have been characterised and functional interactions with other
nuclear proteins have been defined.
PMID- 10679385
TI - Complexity in the spindle checkpoint.
AB - Cell viability requires accurate chromosome segregation at mitosis. The spindle
checkpoint ensures that anaphase is not attempted until the sister chromatids of
each chromosome are attached to spindle microtubules from opposite poles. The
checkpoint mechanism involves a signal transduction cascade that is more complex
than was originally envisioned.
PMID- 10679386
TI - Tumor suppressor genes.
AB - Although tumor suppressor genes continue to be discovered, the most recent
advances have been made in attributing new and exciting functions to existing
ones - such as the apparent role of VHL as a regulator of proteolysis. Great
insights have also come from piecing genes together into pathways and networks.
For instance the discovery that cyclin D1 is regulated by beta-catenin/Tcf-4
allows us to tie the APC pathway to the RB pathway and cell cycle control.
Similarly, tumor suppressor genes have been fitted together with oncogenes into
the various pathways that regulate apoptosis such that tumor suppressor function
is now attributed to some of the basic components of the apoptotic machinery,
such as caspases and Apaf-1. The great pace at which mouse models of
tumorigenesis continue to advance our knowledge of tumor suppressor gene function
has led us to look anew at the role of genes such as TCF-1 and SMAD-3 in human
cancer. Finally, the realisation that different growth regulatory pathways give
rise to generic signals suggests that future work may lie in integrating the
signals from different pathways and in understanding the importance of protein
levels to cellular function.
PMID- 10679387
TI - The genetic control of organ growth: insights from Drosophila.
AB - The genetic control of growth ensures that animals grow to reproducible sizes and
that tumourous growth is rare. This year, the regulation of organ growth has been
studied extensively in Drosophila imaginal discs, and a signalling pathway that
regulates organ growth and size has been identified. Furthermore, the role of
Drosophila homologues to human tumour suppressor genes and oncogenes in imaginal
disc growth has been investigated.
PMID- 10679388
TI - Extrinsic regulators of epithelial tumor progression: metalloproteinases.
AB - Extracellular metal-dependent proteinases regulate cell behavior by remodeling
stromal and cell surface proteins, thereby influencing cell recruitment, cell
shape, motility, proliferation, survival, genomic (in)stability, and
differentiation. In recent years, the importance of proteinase-induced signaling
has been underscored by evidence that altered regulation of cell-extracellular
matrix and cell-cell interactions by proteinases can contribute, in a causal
manner, to neoplastic progression.
PMID- 10679389
TI - Controlling the end of the cell cycle.
AB - The past year has seen significant advances in our understanding of how the
events which occur at the end of mitosis, such as cytokinesis and the
inactivation of mitotic cyclin dependent kinases are triggered, and also how they
are prevented from occurring prematurely or inappropriately. This control is
achieved through a combination of temporally ordered proteolytic events and
changes in the subcellular localisation of proteins. These studies have also
revealed that the nucleolus and spindle pole bodies play a key role in this
regulation.
PMID- 10679390
TI - Viral-encoded cyclins.
AB - D-type cyclin homologs have been found in the genomes of herpesviruses associated
with neoplasias. They appear to exploit features of G(1) cyclins but extend their
properties to allow for deregulation of the cell cycle. Advances in the study of
the molecular basis for these novel features as well as the potential role of
viral cyclins in tumorigenesis are addressed.
PMID- 10679391
TI - Action of Myc in vivo - proliferation and apoptosis.
AB - The protein products of many dominant oncogenes are capable of inducing both cell
proliferation and apoptosis. Recent experiments employing transgenic mice that
express an ectopically regulatable myc gene or protein have begun to elucidate
the role of the balance between proliferation and apoptosis in Myc-induced
carcinogenesis. An outstanding feature of these experiments is the demonstration
that the balance between oncogene-induced proliferation and apoptosis in a given
tissue can be a critical determinant in the initiation and maintenance of the
tumor.
PMID- 10679392
TI - A critical role for telomeres in suppressing and facilitating carcinogenesis.
AB - Progressive telomere shortening occurs with the division of primary human cells
and activates tumor suppressor pathways, triggering senescence and inhibiting
tumorigenesis. Loss of p53 function, however, allows continued cell division
despite increasing telomere dysfunction and entry into telomere crisis. Recent
data suggest that the severe chromosomal instability of telomere crisis promotes
secondary genetic changes that facilitate carcinogenesis. Reactivation of
telomerase stabilizes telomere ends and allows continued tumor growth.
PMID- 10679393
TI - Cloak and dagger in the avoidance of immune surveillance.
AB - CD95 and CD95-ligand (CD95L) are physiological mediators of apoptosis required
for the control of cell numbers in the human immune system. Discoveries in CD95
dependent mechanisms of immune evasion by tumours suggest regulation by oncogene
expression. Clonal contraction of lymphocytes by a CD95/CD95L-independent
mechanism has been reported and new evidence supports a role for CD95-dependent
peripheral lymphocyte deletion by non-lymphoid tissue. Additionally, factors
affecting the pro- and anti-inflammatory effects of CD95L point to a balance of
cytokines and growth factors.
PMID- 10679394
TI - Proteolysis and the cell cycle: with this RING I do thee destroy.
AB - The ubiquitin system drives the cell division cycle by the timely destruction of
numerous regulatory proteins. Remarkably, the two main activities that catalyze
substrate ubiquitination in the cell cycle, the Skp1-Cdc53/cullin-F-box protein
(SCF) complexes and the anaphase-promoting complex/cyclosome (APC/C), define a
new superfamily of E3 ubiquitin ligases, all based on related cullin and RING-H2
finger protein subunits. The circuits that interconnect the SCF, APC/C and cyclin
dependent kinase activities form a master oscillator that coordinates the
replication and segregation of the genome.
PMID- 10679395
TI - Sensing and responding to DNA damage.
AB - DNA damage or stalled DNA replication can activate specific signal transduction
pathways, termed checkpoints. Checkpoint activation can result in increased
repair, induction of a transcriptional programme and inhibition of cell-cycle
progression. Recent results have suggested possible mechanisms for the detection
of specific DNA structures, provided further information on the organisation of
the signal transduction cascade and demonstrated involvement of the checkpoint
pathway in DNA repair.
PMID- 10679396
TI - Cell-cycle checkpoints that ensure coordination between nuclear and cytoplasmic
events in Saccharomyces cerevisiae.
AB - Cytoskeletal organization is crucial for several aspects of cell-cycle
progression but cytoskeletal elements are quite sensitive to environmental
perturbations. Two novel checkpoint controls monitor the function of the actin
and microtubule systems in budding yeast and operate to delay cell-cycle
progression in response to cytoskeletal perturbations. In cells whose actin
cytoskeleton has been perturbed, bud formation is frequently delayed and the
morphogenesis checkpoint introduces a compensatory delay of nuclear division
until a bud has been formed. In cells whose microtubule cytoskeleton has been
perturbed, anaphase spindle elongation often occurs entirely within the mother
cell, and the post-anaphase nuclear migration checkpoint introduces a
compensatory delay of cytokinesis until one pole of the anaphase nucleus enters
the bud. Recent studies indicate that regulators of entry into mitosis are
localized to the daughter side of the mother-bud neck whereas regulators of exit
from mitosis are localized to the spindle pole bodies. Thus, specific cell-cycle
regulators are well-placed to monitor whether a cell has formed a bud and whether
a daughter nucleus has been delivered accurately to the bud following mitosis.
PMID- 10679397
TI - Integration of positive and negative growth signals during ras pathway activation
in vivo.
AB - Expression of RAS proteins can have either positive or negative effects on cell
growth, differentiation and death. New technologies are being developed for the
generation of animal models to address the questions of where, when and how much
Ras is expressed during tumorigenesis, and how these disparate signals are
integrated during multistage carcinogenesis.
PMID- 10679398
TI - The role of IL-18 in innate immunity.
AB - IL-18 - a novel cytokine with potent IFN-gamma-inducing activities - plays an
important role in the Th1-mediated immune response in collaboration with IL-12.
IL-18 is a member of the IL-1 family. The IL-18 receptor system and its signal
transduction pathway are analogous to those of the IL-1 receptor. Mice deficient
in IL-18 have demonstrated its critical role in natural killer cell activity and
in vivo Th1 response.
PMID- 10679399
TI - NF-kappaB and the innate immune response.
AB - In the innate immune reaction, microbial pathogens activate phylogenetically
conserved cellular signal transduction pathways that regulate the ubiquitous
nuclear factor-kappaB (NFkappaB). NF-kappaB has pleiotropic functions in
immunity; however, it is also critical for development and cellular survival.
Many aspects of how the different pathways utilize a common kinase complex that
ultimately activates NF-kappaB have been clarified by gene inactivation and
biochemical analysis.
PMID- 10679400
TI - CD14-dependent clearance of apoptotic cells: relevance to the immune system.
AB - Until very recently, the function of CD14 was thought to be limited to innate
immune responses to bacterial and other microbial structures. It is now known
that macrophage CD14 serves an additional unexpected function, namely as a
receptor involved in the recognition and phagocytosis of cells undergoing
apoptosis. In stark contrast to its role in eliciting pro-inflammatory responses
following binding of microbial ligands, macrophage CD14 mediates clearance of
apoptotic cells without inciting inflammation. Increasing interest in the
profoundly important final stage of apoptosis - the engulfment process - together
with significant advances in knowledge of the immunological consequences of
apoptotic-cell clearance and of the means by which signal transduction may be
achieved following CD14-ligand binding have begun to produce a clearer picture of
the role of CD14 in the immune system.
PMID- 10679401
TI - Antigen arrays in T cell immunology.
AB - The screening of compound arrays in in vitro bioassays has developed into a
powerful tool for the identification of biologically active substances. In the
past decade, this technology has increasingly been applied to immunology. As the
specificity of the immune system is determined by antigen detection via receptors
on B and T cells, targeting the specificity of these immune receptors with random
arrays is unique in its ability to generate general and quantitative information
on cellular (cross-)reactivity. Synthetic array studies have been useful for
identification of epitopes and antigens from databases by defining recognition
patterns, isolation of synthetic peptides capable of modulating T cell
responsiveness, characterisation of TCR promiscuity, and identification of
functionally cross-reacting peptides that are potentially involved in molecular
mimicry.
PMID- 10679402
TI - Accessory molecules for MHC class II peptide loading.
AB - Accessory molecules, such as HLA-DM and invariant chain, modulate the ligands
bound to MHC class II molecules in antigen-presenting cells. Recent
investigations, including gene targeting experiments, have shed light on the
functions of these molecules, their mechanisms of action, interactions with class
II molecules, and the relationships with associated molecules such as
tetraspanins and HLA-DO.
PMID- 10679403
TI - Human complement regulators: a major target for pathogenic microorganisms.
AB - The C3 convertases of the human complement system are controlled by fluid-phase
and membrane proteins in the RCA (regulators of complement activation) family.
Accumulated data show that many pathogenic microorganisms interact with these
complement regulators. Recent advances in this field include determination of the
crystal structure of the binding domains in the measles virus receptor CD46 and
identification of a CD46 transgenic mouse line that is sensitive to measles
virus. Moreover, recent findings support the hypothesis that pathogenic bacteria
binding fluid-phase RCA proteins exploit these proteins to escape complement
attack. These studies provide novel insight into the interplay between pathogens
and the innate immune system and may have implications for the plans to use
animals expressing an RCA protein for xenotransplantation.
PMID- 10679404
TI - Reactive oxygen and reactive nitrogen intermediates in innate and specific
immunity.
AB - Nitric oxide, nitric oxide derivatives and reactive oxygen intermediates are
toxic molecules of the immune system which contribute to the control of microbial
pathogens and tumors. There is recent evidence for additional functions of these
oxygen metabolites in innate and adaptive immunity; these functions include the
modulation of the cytokine response of lymphocytes and the regulation of immune
cell apoptosis, as well as immunodeviating effects. Components of several signal
transduction pathways have been identified as intracellular targets for reactive
nitrogen and oxygen intermediates.
PMID- 10679405
TI - Rational antigen modification as a strategy to upregulate or downregulate antigen
recognition.
AB - Recent and rapid advances in our understanding of the cellular and molecular
mechanisms of antigen recognition by CD8(+) and CD4(+) T lymphocytes have led to
the birth of possibilities for site-directed, rational modification of cognate
antigenic determinants. This immunologic concept has vast biomedical implications
for regulation of host immunity against the pathogenesis of diverse disease
processes. The upregulation of antigen-specific T-cell responses by 'agonistic'
peptides would be most desirable in response to invasive pathogenic challenges,
such as infectious and neoplastic disease, while the downregulation of antigen
specific T-cell responses by 'antagonistic' peptides would be most efficacious
during inappropriate pathologic consequences, such as autoimmunity. The capacity
to experimentally manipulate intrinsic properties of cognate peptide ligands to
appropriately alter the nature, course and potency of cellular immune
interactions has important potential in both preventive and therapeutic clinical
paradigms.
PMID- 10679406
TI - The role of CpG motifs in innate immunity.
AB - Pattern recognition receptors of the innate immune system are able to distinguish
certain prokaryotic DNAs from vertebrate DNAs by detecting unmethylated CpG
dinucleotides in particular base contexts ('CpG motifs'). Recent studies have
begun to define the molecular mechanisms of actions of CpG motifs and have
demonstrated their stimulatory effects on leukocytes from humans and vertebrates
other than mice. Oligodeoxynucleotides containing CpG motifs are highly effective
Th1-like vaccine adjuvants through multiple routes of immunization and show
promise as immunotherapeutic agents for cancer and allergic diseases.
PMID- 10679407
TI - Toll signaling pathways in the innate immune response.
AB - The Toll signaling pathway, which is required for the establishment of the dorsal
ventral axis in Drosophila embryos, plays an important role in the response of
larval and adult Drosophila to microbial infections. Recent genetic evidence has
shown that a mammalian Toll-like receptor, mouse Tlr4, is the signal transducing
receptor activated by bacterial lipopolysaccharide. Thus, Toll-like receptors
appear to detect a variety of microbial components and to trigger a defensive
reaction in both Drosophila and mammals. Genetic data from both Drosophila and
mice have defined components required for activation of Toll-like receptors and
for the downstream pathways activated by the Toll-like receptors.
PMID- 10679408
TI - The control of T cell responses by dendritic cell subsets.
AB - Dendritic cells are known as the most efficient antigen-presenting cell type to
activate naive T cells; however, they are able to do more than just efficiently
present antigen to T cells. They are key modulators of the immune response that
can influence Th cell differentiation by preferentially inducing Th type 1 or 2
cell responses, and the differential polarisation of CD4(+) T cells appears to be
mediated by discrete dendritic cell subsets.
PMID- 10679409
TI - Cathepsins and compartmentalization in antigen presentation.
AB - Intracellular trafficking and cell surface expression of MHC class II molecules
is a tightly regulated process and is to a large extent, determined by the fate
of the class II chaperone, the invariant chain. Inhibition of endosomal proteases
critical to invariant chain proteolysis reveals marked shunting of class II
complexes to lysosomal compartments. Regulation of endosomal protease activity by
expression of cystatin C directs class II cell surface expression during
maturation of dendritic cells. These studies highlight the taut interactions
between class-II-invariant-chain complexes and endosomal proteases during MHC
class II maturation.
PMID- 10679410
TI - Identification of HLA-class-II-restricted epitopes of autoantigens in transgenic
mice.
AB - The past year has seen a spate of research in the use of HLA transgenic mice in
the identification of self antigens associated with autoimmunity. Dominant T cell
determinants - and, in a few cases, B cell determinants - have been characterized
in the context of disease-predisposing HLA DR and DQ genes for at least three
prominent and devastating autoimmune diseases: rheumatoid arthritis, multiple
sclerosis and insulin-dependent diabetes mellitus.
PMID- 10679411
TI - Tlr4: central component of the sole mammalian LPS sensor.
AB - Mutations of the mouse Lps locus abolish responses to lipopolysaccharide (LPS).
Positional cloning work has revealed that Lps encodes the Toll-like receptor 4
(Tlr4), which functions as the transmembrane component of the LPS receptor
complex, an unduplicated pathway for the detection of endotoxin. The structurally
related protein Tlr2 makes no contribution to LPS signal transduction.
PMID- 10679412
TI - From synapses to immunological memory: the role of sustained T cell stimulation.
AB - T cell activation is a sustained process driven by antigen and cytokines, which
results in the generation of large numbers of effector and memory cells. Recent
experiments from different fields have shed light on the mechanisms that maintain
the signaling process at the level of a single synapse between a T cell and an
antigen-presenting cell, as well as at the level of a secondary lymphoid organ,
in the course of the immune response. These findings explain the unique capacity
of the immune system to discriminate between antigens from infectious and
noninfectious agents.
PMID- 10679413
TI - Cellular routes of invasion by enteropathogens.
AB - The cellular pathways of infection utilized by pathogenic enteric bacteria have
important implications for their clinical manifestations. Yersinia reaches
Peyer's patches via M cells and uses plasmid-encoded factors to resist phagocytic
cells. Shigella also translocates via M cells and incapacitates phagocytes, but
subsequently re-enters the epithelium basolaterally to elicit an acute
inflammatory response. Salmonella has recently been shown to both colonize
Peyer's patches via M cells and independently disseminate to extraintestinal
sites via CD18-expressing phagocytes. M cell-mediated entry can lead to
gastroenteritis and mucosal antibody production, while systemic dissemination can
result in septicemia and elicitation of systemic immune responses.
PMID- 10679414
TI - Novel approaches to monitor bacterial gene expression in infected tissue and
host.
AB - Elucidating the complex and dynamic host-microbe interactions during infection
requires, among other things, detailed knowledge of microbial gene expression in
vivo. Recently, advances in fluorescence and bioluminescence detection
techniques, as well as recombinase-based in vivo expression technology, have
rendered monitoring virulence gene expression in vivo a feasible task. These
techniques have been adapted by several laboratories to study the spatial and
temporal patterns of virulence gene expression by organisms such as Salmonella
typhimurium, Listeria monocytogenes, Yersinia entercolitica and Vibrio cholerae
during infection of tissue culture or animal models of infection.
PMID- 10679415
TI - Caenorhabditis elegans: a model genetic host to study Pseudomonas aeruginosa
pathogenesis.
AB - In the past year, a Caenorhabditis elegans-Pseudomonas aeruginosa pathogenesis
model has been developed to facilitate the systematic dissection of both host and
pathogen genes involved in pathogenic interactions. Analysis of the P. aeruginosa
C. elegans interaction should shed light on the larger question of how organisms
interact at the molecular level in antagonistic relationships.
PMID- 10679416
TI - Analyzing the molecular foundations of commensalism in the mouse intestine.
AB - We maintain complex societies of nonpathogenic microbes on our mucosal surfaces.
Although the stability of this flora is important for human health, very little
is known about how its constituents communicate with us to forge stable and
mutually advantageous relationships. The vast majority of these indigenous
microbes reside in the intestine. Recent studies of a gut commensal, Bacteroides
thetaiotaomicron, has revealed a novel signaling pathway that allows the microbe
and host to actively collaborate to produce a nutrient foundation that can be
used by this bacterium. This pathway illustrates the type of dynamic molecular
interactions that help define commensal relationships.
PMID- 10679417
TI - Reactive nitrogen intermediates and the pathogenesis of Salmonella and
mycobacteria.
AB - Over the past decade, reactive nitrogen intermediates joined reactive oxygen
intermediates as a biochemically parallel and functionally non-redundant pathway
for mammalian host resistance to many microbial pathogens. The past year has
brought a new appreciation that these two pathways are partially redundant, such
that each can compensate in part for the absence of the other. In combination,
their importance to defense of the murine host is greater than previously
appreciated. In addition to direct microbicidal actions, reactive nitrogen
intermediates have immunoregulatory effects relevant to the control of infection.
Genes have been characterized in Mycobacterium tuberculosis and Salmonella
typhimurium that may regulate the ability of pathogens to resist reactive
nitrogen and oxygen intermediates produced by activated macrophages.
PMID- 10679418
TI - Genetic susceptibility to intracellular infections: Nramp1, macrophage function
and divalent cations transport.
AB - Nramp1 is one of the few host resistance genes that have been characterized at
the molecular level. Nramp1 is an integral membrane protein expressed in the
lysosomal compartment of macrophages and is recruited to the membrane of
bacterial phagosomes where it affects intracellular microbial replication. Nramp1
is part of a very large gene family conserved from bacteria and man that codes
for transporters of divalent cations transporters. We propose that Nramp1 affects
the intraphagosomal microbial replication by modulating divalent cations content
in this organelle. Both mammalian and bacterial transporters may compete for the
same substrate in the phagosomal space.
PMID- 10679419
TI - Bacterial pili: molecular mechanisms of pathogenesis.
AB - Gram-negative bacteria produce a diverse array of pili that mediate microbe
microbe and host-pathogen interactions important in the development of disease.
The structural and functional characterization of these organelles, particularly
their role in triggering signals in both the bacterium and the host upon
attachment, has begun to reveal the molecular mechanisms of bacterial diseases.
PMID- 10679420
TI - Bacterial replication in the host cell cytosol.
AB - Intracellular bacteria in mammalian host cells can either live in a membrane
bound vacuole modified to support bacterial growth, or escape from the primary
phagosome into the host cell cytoplasm. Phagosomal escape is best studied in
Listeria monocytogenes in which a pore-forming cytolysin and two phospholipases
are involved in the lysis of the phagosomal membrane. The mechanisms of and
requirements for cytoplasmic growth are less clear but there is growing evidence
that proficient replication of bacteria in the cytoplasmic compartment requires
specific bacterial and cellular preconditions.
PMID- 10679421
TI - Effector proteins of phytopathogenic bacteria: bifunctional signals in virulence
and host recognition.
AB - Phytopathogenic bacteria deliver effectors of disease into plant hosts via a Type
III secretion system. These Type III effectors have genetically determined roles
in virulence. They also are among the components recognized by the putative
receptors of the plant innate immune system. Recent breakthroughs include
localization of some of these Type III effectors to specific host cell
compartments, and the first dissection of pathogenicity islands that carry them.
PMID- 10679422
TI - Bacterial adaptation to host innate immunity responses.
AB - Several recent reports show that different bacterial components trigger innate
and inflammatory responses in host organisms. In parallel, selected bacterial
virulence factors have been identified that interfere with corresponding
responses. In many cases, this involves interference with host proinflammatory
signal transduction pathways, whereas in selected cases bacterial virulence
factors interfere with host antibacterial mechanisms. This indicates that
bacteria, besides activating cellular responses, also have the capacity to
directly interact with branches of the innate defence.
PMID- 10679423
TI - Borrelia pathogenesis research in the post-genomic and post-vaccine era.
AB - In the two years after publication of the genome sequence of Borrelia burgdorferi
and reports on human field trials of a vaccine against Lyme borreliosis, there
has been further progress in understanding of host-parasite interactions during
Lyme borreliosis and relapsing fever. Some mechanisms that Borrelia spirochetes
use to avoid elimination and to persist in the host are novel. In addition, the
recent discovery of antigenic variation in the Lyme disease agent B. burgdorferi
adds to the complexity of the possible virulence properties of this human
pathogen.
PMID- 10679424
TI - Manipulating the host to study bacterial virulence.
AB - The ability to manipulate animal hosts as well as bacterial pathogens greatly
expands the utility of in vivo models of infection. For example, the construction
of mice that harbor human tissues or express specific transgenes can provide
ligand-receptor interactions that are essential for pathogenesis. Interactions
between virulence factors and specific host defenses can sometimes be resolved by
challenging selectively immuno deficient mice with bacteria containing virulence
gene mutations. Transgenic animals expressing inducible reporters can be used to
conveniently identify cells in which specific response pathways have been
activated during infection. These and other approaches promise to improve the
quality of information obtainable from in vivo assessments of pathogenesis.
PMID- 10679425
TI - Endotoxin, toll-like receptor 4, and the afferent limb of innate immunity.
AB - Positional cloning work and subsequent biochemical analyses have revealed that
Toll-like receptor 4 (Tlr4) transduces the lipopolysaccharide (LPS) signal,
alerting the host to infection by Gram-negative bacteria. Moreover, it appears
that the LPS sensing pathway is a solitary one: disruption of Tlr4 causes
complete unresponsiveness to LPS. As several Tlr family members exist in
vertebrates, it appears likely that the innate immune system defends the host by
recognizing a small number of structurally conserved molecules that distinguish
the microbial world from tissues of the host.
PMID- 10679426
TI - Signaling mechanisms in the antimicrobial host defense of Drosophila.
AB - Drosophila has appeared in recent years as a powerful model to study innate
immunity. Several papers published in the past year shed light on the role of the
three Rel proteins Dorsal, Dif and Relish in the regulation of antimicrobial
peptide expression. In addition, the discovery that a blood serine protease
inhibitor is involved in the control of the antifungal response indicates that
Toll is activated upon triggering of a proteolytic cascade and does not function
as a Drosophila pattern recognition receptor.
PMID- 10679427
TI - Development of neuron-neuron synapses.
AB - Our understanding of neuronal synapse development has advanced in recent years.
The development of glycinergic synapses appears to depend on gephyrin and glycine
receptor activity. Molecular characterization of the structure and development of
glutamatergic synapses is in progress, but the underlying mechanisms remain
unclear. Activity-dependent mechanisms and specific molecules that regulate the
morphological development of dendritic spines have recently been identified.
PMID- 10679428
TI - Critical periods during sensory development.
AB - Recent studies have made progress in characterizing the determinants of critical
periods for experience-dependent plasticity. They highlight the role of
neurotrophins, NMDA receptors and GABAergic inhibition. In particular, genetic
manipulation of a single molecule, brain-derived neurotrophic factor (BDNF), has
been shown to alter the timing of the critical period of plasticity in mouse
visual cortex, establishing a causal relation between neurotrophin action, the
development of visual function, and the duration of the critical period.
PMID- 10679429
TI - The GDNF family ligands and receptors - implications for neural development.
AB - The glial cell line derived neurotrophic factor (GDNF) family has recently been
expanded to include four members, and the interactions between these neurotrophic
factors and their unique receptor system is now beginning to be understood.
Furthermore, analysis of mice lacking the genes for GDNF, neurturin, and their
related receptors has confirmed the importance of these factors in
neurodevelopment. The results of such analyses reveal numerous similarities and
potential overlaps in the way the GDNF and the nerve growth factor (NGF) families
regulate development of the peripheral nervous system.
PMID- 10679430
TI - Vnd/nkx, ind/gsh, and msh/msx: conserved regulators of dorsoventral neural
patterning?
AB - Expression of vnd in ventral, ind in intermediate, and msh in dorsal columns of
fly neurectoderm, and of homologous gene families in corresponding domains of
vertebrate neurectoderm, suggests that elements of dorsoventral neural patterning
have been evolutionarily conserved. However, upstream signaling pathways
regulating this columnar gene expression pattern appear to have diverged
significantly throughout evolution. In addition, while recent loss-of-function
studies in flies and mice indicate that these three genes may have a conserved
role in regional specification, there is no obvious conservation of the
particular cell fates deriving from corresponding domains. The three-column
expression pattern may thus represent a developmental mechanism that is more
resistant to evolutionary changes than genetic events upstream or downstream of
it.
PMID- 10679431
TI - Molecular mechanisms for activity-regulated protein synthesis in the synapto
dendritic compartment.
AB - The creation of enduring modifications in synaptic efficacy requires new protein
synthesis. Neurons face the formidable challenge of directing these newly made
proteins to the appropriate subset of synapses. One attractive solution to this
problem is the local translation of mRNAs that are targeted to dendrites and
perhaps to synapses themselves. The molecular mechanisms mediating such local
protein synthesis, notably CPEB-mediated cytoplasmic polyadenylation, are now
being elucidated.
PMID- 10679432
TI - Axonal signals in the assembly of neural circuitry.
AB - Recent work in Drosophila and rodents has revealed that proteins transported
along axons and delivered to pathway and target cell populations play important
roles in the construction of neural circuitry. Interestingly, the parallels
between these systems may extend to the identities of some of the molecules
involved.
PMID- 10679433
TI - Asymmetric division of Drosophila neural stem cells: a basis for neural
diversity.
AB - Recent studies of Drosophila neural precursor cells have unveiled the essential
roles played by asymmetric cell divisions in the determination of cell fates
during neural development. Our understanding now extends to the molecular nature
of the cell polarity that underlies asymmetric divisions. This polarity is
conserved among neural stem cells, epithelial cells and fertilized eggs.
PMID- 10679434
TI - Transcriptional mechanisms in the development of motor control.
AB - Considerable progress has been made in understanding how combinatorially
expressed transcription factors control the development of neuronal subtypes in
the fly and vertebrate central nervous systems. The mode of action of many of
these factors has been conserved from invertebrates to vertebrates throughout
evolution, such as the formation and regulation of specific transcriptional
complexes, the utilization of repressors for maintaining specificity, and the use
of phosphorylation as an important means for transiently altering transcriptional
activity.
PMID- 10679435
TI - Notch and presenilins in vertebrates and invertebrates: implications for neuronal
development and degeneration.
AB - Recent progress in elucidating the biology of Notch and presenilin has revealed a
close functional relationship between these two proteins during cell fate
determination in worms, flies and humans. Presenilins are required for the
putatively intramembranous proteolysis of Notch to release its intracellular
domain to the nucleus. This finding establishes a specific biochemical role for
presenilins in Notch signaling and interfaces with emerging evidence about how
frizzled, disheveled and numerous other genes regulate the highly complex Notch
pathway. Advances in understanding Notch and presenilin functions in the
differentiation of neurons and non-neural cells have important implications not
only for development but also for late-life degenerative disorders such as
Alzheimer's disease.
PMID- 10679436
TI - Active killing of neurons during development and following stress: a role for
p75(NTR) and Fas?
AB - Evidence for active triggering of neuronal death continues to accumulate. The
transmembrane receptors p75(NTR) and Fas can trigger (and in some cases are
required for) programmed cell death of the neurons that express them, through
signalling pathways that are regulated by a variety of cytoplasmic effectors.
Neuronal death induced by trophic deprivation often requires Fas signalling,
further blurring the boundaries between naturally occurring and stress-induced
neuronal death.
PMID- 10679437
TI - Get to know your stem cells.
AB - Our view of the central nervous system has changed dramatically over the past few
years. It is now well established that new neurons are generated continuously in
adult mammals, including humans. These neurons derive from self-renewing
multipotent neural stem cells. The identify of these stem cells has recently been
unveiled.
PMID- 10679438
TI - Semaphorins and their receptors in vertebrates and invertebrates.
AB - The semaphorins are a family of intercellular signaling proteins that has grown
to include 19 identified members in higher vertebrates. Several of its members
act as axonal guidance molecules. One participates in signaling in the immune
system. The majority, however, do not yet have known biological functions. Recent
studies have shown that neuropilins and plexins act as receptors for semaphorins.
The most important challenge for the future is to define the biological roles of
semaphorins in vivo.
PMID- 10679439
TI - From Abl to actin: Abl tyrosine kinase and associated proteins in growth cone
motility.
AB - The Abl tyrosine kinase plays an important role in axonogenesis. Recent reports
indicate that this role involves interaction with several different protein
families, including LAR phosphatases, catenin/cadherin cell adhesion complexes,
Trio family GEFs, and Ena/VASP family actin regulatory proteins. These findings
suggest that Abl and its associated proteins may regulate cell adhesion and actin
polymerization, thereby regulating growth cone motility during axonogenesis.
PMID- 10679440
TI - Rapid dendritic movements during synapse formation and rearrangement.
AB - Major technical advances in the imaging of live cells have led to a recent flurry
of studies demonstrating how dendrites remodel dynamically during development.
Taken together with our current understanding of axonal development, these
studies help provide a more unified picture of how neural circuits might be
formed altered or maintained throughout life.
PMID- 10679441
TI - Discussion point. The case for floor plate induction by the notochord.
PMID- 10679442
TI - The broken mouse: the role of development, plasticity and environment in the
interpretation of phenotypic changes in knockout mice.
AB - With the advent of gene knockout technology has arisen the problem of how to
interpret the resulting phenotypic changes in mice lacking specific genes. This
problem is especially relevant when applied to behavioral phenotypes of knockout
mice, which are difficult to interpret. Of particular interest are the roles of
development and compensatory changes, as well as other factors, such as the
influence of the gene knockout on nearby genes, the effect of the genetic
background strain, maternal behavioral influences, and pleiotrophy.
PMID- 10679443
TI - Discussion point. Origin and specification of the neural tube floor plate:
insights from the chick and zebrafish.
PMID- 10679444
TI - Slit proteins: key regulators of axon guidance, axonal branching, and cell
migration.
AB - In the past year, Slit proteins have been identified as important regulators of
axon guidance and cell migration in Drosophila and vertebrates. Remarkably, they
were simultaneously identified as negative regulators, repelling various axonal
and cell migrations in both invertebrates and vertebrates, and as positive
regulators, stimulating branching and extension of at least one class of axons in
vertebrates.
PMID- 10679445
TI - Cell signaling within the shoot meristem.
AB - Shoot apical meristems are self-renewing stem cell populations that generate all
of the above-ground organs (i.e. stems, leaves and flowers) of higher plants.
Recent studies have identified new molecular components required for proper shoot
meristem activity, and they have revealed that complex, intercellular
communication pathways play important roles in coordinating meristem function.
PMID- 10679446
TI - How plants tell the time.
AB - The components of the circadian system that have recently been discovered in
plants share some characteristics with those from cyanobacterial, fungal and
animal circadian clocks. Light input signals to the clock are contributed by
multiple photoreceptors: some of these have now been shown to function
specifically in response to light of defined wavelength and fluence rate. New
reports of clock-controlled processes and genes are highlighting the importance
of time management for plant development.
PMID- 10679447
TI - The YABBY gene family and abaxial cell fate.
AB - The establishment of abaxial-adaxial polarity in lateral organs involves factors
intrinsic to the primordia and interactions with the apical meristem from which
they are derived. Recently, a small plant-specific family of genes, the YABBY
gene family, has been proposed to specify abaxial cell fate. Each asymmetric
above-ground lateral organ expresses at least one member of the family in a polar
manner, and loss- and gain-of-function studies indicate that they are sufficient
to specify abaxial cell fate and that they act in both distinct and redundant
manners.
PMID- 10679448
TI - Three ways to learn the ABCs.
AB - The ABC model of flower development represents a milestone in explaining how the
fate of emerging floral organ primordia is specified. This model states that
organ identity is specified by different combinations of the activities of the A,
B and C class homeotic genes. In spite of the remarkable simplicity of this
model, the complex regulatory interactions that establish the initial pattern of
A, B and C gene activity have yet to be fully explained. It has been shown that
the LEAFY gene functions early to promote flower meristem identity, and that it
is subsequently required for the normal expression of the ABC genes. Recently,
LEAFY has been identified as an immediate upstream regulator of the floral
homeotic genes, thus opening up an avenue to examine the transcriptional
interactions that underlie floral patterning.
PMID- 10679449
TI - Genetics of gametophyte biogenesis in Arabidopsis.
AB - The identification of several mutations and genes involved in sporogenesis and
gametogenesis has initiated a genetic framework for understanding gametophyte
biogenesis. Recent advances include the molecular characterization of genes
required for sporocyte formation and meiosis. These studies have revealed some
unexpected interactions linking development of sporophytic cells and tissues with
initiation and progression of gametophyte development in angiosperms.
PMID- 10679450
TI - Brassinosteroid signal transduction: still casting the actors.
AB - Significant advances in the genetic dissection of brassinosteroid biosynthesis
and signaling have been made during the past few years. Genetic and biochemical
data have helped to elucidate the pathways of biosynthesis of brassinolide, the
most active brassinosteroid. In addition, several models have been put forward
for the perception of brassinolide by its putative receptor, BRI1, a ubiquitously
expressed plasma membrane localized protein kinase. These studies provide the
basic framework for future analysis of brassinosteroid signaling.
PMID- 10679451
TI - New genes and new biological roles for expansins.
AB - Expansins are extracellular proteins that loosen plant cell walls in novel ways.
They are thought to function in cell enlargement, pollen tube invasion of the
stigma (in grasses), wall disassembly during fruit ripening, abscission and other
cell separation events. Expansins are encoded by two multigene families and each
gene is often expressed in highly specific locations and cell types. Structural
analysis indicates that one expansin region resembles the catalytic domain of
family-45 endoglucanases but glucanase activity has not been detected. The genome
projects have revealed numerous expansin-related sequences but their putative
wall-loosening functions remain to be assessed.
PMID- 10679452
TI - Developmental complexities of simple leaves.
AB - Recent papers have explored early events in the development of simple leaves.
Functional compartmentalization of the shoot apical meristem correlates with
distinct fields of cells connected by plasmodesmata. Molecules important in the
initiation of phyllotactic pattern are described and the relationship between
dorsoventral patterning and lateral leaf expansion is investigated.
PMID- 10679453
TI - Response of plant development to environment: control of flowering by daylength
and temperature.
AB - The transition from vegetative growth to flowering is often controlled by
environmental conditions and influenced by the age of the plant. Intensive
genetic analysis has identified pathways that regulate flowering time of
Arabidopsis in response to daylength or low temperature (vernalization). These
pathways are proposed to converge to regulate the expression of genes that act
within the floral primordium and promote floral development. In the past year,
genes that confer the responses to daylength or vernalization have been cloned
and have enabled aspects of the genetic models to be tested at the molecular
level.
PMID- 10679454
TI - Division decisions and the spatial regulation of cytokinesis.
AB - Cytokinesis in plant cells in accomplished when a membranous cell plate is guided
to a pre-established division site. The orientation of the new wall establishes
the starting position of a cell in a growing tissue, but the impact of this
position on future development varies. Recently, proteins have been identified
that participate in forming, stabilizing and guiding the cell plate to the
correct division site. Mutations that affect cytokinesis with varying impacts on
plant development are providing information about the mechanics of cytokinesis
and also about how the division site is selected.
PMID- 10679455
TI - Polarity: the role of localized secretion.
AB - Studies of single cells from brown algae suggest that localized secretions
stabilize the polar axis resulting in an asymmetry in the cell wall. This
cortical asymmetry appears to play a role in orienting the plane of cell division
and in determining the different fates of the resulting daughter cells. Recent
studies indicate that similar processes may operate in seed plants.
PMID- 10679456
TI - Enzymes that catalyse the restructuring of proteins.
AB - The large enzyme families of protein disulfide isomerases and peptidyl prolyl
cis/trans isomerases have been shown to assist polypeptide restructuring. Various
folding states of polypeptides may serve as substrates of the catalysed reaction.
Our understanding of the cellular function of these enzymes is increasing as a
result of the availability of more specific inhibitors, the discovery of natural
substrates and the use of genetically modified organisms. Further highlights of
these studies include insights into the three-dimensional structures of enzyme
ligand complexes, as well as into the mechanism of slow folding phases on the
atomic level.
PMID- 10679457
TI - DNA helicases: 'inching forward'.
AB - Recently determined crystal structures of PcrA helicase complexed with a DNA
substrate have revealed details of the helicase mechanism. PcrA and UvrD
helicases have been shown to be functional as monomers, challenging previous
suggestions that all helicases are required to be oligomeric. Crystal structures
of the hexameric helicases RepA and T7 gene 4 explain the formation of hexameric
assemblies from identical monomers with RecA-like folds, but their molecular
mechanism remains elusive.
PMID- 10679458
TI - The many routes of bacterial transfer RNAs after aminoacylation.
AB - Subsequent to their aminoacylation, tRNAs are subject to specific maturation
and/or correction processes. Aminoacylated tRNAs ready for use in translation are
then specifically channelled to the ribosomal A or P sites. Structural and
biochemical studies have opened the way towards furthering our understanding of
these routes to the ribosome, which involve a strict distinction between
initiator and elongator tRNAs.
PMID- 10679459
TI - Structure and in vivo function of Hsp90.
AB - Until recently, Hsp90 was one of the least well understood of the molecular
chaperones, but considerable progress is now being made in unravelling its
biochemistry. Hsp90 has now been shown to possess an inherent ATPase that is
essential for the activation of authentic 'client' proteins in vivo and in vitro.
The molecular detail of Hsp90's interactions with co-chaperones is also becoming
clearer and the identification of key roles in assembling regulatory and
signalling pathways has made it a target for anticancer drug development. Despite
this, a clear understanding of how Hsp90 contributes to the folding and/or
activation of its client proteins remains some way off.
PMID- 10679460
TI - Mammalian prion proteins.
AB - The past two years have seen the extension of our knowledge on the cellular prion
protein structure with new NMR data on both the hamster and human proteins. In
addition, the folding dynamics of two cellular prion proteins have been
elucidated. There are now several examples of recombinant prion proteins that are
able to adopt different conformations in solution and recent work on the
molecular basis of prion strains has done much to consolidate the protein-only
hypothesis. Important advances in relating disease to structure have also been
made through the identification of the minimal prion protein fragment that is
capable of conferring susceptibility to and propagation of the scrapie agent.
PMID- 10679461
TI - Structural basis of mRNA cap recognition by proteins.
AB - Crystal structures have recently become available for two proteins (VP39 and
eIF4E) complexed with their cognate ligand - the mRNA cap. Despite their total
structural dissimilarity, both proteins bind N7-methylguanine between two
parallel aromatic sidechains. The resulting stacked arrangement governs their
high specificity for the alkylated form of the nucleobase.
PMID- 10679462
TI - Amyloid fibrillogenesis: themes and variations.
AB - Recent progress has improved our knowledge of how proteins form amyloid fibrils.
Both 'natively unfolded' and globular proteins have been shown to initiate
fibrillization by adopting a partially structured conformation. Oligomeric
prefibrillar intermediates have been extensively characterized with respect to
their morphology and temporal evolution. Three-dimensional models obtained using
biophysical and computational methods have provided information about fibril
structure. All of these advances suggest common features of self-assembly
pathways, with subtle variations accounting for differences among distinct
amyloid fibrils.
PMID- 10679463
TI - Protein folding mechanisms: new methods and emerging ideas.
AB - During the past year, advances in our understanding of folding mechanisms have
been made through detailed experimental and theoretical studies of a number of
proteins. The development of new methods has allowed the earliest events in
folding to be probed and the measurement of folding at the level of individual
molecules is now possible, opening the door to exciting new experiments.
PMID- 10679464
TI - Small heat-shock proteins and their potential role in human disease.
AB - The elevated expression of stress proteins is considered to be a universal
response to adverse conditions, representing a potential mechanism of cellular
defense against disease and a potential target for novel therapeutics, including
gene therapy and chaperone-modulating reagents. Recently, a single mutation in
the small heat-shock protein human alphaB-crystallin was linked to desmin-related
myopathy, which is characterized by abnormal intracellular aggregates of
intermediate filaments in human muscle. New findings demonstrate that the high
level of expression of stress proteins can contribute to an autoimmune response
and can protect proteins that contribute to disease processes.
PMID- 10679465
TI - Implications of macromolecular crowding for protein assembly.
AB - Recent studies have led to increased appreciation of the influence of excluded
volume in solutions of high total macromolecular content ('macromolecular
crowding') upon the various classes of reaction that lead to the assembly of
proteins and protein complexes. In general, crowding is expected to stabilize
native protein structure relative to less compact non-native structures and to
favor the formation of functional complexes of native proteins. Under certain
pathological conditions, 'overcrowding' may enhance the formation of
nonfunctional aggregates of non-native protein (e.g. amyloid and inclusion
bodies).
PMID- 10679466
TI - Single-stranded-RNA binding proteins.
AB - Our knowledge of protein interactions with RNA molecules has been, so far,
largely restricted to cases in which the RNA itself is folded into a secondary
and/or tertiary structure stabilised by intramolecular base pairing and stacking.
Until recently, only limited structural information has been available about
protein interactions with single-stranded RNA. A breakthrough in our
understanding of these interactions came in 1999, with the determination of four
crystal structures of protein complexes with extended single-stranded RNA
molecules. These structures revealed wonderfully satisfying patterns of the
ability of proteins to accommodate RNA bases, with the sugar-phosphate backbone
often adopting conformations that are different from the classical double helix.
PMID- 10679467
TI - Protein folding in vivo: the importance of molecular chaperones.
AB - The contribution of the two major cytosolic chaperone systems, Hsp70 and the
cylindrical chaperonins, to cellular protein folding has been clarified by a
number of recent papers. These studies found that, in vivo, a significant
fraction of newly synthesized polypeptides transit through these chaperone
systems in both prokaryotic and eukaryotic cells. The identification and
characterization of the cellular substrates of chaperones will be instrumental in
understanding how proteins fold in vivo.
PMID- 10679468
TI - Insights into transcription: structure and function of single-subunit DNA
dependent RNA polymerases.
AB - Single-subunit RNA polymerases are widespread throughout prokaryotic and
eukaryotic organisms, and also viruses. T7 RNA polymerase is one of the simplest
DNA-dependent enzymes, capable of transcribing a complete gene without the need
for additional proteins. During the past two years, three illuminating crystal
structures of T7 RNA polymerase complexed to either T7 lysozyme, which is a
transcription inhibitor, an open promoter DNA fragment or a promoter DNA fragment
being transcribed into RNA at initiation have been determined. For the first
time, these structures describe in detail the intricate mechanism of
transcription initiation by T7 RNA polymerase, which is likely to be a general
model for other related RNA polymerases.
PMID- 10679469
TI - Recognition of distorted DNA structures by HMG domains.
AB - Recent biochemical and structural studies have shown that the preferential
recognition of distorted DNA structures, including DNA bulges, four-way junctions
and cis-platinated DNA, by HMG domains is dependent on residues immediately
preceding the second alpha helix of the L-shaped HMG domain.
PMID- 10679470
TI - Winged helix proteins.
AB - The winged helix proteins constitute a subfamily within the large ensemble of
helix-turn-helix proteins. Since the discovery of the winged helix/fork head
motif in 1993, a large number of topologically related proteins with diverse
biological functions have been characterized by X-ray crystallography and
solution NMR spectroscopy. Recently, a winged helix transcription factor (RFX1)
was shown to bind DNA using unprecedented interactions between one of its
eponymous wings and the major groove. This surprising observation suggests that
the winged helix proteins can be subdivided into at least two classes with
radically different modes of DNA recognition.
PMID- 10679471
TI - Mysteries of magnesium homeostasis.
PMID- 10679472
TI - Myoendothelial gap junctions: the gap is there, but does EDHF go through it?
PMID- 10679473
TI - Vascular endothelial growth factor: A Jack-of-all-trades or a nonspecific stress
gene?
PMID- 10679474
TI - Viral myocarditis: receptors that bridge the cardiovascular with the immune
system?
PMID- 10679475
TI - Calcineurin-mediated hypertrophy protects cardiomyocytes from apoptosis in vitro
and in vivo: An apoptosis-independent model of dilated heart failure.
AB - We have previously shown that the calcium-calmodulin-regulated phosphatase
calcineurin (PP2B) is sufficient to induce cardiac hypertrophy that transitions
to heart failure in transgenic mice. Given the rapid onset of heart failure in
these mice, we hypothesized that calcineurin signaling would stimulate myocardial
cell apoptosis. However, utilizing multiple approaches, we determined that
calcineurin-mediated hypertrophy protected cardiac myocytes from apoptosis,
suggesting a model of heart failure that is independent of apoptosis.
Adenovirally mediated gene transfer of a constitutively active calcineurin cDNA
(AdCnA) was performed in cultured neonatal rat cardiomyocytes to elucidate the
mechanism whereby calcineurin affected myocardial cell viability. AdCnA
infection, which induced myocyte hypertrophy and atrial natriuretic factor
expression, protected against apoptosis induced by 2-deoxyglucose or
staurosporine, as assessed by terminal deoxynucleotidyltransferase-mediated dUTP
nick end labeling (TUNEL) labeling, caspase-3 activation, DNA laddering, and
cellular morphology. The level of protection conferred by AdCnA was similar to
that of adenoviral Bcl-x(L) gene transfer or hypertrophy induced by
phenylephrine. In vivo, failing hearts from calcineurin-transgenic mice did not
demonstrate increased TUNEL labeling and, in fact, demonstrated a resistance to
ischemia/reperfusion-induced apoptosis. We determined that the mechanism whereby
calcineurin afforded protection from apoptosis was partially mediated by nuclear
factor of activated T cells (NFAT3) signaling and partially by Akt/protein kinase
B (PKB) signaling. Although calcineurin activation protected myocytes from
apoptosis, inhibition of calcineurin with cyclosporine was not sufficient to
induce TUNEL labeling in Gqalpha-transgenic mice or in cultured cardiomyocytes.
Collectively, these data identify a calcineurin-dependent mouse model of dilated
heart failure that is independent of apoptosis.
PMID- 10679476
TI - Targeted disruption of the mouse Sod I gene makes the hearts vulnerable to
ischemic reperfusion injury.
AB - The role of Cu/Zn-superoxide dismutase (SOD) in myocardial ischemic reperfusion
injury was studied by using a mouse model with targeted disruption of the mouse
Sod I gene. Inactivation of the functional mouse Sod I gene in hearts by gene
targeting (Sod I(+/-)) resulted in a 50% reduction of Cu/Zn-SOD mRNA and
significant reduction of Cu/Zn-SOD enzyme activity compared with that of wild
type Sod I(+/+) mice. Cu/Zn-SOD mRNA could not be detected in Sod I(-/-) heart.
The isolated buffer-perfused hearts from the knockout mice devoid of any
functional copy of the Sod I (Sod I(-/-)) and matched nontransgenic control mice
were subjected to 30 minutes of global ischemia followed by 2 hours of
reperfusion. For both groups of mice, the postischemic functional recovery for
the hearts was lower than the baseline, but the recovery for the Sod I(-/-) was
less compared with the wild-type mice. Thus, the postischemic recovery of the
developed force and the maximum first derivative of the developed force were
consistently lower for the Sod I(-/-) mouse hearts compared with wild-type
control hearts. The coronary flow was lower compared with the baseline levels for
both groups of hearts, but there was no significant difference between the
groups. The myocardial infarction determined from the ratio of infarct size/area
of risk was higher for the Sod I(-/-) mice compared with the control mice. The
amount of creatine kinase release from the wild-type mouse hearts was less
compared with the Sod I(-/-) mouse hearts. In concert, a reduced amount of
oxidative stress was found in the hearts of wild-type mice compared with Sod I(-/
) mouse hearts. These results documented that Sod I(-/-) mouse hearts were more
susceptible to ischemic reperfusion injury compared with corresponding wild-type
mouse hearts, suggesting that the Sod I gene constitutes an important defense
element for the hearts.
PMID- 10679477
TI - Myocardial glucose uptake is regulated by nitric oxide via endothelial nitric
oxide synthase in Langendorff mouse heart.
AB - Although the role of nitric oxide (NO) in the modulation of vascular tone has
been studied and well understood, its potential role in the control of myocardial
metabolism is only recently evident. Several lines of evidence indicate that NO
regulates myocardial glucose metabolism; however, the details and mechanisms
responsible are still unknown. The aim of this study was to further define the
role of NO in the control of myocardial glucose metabolism and the nitric oxide
synthase (NOS) isoform responsible using transgenic animals lacking endothelial
NOS (ecNOS). In the present study, we examined the regulation of myocardial
glucose uptake using isometrically contracting Langendorff-perfused hearts from
normal mice (C57BL/6J), mice with defects in the expression of ecNOS [ecNOS (-/
)], and its heterozygote [ecNOS (+/-)], and wild-type mice [ecNOS (+/+)] (n=6,
respectively). In hearts from normal mice, little myocardial glucose uptake was
observed. This myocardial glucose uptake increased significantly in the presence
of N(omega)-nitro-L-arginine methyl ester (L-NAME). Similarly, in the hearts from
ecNOS (-/-), glucose uptake was much greater than in normal mice, whereas
myocardial glucose uptake of ecNOS (+/-) and ecNOS (+/+) mice was not different
from normal mice. In addition, myocardial glucose uptake of ecNOS (+/-) and ecNOS
(+/+) mice increased significantly in the presence of L-NAME. At a workload of
800 g. beats/min, L-NAME increased glucose uptake from 0.1+/-0.1 to 3+/-0.4
microg/min x mg in ecNOS (+/-) mice and from 0.2+/-0.1 to 2.7+/-0.7 microg/min x
mg in ecNOS (+/+) mice. Furthermore, in the hearts from ecNOS (-/-) mice, 8
bromoguanosine 3':5'-cyclic monophosphate (8-Br-cGMP), a cGMP analog or S-nitroso
N-acetylpenicillamine (SNAP), a NO donor essentially shut off glucose uptake, and
in hearts from ecNOS (+/-) mice, 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one
(ODQ), an inhibitor of cGMP, increased the glucose uptake significantly. These
results indicate clearly that cardiac NO production regulates myocardial glucose
uptake via a cGMP-dependent mechanism and strongly suggest that ecNOS plays a
pivotal role in this regulation. These findings may be important in the
understanding of the pathogenesis of the diseases such as ischemic heart disease,
heart failure, diabetes mellitus, hypertension, and hypercholesterolemia, in
which NO synthesis is altered and substrate utilization by the heart changes.
PMID- 10679478
TI - Expression of coxsackievirus and adenovirus receptor in hearts of rats with
experimental autoimmune myocarditis.
AB - The expression of coxsackievirus and adenovirus receptor (CAR) was dominant in
the brains and hearts of mice until the newborn phase. There is no detailed
information concerning the relation between the expression of CAR and development
of hearts. It is also uncertain whether CAR is able to be induced in adult hearts
after cardiac injury. We demonstrated that CAR was abundant in the hearts of
newborn rats but was barely detectable in the hearts of adult rats. The
expression of CAR in rat hearts with experimental autoimmune myocarditis, which
was induced by immunization of purified cardiac myosin, was serially
investigated. Active myocarditis was observed from day 15 after immunization. By
immunohistochemistry, cardiomyocytes were strongly stained for CAR antibody from
days 24 to 42. CAR mRNA was also detected from days 18 to 30 by using reverse
transcription-polymerase chain reaction. In the next experiment, the induction of
CAR on isolated cardiomyocytes was investigated. CAR was barely detectable in
cultured cardiomyocytes by Western blot analysis after isolation. This molecule
gradually appeared along with the creation of clusters and beating of
cardiomyocytes. Furthermore, the induction of CAR in cultured cardiomyocytes
increased after supplement with conditioned medium of rat splenocytes activated
by concanavalin A. In conclusion, rat CAR is expressed strongly in the hearts of
newborn rats and is suppressed in those of adult rats. The expression of CAR is
enhanced during the active phase of experimental autoimmune myocarditis and is
induced by inflammatory mediators. CAR may play a role in cell-to-cell contact
and adhesion of cardiomyocytes.
PMID- 10679479
TI - Immunoglobulin isotype determines pathogenicity in antibody-mediated myocarditis
in naive mice.
AB - Antimyosin reactivity is associated with cardiac damage in autoimmune
myocarditis, an inflammatory heart disease characterized by a cellular infiltrate
in the myocardium and myocyte necrosis. We are interested in the pathogenicity of
antimyosin antibodies and their ability to cause autoimmune myocarditis. We have
shown that antimyosin antibodies of the IgG isotype will induce disease in the
DBA/2 mouse. In the present study, we show that IgM antimyosin antibodies do not
induce myocarditis; however, these same antibodies become pathogenic when
converted to the IgG isotype. Although IgM antibodies can penetrate the
myocardium during cardiac inflammation, they are usually less able to leave the
vascular compartment and penetrate cardiac tissue, thus accounting for their lack
of pathogenicity. Thus, antimyosin B cells may be potentially pathogenic only
after antigen activation and heavy chain class switching or under conditions that
alter vascular permeability in the heart.
PMID- 10679480
TI - Intussusceptive angiogenesis: its role in embryonic vascular network formation.
AB - Intussusceptive angiogenesis is a novel mode of blood vessel formation and
remodeling, which occurs by internal division of the preexisting capillary plexus
without sprouting. In this study, the process is demonstrated in developing
chicken eye vasculature and in the chorioallantoic membrane by methylmethacrylate
(Mercox) casting, transmission electron microscopy, and in vivo observation. In a
first step of intussusceptive angiogenesis, the capillary plexus expands by
insertion of numerous transcapillary tissue pillars, ie, by intussusceptive
microvascular growth. In a subsequent step, a vascular tree arises from the
primitive capillary plexus as a result of intussusceptive pillar formation and
pillar fusions, a process we termed "intussusceptive arborization." On the basis
of the morphological observations, a 4-step model for intussusceptive
arborization is proposed, as follows: phase I, numerous circular pillars are
formed in rows, thus demarcating future vessels; phase II, formation of narrow
tissue septa by pillar reshaping and pillar fusions; phase III, delineation,
segregation, growth, and extraction of the new vascular entity by merging of
septa; and phase IV, formation of new branching generations by successively
repeating the process, complemented by growth and maturation of all components.
In contrast to sprouting, intussusceptive angiogenesis does not require intense
local endothelial cell proliferation; it is implemented primarily by
rearrangement and attenuation of the endothelial cell plates. In summary,
transcapillary pillar formation, ie, intussusception, is a central and probably
widespread process, which plays a role not only in capillary network growth and
expansion (intussusceptive microvascular growth), but also in vascular plexus
remodeling and tree formation (intussusceptive arborization).
PMID- 10679481
TI - The epsilon subtype of protein kinase C is required for cardiomyocyte connexin-43
phosphorylation.
AB - Gap junctions (GJs), composed of connexins, are intercellular channels ensuring
electric and metabolic coupling between cardiomyocytes. We have shown previously
that an endogenous mitogenic and cardioprotective protein, fibroblast growth
factor-2 (FGF-2), decreases cardiomyocyte GJ permeability by stimulating
phosphorylation of connexin-43 (Cx43). Identifying the kinase(s) phosphorylating
cardiac Cx43 may thus provide a way of modulating cardiac intercellular
communication. Because FGF-2 activates receptors linked to protein kinase C (PKC)
and mitogen-activated protein kinase, we first investigated participation of
these enzymatic systems in Cx43 phosphorylation. The inhibitor PD98059 blocked
activation of mitogen-activated protein kinase, but it did not prevent the FGF-2
effects on GJs. In contrast, the PKC inhibitor chelerythrine blocked the effects
of FGF-2 on Cx43 phosphorylation and permeability. Because the epsilon-isoform of
PKC localizes to plasma membrane sites, we examined whether it is directly
involved in the FGF-2-induced Cx43 phosphorylation. In nonstimulated myocytes,
PKCepsilon displayed a discontinuous pattern of localization at intercellular
contact sites and partial colocalization with Cx43. Treatment with FGF-2 or
phorbol 12-myristate 13-acetate induced a more continuous pattern of PKCepsilon
distribution, whereas the anti-Cx43 staining appeared to overlap extensively with
that of PKCepsilon. In immunoprecipitation experiments using specific anti-Cx43
antibodies, PKCepsilon but not PKCalpha coprecipitated with Cx43. FGF-2 increased
levels of coprecipitated PKCepsilon, suggesting increased association between
PKCepsilon and Cx43 on stimulation. Transient gene transfer and overexpression of
cDNAs coding for truncated or mutated dominant-negative forms of PKCepsilon
decreased cardiomyocyte Cx43 phosphorylation significantly. We conclude that PKC
mediates the FGF-2-induced effects on cardiac GJs and that PKCepsilon likely
interacts with and phosphorylates cardiac Cx43 at sites of intercellular contact.
PMID- 10679482
TI - Electrophysiological effects of remodeling cardiac gap junctions and cell size:
experimental and model studies of normal cardiac growth.
AB - The increased incidence of arrhythmias in structural heart disease is accompanied
by remodeling of the cellular distribution of gap junctions to a diffuse pattern
like that of neonatal cardiomyocytes. Accordingly, it has become important to
know how remodeling of gap junctions due to normal growth hypertrophy alters
anisotropic propagation at a cellular level (V(max)) in relation to conduction
velocities measured at a macroscopic level. To this end, morphological studies of
gap junctions (connexin43) and in vitro electrical measurements were performed in
neonatal and adult canine ventricular muscle. When cells enlarged, gap junctions
shifted from the sides to the ends of ventricular myocytes. Electrically, normal
growth produced different patterns of change at a macroscopic and microscopic
level. Although the longitudinal and transverse conduction velocities were
greater in adult than neonatal muscle, the anisotropic velocity ratios were the
same. In the neonate, mean V(max) was not different during longitudinal (LP) and
transverse (TP) propagation. However, growth hypertrophy produced a selective
increase in mean TP V(max) (P<0.001), with no significant change in mean LP
V(max). Two-dimensional neonatal and adult cellular computational models show
that the observed increases in cell size and changes in the distribution of gap
junctions are sufficient to account for the experimental results. Unexpectedly,
the results show that cellular scaling (cell size) is as important (or more so)
as changes in gap junction distribution in determining TP properties. As the
cells enlarged, both mean TP V(max) and lateral cell-to-cell delay increased.
V(max) increased because increases in cell-to-cell delay reduced the electric
current flowing downstream up to the time of V(max), thus enhancing V(max). The
results suggest that in pathological substrates that are arrhythmogenic,
maintaining cell size during remodeling of gap junctions is important in
sustaining a maximum rate of depolarization.
PMID- 10679483
TI - Acidosis inhibits endothelial cell apoptosis and function and induces basic
fibroblast growth factor and vascular endothelial growth factor expression.
AB - Endothelial cells are exposed to an acidotic environment in a variety of
pathological and physiological conditions. However, the effect of acidosis on
endothelial cell function is still largely unknown, and it was evaluated in the
present study. Bovine aortic endothelial cells (BAECs) were grown in bicarbonate
buffer equilibrated either with 20% CO(2) (pH 7.0, acidosis) or 5% CO(2) (pH 7.4,
control). Acidosis inhibited BAEC proliferation in 10% FCS, whereas by day 7 in
serum-free medium, cell number was 3-fold higher in acidotic cells than in
control cells. Serum deprivation enhanced BAEC apoptosis, and apoptotic cell
death was markedly inhibited by acidosis. Additionally, acidosis inhibited FCS
stimulated migration in a modified Boyden chamber assay and FCS-stimulated
differentiation into capillary-like structures on reconstituted basement membrane
proteins. Conditioned media from BAECs cultured for 48 hours either at pH 7.0 or
pH 7.4 enhanced BAEC proliferation and migration at pH 7.4, and both effects were
more marked with conditioned medium from BAECs grown in acidotic than in control
conditions. Acidosis enhanced vascular endothelial growth factor (VEGF) and basic
fibroblast growth factor (bFGF) mRNA expression as well as bFGF secretion, and a
blocking bFGF antibody inhibited enhanced BAEC migration in response to
conditioned medium from acidotic cells. These results show that acidosis protects
endothelial cells from apoptosis and inhibits their proangiogenic behavior
despite enhanced VEGF and bFGF mRNA expression and bFGF secretion.
PMID- 10679484
TI - Hypoxic regulation of inducible nitric oxide synthase via hypoxia inducible
factor-1 in cardiac myocytes.
AB - The relationship between hypoxia and regulation of nitric oxide synthase (NOS) in
myocardial tissue is not well understood. We investigated the role of hypoxia
inducible factor-1 (HIF-1) on expression of the inducible NOS (iNOS) in
myocardial cells in vivo and in vitro. In situ hybridization in myocardial tissue
from rats exposed to hypoxia for 3 weeks demonstrated increased iNOS mRNA
expression. Northern analysis of RNA from hearts of those animals and from cells
exposed to hypoxia for 12 hours in vitro demonstrated an increase of HIF-1 RNA
expression. Electrophoretic mobility shift assays using oligonucleotides
containing the iNOS HIF-1 DNA binding site and nuclear extracts from cardiac
myocytes showed induction of specific DNA binding in cells subjected to hypoxia.
Transient transfection of cardiac myocytes using the murine iNOS promoter
resulted in a 3.43-fold increase in promoter activity under hypoxia compared with
normoxia. Mutation or deletion of the HIF-1 site eliminated the hypoxic response.
As cytokines have been shown to regulate iNOS expression in myocardial cells,
cultured neonatal cardiac myocytes were stimulated with interleukin-1beta causing
a dramatic induction of iNOS protein expression under normoxia, with further
augmentation under hypoxia. Transient transfection of cells stimulated with
interleukin-1beta showed an increased iNOS promoter activity under normoxic
conditions compared with unstimulated cells, with a further increase in response
to hypoxia, which was dependent on HIF-1. These results demonstrate that hypoxia
causes an increase in iNOS expression in cardiac myocytes and that HIF-1 is
essential for the hypoxic regulation of iNOS gene expression.
PMID- 10679485
TI - Parallel stimulation of glucose and Mg(2+) accumulation by insulin in rat hearts
and cardiac ventricular myocytes.
AB - The stimulation of beta-adrenoceptors in cardiac cells results in a rapid loss of
cellular Mg(2+). Because insulin physiologically counteracts several of the
cellular effects mediated by the activation of beta-adrenoceptors and the
elevation of cytosolic cAMP levels, we investigated whether insulin
administration could prevent Mg(2+) mobilization from rat hearts and ventricular
myocytes. Rat hearts were perfused in a retrograde Langendorff system, and the
changes in extracellular Mg(2+) were measured by atomic absorbance
spectrophotometry. Pretreatment of the hearts with 6 nmol/L insulin completely
prevented the Mg(2+) extrusion induced by the beta-adrenergic agonist
isoproterenol. Furthermore, the administration of insulin per se induced an
accumulation of Mg(2+) by the heart. This accumulation was small but detectable
in the presence of 25 to 35 micromol/L [Mg(2+)](o) and increased in proportion to
[Mg(2+)](o). Insulin-mediated Mg(2+) accumulation was not observed in hearts
perfused with a medium devoid of glucose or with a medium containing the
inhibitors of glucose transport, cytochalasin B and phloretin. Insulin-stimulated
[(3)H]2-deoxyglucose accumulation was measured in collagenase-dispersed cardiac
ventricular myocytes in the presence of varying levels of [Mg(2+)](o). Glucose
transport was not observed below 25 micromol/L [Mg(2+)](o), and it also increased
in proportion to [Mg(2+)](o). Taken together, these results indicate the presence
of a major uptake of Mg(2+) into cardiac cells that is stimulated by insulin and
may require the insulin-induced operation of a glucose transporter. Hence,
extracellular and/or intracellular Mg(2+) may modulate glucose transport and/or
utilization.
PMID- 10679486
TI - Photodynamic therapy generates a matrix barrier to invasive vascular cell
migration.
AB - Photodynamic therapy (PDT) inhibits experimental intimal hyperplasia. PDT results
in complete vascular wall cell eradication with subsequent adventitia but minimal
media repopulation. This study was designed to test the hypothesis that PDT
alters the vascular wall matrix thereby inhibiting invasive cell migration, and
as such, provides an important barrier mechanism to favorably alter the vascular
injury response. Untreated smooth muscle cells (SMCs) and fibroblasts were seeded
on control and PDT-treated (100 J/cm(2); photosensitizer was chloroaluminum
sulfonated phthalocyanine, 5 microg/mL) 3-dimensional collagen matrix gels.
Invasive cell migration was temporally quantified by calibrated microscopy.
Zymography and ELISA assessed SMC matrix metalloproteinase levels. Molecular
changes of gel proteins and their susceptibility to collagenase were analyzed by
SDS-PAGE and Western blot. Limited pepsin digestion and histology were used to
assess the in vivo relevance of the model, using an established rat carotid
artery model at 1 and 4 weeks after balloon injury and PDT. PDT of 3-dimensional
matrix of gels led to a 52% reduction of invasive SMCs and to a 59% reduction of
fibroblast migration (P<0.001) but did not significantly affect secretion of
matrix metalloproteinases. PDT induced collagen matrix changes, including cross
linking, which resulted in resistance to protease digestion. PDT led to a durable
45% reduction in pepsin digestion susceptibility of treated arteries (P<0.001)
and inhibition of periadventitial cell migration into the media. These data
suggest that PDT of matrix gels generates a barrier to invasive cellular
migration. This newly identified effect on matrix proteins underscores its
pleiotropic actions on the vessel wall, and as such, PDT may be of considerable
potential therapeutic value to inhibit restenosis.
PMID- 10679487
TI - Incidence of myoendothelial gap junctions in the proximal and distal mesenteric
arteries of the rat is suggestive of a role in endothelium-derived
hyperpolarizing factor-mediated responses.
AB - Although the chemical nature of endothelium-derived hyperpolarizing factor (EDHF)
remains elusive, electrophysiological evidence exists for electrical
communication between smooth muscle cells and endothelial cells suggesting that
electrotonic propagation of hyperpolarization may explain the failure to identify
a single chemical factor as EDHF. Anatomical evidence for myoendothelial gap
junctions, or the sites of electrical coupling, is, however, rare. In the present
study, serial-section electron microscopy and reconstruction techniques have been
used to examine the incidence of myoendothelial gap junctions in the proximal and
distal mesenteric arteries of the rat where EDHF responses have been reported to
vary. Myoendothelial gap junctions were found to be very small in the mesenteric
arteries, the majority being <100 nm in diameter. In addition, they were
significantly more common in the distal compared with the proximal regions of
this arterial bed. Pentalaminar gap junctions between adjacent endothelial cells
were much larger and were common in both proximal and distal mesenteric arteries.
These latter junctions were frequently found near the myoendothelial gap
junctions. These results provide the first evidence for the presence of sites for
electrical communication between endothelial cells and smooth muscle cells in the
mesenteric vascular bed. Furthermore, the relative incidence of these sites
suggests that there may be a relationship between the activity of EDHF and the
presence of myoendothelial gap junctions.
PMID- 10679488
TI - Transcriptional and posttranscriptional regulation of endothelial nitric oxide
synthase expression by hydrogen peroxide.
AB - Diverse stimuli, including shear stress, cyclic strain, oxidized LDL,
hyperglycemia, and cell growth, modulate endothelial nitric oxide synthase (eNOS)
expression. Although seemingly unrelated, these may all alter cellular redox
state, suggesting that reactive oxygen intermediates might modulate eNOS
expression. The present study was designed to test this hypothesis. Exposure of
bovine aortic endothelial cells for 24 hours to paraquat, a superoxide (O(2)(-*))
generating compound, did not affect eNOS mRNA levels. However, cotreatment with
paraquat and either Cu(2+)/Zn(2+) superoxide dismutase or the superoxide
dismutase mimetic tetrakis(4-benzoic acid)porphyrin chloride increased eNOS mRNA
by 2.3- and 2.2-fold, respectively, implicating a role for H(2)O(2). Direct
addition of 100 and 150 micromol/L H(2)O(2) caused increases in bovine aortic
endothelial cell eNOS mRNA that were dependent on concentration (ie, 3.1- and 5.2
fold increases) and time, and elevated eNOS protein expression and enzyme
activity, accordingly. Nuclear run-on and 5, 6-dichloro-1-beta-D
ribofuranosylbenzimidazole-chase studies showed that H(2)O(2) caused a 3.0-fold
increase in eNOS gene transcription and a 2.8-fold increase in eNOS mRNA half
life. Induction of eNOS by H(2)O(2) was not affected by the hydroxyl radical
scavenger DMSO, mannitol, or N-tert-butyl-alpha-phenylnitrone, but it was
inhibited by the antioxidants N-acetylcysteine, ebselen, and exogenously added
catalase. Unlike H(2)O(2), the 4.0-fold induction of eNOS by shear stress (15
dyne/cm(2) for 6 hours) was not inhibited by N-acetylcysteine or exogenous
catalase. In conclusion, H(2)O(2) increases eNOS expression through
transcriptional and post-transcriptional mechanisms. Although H(2)O(2) does not
mediate shear-dependent eNOS regulation, it is likely to be involved in
regulation of eNOS expression in response to other physiological and/or
pathophysiological stimuli.
PMID- 10679489
TI - Interactions between Ca(2+) and H(+) and functional consequences in vascular
smooth muscle.
AB - Ca(2+) and H(+) ions can profoundly alter vascular tone. In many physiological
and pathological processes, changes in the concentration of both ions occur.
Thus, to understand the processes and mechanisms that modify force, it is
necessary to understand what changes occur in these ions and, importantly, how
they interact with each other. In this minireview, we highlight the
quantitatively important mechanisms involved in the contractile responses of
vascular tissues to pH change and discuss the cellular and molecular reasons
underlying these responses.
PMID- 10679490
TI - Regulation of endothelial nitric oxide synthase expression by albumin-derived
advanced glycosylation end products.
AB - We examined whether albumin-derived advanced glycosylation end products (AGEs)
downregulate the expression of endothelial nitric oxide synthase (NOS).
Significant reductions in NOS activity and cGMP levels in bovine aortic
endothelial cells were observed when exposed to different concentrations of
albumin-derived AGEs. Western and Northern blot analyses showed significant
decreases at the protein and transcript levels. Both reductions became evident
after 24 hours of exposure. Nuclear run-on assays showed that AGE-BSA did not
modify the transcription rate of the NOS III gene; however, AGE-BSA treatment
markedly reduced the half-life of NOS III mRNA. In addition, AGE-treated
endothelial cells displayed significant reduction on their antiplatelet
properties. These results indicate that NOS expression is reduced by AGEs by
increasing the rate of mRNA degradation and may be relevant to the impairment of
some endothelial functions observed in diabetes and aging. The full text of this
article is available at http://www.circresaha.org.
PMID- 10679491
TI - Possible mechanism(s) of arachidonic acid-induced intracellular acidosis in rat
cardiac myocytes.
AB - Arachidonic acid (AA) and other nonesterified fatty acids (FAs) have been shown
to exert harmful effects during cardiac ischemia. By continuously measuring
intracellular pH (pH(i)) changes in neonatal and adult cardiac myocytes, we have
found, for the first time, that 10 micromol/L AA induces a substantial
intracellular acidosis (0.3 to 0.4 pH units). We have ruled out the possibilities
that the AA-induced acidosis is caused by (1) inhibition or stimulation of the
pH(i) regulators, (2) protein kinase C activation or the generation of AA
metabolites or free radicals, or (3) activation of NADPH oxidase or an inward
H(+) current. The AA-induced acidosis fits to a simple diffusion mechanism, as
proposed by Kamp and Hamilton (flip-flop model) for artificial phospholipid
bilayers. The important properties found in the cardiac myocyte are that (1) the
initial rate of acid flux (J(H)) increases with the AA concentration (2 to 50
micromol/L), (2) FAs with a (-)COOH group (eg, AA, oleic acid, and linoleic acid)
induce intracellular acidification, but FAs with a (-)COOCH(3) group (eg, AA
methyl ester) have little effect on the pH(i), (3) tetradecylamine (FA amine)
induces intracellular alkalosis, and, most importantly, (4) both the AA- and
tetradecylamine-induced pH(i) changes can be reversed by 0.3% BSA. Because a low
concentration of AA (10 micromol/L) can induce a substantial acidosis, the
possible involvement of the FA-evoked acidosis in the negative inotropic effect
during cardiac ischemia is discussed. The full text of this article is available
at http://www. circresaha.org.
PMID- 10679492
TI - Online-only or Print? : An urgent request to readers and authors
PMID- 10679493
TI - e-hypertension : opening new vistas
PMID- 10679494
TI - Long-term absolute benefit of lowering blood pressure in hypertensive patients
according to the JNC VI risk stratification.
AB - Blood pressure (BP) levels alone have been traditionally used to make treatment
decisions in patients with hypertension. The sixth report of the Joint National
Committee on Prevention, Detection, Evaluation, and Treatment of High Blood
Pressure (JNC VI) recently recommended that risk strata, in addition to BP
levels, be considered in the treatment of hypertension. We estimated the absolute
benefit associated with a 12 mm Hg reduction in systolic BP over 10 years
according to the risk stratification system of JNC VI using data from the
National Health and Nutrition Examination Survey Epidemiologic Follow-up Study.
The number-needed-to-treat to prevent a cardiovascular event/death or a death
from all causes was reduced with increasing levels of baseline BP in each of the
risk strata. In addition, the number-needed-to-treat was much smaller in persons
with > or =1 additional major risk factor for cardiovascular disease (risk group
B) and in those with a history of cardiovascular disease or target organ damage
(risk group C) than in those without additional major risk factors for
cardiovascular disease (risk group A). Specifically, the number-needed-to-treat
to prevent a death from all causes in patients with a high-normal BP, stage 1
hypertension, or stage 2 or 3 hypertension was, respectively, 81, 60, and 23 for
those in risk group A; 19, 16, and 9 for those in risk group B; and 14, 12, and 9
for those in risk group C. Our analysis indicated that the absolute benefits of
antihypertensive therapy depended on BP as well as the presence or absence of
additional cardiovascular disease risk factors and the presence or absence of
preexisting clinical cardiovascular disease or target organ damage.
PMID- 10679495
TI - Long-term effects of weight loss and dietary sodium reduction on incidence of
hypertension.
AB - To examine the long-term effects of weight loss and dietary sodium reduction on
the incidence of hypertension, we studied 181 men and women who participated in
the Trials of Hypertension Prevention, phase 1, in Baltimore, Md. At baseline
(1987 to 1988), subjects were 30 to 54 years old and had a diastolic blood
pressure (BP) of 80 to 89 mm Hg and systolic BP <160 mm Hg. They were randomly
assigned to one of two 18-month lifestyle modification interventions aimed at
either weight loss or dietary sodium reduction or to a usual care control group.
At the posttrial follow-up (1994 to 1995), BP was measured by blinded observers
who used a random-zero sphygmomanometer. Incident hypertension was defined as
systolic BP > or =160 mm Hg and/or diastolic BP > or =90 mm Hg and/or treatment
with antihypertensive medication during follow-up. Body weight and urinary sodium
were not significantly different among the groups at the posttrial follow-up.
After 7 years of follow-up, the incidence of hypertension was 18.9% in the weight
loss group and 40.5% in its control group and 22.4% in the sodium reduction group
and 32.9% in its control group. In logistic regression analysis adjusted for
baseline age, gender, race, physical activity, alcohol consumption, education,
body weight, systolic BP, and urinary sodium excretion, the odds of hypertension
was reduced by 77% (odds ratio 0.23; 95% confidence interval 0.07 to 0.76;
P=0.02) in the weight loss group and by 35% (odds ratio 0.65; 95% confidence
interval 0.25 to 1.69; P=0.37) in the sodium reduction group compared with their
control groups. These results indicate that lifestyle modification such as weight
loss may be effective in long-term primary prevention of hypertension.
PMID- 10679496
TI - Regulation of sodium balance and blood pressure by the AT(1A) receptor for
angiotensin II.
AB - To examine the role of the angiotensin II (AT)(1A) receptor in the regulation of
blood pressure and sodium balance, we measured systolic blood pressure responses
in AT(1A) receptor-deficient (Agtr1a-/-) and wild-type (Agtr1a+/+) mice while
dietary sodium content was systematically altered. On a 0.4% sodium diet,
systolic blood pressures were significantly lower in Agtr1a-/- than in +/+ mice.
In Agtr1a+/+ mice, changing dietary sodium content did not affect blood pressure.
In contrast, when Agtr1a-/- mice were fed a high-salt diet (6% NaCl), their
systolic blood pressures increased significantly from 79+/-4 to 94+/-4 mm Hg
(P<0.006). The low blood pressures of Agtr1a-/- mice decreased further while on a
low-salt diet from 82+/-3 to 69+/-3 mm Hg (P<0.03). On the high-salt diet,
urinary sodium excretion increased to similar levels in Agtr1a+/+ and -/- mice.
Although urinary sodium excretion was substantially reduced in both groups during
the low-salt diet, cumulative sodium balances became negative in Agtr1a-/- mice
despite a 6-fold increase in urinary aldosterone. We infer, therefore, that the
reduced blood pressures in Agtr1a-/- mice on a normal diet are caused by
depletion of sodium and extracellular volume. Their "sodium sensitivity" suggests
a critical role for renal AT(1A) receptors to modulate sodium handling.
PMID- 10679497
TI - beta-2 adrenergic receptor gene variations, blood pressure, and heart size in
normal twins.
AB - Genetic variability, which influences cardiovascular phenotypes in normal
persons, is likely to be relevant to cardiovascular disease. We studied normal
monozygotic and dizygotic twins and found strong genetic influences on blood
pressure and heart size. We then relied on the dizygotic twins and their parents
to apply molecular genetic techniques. We performed a linkage analysis with
markers close to the beta-2 adrenergic receptor (AR) gene locus in the dizygotic
twins and their parents and found strong evidence for linkage to the quantitative
traits of blood pressure and heart size. We then used allele-specific polymerase
chain reaction to genotype the subjects further. We performed an association
analysis and found that 4 functionally relevant polymorphisms in the beta-2 AR
gene, namely Arg16/Gly, Gln27/Glu, Thr164/Ile, and a variant in the promoter
region (-47C/T), were variably associated with blood pressure and heart size
differences but were in linkage dysequilibrium with each other. A subsequent
conditional analysis suggested that the Arg16/Gly polymorphism exerted the
predominant effect. These findings underscore the importance of the beta-2 AR
gene to blood pressure regulation, heart size, and probably to the development of
hypertension. We suggest that a combined linkage and association approach will
elucidate the genetic variability influencing blood pressure and other
cardiovascular phenotypes.
PMID- 10679498
TI - Hypertension incidence is predicted by high levels of hopelessness in Finnish
men.
AB - Recent studies have reported that hopelessness is an important factor in
cardiovascular morbidity and mortality, including ischemic heart disease, acute
myocardial infarction, and atherosclerotic progression. This study examined the
relationship between hopelessness and incident hypertension in a population-based
sample of 616 initially normotensive, middle-aged men from eastern Finland, an
area with high rates of cardiovascular disease. Participants completed a medical
examination and a series of psychological questionnaires at baseline and at the 4
year follow-up. Hopelessness was measured by 2 items assessing negative
expectancy about the future and one's goals. A logistic regression model with
adjustments for age, body mass index, baseline resting blood pressure, physical
activity, smoking, alcohol consumption, education, parental history of
hypertension, and self-reported depressive symptoms revealed that men reporting
high levels of hopelessness at baseline were 3 times more likely to become
hypertensive (systolic blood pressure > or =165 mm Hg and/or a diastolic blood
pressure > or =95 mm Hg or confirmed use of antihypertensive medication) in the
intervening 4 years than men who were not hopeless (odds ratio, 3.22; 95%
confidence interval, 1. 56, 6.67). Men reporting moderate levels of hopelessness
were not at a significantly increased risk of hypertension (odds ratio, 1.27; 95%
confidence interval, 0.79, 2.07). This is the first study to identify a
significant relationship between hopelessness and incident hypertension. Research
is needed to explore the neuroendocrine and central nervous system mechanisms
underlying this association.
PMID- 10679499
TI - Contribution of autosomal loci and the Y chromosome to the stress response in
rats.
AB - Stress is a critical contributor to cardiovascular diseases through its impact on
blood pressure variability and cardiac function. Familial clustering of
reactivity to stress has been demonstrated in human subjects, and some rodent
models of hypertension are hyperresponsive to stress. Therefore, the present
study was designed to uncover the genetic determinants of the stress response. We
performed a total genome linkage search to identify the loci of the body
temperature response to immobilization stress in a set of recombinant inbred
strains (RIS) originating from reciprocal crosses of spontaneously hypertensive
rats (SHR) with a normotensive Brown Norway Lx strain. Two quantitative trait
loci (QTLs) were revealed on chromosomes (Chrs) 10 and 12 (logarithm of odds
scores, 2.2 and 1. 3, respectively). The effects of these QTLs were enhanced by a
high sodium diet (logarithm of odds scores, 4.0 and 3.3 for Chrs 10 and 12,
respectively), which is suggestive of a salt-sensitive component for the
phenotype. Congenics for Chr 10 confirmed both the QTL and the salt effect in
RIS. Negatively associated loci were also identified on Chrs 8 and 11.
Interaction between the loci of Chrs 10 and 12 was demonstrated, with the rat
strains bearing SHR alleles at both loci having the highest thermal response to
stress. Furthermore, the Y Chr of SHR origin enhanced the response to
immobilization stress, as demonstrated in 2 independent models, RIS and Y Chr
consomics. However, its full effect requires autosomes of the SHR strain. These
findings provide the first evidence for the genetic determination of reactivity
to stress with interactions between autosomal loci and between the Y and
autosomal Chrs that contribute to the explanation of the 46% of variance in the
stress response.
PMID- 10679500
TI - Heritability of central systolic pressure augmentation: a twin study.
AB - Less than 50% of the variance in left ventricular mass is explained by
conventional factors such as age, blood pressure, and body size. Genetic
influences may account for part of the unexplained variance. The central (aortic)
pressure augmentation index has been suggested as a noninvasive measure of
pulsatile load, which is a likely determinant of left ventricular mass. We
quantified the genetic influence on augmentation index and determined the extent
to which this influence is dependent on the effects of age, height, heart rate,
and blood pressure. We performed a classical twin study composed of 225
monozygotic and 594 dizygotic female white twin pairs aged 18 to 73 years.
Augmentation index and mean arterial pressure were based on the central pressure
wave derived from the radial waveform as measured by applanation tonometry.
Quantitative genetic modeling techniques were used to analyze the data. The
heritability of augmentation index was 37%, whereas heritabilities for blood
pressure traits varied between 13% and 25%. Most of the variance in augmentation
index could be explained by genetic and environmental factors specifically
influencing augmentation index. Only a relatively small part of the total
variance in augmentation index could be attributed to genes in common with height
(3.1%), heart rate (4.6%), and mean arterial pressure (5.6%). Age explained 19%
of the total variation in augmentation index. In conclusion, augmentation index
has a significant heritable component, which is largely independent of the
influence of blood pressure, heart rate, height, and age. Finding genes for the
augmentation index could help to unravel pathophysiological mechanisms causing
left ventricular hypertrophy and lead to improvements in prevention, diagnosis,
and treatment of at-risk populations.
PMID- 10679501
TI - Continuous relation between left ventricular mass and cardiovascular risk in
essential hypertension.
AB - The detection of left ventricular (LV) hypertrophy on echocardiography is a
powerful risk indicator in essential hypertension. However, the prognostic impact
of LV mass values within the "normal" range and the shape of the relation between
LV mass and prognosis remain unclear. Thus, 1925 white subjects with
uncomplicated essential hypertension underwent off-therapy 24-hour blood pressure
monitoring and M-mode echocardiography. During 4. 0+/-2 years of follow-up, there
were 181 major cardiovascular events (2.4/100 patient-years) and 49 deaths from
all causes. In the 5 gender-specific quintiles of LV mass distribution (partition
values: 92, 105, 120, and 138 g/m(2) in men and 79, 91, 102, and 116 g/m(2) in
women), cardiovascular event rates were 0.8, 1.7, 2.2, 2.9, and 4. 3 per 100
patient-years. After adjustment for several risk factors, including 24-hour
ambulatory blood pressure, the relative risk (RR) of developing a cardiovascular
event increased progressively from the first quintile (RR 1) to the second (RR
1.6, 95% CI 0.8 to 3.1), third (RR 1.9, 95% CI 1.01 to 4.0), fourth (RR 3.0, 95%
CI 1.5 to 5. 8), and fifth (RR 3.5, 95% CI 1.8 to 6.8) quintile. For all-cause
death, the RR in the fifth quintile compared with the first quintile was 4.3 (95%
CI 1.2 to 13.4). In conclusion, the powerful relation between LV mass and risk of
cardiovascular disease in subjects with uncomplicated essential hypertension is
continuous over a wide range of LV mass values, even below the current "upper
normal" limits. The relation remains significant after control for traditional
risk factors, including ambulatory blood pressure.
PMID- 10679502
TI - Blood pressure-independent effects in rats with human renin and angiotensinogen
genes.
AB - The blood pressure-independent effects of angiotensin II (Ang II) were examined
in double transgenic rats (dTGR) harboring human renin and human angiotensinogen
genes, in which the end-organ damage is due to the human components of the renin
angiotensin system. Triple-drug therapy (hydralazine 80 mg/L, reserpine 5 mg/L,
and hydrochlorothiazide 25 mg/L in drinking water) was started immediately after
weaning. Triple-drug therapy normalized blood pressure and coronary resistance,
only partially prevented cardiac hypertrophy, and had no effect on ratio of renal
weight to body weight. Although triple-drug therapy delayed the onset of renal
damage, severe albuminuria nevertheless occurred. Semiquantitative scoring of ED
1-positive and MIB-5-positive (nuclear cell proliferation-associated antigen Ki
67) cells showed profound perivascular monocyte/macrophage infiltration and cell
proliferation in kidneys and hearts of untreated dTGR. Triple-drug therapy had
only a minimal effect on local inflammatory response or vascular cell
proliferation. In contrast, a novel orally active human renin inhibitor (HRI), 30
mg/kg by gavage for 4 weeks, normalized blood pressure and coronary resistance
and also prevented cardiac hypertrophy and albuminuria. ED-1-positive cells and
MIB-5-positive cells were decreased by HRI in hearts and kidneys almost to levels
observed in normotensive Sprague-Dawley rats. The renoprotective effects of HRI
were at least in part due to improved renal hemodynamics and distal tubular
function, since HRI shifted renal pressure-diuresis/natriuresis curves leftward
by approximately 35 mm Hg, increased glomerular filtration rate and renal blood
flow, and shifted the fractional water and sodium excretion curves leftward. In
untreated dTGR, plasma Ang II was increased by 400% and renal Ang II level was
increased by 300% compared with Sprague-Dawley rats. HRI decreased plasma human
renin activity by 95% and normalized Ang II levels in both plasma and kidney
compared with triple-drug therapy. Our findings indicate that in dTGR harboring
human renin and angiotensinogen genes, Ang II causes end-organ damage and
promotes inflammatory response and cellular growth largely independent of blood
pressure.
PMID- 10679503
TI - Gene transfer of endothelial nitric oxide synthase reduces angiotensin II-induced
endothelial dysfunction.
AB - Angiotensin II stimulates vascular NADPH oxidase to produce superoxide, which can
react with nitric oxide and impair vasomotor function. We tested the hypothesis
that the overexpression of endothelial nitric oxide synthase (eNOS) or superoxide
dismutase (SOD) would correct angiotensin II-induced endothelial dysfunction. We
examined the effects of the gene transfer of eNOS or 2 isoforms of SOD to the
aorta in angiotensin II-treated rabbits on vasomotor function. New Zealand White
rabbits were treated for 1 week with angiotensin II (100 ng. kg(-1). min(-1)) or
saline by osmotic minipumps. In angiotensin II-treated rabbits, mean blood
pressure was 107+/-8 mm Hg; it was 67+/-5 mm Hg in saline-infused rabbits
(P<0.05). In aortas from angiotensin II-treated rabbits, lucigenin-enhanced
chemiluminescence demonstrated a 2.5-fold increase in superoxide levels, and the
oxidative fluorescent probe hydroethidine indicated increased superoxide levels
throughout the vascular wall, especially in the endothelium and adventitia.
Maximal relaxation to acetylcholine was less in aortas from rabbits treated with
angiotensin II (72+/-5% versus 87+/-4% in saline-treated rabbits; P<0.01), but
responses to sodium nitroprusside were similar. Segments of the thoracic aorta
were incubated in vitro with an adenoviral vector that expressed eNOS, copper
zinc SOD (CuZnSOD), extracellular SOD (ECSOD), or beta-galactosidase. beta-Gal
treatment with adenovirus containing the gene for eNOS (AdeNOS) but not
adenovirus containing the gene for beta-gal (Adbeta-gal) (control virus) restored
responses to acetylcholine (82+/-3% after AdeNOS and 67+/-4% after Adbeta-gal).
Gene transfer of CuZnSOD or ECSOD did not improve the endothelium-dependent
relaxation of the aorta in rabbits that received angiotensin II. Thus, gene
transfer of eNOS, but not SOD, effectively restores vasomotor function in
angiotensin II-infused rabbits.
PMID- 10679504
TI - Vasopressin does not effect hypertension caused by long-term nitric oxide
inhibition.
AB - Nitric oxide attenuates both vasopressin-induced vasoconstriction and vasopressin
release. We tested whether hypertension and renal dysfunction elicited by chronic
inhibition of nitric oxide (NO) synthesis using N(G)-nitro-L-arginine (L-NNA)
could be mediated in part by vasopressin V(1A) receptors. Male rats were treated
orally for 6 weeks with L-NNA (15 mg/kg per day), a nonpeptide V(1A) receptor
antagonist (2S)-1-[(2R,3S)-5-chloro-3-(2-chlorophenyl)-1-(3, 4-dimethoxybenzene
sulfonyl)-3-hydroxy-2, 3-dihydro-1H-indole-2-carbonyl]-pyrrolidine-2-carboxamide
(SR 49059, 30 mg/kg per day), or a combination of SR 49059 and L-NNA (same
doses), or they received no treatment. Both drugs were added to the food.
Measurements were performed in conscious rats (urine collection in metabolic
cages, tail-cuff arterial pressure) and at the end of the study in anesthetized
rats (clearance measurements). L-NNA produced sustained hypertension, decreased
glomerular filtration rate, and increased renal vascular resistance, plasma renin
activity, and urinary albumin excretion. SR 49059 had no effect per se on these
parameters and also did not attenuate the hypertension and renal dysfunction
induced by L-NNA. Surprisingly, SR 49059 potentiated L-NNA-induced hypertension
at the end of the 6-week treatment. However, the blood pressure response and the
renal and mesenteric vasoconstriction elicited by exogenous vasopressin were
attenuated in rats treated with SR 49059. L-NNA did not change plasma vasopressin
concentration or 24-hour urinary vasopressin excretion. Our findings suggest that
activation of vasopressin V(1A) receptors does not contribute to the hypertension
and renal dysfunction induced by chronic NO synthesis inhibition. They also
document unchanged plasma vasopressin concentration in NO-deficient hypertension.
PMID- 10679505
TI - Role of alpha(2)-adrenergic receptor subtypes in the acute hypertensive response
to hypertonic saline infusion in anephric mice.
AB - Experimental evidence suggests that the acute hypertensive response induced in
anephric animals by infusion of a hypertonic saline solution is mediated by
disinhibition of the presynaptic sympathoinhibitory alpha(2)-adrenergic receptors
(alpha(2)-AR) of the central nervous system. The purpose of the present
experiments was to dissect the role of the 3 distinct alpha(2)-AR subtypes
(alpha(2A)-, alpha(2B), - and alpha(2C)-AR) in this response. Groups of
genetically engineered mice deficient in each one of these alpha(2)-AR subtype
genes were submitted to bilateral nephrectomy followed by a 0.4-mL infusion of 4%
saline over a 2-hour period, with constant direct blood pressure (BP) monitoring.
The alpha(2A)-AR-deficient and alpha(2C)-AR-deficient mice responded with
significant BP elevations (by 11.8+/-2.5 and 16.7+/-1.7 mm Hg, respectively), and
so did their wild-type counterparts (17.8+/-2.5 and 11.8+/-2.0 mm Hg,
respectively) and the wild-type alpha(2B) +/+ (13.1+/-2.4 mm Hg). However, the
alpha(2B)-AR-deficient mice were unable to raise their BP and had a slightly
lowered BP (by -3.0+/-4. 0 mm Hg) at the end of the infusion period. All 6 groups
exhibited elevated plasma norepinephrine levels ranging between 0.8 and 1.8 ng/mL
at the end of the infusion. In all cases, the alpha(2)-AR-deficient groups tended
to have higher norepinephrine levels than their wild-type counterparts.
Surprisingly, this difference was significant only in the alpha(2B)-AR-deficient
mice, which, despite the elevated norepinephrine, were unable to raise their BP.
The data suggest that a full complement of the alpha(2B)-AR is needed to mediate
the hypertensive response to acute saline load, even though its absence does not
prevent the release of norepinephrine under these conditions.
PMID- 10679506
TI - Attenuation of the "white-coat effect" by antihypertensive treatment and
regression of target organ damage.
AB - This study assessed whether 2 common surrogate measures of the "white-coat
effect," namely the clinic-daytime and the clinic-home differences in blood
pressure (BP), were attenuated by long-term antihypertensive treatment and
whether this attenuation is relevant to the treatment-induced regression of left
ventricular hypertrophy, thus having clinical significance. We considered data
from 206 patients with essential hypertension (aged 20 to 65 years) who had a
diastolic BP between 95 and 115 mm Hg and echocardiographic evidence of left
ventricular hypertrophy. In each patient, clinic BP, 24-hour ambulatory BP, and
left ventricular mass index were assessed at baseline, after 3 and 12 months of
treatment with an angiotensin-converting enzyme inhibitor, and after a final 4
week placebo run-off period. At baseline, the clinic-daytime differences in
systolic and diastolic BP were 12.1+/-15.4 and 6.8+/-10.1 mm Hg, respectively;
the corresponding values for the clinic-home differences were 5.7+/-10.6 and
2.9+/-6.1 mm Hg, respectively. These differences were reduced by 57.6% and 77.1%
(P<0.01) and by 65.7% and 64.3% (P<0.01), respectively, after 12 months of
treatment, with a partial return toward the pretreatment differences after the
final placebo period. The observed treatment-induced reductions in left
ventricular mass index and those in the clinic-daytime or clinic-home differences
for systolic and diastolic BP showed no significant relationship when tested by
multiple regression analysis. This provides the first longitudinal evidence that
clinic-daytime and clinic-home differences in BP have no substantial value in
predicting the regression of target organ damage, such as left ventricular
hypertrophy, that has prognostic relevance.
PMID- 10679507
TI - Amlodipine, enalapril, and dependent leg edema in essential hypertension.
AB - Calcium channel blockers (CCBs) blunt postural skin vasoconstriction, an
autoregulatory mechanism that minimizes gravitational increases in capillary
pressure and avoids fluid extravasation when standing. To evaluate the dose
response relation between this pharmacological interference and dependent edema,
a frequent side effect of CCBs during antihypertensive treatment, skin blood flow
(laser Doppler flowmetry) at the dorsum of the foot, both supine and with the
limb passively placed 50 cm below the heart level, and leg weight (Archimedes
principle) were measured at baseline, during increasing doses of the
dihydropyridine amlodipine (5 and 10 mg UID each for 2 weeks), and after drug
withdrawal in 10 hypertensive men. Because angiotensin-converting enzyme
inhibitors may attenuate ankle swelling by CCBs, those parameters were evaluated
according to a similar design during amlodipine (10 mg UID) and enalapril (20 mg
UID) combined (n=10). As a control, the effect of enalapril monotherapy (10 and
20 mg UID for 2 weeks each) was evaluated in a third series of patients (n=8).
Amlodipine (5 mg UID) increased leg weight without modifying postural
vasoconstriction (the percent skin blood flow decrease from horizontal to
dependent position), which indicates that extravascular fluid shift was
independent of postural skin vasoconstriction. At 10 mg UID, however, amlodipine
blunted postural vasoconstriction and increased leg weight further, which
suggests that skin blood flow autoregulation limited additional fluid transfer.
Both parameters normalized after drug withdrawal. Enalapril per se did not affect
cutaneous vasomotion or leg weight but reduced the amount of dependent fluid
extravasation by the CCB despite a persistent antagonism for postural
vasoconstrictor responses.
PMID- 10679508
TI - A novel stable inhibitor of endopeptidases EC 3.4.24.15 and 3.4.24.16 potentiates
bradykinin-induced hypotension.
AB - We have developed a novel inhibitor of the metalloendopeptidases EC 3.4.24.15
(EP24.15) and EC 3.4.24.16 (EP24.16), N-[1-(R, S)-carboxy-3-phenylpropyl]-Ala-Aib
Tyr-p-aminobenzoate (JA2), in which alpha-aminoisobutyric acid (Aib) is
substituted for an alanine in a well-described but unstable inhibitor, cFP-AAY
pAB. This substitution increases the resistance of the inhibitor to degradation
without altering potency. In the present study, we investigated the effects of
JA2 (5 mg/kg) on the responses of mean arterial pressure to bradykinin,
angiotensin I, and angiotensin II in conscious rabbits. The depressor responses
to both low (10 ng/kg) and high (100 ng/kg) doses of bradykinin were increased
7.0+/-2. 7-fold and 1.5+/-0.3-fold, respectively, during the 30 minutes after JA2
administration (mean+/-SEM, n=8). Bradykinin potentiation was undiminished 4
hours after JA2 injection. In contrast, the hypertensive effects of angiotensins
I and II were unaltered, indicating that the bradykinin-potentiating effects were
not due to angiotensin-converting enzyme inhibition. These data suggest that JA2
is not only a potent and specific inhibitor of EP24.15 and EP24. 16 but is also
stable in vivo. Furthermore, the potentiation of bradykinin-induced hypotension
by JA2 suggests for the first time a role for one or both of these peptidases in
the metabolism of bradykinin in the circulation.
PMID- 10679509
TI - Sympathoinhibition by central and peripheral infusion of nifedipine in
spontaneously hypertensive rats.
AB - The present study assessed whether central mechanisms may contribute to the
hypotensive effect of the calcium channel blocker nifedipine. In conscious,
spontaneously hypertensive rats (SHR) on a high-salt diet, hemodynamic (mean
arterial pressure [MAP] and heart rate) and sympathetic (renal sympathetic nerve
activity) responses to low, central, intracerebroventricular infusion rates (25
microg. kg(-1). h(-1) for 2 hours) and peripheral intravenous rates (50 microg.
kg(-1). h(-1) for 3 hours and then 100 microg. kg(-1). h(-1) for 2 hours) of
nifedipine were evaluated. The distribution of nifedipine in the blood and
tissues was assessed at the end of the infusions. Nifedipine significantly
inhibited renal sympathetic nerve activity and lowered MAP in SHR beginning 30
minutes after the start of the intracerebroventricular infusion. The decrease of
MAP by intravenous infusion began at 60 minutes and was more profound with 100
microg. kg(-1). h(-1). Inhibition of sympathetic activity preceded and then
paralleled the decrease in blood pressure; it occurred earlier with central (15
to 30 minutes) than with peripheral (30 to 60 minutes) infusion. Intravenous
infusion resulted in concentrations of nifedipine in brain structures (brain
stem, midbrain, and cortex) that were 30% to 40% of those in the heart, kidneys,
and liver. From the hemodynamic and sympathetic responses and the distribution of
nifedipine into the central nervous system, we conclude that the peripheral
infusion of nifedipine at relatively low rates may evoke a hypotensive response
in SHR, not only via peripheral mechanisms, but also through central mechanisms,
which will lead to an inhibition of sympathetic outflow and, therefore, a
lowering of blood pressure.
PMID- 10679510
TI - Effect of age on brachial artery wall properties differs from the aorta and is
gender dependent: a population study.
AB - Compliance and distensibility are wall properties of large arteries, which may
play a role in cardiovascular disease. The purpose of this study was to
investigate whether the influence of age on these vessel wall properties differs
between vascular territories and is gender-dependent. In a population sample of
498 men and women 20 to 79 years of age, diameter, distensibility, and compliance
coefficient of the muscular brachial artery were measured with an echo-tracking
device. Distensibility of the aorta was measured with the use of pulse-wave
velocity. The effects of age and gender were assessed and adjusted for
confounding factors such as mean blood pressure, pulse rate, body mass index,
smoking, alcohol intake, and antihypertensive treatment. Covariance analysis
showed no relation between gender and distensibility of the elastic aorta.
Distensibility of the muscular brachial artery was lower in men, whereas men had
a larger diameter and larger compliance of the brachial artery. With age,
distensibility of the aorta decreased in both sexes to the same extent, whereas
distensibility of the brachial artery did not change significantly. With age,
brachial artery diameter increased; this increase was more pronounced in women.
In men brachial artery compliance did not change with age, whereas in women
compliance of the brachial artery increased with age. This study (1) confirms
that distensibility of the aorta, an elastic artery, decreases with age. (2) In
contrast to the aorta, after adjustment for confounding factors, in both men and
women, no relation exists between age and distensibility of the muscular brachial
artery. (3) Brachial artery diameter increase with age is more pronounced in
women than in men. (4) In contrast to the well-known decrease in arterial
compliance of elastic arteries with age, brachial artery compliance is not
decreased with age and is increased in women. In conclusion, the effect of age on
large-artery wall properties is not uniform but depends on gender and vascular
territory.
PMID- 10679511
TI - Age-related changes in renal cyclic nucleotides and eicosanoids in response to
sodium intake.
AB - The signaling molecules cGMP, cAMP, prostaglandin E(2) (PGE(2)), and
prostaglandin F(2alpha) (PGF(2alpha)) play important roles in mediating the
response of the kidney to changes in dietary sodium intake. We used a renal
microdialysis technique in conscious rats to address the hypothesis that the
renal ability to produce these mediators in response to dietary sodium intake is
altered during maturation. Young (4-week-old) or adult (6-month-old) rats were
studied after the consumption for 5 days of diets containing low (0. 04% NaCl),
normal (0.28% NaCl), or high (4.0% NaCl) levels of sodium. Plasma renin activity
was significantly increased by low-sodium diet and significantly decreased by
high-sodium diet, with no significant difference between the responses of the 2
age groups. Renal interstitial fluid (RIF) levels of cGMP, cAMP, PGE(2), and
PGF(2alpha) on normal-sodium diet were similar in the 2 age groups. Low-sodium
diet caused a significant increase in RIF levels of all 4 mediators, with no
significant differences between the responses of the 2 age groups. High-sodium
diet also caused a significant increase in RIF levels of all 4 mediators.
However, RIF production of cGMP, cAMP, and PGE(2) was significantly greater, and
RIF PGF(2alpha) production was significantly lower, in young rats compared with
adult rats. These data demonstrate that the kidneys of young and adult rats
respond to dietary sodium restriction in a similar manner but that there are age
related changes in the renal response to sodium loading.
PMID- 10679512
TI - Elevated perfusion pressure upregulates endothelin-1 and endothelin B receptor
expression in the rabbit carotid artery.
AB - To investigate the hypothesis that high blood pressure activates the endothelin
system in the vessel wall, isolated segments of the rabbit carotid artery were
subjected to different levels of perfusion pressure. Both preproendothelin-1
(ppET-1) mRNA abundance and intravascular ET-1 peptide content were strongly
upregulated on raising the intraluminal pressure from 90 to 160 mm Hg for 3 to 12
hours, and this increase in ppET-1 mRNA occurred predominantly in the endothelial
cells. Endothelin-converting enzyme-1 and endothelin A receptor (ET(A)-R)
expression were pressure-insensitive, whereas that of the ET(B)-R in the smooth
muscle cells was also significantly enhanced. Both the pressure-induced increase
in ppET-1 and ET(B)-R expression required RNA synthesis because they were
abolished by actinomycin D. The nuclear signaling mechanisms involved therein,
however, appeared to be different. Thus, the pressure-induced expression of ppET
1 and activation of CCAAT-enhancer binding proteins beta and delta were blocked
by the tyrosine kinase inhibitor herbimycin A, whereas ET(B)-R expression and the
nuclear translocation of activator protein-1 were abolished by the protein kinase
C inhibitor Ro 31-8220. One consequence of these presumably deformation-induced
changes in gene expression was an increased rate of apoptosis of the smooth
muscle cells in the media that if transferable to the situation in human blood
vessels may contribute to hypertension-induced arterial remodeling.
PMID- 10679513
TI - Effects of systemic inhibition of neuronal nitric oxide synthase in diabetic
rats.
AB - Diabetes is associated with alterations in nitric oxide-mediated vasomotor
function. The role of nitric oxide generated via the neuronal nitric oxide
synthase pathway in the control of systemic and renal hemodynamics in diabetes
has not been studied. To explore the hypothesis that diabetic vascular
dysfunction is in part caused by altered neuronal nitric oxide synthase activity,
systemic and renal hemodynamics were assessed before and after acute inhibition
of this enzyme with a specific inhibitor, S-methyl-L-thiocitrulline, in control
and diabetic rats. The interaction of this pathway and the renin-angiotensin
system was studied in separate groups of rats pretreated with the angiotensin II
receptor blocker losartan; these rats were compared with rats treated with
losartan alone. Diabetic animals demonstrated higher baseline glomerular
filtration rates and filtration fractions. At a low dose, the neuronal nitric
oxide synthase inhibitor induced similar dose-dependent pressor responses in
control and diabetic rats. Losartan abolished the pressor response in both
groups. No changes in renal plasma flow or renal vascular resistance occurred in
control rats. In contrast, diabetic rats responded with significant renal
vasoconstriction. At a high dose, the renal vasoconstriction was similar in both
groups and was not affected by losartan. In conclusion, neuronal nitric oxide
synthase-derived nitric oxide plays a role in the control of systemic and renal
hemodynamics in normal and diabetic rats. Diabetic rats are more sensitive to the
inhibitor, suggesting increased activity of this pathway in the diabetic kidney.
Furthermore, renal responses in diabetic rats were attenuated by angiotensin II
receptor blockade, whereas losartan alone induced hemodynamic changes that were
opposite those seen with neuronal nitric oxide synthase inhibition. This
observation implicates angiotensin II as an important modulator of this nitric
oxide pathway in diabetes.
PMID- 10679514
TI - Blood pressure is related to placental volume and birth weight.
AB - The objective of this study was to determine whether maternal nutrition and fetal
and placental size program blood pressure. A longitudinal study linking the
maternal anthropometric measurements of the first antenatal visit, ultrasound
data of placental and fetal size, anthropometry at birth, and childhood growth
and blood pressure was performed. The subjects were 428 women who attended the
antenatal clinic at the University Hospital of the West Indies, Kingston,
Jamaica, and their children, who were subsequently followed up. Systolic blood
pressure at ages 1, 2, 2.5, 3, and 3.5 years was the main outcome measure.
Pooling the data across ages, systolic blood pressure fell by 1.4 mm Hg for every
1-kg increase in birth weight (95% CI 0.2 to 2.7, P=0.02) and by 1.2 mm Hg for
every 100-mL increase in placental volume at 20 weeks of gestation (95% CI 0.4 to
2.0, P=0.004). Blood pressure was also negatively associated with placental
volume at 17 weeks and fetal abdominal circumference at 20 weeks. Measures of
maternal nutritional status were strongly related to birth weight and placental
volume but not directly to childhood blood pressure at these young ages. In
conclusion, blood pressure is associated with fetal size in this population, as
previously described among Europeans. We found associations between placental
volume and abdominal circumference in the second trimester and childhood blood
pressure, suggesting that the initiating events of blood pressure programming
occur early in pregnancy. Measures of maternal nutritional status were not
directly related to childhood blood pressure at these young ages but were strong
predictors of both birth weight and placental volume, suggesting an indirect
relation.
PMID- 10679515
TI - Glucocorticoid-remediable aldosteronism and pregnancy.
AB - Glucocorticoid-remediable aldosteronism (GRA) is a hereditary form of primary
hyperaldosteronism that presents with hypokalemia and hypertension from childhood
onward. GRA is characterized by the ectopic production of aldosterone in the
cortisol-producing zona fasciculata under the regulation of adrenocorticotrophic
hormone. Despite the early age of onset, no previous reports of pregnancy and GRA
exist. Therefore, we set out to describe the maternal and fetal outcomes of
pregnancy in women with GRA. Data regarding the blood pressure and pregnancy
outcomes were collected in a retrospective chart review of prenatal and hospital
records of 35 pregnancies in 16 women with genetically proven GRA. A total of 6%
of pregnancies in women with GRA (GRA+) were complicated by preeclampsia. The
published rates of preeclampsia in general obstetric populations vary from 2.5%
to 10%. Despite the lack of an apparent increase in the rate of preeclampsia,
GRA+ women with chronic hypertension had a high rate (39%) of pregnancy
aggravated hypertension. Starting with a higher baseline blood pressure, maternal
blood pressure plotted over the time course of pregnancy followed a quadratic
curve similar to that previously described in normal pregnancy. Mean gestational
age at delivery was 39.1 weeks. Mean birth weight, excluding the 3 sets of twins,
was 3219 g. However, infants of GRA+ mothers with pregnancy-aggravated
hypertension tended to have lower birth weights than those that did not (3019 g
versus 3385 g, respectively; P=0.08). The primary cesarean section rate was 32%,
which is approximately double that seen in other general or hypertensive
obstetric populations. In summary, GRA+ women did not seem to have an increased
risk of preeclampsia. However, GRA+ women with chronic hypertension seem to be at
an increased risk for an exacerbation of their hypertension during pregnancy.
PMID- 10679516
TI - p38 MAP kinase is required for vasopressin-stimulated HSP27 induction in aortic
smooth muscle cells.
AB - We previously showed that arginine vasopressin (AVP) stimulates heat shock
protein 27 (HSP27) induction through protein kinase C activation in aortic smooth
muscle A10 cells. In the present study, we examined whether the mitogen-activated
protein (MAP) kinase superfamily is involved in the AVP-stimulated HSP27
induction in A10 cells. AVP stimulated the phosphorylation of p42/p44 MAP kinase
and p38 MAP kinase. On the contrary, AVP had little effect on SAPK (stress
activated protein kinase)/JNK (c-Jun N-terminal kinase) phosphorylation. The
HSP27 accumulation by AVP was not affected by PD98059, an inhibitor of the
upstream kinase that activates p42/p44 MAP kinase. SB203580 and PD169316,
specific inhibitors of p38 MAP kinase, suppressed the AVP-induced accumulation of
HSP27. 12-O-tetradecanoylphorbol 13-acetate, an activator of protein kinase C,
induced accumulation of HSP27 and was not inhibited by PD98059 but was inhibited
by SB203580. Calphostin C and ET-18-OCH(3), inhibitors of protein kinase C,
reduced the phosphorylation of p38 MAP kinase by AVP. SB203580 and PD169316
suppressed the AVP-increased levels in mRNA for HSP27. Dissociation of the
aggregated HSP27 to the dissociated HSP27 was induced by AVP. These results
strongly suggest that p38 MAP kinase takes part in the pathway of the AVP
stimulated induction of HSP27 in vascular smooth muscle cells.
PMID- 10679517
TI - Cardiovascular effects of 2-arachidonoyl glycerol in anesthetized mice.
AB - Cannabinoids, including the endogenous ligand anandamide, elicit pronounced
hypotension and bradycardia through the activation of CB1 cannabinoid receptors.
A second endogenous cannabinoid, 2-arachidonoyl glycerol (2-AG), has been
proposed to be the natural ligand of CB1 receptors. In the present study, we
examined the effects of 2-AG on mean arterial pressure and heart rate in
anesthetized mice and assessed the role of CB1 receptors through the use of
selective cannabinoid receptor antagonists and CB1 receptor knockout (CB1(-/-))
mice. In control ICR mice, intravenous injections of 2-AG or its isomer 1-AG
elicit dose-dependent hypotension and moderate tachycardia that are unaffected by
the CB1 receptor antagonist SR141716A. The same dose of SR141716A (6 nmol/g IV)
completely blocks the hypotensive effect and attenuates the bradycardic effect of
anandamide. 2-AG elicits a similar hypotensive effect, resistant to blockade by
either SR141716A or the CB2 antagonist SR144528, in both CB1(-/-) mice and their
homozygous (CB1(+/+)) control littermates. In ICR mice, arachidonic acid (AA, 15
nmol/g IV) elicits hypotension and tachycardia, and indomethacin (14 nmol/g IV)
inhibits the hypotensive effect of both AA and 2-AG. Synthetic 2-AG incubated
with mouse blood is rapidly (<2 minutes) and completely degraded with the
parallel appearance of AA, whereas anandamide is stable under the same
conditions. A metabolically stable ether analogue of 2-AG causes prolonged
hypotension and bradycardia in ICR mice, and both effects are completely blocked
by SR141716A, whereas the same dose of 2-AG-ether does not influence blood
pressure and heart rate in CB1(-/-) mice. These findings are interpreted to
indicate that exogenous 2-AG is rapidly degraded in mouse blood, probably by a
lipase, which masks its ability to interact with CB1 receptors. Although the
observed cardiovascular effects of 2-AG probably are produced by an arachidonate
metabolite through a noncannabinoid mechanism, the CB1 receptor-mediated
cardiovascular effects of a stable analogue of 2-AG leaves open the possibility
that endogenous 2-AG may elicit cardiovascular effects through CB1 receptors.
PMID- 10679518
TI - Vascular response to angiotensin II in atherosclerosis: role of the baroreflex.
AB - High-cholesterol alimentation is associated with an induction of angiotensin
converting enzyme and angiotensin II receptor expression within the vascular wall
of the aorta. Despite an enhanced pressure response to angiotensin II in
atherosclerotic conscious rabbits, angiotensin II-induced contraction was reduced
in isolated vascular rings from the aorta and unchanged in those from the iliac
artery. We, therefore, investigated whether cholesterol-induced atherosclerosis
enhances overall vascular responsiveness to angiotensin II in intact animals and
whether an altered arterial baroreflex sensitivity can explain the discrepancy
between experiments in intact animals and isolated blood vessels. Rabbits were
maintained on a high-cholesterol diet (2 g/d cholesterol plus 20 mL/d sunflower
seed oil, n=11) or on a standard diet (n=12) for 12 weeks. Total serum lipids
markedly increased (P<0.05). Tissue examinations 6 weeks after termination of the
high-cholesterol diet revealed distinct atherosclerosis and elevated cholesterol
content in the aorta (P<0.05). A high-cholesterol diet did not change baseline
hemodynamic parameters. However, angiotensin II-induced increases in total
peripheral resistance were larger in the atherosclerotic animals (86.3+/-13.0
versus 41.9+/-9.7 mm Hg. L(-1). min, P<0.05). In addition, the blood pressure
pulse interval relationship was markedly reduced (slope: 0.80+/-0.14 versus 0.
49+/-0.06 ms/mm Hg, P<0.05), which suggested that the baroreflex blunted the
angiotensin II response to a lesser extent in atherosclerotic animals. In
conclusion, the overall vascular responsiveness to angiotensin II is increased in
the atherosclerotic rabbit as indicated by the larger increase in total
peripheral resistance. An attenuation of the arterial baroreflex sensitivity may
contribute to this effect.
PMID- 10679519
TI - Hypertension online only : february 2000
PMID- 10679520
TI - Long-term telemetric recording of arterial pressure and heart rate in mice fed
basal and high NaCl diets.
AB - Research examining the control of arterial pressure in mice has primarily relied
on tail-cuff plethysmography and, more recently, on tethered arterial catheters.
In contrast, the radiotelemetry method has largely become the "gold standard" for
long-term monitoring of arterial pressure and heart rate in rats. Whereas smaller
telemetry probes have recently been developed, no published studies have used
radiotelemetric monitoring of arterial pressure in mice, largely because of a
relatively low success rate in small mice (ie, <30 g body weight). We report on
the development of a protocol for the use of these probes to continuously monitor
arterial pressure and heart rate in mice as small as 19 g body weight. To test
the accuracy and reliability of this method, adult C57/BL6 mice were monitored
for 3 weeks during exposure to a basal followed by a high NaCl diet. The results
demonstrate that carotid and aortic placements of the telemetry probe provide
equally accurate monitoring of arterial pressure and heart rate, but the carotid
placement has a much greater rate of success. Exposure to a high NaCl diet
increases both the amplitude of the arterial pressure rhythm (+ 6.0+/-0.6 mm Hg,
approximately 32%) and the average mean arterial pressure (+ 8.6+/-1.1 mm Hg,
approximately 8%), as would be predicted from previous studies in NaCl-resistant
rats. Thus, the data demonstrate that telemetric recording of long-term arterial
pressure and heart rate provides a powerful tool with which to define the
mechanisms of cardiovascular control in mice.
PMID- 10679521
TI - Heart rate variability: how to assess effects of mild therapies on autonomic
control in small groups of mild and borderline hypertensives?
PMID- 10679522
TI - Stability of the molten globule state of a domain-exchanged chimeric protein
between human and bovine alpha-lactalbumins.
AB - A domain-exchanged chimeric alpha-lactalbumin (alpha-LA), which consisted of the
alpha-domain of human alpha-LA and the beta-domain of bovine alpha-LA, was
constructed. Like native alpha-LA, the chimeric protein was in a molten globule
state in the absence of Ca(2+) at neutral pH and low salt concentration. The
stability of the molten globule state of the constructed chimeric protein was
identical to that of the recombinant human protein and was higher than that of
the recombinant bovine protein. The stability of the molten globule state of
alpha-LA is defined by the stability of the alpha-domain.
PMID- 10679523
TI - Production of an activated form of Bacillus stearothermophilus L-2-hydroxyacid
dehydrogenase by directed evolution.
AB - Bacillus stearothermophillus lactate dehydrogenase (bsLDH) is activated in the
presence of fructose 1,6 bisphosphate (FBP). The activator is expensive and
representative of the sort of co-factor complications that are undesirable in
industrial processes. Three rounds of random mutagenesis and screening produced a
mutant (6A) which is almost fully activated in the absence of FBP. Wild-type
bsLDH has a K(pyr)(M) of 5 mM in the absence of FBP but when activated (+FBP) the
K(pyr)(M) drops to 0.05 mM. The mutant 6A has a K(pyr)(M) of 0.07 mM in the
absence of FBP. 6A has three amino acid substitutions-R118C, Q203L and N307S
resulting in a 70-fold activation, none of the mutations are near the active
site. The activation of wild type bsLDH is due to an FBP induced tetramerization
of dimeric bsLDH bringing about a structural rearrangement of key active site
residues. The most likely explanation for the activation of 6A is derived from
the position of Q203L, which is at the dimer-dimer interface. The suggestion is
that the hydrophilic to hydrophobic change has altered the dimer-tetramer
equilibrium position towards that of the tetramer. What is significant is the
activation of bsLDH by a subtle long range event produced by the 'blind' directed
evolution approach.
PMID- 10679524
TI - Protein thermal stability: insights from atomic displacement parameters (B
values).
AB - The factors contributing to the thermal stability of proteins from thermophilic
origins are matters of intense debate and investigation. Thermophilic proteins
are thought to possess better packed interiors than their mesophilic
counterparts, leading to lesser overall flexibility and a corresponding reduction
in surface-to-volume ratio. These observations prompted an analysis of B values
reported in high-resolution X-ray crystal structures of mesophilic and
thermophilic proteins. In this analysis, the following aspects were addressed:
(1) frequency distribution of normalized B values (B' factors) over all the
proteins and for individual amino acids; (2) amino acid compositions in high B
value regions of polypeptide chains; (3) variation in the B values from core to
the surface of proteins in terms of their radius of gyration; and (4) degree of
dispersion of normalized B values in spheres around the Calpha atoms. The
analysis revealed that (1) Ser and Thr have lesser flexibility in thermophiles
than in mesophiles, (2) the proportion of Glu and Lys in high B value regions of
thermophiles is higher and that of Ser and Thr is lower and (3) the dispersion of
B values within spheres at Calpha atoms is similar in mesophiles and
thermophiles. These observations reflect plausible differences in the dynamics of
thermophilic and mesophilic proteins and suggest amino acid substitutions that
are likely to change thermal stability.
PMID- 10679525
TI - Is it better to combine predictions?
AB - We have compared the accuracy of the individual protein secondary structure
prediction methods: PHD, DSC, NNSSP and Predator against the accuracy obtained by
combing the predictions of the methods. A range of ways of combing predictions
were tested: voting, biased voting, linear discrimination, neural networks and
decision trees. The combined methods that involve 'learning' (the non-voting
methods) were trained using a set of 496 non-homologous domains; this dataset was
biased as some of the secondary structure prediction methods had used them for
training. We used two independent test sets to compare predictions: the first
consisted of 17 non-homologous domains from CASP3 (Third Community Wide
Experiment on the Critical Assessment of Techniques for Protein Structure
Prediction); the second set consisted of 405 domains that were selected in the
same way as the training set, and were non-homologous to each other and the
training set. On both test datasets the most accurate individual method was
NNSSP, then PHD, DSC and the least accurate was Predator; however, it was not
possible to conclusively show a significant difference between the individual
methods. Comparing the accuracy of the single methods with that obtained by
combing predictions it was found that it was better to use a combination of
predictions. On both test datasets it was possible to obtain a approximately 3%
improvement in accuracy by combing predictions. In most cases the combined
methods were statistically significantly better (at P = 0.05 on the CASP3 test
set, and P = 0.01 on the EBI test set). On the CASP3 test dataset there was no
significant difference in accuracy between any of the combined method of
prediction: on the EBI test dataset, linear discrimination and neural networks
significantly outperformed voting techniques. We conclude that it is better to
combine predictions.
PMID- 10679526
TI - Effect of the reaction field electrostatic term on the molecular dynamics
simulation of the activation domain of procarboxypeptidase B.
AB - Molecular dynamics simulations of the activation domain of porcine
procarboxypeptidase B (ADBp) were performed in order to examine the effects of
the inclusion of a reaction field (RF) term into the calculation of
electrostatics forces for highly charged proteins. Two simulations were performed
with the GROMOS96 package, studying the influence of counterions on the final
results. Comparison with previous results without the inclusion of the RF term
(Marti-Renom, M.A., Mas,J.M., Oliva,B., Querol,E. and Aviles,F.X., Protein Engng,
1998, 11, 101-110) shows that the structure is well maintained when the RF term
is included. Moreover, the analysis of the trajectories shows that simulations of
solvated highly-charged proteins are sensitive to the presence of counterions,
the secondary structures being more stable when their charges are neutralized.
PMID- 10679527
TI - Molecular modeling of the collagen-like tail of asymmetric acetylcholinesterase.
AB - The asymmetric form of acetylcholinesterase comprises three catalytic tetramers
attached to ColQ, a collagen-like tail responsible for the anchorage of the
enzyme to the synaptic basal lamina. ColQ is composed of an N-terminal domain
which interacts with the catalytic subunits of the enzyme, a central collagen
like domain and a C-terminal globular domain. In particular, the collagen-like
domain of ColQ contains two heparin-binding domains which interact with heparan
sulfate proteoglycans in the basal lamina. A three-dimensional model of the
collagen-like domain of the tail of asymmetric acetylcholinesterase was
constructed. The model presents an undulated shape that results from the presence
of a substitution and an insertion in the Gly-X-Y repeating pattern, as well as
from low imino-acid regions. Moreover, this model permits the analysis of
interactions between the heparin-binding domains of ColQ and heparin, and could
also prove useful in the prediction of interaction domains with other putative
basal lamina receptors.
PMID- 10679528
TI - An in vitro peptide folding model suggests the presence of the molten globule
state during nascent peptide folding.
AB - Although molten globules have been widely accepted as a general intermediate in
protein folding, there is no clear evidence to show their presence during nascent
peptide folding. This paper concentrates on whether the molten globule state
occurs, and if it does, when does it form during nascent peptide folding, by
comparing the changes in conformation during peptide chain extension of
staphylococcal nuclease R. The results show that a large N-terminal fragment of
staphylococcal nuclease, SNR121, which already contains more than 80% amino acid
sequence of the nuclease, is found to fulfill all the criteria for the molten
globule state, suggesting that the molten globule should occur at a later stage
of peptide elongation. At this stage the hydrophobic collapse of the polypeptide
chain occurs driven by the hydrophobic force, which leads to the formation of a
solvent-accessible non-polar core, characterized by the high ANS-binding
fluorescence. The nascent peptide folding of the nuclease is a hierarchical
process that at the very least includes the following steps: secondary structure
accumulation, pre-molten globule state, molten globule state, post-molten globule
state and finally the native state. Constant conformation adjustment is necessary
for correct folding and active expression of the protein.
PMID- 10679529
TI - Functional interdependence of DNA polymerizing and 3'-->5' exonucleolytic
activities in Pyrococcus furiosus DNA polymerase I.
AB - Pyrococcus furiosus DNA polymerase I (Pol BI) belongs to the family B (alpha
like) DNA polymerases and has a strong 3'-->5' exonucleolytic activity, in
addition to its DNA polymerizing activity. To understand the relationship between
the structure and function of this DNA polymerase, three deletion mutants, Delta1
(DeltaLeu746-Ser775), Delta2 (DeltaLeu717-Ser775) and Delta3 (DeltaHis672
Ser775), and two substituted mutants of Asp405, D405A and D405E, were
constructed. These substitutions affected both the DNA polymerizing and the 3'-
>5' exonucleolytic activities. The Delta1 mutant protein had DNA polymerizing
activity with higher specific activity than that of the wild-type Pol BI, but
retained only 10% of the exonucleolytic activity of the wild-type. The other two
deletion mutants lost most of both activities. These results suggest that the DNA
polymerizing and exonucleolytic activities are closely related to each other in
the folded structure of this DNA polymerase, as proposed in the family B DNA
polymerases.
PMID- 10679530
TI - From DNA sequence to improved functionality: using protein sequence comparisons
to rapidly design a thermostable consensus phytase.
AB - Naturally-occurring phytases having the required level of thermostability for
application in animal feeding have not been found in nature thus far. We decided
to de novo construct consensus phytases using primary protein sequence
comparisons. A consensus enzyme based on 13 fungal phytase sequences had normal
catalytic properties, but showed an unexpected 15-22 degrees C increase in
unfolding temperature compared with each of its parents. As a first step towards
understanding the molecular basis of increased heat resistance, the crystal
structure of consensus phytase was determined and compared with that of
Aspergillus niger phytase. Aspergillus niger phytase unfolds at much lower
temperatures. In most cases, consensus residues were indeed expected, based on
comparisons of both three-dimensional structures, to contribute more to phytase
stabilization than non-consensus amino acids. For some consensus amino acids,
predicted by structural comparisons to destabilize the protein, mutational
analysis was performed. Interestingly, these consensus residues in fact increased
the unfolding temperature of the consensus phytase. In summary, for fungal
phytases apparently an unexpected direct link between protein sequence
conservation and protein stability exists.
PMID- 10679531
TI - Tryptophan fluorescence of calmodulin binding domain peptides interacting with
calmodulin containing unnatural methionine analogues.
AB - The interactions between the abundant methionine residues of the calcium
regulatory protein calmodulin (CaM) and several of its binding targets were
probed using fluorescence spectroscopy. Tryptophan steady-state fluorescence from
peptides encompassing the CaM-binding domains of the target proteins myosin light
chain kinase (MLCK), cyclic nucleotide phosphodiesterase (PDE) and caldesmon site
A and B (CaD A, CaD B), and the model peptide melittin showed Ca(2+)-dependent
blue-shifts in their maximum emission wavelength when complexed with wild-type
CaM. Blue-shifts were also observed for complexes in which the CaM methionine
residues were replaced by selenomethionine, norleucine and ethionine, and when a
quadruple methionine to leucine C-terminal mutant of CaM was studied. Quenching
of the tryptophan fluorescence intensity was observed with selenomethionine, but
not with norleucine or ethionine substituted protein. Fluorescence quenching
studies with added potassium iodide (KI) demonstrate that the non-native proteins
limit the solvent accessibility of the Trp in the MLCK peptide to levels close to
that of the wild-type CaM-MLCK interaction. Our results show that the methionine
residues from CaM are highly sensitive to the target peptide in question,
confirming the importance of their role in binding interactions. In addition, we
provide evidence that the nature of binding in the CaM-CaD B complex is unique
compared with the other complexes studied, as the Trp residue of this peptide
remains partially solvent exposed upon binding to CaM.
PMID- 10679532
TI - A sparse matrix approach to the solubilization of overexpressed proteins.
AB - Many biophysical experiments depend on large amounts of pure, soluble protein.
Indeed, the revolution in structural biology has depended on molecular biology's
potential to make experiments possible by allowing the overexpression of normally
rare proteins in a heterologous host. All too often, however, overexpressed
proteins are poorly soluble in buffers that attempt to mimic physiological
conditions. Often in such cases the overexpressed protein is assumed to be
present in inclusion bodies and hopes of obtaining the desired sample from the
overexpression vector are abandoned. We have developed a sparse matrix approach
to the solubilization of such proteins that is often successful. This approach
relies on well accepted theories of protein solubility and folding to build a
sparse matrix that samples 'solubility space' effectively. The buffers of the
sparse matrix are used to make crude extracts that are rapidly assayed for
soluble protein using gel electrophoresis. We describe our approach and give
examples of its application.
PMID- 10679533
TI - In what way may race, ethnicity or culture influence asthma outcomes?
PMID- 10679534
TI - Asthma education and quality of life in the community: a randomised controlled
study to evaluate the impact on white European and Indian subcontinent ethnic
groups from socioeconomically deprived areas in Birmingham, UK.
AB - BACKGROUND: Whether asthma morbidity in minority groups can be reduced by
preventative health care measures delivered in the relevant ethnic dialects
requires further evaluation. This study reports clinical outcomes and quality of
life from a community based project investigating white European (W/E) and Indian
subcontinent (ISC) ethnic groups with asthma living in deprived inner city areas
of Birmingham, UK. METHODS: Six hundred and eighty nine asthmatic subjects (345
W/E, 344 ISC) of mean (SD) age 34.5 (15) years (range 11-59) and mean forced
expiratory volume in one second (FEV(1)) of 80% predicted were interviewed in
English, Punjabi, Hindi, or Urdu. Subjects randomised to the active limb of a
prospective, open, randomised, controlled, parallel group, 12 month follow up
study underwent individually based asthma education and optimisation of drug
therapy with four monthly follow up (active intervention). Control groups were
seen only at the beginning and end of the study. Urgent or emergency interactions
with primary and secondary health care (clinical outcomes) and both cross
sectional and longitudinal data from an Asthma Quality of Life Questionnaire
(AQLQ) were analysed. RESULTS: Clinical outcomes were available for 593 subjects.
Fewer of the active intervention group consulted their GP (41.8% versus 57.8%,
odds ratio (OR) 0.52 (95% CI 0.37 to 0.74)) or were prescribed antibiotics (34.9%
versus 51.2%, OR 0.51 (95% CI 0.36 to 0.72)), but by ethnicity statistically
significant changes occurred only in the W/E group with fewer also attending A&E
departments and requiring urgent home visits. Active intervention reduced the
number of hospital admissions (10 versus 30), GP consultations (341 versus 476),
prescriptions of rescue oral steroids (92 versus 177), and antibiotics (220
versus 340), but again significant improvements by ethnicity only occurred in the
active W/E group. AQLQ scores were negatively skewed to the higher values;
regression analysis showed that lower values were associated with ISC ethnicity.
Longitudinal changes (for 522 subjects) in the mean AQLQ scores were small but
statistically significant for both ethnic groups, with scores improving in the
active and worsening in the control groups. CONCLUSIONS: Active intervention only
improved clinical outcomes in the W/E group. AQLQ scores, although lower in the
ISC group, were improved by active intervention in both ethnic groups.
PMID- 10679535
TI - Relationship between exhaled nitric oxide and mucosal eosinophilic inflammation
in mild to moderately severe asthma.
AB - BACKGROUND: Exhaled levels of nitric oxide (NO) are raised in asthma but the
relationship between exhaled NO levels and a direct measure of airway
inflammation has not been investigated in asthmatic patients treated with inhaled
steroids. METHODS: The relationship between exhaled NO levels, clinical measures
of asthma control, and direct markers of airway inflammation were studied in
patients with asthma treated with and without inhaled corticosteroids. Thirty two
asthmatic patients (16 not using inhaled steroids and 16 using inhaled
beclomethasone dipropionate, 400-1000 microg/day) were monitored with respect to
measures of asthma control including lung function, symptom scores, medication
usage, and variability of peak expiratory flow (PEF) for one month. Measurements
of exhaled NO and fibreoptic bronchoscopy were performed at the end of the
monitoring period. Bronchial mucosal biopsy specimens were stained with an anti
MBP antibody for quantification of eosinophils. RESULTS: There was no significant
difference in lung function, symptom scores, or medication usage between the two
groups, but there was a significant difference in PEF variability (8.7 (1.2)% in
steroid naive patients versus 13.6 (1.9)% in steroid treated patients, p<0.05)
and exhaled NO levels (9.9 (3.5) ppb in steroid naive patients versus 13.6 (2.0)
ppb in steroid treated patients, p<0.05). There was no correlation between
exhaled NO and mucosal eosinophils, or between NO and conventional measures of
asthma control. There was a significant correlation between mucosal eosinophils
and lung function (r = -0.43, p<0.05). CONCLUSIONS: Exhaled NO levels do not
reflect airway mucosal eosinophilia and these markers reflect different aspects
of airway inflammation. The clinical usefulness of exhaled NO needs to be
determined in prospective longitudinal studies.
PMID- 10679536
TI - Is there any relationship between plasma antioxidant capacity and lung function
in smokers and in patients with chronic obstructive pulmonary disease?
AB - BACKGROUND: It has been suggested that oxidative stress is an important factor in
the pathogenesis of chronic obstructive pulmonary disease (COPD). We have shown
that an oxidant/antioxidant imbalance occurs in the distal air spaces of smokers
and in patients with COPD which is reflected systemically in the plasma. A study
was undertaken to determine whether plasma antioxidant status correlated with
lung function as assessed by forced expiratory volume in one second (FEV(1)) and
forced vital capacity (FVC) in smokers and patients with COPD. METHODS: Plasma
antioxidant capacity, assessed by the Trolox equivalent antioxidant capacity
(TEAC) as an index of overall systemic oxidative stress, and protein thiol levels
were measured in 95 patients with stable COPD, in 82 healthy smokers, and in 37
healthy non-smokers. RESULTS: Mean (SE) plasma TEAC levels were significantly
decreased in patients with COPD (0.81 (0.03) mmol/l, p<0.001) and in healthy
smokers (0.87 (0.04) mmol/l, p<0. 001) compared with healthy non-smokers (1.31
(0.11) mmol/l). The mean differences in plasma antioxidant capacity (mM) were
(0.81, 95% confidence interval (CI) 0.22 to 1.48), (0.87, 95% CI 0.2 to 1.46),
and (1.31, 95% CI 1.09 to 1.58) in patients with COPD, healthy smokers, and
healthy non-smokers, respectively. This reduction was associated with a 29% (95%
CI 18 to 38) and a 30% (95% CI 19 to 40) decrease in plasma protein thiol levels
in COPD patients and smokers, respectively. Current smoking was not the main
contributor to the reduction in antioxidant capacity in patients with COPD as
those patients who were still smokers had similar TEAC levels (mean (SE) 0. 78
(0.05); n = 25) to those who had stopped smoking (0.84 (0.02); n = 70). No
significant correlations were found between spirometric data measured as FEV(1) %
predicted or FEV(1)/FVC % predicted and the plasma levels of TEAC in patients
with COPD, healthy smokers, or healthy non-smokers. Similarly, there was no
significant correlation between FEV(1) % predicted or FEV(1)/FVC % predicted and
the levels of plasma protein thiols in the three groups. CONCLUSIONS: These data
confirm decreased antioxidant capacity in smokers and patients with COPD,
indicating the presence of systemic oxidative stress. However, no relationship
was found between protein thiols or TEAC levels and measurements of airflow
limitation in either smokers or in patients with COPD.
PMID- 10679537
TI - Lack of association between ipratropium bromide and mortality in elderly patients
with chronic obstructive airway disease.
AB - BACKGROUND: Ipratropium is commonly used for the management of elderly patients
with obstructive airway disease. However, a recent report suggested that its use
might be associated with a significant increase in mortality. A study was
therefore conducted to compare all-cause mortality rates between users and non
users of ipratropium in elderly patients with either asthma or chronic
obstructive pulmonary disease (COPD). METHODS: A retrospective cohort study was
performed using linked data from the Canadian Institute for Health Information,
the Ontario Drug Benefit Program, the Ontario Health Insurance Plan, and the
Ontario Registered Persons database. A total of 32 393 patients were identified
who were aged 65 years or older and who had been discharged from hospital with
asthma or COPD between 1 April 1992 and 31 March 1997. All-cause mortality rates
were compared between those treated and those not treated with ipratropium
following discharge from hospital. RESULTS: In total, 49% of patients received
ipratropium within 90 days of discharge. After adjusting for age, sex,
comorbidity, use of health services, and other airway medications there was no
significant association in patients with COPD between the use of ipratropium and
mortality (relative risk (RR) 1.03; 95% confidence interval (CI) 0.98 to 1.08).
In patients with asthma, however, there was a slight increase in the relative
risk of mortality associated with the use of ipratropium (RR 1.24; 95% CI 1.11 to
1.39). A dose-response increase in the mortality rate was not observed with
increasing use of ipratropium in either COPD or asthma. CONCLUSIONS: The use of
ipratropium in patients with COPD was not associated with an increase in
mortality. However, in asthma there was a small increase in the mortality rate.
Since asthmatic patients who received ipratropium had greater use of other airway
medications and health services, the difference in mortality rate between users
and non-users may be a reflection of unmeasured differences in asthma severity.
PMID- 10679538
TI - Airflow obstruction in bronchiectasis: correlation between computed tomography
features and pulmonary function tests.
AB - BACKGROUND: An obstructive defect is usual in bronchiectasis, but the
pathophysiological basis of airflow obstruction remains uncertain. High
resolution computed tomographic (CT) scanning now allows quantitation of static
morphological abnormalities, as well as dynamic changes shown on expiratory CT
scans. The aim of this study was to determine which static and dynamic structural
abnormalities on the CT scan are associated with airflow obstruction in
bronchiectasis. METHODS: The inspiratory and expiratory features on the CT scan
of 100 patients with bronchiectasis undergoing concurrent lung function tests
were scored semi-quantitatively by three observers. RESULTS: On univariate
analysis the extent and severity of bronchiectasis, the severity of bronchial
wall thickening, and the extent of decreased attenuation on the expiratory CT
scan correlated strongly with the severity of airflow obstruction; the closest
relationship was seen between decreased forced expiratory volume in one second
(FEV(1)) and the extent of decreased attenuation on the expiratory CT scan (R(s)
= -0.55, p<0. 00005). On multivariate analysis bronchial wall thickness and
decreased attenuation were consistently the strongest independent determinants of
airflow obstruction. The extent of decreased attenuation was positively
associated with the severity of bronchial wall thickness, but was not
independently linked to gas transfer levels. Endobronchial secretions seen on CT
scanning had no functional significance; the severity of bronchial dilatation was
negatively associated with airflow obstruction after adjustment for other
morphological features. CONCLUSIONS: These findings indicate that airflow
obstruction in bronchiectasis is primarily linked to evidence of intrinsic
disease of small and medium airways on CT scanning and not to bronchiectatic
abnormalities in large airways, emphysema, or retained endobronchial secretions.
PMID- 10679539
TI - Exhaled 8-isoprostane as a new non-invasive biomarker of oxidative stress in
cystic fibrosis.
AB - BACKGROUND: Cystic fibrosis is characterised by oxidative stress in the airways.
Isoprostanes are prostaglandin isomers formed by free radical catalysed
peroxidation of arachidonic acid. 8-Isoprostane is increased in interstitial lung
diseases, asthma, chronic obstructive pulmonary disease, and adult respiratory
distress syndrome. Exhaled nitric oxide (NO) and carbon monoxide (CO) are
biomarkers of inflammation and oxidative stress in the airways, respectively.
METHODS: Concentrations of 8-isoprostane in the breath condensate of 10 normal
subjects and 19 patients with stable cystic fibrosis were measured using an
enzyme immunoassay (EIA). Breath condensate is a non-invasive method of
collecting airway secretions. Exhaled nitric oxide (NO) and carbon monoxide (CO)
levels were measured by a chemiluminescence analyser. RESULTS: Concentrations of
8-isoprostane in the breath condensate of patients with stable cystic fibrosis
were increased about threefold compared with normal subjects (42.7 (4.5) pg/ml vs
15.2 (1.7) pg/ml; p<0.005, 95% CI 14.6 to 40.9). 8-Isoprostane concentrations
were negatively correlated with forced expiratory volume in one second in
patients with cystic fibrosis (r = -0.61; p<0.005). Exhaled CO was also increased
in patients with cystic fibrosis compared with normal subjects (6.7 (1.2) ppm vs
2.9 (0.3) ppm; p<0.05, 95% CI 0.2 to 7.4). 8-Isoprostane concentrations were
significantly correlated with CO levels (r = 0.66; p<0.002). CONCLUSIONS: The
results of this study show that oxidative stress is increased in cystic fibrosis
and may be quantified by measuring 8-isoprostane concentrations in breath
condensate.
PMID- 10679540
TI - Management of opportunist mycobacterial infections: Joint Tuberculosis Committee
Guidelines 1999. Subcommittee of the Joint Tuberculosis Committee of the British
Thoracic Society.
PMID- 10679541
TI - Severity prediction rules in community acquired pneumonia: a validation study.
AB - BACKGROUND: The British Thoracic Society (BTS) developed a rule (BTSr) based on
severity criteria to predict short term mortality in adults admitted to hospital
with community acquired pneumonia (CAP). However, neither the BTSr nor a recent
modification of it (mBTSr) have been validated in the UK. A case-control study
was conducted in a typical UK population to determine the clinical factors
predictive of mortality and to assess the performance of these rules. METHODS:
Cases were drawn from all patients with CAP who died in 1997 in five large
hospitals in the Mid Trent area. Controls were randomly selected from survivors.
Factors associated with mortality were identified following review of medical
case notes and performance of the severity prediction rules assessed. RESULTS:
Age >65 years, temperature <37 degrees C, respiratory rate >24 breaths/min,
mental confusion, urea concentration of >7 mmol/l, sodium concentration of <135
mmol/l, and the presence of a pleural effusion, all determined on admission, were
independently associated with in-hospital mortality on multivariate analysis. The
BTSr was 52% sensitive and 79% specific in predicting death while the mBTSr
displayed 66% sensitivity and 73% specificity. CONCLUSIONS: The value of three of
the four factors (presence of mental confusion, raised respiratory rate, raised
urea) used in the mBTSr as predictors of mortality is confirmed. However, the
BTSr and mBTSr did not perform as well in this validation study which included a
high proportion (48%) of elderly patients (> or =75 years) compared with the
derivation studies.
PMID- 10679542
TI - Randomised prospective parallel trial of therapeutic versus subtherapeutic nasal
continuous positive airway pressure on simulated steering performance in patients
with obstructive sleep apnoea.
AB - BACKGROUND: Obstructive sleep apnoea (OSA) impairs vigilance and may lead to an
increased rate of driving accidents. In uncontrolled studies accident rates and
simulated steering performance improve following treatment with nasal continuous
positive airway pressure (NCPAP). This study seeks to confirm the improvement in
steering performance in a randomised controlled trial using subtherapeutic NCPAP
as a control treatment. METHODS: Fifty nine men with OSA (Epworth Sleepiness
Score (ESS) of > or =10, and > or =10/h dips in SaO(2) of >4% due to OSA)
received therapeutic or subtherapeutic NCPAP ( approximately 1 cm H(2)O) for one
month. Simulated steering performance over three 30-minute "drives" was
quantified as: standard deviation (SD) of road position, deterioration in SD
across the drive, length of drive before "crashing", and number of off-road
events. The reaction times to peripheral target stimuli during the drive were
also measured. RESULTS: Subtherapeutic NCPAP did not improve overnight >4% SaO(2)
dips/h compared with baseline values, thus acting as a control. The SD of the
steering position improved from 0.36 to 0.21 on therapeutic NCPAP, and from 0.35
to 0.30 on subtherapeutic NCPAP (p = 0.03). Deterioration in SD of the steering
position improved from 0.18 to 0.06 SD/h with therapeutic NCPAP and worsened from
0.18 to 0.24 with subtherapeutic NCPAP (p = 0.04). The reaction time to target
stimuli was quicker after therapeutic than after subtherapeutic NCPAP (2.3 versus
2.7 seconds, p = 0.04). CONCLUSIONS: Therapeutic NCPAP improves steering
performance and reaction time to target stimuli in patients with OSA, lending
further support to the hypothesis that OSA impairs driving, increases driving
accident rates, and that these improve following treatment with NCPAP.
PMID- 10679543
TI - Non-invasive markers of airway inflammation as predictors of oral steroid
responsiveness in asthma.
AB - BACKGROUND: Sputum eosinophil counts and exhaled nitric oxide (NO) levels are
increased in asthma and both measurements fall in response to corticosteroids.
METHODS: Exhaled NO levels and sputum eosinophil counts were assessed as non
invasive markers of the response to an oral steroid in 37 patients (19 women)
with stable chronic asthma (mean (SD) age 48.6 (12.2) years, asthma duration 25.
9 (17.3) years, and baseline forced expiratory volume in one second (FEV(1)) 76.3
(21.9)% predicted). Spirometric tests, with reversibility to a beta agonist (2.5
mg nebulised salbutamol), and induced sputum (using nebulised 3% saline) were
performed at recruitment and following treatment with 30 mg prednisolone/day for
14 days. RESULTS: Baseline NO levels correlated with the percentage improvement
in FEV(1) from baseline to the post-steroid, post-bronchodilator value (r(s) =
0.47, p = 0.003), with an NO level of >10 ppb at baseline having a positive
predictive value of 83% for an improvement in FEV(1) of > or =15% (sensitivity
59%, specificity 90%). Sputum eosinophilia (> or =4%) had a positive predictive
value of 68% (sensitivity 54%, specificity 76%) for an increase in FEV(1) of > or
=15%. A combination of sputum eosinophilia and increased NO levels resulted in a
positive predictive value of 72% and a negative predictive value of 79%
(sensitivity 76%, specificity 75%). CONCLUSION: Exhaled NO levels and sputum
eosinophilia may be useful in predicting the response to a trial of oral steroid
in asthma.
PMID- 10679544
TI - Association of sputum parameters with clinical and functional measurements in
asthma.
PMID- 10679546
TI - Superior vena cava obstruction caused by radiation induced venous fibrosis.
AB - Superior vena cava syndrome is most often caused by lung carcinoma. Two cases are
described in whom venous obstruction in the superior mediastinum was caused by
local vascular fibrosis due to radiotherapy five and seven years earlier. The
development of radiation injury to greater vessels is discussed, together with
the possibilities for treatment of superior vena cava syndrome.
PMID- 10679545
TI - Asthma and poverty.
PMID- 10679547
TI - Mitral stenosis obscuring the diagnosis of plexogenic pulmonary arteriopathy and
familial pulmonary hypertension.
AB - A patient who died after surgery for critical mitral stenosis was found to have
underlying unrecognised plexogenic pulmonary arteriopathy and familial pulmonary
hypertension. The importance of recognising familial pulmonary hypertension is
discussed, together with the contribution of genetic and other risk factors to
plexogenic pulmonary arteriopathy.
PMID- 10679549
TI - Case Presentations in Clinical Tuberculosis.
PMID- 10679548
TI - Bronchiolitis obliterans organising pneumonia associated with the use of
nitrofurantoin.
AB - The spectrum of nitrofurantoin lung injury continues to widen. The case histories
are presented of two patients who developed lung disease associated with the use
of nitrofurantoin with histological features of bronchiolitis obliterans
organising pneumonia (BOOP), a rare but recognised form of drug induced injury.
The two middle aged women presented with respiratory symptoms after prolonged
treatment with nitrofurantoin. Both had impaired lung function and abnormal
computed tomographic scans, and their condition improved when nitrofurantoin was
withdrawn and corticosteroid treatment commenced. The favourable outcome in these
two patients contrasts with the fatal outcome of the two other reported cases of
nitrofurantoin induced BOOP. We suggest that the previous classification of
nitrofurantoin induced lung injury into "acute" and "chronic" injury is an
oversimplification in view of the wide variety of pathological entities that have
subsequently emerged.
PMID- 10679550
TI - Anti-Inflammatory Drugs in Asthma.
PMID- 10679575
TI - Thrombin-induced phosphorylation of MARCKS does not alter its interactions with
calmodulin or actin.
AB - Myristoylated alanine-rich C kinase substrate (MARCKS) is a calmodulin (CaM)- and
actin-binding protein and prominent protein kinase C (PKC) substrate. In vitro
phosphorylation of MARCKS by PKC has been shown to induce the release of both CaM
and actin, leading to the suggestion that MARCKS may regulate CaM availability
during agonist-induced signalling. In support of this hypothesis we previously
demonstrated that thrombin-induced MARCKS phosphorylation in endothelial cells
(EC) parallels activation of myosin light chain kinase, a CaM-dependent enzyme.
To test this theory further, we transfected CHO cells, which normally do not
express significant levels of MARCKS, with a MARCKS cDNA. The thrombin-stimulated
phosphorylation of myosin light chains and the sensitivity to CaM antagonists in
the MARCKS overexpressing cells was the same as that in control CHO cells. MARCKS
associated with the actin cytoskeleton in EC was markedly increased upon
treatment with the PKC activator, PMA, but only modestly enhanced by thrombin
treatment. Similarly, colocalisation of MARCKS with actin was enhanced when the
EC were challenged with PMA but not thrombin. These data may be partially
explained by PKC-independent phosphorylation of MARCKS in response to thrombin
stimulation.
PMID- 10679576
TI - Sphingolipid signalling domains floating on rafts or buried in caves?
AB - Ceramide is a novel lipid mediator involved in regulating cell growth, cell
differentiation and cell death. Many studies have focused on characterizing the
stimulus-induced production of ceramide and identifying putative downstream
molecular targets. However, little remains known about the localization of the
regulated production of ceramide through sphingomyelin metabolism in the plasma
membrane. Additionally, it is unclear whether a localized increase in ceramide
concentration is necessary to facilitate downstream signalling events initiated
by this lipid. Recent studies have suggested that detergent-insoluble plasma
membrane domains may be highly localized sites for initiating signal transduction
cascades by both tyrosine kinase and sphingolipid signalling pathways. These
domains are typically enriched in both sphingolipids and cholesterol and have
been proposed to form highly ordered lipid rafts floating in a sea of
glycerophospholipids. Alternatively, upon integration of the cholesterol binding
protein caveolin, these domains may also form small cave-like structures called
caveolae. Emerging evidence suggests that the enhanced sphingomyelin content of
these lipid domains make them potential substrate pools for sphingomyelinases to
produce a high local concentration of ceramide. The subsequent formation of
ceramide microdomains in the plasma membrane may be a critical factor in
regulating downstream signalling through this lipid messenger.
PMID- 10679577
TI - The essential role of H2O2 in the regulation of intracellular Ca2+ by epidermal
growth factor in rat-2 fibroblasts.
AB - We have investigated a new mechanism by which epidermal growth factor (EGF)
increases intracellular Ca(2+) ([Ca(2+)](i)) in Rat-2 fibroblasts. EGF induced a
transient increase of [Ca(2+)](i), and sustained Ca(2+) increase disappeared in
the absence of extracellular Ca(2+). However, EGF had no effect on the formation
of inositol phosphates. Expression of N17Rac or scrape-loading of C3 transferase
blocked the elevation of [Ca(2+)](i) by EGF, but not by lysophosphatidic acid
(LPA). EGF increased intracellular H(2)O(2), with a maximal increase at 5 min,
which was blocked by catalase, scrape-loading of C3 transferase, or expression of
N17Rac. H(2)O(2) scavengers, catalase and N-acetyl-L-cysteine, also blocked the
Ca(2+) response to EGF, but not to LPA. In the presence of EGTA, preincubation
with EGF completely inhibited subsequent Ca(2+) response to extracellular
H(2)O(2) and vice versa. Incubation with EGF or phosphatidic acid abolished
subsequent elevation of [Ca(2+)](i) by phosphatidic acid or EGF, respectively.
Furthermore, preincubation with LPA inhibited the subsequent Ca(2+) response to
EGF, but not vice versa. These results suggested that intracellular H(2)O(2)
regulated by Rac and RhoA, but not inositol phosphates, was responsible for the
EGF-stimulated elevation of [Ca(2+)](i). It was also suggested that EGF cross
talked with LPA in the regulation of [Ca(2+)](i) by producing intracellular
H(2)O(2).
PMID- 10679578
TI - Potentiation of calcium levels by extracellular arachidonic acid in nuclei
isolated from macrophages stimulated with receptor-recognized forms of alpha(2)
macroglobulin.
AB - Ligation of macrophage alpha(2)-macroglobulin signalling receptors (alpha(2)MSR)
with activated alpha(2)-macroglobulin (alpha(2)M*) increases intracellular
Ca(2+), and cytosolic phospholipase A(2) (cPLA(2)) and phospholipase D
activities. In view of the relationship between cellular Ca(2+) and mitogenesis,
we examined the effect of the product of cPLA(2) activity, arachidonic acid (AA),
on nuclear Ca(2+) levels in macrophages stimulated with alpha(2)M*, platelet
derived growth factor, and bradykinin. AA addition increased Ca(2+) levels in
Fura-2/AM loaded nuclei from both buffer-treated and agonist-stimulated cells,
but the increase in stimulated macrophages was 2-4-fold higher. Preincubation of
Fura-2/AM loaded nuclei with EGTA or BAPTA/AM abolished AA-induced increase in
nuclear Ca(2+) levels. Preincubation of nuclei with indomethacin did not affect
AA-induced increase in nuclear Ca(2+) in agonist-stimulated nuclei. It is
concluded that in macrophages stimulated with various agonists, AA, derived from
cPLA(2)-dependent hydrolysis of phospholipids, plays a significant role in
regulating nuclear Ca(2+) levels and thus nuclear functions.
PMID- 10679579
TI - Protein kinase and phosphatase modulation of quail brain GABA(A) and non-NMDA
receptors co-expressed in Xenopus oocytes.
AB - The GABA(A) receptor and the non-NMDA subtype of the ionotropic glutamate
receptor were co-expressed in Xenopus oocytes by injection of quail brain mRNA.
The oocytes were treated with various protein kinase (PK) and protein phosphatase
(PP) activators and inhibitors and the effects on receptor functioning were
monitored. Two phorbol esters, 4-beta-phorbol 12-myristate-13-acetate (PMA) and 4
beta-phorbol 12,13-dibutyrate (PDBu); the cGMP-dependent PK activators sodium
nitroprusside (SNP) and S-nitrosoglutathione (SNOG); and the PP inhibitor okadaic
acid (OA) reduced the amplitude of the GABA-induced currents, whilst the PK
inhibitor staurosporine potentiated it. In addition, PMA, PDBu, SNP, and OA
reduced the desensitization of the GABA-induced response. Identical treatments
generally had similar but less pronounced effects on responses generated by
kainate (KA) but the desensitization characteristic of the non-NMDA receptor was
not affected. None of the treatments had any effect on the reversal potentials of
the induced currents. Immunoblots revealed that the oocytes express endogenous
PKG and guanylate cyclase. The results are discussed in terms of the molecular
structures of GABA(A) and non-NMDA receptors and the potential functional
consequences of phosphorylation/dephosphorylation.
PMID- 10679580
TI - Evidence for stimulation of adenylyl cyclase by an activated G(s) heterotrimer in
cell membranes: an experimental method for controlling the G(s) subunit
composition of cell membranes.
AB - Heterotrimeric (alphabetagamma) G(s) mediates agonist-induced stimulation of
adenylyl cyclase (AC). Cholera toxin (CTx) will ADP-ribosylate the alpha-subunit
of G(s) (G(s)alpha). G(s)alpha-deficient cyc(-) membranes were "stripped" of
Gbeta. When the stripped cyc(-) were incubated with G(s)alpha and/or Gbetagamma,
each was incorporated into the membranes independently of the other. Both
G(s)alpha and Gbetagamma had to be present in the membranes, and they had to be
able to form a heterotrimer in order for CTx to ADP-ribosylate G(s)alpha,
indicating that the membrane bound G(s) heterotrimer is a substrate for CTx, but
the G(s)alpha subunit by itself is not. When G(s)alpha was completely and
irreversibly activated with GTPgammaS and incorporated into stripped cyc(-), it
was a poor substrate for CTx and a weak stimulator of AC unless Gbetagamma was
also incorporated. Furthermore, the level of AC stimulation corresponded to the
amount of G(s) heterotrimer that was formed in the membranes from GTPgammaS
activated G(s)alpha and Gbetagamma. These data suggest that AC is stimulated by
an activated G(s) heterotrimer in cell membranes.
PMID- 10679581
TI - [The journal enters the new millennium. A readership survey: why?].
PMID- 10679582
TI - [Intraductal mucinous papillary tumors of the pancreas: which procedure for which
tumor?].
PMID- 10679583
TI - [Megaduodenum in chronic intestinal pseudo-obstruction: management by
duodenectomy-duodenoplasty].
AB - BACKGROUND: Surgical management of primitive chronic intestinal pseudo
obstruction involving the duodenum (megaduodenum) is an uncommon but still
difficult problem. PATIENTS AND METHODS: Six patients who experienced severe
symptoms were managed by an original surgical procedure including partial
duodenal resection and reconstruction of a duodenal tract using a large duodenal
anastomosis (duodenectomy-duodenoplasty). RESULTS: There was no postoperative
complication. All preoperative symptoms completely regressed in all but one
patient who had previously undergone a vagotomy and experienced transient early
post-operative gastric stasis. With a median follow-up of 6 years (range 4-9),
all patients had good functional results without any evidence of other motility
disorders. The mean weight gain was 10 kg (range 7-15). CONCLUSIONS: Duodenectomy
duodenoplasty is a safe procedure resulting in efficient symptom relief in
patients suffering from megaduodenum.
PMID- 10679584
TI - [Intraperitoneal cisplatin plus epinephrine and surgical debulking for the
treatment of advanced peritoneal carcinomatosis in the rat].
AB - OBJECTIVE: To evaluate and compare the effects of cytoreductive surgery with
intraperitoneal cisplatin and epinephrine on peritoneal carcinomatosis in the
rat. MATERIAL AND METHODS: Twenty-day old peritoneal carcinomatosis was obtained
after intraperitoneal injection of 1 x 10(6) DHD/K12/PROb cells into BDIX rats.
The surgical treatment included electric fulguration of the peritoneal tumors
with spleen and omentum removal while intraperitoneal chemotherapy included
platinum (3 mg/kg) associated with epinephrine (2 mg/kg). RESULTS: Surgery did
not increase rat survival unlike cisplatin or cisplatin/epinephrine chemotherapy.
Intraperitoneal chemotherapy alone with cisplatin +/- epinephrine increased
survival but did not provide cure. Surgery followed by intraperitoneal cisplatin
and epinephrine cured four out of five twenty-day old peritoneal carcinomatosis.
CONCLUSION: Surgery combined with intraperitoneal cisplatin and epinephrine could
be an efficient treatment for peritoneal carcinomatosis in man.
PMID- 10679585
TI - Low sensitivity of invasive tests for the detection of Helicobacter pylori
infection in patients with bleeding ulcer.
AB - BACKGROUND: A high false negative rate for antral infection with Helicobacter
pylori when assessed by rapid urease test has recently been reported in patients
with bleeding ulcer. This result could partly explain the differing prevalence of
H. pylori infection in bleeding and non-bleeding ulcers. AIMS: To evaluate the
accuracy of a rapid urease test (UT), histology and culture for detection of H.
pylori in antral biopsies from acute bleeding peptic ulcer patients using a
serological test as reference. PATIENTS AND METHODS: All consecutive patients
with active bleeding gastric or duodenal ulcer at endoscopic examination admitted
in six university hospitals in France were considered for inclusion. Five antral
biopsies were taken during the diagnostic endoscopy for UT, culture and
histology. A blood sample was taken for H. pylori serology. RESULTS: One hundred
and eighty one patients were included and 129 (71%) had a positive serology. The
sensitivity of UT, histology and culture for detection of H. pylori infection
were 41%, 33% and 34%, respectively. The sensitivity and specificity of the
combination of the three invasive tests were 48.8% (95% CI: 40.2-57.4) and 90.6%
(95% CI: 82. 6-99) respectively. In the 52 serologically negative patients, only
5 had at least one invasive positive test. The sensitivity of the invasive tests
decreased significantly with age but was not influenced by NSAIDs intake. Of 80
patients with a positive serological test and negative histological evaluation
for H. pylori, chronic antral inflammation was found in 70 patients (87%). In 46
patients with both negative serological test and H. pylori negative test
according to histology, only 13 (28%) had chronic antral inflammation.
CONCLUSIONS: The sensitivity of invasive tests for detection of H. pylori is low
during acute ulcer bleeding, and they should be used with caution in this
condition. A serological test is recommended to identify patients with H. pylori
infection in spite of negative invasive tests.
PMID- 10679586
TI - [Anoperineal manifestations of Crohn's disease].
PMID- 10679587
TI - [Clinical hepatology at the dawn of the year 2000].
PMID- 10679588
TI - [Prevalence of hepatitis C in patients with chronic inflammatory bowel disease in
the region of Nice and evaluation of risk factors].
AB - OBJECTIVES: To estimate the prevalence of viral hepatitis C markers and to
determine independent risk factors in a population of patients with inflammatory
bowel disease. METHODS: We studied 117 consecutive out-patients (male/female,
53/64; mean age 41 +/- 16 yrs) with ulcerative colitis (43 patients) or Crohn's
disease (74 patients). Anti-hepatitis C virus antibodies were tested with a third
generation Elisa test. The following risk factors were tested for each patient:
duration of inflammatory bowel disease, number of colonoscopies, history of
surgical procedures, blood transfusions, intravenous drug abuse and
immunosuppressive treatments. RESULTS: The seroprevalence of hepatitis C virus
was 5.98% (7/117). The only risk factor independently associated with serological
markers for hepatitis C virus was blood transfusion (odds ratio: 7.77; confidence
interval: 95% (1.63-49.09); P=0.012). CONCLUSIONS: The prevalence of hepatitis C
virus infection was high in patients with inflammatory bowel disease, mainly due
to blood transfusions. Colonoscopies and surgical procedures were not found to be
additional risk factors for infection with hepatitis C virus.
PMID- 10679589
TI - [The Hepatitis Network in Maine-et-Loire city hospitals: six year follow-up of
patients and physicians. Hepatitis Network of Maine-et-Loire].
AB - OBJECTIVES: To evaluate 6 years of a city-hospital hepatitis network. The network
was set up in 3 steps: 1988: intrahospital network, 1991: city-hospital network,
1997: compliance with government regulations. METHODS: The whole activity from
1991 to 1997 was evaluated and special attention was paid to patient files and
participating physicians. RESULTS: From June 1991 to December 1997 (6.5 years),
759 patient files were registered which corresponds to 531 patients (male 57%)
with a mean age of 44 +/- 16 years (+/- standard deviation). Four hundred and
twenty one patients (79%) had hepatitis C, 95 (18%) hepatitis B and 15 (3%) co
infection; 83% of patients had had a liver biopsy confirming cirrhosis in 21.5%.
The annual number of files registered increased continuously. This was more a
result of recruiting known patients than new patients, after the network had been
in place for several years, mainly with hepatitis B virus (known patients in
1997: hepatitis B virus: 53% vs 33% for hepatitis C virus, P<0.05). Treatment
protocols (73%) were more frequent for hepatitis C virus patients than for
hepatitis B (73% vs 59%, P<0.01). Therapeutic trial proposals (37%) increased
from 21% in 1991 to 59% in 1997, P<0.01. Participation in monthly meetings by
academic hepato-gastroenterologists increased slightly while that of regional
hospital hepato-gastroenterologists increased markedly and that of private hepato
gastroenterologists remained stable. The annual proportion of files submitted by
academic hepato-gastroenterologists decreased in parallel to the increase in
submission of patient files by other hepato-gastroenterologists. CONCLUSIONS:
During 6 years of activity, the network grew with an increase in the annual
number of patient files, growing participation in therapeutic trials as well as
in monthly meetings by practitioners.
PMID- 10679590
TI - [Hepatic vascular malformations in Rendu-Osler disease].
PMID- 10679591
TI - [Pre-test].
PMID- 10679592
TI - [Treatment of gastrointestinal bleeding in patients with cirrhosis].
PMID- 10679593
TI - [Portal hypertension: primary prevention].
PMID- 10679594
TI - [Hemorrhage caused by ruptured esophageal varices in acute alcoholic hepatitis in
a patient with cirrhosis].
PMID- 10679595
TI - [Questions to Pr. P. Cales].
PMID- 10679596
TI - [Answers to the pre-test].
PMID- 10679597
TI - [Mesenteric localization of Castleman's disease].
AB - Castleman's disease (or angiofollicular lymph node hyperplasia) is a rare
pathologic process of unknown etiology. Commonly, it is an unique tumor localized
in the mediastinum (unicentric disease). Extrathoracic localizations are however
reported with an increasing frequency. We describe two cases of mesenteric
Castleman's disease. Diagnosis can be suggested by preoperative morphologic
explorations (ultrasonography with Doppler, computed tomography scan, magnetic
resonance imaging and angiography) and confrontation with clinical and biological
data (young age, biological signs of inflammation). In the classical unique tumor
of hyalin-vascular type, surgical removal allows definitive cure. Prognosis is
poor in the plasma cell type, mostly in multicentric disease due to a high
incidence of malignancy.
PMID- 10679598
TI - [Enucleation of intraductal papillary-mucinous tumor of the head of the pancreas.
Report of 2 cases].
AB - Intraductal papillary-mucinous tumors of the pancreas are characterized by
malignant transformation of unpredictable occurrence because of their unknown
natural history. Surgical treatment is duodenopancreatectomy or left
pancreatectomy even for benign tumors. We report 2 cases of benign intraductal
papillary-mucinous tumor confined to the head of the pancreas and treated by
enucleation.
PMID- 10679599
TI - [Emergence of resistant hepatitis B virus strains during long-term lamivudine
therapy in human immunodeficiency virus co-infected patients].
AB - Seven patients co-infected with hepatitis B virus (HBsAg and HBeAg carriers,
quantifiable HBV DNA with the bDNA technic) and human immunodeficiency virus
received a triple antiretroviral combination therapy, including lamivudine (150
mg twice a day). Hepatitis B viral load rapidly became undetectable in 6/7
patients. It remained below the level of detection in 2 subjects, after 20 and 22
months of treatment, with one of them achieving HBeAg/anti-HBe seroconversion.
However, in the other 4 individuals, hepatitis B viremia increased again after 8
to 16 months of lamivudine-containing regimen. The last patient was a non
responder. The 4 relapsers developed a double mutation Leu(528) for Met(528) and
Met(552) for Val(552), on hepatitis B virus polymerase, either concomitant (M8
and M16) with a hepatitis B virus DNA increase, or 2 months earlier (M10 and
M12). The high frequency of hepatitis B virus resistance to lamivudine emphasizes
the necessity of identifying more effective strategies, such as double
combination therapies.
PMID- 10679600
TI - [Hemorrhagic rectocolitis following liver transplantation for alcoholic
cirrhosis].
PMID- 10679601
TI - Geriatric nursing comes of age.
PMID- 10679602
TI - Research review committees in long-term care settings.
AB - As the number of elderly people grows, the interest in research for this
population increases. Federal funding is available for research regarding elders'
needs, and researchers are recognizing the problems this population incurs.
Residents and staff members in long-term care facilities are prime candidates for
study subjects, and institutional research review committees, supported by the
facilities' administration, are necessary to protect them. This article discusses
ways to establish a research review committee and its working processes.
PMID- 10679603
TI - A family perspective of family/staff interaction in long-term care facilities.
AB - This article explores the ways that families perceive their relationships with
the staff in long-term care facilities. Qualitative interviews were conducted
with 27 families who had elder members in two facilities in Ontario, Canada. The
families identified the staff characteristics that they valued and the ways they
developed relationships with staff members.
PMID- 10679604
TI - Comparison of pain assessment instruments in cognitively intact and cognitively
impaired nursing home residents.
AB - This study was conducted to determine which pain severity and location
instruments were most useful in the nursing home setting. Pain severity and
location were assessed monthly for 1 year in 37 participants enrolled in a
restorative rehabilitation program. Pain location was determined by the
residents' indications on a diagram, a doll, and their body. Pain severity was
determined by resident response to verbal, visual analog, faces, and word scales.
Cognitively impaired residents had greater difficulty using all instruments. The
McGill Word Scale was used most to determine pain severity. Pointing to
themselves most frequently determined pain location among residents. New
strategies are needed for pain assessment in the elderly, especially the
cognitively impaired elderly, and a combination of instruments to assess pain in
the latter group may be necessary.
PMID- 10679605
TI - Joyce Springate, EdD, RN,Contiguous Canadian Sister and Colleague.
PMID- 10679606
TI - Proudly professional: the Canadian Gerontological Nursing Association.
PMID- 10679607
TI - Aging and meaning in life: examining the concept.
AB - To make sense of their existence in the face of adversity and chaos or during
times of relative calm, human beings seek meaning. Meaning has been identified as
a significant factor in health and well-being in later years. Engaging in an
intensive literature search about meaning in later life constituted the beginning
step for a qualitative research study. By studying how older people experience
meaning in their lives, we may learn more about the human experiences of joy and
hope and their capacity to respond to opportunities and manage problems in their
lives.
PMID- 10679608
TI - Specialized care unit: family and staff perceptions of significant elements.
AB - Specialized care units (SCUs) for nursing home residents with dementia are
increasingly prevalent. Although reported to promote positive resident outcomes,
the specific characteristics of SCUs most likely to yield these outcomes have not
yet been identified. This article presents the findings of a qualitative study
that investigated the perceptions of family members and staff about SCU
characteristics that contribute to positive outcomes for residents with dementia.
All family and staff members interviewed agreed that the SCU fostered feelings of
personal space, personhood, and an unforced routine. These findings are discussed
and provide specific direction for care of nursing home residents with dementia.
PMID- 10679609
TI - Life albums in long-term care: resident, family, and staff perceptions.
AB - A life album is a collection of selected memorabilia, photographs, and archival
and other material that describes an individual's life in a photograph book
format. During a summer research program, 13 long-term care residents created
life albums that contained material from their past and current life. Some pages
were left unfilled to allow material to be added in the future. These albums
provided residents, families, and staff members with a means to recall life
events. This article reports their perceptions of creating such albums.
PMID- 10679610
TI - Resident abuse: an insider's perspective.
AB - The purpose of this study was to assess how resident abuse is perceived by
members of the long-term care institution. Groups of registered nurses,
nonprofessional staff, older residents, and significant others were interviewed
individually and participated in focus groups. Resident abuse is perceived by the
participants in this study as an experience that causes a perception of hurt in
older residents. This perception is voiced by either older residents themselves
or other members of the institution on their behalf. Participants' views about
resident abuse are always framed within the context of institutional life.
PMID- 10679611
TI - GN management leaders: Cheryl Ciechomski and Bernardine Gorek. Interview by
Priscilla Ebersole.
PMID- 10679612
TI - Jog your memory: a community screening model.
AB - This study's objectives were to establish an annual memory-screening week,
heighten public awareness of the issues surrounding cognitive impairments,
promote baseline cognitive screening as part of routine examinations in primary
care settings for the older adult, and detect early dementia and depression. The
264 participants completed demographic and anecdotal information and the
Geriatric Depression Scale (GDS). Nurses scored the GDS and administered the Mini
Mental State Examination (MMSE) and the Clock Drawing Test. Screening results and
educational information were given to the participants. Results revealed that 14%
of participants scored abnormally on the MMSE and approximately 14% had an
abnormal GDS score.
PMID- 10679613
TI - Advising older adults about pain remedies.
PMID- 10679614
TI - Telecaring in home care: making a telephone visit.
PMID- 10679616
TI - High-frequency dielectric study of side-chain dynamics in poly(lysine) aqueous
solutions.
AB - The high-frequency dielectric properties of poly(lysine) of different chirality
in aqueous solutions have been measured in the frequency range from 1 MHz to 1.8
GHz. The dielectric spectra show the existence of relatively small dielectric
dispersions at around 100 MHz that have been attributed to internal motion in the
polymer chain, due to side-chain polar groups. Our results indicate that the
local structure of the chain and its possibility to undergo a conformational
transition induced by pH does not modify the main feature of the side-chain
dynamics, the dielectric strength being largely proportional to the concentration
of charged groups. A similar behavior has been found in poly(alpha-glutamate) and
in poly(gamma-glutamate) aqueous solutions, where the dielectric parameters
appear to be related to the change in the charge density on the main chain,
rather than to the accompanying conformational helix-coil transition.
PMID- 10679615
TI - The third-dimensional structure of the complex between an Fv antibody fragment
and an analogue of the main immunogenic region of the acetylcholine receptor: a
combined two-dimensional NMR, homology, and molecular modeling approach.
AB - Binding of autoantibodies to the acetylcholine receptor (AChR) plays a major role
in the autoimmune disease Myasthenia gravis (MG). In this paper, we propose a
structure model of a putative immunocomplex that gives rise to the reduction of
functional AChR molecules during the course of MG. The model complex consists of
the [G(70), Nle(76)] decapeptide analogue of the main immunogenic region (MIR),
representing the major antigenic epitope of AChR, and the single chain Fv
fragment of monoclonal antibody 198, a potent MG autoantibody. The structure of
the complexed decapeptide antigen [G(70), Nle(76)]MIR was determined using two
dimensional nmr, whereas the antibody structure was derived by means of homology
modeling. The final complex was constructed using calculational docking and
molecular dynamics. We termed this approach "directed modeling," since the known
peptide structure directs the prestructured antibody binding site to its final
conformation. The independently derived structures of the peptide antigen and
antibody binding site already showed a high degree of surface complementarity
after the initial docking calculation, during which the peptide was
conformationally restrained. The docking routine was a soft algorithm, applying a
combination of Monte Carlo simulation and energy minimization. The observed shape
complementarity in the docking process suggested that the structure assessments
already led to anti-idiotypic conformations of peptide antigen and antibody
fragment. Refinement of the complex by dynamic simulation yielded improved
surface adaptation by small rearrangements within antibody and antigen. The
complex presented herein was analyzed in terms of antibody-antigen interactions,
properties of contacting surfaces, and segmental mobility. The structural
requirements for AChR complexation by autoantibodies were explored and compared
with experimental data from alanine scans of the MIR peptides. The analysis
revealed that the N-terminal loop of the peptide structure, which is
indispensable for antibody recognition, aligns three hydrophobic groups in a
favorable arrangement leading to the burial of 40% of the peptide surface in the
binding cleft upon complexation. These data should be valuable in the rational
design of an Fv mutant with much improved affinity for the MIR and AChR to be
used in therapeutic approaches in MG.
PMID- 10679617
TI - Arg side-chain-backbone interactions evidenced in model peptides by 17O-NMR
spectroscopy.
AB - The guanidinium group of arginine possesses a variety of biochemical functions,
either by participating in direct interactions in recognition processes, or by
stabilizing secondary structures. Three model compounds, selectively (17)O
enriched, Ac-Arg-Ala-[(17)O]Pro-NH(2) (1), Piv-Arg-Pro-[(17)O]Gly-NH(2) (2) (C
terminal segment of the luteinizing hormone releasing hormone), and Piv-Nle-Pro
[(17)O]Gly-NH(2) (3), were prepared and studied by (17)O-nmr spectroscopy. A
direct hydrogen-bonded interaction between the Arg side chain and the carbonyl
main chain carboxy-terminus was found, thus confirming the tendency of Arg to
participate in proton-acceptor functions.
PMID- 10679618
TI - Effect of lengthening of peptide backbone by insertion of chiral beta-homo amino
acid residues: conformational behavior of linear peptides containing alternating
L-leucine and beta-homo L-leucine residues.
AB - The synthesis and the solution behavior of the linear peptides containing a beta
homo (beta-H) leucine residue-Boc-Leu-beta-HLeu-Leu-OMe, Boc-beta-HLeu-Leu-beta
HLeu-Leu-OMe, and Boc-Leu-beta-HLeu-Leu-beta-HLeu-Leu-OMe-as well as the solid
structure of the tripeptide, are reported. The conformational behavior of the
peptides was investigated in solution by two-dimensional nmr. Our data support
the existence in solution with different families of conformers in rapid
interchange. The crystals of the tripeptide are orthorhombic, space group
P2(1)2(1)2, with a = 15.829(1) A, b = 29.659(1) A, c = 6.563(1) A, and Z = 4. The
structure has been solved by direct methods and refined to final R1 and wR2
indexes of 0.0530 and 0.1436 for 2420 reflections with I > 2sigma(I). In the
solid state, the tripeptide does not present intramolecular H bonds, and the
peptide backbone of the two leucine residues adopts a quasi-extended
conformation. For the beta-HLeu residue, the backbone conformation is specified
by the torsion angles straight phi(2) = -120.9(4) degrees, mu(2) = 56.7(4)
degrees, psi(3) = -133.2(4) degrees. The side chains of the three residues assume
the same conformation (g(-), g(-), trans), and all peptide bonds, except the
urethane group at the N-terminus, are in the trans conformation. Preliminary
conformational energy calculations carried out on the Ac-NH-beta-HAla-NHMe
underline that the conformations with mu angle equal to 180 degrees and 60
degrees assume lower energy with respect to the others. In addition, we found a
larger conformational freedom for the psi angle with respect to the straight phi
angle.
PMID- 10679619
TI - The crystal structure of Afc-containing peptides.
AB - A systematic structural analysis of Afc (9-amino-fluorene-9-carboxylic acid)
containing peptides is here reported. The crystal structures of four fully
protected tripeptides containing the Afc residue in position 2: Z-X(1)-Afc(2)
Y(3)-OMe (peptide a: X = Y = Gly; peptide b: X = Aib, C(alpha, alpha)
dimethylglycine, Y = Gly; peptide c: X = Gly, Y = Aib; peptide d: X = Y = Aib)
have been solved by x-ray crystallography. All the results suggest that the Afc
residue has a high propensity to assume an extended conformation. In fact, the
Afc residue adopts an extended conformation in three peptides examined in this
paper (peptides a-c). In contrast, Afc was found in a folded conformation, in the
3(10)-helical region, only in the peptide d, in which it is both preceded and
followed by the strong helix promoting Aib.
PMID- 10679620
TI - Conformational behavior of C alpha,alpha-diphenyl glycine: extended conformation
in tripeptides containing consecutive D phi G residues.
AB - Recent studies on the conformational preferences of the Dphig (C(alpha,alpha)
diphenylglycine) residue showed that this C(alpha,alpha)-disubstituted glycine
has a structural versatility. In fact, depending on the nature of the following
or preceding residue, Dphig can assume either folded or extended conformations.
We have carried out the analysis of the conformational preferences of the Dphig
residue in tripeptides containing consecutive Dphig residues. The crystal
structures of Z-Dphig-Dphig -Dphig-OMe (a; Z = benzyloxycarbonyl; OMe = methyl
ester), Z-Aib-Dphig-Dphig-OMe (b; Aib = alpha-aminoisobutyric acid), and Z-Ac(3)c
Dphig-Dphig-OMe (c; Ac(3)c = alpha-amino-cyclopropan carboxylic acid), are here
reported. The Dphig residues adopt the fully extended conformation in the three
tripeptides examined. Together with our previous findings on Dphig containing
peptides, the structures of the peptides here examined, indicate that the
presence of adjacent Dphig residue in the sequence further stabilizes the
extended conformation.
PMID- 10679621
TI - A spectroscopic and molecular mechanics investigation on a series of AIB-based
linear peptides and a peptide template, both containing tryptophan and a
nitroxide derivative as probes.
AB - Linear Aib-based hexapeptides, of the general formula Ac-Toac-(Aib)(n) -Trp
(Aib)(r) -OtBu [T(Aib)(n) Trp], where n + r = 4, and Toac is a nitroxide spin
labeled C(alpha,alpha)-disubstituted glycine, were investigated by steady-state
and time-resolved fluorescence measurements in different solvent media. A related
peptide, i.e., cyclo-?Orn-[(Aib)(2)-Trp-(Aib)(2)-Z]-Asp-[(Aib)(2)-Toac-(Aib)(2)-+
++OtBu ]? [T-cyclo-Trp], was also studied by the same techniques. It is a L-Orn,
L-Asp diketopiperazine template, to which two Aib-based chains are covalently
attached, each one containing one chromophore only, i.e., Trp or Toac. Whatever
the solvent, in the former series of peptides quenching of the excited Trp
exhibits three lifetime components and proceeds on a time scale from
subnanoseconds to a few nanoseconds, while in the case of the template the same
process occurs entirely on the nanoscale time scale, exhibiting two lifetimes
only. The ir absorption spectral patterns suggest that the backbone of the
peptides examined is in the 3(10)-helical conformation, as earlier determined by
x-ray diffraction for T(Aib)(3)Trp in the crystal state. In all cases, the
fluorescence results are satisfactorily described by a dipole-dipole interaction
mechanism, in which electronic energy transfer takes place from the excited Trp
to Toac, provided the mutual orientation between the fluorophore and Toac is
taken into account. This implies that interconversion among conformational
substates is slow on the time scale of the transfer process, allowing us to
estimate the dynamics of the process. Molecular mechanics calculations coupled
with time decay data made it possible to build up the most probable structures of
these peptides in solution.
PMID- 10679622
TI - The crystal structure of a Dcp-containing peptide.
AB - We have investigated the conformational preferences of a newly synthesized
C(alpha,alpha) symmetrically disubstituted glycine, namely alpha,alpha
dicyclopropylglycine (Dcp). We report here the crystal structure of a fully
protected dipeptide containing Dcp, namely Z-Dcp(1)-Dcp(2)-OCH(3). Both Dcp
residues are in a folded conformation. The overall peptide structural
organization corresponds to an alpha-pleated sheet conformation, similar to that
observed in linear peptides made up of alternating D- and L-residues and in Z-Aib
Aib-OCH(3) (Aib: alpha,alpha-dimethylglycine). These preliminary data suggest
that the Dcp could represent an alternative as molecular tool to stabilize folded
conformations.
PMID- 10679623
TI - Solid state structural analysis of the cyclooctapeptide cyclo- (Pro1-Pro-Phe-Phe
Ac6c-Ile-D-Ala-Val8).
AB - A solid state analysis of the cyclic octapeptide c(-Pro(1)-Pro-Phe-Phe-Ac(6)c-Ile
D-Ala-Val(8)-) (C8-CLA), containing the Pro-Pro-Phe-Phe sequence, followed by the
bulky helicogenic C(alpha,alpha)-dialkylated 1-aminocyclohexane-1-carboxylic acid
(Ac(6)c) residue and a D-Ala residue in position 7, has been carried out by x-ray
diffraction. The crystals, grown from a DMSO solution, are monoclinic, space
group P2(1) with a = 13.458(3) A, b = 19. 404(5) A, c = 21.508(4) A, and beta =
90.83(6) degrees, with two independent cyclic molecules in the asymmetric unit,
two DMSO molecules, and three water molecules. The structure has been solved
using the half and bake procedure by Sheldrick, and refined to final R1 and wR2
indices of 0.0613 and 0.1534 for 9867 reflections with I > 2sigma(I). This cyclic
peptide, a deletion analogue of the naturally occurring cyclic nonapeptide
cyclolinopeptide A [c(Pro-Pro-Phe-Phe-Leu-Ile-Ile-Leu-Val), CLA] has been
designed to study the influence of the ring size reduction on the conformational
behavior of CLA and more in general to obtain structural information on
asymmetric cyclic octapeptides. The compound exhibits, in the solid state, a
"banana-twisted" conformation with a cis peptide bond located between the two
proline residues. Five intramolecular H bonds stabilize the structure: one type
VIa beta-turn, two consecutive type III/I beta-turns, one gamma-turn, and one
C(16) bend. The structure has also been compared with either the solution
structure previously reported by us and obtained by nmr and computational
analysis, and with solid state structural data reported in the literature on
cyclic octapeptides.
PMID- 10679624
TI - Conformational restriction through C alpha i <--> C alpha i cyclization: Ac12c,
the largest cycloaliphatic C alpha,alpha- disubstituted glycine known.
AB - Two complete series of N-protected, monodispersed oligopeptide esters to the
pentamer level from 1-aminocyclododecane-1-carboxylic acid (Ac(12)c), an alpha
amino acid conformationally constrained through C(alpha)(i) <--> C(alpha)(i)
cyclization, and either L-Ala or Aib residues, along with the N-protected Ac(12)c
homopeptide alkylamide series from monomer to trimer, have been synthesized by
solution methods and fully characterized. The solution-preferred conformations of
these peptides have been assessed by Fourier transform ir absorption and (1)H-nmr
techniques. Moreover, the molecular structures of one derivative (Z-Ac(12)c-OH)
and three peptides [the tripeptide ester Z-L-Ala-Ac(12)c-L-Ala-OMe, the
tripeptide alkylamide Z-(Ac(12)c)(3)-NHiPr, and the tetrapeptide ester Z-(Aib)(2)
Ac(12)c-Aib-OtBu (Aib, alpha-aminoisobutyric acid)] have been determined in the
crystal state by x-ray diffraction. The results obtained point to the conclusion
that beta-bends and 3(10)-helices are preferentially adopted by peptides based on
Ac(12)c, the largest cycloaliphatic C-disubstituted glycine known. A comparison
with the structural tendencies extracted from published works on peptides from
Aib, the prototype of C-disubstituted glycines, and the other extensively studied
members of the class of 1-aminocycloalkane-1-carboxylic acids (Ac(n) c, with n =
3-9), is made and the implications for the use of the Ac(12)c residue in the
Ac(n) c scan approach of conformationally restricted analogues of bioactive
peptides are briefly discussed.
PMID- 10679625
TI - Effect of lysine residues on the deamidation reaction of asparagine side chains.
AB - The effect of lysine residues on the deamidation reaction of the asparagine side
chain has been studied on the peptide and on its lysine-acetylated derivative in
a wide range of pH values. The amino acid sequence of these peptides is similar
to the local sequence flanking the labile Asn-67 in RNAse A. The experimental
data show that Lys influences both the deamidation rate and the relative yield of
the two reaction products, i.e., the aspartic acid and beta-aspartic acid
containing peptide. These effects are pH dependent and can be rationalized based
on the mechanism previously proposed for the deamidation reaction via succinimide
derivative.
PMID- 10679626
TI - How the protein concentration affects unfolding curves of oligomers.
AB - The position of unfolding curves of oligomeric proteins depends on the protein
concentration. The extent of this dependence is analyzed here in terms of the
midpoint concentration, i.e., the denaturant concentration at which the fractions
of folded and unfolded protein are equal. Reexamination of published data
highlights that the midpoint concentration decreases as the protein concentration
becomes lower, as expected. Moreover, there are differences between urea and
guanidine hydrochloride, as well as discrepancies between the linear
extrapolation model and the denaturant binding model. These discrepancies could
be used to choose the denaturation model that best fits experimental data. The
equations used can be applied to any oligomeric system to check the validity of
the two-state assumption.
PMID- 10679627
TI - Amino acid preferences of small, naturally occurring polypeptides.
AB - An analysis of amino acid composition of small, naturally occurring peptides
ranging in size from 3 to 50 residues has been carried out. The purpose of the
study is to determine whether differential trends in amino acid usage exist for
small peptides compared to larger polypeptides and proteins. Results indicate
that Cys, Trp, and Phe are substantially more frequent in peptides compared to
their abundance in proteins at large. Aliphatic hydrophobic residues,
particularly Leu and Ile, are somewhat underrepresented, while the frequency of
Glu is significantly reduced. The shorter peptides are also more frequently
neutral and become increasingly charged as their size increases.
PMID- 10679628
TI - Evidence for a strong sulfur-aromatic interaction derived from crystallographic
data.
AB - We have uncovered new evidence for a significant interaction between divalent
sulfur atoms and aromatic rings. Our study involves a statistical analysis of
interatomic distances and other geometric descriptors derived from entries in the
Cambridge Crystallographic Database (F. H. Allen and O. Kennard, Chem. Design
Auto. News, 1993, Vol. 8, pp. 1 and 31-37). A set of descriptors was defined
sufficient in number and type so as to elucidate completely the preferred
geometry of interaction between six-membered aromatic carbon rings and divalent
sulfurs for all crystal structures of nonmetal-bearing organic compounds present
in the database. In order to test statistical significance, analogous probability
distributions for the interaction of the moiety X-CH(2)-X with aromatic rings
were computed, and taken a priori to correspond to the null hypothesis of no
significant interaction. Tests of significance were carried our pairwise between
probability distributions of sulfur-aromatic interaction descriptors and their
CH(2)-aromatic analogues using the Smirnov-Kolmogorov nonparametric test (W. W.
Daniel, Applied Nonparametric Statistics, Houghton-Mifflin: Boston, New York,
1978, pp. 276-286), and in all cases significance at the 99% confidence level or
better was observed. Local maxima of the probability distributions were used to
define a preferred geometry of interaction between the divalent sulfur moiety and
the aromatic ring. Molecular mechanics studies were performed in an effort to
better understand the physical basis of the interaction. This study confirms
observations based on statistics of interaction of amino acids in protein crystal
structures (R. S. Morgan, C. E. Tatsch, R. H. Gushard, J. M. McAdon, and P. K.
Warme, International Journal of Peptide Protein Research, 1978, Vol. 11, pp. 209
217; R. S. Morgan and J. M. McAdon, International Journal of Peptide Protein
Research, 1980, Vol. 15, pp. 177-180; K. S. C. Reid, P. F. Lindley, and J. M.
Thornton, FEBS Letters, 1985, Vol. 190, pp. 209-213), as well as studies
involving molecular mechanics (G. Nemethy and H. A. Scheraga, Biochemistry and
Biophysics Research Communications, 1981, Vol. 98, pp. 482-487) and quantum
chemical calculations (B. V. Cheney, M. W. Schulz, and J. Cheney, Biochimica
Biophysica Acta, 1989, Vol. 996, pp.116-124; J. Pranata, Bioorganic Chemistry,
1997, Vol. 25, pp. 213-219)-all of which point to the possible importance of the
sulfur-aromatic interaction. However, the preferred geometry of the interaction,
as determined from our analysis of the small-molecule crystal data, differs
significantly from that found by other approaches.
PMID- 10679629
TI - An examination of the steric effects of 5-tert-butylproline on the conformation
of polyproline and the cooperative nature of type II to type I helical
interconversion.
AB - The influence of steric effects on the helical geometry and the interconversion
of type II to type I polyproline in water was examined by the synthesis and
analysis of proline dimers and hexamers containing up to three (2S,5R)-5-tert
butylproline residues. In the dimers, the bulky 5-tert-butyl substituent was
found to exert a significant influence on the local prolyl amide geometry such
that the predominant trans-isomer in N-(acetyl)prolyl-prolinamide (1) was
converted to 63% cis isomer in N-(acetyl)prolyl-5-tert-butylprolinamide (2) as
measured by (1)H-nmr spectroscopy. Similarly, the presence of a 5-tert-butyl
group on the C-terminal residue in the polyproline hexamer Ac-Pro(5)-t-BuPro
NH(2) (4) produced a local 5-tert-butylprolyl amide population containing 61% cis
isomer in water. In spite of the presence of a local prolyl cis amide geometry,
the downstream prolyl amides in 4 remained in the trans isomer as determined by
NOESY spectroscopy. Conformational analysis by (13)C-nmr and CD spectroscopy
indicated that Ac-Pro(6)-NH(2) (3) adopted the all-trans amide polyproline type
II helix in water. As the amount of 5-tert-butylproline increased from one to
three residues in hexamers 4-6, a gradual destabilization of the polyproline type
II helical geometry was observed by CD spectroscopy in water; however, no
spectrum was obtained, indicative of a complete conversion to a polyproline type
I helix. The implications of these results are discussed with respect to the
previously proposed theoretical mechanisms for the helical interconversion of
polyproline, which has been suggested to occur by either a cooperative C- to N
terminal isomerization of the prolyl amide bonds or via a conformational
intermediate composed of dispersed sequences of prolyl amide cis and trans
isomers.
PMID- 10679630
TI - Solution structure of nocistatin, a new peptide analgesic.
AB - Nocistatin, a new heptadecapeptide encoded in the bPNP-3 gene, has a powerful
biological activity connected with the mechanisms of pain transmission. It does
not bind to the opioid receptors but to another brain receptor with high
affinity. In order to substantiate these novel biological data with a structural
basis, we have undertaken a conformational study in solution. Proton nmr data in
helicogenic solvents are consistent with a well-defined helical structure that is
consistent with the nmr parameters of the C-terminal octapeptide, a shorter
fragment that retains allodynia-blocking activity.
PMID- 10679631
TI - Electrostatic steering of substrate to acetylcholinesterase: analysis of field
fluctuations.
AB - Based on previous molecular dynamics simulation results for acetylcholinesterase
dimer, we calculate and analyse the electrostatic field fluctuations around the
enzyme. The results show that dynamic features of the electrostatic field favor
attraction of the positively-charged substrate. An Internet link to an animation
of the results is also provided.
PMID- 10679633
TI - Members of the biospectroscopy editorial advisory board, 1995-1999
PMID- 10679632
TI - Hydroxyl group interactions in polysaccharides: a deuterium-induced differential
isotope shift 13C-NMR investigation.
AB - The secondary isotope shift in (13)C-nmr spectra in water was used to obtain
information on the interactions of hydroxyl groups with their environment in
polysaccharides. Specifically, the possibility of detecting the preference of
intramolecular hydrogen bonding with respect to solvation was investigated.
Different aliphatic alcohols were studied in both protic and aprotic solvents in
order to obtain reference systems. The polysaccharides investigated were selected
so as to include both different types of glycosidic linkages and different
conformational properties of the polymeric chain. In addition to polysaccharides,
beta-cyclodextrin and inulin were also investigated. The experiments demonstrated
that isotope shift data can advantageously contribute to the understanding of the
conformational properties of polysaccharides and in particular, in setting up of
constraints in molecular modeling calculations.
PMID- 10679634
TI - Raman spectroscopic study of polycrystalline mono- and polyunsaturated 1
eicosanoyl-d(39)-2-eicosenoyl-sn-glycero-3-phosphocholines: bilayer lipid
clustering and acyl chain order and disorder characteristics.
AB - Polycrystalline lipid samples of a series of mono- and polyunsaturated, double
bond positional isomers of 1-eicosanoyl-d(39)-2-eicosenoyl-sn-glycero-3
phosphocholines [C(20-d(39)):C(20:1 Delta(j))PC, with j = 5, 8, 11, or 13; C(20
d(39)):C(20:2 Delta(11,14))PC; and C(20-d(39)):C(20:3 Delta(11, 14,17))PC] were
investigated using vibrational Raman spectroscopy to assess the acyl chain
packing order-disorder characteristics and putative bilayer cluster formation of
the isotopically differentiated acyl chains. Perdeuteration of specifically the
saturated sn-1 acyl chains for these bilayer systems enables each chain's intra-
and intermolecular conformational and organizational properties to be evaluated
separately. Various saturated chain methylene CD(2) and carbon-carbon (C&bond;C)
stretching mode peak height intensity ratios and line width parameters for the
polycrystalline samples demonstrate a high degree of sn-1 chain order that is
unaffected by either the double bond placement or number of unsaturated bonds
within the sn-2 chain. In contrast, the unsaturated sn-2 chain spectral
signatures reflect increasing acyl chain conformational disorder as either the
cis double bond is generally repositioned toward the chain terminus or the number
of double bonds increases from one to three. The lipid bilayer chain packing
differences observed between the sn-1 and sn-2 chains of this series of
monounsaturated and polyunsaturated 20 carbon chain lipids suggest the existence
of laterally distributed microdomains predicated on the formation of highly
ordered, saturated sn-1 chain clusters.
PMID- 10679635
TI - IR spectroscopic study of phospholipid emulsions containing cholesteryl oleate.
AB - As models for the lipid organization of low density lipoproteins (LDL), protein
free aqueous emulsions are prepared from dimyristoyl phosphatidyl choline (DMPC),
dipalmitoyl phosphatidyl choline (DPPC), and cholesteryl oleate (CO). Aqueous
dispersions containing these lipids are sonicated and yield stable particles with
diameters varying between 20 and 40 nm as measured through electron microscopy.
IR spectroscopy shows that emulsions consisting of DMPC, DPPC, and CO at 3/1/1
and 1/1/1 ratios undergo specific thermal transitions, depending on their
composition, that can be assigned to the phospholipids forming the surface layer
of the emulsion particles and to core-located CO. However, at the 1/3/1
DMPC/DPPC/CO ratio this lipid system exhibits an order-disorder transition of the
mixed phospholipids with no significant transition associated with core-located
CO. Observation of the methylene C&bond;H and C&bond;D stretching modes of
nondeuterated and deuterated lipids enables the packing characteristics and
conformational order of each lipid to be monitored separately. The transition
temperature changes compared to the temperatures for the analogous transitions in
neat CO and CO-free phospholipid vesicles suggest the existence of interactions
between CO and the above phospholipids in the ternary emulsion particles; these
interactions are stronger at the 1/3/1 DMPC/DPPC/CO ratio. The results show that
interactions between core and surface phases are dependent on the emulsion lipid
composition and that these findings may be extended to native lipoproteins.
PMID- 10679636
TI - Keratin orientation in wool and feathers by polarized raman spectroscopy.
AB - Good quality polarized Raman spectra of a single wool fiber and an intact feather
barbule are presented. The intensity ratio of the alpha-helix component of the
amide I band measured parallel and perpendicular to the wool fiber axis was 0.39
+/- 0.05. This is consistent with theoretical predictions based on orientational
calculations using the normal Raman polarizability tensor for an alpha-helical
amide I band where the protein strands are aligned roughly parallel with the
fiber axis. However, the depolarized spectral intensity of the alpha-helix mode
was greater than expected. For the feather barbule, despite high quality spectra,
a unique orientation of the beta-sheet structure could not be determined using
the Raman intensity ratios of the amide I band alone. Using previously developed
methods, the protein chains were found to be oriented between 60 and 90 degrees
from the long axis of the barbule compared to an angle of 51 degrees calculated
from polarized IR spectra of the same barbule. The Raman tensor methods for the
determination of protein orientation in these fibers was found to be constrained
by the complexity of the materials and the limitations of the band fitting
methods used to apportion the intensity among the various vibrational modes of
their spectra. Other advantages and limitations of polarized Raman microscopic
methods of structural determination are discussed.
PMID- 10679637
TI - Characterization of equilibrium intermediates in denaturant-induced unfolding of
ferrous and ferric cytochromes c using magnetic circular dichroism, circular
dichroism, and optical absorption spectroscopies.
AB - Protein unfolding during guanidine HCl denaturant titration of the reduced and
oxidized forms of cytochrome c is monitored with magnetic circular dichroism
(MCD), natural CD, and absorption of the heme bands and far-UV CD of the amide
bands. Direct MCD spectral evidence is presented for bis-histidinyl heme ligation
in the unfolded states of both the reduced and oxidized protein. For both redox
states, the unfolding midpoints measured with MCD, which is an indicator of
tertiary structure, are significantly lower than those measured with far-UV CD,
an indicator of secondary structure. The disparate titration curves are
interpreted in terms of a compound mechanism for denaturant-induced folding and
unfolding involving a molten globulelike intermediate state (MG) with near-native
secondary structure and nonnative tertiary structure and heme ligation. A
comparison of the dependence of the free energy of formation of the MG
intermediate on the redox state with the known contributions from heme ligation
and solvation suggests that the heme is significantly more accessible to solvent
in the MG intermediate than it is in the native state.
PMID- 10679638
TI - Flow analysis for determination of paraoxon with use of immobilized
acetylcholinesterase reactor and new type of chemiluminescent reaction.
AB - A highly sensitive flow analysis method for determination of acetylcholinesterase
(AChE) inhibitors like organophosphorous pesticides using a new chemiluminescent
reaction was developed and optimized. This method is fast, sensitive, and cheap,
because it requires only one enzyme and its substrate. The system incorporates a
reactor with immobilized AChE on controlled pore glass (CPG) and a
chemiluminometric detector. Variations in enzyme activity due to inhibition are
measured from the changes of concentrations of thiocholine produced when the
substrate (acetylthiocholine chloride) is pumped before and after the passage of
the solution containing the pesticide through the immobilized AChE reactor.
Thiocholine is determined by a new chemiluminescent reaction with luminol in the
presence of potassium ferricyanide. The percentage inhibition of enzyme activity
is correlated to the pesticide concentration. The inhibited enzyme is reactivated
by 10 mM pyridine-2-aldoxime methiodide (2-PAM). The experimental conditions were
first optimized for activity determination of the effect of pH, flow rates, and
Tris concentrations. For the measurement of AChE inhibition, the appropriate
concentration of the substrate is selected such that the rate of noninhibited
reaction can be considered unchanged and could be used as a reference. For
optimization of experimental conditions for inhibition, several parameters of the
system are studied and discussed: flow rate, enzyme-pesticide contact time,
luminol concentration, ferricyanide concentration, 2-PAM concentration, and
configuration of the FIA manifold. Paraoxon, an organophosphorous pesticide was
tested. For an inhibition time of 10 min the calibration graph is linear from 0.1
to 1 ppm paraoxon with a relative standard deviation (n = 5) of 4.6% at 0.5 ppm.
For an inhibition time of 30 min the calibration graph is linear from 25 to 250
ppb paraoxon.
PMID- 10679639
TI - IR study of self-assembly of capsular exopolymers from Pseudomonas sp. NCIMB 2021
on hydrophilic and hydrophobic surfaces.
AB - Capsular exopolymers (EPS) of the bacterium Pseudomonas sp. NCIMB 2021 are
allowed to self-assemble on hydrophilic and hydrophobic gold surfaces. Tapping
mode atomic force microscopy confirms the differences in the surface topography
between EPS adsorbed on both surfaces. Fourier-transform IR spectroscopy
indicates that the EPS surface coverage is much greater on the hydrophobic
surface. Furthermore, an increased contribution is observed from hydrophobic
(i.e., methyl and tyrosyl residues) and electrostatic (i.e., carboxylate
residues) groups at the hydrophobic surface, but there is relatively less neutral
polymer compared to the hydrophilic surface. The behavior of this EPS is in
agreement with the behavior of cells of Pseudomonas sp. NCIMB 2021 at hydrophilic
and hydrophobic surfaces.
PMID- 10679640
TI - Adrenocortical carcinoma: clinical and laboratory observations.
AB - BACKGROUND: The clinical features and natural history of adrenocortical carcinoma
are highly dependent on the type of center reporting their experience.
Observations from oncology services suggest a high incidence of nonfunctioning
tumors, whereas reports from endocrine clinics emphasize excessive corticoid and
androgen production in the majority of tumors. The incidence rate and natural
history of childhood adrenal carcinoma generally has been under emphasized.
METHODS: Over the past 17 years, the authors have evaluated and treated 47
patients with adrenocortical carcinoma referred to the University of Sao Paulo,
22 of whom were children. RESULTS: There is a bimodal age incidence of adrenal
carcinoma, with the disease peaking in the first and fourth decades of life.
Childhood adrenal carcinoma is characterized by a high rate of incidence of
virilization, marked overproduction of androgens, and a less aggressive clinical
course, and appears to be more amenable to surgical and other therapeutic
modalities. By contrast, adrenocortical carcinoma occurring in adults presents
more commonly as a mixed Cushing and virilizing syndrome, with overproduction of
corticoids and androgens and a far more aggressive clinical course, leading to
rapid death within months or years. Nonfunctioning adrenocortical carcinoma is
less common; it generally occurs in older adults and exhibits a rapid downhill
course. Modern day imaging methods have improved the diagnosis and staging of
adrenal carcinoma greatly. In the authors' experience, the histologic criteria of
Weiss appeared to predict tumor prognosis most accurately, whereas immunologic
markers, cytoskeletal markers, DNA ploidy, cell phase markers, and oncogenic
probes have yielded inconsistent results to date. Surgical removal of a localized
tumor remains the best hope for long term survival. Medical therapy with mitotane
and its successors in patients with Stage III or IV (MacFarlane system as
modified by Sullivan et al.) disease appear to have added little to longevity or
quality of life. CONCLUSIONS: When diagnosed in children, adrenal carcinoma is
associated with virilism and a less aggressive natural history; however, when it
occurs in adults, the disease presents more commonly as a mixed Cushing
virilizing syndrome and has a virulent course. The Weiss histologic criteria
appear to correlate best with disease prognosis, but other histochemical, cell
cycle, and genetic markers have not, to date, aided in disease management.
PMID- 10679641
TI - Vitamins, carotenoids, dietary fiber, and the risk of gastric carcinoma: results
from a prospective study after 6.3 years of follow-up.
AB - BACKGROUND: Numerous components of fruit and vegetables are considered to
decrease the risk of gastric carcinoma. In the current prospective study, the
authors examined the association between the intake of vitamins, carotenoids, and
dietary fiber and vitamin supplement use and the incidence rate of gastric
carcinoma. METHODS: The Netherlands Cohort Study began in 1986 with 120,852 men
and women ages 55-69 years. Data regarding diet and other covariates were
collected by means of a self-administered questionnaire. After 6.3 years of
follow-up, data regarding 282 incident cases of gastric carcinoma and 3123
subcohort members were available for case-cohort analyses. RESULTS: In analyses
adjusted for age, gender, smoking history, education, stomach disorders, and
family history of gastric carcinoma, an inverse association with vitamin C intake
(relative risk [RR] for highest vs. lowest intake category, 0.7; 95% confidence
interval [95% CI], 0.5-1.0) was observed, with a borderline significant trend
across three intake categories (P = 0. 06). After the exclusion of cases
diagnosed in the first and second follow-up years, the RR was 0.9 (95% CI, 0.6
1.2; P trend = 0.44). Intake of retinol and beta-carotene were associated
positively with gastric carcinoma risk with highest versus lowest quintile RRs of
1. 6 (95% CI, 1.0-2.5; P trend = 0.02) and 1.6 (95% CI, 1.0-2.6; P trend = 0.13),
respectively, after the exclusion of first-year and second-year cases. Intake of
folate, vitamin E, alpha-carotene, lutein plus zeaxanthin, beta-cryptoxanthin,
lycopene, and dietary fiber was not associated with gastric carcinoma. Patients
who used vitamin A-containing supplements had a lower risk of gastric carcinoma
than nonusers (RR = 0.4; 95% CI, 0.2-0.9). CONCLUSIONS: No clear inverse
associations were found between the intake of vitamins, carotenoids, and dietary
fiber and the risk of gastric carcinoma after adjustment for confounding
variables and the exclusion of first-year and second-year cases.
PMID- 10679642
TI - Molecular identification of metastatic cancer to the skin using laser capture
microdissection: a case report.
AB - BACKGROUND: In the current study the authors report a 57-year-old woman with a
scalp tumor and cervical lymphadenopathy who had a previously resected duodenal
carcinoid. Histologic and immunophenotypic characteristics of the duodenal
carcinoid differed from those of the scalp and cervical lymph node tumors,
prompting the use of molecular methodologies to make the diagnosis. METHODS:
Paraffin embedded tissues from the duodenal carcinoid, scalp, and lymph node
tumors were dissected using microscopic visualization and laser capture
microdissection. DNA was extracted and polymerase chain reaction (PCR) was
performed to evaluate loss of heterozygosity and microsatellite alterations using
primers flanking 22 polymorphic microsatellite markers from 9 chromosomal
regions, including genes associated with MEN-1 (11q), CDKN2 (9p), p53 (17p), and
bronchial carcinoid (3p). Microdissected lymphocytes from the three tissues were
used as source of constitutional DNA (controls). RESULTS: Fourteen of the 22
markers were informative (heterozygous in control lymphocytes). A marker on 3p12
showed loss of the same parental allele in the three tumors. A different marker
on 3p14.2 showed an identical shifted band in the three tumors indicative of a
common microsatellite alteration. CONCLUSIONS: The shared molecular abnormalities
among the three tumors indicated a common clonal origin, leading to a diagnosis
of primary duodenal carcinoid with clear cell metastases to the scalp and
cervical lymph nodes. These findings led to radiation therapy and immunotherapy
rather than chemotherapy. This case illustrates the novel application of laser
capture microdissection combined with PCR-based analyses of genomic markers for
the identification of the origin of metastatic disease.
PMID- 10679643
TI - Adenomatous polyposis coli I1307K mutation in Jewish patients with different
ethnicity: prevalence and phenotype.
AB - BACKGROUND: A new mutation, I1307K, recently was reported in the adenomatous
polyposis coli (APC) gene. This mutation was found to be predominant in Ashkenazi
Jews, creating a hypermutable area and predisposing the development of carcinoma.
The objective of the current study was to estimate the prevalence of this
mutation in several of the ethnic groups that comprise the Israeli population and
to elucidate the clinical features of the mutation carriers with colorectal
carcinoma (CRC). METHODS: A total of 111 consecutive CRC patients were evaluated
and their medical history and clinical data recorded. The general population (298
Ashkenazim and 189 Yemenites) also was tested for the presence of this mutation.
Mutation screening was performed using both the polymerase chain reaction-based
amplification refractory mutation system and a commercial APC kit. RESULTS: Of
the total of 111 CRC patients, 15 (13.5%) carried the I1307K mutation and 26 of
487 subjects from the general population (5.3%) carried the I1307K mutation (P =
0.004). Among the 71 Ashkenazi CRC patients there were 12 carriers (16.9%)
whereas 17 of the 298 Ashkenazi Jewish general population (5.7%) carried the
mutation (P = 0.004). Of the 4 CRC patients of Yemenite origin, 3 carried the
mutation and 9 carriers were found among 189 subjects in the general Yemenite
population (4.7%) (P = 0.0007). None of the 34 Sepharadic or 2 Arab CRC patients
carried the APC I1307K allele. Late age at diagnosis (64.6 years +/- 10.0, which
is similar to that of the noncarriers), mostly right-sided tumors, and moderate
to good differentiation constituted the phenotype of the mutation carriers.
CONCLUSIONS: The authors believe the findings of the current study broaden the
known spectrum of ethnic groups in which the APC I1307K mutation is prevalent.
The phenotype of the mutation carrier CRC patients does not conform to the
expected familial pattern of germline mutations. The phenotype and the
differential incidence rate of CRC among APC I1307K carriers of various ethnic
groups suggest low penetrance.
PMID- 10679644
TI - Abnormal expression of hepatoma specific gamma-glutamyl transferase and
alteration of gamma-glutamyl transferase gene methylation status in patients with
hepatocellular carcinoma.
AB - BACKGROUND: Hepatoma specific gamma-glutamyl transferase (HS-GGT) bands were
expressed in the development of hepatocellular carcinoma (HCC) and were
associated with a high incidence of HCC diagnosis. The objectives of this study
were to determine the levels of HS-GGT quantitatively in the sera of patients
with different liver diseases. The methylational status of GGT gene CCGG sites
was analyzed in hepatoma tissues. METHODS: The HS-GGT concentrations were
quantitatively analyzed in the sera of 156 HCC patients and others with liver
diseases or extrahepatic tumors. In 20 hepatoma tissues, the GGT enzyme proteins
were purified, the activities of GGTs of different molecular form were examined,
total RNAs were extracted and amplified by using a nested polymerase chain
reaction (PCR) assay, and the methylational status of CCGG site (M3) in the 5'
noncoding region of GGT genes was investigated with the restriction enzyme Hpa
II. RESULTS: Total GGT activities in patients with liver diseases and
extrahepatic tumors were abnormally increased. The levels of serum HS-GGT were
significantly elevated (P < 0.001) in the HCC group; the incidence of HS-GGT over
5.5 IU/L was 86% in HCC patients and less than 3% in patients with other
diseases. From liver cancer to distal noncancerous tissues, an increasing
tendency (P < 0.05) of total RNA concentrations was found; the frequencies of
amplified fragment and hypomethylated M3 site of GGT genes were 100% and 75% in
HCC, 85% and 55% in paracancerous tissues, and 75% and 50% in noncancerous
tissues, respectively. An inverse correlation was found between methylational
degrees of GGT genes and expression levels of GGT. CONCLUSIONS: The abnormal
alteration of serum HS-GGT level is a sensitive tumor marker for HCC diagnosis or
differentiation, and the overexpression of GGT in HCC may be related to the
hypomethylational status of CCGG sites of GGT genes.
PMID- 10679645
TI - Treatment of carcinoid syndrome: a prospective crossover evaluation of lanreotide
versus octreotide in terms of efficacy, patient acceptability, and tolerance.
AB - BACKGROUND: The somatostatin analogues lanreotide and octreotide have previously
been shown to be effective in controlling flushing and diarrhea in patients with
carcinoid syndrome. As lanreotide requires injection only every 10 days, compared
with twice-daily injections of octreotide, a direct comparison between these two
treatments in terms of patient acceptability, patient preference, and efficacy in
controlling symptoms was performed in patients with carcinoid syndrome. METHODS:
Thirty-three patients with carcinoid syndrome were included in an open,
multicenter, crossover study. Half of the patients received octreotide 200 microg
subcutaneously twice or thrice daily for 1 month followed by lanreotide 30 mg
intramuscularly every 10 days for 1 month, while the other half commenced with
lanreotide followed by octreotide in a similar fashion. Quality-of-life
assessments were performed at each visit and patient preference for one of the
two treatments evaluated. The number and intensity of flushing episodes and bowel
movements, urinary 5-hydroxyindoleacetic acid (5HIAA) levels, and plasma
serotonin levels were recorded. RESULTS: No significant differences were found
between lanreotide and octreotide in terms of quality of life. The majority of
patients (68%) preferred lanreotide (P = 0.03), largely due to its simplified
mode of administration. Disappearance or improvement in flushes occurred in 53.8%
of patients (14 of 26) while on lanreotide and in 68% (17 of 25) on octreotide. A
disappearance or improvement of diarrhea in 45.4% (10 of 22) on lanreotide,
compared with 50% (11 of 22) on octreotide, was also observed. Lanreotide and
octreotide were equally effective in reducing urinary 5HIAA levels and plasma
serotonin levels. Both treatments were well tolerated, with mild symptoms of
abdominal pain and nausea observed in 29% and 14% receiving octreotide and
lanreotide, respectively. CONCLUSIONS: Lanreotide and octreotide are equally
efficacious in terms of symptom control and reduction in tumor cell markers for
patients with carcinoid syndrome. Due to its simplified mode of administration,
most patients prefer treatment with lanreotide.
PMID- 10679646
TI - Current follow-up strategies after potentially curative resection of extremity
sarcomas: results of a survey of the members of the society of surgical oncology.
AB - BACKGROUND: The follow-up of patients after potentially curative resection of
extremity sarcomas has significant clinical and fiscal implications. However, the
ideal postoperative surveillance regimen for these uncommon neoplasms remains ill
defined. This study was designed to determine the current follow-up practices of
a large, diverse group of physicians who care for sarcoma patients. METHODS: The
1592 members of the Society of Surgical Oncology (SSO) were surveyed regarding
their follow-up practices with a detailed questionnaire mailed in 1997.
Information regarding frequency of follow-up testing was requested for extremity
sarcoma patients treated for cure based on 4 vignettes: low grade lesion = 5 cm
and > 5 cm and high grade lesion = 5 cm and > 5 cm. Respondents were asked to
indicate the number of office visits, laboratory tests and imaging studies
performed annually during the first 5 years and the 10th year after surgery.
RESULTS: Forty-five percent (716 of 1592) completed the survey. Of the 343
respondents who performed sarcoma surgery, 318 (93%) also provided long term
postoperative follow-up for their patients. Ninety-four percent of respondents
(295 of 318) were trained in general surgery and 5% (15 of 318) completed
orthopedic residencies. Ninety-one percent (291 of 318) were also fellowship
trained (80% in surgical oncology). Sixty-three percent (201 of 318) were in
academic practice. Routine office visits and chest X-ray (CXR) were the most
frequently performed items for each of the years. The frequency of office visits
and CXR increased with tumor size and grade and decreased with postoperative
year. Complete blood count and liver function tests were the most commonly
ordered blood tests, but many respondents did not order any blood tests
routinely. Imaging studies of the extremities were performed on the majority of
patients with large (> 5 cm) low grade lesions and on both large and small high
grade lesions during the first postoperative year. CONCLUSIONS: Postoperative
sarcoma surveillance strategies utilized by members of the SSO rely most heavily
on office visits and CXR. Tumor grade, tumor size, and postoperative year affect
surveillance intensity.
PMID- 10679647
TI - Menstrual and reproductive factors and risk of soft tissue sarcomas.
AB - BACKGROUND: Soft tissue sarcomas (STS) are a heterogeneous group of neoplasms
whose etiology remains largely undefined. A role for female hormones in the
development of STS has been suggested. To investigate this possibility, the
authors analyzed data from a hospital-based case-control study conducted in
Northern Italy between 1983 and 1998. METHODS: Cases were 104 women aged < 79
years with incident STS who were admitted to the cancer institutes and major
teaching and general hospitals. Controls were 505 women admitted to the same
network of hospitals for acute, nonneoplastic, nongynecologic, and nonimmune
related conditions. RESULTS: The multivariate odds ratio (OR) for women aged >/=
15 years compared with those aged < 12 years at menarche was 1.94 (95% confidence
intervals [95% CI], 0.80-4.74). No association with STS risk was observed for
menstrual cycle pattern, age at menopause, parity, and abortions. Late age at
first pregnancy and birth were found to be related to an increased risk of STS,
with an OR of 3.16 (95% CI, 0. 96-10.44) and 2.79 (95%% CI, 0.79-9.90) for women
aged >/= 30 years at first pregnancy and birth compared with those aged < 20
years. The trend in risk was significant for age at first pregnancy. No relation
with the risk of STS emerged for age at last birth and time since first or last
birth. CONCLUSIONS: The risk of STS was found to be weakly related to late age at
first pregnancy or birth, but not to other menstrual and reproductive factors.
PMID- 10679648
TI - High dose chemotherapy and autologous blood stem cell support in women with
breast carcinoma and isolated supraclavicular lymph node metastases.
AB - BACKGROUND: The prognosis of patients with isolated supraclavicular lymph node
(SCN) metastases is similar to patients with metastatic breast carcinoma
involving other sites. Because these patients have a lower disease burden
compared with women with distant metastases, their outcome after high dose
chemotherapy (HDCT) may be superior. METHODS: The authors evaluated event free
survival (EFS) and overall survival in a series of 20 consecutive women with SCN
metastases as the only site of metastatic disease who were treated with HDCT and
peripheral blood stem cell transplantation at The Toronto Hospital. All patients
had responded to 4-6 cycles of induction CT using either an anthracycline
containing regimen or a single agent taxane, and received intensive therapy
comprised of mitoxantrone, 64 mg/m(2); cyclophosphamide, 6000 mg/m(2); and
carboplatin, 800-2000 mg/m(2), each divided over 4 days followed by the infusion
of autologous peripheral blood stem cells. Involved field radiation therapy (RT)
was administered when possible after transplantation to the supraclavicular fossa
and tamoxifen was given to previously untreated patients if they were hormone
receptor positive or if their hormone receptor status was unknown. RESULTS: At a
median follow-up of 28 months, 13 of the 20 women were alive, 11 of whom (55%)
remained in continuous complete remission. There were no treatment-related
deaths. The median overall survival was 37 months and the median progression free
survival was 32 months from the date of transplantation. Consolidative RT was
delivered to 11 women and on univariate analysis was found to be significantly
associated with better EFS (P = 0.02). CONCLUSIONS: The long term outcome of
women with breast carcinoma and isolated SCN metastases whose disease is
sensitive to CT appears to be favorable; whether this result is superior to that
achieved with standard therapy alone remains to be confirmed in prospective,
randomized trials.
PMID- 10679649
TI - The predictive value of body protein for chemotherapy-induced toxicity.
AB - BACKGROUND: The use of body surface area in determining chemotherapy dosing,
particularly in the obese, remains controversial. Total body nitrogen (TBN)
measurement in patients with serious illness has been suggested to be an accurate
predictor of clinical course. The ability of TBN to predict chemotherapy-induced
neutropenia was examined in the current study. METHODS: TBN measurements were
performed in 31 female outpatients with breast carcinoma who were undergoing
standard cyclophosphamide, methotrexate, and 5-fluorouracil (CMF)-based
chemotherapy (median age, 48 years; range, 26- 77 years). TBN was measured using
the in vivo neutron capture analysis technique on Day 1 of Cycles 2-6. The
chemotherapy toxicity index used was the absolute neutrophil count nadir (ANCN).
Neutropenia was defined as an ANCN < 1.0 x 10(9)/L. The nitrogen index (NI) (TBN
expressed as a percentage of age-, gender-. and height-matched healthy patients)
then was compared with the corresponding ANCN values. RESULTS: Using receiver
operating characteristics analysis, a "cut-off" value of NI = 0.89 was found. In
this group of patients, when the NI was < 0.89, 11 of 13 courses in 7 patients
(85%) led to an ANCN of < 1.0 x 10(9)/L, and when the NI was > 0.89, 29 of 109
courses (27%) led to an ANCN of < 1.0 x 10(9)/L (P < 0.0001). CONCLUSIONS: In
this small group of breast carcinoma patients, the NI was found to be the most
powerful predictor of neutropenia after CMF-based chemotherapy. The authors
conclude that NI may be a useful clinical tool in identifying patients at a
higher risk of chemotherapy-induced toxicity when widely distributed drug
combinations such as CMF are used, and warrants further study with other commonly
used drugs or drug regimens.
PMID- 10679650
TI - The prognostic value of p53 and c-erb B-2 immunostaining is overrated for
patients with lymph node negative breast carcinoma: a multivariate analysis of
prognostic factors in 613 patients with a follow-up of 14-30 years.
AB - BACKGROUND: Approximately 30% of breast carcinoma patients with negative lymph
nodes die of their disease. Biologic markers such p53 protein and c-erb B-2 have
been related to tumor progression, but their prognostic value remains
controversial. METHODS: Two large series of a total of 613 lymph node negative
breast carcinoma patients from a single institution were analyzed with respect to
tumor size, histologic grade, and immunohistochemical staining for p53, c-erb B
2, estrogen receptor (ER), and progesterone receptor (PgR). Interobserver
variation in histologic grading was evaluated by Kappa statistics. The two series
had different treatment modalities: 228 patients (SACGS group) were treated
surgically with mastectomy and given 1 perioperative chemotherapy course, and 385
patients (HOST group) were treated with mastectomy and ovarian radiation and
further randomized to receive postoperative treatment with radiotherapy or no
adjuvant treatment. The follow-up ranged from 14-30 years. RESULTS:
Immunoreactivities for p53, c-erb B-2, ER, and PgR did not differ significantly
in the two series. p53 immunostaining was present in 187 of 613 tumors (29%), and
c-erb B-2 immunoreactivity was present in 58 of the tumors (10%). Three hundred
forty-eight tumors (57%) were positive for ER. Kappa statistics value of
interobserver variation in the histologic grading of ductal carcinomas was 0.69,
which is considered to be a substantial degree of agreement. No significant
differences in survival were found when comparing p53, c-erb B-2, ER, and PgR
positive and negative cases. However, both recurrence free survival rates and
overall survival rates after 10 years were significantly better in the T1N0M0
group compared with the T2N0M0 group (81% vs. 67% [P < 0.0001] and 85% vs. 70% [P
< 0.0001]). Ten-year recurrence free survival rates for patients with histologic
Grade 1 versus Grades 2-3 (according to Elston and Ellis' modification of the
Bloom and Richardson method) tumors were 90% and 70%, respectively (P < 0. 0001),
and overall survival rates for the same groups were 94% and 81%, respectively
(P=0.0002). After 30 years of follow-up, the overall survival rate for patients
with tumors of histologic Grade 1 versus Grades 2-3 were 87% and 68%,
respectively, and were 78% and 66%, respectively, for patients with tumors = 2
mm versus those with tumors > 20-50 mm. Approximately 35% of the patients with
tumors of histologic Grades 2-3 and measuring > 20 mm were dead after 10 years of
follow-up, contrary to 6% of the patients with tumors of histologic Grade 1
measuring = 20 mm. A significantly more favorable prognosis also was observed
in patients in the HOST group treated with adjuvant radiotherapy. CONCLUSIONS:
Histologic grade and tumor size were found to be major prognostic factors for
patients after 30 years of follow-up. c-erb B-2 and p53 immunostaining does not
appear have any independent prognostic value. Adjuvant radiotherapy may be of
value in the treatment of patients with localized tumors.
PMID- 10679651
TI - The frequency of p53, K-ras mutations, and microsatellite instability differs in
uterine endometrioid and serous carcinoma: evidence of distinct molecular genetic
pathways.
AB - BACKGROUND: The two most common types of uterine endometrial carcinoma,
endometrioid (UEC) and serous (USC), differ in their histopathologic appearance
and biologic behavior. Recent studies suggest that these differences may be
associated with distinct molecular genetic alterations. METHODS: In the current
study, the authors compared the frequencies of K-ras and p53 mutations and
microsatellite instability (MI) between UEC and USC by analyzing all 3 molecular
genetic changes in one set of tumors. Furthermore, the distribution of these
molecular genetic alterations was determined among UECs of different
histopathologic grade. The authors analyzed 58 UECs with known MI status for K
ras and p53 mutations. The K-ras and p53 genes were analyzed in 45 and 6 cases of
USC, respectively. These results were combined with previous data on p53
mutations (21 cases) and MI (34 cases) in USC. RESULTS: MI was present in 16 of
57 UECs (28%) but in none of 34 USCs. p53 mutations were found in 7 of 42 UECs
(17%) and 25 of 27 USCs (93%) by direct sequencing of exons 5-8. UECs and USCs
with p53 mutations showed strong immunoreactivity for p53 in about 85% of the
cases, whereas about 15% of the cases were immunonegative. K-ras mutations at
codon 12 were found in 15 of 58 UECs (26%) and in only 1 of 45 USC (2%) by dot
blot oligohybridization after polymerase chain reaction amplification of exon 1.
Notably, the frequency of both K-ras and p53 mutations and MI was significantly
different between UEC and USC (P < 0.001). In UECs, MI and K-ras mutations
occurred in low grade as well as in high grade tumors, whereas p53 mutations were
present almost exclusively in high grade tumors. CONCLUSIONS: The results of this
study suggest that different molecular genetic pathways are involved in the
pathogenesis of UEC and USC and that low grade UEC may progress to high grade
UEC. These findings support the hypothesis that UEC and USC are separate entities
and suggest that different molecular genetic alterations may be responsible for
their distinct morphology and biologic behavior.
PMID- 10679652
TI - A randomized study comparing standard versus moderately high dose megestrol
acetate for patients with advanced prostate carcinoma: cancer and leukemia group
B study 9181.
AB - BACKGROUND: Megestrol acetate (MA) is a synthetic progestin with reported
activity in both hormone-sensitive and hormone-refractory prostate carcinoma
(HRPC). Based on limited data suggesting a possible dose-response effect, a trial
was initiated to compare standard versus moderately high dose MA in HRPC.
METHODS: One hundred forty-nine men with hormone-refractory prostate carcinoma
were randomized to receive oral MA either at 160 mg/day (low dose) or 640 mg/day
(high dose). Patients were stratified by performance status and measurable versus
evaluable disease. The primary end point was tumor response. Secondary end points
were survival, quality-of-life measures, and prostate specific antigen (PSA)
decline. RESULTS: The median survival times of 11.2 months for patients who
received the low dose and 12.1 months for patients who received the high dose
therapy were not significantly different. Best response was equivalent in the 2
arms: 2 partial responses and 22 patients with stable disease for the 160 mg/day
dose, and 1 partial response and 28 patients with stable disease for the 640
mg/day dose. A greater than 50% decline in PSA occurred in 13.8% and 8.8% of
patients in the low and high dose treatment arms, respectively. There were no
differences in the toxicity or quality-of-life outcomes between the two arms.
Poorer performance status (2 vs. 0-1), greater than 5% weight loss, higher
baseline PSA, and measurable disease all predicted shorter survival. CONCLUSIONS:
MA has limited activity in hormone-refractory prostate carcinoma, and there is no
apparent dose-response correlation.
PMID- 10679653
TI - Independent value of tumor size and DNA ploidy for the prediction of disease
progression in patients with organ-confined renal cell carcinoma.
AB - BACKGROUND: Greater than 20% of patients with apparently localized renal cell
carcinoma (RCC) present with disease progression after surgery. The objective of
the current study was to improve the ability of clinicians to predict prognosis
in patients with localized RCC. METHODS: The authors studied 154 patients with
organ-confined RCC classified as pT1 to pT2-pN0-M0 who underwent radical
nephrectomy. Follow-up ranged from 24-128 months (median, 72 months). Several
morphologic parameters of the tumor were considered. DNA content was analyzed by
flow cytometry and tumor size was determined from the surgical specimen. A Cox
proportional hazards regression model was used to identify significant
independent prognostic factors for disease progression. RESULTS: At 5 and 10
years of follow-up, disease free survival was found to be 87% and 86%,
respectively. Univariate analysis revealed that DNA content, Furhman grade, and
tumor size had a statistically significant predictive value for disease
progression, whereas, with regard to grade, the difference was significant only
between patients with Grade 3 tumors and all other patients with Grade 1-2 tumors
(P < 0. 0001). Although DNA content was found to correlate with tumor size (P <
0.0001), multivariate analysis showed that these were the only significant
independent predictors of disease progression. The sum of DNA content and tumor
size therefore was considered to distinguish separate risk groups. For a patient
with diploid RCC, the risk of progression increased from 4% if the tumor size was
3 cm to 43% if the tumor size was 10 cm. For a patient with nondiploid RCC, this
risk was 32% if the tumor size was 3 cm, increasing to 99% for tumors measuring
10 cm. CONCLUSIONS: Stratification of organ-confined RCC according to tumor size
and DNA content could possibly provide more information that could be useful in
the selection of individuals with significantly different risks of disease
progression.
PMID- 10679654
TI - Paraganglioma of the urinary bladder: can biologic potential be predicted?
AB - BACKGROUND: Paraganglioma of the urinary bladder is rarely encountered and its
biologic behavior is uncertain. The authors sought to determine the prognostic
factors that would predict patient outcome. METHODS: The Mayo Clinic experience
over 53 years with paraganglioma of the bladder was reviewed. All histologic
slides from 16 patients were reviewed by the authors. Eight cases were examined
immunohistochemically with cytokeratin (AE1/3, cytokeratin 7, and cytokeratin
20), vimentin, S-100 protein, neuroendocrine markers (chromogranin,
synaptophysin, and neuron specific enolase), p53 protein, and MIB-1. DNA ploidy
was determined by digital image analysis in formalin fixed, paraffin embedded
tissue. The mean follow-up was 6.3 years (range, 0.4-16.4 years). RESULTS:
Paraganglioma usually occurred in young adult women (mean age, 45 years; range,
16-74 years). The male-to-female ratio was 1 to 3. The common symptoms and signs
were hypertension and hematuria. The tumors were usually located intramurally in
the lateral and posterior wall of the bladder and were multifocal in 3 cases
(18%). Seven patients were treated by transurethral resection, eight by partial
cystectomy, and one by radical cystectomy. T classification was T1 (1 patient),
T2 (9 patients), T3 (2 patients), and T4b (4 patients). At the time of diagnosis,
one patient had distant metastasis and one had regional lymph node metastasis.
One patient developed metastasis 1 year after diagnosis and died of the disease
1.5 years later. None of the patients with T1 or T2 tumors had recurrence or
tumor progression. All tumors were aneuploid. The mean MIB-1 labeling index was
1.5% (range, 0.03-7.0%). The tumor cells displayed immunoreactivity for S-100
protein and neuroendocrine markers and were negative for p53 (except 1 case) and
cytokeratin. CONCLUSIONS: Paraganglioma of the urinary bladder occurs mostly in
young adult women. Patients with tumor of advanced classification (>/=T3) are at
risk of recurrence, metastasis, and dying of the disease, whereas patients in
this study with T1 or T2 disease had favorable outcomes after complete tumor
resection.
PMID- 10679655
TI - Atypical nephrogenic metaplasia of the urinary tract: a precursor lesion?
AB - BACKGROUND: Nephrogenic metaplasia with cytologic atypia (atypical nephrogenic
metaplasia) is occasionally encountered and its biologic potential is uncertain.
METHODS: The authors describe 18 cases of atypical nephrogenic metaplasia
characterized by the presence of prominent cytologic atypia, including nuclear
enlargement, nuclear hyperchromasia, and enlarged nucleoli. DNA ploidy analysis
by digital image analysis and immunostaining for high-molecular-weight
cytokeratin (34betaE12), cytokeratin 7, cytokeratin 20, carcinoembryonic antigen
(CEA), epithelial membrane antigen (EMA), p53, and MIB-1 were performed in 9
cases. RESULTS: The mean patient age was 62 years (median, 65 years; range, 39-84
years). The male-to-female ratio was 2.6:1. Two patients had a history of
noninvasive papillary urothelial carcinoma. The typical clinical presentation was
hematuria (8 patients) and voiding symptoms (5 patients). Cystoscopic findings
were suspicious for neoplasm in 7 of 13 cases. The neoplastic cells were positive
for high-molecular-weight cytokeratin, cytokeratin 7, and EMA, and were usually
negative for cytokeratin 20 and CEA. p53 nuclear accumulation and increased MIB-1
labeling index were seen in 4 cases. DNA ploidy analysis showed aneuploid pattern
in 2 of 9 cases. The mean patient follow-up was 3.5 years (range, 0.5-10.6
years); 2 patients had recurrent nephrogenic metaplasia, and the remainder were
alive without recurrence or urothelial carcinoma. CONCLUSIONS: Atypical
nephrogenic metaplasia is benign; it occasionally displays substantial cytologic
abnormalities of no apparent clinical significance. Awareness of the spectrum of
cytologic changes within this entity is critical to prevent overdiagnosis of
cancer and avoid unnecessary treatment. There is no direct evidence that links
atypical nephrogenic metaplasia to cancer.
PMID- 10679656
TI - Evaluation of cell proliferation, epidermal growth factor receptor, and bcl-2
immunoexpression as prognostic factors for patients with World Health
Organization grade 2 oligodendroglioma.
AB - BACKGROUND: Prognostic factors in oligodendrogliomas are an area of controversy
in neuropathology. Although grading and the study of some morphologic variables
may be of value as prognostic parameters, the variability of postoperative
disease free survival in patients with World Health Organization Grade 2
oligodendroglioma indicates that the biologic behavior of this entity remains
unknown. The objective of the current study was to evaluate immunoexpression of
the proliferation index (PI), epidermal growth factor receptor (EGFR), and bcl-2
as prognostic factors in patients with Grade 2 oligodendroglioma. METHODS: In a
series of 19 cases of pure Grade 2 oligodendroglioma, we assessed the mitotic
count, labeling index for MIB-1 and PCNA, and immunoreactivity for EGFR and bcl-2
with semiquantitative parameters and compared these with postoperative disease
free survival. Statistical analyses using the Cox-Mantel nonparametric test and
Spearman correlation coefficient were used to evaluate the data. RESULTS: Disease
free survival was significantly shorter when the MIB-1 PI was > 5% (P = 0.0096)
and the PCNA PI was > 9% (P = 0.00011) and when mitoses were observed (P =
0.00004). The paired variables also were found to correlate: MIB-1 versus PCNA (P
= 0.04), MIB-1 versus mitotic count (P = 0.0184), and PCNA versus mitotic count
(P = 0.0079). In all cases, there was immunoreactivity for EGFR; conversely, all
cases were negative for bcl-2 in the cells with an oligodendrocyte phenotype.
CONCLUSIONS: The PI was found to correlate with the postoperative disease free
survival in patients with Grade 2 oligodendroglioma; therefore, the authors
suggest a possible subdivision of Grade 2 oligodendrogliomas into two groups
based on the mitotic count and PI.
PMID- 10679657
TI - Stereotactic radiosurgery for recurrent ependymoma.
AB - BACKGROUND: Patients with recurrent intracranial ependymomas were evaluated to
assess local control, overall survival, and complications from stereotactic
radiosurgery (SRS). METHODS: Twelve patients (with a total of 17 tumors) with
recurrent ependymoma underwent SRS. Local failure was defined as tumor
progression within the prescription isodose volume, and marginal failure was
defined as tumor progression adjacent to the SRS prescription isodose volume.
Tumor progression away from the prescription volume was considered distant
failure. Eleven of the 12 patients had undergone previous resection and external
beam radiation therapy (46-56 Grays [Gy]; median, 54 Gy) before radiosurgery, and
1 patient had failure after complete resection alone. Age at SRS ranged from 5-56
years (median, 29 years). Three patients were female. The marginal tumor dose was
12-24 Gy (median, 18 Gy). One to 14 isocenters (median, 4 isocenters) were
utilized to irradiate volumes of 0.3-15.5 cm(3) (median, 3.2 cm(3)). RESULTS: The
duration of follow-up ranged from 2.5-60 months (median, 22.5 months). The median
overall survival after SRS was 3.4 years (range, 1.4-5 years). In-field local
control was achieved in 14 of the 17 tumor sites and estimated 3-year local
control was 68%. There were two in-field failures and one marginal failure.
Distant failure occurred in two patients. Two patients developed treatment
related complications after SRS. CONCLUSIONS: SRS provides good local tumor
control for patients with recurrent intracranial ependymoma and may have a
favorable impact on survival. SRS should be evaluated more extensively in the
initial treatment of patients with ependymoma to minimize local failure after
surgical management.
PMID- 10679658
TI - Mature results of a phase III randomized trial comparing concurrent
chemoradiotherapy with radiation therapy alone in patients with stage III and IV
squamous cell carcinoma of the head and neck.
AB - BACKGROUND: The current study presents mature results from a Phase III randomized
trial comparing radiation therapy and concurrent chemoradiotherapy in patients
with resectable American Joint Committee on Cancer Stage III and IV disease.
METHODS: One hundred patients were randomized to receive either radiation therapy
alone (Arm A) (at a dose of between 66-72 grays [Gy] at 1.8-2 Gy per day) and the
identical radiation therapy with concurrent chemotherapy (Arm B) (5-fluorouracil,
1000 mg/m(2)/day, and cisplatin, 20 mg/m(2)/day, both given as continuous
intravenous infusions over 4 days beginning on Days 1 and 22 of the radiation
therapy). Primary site resection was planned for patients with residual or
recurrent local disease. Cervical lymph node dissection was performed for
regional persistent disease or recurrence, or if N2-3 disease was present at the
time of presentation. RESULTS: After completing all therapy including surgery,
82% of the patients in Arm A and 98% of the patients in Arm B had been rendered
disease free (P = 0.02). At a median follow-up of 5 years (range, 3-8 years), the
5-year Kaplan-Meier projections for overall survival for Arm A versus Arm B were
48% versus 50% (P = 0.55). Kaplan-Meier projections for the recurrence free
interval were 51% versus 62% (P = 0.04), projections for a distant metastasis
free interval were 75% versus 84% (P = 0. 09), projections for overall survival
with primary site preservation were 34% versus 42% (P = 0.004), and projections
for local control without surgical resection were 45% versus 77% (P < 0.001).
Salvage surgery proved to be successful in 63% and 73%, respectively, of the Arm
A and Arm B patients with primary site failure. Unrelated death while free of
disease occurred in 22% and 32%, respectively, of Arm A and Arm B patients (P =
0.26). CONCLUSIONS: The addition of concurrent chemotherapy to definitive
radiation in patients with resectable Stage III and IV squamous cell carcinoma of
the head and neck improves the likelihood of disease clearance, a recurrence free
interval, and primary site preservation. However, overall survival does not
appear to be improved, reflecting both effective surgical salvage after local
recurrence and competing causes of death.
PMID- 10679659
TI - The origins of multiple squamous cell carcinomas in the aerodigestive tract.
AB - BACKGROUND: Chemoprevention and cessation of smoking and alcohol may prevent
development of multiple tumors (MTs) in the aerodigestive tract if new MTs arise
independently, but they are of no benefit if MTs are due to migration of an
already transformed clone of tumor cells. This issue was addressed in this study
by investigation of the clonality among MTs. METHODS: Mutation analysis of the
entire coding region of p53 and loss of heterozygosity (LOH) pattern analysis of
microsatellite markers on chromosome arms 3p, 9p, and 17p are promising for the
investigation of clonality. In the first part of this study, the authors
established the variability and stability of these clonal markers by comparing
primary head and neck squamous cell carcinomas (HNSCCs) with their metastases. In
the second part of this study, the authors evaluated nine patients with multiple
HNSCCs using these markers. In the final part, the authors illustrate the use of
these clonal markers in 11 patients for whom there was diagnostic uncertainty as
to whether their second squamous cell carcinoma was either a new primary tumor, a
metastasis, or a recurrence. RESULTS: Both p53 gene mutations and LOH patterns
were stable during tumor progression. Furthermore, the variability of p53 gene
mutations was high. More than 90% of the tumors contained a p53 mutation. A
particular mutation never occurred more than twice in a total of 69 primary
HNSCCs. Five of 69 cases presented a common mutation. In contrast, LOH patterns
showed less variability; they were identical in 5 of 16 cases. The metachronous
HNSCCs from nine patients all showed different p53 mutations, and in the three
cases that were subjected to LOH analysis different patterns were observed. All
11 patients for whom there was diagnostic uncertainty about the origin of their
second squamous cell carcinoma could be categorized as having multiple primary
tumors, disseminated disease, or recurrent disease. CONCLUSIONS: Metachronous
HNSCCs at different locations are not clonally related and thus have not
developed from the migration of tumor cells.
PMID- 10679660
TI - Bone marrow staging of patients with non-Hodgkin lymphoma by flow cytometry:
correlation with morphology.
AB - BACKGROUND: Immunophenotypic analysis is an established tool in the diagnosis and
classification of many hematolymphoid disorders; however, the role of flow
cytometry (FC) in detecting bone marrow involvement during the staging of non
Hodgkin lymphoma (NHL) has yet to be defined. METHODS: The authors
retrospectively analyzed 157 staging and 70 restaging bone marrow biopsies on
which morphologic and FC analyses were performed; these biopsies were taken from
195 consecutive patients. Bone marrow biopsies were blindly and independently
reviewed and determined to be positive, negative, or suspicious for morphologic
involvement by NHL, with disagreements settled by a third reviewer. A selected
panel of monoclonal antibodies was used to determine whether bone marrow
involvement was immunophenotypically positive (>5%), minimal (<5%), negative, or
nondiagnostic. RESULTS: FC and morphology agreed in 78% of cases (178 of 227: 129
both negative, 49 both positive) and were discrepant in 22% (49 of 227). Seven
percent (16 of 227) were morphologically positive but showed no evidence of
disease on FC, whereas 12% (27 of 227) were positive by FC but had no morphologic
involvement. Of the 162 morphologically negative or suspicious bone marrows, 27
were shown to be involved by FC, resulting in a false-negative detection rate of
17%. Most of these (22 of 27, 81%) had minimal detectable disease. Seven percent
of Stage I and 26% of Stage II NHL cases with negative staging bone marrow
morphologically were found to be involved by FC. CONCLUSIONS: Neither morphologic
examination of bone marrow biopsy specimens nor FC alone is adequate to detect
all cases of NHL with bone marrow involvement. FC is most sensitive for detecting
minimal bone marrow lymphoma, whereas morphology will detect most cases in which
involvement is >5%. Cases of early stage NHL with morphologically negative bone
marrow could potentially be restaged as Stage IV on the basis of FC results. The
clinical importance of minimal bone marrow involvement by NHL needs further
evaluation.
PMID- 10679661
TI - Assessment of the need for palliative care as perceived by individual cancer
patients and their families: a review of instruments for improving patient
participation in palliative care.
AB - BACKGROUND: Palliative care should fit the needs of individual cancer patients
and their families. Instruments can help to improve needs assessment. This review
evaluates questionnaires for the systematic assessment of needs experienced by
individual cancer patients for help, care, or support, as well as the needs of
their family members. METHODS: The MEDLINE and PsycLIT data bases were searched
systematically. Questionnaires were evaluated by reviewing their contents and
estimating their validity, reliability, and feasibility for use in caregiving
practice. RESULTS: Analysis of the 471 articles identified from the searches
yielded 9 questionnaires for the assessment of patients' needs and 6
questionnaires for the assessment of family members' needs. Most of these
instruments were carefully constructed; their validity and reliability were
satisfactory and well documented. However, in most questionnaires the needs for
care were confounded by satisfaction with care, and the problems experienced by
patients. Only one questionnaire for patients specifically addressed the need for
help; none for family members was so specific. Data on the feasibility of
questionnaires for use in regular care were scarce. Issues frequently omitted
were spiritual issues, the personal needs of family members, and the continuity
of care. CONCLUSIONS: None of the instruments the authors found was complete for
all dimensions of palliative care. Most instruments were constructed for research
purposes and had not been tested for use in practical care. Further development
of practical instruments based on a theoretical concept of needs assessment seems
necessary. The feasibility of instruments for use in practical caregiving and
their effects on the quality of care needs further research.
PMID- 10679662
TI - The National Cancer Data Base Report on treatment patterns for hepatocellular
carcinomas: improved survival of surgically resected patients, 1985-1996.
AB - BACKGROUND: The Commission on Cancer data from the National Cancer Data Base
(NCDB) has previously reported data evaluating time trends in various cancers,
including such elements as stage of disease at diagnosis, treatment, and survival
for multiple tumor sites. In this report, data collected from 1985, 1986, 1990,
1991, 1995, and 1996 for primary hepatocellular carcinoma (HCC) tumors are
presented. METHODS: The data presented in this review were collected from
hospital cancer registries from across the U.S. Eight calls for data have yielded
a total 6.9 million cases for the years 1985-1996, including 1158 HCC cases in
1985-1986, 3319 cases in 1990-1991, and 5683 cases in 1994-1995 from hospital
cancer registries across the U. S. These data represent approximately 4.3%,
11.2%, and 14.8% of the estimated cases of carcinomas of the liver and biliary
tract diagnosed in the U.S. in each of the three respective time periods.
RESULTS: The outcome for patients diagnosed with HCC remains poor, with only 10%
of patients with American Joint Committee on Cancer Stage I disease surviving 5
years. Approximately 50% of patients received no therapy for their HCC, even
those with early stage disease. Over these three time periods, the use of
chemotherapy appears to have decreased. Among patients diagnosed with Stage II
and III disease a difference in survival was noted between those treated with
surgery only and those treated with chemotherapy only. Women appear to have a
limited survival advantage over men. CONCLUSIONS: In spite of an overall poor
prognosis, subsets of patients with HCC appear to benefit from surgical
resection/ablation of their tumor. The decreasing use of chemotherapy and the
early reports of newer ablative techniques (e.g., cryotherapy) suggest that other
treatment modalities are emerging. These NCDB data provide a baseline for HCC
treatment from which prospective studies are being developed to assess the newer
treatments as well as the underlying causes.
PMID- 10679663
TI - The National Cancer Data Base Report on poor survival of U.S. gastric carcinoma
patients treated with gastrectomy: Fifth Edition American Joint Committee on
Cancer staging, proximal disease, and the "different disease" hypothesis.
AB - BACKGROUND: A high proportion of U.S. patients with gastric carcinoma do not
receive surgical treatment. To sharpen staging criteria and facilitate
comparisons with surgical series, an analysis of patients whose treatment
included gastrectomy was undertaken. In addition, to evaluate the "different
disease" hypothesis as an explanation for superior Japanese results, outcomes for
Japanese Americans were examined. METHODS: Data were obtained from National
Cancer Data Base (NCDB) reports of 50,169 gastric carcinoma cases diagnosed
during the years 1985-1996 and treated with gastrectomy. In addition to
demographic and treatment information, 5-year and 10-year relative survival rates
are presented, with stage defined according to fifth edition American Joint
Committee on Cancer (AJCC) staging procedures. RESULTS: Stage-stratified 5-year
and 10-year relative survival rates were as follows: Stage IA, 78%/65%; Stage IB,
58%/42%; Stage II, 34%/26%; Stage IIIA, 20%/14%; Stage IIIB, 8%/3%; and Stage IV,
7%/5%. Stage-stratified survival for Japanese Americans was higher. Males had a
poorer prognosis than females, and the male-to-female ratio for Japanese
Americans was lower. Proximal tumors were associated with a worse prognosis than
distal tumors; the proportion of Japanese Americans with proximal disease was
less than in the overall patient group. Japanese Americans underwent resection of
adjacent organs less frequently. In this series, adjuvant therapy did not
substantially affect survival. Overall, 20% were 10-year survivors; of these, 67%
were lymph node negative and 98% had = 8 involved lymph nodes. Five-year stage
stratified survival increased for cases with >/= 15 lymph nodes analyzed. Stage
migration was evident in cases with = 15 nodes examined. CONCLUSIONS: The
current AJCC/International Union Against Cancer TNM staging system fails to
accommodate the effect of proximal location on prognosis. Largely because
Japanese Americans present with fewer proximal tumors, have a lower male-to
female ratio, and undergo adjacent organ resection less frequently, stage-
stratified survival for Japanese Americans appears to be superior. In the U.S.,
surgical undertreatment of patients with this disease appears to be a problem.
PMID- 10679664
TI - National Cancer Data Base survey of breast cancer management for patients from
low income zip codes.
AB - BACKGROUND: The National Cancer Data Base (NCDB), a joint project of the American
College of Surgeons Commission on Cancer and the American Cancer Society, is a
cancer management and outcomes data base for health care organizations. It
provides a comparative summary of patient care that is used by participating
hospitals and communities for self-assessment. The most current (1995-1996)
breast cancer data on patients from low income zip codes are described here.
METHODS: Since 1989, eight Calls for Data have been issued, yielding a total of
191,714 reports of non-Hispanic white patients with breast cancer for the years
analyzed, 1995-1996. A total of 1961 hospital cancer registries have participated
in at least one of the Calls for Data. RESULTS: A diverse range of breast cancer
cases was reported from a variety of geographic locations and medical care
environments. There were general similarities in the treatment of patients from
the different income groups; however, some differences were reported. Among
patients from lower income zip codes, 60.7% were age 60 years or older, compared
with 55.1% from other income zip code groups. The AJCC stage distribution was
reported as less favorable for patients from low income zip codes than for other
patients. The percentage of patients from low income zip codes diagnosed as Stage
0 or I was 51.2%, compared with 55.9% of patients from the other income zip
codes. Of patients from lower income zip codes, 12.1% were reported to have Stage
III or IV disease, compared with 10.0% of patients from other income zip codes.
Patients from low income zip codes received less tissue-sparing surgery. Of
patients from low income zip codes, 14.9% received partial mastectomy with or
without radiation or systemic therapy, compared with 18.3% of patients from other
income zip codes. The percentage of patients from low income zip codes who
received a partial mastectomy with axillary lymph node dissection was 23.3% for
patients from other income zip codes, the percentage was 30.5%. Conversely, 49.8%
of patients from lower income zip codes received a modified radical mastectomy,
compared with 40.5% of patients from other income zip codes. CONCLUSIONS: Further
improvements in the early diagnosis and surgical treatment of low income patients
can probably be achieved. Programmatic activities that further explain or reduce
the apparent nonpreferred treatment of some low income patients should be
encouraged.
PMID- 10679665
TI - Consensus Conference on the Treatment of In Situ Ductal Carcinoma of the Breast,
April 22-25, 1999.
PMID- 10679666
TI - Report on Prostate Cancer Tumor Marker Workshop 1999.
PMID- 10679667
TI - Multiple chondromatous hamartomas of the lung: a case report and review of the
literature with special reference to Carney syndrome.
PMID- 10679668
TI - Author reply
PMID- 10679669
TI - Trilateral retinoblastoma: is the location of the intracranial tumor important?
PMID- 10679670
TI - Author reply
PMID- 10679671
TI - Analysis of apatite layers on glass-ceramic particulate using FTIR and FT-Raman
spectroscopy.
AB - A nucleation and crystallization schedule was adapted to produce 40% crystalline
Bioglass ceramic particulates. These particles were placed in a dynamic
environment in a simulated physiologic solution (SBF-9) for time periods ranging
from 10 min to 7 days. Fourier transform Raman spectroscopy (FT-Raman) and
infrared spectroscopy (FTIR) were used to analyze the apatite layer formation on
the particulates. FTIR determined that amorphous apatite formation took place
within 2 h, with the appearance of crystalline apatite in 14 h. The vibrational
frequencies obtained through FT-Raman were equivalent to those obtained using
FTIR. These analyses showed that a fully crystallized apatite layer was present
on the particulate after 3 days of exposure in SBF solution. These findings are
consistent with those associated with amorphous Bioglass particles.
PMID- 10679672
TI - Hyaluronan-based biopolymers as delivery vehicles for bone-marrow-derived
mesenchymal progenitors.
AB - The tolerability and safety of hyaluronan-based three-dimensional scaffolds as a
culture vehicle for mesenchymal progenitor cells was investigated in this pilot
study. The proliferation patterns and extracellular matrix production of rabbit
and human mesenchymal, bone-marrow-derived progenitors first were characterized
in vitro. Subsequently rabbit autologous cells were cultured in this hyaluronan
based scaffold and implanted in a full-thickness osteochondral lesion. In vitro
histologic findings showed that mesenchymal progenitor cells adhered and
proliferated onto the hyaluronan-derived scaffold. Human stem cells were shown to
produce the main extracellular matrix molecules, accompanied by an occasional
synthesis of mature type II collagen. In vivo data demonstrated that the
biomaterial, with or without mesenchymal progenitors, did not elicit any
inflammatory response and was completely degraded within 4 months after
implantation. With regard to the efficacy of this cell therapy, even among the
small number of animals tested there was histologic evidence that lesions filled
with the biomaterial, either seeded or unseeded with cells, achieved a faster and
better healing compared to empty controls. The present data suggest that the
hyaluronan-based scaffolds are well tolerated and safe and may be a valuable
delivery vehicle for tissue engineering in the repair of articular cartilage
defects.
PMID- 10679673
TI - Adsorption of human IgG on Cu(2+)-immobilized cellulose affinity membrane:
preliminary study.
AB - Immobilized metal ion affinity chromatography (IMAC) is widely used. Transition
metal ions have a high affinity to some peptide sequences. We have studied the
selective adsorption of human IgG from a mixture of albumin, gamma-globulin,
fibrinogen, and IgG onto Cu(2+) ion-immobilized cellulose membrane. Although
Cu(2+) ligand is selective to IgG, in general gamma-globulins also are adsorbed.
The simplicity and lower cost of Cu(2+) ion-immobilized cellulose membranes may
be useful for removing IgG from blood.
PMID- 10679674
TI - Quantitative evaluation of cell attachment to glass, polystyrene, and fibronectin
or collagen-coated polystyrene by measurement of cell adhesive shear force and
cell detachment energy.
AB - Quantitative evaluation of a material's affinity for cells is essential to
understanding cell-material interaction inside a body and it is also necessary
for the development of new biomaterials with superior biocompatibility. In the
present study, the shear force and the total energy necessary to detach a single
murine fibroblast L929 adhering to glass, polystyrene, and fibronectin- or
collagen-coated polystyrene were measured directly by applying a lateral force,
using a cantilever, to the cell. The projected area of the cell was also
measured, and then cell adhesive shear strength and cell detachment surface
energy were determined by dividing the shear force and the total energy by the
area. Among these four materials, the cells on collagen-coated polystyrene have
the highest cell adhesive shear strength and cell detachment surface energy (1500
Pa and 29 pJ on average, respectively), followed by the cells on fibronectin
coated polystyrene (1000 Pa and 16 pJ, respectively). The cells on glass and
polystyrene had almost the same cell adhesive shear strength and cell detachment
surface energy (420-670 Pa and 7-11 pJ, respectively). These observations suggest
that cell adhesive shear strength and cell detachment surface energy depend on
the number of the bindings between the cell and a material's surface rather than
on the strength of each binding.
PMID- 10679675
TI - Osseointegration of composite calcium phosphate bioceramics.
AB - The resistance of macroporous calcium phosphate ceramics to compressive strength
generally is low and depends on, among other factors, porosity percentage and
pore size. A compromise always is adopted between high porosity, required for a
good integration, and mechanical strength, which increases with material density.
We improved the strength of macroporous calcium phosphate ceramics of
interconnected porosity by filling the pores with a highly soluble, self-setting
calcium phosphate cement made of TCP and DCPD. Cylinders of the resulting
material were implanted in sheep condyles and subjected to histological analysis
after 20, 60, and 120 days. Microradiographs were made of the histological
sections. The control material consisted of ceramic that had not been loaded with
cement. Progressive ingrowth of bone into the ceramic pores occurred as the
cement was degraded during the first implantation period. Marked degradation of
the cement was apparent after 2 months, with fragmentation of the cement in most
of the pores and the presence of bone tissue between the fragments. All the
cement had been replaced by bone after 4 months. Some fragments of cement still
were embedded in the newly formed bone. There was no significant difference
between the integration of loaded and nonloaded ceramics. Filling the macroporous
ceramic pores with a calcium phosphate cement significantly improved the
mechanical strength of these ceramics without modifying their integration in the
healing bone.
PMID- 10679676
TI - Ion chromatographic determination of metals in biocompatibility testing.
AB - The increasing numbers of materials used in surgical implants require a wide
spectrum of tests to evaluate their biocompatibility. The release of metals is an
important additional feature for determining the suitability for clinical
applications of biomaterials such as ceramics and metals. Due to the difficulty
of performing time-consuming experiments in vivo, one approach for rapidly
determining the suitability of biomaterials and their interactions with the
tissues with which they will come in contact is to perform in vitro tests, based
on cell culture analysis, using solutions that reproduce the cleavage and binding
capabilities of body fluids and tissues. The present work reports on the
application of ion chromatography to the simultaneous determination of some metal
ions in a few biologic media. Agar-Agar solution, "199 medium, " and betadine and
Schiff's reagents were selected as some of the most representative biologic
simulating solutions. A method is recommended for the pretreatment of the sample
with minimal reagent addition since it is very rich in organic compounds and
cannot be analyzed without pretreatment. The proposed procedure requires the
sample to be subjected to oxidative UV photolysis for about 60 min in an UV
digester at 85 degrees +/- 5 degrees C, followed by the ion chromatographic
determination. Lead (II), cadmium (II), iron (III), copper (II), nickel (II),
zinc (II), and cobalt (II) simultaneously were determined at microg/L levels.
PMID- 10679677
TI - Human chondrocyte proliferation and matrix synthesis cultured in Atelocollagen
gel.
AB - To evaluate the potential of Atelocollagen gel as a carrier for chondrocyte
transplantation, histological and biochemical characteristics of the chondrocytes
in gel culture were compared with those in conventional monolayer cultures.
Articular chondrocytes from 20 patients were isolated by enzyme digestion,
embedded in Atelocollagen gel, and cultured for up to 4 weeks. The effects on
proliferation, morphological changes, and synthesis of proteoglycans were
analyzed by cell counts, light and electron microscopy, and measurement of
isomers of chondroitin sulfates. Chondrocytes embedded in the Atelocollagen gel
gradually proliferated and produced chondroitin 6-sulfate, maintaining the
chondrocyte phenotype for up to 4 weeks. In contrast, although monolayer
chondrocytes increased in number, most could be characterized as being fibroblast
like cells with a reduced capability of producing chondroitin 6-sulfate. The
results suggest that Atelocollagen gel permitted a gradual proliferation and
matrix synthesis of chondrocytes and maintaining its phenotype. Atelocollagen gel
represents an important carrier for the clinical application of cultured
chondrocyte transplantation for repair of cartilage defects.
PMID- 10679678
TI - Heparin-carrying polystyrene to mediate cellular attachment and growth via
interaction with growth factors.
AB - Various sugar-carrying polystyrenes (PSs), which consist of synthetic styrene and
sugar moieties, are glycoconjugates that are able to attach to polymeric
surfaces. Heparin-carrying PS (HCPS) is especially able to retain the binding of
heparin-binding growth factors (GFs) such as vascular endothelial GF 165
(VEGF(165)) or fibroblast GF 2 (FGF-2). Human skin fibroblast cells, human
coronary smooth muscle cells, and human coronary endothelial cells have good
adherence to the HCPS-coated plate. The growth rate of fibroblast cells on HCPS
coated plates is higher than or comparable to fibronectin-coated, gelatin-coated,
or tissue culture treated plates, and the HCPS coating inhibits the growth of
smooth muscle cells. On the other hand, the growth rate of endothelial cells on
HCPS-coated plates in the presence of either VEGF(165) or FGF-2 is comparable to
that on fibronectin-coated, gelatin-coated, and tissue culture treated plates.
Endothelial cells grow at a higher rate on HCPS-coated plates retained with
either VEGF(165) or FGF-2 than on the other coated plates. These results indicate
that growth of various cells can be controlled by the HCPS coating, thereby
retaining the bioactivity of molecules such as heparin-binding GFs. Thus, HCPS
coated surfaces control selective growth of various cells.
PMID- 10679679
TI - Use of glass slides coated with apatite-collagen complexes for measurement of
osteoclastic resorption activity.
AB - This study was designed to evaluate the use of apatite-collagen complexes (ACC)
coated onto glass slides for measurement of osteoclastic resorption activity. ACC
coated glass slides were prepared by immersion in beta-glycerophosphate solution
for 7-14 days after glass slides coated with type I collagen had been treated
with alkaline phosphatase and phosvitin. Osteoclast-containing cell suspensions
were prepared from the long bones of 1-day-old rabbits and were seeded in medium
199 (containing 10% FBS) onto ACC-coated glass slides. After allowing the cells
to attach for 1.5 h, the glass slides were incubated for periods of up to 96 h.
The cells were observed by scanning electron microscopy and cytochemically for
tartarate resistant acid phosphatase (TRAP) activity. Some slides were treated
with FITC-phalloidin and anti-type I collagen antibody. TRAP-positive
multinucleated cells were located in transparent spaces on the glass slides.
These spaces did not stain immunohistochemically with anti-type I collagen
antibody. Podosome formation was observed in the multinucleated cells facing the
edge of the transparent spaces. The scanning electron microscopy demonstrated
well-spread large cells located on the flattened surface on apatite particles
covering the glass surface. Our results suggest that osteoclasts could resorb the
apatite particles and coated collagen on the glass slide. The resorption lacunae
appeared as transparent spaces, and the cytoskeleton of resorbing osteoclasts was
observed in these spaces. ACC-coated glass slides could be useful for
investigating the function and metabolic activities of osteoclasts.
PMID- 10679680
TI - Plasma-deposited membranes for controlled release of antibiotic to prevent
bacterial adhesion and biofilm formation.
AB - Bacterial infection on implanted medical devices is a significant clinical
problem caused by the adhesion of bacteria to the biomaterial surface followed by
biofilm formation and recruitment of other cells lines such as blood platelets,
leading to potential thrombosis and thromboembolisms. To minimize biofilm
formation and potential device-based infections, a polyurethane (Biospan) matrix
was developed to release, in a controlled manner, an antibiotic (ciprofloxacin)
locally at the implant interface. One material set consisted of the
polyetherurethane (PEU) base matrix radiofrequency glow discharge plasma
deposited with triethylene glycol dimethyl ether (triglyme); the other set had an
additional coating of poly(butyl methyacrylate) (pBMA). Triglyme served as a
nonfouling coating, whereas the pBMA served as a controlled porosity release
membrane. The pBMA-coated PEU contained and released ciprofloxacin in a
controlled manner. The efficacy of the modified PEU polymers against Pseudomonas
aeruginosa suspensions was evaluated under flow conditions in a parallel plate
flow cell. Bacterial adhesion and colonization, if any, to the test polymers were
examined by direct microscopic image analysis and corroborated with destructive
sampling, followed by direct cell counting. The rate of initial bacterial cell
adhesion to triglyme-coated PEU was 0. 77%, and to the pBMA-coated PEU releasing
ciprofloxacin was 6% of the observed adhesion rates for the control PEU. However,
the rate of adherent cell accumulation due to cell growth and replication was
approximately the same for the triglyme-coated PEU and the PEU controls, but was
zero for the pBMA-coated PEU releasing ciprofloxacin.
PMID- 10679681
TI - In situ gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions and
degradation thereof.
AB - Aqueous solutions of poly(ethylene glycol-b-[DL-lactic acid-co-glycolic acid]-b
ethylene glycol) (PEG-PLGA-PEG) triblock copolymers form a free-flowing sol at
room temperature and become a gel at body temperature. In this study, in situ gel
formation was investigated in rats. Upon subcutaneous injection of 33 wt %
aqueous solutions of PEG-PLGA-PEG triblock copolymer into rats, transparent gels
were observed. The gel showed good mechanical strength and the integrity of gels
persisted longer than 1 month. The gel underwent degradation by hydrolysis and
turned opaque. Degradation study showed preferential mass loss of PEG-rich
segment from the in situ formed gel. Number average molecular weight determined
by gel permeation chromatography decreased from 3300 to 1900 and 30% mass loss
was observed over 1 month.
PMID- 10679682
TI - Preparation, solubility, and cytocompatibility of zinc-releasing calcium
phosphate ceramics.
AB - Zinc is an essential trace element with stimulatory effects on bone formation.
Therefore, zinc was doped into beta-tricalcium phosphate to develop zinc
releasing biomaterials to promote bone formation. The zinc-doped beta-tricalcium
phosphate, beta-tricalcium phosphate, and hydroxyapatite powders were mixed at a
(Ca+Zn)/P molar ratio of 1.60, followed by sintering into a dense body at 1100
degrees C for 1 h. The sintered body was a composite ceramic consisting of zinc
doped beta-tricalcium phosphate and hydroxyapatite phases. The composite ceramic
contained zinc oxide when the zinc content was higher than 1.20 wt %. The
composite ceramic released zinc under pseudophysiological conditions. However,
the release of calcium and phosphate decreased with an increase in zinc content
in a range higher than 0.12 wt % owing to a decrease in solubility of the zinc
doped beta-tricalcium phosphate phase. Proliferation of osteoblastic MC3T3-E1
cells was significantly increased on the composite ceramic with a zinc content
from 0.6 to 1.20 wt %, compared with those without zinc. When the zinc content
was higher than 1.20 wt %, release of zinc from the zinc oxide caused
cytotoxicity. Therefore, the zinc content of the composite ceramic must be <1.20
wt %.
PMID- 10679683
TI - Stimulatory effect of zinc-releasing calcium phosphate implant on bone formation
in rabbit femora.
AB - Although hydroxyapatite (HAP) and tricalcium phosphate (TCP) are currently used
as bone graft substitutes or coatings on metallic prostheses because of their
excellent biocompatibility and osteoconductivity, they do not stimulate bone
formation or inhibit bone resorption. Zinc, an essential trace element in many
animals, has a direct specific proliferative effect on osteoblastic cells and has
a potent and selective inhibitory effect on osteoclastic bone resorption in
vitro. Therefore, zinc-containing beta-tricalcium phosphate (ZnTCP) ceramics and
composite ceramics of ZnTCP and HAP (ZnTCP/HAP) were implanted in the femora of
New Zealand White rabbits for 4 weeks to promote bone formation. The implants
were sintered ceramics with zinc contents of 0 (control), 0.063, 0.316 and 0.633
wt %. Histological and histomorphometrical investigation of the undecalcified
sections revealed an increase by 51% (p =.0509) in the area of newly formed bone
around the ZnTCP/HAP implants of 0. 316 Zn wt % compared with the control. Plasma
zinc concentration was unchanged. An increased bone resorption on the endosteal
surface was observed when ZnTCP and ZnTCP/HAP of 0.633 Zn wt % were implanted. To
promote bone formation, the optimum zinc content of the calcium phosphate
ceramics was therefore 0.316 wt %.
PMID- 10679684
TI - Restoration of segmental bone defects in rabbit radius by biodegradable capsules
containing recombinant human bone morphogenetic protein-2.
AB - Recombinant human bone morphogenetic protein-2 (rhBMP-2) was encapsulated in
biodegradable poly(DL-lactide-co-glycolide) (PLGA) capsules to regenerate bone by
controlling the release rate of rhBMP-2. The rhBMP-2/PLGA capsules containing 12
microg of rhBMP-2 were implanted in seven 15-mm segmental defects of rabbits
radii to examine the healing capacity of the rhBMP-2/PLGA capsules. For the
control group, four segmental defects were left empty and two were implanted with
ghost PLGA capsules. Healing of the defects was followed for 24 weeks and
periodically evaluated by radiographs and histological examination. Mechanical
testing was applied to three regenerated bone samples at 24 weeks postoperatively
when the mature cortex was observed. Mechanical properties of regenerated bone
were not significantly different from normal intact bone statistically.
Histologically, the rhBMP-2/PLGA capsules disappeared completely during the
process of bone regeneration. These results increased possibilities for clinical
application of rhBMP-2/PLGA capsules.
PMID- 10679685
TI - High-resolution electron microscopy study of synthetic carbonate and aluminum
containing apatites.
AB - Aluminum (Al)-containing calcium-deficient carbonated hydroxyapatites were
produced by a precipitation method from aqueous solution with carbonate (0-6.1%)
and aluminum (0.1-0.5%) concentrations close to those found in biological
materials. Two series of apatites were prepared: one at pH 7.0 and another at pH
9. 0. High-resolution electron microscopy has shown that many of them possess
structural defects such as screw dislocations, grain boundaries, and central
defects. Samples with high carbonate content and high water and high Al(3+)
content had a high amount of structural defects. Accordingly, a sample (7Al1)
with a relatively high carbonate content (6.1%) and a sample (7Al6) without
carbonate but with a relatively high water (2.0 mol) and Al(3+) content (0. 39%)
presented the highest amount of structural defects, 54% and 47%, respectively. A
sample (7Al13) with a low level of crystalline water (1 mol) and low carbonate
(2.5%) showed a small amount of defects. The presence of water associated with
Al(3+) induced a high number of crystals having a central defect with a great
similarity to the so-called water layer of octacalcium phosphate (OCP). Observed
images of all these crystals have shown good correspondence with the computer
simulated image based on the crystal structure of hydroxyapatite, indicating that
the addition of Al(3+) and carbonate does not perturb the apatitic structure.
PMID- 10679686
TI - Initial adhesion and surface growth of Staphylococcus epidermidis and Pseudomonas
aeruginosa on biomedical polymers.
AB - The infection risk of biomaterials implants varies between different materials
and is determined by an interplay of adhesion and surface growth of the infecting
organisms. In this study, we compared initial adhesion and surface growth of
Staphylococcus epidermidis HBH(2) 102 and Pseudomonas aeruginosa AK1 on
poly(dimethylsiloxane), Teflon, polyethylene, polypropylene, polyurethane,
poly(ethylene terephthalate), poly(methyl methacrylate), and glass. Initial
adhesion was measured in situ in a parallel plate flow chamber with
microorganisms suspended in phosphate-buffered saline, while subsequent surface
growth was followed in full and in 20 times diluted growth medium. Initial
adhesion of both bacterial strains was similar to all biomaterials. In full
growth medium, generation times of surface growing S. epidermidis ranged from 17
to 38 min with no relation to wettability, while in diluted growth medium
generation times increased from 44 to 98 min with increasing surface wettability.
For P. aeruginosa no influence of surface wettability on generation times was
observed, but generation times increased with decreasing desorption rates,
maximal generation times being 47 min and minimal values down to 30 min.
Generally, generation times of adhering bacteria were shorter than of planktonic
bacteria. In conclusion, surface growth of initially adhering bacteria is
influenced by biomaterials surface properties to a greater extent than initial
adhesion.
PMID- 10679687
TI - Neural and connective tissue response to long-term implantation of multiple
contact nerve cuff electrodes.
AB - The objective of this study was to characterize the tissue response to multiple
contact spiral nerve cuff electrodes implanted on the sciatic nerve of seven cats
for 28-34 weeks. The cuffs were surrounded by fibrous tissue encapsulation
consisting of foreign body cells, collagen, and fibroblasts. Focal areas of
abnormal neural morphology including perineurial thickening, endoneurial
fibrosis, thinly myelinated axons, and focal reduction in the density of
myelinated axons were noted in five of seven nerves. In three implants, the
percutaneous lead cable was destroyed by the animal pulling on the external
leads. Morphological changes were observed in two of three nerves from implants
sustaining no known animal induced trauma (group A), and in three of four nerves
from implants damaged by the animal pulling at the leads (group B). All nerves
appeared normal 2 cm proximal to the cuff. At the cuff level, small regions of
one fascicle in each of two nerves (both group B) exhibited abnormalities, while
the proximal and distal sections of both nerves were normal. Distal to the cuff,
small regions of seven fascicles distributed among three nerves (two group A, one
group B) exhibited abnormalities. These nerves were normal at the cuff level but
exhibited abnormalities in individual nerve branches distal to the cuff. The
incidence and characteristics of the morphological abnormalities at the cuff
level are consistent with those observed in previous studies of nerve cuff
electrodes, and support the hypothesis that spiral cuff electrodes can be
implanted with an internal diameter less than that of the nerve and expand to
accommodate the nerve without compression The pattern of morphological
abnormalities indicated that mechanical trauma had occurred at some time in the
past, and the distribution suggested animal intervention and the lead cable as
possible causes.
PMID- 10679688
TI - Implantation of recombinant human bone morphogenetic proteins with biomaterial
carriers: A correlation between protein pharmacokinetics and osteoinduction in
the rat ectopic model.
AB - This study was carried out to determine the effect of recombinant human bone
morphogenetic protein (rhBMP) pharmacokinetics (PK) on rhBMP-induced
osteoinductive activity. It was our working hypothesis that the PK of a rhBMP
significantly affects its osteoinductive activity. The PK of various rhBMPs
(rhBMP-2, rhBMP-4, rhBMP-6, and chemically modified rhBMP-2) implanted with four
biomaterial carries (Helistat, hDBM, Osteograf/N, and Dexon) was determined using
(125)I-labeled proteins in the rat ectopic assay. A select combination of rhBMP
and carriers then was evaluated in the rat ectopic assay for osteoinductive
activity using a semi-quantitative histologic scoring system. The results
indicate that initial protein retention is dependent on protein isoelectric point
(pI); proteins with a higher pI yielded a higher implant retention. Subsequent PK
was not strongly dependent on the pI or on the carrier. Because of the difference
in early retention, the rhBMP-carrier combinations exhibited a >100-fold
difference in implant-retained protein dose. When rhBMP-2 and rhBMP-4 were
implanted with the carriers, more rhBMP-2 was retained in an implant, and the
osteoinductive potency of rhBMP-2 typically was higher than rhBMP-4 at low
implantation doses. We conclude that protein pI plays a significant role in the
local retention of implanted rhBMP and that higher retention yields a higher
osteoinductive activity.
PMID- 10679689
TI - The study of surface transformation of pulsed laser deposited hydroxyapatite
coatings.
AB - Hydroxyapatite (HA) coatings generally exhibit very good biocompatibility owing
to their compositional resemblance to the natural hard tissue and to bioactive
properties that are directly related to surface transformations in physiological
fluids. In this study, two types of porous HA coatings produced with pulsed laser
deposition were tested with respect to their dissolution/reprecipitation in a
semidynamic simulated physiological solution. Coatings with higher porosity
produced with a 355-nm wavelength laser exhibited significant reprecipitation
earlier than those produced with a 266-nm wavelength laser. The dissolution of
the non-HA phases played a major role in the reprecipitation of HA-like material
as indicated by X-ray diffraction (XRD). The coatings' Ca/P ratio became closer
to the theoretical value of HA. The newly formed HA had imperfect crystal
structure and/or small crystal size as suggested by XRD. The reprecipitation
resulted in a very dense morphology as shown by scanning electron microscopy,
suggesting a mechanically strong structure after reprecipitation. Despite
undergoing dissolution and reprecipitation, the coatings showed sufficient
stability in the solution, as XRD and energy-dispersive X-ray studies indicated
no significant loss of the coatings. The stability of these HA coatings and their
ability to cause reprecipitation of HA in the simulated physiological solution
showed the potential of these coatings for clinical applications.
PMID- 10679690
TI - Structural and morphological study of pulsed laser deposited calcium phosphate
bioceramic coatings: influence of deposition conditions, laser parameters, and
target properties.
AB - Calcium phosphate (CaP) bioceramics, especially hydroxyapatite (HA), have been
used as coatings on implants owing to their biocompatible properties. The
commercial practice for applying HA coating, plasma spraying, has some
disadvantages which limit the long-term stability of the implants. Pulsed laser
deposition (PLD) is being investigated as an alternative technique. The purpose
of this research was to systematically study the effect of various parameters of
the PLD process on the properties of CaP coatings. In this study, three types of
HA targets and two laser wavelengths were used to make six categories of
coatings. Predominantly crystalline HA coatings were produced under all six
categories at optimum conditions, although small amounts of minor phases
sometimes were found. Sufficient coating/substrate bond strength was also
obtained. A wide variety of coating morphologies was obtained, from rather dense
and uniform to rough and porous. The important factors that affected the
morphology included target properties, vacuum level, deposition temperature, and
laser wavelength and energy density. PLD's ability to produce both amorphous and
crystalline, and both smooth/dense and rough/porous coatings may be a unique
advantage.
PMID- 10679691
TI - Foreign-body reaction to dermal sheep collagen in interferon-gamma-receptor knock
out mice.
AB - This study was performed to gain more insight into the role of interferon-gamma
(IFN-gamma), a potent macrophage activator, in the foreign-body reaction to
hexamethylenediisocyanate-crosslinked dermal sheep collagen (HDSC). Because the
results of earlier studies aimed at modulating the foreign-body reaction in AO
rats by local or systemic treatment with anti-IFN-gamma were not completely
unambiguous, we extended our investigations to IFN-gamma-receptor knock-out (KO)
mice. Several parameters (i.e., macrophages, giant cells, T-cells, B-cells,
granulocytes, expression of MHC class II, stroma formation, and degradation and
calcification of the biomaterial) were compared between wild-type (WT) and KO
mice. Remarkably, the foreign-body reaction was very similar in WT and KO mice.
In both, giant cells were formed, but in contrast to previous results in AO rats,
phagocytosis of HDSC bundles occurred hardly at all up to 9 weeks, and MHC class
II expression was minimal. Stroma formation and vascularization were high and
calcification occurred. T-cells comprised less than 1%; a few plasma cells were
present in the KO mice at later time points. Granulocytes, mainly eosinophils,
were present at all explantation time points. Because of the similar results in
WT and KO mice, we question whether IFN-gamma plays a role at all in the foreign
body reaction in mice.
PMID- 10679692
TI - In vitro stability of plasma-sprayed hydroxyapatite coatings on Ti-6Al-4V
implants under cyclic loading.
AB - The success of hydroxyapatite (HA)-coated Ti-6Al-4V implants relies on the long
term stability of HA coatings. In this study, the mechanical stability of plasma
sprayed HA coatings on Ti-6Al-4V implants under four-point cyclic bending was
systematically investigated in both air and simulated body fluid (SBF)
environments at room temperature. To have a clear view of the microscale damage
evolution, the surface morphology change of HA coatings during cyclic loading was
carefully examined by scanning electron microscopy at the same locations on the
coating surfaces after four-point bending for 4, 6.5, 8.5, and 10 million cycles.
Also, possible changes of other characteristics such as thickness, weight,
crystallinity, and residual stress of HA coatings were measured as a function of
loading cycles. Up to 10 million cycles of bending in air and SBF, we found no
significant microcracking or coating spalling on the surface of coatings, and no
significant changes in thickness, weight, crystallinity, or residual stress of
the plasma-sprayed HA coatings. The experiment results indicate that thickness
and crystallinity had no effects on the stability of the HA coatings. HA coating
resistance to the cyclic four-point bending might result from the stress
shielding effects of preexisting microcracks in the coatings.
PMID- 10679694
TI - Effect of external stresses on calcium phosphate glass investigated by IR
spectroscopy.
PMID- 10679693
TI - Processing cell-seeded polyester scaffolds for histology.
AB - Biodegradable 3-dimensional scaffolds of various morphologies are currently being
developed for tissue engineering. Poly(lactide-co-glycolide)s (PLGAs) of various
lactide to glycolide ratios are frequently used for such applications. Tissue
engineering involves an in vitro stage during which cells are seeded onto
scaffolds and allowed to settle and/or grow for various time periods. To assess
cell distribution and/or tissue formation throughout the scaffolds during this in
vitro stage, techniques such as confocal microscopy and magnetic resonance
imaging have been applied. However, such cultured scaffolds have been refractory
to histological evaluation because of numerous technical difficulties. We
describe a method to prepare histological sections of cell cultured PLGA
scaffolds for tissue engineering. The technique involves in situ labeling of
cultured scaffolds, infiltration of the scaffolds with a 10% poly(vinyl alcohol)
solution under a low vacuum, and cryosectioning of samples onto acid-treated
glass coverslips. Sections obtained with this technique show cell distribution
and cell-tissue morphology on the pore wall structures of entire centimeter-thick
scaffolds. This rapid and easy technique allows for fast evaluation of tissues
grown on biodegradable scaffolds.
PMID- 10679696
TI - Effect of hemodynamic conditions on sonographic measurements of peak systolic
velocity and arterial diameter in patients with peripheral arterial stenosis.
AB - PURPOSE: We measured changes in peak systolic velocity ratio and sonogaphic
vascular diameter during different hemodynamic conditions in patients with
femoral or iliac artery stenosis. METHODS: In 35 patients with isolated femoral
or iliac artery stenosis, prestenotic and intrastenotic peak systolic velocity
and inner vascular diameter were calculated using color Doppler sonography and
gray-scale sonography, respectively. The measurements were performed with the
patient at rest (baseline), after leg exercise, and again after oral
administration of 10 mg of the vasodilator nifedipine. RESULTS: The mean
prestenotic and intrastenotic peak systolic velocity and the peak systolic
velocity ratio (intrastenotic/prestenotic peak systolic velocity) were 70 +/- 31
cm/second, 360 +/- 130 cm/second, and 6.5 +/- 3.6 at baseline; 78 +/- 37
cm/second, 404 +/- 171 cm/second, and 6.6 +/- 4.2 after leg exercise; and 71 +/-
30 cm/second, 353 +/- 109 cm/second, and 5.9 +/- 3.2 after nifedipine
administration. The mean prestenotic and intrastenotic diameter and percentage of
diameter reduction were 5.9 +/- 3.2 mm, 2.3 +/- 1.1 mm, and 59 +/- 13% at
baseline; 4.8 +/- 2.4 mm, 2.0 +/- 1.3 mm, and 62 +/- 13% after leg exercise; and
5.9 +/- 2.9 mm, 2.5 +/- 1.0 mm, and 54 +/- 14% after nifedipine administration.
Only the difference in intrastenotic diameter after leg exercise was
significantly different from baseline. CONCLUSIONS: The peak systolic velocity
ratio in peripheral arterial stenosis seems to be relatively independent of the
hemodynamic conditions and cannot be used for investigations of vasomotion of
stenotic arterial segments during different hemodynamic conditions.
PMID- 10679697
TI - Cerebrovascular reserve capacity in patients with hyperlipidemia.
AB - PURPOSE: Because recent data are conflicting, it is not certain whether
hyperlipidemia is an independent risk factor for cerebrovascular diseases.
Decreased cerebrovascular reserve capacity refers to the decreased ability of the
cerebral arterioles to adapt in critical conditions and probably predicts a
higher risk of stroke. The aim of this study was to compare cerebrovascular
reserve capacity in hyperlipidemic patients and healthy controls using
transcranial Doppler sonography. METHODS: Thirty-four hyperlipidemic patients and
21 healthy controls were examined. With transcranial Doppler sonography, the mean
blood flow velocity in the middle cerebral artery was registered at rest and at
5, 10, 15, and 20 minutes after intravenous administration of 1,000 mg
acetazolamide. Cerebrovascular reactivity and reserve capacity were calculated
from mean blood flow velocities. Various laboratory measurements were also made
and assessed for correlation with resting cerebral blood flow velocity and
cerebrovascular reserve capacity. RESULTS: No significant differences could be
observed between controls and hyperlipidemic patients in cerebrovascular
reactivity or cerebrovascular reserve capacity. No correlation was found between
various laboratory measurements and resting cerebral blood flow velocity or
cerebrovascular reserve capacity. CONCLUSIONS: We could not demonstrate any
differences in cerebrovascular reserve capacity between hyperlipidemic patients
and healthy controls. Thus, the vasodilatory ability of the cerebral arterioles
seems to remain unchanged in this patient group and is not correlated with the
severity of hyperlipidemia.
PMID- 10679698
TI - Transabdominal pelvic sonography in the preoperative evaluation of patients with
congenital adrenal hyperplasia.
AB - PURPOSE: We assessed the clinical value of transabdominal pelvic sonography in
the preoperative evaluation of patients with congenital adrenal hyperplasia (CAH)
who required feminizing genitoplasty. METHODS: From 1987 to 1998, 31 patients
with female pseudohermaphroditism due to CAH underwent feminizing genitoplasty.
The median age of the patients was 9 months (range, 1-18 years). Radiologic
evaluation performed before surgical reconstruction included retrograde
genitography in the first 10 patients and sonographic examination in all 31
patients. Imaging was used to evaluate the anatomic positions and the length of
the vagina, whether the junction of the vagina and the urogenital sinus occurred
distal or proximal to the pelvic floor, and the presence of internal genitalia.
RESULTS: Abdominal sonography identified internal female genitalia in all 31
patients, identified the anatomic shape and position of the vagina in 30 patients
(97%), and confirmed the site of communication between the vagina and the
urogenital sinus relative to the pelvic floor in 28 patients (90%). Sonographic
findings were confirmed by intraoperative panendoscopy. Genitography was less
useful than sonography, identifying the site of communication between the vagina
and urogenital sinus in only 6 (60%) of 10 patients. CONCLUSIONS: In patients
with CAH undergoing vaginal reconstruction, sonography provides adequate
information about the anatomy of the vagina and urogenital sinus for surgical
decision-making.
PMID- 10679699
TI - Demonstration of gastric submucosal lesions by high-resolution transabdominal
sonography.
AB - PURPOSE: We evaluated the accuracy of high-resolution transabdominal sonography
(TAUS) in identifying and characterizing gastric submucosal masses previously
detected by endoscopy. METHODS: Patients given endoscopy for suspected submucosal
gastric lesions and 2 patients with gastric wall cysts were enrolled. Patients
underwent TAUS and then endoscopic sonography (EUS) on the same day, and the
sonographic results were compared with endoscopic and histologic findings.
RESULTS: Among 101 patients with gastric submucosal masses on endoscopy, TAUS
revealed a mass in 94 (93%); of these 94 patients, 60 underwent EUS. The final
diagnoses were 31 leiomyomas, 10 leiomyosarcomas, 13 ectopic pancreases, 2 cysts,
and 1 glomus tumor, 1 carcinoid tumor, 1 lipoma, and 1 fibroma. Leiomyomas (mean
size, 3.2 cm) and leiomyosarcomas (mean size, 7.1 cm) were shown sonographically
to originate from the muscular layer. Ectopic pancreases (mean size, 1.2 cm) were
shown to originate from the submucosal layer and had a homogeneously echogenic
pattern. Gastric cysts were found in the submucosal layer and were anechoic. The
glomus tumor and the carcinoid tumor were found in the muscular layer and were
hypoechoic. The lipoma and the fibroma were located in the submucosal layer and
were echogenic on TAUS. CONCLUSIONS: TAUS had a detection rate of 93% in
visualizing submucosal gastric masses previously identified by endoscopy. TAUS is
less invasive than EUS and can be used to follow submucosal gastric masses that
are not excised.
PMID- 10679700
TI - Sonographic detection of visceral adhesion in percutaneous drainage of afferent
loop small-intestine obstruction.
AB - To facilitate the percutaneous drainage of an afferent-loop small-intestine
obstruction, we used sonography to detect visceral adhesions and select a safe
puncture route. The portion of the small intestine that was fixed to the anterior
abdominal wall was sonographically identified by using a high-frequency
transducer to locate the area of restricted visceral sliding. The needle was then
inserted into the intestine. In 3 cases, we have found that this technique
improves the confidence of the physicians who perform the percutaneous drainage
and may help to minimize the risks associated with the percutaneous drainage.
PMID- 10679701
TI - Early prenatal sonographic diagnosis of twin triploid gestation presenting with
fetal hydrops and theca-lutein ovarian cysts.
AB - The presence of theca-lutein ovarian cysts in the early second trimester of
pregnancy is highly suspicious for a complete hydatidiform molar pregnancy but
can be seen in association with a partial mole. Theca-lutein cysts may occur
following hormonal stimulation for assisted reproductive techniques or in
association with multiple gestations. Rare causes include immune and nonimmune
fetal hydrops, maternal hypothyroidism, and triploid gestations. We report a case
of a monochorionic twin gestation in which prenatal sonography demonstrated
multiple anomalies and hydrops in each twin and bilateral theca-lutein ovarian
cysts. Triploidy in both twins and a partial hydatidiform mole were confirmed at
pathologic examination.
PMID- 10679702
TI - Sonographic detection of delayed small bowel perforations after blunt abdominal
trauma.
AB - Isolated perforations of the small bowel resulting from blunt abdominal trauma
are rare and difficult to diagnose because of their variable presentation,
especially when their appearance is delayed. We report 2 such cases that were
diagnosed by sonography and emphasize the usefulness of sonography in detecting
bowel injuries after blunt abdominal trauma.
PMID- 10679703
TI - Color Doppler sonography of uterine arteriovenous malformation.
AB - Arteriovenous malformation of the uterus is a rare but potentially life
threatening lesion. We report a case of arteriovenous malformation of the uterus
in a 19-year-old nulliparous woman. The diagnosis was made with color Doppler
sonography and was confirmed histologically. Color Doppler sonography helps
differentiate uterine arteriovenous malformation from other entities that have a
similar appearance on gray-scale sonograms.
PMID- 10679704
TI - Prenatal sonographic detection of a lipomeningocele as a sacral lesion.
AB - We present a case of a lipomeningocele in a newborn. Prenatal sonography revealed
dysraphia and a 3.8 x 4.3 cm, semisolid, echogenic mass that was continuous with
the sacral area and bulged posteriorly under the skin. The mass was diagnosed
after birth as a lipomeningocele based on the results of MRI. This diagnosis was
confirmed histologically.
PMID- 10679705
TI - Sonographic diagnosis of a small fistulous communication between a subphrenic
abscess and a perforated duodenal ulcer.
AB - We report a case of a fistula between a subphrenic abscess and a perforated
duodenal ulcer diagnosed by sonography and confirmed by CT. The sonographic
findings included a subphrenic fluid collection connected to the anterior aspect
of the superior duodenum by a nonpulsatile, anechoic tubular lesion. Manual
compression of the upper epigastrium resulted in movement of echogenic debris
from the antrum and superior duodenum through the fistulous tract into the
abscess.
PMID- 10679706
TI - Type I interferons and chronic inflammatory demyelinating polyneuropathy:
treatment or cause?
PMID- 10679707
TI - Mechanisms of paresthesias arising from healthy axons.
AB - Paresthesias are common manifestations of central and peripheral pathological
processes and are due to ectopic impulse activity in cutaneous afferents or their
central projections. Cutaneous afferents are more excitable than motor axons, due
to differences in their biophysical properties. These differences probably
include more persistent Na(+) conductance and inward rectification on cutaneous
afferents, properties which probably confer greater protection from impulse
dependent conduction failure but create a greater tendency to ectopic activity.
Ectopic discharges can be induced in normal afferents by four maneuvers:
hyperventilation, ischemia, release of ischemia, and prolonged tetanization. The
alkaline shift produced by hyperventilation selectively increases the persistent
Na(+) conductance, while the membrane depolarization produced by ischemia affects
both transient and persistent Na(+) channels. Postischemic and posttetanic
paresthesias occur when hyperpolarization by the Na(+)/K(+) pump is transiently
prevented by raised extracellular K(+). The electrochemical gradient for K(+) is
reversed, and inward K(+) currents trigger regenerative depolarization. These
mechanisms of paresthesia generation can account for paresthesias in normal
subjects and may be relevant in some peripheral nerve disorders.
PMID- 10679708
TI - Electrophysiological studies of myoclonus.
AB - As myoclonus is often associated with abnormally increased excitability of
cortical structures, electrophysiological studies provide useful information for
its diagnosis and classification and about its generator mechanisms. The EEG-EMG
polygraph provides the most essential information about the myoclonus of
interest. Jerk-locked back averaging and evoked potential studies combined with
recording of the long latency, long loop reflexes are useful to further
investigate the pathophysiology of myoclonus, especially that of cortical
myoclonus. A recent advance in magnetoencephalographic techniques has contributed
significantly to the elucidation of some of the cortical mechanisms underlying
myoclonus. Elucidation of physiological mechanisms underlying myoclonus in each
individual patient is important for selecting the most appropriate treatment of
choice.
PMID- 10679709
TI - Amyotrophic lateral sclerosis: early contributions of Jean-Martin Charcot.
AB - Amyotrophic lateral sclerosis is historically an important entity because its
manifestations involve distinct signs that can be correlated with gray and white
matter lesions at specific sites within the central nervous system. Working at
the end of the nineteenth century, the celebrated neurologist, Jean-Martin
Charcot, used this disorder as a prototypic example of the power of his research
method, termed "methode anatomoclinique." Using clinical cases and autopsy
material, he showed how anatomical lesions in the nervous system could be
accurately determined by the presence of carefully analyzed clinical signs.
Charcot's work on amyotrophic lateral sclerosis brought together neurological
entities formerly considered as disparate disorders, primary amyotrophy and
primary lateral sclerosis. In addition, these studies contributed to the
understanding of spinal cord and brain stem anatomy and the organization of the
normal nervous system. Because of Charcot's fundamental contributions, the eponym
"Charcot's disease" has been used internationally in association with amyotrophic
lateral sclerosis.
PMID- 10679710
TI - Nerve conduction studies in amyotrophic lateral sclerosis.
AB - We studied 137 ulnar nerves and abductor digiti minimi (ADM) muscles in 70
patients with amyotrophic lateral sclerosis (ALS), and correlated the results
with ADM strength graded on the Medical Research Council (MRC) scale, to address
the potential value of a standardized neurophysiological assessment of this nerve
muscle system. The ulnar nerves of 35 normal subjects matched for age, gender,
and height served as controls. Reduced compound muscle action potential (CMAP)
amplitude and area in the ADM muscle recordings correlated strongly with
weakness. Distal motor latency, proximal conduction time, and F-wave frequency
were abnormal with minimally detectable weakness. In weaker ADM muscles,
conduction velocities and F-wave latencies were also abnormal. Conduction block
was never observed and sensory potentials were normal. An "ALS neurophysiological
index" was derived from these ulnar nerve studies and consisted of the
expression: (CMAP amplitude/DML) x F frequency -, where F frequency was expressed
as the number of F responses recorded in 20 trials. This index was strongly
correlated with ADM weakness (r = 0.74, P < 0.001). Neurophysiological studies
restricted to a single nerve-muscle system, the ulnar nerve/ADM, appear
potentially useful in objectively assessing change in ALS.
PMID- 10679711
TI - Central scalp projection of the N30 SEP source activity after median nerve
stimulation.
AB - Conflicting results have been reported about abnormalities of the N30
somatosensory evoked potential (SEP) in movement disorders. In these studies, the
N30 amplitude was measured in the frontal scalp region. Our aim was to identify
the scalp electrodes recording the genuine activity of the N30 generator. In 18
subjects, we recorded the scalp SEPs from 19 electrodes and found a negative
potential around 30 ms reaching its maximal amplitude in the frontal region.
However, neither simple visual inspection of the frontal traces nor topographic
analysis could distinguish the N24 from the N30 component of the frontal
negativity. Brain electrical source analysis of SEPs showed that a four dipolar
source model could well explain the scalp SEP distribution. We calculated the
scalp field distributions of the source activities as modeled from the scalp
recordings and observed that the maximal field distribution reflecting the
activity of the N30 source was in the central region, whereas that reflecting the
N24 source activity was frontal. We conclude that the negative response recorded
around 30 ms in the central traces represents "genuine" N30 source activity,
whereas the frontal negativity, which is higher in amplitude, is a mixture of the
activities of both the N30 and N24 sources.
PMID- 10679712
TI - Quantitative EMG and motor unit recruitment threshold using a concentric needle
with quadrifilar electrode.
AB - According to Henneman's size principle, small motor units are recruited before
large ones. We used the electromyographic (EMG) signal decomposition technique to
determine the quantitative relationships between five motor unit action potential
(MUAP) parameters (amplitude, duration, area, thickness, and size index) and the
recruitment threshold of the motor units recruited up to 50% of the maximum
voluntary contraction in the first dorsal interosseous, biceps brachii, rectus
femoris, and tibialis anterior muscles of 5 healthy young men. In each muscle,
the amplitude, duration, area, and size index had significant, positive high
correlations with the motor unit recruitment thresholds. We conclude that the
size principle applies to recordings made with concentric needle EMG electrodes
under special recording conditions, and therefore that more importance should be
attached to the patient's contraction force during EMG examinations in order to
evaluate MUAPs for electrodiagnostic purposes.
PMID- 10679713
TI - Intraoperative monitoring of the inferior alveolar nerve during mandibular
sagittal-split osteotomy.
AB - In order to evaluate the risk of nerve injury and to prevent iatrogenic damage at
different stages of bilateral sagittal-split osteotomy (BSSO) of the mandible, we
monitored the function of the inferior alveolar nerve (IAN) continuously on both
sides in 13 orthognathic patients undergoing BSSO. The IAN was stimulated at the
mental foramen with two monopolar needle electrodes fixed to the dental splint,
and the orthodromic sensory nerve action potentials (SNAP) of the IAN were
recorded with a silver-wire electrode inserted near the oval foramen on each
side. The latencies, amplitudes, and sensory nerve conduction velocities at
baseline, after medial opening, sawing, splitting, eventual manipulation, and
fixation of the mandible were analyzed. The monitoring method functioned
technically well in 25 of 26 nerves. Both the surgical technique and the duration
of medial opening had conspicuous effects on the function of the IAN, which led
us to modify the medial approach. When finer instruments were used for retraction
and the duration of medial opening was shortened to less than 10 min, the SNAP of
the IAN was always preserved at this stage. Monitoring of the IAN also prevented
nerve injury during splitting and fixation. This technique for intraoperative
monitoring of the IAN seems to be a feasible and promising tool for objective
evaluation of intraoperative events and for prevention of nerve injury during
BSSO.
PMID- 10679714
TI - Evidence of inability to fully activate human limb muscle.
AB - The purpose of this study was to determine whether muscle activation level
estimated by twitch interpolation technique was different when an electrical
stimulus was applied during a dynamic force (DF; force rising) task from that
when the stimulus was applied during a static force (SF; constant force) task.
Fourteen subjects performed voluntary SF and DF contractions involving isometric
elbow flexion at seven voluntary force levels. At each level, the electrical
stimulation was applied to the surface of the biceps brachii muscle when the
force was steady (SF task) and when the force was rising (DF task). The voluntary
activation level of the biceps brachii muscle during the SF maximal voluntary
contraction (MVC) was 98.5% and that during the DF MVC task was significantly
lower (94.5%; P < 0.05). The motoneurons and/or muscle fibers may become more
excitable during the DF task so that the same stimulus can recruit those that are
otherwise less excitable during the SF task.
PMID- 10679715
TI - Expression of HLA-DR and its enhancing molecules in muscle fibers in
polymyositis.
AB - Polymyositis (PM) is an autoimmune inflammatory muscle disease of unknown cause
in which cellular immunity is thought to play an important pathogenic role. Class
II major histocompatibility complex (class II MHC: human leukocyte antigen (HLA)
DR operates as a cofactor of antigen presentation in immunological responses.
There has been a major debate over whether muscle fibers themselves synthesize
and express HLA-DR molecules and play a role in antigen presentation in PM
pathogenesis. In this study, we demonstrated that most muscle fibers from
patients with PM synthesized and expressed HLA-DR molecules on their surface.
Human leukocyte antigen-DR expression was highly specific to PM. In addition,
class II transactivator (CIITA), human leukocyte antigen DM (HLA-DM), and
invariant chain (Ii), which are indispensable for expression of mature HLA-DR
molecules and for antigen processing and presentation, were co-expressed. One of
the cytokines that could induce this expression is interferon-gamma (IFN-gamma),
released by activated lymphocytes. Our results indicate that in PM muscle fibers
synthesize and express HLA-DR molecules and may contribute to the inflammatory
responses together with lymphocytes.
PMID- 10679716
TI - Activation linearity and parallelism of the superficial quadriceps across the
isometric intensity spectrum.
AB - The purpose of this study was to assess neuromuscular activation of the three
superficial portions of the quadriceps femoris muscles during linearly increasing
isometric contraction intensities. Thirty healthy volunteers were assessed for
isometric electromyographic (EMG) activity of the vastus medialis (VM), vastus
lateralis (VL), and rectus femoris (RF) muscles with the knee at 60 degrees of
flexion. For 5 s, subjects performed isometric contractions equivalent to 10%,
20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% of the average of three maximal
voluntary contractions (MVC), in random order. Full-wave rectified and integrated
EMG signals over the middle 3 s of each contraction were expressed as a
percentage of the activity recorded during the three averaged MVCs. One sample t
tests and 95% confidence intervals were calculated at each relative torque level.
A two-factor analysis of variance (muscle by intensity) with repeated measures
was performed to evaluate parallel activation across the intensity levels.
Activation linearity was assessed via regression analysis for each muscle. VM
activation was shown to be significantly lower than expected at 20-70% MVC. VL
and RF activations were significantly higher than expected at 10% MVC, and RF EMG
was less than expected at 40-70% MVC. EMG of VM was shown to increase
significantly more than VL and RF from 80% to 90% MVC. Significant linear and
quadratic relations were also demonstrated for all three muscles. Parallel
activation of the superficial quadriceps muscles occurred from low to moderate
intensities, whereas convergence was noted at near maximal intensities.
PMID- 10679717
TI - Multiple measures of axonal excitability: a new approach in clinical testing.
AB - From measurements of nerve excitability and the changes in excitability produced
by nerve impulses and conditioning currents, it is possible to infer information
about the membrane potential and biophysical properties of peripheral axons. Such
information cannot be obtained from conventional nerve conduction studies. This
article describes a new method that enables several such measurements to be made
on a motor nerve quickly and reproducibly, with minimal operator intervention.
The protocol measures stimulus-response behavior using two stimulus durations
(from which the distribution of strength-duration time constants can be
estimated), threshold electrotonus to 100-ms polarizing currents, a current
threshold relationship (indicating inward and outward rectification), and the
recovery of excitability following supramaximal activation. The method was tested
on 30 healthy volunteers, stimulating the median nerve at the wrist and recording
from the abductor pollicis brevis. The results were comparable with previously
published normal data, but the recordings took less than 10 min. The convenience
and brevity of the new method make it appropriate for routine clinical use.
PMID- 10679718
TI - Electrophysiological evidence for afferent nerve fibers in human ventral roots.
AB - This study was designed to test the hypothesis that ventral roots in humans
contain afferent nerve fibers. We made direct electrophysiological recordings of
compound nerve action potentials in dorsal and ventral roots in children
undergoing selective dorsal rhizotomy for spastic cerebral palsy. We stimulated
the saphenous or sural nerves, which are pure sensory nerves, with electrical
stimuli while systematically recording from ventral and dorsal roots from L3 to
S2. In addition to the dorsal root nerve action potentials which we expected, we
found smaller compound nerve action potentials, which were clearly afferent, in
the ventral roots. This confirms the limited amount of experimental evidence that
ventral roots do contain some afferent nerve fibers. The functional significance
of these observations is not yet clear.
PMID- 10679719
TI - Contractile properties of the tongue's genioglossus muscle and motor units in the
rat.
AB - The contractile characteristics of individual mammalian tongue muscles have
rarely been investigated, in contrast to spinal cord-innervated and extraocular
muscles. Therefore, whole muscle and motor unit contractile forces, plus muscle
fiber types, were studied in the genioglossus, the major protrusor muscle, of the
rat tongue. The muscle, exclusively composed of fast-contracting units, could be
activated from rostroventral hypoglossal nucleus sites only. The following
figures represent the means of the contractile measures. Whole muscle twitch
tension was 7.02 g, contraction time was 14.22 ms, fusion frequency was 104 Hz,
maximum tetanic tension was 37.22 g, and fatigue index was 0.72. Single motor
unit twitch tension was 45. 9 mg, contraction time was 11.7 ms, fusion frequency
was 94.8 Hz, maximum tetanic tension was 241.95 mg, and fatigue index was 0.68.
The genioglossus muscle appeared qualitatively similar to the rat styloglossus
muscle, one of the two major retractor muscles of the tongue. The delineation of
motor unit contractile characteristics in tongue muscle is important in our
understanding of the control of tongue movement.
PMID- 10679720
TI - Proximal median neuropathy secondary to humeral neck fracture.
AB - Median neuropathies proximal to the wrist are uncommon and usually result from
penetrating injuries, fracture dislocation of the distal humerus, or compression
by fibrous bands. A 66-year-old man suffered a comminuted fracture of the
proximal humerus after a fall. Electrodiagnostic studies revealed a severe
proximal median neuropathy and a mild distal radial mononeuropathy. Proximal
median neuropathy rarely occurs in humeral neck fracture, mostly because the
median nerve is not in close contact with the humerus proximally.
PMID- 10679721
TI - Serum type IV collagen increases with duration of amyotrophic lateral sclerosis.
AB - We analyzed the serum levels of type IV collagen, a major component of the
basement membrane, during various stages of sporadic amyotrophic lateral
sclerosis (ALS). Serum concentrations of type IV collagen increased significantly
with the duration of illness. Findings indicate that the metabolism of type IV
collagen and the basement membrane may be affected in the disease process of ALS.
PMID- 10679722
TI - Chronic inflammatory demyelinating polyneuropathy after treatment with interferon
alpha.
AB - Treatment with interferon-alpha (IFN-alpha) has been associated with the
occurrence of a number of autoimmune disorders. We report a case of chronic
inflammatory demyelinating polyneuropathy (CIDP) occurring in a patient with a
chronic viral hepatitis C infection who received a novel, long-acting form of IFN
alpha. After withdrawal of the interferon treatment, this patient responded to a
single extended course of plasma exchange that resulted in a complete clinical
remission of symptoms without relapse.
PMID- 10679723
TI - Kaposi's sarcoma herpesvirus-associated Castleman's disease with POEMS syndrome.
AB - The pathogenic link between POEMS (polyneuropathy, organomegaly, endocrinopathy,
M protein, skin changes, and various other clinical signs) syndrome and
Castleman's disease is unclear. Roles for M protein in POEMS syndrome and
cytokines in systemic manifestations of multicentric Castleman's disease have
been suggested. Recently, pathogenic roles of cytokines in POEMS syndrome and
Kaposi's sarcoma-associated herpesvirus (KSHV) in Castleman's disease have been
reported. We report on a patient with KSHV-associated Castleman's disease with
POEMS syndrome, and suggest a possible role of KSHV in initiating and linking
these two diseases.
PMID- 10679724
TI - Simultaneous exacerbation and remission of central and peripheral demyelination.
PMID- 10679725
TI - AAEM news and comments.
PMID- 10679726
TI - Noninvasive determination of genome size and ploidy level in fishes by flow
cytometry: detection of triploid Poecilia formosa.
AB - BACKGROUND: In order to understand the evolutionary significance of single
triploids among the mostly diploid Poecilia formosa we have developed a simple,
noninvasive technique for DNA content and ploidy determination. METHODS: From
dorsal fin clips of 14 different fish species single cell suspensions were
obtained by chopping the material in 2.1% citric acid/0.5% Tween20, passing it
through a 0. 6-gauge needle and incubating it for 20 min at room temperature (RT)
with gentle agitation. After overnight fixation in 70% ethanol, the cells were
treated with 1ml 0.5% pepsin/0.1 M HCl for 15 min at RT before adding DAPI to a
final volume of 2 ml. The cells were stained for 1-3 h and then analyzed by flow
cytometry. RESULTS: We obtained good measurements with CVs ranging from 1.23% to
3.36%. The poeciliid species measured contain from 1.6 to 2.0 pg/nucleus, Oryzias
latipes (Medaka) exhibits a nuclear DNA content of 2.2 pg, Danio rerio
(zebrafish) 4.6 pg, Tetraodon fluviatilis (freshwater fugu) 0.70 pg. All values
except zebrafish are in good agreement with the literature. CONCLUSIONS: The
identification of living specimens of different ploidy for breeding experiments,
behavioral studies and tissue transplantations is now made possible. With slight
modifications the method can be extended to a field technique, providing
therefore a useful tool for a variety of researchers.
PMID- 10679727
TI - Four-color multiparameter DNA flow cytometric method to study phenotypic
intratumor heterogeneity in cervical cancer.
AB - BACKGROUND: Multiparameter DNA flow cytometry using a one-laser bench-top flow
cytometer has been restricted to three different colors. The two laser
FACSCalibur has recently been introduced, allowing four-color analysis.
Therefore, we optimized and extended our three-color method (Corver et al., 1994,
Corver et al. 1996) to a four-color analysis of phenotypic intra-tumor
heterogeneity using a bench-top flow cytometer. METHODS: First, the effect of a
range of different propidium iodide (PI) and TO-PRO-3 iodide (TP3) concentrations
on the coefficient of variation (CV) of the DNA histograms was measured using
paraformaldehyde-fixed lysolecithin-permeabilized peripheral blood lymphocytes
(PBLs) and SiHa and HeLa cervical cancer cells. Second, labeling freshly isolated
cervical cancers from solid tumors was optimized with a mixture of anti-keratin
antibodies. Third, the FACSCalibur hardware was modified, thereby allowing the
simultaneous measurement of allophycocyanin (APC) fluorescence (FL4) in
combination with FL3 pulse processing (FL3-W vs. FL3-A). The optimized procedure
was then applied to cell suspensions from four different human cervical cancers
to study phenotypic intratumor heterogeneity. Cell suspensions were
simultaneously stained for DNA (PI, fluorescence) and three cellular antigens:
(a) the epithelial cell-adhesion molecule (Ep-CAM; APC fluorescence), (b) keratin
(R-phycoerythrin [RPE] fluorescence) to identify the epithelial fraction, and (c)
vimentin (fluorescein-isothiocyanate [FITC] fluorescence) to label stromal cells.
RESULTS: Overall, PI produced better CVs than did TP3. The optimal concentration
of PI was 50-100 microM for all cells tested. Average CVs were 1.76% (PBL), 3.16%
(HeLa), and 2.50% (SiHa). Optimal TP3 concentrations were 0.25-2.0 microM.
Average CVs were 2. 58% (PBL), 5.16% (HeLa), and 3.96% (SiHa). Inter- or intra
DNA stem line heterogeneity of Ep-CAM expression was observed in the keratin
positive fractions. Vimentin-positive, keratin-negative cells were restricted to
the DNA diploid fraction. CONCLUSIONS: PI is a superior DNA stain to TP3 when
using intact normal PBL and human cancer cells. Four-color high-resolution
multiparameter DNA flow cytometry allows the identification of intratumor
subpopulations using PI as DNA stain and FITC, RPE, and APC as reporter
molecules. The FACSCalibur bench-top flow cytometer can be used for this purpose,
allowing the application of this technique in clinical laboratories.
PMID- 10679728
TI - Detection of cell cycle subcompartments by flow cytometric estimation of DNA-RNA
content in combination with dual-color immunofluorescence.
AB - BACKGROUND: Correlated flow cytometric measurements of phenotype and DNA-RNA
content offer detailed information on cell cycle status of subpopulations in
heterogeneous cell preparations in response to stimulation. We have developed a
method for flow cytometric analysis of DNA-RNA content that has been optimized
for simultaneous measurement of dual-color immunofluorescence. METHODS: Nucleic
acid staining was performed at low pH in the presence of saponin. DNA was stained
with 7-aminoactinomycin D (7-AAD) and RNA with pyronin Y(G) (PY); both dyes were
used at low concentrations, and 7-AAD was exchanged with nonfluorescent
actinomycin D after DNA staining to minimize fluorochrome-fluorochrome
interactions. For cell surface antigen staining, allophycocyanin was combined
with pH-independent Alexa488 instead of fluorescein-isothiocyanate (FITC) because
FITC is pH sensitive. RESULTS: This method identified cell cycle subcompartments
in CEM cells comparable to published results on cell lines using other dyes and
staining methods. Measurement of DNA-RNA content in CD8 lymphocyte subsets of
human peripheral blood mononuclear cells costimulated with CD3/CD28.2 showed
that, after 48 h of stimulation, 80% of CD8(+) T cells were in the proliferative
state, whereas 86% of CD8(+) non-T cells remained in G(0). CONCLUSIONS: This
technique permits the clear identification of cellular subpopulations by
phenotype and assessment of their cell cycle status.
PMID- 10679729
TI - Different expression profiles of human cyclin B1 in normal PHA-stimulated T
lymphocytes and leukemic T cells.
AB - BACKGROUND: In a previous work, we demonstrated with flow cytometry (FCM) methods
that accumulation of human cyclin B1 in leukemic cell lines begins during the
G(1) phase of the cell cycle (Viallard et al. , Exp Cell Res 247:208-219, 1999).
In the present study, FCM was used to compare the localization and the kinetic
patterns of cyclin B1 expression in Jurkat leukemia cell line and
phytohemagglutinin (PHA)-stimulated normal T lymphocytes. METHODS: Cell
synchronization was performed in G(1) with sodium n-butyrate, at the G(1)/S
transition with thymidine and at mitosis with colchicine. Cells (leukemic cell
line Jurkat or PHA-stimulated human T-lymphocytes) were stained for DNA and
cyclin B1 and analyzed by FCM. Western blotting was used to confirm certain
results. RESULTS: Under asynchronous growing conditions and for both cell
populations, cyclin B1 expression was essentially restricted to the G(2)/M
transition, reaching its maximal level at mitosis. When the cells were
synchronized at the G(1)/S boundary by thymidine or inside the G(1) phase by
sodium n-butyrate, Jurkat cells accumulated cyclin B1 in both situations, whereas
T lymphocytes expressed cyclin B1 only during the thymidine block. The cyclin B1
fluorescence kinetics of PHA-stimulated T lymphocytes was strictly similar when
considering T lymphocytes blocked at the G(1)/S phase transition by thymidine and
in exponentially growing conditions. These FCM results were confirmed by Western
blotting. The detection of cyclin B1 by Western blot in cells sorted in the G(1)
phase of the cell cycle showed that cyclin B1 was present in the G(1) phase in
leukemic T cells but not in normal T lymphocytes. Cyclin B1 degradation was
effective at mitosis, thus ruling out a defective cyclin B1 proteolysis.
CONCLUSIONS: We found that the leukemic T cells behaved quite differently from
the untransformed T lymphocytes. Our data support the notion that human cyclin B1
is present in the G(1) phase of the cell cycle in leukemic T cells but not in
normal T lymphocytes. Therefore, the restriction point from which cyclin B1 can
be detected is different in the two models studied. We hypothesize that after
passage through a restriction point differing in T lymphocytes and in leukemic
cells, the rate of cyclin B1 synthesis becomes constant in the S and G(2)/M
phases and independent from the DNA replication cycle.
PMID- 10679730
TI - Enrichment for submitotic cell populations using flow cytometry.
AB - BACKGROUND: One of the most dramatic events during the course of the mammalian
cell cycle is mitosis, when chromosomes condense and segregate, the nuclear
envelope breaks down, and the cell divides into two daughter cells. Although
cells undergoing mitosis are cytologically distinguishable from nonmitotic cells,
few molecular markers are available to specifically identify mitotic cells,
especially cells within different stages of mitosis. METHODS: We applied the flow
cytometric method of Juan et al. (Cytometry 32:71-77, 1998) to obtain cells with
various levels of the molecular markers cyclin B1 and phosphorylated histone H3;
fluorescence microscopy was then used to identify sorted cells in different
stages of mitosis. RESULTS: We observed the substantial enrichment of submitotic
cell populations. CONCLUSIONS: This method represents an effective approach to
obtain an enriched population of submitotic cells without the use of drug
treatments or prior synchronization.
PMID- 10679731
TI - Multiplexed single nucleotide polymorphism genotyping by oligonucleotide ligation
and flow cytometry.
AB - BACKGROUND: We have developed a rapid, high throughput method for single
nucleotide polymorphism (SNP) genotyping that employs an oligonucleotide ligation
assay (OLA) and flow cytometric analysis of fluorescent microspheres. METHODS: A
fluoresceinated oligonucleotide reporter sequence is added to a "capture" probe
by OLA. Capture probes are designed to hybridize both to genomic "targets"
amplified by polymerase chain reaction and to a separate complementary DNA
sequence that has been coupled to a microsphere. These sequences on the capture
probes are called "ZipCodes". The OLA-modified capture probes are hybridized to
ZipCode complement-coupled microspheres. The use of microspheres with different
ratios of red and orange fluorescence makes a multiplexed format possible where
many SNPs may be analyzed in a single tube. Flow cytometric analysis of the
microspheres simultaneously identifies both the microsphere type and the
fluorescent green signal associated with the SNP genotype. RESULTS: Application
of this methodology is demonstrated by the multiplexed genotyping of seven CEPH
DNA samples for nine SNP markers located near the ApoE locus on chromosome 19.
The microsphere-based SNP analysis agreed with genotyping by sequencing in all
cases. CONCLUSIONS: Multiplexed SNP genotyping by OLA with flow cytometric
analysis of fluorescent microspheres is an accurate and rapid method for the
analysis of SNPs.
PMID- 10679732
TI - Apoptosis can be detected in attached colonic adenocarcinoma HT29 cells using
annexin V binding, but not by TUNEL assay or sub-G0 DNA content.
AB - BACKGROUND: Induction of apoptosis in adherent cell lines is associated with cell
loss from the substratum. In this study the adenocarcinoma cell line, HT29,
treated with indomethacin (400microM) has been employed as a model system to
demonstrate how flow cytometric analysis can be used to quantify the changes that
occur during this process. METHODS: Adherent and floating cell populations have
been analyzed independently for effects on cell number, cell cycle
characteristics and apoptosis using TUNEL assay and Annexin V binding. In
addition apoptosis has been assessed using DNA laddering and morphology. RESULTS:
Apoptosis was detected in adherent cells treated with indomethacin using Annexin
V binding but not by other techniques employed in this study. In contrast,
analysis of "floating" cells revealed the presence of apoptotic cells both in
control and indomethacin treated cells using all the techniques employed. However
quantification by flow cytometry showed that a significantly higher proportion of
control "floaters" were late apoptotic/necrotic rather than apoptotic.
DISCUSSION: The data here illustrate the need to interpret measures of apoptosis
in adherent cell lines with care and the value of using flow cytometric
techniques in the quantitative evaluation of the process.
PMID- 10679733
TI - Simultaneous analysis of radio-induced membrane alteration and cell viability by
flow cytometry.
AB - BACKGROUND: Modifications of intracellular transfer, resulting from a loss of
membrane integrity may contribute toward setting the cell onto the pathway of
apoptosis. METHODS: We have developed an original technique of measuring
simultaneously, with flow cytometry, changes in membrane fluidity and cell death
status. Our aim was to assess the extent to which radio-induced cell death and
membrane alterations are linked. Investigations were performed on lymphocytes 24
h after whole human blood gamma-irradiation. RESULTS: Our results confirmed the
expected increase in the percentage of apoptotic cells as a function of dose, but
revealed that the percentage of necrotic cells appeared stable after irradiation.
At the same time, the fluorescence anisotropy of the living lymphocyte
subpopulation decreased significantly and dose dependently as measured 24 h post
irradiation. With TMA-DPH, the anisotropy index of apoptotic lymphocytes was
always lower than that of the viable lymphocyte subpopulation. On the other hand,
1,6-diphenyl-1,3,5-hexatriene (DPH) anisotropy was similar in apoptotic and
viable cells after irradiation. These findings suggest that apoptotic lymphocytes
are characterised by a membrane fluidization that mainly occurs on the cell
membrane surface. CONCLUSION: Our study made technical advances in using
cytometric fluorescence anisotropy measurement as an early biological indicator
of apoptosis after cellular exposure to ionising radiation.
PMID- 10679734
TI - Flow cytometry analysis of atherosclerotic plaque cells from human carotids: a
validation study.
AB - BACKGROUND: Atherosclerotic plaques are heterogeneous vascular lesions. Changes
in cell plaque composition are fundamental events inside the plaque
microenvironment that are strictly related to the clinical outcome of these
lesions (organ damage). The knowledge of these modifications may help to better
understand the pathophysiological mechanisms of atherosclerosis. METHODS: We
report on a flow cytometry method to characterize and quantify the cell
subpopulations in human atherosclerotic plaques. Cells were obtained from
endarterectomy specimens after collagenase digestion. Both surface and
intracytoplasmic antigens were labeled. RESULTS: Our data demonstrated that the
method we described allowed the characterization of cell populations that compose
the atherosclerotic plaque, avoiding contamination by tunica media smooth muscle
cells and the noise of cellular debris. Moreover this validation study showed
that about 50% of cells in the atherosclerotic plaques are inflammatory
mononuclear cells (T lymphocytes and monocytes/macrophages). CONCLUSIONS:
Reproducible quantitative methods for cell population characterization may
increase the understanding of pathophysiological mechanisms responsible for
plaque progression. The methodology herein described gave us the possibility of
quickly calculating the relative amount of each cell population and studying both
surface and intracellular markers to analyze the functional stage of the cells.
The clinical correlation was not assessed in the present study, because we used a
small patient group to validate the method, but should be the subject of further
analyses in a larger patient population.
PMID- 10679735
TI - Determination of liposome size distribution by flow cytometry.
AB - BACKGROUND: An essential parameter that describes the quality of liposome
suspensions is the mean size, respectively the size distribution. Currently
several analytical methods including laser light scattering techniques (LLST) are
being employed. METHODS: Here we present an alternative technique using flow
cytometry (FCM) to characterize uni- and polydisperse suspensions. As model
liposomes preparations containing dipalmitoylphosphatidylcholine (DPPC) were
used. A constant number of particles (1,500/s) in the fluid stream and a
representative number of 10,000 particles of each sample was measured.
Fluorescence-labeled latex beads were measured identically, and their side
scatter signals were calibrated and correlated to the results obtained with
liposome vesicles. RESULTS: Evaluation of the measurement and validation of the
FCM results in comparison to LLST confirm the reliability of results obtained
with our method. Latex beads in the range of 100-1000 nm were used for
calibration to classify liposomes. Although measurement characteristics and
calculation in both methods are basically different, very good agreement of the
results was achieved. CONCLUSIONS: Demonstration of stability, reproducibility,
and reliability of results make the employment of this method acceptable for an
adequate routine analysis technique.
PMID- 10679736
TI - Analyses of quality assessment studies using CD45 for gating lymphocytes for
CD3(+)4(+)%.
AB - BACKGROUND: The purpose of this study was to assess whether laboratories which do
not use CD45 for gating lymphocytes with three- (or four-) color flow cytometry
(non-CD45 laboratories) for CD3(+)4(+)% and CD3(+)8(+)% do worse on quality
assessment (QA) studies than laboratories which do use CD45 (CD45 laboratories).
METHODS: Data came from blood specimens donated by 62 donors (50 HIV-positive)
assayed over 2 years (November, 1996-October, 1998) by 35 laboratories in the
NIAID DAIDS Flow Cytometry QA Program. RESULTS: Non-CD45 laboratories were
significantly more likely to be classified as having unacceptable inter
laboratory results (far from the group median) than CD45 laboratories (5.6% vs
1.5%, P = 0.005 for CD3(+)4(+)%; 10.4% vs 5.0%, P = 0.007 for CD3(+)8(+)%). The
intra-laboratory range of results on blinded replicates was significantly more
likely to be deemed unacceptable (range >4%) in non-CD45 laboratories than in
CD45 laboratories for CD3(+)8(+)% (14. 5% vs 3.5%, P = 0.002) but not for
CD3(+)4(+)% (2.6% vs 1.5%, P = 0. 62). These differences in favor of CD45 gating
were observed even though the non-CD45 laboratories had been doing three-color
flow cytometry in the QA program significantly longer (P = 0.05) than the CD45
laboratories, and so would be expected to have fewer problems with the assay.
CONCLUSIONS: Laboratories which choose to use a single CD3/CD4/CD8 tube for
immunophenotyping may be sacrificing both accuracy and reproducibility.
PMID- 10679737
TI - Role of immunological lymphocyte subset typing as a screening method for lymphoid
malignancies in daily routine practice.
AB - BACKGROUND: The major diagnostic role of peripheral lymphocyte subset typing is
to distinguish between malignant and reactive conditions. METHODS: The present
study evaluates the screening efficacy of flow cytometric lymphocyte subset
typing for the presence of a lymphoid malignancy. Four hundred samples were
analyzed with a combination of anti-T-, B-, and natural killer (NK)-cell
monoclonal antibodies. RESULTS: Two hundred and twenty (55%) samples showed a
normal distribution of lymphocyte subsets, 73 (18%) samples exhibited unspecific
alterations of lymphocyte subsets, 19 (5%) samples exhibited a reactive phenotype
typical of Epstein-Barr virus/cytomegalovirus (EBV/CMV) infection, and 88 (22%)
samples expressed a phenotype suggestive of lymphoma. The most predictive
independent factor of a lymphoma-specific phenotype was the absolute lymphocyte
count (P = 0.0001, odds ratio 73.225). Seventy-eight percent of samples
containing >/=4 x 10(9)/l lymphocytes and 2% of samples with lymphocyte counts <4
x 10(9)/l exhibited a lymphoma-specific phenotype. The specificity of the
referring clinical comment was the second best predictor of a lymphoma-specific
typing outcome (P = 0.0001, odds ratio 19.589). The independent predictive values
of lymphocyte morphology and of relative lymphocyte counts were of borderline
significance. CONCLUSIONS: The use of flow cytometric lymphocyte subset typing as
a diagnostic screening method for lymphoma should be restricted to cases of
unexplained elevation of absolute lymphocyte counts with or without morphological
atypias and to cases with definite clinical symptoms of lymphoma.
PMID- 10679738
TI - Lymphocyte subsets and specific T-cell immune response in thalassemia.
AB - Infection is very common in thalassemia and is one of the major causes of death.
To date, it is not quite clear why these patients are susceptible to infection.
In this study, lymphocyte immunophenotyping for CD3(+) (T-cells), CD3(+)CD4(+) (T
helper/inducer cells), CD3(+)CD8(+) (T-suppressor/cytotoxic cells), CD3(-)CD19(+)
(B-cells), and CD3(-)CD16/56(+) (natural killer cells) subsets and expression of
the activation antigen CD69 on CD3(+)CD4(+) and CD3(+)CD8(+) T-cells were
determined in the whole blood of thalassemia patients, using a three-color flow
cytometric technique. Results showed that only splenectomized beta
thalassemia/hemoglobin (Hb) E patients displayed a marked increase in absolute
number of all lymphocytes. In addition, splenectomized beta-thalassemia/Hb E
showed a significantly lower percentage of CD3(+) cells, with a corresponding
increase in CD19(+) cells. These differences, when compared with normal subjects
and other thalassemia patients, may be attributed to splenectomy. alpha
thalassemia patients, on the other hand, showed no significant difference from
the normal group. While lymphocyte subsets in splenectomized beta-thalassemia/Hb
E patients showed an abnormal distribution, T-cell activation in these patients
was not different from the activation seen in normal subjects. This implies that
thalassemia patients, during the steady state of disease, appear to have normal T
lymphocyte function with only moderate abnormalities of T- and B-lymphocyte
subsets.
PMID- 10679739
TI - Improving accuracy in the grading of renal cell carcinoma by combining the
quantitative description of chromatin pattern with the quantitative determination
of cell kinetic parameters.
AB - The determination of grade and stage in renal cell carcinomas (RCCs) often fails
to predict the actual clinical outcome for individual patients. The aim of the
present work was to investigate whether it is possible to significantly improve
the prognostic accuracy of the grading system by using the combination of two
independent computer-assisted microscopy techniques. The first technique relates
to the quantitative description of morphonuclear and nuclear DNA content features
by means of the image analysis of Feulgen-stained cell nuclei, and the second
quantitatively characterizes tumor growth by means of different cell kinetic
parameters. These parameters consist of a duplication of a time-related parameter
determined by means of the technique of using silver-stained proteins in
interphase nucleolar organizer regions (AgNOR), a proliferation index determined
by means of MIB-1 immunohistochemistry, and an apoptotic index determined by
means of the terminal dUTP nick end labeling technique. The prognostic value of
these quantitative features was investigated in a series of 60 RCCs. The
quantitative analysis of Feulgen-stained nuclei made it possible to identify
subgroups of patients with significantly different prognoses in both grade II and
grade III RCCs. We labeled the RCCs associated with the most favorable prognoses
as grade II- and III- and those with the least favorable ones as grade II+ and
III+. The two most important kinetic variables to identify patients with
different clinical outcomes were the MIB-1 index and the mean AgNOR area in the
MIB-1-positive cells. Three significantly different survival curves were obtained
for the 53 grade II and III RCC patients. Our results show that conventional RCC
grading can be significantly improved by the quantitative analysis of Feulgen
stained nuclei, by cell kinetic parameter determination, and, more importantly,
by combining the proliferation index with the mean AgNOR area parameter.
PMID- 10679740
TI - Flow cytometric DNA ploidy, p53, PCNA, and c-erbB-2 protein expressions as
predictors of survival in surgically resected gastric cancer patients.
AB - In order to determine retrospectively the impact of some cytometric and
immunohistochemical parameters on the overall survival of gastric cancer patients
treated with surgery alone, paraffin-embedded tumor samples from 137 gastric
carcinoma patients undergoing curative resection from 1987-1993 were analyzed by
flow cytometry (FCM) and immunohistochemistry (p53, c-erbB-2, and PCNA
expression). FCM-derived parameters were DNA ploidy and fraction of S-phase cells
(SPF). Multiple regression analysis was applied to determine the prognostic
significance of the conventional clinicopathologic findings together with the
flow cytometric and immunohistochemical parameters on overall survival. When all
parameters were entered simultaneously into the Cox regression model, stage and
DNA ploidy (DNA index >1.35) clearly emerged as the only independent prognostic
factors. When the stages were analysed separately, the independent prognostic
factors resulted DNA ploidy in early stages (I-II) and grading in stage IIIA
tumors. For stage IIIB tumors, no independent prognostic factor was found. These
results indicate that the DNA ploidy pattern is a valuable predictor of survival
in curatively resected gastric cancer patients, especially when less advanced
tumors are taken into consideration.
PMID- 10679741
TI - Variation of flow cytometric DNA measurement in 1,485 primary breast carcinomas
according to guidelines for DNA histogram interpretation.
AB - From 1990-1996, 1,485 previously untreated invasive breast carcinomas were
sampled by a pathologist for flow cytometric DNA analysis. The aim of the present
work was to study the variations of flow cytometric DNA ploidy and S-phase
evaluation according to the conditions of DNA histogram interpretation. Results
obtained with the American Consensus guidelines of 1993 and the Francois Baclesse
Department of Pathology's own guidelines are presented. According to the
percentage of events taken into account to identify a DNA aneuploid peak, the
proportion of DNA diploid cases can change from 35-39%. For S-phase evaluation,
although the two guidelines were quite different, the results of S-phase cutoff
were identical. Whichever guidelines were used, there was a strong relationship
between DNA ploidy and/or S-phase and classical clinicopathological factors (T,
N, histological type, grade, receptor status, or lymphatic invasion), with the
exception of age, whose correlation was discrepant with S phase according to the
set of guidelines. Whichever guidelines were used, ploidy and S phase correlated
strongly with survival (overall, metastasis-free, or recurrence-free). Hence we
recommend the use of the American consensus guidelines, despite minor
imperfections, because they are now well-known, allow a high yield in the ratio
of assessable S phases, and permit standardization in the technical processing
and reporting of S phases, thanks to the use of terciles.
PMID- 10679742
TI - Novel functional multiparameter flow cytometric assay to characterize
proliferation in skin.
AB - Keratins are a group of cytoskeletal proteins that are found in human epidermis
and other stratified squamous epithelia. Several different types of keratins have
been described. Keratin 10 (K10) is a keratin that is expressed in well
differentiated, suprabasal keratinocytes, and keratin 6 (K6) is a keratin which
is associated with hyperproliferation. Psoriasis is a chronic inflammatory skin
disease, and besides inflammation, disturbed differentiation and
hyperproliferation are its hallmarks. In order to study the hyperproliferation
associated keratinization in both well differentiated and poorly differentiated
keratinocytes, and in order to assess the proliferative activity of all K10 and
K6 subpopulations, simultaneous assessment of K6, K10, and DNA content is
required. So far, a triple staining protocol had not been available. In the
present study, we established a novel protocol for simultaneous measurement of
K6, K10, and DNA content, which enables the characterization of the proliferative
activity of several cellular subpopulations in epidermis. From 16 patients with
psoriasis and from 15 healthy volunteers, punch biopsies were obtained. After
preparation of single cell suspensions, cells were stained with the anti-keratin
10 IgG(1)-isotype monoclonal antibody RKSE60, with the anti-keratin 6 IgG(2a)
isotype monoclonal antibody LHK6B, and with the DNA fluorochrome TO-PRO-3 iodide.
Isotype specific secondary antibodies conjugated with phycoerythrein (PE) and
fluorescein isothiocyanate (FITC) were used as the second step in the staining
procedure. Controls were measured omitting the primary antibodies, and gates were
set in order to differentiate between the K10 and K6 subpopulations. Samples from
both psoriatic patients and healthy volunteers were than measured. Owing to the
IgG specificity of RKSE60 and LHK6B, no cross-reactivity was observed between
these antibodies. The triple staining with RKSE60, LHK6B, and TO-PRO-3 iodide
showed subpopulations of K10 expressing cells, K10/K6 co-expressing cells, and K6
only expressing cells. There was a significant difference in the proportion of K6
expression and K10/K6 co-expression between psoriatic and normal skin. Moreover,
the proliferative activity of these subpopulations could be quantified by this
protocol. We concluded that a triple staining protocol for the assessment of K6,
K10, and DNA content, using the monoclonal antibodies LHK6B, RKSE60, and TO-PRO-3
iodide, supplies reliable and reproducible data for cellular studies on these
keratins and for studying the proliferative activity of the subpopulations of
these keratins in epidermis. Moreover, the present study showed that with respect
to the proportion of K6, significant differences are present between psoriatic
and healthy human skin.
PMID- 10679743
TI - Response of chemosensitive and chemoresistant leukemic cell lines to drug
therapy: simultaneous assessment of proliferation, apoptosis, and necrosis.
AB - BACKGROUND: The balance between cell proliferation and drug-induced cell death by
apoptosis or necrosis plays a major role in determining response to chemotherapy.
Commonly-used DNA analysis methods cannot study both parameters simultaneously. A
new approach described here combines a green fluorescent membrane-intercalating
dye (PKH67) with Hoechst 33342 or annexin V and propidium iodide, to allow
simultaneous assessment of cell division, cell cycle status, apoptosis, and
necrosis, respectively. METHODS: To test this approach, we used cultured K562
leukemic cell lines which are drug-sensitive (K562S) or drug-resistant (K562R) by
virtue of whether they lack or exhibit expression, respectively, of the gp-170
(PGP) glycoprotein pump involved in multidrug resistance. RESULTS: We found that:
1) PKH67 fluorescence intensity decreases proportionately to number of cell
divisions, 2) labeling with PKH67 does not alter either cell cycle distribution,
as assessed by vital DNA staining with Hoechst 33342, or cell growth, and 3)
using a simple threshold analysis method suitable for real-time sorting
decisions, subpopulations of proliferating cells present at initial levels of >/=
10% can readily be detected after two cell division times, based on decreased
PKH67 intensity. Finally, we demonstrated that after treatment of an admixture of
K562S and K562R with vincristine, triple-labeling with PKH67, annexin V, and
propidium iodide can be used to identify and sort those cells which remain not
only viable (nonnecrotic, nonapoptotic) but actively dividing (decreased PKH67
intensity) in the presence of drug. CONCLUSIONS: Although the studies described
here were carried out in a model system using cells having known drug resistance
phenotypes, we expect that the methods described will be useful in ex vivo
studies of clinical leukemic specimens designed to identify the role played by
specific chemoresistance proteins and mechanisms in therapeutic outcomes for
individual patients.
PMID- 10679744
TI - Bcl-2: bax and bcl-2: Bcl-x ratios by image cytometric quantitation of
immunohistochemical expression in ovarian carcinoma: correlation with prognosis.
AB - Bcl-2 is a proto-oncogene which is involved in prolonging cell survival by
inhibiting programmed cell death. Bax and bcl-x are members of the bcl-2 family;
when overexpressed, they can counteract the ability of bcl-2 to inhibit
apoptosis. This suggests a model in which the ratios of bcl-2 to bax and bcl-x
can be used to determine response to therapy and prognosis. The expression of bcl
2, bax and bcl-x was studied in 50 ovarian carcinomas. The percentage of positive
area immunostained (PPA) in the nucleus and cytoplasm of each ovarian carcinoma
was quantitated in 15 high power fields by image cytometry. The ratios were
obtained by dividing the PPA of bcl-2 by the PPA of bax and bcl-x. 17 of 50
ovarian carcinomas (34%) stained positively for bcl-2, 39 for bax (78%) and 47
for bcl-x (94%). Although there is no significant statistical correlation between
expression of bcl-2, bax or bcl-x and grade (P = 0.15; P = 0. 47; P = 0.56),
stage (P = 0.71; P = 0.6; P = 0.42), and overall or disease-free survival (P =
0.26; P = 0.55; P = 0.16), increased bcl-2 expression was demonstrated in
patients with shortened overall and disease-free survival. Also, increased
expression of bax and bcl-x was associated with increased overall and disease
free survival. Bcl-2:bax and bcl-2:bcl-x ratios less than 1 are associated with
survival advantage, although not statistically significant (P = 0.83; P = 0.93).
Image cytometric measurement of bcl-2, bax, and bcl-x expression is feasible.
There is a tendency for their expression to correlate with prognosis in ovarian
carcinomas.
PMID- 10679745
TI - Detection of apoptotic T lymphocytes in peripheral blood of human
immunodeficiency virus (HIV)-infected subjects by apostain.
AB - Apoptosis has been indicated as a mechanism of T cell depletion in HIV-infected
subjects and useful in monitoring disease progression. We investigated for the
presence of apoptotic T lymphocytes in 130 HIV subjects in various stages of
disease by the newly developed cell permeant DNA dye Apostain. Blood was
collected in EDTA, lysed in buffered ammonium chloride, fixed in freshly prepared
1% paraformaldehyde and stored in aliquots at -80 degrees C. Samples were thawed
and double stained with FITC conjugated-CD3 monoclonal antibody and Apostain.
Flow cytometry was then performed and T cells gated on a CD3 versus side scatter
dot plot. Normal samples treated in the same manner served to establish the
boundary separating non-apoptotic from apoptotic cells. There was no
statistically significant association between the proportion of subjects with
detectable apoptotic cells and CDC clinical categories A, B and C at the time of
admission to the study, although a trend toward a lower apoptotic rate in
category A (A= 29%, B=40% and C=41%) was noticed. Conversely, CDC T cell
categories 2 and 3 contained significantly higher proportions of Apostain
positive patients (1=6%, 2=32% and 3=49%, P=0.072, by chi(2) test). Most
importantly, Apostain test identified subjects at risk of disease progression
during a 3.5-7 months follow-up in CDC category B and 2 (P=0.008 and P=0.0003, by
Fisher's exact test, respectively). A similar, albeit not statistically
significant trend was observed also in the other categories. Not requiring
extensive manipulation of fresh samples nor cumbersome culture techniques,
Apostain test appears suitable for identifying HIV subjects at higher risk of
disease progression in clinical settings.
PMID- 10679746
TI - Comparison of DiOC(6)(3) uptake and annexin V labeling for quantification of
apoptosis in leukemia cells and non-malignant T lymphocytes from children.
AB - Early during apoptosis, there is a reduction in mitochondrial transmembrane
potential (MTP) and externalization of phosphatidylserine (PS) in cell membrane
prior to eventual cell death. Flow cytometric detection techniques targeting
these changes, reduction of DiOC(6)(3) uptake upon the collapse of MTP and
annexin V binding to PS have been successfully used to detect apoptotic cells.
These methods have given comparable results when cell lines were used. We
compared the two different techniques, DiOC(6)(3) uptake and Annexin V-propidium
iodide co-labeling in the quantification of cytarabine, vincristine and
daunorubicin induced apoptosis on three leukemia cell lines (HL-60, CEM, U937),
and bone marrow blasts from 26 children with acute myeloid leukemia, 14 with T
cell acute lymphoblastic leukemia. Anti-Fas-induced apoptosis in culture-grown
peripheral blood T lymphocytes on 18 samples from 9 children with non-malignant
conditions were also studied by these techniques. Our results showed that there
is a correlation (P < 0. 05) between the apoptosis rates measured by these two
techniques for drug-induced apoptosis in myeloid and lymphoid blasts, and for
anti-Fas mAb-induced apoptosis in T lymphocytes. This data suggests that
reduction of the MTP and PS externalization may be common to many apoptotic
pathways and techniques targeting either of these changes may be used in
quantification of apoptosis in different clinical samples.
PMID- 10679748
TI - Forum: journal club
PMID- 10679747
TI - CD4 count/viral load in HIV.
PMID- 10679749
TI - RAPD library fingerprinting of bacterial and human DNA: applications in mutation
detection.
AB - Random amplified polymorphic DNA (RAPD) fingerprinting is a modification of the
polymerase chain reaction (PCR), which utilises a single, arbitrarily-chosen
primer to amplify a number of fragments from a given template DNA to generate a
discrete "fingerprint" when resolved by gel electrophoresis. Alterations by as
little as a single base in the primer sequence lead to marked alterations in the
fingerprints generated with a given template under optimised conditions. By
inference, single base alterations in the genomic template DNA may also lead to
changes in the RAPD fingerprints. We have examined this potential application to
detect mutations in bacteria and cultured human cells. We have utilised
Escherichia coli and human lymphoblastoid cell lines exposed to UV radiation,
selected for by cellular mutation assays, and compared RAPD fingerprints of
mutant and non-mutant samples. Polymorphisms became evident as the presence
and/or absence of DNA fragments between the two samples. A dose-dependent
increase in the number of polymorphic bands was seen with UV irradiation of E.
coli. To a lesser degree, polymorphisms were also evident for human
lymphoblastoid DNA. The possible underlying mechanisms for these alterations in
fingerprints as a result of mutation(s) in the primer binding site(s) are
discussed. The ability of RAPD fingerprinting to detect a mutant in a population
of non-mutants is evaluated, and whilst the lack of sensitivity inherent in the
technique precludes its use as a mutation screening assay, its potential for
generation of mutant and non-mutant DNA probes for other mutation detection
techniques may prove to be of great merit. Teratogenesis Carcinog. Mutagen. 20:49
63, 2000.
PMID- 10679750
TI - Evaluation of the genotoxic effects of pyrimethamine, an antimalarial drug, in
the in vivo mouse.
AB - Pyrimethamine is an antimalarial drug and a known teratogenic agent. With this
drug, positive and negative results have been reported by various investigators
in in vivo and in vitro genotoxicity/mutagenicity assays. In this investigation
the genotoxic effects of pyrimethamine (PY) were tested in mice in vivo systems,
using the bone marrow micronucleus test (MNT) and the transplacental MN test
(TMNT). PY at the highest dose (40 mg/kg) induced statistically significant MN in
bone marrow cells at 24 and 48 h. In the transplacental MN test, PY did not
induce significant MN in fetal liver or in maternal bone marrow. Teratogenesis
Carcinog. Mutagen. 20:65-71, 2000.
PMID- 10679751
TI - Pathogenesis of cleft palate in mouse embryos exposed to 2,3,7, 8
tetrachlorodibenzo-p-dioxin (TCDD).
AB - 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces cleft palate in mouse embryos.
It has been believed that TCDD inhibits palatal fusion by suppression of
disappearance of medial edge epithelial (MEE) cells on palatal shelves. However,
we found that exencephalic mouse embryos were resistant to the cleft palate
inducing action of TCDD. In the present study, we examined cell kinetics in MEE
and palatal mesenchyme in embryos exposed to TCDD with or without exencephaly for
elucidation of pathogenesis of cleft palate by TCDD. Pregnant Jcl:ICR mice were
given TCDD orally at 40 microg/kg at gestation day (GD) 12.5. Embryos were
harvested between GD 13.5 and GD 14.5 and examined for cell kinetics by
bromodeoxyuridine (BrdU) and TUNEL methods. Exencephaly was induced by
intraperitoneal injection of CdCl(2) at 6 mg/kg at GD 7.5. BrdU-positive cells
were decreased in TCDD-treated embryos in MEE and mesenchymal cells. TUNEL
positive cells were detected in MEE both in TCDD-treated and untreated control
embryos, as well as in embryos with or without exencephaly. We also measured the
gap between shelves between GD 14. 0 and GD 14.5. There were no differences at GD
14.0 between control and TCDD-exposed embryos, but at GD 14.25 and GD 14.5, TCDD
exposed embryos had wider gaps than controls. These findings indicate that cleft
palate by TCDD results from poor development of palatal shelves. Teratogenesis
Carcinog. Mutagen. 20:73-86, 2000.
PMID- 10679752
TI - Assessing the predictive validity of frog embryo teratogenesis assay-Xenopus
(FETAX).
AB - The ability of frog embryo teratogenesis assay - Xenopus (FETAX) to identify the
potential developmental toxicity of a group of diverse chemicals was evaluated by
comparison with results from in vivo studies in rats. A total of 12 chemicals,
three of which were shown to be teratogenic in vivo, four of which were
embryolethal (but not teratogenic) in vivo, and five which did not produce any
developmental toxicity in vivo in the rat were evaluated using FETAX. Results of
the FETAX test with these 12 blind-coded compounds correctly predicted that three
chemicals had strong teratogenic potential, four had low teratogenic hazard
potential but were embryolethal, and five posed little if any developmental
toxicity hazard. In addition, this study concluded that within a family of
chemistry analogs could be ranked according to relative teratogenic hazard and
that for the teratogenic compounds the types of malformations induced in Xenopus
mimicked the abnormalities induced in vivo in rats. In summary, these results
confirmed that the FETAX assay is predictive and can be useful in an integrated
biological hazard assessment for the preliminary screening of chemicals.
Teratogenesis Carcinog. Mutagen. 20:87-98, 2000.
PMID- 10679753
TI - Analysis of recent trends in prostate cancer incidence and mortality.
AB - BACKGROUND: There is debate over whether the recent increases seen in prostate
cancer are due to lead-time bias from screening, or identification of clinically
insignificant lesions. METHODS: Population-based incidence rates for 1973-1996
were calculated, based on the Surveillance, Epidemiology, and End Results Program
(SEER) tumor registries. Relative incidence rates for prostate cancer by stage,
fatal incidence, and lymph nodes were calculated, adjusted for age. RESULTS:
Localized and regional stage prostate cancer increased through 1992 and then
dropped. The rate of distant-stage disease was relatively stable from 1973-1991,
with a decrease in distant stage starting in 1992. The 2-year mortality rates
were constant for 1973-1989. A decline in the 2-year mortality among cases (fatal
incidence) also began in 1992. CONCLUSIONS: These data show large increases in
early disease, followed by a drop and leveling off along with a decrease in
advanced disease (distant stage, 2-year mortality, positive lymph nodes). This
indicates that the increasing incidence rates for prostate cancer are largely due
to lead-time bias from increased early detection and treatment of prostate
cancer. However, since incidence rates have not declined to rates seen in the
1970s, the additional cases may also reflect length bias from insignificant
lesions or a true increase in incidence over time.
PMID- 10679754
TI - Effects of tobacco smoke on tumor growth and radiation response of dunning R3327
prostate adenocarcinoma in rats.
AB - BACKGROUND: The influence of tobacco smoke has been investigated on the growth
rate and histology of prostate cancer, both in untreated tumors and in those
subjected to fractionated irradiation. METHODS: Twenty-five rats were implanted
bilaterally with Dunning R3327 tumor fragments at 10 weeks of age. Approximately
3 months later, they were randomly allocated to two groups, one of which was
exposed to tobacco smoke for an hour each day, 5 days a week. Three weeks later
the groups were further subdivided into two groups which acted as controls or
were subjected to 5 daily doses of 6 Gy. The tumors were measured weekly to
construct growth curves. At a fixed time, 9 weeks or 20 weeks later, the animals
were sacrificed and the tumors were removed for histological evaluation of the
tissue composition. Sections from each tumor were scored in a morphometric
analysis of the fraction of the area of tumor that was occupied by (epithelial)
tumor cells, by stroma, or by luminal spaces. In addition, the density of mast
cells was assessed in adjacent sections stained with toluidine blue. RESULTS:
Smoking caused only minor changes in the growth rates of both the control and the
irradiated tumors. At the cellular level, smoking caused a small but significant
increase in the fraction of tumor cells relative to controls. Irradiation also
caused a small but significant decrease in tumor cell fraction compared to
controls, even after 20 weeks of regrowth. This difference was reduced in the
smoking and irradiation group. The main difference observed was in the mast cell
numbers. Smoking caused a 4-fold increase in mast-cell density. Irradiation
caused an even greater increase (25-fold). The combination of smoking and
irradiation resulted in an intermediate increase (10-fold). CONCLUSIONS: Long
term smoke exposure can slightly alter the growth rate and morphology of Dunning
R3327 rat prostatic adenocarcinoma, but our study does not show a negative effect
on the outcome of radiation treatment of this tumor model. We have also
demonstrated a highly elevated number of mast cells in the irradiated group, and
have shown that smoke exposure significantly depressed the radiation-induced
enhancement of the number of mast cells.
PMID- 10679755
TI - Heterogeneous apoptotic responses of prostate cancer cell lines identify an
association between sensitivity to staurosporine-induced apoptosis, expression of
Bcl-2 family members, and caspase activation.
AB - BACKGROUND: The goal of this work was to identify mechanisms for the inability of
metastatic prostate cancer cells to engage the apoptotic pathway following
hormonal or cytotoxic therapy. METHODS: Genotypically diverse cell lines isolated
from patients with metastatic disease were used. RESULTS: The LNCaP and TsuPr(1)
lines exhibited quintessential apoptotic features in response to the pleiotropic
apoptotic inducer staurosporine (STS): rapid cytochrome c translocation to the
cytosol, proteolytic processing and catalytic activation of caspase-3 and -7,
proteolytic inactivation of the death substrates DNA fragmentation factor (DFF)
and poly-ADP-ribose polymerase (PARP), and TUNEL-positive polyfragmented nuclei.
In contrast, DU-145 and PC-3 cells exhibited few, if any, of these features,
while appearing necrotic by confocal microscopy. The presence of caspase-3 and -7
without proteolytic processing suggested that the apoptotic blockade was upstream
of executioner caspases in these resistant cell lines. To identify the locus of
this block, Western blot analysis of cytochrome c subcellular localization and of
pro- and antiapoptotic Bcl-2 family members was performed, and suggested that
heterogeneous expression of these proteins might be the underlying mechanism for
apoptotic resistance to STS in these cell lines. Thus, the absence of the
proapoptotic Bax in DU-145 cells indicated a mechanism for apoptotic resistance
of these cells. Similarly, decreased Bax expression during STS treatment, coupled
with overexpression of the antiapoptotic Bcl-x(L) and inability to translocate
cytochrome c to the cytosol, provided a mechanism for the insensitivity of PC-3
cells. CONCLUSIONS: These observations suggest that activation of the apoptotic
machinery in metastatic prostate cancer cell lines may be determined by
expression levels of Bcl-2 family members, by the ability of cytochrome c to
translocate to the cytosol, and by the ability of the caspase pathway to react in
response to activation of the mitochondrial phase.
PMID- 10679756
TI - Regressive changes and neuroendocrine differentiation in prostate cancer after
neoadjuvant hormonal treatment.
AB - BACKGROUND: We studied the extent of neuroendocrine (NE) tumor cell
differentiation and its relation to regressive changes in prostate cancer after 3
month hormonal treatment. METHODS: Radical prostatectomy specimens from 103
patients, randomized to 3-month neoadjuvant LH-RH-analogue treatment (neoadjuvant
group) or to surgery alone (control group), were available for analysis. The
effects of hormonal treatment in terms of positive surgical margins, the degree
of histopathological changes, and tumor cell proliferation were evaluated in
relation to NE-differentiation assessed with antibodies against chromogranin A
(CGA). RESULTS: Both the number of CGA-positive cells/cm(2) (P < 0.003) and the
proportion of NE-positive tumors (P = 0.07) were greater in the neoadjuvant group
than in the control group. No correlation existed between NE-differentiation and
the effects of the neoadjuvant hormonal treatment; nor did NE-differentiation
correlate to the decrease in serum PSA. CONCLUSIONS: Neuroendocrine
differentiation in prostate cancer increases after 3 months of neoadjuvant
hormonal treatment but does not correlate to the effects of hormonal treatment.
PMID- 10679757
TI - Immunohistochemical staining for DNA topoisomerase II-alpha in benign,
premalignant, and malignant lesions of the prostate.
AB - BACKGROUND: The DNA topoisomerase II-alpha (topo II-alpha)-targeting drug
etoposide was recently shown to be an active agent in the combined chemotherapy
of hormone-insensitive prostatic carcinoma. Aside from being the molecular target
of etoposide, topo II-alpha is also a cell proliferation marker. Much
experimental data indicate that cells sensitive to topo II-targeting
chemotherapeutic drugs are rapidly proliferating and show elevated topo II
expression. There is little information concerning topo II expression in lesions
of the prostate. METHODS: Paraffin blocks from cases of invasive prostatic
carcinoma, prostatic intraepithelial neoplasia, and prostatic nodular hyperplasia
were retrieved from the surgical pathology files at the University of Utah Health
Sciences Center. Using a new immunohistochemical stain, specific for the alpha
isoform of DNA topo II, enzyme expression was evaluated in 54 prostatic
adenocarcinomas, 22 lesions of high-grade prostatic intraepithelial neoplasia
(PIN), and 10 cases of benign prostatic nodular hyperplasia. Results were
semiquantitated by determining for each case a topo II-alpha index, which
represented the percent of positively staining cells. RESULTS: The average topo
II-alpha index for well-differentiated prostatic adenocarcinomas (Gleason scores
2-4) was 1.5 +/- 0.9; for moderately differentiated tumors (Gleason scores 5-7),
3.1 +/- 2.4; and for poorly differentiated tumors (Gleason scores 8-10), 6.7 +/-
5.5. The average topo II-alpha index for all invasive prostatic adenocarcinomas
was 4.0 (range, 0-19.0). Benign prostatic nodular hyperplasia had the lowest
average topo II-alpha index, of 0.54 (range, 0.2-1.0). The average topo II-alpha
index of 2.3 (range, 0-8.6) for high-grade prostatic intraepithelial neoplasia
was intermediate between the invasive tumors and benign prostate. CONCLUSIONS:
Topo II-alpha expression in carcinoma of the prostate correlates with Gleason
score. The carcinomas with the highest expression of enzyme are more poorly
differentiated and have the highest Gleason scores. Prostatic nodular hyperplasia
shows little expression of topo II-alpha. Prostatic intraepithelial neoplasia has
an average topo II-alpha index intermediate between nodular hyperplasia and
carcinoma.
PMID- 10679758
TI - Establishment and characterization of a prostatic small-cell carcinoma cell line
(PSK-1) derived from a patient with Klinefelter syndrome.
AB - BACKGROUND: Prostatic small-cell carcinoma (SMCC) is an extremely aggressive,
rarely occurring tumor, and there has been no previous report of prostatic SMCC
in association with Klinefelter syndrome. This study reports on the first such
case and the establishment of the first cell line of SMCC from this tumor.
METHODS: Prostatic SMCC tissue was derived from a 29-year-old man with
Klinefelter syndrome. Characteristics of the culture tumor cells were evaluated
with cell growth in vitro, neuron-specific enolase (NSE) secretion ability,
tumorigenicity in nude mice, chemosensitivity to anticancer drugs, and karyotypic
analysis. RESULTS: A culture cell line (PSK-1) was successfully established from
prostatic SMCC with Klinefelter syndrome. PSK-1 cells had a polygonal epithelioid
morphology and demonstrated loss of contact inhibition. These cells secreted NSE
into the culture supernatant. Tumors produced in nude mice were histologically
similar to the original SMCC. In a chemosensitivity test, PSK-1 cells were found
to be sensitive in vitro to cisplatin, etoposide, and doxorubicin, but resistant
to dacarbazine and 5-fluorouracil. Cytogenetic analysis showed that the PSK-1
cells at passage 35 revealed 76-84 chromosomes, with a mode of 82 chromosomes.
CONCLUSIONS: PSK-1 cells could represent some properties of the original tumor
cells, and could be used in studies on the etiology and treatment of this
disease.
PMID- 10679759
TI - Presence of receptors for bombesin/gastrin-releasing peptide and mRNA for three
receptor subtypes in human prostate cancers.
AB - BACKGROUND: Bombesin-like peptides can function as autocrine or paracrine growth
factors and stimulate the growth of some cancer cells, including human prostate
cancer. Three bombesin receptor subtypes, termed gastrin-releasing peptide
receptor (GRPR), neuromedin B receptor (NMBR), and bombesin receptor subtype 3
(BRS-3), have been identified in rodents and humans. METHODS: We investigated the
presence and characteristics of the functional receptors for bombesin/GRP in
human prostate adenocarcinoma specimens by radio-receptor assay and the mRNA
expression of the three bombesin receptor subtypes by RT-PCR. RESULTS: Of the 80
specimens of primary prostate cancer examined by receptor binding assays, 50 (
approximately 63%) showed high-affinity, low-capacity binding sites for
bombesin/GRP, and 12 of these 50 receptor-positive specimens also showed a second
binding site. Of the 22 prostate cancer specimens analyzed by RT-PCR, 20 (91%)
expressed GRPR mRNA, 3 (14%) showed NMBR mRNA, and 2 ( approximately 9%) revealed
BRS-3 mRNA. No correlation was observed between receptor expression and patients'
age or pathological data. CONCLUSIONS: The detection of a wide distribution of
bombesin/GRP receptors in human prostate carcinomas supports the view that they
may be involved in modulation of tumor progression and suggests that approaches
based on binding of bombesin receptor antagonists or new targeted cytotoxic
bombesin analogs to prostate cancers could be considered for the therapy.
PMID- 10679760
TI - Rye bran and soy protein delay growth and increase apoptosis of human LNCaP
prostate adenocarcinoma in nude mice.
AB - BACKGROUND: In this study, we investigated whether dietary intervention could
inhibit tumor growth of an androgen-sensitive human prostatic cancer. METHODS:
LNCaP cells were transplanted subcutaneously in nude-mice. The animals were then
put on different diets and tumor take, tumor growth and prostate specific antigen
(PSA) secretion were studied during 9 weeks. RESULTS: Palpable tumors developed
in 75% of the tumor-cell injected sites in animals fed a control diet (corn
starch, sucrose, etc.) whereas, for animals given rye bran (RB), ethyl acetate
extraction from rye bran supplemented cellulose based diets (CCEE), palpable
tumors were seen in only 30% and for soy protein based diets (SCC) 50% of the
transplantation sites, respectively. The tumors that grew to palpable size in the
rye (RB) and soy (SCC) groups were smaller and secreted less PSA than those in
the control group. In the rye and soy groups tumor cell apoptosis was increased,
but cell proliferation was unaffected. Addition of fat to the rye diet reduced
its effect on prostate cancer growth. CONCLUSIONS: Factors in rye bran and soy
protein may inhibit prostate cancer growth. The effect is more apparent for rye
than for soy. Further studies are needed to identify the effective substances and
to explore the mechanism of action.
PMID- 10679761
TI - Follow-up ProstaScint scans verify detection of occult soft-tissue recurrence
after failure of primary prostate cancer therapy.
AB - BACKGROUND: A reliable imaging modality is required to uncover occult soft-
tissue recurrence after failure of primary prostate cancer therapy. This
retrospective study was done to evaluate the ability of the (111)Indium-labeled
monoclonal antibody (ProstaScint(R)) scan in detection of prostatic bed
recurrence and/or metastases to regional and/or distant lymph nodes. METHODS: One
hundred sequential patients were evaluated with repeated ProstaScint(R) scans
because of evidence of recurrence during the course of their disease. These 100
patients were followed closely from November 1994 and April 1999, and had
concurrent bone scans and serum prostate-specific antigen (PSA) evaluations. They
have had hormone therapy (n = 53) and/or experienced a rising PSA after radical
prostatectomy (n = 38) or after radiation therapy (n = 56). Scan images were
scored 0-3, where score 0 = negative, score 1= prostate bed uptake, score 2 =
regional lymph node uptake, and score 3 = distant lymph node uptake. In each
patient, the uptake of the follow-up scan(s) was compared to that of the initial
scan. RESULTS: The median age was 70 years (range, 45-87), and 23 patients had a
positive bone scan. The average PSA was 40.5 ng/ml (standard deviation, 223.5).
There was 257 scans representing 100 patients. All patients had at least 2 scans,
35 patients had 3 scans, and 11 patients had 4 scans. No individual exhibited
detectable adverse clinical reactions during or after the scan. The findings of
the initial and consecutive scans were anatomically consistent in 79%, whereas in
21% there were skip metastases. In 24 patients the lesions progressed by scan and
PSA, 10 patients showed progression of scan but no PSA progression, 49 patients
showed no change, and 17 patients showed a remission related to adjuvant therapy.
CONCLUSIONS: The consistency on repeating the scan (79%) and the high percentage
of patients showing persistent uptake at the prostate bed (43%) as well as the
percentage of detection of regional nodes (20%) and distant nodes (32%) reflects
the importance of using the ProstaScint(R) scan in finding occult recurrences
after primary treatment failure of prostate cancer. These results are similar to
those reported earlier in autopsy series studies in similar populations.
PMID- 10679763
TI - Preface
PMID- 10679762
TI - Serum levels of PSMA.
PMID- 10679764
TI - Stem cells and the cellular organization of the brain.
AB - The modern field of neuroscience emerged in the hands of neuroanatomists at the
end of the last century. They recognized that information flows through arrays of
cells and that the structure of the cells shapes the passage of information
through the brain. In the middle of this century, the role of ion flux in the
movement of information along axons was established. The electron microscope and
the microelectrode helped to explain information transfer at the synapse, and
study of the modulation of synaptic strength is currently a major area of
neuroscience research. The origin of the many types of neuron seen by the early
anatomists remains enigmatic, but the solution to this mystery is now emerging.
The identification of stem cells and of the mechanisms that control their
differentiation into distinct neuron types will contribute to a new understanding
of both the origin of neuronal types and neuronal circuits. The current
enthusiasm for stem cells is stimulated by interest from both the academic and
nonacademic communities. These enthusiasts recognize a simple truth, that the
cells are smart; they are the agents that control cell number and type in the
brain. They create the structure that generates the higher order brain function.
If these premises are true, then in the new century our understanding of the
nervous system will be transformed by the facts of stem cell biology. J.
Neurosci. Res. 59:298-300, 2000. Published 2000 Wiley-Liss, Inc.
PMID- 10679765
TI - Early cortical precursors do not undergo LIF-mediated astrocytic differentiation.
AB - Multipotential stem cells have been isolated from the developing and adult CNS.
Similar identified factors control the differentiation of these cells. A striking
example is the instructive action of CNTF/LIF activating the JAK/STAT pathway to
induce astrocytic differentiation in both fetal and adult CNS stem cells. Here we
show that E12 cortical precursors express functional LIF receptors but do not
exhibit this differentiation response to CNTF/LIF either in explant or in
dissociated cell culture. The lack of response to LIF-induced astrocytic
differentiation is maintained in cocultures with LIF responsive cells derived
from E15 cortex. This suggests cell intrinsic differences between early and late
stage precursors in the interpretation of LIF-mediated signaling; however, the
early nestin-positive precursor population differentiates into both neurons and
neural crest derivatives. These data define differences between CNS stem cells
from different stages of cortical development. J. Neurosci. Res. 59:301-311,
2000. Published 2000 Wiley-Liss, Inc.
PMID- 10679766
TI - Developmental changes in neural progenitor cell lineage commitment do not depend
on epidermal growth factor receptor signaling.
AB - Multipotent neural progenitor cells become progressively more biased towards a
glial fate during development coincident with an increase in expression of the
epidermal growth factor receptor (EGFR). To determine whether differences in
lineage commitment of neural progenitor cells from different stages are causally
related to expression of the EGFR and whether generation of glia is EGFR
dependent, we used an EGFR-specific tyrosine kinase inhibitor, PD158780, to block
the activation of EGFR in progenitor cells. Treatment of cultured neonatal
progenitor cells with PD158780 completely blocked EGF-induced proliferation of
the cells but did not affect bFGF-induced proliferation. Nevertheless, treatment
with the inhibitor failed to inhibit the generation of astroglia in the presence
of either EGF or bFGF. Treatment with bone morphogenetic protein-2 (BMP2)
enhanced astroglial differentiation and suppressed oligodendroglial (OL)
differentiation. PD158780 treatment had no effect on the BMP2-induced astroglial
differentiation or OL suppression. These observations suggest that the generation
of astroglia is not dependent on EGFR activation. Because it was still possible
that the progenitor cell responses reflected a prior history of EGFR signaling,
rat forebrain cells were cultured in the presence of PD158780 from a time (E12.5)
preceding expression of the EGFR. After time in culture, the E12.5 cells
expressed EGFR by Western analysis both in the presence and in the absence of
PD158780, but activation of EGFR kinase (receptor autophosphorylation) was
undetectable in the presence of PD158780 and the cells did not proliferate in
response to EGF. Nevertheless, astroglial differentiation was normal in PD158780
treated cells both in the absence and in the presence of BMPs or CNTF.
Furthermore, the propensity towards glial differentiation increased with time in
culture even in the absence of EGFR signaling. This suggests that the increased
bias towards glial differentiation during development does not depend on EGFR
signaling.
PMID- 10679768
TI - Endogenous IGF-1 regulates the neuronal differentiation of adult stem cells.
AB - Stem cells from the adult forebrain of mice were stimulated to form clones in
vitro using fibroblast growth factor-2 (FGF-2). At concentrations above 10 ng/ml
of FGF-2, very few clones gave rise to neurons; however, if FGF-2 was removed
after 5 days, 20-30% of clones subsequently gave rise to neurons. The number of
neuron-containing clones and the number of neurons per clone was significantly
enhanced, if insulin-like growth factor (IGF)-1 or heparin were added subsequent
to FGF-2 removal. The spontaneous production of neurons after FGF-2 removal was
shown to be due to endogenous IGF-1, since antibodies to IGF-1 and an IGF-1
binding protein totally inhibited neuronal production. Similarly, these reagents
also abrogated the neuron-promoting effects of heparin. Thus, it appears that
endogenous IGF-1 may be a major regulator of stem cell differentiation into
neurons. Furthermore, it was found that high levels of IGF-1 or insulin promoted
the maturation and affected the neurotransmitter phenotype of the neurons
generated.
PMID- 10679767
TI - Promoter-targeted selection and isolation of neural progenitor cells from the
adult human ventricular zone.
AB - Adult humans, like their nonhuman mammalian counterparts, harbor persistent
neural progenitor cells in the forebrain ventricular lining. In the absence of
adequate surface markers, however, these cells have proven difficult to isolate
for study. We have previously identified and selected neural progenitor cells
from both the fetal and adult rodent ventricular zone (VZ), by sorting forebrain
cells transfected with plasmid DNA encoding the gene for green fluorescent
protein driven by the early neuronal promoter for Talpha1 tubulin
(P/Talpha1:hGFP). We have now extended this approach by purifying both
P/Talpha1:hGFP tubulin-defined neuronal progenitors, as well as potentially less
committed E/nestin:hGFP-defined neural progenitor cells, from the adult human VZ.
The ventricular wall of the temporal horn of the lateral ventricle was dissected
from temporal lobes obtained from four adult patients undergoing therapeutic
lobectomy. These samples were dissociated, and the cultured cells transduced with
either P/Talpha1:hGFP or E/nestin:EGFP plasmid DNA. A week later, the cells were
redissociated, selected via fluorescence-activated cell sorting (FACS) on the
basis of neural promoter-driven GFP expression, and replated. The majority of
these cells expressed the early neuronal protein betaIII-tubulin upon FACS;
within the week thereafter, most matured as morphologically evident neurons that
coexpressed betaIII-tubulin and microtubule-associated protein (MAP)-2. Many of
these neurons had incorporated bromodeoxyuridine in vitro in the days before
FACS, indicating their mitogenesis in vitro. Thus, the use of fluorescent
transgenes under the control of early neural promoters permits the enrichment of
neuronal progenitor cells from the adult human ventricular zone. The specific
acquisition, in both purity and number, of residual neural progenitor cells from
the adult human brain may now permit hitherto unfeasible studies of both their
biology and practical application.
PMID- 10679769
TI - Motoneuron differentiation of immortalized human spinal cord cell lines.
AB - Human motoneuron cell lines will be valuable tools for spinal cord research and
drug discovery. To create such cell lines, we immortalized
NCAM(+)/neurofilament(+) precursors from human embryonic spinal cord with a
tetracycline repressible v-myc oncogene. Clonal NCAM(+)/neurofilament(+) cell
lines differentiated exclusively into neurons within 1 week. These neurons
displayed extensive processes, exhibited immunoreactivity for mature neuron
specific markers such as tau and synaptophysin, and fired action potentials upon
current injection. Moreover, a clonal precursor cell line gave rise to multiple
types of spinal cord neurons, including ChAT(+)/Lhx3(+)/Lhx4(+) motoneurons and
GABA(+) interneurons. These neuronal restricted precursor cell lines will
expedite the elucidation of molecular mechanisms that regulate the
differentiation, maturation and survival of specific subsets of spinal cord
neurons, and the identification and validation of novel drug targets for
motoneuron diseases and spinal cord injury.
PMID- 10679770
TI - Trophic factors: An evolutionary cul-de-sac or door into higher neuronal
function?
AB - Trophic factors, such as the neurotrophins, CNTF, and GDNF, represent unique
families of proteins that are essential for the development of the vertebrate
nervous system. Surprisingly, there is little evidence to date that these
proteins exist in Drosophila melanogaster and Caenorhabditis elegans, even though
other polypeptide growth factors, such as EGF, FGF, and insulin, are conserved in
these species. For the neurotrophins, the evolution of NGF, BDNF, NT-3, and NT-4
as a family implies that these signaling molecules may be involved in mediating
additional neural activities, such as learning, memory, and behavior. Indeed,
there is abundant evidence now that BDNF is involved in synapse modification,
neurotransmitter release, long-term potentiation, and mechanosensation. The
widening scope of neurotrophin action will require more physiological, genomic,
and integrative approaches to understand fully the mechanisms by which survival
factors can mediate so many diverse effects.
PMID- 10679771
TI - Association of the Abl tyrosine kinase with the Trk nerve growth factor receptor.
AB - Nerve growth factor (NGF) initiates the majority of its biological effects by
promoting the dimerization and activation of the tyrosine kinase receptor TrkA.
In addition to rapid increases in the phosphorylation of phosphatidylinositol 3'
kinase (PI 3-kinase) and phospholipase C-gamma and increased ras activity,
phosphorylation of c-Crk and paxillin proteins has been observed upon TrkA
activation. The c-Abl tyrosine kinase is involved in the control of the axonal
cytoskeleton and is known to interact with c-Crk proteins. Here we have tested
the possibility that TrkA receptors might form an association with the c-Abl
protein. After transfection in 293T cells, TrkA and c-Abl kinases could be
coimmunoprecipitated. This interaction did not require TrkA receptors to be
autophosphorylated. Mapping analysis indicated that the region of c-Abl
association was confined to the juxtamembrane region of TrkA. The interaction of
c-Abl with TrkA was also observed in differentiated pheochromocytoma PC12 cells.
These results suggest that c-Abl may be recruited to the NGF receptor complex and
be involved in regulating specific phosphorylation events that occur during
neuronal differentiation.
PMID- 10679772
TI - Differential effects of TrkC isoforms on sensory axon outgrowth.
AB - Neurotrophins are powerful regulators of neuronal morphology. Several lines of
evidence are consistent with the idea that characteristic axonal and dendritic
morphologies throughout the nervous system may be determined by local patterns of
neurotrophin and neurotrophin receptor expression. Neurotrophin receptor tryosine
kinases (Trks) exist in both tyrosine-containing (TK+) and tyrosine-lacking (TK-)
isoforms, both of which are expressed in many neuronal populations. However,
ratios of TK+ to TK- isoforms may vary at different stages of development and may
be differentially distributed to cellular compartments. To test whether these
isoforms have different functions related to axon outgrowth, full-length or
tyrosine kinase-lacking TrkC receptors were overexpressed in embryonic dorsal
root ganglion neurons maintained in explant cultures in neurotrophin-3 (NT-3)
containing media. Neurons were transfected with plasmid DNA encoding enhanced
yellow fluorescent protein (EYFP) and TrkC receptor isoforms by particle-mediated
gene transfer. Control neurons possessed 3.7 +/- 1.3 primary processes and 113.8
+/- 46 branch points. About 80% of the branches were located along the distal
part of the axon. Transfection with the trkC TK+ increased the number of primary
processes (6.5 +/- 2.8), whereas transfection with trkC TK- reduced the formation
of primary processes (3.0 +/- 1.3). Surprisingly, the distribution of branch
points was shifted to the proximal region of axons in neurons transfected with
trkC TK-. These observations are consistent with the idea that differential
expression of Trk isoforms during development may sculpt axonal morphology.
PMID- 10679773
TI - TrkB expression and early sensory neuron survival are independent of endogenous
BDNF.
AB - Sensory neurons initially survive independently of neurotrophins in culture
during the stage of development when their axons are growing to their targets.
Because mRNAs encoding brain-derived neurotrophic factor (BDNF) and its receptor
tyrosine kinase TrkB are detectable in subsets of sensory neurons from the
earliest stages of their development, we investigated whether a BDNF autocrine
loop is responsible for sustaining the survival of these neurons during this
early stage in their development. Low-density dissociated cultures of nodose and
dorsal root ganglion neurons were established from wild type and BDNF(-/-) mouse
embryos at this stage and were grown in defined medium without added
neurotrophins. Wild type and BDNF-deficient neurons survived equally well under
these conditions, indicating that a BDNF autocrine loop does not play a role in
sustaining the survival of sensory neurons during the earliest stages of their
development. As sensory axons approach their targets, TrkB expression increases
in a subset of neurons that becomes dependent on BDNF produced by other cells.
Because numerous studies have shown that neurotrophins, including BDNF, increase
expression of their receptors, we investigated whether endogenous BDNF is
required for the increase in TrkB expression observed during stage of
development. Quantitative reverse transcriptase-polymerase chain reaction (RT
PCR) showed that the developmental increase in TrkB mRNA expression occurred
normally in the sensory ganglia of BDNF(-/-) embryos. Taken together, our studies
of sensory neuron development in BDNF-deficient embryos have demonstrated that
endogenous BDNF is neither required for the early survival of these neurons nor
for the induction of TrkB expression.
PMID- 10679774
TI - Reduction of endogenous TGF-beta increases proliferation of developing adrenal
chromaffin cells in vivo.
AB - Chromaffin cells and sympathetic neurons are derivatives of the sympathoadrenal
cell lineage of the neural crest. Although they are similar with respect to many
cell biological aspects, chromaffin cells, in contrast to sympathetic neurons,
continue to synthesize DNA and proliferate through their whole life span. Large
numbers of neural and hormonal signals have been implicated in the regulation of
chromaffin cell proliferation based on in vitro studies. We have previously shown
that chromaffin cells synthesize and release transforming growth factor-beta (TGF
beta) and that exogenously applied TGF-beta suppresses chromaffin cell
proliferation in vitro. We show now that TGF-beta is also a physiologically
relevant factor in the control of cell division in developing chromaffin cells.
We have neutralized endogenous TGF-beta in quail embryos using a monoclonal
antibody recognizing all three TGF-beta isoforms, TGF-beta1, -beta2, and -beta3.
Embryos deprived of TGF-beta show a prominent increase in numbers of tyrosine
hydroxylase (TH)-immunoreactive adrenal chromaffin cells and TH-positive cells
incorporating 5'-bromo-2'deoxyuridine. This is the first documentation of the
physiological significance of a factor that has been suggested to play a role in
the regulation of chromaffin cell mitosis based on in vitro experiments.
PMID- 10679775
TI - Development of the interstitial cell of Cajal: origin, kit dependence and
neuronal and nonneuronal sources of kit ligand.
AB - Kit is a marker for interstitial cells of Cajal (ICC). ICCs interact with enteric
neurons and are essential for gastrointestinal motility. The roles of neural
crest-derived cells, neurons, Kit, and Kit ligand (KL) in ICC development were
analyzed. ICC development lagged behind that of neurons and smooth muscle.
Although mRNA encoding Kit and KL was detected at E11, Kit-immunoreactive ICCs
did not appear until E12 in foregut and E14 in terminal hindgut. Transcripts of
Kit and KL and Kit-immunoreactive cells were found in aganglionic gut from ls/ls
and c-ret -/- mice. ICCs also developed in crest-free cultures of ls/ls terminal
colon. ICCs appeared in cultures of noncrest- but not those of crest-derived
cells isolated from the fetal bowel by immunoselection with antibodies to
p75(NTR). KL immunoreactivity was coincident in cells with neuronal or smooth
muscle markers. The development of ICCs in cultures of mixed cells dissociated
from the fetal gut was dependent on plating density. No ICCs appeared at
=80,000 cells/ml, but many cells, including filamentous ICCs, appeared at
>/=200,000 cells/ml. Exogenous KL partially substituted for a high plating
density. These data support the ideas that mammalian ICCs are neither derived
from the neural crest nor developmentally dependent on neurons. ICC
differentiation/survival requires KL, which can be provided by neurons or cells
in a smooth muscle lineage. Neurons may be needed for development of myenteric
ICCs and the mature ICC network.
PMID- 10679776
TI - Neurite outgrowth can be modulated in vitro using a tetracycline-repressible gene
therapy vector expressing human nerve growth factor.
AB - The delivery of neurotrophic factors to the adult nervous system has potential
applications for the treatment of neurodegenerative diseases and trauma. In vivo
and ex vivo gene therapy offer a means of delivering growth factors and other
therapeutic substances to the central nervous system (CNS) in an
intraparenchymal, accurately targeted, and regionally restricted manner. Ideally,
gene therapy delivery systems should also be regulatable, allowing exogenous
control of amount of gene product delivery. In the present experiment, a
tetracycline-regulatable gene expression system was generated to determine
whether controllable release of nerve growth factor (NGF) and green fluorescent
protein (GFP) from primary rat fibroblasts could modulate biological responses
(neurite outgrowth) in vitro. Using a tetracycline-repressible construct, it was
found that NGF mRNA, NGF protein, and NGF-induced neurite outgrowth could be
tightly regulated within a 24 hour period, and in a dose-dependent fashion, by
exposure to the tetracycline analog doxycycline. Similarly, levels of green
fluorescence could be regulated in GFP-transfected cells. These findings in a
neurobiological system lay the framework for future studies using regulated
neurotrophin delivery in in vivo models of neurodegenerative diseases and CNS
injury.
PMID- 10679777
TI - Glial differentiation and lineages.
PMID- 10679778
TI - Local control of oligodendrocyte development in isolated dorsal mouse spinal
cord.
AB - The earliest oligodendrocyte precursors have been proposed to arise in the
ventral ventricular zone of the embryonic thoraco-lumbar spinal cord and
subsequently migrate to populate dorsal spinal cord. Using the expression of O4
immunoreactivity to define cells of the oligodendrocyte lineage, the development
of oligodendrocytes in different regions of the mouse spinal cord was assayed.
Consistent with earlier studies in other species, isolated explants of E11
ventral but not dorsal mouse spinal cord developed oligodendrocytes after 7 days
in vitro. In contrast, in cultures derived from E13 embryos O4(+)
oligodendrocytes developed in both ventral and dorsal cultures after 5 days in
vitro. These data are consistent with a ventral to dorsal migration of committed
oligodendrocyte progenitors occurring between E11 and E13. Although isolated
early embryonic dorsal spinal cord does not give rise to oligodendrocytes in
short term cultures, in long term cultures O4(+) cells develop in a subset of
dorsal explants. After 10 days in vitro approximately 25% of both cervical and
thoraco-lumbar E11 derived dorsal explants contained significant numbers of O4(+)
cells. The molecular requirements for the dorsally-derived oligodendrocytes was
similar to that in ventral cord. The appearance of O4(+) cells was dependent on
sonic hedgehog and enhanced by neuregulin. These data suggest that early
embryonic dorsal mouse spinal cord has an independent potential to generate
oligodendrocytes under appropriate conditions. Whether this potential is realized
during normal spinal cord development is currently unknown.
PMID- 10679779
TI - Tracing human oligodendroglial development in vitro.
AB - Human neural precursor cell cultures (neurospheres) were established from fetal
brain tissues of 15-20 gestation weeks and propagated for over a year in the
presence of epidermal growth factor, basic fibroblast growth factor and leukemia
inhibitory factor. Neurospheres were differentiated without the presence of above
growth factors to follow the development of oligodendroglia. Oligodendroglial
progenitors, identified by their bipolar morphology and expression of platelet
derived growth factor receptor-alpha (PDGFRalpha), emerged from spheres as early
as 1 DIV; O4+ cells with bipolar to multipolar processes were observed at 3 DIV
whereas O1+ multiprocess-bearing oligodendroglia did not appear until 5-7 DIV.
They further differentiated to myelin basic protein-expressing oligodendrocytes
after 2-3 weeks in culture. Thus, human oligodendroglial maturation in vitro
follows the same pathway as rat cells but takes twice as long as their rodent
counterparts. Bromodeoxyuridine incorporation indicated that PDGFRalpha
expressing cells but not O4+ oligodendroglia proliferated. More oligodendroglial
progenitors incorporated BrdU and more O4+ cells survived when they were in
contact with neurons and astrocytes than when they developed beyond the astrocyte
layer. In addition, oligodendroglia on astrocytes had a complex process branching
whereas those growing beyond astrocyte layer often formed membrane sheaths. Thus
the survival, proliferation and maturation of oligodendroglia are influenced by
other cell types.
PMID- 10679780
TI - Analysis of oligodendroglial differentiation using cDNA arrays.
AB - We used cDNA arrays to investigate molecular aspects of the differentiation of an
immortalized line of oligodendroglial progenitors, and of immunopan-purified
primary cultures of oligodendroglial progenitors, to immature oligodendroglia.
Developmental regulation of the proteolipid and 2-hydroxyacylsphingosine 1
galactosyltransferase genes was tighter in the primary than in the immortalized
cells. Our data suggest that increased expression of genes encoding the following
proteins are involved in oligodendroglial differentiation: Fyn, Erk, p85, G-alpha
12 guanine nucleotide binding, and transducin beta-2 signal transduction
molecules; glial maturation factor; the proteasomal subunits C8 and C3; the
proteasomal targeting molecule polyubiquitin; the cell cycle regulatory proteins
Set, protein phosphatase 2A, and nuclear tyrosine phosphatase (PRL-1); and the
high-affinity glutamate cotransporter EAAC-1.
PMID- 10679781
TI - Oligodendrocytes as glucocorticoids target cells: functional analysis of the
glycerol phosphate dehydrogenase gene.
AB - Previous research has established that the development and function of
oligodendrocytes are influenced by glucocorticoids. The enzyme glycerol phosphate
dehydrogenase (E.C.1.1.1.8) has been used as a model to study glucocorticoid
regulation of gene expression in oligodendrocytes and the C6 glial cell line. In
the rat brain this enzyme is exclusively localized to oligodendrocytes. The
sequence of the 5' flanking region for the rat gene encoding Glycerol Phosphate
Dehydrogenase (GPDH; EC 1.1.1.8) was determined. 4 kb of sequence from the 5'
flanking region, exon 1, and part of intron 1 of the rat GPDH gene was compared
to the corresponding mouse sequence. Dotplot matrix comparison revealed that the
rat sequence is more than 80% similar to the mouse sequence, but differs from the
mouse sequence in two regions: the rat sequence is devoid of 200 bp of B1 repeat
sequence that is present in the mouse, and the rat sequence has an excess 700 bp
of B2 repeat sequence inserted between -0.7 kb and -1. 4 kb that is absent in the
mouse. To determine the regulatory activity of the rat GPDH 5' flanking region,
various portions of the rat GPDH 5' flanking region were placed in luciferase
reporter constructs and tested for transcriptional activity. Transient
transfection of reporter constructs into the C6 glial cell line revealed that the
distal end of the 5' flanking region was glucocorticoid-inducible. A 385 bp
Glucocorticoid Response Unit (GRU) was identified whose glucocorticoid induction
was enhanced by dibutyryl-cAMP and reduced by phorbol esters. Sequence analysis
of the GRU revealed the presence of four consensus GRE sequences and other
putative consensus elements. Results here suggest that the 5' flanking region of
the GPDH gene mediates the ligand-inducible regulation of GPDH, and that multiple
signaling pathways converge at the 5' regulatory sequence to modulate GPDH gene
expression in oligodendrocytes.
PMID- 10679782
TI - Expression of rab GTP-binding proteins during oligodendrocyte differentiation in
culture.
AB - Oligodendrocytes (OLs) synthesize and transport vast amounts of proteins and
lipids from the cell body to the morphologically and biochemically distinct
domains of the myelin membrane. From our prediction that regulators of vesicular
transport should be up-regulated at the time of myelin production, we
hypothesized that the up-regulated and unidentified small GTPases found by Huber
et al. [1994a] may be Rab proteins. We have analyzed the mRNA expression of rabs
in OLs, and have detected rabs 10, 11b, 18, 24, 26, and 28 in addition to rabs
that were found previously. Our data show that among the Rabs so far detected
during differentiation, only Rabs 5a and 8a exhibited up-regulation in addition
to the previously published Rab3a (Madison et al. [1999], J. Neurochem. 72:988
998). We discuss the limited extent of up-regulation of rabs in the context of
the presumed necessity for an increase in Rab activity during myelin assembly.
PMID- 10679783
TI - Localization of brain-derived neurotrophic factor and TrkB receptors to
postsynaptic densities of adult rat cerebral cortex.
AB - Although neurotrophins are critical for neuronal survival and differentiation,
recent studies suggest that they also regulate synaptic plasticity. Brain-derived
neurotrophic factor (BDNF) rapidly increases synaptic transmission in hippocampal
neurons, and enhances long-term potentiation (LTP), a cellular and molecular
model of learning and memory. Loci and precise mechanisms of BDNF action remain
to be defined: evidence supports both pre- and postsynaptic sites of action. To
help elucidate the synaptic mechanisms of BDNF action, we used antisera directed
against the extracellular and intracellular domains of trkB receptors, anti
trkBout and anti-trkBin, respectively, to localize the receptors in relation to
synapses. Synaptic localization of BDNF was examined in parallel using anti-BDNF
antisera. By light microscopy, trkBin and trkBout immunoreactivities were
localized to hippocampal neurons and all layers of the overlying visual cortex.
Immunoelectron microscopic analysis of the cerebral cortex revealed that trkB and
BDNF localize discretely to postsynaptic densities (PSD) of axo-spinous
asymmetric synaptic junctions, that are the morphological correlates of
excitatory, glutamatergic synapses. TrkB immunoreactivity was also detected in
the nucleoplasm by light and electron microscopy. Western blot analysis indicated
that both anti-trkBout and anti-trkBin antisera react with a protein band in the
PSD corresponding to the molecular weight expected for trkB; however, molecular
species distinct from that for trkB were recognized in the nuclear fraction by
both anti-trkBin and anti-trkBout antisera, indicating that the nuclear
immunoreactivity, seen by immunocytochemistry, reflects cross-reactivity with
proteins closely related to, but distinct from, trkB. The PSD localization of
both BDNF and trkB supports the contention that this receptor/ligand pair
participates in postsynaptic plasticity.
PMID- 10679784
TI - Obituary
PMID- 10679785
TI - Spatiotemporal development of oligodendrocytes in the embryonic brain.
AB - In the central nervous system (CNS), oligodendrocytes have long been considered
to be the last cell type to be generated during development. In rodents, the
progenitor cells that give rise to oligodendrocytes have been reported to
originate in the subventricular zone. Here, we review recent data demonstrating
the existence of oligodendrocyte precursor cells in the ventricular layer of the
neural tube that emerge prior to the progenitor stage. Oligodendrocyte precursors
arise in restricted foci that are distributed along the rostrocaudal axis of the
neural tube, for the most part ventrally. The generation of oligodendrocyte
precursor cells occurs either simultaneously with, or follows closely upon the
emergence of the first neurons. Experiments with quail-chick chimeras provide
evidence that oligodendrocyte progenitors derived from ventricular precursors
migrate either tangentially or radially to colonize extensive or segmentally
restricted territories of the brain. The choice depends on their site of origin.
Finally, we discuss the possibility that oligodendrocytes could be a mosaic
population that originates from at least two types of precursor cells.
PMID- 10679786
TI - Oligodendrocytes and the control of myelination in vivo: new insights from the
rat anterior medullary velum.
AB - The rat anterior medullary velum (AMV) is representative of the brain and spinal
cord, overall, and provides an almost two-dimensional preparation for
investigating axon-glial interactions in vivo. Here, we review some of our
findings on axon-oligodendrocyte unit relations in our adult, development, and
injury paradigms: (1) adult oligodendrocytes are phenotypically heterogeneous,
conforming to Del Rio Hortega's types I-IV, whereby differences in
oligodendrocyte morphology, metabolism, myelin sheath radial and longitudinal
dimensions, and biochemistry correlate with the diameters of axons in the unit;
(2) oligodendrocytes derive from a common premyelinating oligodendrocyte
phenotype, and divergence of types I-IV is related to the age they emerge and the
presumptive diameter of axons in the unit; (3) during myelination, axon
oligodendrocyte units progress through a sequence of maturation phases, related
to axon contact, ensheathment, establishment of internodal myelin sheaths, and
finally the radial growth and compaction of the myelin sheath; (4) we provide
direct in vivo evidence that platelet-derived growth factor-AA (PDGF-AA),
fibroblast growth factor (FGF-2), and insulin-like growth factor-I (IGF-I)
differentially regulate these events, by injecting the growth factors into the
cerebrospinal fluid of neonatal rat pups; (5) in lesioned adult AMV, transected
central nervous system (CNS) axons regenerate through the putatively inhibitory
environment of the glial scar, but remyelination by oligodendrocytes is
incomplete, indicating that axon-oligodendrocyte interactions are defective; and
(6) in the adult AMV, cells expressing the NG2 chondroitin sulphate have a
presumptive adult oligodendrocyte progenitor antigenic phenotype, but are highly
complex cells and send processes to contact axolemma at nodes of Ranvier,
suggesting they subserve a specific perinodal function. Thus, axons and
oligodendrocyte lineage cells form interdependent functional units, but
oligodendrocyte numbers, differentiation, phenotype divergence, and
myelinogenesis are governed by axons in the units, mediated by growth factors and
contact-dependent signals.
PMID- 10679787
TI - Hepatocyte growth factor protects cultured rat cerebellar granule neurons from
apoptosis via the phosphatidylinositol-3 kinase/Akt pathway.
AB - Recent studies suggest that hepatocyte growth factor (HGF) functions as a
neurotrophic factor in the central nervous system. In this study, we investigated
the neuroprotective effect of HGF and its mechanism of action. We used cultured
cerebellar granule neurons that underwent apoptosis when the culture medium was
changed from that containing serum with 25 mM K(+) to serum-free medium
containing 5 mM K(+), and HGF prevented apoptotic cell death. HGF stimulated both
mitogen-activated protein (MAP) kinase and phosphatidylinositol-3 (PI3)-kinase
activity in cerebellar granule neurons. Two specific inhibitors of PI3-kinase,
wortmannin and LY294002, efficiently blocked this neuroprotective effect of HGF.
In contrast, PD98059, a selective inhibitor of MAP kinase kinase (MEK), did not
affect the anti-apoptotic effect of HGF. The downstream signal of PI3-kinase in
this protection was further investigated. HGF-induced phosphorylation of Akt and
pretreatment of the cells with wortmannin completely impaired Akt activation.
These results suggest that HGF prevents apoptosis in cerebellar granule neurons
via the PI3-kinase/Akt pathway.
PMID- 10679788
TI - Neuroprotective effects of a new glutathione peroxidase mimetic on neurons of the
chick embryo's retina.
AB - During their period of naturally occurring neuronal death, retinal ganglion cells
are particularly vulnerable to axotomy. The resulting cell death requires protein
synthesis and is redox-regulated, since antioxidants protect axotomized-ganglion
cells when given in doses that maintain the redox status near an optimal set
point. Here we report the effects of BXT-51072, a new glutathione peroxidase
mimetic, on ganglion cell death induced in various ways in the retinas of chick
embryos. The intraocular injection of BXT-51072 protected axotomized neurons at
doses in a narrow (tenfold) range. It also reduced the deleterious effects of
intraocular tert-butyl hydroperoxide, an inducer of lipid peroxidation, and
diminished the excitotoxic degeneration induced by N-methyl-D-aspartate. However,
BXT-51072 did not noticeably reduce naturally occurring cell death. Globally, our
results show that BXT-51072 has numerous protective effects in the retina. In
accordance with published data, the present report indicates that glutathione
peroxidase mimetics may have potential applications for neurologic or
degenerative diseases.
PMID- 10679789
TI - Differentiation of rat striatal embryonic stem cells in vitro: monolayer culture
vs. three-dimensional coculture with differentiated brain cells.
AB - Several groups have demonstrated the existence of self-renewing stem cells in
embryonic and adult mouse brain. In vitro, these cells proliferate in response to
epidermal growth factor, forming clusters of nestin-positive cells that may be
dissociated and subcultured repetitively. Here we show that, in stem cell
clusters derived from rat embryonic striatum, cell proliferation decreased with
increasing number of passages and in response to elevated concentrations of
potassium (30 mM KCl). In monolayer culture, the appearance of microtubule
associated protein type-5-immunoreactive (MAP-5(+)) cells (presumptive neurons)
in response to basic fibroblast growth factor (bFGF) was reduced at low cell
density and with increasing number of passages. In the presence of bFGF, elevated
potassium caused a more differentiated neuronal phenotype, characterized by an
increased proportion of MAP-5(+) cells, extensive neuritic branching, and higher
specific activity of glutamic acid decarboxylase. Dissociated stem cells were
able to invade cultured brain cell aggregates containing different proportions of
neurons and glial cells, whereas they required the presence of a considerable
proportion of glial cells in the host cultures to become neurofilament H
positive. The latter observation supports the view that astrocyte-derived factors
influence early differentiation of the neuronal cell lineage.
PMID- 10679790
TI - Multilamellar packing of myelin modeled by lipid-bound MBP.
AB - Membrane compaction and adhesion at the major dense line (cytoplasmic apposition)
of myelin, particularly in the central nervous system (CNS), is typically
attributed to myelin basic protein (MBP). To explore the role of MBP in myelin
membrane adhesion, we attempted to reconstitute the major dense line of myelin
from purified lipid-bound MBP, which is a detergent-soluble form of MBP that
retains the binding of all the myelin lipids. Removal of detergent by long-term
dialysis yielded a precipitate, which, when analyzed by sodium dodecylsulfate
polyacrylamide gel electrophoresis (SDS-PAGE) and thin-layer chromatography,
contained MBP that was still associated with myelin lipids, but in different
proportions than in the native membrane. Comparison of lipid composition among
isolated myelin, MBP-free myelin lipids, and lipid-bound MBP aggregates showed
that the lipid-bound form of the protein was specifically enriched in
phosphatidylethanolamine, phosphatidylcholine, sphingomyelin,
phosphatidylinositol, and phosphatidylserine. Electron microscopy and x-ray
diffraction demonstrated that the lipid-MBP complexes formed multilayers having
periods of 70-85 A, which correspond in width to individual myelin membranes. By
contrast, the lipids alone assembled as multilayers having a period of
approximately 40 A. Thus, the detergent-soluble form of MBP, which is bound to
lipids, might serve as a simple model for the cytoplasmic apposition of myelin.
PMID- 10679791
TI - Visualization of beta-amyloid peptide (Abeta) phagocytosis by human mononuclear
phagocytes: dependency on Abeta aggregate size.
AB - Previous studies from this laboratory have shown that human monocytes exposed to
beta-amyloid peptide (Abeta) exert a graded neurotoxic response in an organotypic
brain culture paradigm. Moreover, this toxicity can be reduced by compounds that
inhibit cell motility and phagocytosis, suggesting that internalization of Abeta
may be a requirement for neurotoxic action. To confirm that Abeta is indeed
phagocytosed by monocytes and to further lay the groundwork for resolving the
possible linkage between this process and neurotoxicity, we examined
Abeta:monocyte interactions using immunocytochemistry and fluorescence
histochemistry followed by confocal microscopy and three-dimensional image
reconstruction. Internalization of Abeta was detected by 24 hr following exposure
of monocytes to the purified peptide, and the relative efficacy of this process
appeared to be influenced by the size of the Abeta aggregates. Specifically,
smaller aggregates were observed to be more efficiently internalized, while
larger Abeta masses tended to reside only on the monocyte surface, apparently
bound to several monocytes at once. Both colchicine and cytochalasin D,
cytoskeletal perturbants that block phagocytosis, caused Abeta to accumulate in
deep pits within monocytes and inhibited complete envelopment by monocyte
cytoplasm. These results suggest that monocytes can indeed phagocytose aggregates
of Abeta and that this process may be critical in activating these cells to a
neurocytopathic state. Accordingly, interference of Abeta phagocytosis by
monocytes or monocyte-derived cells may be a novel target for therapeutic action.
PMID- 10679792
TI - A panel of epitope-specific antibodies detects protein domains distributed
throughout human alpha-synuclein in Lewy bodies of Parkinson's disease.
AB - To facilitate studies of the normal biology of alpha-synuclein, a member of a
family of neuronal proteins of unknown function, and to elucidate the role of
alpha-synuclein pathologies in neurodegenerative diseases, we generated and
characterized a panel of anti-synuclein antibodies. Here we demonstrate that
these antibodies recognize defined epitopes spanning the entire length of human
alpha-synuclein, and that some of these antibodies also cross-react with zebra
finch and rodent synucleins. Since alpha-synuclein has been reported to be a
major component of Lewy bodies (LBs) in Parkinson's disease (PD), dementia with
LBs and common variants of Alzheimer's disease, we performed immunohistochemical
studies showing that these antibodies label numerous LBs in the PD substantia
nigra, thereby localizing protein domains throughout human alpha-synuclein in
LBs. Taken together, our data indicate that this panel of antibodies can be
exploited to probe the normal biology of alpha-synuclein as well as the role of
pathological forms of this protein in PD and related neurodegenerative
synucleinopathies.
PMID- 10679793
TI - Lobster GABA receptor subunit expressed in neural tissues.
AB - A cDNA encoding an ionotropic gamma-aminobutyric acid (GABA) receptor subunit was
isolated from a lobster (Homarus americanus) cDNA library. A longer version of
this cDNA, containing a 108-bp insert, was also detected. The two cDNAs are
predicted to encode alternatively spliced proteins of 485 and 521 amino acids,
respectively. The sequences were most similar to the Drosophila RDL (resistance
to dieldrin) GABA subunit with 54% identity, and 30-35% identity with vertebrate
ionotropic GABA receptor subunits. Only the shorter clone formed functional ion
channels when transfected into human embryonic kidney (HEK) 293 cells. GABA
caused a Cl(-)-selective current in the presence of GABA that was blocked by
picrotoxin. The GABA-induced current was weakly sensitive to the GABA(A)
antagonist, bicuculline, but was enhanced by pentobarbital. Expression of the
GABA receptor mRNA was highest in brain and the olfactory organ, but was not
detected in leg muscle. These data suggest that the isolated cDNAs are likely to
encode proteins that comprise subunits of native GABA receptors expressed in
olfactory receptor neurons and projection neurons of the olfactory deutocerebrum.
PMID- 10679794
TI - Influence of transferrin on manganese uptake in rat brain.
AB - To evaluate the influence of transferrin (Tf) on manganese (Mn) uptake in the
brain, pH 8.6 buffer-treated (54)MnCl(2), which has a higher affinity for Tf than
untreated (54)MnCl(2), and Tf-bound (54)Mn were prepared. When pH 8.6 buffer
treated (54)MnCl(2) and untreated (54)MnCl(2) were incubated with apo-Tf in Tris
(2-amino-2-hydroxymethylpropane-1,3-diol)-HCl buffer, the percentage of the total
(54)MnCl(2) bound to Tf was approximately 85% and 10%, respectively. One hour
after intravenous (iv) injection of pH 8.6 buffer-treated (54)MnCl(2) and
untreated (54)MnCl(2), both tracers were concentrated similarly in the choroid
plexus in the ventricles and distributed in other brain regions. Six days after
iv injection, both pH 8.6 buffer-treated (54)MnCl(2) and untreated (54)MnCl(2)
tracers were concentrated in the superior olivary complex, inferior colliculi,
and red nuclei, although the former radioactivity was lower than the latter.
Moreover, Tf-bound (54)Mn was prepared and injected iv into rats. The
radioactivity from Tf-bound (54)Mn, which was also concentrated in the same
regions, e.g., the superior olivary complex, was the lowest of all three traces.
Tf-bound (54)Mn was stable during incubation with serum for 1 hr. It is likely
that more Mn is transported into the brain when Mn is not bound to Tf. When Tf
bound (54)Mn and (54)MnCl(2) were unilaterally injected into the lateral
ventricle, radioactivity was distributed only around the ipsilateral ventricle in
the Tf-bound (54)Mn group 7 days after injection, whereas it was distributed more
extensively in the (54)MnCl(2) group. It is likely that Tf-bound Mn in the CSF is
less readily transported into the brain parenchymal cells than the non-Tf-bound
form. These results suggest that Mn is transported into the brain efficiently via
a Tf-independent uptake system.
PMID- 10679795
TI - Muscular dystrophy in adult and aged anti-NGF transgenic mice resembles an
inclusion body myopathy.
AB - The role of nerve growth factor (NGF) and its receptors in the physiology of
skeletal muscles has not been extensively studied in animal models. We describe
the production of transgenic lines of mice expressing a neutralizing antibody
against NGF (alphaD11) and the morphological and histochemical analysis of
skeletal muscles from adult and aged anti-NGF mice. This study reveals that the
chronic deprivation of NGF results in a decreased size of myofibers of dorsal and
hindlimb muscles in adult but not in postnatal day (P)2 mice. In myofibers from
adult anti-NGF mice, the presence of central nuclei, vacuolization of the
cytoplasm, and inflammatory cell infiltration was observed. The
immunohistochemical analysis of these muscular fibers revealed an upregulation of
p75 expression, a decrease in adenosine triphosphatase (ATP)ase activity, and a
subsarcolemmal Congo Red-positive staining. Immunostaining with an antibody
against amyloid precursor protein showed an increased labeling of the cytoplasm
of myofibers from adult and aged anti-NGF mice. These features are reminiscent of
human myopathies, such as inclusion body myositis. We conclude that NGF deficits
might be relevant for a class of human myopathies.
PMID- 10679796
TI - Localization of glyoxylate dehydrogenase and glyoxylate-complex molecules in the
rat prefrontal cortex: enzymohistochemical and immunocytochemical study.
AB - Glyoxylic acid is synthesized and catabolized in cells of vertebrates; several
pathways have been described. In previous papers, we have demonstrated the
localization in some areas of the rat cerebral cortex both of beta-NAD-dependent
glyoxylate dehydrogenase (glyoDH), using an enzymohistochemical method, and of
glyoxylate-complex molecules, using immunocytochemical procedures. In this study
we have applied these two techniques in various areas of the prefrontal cortex
with different histological cytoarchitecture. GlyoDH has been located in most
neurons, in some glial cells, and in capillary wall structures in all cortical
layers of all areas of the rat prefrontal cortex. Antibodies against glyoxylate
complex molecules showed positive immunoreactivity in scattered neurons, mostly
of multipolar or stellate appearance, from layers III, IV, and V in the medial
precentral area, but not in cortical areas 24, 25, or 32 of the prefrontal
cortex. Immunoreaction was found in the periphery of neuronal perikarya and in
some of their processes. These results demonstrate the existence of a particular
area-dependent neuronal cortical system, of specific but uncertain function,
related to glyoxylic acid and/or glyoxylate compounds. At the electron microscope
level, positive reaction was associated with synaptic sites, axonal filaments,
glial cells, and several components of the blood-brain barrier. These
localizations suggest the involvement of glyoxylate derivatives in synaptic
functioning and also in glial cell functions.
PMID- 10679797
TI - Membrane asymmetry and DNA degradation: functionally distinct determinants of
neuronal programmed cell death.
AB - The ability to elucidate the molecular mechanisms that modulate programmed cell
death (PCD) may provide the crucial clues to unravel the cellular basis of
neurodegenerative disorders. Employing both a novel assay to follow serially PCD
in individual living neurons and the neuroprotective agent lubeluzole as an
investigative tool, we examined the development of nitric oxide (NO)-induced PCD
over time through the reversible annexin V labelling of membrane
phosphatidylserine (PS) exposure and the electron microscopy of genomic DNA in
primary rat hippocampal neurons. Exposure to the NO generators SNP (300 microM)
or NOC-9 (300 microM) alone increased annexin V-positive neurons in the
population from 7% +/- 4% in untreated cultures to 13% +/- 4% at 1 hr and to 61%
+/- 5% at 24 hr. Administration of a neuroprotective concentration of lubeluzole
(750 nM) at the time of NO exposure initially prevented the exposure of PS
residues, but consistently maintained DNA integrity over a 24 hr period. During
posttreatment paradigms of lubeluzole (750 nM) at 2, 4, and 6 hr following NO
exposure, progression of membrane PS inversion was reversed and subsequently
suppressed over a 24 hr course. Our work illustrates that neuronal PCD is
composed of at least two physiologically distinct and separate pathways that
consist of the externalization of membrane PS residues and the independent
maintenance of genomic DNA integrity. In addition, neuronal injury is fluid and
reversible in nature, suggesting a "window of opportunity" for the repair and
reversal of neurons yet to be committed to PCD.
PMID- 10679798
TI - Peripheral nerve regeneration and cholesterol reutilization are normal in the low
density lipoprotein receptor knockout mouse.
AB - Following peripheral nerve injury, cholesterol from degenerating myelin is
retained locally within macrophages and subsequently reutilized by Schwann cells
for synthesis of new myelin during nerve regeneration. Substantial evidence
indicates this conservation and reutilization of cholesterol is accomplished via
lipoprotein-mediated intercellular transport, although the identities of the
lipoproteins and their receptors are unresolved. Because Schwann cells in
regenerating nerve are reported to express the low-density lipoprotein (LDL)
receptor (LDLR), we used the LDLR knockout mouse to examine the potential role of
this receptor in cholesterol reutilization. Sciatic nerves were crushed in
knockout and wild-type mice and examined 3 days to 10 weeks later. Morphometric
analyses and measures of mRNA levels for myelin protein P(0), indicate that axon
regeneration and myelination proceed normally in the LDLR knockout mouse. We
therefore measured hydroxy-methylglutaryl-coenzyme A (HMG-CoA) reductase activity
and mRNA levels to determine whether Schwann cells compensated for the absence of
the LDLR by upregulating cholesterol synthesis. Unexpectedly, these measures
remained at the same downregulated levels found in regenerating nerves of wild
type animals. The apparently normal nerve regeneration, coupled with the lack of
any compensatory upregulation of cholesterol synthesis in the LDLR knockout mice,
indicates that other lipoprotein receptors must be primarily involved in
cholesterol uptake by Schwann cells.
PMID- 10679799
TI - Activated recombinant human coagulation factor VII (rFVIIa) therapy for abdominal
bleeding in patients with inhibitory antibodies to factor VIII.
AB - Eight patients with inhibitors to factor VIII (4 hemophilia A and 4
nonhemophilic) were treated with recombinant activated factor VII (rFVIIa) to
control severe abdominal bleeding. The recombinant factor was supplied under an
open-label, emergency-use program to patients previously unresponsive to one or
more alternative therapies. Therapy with rFVIIa was administered for nine
separate bleeding events; one patient was treated for two separate bleeding
episodes. Patients were treated for an average of 9 days and received a mean
total dose of 5.2 mg of rFVIIa for control of bleeding. Treatment was considered
successful and hemostasis adequate in 7 of the 9 episodes (78%). Treatment with
rFVIIa was partially successful in one other episode. Four patients in this
series experienced serious adverse events; all the adverse events were considered
unrelated to rFVIIa therapy. The results of this limited series indicate that
rFVIIa is an effective means of managing life-threatening abdominal bleeding in
individuals with hemophilia or acquired antibodies to factor VIII.
PMID- 10679800
TI - High-level, stable expression of blood group antigens in a heterologous system.
AB - The detection and identification of blood group antibodies in patients is crucial
for successful allogeneic blood transfusions. Current methods are highly
subjective and rely on red blood cells (RBCs), which simultaneously express many
blood group antigens, have a short shelf-life, and carry potential biohazard
risks. To overcome these problems, we have used the approach of expressing
individual blood group antigen-bearing proteins in a heterologous system. We
report here the high-level surface expression of type I (Knops), type II (Kell),
and type III/multi-pass (Duffy) membrane proteins that carry blood group antigens
in mouse erythroleukaemic (MEL) cells using a vector containing the beta-globin
locus control region. Importantly, the antigens expressed were detected
specifically by a panel of patients' sera containing alloantibodies at
sensitivities that are comparable to antigen-positive RBCs. Furthermore, in
contrast to other mammalian expression systems, antigen expression was stable
following freezing and thawing of the cell lines. Thus, this system has the
potential both to replace the current use of RBCs by providing a one step method
to detect and identify blood group antibodies and to allow the automation of
antibody identification for the clinical laboratory.
PMID- 10679801
TI - Cyclophosphamide, etoposide, vincristine, adriamycin, and dexamethasone (CEVAD)
regimen in refractory multiple myeloma: an International Oncology Study Group
(IOSG) phase II protocol.
AB - A 4- day continuous intravenous (CIV) infusion of vincristine and doxorubicin
with high-dose dexamethasone (VAD) regimen is a standard refractory multiple
myeloma (MM) regimen. A Phase II study of a CEVAD regimen, i.e., VAD plus
etoposide administered as a 96-hr continuous infusion, was carried out with IV
bolus cyclophosphamide. Thirty-six patients were treated on study and received a
total of 114 cycles of CEVAD: median 2 cycles (range 1-8). No patient achieved a
CR. The overall rate of PR was 15/36 (42%). Patients achieved maximal response
after a median of 4 (range 3-6) courses. PR rates were 40% (4/10) in patients
with primary refractory disease, 48% (11/23) in patients with secondary
refractory disease, 31% (6/19) in patients who had failed previous VAD therapy,
and 50% (7/14) in patients receiving 2nd or subsequent relapse therapy. Three
patients died during their initial cycle of therapy from rapidly progressive
disease and sepsis. Overall median survival was 24 weeks with a 1-year survival
of 33.3% ?95% confidence interval of 20-46%?. Myelosuppression was the most
frequent adverse event with NCI grade 2 neutropenia and/or thrombocytopenia in
15% of first cycles, grade 3 in 20%, and grade 4 in 65%. Two-thirds of patients
had at least one episode of grade 3 or 4 sepsis. In 15% of septic episodes
positive blood cultures were obtained. Overt cardiotoxicity was seen in two
patients. CEVAD as used in this study was not more effective than VAD in terms of
overall response rate or survival.
PMID- 10679802
TI - Strong inverse correlation between serum TPO level and platelet count in
essential thrombocythemia.
AB - Serum thrombopoietin (TPO) levels in 50 essential thrombocythemia (ET) patients
were measured using a highly sensitive sandwich ELISA. In nine cases, TPO levels
were measured at two points with different platelet counts. ET patients showed
significantly higher serum TPO levels (n = 59, 2.70 +/- 2.74 fmol/mL, P < 0.0001)
than those of normal individuals (n = 29, 0.83 +/- 0.36 fmol/mL). Twenty-three
previously untreated ET patients also showed significantly higher serum TPO
levels (1.33 +/- 0.75 fmol/mL, P = 0.0066) than normal individuals. Extremely
high serum TPO levels (5.46 +/- 3.68 fmol/mL) were observed in ET patients with
normal platelet counts. Furthermore, a strong inverse correlation was found
between serum TPO levels and platelet counts in ET patients (R = -0.729, P < 0.
0001). This inverse correlation also held for each of nine cases with two-point
TPO measurements. In the clinical course of ET, megakaryocyte mass may parallel
the platelet mass before and after chemotherapy. Although it is unknown whether
overproduction of TPO exists or not in ET, total platelet and megakaryocyte mass,
i.e., the total number of c-Mpl, may play a role to regulate serum TPO levels.
PMID- 10679803
TI - Study on complex formation between recombinant human thrombomodulin fragment and
thrombin using surface plasmon resonance.
AB - Human thrombomodulin (hTM) is a newly described endothelial cell associated
protein that functions as a potent natural anticoagulant by converting thrombin
from a procoagulant protease to an anticoagulant. The affinity constant of
recombinant human soluble TM (rhs-TM) and a peptide containing active site of hTM
fragment (f-hTM) with thrombin were determined using the surface plasmon
resonance. The interaction of f-hTM with thrombin could be analyzed by a simple
model, whereas the association and the dissociation steps of rhs-TM with thrombin
consisted of at least two kinds of interaction phases. The dissociation constant
for complex (K(D)) of f-hTM and thrombin was determined to be 205 nM, which was
more than twice as high as that of rhs-TM (6.7 and 75 nM). The lower affinity of
f-hTM was not due to the slow association rate but to the rapid dissociation
rate. It comes clear that f-hTM interacts with thrombin rapidly.
PMID- 10679804
TI - Ticlopidine-induced aplastic anemia: development of chromosomal abnormalities and
response to immunosuppressive therapy.
AB - Severe aplastic anemia is a well-recognized complication of ticlopidine therapy
that carries a high mortality. Therapy with colony-stimulating factors or
corticosteroids has been largely ineffective in this disorder. We report a case
of ticlopidine-induced aplastic anemia that was successfully treated with
cyclosporine and high-dose dexamethasone. The patient rapidly responded to
immunosuppressive therapy and had a normal hemogram after cessation of
immunosuppression. On long-term follow-up, the patient developed a progressive
macrocytic anemia. Repeat bone marrow evaluation demonstrated myelodysplasia with
erythroid hypoplasia. An associated chromosomal abnormality consisting of a
t(3;16) (q21; p13.3) translocation was detected. This is the first report of a
chromosomal abnormality associated with ticlopidine induced marrow aplastic
anemia.
PMID- 10679805
TI - Antibody studies of factor VIII inhibitor in a case with Waldenstrom's
macroglobulinemia.
AB - We report a case of Waldenstrom's macroglobulinemia with prominent bleeding
tendency; laboratory investigation revealed an elevated activated partial
thromboplastin time. Further laboratory evaluation showed circulating factor VIII
anticoagulant, deemed polyclonal IgG, with a titer of 700 Bethesda Units/ml. The
factor VIII inactivation kinetics of the patient plasma were identical to those
of a type II inhibitor, and the inhibitor was found to recognize the A2 domain of
the factor VIII heavy chain. Apparently, paraprotein is not always the cause of
reduced activity of coagulation factors in neoplastic dysproteinemias.
PMID- 10679806
TI - Fibrinogen Longmont: a dysfibrinogenemia that causes prolonged clot-based test
results only when using an optical detection method.
AB - A new fibrinogen variant was discovered as a result of discrepancies found in
routine laboratory screening. The patient, a healthy 37-year-old woman, had a
mild bleeding history. Initial coagulation studies on the patient revealed a
prolonged prothrombin time (PT) and a normal activated partial thromboplastin
time (APTT). Further investigation on the patient and her mother demonstrated
both had a PT with no end point using an optical detection method (ACL3000+) and
a normal PT using an electromechanical detection method (ST4 Clot Detection
System). The APTT for both the patient and her mother were essentially normal
with both optical and mechanical detection methods. The patient and her mother
also had markedly prolonged thrombin time and reptilase time results on the
ACL3000+, but they were normal on the ST4. Coagulation test results on the
patient's father were all normal. We believe the fibrinogen defect in this family
may affect fibrin polymerization only enough to effect light scatter
interpretation, while there is enough polymerization to increase plasma viscosity
and yield an end point using an electromechanical analyzer. This report should
alert pathologists and clinicians to possible discrepancies between mechanical
and spectrophotometric clot testing methods.
PMID- 10679807
TI - The cost of treating immune thrombocytopenic purpura using intravenous Rh immune
globulin versus intravenous immune globulin.
AB - Multiple factors, including efficacy, toxicity and cost, may influence the
decision to treat immune thrombocytopenic purpura (ITP) with intravenous immune
globulin (IVIG) or intravenous Rho (D) immune globulin (IV RhIG). We conducted a
survey of 50 hospitals in 31 states to determine the costs for treating ITP using
conventional doses for IVIG or IV RhIG, based on package insert recommendations.
The average cost for a dose of IVIG ($2,771) was 71.7% ($1,157) more than that
for a dose of IV RhIG ($1,614). In the absence of clearly defined differences in
clinical outcomes when treating ITP with IVIG or IV RhIG, the difference in cost
may be an important factor in selecting the treatment.
PMID- 10679808
TI - Rapid detection of glucose-6-phosphate dehydrogenase type A-(202A/376G)
deficiency by allele-specific polymerase chain reaction.
PMID- 10679809
TI - Severe hemolytic anemia following high-dose intravenous immunoglobulin
administration in a patient with Kawasaki disease.
PMID- 10679810
TI - Philadelphia chromosome positive acute lymphocytic leukemia arising from aplastic
anemia.
PMID- 10679811
TI - Molecular characterization and chromosomal localization of mouse Puralpha gene.
AB - Puralpha is a 39-kDa sequence-specific single-stranded DNA/RNA binding protein
with the ability to modulate transcription of several genes containing the Pur
element in their promoter region. Human and mouse Puralpha exhibit an
extraordinary degree of conservation with only two changes at amino acid residues
49 and 306. A 15-kb genomic clone encompassing the mouse Puralpha gene was
isolated by screening the mouse genomic library, using a PCR-amplified fragment
from human Puralpha cDNA. Results from sequencing analysis confirmed the isolated
genomic clone to be Puralpha and not the other members of the Pur family,
including Purbeta. Characterization of the mouse Puralpha gene by restriction
analysis/Southern blotting and sequencing revealed that the Puralpha gene
contains only one intron within the 5' UTR and the open reading frame was intact.
Using chromosomal markers, the Puralpha gene was mapped to chromosome 18 in mouse
and rat.
PMID- 10679812
TI - Induction of apoptosis in HL-60 cells by N(6)-benzyladenosine.
AB - Treatment of HL-60 cells with micromolar concentrations of N(6)-benzyladenosine
(N(6)-benzylaminopurine riboside [BAPR]) led to the occurrence of apoptosis in a
concentration-dependent manner. Incubation period as short as 2 h in the presence
of BAPR was sufficient for triggering irreversible changes leading to apoptosis
even after the transfer of cells to the standard medium (without BAPR). Cell
death induced by BAPR proceeded rapidly and in a very synchronous fashion.
Detailed study of temporal changes in a chromatin structure and DNA integrity
showed that the movement of chromatin toward the nuclear periphery is the
fundamental event within dying cells. We demonstrated that this rearrangement of
chromatin is irreversible and it takes place without apparent DNA degradation.
The extensive DNA cleavage seems to be a rather late event, as it was observed in
cells that exhibited a typical apoptotic morphology (apoptotic bodies). On the
basis of temporal changes in the ATP level within dying cells, it is concluded
that ATP is essential for the movement of chromatin toward the nuclear envelope
but not for the subsequent chromatin condensation leading to the formation of
apoptotic bodies. DNA fragmentation also seems to be ATP independent. BAPR
interfered with neither pyrimidine nor purine biosynthesis, as none of the tested
bases and the corresponding nucleosides prevented or reduced apoptosis in BAPR
treated cells. Adenosine was the only exception that substantially reduced the
effect of BAPR. Since transport of exogenous adenosine into cells was essential
to manifest its protective effect, we assume that adenosine is a competitive
inhibitor of adenosine kinase and thus reduces intracellular phosphorylation of
BAPR. Indeed, 4-amino-3-iodo-1(beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine, a
potent inhibitor of adenosine kinase, fully prevented BAPR-induced apoptosis.
These results suggest that cytotoxic effect of BAPR is related to its activation
by phosphorylation within cells, rather than to its interaction with
extracellular adenosine receptors.
PMID- 10679813
TI - Dietary regulation and localization of apoptosis cascade proteins in the colonic
crypt.
AB - This study was designed primarily to assess the localization of apoptosis cascade
proteins along the rat colonic crypt and secondarily to test whether the activity
and/or localization of these proteins are affected by the enrichment of the diet
with the soluble fiber pectin. Expression of apoptosis cascade proteins was
assessed in isolated colonocytes harvested from the luminal and basal crypt
colonocyte populations. Two different dietary regimens were tested: a standard
diet (diet A), and a diet enriched in pectin (diet B), a soluble fiber that
undergoes fermentation in the cecum and produces high concentrations of
intracolonic short-chain fatty acids. Caspase-1 expression was maximal in luminal
colonocytes of rats fed diet B, as evidenced by Western blot and
immunohistological analyses. Expression of the cleaved poly(ADP-ribose)
polymerase product was elevated in both the luminal and basal colonocytes of the
pectin-fed group, whereas in rats fed diet A, the expression was lower,
especially in basal crypt colonocytes. The highest expression of the
antiapoptotic protein Bcl-2 was observed in the lower compartments of the colonic
crypt tissue and was maximal in the rat group fed a standard diet. The apoptotic
index in colonocytes of rats fed diet B was higher than that measured in rats fed
diet A. Cumulatively, our results indicate that apoptosis cascade proteins are
differentially localized along the lumen-crypt axis, and their expression and
activity may be controlled by dietary components. These results may, at least
partially, account for the documented protective effect of butyrogenic fibers on
colorectal cancer.
PMID- 10679814
TI - Modified intranuclear organization of regulatory factors in human acute
leukemias: reversal after treatment.
AB - Acute leukemias arise secondary to chromosomal aberrations that cause
dysfunctions in gene regulation and regulatory factors. Significant differences
in morphology between acute leukemic and nonleukemic hematopoietic cells are
readily observed. How morphologic changes of the nuclei of acute leukemic cells
relate to the underlying functional alterations of gene expression is minimally
understood. Spatial modifications in the representation and/or organization of
regulatory factors may be functionally linked to perturbations of gene expression
in acute leukemic cells. Using in situ immunofluorescence microscopy, we
addressed the interrelationships of modifications in nuclear morphology with the
intranuclear distribution of leukemia-related regulatory factors (including ALL
1, PML, and AF-9) in cells from patients with acute leukemia. We compared the
localization of leukemia-associated proteins with various factors involved in
gene transcription and RNA processing (e.g., RNA polymerase II and SC-35). Our
findings suggest that there are leukemia-associated aberrations in mechanisms
that direct regulatory factors to sites within the nucleus. This misplacement of
key cognate factors may contribute to perturbations in gene expression
characteristic of leukemias.
PMID- 10679815
TI - Stimulant-free preculture in heterologous serum-supplemented medium induces
unresponsiveness of T cells to subsequent mitogenic stimulation.
AB - Quite often freshly isolated lymphocytes are kept in culture before
experimentation for 1 or more days without any stimulus. Most of the time,
culture is supplemented with fetal bovine serum (FBS) which is heterologous to
all species except bovine. In the present study, we found that freshly isolated
murine T cells show a good proliferative response to concanavalin A (Con A) and
phorbol ester (PMA)/ionomycin in FBS medium, without any detectable background
proliferation. However, the cells kept in the same culture without any stimulus
for prolonged period of time (referred to as preculture in this report) showed
reduced response to Con A and PMA/ionomycin in a time-dependent manner. Almost a
complete loss of response to Con A was observed within 1 day of preculture.
However, loss of response to PMA/ionomycin was observed only after 2 days of
preculture. Interestingly, similar preculture in autologous mouse serum
supplemented media did not cause any loss of the response to these mitogens. The
loss of responsiveness of T cells during preculture in heterologous serum was
irreversible. The heterologous serum-induced unresponsiveness of T cells to these
mitogens was also prevented by adding Calphostin C, a specific protein kinase C
(PKC) inhibitor, during preculture in heterologous serum. These results showed
that prolonged stimulant-free preculture in heterologous serum induces
irreversible unresponsiveness of T cells to mitogens through the down regulation
of T cell receptor signaling pathway, which can be prevented by autologous serum
or a PKC inhibitor.
PMID- 10679816
TI - Transcriptional control elements and complex initiation pattern of the TATA-less
bidirectional human thymidylate synthase promoter.
AB - The nucleotide sequences that are important for transcription of the human
thymidylate synthase gene were analyzed by deletion and site-directed mutagenesis
of the promoter region. Deletion analyses from the 5' and 3' ends indicated the
presence of multiple positive and negative elements. The promoter had
approximately the same strength in the normal or inverted orientation. The region
between 161 and 141 nt upstream of the translational start codon was found to be
both necessary and sufficient for high-level promoter activity in both directions
and was designated the essential promoter region. This region, which is highly
conserved in human, mouse and rat TS promoters, contains potential binding sites
for Ets, Sp1, and LSF transcription factors. Site directed mutagenesis of each of
these elements led to large decreases in promoter strength. However, inactivation
of potential Sp1 and E2F elements adjacent to the essential promoter region led
to increases in promoter strength. The transcriptional start site pattern was
analyzed by S1 nuclease protection assays of mRNA isolated from cells transiently
transfected with TS minigenes. Multiple start sites were detected, most of which
were between 160 and 120 nt upstream of the AUG codon.
PMID- 10679817
TI - Interaction of HIV-1 Tat with Puralpha in nuclei of human glial cells:
characterization of RNA-mediated protein-protein binding.
AB - A complex between the Tat protein, encoded by human immunodeficiency virus type 1
(HIV-1), and the cellular protein, Puralpha, has been implicated in activation of
the late promoter of JC virus (JCV) and in enhancement of JCV DNA replication.
JCV is the causative agent of progressive multifocal leukoencephalopathy (PML),
an acquired immunodeficiency syndrome (AIDS) opportunistic infection of the
brain. Puralpha also binds the HIV-1 TAR RNA element and activates HIV-1
transcription, suggesting a role for RNA binding in the action of this protein.
Using immunoelectron microscopy, we find that in human glial cells expressing
both proteins, Tat and Puralpha are colocalized in extranucleolar chromatin
structural elements. The colocalized Puralpha and Tat are nearly exclusively
nuclear, although individual proteins can be seen in both nucleus and cytoplasm,
suggesting a preferential tropism of the complex for the nucleus. Analysis of the
interaction between purified proteins indicates that the Tat-Puralpha interaction
is strongly enhanced by the presence of RNA. Tat amino acids from 37-48 are
essential for Tat binding. Residues 49-72, including the TAR RNA-binding domain,
are critical for binding to Puralpha, while Cys(22), in the Tat transactivation
domain, is responsible for an important global effect. Puralpha repeat II domains
are involved in the interaction, and a polypeptide based on one such sequence
inhibits binding. After RNase treatment of Puralpha enhancement of Tat binding
can be partially restored by addition of a single-stranded JCV DNA PUR element,
to which Tat does not bind. The results indicate that the Tat-Puralpha
interaction is direct, rather than through an RNA link, and that RNA binding
configures Puralpha for optimal interaction with Tat.
PMID- 10679818
TI - Cyclin C is a primary 1alpha,25-dihydroxyvitamin D(3) responding gene.
AB - 1alpha,25-dihydroxyvitamin D(3) (VD) is a pleiotropic nuclear hormone that also
has effects on cell cycle regulation. VD and its synthetic analogues are known
inhibitors of cellular growth and inducers of apoptosis, however, the primary
mediator genes of these effects largely remain unknown. In order to identify
novel targets for VD, that may be involved in the regulation of the cell cycle, a
differential display PCR (ddPCR) approach was applied to the MCF-7 human breast
cancer cell line, which provided the gene for cyclin C as an interesting
candidate. Quantitative assessment of cyclin C expression showed that the gene
was significantly upregulated by VD and its analogues, EB1089 and CB1093 both on
the level of mRNA expression and more so on the level of protein expression in
MCF-7 cells. Upregulation of cyclin C protein expression could also be confirmed
in MeWo human melanoma and in U937 human promyelocytic leukemia cells. This
observation adds a new gene candidate to the list of primary VD responding genes.
Cyclin C is not a typical cyclin, as it apparently modulates the activity of the
RNA polymerase II complex, which provides fresh insight into the mechanisms of
cell cycle and general transcriptional regulation by VD and its analogues.
PMID- 10679819
TI - Multiple low-dose and single high-dose treatments with streptozotocin do not
generate nitric oxide.
AB - Streptozotocin (STZ) is a widely used diabetogenic agent that damages pancreatic
islet beta cells by activating immune mechanisms, when given in multiple low
doses, and by alkylating DNA, when given at a single high dose. Actually, STZ
contains a nitroso moiety. Incubation of rat islets with this compound has been
found to generate nitrite; moreover, photoinduced NO production from STZ has been
demonstrated. These reports have suggested that direct NO generation may be a
mechanism for STZ toxicity in diabetogenesis. Several other studies have denied
such a mechanism of action. This study has shown that (1) the multiple low-dose
(MLDS) treatment does not stimulate NO production at the islet level; in fact,
nitrite + nitrate levels and aconitase activity (also in the presence of an NO
synthase inhibitor, namely NAME) remain unmodified; RT-PCR analysis demonstrates
that this treatment does not stimulate iNOS activity; (2) the high-dose (HDS)
treatment does not stimulate NO production; in fact nitrite + nitrate levels
remain unmodified and iNOS mRNA levels are not altered, although aconitase
activity is significantly decreased. Moreover, we have confirmed that the MLDS
treatment is able to decrease SOD activity by day 11 and that STZ, given in a
single high dose, transiently increases superoxide dismutase (SOD) values (24 h
from the administration), then dramatically lowers SOD levels. On the basis of
our results, we conclude that STZ, "in vivo" is unable to generate NO, both as a
MLDS or HDS treatment, thus excluding that NO exerts a role in streptozotocin
dependent diabetes mellitus.
PMID- 10679820
TI - Isolation and characterization of the chicken vitamin D receptor gene and its
promoter.
AB - The sequences from several independent cDNA clones encoding the chicken vitamin D
receptor as well as primer extension assay have clearly delineated the 5'
terminus and the transcriptional start site. Screening a chicken genomic library
produced genomic clones containing vitamin D receptor (VDR) gene fragments.
Restriction map of clone 8 showed that the 18.6-kb chicken VDR fragment has exons
1 and 2, intron 1, part of intron 2, and 7-kb 5' flanking region. Exons 1, 2, and
3 found in the chicken VDR gene shares low homology with its mammalian
counterparts (i.e., E1A, E1B, and E1C in human). By contrast, the fourth exon and
following exons for the coding region of VDR gene are highly conserved between
avian and mammalian species. While the fourth exon bears the ATG sites for
translation initiation in mammals, the third exon in birds has two extra ATG
sites for leaky translation as determined previously. Thus, the avian VDR has
more N-terminal sequence than the mammalian VDR and is found in two distinct
forms. The 5' flanking region from genomic clone 8 shares considerable homology
in several regions with the human and mouse VDR promoters. Moreover, the 5'
flanking region of chicken VDR gene possesses promoter activity, as shown by its
ability to drive the luciferase reporter gene in cell transfection assays. Like
other steroid receptor promoters, the chicken VDR promoter contains no TATA box
but possesses several GC boxes or SP1 sites. A series of deletional promoter
constructs established that the proximal GC boxes are the major drivers of gene
transcription, while the more upstream sequences have repressive elements.
PMID- 10679821
TI - Cloning the full-length cDNA for rat connective tissue growth factor:
implications for skeletal development.
AB - The mammalian osteopetroses represent a pathogenetically diverse group of
skeletal disorders characterized by excess bone mass resulting from reduced
osteoclastic bone resorption. Abnormalities involving osteoblast function and
skeletal development have also been reported in many forms of the disease. In
this study, we used the rat mutation, osteopetrosis (op), to examine differences
in skeletal gene expression between op mutants and their normal littermates. RNA
isolated from calvaria and long bones was used as a template for mRNA
differential display. Sequence information for one of the many cDNA that were
selectively expressed in either normal or mutant bone suggested that it is the
rat homologue of connective tissue growth factor (CTGF) previously cloned in the
human, mouse, and other species. A consensus sequence was assembled from
overlapping 5'-RACE clones and used to confirm the rat CTGF cDNA protein coding
region. Northern blot analysis confirmed that this message was highly (8- to 10
fold) over-expressed in op versus normal bone; it was also upregulated in op
kidney but none of the other tissues (brain, liver, spleen, thymus) examined. In
primary rat osteoblast cultures, the CTGF message exhibits a temporal pattern of
expression dependent on their state of differentiation. Furthermore, CTGF
expression is regulated by prostaglandin E(2), a factor known to modulate
osteoblast differentiation. Since members of the CTGF family regulate the
expression of specific genes, such as collagen and fibronectin, we propose that
CTGF may play a previously unreported role in normal skeletal
modeling/remodeling. Its dramatic over-expression in the op mutant skeleton may
be secondary to the uncoupling of bone resorption and bone formation resulting in
dysregulation of osteoblast gene expression and function.
PMID- 10679822
TI - A deficit in collagenase activity contributes to impaired migration of aged
microvascular endothelial cells.
AB - Angiogenesis is impaired in aging. Delayed neovascularization is due, in part, to
slowed endothelial cell migration. Migration requires an optimal level of
adhesion to matrix proteins, a process mediated by matrix-degrading
metalloproteases (MMPs) such as MMP1. To determine whether impaired angiogenesis
in aging is associated with altered synthesis and activity of MMP1, we examined
the expression of collagenase and tissue inhibitor of metalloprotease 1 (TIMP1)
by immunostain of angiogenic sponge implants from young and aged mice. To
characterize the relevance of MMP activity during the movement of aged
endothelial cells, the secretion of MMP1 and TIMP1 by late-passage human
microvascular endothelial cells (hmEC aged in vitro) and their non-aged (young)
counterparts was quantified. The migration of aged human microvascular
endothelial cells and the effect of inhibition of TIMP1 on the migration of aged
hmEC or collagen I was also measured. Relative to young mice, granulation tissue
from aged mice showed less expression of collagenase and increased expression of
TIMP1. In vitro, aged hmEC were deficient in MMP1 secretion (55 +/- 13% relative
to young cells) and activity but showed increased expression of TIMP1 (280 +/-
109% relative to young cells). Aged hmEC migrated significantly less distance
than did young hmEC over a 5-day period (59 +/- 8% relative to young cells). In
the presence of a blocking antibody to TIMP1, aged hmEC showed a significant
increase in the distance migrated on collagen I over a 5 day period (142 +/- 11%
relative to untreated aged hmEC). We propose that deficient MMP1 activity
contributes to impaired cellular movement in aged microvascular endothelial cells
and that perturbations that enhance collagenase activity increase their migratory
ability and angiogenic potential.
PMID- 10679823
TI - Regulation of heat shock protein message in Jurkat cells cultured under serum
starved and gravity-altered conditions.
AB - Although our understanding of effects of space flight on human physiology has
advanced significantly over the past four decades, the potential contribution of
stress at the cellular and gene regulation level is not characterized. The
objective of this ground-based study was to evaluate stress gene regulation in
cells exposed to altered gravity and environmentally suboptimal conditions. We
designed primers to detect message for both the constitutive and inducible forms
of the heat shock protein, HSP-70. Applying the reverse transcriptase-polymerase
chain reaction (RT-PCR), we probed for HSP-70 message in human acute T-cell
leukemia cells, Jurkat, subjected to three types of environmental stressors: (1)
altered gravity achieved by centrifugation (hypergravity) and randomization of
the gravity vector in rotating bioreactors, (2) serum starvation by culture in
medium containing 0.05% serum, and (3) temperature elevation (42 degrees C).
Temperature elevation, as the positive control, significantly increased HSP-70
message, while centrifugation and culture in rotating bioreactors did not
upregulate heat shock gene expression. We found a fourfold increase in heat shock
message in serum-starved cells. Message for the housekeeping genes, actin and
cyclophilin, were constant and comparable to unstressed controls for all
treatments. We conclude that gravitational perturbations incurred by centrifugal
forces, exceeding those characteristic of a Space Shuttle launch (3g), and
culture in rotating bioreactors do not upregulate HSP-70 gene expression. In
addition, we found RT-PCR useful for evaluating stress in cultured cells.
PMID- 10679824
TI - Transgenic mice with a mutated collagen promoter display normal response during
bleomycin-induced fibrosis and possess neurological abnormalities.
AB - We have previously identified a potential TGF-beta activation element (TAE) in
the rat collagen alpha1(I) promoter at -1624 upstream of the transcriptional
start site [Ritzenthaler et al., 1991, 1993]. To determine the importance of the
TAE in vivo, we produced transgenic mice carrying 3.6 kb of the rat collagen
alpha1(I) promoter linked to the reporter gene chloramphenicol acetyl transferase
with and without site-directed mutations that eliminate DNA-protein binding at
the TAE site. Tissue-specific expression of the reporter gene in transgenic mice
with the mutated collagen promoter was similar to that of transgenic mice with
the normal promoter in two genetic backgrounds as judged by in situ
hybridization, reporter assays, and immunochemistry. Endotracheal instillation of
bleomycin induces lung fibrosis, mediated in part by TGF-beta. Earlier studies
indicated that expression of wild-type collagen-reporter gene was upregulated in
transgenic mice lungs in response to endotracheal instillation of bleomycin. A
similar level of reporter gene upregulation was observed in transgenic mice
carrying the mutation in the TAE. Two lines of transgenic mice carrying the
mutated promoter construct displayed unexpected neurological abnormalities. In
the FVB genetic background, there was a higher than normal incidence of
mortality, spontaneous seizures, and an inability to nurture offspring.
Histological evidence demonstrated clear abnormalities, including disorderly
arrangement of neurons in the hippocampus and significant laminar cortical
necrosis in the cerebrum in animals after seizures. In the C57Bl/6 background,
there was a high incidence of severe communicating hydrocephalus, early runting,
and increased mortality similar to that in transgenic animals with astroglial
overexpression of TGF-beta. These animals provide an interesting model system to
investigate molecular mechanisms responsible for seizures and hydrocephalus.
PMID- 10679825
TI - Parathyroid hormone inhibits collagen synthesis and the activity of rat col1a1
transgenes mainly by a cAMP-mediated pathway in mouse calvariae.
AB - We examined the effect of parathyroid hormone and various signaling molecules on
collagen synthesis and chloramphenicol acetyltransferase activity in cultured
transgenic mouse calvariae carrying fusion genes of the rat Col1a1 promoter and
the chloramphenicol acetyltransferase reporter. After 48 h of culture,
parathyroid hormone, forskolin, dibutyryl cAMP, 8-bromo cAMP, and phorbol
myristate acetate inhibited transgene activity, while the calcium ionophore
ionomycin had no effect. Pretreatment of calvariae with the phosphodiesterase
inhibitor isobutylmethylxanthine potentiated the inhibitory effect of 1 nM
parathyroid hormone on transgene activity and collagen synthesis. Parathyroid
hormone further inhibited transgene activity and collagen synthesis in the
presence of phorbol myristate acetate. Parathyroid hormone inhibition of
transgene activity and collagen synthesis was not affected by indomethacin or
interleukin-6. After 48 h of culture, parathyroid hormone inhibited
chloramphenicol acetyltransferase activity by 50-85% in cultured calvariae
carrying transgenes having progressive 5' upstream deletions of promoter DNA down
to -1683 bp. These data show that the inhibitory effect of parathyroid hormone on
Col1a1 expression in mouse calvariae is mediated mainly by the cAMP signaling
pathway. Prostaglandins and IL-6 are not local mediators of the parathyroid
hormone response in this model. Finally, regions of the Col1a1 promoter
downstream of -1683 bp are sufficient for parathyroid hormone inhibition of the
Col1a1 promoter.
PMID- 10679826
TI - Expression and regulation of the cGMP-binding, cGMP-specific phosphodiesterase
(PDE5) in human colonic epithelial cells: role in the induction of cellular
refractoriness to the heat-stable enterotoxin peptide.
AB - Stable toxin (ST) peptides are the causative agents for a severe form of watery
diarrhea. These peptides bind to a membrane-associated form of guanylyl cyclase,
guanylyl cyclase C. The result is an accumulation of cyclic guanosine
monophosphate (cGMP) in the intestinal cell, regulating protein kinase activity
and the phosphorylation of a number of proteins involved in ion transport across
the intestine. Using the human T84 colonic cell line as a model system, we show
that cGMP accumulation in these cells after ST application is regulated by the
activity of the cGMP-binding, cGMP-specific phosphodiesterase (PDE5). The
presence of human PDE5 in this cell line was confirmed by Western blot analysis,
using an antibody raised to the bovine enzyme, and by the observation that cGMP
hydrolytic activity detected in T84 cell lysates was almost completely inhibited
by low concentrations of zaprinast, a specific inhibitor of PDE5. An increase in
activity of PDE5 was observed in T84 cell lysates on exposure to the ST peptide
and prolonged exposure of T84 cells to the ST peptide led to the induction of
cellular refractoriness in these cells, which was largely contributed in terms of
an increased rate of degradation of cGMP in desensitized cells as a result of
PDE5 activation. This activation was correlated with an increase in the affinity
of the enzyme for the substrate cGMP, as well as an increased affinity for
zaprinast. We provide evidence for the first time that cGMP levels in the human
colonocyte are regulated by the cGMP-hydrolytic activity of PDE5 and suggest that
the expression and regulation of PDE5 in the intestine could therefore be
important in controlling cGMP-mediated signaling in this tissue.
PMID- 10679827
TI - Keeping score.
PMID- 10679828
TI - Standardisation of ambulatory urodynamic monitoring: Report of the
Standardisation Sub-Committee of the International Continence Society for
Ambulatory Urodynamic Studies.
PMID- 10679829
TI - A simplified urinary incontinence score for the evaluation of treatment outcomes.
AB - There are no standardized definitions for anti-incontinence therapy outcomes. The
present study was conducted to evaluate whether the incorporation of several non
invasive outcome measures into a new score may serve as a meaningful outcome
instrument. Ninety-four consecutive sphincteric incontinent women who underwent a
pubovaginal sling by a single surgeon were enrolled. All patients underwent a
full clinical evaluation, including pre- and post-operative questionnaires, 24
hour voiding diary, and 24-hour pad test. Surgery outcomes were classified twice:
First, by analyzing the patient questionnaire, voiding diary, and pad test
separately, according to previously published criteria, and second, by combining
the three outcome tools into a new response score. The new score was constructed
in a simple, easy-to-remember format and divided into five categories: cure, good
response, fair response, poor response, and failure. All patients were evaluated
at least 1 year post-operatively. Comparison of the old and new classifications
suggests that the new response score provides a more accurate evaluation of the
surgical outcomes. Although 64 to 69% of the patients were originally classified
as cure according to the old classification, only 44.7% were re-classified as
cure by the strict criteria employed in the new score. Furthermore, the response
score also differentiates between various degrees of clinical improvement (i.e.,
good, fair, or poor response). Twenty-five (26.6%) patients, most of whom were
previously classified as cure, were re-classified as good response, whereas 20
others were re-classified as fair (13. 9%), or poor (7.4%) response. Seven (7.4%)
patients were re-classified as surgical failures. All were diagnosed pre
operatively as having complex sphincteric incontinence. Specific failure rates
were therefore 11.3% for complex and 0% for simple cases. In conclusion, the
suggested post-operative response score incorporates in a user-friendly format
three popular outcome tools (i.e., 24-hour diary, 24-hour pad test, and patient
questionnaire) and seems to reflect the surgical results more accurately. Further
studies are needed to assess its validity and reproducibility in other treatment
modalities. Neurourol Urodynam. 19:127-135, 2000.
PMID- 10679830
TI - A severity index for epidemiological surveys of female urinary incontinence:
comparison with 48-hour pad-weighing tests.
AB - In epidemiological surveys of female urinary incontinence, it is not feasible to
demonstrate urine loss objectively. The aim of this study was to develop a valid
epidemiological instrument (a severity index) for assessing the severity of
incontinence. The severity index is based on information about frequency (four
levels) and amount of leakage (two or three levels). By multiplication, an index
value (1-8 or 1-12) is reached. This index value is further categorized into a
severity index of three or four levels. The index was compared with the results
of 315 pad-weighing tests performed by 265 women in hospital and general
practice. Data from an epidemiological survey were also re-analyzed by applying
the four-level severity index. Mean pad-weighing results (grams per 24 hours, 95%
confidence interval) for the three-level severity index was slight (6; 2-9),
moderate (17; 13-22), and severe (56; 44-67). For the four-level severity index,
the results were slight (6; 2-9), moderate (23; 15-30), severe (52; 38-65), and
very severe (122; 84-159). Spearman's correlation coefficient for pad-weighing
results and the three-level severity index was 0.47 (P < 0.01) and for the four
level severity index 0.54 (P< 0.01). The four-level severity index gave a more
balanced distribution among the women in the clinical materials, and data from
the epidemiological survey showed that the four-level severity index identifies a
sub-group of older women with very severe incontinence. The four-level severity
index seems to be a valid representation of incontinence severity as measured by
pad-weighing tests in women presenting for clinical care. It should be considered
a potentially valid measure of incontinence severity in epidemiological studies.
Neurourol. Urodynam. 19:137-145, 2000.
PMID- 10679831
TI - Effects of menstrual cycle and urinary tract instrumentation on uroflowmetry.
AB - We sought to compare bladder emptying function in normal women during the
proliferative and secretory phases of the menstrual cycle and to evaluate whether
urethral catheterization affected uroflowmetry parameters. Forty-nine normal
volunteers (ages 19-42 years) were recruited and underwent uroflowmetry in the
proliferative and secretory phases of the menstrual cycle. A serum progesterone
level of <3.0 ng/mL defined the proliferative phase. During the proliferative
phase, volunteers underwent uroflowmetry analysis when a sensation of fullness
was appreciated. A post-void residual volume was determined, and the bladder was
filled with 400 mL of normal saline. Repeat uroflowmetry analysis was then
performed. This two-step procedure was repeated at a separate visit during the
secretory phase. Voided volume, residual volume, maximum and average flow rates,
time-to-maximum flow, and duration of flow were recorded. Wilcoxon signed-rank
tests were used for statistical analysis. A two-tailed alpha value of <0.05
defined statistical significance. Our analysis was limited to the 33 patients
whose predicted menstrual dating correlated with the obtained progesterone
levels. During the follicular phase, we found significantly faster maximum (P <
0.0001) and average flow rates (P = 0.01), along with a shorter time-to-maximum
flow (P < 0.0001) and shorter duration of flow (P < 0.0001), during the pre
catheterized void than the post-catheterized void. Similar results were observed
in the secretory phase with the exception of a slightly higher residual volume (P
= 0.05). No difference was seen in any measured uroflowmetry parameter when
comparing similar voids between phases of the menstrual cycle. We conclude that
when evaluating pre-menopausal patients, uroflowmetry may be scheduled and
performed during either phase of the menstrual cycle. Neurourol. Urodynam. 19:147
152.
PMID- 10679832
TI - A mathematical micturition model to restore simple flow recordings in healthy and
symptomatic individuals and enhance uroflow interpretation.
AB - We describe a model and report a new method to extract quantified data from the
simple analysis of whole uroflow curves in healthy and symptomatic individuals.
Recorded flow curves were compared with the curves theoretically predicted from a
mathematical micturition model. This model was developed by relating each
physiological event occurring during micturition to a set of mathematical
equations. Due to improvements in speed of computer calculations, a very fast and
adaptable mathematical micturition model became available. A total of 302 uroflow
curves from 142 patients (61 men and 81 women) were studied. The control group
consisted of seven men and 25 women; the symptomatic groups comprised 54 men and
56 women. The mathematical model was applied to analyze all the recorded curves.
For patients with lower urinary tract symptoms, specific modelization parameters
were introduced according to the clinical condition to be tested. Using two
compulsory (patient sex and voided volume) and two optional parameters (clinical
condition and urethral catheter size), our mathematical model was able to produce
uroflow calculated curves similar to observed curves. In the control group, the
calculated and recorded uroflow curves were found to superimpose with an
impressive accuracy, i.e., a quadratic error <1%. Test-re-test studies gave the
same determination of the specific parameters. In benign prostatic hyperplasia
patients, the compressive effect on both prostatic urethra and bladder neck was
separately identified. The same intra-individual values were found at 2-week
intervals in the group with no treatment (P = no significance), whereas after 3
months of treatment with an alpha-blocker, a decrease in values was noted in
responder patients (P < 0.001). In women with various degrees of cystocele, a
constrictive effect was identified and found to be identical for successive flows
during the same urodynamic testing. This large prospective study demonstrated the
relevance of a sophisticated, heavily computerized micturition model, taking into
account physiological voiding parameters, to the study of flow in healthy
individuals and patients with benign prostatic hyperplasia or cystocele. Curve
fitting led to the determination of critical events during flow such as break
point and plateau phase. Determination of these events may enhance uroflow
interpretation by providing additional information on the detrusor function.
Neurourol. Urodynam. 19:153-176, 2000.
PMID- 10679833
TI - Editorial comment.
PMID- 10679834
TI - Voiding pattern in healthy newborns.
AB - A 4-hour observation period has been used in infants to investigate suspected
bladder dysfunction. The aim of the present study was to extend the usefulness of
this protocol by establishing reference values for voiding frequency, intervals,
volumes, and residual urine in healthy newborns. The study included 51 healthy
newborns, 26 girls and 25 boys, aged 3 to 14 days. During a 4-hour period, all
micturitions and residuals were recorded as well as feeding, sleeping, crying,
and defecations. The observation was completed with the child undressed to
observe the urinary stream during one void. Different provocation tests were
tried to induce urinary leakage. All newborns voided with a stream, about once
per hour, with a median volume of 23 mL. For each voiding parameter, there was a
large inter- and intra-individual variability. Double voidings were common as
well as sizable residual volumes. The diuresis was about six times higher than in
healthy school children. The healthy newborns did not leak during provocation
tests such as manual compression of the bladder. Neurourol. Urodynam. 19:177-184,
2000.
PMID- 10679835
TI - The distribution of vesicular acetylcholine transporter in the human male
genitourinary organs and its co-localization with neuropeptide Y and nitric oxide
synthase.
AB - Because doubt still remains concerning the distribution of nerves that are
unequivocally cholinergic in the human genitourinary organs, we have used a
specific marker, namely, an antibody to vesicular acetylcholine transporter
(VAChT), to immunolabel cholinergic axons and cell bodies in specimens of urinary
bladder, seminal vesicle, vas deferens, and prostate gland obtained from neonates
and children post mortem. In addition some sections were double-immunolabeled
with VAChT and either neuropeptide Y (NPY) or nitric oxide synthase (NOS). The
results demonstrated a rich cholinergic innervation to the muscle coat of the
bladder body with a much less prominent, but nonetheless significant, cholinergic
innervation to the smooth muscle components of the seminal vesicle, vas deferens,
and prostate. Small ganglia were scattered throughout the detrusor muscle of the
urinary bladder, approximately 75% of the intramural neurons being VAChT
immunoreactive, whereas approximately 95% contained NPY and approximately 40%
contained NOS. VAChT immunoreactivity was observed in 40% of neurons in ganglia
scattered throughout the pelvic plexus. Almost all these cholinergic neurons
contained NPY and approximately 65% contained NOS. Almost all the cholinergic
nerve fibers throughout the genitourinary organs also contained NPY. Although NOS
was sparse in the cholinergic nerves of the bladder body, it occurred in the
majority of cholinergic nerves at the bladder neck and was also present in a
proportion of the cholinergic nerves in the other organs examined. VAChT
immunoreactive nerves were also observed in a sub-epithelial location in all the
organs examined, the majority containing NPY, whereas a small proportion
contained NOS. Although doubt remains about the function of sub-epithelial
cholinergic nerves in the urinary bladder, the majority of similar nerves in the
seminal vesicle, vas deferens, and prostate gland are considered to be
secretomotor. Collectively these findings demonstrate that the cholinergic
innervation of the male genitourinary system is well established in the neonate
and child. Neurourol. Urodynam. 19:185-194, 2000.
PMID- 10679836
TI - Acute increase in blood flow to the rat bladder subsequent to partial bladder
outlet obstruction.
AB - Partial obstruction of the rat bladder outlet initiates a multi-step process
during which the bladder progressively loses its functional ability. The first
step in this progression is bladder hypertrophy; the organ dramatically increases
in size and weight to compensate for the effects of obstruction. Unoperated
female rats, age-matched, sham-obstructed rats, and rats that received a partial
bladder outlet obstruction were studied. During the first 24 hours after partial
bladder outlet obstruction, relative bladder blood flow was measured using a
fluorescent microsphere infusion technique and laser Doppler imaging. Nitric
oxide synthase (NOS) activities of control and obstructed rat bladder tissues
were determined using an enzymatic assay that measures the conversion of (3)H-L
arginine to (3)H-L-citrulline. Using the microsphere infusion technique, a
significant increase in blood flow to the obstructed rat bladder was observed
during the first 24 hours after partial bladder outlet obstruction. Relative
bladder blood flow increased approximately sixfold at 4 and 6 hours post
obstruction and remained elevated through 24 hours of obstruction. Sham
operations (evaluated after 6 hours after surgery) resulted in a minor increase
in blood flow that did not reach statistical significance. Relative blood flow to
the spleen, measured in the same rats, was not significantly changed. Laser
Doppler measurements also identified a significant increase in rat bladder blood
flow after outlet obstruction and showed that increased blood flow could be
detected as early as 1 hour post-obstruction. Interestingly, despite the
significant differences in bladder blood flow between control and early post
obstructed rat bladders, NOS activities of control and obstructed rat bladders
were comparable. The increase in bladder blood flow precedes the urothelial,
fibroblast and smooth muscle cell hyperplasia, and the smooth muscle hypertrophy
that occurs after obstruction. We propose that, in response to surgical induction
of partial outlet obstruction, acute up-regulation of bladder blood flow may be
an initiating factor for subsequent bladder cell proliferation and smooth muscle
hypertrophy. Neurourol. Urodynam. 19:195-208, 2000.
PMID- 10679837
TI - Editorial comment.
PMID- 10679838
TI - Authors' reply.
PMID- 10679839
TI - Stress urinary incontinence: prevalence among nulliparous compared with
primiparous and grand multiparous pre-menopausal women.
PMID- 10679840
TI - Delusions and hallucinations in Alzheimer's disease: prevalence and clinical
correlates.
AB - OBJECTIVES: The purpose of this study was to examine the frequency of delusions
and hallucinations in patients with Alzheimer's disease (AD) and to investigate
factors associated with each or the combination of the two. DESIGN: This was a
cross-sectional, case-control study. SETTING: Neuropsychiatry and Memory Group,
The Johns Hopkins University, USA. PARTICIPANTS: Three hundred and forty-two
community-residing patients with probable AD according to NINCDS/ADRDA criteria
were included in the study. MEASURES: Patients were assessed clinically for the
presence of psychotic symptoms using the DSM-IV glossary definitions. The
patients were also rated on standardized measures of cognitive impairment,
depression, extrapyramidal symptoms, functional impairment and general health.
RESULTS: Seventy-five (22%) AD patients had delusions only, nine (3%) had
hallucinations only and 30 (9%) had both delusions and hallucinations.
Hallucinations were associated with less education, African-American race, more
severe dementia, longer duration of illness, falls and use of anxiolytics.
Delusions were associated with older age, depression, aggression, poor general
health and use of antihypertensives. Patients with both delusions and
hallucinations were similar to the patients with delusions only. CONCLUSIONS:
This study confirms the high prevalence of psychotic symptoms in AD patients
encountered in clinical practice and suggests that individual psychotic symptoms
have different associations.
PMID- 10679841
TI - Is aggressive behaviour influenced by the use of a behaviour rating scale in
patients in a psychogeriatric nursing home?
AB - OBJECTIVE: To study the influence of the introduction of a behaviour rating scale
on reported incidence and management of aggressive behaviours in patients in a
psychogeriatric nursing home. DESIGN: An 8-month prospective cohort intervention
study. SETTING: Two wards of a Dutch psychogeriatric nursing home with residents
of 65 years and older. PATIENTS: All residents of the two wards were included
(N=75). INTERVENTION: Social Dysfunction and Aggression Scale (SDAS) assessed at
weekly intervals during 4 months after a 4 months' baseline period. ASSESSMENTS:
During 8 months at 2 months' interval the BOP (ie the validated Dutch version of
the Stockton Geriatric Rating Scale); frequency of aggressive behaviour reported
at daily nursing staff report; mean prescriptions of psychotropic and somatic
drugs; number of days a patient was submitted to physically restrictive measures.
RESULTS: Eleven patients (N=11) did not complete the study; information on 64
patients was analysed. The frequency of aggressive behaviour reported by the
nursing staff increased, while prescriptions of psychotropic drugs decreased. No
alteration was found for BOP scores, mean prescriptions of somatic drugs and the
use of physically restrictive measures. CONCLUSIONS: The introduction of a
behaviour rating scale does influence the reported incidence and management of
aggressive behaviour. Prospective intervention studies should include a
stabilization phase for measurements prior to any planned trial.
PMID- 10679843
TI - Do personality traits predict the occurrence of Alzheimer's disease?
AB - OBJECTIVE: To identify specific premorbid personality traits in patients with
Alzheimer's disease (AD). DESIGN: A prospective case-control study. SETTING: A
memory clinic of a department of geriatric medicine in a teaching hospital.
PATIENTS: Fifty-six consecutive patients with probable AD. Sixty-five controls
with Parkinson's disease (PD). MEASURES: Premorbid personality traits were
assessed using the relative rating version of the Munich Personality Test (MPT).
RESULTS: The AD patients showed higher neuroticism than the controls with PD
(p=0.013). In comparison with MPT normative values for psychiatric inpatients,
the AD patients scored significantly (p<0.05) lower on neuroticism and higher on
frustration tolerance and rigidity. CONCLUSION: Our results support the
assumption of specific premorbid characteristics in AD patients, ie increased
neuroticism and rigidity. More research is needed to confirm the existence of
typical premorbid personality traits in AD.
PMID- 10679842
TI - Factors predicting the relapse of depression in old age.
AB - BACKGROUND: Studies in mixed-aged populations show differences between the
predictors of a relapse and those of a long-term course of depression, supporting
the hypothesis about similar differences among the aged. AIM: The aim was to
identify the factors predicting or related to a relapse of depression among the
Finnish elderly having recovered from depression during treatment. MATERIAL AND
METHODS: The population consisted of 70 depressed (DSM-III criteria) elderly (60
yr-) Finns having recovered from depression during treatment as determined 15
months after baseline. By the 4-year follow-up after the recovery, 20 patients
had relapsed and 50 persons were non-depressed. RESULTS: The logistic regression
model showed major depression and psychomotor retardation to be independent
predictors. Relapses were not related to stressors in life or physical illnesses
occurring during the follow-up. CONCLUSIONS: Major depressive elderly patients
have a high risk for relapses without the occurrence of the stressors or physical
illnesses. In clinical practice, major depressive elderly patients should be
followed up in order to detect and treat potential relapses as early as possible.
Cooperation between psychiatrists and general practitioners is needed in the
follow-up. Theoretically, the results suggest the assumption of a biochemical
aetiology of major depression.
PMID- 10679844
TI - A pilot study of sibling resemblance in later life.
AB - OBJECTIVE: Behavioural genetic studies of later life are strictly limited. We
carried out a community-based pilot study of sibling resemblance with the primary
aims of establishing the feasibility of such work in this population and
estimating genetic influence on depression and its risk factors. METHODOLOGY:
Data were collected on surviving siblings of individuals interviewed in previous
phases of an epidemiological study of the elderly (the Gospel Oak survey); scales
relevant to the investigation of late life depression and its risk factors were
utilized. Since families tend to be geographically scattered, the interview was
conducted by telephone. Comparisons were made between data relating to the
siblings and those obtained on the probands. Variability in phenotypic traits and
environmental measures was partitioned into between- and within-family variation,
in order to distinguish familial and non-familial sources of variation.
Intraclass correlations were used to estimate the strength of genetic influences
on continuous measures, while pairwise concordances were calculated for
dichotomous traits. RESULTS: Thirty-two siblings from 20 families were ultimately
identified and interviewed. Intraclass correlations for the Depression and
Dementia Diagnostic Scales and the Handicap Scale were 0, 0.27 and 0.22,
respectively. Those for number of life events, number of friends in contact and
number of neighbours in contact were 0.08, 0.03 and 0, respectively. Concordance
for both depression caseness and dementia caseness was 0. DISCUSSION: There were
difficulties carrying out this study, which are discussed. The study is the first
of its kind to examine familial resemblance for the common disorders of old age.
Establishing ways of engaging elderly families with research will be a challenge
that future research will need to meet.
PMID- 10679845
TI - Development of simple cognitive function measures in a community dwelling
population of elderly in Spain.
AB - OBJECTIVE: To develop and assess the consistency and validity of simple cognitive
function measures for an elderly population with low levels of formal education
for use in a longitudinal study of dementia. METHODS: Data were from the
population longitudinal study 'Growing old in Leganes' (Spain). In 1993, a random
sample of 1540 people over 65 was drawn from the City Roll of Leganes from which
1284 (83%) were successfully interviewed. Measures of memory and orientation were
based on the SPMSQ (Short Portable Mental Status Questionnaire), the Barcelona
test and the short story from EPESE (Established Populations Epidemiologic
Studies of the Elderly). Non-response to a test item was coded as an error.
Internal consistency was assessed by factor analysis and Cronbach's alpha.
Construct validity was examined with multiple linear regressions of the proposed
measurements on variables chosen from the existing literature on cognitive
function. RESULTS: Two factors, memory and orientation, emerged from the factor
analysis. Internal consistency of the proposed indexes for memory and orientation
was acceptable. Memory and orientation scores were summed into one summary index
of cognition. Associations between covariates and both cognitive indexes were in
the expected direction. Among those highly functional, orientation was influenced
by illiteracy due to higher error rates in the time orientation items based on
dates; however, memory and summary scores were not significantly different by
literacy status. A large proportion of the variance in IADL was explained by the
memory and orientation measures. CONCLUSION: The memory and orientation indexes
are valid and reliable measurements of cognitive function for use in a population
of community dwelling elderly with low levels of formal education and high rates
of illiteracy.
PMID- 10679846
TI - The effects of emotion-oriented approaches in the care for persons suffering from
dementia: a review of the literature.
AB - OBJECTIVE: This article presents an overview of the results of intervention
studies in various emotion-oriented approaches in the care for people suffering
from dementia. Recommendations are made with regard to clinical practice and
future research. DATA SOURCES: We searched for references (1990-99) in several
bibliographical databases, i.e. Medline, PsycLit, Embase, Sociofile and Current
Contents. The terms 'dementia' and 'Alzheimer's disease' were linked separately
to the search terms: emotion-oriented, validation (therapy), sensory
integration/sensory stimulation/snoezelen, simulated presence therapy and
reminiscence (therapy)/life-review. Based on references in the articles found,
other publications were traced. STUDY SELECTION: We started from the 'emotion
oriented' approaches used in 24-hour care distinguished by the American
Psychiatric Association (1997) i.e. validation, sensory stimulation/integration,
simulated presence therapy and reminiscence. We selected research articles that
describe intervention, design, measuring instruments and results. DATA
EXTRACTION: The articles were analyzed with regard to research group, setting,
design, effect variables, intervention, measuring instruments, statistical
analyses and results. DATA SYNTHESIS: It is shown that mainly positive results
(including increased social interaction and decrease of behavior problems) are
achieved with these emotion-oriented approaches. Unfortunately many studies have
methodological limitations and are done independently, which makes comparison
difficult. CONCLUSIONS: Despite the limited cogency of the studies we traced, the
results are promising. Emotion-oriented care approaches offer the opportunity to
tailor the care to the individual needs of dementing elderly and can be
complemented with other psychosocial approaches (e.g. psychomotor therapy and
music therapy) when necessary. The challenge for the care sector is to develop
guidelines to determine which approach should be applied to whom and when.
Scientific research can contribute by examining which emotion-oriented
approaches, possibly in combination with each other or with psychosocial
therapies, effect an increase in the well-being and improve functioning in which
patients.
PMID- 10679847
TI - Suicidal ideation in acutely medically ill elderly inpatients: prevalence,
correlates and longitudinal stability.
AB - BACKGROUND: Suicidal ideation among acutely medically ill elderly inpatients has
been sparsely studied. A prospective study measuring the prevalence, correlates
and longitudinal stability of suicidal ideation in acutely medically ill elderly
inpatients was undertaken. METHOD: Suicidal ideation was measured using the Beck
Scale for Suicidal Ideation (BSSI) and the items of pessimism, life not worth
living and a wish to die on the Brief Assessment Schedule (BAS). Formal measures
of physical illness, functional disability and handicap were also used. Patients
were seen at the outset and at about 6 months. RESULTS: The prevalence of
suicidal ideation on the BSSI and the BAS items of pessimism, life not worth
living and a wish to die were 36%, 60%, 33% and 22%, respectively. These four
variables were significantly inter-correlated. The BSSI was significantly
associated with BAS depression scores (P=0.0001), BAS depression caseness
(P=0.0001) and prescription of antidepressants (P=0.007). Similar results were
ascertained for the BAS items of pessimism, life not worth living and a wish to
die. CONCLUSIONS: Further studies examining the longitudinal stability of
suicidal ideation coupled with intervention studies to reduce suicidal ideation
are required.
PMID- 10679848
TI - Can chronic neuroleptic treatment promote sleep disturbances in elderly
schizophrenic patients?
AB - It has been proposed that sleep disturbances, especially reduced delta sleep, are
related to a poor outcome in schizophrenia. To determine whether long-term
treatment with neuroleptics can promote sleep disturbances by increasing the risk
of a nocturnal myoclonus syndrome (NMS) (=periodic movements in sleep) related
insomnia, we performed all-night polysomnography in 10 chronically ill
schizophrenic patients who had been under neuroleptic therapy for a mean of 27
years. NMS-related insomnia was detected in all 10 patients. Potential
pathophysiological relationships between long-term neuroleptic therapy and NMS
occurrence are discussed. Our findings suggest that long-term administration of
neuroleptics favours the appearance of insomnia.
PMID- 10679849
TI - Sertraline in the treatment of minor depression in nursing home residents: a
pilot study.
AB - 'Minor' depression affects up to 50% of residents in long-term care facilities
and is associated with considerable discomfort, disability and risk of morbidity.
Despite the prevalence of this problem, few studies addressing the treatment of
these patients have been conducted. In an open clinical trial, 12 nursing home
residents who met the DSM-IV description for minor depressive disorder were
treated with sertraline for 6 weeks. Adverse effects and clinical response were
monitored. All residents tolerated their medication without any significant side
effects. At the completion of the study, the Hamilton Depression Rating Scale and
Global Assessment Scale change scores both indicated significant improvement and
75% of the residents met criteria for 'remission'. This preliminary study
provides evidence that nursing home residents with minor depression tolerated
treatment with sertraline and improved clinically.
PMID- 10679850
TI - Quality of life in dementia patients in long-term care.
AB - OBJECTIVE: To evaluate variables associated with quality of life (QOL) in
dementia residents in a long-term care facility using a recently standardized and
validated dementia-specific QOL scale (ADRQL). METHOD: A cross-sectional, case
control design was employed using validated scales to assess dementia-related
symptomatology. Thirty-two facility staff members were interviewed to assess the
QOL of 120 patients meeting DSM-IV for dementia criteria residing in long-term
care. RESULTS: ADRQL scores were higher in assisted living residents than in
skilled nursing facility residents. In univariate analyses, worse orientation,
greater physical dependency, depression, and treatment with anxiolytics were
associated with lower ADRQL scores. In multivariate analyses, lower scores were
associated with worse orientation, greater physical dependency, depression, and
anxiolytic treatment. CONCLUSIONS: Residents exhibited better QOL than expected.
Future longitudinal studies should address if reorientation, activity therapy,
treatment of depression, and avoidance of benzodiazepines might improve QOL in
this population. Interventions that might improve orientation and physical
abilities, such as cholinomimetic therapies, psychosocial interventions, or
behavioral strategies, should also be studied in future research on QOL.
PMID- 10679851
TI - Anastomosis between the external branch of the superior laryngeal nerve and the
recurrent laryngeal nerve.
AB - An incidental finding in the anatomy lab showed up a plexus of the external
branch of the right superior laryngeal nerve (SLN), including an anastomosis with
the recurrent laryngeal nerve (RLN). The external branch of the SLN divided in
two extensions: The ventral extension reached the mesopharynx laterally and by
supplying the latter, ended at the cricothyroid muscle. The dorsal extension
formed a plexus a finger's breadth beneath the inferior margin of the pharynx, on
the lateral aspect of the esophagus. The anastomosis ran from the lower part of
the plexus to the RLN along the esophagus, laterally.
PMID- 10679852
TI - Radiological anatomy of the intratemporal course of facial nerve.
AB - Preoperative evaluation of the facial nerve (FN) anatomy within the temporal bone
by high-resolution computed tomography (HRCT) helps in minimizing surgical trauma
to the nerve. In order to demonstrate the radiological correlation of the
intratemporal FN, eight adult, formalin-preserved cadavers were studied by
comparing the transaxial and coronal sections of HRCT with anatomic
microdissection findings. It was possible to visualize all segments of the FN
canal in its intratemporal course. The most difficult part of the FN to
demonstrate was the pyramidal section. Anatomic microdissection findings were
consistent with the HRCT images. It was concluded that adequate information on
the FN anatomy could be obtained from standard HRCT scans.
PMID- 10679853
TI - Cadaver profile at university of Stellenbosch Medical School, South Africa, 1956
1996.
AB - Data on 1,698 cadavers donated during the period 1956-1996 were obtained from
files of the Department of Anatomy and Histology at the University of
Stellenbosch Medical School, Tygerberg Hospital, South Africa, to project a
profile of the characteristics of those accepted on the program for dissection. A
breakdown of the data also provided information on the profile of donors
belonging to different population groups. Donors to our program were
predominantly male (68%) and predominantly colored, which in South Africa
identifies those of mixed heritage (63%). The average age of death was 55 years
(range 15-98). Donors belonging to the white population group had the highest
female : male ratio. Circulatory disorders accounted for most deaths in the white
population group (48%), whereas cancer was the leading cause of death in the
colored and black population groups ( approximately 25%). Pulmonary tuberculosis
accounted for 13% deaths in the colored population group, 14% of deaths in the
black population group, but only 0.5% of deaths in the white population group.
Cervical cancer and breast cancer accounted for approximately one-third of cancer
deaths in women, with cervical cancer more common in colored and black female
donors and breast cancer more common in white female donors. The cadaver profile
in general reflects the health status of the different population groups in South
Africa. The profiles of the colored and black groups reflect that of
disadvantaged population groups (a high prevalence of infectious disease;
relatively young populations), whereas the white donor profile is that of a
privileged population group (a high prevalence of degenerative disease; aging
population).
PMID- 10679854
TI - Anatomical knowledge and clinical evaluation of the muscles of mastication.
AB - In this survey, we identify the positive role that an instructional anatomy
course has prior to a workshop on temporomandibular dysfunction. Not only did it
result in enhanced clinical evaluation of the muscles of mastication acquired by
the participants, but it also approximated the skills of dental and medical
practitioners.
PMID- 10679855
TI - Theoretical and analytical embryology of conjoined twins: part II: adjustments to
union.
AB - A previous report in this journal (Spencer, 2000) discussed the probable
embryologic etiology of conjoined twins, along with a system of classification
based on the embryological structures postulated to be involved in the union.
Part II correlates and compares the variations in the abnormal development of the
individual organ systems in more than 1,200 actual cases, revealing details of
embryogenesis not considered in previous publications. The site, incidence, and
range of anomalies in the conjoined structures, as well as the associated
malformations, follow a definite pattern as the union proceeds from one area to
another; many can be explained in relation to the proposed embryologic
adjustments to union, including both temporal and spatial influences. In
addition, six currently inexplicable or unclassifiable cases are briefly
described (including one with 12 feet), as well as two examples of early abnormal
conjoined twins.
PMID- 10679856
TI - Position, shape, and dimension of the maxilla in unoperated cleft lip and palate
patients: review of the literature.
AB - The inhibition of growth and development resulting from surgical treatment of the
cleft lip and palate is a widely discussed topic. Various studies have been
conducted in search of answers as to how the untreated upper jaw develops,
focusing on individuals with untreated cleft lip and palate as found in so-called
Third World countries. This study offers the opportunity to compile literature
dealing with the research and description of untreated unilateral cleft lip and
palate. The focus was to take a closer look at groups of individuals with
complete unilateral cleft lip and palate, who had received no surgical treatment
at all, as well as groups who had received surgical treatment of only the cleft
lip. The upper jaw of untreated cleft lip and palate patients most often adopts a
protruded position without enlarging the maxilla itself. The horizontal dimension
tends to be reduced, whereas the vertical dimension is normal. The upper jaw of
patients with unilateral cleft lip and palate who received surgical treatment of
the lip more often adopted a retruded position. The model analysis showed no
clear-cut tendencies. There seemed to be a degree of regional variation.
Considering the relatively small number of recruitable individuals with untreated
cleft lip and palate, the introduction of a standard method of evaluation is
desirable. This would significantly facilitate the comparison of different
studies with each other in the future. The first steps in this direction have
already been initiated.
PMID- 10679857
TI - Aberrant left gastric vein directly draining into the liver.
AB - An aberrant left gastric vein found in dissection is reported here. The right
gastric vein did not exist and only the left gastric vein originating from the
lesser curvature of the stomach was present. It directly entered the liver
without typically joining the trunk of the portal vein. After giving off a small
branch to the liver parenchyma, the left gastric vein merged into the left branch
of the portal vein. This aberrant left gastric vein may correspond to the
phylogenetic and ontogenetic "left portal vein." The aberrant left gastric vein
is considered to play an important role as a portal collateral pathway of the
portal system, which is critical not only in anatomy but also in clinical
diagnosis.
PMID- 10679858
TI - Sternalis muscle: topic for debate.
PMID- 10679859
TI - The new anatomy: A forecast of hope
PMID- 10679860
TI - Standards in health care and medical education.
PMID- 10679861
TI - What is anatomy? Implications for anatomy as a discipline and for Clinical
Anatomy as a journal.
AB - Anatomy as a discipline is explored against a background of the growth of
scientific knowledge and developments within modern universities. The structural
overtones of anatomic approaches provide intellectual cohesion for the approaches
of complementary disciplines. When anatomy departments function in a
transdisciplinary manner, they encompass a range of areas from molecular biology
to functional anatomy and biological anthropology. Suggestions are made for a
journal, such as Clinical Anatomy, to provide stimulus for the further
development of anatomy as a coherent discipline.
PMID- 10679862
TI - Preface
PMID- 10679863
TI - A framework for assessing health-related quality of life among children with
cancer.
PMID- 10679864
TI - Commentary on assessing health-related quality of life in children with cancer.
PMID- 10679865
TI - The Miami pediatric quality of life questionnaire: parent scale.
AB - Because there were limited measures available to assess health-related quality of
life (HRQL) in children with chronic illnesses, this study was initiated to
develop an empirically derived questionnaire for use in evaluating HRQL issues in
children treated for cancer. Extensive interviews were conducted with 30 families
of children with cancer, 10 of pre-school age, 10 of school age and 10 of
adolescent age. Responses were videotaped and transcribed, then categorized to
develop a pool of 56 items, which were administered to 132 children with cancer
and to their parents. This report focuses on parental responses to objective
items and ratings of importance of each of these items. Three primary categories,
Self-Competence, Emotional Stability and Social Competence, were identified, each
of which had solid internal consistency, sensitivity and reliability across 1
month intervals. The measure demonstrated the ability to discriminate between
children with different types of cancer, offers an alternative to measures
relying on expert judgment to assess HRQL and may lead to greater inclusion of
psychological and social concerns as primary factors in determining HRQL in
children participating in clinical trials.
PMID- 10679866
TI - Assessment of health-related quality of life in acute in-patient settings: use of
the BASES instrument in children undergoing bone marrow transplantation.
AB - The Behavioral, Affective and Somatic Experiences Scale (BASES) represents a set
of tools for assessing aspects of health-related quality of life (HRQL) in
patients undergoing active, intensive therapy. Separate versions have been
developed for parent, nurse and patient reports. The scales were constructed to
be sensitive to change and appropriate for repeated measures in longitudinal
designs. We report preliminary results with these measures from a sample of 105
children undergoing bone marrow transplantation (BMT). Adequate reliability of
the instruments is documented through measures of both internal consistency and
cross-informant consistency. Several analyses provide evidence of the clinical
validity of the measures. Repeated-measures ANOVAs indicated reliable patterns of
change over time, with trajectories that conformed to a priori predictions.
Discriminative validity was demonstrated through detection of significant
differences in the predicted direction between patients undergoing allogeneic and
autologous BMT. Additional evidence for validity comes from the very similar
symptom trajectories in parent, nurse and patient reports. Differences between
the BASES and other measures of HRQL are identified and alternative uses of the
instruments are discussed.
PMID- 10679867
TI - Health status and health-related quality of life in long-term adult survivors of
pediatric solid tumors.
AB - We have examined the influence of selected factors (gender, marital status, socio
economic status, co-morbid conditions, access to medical care, age at diagnosis,
intensity of therapy and time since diagnosis) on subsequent health status and
health-related quality of life (HRQL) of long-term survivors of pediatric solid
tumors. Two hundred and twenty individuals who had survived a pediatric solid
tumor 15 years or longer completed telephone and written assessments of their
current status. Health status was assessed using the Late Effects of Normal
Tissues toxicity scale. HRQL was investigated using the Ferrans and Powers
Quality of Life Index-Cancer (QLIC) and the EORTC Quality of Life Questionnaire
C30 (QLQ-C30). Results indicated that health status and HRQL were better in
survivors treated with low-intensity therapy. One hundred and thirty respondents
(59.1%) reported at least 1 serious toxicity. Dyspnea and fatigue were commonly
reported in survivors of Hodgkin's disease. Correlational analyses showed that
predictors of health status included socio-economic status, marital status and
the presence of co-morbid factors. Mean HRQL scores for the 4 domains of the
Ferrans and Powers QLIC and the functional scales of the EORTC QLQ-C30 indicated
that most of the survivors were experiencing moderately good to excellent HRQL.
One-third of survivors reported that their history of cancer had an adverse
impact on their current financial status. Prediction models constructed for 3 of
the domains from the 2 HRQL instruments are presented (health and functioning,
global HRQL and financial impact). Within these 3 models, consistent predictors
of HRQL outcomes included health status, presence of dyspnea or pain, marital
status and socio-economic status.
PMID- 10679868
TI - Assessment of health status and health-related quality of life in survivors of
Hodgkin's disease in childhood.
AB - Although the great majority of children with Hodgkin's disease survive with
modern treatment strategies, the list of late sequelae is long, yet there is no
published information on the comprehensive health status and health-related
quality of life (HRQL) in this population. In the experience of a single
institution, survivors of Hodgkin's disease in childhood were invited to self
report on their health status using a 15-item questionnaire connected to the
Health Utilities Index, a series of multi-attribute health status classification
systems that, in turn, are linked to preference functions which provide single
attribute and global utility scores for HRQL. The mean global utility score was
0.85 (on a 0 = dead to 1. 0 = perfect health scale), a figure less than that in
survivors of acute lymphoblastic leukemia (ALL) but comparable to that in
survivors of brain tumors (0.84) or extremely low birthweight (ELBW 0.82). The
burden of morbidity is emphasized by the ratio of the numbers of health states
per patient:0.67 for survivors of Hodgkin's disease, 0.66 for survivors of brain
tumors, 0.39 for survivors of ELBW, 0.47 for survivors of high-risk ALL and 0.28
for survivors of standard-risk ALL. In Hodgkin's disease survivors, the
attributes affected most commonly and severely were pain, cognition and emotion.
This experience demands exploration of the health status and HRQL in a much
larger cohort of such survivors, perhaps in the context of co-operative group
studies.
PMID- 10679869
TI - A comparison of parent and adolescent reports describing the health-related
quality of life of adolescents treated for cancer.
AB - Our objectives were to compare adolescent and parent ratings of the health
related quality of life (HRQL) of adolescents treated for cancer, to compare the
HRQL of adolescents who were on treatment vs. the HRQL of those who were off
treatment following their diagnosis with cancer and to assess the HRQL of
adolescents who were at different points of time following their diagnosis with
cancer. The HRQL of 70 adolescents (aged 10 to 18 years) consecutively attending
the Women's and Children's Hospital Oncology Clinic in South Australia was
assessed by means of standard questionnaires. Parents completed the Child Health
Questionnaire, the Functional Status II(R) Questionnaire and the Impact-on-Family
Scale. Adolescents completed the self-report version of the Child Health
Questionnaire. In general, there was good agreement between parent and adolescent
reports. However, parents of adolescents receiving active treatment for cancer
reported that their illness was having a greater impact on the adolescents'
physical functioning than was reported by the adolescents. The psycho-social
functioning of adolescents in single-parent families was reported also by parents
to be worse than that of adolescents in 2-parent families. The physical
functioning of adolescents had only a weak relationship with parental status but
a significant relationship with treatment status. Despite generally good
agreement between parent and adolescent reports describing the HRQL of
adolescents treated for cancer, it cannot be assumed that reports from parents
are always an accurate reflection of the views of the adolescents. Studies
examining the influence of independent factors on adolescents' HRQL must take
into account differences in reports from these 2 informants and the possibility
that key independent variables have differing relationships with the various
domains which comprise adolescents' HRQL.
PMID- 10679870
TI - Health-related quality of life in pediatric bone marrow transplant survivors:
according to whom?
AB - Historically, health-related quality of life (HRQL) assessment in pediatrics,
including the few validated instruments in pediatric oncology, has been based on
proxy reporting, relying primarily on parental assessment. Children have been
deemed incapable of providing consistent and reliable information about their
level of functioning or state of well-being. Previous studies have been hampered
by either limited or poor correlation among the proxy reporters, i.e., teachers,
parents and physicians, and in comparisons to disease severity. Simply stated,
proxy reporters have greater agreement about what the child can do vs. what the
child thinks or feels. Comparisons among proxy reporters have been hindered also
by a lack of parallel content in the instruments used, which may result in poorly
congruent assessments simply because the instruments measure different
constructs. In addition to the measurement issues, the emotional milieu of the
parent, particularly the mother, has been shown to influence assessments of the
child's functioning. Maternal distress, marital adjustment and health locus of
control all co-vary with reports of the child's behavior. What, then, is the
proxy reporter telling us about the child? We conducted a cross-sectional study
of school-aged pediatric bone marrow transplant (BMT) patients at our institution
to evaluate children's self-reported HRQL and functional status. We formally
tested the Child Health Rating Inventories (CHRIs), a recently developed generic
health-status measure, with its companion measure, the Disease Impairment
Inventories-Bone Marrow Transplant (DSII-BMT). Separate questionnaires were
administered to patients, parents and physicians at a scheduled outpatient visit
after BMT. The questionnaires were designed to have parallel content. All
responses were confidential. The psychometric properties of the CHRIs and DSII
BMT are reported elsewhere. In brief, the responses of all raters were reliable,
based on measurements of internal consistency. The children's self-reported
health status was correlated significantly with the physicians' disease severity
rating (DSR) across all generic and disease-specific domains. In contrast,
parental reports of child health status were not correlated significantly with
the DSR for disease-specific problems or the child's pain. Parental ratings
deviated most from the children's ratings within the dimensions of mental health
and quality of life (p < 0.001). For the entire sample, parental ratings were
significantly lower than the children's ratings. Within the subgroup "early after
transplant (<6 months)", parental ratings were significantly lower than the
children's self-reports in all categories. In the subgroup ">12 months after
transplant", with the exception of mental health and quality of life, parental
scores were the same as or higher than the children's ratings. Our results
confirm previous studies that the parental reporting of children's health status
is a complex construct and that valuable information can be elicited directly
from the children. Further research is needed to substantiate these findings,
particularly in longitudinal applications with adequate sample sizes.
PMID- 10679871
TI - Somatization, anxiety and depression as measures of health-related quality of
life of children/adolescents with cancer.
AB - This descriptive study of health-related quality of life of children with cancer
compared children/adolescents', parents' and teachers' ratings for somatization,
depression and anxiety to determine if there were significant correlations among
respondent scores. In addition, the percentage of agreement among respondents and
significant differences based on age, gender, use of cranial radiation and
treatment status were measured. Forty-three children/adolescents with cancer,
currently receiving therapy for at least 1 year or who had completed therapy for
no more than 3 years (excluding children who had received bone marrow transplants
or who had brain tumors), were recruited, with a parent and teacher, from 3
university medical centers. The Behavioral Assessment System for Children
questionnaires for children/adolescents, parents and teachers were used. Parents
reported a higher level of depression for the children/adolescents with cancer
than did the teachers or the children/adolescents themselves. Parents reported a
higher level of anxiety for the children/adolescents than did the teachers. High
positive correlations were found among scores from parents and teachers and among
scores from parents and children/adolescents for the anxiety and depression but
not somatization subscales. Children/adolescents and teachers had high,
positively correlated scores only for the depression subscale. High, positive
correlations were found between somatization, anxiety and depression within each
group of respondents. A significant percentage of agreement between all
respondents on ratings for at-risk status was obtained only for the depression
subscale. Age was the only variable found to have an influence on scores and only
for the anxiety subscale.
PMID- 10679872
TI - Health-related quality of life in childhood cancer: discrepancy in parent-child
reports.
AB - The purpose of our study was to describe reports of parents and of children with
cancer on items taken from 4 domains of health-related quality of life (HRQL),
bodily pain/distress, general health perceptions, physical functioning and
limitations in role/social functioning as a result of physical health, and to
examine whether differences in parent-child reports varied as a function of the
child's health condition (cancer vs. healthy). Twenty-seven child-parent dyads
with cancer and 27 child-parent dyads who were healthy (child ages 8 to 18
inclusive) completed measures of child HRQL [Child Health Questionnaire-Parent
Form (CHQ-PF50) and Child Health Questionnaire (CHQ-CF87)] and demographic
information at a scheduled out-patient general pediatric or pediatric oncology
clinic appointment. Sixteen items included on both the CHQ-CF87 and CHQ-PF50 were
examined to compare parent and child reports of child HRQL. As hypothesized,
greater discrepancies were evident in the reports of parents of children with
cancer than parents of children who are healthy [F(16,31) = 3.98, p < 0.0001].
Statistically significant discrepancies emerged in parent and child responses on
50% of the items in the sample of children with cancer, with parents reporting
that their children experience more limitations in their lives than did the
children themselves. In the healthy group, statistically significant
discrepancies emerged on only 1 of the 16 items (6.3%).
PMID- 10679873
TI - Development of the Royal Marsden Hospital paediatric oncology quality of life
questionnaire.
AB - Our objective was to develop a health-related quality of life measure for use in
pediatric oncology. The development process followed the EORTC Quality of Life
Study Group (QLSG) guidelines but utilized a parental proxy rating methodology
developed within the framework of the EORTC QLSG. Data are reported on the
preliminary stages of development, which include interviews in the target
population, specialist review of questionnaire content and initial results on the
psychometric structure of the measure. The questionnaire has been translated from
English to Swedish and Dutch and is available for international field testing.
Suggestions for further development of the new measure are described, including
the need for parallel forms for use with children and adolescents as well as the
parental proxy rating form described here.
PMID- 10679874
TI - The Pediatric Cancer Quality of Life Inventory: a modular approach to measuring
health-related quality of life in children with cancer.
AB - Measurement of pediatric cancer patients' health-related quality of life (HRQL)
in phase III randomized, controlled clinical trials is being recognized
increasingly as an essential component in evaluating the comprehensive health
outcomes of modern anti-neoplastic treatment protocols. Use of a brief core
measure of HRQL plus disease-specific symptom modules is a way to assess specific
HRQL outcomes with a minimum of subject burden. Demonstrating a measure's
feasibility, reliability and validity also represents children's ability to
provide reliable and valid responses to HRQL questions. The Pediatric Cancer
Quality of Life Inventory (PCQL) Modular Approach consists of a 15-item core
measure of HRQL and 2 specific symptom modules: pain and nausea. To validate a
patient-report form and a parent-report form, the PCQL was administered to 291
pediatric cancer patients and to their parents. Feasibility and range of
measurement, as well as patient-parent concordance, were assessed. Internal
consistency reliability was assessed via Cronbach's alpha. Validity was
determined by the known-groups approach and by correlating PCQL scores with days
missed from school. Patients had minimal missing data, and the range of
measurement for the items was good. Patient-parent concordance was large but not
perfect. For both patient and parent forms, internal consistency reliability of
the PCQL core scale (0.83 and 0. 86, respectively) was strong. The internal
consistency reliabilities of the 2 symptom modules for both patient and parent
forms were in the acceptable range for group comparisons. Regarding clinical
validity, the core scale and the 2 symptom modules distinguished between patients
on and off treatment for both patient and parent reports. Further, both patient
and parent reports correlated with days of missed school in the past 6 and 12
months. The PCQL Modular Approach has demonstrated acceptable internal
consistency reliability and clinical validity for both patient-report and parent
report forms. By implication, children are capable of providing reliable and
valid responses to these HRQL questions.
PMID- 10679875
TI - Standardized quantitative assessment of brain tumor survivors treated within
clinical trials in childhood.
AB - Important morbidity and impairment of life quality arises from both the primary
pathology and therapeutic interventions in children with central nervous system
(CNS) tumors. Standardized and systematic collection of morbidity data is a
prerequisite of clinical trials in this field. The perception of the survivor is
paramount in the determination of quality of life as this variable is dependent
on the beholder. Comprehensive assessment of outcome following therapeutic
intervention should evaluate this in parallel with other physical and psycho
social outcome parameters. A structured, simple schema for the evaluation of
survivors of childhood CNS tumors is presented. It is intended to be easily
applicable by clinicians within the everyday clinical setting. Information
relating to pre- and post-operative states, function, health status and emotional
and psychological well-being is collected at regular intervals from diagnosis. Re
integration into society and independence are evaluated. Children self-complete
health-status assessments where appropriate. Evidence to support this is
presented. The schema is intended to provide a basic framework for the monitoring
of health status following treatment of CNS tumors in childhood. Regular
assessments may identify individuals in need of more detailed investigation and
further understanding of the evolution of morbidity in this cohort. Survivors'
perception of the impact of documented dysfunction on their health-related
quality of life will be determined. Optimization of the planning of future
clinical service provision and therapies will result.
PMID- 10679876
TI - Studies on health-related quality of life in childhood cancer in the European
setting: an overview.
AB - Since the beginning of the 1990s there has been a growing interest, in the
European setting, in evaluating health-related quality of life (HRQL) in clinical
studies. Assessing HRQL in childhood cancer survivors, in particular, is a new
field of research. Studies of survivors of leukemia and brain tumors are of
special interest since these are the commonest groups of survivors of cancer in
childhood. Initial reports suggest that most of the survivors of childhood cancer
are in good health with a normal psychosocial status, social life and capacity to
cope with activities of daily living. More discriminative evaluations identify a
number of subtle problems, such as cognitive deficits in brain tumor survivors or
anxiety about a recurrence (especially) in children who have had megatherapy and
autologous bone marrow rescue. In this group, pain is also a lasting problem in
about one-third of patients. The main problem in these studies is comparability
as the study designs vary widely. Little information is available with respect to
inter-observer agreement, which is important since it is known that proxy
respondents will under- or over-estimate components of the HRQL of the child. The
most important base for further development of HRQL research is communication
between researchers, in order to exchange experience and to avoid duplication of
effort. Communication is necessary also for combining interests and forces in
developing a standardized methodology as well as for conducting collaborative
studies using equivalent measures.
PMID- 10679877
TI - Health-related quality-of-life measures for children.
AB - Our purpose is to report the development and psychometric properties of a generic
computer-delivered measure of health-related quality of life (HRQL) suitable for
children aged 6 to 11 years, the Exeter HRQL scale (EHRQL). The theoretical model
adopted is based on a definition of HRQL which assumes that HRQL is the result of
discrepancies between an individual's actual self and ideal self. The EHRQL
consists of 16 pictures, each of which is rated twice, first in terms of "like
me" and second as "I would like to be". The difference between these scores is
assumed to be indicative of HRQL. The EHRQL is delivered using a Macintosh
Powerbook and takes approximately 20 min. Data are reported for 60 children with
asthma (mean age = 8.93 years) and 69 healthy children (mean age = 7.49 years).
In addition, children with asthma completed the Childhood Asthma Questionnaire
(CAQ) and a measure of self-efficacy. For children with asthma, significant
correlations were found between discrepancy scores and 3 of the 4 subscales of
the CAQ. In addition, higher discrepancies were found for children with asthma
compared with healthy children (p < 0.05). The EHRQL has acceptable internal
reliability, and these data provide preliminary support for the theoretical
assumption that HRQL reflects perceived discrepancies between an individual's
actual self and ideal self. The measure also distinguished, as predicted, between
children with asthma and healthy children. Methodological refinements to the
EHRQL are suggested.
PMID- 10679878
TI - Correlation of the Health Utilities Index Mark 2 cognition scale and
neuropsychological functioning among survivors of childhood medulloblastoma.
AB - Children surviving medulloblastoma have a high risk for chronic, treatment
related neurocognitive deficits. Neuropsychological testing provides important
data regarding the comparative toxicities of various therapeutic approaches.
However, such testing can be expensive and logistically difficult, especially if
a consulting psychologist is not readily available at the treating institution.
Our purpose was to investigate the usefulness of a health-related quality of life
inventory that does not require a psychologist for completion. We assessed the
concurrent validity of traditional intelligence (IQ) testing and levels on the
Cognition attribute of the multi-attribute Health Utilities Index Mark 2 (HUI 2)
in estimating academic achievement scores of 22 patients treated for
medulloblastoma with craniospinal irradiation following surgical resection. The
results demonstrated that the Cognition utility scores were significantly lower
than scores from the other components of the HUI 2 (Sensation, Mobility, Emotion,
Self-Care, Pain). Cognition scores were also significantly positively correlated
with IQ and achievement scores. Furthermore, Cognition scores were significantly
lower among children who had received special educational services when compared
with those who had not received such services. Our results provide preliminary
evidence of the potential usefulness of the HUI 2 Cognition attribute in
estimating IQ, achievement and the likelihood of the need for special educational
services among children treated for medulloblastoma.
PMID- 10679879
TI - Mutual concurrent validity of the child health questionnaire and the health
utilities index: an exploratory analysis using survivors of childhood cancer.
AB - Mutual concurrent validity of 2 generic measures of health-related quality of
life (HRQL), the Child Health Questionnaire (CHQ) and the Health Utilities Index
Mark 2 (HUI2) and HUI3, was assessed. Data were from 3 centers participating in a
Canadian multi-center retrospective cohort study currently in progress to assess
psycho-social and physical late effects in children surviving >/=5 years after
cancer diagnosis between 1981 and 1990. Exploratory results are from 244 parent
reports on HRQL in children <16 years old when studied. Spearman rank-order
correlations between sub-scale scores for the CHQ and single-attribute utility
scores for the corresponding attribute from the HUI2 and HUI3 were used. As
predicted, the correlation between CHQ bodily pain and HUI2 and HUI3 pain was
strong, 0.58 and 0.60, respectively, while correlations between CHQ physical
functioning and HUI2 mobility and HUI3 ambulation were moderate, both 0.45.
Correlations between CHQ mental health and HUI2 and HUI3 emotion were strong,
0.64 and 0.54, respectively, rather than moderate, as predicted. Both the CHQ
general health scale and the general health single item were moderately
correlated with the HUI2 and HUI3 global utility scores rather than weakly, as
predicted (CHQ general health scale and HUI2 and HUI3 global utility were 0.43
and 0.44, respectively; CHQ general health single item and HUI2 and HUI3 global
utility were 0. 38 and 0.42, respectively). The CHQ and HUI, which are based on
different methodologies (summative Likert scaling and utility analysis,
respectively), appear to capture similar constructs in childhood cancer
survivors.
PMID- 10679880
TI - Comparison of screening instruments for disability and emotional/behavioral
disorders with a generic measure of health-related quality of life in survivors
of childhood brain tumors.
AB - The sensory, motor, educational and emotional/behavioral outcomes in 32 survivors
of childhood brain tumors were evaluated by examination, interview,
questionnaires on emotion/behavior and the Health Utilities Index Mark 2 (HUI 2).
Thirty-eight percent had moderate/severe disability, and this was associated
closely with special educational provision. Pre- and peri-operative factors were
the commonest determinants of disability. Fifty percent had a high score on the
emotion/behavior questionnaires, suggesting a high risk of an emotional or
behavioral problem. The HUI 2 discriminated well between those survivors who had
and those who had not had special provision made for their education but poorly
between those with high and those with low scores on the emotion/behavior
questionnaires. Previous studies have found self-reported health-related quality
of life to be related more closely to emotional/behavioral sequelae than to
disability. Possible uses and limitations of the HUI 2 in this clinical context
are discussed.
PMID- 10679881
TI - Cross-cultural adaptation of a health status classification system in children
with cancer. First results of the French adaptation of the Health Utilities Index
Marks 2 and 3.
AB - Our objective was to adapt and validate the Health Utilities Index Mark 2 (HUI 2)
and HUI 3 health status classification systems self-report questionnaire in a
population of children with cancer, a group of 42 children already included in a
multi-centre database designed by the Group on Brain Tumors in Children of the
French Society for Pediatric Oncology. Children were recruited during a routine
consultation. Most of them had completed treatment. The version of the
questionnaire for French adults was adapted linguistically for children. Open
ended queries by children about the comprehensiveness of the questions and very
low non-response rates showed a good acceptability of the questionnaire. The main
psychometric properties of the HUI 2 and HUI 3 classification systems were
assessed in 3 groups of raters (child, parent, physician): construct validity was
tested against the rating of the child's health state on a Likert scale and
through comparison with clinical data, and internal consistency was determined
through multi-trait analysis. Weighted and unweighted kappa values were used to
measure the inter-rater agreement between the child's, parent's and physician's
assessment of the child's health state. The convergent validity was satisfactory,
with better results when the physician's assessment was used. The most affected
attributes were the expected ones (i.e., cognition, pain and emotion).
Disagreement was observed between the 3 raters, more often in the same direction:
taking the child's assessment as the reference, the parents tended to under
estimate the health status while physicians tended to over-estimate it.
PMID- 10679882
TI - Preliminary translation and cultural adaptation of Health Utilities Index
questionnaires for application in Argentina.
AB - Quality-of-life assessment is being used increasingly in clinical research. This
is true particularly in the case of survivors of cancer in childhood, where
improving survival rates have raised concern regarding the long-term effects of
medical cure. Health-status assessment and quality-of-life instruments have been
developed for the most part in the English language, thus necessitating their
translation and cultural adaptation for use in non-English-speaking countries.
Our purpose was to develop a set of Spanish-language questionnaires for
application with a population of children with cancer in a tertiary-care center
in Buenos Aires, Argentina. The Health Utilities Index (HUI), a conceptual
framework for assessing health status, was chosen for this study. Three distinct
questionnaires, based on the HUI, were used: a self-completed one for health
professionals and teachers (15Q) to report assessments of children and 2
interviewer-administered ones, for child survivors (42Q) to report assessments
about their own health status and parents (45Q) to report assessments about their
children's health status. The original translations and reviews were accomplished
with direct oversight by members of the HUI Group, to ensure conceptual
equivalence. The instruments were then tested in Buenos Aires by application to
staff of the hematology-oncology service, childhood cancer patients and the
parents of childhood cancer patients. Several modifications were made based on
these tests. We concluded that the translation and cultural adaptation of these
instruments was adequate for use with the groups tested in a pilot survey of
survivors of childhood cancer in Argentina.
PMID- 10679883
TI - Research triangulation to derive meaning-based quality-of-life theory: adolescent
resilience model and instrument development.
AB - We describe the triangulation of qualitative and quantitative research methods
used to develop and test the Adolescent Resilience Model (ARM). The differences
in meaning-based and function-based health-related quality of life (HRQL) are
discussed, and method triangulation is presented as a means of developing models
of HRQL that represent the perspectives of the adolescent and family. Qualitative
methods of phenomenology, simultaneous concept analysis, focus groups and
thematic analysis were used to generate the ARM. Quantitative instrumentation and
structural equation model development and testing were used to evaluate the ARM.
A decision-making process for combining qualitative and quantitative research, so
that both approaches are equally valued and used, is also presented. Int. J.
Cancer Suppl. 12:125-131, 1999.
PMID- 10679884
TI - Interpreting the meaningfulness of changes in health-related quality of life
scores: lessons from studies in adults.
AB - The measurement of health-related quality of life (HRQL) in adults with cancer
has proceeded more quickly than has similar measurement in children, so there may
be value in applying some methods used in adults to studies in children. An
example is a health-transition state instrument called the Subjective
Significance Questionnaire (SSQ). The SSQ asks patients to give their own
estimates of the degree to which their HRQL has changed with time and, thus,
provides a method for interpreting the meaningfulness of changes in scores as
derived from a general questionnaire, the EORTC QLQ-C30. The development of
similar health-transition instruments for children poses special challenges and
requires the development of appropriate methodology. It is suggested that, with
the use of cartoons and the answers of proxies, it should be feasible to assess
the meaningfulness of changes in HRQL over time in young children as well as in
adolescents. Int. J. Cancer Suppl. 12:132-137, 1999.
PMID- 10679885
TI - Feasibility of implementing health promotion interventions to improve health
related quality of life.
AB - Survivors of childhood cancer are a growing and vulnerable population. Cure rates
for pediatric cancers now exceed 60% and, by the year 2000, an estimated 1 of
every 1,000 young adults will be a cancer survivor. Because this population is at
increased risk for late medical and neoplastic complications that impact
adversely on health-related quality of life, it is important to investigate
methods to promote risk reduction by motivating survivors to practice health
promoting behaviors. With this background, we initiated a prospective,
randomized, controlled feasibility study in which survivors attending a long-term
follow-up clinic were randomized to receive standard care or standard care plus
an educational intervention. Our objectives were to determine if the intervention
would improve the survivors' knowledge about their cancer treatment and risks of
late effects and increase their practice of health-protective behaviors. Since
July 1995, 272 of 318 families (86%) approached about the study agreed to
participate. Of these, 266 are evaluable for assessment of baseline knowledge and
health behaviors. Demographic features, baseline knowledge, health perceptions
and health behaviors did not differ among randomized groups. Assessment of the
intervention's efficacy at changing health behaviors of survivors randomized to
the intervention group will be available when the 1-year follow-up evaluations
are completed for the study cohort. Our preliminary experience with this pilot
study supports the feasibility of educational intervention research in a
specialty clinic dedicated to monitoring long-term childhood cancer survivors.
Int. J. Cancer Suppl. 12:138-142, 1999.
PMID- 10679886
TI - Measuring health-related quality of life in childhood cancer: lessons from the
workshop (discussion).
PMID- 10679887
TI - Measuring health-related quality of life in pediatric oncology patients: a brief
commentary on the state of the art of measurement and application (discussion).
PMID- 10679888
TI - Obstacles and opportunities for the use of health-related quality-of-life
assessment in pediatric cancer clinical trials (discussion).
PMID- 10679889
TI - A postscript to the international workshop on assessing health-related quality of
life in children with cancer.
PMID- 10679890
TI - Are there two distinct research strategies for developing biologically active
molecules: rational design and empirical selection?
PMID- 10679891
TI - Native-like cyclic peptide models of a viral antigenic site: finding a balance
between rigidity and flexibility.
AB - Antigenic site A of foot-and-mouth disease virus (serotype C) has been reproduced
by means of cyclic versions of peptide A15, YTASARGDLAHLTTT, corresponding to
residues 136-150 of envelope protein VP1. A structural basis for the design of
the cyclic peptides is provided by crystallographic data from complexes between
the Fab fragments of anti-site A monoclonal antibodies and A15, in which the
bound peptide is folded into a quasi-cyclic pattern. Head-to-tail cyclizations of
A15 do not provide peptides of superior antigenicity. Internal disulfide
cyclization, however, leads to analogs which are recognized as one to two orders
of magnitude better than linear A15 in both ELISA and biosensor experiments. CD
and NMR studies show that the best antigen, CTASARGDLAHLTT-Ahx-C (disulfide), is
very insensitive to environment-induced conformational change, suggesting that
cyclization helps to stabilize a bioactive-like structure.
PMID- 10679892
TI - Membrane-perturbing activity of Viperidae myotoxins: an electrostatic surface
potential approach to a puzzling problem.
AB - Phospholipase-like myotoxins are a class of proteins present in Viperidae venom.
Despite the high level of amino acid and structural homology with soluble
phospholipases A(2), myotoxins are devoid of enzymatic activity and share
cytolytic activity by means of a totally unknown mechanism involving the lipid
bilayer perturbation. The distribution of electrostatic surface potentials of
four myotoxins and seven phospholipases A(2) has been compared. The charge
distribution is similar in all active non-cytolytic phospholipases with a
strongly positive side corresponding to the domain interacting with the micellar
substrate and with the opposite side negatively charged. In contrast, all
myotoxins examined are positively charged on both sides. Myotoxin III, the only
known example of a myotoxin sharing enzymatic activity, displays the same
electrostatic surface potential as other related toxins. Using liposomes made
with non-hydrolysable phospholipids, we demonstrate that myotoxin III perturbs
the lipid bilayer like other myotoxins. Based on these results, a molecular model
for myotoxin-membrane perturbing activity is proposed. In this model, potential
double-face binding of myotoxic phospholipases A(2) to lipid surfaces could
trigger a lipid bilayer destabilization and could generate a stable fusion pore,
probably because of the presence of hydrophobic moieties that flank the cationic
sites.
PMID- 10679893
TI - Application of surface plasmon resonance for analysis of protein-protein
interactions in the G protein-mediated signal transduction pathway.
AB - Hundreds of extracellular stimuli are received by cells via the pathways
consisting of three basic components: cell-surface receptors, heterotrimeric G
proteins, and intracellular effector enzymes or ion channels. A number of
additional molecules, including G protein-coupled receptor kinases (GRKs),
phosducin and Ca(2+)-binding proteins modulate signal transduction through these
cascades. Understanding how these universal pathways work requires a detailed
analysis of the interactions between these proteins. The recently emerged
technology of surface plasmon resonance (SPR) can study protein-protein
interactions by measuring not only the equilibrium binding constants, but also
the association and dissociation rates. This article reviews experimental design
used by researchers to analyze different components of the G protein pathway by
SPR and focuses on the insights this technique provides regarding the kinetics,
structure-function aspects and regulation of specific molecular events in the
cascade.
PMID- 10679894
TI - Conformations of nicotinamide adenine dinucleotide (NAD(+)) in various
environments.
AB - Enzymes bind NAD(+) in extended conformations and yet NAD(+) exists in aqueous
solution as a compact, folded molecule. Thus, NAD(+) conformation is environment
dependent. In an attempt to investigate the effects of environmental changes on
the conformation of NAD(+), a series of molecular dynamics simulations in
different solvents was performed. The solvents investigated (water, DMSO,
methanol and chloroform) represented changes in relative permittivity and
hydrophobic character. The simulations predicted folded conformations of NAD(+)
to be more stable in water, DMSO and methanol. In contrast, extended
conformations of NAD(+) were observed to be more stable in chloroform.
Furthermore, the extended conformations observed in chloroform were similar to
conformations of NAD(+) bound to enzymes. In particular, a large separation
between the aromatic rings and a strong interaction between the pyrophosphate and
nicotinamide groups were observed. The implications of these observations for the
recognition of NAD(+) by enzymes is discussed. It is argued that a hydrophobic
environment is important for stabilizing unfolded conformations of NAD(+).
PMID- 10679895
TI - Crystal structure of asparagine 233-replaced cyclodextrin glucanotransferase from
alkalophilic Bacillus sp. 1011 determined at 1.9 A resolution.
AB - The crystal structure of asparagine 233-replaced cyclodextrin glucanotransferase
from alkalophilic Bacillus sp. 1011 was determined at 1.9 A resolution. While the
wild-type CGTase from the same bacterium produces a mixture of mainly alpha-,
beta- and gamma-cyclodextrins, catalyzing the conversion of starch into cyclic or
linear alpha-1,4-linked glucopyranosyl chains, site-directed mutation of
histidine-233 to asparagine changed the nature of the enzyme such that it no
longer produced alpha-cyclodextrin. This is a promising step towards an
industrial requirement, i.e. unification of the products from the enzyme. Two
independent molecules were found in an asymmetric unit, related by pseudo two
fold symmetry. The backbone structure of the mutant enzyme was very similar to
that of the wild-type CGTase except that the position of the side chain of
residue 233 was such that it is not likely to participate in the catalytic
function. The active site cleft was filled with several water molecules, forming
a hydrogen bond network with various polar side chains of the enzyme, but not
with asparagine-233. The differences in hydrogen bonds in the neighborhood of
asparagine-233, maintaining the architecture of the active site cleft, seem to be
responsible for the change in molecular recognition of both substrate and product
of the mutant CGTase.
PMID- 10679896
TI - The conformations of locked nucleic acids (LNA).
AB - We have used 2D NMR spectroscopy to study the sugar conformations of
oligonucleotides containing a conformationally restricted nucleotide (LNA) with a
2'-O, 4'-C-methylene bridge. We have investigated a modified 9-mer single
stranded oligonucleotide as well as three 9- and 10-mer modified oligonucleotides
hybridized to unmodified DNA. The single-stranded LNA contained three
modifications whereas the duplexes contained one, three and four modifications,
respectively. The LNA:DNA duplexes have normal Watson-Crick base-pairing with all
the nucleotides in anti-conformation. By use of selective DQF-COSY spectra we
determined the ratio between the N-type (C3'-endo) and S-type (C2'-endo) sugar
conformations of the nucleotides. In contrast to the corresponding single
stranded DNA (ssDNA), we found that the sugar conformations of the single
stranded LNA oligonucleotide (ssLNA) cannot be described by a major S-type
conformer of all the nucleotides. The nucleotides flanking an LNA nucleotide have
sugar conformations with a significant population of the N-type conformer.
Similarly, the sugar conformations of the nucleotides in the LNA:DNA duplexes
flanking a modification were also shown to have significant contributions from
the N-type conformation. In all cases, the sugar conformations of the nucleotides
in the complementary DNA strand in the duplex remain in the S-type conformation.
We found that the locked conformation of the LNA nucleotides both in ssLNA and in
the duplexes organize the phosphate backbone in such a way as to introduce higher
population of the N-type conformation. These conformational changes are
associated with an improved stacking of the nucleobases. Based on the results
reported herein, we propose that the exceptional stability of the LNA modified
duplexes is caused by a quenching of concerted local backbone motions
(preorganization) by the LNA nucleotides in ssLNA so as to decrease the entropy
loss on duplex formation combined with a more efficient stacking of the
nucleobases.
PMID- 10679897
TI - FDG PET evaluation of head and neck cancer: value of imaging the thorax.
AB - BACKGROUND: Patients with primary tumors of the head and neck have been reported
to have a high rate of synchronous primary tumors of the upper aerodigestive
tract. This study was performed to determine whether inclusion of the thorax in
the scan volume would be diagnostically useful for positron emission tomography
(PET) with [F-18] fluorodeoxy-D-glucose (FDG) in patients with primary tumors of
the head and neck. METHODS: FDG PET scans from the midcranium to the diaphragm
were obtained on 56 patients with a variety of head and neck tumors on initial
examination before definitive therapy. PET findings in the chest were correlated
with results of all other imaging studies, biopsy results, and clinical follow
up. RESULTS: In nine studies (16%), areas of increased FDG uptake in the chest
were seen and were judged to be tumors. Six of these probably were false-positive
results, although one of these six may have been unconfirmed true positives. Of
the three confirmed true-positive studies, two were obvious from other routine
studies. In only one case did the PET study reveal a significant lesion not found
by means of routine evaluation, resulting in a case-finding yield of 2%. If the
unconfirmed possible true-positive results are included, the case-finding yield
increases to 4%. CONCLUSIONS: No compelling indication was seen for including the
chest in PET studies of patients with head and neck cancer.
PMID- 10679898
TI - The fate of osseointegrated implants in patients following oral cancer surgery
and mandibular reconstruction.
AB - BACKGROUND: The feasibility of implant treatment in patients after oral ablative
tumor surgery and defect reconstruction has not yet been investigated in terms of
the requisite high standards of success assessment. A report on this topic must
address not only implant survival but implant health, bone response, soft tissue
health, failure pattern, and time of failure, as well. METHODS: From June 1990
through December 1997, 90 patients received 320 dental implants after oral tumor
resection and immediate soft tissue reconstruction. Included in the study were 45
patients with 162 implants loaded for at least 1 year. Regular follow-up for 6
years consisted of detailed medical history and evaluation of periodontal
parameters. Out of this population, 10 vascularized iliac bone grafts for
mandibular reconstruction containing loaded implants were selectively evaluated
for bone loss. RESULTS: The assessment of pocket probing depths, plaque
accumulation, bleeding disposition, implant mobility by means of the Periotest
method applied to the restoration type, horizontal and vertical (peri-implant)
bone loss according to x-ray findings, causes and time of implant loss, and
subjective statements offered results comparable to those found in healthy
subjects examined with periodontal success parameters. CONCLUSION: Prosthetic
restoration of patients after oral ablative tumor surgery followed by hard and
soft tissue reconstruction can be achieved with dental implants with similar long
term efficacy as found in healthy subjects adhering to internationally
established requirements.
PMID- 10679899
TI - Impact of tongue base and posterior pharyngeal wall biomechanics on pharyngeal
clearance in irradiated postsurgical oral and oropharyngeal cancer patients.
AB - BACKGROUND: Postsurgical oral and oropharyngeal cancer patients may experience
pharyngeal clearance problems after completion of postoperative radiotherapy.
METHODS: Swallowing was examined in six patients using videofluoroscopy for up to
1 year after surgery. Biomechanical analysis was used to mark movement of the
tongue base and posterior pharyngeal wall during swallowing. RESULTS: The
majority of patients experienced increased problems with pharyngeal clearance at
or after their 6 month posthealing evaluation, generally 18 to 22 weeks after
completion of radiotherapy. Pharyngeal residue was associated with a disruption
in either tongue base or posterior pharyngeal wall movement. CONCLUSIONS:
Increased fibrosis of the pharyngeal musculature after completion of radiotherapy
may have a negative impact on pharyngeal clearance in addition to any pharyngeal
clearance problems resulting from surgical resection. Tongue base to posterior
pharyngeal wall contact is essential but not sufficient for effective pharyngeal
clearance. Sufficient duration of tongue base to posterior pharyngeal wall
contact is also needed to provide adequate pharyngeal bolus driving pressure.
PMID- 10679900
TI - Reliability and validity of an observer-rated disfigurement scale for head and
neck cancer patients.
AB - BACKGROUND: Facial disfigurement is considered to be one of the most distressing
aspects of head and neck cancer and its treatment, but it has been the focus of
little systematic study. Existing studies have yielded conflicting results about
the psychosocial impact of disfigurement. No studies to date have examined
disfigurement using a valid and reliable observer-rated measure. The purpose of
the current study was to examine the validity (convergent and discriminant) and
the inter-rater reliability of a novel nine-point observer-rated disfigurement
scale. METHODS: The sample consisted of 74 ambulatory head and neck cancer
patients more than 6 months post treatment. Ratings of disfigurement were
assigned independently by surgical and nonsurgical raters. Validity was assessed
by comparing the association between disfigurement ratings and sociodemographic
and illness treatment variables. Reliability was assessed by examining the
concordance between the surgical and nonsurgical ratings. RESULTS: Disfigurement
ratings were not associated with several sociodemographic variables, supporting
the discriminant validity of the scale. Disfigurement was significantly related
to a diagnosis of oral cancer, a history of adjunctive radiation, the type of
surgical procedure performed, the degree of physical dysfunction, and the
presence of postoperative complications. Observer ratings of disfigurement were
significantly related to patient ratings of disfigurement. These findings support
the convergent validity of the disfigurement scale. Inter-rater reliability of
the scale was high (intraclass correlation coefficient =.91). CONCLUSION: The
study provides preliminary evidence for the validity and inter-rater reliability
of a novel nine point observer-rated disfigurement scale that may be useful in
evaluating the impact of disfigurement on quality of life in head and neck
cancer.
PMID- 10679901
TI - Experience with Barton button and peristomal breathing valve attachments for
hands-free tracheoesophageal speech.
AB - BACKGROUND: Tracheostoma breathing valves permit hands-free tracheoesophageal
(TE) speech production; however, few laryngectomees routinely use them because of
problems with attachment. METHODS: We retrospectively reviewed the charts of 45
TE speakers to determine the success rate and factors associated with successful
breathing valve use based on attachment. All patients attempted to use a
tracheostoma breathing valve with either a standard or customized peristomal
housing, or a standard or customized Barton button. Device selection was based on
inspection of the patient's neck and peristomal contour. Six to eight consecutive
hours of attachment defined success. RESULTS: Overall, 9% of subjects succeeded
with any peristomal attachment as compared to 68% with either a standard (57%) or
customized (85%) Barton button. Smooth stomal contour, a contiguous stomal lip,
and correct button length were important for successful Barton button use.
CONCLUSIONS: Standard or customized Barton buttons offer excellent alternatives
to peristomal housing attachments for hands-free TE speech in select patients.
PMID- 10679902
TI - Effects of arachidonic acid metabolites in a murine model of squamous cell
carcinoma.
AB - BACKGROUND: A murine model (C3H mice) of squamous cell carcinoma (SCCVII) has
been used to investigate the role of arachidonic acid (AA) metabolites in head
and neck cancer. Inhibition of tumor growth by cyclooxygenase (COX) and
lipoxygenase (LOX) inhibitors of AA metabolism has been associated with changes
in levels of AA metabolites in tumor tissues and inflammatory cell infiltrates.
To characterize this model further, the effects of exogenous AA metabolites on
tumor growth in vitro and in vivo were investigated. METHODS: Following
subcutaneous inoculation with SCCVII tumor cells, control (16 mice) and treatment
(24 mice) groups were injected with peritumoral vehicle or AA metabolite.
Peritumoral injections of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and 12
hydroxyeicosatetraenoic acid (12-HETE) were performed for 16-21 days, and final
excised tumor weights were measured. In vitro production of PGE2 and LTB4 was
assayed in 2-5 day cultures of SCCVII. Exogenous PGE2 effects on tumor cell
growth was assessed with the MTT assay in vitro. RESULTS: Tumor growth was
significantly inhibited (p =.03) following peritumoral injection of PGE2. Final
tumor weights were not affected by LTB4 or 12-HETE. Tumor inhibition by PGE2 was
associated with increased tumor tissue levels of LTB4 (p =.04). In vitro, SCCVII
produced minimal amounts of PGE2 and LTB4, and PGE2 had minimal effect on growth.
CONCLUSIONS: In this model, tumor inhibition by exogenous PGE2 is primarily
mediated by affecting host-tumor interactions, although there may be some direct
effect on tumor cells. Changes in tumor tissue levels of LTB4 following
peritumoral PGE2 administration may be attributable to negative feedback
inhibition of the COX pathway with shunting into the LOX pathway. SCCVII cells
are probably not a significant source of prostaglandins and leukotrienes in vivo.
These data provide insight into the mechanism of action of inhibitors of AA
metabolism on tumor growth.
PMID- 10679903
TI - Multicentricity in pharyngoesophageal tumors: argument for total
pharyngolaryngoesophagectomy and gastric transposition.
AB - BACKGROUND: Pharyngoesophageal tumors pose a challenge to surgical management,
and there is controversy in the literature as to the best procedure to be used.
Advantages and disadvantages are mentioned for total pharyngolaryngoesophagectomy
and gastric transposition (PLE>), free jejunal transplants, and free forearm
flaps. One of the arguments for PLE> is the persistence or subsequent
occurrence of multiple primaries in a field cancerization region. Multiple tumors
in the head and neck/esophagus/lung axis have been reported. However, despite
extensive investigation, there is little information on specific multicentricity
in patients treated with PLE> for pharyngolaryngoesophageal carcinomas.
METHODS: A clinicopathological study was undertaken in 35 consecutive patients
who underwent PLE> for pharyngoesophageal cancer to evaluate synchronicity,
multicentricity, and metachronicity. Only in situ and invasive carcinomas were
considered. The findings were compared with the reports in the literature.
RESULTS: Thirty-eight tumors were diagnosed preoperatively, with the main
indications for PLE> being tumors located in the esophagus or hypopharynx (32
patients) and larynx (three patients). After the surgical treatment, 21 patients
had single primaries (60%) and 14 (40%) had 25 multiple primaries in addition to
their main primaries (total of 60 tumors in the whole group). Synchronous,
previous metachronous and subsequent metachronous carcinomas occurred in 26%,
17%, and 8.5% of the instances, respectively. Twenty of the 25 multicentric
carcinomas were invasive (80%). Either the main primaries or the multicentric
carcinomas were located in the esophagus or hypopharynx (91.5% and 60%,
respectively). Other sites included the larynx, oropharynx, oral cavity, and
lung. CONCLUSION: The incidence of multicentric tumors in patients with
pharyngoesophageal carcinomas may favor total PLE> as the procedure of choice,
because it includes all the condemned upper pharyngolaryngoesophageal mucosa.
PMID- 10679904
TI - Squamous cell carcinoma of maxillary sinus.
AB - BACKGROUND: Medical records of 43 patients with histologically proved diagnosis
of squamous cell carcinoma who were treated between the years 1975 and 1994 at
the department of Otolaryngology Head Neck Surgery, VU Amsterdam were examined.
METHODS: Tumors were restaged according to UICC classification 1997. Thirty-eight
patients were treated for cure, nine were treated with chemotherapy followed by
external beam radiotherapy, and 28 patients were treated with surgery followed by
postoperative radiotherapy. No patient was lost to follow-up. Data with respect
to survival were analyzed. RESULTS: Eighty-three percent of the tumours were in
stage III or stage IV at the time of first presentation. Five-year survival after
surgery and postoperative radiotherapy for all patients was 64%. For stages II,
III, and IV it was 83%, 49%, and 37%, respectively. Cervical nodal metastases
were present in 4.1% at the time of presentation. Thirty-seven percent of the
patients survived 2 years after chemotherapy followed by radiotherapy.
CONCLUSIONS: Squamous cell carcinoma continues to be diagnosed late. Surgery
followed by radiotherapy remains the treatment of choice. Mandibulotomy should be
considered for better clearance of retromaxillary space in T3 -T4 tumors. The eye
should be preserved whenever it is oncologically safe to do so.
PMID- 10679905
TI - Diagnosis of superficial esophageal cancer and dysplasia using endoscopic
screening with a 2% lugol dye solution in patients with head and neck cancer.
AB - BACKGROUND: Head and neck cancer (HNC) has a high incidence in Brazil, with
cancer of the oral cavity being one of the five most common cancers among
Brazilians. Alcohol and tobacco consumption may contribute to synchronous or
metachronous HNC and esophageal cancer. The early detection of superficial
esophageal cancer and dysplasia in asymptomatic patients with HNC, after
successfully treating the primary cancer, may provide an effective cure. METHODS:
A prospective study involving 60 patients with HNC was carried out at the State
University of Campinas (UNICAMP) to screen for superficial esophageal cancer and
dysplasia using endoscopy and a 2% lugol dye solution followed by biopsy of the
suspicious areas. RESULTS: Five patients (8.3%) had superficial esophageal
cancer, which was diagnosed as intraepithelial carcinoma in three of them (5.0%).
In four patients, the superficial esophageal cancer was synchronous, and in one
it was metachronous to HNC. Five patients (8.3%) had dysplasias in the esophageal
epithelium (three were classified as mild and two as moderate). CONCLUSION: These
results demonstrate the value of endoscopic screening of the esophagus using
lugol dye in patients with HNC, particularly because superficial esophageal
cancer is extremely difficult to detect by conventional methods in asymptomatic
patients.
PMID- 10679906
TI - The performance of SF-36 health survey in patients with laryngeal cancer. Head
and Neck Cancer Italian Working Group.
AB - BACKGROUND: Interest in measuring health-related quality of life has increased
together with the awareness that such humanistic outcomes require valid and
reliable measures. Among the several generic questionnaires, the Short Form 36
Items Health Survey (SF-36) is recognized for its comprehensiveness, brevity, and
high standards of reliability and validity. It has been translated and validated
in several languages. METHODS: In the framework of a larger, prospective,
multicenter study aimed to produce and validate an Italian questionnaire tailored
to laryngeal cancer patients, the SF-36 was administered to a sample of well
characterized cases. It was, therefore, possible to test its characteristics in
terms of patients' acceptance, psychometric, and clinical validity. RESULTS:
Overall, findings show that in this sample of 165 consecutive patients with
laryngeal cancer at various stage of disease, the SF-36 performance was very
good. The patients' acceptance was satisfactory: all patients completed the
questionnaire. All the questionnaire scales met the standards suggested in terms
of grouping and scaling assumptions. The internal reliability coefficients
actually replicate the satisfactory findings reported for the original SF-36. In
terms of capability of the questionnaire scales to discriminate between groups
expected to differ in a given health concept in relation to clinical variables,
the results were also good. CONCLUSIONS: This study showed that SF-36 was well
accepted by patients and was able to detect the impact of different treatment
approaches on health- related quality of life. It is likely that the sensitivity
and the precision of the SF-36 can be further improved by integrating brief
questionnaire modules specific for laryngeal clinical issues.
PMID- 10679907
TI - Primary melanocytic schwannoma of cervical sympathetic chain.
AB - BACKGROUND: Primary melanocytic schwannoma arising from the cervical sympathetic
chain is a rare pigmented nerve sheath tumor. Two cases are presented from an
academic medical center. Patients and Methods Patients were initially seen with
an enlarging neck mass associated with sympathetic nervous system dysfunction.
Radiography demonstrated a mass located posterior to the carotid sheath. Primary
therapy consisted of surgical excision and postoperative radiation therapy.
RESULTS: The tumors were found to be melanocytic schwannomas arising from the
cervical sympathetic chain. The pathologic characteristics of this neoplasm are
reviewed. One patient remained disease free for 12 years after treatment, whereas
1 patient died as a result of local recurrence and distant metastases.
CONCLUSIONS: Melanocytic schwannoma of the cervical sympathetic chain is a rare
nerve sheath tumor of the head and neck that may be misdiagnosed as malignant
melanoma. The clinical behavior of this neoplasm is variable. Preoperative
neurologic findings, anatomic location, electron microscopy, and
immunohistochemistry findings help to establish the diagnosis, and electron
microscopy may have a role in distinguishing between benign and malignant
lesions. Complete surgical excision is the treatment of choice.
PMID- 10679908
TI - Expression of basic fibroblast growth factor protein and its down-regulation by
interferons in head and neck cancer.
AB - BACKGROUND: Angiogenesis is crucial for tumor growth and metastasis. In several
tumors, microvascular density has been shown to correlate with metastasis and
aggressiveness. Basic fibroblast growth factor (bFGF) has potent angiogenic
activity and has been identified in a wide variety of malignancies including head
and neck squamous cell carcinomas (HNSCC). Material and Methods Frozen sections
of 50 HNSCC were immunostained for von Willebrand factor and bFGF. Microvessels
were counted by light microscopy; bFGF expression was studied at the light and
electron microscopic level. Laryngeal cancer cell line HlaC79 was incubated with
interferon (IFN) alpha and beta. bFGF quantification was performed by ELISA, and
antiproliferative effects were determined by BrdU assay. RESULTS: The mean number
of blood vessels (77.5 +/- 23.7) is significantly increased in HNSCC compared
with controls (17.1 +/- 5.9). bFGF protein expression was detected in all HNSCC
but not in control tissue. An correlation between bFGF expression and mean number
of microvessels was found (p <.001). However, no correlation between bFGF
expression and the main clinicopathologic features was shown. The long-term
exposure (144 hr) of HNSCC cells to noncytostatic concentrations of IFN alpha and
beta (>10 U/mL) down-regulated the protein production of bFGF. CONCLUSION: bFGF
expression and angiogenesis are enhanced in HNSCC. The higher microvessel density
in HNSCC with strong bFGF expression supports the importance of bFGF for tumor
angiogenesis. IFN alpha and beta treatment leads to a down-regulation of bFGF
expression independent of their antiproliferative effects, suggesting that IFN
treatment might result in a reduction of angiogenesis in HNSCC.
PMID- 10679909
TI - Carcinoma of the dorsum of the tongue.
AB - BACKGROUND: Squamous cell carcinoma (SCC) of the anterior two thirds of the
tongue is the second most common oral cancer, with the lateral border being the
most common location. Squamous cell carcinoma of the dorsum of the tongue is
exceedingly rare and has been described in the past as a myth or misdiagnosis.
The clinical diagnosis of SCC on the dorsum of the tongue is difficult because it
may be mimicked by a wide variety of benign and premalignant lesions, including
granular cell myoblastoma, erosive lichen planus, medial rhomboid glossitis, and
amyloidosis. In this study we re-evaluate the entity of SCC of the dorsum of the
tongue. METHODS: We reviewed 5 large series of carcinoma of the tongue, which
include accurate documentation of the topographic location of the carcinoma. We
also describe 5 cases of SCC of the dorsum of the tongue from our own series of
99 patients with carcinoma of the tongue. RESULTS: In all 6 series, carcinoma of
the dorsum of the tongue was present in 3 to 5% of the carcinomas of the tongue.
CONCLUSION: Although rare, SCC of the dorsum of the tongue exists and may be
mimicked by benign conditions, thus SCC should be suspected when diagnosing
lesions of this area of the tongue.
PMID- 10679910
TI - Identification of novel regions of allelic loss from a genomewide scan of
esophageal squamous-cell carcinoma in a high-risk Chinese population.
AB - Esophageal cancer is one of the most common fatal cancers worldwide. Deletions of
genomic regions are thought to be important in esophageal carcinogenesis. We
conducted a genomewide scan for regions of allelic loss using microdissected DNA
from 11 esophageal squamous-cell carcinoma patients with a family history of
upper gastrointestinal tract cancer from a high-risk region in north central
China. Allelic patterns of 366 fluorescently labeled microsatellite markers
distributed at 10-cM intervals over the 22 autosomal chromosomes were examined.
We identified 14 regions with very high frequency (>/= 75%) loss of
heterozygosity (LOH), including broad regions encompassing whole chromosome arms
(on 3p, 5q, 9p, 9q, and 13q), regions of intermediate size (on 2q, 4p, 11p, and
15q), and more discrete regions identified by very high frequency LOH for a
single marker (on 4q, 6q, 8p, 14q, and 17p). Among these 14 regions were 7 not
previously described in esophageal squamous-cell carcinoma as having very high
frequency LOH (on 2q, 4p, 4q, 6q, 8p, 14q, and 15q). The very high frequency LOH
regions identified here may point to major susceptibility genes, including
potential tumor suppressor genes and inherited gene loci, which will assist in
understanding the molecular events involved in esophageal carcinogenesis and may
help in the development of markers for genetic susceptibility testing and
screening for the early detection of this cancer. Genes Chromosomes Cancer 27:217
228, 2000. Published 2000 Wiley-Liss, Inc.
PMID- 10679911
TI - Identification of breakpoint cluster regions at 1p36.3 and 3q21 in hematologic
malignancies with t(1;3)(p36;q21).
AB - The reciprocal translocation t(1;3)(p36;q21) is associated with myelodysplastic
syndromes (MDSs) and acute myeloid leukemia (AML) characterized by trilineage
dysplasia, in particular dysmegakaryocytopoiesis, and a poor prognosis. As yet no
molecular genetic analyses of the t(1;3) have been reported. In four patients
with t(1;3), all of whom had AML-M4, which evolved from MDS, the breakpoints at
3q21 clustered within a 60-kb region centromeric to the breakpoint of the
inv(3)(q21q26), whereas the breakpoints at 1p36 clustered within a 90-kb region
at 1p36.3. The presence of novel clusters in both the 3q21 and 1p36 breakpoints
(BCRs) suggests a common, underlying molecular mechanism for the development of
t(1;3)-positive MDS/AML. The Ribophorin I (RPN1) gene close to the BCR at 3q21
was highly expressed without gross structural changes, whereas the GR6 gene
located within the BCR at 3q21 was not expressed. No other highly expressed genes
were isolated in a 150-kb region at 3q21. Thus, it is likely that a gene at
1p36.3 is activated by the translocation of the 3q21 region or a gene important
for transformation lies on 3q21, outside the 150-kb region. Further
characterization of the BCRs at 1p36.3 and 3q21 should provide important insights
into the molecular genetic mechanisms involved in the genesis of t(1;3)-positive
MDS/AML. Genes Chromosomes Cancer 27:229-238, 2000.
PMID- 10679912
TI - Genomic FHIT analysis in RER+ and RER- adenocarcinomas of the pancreas.
AB - Alterations of the candidate tumor suppressor gene FHIT have been reported in
multiple tumor types, including pancreatic carcinoma. The mechanism of FHIT
genomic inactivation is unusual, most frequently occurring by homozygous
deletion, whereas only rare cases have missense mutations. Altered (shortened)
transcripts and reduced protein expression are reported, but a genetic basis for
these is often inapparent. We studied FHIT genomic alterations of pancreatic
carcinomas. Loss of heterozygosity (LOH) was found in 41% of 93 carcinomas
without microsatellite instability (RER(-)), but no mutations were found by
genomic sequencing. Homozygous deletions inside the FRA3B fragile site were found
in four RER(-) tumors, but only two affected the FHIT coding region. In contrast,
FHIT alterations were found in the three RER(+) pancreatic carcinomas screened;
two had FHIT homozygous deletions affecting exon 5 and the third had a
heterozygous missense mutation (H76N). The excess occurrence of homozygous
deletions at this site in RER(+) pancreatic cancers is statistically significant
(P < 0.01). Since homozygous deletions have not previously been reported in
RER(+) carcinomas at any genomic site, an extremely high rate of site-specific
deletion must exist within the FRA3B-related FHIT gene. Consequently, the paucity
of documented inactivating point mutations cannot be used to judge the presence
or absence of putative FHIT-related selective pressures that act during
tumorigenesis of RER(-) neoplasia. Nonetheless, the identification of a
heterozygous mutation as the sole sequence abnormality might raise doubt as to
whether strong selective pressures are afforded by FHIT genomic inactivation in
this tumor type. Genes Chromosomes Cancer 27:239-243, 2000.
PMID- 10679913
TI - Allelotyping of anaplastic thyroid carcinoma: frequent allelic losses on 1q, 9p,
11, 17, 19p, and 22q.
AB - Little is known about the genetic mechanisms behind the genesis of anaplastic
thyroid carcinoma. This is among the most virulent of all human malignancies, and
it is believed to result most often from transformation of differentiated thyroid
carcinomas of the papillary type. So far, TP53 and beta-catenin mutations are the
only genetic alterations that have been implicated in its pathogenesis. To
identify loci of other potential tumor suppressor genes, we carried out a genome
wide allelotyping study using 39 microsatellite markers representing all
nonacrocentric autosomal arms, in a panel of 21 anaplastic thyroid carcinomas.
Frequent allelic losses were identified in 1q (40%), 9p (58%), 11p (33%), 11q
(33%), 17p (44%), 17q (43%), 19p (36%), and 22q (38%). Deletion mapping of
chromosome arms with the most frequent allelic losses (frequencies above 40%)
localized the commonly deleted region to 1q31-42, 9p21-22, 17p12-ter, and 17q21.1
22. The mean frequency of loss of heterozygosity on all arms tested was 20%, and
the mean fractional allelic loss among the cancers examined was 0.20. These
findings defined a sharp distinction between anaplastic thyroid carcinomas and
papillary thyroid carcinomas, because the latter do not tend to show losses at
the same loci. Frequent allelic losses at multiple loci may implicate chromosomal
instability as an important factor in the development of anaplastic thyroid
carcinomas. Genes Chromosomes Cancer 27:244-251, 2000.
PMID- 10679914
TI - Genetic and phenotypic changes associated with the acquisition of tumorigenicity
in human bladder cancer.
AB - There has been a general lack of human paired cell lines that both reproduce the
in vivo spectrum of tumor progression of bladder cancer and have some of the
genetic changes associated with progression in human tumor tissue. T24, a cell
line established from an invasive human transitional cell carcinoma (TCC) of the
bladder, has been used extensively in bladder cancer research. However, a
significant limitation of this cell line is its lack of tumorigenicity when
injected into immunocompromised mice. This characteristic was used to our
advantage as we sought to characterize T24T, a highly tumorigenic variant that
could then be used to elucidate the genes responsible for human bladder tumor
progression. In culture, T24T has a faster doubling time, reaches a higher cell
density in monolayer culture, and is more motile than T24 at higher cell
densities. T24T is able to form colonies in soft agar, whereas T24 is not, and
expresses HRAS, a gene associated with increased aggressiveness in human TCC, at
higher levels than T24. Most importantly, T24T forms solid tumors when injected
subcutaneously in SCID mice both with and without Matrigel (Sigma, St. Louis,
MO), whereas T24 does not. Cytogenetically, the 2 cell lines contain at least 5
shared structural anomalies, as determined by detailed karyotyping.
Interestingly, T24T has acquired 4 new structural changes, 3 of which
[add(10)(p12), i(10)(q10), -15] have been observed in loss of heterozygosity
(LOH) studies of tumor progression in human TCC. It appears that the T24/T24T
model may be an excellent tool for the study of human TCC progression because of
its relationship with known karyotypic changes associated with human bladder
cancer progression. We are currently taking advantage of these paired cell lines
to identify genes involved in human TCC progression. Genes Chromosomes Cancer
27:252-263, 2000.
PMID- 10679915
TI - MLL-CBP fusion transcript in a therapy-related acute myeloid leukemia with the
t(11;16)(q23;p13) which developed in an acute lymphoblastic leukemia patient with
Fanconi anemia.
AB - We describe a boy with Fanconi anemia (FA) who developed acute lymphoblastic
leukemia (ALL) (FAB-LI) followed by acute myeloid leukemia (AML) (FAB-M5) at
relapse. The patient was diagnosed with early pre-B-cell ALL without preceding
aplastic anemia and was treated with ALL-oriented chemotherapy which included
doxorubicin (a total dose of 140 mg/m(2) administered), which is a topoisomerase
II inhibitor. Complete remission was obtained, but after 38 weeks AML developed.
The karyotype of ALL cells at diagnosis showed 46,XY, and that of AML cells at
relapse was 46,XY, t(11;16)(q23;p13). An MLL gene rearrangement and MLL-CBP
chimeric mRNA were found in AML, but not in ALL. A diagnosis of FA was confirmed
by an increased number of chromosomal breaks and rearrangements in peripheral
blood lymphocytes cultured with mitogen in the presence of mitomycin C. We
conclude that this FA patient developed ALL followed by a therapy-related
t(11;16)-AML resulting in an MLL-CBP fusion. Further examination of such patients
would shed light on leukemogenesis in FA patients. Genes Chromosomes Cancer
27:264-269, 2000.
PMID- 10679916
TI - Modification in the inherent mode of allelic replication in lymphocytes of
patients suffering from renal cell carcinoma: a novel genetic alteration
associated with malignancy.
AB - Using fluorescence in situ hybridization (FISH) to interphase nuclei, we examined
the replication timing of 1 allele relative to its counterpart in PHA-stimulated
peripheral blood lymphocytes of normal subjects and patients suffering from a
solid tumor (renal cell carcinoma). In the FISH assay, an unreplicated DNA
sequence is identified by a single dot-like hybridization signal, whereas a
replicated region gives rise to a duplicated, bipartite signal. Accordingly,
lymphocytes of normal individuals show 2 patterns of allelic replication: (i)
synchronized replication of allelic counterparts, as exemplified by the
biallelically expressed loci TP53 and D21S55; and (ii) non-synchronized
replication of allelic partners, as exemplified by the early and late replicating
alleles of GABRB3, an imprinted locus subjected to monoallelic expression.
However, when present in lymphocytes of the cancer patients, all 3 loci change
their replication mode: alleles of TP53 and D21S55 become asynchronous, whereas
the early replicating allele of GABRB3 delays replication, leading to relaxation
in the imprinted mode of replication. Based on the tight relationship between
temporal order of allelic replication and allelic mode of expression, the
modified order of allelic replication observed in nonmalignant cells of
individuals diagnosed with cancer represents a novel genetic alteration
associated with malignancy. This alteration detected by simple cytogenetic means,
applied to peripheral blood lymphocytes, offers a potential test for cancer
identification. Genes Chromosomes Cancer 27:270-277, 2000.
PMID- 10679917
TI - Non-random involvement of chromosome 13 in patients with persistent or relapsed
disease after bone-marrow transplantation for chronic myeloid leukemia.
AB - Chronic myeloid leukemia (CML) patients with persistent or relapsed disease
following bone-marrow transplantation (BMT) usually show both clonal and non
clonal cytogenetic changes in addition to the Philadelphia (Ph) translocation.
These changes are presumably due to conditioning prior to transplantation and are
generally not thought to be of clinical significance. We have examined the
additional cytogenetic changes found in Ph+ve cells after BMT in 47 CML patients.
Forty patients showed clonal changes. The involvement of each chromosome was
compared statistically with expected values assuming that further chromosome
changes are random and related to chromosome size. In clones that comprised 50%
or more of the Ph+ve metaphases, chromosome 13 was involved in 12 of 22 clones
(55%); this was highly significant when compared with the theoretical expected
value of 3.2 (14.5%) (P < 0.001). The chromosome 13 rearrangements comprised both
translocations and deletions. By means of FISH with a panel of 13q YAC clones,
the breakpoints in 6 of these patients were investigated, but no common site of
translocation was identified. The YAC panel was then used on material from 6
patients with chromosomal deletions. A common region of deletion was identified
at 13q12-14, suggesting the presence of one or more tumor suppressor genes. We
conclude that chromosome 13 deletions are non-randomly overrepresented in Ph+ve
metaphases following BMT for CML. Genes Chromosomes Cancer 27:278-284, 2000.
PMID- 10679918
TI - t(11;14)-positive mantle cell lymphomas exhibit complex karyotypes and share
similarities with B-cell chronic lymphocytic leukemia.
AB - Until now, few data on additional chromosomal aberrations in t(11;14)-positive
mantle cell lymphomas (MCLs) have been published. We analyzed 39 t(11;14)
positive MCLs by either comparative genomic hybridization (CGH; n = 8),
fluorescence in situ hybridization (FISH) with a set of DNA probes detecting the
most frequent aberrations in B-cell neoplasms (n = 12), or both techniques (n =
19). The t(11;14) was present in all cases. In 37 of 39 cases, chromosomal
imbalances were found. In 27 cases, complex karyotypes, i.e., >/= 3 aberrations,
were identified. The most frequent aberrations were losses of 13q14-21 or 13q32
34 (27 cases), 9p21 (16 cases), and 11q22-23 (12 cases) and gains of 3q26-29 (19
cases), 8q22-24 (11 cases), and 18q21-22 (9 cases). In 26% of cases (7 of 27)
analyzed by CGH, a total of 10 high-level DNA amplifications were identified.
Although in comparison with B-cell chronic lymphopcytic leukemia (B-CLL) MCL is
characterized by a much higher complexity of chromosomal aberrations, there are
striking similarities: 13q14 deletions were identified in more than 50% of both
MCL and B-CLL cases. In contrast, in our CGH database containing 293 B-cell
lymphomas, this aberration was found in only 11% of other nodal lymphomas. Even
more strikingly, 11q deletions, which are present in 20%-30 % of MCL and B-CLL,
were found very rarely in other nodal B-cell lymphomas (CGH: 1 of 208 cases;
FISH: 1 of 69 cases). These data show that MCL is characterized by specific
secondary aberrations and that there may be similarities in the pathogenesis of
MCL and B-CLL. Genes Chromosomes Cancer 27:285-294, 2000.
PMID- 10679919
TI - A sporadic breast tumor with a somatically acquired complex genomic rearrangement
in BRCA1.
AB - Germ-line mutations in BRCA1 cause a substantial proportion of inherited breast
cancer, and most result in inactivated BRCA1 proteins upon translation. Tumours
developing in BRCA1 mutation carriers generally show loss of the wild-type
allele. However, acquired inactivating mutations in BRCA1 in non-inherited breast
tumours showing loss of heterozygosity at the gene locus have not been detected
so far. Here we provide evidence that such mutations can be detected in a small
proportion of breast tumours. Prompted by recent reports of Alu-mediated large
genomic rearrangements in BRCA1, we have investigated whether such rearrangements
might occur in sporadic breast cancer as well and have been missed thus far by
traditional PCR-based mutation screening technology. To this end, we performed
Southern blot analysis of 81 apparently sporadic breast tumours using probes
covering exons 6-24 and 3 restriction enzymes. We identified 1 case with an
acquired rearrangement (1.2%), indicating that BRCA1 inactivation through changes
in the primary genomic sequence of the gene is uncommon in breast cancer. Genes
Chromosomes Cancer 27:295-302, 2000.
PMID- 10679920
TI - Novel gene fusion of COX6C at 8q22-23 to HMGIC at 12q15 in a uterine leiomyoma.
AB - Cytogenetic analyses have shown that aberrations involving 12q13-15 are frequent
chromosomal changes in a variety of human benign mesenchymal tumors, e.g.,
pleomorphic adenomas of the parotid gland, pulmonary chondroid hamartomas,
lipomas, and uterine leiomyomas. Recently, the high-mobility group protein gene
HMGIC was identified as the target gene affected by the 12q13-15 aberrations.
Using 3' rapid amplification of cDNA ends experiments, we isolated novel ectopic
sequences fused to HMGIC in a uterine leiomyoma. Cloning of the fusion cDNA
identified the human cytochrome c oxidase subunit VIc (COX6C) gene on 8q22-23 as
the fusion partner of HMGIC. Nucleotide sequences of the fusion transcript
revealed that the first 3 exons of the HMGIC gene, encoding the 3 DNA binding
domains, was fused to the exon 2 of the COX6C gene. The identification of a gene
rearrangement suggests a role for HMGIC in tumorigenesis of uterine leiomyoma and
suggests a possible involvement of HMGIC in mesenchymal differentiation. Genes
Chromosomes Cancer 27:303-307, 2000.
PMID- 10679921
TI - Two regions of homozygous deletion clusters at chromosome band 9p21 in human lung
cancer.
AB - We examined 149 lung cancer cell lines for homozygous deletions using 24 DNA
markers, which were mapped and ordered in chromosome band 9p21, to define the
target regions for 9p21 deletions in human lung cancer. Homozygous deletions were
detected in 39 (26%) cell lines and clustered at 2 independent regions. One was
the region containing the p16/CDKN2A tumor suppressor gene, and this region was
deleted in 32 (21%) cell lines. The other was the region containing D9S171, which
is the locus approximately 3 Mb proximal to the CDKN2A locus. This region,
designated as the D9S171 region, was deleted in 18 (12%) cell lines. Seven of the
18 cell lines had identical minimum deletions of a 17,036 bp sequence located 20
kb distal to the D9S171 locus. However, such a deletion was also observed in the
corresponding B-lymphoblastoid cell line from 1 of the 7 cell lines and in 5
(16%) of 32 noncancerous tissues, suggesting that the deletion was a genetic
polymorphism. By considering this polymorphism, 11 (7%) cell lines still had
deletions at the D9S171 region. Two NSCLC cell lines showed deletions at the
D9S171 region and retentions of the CDKN2A locus. Furthermore, an NSCLC cell line
showed discontinuous deletions including either the CDKN2A or D9S171 locus.
Therefore, the region surrounding the D9S171 locus was defined as another target
region for the 9p21 deletions. It is possible that unknown tumor suppressor
gene(s) are present in this chromosomal region. Genes Chromosomes Cancer 27:308
318, 2000.
PMID- 10679922
TI - Molecular analysis of the candidate tumor suppressor gene ING1 in human head and
neck tumors with 13q deletions.
AB - The candidate tumor-suppressor gene ING1 encodes p33(ING1), a nuclear protein
which physically interacts with TP53. It has been shown that p33(ING1) acts in
the same biochemical pathway as TP53, leading to cell growth inhibition.
Interestingly, a rearrangement of the ING1 gene was found in a neuroblastoma cell
line, supporting its involvement in tumor development. Because ING1 resides on
the long arm of chromosome 13 (13q34) (a region frequently deleted in many tumor
types), we sought to characterize its role in head and neck squamous-cell
carcinoma (HNSCC). We first analyzed 44 primary tumors for loss of heterozygosity
(LOH) at 13q, using four widely spaced microsatellite markers (13q14, 13q14.3
q22, 13q22, and 13q34). Twenty (48%) of the tumor samples showed LOH in all of
the informative markers tested, including D13S1315 at 13q34. Two of the tumors
displayed partial losses restricted to one marker (D13S118 at 13q14 in tumor
1164, and D13S135 at 13q14.3-q22 in tumor 1398). We then determined the genomic
structure of the ING1 gene and sequenced the entire coding region in 20 primary
tumors showing 13q LOH and in five head and neck cancer cell lines. A single
germline polymorphism was detected in 10 of the tumors analyzed (T to C change)
located 110 nucleotides upstream of the starting methionine. No somatic mutations
were found in any of the samples, suggesting that ING1 is not a tumor suppressor
gene target in head and neck cancer. Genes Chromosomes Cancer 27:319-322, 2000.
PMID- 10679923
TI - Recurrent allelic deletions of chromosome arms 15q and 16q in human small cell
lung carcinomas.
AB - The genetic lesions that lead to the development of small cell lung carcinoma
(SCLC) remain incompletely defined. To identify recurrent allelic deletions in
specific chromosomal regions that could serve as markers for tumor suppressor
gene (TSG) inactivation in SCLC, we performed a comprehensive allelotype analysis
of all 39 nonacrocentric autosomal arms. Alterations in 158 polymorphic
microsatellite alleles were examined in 24 pairs of human SCLC tumor and normal
control DNA samples. A total of 2,107 informative reactions were analyzed. This
analysis revealed allelic losses of 100% on chromosome arm 3p, >85% loss within
chromosome arms 13q and 17p, and >70% loss within chromosome arms 4q, 5q, 15q,
and 16q. The allelic deletions on chromosome arms 15q and 16q have not been
defined previously for SCLC and are candidate regions to harbor novel TSGs. Genes
Chromosomes Cancer 27:323-331, 2000.
PMID- 10679924
TI - PRK, a cell cycle gene localized to 8p21, is downregulated in head and neck
cancer.
AB - The human PRK gene encodes a protein serine/threonine kinase of the polo family
and plays an essential role in regulating meiosis and mitosis. We have previously
shown that PRK expression is downregulated in a significant fraction of lung
carcinomas. Our current studies reveal that PRK mRNA expression is downregulated
in a majority (26 out of 35 patients) of primary head and neck squamous-cell
carcinomas (HNSCC) compared with adjacent uninvolved tissues from the same
patients, regardless of stage. In addition, PRK transcripts were undetectable in
one of the two HNSCC cell lines analyzed. Ectopic expression of PRK, but not a
PRK deletion construct, in transformed A549 fibroblast cells suppresses their
proliferation. Furthermore, fluorescence in situ hybridization analyses show that
the PRK gene localizes to chromosome band 8p21, a region that exhibits a high
frequency of loss of heterozygosity in a variety of human cancers, including head
and neck cancers, and that is proposed to contain two putative tumor suppressor
genes. Considering that PRK plays an important role in the regulation of the G2/M
transition and cell cycle progression, our current studies suggest that
deregulated expression of PRK may contribute to tumor development. Genes
Chromosomes Cancer 27:332-336, 2000.
PMID- 10679925
TI - Expression of the imprinted genes MEST/Mest in human and murine placenta suggests
a role in angiogenesis.
AB - In the mouse fetus, Mest is widely expressed in mesoderm derived tissues. In
separate studies in mice and in humans, it has been shown to be maternally
imprinted, that is, only the paternally inherited allele is active. Here, we show
that starting with implantation, Mest is also expressed in maternal decidua of
the mouse and in placenta of both humans and mice. Expression in murine decidua
was restricted to endothelial cells. After Day 7, expression in the decidua
gradually decreased. Mest-specific RT-PCR and restriction fragment length variant
(RFLV) analysis of decidualized endometrium isolated from (M. musculus x M.
spretus)F1 females showed that only the paternally derived Mest allele was
activated in the decidual endothelium. In the mouse extraembryonic tissues, Mest
transcripts were detected in derivatives of extraembryonic mesoderm only. Here,
hemangioblast precursor cells and endothelial cells were positive. At all
developmental stages of the mouse, trophoblast-derived cells were clearly devoid
of Mest transcripts. In the human placenta MEST transcripts were also detected in
hemangioblast precursor cells, however, MEST was also expressed in villous and
invasive cytotrophoblast. In a human choriocarcinoma/trophoblastic tumour grown
in a nude mouse, human MEST was expressed in the tumour cells, whereas murine
Mest was expressed in endothelia of the murine capillaries. The expression
pattern exhibited by both Mest and MEST in extraembryonic tissues during
development and during formation of choriocarcinoma/trophoblast tumour suggests a
functional role of the MEST proteins related to oncofetal angiogenesis. Dev Dyn
2000;217:1-10.
PMID- 10679926
TI - Embryonic vasculogenesis by endothelial precursor cells derived from lung
mesenchyme.
AB - During development, the lung mesenchyme has a dynamic relationship with the
branching airway. Embryonic lung mesenchyme is loosely packed and composed of
indistinguishable cells, yet it is the source of vascular progenitors that will
become endothelial cells, smooth muscle cells and fibroblasts. In the lung,
vessel development in the periphery proceeds first through vasculogenesis, the
migration and assembly of cells into a primitive network, and subsequently,
through angiogenesis, the sprouting of vessels from this network. As a way to
assess the cellular and molecular mechanisms of lung vascularization, we have
isolated and cloned cell lines from mouse fetal lung mesenchyme (MFLM). Two of
these MFLM cell lines, MFLM-4 and MFLM-91U, display characteristics of an
endothelial lineage. RNA analysis demonstrates transcripts for the vascular
endothelial growth factor receptors R1 and R2, the receptor tyrosine kinases, Tie
1 and Tie-2, as well as the Tie-2 ligands, Ang-1 and -2. The MFLM cell lines form
extensive networks of capillary-like structures with lumens when cultured on a
reconstituted basement membrane. In vivo, following blastocyst injection, the
MFLM cells chimerize endothelium of the lung and areas of the heart vasculature.
The results from these studies suggest that MFLM-4 and MFLM-91U, derived from
embryonic lung mesenchyme, can function in vitro and in vivo as endothelial
precursors and as models of cardiopulmonary vascularization. Dev Dyn 2000;217:11
23.
PMID- 10679927
TI - Regulation of FGF soluble receptor type 1 (SR1) expression and distribution in
developing, degenerating, and FGF2-treated retina.
AB - The spatial and temporal patterns of expression and content of the fibroblast
growth factor (FGF) soluble receptor SR1, a specific inhibitor of FGF, were
investigated during embryonic and postnatal development of the retina in Fisher
rats. As early as at embryonic day 18 (E18), SR1 mRNA and protein were detected
in the retina. SR1 protein was strongly associated with the differentiating
ganglion cells and its distribution paralleled the radial pattern of retinal
development, from center to periphery. From E18 to postnatal day 5, the levels of
both SR1 mRNA and SR1 protein remained constant. Thereafter, they decreased
rapidly, by a factor of 5 in the adult retina. SR1 was labeled in the inner
nuclear layer, but never in the photoreceptor nuclei. In the neural retina of RCS
dystrophic rats, the levels SR1 mRNA and SR1 protein were 2 to 3 times higher
than those in the normal congenic controls, before and during photoreceptor
degeneration. These results provide the first evidence that a natural FGF
inhibitor is regulated during retina development and degeneration and suggest
that changes in SR1 content may be involved in the regulation of FGF activities
in retina. This was confirmed in vivo in RCS rats, in which delayed photoreceptor
apoptosis by intravitreal injection of FGF2 was accompanied by a downregulation
of SR1 expression. Dev Dyn 2000;217:24-36.
PMID- 10679928
TI - Evidence for the expression of neonatal skeletal myosin heavy chain in primary
myocardium and cardiac conduction tissue in the developing chick heart.
AB - We isolated a neonatal skeletal myosin heavy chain (MHC) cDNA clone, CV11E1, from
a cDNA library of embryonic chick ventricle. At early cardiogenesis, diffuse
expression of neonatal skeletal MHC mRNA was first detected in the heart tube at
stage 10. During subsequent embryonic stages, the expression of the mRNA in the
atrium was upregulated until shortly after birth. It then diminished,
dramatically, and disappeared in the adult. On the other hand, in the ventricle,
only a trace of the expression was detected throughout embryonic life and in the
adult. However, transient expression of mRNA in the ventricle was observed, post
hatching. At the protein level, during the embryonic stage, the atrial myocardium
was stained diffusely with monoclonal antibody 2E9, specific for chick neonatal
skeletal MHC, whereas the ventricles showed weak reactivity with 2E9. At the late
embryonic and newly hatched stages, 2E9-positive cells were located clearly in
the subendocardial layer, and around the blood vessels of the atrial and
ventricular myocardium. These results provide the first evidence that the
neonatal skeletal MHC gene is expressed in developing chick hearts. This MHC
appears during early cardiogenesis and is then localized in cardiac conduction
cells. Dev Dyn 2000;217:37-49.
PMID- 10679929
TI - Repression of myosin isoforms in developing and denervated skeletal muscle fibers
originates near motor endplates.
AB - During development of chicken pectoralis muscle, a neonatal myosin heavy-chain
isoform is supplanted progressively by an adult isoform. This expression is under
neuronal control. In this study we test the hypothesis that developmental myosin
transformations are initiated near the motor endplate of each muscle fiber,
thereafter progressing toward the fiber ends. By using immunocytochemical
methods, pectoralis muscle from chickens aged 1-115 days after hatching were
labeled by antibody against neonatal isoform. Ellipse minor axis and mean optical
density of labeled and/or unlabeled fiber profiles from each bird were measured
by computer image analysis. Acetylcholinesterase (AChE) activity was demonstrated
histochemically. Using serial cross sections, we show that smaller fiber profiles
are the tapered ends of larger fiber profiles. The largest fiber profiles
(central regions of the fibers) were the first to lose their neonatal myosin
during development. Motor endplates were localized by AChE activity to the
central regions of the fibers. The pectoralis of mature chickens was denervated
for 3, 7, 15, or 21 days. After 2 weeks' denervation, neonatal myosin is first
reexpressed in the fiber ends. Dev Dyn 2000;217:50-61.
PMID- 10679930
TI - Regulation of the Hoxa4 and Hoxa5 genes in the embryonic mouse lung by retinoic
acid and TGFbeta1: implications for lung development and patterning.
AB - We have previously described a 5; cis-acting retinoic acid response element that
is required for a subset of Hoxa4 expression, including the midgestation mouse
lung. As both retinoids and Hox genes have been implicated in lung development
and patterning, we have examined Hoxa4 expression in the developing mouse lung
and extended our work on its regulation. At E12.5, a Hoxa4/lacZ transgene is
expressed in the mesenchymal compartment of the lung. Later in development
expression is restricted to the proximal mesenchyme and is also observed in
smooth muscle cells, subepithelial fibroblasts, and alveolar cells. We show that
both Hoxa4 and Hoxa5 are upregulated when cultured in the presence of all-trans
retinoic acid. In addition, retinoic acid extends the domain of Hoxa4 and Hoxa5
expression to the periphery of the explants where the distal epithelia are
developing. Interestingly, the effect of retinoic acid on Hoxa5 expression was
not observed in a Hoxa4 mutant background. In contrast, TGFbeta1 was found to
downregulate both Hoxa4 and Hoxa5 expression in cultured lung explants. We also
establish that retinoic acid has the effect of proximalizing the mouse lung when
cultured in a serum-free medium, as evidenced by reduced expression of the distal
marker surfactant protein-C. Lungs from Hoxa4 mutant embryos exhibited a similar
response to retinoic acid, suggesting that Hoxa4 alone is not required for the
proximalizing effect. Based on their retinoid-dependent expression, we conclude
that members of the group 4 and/or group 5 Hox genes are likely to be involved in
patterning of the mouse lung. Dev Dyn 2000;217:62-74.
PMID- 10679931
TI - Suppression of atrial myosin gene expression occurs independently in the left and
right ventricles of the developing mouse heart.
AB - Many cardiac genes are broadly expressed in the early heart and become restricted
to the atria or ventricles as development proceeds. Additional transcriptional
differences between left and right compartments of the embryonic heart have been
described recently, in particular for a number of transgenes containing cardiac
regulatory elements. We now demonstrate that three myosin genes which become
transcriptionally restricted to the atria between embryonic day (E) 12.5 and
birth, alpha-myosin heavy chain (MHC), myosin light chain (MLC) 1A and MLC2A, are
coordinately downregulated in the compact myocardium of the left ventricle before
that of the right ventricle. alpha-MHC protein also accumulates in the right, but
not left, compact ventricular myocardium during this period, suggesting that this
transient regionalization contributes to fktal heart function. dHAND and eHAND,
basic helix-loop-helix transcription factors known to be expressed in the right
and left ventricles respectively at E10. 5, remain regionalized between E12.5 and
E14.5. Downregulation of alpha-MHC, MLC1A, and MLC2A in iv/iv embryos, which have
defective left/right patterning, initiates in the morphological left (systemic)
ventricle regardless of its anatomical position on the right or left hand side of
the heart. This points to the importance of left/right ventricular differences in
sarcomeric gene expression patterns during fktal cardiogenesis and indicates that
these differences originate in the embryo in response to anterior-posterior
patterning of the heart tube rather than as a result of cardiac looping. Dev Dyn
2000;217:75-85.
PMID- 10679932
TI - Differential expression of endothelial beta-catenin and plakoglobin during
development and maturation of the blood-brain and blood-retina barrier in the
chicken.
AB - The development of the blood-brain barrier depends upon the formation of a
closely regulated system of adherens and tight junctions. A prerequisite for a
functional junction system is the linkage of transmembrane adhesion receptors
(cadherins) to the cytoskeleton via catenins. The localization of specific
catenins at the adherens junction correlates with the stability of
interendothelial contacts in vitro, but in vivo data are lacking thus far.
Investigating brain angiogenesis in the chicken, we demonstrated that beta
catenin, but not plakoglobin, initially codistributed with N-cadherin at the
ablumenal endothelial membrane at contact sites to perivascular cells, from where
both antigens disappeared during blood-brain barrier maturation. In contrast,
plakoglobin was most prominent at the interendothelial junction where only small
amounts of beta-catenin were present. Western-blot analysis revealed a stronger
developmental decrease of beta-catenin than plakoglobin, whereas N-cadherin was
completely lost. beta-Catenin but not N-cadherin was reinduced in brain
endothelial cells during dedifferentiation in vitro and localized to the
interendothelial junctions. These first in vivo data support the hypothesis that
endothelial beta-catenin and N-cadherin are transiently relevant for the contact
of brain endothelial to perivascular cells. Plakoglobin seems not to interact
with N-cadherin but is exclusively localized at interendothelial junctions
providing evidence for its role in the formation of stable adherens junctions,
which may play a role for the initiation, and/or stabilization of tight
junctions. Dev Dyn 2000;217:86-98.
PMID- 10679933
TI - Filamin isogene expression during mouse myogenesis.
AB - The developmental pattern of filamin gene expression has been studied in mouse
embryos by using in situ hybridization. The probes used were isoform specific,
(35)S-labeled antisense complementary ribonucleic acids (cRNAs) to the 3;
untranslated region (3; UTR) of muscle-specific and nonmuscle-specific filamin
genes. Northern blot and in situ hybridization results showed that nonmuscle
specific filamin transcripts had a size of 9.5 kb and were expressed in all
nonmuscle tissues. Labeling was most intense in tissues containing a substantial
proportion of epithelial and smooth muscle cells. Muscle-specific filamin
transcripts had a size of 10 kb and were expressed primarily in cardiac and
skeletal muscle. The expression of muscle-specific filamin messenger
ribonucleicacids (mRNAs) was detected in heart at 8.0 days after coitum, whereas
that in the myotomes of somites was not detected until 10.5 days after coitum.
The expression of muscle-specific filamin mRNAs in heart and in skeletal muscle
continued through the subsequent days of myogenesis. The results showed that
muscle-specific filamin gene transcripts are detected before the formation of
myotubes in vivo. This is the first study of filamin gene expression at the early
stages of skeletal muscle development. Dev Dyn 2000;217:99-108.
PMID- 10679934
TI - A novel pbx family member expressed during early zebrafish embryogenesis forms
trimeric complexes with Meis3 and Hoxb1b.
AB - pbx genes encode homeodomain-containing transcriptional regulators that interact
with other proteins to control embryogenesis and tumorigenesis. We present the
characterization of a zebrafish pbx CDNA that appears to encode a novel family
member, pbx4. pbx4 RNA is maternally deposited and is detected throughout the
zebrafish embryo during blastula stages. It becomes excluded from ventroanterior
structures at late gastrula stages and is detected within the forming central
nervous system during segmentation stages. pbx4 expression overlaps with that of
two other homeobox genes, hoxb1b and meis3, in the region of the presumptive
caudal hindbrain during gastrula stages. In vitro binding experiments revealed
that protein complexes containing Pbx4/Meis3 and Pbx4/Hoxb1b, but not
Meis3/Hoxb1b could be generated. A novel trimeric complex containing Pbx4, Meis3,
and Hoxb1b was also formed. We speculate that complexes with different
combinations of Pbx4, Meis3, and Hoxb1b specify different developmental fates
during vertebrate embryogenesis. Dev Dyn 2000;217:109-119.
PMID- 10679935
TI - Transgenic rescue of aganglionosis and piebaldism in lethal spotted mice.
AB - Complete colonization of the gut by enteric neural precursors depends on
activation of ednrB and Ret receptors by their respective ligands, edn3 and gdnf.
Mutations that eliminate expression of either ligand or either receptor produce
intestinal aganglionosis in rodents and humans. Embryos homozygous for the lethal
spotted (ls) allele, a loss of function mutation in the edn3 gene, have no
ganglion cells in their terminal large intestines and are spotted, due to
incomplete colonization of the skin by melanocyte precursors. Expression of edn3
in enteric neural precursors of transgenic mice compensates fully for deficient
endogenous edn3 in ls/ls embryos. The effects of the edn3 transgene are dose
dependent, as lower levels of expression in one line prevent aganglionosis in
only a subset of animals and reduce, but fail to eliminate, piebaldism. In
contrast, expression of neither constitutively active Ret nor activated ras in
enteric neural progenitors alters the severity of aganglionosis or piebaldism in
ls/ls mice. Given the spatial and temporal pattern of edn3-transgene expression,
our results suggest that edn3/ednrB signals are not required prior to the arrival
of crest cells in the gut and endrB stimulation elicits distinct cellular
responses from Ret or ras activation. Dev Dyn 2000;217:120-132.
PMID- 10679936
TI - Mutations in the X-linked pyruvate dehydrogenase (E1) alpha subunit gene (PDHA1)
in patients with a pyruvate dehydrogenase complex deficiency.
AB - Defects in the pyruvate dehydrogenase (PDH) complex are an important cause of
primary lactic acidosis, a frequent manifestation of metabolic disease in
children. Clinical symptoms can vary considerably in patients with PDH complex
deficiencies, and almost equal numbers of affected males and females have been
identified, suggesting an autosomal recessive mode of inheritance of the disease.
However, the great majority of PDH complex deficiencies result from mutations in
the X-linked pyruvate dehydrogenase (E1) alpha subunit gene (PDHA1). The major
factors that contribute to the clinical variation in E1alpha deficiency and its
resemblance to a recessive disease are developmental lethality in some males with
severe mutations and the pattern of X-inactivation in females. To date, 37
different missense/nonsense and 39 different insertion/deletion mutations have
been identified in the E1alpha subunit gene of 130 patients (61 females and 69
males) from 123 unrelated families. Insertion/deletion mutations occur
preferentially in exons 10 and 11, while missense/nonsense mutations are found in
all exons. In males, the majority of missense/nonsense mutations are found in
exons 3, 7, 8 and 11, and three recurrent mutations at codons R72, R263 and R378
account for half of these patients with missense/nonsense mutations (25 of 50). A
significantly lower number of females is found with missense/nonsense mutations
(25). However, 36 females out of 55 affected patients have insertion/deletion
mutations. The total number of female and male patients is thus almost the same,
although a difference in the distribution of the type of mutations is evident
between both sexes. In many families, the parents of the affected patients were
studied for the presence of the PDHA1 mutation. The mutation was never present in
the somatic cells of the father; in 63 mothers studied, 16 were carriers (25%).
In four families, the origin of the new mutation was determined to be twice
paternal and twice maternal.
PMID- 10679937
TI - Molecular basis of multiple exostoses: mutations in the EXT1 and EXT2 genes.
AB - Hereditary multiple exostoses (EXT) is an autosomal dominant disorder
characterized by the formation of exostoses, which are cartilage-capped bony
protuberances mainly located on long bones. Two genes, EXT1 and EXT2, and at
least one other unidentified gene, are known to be involved in the formation of
exostoses. To date, 49 different EXT1 and 25 different EXT2 mutations have been
found in EXT patients, and there is evidence that mutations in these two genes
are responsible for over 70% of the EXT cases. Among the 49 EXT1 mutations there
are 9 nonsense, 21 frameshift, and 5 splice site mutations; 2 in-frame deletions
of 1 and 5 amino acids respectively; and 12 missense mutations. For EXT2, 8
nonsense, 11 frameshift, 3 splice site and 3 missense mutations are described.
The majority of these mutations are mutations causing loss of function, which is
consistent with the presumed tumor suppressor function of the EXT genes.
PMID- 10679938
TI - An update of the mutation spectrum of the survival motor neuron gene (SMN1) in
autosomal recessive spinal muscular atrophy (SMA).
AB - Spinal muscular atrophy (SMA) is characterized by degeneration of motor neurons
in the spinal cord, causing progressive weakness of the limbs and trunk, followed
by muscle atrophy. SMA is one of the most frequent autosomal recessive diseases,
with a carrier frequency of 1 in 50 and the most common genetic cause of
childhood mortality. The phenotype is extremely variable, and patients have been
classified in type I-III SMA based on age at onset and clinical course. All three
types of SMA are caused by mutations in the survival motor neuron gene (SMN1).
There are two almost identical copies, SMN1 and SMN2, present on chromosome 5q13.
Only homozygous absence of SMN1 is responsible for SMA, while homozygous absence
of SMN2, found in about 5% of controls, has no clinical phenotype. Ninety-six
percent of SMA patients display mutations in SMN1, while 4% are unlinked to 5q13.
Of the 5q13-linked SMA patients, 96.4% show homozygous absence of SMN1 exons 7
and 8 or exon 7 only, whereas 3. 6% present a compound heterozygosity with a
subtle mutation on one chromosome and a deletion/gene conversion on the other
chromosome. Among the 23 different subtle mutations described so far, the Y272C
missense mutation is the most frequent one, at 20%. Given this uniform mutation
spectrum, direct molecular genetic testing is an easy and rapid analysis for most
of the SMA patients. Direct testing of heterozygotes, while not trivial, is
compromised by the presence of two SMN1 copies per chromosome in about 4% of
individuals. The number of SMN2 copies modulates the SMA phenotype. Nevertheless,
it should not be used for prediction of severity of the SMA.
PMID- 10679939
TI - A missense mutation in the OCTN2 gene associated with residual carnitine
transport activity.
AB - Primary carnitine deficiency is an autosomal recessive disorder of fatty acid
oxidation caused by defective carnitine transport. This disease can present early
in life with hypoketotic hypoglycemia and acute metabolic decompensation, or
later in life with skeletal or cardiac myopathy. Mutations abolishing the
function of OCTN2, an organic cation/carnitine transporter with twelve putative
transmembrane spanning domains, were recently demonstrated in patients with early
and late-onset (up to seven years of age) presentation of this syndrome. Most of
the reported mutations are null alleles. Here we evaluate the OCTN2 gene in a
male patient who presented at seven years of age with severe dilated
cardiomyopathy. Plasma carnitine levels were undetectable and carnitine transport
by his fibroblasts was reduced to about 3% of normal controls. This patient was
homozygous for a single base pair change in exon 8 of the OCTN2 gene (1354G>A)
converting the codon for Glu 452 to Lys (E452K) in the predicted intracellular
loop between transmembrane domains 10 and 11. Stable expression of the mutant
E452K-OCTN2 cDNA in Chinese hamster ovary (CHO) cells caused a partial increase
in carnitine transport to 2-4% of the levels measured in the wild type
transporter. This reduced transport activity was associated with normal Km toward
carnitine (3.1 +/- 1.1 microM), but markedly reduced Vmax. These results indicate
that primary carnitine deficiency can be caused by mutations encoding for
carnitine transporters with residual activity, and that the E452K affects a
domain not involved in carnitine recognition.
PMID- 10679940
TI - Screening of thiopurine S-methyltransferase mutations by horizontal conformation
sensitive gel electrophoresis.
AB - The genetic polymorphism of thiopurine S-methyltransferase (TPMT) has had a
highly significant clinical impact due to its association with individual
variation in the toxicity and therapeutic efficiency of thiopurine drugs, which
are pharmaceutical agents widely used in the treatment of several kinds of
diseases. Until now, ten mutant alleles responsible for TPMT deficiency and
several silent and intronic mutations have been described. In this work we
present an alternative molecular method for the detection of TPMT alleles. It is
an adaptation for horizontal conditions of a conformation-sensitive gel
electrophoresis technique. The method has proven to be very efficient as a rapid
screening approach for the study of TPMT genetic variability. The method was
applied to analyse eight TPMT exons and the corresponding flanking intronic
regions in a sample of unrelated healthy individuals from North Portugal. Here we
report the allelic frequencies concerning TPMT-deficient alleles and several
silent and intronic mutations, including two newly detected intronic
polymorphisms: an A (-101) T substitution in intron 3 and a variation involving
the number of T nucleotides in a DNA stretch in intron 5. Additionally, we also
present data from a sample of 43 children undergoing therapy for acute
lymphoblastic leukemia. In this clinical sample we have registered a
statistically significant higher frequency for the TPMT*3C allele. This finding
raises the question whether the TPMT genotype can contribute to any genetic
predisposition for development of the malignancy.
PMID- 10679941
TI - Phenylketonuria and hyperphenylalaninemia in eastern Germany: a characteristic
molecular profile and 15 novel mutations.
AB - Phenylketonuria (PKU) is an important error of amino acid metabolism which
results in most patients from phenylalanine hydroxylase (PAH) deficiency. PKU
displays a marked genotypic heterogeneity both within and between different
populations. The aim of this study was to establish the genotypic spectrum of PKU
in eastern Germany, and to compare this to the distribution of mutations in
western Germany. The study population included 302 patients in 290 families who
were followed at treatment centers in Berlin, Leipzig and Jena. The study showed
marked genotypic variability with a total of 75 mutations, including 15 that have
so far not been described (eleven missense mutations, one splicing mutation, and
three small deletions). One of these novel mutations, E183Q, occurred in cis to a
R408W mutation. In the non-immigrant eastern German population, the frequency of
R408W accounted for 40.1% of the PKU alleles. In the immigrant Turkish population
of the former West Berlin, the most prevalent mutation was IVS10-11G>A (57%).
There was a marked difference of the genotypic spectrum between the population
studied here and the data reported from the western part of the country.
PMID- 10679942
TI - Eight novel mutations and consequences on mRNA and protein level in pyruvate
kinase-deficient patients with nonspherocytic hemolytic anemia.
AB - Pyruvate kinase (PK) deficiency (PKD) is an autosomal recessive disorder with the
typical manifestation of nonspherocytic hemolytic anemia. We analyzed the mutant
enzymes of 10 unrelated patients with PKD, whose symptoms ranged from a mild,
chronic hemolytic anemia to a severe anemia, by sequence analysis for the
presence of alterations in the PKLR gene. In all cases the patients were shown to
be compound heterozygous. Eight novel mutations were identified: 458T-->C
(Ile153Thr), 656T-->C (Ile219Thr), 877G-->A (Asp293Asn), 991G-->A (Asp331Asn),
1055C-->A (Ala352Asp), 1483G-->A (Ala495Thr), 1649A-->T (Asp550Val), and 183
184ins16bp. This 16 bp duplication produces a frameshift and subsequent stop
codon resulting in a drastically reduced mRNA level, and probably in an unstable
gene product. Surprisingly, the existence of M2-type PK could be demonstrated in
the patient's red blood cells. The study of different polymorphic sites revealed,
with one exception, a strict linkage of the 1705C, 1738T, IVS5(+51)T, T(10)
polymorphisms and the presence of 14 ATT repeats in intron 11. Our analyses show
the consequences of a distorted structure on enzyme function and we discuss the
correlations between the mutations identified and the parameters indicative for
enzyme function.
PMID- 10679943
TI - Detection of eight novel palmitoyl protein thioesterase (PPT) mutations
underlying infantile neuronal ceroid lipofuscinosis (INCL;CLN1).
AB - The infantile form of neuronal ceroid lipofuscinosis (INCL; CLN1) is the earliest
onset form of the neuronal ceroid lipofuscinoses (NCL), a group of progressive
encephalopathies of children. INCL is caused by mutations in the palmitoyl
protein thioesterase (PPT) gene, and we report here eight novel INCL mutations in
PPT. Five of the mutations, c.456C>A, c.162-163insA, c.174-175delG, c.774
775insA, and a splice acceptor mutation IVS1-2A>G in intron 1, caused the
generation of a premature STOP codon either directly or after a frameshift. One
mutation was a three-bp insertion in exon 2 (c. 132-133insTGT) leading to
insertion of one extra cysteine (Ser44-insCys-Cys45), and another mutation, a 3
bp deletion in exon 3 (c.249-251delCTT), led to deletion of Phe84 in PPT. A
splice acceptor mutation IVS6-1G>T in intron 6 can be predicted to cause skipping
of exon 7 in PPT. All of these novel mutations were associated with the classical
phenotype of INCL, with the first symptoms starting around 12 months of age. The
severe phenotypes could be explained by the nature of the novel mutations: five
are predicted to lead to premature translational termination, thus abolishing the
active site of PPT, and three will probably cause a misfolding of the nascent
polypeptide. Thirty-five percent (7/20) of the disease alleles in these 11
families contained the most prevalent c.451C>T missense mutation outside Finland
[Das et al., 1998]. Consequently, 31 different mutations underlying INCL have
been found so far, the majority leading to classical INCL.
PMID- 10679944
TI - Characterization of six novel mutations in the methylenetetrahydrofolate
reductase (MTHFR) gene in patients with homocystinuria.
AB - Severe deficiency of methylenetetrahydrofolate reductase (MTHFR) is the most
common inborn error of folate metabolism. Patients are characterized by severe
hyperhomocysteinemia, homocystinuria and a variety of neurological and vascular
problems. Eighteen rare mutations have been reported in this group of patients.
Two polymorphisms which cause mild enzyme deficiencies have been described (677C-
>T and 1298A-->C). The first sequence change encodes a thermolabile enzyme and is
associated with mild hyperhomocysteinemia. Six novel point mutations are
described in patients with severe deficiency of MTHFR, along with their
associated polymorphisms and clinical phenotypes. Of the two nonsense mutations
(1762A-->T, 1134C-->G) and four missense mutations (1727C-->T, 1172G-->A, 1768G-
>A, and 358G-->A), one was identified in the N-terminal catalytic domain, while
the others were located in the regulatory C-terminal region. All four residues
affected by missense mutations are conserved in one or more MTHFRs of other
species. This report brings the total to 24 mutations identified in severe MTHFR
deficiency, with two mutations identified in each of 22 patients.
PMID- 10679946
TI - Fifteen new mutations (-195C>T, L-12X, 298-2A>G, T117N, A159T, R229S, 997+2T>A,
E274X, A331T, H364R, D389G, 1256delC, R433H, N461I, C472S) in the tissue
nonspecific alkaline phosphatase (TNSALP) gene in patients with hypophosphatasia.
AB - Hypophosphatasia is a rare inherited disorder characterized by defective bone
mineralization and deficiency of serum and liver/bone/kidney-type alkaline
phosphatase (L/B/K ALP) activity. We report the characterization of tissue
nonspecific alkaline phosphatase (TNSALP) gene mutations in a series of 12
families affected by severe or mild hypophosphatasia. Twenty distinct mutations
were found, 5 of which were previously reported. Nine of the 15 new mutations
were missense mutations (T117N, A159T, R229S, A331T, H364R, D389G, R433H, N461I,
and C472S). The others were 2 nonsense mutations (L-12X and E274X), one single
nucleotide deletion (1256delC), 2 mutations affecting splicing (298-2A>G,
997+2T>A), and a mutation in the major transcription start site (-195C>T). Hum
Mutat 15:293, 2000.
PMID- 10679947
TI - Mutation 985A>G in the MCAD gene shows low incidence in Estonian population.
AB - Medium-chain acyl-CoA dehydrogenase (MCAD) is an enzyme responsible for large
part of mitochondrial beta-oxidation of fatty acids and therefore stays on key
position of cellular energy supply. In case of its deficiency, starvation, rapid
growth periods or infections may cause fatal lack of energy, especially in the
first years of life. MCAD deficiency is inherited in an autosomal recessive
manner and it has been shown to be rather common in some European countries
(Great Britain 1 in 6,000, Switzerland 1 in 10,000). In Caucasoid populations one
mutation, the 985A>G transition, causing the amino acid substitution K329E,
accounts for about 90% of all mutant MCAD alleles. Here we present data about
screening the Estonian population for this mutation. We analyzed the DNA from
1,098 persons from all regions of Estonia (all newborns born in one month) and
found 5 heterozygotes for 985A>G, that makes the carrier frequency 1 in 220 and
the frequency of possibly affected homozygotes 1 out of 193,000. No mutant
alleles were found among the samples of the children, who had unclear diagnosis
for death during the years 1994 and 1995.
PMID- 10679948
TI - Two homozygous mutations (R193W and 794/795 delAA) in the myophosphorylase gene
in a patient with McArdle's disease.
AB - We report two novel homozygous mutations in the myophosphorylase gene (PYGM) in a
patient with McArdle's disease. A C-to-T transition that changed an arginine to
tryptophan at codon 193 (R193W) in exon 5, and a deletion of two adenine base
pairs in exon 20 at codon 794/795 (794/795 delAA) were identified. Several lines
of evidence suggest the pathogenicity of both mutations: (i) they were the only
nucleotide alteration in the coding region and adjacent exon/intron boundaries of
the PYGM gene; (ii) the R193W mutation leads to the replacement of a highly
conserved amino acid residue involved in glucose-6-P binding, and the 794/795
delAA mutation predicts a frameshift and premature termination of the protein;
(iii) 60 normal controls and 20 disease controls did not have the mutations in
their 160 alleles. Hum Mutat 15:294, 2000.
PMID- 10679949
TI - Microsomal triglyceride transfer protein (MTP) gene mutations in Canadian
subjects with abetalipoproteinemia.
AB - Abetalipoproteinemia (ABL) is an extremely rare autosomal recessive disorder,
which is characterized by defective assembly and secretion of plasma
apolipoprotein (apo) B-containing lipoproteins. ABL results from mutations in the
gene encoding the microsomal triglyceride transfer protein (MTP). We sequenced
the MTP gene in six Canadian subjects with ABL, of whom four were found to be
simple homozygotes and two were found to be compound heterozygotes for MTP gene
mutations. Of the 8 MTP gene mutations identified, 6 had not been previously
reported, including two new nonsense mutations (K448X and K842X), two new
missense mutations (S590I and G746E), one new frameshift mutation (1820del1) and
one new splice donor site mutation (G1770A). Despite appropriate treatment with
high doses of fat-soluble vitamins in all subjects, there was a wide variation in
the progression and severity of the clinical phenotypes. For example, the
presence of severe retinopathy and neuropathy did not correlate with the type and
position of the mutation, but rather with the age at diagnosis and onset of
treatment with fat-soluble vitamins. These findings suggest that genetic and non
genetic factors can modulate the clinical impact of mutant MTP in ABL patients.
PMID- 10679950
TI - High incidence of 550delA mutation of CAPN3 in LGMD2 patients from Russia.
AB - Autosomal recessive limb gird muscular dystrophy (LGMD2) is a clinically and
genetically heterogeneous group of diseases that are characterized by progressive
atrophy and weakness of the proximal limb muscles. At least eight genetic loci
leading to LGMD2 are recognized. The proportion of particular gene involved in
producing different forms of LGMD2 shows a marked geographical variation. We
studied 19 LGMD2 patients from Russia (15 families) and found calpain 3 (CAPN3)
gene mutations in most of the patients studied. Sequence analysis of the fourth
exons revealed two sibs - heterozygous compound for a 15-bp deletion (nt598-612)
and 550 adenine deletion, and two sibs homozygous for a 550delA. We developed
assay based on allele specific amplification (ASA) for rapid screening of the
550delA. The ASA assay of the LGMD2 patients under study showed that 7 patients
from 6 families were homozygous for 550delA and 7 patients from 4 families were
heterozygous for 550delA. A linkage analysis employing four microsatellites
flanking the LGMD2A locus was performed. We found complete haplotype identity in
most cases what favors the possibility of a common founder. Heterozygous carriers
of 550delA were found in general population. The crude estimate of the mutation
frequency is 1/150. Hum Mutat 15:295, 2000.
PMID- 10679951
TI - IDDM7 links to insulin-dependent diabetes mellitus in Danish multiplex families
but linkage is not explained by novel polymorphisms in the candidate gene GALNT3.
The Danish Study Group of Diabetes in Childhood and The Danish IDDM Epidemiology
and Genetics Group.
AB - The insulin-dependent diabetes mellitus (IDDM) susceptibility locus IDDM7 on 2q31
links to IDDM in some but not other populations. Linkage of D2S152, the marker
for IDDM7, has hitherto not been demonstrated in Danish patients. GALNT3 that
encodes the UDP-GalNAc: polypeptide N-acetyl-galactosaminyltransferase-T3 (GalNAc
T3), was recently identified and mapped to a region 5-25 cM from D2S152. The
GalNAc transferases may play a role in immune mediated diseases by glycosylating
autoantigens. Hence, the aims of the present study were to investigate by means
of extended transmission disequilibrium testing (ETDT) and transmission
disequilibrium testing (TDT) of the marker for IDDM7, D2S152, the marker for
GALNT3, D2S2363, and novel polymorphisms identified through mutation screening of
the entire GALNT3 for linkage with IDDM in 241 Danish IDDM multiplex families.
ETDT analysis demonstrated linkage between IDDM and D2S152 (P(ETDT)=0.034). A
prevalent T-->A polymorphism, T284A, was found in the GALNT3 3'UTR. Analysis of
the D2S2363 and the T284A GALNT3 transmission patterns did not show linkage to
IDDM in Danish patients (P(ETDT)=0.15 and P(TDT)=0.76, respectively). In
conclusion, IDDM7 (D2S152) links to IDDM in Danish patients, but D2S2363 and the
identified T284A polymorphism in the GALNT3 3'UTR did not. Hence, it is unlikely
that the GALNT3 is an IDDM susceptibility gene.
PMID- 10679952
TI - PCR diagnosis of X-linked ichthyosis: identification of a novel mutation (E560P)
of the steroid sulfatase gene.
AB - X-linked ichthyosis (XLI) is an inherited skin disorder due to deficiency of
steroid sulfatase (STS) activity. XLI has been diagnosed by assaying STS activity
in placenta or lymphocytes of patients after birth. Most patients have a large
deletion of the STS gene, generated by inaccurate recombination at the STS locus.
However, point mutations in the STS gene have been reported in some patients with
complete STS deficiency. In a new case of STS deficiency, we identified an STS
missense mutation, Glu560Pro or E560P. This new point mutation suggests that the
C-terminal region of the STS enzyme is important for STS enzymatic function. Hum
Mutat 15:296, 2000.
PMID- 10679953
TI - Various AGC repeat numbers in the coding region of the human transcription factor
gene E2F-4.
AB - The E2F family of transcription factors regulates the expression of genes
required for DNA synthesis and cell cycle control. The AGC triplet repeat in the
coding region of the E2F-4 gene, a member of the family, has been reported to be
mutated in colorectal cancers with a microsatellite instability (MSI) phenotype.
We found a wider range variation of the repeat number in DNAs from tumors, the
corresponding normal mucosa, and healthy individuals. A total of 5 repeat
variants, ranging from 8 to 17 AGC repeats, was detected in 6 (9.7%) of the 62
healthy individuals and 8 (8.9%) of the 90 normal DNAs of the patients. The wild
type 13 repeat was present in all of these individuals. The variation of the AGC
repeat number may be a polymorphism. Further, loss of heterozygosity (LOH) at the
E2F-4 locus in the tumor tissues of 2 (25%) of the 8 informative cases was
detected. The variation may be a useful marker for detection of LOH in primary
tumors.
PMID- 10679954
TI - The Arg1075His substitution in the FBN1 gene is clinically innocent for Marfan
syndrome.
PMID- 10679955
TI - Polymorphism (g2035C>T) in the amelogenin gene.
PMID- 10679956
TI - A novel DNA polymorphism (4886C>T) in the human LCAT gene.
PMID- 10679957
TI - A novel missense mutation (R712L) adjacent to the "active thiol" region of the
cardiac beta-myosin heavy chain gene causing hypertrophic cardiomyopathy in an
Indian family.
PMID- 10679958
TI - Identification of a novel large F9 gene mutation-an insertion of an Alu repeated
DNA element in exon e of the factor 9 gene.
PMID- 10679959
TI - Identification of a new polymorphism (c134G>A) in the exon 2 of the myelin
protein zero gene.
PMID- 10679960
TI - Introduction to muscular dystrophy.
PMID- 10679961
TI - Plasma membrane cytoskeleton of muscle: a fine structural analysis.
AB - The discovery of dystrophin and its definition as the causative molecule in
Duchenne Muscular Dystrophy has led to a renewed interest in the molecular
structure of the muscle fiber plasma membrane and its association with the
extracellular basal lamina. The original identification of dystrophin gave
credence to the possibility that the plasma membrane of the muscle fiber may be
highly organized and involved in maintaining appropriate homeostasis in this
actively contracting cellular system. In this review, we examine the currently
known members of the muscle fiber plasma membrane cytoskeleton and the
interactions that occur between the different members of this complex using
histological, electron microscopic, and confocal methods. From our studies and
others cited in this review, it is clear that the dystrophin cytoskeletal complex
is not completely understood and component molecules continue to be discovered.
Perhaps equally importantly, currently defined molecules (such as alpha-actinin
or neuronal nitric oxide synthase) are being recognized as being specifically
associated with the complex. What is striking from all of the studies, to date,
is that while we are able to identify members of the dystrophin cytoskeletal
complex and while we are able to associate mutations of individual molecules with
disease(s), we are still unable to truly define the roles of each of the
molecules in maintaining the normal physiology of the muscle fiber.
PMID- 10679962
TI - Immunocytochemical analysis of human muscular dystrophy.
AB - Immunocytochemistry is an essential tool for the assessment of muscle biopsies
from patients with muscular dystrophy, especially the recessive forms. Antibodies
can detect primary defects when there is an alteration in expression, in
particular in Xp21 muscular dystrophies, Emery-Dreifuss muscular dystrophy, the
limb-girdle dystrophies caused by abnormal expression of the sarcoglycans, and in
the form of congenital muscular dystrophy linked to the gene for laminin alpha2.
Absence of a protein is easily observed and reduction in expression can be
assessed provided adequate controls and baselines are established. Assessment of
secondary defects can also be of diagnostic value; they widen the understanding
of pathology changes, and are helping in the development of therapeutic
strategies.
PMID- 10679963
TI - Dystrophin and utrophin: genetic analyses of their role in skeletal muscle.
AB - Since the identification of dystrophin as the causitive factor in Duchenne
muscular dystrophy, there has been substantial progress in understanding the
functions and interactions of this protein. Dystrophin has been shown to interact
with a group of peripheral- and trans-membrane proteins known as the dystrophin
associated protein complex (DAPC) and mutations in some of the members of this
complex have been shown to account for other forms of muscular dystrophy. This
review summarizes the experiments using transgenic and knockout mouse models that
have defined the roles of dystrophin, and the dystrophin-related protein utrophin
at the skeletal muscle membrane and at the neuromuscular junction. These studies
are presented in the context of other known interactions at the muscle membrane.
Studies of the dystrophin-deficient mdx mouse have lead to a greater
understanding of the human disease. Knockouts and transgenics of utrophin have
shown this protein to be sufficient to functionally compensate for dystrophin.
Dystrophin transgenic mice combined with the mdx mouse have been used to study
the function of specific domains of the dystrophin protein. Together these animal
models have led to a delineation of protein functions and localization patterns
that will be useful for the generation of potential therapies for DMD.
PMID- 10679964
TI - Sarcoglycans in muscular dystrophy.
AB - Muscular dystrophy is a heterogeneous genetic disease that affects skeletal and
cardiac muscle. The genetic defects associated with muscular dystrophy include
mutations in dystrophin and its associated glycoproteins, the sarcoglycans.
Furthermore, defects in dystrophin have been shown to cause a disruption of the
normal expression and localization of the sarcoglycan complex. Thus,
abnormalities of sarcoglycan are a common molecular feature in a number of
dystrophies. By combining biochemistry, molecular cell biology, and human and
mouse genetics, a growing understanding of the sarcoglycan complex is emerging.
Sarcoglycan appears to be an important, independent mediator of dystrophic
pathology in both skeletal muscle and heart. The absence of sarcoglycan leads to
alterations of membrane permeability and apoptosis, two shared features of a
number of dystrophies. beta-sarcoglycan and delta-sarcoglycan may form the core
of the sarcoglycan subcomplex with alpha- and gamma-sarcoglycan less tightly
associated to this core. The relationship of epsilon-sarcoglycan to the
dystrophin-glycoprotein complex remains unclear. Animals lacking alpha-, gamma-
and delta-sarcoglycan have been described and provide excellent opportunities for
further investigation of the function of sarcoglycan. Dystrophin with
dystroglycan and laminin may be a mechanical link between the actin cytoskeleton
and the extracellular matrix. By positioning itself in close proximity to
dystrophin and dystroglycan, sarcoglycan may function to couple mechanical and
chemical signals in striated muscle. Sarcoglycan may be an independent signaling
or regulatory module whose position in the membrane is determined by dystrophin
but whose function is carried out independent of the dystrophin-dystroglycan
laminin axis.
PMID- 10679965
TI - Merosin and congenital muscular dystrophy.
AB - Merosin (also called as Laminin-2) is an isoform of laminin comprised of the
alpha2, beta1 and gamma1 chains. In European populations, half of the patients
with classical congenital muscular dystrophy have mutations of the LAMA2 gene
(6q22-23) and present reduced or absence of laminin alpha2 chain. This form is
generally referred to as merosin-deficient CMD. Merosin-deficient CMD is
characterized by involvement of not only skeletal muscle but also central and
peripheral nervous systems: Extensive brain white matter abnormalities are found
by magnetic resonance imaging (MRI). However, most patients show no mental
retardation. Recent case studies reported that some patients have several
structural abnormalities such as abnormal cerebral cortical gyration, hypoplasia
of cerebellum and pons, and dilation of ventricles. At present, functions of
merosin related to muscle degeneration have not been fully elucidated. In
addition, the mechanisms responsible for pathogenesis of diffuse brain white
matter abnormalities remain to be determined. As mouse models for merosin
deficient CMD, three spontaneous mutants(dy, dy(2J), dy(PAS1)) and two mutants
named dy(W) and dy(3K) by targeted gene disruption have been reported. These mice
will help to elucidate the pathogenesis of merosin-deficient CMD and serve to
develop therapy.
PMID- 10679966
TI - Eye muscle sparing by the muscular dystrophies: lessons to be learned?
AB - The devastating consequences of the various muscular dystrophies are even more
obvious when a muscle or muscle group is spared. The study of the exceptional
cell or tissue responses may prove to be of considerable value in the analysis of
disease mechanisms. The small muscles responsible for eye movements, the
extraocular muscles, have functional and morphological characteristics that set
them aside from other skeletal muscles. Notably, these muscles are clinically
unaffected in Duchenne/Becker, limb-girdle, and congenital muscular dystrophies,
pathologies due to a broken mechanical or signaling linkage between the
cytoskeleton and the extracellular matrix. Uncovering the strategies used by the
extraocular muscles to "naturally" protect themselves in these diseases should
contribute to knowledge of both pathogenesis and treatment. We propose that
careful investigation of the cellular determinants of extraocular muscle-specific
properties may provide insights into how these muscles avoid or adapt to the
cascade of events leading to myofiber degeneration in the muscular dystrophies.
PMID- 10679967
TI - Cell cycle behavior and MyoD expression in response to T3 differ in normal and
mdx dystrophic primary muscle cell cultures.
AB - Since mdx limb muscle regeneration in vivo is accompanied by rapid myoblast
proliferation and differentiation compared to normal, we tested the possibility
that proliferation and differentiation were differentially regulated in normal
and mdx dystrophic muscle cells. Cell cycle behavior, MyoD expression, and the
effects of thyroid hormone (T3) treatment were examined in primary cultures.
Using a 4-hour pulse time for bromodeoxyuridine (BrdU) incorporation during S
phase, the phases of the cell cycle (early S, late S, G(2)/M, and G(0)/G(1)) were
separated by 2-colour fluorescence (BrdU/PI) analysis using flow cytometry. The
G(0)/G(1)-early S and the late S-G(2)/M transitions were examined under the
influence of T3 in cycling normal and mdx muscle cell cultures over a 20-hour
time period. Myogenesis and differentiation were assessed morphologically and by
immunostaining for MyoD protein. Mdx cultures had fewer cells in G(0)/G(1) at 20
hours and more cells in early and late S-phase compared to normal cultures. T3
significantly increased the proportion of normal cells in early S-phase by 20
hours, and reduced the proportions in G(2)/M phase. Over the same time interval
in parallel cultures, the proportion of MyoD+ normal cells decreased
significantly. In the absence of T3, mdx cell cultures showed greater proportions
of cells in S-phase than normal cultures, and similar increases in S-phase and
loss of MyoD expression over time. However, mdx cultures had no change in the
proportion that were MyoD+ during T3 treatment. The results confirm that T3 in
primary cultures increased proliferation and prevented the de-differentiation of
mdx cells to a greater degree than was typical of normal cells. The different
susceptibilities to T3-related shifts between proliferation and differentiation
observed in vitro support the idea that committed mdx myoblasts may be more
activated and proliferative than normal myoblasts during regeneration in vivo.
PMID- 10679968
TI - Progress in myoblast transplantation: a potential treatment of dystrophies.
AB - Myoblast transplantation (MT) consists of injecting normal or genetically
modified myogenic cells into muscles, where they are expected to fuse and form
mature fibers. As an experimental approach to treat severe genetic muscle
diseases, MT was tested in dystrophic patients at the beginning of the 1990s.
Although these early clinical trials were unsuccessful, MT has progressed through
the research on animal models. Many factors that may condition the success of MT
were identified in the last years. The present review updates our knowledge on MT
and describes the different problems that have limited its success. Factors that
were first underestimated, like the specific immune response after MT, are
presently well characterized. Destruction of the hybrid fibers by activated T
lymphocytes and production of antibodies against the transplanted myoblasts take
place after MT and are responsible for the graft rejection. The choice of the
immunosuppression seems to be very important, and FK506 is the best agent known
to allow the best results after MT. Under FK506 immunosuppression, very efficient
MT were obtained both in mice and monkeys. Moreover, in dystrophic mice it was
demonstrated that MT ameliorates some phenotypical characteristics of the
disease. The improvement of the survival of the transplanted cells and the
increase of their migration into the injected tissue are presently under
investigation. Some of the present research is directed also to bypass the
immunosuppression by using the patient's own cells for MT. In this sense, efforts
are conducted to introduce the normal gene into the patient's myoblasts before MT
and to improve the ability of these cells to proliferate in vitro. Micros. Res.
Tech. 48:213-222, 2000.
PMID- 10679970
TI - Obituary: takekiyo matsuo (1943-1999)
PMID- 10679969
TI - Developments in gene therapy for muscular dystrophy.
AB - Gene therapy for muscular dystrophy (MD) presents significant challenges,
including the large amount of muscle tissue in the body, the large size of many
genes defective in different muscular dystrophies, and the possibility of a host
immune response against the therapeutic gene. Overcoming these challenges
requires the development and delivery of suitable gene transfer vectors.
Encouraging progress has been made in modifying adenovirus (Ad) vectors to reduce
immune response and increase capacity. Recently developed gutted Ad vectors can
deliver full-length dystrophin cDNA expression vectors to muscle tissue. Using
muscle-specific promoters to drive dystrophin expression, a strong immune
response has not been observed in mdx mice. Adeno-associated virus (AAV) vectors
can deliver small genes to muscle without provocation of a significant immune
response, which should allow long-term expression of several MD genes. AAV
vectors have also been used to deliver sarcoglycan genes to entire muscle groups.
These advances and others reviewed here suggest that barriers to gene therapy for
MD are surmountable.
PMID- 10679971
TI - Introduction to modern biological mass spectrometry.
PMID- 10679972
TI - Structural studies of the Maillard reaction products of a protein using ion trap
mass spectrometry.
AB - The early stage products of the Maillard reaction of egg white lysozyme with D
glucose were studied. Incubation with D-glucose at 50 degrees C for 20 days
caused reaction on the Lys and Arg residues of lysozyme as follows: all of the
six Lys residues and 10 of the 11 Arg residues in lysozyme reacted with D
glucose; Arg 61 did not react with D-glucose. The Lys residues reacted with D
glucose with 1 mol of dehydration per mole of residue, and the Arg residues
reacted with 2 mol of dehydration per mole of residue. The major constituent of
the Amadori product with the epsilon-amino group of the Lys residue and the D
glucose was found to be the beta-pyranose form. The structure of the early stage
product of the Maillard reaction of a protein with a sugar is the same as that of
an amino acid with a sugar.
PMID- 10679973
TI - Survey of the proton affinities of adenine, cytosine, thymine and uracil
dideoxyribonucleosides, deoxyribonucleosides and ribonucleosides.
AB - The kinetic method was applied to the determination of the proton affinities
(PAs) of modified deoxy- and dideoxyribonucleosides. A correlation between the
measured PAs and the replacement of one of the three hydroxyl groups of the
ribose unit is presented. A PA scale was obtained which shows that the
replacement of the primary or of one or both secondary hydroxyl groups of a
ribonucleoside with a hydrogen atom induces the lowering or the enhancement of
the nucleoside PA, respectively. The scale extends over a very narrow range of
approximately 2 kcal mol(-1), thus demonstrating the sensitivity of the kinetic
method in the evaluation of small differences in thermodynamic parameters.
PMID- 10679974
TI - Structure determination of two conotoxins from Conus textile by a combination of
matrix-assisted laser desorption/ionization time-of-flight and electrospray
ionization mass spectrometry and biochemical methods.
AB - Two highly modified conotoxins from the mollusc Conus textile, epsilon-TxIX and
Gla(1)-TxVI, were characterized by matrix-assisted laser desorption/ionization
and electrospray mass spectrometry and also by electrospray ionization tandem and
triple mass spectrometry in combination with enzymatic cleavage and chemical
modification reactions. The mass spectrometric studies allowed the confirmation
of the sequence determined by Edman degradation and assignment of unidentified
amino acid residues, among which bromotryptophan residues and an O-glycosylated
threonine residue were observed. Methyl esterification was found necessary for
the site-specific assignment of the Gla residues in the peptides.
PMID- 10679975
TI - Improving the sensitivity of the end-cap reflectron time-of-flight mass
spectrometer.
AB - A miniaturized time-of-flight (TOF) mass spectrometer utilizes an end-cap
reflectron to achieve high kinetic energy focusing and improved mass resolution.
However, the coaxial geometry gives rise to considerable losses in sensitivity
resulting from reflected ion trajectories close to the center. These trajectories
were modeled, using initial ion velocity distributions in the radial direction up
to 300 m s(-1), and the portion of the active area of the detector that is
utilized was evaluated experimentally using a variable diameter iris diaphragm.
The sensitivity was improved by modification of the reflectron by tilting the end
cap electrode 4 degrees and redirecting the ions to a portion of the detector
active area. Sensitivity was then measured as 3 fmol of the peptide substance P.
PMID- 10679976
TI - Construction of a new multi-turn time-of-flight mass spectrometer.
AB - A new type of multi-turn time-of-flight mass spectrometer was constructed,
consisting of four cylindrical electric sectors and 28 electric quadrupole
lenses, the size of the vacuum chamber being 60 x 70 x 20 cm. It was demonstrated
that the mass resolution can be increased according to the number of cycles of
the ions through the ion optical system.
PMID- 10679977
TI - Dissociation study of tellurium cluster ions, Te(n)(+) (n = 25-85) using
secondary ion mass spectrometry.
AB - Dissociation pathways of tellurium clusters, Te(n)(+) (n = 25-85), were
investigated by secondary ion mass spectrometry. Positively charged ions were
generated from a tellurium sheet by bombardment with 10 keV xenon ion beam. Mass
analyses of cluster ions were performed using a grand-scale sector mass
spectrometer. In the first field-free region, Te(n)(+) (n = 25-80) had a large
dissociation probability with five- and six-atom emission and Te(n)(+) (n = 50
85) had a slightly large dissociation probability with 10- and 11-atom emission.
Five- and six-atom dissociation in the second field-free region could be also
observed. These results were most likely due to the cluster emission processes
for Te(n)(+), although sequential atom emission and cluster emission could not be
distinguished by this type of experiments.
PMID- 10679978
TI - Quantitative electrospray ionization mass spectrometric studies of ternary
complexes of amino acids with Cu(2+) and phenanthroline.
AB - Electrospray ionization (ESI) mass spectra of ternary complexes of Cu(2+) and
1,10-phenanthroline with the 20 essential amino acids (AA) were investigated
quantitatively. Non-basic amino acids formed singly charged complexes of the
[Cu(AA - H)phen](+) type. Lysine (Lys) and arginine (Arg) formed doubly charged
complexes of the [Cu(HAA - H)phen](2+) type. Detection limits were determined for
the complexes of phenylalanine (Phe), glutamic acid (Glu) and Arg, which were at
low micromolar or submicromolar concentrations under routine conditions.
Detection limits of low nanomolar concentrations are possible for amino acids
with hydrophobic side-chains (Phe, Tyr, Trp, Leu, Ile) as determined for Phe. The
efficiencies for the formation by ESI of gaseous [Cu(AA - H)phen](+) ions were
determined and correlated with the acid-base properties of the amino acids,
ternary complex stability constants and amino acid hydrophobicities expressed as
the Bull-Breese indices (DeltaF). A weak correlation was found between DeltaF and
the ESI efficiencies for the formation of gaseous [Cu(AA - H)phen](+) [Cu(HAA -
H]phen](2+) and [AA + H](+) ions that showed that amino acids with hydrophobic
side-chains were ionized more efficiently. In the ESI of binary and ternary amino
acid mixtures, the formation of gas-phase Cu-phen complexes of amino acids with
hydrophobic side-chains was enhanced in the presence of complexes of amino acids
with polar or basic side-chains. An interesting enhancement of the ESI formation
of [Cu(Glu - H)phen](+) was observed in mixtures. The effect is explained by ion
cluster formation at the droplet interface that results in enhanced desorption of
the glutamic acid complex.
PMID- 10679979
TI - High-energy collision-induced dissociation of small polycyclic aromatic
hydrocarbons.
AB - High-energy collision-induced dissociation (CID) experiments on polycyclic
aromatic hydrocarbons (PAHs) having 2-6 rings, naphthalene, anthracene,
phenanthrene, fluoranthene, pyrene and coronene, were performed, and the relative
abundances of their fragment ions were investigated as a function of collision
energy. The results revealed that the PAHs except naphthalene showed a bimodal
type distribution of positive fragmentation ions, which is closely similar to the
fragment-ion distribution reported for the CID of three-dimensional fullerene,
C(60)(+) and C(70)(+). The three-ring isomers of anthracene and phenanthrene and
the four-ring isomers of fluoranthene and pyrene can be distinguishable in their
spectra under an electron ionization energy of 70 eV, but the high-energy CID
spectra of the three- and four-ring isomers were almost identical. The
fragmentation corresponding to fragment ions in the low-mass region of the
bimodal CID spectra could be interpreted by the simple statistical model that
fragment ions are formed by random evaporation from the molecular ions after a
considerable structural rearrangement, 'phase transition', occurring at some high
energy state.
PMID- 10679980
TI - Metastable decay of peptide ions on a Fourier transform mass spectrometer
equipped with an external ion source.
AB - Metastable decay rates of two peptides, RPPGFSPF and PKPQQFFGLM, were determined
from ions produced in an external matrix-assisted laser desorption/ionization
source with a Fourier transform mass spectrometer. An isolation and subtraction
method that gives difference spectra was employed to monitor the product
formation and metastable decays. The dependence of metastable decay rates on
laser fluences and matrixes was demonstrated.
PMID- 10679981
TI - Double transacetalization of diacylium ions.
AB - A novel gas-phase reaction of diacylium ions of the O=C=X(+)=C=O type (X = N, CH)
is reported: double transacetalization with cyclic acetals or ketals. The
reaction is exothermic and highly efficient, and forms members of a new class of
highly charged-delocalized ions: cyclic ionic diketals. Pentaquadrupole double-
and triple-stage mass spectrometric (MS(2) and MS(3)) experiments reveal the high
double transacetalization reactivity of O=C=N(+)=C=O and O=C=CH(+)=C=O, whereas
the synthesis of differently substituted cyclic ionic diketals is performed in
MS(3) experiments via sequential mono- and double transacetalization of
O=C=N(+)=C=O and O=C=CH(+)=C=O with different acetals. With cyclic acetals, the
acylium-thioacylium ion O=C=N(+)=C=S reacts promptly and selectively by mono
transacetalization at its acylium site, but the free thiacylium site of its
cyclic ionic ketal is nearly unreactive by double transacetalization. Therefore,
only the acylium site of O=C=N(+)=C=S can be efficiently protected by
transacetalization. Low-energy MS(3) collision-induced dissociation of the cyclic
ionic diketals of O=C=N(+)=C=O and O=C=CH(+)=C=O sequentially frees each of the
protected acylium site to form the mono-derivatized ion, and then the fully
deprotected diacylium ion.
PMID- 10679982
TI - Atmospheric pressure chemical ionization multi-stage mass spectrometry in the
characterization of stereoisomeric synthons of cyclopropane amino acids.
AB - The mass spectrometric behaviour of (1S,2R)-, (1R,2R)-, (1R,2S)- and (1S,2S)-2
[(S)-2,2-dimethyl-1, 3-dioxolan-4-yl]-1-spiro-?4'[2'-phenyl-5'(4'H)-oxazolone]?
cyclopropane (2) and (1S,2R)-, (1R,2R)-, (1R,2S)- and (1S, 2S)-methyl-1-benzamido
2-[(S)-2,2-dimethyl-1, 3-dioxolan-4-yl]cyclopropanecarboxylate (3) was studied
under atmospheric pressure ionization conditions and by multi-stage mass
spectrometric (MS(n)) experiments performed with an ion trap. Interestingly, by
using methanol as solvent, compounds 2 lead to [M + H + CH(3)OH](+) ions which,
as proved by collisional experiments, exhibit the same structure of the
corresponding compound 3. MS/MS of [MH](+) ions allows a clear characterization
of the different stereoisomers, which give rise to specific fragmentation
pathways, rationalized with respect to the structure of the neutral molecules.
PMID- 10679983
TI - Determination of the carbohydrate composition and the disulfide bond linkages of
bovine lactoperoxidase by mass spectrometry.
AB - The extent and distribution of N-glycosylation and the nature of most of the
disulfide bond linkages were determined for bovine lactoperoxidase through
proteolytic and glycolytic digestions combined with matrix-assisted laser
desorption/ionization mass spectrometric analysis. In addition, 98% of the
primary sequence of the protein was confirmed. All five of the asparagines
present in sequons were found to be glycosylated, predominantly by high mannose
and complex structures. Six disulfide bonds were assigned, including Cys 32-Cys
45, Cys 146-Cys 156, Cys 150-Cys 174, Cys 254-Cys 265, Cys 473-Cys 530 and Cys
571-Cys 596.
PMID- 10679984
TI - Determination of [(13)C]galactose enrichment in human plasma by gas
chromatography/positive chemical ionization tandem mass spectrometry.
AB - Galactosemia is a potentially fatal disease resulting from a deficiency of
galactose-1-phosphate uridyl transferase. In order to perform mechanistic studies
designed to elucidate further the etiology of the disease, we required a method
to monitor (13)C enrichment in plasma galactose following a single oral dose or
intravenous infusion of [1-(13)C]galactose. Determinations of plasma
[(13)C]galactose enrichment requires methodology with extremely high specificity
because of potential interference from other low molecular mass plasma
constituents and from glucose, an isomer which is present in much higher
concentrations. We have developed a method based on gas chromatography/positive
chemical ionization tandem mass spectrometry (GC/PCI-MS/MS) for the precise and
accurate determination of plasma [(13)C]galactose enrichment. The method employed
a pentaacetylaldononitrile derivative of galactose in order to improve its GC and
MS characteristics. Peak areas resulting from the transitions m/z 328 --> 106 and
m/z 329 --> 107 were used to quantify the relative abundance of labeled and
unlabeled galactose. Validation of the method was performed by determination of
the precision and accuracy over a wide range of galactose concentrations and
(13)C enrichments. The GC/PCI-MS/MS method was able to determine accurately
enrichments at galactose concentrations down to 0.8 microM in the presence of 4
mM glucose, making it both highly selective and the most sensitive method
currently available.
PMID- 10679986
TI - Antisense peptide interactions studied by electrospray ionization mass
spectrometry.
AB - Non-covalent interactions between met- and leu-enkephalins and their antisense
peptides were studied by electrospray ionization mass spectrometry. Mixtures of
sense and antisense peptides gave both the corresponding homodimers and
heterodimers. The relative abundance ratios of the heterodimer to that of the
homodimer of the sense peptide and the relative stability constants of the
heterodimers were compared with the corresponding values from mixtures of the
sense peptides and a control peptide. The results show that there is a
preferential interaction between the sense and antisense peptides compared with
that between the sense and control peptides.
PMID- 10679985
TI - Analysis of oxidized glycerophosphocholine lipids using electrospray ionization
mass spectrometry and microderivatization techniques.
AB - Oxidized low-density lipoprotein (LDL) is thought to play an important role in
atherogenesis and cardiovascular disease in humans. Oxidized LDL is a complex
mixture of many oxidized species, including numerous oxidized
glycerophospholipids. Electrospray ionization and tandem mass spectrometry as
well as microchemical derivatization of high-performance liquid
chromatographically purified fractions derived from oxidized LDL were
investigated as means to determine the structure of individual components present
in oxidized LDL. One major oxidized phosphocholine lipid had an [M + H](+) ion at
m/z 650. Derivatization to the trimethylsilyl ether and methoxime caused shifts
in mass which, along with negative ion collision-induced dissociation mass
spectra, were consistent with the presence of three species, 1-palmitoyl-2-(9
oxononanoyl)glycerophosphocholine and two isomeric 1-octadecanoyl-2
(hydroxyheptenoyl)glycerophosphocholines. These species were chemically
synthesized. Trimethylsilylation of free hydroxyl groups increased the mass of
the phospholipid acyl chains containing hydroxyl groups by 72 u. Conversion of
carbonyl groups to the methoxylamine derivative increased the mass by 29 u.
Ozonolysis of those products which contained double bonds proved to be a facile
technique to determine the position and number of double bonds present. The use
of these techniques was illustrated in the structural characterization of one
major component (m/z 650, positive ions) in oxidized LDL as 1-octadecanoyl-2-(7
hydroxyhepta-5-enoyl)glycerophosphocholi ne. A possible mechanism for the
formation of this unique chain-shortened glycerophospholipid is proposed.
PMID- 10679987
TI - Tandem mass spectrometric analysis of (13)C-containing ions from a mixture of
homologous peptides differing by one mass unit at a residue.
AB - Tandem mass spectrometry of a mixture of two peptides that differ from each other
by a single mass unit due to mutation is presented. The mutant beta-globin of
hemoglobin Hoshida is present along with the normal counterpart, and the amino
acid substitution of glutamine for glutamic acid is located within tryptic
peptide T5 of M(r) 2057. 9. The mass of the mutated peptide is 1 u lower. In the
isotopic cluster for the doubly charged ion of the peptide T5, the resolved ion
with mass of 1030.0 represents the normal peptide with 93 (12)C atoms and the
mutated one with 92 (12)C and one (13)C atoms. Collision-induced dissociation
(CID) of this composite ion identified the mutation by presenting a key fragment
derived from the (12)C-only mutant peptide, as reported in a previous study.
Similarly, when an ion containing multiple (13)C atoms was selected as a
precursor for CID, the mutation could be identified, even in large fragments, by
a marked change in the shape of the isotopic cluster for the consecutive product
ions. This study demonstrates the merit of selecting a resolved ion rather than
the whole isotopic cluster as a precursor in the CID measurements of large
peptides or proteins for characterizing heterozygous mutations.
PMID- 10679988
TI - First generation and characterization of the enol of glycine, H(2)N--CH=C(OH)(2),
in the gas phase.
AB - The enol of glycine, H(2)N-CH&dbond;C(OH)(2), is generated in the gas phase by
neutralization of the corresponding radical cation, which is available by
dissociative electron ionization of isoleucine. Reionization approximately 0.6
micros later shows that the isolated enol (2) exists and does not isomerize to
the significantly more stable glycine molecule, H(2)N--CH(2)--COOH (1); hence the
intramolecular tautomerization 2-->1 must be associated with high barriers. The
neutralization-reionization reactivity of 1(+*) further confirms that neutral
glycine has a canonical structure (1) and is not a zwitterion. The unimolecular
chemistry of 1(+*) is dominated by C--C bond cleavage to the immonium ion
(+)H(2)NCH(2); in sharp contrast, 2(+*) primarily loses H(2)O. The ylide ion
(+)H(3)N--CH(*)--COOH, an intermediate in the water loss from 2(+*), is found to
readily equilibrate to 2(+*) prior to dissociation. Tautomers 1(+*) and 2(+*)
differ in their charge-stripping behavior, with only 2(+*) forming a stable
dication. The radical anions 1(-*) and 2(-*), formed by charge reversal of 1(+*)
and 2(+*), respectively, dissociate extensively to (mainly) different closed
shell fragment anions. An important channel is H(*) loss; 1(-*) yields the
carboxylate ion H(2)N--CH(2)--COO(-) whereas 2(-*) yields the enolate ion H(2)N-
CH=C(OH)O(-).
PMID- 10679989
TI - Mapping of surrogate markers of cellular components and structures using laser
desorption/ionization mass spectrometry.
AB - Laser desorption/ionization mass spectrometry (LDI-MS) has been used to assess
the potential of using surrogate markers, bound to cellular structures containing
nucleic acids, to image or map the position of these structures within biological
samples. In this study, organic dyes were used as markers because of their
established use in the histochemical marking of nucleic acids, and also because
they are amenable to LDI-MS. Eight cationic dyes were tested and all could be
desorbed from nucleic acid samples without additional matrix after specifically
binding to these molecules. Methylene Blue was the best of these based on its
sensitivity to detection by LDI-MS and the fact that it can be washed from the
tissue in areas where it was not specifically bound to provide low-intensity
background signals. Experiments are reported which characterize the M(+) ion
signal obtained from Methylene Blue with regard to sensitivity, reproducibility
and possible use for quantitation. This dye was used to map (with a lateral
resolution of 25 microm) several nucleic acid-containing samples spotted on
prepared surfaces, and to image the location of nucleic acids in two model
tissues, retinal vertical sections and thyroid whole mount sections.
PMID- 10679990
TI - Location of alkali metal binding sites in endothelin A selective receptor
antagonists, cyclo(D-Trp-D-Asp-Pro-D-Val-Leu) and cyclo(D-Trp-D-Asp-Pro-D-Ile
Leu), from multistep collisionally activated decompositions.
AB - We previously showed by using mass spectrometry that endothelin A selective
receptor antagonists BQ123 and JKC301 form novel coordination compounds with
sodium ions. This property may underlie the ability of an ET(A) antagonist to
induce net tubular sodium reabsorption in the proximal tubule cells and reverse
acute renal failure induced by severe ischemia. We have now defined the metal
binding sites on BQ123 and JKC301 by subjecting the metal-containing peptides to
multiple stages of collisionally activated decomposition (CAD) in an ion trap
mass spectrometer. When submitted to low-energy CAD, the ring opens at the Asp
Pro amide bond. The metal ion, which bonds, inter alia, to the carbonyl oxygen of
the proline residue, acts as a fixed charge site, and directs a charge-remote,
sequence-specific fragmentation of the ring-opened peptide. Amino acid residues
are sequentially cleaved from the C-terminal end, and the terminal aziridinone
structure moves one step toward the N-terminus with each C-terminal amino acid
residue removed. These observations are the basis of a new method to sequence
cyclic peptides. Amino acid residues are observed as sets of three ions, a*(n)PD,
b*(n)PD and c*(n)PD where n is the number of amino acid residues in the peptide.
PMID- 10679991
TI - Compassionate conservatism in urinary cytology.
PMID- 10679992
TI - Fine-needle aspiration cytology of salivary gland: a review of 341 cases.
AB - Three hundred and forty-one salivary gland fine-needle aspiration (FNA) cytology
specimens taken over a 6-yr period were reviewed and correlated with clinical
and/or histological findings. The aspirates were derived from parotid gland (212
cases), submandibular gland (124 cases), and minor salivary gland (5 cases). The
major diagnostic categories were unsatisfactory (10 cases), normal (100 cases),
sialadenitis (74 cases), cyst (34 cases), lipoma (5 cases), pleomorphic adenoma
(55 cases), Warthin's tumor (36 cases), and malignancy (27 cases). The latter
included 14 primary salivary neoplasms (4 lymphomas of mucosa-associated lymphoid
tissue (MALT) type, 3 adenocarcinomas, 2 squamous carcinomas, 2 adenoid cystic
cacinomas, and one case each of carcinoma ex pleomorphic adenoma,
undifferentiated carcinoma, and high-grade mucoepidermoid carcinoma), and 13
metastases, 9 of which were derived from squamous carcinomas of head and neck
origin. Clinicopathological review showed that 88 of 91 (97%) benign epithelial
tumors and 27 of 31 (87%) malignant neoplasms with adequate FNA sampling were
accurately diagnosed cytologically. False-negative results were caused by
sampling error (7 cases), most notably in cystic tumors, or were due to
misinterpretation of uncommon neoplasms (3 cases). The overall sensitivity,
specificity, and accuracy were 92%, 100%, and 98%, respectively. FNA cytology
provides accurate diagnosis of most salivary gland lesions and contributes to
conservative management in many patients with nonneoplastic conditions.
PMID- 10679993
TI - Cytology and flow cytometry of malignant effusions of multiple myeloma.
AB - Identifying malignant plasma cells in body fluids from multiple myeloma patients
is important for therapeutic and prognostic considerations. This can be difficult
when plasma cells are mature in appearance or low in number. We examined the
cytological and flow cytometric findings of myelomatous pleural and pericardial
effusions from 8 patients with advanced multiple myeloma. Cytoplasmic
immunoglobulin light chain excess vs. DNA ploidy in the plasma-cell population
was evaluated by flow cytometry (FCM). The cytology smears of one pericardial and
14 pleural effusions from the 8 patients were reviewed. Screening Papanicolaou
stained smears facilitated the detection of malignant nuclear features; however,
morphology of plasma cells was best seen in Diff-Quik-stained smears. Low
cellularity and inadequate air-drying of smears accounted for the false-negative
cytology seen in two fluids from a single patient. A malignant plasma cell
population was identified in 9 of 10 fluids submitted for FCM, including the two
fluids with negative cytology. The false-negative FCM was from a suboptimal
specimen with high background staining. Six fluids had an aneuploid DNA content,
and four were diploid. A combination of Papanicolaou- and Diff-Quik-stained
smears is recommended for the evaluation of plasma cells in effusions from
patients with multiple myeloma. Cytology and flow cytometry confirmed malignancy
in 87% and 90% of fluids evaluated, respectively; all cases were diagnosed by
either one or both methods. Our results suggest that FCM and cytology of serous
effusions in multiple myeloma patients are complementary and should be used in
difficult cases. Diagn. Cytopathol. 2000;22:147-151.
PMID- 10679994
TI - DNA flow cytometry of non-Hodgkin's lymphomas: correlation with cytologic grade
and clinical relapse.
AB - In this prospective study, we correlated cytological grading and clinical follow
up of non-Hodgkin's lymphomas (NHL) with DNA flow cytometry (FCM) data from fine
needle aspiration biopsy (FNAB) material. FNAB was performed from 34 successive
cases of NHL, and the aspirated material was analyzed by DNA FCM. Cytological
subtyping and grading were done by modified Working Formulation. Cases were
followed up for 2.5 yr, and cytological grading, clinical follow-up, and DNA FCM
data were correlated. There were 8 cases of low, 14 intermediate, and 12 high
grade NHL. None of the cases of low-grade NHL showed DNA aneuploidy. Of the 8 DNA
aneuploid cases, 5 were of intermediate and 3 were of high-grade NHL. Mean growth
fraction (GF) of low-grade, intermediate-grade, and high-grade NHL was 6.1, 9.4,
and 19.4, respectively. DNA aneuploidy was statistically significant (P < 0.05)
between low- vs. intermediate- and high-grade NHL. Growth fraction was also
statistically significant between low- vs. high-grade NHL. Six cases showed
clinical recurrence, and one case died within 6 mo of diagnosis, due to
widespread involvement of NHL. DNA aneuploidy and mean GF of recurrent and
nonrecurrent cases were statistically significant (P < 0.05) irrespective of
grading of NHL. DNA aneuploidy and GF are not well-correlated with morphological
grading (by the Working Formulation). However, these two criteria are important
for assessment of early clinical relapse of NHL.
PMID- 10679995
TI - Incidental sampling of branchial remnants: a potential source of error in fine
needle aspiration of neck lesions-a case report.
AB - Remnants of the branchial apparatus can produce lesions in the head and neck
region in later life, often amenable to fine-needle aspiration (FNA) diagnosis.
Yet such remnants or rudimentary lesions can remain clinically undetected and can
later interfere with the cytologic interpretation of other deep lesions of the
neck, as the present case demonstrates. In this case the lesion, which by a
subsequent resection turned out to be a neurilemmoma, had been adequately sampled
by the FNA, yet the cytologic diagnosis was sidetracked by the presence in the
specimen of immature squamous epithelial tissue fragments and other elements
(multinucleated histiocytes, calcifications), on the basis of which the diagnosis
of an epithelial lesion, likely malignant, was made. The neck surgery and a
preceding endoscopic examination of the mouth, pharynx, and larynx did not
identify such a lesion, but a detailed microscopic examination of the
fibroadipose tissue between the tumor and the peripharyngeal region revealed the
presence of epithelial microfragments with morphology partly corresponding to
that of the FNA cytology, highly indicative of a branchiogenic lesion in the
peripharyngeal region. The basic embryology of the branchial apparatus resulting
in such defects is presented, as well as tentative guidelines for recognizing
material deriving from accidental sampling of such lesions during FNA
investigations of deep-seated masses of the neck. Diagn. Cytopathol. 2000;22:157
160.
PMID- 10679996
TI - Peripheral primitive neuroectodermal tumor of the parotid gland region: report of
a case with fine-needle aspiration findings.
AB - A case of peripheral primitive neuroectodermal tumor of the parotid gland region
in a 38-yr-old woman is reported. She had a 1-yr history of a large, firm, and
slightly tender left parotid-region mass. CT scan showed an invasive tumor
involving the parotid gland, mandible, infratemporal fossa, and parapharyngeal
space. Fine-needle aspiration cytology of the mass showed a highly cellular,
poorly cohesive smear pattern exhibiting small cuboidal cells, with fibrillary
cytoplasm forming occasional rosette-like structures. Numerous intact single
cells with fragile cytoplasm, finely granular chromatin, and inconspicuous
nucleoli were present together with free-lying nuclei in the background.
Histologic, immunohistochemical, and ultrastructural findings confirmed the
diagnosis. Diagn. Cytopathol. 2000;22:161-166. Published 2000 Wiley-Liss, Inc.
PMID- 10679997
TI - Nontyrosine crystalloids in salivary gland lesions: report of seven cases with
fine-needle aspiration cytology and follow-up surgical pathology.
AB - We report a series of seven patients who underwent fine-needle aspiration (FNA)
for clinically apparent parotid gland lesions. In all seven cases, numerous to
abundant polyhedral, multifaceted (nontyrosine) crystalloids were noted in the
background of scanty cellular specimens composed predominantly of oncocytic
cells. Subsequent surgical excision showed that three of the seven glands
revealed sialolithiasis and sialadenitis without evidence of neoplasia. The
histology of the remaining four cases consisted of two Warthin's tumor, one
oncocytic papillary cystadenoma, and one cellular benign mixed tumor. In all
seven cases the nontyrosine crystalloids were found in highest concentrations in
cystic spaces lined with oncocytic metaplastic cells. We conclude that
nontyrosine cystalloids can be associated with both neoplastic and nonneoplastic
salivary gland disease, and they may be a product of oncocytic cell secretion.
Diagn. Cytopathol. 2000;22:167-171.
PMID- 10679998
TI - Fine-needle aspiration biopsy of postradiation epithelioid angiosarcoma of
breast.
AB - Angiosarcoma of breast skin and parenchyma is a rarely reported complication of
irradiation for breast carcinoma. We report a case of a subareolar epithelioid
angiosarcoma arising 8 years subsequent to lumpectomy and irradiation of the
ipsilateral breast for infiltrating carcinoma. The epithelioid appearance of the
neoplastic cells on fine-needle aspiration biopsy (FNA) biopsy suggested a
recurrence of the primary carcinoma. Careful attention to certain cytomorphologic
features and cell block immunohistochemistry were useful in the distinction from
recurrent carcinoma. Cytologic features that identified this neoplasm as an
angiosarcoma included marked cell discohesiveness, elongate cytoplasmic processes
or "pseudopodia," heterogeneous cell size, large nucleoli or macronucleoli, and
cytoplasmic lumina. Immunohistochemical markers, including Factor VIII antigen,
CD31, and CD34, were positive, confirming the vascular nature of the neoplasm.
Other markers ruled out morphologically similar neoplasms such as recurrent
carcinoma and melanoma. Epithelioid angiosarcoma should be included in the
differential diagnosis of a suspected recurrence of breast carcinoma several
years postirradiation therapy. Diagn. Cytopathol. 2000;22:172-175.
PMID- 10679999
TI - Cytology of polypoid adenomyomas: a report of two cases.
AB - Uterine polypoid adenomyomas, both typical and atypical variants, often arise in
the lower uterine segment or endocervical canal as pedunculated polypoid masses
that may be accessible for cytologic sampling. However, their cytologic findings
have rarely been described in the literature. Two women in their reproductive age
presented with abnormal vaginal bleeding. The cervicovaginal smear of the first
patient contained sheets and strips of reactive endocervical cells in an
inflammatory background. In addition, loose aggregates of spindle-shaped smooth
muscle cells were also noted. The findings were consistent with those of a
typical polypoid adenomyoma. The cervicovaginal smears of the second patient
consisted of tightly packed, crowded clusters of glandular cells which were
initially interpreted as atypical glandular cells, suspicious of adenocarcinoma.
In retrospect, loose aggregates of smooth muscle stromal cells were noted.
Subsequent curettage revealed an atypical polypoid adenomyoma. The cytologic
findings of typical polypoid adenomyoma were nonspecific except for the presence
of loose aggregates of smooth muscle cells. The cytologic features of an atypical
polypoid adenomyoma may mimic that of a neoplastic glandular process. The
findings of tightly packed clusters of glandular cells and loose aggregate of
bland-appearing smooth muscle cells in premenopausal patients may suggest the
diagnosis of atypical polypoid adenomyoma. Diagn. Cytopathol. 2000;22:176-180.
PMID- 10680000
TI - Cytology of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman
disease).
AB - Sinus histiocytosis with massive lymphadenopathy (SHML) is a benign, self
limiting condition of unknown etiology, which generally presents as massive
bilateral cervical lymphadenopathy. It is important to distinguish SHML from
other causes of histiocytosis because of the different treatment modalities. This
study was carried out to assess the utility of fine-needle aspiration cytology
(FNAC) findings in SHML and to distinguish if from other reactive
lymphadenopathies. The lymph nodes in 4 patients (3 male and 1 female) presenting
with massive bilateral cervical lymphadenopathy were aspirated. All presented
with persistent bilateral cervical lymphadenopathy, polymorphnuclear
leukocytosis, and raised erythrocyte sedimentation rate (ESR). Smears showed a
reactive lymphoid population consisting of mature lymphocytes, plasma cells, a
few polymorphs, and many histiocytes showing emperipolesis. Based on the
cytologic and clinical findings, a diagnosis of SHML was made. Histopathology
confirmed the diagnosis in all cases. A conclusive diagnosis of SHML can be based
on cytology, provided that the cytologic findings are interpreted in the
appropriate clinical context. Biopsy can be avoided in these patients. Diagn.
Cytopathol. 2000;22:181-185.
PMID- 10680001
TI - Performance characteristics of the Indiana University Medical Center endometrial
sampler (Tao Brush) in an outpatient office setting, first year's outcomes:
recognizing histological patterns in cytology preparations of endometrial
brushings.
AB - Following successful hysterectomy-controlled trials, Tao brush endometrial
cytology with liquid fixation was offered to clinicians for office use. This
report recounts our first year's cytology and correlative histology outcomes. One
hundred thirteen cases were accrued. Correlative tissue examinations comprising
Pipelle (Prodimed, Neuilly-en-Thelle, France) biopsy, hysteroscopy and biopsy,
dilatation and curettage, and hysterectomy were available at this institution for
59 cases. In 42 cases, cytology diagnoses could be compared to histology
diagnoses. Twenty-five of 63 normal brushings were followed up. Fourteen were
normal. Eleven Pipelle biopsies of cytologically atrophic endometrium were
quantitatively limited and insufficient for diagnosis. Thirty-seven cases were
abnormal, and 15 of these showed nuclear anaplasia. Twenty-eight of the abnormal
cases were followed up. All correlative tissue examinations confirmed an
abnormality. All 15 cases with nuclear anaplasia showed significant
histopathology comprising atypical endometrial hyperplasia, endometrial
intraepithelial neoplasia (EIN), endometrial intraepithelial carcinoma (EIC), and
invasive adenocarcinoma. There were 13 inadequate endometrial brushings. Three
cases had insufficient cellular material. The remaining 10 cases were cellular
but were chiefly cervical/endocervical samples. Two of the cellular cases
resulted from clinicians failing to replace the protective sheath over the brush
bristles before removing the Tao brush from the endometrial cavity. The remaining
11 cases resulted from inaccessibility of the uterine cavity due to a tight or
stenotic cervix. The Tao brush is a reliable uterine sampling device that
performs well as a diagnostic tool for outpatient assessment of the endometrium
of women with patent cervices. An advantage of endometrial cytology is that it
accurately represents atrophic endometrium, and it is an effective case-finding
tool for EIN and EIC. Women with tight or stenotic cervices are poor candidates
for endometrial brushing, and may experience pain if the procedure is attempted.
Diagn. Cytopathol. 2000;22:186-195.
PMID- 10680002
TI - Expression of cytokeratin 19 in cytologic specimens of thyroid.
PMID- 10680003
TI - Fine-needle aspiration of intra- and extraocular masses.
PMID- 10680004
TI - Regarding the validity of cytology proficiency testing.
PMID- 10680005
TI - Reply to dr. cramer
PMID- 10680007
TI - Publisher's announcement
PMID- 10680006
TI - Cytopathology in the United Kingdom: 1854 to the present.
AB - The paper traces the history of cytopathology in the U.K. from the time of the
pioneers in the last century to the 1930s and continues with the development of
cervical and breast screening, with reference to training and quality control, to
the present time. Diagn. Cytopathol. 2000;22:203-206.
PMID- 10680008
TI - Cancer gene therapy: hard lessons and new courses.
AB - Gene therapy for the treatment of cancer was initiated with high levels of
optimism and enthusiasm. Recently, this perception has had to be tempered by the
realisation that efficiency and accuracy of gene delivery remain the most
significant barriers to its success. So far, there has been a disappointing
inability to reach target cells with sufficient efficacy to generate high enough
levels of direct killing and this has necessitated the invocation of bystander
effects in order for any potential strategy to be convincing. At least in the
foreseeable future, clinical advance will come from co-operation with other more
established disciplines - such as chemotherapy, radiotherapy and immunotherapy.
This is inevitable - and necessary - in order to prove that gene therapy can have
efficacy as part of a combinatorial therapy, before hoping to move clinical
mountains alone. In addition, there will have to be a thorough understanding of
the clinical situations in which gene therapy will be used in order both to
understand its own limitations, and to exploit its full potential. This will
enable it to find the appropriate clinical niche in which its abilities will be
optimally useful. Finally, anyone wishing to practise clinical cancer gene
therapy will rapidly have to learn the ways of the free market and be able to
juggle commercial necessities with ideological purity. Gene Therapy (2000) 7, 2
8.
PMID- 10680009
TI - The application of gene therapy in autoimmune diseases.
AB - The application of gene therapy in autoimmune disease represents a novel use of
this technology. The goal of gene therapy in the treatment of autoimmune disease
is to restore 'immune homeostasis' by countering the pro-inflammatory effects of
the CD4+ T cells in the lesions of autoimmunity. This can be accomplished by
adoptive therapy with transduced T cells which can specifically home to the site
of inflammation and secrete 'regulatory' protein(s) to ameliorate the
inflammation or by direct targeting of the retroviral vector to activated T cells
in the sites of inflammation. Transduction of autoantigen recognizing CD4+ T
cells, to secrete anti-inflammatory products, may become the 'magic bullet' to
combat the ravages of autoimmune inflammation and tissue destruction. Gene
Therapy (2000) 7, 9-13.
PMID- 10680010
TI - Gene therapy in transplantation in the year 2000: moving towards clinical
applications?
AB - Transplantation faces several major obstacles that could be overcome by
expression of immunomodulatory proteins through application of gene therapy
techniques. Gene therapy strategies to prolong graft survival involve gene
transfer of immunosuppressive or graft-protecting molecules. Very promising
results have been obtained in small animal experimental models with inhibitors of
co-stimulatory signals on T cells, immunosuppressive cytokines, donor major
histocompatibility antigens and regulators of cell apoptosis or oxidative stress.
The application of gene therapy techniques to transplantation offers a great
experimental and therapeutic potential. Local production of immunosuppressive
molecules may increase their therapeutic efficiency and reduce their systemic
effects. When compared with other clinical situations, gene therapy in
transplantation offers several potential advantages. Gene transfer into the graft
can be performed ex vivo, during the transit between the donor and the recipient,
thus avoiding many of the hurdles encountered with in vivo gene transfer.
Furthermore, the difficulties associated with immune responses to the gene
transfer vectors and transient gene expression may be easier to overcome when
gene therapy protocols are applied to transplantation than when applied to other
clinical situations. The next century should witness a rapid increase in the
application of gene therapy techniques to large animal pre-clinical models of
transplantation and later to clinical trials. Gene Therapy (2000) 7, 14-19.
PMID- 10680011
TI - Lentiviral vectors: turning a deadly foe into a therapeutic agent.
AB - The past 3 years have witnessed the spectacular irruption of lentiviral vectors
into the limelight of the gene therapy scene. Owing to their ability to deliver
transgenes in tissues that had long appeared irremediably refractory to stable
genetic manipulation, lentivectors have opened fresh perspectives for the genetic
treatment of a wide array of hereditary as well as acquired disorders, and a
concrete proposal for their clinical use seems imminent. This article traces the
path that has led to this rapid development and describes the current state of
the art in the design and production of lentiviral vectors. The important
question of biosafety is discussed. This system seems to have the edge over other
gene delivery tools for particular targets, however, there remain several issues
to be resolved before lentivectors make it to the bedside. Gene Therapy (2000) 7,
20-23.
PMID- 10680012
TI - AAV vectors: is clinical success on the horizon?
AB - Potential applications and impact of the adeno-associated virus (AAV) as a gene
transfer vector have expanded rapidly in the last decade. Recent advances in the
production of high-titer purified rAAV vector stocks have made the transition to
human clinical trials a reality in the last moments of the millenium. Production
improvements will be complemented in the coming years with understanding of and
innovations in the targeting and packaging of rAAV, the design of transgene
cassettes, and the host immune response to the vectors. These expected areas of
progress are discussed, with special attention to clinical applications for which
rAAV vectors may help close the gap towards successful gene therapy. Gene Therapy
(2000) 7, 24-30.
PMID- 10680013
TI - Nonviral gene therapy: promises and challenges.
AB - The last 10 years have seen substantial progress in the development and
application of nonviral vectors in gene therapy. However, many problems remain to
be resolved before nonviral gene therapy can become a standard clinical practice.
This review highlights the major breakthroughs in this field. The problems and
future research directions are also discussed. Gene Therapy (2000) 7, 31-34.
PMID- 10680014
TI - Functional balance between T cell chimeric receptor density and tumor associated
antigen density: CTL mediated cytolysis and lymphokine production.
AB - Genetically engineered expression of tumor-specific single chain antibody
chimeric receptors (ch-Rec) on human T lymphocytes endow these cells with the
parental monoclonal antibody (mAb) dictated tumor specificity and may be useful
for clinical immuno-genetherapy. Therefore it was of importance to assess how the
densities of tumor-specific receptors and tumor associated antigens (TAA),
respectively, affect primary human T lymphocyte functions in relation to target
cell susceptibilities to lysis. We therefore studied the functional balance
between ch-Rec densities on human T lymphocytes and TAA on tumor cells. The gene
construct encoding a ch-Rec derived from (1) a renal carcinoma cell (RCC)
specific mouse mAb (G250), and (2) the human signal transducing Fc(epsilon)RI
gamma-chain was used. To obtain ch-RecHIGH-POS and ch-RecLOW-POS T lymphocytes,
two distinct retroviral vectors were used to introduce the gene constructs into
primary human T lymphocytes. Levels of ch-Rec-redirected T lymphocyte mediated
tumor cell lysis, as well as lymphokine production were determined using RCC
lines as target/stimulator cells, which express either no or increasing densities
of the TAA. A functional and dynamic balance between ch-Rec densities on
cytotoxic T lymphocytes (CTLs) on the one hand and TAA densities on RCCs on the
other, was found. In short, ch-RecHIGH-POS CTLs are triggered by TAAHIGH-POS as
well as TAALOW-POS RCCs to lyse tumor cells and produce (IFN-gamma and TNF-alpha)
lymphokine. In contrast, ch-RecLOW-POS T lymphocytes are only triggered for
cytolysis and lymphokine production by relatively TAAHIGH-POS RCCs. In
conclusion, (1) the activation of T lymphocyte responses is co-determined by the
expression levels of the ch-Rec on T lymphocytes and the TAA on tumor cells and
(2) at relatively high T lymphocyte ch-Rec expression levels the CTLs lyse tumor
cells with a wide range of TAA densities. Gene Therapy (2000) 7, 35-42.
PMID- 10680015
TI - Genetically modified CD34+ cells as cellular vehicles for gene delivery into
areas of angiogenesis in a rhesus model.
AB - To develop a cellular vehicle able to reach systemically disseminated areas of
angiogenesis, we sought to exploit the natural tropism of circulating endothelial
progenitor cells (EPCs). Primate CD34+ EPCs were genetically modified with high
efficiency and minimal toxicity using a non-replicative herpes virus vector.
These EPCs localized in a skin autograft model of angiogenesis in rhesus monkeys,
and sustained the expression of a reporter gene for several weeks while
circulating in the blood. In animals infused with autologous CD34+ EPCs
transduced with a thymidine kinase-encoding herpes virus, skin autografts and
subcutaneous Matrigel pellets impregnated with vascular growth factors underwent
necrosis or accelerated regression after administration of ganciclovir.
Importantly, the whole intervention was perfectly well tolerated. The
accessibility, easy manipulation, lack of immunogenicity of the autologous CD34+
cell vehicles, and tropism for areas of angiogenesis render autologous CD34+
circulating endothelial progenitors as ideal candidates for exploration of their
use as cellular vehicles when systemic gene delivery to those areas is required.
Gene Therapy (2000) 7, 43-52.
PMID- 10680016
TI - Effective suicide gene therapy in vivo by EBV-based plasmid vector coupled with
polyamidoamine dendrimer.
AB - This study demonstrates in vivo effectiveness of a nonviral vector system,
Epstein-Barr virus (EBV)-based plasmid vector coupled with polyamidoamine (PAMAM)
dendrimer (EBV/polyplex), in suicide gene therapy of cancer. The EBV-based vector
is a plasmid vector containing EBV nuclear antigen 1 (EBNA1) gene and oriP from
EBV genome. HSV-1 tk gene was transferred into Ewing's sarcoma cell lines, A4573
and KP-EWS-YI, by using an EBV-based plasmid vector, pSES.Tk, or a conventional
plasmid vector, pS.Tk. Cells transfected with pSES.Tk/dendrimer showed
approximately 100 times lower ID50 to ganciclovir (GCV) compared with those
transfected with pS. Tk/dendrimer. Intratumoral injection of pSES.Tk/dendrimer
but not pS. Tk/dendrimer drastically suppressed the growth of tumors which had
generated from A4573 or Huh7 hepatocellular carcinoma (HCC) cells inoculated into
severe combined immunodeficiency (SCID) mice. The treatment with
pSES.Tk/dendrimer also resulted in significant prolongation of survival of the
mice implanted with A4573. These results suggest that the EBV/polyplex system
could be useful for in vivo suicide gene therapy of cancer. Gene Therapy (2000)
7, 53-60.
PMID- 10680017
TI - Gene transfer facilitated by a cellular targeting molecule, reovirus protein
sigma1.
AB - To facilitate eventual genetic vaccination of mucosal tissues, a receptor
mediated gene transfer system was devised using the reovirus adhesin, protein
sigma1. Highly efficient uptake and internalization of protein sigma1 polylysine
(PL) DNA complexes could be demonstrated by fluorescent microscopy. Successful
cellular transfection of rodent and human cell lines was obtained with the
recombinant protein sigma1 as a PL-DNA complex, and could be shown to be receptor
specific. Transfection efficiency was dependent upon the ratio of DNA complexed
to protein sigma1-PL and chloroquine treatment improved transfection efficiency
dramatically. To test its ability to bind a mucosal inductive tissue, recombinant
protein sigma1 was specifically bound to the nasal-associated lymphoid tissues
(NALT). Thus, recombinant protein sigma1-PL-DNA conjugates can efficiently bind
and transfect cells that express the receptor for protein sigma1. Gene Therapy
(2000) 7, 61-69.
PMID- 10680018
TI - Fas ligand gene-carrying adeno-5 AdEasy viruses can be efficiently propagated in
apoptosis-sensitive human embryonic retinoblast 911 cells.
AB - Recent reports have pointed out the difficulties in generating recombinant
adenoviral vectors expressing FasL using eukaryotic cells. In the present study
we cloned the murine FasL (mFasL) gene into the pCA14 or pShuttle vectors and
recombined them with the adeno-5 virus backbone pBHG10 or pAdEasy-1 in eukaryotic
(911 cells) or prokaryotic (E. coli) cells, respectively. Recombination of pCA14
mFasL with pBHG10 in Fas-carrying 911 cells leads to rapid expression of mFasL
and cell death by apoptosis before virus replication is initiated. The same
effect is observed when 911 cells are transfected with the pCA14-mFasL shuttle
vector only. If recombination (pShuttle-mFasL with pAdEasy-1) is performed first
in bacteria and 911 cells are transfected thereafter with recombined AdEasy
mFasL, virus production starts immediately and the cells survive longer. The
resulting AdEasy-mFasL viruses are able to infect other eukaryotic cells and
induce expression of functional mFasL. This study describes a method for
efficient generation of recombinant FasL adeno-5 viruses in eukaryotic cells. The
method may be generally suitable for producing viruses carrying deleterious
genes. Gene Therapy (2000) 7, 70-74.
PMID- 10680020
TI - New tools for the generation of E1- and/or E3-substituted adenoviral vectors.
AB - We have designed new vectors for the construction of recombinant adenoviruses
containing expression cassettes in the E1 and/or E3 regions. Using a versatile
set of restriction enzymes, the cassettes are cloned into small bacterial vectors
and subsequently introduced into large plasmids containing the adenoviral
sequences. Two positive selection markers facilitate the recovery of a cosmid
containing a copy of the sequence of the recombinant adenovirus. The resulting
cosmid is transfected into 293 or 911 cells in order to rescue the virus.
Importantly, the method does not require any recombination event, either in E.
coli or in mammalian cells. The entire procedure can generate viral plaques in 12
days. Gene Therapy (2000) 7, 80-87.
PMID- 10680019
TI - A binary adenoviral vector system for expressing high levels of the proapoptotic
gene bax.
AB - The bax gene plays a critical role in signaling apoptosis and expression through
gene transfer may be valuable in the treatment of a variety of apoptosis-related
diseases such as cancer. However, constructing an adenoviral vector expressing a
bax gene driven by a constitutive promoter has been difficult, presumably because
of the gene's high proapoptotic activity. Here we report a system that induces
the expression of the bax gene safely by adenovirus-mediated gene cotransfer.
Briefly, the system involves an adenoviral vector containing a human bax cDNA
driven by a synthetic promoter consisting of five GAL4-binding sites and a TATA
box (GT). This vector expresses a minimal background level of bax protein in
cultured mammalian cells thus preventing apoptosis of packaging cells, however,
expression of the bax gene can be induced substantially in vitro and in vivo by
transferring it into target cells along with an adenoviral vector expressing the
transactivator, fusion protein GAL4/VP16. Extensive apoptosis was observed after
induction of the bax gene both in cultured human lung carcinoma cells and in the
livers of Balb/c mice. Our results suggest that this GAL4 gene regulatory system
provides an alternative approach to constructing viral vectors that express
potentially toxic genes. Gene Therapy (2000) 7, 75-79.
PMID- 10680021
TI - Guest Editor Dr B Hogan.
PMID- 10680022
TI - Optimal therapeutic management of non-Q-wave myocardial infarction.
PMID- 10680023
TI - Methods used to interpret the 12-lead electrocardiogram: Pattern memorization
versus the use of vector concepts.
AB - This article extols the value of using Grant's approach to the interpretation of
electrocardiograms (ECGs). The essay includes a discussion on how people learn
and emphasizes the difference in memorizing information, thinking, and learning.
Simply stated, the brains of most people are not designed to memorize countless
numbers of ECG patterns. Accordingly, the essay supports the view that a method
of interpretation must be used, and the reader is encouraged to use basic
principles of electrocardiography, including vector concepts, to interpret each
ECG.
PMID- 10680024
TI - Selective estrogen receptor modulators--a new age of estrogens in cardiovascular
disease?
AB - A large body of evidence suggests hormone replacement therapy (HRT) reduces
cardiovascular risk in postmenopausal women. It is, however, associated with
serious side effects, such as increased risk of breast and endometrial cancer.
This has likely caused uneasiness among both women and health care providers. A
new class of compounds, called selective estrogen receptor modulators (SERMs),
have emerged. Through their interactions at the estrogen receptor level they have
become a class of compounds distinct from estrogen. While they share similar
effects with estrogen on such factors as lipid profile and bone density, they
affect other tissues differently. Specifically, they do not induce endometrial
hyperplasia and are therefore not associated with endometrial cancer. In vitro
studies have also shown that they inhibit lipoprotein oxidation and vascular
smooth muscle cell proliferation. The cumulative effects of these compounds may
prove quite beneficial in reducing cardiovascular risk in postmenopausal women
while avoiding serious side effects. This may, in turn, ease much of the anxiety
surrounding the issue of HRT. Clinical trials are presently being conducted to
evaluate the effectiveness of raloxifene, a SERM, on cardiovascular risk
reduction in postmenopausal women.
PMID- 10680025
TI - Anomalies in the dosing of diltiazem.
AB - From early research, investigators understood that the dose of diltiazem required
for the treatment of hypertension (commonly 360 mg/day) was greater than that
required for the treatment of angina (commonly 240 mg/day). Nonetheless, studies
of recent prescribing practices show that the 240 and 180 mg capsule strengths
constitute more than 70% of the diltiazem prescriptions for hypertension.
Physicians became accustomed to the lower antianginal doses of diltiazem for 7
years before a hypertension indication was approved. Subsequently, these dosing
levels were reinforced by the production of once-a-day formulations with highest
capsule strengths of 240 mg and 300 mg. These strengths were dictated by the
sheer bulk of the formulations, which limited how much diltiazem could be
inserted into the #00 capsule, the largest capsule that can be comfortably
administered. An examination of the combined data from the six randomized,
blinded, and placebo-controlled trials submitted to the FDA for the original new
drug applications of the three formulations of diltiazem available in the United
States shows a clear linear dose-response relationship between diltiazem dose and
blood pressure lowering through the 480-540 mg/day range. It also demonstrates
that the 90-120 mg/day range is the "no-effect dose." These conclusions are
supported by a MEDLINE review of all other studies of multilevel dosing of higher
dose levels of diltiazem. The data support the conclusion that diltiazem is
generally underdosed, but when properly dosed may be the single most potent
antihypertensive overall.
PMID- 10680026
TI - Dipyridamole-induced reversible thallium-201 defect in patients with vasospastic
angina and nearly normal coronary arteries.
AB - BACKGROUND: Dipyridamole is a vasodilator of resistance vessels and has no
vasoconstrictive effect on large coronary arteries. HYPOTHESIS: The present study
used dipyridamole thallium-201 (201Tl) scintigraphy to clarify the role of
microvasculature in coronary flow limitation in patients with vasospastic angina
and normal coronary arteries. METHODS: Sixteen patients underwent dipyridamole
and exercise 201Tl scintigraphy and provocative coronary angiography with
acetylcholine. All patients showed coronary spasm (> 90% vasoconstriction
concomitant with ST change) in at least one vessel. RESULTS: Dipyridamole or
exercise caused only ST depression despite the ST elevation observed at
spontaneous attack. Dipyridamole 201Tl scintigraphy demonstrated the reversible
defects (11 cases), as did exercise 201Tl scintigraphy (13 cases). The region of
201Tl defect was not always consistent with the territories of angiographically
depicted vasospastic arteries. Basal coronary tone, assessed by percentage of
diameter change of epicardial arteries from baseline to isosorbide dinitrate
administration, did not differ between the positive and the negative defect
regions. CONCLUSION: These results support the hypothesis that, in addition to
epicardial coronary spasm, the dysfunction of microvasculature is responsible for
abnormal coronary perfusion in the subgroup of patients with vasospastic angina
and normal coronary arteries.
PMID- 10680027
TI - Rest and exercise hemodynamics before and after valve replacement--a combined
Doppler/catheter study.
AB - BACKGROUND: Hemodynamic improvement is a common finding following valve
replacement. However, despite a normally functioning prosthesis and normal left
ventricular ejection fraction, some patients may show an abnormal hemodynamic
response to exercise. METHODS: In a combined catheter/Doppler study, rest and
exercise hemodynamics were evaluated in 23 patients following aortic (n = 12)
(Group 1) or mitral valve (n = 11) (Group 2) replacement and compared with
preoperative findings. Patient selection was based on absence of coronary artery
disease and left ventricular failure as shown by preoperative angiography.
Cardiac output, pulmonary artery pressure, pulmonary capillary pressure, and
pulmonary resistance were measured by right heart catheterization, whereas the
gradient across the valve prosthesis was determined by Doppler echocardiography.
Postoperative evaluation was done at rest and during exercise. The mean follow-up
was 8.2 +/- 2.2 years in Group 1 and 4.2 +/- 1 years in Group 2. RESULTS: With
exercise, there was a significant rise in cardiac output in both groups. In Group
1, mean pulmonary pressure/capillary pressure decreased from 24 +/- 9/18 +/- 9
mmHg preoperatively to 18 +/- 2/12 +/- 4 mmHg postoperatively (p < 0.05), and
increased to 43 +/- 12/30 +/- 8 mmHg with exercise (p < 0.05). The corresponding
values for Group 2 were 36 +/- 12/24 +/- 6 mmHg preoperatively, 24 +/- 7/17 +/- 6
mmHg postoperatively (p < 0.05), and 51 +/- 2/38 +/- 4 mmHg with exercise (p <
0.05). Pulmonary vascular resistance was 109 +/- 56 dyne.s.cm-5 preoperatively,
70 +/- 39 dyne.s.cm-5 postoperatively (p < 0.05), and 70 +/- 36 dyne.s.cm-5 with
exercise in Group 1. The corresponding values for Group 2 were 241 +/- 155
dyne.s.cm-5, 116 +/- 39 dyne.s.cm-5 (p < 0.05), and 104 +/- 47 dyne.s.cm-5. There
was a significant increase in the gradients across the valve prosthesis in both
groups, showing a significant correlation between the gradient at rest and
exercise. No correlation was found between valve prosthesis gradient and
pulmonary pressures. CONCLUSION: Exercise-induced pulmonary hypertension and
abnormal left ventricular filling pressures seem to be a frequent finding
following aortic or mitral valve replacement. Both hemodynamic abnormalities seem
not to be determined by obstruction to flow across the valve prosthesis and may
be concealed, showing nearly normal values at rest but a pathologic response to
physical stress.
PMID- 10680028
TI - Lipid-altering efficacy and safety of simvastatin 80 mg/day: long-term experience
in a large group of patients with hypercholesterolemia. World Wide Expanded Dose
Simvastatin Study Group.
AB - BACKGROUND: Elevated levels of low-density lipoprotein (LDL) cholesterol promote
the development of atherosclerosis and coronary heart disease. HYPOTHESIS:
Simvastatin 80 mg/day will be more effective than simvastatin 40 mg/day at
reducing LDL cholesterol and will be well tolerated. METHODS: Two similar,
randomized, multicenter, controlled, double-blind, parallel-group, 48-week
studies were performed to evaluate the long-term lipid-altering efficacy and
safety of simvastatin 80 mg/day in patients with hypercholesterolemia. One study
conducted in the US enrolled patients meeting the National Cholesterol Education
Program (NCEP) LDL cholesterol criteria for pharmacologic treatment. In the other
multinational study, patients with LDL cholesterol levels > or = 4.2 mmol/l were
enrolled. At 20 centers in the US and 19 countries world-wide, 1,105
hypercholesterolemic patients, while on a lipid-lowering diet, were randomly
assigned at a ratio of 2:3 to receive simvastatin 40 mg (n = 436) or 80 mg (n =
669) once daily for 24 weeks. Those patients completing an initial 24-week base
study were enrolled in a 24-week blinded extension. Patients who had started on
the 80 mg dose in the base study continued on the same dose in the extension,
while those who had started on the 40 mg dose were rerandomized at a 1:1 ratio to
simvastatin 40 or 80 mg in the extension. RESULTS: There was a significant
advantage in the LDL cholesterol-lowering effect of the 80 mg dose compared with
that of the 40 mg dose, which was maintained over the 48 weeks of treatment. The
mean percentage reductions (95% confidence intervals) from baseline in LDL
cholesterol for the 40 and 80 mg groups were 41% (42, 39) and 47% (48, 46),
respectively, for the 24-week base study, and 41% (43, 39) and 46% (47, 45),
respectively, after 48 weeks of treatment (p < 0.001 between groups). Larger
reductions in total cholesterol and triglycerides were also observed with the 80
mg dose compared with the 40 mg dose at Weeks 24 and 48. Both doses were well
tolerated, with close to 95% of patients enrolled completing the entire 48 weeks
of treatment. Myopathy (muscle symptoms plus creatine kinase increase > 10 fold
upper limit of normal) and clinically significant hepatic transaminase increases
(> 3 times the upper limit of normal) occurred infrequently with both doses.
There was no significant difference between the groups in the number of patients
with such increases, although there were more cases for both with the 80 mg dose.
CONCLUSIONS: Compared with the 40 mg dose, simvastatin 80 mg produced greater
reductions in LDL cholesterol, total cholesterol, and triglycerides. Both doses
were well tolerated.
PMID- 10680029
TI - Incidence and significance of profound hypotension during dobutamine stress
echocardiography.
AB - BACKGROUND: Mild hypotension (drops of systolic blood pressure of > or = 20 mmHg)
occurs in 14-38% of dobutamine stress echo (DSE) and carries a good prognosis for
subsequent cardiac events. The incidence and significance of more profound
hypotension (PH) (> or = 50 mmHg) is unknown. HYPOTHESIS: The aim of the study
was to determine the incidence of PH during DSE and its prognosis for subsequent
cardiac events. METHODS: We reviewed 617 DSE performed at our institution between
1992 and 1996 and identified two DSE subgroups. The first group (PH group)
consisted of all patients with PH during DSE. A second group was selected with
baseline characteristics similar to the PH group but without PH during DSE (non
PH group). Follow-up was by a physician chart review and direct telephone
contact. Cardiac event rates were determined for hard [myocardial infarction
(MI), or cardiac death] and soft (angina, congestive heart failure, coronary
angioplasty, or coronary bypass surgery) events occurring after the DSE. RESULTS:
Of the 617 DSE performed, 16 (3%) patients developed PH (PH group) during DSE,
with 13 showing no inducible ischemia. The hard and soft cardiac event rate in
this 13 PH group was 46% (mean follow-up of 28.7 +/- 18 months). Of the non-PH
group, 32 patients had a negative DSE with a coronary event rate of 12.5%.
Profound hypotension correlated with a significantly higher cardiac event rate (p
< 0.02). CONCLUSIONS: The incidence of PH during DSE is low (3%) and appears to
predict a worse prognosis for subsequent cardiac events.
PMID- 10680030
TI - Tricuspid stenosis and regurgitation: Doppler and color flow echocardiography and
cardiac catheterization findings.
PMID- 10680031
TI - Cardiac hemangioma.
PMID- 10680032
TI - Fungal endocarditis of the mitral valve.
PMID- 10680033
TI - Tachycardia-dependent right bundle-branch block with supernormal conduction.
AB - This paper reports the case of a 76-year-old man in whom atrial flutter with
varying atrioventricular block and intermittent right bundle-branch block was
found. This is the first report on tachycardia-dependent right bundle-branch
block associated with supernormal conduction in a case of atrial flutter. When an
impulse is conducted to the ventricles beyond 0.72 s after a QRS complex of right
bundle-branch block configuration, the impulse falls after the abnormally long
effective refractor period of the right bundle branch and passes through the
right bundle branch. When the conducted impulse occurs within 0.72 s after a QRS
complex of right bundle-branch block configuration, the impulse usually falls in
the refractory period and is blocked in the right bundle branch; however, only
when the impulse occurs 0.48 or 0.49 s after that does it fall in the supernormal
period and passes through the right bundle branch. The findings in the present
report strengthen our previous suggestion that the presence of supernormal
conduction plays an important role in the initiation of reentrant ventricular
tachycardia.
PMID- 10680034
TI - Antidromic atrioventricular reentrant tachycardia mimicking ventricular
tachycardia in the setting of previous myocardial infarction.
AB - The differentiation between ventricular tachycardia and broad-complex
supraventricular tachycardia can be extremely difficult, particularly in
emergency situations. We report a case of hemodynamically compromising broad
complex tachycardia in a 63-year-old man. The patient had previously sustained an
anteroseptal myocardial infarction and had subsequently undergone coronary artery
bypass surgery because of triple-vessel coronary artery disease. Intravenous
treatment with ajmalin terminated the tachycardia and revealed preexcited QRS
complexes compatible with the presence of a left-sided atrioventricular accessory
pathway. An antidromic atrioventricular reentrant tachycardia (identical to the
clinical tachycardia) was induced during an electrophysiologic study. In
conclusion, there are several causes of broad-complex tachycardia, even in
patients with previous myocardial infarction, and, where doubt exists,
electrophysiologic studies should be performed.
PMID- 10680035
TI - John B. Barlow: master clinician and compleat cardiologist.
PMID- 10680036
TI - Introduction: Expanding the horizons in unstable coronary artery disease.
PMID- 10680037
TI - Can we differentiate the low-molecular-weight heparins?
AB - The low-molecular-weight heparins (LMWHs) have a number of therapeutic
advantages, relative to standard unfractionated heparin (UFH). They are readily
bioavailable when injected subcutaneously and can be given in fixed doses,
allowing for far simpler administration. Several LMWHs are now commercially
available, each demonstrating different physical and chemical properties and
different activities in animal models of anticoagulation or hemorrhage. In
clinical comparisons with placebo in the treatment of unstable coronary artery
disease (UCAD), the LMWHs dalteparin sodium and nadroparin calcium have
demonstrated good anticoagulant efficacy. In comparisons with UFH, on the other
hand, only enoxaparin has shown superior anticoagulant activity, as reported in
the results of the Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-wave
Coronary Events (ESSENCE) and Thrombolysis In Myocardial Infarction (TIMI) 11B
trials. However, close scrutiny of the methodology of the clinical trials in UCAD
reveals considerable differences in study designs, dosage regimens, duration of
administration of active treatments, and the timing and definition of endpoints.
Therefore, it would not be scientifically sound to compare results with the
different LMWHs based on the current available studies. It is also not possible
to draw any conclusions with regard to the relative efficacy of the different
LMWHs, since there are no properly-sized comparative data between dalteparin
sodium, enoxaparin sodium, and nadroparin calcium.
PMID- 10680038
TI - Acute management--how should we intervene?
AB - A crucial question in the acute management of the patient with unstable coronary
artery disease (UCAD) is whether to carry out early intervention, performing
angiography soon after presentation and following this with revascularization
where appropriate, or whether to follow a noninvasive medical strategy as far as
possible unless symptoms necessitate intervention. The body of literature
addressing this question is sparse, but the recent Fast Revascularization during
InStability in Coronary artery disease (FRISC II) study has provided new insights
into the problem. Using a factorial design to randomize patients to invasive or
noninvasive management strategies, and to short- or long-term treatment with the
low-molecular-weight heparin (LMWH) dalteparin sodium (Fragmin), it was shown in
FRISC II that early invasive treatment (within 7 days), when combined with
optimal medical pretreatment with dalteparin sodium, aspirin, and appropriate
antianginal medication, is associated with improved clinical outcomes, relative
to a "watchful waiting" approach based on noninvasive therapy. Thus, an early
invasive approach following aggressive medical pretreatment should be the
preferred strategy for patients with UCAD who present with signs of ischemia on
the electrocardiogram or raised biochemical markers of myocardial damage at
admission.
PMID- 10680039
TI - Long-term management--the way forward?
AB - The mainstay of treatment for unstable coronary artery disease (UCAD) currently
consists of antithrombotic therapy with aspirin plus unfractionated heparin
(UFH), together with anti-ischemic treatment with beta blockers and nitrates.
Recently, there has been a trend toward replacement of UFH with low-molecular
weight heparins (LMWHs), since these products offer significant advantages over
the parent compound. Several lines of evidence suggest that prolongation of
treatment with LMWHs beyond the acute phase may be appropriate in patients with
UCAD. The Fragmin and Fast Revascularization during InStability in Coronary
artery disease (FRISC II) study was designed to evaluate this hypothesis using
the LMWH dalteparin sodium (Fragmin). A factorial design was used to randomize
patients enrolled in the FRISC II study to an invasive or noninvasive management
strategy, and to treatment with dalteparin sodium or placebo. Treatment with
dalteparin sodium significantly reduced incidences of death and/or myocardial
infarction (MI) during the first months of treatment (the reduction in the
relative risk of double endpoint events was statistically significant at 47.0% at
1 month, and remained so at 2 months, but was no longer statistically significant
at the 3-month assessment). However, risk, as defined by the triple endpoint of
death, MI, and revascularization, was significantly lower (13.0% relative risk
reduction) at 3-month follow-up in the treatment group randomized to dalteparin
sodium than among patients receiving placebo. In patients in whom
revascularization procedures were carried out, the risk of new, postprocedural
events was low in both the placebo and dalteparin sodium arms. Thus, dalteparin
sodium appears to protect patients from cardiac events until they undergo
invasive procedures, and it can therefore be used as a bridge to
revascularization.
PMID- 10680040
TI - Targeting treatment for optimal outcome.
AB - Rapid assessment of patients presenting with acute chest pain is essential, in
order to distinguish between those who have a life-threatening condition, such as
myocardial infarction or unstable angina, and the substantial proportion who do
not have an acute coronary syndrome. It is thus of vital importance that reliable
techniques are available to facilitate rapid risk stratification, as an aid to
both clinical diagnosis and management strategy decisions. Assessments based on
clinical findings, electrocardiographic monitoring, symptom-limited exercise
testing, and biochemical marker measurements, used either singly or in various
combinations, can fulfill this role. The present paper reviews some of the recent
data that demonstrate the value of these techniques. Very few studies allow
conclusions to be drawn about optimal treatment strategies in relation to groups
stratified according to prognostic markers, and the question of whether intense
medical treatment or early invasive intervention is most beneficial is one that
clinical trials have yet to address adequately. In the recently completed Fragmin
and Fast Revascularization during InStability in Coronary artery disease (FRISC
II) study, comparisons were made of clinical outcomes achieved with early
invasive versus noninvasive (i.e., medical) management strategies, and with short
term versus prolonged anticoagulation with dalteparin sodium (Fragmin), in
patients with unstable coronary artery disease. All study participants underwent
symptom-limited exercise testing and provided blood sample for measurements of
biochemical markers; continuous electrocardiography monitoring and
echocardiography were also performed in a high proportion of patients. Data from
the FRISC II trial thus shed further light on the issue of risk stratification
and its use to determine optimal treatment strategies.
PMID- 10680041
TI - Regulation of macrophage gene expression by peroxisome-proliferator-activated
receptor gamma: implications for cardiovascular disease.
AB - The peroxisome-proliferator-activated receptor gamma is a member of the nuclear
receptor superfamily that functions as a key transcriptional regulator of cell
differentiation and lipid metabolism. In addition, peroxisome-proliferator
activated receptor gamma is now recognized to be the biological receptor for the
thiazolidinedione class of antidiabetic drugs, which includes troglitazone and
rosiglitazone. Recent evidence indicates that peroxisome-proliferator-activated
receptor gamma is expressed at high levels in macrophages, including the foam
cells of atherosclerotic lesions. Oxidized low-density lipoprotein, which plays a
central role in lesion development, can activate peroxisome-proliferator
activated receptor gamma by providing the cell with oxidized fatty acid ligands
of the receptor. The elucidation of a peroxisome-proliferator-activated receptor
gamma signalling pathway in macrophages provides a mechanism by which oxidized
lipids may directly regulate gene expression in the context of the
atherosclerotic lesions. A number of potential target genes for peroxisome
proliferator-activated receptor gamma in these cells have been identified. Some,
such as the type B scavenger receptor CD36 are induced by peroxisome-proliferator
activated receptor gamma ligands, whereas others, such as scavenger receptor type
A, inducible nitric oxide synthetase and certain cytokines, are repressed. Given
the widespread clinical use of thiazolidinediones, it is important to consider
the influence of these drugs on the risk of atherosclerosis. The net effect of
peroxisome-proliferator-activated receptor gamma ligands on the atherogenic
process is likely to reflect a balance between local effects in the artery wall
and systemic effects on lipid metabolism.
PMID- 10680042
TI - Influence of the HDL receptor SR-BI on atherosclerosis.
AB - The scavenger receptor class B, type I (SR-BI) is an HDL receptor that mediates
selective cholesterol uptake from HDL to cells. In rodents, SR-BI has a critical
influence on plasma HDL-cholesterol concentration and structure, the delivery of
cholesterol to steroidogenic tissues, female fertility, and biliary cholesterol
concentration. SR-BI can also serve as a receptor for non-HDL lipoproteins and
appears to play an important role in reverse cholesterol transport. Recent
studies involving the manipulation of SR-BI expression in mice, either using
adenovirus-mediated or transgenic hepatic overexpression or using homologous
recombination for complete functional ablation, indicate that the expression of
SR-BI protects against atherosclerosis. If SR-BI has a similar activity in
humans, it may become an attractive target for therapeutic intervention.
PMID- 10680043
TI - Pathology of in-stent restenosis.
AB - The process of in-stent restenosis parallels wound healing responses. Stent
deployment results in early thrombus deposition and acute inflammation,
granulation tissue development, and ultimately smooth muscle cell proliferation
and extracellular matrix synthesis. The severity of arterial injury during stent
placement correlates with increased inflammation and late neointimal growth.
These pathological findings provide useful targets for therapies aimed at
reducing the incidence of in-stent restenosis.
PMID- 10680044
TI - Smooth muscle cell phenotypes in atherosclerotic lesions.
AB - Recently, there has been a dramatic change in the way we think about the role of
vascular smooth muscle cells in atherosclerosis, and it is now generally accepted
that a dearth of vascular smooth muscle cells in an atherosclerotic plaque is a
detrimental feature of the disease. Indeed, it is now recognized that the
phenotypes of vascular smooth muscle cells within a plaque dictate its features,
progression and stability. Therefore an understanding of the processes that
generate and regulate vascular smooth muscle cell heterogeneity are of critical
importance for future therapeutic advancement in the treatment of
atherosclerosis.
PMID- 10680045
TI - Functional genomics and DNA array techniques in atherosclerosis research.
AB - DNA arrays are revolutionizing the analysis of gene expression and single
nucleotide polymorphisms of genomic DNA. Currently, the expression of 10-15% of
human genes can be analysed simultaneously in a single experiment using cDNA or
oligonucleotide-based format of DNA array. Alternatively, smaller DNA arrays with
a limited number of selected genes, such as cytokines, growth factors or
transcription factors, can be used. In concordance with Human Genome Project,
after a few years, the DNA arrays will allow the analysis of expression of the
whole human genome and will have a great impact on basic research, drug
development and diagnostics. It is important to characterise mechanisms of
atherosclerosis-related diseases at the level of gene expression so that new
therapeutic strategies can be identified. With the aid of DNA array it is
possible to identify multiple, simultaneous, transcriptional events that
ameliorate or contribute to atherogenesis. The results are non-physical maps of
the function, hierarchy and interactions of genetic programs. In this review we
focus on DNA array technology and its applications in atherosclerosis research.
PMID- 10680046
TI - Clinical lipidology at the end of the millennium.
PMID- 10680047
TI - Modification of coronary artery disease progression by cholesterol-lowering
therapy: the angiographic studies.
AB - Large randomized placebo-controlled trials have demonstrated that cholesterol
lowering with statin therapy reduces the incidence of adverse cardiac events.
Smaller angiographic studies have shown that coronary artery disease progression
can be slowed and, in some cases, reversed by cholesterol-lowering interventions.
These anatomical changes, however, are small and occur too slowly to account for
the early clinical benefit. Current evidence suggests that plaque stabilization
is the most important mechanism, by which cholesterol-lowering therapy reduces
both the incidence of adverse cardiac events and coronary artery disease
progression.
PMID- 10680048
TI - Effects of statins on carotid disease and stroke.
AB - The results of recent trials indicate that statin treatment reduces not only the
risk of coronary heart disease, but also the risk of stroke, in patients with
existing heart disease. The need for the treatment of such patients is now
generally recognized. Mechanisms for risk reduction include the retardation of
plaque progression, plaque stabilization, and reducing the risk of coronary
events. Questions remain regarding the discrepancy between epidemiological data
and statin trials data, the precise mechanism of action of statins, and their
role in the prevention of recurrent stroke in individuals who have experienced a
previous stroke or transient ischemic attack but are free of coronary disease.
PMID- 10680049
TI - Low-density lipoprotein-independent effects of statins.
AB - Statins have pleiotropic properties that complement their cholesterol-lowering
effects. These properties may partly account for their established benefit in the
prevention of coronary artery disease beyond the reduction of LDL-cholesterol
levels. The most widely recognized properties are reviewed here. They include:
(i) nitric oxide-mediated improvement of endothelial dysfunction and upregulation
of endothelin-1 expression; (ii) antioxidant effects; (iii) anti-inflammatory
properties; (iv) inhibition of cell proliferation with anticarcinogenic actions
in animals; (v) stabilization of atherosclerotic plaques; (vi) anticoagulant
effects; and (vii) inhibition of graft rejection after heart and kidney
transplantation. As advances are made in our knowledge, new properties are
steadily being uncovered. Pleiotropic effects are currently being given
consideration when instituting combination therapy for patients at high
cardiovascular risk. Some pleiotropic effects are negative, and may account for
occasional untoward drug interactions. For many of these new properties, the
clinical relevance has not been established. The challenge for the future will be
to design and carry out appropriate clinical trials to establish their relative
importance in the prevention of coronary artery disease.
PMID- 10680050
TI - Fibrates, dyslipoproteinaemia and cardiovascular disease.
AB - Recent epidemiological data have reaffirmed that elevated plasma triglyceride and
low HDL-cholesterol levels are important risk factors for atherosclerotic
vascular disease. The rationale for the clinical use of fibric acid derivatives,
which are designed to correct this metabolic nexus, is now on firmer ground. The
mechanism of action of fibrates on lipoprotein metabolism has recently been
elucidated at the molecular level and involves the activation of peroxisome
proliferator-activated receptor-alpha 1 in the liver, with the net effect of
improving the plasma transport rates of several lipoproteins. Other potential
anti-atherothrombotic effects include the inhibition of coagulation and
enhancement of fibrinolysis, as well as the inhibition of inflammatory mediators
involved in atherogenesis. These consequences probably underpin the favourable
effects of fibrates seen in recent angiographic and clinical trials. Two
important clinical trials on the effect of gemfibrozil (Veterans Administration
HDL-Cholesterol Intervention Trial) and bezafibrate (Bezafibrate Infarction
Prevention Study) have recently been completed in subjects with elevated
triglyceride, low HDL and normal or near-normal LDL-cholesterol levels. The
results testify to the efficacy of these agents in decreasing the incidence of
cardiovascular events, particularly in patients with multiple risk factors and
plasma triglyceride levels of over 2.2 mmol/l. The findings of these trials are
compared with the statin-based Air Force/Texas Coronary Atherosclerosis
Prevention Study, with a recommendation that future studies in appropriately
selected patients should examine the synergistic effect of the fibrate/statin
combination. The absolute risk reduction in the incidence of coronary events in
the Veterans Administration-HDL-Cholesterol Intervention Trial compares
favourably with the statin trials. The therapeutic aspects of the efficacy and
safety of fibrates are reviewed. Besides primary mixed hyperlipidaemias,
particular indications for the clinical use of fibrates include type 2 diabetes,
the metabolic syndrome and renal insufficiency. The St Mary's, Ealing, Northwick
Park Diabetes Cardiovascular Disease Prevention Study has suggested that fibrates
may decrease the incidence of coronary events in type 2 diabetes, but this
hypothesis will be more extensively tested in the Diabetes Atherosclerosis
Intervention Study, Fenofibrate in Event Lowering in Diabetes Study and Lipids in
Diabetes Study projects. Although significant new knowledge has accrued over the
past few years concerning the fundamental and clinical aspects of fibrates, the
success of these agents in clinical practice depends on the availability of
methods for assessing cardiovascular risk as well as on treatment guidelines,
which as presently designed and recommended may be inaccurate and suboptimal.
PMID- 10680051
TI - Non-pharmacological lowering of low-density lipoprotein by apheresis and surgical
techniques.
AB - In the past year, new data have appeared on the long-term benefits of low-density
lipoprotein apheresis in severely hypercholesterolemic patients who are
refractory to lipid-lowering drug therapy. Such data are critical for clinical
decision-making, because they confirm the hypothesis that the dramatic reduction
in low-density lipoprotein made possible by this technique produces clear-cut
clinical benefits. Because of its efficacy and low incidence of side-effects,
apheresis for severe drug-refractory hypercholesterolemia has superseded surgical
approaches, such as liver transplantation or ileal bypass.
PMID- 10680052
TI - Hormone replacement therapy and cardiovascular disease.
AB - This year's work on hormone replacement therapy (HRT) and cardiovascular disease
has been remarkable for the publication of the first randomised controlled trial
of HRT use, the Heart Estrogen Replacement Study (HERS). The findings go against
not only the trend of previous observational epidemiological studies, but also
against findings in the very many studies which have previously shown and
continue to show this year a beneficial effect of HRT on a large variety of
cardiovascular risk factors, including endothelial function, here reviewed. The
aspect of the effect of HRT on clotting variables is clearly crucial given the
increased risk of venous thrombosis, and also increased number of cardiac events
in the first 4 months of the HERS. Prothrombotic factors increase with age in
women, and HRT alters these, particularly fibrinogen, factor VII, and PAI (less
change with transdermal HRT) and antithrombin III. In normal women therefore the
balance should be towards fibrinolysis rather than coagulation. Work has been
presented in abstract for clarifying the effects of HRT on coagulation markers
and grasping the problem of differences according to its route of administration.
The full publications on this work are expected shortly. We are still awaiting
evidence from randomized controlled trials of HRT in primary prevention; one is
now recruited but will not report until 2005.
PMID- 10680053
TI - Dietary and pharmacological antioxidants in atherosclerosis.
AB - Antioxidants that inhibit LDL oxidation are thought to be potential anti
atherogenic compounds. The results of major human randomized trials with
antioxidants have, however, been disappointing, except for probucol, which
consistently inhibits restenosis. Similarly, animal intervention studies show
that antioxidants do not generally inhibit atherosclerosis, although some
compounds provide protection. Direct evidence for the oxidation of LDL causing
atherosclerosis is needed. This article summarizes results from antioxidant
intervention studies, and highlights some of the key issues that need to be
addressed to link biochemical changes in the arterial wall more directly to the
oxidation theory of atherosclerosis.
PMID- 10680054
TI - Bibliography. Current world literature. Atherosclerosis: cell biology and
lipoproteins.
PMID- 10680055
TI - Bibliography. Current world literature. Therapy and clinical trials.
PMID- 10680056
TI - Nutrition.
PMID- 10680057
TI - Genetics and molecular biology.
PMID- 10680058
TI - Lipid metabolism.
PMID- 10680059
TI - Hyperlipidaemia and cardiovascular disease.
PMID- 10680060
TI - What's sex got to do with it?
PMID- 10680061
TI - Therapy and clinical trial.
PMID- 10680062
TI - Monoclonal antibody against tetrahydrocannabinolic acid distinguishes Cannabis
sativa samples from different plant species.
AB - The cross-reaction of anti-delta 1-THCA MAb against other cannabinoids was very
wide. However, other naturally occurring and synthetic phenolics including opium
alkaloids did not react to the MAb. Using this ELISA, this paper reports
application of the competitive ELISA for detection of marijuana samples. The
ELISA described here was very sensitive to the ether extracts of marijuana
samples when compared to those of other plants. The assay provided a sensitive
method useful for the judge of marijuana samples.
PMID- 10680063
TI - Screening experiments of ecstasy street samples using near infrared spectroscopy.
AB - Twelve different sets of confiscated ecstasy samples were analysed applying both
near infrared spectroscopy in reflectance mode (1100-2500 nm) and high
performance liquid chromatography (HPLC). The sets showed a large variance in
composition. A calibration data set was generated based on the theory of
factorial designs. It contained 221 N-methyl-3,4-methylenedioxyamphetamine (MDMA)
samples, 167 N-ethyl-3,4-methylenedioxyamphetamine (MDE), 111 amphetamine and 106
samples without a controlled substance, which will be called placebo samples
thereafter. From this data set, PLS-1 models were calculated and were
successfully applied for validation of various external laboratory test sets. The
transferability of these results to confiscated tablets is demonstrated here. It
is shown that differentiation into placebo, amphetamine and ecstasy samples is
possible. Analysis of intact tablets is practicable. However, more reliable
results are obtained from pulverised samples. This is due to ill-defined
production procedures. The use of mathematically pretreated spectra improves the
prediction quality of all the PLS-1 models studied. It is possible to improve
discrimination between MDE and MDMA with the help of a second model based on raw
spectra. Alternative strategies are briefly discussed.
PMID- 10680064
TI - Origin of blood ethanol in decomposed bodies.
AB - Problems related to blood contamination by other postmortem fluids in decomposed
bodies (DB) make the interpretation of medicolegal blood alcohol levels (B EtOH)
a very difficult task. So the aim of this paper is to show the utilization of
vitreous humor (VH) as the biological fluid for an unequivocal determination of
ethanol origin in DB for forensic purposes. Alcohol was determined in VH, blood
(chest fluid-CF) and urine (Ur) collected from 27 DB in different states of
putrefaction. A simple head-space gas-chromatographic method was used. In fifteen
cases alcohol was found to be of endogenous production due to its absence in VH.
In the twelve remainders, alcohol was detected in VH and CF in an atypical
distribution. Examining the reliable scene and historical information together
with the analytical data, ethanol origin in these cases was classified:
endogenous production (3 cases), ingested (2 cases), both (2 cases), contaminated
plus endogenous production (3 cases) and unable to determine (2 cases). According
to the results obtained it was possible to conclude that alcohol analysis in VH
is fundamental for determining the origin of ethanol detected in CF of DB.
PMID- 10680065
TI - Robustness of the Y STRs DYS19, DYS389 I and II, DYS390 and DYS393: optimization
of a PCR pentaplex.
AB - Various technical methods were investigated with the aim of developing a
multiplex system to amplify five Y-chromosome STR loci in the same PCR reaction:
DYS393, DYS19, DYS390, DYS389 I and DYS389 II. A sequenced allelic ladder was
constructed with previously sequenced alleles including the most common ones. A
number of reamplification conditions of the allelic ladders were tested. The
pentaplex was evaluated for typing using two different platforms (ABI and ALF)
with promising results. However, in degraded samples non-specific artifacts were
observed in the DYS393 system in the same range of sizes as the real alleles.
This system can also be typed in females under relatively low stringency
conditions in the PCR amplification, making this system prone to errors in
critical samples. This lack of specificity can be reduced by increasing the
stringency of the PCR conditions. The DYS19 ladder cannot be reamplified as
stutters appear after a few reamplifications. These stutters are probably due to
a 2 bp slippage induced by the presence of a TA repeat stretch in the PCR
amplified fragments. Non-specific products were also noted in the DYS389 I and
DYS389 II amplification, although out of the range of other alleles in this
pentaplex. This newly constructed pentaplex has proved to be very useful in
population genetic studies because all five Y STR markers can be loaded in the
same lane of a gel with other Y STR singleplex or multiplexes. The usefulness of
Y-chromosome STRs in criminal casework is especially evident in analyzing
azoospermic individuals.
PMID- 10680066
TI - Drugged driving in the Nordic countries--a comparative study between five
countries.
AB - The purpose of this study was to compare whether the high incidence of drugged
driving in Norway was different to that in the other Nordic countries. All blood
samples received by Nordic forensic institutes during one week in 1996, from
drivers suspected by the police of driving under the influence (Denmark: n = 255,
Finland: n = 270, Iceland: n = 40, Sweden: n = 86, Norway: n = 149), were
analysed for alcohol and drugs (benzodiazepines, cannabinoids, amphetamines,
cocaine, opiates and a number of antidepressant drugs) independent of the primary
suspicion, and using the same analytical cut-off levels at the different
institutes. The primary suspicion was directed towards drugs in more than 40% of
the Norwegian cases, drugs were detected in more than 70% of these samples. In
only 0-3% of the cases from Denmark, Finland and Iceland, were drugs suspected,
while the corresponding frequency for Sweden was 17%. However, evidential breath
analyses were used for about three-quarters of the Swedish drivers suspected to
be influenced by alcohol. Blood alcohol concentrations (BAC's) below the legal
limits were found in 32, 18 and 2% of the Norwegian, Icelandic and Finnish cases,
respectively (BAC < 0.05%), in 10% of the Danish cases (BAC < 0.08%) and in 20%
of the Swedish cases (BAC < 0.02%). Drugs were most frequently found in the
Norwegian and Swedish cases with no alcohol (80-83%). Similar frequencies of
drugs in samples with BAC's above the legal limits (19-22%), were obtained for
all countries. Benzodiazepines, tetrahydrocannabinol and amphetamine represented
the most commonly detected drugs. Our results show that differences between
Norway and other Nordic countries with regard to drugs and driving, are connected
to the selection criteria made by the police and with more focus on drugged
driving in Norway.
PMID- 10680067
TI - Colchicine poisoning by accidental ingestion of meadow saffron (Colchicum
autumnale): pathological and medicolegal aspects.
AB - Although intoxications with colchicine, the alkaloid of Colchicum autumnale
(meadow saffron), are well known, in most cases the intoxications are evoked by
oral or parenteral preparations traditionally used as medication against gout.
The accidental ingestion of Colchicum autumnale, on the other hand, is a rare
event and has to our knowledge only twice been described in detail. We report a
further case in which two persons confused this highly poisonous plant with wild
garlic (Allium ursinum), a popular spice in the Central European cuisine. While
one person merely complained about a 3-day episode of nausea, vomiting and watery
diarrhea, the second person died of multi-organ system derangements 48 h after
the ingestion of the colchicum leaves. At autopsy hemorrhagic lung oedema,
hypocellular bonemarrow, centrilobular fatty necrosis of the liver and necrosis
of the proximal convoluted tubuli of the kidneys were observed. A colchicine
concentration of 7.5 micrograms/ml was found in the bile whereas no substance was
detected in the postmortem blood.
PMID- 10680068
TI - Cancer and aging. An evolving panorama.
AB - This article illustrates how the nosology of cancer evolves with the patient's
age. If the current trends are maintained, 70% of all neoplasms will occur in
persons aged 65 years and over by the year 2020, leading to increased cancer
related morbidity among older persons. Cancer control in the older person
involves chemoprevention, early diagnosis, and timely and effective treatment
that entails both antineoplastic therapy and symptom management. These
interventions must be individualized based on a multidimensional assessment that
can predict life expectancy and treatment complications and that may evaluate the
quality of life of the older person. This article suggests a number of
interventions that may improve cancer control in the aged. Public education is
needed to illustrate the benefits of health maintenance and early detection of
cancer even among older individuals, to create realistic expectations, and to
heighten awareness of early symptoms and signs of cancer. Professional education
is needed to train students and practitioners in the evaluation and management of
the older person. Of special interest is the current initiative of the Hartford
Foundation offering combined fellowships in oncology and geriatrics and
incorporating principles of geriatric medicine in medical specialty training.
Prudent pharmacologic principles must be followed in managing older persons with
cytotoxic chemotherapy. These principles include adjusting the dose according to
the patient's renal function, using epoietin to maintain hemoglobin levels of 12
g/dL or more, and using hemopoietic growth factors in persons aged 70 years and
older receiving cytotoxic chemotherapy of moderate toxicity (e.g., CHOP). To
assure uniformity of data, a cooperative oncology group should formulate a
geriatric package outlining a common plan for evaluating function and
comorbidity. This article also suggests several important areas of research
items: Molecular interactions of age and cancer Host-tumor interactions in the
older tumor host Chemoprevention of cancer and aging Laboratory evaluation of
aging Development of shorter forms of geriatric assessment Management of the
frail cancer patients Clinical trials of tumor-specific issues.
PMID- 10680069
TI - Aging and cancer in America. Demographic and epidemiologic perspectives.
AB - It has been stated in this article and elsewhere that cancer patients aged 65
years and older deserve special attention as a target group for research efforts
across the cancer-control spectrum. The available data show that the
vulnerability of older persons to cancer is unmistakable. Clinicians will be
treating more older patients as the nation ages. The future needs of this segment
of the population must be anticipated. In this context, the following generic
treatment questions are pertinent. What are the peculiarities of the aged host of
which clinicians must be aware in evaluating the older cancer patient? Do various
forms of cancer present differently in the elderly? How can be complications
caused by the multiple pathologies inherent in the older patient be anticipated?
What are the potential hazards and limitations of surgery, radiotherapy, and
chemotherapy for older persons with cancer? What is known regarding increased
risk of adverse reactions to medications, drugs, and interaction of drugs in
older patients? The surveillance data and population estimates and projections
presented in this article illustrate the extent of the problems of cancer in the
elderly at the macro level. For the individual patient, the special knowledge of
aging individuals and their health status based on geriatric medicine and
gerontology that has been accumulating for the past several decades needs to be
incorporated into the oncology armamentarium that has developed during the same
period. The information and expertise from both fields must converge, and new
knowledge must be developed at the aging/cancer interface and applied for the
optimal treatment of cancer in the elderly.
PMID- 10680070
TI - Molecular interactions of cancer and age.
AB - The authors believe that the aging process--the loss of youthful resilience--is
caused by the decline of many hormones. By restoring these hormone levels, the
decay associated with old age can be eliminated and in some cases, perhaps
reversed. The hormones that naturally occur in the body should be replenished
through a medically sound regimen. The hormones must work together. The data
indicate that aging occurs at two levels: systemically and cellularly. Systemic
controls regulate the rates of intracellular enzymatic processes that accelerate
to protect against aging.
PMID- 10680071
TI - Hematopoiesis and cytokines. Relevance to cancer and aging.
AB - Impaired hematopoiesis and dysregulated cytokine expression have important
implications for cancer in the elderly. In aged people, hematopoiesis is
dysregulated and becomes paradoxically down-modulated under periods of increased
hematopoietic demand. This down-modulation may explain, at least in part, the
increased incidence of anemia in the elderly, although the cause of anemia can
usually be identified in these patients and frequently reversed with targeted
therapy. An age-associated decrease in the expression of interleukin-2 may
contribute to impaired cellular immunity. Additionally, the increased interleukin
6 production frequently found in the elderly may participate in promoting the
survival and proliferation of malignant myeloma and in inducing resistance by
myeloma cells to therapies that act through apoptosis. Dysregulation of the
expression of these and other cytokines may be a mechanism contributing to age
related impairment of the hematopoietic response, the genesis and therapeutic
resistance of specific malignancies, and cancer cachexia.
PMID- 10680072
TI - Assessment of the older cancer patient.
AB - The correct assessment of a cancer patient is a key step in the treatment
process. In older people, this assessment entails not only the patient's basic
medical history and the standard cancer staging, but also much more comprehensive
evaluation of the various facets of the patient's health and environment that may
interfere with his or her therapy. Patient fitness for elective surgery,
radiation therapy, and chemotherapy must be considered. Geriatricians have
defined the relevant aspects of the general evaluation of the older person, and
now this work is being adapted to cancer patients. This article reviews the
various aspects of a comprehensive assessment applicable to the cancer patient in
settings such as academic oncology programs, cooperative group studies, and
private oncology practice.
PMID- 10680073
TI - Qualitative research for the study of cancer and age.
AB - Qualitiative research emphasizes identification, illumination, and understanding
of phenomena, the meaning and theory behind which are unpresumed by the
investigator. Although quantitative techniques are used to test predetermined
hypotheses, qualitative techniques are used to generate hypotheses. Qualitative
techniques have only begun to be used in medical research in the past decade but
are especially useful in exploring content areas about which little is known and
in eliciting and understanding the patient's perspective. Despite the aging of
the United States population, the cancer illness experience has not been well
studied in older patients. Because communication preferences, treatment decision
making styles, psychosocial issues, and the illness experience itself may be
significantly different for older persons diagnosed with cancer than for younger
persons, qualitative research techniques can be used to identify those
differences critical to the effective health care of this burgeoning population.
PMID- 10680074
TI - Cancer screening in the elderly population.
AB - This article reviews the current state of knowledge regarding cancer screening in
the geriatric population. Care of the elderly requires knowledge of underlying
physiologic changes, comorbidities, quality-of-life factors, and life
expectancies. There is always the danger that ageism may prevent elderly cancer
patients from receiving the proper treatment. On the other hand, overzealous
treatment can lead to adverse results if elderly patients are not properly
targeted based on current evidence of the benefits and risks of specific
screening practices.
PMID- 10680075
TI - Chemoprevention of breast cancer in the older patient.
AB - Age is the most important risk factor for the development of breast cancer. The
risk of breast cancer continues to increase in American women until the age of 80
years. A family history of breast cancer helps identify those who possibly have
the highest risk of developing breast cancer; however, most women who develop
breast cancer do not have a first-degree relative with a history of breast
cancer. Currently, the Gail model is a commonly used model to identify risk, and
this model has now been validated in several populations of women undergoing
screening for breast cancer. The first large-scale breast cancer prevention trial
investigating the preventive effects of tamoxifen has demonstrated a decrease in
the development of breast cancer by almost 50% in the women in the tamoxifen
treatment arm as compared with those receiving placebo. The NSABP P-1 trial was
the largest of the three tamoxifen breast cancer prevention trials and had the
greatest power to detect a difference between the two treatment groups in breast
cancer events. This trial also included the largest percentage of postmenopausal
women. It is unclear why the Italian and Royal Marsden Hospital trials had
negative results regarding the preventive effects of tamoxifen. These two trials
were strikingly different from the NSABP P-1 trial, however, and they included a
different population of women. The issues surrounding the use of HRT for
treatment of hot flashes in the Italian and Royal Marsden Hospital trials adds to
the controversy concerning the negative results of these trials. The new SERM,
raloxifene, has shown promise in preliminary studies as a preventive agent for
breast cancer. The STAR trial will open soon and will evaluate the efficacy of
raloxifene in preventing breast cancer in a prospective fashion, comparing its
efficacy with tamoxifen treatment. Other endpoints will evaluate side effects
such as menopausal symptoms, endometrial cancer, thromboembolic events, and
benefits regarding serum lipids and incidence of osteoporotic bone fractures. The
development of SERMs results from an understanding of novel mechanisms of ER
modulation and allows targeting for favorable effects in specific tissues. The
challenge is to develop an ideal SERM that is effective in preventing breast
cancer and does not increase the risk of endometrial cancer, while providing
beneficial estrogenic effects on serum lipids and bone mineral density changes.
Estrogen receptor-mediated intracellular processes are complex. There are at
least two different types of estrogen receptors. The alpha receptors predominate
in the breast and uterus, and the beta receptors predominate in the bone and
blood vessels. Many proteins also interact with these receptors as co-activators
or co-repressors. Transcription-activating factors modulate the effects of
estrogen on its target genes. Future prevention strategies may use a combined
targeted approach to inhibit ER-mediated cancer progression pathways. The
retinoids are under investigation in prevention studies for a multitude of
cancers, because they have been shown to inhibit cellular proliferation and to
induce cellular differentiation. The retinoid 4HPR was selected for use in breast
cancer prevention studies because of its low toxicity profile and prevention
efficacy in preclinical studies. It is now being used in combination with
tamoxifin in a phase II breast cancer prevention trial. Multiple surrogate
endpoint biomarkers are being measured before and after treatment, including
measurement of serum IGF-I levels. Future directions in breast cancer prevention
include the development of more potent hormonal therapies that completely inhibit
ER-mediated cancer progression and, ultimately, multitargeted therapies involving
agents that work synergistically.
PMID- 10680076
TI - Radiation therapy of the older patient.
AB - Radiotherapy has a major role in the multidisciplinary approach to cancer
therapy. It is widely used for curative and palliative treatment of cancer
involving various sites. Radiotherapy is of particular benefit to older and frail
cancer patients as an alternative to surgery and to systemic therapy. The
available data on the sensitivity of normal tissues to radiotherapy in elderly
patients strongly suggest that older patients with good functional status
tolerate radiotherapy as well as younger patients and have comparable tumor
response and survival rates. Aggressive radiotherapy should not be withheld from
older patients because of chronological age alone.
PMID- 10680077
TI - Cancer surgery in the elderly.
AB - The incidence of most cancers increases with age. Although the risk for surgery
increases in elderly patients who have comorbidities, evaluations of risk can
allow interventions that may decrease morbidity and mortality. Appropriate
treatments should be offered to the elderly until studies demonstrate the elderly
can safely be managed differently from younger patients. The elderly should not
be denied adequate treatment simply because of age.
PMID- 10680078
TI - Antineoplastic chemotherapy of the older cancer patient.
AB - Cancer chemotherapy may be effective and safe in older patients if some proper
provisions are made. Doses of chemotherapy should be adjusted to the patient's
glomerular filtration rate, and his or her hemoglobin should be maintained for
the duration of the therapy. For patients who are 70 years of age or older and
who are receiving moderately toxic chemotherapy, growth factors should be used.
The risk of mucositis increases with the age of the patient, so it is important
to treat it aggressively at the first signs of the complication.
PMID- 10680079
TI - Breast cancer and aging. Clinical interactions.
AB - The incidence and mortality rates of breast cancer increase with age. As the
geriatric population grows, the number of breast cancer cases will reach epidemic
proportions. The number of coexisting medical conditions also increases with
advancing age. The presence and severity of comorbid conditions influences an
individual's ability to tolerate procedures and treatments and must be considered
in making disease-management decisions. Screening mammography can potentially
save lives in older women. Women whose life expectancy exceeds 5 years should
continue annual screening mammography. Choices for local definitive therapy,
systemic adjuvant therapy, and treatment of metastatic disease should be based on
patient preference and ability to tolerate the planned procedure. In general,
otherwise healthy older women should be offered the same treatment options given
to younger, postmenopausal women. Alternative, less aggressive, or nonstandard
approaches are warranted in women whose life expectancy is limited or who are
unable or unwilling to undergo standard management procedures.
PMID- 10680080
TI - Cancer in the frail patient. A coming epidemic.
AB - With the aging of the population, frailty has emerged as a new clinical entity.
The frail person has exhausted any functional reserve. Current criteria for the
recognition of frailty include age of over 85 years, dependence in one or more
activities of daily living, three or more comorbid conditions, and the presence
of one or more geriatric syndromes. It is calculated that there are approximately
6 million frail patients in the United States and approximately 400,000 of them
have cancer. Management of cancer in the frail person is mainly comprised of
palliation, which may include some forms of chemotherapy, such as navelbine,
gemcitabine, or low-dose taxanes.
PMID- 10680081
TI - Acute myelogenous leukemia and aging. Clinical interactions.
AB - Effective treatment of the elderly patient with AML remains a challenging task.
Acute myelogenous leukemia is clearly a different disease in the elderly than in
the young, for many reasons, both clinical and biologic, which contribute to the
worse prognosis in the elderly. The elderly, as a group, have been
underrepresented in clinical trials. Several important prognostic variables have
been identified and described, however, that can help the physician select the
appropriate treatment for any individual patient. Age itself should not preclude
an attempt at therapy, especially for AML, which progresses very rapidly in the
absence of treatment. After careful analysis of prognostic factors, in any
individual patient, however, the outlook may be so poor that it may be desirable
to withhold treatment. With a better understanding of the pathophysiology of AML
in the elderly, more targeted and less toxic treatment regimens will become
available. At present, however, clinicians must use an improved understanding of
the disease to predict its behavior in an individual patient, so that the
currently available treatment modalities are used most prudently.
PMID- 10680082
TI - The family caregiver of the older cancer patient.
AB - Cancer care is becoming increasingly complex. The health care practices of the
present day make it imperative that the family provide assistance in the day-to
day management of a patient's symptoms and in the implementation of home care.
This increased responsibility for the family caregiver can come at great cost to
the overall functioning of the family, because of role changes, changes in the
family structure, and financial stressors, among others. Caregivers can
experience adverse effects on their mental and physical health that can remain
long after the caregiving role has ended. Although much of the research has
focused on the negative elements of caregiving, it must be remembered that there
are positive aspects to caregiving, which are now receiving attention in the
research literature. Although other factors affect caregiving, the model of
factors important in the caregiving experience presented in this article may
provide the impetus for studying the relationships among these different factors.
Results of these studies will allow the development of specific interventions to
help caregivers be more effective in their caregiving role and, at the same time,
address the overall impact of caregiving on the family.
PMID- 10680083
TI - Clinical research in the older cancer patient.
AB - The opportunities for conducting focused research in older patients with cancer
continue to increase and reflect the increasing awareness of the incidence of
cancer in older persons. As the population ages, cancer will become more and more
a problem of the elderly. Despite the magnitude of this problem, exploration of
the unique problems associated with cancer in the aging has only begun. Economic
issues, access to care, and the frequency of other serious illness in older
patients often make screening and treatment of malignancy in older patients a
great challenge. Oncologists and geriatricians must work together to guarantee
that appropriate funding is made available for cancer research in the elderly
population.
PMID- 10680084
TI - Association of Helicobacter pylori with gastroduodenal diseases.
AB - Helicobacter pylori was first cultured in vitro in 1982. This bacterium is a
spiral gram-negative rod which grows under microaerophilic conditions. The
ecological niche is the mucosa of the human stomach which had been thought to be
aseptic before the discovery of this bacterium. This organism causes a long
lasting infection throughout a person's life if there is no medical intervention.
Numerous persons are infected with the organism around the world, and the rate of
infection in Japan is nearly 50% of the population. However, the route of
infection remains unclear because the organism has not been isolated from any
environment other than several animals. H. pylori is now recognized as a
causative agent of gastritis and peptic ulcers. Though gastritis, and especially
chronic active gastritis, is observed at least histologically in all persons with
H. pylori, peptic ulcers develop in only some infected persons. Specific factors
in the host and/or the bacteria are needed for the development of peptic ulcer
disease. Furthermore, H. pylori is considered to be related to the development of
gastric mucosa-associated lymphoid tissue (MALT) lymphoma, especially those of
low grade. Also, H. pylori infection is a major determinant for initiating the
sequence of events leading to gastric cancer. In some patients with low-grade
gastric MALT lymphoma, the eradication of H. pylori led to a regression of
lesion. Gastric cancer has been induced in Mongolian gerbils with long-term H.
pylori infection. The combinations of drugs, which consist of an antisecretory
agent (acid-suppressing agent) and antimicrobial agents, are used for the
eradication of the organism. Eradication therapy is recommended at least for
patients with peptic ulcers.
PMID- 10680085
TI - Multiple sclerosis and measles virus.
AB - Epidemiological studies suggest that patients with multiple sclerosis (MS) are
exposed to some infectious agent(s) before puberty. The presence of virus-induced
demyelination in animal models indicates that demyelination can occur following
the trigger of a virus infection. Data regarding the immunological abnormalities
to measles virus (MV) and the presence of neurological complications induced by
MV infection suggest that MV may be a causative agent of the demyelination
observed in MS. Numerous virological studies (e.g., morphological observation,
virus isolation, and the search for the MV gene) have been performed, though
definite evidence identifying MV as the causative agent has not yet been
obtained.
PMID- 10680086
TI - Role of human parvovirus B19 in the pathogenesis of rheumatoid arthritis.
AB - Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown origin. It
has been speculated that infectious agents are responsible for triggering RA.
Persistent infection with human parvovirus B19 and its induction of
immunopathology are hypothesized to explain the initiation and perpetuation of
the disease process.
PMID- 10680087
TI - Pediatric admission for vaccine preventable diseases: a 5-year survey from 1994
to 1998 in Aichi Prefecture.
AB - Several infectious childhood diseases can be prevented by vaccination. A survey
of hospital admissions for such diseases was conducted in Aichi Prefecture over 5
years beginning in 1994. A questionnaire was sent annually to hospitals with 100
or more beds to obtain information on pediatric patients requiring
hospitalization for 10 vaccine preventable diseases. Information was obtained on
3,953 patients. Most admissions were for measles (49%), followed by mumps,
chickenpox, pertussis, rubella, and tuberculosis. Over half of the patients were
under 3 years old, with 20% aged under 12 months, 25% aged from 12 months to 2
years, and 10% aged from 2 to 3 years. The average hospital stay was longest for
tuberculosis and pertussis, and was around 1 week for the other diseases.
Familial transmission was the most common source of infection identified. The
only death was an unvaccinated patient with measles pneumonia. Sequelae were
reported at the time of discharge in 15 patients (0.4%), and were permanent in
some cases. Some 96% of the patients surveyed were unvaccinated against the
disease causing hospitalization. The fact that there were 14 patients with
sequelae and the one patient who died were unvaccinated, emphasizes the need to
promote vaccination.
PMID- 10680088
TI - Plasmodium infection-induced changes in salivary gland proteins of malaria vector
Anopheles stephensi (Diptera:Culicidae).
AB - Parasitism by Plasmodium yoelii yoelii induced 18 polypeptides in the salivary
glands of aging malaria vector Anopheles stephensi. A polypeptide of low
molecular size (30 kDa) could generally be induced at all infected stages. On day
5 post blood feeding (PBF), no new polypeptide could be found in the salivary
glands. Seven polypeptides of low molecular size and 3 of high molecular size
could be induced on day 11 PBF, which inducibility coincided with the invasion of
the salivary glands by the sporozoites. Quantitatively, soluble proteins
decreased in the salivary glands by about one-third in females that had consumed
infected or uninfected blood meal on day 9 (oocysts stage) as compared to
nonfeeding females. However, on day 15, in the salivary glands invaded by
sporozoites, the amount of proteins obtained from infected females was
approximately 26% lower than that obtained from uninfected females. A similar
reduction was also observed in aged (20 days PBF) salivary glands of infected
mosquitoes. These proteins could confer parasite tolerance to the females and
enhance parasite transmission potential.
PMID- 10680089
TI - Non-radioactive screening of DNA polymerases by using oligo r(A-U) as
primer/template for reverse transcriptase activity.
PMID- 10680090
TI - Salmonella Oranienburg involved in a variety of diseases.
PMID- 10680091
TI - Apparent cure of hepatitis C virus carrier state after hepatitis B virus
superinfection.
PMID- 10680092
TI - Selection of methicillin-resistant Staphylococcus aureus following increased use
of vancomycin despite restricted use of third generation cephem.
PMID- 10680093
TI - Review of the effect of spiritual and religious factors on mortality and
morbidity with a focus on cardiovascular and pulmonary disease.
PMID- 10680094
TI - The Toronto Cardiac Rehabilitation and Secondary Prevention Program: 1968 into
the new millennium.
AB - Given our approach to the cardiac rehabilitation process, which is reflected in
the program structure and services and our high patient volume, this program
model is effective for us. The model permits us to treat relatively large number
of patients with relatively small numbers of staff. On average, a patient attends
32 supervised exercise sessions at the Centre over the course of 12 months. This
is actually fewer supervised sessions than the popular model of 3 times per week
for 12 weeks. However, the 12-month program provides an additional 9 months to
work with patients on heart-healthy lifestyle modifications. At the same time, we
realize our model is not the model of choice for all people in all settings for a
variety of reasons. We trust that some elements of our program may be of interest
and beneficial to some readers. Undoubtedly, the program will continue to evolve
and develop into the future. Currently, we are conducting a cardiac
rehabilitation outcomes study in an effort to determine the appropriate duration
of cardiac rehabilitation to achieve optimal physiological, psychological, and
cost benefits for patients. This study involves more than 700 patients and the
results are intended to help us further refine the program structure and selected
program elements. As the new millennium approaches, healthcare system reforms and
continuing changes in the delivery of medical care to cardiac patients present
opportunities, challenges, and some uncertainties for cardiac rehabilitation. To
continue our services to patients and the medical community, cardiac
rehabilitation programs will need to identify and develop even more innovative
and effective concepts in response to ever-changing local, regional, and national
issues.
PMID- 10680095
TI - Rationale and design of the national emphysema treatment trial. A prospective
randomized trial of lung volume reduction surgery. The national emphysema
treatment trial research group
AB - The National Emphysema Treatment Trial is a multicenter, randomized clinical
trial of medical therapy vs medical therapy plus lung volume reduction surgery
(LVRS) for the treatment of patients with severe bilateral emphysema. LVRS will
be accomplished by bilateral stapled excision via median sternotomy or video
assisted thoracoscopic surgery. Every patient will complete 6 to 10 weeks of
pulmonary rehabilitation prior to randomization and will participate in a
maintenance program of pulmonary rehabilitation after randomization. The primary
outcome to be assessed by the trial is survival. Additional outcomes to be
assessed are maximum exercise capacity, pulmonary function, oxygen requirement,
distance walked in 6 min, quality of life, respiratory symptoms, and health-care
utilization and costs. In addition, selected clinics will evaluate lung mechanics
and respiratory muscle function, partial and maximal flow-volume curves, gas
exchange during maximal exercise, and right heart function. The trial is targeted
to enroll patients with severe emphysema who have no significant comorbid
conditions; each patient will be randomized to one of the two treatment groups.
The study duration is 4.5 years with a close-out period of 6 months.
PMID- 10680096
TI - A comparison of autogenic drainage and the active cycle of breathing techniques
in patients with chronic obstructive pulmonary diseases.
AB - PURPOSE: The effects of a long-term treatment of autogenic drainage (AD) and the
active cycle of breathing techniques (ACBT) were evaluated in patients with
chronic obstructive pulmonary disease (COPD). METHODS: Thirty clinically stable
male COPD patients were randomly assigned to AD or the ACBT treatment for a 20
day treatment period. Patients were assessed through pulmonary function tests,
arterial blood gases, a 6-minute walking test, and a modified Borg Scale before,
and immediately after the walking test. RESULTS: Autogenic drainage improved
forced vital capacity, forced expiratory volume in 1 second, peak expiratory flow
rate, forced expiratory volume from 25 to 75%, chronic hypercapnia, arterial
oxygenation, exercise performance, and dyspnea perception during exercise. The
ACBT increased forced vital capacity, peak expiratory flow rate, arterial
oxygenation and exercise performance. Peak expiratory flow rate increased in AD
more than in ACBT. In AD treatment, the increase in oxygen saturation was
significantly higher than in ACBT treatment. Chronic hypercapnia improved
significantly in AD treatment than in ACBT. No differences were found in other
lung function parameters. CONCLUSIONS: Autogenic drainage is as effective as the
ACBT in cleaning secretions and improving lung functions. These techniques can be
used in stable COPD patients according to the patients' and the physiotherapists'
preferences.
PMID- 10680097
TI - Muscle metabolism assessed by phosphorus-31 nuclear magnetic resonance
spectroscopy after myocardial infarction in rehabilitated patients: a 1-year
follow-up.
AB - BACKGROUND: The most common effect of postmyocardial infarction (post MI)
rehabilitation is an increase of peak maximal oxygen consumption correlated with
changes in calf muscle metabolism, but there are few data on follow-up after
rehabilitation on skeletal muscle and maximal oxygen consumption. The purpose of
this study was to investigate the respective modifications in skeletal muscle
metabolism and peak oxygen consumption (VO2) occurring during a supervised
rehabilitation program and 1 year after MI in patients free of heart failure.
METHODS: Fifteen outpatients were studied prospectively after the acute phase of
the MI, at the end of the rehabilitation program (2 months after the MI), and 1
year after. The rehabilitation comprised 20 sessions with three sessions per
week. The program consisted of exercise training with bicycle, arm ergometer, and
treadmill. The program also included respiratory exercises, psychological
support, and counseling for secondary prevention of cardiovascular diseases. At
each visit, a stress test on a bicycle ergometer was performed and the peak VO2
was measured. Phosphorus magnetic resonance spectroscopy of the gastrocnemius
muscle was performed at rest and during a plantar flexion-type exercise against
an adjustable load. Data were analyzed using analysis of variance and post-hoc
test when appropriate. RESULTS: The mechanical power output measured during the
bicycle exercise increased from 111 +/- 28 watts at the post MI test to 136 +/-
40 watts after rehabilitation (post rehab) and decreased to 125 +/- 36 watts at 1
year. The peak VO2 increased significantly (P < 0.05) from 22 +/- 7 ml/kg-1/min-1
(post MI) to 27 +/- 9 ml/kg-1/min-1 (post rehab), and decreased significantly to
24 +/- 8 ml/kg-1/min-1 (1 year). The mechanical power output measured in the
magnet during the stress test increased from 2.22 +/- 0.13 watts (post MI) to
2.85 +/- 1.24 (post rehab), and stabilized at 2.78 +/- 1.10 watts at 1 year. At
the highest workload attained in the three successive tests, the
phosphocreatine/(phosphocreatine + inorganic phosphate) ratio rose significantly
(P < 0.05) from 0.46 +/- 0.13 (post MI) to 0.51 +/- 0.13 (post rehab) and
remained at 0.51 +/- 0.13 at 1 year. CONCLUSION: The improvement of the peak VO2
after training post MI is not maintained 1 year later. This decline is not
accompanied by muscular metabolic abnormalities. This suggests that the muscle
metabolism after MI remains normal, and that the long-term decrease of the peak
VO2 reflects a global deconditioning that should be avoided by maintaining a long
term phase III rehabilitation program.
PMID- 10680098
TI - A home-based maintenance exercise program after center-based cardiac
rehabilitation: effects on blood lipids, body composition, and functional
capacity.
AB - BACKGROUND: Previous research indicates that patients exiting a 12-week cardiac
rehabilitation program (CRP) have difficulty maintaining an adequate exercise
program. Thus, the authors' purpose was to determine if a home-based exercise
program would enable patients to maintain/improve their blood lipids, body
composition, and functional capacity after exiting the CRP. METHODS: Thirty-one
patients exiting an initial 12-week CRP were assigned randomly to the home-based
(HB) intervention or the standard care (SC) condition. After one home visit, the
HB participants (n = 16) were contacted by telephone every other week by CRP
staff and completed and returned weekly exercise logs. The SC participants (n =
15) had no contact with the CRP other than to schedule follow-up tests. A third
group (n = 17), randomly selected from patients that elected to remain in the
center-based CRP (CB) for the same duration, also were examined. All groups
underwent exercise testing, fasting blood lipid analysis, and body composition
assessment before starting CRP (0M), after 3 months (3M) in a standard CRP, and
after 9 months (12M) in either HB, SC, or CB condition (12 months after starting
CRP). RESULTS: Analysis of variance indicated that there were significant
increases in metabolic equivalents and high-density lipoprotein, in all three
groups, over time. However, analysis of covariance revealed no significant
differences between the HB, SC, and CB groups at 12M for any variable.
CONCLUSIONS: These data indicate that the HB program was as effective as the CB
program at improving/maintaining functional capacity, blood lipids, and body
weight/composition. The similar success of the SC group is likely due to their
prior experience in CRP and knowledge of follow-up testing. Home-based
maintenance program could be offered as a low-cost alternative to CB programs.
PMID- 10680099
TI - Contemporary cardiac rehabilitation: patient characteristics and temporal trends
over the past decade.
AB - BACKGROUND: Recent and dramatic therapeutic advances, aggressive care of the
elderly, and a heightened awareness of secondary prevention have had a
significant, albeit incompletely described, impact on cardiac rehabilitation (CR)
programs. The authors did a retrospective analysis on 1,848 patients from their
phase II CR program that were treated over the past decade. The authors sought to
identify and analyze how advances in cardiovascular care might be related to
temporal changes in demographics, medical comorbidities, coronary artery disease
risk factors, and cardiovascular history among individuals with cardiac disease
who have completed the phase II CR program over a 10-year period. METHODS:
Cardiac rehabilitation records were reviewed from 1986 to 1996 at Akron City
Hospital. The data were compiled prospectively by nurses and exercise
physiologists and were subsequently analyzed. The charts reviewed were from 1,848
patients who completed outpatient phase II CR. RESULTS: The program began in 1986
with 53 patients completing CR and evolved to 309 in 1996. There has been an
increase in the number of elderly patients referred to and completing the
program. The number of participants older than 65 years of age increased from
28.3% in 1986 to 52.1% in 1996. Cardiac rehabilitation participants reflect the
known demographics of patients with clinical coronary artery disease. Men
outnumber women and, on average, the female participants are older than the male
participants. There has been a statistically significant increase in medical
comorbidities over the course of the study. Although the absolute number of
patients entering CR after coronary artery bypass graft survey has remained
fairly constant, there has been a dramatic increase in the absolute number of
patients entering CR after percutaneous tansluminal coronary angioplasty (with
the latter recently comprising a majority of CR participants). CONCLUSION: There
is a significant trend in the attendance and completion of CR programs by older
individuals, which suggests a greater awareness of patients and their physicians.
The growth of the program is fueled by high-risk patients with more comorbidities
who potentially are the group of patients able to obtain the greatest absolute
benefit from CR.
PMID- 10680100
TI - Mood-altering drugs and alternative integrative medicine: what we don't know,
what we need to know, and how we can find out.
PMID- 10680101
TI - The self-reporting of psychiatric medications in patients scheduled for elective
surgery.
AB - STUDY OBJECTIVE: To determine by survey the percentage of patients, over the age
of 21 years, reporting for elective surgery who also are taking psychotropic
medications. DESIGN: Institution-approved, anonymous survey. SETTING: Teaching
hospital. PATIENTS: 169 patients who were scheduled for elective surgery.
INTERVENTIONS: After completion of the preoperative evaluation by members of the
anesthesia care team, all patients were given an institution-approved survey of
medications they were taking in addition to their nonpsychiatric medications. The
survey listed 33 drugs known to affect central nervous system neurotransmitters,
and included the most commonly prescribed antidepressants, antipsychotics,
benzodiazapines, and lithium. Over-the-counter drugs known to affect mood, such
as melatonin, also were included in the survey. Patients were not asked the
indications for the medications, and no psychiatric questions were asked of the
patients. MEASUREMENTS AND MAIN RESULTS: 300 surveys were distributed, and 169
patients completed the survey for a response rate of 53%. Forty-three percent of
all patients who completed the survey admitted to taking one or more of the
psychotropic medications. Of these patients, 35% were taking antidepressants, 34%
were taking benzodiazapines, 19% were taking combination therapies, and 11% took
antipsychotics, lithium, or over-the-counter drugs such as melatonin. CONCLUSION:
The number of patients taking psychotropic medications and who present for
elective surgery is high. The anesthetic implications of this drug usage are
essentially unknown. Additional study of these medications and their impact on
anesthetic care is warranted.
PMID- 10680102
TI - Course of molecular hemostatic markers during and after different surgical
procedures.
AB - STUDY OBJECTIVE: To establish the most vulnerable time of thrombi formation with
regard to the plasmatic (noncellular) part of the coagulatory and fibrinolytic
systems. DESIGN: Nonrandomized observational study. SETTING: A surgical and an
orthopedic unit and the central laboratory of a university hospital. PATIENTS: 61
consenting ASA physical status I and II inpatients undergoing four different
types of surgery: total hip replacement (THR): 16 patients; hemicolectomy: 15
patients; endoscopic cholecystectomy: 15 patients; subtotal thyroid resection: 15
patients. INTERVENTIONS: The time course of 11 procoagulatory and fibrinolytic
parameters was examined during the different types of surgery. Blood samples were
drawn on the day before surgery, directly before the induction of general
anesthesia, 1 to 2 hours postoperatively, and on the mornings of postoperative
days 1, 2, 3, 4, and 5. MEASUREMENTS AND MAIN RESULTS: The coagulation samples
were centrifuged within 1 hour of collection at 2,300 g for 15 minutes at 4
degrees C. Hemoglobin, hematocrit, platelets, fibrinogen, prothrombin time,
activated partial thromboplastin time, thrombin time, antithrombin III, and
protein C were determined immediately on laboratory arrival of the samples. The
samples were aliquoted at -70 degrees C. They were thawed within 2 weeks and
prepared for the following assays: thrombin-antithrombin III complexes (TAT
complexes), D-dimers, and plasminogen activator inhibitor type 1. Maximum
activation of coagulation is not reached until 2 hours postoperatively and slowly
decreases until normal values are reached around the fifth postoperative day.
Parameters displaying the greatest changes are TAT-complexes and D-dimers. The
type of surgery with the most pronounced changes was total hip replacement,
followed by hemicolectomy, cholecystectomy, and subtotal thyroid resection.
CONCLUSION: The total hip replacement and hemicolectomy groups show similar and
strong activation of the procoagulatory and fibrinolytic systems. Much less
pronounced are the changes during endoscopic cholecystectomy and subtotal thyroid
resection. Maximum activation occurs 1 to 2 hours postoperatively.
PMID- 10680103
TI - The pharmacokinetics of morphine and lidocaine in nine severe trauma patients.
AB - STUDY OBJECTIVE: To study the pharmacokinetic parameters of morphine and
lidocaine after a single intravenous (i.v.) bolus in severe trauma patients.
DESIGN: Clinical case study. SETTING: Department of Anesthesiology and Intensive
Care of a university hospital. PATIENTS: Nine patients, ages 24 to 91 years (mean
54.4 yrs), admitted to the hospital with severe trauma (Injury Severity Score >
20) were included in the study. INTERVENTIONS: After initial evaluation and
stabilization, a single i.v. dose of morphine 0.025 mg/kg and lidocaine 1.5 mg/kg
was given separately, and blood samples were drawn for each drug serum
concentration. MEASUREMENTS AND MAIN RESULTS: Morphine pharmacokinetics was
studied in eight patients, lidocaine pharmacokinetics in seven patients, and both
drugs were studied in six patients. Morphine clearance 2.5 to 10 ml/kg/min (6 +/-
2.6, mean +/- SD) and volume of distribution 0.28 to 3.30 L/kg (1.4 +/- 1.0) were
found to be lower than values described previously for healthy volunteers (33.5
+/- 9 ml/kg/min and 5.16 +/- 1.40 L/kg, respectively), and are similar to those
described in trauma patients (5 +/- 2.9 ml/kg/min and 0.9 +/- 0.2 L/kg,
respectively). In contrast, lidocaine clearance 4.5 to 9.4 ml/kg/min (6.7 +/-
1.7) and volume of distribution 0.39 to 1.20 L/kg (0.72 +/- 0.28) were similar to
the value described in healthy volunteers (10 ml/kg/min and 1.32 L/kg,
respectively). CONCLUSION: Changes in pharmacokinetics of drugs eliminated by the
liver may occur in patients with severe trauma. The preserved lidocaine clearance
indicates an almost normal hepatic blood flow and suggests that other mechanisms
may be involved in the lower morphine clearance. The findings may have
applications for the treatment of severe trauma patients and suggest that drug
monitoring might be needed in some instances so as to avoid toxicity.
PMID- 10680104
TI - Influence of thiopental and propofol on postoperative cognitive recovery in the
elderly patient undergoing general anesthesia.
AB - STUDY OBJECTIVE: To assess mental and psychomotor recovery following induction of
anesthesia with thiopental or propofol in elderly patients undergoing general
anesthesia. DESIGN: Randomized, prospective, double-blind study. SETTING: Large
referral hospital. PATIENTS: 40 elderly patients ASA physical status I-III (> 65
years) undergoing abdominopelvic surgery with an estimated surgical time of at
least 90 minutes. INTERVENTIONS: All patients received combined epidural-general
anesthesia. After establishing a T6 sensory blockade, patients were randomized to
receive either thiopental or propofol for induction of general anesthesia. The
induction drug was slowly titrated until loss of eyelash reflex was noted.
Thereafter, all patients received desflurane (2% to 3% end-tidal) and 70% nitrous
oxide (N2O) in oxygen for maintenance of general anesthesia. To facilitate
tracheal intubation, intravenous alfentanil 10 micrograms/kg and atracurium 0.4
mg/kg were administered. Perioperative analgesia was maintained with epidural
bupivacaine. MEASUREMENTS AND MAIN RESULTS: A digit substitution test (DSST) and
shape-sorter test, as well as patient-generated 100-mm visual analog score (VAS;
0 = minimal and 100 = maximal) for anxiety, sleepiness, and coordination, were
performed during the preanesthetic interview, on postanesthesia care unit
admission, and at 15, 45, 90, and 120 minutes thereafter. To induce loss of
consciousness, either thiopental 2.5 +/- 1.0 mg/kg or propofol 1.6 +/- 0.6 mg/kg
was administered. The mean anesthetic time was 109 +/- 30 minutes and 114 +/- 38
minutes for the thiopental and propofol groups, respectively. Emergence,
extubation, and orientation times, as well as time to follow commands, were
unaffected by patient randomization. Similarly, the DSST and shape-sorter tests,
in addition to the patient-generated VAS for pain, anxiety, and coordination,
were similar among groups. However, irrespective of treatment modality, return to
baseline digit substitution and shape-sorter scores were significantly delayed (p
< 0.01). CONCLUSION: When compared to thiopental, propofol does not facilitate
improved cognitive recovery in geriatric patients undergoing prolonged surgery.
PMID- 10680105
TI - Effects of pretreatment with cisatracurium, rocuronium, and d-tubocurarine on
succinylcholine-induced fasciculations and myalgia: a comparison with placebo.
AB - STUDY OBJECTIVE: To evaluate the efficacy of cisatracurium, rocuronium, and d
tubocurarine in preventing succinylcholine-induced fasciculations and
postoperative myalgia in patients undergoing ambulatory surgery. DESIGN:
Randomized, prospective, placebo-controlled trial SETTING: Teaching hospital.
SUBJECTS: 80 ASA physical status I and II patients scheduled for elective
ambulatory surgery with general anesthesia. INTERVENTION: A standardized balanced
anesthetic technique was used for all patients. MEASUREMENTS AND MAIN RESULTS:
Patients were randomized to receive cisatracurium 0.01 mg/kg, rocuronium 0.06
mg/kg, d-tubocurarine 0.05 mg/kg, or saline, 3 minutes prior to intravenous
(i.v.) succinylcholine 1.5 mg/kg. The intensity of fasciculations and intubating
conditions were assessed using a four-point rating scale. In addition, the
severity of myalgia was assessed using a four-point rating scale in the
postanesthesia care unit and at 24 hours postoperatively. No patient complained
of any side effects after the administration of the study drug. Fasciculations
were observed less frequently (p < 0.05) in the d-tubocurarine and rocuronium
groups compared with the placebo and cisatracurium groups. However, there was no
difference between the d-tubocurarine group and the rocuronium group (21% vs.
10%, respectively). Although fasciculations occurred less frequently in the
cisatracurium group than in the placebo group (59% vs. 85%, respectively), this
difference did not reach statistical significance. There was no difference among
the four groups in the intubating conditions or the incidence of postoperative
myalgia. CONCLUSION: Pretreatment with rocuronium and d-tubocurarine was superior
to cisatracurium in preventing succinylcholine-induced fasciculations. However,
pretreatment did not have any effect on the incidence of myalgia after ambulatory
surgery.
PMID- 10680106
TI - Effects of intraoperative glucose administration on circulating metabolites and
nitrogen balance during prolonged surgery.
AB - STUDY OBJECTIVES: To compare the effects of intraoperative administration of 2.5%
glucose or Ringer's solution on metabolism during prolonged surgery. DESIGN:
Prospective, randomized study. SETTING: Teaching hospital. PATIENTS: 20 ASA
physical status I and II adults patients scheduled for thoracic or abdominal
surgery lasting at least 3 hours. INTERVENTIONS: Patients received Ringer's
solution (Group R) or 2.5% glucose solution (Group G) 10 ml.kg-1.h-1 during
surgery and 2 ml.kg-1.h-1 during the first two postoperative hours (Ringer's or
glucose), then 40 ml.kg-1.day-1 of 5% intravenous (i.v.) glucose postoperatively.
MEASUREMENTS AND MAIN RESULTS: Plasma glucose, free fatty acids, ketone bodies,
lactate, insulin, glucagon, cortisol, and growth hormone concentrations were
determined after an overnight fast (T0), on induction of anesthesia (T1), at the
end of surgery (T2), 2 hours thereafter (T3), and on the following morning (T4).
Capillary blood glucose was determined every 30 minutes from T1 to T2. Urinary
nitrogen and 3-methylhistidine were measured every day for 5 days. There were no
differences between groups in demographic data, anesthesia, or surgical
procedures. All data were comparable at baseline and on the following morning. In
Group R, no patient experienced hypoglycemia, but plasma fatty acids and ketone
bodies increased during surgery. In Group G, glycemia rose to very high levels,
with a significant increase in insulin during surgery. Other hormones were the
same within the two groups. Urinary nitrogen and 3-methylhistidine were similar
in both groups. CONCLUSION: The absence of glucose infusion in prolonged surgery
did not cause hypoglycemia, and no increase in protein catabolism was observed.
PMID- 10680107
TI - Duration and recovery profile of cisatracurium after succinylcholine during
propofol or isoflurane anesthesia.
AB - STUDY OBJECTIVE: To determine the duration and recovery profile of maintenance
doses of cisatracurium besylate following succinylcholine, and during propofol or
isoflurane anesthesia. DESIGN: Randomized, open-label study. SETTING: Operating
suite of a university-affiliated medical center. PATIENTS: Forty ASA physical
status I and II adult patients having elective surgery with general anesthesia
lasting longer than 90 minutes. INTERVENTIONS: Following a standardized induction
sequence, a baseline electromyogram (EMG) was obtained. An intubating dose of
intravenous (i.v.) succinylcholine 1.0 mg/kg was administered. Ventilation was
maintained with a face mask until the first twitch (T1) of the evoked train-of
four (TOF) reached 10% of control when tracheal intubation was performed.
Spontaneous recovery from neuromuscular blockade was allowed to occur until the
first twitch returned to 25% of control. Patients then were randomized to receive
cisatracurium as follows. Group 1: 0.025 mg/kg [0.5 x 95% effective dose (ED95)];
Group 2: 0.05 mg/kg (ED95); Group 3: 0.05 mg/kg (ED95); and Group 4: 0.1 mg/kg (2
x ED95). Anesthesia for Groups 1 and 2 were maintained with isoflurane 1% to 2%,
66% nitrous oxide (N2O) in oxygen (O2), and in Groups 3 and 4, anesthesia was
maintained with propofol 80 to 160 micrograms/kg/min, 66% N2O in O2. The TOF
evoked EMG was recorded at 10-second intervals. The time for the evoked EMG to
spontaneously return to 25%, 50%, and 75% of the original baseline was recorded.
MEASUREMENTS AND MAIN RESULTS: There were 10 patients in each of the four groups.
The duration of action of cisatracurium 0.05 mg/kg (ED95) after an intubating
dose of succinylcholine is 24.5 +/- 10 minutes and 21.3 +/- 9 minutes during
anesthesia maintained with isoflurance and propofol, respectively. Doubling the
dose of cisatracurium resulted in approximately twice the duration of action
(40.2 +/- 7 min) during propofol anesthesia. Following a dose of cisatracurium
0.025 mg/kg (0.5 x ED95), the T1 of the EMG-evoked response did not decrease
below 25% in 7 of 10 patients. CONCLUSION: Following succinylcholine, the
duration of action of a single dose of cisatracurium 0.05 mg/kg is 20 to 25
minutes during anesthesia maintained with propofol or isoflurane. The duration
and recovery profile of cisatracurium is dose dependent during propofol and
isoflurane anesthetics. Cisatracurium 0.025 mg/kg is an inadequate maintenance
dose following recovery from succinylcholine and it fails to provide adequate
surgical relaxation.
PMID- 10680108
TI - Comparison of incidence of gastroesophageal reflux and regurgitation associated
with timing of removal of the laryngeal mask airway: on appearance of signs of
rejection versus after recovery of consciousness.
AB - STUDY OBJECTIVES: To compare the incidence of gastroesophageal reflux and
regurgitation associated with laryngeal mask airway (LMA) removal when signs of
rejecting the LMA, such as swallowing, struggling, and restlessness, were
observed and when the patient could open his or her mouth on command. DESIGN:
Randomized clinical trial. SETTING: Operating room and recovery room of a
tertiary care referral hospital. PATIENTS: 63 ASA physical status I and II adult
patients scheduled for elective orthopedic surgery. INTERVENTIONS: Using a
standardized general anesthetic technique, patients were allocated randomly to
Group A (n = 34; LMA removed when signs of rejection, such as swallowing,
struggling, and restlessness, were observed) or Group B (n = 29; LMA removed when
the patient could open his or her mouth on command). MEASUREMENTS AND MAIN
RESULTS: To detect gastroesophageal reflux throughout anesthesia, a pH monitoring
probe was positioned in the lower esophagus on the day before surgery. To assess
regurgitation during emergence, a gelatin capsule of methylene blue (50 mg) was
swallowed prior to induction. At the end of anesthesia, episodes of reflux and
regurgitation of gastric contents were analyzed/determined by pH below 4 and
bluish staining of the pharynx and/or LMA, respectively. Physical events such as
bucking, straining, and coughing during the arousal phase were recorded in both
groups by an independent observer. The incidence of reflux (pH < 4) from the time
of the appearance of rejection signs to LMA removal and the total incidence of
reflux in Group B were significantly higher than in Group A (p < 0.05). Staining
of the LMA and the pharynx by methylene blue was not observed in patients from
either experimental group. The number of physical events in Group B during the
arousal phase was significantly increased compared to Group A (p < 0.05).
Considering all patients in Group A and Group B, physical events were associated
with the occurrence of reflux (p < 0.05). Desaturation (SpO2 < 95%) and clinical
evidence of aspiration of gastric contents did not occur in either group.
CONCLUSION: Maintenance of the LMA until the patient can open his or her mouth on
command increases the incidence of gastroesophageal reflux.
PMID- 10680109
TI - Low doses of epidural ketamine or neostigmine, but not midazolam, improve
morphine analgesia in epidural terminal cancer pain therapy.
AB - STUDY OBJECTIVE: To examine analgesia and adverse effects of combination epidural
pain therapy consisting of administration of morphine with either low dose of
ketamine, neostigmine, or midazolam in terminal cancer pain patients. DESIGN:
Randomized double-blind study. SETTING: Teaching hospital. PATIENTS: 48 terminal
cancer patients suffering from chronic pain. INTERVENTIONS: Patients were
randomized to one of four groups (n = 12). The concept of visual analog scale
(VAS), which consisted of a 10-cm line with 0 equaling "no pain at all" and 10
equaling "the worst possible pain" was introduced. All patients were taking oral
amitriptyline 50 mg at bedtime. Pain was initially treated with epidural morphine
2 mg twice daily (12-hr intervals) to maintain the VAS below 4/10. Afterwards,
VAS scores > or = 4/10 at any time were treated by adding the epidural study drug
(2 ml), which was administered each morning, just after the 2-mg epidural
morphine administration. The control group (CG) received 2 mg of epidural
morphine (2 ml). The ketamine group (KG) received 0.2 mg/kg epidural ketamine (2
ml). The neostigmine group (NG) received 100 micrograms epidural neostigmine (2
ml). The midazolam group (MG) received 500 micrograms epidural midazolam (2 ml).
Patients received the study drugs on a daily basis. MEASUREMENTS AND MAIN
RESULTS: Duration of effective analgesia was measured as time from the study drug
administration to the first patient's VAS score > or = 4/10 recorded in days. The
groups were demographically the same. The VAS pain scores prior to the treatment
were also similar among groups. Only the patients in the KG demonstrated lower
VAS scores compared to the MG (p = 0.018). Time since the epidural study drug
administration until patient complaint of pain VAS > or = 4/10 was higher for
both the KG and NG compared to the CG (KG > CG, p = 0.049; NG > CG; p = 0.0163).
Only the KG used less epidural morphine compared to the CG during the period of
study (25 days) (p = 0.003). CONCLUSION: The association of either low-dose
epidural ketamine or neostigmine (but not midazolam) to epidural morphine
increased the duration of analgesia in the population studied (gt;20 days)
compared to the CG and MG (8 to 10 days) when administered in the early stages of
terminal cancer pain therapy, without increasing the incidence of adverse
effects.
PMID- 10680110
TI - Interaction of an implanted pacemaker with a transesophageal atrial pacemaker:
report of a case.
AB - We report an interaction of a transesophageal atrial pacemaker (TAP) with a
permanently implanted pacemaker in a cardiac patient who had undergone ablative
therapy for atrial tachyarrhythmia 5 years earlier. The patient's permanent A-V
pacemaker was completely inhibited by the TAP, and there was loss of ventricular
contractions and blood pressure. The patient required epicardial A-V pacing to
overcome the programmed heart rate of 76 bpm. We describe alternative methods to
epicardial pacing. We also recommend close inspection of the chest radiograph,
which often can reveal the serial numbers of the implanted pacemaker, as a means
of identifying the device's functions and programming.
PMID- 10680111
TI - Induction of general anesthesia using propofol for cesarean section of a woman
with cerebral palsy.
AB - A 45-year-old pregnant woman with cerebral palsy was scheduled for cesarean
section at 37 weeks' gestation due to the risk of athetotic reaction. Spinal
anesthesia appeared difficult to perform due to maintenance position, and because
maternal respiratory depression due to athetotic reaction to mechanical
stimulation might cause fetal hypoxia. We therefore selected general anesthesia.
Propofol and succinylcholine were intravenously (i.v.) administered for
induction, and additional propofol was administered i.v. for hemodynamics
stabilization. Neonatal Apgar scores were 8 at one minute and 10 at five minutes.
No maternal respiratory depression was observed postoperatively, and a healthy
baby was successfully delivered.
PMID- 10680112
TI - Noncardiogenic pulmonary edema associated with protamine administration during
coronary artery bypass graft surgery.
AB - Protamine sulfate is the only agent approved to reverse heparin-induced
anticoagulation. As with any other drug, protamine has the potential to cause
adverse effects that range from mild hypotension to potentially fatal events,
such as noncardiogenic pulmonary edema (NCPE) and catastrophic pulmonary
vasoconstriction. We report a case of NCPE after the administration of protamine
to a patient undergoing coronary artery bypass graft surgery and discuss the
diagnosis and management of this severe adverse event.
PMID- 10680113
TI - VisualiSAR: a web-based application for clustering, structure browsing, and
structure-activity relationship study.
AB - VisualiSAR is a program designed to display chemical structures, find
similarities and differences between them, and highlight relationships that might
exist. The program integrates cluster analysis for the grouping of structurally
related compounds, modal analysis of molecular fingerprints for the sorting and
highlighting of chemical features, and a Web-based interface for flexibility and
ease of use. VisualiSAR has proved useful for a number of applications including
the discernment of structure-activity relationships (SAR) of high-volume
screening data, and general structure browsing. This article discusses the design
of the tool and illustrates two applications.
PMID- 10680114
TI - Computational prediction of the three-dimensional structures for the
Caenorhabditis elegans tubulin family.
AB - In this article we characterize, from a structural point of view, all 16 members
of the tubulin gene family of Caenorhabditis elegans (9 alpha-tubulins, 6 beta
tubulins, and 1 gamma-tubulin). We obtained their tertiary structures by
computationally modifying the X-ray crystal structure of the pig brain alpha/beta
tubulin dimer published by Nogales et al. [Nature (London) 1998;391:199-203]. Our
computational protocol involves changing the amino acids (with MIDAS; Jarvis et
al., UCSF MIDAS. University of California, San Francisco, 1986) in the 3D
structure of pig brain alpha/beta-tubulin dimer followed by geometry optimization
with the AMBER force field (Perlman et al., AMBER 4. University of California,
San Francisco, 1990). We subsequently analyze and compare the resulting
structures in terms of the differences in their secondary and tertiary
structures. In addition, we compare the pattern of hydrogen bonds and hydrophobic
contacts in the guanosine triphosphate (GTP)-binding site for all members of the
tubulin family. Our computational results show that, except for gamma-tubulin,
all members of the C. elegans tubulin family have similar secondary and 3D
structures and that the change in the pattern of hydrogen bonds in the GTP
binding site may be used to assess the relative stability of different alpha/beta
tubulin dimers formed by monomers of the tubulin family.
PMID- 10680115
TI - The mean hydration of carbohydrates as studied by normalized two-dimensional
radial pair distributions.
AB - The hydration of carbohydrates plays a key role in many biological processes.
Molecular dynamics simulations provide an effective tool for investigating the
hydration of complex solutes such as carbohydrates. In this article we devise an
algorithm for the calculation of two-dimensional radial pair distributions
describing the probability of finding a water molecule in a site defined by two
reference atoms. The normalized 2D radial pair distribution is proposed as an
effective tool for investigating and comparing localized or ordered water sites
around flexible molecules such as carbohydrates when analyzing molecular dynamics
simulations and the utility of 2D radial pair distributions is demonstrated using
sucrose as an example. In this relatively simple structure, 2D radial pair
distributions were able to characterize and quantify the importance of two unique
interresidue hydration sites in which a water molecule is forming a bridge
between the glycopyranosyl and fructofuranosyl residues. The approach is proposed
to be a valuable tool for comparing and understanding the hydration of flexible
biomolecules such as carbohydrates.
PMID- 10680116
TI - The whey acidic protein family: a new signature motif and three-dimensional
structure by comparative modeling.
AB - Whey acidic proteins (WAP) from the mouse, rat, rabbit, camel, and pig comprise
two "four-disulfide core" domains. From a detailed analysis of all sequences
containing this domain, we propose a new PROSITE motif ([KRHGVLN]-X-?PF?-X-[CF]
[PQSVLI]-X(9,19)-C-?P?-X-[DN]-X-?N? -[CE]-X(5)-C-C) to accurately identify new
four-disulfide core proteins. A consensus model for the WAP proteins is proposed,
based on the human mucous proteinase inhibitor crystal structure. This article
presents a detailed atomic model for the two-domain porcine WAP sequence by
comparative modeling. Surface electrostatic potential calculations indicate that
the second domain of the pig WAP model is similar to the functional human mucous
proteinase inhibitor domains, whereas the first domain may be nonfunctional.
PMID- 10680117
TI - A homology modeling method of an icosahedral viral capsid: inclusion of
surrounding protein structures.
AB - A methodological development is presented for homology modeling of an
icosahedrally symmetric assembly of proteins. In the method, a main-chain
structure of an asymmetric unit of a protein assembly is constructed and
structure refinement is performed, taking the surrounding symmetry-related
proteins into consideration with rotational symmetry boundary conditions. To test
the procedure, three models of a poliovirus capsid were constructed with
different modeling conditions based on the X-ray structure of a rhinovirus
capsid. Model S and model N were constructed with and without considering
surrounding proteins, respectively. Model N2 was obtained by refinement in
rotational symmetry boundary conditions of the structure of model N. The three
models were compared with the X-ray structure of a poliovirus capsid. Root mean
square deviations and C alpha distances indicate that model S is the most
accurate. Examination of the intermolecular short contacts indicates that model S
and model N2 are superior to model N, because they do not make severe
intermolecular short contacts. Symmetric intermolecular interactions are
important for both the structural fragment search and energy minimization to
predict better loop structures. The programs developed in this study are thus
valuable in homology modeling of an icosahedral viral capsid.
PMID- 10680118
TI - The art of molecular graphics. When left isn't right.
PMID- 10680119
TI - High performance computational chemistry using parallel PC clusters: an
introduction to Beowulf clusters for chemists.
PMID- 10680120
TI - Using MOE to visualize molecular orbitals.
PMID- 10680121
TI - Virtual network computing: cross-platform remote display and collaboration
software.
AB - VNC (Virtual Network Computing) is a computer program written to address the
problem of cross-platform remote desktop/application display. VNC uses a
client/server model in which an image of the desktop of the server is transmitted
to the client and displayed. The client collects mouse and keyboard input from
the user and transmits them back to the server. The VNC client and server can run
on Windows 95/98/NT, MacOS, and Unix (including Linux) operating systems. VNC is
multi-user on Unix machines (any number of servers can be run are unrelated to
the primary display of the computer), while it is effectively single-user on
Macintosh and Windows machines (only one server can be run, displaying the
contents of the primary display of the server). The VNC servers can be configured
to allow more than one client to connect at one time, effectively allowing
collaboration through the shared desktop. I describe the function of VNC, provide
details of installation, describe how it achieves its goal, and evaluate the use
of VNC for molecular modelling. VNC is an extremely useful tool for
collaboration, instruction, software development, and debugging of graphical
programs with remote users.
PMID- 10680122
TI - [Effect of obesity on the morphology of the left ventricle].
AB - BACKGROUND: To analyze the relationship between obesity in its different degrees
and the left ventricle morphology. PATIENTS AND METHODS: M-mode echocardiography
was used to estimate the mass, wall thickness and internal dimension of left
ventricle in 48 obese women with different degrees of obesity, defined according
to the body mass index. 25 women with normal weight were used as controls.
RESULTS: The body mass index was correlated with left ventricular mass, as well
as with both the wall thickness of the left ventricle and its diastolic internal
dimension. The abnormalities in the heart morphology increased according to the
obesity degree, ranging from a 59% in the lesser obesity group up to a 100% in
the more obese women. The incidence of the left ventricular hypertrophy
determined by echocardiography also increased along with the body mass index,
ranging from a 29% in the lesser degree of obesity women up to an 82% in the
patients with a body mass index > 35 kg/m2. CONCLUSIONS: Obesity, even in its
lowest degrees, shows frequent alterations in the heart morphology. This is
related with a left ventricular mass increase and a higher incidence of the left
ventricular hypertrophy. The left ventricular mass increase is due to an increase
in the left ventricular walls thickness and also to a dilatation of its cavity.
PMID- 10680123
TI - [Secular increase of adipose tissue in adolescents from Zaragoza from 1980 to
1995].
AB - BACKGROUND: To quantify the differences between anthropometric measurements
obtained nowadays in male and female adolescents and those obtained 15 years ago
in a sample of similar characteristics. SUBJECTS AND METHODS: We have studied 658
healthy individuals, 329 males and 329 females from 10.0 to 15.0 years of age,
from different socioeconomic levels. Weight, height, arm circumference and left
skinfold thickness (biceps, triceps, subscapular and suprailiac) have been
measured. We have calculated the body mass index (BMI), density, total body fat,
percentage of body fat and the body adipose muscular index (BAMI), which is the
ratio between body fat (kg) and non fat mass (kg). The values obtained have been
compared with those obtained fifteen years ago, in another sample of 1,465
children with similar characteristics. The research team and the material used
were the same in both studies. Mean differences were compared using the unpaired
t-test. RESULTS: Weight has increased significantly (p < 0.05), except for males
at 12 years and females at 13 and at 14 years. Height has increased significantly
at all ages and in males and females (p < 0.05). BMI has only increased
significantly at 10 and at 11 years in males, and at 10 years in females.
Skinfold thicknesses have also increased significantly, except for biceps in
males between ages of 12 and 14 years and biceps and subscapular in females at 14
years. Body fat mass and percentage of body fat have also increased significantly
and, in consequence, the density has decreased and BAMI has increased both
significantly (p < 0.05). CONCLUSIONS: Secular increase in weight and height
during fifteen years has occurred. In general, BMI has not increased but skinfold
thicknesses and body fat have increased significantly, this fact demonstrates
that there has been increase in the body fat compartment.
PMID- 10680124
TI - [Lipid profile of the Spanish population: the DRECE (diet and risk of
cardiovascular disease in Spain) study. DRECE study group].
AB - BACKGROUND: In Spain the mortality rate due to cardiovascular disease (CVD) is
relatively low compared to that of other developed countries. Until now few
epidemiological studies have been performed among the global Spanish population
to evaluate a relation between CVD risk factors and the lipid profile that could
justify our privileged situation. For, this reason, the DRECE study was designed
to know the situation at present in Spain respect to the risk of suffering from
CVD in particular, the lipid profile. POPULATION AND METHODS: This study included
4,787 subjects (2,324 males and 2,463 females) with an age ranging from 5-60
years, representative of the total Spanish population with these characteristics
during the period from 1992 to 1994. Medical history was made for all
participants, who also underwent a physical examination. The following parameters
were determined: total cholesterol (TC), triglycerides, high-density lipoproteins
cholesterol HDLc, cholesterol transported by low-density lipoproteins, LDLc
(estimated by the Friedewald's formula), apolipoprotein AI and apoliprotein B
(immunoturbidimetry). RESULTS: The results obtained and expressed in mean (SD)
show that, although the population has total cholesterol concentrations (190.1
[42.4] and 192.8 [44.8] mg/dl for females and males, respectively) and LDLc
(113.9 [37.9] and 117.5 [38.1] mg/dl for females and males, respectively) with
values as high as those found in developed countries, the HDLc concentrations
(58.6 [13.2] and 51.5 [13.4] mg/dl for women and men, respectively) are also
increased and this could be the reason why the mortality rate in Spain caused by
CVD is lower than in other countries. CONCLUSIONS: The finding of high HDLc
levels and their antiatherogenic role could justify that, at best in part, the
rate mortality in Spain is lower than in other developed countries.
PMID- 10680125
TI - [Changes in plasma concentrations of lipids and lipoproteins in students from
1992 to 1996: Cuenca study].
AB - BACKGROUND: The aims of this study were to analyze the evolution of plasma lipid
and lipoprotein levels in school children of Cuenca city, Spain, between 1992 and
1996; and to study pubertal changes in 1992 cohort. SUBJECTS AND METHODS: A
longitudinal observational study was made in 642 schoolchildren 9-16 years old
recruited in three public schools of Cuenca city. In 1992, 307 schoolchildren 9
16 years old were examined. On a second examination made in 1996 were examined
children of the cohort of 1992 as well as other children who were 9-11 years old
in 1996; and belonged to the same schools were recruited. Socio-demographics
variables, weight, height, body mass index, systolic blood pressure, diastolic
blood pressure and fasting plasma total cholesterol, LDL-C, HDL-C and
triglyceride concentrations were determined (and in addition, the apoproteins A-I
and B100 and lipoprotein (a) were determined in the second examination). RESULTS:
Between the years 1992 and 1996 there has been a falling in total cholesterol
concentrations of schoolchildren of the cohort of 1992 due to a decreasing in LDL
C and HDL-C levels, the levels total cholesterol ranged from 183.0 mg/dl to 163.3
mg/dl. Comparing the lipid concentrations of the schoolchildren who were 9 to 11
years old in the cohort of 1992 with the lipid concentrations who were 9 to 11
years old in the cohort of 1992 with the lipid concentrations of 1996 it has been
found evidence of an important decreasing of total cholesterol and LDL-C, and a
moderate increasing in the HDL-C, whereas triglycerides are stable. CONCLUSIONS:
Due to the decreasing of total cholesterol and LDL-C levels and the increasing of
HDL-C, the lipid profile in schoolchildren of Cuenca city has improved during the
1992-1996 years. Total cholesterol and HDL-C concentrations of 1992 cohort have
been a falling during the puberty.
PMID- 10680126
TI - [HIV infection: to eradicate it or control it?].
PMID- 10680127
TI - [Declaration of the financial interests of clinical trial researchers].
PMID- 10680128
TI - [Advances in the treatment of the critically burnt patient].
PMID- 10680129
TI - [Assessment of 2 serologic tests (indirect immunofluorescence and ELISA) for the
detection of antimalaria antibodies].
PMID- 10680130
TI - [Antivenom serum against Vipera latasti?].
PMID- 10680132
TI - [PubMed: good, beautiful and affordable?].
PMID- 10680131
TI - [Lung leiomyosarcoma 21 years after hysterectomy for uterine leiomyosarcoma: late
metastasis?].
PMID- 10680133
TI - [Influenza: disease risks versus vaccine risks].
PMID- 10680134
TI - [Affection-based medicine, family medicine, and university].
PMID- 10680135
TI - [Cytokines and immunomodulation in blood transfusion: a permanent challenge].
PMID- 10680136
TI - [Recurrent myocardial ischemia after spontaneous abortion secondary to oral
ergotamine alkaloids].
PMID- 10680137
TI - [Angioedema-urticaria caused by angiotensin-converting enzyme inhibitors and
angiotensin II receptor antagonists].
PMID- 10680138
TI - [Scleroderma and pregnancy: obstetrical complications and the impact of pregnancy
on the course of the disease].
AB - BACKGROUND: To describe the outcome of the pregnancy in patients with
scleroderma. PATIENTS AND METHODS: Patients with scleroderma and control group
were included in this retrospective study. Two groups were different in pregnant
patients with scleroderma: pregnancy before scleroderma (A1) and pregnancy after
scleroderma (A2). The presence of clinical problems during pregnancy and the
outcome of scleroderma were collected in a questionnaire. Differences in the
frequencies of complications were analyzed using the U Mann-Whitney, the chi
square or Fisher's exact test when necessary. RESULTS: The frequency of global
fetal complications was increased in patients group, but there was no
significantly increased frequency when variables were analyzed independently:
number of births, miscarriages, fetal deaths, preterm births and low weight full
term babies. There was no increased frequency of renal crisis, hypertension or
eclampsia. Differences between diffuse and limited subsets were no observed.
Improvement of scleroderma was seen in only 3 patients and worsening of skin
thickening was experienced by 2 patients. CONCLUSIONS: The pregnant scleroderma
patients are a group with high risk pregnancies and therefore well-supervised
pregnancies are necessary.
PMID- 10680139
TI - [The diet rich in monounsaturated fat modifies in a beneficial way carbohydrate
metabolism and arterial pressure].
AB - OBJECTIVE: Two dietary regimens recommended for the reduction of coronary risk,
by way of their effects on lipid profile, are the diet low in saturated fat and a
diet rich in monounsaturated fats (MUFA). However the effects of these diets on
carbohydrate metabolism in healthy subjects are not well known. The objective of
this study was to compare the effect of both diets on various parameters of
carbohydrate metabolism. METHODS: 41 healthy young males were submitted to 3
consecutive diets, each for a duration of 4 weeks. The first diet was rich in
saturated fat (SAT) (38% fat, 20% saturated). The second was rich in
carbohydrates following the recommendations of the NCEP-I (National Cholesterol
Education Program type I) (28% fat, 47% carbohydrates). The last one was a diet
rich in monounsaturated fatty acids (38% fat, 22% MUFA). At the end of each
dietary period, blood pressure (BP) and blood levels of glucose, insulin and free
fatty acids were determined. 29 subjects were also submitted to an oral glucose
tolerance test (OGTT) at the end of each diet. RESULTS: The SAT diet induced the
highest levels of insulin after the OGTT. The consumption of the MUFA diet
determined the lowest levels of fasting blood glucose (-0.60 mmol/l [13%], p <
0.0002), insulin (-9 microUl/ml [47%], p < 0.0002) and free fatty acids (-0.11
mmol/l [24%], p = 0.006), compared to the NCEP-I diet. Systolic and diastolic
blood pressure were higher in the NCEP-I diet than during the other periods (SBP:
+6 mmHg compare with SAT [5%], p = 0.0001; and +5 mmHg compare with MUFA [4%], p
= 0.0001; DBP: +20 mmHg compare with MUFA [27%], p = 0.0001) and +6 mmHg compared
with SAT [8%], p = 0.0001). CONCLUSION: Of the diets most commonly used for the
treatment and prevention of arteriosclerosis, a diet rich in monounsaturated fats
is the most beneficial for the healthy population from the point of view of
carbohydrate metabolism and blood pressure.
PMID- 10680140
TI - [The determination of arterial pressure by the physician or the nurse: its
relation to ambulatory pressure and left ventricular mass. The MAPA-Madrid Group.
Monitorizacion Ambulatoria de la Presion Arterial (Ambulatory Monitoring of
Arterial Pressure)].
AB - BACKGROUND: In the present study we evaluated the influence of the observer's
status--physician or nurse--on blood pressure levels and the relationship among
clinic blood pressure measurement with ambulatory blood pressure and left
ventricle mass. PATIENTS AND METHODS: Cross sectional study performed in seven
primary care centers. Participating physicians and nurses were trained for blood
pressure measurement prior to the study and subsequently retrained at 3 month
intervals during the study. Patients included in the study were 122 subjects with
mild to moderate hypertension who underwent the following study protocol: a)
measurement of clinic blood pressure by physician and nurse, in an independent
fashion, on 3 visits; b) clinic-epidemiologic questionnaire; c) conventional
hematological and biochemical study; d) electrocardiogram; e) 24-hour ambulatory
blood pressure monitoring, f) M-mode and Doppler echocardiography (only in 58
subjects). RESULTS: Nurse-measured blood pressure levels were higher than those
determined by physicians (mean differences: 3.9 [6.7] mmHg in systolic blood
pressure and 2.6 [5.4] mmHg in diastolic blood pressure). The blood pressure
level differences between the two observers were higher in female patients and
subjects with low educational level, independently of the observer's gender.
Nurse-measured blood pressure was more closely related to ambulatory blood
pressure and left ventricle mass than physician-measured blood pressure.
CONCLUSIONS: Nurse-measured blood pressure levels are lower than those determined
by physicians and more closely related to ambulatory blood pressure and left
ventricle mass than physician-measured blood pressure. These data support that
nurses, instead of doctors, should routinely measure blood pressure in primary
care centers.
PMID- 10680141
TI - [Changes in the lipid profile and thyroid function in adult patients with
hypopituitarism after substitutive treatment with growth hormone].
AB - BACKGROUND: Adult growth hormone (GH) deficiency is associated with changes in
serum lipid levels that can modify after GH substitution. METHODS: We studied 18
patients with GH deficiency treated with GH for 18 or 24 months. RESULTS: A
decrease of total cholesterol, LDL with an increase in HDL without triglycerides
changes was observed. T4 levels decreased and T3 increased. CONCLUSIONS: The GH
substitution treatment in patients with GH deficiency improves the lipid profile
and promotes the T4 to T3 conversion.
PMID- 10680142
TI - [Pregnancy and systemic autoimmune diseases].
PMID- 10680143
TI - [The monitoring of BCR-ABL mRNA by reverse transcription PCR in patients
undergoing allogeneic bone marrow transplantation for acute lymphoblastic
leukemia with a positive Philadelphia chromosome].
AB - BACKGROUND: Allogeneic bone marrow transplantation (BMT) has been performed as
one mode of cure-oriented therapy for Philadelphia chromosome-positive acute
lymphoblastic leukemia (ALL-Ph' positive). However, the clinical significance of
the residual BCR-ABL-positive clones after BMT is still controversial. PATIENTS
AND METHODS: The BCR-ABL gene (p210 and p190) was prospectively studied by nested
RT-PCR in 8 ALL-Ph' positive patients undergoing BMT. RESULTS: All patients
received BMT at the time of clinical remission (CR). However, minimal residual
disease (MRD) was detected in 7 of them. MRD detected just before BMT seems to be
eradicated by BMT protocol. Four patients remained in CR and did not show BCR-ABL
transcripts. Other 4 patients, relapsed, demonstrating MRD, which preceded
recurrence by a median time of 6 weeks. Three relapsed patients showed p190
transcript and only one, p210 type. CONCLUSIONS: The RT-PCR assay appears to be a
useful test for predicting at high risk of relapse after BMT and may identify
patients who might benefit from therapeutic interventions. The finding that the
expression of p190 BCR-ABL may carry an especially high risk of relapse suggests
a different clinical and biologic behaviour between p190 and p210 BCR-ABL.
PMID- 10680144
TI - [Resistance to thyroid hormones].
PMID- 10680145
TI - [The molecular changes in thalassemias in Spain. A review of existing studies].
PMID- 10680146
TI - [Primary hepatic pheochromocytoma].
PMID- 10680148
TI - Management of renal cell carcinoma.
AB - Surgical resection remains the cornerstone of management for localized renal cell
carcinoma. No effective postsurgical adjuvant therapy has been established for
patients with locally advanced disease who are at high risk for recurrence. The
effective treatment of metastatic kidney cancer remains a challenge. Immunologic
therapy with cytokines, such as interferon-alfa (Intron A, Roferon-A) and
interleukin-2 (IL-2 [Proleukin]), benefit relatively small numbers of patients.
Preclinical research and clinical investigations aimed at identifying new agents
and treatment programs with improved antitumor activity against metastases remain
the highest priorities in this refractory disease. New immunologic approaches to
the treatment of both advanced and high-risk postsurgical disease are focusing on
novel vaccine therapies to target both renal epithelial and vascular antigens.
PMID- 10680147
TI - [A neck abscess due to Streptococcus pneumoniae in a man with HIV infection].
PMID- 10680149
TI - Paclitaxel in the treatment of advanced urothelial cancer.
AB - Median survival in patients with advanced urothelial carcinoma continues to be
approximately 1 year following treatment with traditional cisplatin (Platinol)
based regimens, which have substantial toxicity. Thus, research is focusing on
newer chemotherapeutic agents and novel combination regimens to improve outcomes
and tolerability. Paclitaxel (Taxol) demonstrated one of the highest single-agent
response rates (42%) in patients with advanced urothelial tumors, prompting
extensive evaluation of combination regimens, including paclitaxel/platinum-based
doublets or triplets. In many trials, carboplatin (Paraplatin) has been
substituted for cisplatin to produce a more convenient, less toxic regimen. These
trials have demonstrated that paclitaxel/platinum-based combinations are similar
in efficacy to traditional cisplatin-based regimens and are generally better
tolerated. Consequently, paclitaxel-based combinations (e.g.,
paclitaxel/carboplatin) are now considered alternative treatment options for
patients with advanced disease, particularly those who are ineligible for
clinical trials or are unable to tolerate standard cisplatin-based regimens.
Paclitaxel/ifosfamide (Ifex)/cisplatin is another promising alternative regimen
for patients who can tolerate cisplatin-based regimens. An ongoing phase III
trial comparing paclitaxel/carboplatin and MVAC (methotrexate, vinblastine,
Adriamycin, and cisplatin) should clarify the role of paclitaxel-based
combinations. Paclitaxel-based combinations are also under evaluation in the
adjuvant setting, and future trials may assess their potential role as
neoadjuvant therapy or in combination with radiation therapy.
PMID- 10680150
TI - Neurocognitive dysfunction in cancer patients.
AB - Many cancer patients experience impairments of neurocognitive function, including
memory loss, distractibility, difficulty in performing multiple tasks
(multitasking), and a myriad of other symptoms. Patients may also concurrently
suffer from mood disturbance and symptoms that compromise their ability to
function adequately, including fatigue and pain. The etiologies of these problems
are diverse and include the direct effects of cancer within the central nervous
system (CNS), indirect effects of certain cancers (e.g., paraneoplastic brain
disorders), and both diffuse and highly specific effects of cancer treatments on
the brain. In addition to these cancer-related causes, patients may have
coexisting neurologic or psychiatric disorders that affect their cognition and
mood. Careful assessment of patients complaining of neurocognitive or behavioral
problems is essential to providing appropriate interventions and maximizing their
ability to carry out usual activities.
PMID- 10680151
TI - First phase II results of cisplatin/epinephrine in primary liver cancer.
PMID- 10680152
TI - Radiotherapy in the management of plasma cell tumors.
AB - Most patients with plasma cell tumors receive radiation therapy at some time
during the course of their disease. Plasma cell tumors are radio-responsive, but
the systemic nature of the disease in most patients limits the application of
localized irradiation. In patients with solitary plasmacytomas (osseous and non
osseous), radiation therapy is the primary treatment modality. It provides
excellent local control that may translate into a long remission and even cure.
Adequate dose and careful anatomic planning are essential. In patients with
multiple myeloma, effective palliation of pain can be achieved with relatively
small fields and low doses of radiation. Hemibody irradiation has been shown to
provide cost-effective palliation but is associated with toxicity and has failed
to contribute to a more definitive therapeutic approach. Hemibody irradiation is
rarely used today. Total-body irradiation is often employed in conditioning
regimens prior to autologous or allogeneic stem-cell transplantation for multiple
myeloma. However, the magnitude of its contribution to the efficacy of high-dose
programs in multiple myeloma remains to be studied. This article explores the
rationale for and various aspects of providing effective radiotherapy in patients
with plasma cell tumors.
PMID- 10680153
TI - Counseling patients with newly diagnosed prostate cancer.
AB - Almost 200,000 men are diagnosed with localized prostate cancer each year. With
the burgeoning number of treatment options for this disease, the number of
patients seeking second opinions from an increasing variety of medical
specialties will continue to increase. In 1999 (and for the foreseeable future),
there is no single best treatment for any given patient--only options. Each
treatment choice has a variety of advantages, as well as a unique spectrum of
complications and side effects, most of which are poorly quantified and difficult
to compare among treatments. Much more objective data are available regarding the
efficacy and necessity of staging tests for further evaluation of patients after
diagnosis. Current information about both staging and treatment alternatives,
discussed in this article, should be part of the knowledge base of all physicians
treating patients with prostate cancer.
PMID- 10680154
TI - Are 'platins' on the way out in regimens for NSCLC?
PMID- 10680155
TI - Levels of spinal cord injury and predictors of neurologic recovery.
AB - A comprehensive physical examination of the patient with acute spinal cord injury
is essential in determining the initial level of injury and is the most accurate
method of prognosticating neurologic recovery. Understanding neurologic recovery
helps predict ultimate functional capability and needs, and helps evaluate the
effectiveness of pharmacologic and therapeutic interventions.
PMID- 10680156
TI - The respiratory system in spinal cord injury.
AB - Respiratory complications are a leading cause of morbidity and mortality during
the acute and chronic phases after spinal cord injury (SCI). This article reviews
the respiratory impairments resulting from SCI and discusses a range of
management strategies to be considered from the acute care phase through long
term follow up. The treatment of specific complications and preventive measures
are reviewed.
PMID- 10680157
TI - The gastrointestinal system and bowel management following spinal cord injury.
AB - Gastrointestinal system changes following spinal cord injury (SCI) are generally
less obvious than other body system changes. These alterations in function and
the response to management, however, may have profound implications on the
social, emotional, and physical well-being of the individual with SCI. This
article reviews changes in gastrointestinal function following SCI and discusses
current issues related to the management of the neurogenic bowel.
PMID- 10680158
TI - Surgical procedures of the bladder after spinal cord injury.
AB - Surgery of the neurogenic bladder only should be considered after conservative
treatment has failed. The goal of this type of surgery of the neuropathic bladder
is to restore social continence, approximate normal bladder function, and
preserve renal function. Careful selection of procedure and patients, based on
medical status and level of ability, combined with realistic expectations, are
necessary to ensure a successful outcome.
PMID- 10680159
TI - Neurologic recovery and neurologic decline after spinal cord injury.
AB - Physicians caring for patients with spinal cord injury facilitate neurologic
recovery by optimizing nutrition and general health, by coordinating active
exercise and functional training to enhance the underlying synapse growth,
reversal of muscle atrophy, and motor learning, and by controlling interfering
spasticity. SCI physicians also must monitor for neurologic decline during
initial rehabilitation and later in life, diagnose promptly and accurately such
decline, and orchestrate the appropriate intervention.
PMID- 10680160
TI - Musculoskeletal conditions after spinal cord injury.
AB - The impact of musculoskeletal diseases on the overall function and well-being of
a person with spinal cord injury (SCI) cannot be overstated. Even relatively
minor musculoskeletal problems can lead to significant secondary disabilities and
new societal limitations. This article reviews common musculoskeletal problems
and related secondary disabilities associated with SCI. Following an overview on
the epidemiology and pathophysiology of each condition, a typical case is
presented with a discussion about diagnostic challenges and therapeutic options.
PMID- 10680161
TI - Metabolic changes in persons after spinal cord injury.
AB - Persons with chronic SCI have several metabolic disturbances. As a consequence of
inactivity and the body compositional changes of decreased skeletal muscle with a
relative increase in adiposity, a state of insulin resistance and
hyperinsulinemia has been demonstrated to exist, associated with abnormalities in
oral carbohydrate handling. Elevated plasma insulin levels in persons with SCI
probably contribute to the cause of frequent dyslipidemia and hypertension. This
constellation of metabolic changes represents an atherogenic pattern of CHD risk
factors with many of the distinctive features of a cardiovascular dysmetabolic
syndrome that is called syndrome X. Reduction in modifiable risk factors for CHD
should decrease the occurrence of catastrophic cardiovascular events. There is
evidence to suggest that endogenous anabolic hormone levels are depressed in a
proportion of individuals with SCI. Depression of serum testosterone and growth
hormone/IGF-I levels may exacerbate the adverse lipid and body compositional
changes, reduce exercise tolerance, and have deleterious effects on quality of
life. Because of immobilization, individuals with paraplegia have osteoporosis of
the pelvis and lower extremities, and those with tetraplegia also have
osteoporosis of the upper extremities. In addition, there is evidence to suggest
that bone loss progresses with time in persons with chronic SCI. This may be
caused by chronic immobilization per se or may be a consequence of adverse
hormonal changes, including deficiency of anabolic hormones or deficiency of
vitamin D and calcium with secondary hyperparathyroidism. Serum thyroid function
abnormalities resembling the euthyroid sick "low T3 syndrome" have been reported
in those with acute and chronic spinal cord injury. Depressed serum T3 and
elevated rT3 in chronic SCI may be caused by associated illness. Current practice
has been hesitant to treat abnormal serum thyroid chemistries associated with
nonthyroidal illness. Recognition of metabolic abnormalities in individuals with
SCI is vital as a first step in improving clinical care. The application of
appropriate interventions to correct or ameliorate these abnormalities promises
to improve longevity and quality of life in persons with SCI.
PMID- 10680162
TI - Sexual function and infertility following spinal cord injury.
AB - Changes in sexual function and fertility frequently occur following spinal cord
injury (SCI). This article presents an overview of human sexual response and the
changes that occur in that response following SCI. This article addresses the
issues of childbearing for women with SCI, erectile function for men with SCI,
and the issues of fertility and parenting for men and women with SCI.
PMID- 10680163
TI - Pain after spinal cord injury.
AB - Evaluation of pain in a person with SCI should commence with a determination of
the neurologic level and the completeness of injury. The pain then can be
localized to one of three regions: above level, at level, or below level. The
regional pain then should be categorized either as nociceptive or neuropathic
and, after this, subdivided into a specific subtype. An evidence based treatment
plan can be devised depending on the specific subtype, which may include physical
measures, pharmacologic treatments, behavioral interventions, surgery, or an
eclectic combination program. The treatment plan usually can provide some relief
for any of the subtypes, although complete relief often is not possible.
PMID- 10680164
TI - Medical and rehabilitation issues in the care of children with spinal cord
injury.
AB - Rehabilitation of the child with SCI involves setting and changing goals
appropriate to the child's age, development, and family expectations. Unlike
adults with SCI, who may be very close to expected levels of independence at
discharge from inpatient rehabilitation, children often require years of
outpatient therapy to achieve optimal outcomes. Children with SCI also are at
risk for unique complications, which can alter their function. The rehabilitation
community extends beyond the usual hospital based practice to include school and
transitional services. The focus of rehabilitation changes across stages of
development to initially enhance independence in mobility and self-care skills,
and later to promote academic achievement, independent living, and employment.
PMID- 10680165
TI - Seating assessment and planning.
AB - The primary mobility for persons with spinal cord injury (SCI) is seated. This
article addresses ways to maximize the SCI patient's functional mobility with
proper prescription of seating. Critical components of seating are defined and
goals for seating are identified. A format for a postural evaluation as a
foundation for seating intervention is included. An overview of equipment for
seating highlights unique features and components.
PMID- 10680166
TI - Functional neuromuscular stimulation in spinal cord injury.
AB - With recent advances in clinical medicine and biomedical engineering, functional
neuromuscular stimulation (FNS) can now be added to the psychiatric armamentarium
to decrease the debilitating effects of traumatic spinal cord injury. In this
article, the components of FNS systems and their evolution in design are
presented. The clinical implications of FNS are discussed with respect to upper
and lower extremities and bladder applications, and perspectives on future
developments and directions are reviewed.
PMID- 10680167
TI - Developing clinical practice guidelines for spinal cord medicine. Lessons
learned.
AB - This article describes the process used by the Consortium for Spinal Cord
Medicine to develop evidence-based clinical practice guidelines for managing and
treating individuals with spinal cord injury and provides important information
on lessons learned and the potential problems to avoid. Issues to consider during
the guideline development process include topic selection and explication,
methods for selecting the panel chair and panel members, the writing of
recommendations and supporting scientific rationales, peer-reviewing guidelines,
and the process for disseminating, implementing, and evaluating guidelines. The
applicability, advantages, and disadvantages of available evidence and guideline
recommendation grading systems and issues arising from the lack of scientific
evidence supporting particular recommendations are also discussed.
PMID- 10680168
TI - Phytoalexins from crucifers: synthesis, biosynthesis, and biotransformation.
AB - Phytoalexins play a significant role in the defense response of plants. These
secondary metabolites, which are synthesized de novo in response to diverse forms
of stress, including fungal infection, are part of the plants' chemical and
biochemical defense mechanisms. Phytoalexins from crucifers are structurally and
biogenetically related, but display significantly different biological
activities. Here, we review work reporting the chemical structures, synthesis,
biosynthesis and metabolism of cruciferous phytoalexins, as well as their
biological activity towards different microorganisms.
PMID- 10680169
TI - Purification, stabilization and characterization of tomato fatty acid
hydroperoxide lyase.
AB - Fatty acid hydroperoxide lyase (HPO-lyase) was purified 300-fold from tomatoes.
The enzymatic activity appeared to be very unstable, but addition of Triton X100
and beta-mercaptoethanol to the buffer yielded an active enzyme that could be
stored for several months at -80 degrees C. The enzyme was inhibited by
desferoxamine mesylate (desferal), 2-methyl-1,2-di-3-pyridyl-1-propanone
(metyrapone), nordihydroguaiaretic acid (NDGA), n-propyl gallate and butylated
hydroxyanisole, suggesting the involvement of free radicals in the reaction
mechanism and the existence of a prosthetic group in the active center. However,
no heme group could be demonstrated with the methods commonly used to identify
heme groups in proteins. Only 13-hydroperoxides from linoleic acid (13-HPOD) and
alpha-linolenic acid (alpha-13-HPOT) were cleaved by the tomato enzyme, with a
clear preference for the latter substrate. The pH-optimum was 6.5, and for
concentrations lower than 300 microM a typical Michaelis-Menten curve was found
with a K(m) of 77 microM. At higher alpha-13-HPOT concentrations inhibition of
the enzyme was observed, which could (at least in part) be attributed to 2E
hexenal. A curve of the substrate conversion as a function of the enzyme
concentration revealed that 1 nkat of enzyme activity converts 0.7 mumol alpha-13
HPOT before inactivation. Headspace analysis showed that tomato HPO-lyase formed
hexanal from 13-HPOD and 3Z-hexenal from alpha-13-HPOT. A trace of the latter
compound was isomerized to 2E-hexenal. In addition to the aldehydes, 12-oxo-9Z
dodecenoic acid was found by GC/MS analysis. To a small extent, isomerization to
12-oxo-10E-dodecenoic acid occurred.
PMID- 10680170
TI - Hydroquinone: O-glucosyltransferase from cultivated Rauvolfia cells: enrichment
and partial amino acid sequences.
AB - Plant cell suspension cultures of Rauvolfia are able to produce a high amount of
arbutin by glucosylation of exogenously added hydroquinone. A four step
purification procedure using anion exchange, hydrophobic interaction,
hydroxyapatite-chromatography and chromatofocusing delivered in a yield of 0.5%,
an approximately 390 fold enrichment of the involved glucosyltransferase. SDS
PAGE showed a M(r) for the enzyme of 52 kDa. Proteolysis of the pure enzyme with
endoproteinase LysC revealed six peptide fragments with 9-23 amino acids which
were sequenced. Sequence alignment of the six peptides showed high homologies to
glycosyltransferases from other higher plants.
PMID- 10680171
TI - Characterization of isoforms of hexose kinases in rice embryo.
AB - Hexose kinases in rice embryos have been characterized. Six isoforms were
detected: i.e. three glucokinases (GK1-3), two hexokinases (HK1 and HK2) and one
fructokinase (FK1). Out of these, GK3, HK1 and HK2 were inhibited by
mannoheptulose and glucosamine, known inhibitors of hexokinase activity. These
inhibitors are also known to be modulators of sugar sensing processes. The
results suggest that GK3, HK1 and HK2 may play a role in sensing the cellular
sugar status in the rice embryo.
PMID- 10680172
TI - Indoxyl-UDPG-glucosyltransferase from Baphicacanthus cusia.
AB - The enzyme catalyzing the transfer of glucose from uridine diphosphate glucose to
indoxyl yielding the indoxyl glucoside indican was isolated from Baphicacanthus
cusia Bremek (Acanthaceae). The indoxyl-uridine diphosphate glucose (UDPG)
glucosyltransferase was purified to homogeneity in six chromatographic steps. The
decisive step for the recovery of a homogeneous enzyme was the application of
immobilized metal affinity chromatography yielding an 863-fold purified enzyme.
From a total of 60 substances tested, in addition to the natural substrate 3-OH
indole (indoxyl), only 4-OH-, 5-OH-, 6-OH-, and 7-OH-indole were accepted as
substrates by the glucosyltransferase. However, the latter substrates were
metabolized to varying extent. The optimum pH of the enzyme was 8.5, the optimum
temperature was 30 degrees C and the isoelectric point was pH 6.5. The M(r) of
the enzyme was determined to be 60 +/- 2 x 10(3). Indoxyl as substrate yielded a
K(m) of 1.2 mM, while a K(m) of 1.7 mM was found for UDPG.
PMID- 10680173
TI - Sulfation of naringenin by Cunninghamella elegans.
AB - A new flavonoid sulfate, naringenin-7-sulfate, was obtained by fermentation of
naringenin using the fungus Cunninghamella elegans NRRL 1392 in 23% yield.
Structural elucidation of the metabolite was achieved using EIMS, UV, IR, 1D and
2D NMR spectroscopy beside acid and enzyme hydrolyses.
PMID- 10680174
TI - Benzoxazinoids-cyclic hydroxamic acids, lactams and their corresponding
glucosides in the genus Aphelandra (Acanthaceae).
AB - An improved method of sample preparation and simultaneous HPLC separation was
developed that allowed the separation of 2,4-dihydroxy-1,4-benzoxazine-3(4H)-one
(DIBOA), 2,4-dihydroxy-7-methoxy-1,4-benzoxazine-3(4H)-one (DIMBOA), 2-hydroxy
1,4-benzoxazine-3(2H)-one (HBOA), 2-hydroxy-7-methoxy-1,4-benzoxazine-3(2H)-one
(HMBOA) and their corresponding glucosides as well as the benzoxazolinones BOA
and MBOA. The amount and distribution of these compounds was determined in the
roots of Aphelandra squarrosa and A. fuscopunctata plants. There is a significant
difference in the amount and distribution of this substance class in the two
species analyzed. The results are discussed in relation to their function as
defence compounds and allelochemicals.
PMID- 10680175
TI - Variation of DIMBOA and related compounds content in relation to the age and
plant organ in maize.
AB - We report the variation of all 1,4-benzoxazin-3-one derivatives content
detectable in maize with plant age in roots and aerial parts. Our results show
that the concentration of hydroxamic acids, 2,4-dihydroxy-7-methoxy-1,4
benzoxazin-3-one glucoside (DIMBOA-Glc) and its 8-methoxylated analogue (DIM2BOA
Glc) is high after seed germination and then decreases with plant age.
Nevertheless, these compounds continue to be biosynthesised during 6-10 days
after germination. Variation in concentration of N-O-methylated DIMBOA-Glc
(HDMBOA-Glc) is similar to the one of hydroxamic acids in aerial parts. On the
contrary, in roots, its concentration remains relatively stable with plant age.
After 10 days, HDMBOA-Glc becomes the main compound in roots. This compound is
also present in higher concentration than hydroxamic acids in the oldest leaf of
20-day-old maize. The presence of four other DIMBOA related compounds in maize
plants depends on variety, age and tissue. The role of these compounds in plant
resistance to aphids is discussed.
PMID- 10680176
TI - Trans-4-aminoproline, a phytotoxic metabolite with herbicidal activity produced
by Ascochyta caulina.
AB - A phytotoxic metabolite, characterized through NMR techniques and synthetic
methods as trans-4-aminoproline, was isolated from the culture filtrates of
Ascochyta caulina, a promising mycoherbicide for biological control of
Chenopodium album. The metabolite, which shows interesting phytotoxic properties,
together with ascaulitoxin (recently characterized as N.2-beta-D-glucoside of the
unusual bis-amino acid 2,4,7-triamino-5-hydroxyoctandioc acid) and another
unidentified compound, compose an active fraction of A. caulina culture filtrates
with promising herbicidal properties. When assayed on leaves of host and non host
dicots, including wild and cultivated plants, the trans-4-aminoproline showed a
wide range of toxicity, with leaves of C. album being the most sensitive. Other
interesting aspects were its inefficacy on several monocots, both cultivated and
wild, and its lack of antifungal, antibiotic and zootoxic activities. This is the
first report on trans-4-aminoproline as naturally occurring compound and
phytotoxic metabolite produced by A. caulina.
PMID- 10680177
TI - Phytochelatin homologs induced in hairy roots of horseradish.
AB - When exposed to excess heavy metals, plants induce phytochelatins and related
peptides (all designated as PCAs). Thus, when hairy roots of horseradish
(Armoracia rusticana) were exposed for 3 days to cadmium (1 mM) along with
reduced glutathione (2 mM), PCA induction occurred. Moreover, a new family of
thiol peptides was detected as well as the previously known PCAs, as revealed by
postcolumn-derivatization HPLC. Two were isolated and their structures were
identified as (gamma-Glu-Cys)n-Gln (n = 3 and 4) by electrospray ionization-mass
spectrometer spectra, this being confirmed by chemical synthesis of the peptides.
These new analogs constitute the sixth PCA family identified to date.
PMID- 10680178
TI - Sesqui- and diterpenes from the liverwort Gackstroemia decipiens.
AB - Six rosanes, 5 beta,11 beta-dihydroxy-ros-15-ene, 5 beta,12 beta-dihydroxy-ros-15
ene, 11 beta-hydroxy-7-oxo-rosa-5,15-diene, 1 alpha,5 beta,11 beta-trihydroxy-7
oxo-ros-15-ene, 5 beta,20-epoxy-20-hydroxy-ros-15-ene and 5 beta,20-epoxy-20
methoxy-ros-15-ene along with the enantiomer of the already reported 11 beta
hydroxy-rosa-5,15-diene and the known 5 beta-hydroxy-ros-15-ene have been
isolated from the liverwort Gackstroemia decipiens. Furthermore, the
sesquiterpenes 3-acetoxy-7,11-dihydroxy-farnesa-1,5,9-triene and 1 beta,10 beta
epoxy-nardosin-7,11-diene were identified. Their structures were elucidated by
NMR spectroscopy.
PMID- 10680179
TI - Antinociceptive substances from Incarvillea delavayi.
AB - Antinociceptive activities of an Incarvillea delavayi extract, as well as its
constituents, 8-epideoxyloganic acid and delavayine A, were evaluated in the
acetic acid induced writhing test in mice. An oral administration of the delavayi
extract weakly decreased the number of writhings and stretchings in this test, in
a dose-dependent manner. Furthermore, orally administered 8-epideoxyloganic acid
showed weak antinociceptive activity, whereas administration by subcutaneous
injection did not. However, subcutaneous injection of delavayine A, a novel
monoterpene alkaloid, showed a more significant level of antinociceptive
activity.
PMID- 10680181
TI - Polar glycerolipids of Chlamydomonas moewusii.
AB - The fatty acid and polar lipid compositions of the unicellular green alga
Chlamydomonas moewusii were characterized. Since this organism is an important
plant model for phospholipid-based signal transduction, interest was focused on
the lipids phosphatidic acid, phosphatidylinositolphosphate and
phosphatidylinositolbisphosphate. A
phosphatidylinositol:phosphatidylinositolphosphate:
phosphatidylinositolbisphosphate ratio of 100:1.7:1.3 was found. The
polyphosphoinositides accounted for 0.8 mol% of the total phospholipids and their
fatty acid compositions were similar to that of phosphatidylinositol except for
the enrichment of linolenic acid in phosphatidylinositol phosphate. Phosphatidic
acid accounted for 0.67 mol% of the phospholipids. Major structural glycerolipids
were monogalactosyldiacylglycerol (35 mol%), digalactosyldiacylglycerol (15
mol%), sulfoquinovosyldiacylglycerol (10 mol%), diacylglyceryltrimethylhomoserine
(16 mol%), phosphatidylglycerol (9 mol%), phosphatidylethanolamine (8 mol%) and
phosphatidylinositol (6 mol%). Relative changes in the total fatty acid
compositions found during growth on nutrient-limited medium reflected mainly
alterations in the compositions of the chloroplast lipids phosphatidylglycerol
and monogalactosyldiacylglycerol. [32P]Pi-incorporation studies revealed that it
took 6 days before the amount of label in the major phospholipids was
proportional to their abundance.
PMID- 10680180
TI - Study of sesquiterpene lactones from Milleria quinqueflora on their anti
inflammatory activity using the transcription factor NF-kappa B as molecular
target.
AB - In Central America aerial parts of the Asteraceae Milleria quinqueflora are used
in traditional medicine as a remedy for skin infections. Reinvestigation of this
plant afforded thirteen sesquiterpene lactones (Sls), three of them are new. All
isolated Sls were studied for their anti-inflammatory activity using the
transcription factor NF-kappa B as molecular target. NF-kappa B is involved in
the synthesis of inflammatory mediators, such as cytokines and chemokines. NF
kappa B DNA binding was inhibited at micromolar concentrations by all Sls.
PMID- 10680182
TI - Highly oxygenated sesquiterpenes from the liverwort Trocholejeunea sandvicensis.
AB - Four pinguisane type sesquiterpenes were isolated from the liverwort
Trocholejeunea scandvicensis, together with three aromatic compounds. The
structures of the cited compounds were established on the basis of spectroscopic
means. The first two compounds were new sesquiterpenes, while the other compounds
were previously isolated from other liverworts and lichen sp., respectively. The
stereochemistry for lejeuneapinguisanolide was determined by X-ray analysis, a
possible biosynthetic pathway to it was postulated. The other new sesquiterpene
is lejeuneapinguisenone.
PMID- 10680183
TI - Alkaloids from Ruta montana.
AB - Two known and four new quinoline and 4-quinolone type alkaloids were isolated
from Ruta montana collected from Rommani (Morocco). The known compounds were 1
methyl-4-methoxy-2-quinolone and evolitrine. The structures of the new compounds
were established from 1D and 2D NMR experiments including HMQC, HMBC and MS
spectral methods as 2-(nonan-8-one)-(1H)-4-quinolone, 2-(nonan-8-one)-4-methoxy
quinoline, 2-(nonan-8-one)-N-methyl-4-quinolone and 2-(decan-9-one)-N-methyl-4
quinolone.
PMID- 10680184
TI - Benzophenones of Garcinia pseudoguttifera (Clusiaceae).
AB - Four biogenetically related benzophenones have been isolated from the Fijian
Garcinia pseudoguttifera. They are: 6-hydroxy-2,4-dimethoxy-3,5-bis(3-methyl-2
butenyl)benzophenone (myrtiaphenone-A); 2,2-dimethyl-8-benzoyl-7-hydroxy-5
methoxy-6-(3-methyl-2-butenyl)benzopy ran (myrtiaphenone-B); 2,6-dihydroxy-4
methoxy-3,5-bis(3-methyl-2-butenyl)benzophenone (vismiaphenone-C) and a new
benzophenone, 2,2-dimethyl-8-benzoyl-3,7-dihydroxy-5-methoxy- 6-(3-methyl-2
butenyl)-3,4-dihydrobenzopyran (pseudoguttiaphenone-A). Pseudoguttiaphenone-A
could be biogenetically derived from vismiaphenone-C. The major component of G.
pseudoguttifera was identified as eupha-8,24-dien-3 beta-ol.
PMID- 10680185
TI - Tyrosinase catalysed biphenyl construction from flavan-3-ol substrates.
AB - Mushroom tyrosinase catalysed oxidation of three flavan-3-ols, viz. catechin,
fisetinidol and mesquitol, was conducted to construct biphenyl bonds. Exposure of
the flavan-3-ols to tyrosinase and subsequent trapping of the o-quinone
intermediates resulted in the formation of novel flavan-3-ol derivatives, the
structures of which were elucidated by mono- and two-dimensional 1H-NMR
experiments. Application of the methodology resulted in the improved synthesis of
the natural flavan-3-ol dimer, mesquitol-[5-->8]-catechin, previously isolated
from Prosopis glandulosa.
PMID- 10680186
TI - Lipid composition of the extracellular matrix of Botrytis cinerea germlings.
AB - Six simple lipid classes (mono-, di- and tri-acylglycerols, free fatty acids,
free fatty alcohols and wax esters) were identified by TLC in the extracellular
matrix of Botrytis cinerea germlings and the molecular components of each class
were characterized using GC-MS. The relative amounts of fatty acids and fatty
alcohols within each lipid class were determined by GC-FID. Over all the lipid
classes, the most abundant saturated fatty acids were palmitic (ca. 30%) and
stearic acid (ca. 22%). Palmitoleic and oleic acids made up ca. 21% and 24%
(respectively) of the free fatty acids, while erucic (ca. 4.1%) and linoleic (ca.
3.6%) acids were the most abundant unsaturated fatty acids in the acylglycerides.
The acylglycerides also contained almost 35% long chain fatty acids (C20:0 to
C28:0). Six fatty acids were identified which had odd-numbered carbon chain
lengths (C15:0, C17:0, C19:0, C21:0, C23:0 and C25:0). Of these, pentacosanoic
acid made up almost 14% of the fatty acids in the acylglycerides. Three methyl
branched chain fatty acids, namely isopalmitic, isoheptadecanoic and
anteisopalmitic, were identified in the ECM, all in small amounts. Of the fatty
alcohols identified, only palmityl and stearyl alcohols were found in the free
form (ca. 57% and 43%, respectively) but arachidyl alcohol (ca. 47%) and 1
octacosanol (ca. 30%) were the most abundant fatty alcohols found in the wax
ester fraction.
PMID- 10680187
TI - Two flavonoid glycosides from Chenopodium murale.
AB - Two new triglycosides, kaempferol-3-O-[(4-beta-D-apiofuranosyl)-alpha-L-
rhamnopyranoside]-7-O-alpha-L-rhamnopyranoside and kaempferol-3-O-[(4-beta-D
xylopyranosyl)-alpha-L-rhamnopyranoside]-7-O- alpha-L-rhamnopyranoside were
isolated from the methanol extract of Chenopodium murale, together with a known
diglycoside, kaempferol-3-O-beta-D-glucopyranoside-7-O-alpha-L-rhamnopyranoside.
The characterization of the three compounds was achieved by various spectroscopic
methods.
PMID- 10680188
TI - Koelpinin-A, B and C--three triterpenoids from Koelpinia linearis.
AB - Three new triterpenoids, designated as koelpinin-A, B and C and characterised as
28-nor-lup-12,17-dien-3 beta,16 alpha-diol,3 beta-acetoxy-28-nor-lup-12,17-dien
16 alpha-ol and 28-nor-lup-12,17-dien-3 beta-ol-16-one, respectively, together
with 30-nor-lup-3 beta-ol-20-one, taraxeryl acetate and germanicol, were
isolated, from the aerial parts of Koelpinia linearis. 13C-NMR shifts were
assigned after performing APT and DEPT experiments.
PMID- 10680189
TI - Oxidation and epimerization of epigallocatechin in banana fruits.
AB - To examine the metabolism of proanthocyanidins in banana fruit, (-)
epigallocatechin was treated with the homogenate of the fruit flesh to yield (-)
gallocatechin and an oxidation product, 1-(3,4,5-trihydroxyphenyl)-3-(2,4,6
trihydroxyphenyl)-2-hydroxy-1-propan one. The latter product is a stable form of
a key intermediate in the oxidative metabolism of flavan-3-ols, and is also
related to the biogenesis of A-type proanthocyanidins. In addition, treatment of
the reaction mixture with o-phenylenediamine afforded monomeric and dimeric
phenazine derivatives generated by condensation with the o-quinone form of the
oxidation product.
PMID- 10680190
TI - Glucosamine in the treatment of osteoarthritis.
AB - Glucosamine sulfate, a constituent of cartilage, is evaluated for the treatment
of osteoarthritis. Available data suggest that glucosamine decreases pain and
improves function in osteoarthritis. Most of the glucosamine studies have
methodological flaws or used parenteral formulations, making their data difficult
to extrapolate into clinical practice. Glucosamine sulfate is shown to be as good
as ibuprofen for osteoarthritis of the knee. Better designed clinical trials of
glucosamine are needed to identify its role in the pharmacotherapy of
osteoarthritis.
PMID- 10680191
TI - Phyto-anti-inflammatories. A systematic review of randomized, placebo-controlled,
double-blind trials.
AB - Herbal treatments are often used to treat rheumatic symptoms. This systematic
review is aimed at determining the clinical efficacy of this approach. Computer
literature searches are carried out to locate all placebo-controlled, double
blind, randomized trials in this area. Nineteen studies meet the inclusion
criteria. They are heterogeneous in terms of remedies tested, patients treated,
and trial methodology applied. Most of the studies suggest that herbal remedies
can have symptomatic effects beyond placebo. It is concluded that phyto-anti
inflammatories have considerable, albeit under-researched, potential in the
symptomatic treatment of rheumatic disorders.
PMID- 10680192
TI - The Chinese anti-inflammatory and immunosuppressive herbal remedy Tripterygium
wilfordii Hook F.
AB - Various preparations of Tripterygium wilfordii Hook F (TwHF) have been used in
the treatment of a number of autoimmune and inflammatory diseases since the
1960s. Accumulated data from the clinical trials suggest efficacy of this
treatment in a number of rheumatic diseases, including rheumatoid arthritis and
systemic lupus erythematosus. Studies on the relationship of the chemical
components of TwHF and its immunosuppressive and anti-inflammatory effects
suggest that diterpenoid compounds with epoxide groups account for the
therapeutic effects of this herbal remedy. This herbal remedy is therefore a
unique and powerful alternative therapy for autoimmune and inflammatory diseases.
PMID- 10680193
TI - Electromagnetic fields and magnets. Investigational treatment for musculoskeletal
disorders.
AB - Certain pulsed electromagnetic fields (PEMF) affect the growth of bone and
cartilage in vitro, with potential application as an arthritis treatment. PEMF
stimulation is already a proven remedy for delayed fractures, with potential
clinical application for osteoarthritis, osteonecrosis of bone, osteoporosis, and
wound healing. Static magnets may provide temporary pain relief under certain
circumstances. In both cases, the available data is limited. The mechanisms
underlying the use of PEMF and magnets are discussed.
PMID- 10680194
TI - Apheresis.
AB - The removal of pathologic humors by various methods is an ancient medical remedy
used in the management of diseases whose pathophysiology is poorly understood and
whose effective treatment modalities are lacking. The contemporary means for such
an approach involves apheresis, which is now possible due to advances in blood
banking technologies. Apheresis has been used in most of the major rheumatic
diseases, in particular systemic lupus erythematosus and rheumatoid arthritis.
Although numerous case reports describe clinical benefits of apheresis in
rheumatologic disorders, data from clinical trials are discouraging and suggest a
limited role for apheresis in rheumatic disease management.
PMID- 10680195
TI - Photopheresis and autoimmune diseases.
AB - Although several case reports and case series suggest efficacy for photopheresis
in the treatment of autoimmune diseases, few controlled studies have been
conducted to test this hypothesis. After a decade of interest, multiple case
reports, open trials, and one controlled study, the role of photopheresis in
autoimmune disease remains to be established. Controlled multi-center trials in
rheumatoid arthritis, SLE, and scleroderma may be costly but are clearly
necessary for proper evaluation of this therapy.
PMID- 10680196
TI - Manual and manipulation techniques for rheumatic disease.
AB - Manipulation is practiced primarily by chiropractors and osteopaths and is one of
the most commonly utilized alternative treatments for rheumatic diseases. Low
back pain and neck pain are the most frequently treated disorders, but
manipulation is also used to treat a broad range of rheumatic diseases.
Manipulation has been shown to decrease joint pain and normalize function. The
mechanisms of action, however, are not well understood. Current theories propose
an imbalance of muscle activity is a source of pain that manipulation can relieve
through reflexive actions. Such muscle imbalances would exacerbate rheumatic and
arthritic conditions, suggesting that manipulation may be an important therapy
that is appropriate for early conservative care as part of a comprehensive
treatment program.
PMID- 10680197
TI - Chiropractic.
AB - The chiropractic is a health care profession that offers and purveys a
distinctive treatment act. When reduced to its methodology, the chiropractic is
hard pressed to demonstrate effectiveness. But as a treatment act, it has gained
wide acceptance. The challenge raised in this discussion relates to the "moral
hazard" of including the chiropractic treatment act in more general health
insurance policies.
PMID- 10680198
TI - The evidence for acupuncture as a treatment for rheumatologic conditions.
AB - Individuals with rheumatic disorders, particularly those with more severe,
chronic conditions, are likely to be frequent users of complementary and
alternative medical therapies. Although large-scale clinical trials have yet to
be conducted, there is moderately strong evidence that acupuncture may be
effective for treating both osteoarthritis and fibromyalgia. The utility of
acupuncture in treating rheumatoid arthritis has not been demonstrated in large,
randomized controlled trials. Physicians who treat patients with rheumatic
conditions should become knowledgeable about the literature on both the
effectiveness of acupuncture for these conditions as well as its potential to
cause adverse side effects in particular patient groups.
PMID- 10680199
TI - Homeopathy and rheumatic disease.
AB - Despite a growing interest in uncovering the basic mechanisms of arthritis,
medical treatment remains symptomatic. Current medical treatments do not
consistently halt the long-term progression of these diseases, and surgery may
still be needed to restore mechanical function in large joints. Patients with
rheumatic syndromes often seek alternative therapies, with homeopathy being one
of the most frequent. Homeopathy is one of the most frequently used complementary
therapies worldwide.
PMID- 10680200
TI - Yoga.
AB - Yoga is an ancient tradition that has been westernized and often practiced for
its proposed health benefits. Traditional texts describe its benefits for many
types of arthritis. Two limited studies of yoga in osteoarthritis of the hands
and carpal tunnel syndrome show greater improvement in pain than in control
groups. Yoga uses stretching and improves strength so that it theoretically
should be beneficial for some musculoskeletal problems. Yoga merits further study
into its cellular and physiologic effects.
PMID- 10680201
TI - Ayurvedic medicine and arthritis.
AB - The fundamental principles of Ayurveda are briefly reviewed. The ancient
classification of arthritis is described along with the comparisons to the modern
system. Though the diagnosis is historical and clinical, it is based on the
tridosha hypothesis. The Ayurvedic pathogenesis links arthritis to the gut.
Management chiefly consists of diet and lifestyle changes, the panchkarma
process, and herbal drugs. The rasayana concept of immunomodulation is
introduced. Clinical ethno-validation of the ancient therapy is necessary to meet
the modern requirements and set up an interface with modern medicine.
PMID- 10680202
TI - Exercise, education, and behavioral modification as alternative therapy for pain
and stress in rheumatic disease.
AB - Stress and pain mechanisms are complex and share many central nervous system
pathways. Both are critical issues for patients with rheumatoid arthritis and
other connective tissue diseases. The link between stress and neuroendoimmune
function suggests that alternative therapies focusing on improved psychologic and
metabolic function could significantly change patients' pain outcomes. Programs
using alternative therapies such as tai chi and meditation in combination with
traditional medications appear to be beneficial for patients with arthritis.
These individuals appear to live better lives and may have better long-term
outcomes.
PMID- 10680203
TI - Mind-body medicine in rheumatologic disease.
AB - Research over the last 20 years in Mind-Body Medicine has made significant
contributions to the treatment of rheumatic disease. This approach is based on
the concept that patients have the ability to influence their experience of
illness through directed modification of their thoughts, emotions, and behaviors.
This article finds that Mind-Body treatment results in significant, incremental
symptom relief and improvement in disability status and well-being beyond that
achieved through routine medical care. There is also evidence that these
interventions reduce utilization of health care services, despite continuing
progression of disease, a finding that has major economic implications for health
policy.
PMID- 10680204
TI - Prayer and spirituality.
AB - Many patients with arthritis are strongly influenced by religious beliefs and
often participate in religious healing activities such as prayer and worship
attendance. Scientific studies demonstrate, and most patients confirm, that faith
and involvement in religious healing activities can be helpful in preventing and
treating illness, recovering from surgery, reducing pain, and improving quality
of life. To improve the care of patients, clinicians should develop a patient
centered, spiritually sensitive form of medical practice in which religious
issues are addressed gently and appropriately with dignity, respect, and
integrity.
PMID- 10680205
TI - [Tick-borne fever (Ehrlichia phagocytophila infection) on a dairy farm in
Friesland].
AB - Disease outbreaks, associated with ixodid ticks, among cows on a dairy farm in
Friesland, in the north of the Netherlands, were monitored during the summers of
1996, 1997, and 1998. The most important symptoms were a sudden drop in milk
yield, fever, apathy, and problems with locomotion. The diagnosis 'tick-borne
fever' was confirmed by finding Ehrlichia phagocytophila inclusion bodies in
neutrophils of blood smears from sick animals. Significant economic losses due to
the disease were recorded each year. Borrelia burgdorferi, although transmitted
by the same tick, did not seem to be involved. Further research on tick-borne
fever is of particular relevance in connection with recent E. phagocytophila
cases diagnosed in dogs and in a human patient in the Netherlands.
PMID- 10680206
TI - [Plasma prolactin concentration and the effect of metergoline in pseudopregnant
Afghan hounds].
AB - The effects of metergoline, a 5-hydroxytryptamine (serotinin) antagonist, on the
plasma concentrations of prolactin in overtly pseudopregnant Afghan hounds and on
the clinical symptoms of overt pseudopregnancy were studied. Plasma
concentrations of prolactin and progesterone were determined in six Afghan hounds
with signs of overt pseudopregnancy for 2-3 weeks and in three Afghan hounds that
were not pseudopregnant at the time of blood sampling. In the overtly
pseudopregnant bitches the plasma concentrations of prolactin before treatment
(35.5 +/- 8.5 micrograms l-1) were significantly higher than the plasma
concentrations of prolactin of the three bitches that were not pseudopregnant
(6.3 +/- 0.5 micrograms l-1); the latter values were similar to those of non
psueodopregnant beagle bitches during the total luteal phase. The six
pseudopregnant Afghan hounds were treated for 10 days with the antiserotoninergic
drug metergoline. At 2 h after the onset of treatment with metergoline, the mean
plasma concentration of prolactin had decreased to 10.8 +/- 2.9 micrograms l-1.
The plasma concentrations of prolactin continued to decline to 5.4 +/- 1.0
micrograms l-1 at 4 h and to 1.0 +/- 0.1 microgram l-1 during treatment days 3
10. Signs of pseudopregnancy, such as swelling of the mammary glands and digging,
decreased during the treatment period. The treatment was associated with mild
behavioural side effects such as whimpering and aggressiveness. These side
effects are probably not related to suppression of prolactin but are due to a
direct effect on serotoninergic pathways in the brain. It is concluded that high
plasma concentrations of prolactin are associated with the development and
maintenance of pseudopregnancy. The serotonin antagonist metergoline strongly
suppresses plasma concentration of prolactine in pseudopregnant dogs and
decreases the clinical signs of pseudopregnancy.
PMID- 10680207
TI - Initial assessment of patients with neurologic dysfunction.
AB - This article describes a practical approach to the initial assessment of patients
with neurologic dysfunction. First, the patient's clinical signs are determined
by obtaining a medical history and performing an examination. Based on these
results, the disease is localized to a particular region of the nervous system.
Analysis of the neuroanatomic diagnosis in conjunction with the history is used
to establish a list of differential diagnoses. The clinician then recommends
appropriate laboratory tests to confirm or exclude the diagnostic possibilities.
By following a logical process of clinical reasoning, the practitioner is often
able to deduce a clinical diagnosis and prognosis and offer recommendations for
treatment.
PMID- 10680208
TI - Diagnosis and management of urinary retention.
AB - Failure to empty the urinary bladder completely can be attributed to failure of
detrusor contractile function, inappropriate outlet resistance, or both. For each
of these mechanisms, anatomic, neurogenic, and end-organ (myogenic or idiopathic)
abnormalities are possible. The approach to urinary retention involves systematic
consideration of neurogenic, obstructive, and functional causes and requires
understanding of the neurophysiology and pharmacology of micturation.
PMID- 10680209
TI - Selected disorders of muscle and the neuromuscular junction.
AB - A variety of disorders affect the muscles or the neuromuscular junction of dogs
and cats, most often causing weakness, exercise intolerance, and muscular pain or
atrophy. The myopathies are infectious, immune-mediated, inherited or acquired
secondary to systemic disease. Acquired myasthenia gravis is a common disorder of
the neuromuscular junction, which clinically resembles a myopathy. Reaching a
specific diagnosis is essential to determine optimal therapy and prognosis for
each of the commonly recognized disorders.
PMID- 10680210
TI - Intervertebral disk disease.
AB - Neurologic dysfunction is the most common clinical manifestation of
intervertebral disk disease. This article is a comprehensive review of
intervertebral disk disease emphasizing clinical features, diagnosis and
treatment of cervical and thoracolumbar disk disease. Clinical signs are
determined by neuroanatomic localization and severity of spinal cord injury.
Myelography is most commonly used for determining the location and extent of the
disk protrusion/extrusion; however, computed tomography and magnetic resonance
imaging are also common adjunctive and primary diagnostic techniques. Summaries
from recent studies will give the clinician an improved understanding on how to
confront controversial issues regarding prophylactic and therapeutic management
and prognosis.
PMID- 10680211
TI - Degenerative lumbosacral stenosis.
AB - This article reviews the management of degenerative lumbosacral stenosis.
Degenerative lumbosacral stenosis occurs when soft tissue and bony changes,
possibly in conjunction with abnormal motion of the lumbosacral joint, impinge on
the nerve roots or vasculature of the cauda equina. It occurs most frequently in
middle-aged dogs of medium to large breed, especially the German Shepherd dog.
Common signs are lumbosacral pain, lameness, pelvic limb weakness and ataxia, and
urinary incontinence. Diagnosis is based on clinical features and imaging
studies. Decompressive surgery is effective in most patients.
PMID- 10680212
TI - Spinal fracture or luxation.
AB - Spinal trauma is a common cause of spinal cord dysfunction in dogs and cats. When
the spine is injured by exogenous injury, the impact often results in vertebral
fracture or luxation. As each injury is unique, treatment guidelines have to be
individualized to the animal. This article reviews the clinical management
including surgical and nonsurgical treatments for animals with vertebral
fracture/luxation.
PMID- 10680213
TI - Fibrocartilaginous embolism in dogs.
AB - Fibrocartilage embolism originating from the intervertebral disk nucleus pulposus
may induce acute spinal cord infarction. The main characteristics of this
syndrome (acute, nonprogressive transverse myelopathy) are well known by the
clinician. However, the impression that this disease is more commonly encountered
in giant breeds of dogs, with intumescence involvement and loss of nociception
may have been skewed relative to published data. A review of the vascularization
peculiarities of the spinal cord explains the still hypothetical pathogenesis and
helps to understand the diversity of the clinical presentation.
PMID- 10680214
TI - Diskospondylitis and other vertebral infections.
AB - This article discusses infections of the spine, including diskospondylitis,
vertebral osteomyelitis, and vertebral physitis. Spinal pain is the most common
clinical sign. Plain radiography is usually diagnostic; computed tomography and
magnetic resonance imaging are useful when the diagnosis is unclear. Serology for
Brucella canis and cultures of blood and urine are important in identifying the
cause. Appropriate antibiotic therapy is successful in the majority of cases of
bacterial spinal infection.
PMID- 10680215
TI - Idiopathic epilepsy in dogs.
AB - Idiopathic epilepsy is a chronic condition characterized by recurrent seizures
for which there is no identifiable cause. It is the most common neurologic
disorder in the dog. This article discusses the diagnostic evaluation and
rational treatment of dogs with recurrent seizures. Types of seizures, client
education, choice of therapy, use of specific drugs, therapeutic monitoring, and
nondrug treatments are reviewed.
PMID- 10680216
TI - Emergency management of the head trauma patient. Principles and practice.
AB - Management of the severely brain-injured dog or cat can be frustrating,
especially considering the lack of proven effective therapies for head trauma
patients. A working knowledge of the basic pathophysiology of head trauma and
intracranial pressure (ICP) dynamics is essential to the logical treatment of
head traumatized patients. Prevention and correction of hypotension and hypoxemia
are necessary for preventing progressive increases in ICP. Mannitol is
recommended in most cases of severe head trauma, but there is little evidence to
support the use of glucocorticoids in acutely brain-injured dogs and cats. The
role of surgical intervention for head-traumatized dogs and cats is still
uncertain, but may be beneficial in some cases. Aggressive, expedient treatment
and attentive patient monitoring are key aspects of successfully managing canine
and feline head trauma patients.
PMID- 10680217
TI - Vestibular dysfunction.
AB - Vestibular dysfunction can be caused by damage to the peripheral or central
components of the vestibular system. Signs of vestibular disease include ataxia,
head tilt, and abnormal nystagmus. This article reviews the pathophysiology,
diagnosis, and management of common vestibular disorders in dogs and cats.
PMID- 10680218
TI - Is there any health care reform out there?
PMID- 10680219
TI - Initial management of trauma by a trauma team: effect on timeliness of care in a
teaching hospital.
AB - The objective of this study was to determine if timeliness of care would improve
after implementation of the team approach in trauma management in a single
teaching hospital. To make this determination, we used a before-and-after
retrospective cohort series for a 550-bed teaching and tertiary referral hospital
that was not a level 1 trauma center. We included all patients who presented to
the Emergency Department and who were admitted to St. Paul's Hospital because of
trauma during 2 baseline months (May and November 1987; n = 111) and 2 follow-up
months (May and November 1990; n = 142). In 1988, a formal trauma team was
developed to coordinate the care of trauma patients who were seen in the
Emergency Department. Indications for calling the trauma team were based on the
criteria of the American College of Surgeons for triage to a trauma center. We
calculated elapsed time from assessment in the Emergency Department to arrival of
the trauma surgeon, discharge from the Emergency Department, and arrival of the
patient in the operating room (for urgent or emergent surgery). We also
determined the Revised Trauma Score, the Injury Severity Score (1985 version),
the crude mortality ratio, and the Z statistic (population outcome comparison).
After implementation of the trauma team, median elapsed time from initial nursing
assessment in the Emergency Department to arrival in the operating Room for blunt
trauma patients decreased from 11.33 to 4.82 hours (P = .05), but there were no
significant differences in any other measures of timeliness, crude mortality, or
adjusted mortality. We conclude that implementation of a trauma team in a
teaching hospital is associated with a minimal effect on timeliness of care for
admitted trauma patients.
PMID- 10680220
TI - Admission patterns of an urban level I trauma center.
AB - Because trauma admission and hospitalization patterns have profound effects on
the organization and utilization of urban trauma-care systems, the objective of
this study was to identify and analyze these patterns. As an example, admissions
to an urban Level I trauma center were reviewed. Retrospective review of all 2029
trauma admissions to a Level I trauma center was conducted from 1993 to 1996. The
result was that most trauma patients were young (40% < 30 years of age) and male
(74%). Mechanisms of injury were motor vehicle accident (36%), fall (27%),
gunshot (17%), stab (7%), assault (6%), and swimming or diving accident (3%).
Half of the patients were directly admitted from the scene. Injury Severity
Score, length of stay, and mortality were 14.1 +/- 0.3, 10.5 +/- 0.3 days, and
5.1%, respectively. Admissions tended to occur more frequently between 4:00 PM
and midnight (46%), between Friday and Sunday (52%), and between July and October
(41%). The following patterns were identified: admissions per year decreased (
21%) because of reduced penetrating trauma (-43%, P < .01); pediatric patients (<
15 years) had similar incidence of penetrating trauma as adults (ages 15-45).
Length of stay for all mechanisms of injury was not statistically different; most
mortalities occurred within the first day (33%, P < .01) or after 6 days (36%, P
< .01); early mortality was mainly due to penetrating injury (74%, P < .01),
whereas late mortality was related to blunt trauma (92%, P < .01). The conclusion
was that admission and demographic patterns were identified, which may be useful
in the utilization, modification, and future design of trauma systems.
PMID- 10680221
TI - Barriers to control of blood glucose in diabetes mellitus.
AB - The purpose of this study was to characterize the barriers to tight control of
diabetes mellitus. The study collected data from multiple sources at a primary
health care clinic in an academic teaching hospital serving an urban population,
including patients' charts, structured interviews with patients, a survey of
physicians' general perspectives and beliefs concerning diabetes mellitus, and a
physician's structured review of barriers to tight control for individual
patients. One hundred thirty-five patients with scheduled appointments were
eligible for the study, of whom 94% had had a recent hemoglobin A1C (HbA1C).
Seventy-seven of 88 patients (88%) who presented for their appointments consented
to the interview, 48 of 50 providers (96%) returned useable surveys, and
providers completed individual assessments for 96 patients (71%). Patients had a
mean age of 61 years, an average of 7.60 diagnoses, and an average of 8.96
prescriptions. Their diabetes control was less than ideal, with less than 15%
having normal or near normal control and almost a quarter having poor control.
Correlations of HbA1C with age and show rate were seen. Physicians' assessments
showed that motivation and understanding of diabetes and compliance with diet and
medications correlated with diabetes control. Neither patient knowledge nor
physician knowledge appeared to be a problem, nor did either correlate with
diabetes control. The number of barriers to control were many, with over half of
the patients having five or more barriers. Tight control of blood glucose is felt
to be an important aspect of quality care for diabetic patients. In this study, a
representative sample of diabetic patients had less than ideal diabetes control.
This population was receiving their care in an urban setting and had many
comorbid illnesses and many barriers to control. Age, motivation, understanding
of the disease, show rate, and compliance with diet and medications had
statistical correlations with diabetes control. In order to improve the quality
of care for diabetic patients, barriers to care must be addressed.
PMID- 10680222
TI - Differences in outpatient corticosteroid prescribing patterns between attending
and house staff physicians as an indicator of the quality of supervision.
AB - Computerized information systems have become an indispensable source of quality
improvement data in the healthcare field. The degree to which we are successful
in using these systems is limited only by our ability to ask the right questions.
In this study, computerized patient records were used to evaluate the uniformity
in the prescribing patterns for oral corticosteroids among house staff and
attending physicians as a measure of the adequacy of resident supervision in the
outpatient setting. Retrospective analysis of the records of 771 outpatients
receiving prescriptions for oral corticosteroid preparations over 1 year in a
large tertiary-care university-affiliated Department of Veterans Affairs Medical
Center indicated different prescribing patterns for attending physicians and
house staff. Additionally, it was noted that house staff tended to manage more
complex patients than did attending physicians. We further evaluated the clinical
outcomes of these patients to assess the quality, appropriateness, and
comparability of care within cohorts of patients and to determine the degree to
which resident supervision may have affected outcomes. The study results suggest
that there is an opportunity to improve the management of patients treated with
oral corticosteroid therapy by increasing staff physician involvement either
through direct care of the most complex cases or through enhanced resident
supervision.
PMID- 10680223
TI - Commentary: health care reform and specialists: the results are not very
positive!
AB - The present study explored the effects of the current round of health care
reforms on practicing physicians in terms of income, cost of care, and
improvements in the quality of care. Six neurologists from various parts of the
country, all facing widely differing environmental factors, were interviewed. The
results demonstrate that health care reform has forced physicians to work more
hours to maintain their incomes, has done little to control costs, and has
generated little interest in quality improvement plans. In fact, due to referral
patterns, quality levels may have decreased under capitated payment plans. The
conclusion is that health care must be reformed at the local level and involve
physicians with a wide array of specialties.
PMID- 10680224
TI - [Saint Liborius, patron of European urology. Iconography found in Croatia and
Spain].
AB - The discovery made by the group of Dr. Stella Fatovic-Ferencic in Varazdin
(Croatia) of a painting of St. Liborius, patron saint invoked for calculi, and
the painting of the Sevillian school (circa 1700) discovered by another group in
Spain have led to the retrieval of part of the history of European Urology
forgotten 250 years ago. Saint Liborius, bishop of Le Mans (France), died in 397,
at the time the barbarian hordes were ravaging the Roman Empire, which had been
divided into a Western and an Eastern Empire on the death of Theodosius I.
Learning more about St. Liborius is of interest. Here is an example of the Graeco
Roman culture of antiguity that is passed on to the present time. The
significance of both paintings and their differences are described. The article
concludes that on the basis of his biography, St. Liborius should be considered
the patron saint of Urology.
PMID- 10680225
TI - [Innervation of the human adrenal gland].
AB - OBJECTIVE: To study the innervation of the human adrenal gland by
immunohistochemical techniques using monoclonal antibodies against the 200-kDa
phosphorylated neurofilament and S-100 protein, specific markers of the axons and
Schwann cells, respectively. METHODS: 24 specimens of normal adrenal gland from
patients that had undergone radical nephrectomy for a renal tumor were analyzed.
The tissue was embedded in paraffin and prepared for analysis by
immunohistochemical techniques with the indirect peroxidase method using primary
monoclonal antibodies against the 200-kDA phosphorylated neurofilament and
protein S-100. RESULTS: The nerves localized in the adrenal gland form a
subcapsular plexus where branches arise that extend to the medulla and come into
contact with the enterochromaffin cells and medullary neurons. The adrenal
neurons are restricted to the medulla; they are dispersed or form ganglia. The
satellite cells of the medullary ganglia and the sustentacular cells were
positive for S-100. CONCLUSIONS: Most of the nerve fibers penetrate into the
human adrenal gland, extending directly to the medulla apparently without coming
into contact with the cells of the adrenal cortex and form similar connections to
the synaptics with the chromaffin cells and the medullary neurons. The
microganglia of the human adrenal gland are dispersed and comprised of few
neurons.
PMID- 10680226
TI - [Etiology and treatment of penoscrotal skin defects].
AB - OBJECTIVE: The influence of the type and extent of debridement on survival of
patients with Fournier's gangrene and the efficacy of reconstruction with grafts
and residual skin are analyzed. METHODS: The study comprised 43 patients; 35
Fournier's gangrene, 7 trauma and one tumor. The patients with gangrene were
treated by debridement, drainage, amputation and antibiotics. Cutaneous grafts
and residual skin were used to repair the defect in a second stage procedure. No
testicular avulsion was found in the trauma cases. The penile and scrotal
injuries were sutured. One burial and one local flap were performed in two
penoscrotal avulsions. Skin from the penis was used to repair partial scrotal
defects and grafts were applied on the penis. RESULTS: Mortality (21%) was high
in partially debrided Fournier's gangrene, penis amputation and in cases
undergoing only drainage. Skin grafts for total loss of penoscrotal cover and
penile skin flaps for partial scrotal defects achieved good results. Tension
suture was unfavorable in the penis, but was well-tolerated in the scrotum.
Burial and local skin flaps were not good solutions. Poor results were obtained
by conserving residual skin and grafting only the defect. CONCLUSIONS: Early,
wide and repeated debridement procedures reduced the mortality in patients with
gangrene, and the best results of reconstruction were obtained with split
thickness skin grafts for total loss of penoscrotal cover and penile skin flaps
for partial defects of the scrotum.
PMID- 10680227
TI - [Renal angiomyolipoma. Ultrasonography and computerized tomography findings].
AB - OBJECTIVE: To analyze the US and CT findings and their value in the diagnosis and
follow-up of renal angiomyolipoma. METHODS/RESULTS: The clinical features, US and
CT findings in 17 cases of renal angiomyolipoma were reviewed. Patient mean age
was 49.1 years, 15 were asymptomatic and two presented with spontaneous bleeding.
Two patients with Bourneville's disease presented bilateral lesions. The
presumptive diagnosis was based on the US findings in 15 patients and on the CT
findings in 16 patients. The remaining patient was evaluated by MRI. Three
patients underwent partial nephrectomy and three other patients required total
nephrectomy. CONCLUSIONS: Ultrasound is useful in the diagnosis of renal
angiomyolipoma and it is probably the method of choice for follow-up. Two thirds
were echogenic, although an echogenic lesion is not necessarily fat or viceversa.
It is therefore necessary to perform a CT evaluation to make the diagnosis,
especially if the tumor produces symptoms. In this series, detection of fat on CT
evaluation was diagnostic of renal angiomyolipoma, although fatty tissue can also
be found in other tumors or inflammatory lesions. Occasionally, the densitometric
findings may not be conclusive due to the artefact of partial volume. The use of
5 mm slices without contrast and volumetric acquisitions for reconstruction can
enhance the spatial resolution. It must also be taken into account that the fat
content of a lesion can be scanty and may be undetected or not distinguished from
other tumors.
PMID- 10680228
TI - [Development of a clinical pathway for radical prostatectomy].
AB - OBJECTIVE: To describe the clinical care path for retropubic radical
prostatectomy of the La Paz teaching hospital and the results achieved after the
first 6 months. METHODS: We have developed a clinical care path for radical
prostatectomy with a hospital stay of 6 days. Thirty-one patients submitted to
retropubic radical prostatectomy from June to November 1998 were included in the
program. The mean length of total, preoperative and postoperative stay were
analyzed and compared with those of 31 patients who had undergone radical
prostatectomy before the program was developed. Readmissions, adverse effects and
patient satisfaction were also analyzed. RESULTS: Of the 31 patients included in
the clinical care path, 22 (71%) had a stay equal to or less than the program's
length of stay. The mean total, pre and postoperative stay for the group of
patients included in the clinical care path were 6.0 days (SD = 1.1), 1 day (SD =
0.0) and 4.9 days (SD = 1.1), respectively. The length of stay was significantly
longer before the program was developed [mean total 10.2 days (SD = 4.9), mean
preoperative 2.6 days (SD = 2.6) and mean postoperative 7.6 days (SD = 3.6)] (p <
0.001). Twenty-four patients (77.4%) completed the questionnaire on patient
satisfaction, which was highly positive, the overall patient satisfaction rate
being higher than the 90% standard. There were no readmissions or significant
events ascribable to the program. CONCLUSIONS: In our experience, the clinical
care path for radical prostatectomy is a useful tool to reduce the unwanted
variability. Its design is based on the best possible evidence, therefore the
scientific and technical quality, patient satisfaction and efficiency are
enhanced. In our view, our results are attainable and feasible in any health care
setting.
PMID- 10680229
TI - [Expression of protein p53 in superficial transitional carcinoma of the bladder
with differing course].
AB - OBJECTIVE: To determine the prognostic value of p53 protein expression in
relation to progression of superficial bladder cancer. METHODS: A retrospective
study was conducted in which p53 protein was determined in TUR fragments of 18
patients with superficial transitional cell carcinoma of the bladder with no
evidence of tumor progression in the last 6 years and in 13 patients with
superficial tumors that had become invasive. DO-7 monoclonal antibody was
utilized (+if stained nuclei were more than 25%). RESULTS: Expression of p53
protein was found in 9 patients (50%) with bladder tumors that had not progressed
and in 6 patients (46.1%) with bladder tumors that had become invasive (p =
0.83). CONCLUSION: Determination of p53 protein was not related with cancer
progression in this series.
PMID- 10680230
TI - [Clinical and ultrasonographic characteristics of prostatic cancer diagnosed with
transrectal biopsy].
AB - OBJECTIVE: To analyze the clinical, ultrasound and pathological characteristics
of patients with prostate cancer diagnosed by ultrasound-guided transrectal
biopsy who consulted for lower urinary tract symptoms compatible with benign
hyperplasia of the prostate. METHODS: From 1994 to 1998 ultrasound-guided
transrectal biopsy of the prostate was performed in 1,548 patients aged 49-90
years (mean age 70 +/- 7). Of these, 613 (40%) were diagnosed with cancer. Biopsy
was performed in 161 patients (60%) with elevated PSA but no suspicion of cancer
on digital rectal examination, and 452 patients with a suspicious DRE. Only 10 of
these 452 patients (2%) had a PSA value within the normal ranges. Ninety-seven
percent of the patients with cancer were diagnosed at the first biopsy. RESULTS:
The DRE findings were compatible with locally advanced cancer in 25% of the
patients. An echogenic nodule was detected in 79%; the nodule was hypoechoic in
93% of the cases. Ninety-four percent of the patients with a suspicious DRE
versus 37% of those with a normal DRE showed a nodule on ultrasound (p < 0.001).
According to the ultrasound and DRE findings, 41% of the patients had a localized
cancer. Cancer was diagnosed in 70% of the patients with a nodule; 51% of the
cases had high grade carcinoma (score 8, 9 or 10). Sixty percent of the patients
with a suspicious DRE had high grade cancer versus 30% of the patients with a
normal DRE (p < 0.001). Twenty-three percent of the patients underwent radical
prostatectomy. Only 34% of the patients had a localized tumor. CONCLUSIONS: Most
of the tumors of the prostate diagnosed in patients who presented with lower
urinary tract symptoms compatible with BHP were high grade and locally advanced
and therefore not susceptible to cure. PSA determination and digital rectal
examination at the primary care level can be useful in detecting prostate cancer
in the early stages without significantly increasing costs.
PMID- 10680231
TI - [Evidence-based medicine. Usefulness of isolated cystomanometry for the diagnosis
of periurethral detrusor-sphincter dyssynergia in patients with suprasacral
lesion].
AB - OBJECTIVE: To determine the utility of cystomanometry alone in the diagnosis of
periurethral detrusor-sphincter dyssynergia in patients with suprasacral spinal
cord lesion. METHODS: Cystomanometry and selective electromyography were
performed to evaluate the periurethral sphincter of 40 patients (16 female and 24
male; mean age 46.6 years) with suprasacral spinal cord injury diagnosed by
neurological evaluation. RESULTS: The pre-test probability of having dyssynergia
was 0.45. The post-test probability, with cystomanometrically demonstrated
hyperreflexia, was 0.58. The likelihood ratio utilizing cystomanometry alone was
1.69. CONCLUSION: Cystomanometry alone is not useful in the diagnosis of
periurethral detrusor-sphincter dyssynergia in patients with suprasacral spinal
cord injury. Periurethral electromyography should be used in combination with the
foregoing technique.
PMID- 10680232
TI - [Intestinal obstruction secondary to peritoneal carcinomatosis after iatrogenic
perforation during TUR for transitional cell carcinoma of the bladder].
AB - OBJECTIVE: A case of intestinal obstruction following transurethral resection
(TUR) of a locally advanced transitional cell carcinoma of the bladder is
presented. METHODS/RESULTS: The unique features of the present case are
described. Laparotomy was performed and peritoneal carcinomatosis was found.
Renal function became impaired and the abdominal condition persisted. The patient
died five days postoperatively. CONCLUSIONS: Intestinal obstruction following TUR
of transitional cell carcinoma of the bladder is an uncommon complication that is
mainly due to peritoneal seeding following iatrogenic perforation of the tumor or
the bladder wall during resection. Still, TUR is undeniably useful in the
diagnosis, staging and treatment of bladder neoplasm.
PMID- 10680233
TI - [Reiter syndrome: atypical complication of treatment with BCG].
AB - OBJECTIVE: To report a case of Reiter's syndrome, an uncommon complication after
intravesical BCG therapy. The etiology, clinical features, diagnostic
difficulties and treatment of this condition are discussed. METHODS/RESULTS: A 56
year-old patient with superficial bladder carcinoma developed conjunctivitis,
urethritis and arthritis of the right knee and wrist after the fourth BCG
instillation. Other pathologies were ruled out by the clinical and laboratory
findings (synovial fluid, cultures, HLA B-27, RF, ANA). A progressive clinical
improvement was observed when BCG instillation was discontinued and treatment
with indomethacin was started. CONCLUSION: Reiter's syndrome is an infrequent
complication that is not related with the BCG strain utilized. Early diagnosis of
this condition improves response to therapy.
PMID- 10680234
TI - [Giant renal lithiasis].
AB - OBJECTIVE: To describe a case of giant renal calculus. METHODS/RESULTS: A 57-year
old female with a previous history of left renal calculus 30 years earlier,
consulted for episodes of gross hematuria. The imaging studies showed a giant,
spherical calculus, 9 cm in diameter, in the left renal pelvis with
hydronephrosis and remaining renal parenchyma functioning. The patient refused
surgery. CONCLUSION: Giant renal calculi may progress slowly, without symptoms
and without abolishing renal function.
PMID- 10680235
TI - [Surgery of abdominal aortic aneurysm in horseshoe kidney. Report of a case and
review of the literature].
AB - OBJECTIVE: A case of coexistent abdominal aortic aneurysm and horseshoe kidney is
presented. The diagnostic difficulties and the different treatments are
discussed. METHODS/RESULTS: A 55-year-old male patient with aneurysm of the
abdominal aorta associated with a horseshoe kidney is described and the
literature is reviewed. The diagnosis was made by CT and arteriography. Treatment
was by the transperitoneal approach, division of the renal isthmus and placement
of an aortoiliac dacron graft. CONCLUSION: Horseshoe kidney associated with
abdominal aortic aneurysm requiring surgical management is uncommon, but when it
occurs, aortic repair is significantly more difficult.
PMID- 10680236
TI - [Giant condyloma of the penis. Clinical case].
AB - OBJECTIVE: To report an uncommon case of giant penile condyloma. METHODS/RESULTS:
The patient was treated surgically by denudation and fulguration due to the
extent of the penile lesion before treatment with topical podophyllin. The
histopathological study was determinant in the diagnosis and the postoperative
results were excellent. Papillomavirus infection and B. Lowenstein tumor are
discussed. CONCLUSIONS: It is recommended to start treatment with topical
podophyllin. If the lesion does not improve, resection and fulguration of the
condyloma should be performed. The patient should be followed closely for
recurrence.
PMID- 10680237
TI - [Skin metastasis from transitional cell carcinoma of the bladder].
AB - OBJECTIVE: To report an additional case of skin metastasis from transitional cell
carcinoma of the bladder. The clinical features, distribution, differential
diagnosis, treatment and survival are reviewed. METHODS: A 73-year-old patient
with stage pT2 pN0 pMx carcinoma of the bladder is described. The imaging studies
indicated tumor recurrence, but the patient refused reevaluation by endoscopy one
year ago. RESULTS: An erythematous, nodular, indurated lesion extending from the
hypogastrium to the proximal region of both lower limbs was found. The biopsy
findings were compatible with metastatic spread from a carcinoma. CONCLUSION:
Although skin metastasis from bladder carcinoma is rare, the number of cases
reported is increasing. Skin metastasis is generally limited to the advanced
stages of the disease and is an indication of poor prognosis.
PMID- 10680238
TI - [Non-specific granulomatous prostatitis with epithelioid morphology].
AB - OBJECTIVE: To report a case of nospecific granulomatous prostatitis. METHODS: A
57-year-old male presented with urinary symptoms (pollakiuria and dysuria), but
no fever. On physical examination, the prostate was enlarged and indurated. Urine
cultures were negative and blood PSA was slightly elevated. The patient had no
previous history of surgery. RESULTS: The histopathological analysis showed
granulomatous prostatitis with prominent epithelioid histiocytes. Abundant
calculi were also found. The special techniques were negative for fungi and BAAR.
No evidence of neoplasm was found. CONCLUSION: Granulomatous prostatitis can
mimick a carcinoma, clinically and even histologically, particularly in those
cases with prominent epithelioid histiocytes.
PMID- 10680240
TI - A new century for international public health.
PMID- 10680239
TI - Conservative surgery in small renal tumors: our experience.
AB - OBJECTIVE: We evaluated the effectiveness and safety of the nephron-sparing
surgery in the treatment of low stage, easily accessible renal cell carcinoma
versus radical nephrectomy, the "gold standard" therapy according to data in the
literature. METHODS: From 1988 to 1996, 36 patients (11 women and 25 men; mean
age 59.6 years) with a small (< or = 5 cm) solitary renal cell carcinoma and a
normal contralateral kidney were submitted to tumor enucleation through a
transperitoneal approach. Hot ischemia was performed in 14 cases for an average
of 16 minutes. In order to control the extent of surgical resection, in all cases
frozen step sections of surgical margins were submitted to histopathological
examination. The mean follow-up was 40 months. RESULTS: Complete local resection
of the renal cell carcinoma was performed in all patients, with preservation to
the furthest extent of the parenchyma not affected by the disease. Renal function
remained normal in all cases. Bleeding was easily controlled without clamping the
renal artery in 22 cases, while hot renal ischemia was necessary in the remaining
14 cases (mean ischemia time 16 minutes). Average blood loss was 450 cc. Frozen
sections of the surgical margins were negative in all cases. Only one case of
local recurrence was observed one year after the nephron-sparing operation, which
was treated by radical nephrectomy. All patients are alive and cancer-free today.
CONCLUSIONS: Elective tumor enucleation for low stage and easily accessible renal
cell carcinoma can be performed safely and with a low risk of local recurrence.
Definition of the appropriate pre-operative diagnostic approach, maximum tumor
size, surgical mini-invasive approach and a longer follow-up are required before
this procedure can be widely recommended.
PMID- 10680241
TI - WHO and the International Diabetes Federation: regional partners.
PMID- 10680242
TI - Incidence and outcome of injury in Ghana: a community-based survey.
AB - Injury is an increasingly significant health problem in most low-income
countries. However, strategies for preventing injury have not been well
addressed. The present study was carried out to measure the incidence and outcome
of various mechanisms of injury in Ghana in order to provide data for use in
developing priorities for injury prevention efforts. For this purpose, using two
stage cluster sampling and household interviews, we surveyed 21,105 persons
living in 431 urban and rural sites. During the preceding year, 1609 injuries
resulting in one or more days of loss of normal activity were reported. Injury
related mortality was slightly higher in the urban (83 per 100,000) than in the
rural area (53 per 100,000). However, the burden of disability from nonfatal
injuries, as assessed by disability days, was higher in the rural (4697
disability days per 1000 person-years) than in the urban area (2671 days per 1000
person-years). Based on incidence rates and disability times, the major types of
injury in the urban area were transport-related injury and falls. In the rural
area, agricultural injuries predominated, followed by falls and transport-related
injury. In rural and urban areas combined, 73% of motor vehicle-related injuries
involved commercial vehicles. In this and other similar developing-country
settings, injury prevention efforts should focus on falls and on transport safety
in both urban and rural areas, with special attention being paid to commercial
vehicles. In rural areas, agricultural injuries contributed the largest burden of
morbidity, and should be a priority for prevention efforts.
PMID- 10680243
TI - Prevalence of hepatitis C virus antibodies and genotypes in asymptomatic, first
time blood donors in Namibia.
AB - Reported is the prevalence of hepatitis C virus (HCV) in Namibia as determined
using a third-generation enzyme-linked immunosorbent assay (ELISA) on samples of
blood collected from all asymptomatic, first-time blood donors between 1 February
and 31 July 1997 (n = 1941). The HCV seroprevalence was 0.9% (95% confidence
interval (CI): 0.5-1.5%) and no associations were detected between a positive HCV
serostatus and the person's sex, region of residence, or previous hepatitis B
exposure or hepatitis B carrier status, as determined by hepatitis B surface
antigen (HBsAg). The only significant association in a logistic regression model
was an increase in HCV positivity with increasing age (P = 0.04). Viral RNA was
amplified from 2 out of 18 (11.1%) specimens that were ELISA positive. Genotyping
of these specimens, by restriction fragment length polymorphism (RFLP), showed
the presence of genotypes 5 and 1a. The positive predictive value of using HBsAg
positivity as a surrogate screening marker for HCV in Namibian blood donors was
poor (1.6%), with low sensitivity (16.7%) and specificity (89.3%), and detecting
only 3 out of 18 serologically HCV-positive specimens. The results of this first
study of the prevalence and epidemiology of HCV infection in Namibia suggest that
donor blood should be screened for HCV by ELISA in order to prevent the
transmission of hepatitis C virus.
PMID- 10680244
TI - Assessment of cell culture and polymerase chain reaction procedures for the
detection of polioviruses in wastewater.
AB - WHO considers that environmental surveillance for wild-type polioviruses is
potentially important for surveillance for acute flaccid paralysis as a means of
confirming eradication of poliomyelitis. The present study investigated methods
for detecting polioviruses in a variety of water environments in South Africa.
Most polioviruses were isolated on L20B mouse cells, which, however, were not
selective: 16 reoviruses and 8 enteroviruses, apparently animal strains, were
also isolated on these cells. Vaccine strains of polioviruses were isolated from
surface waters during and shortly after two rounds of mass vaccination of
children in an informal settlement where there was no sewerage. The results
demonstrated the feasibility of poliovirus surveillance in such settlements. It
was also evident that neither poliovirus vaccine strains nor other viruses were
likely to interfere significantly with the detection of wild-type polioviruses.
Optimal isolation of polioviruses was accomplished by parallel inoculation of
L20B mouse cells and at least the PLC/PRF/5 human liver and buffalo green monkey
(BGM) kidney cell lines. Analysis of cell cultures using the polymerase chain
reaction revealed that 319 test samples contained at least 263 human
enteroviruses that failed to produce a cytopathogenic effect. This type of
analysis thus significantly increased the sensitivity of enterovirus detection.
PMID- 10680245
TI - Status of national diabetes programmes in the Americas.
AB - Reported are the responses in the latter half of 1997 of all ministries of health
in the Region of the Americas to the Declaration of the Americas on Diabetes,
which was adopted by the Directing Council of the Pan American Health
Organization (PAHO) in 1996 as a basis for national programme development in
diabetes. The short-term targets were the designation of national focal points,
the preparation of national estimates of the disease burden, and the development
and implementation of national strategies and plans to deal with diabetes. The
survey found that most countries recognized diabetes as a significant public
health problem. In terms of global relevance, a number of lessons have been
learned from this exercise: the role of broadly based participation in gaining
recognition at the national health policy level; the wide acceptance of an
integrated programme model; the relevance of process-related targets to achieve
short-term success; and the critical role of having a designated focal point
within the managerial approach.
PMID- 10680246
TI - Linking the integrated management of childhood illness (IMCI) and health
information system (HIS) classifications: issues and options.
AB - Differences in the terms used to classify diseases in the Integrated Management
of Childhood Illness (IMCI) guidelines and for health information system (HIS)
disease surveillance could easily create confusion among health care workers. If
the equivalent terms in the two classifications are not clear to health workers
who are following the guidelines, they may have problems in performing the dual
activities of case management and disease surveillance. These difficulties could
adversely affect an individual's performance as well as the overall effectiveness
of the IMCI strategy or HIS surveillance, or both. We interviewed key informants
to determine the effect of these differences between the IMCI and HIS
classifications on the countries that were implementing the IMCI guidelines. Four
general approaches for addressing the problem were identified: translating the
IMCI classifications into HIS classifications; changing the HIS list to include
the IMCI classifications; using both the IMCI and HIS classification systems at
the time of consultations; and doing nothing. No single approach can satisfy the
needs of all countries. However, if the short-term or medium-term goal of IMCI
planners is to find a solution that will reduce the problem for health workers
and is also easy to implement, the approach most likely to succeed is translation
of IMCI classifications into HIS classifications. Where feasible, a modification
of the health information system to include the IMCI classifications may also be
considered.
PMID- 10680247
TI - Strategies for safe injections.
AB - In 1998, faced with growing international concern, WHO set out an approach for
achieving injection safety that encompassed all elements from patients'
expectations and doctors' prescribing habits to waste disposal. This article
follows that lead and describes the implications of the approach for two
injection technologies: sterilizable and disposable. It argues that focusing on
any single technology diverts attention from the more fundamental need for health
services to develop their own comprehensive strategies for safe injections.
National health authorities will only be able to ensure that injections are
administered safely if they take an approach that encompasses the whole system,
and choose injection technologies that fit their circumstances.
PMID- 10680248
TI - Auto-disable syringes for immunization: issues in technology transfer.
AB - WHO and its partners recommend the use of auto-disable syringes, "bundled" with
the supply of vaccines when donor dollars are used, in all mass immunization
campaigns, and also strongly advocate their use in routine immunization
programmes. Because of the relatively high price of auto-disable syringes, WHO's
Technical Network for Logistics in Health recommends that activities be initiated
to encourage the transfer of production technology for these syringes as a means
of promoting their use and enhancing access to the technology. The present
article examines factors influencing technology transfer, including feasibility,
corporate interest, cost, quality assurance, intellectual property
considerations, and probable time frames for implementation. Technology transfer
activities are likely to be complex and difficult, and may not result in lower
prices for syringes. Guidelines are offered on technology transfer initiatives
for auto-disable syringes to ensure the quality of the product, the reliability
of the supply, and the feasibility of the technology transfer activity itself.
PMID- 10680249
TI - Anthropotechnological analysis of industrial accidents in Brazil.
AB - The Brazilian Ministry of Labour has been attempting to modify the norms used to
analyse industrial accidents in the country. For this purpose, in 1994 it tried
to make compulsory use of the causal tree approach to accident analysis, an
approach developed in France during the 1970s, without having previously
determined whether it is suitable for use under the industrial safety conditions
that prevail in most Brazilian firms. In addition, opposition from Brazilian
employers has blocked the proposed changes to the norms. The present study
employed anthropotechnology to analyse experimental application of the causal
tree method to work-related accidents in industrial firms in the region of
Botucatu, Sao Paulo. Three work-related accidents were examined in three
industrial firms representative of local, national and multinational companies.
On the basis of the accidents analysed in this study, the rationale for the use
of the causal tree method in Brazil can be summarized for each type of firm as
follows: the method is redundant if there is a predominance of the type of risk
whose elimination or neutralization requires adoption of conventional industrial
safety measures (firm representative of local enterprises); the method is worth
while if the company's specific technical risks have already largely been
eliminated (firm representative of national enterprises); and the method is
particularly appropriate if the firm has a good safety record and the causes of
accidents are primarily related to industrial organization and management
(multinational enterprise).
PMID- 10680250
TI - Humanitarian assistance should include aspects of sexuality.
PMID- 10680251
TI - Survey of malaria treatment and deaths.
PMID- 10680252
TI - Influenza surveillance and dissemination of information to health professionals
and the general public in the province of Quebec.
PMID- 10680253
TI - Transfusion-transmitted babesiosis in Ontario: first reported case in Canada.
PMID- 10680254
TI - World survey of rabies, 1997.
PMID- 10680255
TI - CPHA and the global effort to strengthen responses to HIV/AIDS.
PMID- 10680256
TI - Incomes and outcomes.
PMID- 10680257
TI - [Social capital, health promotion and population health].
PMID- 10680258
TI - Widening regional inequality in premature mortality rates in Manitoba.
AB - OBJECTIVE: To describe regional trends in premature mortality in Manitoba.
DESIGN: Comparison of all-cause and cause-specific mortality of persons less than
age 75 in 11 Regional Health Authority populations over two time periods: 1985-89
and 1990-94. RESULTS: The provincial premature mortality rate declined over the
two time periods (4.00/1,000 to 3.72/1,000). Declines were also observed in 9 of
11 regional populations. Premature mortality increased, however, in the 2
regional populations with the highest mortality rates in the first observation
period. CONCLUSION: Declining premature mortality in low mortality populations
and rising premature mortality in high mortality populations has resulted in a
widening of regional mortality rates in Manitoba. Recent policy initiatives in
many provinces, including the devolution of authority for the management and
delivery of health services and the implementation of population need-based
funding formulas to share health care resources among regional health
authorities, if implemented, have the potential to partially mitigate the
processes producing these widening regional health inequalities.
PMID- 10680259
TI - Trends and variations in perinatal mortality and low birthweight: the
contribution of socio-economic factors.
AB - OBJECTIVE: To examine trends and regional variations in perinatal mortality and
low birthweight (LBW) and regional variations in socio-economic risk factors.
METHODS: Population-based study of Central West Region of Ontario with
approximately 28,000 births annually during the period 1988-1995 using vital
statistics records and Census data. RESULTS AND CONCLUSIONS: There was no
significant change in the perinatal mortality rate averaging 9.4 per 1,000 births
per year. The LBW rate increased from 49.7 to 54.8 per 1,000, while the
prematurity rate increased from 56.1 to 75.8 per 1,000. Significant variation
occurred in outcomes among different regions, which was partially explained by
socio-economic factors. The increases in LBW and prematurity rate emphasize the
need for effective targeted services and programs. In their planning and
implementation, regional variations in socio-economic factors, and other factors
such as: the availability and utilization of services and barriers to access in
services, require further evaluation and consideration.
PMID- 10680260
TI - Charitable food assistance: what are food bank users receiving?
PMID- 10680261
TI - Geographic origin and risk for congenital infection in a Canadian inner city:
findings and implications for policy.
AB - This study examines associations between geographic origin and risk for
congenital infections, through a chart review of women from the St. James Town
area of Toronto delivering at Wellesley Hospital in 1996. Foreign-born women (n =
203) were significantly less likely than Canadian-born women (n = 53) to be HBsAg
negative (187/193 vs. 48/48; RR = 0.97, 95% CI 0.94-0.99). There was no
significant difference in rubella seronegativity, but rubella immunity was
unacceptably low in both groups (less than 90%). A number of rubella non-immune
women had delivered previously in Canada. Procedures must be implemented to
ensure completion of hepatitis B immunization series in affected newborns, and
rubella immunization in seronegative women prior to discharge. As well, updating
immunization status most become a routine part of the immigration medical
examination.
PMID- 10680262
TI - The effect of tuberculosis and tuberculosis contact tracing on school function:
an exploratory focus group study.
AB - SETTING: Selected schools in East York, an ethnically diverse municipality of
110,000 people within Toronto. OBJECTIVE: To explore school staff's attitudes and
beliefs about the nature of tuberculosis and its possible effect on the function
and culture of schools. DESIGN: Four focus groups of 6-8 school staff, lasting
from 1 to 1.5 hours, were held in the spring of 1997 at four different schools
deemed to be at high risk for tuberculosis contact tracing. RESULTS: The study
identified the following dominant themes: fear of tuberculosis and its impact on
school, lack of knowledge and the need for education concerning tuberculosis, and
issues in multiculturalism. CONCLUSION: Tuberculosis was perceived by staff of
East York schools to be a source of fear. Lack of accurate and reliable
information concerning tuberculosis contributes to this situation. Staff
identified age-specific and culturally relevant, educational initiatives as means
to reduce this fear.
PMID- 10680263
TI - [The importance of dietary sodium: the time has come for a public health
intervention].
AB - In recent years, many studies have been published regarding the link between
sodium intake and high blood pressure. Canadian, American and WHO Guidelines on
the treatment of hypertension all indicate salt reduction as an efficient non
pharmacologic recommendation. However, due to the lack of clear and specific
Canadian legislation on food labelling, consumers are not able to make informed
choices of food products on the basis of salt content. The time has come for
public health experts to join this debate.
PMID- 10680264
TI - Sources of cigarettes for high school students in two Ontario counties:
implications for developing a community response.
PMID- 10680265
TI - A telephone-based support program for over-the-counter nicotine patch users.
PMID- 10680266
TI - The first reported cluster of food-borne cyclosporiasis in Canada.
AB - INTRODUCTION: Prior to 1996, sporadic cases of cyclosporiasis in Canada were most
often associated with foreign travel and outbreaks throughout the world were
associated with contaminated drinking water. In May 1996, the North York Public
Health Department was notified of three laboratory-confirmed cases of
cyclosporiasis among persons who attended a luncheon at a religious institution.
A ceremonial bath (mikvah) was initially identified as a possible source of
exposure to contaminated water. METHODS: Guests of a luncheon were interviewed
regarding food, beverage and water exposure. The institution kitchen and water
sources were inspected and environmental testing was performed. RESULTS: Eating
strawberry flan, decorated with rasberries and blueberries, was associated with
developing illness (relative risk = 2.13, p = 0.02). There was no evidence that
water exposure was associated with illness. DISCUSSION: This event was the index
Canadian cluster of a widespread North American outbreak associated with imported
Guatemalan raspberries. The local investigation highlights the role of public
health departments in multijurisdictional food-borne outbreaks of emerging
pathogens.
PMID- 10680267
TI - Infant feeding practices in Ottawa-Carleton: the introduction of solid foods.
AB - Infant feeding guidelines regarding the introduction of solid foods are generally
not well known in Canada. The guidelines recommend that solid foods be introduced
between four to six months of age, depending on the developmental readiness of
the infant. In order to understand the underlying factors and patterns which
contribute to the introduction of solid foods in infants, data were analyzed from
three cross-sectional surveys of parents of six-month-old infants from the Ottawa
Carleton region (n = 373, 1988; n = 330, 1992; n = 338, 1996) conducted by the
Ottawa-Carleton Health Department. Multivariable analysis showed that mothers
who: did not breastfeed, were younger, had lower education, smoked or had
partners that smoked, and lacked support after birth, were more likely to
introduce solid foods before four months of age. These data support the need for
nutrition education programs to increase adherence to the new Nutrition for
Healthy Term Infants guidelines.
PMID- 10680268
TI - Breastfeeding outcomes of women following uncomplicated birth in Hamilton
Wentworth.
AB - OBJECTIVE: To examine infant feeding practices up to 8 weeks postpartum in
Hamilton-Wentworth. METHODS: A cross-sectional survey of 227 women using a pre
discharge, self-administered questionnaire, medical record review and follow-up
telephone interview. RESULTS: Breastfeeding initiation rate was 85%. By 6-8 weeks
postpartum, 30% of women had stopped breastfeeding; 55% had switched to formula
within the first 14 days. Infants who did not receive supplementation in hospital
were 2.49 times more likely than infants who received supplementation to
breastfeed for at least 6 weeks. Although 54% of mothers who initiated
breastfeeding reported receiving formula gift packs, no association was found.
CONCLUSIONS: The breastfeeding initiation rate appears to have increased in
Hamilton-Wentworth since 1995. However, this study reinforces the need to address
early cessation and infant supplementation, and raises concern about violation of
the WHO/UNICEF International Code of Marketing of Breastmilk Substitutes through
mailing of formula coupons.
PMID- 10680269
TI - Newfoundland Panel on Health and Medical Care--adult health survey.
AB - An adult health survey was undertaken on the island portion of the Province of
Newfoundland as part of the Newfoundland Panel on Health and Medical Care. This
study aims to develop models of medical care utilization over a seven-year
period, before and after a major restructuring of the provincial health care
system. A health survey on a large sample (11,789 individuals) permits both
descriptive and explanatory analysis at the regional level. The results of the
survey are presented first in a descriptive format, as they were included in
reports for policy makers and managers, using administrative aggregations. To
study regional differences, descriptive and multivariate analyses were done on an
aggregation by an urban dimension, which divides the island into three areas. As
expected, there were major differences across regions, and complex interactions
on selected variables. The usefulness of health surveys for planning and
evaluation of health reform is discussed.
PMID- 10680270
TI - The effect of season and weather on suicide rates in the elderly in British
Columbia.
AB - OBJECTIVES: The authors examined the relationship of suicide in the elderly (65
years and older) to season and weather and compared it to that in the younger
population (10-64 years). METHODS: Information on suicides and on weather was
obtained for British Columbia for the period 1981 to 1991. The association of
suicide with season and weather was assessed using Poisson regression. RESULTS:
Whereas younger suicides were associated with season, showing a spring-summer
peak, elderly suicides were associated with actual weather. They increased with
higher mean daily temperature for the current month (RR = 1.16, 95% CI 1.05-1.28
for each 2.5 degrees C change in mean temperature), and with lower mean daily
temperature for the preceding three months (RR = 1.12, 95% CI 1.01-1.23).
CONCLUSIONS: Elderly suicide rates appear to be affected by deviations of monthly
mean temperature from values expected for that time of year. Increased support by
service agencies at times of predicted high risk is suggested.
PMID- 10680271
TI - Routine child health care in the emergency department.
PMID- 10680272
TI - Is God good for your health? The role of spirituality in medical care.
AB - Many studies have found that religious belief and practice have a positive effect
on physical and mental health, although the topic needs more research. As
religious beliefs may affect both health and health-promoting behavior,
physicians should try to understand their patients' beliefs.
PMID- 10680273
TI - Are strict vegetarians at risk of vitamin B12 deficiency?
PMID- 10680274
TI - Is there an advantage to combination therapy with ACE inhibitors and angiotensin
II-receptor blockers?
PMID- 10680275
TI - Antiviral agents for treating influenza.
AB - The new neuraminidase inhibitors zanamivir and oseltamivir are important
additions to the treatment of influenza, being the first class of agents active
against both influenza A and influenza B. The decision to use these agents rather
than amantadine or rimantadine, which are effective only against influenza A,
should be based on the age of the patient, antiviral activity, side effect
profile, ease of administration, drug interactions, and cost. All of these agents
are effective only when started within 24 to 48 hours of onset of symptoms. To
avoid inappropriate use of these agents, treatment should be continued only in
patients with a confirmed diagnosis of influenza. Although effective in
decreasing symptoms, none of these agents prevent pneumonia or hospitalization
secondary to influenza.
PMID- 10680276
TI - The spectrum of nonalcoholic fatty liver disease: from steatosis to nonalcoholic
steatohepatitis.
AB - Nonalcoholic fatty liver disease (NAFL) has been recognized only in the past 20
years. Autopsy studies indicate it is remarkably common, especially among obese
persons and patients with type 2 diabetes. Although fatty liver alone is usually
benign, an identifiable subset of patients may be at risk of progression to
cirrhosis and liver failure. The role of liver biopsy is controversial. No
specific, effective therapy as yet exists, although management of weight, lipid
levels, and glucose levels is recommended.
PMID- 10680277
TI - Psoriasis: a clinical update on diagnosis and new therapies.
AB - Psoriasis varies widely in its clinical expression, from a single fingernail pit
to widespread disfiguring skin lesions and disabling arthritis. Treatments are
divided into five levels, providing a framework for approaching this disease
according to severity and recalcitrance to previous treatment. Powerful
immunosuppressive drugs are showing some success in treating severe cases.
PMID- 10680278
TI - Brain metastases: presentation, evaluation, and management.
AB - Brain metastases are a common and devastating consequence of cancer and carry a
poor prognosis. Nevertheless, physicians can serve their patients well by
suspecting, detecting, and treating them appropriately.
PMID- 10680279
TI - Glycoprotein IIb/IIIa inhibitors in acute coronary syndromes.
AB - Glycoprotein (GP) IIb/IIIa inhibitors are potent antiplatelet agents and
represent an exciting breakthrough in the treatment of acute coronary syndromes.
However, their safety and cost-effectiveness require further investigation, and
more information on risk stratification is needed to clarify which patients
benefit the most from empiric use of these agents.
PMID- 10680280
TI - Was it preventable? The comprehensive review of inmate suicide.
PMID- 10680281
TI - Befriending mental patients: experience in the Ukraine.
PMID- 10680282
TI - I.A.S.P. guidelines for suicide prevention. I.A.S.P. Executive Committee.
AB - There are a number of ways in which suicide can be prevented. Broad social issues
can be influenced by firm advocacy for change in appropriate areas in different
countries, such as by restricting access to specific means of suicide and by
enhancing health and social services in general. At the individual level, after
the establishment of rapport, there should be screening for the presence of
specific mental disorders, which, if present, should be treated vigorously. If
medication is indicated, the safest drug should be prescribed, although it is
emphasized that even if drugs are utilized, nondrug treatment is important for
every suicidal person. The focus of supportive therapy, which can be provided by
both the helping professions and volunteer organizations, should be the provision
of hope for the future, the enhancement of independence, and the learning of
different ways of coping with the inevitable stressors of everyday life. If these
guidelines are followed, there is every reason to believe that an impact can be
made upon the worldwide problem of suicidal behavior.
PMID- 10680283
TI - Incarcerated adolescents' distress and suicidality in relation to parental
bonding styles.
AB - This study examines the relationships between the bonding style of an
incarcerated adolescent with parents and his/her current feelings of self-esteem,
hopelessness, and suicidal thoughts and attempts. It also investigates
differences between bonding to mother and bonding to father. Some 296
incarcerated adolescents were interviewed using the Parental Bonding Instrument.
Significant relationships were found between youths' self-esteem, hoplessness,
and suicidal behavior and their bonding style. Youths whose parent(s) had a
parental bonding style of affectionless control reported the greatest distress,
and youths whose parent(s) had an optimal bonding style reported the least
distress. Differences were found between bonding styles with the mother and with
the father. Attachment theory may be useful in targeting incarcerated youths who
have affectionless control bonding with parent(s) for special interventions since
these youths are most at risk for psychosocial problems.
PMID- 10680284
TI - Risk assessment and suicide prevention in primary care.
AB - General practitioners (GPs) are assumed to occupy an important position in the
prevention of suicide through the introduction of risk assessment techniques
commonly used in psychiatric practice. Despite this theoretical role for primary
care services, it remains unclear how frequently GPs implement risk assessment in
patients who may be vulnerable to suicide. To address this, a retrospective
survey of probable suicides was conducted within a primary care setting utilizing
a questionnaire of GPs who had experienced a patient suicide and was augmented by
hospital and coroners' records. 85% of questionnaires were returned and 61 deaths
were adjudged as suicides during the year long census period. 75% of suicides
were male and 54% were aged under 35.28% were in contact with psychiatric
services prior to death, although 60% had some diagnosis of mental disorder. GPs
had little knowledge of a patient's life circumstances in up to half of cases.
Recording of risk assessment occurred in 38% of subjects, was positively
associated with prior psychiatric contact (p = 0.001) but negatively associated
with presence of physical illness (p = 0.004), older patient age (p = 0.04), and
GPs length in practice (p = 0.05). One GP felt their suicide case was
preventable. The low rate of risk assessment and limited knowledge of patient
lifestyle point to the need for active engagement of GPs in future suicide
prevention strategies and should influence the content of training programs in
primary care.
PMID- 10680285
TI - The cost of hospital care in the year before and after parasuicide.
AB - This study, based in Ireland in the Limerick centre of the WHO/EURO Multicentre
Study of Parasuicide, tests the hypothesis that the uptake of hospital services
increases significantly following an act of parasuicide. To investigate this, the
costs of hospital attendance in the year before and in the year after an act of
parasuicide are measured and compared. The sample is comprised of the first 100
individuals who attended an acute general hospital following an act of
parasuicide after July 1, 1995. Using a computerized patient record system, every
hospital attendance is identified, for each individual, in the 12 months before
and after the parasuicide act. This includes every visit to the Emergency Room as
well as both general and psychiatric inpatient admissions and outpatient
attendances. There was a 50% increase in the uptake of hospital services--32% of
the sample attended hospital in the year before compared with 48% in the year
after. The total yearly costs for the 100 patients almost doubled from IR 53,652
Pounds (Euro 68,138) to IR 104,454 Pounds (Euro 132,657). Generalizing to the 539
individuals who engaged in parasuicide in the Limerick catchment area, total
costs increased from IR 289,184 Pounds (Euro 367,264) to IR 563,007 Pounds (Euro
715,019). This study is an initial step toward the more complex task of
estimating to what extent the increased uptake of hospital services is due to the
consequences of parasuicide and how much is due to other aspects of the patient's
health.
PMID- 10680286
TI - Suicidal behavior in the Ukraine, 1988-1998.
AB - This report studies the available data concerning suicide rates in the Ukraine
and points to the importance of appropriate monitoring of suicides and attempted
suicides. It illustrates the necessity of collecting this information and of
developing "The Ukrainian National Program on Suicide Prevention." Unfortunately,
suicide research and publications about suicide rates were prohibited in the
former Soviet Union, so some of the data about suicidal behavior in the Ukraine
is incomplete. We used the official suicide death statistics of the Ukraine from
the Center of Statistics (Ukrainian Ministry of Health) for the period 1988-1998.
The overall rate of suicide in the Ukraine is relatively high. Official
statistics in the Ukraine show that there were 29.6 suicides per 100,000
population in 1998. The frequency of completed suicide differs in the various
regions of the country, suicides being more frequent in the industrially
developed regions and in the rural areas of the country than in the cities. In
the western part of the Ukraine the frequency of suicide is relatively low (11.1
per 100,000). Between 1988 and 1997 the suicide rate increased by 57%. In 1998
the suicide rate for women was approximately five times lower than that for men.
PMID- 10680287
TI - Evolution of a disease.
PMID- 10680288
TI - Aid for International Medicine, Inc. (AIM). Our last ten years.
PMID- 10680289
TI - Eye problems in the polar regions.
PMID- 10680290
TI - Medical mission to Honduras. December 20, 1998-January 2, 1999.
AB - This is the story of a team of medical professionals who responded to an appeal
from Church World Services in New York to provide two weeks of primary care for
Honduran people in areas devastated by Hurricane Mitch. It was a remarkable
experience to see how a small team of changing physicians, nurses, and support
personnel could function effectively although they had not known each other, or
ever worked together before. Over a period of two weeks with two major holiday
weekends and an unusual amount of time spent in travel, the team in seven working
days provided primary care to about 500 patients ages 1 day to 82 years with
limited medical supplies and no laboratory resources. The patients resided in
rural villages, without electricity or running water, which could only be reached
over poor rural roads. Full credit should be given to the Honduran CCD which
provided support services for the dedicated, compassionate American volunteers,
and to the Honduran villagers who patiently waited, often in the rain, to be
seen. It is hoped that the medical services were as helpful to the recipients as
the experience was to the team participants. There is little doubt that long run
efforts of CCD and other non-governmental organizations (NGOs) are needed to
stimulate overall improvement in the standard of living in rural villages. Future
sustained development will take local leadership to stimulate interest in a
better future by spacing children so they can have improved education and
healthier living conditions.
PMID- 10680291
TI - Medical assistance to the Dominican Republic. By health professionals of the
Delaware Army National Guard.
PMID- 10680292
TI - The medical missions of Rafael Zaragoza, M.D.: from homeland to hometown.
PMID- 10680293
TI - A study of 45,X/46,XX mosaicism in Turner syndrome females: a novel primer pair
for the (CAG)n repeat within the androgen receptor gene.
AB - This paper describes the procedures developed for the determining of
diparental/uniparental origin of X chromosomes in mosaic Turner females
(karyotype 45,X/46,XX), and accounts for results of the analysis of chromosomal
material from 20 girls with Turner syndrome. An (CAG)n repeat within the androgen
receptor (AR) gene was selected as a genetic marker. A novel primer pair for
amplification of the (CAG)12-30 repeat was designed. These primers gave an
amplification product of 338 bp in length and were following (5'-->3'):
agttagggctgggaagggtc and cggctgtgaaggttgctgt. Nineteen of the subjects were
heterozygous for the selected marker. In 4 cases there were distinct signals from
three alleles. The only Turner female in the study who had been previously
ascribed a non-mosaic 45,X karyotype by using cytogenetic techniques, proved to
be a cryptic mosaic, displaying two alleles of the genetic marker in the more
sensitive molecular assay. These results suggest that in most cases 45,X/46,XX
mosaicism in Turner females arises through loss of one of the X chromosomes in
some cell lines in originally 46,XX conceptuses, rather than through mitotic non
disjunction during early embryogenesis in originally 45,X conceptuses. A high
sensitivity of the modified assay based on PCR-amplification of the (CAG)n repeat
within AR gene proves its usefulness as a tool for studying mosaicism in Turner
syndrome.
PMID- 10680294
TI - Temporal and spatial variation of inversion polymorphism in two natural
populations of Drosophila buzzatii.
AB - The inversion polymorphism of the cactophilic fly Drosophila buzzatii was studied
in two natural populations. We assessed the temporal changes and microspatial
population structure. We observed a significant increase in the frequency of
arrangement 2J at the expense of 2ST in both populations. These gene arrangements
appear to affect the life-history of flies differently. Environmental
heterogeneity explains the karyotype coexistence in nature. The analysis of
population structure showed that differentiation of inversion frequencies among
individual breeding sites, the rotting clacodes of Opuntia vulgaris, was highly
significant. The karyotypic frequencies did not depart significantly from Hardy
Weinberg expectations, neither in individual rots nor in the total population.
These results suggest that the observed population structure can be easily
accounted by random genetic drift.
PMID- 10680295
TI - Development of PCR-based markers for thermosensitive genetic male sterility gene
tms3(t) in rice (Oryza sativa L.).
AB - Development of simple and reliable PCR-based markers is an important component of
marker-aided selection (MAS) activities for agronomically important genes in rice
breeding. In order to develop PCR-based markers for a rice thermosensitive
genetic male sterility gene tms3(t), located on chromosome 6, the nucleotide
sequences of four linked RAPD markers OPF18(2600), OPAC3(640), OPB19(750) and
OPM7(550) were used to design and synthesize several pairs of specific primers
for PCR amplification of the genomic DNA of both the parents IR32364TGMS
(sterile) and IR68 (fertile), involved in mapping this gene. For the RAPD marker
OPF 18(2600), two pairs of specific primer pair combination from different
positions of the sequence resulted in generation of two codominant STS (Sequence
Tagged Sites) markers. In case of markers OPAC3(640), OPB19(750) and OPAA7(550)
the first two could generate dominant polymorphism, while the last one could not
be successful in PCR amplification. Both the codominant STSs with primer
combinations F18F/F18RM and F18FM/F18RM were found to be tightly linked to the
tms3(t) gene with a genetic distance of 2.7 cM. The sizes of the different
alleles in case of F18F/F18RM, F18FM/F18RM combinations were 2300 bp, 1050 bp,
and 1900 bp, 1000 bp respectively. The efficiency of marker-assisted selection
for this trait was estimated as 84.6%. Polymorphism survey of 12 elite rice
lines, indicated that these PCR-based markers for tms3(t) can now be used in
selecting TGMS plants at seeding stage in the segregating populations in
environment independent of controlled temperature regime.
PMID- 10680296
TI - Increased sister chromatid exchange in the peripheral blood lymphocytes of young
women who smoke cigarettes.
AB - Rates of sister chromatid exchange in dividing human peripheral blood lymphocytes
were determined and compared between smoking and non smoking young women between
the ages of 16 and 25. Chromosomes block-stained with Giemsa were also examined
for chromosome aberrations. A striking difference in the frequency of sister
chromatid exchange was found between young women who smoked and those who did
not. Smokers scored a significantly higher, F(1) = 15.99, p = 0.0015, rate of
sister chromatid exchange than non smokers. Smokers scored a higher mean of SCEs
per cell (12.771, SD 3.53) than non smokers (9.712, SD 2.53). Smokers also scored
a higher range of SCEs (4 to 28) as opposed to non smokers (4 to 17). No
statistical difference was found between smokers and non smokers for the
frequency of chromosome aberrations. The significantly higher frequency of
exchange in young smoking women may indicate that initial damage to the DNA in
many of these women has probably already occurred, thus causing an increased risk
of developing cancer later in life.
PMID- 10680297
TI - Expression of the heat-shock protein HSP70 in Drosophila buzzatii lines selected
for thermal resistance.
AB - The level of HSP70 expression induced by a non-lethal high temperature was
examined in lines selected for increased thermal resistance and in corresponding
control lines of Drosophila buzzatii, in order to test if selection for high
temperature resistance leads to an increased level of HSP70 expression. The lines
used were selected for up to 64 generations either as adults or through all
larval stages. In adult selection lines, hard selection was implemented every
second generation after mild heat hardening. In larval selection lines, larvae
were exposed each generation to laboratory "natural" selection. Generally lines
selected as adults showed a higher HSP70 expression than did controls, both in
third instar larvae and in adults. A strong negative response to selection of
HSP70 expression was found in all lines that were selected at cycling
temperatures during larval development. The results suggests that a trade off
between heat resistance in form of HSP70 expression and fecundity/fertility are
responsible for the level of HSP70 expression. The effect of the different
methods of selection on HSP70 expression suggests that heat resistance
constitutes more than one trait.
PMID- 10680298
TI - An IgM monoclonal antibody to Japanese encephalitis virus recognizing a cross
reactive epitope on nuclear histones.
AB - An IgM class of monoclonal antibody (MAb) raised against 'envelope' (E)
glycoprotein of Japanese encephalitis (JE) virus, cross reacted with nuclear
histones, in addition to recognizing the viral antigen present in the cytoplasm
of infected cells by indirect fluorescent antibody (FA) technique. The
experiments on histone depletion by the acid treatment of uninfected PS (porcine
kidney) cells, revealed the loss of nuclear immunofluorescence (IF) which was
regained after the reconstitution of acid treated cells with histones, prior-to
reacting with MAb NHA-2. The IgM MAb recognized specifically the viral antigens
expressed on the surface of JE virus infected PS cells by a modified indirect FA.
The adsorption of MAb NHA-2 with calf thymus histones (type II-AS) showed a
comparative higher drop in the reactivity to JE virus (54.2% reduction) as
compared to that against uncomplexed histones (33.3%) by ELISA, thus indicating a
higher MAb affinity to the former. In contrast, the adsorption of MAb with
chicken RBC nuclei resulted in comparatively more reduction in the reactivity to
the uncomplexed histones (52.4% reduction) as against JE virus (37.5%),
suggesting that DNA plays some role in modifying and presenting these epitopes.
The cross-linkage of epitopes by glutaraldehyde treatment of JE virus antigen and
histones showed a 2-fold and higher rise in the MAb reactivity as against those
with unfixed or methanol fixed antigens (no cross-linkage), suggesting that the
epitope is conformation dependent. Thus, histones seem to share a partial
conformational homology with 'E' glycoprotein of JE virus and immune reaction
with histones might lead to an autoimmune disorder.
PMID- 10680299
TI - Cytotoxicity of non O1, non O139 Vibrios isolated from fresh water bodies in
Vellore, south India.
AB - The samples of plankton, soil sediment and water from a pond, a lake and a moat
respectively in and around Vellore were studied for environmental vibrios.
Vibrios were isolated from all these specimens after enrichment in alkaline
peptone water and subculture on selective media. Non O1, non O139 Vibrio
cholerae, Aeromonas spp. and Plesiomonas spp. were isolated. There were no
isolates of V. cholerae serogroup O1 and O139. Representative strains of non O1
and non O139 V. cholerae from environmental sources were tested for toxin
production in Chinese hamster ovary (CHO) and Vero cell monolayer in microtitre
plates. Thirty-three (91.7%) of the 36 strains tested demonstrated cytopathic
effect (CPE) in both cell lines indicating their toxigenicity. PCR done on
representative strains of non O1 and non O139 V. cholerae showed that none of the
strains were positive for ctx A, tcp A-E and tcp C genes. These results indicate
that these non agglutinating environmental vibrios produced cytotoxins other than
the cholera toxin.
PMID- 10680300
TI - Biotyping of Acinetobacter species isolated from clinical samples.
AB - We used the biotyping scheme using carbohydrate substrate utilization test with
14 carbon sources to speciate Acinetobacter isolates from blood and cerebrospinal
fluid cultures of patients admitted to the postoperative neurosurgery ICU during
January to November 1996. Sixty one patients culture positive for Acinetobacter
sp. from blood or cerebrospinal fluid were followed up prospectively. Among these
patients, 40 patients had clinically diagnosed infections like bacteriemia or
meningitis while in 21 patients the isolation was regarded as contaminants. A.
baumanniii was the most common isolate associated with clinical infections while
A. lwoffii was more likely to be an environmental contaminant.
PMID- 10680301
TI - Changing trend in susceptibility pattern of Streptococcus pneumoniae to
penicillin in India.
AB - Prior to 1995 all strains of Streptococcus pneumoniae isolated at a tertiary care
hospital in south India were uniformly susceptible to penicillin. However, since
late 1995 strains of S. pneumoniae with intermediate resistance to penicillin
have been observed. Altogether there were 25 such isolates, 9 from invasive (5
from CSF as well as blood, 1 from pleural fluid and 3 from CSF alone) and 16 from
noninvasive sites (6 from throat, 6 from sputum, 3 from eye and 1 from ear)
respectively, thus 4.6 per cent of S. pneumoniae showed intermediate resistance
of a total of 535 strains studied so far. The minimum inhibitory concentration
(MIC) values of penicillin, erythromycin, chloramphenicol and cefotaxime were
determined by agar dilution method and for confirmation, E test was carried out
for penicillin alone. The MIC range obtained for penicillin was between 0.125-1.0
microgram/ml. Kirby-Bauer disc diffusion method was adopted for testing of
erythromycin, chloramphenicol, co-trimoxazole, cefotaxime, tetracycline and
vancomycin. We observed that none of the strains with intermediate resistance to
penicillin were multidrug resistant. These strains belonged predominantly to
serotype 14 (n = 10), 7B (n = 9), 19A (n = 3), 7F (n = 2) and 23F (n = 1).
Clonality was not observed in the 5 representative strains subjected to Box A
finger printing method.
PMID- 10680302
TI - Yeast colonisation & fungaemia in preterm neonates in a tertiary care centre.
AB - Seventy consecutive preterm neonates who stayed in the hospital for more than
seven days between March and October 1996, were studied for colonisation at oral,
umbilical, groin, and rectal areas and for fungaemia. Overall, 71.4 per cent of
the neonates were colonised and colonisation occurred within 24 h in 38 per cent
preterm neonates. Neonates weighing less than 1500 g were colonised more
frequently at more than one site and had higher load of yeast. Candida albicans
(19%), Pichia (Hansenula) anomala (17.5%), C. tropicalis (13.2%), C. parapsilosis
(12.3%) and Trichosporon cutaneum (10.0%) were the predominant colonising yeasts.
Fungaemia was detected in 22.8 per cent of preterm neonates with predominance of
P. anomala fungaemia (62.5%). Prematurity, male sex, broad spectrum antibiotic
therapy, intubation and higher colonising rate were identified as significant
risk factors for development of fungaemia. Except one strain of C. tropicalis,
all yeast strains were sensitive to commonly used systemic antifungal agents.
Study highlights the importance of routine surveillance of yeast colonisation of
preterm neonates with identifying possible risk factors.
PMID- 10680303
TI - A comparison of esmolol & diltiazem for heart rate control during coronary
revascularisation on beating heart.
AB - This prospective study was done to compare the control of heart rate and
haemodynamics during coronary artery revascularisation without cardiopulmonary
bypass using either esmolol or diltiazem. Sixty adult patients with one or two
vessel coronary artery disease, were randomly divided into 2 equal groups. Group
A received a 500 micrograms/kg loading dose of esmolol followed by a 100
micrograms/kg/h infusion, for control of heart rate during surgical anastomosis
of the coronary vessel. While Group B received 0.15 mg/kg diltiazem as a loading
dose followed by a 5 mg/h infusion for heart rate control, during the
anastomosis. It was seen that heart rate control was better in Group A, 51.4 (+/-
1.3) beats/min, than in Group B, 69.6 (+/- 3.9) beats/min but the decrease in
heart rate was significant in both the groups at peak effect compared to
respective predrug values. Group A patients had unchanged systemic resistance and
pulmonary artery wedge pressure but mean pulmonary artery pressure and pulmonary
vascular resistance were significantly raised. Group B patients had decreased
systemic resistance, mean pulmonary artery pressure and pulmonary artery wedge
pressure, and reduced right ventricular stroke work index. We concluded that
although esmolol provided dramatically slower heart rates, during surgery, the
resulting elevations in mean pulmonary artery pressure and pulmonary vascular
resistance would require caution if used in patients with underlying right
ventricular dysfunction from ischaemia or infarction. Diltiazem by virtue of its
effects on systemic vascular resistance, cardiac output, and lowering of mean
arterial pressure may be a better choice in hypertensive patients.
PMID- 10680304
TI - Millennial editorial message.
PMID- 10680305
TI - Oxidative stress induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin: an application
of oxidative stress markers to cancer risk assessment of dioxins.
AB - Dioxins are known to be a class of highly toxic and persistent environmental
contaminants. Among them the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin
(TCDD) has been the most intensively studied, and it has been classified as a
human carcinogenic substance by the International Agency for Research on Cancer
(IARC). Although the mechanism of carcinogenesis by TCDD is unclear, it is now
considered to have act a cancer promoter. In this review, was discuss the ability
of TCDD to induce oxidative stress in vivo, the mechanism of the oxidative stress
induction, and how oxidative stress relates to the development of cancer. We then
discuss the advantages of measuring the level of oxidative stress in people
exposed to dioxins in epidemiological studies for cancer risk assessment. We also
discuss several methods of measuring the level of oxidative stress in humans.
PMID- 10680306
TI - Characteristics of coronary heart disease in Japanese taxi drivers as determined
by coronary angiographic analyses.
AB - Several epidemiological studies have shown that the prevalence of ischemic heart
disease is higher in occupational drivers than in people with other occupations.
Although occupation categories can be surrogate measures for coronary risk
factors, the relationships between taxi driving and severity of coronary heart
disease (CHD) has not been investigated. Even more important, the contribution of
risk factors to the severity of CHD in taxi drivers remains unclear. Our study
tested the hypothesis that taxi driving could be associated with the severity of
CHD. We also examined the relation between this occupation and risk factors and
social lifestyle. We analyzed the coronary angiograms of 57 consecutive male taxi
driver patients and compared them with those of 215 age-adjusted male non-taxi
driver patients. The number of diseased vessels and risk factors were compared
between two groups. The prevalence of myocardial infarction and multi-vessel
disease was higher in the taxi-driver patients than in the non-taxi-driver
patients. The taxi-driver patients had higher prevalence of body mass index
(BMI), diabetes, and smoking, higher levels of low-density lipoprotein
cholesterol (LDL-C), and lower levels of apolipoprotein AI (ApoAI). Multiple
logistic regression analysis showed that multi-vessel disease was associated with
BMI and diabetes mellitus in taxi-driver patients. The taxi-driver patients were
characterized by more extensive coronary atherosclerosis associated with higher
prevalence of diabetes mellitus and obesity. These characteristics may be
explained by in part their working environment.
PMID- 10680307
TI - Laboratory evaluation of welder's exposure and efficiency of air duct ventilation
for welding work in a confined space.
AB - CO2 arc welding in a confined space was simulated in a laboratory by manipulating
a welding robot which worked in a small chamber to experimentally evaluate the
welder's exposure to welding fumes, ozone and carbon monoxide (CO). The effects
of the welding arc on the air temperature rise and oxygen (O2) concentration in
the chamber were also investigated. The measuring points for these items were
located in the presumed breathing zone of a welder in a confined space. The time
averaged concentrations of welding fumes, ozone and CO during the arcing time
were 83.55 mg/m3, 0.203 ppm and 0.006%, respectively, at a welding current of
120A-200A. These results suggest serious exposure of a welder who operates in a
confined space. Air temperature in the chamber rose remarkably due to the arc
heat and the increase in the welding current. No clear decrease in the O2
concentration in the chamber was recognized during this welding operation. A
model of air duct ventilation was constructed in the small chamber to investigate
the strategy of effective ventilation for hazardous welding contaminants in a
confined space. With this model we examined ventilation efficiency with a flow
rate of 1.08-1.80 m3/min (ventilation rate for 0.40-0.67 air exchanges per
minute) in the chamber, and proved that the exposure level was not drastically
reduced during arcing time by this air duct ventilation, but the residual
contaminants were rapidly exhausted after the welding operation.
PMID- 10680308
TI - Drafts in cold environments--the significance of air temperature and direction.
AB - This paper concerns the influence of air temperature and of the direction of
drafts on subjective and physiological responses. In three experimental series 58
healthy persons (50 men, 8 women, 20-29 yrs) were exposed to drafts in overall
446 experimental sessions. Drafts were applied either horizontally or vertically
with mean air velocities of 0.1 to 0.3 m/s and a turbulence intensity of 50%. Air
temperature was varied between 11 and 23 degrees C and metabolic rates between <
70 and 156 W/m2. These parameters were kept constant during the single one-hour
sessions. The subjects were dressed for thermal neutrality. Draft-induced
annoyance was registered every 5 minutes using a list of prescribed body parts
and skin temperature was measured at the forearm and at the neck. Subjective and
physiological responses were systematically related to air temperature. Draft
induced general annoyance, draft-induced local annoyance (neck, forearm) and the
drop of the corresponding skin temperature were inversely related to air
temperature. Concerning the direction horizontal drafts seem to cause somewhat
stronger reactions. The predictive model developed by Toftum underestimates the
percentage of persons annoyed. A modified version increases the predictive power
significantly.
PMID- 10680309
TI - Evaluation of workers' exposure to dust, ammonia and endotoxin in poultry
industries at the province of Isfahan, Iran.
AB - This study was conducted to assess various environmental exposure measurements
(total dust, ammonia and endotoxin) of poultry workers at the province of
Isfahan, Iran. The results show that the workers who worked in enclosed systems
of parent stock barns have the highest exposure to total and respirable dust:
21.3 +/- 3.2 and 4.6 +/- 0.9 mg/m3, respectively. In comparison with different
ages of chicken, the highest concentration of total and respirable dust were 5.4
+/- 0.7 and 3.3 +/- 0.7 mg/m3 in the 45th day. In the above mentioned situation,
the results of endotoxin concentrations were 20.6 +/- 1.1, 23.6 +/- 2.2, 21.3 +/-
1.2 and 26.8 +/- 1.8 ng/m3, respectively. Ammonia concentrations had the highest
rate in enclosed systems of laying hens in winter and the 45th day of chicken
age, measuring 33.2 +/- 5.2 and 20.2 +/- 3.0 mg/m3, respectively.
PMID- 10680310
TI - An electromyographic study of two different types of ballpoint pens-
investigation of a one hour writing operation.
AB - Recently there has been an increasing incidence of occupational cervicobrachial
disorders (OCD) and writer's cramp in office workers using ballpoint pens in
writing operations. For the sake of workers who use ballpoint pens, it is
essential to prevent such health hazards. It has been observed that a strong
gripping pressure on the ballpoint pen significantly contributes to the
development of these conditions. The present authors have been developing a new
ballpoint pen by altering the grip area in such a way as to reduce the gripping
pressure, and thus prevent OCD. The purpose of this study is to compare our
ballpoint pen (new pen) with a conventional ballpoint pen (conventional pen) for
the load that they exert on the upper limb during one hour of continuous writing.
Electromyograms (EMG) and upper limb pain scores are used as indicators. The
conventional pen used was selected from commercially available ballpoint pens
widely used in offices. The grip area is cylindrical with an 8.3 mm diameter. It
is manufactured of hard plastic, which can make it feel rigid and slippery to the
user. The new pen has a cylindrical grip area that flares out at the bottom, near
the pen-tip, and has a diameter ranging from 11.9-13.6 mm. In addition, the grip
is constructed of a 2 to 3 mm-thick silicon rubber sleeve that is softer and less
slippery in comparison with the conventional pen. Twelve students (5 males and 7
females) without any preexisting cervicobrachial disorders were asked to
transcribe an English text for one hour, alternately using the two kinds of pens.
The EMG of the flexor pollicis brevis was measured and recorded every second,
while subjective pain scores were recorded every five minutes for the thumb,
forefinger, middle finger, thenar, forearm extensor (forearm) and shoulder. The
EMG of the flexor pollicis brevis and the pain scores for the thumb, forefinger,
middle finger, forearm and shoulder were significantly lower for the new pen than
for the conventional pen. These results suggest that after an hour of continuous
writing, the new pen reduces the muscle load on the upper limb, and therefore
mitigates fatigue in this area.
PMID- 10680311
TI - Blood lead levels in copper smelter workers in Japan.
AB - Lead exposure of workers in a Japanese copper smelter was assessed by determining
lead levels in blood, air and flue cinder at the copper smelting processes. All
the samples were analyzed for lead by atomic absorption spectrometry. Mean lead
levels of air were highest at the anode department followed by the converter,
smelter and blend departments. The mean level of blood lead of the workers in the
anode department was also the highest among the four smelting departments. The
mean blood lead levels of the workers in each department were positively
correlated with their air lead levels (r = 0.99, p < 0.01). This study indicates
therefore that workers in copper smelters have been exposed to lead in their
workplace. Though this finding has already been reported in preceding studies,
the Ordinance on Prevention of Lead Poisoning in Japan has not included copper
smelter into its target job categories if their lead concentration in the raw
material is less than 3%. The limitation of the present Ordinance which defines
the targets by the types of job and not by the actual exposure, is discussed.
PMID- 10680312
TI - Sleep problems in white-collar male workers in an electric equipment
manufacturing company in Japan.
AB - In order to clarify poor sleep habits and prevalence in sleep problems
(disturbances) of healthy male white-collar workers and the relationship of these
to age and job type, a total of 1,161 Japanese employees of an electric equipment
manufacturing company (aged 23 to 59, mean 37 years) were surveyed by means of a
mailed questionnaire. The workers were asked about eleven sleep habits. They were
also divided into four groups according to age and job type: 23-29 (n = 226), 30
39 (n = 597), 40-49 (n = 225) and 50-59 (n = 113); managerial (n = 209),
professional (n = 336), technical (n = 475) and clerical (n = 134). In this
study, the sleep problems were defined as who had at least one of the following
four poor sleep habits: 1) taking more than 30 minutes to fall asleep, 2)
awakening during sleep (ADS) almost every day, 3) early morning awakening (EMA)
almost every day, and 4) excessive daytime sleepiness (EDS) at work almost every
day. Analyses showed that sleep problems were present in 26.0% of workers; the
problems were most serious among workers aged 50 years and more (36.0%) which may
be due to a significant increase in the prevalence rate of EMA. The results
revealed that sleep problems are common in male white-collar daytime workers. The
findings also suggest a need for increased attention to sleep problems in older
workers and younger ones with EDS at work.
PMID- 10680313
TI - Laboratory measurement of hazardous fumes and gases at a point corresponding to
breathing zone of welder during a CO2 arc welding.
AB - Concentrations of fumes, ozone (O3), carbon monoxide (CO), nitric oxide (NO),
manganese (Mn) and total and hexavalent chromium (Cr) as well as size
distribution of fumes were measured at a point corresponding to the welder's
breathing zone during CO2-arc welding, using a welding robot and three kinds of
wires. Concentrations of fumes, O3, CO, Mn and total-Cr were found to exceed
their corresponding occupational exposure limit (OEL) values, while the
concentrations of NO and Cr(VI) were below those OEL levels. Airborne
concentration of Mn exceeded its OEL value, and the Mn content was 8 times higher
in welding fumes than in the wire. Using an additive equation of OEL and exposure
concentration of each hazardous component, health risk in welders with combined
exposure to welding fumes and gases was assessed as 18.6 to 46.0 times of OEL,
which exceeded the unity. This finding suggests that effective protection of
welders from the exposure can be attained by use of the supplied-air respirator
or combined use of a dust respirator and a local exhaust system.
PMID- 10680314
TI - Changes in cold-induced vasodilatation, pain and cold sensation in fingers caused
by repeated finger cooling in a cool environment.
AB - To examine how repeated cooling of fingers with a rest pause schedule at work
affects cold-induced vasodilatation (CIVD), pain and cold sensation in fingers,
six healthy men aged 21 to 23 years immersed their left index fingers six times
in stirred water at 10 degrees C for 10 minutes. After each cold-water immersion
of the fingers, 5-minute rest pause was taken to observe the recovery process of
the indicators. This cold-water immersion/rest pause test was carried out in a
range of three ambient temperature conditions: 30 degrees C (warm), 25 degrees C
(thermoneutral), and 20 degrees C (cool) as experienced in daily life. At the
ambient temperatures of 30 degrees C and 25 degrees C, marked CIVD response
occurred and the CIVD reactivity did not significantly change upon repetition of
cold-water immersion. The lowered finger skin temperature also tended to recover
quickly to the pre-immersion level during each post-immersion rest period. At the
ambient temperature of 20 degrees C, however, the CIVD response weakened
continuously upon repetition of immersion and almost disappeared during the final
immersion. The recovery of finger skin temperature during each post-immersion
rest was gradually delayed upon repetition of immersion. At every ambient
temperature, finger pain and cold sensation induced by each cold-water immersion
significantly decreased upon repetition of immersion and completely disappeared
during each post-immersion rest period. Oral temperature during the experiment
showed no significant change at the ambient temperatures of 25 degrees C and 30
degrees C, but it decreased significantly at the ambient temperature of 20
degrees C. These results suggest that in a cool work environment where the body
core temperature is liable to decrease, repeated finger cooling may weaken CIVD
reactivity and delay the recovery of finger temperature during post-immersion
rest periods. In such lower ambient temperature work conditions, subjective
judgements such as the decrease in finger pain and cold sensation during repeated
finger cooling and the absence of them during post-immersion rest may not be
reliable indicators for monitoring the risk of progressive tissue cooling and
frostbite formation.
PMID- 10680315
TI - Individual metal responsive elements of the human metallothionein-IIA gene
independently mediate responses to various heavy metal signals.
AB - Metallothioneins (MTs) are small metal-binding proteins that have a role in the
defense against heavy metals. Mammalian MT genes are transcriptionally activated
by metals such as Cd and Zn through multiple copies of the metal responsive
element (MRE) present in the 5'-flanking region. To examine whether each MRE in a
single promoter has a distinct role, we characterized seven MREs located upstream
of the human MT-IIA gene. By transient transfection experiments using MRE-driven
reporter gene constructs, individual MREs were assayed for the activity to
mediate transcription in response to several heavy metal species. Four MREs
including MREs a, b, e and g independently mediated reporter gene expression in
response to Zn, Cd and Hg, while other MREs were not responsive to any of these
metals. These results suggest that the multiplicity of MRE contributes to
enhancing its activity, rather than providing functional diversity.
PMID- 10680316
TI - Selective determination method for vanadium (V) and vanadium (IV) controlling the
pH of media for a solid-liquid extraction column.
AB - Solid-liquid extraction separation based on a speciation method was studied for
selective determination of vanadium (IV) and vanadium (V). Both V (IV) and V (V)
cations transform to oxo-acid anion along with pH changes in the solution. The pH
values for the transition points are different from each other and the difference
was utilized in the separation. In the first step, particulate samples are
dissolved by strong acids such as 1 M H2SO4 or 85% H3PO4. The pH of the strong
acidic sample solutions of V (IV) and V (IV) are adjusted to the range between 3
and 4. In this condition, V (IV) is in the form of cation but V (V) is anion. The
pH adjusted solution is applied to an anion exchange column. The solution is
expected to contain V (IV) only. The trapped V (V) anion is eluted as VO2+ cation
by a pH 1 acid. The author and coworker have already developed an HPLC separation
method utilizing this separation concept. However, the HPLC method has some
limitations, mainly originated in physical and chemical weaknesses of the HPLC
column. In the present study, a firm solid-liquid column is adopted to replace
the feeble HPLC column as a separation device. And a simple and convenient pH
adjustment technique for making the sample solution is investigated at the same
time. With these improvements, the speciation method developed with strong acidic
solutions could determine the amount of V (IV) and V (V) in various environmental
and biological samples.
PMID- 10680317
TI - Relationship between blood lead level and urinary ALA level in workers exposed to
very low levels of lead.
AB - The relationship between blood lead (PbB) level and urinary delta-aminolevulinic
acid (ALAU) level was examined in a total of 3,636 lead-exposed workers in a
periodic medical examination in 1992, in accordance with the Ordinance on
Prevention of Lead Poisoning. The results were consistent with previously
reported results in that ALAU level was found to increase with an increase in PbB
level above 22.4 micrograms/dl (1.35 as a logarithmic value) and to rise markedly
above 35.5 micrograms/dl (1.55). On the contrary, the geometric means of ALAU
levels appeared to decrease with an increase in PbB levels within a range between
a logarithmic value of 0.15 (1.4 micrograms/dl) and 1.25 (17.8 micrograms/dl).
Because the earliest sign of the adverse health effects of lead is reported to
occur at a PbB level of of 20 micrograms/dl, the relationship between PbB level
and ALAU level was examined at PbB levels below 20 micrograms/dl. A regression
formula was obtained, Y (log ALAU (mg/l)) = -0.0570X (log PbB (microgram/dl) +
0.4099. This result indicates that ALAU level decreases with a concomitant
increase in PbB level lower than 20 micrograms/dl.
PMID- 10680318
TI - Effects of coffee consumption against the development of liver dysfunction: a 4
year follow-up study of middle-aged Japanese male office workers.
AB - The association of coffee consumption with the development of increased serum
aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) activities
over 4 years was studied in 1221 liver dysfunction-free (serum AST and ALT < or =
39 IU/l and no medical care for or no past history of liver disease) Japanese
male office workers aged 35 to 56 years. From the analysis using the Kaplan-Meier
method, the estimated incidence of serum AST and/or ALT > or = 40 IU/l, > or = 50
IU/l, and > or = 60 IU/l decreased with an increase in coffee consumption. From
the Cox proportional hazards model, coffee drinking was independently inversely
associated with the development of serum AST and/or ALT > or = 40 IU/l (p = 0.019
by test for tendency), > or = 50 IU/l (p = 0.002), and > or = 60 IU/l (p =
0.007), controlling for age, body mass index, alcohol intake, and cigarette
smoking. These results suggest that coffee may be protectively against the liver
dysfunction in middle-aged Japanese men.
PMID- 10680319
TI - On "A retrospective cohort study of male workers exposed to PVA fibers".
PMID- 10680320
TI - OSMA launches physicians' campaign for a healthier Oklahoma.
PMID- 10680321
TI - A cardiac patient with renal failure: a clinicopathologic correlation conference
from the University of Oklahoma College of Medicine.
PMID- 10680322
TI - Immunization rate comparison for Oklahoma Medicaid managed care population by age
two: 1995-1998.
AB - Processes of care are used as one measure for the quality of care rendered by
providers. One example is the immunization of children by the age of two. The
Oklahoma Health Care Authority, with the Oklahoma Foundation for Medical Quality,
has been tracking childhood immunization rates from 1995 through 1998. The rate
calculated included the medical record data and the Oklahoma Statewide
Immunization Information System (OSIIS) data set. The standards were based on
Advisory Committee on Immunization Practices recommendations and Quality
Assurance Reform Initiative standards. The rate of provision of documented
immunizations in the Medicaid managed care population under the age of two has
improved markedly from 1995 to 1998. The trend analysis suggests there might be
areas for continued improvement in the provision of immunization to individuals
in Oklahoma's Medicaid managed care population. Further, the OSIIS data is
critical for maintaining a uniform data set for immunization information.
PMID- 10680323
TI - Severe invasive group A beta-hemolytic streptococcus infection complicating
pharyngitis: a case report and discussion.
AB - Group A beta-hemolytic streptococcus (GABHS) has long been recognized as a deadly
pathogen with manifestations ranging from impetigo to necrotizing fasciitis.
Bacteremia from streptococcal pharyngitis is a rare complication. We report a
patient presenting with septic shock and diabetic ketoacidosis from streptococcal
pharyngitis. The pathophysiology, classification, and treatment of invasive group
A streptococcal infection is discussed.
PMID- 10680324
TI - The Internet for dentists.
PMID- 10680325
TI - Biopsychosocial solutions to TMD.
PMID- 10680326
TI - Probationary adhesive dentistry.
PMID- 10680327
TI - Glass ionomer restorations.
PMID- 10680328
TI - Considerations re: Antibiotic prophylaxis for dental patients at risk. Canadian
Dental Association.
PMID- 10680329
TI - The oral effects of smokeless tobacco.
AB - Smokeless tobacco use has increased rapidly in North America. This form of
tobacco use has many oral effects including leukoplakia, oral cancer, loss of
periodontal support (recession), and staining of teeth and composite
restorations. Systemic effects such as nicotine dependence, transient
hypertension and cardiovascular disease may also result from smokeless tobacco
use. This paper aims to guide dental practitioners in identifying oral lesions
that occur due to the use of smokeless tobacco and also offer guidelines on how
to counsel patients who express a desire to stop using smokeless tobacco
products.
PMID- 10680330
TI - [Familial adenomatous polyposis or Gardner syndrome--review of the literature and
presentation of 2 clinical cases].
AB - Gardner syndrome is a type of hereditary gastrointestinal polyposis. Dental
professionals should be aware that this syndrome can present as multiple impacted
teeth and sometimes as large osteomas in the head and neck area. Following a
brief review of literature, we present two cases of Gardner syndrome. One of
these cases was diagnosed after a dental examination. The high incidence of
malignant transformation of polyps into colorectal cancer indicates the
importance of early diagnosis and follow-up.
PMID- 10680331
TI - When professional burnout syndrome leads to dysthymia.
PMID- 10680332
TI - Effects of composite thickness on the shear bond strength to dentin.
AB - The manufacturers of some condensable posterior composites claim that their
products can be placed in bulk and light-cured in 5-mm-thick increments. This
study compared the shear bond strengths of three composite resins when bonded to
dentin in 2- and 5-mm-thick increments. Overall the bond strengths were adversely
affected by the composite thickness (p < 0.0001). The shear bond strength of each
composite tested was much lower when polymerized in a 5-mm increment than in a 2
mm increment of composite (p < or = 0.0005). The two condensable composites
tested had a lower bond strength than the conventional composite when polymerized
in a 5-mm bulk increment (p < or = 0.01).
PMID- 10680333
TI - Risk of recurrence of fetal chromosomal aberrations: analysis of trisomy 21,
trisomy 18, trisomy 13, and 45,X in 1,076 Japanese mothers.
AB - OBJECTIVE: To evaluate the risk of recurrence of fetal chromosomal aberrations in
women who had offspring with numeric chromosomal abnormalities. SUBJECTS AND
METHODS: This collaborative study consisted of 1,076 Japanese women with a
history of offspring with trisomy-21, -18, -13, or 45,X. Second-trimester
amniocenteses were performed, resulting in 1,248 fetal karyotypes that were
analyzed with reference to prior offspring karyotypes and maternal age. RESULTS:
Of the 842 women with trisomy-21 offspring, 10 conceived another such fetus. In 2
women with 3 or more such offspring, parental mosaicism of trisomy-21 was
suspected. The incidence of recurrence of trisomy-21 increased with age, and
significantly exceeded the incidence of trisomy-21 fetuses in the general
population. None of the 170 women with trisomy-18 offspring, and none of the 46
women with trisomy-13 offspring, had another such fetus. Of the 18 women with
45,X offspring, 1 with mos 45,X/46,XX had another such fetus. CONCLUSIONS: The
risk of recurrence of trisomy-21 is affected by maternal age and parental
germline mosaicism. The risk of recurrence of trisomy-18 or -13 appears to be
much lower than that of trisomy-21. Women who give birth to more than 1 offspring
with 45,X should be examined for mos 45,X/46,XX.
PMID- 10680334
TI - Microsatellite instability and hMSH2 gene mutation in a triple cancer (colon
cancer, endometrial cancer, ovarian cancer) patient in hereditary non-polyposis
colorectal cancer (HNPCC) kindred.
AB - A patient who had triple cancer (colon cancer, endometrial cancer, and ovarian
cancer) in HNPCC kindred is reported. Her family history revealed the occurrence
of colon cancer in her paternal aunt and in two cousins, fulfilling the minimum
HNPCC criteria. Microsatellite instability analysis revealed replication error
(RER)+ in all cancer lesions at 2 microsatellite loci (D1S191, BAT 40). SSCP
analysis suggested germline mutation in exon 2 of the hMSH2 gene. This case
showed the importance of complete family-history investigations to identify HNPCC
patients. In the near future, definitive diagnosis of HNPCC will be possible on
the basis of DNA studies.
PMID- 10680335
TI - Significance of multi-drug-resistant proteins in predicting chemotherapy response
and prognosis in epithelial ovarian cancer.
AB - OBJECTIVES: To clarify the expression of multi-drug-resistant (MDR) markers, GST
pi, c-Jun, P-glycoprotein (Pgp), and MDR-associated protein (MRP) in epithelial
ovarian cancer, and to determine whether their expression is predictive of
chemotherapy response and patient prognosis. METHODS: Specimens of 58 epithelial
ovarian cancer cases obtained at initial surgery were studied
immunohistochemically using antibodies. RESULTS: Overall positive rates in the 58
specimens were 58.6% for GST-pi, 44.8% for c-Jun, 27.6% for Pgp, and 22.4% for
MRP. The 5-year disease-free survival rate was 26.0% for patients with MRP
positive tumors and 75.2% for those with MRP-negative tumors. The prognosis for
those with MRP-positive tumors was significantly poorer (p < 0.05). Patients with
GST-pi-positive tumors had a significantly worse prognosis than those with GST-pi
negative tumors (51.9% vs 79.2%, p < 0.05). Multivariate analysis showed that
residual tumors 2 cm or larger and MRP expression were independent prognostic
factors for chemotherapy resistance. The relative risk of chemotherapy resistance
in a patient with a residual tumor 2 cm or larger, positive MRP, and positive GST
pi was 10.6 times greater than the risk in a patient without these factors.
CONCLUSION: MRP and GST-pi expression might be potential predictors of the
response to standard chemotherapy in epithelial ovarian cancer. Their expression
also might contribute to individualizing clinical trials of postoperative
chemotherapy.
PMID- 10680336
TI - Clinicopathological study of recurrent uterine cervical squamous-cell carcinoma.
AB - OBJECTIVE: To improve prognoses of patients with recurrent uterine cervical
squamous-cell carcinoma. PATIENTS AND METHODS: We clinicopathologically analyzed
464 patients with uterine cervical squamous-cell carcinoma (126 positive, 338
negative pelvic lymph-node metastasis) who were treated at the Saitama Cancer
Center from January 1, 1976 to December 31, 1991. RESULTS: The recurrence rates
of negative pelvic lymph-node metastasis patients were 14. 2% (39/274) in pT1b
and 32.8% (21/64) in pT2b. But for positive lymph-node metastasis patients the
rates were 39.0% (23/59) in pT1b and 58.2% (39/67) in pT2b. The interval to
recurrence was shorter in positive pelvic lymph-node patients than in negative
patients. The 5-year survival rates after relapse of negative lymph-node patients
with intrapelvic, extrapelvic, and both-sites recurrence were 53, 12, and 40%,
respectively. But among distant recurrent sites, lung metastasis in negative
lymph-node patients and lymphatic tract metastasis brought relatively fair
prognoses. CONCLUSIONS: Regular long-term checks are necessary and active
retreatments are recommended for patients with local recurrences, lung
metastasis, or lymphatic vessel metastatic lesions.
PMID- 10680337
TI - Recent trends in histological pattern of cervical carcinoma among three ethnic
groups in Malaysia.
AB - OBJECTIVE: To study the trend of different histological types of cervical
carcinoma among the 3 major ethnic groups in Malaysia. METHODS: All invasive
cervical carcinoma histologically diagnosed for the first time in 1991-1992 and
1996-1997 at the University Hospital, Kuala Lumpur (UHKL) were reviewed for the
following parameters; age, ethnic group, histological category. RESULTS: One
hundred and twenty-one and 145 cases were diagnosed in 1991-1992 and 1996-1997,
respectively. During both periods, squamous was followed by adeno and
adenosquamous carcinoma in frequency. Patients' mean ages ranged within the 4th
decade for all 3 major histological types. Ethnically, an overall predilection
for the Chinese was observed. While squamous carcinomas had declined among the
Chinese and Malays, adenocarcinomas were noted to increase. The converse was
observed among the Indians. CONCLUSIONS: Ethnically, cervical carcinoma showed a
predilection for Malaysians of Chinese descent. A decreasing incidence of
squamous with a worrying increasing trend of adenocarcinoma was observed, like in
other populations studied.
PMID- 10680338
TI - Brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP) levels
in normal pregnancy and preeclampsia.
AB - OBJECTIVE: Our purpose was to evaluate plasma levels of brain natriuretic peptide
(pBNP) and cyclic guanosine monophosphate (pcGMP) in preeclamptic patients and
controls. STUDY DESIGN: Blood samples were obtained from 35 patients with
preeclampsia and from the same women during the subsequent puerperal period. The
control group consisted of normotensive pregnant women, matched with the patients
for age, gestational age, and parity. The concentrations of pBNP and pcGMP were
determined by the RIA method. Statistical analysis was performed using the Mann
Whitney's U test. RESULTS: The pBNP level in the preeclampsia group was
significantly increased, to 7-fold that of the control group. The pcGMP level was
50% higher in the preeclampsia group than in the control group, but this was not
significant. Both the pBNP level and the pcGMP level in the puerperal period did
not significantly differ between the patients and the controls. CONCLUSION: The
pBNP concentrations increased in the preeclamptic women, and then these
compensations were normalized in the puerperal period.
PMID- 10680339
TI - Androgen-producing ovarian tumors: a clinicopathological study of 3 cases.
AB - The clinical course and pathological findings of 3 rare cases of androgen
producing ovarian tumors are presented. The ages of the 3 patients (Cases 1, 2,
and 3, respectively) were 43, 34, and 57 years, respectively. Their preoperative
serum testosterone levels were 506, 491, and 231 ng/dl, respectively. The
pathological diagnoses of Cases 1, 2, and 3 were a Sertoli-stromal cell tumor of
intermediate differentiation, a stromal tumor containing Leydig cells, and a
stromal tumor with minor sex cord elements, respectively. Patient 1 experienced a
recurrence, of a lesion at the vaginal stump 1 year and 2 months after the
initial surgery. The clinical courses of Cases 2 and 3 have been non
contributory.
PMID- 10680340
TI - Causes of stillbirth: an analysis of 77 cases.
AB - OBJECTIVE: To devise preventive measures for stillbirths, which account for more
than 70% of perinatal deaths in Japan. METHODS: We retrospectively reviewed the
medical records of 77 women with singleton pregnancies who gave birth to
stillborn infants at > or = 30 weeks between 1979 and 1996 at our hospital.
RESULTS: Major malformations were present in 21 (27%) of 77 infants, including 11
infants with anencephaly. Two infants (2.6%) were severely hydropic. Preeclampsia
preceded the stillbirth and might have been an indirect cause of stillbirth in 21
(39%) of 54 women whose infants had normal formations. The cause of stillbirth in
33 non-preeclamptic women was unclear in 15 (28%), abruptio placentae in 9, fetal
growth retardation in 3, the HELLP syndrome in 3, chorioamnionitis in 2, and cord
accident in 1. Abruptio placentae also occurred in 9 of 21 preeclamptic patients.
Thus, abruptio placentae was responsible for 18 (33%) of 54 stillborn infants
with a grossly normal appearance. An autopsy was performed on only 13 (24%) of 54
infants with grossly normal appearance and did not provide new information
relating to deaths. CONCLUSIONS: The causes of stillbirth were many and varied,
with a large proportion having no obvious cause, although autopsies were
underused. Increased monitoring for women with preeclampsia and early diagnosis
and prompt delivery for women with abruptio placentae might be helpful in
reducing the number of stillbirths.
PMID- 10680341
TI - Emergency obstetric hysterectomies for postpartum haemorrhage.
AB - OBJECTIVE: To review emergency obstetric hysterectomy in our unit, including the
indications for and morbidity associated with the procedure. DESIGN: A
retrospective cases analysis. SUBJECTS AND METHODS: Records of obstetric patients
who had undergone emergency hysterectomies in between 15 October 1993 and 31
December 1997 were reviewed retrospectively. RESULTS: There were 15,474
deliveries and 7 emergency obstetric hysterectomies. All cases had total
abdominal hysterectomy. The indications for hysterectomy were uterine atony and
placental disorders. There were one case of urinary bladder injury and 2 cases of
disseminated intravascular coagulopathy. There was no maternal mortality.
CONCLUSION: Emergency obstetric hysterectomy remains a potentially life-saving
procedure in unavoidable catastrophe. The 7 patients with life threatening
postpartum haemorrhage underwent hysterectomy after failure of conservative
measures. The morbidity is low and there was no mortality in this series.
PMID- 10680342
TI - The rapid biophysical profile for assessment of fetal well-being.
AB - OBJECTIVE: To determine the efficacy of the rapid biophysical profile (BPP), the
combination of amniotic fluid index (AFI) and sound-provoked fetal movement
(SPFM) detected by ultrasound, in predicting intrapartum fetal distress in high
risk pregnancies, compared with the nonstress test (NST). STUDY DESIGN: The
prospective study of diagnostic tests was conducted on a total of 1,069 high-risk
singleton pregnancies, undergoing antepartum assessment of both the standard NST
and the new rapid BPP, including AFI and SPFM detected by ultrasound. Intrapartum
continuous fetal heart rate (FHR) monitoring was performed in all of them. The
diagnostic indices of the NST and the rapid BPP was calculated in term of
predicting intrapartum fetal distress. RESULTS: The rapid BPP was a reliable
predictor of intrapartum fetal distress with higher sensitivity and specificity.
Its accuracy was better than that of the NST. The incidence of fetal compromise
among positive, equivocal, and negative tests of the rapid BPP are 78.57, 15.82
and 0.9%, respectively, whereas the incidence among nonreactive and reactive NST
are 31.63 and 2.52%, respectively. CONCLUSIONS: The rapid BPP is an effective
predictor of intrapartum fetal distress in high-risk pregnancies. It may suffice
as an inexpensive and less time-consuming method of evaluating antepartum fetal
well-being.
PMID- 10680343
TI - Delayed-type hypersensitivity reaction to human menopausal gonadotrophin.
PMID- 10680344
TI - Comparing lifetime emissions of natural gas and conventional fuel vehicles: an
application of the generalized ANCOVA model.
AB - New regulations and incentives are encouraging the use of clean, alternative fuel
vehicles (AFVs) in urban areas. These vehicles are seen as one option for
reducing air pollution from mobile sources. However, because of the limited
number of AFVs on the road, little is known about actual lifetime emissions
characteristics of in-use AFVs. This study describes the use of a generalized
analysis of covariance model to evaluate and compare the emissions from natural
gas vehicles with emissions from reformulated gasoline vehicles. The model
describes fleet-wide emissions deterioration, while also accounting for
individual vehicle variability within the fleet. This ability to measure
individual vehicle variability can then be used to provide realistic bounds for
the emissions deterioration in individual vehicles and the fleet as a whole. In
order to illustrate the use of the model, the carbon monoxide, oxides of nitrogen
(NOx), non-methane hydrocarbon (NMHC), and carbon dioxide emissions
characteristics of a fleet of dedicated natural gas Dodge Ram vans and a fleet of
dedicated reformulated gasoline Dodge Ram vans operating in the U.S. government
fleet are explored. The analysis demonstrates the utility of the statistical
method and suggests a potential for natural gas Dodge Ram vans to be generally
cleaner than their conventional fuel counterparts. However, in the case of NOx
and NHMCs, the analysis also suggests that these emissions benefits might be
reduced over the vehicle lifetime due to higher emissions deterioration rates for
natural gas vehicles. As this paper is aimed at illustrating the analysis of the
covariance model, the results reported herein should be considered within the
context of a more comprehensive study of these data before general conclusions
are possible. Generalization of these findings to other vehicle models and
alternative fuel technologies is not justified without further study.
PMID- 10680345
TI - An alternative to additional SO3 injection for fly ash conditioning.
AB - Small concentrations, approximately 2-10 parts per million (ppm), of injected
sulfur trioxide (SO3) have improved particulate collection efficiencies of
electrostatic precipitators burning lower-sulfur coal. However, the addition of
extra SO3 not only incurs costs but also presents negative environmental effects.
This work explored a method that could be applied to existing coal-fired power
plants to convert the sulfur dioxide (SO2) already present in the flue gas to
sufficient levels of SO3 for fly ash conditioning as an alternative to adding SO3
by burning elemental sulfur. During this research, a pre-mixed natural gas flame
was used to promote the conversion of SO2 to SO3 in a drop-tube furnace with
average non-flame, free stream gas temperatures of 450 and 1000 K. SO3
concentrations measured by wet chemistry and confirmed using elemental balances
of other sulfur species measured by gas chromatography revealed that as much as
7% of SO2 was homogeneously transformed to SO3. The results also showed that at
low temperatures, the rate at which SO3 is converted back to SO2 decreased, thus
extending the time period during which SO3 concentrations would be sufficient for
ash conditioning. An additional benefit of this technique is speculated to result
from increased flue gas humidity.
PMID- 10680346
TI - Distance-weighted traffic density in proximity to a home is a risk factor for
leukemia and other childhood cancers.
AB - Occupational exposure to elevated concentrations of benzene is a known cause of
leukemia in adults. Concentrations of benzene from motor vehicle exhaust could be
elevated along highly trafficked streets. Several studies have reported
significant associations between proximity to highly trafficked streets and the
occurrence of childhood cancers and childhood leukemia. These associations may be
due to chronic exposure to benzene or other carcinogenic components of vehicle
exhaust from these nearby streets or to some other factor (e.g., noise, increased
light exposure, or some unaccounted--for socioeconomic variable). We used data
for homes studied in an earlier childhood cancer study conducted in Denver, CO,
in the 1980s. No air pollution measurements were made in the original study. We
identified the highest trafficked street near each study home and obtained the
traffic density in 1979 and 1990. Traffic density was weighted for the distance
from the street to the home using 3 different widths of Gaussian curves to
approximate the decay of the emissions into the surrounding neighborhoods. The
associations between the 750-ft-wide distance-weighted traffic density metrics
and all childhood cancers and childhood leukemia are strongest in the highest
traffic density category (> or = 20,000 vehicles per day [VPD]). The odds ratio
is 5.90 (95% confidence interval [CI] 1.69-20.56) for all cancers and 8.28 (95%
CI 2.09-32.80) for leukemia. The results are suggestive of an association between
proximal high traffic streets with traffic counts > or = 20,000 VPD and childhood
cancer, including leukemia.
PMID- 10680347
TI - Determination of PM10 emission rates from street sweepers.
AB - The use of street sweepers to clean paved roads, particularly after high-wind
events, has been proposed as a PM10 control method. Using an artificial tunnel,
the emission rates for several street sweepers were quantified under actual
operating conditions. The tunnel was a tent enclosure, 6.1 x 4.3 x 73 m, open on
both ends. PM10 concentrations were measured at the inlet and outlet while a
sweeper removed sand deposited along the length. Measurements were made using a
specialized low-volume filter sampler and an integrating nephelometer. The volume
of air passing through the tunnel was measured by releasing an inert tracer,
sulfur hexafluoride, at the inlet and measuring its concentration at the outlet.
A large difference in emission rates between vacuum-type sweepers was observed,
with rates varying from 5 to 100 mg m-1 swept. For the cleanest sweepers, the
background rates (collected by sweeping clean pavement) were about half of the
total PM10 emission rate. These background emission rates likely were from diesel
exhaust; background rates for the single gasoline-powered sweeper were below
detection. Particle light scattering data confirmed the filter collection
results. The artificial tunnel approach would be useful in measuring total
emissions from other mobile and stationary sources.
PMID- 10680348
TI - Contribution of liquefied petroleum gas to air pollution in the metropolitan area
of Mexico City.
AB - An estimation of hydrocarbon emissions caused by the consumption of liquefied
petroleum gas (LPG) in the Metropolitan Area of Mexico City (MAMC) is presented.
On the basis of experimental measurements at all points of handling, during the
distribution process, and during the consumption of LPG in industrial devices and
domestic appliances, an estimated 76,414 tons/year are released to the air. The
most important contribution is found during the domestic consumption of LPG
(70%); this makes the control initiatives available to the consumer. By
developing a control program of LPG losses, a 77% reduction in emission is
expected in a 5-yr period. The calculated amounts of LPG emissions when
correlated with the consumption of LPG, combined with information from air
samples from the MAMC, do not point to LPG emissions as the most important factor
contributing to tropospheric ozone in the air in Mexico City.
PMID- 10680349
TI - Evaluation of total volatile organic compound emissions from adhesives based on
chamber tests.
AB - In 1997, Homeswest in western Australia and Murdoch University developed a
project to construct low-allergen houses (LAHs) in a newly developed suburb.
Before the construction of LAHs, all potential volatile organic compound (VOC)
emission materials used in LAHs are required to be measured to ensure that they
are low total VOC (TVOC) emission materials. This program was developed based on
this purpose. In recent times, the number of complaints about indoor air
pollution caused by VOCs has increased. A number of surveys of indoor VOCs have
indicated that many indoor materials contribute to indoor air pollution. Although
some studies have been conducted on the characteristics of VOC emissions from
adhesives, most of them were focused on VOC emissions from floor adhesives. Few
measurements of VOC emissions from adhesives used for wood, fabrics, and leather
are available. Furthermore, most research on VOC emissions from adhesives has
been done in countries with cool climates, where ventilation rates in the indoor
environment are lower than those in Mediterranean climates, due to energy
conservation. VOCs emitted from adhesives have not been sufficiently researched
to prepare an emission inventory to predict indoor air quality and to determine
both exposure levels for the Australian population and the most appropriate
strategies to reduce exposure. An environmental test chamber with controlled
temperature, relative humidity, and airflow rate was used to evaluate emissions
of TVOCs from three adhesives used frequently in Australia. The quantity of TVOC
emissions was measured by a gas chromatography/flame ionization detector. The
primary VOCs emitted from each adhesive were detected by gas chromatography/mass
spectrometry. The temporal change of TVOC concentrations emitted from each
adhesive was tested. A double-exponential equation was then developed to evaluate
the characteristics of TVOC emissions from these three adhesives. With this
double-exponential model, the physical processes of TVOC emissions can be
explained, and a variety of emission parameters can be calculated. These emission
parameters could be used to estimate real indoor TVOC concentrations in
Mediterranean climates.
PMID- 10680350
TI - In-stack condensible particulate matter measurements and issues.
AB - Particulate matter (PM) emitted from fossil fuel-fired units can be classified as
either filterable or condensible PM. Condensible PM typically is not measured
because federal and most state regulations do not require sources to do so. To
determine the magnitude of condensible PM emissions relative to filterable PM
emissions and to better understand condensible PM measurement issues, a review
and analysis of actual U.S. Environmental Protection Agency (EPA) Method 202 (for
in-stack condensible PM10) and EPA Method 201/201A (for in-stack filterable PM10)
results were conducted. Methods 202 and 201/201A results for several coal-burning
boilers showed that the condensible PM, on average, comprises approximately three
fourths (76%) of the total PM10 stack emissions. Methods 202 and 201/201A results
for oil- and natural gas-fired boilers showed that the condensible PM, on
average, comprises 50% of the total PM10 stack emissions. Methods 202 and
201/201A results for oil-, natural gas-, and kerosene-fired combustion turbines
showed that the condensible PM, on average, comprises 69% of the total PM10 stack
emissions. Based on these limited measurements, condensible PM can make a
significant contribution to total PM10 emissions for fossil fuel-fired units. A
positive bias (indicating more condensible PM than is actually emitted) may exist
in the measured data due to the conversion of dissolved sulfur dioxide to sulfate
compounds in the sampling procedure. In addition, these Method 202 results
confirm that condensible PM, on average, is composed mostly of inorganic matter,
regardless of the type of fuel burned.
PMID- 10680351
TI - Forecasts using neural network versus Box-Jenkins methodology for ambient air
quality monitoring data.
AB - This study explores ambient air quality forecasts using the conventional time
series approach and a neural network. Sulfur dioxide and ozone monitoring data
collected from two background stations and an industrial station are used.
Various learning methods and varied numbers of hidden layer processing units of
the neural network model are tested. Results obtained from the time-series and
neural network models are discussed and compared on the basis of their
performance for 1-step-ahead and 24-step-ahead forecasts. Although both models
perform well for 1-step-ahead prediction, some neural network results reveal a
slightly better forecast without manually adjusting model parameters, according
to the results. For a 24-step-ahead forecast, most neural network results are as
good as or superior to those of the time-series model. With the advantages of
self-learning, self-adaptation, and parallel processing, the neural network
approach is a promising technique for developing an automated short-term ambient
air quality forecast system.
PMID- 10680352
TI - Kinetics of catalytic oxidation of benzene, n-hexane, and emission gas from a
refinery oil/water separator over a chromium oxide catalyst.
AB - With the advances made in the past decade, catalytic incineration of volatile
organic compounds (VOCs) has become the technology of choice in a wide range of
pollution abatement strategies. In this study, a test was undertaken for the
catalytic incineration, over a chromium oxide (Cr2O3) catalyst, of n-hexane,
benzene, and an emission air/vapor mixture collected from an oil/water separator
of a refinery. Reactions were carried out by controlling the feed stream to
constant VOC concentrations and temperatures, in the ranges of 1300-14,700 mg/m3
and 240-400 degrees C, respectively. The destruction efficiency for each of the
three VOCs as a function of influent gas temperature and empty bed gas residence
time was obtained. Results indicate that n-hexane and the oil vapor with a
composition of straight- and branch-chain aliphatic hydrocarbons exhibited
similar catalytic incineration effects, while benzene required a higher
incineration temperature or longer gas retention time to achieve comparable
results. In the range of the VOC concentrations studied, at a given gas residence
time, increasing the operating temperature of the catalyst bed increased the
destruction efficiency. However, the much higher temperatures required for a
destruction efficiency of over 99% may be not cost-effective and are not
suggested. A first-order kinetics with respect to VOC concentration and an
Arrhenius temperature dependence of the kinetic constant appeared to be an
adequate representation for the catalytic oxidation of these volatile organics.
Activation energy and kinetic constants were estimated for each of the VOCs. Low
temperature destruction of the target volatile organics could be achieved by
using the Cr2O3 catalyst.
PMID- 10680353
TI - Methane emissions from domestic waste management facilities in Jordan-
applicability of IPCC methodology.
AB - In this paper, methane emissions from municipal wastewater treatment plants and
municipal solid waste (MSW) landfills in Jordan for 1994 have been estimated
using the methodology developed by the Intergovernmental Panel on Climate Change
(IPCC). For this purpose, the 14 domestic wastewater treatment plants in the
country were surveyed. Generation rates and characterization of MSW components as
well as dumping and landfilling practices were surveyed in order to estimate 1994
CH4 emissions from these sites. Locally available waste statistics were used in
cases where those of the IPCC guidelines were not representative of Jordan's
statistics. Methane emissions from domestic wastewater in Jordan were estimated
at 4.66 gigagrams (Gg). Total 1994 CH4 emissions from MSW management facilities
in Jordan are estimated at 371.76 Gg--351.12 Gg (94.45%) from sanitary landfills,
19.83 Gg (5.33%) from MSW open dumps, and 0.81 Gg (0.22%) from raw sewage-water
dumping ponds. Uncertainties associated with these estimations are presented.
PMID- 10680354
TI - An intelligent emissions controller for fuel lean gas reburn in coal-fired power
plants.
AB - The application of artificial intelligence techniques for performance
optimization of the fuel lean gas reburn (FLGR) system is investigated. A
multilayer, feedforward artificial neural network is applied to model static
nonlinear relationships between the distribution of injected natural gas into the
upper region of the furnace of a coal-fired boiler and the corresponding oxides
of nitrogen (NOx) emissions exiting the furnace. Based on this model, optimal
distributions of injected gas are determined such that the largest NOx reduction
is achieved for each value of total injected gas. This optimization is
accomplished through the development of a new optimization method based on neural
networks. This new optimal control algorithm, which can be used as an alternative
generic tool for solving multidimensional nonlinear constrained optimization
problems, is described and its results are successfully validated against an off
the-shelf tool for solving mathematical programming problems. Encouraging results
obtained using plant data from one of Commonwealth Edison's coal-fired electric
power plants demonstrate the feasibility of the overall approach. Preliminary
results show that the use of this intelligent controller will also enable the
determination of the most cost-effective operating conditions of the FLGR system
by considering, along with the optimal distribution of the injected gas, the cost
differential between natural gas and coal and the open-market price of NOx
emission credits. Further study, however, is necessary, including the
construction of a more comprehensive database, needed to develop high-fidelity
process models and to add carbon monoxide (CO) emissions to the model of the gas
reburn system.
PMID- 10680355
TI - A new screening measure to identify potential carbon monoxide hotspots.
AB - To demonstrate conformity of transportation projects to National Ambient Air
Quality Standards in accordance with State Implementation Plans, the U.S.
Environmental Protection Agency (EPA) uses intersection level of service (LOS) as
one of its major criteria for screening for potential carbon monoxide (CO)
hotspots. Although intersection LOS is a measure of traffic volume, signal
timing, and related congestion and delay, the assigned level reflects only the
computed averaged stopped delay (ASD) per vehicle at the intersection. Thus,
intersections can often operate at the same LOS but produce vastly different
levels of predicted CO concentrations. For example, a two-lane approach operating
at LOS D will produce very different levels of CO than a five-lane approach also
operating at LOS D. This study explores the effectiveness of the LOS D criterion
as a screen for identifying potential CO hotspots. The study results indicate
that LOS is a poor predictor of potential CO hotspots when compared to results
generated with the EPA-recommended micro-scale model CAL3QHCr. To more
consistently screen out those intersections that will not be identified as CO
hotspots using the micro-scale models, a new criterion, equivalent red-time
vehicles (ERTV), is introduced. The modeling results using ERTV suggest that it
is a more robust measure for identifying potential CO hotspots, and conversely,
screening out those intersections that are not likely to be identified as
hotspots using micro-scale simulation results.
PMID- 10680356
TI - Meteorological factors of ozone predictability at Houston, Texas.
AB - Several ozone modeling approaches were investigated to determine if uncertainties
in the meteorological data would be sufficiently large to limit the application
of physically realistic ozone (O3) forecast models. Three diagnostic schemes were
evaluated for the period of May through September 1997 for Houston, TX.
Correlations between measured daily maximum and model calculated O3 air
concentrations were found to be 0.70 using a linear regression model, 0.65 using
a non-advective box model, and 0.49 using a three-dimensional (3-D) transport and
dispersion model. Although the regression model had the highest correlation, it
showed substantial underestimates of the highest concentrations. The box model
results were the most similar to the regression model and did not show as much
underestimation. The more complex 3-D modeling approach yielded the worst
results, likely resulting from O3 maxima that were driven by local factors rather
than by the transport of pollutants from outside of the Houston domain. The
highest O3 concentrations at Houston were associated with light winds and
meandering trajectories. A comparison of the gridded meteorological data used by
the 3-D model to the observations showed that the wind direction and speed values
at Houston differed most on those days on which the O3 underestimations were the
greatest. These periods also tended to correspond with poor precipitation and
temperature estimates. It is concluded that better results are not just obtained
through additional modeling complexity, but there needs to be a comparable
increase in the accuracy of the meteorological data.
PMID- 10680357
TI - Pyrolysis kinetics and residue characteristics of petrochemical industrial
sludge.
AB - This study investigated the pyrolysis characteristics of sludge from wastewater
treatment plants in the petrochemical industry and focused on the pyrolysis
kinetics, elemental composition of residue, and volatile organic compounds (VOCs)
of exhaust gas. As pyrolysis temperature increased to 773 K, the increasing rate
of crude oil production tended to a stable condition. The result indicated that
the optimal temperature of crude oil and water mixed production was 773 K. When
pyrolysis temperature increased from 673 to 973 K, carbon, oxygen, nitrogen, and
hydrogen concentrations of residue decreased and the sulfur concentration of
residue increased. The concentrations of benzene, toluene,ethylbenzene, and
styrene increased by the increasing pyrolysis temperature. We found that the
reaction order of sludge pyrolysis was 2.5 and the activation energy of the
reaction was 11.06 kJ/mol. We believe that our pyrolysis system is transitional
between devolatilization and combustion.
PMID- 10680358
TI - Real-world vehicle emissions: a summary of the Ninth Coordinating Research
Council On-Road Vehicle Emissions Workshop.
AB - In April 1999, the Coordinating Research Council sponsored a workshop focusing on
our understanding of real-world emissions from motor vehicles. This summary
presents the latest information on in-use light- and heavy-duty vehicle tailpipe
and evaporative emissions, the effects of fuels on emissions, field programs
designed to understand the contribution of mobile sources to emission
inventories, efforts to evaluate and improve mobile source emission models,
progress of vehicle inspection/maintenance programs, and topics for future
research. While significant progress has been made in understanding in-use
vehicle emissions, further improvements are necessary. Moreover, the impact of
current and future changes in emission control technologies and control programs
will have to be monitored for effectiveness and incorporated into the emission
factor models.
PMID- 10680359
TI - Modeling relationships between indoor and outdoor air quality.
AB - Information about the ratio between indoor and outdoor concentrations (IO ratios)
of air pollutants is a crucial component in human exposure assessment. The
present study examines the relationship between indoor and outdoor concentrations
as influenced by the combined effect of time patterns in outdoor concentrations,
ventilation rate, and indoor emissions. Two different mathematical approaches are
used to evaluate IO ratios. The first approach involves a dynamic mass balance
model that calculates distributions of transient IO ratios. The second approach
assumes a linear relationship between indoor and outdoor concentrations. We use
ozone and benzene as examples in various modeling exercises. The modeled IO ratio
distributions are compared with the results obtained from linear fits through
plots of indoor versus outdoor concentrations.
PMID- 10680360
TI - An evaluation of the LPG vehicles program in the metropolitan area of Mexico
City.
AB - The environmental agency in the metropolitan area of Mexico City has launched a
program to introduce more energy-efficient modes of transport, one of which is
the use of alternative and less polluting fuels. With the perspective in mind, a
liquefied petroleum gas (LPG) fleet of vehicles is exempt of the mandatory "one
day without a car" program if the emission of pollutants is below the standard
authorized for that specific purpose. Today, about 28,000 light-duty vehicles and
heavy-duty trucks circulate in the area, most of them as aftermarket converted
vehicles. In this work, we evaluated regulated exhaust emission and other
parameters on 134 representative vehicles of that fleet. From the data obtained,
an estimate of emission factors and their contribution to the global emission in
the metropolitan area is provided. It is concluded that more than 95% of the in
use vehicles using LPG presented regulated emissions which exceeded in one or
more the environmental regulations values required for certification. The poor
maintenance of the vehicles and the type of conversion kit installed could be the
culprits of the results obtained.
PMID- 10680361
TI - A new dose model for assessment of health risk due to contaminants in air.
AB - The problem of making quantitative assessments of the risks associated with human
exposure to toxic contaminants in the environment is a pressing one. This study
demonstrates the capability of a new computational technique involving the use of
fuzzy logic and neural networks to produce realistic risk assessments. The
systematic analysis of human exposure involves the use of measurements and
models, the results of which are sometimes used in regulatory decisions or in the
drafting of legislation. Because of limited scientific understanding, however,
interpretation of models often involves substantial uncertainty. Extensive
measurement programs can be very expensive. The high complexity and inherent
heterogeneity of exposure analysis is still a major challenge. The approach to
this challenge tested here is to use a new model incorporating sophisticated
artificial intelligence algorithms. Exposure assessment often requires that a
number of factors be evaluated, including exposure concentrations, intake rates,
exposure times, and frequencies. These factors are incorporated into a system
that can "learn" the relevant relationships based on a known data set. The
results can then be applied to new data sets and thus be applied widely without
the need for extensive measurements. In this analysis, an example is developed
for human health risk through inhalation exposure to benzene from vehicular
emissions in the cities of Auckland and Christchurch, New Zealand. Risk factors
considered were inhaled contaminant concentration, age, body weight, and activity
patterns of humans. Three major variables affecting the inhaled contaminant
concentration were emissions (mainly from motor vehicles), meteorology (wind
speed, temperature, and atmospheric stability), and site factors (hilly, flat,
etc.). The results are preliminary and used principally to demonstrate the
technique, but they are very encouraging.
PMID- 10680362
TI - Modeling and direct sensitivity analysis of biogenic emissions impacts on
regional ozone formation in the Mexico-U.S. border area.
AB - A spatially and temporally resolved biogenic hydrocarbon and nitrogen oxides
(NOx) emissions inventory has been developed for a region along the Mexico-U.S.
border area. Average daily biogenic non-methane organic gases (NMOG) emissions
for the 1700 x 1000 km2 domain were estimated at 23,800 metric tons/day (62% from
Mexico and 38% from the United States), and biogenic NOx was estimated at 1230
metric tons/day (54% from Mexico and 46% from the United States) for the July 18
20, 1993, ozone episode. The biogenic NMOG represented 74% of the total NMOG
emissions, and biogenic NOx was 14% of the total NOx. The CIT photochemical
airshed model was used to assess how biogenic emissions impact air quality.
Predicted ground-level ozone increased by 5-10 ppb in most rural areas, 10-20 ppb
near urban centers, and 20-30 ppb immediately downwind of the urban centers
compared to simulations in which only anthropogenic emissions were used. A
sensitivity analysis of predicted ozone concentration to emissions was performed
using the decoupled direct method for three dimensional air quality models (DDM
3D). The highest positive sensitivity of ground-level ozone concentration to
biogenic volatile organic compound (VOC) emissions (i.e., increasing biogenic VOC
emissions results in increasing ozone concentrations) was predicted to be in
locations with high NOx levels, (i.e., the urban areas). One urban center-
Houston--was predicted to have a slight negative sensitivity to biogenic NO
emissions (i.e., increasing biogenic NO emissions results in decreasing local
ozone concentrations). The highest sensitivities of ozone concentrations to on
road mobile source VOC emissions, all positive, were mainly in the urban areas.
The highest sensitivities of ozone concentrations to on-road mobile source NOx
emissions were predicted in both urban (either positive or negative
sensitivities) and rural (positive sensitivities) locations.
PMID- 10680363
TI - Particulate matter modeling in the Los Angeles basin using SAQM-AERO.
AB - The SARMAP air quality model, enhanced with aerosol modeling capability, and its
associated components were developed to understand causes of ozone (O3) and
particulate matter exceedances in the San Joaquin Valley of California. In order
for this modeling system to gain increasing acceptance and use in guiding air
quality management, it is important to assess how transportable this modeling
system is across geographic domains. We describe the first application of the
modeling system outside the "home" domain for which it was developed and
evaluated. We have chosen the August 27-28, 1987, intensive monitoring period of
the Southern California Air Quality Study to evaluate the performance of the
modeling system and to assess its sensitivity to emission control options. The
predicted surface concentrations of O3 and other gas-phase species were spatially
and temporally correlated with measured data. The fractional normalized absolute
error was 0.32 to 0.36 for O3, and somewhat larger for other species. The
fractional normalized bias for O3 on August 27 and 28, 1987, was 0.02 to 0.04.
The simulated PM2.5 mass and constituent species concentrations reproduced the
magnitude and variability of the observed daytime concentrations at most
locations; however, nighttime PM2.5 concentrations were overpredicted by the
model. The model's response to emission control options was consistent with other
models of the same genre.
PMID- 10680364
TI - Trends in fine particle concentration and chemical composition in southern
California.
AB - Airborne fine particle mass concentrations in Southern California have declined
in recent years. Trends in sulfate and elemental carbon (EC) particle
concentrations over the period 1982-1993 are consistent with this overall
improvement in air quality and help to confirm some of the reasons for the
changes that are seen. Fine particle sulfate concentrations have declined as a
strict sulfur oxides (SOx) emission control program adopted in 1978 was
implemented over time. Fine particle elemental (black) carbon concentrations have
declined over a period when newer diesel engines and improved diesel fuels have
been introduced into the vehicle fleet. Organic aerosol concentrations have not
declined as rapidly as the EC particle concentrations, despite the fact that
catalyst-equipped cars having lower particle emission rates were introduced into
the vehicle fleet alongside the diesel engine improvements mentioned above. This
situation is consistent with the growth in population and vehicle miles traveled
in the air basin over time. Fine particle ammonium nitrate in the Los Angeles
area atmosphere contributes more than half of the fine aerosol mass concentration
on the highest concentration days of the year, emphasizing both the need for
accurate aerosol nitrate measurements and the likely importance of deliberate
control of aerosol nitrate as a part of any serious further fine particle control
program for the Los Angeles area.
PMID- 10680365
TI - Climatology of diurnal trends and vertical distribution of ozone in the
atmospheric boundary layer in urban North Carolina.
AB - Vertical measurements of ozone were made on a 610-m-tall tower located about 15
km southeast of Raleigh, NC, as part of an effort by the state of North Carolina
to develop a state implementation plan (SIP) for ozone control in the Raleigh
Metropolitan Statistical Area. During summer 1993, 1994, and 1995, ozone was
monitored at ground level, 250 m, and 433 m. Boundary layer wind, temperature,
and other meteorological variable profiles were determined from balloon
soundings. During summer 1996 and 1997, ozone was monitored at ground level, 76
m, 128 m, and 433 m. This paper presents the analysis and discussion of the five
year data. The evolutions of the convective boundary layer during daytime and the
stable nocturnal boundary layer (NBL) were found to have marked impacts on ozone
concentrations. A strong diurnal pattern, with an afternoon maximum and an early
morning minimum, was dominant at ground level, but it was much weaker at elevated
levels and insignificant above the NBL at night. Ozone deposition velocities at
night during the measurement periods were estimated to range from 0.09 to 0.64
cm/sec. We found evidence of regional transport of ozone and/or its precursors
from northwest and north of the site, which may play a role in high ozone events
in the Raleigh-Durham area. Ozone concentrations between the various elevated
levels were well correlated, while correlations between the ground and upper
levels were much weaker. However, a strong correlation was found between the
nighttime and early morning ozone concentrations (CR) in the residual layer above
the NBL and the maximum ground level concentration (Co max) the following
afternoon. Based on this correlation, the latter may be predicted by an
observational model Co max = 27.76e 0.016 CR.
PMID- 10680366
TI - Assessing the impact of differential measurement error on estimates of fine
particle mortality.
AB - In air pollution epidemiology, error in measurements of correlated pollutants has
been advanced as a reason to distrust regressions that find statistically
significant weak associations. Much of the related debate in the literature and
elsewhere has been qualitative. To promote quantitative evaluation of such
errors, this paper develops an air pollution time-series model based on
correlations among unit-normal variables. Assuming there are no other sources of
bias present, the model shows the expected amount of relative bias in the
regression coefficients of a bivariate regression of coarse and fine particulate
matter measurements on daily mortality. The model only requires information on
instrumental error and spatial variability, along with the observed regression
coefficients and information on the true fine-course correlation. Analytical
results show that if one pollutant is truly more harmful than the other, then it
must be measured more precisely than the other in order not to bias the ratio of
the fine and course regression coefficients. Utilizing published data, a case
study of the Harvard Six-Cities study illustrates use of the model and emphasizes
the need for data on spatial variability across the study area. Current
epidemiology time-series regressions can use this model to address the general
concern of correlated pollutants with differing measurement errors.
PMID- 10680367
TI - Factors influencing the variability of SO2 concentrations in Istanbul.
AB - The correlation between sulfur dioxide (SO2) concentrations measured at the
European and Asian sides of Istanbul and meteorological parameters is
investigated using principal component analysis (PCA) and multiple regression
analysis techniques. Several meteorological parameters are selected to represent
the atmospheric conditions during two winter periods: 1993-1994 and 1994-1995.
Six principal components are found to explain the majority of the observed
meteorological variability. Surface pressure, 850-mb temperature, and surface
zonal (east-west) and meridional (north-south) winds show high loadings on
separate factors identified by PCA. We seek dominant meteorological parameters
that control the SO2 levels at each monitoring station. Several multiple
regression analysis models are fitted to the data from each monitoring station
using six principal components and previous-day SO2 concentrations as independent
variables. Results suggest that the most important parameters, highly correlated
with SO2 concentrations in the Istanbul metropolitan area, are atmospheric
pressure and surface zonal and meridional winds. These components have more
influence on the determination of the air pollution levels at the Asian side than
at the European side.
PMID- 10680368
TI - Aerosols in a Mediterranean forest: sulfates, particle size distribution, and
growth rates.
AB - Particle size distribution measurements in 16 nonlinear intervals covering the
0.1-7.5 microns range and concurrent sulfate concentrations were continuously
recorded in September 1996 over the period of two weeks in a Mediterranean
forest. Sulfate size distribution was derived from a linear correlation fit
between the concentrations and the number of particles recorded at each particle
size interval. The results revealed two modal diameters for sulfates, with
typical diameters at 0.3 and 0.675 micron. These results were associated with two
different dominant chemical mechanisms governing sulfate formation. In order to
describe the dominant chemical mechanism, the growth law approach was applied.
Growth rates were determined using the parameter estimates of the fitted particle
size distribution function. By matching these data with sulfate concentrations,
the dominant chemical reactions were identified. The results have shown that
sulfate formation is governed by both homogeneous and heterogeneous reactions and
that the latter process was dominant. Condensation reactions prevailed in the
early morning and late afternoon, and volume reactions at night, particularly in
high-moisture conditions. From the observational data, the gas-to-particle
conversion rate for sulfur dioxide (SO2) at nighttime was also derived, yielding
a 2.18%/hr-1.
PMID- 10680369
TI - Particulates generated from combustion of polymers (plastics).
AB - This is an experimental study on the characterization of particulate (soot)
emissions from burning polymers. Emissions of polystyrene (PS), polyethylene
(PE), polypropylene (PP), polymethyl methacrylate (PMMA), and polyvinyl chloride
(PVC) plastics were studied. Combustion took place in a laboratory-scale,
electrically heated, drop-tube furnace at temperatures of 1300 and 1500 K, in
air. The nominal bulk (global) equivalence ratio, phi, was varied in the range of
0.5-1.5, and the gas residence time in the nearly isothermal radiation zone of
the furnace was approximately 1 sec. The particulate emissions were size
classified at the exit of the furnace, using a multi-stage inertial particle
impactor. Results showed that both the yields and the size distributions of the
emitted soot were remarkably different for the five plastics burned. Soot yields
increased with an increasing bulk equivalence ratio. Combustion of PS yielded the
highest amounts of soot (most highly agglomerated), several times more than the
rest of the polymers. More soot was emitted from PS at 1500 than at 1300 K.
Substantial amounts of soot agglomerates were larger than 9 microns. At 1500 and
1300 K, 35 and 29% of the soot mass, respectively, was PM2 (2 microns or
smaller). Emissions from PE and PP were remarkably similar to each other. These
polymers produced very low emissions at phi < or = 0.5, but emissions increased
drastically with phi, and most of the soot was very fine (70-97% of the mass was
PM2, depending on phi). Emissions from the combustion of PMMA were comparatively
low and were the least influenced by the bulk phi, and 79-95% of the emissions
were PM2. Combustion of PVC yielded the lowest amounts of soot; moreover, only 13
34% of the mass was PM2. On a comparative basis, at 1500 K, the following ranges
of particulate yields were PM2: 19-75 mg/g of PS, 8-36 mg/g of PE, 1.5-47 mg/g of
PP, 11-20 mg/g of PMMA, and 2-8 mg/g of PVC, depending on phi. These comparative
results demonstrate that PS produces the highest amounts of fine particulates,
followed by PP, PE, and PMMA, and then PVC. Burning these materials with excess
oxygen drastically reduces the particulate emissions of PE and PP, substantially
reduces those of PS, and mildly reduces those of PMMA and PVC.
PMID- 10680370
TI - Indoor/outdoor relationships for ambient PM2.5 and associated pollutants:
epidemiological implications in Lindon, Utah.
AB - Outdoor and indoor fine particulate species were measured at the Lindon
Elementary School in Lindon, Utah, to determine which components of ambient fine
particles have strong indoor and outdoor concentration correlations. PM2.5 mass
concentrations were measured using tapered element oscillating microbalance
(TEOM) monitors and by gravimetric analysis of Teflon filter samples. Gas-phase
HNO3, sulfur dioxide, particulate nitrate, strong acid, and particulate sulfate
were measured using annular denuder samplers. Soot was measured using quartz
filters in filter packs. Total particulate number was measured with a
condensation nucleus counter (CNC). Total particulate number and fine particulate
sulfate and soot were correlated for ambient and indoor measurements. Indoor
PM2.5 mass showed a low correlation with outdoor PM2.5 mass because of the
influence of coarse material from student activities on indoor PM2.5. Fine
particle acidity and the potentiation of biological oxidative mechanisms by iron
were not correlated indoors and outdoors.
PMID- 10680371
TI - Continuous emissions monitoring using spark-induced breakdown spectroscopy.
AB - A new technology for monitoring airborne heavy metals on aerosols and
particulates based on spark-induced breakdown spectroscopy (SIBS) was evaluated
at a joint U.S. Environmental Protection Agency (EPA)/U.S. Department of Energy
test at the rotary kiln incinerator simulator (RKIS) facility at EPA/Research
Triangle Park, NC, in September 1997. The instrument was configured to measure
lead and chromium in a simulated combustion flue gas in real time and in situ at
target levels of 15 and 75 micrograms/dry standard cubic meters. Actual metal
concentrations were measured during the tests using EPA Reference Method (RM) 29.
The SIBS technology detected both lead and chromium at the low- and high-level
concentrations. Additionally, the hardware performed without failure for more
than 100 hr of operation and acquired data for 100% of the RM tests. The chromium
data were well correlated with concentration increases resulting from duct
operations and pressure fluctuations that are known to entrain dust.
PMID- 10680372
TI - Near surface soil vapor clusters for monitoring emissions of volatile organic
compounds from soils.
AB - The overall objective of this research was to develop and test a method of
determining emission rates of volatile organic compounds (VOCs) and other gases
from soil surfaces. Soil vapor clusters (SVCs) were designed as a low dead
volume, robust sampling system to obtain vertically resolved profiles of soil gas
contaminant concentrations in the near surface zone. The concentration profiles,
when combined with a mathematical model of porous media mass transport, were used
to calculate the contaminant flux from the soil surface. Initial experiments were
conducted using a mesoscale soil remediation system under a range of experimental
conditions. Helium was used as a tracer and trichloroethene was used as a model
VOC. Flux estimations using the SVCs were within 25% of independent surface flux
estimates and were comparable to measurements made using a surface isolation flux
chamber (SIFC). In addition, method detection limits for the SVC were an order of
magnitude lower than detection limits with the SIFC. Field trials, conducted with
the SVCs at a bioventing site, indicated that the SVC method could be easily used
in the field to estimate fugitive VOC emission rates. Major advantages of the SVC
method were its low detection limits, lack of required auxiliary equipment, and
ability to obtain real-time estimates of fugitive VOC emission rates.
PMID- 10680373
TI - Performance of the annular denuder system with different arrangements for HNO3
and HNO2 measurements in Taiwan.
AB - Experiments on different annular denuder system (ADS) arrangements for sampling
nitrous acid (HNO2) and nitric acid (HNO3) gases were conducted in this study to
evaluate their sampling artifacts. The evaluation basis is the one that employed
one sodium chloride denuder for sampling HNO3 gas and two sodium carbonate
(Na2CO3) denuders for sampling HNO2 gas, which is a commonly employed ADS
arrangement in many field applications in the United States. A field study was
conducted in Hsinchu, Taiwan, and the results indicated that this ADS arrangement
may yield over 80% relative errors for HNO3 gas. It also showed that the relative
errors for HNO2 gas can be less than 10% as sampled with only one Na2CO3 denuder.
This is attributed to the fact that the ambient HNO3 concentration measured in
this study was relatively low while the HNO2 concentration was high, as compared
to typical concentrations of these two gases measured in the United States. The
sampling error of HNO3 gas may be due to high concentrations of N-containing
interfering species present in Taiwan's atmosphere. Because the relative sampling
errors of HNO3 and HNO2 gases depend mainly on their concentrations in the
atmosphere as well as concentrations caused by interfering species, the risk for
high error while measuring low HNO2 concentrations by only one Na2CO3 denuder is
also possible. As a result, it is suggested that pretests are necessary to
evaluate possible sources and degrees of sampling errors before field sampling of
HNO2 and HNO3 gases. The sampling errors of these two gases can, therefore, be
minimized with a better arrangement of the ADS.
PMID- 10680374
TI - Concentration of atmospheric pollutants in the gaseous emissions of medical waste
incinerators.
AB - The purpose of this paper is to quantify the production of medical waste from a
general hospital and to evaluate the atmospheric pollutant concentrations in
gaseous emissions associated with its incineration. A 3.8 kg (bed.day)-1
production of medical waste was estimated for 1998; its incineration is related
with an ash production of 0.3-0.4 kg (bed.day)-1. The concentrations of
atmospheric pollutants were estimated using emission factors, comparing the
effluents with and without control of atmospheric pollutants. The calculated
concentrations were compared with the emission limits established by Portuguese
legislation. The results indicate that, if there is no control of atmospheric
pollutants, their concentrations exceed the established limits. This is observed
even if correct operation and maintenance procedures are used. The emission
concentrations of dioxins are higher than the Portuguese emission limit, which is
particularly worrying due to the high toxicity of some of these compounds.
Generally, it is possible to reduce pollutant concentrations if appropriate
control equipment is used. The conclusions obtained clearly justify the great
concern regarding air pollution associated with medical waste incinerators
currently operating in Portugal.
PMID- 10680375
TI - Sulfur hexafluoride (SF6): global environmental effects and toxic byproduct
formation.
AB - This work provides information concerning possible global environmental
implications and personnel safety aspects that should be considered during the
commercial uses of sulfur hexafluoride (SF6). SF6 is an anthropogenically
produced compound, mainly used as a gaseous dielectric in gas insulated
switchgear power installations. It is a potent greenhouse gas with a high global
warming potential, and its concentration in the earth atmosphere is rapidly
increasing. During its working cycle, SF6 decomposes under electrical stress,
forming toxic byproducts that are a health threat for working personnel in the
event of exposure. Several precautions are recommended to avoid personnel
exposure to toxic byproducts: oxyfluoride levels or other byproduct
concentrations in the operating gas matrix should be traced to predetermine the
overall gas toxicity; contaminants should be systematically considered during
maintenance, chamber evacuation and system opening process; small SF6 quantities
leaking into air or stagnated pollutant concentrations in the operating field
should be analyzed and compared to the threshold limit values and permissible
exposure levels. New system design rules (i.e., hermetically sealed gas
compartments, gas recycling or disposal in the field area) and different handling
policies--both during maintenance and final disposal--now should be considered
globally to provide for environmental and personnel safety.
PMID- 10680376
TI - Predictions galore.
PMID- 10680377
TI - Fugi I luting cement.
PMID- 10680378
TI - Delegation a disservice?
PMID- 10680379
TI - New FDA web site targets online quackery.
PMID- 10680380
TI - Feds warn hospitals about drug-resistant infections.
PMID- 10680381
TI - Surveys says Americans concerned about diet.
PMID- 10680382
TI - Name one change or development in dentistry that you believe the profession will
witness in the 21st century.
PMID- 10680383
TI - Myofascial face pain. Clinical characteristics of those with regional vs.
widespread pain.
AB - BACKGROUND: The authors conducted a study to determine whether there are
differences in salient clinical characteristics between patients who have both
myofascial face pain, or MFP, and comorbid fibromyalgia, or FM, and patients who
have MFP but not FM. METHODS: The authors enrolled in the study 162 female
subjects who had histories of MFP. In physical examinations at the time of
initial consultation, they recorded facial pain signs and symptoms. At the
research interview follow-up (seven years post-consultation), participants were
screened for a lifetime history of FM and other health problems. In addition,
psychiatric interviewers conducted the Structured Clinical Interview for the
Diagnostic and Statistical Manual of Mental Disorders, Third Edition-Revised, to
assess each patient's history of depression and other psychiatric disorders.
RESULTS: Of the 162 participants, 38 (23.5 percent) reported a history of FM. At
the time of treatment for MFP, both the FM and non-FM groups had similar signs
and symptoms of MFP. At the time of the research interview follow-up,
participants with FM histories were significantly less likely than those without
FM histories to report that they were free of MFP. On recall, those with FM
histories reported experiencing more symptoms of MFP. Those with FM histories
also were more likely to have had major depression and to report somatization
symptoms. Finally, those who had FM more commonly had a history of facial pain's
interference with social and occupational functioning and had more severe pain
than did those without FM. CONCLUSIONS: Patients who have MFP and a history of
widespread pain suggestive of FM are likely to have more persistent and
debilitating MFP and to have higher rates of depression and somatization symptoms
than those who have no history of widespread pain.
PMID- 10680384
TI - Causes of failure among cuspal-coverage amalgam restorations: a clinical survey.
AB - BACKGROUND: Investigations of cuspal-coverage amalgam restorations suggest that
tooth fracture is the leading cause of failure, while for Class I and II
restorations, the leading cause is caries. In this study, the authors evaluated
the causes of failure for a large number of cuspal-coverage restorations.
METHODS: The causes of failure for 706 cuspal-coverage amalgam restorations were
determined through the use of a questionnaire. Dentists from a variety of dental
schools; Army, Navy, Air Force, Public Health and Veterans Affairs dental
clinics; and private practice were asked to record pertinent information
regarding patients and restoration failures from choices provided on a survey
form. RESULTS: The survey documented 706 failed restorations. Mandibular first
molars accounted for 36.25 percent of all failures. The majority of failures were
caused by fractured teeth (24.3 percent), caries (20 percent) and fractured
restorations (17.1 percent). Among all of the failed restorations, 82.15 percent
were restorable, 9.35 percent were repairable and 8.50 percent were
nonrestorable. Among the fractured teeth, 80 percent were restorable, 14.5
percent were nonrestorable and 5.5 percent were repairable. Among the carious
teeth, 84 percent were restorable, 8 percent were nonrestorable and 8 percent
were repairable. A chi 2 analysis revealed that tooth fracture was more likely to
be associated with nonrestorability than either caries (chi 2 = 5.013, P < .05)
or restoration fracture (chi 2 = 6.202, P < .05). CONCLUSIONS: The leading cause
of failure among the 706 restorations was tooth fracture, which resulted in
significantly greater numbers of nonrestorable teeth than either caries or
fractured restorations. CLINICAL IMPLICATIONS: Tooth fracture creates a greater
risk of nonrestorability than any other cause of failure. Replacement or coverage
of fracture-prone cusps is likely to improve the life expectancy of complex
amalgam restorations.
PMID- 10680385
TI - Dental unit waterline antimicrobial agents' effect on dentin bond strength.
AB - BACKGROUND: In response to concerns of bacterial biofilm colonization of dental
unit waterlines, a wide range of commercial intermittent and continuous chemical
treatments for dental unit waterlines have been developed and marketed. There has
been little research on the possible effect of continuous chemical treatment
regimens on dentin-bonding agents. The authors evaluate the effect of four
proposed antimicrobial agents used in dental unit waterlines on dentin bond
strength. METHODS: The authors used a fifth-generation dentin-bonding agent to
bond composite cylinders to molar dentin surfaces. They then used selected
antimicrobial agents as rinsing agents after conditioning. The composite
cylinders were shear tested, and their fracture strengths were compared
statistically. RESULTS: All proposed antimicrobial agents reduced dentin bond
strength. Proposed waterline treatment regimens of a diluted mouthrinse and
chlorhexidine significantly reduced dentin bond strength compared with sodium
hypochlorite and citric acid regimens. CONCLUSION: Dental professionals should be
aware of potential interactions between dental unit waterline antimicrobial
agents and dentin-bonding agents. Further research in this area is warranted, as
the clinical implications are uncertain at this time. CLINICAL IMPLICATIONS:
Dental unit waterline antimicrobial agents may adversely affect dentin bonding
strength.
PMID- 10680386
TI - Topical medications for orofacial neuropathic pain: a review.
AB - BACKGROUND: The authors discuss the local pharmacotherapy for chronic orofacial
neuropathic pain disorders such as neuropathies, neuromas and neuralgias.
METHODS: The authors conducted a systematic literature review on this topic. The
focus of the review involved the two most commonly applied medications for
neuropathic disorders--local anesthetics and capsaicin. Other compounds such as
nonsteroidal anti-inflammatory drugs, sympathomimetic agents, anticonvulsants and
N-methyl-D-aspartate receptor antagonists also were reviewed. The medication
delivery and retention methods appropriate for oral and perioral disease and pain
control are described in this article. RESULTS: There are an ever-increasing
number of agents that can be used to help patients with neuropathic-based oral
and perioral pain problems. Moreover, a clear advancement in the delivery of
these medications is the development of a vehicle-carrier agent (pluronic
lecithin organogel) that can penetrate the mucosa and cutaneous tissues and carry
the active medication with it to the treatment site. The major caveat underlying
these treatment strategies is that except for patient testimony and a few
studies, there are limited empirical data on the efficacy of most of these new
formulations, and additional research is clearly needed. CONCLUSIONS: Because of
their rapid onset and low side-effect profile, topical medications offer a
distinct advantage over systemic administration for those orofacial disorders
that are regional, near the surface and chronic and that demonstrate some
response such as pain relief to topical or subcutaneous anesthetics. CLINICAL
IMPLICATIONS: Practicing dentists now have some new tools they can use to help
manage patients who have a chronic nerve pain disorder in and around the mouth.
PMID- 10680387
TI - Repairing iatrogenic root perforations.
AB - BACKGROUND: Post preparation is an integral part of restoring endodontically
treated teeth in indicated cases. Iatrogenic perforation of the root can result
from preparing post space and can severely compromise the prognosis of the tooth.
CASE DESCRIPTION: Two years after a patient's maxillary lateral incisor was
restored with a post-retained composite resin, he went to a dental school
emergency clinic with a chief complaint of soft-tissue swelling adjacent to the
tooth. The authors took a periapical radiograph that revealed evidence of a
circumscribed radiolucent lesion associated with the distal midroot area and a
periapical radiolucency. Based on the radiograph, the authors suspected that the
canal preparation for the post and the post placement had perforated the root at
the base of the post. CLINICAL IMPLICATIONS: The authors used a combined surgical
and orthograde approach with a biocompatible restorative material and a clear,
plastic light-transmitting post to repair the iatrogenic perforation.
PMID- 10680388
TI - Usefulness of posture training for patients with temporomandibular disorders.
AB - BACKGROUND: Many practitioners have found that posture training has a positive
impact on temporomandibular, or TMD, symptoms. The authors conducted a study to
evaluate its effectiveness. METHODS: Sixty patients with TMD and a primary muscle
disorder were randomized into two groups: one group received posture training and
TMD self-management instructions while the control group received TMD self
management instructions only. Four weeks after the study began, the authors
reexamined the subjects for changes in symptoms, pain-free opening and pressure
algometer pain thresholds. In addition, pretreatment and posttreatment posture
measurements were recorded for subjects in the treatment group. RESULTS:
Statistically significant improvement was demonstrated by the modified symptom
severity index, maximum pain-free opening and pressure algometer threshold
measurements, as well as by the subjects' perceived TMD and neck symptoms.
Subjects in the treatment group reported having experienced a mean reduction in
TMD and neck symptoms of 41.9 and 38.2 percent, respectively, while subjects in
the control group reported a mean reduction in these symptoms of 8.1 and 9.3
percent. Within the treatment group, the authors found significant correlations
between improvements in TMD symptoms and improvements in neck symptoms (P < .005)
as well as between TMD symptom improvement and the difference between head and
shoulder posture measurements at the outset of treatment (P < .05). CONCLUSIONS:
Posture training and TMD self-management instructions are significantly more
effective than TMD self-management instructions alone for patients with TMD who
have a primary muscle disorder. PRACTICE IMPLICATIONS: Patients with TMD who hold
their heads farther forward relative to the shoulders have a high probability of
experiencing symptom improvement as a result of posture training and being
provided with selfmanagement instructions.
PMID- 10680389
TI - Treating severe bruxism with botulinum toxin.
AB - BACKGROUND: Locally administered botulinum toxin, or BTX, is an effective
treatment for various movement disorders. Its usefulness in treating bruxism,
however, has not been systematically evaluated. SUBJECTS AND METHODS: The authors
studied 18 subjects with severe bruxism and whose mean duration of symptoms was
14.8 +/- 10.0 years (range three-40 years). These subjects audibly ground their
teeth and experienced tooth wear and difficulty speaking, swallowing or chewing.
Medical or dental procedures had failed to alleviate their symptoms. The authors
administered a total of 241 injections of BTX type A, or BTX A, in the subjects'
masseter muscles during 123 treatment visits. The mean dose of the BTX A was 61.7
+/- 11.1 mouse units, or MU (range 25-100 MU), per side for the masseter muscles.
RESULTS: The mean total duration of response was 19.1 +/- 17.0 weeks (range six
78 weeks), and the mean peak effect on a scale of 0 to 4, in which 4 is equal to
total abolishment of grinding, was 3.4 +/- 0.9. Only one subject (5.6 percent)
reported having experienced dysphagia with BTX A. CONCLUSION: The results of this
study suggest that BTX administered by skilled practitioners is a safe and
effective treatment for people with severe bruxism, particularly those with
associated movement disorders. It should be considered only for those patients
refractory to conventional therapy. Future placebo-controlled studies may be
useful in further evaluating the potential of BTX in the treatment of bruxism.
PMID- 10680390
TI - Limiting sensitivity after quadrant scaling and root planing.
PMID- 10680391
TI - Trends in total caries experience: permanent and primary teeth.
AB - BACKGROUND: This article is the last in a series of three that focuses on recent
changes in the caries status of children aged 18 years or younger in the United
States. METHODS: This study is based on analyses of data regarding total carious
(treated and untreated) permanent and primary teeth among children 6 to 18 years
old and children 2 to 10 years old from the first and third National Health and
Nutrition Examination Surveys, or NHANES I and NHANES III. The NHANES is
periodically conducted by the National Center for Health Statistics of the
Centers for Disease Control and Prevention. RESULTS: The cumulative number of
carious permanent teeth, both treated and untreated, among 6- to 18-year-olds
decreased 57.2 percent, from 4.44, as measured in NHANES I, to 1.90, as measured
in NHANES III. The cumulative number of carious primary teeth, both treated and
untreated, among 2- to 10-year-olds decreased 39.7 percent, from 2.29, as
measured in NHANES I, to 1.38, as measured in NHANES III. CONCLUSIONS: Since the
1970s, the cumulative number of carious permanent and primary teeth, both treated
and untreated, has declined substantially among children in the United States.
PRACTICE IMPLICATIONS: Effective prevention has reduced caries in children. As a
result, dental practice will be more focused on maintaining intact dentitions
than on repairing teeth damaged by disease.
PMID- 10680392
TI - Treating bruxism and clenching.
PMID- 10680393
TI - Another approach to learning about health disparities: working toward
individualized therapy.
PMID- 10680394
TI - The war on fraud and its effect on dentistry.
AB - The fraudulent actions of a disreputable few people in the health care industry
have caused enormous losses to government and private health care payers. Fraud
can take a number of forms, but usually is based on some form of deceit. In
response, law enforcement efforts have been aided by a number of recent anti
fraud statutes and significant new resources. The challenge to dentistry is to
ensure that legitimate efforts to fight fraud do not unduly burden practitioners,
the vast majority of whom are honest.
PMID- 10680395
TI - Ask the expert. How much overhead is too much?
PMID- 10680396
TI - Holding HMOs responsible.
PMID- 10680397
TI - The woman physician in the year 2000.
PMID- 10680398
TI - American women physicians in 2000: a history in progress.
AB - This article surveys major trends in the history of women physicians in American
medicine during the 20th century, noting especially factors that have elicited
renewed and increasingly public attention during the past two decades. These
include the challenges of achieving greater professional visibility while also
balancing family and career, of sustaining women physicians' legacy of commitment
to women's health and primary care medicine without reinforcing the traditional
stereotype that these are the specialties "best suited" to women doctors, and of
addressing the need for more ethnic and racial diversity in the medical
profession. Other recent developments include the leveling off of the number of
women entering medical school and the increasing tendency of both men and women
physicians to practice as employees.
PMID- 10680399
TI - Women in academic medicine.
AB - Women now constitute 43% of US medical students, 37% of residents, and 27% of
full-time medical school faculty. Less than 11% of women faculty are full
professors, however, compared to 31% of men, and these proportions haven't
changed in more than 15 years. Since the proportion of women reaching the top
ranks remains relatively low, the pool of women available for leadership
positions in academic medicine is still small. This review article first
summarizes recent data on women's representation in academic medicine and then
discusses why they are not succeeding at the same pace as men. Reasons include a
complex combination of women's choices, sexism, cultural stereotypes, constraints
in combining family responsibilities with professional opportunities, and lack of
effective mentoring. Multiple approaches are required to overcome these
"cumulative disadvantages," among them improving the gender climate at academic
medical centers; the mentoring of women faculty, residents, and students; and
skill-building opportunities for women.
PMID- 10680400
TI - What impact have women physicians had on women's health?
AB - The proportion of women in medicine in the United States is approaching that of
men, but women physicians are still the minority in positions of power. Research
has shown that women physicians order more preventive tests for women patients,
are more attuned to patients' psychosocial needs, and have developed more patient
oriented communication styles than men physicians. Recent organized efforts of
women physicians have brought attention to many gender gaps in medical research
and practice. If more women move into policy-making positions, especially in
education and research, their gender-sensitive perspective could permanently
influence the profession as a whole.
PMID- 10680401
TI - Physician unions: organizing women in the year 2000.
AB - Interest in physician unions is growing, but surprisingly little has been written
about whether union membership addresses the particular needs and interests of
women physicians. We begin by looking at the history of physician unions in the
United States and then examine physician unions today, and how labor laws
influence union membership of physicians. The third section looks at why women
join unions, whether these reasons hold true for women physicians, and what role
women are playing in physician unions. Finally, we give examples of union
responses to gender discrimination and such issues as maternity leave, salary
inequities, sexual harassment, and promotions. Since women are prominent as
leaders in physician unions, these unions seem to be responsive to the needs of
their women members.
PMID- 10680402
TI - The subspecialty training, practice type, and geographical distribution of
recently trained ophthalmologists: a study of male and female physicians.
AB - OBJECTIVE: To characterize the distribution of male and female ophthalmologists
with regard to practice type, subspecialty training, rural-urban distribution,
and regional distribution. METHODS: Ophthalmology Matching Program files
containing the records of residents who began their second year at accredited
programs between 1986 and 1990 (inclusive), were compared to membership files of
the American Academy of Ophthalmology. Practice locations for each individual
were classified according to region, stage, and Rural-Urban Continuum County
Code, as defined by the US Department of Agriculture. RESULTS: This cohort
comprised 2,494 individuals, 77.1% (1922) of whom were male and 22.9% (572) of
whom were female. Group practice was most common (55.9% for women and 61.3% for
men). More women were in salaried positions associated with health maintenance
organizations (p = 0.006) and academic settings (p < 0.001) than were men.
Notable differences in subspecialty choice were restricted to pediatric
ophthalmology, chosen three times more frequently by women, and vitreoretinal
diseases/surgery, chosen twice as often by men. Only 5.6% of women selected
nonmetropolitan practice locales compared to approximately twice that percentage
of men. The Middle Atlantic and New England regions attracted more women, while
the South Atlantic attracted more men.
PMID- 10680403
TI - Medical faculty's views and experiences of parental leave: a collaborative study
by the Gender Issues Committee, Council of Ontario Faculties of Medicine.
AB - OBJECTIVES: To examine medical faculty's actual and ideal parental leave
arrangements with the aim of informing policy decisions. Leave lengths, effect on
career, financial arrangements, and availability of temporary replacements were
explored. METHODS: All medical faculty (6387) in Ontario, Canada were surveyed by
mail and asked about parental leave experiences since 1990. Responses of men and
women were compared as were those of leave takers and the entire group. RESULTS:
Thirty-two percent (n = 996) of the 3107 respondents were women and 68% (n =
2067) were men. Ninety-eight percent (n = 317) of new mothers had taken maternity
leave, while only 21% (n = 159) of new fathers had. Both paid and unpaid leave
was generally shorter than that allowed by law or identified as ideal. Parental
leave had a somewhat negative effect on the careers of all faculty. Women were
more worried than men about the effect of their absence on colleagues' work and
more generous with ideal leave length and funding. Temporary replacement of leave
takers was central to an effective leave policy. CONCLUSIONS: Institutional and
academic culture may cause new parents to take suboptimal leave despite
legislation allowing more. A change in the work environment is required for
medicine to offer its teachers what it teaches--that infants benefit from
nurturing, nursing, and stability early in life.
PMID- 10680404
TI - Continuing medical education habits of US women physicians.
AB - OBJECTIVES: To quantify the time women physicians spend on continuing medical
education (CME) in total and by type of activity and to assess the impact of
various demographic and professional characteristics on CME practices. METHODS:
We analyzed CME habits among 4501 female physicians (a 59% response rate) using a
1994 national questionnaire-based survey, the Women Physicians' Health Study.
RESULTS: US women physicians reported spending a monthly mean of 12.5 hours on
CME, including 5.1 hours reading medical journals, 3.1 reading medical textbooks,
3.7 attending live CME lectures, 0.7 listening to CME audio tapes, and 0.4
watching medical television or videos. They also spent 0.9 hours per month
learning from lay health media. Physicians with subspecialty training, medical
school employment, and a non-US birthplace reported significantly (p < 0.05) more
CME hours; age, ethnicity, region, specialty type, practice locale, career
satisfaction, and board certification did not significantly predict reported CME
hours. CONCLUSIONS: US women physicians reported spending an average of one-half
hour each work day on CME, including about one hour per week reading medical
journals, their most commonly reported CME activity.
PMID- 10680405
TI - Differences in the preparation and practice of male and female physicians from
combined baccalaureate--MD degree programs.
AB - OBJECTIVE: To account for age and premedical education in determining whether or
not men and women medical school graduates differ significantly in opinions of
their medical school preparation, in professional activities, and in personal
qualities and values. METHODS: 727 graduates (1983-1987) of seven combined
baccalaureate-MD degree programs were surveyed. Men's and women's responses were
compared. RESULTS: Women graduates were more likely than men to work less than
full time and to report less preparation in the basic sciences, less scholarly
activity, and more concern about psychosocial issues. CONCLUSION: Differences
between men and women graduates have persisted despite women's increased access
to medical school. Even a special curriculum does not moderate these differences.
We call on academic medicine to value humanism in health care, not just
economics.
PMID- 10680406
TI - The gender composition of the medical profession in Mexico: implications for
employment patterns and physician labor supply.
AB - The gender composition of the medical profession is changing rapidly in many
parts of the world, including Mexico. We analyze cross-sectional and longitudinal
data on sex differences in physician employment from household employment
surveys. The results suggest that Mexico is a particularly interesting example of
the feminization of physician employment. Female enrollment in medical school
increased from 11% in 1970 to about 50% in 1998. The increased participation of
women in medicine seems to be accompanied by differences in employment patterns
that could generate significant reductions in the total supply of physician hours
of service. Women physicians are unemployed at a much higher rate than men and
hence account for half of underused physician human capital. The results suggest
that improved educational opportunities do not translate automatically into equal
employment opportunities.
PMID- 10680407
TI - Egyptian medical women, past and present.
AB - In ancient Egypt, at least one woman carried the title of physician. University
education for women started in 1930. Today, women are practicing in all
disciplines and are effective in health care. Egyptian medical women represent
35% to 45% of the staff of faculties of medicine and about one-third of all
medical graduates. They have contributed to the improvement of health,
particularly in maternal and child health, and are role models for young girls in
rural areas.
PMID- 10680408
TI - Why single payer? Why now?
AB - US health care costs are the highest in the world and are again rising. A
reopening of debate on health care reform is imminent. More than 44 million
Americans have no health insurance, an increase of 11 million people since 1989.
Although women have been slightly more likely to have health insurance than men,
recent declines in Medicaid enrollment resulting from welfare reform are eroding
this slim advantage. Being uninsured is associated with compromised access to
primary care and an increased risk of dying. At least 29 million Americans are
underinsured; although they have some insurance, they would nonetheless be
bankrupted by a major illness. A single-payer national health insurance system
would cover all Americans in a non-profit, tax-funded system similar to Social
Security. It would simplify health administration, saving at least $100 billion
annually on paperwork and redirecting that money to patient care.
PMID- 10680409
TI - Prevention works for women: women's health at the CDC.
AB - Actively protecting America's health and safety, the Centers for Disease Control
and Prevention (CDC) focuses on four priorities: 1) strengthening science for
public health action, 2) collaborating with health care partners for prevention,
3) promoting healthy living at every stage of life, and 4) promoting health
globally. The CDC plays a critical role in promoting the health and safety of
women across the lifespan, through programs on human immunodeficiency virus
infection, injury, contraceptive safety and efficacy, adolescent health, smoking,
breast and cervical cancer, cardiovascular disease, and reproductive health.
PMID- 10680410
TI - Randomized community trial of a breast self-examination skills-building
intervention for inner-city African-American women.
AB - OBJECTIVE: Breast cancer is the most common cancer in women, and African-American
women are less likely to detect breast cancer at its early stages. Few controlled
trials of interventions to increase breast self-examination (BSE) among low
income minority women have been conducted. Our objective was to test a small
group workshop intended to build BSE skills and promote BSE among low-income
African-American women. METHODS: A randomized community field trial tested a BSE
skills-building workshop based on social cognitive theory of behavior change
compared to a matched sexually transmitted diseases prevention workshop, with one
and three-month follow-ups for assessing increased practice of BSE. RESULTS:
Women who did not regularly practice BSE and participated in a BSE skills
building workshop were more likely to practice BSE than women in the comparison
intervention at the one- (OR = 3.5, p = 0.04) and three-month follow-ups (OR =
4.9, p = 0.01). These results were not related to risk perceptions heightened by
the intervention. Across conditions and controlling for covariates in a
multivariate model, performing regular BSE was most closely associated with
having received any formal BSE instruction. CONCLUSION: BSE skills building can
effectively increase use of BSE among low-income African-American women who face
multiple and competing health risks. The small-group experience is an important
element in fostering norms for practicing BSE and enhancing BSE practices.
PMID- 10680411
TI - "The speed of blur...".
PMID- 10680412
TI - Optometry's research profile: we are on the way up; how high can we go?
PMID- 10680413
TI - The changing faces of optometry.
PMID- 10680414
TI - Competency-based optics instruction.
AB - BACKGROUND: The Competency-Based Instruction (CBI) system has been used to teach
physics for more than 20 years in the Michigan State University Physics
Department. In this approach, traditional lectures have been replaced by a
learning environment that contains a variety of instructional aids, including
written materials, computer-assisted instruction, and interactions with a
consultant. The CBI system allows students to adjust their pace through the
course, moving nearly as quickly as they are able, with constant feedback to the
student on his or her progress. METHODS: I have used an adapted version of the
CBI system for use in the Physical Optics and Photometry course of the University
of Missouri-St. Louis, School of Optometry for four years. This article will
describe the mechanics of the system and discuss experiences with it.
PMID- 10680415
TI - Pacific's experience with Web-based instruction: bats in the belfry or Webs in
the classroom?
AB - BACKGROUND: There is a revolution underway in education that involves a shift
from the traditional lecture style of information presentation toward a more
active style of learning. Many educators now believe that students must actively
participate in the learning process for information to be truly understood and
retained. Coincident with this revolution, there is an increased understanding
that the body of knowledge in most professions has become too large to retain in
the brains of individuals. These concepts have opened the door to innovative,
computer-based educational techniques. METHODS: Pacific University College of
Optometry has used a variety of Web-based educational methodologies in selected
classes. These have ranged from shifting classes totally to the Web, to using the
Web for pre-class preparation. RESULTS: Initial student acceptance of Web-based
courses has been good. However, an undesirable trend has emerged--the tendency
for students to print out Web-presented material rather than reading from the
computer screen. Other concerns with shifting material from lecture to the Web
include peer and administrator acceptance of this teaching style and issues
associated with evaluation of professors who no longer give stand-up lectures.
CONCLUSIONS: Changes in educational theory are making their way into the Schools
and Colleges of Optometry. These changes will place greater reliance on active
learning, reduced student memorization, and increased use of computers as
information storage and retrieval devices. This will change the fundamental way
in which students are educated, and this, in turn, will change the way in which
future doctors, patients, and computers interact in clinical settings.
PMID- 10680416
TI - Ocular toxicity of systemic medications: a case series.
AB - BACKGROUND: There are many visually threatening conditions that may result from
long-term use of systemic medications. Many of these adverse side effects can be
greatly reduced or prevented with close monitoring of patients. In view of
current knowledge, updated clinical guidelines for appropriate monitoring of
ocular toxicity from systemic medications need to be developed for the eye care
practitioner. CASE REVIEW: There have been many reports of ocular toxicity from
isoniazid, thioridazine, steroids, and amiodarone therapy. Clinical cases
illustrating possible adverse ocular side effects are presented, which include
INH-induced optic neuropathy, phenothiazine-induced retinopathy, steroid-induced
glaucoma, and vortex epitheliopathy secondary to amiodarone. CONCLUSION:
Optometrists should be aware of the potential for ocular side effects from
systemic medications. Eye care guidelines for monitoring ocular side effects from
thioridazine, INH, steroids, and amiodarone use are suggested.
PMID- 10680417
TI - Iowa's pediatric low-vision services.
AB - BACKGROUND: Reports in the literature concerning best practice for the evaluation
and management of children with visual impairments are limited, with a resulting
lack of information concerning the potential for optimizing vision to enhance
general development and assist with the educational needs of this population.
METHOD: The development of a multidisciplinary approach to provide low-vision
services for children with visual impairment has occurred over the past 18 years
in Iowa. In that time, 1,348 children from around the state of Iowa have been
evaluated through an itinerant low-vision service program, coordinated by the
Iowa Braille School. RESULTS: A low-vision clinic model--designed to provide
services (primarily) for academic students--was not meeting the needs of the
pediatric low-vision population in the state. After a statewide review of the
program, changes were made that have resulted in low-vision services being
provided to a greater and more diverse number of students. The roles of the
various members of the multidisciplinary team will be reviewed. Changes in large
print orders and use by special education teachers in the state as a direct
result of the low-vision services will also be discussed. CONCLUSION: Ongoing,
comprehensive multidisciplinary low-vision services--including optometric low
vision care as a key component--are necessary to help children with visual
impairments meet their educational, vocational, and avocational needs. With
ongoing low-vision services, unnecessary costs such as those associated with
large-print materials can be reduced, thereby creating significant savings to
local, state, and federal special educational services.
PMID- 10680418
TI - A comparison of Fluoracaine and Fluorox on corneal epithelial cell desquamation
after Goldmann Applanation Tonometry.
AB - BACKGROUND: The purpose of this study was to quality the frequency and amount of
corneal desquamation from a sodium fluorescein/proparacaine combination
(Fluoracaine) as compared with sodium fluorescein/benoxinate combination
ophthalmic solution (Fluorox) after Goldmann Applanation Tonometry. METHODS: One
drop of Fluoracaine was randomly instilled into one eye and one drop of Fluorox
was instilled into the opposite eye of the same patient. Intraocular pressures
(IOPs) by GAT and tear break-up times (TBUTs) were taken. Corneal stinging was
compared. Corneal integrity by Cornea and Contact Lens Research Unit (CCLRU)
standards was evaluated at 0, 3, 7, 10, 15, and 20 minutes after instillation of
the ophthalmic solutions. RESULTS: Sixty eyes of 30 patients were observed Forty
seven percent of the patients reported Fluorox to string more than Fluoracaine;
23% of the patients reported that Fluoracaine stings more than Fluorox; and 30%
the patients reported no difference. Average TBUTs were 6.87 and 7.17 seconds
with Fluoracaine and Fluorox, respectively. Fluoracaine produced micro- and
macropunctate keratitis of the superficial epithelium in 31% to 45% of the
cornea. Fluorox caused superficial micropunctate keratitis in about 16% to 30% of
the cornea. At 20 minutes, all eyes with Fluoracaine and all eyes but one with
Fluorox had corneal desquamation. CONCLUSIONS: Fluoracaine causes marginally less
stinging--however, clinically and statistically more corneal desquamation--than
Fluorox after GAT. Corneal integrity after use of Fluoracaine should be evaluated
even 20 minutes after GAT procedures for corneal disruption.
PMID- 10680419
TI - Internet research: improving traditional community analysis before launching a
practice.
AB - Optometric practice management experts have always recommended that optometrists
thoroughly research the communities in which they are considering practicing.
Until the Internet came along, demographic research was possible but often
daunting. Today, say these authors, it's becoming quite a bit easier ... and they
show us how.
PMID- 10680420
TI - Is an online discount broker right for you?
AB - Let's face it ... you will eventually do all your investing online, if you're not
doing so already. But how can you distinguish between the many brokerage choices?
These authors offer their insight into finding the best online broker at the most
reasonable cost.
PMID- 10680421
TI - Computing & technology.
PMID- 10680422
TI - The drug war.
PMID- 10680423
TI - The costly quest for certainty.
PMID- 10680424
TI - Not insured, and not worried.
PMID- 10680425
TI - The cost of coverage.
PMID- 10680426
TI - Health care decisions and the community.
PMID- 10680427
TI - Community forums bring together Minnesota's health care players.
PMID- 10680428
TI - Is the experimental treatment exclusion used appropriately?
PMID- 10680429
TI - Pediatrics: a century of caring.
PMID- 10680430
TI - MMA reviews prescription drug plans.
PMID- 10680431
TI - Minnesota's Medicare PRO focuses on quality improvement.
PMID- 10680432
TI - Diagnosis and management of carotid stenosis: a review.
AB - Since its introduction in the 1950s, carotid endarterectomy has become one of the
most frequently performed operations in the United States. The tremendous appeal
of a procedure that decreases the risk of stroke, coupled with the large number
of individuals in the general population with carotid stenosis, has contributed
to its popularity. To provide optimal patient care, the practicing physician must
have a firm understanding of the proper evaluation and management of carotid
stenosis. Nevertheless, because of the large number of clinical trials performed
over the last decade addressing the treatment of stroke and carotid
endarterectomy, the care of patients with carotid stenosis remains a frequently
misunderstood topic. This review summarizes the current evaluation and treatment
options for carotid stenosis and provides a rational management algorithm for
this prevalent disease process.
PMID- 10680433
TI - Minnesota surveillance for unexplained deaths and critical illnesses of possible
infectious cause.
PMID- 10680434
TI - Itraconazole trough concentrations in antifungal prophylaxis with six different
dosing regimens using hydroxypropyl-beta-cyclodextrin oral solution or coated
pellet capsules.
AB - We have previously shown that a trough concentration of at least 500 ng ml-1
itraconazole is necessary for an effective antifungal prophylaxis in neutropenic
patients. Since the bioavailability of itraconazole is reduced in these patients,
a satisfactory dosing regimen remains to be defined. In this study, six dosing
regimens with itraconazole capsules 400, 600 or 800 mg day-1, itraconazole
solution 400 mg day-1 (additional loading dose: 400 mg day-1 solution for 2
days), 800 mg day-1 or 400 mg day-1 (additional loading dose: 800 mg day-1
capsules for 7 days, s/c1200) were compared during 160 courses of
myelosuppressive chemotherapy in 123 patients with acute leukaemia. After the
first week, patients taking 800 mg day-1 or 400 mg day-1 (s/c1200) itraconazole
solution achieved significantly higher trough concentrations (high-performance
liquid chromatography) than patients in other groups (P < 0.05) and 87 and 100%,
respectively, of these had concentrations > 500 ng ml-1. Contrary to a dose of
400 mg day-1, a dose of 800 mg day-1 itraconazole solution induced severe nausea
and vomiting in 46% of the patients. We conclude that 400 mg day-1 itraconazole
solution with a loading dose of 800 mg day-1 capsules for 7 days resulted in
sufficient trough concentrations from the first week onwards and appears to be
suitable for antifungal prophylaxis in neutropenic patients.
PMID- 10680435
TI - Killer activity at different pHs against Cryptococcus neoformans var. neoformans
serotype A by environmental yeast isolates.
AB - Yeast isolates that share the same habitats as Cryptococcus neoformans var.
neoformans serotype A in a restricted Mediterranean area were assayed in order to
verify their killer activity against Cr. neoformans strains isolated from
clinical and environmental sources. Many of the environmental yeast isolates
expressed the killer phenomenon against the assayed strains of Cr. neoformans.
Two species of Candida: Candida parapsilosis and Candida famata, and Pichia
carsonii, were the most active killers at pH 4.6, 5.0 and 5.6 levels encountered
in pigeon and canary guanos. Killer activity by C. parapsilosis is reported for
the first time. The authors hypothesized that the killer phenomenon exerted by
yeast species with heavy killer activity against Cr. neoformans would lend
themselves for use as biological control agents against sensitive strains of Cr.
neoformans when directly inoculated into the habitats of Cr. neoformans.
PMID- 10680436
TI - Dematiaceous fungal pathogens: analysis of ribosomal DNA gene polymorphism by
polymerase chain reaction-restriction fragment length polymorphism.
AB - Restriction fragment length polymorphisms (RFLP) of ribosomal gene small subunit
(SSU rDNA) and internal transcribed spacer (ITS) regions was examined in 12
isolates of dematiaceous agents of chromoblastomycosis and phaeohyphomycosis. The
amplicon length of the fragment ITS1-ITS4, comprising the 5.8 rDNA and ITS1-ITS2
spacers, ranged in size from 620 to 690 bp. This result indicated a polymorphism
of size in this region. Additionally the RFLP profiles showed a high degree of
inter- and intra-specific variability. In contrast, the SSU rDNA amplification,
using NS1-NS2 primers, originated a fragment of approximately 570 bp and its
restriction profile proved to be well conserved among the species studied and was
clustered into only two genetically heterogeneous groups, the first one formed by
Fonsecaea pedrosoi and Fonsecaea compacta and the second one formed by
Cladophialophora (Cladosporium) carrionii, Cladophialophora (Xylohypha) bantiana,
Phialophora verrucosa and Rhinocladiella species.
PMID- 10680437
TI - Isolation of total RNA from dermatophytes.
AB - We report a method for the preparation of total RNA from the anthropophilic
dermatophyte Trichophyton rubrum. To generate large quantities of mycelia, the
fungus was grown in liquid culture medium. The harvested mycelial mass was ground
to a fine powder in liquid nitrogen and homogenized in guanidine isothiocyanate
buffer followed by ultracentrifugation of the obtained suspension through a
caesium chloride gradient. Analysis of the prepared RNA showed two prominent
ribosomal RNA (rRNA) bands of about 3.36 and 1.82 kb. Northern blot hybridization
with a beta-actin cDNA confirmed the high quality of the fungal mRNA. Successful
isolation of RNA from two other dermatophyte species, namely Trichophyton
mentagrophytes and Microsporum canis, demonstrated the general applicability of
the described procedure.
PMID- 10680438
TI - Bacterial flora accompanying Candida yeasts in clinical specimens.
AB - From 1986 to 1988, in the prefluconazole era, 67,765 clinical specimens from the
Gottingen University Hospital were investigated for bacteria and fungi in our
institution. Oral and throat swabs, respiratory secretions, gastric juices,
faeces, urine, genital swabs, blood, wound secretions and skin swabs were
analysed for yeast-like fungi, and opportunistic or pathogenic bacteria. A total
of 5195 specimens (7.7%) yielded Candida spp. alone or in combination with
bacteria (fungal (F-) group) and 62,570 specimens yielded bacteria only or
remained sterile (non-fungal group, N-group). Elevated rates of accompanying
bacteria were detected with Candida spp. colonizing blood, urine, and skin. Among
the dominant bacterial isolates, the distribution of staphylococci and
enterococci did not reflect a distinct association pattern. Among the
enterobacterial isolates from patients in intensive care, colonization patterns
of the throat, gastric juices, and faeces reflected the use of a selective
decontamination of the digestive tract (SDD). A statistically significant
association between Candida and enterobacteria of the genus Enterobacter which
was unaffected by SDD, was observed throughout this study. Such an association
pattern was also observed, to a lesser extent, with the related genera Klebsiella
and Serratia, but not with Escherichia coli.
PMID- 10680439
TI - In vitro susceptibility of yeasts for fluconazole and itraconazole. Evaluation of
a microdilution test.
AB - In vitro susceptibilities were determined for a total of 159 clinical isolates
and 12 reference strains of yeasts belonging to different Candida species
including 94 Candida albicans strains, and further genera such as Cryptococcus,
Trichosporon, Geotrichum and Saccharomyces. Minimum inhibitory concentration
(MIC) values for fluconazole and itraconazole were assessed using a microdilution
technique with the semisynthetic high resolution (HR) medium supplemented with
glucose and asparagine but without sodium hydrogen carbonate (pH 7.0), according
to a proposal of the working group 'Clinical Mycology' of the German Speaking
Mycological Society. Fluconazole MIC values for C. albicans were between 0.125
and > or = 128 micrograms ml-1. Thus, the median of 1 microgram ml-1 showed that
the overall fluconazole susceptibility was good. As expected, Candida krusei
(seven strains) exhibited diminished in vitro susceptibility with MIC values for
fluconazole of 8 to 128 micrograms ml-1 with a median of 64 micrograms ml-1. Some
Candida kefyr strains seemed to be less susceptible against fluconazole which was
indicated by a MIC90 of 64 micrograms ml-1. Surprisingly, no Candida glabrata
isolate exhibited a MIC value greater than 16 micrograms ml-1. Other Candida
species, Trichosporon cutaneum, Geotrichum candidum and Saccharomyces cerevisiae
showed low MICs to fluconazole. In vitro susceptibility testing of itraconazole
revealed that all Candida species except C. albicans, but also Trichosporon
cutaneum, Geotrichum candidum, and Saccharomyces cerevisiae exhibited acceptable
low MIC values against itraconazole (0.03-2 micrograms ml-1). Their MIC90 values
for itraconazole were in the close range between 0.125 and 2 micrograms ml-1. MIC
values between 0.125 and 2 micrograms ml-1 were obtained, even for C. krusei
strains. On the other hand, the range of C. albicans MICs was between 0.0125 and
> or = 16 micrograms ml-1 with MIC50 and MIC90 values of 0.125 and > or = 16
micrograms ml-1, respectively, indicating that a considerable number of yeast
strains have high MICs. The comparative evaluation of different experimental
conditions revealed that there exists a marked influence both of inoculum size
and incubation time on the results of susceptibility testing. Therefore, for
routine usage 10(2) CFU ml-1 and 18-24 h incubation time for this microdilution
method with HR medium are recommended.
PMID- 10680440
TI - In vitro antifungal susceptibility of clinical isolates of Candida spp. from
hospitalized patients.
AB - A total of 122 Candida spp. strains, isolated from a group of 100 patients
hospitalized in the Santa Casa de Misericordia of Belo Horizonte were assayed for
in vitro susceptibility to amphotericin B, fluconazole, itraconazole,
ketoconazole and flucytosine using a microbroth technique proposed by the
National Committee for Clinical Laboratory Standards. In this study large
variations were observed among minimum inhibitory concentration values depending
on the species tested. The statistical analysis (Kruskal-Wallis test) showed that
itraconazole and flucytosine were the more efficient antifungal drugs for most of
species, and amphotericin B and fluconazole were the least efficient.
PMID- 10680441
TI - The influence of alcohol disinfection of nail samples in the laboratory.
AB - Samples of two hundred finger- and toenails cultured after a 70% alcohol
disinfection for 2 min were compared with non-disinfected samples cultured on a
classical way. Alcohol treatment caused a significant decrease in isolation of
yeast and moulds. Both organisms were cultivated at 25.5 and 31%, respectively,
when not treated with alcohol, whereas the isolation rate dropped to 10 and
17.5%, respectively, after alcohol treatment. Isolation of dermatophytes
decreased from 27.5 to 23.5% when alcohol disinfection was used. In conclusion,
although alcohol disinfection of nail samples in the laboratory effectively
decreases the isolation rate of unwanted contaminants on Sabouraud glucose agar
without cycloheximide, it hampers the isolation of dermatophytes and pathogenic
yeasts on cycloheximide-containing media.
PMID- 10680442
TI - Topical treatment of dermatophytosis and cutaneous candidosis with flutrimazole
1% cream: double-blind, randomized comparative trial with ketoconazole 2% cream.
AB - In a double-blind, randomized study the efficacy and tolerance of flutrimazole 1%
cream were compared with ketoconazole 2% cream, applied once daily for 4 weeks,
in 60 patients with culturally proven dermatophytosis (47 patients) or cutaneous
candidosis (13 patients). Both groups of patients and distribution of target
lesions were similar. The sum of clinical scores had an even distribution in both
groups at the end of treatment. The proportion of patients with negative
microscopy and culture after 4 weeks of treatment was 70% in the flutrimazole
group and 53% in the ketoconazole group; seven ketoconazole-treated patients
(23%) compared with two flutrimazole-treated patients (6.6%) were asymptomatic
carriers (clinically cured with positive cultures) at the end of treatment. At
the assessment 6 weeks after the end of therapy the percentages of flutrimazole-
and ketoconazole-treated patients with negative mycology were 57 and 70%,
respectively. There were one relapse (3.3%) in the ketoconazole group and four
(13.3%) in the flutrimazole group. One patient treated with ketoconazole (3%) had
a premature termination due to adverse events attributable to the medication. The
results of this study show that flutrimazole 1% cream is as effective and safe as
ketoconazole 2% cream for Candida and dermatophyte skin infections.
PMID- 10680443
TI - Epidemiology of dermatomycoses of humans in central Poland. Part IV.
Onychomycosis due to dermatophytes.
AB - The total number of dermatophytoses (7393) included 1567 (21.2%) cases of
onychomycosis. Etiological factors in descending order were: Trichophyton rubrum
(58.8%), Trichophyton mentagrophytes var. granulosum (26.2%), T. mentagrophytes
var. quinckeanum, T. mentagrophytes var. interdigitale (5.1%), Trichophyton
tonsurans (4.1%), Trichophyton violaceum (1.5%), Trichophyton spec. (1.1%). An
increase in the incidence was noted between 1994 and 1996. At present,
onychomycosis is third by incidence among all clinical forms of dermatophyte
infections of skin and skin appendages in the Lodz region.
PMID- 10680444
TI - Epidemiology of dermatomycoses of humans in central Poland. Part V. Tinea
corporis.
AB - The total number of dermatophytoses (7393) included 2204 (29.8%) cases of tinea
glabrosa. Etiological factors in descending order were: Microsporum canis
(23.5%), Trichophyton mentagrophytes var. granulosum (21.6%), Trichophyton rubrum
(17.8%), Trichophyton tonsurans (10.4%), Epidermophyton floccosum (7.7%), T.
mentagrophytes var. quinckeanum (6.0%), Microsporum gypseum (5.3%), Trichophyton
violaceum (3.7%), T. mentagrophytes var. interdigitale (2.3%), Microsporum
equinum (0.7%), Trichophyton verrucosum (0.4%), Trichophyton spec. (0.4%),
Microsporum cookei (0.14%). At present tinea glabrosa is dominant among all
clinical forms of dermatophyte infections of skin and skin appendages in the Lodz
region.
PMID- 10680445
TI - Antifungal activity of plant extracts against dermatophytes.
AB - The aqueous extracts (15 micrograms ml-1 medium) of 22 plants used in folkloric
medicine in Palestine were investigated for their antifungal activity and minimum
inhibitory concentrations (MICs) against nine isolates of Microsporum canis,
Trichophyton mentagrophytes and Trichophyton violaceum. The extract of the
different plant species reduced colony growth of the three dermatophytes by 36 to
100% compared with the control treatment. Antimycotic activity of the extract
against the three dermatophytes varied significantly (P < 0.05) between test
plants. Extracts of Capparis spinosa and Juglans regia completely prevented
growth of M. canis and T. violaceum. The most active extracts (90-100%
inhibition) were those of Anagallis arvensis, C. spinosa, J. regia, Pistacia
lentiscus and Ruta chalapensis against M. canis; Inula viscosa, J. regia and P.
lentiscus against T. mentagrophytes; and Asphodelus luteus, A. arvensis, C.
spinosa, Clematis cirrhosa, I. viscosa, J. regia, P. lentiscus, Plumbago europea,
Ruscus aculeatus, Retema raetam and Salvia fruticosa against T. violaceum. The
MICs of these most active plants ranged from 0.6 to 40 micrograms ml-1. The three
dermatophytes differed significantly with regard to their susceptibility to plant
extracts. Trichophyton violaceum was the most susceptible being completely
inhibited by 50% of the extracts followed by M. canis and T. mentagrophytes which
were completely inhibited by only 23 and 14% of the extracts, respectively.
PMID- 10680446
TI - Comments on Malassezia species from dogs and cats.
PMID- 10680447
TI - Case report. Localized pulmonary zygomycosis without pre-existing
immunocompromised status.
AB - Pulmonary zygomycosis rarely occurs without pre-existing immunocompromised
disease. A 72-year-old male was found to have a nodular shadow (3 cm x 4 cm) in
the right S8 and S9 on a chest X-ray. Right lower lobectomy was performed and
histological examination of the resected material demonstrated pulmonary
zygomycosis. Hyphae stained positively not only with Grocott-Gomori methenamine
silver staining, but also with an anti-Rhizopus oryzae polyclonal antibody.
PMID- 10680448
TI - Case reports. Invasive pulmonary aspergillosis in non-neutropenic patients
treated with liposomal amphotericin B.
AB - We report two cases of invasive pulmonary aspergillosis due to Aspergillus flavus
in one patient who with chronic nephritis and to A. fumigatus in another with
malignant lymphoma. After receiving intravenous liposomal amphotericin B therapy
for 31 and 35 days, respectively, the patients were cured and did not experience
any severe adverse effects.
PMID- 10680449
TI - Case report. Folliculitis barbae caused by Candida albicans.
AB - Folliculitis barbae candidomycetica is a very rare disease and in the scientific
literature this manifestation of candidosis is rarely described. In most cases, a
connection with predisposing factors is suspected, although in the cases cited
this connection was not frequently proved. Furthermore, in our patient who was
suffering from a folliculitis candidomycetica no predisposing factors or
illnesses were apparent. For this reason, the importance of such aetiological
factors of Candida folliculitis must be critically discussed. Effective drugs for
use in treatment are fluconazole, itraconazole and ketoconazole.
PMID- 10680450
TI - [Insulin-like growth factor-I: pathophysiologic and clinical aspects].
AB - The paper reviews the factors which affect synthesis and metabolic activity of
the insulin-like growth factor-I (IGF-I), its receptor and binding proteins as
age, nutritional state, hormonal state and liver function. Attention is also
focused on the role of IGF-I in pathogenesis of osteoporosis and neoplastic
diseases.
PMID- 10680451
TI - [Evaluation of selected HLA DRB1 gene alleles as genetic markers of type I
diabetes in the population of northeastern Poland].
AB - Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease and both
environmental and genetic factors play a role in its pathogenesis. The second
generation screen of human genome has confirmed that diabetes mellitus type 1 is
a polygenic disease. The identification of the alleles with the highest
association with IDDM in the different populations gives the opportunity for
better evaluation of the probability of IDDM development in subjects at risk
(i.e. first degree relatives of IDDM patients with autoantibodies against B
cells). The aim of the present study was to estimate the frequency of chosen HLA
DRB1 gene alleles in patients with insulin-dependent diabetes mellitus and their
first degree relatives in comparison with the healthy population in the north
eastern region of Poland. The highest predisposition to IDDM in the population of
the north-eastern region of Poland was associated with DRB1*0401 allele and
DRB1*03-DRB1*04 haplotype, while the dominant protection was connected with
DRB1*0403 and nonDRB1*03-nonDR*04 haplotype. Our study suggests that the
estimation of HLA DRB1*04 allele subtypes serves as a marker for better
identification of subjects at risk of IDDM development in the first degree
relatives of IDDM patients.
PMID- 10680452
TI - [Clinical evaluation of amino acid solution].
AB - Glutamine, a conditionally essential amino acid, is important for immune
function. It is now being formulated for incorporation in to total parenteral
nutrition (TPN). The aims of this study were to examine the effect of glutamine
administration on clinical status, body composition, protein synthesis and immune
function in critically ill patients with sepsis. Eleven patients were included
into the study. Seven of them have been on conventional TPN for 8-63 days without
significant clinical and nutritional improvement. Glutamine supplemented TPN was
implemented for 10 subsequent days. Before, during and after the study venous
blood samples were taken for the cellular immunity examination, and for the
measurement of plasma albumin, transferrin and triglycerides levels. Nitrogen
balance was calculated every day during the study. No side effects were noted.
Patients receiving amino acid solution revealed improved nitrogen balance, body
composition and body water distribution. Plasma proteins concentrations and
immunological indices significantly increased during ten days TPN with Glamin. We
confirm the beneficial effects of amino acid solution-supplemented TPN on
nitrogen balance, plasma proteins, and immune status of critically ill patients.
PMID- 10680453
TI - [Use of plasmapheresis in patients with AIDS and peripheral polyneuropathy].
AB - The plasmapheresis is procedure removal of plasma and simultaneously, together
with plasma, toxins, incorrect metabolites, antigens and immunological complexes.
In patients with HIV infection often appearance periphery polyneuropathy. This is
connected with autoantibody action on the damage of neurone. The aim of this
study was evaluation effectiveness of plasmapheresis in treatment patients with
AIDS and polyneuropathy. Seven patients with AIDS--C3 and polyneuropathy
coexistence were treatment by plasmapheresis. The symptoms of polyneuropathy
decrease in all patients. Were don't influence on immunological system and side
effect performance plasmapheresis.
PMID- 10680454
TI - [Levels of proinflammatory cytokines: IL-1, IL-6, IL-8, TNF-alpha and receptor IL
6R in Lyme borreliosis].
AB - We estimated serum concentrations of cytokines IL-1, IL-6, IL-8, TNF-alfa and IL
6R of patients with diagnosed Lyme disease treated with beta-lactam antibiotics.
Detection of proinflammatory cytokines was performed in ELISA tests. The
examination was performed before and after treatment. Comparison with control
group stated statistically significant higher concentration of IL-1 and IL-6
before and after treatment. There were no differences in concentration of TNF
alfa, IL-8 and IL-6R. Comparing concentrations of cytokines before and after
treatment there was no differences either. Lack of changes in concentration of
proinflammatory cytokines during beta-lactam therapy could be explained by too
short period of therapy or immunologic background of inflammatory process in Lyme
disease which was only initiated by spirochete Borrelia burgdorferi.
PMID- 10680455
TI - [Squamous cell carcinoma antigen for monitoring patients with head neoplasm].
AB - The authors present results of evaluation of squamous cell carcinoma antigen
(SCC) in 73 persons (35 patients with head carcinoma and 38 healthy persons as
control group). We analysed a concentration of SCC in preliminary study and in
monitoring, depending on clinical advances of tumour, mass of primary tumour and
metastases to lymph nodes. We observed high sensitivity (SE) (63%), high
specificity (SP) (97.4%) and predictive values: positive PV(+)--95.6%, negative
PV(-)--74% of SCC in preliminary study. These values changed to SE--83.3%, SP-
92.3%, PV(+) 90.9%, PV(-)--85.7% in monitoring. Our results indicate that
evaluation of SCC have high value in monitoring patients with head carcinoma.
PMID- 10680456
TI - [Clinical and histopathologic picture of lichen sclerosus treated with clobetasol
propionate].
AB - Effects of treating of the vulvar lichen scleroses by topical using of clobetasol
propionate. The period of observation was 1 year. All patients showed clinical
improvement or full regression depending on the period of disease. In all cases
histopathologic examination was performed.
PMID- 10680457
TI - [Monilethrix--rare syndrome of structural hair abnormalities].
AB - Monilethrix is a rare structural disorder of hair. Characteristic abnormalities
in the form of alternating thinning and fusiform thickening are observed in most
of hair shafts that we call beaded hair. Macroscopic estimation shows lustreless,
dry, rough, fragile hair. Trichological examination usually reveals a
considerable percentage of anagenic hair. According to our own experiences and
literature data systemic therapy (vitamins) and topical treatment (desquamative
ointments) are not effective sufficiently. Spontaneous regression of symptoms
often appears with time. Five cases of familial occurrence of monilethrix have
been presented.
PMID- 10680458
TI - [A case of hamartoma in the larynx].
AB - The authors describe a rare case of hamartoma in the larynx of a 31 years old
man. The egg sized tumor was situated in the left aryepiglottic fold filling the
lower pharyngeal space. The unfortunate location, patient disdain as well as late
diagnosis and proper management caused the histologically benign tumor to enlarge
and block the laryngeal entrance that endangering life. After initial tracheotomy
the tumor was successfully removed through the mouth.
PMID- 10680459
TI - [The role of some cytokines in the etiopathogenesis of leukemia].
AB - Some cytokines play important role in etiology and pathogenesis of leukaemia.
Most of them more stimulate than inhibit the proliferation of leukaemia cells.
PMID- 10680460
TI - [An attempt to clarify the etiopathogenesis of chronic lymphatic B-cell
leukemia].
AB - The paper presents current opinions about aetiology and pathogenesis of chronic
lymphatic B-cell leukaemia.
PMID- 10680461
TI - [A review of methods for organizing nutritional education for hospitalized
patients].
AB - Diet-related diseases are diagnosed very frequently among inpatients and result
in high mortality rate. Most commonly, the severity of illness or poor prognosis
can be reduced or diminish by change of the lifestyle or simply-eating behavior.
Across many countries there is conducted research of nutrition education
potentials. It is usually applied to patients during their staying in hospital
and after. A review of methods of nutrition education for hospitalised patients
was done. The methods can be classified into three categories: instructional,
motivational and behavioral. The effectiveness of the methods was the main
concern. There were two major ways to evaluate this effectiveness: direct
approach (laboratory or anthropometry tests) and indirect approach
(questionnaires, food diary). An advantage of nutrition education providers'
employment was discussed. Many studies show that nutrition education is an
effective method in secondary prevention of diet-related diseases. It is
promising to disseminate these kind of efforts in Poland.
PMID- 10680462
TI - [Treatment with iodine radioisotopes of benign thyroid disease].
PMID- 10680463
TI - [Hematopoietic stem cells I. Basal aspects].
AB - The knowledge on basic aspects of hematopoietic stem cells (HSC) has markedly
increased during the last decade to the extent that such cells are now routinely
employed therapeutically in order to restore hematopoiesis following
myeloablative chemotherapy and irradiation in patients with malignant disorders.
Different methods can be applied to characterize HSC. Thus, by immunophenotyping
and flow cytometry it is possible to delineate subpopulations of cells enriched
for HSC. However, since phenotypic characteristics associated with HSC do not
necessarily correlate to their developmental potential, measurements of HSC also
rely heavily upon functional in vitro and in vivo assays, which demonstrate the
presence of HSC through their ability to proliferate and differentiate in a
clonogenic fashion. In this review we describe the assays developed to
characterize and quantitate immature HSC, which form the basis for their clinical
application.
PMID- 10680464
TI - [Hematopoietic stem cells II. Diagnostic and therapeutic aspects].
AB - Characterization and isolation of haematopoietic stem cells (HSC) have resulted
in their clinical application in patients with malignant disorders and--through
gene therapeutic initiatives--also in the treatment of inherited diseases.
Autologous stem cell transplantation (ASCT), which was introduced because of the
high number of relapses in cancer patients in remission, involves dose
intensification (conditioning), which induces myeloablation. In this setting,
reinfusion of HSC is performed to restore haematopoiesis. Flow cytometric
determination of CD34+ cells and clonogenic assays for committed myeloid HSC (CFU
GM) are vehicles for quality control of the harvested HSC material and are
integrated into the ASCT programs. Moreover, harvest of HSC and purification of
CD34+ cells enables new treatment options such as removal of cancer cells from
grafts, optimization of gene transduction as well as ex vivo expansion of HSC
before reinfusion. In conclusion, the expanding insights into HSC in the 1990's
have already been translated into valuable diagnostic and therapeutic modalities.
PMID- 10680465
TI - [The connection between the intima-media-complex and atherosclerosis].
AB - In atherosclerosis several years will pass from development of the first fatty
streaks to the first clinical event. In epidemiological investigations of
atherosclerosis it is therefore desirable to have a valid method for detecting
atherosclerosis in the earliest stages, which is harmless and can be performed
repeatedly without risks in the healthy volunteer. Measuring the intima-media
complex (IMT) using ultrasound constitutes such a method. Results from
international research are reviewed and it is concluded that the method should be
applied in Denmark in atherosclerosis research.
PMID- 10680466
TI - [Azathioprine treatment of Crohn disease].
AB - Azathioprine/6MP (AZA/6MP) is effective in long-term treatment (> 3 months) of
Crohn's disease and superior to other established medical treatments. The optimal
dose remains to be defined. So far, effect has been demonstrated with 2-2.5 mg
azathioprine/kg/day, but not with 1 mg/kg/day. A disease controlling effect has
been demonstrated during up to four years of continuous treatment, after which
data remains to be established. As part of remission-inducing combination therapy
the effect of AZA/6MP can not be detected until two-three months after treatment
start. High dose intravenous AZA/6MP administration does not shorten this
interval. Reversible dose dependent side effects may require dose reduction or
termination of treatment. Reversible dose independent side effects exclude
further or repeated treatment. Some 10-15% stop treatment due to side effects.
There is no increased death rate due to cancer in AZA/6MP treated Crohn patients.
When giving the above full dose of AZA/6MP, monthly blood tests are recommended
for the entire treatment period, more often during the first three months.
PMID- 10680467
TI - [Radioiodine therapy of benign thyroid disease in Denmark].
AB - The aim of the study was to evaluate differences in the use of radioactive iodine
in the treatment of benign thyroid disease in Denmark. A questionnaire was
distributed to all departments in Denmark which administer radioiodine in the
treatment of benign thyroid disease (n = 20). Radioiodine is used for patients
with toxic nodular goitre and for patients with relapse of toxic diffuse goitre.
Four departments did not use radioiodine for volume reduction in non-toxic
goitre. Patient informations included very different recommendations regarding
cautions in relation to radioiodine treatment. Radioiodine is widely used in the
treatment of benign thyroid disease. We recommend a national standardization of
the cautions in relation to radioiodine treatment.
PMID- 10680468
TI - [Nitric oxide inhalation therapy in patients with acute respiratory distress
syndrome. A retrospective analysis].
AB - Acute lung injury in the form of the acute respiratory distress syndrome (ARDS)
continues to carry a high mortality. Recently, inhaled nitric oxide (NO) has been
used in ARDS patients with severe hypoxaemia. We present a retrospective analysis
concerning 33 ARDS patients treated with inhaled NO during a period of four years
from 1994 to 1998. Patients were young, mean 43 years, had poor oxygenation
(PaO2/FiO2 index 67 mmHG) and a lung injury score above 2.5. Eighty-two percent
responded immediately to NO, 9% at a later challenge and 9% were non-responders.
Mortality for the whole group was 67% and to be expected considering the severity
of disease. For the group of patients with ARDS as a complication of pneumonia
mortality was only 40%. In one patient therapy had to be stopped due to formation
of NO2 even at very low concentrations of inhaled NO. We conclude that inhaled NO
is effective in improving oxygenation in patients with ARDS. The study does not
allow us to conclude anything about mortality, which was probably unchanged by
this novel therapy.
PMID- 10680469
TI - [Nitrogen oxide inhalation in critically ill patients].
AB - Inhaled nitric oxide (iNO) has been extensively used in the treatment of severe
hypoxaemic respiratory failure and/or pulmonary hypertension. Although the
majority of studies have almost consistently demonstrated a beneficial effect on
oxygenation and a reduction in pulmonary artery pressures, none of the randomised
trials have reported a reduced mortality using iNO on patients with severe
respiratory failure. In neonates with severe respiratory failure and pulmonary
hypertension, however, iNO can reduce the need of extracorporal membrane
oxygenation. Prior to using iNO on adult patients we suggest other measures to be
taken (i.e. optimising ventilator settings, ventilation in prone position).
PMID- 10680470
TI - [Prognosis after primary acute myocardial infarction].
AB - Results from many clinical trials have changed treatment strategies, but due to
considerable selection caused by extensive inclusion- and exclusion criteria the
results are only valid for smaller groups, while the majority of the patients
still suffer from high mortality with conservative treatment. We have during
eight years followed 933 patients with first myocardial infarction and found that
the group who tolerated treatment with thrombolytic agents had a lower mortality
than the rest. On the other hand, infarct patients are generally old, often with
concomitant chronic diseases which affect mortality, and this in combination with
heart-failure and cardiac arrhythmias determines outcome. Better prophylactic and
treatment measures are needed to improve survival of ischaemic heart disease.
PMID- 10680471
TI - [Staphylococcus aureus endocarditis in Denmark 1982-1991. Clinical picture,
complications and antibiotic therapy in non-drug addicts].
AB - The central S. aureus surveillance in Denmark made it possible to analyze the
clinical features of S. aureus endocarditis in a nation-wide population of non
drug addicts. Almost all cases of bacteraemia with S. aureus are reported to the
Staphylococcus laboratory, Copenhagen. The medical records were reviewed in cases
from 1982 to 1991 in which the diagnosis of endocarditis was reported or
suspected. Two hundred and sixty patients fulfilled the diagnostic criteria. In
83 patients the diagnosis of endocarditis was not suspected clinically. The
overall mortality rate among those patients whose disease was diagnosed
clinically was 46% and significantly associated with late congestive heart
failure, age and involvement of the central nervous system. A more frequent use
of echocardiography as a screening method seems essential to improve the
prognosis of patients with S. aureus endocarditis. Involvement of the CNS
constitutes a relative indication for early valve replacement.
PMID- 10680472
TI - [Diet, cancer and health--a population study and establishment of a biological
bank in Denmark].
AB - In order to test hypotheses on diet and the risk of cancer, a prospective cohort
study was established. A total of 57,055 persons living in Copenhagen and Aarhus,
between 50 and 65 years of age, visited a study clinic between December 1993 and
May 1997. The participants provided questionnaire data on diet and lifestyle.
Furthermore, anthropometric measurements, blood pressure and biological material
were collected. All participants will be followed by linkage to health registries
including the Cancer Registry and by self-administered follow-up questionnaires.
The purpose of this publication is to describe the data-base, which will be
available for research in the years to come including the results of the first
two years of follow-up.
PMID- 10680473
TI - [Perioperative administration of recombinant human erythropoietin in colorectal
cancer surgery. A prospective, randomized, double-blind placebo controlled
study].
AB - One hundred patients scheduled for elective colo-rectal cancer surgery, and with
a preoperative haemoglobin level < or = 8.5 mmol/l were included. Eighty-one
patients could be evaluated. Thirty-eight patients received r-HuEPO in a dose of
300 IU/kg body weight on day four before surgery and 150 IU/kg, daily, for the
following seven days, and 43 patients received placebo. In addition, all patients
received daily doses of 200 mg iron, orally, for four days before surgery. On the
day of surgery and until discharge the haemoglobin concentration was
significantly higher in the erythropoietin group compared to the placebo group.
The number of blood transfusions given was significantly lower in the
erythropoietin group with a mean of 0.3 units per patient (0-6) compared to 1.6
units (0-9) in the control group (p < 0.05). The clinical implications of these
findings has yet to be assessed.
PMID- 10680474
TI - [Mycobacterium avium complex infection in a patient with idiopathic CD4+ T
lymphocytopenia].
AB - Primary cutaneous infections with MAC are extremely rare. We report a case of
primary cutaneous infection with MAC, in a 69 year-old HIV-negative male.
Idiopathic CD4+ T-lymphocytopenia was diagnosed.
PMID- 10680475
TI - [Rupture of an isolated iliac aneurysm].
AB - Isolated iliac artery aneurysm threatening to rupture is a rare condition with a
poor prognosis if not dealt with by the physician in a brisk and effective
manner. Symptoms from an iliac aneurysm can masquerade as a range of symptoms
from neighbouring organs or be almost asymptomatic before rupturing. A case of a
81 year old man, with symptoms of dizziness, fatigue and light lower abdominal
pain, who developed sudden cardiovascular collapse, is presented.
PMID- 10680476
TI - [Bilateral rupture of the quadriceps tendon in a healthy individual].
AB - A case of bilateral rupture of the quadriceps tendons in a 59 year-old man
without any known systemic disease is presented. The ruptures occurred while he
was descending a staircase, after which he fell. Repetitive microtrauma was
suspected as the etiological reason for rupture.
PMID- 10680477
TI - [Picture of the month. Hepatopulmonary syndrome].
PMID- 10680478
TI - [Leptin in arterial hypertension].
PMID- 10680479
TI - [From scientific recognition to practical clinical guidelines].
PMID- 10680480
TI - [Innate mechanisms during pregnancy].
PMID- 10680481
TI - [Demand and offer of coronary angiography in Denmark].
PMID- 10680482
TI - [Polyneuropathy in critically ill patients].
PMID- 10680483
TI - [A method of unilateral operation for early cleft palate repair].
AB - OBJECTIVE: This paper presents a new method for cleft palate repair. METHOD: Six
changes have been made to the conventional procedures. After all of these six
changes have been carried out on one side of the palate, the operated side
becomes completely relaxed. It can be moved both posteriorly and medially to
lengthen the side of the palate and to contact with the cleft margin of the non
operated side without tension. Obviously, there is no need to perform the same
surgical maneuvers on the other side again. The cleft is then closed by layers.
RESULT: Totally 151 cases of unilateral and bilateral cleft palate have been
repaired with this method. The age of these patients ranged from 4 months to 5
years. Postoperatively, there was neither one death nor one dehiscence. All of
the baby patients who received treatment before they began to speak had good
quality of speech or near normal speech function. CONCLUSION: In the unilateral
operation, the surgical trauma, blood loss and time required for the operation
are all less than that of conventional procedures which operate on both sides. It
is a safer method for early cleft palate repair.
PMID- 10680484
TI - [Cleft palate repair with bilateral buccal musculomucosal flaps].
AB - OBJECTIVE: A method for cleft palate repair was used for the purpose of
diminishing surgical interference with maxillary growth. METHOD: Sixteen cases of
cleft palate were repaired with bilateral buccal musculomucosal flaps. RESULT:
The operation results in all cases were satisfactory. CONCLUSION: It is
concluded: 1. The method does not traumatize the periosteum of the hard palate,
thus alleviating postoperative maxillary deformity; 2. The buccal musculomucosal
flap is generally long enough to reach across the incisive foramen and maintain
good blood circulation; 3. The method benefits reconstruction of the levator
sling and facilitates velopharyngeal closure.
PMID- 10680485
TI - [Correction of nasal septal deformities of the unilateral cleft lip].
AB - OBJECTIVE: Septal deformities are very common in patients with unilateral cleft
lip nose. The deformities are influential on the morphology of the external nose
and respiratory function. The study was conducted to correct the septal
deformities. METHOD: The operation procedure includes correction and replacement
of the deviated septum to the middle position; correction of the displaced alar
cartilage with the suspension method and correction of soft tissue deformities of
the nose and lip. Twelve patients were treated with this method from 1994 to
1995. RESULT: Postoperative follow-up of 3-12 months demonstrated satisfactory
results. CONCLUSION: Correction of septal deformities plays a very important role
in the operation for the unilateral cleft lip nose.
PMID- 10680486
TI - [Anatomic study of the musculus depressor septi nasi in unilateral cleft lip
nasal deformity].
AB - OBJECTIVE: This study was to investigate the nasal musculature and its
relationship with the deformities of the unilateral cleft lip nose. METHOD: The
anatomic and histological examination and comparison of the musculus depressor
septi nasi (MDSN) were performed in 33 normal cadavers and 30 patients with
unilateral cleft lip undergoing the operation for secondary nasal deformities.
RESULT: It was found that the MDSN in the cleft side of a unilateral cleft lip
nose is lacking. CONCLUSION: Because of the anatomic deficiency on the cleft
side, the function of the normal side is pathologically increased. The functional
imbalance between the normal and abnormal side may bring about dislocation and
malformation of the base of nasal columella as well as the septal structures.
PMID- 10680487
TI - [The effect of tangential excision on the local IL-8 release and wound
inflammatory response in deep-partial thickness burn].
AB - OBJECTIVE: The aim of this study is to investigate the effect of tangential
excision on the local IL-8 release and wound inflammatory response. METHODS: The
tissue specimens, which were taken from 7 patients with deep partial thickness
burn before and after operation, were both cultured and histopathologically
examined. The level of IL-8 in the culture medium was assayed, meanwhile local
inflammatory response of tissue samples was evaluated. RESULTS: The result showed
that the level of IL-8 is much lower in the postoperation wounds, while in the
non-operation wounds the neutrophil infiltration was marked, with enlargement in
necrotic area and disappearance of skin appendages. CONCLUSION: The findings
suggested that tangential excision could reduce the local production of IL-8 and
decrease local inflammatory response, which is helpful to prevent the progressive
necrosis of burn wound.
PMID- 10680489
TI - [Mechanisms of early gastro-intestinal ischemia after burn: hemodynamic and
hemorrheologic features].
AB - OBJECTIVE: To study the mechanisms of early gastro-intestinal ischemia developed
in acute burn period and its relationships with hemodynamic and hemorrheologic
changes. METHODS: Twelve pigs were randomly allocated into two groups: group C, a
sham group that was subjected to all surgical procedures except burn; group B,
30% TBSA cutaneous thermal injury, and was resuscitated with Parkland formula one
hour after burn. RESULTS: MAP remained stable after burn, but RAP, MPAP, PAWP and
CI decreased significantly to the lowest level 4-8 hours after burn, and
recovered after resuscitation 24 hours postburn. Intramucosal pH declined
immediately (1 hour after burn) and remained abnormal throughout observation
period. Portal venous blood flow demonstrated similar changes as pHi, and
correlated well with intestinal pHi. Whole blood viscosity and plasma viscosity
in portal venous blood elevated obviously after burn. CONCLUSIONS: 1. GI ischemia
occurred early and recovered slowly during burn shock phase with conventional
resuscitation regime. 2. GI ischemia correlated significantly with portal venous
blood flow, but did not with systemic hemodynamic variables. 3. Hemorheologic
changes in portal venous blood may exaggerate ischemia injuries.
PMID- 10680488
TI - [The influence of adhesion molecules expression to neutrophil aggregation in
liver after severe burns].
AB - OBJECTIVE: To elucidate the mechanism of neutrophil aggregation in the liver and
the influence of the expression of adhesion molecules after severe burns during
early postburn phase, and to explore simultaneously the mechanism of liver damage
after severe burns. METHODS: 1. The morphology of the liver and the activation of
MPO were observed. 2. The human hepatocytes and hepatic sinusoidal endothelial
cells (HSECs) were isolated and cultured, the flow cytometry and micropipette
aspiration system were used to observe dynamically the change in intercellular
adhesive force between neutrophils and hepatocytes under the influence of burn
patient sera. Also the changes in the expression of P-selectin and ICAM-1 on the
hepatocytes and HSECs under the influence of burn patient sera were studied.
RESULTS: 1. MPO activation was significantly higher than that in the control
group, and reached its peak at 6 hours. Three pieces of liver tissue at 6, 12, 24
hours were examined, and it was found that the Disse's spaces were wide and
filled with a great number of PMNs. 2. A constitutive expression of P-selectin
and ICAM-1 was found in normal hepatic sinusoidal endothelial cells but not in
normal hepatocytes. Under the influence of burn patient sera, the expression of P
selectin increased significantly at 1 hour (P < 0.01) in hepatic sinusoidal
endothelial cells but not in hepatocytes, and the expression of ICAM-1 increased
significantly at 1 and 2 hour (P < 0.01) in hepatocytes and hepatic sinusoidal
endothelial cells. 3. In the presence of burn patient sera, the intercellular
adhesive force between neutrophils and hepatocytes reached its peak level at 2
hour after co- cultivation and declined thereafter due to the aggravation of
hepatocytic injury. After using ICAM-1 Mab in cultured hepatocytes, the adhesive
force reduced significantly. CONCLUSION: Neutrophil aggregation in the liver was
confirmed after severe burns during early postburn phase. The expression of P
selectin and ICAM-1 on the hepatocytes and HSECs played key roles to neutrophil
aggregation in liver after severe burns during early postburn phase, inducing the
participation of neutrophils in hepatocyte injury.
PMID- 10680490
TI - [Relationship between plasma D(-)-lactate levels and acute intestinal injury in
rats following ischemia-reperfusion].
AB - OBJECTIVE: To determine the kinetics of plasma D(-)-lactate levels in both portal
and systemic circulations, and to examine whether elevated plasma D(-)-lactate
would correlate to intestinal injury in rats subjected to acute intestinal
ischemia-reperfusion. METHODS: Anesthetized rats underwent 75 minutes of superior
mesenteric artery occlusion followed by 6 hours of reperfusion. Plasma D(-)
lactate levels were measured by an enzymatic spectrophotometric assay. RESULTS:
It showed that intestinal ischemia for 75 minutes resulted in a significant
elevation in D(-)-lactate levels in portal vein blood compared to baseline values
(P < 0.05). Plasma D(-)-lactate levels had a tendency to further increase after
reperfusion up to 6 hours. Similar alterations in D(-)-lactate were also found in
systemic circulation, there were no significant differences between the portal
and systemic circulation at any time point. Moreover, the histopathological
evaluation scores were significantly correlated to the portal D(-)-lactate levels
in animals at various time points (r = 0.415, P < 0.01). In addition, a
remarkable rise of endotoxin concentration within portal vein was already found
at the end of 75-minute ischemia (P < 0.05), reaching a peak at 2 hours post
reperfusion. CONCLUSION: These data suggest that acute intestinal ischemia is
associated with failure of mucosal barrier resulting in increased plasma D(-)
lactate levels in both portal and systemic blood. The subsequent reperfusion
might cause further increase in D(-)-lactate levels, which correlated to the
histopathological alterations. Plasma D(-)-lactate may be a useful marker of
intestinal injury following both ischemia and reperfusion insults.
PMID- 10680491
TI - [A new burn wound covering-fibroin membrane].
AB - OBJECTIVE: This study was aimed at determining the physical and biological
properties of fibroin membrane and evaluating its clinical effects. METHODS: 1.
The physical and biological properties of fibroin membrane and partial thickness
porcine skin were determined with various instruments. The determinations
included water ratio, tensile strength, flexibility, water permeability, adhesive
force and so on. 2. CLINICAL OBSERVATION: Two wounds with same depth in the same
patient were selected. One was covered by fibroin membrane. The other one was
treated with 1% SD-Ag cream. The changes in these wounds were observed and
compared. RESULTS: This membrane had nearly same physical and biological
properties compared with partial thickness porcine skin. It had no toxicity,
irritation, and antigenicity. It possessed certain amount of water permeability
and could adhere to the wound. Because of its good transparency, any change in
underlying wound could be directly observed. It was helpful not only in local
therapy but also in study of wound healing. CLINICAL OBSERVATIONs showed that
this membrane had good protecting effect to wound. Its application could
obviously relieve pain of wound and the healing time was 3-5 days ahead than that
of the control wound. CONCLUSION: This membrane was an ideal wound covering and
was worth being popularized.
PMID- 10680492
TI - [The influence of different concentrations of hydrofluoric acid on blood calcium
level in rats].
AB - OBJECTIVE: To evaluate the effects of different concentration of hydrofluoric
acid (HF) on local skin and calcium level of serum. METHODS: SD rats were divided
into two groups which were wounded by 20% and 40% percent of HF respectively.
Samples of blood and wound tissue were harvested at different postburn time for
the analysis of the calcium level of the serum and histological study. RESULTS:
It was found that twenty percent of HF was enough to cause a skin damage, and
might bring about fatal hypocalcemia after a prolonged contact. High
concentration of HF (40%) could cause deep tissue necrosis within a short time,
and result in a fatal hypocalcemia within 24 hour even in the case of a small
area injury. CONCLUSION: It is important to treat the patient with HF injury as
early as possible. Sufficient calcium must be applied guided by laboratory study
in order to prevent the fatal hypocalcemia.
PMID- 10680493
TI - [The effect of growth hormone on wound healing rate in adult burns].
AB - OBJECTIVE: To determine the wound healing effect of rHGH in adult burn patients.
METHODS: 16 patients with burn wounds covering over 60% of total body surface
(TBSA) were enrolled in this placebo controlled prospective study. They were
comparable in nutrient intake, TBSA, and full thickness burn area. rHGH group
patients were given rHGH subcutaneously in the dose of 0.3u.Kg-1 at 8 am each
morning for 10 days beginning from POD 1. The control group patients were given
normal saline as placebo. All the patients received scar excision within 4 days
postburn, and the excision wounds were covered with autologous skin pulp
grafting. Serum amino acid profile was analyzed at day 1 and day 20 post burn.
Healing time of burn wound area and donor site was recorded. Wound healing rate
was assessed at day 30 after day. RESULTS: 1. The healing time of autologous skin
pulp grafting and donor site, and the length of hospital stay were significantly
shorter in GH group patients than control group. 2. The amino acid profile showed
no difference between two groups at day 1 and was significantly better in GH
group at day 20. CONCLUSION: rHGH could enhance the wound healing rate, improve
amino acid profile, and reduce the length of hospital stay of severe burn
patients.
PMID- 10680494
TI - [Experimental study on denervated skeletal muscle autotransplantation in the
rhesus monkey].
AB - OBJECTIVE: This study was to provide a scientific basis for clinical application
of denervated muscle transplantation. METHODS: A rhesus monkey was used in this
experiment. The denervated extensor digitorum brevis (EDB) and the extensor
hallucis brevis (EHB) of the rhesus monkey were autotransplanted in the
sacrospinal muscle, and they were biopsied at intervals and stained with HE,
Bielshowsky and enzyme. The specimen were examined with light and electro
microscope. RESULTS: The metabolism of the denervated muscle was lower than the
normal. There was muscle regeneration and growing nerve fibers in the graft 12
weeks after transplantation. CONCLUSION: Denervated muscle can regenerate in
oxygen-deficient environment. If the denervated muscle is in contact with normal
muscle, the nerve of the recipient muscle will grow into the graft.
PMID- 10680495
TI - [A study on pearl fat transplantation--concentration of basic fibroblast growth
factor (bFGF) and carrier of sustained delivery selected by orthogonal design].
AB - OBJECTIVE: The experiment was designed to solve the problem that free fat
transplantation survived at low percentage. METHODS: Based on physiochemical and
biological characteristics of bFGF, fibrinogen was used as its carrier of
sustained delivery. We applied bFGF and fibrinogen in pearl adipose
transplantation. Different concentrations of bFGF and fibrinogen were used. The
relation between the concentration of bFGF and fibrinogen and their effects on
fat graft maintenance were observed. RESULTS: At three months after
transplantation, the weight of the fat graft varied from 98% to 225%. The latter
was approximately consistent with synchronous increase of the body weight of the
animal. Weight increase of the graft was closely related to the concentration of
bFGF and the sustained delivery carrier. When bFGF in the concentration of 4000
U/10 microliters and fibrinogen of 1000 mg% were applied, the fat graft obtained
the greatest weight increase. Histologically, the structure of the transplanted
fat was normal with fibrotic envelope and mature adipocytes. CONCLUSION: bFGF
with fibrinogen as its carrier of sustained delivery favors the survival of fat
graft and weight increase. The effects of bFGF and fibrinogen depend on their
concentration.
PMID- 10680496
TI - [An experimental study on promoting reconstruction of microcirculation of the
ischemic skin flap with basic fibroblast growth factor].
AB - OBJECTIVE: This study was to determine whether the basic fibroblast growth factor
(bFGF) could promote reconstruction of microcirculation in the ischemic portion
of a random skin flap. METHODS: Five methods were used in the experiment:
measurement of the survival area of the skin flap; light and electron microscopic
studies; immunohistochemical observation of the endothelial cell and microvessel
image analysis technology (IAT). RESULT: The survival area and microvessels in
the skin flap were significantly increased in the treated group. The results
indicate that bFGF can stimulate the proliferation and differentiation of
endothelial cells in vivo and promote the microcirculation of the ischemic flap.
CONCLUSION: bFGF could promote reconstruction of microcirculation of the ischemic
skin flap.
PMID- 10680497
TI - [Application of the free parascapular flap in children].
AB - OBJECTIVE: To improve surgical results we have applied the free parascapular flap
in children for facial or cervical burn scar contracture. METHOD: Eight children
aged from 6 to 9 years received free flap transfer. Based on the defect and the
distribution of the cutaneous branches of the circumflex scapular vessels, the
flap was designed with its size ranging from 15 cm x 8 cm to 22 cm x 6.5 cm.
RESULT: Free flap transferring with microvascular anastomosis was successful in
all cases. The average operation time was 5 hours with average blood loss being
about 100 ml. CONCLUSION: Free flap transplantation is safe and beneficial in
children when the technique and skill of microsurgery and plastic and
reconstructive surgery are mastered and intraoperative blood loss is controlled
under 1% of the total blood volume. The vertically oriented parascapular flap can
not only provide proper tissue for reconstraction but also minimise the donor
site morbidity.
PMID- 10680498
TI - [Surgical treatment of excessive hyperplasia symptom of skin keratosis at the
limb ends].
AB - OBJECTIVE: We introduce the experience of treating 10 cases with excessive
hyperplasia of skin keratosis at the limb end. There were 9 cases of palmar and
plantar keratosis and 1 case of epidermodysplasia verruciformis. METHOD: All
cases received the operation of lesion excision and skin grafting except 2 cases
who received skin flap for defect covering after lesion excision because of deep
tissue exposure and postradiation ulcer. RESULT: The operative effects were
satisfactory after 8 years of follow-up. No recurrence was found in all cases and
all patients resumed normal activity. CONCLUSION: The effect of the skin flap is
better than skin graft at the plantar area. Because of lack of fibrous septum in
the subcutaneous tissue, the flap, often moving during walking, is liable to
trauma and ulceration. The operation area must be well protected.
PMID- 10680499
TI - [A study of photographic standardization in rhinoplasty].
AB - OBJECTIVE: A method of photographic standardization for rhinoplasty is presented.
METHOD: To delineate the nose objectively before and after rhinoplasty, we
designed a method to standardize picturing by using the points and lines in the
face and camera in nasal photography. RESULT: With the help of anatomic points in
the face and lines in the camera, we can maintain the camera at a constant
position to the face. In this way, the nasal picture is more comparable and
instructive. CONCLUSION: This method has been proved to be helpful in
rhinoplasty.
PMID- 10680501
TI - [Application and characteristics of biomaterials commonly used in plastic surgery
-current status and prospects].
PMID- 10680500
TI - [Progress in the study of wound dressing].
PMID- 10680502
TI - [Scopes and applications of LeFort III advancement osteotomy].
AB - In order to correct craniofacial retrusion and malocculusion caused by Crouzon
syndrome, we employed LeFort III advancement osteotomies in 21 cases in last 10
years. The differences between craniofacial appearances and cephalometric
analyses pre- and postoperatively showed that good results were achieved in all
cases. No severe complications in these series were found.
PMID- 10680503
TI - [The primarily study on the correlation between the cephalometric characteristics
and the results of ploysomnography].
AB - A study on correlation between temporomandibular joint ankylosis and Obstructive
Sleep Apnea Syndrome (OSAS) was conducted. The statistic results demonstrate that
there is significant correlation between (TA + SPA)/OPA and AI, and there is
negative correlation between PAS and AI, (TA + SPA)/OPA and SaO2min by
correlation and step regression between the cephalometric analysis and
polysomnogram of fourteen cases of OSAS patients.
PMID- 10680504
TI - [A positioning device for oral paralleling technique].
AB - OBJECTIVE: To design a reliable method for standardized paralelling dental
projection, for comparison of the tiny variations of alveolar bone during the
treatment of the periodontal disease. METHODS AND MATERIAL: Periapical
radiographs in 29 pairs of films with this device and 14 pairs of films with
traditional method on dried skulls were comparatively analysed by digital
subtraction. Standard deviations and angle variations of subtracted image were
studied comparatively between this method and traditional paralleling technique.
RESULTS: Significant difference of reproducibility between two groups was showed.
The reproducibility of the successive pictures was apparently increased when
projected with positioning device.
PMID- 10680505
TI - [Quantitative studies of oncogene ras P21 and P53 gene protein expression in the
benign and malignant pleomorphic adenomas of salivary gland].
AB - The oncogene ras P21 and P53 gene protein expression in the benign and malignant
pleomorphic adenomas of salivary gland were quantitatively studied by flow
cytometry and cellular immunofluorescence staining technique. The results showed
that the ras P21 expression was found in 78% and 100% of the benign and malignant
pleomorphic adenoma, respectively. The P53 protein was detected in 81% and 100%
of the benign and malignant pleomorphic adenoma, respectively. The ras P21 and
P53 protein were negative in the normal parotid tissue. The obvious different
statistical significances of the fluorescence indexes (FI) in ras P21 and P53
expression were found between the benign and malignant pleomorphic adenoma (P <
0.001, respectively) as well as between the normal parotid tissue and the benign
pleomorphic adenoma (P < 0.001, respectively). These results indicate that
activation of ras oncogene and the mutation of P53 gene may play important roles
in the tumourigenesis and the malignant transformation of the pleomorphic
adenoma.
PMID- 10680506
TI - [The effect of artificial traumatic occlusion on the pulp and periodontium in rat
molars].
AB - In order to study relationship between the period of occlusal trauma and pulpal
and periodontal tissues, 44 rats were used in experimental occlusal trauma. The
pulpal and periodontal tissues of rat molars were observed by histological
examination and micrographic examination. The results showed that the damage of
pulp became more serious as time went on, but periodontium appeared adaptive
changes. The same changing area in periodontal tissues were observed between
histological section and micrographic film. The results provide experimental
evidences for the pathology and pathogeny of pulpitis and perioapical
periodontitis caused by occlusal trauma.
PMID- 10680508
TI - [Anatomy of the cartilages of the nose with secondary deformity associated with
unilateral cleft lip].
AB - To explore the influence of displacement and hypoplasia of nasal cartilages to
cleft lip nose, 38 patients with secondary cleft lip nasal deformity were
randomly chosen. Measurement of length and width of the nasal cartilages was
made, and places of them were inspected. The displacement of the cartilages was
found in each nose, and hypoplasia of cartilages was in those noses whose
deformities were more severe. The conclusion is that both displacement and
hypoplasia of nasal cartilages are causing factors of nasal deformity.
PMID- 10680509
TI - [Subperiosteal implantation of block coral on the rabbit cavarial bone].
AB - The aim of this study was to evaluate osteoconductive effect of coral implanted
on surface of the cortical bone. The 2 mm thick block corals were implanted on
the surface of one side of rabbits cavarial bone, the another side were used as
blank control. The specimen was examined by light microscopy, histometry and
scanning electron microscopy at 2, 4, 8, 12 weeks after operation respectively.
The results show that the new bone growth into the pore of the coral at 2 weeks
after implantation. The coral was progressively absorbed and replaced by new
bone. Up to 12 weeks, most of the coral was absorbed and newly formed bone had
been remodeled. The reconstructed height of new bone in coral group was
significantly higher than that of blank control and lower than the thickness of
block coral. The study demonstrated good osteoconductive property of coral
implanted on surface of cortical bone.
PMID- 10680507
TI - [CT examination and diagnosis of oral and maxillofacial tumors invading the
pterygopalatine space].
AB - CT findings in 33 cases (proven histopathologically) suffered from oral and
maxillofacial tumors affecting the pterygopalatine space were retrospectively
analyzed. The authors conclude that the main CT manifestations of this space
involvement by tumors can be depicted as a soft tissue mass occupancy and the
wall structures destruction. Tumors occurring in different locations of oral and
maxillofacial areas have different features of CT appearances. In addition, the
primary tumor of this space is probed from histogenesis and CT findings, and its
diagnostic criteria are discussed. As a modality of imaging, CT has an important
role for assessing the lesions of this fossa.
PMID- 10680510
TI - [A preliminary report of histological study on TMJ reconstruction with autogenous
costochondral graft].
AB - To study histologically the biological behaviour of the grafts and the reactions
in the receipt area after reconstruction of temporomandibular joint (TMJ), we
have reconstructed experimentally removed TMJs on purebred juvenile pigs by
transplanting autogenous costo-chondral grafts. The findings of continuously
survey of histologic changes in the receipt areas and the grafts showed that
autogenous grafts healed well with the surrounding soft tissues, and induced the
mesenchymal-like cells from the receipt region, rather than the periosteal cells
which might be left, to differentiate and ossify both within and at the surface
of them, and they themselves were gradually replaced by the new-formed bone; and
that active osteogenesis could also be seen within the thick tissues far from the
graft, which could not be the result of graft's induction. It may be concluded
that the new bone, both from the induction of the graft which acts as a framework
and somehow from the outside tissues, reconstructs the new condyle and determines
the postsurgical growth of the mandible.
PMID- 10680511
TI - [A quantitative study of microvascular density and proliferating cell ratio in
buccal mucosa squamous cell carcinoma].
AB - By the ABC enzyme labelling method we studied the microvascular density and
proliferating cell ratio in buccal mucosa squamous cell carcinoma (BMSCC) and in
normal buccal tissues quantitatively. These two parameters in BMSCC are 208% and
335% (P < 0.05) respectively which are distinctly higher than those of the normal
buccal tissues, indicating malignant features of the carcinoma. The distribution
of proliferating cells, corresponds to the area where the microvascular density
is high, mainly in the periphery and basal parts of cancer nests. There is a
dependent relationship between them, showing a linear positive correlation
statistically. The results confirm that angiogenesis and cancer cell
proliferation promote each other. They are two important indexes of the local
biological behavior of BMSCC and are very important to predict the malignant
potential and to evaluate therapeutic effect for BMSCC.
PMID- 10680512
TI - [Characteristics of lip-mouth region in smiling position from 80 adults with
acceptable faces and individual normal occlusions].
AB - The Characteristics of Lip-mouth region including the soft and hard tissues in
smiling position with frontal fixed position photographic computered analysis was
studied. The examples were 80 adults (40 males and 40 females) with acceptable
faces and individual normal occlusions. The age was between 17-25 years of age.
The method adopting maximum smiling position to study the lip-mouth region is
scientific, and the maximum smile line could be divided into three categories:
low smile line-a-counted for 16.25% of the total samples; average smile line-
68.75%; high smile line--15%.
PMID- 10680513
TI - [Immunohistochemical and quantitative analysis of expression of basement membrane
in squamous cell carcinoma of the oral cavity].
AB - Fifty seven cases of oral squamous cell carcinoma (OSCC) were studied by
immunohistochemical ABC method using type IV collagen and laminin antibodies and
computer image analysis system to investigate the expression of basement membrane
and its relation to clinicopathologic characteristics of the OSCC. The results
demonstrated that: 1. in OSCC there were defects basement membrane in continuity
of varying extents to complete loss of; 2. there was no correlation between the
loss of basement membrane and tumor clinical stage (P > 0.05) by computer image
analysis, while there was a highly significant correlation between the loss of
basement membrane and histologic grading (P > 0.05). The well-differentiated
tumor was associated with a low frequency of basement membrane loss. Therefore,
the expression of basement membrane may be a useful parameter to evaluate tumor
histologic differentiation.
PMID- 10680514
TI - [Histopathological study on traumatic facial nerve injury in the rabbits].
AB - Six patterns of injuries (exposure, compression, crush, stretch, division and
post-division anastomosis) were analysed in 136 facial nerve buccal branches of
68 rabbits in order to establish the experimental model for study of traumatic
facial nerve injury. Changes of histopathology at definite time were studied. The
results showed that: exposure can create degree I injury; compression, stretch
and crush can create degree II-III injury; the prognosis in anastomosis group was
obviously better than unanastomosis group. In moderate to serious injuries,
changes of histopathology and ENoG were synchronized, but were not so in mild and
later stage of serious injury. The 15th day postinjury was the best time of
estimating the facial nerve function clinically. The area of injury would
obviously influence the mylin lesion, while the quality and degree of injury
would obviously influence the axonal lesion.
PMID- 10680515
TI - [Expression of transforming growth factor beta 1 in keratinocytes of oral
submucous fibrosis tissue].
AB - To explore significance of transforming growth factor beta 1 (TGF beta 1) in the
pathogenesis of oral submucous fibrosis (OSF), TGF beta 1 mRNAs in keratinocytes
of the paraffin embeded tissues of 25 OSF cases, 5 normals (NOR) and 10 oral
lichen planus (OLP) were determined by the in situ hybridization technique. The
result showed that there was an expression of TGF beta 1 mRNA in keratinocytes of
15 OSFs (60%). The positive expression of TGF beta 1 mRNA was mainly in
kerationcytes of early and middle stage OSF. There was no expression in that of 5
NORs and 10 OLPs. The study suggests that keratinocytes of OSF tissue may
synthesize and release TGF beta 1 which may play an important role in the
pathogenesis of OSF and participate as a mediator in the pathogenetic process of
OSF.
PMID- 10680516
TI - [A three-year clinical evaluation of five light-cured composite resins in
fillings of posterior teeth].
AB - In order to study the clinical performance and the evaluation method of light
cured composite resin in filling for posterior teeth, two evaluation methods were
used to evaluate 5 light-cured posterior composite resin fillings in 169 adult
posterior class I cavity. Results showed that each evaluation method has its own
advantages. The curative effect was declined with time in this study. Failures
and defects were mainly occurred after 3 years. Secondary caries, loss of
fillings and marginal stainings were the main reasons of failures. Compared with
the effect of 1 year, the success rate after 3 years declined significantly, and
further long-term clinical observation is needed.
PMID- 10680517
TI - [A study on the cytotoxicity of six filling materials in vitro].
AB - This paper deals with the cytotoxicologic analyses on 6 filling materials with
morphology of cells, ultraviolet light spectrophotometry and incorporation test
using mouse L-929 fibroblasts labelled 3H-TdR. The results showed that the
cytotoxicity of Silver amalgam and the Gallium-Silver alloys, which were produced
by mixing the conventional dental alloys powder or high copper alloys powder with
Gallium, was significantly stronger than that of light curing composites and the
Gallium-Silver alloys that were produced by the spherical amalgam alloys powder
and Gallium. It suggested that the level of mercury and copper in the alloys can
influence their cytotoxic properties.
PMID- 10680518
TI - [Perioral muscle forces and malocclusion].
PMID- 10680519
TI - [Power measurement of denervated muscle isografts with neurorrhaphy and nerve
implantation in rats].
AB - The hypothesis was tested in this experiment that after 7 months of
predencervation, the reinnervation of muscle grafts with neurorrhaphy results in
greater recovery of force and power than with nerve-implantation. In a highly
inbred strain of rats, soleus muscles were isografted. The donor muscles were
either immediately denervated at the time of isografting or denervated 2, 4, 7
months prior to isografting. Soleus muscles from each donor group were
transplanted into the right legs of hosts with either epineurial anastomosis (NR
group) or nerve implantation (NI group). The contralateral soleus muscles of
hosts served as controls. Sixty days after transfer, both right and left soleus
grafts/muscles were evaluated for force and power measured in situ. The absolute
force values were significant higher in NR group (61% of normal) than in NI group
(40% of normal) in 2-month group but the result invenrsted in 7-month group, less
than 20% and more than 20% of normal in NR and NI groups respectively. The
reduced ability of grafts to generate force and power resulted from the different
ways of reinnervation in denervated muscles and the period of predenervation.
Maybe the nerve-implantation is better than the neurorrhaphy for reinnervating a
long-term denervated muscle.
PMID- 10680520
TI - [Interleukin-8, a regulator of inflammation in gingival crevicular fluid].
AB - The role of interleuking-8 (IL-8), a neutrophil-attracting and-activating
cytokine, was investigated in gingival crevicular fluid (GCF). ELISA was used to
detect the levels of IL-8 in GCF collected from 54 adult periodontitis (AP)
patients (105 teeth) and 24 healthy subjects (54 teeth). The results showed that
1. The role of IL-8 was dependent upon the concentration of IL-8 in GCF. IL-8, in
the low concentration (< or = 30 micrograms/L), was positively correlated with
bleeding index (r = 0.36, P < 0.01). While in the high concentration (> 30
micrograms/L), was negatively correlated with bleeding index and probing depth (r
= -0.54 and r = -0.65 respectively, P < 0.01). In the majority of periodontitis
sites (91%), the concentration of IL-8 in GCF were lower than 30 microliters/L.
IL-8 most likely acted as pro-inflammatory factor in these teeth. 2. IL-8 was a
two-way regulator of inflammation, pro-inflammation and anti-inflammation. The
threshold of IL-8 between inducing and suppressing inflammation was approximately
30 micrograms/L. Within the confined range, IL-8 concentration greater than 30
micrograms/L could be inflammation suppressive, while a less-than-30 micrograms/L
concentration of IL-8 might become inflammation inducing.
PMID- 10680521
TI - [Evaluation of reproducibilty of the hinge-axis and it's positional relation to
condyles].
AB - The aim of this paper was to study the reproducibility of the positions of hinge
axis of mandibular retruded small open-closed movements, and the positional
relationship between the hinge-axis and condyles. Fourteen normal students were
tested by a six degrees of freedom mandibular movement recorder MT1602 (Germany).
The result showed that: the hinge-axis could not be exactly repeated and movable
instantaneous centers of rotation (ICR) were recorded. These rotation centers
distributed almost evenly around the condyles, the mean distance from these
rotation centers to condyle centers was about 8.83 +/- 5.65 mm.
PMID- 10680522
TI - [A comparative study of lanthanum, cerium and fluoride on the prevention of root
surface caries by various procedure].
AB - In order to evaluate the anticaries effects of several trace elements by combined
and respective treating procedure, studies on inhibiting demineralization and
improving remineralization were carried out with lanthanum, cerium and fluoride
in a pH-cycling condition. The analysis of polarized microscope and electron
microprobe demonstrated that the lanthanum and fluoride to an acetate buffer
solutions had less severe demineralization of root surface than individual
lanthanum or fluoride to the solution. The former, furthermore, precipitated a
compound membrane which may be F-La(Ce)-Ca containing crystal on the root
surface, and showed a better resistibility to acid. A further discussion was made
from the viewpoint of crystal physiochemistry.
PMID- 10680523
TI - [The healing process of the temporalis myofascial flap in oral reconstruction].
AB - From a prospective study of 36 patients having had temporalis myofascial flap
(mean follow-up 32 months), the clinical oral healing process and the
histological characteristics of the repaired mucosa were investigated. Among this
group, 24 patients were assessed of the clinical scarring over the reconstructed
area and 11 patients for histological evaluation of the repaired mucosa. Result
showed that the uncovered temporalis myofascial flap in the mouth underwent a
consistent healing commencing with an acute inflammatory phase, through chronic
inflammatory and proliferative phases to eventual epithelialization by oral
mucosa. No major complications affecting the healing flap were noted. The healed
mucosa exhibited scarring in 70% of cases and the repaired mucosa demonstrated
histological features distinct from the normal mucosa.
PMID- 10680524
TI - [Preliminary study of anatomic relation among nasopalatine duct, central incisor
root and floor of nasal cavity with X-ray measurement].
AB - The authors studied anatomic constructure of anaterior maxilla. They observed the
position relationships among nasopalatine duct, central incisor root and floor of
nasal cavity through X-ray measurement. The results showed: (1) Average distance
between the anterior wall of nasopalatine duct and cortical plate of anterior
maxilla was 7.80 +/- 1.43 mm. (2) Average distance between the anterior wall of
nasopalatine duct and central incisor root was 4.15 +/- 1.48 mm. (3) Average
distance between the tip of central incisor root and floor of nasal cavity was
12.62 +/- 2.47 mm. (4) Average length of the nasopalatine duct was 15.04 +/- 2.20
mm. The results are beneficial of dental implantation and orthognathic surgery.
PMID- 10680525
TI - [Observation of cervical vertebrae and estimation of their bone age].
AB - There are two objectives in this study: the first is to estimate skeletal age by
lateral cephalomatric roentgengram of cervical vertebrae instead of X-ray of
handwrist, the second is to study the rules of cervical vertebrae's growth and
development of children from Beijing. The Auto CAD 12.0 computer software was
used in measuring lateral cephalomatric roentgengrams of cervical vertebrae of
280 children from Beijing aged 9-15. The shape of cervical vertebrae of children
with that of adults on X-ray films was compared, and the growth and development
of cervical vertebrae of 9-15 years old children from Beijing was observed. We
found out that the rapid growth period of cervical vertebrae was 12-14 years old
for girls and 14-15 years old for boys. During puberty, the change of vertebrae's
shape has no difference between male and female. 42 female and 28 male teenagers
from the 280 aged 9-13 years old were taken X-ray films of left handwrist. The
comparison between the films and roentgengrams shows that the appearance of
sesamoid of hand and the concavity of the second vertebrae body is at the same
time, which means that the beginning of rapid growth period can be estimated by
the lateral cephalometric roentgengrams of cervical vertebrae.
PMID- 10680526
TI - [Preliminary research on radiographic manifestations of health odontal and
periodontal tissues in elderly people].
AB - Radiographs of mandibular first molars in 45 patients aged more than 60 year old
were measured on several parameters of pulpal chamber, root canal as well as
alveolar crest, and compared with those in 40 young people in order to study the
radiographic manifestations of the healthy odontal and periodontal tissues in
elderly people. Results shown that in aged people the average width and height of
the pulpal chamber and the diameter of root canal were narrower; the root canal
walls were thicker; the relation between the height of alveolar crest and the
root length reduced significantly; and the lamina dura on the alveolar crest
disappeared more common. Findings lay a preliminary foundation for investigation
on radiographic manifestations of involved teeth in gerontology.
PMID- 10680527
TI - [The immunogenicity of tooth allografts in mice].
AB - The mice used in this study were of the in-bred strains C57BL/6 and Balb/c which
differ at the major histocompatibility complex (MHC). The immunogenicity of tooth
allografts was studied in vitro by means of detecting the response of Antibody
Complement Mediated Cytotoxity (ACMC) and Cell Mediated Cytotoxity (CMC) of the
host. We found that there was significant difference for both ACMC and CMC
activity between the allogenic and isogenic tooth transplantation (P < 0.01). The
results indicate that tooth allografts are immunogens and do evoke the immune
response of recipients.
PMID- 10680528
TI - [A study on the changes of the estrogen level in the condylar cartilages in young
growing rats after functional mandibular protrusion].
AB - Fifty female SD rats of 4-week-old were selected, divided equally and randomly
into experimental and control groups. Simulated functional appliances were used
to guide the mandibles of the rats forwards. The animals were sacrificed after 3
days, 1 week, 2 weeks, 3 weeks and 4 weeks. The method of radioimmunoassay (RIA)
was performed to quantitively detect the level of estrogen in the condylar
cartilages. The results showed: 1. High levels of estrogen were detected in the
condylar cartilages during their actively proliferative period. When they
differentiated gradually, the levels of estrogen decreased. 2. The amount of
estrogen was increased significantly after functional mandibular protrusion,
especially during the period of the active proliferation of the condylar
cartilages. It is suggested that estrogen has a close relationship with the
hyperplasia and hypertrophy of the condylar chondrocytes and the increment of the
levels of estrogen in the condylar cartilages will further promote the
proliferation and functional adaptive remodelling of the condylar cartilages.
PMID- 10680529
TI - [The change of calcitonin gene-related peptide positive fibers in inflammatory
pulps].
AB - Deep cavities were prepared on rats' molars, and fresh carious dentin was
enclosed in to establish animal pulpitis model. Immunohistochemical method was
used to observe the distribution of calcitonin gene-related peptide (CGRP)
positive nerve fibers in rats' normal dental pulps and inflammatory pulps at 4d,
8d, 14d respectively. CGRP positive fibers were found throughout the normal
pulps, a large number of fibers penetrated into dentinal tubules. In 4d group,
CGRP positive fibers became denser and the number of fibers penetrating into
dentinal tubules also increased. In 8d group, a necrotic zone could be found in
the coronal pulps, lots of fibers accumulated around the necrotic zone. In the
radical pulps, CGRP positive fibers formed multiple arborizations. 14d
postinflammation, all the pulps were necrotic, and the periapexs were richly
innervated by CGRP positive fibers. The results suggesting that CGRP may play a
role in the inflammation and repair of dental pulp.
PMID- 10680530
TI - [Anatomy of the nasal cartilages of the unilateral lip and palate cleft nose].
AB - Noses of 6 stillborn infants with unilateral lip and complete palate cleft were
dissected and analysed. The surgical dissection revealed that the lower lateral
cartilages are asymmetrical on both sides, indicating displacement of the lower
lateral cartilages and the cartilageous septum which deviates to the normal side.
Paired T Test shown that there is no significant difference between two sides in
length and width. The conclusion is that the nasal deformities of the lip and
palate cleft are congenital and one of the major causal factors is the
displacement of lower lateral cartilages and cartilageous septum in the cleft
side.
PMID- 10680531
TI - [Ameloblastic carcinoma and malignant amelobastoma: histological
reunderstanding].
AB - Twenty-four cases of malignant ameloblastoma were reported, among them were
nineteen cases followed up for 5 to 30 years. Histologic characteristics include
predominated proliferation of the peripheral cells with papillary protruding to
stroma, replacement of the stellate reticular cells in the follicular center by
sarcomatous cells, as well as large and deep-stained or alveolar nuclei with
moderate atypia, and high mitosis of the tumor cells. Clinico-radiologically, the
tumor showed malignant features such as fast growing recently, pain, anesthesia,
cauliflower ulcer, limited mouth opening, and large multilocular radiolucent area
with ill-defined border. The biological behavior, nomenclature of the
ameloblastic carcinoma or malignant ameloblastoma, and differential diagnosis
from other tumors were also discussed.
PMID- 10680532
TI - [Clear cell odontogenic carcinoma].
AB - Histopathologic and immunohistochemical features of 3 cases of clear cell
odontogenic carcinoma were studied. The tumors were composed of sheets or islands
of clear cells separated by mature collageneous tissue. Basaloid cells were also
seen in the tumors. Tumor cells showed positive reactions for epithelial membrane
antigen and cytokeratin. More PCNA positive cells were seen in basaloid cells
than in clear cells. Metastasis to regional lymph nodes was found in all 3 cases.
PMID- 10680533
TI - [Immunobiological significance of S-100 protein positive dendritic cells (S
100+DC) in patients with oral squamous cell carcinoma].
AB - The purpose of this study is to investigate the role and clinical significance of
S-100+DC in oral squamous cell carcinoma. Distribution of S-100+DC in the tumor
tissues and regional lymph nodes (LN) of 60 patients with oral squamous cell
carcinoma was detected by immunohistochemistry (ABC). The results showed that the
S-100+DC density in tumor tissues was correlated with the tumor histologic grade
(P < 0.05). The density of S-100+DC was significantly higher in regional LN
without tumor than those with metastases (P < 0.05). However, there was no
difference of S-100+DC in tumor tissues between patients with and without
regional LN metastases. The distribution of S-100+DC in tumor tissues and
regional LN could be considered as a reference indicator of tumor histologic
grade and clinical prognosis of patients.
PMID- 10680534
TI - [The expression of proliferating cell nuclear antigen and p53 protein in salivary
gland tumours].
AB - The expressions and distributions of PCNA and p53 protein were studied with anti
PCNA and anti-p53 protein MoAbs, using immunohistochemical staining method in
salivary gland tumour. The relationship between PCNA and p53 protein was also
studied. Results indicated: Malignant mixed tumour (MmT) had a higher
proliferating index (PI) of PCNA. The PI could be used as one of adjuvant
diagnostic criteria; and as an important parameter for grading mucoepidermoid
carcinoma (MEC); The positive expression of p53 might be a good tumour marker for
MmT; Tumour tissues with positive expression of p53 had been shown higher PI of
PCNA, however there was no significance difference in our group; It remained to
be studied later.
PMID- 10680535
TI - [Oral Candida and its pathogenesis].
PMID- 10680536
TI - [Clinical significance of temporomandibular joint disk displacement].
PMID- 10680537
TI - [Trends of the development of modern ophthalmology and the knowledge composition
possessed by the ophthalmologists during the turn of centuries].
PMID- 10680538
TI - [The expression of EGF mRNA and EGF receptors in human trabecular meshwork cells
in vitro].
AB - OBJECTIVE: To demonstrate that cultured trabecular meshwork cells can secrete
epidermal growth factor (EGF) and there are EGF receptors (EGFRs) on the cells.
METHODS: Human trabecular meshwork cells were cultured in vitro and passaged 3-5
times. Immunohistochemical stain was used to detect EGFRs on the trabecular
meshwork cell membrane. EGF cDNA probe, alpha-32P isotope labeling and dot blot
hybridization autoradiographic method were used to detect EGF mRNA in the cells.
RESULTS: Cultured human trabecular meshwork cells were obtained. EGFR immunostain
was positive, and the reaction of brown color was at the surface of the cells.
Dot blot hybridization autoradiography showed that trabecular cells can express
EGF mRNA. CONCLUSIONS: Trabecular meshwork cells can secrete EGF. There are EGFRs
on the membrane of trabecular meshwork cells. It is suggested that probably up
regulating the receptors or promoting the cells to secrete growth factors have
potential significance in the regeneration of trabecular cells and recovery of
the cell functions in open angle glaucoma.
PMID- 10680539
TI - [The effects of pressure on cultured bovine trabecular meshwork cells].
AB - OBJECTIVE: To observe the effects of pressure on trabecular meshwork cells.
METHODS: Bovine trabecular meshwork cells were cultured and submitted to
different amounts of hydrostatic pressure. Cellular morphology and phagocytic
function were observed under inverted phase-contrast microscope, light microscope
and electron microscope. RESULTS: Compared with the control group, the cells
under 2.0 kPa or 2.67 kPa for 48 hours had no remarkable difference in criteria
observed. Those under 4.0 kPa for 24 hours showed slight changes in structure and
a mild decrease in phagocytic function. The damage appeared more severe if the
pressure was higher or lasted longer. CONCLUSION: Trabecular meshwork cells can
only bear pressure below a certain level. They may be destroyed structurally or
impaired functionally by pressure over this level.
PMID- 10680540
TI - [Application of proliferating cell nuclear antigen in the study of human
trabecular cell proliferation].
AB - OBJECTIVE: To evaluate the application of proliferating cell nuclear antigen
(PCNA) in the study of human trabecular cell proliferation. METHODS:
Immunohistochemical technique was used to observe the PCNA expressive level in
the fourth passage of human trabecular meshwork, the effects of different
concentrations of epinephrine, dexamethasone and epidermal growth factor on the
level were also investigated, the results were compared with that of the normal
cells cultured at the same time, and analyzed by a graphic device operation
system in a computer. RESULTS: A stable proliferating curve was obtained
according to the normal cell PCNA level, by which we could choose the best
opportunity of drug application. Epinephrine and dexamethasone were found to
significantly inhibit cell proliferation, while epidermal growth factor (EGF)
could promote the proliferation. CONCLUSION: PCNA is considered to be a useful
agent to observe the process of cell proliferation. The above mentioned methods
are beneficial to the investigations of biochemical characteristics of trabecular
meshwork cells and the pathogenic mechanisms of open-angle glaucoma.
PMID- 10680541
TI - [Ahmed valve implantation for refractory glaucoma].
AB - OBJECTIVE: To evaluate the short-term and long-term efficacy of Ahmed valve
implantation for refractory glaucoma and discuss its intraoperative and
postoperative complications and management. METHODS: 20 cases of refractory
glaucoma underwent Ahmed valve implantation, including 9 cases of neovascular
glaucoma, 7 cases of aphakic or pseudophakic glaucoma, 3 cases of congenital
glaucoma and one primary chronic angle-closure glaucoma. RESULTS: One month
postoperatively, the intraocular pressure (IOP) was less than or equal to 2.8 kPa
(1 kPa = 7.5 mmHg) in fifteen cases, with a total success rate of 75%. For cases
with neovascular glaucoma, the success rate was 55.6%, while for the others, the
rate was 90.9%. After six months of follow-up for 12 patients, the total success
rate was 58.3%, for neovascular glaucomas and other glaucomas, the rate was 40.0%
and 71.4%, respectively. The complications included transient hyphema, early
postoperative hypotony, obstruction of the tube tip, tube touch to lens or
cornea, tube exposure, exudative choroidal detachment and dropout of the plate.
CONCLUSION: Ahmed valve implantation is an effective method in the management of
refractory glaucoma in spite of its unnegligible complications.
PMID- 10680542
TI - [Ocular echographic evaluation of human aqueous drainage implant].
AB - OBJECTIVE: To determine after implantation of a glaucoma aqueous drainage device
whether fluid is present around the equatorial plate and to measure the bleb size
around the plate. METHODS: 41 plates in 41 patients (41 eyes) with refractory
glaucoma who had undergone human aqueous drainage (HAD) implantation underwent
standardized echography (both A- and B-scan examinations) after a mean
postoperative follow-up period, 5.2 months. According to the bleb height and the
fluid underlying and/or overlying the plate, the blebs were divided into five
grades and two types to evaluate their functions. RESULTS: Of the 41 cases
examined with echography, 35 (85%) were associated with posterior blebs, 2 (5%)
had no associated posterior blebs, and the posterior bleb in 4 (10%) cases was
not certain. The percentage of the presence of filtering bleb around the plate
was 15%, 12%, 29%, 37%, and 7% in Grade 0 to IV group, and 11% and 89% in type A
and B, respectively. There was no significant correlation between the bleb size
and the level of intraocular pressure control. CONCLUSION: Standardized ocular
echography is helpful in the postoperative management of failed cases who have
undergone HAD implantation because it can demonstrate the presence or absence of
blebs and characterize them.
PMID- 10680543
TI - [The relation of the changes of SOD and PGE2 in aqueous humor with the transient
rise of intraocular pressure after argon laser iridectomy].
AB - OBJECTIVE: To study the mechanism of transient rise of the intraocular pressure
(IOP) after argon laser iridectomy (ALI). METHODS: The rabbit changes of IOP, the
activity of superoxide dismutase (SOD) and the concentration of prostaglandin E2
(PGE2) in aqueous 15 min, 60 min, 6 hr, 24 hr, 48 hr after ALI, the relationships
of these changes with the transient rise of IOP, and the effects of using
indomethacin, cortisone, vitamin E and C before ALI on the transient rise of IOP
were observed. RESULTS: After ALI, the transient rise of IOP took place within
postoperative 6 hr. Following the postoperative transient rise of IOP, the
concentration of PGE2 in the aqueous was markedly increased, but the activity of
SOD in the aqueous markedly decreased. When indomethacin, cortisone, vitamin E
and C were used before ALI, the concentration of PGE2 was not markedly increased,
the activity of SOD was not markedly decreased and the postoperative transient
rise of IOP did not take place. CONCLUSIONS: The transient rise of IOP after ALI
is related to the increase of concentration of PGE2 and the decrease of activity
of SOD in the aqueous. Using indomethacin, cortisone, vitamin E and C before ALI
can effectively prevent the postoperative transient rise of IOP.
PMID- 10680544
TI - [Protective effects of exogenous superoxide dismutase on rabbit retinal injury by
acute intraocular hypertension].
AB - OBJECTIVE: To study active oxygen and free radical injury in rabbit retina during
elevated intraocular pressure and the protective effect of exogenous superoxide
dismutase (SOD) on the retinal damage by the hypertension. METHODS: Lipid
peroxidative product, malondialdehyde (MDA), activity of SOD and glutathione
peroxidase (GSH-Px), reduced GSH in the retinal tissue were measured during 24 h
after the release of an ocular hypertension, 6.67 kPa (1 kPa = 7.5 mmHg)
maintaining for 1.5 h, and the effects of retrobulbarly injected Cu-Zn-SOD on the
level of MDA and the activity of SOD in the retinal tissue after the release of
ocular hypertension for 12 h were observed. RESULTS: MDA increased gradually
during 0-12 h after the release of ocular hypertension and maintained at a
relatively high level in 12-24 h. The activity of SOD and GSH-Px was lower than
normal level immediately after the release, and then increased to a certain
different extent. But the activity of SOD began to decrease gradually 4 h after
the release. GSH had no significant changes during 24 h after the release.
Retrobulbar injection of Cu-Zn-SOD reduced the production of MDA in the retinal
tissue and enhanced SOD activity. CONCLUSIONS: Active oxygen and free radicals
participate the rabbit retinal injury by elevated intraocular pressure. A high
dose of Cu-Zn-SOD retrobulbar injection plays a beneficial role in enhancing the
antioxidative ability of the retina.
PMID- 10680545
TI - [Quantitative analysis of cAMP and cGMP in the plasma, iris and aqueous humor in
rabbits with high intraocular pressure].
AB - OBJECTIVE: To study the relationship between the levels of cyclic adenosine
monophosphate (cAMP), cyclic guanosine monophos-phate (cGMP) in the plasma, iris
and aqueous humor and high intraocular pressure in rabbits. METHODS: The
quantitative tests of cAMP and cGMP from rabbits were carried out by
radioimmunoassay technique. RESULTS: The results showed that there were 72.81 +/-
7.67, 141.08 +/- 16.70 and 28.40 +/- 0.49 of cAMP (nmol/L), and there were 10.37
+/- 6.15, 35.64 +/- 7.02 and 12.90 +/- 0.61 of cGMP (nmol/L) in the plasma, iris
and aqueous humor respectively. The levels of cAMP were higher than those in the
same samples from the animals as controls (P < 0.01), while the levels of cGMP
were less than controls (P < 0.01). CONCLUSION: High intraocular pressure may be
significantly associated with the levels of cAMP and cGMP.
PMID- 10680546
TI - [Changes of corneal topography and refraction after radial keratotomy and its
combination with transverse incision].
AB - OBJECTIVE: In order to understand the changes of morphology and refractive power
of cornea after radial keratotomy (RK) and its combination with transverse
incision (T-incision), and the wound healing of the T-incision. METHODS: Corneal
topography aided with a computer was used to analyze the changes of patients
having undergone RK and RK combined with T-incision. The wound healing was
analyzed, and the refractive powers of strong axis and weak axis of corneas were
measured. RESULTS: Corneal surface regularity index (SRI) and surface asymmetry
index (SAI) became greater and greater along with the increase of myopia
astigmatism. The refractive powers of corneal visual area 3, 5, 7 mm decreased
when getting closer to the center of the cornea. The refractive power of the
strong axis in cornea with RK combined with T-incision obviously decreased more
than that of RK. There was no such difference at weak axis between RK and RK
combined with T-incision. CONCLUSIONS: Corneal SAI and SRI will increase when
myopia-astigmatism increases. The morphologic changes are from positive non
spherical lens before surgery to negative non-spherical lens after surgery. The
increase of radius of curvature and the decrease of refractive power are due to
incisions. These phenomena become clearer when the incision getting closer to the
visual area or more incisions are performed. A T-incision less than 2 mm long
along the strong axis of astigmatism not only can lessen refractive power of
strong axis, but also can not affect RK results. This kind of T-incision does not
delay the wound healing either.
PMID- 10680547
TI - [A study of multi-channel visual evoked potentials in exotropic children without
amblyopia].
AB - OBJECTIVE: To investigate the clinical significance of multi-channel visual
evoked potentials (VEPs) in constant exotropic children without amblyopia and the
mechanism of exotropia. METHODS: With 14 active cup electrodes, and full and half
field stimulation, the checkerboard pattern was reversed and the VEPs were
recorded in control and experimental groups. RESULTS: With full field
stimulation, the latent period 1 (LP1) of binocular VEPs was not longer and the
amplitude N1-P1 (AN1P1) not higher respectively than those of monocular VEPs in
experimental group. These properties were different from those of control group.
The AN1P1 of non-dominant eye was decreased, and the LP1 of dominant and non
dominant eye was longer in experimental group than that of the control group.
There were no significant differences in comparing LP1 and AN1P1 between nasal
retina and temporal-retina of experimental group. CONCLUSIONS: VEPs can provide a
scientific basis for abnormal binocular vision in constant exotropia. Although
the visual acuity of constant exotropic children is normal, their VEPs are
abnormal. Therefore, there might be dysfunction in primary visual cortex. With
half field stimulation, there is no suppression of temporal-retina in monocular
VEPs of constant exotropic children.
PMID- 10680548
TI - [Clinical observation on pars plana lensectomy-vitrectomy preserving lens
anterior capsule].
AB - OBJECTIVE: To investigate the therapeutic effect of combined operation on
cataract complicated with vitreous pathology. METHOD: 19 patients (20 eyes) with
coexisting cataract and vitreous opacification or endophthalmitis or intraocular
foreign bodies were operated with pars plana lensectomy-vitrectomy preserving
lens anterior capsule. The ciliary sulcus intraocular lenses (IOLs) were
primarily implanted for sixteen eyes of 19 cases in the operation. RESULTS: All
cases were followed up for 12-36 months. Visual acuities of 18 cases were
improved, 7 eyes between 0.3-0.5, 11 eyes beyond 0.5, the best one at 1.2.
Anterior capsule opacification occurred merely in one eye, and in others the
capsule kept being transparent. CONCLUSION: Preserving anterior lens capsule in
the operation is beneficial to the insertion of IOL, and the anterior segment is
affected slightly, thus it is a promising method for treating cataract
complicated with vitreous opacification.
PMID- 10680549
TI - [Diagnosis and treatment of blowout fracture of the orbit].
AB - OBJECTIVE: To analyze the diagnosis and treatment of blowout fracture of the
orbit. METHODS: 78 cases with blowout fracture of the orbit seen in 20 years were
retrospectively analyzed. In different years, different methods of examinations
were used. There were 16 cases who had undertaken X-ray examinations, 31 cases,
ultrasonographic examinations and 72 cases, CT. RESULTS: The positive rate of the
CT examinations with blowout fracture of the orbit was 100%, CT having the
tendency to eventually replace the X-ray. Ultrasonography shows only changes of
intraorbital tissue, providing an auxiliary method for diagnosis. CONCLUSION:
With the progress of modern photographic methods, blowout fracture of the orbit
is known more deeply and the advance helps in the improvement of the treatment of
the disease.
PMID- 10680550
TI - [Cytological study of subretinal fluid].
AB - OBJECTIVES: To determine the cellular components of subretinal fluid and the
origin of cells participating in the proliferation in the membranous tissue of
proliferative vitreoretinopathy (PVR). METHODS: 35 subretinal fluid samples were
studied by cytology using autofluorescent and immunohistochemical assays.
RESULTS: There were a large quantity of retinal pigment epithelium (RPE) and
small quantity of pigment epithelial cells originated from epithelial cells of
ciliary body and iris, there were also various quantities of neuroretinal cells
and macrophages. Neither T-lymphocytes nor B-lymphocytes were found in this group
of samples. CONCLUSIONS: RPE, pigment epithelial cells, neuroretinal cells and
macrophages are in subretinal fluid and may participate in the formation and
development of PVR in various degrees.
PMID- 10680551
TI - [A preliminary study on the association between HLA-DPB1 gene and pathological
myopia].
AB - OBJECTIVE: To investigate the association between distribution of human leucocyte
antigen class II DPB1 alleles and pathological myopia (PM) among Chinese.
METHODS: The second exons of the HLA-DPB1 genes of 40 patients with PM were
amplified by polymerase chain reaction (PCR), individual PCR products were
digested by allele specific restriction enzymes: Bsp 1296 I, Fok I, Dde I, BsaJ
I, BssH II, Rsa I, Ava II and EcoN I. Genotype of each patient was determined by
restriction fragment length polymorphism (RFLP) pattern, then each DPB1 allele
frequency of PM was calculated and compared with healthy control. RESULTS: The
frequency of DPB1*0301 allele was significantly decreased in PM (Yates corrected
chi 2 = 4.33, Fisher exacted P = 0.032 < 0.05) and no statistically significant
difference was observed after P value was corrected by the number of compared
alleles. The rate of DPB1*0501/0501 homozygote has a significant difference
between PM and healthy controls (u = 2.27, P < 0.05). CONCLUSIONS: No genetic
susceptible or resistant allele exists in HLA-DPB1 gene of PM. The significant
increase of DPB1*0501/0501 homozygote in PM may be a linkage information.
PMID- 10680552
TI - [Research of daunomycin as an agent for preventing posterior capsule
opacification].
AB - OBJECTIVE: To investigate the inhibitory activity and the effective concentration
of daunomycin against the proliferation of lens epithelial cells in vitro, and
make progress in pharmacological prevention of posterior capsule opacification.
METHODS: Cultured bovine, rabbit and human lens epithelial cells were exposed to
0.5, 2.5, 5.0, 7.5 and 10.0 micrograms/ml daunomycin solution for ten minutes.
Growth of cells was observed, after 48 hours of exposure, absorbency of the cells
was tested by using Giemsa staining and colorimetry, and the median lethal dose
(LD50) was calculated respectively. RESULTS: Daunomycin significantly suppressed
the proliferation of bovine, rabbit and human lens epithelial cells in vitro,
showing dose-dependent manner. Daunomycin can effectively inhibit the
proliferation of human lens epithelial cells at the concentration of 0.5
microgram/ml, almost reaching the greatest effect at the concentration of 7.5
micrograms/ml. The calculated LD50 for bovine, rabbit and human lens epithelial
cells was 0.49, 4.30 and 4.06 micrograms/ml respectively. CONCLUSION: Short time
exposure of daunomycin at low concentration can effectively inhibit the
proliferation of lens epithelial cells in vitro, after further research in vivo,
daunomycin may possibly become a valuable agent for the prevention of posterior
capsule opacification.
PMID- 10680553
TI - Sex effects on rate of change of P300 latency with age.
AB - OBJECTIVE: Recent MRI evidence suggests that neuroanatomic structures may change
more rapidly with age in males compared with females. Sex differences for P300
latency were tested to determine whether similar results might appear for P300
latency, a neurophysiological measure sensitive to age and neurodegenerative
processes. METHODS: Auditory event related potentials (ERPs) were recorded using
an auditory 'oddball' to elicit the N200 and P300 components. Forty-two male and
42 female healthy normal subjects (age range 15-85 years) were entered in this
study. Both linear and curvilinear correlations of N200 and P300
latency/amplitude with age were tested. RESULTS: The slope of P300 latency on age
for males was steeper than for females at Pz in subjects who were 30 years of age
and older. N200 and P300 latencies were inversely correlated with age in young
adult males (<30 years old). CONCLUSIONS: Males may experience more rapid change
of P300 latency, but not amplitude, than females in middle to old age. Further
research is required to determine whether those change reflects neural
pathophysiology, or is mediated by such factors as neuroanatomic differences,
body temperature, or mild auditory deficits.
PMID- 10680554
TI - Event-related brain potentials in response to novel sounds in dementia.
AB - OBJECTIVE: Non-target, deviant stimuli generate an earlier latency, front-central
novelty P3, whereas correctly detected task-relevant stimuli generate a parietal
maximal target P3. We examined whether the P3 component to novel stimuli is
affected by dementing processes, and is therefore useful for distinguishing
Alzheimer's type dementia (AD) from vascular dementia (VD). METHODS: We recorded
ERPs to task-relevant stimuli (target P3) and novel task-irrelevant stimuli
(novelty P3) in an auditory oddball task in AD (n = 16), VD (n = 16), and age
matched controls (n = 18). The amplitude, latency, and scalp topography of target
and novelty P3 were compared among 3 groups using ANOVA. The relationship between
P3 measures and intelligence scores were evaluated by correlation analysis.
RESULTS: The amplitude, latency and scalp topography of the target P3 were
comparably affected by both AD and VD. However, the amplitude of the novelty P3
was markedly reduced in VD, but not in AD, and the scalp topographics were
different in the 3 groups. The amplitude was maximal at frontal sites in
controls, at central sites in AD, and at parietal sites in VD. The target P3
latency was prolonged in both AD and VD, whereas the novelty P3 latency was only
prolonged in VD. AD was discriminated satisfactorily from VD by using the novelty
amplitude at Cz and the ratio of the amplitudes at Fz and Pz as independent
variables. CONCLUSIONS: These results suggest that the response to novel stimuli
is differentially affected by dementia with degenerative and vascular etiology.
PMID- 10680555
TI - Sequential information processing during a mental arithmetic is reflected in the
time course of event-related brain potentials.
AB - OBJECTIVE: We hypothesized that mental arithmetic is a complex of sequential
information processing. In order to test the hypothesis, event-related potentials
(ERPs) were measured during 3 mental tasks. METHODS: Fifteen normal human
subjects performed the following tasks; (1) subjects added up every digit
delivered successively on a computer display, (2) subjects counted the number of
presented digits, or (3) subjects counted the number of meaningless patterns.
Spatiotemporal differences between ERP waveforms under the 3 tasks were studied
within the period of 1200 ms post-stimulus. RESULTS: During the adding task, N120
P180-N220 complex advanced in latency in the left frontal, central and parietal
regions. P300 increased in amplitude in the frontal and temporal regions during
adding and counting digits, which was specific to the digit presentation. A
positive slow potential depended on the adding task and showed two spatiotemporal
distributions; one was a widespread brain activity over the frontal, central,
temporal and parietal regions observed within 400-820 ms, and another was a brain
activity restricted to the frontal region lasting up to 1150 ms. CONCLUSIONS: The
results suggest that the early portion of ERPs reflects identification of
physical attributes of stimuli and numeric meaning of digits, and that the
positive slow potential reflects processes associated with calculation.
PMID- 10680556
TI - Identification of auditory evoked potentials of one's own voice.
AB - OBJECTIVE: We recorded vocalization related cortical potentials (VRCP) with
complete masking of one's own voice, and separated the feedback auditory
potentials following vocalization from the VRCP complex. METHODS: We used 9 right
handed healthy subjects. We recorded VRCP during simple vowel vocalizing under
two conditions, (1) without masking (control); (2) with masking.
Electroencephalography (EEG) was recorded from seven areas, Fz, Cz, Pz, C3, C4,
T3 and T4, of the International 10-20 system. The trigger point was the onset of
vocalized sound recorded through a microphone. RESULTS: In both control and
masking conditions, similar negative potentials prior to the vocalization were
observed. However, the amplitude just after the onset of vocalization was
significantly smaller in the masking than the control condition. The difference
waveform, obtained by subtracting the waveforms in the masking from those in the
control condition, showed a simple negative peak after the vocalization onset.
CONCLUSIONS: We considered that the difference waveform indicated the auditory
evoked potentials following own voice in the auditory feedback process. Since
there was no difference of the negative potentials before vocalization between
the two conditions, we speculated that the masking effect on auditory feedback
following vocalization was crucial, while its effect on the preparatory process
of simple vocalization might be minimal.
PMID- 10680557
TI - Maturation of human central auditory system activity: evidence from multi-channel
evoked potentials.
AB - OBJECTIVE: The purpose of this study was to evaluate central auditory system
maturation based on detailed data from multi-electrode recordings of long-latency
auditory evoked potentials (AEPs). METHODS: AEPs were measured at 30 scalp
electrode locations from 118 subjects between 5 and 20 years of age. Analyses
focused on age-related latency and amplitude changes in the P1, N1b, P2, and N2
peaks of the AEPs generated by a brief train of clicks presented to the left ear.
RESULTS: Substantial and unexpected changes that extend well into adolescence
were found for both the amplitude and latency of the AEP components. While the
maturational changes in latency followed a pattern of gradual change, amplitude
changes tended to be more abrupt and step-like. Age-related latency decreases
were largest for the P1 and N1b peaks. In contrast, P2 latency did not change
significantly and the N2 peak increased in latency as a function of age. Abrupt
changes in P1, P1-N1b, and N2 peak amplitude (also RMS amplitude) were observed
around age 10 at the lateral electrode locations C3 and C4, but not at the
midline electrodes Cz and Fz. These changes in amplitude coincided with a sharp
increase and plateau in AEP peak and RMS amplitude variability from 9 to 11 years
of age. CONCLUSIONS: These analyses demonstrated that the observed pattern of AEP
maturation depends on the scalp location at which the responses are recorded. The
distinct maturational time courses observed for individual AEP peaks support a
model of AEP generation in which activity originates from two or more at least
partly independent central nervous system pathways. A striking parallel was
observed between previously reported maturational changes in auditory cortex
synaptic density and, in particular, the age-related changes in P1 amplitude. The
results indicate that some areas of the brain activated by sound stimulation have
a maturational time course that extends into adolescence. Maturation of certain
auditory processing skills such as speech recognition in noise also has a
prolonged time course. This raises the possibility that the emergence of adult
like auditory processing skills may be governed by the same maturing neural
processes that affect AEP latency and amplitude.
PMID- 10680558
TI - The effect of interstimulus intervals and between-block rests on the auditory
evoked potential and magnetic field: is the auditory P50 in humans an overlapping
potential?
AB - OBJECTIVE: The human auditory P50 may consist of overlapping potentials. To test
this hypothesis, we manipulated interstimulus intervals (ISIs) and between-block
rests, and recorded the P50, P50m, N100 and the N100m simultaneously. METHODS:
Subjects were 12 right-handed healthy adults. Four conditions included: (1) 1.5
s/rest, (2) 1.5 s/successive, (3) 0.5 s/rest, and (4) 0.5 s/successive. Auditory
stimuli were presented a total of 880 times for each condition. Auditory evoked
potentials and magnetic fields were recorded. We examined the P50, N100, P50m,
N100m and dipoles of the P50m and the N100m. RESULTS: There was no significant
effect of the ISI on the P50 amplitudes, but the P50m amplitudes in the 0.5 s ISI
conditions were significantly smaller than those in the 1.5 s ISI conditions. The
N100 and the N100m amplitudes in the 0.5 s ISI conditions were significantly
smaller than those in the 1.5 s ISI conditions. The N100 and the N100m amplitudes
in the resting conditions were significantly larger than those in the successive
conditions. The P50m dipoles were slightly deeper and more anterior than those of
the N100m in primary auditory cortex. CONCLUSIONS: Central structures other than
supratemporal cortex contribute to the P50 and that the P50 in humans represents
overlapping potentials.
PMID- 10680559
TI - Steady-state visual evoked potentials and travelling waves.
AB - OBJECTIVE: The amplitude and phase of the steady-state visual evoked potential
(SSVEP) is sensitive to cognition and attention but the underlying mechanism is
not well understood. This study examines stimulus evoked changes in the SSVEP
phase topography and the putative role of travelling waves. METHODS: Eighteen
subjects viewed a central-field checkerboard and full-field flicker stimulus
temporally modulated at the peak alpha rhythm frequency. EEG was recorded from 10
midline scalp sites and the bipolar SSVEP obtained from differences between
adjacent electrodes. RESULTS: The SSVEP phase comprised either progressive
variations consistent with travelling waves or a phase reversal consistent with
standing waves. The checkerboard pattern elicited travelling wave patterns in 14
subjects with estimated phase velocities ranging from 7 to 11 m/s after
correcting for folded cortex. The flicker stimulus elicited phase reversals in 9
subjects, suggesting standing waves. Six subjects demonstrated a phase topography
specific to the stimulus with travelling wave patterns associated with the
checkerboard and standing wave patterns associated with the flicker. CONCLUSIONS:
These differences suggest the emergence of travelling and standing waves under
different spatial configurations of visual input to the cortex and that wave
phenomena contribute to the spatiotemporal dynamics of the SSVEP.
PMID- 10680560
TI - Functional properties of sub-bands of oscillatory brain waves to pattern visual
stimulation in man.
AB - The scalp recorded transient visual evoked potential (VEP) represents the massed
activity of a large number of neurons of the human visual cortex. Animal studies
show that intracerebrally-recorded high frequency electrical activity represents
binding between neurons participating in a cooperative response. We evaluated the
relationship between scalp recorded high frequency activity and transient VEPs
elicited by a repetitive (grating) pattern. Stimuli were 1 and 4 cycles/degree
sinusoidal gratings, presented in an on/off mode. Following conventional
averaging, the discrete wavelet transform (DWT) was applied. Multi-resolution
decomposition was used to divide the responses into 6 orthogonal frequency bands.
The results show that high frequency oscillatory activity in the beta and gamma
frequency range is closely related in time to the N70 peak of the simultaneous
VEP. Power in both bands is modulated by spatial frequency. Beta range response
to hemifield stimulation recorded over a chain of electrodes over the occipital
area lateralizes in the same manner as N70, while gamma range activity is
insensitive to lateralization and is more closely linked to foveal stimulation.
This dissociation between beta and gamma range activity suggests that different
bands of high frequency oscillatory activity in humans, linked to visual
stimulation, may represent different aspects of visual processing.
PMID- 10680561
TI - Dysfunction of small myelinated afferents in diabetic polyneuropathy, as assessed
by laser evoked potentials.
AB - OBJECTIVE: To verify whether laser evoked potentials are useful in assessing the
function of small afferent fibers and to compare dysfunction of large and small
afferent fibers in patients with diabetic polyneuropathy. METHODS: The brain
potentials evoked by CO2 laser stimulation of the hand and foot were studied in
diabetic patients (n = 45) with various degrees of peripheral nerve damage. Laser
evoked potentials (which assess the function of small myelinated afferents) were
also compared with ulnar and sural nerve sensory action potentials (which assess
the function of large myelinated afferents) by scoring the abnormalities of the
two neurophysiological tests with similar criteria. RESULTS: Laser evoked
potentials were often absent; the mean latency was normal and mean amplitude
decreased, as expected in axonopathies. Although clinical examination showed more
frequent impairment of vibratory than pinprick sensation, laser evoked potentials
and sensory action potentials yielded similar abnormality scores and showed a
strong intra-individual correlation. CONCLUSIONS: Laser evoked potentials,
possibly better than standard clinical examination for assessing the
abnormalities of small-diameter afferents, indicate that diabetic polyneuropathy
induces large- and small-afferent dysfunction in parallel.
PMID- 10680562
TI - Homeostatic sleep regulation in patients with idiopathic hypersomnia.
AB - OBJECTIVE: To determine whether the spectral activity during sleep of patients
with idiopathic hypersomnia (IH) differs from that of healthy subjects. METHODS:
Spectral analysis of the electroencephalogram (EEG) was performed in 10 patients
with IH and in 10 age-matched control subjects. We compared the time course of
absolute power for slow wave activity (SWA: 0.75-4.5 Hz), and for theta, alpha,
sigma and beta bands for the first 4 non-rapid-eye movement (NREM) episodes.
RESULTS: Compared to controls, IH patients had less SWA across the night although
the exponential decay was preserved. The fall in SWA was statistically
significant for the first two NREM episodes only. The lower power of SWA was
related to lower amounts of stages 3 and 4 of NREM sleep during the sleep
episodes. No correlation was found between SWA during the night and the mean
sleep latency on the multiple sleep latency test (MSLT). CONCLUSIONS: These
results showed that, in IH patients, the homeostatic sleep regulatory mechanisms
are preserved but the sleep pressure, indicated by SWA, is lower.
PMID- 10680563
TI - CAP components and EEG synchronization in the first 3 sleep cycles.
AB - OBJECTIVE: There is consolidated evidence that stage changes in sleep are closely
related to spontaneous EEG fluctuations centered on the 20-40 periodicity of the
cyclic alternating pattern (CAP). The present investigation aimed at assessing
the involvement of the different components of CAP in the process of build-up,
maintenance and demolition of deep non-REM (NREM) sleep. METHODS: CAP parameters
were quantified in the first 3 sleep cycles (SC1, SC2, SC3), selected from
polysomnographic recordings of 25 healthy sound sleepers belonging to an
extensive age range (10-49 years). Only ideal SCs were selected, i.e. the ones
uninterrupted by intervening wakefulness and in which all stages were represented
and linked in a regular succession of a descending branch, a trough and an
ascending branch. RESULTS: Among the first 3 SCs, a total amount of 45 (SC1, 16;
SC2, 13; SC3, 16) met the inclusion requirements. SCI contained the highest
amount of slow wave sleep (43.7 min) and the lowest values of CAP rate (31.6%).
The number of phase A1 subtypes remained unmodified across the 3 SCs (SC1, 48;
SC2, 48; SC3, 48), whereas both subtypes A2 (SC1, 9; SC2, 14; SC3, 14) and A3
(SC1, 2; SC2, 8; SC3, 10) increased significantly (P<0.028 and P<0.0001,
respectively). The A1 subtypes composed more than 90% of all the A phases
collected in the descending branches and in the troughs, while the A2 and A3
subtypes were the major representatives (64.3%) of the A phases occurring in the
ascending branches. CONCLUSIONS: Within the dynamic organization of sleep, the
non-random distribution of CAP sequences, with their succession of slow (subtypes
A1) and rapid (subtypes A2 and A3) EEG shifts, seem to be responsible for
sculpturing EEG synchrony under the driving and alternating forces of NREM and
REM sleep.
PMID- 10680564
TI - Measurement of lingual and palatine somatosensory evoked potentials.
AB - OBJECTIVE: A technique is presented for generating and recording lingual and
palatine nerve somatosensory evoked potentials (SEPs). METHODS: Pairs of thin,
stainless steel disk electrodes were mounted onto mandibular or maxillary acrylic
splints, similar to orthodontic retainers. Mandibular splint electrodes were
oriented to contact the under surface of the tongue along the course of the right
and left lingual nerves and maxillary splint electrodes were oriented to contact
the hard palate bilaterally along the course of the palatine nerves. SEP
recording electrodes were placed on the scalp 1 cm posterior to C5 and C6 (C5'
and C6', respectively) using the combinatorial nomenclature of the International
10-20 system. Two reference electrode locations, Fz and C5' or C6', over the
cortical hemisphere opposite that of the recording electrode, were used. RESULTS:
Right and left lingual and palatine nerve SEPs were recorded from five normal
adults. SEP latencies were similar to the N13 and P18 cortical peak latencies
recorded in previous studies of trigeminal nerve branches to the lips regardless
of reference electrode position. CONCLUSIONS: A more precise method of
stimulating the intraoral lingual and palatine nerves was accomplished using
dental splints. SEPs were easier to obtain using a contralateral cortex reference
electrode location.
PMID- 10680565
TI - Postanoxic alpha (theta) coma: a reappraisal of its prognostic significance.
AB - OBJECTIVES: To appraise the controversial prognostic significance of postanoxic
alpha or theta coma (ATC). METHODS: We prospectively assessed 14 comatose
patients with ATC after cardiac arrest by means of a protocol which included
repeated clinical examinations, EEG, and median somatosensory evoked potentials
(SEP). Good outcome was defined by the reappearance of cognition (Glasgow outcome
scale 3-5) at any time during the 1 year follow-up. RESULTS: Nine of 14 patients
had a monotonous, frontally accentuated and a reactive alpha (theta) EEG activity
(complete ATC). In these patients ATC was recorded a mean of 47 h after
resuscitation, the mean Glasgow coma scale (GCS) was 4 at 48 h, and early
cortical SEPs were altered or absent in 5 of 7 patients. All nine patients died.
In five of 14 patients the alpha (theta) EEG activity was either not monotonous,
partially reactive or posteriorly dominant (incomplete ATC). In these patients
ATC was recorded a mean of 43 h after resuscitation, the mean GCS was 8 at 48 h,
and early cortical SEP were normal in 4 of 5 patients. Three of 5 patients
regained cognition, two of them remained however dependent in activities of
everyday life. CONCLUSIONS: This study and a review 283 cases of postanoxic ATC
reported in the literature suggest the existence of incomplete and complete
variants of postanoxic ATC. Whereas complete ATC is invariably associated with a
poor outcome, full recovery is possible in patients with incomplete ATC. The
combination of EEG, clinical, and SEP findings improves the prognostic accuracy
of postanoxic ATC.
PMID- 10680566
TI - Differences in the dynamics of frontal sharp transients in normal and
hypoglycemic newborns.
AB - OBJECTIVE: This study focuses on the characteristics of frontal sharp transients
(FST), a normal variant of neonatal EEG, in newborns with hypoglycemia. METHODS:
The EEG from 20 newborns with symptomatic hypoglycemia were compared with a
control group of normal newborns matched by conceptional age. The dynamics of
these transients were evaluated concerning sleep stages. The density, type and
bilateral synchrony of FST were also calculated. The results were compared in the
two groups by Student's t test. RESULTS: When compared with controls,
hypoglycemic newborns have increased density of frontal sharp transients in all
sleep stages but less bilateral synchrony (P<0.05). FST density was even higher
in small for gestational age newborns. CONCLUSIONS: The data suggests that normal
patterns of neonatal EEG as FST can be influenced by systemic disturbances.
PMID- 10680567
TI - Gabapentin as add-on therapy in focal epilepsy: a computerized EEG study.
AB - OBJECTIVES: Gabapentin (GBP) possesses a well documented clinical efficacy in
those types of focal epilepsy otherwise resistant to conventional antiepileptic
drugs (AEDs); on the basis of this, it appears important to investigate the drug
effects on the EEG epileptiform and background activity. METHODS: Twenty-five
patients with cryptogenic or symptomatic partial epilepsy resistant to
conventional AED treatment were included in the study. All patients underwent
long-term video-EEG recordings before and after GBP addition (900-1200 mg/day).
RESULTS: Quantitative analysis of the interictal EEG paroxysms revealed that GBP
had no effect on the rate of occurrence of interictal and ictal EEG
abnormalities. GBP was active in delimiting the spatial extent of the interictal
spiking activity in those patients who displayed a significant reduction (> or
=50%) in seizure occurrence (32% of the patients). EEG background activity
recorded under rest condition from 18 out of 25 epileptic patients, before GBP
therapy, was characterised by a higher content of the slow spectral components
(delta and theta) with respect to control subjects. After GBP addition, the
increase of theta relative power was also evident during task performance.
CONCLUSIONS: These findings suggest that GBP does not interfere with the
generation of interictal EEG spiking while it appears to reduce the
susceptibility to seizures concomitantly with a limiting effect on the spiking
activity spatial extent. The utilization of GBP in controlling focal seizures is
reinforced by the absence of negative influence on cognitive functioning.
PMID- 10680568
TI - Patterns of motor control reorganization in a patient with mirror movements.
AB - OBJECTIVE: To explore motor control reorganization in a 40-year-old, left-handed
patient with perinatally acquired mirror movements. METHODS: We performed
simultaneous bilateral recordings of motor evoked potentials (MEPs) following
focal transcranial magnetic stimulation (fTMS) and of central silent period (cSP)
during unilateral voluntary contraction in abductor pollicis brevis (APB) and
abductor digiti minimi (ADM) muscles. RESULTS: For both muscles the MEP study
showed bilateral fast-conducting corticospinal projections from the right
undamaged hemisphere, and residual contralateral projections from the left
hemisphere. The cSP findings differed in the two muscles: the mirror phenomenon
was bilateral in the ADM, but present only on the right side in the APB muscles;
the mirror activity of right ADM and APB muscles was inhibited only by fTMS of
the ipsilateral right motor cortex; the mirror phenomenon in the left ADM muscle
was inhibited only by fTMS of the contralateral right motor cortex. CONCLUSIONS:
Mirror movements of right APB and ADM muscles were sustained by the ipsilateral
connections from the undamaged motor cortex, while the mirror phenomenon in the
left ADM muscle could be explained by hypothesizing a bilateral activation of
motor cortices. This previously unreported electrophysiological picture
demonstrates that different patterns of motor control may realize after perinatal
cerebral lesions, even in different distal muscles of the same patient.
PMID- 10680569
TI - Electroencephalographic measurement of motor cortex control of muscle activity in
humans.
AB - OBJECTIVE: To detect and measure correlation between cortical and muscle
activities, coherence analysis was used. METHODS: The electroencephalogram (EEG)
and electromyogram (EMG) were recorded in 9 normal volunteers during tonic
contraction of upper and lower limb muscles on the right side. Coherence between
EEG and EMG was computed to analyze their linear association. RESULTS: EEG over
the contralateral sensorimotor area was coherent with EMG, with peak coherence at
11-36 Hz (mean, 22 Hz). For the abductor pollicis brevis (APB) muscle, peak
coherence, as determined by functional brain mapping with focal transcranial
magnetic stimulation (TMS), was over or slightly posterior to the hand area on
the primary motor cortex determined by focal transcranial magnetic stimulation
(TMS). Peak coherence over the scalp was somatotopically organized. The temporal
relation between EEG and EMG was analyzed with a new model for interpreting the
phase shift ('constant phase shift plus constant time lag' model). For the APB
muscle, the phase relation between cortical and muscular oscillations differed in
the frequency ranges of 3-13 Hz and 14-50 Hz, respectively, suggesting that
different coupling mechanisms operate in different bands. Only the phase shift
between cortical and motoneuronal firing at 14-50 Hz was reliably estimated by a
linear model. At 14-50 Hz, motoneuronal firing was led by surface-negative
cortical activity with a constant time lag that depended on the cortical-muscular
distance. For the APB muscle, the time lag was slightly shorter than the cortical
muscular conduction time determined by TMS. Vibratory stimulation (100 Hz) of a
muscle tendon during tonic contraction had no significant effect on cortical
muscular coherence, indicating that cortical oscillation reflected motor rather
than sensory activity. CONCLUSIONS: The present findings suggest temporal coding
of the oscillatory motor control system (3-13 Hz vs. 14-50 Hz), and confirm the
functional importance of cortical beta and gamma rhythms in the motor efferent
command. Cortical-muscular synchronization is most likely mediated by the direct
corticospinal pathway within the frequency range of 14-50 Hz.
PMID- 10680570
TI - A novel quantitative method for 3D measurement of Parkinsonian tremor.
AB - OBJECTIVE: To demonstrate the usefulness of a three dimensional (3D) motion
analysis system for the quantitative measurement of tremor in patients with
Parkinson's disease (PD). METHODS: Six PD patients with hand tremors were studied
using a system that employed 3D electromagnetic position sensors to measure the
actual, cumulative displacement of the tremoring finger. Patients were studied in
different hand positions and activating conditions before and 30, 60, 90 and 120
min after intake of Pramipexole, a dopamine agonist known to reduce tremor.
Tremor amplitude and frequency, before and after drug intake, were compared using
Mann-Whitney U test and Wilcoxon rank test, respectively. RESULTS: The motion
analysis system allowed discrimination of tremor related events from movement
artifact and allowed the calculation of real world movement of the finger tremor
despite altered hand positions and orientation. Average 3D tremor frequency
ranged from 3.71 to 4.34 Hz. Median tremor amplitude (total distance traveled per
5 s interval) decreased with drug from 4.9 to 1.6 cm for resting tremor, 4.5 to
3.7 cm for postural tremor, 3.4 to 3.3 cm for precision tremor, 10.2 to 3.3 cm
for tapping activation and 108.6 to 5.7 cm for counting activation. CONCLUSIONS:
Our method of 3D analysis provides a robust, single quantitative measure of
tremor amplitude that is intuitive and likely to reflect the functional impact of
tremor. This methodology should be useful in comparing tremor across patients and
in measuring the efficacy of therapeutic interventions.
PMID- 10680571
TI - Changes in motor cortex excitability during ipsilateral hand muscle activation in
humans.
AB - OBJECTIVES: To test whether unilateral hand muscle activation involves changes in
ipsilateral primary motor cortex (M1) excitability. METHODS: Single- and paired
pulse transcranial magnetic stimulation (TMS) of the right hemisphere was used to
evoke motor evoked potentials (MEPs) from the resting left abductor pollicis
brevis (APB) in 9 normal volunteers. We monitored changes in motor threshold
(MT), MEP recruitment, intracortical inhibition (ICI) and intracortical
facilitation (ICF) while the ipsilateral right APB was either at rest or
voluntarily activated. Spinal motoneuron excitability was assessed using F-wave
recording procedures. RESULTS: Voluntary muscle activation of the ipsilateral APB
significantly facilitated the MEPs and F-waves recorded from the contralateral
APB. Facilitation was observed with muscle activation >50% of the maximum
voluntary force and with stimulus intensities >20% above the individual resting
motor threshold. Intracortical inhibition significantly decreased in the
ipsilateral M , while there was no significant change in intracortical
facilitation during this maneuver. CONCLUSIONS: Unilateral hand muscle activation
changes the excitability of homotopic hand muscle representations in both the
ipsilateral M1 and the contralateral spinal cord. While the large proportion of
MEP facilitation most likely occurred at a spinal level, involvement of the
ipsilateral hemisphere may have contributed to the enlargement of magnetic
responses.
PMID- 10680572
TI - Movement-related potentials in the human spinal cord preceding toe movement.
AB - OBJECTIVES: A method by which potentials related to voluntary movement can be
recorded noninvasively from the human spinal cord is presented. METHODS: A novel
signal processing technique performed on signals recorded by surface electrodes
placed over the spinal column was used to filter time-locked back muscle noise,
so that the only remaining signals were the spinal movement-related potentials
from the brain to the limbs and vice versa. RESULTS: The signals obtained from 7
subjects using this technique are shown and temporally compared with movement
related cortical potentials (MRCP) and muscle electromyogram. It is demonstrated
that the spinal signal starts approximately 600 ms before the actual movement,
and that some features of this signal correspond to changes in cortical
potentials. CONCLUSIONS: These findings imply that the spinal cord is not a
simple command-carrying medium from the brain to the limbs, and implies that some
computational activities take place at the spinal cord level.
PMID- 10680573
TI - The short exercise test is normal in proximal myotonic myopathy.
AB - OBJECTIVES: Proximal myotonic myopathy (PROMM) is a multisystem disorder that may
mimic myotonic dystrophy (MD). Previously we demonstrated that the 60 s exercise
test was normal in two siblings with PROMM. The test enabled distinction of PROMM
from MD, as there is a well documented immediate post-exercise compound muscle
action potential (CMAP) amplitude decline in MD. METHODS: We now performed
exercise testing using several exercise durations in 8 PROMM patients from 6
kinships, and one MD patient, extending our previous observations. Repetitive
stimulation and needle electromyography findings were also recorded. RESULTS: The
10 (n = 8), 30 (n = 5), and 60 (n = 5) s, and the 5 min (n = 1) exercise tests
were normal in all PROMM patients. Specifically, the maximum post-exercise CMAP
amplitude decline was 8%. In contrast, the MD patient had CMAP amplitude declines
of 48% (10 s exercise test) and 26% (30 s exercise test). The distribution of
repetitive stimulation and motor unit duration abnormalities were variable and
less diagnostically useful. CONCLUSIONS: The 10, 30, and 60 s exercise tests help
distinguish PROMM from MD. As the 10 s exercise test is rapid and easily
tolerated, we recommend this test for clinical testing.
PMID- 10680574
TI - Asynchronous burst suppression.
PMID- 10680575
TI - Biological effects of resveratrol.
AB - Resveratrol (3, 4', 5 trihydroxystilbene) is a naturally occuring phytoalexin
produced by some spermatophytes, such as grapevines, in response to injury. Given
that it is present in grape berry skins but not in flesh, white wine contains
very small amounts of resveratrol, compared to red wine. The concentrations in
the form of trans- and cis- isomers of aglycone and glucosides are subjected to
numerous variables. In red wine, the concentrations of the trans-isomer, which is
the major form, generally ranges between 0.1 and 15 mg/L. As phenolic compound,
resveratrol contributes to the antioxidant potential of red wine and thereby may
play a role in the prevention of human cardiovascular diseases. Resveratrol has
been shown to modulate the metabolism of lipids, and to inhibit the oxidation of
low-density lipoproteins and the aggregation of platelets. Moreover, as
phytoestrogen, resveratrol may provide cardiovascular protection. This compound
also possesses anti-inflammatory and anticancer properties. However, the
bioavailability and metabolic pathways must be known before drawing any
conclusions on the benefits of dietary resveratrol to health.
PMID- 10680576
TI - Melatonin synthesis in the greenfrog retina in culture: I. Modulation by the
light/dark cycle, forskolin and inhibitors of protein synthesis.
AB - Melatonin is synthesized in the pineal gland and the retina of vertebrates.
Retinal serotonin N-acetyltransferase (NAT) activity and melatonin show a daily
rhythm with high levels during the dark phase of the photocycle. In some
vertebrates, these retinal NAT and melatonin rhythms are maintained in vitro. The
aim of present work is to develop an eyecup culture system for the greenfrog
(Rana perezi), suitable to analyze the mechanisms of regulation of melatonin
synthesis by simultaneous determination of NAT activity and melatonin release.
The R. perezi eyecups released melatonin to the culture medium in a rhythmic
manner at least over a 27-h period under photocycle conditions. NAT activity and
melatonin rhythms were similar to that observed in vivo under natural
environmental conditions. Rana perezi retina exhibits a pronounced
photosensitivity in vitro. Forskolin increased up to 2-fold the NAT activity and
4-fold the melatonin production at any lighting conditions. The addition of the
translation inhibitor, cycloheximide, to the medium reduced significantly both
nocturnal NAT activity and melatonin release, suggesting that de novo protein
synthesis is produced daily during darkness. Actinomycin D, a transcription
inhibitor, needs a longer time of action, because pre-existing mRNA must be
depleted before the inhibition of melatonin release can be observed. The eyecup
culture system is highly sensitive to light and chemical factors, which makes it
particularly suitable as a model for the neurochemical analysis of melatonin
biosynthesis in the retina of Rana perezi.
PMID- 10680577
TI - Melatonin synthesis in the greenfrog retina in culture: II. Dopaminergic and
adrenergic control.
AB - Serotonin N-acetyltransferase (NAT) activity and melatonin show a daily rhythm
with high levels at night. Although the rhythmic properties of NAT and melatonin
are similar in pineal gland and retina, great differences in the light perception
and transmission mechanisms exist. We have analyzed the effects of adrenergic and
dopaminergic agents on greenfrog (Rana perezi) eyecup culture, in order to
identify the receptors involved in the regulation of retinal melatonin synthesis.
A D2-like receptor is directly involved in the regulation of NAT activity and
melatonin release in R. perezi retina. Quinpirole mimics the effect of light,
reducing the darkness-stimulated NAT activity and melatonin release, while
sulpiride antagonized these actions. Neither D1-agonist (SKF 38393) nor D1
antagonist (SCH 23390) had effect on NAT activity. However, a significant
inhibition of darkness-evoked melatonin release was produced by SKF 38393 after 6
hours of culture. The beta- and antagonist1-agonists showed a clear inhibition.
However, a direct effect of beta, alpha1 and D1-agonists on photoreceptors is
unproven, being more probable that the adrenergic actions imply a non
photoreceptor retinal cell. In conclusion, eyecup culture of Rana perezi revealed
a dopaminergic control of melatonin synthesis and a possible modulation of
dopaminergic tone by adrenergic receptors. Melatonin release is a more sensitive
parameter than NAT activity to the action of neuroactive agents, suggesting that
melatonin synthesis can be regulated by more than one enzymatic step in Rana
perezi.
PMID- 10680578
TI - Effect of vitamin E on the response to ischemia-reperfusion of Langendorff heart
preparations from hyperthyroid rats.
AB - Hyperthyroidism has been reported to decrease heart antioxidant capacity and
increase its susceptibility to in vitro oxidative stress. This may affect the
heart response to ischemia-reperfusion, a condition that increases free radical
production. We compared the functional recovery from in vitro ischemia
reperfusion (Langendorff) of hearts from euthyroid (E), hyperthyroid (H, ten
daily intraperitoneal injections of T3, 10 microg/100g body weight), vitamin E
treated (VE, ten daily intramuscular injections, 20 mg/100g body weight) and
hyperthyroid vitamin E-treated (HVE) rats. We also determined lipid peroxidation,
tissue antioxidant capacity and the tissue capability to face an oxidative stress
in vitro. A significant tachycardia was displayed during reperfusion following 20
min ischemia by the hyperthyroid hearts, together with a low recovery of left
ventricular developed pressure (LVDP) and left ventricular dP/dt(max). When H
hearts were paced at 300 beats/min, the functional recovery (LVDP and dP/dt(max))
was close to 100% and significantly higher than in E paced hearts. At the end of
the ischemia-reperfusion protocol, myocardium antioxidant capacity was
significantly lower, whereas lipid peroxidation and the susceptibility to in
vitro oxidative stress were higher in the T3 treated (H) than in euthyroid rats.
The in vitro tachycardic response, the reduction in the antioxidant capacity and
the increase in lipid peroxidation were prevented by treatment of hyperthyroid
rats with vitamin E (HVE). These results suggest that the tachycardic response to
reperfusion following chronic T3 pretreatment was associated with the reduced
capability of the heart to face oxidative stresses in hyperthyroidism.
PMID- 10680579
TI - Antioxidative activity of natural products from plants.
AB - A variety of flavonoids, lignans, an alkaloid, a bisbenzyl, coumarins and
terpenes isolated from Chinese herbs was tested for antioxidant activity as
reflected in the ability to inhibit lipid peroxidation in rat brain and kidney
homogenates and rat erythrocyte hemolysis. The pro-oxidant activities of the
aforementioned compounds were assessed by their effects on bleomycin-induced DNA
damage. The flavonoids baicalin and luteolin-7-glucuronide-6'-methyl ester, the
lignan 4'-demethyldeoxypodophyllotoxin, the alkaloid tetrahydropalmatine, the
bisbenzyl erianin and the coumarin xanthotoxol exhibited potent antioxidative
activity in both lipid peroxidation and hemolysis assays. The flavonoid rutin and
the terpene tanshinone I manifested potent antioxidative activity in the lipid
peroxidation assay but no inhibitory activity in the hemolysis assay. The lignan
deoxypodophyllotoxin, the flavonoid naringin and the coumarins columbianetin,
bergapten and angelicin slightly inhibited lipid peroxidation in brain and kidney
homogenates. It is worth stressing that the compounds with antioxidant effects in
this assay, with the exception of tetrahydropalmatin and tanshinone I, have at
least one free aromatic hydroxyl group in structure. Obviously, the aromatic
hydroxyl group is very important for antioxidative effects of the compounds. None
of the compounds tested exerted an obvious pro-oxidant effect.
PMID- 10680580
TI - Antioxidative and free radical scavenging activities of selected medicinal herbs.
AB - The antioxidative and superoxide- and hydroxyl radical-scavenging activities and
pro-oxidant effect of twelve selected medicinal herbs were studied. The aqueous
extracts of Coptis chinensis, Paeonia suffruticosa, Prunella vulgaris and Senecio
scandens exhibited the highest potency in inhibiting rat erythrocyte hemolysis
and lipid peroxidation in rat kidney and brain homogenates. The aforementioned
four herbs also demonstrated strong superoxide- and hydroxyl radical-scavenging
activity, but exerted only a slight pro-oxidant effect.
PMID- 10680581
TI - Lack of effects of glycineB receptor ligands on the psychostimulant-induced
discriminative stimuli in rats.
AB - To examine the role of glycineB receptors in the stimulus effects induced by
psychostimulants, separate groups of rats were trained to discriminate
amphetamine (AMPH; 1 mg/kg) from saline (SAL), or cocaine (COC; 10 mg/kg) from
SAL, using a two-lever operant procedure. Substitution studies showed that
neither 1-aminocyclopropanecarboxylic acid (ACPC; 200 mg/kg) nor 7-chloro-4
hydroxy-3-(3-phenoxy)phenyl-(H)quinolone (L-701,324; 3 mg/kg), being a partial
agonist or an antagonist at glycineB receptors, respectively, generalized for the
training drugs. Combination tests of glycineB ligands demonstrated that injection
of a fixed dose of ACPC (200 mg/kg) or L-701,324 (3 mg/kg) together with
different doses of AMPH or COC practically did not modify dose-response curves of
the psychostimulants, nor did it affect their ED50 values. Our results indicate
that glycineB receptors do not play a role in the discriminative effects of AMPH
and COC.
PMID- 10680582
TI - Treatment and survival study in the C57BL/6J-APC(Min)/+(Min) mouse with R
flurbiprofen.
AB - Our previous studies with the mouse model of familial adenomatous polyposis
(FAP), C57BL/6J-APC(Min)/+ or Min mouse, demonstrated the optimal dose for
adenoma reduction with R-flurbiprofen was 10 mg/kg/day as an undivided dose.
Divided doses exhibited no increased efficaciousness. This study examines 10
mg/kg R-flurbiprofen daily (qd) on survival as well as a second daily (q.o.d.)
schedule and compares it with sulindac sulfone. The q.o.d. schedule at 10 mg/kg
was equally efficacious as qd treatment at the same dose. For the q.o.d. group,
tumor number decreased similarly (p<0.01); while body weight gain (p<0.01),
hematocrit and average tumor area (both, p<0.05) were improved compared with qd
treatment. Treatment with R-flurbiprofen (10 mg/kg/day) increased survival
significantly (p=0.0004, log-rank) compared to vehicle treated animals. Major
biological endpoints (hematocrit, weight gain, tumor number, average and total
area [99% reduction]) were significantly improved in treated animals (p<0.01).
Sulindac sulfone treatment (50 mg/kg/day) of the Min mouse produced no
significant biological benefit. The dose schedule study suggests that for tumor
reduction it is necessary to attain a threshold drug-level but not necessarily
sustain it over 24 hrs (pharmacodynamic t1/2 >> pharmacokinetic t1/2). During the
period of administration R-flurbiprofen dramatically prolongs survival for the
mouse model of the human disease, FAP.
PMID- 10680583
TI - The mechanism underlying the hypocholesterolaemic activity of aqueous celery
extract, its butanol and aqueous fractions in genetically hypercholesterolaemic
RICO rats.
AB - Drinking aqueous celery extract for 8 weeks caused a significant reduction in
serum total cholesterol (TC) level in growing genetically hypercholesterolaemic
(RICO) rats. In addition, administration of butanol fraction (Fbu) and aqueous
fraction (Faq) of celery extract for 7 days by intraperitoneal (i.p.) infusion
effectively decreased the serum TC and high-density lipoprotein cholesterol (HDL
C) levels of adult RICO rats. The 8-week study showed that oral intake of celery
extract could enhance the 14C-cholesterol/metabolites excretion. The liver and
small intestinal sterol synthesis were not affected. Also, long term drinking of
aqueous celery extract did not lead to any undesirable side effects on liver
functions. The Fbu and Faq lowered serum TC level mainly through increased bile
acid excretion but not by modulating the activity of the rate-limiting enzyme for
cholesterol biosynthesis, HMG-CoA reductase. Hence, the mechanism elucidated
supports that suggested by the 8-week study. A preliminary chemical
characterisation of Fbu and Faq fractions by thin layer chromatography (TLC)
showed the presence of sugars and amino acids. There is a possibility that polar
compounds with sugar or amino acid side chains(s) could contribute to the
hypocholesterolaemic action of celery extract.
PMID- 10680584
TI - Genetic evidence that cocaine and caffeine stimulate locomotion in mice via
different mechanisms.
AB - The effects of cocaine and caffeine on motor activity in two mouse strains
129/OlaHsd (129) and C57BL/6J (C57) were compared. The former mice exhibited
lower basal motor activity than the latter. Cocaine (3, 10, 30 mg/kg) injected
i.p. in habituated C57 mice produced a dose-dependent increase in rearing,
motility and locomotion. In 129 mice, little or no stimulation was seen and only
with the highest dose of cocaine. In both strains caffeine (3, 15, 30 mg/kg)
produced a dose-dependent increase in rearing, motility and locomotion. The
effect of caffeine on rearing was greater in C57 than in 129 mice, but motility
and locomotion were stimulated approximately to the same degree in both strains.
Thus, differences in the sensitivity to caffeine and cocaine between mouse
strains provide genetic evidence that these two stimulants probably produce
locomotor stimulation via somewhat different mechanisms.
PMID- 10680585
TI - Orphanin FQ/nociceptin inhibits morphine withdrawal.
AB - The influence of orphanin FQ/nociceptin (OFQ/N) on the morphine-withdrawal
symptom was investigated. Withdrawal syndrome was induced in the morphine
dependent rats by an intraperitoneal (i.p.) injection of 2 mg/kg naloxone
hydrochloride--an opioid receptors antagonist. Wet-dog shakes were used as a
measure of the abstinence syndrome. Intraventricular injections of OFQ/N (5-20
microg/animal) caused significant inhibition of the withdrawal signs at doses
between 15-20 microg, in the morphine-dependent rats. OFQ/N alone did not change
behavior of the morphine-dependent animals. The obtained results indicate that
OFQ/N can inhibit the morphine withdrawal symptoms induced by naloxone.
PMID- 10680586
TI - Evaluation of carcinogenic and co-carcinogenic potential Quinalphos in mouse
skin.
AB - Quinalphos [O,O-diethyl-O-quinoxalinyl-phosphorothidate] is an organophosphorus
pesticide with tremendous utility in mixed pest control due to its insecticidal
and acaricidal properties. Apart from its pesticidal property, Quinalphos is
known to induce various toxic effects in nontarget species and experimental
animals. No studies have been conducted to evaluate the carcinogenic/co
carcinogenic hazards associated with Quinalphos exposure. In the present set of
investigations, the tumorigenic potential of Quinalphos has been evaluated
following topical exposure in Swiss albino mice. Long-term animal bioassays
conducted for the evaluation of complete carcinogenic, tumour-initiating and
tumour-promoting potential of Quinalphos revealed that it has only tumour
initiating potential at a dose of 10 mg/kg body weight (b.wt.), in the two-stage
mouse skin model of carcinogenesis. Quinalphos exposure failed to produce
neoplasia when tested for complete carcinogenic activity at all three tested dose
levels or tumour promoting activity.
PMID- 10680587
TI - Effect of Withania somnifera on cyclophosphamide-induced urotoxicity.
AB - Administration of an extract from the plant Withania somnifera (Family:
Solanaceae) (20 mg/dose/animal; i.p.) for five days along with cyclophosphamide
(CTX) (1.5 mmol/kg body wt. i.p.) reduced the CTX induced urotoxicity.
Morphological analysis of the bladders of the CTX-treated group showed severe
inflammation and dark coloration whereas CTX along with the Withania-treated
group showed normal bladder morphology. The extract was found to reduce the
protein level in the serum (7.92 g/l) after 4 h of CTX treatment, which was
higher in the CTX alone-administered group (11.44 g/l). Blood urea N2 level which
was drastically enhanced (136.78 mg/100 ml) 2 after the CTX treatment was
significantly reduced (52.08 mg/100 ml) when the animals were treated with
Withania extract. Similarly the glutathione (GSH) content in both bladder (1.55
micromol/mg protein) and liver (3.76 micromol/mg protein) was enhanced
significantly (P<0.001) in the Withania-treated group compared with the CTX alone
treated animals (bladder 0.5 micromol/mg protein; liver 1.2 micromol/mg protein)
Histopathological analysis of the bladder of CTX alone-treated group showed
severe necrotic damage where as the Withania somnifera-treated group showed
normal bladder architecture.
PMID- 10680588
TI - Inhibitory effect of Coptidis Rhizoma and berberine on the proliferation of human
esophageal cancer cell lines.
AB - Our previous study demonstrated that the herbal medicine, Oren-to, had antitumor
effects on esophageal cancer cells (ECCs) in vitro. The purpose of this study was
to examine which of the seven constituents of Oren-to had antitumor effects on
esophageal cancer cells. MTT assay showed that, of the seven constituents, only
the aqueous extract of Coptidis Rhizoma had potent inhibitory effect on the
proliferation of two types of ECC lines, YES-3 and YES-4. In addition, the
proliferation of all six types of ECC lines (YES-1 to YES-6) was inhibited in a
dose-dependent manner (P<0.001 for all), when co-cultured at each concentration
of Coptidis Rhizoma for 72 h. The ID50 of Coptidis Rhizoma for YES-1 to YES-6 was
2.2 microg/ml, 3.0 microg/ml, 0.25 microg/ml, 2.8 microg/ml, 2.5 microg/ml, and
0.5 microg/ml, respectively, berberine, one of protoberberine components of
Coptidis Rhizoma, showed potent antitumor effects on all six types of ECC lines
as well as Coptidis Rhizoma. In addition, the ID50 of berberine showed a positive
correlation with that of Coptidis Rhizoma in six types of ECC lines examined (r2
= 0.763, P = 0.023). Cell cycle analysis of Coptidis Rhizoma-treated cancer cells
showed the accumulation of cells in the G0/G1 phase and relative decrease of the
S phase. These results support the possibility that the use of Coptidis Rhizoma
containing abundant berberine may be useful as one of alternative therapies for
esophageal cancers.
PMID- 10680589
TI - Proliferation of colonic lymphocytes in response to inflammatory cytokines is
lower in mice fed fish oil than in mice fed corn oil.
AB - The literature supports an association of chronic inflammation with the
development of tumors. The colon contains a specialized lymphocyte population
that may influence various stages of colon carcinogenesis. Dietary factors are
known to affect both inflammation and tumor development in this tissue. Diets
high in n-6 fatty acids are considered to be proinflammatory and tumor-promoting
whereas n-3 fatty acids are not. This study examined the proliferative response
of colonic lymphocytes (CL) from BALB/c mice fed a diet high in either corn oil
or menhaden oil when cultured in the presence of proinflammatory cytokines. CL
were isolated from mice fed one of the experimental diets and cultured in the
presence of anti-CD2, IL-1beta, IL-2, or TNF-alpha. Proliferation of CL in
culture was measured by BrdU incorporation. CL from mice fed the high n-3 diet
showed lower rates of proliferation following exposure to the inflammatory
cytokines than CL from mice fed the high n-6 diet. CL from the high n-3 group
showed the same proliferative potential as those from the n-6 diet group
following exposure to a combination of anti-CD2 and TNF. Results from this study
indicate that diets high in n-3 fatty acids slow the inflammatory response in the
colon as compared to diets high in n-6 fatty acids. The n-3 lipids do not appear
to compromise overall immune potential, however.
PMID- 10680590
TI - Suppression of azoxymethane-induced colonic aberrant crypt foci by a nitric oxide
synthase inhibitor.
AB - Nitric oxide synthase (NOS), an important bioregulator of a variety of biological
processes, is overexpressed in colonic tumors of humans and rodents. In this
study, effects of L-N(G)-nitroarginine methyl ester (L-NAME), a NOS inhibitor, on
development of aberrant crypt foci (ACF) induced by azoxymethane (AOM) in F344
male rats were investigated. Six-week-old male F344 rats were fed diets
containing 0 or 100 ppm L-NAME, and given s.c. injections of AOM at 15 mg/kg body
wt, once a week for 2 weeks. At 17 weeks of age, all animals were sacrificed and
their colons were evaluated for numbers of ACF. Feeding of 100 ppm L-NAME
inhibited the development of ACF in different sizes by 24-39%, those containing
four or more crypts being most markedly affected. Assessment of silver-stained
nucleolar organizer regions protein (AgNORs)/nucleus further revealed a 44%
reduction by administration of L-NAME. These results suggest that the NOS
inhibitor, L-NAME, may be an effective chemopreventive agent against colon
carcinogenesis due to depression of cell proliferation.
PMID- 10680591
TI - Anti-malignin antibody in serum and other tumor marker determinations in breast
cancer.
AB - In this study, 154 healthy volunteers and 76 patients were tested using the anti
malignin antibody in serum (AMAS) test. Of the 154 volunteers, three were AMAS
positive. After further examination, two were positive for cancer and one had a
history of ulcerative colitis. Tumor biopsies of 43 suspicious mammography
patients revealed that 32 were cancerous and 11 were benign by pathology. For the
cancer patients, 31/32 were positive for the AMAS test, while 4/11 of the
pathological benign cases were AMAS positive. In comparison to cancer antigen
tests, AMAS was more sensitive (97%) in detecting breast cancer than CEA (0%), CA
15-3 (10%), CA 19-5 (5%) or CA 125 (16%) in the same patients.
PMID- 10680592
TI - Absence of CD83-positive mature and activated dendritic cells at cancer nodules
from patients with hepatocellular carcinoma: relevance to hepatocarcinogenesis.
AB - Mature and activated dendritic cells (CD83-positive DCs) are essential for the
recruitment and survival of activated tumor-specific lymphocytes during
carcinogenesis. The frequencies of CD83 positive DCs were almost same in
peripheral blood from patients with hepatocellular carcinoma (HCC) and cirrhosis
of liver (LC). However, the numbers of CD83 positive DCs in liver tissues were
significant lower in HCC compared with LC (6.6+/-10.9 vs. 33.3+/-24 DCs/specimen,
P<0.05). Most importantly, there were no CD83-positive DCs at cancer nodules in
HCC. A role of infiltration of activated DCs in liver during hepatocarcinogenesis
is shown.
PMID- 10680593
TI - Summation of initiation activities of low doses of the non-hepatocarcinogen 1,2
dimethylhydrazine in the liver after carbon tetrachloride administration.
AB - Summation of initiation by low doses of the indirect-acting non-hepatocarcinogen,
1,2-dimethylhydrazine (DMH) after proliferative stimulation with a necrogenic
dose of carbon tetrachloride (CCl4) was investigated in terms of the induction of
glutathione S-transferase placental form (GST-P) positive liver cell foci. Cell
kinetics of liver after CCl4 i.g. treatment were examined with bromodeoxyuridine
(BrdU) labeling (experiment I). To assess the correlation between cell
proliferation and induction of liver cell foci, DMH (10 mg/kg i.g.) was
administrated to 7-week-old male F344 rats at 12, 24, 36, 48, 60, 96 h after CCl4
i.g. and initiated populations expanded using the resistant hepatocyte model
(experiment IIA). Subsequently, effects of repeated administration (10 mg/kg,
four times, i.g.) of DMH were compared with the results of a single
administration (40 mg/ kg, i.g.) with the same total dose (experiment IIB). In
experiments I and IIA, the numbers and areas of GST-P-positive foci increased
with the BrdU labeling index at the time of DMH treatment (maximum after 60 h).
In experiment HB, repeated exposure of DMH at 10 mg/kg, four times resulted in
significant (P<0.05) increase in number and area of GST-P-positive foci compared
with the single administration (40 mg/kg). Thus, multiple low dose treatments
during cell proliferation might be most effective for detection of weak
initiation activity.
PMID- 10680594
TI - Caspase-9 regulates cisplatin-induced apoptosis in human head and neck squamous
cell carcinoma cells.
AB - The aim of this study was to understand the molecular requirements for cisplatin
induced apoptosis in human head and neck squamous cell carcinoma (HNSCC) cell
death. Cisplatin induced apoptosis in HNSCC cell lines, HSC-2, HSC-3 and HSC-4 in
a dose-dependent manner. However, cisplatin did not induce the expression of Fas
ligand mRNA or upregulation of Fas protein. By caspase activation assays,
cisplatin induced Caspase-3 (Casp-3), -8 and -9 activation. In all three lines
tested, the use of a specific inhibitor of Casp-9 almost completely blocked
cisplatin-induced apoptosis, while the use of Casp-3 and -8 inhibitors resulted
in a partial blockade of cisplatin-induced apoptosis. Our results strongly
suggest that Casp-9-dependent apoptosis plays an important role in cisplatin
induced HNSCC apoptosis.
PMID- 10680595
TI - Aberrant DNA methylation precedes loss of heterozygosity on chromosome 16 in
chronic hepatitis and liver cirrhosis.
AB - The aim of this study was to examine the significance of aberrant DNA
methylation, the participation of which in genetic instability is controversial,
in hepatocarcinogenesis. The DNA methylation status of the region around the
promoter of the E-cadherin tumor suppressor gene, which is located on 16q22.1,
and the allelic status at the D16S421 locus, which is adjacent to the E-cadherin
locus, were examined using microdissected liver specimens from 38 hepatocellular
carcinoma (HCC) patients. Almost all of the non-cancerous liver tissues showed
histological findings compatible with chronic hepatitis and cirrhosis, which are
considered to be precancerous conditions. DNA hypermethylation was detected in
61% of the non-cancerous liver tissues. The incidence of DNA hypermethylation in
the non-cancerous liver tissues of patients with HCCs also showing DNA
hypermethylation (72%) was significantly higher than that of patients without DNA
hypermethylation in their HCCs (53%, P<0.05). Loss of heterozygosity (LOH) at the
D16S421 locus was detected in 35% of the non-cancerous liver tissues. The
incidence of LOH in the non-cancerous liver tissues of patients with HCCs also
showing LOH was 78%, whereas LOH was not detected in non-cancerous liver tissues
of patients without LOH in their HCCs. Fifty-two percent of the non-cancerous
liver tissues showed both or neither of DNA hypermethylation and LOH; the
incidence of DNA hypermethylation alone in noncancerous liver tissue was 41%. The
incidence of LOH alone in non-cancerous liver tissue (7%) was significantly lower
compared to those of the former two cases (P<0.0001). These data suggest that
aberrant DNA methylation participates in the precancerous stage of
hepatocarcinogenesis by preceding, or causing, LOH.
PMID- 10680596
TI - Trans-4-hydroxy-2-nonenal, an aldehydic lipid peroxidation product, lacks
genotoxicity in lacI transgenic mice.
AB - In order to cast light on the significance of lipid peroxidation products for
carcinogenesis, the lacI mutant frequency (MF), micronucleus induction and cell
proliferation were analyzed in lacI transgenic mice treated with trans-4-hydroxy
2-nonenal (HNE), a typical example. Male mice were ip injected with HNE at doses
of 0, 5 or 50 mg/kg bw and 48 h thereafter, peripheral blood was collected for
analyzing micronucleus induction. After 14 days, the mice were sacrificed to
allow tissue sampling for examination of lacI MF and cell proliferative activity.
Sixty percent of the mice given 50 mg/kg HNE died within 5 days after the
treatment, but no other mortalities were observed. Histopathologically, marked
pulmonary hemorrhage was found in the 50 mg/kg HNE group mice that survived until
day 14. Immunohistochemically, HNE-modified proteins were detected in their
alveolar macrophages. The HNE treatment did not increase lacI MF in the liver,
kidney and lung and no significant increase in micronucleus induction or cell
proliferation in major organs was found in either treatment. Moreover, no tumors
developed in the 5 mg/kg HNE-treated mice which survived until week 78. Our
results thus indicate that HNE lacks in vivo genotoxicity in lacI transgenic mice
even when lethal doses are applied.
PMID- 10680597
TI - Differential expression of an estrogen receptor messenger RNA containing exon 1'
sequences in MCF-7 breast cancer cell line stocks.
AB - The presence of an exon 1' sequence in the estrogen receptor alpha (ERalpha) mRNA
was detected in different stocks of ER-positive MCF-7 human breast cancer cells
by reverse transcriptase polymerase chain reaction (RT-PCR) and ribonuclease
protection analysis (RPA), but not by Northern blot analysis. This mRNA, however,
was not detectable in ERalpha-positive ZR-75-1 or ERalpha-negative MDA-MB-231
breast cancer cells, suggesting that exon 1' ER mRNA is differentially expressed
in some but not all ER-positive cell lines, and then, only at very low levels.
PMID- 10680598
TI - Analysis of highly frequent allelic loss region on distal chromosome 12 in murine
radiation-induced lymphomas.
AB - Recent genetic studies of tumorigenesis have strongly suggested an existence of
tumor suppressor gene(s) on murine chromosome 12 and human chromosome 14q32. We
previously described that putative tumor suppressor gene(s) might reside between
D12Mit53 and D12Mit233. We analyzed three genes, Tcl1, Yy1 and Tnfalphaip2, which
had been mapped around the region, as the candidates in radiation lymphomagenesis
of (BALB/c x MSM/Ms)F1 hybrid mice. The locus order and distances of the three
genes and microsatellite loci were estimated as follows: [centromere] - Tcl1-(>
or =0.085 cM)-D12Mit50-(0.085 cM)D12Mit132-(1.96 cM)D12Mit122-(0.085 cM)D12Mit53
(1.37 cM)-[D12Mit233,D12Mit279,Yy1]-(0.085 cM)-D12Mit181-(> or =0.17 cM)
Tnfalphaip2 - [telomere]. Allele losses at Tcl1, Yy1 genes and D12Mit233 were
observed in 94(45%), 143(68%) and 147(70%) of 210 lymphomas, respectively. In
semi-quantitative analysis of Yy1 mRNA levels by RT-PCR, kinetics of the yield of
the Yy1-cDNA-specific PCR products showed almost the same profiles among thymic
lymphomas with allelic loss at Yy1, lymphomas with both alleles retained and
normal thymus. These results suggest that Tcl1, Yy1 and Tnfalphaip2 genes are not
predominantly involved in radiation lymphomagenesis of mice. In further analysis
of the common allelic loss region, we found new loci, Y152pR1 and Y184pR2, from
YACs which located in the hot region between D12Mit53 and D12Mit233, and the
highest frequency of allelic loss (71%) was observed at the Y184pR2 locus. The
LOH patterns of individual lymphomas suggest that putative tumor suppressor
gene(s) lies between Y152pR1 and Y184pR2.
PMID- 10680599
TI - Involvement of retinoblastoma protein in p27Kip1-induced apoptosis.
AB - p27Kip1, a cyclin-dependent kinase (CDK) inhibitor, plays a critical role in cell
cycle regulation. Expression of p27Kip1 is shown to increase during apoptosis in
mammalian cells. Here, to directly address the role of p27Kip1 in apoptosis,
p27Kip1 is overexpressed in human SK-Hep1 hepatoma cells. This leads to apoptotic
cell death and this reduces protein, but not mRNA, levels of the retinoblastoma
(Rb). Consistently, accumulation of Rb protein blocks p27Kip1-mediated apoptosis.
These studies demonstrate an involvement of Rb in the apoptotic cell death which
is induced by overexpression of p27Kip1.
PMID- 10680600
TI - Guidelines for surveillance, prevention, and control of West Nile virus infection
-United States.
AB - The introduction of West Nile (WN) virus in the northeastern United States during
the summer and fall of 1999 raised the issue of preparedness of public health
agencies to handle sporadic and outbreak-associated vector-borne diseases. In
many local and state health departments, vector-borne disease capacity has
diminished. Because it is unknown whether the virus can persist over the winter,
whether it has already or will spread to new geographic locations, and the public
health and animal health implications of this introduction, it is important to
establish proactive laboratory-based surveillance and prevention and control
programs to limit the impact of the virus in the United States. On November 8 and
9, 1999, CDC and the U.S. Department of Agriculture (USDA) cosponsored a meeting
of experts representing a wide range of disciplines to review the outbreak and to
provide input and guidance on the programs that should be developed to monitor WN
virus activity and to prevent future outbreaks of disease. This report summarizes
the guidelines established during this meeting.
PMID- 10680601
TI - Accutane-exposed pregnancies--California, 1999.
AB - Accutane (Roche Laboratories, Nutley, New Jersey), known by the generic name
"isotretinoin," is a prescription oral medication approved by the Food and Drug
Administration (FDA) to treat severe, recalcitrant nodular acne. It is also a
known human teratogen that can cause multiple major malformations. Embryopathy
associated with the mother's exposure to isotretinoin during the first trimester
of pregnancy includes craniofacial, cardiac, thymic, and central nervous system
malformations . In response to FDA recommendations, the manufacturer began a
pregnancy-prevention program (PPP) in 1988 that included educational materials
for physicians and patients and offered women reimbursement for contraceptive
counseling by a physician. The PPP coordinators asked reproductive-aged women
being treated with isotretinoin to enroll voluntarily in the Boston University
Accutane Survey (BUAS). The total number of reproductive-aged women taking
isotretinoin in the United States is unknown; however, 454,273 women enrolled in
the BUAS from 1989 to October 1999. BUAS has estimated that 38%-40% of
reproductive-aged women taking isotretinoin chose to enroll in the survey (BUAS,
unpublished data, 1999). Although isotretinoin is contraindicated in pregnancy
and has a package label warning users to avoid pregnancy while taking it, exposed
pregnancies occur. Approximately 900 pregnancies occurred among BUAS enrollees
during 1989-1998 (BUAS, unpublished data, 1999). Roche Laboratories began direct
to-consumer print advertisements in 1996, added television and radio
advertisements to selected cities in 1997, and expanded the campaign to the
entire United States in 1998.
PMID- 10680602
TI - Update: raccoon rabies epizootic--United States and Canada, 1999.
AB - In 1977, an outbreak of raccoon rabies was detected in an area on the West
Virginia-Virginia border. Since then, the area affected by this distinct variant
of rabies virus associated with raccoons has spread to Ohio in the west and New
York, Pennsylvania, Vermont, New Hampshire, and Maine in the north. In addition,
the once separate epizootics of rabies among raccoons in the southeastern and mid
Atlantic states converged in North Carolina. In July 1999, the raccoon rabies
virus variant was reported from Ontario, Canada, on the New York border. This
report describes the spread of this epizootic of raccoon rabies through mid
Atlantic and northeastern states and into Canada.
PMID- 10680603
TI - Recommended childhood immunization schedule--United States, 2000.
AB - Each year, CDC's Advisory Committee on Immunization Practices (ACIP) reviews the
recommended childhood immunization schedule to ensure it remains current with
changes in manufacturers' vaccine formulations, revisions in recommendations for
the use of licensed vaccines, and recommendations for newly licensed vaccines.
This report presents the recommended childhood immunization schedule for 2000 and
explains the changes that have occurred since January 1999.
PMID- 10680604
TI - HPMA copolymer-modified avidin: immune response.
AB - Protein-polymer conjugates to be used in the pretargeted delivery of a
photosensitizer to cells were synthesized and characterized. Avidin was modified
by N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers bearing the
photosensitizer, mesochlorin e6 mono(N-2-aminoethylamide) (Mce6). Synthesis of
HPMA copolymer-avidin-Mce6 conjugates was carried out so that either
predominantly single point attachment or multipoint attachment of copolymer
chains to avidin would result. HPMA copolymer-avidin conjugates were used which
retained specific binding activity to a lower affinity biotin analog. Antigen
specific anti-avidin immune response was shown to be reduced six-fold in some
HPMA copolymer-avidin conjugates when compared to immune response to unmodified
avidin. HPMA copolymer itself was shown to elicit a very low (IgM) immune
response.
PMID- 10680605
TI - Protein A immobilization and HIgG adsorption onto porous/nonporous and swellable
HEMA-incorporated polyEGDMA microspheres.
AB - Both non swellable and swellable poly(EGDMA/HEMA) microbeads were produced by
suspension copolymerization. These microbeads were modified by immobilization of
a spacer-arm (hexamethylene diamine (HMDA)) and protein A. The optimal values for
modifications were as follows: sodium periodate concentration, 1.0 mgml(-1); HMDA
concentration, 4 mgml(-1); and glutaraldehyde concentration, 0.070 microgml(-1).
Adsorption of protein A onto the plain and periodate oxidized poly(EGDMA/HEMA)
microbeads were very close to each other, and were 0.01-0.02 mg protein A on the
1-g Microbeads I and II, respectively. Protein A immobilization on
poly(EGDMA/HEMA) microbeads were studied at different temperatures, times, and
pHs using single protein solution containing different amounts of proteins. The
optimal values for immobilization were as follows: the initial protein A
concentration, 0.1 mgml(-1); temperature, 25 degrees C; pH, 9.5; and
immobilization time, 120 min. Incorporation of protein A resulted in 1.420 and
1.825 mg protein A on the 1-g Microbeads I and II, respectively. HIgG adsorption
capacity on the protein A-incorporated poly(EGDMA/HEMA) microbeads is 27 and 35
mg HIgGg(-1) polymer for Microbeads I and II, respectively.
PMID- 10680606
TI - Controlled release of antihypertensive drug from the interpenetrating network
poly(vinyl alcohol)-guar gum hydrogel microspheres.
AB - Poly(vinyl alcohol)-guar gum interpenetrating network microspheres were prepared
by cross-linking with glutaraldehyde. Nifedipine, an antihypertensive drug, was
loaded into these matrices before and after cross-linking to study its release
patterns. The extent of cross-linking was analyzed by Fourier transform infrared
spectroscopy and differential scanning calorimetry. Furthermore, the microspheres
were characterized for drug entrapment efficiency, particle size, transport of
water into the matrix and drug release kinetics. Scanning electron microscopic
photographs confirmed the spherical nature and surface morphology. The mean
particle size of the microspheres was found to be around 300 microm. The
molecular transport phenomenon, as studied by the dynamic swelling experiments,
indicated that an increase in cross-linking affected the transport mechanism from
Fickian to non-Fickian. The in vitro release study indicated that the release
from these microspheres is not only dependent upon the extent of cross-linking,
but also on the amount of the drug loaded as well as the method of drug loading.
PMID- 10680607
TI - Effect of ionic strength on the loading efficiency of model polypeptide/protein
drugs in pH-/temperature-sensitive polymers.
AB - In this report, the effect of ionic strength on the loading efficiency of three
model polypeptide/protein drugs, namely angiotensin II, insulin, and cytochrome
c, in pH- and temperature-sensitive terpolymers of poly(NIPAAm-co
butylmethacrylate-co-acrylic acid) (poly(NIPAAm-co-BMA-co-AA)) has been
investigated. Loading efficiency of polypeptides in pH-/temperature-sensitive
beads composed of poly(NIPAAm-co-BMA-co-AA) terpolymer is predominantly governed
by hydrophobic interactions, both nonspecific surface interactions and/or
specific interactions (binding pockets) between the protein and the polymer
molecules. Thus, loading efficiency increases with ionic strength. However, as
ionic strength increases further, polymer deswelling (collapse), which is also
controlled by hydrophobic forces, becomes more pronounced, and consequently, a
higher fraction of water is squeezed out during bead formation and the loading
efficiency starts to decrease.
PMID- 10680608
TI - Immunogenicity of antigens in boiled alginate microspheres.
AB - Vaccine efficacy can be enhanced by delivery of antigens in synthetic
microspheres. The process of antigen incorporation into microspheres can expose
fragile antigens to damaging conditions, such as high temperatures, and to
bacterial contamination. Maintenance of immunogenicity of several antigens and
reduction of bacterial load in alginate microspheres following boiling was
evaluated. Mice were immunized subcutaneously, initially and again 21 days later,
with either non-boiled or boiled microspheres containing ovalbumin (OVA), a
culture supernatant vaccine of Pasteurella haemolytica (PHV), or a potassium
thiocyanate extract of P. multocida (PTE). Serum samples were obtained prior to
immunization and at the time of euthanasia 28 days later. Culture of microspheres
showed that boiling completely eliminated aerobic bacterial growth for OVA
containing microspheres, and reduced growth by a factor of 10(4) for PTE
microspheres. More bacteria were cultured after boiling than before for PHV
microspheres. ELISA performed on serum and intestinal lamina propria explant
supernatants showed that immunogenicity of PHV microspheres was not altered by
boiling. Boiled OVA microspheres were still able to stimulate a significant serum
IgG anti-OVA titer in mice, but boiled PTE microspheres completely lacked
immunogenicity. Elispot assays of spleens showed that only PHV microspheres were
able to retain immunogenicity after boiling. Results indicate that boiling is not
an effective means for reducing the bacterial load of alginate microspheres and
that the process is associated with a diminution of vaccine immunogenicity.
PMID- 10680609
TI - Modification of the adhesive properties of collagen by covalent grafting with RGD
peptides.
AB - Collagen, either alone or in combination with other materials, is an important
natural biomaterial that is used in a variety of tissue-engineering applications.
Cell adhesion and migration of cells within collagen-based biomaterials may be
controlled by modifying the adhesive properties of collagen. Furthermore,
spatially controlling the adhesiveness of the collagen may allow controlled
localization or redistribution of cells. A method is presented for covalently
coupling peptides that contain the well-characterized arginine-glycine-aspartic
acid adhesion sequence directly to type I collagen monomers prior to
fibrillogenesis. A heterobifunctional coupling agent was used to create stable
amide and disulfide bonds with the lysine residues of the collagen monomers and
the cysteine termini of the peptide molecules, respectively. The degree of
conjugation could be controlled by changing the reaction conditions (ratios of
reactants added and the length of incubation). The microstructure and gelation
times of gels composed of covalently modified collagen were similar to those of
unmodified gels. Cell adhesion on adsorbed monolayers of modified collagen was
quantified using a well-established clonal cell line (K1735 murine melanoma).
Cell adhesion was found to increase with both increasing degree of conjugation
and increasing ratio of modified to unmodified collagen.
PMID- 10680610
TI - Polymerization and surface analysis of electrically-conductive polypyrrole on
surface-activated polyester fabrics for biomedical applications.
AB - A new synthetic route is reported for the synthesis and covalent bonding of
electrically conductive polypyrrole to a poly(ethylene terephthalate) fabric. It
involves a three-step process including surface phosphorylation and graft
polymerization from the gaseous phase. In the first step, the fibre surfaces are
activated using phosphorus trichloride. Then, 1-(3-hydroxypropyl) pyrrole is
introduced and grafted to the phosphorus chloride to create an ester bond between
the fibres and the pyrrole. Finally, the pyrrole-grafted fibres are dipped in an
aqueous FeCl3 catalyst and exposed to pyrrole monomer vapor for the final
polymerization. This last step creates an electrically conductive polypyrrole
layer covalently linked to the poly(ethylene terephthalate) fibres. ESCA analysis
indicates a high degree of phosphorylation and grafting of the anchor molecules.
Scanning electron microscopy reveals an overall smooth and uniform surface
coating of polypyrrole on the polyester fibres. The use of ATR-FTIR spectroscopy
is not able to distinguish between polypyrrole-coated and non-coated fabrics
because of the extremely thin polypyrrole layer. Measurements of dynamic surface
wetting indicated that the polypyrrole-coated fabric is more hydrophilic than the
untreated control. With values for surface resistivity in the range 10(4)-10(5)
ohmz/square, such polypyrrole-coated fabrics are considered attractive candidates
for biomedical applications.
PMID- 10680611
TI - Novel bifunctional polymer with reactivity and temperature sensitivity.
AB - To introduce reactive groups into temperature-responsive polymeric chains of
poly(N-isopropylacrylamide) (PIPAAm), IPAAm is copolymerized with other monomer
such as acrylic acid (AAc). IPAAm homopolymer exhibited temperature-responsive
properties and phase transition at 32 degrees C, however, the lower critical
solution temperature (LCST) of the IPAAm-AAc copolymer shifts to a higher
temperature and the phase transition becomes insensitive with increasing AAc
content. To achieve a useful bifunctional copolymer containing both reactivity
and temperature-sensitivity, we assumed that the homopolymer-like structure in
the polymer chain would be required to maintain a sensitive temperature response
with functional groups. Therefore, we designed a reactive monomer, 2
carboxyisopropylacrylamide (CIPAAm), and investigated its copolymerization with
IPAAm. The important characteristic of the poly(IPAAm-co-CIPAAm) structure is
that it was composed of the same polymer backbone and isopropylamide groups and
some additional carboxyl groups. The transmittance measurement of the polymer
aqueous solution revealed that phase transition of IPAAm-co-CIPAAm random
copolymer occurred within a very narrow temperature range in pH 6.4, 7.4, and
also even 9.0 phosphate buffered solution. These profiles were almost same as
that of IPAAm homopolymer. While, under the same conditions, phase transition
properties of poly(IPAAm-co-AAc)s solution were considerably influenced by small
AAc content. We succeeded with the preparation of bifunctional polymer that
possessed reactive functional groups and very sensitive response to temperature
change.
PMID- 10680612
TI - In situ atomic force microscopic observation of albumin adsorption onto phase
separated organosilane monolayer surface.
AB - A mixed (n-octadecyltrichlorosilane (OTS)/[2
(perfluorooctyl)ethyl]trichlorosilane (FOETS)) monolayer was prepared on the
water subphase and was subsequently immobilized onto the silicon wafer surface by
chemical bonds. Atomic force microscopic (AFM) observation of the mixed
(OTS/FOETS) monolayer revealed the formation of a phase-separated structure. In
situ AFM observation of the adsorption behavior of bovine serum albumin (BSA)
onto the mixed (OTS/FOETS) monolayers, successfully showed the adsorption
behavior of BSA onto the phase-separated surface. It also revealed that in the
case of pH 7.5, BSA was preferentially adsorbed onto the lower surface free
energy FOETS phase of the mixed (OTS/FOETS) monolayer. On the other hand, BSA was
adsorbed homogeneously onto the OTS and FOETS phases at the isoelectric point of
BSA (pI 4.7). These results indicate that the preferential adsorption of BSA onto
the FOETS phase in the mixed (OTS/FOETS) monolayer system may be due to: (1) the
minimization of interfacial free energy between a monolayer surface and an
aqueous solution; and (2) the electrostatic repulsion among BSA molecules bearing
negative charges.
PMID- 10680613
TI - Mechanical bioeffects from diagnostic ultrasound: AIUM consensus statements.
American Institute of Ultrasound in Medicine.
PMID- 10680614
TI - Section 2--definitions and description of nonthermal mechanisms. American
Institute of Ultrasound in Medicine.
PMID- 10680615
TI - Section 3--selected biological properties of tissues: potential determinants of
susceptibility to ultrasound-induced bioeffects. American Institute of Ultrasound
in Medicine.
AB - Although harmful side effects have not been reported in humans associated with
the clinical application of continuous wave (CW) ultrasound (typical of
therapeutic applications) or pulsed ultrasound (typical of diagnostic
applications), bioeffects have been reported in nonhuman mammalian species with
both waveforms. Bioeffects have been reported in organ systems that have tissues
associated with well-defined gas bodies, such as lung and intestine, and in
tissues not associated with well-defined gas bodies, such as nervous tissue,
liver, kidney, and reproductive tissues. Lesions in tissues with well-defined gas
bodies include hemorrhage in lung and intestine; lesions in tissues without well
defined gas bodies include cell and tissue destruction and necrosis with tissue
specific hemorrhage in nervous tissue, liver, kidney, and reproductive tissues.
Studies suggest that there are unique differences in the responses of tissues to
CW and pulsed ultrasound among animal species and within a species based on age
or stage of development. Data from reference materials covering the anatomy and
histology of animal tissues indicate that important structural differences exist
among species and within a species based on age or stage of development. These
structural differences and how they influence the responses of tissues and organs
to ultrasound appear to be focused on the serosal surfaces (protective coverings)
of these organs. Such surfaces include, but are not limited to, the visceral
pleura of the lung and the visceral peritoneum of all abdominal organs. The
thickness and composition (e.g., structural fiber type, collagen, or elastic
fibers) of these surfaces and their contiguous internal structural units, such as
septa and trabecula, also appear to be important in determining the
susceptibility of a tissue or organ to ultrasound-induced damage. Although data
exist that support the hypothesis that there are species differences in
susceptibility to CW ultrasound-induced lung hemorrhage, data from studies using
pulsed ultrasound are less abundant but suggest that species differences in
susceptibility to pulsed ultrasound-induced lung hemorrhage may also possibly
exist. Species differences in susceptibility to ultrasound-induced lung
hemorrhage appear inversely related to the thickness of the visceral pleura of
the lung. Although pulsed ultrasound can induce hemorrhage in the intestine of
mice, there are no data from intestinal studies currently available suggesting
there are species differences in susceptibility to pulsed ultrasound. There
exists, for the intestine, information similar to that reported in the lung,
which documents innate tissue and organ differences among mammalian species that
could influence susceptibility to pulsed ultrasound. The analysis,
interpretation, and speculation regarding bioeffects and tissue properties
documented in this section and the conclusions presented likely will mature and
evolve as new information becomes available through additional in vivo bioeffects
research.
PMID- 10680617
TI - Section 5--nonthermal bioeffects in the absence of well-defined gas bodies.
AB - The purpose of this section is to describe bioeffects that occur in those
instances in which gas bodies are not known to commonly be present. This is in
contrast to situations such as lung and intestine, where bioeffects have been
proposed to be associated with the known presence of gas (Section 4). In
addition, this section does not include those studies in which microbubbles (such
as ultrasound contrast agents) are purposefully introduced (Section 6).
Therefore, this section includes a large collection of bioeffects that may be
related to cavitation activity or may not be related at all to the presence of
gas bodies. The intention is to provide an overall summary of the information
currently available that pertains to those situations in which gas bodies are not
known to be present and to provide this information in support of conclusions and
recommendations on this subject.
PMID- 10680616
TI - Section 4--bioeffects in tissues with gas bodies. American Institute of
Ultrasound in Medicine.
AB - Several animal models have exhibited thresholds for petechial hemorrhage in lung
within the current output of diagnostic ultrasound systems. In addition,
thresholds for damage in the mouse intestine due to diagnostic pulses of
ultrasound have been explored. The implications for human lung and intestinal
exposure to clinical diagnostic ultrasound have not yet been determined. In this
section, the data supporting the thresholds of petechial hemorrhage in these
organ systems and the morphological observations will be reviewed. The potential
mechanical mechanisms of damage to these organs due to diagnostic ultrasound also
will be reviewed. Special attention will be given to the occurrence of inertial
cavitation both in vitro and in vivo. The effects of ultrasound parameters, age,
and species on the threshold for damage in animal models will be explored.
PMID- 10680621
TI - Visual signal detection in structured backgrounds. III. Calculation of figures of
merit for model observers in statistically nonstationary backgrounds.
AB - Models of human visual detection have been successfully used in computer
generated noise. For these backgrounds, which are generally statistically
stationary, model performance can be readily calculated by computing the index of
detectability d' from the noise power spectrum, the signal profile, and the model
template. However, model observers are ultimately needed in more real
backgrounds, which may be statistically non-stationary. We investigated different
methods to calculate figures of merit for model observers in real backgrounds
based on different assumptions about image stationarity. We computed performance
of the nonpre-whitening matched-filter observer with an eye filter on mammography
and coronary angiography for an additive or a multiplicative signal. Performance
was measured either by applying the model template to the images or by computing
closed-form expressions with various assumptions about image stationarity.
Results show first that the structured backgrounds investigated cannot be
considered stationary. Second, traditional closed-form expressions of
detectability calculated from the noise power spectra with the assumption of
background stationarity lead to erroneous estimates of model performance. Third,
the most accurate way of measuring model performances is by directly applying the
model template on the images or by computing a closed-form expression that does
not assume image stationarity.
PMID- 10680622
TI - Visual signal detection in structured backgrounds. IV. Figures of merit for model
performance in multiple-alternative forced-choice detection tasks with correlated
responses.
AB - Many investigators are currently developing models to predict human performance
in detecting a signal embedded in complex backgrounds. A common figure of merit
for model performance is d', an index of detectability that can be mathematically
related to the proportion correct (Pc) when the responses of the model are
Gaussian distributed and statistically independent. However, in many multiple
alternative forced-choice (MAFC) detection tasks, the target appears in one of M
different locations within an image. If the image contains slow spatially varying
luminance changes (low-pass noise), the pixel luminance values at the possible
signal locations are correlated and therefore the model/human responses to the
different locations might also be correlated. We investigate the effect of
response correlations on model performance and compare different figures of merit
for these conditions. Our results show that use of the standard d' index of
detectability assuming statistical independence can lead to erroneous
underestimates of Pc and misleading comparisons of models. We introduce a novel
figure of merit d'(r) that takes into account response correlations and can be
used to accurately estimate Pc. Furthermore, we show that d'(r) can be readily
related to the standard index of detectability d' by d'(r) = d'/square root of (1
- r), where r is the correlation between the responses in any MAFC detection
task. We illustrate the use of the theory by computing figures of merit for two
linear models detecting a signal in one of four locations within medical image
backgrounds.
PMID- 10680623
TI - Color signals in natural scenes: characteristics of reflectance spectra and
effects of natural illuminants.
AB - Multispectral images of natural scenes were collected from both forests and coral
reefs to represent typical, complex scenes that might be viewed by modern
animals. Both reflectance spectra and modeled visual color signals in these
scenes were decorrelated spectrally by principal-component analysis. Nearly 98%
of the variance of reflectance spectra and color signals can be described by the
first three principal components for both forest and coral reef scenes, which
implies that three well-designed visual channels can recover almost all of the
spectral information of natural scenes. A variety of natural illuminants affects
color signals of forest scenes only slightly, but the variation in ambient
irradiance spectra that is due to the absorption of light by water has dramatic
influences on the spectral characteristics of coral reef scenes.
PMID- 10680618
TI - Section 6--mechanical bioeffects in the presence of gas-carrier ultrasound
contrast agents. American Institute of Ultrasound in Medicine.
AB - This review addresses the issue of mechanical ultrasound-induced bioeffects in
the presence of gas carrier contrast agents (GCAs). Here, the term "contrast
agent" refers to those agents that provide ultrasound contrast by being composed
of microbubbles, encapsulated or not, containing one or more gases. Provided in
this section are summaries on how contrast agents work, some of their current
uses, and the potential for bioeffects associated with their presence in an
ultrasonic field.
PMID- 10680624
TI - Relational color constancy in achromatic and isoluminant images.
AB - Relational color constancy, which refers to the constancy of perceived relations
between surface colors under changes in illuminant, may be based on the
computation of spatial ratios of cone excitations. As this activity need occur
only within rather than between cone pathways, relational color constancy might
be assumed to be based on relative luminance processing. This hypothesis was
tested in a psychophysical experiment in which observers viewed simulated images
of Mondrian patterns undergoing colorimetric changes that could be attributed
either to an illuminant change or to a nonilluminant change; the images were
isoluminant, achromatic, or unmodified. Observers reliably discriminated the two
types of changes in all three conditions, implying that relational color
constancy is not based on luminance cues alone. A computer simulation showed that
in these isoluminant and achromatic images spatial ratios of cone excitations and
of combinations of cone excitations were almost invariant under illuminant
changes and that discrimination performance could be predicted from deviations in
these ratios.
PMID- 10680625
TI - Chromatic contrast sensitivity: the role of absolute threshold and gain constant
in differences between the fovea and the periphery.
AB - A model of foveal achromatic and chromatic sensitivity [Vision Res. 36, 1597
(1996)] was extended to the peripheral visual field. Threshold-versus-illuminance
functions were analyzed to determine effects of eccentricity on absolute
thresholds and gain constants of chromatic and luminance mechanisms. The
resulting peripheral model successfully predicted peripheral contrast sensitivity
as a function of wavelength, for both white and 500-nm backgrounds. We conclude
that the short-wavelength-sensitive cone opponent mechanism may mediate
thresholds in Sloan's notch in the normal periphery and that interpretation of
reduced chromatic sensitivity in the periphery requires an explicit model of how
eccentricity affects both the gain constant and the absolute threshold.
PMID- 10680626
TI - Role of perceptual organization in chromatic induction.
AB - Color matches between two small patches were made in a display containing ten
larger regions of different chromaticities. The spatial organization of the ten
regions was varied while keeping constant the immediate surround of each patch as
well as the space-average chromaticity of the entire stimulus. Different spatial
arrangements were designed to alter the perceptual organization inferred by the
observer without changing the ensemble of chromaticities actually in view. For
example, one arrangement of the ten regions was consistent with five surfaces
under two distinct illuminations, with one edge within the display (an "apparent
illumination edge") dividing the stimulus into two areas, one under illuminant A
and the other under illuminant C. Another spatial arrangement had the ten regions
configured to induce an observer to infer ten surfaces under a single
illumination. When the ten regions were arranged with an apparent illumination
edge, the patch within the area of illuminant C was perceived as bluer than when
the same patch and immediate surround were presented without an apparent
illumination edge. The results are accounted for by positing that observers group
together regions sharing the same inferred illumination, with a consequent effect
on color perception: A fixed patch-within-surround shifts in hue and saturation
toward the perceived illumination. We suggest that the change in color perception
in a complex scene that results from a difference in real illumination may be
caused by the inferred illumination at the perceptual level, not directly by the
physical change in the light absorbed by photoreceptors.
PMID- 10680619
TI - Section 7--discussion of the mechanical index and other exposure parameters.
American Institute of Ultrasound in Medicine.
AB - There have been long-term efforts to identify a threshold pressure for the onset
of inertial cavitation under conditions relevant to ultrasound in medicine.
Before the introduction of the output display standard [AIUM/NEMA, 1992a],
quantities such as the spatial peak pulse average intensity (I(SPPA)), and,
earlier, Im, the spatial peak intensity averaged over the largest half-cycle,
were used to give a measure of the potential of a cavitation-based bioeffect due
to an acoustic field. Relatively early in the Output Display Standard development
effort, the Food and Drug Administration indicated a need for a superior
indicator for the potential for cavitation-related bioeffects, initiating a
search for such an index. The following paragraphs give an outline of the steps
used to develop the Mechanical Index, its relevance as a potential bioeffects
indicator, and some information on other exposure parameters involved in
bioeffects research.
PMID- 10680627
TI - Invariant cone-excitation ratios may predict transparency.
AB - Cone-excitation ratios for pairs of surfaces are almost invariant under changes
in illumination and offer a possible basis for color constancy [Proc. R. Soc.
London Ser. B 257, 115 (1994)]. We extend this idea to the perception of
transparency on the basis of the close analogy between the changes in color
signals that occur for surfaces when the illumination changes and the changes in
color signals when the surfaces are covered by a filter. This study presents
measurements and simulations to investigate the conditions under which cone
excitation ratios are statistically invariant for physically transparent systems.
The invariance breaks down when the spectral transmission of the filters is low
at some or all wavelengths. We suggest that cone-excitation ratios might be
useful to define the stimulus conditions necessary for the perception of
transparency.
PMID- 10680628
TI - Image restoration with the Viterbi algorithm.
AB - The Viterbi algorithm (VA) is known to given an optimal solution to the problem
of estimating one-dimensional sequences of discrete-valued pixels corrupted by
finite-support blur and memoryless noise. A row-by-row estimation along with
decision feedback and vector quantization is used to reduce the computational
complexity of the VA and allow the estimation of two-dimensional images. This
reduced-complexity VA (RCVA) is shown to produce near-optimal estimation of
random binary images. In addition, simulated restorations of gray-scale images
show the RCVA estimates to be an improvement over the estimates obtained by the
conventional Wiener filter (WF). Unlike the WF, the RCVA is capable of
superresolution and is adaptable for use in restoring data from signal-dependent
Poisson noise corruption. Experimental restorations of random binary data
gathered from an optical imaging system support the simulations and show that the
RCVA estimate has fewer than one third of the errors of the WF estimate.
PMID- 10680629
TI - Polarization and statistical analysis of scenes containing a semireflector.
AB - We present an approach to recover scenes deteriorated by reflections off a
semireflecting medium (e.g., a glass window). The method, based on imaging
through a polarizer at two or more orientations, separates the reflected and
transmitted scenes and determines which is which. We analyze the polarization
effects, taking into account internal reflections within the medium. The scene
reconstruction requires the estimation of the orientation (inclination and tilt
angles) of the transparent (invisible) surface. The inclination angle is
estimated by seeking the value that leads to the minimal mutual information of
the estimated scenes. The limitations and the consequences of noise and angle
error are discussed, including a fundamental ambiguity in the determination of
the plane of incidence. Experimental results demonstrate the success of angle
estimation and consequent scene separation and labeling.
PMID- 10680630
TI - High-diffraction-efficiency pseudorandom encoding.
AB - Pseudorandom encoding (PRE) is a statistics-based procedure in which a pure-phase
spatial light modulator (SLM) can yield, on the average, the prescribed
diffraction pattern specified by the user. We seek to combine PRE with the
optimization of an aperture-based target function. The target function is a fully
complex input transmittance, unrealizable by a phase-only SLM, that generates a
prescribed light intensity. The optimization is done to increase the diffraction
efficiency of the overall process. We compare three optimization methods-Monte
Carlo simulation, a genetic algorithm, and a gradient search-for maximizing the
diffraction efficiency of a spot-array generator. Calculated solutions are then
encoded by PRE, and the resulting diffraction patterns are computer simulated.
Details on the complexity of each procedure are furnished, as well as comparisons
on the quality, such as uniformity of the output spot array.
PMID- 10680620
TI - Section 8--clinical relevance. American Institute of Ultrasound in Medicine.
PMID- 10680631
TI - Propagation-invariant wave fields with finite energy.
AB - Propagation invariance is extended in the paraxial regime, leading to a
generalized self-imaging effect. These wave fields are characterized by a finite
number of transverse self-images that appear, in general, at different
orientations and scales. They possess finite energy and thus can be accurately
generated. Necessary and sufficient conditions are derived, and they are
appropriately represented in the Gauss-Laguerre modal plane. Relations with the
following phenomena are investigated: classical self-imaging, rotating beams,
eigen-Fourier functions, and the recently introduced generalized propagation
invariant wave fields. In the paraxial regime they are all included within the
generalized self-imaging effect that is presented. In this context we show an
important relation between paraxial Bessel beams and Gauss-Laguerre beams.
PMID- 10680632
TI - Dispersion control with use of long-period fiber gratings.
AB - Chirped long-period fiber gratings are analyzed for management of dispersion in
optical fiber communications systems. A ray model is used to derive simple
analytic expressions that describe the transmission, chromatic delay, and
dispersion properties of chirped long-period fiber gratings. A numerical model
based on coupled-mode theory is used to verify the accuracy of the analytic
expressions and explore design issues of the chirped long-period grating. With
certain reasonable restrictions, chirped long-period gratings are found to be a
viable and desirable alternative to existing dispersion compensation techniques.
PMID- 10680633
TI - Elastic light scattering from single microparticles on a femtosecond time scale.
AB - Experimentally measured and theoretically calculated elastic light-scattering
spectra from single microparticles illuminated by 100-fs pulses are presented.
Although in the theoretical calculation only a single incoming femtosecond laser
pulse was used, the spectral behavior of scattered light shows all the features
seen in the experimental spectrum from many femtosecond pulses, including
morphology-dependent resonances (MDR's). The good agreement between experimental
and theoretical elastic light-scattering data has stimulated a theoretical
investigation of the time-dependent behavior of the elastically scattered light
from a single microparticle on a femtosecond time scale. Since the spatial pulse
length of the incoming laser pulse is smaller than the particle circumference,
the temporal behavior of reflection, diffraction, refraction, and coupling into
MDR's can be distinguished. Since the time-dependent scattering is strongly
dependent on particle size, refractive index, and pulse chirp, it may be possible
to encode several bits of information into a single laser pulse and therefore to
increase optical data communication rates.
PMID- 10680634
TI - Rigorous vector diffraction of electromagnetic waves by bidimensional photonic
crystals.
AB - We present a numerical study of bidimensional photonic crystals with an emphasis
on the behavior of the gaps versus the polarization and the conicity of the
incident plane wave. We use a rigorous modal theory of diffraction at oblique
incidence by a set of arbitrarily shaped parallel fibers. This theory allows the
study of the refractive properties of bidimensional photonic crystals. We develop
a heuristic method of homogenization that allows us to predict the position of
the gaps and their behavior with respect to the polarization and the conicity
angle. With this homogenization scheme, we also present some important elements
for obtaining full gaps.
PMID- 10680635
TI - Characteristic properties of Mueller matrices.
AB - A complete and minimum set of necessary and sufficient conditions for a real 4 x
4 matrix to be a physical Mueller matrix is obtained. An additional condition is
presented to complete the set of known conditions, namely, the four conditions
obtained from the nonnegativity of the eigenvalues of the Hermitian matrix H
associated with a Mueller matrix M and the transmittance condition. Using the
properties of H, a demonstration is also presented of Tr(M(T)M) = 4m(2)00 as
being a necessary and sufficient condition for a physical Mueller matrix to be a
pure Mueller matrix.
PMID- 10680636
TI - Polarization of almost-plane waves.
AB - The general polarization behavior of almost-plane waves, in which the electric
field varies slowly over a circular pupil, is considered, on the basis of an
axial Hertz potential treatment and expansion in Zernike polynomials. The
resultant modes of a circular aperture are compared with the well-known waveguide
(or optical fiber) modes and Gaussian beam modes. The wave can be decomposed into
partial waves of electric and magnetic types. The modes for a square pupil are
also considered. The particular application of the effect on polarization of
focusing the waves is discussed. Another application discussed is the Fresnel
reflection from a dielectric interface, it being shown that the Fresnel
reflection alters the relative strength of the electric and magnetic components.
PMID- 10680637
TI - Structure of the set of paraxial optical systems.
AB - The set of paraxial optical systems is the manifold of the group of symplectic
matrices. The structure of this group is nontrivial: It is not simply connected
and is not of an exponential type. Our analysis clarifies the origin of the
metaplectic phase and the inherent limitations for optical map fractionalization.
We describe, for the first time to our knowledge, an image girator and a cross
girator whose geometric and wave implementations are of interest.
PMID- 10680638
TI - Aberration and the Strehl ratio.
AB - An exact expression is derived for the Strehl ratio as a function of the minimum
root-mean-square aberration value that may produce it. The result is applicable
to any aperture and is shown to imply a similar expression for the Strehl ratio
as a function of the minimum amplitude range of the aberration.
PMID- 10680639
TI - The prevalence of C677T mutation in the methylenetetrahydrofolate reductase gene
and its association with venous thrombophilia in Taiwanese Chinese.
AB - C677T mutation of the methylenetetrahydrofolate reductase gene remains a
controversial risk factor for venous thrombosis in Whites. The prevalence of
methylenetetrahydrofolate reductase C677T genotype and its association with
vascular thrombosis are not well established in Chinese population. We conducted
a case-control study to investigate the prevalence of methylenetetrahydrofolate
reductase C677T gene mutation and its association with venous thrombophilia in
Taiwanese Chinese. The subjects consisted of 112 venous thrombophilic patients
and 125 healthy controls, with similar age (p=0.08) and sex (p=0.58). The
prevalent rates of C/T heterozygote were 32.8 and 44.6%; whereas those of T/T
homozygote were 6.4 and 8.0% in the controls and patients, respectively. Neither
C/T heterozygote (odds ratio, 1.7; 95% confidence interval, 1.0-3.0, p=0.05] nor
T/T homozygote (odds ratio, 1.4; 95% confidence interval, 0.5-4.0, p=0.5) was
significantly associated with venous thrombosis. Even when only subjects (52
patients and 107 controls) with normal inhibitor protein levels were analyzed,
the association of T/T homozygote with venous thrombosis remained insignificant
(p=0.06) with an odds ratio (95% confidence interval) of 3.4 (0.99-11.7). We
concluded that, in Taiwanese Chinese, methylenetetrahydrofolate reductase C677T
mutation is a common genetic mutation, but T/T homozygote is not a significant
risk factor for venous thrombophilia.
PMID- 10680640
TI - Factors affecting the first recurrence of noncardioembolic ischemic stroke.
AB - Studies of the factors affecting the first recurrence of ischemic stroke have
reported inconsistent findings. Types of initial stroke and the racial
differences in study samples are among the explanations that may account for this
inconsistency. The aims of this study were to estimate the cumulative recurrence
rates of noncardioembolic ischemic stroke and identify the factors that influence
the first recurrence of noncardioembolic ischemic stroke in the Taiwanese Chinese
population. Four hundred and sixty-six patients with noncardioembolic ischemic
stroke from thirteen hospitals in Taiwan were followed up in this study to
ascertain first recurrence of noncardioembolic ischemic stroke between October
1992 and April 1995. The Kaplan-Meier method was used to estimate the cumulative
recurrence rate. The Cox regression model was used to ascertain the significant
factors affecting the first recurrence of noncardioembolic ischemic stroke. The
overall cumulative recurrence rate was 10.5% (49/466) from the follow-up period
of 30 months. After adjustment for age, sex, treatment modes, and variables
pertinent to blood pressure, the site of brain lesion remained a significant
factor. The relative risk of first recurrence for the basal ganglion vs. the
region of middle cerebral artery was 3.06 (95% CI: 1.29-7.26). The brain lesion
site was demonstrated to be an independent predictor of risk for the first
recurrence of noncardioembolic ischemic stroke among the Taiwanese Chinese
population. Whether this finding was also seen in other populations should be
corroborated in future research.
PMID- 10680641
TI - Markers of activated hemostasis and fibrinolysis in patients with pulmonary
malignancies: comparison of plasma levels in central venous and pulmonary venous
blood.
AB - Malignancy frequently is accompanied by activated coagulation and fibrinolysis
indicating a hypercoagulable state. The purpose of our study was to estimate the
contribution of local tumor-induced mechanisms to the activation of hemostasis
and fibrinolysis. In a prospective study, we compared the plasma levels of
thrombin-antithrombin complexes, prothrombin fragment 1+2, and D-dimers in blood
samples that simultaneously were drawn from the superior vena cava and the
pulmonary vein of a tumor-bearing pulmonary lobe. Samples from the superior vena
cava were drawn before operation and served as controls. After thoracotomy, a
second group of samples was simultaneously taken from the pulmonary veins of the
tumor-bearing lobe and the superior vena cava. Forty-five patients with pulmonary
malignancies were included (25 adenocarcinomas and 20 squamous cell carcinomas).
There were no significant differences of thrombin-antithrombin complexes,
prothrombin fragment 1+2, and D-dimers levels in patients suffering from
adenocarcinoma and from squamous cell carcinoma. Intraoperatively, prothrombin
fragment 1+2 and D-dimers levels were markedly increased when compared with the
preoperative values (p<0.0001). There was no increase of thrombin-antithrombin
complexes levels due to the operative traumatization. Prothrombin fragment 1+2,
thrombin-antithrombin complexes, and D-dimers plasma levels were significantly
higher in the pulmonary venous blood than in the blood simultaneously drawn from
the superior vena cava (p<0.0001). Our findings indicate that malignant lung
tumors directly contribute to the activation of hemostasis and fibrinolysis in
these clinical settings.
PMID- 10680642
TI - NO reduces PMN adhesion to human vascular endothelial cells due to downregulation
of ICAM-1 mRNA and surface expression.
AB - Reperfusion damage is largely due to the adherence of polymorphonuclear
leukocytes to the endothelium initiated by adhesion molecule upregulation. The
reduced endothelial nitric oxide release during ischemia may be involved in the
upregulation of intercellular adhesion molecule 1. In this study, we tested if
nitric oxide donors suppress polymorphonuclear leukocyte adherence to activated
endothelial cells by inhibition of the intercellular adhesion molecule 1 surface
expression. Confluent human umbilical vein endothelial cells were stimulated with
tumor necrosis factor alpha (300 U/mL) after preincubation with increasing
concentrations of the nitric oxide donors CAS 1609 (0.005-5 mM/L) and 3-(4
morpholinyl)-sydnonimine (0.01-1 mM/L). Intercellular adhesion molecule 1 surface
expression was measured in a cell surface enzyme-linked immunosorbent assay,
intercellular adhesion molecule 1 mRNA by Northern analysis. Human saphenous vein
endothelial cells were transfected with the inducible nitric oxide synthase gene
and stimulated with tumor necrosis factor alpha (300 U/mL). Fluorescein green
labeled polymorphonuclear leukocytes adhering to activated human umbilical vein
endothelial cells/human saphenous vein endothelial cells were quantified by
epifluorescent microscopy. The intercellular adhesion molecule 1 surface
expression of activated human umbilical vein endothelial cells/human saphenous
vein endothelial cells was significantly diminished to 40 to 60% of the maximum
after treatment with CAS 1609, 3-(4-morpholinyl)-sydnonimine, or transfection
with the inducible nitric oxide synthase gene. Intercellular adhesion molecule 1
mRNA was diminished by CAS 1609 and 3-(4-morpholinyl)-sydnonimine in the same
manner. The functional relevance of our data was shown by reduction of
polymorphonuclear leukocyte adherence to activated human umbilical vein
endothelial cells/human saphenous vein endothelial cells following treatment with
CAS 1609 and 3-(4-morpholinyl)-sydnonimine or transfection with inducible nitric
oxide synthase. Tumor necrosis factor-induced polymorphonuclear leukocyte
adherence was abolished by blocking antibody against intercellular adhesion
molecule 1. Thus, exogenous or endogenous substitution of nitric oxide diminishes
the expression of endothelial intercellular adhesion molecule 1 and its mRNA
following tumor necrosis factor alpha stimulation. This results in a reduced
polymorphonuclear leukocyte adherence to activated endothelium.
PMID- 10680643
TI - Effect of DT-TX 30, a combined thromboxane synthase inhibitor and thromboxane
receptor antagonist, on retinal vascularity in experimental diabetes mellitus.
AB - Combined thromboxane synthase inhibitors and thromboxane receptors antagonists
have been shown to have a beneficial effect on different models of thrombosis in
vivo. We studied the action of one of these compounds (DT-TX 30) compared with
dazoxiben (a thromboxane synthase inhibitor) on retinal vascularity in
streptozotocin-diabetic rats. Ten nondiabetic animals were treated with isotonic
saline, 30 (10 animals per group) were given 0.4, 4, and 8 mg kg(-1) per day of
DT-TX 30 (p.o.) and 30 (10 animals per group) were given 10, 50, and 100 mg kg(
1) per day of dazoxiben (p.o.) over a 90-day study period. DT-TX 30 caused a dose
dependent decrease of platelet aggregation and thromboxane B2 synthesis. There
was an increase of 9, 65, and 166% in the synthesis of prostacyclin after
treatment with 0.4, 4, and 8 mg kg(-1) per day, respectively. Retinal vascularity
increased in 51, 72, and 182% of animals in response to the three doses used.
Synthesis of prostacyclin and the degree of retinal vascularity showed a linear
correlation (r2=0.6528,p<0.00001). Dazoxiben, at doses that inhibited thromboxane
synthesis as much as DT-TX 30, increased prostacyclin production and retinal
vascularity with less potency than DT-TX 30. In conclusion, the antagonism of
thromboxane receptors may be an important additional effect to the inhibition of
thromboxane synthase in the prevention of ischemic retinal lesions in
experimental diabetes.
PMID- 10680644
TI - A recombinant antibody-targeted plasminogen activator with high affinity for
activated platelets increases thrombolytic potency in vitro and in vivo.
AB - To increase thrombolytic specificity of urokinase (uPA), we engineered a
recombinant chimeric plasminogen activator SZ51Hu-scuPA, which consists of a
humanized monoclonal antibody (SZ-51Hu) specifically against P-selectin on
activated human platelet and a single-chain urokinase (scuPA). The cDNA, encoding
scuPA amino acids 1-411, was inserted in 5' end to 3' end orientation immediately
after the CH3 of SZ-51Hu heavy-chain sequence in the expression vector
alphaLys30. The resulting construct alphaLys30-SZ51VH/Hu-scuPA was used to
transfect into SP2/0 murine myeloma cell line, which was pretransfected with
SZ51Hu light chain. The fusion protein SZ51Hu-scuPA was expressed at 5 mg/L in
the supernatant of cell culture. The fusion protein purified by affinity
chromatography had a molecular weight of 160 kDa with fibrinolytic activity of
39,000 IU/mg and its affinity to activated human platelet was 67% of the parent
murine mAb SZ-51. The thrombolytic property of the fusion protein was first
characterized in an in vitro system, which consists of a 125I-fibrin-labeled
human plasma clot containing different concentrations of human platelets
suspended in citrated human plasma. Fifty percent lysis was reached with SZ51Hu
scuPA in 1 hour at a concentration of 20 IU/mL or in 2 hours at a concentration
of 10 IU/ mL, which was much faster than uPA at the same concentration. The
maximal lysis of the clots by SZ51Hu-scuPA was 4.1 to 8.4 times more potent than
that by uPA. The fusion protein was further characterized in the hamster
pulmonary embolism model with clots prepared from fresh platelet-rich human
plasma containing 125I-labeled fibrinogen. The thrombolytic activity of SZ51
scuPA was 3.9 times more potent than that of uPA at 2,000 IU/kg in this model.
Almost no significant fibrinogen breakdown was observed either in vitro and in
vivo.
PMID- 10680645
TI - Platelet aggregation during abdominal surgery in an experimental pig model: the
effects of presurgical antibiotic protocols and volume replacement with
hydroxyethyl starch.
AB - The effect of presurgical antibiotic protocols in combination with hemodilution
on platelet aggregation was studied. Thirty pigs were randomly assigned to three
groups. Group 1 received amoxicillin/clavulanic acid, group 2
metronidazole+cefuroxime, and group 3, as a control, sodium chloride. They
underwent laparotomy, massive blood loss, and volume replacement with
hydroxyethyl starch 200, followed by an anaphylactoid reaction. Platelet
aggregation was measured by the turbidometric method. Neither antibiotic
protocols had any effect on platelet aggregation as compared with the control
group. In all three groups, aggregation to ADP and collagen was significantly
reduced after volume replacement with hydroxyethyl starch. In contrast, the
sensitivity to the aggregating effects of collagen was increased as assessed by a
higher frequency of responses to low concentrations of collagen and a shortened
latency of the aggregation response after collagen addition. Further in vitro
studies revealed that dilution of plasma with hydroxyethyl starch specifically
induced the changes seen after in vivo volume replacement. The results suggest
that the plasma substitute hydroxyethyl starch 200 increases the sensitivity to
low doses of collagen, an effect never described before and considered of
clinical relevance.
PMID- 10680646
TI - Detection of mononuclear cells as the source of the increased tissue factor mRNA
in the liver from lipopolysaccharide-treated rats.
AB - Tissue factor (TF) triggers the coagulation cascade reaction in vivo.
Overexpression of TF mRNA is one leading cause of disseminated intravascular
coagulation and thrombosis-related organ failure. In response to
lipopolysaccharide (LPS) stimulation, various cell types can produce TF mRNA in
vitro. However, there is currently no agreement on what types of cells in the
liver overexpress TF mRNA after LPS treatment. For the first report, we found the
increased TF mRNA with reverse transcription-polymerase chain reaction (RT-PCR),
and confirmed a fourfold increase (p<0.001 vs. control, t-test) of the TF mRNA
level with RT-competitive PCR in the liver of LPS-treated (2.0 mg/kg i.v.
injection) rats. There was no significant difference in the glyceraldehyde-3
phosphate dehydrogenase mRNA level between LPS-treated rats and control rats. To
clarify the localization and cellular source of LPS-induced TF mRNA, we performed
in situ hybridization analysis with [35S]-labeled oligonucleotides probes, which
we originally designed. We detected intense signals of TF mRNA in mononuclear
cells but not in endothelial cells around the hepatic vein of LPS-treated rats.
In this study, we showed that the TF mRNA level induced by LPS treatment, which
may indicate mononuclear cells associated, significantly increased in the liver
of rats. These results will provide circumstantial support for the therapeutic
strategy that mononuclear cell should be one of the target cells to be treated in
the early phase of disseminated intravascular coagulation in the liver, and that
the need to suppress its overexpression of TF mRNA is essential for preventing
hypercoagulable condition.
PMID- 10680647
TI - Effect of methylenetetrahydrofolate reductase 677 C-T, 1298 A-C, and 1317 T-C on
factor V 1691 mutation in Turkish deep vein thrombosis patients.
AB - Possible effect of three common mutations in (MTHFR 677 C-T; 1317 T-C; 1298 C-A)
and FV 1691 G-A mutation was studied in Turkish patients with thrombosis and
compared with normal controls. The case-control study included 68 patients with
the diagnosis of deep vein thrombosis and 66 controls, consecutively selected
among subjects without personal and familial history of atherothrombosis.
Patients with deep vein thrombosis were selected if Doppler ultrasonography was
positive. Only, the comparison of factor V 1691 G-A mutation revealed
statistically significant difference in control (6.06%) and deep vein thrombosis
(23.5%) group. Risk assessment of double prothrombotic gene alterations revealed
only FV 1691 G-A mutation as an independent risk factor for thrombosis (odds
ratio 4.7 [1.5-15.0]), but our data suggested that MTHFR 677 has effect on its
own (odds ratio 1.97 [0.6-2.7]) but may have synergy with FV 1691 G-A (odds ratio
8.12 [2.0-25.3]). However, MTHFR 1298 A-C and 1317 T-C does not have any effect;
furthermore, being heterozygote at two different loci or homozygosity at least in
a locus for 677 and 1298 revealed a significant increase (odds ratio 9 and 24
[1.3-59.3 and 2.3-240.3]) between these two groups.
PMID- 10680648
TI - Free radicals are involved in cancer procoagulant-induced platelet activation.
PMID- 10680649
TI - Vaccination of neonatal colostrum-deprived calves against Pasteurella haemolytica
A1.
AB - Colostrum-deprived Holstein calves were vaccinated at 2 and 4 wk of age with a
Pasteurella haemolytica A1 culture supernatant vaccine to determine whether
active immune responses and protection could be induced in this age group in the
absence of maternal antibodies. All calves responded to vaccination with high
titers of IgM antibodies to capsular polysaccharide within 1 wk of primary
vaccination. Mean titers of IgG1 and IgG2 antibodies to this antigen increased
significantly by 2 wk after secondary vaccination, but peak antibody titers were
low. All of the vaccinated calves seroconverted with production of leukotoxin
neutralizing antibodies, but peak antibody titers were low. Vaccinated calves
experienced considerable lung damage after experimental challenge, but survival
rate, clinical scores, and percent lung involvement were significantly better
than those of control (placebo-injected) calves.
PMID- 10680650
TI - Prevention of edema disease in pigs by passive immunization.
AB - The effect of treatment with verotoxin 2e (VT2e) specific antiserum was evaluated
in 3 Danish pig herds with edema disease (ED). The antiserum was prepared by
immunizing horses with a VT2e toxoid. The study was performed as a randomized
blind field trial with parallel treatment and control groups. There were
approximately 50 piglets in each group in each of the 3 herds and 741 piglets
were included in the study (244 from herd A, 249 from herd B, and 247 from herd
C). Treatment groups received 2, 4, or 6 mL anti-VT2e serum intramuscularly the
day before weaning. Control groups were treated with 6 mL normal horse serum or 6
mL RPMI 1640 medium as placebo. All pigs that died in the trial period (1 d
before weaning to 44 d after weaning) were examined pathologically and
microbiologically. Mortality due to ED, mortality due to other causes, and
adverse effects due to treatment were recorded. As there was no mortality due to
ED, herd B was excluded from statistical calculations on mortality. The content
of horse antibodies specific to VT2e in serum from pigs was analyzed in an
indirect ELISA. A higher dose of anti-VT2e serum was reflected in higher optical
density values in the indirect ELISA. Transient adverse reactions, seen as
vomiting, ataxia, and cyanosis, occurred shortly after the injection of horse
serum in 1.5% of the pigs, and one pig died. There were no statistically
significant differences in mortality due to other causes among the 3 treatment
groups in herds A and C. Only pigs from which F18+, VT2e+, ST-, LT- hemolytic E.
coli (0139 or O-rough) was isolated were diagnosed as dead due to ED. Deaths due
to ED in the control groups were 8.1% and 12.0% in herds A and C, respectively,
compared with 0% and 0.7% in the corresponding serum groups. The difference
between treatment and control groups was statistically significant (P<0.0001). It
was not possible to establish an effect of dose (2, 4, or 6 mL) of anti-VT2e
serum, because only one pig died of ED in the treatment groups. It was concluded
that passive immunization by intramuscular injection of a VT2e-specific antiserum
can be used for protecting piglets against ED.
PMID- 10680651
TI - Subtypes of intimin among non-toxigenic Escherichia coli from diarrheic calves in
Brazil.
AB - One hundred and five strains of Escherichia coli that were isolated from calves
with diarrhea in the state of Sao Paulo, Brazil, and were negative for
enterotoxins and cytotoxins, were examined for the eae gene. Four (3.8%) strains
were positive by polymerase chain reaction (PCR) and were shown to produce
intimin by using Western blot with specific antiserum against the conserved N
terminal region of intimin. Subtyping of the intimins was done by PCR with
specific primers and by Western blot with specific antisera against the C
terminal variable region of the protein. Three of these isolates (O?:H11, O26:H-,
O123:H1) produced the beta subtype of intimin, and the 4th (0103:H2) produced
intimin that was not typable. The 0103:H2 and the O26:H-isolates adhered to HEp-2
cells with diffuse adherence and localized-like adherence patterns, respectively.
The other strains did not adhere to HEp-2 cells. To our knowledge, this is the
first report of the occurrence of a subtype of intimin described for human
enteropathogenic E. coli among bovine diarrheogenic E. coli. It is also the first
report from Brazil demonstrating the presence of bovine E. coli harboring the eae
gene.
PMID- 10680652
TI - Experimental aerosol transmission of Actinobacillus pleuropneumoniae to pigs.
AB - In order to demonstrate the possible role of aerosol in the transmission of
Actinobacillus pleuropneumoniae, an experiment including 18 specific pathogen
free (SPF), 10-week-old piglets, randomly distributed into 2 adjacent units, was
carried out. In these facilities, air was forced through absolute filters to
prevent any contact with infectious agents. During the first 6 d post
inoculation, the 2 units were connected by a rectangular opening and the air
circulation was forced by the ventilation system from unit A (inoculated pigs) to
unit B (non-inoculated pigs). The A. pleuropneumoniae strain (biovar 1 serovar 9)
was isolated in France from an outbreak of porcine pleuropneumonia. Two different
infecting doses, 10(7) cfu/animal and 10(8) cfu/animal, were inoculated by
intranasal route in 6 pigs of unit A. The infection spread quickly from the
inoculated pigs to the non-inoculated pigs. Clinical signs were acute during the
4 d post inoculation: hyperthermia, respiratory distress and, sometimes, death (6
pigs of the unit A and 2 pigs of the unit B). All pigs seroconverted against A.
pleuropneumoniae serovar 9 within 2 weeks. Lung lesions were severe: fibrinous
pleurisy and lung hemorrhages in the acute stage, pleural adherences and focal
pulmonary necrosis in the chronic stage. Actinobacillus pleuropneumoniae was
isolated from the tonsils and/or lungs in 16 animals. It could be also isolated
from the air of the experimental unit. This study showed that A. pleuropneumoniae
was readily transmitted through aerosol over a distance of at least 2.5 m.
PMID- 10680653
TI - Assessment of various treatments to reduce carriage of Salmonella in swine.
AB - In this study, different strategies to reduce carriage of Salmonella spp. in pigs
were evaluated. Probiotics, prebiotics, vaccination, and acidification of
drinking water were assessed as means of reducing Salmonella. Acidification of
water, use of egg yolk-specific immunoglobulins, and vaccination with an
endotoxin vaccine did not reduce Salmonella excretion in experimentally infected
pigs. A reduction of Salmonella in the colonization of mesenteric lymph nodes was
observed with the use of bambermycins and a live attenuated vaccine. A reduction
in the shedding of S. Typhimurium was also observed after supplementation with
fructooligosaccharides in drinking water. The use of probiotics and prebiotics
appeared to change the pig fecal bacterial flora as indicated by Gram staining of
smears from rectal swabs.
PMID- 10680654
TI - Development of an indirect enzyme-linked immunosorbent assay for the detection of
leptospiral antibodies in dogs.
AB - Serology plays an important role in the diagnosis of leptospirosis. Few
laboratories have the resources, expertise, or facilities to perform the
microscopic agglutination test (MAT). Thus, there is a need for a rapid and
simple serological test that could be used in any diagnostic laboratory. In this
study, a genus-specific, heat-stable antigenic preparation from Leptospira
interrogans serovar pomona was used in an enzyme-linked immunosorbent assay
(ELISA) for the detection of leptospiral antibodies in dog sera. This antigenic
preparation reacted with rabbit antisera against L. interrogans serovars
bratislava, autumnalis, icterohaemorrhagiae and pomona and with rabbit antiserum
against L. kirschneri serovar grippotyphosa. The ELISA showed a relative
specificity of 95.6% with 158 dog sera which were negative at a dilution of 1:100
in the MAT for serovars pomona, bratislava, icterohaemorrhagiae, autumnalis,
hardjo, and grippotyphosa. The relative sensitivity of this assay with 21 dog
sera that revealed serovars MAT titres of > or =100 to different serovars was
100%. This assay is easily standardized, technically more advantageous than MAT,
and uses an antigenic preparation that can be routinely prepared in large
amounts. It was concluded that this ELISA is sufficiently sensitive test to be
used as an initial screening test for the detection of leptospiral antibodies in
canine sera, with subsequent confirmation of positive test results with the MAT.
PMID- 10680655
TI - Detection of antibodies to equine arteritis virus by a monoclonal antibody-based
blocking ELISA.
AB - A potent ELISA antigen was prepared from equine arteritis virus (EAV) by
differential centrifugation of EAV-infected cell culture fluid, followed by
solubilization of the preparation by Triton X-100 treatment. Using this antigen
and a mouse monoclonal antibody against the G(L) protein of EAV, a reliable
blocking ELISA (bELISA) was developed for the detection of EAV antibodies in
equine sera. The bELISA was evaluated using a total of 837 test serum samples.
The relative sensitivity (n = 320) of the bELISA compared to the serum
neutralization (SN) test was 99.4%. The bELISA appears to be a highly specific
test, the specificity of which did not appear to be adversely affected by
previous exposure of horses to non-EAV-containing biologicals. Of 119 serum
samples, 21 from horses without any history of exposure to EAV and 98 from
racetrack Thoroughbreds, 118 were negative in the SN test and bELISA. One sample
was SN-negative but suspicious with the bELISA. Based on testing 465 SN-negative
field samples and 52 SN-negative samples from experimental horses, and excluding
any sera giving a suspicious reaction, the relative specificity of the bELISA was
97.7%. Samples should be examined undiluted and diluted 1/10 in the bELISA
because the testing of sera of high neutralizing antibody titer may be affected
by a prozone-like phenomenon. The bELISA is a more rapid and cost-efficient test
than the SN test for the detection of EAV antibodies in equine sera.
PMID- 10680656
TI - PCR detection and characterization of type-2 porcine circovirus.
AB - A polymerase chain reaction (PCR) assay was developed for detecting porcine
circovirus (PCV). The assay readily detected type-2 PCV (PCV-2) and type-1 PCV
(PCV-1). The PCR primers were designed based on DNA sequences conserved in all
reported PCV genomes. Type 1 PCV and type 2 PCV both produced 438 bp
amplification products, which were easily identified and differentiated from one
another by restriction fragment length polymorphism (RFLP) analysis. Porcine
circovirus was detected in 55% (931/1693) of randomly tested pigs with various
clinical signs and lesions, most of which were difficult to differentiate from
those associated with porcine reproductive and respiratory syndrome (PRRS). The
PCR products from all positive clinical samples were identified by RFLP to be
only PCV-2; DNA tested by PCR was extracted directly from one or more of lung,
mesenteric or mediastinal lymph nodes, and tonsil. Type 2 PCV was also detected
in 6% (2/34) of DNA extracted directly from semen of randomly chosen healthy
boars. Positive PCR reactions from 554 diseased pigs were characterized by RFLP
and categorized into 5 different profiles (A-E), of which 82.8% were PCV-2A
(456/554), 3.0% were PCV-2B (17/554), 9.9% were PCV-2C (55/554), 1.1% were PCV-2D
(6/554), and 3.2% were PCV-2E (18/554). The complete genomic nucleotide sequences
of PCV-2A, B, C, D, and E were determined and found to have at least 95% homology
compared with one another and with all other PCV-2 found in the GenBank database.
All PCV-2 had less than 76% homology with PCV-1. This PCR assay will hopefully be
useful to veterinary diagnostic laboratories for routine testing and surveillance
of infection with PCV-2. The RFLP profiling system might be useful for
preliminary characterization and identification of PCV isolates and might also
benefit studies on the molecular epidemiology of PCV.
PMID- 10680657
TI - Effect of aflatoxin on performance, hematology, and clinical immunology in lambs.
AB - Twenty-four female lambs were intoxicated with a diet contaminated with 2 ppm
aflatoxin for a period of 37 d. Twelve lambs were maintained as the control
group. After this period, the lambs were left for 35 d without aflatoxin in their
feed. Performance, hematology and clinical immunology were examined in the
intoxicated lambs. A non-significant decrease in body weight was observed in the
intoxicated lambs during the intoxication period, whereas a significant decrease
(P<0.001) in average daily gain was noted on the last day of intoxication and
during the clearance period. No significant differences were observed in
erythrocyte count, white blood cell count or differential leukocyte count between
the groups. Bacteriostatic activity of the serum was lower in the intoxicated
lambs, however, there was no effect on serum opsonic activity. Phagocytosis by
the neutrophils was higher during the intoxication period and the levels of IgG
were elevated in the intoxicated lambs. In vivo cellular immunity was assessed by
intradermal injection of phytohemagglutinin; the response was lower during
intoxication period. These results indicate that a lowering in the average daily
gain was the most sensitive indicator of aflatoxicosis in lambs, and that the
immune response was altered, which could render the animals more susceptible to
infectious diseases.
PMID- 10680658
TI - Correlation of periovulatory serum and fecal progestins in the domestic dog.
AB - This study was initiated to determine the relationship between canine ovarian
steroids detected in serum and feces during the periovulatory interval in
domestic dogs, and to examine the feasibility of a non-invasive method to
estimate the time of ovulation in canid species. When bitches (n = 14) were
observed to enter proestrus (based on vulvar enlargement or serosanguineous
vaginal discharge), paired daily serum and fecal samples were collected for a 15-
to 20-day period and stored at -20 degrees C. After extraction, progestin
concentrations in both substrates were measured using an established enzyme
immunoassay procedure. All samples were aligned to Day 0, the first day in which
fecal progestins reached a sustained rise above 100 ng/g feces. Mean fecal
progestin concentrations increased in parallel with mean serum progesterone
values (r = 0.78), rising from 44.6+/-2.6 ng/g feces to 409.6+/-90.9 ng/g feces,
and 5.4+/-0.9 nmol/L to 81.2+/-18.5 nmol/L, on Day -5 and Day 5, respectively.
Individual fecal progestin concentrations varied markedly, but plotted against
serum progesterone concentrations demonstrated correlation coefficients ranging
from 0.41 to 0.97 (P<0.05). These results demonstrate that sequential changes in
domestic dog serum ovarian steroid concentrations are paralleled in the feces,
and that it is feasible to non-invasively monitor individual progestin changes in
the periovulatory interval using fecal hormone analysis.
PMID- 10680659
TI - Comparative cardiopulmonary effects of carfentanil-xylazine and medetomidine
ketamine used for immobilization of mule deer and mule deer/white-tailed deer
hybrids.
AB - Three mule deer and 4 mule deer/white-tailed deer hybrids were immobilized in a
crossover study with carfentanil (10 microg/kg) + xylazine (0.3 mg/kg) (CX), and
medetomidine (100 microg/kg) + ketamine (2.5 mg/kg) (MK). The deer were
maintained in left lateral recumbency for 1 h with each combination. Deer were
immobilized with MK in 230+/-68 s (mean +/- SD) and with CX in 282+/-83 seconds.
Systolic, mean and diastolic arterial pressure were significantly higher with MK.
Heart rate, PaO2, PaCO2, pH, and base excess were not significantly different
between treatments. Base excess and pH increased significantly over time with
both treatments. Both treatments produced hypoventilation (PaCO2 > 50 mm Hg) and
hypoxemia (PaO2 < 60 mm Hg). PaO2 increased significantly over time with CX. Body
temperature was significantly (P<0.05) higher with CX compared to MK. Ventricular
premature contractions, atrial premature contractions, and a junctional escape
rhythm were noted during CX immobilization. No arrhythmias were noted during MK
immobilization. Quality of immobilization was superior with MK, with no observed
movement present for the 60 min of immobilization. Movement of the head and limbs
occurred in 4 animals immobilized with CX. The major complication observed with
both of these treatments was hypoxemia, and supplemental inspired oxygen is
recommended during immobilization. Hyperthermia can further complicate
immobilization with CX, reinforcing the need for supplemental oxygen.
PMID- 10680660
TI - Effects of vitamins A and E on superoxide production and intracellular signaling
of neutrophils in Holstein calves.
AB - The effects of vitamin A and vitamin E treatment on superoxide (O2-) production
of neutrophils and their intracellular signaling, including intracellular Ca2+,
protein kinase C (PKC), and tyrosine kinase (TK), were examined in Holstein
calves. After treatment with vitamin A, heat-aggregated IgG (H-agg.IgG)-induced
O2- production in neutrophils ranged from 3.7+/-0.4 to 4.3+/-0.9 nmol (mean +/-
SD), and it was significantly (P<0.05) higher than that in the control calves.
Opsonized zymosan (OPZ)-induced O2- production was similar with that of control
calves. Intracellular signaling of neutrophils in vitamin A-treated calves was
enhanced compared with that of control calves when stimulated with H-agg. IgG,
but not with OPZ. After treatment with vitamin E, H-agg.IgG- and OPZ-induced O2-
production of neutrophils ranged from 4.2+/-0.8 nmol to 5.4+/-0.5 nmol and from
7.8+/-0.6 nmol to 8.1+/-0.4 nmol (mean +/- SD), respectively, and they were
significantly (P<0.05) higher than those in control calves. Intracellular
signaling was also enhanced compared with that of control calves. These results
suggested that the effects of vitamin A and E treatment on O2- production were
correlated to changes in intracellular signaling of neutrophils in Holstein
calves.
PMID- 10680661
TI - Does portal hypertension contribute to the pathogenesis of gastric ulcer
associated with liver cirrhosis?
AB - The prevalence of gastric ulcers in patients with liver cirrhosis is increased
compared with that in the general population, and portal hypertension may
contribute to the increased risk of gastric ulcer in cirrhosis patients.
Aggressive factors involved in the pathogenesis of gastric ulcer are diminished
in association with portal hypertension. In contrast, most of the important
gastric mucosal defense mechanisms are shown to be impaired in portal
hypertension; many of these mechanisms are also found to be altered in patients
with liver cirrhosis. Portal hypotensive treatment with propranolol reduces
ethanol-induced gastric mucosal damage in portal hypertensive rats and improves
endoscopic signs of portal hypertensive gastropathy in cirrhosis patients.
Together, these findings suggest portal hypertension-induced impairment of the
gastric mucosal defenses to be an important factor in the pathogenesis of gastric
ulcer in patients with liver cirrhosis. Prospective studies of portal pressure
reducing procedures, such as pharmacotherapy with propranolol, and their effect
on the incidence of gastric ulcer in cirrhosis patients are needed to confirm
this suggestion.
PMID- 10680662
TI - Feasibility of optical coherence tomography for high-resolution imaging of human
gastrointestinal tract malignancies.
AB - Optical coherence tomography (OCT) is a new imaging technology which can perform
high-resolution, cross-sectional imaging of the internal microstructure of
biological tissues. OCT is analogous to ultrasound, except that it measures the
intensity of back-reflected infrared light rather than sound waves. OCT performs
two- and three-dimensional imaging of tissue microstructure in situ and in real
time. It can achieve image resolutions approaching the cellular level over
approximately the same imaging depths as a conventional biopsy. In this article
we examine the feasibility of OCT for high-resolution imaging of gastrointestinal
malignancies with ex-vivo imaging of normal and pathologic microstructures.
Tissue, both normal and neoplastic, was obtained from patients undergoing
surgical resection after an initial diagnosis of a gastrointestinal malignancy.
The tissue samples were imaged prior to fixation using a laboratory OCT system.
The OCT system consists of a fiber optic-based Michelson interferometer, a
commercially available amplified superluminscent light source, and a computer for
data acquisition. The images were subsequently compared with histological cross
sections corresponding to the imaged areas. The stratified squamous epithelium of
the normal esophagus was clearly visible in the OCT images and contrasted to the
disorganized and non-uniform nature of the mucosal layers of Barrett's esophagus
and squamous carcinoma. The columnar epithelial morphology as well as other
mucosal structures in normal colon were distinctly visible using OCT. In
contrast, disorganization of the normal mucosal layers and ulcerative lesions
were identified in tissues from ulcerative colitis and adenocarcinoma of the
colon. The ability of OCT to image tissue microstructure at high resolutions
makes it a potentially powerful technology for minimally invasive assessment of
the gastrointestinal tract and the evaluation of early neoplastic changes.
PMID- 10680663
TI - Altered vascular response to acetylcholine in conditions of endothelial damage in
the isolated perfused rat stomach.
AB - To examine the mechanism of stress ulcers and the relation between endothelium
derived relaxing factor (EDRF)/NO and gastric mucosal blood flow (GMBF), we used
an isolated perfused rat stomach model and studied the effects of an autonomic
nerve activator, nitric oxide synthase (NOS) synthesis, and an EDRF/NO inhibitor
on gastric blood circulation. Rats were divided into four groups according to
pretreatment: (1) control; (2) those given gossypol, a drug provoking endothelial
cell damage; (3) those given L-N monomethylarginine (L-NMMA), a specific
inhibitor of EDRF/NO; and (4) those subjected to water-immersion stress. Using
this model we collected the perfusion fluid from the portal vein at various time
points. After administration of acetylcholine, the perfusion flow increased in
the control group, but perfusion flow showed no change in the L-NMMA group. On
the other hand, the perfusion flow decreased in the gossypol and water-immersion
stress groups. The perfusion fluid from the control group contained cGMP, but
this substance was absent in the perfusion fluid of the other experimental
groups. We considered that increased cGMP in the fluid came from endothelial
cells. We presume that the presence of EDRF/NO is essential for the control of
GMBF and that from the viewpoint of gastric ulcers, the lack of EDRF/NO may be an
important factor in the decrease of GMBF in the early stages of water-immersion
stress.
PMID- 10680664
TI - Clinical importance of n-3 fatty acid-rich diet and nutritional education for the
maintenance of remission in Crohn's disease.
AB - Elemental diet (ED) therapy has been established as primary therapy for Crohn's
disease, and home enteral nutrition (HEN) has been reported to control relapse at
a dose of more than 30kcal/kg of ideal body weight. However, a decrease in ED
compliance with long-term use is becoming problem. We developed an n-3 fatty acid
rich diet and carried out nutritional education specifically for Crohn's disease
patients using HEN to facilitate compliance and to improve their nutritional
status. After the introduction of this n-3 rich diet, disease activity was not
altered, and nutritional status, especially serum n-3 fatty acid levels,
improved. The remission periods in patients with poor compliance seemed to be
prolonged by the nutritional education. Thus, a n-3 rich diet in combination with
nutritional education specific for Crohn's disease patients is very important for
the in maintenance of high compliance and for maintaining nutritional balance.
PMID- 10680665
TI - Changes of liver fibrosis in chronic hepatitis C patients with no response to
interferon-alpha therapy: including quantitative assessment by a morphometric
method.
AB - The aim of this study was to evaluate the antifibrotic effect of interferon (IFN)
alpha in chronic hepatitis C (CH-C) patients with no response to IFN-alpha
therapy. We studied 76 patients (46 men, 30 women; mean age, 55.6 years) who
received IFN-alpha intramuscularly, at a total close of 480 to 880MU for 6 months
(group A). As a control group, we studied 50 patients (32 men and 18 women; mean
age, 58.5 years) with CH-C who received medication other than IFN (ie, Strong-Neo
Minophagen C, ursodeoxycholic acid, and a herbal medicine, Sho-saiko-to [TJ-9])
and who had persistent alanine aminotransferase (ALT) elevation (group B). All
patients were subdivided into three subgroups according to different patterns of
ALT changes during the observation period, ie, (a) persistent ALT level < 60IU/ 1
(below about twice the upper limit of the normal range), (b) persistent ALT level
> or = 60IU/1, (c) ALT levels other than (a) and (b). Liver biopsy was performed
within 6 months prior to IFN therapy and more than 6 months after IFN therapy,
while two liver biopsies were performed during therapy in group B. Liver fibrosis
was compared between two specimens by staging. When the fibrosis stage was the
same in the two specimens, we determined whether the fibrosis had improved or
worsened by comparing the fibrotic ratio, ie, the ratio of the area of fibrosis
to the area of the entire liver tissue specimen, calculated using computed
graphic software. Serum aminoterminal peptide of type III procollagen (PIIIP)
levels were measured on the day of the liver biopsy and their mean yearly changes
were compared between the two groups. Improvement of liver fibrosis was found in
12% to 30% of patients in each ALT subgroup and in 24% of all patients in group A
and there were no significant differences in liver fibrosis in comparison with
findings in of group B when assessed by staging alone. However, these percentages
rose to 59% to 75% and 66%, respectively, when liver fibrosis was assessed by the
fibrotic ratio together with staging, resulting in a significant difference in
fibrosis between groups A and B in total (P < 0.01). The mean yearly changes in
serum PIIIP levels in each subgroup and in all patients in group A were below
zero, indicating a tendency to improvement of fibrosis after IFN therapy, while
these changes in group B were all above zero, except for subgroup (c).
Improvement of fibrosis after IFN therapy was found in 15 of 24 patients (64%)
whose ALT changes had the same pattern before and after IFN therapy, although no
significant difference was noted between improved and worsened patients. These
results suggest that IFN-alpha may have an antifibrotic effect even in CH-C
patients with no overt response to IFN-alpha therapy, compared with the effect of
medications other than IFN.
PMID- 10680666
TI - Augmenter of liver regeneration (ALR) may promote liver regeneration by reducing
natural killer (NK) cell activity in human liver diseases.
AB - Cytotoxicity of liver natural killer cells against regenerating hepatocytes has
been reported as a possible mechanism of regeneration failure in fulminant
hepatitis. An augmenter of liver regeneration (ALR) inhibits liver natural killer
cell activity in rats. In this study, we measured hepatic expression of ALR mRNA,
blood levels of ALR, and peripheral blood natural killer cell activity in
patients with various types of acute liver disease to investigate the
relationship between failure of liver regeneration and hepatic natural killer
cells. Hepatic ALR mRNA expression was higher in liver disease patients than in
non-liver disease controls, and a correlation was found between serum ALR values
and hepatic levels of ALR mRNA. In acute liver injury, the serum ALR level also
showed a negative correlation with NK activity. ALR was produced by and released
from the liver at the time of hepatic injury. Our findings suggest that ALR may
protect against failure of regeneration by inhibition of hepatic natural killer
cell activity in acute liver injury.
PMID- 10680667
TI - Optimal route of administration of mixed endothelin receptor antagonist (TAK-044)
in liver transplantation.
AB - It is well known that endothelin-1(ET-1) is a factor involved in the pathogenesis
of ischemia-reperfusion injury. This study was undertaken to investigate the
optimal route (intravenous vs intraportal) for administering mixed endothelin
receptor antagonist (TAK-044) in a liver transplantation. First, in a rat
isolated liver cold-perfusion model, the pharmacodynamics of TAK-044 and
endothelin-1 (ET) in the liver tissue and the systemic circulation after cold
perfusion were compared in the different administration routes. Next, in a rat
orthotopic transplantation model, we compared the hepatoprotective effect of TAK
044 among different administration routes. In each model, there were three
groups: IV group, intravenous injection of TAK-044 (10mg/kg) immediately before
cold perfusion or anhepatic phase; IP group, intraportal administration with cold
perfusion solution or with reflush solution for the graft; control group, no
treatment. In the cold perfusion model, liver tissue ET level increased to a
similar extent after reperfusion in the three groups, and the plasma and liver
tissue TAK-044 concentrations after reperfusion were highest in the IV group.
However, the increase in plasma ET was also greatest, and therefore, the ratio of
liver tissue to plasma TAK-044 was lower in the IV group compared with the IP
group. In the transplantation model, elevation of plasma ET was significantly
higher in the IV group. Leakage of serum alanine aminotransferase (ALT),
sinusoidal narrowing, and cell swelling after grafting were significantly
suppressed in the IP group. We conclude that intraportal administration before
reperfusion offers more efficient accumulation of TAK-044 in the liver tissue,
without harmful systemic elevation of ET, and achieves a hepatoprotective effect
on the graft compared with intravenous administration.
PMID- 10680668
TI - Early diagnosis of interferon-induced myocardial disorder in patients with
chronic hepatitis C: evaluation by myocardial imaging with 123I-BMIPP.
AB - Interferon (IFN) therapy for chronic hepatitis C is sometimes associated with
cardiac complications. In the present study, we performed myocardial imaging with
123I-labeled beta-methyl-p-iodophenylpentadecanoic acid (123I-BMIPP) in order to
evaluate myocardial disorders caused by IFN. We studied 40 healthy subjects (H
group) and 25 patients with chronic hepatitis C who had been treated with IFN
(IFN group). A Holter electrocardiogram (ECG) was performed and the autonomic
nervous function was assessed by analyzing the spectral variability and 1/f
fluctuation of heart rate. Myocardial planner imaging with 123I-BMIPP was
performed to obtain the time activity curve for 20min immediately after
administration of 123I-BMIPP (dynamic study). Early and delayed myocardial single
photon emission computed tomography (SPECT) images were expressed as Bull's eyes
and the myocardium was divided into four segments to calculate the washout rate
for each segment on early and late SPECT images (early and late SPECT study). No
significant differences in autonomic nervous function were observed between the
two groups in heart rate variability. In a dynamic study, the reduction rate from
the time activity curve was significantly higher in the IFN group compared with
the H group (reduction rate, IFN group, 5.3 +/- 3.7% vs H group, 1.2 +/- 3.3%; P
< 0.05). In the early and delayed myocardial SPECT study, the washout rate for
the IFN group was significantly increased in all myocardial areas compared to
that in the H group. However, the metabolic disorder of fatty acids caused by IFN
was reversed on the second 123I-BMIPP myocardial scintigraphy examination several
months after IFN therapy. These results indicate that metabolic disorders of
fatty acids caused by IFN therapy can be detected before abnormalities are
observed by Holter-ECG or echocardiography.
PMID- 10680669
TI - Nationwide epidemiological survey of chronic pancreatitis in Japan.
AB - The aim of this study was to estimate the number of patients treated for chronic
pancreatitis in 1994 in Japan and to explore the clinico-epidemiological features
of chronic pancreatitis. Two surveys were conducted. Stratified random sampling
was used to select departments in which patients with chronic pancreatitis were
treated, and two different questionnaires were administered to obtain relevant
information. From the first survey, the total number of patients treated for
chronic pancreatitis in Japan in the year 1994 was estimated as 32,000 (95%
confidence interval, 25,000-39,000). Clinico-epidemiological features, based on
the 2,523 patients reported from the second survey, were subsequently clarified.
The sex ratio (male/female) of the patients was 3.5. Alcoholic pancreatitis was
the most common type in males (68.5%), and idiopathic pancreatitis in females
(69.6%). Compared with the findings in the last survey in 1985, the proportion of
patients with alcoholic pancreatitis has decreased slightly, from 58.7% to 55.5%,
while that of idiopathic chronic pancreatitis has increased in both males and
females. Patients diagnosed by advanced techniques such as computed tomography
(CT) and endoscopic retrograde cholangiopancreatography (ERCP) accounted for
68.1% of the total. The number of patients with chronic pancreatitis treated in
1994 in Japan, was estimated as 32,000, with an overall prevalence rate of 45.4
per 100,000 population in males and 12.4 per 100,000 population in females.
PMID- 10680670
TI - Nuclear cyclin D1 overexpression is a critical event associated with cell
proliferation and invasive growth in gallbladder carcinogenesis.
AB - Cyclin D1 overexpression is remarkably frequent in several human carcinomas and
is believed to be a critical event in oncogenesis. We examined cyclin D1
expression, p53 expression, and the Ki-67 labeling index by immunostaining in
human gallbladder mucosa in conditions varying from normal to malignant tissue.
We also examined K-ras codon 12 mutations in these tissues with a two-step
polymerase chain reaction. Nuclear cyclin D1 overexpression was observed in 48%
of carcinomas occurring independently of adenoma, but not in adenomas, carcinomas
arising in adenomas, or nonneoplastic lesions. Cytoplasmic cyclin D1
overexpression was observed in about 15% of abnormal specimens, irrespective of
the type of epithelial abnormality. Carcinomas showing nuclear cyclin D1
overexpression had significantly higher Ki-67 labeling indexes than those with no
overexpression. Moderately to poorly differentiated adenocarcinomas showed a
higher incidence of nuclear cyclin D1 overexpression than papillary to well
differentiated carcinomas. Specimens with cyclin D1 overexpression showed a high
incidence of lymph permeation, venous permeation, and lymph node metastasis. We
conclude that nuclear cyclin D1 overexpression is a critical event importantly
associated with cell proliferation and invasive growth in gallbladder
carcinogenesis, and that cyclin D1 immunostaining may become a useful marker for
evaluating gallbladder carcinomas.
PMID- 10680671
TI - Four resections for hepatic metastasis from gastric cancer: histochemical
analysis of cell proliferation, apoptosis, and angiogenesis.
AB - In a patient with gastric cancer (GC) associated with one synchronous and three
metachronous hepatic metastases (HM), who underwent four hepatectomies, we
carried out histochemical investigations regarding cell proliferation, apoptosis,
and angiogenesis in the GC and HM. Tissue samples were taken from the primary GC
and four HM. Ki-67 immunostaining was performed to evaluate cell proliferation
and determine the labeling index (Ki-67 LI; ie, the percentage of cancer cells
with nuclei stained for Ki-67). Terminal deoxynucleotidyl transferase-mediated
deoxyuridine triphosphate-biotin nick end labeling (TUNEL) was performed to
evaluate apoptosis and determine the apoptotic index (ie, the percentage of TUNEL
positive cells), and immunostaining for factor VIII-related antigen was performed
to evaluate angiogenesis and measure microvessel density (MVD). The Ki-67 LI was
43.2% in the primary GC and 39.9% in the synchronous HM, and the LI increased
with the number of resections of metachronous HM. The apoptotic index was 3.36%
in the primary GC, and 5.30% in the synchronous HM, and the index decreased after
further resections of the metachronous HM. The MVD was 35 in the primary GC, and
22 in the synchronous HM, and it increased with the number of resections of
metachronous HM. The primary GC in this patient may have strongly influenced the
growth of HM through effects on cell proliferation, apoptosis, and angiogenesis.
PMID- 10680672
TI - Brunner's gland adenoma with a focus of p53-positive atypical glands.
AB - A submucosal tumor was resected endoscopically from the duodenal bulb in a 43
year-old man complaining of epigastric discomfort. The tumor, measuring 22 x 20 x
19mm, consisted mainly of Brunner's glands with no atypia. However, close
histologic examination disclosed a focus of glands with cellular and structural
atypia. The atypical glands showed staining by periodic acid-Schiff, alcian blue,
and high iron-diamine methods. Mucin histochemistry was examined, and the
atypical glands resembled the excretory ducts rather than the acinar cells of the
tumor. Immunohistochemically, positivity for MIB-1 was high (38.0%), and p53
positive cells were detected sporadically in the atypical glands. These results
indicated that the atypical glands probably represented a neoplastic lesion.
Brunner's gland adenomas associated with foci of true neoplasm are very rare;
only two cases, including one patient with microcarcinoid tumors, have been
reported.
PMID- 10680673
TI - Multiple duodeno-jejunal diverticula causing massive intestinal bleeding.
AB - A case of massive intestinal blood loss from multiple duodeno-jejunal diverticula
is described. A 39-year-old man was referred to our hospital because of recurrent
bloody stool and worsening anemia. Upper and lower endoscopy, selective abdominal
angiography, and radionuclide scanning were performed to seek the cause of the
intestinal bleeding, but none of these studies revealed the source of bleeding.
Small-bowel barium follow-through examination showed numerous diverticula in the
distal duodenum and proximal jejunum. Excision of the duodenal diverticulum and
resection of the involved portion of the jejunum cured the patient. On
histopathological examination, an ulcerative lesion with an exposed vessel
suggestive of the source of bleeding was seen in the resected duodenal
diverticulum. Although duodeno-jejunal diverticula are rare, the importance of a
careful search for this malformation in a patient with intestinal blood loss is
stressed.
PMID- 10680674
TI - Acquired ileal diverticulum: an unusual bleeding source.
AB - Acquired ileal diverticulum is an uncommon condition and diagnosis is often
difficult when bleeding occurs from this source. Here we describe two cases of
ileal diverticulum with massive bleeding. Both patients presented with anal
bleeding, but upper and lower gastrointestinal endoscopy did not reveal the
source. Selective visceral angiography finally detected bleeding lesions in the
terminal ileum. Surgical resection was performed in both patients, confirming
that the bleeding arose from diverticula less than 1 cm in size. In patients with
obscure gastrointestinal bleeding, an ileal diverticulum should be considered,
and selective visceral angiography should be performed for precise diagnosis.
PMID- 10680675
TI - Ischemic hepatitis induced by mesenteric volvulus in a patient with chronic
obstructive lung disease.
AB - A 66-year-old man with chronic obstructive lung disease was admitted to our
hospital, presenting with mesenteric volvulus and mild liver injury. A superior
mesenteric angiogram revealed that the arteries supplying the small intestine
were twisted in the arterial phase, while the portal vein was not visualized in
the late phase. A celiac angiogram demonstrated that portal blood flow from the
splenic venous return was maintained. The patient's symptoms had almost resolved
the day after admission, and his serum transaminases level had gradually
decreased to normal with conservative therapy. A superior mesenteric angiogram on
the 13th hospital day showed a normal arteriogram and the portal vein
demonstrated blood flow from the superior mesenteric vein. Liver biopsy revealed
hemorrhagic necrosis around the central veins, which was compatible with ischemic
hepatitis. Since the patient's O2 saturation level on admission was not low
enough to have caused ischemic hepatitis by itself, we suspect that a sudden
decrease in portal blood flow was the additional factor that allowed the
threshold for the initiation of ischemic liver damage to be reached.
PMID- 10680676
TI - Is fish oil (n-3 fatty acids) effective for the maintenance of remission in
Crohn's disease?
PMID- 10680677
TI - Chronic pancreatitis in Japan: is alcoholic pancreatitis decreasing?
PMID- 10680678
TI - In vivo MR micro imaging with conventional radiofrequency coils cooled to 77
degrees K.
AB - Cryogenically cooled conventional surface coils are shown to provide significant
signal-to-noise ratio (SNR) gains for MR micro imaging of tissue structure in
vivo. Measurements are described which employ a simple, all-polyvinyl chloride
(PVC) vacuum dewar capable of maintaining a bath of liquid nitrogen around the
coil, within 5 mm of the tissue to be imaged. Images acquired in vivo at 64 MHz
with a 2-cm diameter copper coil cooled to 77 K demonstrated a gain in SNR of
approximately 2.7 +/- 0.3 relative to those obtained with the same coil at room
temperature under otherwise identical conditions. This increase is consistent
with the reduction in coil resistance and the minor contribution to overall
resistance from the imaging object. The performance of the coil is illustrated
with images from the human finger and rabbit eye and potential applications are
discussed.
PMID- 10680679
TI - Undersampled projection-reconstruction imaging for time-resolved contrast
enhanced imaging.
AB - In time-resolved contrast-enhanced 3D MR angiography, spatial resolution is
traded for high temporal resolution. A hybrid method is presented that attempts
to reduce this tradeoff in two of the spatial dimensions. It combines an
undersampled projection acquisition in two dimensions with variable rate k-space
sampling in the third. Spatial resolution in the projection plane is determined
by readout resolution and is limited primarily by signal-to-noise ratio.
Oversampling the center of k-space combined with temporal k-space interpolation
provides time frames with minimal venous contamination. Results demonstrating
improved resolution in phantoms and volunteers are presented using angular
undersampling factors up to eight with acceptable projection reconstruction
artifacts.
PMID- 10680680
TI - Cardiac real-time imaging using SENSE. SENSitivity Encoding scheme.
AB - Sensitivity encoding is used to improve the performance of real-time MRI. The
encoding efficiency of single-shot and segmented echo-planar imaging is tripled
by means of a 6-element receiver coil array. The feasibility of this approach is
verified for double oblique cardiac real-time imaging of human subjects at rest
as well as under physiological stress. Sample images are presented with scan
times per image down to 13 msec at a spatial resolution of 4.1 mm, and 27 msec at
a resolution of 2.6 mm. Moreover, multiple slice real-time imaging is
demonstrated at a rate of 38 double-frames per second.
PMID- 10680681
TI - A silent event-related functional MRI technique for brain activation studies
without interference of scanner acoustic noise.
AB - A new data acquisition method for silent, event-related functional MRI in which
scanner acoustic noise does not interfere with brain activation is introduced and
evaluated in an auditory tonotopic mapping experiment. This method takes into
account the hemodynamic-response characteristics of the brain during activation,
associated with both task performance and scanner noise. A data acquisition
scheme was designed to collect task-induced brain activation signals without
interference of scanner noise on stimulus delivery or on the measured response.
The advantages of the technique were demonstrated in a tonotopic mapping
experiment of human auditory cortex. Tonotopic maps obtained by the technique in
normal subjects showed distinct spatial shifts of the activation foci in the
lateral part of Heschl's gyrus with changing stimulus frequency, whereas no
systematic shift was shown in a conventional event-related experiment using the
same stimulation paradigm. Signal change in the activation foci with the new
technique was 54% larger than with the conventional technique, suggesting an
increased dynamic range of the signal change associated with task-induced brain
activation under silent conditions.
PMID- 10680682
TI - Assignment of the water slow-diffusing component in the central nervous system
using q-space diffusion MRS: implications for fiber tract imaging.
AB - Diffusion-weighted NMR spectroscopy (MRS) was performed on isolated bovine optic
nerve and rat brain (in vitro) to characterize the multiexponential water signal
decay in diffusion experiments. q-Space analysis of the diffusion data was used
to obtain structural information about the investigated neuronal tissues. This
analysis provided displacement distribution profiles of the water in the sample.
Two diffusing components were identified from these profiles, thus enabling us to
obtain the following information about the slow decaying component: 1)
displacement of this component is restricted to a diffusing distance of
approximately 2 microm; 2) it has a longer T2 than the rapidly diffusing
component; and 3) the population fraction of this component depends on the
orientation of the nerve fiber. When the diffusion was measured perpendicular to
the long axis of the bovine optic nerve, the weighting of this population was 41
+/- 2%, whereas parallel to the long axis of the nerve it was found to be 14 +/-
2%. In the randomly oriented brain tissue, the population of this component was
only 7 +/- 3%. These observations led to the conclusion that the slow-decaying
component originates mainly from restricted water diffusion in the neuronal
fibers. In view of these findings, in vitro and in situ diffusion-weighted images
with high b values (with long delta) were acquired to obtain highly detailed
images of white matter fiber tracts in the central nervous system. These images
provide detailed information on white matter fiber tract location and allow
spinal cord maturation to be followed with high accuracy.
PMID- 10680683
TI - 3D localized 1H-13C heteronuclear single-quantum coherence correlation
spectroscopy in vivo.
AB - A method for spatially three-dimensional (3D) localized two-dimensional (2D) 1H
13C correlation spectroscopy, localized HSQC, is proposed. This method has the
following special feature in the preparation period. The 180 degrees (13C) and
180 degrees (1H) pulses are separated in time, and the 180 degrees (13C) pulse is
applied at 1/4 1JCH) before the 90 degrees (1H) polarization transfer pulse. The
preparation (echo) period 2tau can then be set substantially longer than 1/(2
1JCH), so that even in a whole-body system, slice-selective 90 degrees (1H)
pulses and gradient pulses can be applied in that period. The localization
capabilities of this method were confirmed in a phantom experiment. The 3D
localized 2D 1H-13C correlation spectra from a monkey brain in vivo were obtained
after [1-13C]glucose injection, and amino acid metabolism was detected; that is,
[4-13C]glutamate appeared immediately after the injection, followed by the
appearance of [2-13C]glutamate, [3-13C]glutamate, and [4-13C]glutamine.
PMID- 10680684
TI - 2D-spatial/2D-spectral spectroscopic imaging of intracerebral gliomas in rat
brain.
AB - 1H-MR spectroscopy in vivo is often hampered by poor spectral resolution.
Spectral overlap can be avoided with two-dimensional spectroscopic techniques.
Correlation peak imaging has been implemented to measure unambiguously the
distribution of several metabolites in a rat brain glioma model. Acquisition
weighted spectroscopic imaging reduced the experimental time and provided
excellent spatial localization. The choice of an appropriate spectral acquisition
window granted good sensitivity. Spectroscopic images presenting a full two
dimensional spectrum in every image pixel were acquired in seven rats at 7 Tesla
in 195 min, with a nominal voxel volume of 75 microl. Among other metabolites,
the distribution of hypotaurine, phosphoethanolamine, alanine, and even glucose
could be visualized both in the C6-glioma and in the unaffected brain.
PMID- 10680685
TI - Temperature mapping using the water proton chemical shift: self-referenced method
with echo-planar spectroscopic imaging.
AB - An echo-planar spectroscopic imaging method of temperature mapping is proposed.
This method is sufficiently faster than the so-called 3D magnetic resonance
spectroscopic imaging (3D-MRSI) method and does not require image subtractions,
unlike the conventional phase mapping method when an internal reference signal is
detectable. The water proton chemical shift measured by using the tissue lipid as
an internal reference clearly visualized the temperature change in a porcine
liver sample in vitro. It was also demonstrated that the internally referenced
echo-planar spectroscopic imaging method could markedly reduce a temperature
error caused by a simple, translational motion between scans compared with the
phase-mapping method.
PMID- 10680686
TI - Strong field behavior of the NMR signal from magnetically heterogeneous tissues.
AB - A theory for the behavior of the nuclear magnetic resonance (NMR) signal obtained
from magnetically heterogeneous tissues is developed for the limit of a strong
external magnetic field. If BO is the magnitude of the external magnetic field,
it is found that a free-induction signal decays in a time scaling as 1/Bo, a
single-spin echo signal decays in a time scaling as 1/Bo(2/3), and a multiple
spin echo signal decays in a time scaling as 1/Bo(2). Moreover, it is shown that
the form of the signal decay for a multiple-spin echo sequence may deviate
significantly from an exponential. Numerical results for a model consisting of
randomly distributed magnetic spheres are used to confirm the theory. In
addition, good agreement is demonstrated between the theory and experimental
measurements obtained with particle suspensions. The validity and application of
the theory to biological tissues are discussed.
PMID- 10680687
TI - Relaxation induced by ferritin and ferritin-like magnetic particles: the role of
proton exchange.
AB - Proton T1 and T2 in solutions of ferritin and fercayl (a ferritin-like iron
dextran particle) solutions were measured, over a wide range of various
parameters (Bo, temperature, interecho-time and pH). The window of the previously
referred linear dependence of 1/T2 on the static field was increased, up to 500
MHz, and the independence of T2 on the echo time was confirmed. Correlation times
were extracted from T1 nuclear magnetic relaxation dispersion profiles. In the pH
range studied, no strong variation of the relaxivities of ferritin solutions was
noticed. Fercayl, which, unlike ferritin, remains stable under large pH
variations, is characterized by strongly pH-dependent relaxation rates. This
feature is interpreted as due to the effect of proton exchange in the water
relaxation process. Outer sphere theory, which ignores proton binding, is shown
to be unable to describe the relaxation of ferritin and ferritin-like particles
solutions, first because it predicts a quadratic rate dependence on Bo, but also
because it severely underestimates the relaxation rate. Explaining relaxation
induced by ferritin and ferritin-like particle solutions will likely require a
model that accounts for proton binding.
PMID- 10680688
TI - Method to correlate 1H MRSI and 18FDG-PET.
AB - The in vivo neuronal contribution to human cerebral metabolic rate of glucose
(CMRglc), measured by 18FDG-PET, is unknown. Examining the effect of 1H MRSI
derived N-acetyl aspartate (NAA) concentration on positron emission tomography
(PET) measures of metabolic activity might indicate the relationship of CMRglc to
neuron density. In a population of 19 demented, cognitively impaired, and control
subjects, the Miller-Gartner algorithm was applied to whole-brain PET data to
isolate the PET signal originating in cortical gray matter alone (GMPET). An
analogous procedure applied to multislice proton MRSI data yielded the N-acetyl
aspartate concentration in cortical gray matter (GMNAA). In 18 of 19 subjects, a
significant linear regression (P < 0.05) resulted when GMPET was plotted against
GMNAA, whereby GMPET was higher for higher GMNAA. This suggests that CMRglc rises
linearly with increasing neuron density in gray matter. This method may be used
to investigate the relationship of CMRglc to neurons in various conditions.
PMID- 10680689
TI - Real-time color flow MRI.
AB - A real-time interactive color flow MRI system capable of rapidly visualizing
cardiac and vascular flow is described. Interleaved spiral phase contrast
datasets are acquired continuously, while real-time gridding and phase
differencing is used to compute density and velocity maps. These maps are then
displayed using a color overlay similar to what is used by ultrasound. For
cardiac applications, 6 independent images/sec are acquired with in-plane
resolution of 2.4 mm over a 20 cm field of view (FOV). Sliding window
reconstruction achieves display rates up to 18 images/sec. Appropriate tradeoffs
are made for other applications. Flow phantom studies indicate this technique
accurately measures velocities up to 2 m/sec, and accurately captures real-time
velocity waveforms (comparable to continuous wave ultrasound). In vivo studies
indicate this technique is useful for imaging cardiac and vascular flow,
particularly valvular regurgitation. Arbitrary scan planes can be quickly
localized, and flow measured in any direction.
PMID- 10680690
TI - Functional magnetic resonance imaging in real time (FIRE): sliding-window
correlation analysis and reference-vector optimization.
AB - New algorithms for correlation analysis are presented that allow the mapping of
brain activity from functional MRI (fMRI) data in real time during the ongoing
scan. They combine the computation of the correlation coefficients between
measured fMRI time-series data and a reference vector with "detrending", a
technique for the suppression of non-stimulus-related signal components, and the
"sliding-window technique". Using this technique, which limits the correlation
computation to the last N measurement time points, the sensitivity to changes in
brain activity is maintained throughout the whole experiment. For increased
sensitivity in activation detection a fast and robust optimization of the
reference vector is proposed, which takes into account a realistic model of the
hemodynamic response function to adapt the parameterized reference vector to the
measured data. Based on the described correlation method, real-time fMRI
experiments using visual stimulation paradigms have been performed successfully
on a clinical MR scanner, which was linked to an external workstation for image
analysis.
PMID- 10680691
TI - A broadband phased-array system for direct phosphorus and sodium metabolic MRI on
a clinical scanner.
AB - Despite their proven gains in signal-to-noise ratio and field-of-view for routine
clinical MRI, phased-array detection systems are currently unavailable for nuclei
other than protons (1H). A broadband phased-array system was designed and built
to convert the 1H transmitter signal to the non-1H frequency for excitation and
to convert non-1H phased-array MRI signals to the 1H frequency for presentation
to the narrowband 1H receivers of a clinical whole-body 1.5 T MRI system. With
this system, the scanner operates at the 1H frequency, whereas phased-array MRI
occurs at the frequency of the other nucleus. Pulse sequences were developed for
direct phased-array sodium (23Na) and phosphorus (31P) MRI of high-energy
phosphates using chemical selective imaging, thereby avoiding the complex
processing and reconstruction required for phased-array magnetic resonance
spectroscopy data. Flexible 4-channel 31P and 23Na phased-arrays were built and
the entire system tested in phantom and human studies. The array produced a
signal-to-noise ratio improvement of 20% relative to the best-positioned single
coil, but gains of 300-400% were realized in many voxels located outside the
effective field-of-view of the single coil. Cardiac phosphorus and sodium MRI
were obtained in 6-13 min with 16 and 0.5 mL resolution, respectively. Lower
resolution human cardiac 23Na MRI were obtained in as little as 4 sec. The system
provides a practical approach to realizing the advantages of phased-arrays for
nuclei other than 1H, and imaging metabolites directly.
PMID- 10680692
TI - Interventional MRI-guided brain biopsies using inductively coupled surface coils.
AB - The technical realization of inductively coupled surface coils for interventional
MR-guided procedures, and the application to brain biopsies in a 0.2 T magnet is
described. The advantages compared to standard coils are discussed, and the
results of 26 biopsies on eight different neuropathologic diagnoses from varying
locations within the brain are presented. Initial experience shows that
inductively coupled coils can offer an increased number of indications for
interventional procedures in the brain, easier handling of sterility, and often a
better access for the surgeon, compared to the use of standard MR head coils.
PMID- 10680693
TI - A transmit-only/receive-only (TORO) RF system for high-field MRI/MRS
applications.
AB - The design and operation of a detunable shielded hybrid birdcage RF head coil
optimized for human brain imaging at 170 MHz is presented. A high duty-cycle and
rapid-switching decoupling scheme that allows uniform RF transmission with the
head coil and reception with a surface coil within the volume of the head coil is
also demonstrated. In addition, the circumscribing hybrid coil can be biased to
operate as a conventional transmit/receive head coil. Our RF design allows the
use of higher sensitivity surface coils or phased-array coils at very high
magnetic fields where body RF resonators are not currently available or whose use
is precluded by specific-absorption ratio restrictions. The design also allows
the use of receive-only coils within head gradient inserts, which normally do not
allow transmission with an RF body resonator at any field strength.
PMID- 10680694
TI - Demonstration of a compact compressor for application of metastability-exchange
optical pumping of 3He to human lung imaging.
AB - Hyperpolarized gas magnetic resonance imaging has recently emerged as a method to
image lungs, sinuses, and the brain. The best lung images to date have been
produced using hyperpolarized 3He, which is produced by either spin-exchange or
metastability-exchange optical pumping. For hyperpolarized gas MRI, the
metastable method has demonstrated higher polarization levels and higher
polarizing rates, but it requires compression of the hyperpolarized gas. Prior to
this work, compression of hyperpolarized gas had only been accomplished using a
large, complex and expensive apparatus. Here, human lung ventilation images are
presented that were obtained using a compact compressor that is relatively simple
and inexpensive. For this test, 1.1 bar-L of 15% hyperpolarized 3He gas was
produced at the National Institute of Standards and Technology using a modified
commercial diaphragm pump. The hyperpolarized gas was transported to the
University of Pennsylvania in a holding field provided by a portable solenoid.
PMID- 10680695
TI - In vivo intravoxel incoherent motion measurements in the human placenta using
echo-planar imaging at 0.5 T.
AB - This paper presents the first in vivo measurements of intravoxel incoherent
motion in the human placenta, obtained using the pulsed gradient spin echo (PGSE)
sequence. The aims of this study were two-fold. The first was to provide an
initial estimate of the values of the IVIM parameters in this organ, which are
currently unknown. The second aim was then to use these results to optimize the
sequence timings for future studies. The moving blood fraction (f), diffusion
coefficient (D), and pseudo-diffusion coefficient (D*) were measured. The average
value of f was 26 +/- 6 % (mean +/- SD), D was 1.7 +/- 0.5 x 10(-3) mm2/sec, and
D* was 57 +/- 41 x 10(-3) mm2/sec. For the optimized values of b, the expected
percentage uncertainty in the fitted values of f, D, and D* for the placenta were
sigmaf/f = 14.9%, sigmaD/D = 14.3%, sigmaD*/D* = 44.9%, for an image signal-to
noise of 20:1, and a total imaging time of 800 sec.
PMID- 10680696
TI - Fast functional MRA using time-resolved projection MR angiography with
correlation analysis.
AB - Most recently, time-resolved 2D MRA after injection of a contrast agent bolus for
various applications has been proposed. Similar to conventional digital
subtraction angiography (DSA), 2D MR DSA offers the ability to observe the
dilution of the bolus in the vascular system during the passage with a temporal
resolution considerably below 1 sec. The purpose of this paper is to present
strategies to improve the inherent low signal-to-noise ratio of 2D angiograms
while retaining some temporal resolution. This can be achieved by applying
algorithms for time series analysis as used in functional MRI. The significantly
improved image quality is demonstrated on examples from clinical studies from
bronchial MRA as well as cardiovascular MRA. In addition to the increased signal
to-noise ratio, correlation analysis leads to suppression of background signals
and to a better discrimination of overlapping vessels. Further improvements in
the temporal discrimination of vessels is afforded by the use of consecutive
multiple contrast agent boli as demonstrated by numerical simulations and
experiments.
PMID- 10680697
TI - A median filter for 3D FAST spin echo black blood images of cerebral vessels.
AB - High-resolution black-blood MRA images of intracranial vascular anatomy can be
obtained using 3D fast spin-echo techniques. Although these images demonstrate
excellent contrast between vessels and surrounding soft tissues, the dark signal
from air and bone can obscure the desired vascular information when a minimum
intensity projection image is created. In this paper, we describe an image
processing technique based upon a median filter that is effective for detecting
narrow vessel-like structures. Minimum intensity projection images of the
filtered MRA volume can be obtained in any orientation without prior segmentation
of the skull or surrounding air spaces. The filter is very effective for
detecting and visualizing small vessels, but is much less effective for detecting
vessels and vascular pathology larger than the filter detection width. The
filtering technique is demonstrated on black-blood MRA images from a volunteer
study.
PMID- 10680698
TI - Cardiac-respiratory gating method for magnetic resonance imaging of the heart.
AB - In studies of transmural myocardial function, acquisitions of high spatial and
temporal resolution tagged cardiac images often exceed the practical time limit
for breath-hold fast imaging techniques. Therefore, a dual cardiac-respiratory
gating device has been constructed to acquire SPAMM-tagged cardiac MR images at
or near end-expiration during spontaneous breathing, by providing an external
trigger to a conventional MRI system. Combined cardiac and respiratory gating
essentially eliminates the respiratory motion artifacts in tagged cardiac MR
images. Compared to cardiac-gated images obtained during intermittent breath
holds, cardiac-respiratory gated images show improved tag-myocardium contrast due
to magnetization recovery during inspiration.
PMID- 10680699
TI - Field mapping without reference scan using asymmetric echo-planar techniques.
AB - Improvements in Bo mapping and shimming were achieved by measuring the static
field information in multiple subsequent echoes generated by an asymmetric echo
planar readout gradient train. With careful compensation, eddy current effects
were shown to affect the adjustment of the shim coils minimally. In addition to
reducing the time required for field mapping by two-fold, the sensitivity was
simultaneously optimized irrespective of the prevalent T2* present, thereby
minimizing the error of the static field measurement to below 0.1 Hz. With
adiabatic low flip-angle excitation, the time required for field mapping was
below 1 second.
PMID- 10680700
TI - Expression of complement regulatory proteins CR1, DAF, MCP and CD59 in
haematological malignancies.
AB - Host cells are protected from the lytic effect of the complement system by
complement regulatory proteins. This study was designed to investigate the
expression of complement regulatory proteins on leukemic blasts which may be
susceptible to the lytic effects of the complement system in the circulation. The
surface expressions of complement regulatory proteins, complement receptor 1
(CR1, CD35), decay accelerating factor (DAF, CD55), and homologous restriction
factor 20 (HRF20, CD59), on peripheral blood and bone marrow blasts were
evaluated by using flow cytometry in 16 acute myeloblastic leukemia (AML), 16
acute lymphoblastic leukemia (ALL), 4 chronic lymphocytic leukemia (CLL), 3
chronic myelocytic leukemia (CML) patients and control granulocytes and
lymphocytes obtained from 15 healthy volunteers. mRNA expression was investigated
by Northern blot analysis. mRNA abundances were calculated after normalization
according to 28s rRNA. Surface expressions of CRI and DAF were marginally (p =
0.08 and p = 0.08, respectively) lower in AML, and DAF expression was
significantly lower (p=0.0008) in ALL patients in comparison to their normal
counterparts. Except from a slight increase that is detected for CD59 in CML
patients (p=0.06), there was no significant difference between the surface
expressions of CD59 in any of the groups studied. Densitometric analysis of
autoradiographs obtained from Northern blots revealed that in AML patients, CR1
mRNA expression were 5.5-fold lower than controls (p=0.06), while DAF mRNA
expression was significantly higher (p=0.0046). Furthermore, the mRNA expression
of CRI in ALL patients was found significantly lower than in the control group (p
= 0.0419). None of the values obtained from the other groups were significantly
different from each other. These results suggest that leukemic blasts are
protected from the lytic attack of the complement system at all levels, since all
of the complement membrane regulatory proteins were expressed in all leukemia
types (although at lower amounts in some cases), and it is also possible to use
CRI and DAF as differentiation markers in acute leukemias.
PMID- 10680701
TI - Cell kinetic study of normal human bone marrow hematopoiesis and acute leukemia
using 7AAD/PY.
AB - We have used the 7AAD/PY method to analyze the cell cycle status of normal human
bone marrow hematopoiesis, and found that the cell kinetics differed. There were
cells with relatively low levels of RNA in the S-phase (Type I) and a high level
in the S-phase (Type 11). T-cells, B-cells, nucleated red cells and CD34+/CD19+
early B-cells in bone marrow were Type I, whereas myelomonocytic subset and
CD34+/CD33-dim+ common myeloid cells were Type II. AC133+/CD38-dim cells, which
were thought to be lineage-marker negative hematopoietic stem cells, had
intermediate amounts of RNA in the S-phase between Type I and II (Type 0).
Seventy-four cases of acute leukemia were also analyzed. Most of the T- and B-ALL
cases were found to be Type I, most of the ANLL cases were Type II, and there
were 10 cases that were Type 0. These findings yielded fundamental information
about normal hematopoiesis and acute leukemia.
PMID- 10680702
TI - Increased liposome-mediated gene transfer into haematopoietic cells grown in
adhesion to stromal or fibroblast cell line monolayers.
AB - We investigated transfection rates of CD34+ haematopoietic progenitor cells (HPC)
or haematopoietic cell lines (TF-1, KG1a and K562) using the LacZ gene as a
reporter and cationic liposomes. The transfection efficiency of CD34+
haematopoietic progenitor cells (HPC) or TF-1, KG1a and K562 grown in suspension
is very low (average percentage of 0.013 for HPC and 0.03 for cell lines).
Adhesion of HPC or cell lines to plates by immunological or physical methods
significantly enhances transfection efficiency; however, the percentage of
transfected cells still remained low. We found that adhesion of TF-1, KG1a and
K562 HC to MS-5 stroma cells or NIH-3T3 fibroblast cells increased transfection
efficiency. Under these conditions transfection is achieved in 11.2-25% (mean
18.30%) for the cell lines and 13.6% (range 8.2-24.2%) for CD34+ HPC. These
results indicate that liposome-mediated transfection of HC is significantly
increased when cells are grown in adherence to stroma or fibroblast monolayers.
PMID- 10680703
TI - Polycythaemia vera: bone marrow histopathology under treatment with interferon,
hydroxyurea and busulphan.
AB - Little is known about long-term effects of myelosuppressive therapy on bone
marrow of patients with polycythaemia vera, since histopathology from follow-up
biopsies has not been frequently reported. Thus we conducted a retrospective
morphometrical analysis of diagnostic and follow-up biopsies of 62 patients,
evaluating fibre content, megakaryocytes and bone marrow cellularity. 8/62
patients were treated with interferon-alpha (INF), 11/62 with hydroxyurea (HU)
and 11/62 with busulphan (BU). 32/62 served as controls; they were not treated
with myelosuppressive drugs but with phlebotomy only. The median observation time
was 2.3 yr. Results were compared on the basis of change per time. The bone
marrow of the patients with phlebotomies only was characterised by increasing
cellularity of haematopoesis, number and volume ratio of megakaryocytes and fibre
content. In BU- and HU-treated patients, the haematopoesis was significantly
reduced. The IFN patients revealed a reduction of cellularity which was not
significant. The fibre content was reduced by BU only, but not significantly. No
correlation between megakaryocytes and fibres was found. It could be concluded
therefore that: 1) fibre proliferation within the bone marrow was not
significantly altered by IFN, HU or BU. 2) Cellularity of haematopoesis was
reduced significantly by HU and BU but only partly by IFN, corresponding with
haematological remission.
PMID- 10680704
TI - Neonatal and maternal thrombocytopenia: incidence and immune background.
AB - We performed a prospective study on the incidence of thrombocytopenia (t-penia)
and its immunological origin in unselected 26,275 mothers and 24,101 newborns.
Platelet antibodies were examined by the platelet immunofluorescence test (PIFT)
and the monoclonal antibody immobilisation of platelet antigens assay (MAIPA). T
penia (platelet count < 100 x 10(9)/I) was found in 124 (0.5%) mothers (in 0.04%)
severe, <50x 10(9)/l) and in 116 (0.5%) newborns (in 0.15% severe); 90 (72.6%)
and 112 (96.6%), respectively, were available for further studies. In both groups
non-immune t-penia was diagnosed about 4.5 times more often than the immune t
penia. Among 90 mothers, t-penia was severe in 11.1%, antibodies were detected in
17.8%; both factors were not prognostic for delivering thrombocytopenic newborns.
Among 112 babies, 21 were delivered by thrombocytopenic mothers and 91 by mothers
with normal platelet count; among newborns with immune t-penia the proportion of
alloimmune (NAIT) to autoimmune was equal (10 with NAIT, 10 with autoimmune, 4 of
them born by mothers with hidden autoimmune t-penia). In 33% of the neonates t
penia was severe, most often among NAIT. In conclusion, although t-penia in
mothers as well as in infants is not frequent and severe, and an immune origin
not often found, the search for antibodies, in particular alloantibodies, should
be done. Even if the serological results are not helpful at the moment, they can
be of importance in subsequent pregnancy and for related pregnant women.
PMID- 10680705
TI - Alpha-interferon as induction and maintenance therapy in hairy cell leukemia: a
long-term follow-up analysis.
AB - Although in recent years the use of purine analogues has increased the percentage
of long-term complete response the effect on overall survival of patients with
hairy cell leukemia (HCL) is not yet clear. This study aimed to evaluate the long
term outcome (mean follow up of 92 months) of 64 patients receiving IFN as first
line therapy. IFN was well tolerated and effective. The overall response rate was
91% (PR 65%, CR 13%, GPR 13%). Forty-one patients (63%) received IFN 3 MU/ wk as
maintenance therapy. The 10-yr projected survival rate of responding patients (CR
and GPR 100%; PR 95%) and non-responders (SD, PD 80%) clearly shows that type of
response does not affect survival. Patients receiving IFN maintenance had a
statistically higher PFS than those who did not (p <0.01). This study shows that
IFN is still one of the standard therapies for this disease, that achieving CR
has no primary relevance for the control of the disease, and that good
utilization of therapeutic resources may assure HCL patients a survival rate
comparable to that of a normal, healthy population.
PMID- 10680706
TI - Association of the alpha-spectrin R28H mutation with allele alphaLELY and with
alphaI/alphaII domain haplotypes in three Brazilian families.
AB - We have studied three Brazilian kindreds presenting spectrin alpha/74 hereditary
elliptocytosis (HE) due to a G-->A substitution, responsible for the R28H
mutation. The mutant allele was associated with alphaI domain haplotype 1 (XbaI
/MspI-/PvuII+) in all three families and with two different alphaII domain
haplotypes (1/RIT, 4/RVR). This result may reflect that this mutation occurs in a
"hot spot" and may have arisen more than once or that a crossing over event may
have occurred between the two domains studied. We detected one new haplotype in
the alphaI domain (haplotype 3 -XbaI(+)/MspI(-)/PvuII(+)). The mutant allele was
associated with the lack of the alphaII domain Alu insertion in all three cases.
Allele alphaLELY, detected by PCR and restriction enzyme digestion, was present
in the heterozygous form in patient 1 (alphaHE/alphaLELY) and in the homozygous
form in patients 2 and 3(alphaHE-LEL/alphaLELY). It was found to be associated
with domain haplotypes I (RIT) and 4 (RVR) and with the presence and absence of
the Alu insertion. This may have arisen through recombination events, since this
polymorphism is located in the alphaIV-alphaV domain junction, which is far
distant from the alphaII domain.
PMID- 10680707
TI - Hereditary haemorrhagic telangiectasia with protein S deficiency in a family: a
case report.
PMID- 10680708
TI - Effect of biscoclaurine alkaloids, prednisolone and ascorbic acid on
myelodysplastic syndrome with pancytopenia: a case report.
PMID- 10680709
TI - CD45-negative acute leukemia in adulthood.
PMID- 10680710
TI - Gammadelta T cell lymphoproliferation: a case report.
PMID- 10680711
TI - Relative and combined effects of ethanol and protein deficiency on bone histology
and mineral metabolism.
AB - This study was performed to analyze the relative and combined effects of ethanol
and protein deficiency on bone histology and mineral metabolism in 4 groups of 7
animals each which were pair-fed during 8 weeks with 1) a nutritionally adequate
diet; 2) a 36% (as energy) ethanol containing isocaloric diet; 3) a 2% protein,
isocaloric diet; and 4) a 36% ethanol 2% protein isocaloric diet, respectively,
following the Lieber-DeCarli model. Another group of five rats were fed ad
libitum the control diet. The first and second lumbar vertebrae were removed
after sacrifice, and processed for histomorphometrical analysis of undecalcified
bone samples. Blood and 24-h urine were also collected. Protein malnutrition, but
not ethanol, leads to osteoporosis and reduced osteoid synthesis, whereas ethanol
and protein malnutrition both lead to impaired bone mineral apposition and
increased urinary hydroxyproline excretion. These changes are accompanied by an
increase in serum parathormone and serum 1,25 dihydroxy vitamin D3, a slight
hypomagnesemia, hypercalciuria and hyperphosphaturia; protein deficiency plays an
independent role in these alterations, whereas both ethanol and protein
deficiency exert independent effects on decreasing serum testosterone levels;
this last alteration may contribute to the bone changes mentioned before.
PMID- 10680712
TI - Influence of ethanol on lead distribution and biochemical changes in rats exposed
to lead.
AB - In the present study, an attempt has been made to investigate the effect of
ethanol consumption on the distribution of lead in different regions of brain and
body organs of male albino rats. Lead when administered intragastrically, for a
period of eight weeks resulted in almost uniform accumulation of this metal in
all the regions of brain, which increased by almost two fold when ethanol was
given along with lead. Lead was also seen to compartmentalise in almost all the
tissues of the body to varying extents, with the highest accumulation in the
kidney. A progressive and appreciable accumulation of lead was seen in blood with
a concomitant increase in ZPP levels in animals during the course of treatment,
which increased further when ethanol was administered along with lead. The
activity of delta-ALAD and AChE in blood was significantly decreased in lead as
well as ethanol treated animals. However, in animals coexposed to lead and
ethanol, the inhibition of delta-ALAD was not significantly different, when
compared to only lead-treated animals. The results suggested that animals exposed
to ethanol and lead simultaneously accumulate higher levels of lead in blood and
brain of animals making them more vulnerable to the haematological and
neurological toxic effects of lead.
PMID- 10680713
TI - Effects of phentermine and fenfluramine on alcohol consumption and alcohol
withdrawal seizures in rats.
AB - The drug combination of phentermine plus fenfluramine has been used clinically in
both the treatment of obesity and alcoholism. The aim of the current study was to
assess the interaction of the two drugs on consumption of both an alcohol
containing and a nonalcoholic diet. Furthermore, the efficacy of the drug
combination on suppression of withdrawal seizures was determined. Animals were
either maintained on a 6% alcohol-containing diet, free-fed an isocaloric
control, or pair-fed the control diet. It was observed that, with regard to body
weight growth curves, alcohol provides about 2.5 kcal/g. Both phentermine and
fenfluramine caused a decrease in consumption 1 h after administration; however,
during the next 23 h, 4 mg/kg phentermine significantly increased consumption of
all diets. At doses of 1 and 2 mg/kg, fenfluramine selectively reduced
consumption of the alcohol-containing diet as compared to the isocaloric diets.
Lower doses of fenfluramine blocked the increases in consumption induced by
phentermine. Furthermore, in animals fed the nonalcoholic diet, the drug
combination of 2 mg/kg fenfluramine plus 8 mg/kg phentermine produced a 63-82%
reduction in consumption, an effect not seen when either drug was administered
alone. This greater than additive effect was also seen in the earlier time
periods in animals pair-fed the control diet. Neurochemical analysis from these
animals revealed that the alcohol-dependent animals displayed a significant
reduction of DOPAC and 5-HIAA levels in the striatum, frontal cortex, and
hypothalamus after a 9-h withdrawal period, further implicating the serotonergic
and dopaminergic systems in mediation of withdrawal symptoms and alcohol craving.
Finally, 8 mg/kg phentermine plus 8 mg/kg fenfluramine completely abolished
alcohol withdrawal seizures, compared to a 78% rate in saline treated rats. In
conclusion, the coadministration of phentermine plus fenfluramine produced a
moderate reduction of alcohol consumption and was completely effective at
reducing alcohol withdrawal seizures.
PMID- 10680714
TI - Motor impairment produced by ethanol and site-selective NMDA receptor antagonists
in mice: tolerance and cross-tolerance.
AB - Current perspectives on clinical use of N-methyl-D-aspartate (NMDA) receptor
antagonists infer acute and repeated administration schedules for management of
different pathological states. Development of tolerance and cross-tolerance
between different antagonists may significantly affect their clinical
effectiveness. Since ethanol was repeatedly demonstrated to act as NMDA receptor
antagonist, ethanol use may also have its impact on the effects of NMDA receptor
ligands. Using the rotarod test in mice, the present study evaluated development
of tolerance and cross-tolerance between ethanol (3.2 g/kg, p.o.), competitive
NMDA receptor antagonist, D-CPPene (5.6 mg/kg, i.p.), and low-affinity NMDA
receptor channel blocker, memantine (30 mg/kg, i.p.), that were administered for
seven days once a day after the daily rotarod training session. Acute tests with
ethanol (0.3, 1, 1.7, 3.2 g/kg), D-CPPene (0.3, 1, 3, 5.6 mg/kg) and memantine
(1, 3, 10, 30 mg/kg) revealed that (a) each of these drugs dose-dependently
disrupted rotarod performance in drug-naive mice; (b) in ethanol- and D-CPPene
treated mice, tolerance was observed to ethanol and D-CPPene but not to
memantine; moreover, effects of memantine were even more pronounced in D-CPPene
treated subjects; and (c) repeated memantine administration decreased acute motor
impairing effects of ethanol, D-CPPene and memantine. Thus, the history of
ethanol use or abuse may influence pharmacological activity of NMDA receptor
antagonists and this effect is dependent on type of the NMDA receptor antagonist
applied.
PMID- 10680715
TI - Lipopolysaccharide-stimulated nitric oxide production and inhibition of cell
proliferation is antagonized by ethanol in a clonal macrophage cell line.
AB - Both chronic and acute ethanol exposure have been shown to be cytotoxic and also
to disrupt normal cell function or responses in a variety of cell types.
Macrophage function has specifically been shown to be disrupted by chronic
ethanol exposure by mechanisms that have not been elucidated. It is known that
exposure of macrophages to lipopolysaccharide (LPS) from gram-negative bacteria
will decrease the number of cells. Since increased exposure to endotoxin is often
associated with chronic alcoholism, this may be one mechanism to account for loss
of macrophages in alcoholic patients. The loss of macrophages, as a consequence
of endotoxin treatment, appears to be linked to cell activation and, in
particular, LPS-stimulated synthesis of nitric oxide which has been suggested to
cause an increase in apoptosis. Ethanol also increases apoptosis in some cell
types but, in general, ethanol inhibits activation of macrophages. Thus, the
overall effect on cell numbers and cell proliferation elicited by treating
macrophages concomitantly with ethanol and LPS depends on the balance between
inhibiting LPS-mediated activation and the actions of ethanol. The interaction
between ethanol and LPS was investigated in a macrophage cell line (RAW 264.7
cells) by measuring nitric oxide production and cell proliferation. A 24-h
exposure to ethanol (100 mM) decreased [3H]-thymidine incorporation
significantly. LPS treatment elicited a concentration-dependent decrease in [3H]
thymidine incorporation at LPS concentrations of 0.1 ng/ml to 1000 ng/ml and
stimulated nitric oxide production at concentrations above 1 ng/ml. LPS
stimulated nitric oxide production was inhibited by ethanol (20 to 100 mM) and
the nitric oxide synthesis inhibitor, N(G)Nitro-L-arginine methyl L-NAME) ester
(100 and 500 microM). However, LPS-inhibited [3H]-thymidine incorporation was not
be totally reversed by ethanol- or L-NAME-treatment. A direct correlation between
nitric oxide production and inhibition of cell proliferation could not be
demonstrated. However, it appears that ethanol and LPS do affect some common
mechanism(s) in this cell line.
PMID- 10680716
TI - Ontogeny of ethanol elimination and ethanol-induced hypothermia.
AB - Ontogeny of ethanol elimination rates and ethanol-induced hypothermia were
examined as possible mechanisms contributing to the marked reduction in ethanol
sensitivity early in life (Little et al., 1996; Silveri & Spear, 1998) and the
notable gender difference in ethanol sleep-time seen in adult animals (Silveri &
Spear, 1998). Elimination rates and brain/blood ethanol levels were determined
following doses of 1.5 or 4.5 g/kg ethanol in male and female Sprague-Dawley rats
at postnatal days (P)16, 26, 36, or 56. Animals were sacrificed at 40, 80, or 160
min post-injection, with ethanol elimination rates estimated from the slope of
the regression of blood and brain alcohol levels across the three sampling
periods. P16 animals exhibited the slowest rate of ethanol metabolism, while no
gender effects were evident at any age. Observed ontogenetic increases in ethanol
hypothermia were not systematically related to the ontogeny of ethanol
metabolism. Factors other than ontogenetic changes in ethanol metabolism,
hypothermia, or the distribution of ethanol between brain and blood must underlie
the relative insensitivity to ethanol often reported in young and adolescent
organisms, a fruitful area for future studies given the frequent use and misuse
of alcohol by human adolescents.
PMID- 10680717
TI - Reaction of nitroxyl, an aldehyde dehydrogenase inhibitor, with N-acetyl-L
cysteine.
AB - Nitroxyl (HNO) is the aldehyde dehydrogenase (AIDH) inhibitor produced by
catalase action on cyanamide. Incubation of N-acetyl-L-cysteine (NAC), a reagent
with a free sulfhydryl group, with Piloty's acid (a nitroxyl generator) suggested
that NAC was acting as a competitive "trap" for nitroxyl. Elucidation of the
structure of this reaction product should give an insight as to how nitroxyl
interacts with AIDH, a sulfhydryl enzyme. We now present evidence that the
product formed is N-acetyl-L-cysteinesulfinamide (NACS). We have synthesized NACS
and showed that this synthetic product was identical to the product formed in the
trapping experiment. Both had identical RT values by reverse phase HPLC and
identical RF values by TLC using three different solvent systems. The structural
identification of this nitroxyl trapped product as a sulfinamide now allows the
chemical confirmation of the active-site cysteine residue of AIDH as Cys-302.
PMID- 10680718
TI - Haloperidol administered subchronically reduces the alcohol-deprivation effect in
mice.
AB - During the pre-experimental phase, hybrid (CBA x C57BL) male mice having had 16
weeks free access to food, water and flavored 30% alcohol were deprived of
alcohol for 3 days. The next day they were given free choice between similarly
flavored water and 30% alcohol. The mice were divided into two subgroups having
(HD) or lacking (LD) the deprivation-induced elevation in alcohol intake during
the first 1.5 h of renewed access compared with their intake during the last 22.5
h of first postdeprivation day. In Experiment 1, alcohol naive, LD, and HD mice
received daily injections of haloperidol (Haldol; 1 mg/kg) or vehicle during 14
days of abstinence. The behavior of the mice was evaluated in an exploratory
cross-maze and inescapable slip funnel test a day after the 13th injection
(before the 14th injection). On the first postinjection day, the mice were again
given a free choice between flavored water and alcohol. In Experiment 2, all the
mice were administered with vehicle during the first 13 days of abstinence. On
14th day, they received an injection of haloperidol (1 mg/kg) or vehicle and a
day later were given choice between flavored water and alcohol. Unlike a single
injection, the subchronic administration of haloperidol lowered the alcohol
intake by HD mice with a more prominent decrease seen during the first 1.5 h than
during the last 22.5 h of first postdeprivation day. The alcohol-deprivation
effect in HD mice decreased by 79% after subchronic haloperidol. No significant
change in alcohol intake was found in alcohol-naive and LD mice. Water intake did
not vary systematically. Among the groups, the effect of subchronic haloperidol
on the alcohol-deprivation effect did not parallel changes in most of the
measures of exploratory or avoidance behavior. It is proposed that haloperidol
administered subchronically may attenuate motivation for alcohol.
PMID- 10680719
TI - Anxiety in mice following acute aspartame and ethanol exposure.
AB - The purpose of the present study was to look at the effect of aspartame on the
anxiolytic actions of ethanol. Previous research has shown that ethanol reliably
produces an anxiolytic effect on rodent's plus-maze performance. There have been
anecdotal reports that aspartame increases anxiety. CD-1 male mice were given
i.p. aspartame doses of vehicle, 1000, or 2000 mg/kg, followed 30 min later by
i.p. ethanol doses of 1.6 g/kg or vehicle. Animals were then placed in an open
field, then tested in the plus-maze. Results determined that the aspartame
condition had no significant effect on anxiety-related behavior, nor did it alter
the anxiolytic actions of ethanol. Thus, acute high dose exposure to aspartame
does not appear to affect anxiety-related behaviors.
PMID- 10680720
TI - Differential sensitivity of mouse neural crest cells to ethanol-induced toxicity.
AB - Neural crest cells (NCCs) have been identified as an important target population
relative to ethanol-induced teratogenicity in both mouse and avian models.
Additionally, whole embryo culture mouse models have shown strain-related
differences in sensitivity to ethanol-induced damage following acute exposure
during early NCC development. That differential sensitivity of NCCs may
contribute to these strain differences has been unexplored. For this purpose,
cultured NCCs from an inbred mouse strain (C57BL/6J; C57) that is more sensitive
to ethanol-induced teratogenicity than an outbred strain (ICR) were compared.
This study showed that the incidence of cell death was significantly higher for
the C57 NCCs than those from the ICR strain at all ethanol concentrations tested,
and as early as 12 hours after initial exposure to 100 mM ethanol. The lateral
mobility of the membrane lipids was faster and the membrane GM1 content was lower
in C57 cells than ICR cells both under control conditions and at all doses and
times tested. Ethanol exposure resulted in significant increases in the membrane
lipid lateral mobility, and decreases in the membrane GM1 content that occurred
in a dose and time-dependent manner in the NCCs from both strains. A significant
correlation was found between the GM1 content and lateral mobility of the
membrane lipids, the lateral mobility of membrane lipids and cell viability, as
well as the GM1 content and cell viability in the NCCs from both strains. These
results suggest that different strain sensitivities to ethanol-induced
teratogencity may lie, at least in part, in the interstrain differential response
of the NCC population and that the vulnerability of the NCCs to ethanol-induced
death may be related to their endogenous membrane GM1 content.
PMID- 10680721
TI - The role of dietary fat in alcohol's prenatal effects.
AB - Pregnant rats were fed a control diet or high saturated fat diet (lard) for 6
weeks prior to breeding and continued to consume these diets during pregnancy.
Beginning on gestation day 8, rats in each diet group were intubated with 5.5 or
0 g/kg alcohol. Rats in the 0 g/kg group were pair-fed to those in their
respective 5.5 g/kg groups. Offspring were weighed at birth. On postnatal days 18
and 20, they were tested for passive avoidance learning and locomotor activity,
respectively. Animals prenatally exposed to alcohol weighed less at birth and at
weaning time (21 days of age) and required more trials to reach criterion in the
passive avoidance test but did not differ in activity. Diet did not affect any of
these measures significantly nor were there any significant interactions. We
conclude that high saturated fat from lard does not influence alcohol's prenatal
effects.
PMID- 10680722
TI - Thyrotropin releasing hormone decreases alcohol intake and preference in rats.
AB - Thyrotropin releasing hormone (TRH) has been reported to reduce stress- and
deprivation-induced eating, hypothetically by induction of satiation. Early work
demonstrated thyroid extracts reduced alcohol intake, and recent research shows a
TRH analog specifically inhibits alcohol preference. We determined whether
parenteral administration of TRH reduces alcohol consumption and choice in a
manner consistent with a satiation effect. Water-restricted ad lib fed female and
male rats (n = 12) were given access to 5% w/v ethanol 0 or 30 minutes after
intraperitoneal (i.p.) injection of TRH. TRH (20-40 mg/kg) inhibited alcohol
intake only if injected immediately before alcohol access. Inhibition of alcohol
intake was reliably accompanied by increased production of fecal boli but not by
reliably decreased food intake. Rats given a choice of 2% w/v ethanol and water
decreased alcohol preference after TRH (20 mg/kg) but did not reduce total fluid
intake. Results are partially consistent with the hypothesis of TRH as one of
several functional elements in the integrative neuropeptide control of alcohol
consumption via short-term satiation.
PMID- 10680723
TI - Neonatal alcohol exposure produces more severe motor coordination deficits in
high alcohol sensitive rats compared to low alcohol sensitive rats.
AB - Prenatal exposure to alcohol can produce a number of behavioral alterations,
including hyperactivity, learning deficits and motor impairments. However, the
severity and nature of behavioral alterations varies markedly among children of
women who drink during pregnancy. One important determinant of this variation may
be genetic differences in the response to alcohol. Recently, we demonstrated that
exposure to alcohol during development produced hyperactivity in rats bred for
high alcohol sensitivity (HAS), but not in rats bred for low alcohol sensitivity
(LAS). These lines were selectively bred for extremes in alcohol-induced "sleep
time." The present study investigated the effects of ethanol exposure during
development on motor coordination later in life in both HAS and LAS rats. Using
an artificial rearing procedure, neonatal pups from each line were exposed to a
binge-like alcohol treatment on postnatal days (PD) 4-9. Within each line, one
group was exposed to ethanol (6.0 g/kg/day), one group served as an artificially
reared control, and a third served as a normally reared control group. On PD 30,
parallel bar motor performance was evaluated. Exposure to ethanol during
development severely impaired motor performance in the HAS rats compared to their
controls. In LAS rats, early ethanol exposure produced only mild and
nonsignificant effects on motor performance. Thus, HAS rats were more vulnerable
to ethanol-induced motor deficits compared to the LAS rats. Importantly, there
were no differences in peak blood alcohol level between the lines, indicating
that vulnerability to ethanol's teratogenic effects was not due to differences in
metabolic rate. These results suggest that genetic differences in response to
alcohol may serve as a predictor for susceptibility to ethanol's teratogenic
effects.
PMID- 10680724
TI - Western diet, family history of colorectal cancer, NAT2, GSTM-1 and risk of colon
cancer.
AB - OBJECTIVE: In this study we examine the combined effects of Western diet, age at
diagnosis, and genetic susceptibility. METHODS: We use data collected as part of
an incident case-control study of colon cancer. Family history of colorectal
cancer, N-acetyltransferase (NAT2), and glutathione-S-transferase (GSTM-1) are
studied with Western diet and age at diagnosis. RESULTS: A significant
interaction between age at time of diagnosis, Western dietary pattern, and family
history of colorectal cancer (p for interaction = 0.03) was detected. Those with
a family history of colorectal cancer who ate a predominantly Western diet were
at increased risk of colon cancer (OR 14.0, 95% CI 3.9-50.1 for < or = 55 years;
OR 7.7, 95% CI 2.0-29.1 for 56-66 years; OR 1.6, 95% CI 0.8-3.2 for > or = 67
years) compared to those without a family history of colorectal cancer and low
levels of a Western diet. Associations with the Western diet were stronger than
individual components of the dietary pattern. Neither NAT2 nor GSTM-1 showed
significant interaction with Western diet. CONCLUSION: The extent to which diet
comprising a Western dietary pattern influences risk of colon cancer is dependent
on age. This dietary pattern also appears to modulate the colon cancer risk
associated with a family history of colon cancer.
PMID- 10680725
TI - World Cancer Research Fund/American Institute of Cancer Research 1997
recommendations: applicability to digestive tract cancer in Japan.
AB - OBJECTIVES: This paper reviewed analytic epidemiological studies of the major
Japanese digestive tract cancers, i.e. esophageal, stomach, colon and rectal. The
applicability of the recommendations for prevention of these cancers by the World
Cancer Research Fund/American Institute of Cancer Research (W&A) to Japan is
considered. METHODS: Papers were searched by the MEDLINE for the period 1966
through 1997. Among them, 43 relevant papers including data from Japan were
reviewed. RESULTS: Results for 11 lifestyle-related factors were considered.
Cigarette smoking was a strong and consistent, thus, convincing, risk factor for
esophageal cancer, and a possible risk factor for stomach and colorectal cancer.
Excessive consumption of alcohol was a convincing risk factor for esophageal
cancer, and a possible risk factor for stomach and colorectal cancer. Excessive
salt intake was a risk factor supported by some strong evidence but inconsistent;
therefore, it is a probable risk factor for stomach cancer and a possible risk
factor for colorectal cancer. Low physical activity was a probable risk factor
for colorectal cancer. On the other hand, sufficient intake of vegetables,
including green-yellow vegetables, and fruits was regarded as a possible
protective factor for these cancers. CONCLUSIONS: These observations were mostly
consistent with those reported by W&A; therefore the recommendations by W&A for
prevention of these cancers may be considered applicable to the current Japanese
population.
PMID- 10680726
TI - Vitamin D receptor genotype and breast cancer in Latinas (United States).
AB - OBJECTIVE: Polymorphism in the vitamin D receptor (VDR) gene has been associated
with variation in bone mineral density and with prostate cancer risk. The purpose
of this study was to determine whether polymorphism in the VDR gene may also
influence breast cancer risk. METHODS: Polymorphisms in the 5' and 3' ends of the
VDR gene were genotyped for 143 Latina women with breast cancer and 300 cohort
controls. RESULTS: Both the BsmI and poly-A polymorphisms in the 3' end of the
VDR gene were associated with breast cancer risk, with a trend for increasing
risk with increasing number of BsmI B alleles or short (S) poly-A alleles.
Compared to subjects having two long poly-A alleles (genotype LL), odds ratios
(and 95% confidence intervals) were 1.5 (1.0 2.3) and 3.2 (1.5-6.9) for subjects
having genotypes SL and SS, respectively. Compared to BsmI genotype bb, odds
ratios (and 95% confidence intervals) were 1.6 (1.1-2.5) and 2.2 (1.0-4.7) for
genotypes Bb and BB respectively. The start codon polymorphism, FokI, was not
associated with breast cancer risk. CONCLUSION: These results suggest that
polymorphic variation in or near the 3' end of the VDR gene influences breast
cancer risk in Latina women.
PMID- 10680727
TI - Partitioning linear trends in age-adjusted rates.
AB - OBJECTIVE: Surveillance of chronic diseases includes monitoring trends in age
adjusted rates in the general population. Statistics that are calculated to
describe and compare trends include the annual percent change and the percent
change for a specified time period. However, it is also of interest to determine
the contribution specific diseases make to an overall trend in order to better
understand the impact of interventions and changes in the prevalence of risk
factors. The objective here is to provide a method for partitioning a linear
trend in age-adjusted rates into disease-specific components. METHODS: The method
presented is based on linear regression. The decreasing trend in age-adjusted
cancer mortality rates for the total United States during the period 1991-96 is
analyzed to illustrate the method. RESULTS: Trends in mortality for cancers of
the colon/rectum, breast, lung/bronchus, and prostate are found to be responsible
for 75% of the decreasing trend in cancer mortality. CONCLUSIONS: It is possible
to partition an overall trend in age-adjusted rates under the assumption that it
and the trends for all mutually exclusive and exhaustive subgroups of interest
are linear.
PMID- 10680728
TI - Kidney cancer and occupational exposure to asbestos: a meta-analysis of
occupational cohort studies.
AB - OBJECTIVE: To study the risk of kidney cancer following asbestos exposure.
METHODS: We carried out a meta-analysis of the results of cohort studies of
workers predominantly exposed to asbestos. We contacted the authors of 70 cohort
studies; published results were available from the reports of 10 cohorts; we
obtained the relevant information for an additional 27 cohorts. RESULTS: The
studies included in the analysis comprised a total of 169 kidney cancer deaths
and 69 incident cases. The overall pooled standardized mortality ratio (SMR) of
kidney cancer was 1.1, with a 95% confidence interval (95% CI) of 0.9-1.3. The
pooled SMR was higher for workers with undefined asbestos exposure (SMR 1.2, 95%
CI 0.9-1.6) than for workers with either predominant chrysotile (SMR 0.9, 95% CI
0.7-1.3) or some amphibole (SMR 0.96, 95% CI 0.6-1.5) exposure. Studies with
published results had higher SMRs than studies for which information was obtained
from the authors. Studies with high asbestos exposure and an elevated SMR of lung
cancer tended to show an increased risk of kidney cancer. CONCLUSIONS: It is
unlikely that asbestos exposure is responsible for an important increase in
kidney cancer risk; however, high asbestos exposure might entail a small increase
in risk.
PMID- 10680729
TI - A multicenter case-control study of diet and lung cancer among non-smokers.
AB - OBJECTIVE: We have examined the role of dietary patterns and specific dietary
nutrients in the etiology of lung cancer among non-smokers using a multicenter
case-control study. METHODS: 506 non-smoking incident lung cancer cases were
identified in the eight centers along with 1045 non-smoking controls. Dietary
habits were assessed using a quantitative food-frequency questionnaire
administered by personal interview. Based on this information, measures of total
carotenoids, beta-carotene and retinol nutrient intake were estimated. RESULTS:
Protective effects against lung cancer were observed for high consumption of
tomatoes, (odds ratio (OR) = 0.5; 95% confidence interval (CI) 0.4-0.6), lettuce
(OR = 0.6; 95% CI 0.3-1.2), carrots (OR = 0.8; 95% CI 0.5-1.1), margarine (OR =
0.7; 95% CI 0.5-0.8) and cheese (OR = 0.7; 95% CI 0.5-1.0). Only weak protective
effects were observed for high consumption of all carotenoids (OR = 0.8; 95% CI
0.6-1.0), beta-carotene (OR = 0.8; 95% CI 0.6-1.1) and retinol (OR = 0.9; 95% CI
0.7-1.1). Protective effects for high levels of fruit consumption were restricted
to squamous cell carcinoma (OR = 0.7; 95% CI 0.4-1.2) and small cell carcinoma
(OR = 0.7; 95% CI 0.4-1.2), and were not apparent for adenocarcinoma (OR = 0.9;
95% CI 0.6-1.3). Similarly, any excess risk associated with meat, butter and egg
consumption was restricted to squamous and small cell carcinomas, but was not
detected for adenocarcinomas. CONCLUSIONS: This evidence suggests that the public
health significance of increasing vegetable consumption among the bottom third of
the population would include a reduction in the incidence of lung cancer among
lifetime non-smokers by at least 25%, and possibly more. A similar protective
effect for increased fruit consumption may be present for squamous cell and small
cell lung carcinomas.
PMID- 10680730
TI - Thyroid cancer in French Polynesia between 1985 and 1995: influence of
atmospheric nuclear bomb tests performed at Mururoa and Fangataufa between 1966
and 1974.
AB - BACKGROUND: Between 1966 and 1974, France performed 41 atmospheric nuclear weapon
tests in the Mururoa and Fangataufa atolls in French Polynesia. METHODS: We
performed a geographic analysis of thyroid cancer incidence, using data from the
cancer registry of French Polynesia, medical evacuation files, insurance records
and hospital and pathology laboratory files. RESULTS: A total of 153 thyroid
cancers were diagnosed between 1985 and 1995 in the population born before 1976
and residing in French Polynesia. The incidence of thyroid cancer was 2-3 times
larger in French Polynesia than in Maoris of New Zealand and Hawaiians of Hawaii.
Based on few cases, a nonsignificant (p = 0.1) increase with decreasing distance
between Mururoa and the birth place was observed in women born between 1950 and
1975 for thyroid cancer. CONCLUSION: Because the difference between Polynesian
and reference populations was not larger for Polynesians who were children during
the tests than for Polynesians born earlier; as would be expected in the case of
radioiodine contamination, the high thyroid cancer rates in French Polynesia
could hardly be attributed to radioiodine fallout. Nevertheless, a surveillance
of the population born close to Mururoa is necessary to confirm or deny the
existence of a higher risk of thyroid cancer in this population.
PMID- 10680731
TI - Premorbid diet in relation to survival from prostate cancer (Canada).
AB - OBJECTIVES: To examine the associations between prediagnostic energy, fat, and
vitamin A intake and survival from prostate cancer. METHODS: Two hundred and
seven cases of prostate cancer from Toronto and 201 cases from Vancouver provided
diet histories at diagnosis between 1989 and 1992 and were followed for survival
from prostate cancer. After exclusions for various reasons, 263 cases (135 from
Toronto, 128 from Vancouver) were analyzed in Cox proportional hazards models.
RESULTS: Following adjustments for clinical stage, histologic grade, and other
factors, significantly lower risks of dying from prostate cancer in the highest
compared with the lowest tertiles of monounsaturated fat intakes were observed in
each city and in the combined city analyses (combined cities: hazard ratio [HR] =
0.3; 95% confidence interval (CI) = 0.1-0.7). Survival from prostate cancer was
significantly better for cases in the highest tertile of energy intake in Toronto
(HR = 0.1; CI = 0.01-0.6) in contrast to that in Vancouver where these cases did
relatively worse (HR = 2.6; CI = 0.6-10.7). Other nutrients were either not
consistently or not significantly associated with prostate cancer survival in the
two cities. CONCLUSIONS: This bi-center cohort study observed a consistent and
significant inverse association between the premorbid intake of monounsaturated
fat and risk of death from prostate cancer. The inconsistent results for energy
intake between cities could potentially be attributed to non-respondent bias in
Toronto.
PMID- 10680732
TI - Prostate cancer in Saskatchewan Canada, before and during the PSA era.
AB - OBJECTIVES: The purpose of this study was to describe changes in the incidence of
prostate cancer and in survival of diagnosed cases, as well as prostate cancer
specific mortality, during a period spanning the introduction of prostate
specific antigen (PSA) testing in Saskatchewan in 1990. METHODS: All cases of
neoplasms of the prostate (ICD-O = C61.9) diagnosed in Saskatchewan from 1970 to
1997 inclusive, were identified in the Saskatchewan Cancer Registry. A subgroup
of adenocarcinomas was defined for further study. Age-adjusted and age-specific
incidence rates, and actuarial and relative survival were calculated according to
time period of diagnosis. Age-adjusted and age-specific mortality rates from
prostate cancer were also calculated for each time period, using Vital Statistics
data. RESULTS: The age-adjusted incidence of prostate cancer was 60.5 per 10(5)
in 1970, rising gradually to 101.5 per 10(5) in 1989. In 1990, incidence rose
much more sharply, reaching a peak of 163.1 per 10(5) in 1993, after which it
began to fall. This sharp increase coincided with the introduction and increasing
use of the PSA test in the province. Relative survival of prostate cancer
patients was stable from the late 1970s through the 1980s, then improved markedly
in the 1990-94 period. After the introduction of the PSA test, the relative risk
of death for prostate cancer patients was only about 60% of what it had been
throughout the previous 15 years. Prostate cancer-specific death rates did not
change from the early 1980s to the end of the study period. CONCLUSIONS: The
above data are consistent with earlier diagnosis of prostate cancer due to PSA
screening. Because mortality has not yet changed, it is premature to recommend
widespread screening of asymptomatic men.
PMID- 10680733
TI - Research questions concerning insulin-like growth factor-1.
AB - The Harvard Center for Cancer Prevention (HCCP) convened a workshop on June 4,
1999 in Boston, MA. The objectives of the meeting were to briefly review the
current state of knowledge in the area of insulin-like growth factor-1 physiology
as related to cancer risk, to define the area's major remaining gaps in
knowledge, and lastly to discuss research opportunities.
PMID- 10680734
TI - Illnesses caused by smoking cigarettes.
PMID- 10680735
TI - Response to the letter by Maria Feychting and Anders Ahlbom (Cancer Causes and
Control 10: 637, 1999.) Why is the cancer pattern so different among visually
impaired persons in Finland and Sweden?
PMID- 10680736
TI - Newcastle disease virus (NDV): brief history of its oncolytic strains.
AB - BACKGROUND: While genetically engineered viruses are now being tested for the
virus therapy of human cancers, some naturally occurring viruses display
unmatched oncolytic activity. Newcastle disease virus (NDV) excels as an
oncolytic agent. OBJECTIVES: As its virulence versus attenuation can be explained
on molecular biological bases, it may be possible to develop or select highly
oncolytic strains of NDV without adverse toxicity. STUDY DESIGN: Questions are
posed as to the mechanisms of viral oncolysis, the appropriateness of tests to
predict oncolytic activity of a given NDV strain and the best modes of
administration for oncolytic effects. Answers are provided based on specific data
or on considerations drawn from experience (the authors use NDV oncolysates to
immunize against melanoma and kidney carcinoma) or from analogous clinical
situations (therapeutic use of mumps or measles viruses). RESULTS AND
CONCLUSIONS: NDV oncolysates probably suit better for immunotherapy (providing
also active tumor-specific immunization) than massive repeated inoculations of
NDV strains, especially when the NDV strain used is not proven to be oncolytic by
appropriate pre-clinical tests.
PMID- 10680737
TI - The possible role of human cytomegalovirus (HCMV) in the origin of
atherosclerosis.
AB - BACKGROUND: The biological properties of some herpesviruses such as the ability
of latent persistency in the host cells and the presence of viral DNA in
atherosclerotic lesions, suggest the possible role of herpesviruses in the
development of atherosclerosis. Although many authors proved the presence of
viral DNA in arterial wall tissue, the role of herpesviruses in the origin and
progress of atherogenesis still remains unclear. OBJECTIVES: The aim of this
study was to confirm the presence of viral DNA in arterial wall and to associate
the presence of these viruses with the development of atherosclerosis in patients
with ischemic heart disease (IHD). STUDY DESIGN: A possible role of HCMV, EBV and
HHV6 in the development of atherosclerosis was tested in 244 IHD patients and 87
coronarographically negative controls. The presence of viral DNA in aortic and
venous walls, as well as in a peripheral blood samples was tested by the use of
polymerase chain reaction (PCR) accompanied by, immunological tests for anti
virus antibodies IgM and IgG types for all experimental groups. RESULTS: The
genomic DNA of HCMV was found in 76 and 59%, DNA of EBV in 59 and 50%, and DNA of
HHV6 in 0.08 and 0.0%, of arterial walls of IHD patients and non-ischemic control
group, respectively. No viral DNA was found in venous samples. Significant
association (P < 0.01) has been proved between CMV infection and IHD.
CONCLUSIONS: Our results suggest that HCMV and EBV can be found in the arterial
wall, so that the arterial wall could be a potential site of persistency of those
viruses. We also proved a significant association between the presence of HCMV
DNA in aortic walls and atherosclerosis. Despite of the high genetic and
biological similarity between CMV and HHV6 no substantial role of HHV6 in
atherosclerosis has been proved.
PMID- 10680738
TI - Recent advances in the therapy and prevention of CMV infections.
AB - The introduction of highly active antiretroviral therapy (HAART) for HIV has had
a major impact on the treatment of CMV disease in HIV-infected individuals. There
is mounting evidence that in patients with CMV retinitis who have a sustained
response to HAART, CMV maintenance treatment can be discontinued without relapse
of retinitis. In HAART-naive individuals with newly diagnosed CMV retinitis, the
optimal timing for the initiation of HAART relative to the start of anti-CMV
treatment is currently unknown. New local therapies for CMV retinitis (e.g.
ganciclovir implant, the new antisense compound fomivirsen) provide treatment
options in situations where high local drug delivery is warranted. A treatment
algorithm for CMV disease in the HAART era is proposed. In the transplant
setting, ganciclovir and foscarnet remain the major compounds used for treatment
of CMV disease. In marrow and stem cell transplant recipients, CMV pneumonia
still carries a high mortality. Ganciclovir in combination with CMV-specific
immunoglobulin or regular intravenous IG remains the treatment of choice for CMV
pneumonia; extended antiviral maintenance for several months is recommended in
patients with continued immunosuppression. Preemptive treatment based on
virologic markers (e.g. pp65 antigenemia, CMV DNA) has been very successful in
reducing the incidence of early CMV disease in the transplant setting. The
duration of preemptive treatment should be guided by the underlying
immunosuppression and virologic markers. Late CMV disease is a challenge in
marrow and stem cell transplant recipients, and occurs increasingly in highly
immunosuppressed solid organ transplant recipients as well. Recent advances in
prophylaxis strategies include oral ganciclovir for liver transplant recipients
and valacyclovir for kidney transplant recipients.
PMID- 10680739
TI - Rapid detection of respiratory viruses by centrifugation enhanced cultures from
children with acute lower respiratory tract infections.
AB - BACKGROUND: Acute respiratory tract infection (ARI) is the major cause of
morbidity and mortality in young children in developing countries. Information on
viral aetiology in ARI in India is very limited. OBJECTIVE: The aim of the study
was to define the role of viruses in acute lower respiratory tract infections
(ALRTI) in children in India using centrifugation enhanced cultures followed by
indirect immunofluorescence (IIF). STUDY DESIGN: Nasopharyngeal aspirates (NPAs)
were collected from children from September 1995 to April 1997, attending
paediatric clinic of All India Institute of Medical Sciences (AIIMS) with
symptoms of ALRTI. Virus isolation was done by centrifugation enhanced cultures
using HEp-2, LLC-MK2 and MDCK cells. The viruses were identified at 24-48 h post
inoculation by IIF staining using monoclonal antibodies to respiratory syncytial
virus (RSV), parainfluenza virus (PIV), influenza virus and adenovirus. RESULTS:
Of 200 NPA samples, 89 (44.5%) were positive for one or more viral pathogens. RSV
was detected in 34 (17%) of all ALRTI cases followed by influenza viruses in 29
(14.5%), PIVs in 23 (11.5%) and adenoviruses in three (1.5%). In 79 children with
bronchiolitis, RSV was most frequently isolated (25%) pathogen, while in
bronchopneumonia cases (101) the most common viral pathogen was influenza virus
(17%). In eight cases (4%) of ALRTI dual infections were detected. In 100 NPA
specimens IIF staining on direct cell smears was carried out and viruses were
detected in only 17%. RSV and influenza virus infection peaked from September to
December, where as PIV infections were more frequent from January to April.
CONCLUSION: Respiratory viruses accounted for 44.5% of cases of ALRTI in India
and the results of viral aetiology could be given in 24-48 h using centrifugation
enhanced cultures. RSV was the most common viral agent associated with ALRTI in
children under 5 years of age with greater association with bronchiolitis.
PMID- 10680740
TI - Seroprevalence of viral childhood infections in Eritrea.
AB - BACKGROUND: The seroprevalence of viral childhood infections in Africa has not
been thoroughly investigated. The relatively recently discovered human parvovirus
B19 (B19) and human herpesvirus 6 (HHV-6) have received particularly little
attention. OBJECTIVE: To investigate the seroprevalence of viral childhood
infections in different Eritrean populations and to define groups at high risk
for infection. STUDY DESIGN: Five population groups in Eritrea have been examined
to define the prevalence of specific antibodies to several childhood viruses. The
study population of more than 400 persons consisted of children, pregnant women,
female sex workers and members of a secluded tribe called Rashaida. RESULTS: All
groups showed a high prevalence of antibodies to measles and HHV-6 (> 85%). For
rubella, the seroprevalence was very high in all adult groups (93-99%) except the
Rashaida group (71%). The mumps prevalence was surprisingly low in the Rashaida
group (29%) compared to 46-85% in the other adults. Late encounter of mumps and
rubella was also observed among the Rashaidas. The pattern of antibodies to B19
showed a higher seroprevalence in all groups (56-91%) compared to what has been
reported from the western world. CONCLUSION: The findings represent what might be
expected in an unvaccinated population. The exception was the Rashaidas, which
had low seroprevalences and late encounter of mumps and rubella. This is of
importance because it makes this tribe vulnerable to these infections, which are
associated with complications when acquired in adult age. Also noteworthy is the
high frequency of antibodies to HHV-6 and particularly B19 in all groups,
indicative of an early encounter of both these viruses.
PMID- 10680741
TI - No apparent effect of cidofovir in epidermodysplasia verruciformis.
AB - This paper reports the failure of a patient suffering from Epidermodysplasia
verruciformis, characterised by widespread infection of the skin with human
papillomaviruses, to respond to topical and systemic treatment with the antiviral
agent, Cidofovir, despite its previously demonstrated effectiveness against a
range of different papillomavirus-associated conditions.
PMID- 10680742
TI - Comparison of six nucleic acid extraction methods for detection of viral DNA or
RNA sequences in four different non-serum specimen types.
AB - BACKGROUND: Extraction of viral nucleic acids from serum samples is widely used
in diagnostic pathology tests. However, the heterogeneous nature of non-serum
samples may contribute to variations in the yields of viral nucleic acids with
different extraction methods and specimen types. OBJECTIVES: Six different
methods were compared for optimal extraction of viral DNA or RNA from four types
of non-serum specimens. STUDY DESIGN: The DNA viruses used were herpes simplex
virus and cytomegalovirus. The RNA viruses were poliovirus, rotavirus and small
round structured virus. The specimens used were from respiratory, genital, faecal
and peripheral blood mononuclear cell samples. The extracted nucleic acids were
amplified by PCR and detected in an enzyme immunoassay using digoxygenin-labelled
amplicons. RESULTS AND CONCLUSIONS: For extraction of viral DNA, the phenol
chloroform method yielded the highest amount of DNA as judged by endpoint
titration. The three methods compared for extraction of viral RNA used guanidine
isothiocyanate and the QiaRNA kit was shown to yield the highest amount of viral
RNA.
PMID- 10680743
TI - Asymptomatic shedding of herpes simplex virus into the oral cavity of patients
with atopic dermatitis.
AB - BACKGROUND: Asymptomatic shedding of herpes simplex virus (HSV) into the oral
cavity is one of the important sources of the infection. OBJECTIVES: We
anticipated that the oral cavity is one of the possible sites of initial
recurrence in patients with recurrent-type eczema herpeticum. MATERIALS AND
METHODS: Oral swabs were collected from 24 patients with atopic dermatitis aged
from 13 to 29 years, and as a control population, from seven patients with skin
diseases other than atopic dermatitis aged from 16 to 29 years. We tried to
detect HSV DNA by the polymerase chain reaction method. RESULTS: HSV DNA was
detected in eight out of 31 specimens from 15 patients with facial lesions of
atopic dermatitis, and in one of 15 specimens from nine patients without facial
atopic dermatitis, and in two of ten specimens from seven patients with other
skin diseases. However, these differences are not statistically significant.
Moreover, no patients developed eczema herpeticum during the period of this
study. CONCLUSIONS: These results suggest that facial atopic dermatitis may not
lead to oral HSV shedding, and there may be little opportunity for the virus in
the oral cavity to contaminate other skin sites in adolescents and adults.
PMID- 10680744
TI - Hepatitis E virus in Cuba.
AB - The hepatitis E virus (HEV) has a global distribution and is known to have caused
large waterborne epidemics of icteric hepatitis. The transmission is primarily
fecal-oral. Some reports have suggested parenteral transmission of HEV from its
association to hepatitis B or hepatitis C infection, or due to the development of
hepatitis E after blood transfusion. Though most of the developing countries in
Asia and Africa have been shown to be endemic for HEV infection, studies in the
Latin American countries have been limited to Mexico, Brazil and Venezuela. We
have developed an enzyme immunoassay (EIA) for IgM and IgG antibodies to a
recombinant protein containing antigenic epitopes of the ORF3 region of the HEV.
This system, as well as a commercial kit that includes ORF2 and ORF3 antigenic
epitopes, were used to study the prevalence of anti-HEV antibodies in a sample of
Cuban blood donors, acute hepatitis cases and individuals subjected to
plasmapheresis. The incidence of anti-HEV IgM was compared with other viral
hepatitis markers. Our findings suggest that infections due to HEV are an
important viral cause of sporadic hepatitis in Cuba, and that HEV is endemic to
this region of the world.
PMID- 10680745
TI - Concanavalin A-induced hepatitis in mice is prevented by interleukin (IL)-10 and
exacerbated by endogenous IL-10 deficiency.
AB - One single intra-venous (i.v.) injection of Concanavalin A (Con A) into mice
provokes a cell-mediated immunoinflammatory hepatitis. We have presently
evaluated the immunopharmacological effects of exogenous interleukin (IL)-10 and
the role of endogenous IL-10 in this model by using exogenous IL-10, anti-IL-10
monoclonal antibody (mAb) and mice with disrupted IL-10 gene (IL-10 KO mice).
Whilst exogenous IL-10 administered in a prophylactic (1 h prior to Con A) and
even "early" therapeutic fashion (30 min after Con A) reduced the elevation of
transaminase activities in plasma in a dose-dependent manner, observed in control
mice, these biochemical markers of liver injury were significantly increased both
in IL-10 KO mice as well as in those receiving anti-IL-10 mAb. Interestingly,
doses of Con A lower than 20 mg/kg that were only capable of inducing slight
serological signs of hepatitis in mice, exerted marked hepatitic effects when
administered to either anti-IL-10 mAb-treated mice or to IL-10 KO mice. The
disease modulating effects of exogenous IL-10 and either genetical or
pharmacologically-induced IL-10 deficiency were associated with profound and
opposite modifications of the Con A-induced increase in the circulating levels of
IFN-gamma and TNF-alpha. Relative to control animals, the blood levels of these
cytokines were diminished in IL-10-treated mice and augmented in both IL-10 KO
mice and anti-IL-10 mAb-treated mice. These results prove the physiological
antiinflammatory role of endogenous IL-10 in Con A induced hepatitis and the
beneficial effects of IL-10 treatment to prevent this condition.
PMID- 10680746
TI - Serum soluble HLA-DR antigens in autoimmune hepatitis.
AB - To investigate the significance of HLA-class II, especially DR antigens, in
autoimmune hepatitis (AIH), the serum concentrations of soluble HLA-DR antigen
(sDR) were measured in 16 patients with AIH. The expression of HLA-DR antigens in
the liver tissues of AIH patients was also studied by immunohistochemistry. AIH
at diagnosis showed markedly higher serum sDR levels than controls, in which the
liver tissues exhibited positive staining of HLA-DR antigens. Seven patients
received corticosteroid therapy, in whom the serum sHLA-DR concentration was
reduced dramatically from activated to remission stage. In sequentially follow-up
cases, sDR correlated well with the disease activity, and also with the change of
surface DR expression in the liver. A single major band with a molecular size of
60 kDa was detected, both in patient's sera and in normal control sera, by
Western blotting. In conclusions, serum sHLA-DR level could be a marker
reflecting immunological activity of the disease.
PMID- 10680747
TI - The 5S rRNA is associated with Ro60 ribonucleoprotein and is co-precipitated with
hYRNAs by anti-Ro antibodies.
AB - Ro particles are conserved molecules that contain a YRNA and various Ro proteins,
which are recognized by autoimmune sera from patients with lupus erythematosus or
Sjogren's syndrome. The Ro60 ribonucleoprotein (RNP) forms complexes with certain
5S rRNAs, in such a manner that Ro60 could participate in the control of 5S rRNA
production. The present studies were carried out to explore the interaction of Ro
components, and to address the question whether Ro60 RNP binds simultaneously 5S
rRNA and hYRNA. Anti-Ro60 antibodies were used to immunoprecipitate the RNA.
Immunoprecipitates were reverse transcribed with specific oligonucleotides and
the resulting cDNAs from 5S and hY4 were amplified by PCR. We found that 5S rRNA
is complexed with hY4 and hY5 RNAs by means of the Ro60 RNP. Moreover, by in situ
hybridization assays we were able to demonstrate that these molecules have a
similar nuclear distribution. According to these results, it seems reasonable to
assume that the Ro60 protein could be involved in ribosome assembly.
PMID- 10680748
TI - Serial changes in the galactosylation of autoantibodies and serum IgG in
autoimmune haemolytic anaemia.
AB - A number of systemic autoimmune diseases are associated with increased levels of
the agalactosyl (G0) IgG isoforms that lack a terminal galactose from the C(H)2
domain oligosaccharide. The aims were to determine whether there are also
persistently high levels of G0 autoantibodies or serum IgG in autoimmune
haemolytic anaemia (AIHA), and whether any changes in galactosylation over time
are related to the course of disease. Autoantibodies eluted from red blood cells,
and serum IgG, were obtained from a patient with chronic AIHA over a 21 month
period, and the degree of galactosylation measured using a lectin-binding assay.
There were wide fluctuations in the galactosylation of autoantibody and serum
IgG, but these changes were unrelated to the severity of the anaemia. The
galactosylation of autoantibody and serum IgG varied independently, and the
autoantibodies were preferentially G0 in comparison with serum IgG in only half
of the serial samples. We conclude that AIHA differs from other, systemic
autoimmune conditions in that high levels of G0 autoantibodies or serum IgG are
not persistent, and that changes in galactosylation do not parallel the course of
disease.
PMID- 10680749
TI - Anti-Beta 2-glycoprotein I antibody isotype and IgG subclass in antiphospholipid
syndrome patients.
AB - Beta 2-glycoprotein I (beta2-GPI) is an antigenic target recognised by
antiphospholipid antibodies found in association with the antiphospholipid
syndrome (APS). In this study, the prevalence of Immunoglobulin M (IgM) and IgA
anti-beta2-GPI antibodies was examined in APS patients and compared with IgG
antibodies. In addition the value of measuring antibody isotypes and IgG subclass
was investigated in the laboratory diagnosis of APS. A solid phase enzyme linked
immunosorbent assay was established to measure IgG, IgM and IgA and IgG subclass
antibodies to beta2-GPI in patients with APS and a variety of other thrombotic
and non-thrombotic disorders. Raised levels of IgM anti-beta2-GPI antibodies were
observed in 65% of patients with APS, 21% with systemic lupus erythematosus
(SLE), 23% with rheumatoid factor, 4% with stroke, 5% carotid artery stenosis
(CAS), 17% with a biological false positive serology for syphilis, 43% with
infectious mononucleosis (IM) and 27% with human immunodeficiency virus (HIV).
The median value for IgM antibodies to beta2-GPI for all these groups ranged from
2 to 7 arbitrary units (AU). Elevated levels of IgA antibodies to beta2-GPI were
found in patients with APS (47%), SLE (13%), rheumatoid factor (26%), CAS (48%),
stroke (25%), VDRL false positive serology for syphilis (33%), IM (47%) and HIV
(7%). The median value of IgA antibodies to beta2-GPI in all of these groups
ranged from 2 to 4 AU. Conversely the median value for IgG anti-beta2-GPI in APS
patients was 112 AU compared to 1-4 AU in the other conditions examined. The
presence of IgM and IgA antibodies to beta2-GPI was much less specific and
sensitive for APS than IgG, with raised levels of these isotypes seen in a
variety of thrombotic and non-thrombotic disorders. Elevated levels of IgG1,
IgG2, IgG3 and IgG4 antibodies to beta2-GPI were detected in APS patients. While
all four IgG anti-beta2-GPI antibody subclasses were represented in APS patients
there appeared to be a significant overall skewing towards to the IgG2 subclass.
PMID- 10680750
TI - Reduced in vitro production of interferon-gamma, interleukin-4 and interleukin-12
and increased production of interleukin-6, interleukin-10 and tumour necrosis
factor-alpha in systemic lupus erythematosus. Weak correlations of cytokine
production with disease activity.
AB - Production of cytokines in unstimulated and mitogen-stimulated cultures were
evaluated by ELISPOT in 34 SLE patients with low to moderate disease activity and
23 healthy controls. Significantly reduced production of IFN gamma, IL4 and IL12
and significantly increased production of IL6, IL10 and TNF alpha were found in
patients with SLE. Regression analysis revealed that production of all six
cytokines tended to decrease with increasing disease activity, but negative
correlation with SLEDAI was significant (p < 0.05) only for PHA-stimulated IL4,
unstimulated and PHA-stimulated IL10 and SAC-stimulated IL6. Negative correlation
of stimulated and unstimulated IL6 and TNF alpha production with anti-DNA
antibody levels were also significant.
PMID- 10680751
TI - Expression of HSP-65 in jejunal epithelial cells in patients clinically suspected
of coeliac disease.
AB - BACKGROUND: Coeliac disease (CD) can be classified both clinically and
biologically an autoimmune disease. A close relationship obtains between heat
shock proteins (HSPs) and numerous autoimmune diseases. HSPs are overexpressed
when protecting the host against environmental insult. We sought here to
establish whether dietary gluten is such a stress stimulus in patients clinically
suspected of CD, and whether the expression of HSP-65 associates with densities
of intraepithelial gammadelta+ T cells and/or with expression of mucosal HLA-DR.
METHODS: Seventy-eight children with clinical suspicion of CD underwent a jejunal
biopsy. Monoclonal antibodies were used to stain jejunal epithelial HSP-65,
intraepithelial lymphocytes and mucosal HLA-DR. Serum IgA-class endomysial
autoantibodies (EMA) were measured by an indirect immunofluorescence method. CD
susceptibility HLA DQA1*0501 and DQB1*0201 alleles (HLA DQ2) were determined.
RESULTS: Enhanced expression of epithelial cell mitochondrial HSP-65 was found in
80% (16/20) of coeliacs and in 24% (14/58) of children excluded for the disease,
but in only 7% (2/28) of control subjects (p < 0.001, p = 0.049, respectively).
Children with enhanced expression of HSP-65 had significantly higher gammadelta+
T cell densities than those with normal HSP-65 expression. A clear association
between HSP-65 and serum IgA-class EMA were also ascertained in patients with
normal jejunal mucosal morphology. HLA DQ2 positivity did not correlate with the
HSP-65 expression. CONCLUSIONS: Gluten might be an environmental insult not only
in CD patients but also in some patients excluded for the disease on biopsy.
Enhanced expression of epithelial cell stress proteins might be an indicator of
such an insult.
PMID- 10680752
TI - Factors involved in the pathogenesis of neutrophilic vasculitis in MRL/Mp-lpr/lpr
mice: a model for human microscopic angiitis.
AB - Anti-neutrophil cytoplasm antibodies (ANCA) directed against myeloperoxidase
(MPO) are detected in patients with microscopic angiitis. Human MPO
autoantibodies stimulate neutrophil degranulation in vitro and are thought to be
pathogenic. We have previously shown that MRL-lpr mice with MPO autoantibodies
have a higher incidence of vasculitis than their seronegative littermates. The
aim of the present study is to determine the relationship between MPO
autoantibodies and microscopic angiitis. The neutrophil binding properties of
anti-MPO monoclonal antibodies (mAbs) from MRL-lpr mice were tested using murine
heterophils (neutrophils) present in blood and induced peritoneal exudates. MRL
anti-MPO mAbs selectively bind activated neutrophils which express MPO in vitro.
The pathogenicity of an IgG2b anti-MPO mAb, C6, was investigated in vivo. Anti
MPO mAb, C6 was administered to young MRL mice which had been primed with
exogenous TNF alpha to induce neutrophil activation and expression of MPO.
Neutrophilic vasculitis similar to microscopic angiitis occurred in 33% of MRL
mice which had been treated with anti-MPO mAb. The lesions were mainly restricted
to sites of previous endothelial insult which suggests an active role for injured
endothelium in this pathology.
PMID- 10680753
TI - Amygdala, hippocampus and discriminative fear conditioning to context.
AB - Various measures of fear have been shown to condition to a fearful context with
different acquisition rates (Antoniadis EA, McDonald RJ. Fear conditioning to
context expressed by multiple measures of fear in the rat, Behav Brain Res
1999;101(1):1-14). Freezing, locomotion, urination and preference are 'fast'
measures of fear in that they discriminatively condition to context after a
single training session, while ultrasonic vocalizations and defecation are 'slow'
measures of fear given that they condition following three training sessions. In
the present experiment we sought to assess the contribution of the amygdala and
the hippocampus in this form of learning. Existing views differ on the degree of
involvement of each memory structure. This discord probably emerges from the
common use of non-discriminative paradigms and the assessment of a single measure
of fear. With the use of a discriminative paradigm and the assessment of multiple
measures of fear, results indicate that the amygdala is a memory structure that
selectively mediates the conditioning of heart rate, and the hippocampus
selectively mediates the conditioning of defecation and body temperature. The
conditioning of preference, locomotion, freezing and ultrasonic vocalizations,
necessitate the participation of both memory structures while the conditioning of
urination does not seem to require the participation of either the hippocampus or
the amygdala. The proposed view ascribes an equal role in fear conditioning to
both the amygdala and the hippocampus.
PMID- 10680754
TI - Visually guided locomotion and computation of time-to-collision in the mongolian
gerbil (Meriones unguiculatus): the effects of frontal and visual cortical
lesions.
AB - Past research has indicated that many species use the time-to-collision variable
but little is known about its neural underpinnings in rodents. In a set of three
experiments we set out to replicate and extend the findings of Sun et al. (Sun H
J, Carey DP, Goodale MA. Exp Brain Res 1992;91:171-175) in a visually guided task
in Mongolian gerbils, and then investigated the effects of lesions to different
cortical areas. We trained Mongolian gerbils to run in the dark toward a target
on a computer screen. In some trials the target changed in size as the animal ran
toward it in such a way as to produce 'virtual targets' if the animals were using
time-to-collision or contact information. In experiment 1 we confirmed that
gerbils use time-to-contact information to modulate their speed of running toward
a target. In experiment 2 we established that visual cortex lesions attenuate the
ability of lesioned animals to use information from the visual target to guide
their run, while frontal cortex lesioned animals are not as severely affected. In
experiment 3 we found that small radio-frequency lesions, of either area VI or of
the lateral extrastriate regions of the visual cortex also affected the use of
information from the target to modulate locomotion.
PMID- 10680755
TI - The Dalila effect: C57BL6 mice barber whiskers by plucking.
AB - Group-housed laboratory mice are frequently found with their whiskers and facial
hair removed. It has been proposed that dominant mice are responsible for
barbering the hair of the recipient (the Dalila effect), and early studies
suggest that the hair is removed by nibbling. In the present study, pairs of
C57BL6 mice, composed of a barber and recipient, were separated to allow hair to
regrow. The animals were then placed together in an observation box and their
social behavior was videorecorded. The videorecording was subjected to frame-by
frame analysis. Barbering was found to occur during acts of mutual grooming.
During grooming, one member of a mouse pair removed the vibrissae of the
conspecific and did so by grasping individual whiskers with the incisors and
plucking them out. Although plucking appeared 'painful', recipients were passive
in accepting barbering, and even pursued conspecifics for further grooming. Other
measures indicated that barbers were heavier than recipients and brain weights
were not different. Although cortical barrel fields appeared normal to cytochrome
oxidization and zinc staining, Golgi analysis of layer three, barrel-field
basilar dendrites indicated changes in cell morphology. The results are discussed
in relation to the hypothesis that barbering is an expression of social
dominance, the origins of the barbering behavior, and the consequences of
barbering on brain function.
PMID- 10680756
TI - Use of a delayed non-matching to position task to model age-dependent cognitive
decline in the dog.
AB - Spatial learning and memory in young and old dogs was studied in a series of
experiments using a delayed non-matching to position (DNMP) paradigm. Past
research from our laboratory has suggested that aged dogs perform more poorly on
a version of the DNMP task compared to young dogs [Head et al., Spatial learning
and memory as a function of age in the dog, Behav. Neurosci. 1995;109(5):851
585]. We have now extended these findings by testing a large number of dogs on
three different variations of the DNMP paradigm to evaluate different aspects of
spatial learning and memory. Our results indicate that: (1) aged dogs show
impaired spatial learning compared to young dogs, (2) aged dogs display spatial
working memory deficits compared to young dogs, (3) young dogs have a greater
maximum working spatial memory capacity than old dogs and (4) we can use the DNMP
paradigm to cognitively categorize different subsets of aged dogs. These data
indicate that the DNMP paradigm can serve as a valuable tool to evaluate age
dependent cognitive dysfunction in the canine.
PMID- 10680757
TI - Effects of NMDA receptor blockers on cocaine-stimulated locomotor activity in
mice.
AB - Effects of MK-801 and ketamine, N-methyl-D-aspartate (NMDA) receptor blockers, on
cocaine-stimulated locomotor activity were investigated in male Swiss-Webster
mice. MK-801 (0.25, 0.5, 1.0 and 2.5 mg/kg), ketamine (10, 25 and 50 mg/kg) or
saline was injected 20 min before cocaine (5, 10 and 20 mg/kg i.p.). Locomotor
activity was measured for 30 min immediately following cocaine treatment. All
doses of the drugs were also tested for ability to depress or stimulate locomotor
activity in the naive (no cocaine-treated) mice. Cocaine produced a dose
dependent increase in locomotor activity that was blocked dose-dependently by MK
801 or ketamine. The blockade by MK-801 was more prominent than by ketamine. Our
results may suggest that cocaine-induced locomotor stimulation in mice is
modulated via NMDA receptor mediated mechanisms.
PMID- 10680758
TI - Transient focal cerebral ischemia induces sensorimotor deficits in mice.
AB - Rodents have been extensively used for experimental stroke research with rat and
gerbil the preferred species. With the advent of transgenesis and gene targeting
the number of mutant mouse strains is rapidly increasing. Thus, mouse models of
stroke will be of great importance in the analysis of genetic factors affecting
stroke. Demonstrating long-term functional recovery is of paramount importance
for the pharmacological evaluation of putative stroke therapies. In the present
paper we induce mild focal cerebral ischemia by tandem occlusion of the right
middle cerebral artery (MCA), via craniotomy, together with the common carotid
artery for 45 min in C57BL/6 strain of mice. The effects of ischemia were
evaluated acutely by MRI and long-term (> 3 weeks) sensorimotor functional
deficits were analyzed using a number of behavioral paradigms including the
rotorod, wire hang, horizontal surface approach, eye-closure reflex, and T-maze
tests. Although the induced brain damage is mild we show that it leads to clearly
detectable and significant sensorimotor defects associated with fine motor
coordination, balance, and postural and sensory reflexes. We conclude that the
applied behavioral tests will be useful in the analysis of stroke in mutant mice.
PMID- 10680759
TI - D1 and D2 dopamine receptor agonists improve deficits in motor programming of
cats with a 6-hydroxydopamine lesion in the A8 cell group.
AB - Recently, it has been shown that a small 6-hydroxydopamine lesion in the A8 cell
group of cats trained to walk on a treadmill produces long-lasting deficits (Arts
and Cools, 1998, Behav. Neurosci. 112; pp. 102-105). Some deficits could be
attributed to a hypofunction of A9 cells, that is a reduced ability to switch
arbitrarily motor patterns, and other deficits to a hyperfunction of A10 cells,
that is an improved ability to switch motor patterns with the help of cues. This
experiment was repeated in this study and the elicited behavioural symptoms were
systemically treated with the dopamine D1 receptor agonist SKF 81297 and dopamine
D2 receptor agonist LY 171555. The results show that a cocktail of these agonists
restored both the lesion-induced reduced ability to switch arbitrarily motor
patterns and the lesion-induced increased ability to switch motor patterns with
the help of cues, suggesting that this treatment restored the functional
misbalance between the A9 and A10 cells.
PMID- 10680760
TI - The mechanisms of movement preparation: a precuing study.
AB - It is well known that precues about the possible locations of upcoming targets
reduce the manual reaction time. The present study investigates at which stage of
the sensorimotor system such precues act. Several light dots were displayed as a
precue; one of them became the target, and subjects had to produce a manual
response to the target as fast as possible. Exp. A varied independently the
number of precues and the area of space they occupy; we found that the reaction
time of pointing movements depended on spatial extent, but not on the number of
choices. The outcome was similar in Exp. B, where subjects produced stereotyped
'tapping' movements irrespective of target position. Taken together, both
findings support the view that precues act mainly at a stage concerned with the
internal representation of space, rather than with response selection or movement
preparation. The effects of precues were preserved when subjects fixated
throughout the precuing period (Exp. C), but not when precue and target positions
were uncorrelated (Exp. D). These findings do not support the alternative
interpretations, that precues act by guiding the eyes into the vicinity of
targets, or by elevating the subjects' arousal level.
PMID- 10680761
TI - The effect of an external load on the force and timing components of mentally
represented actions.
AB - The chronometry of real and imagined movements was investigated in a group of
eight subjects under varying conditions. The visually-guided pointing task was
used to investigate the speed for accuracy trade-offs that occur as target size
is varied for both real and imagined performance. The task was performed both
with and without an external load of 2 kg. For the no-load condition and load
conditions, the speed for accuracy trade-off for both real and imagined
performance conformed to Fitts' law. Movement durations of real movements
remained largely unaffected by the addition of the load, however, movement
durations of imagined movements increased significantly with the addition of the
load. These patterns of results suggest that the weight disrupted the force
calculation component of imagined movements but not the relative timing.
PMID- 10680762
TI - Sensory and motor aspects of the coital reflex in the spinal male rat.
AB - In the present study the sensory and motor aspects of the coital reflex model in
male rats were evaluated. Electromyographic reflex activity after mechanical
stimulation of the urethra, penis and scrotal skin was recorded in all genital
muscles. The possibility that a facilitatory mechanism of these muscular
responses was located in the rat spinal cord was evaluated by removing the
genital afferents. Results showed that urethral, penile and scrotal stimulation
evoked the coital reflex in all genital muscles. Similarly, coital responses were
obtained spontaneously in deafferentated animals. The parameters among the motor
patterns evoked with the different mechanical stimuli were very similar.
Parameters of spontaneous motor patterns were not importantly different from
those obtained reflexively. A conspicuous difference between these responses was
the presence of an after-discharge activity in genitally-stimulated animals.
Additionally, it was found that this motor pattern can be exhausted with repeated
stimulation. Spontaneous responses did not show the exhaustion phenomenon.
Results are discussed in the context of the sensory-motor aspects of male sexual
behaviour.
PMID- 10680763
TI - Activation of Broca's area by syntactic processing under conditions of concurrent
articulation.
AB - Regional cerebral blood flow (rCBF) was measured with positron emission
tomography (PET) when 11 subjects made plausibility judgments about written
sentences that varied in their syntactic complexity. While making their
judgments, subjects uttered the word "double" aloud at a rate of one utterance
per second to inhibit their ability to rehearse the sentences. Blood flow
increased in Broca's area when subjects made judgments about the more complex
sentences. This result replicates and extends previous findings that blood flow
increases in this region when subjects process complex syntax under no
interference conditions. The results of this experiment provide strong evidence
that the increase in blood flow seen in Broca's area in association with
processing syntactically complex structures is not due to subvocal rehearsal of
those structures, but rather results from processing syntactic forms themselves.
PMID- 10680764
TI - Human brain areas involved in the analysis of auditory movement.
AB - This work tests the hypothesis that a network of areas involving bilateral
premotor cortex and right parietal cortex subserves the analysis of sound
movement. The components of this network have been examined at the level of
individual subjects in a study where 720 fMRI scans were acquired per subject.
Additionally, the effect of movement direction was investigated by varying this
property systematically. Linear sound ramps that are perceived as movement toward
one side of the head or the other were used in an experiment in which the
principal contrast was between movement, and a stationary control stimulus made
up of identical component interaural phase and amplitude cues. In a group
analysis, the network of bifrontal and right parietal areas suggested by previous
work was confirmed. The frontal activation included both dorsal premotor activity
in the region of the frontal eye fields and discrete ventral premotor activation
in an area corresponding to primate areas for multimodal spatial analysis and
motor planning. The right parietal activation included both superior and inferior
parietal cortex. Analysis of the individual data showed a similar pattern of
activation in each subject, with the greatest variability within the right
parietal area. The pattern of activation did not vary when the direction of
movement was varied, suggesting that both directions of movement are represented
in the network we have demonstrated.
PMID- 10680765
TI - Mathematical/computational challenges in creating deformable and probabilistic
atlases of the human brain.
AB - Striking variations in brain structure, especially in the gyral patterns of the
human cortex, present fundamental challenges in human brain mapping.
Probabilistic brain atlases, which encode information on structural and
functional variability in large human populations, are powerful research tools
with broad applications. Knowledge-based imaging algorithms can also leverage
atlased information on anatomic variation. Applications include automated image
labeling, pathology detection in individuals or groups, and investigating how
regional anatomy is altered in disease, and with age, gender, handedness and
other clinical or genetic factors. In this report, we illustrate some of the
mathematical challenges involved in constructing population-based brain atlases.
A disease-specific atlas is constructed to represent the human brain in
Alzheimer's disease (AD). Specialized strategies are developed for population
based averaging of anatomy. Sets of high-dimensional elastic mappings, based on
the principles of continuum mechanics, reconfigure the anatomy of a large number
of subjects in an anatomic image database. These mappings generate a local
encoding of anatomic variability and are used to create a crisp anatomical image
template with highly resolved structures in their mean spatial location.
Specialized approaches are also developed to average cortical topography. Since
cortical patterns are altered in a variety of diseases, gyral pattern matching is
used to encode the magnitude and principal directions of local cortical
variation. In the resulting cortical templates, subtle features emerge. Regional
asymmetries appear that are not apparent in individual anatomies. Population
based maps of cortical variation reveal a mosaic of variability patterns that
segregate sharply according to functional specialization and cytoarchitectonic
boundaries.
PMID- 10680766
TI - Explicit and implicit neural mechanisms for processing of social information from
facial expressions: a functional magnetic resonance imaging study.
AB - The processing of changing nonverbal social signals such as facial expressions is
poorly understood, and it is unknown if different pathways are activated during
effortful (explicit), compared to implicit, processing of facial expressions.
Thus we used fMRI to determine which brain areas subserve processing of high
valence expressions and if distinct brain areas are activated when facial
expressions are processed explicitly or implicitly. Nine healthy volunteers were
scanned (1.5T GE Signa with ANMR, TE/TR 40/3,000 ms) during two similar
experiments in which blocks of mixed happy and angry facial expressions ("on"
condition) were alternated with blocks of neutral faces (control "off"
condition). Experiment 1 examined explicit processing of expressions by requiring
subjects to attend to, and judge, facial expression. Experiment 2 examined
implicit processing of expressions by requiring subjects to attend to, and judge,
facial gender, which was counterbalanced in both experimental conditions.
Processing of facial expressions significantly increased regional blood
oxygenation level-dependent (BOLD) activity in fusiform and middle temporal gyri,
hippocampus, amygdalohippocampal junction, and pulvinar nucleus. Explicit
processing evoked significantly more activity in temporal lobe cortex than
implicit processing, whereas implicit processing evoked significantly greater
activity in amygdala region. Mixed high-valence facial expressions are processed
within temporal lobe visual cortex, thalamus, and amygdalohippocampal complex.
Also, neural substrates for explicit and implicit processing of facial
expressions are dissociable: explicit processing activates temporal lobe cortex,
whereas implicit processing activates amygdala region. Our findings confirm a
neuroanatomical dissociation between conscious and unconscious processing of
emotional information.
PMID- 10680767
TI - Frequency dependence of the functional MRI response after electrical median nerve
stimulation.
AB - Localizing sensorimotor areas with high resolution functional MRI is of
considerable interest for a wide range of medical applications from the
preoperative planning of neurosurgical interventions to determining the course of
neuroplastic reorganisation after brain lesions. We examined the effect of the
stimulation frequency on the blood oxygen level dependent (BOLD) fMRI response
and on perfusion weighted fMRI using electrical median nerve stimulation at 5,
15, 40, and 100 Hz. BOLD fMRI was performed using a single shot gradient echo EPI
sequence to acquire 15 contiguous slices. For the qualitative flow sensitive
studies, a single slice inversion recovery prepared spin echo echoplanar sequence
(IR-SE EPI) was used. In the primary sensorimotor cortex, a linear increase of
the fMRI-BOLD response, affecting both the number of activated pixels and the
amplitude of the signal changes, was seen with increasing stimulation
frequencies. The qualitative in-flow sensitive studies, using the IR-SE EPI
sequence, indicate that the tissue perfusion also increases over the same range
of frequencies. This implicates that larger fMRI responses can be obtained if
electrical median nerve stimulation is performed at higher frequencies. The
results are compared with electrophysiological data, which show a decrease of the
early somatosensory evoked potentials at higher frequencies.
PMID- 10680768
TI - Search for compounds that inhibit the genotoxic and carcinogenic effects of
heterocyclic aromatic amines.
AB - Over the last 30 years approximately 160 reports have been published on dietary
compounds that protect from the mutagenic and carcinogenic effects of
heterocyclic aromatic amines (HAAs). In the first section of this review, the
current state of knowledge is briefly summarized. Based on the evaluation of the
available data, various protective mechanisms are described, and the use of
different methodologies for the detection of protective effects is critically
discussed. In most antimutagenicity studies (>70%) bacterial indicators
(predominantly Salmonella strain TA98) were used, and about 600 individual
compounds and complex mixtures have been identified that attenuate the effects of
HAAs. The most frequently used in vivo method to detect protective effects are
adduct measurements; anticarcinogenic dietary factors were identified by aberrant
crypt foci assays and liver foci tests with rats. The mechanisms of protection
include inactivation of HAAs and their metabolites by direct binding, inhibition
of enzymes involved in the metabolic activation of the amines, induction of
detoxifying enzymes, and interaction with DNA repair processes. The detection
spectrum of conventional in vitro mutagenicity assays with metabolically
incompetent indicator cells is limited. These procedures reflect only simple
mechanisms such as direct binding of the HAAs to pyrroles and fibers. It has been
shown that these compounds are also effective in rodents. More complex
mechanisms, namely, interactions with metabolic activation reactions are not
adequately represented in in vitro assays with exogenous enzyme homogenates, and
false-negative as well as false-positive results may be obtained. More
appropriate approaches for the detection of protective effects are recently
developed test systems with metabolically competent cells such as the human Hep
G2 line or primary hepatocytes. SCGE tests and DNA adduct measurements with
laboratory rodents enable the detection of antigenotoxic effects in different
organs, including those that are targets for tumor induction by the amines.
Medium term assays based on aberrant crypt foci in colon and liver foci tests
have been used to prove that certain compounds that prevented DNA damage by HAAs
also reduced their carcinogenic effects. These experiments are costly and time
consuming and, due to the weak induction capacity of the amines, only pronounced
anticarcinogenic effects can be detected. Over the years, a large bulk of data on
HAA protective compounds has accumulated, but only for a few (e.g., fibers,
pyrroles, constituents of teas, and lactic acid bacteria) is there sufficient
evidence to support the assumption that they are protective in humans as well.
PMID- 10680769
TI - Health effects of endocrine-disrupting chemicals on wildlife, with special
reference to the European situation.
AB - Many wildlife species may be exposed to biologically active concentrations of
endocrine-disrupting chemicals. There is strong evidence obtained from laboratory
studies showing the potential of several environmental chemicals to cause
endocrine disruption at environmentally realistic exposure levels. In wildlife
populations, associations have been reported between reproductive and
developmental effects and endocrine-disrupting chemicals. In the aquatic
environment, effects have been observed in mammals, birds, reptiles, fish, and
mollusks from Europe, North America, and other areas. The observed abnormalities
vary from subtle changes to permanent alterations, including disturbed sex
differentiation with feminized or masculinized sex organs, changed sexual
behavior, and altered immune function. For most reported effects in wildlife,
however, the evidence for a causal link with endocrine disruption is weak or
nonexisting. Crucial in establishing causal evidence for chemical-induced
wildlife effects appeared semifield or laboratory studies using the wildlife
species of concern. Impaired reproduction and development causally linked to
endocrine-disrupting chemicals are well documented in a number of species and
have resulted in local or regional population changes. These include:
Masculinization (imposex) in female marine snails by tributyltin, a biocide used
in antifouling paints, is probably the clearest case of endocrine disruption
caused by an environmental chemical. The dogwhelk is particularly sensitive, and
imposex has resulted in decline or extinction of local populations worldwide,
including coastal areas all over Europe and the open North Sea. DDE-induced egg
shell thinning in birds has caused severe population declines in a number of
raptor species in Europe and North America. Endocrine-disrupting chemicals have
adversely affected a variety of fish species. In the vicinity of certain sources
(e.g., effluents of water treatment plants) and in the most contaminated areas is
this exposure causally linked with the effects on reproductive organs that could
have implications for fish populations. However, there is also a more widespread
occurrence of endocrine disruption in fish in the U.K., where estrogenic effects
have been demonstrated in freshwater systems, in estuaries, and in coastal areas.
In mammals, the best evidence comes from the-field studies on Baltic gray and
ringed seals, and from the Dutch semifield studies on harbor seals, where both
reproduction and immune functions have been impaired by PCBs in the food chain.
Reproduction effects resulted in population declines, whereas impaired immune
function has likely contributed to the mass mortalities due to morbillivirus
infections. Distorted sex organ development and function in alligators has been
related to a major pesticide spill into a lake in Florida, U.S.A. The observed
estrogenic/antiandrogenic effects in this reptile have been causally linked in
experimental studies with alligator eggs to the DDT complex. Although most
observed effects currently reported concern heavily polluted areas, endocrine
disruption is a potential global problem. This is exemplified by the widespread
occurrence of imposex in marine snails and the recent findings of high levels of
persistent potential endocrine-disrupting chemicals in several marine mammalian
species inhabiting oceanic waters.
PMID- 10680770
TI - Changes of the thromboxane A2/prostacyclin balance in the urine of patients with
renal diseases analyzed by gas chromatography/selected ion monitoring.
AB - The thromboxane A2/prostacyclin (TX/PGI) ratios were measured in patients with
renal diseases to elucidate the relationship between the ratios and the
pathological changes of the diseases. Urinary stable metabolites of thromboxane
A2 and prostacyclin, 11-dehydro-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin
F1alpha, respectively, were converted to 1-methyl ester-propylamide-9,12,15-tris
dimethylisopropylsilyl ether derivative and 1-methyl ester-6-methoxime-9,12,15
tris-dimethylisopropylsilyl ether derivative, respectively, and applied to a gas
chromatography/selected ion monitoring. The TX/PGI ratios of 10 outpatients and 6
inpatients with chronic glomerulonephritis were higher than those of 13 healthy
volunteers. In an inpatient with systemic lupus erythematoides, the TX/PGI ratios
were gradually lowered to the normal level with the therapies. Furthermore, the
ratios seemed to change in advance of the changes of the levels of urinary
protein and hematuria. These observations suggested that the TX/PGI ratio was a
useful index to assess the pathological condition of renal diseases and the
effects of treatment.
PMID- 10680771
TI - Neonatal urinary prostanoid excretion.
AB - Urinary excretion of prostanoids prostaglandin E2 (PGE2), PGE-M (7alpha-hydroxy
5,11-diketo-2,3,4,5,20-penta-19-carboxyprostano ic acid), 6-keto-PGF1alpha, 2,3
dinor-6-keto-PGF1alpha, thromboxane B2 (TxB2) 2,3-dinor-TxB2 and 11-dehydro-TxB2
was determined by gas chromatography/mass spectrometry in preterm and term
infants to show that there is an age-dependent excretion rate of the above
prostanoids in infants this young. Group I included premature children with
normal postnatal development, Groups II and III included term children who were
admitted in the neonatal period for observation because of feeding problems but
who were subsequently found to be completely healthy. We present normal data of
three primary prostanoids and four prostanoid metabolites. In Group I, excretion
rates of 2,3-dinor-TxB2 were significantly lower than in Group II (P = 0.04) and
in Group III (P = 0.05). Furthermore, the excretion rate of 11-dehydro-TxB2 in
group I was significantly lower than in Group II (P = 0.05). We found no
significant age-dependent differences between the three groups in excretion rates
of PGE2, PGE-M, 6-keto-PGF1alpha, 2,3-dinor-6-keto-PGF1alpha, and TxB2.
PMID- 10680772
TI - Cyclooxygenases-1 and 2 couple to cytosolic but not group IIA phospholipase A2 in
COS-1 cells.
AB - Phospholipases A2 (PLA2) and cyclooxygenases (COX) are important enzymes
responsible for production of potent lipid mediators, including prostaglandins
(PG) and thromboxane A2. We investigated coupling between PLA2 and COX isoforms
by using transient transfection in COS-1 cells. Untransfected cells, incubated
with or without phorbol ester + the Ca2+ ionophore ionomycin, generated trivial
amounts of PGE2. In cells co-transfected with cytosolic PLA2 (cPLA2) and COX-1 or
COX-2, phorbol ester + ionomycin markedly stimulated PGE2 production. There was
no preferential coupling of cPLA2 to either of the COX isoforms. In contrast,
group IIA secretory PLA2 (sPLA2) co-transfected with COX-1 or COX-2 did not lead
to an increase in PGE2 production, despite high levels of sPLA2 enzymatic
activity. Transfection of cPLA2 did not affect basal free arachidonic acid (AA)
levels. Phorbol ester + ionomycin stimulated release of AA in cPLA2-transfected
COS-1 cells, but not in untransfected cells, whereas sPLA2 transfection (without
stimulation) led to high basal free AA. Thus, AA released by cPLA2 is accessible
to both COX isoforms for metabolism to PG, whereas AA released by sPLA2 is not
metabolized by COX.
PMID- 10680773
TI - Suppression of oxytocin-induced prostaglandin F2alpha release after intra-uterine
nordihydroguariaretic acid administration in ewes.
AB - Intrauterine administration of the 5-lipoxygenase inhibitor nordihydroguariaretic
acid (NDGA; 5 mg, bid) on Days 9-14 of the ovine estrous cycle (estrus = Day 0)
delayed luteolysis and extended the duration of the estrous cycle (20+/-1, SD,
vs. 16+/-1 days; P < 0.01). In control ewes, plasma concentrations of
13,14,dihydro-15-keto prostaglandin F2alpha increased significantly (P < 0.001)
following i.v. administration of oxytocin (10 i.u.) on Day 14; in the
nordihydroguariaretic acid-treated ewes, however, there was no such increase. In
addition, concentrations of endometrial oxytocin receptors were significantly
less (P < 0.01) in the nordihydroguariaretic acid-treated ewes (218+/-60 vs.
579+/-66 fmol/mg tissue). These results suggest that 5-lipoxygenase products of
arachidonate metabolism may be involved in the control of ovine luteal function.
PMID- 10680774
TI - Different actions of noradrenaline and nitric oxide on the output of
prostaglandins and progesterone in cultured bovine luteal cells.
AB - The effects of noradrenaline (NA) and nitric oxide (NO) on prostaglandins (PGs)
and progesterone (P4) secretion during the development of the bovine corpus
luteum (CL) were investigated. Bovine luteal cells of early and mid-cycle CL were
cultured for 20 to 24 h in medium containing 10% calf serum, washed, and treated
with NA or nitrergic agents for an additional 16 h in a serum-free medium. NA
(10(-5) M) stimulated P4 from early and mid-cycle CL by 238% and 154% (P < 0.01),
respectively. Moreover, although NA induced a twofold increase in PGE2 secretion
(P < 0.01) in both examined periods, the effect of NA on PGF2alpha secretion was
approximately 1.5 times higher (P < 0.05) in early than in mid-cycle CL. Two NO
synthase inhibitors, L-NAME and L-NOARG (both 10(-4) M), stimulated P4 secretion
only in mid-luteal cells (P < 0.01), although they did not affect the cells from
early CL. Although a NO donor, S-NAP (10(-4) M) inhibited P4 secretion from mid
cycle luteal cells (P < 0.05), it strongly stimulated PGE2 in both examined
phases (P < 0.001). On the other hand, the output of PGF2alpha was stimulated by
S-NAP only in the cells of the mid-cycle CL (P < 0.01). The overall results
suggest that adrenergic and nitrergic agents play opposite roles in the
regulation of bovine CL functions. Whereas NA may play a supporting role in
luteal development, NO may participate in the functional regression of the bovine
CL by inhibiting steroidogenesis.
PMID- 10680775
TI - No involvement of lipid mediators in a guinea pig model of ultrasonically
nebulized distilled water-induced bronchoconstriction.
AB - An inhalation of ultrasonically nebulized distilled water (UNDW) induces
bronchoconstriction only in asthmatics, but the mechanism underlying the response
is not fully understood. We have reported that bronchoconstriction occurs
immediately after UNDW is inhaled 20 min after an antigen challenge in guinea
pigs. Our aim was to examine the role of lipid mediators in this response.
Passively sensitized guinea pigs were anesthetized and artificially ventilated. A
sulfidopeptide leukotriene receptor antagonist, KCA-757, and platelet-activating
factor antagonists, Y-24180 and E6123, were administered i.v. 15 min after an
aerosolized antigen challenge, and UNDW was inhaled 5 min later. KCA-757, Y
24180, or E6123 did not, significantly alter the UNDW-induced
bronchoconstriction. Together with our previous data that thromboxane A2 receptor
antagonists did not influence the UNDW-induced bronchoconstriction, the present
results suggest that lipid mediators are not involved in the UNDW-induced
bronchoconstriction in our guinea pig model.
PMID- 10680776
TI - Fetal surfactant as a source of arachidonate in human amniotic fluid.
AB - The factors responsible for the onset of labor in women are not well understood
but it is clear that parturition is associated with increased production of
prostanoids and release of arachidonic acid by intrauterine tissues. Pulmonary
surfactant is secreted from the fetal lung into the amniotic fluid where its
concentration increases toward term. In this paper we have shown that the ability
of fetal surfactant to stimulate prostaglandin production by amnion cells is
greatly enhanced by pre-incubating surfactant with amniotic fluid. This is due to
the release of fatty acids, including arachidonate, from the lipids of fetal
surfactant by the sequential action of phospholipase C and diglyceride lipase.
Thus, in addition to providing the amnion with a source of arachidonate derived
from the intracellular transfer of arachidonate from surfactant
phosphatidylcholine to phosphatidylethanolamine and phosphatidylinositol in
amnion cells, fetal surfactant also contributes to the pool of free arachidonate
in amniotic fluid.
PMID- 10680777
TI - The influence of prostaglandins on leukocyte-endothelium interactions in rabbit
mesenteric venules.
AB - Contradictory results have been reported concerning the effects of prostaglandins
(PGs) on leukocyte-endothelium interactions. Therefore, we investigated the in
vivo effects of PGE1, PGE2, Iloprost (a stable PGI2-analogue), and also of a
combination of these PGs on leukocyte rolling and FMLP-induced leukocyte adhesion
in venules of rabbit mesentery. This preparation was used because of its low
level of vasoactivity, eliminating hemodynamic effects on leukocyte-endothelium
interactions. The mesentery was superfused with PGs or vehicle. After 30 min FMLP
was added to the PG-solution for 15 min, whereupon the tissue was superfused with
the PG-solution alone for another 30 min. Neither the PGs nor the cocktail
influenced leukocyte rolling. During FMLP administration leukocyte adhesion
increased and leukocyte rolling decreased; adhesion was highest in the presence
of PGE2. The FMLP-induced decrease in leukocyte rolling was similar in all
groups. After FMLP administration had been stopped the number of adherent cells
almost returned to baseline and the level of leukocyte rolling increased, the
baseline level being reached only in the presence of PGE2. In conclusion, these
findings indicate that the effects of PGs on leukocyte-endothelium interactions
are limited.
PMID- 10680779
TI - Seeking genes for MS: big risks for big gains.
PMID- 10680778
TI - Tissue prostanoids as biomarkers for chemoprevention of colorectal neoplasia:
correlation between prostanoid synthesis and clinical response in familial
adenomatous polyposis.
AB - Recent studies indicate that sulindac, a nonsteroidal anti-inflammatory drug
(NSAID), lowers mucosal prostanoid levels and regresses colorectal adenomas in
patients with familial adenomatous polyposis (FAP). To determine whether they are
biomarkers for sulindac-mediated chemoprevention of colorectal adenomas, levels
of 5 prostanoids [prostaglandin (PG) D2, PGE2, PGF2alpha, thromboxane B2, and 6
keto-PGF1alpha] in the normal-appearing rectal mucosa from 7 FAP patients with a
history of subtotal colectomy and ileorectal anastomosis and 4 FAP patients
without surgery, were measured in the absence or presence of exogenously added
arachidonic acid before the initiation and at the end of 3 months of sulindac
treatment. The addition of arachidonic acid resulted in a uniform increase in the
levels of all 5 prostanoids although this increase was selectively attenuated in
patients with ileorectal anastomosis who took sulindac. In the latter patients,
arachidonic acid also augmented the inhibition of prostanoid synthesis by
sulindac. In contrast, sulindac failed to attenuate the increase in prostanoid
levels resulting from arachidonic acid in patients without previous surgery.
Importantly, when measured in the presence of arachidonic acid, the reduction in
the levels of all 5 prostanoids due to sulindac was statistically correlated with
a reduction in the size and number of adenomas in the two groups of patients
combined. These results suggest that tissue prostanoids measured in the presence
of arachidonic acid may serve as sensitive and reliable biomarkers in monitoring
the clinical responsiveness of FAP patients undergoing chemoprevention for
colorectal neoplasia with NSAIDs.
PMID- 10680780
TI - Do changes in brain sodium channels cause central pain?
PMID- 10680781
TI - Hereditary recurrent focal neuropathies: clinical and molecular features.
AB - The authors review the molecular genetics and pathophysiology of hereditary
recurrent focal neuropathies: hereditary neuropathy with liability to pressure
palsies (HNPP) and hereditary neuralgic amyotrophy (HNA). Significant progress in
the understanding of HNPP and HNA has been achieved. HNPP and HNA are distinct
clinical and pathologic disease entities with autosomal dominant inheritance.
Molecular genetic studies have shown that HNPP and HNA are located on chromosome
17 but at distinct genetic loci (17p11.2 for HNPP, 17q25 for HNA). The 1.5
megabase deletion in 17p11.2 is the major cause of HNPP. This interstitial
deletion causes the complete loss of one allele of the peripheral myelin protein
22 (PMP22) gene. Interestingly, rare HNPP patients are found without the 1.5
megabase deletion. However, these patients have distinct mutations in the PMP22
gene resulting in altered expression of the PMP22 protein. Current molecular
genetic tests and clinical guidelines allow improved diagnosis, prognosis, and
genetic counseling for patients with HNPP. Such tests are not available for HNA,
because the disease-causing gene remains unknown. Molecular genetic advances in
HNPP and HNA, as well as the study of transgenic animal and cellular models, will
provide a more precise understanding of the disease mechanisms and will lead to
the development of effective therapeutic tools for patients with inherited and
sporadic recurrent peripheral neuropathies.
PMID- 10680782
TI - Glutathione S-transferase polymorphisms in MS: their relationship to disability.
AB - BACKGROUND: Oxidative stress has been implicated in inflammatory demyelination.
The glutathione S-transferase (GST) supergene family encodes isoenzymes that
appear to be critical in protection against oxidative stress. Certain GST loci
are polymorphic, demonstrating alleles that are null (GSTM1/GSTT1), encode low
activity variants (GSTP1), or are associated with variable inducibility (GSTM3).
OBJECTIVES: To investigate the association between clinical outcome in MS and
allelic variants of GSTM1, GSTM3, GSTT1, and GSTP1. METHODS: Four hundred
patients with clinically definite MS were studied. Disability was measured using
the Kurtzke Expanded Disability Status Scale (EDSS). Disability was graded as
mild (EDSS 0-4), moderate (4.5-5.5), or severe (EDSS 6-10). PCR-based genotyping
was performed using DNA extracted from lymphocytes. Significant associations
between GST genotypes and clinical outcome were corrected for gender, onset age,
and disease duration using logistic regression. RESULTS: We found that the GSTM3
AA genotype was associated with severe disability in patients with a disease
duration of more than 10 years (p = 0.027, n = 177, OR = 2.4, 95% CI = 1.1-5.0).
Homozygosity for both GSTM1*0 and GSTP1*Ile105 containing allele was associated
with severe disability in patients with a disease duration greater than 10 years
(p = 0.022, n = 179, OR = 5.0, 95% CI = 1.3-19.8). CONCLUSIONS: Our results
suggest that long-term prognosis in MS is influenced by a genetically determined
ability to remove the toxic products of oxidative stress.
PMID- 10680783
TI - Cortical cerebral metabolism correlates with MRI lesion load and cognitive
dysfunction in MS.
AB - OBJECTIVE: To study the association between the cortical cerebral metabolic rate
of glucose (CMRglc), MRI T2-weighted total lesion area (TLA), cognitive
dysfunction, and neurologic disability in MS. BACKGROUND: MRI lesion load is
widely used in the clinical evaluation of the MS patient but little is known
about the associated changes in cortical activation. METHODS: Twenty-three
patients with clinically definite MS underwent measurements of CMRglc, TLA, motor
evoked potentials (MEPs), and cognitive and neurologic disability. CMRglc was
calculated using PET and 18-F-deoxyglucose and compared with nine normal control
subjects. RESULTS: Reductions in CMRglc (p < 0.01) were found in the cortical
global and regional lobar measurements. Furthermore, regional CMRglc (rCMRglc)
was reduced in the dorsolateral prefrontal cortex, orbitofrontal cortex, caudate,
putamen, thalamus, and hippocampus. Global cortical CMRglc correlated with TLA
(Spearman rank correlation coefficient [SRCC] = -0.66, p = 0.001), and rCMRglc
correlated with regional lesion load in all cerebral lobes (p < or = 0.05).
Global cortical CMRglc and cognitive disability also correlated (SRCC = 0.58, p =
0.015), and stepwise regression analysis showed a significant association between
rCMRglc of the right thalamus and cognitive performance as well as TLA. There was
no correlation between CMRglc and neurologic disability (Expanded Disability
Status Scale) or MEP. CONCLUSION: Global and regional cortical CMRglc is reduced
significantly in MS patients compared with normal control subjects. Furthermore,
the CMRglc reductions correlate with TLA as well as with cognitive dysfunction,
which indicates that MRI white matter lesion burden has a deteriorating effect on
cortical cerebral neural function.
PMID- 10680784
TI - Intravenous lidocaine in central pain: a double-blind, placebo-controlled,
psychophysical study.
AB - OBJECTIVE: To investigate the effects of systemic administration of lidocaine on
different components of neuropathic central pains by quantitative sensory
testing. METHODS: The efficacy of systemic lidocaine (5 mg/kg IV over 30 minutes)
was evaluated in a double-blind, placebo-controlled, and cross-over fashion, on
both spontaneous ongoing pain and evoked pains (allodynia and hyperalgesia) in 16
patients with chronic poststroke (n = 6) or spinal cord injury (n = 10) related
pain. RESULTS: Lidocaine was significantly superior to the placebo (saline) in
reducing the intensity of spontaneous ongoing pain for up to 45 minutes after the
injection: 10 of 16 patients (62.5%) receiving lidocaine showed a significant
reduction in spontaneous pain, whereas only six patients showed this after the
placebo. Lidocaine also significantly reduced the intensity of brush-induced
allodynia and mechanical hyperalgesia, but was no better than the placebo against
thermal allodynia and hyperalgesia. In general, the side effects were moderate
and consisted mainly of lightheadedness (44%). CONCLUSIONS: Systemic lidocaine
can induce a significant and selective reduction of several components of pain
caused by CNS injuries. The observed preferential antihyperalgesic and
antiallodynic effects of this drug suggest a selective central action on the
mechanisms underlying these evoked pains.
PMID- 10680785
TI - Fear recognition deficits after focal brain damage: a cautionary note.
AB - OBJECTIVE: To test the hypothesis that fear recognition deficits in neurologic
patients reflect damage to an emotion-specific neural network. BACKGROUND:
Previous studies have suggested that the perception of fear in facial expressions
is mediated by a specialized neural system that includes the amygdala and certain
posterior right-hemisphere cortical regions. However, the neuropsychological
findings in patients with amygdala damage are inconclusive, and the contribution
of distinct cortical regions to fear perception has only been examined in one
study. METHODS: We studied the recognition of six basic facial expressions by
asking subjects to match these emotions with the appropriate verbal labels.
RESULTS: Both normal control subjects (n = 80) and patients with focal brain
damage (n = 63) performed significantly worse in recognizing fear than in
recognizing any other facial emotion, with errors consisting primarily of
mistaking fear for surprise. Although patients were impaired relative to control
subjects in recognizing fear, we could not obtain convincing evidence that left,
right, or bilateral lesions were associated with disproportionate impairments of
fear perception once we adjusted for differences in overall recognition
performance for the other five facial emotion categories. The proposed special
role of the amygdala and posterior right-hemisphere cortical regions in fear
perception was also not supported. CONCLUSIONS: Fear recognition deficits in
neurologic patients may be attributable to task difficulty factors rather than
damage to putative neural systems dedicated to fear perception.
PMID- 10680786
TI - Memory and MRI-based hippocampal volumes in aging and AD.
AB - OBJECTIVE: To demonstrate structural-functional relationships between MRI-based
volumetric measurements of medial temporal lobe structures and cognitive
function. BACKGROUND: Previous work has documented the ability of MRI-based
measurements of the hippocampus to discriminate between age-matched control
subjects and patients with very mild AD. Relatively less is known about the
correlation between medial temporal lobe structures and cognitive functions.
METHOD: We evaluated structural-functional relationships among the hippocampal
formation, parahippocampal gyrus, and amygdala, and measures of memory, language,
and general cognitive performance in 220 probable AD patients and normal control
subjects. Standardized instruments of memory and general cognitive function were
used to assess subjects enrolled in a longitudinal study of aging and dementia.
RESULTS: The volume of the hippocampal formation predicted performance on most
acquisition and recall measures across the spectrum of normal aging and AD. If
the groups were segregated, most of the expected associations between medial
temporal lobe structures and memory measures were observed in the AD patients.
CONCLUSION: MRI-based hippocampal volumetry accurately depicts the structural
functional relationships between memory loss and hippocampal damage across the
spectrum from normal aging to dementia.
PMID- 10680787
TI - A randomized controlled trial of prednisone in Alzheimer's disease. Alzheimer's
Disease Cooperative Study.
AB - BACKGROUND: Laboratory and epidemiologic studies suggest that anti
inflammatory/immunosuppressive therapy may be useful in the treatment of AD. In
preliminary studies, a regimen of low to moderate dose prednisone was found to
suppress peripheral inflammatory markers without adverse effects in subjects with
AD. METHODS: We conducted a randomized, placebo-controlled multicenter trial to
determine whether prednisone treatment slowed the rate of cognitive decline in
AD. The active treatment regimen consisted of an initial dose of 20 mg of
prednisone daily for 4 weeks tapered to a maintenance dose of 10 mg daily for 1
year, followed by gradual withdrawal during an additional 16 weeks. The primary
outcome measure was the 1-year change in the cognitive subscale of the AD
Assessment Scale. RESULTS: A total of 138 subjects were randomized to the drug
and placebo groups. There was no difference in cognitive decline between the
prednisone and placebo treatment groups in the primary intent-to-treat analysis,
or in a secondary analysis considering completers only. Subjects treated with
prednisone showed behavioral decline compared with those in the placebo group.
CONCLUSION: A low-dose regimen of prednisone is not useful in the treatment of
AD.
PMID- 10680788
TI - APOE and AD concordance in twin pairs as predictors of AD in first-degree
relatives.
AB - OBJECTIVE: To examine the independent effects of the APOE genotype (APOE) and
concordance for AD in twin pairs on the occurrence of AD in first-degree
relatives. BACKGROUND: Studies of twins have been undertaken to investigate the
influence of genes in a variety of conditions, including AD. A previous study,
performed before reports linking APOE to AD, demonstrated an increase in AD among
first-degree relatives of twins concordant for AD compared with relatives of
discordant twins. METHODS: In a sample of 94 twin pairs the authors examined the
association between concordance for AD within the twin pair and family history of
AD among first-degree relatives of twins. They then examined the extent to which
the presence of the APOE epsilon4 allele in the twin pair explains the
association between concordance for AD within the twin pair and family history of
AD. RESULTS: Concordance among twins was associated with increased risk of AD
among relatives (logrank test, chi2 = 12.558; p = 0.0004), and the presence of at
least one APOE epsilon4 allele in each member of the twin pair is also associated
with increased risk of AD among family members (logrank test, chi2 = 7.712; p =
0.0055). CONCLUSIONS: APOE genotype explains much but not all of the association
between concordance among twins and increased familial risk of AD.
PMID- 10680789
TI - Associations between circulating sex steroid hormones and cognition in normal
elderly women.
AB - OBJECTIVE: To provide exploratory analyses of associations between levels of
several sex hormones and cognitive performance in elderly women. BACKGROUND: Sex
steroid hormones are implicated in the cognitive processes of the adult brain.
Comparing cognitive performance across or between conditions associated with
different hormone levels, such as phases of the menstrual cycle, surgical
menopause, and estrogen replacement therapy suggests conditions with higher
levels of estrogen are associated with better verbal memory and possibly worse
visuospatial ability. METHOD: The authors measured circulating sex hormone levels
in 39 highly educated, nondemented, predominantly white elderly women. Levels
were correlated with neuropsychological performance, controlling for age,
education, frequency of prior testing, use of estrogen replacement, and
depression. RESULTS: High estradiol levels were associated with better delayed
verbal memory and retrieval efficiency, whereas low levels were associated with
better immediate and delayed visual memory. Levels of testosterone were related
positively to verbal fluency. Levels of progesterone and androstenedione were
unrelated to cognitive performance. CONCLUSIONS: Both estrogen and testosterone
showed associations with cognitive performance. Estrogen may enhance, and
depress, specific cognitive skills.
PMID- 10680790
TI - A randomized trial of 3,4-diaminopyridine in Lambert-Eaton myasthenic syndrome.
AB - OBJECTIVES: The authors report the results of a prospective, placebo-controlled,
randomized study to evaluate the effectiveness of 3,4-diaminopyridine (DAP) in
patients with Lambert-Eaton myasthenic syndrome (LEMS) and to determine the acute
and long-term side effects of DAP. METHODS: Twenty-six patients with LEMS
completed a two-arm parallel treatment protocol in which DAP, 20 mg three times
daily, or placebo was given blindly for 6 days, and a quantitative examination of
muscle strength (the quantitative myasthenia gravis [QMG] score) was used as the
primary measure of efficacy. After the blinded study, patients were given open
label DAP and monitored for side effects as long as there was symptomatic
improvement. RESULTS: Twelve patients took DAP, and 14 took placebo. There was no
difference in the age of LEMS onset, gender distribution, incidence of lung
cancer, or baseline muscle strength between the patients who were randomly
assigned to receive placebo and those randomly assigned to DAP. Statistical
analysis using the Wilcoxon's rank sum test demonstrated that patients who
received DAP had a significantly greater improvement in the QMG score and in the
summated amplitude of compound muscle action potentials recorded from three
sentinel limb muscles. All but one LEMS patient had significant symptomatic
improvement from subsequent open-label DAP. Side effects of DAP were negligible,
consisting of perioral and digital paresthesia. Laboratory measurements
demonstrated no evidence of toxicity affecting liver, renal, hematologic,
endocrinologic, encephalographic, or electrocardiologic function acutely or after
6 months of open-label DAP. CONCLUSIONS: This study corroborates previous studies
and many years of clinical experience showing that DAP is an effective and safe
treatment for LEMS.
PMID- 10680791
TI - GCG genetic expansions in Italian patients with oculopharyngeal muscular
dystrophy.
AB - OBJECTIVE: To screen Italian patients with oculopharyngeal muscular dystrophy
(OPMD) for GCG repeat expansions in the Poly(A) binding-protein 2 (PABP2) gene.
BACKGROUND: Oculopharyngeal muscular dystrophy is an adult-onset autosomal
dominant muscle disease linked to 14q11 pathologically characterized by unique
8.5 nm intranuclear filaments in skeletal muscle fibers. Short expansions of a
(GCG)6 repeat located in exon 1 of the newly isolated PABP2 gene have been
demonstrated in a large number of OPMD families. METHODS: We studied 18 patients
diagnosed with OPMD. A muscle biopsy was performed in 16 patients. Screening for
the pathologic expansion was performed on a PCR amplified DNA fragment
encompassing the GCG repeat. RESULTS: Heterozygous (GCG)-repeat expansions were
detected in 13 patients in association with (GCG)6 normal allele or (GCG)7
polymorphic allele. All the patients whose muscle biopsy showed typical 8.5 nm
intranuclear filaments had a mutated PABP2 allele. Five patients with no
intranuclear filaments were homozygous for the normal (GCG)6 allele. The
pathologic expansion appeared to be stable with no variation among family members
and between different tissues as blood and skeletal muscle in the same
individual. CONCLUSIONS: These data 1) further confirm PABP2 gene analysis as a
valuable tool in OPMD diagnosis; 2) indicate that PABP2 gene mutations are always
present among Italian patients with morphologically proven OPMD, suggesting
genetic homogeneity of the disease; and 3) strengthen the putative role of
mutated PABP2 protein in filamentous inclusions accumulation.
PMID- 10680792
TI - Distal acquired demyelinating symmetric neuropathy.
AB - OBJECTIVE: To characterize an acquired, symmetric, demyelinating neuropathic
variant with distal sensory or sensorimotor features. BACKGROUND: Classic chronic
inflammatory demyelinating polyradiculoneuropathy (CIDP) patients have prominent
proximal and distal weakness. However, chronic demyelinating neuropathies may
present with different phenotypes. An approach that distinguishes these disorders
primarily according to the pattern of weakness may be useful to the clinician.
METHODS: A total of 53 patients with acquired symmetric demyelinating
polyneuropathies were classified primarily according to the pattern of the
neuropathy and secondarily according to the presence and type of monoclonal
protein (M-protein) in this retrospective review. The authors distinguished
between patients with distal sensory or sensorimotor involvement, designated as
distal acquired demyelinating symmetric (DADS) neuropathy, from those with
proximal and distal weakness, who were designated as CIDP. RESULTS: M-proteins
were present in 22% of patients with CIDP. There were no features that
distinguished clearly between CIDP patients with or without an M-protein, and
nearly all of these patients responded to immunomodulating therapy. In contrast,
nearly two-thirds of the patients with DADS neuropathy had immunoglobulin M (IgM)
kappa monoclonal gammopathies, and this specific combination predicted a poor
response to immunomodulating therapy. Antimyelin-associated glycoprotein (anti
MAG) antibodies were present in 67% of these patients. CONCLUSION: Distinguishing
acquired demyelinating neuropathies by phenotype can often predict the presence
of IgM kappa M-proteins, anti-MAG antibodies, and responses to immunomodulating
therapy.
PMID- 10680793
TI - Mild forms of Guillain-Barre syndrome in an epidemiologic survey in The
Netherlands.
AB - OBJECTIVE: Assessment of incidence rates of Guillain-Barre syndrome (GBS) in the
Netherlands over a 10-year period; investigation of a relationship between
possible seasonality in GBS and the occurrence of preceding infections; and
determination of distinctive characteristics in patients with GBS who are only
mildly affected (able to walk unaided at nadir). METHOD: Records of patients with
GBS admitted between 1987 and 1996 from all 45 hospitals in the southwest
Netherlands were evaluated, covering a population of 4.2 million inhabitants.
RESULTS: A total of 476 patients met National Institute for Neurological and
Communicative Disorders and Stroke criteria for GBS. This resulted in a crude
incidence rate (IR) of 1.18/100,000 inhabitants. This IR increased linearly with
age (p < 0.001). Men were more frequently affected than women (p < 0.001). No
seasonal preponderance for GBS, nor for any of the preceding infections, was
found. Patients under 50 years of age (p < 0.001) and men (p = 0.01) were more
frequently found in the mildly affected group. In both groups a preceding
infection was reported in 70% of the cases. In the severely affected group,
serologic evidence for infection with Campylobacter jejuni, cytomegalovirus,
Epstein-Barr virus, or Mycoplasma pneumoniae was found more frequently than in
the mildly affected group (41% versus 16%, p = 0.001). CONCLUSIONS: Overall IR in
the Netherlands are similar to those found in other studies. The incidence
increases linearly with age and men are more frequently affected than women.
Distinctive characteristics for mildly and severely affected patients were found
regarding age, sex, and preceding infections. This suggests that other infectious
agents or host factors may be involved in mild forms of GBS.
PMID- 10680794
TI - Driving in adults with refractory localization-related epilepsy. Multi-Center
Study of Epilepsy Surgery.
AB - OBJECTIVE: To examine the frequency of driving an automobile and characteristics
associated with driving in individuals with refractory localization-related
epilepsy. BACKGROUND: Driving is generally restricted and monitored in people
with epilepsy. Little is known about the frequency of driving and subsequent
accidents specifically in individuals with uncontrolled epilepsy. METHODS: In an
ongoing, prospective, multicenter study of resective epilepsy surgery,
individuals were interviewed when they presented for surgical evaluation.
Analyses were conducted using chi-square, t-tests, and multiple logistic
regression. RESULTS: Of 367 eligible participants, 115 (31.3%) had driven in the
last year, most on at least a weekly basis. In a multivariable analysis, factors
associated with an increased likelihood of driving were having a current license
(OR = 10.71, p < 0.001) and ever having had a license (OR = 3.86, p = 0.003).
Younger individuals were also more likely to drive. Lower levels of driving were
found in women (OR = 0.31, p < 0.001), individuals who were self-described as
disabled (OR = 0.20, p < 0.001), and those who were employed full-time (OR =
0.43, p = 0.03) or part-time (OR = 0.15, p = 0.005). At some point in the past,
144 individuals experienced one or more seizures while driving, and 98
experienced at least one accident because of a seizure. Of those who had
accidents, 94% reported property damage, 32% had an injury, and 20% caused injury
to others. CONCLUSION: Despite restrictions, almost one third of individuals with
refractory epilepsy drive. Understanding why they do may help identify means of
modifying this behavior or identifying services that, if provided, would help
people with uncontrolled epilepsy forego driving.
PMID- 10680795
TI - Seizure outcome after temporal lobectomy for temporal lobe epilepsy: a Kaplan
Meier survival analysis.
AB - OBJECTIVE: To determine seizure outcome and its predictors in patients with
medically refractory temporal lobe epilepsy (TLE) after temporal lobectomy (TL).
BACKGROUND: TL is the most common surgical procedure performed in adolescents and
adults for the treatment of medically refractory TLE. Seizure outcome has been
reported extensively during the first few postoperative years, but little is
known beyond that time. METHODS: The authors analyzed seizure outcome in 79
patients who underwent TL for epilepsy at the Duke University Medical Center from
1962 through 1984. Patients with less than 2 years of follow-up and degenerative
disorders were excluded. Predictors of seizure outcome were analyzed using Kaplan
Meier survival analyses. RESULTS: The mean follow-up was 14 years (range, 2.1 to
33.6 years). Using Engel's classification, 65% of patients were class I, 15% were
class II, 11% were class III, and 9% were class IV. At least one postoperative
seizure occurred in 55% of subjects. The majority of recurrences (86%) took place
within 2 years of surgery. Later recurrences tended not to lead to medical
intractability. Higher monthly preoperative seizure frequency was associated with
poor seizure outcome. A seizure-free state at 2 years was found to be a better
predictor of long-term outcome than the 6-, 12-, and 18-month landmarks.
CONCLUSIONS: TL provides sustained, long-term benefit in patients with medically
refractory TLE. Seizure-free status at 2 years from the time of surgery is
predictive of long-term remission.
PMID- 10680796
TI - An EEG should not be obtained routinely after first unprovoked seizure in
childhood.
AB - OBJECTIVE: To quantify and analyze the value of expected information from an EEG
after first unprovoked seizure in childhood. BACKGROUND: An EEG is often
recommended as part of the standard diagnostic evaluation after first seizure.
METHODS: A MEDLINE search from 1980 to 1998 was performed. From eligible studies,
data on EEG results and seizure recurrence risk in children were abstracted, and
sensitivity, specificity, and positive and negative predictive values of EEG in
predicting recurrence were calculated. Linear information theory was used to
quantify and compare the expected information from the EEG in all studies.
Standard test-treat decision analysis with a treatment threshold at 80%
recurrence risk was used to determine the range of pretest recurrence
probabilities over which testing affects treatment decisions. RESULTS: Four
studies involving 831 children were eligible for analysis. At best, the EEG had a
sensitivity of 61%, a specificity of 71%, and an expected information of 0.16 out
of a possible 0.50. The pretest probability of recurrence was less than the lower
limit of the range for rational testing in all studies. CONCLUSIONS: In this
analysis, the quantity of expected information from the EEG was too low to affect
treatment recommendations in most patients. EEG should be ordered selectively,
not routinely, after first unprovoked seizure in childhood.
PMID- 10680797
TI - Predictors of outcome in pediatric epilepsy surgery.
AB - OBJECTIVE: To determine the correlation between pre- and perioperative variables
on the outcome of children undergoing focal resections for medically intractable
partial epilepsy. METHODS: Retrospective analysis of pre- and perioperative
variables in a cohort of 75 patients younger than 12 years of age who underwent
excisional surgery and had at least 1 year of follow-up. Outcome, measured by
postoperative seizure frequency, was analyzed as a function of age at seizure
onset, duration of epilepsy, presence of cognitive impairment, lobe of seizure
origin, presence of a lesion, histopathology, and completeness of resection.
Completeness of resection was defined on the basis of excising both the entire
structural lesion if present and the region revealing prominent interictal and
ictal abnormalities on intracranial EEG. RESULTS: Seventy-seven percent of
patients had good outcomes (class 1 or 2), and 59% were seizure-free. Lesional
status, site of resection, and pathologic diagnoses were not significant
predictors of outcome except for in multilobar resection, for which overall
outcome was relatively poor (44% class 3 or 4; 22% seizure-free). Completeness of
resection was the only significant predictor of good outcome (p < 0.001), with
92% of patients who underwent complete resection of the epileptogenic zone
achieving good outcome compared with 50% of patients who had incomplete
resections. CONCLUSION: In this series of pediatric patients, complete resection
of the lesion and the electrographically abnormal region was the main determinant
of outcome after focal resections. Except for multilobar resections, other
factors examined in this study did not significantly influence postoperative
seizure prognosis and should not influence candidate selection for the surgical
process.
PMID- 10680798
TI - Reduction of corpus callosum growth after severe traumatic brain injury in
children.
AB - OBJECTIVE: To study effects of closed head injury (CHI) severity on development
of corpus callosum (CC) in children, using MRI. BACKGROUND: Vulnerability of CC
to diffuse axonal injury has been shown in adults and children by neuropathologic
and MRI studies. Given continued development of CC through the second decade,
serial MRI could characterize effects of CHI on CC growth in children. METHOD:
MRI performed at 3 and 36 months after severe (mean age = 10.3 years, n = 25) and
mild to moderate (mean age = 9.7 years, n = 28) CHI. Mild to moderate and severe
CHI groups did not differ in demographic features. Morphometry of T1-weighted
midsagittal CC by two operators with satisfactory interrater reliability yielded
uncorrected and corrected CC volume. RESULTS: An interaction of occasion with CHI
severity was present as CC area decreased from 3 to 36 months in severely injured
children and increased in the mild to moderate CHI group. Uncorrected CC area was
correlated with acute CHI severity and functional outcome at 36 months
postinjury. CONCLUSIONS: Morphometric measurement of CC area provides a useful
index of diffuse injury, which is related to functional outcome of CHI in
children.
PMID- 10680799
TI - Hypersomnia after head-neck trauma: a medicolegal dilemma.
AB - OBJECTIVES: To evaluate the severity of daytime sleepiness in patients with a
history of head trauma who complain of daytime somnolence, to investigate
polygraphic abnormalities during nocturnal sleep, and to determine whether
daytime sleepiness was the cause or consequence of the head trauma. METHODS: The
authors performed a systematic evaluation of 184 patients comprised of clinical
interviews, sleep disorders questionnaires, sleepiness and depression scales,
medical and neurologic evaluations, sleep logs with actigraphy, nocturnal
polysomnography, and the Multiple Sleep Latency Test (MSLT). Assessments of
sleepiness before the accident were based on bed partner interviews, coworker and
employer reports, health reports, driving records, and employment history that
included absenteeism. RESULTS: Post-traumatic complaint of somnolence was
associated with variable degrees of impaired daytime functioning in more than 98%
of patients. Patients who were in a coma for 24 hours, who had a head fracture,
or who had immediate neurosurgical interventions were likely to have scores > 16
points on the Epworth Sleepiness Scale (ESS) and < or = 5 minutes on the MSLT.
Pain at night was an important factor in nocturnal sleep disruption and daytime
sleepiness. Sleep-disordered breathing was a common finding and was the only
finding in whiplash patients with daytime sleepiness. Extensive evaluation of
pretrauma behavior supported the conclusion that the onset of symptomatic sleep
disordered breathing was associated with the trauma. The patients who showed a
"compulsive presleep behavior" were severely impaired in performing their daily
activities. CONCLUSIONS: A systematic approach is required when dealing with
patients complaining of hypersomnia following a head-neck trauma.
PMID- 10680800
TI - Risk factors and outcome of patients with carotid artery stenosis presenting with
lacunar stroke. North American Symptomatic Carotid Endarterectomy Trial Group.
AB - OBJECTIVE: To examine the relationship between carotid artery stenosis, other
risk factors, and lacunar stroke. BACKGROUND: Carotid artery stenosis in patients
presenting with lacune stroke may be coincidental or causal. The distinction by
risk factor profile is uncertain. The risk and cause of subsequent stroke, and
benefit of carotid endarterectomy (CE) is unknown. METHODS: Stroke in patients
entering the North American Symptomatic Carotid Endarterectomy Trial were
classified as nonlacunar, possible lacune (symptoms without CT lacunae), or
probable lacune (symptoms with CT lacunae). RESULTS: Of 1,158 patients with
hemispheric stroke, 493 had features of lacunar stroke (283 possible and 210
probable). Lacunar stroke presented more commonly in patients with milder (<50%)
degrees of internal carotid artery (ICA) stenosis (p = 0.003). History of
diabetes and hyperlipidemia, not hypertension, were associated independently even
after accounting for the degree of stenosis. Medically treated patients
presenting with nonlacunar stroke had a low risk of subsequent lacunar events of
2.9% at 3 years in comparison with 9.2% for probable lacunar presentation (p =
0.03). For patients with 50 to 99% ICA stenosis, the relative risk reductions
(RRRs) in stroke from CE were 35% when the presenting stroke was probable lacunar
versus 61% when the stroke was nonlacunar. Patients presenting with a possible
lacunar stroke had a 53% RRR. CONCLUSIONS: History of diabetes and hyperlipidemia
were more important than arterial hypertension as risk factors for patients with
lacunar stroke. Patients presenting with lacunar stroke more often had milder ICA
stenosis. Although CE reduced the risk of stroke in all patients with 50 to 99%
ICA stenosis, lesser benefits were observed in patients presenting with lacunar
stroke.
PMID- 10680801
TI - rtPA intravenous thrombolysis in anterior choroidal artery territory stroke.
AB - OBJECTIVE: To study the possible specific response to recombinant tissue
plasminogen activator (rtPA) thrombolysis of anterior choroidal artery (AChA)
stroke. BACKGROUND: Outcome and response after rtPA thrombolysis are possibly
better in small-vessel infarcts, but a specific study of AChA stroke has not yet
been performed. METHODS: The authors proposed an open trial of IV rtPA within 7
hours in patients age 20 and 81 years with all types of internal carotid artery
territory stroke if the baseline Scandinavian Stroke Scale (SSS) score was less
than 48. A dose of rtPA 0.8 mg/kg was infused over 90 minutes. Of 114 consecutive
patients, 9 patients (7.9%) exhibited hypodensity in the AChA territory on day 1
brain CT. RESULTS: Seven of nine patients with AChA infarct had a primary early
recovery within 6 hours after the initiation of rtPA infusion. In addition,
recovery was complete in five patients and partial in two patients. No
intracerebral hematoma was observed. Three patients had a "reinfarct syndrome" at
12, 25, and 48 hours respectively. However, in the two latter patients treated
with IV heparin, the deficit disappeared again with the increase of heparin dose
in one patient and disappeared spontaneously in the other patient. The overall
outcome at day 90 was six total recoveries in nine patients (66%). Patients with
a final good outcome had a slight "unstructured" hypodensity in the AChA
territory on day 1 brain CT, whereas patients with a bad outcome had the classic
"structured" hypodensity of AChA territory stroke. CONCLUSION: These data support
a specific quick response of AChA territory stroke to IV rtPA thrombolysis,
probably due to the small size of the artery and of the "clot." The high
frequency of the reinfarct syndrome is a clinical fact that is difficult to
explain. Efficient heparin treatment after 24 hours may control the reinfarct
syndrome in some patients.
PMID- 10680802
TI - Multiple acute stroke syndrome: marker of embolic disease?
AB - OBJECTIVE: To determine the frequency and etiologic significance of multiple
acute ischemic lesions in stroke. BACKGROUND: Although patients may have more
than one stroke during the course of their lives, acute ischemic stroke is
usually thought of as a single event. Using diffusion-weighted imaging (DWI), an
MRI technique that detects ischemic injury within minutes after onset, we have
often observed multiple acute ischemic lesions. METHODS: The MRI scans of 59
consecutively studied patients were reviewed to determine the frequency and
etiologic significance of multiple acute ischemic lesions on DWI. RESULTS:
Multiple acute ischemic lesions were present in 10 (17%) of 59 patients. The
lesions usually occurred within one major circulation (anterior or posterior),
but in two patients (3%), lesions occurred in both cerebral hemispheres or in the
anterior and the posterior circulations. The lesions often were small and
resulted from presumed multiple emboli or the break-up of an embolus. Two
patients had internal carotid artery occlusive disease and four had a cardiac or
aortic source. In the other four patients the source was not determined. Lesions
larger than 1 cm in diameter progressed to infarction, but some smaller lesions
were not seen on follow-up T2-weighted imaging. CONCLUSIONS: Multiple acute
stroke lesions on DWI are common and could be caused by multiple emboli or the
breakup of an embolus. In some cases it might become possible to make early
inferences concerning the stroke mechanism that could be of use for immediately
directing the clinical work-up and treatment of the patient.
PMID- 10680803
TI - Effectiveness of t-PA in acute ischemic stroke: outcome relates to
appropriateness.
AB - OBJECTIVE: To examine whether the demonstrated efficacy of tissue-type
plasminogen activator (t-PA) for acute ischemic stroke can be effective in a
community setting. METHODS: Sixty-eight consecutive patients with acute ischemic
stroke treated with IV t-PA within 3 hours of symptom onset by attending general
neurologists in a busy teaching hospital. Outcome measures at 3 months were the
National Institute of Health Stroke Scale (NIHSS), functional outcome
(independence [modified Rankin score 0-2], dependence [modified Rankin score 3
5], and death), and symptomatic hemorrhage. Appropriately treated patients were
defined by adherence to the National Institute of Neurological Disorders and
Stroke (NINDS) guidelines. Effectiveness is expressed as the absolute risk
reduction in which the baseline risk is assumed to be similar to that of the
NINDS control group. RESULTS: Of 68 consecutively treated patients (with a mean
baseline NIHSS score of 15 +/- 6), 26 (38%) made a full recovery and 39 (57%)
made an independent recovery. The 11 patients who violated protocol had a lower
probability of independence (p < 0.02) and full neurologic recovery (p < 0.02)
and a higher probability of symptomatic hemorrhage (p < 0.05) and death (p <
0.01) compared with those of 57 patients treated according to NINDS guidelines.
CONCLUSIONS: The use of t-PA for stroke in this community is effective with a
number needed to treat of six. The risk of symptomatic hemorrhage is similar to
that noted in randomized trials. Treating patients who violate protocol results
in excess risk with no observable benefit.
PMID- 10680804
TI - Identification of lacunar infarcts before thrombolysis in the ECASS I study.
AB - BACKGROUND: The identification of lacunar infarcts before thrombolysis would make
it possible either to exclude them from treatment or to show that they also may
benefit from it. OBJECTIVE: To determine whether clinical presentation or early
CT findings of patients enrolled in the first European Cooperative Acute Stroke
Study (ECASS I) trial would identify lacunar infarcts before treatment. METHODS:
Predictive values, sensitivity, specificity, and accuracy of clinical
presentation as pure motor hemiparesis (PMH) or sensorimotor stroke (SMS)
syndromes and of baseline CT findings in predicting lacunar infarcts were
calculated in the ECASS I patients. RESULTS: Of 514 patients, 44 placebo (17%)
and 44 recombinant tissue plasminogen activator (rt-PA) (18%) patients had
PMH/SMS involving at least two of three areas. Thirty-one placebo (12%) and 32 rt
PA (13%) patients had PMH/SMS involving three areas. The 7-day CT was compatible
with a lacunar infarct in 32 placebo (12%) and 44 rt-PA (18%) patients. PMH/SMS
involving at least two areas had a positive predictive value of 30% both in
placebo and rt-PA patients, whereas positive predictive values of the involvement
of three areas were 23% and 31%. Those of absence of early CT signs were 21% and
30%, and those of leukoaraiosis or previous lacunar infarcts were 21% and 23%.
Positive predictive values of PMH/SMS involving at least two areas combined with
absence of early CT signs were 36% in placebo and 33% in t-PA patients, and those
of PMH/SMS plus leukoaraiosis or previous lacunes were 28% and 7%, respectively.
CONCLUSIONS: In the ECASS I trial, lacunar infarcts were not recognizable on
clinical grounds, and early CT findings, alone or in combination with the
clinical picture, added poorly to the differential diagnosis.
PMID- 10680805
TI - Temporal evolution of ischemic injury evaluated with diffusion-, perfusion-, and
T2-weighted MRI.
AB - OBJECTIVE: Ischemic lesions seen on diffusion-weighted imaging (DWI) are
reversible if reperfusion is performed within minutes after the onset of
ischemia. This study was designed to determine whether acute reversibility of DWI
abnormalities is transient following brief temporary focal brain ischemia and to
characterize the temporal evolution of in vivo ischemic lesions. METHODS: Eight
rats were subjected to 30 minutes of temporary middle cerebral artery occlusion
and underwent diffusion-, perfusion-, and T2-weighted MRI during occlusion;
immediately after reperfusion; 30, 60, and 90 minutes after reperfusion; and 12,
24, 48, and 72 hours after reperfusion. Average apparent diffusion coefficient
(ADCav) values and the cerebral blood flow index (CBFi) ratio were calculated in
both the lateral caudoputamen and overlying cortex at each time point. The size
of the in vivo ischemic abnormalities was calculated from the ADCav and the T2
maps. Postmortem triphenyltetrazolium chloride (TTC) staining was used to verify
ischemic injury. RESULTS: Both the CBFi ratio and ADCav values declined
significantly in the two regions during occlusion. The CBFi ratio recovered
immediately after reperfusion and remained unchanged over 72 hours. However,
ADCav values returned to normal at 60 to 90 minutes and secondarily decreased at
12 hours after reperfusion as compared with those in the contralateral
hemisphere. The extent of the in vivo ischemic lesions maximized at 48 hours and
was highly correlated with TTC-derived lesion size. CONCLUSIONS: Acute recovery
of initial ADCav-defined lesions after reperfusion is transient, and secondary
ADCav-defined lesions develop in a slow and delayed fashion.
PMID- 10680806
TI - Differentiation of atypical parkinsonian syndromes with routine MRI.
AB - OBJECTIVE: To evaluate the use of routine MRI in differentiating between patients
with progressive supranuclear palsy (PSP), multiple system atrophy (MSA),
corticobasal degeneration (CBD) and control subjects. METHODS: Two
neuroradiologists rated blindly and independently axial T2-weighted and proton
density MR images of 54 patients with MSA, 35 patients with PSP, 5 patients with
CBD, and 44 control subjects. RESULTS: More than 70% of patients with PSP and
more than 80% of patients with cerebellar predominant MSA could be classified
correctly with 0.5-T or 1.5-T scans, and no patient in these groups was
misclassified. In the remaining patients an unequivocal differentiation could not
be made. However, only approximately 50% of patients with parkinsonism
predominant MSA could be classified correctly, and 19% of them (all of whom had
had 0.5-T scans) were misclassified. CONCLUSIONS: Characteristic findings on
routine MRI, either 1.5 T or 0.5 T, can contribute to the identification of MSA
and PSP. However, in a minority of patients no unequivocal diagnosis can be made
using MRI findings alone.
PMID- 10680807
TI - Mitochondrial DNA mutations in complex I and tRNA genes in Parkinson's disease.
AB - OBJECTIVE: To identify mitochondrial DNA (mtDNA) mutations that predispose to PD.
BACKGROUND: Mitochondrial complex I activity is deficient in PD. mtDNA mutations
may account for the defect, but the specific mutations have not been identified.
METHODS: Complete sequencing was performed of all mtDNA-encoded complex I and
transfer RNA (tRNA) genes in 28 PD patients and 8 control subjects, as well as
screening of up to 243 additional PD patients and up to 209 control subjects by
restriction digests for selected mutations. RESULTS: In the PD patients, 15
complex I missense mutations and 9 tRNA mutations were identified. After
screening additional subjects, rare PD patients were found to carry complex I
mutations that altered highly conserved amino acids. However, no significant
differences were found in the frequencies of any mutations in PD versus control
groups. The authors were unable to confirm previously reported associations of
mutations at nucleotide positions (np) 4336, 5460, and 15927/8 with PD. Complex I
mutations previously linked to Leber's hereditary optic neuropathy, one of which
has been linked to atypical parkinsonism, were not associated with PD.
CONCLUSIONS: mtDNA mutations with a high mutational burden (present in a high
percentage of mtDNA molecules in an individual) in complex I or tRNA genes do not
play a major role in the risk of PD in most PD patients. Further investigations
are necessary to determine if any of the rare mtDNA mutations identified in PD
patients play a role in the pathogenesis of PD in those few cases.
PMID- 10680808
TI - Objective changes in motor function during placebo treatment in PD.
AB - OBJECTIVE: To examine the frequency, temporal development, and stability of
objectively derived motor changes during placebo treatment in PD and to define
the clinical domains and demographic groups most affected. BACKGROUND: Placebo
effects are documented in neurology, but the timing and specific disabilities
most susceptible to changes during placebo treatment in PD have not been
examined. METHODS: The authors examined the placebo-treated group from a
randomized, multicenter, placebo-controlled clinical trial of monotherapy
ropinerole in PD patients without motor fluctuations. In 105 patients, they
evaluated placebo-associated effects on the motor section of the Unified
Parkinson's Disease Rating Scale (UPDRS), dividing the motor examination into
four categories: tremor, bradykinesia, rigidity, and gait/balance/midline
functions. The motor UPDRS and its subscales were compared over time (at baseline
and at 4, 12, and 24 weeks) using Wilcoxon's signed rank test. They applied a
rigorous definition of placebo-associated improvement as an improvement over
baseline score in motor UPDRS of at least 50% or a change in at least two motor
items at any one visit by > or =2 points. RESULTS: During the 6-month study, 16%
of subjects improved on placebo treatment. The prevalence of response was steady
(8 to 9%) at any one visit without a predominance of an early effect. No patient
showed a placebo-associated improvement on all visits. All domains of
parkinsonian disability were subject to placebo-associated improvement, with a
trend toward more response in bradykinesia and rigidity than in tremor or
gait/balance/midline function. Gender, age, disease duration, and baseline
disability score did not influence the likelihood of improvement in association
with placebo treatment. CONCLUSION: Based on a rigorous definition of placebo
associated improvement, prominent improvements in objective measures of PD
disability occur during clinical trials. Because placebo-associated improvements
occur throughout a 6-month trial, placebo-controlled studies in PD should be at
least 6 months to capture early as well as late improvements.
PMID- 10680809
TI - Quantitative 1H MR spectroscopic imaging in early Rett syndrome.
AB - OBJECTIVE: To determine cerebral regional concentrations of N-acetyl aspartate
(NAA), total choline (Cho), and total creatine (Cr) in Rett syndrome (RS) using
1H magnetic resonance spectroscopic imaging (MRSI). BACKGROUND: The biochemical
defect underlying RS is unknown. Because in vivo MRSI can detect important
cerebral metabolites, MRSI has a potential to reveal impairment of regional
cerebral metabolism in RS noninvasively. METHODS: High-resolution, multislice 1H
MRSI was carried out in 17 girls with RS. The control group consisted of nine
healthy children. RESULTS: In patients with RS, average Cho concentration was 12%
higher (p < 0.005) and average NAA concentration 11% lower (p < 0.0001) compared
with the control group. Regional metabolic differences included significantly
lower NAA concentration in the frontal gray and white matter, insula, and
hippocampus in RS; no difference in regional Cho and Cr concentrations were
found. A 20 to 38% higher Cho:NAA ratio in frontal and parietal gray and white
matter, insular gray matter, and hippocampus (p < 0.05) and a 14 to 47% lower
NAA:Cr ratio in frontal cortical gray matter, parietal and temporal white matter,
insula, and putamen (p < 0.05) were found in subjects with RS compared with
controls. Patients with seizures had higher average concentrations of Cho, Cr,
and NAA compared with those without seizures (8-19%, p < 0.05). CONCLUSION:
Metabolic impairment in RS involves both gray and white matter and particularly
involves frontal and parietal lobes and the insular cortex. Loss of NAA most
likely reflects reduced neuronal and dendritic tree size; increased Cho
concentration may result from gliosis.
PMID- 10680810
TI - Vestibular hypersensitivity to sound (Tullio phenomenon): structural and
functional assessment.
AB - OBJECTIVES: To establish the role of high-resolution CT imaging and tests of
vestibulocollic reflexes in diagnosing and understanding the pathogenesis of the
Tullio phenomenon. BACKGROUND: The Tullio phenomenon is a syndrome in which
acoustic stimulation produces symptoms and signs of vestibular activation. It has
previously been associated with an abnormally low threshold for click-evoked
vestibulocollic responses and also with dehiscence of the roof of the anterior
(superior) semicircular canal on high-resolution CT scans of the temporal bones.
METHODS: High-resolution CT scans of the temporal bones and vestibulocollic
responses in sternocleidomastoid to both clicks and transmastoid galvanic
stimulation (3 mA/2 msec) were studied in four patients with the Tullio
phenomenon (one bilateral). RESULTS: Click-evoked thresholds were low for all
affected ears (four at 65 dB nHL, one at 55 dB nHL) and normal (>70 dB nHL) for
the three unaffected ears. In contrast, galvanic-evoked vestibulocollic responses
were symmetric and of normal size in all patients. The bony roof of the anterior
(superior) semicircular canal was thin, possibly absent, on CT of all affected
ears and also in two out of three unaffected ears. CONCLUSIONS: The normal
galvanic vestibulocollic responses indicate that sound sensitivity in patients
with the Tullio phenomenon is likely to occur distal to the vestibular nerve,
probably at the level of the receptors. Both click hypersensitivity and
dehiscence of the anterior (superior) semicircular canal are associated with the
Tullio phenomenon but as the CT scan abnormality can occur in clinically
unaffected ears, click testing is important for specific diagnosis. Abnormal
sound sensitivity, as demonstrated by click responses, confirms that the
radiologic abnormality is function significant.
PMID- 10680811
TI - Genetic analysis of vitamin D related genes in Canadian multiple sclerosis
patients. Canadian Collaborative Study Group.
AB - The objective of this study was to investigate genes involved in the metabolism
and function of vitamin D as candidate genes for genetic susceptibility to MS.
Restriction fragment length polymorphisms and highly polymorphic microsatellite
markers within or very close to the 1,25(OH)2D3 receptor (VDR) [12q14], the
vitamin D binding protein (DBP) [4q12], and the 25(OH)D2 1alpha-hydroxylase
[12q13] loci were analyzed for linkage or association with MS. We found no
evidence for linkage or association of these candidate genes with MS in the
Canadian population.
PMID- 10680812
TI - Anti-inflammatory drugs and Alzheimer-type pathology in aging.
AB - Anti-inflammatory drugs have been suggested as a treatment for AD. The authors
examined the AD-type pathology in postmortem brain tissue from elderly
nondemented individuals who were chronically exposed to anti-inflammatory drugs.
The results suggest that 1) these drugs do not affect the formation of either
senile plaques or neurofibrillary tangles and 2) nonsteroidal anti-inflammatory
drugs may be more effective than steroids in treating AD because of their ability
to suppress the microglial activation associated with senile plaques.
PMID- 10680813
TI - Cerebrospinal fluid pyruvate levels in Alzheimer's disease and vascular dementia.
AB - Increased amounts of CSF pyruvate and lactate were found in patients with AD and
patients with vascular dementia (VaD). In the AD group, CSF pyruvate values did
not show any overlap with those obtained in controls; within the VaD group, the
highest values were observed in possible VaD cases. A significant correlation
between the severity of dementia and these biochemical parameters was also
observed in both AD and possible VaD. The similarities of CSF pyruvate patterns
observed in AD and possible VaD patients implicate a neurodegenerative component
in this VaD subgroup.
PMID- 10680814
TI - Amnesic syndrome with bilateral mesial temporal lobe involvement in Hashimoto's
encephalopathy.
AB - A 25-year-old woman presented with a subacute confusional state, headaches,
unsteadiness, myoclonus, seizures, and an amnesic syndrome as a manifestation of
Hashimoto's encephalopathy. Investigations showed biochemical hypothyroidism,
raised thyroid microsomal antibodies, and weakly positive antineuronal
antibodies. A T2-weighted MRI of the brain showed bilateral symmetric areas of
increased signal in the mesial temporal lobes and hippocampi that had a low
signal intensity on T1-weighted imaging. Despite clinical and radiologic
improvement after steroid and thyroid hormone replacement therapy, a severe
amnesic syndrome with associated localized MRI abnormalities persists.
PMID- 10680815
TI - Frequency and duration of hospitalization of patients with AD based on Medicare
data: CERAD XX.
AB - Medicare records on 477 Consortium to Establish a Registry for Alzheimer's
Disease patients with AD for 1991 through 1995 showed a hospitalization rate of
0.37/person-year with a length of stay of 3.7 days/ person-year (average of 10
days/hospitalization). Unmarried and less-educated patients with AD were admitted
to the hospital more frequently, and, along with black patients, had a longer
length of stay. Frequency and duration of hospitalization were greater in the
patients with AD than in Medicare beneficiaries in general, but the rate of
diagnostic/therapeutic procedures was lower.
PMID- 10680816
TI - AIDS- and non-AIDS-related PML association with distinct p53 polymorphism.
AB - A population-based analysis of progressive multifocal leukoencephalopathy (PML)
showed PML frequencies of 5.1% among patients with AIDS and 0.07% among patients
with hematologic malignancies, but similar clinical features of PML in both
groups. Sequencing of the p53 gene, exon 4, showed heterozygosity (Arg-Pro) at
codon 72 in five of six PML patients. These findings indicate that frequencies of
non-AIDS- and AIDS-related PML differ markedly but p53 polymorphisms may
influence the occurrence of PML in both groups.
PMID- 10680817
TI - Positive CSF HSV PCR in patients with GBM: a note of caution.
AB - Because two patients with temporal lobe glioblastomas had herpes simplex (HSV)
DNA detected in CSF using PCR at the time of their presentation, we reviewed our
laboratory's experience and performed PCR on a bank of 159 frozen CSF samples
from patients with glioblastoma multiforme and other neurologic disorders. Based
on the inability to detect HSV in any other tumor sample, we conclude that the
positive HSV PCR in our two index patients most likely represented false-positive
results. A diagnosis of HSE should not be made by PCR alone when the clinical
presentation is atypical.
PMID- 10680818
TI - Natural history of aortic arch atherosclerotic plaque.
AB - To define the natural history of aortic arch plaque, we used B-mode
ultrasonography to perform sequential study of the aortic arch. Eighty-nine
patients were studied for up to 18 months. There was no change in 67% of total
plaques; 77% of simple plaque (<4 mm) and 48% of complex plaque (> or =4 mm) did
not progress. Atherosclerosis of the aortic arch can be sequentially studied with
B-mode ultrasonography, and most of these lesions remain unchanged after up to 18
months of observation.
PMID- 10680819
TI - Cerebral deep venous thrombosis presenting as acute micrographia and hypophonia.
AB - Deep cerebral venous thrombosis is often a devastating condition associated with
hemorrhagic infarction. We describe a patient who presented with acute
micrographia and hypophonia as the sole manifestations of extensive deep venous
sinus thrombosis.
PMID- 10680820
TI - Acute hydrocephalus in nonketotic hyperglycinemia.
AB - We present four patients with typical neonatal onset non-ketotic hyperglycinemia
(NKH) who developed hydrocephalus requiring shunting in early infancy. Brain
imaging revealed acute hydrocephalus, a megacisterna magna or posterior fossa
cyst, pronounced atrophy of the white matter, and an extremely thin corpus
callosum in all. The three older patients had profound developmental
disabilities. This suggests that the development of hydrocephalus in NKH is an
additional poor prognostic sign.
PMID- 10680821
TI - Recombinant calcium channel is recognized by Lambert-Eaton myasthenic syndrome
antibodies.
AB - The authors studied sera from 36 patients with Lambert-Eaton myasthenic syndrome
(LEMS) by immunoblots using the recombinant protein derived from the DNA sequence
encoding for the domain III S5-S6 linker of the P/Q-type voltage-gated calcium
channel al subunit. The results of 18 patients were positive for antibodies to
this recombinant protein. The results of 2 of 10 patients with lung cancer
without LEMS were also positive.
PMID- 10680822
TI - Neurogenic stunned myocardium in Guillain-Barre syndrome.
AB - Neurogenic stunned myocardium (NSM), a syndrome of reversible left ventricular
dysfunction best described after subarachnoid hemorrhage, has not been associated
with peripheral neuropathy. We describe a woman with Guillain-Barre syndrome in
whom a syndrome compatible with NSM developed in the setting of a physiologically
documented increase in sympathetic cardiovascular tone. This case supports the
presumed unifying role of excessive sympathetic nervous system activation in the
pathogenesis of NSM.
PMID- 10680823
TI - "Tactile" sensory nerve potentials elicited by air-puff stimulation: a
microneurographic study.
AB - To investigate the sensory nerve responses to selective touch stimulation,
sensory nerve action potentials after brief air-puffs were recorded with a
microelectrode. In patients with peripheral neuropathy, those with impairment of
tactile sensations had significantly smaller responses than did those without
tactile impairment, suggesting receptor activation failure as well as nerve
conduction failure. Brief air-puff stimulation, when combined with
microneurography, could be used for evaluating the tactile receptor properties in
humans.
PMID- 10680824
TI - Cortical reorganization after acute unilateral hearing loss traced by fMRI.
AB - Unilateral acoustic stimulation produces a functional MRI (fMRI)-blood
oxygenation-level-dependent (BOLD) response mainly in the contralateral auditory
cortex. In unilateral deaf patients, the BOLD response is bilateral. We studied a
subject with sudden hearing loss after cochlear nerve resection before and
repeatedly after surgery. During normal bilateral hearing, contralateral cortical
BOLD responses were found. Progressing compensatory reorganization with bilateral
representation of unilateral stimulation was detected over a period of
approximately 1 year.
PMID- 10680825
TI - The risk of abducens palsy after diagnostic lumbar puncture.
PMID- 10680826
TI - Hashimoto encephalopathy: a brainstem vasculitis?
PMID- 10680827
TI - Acute idiopathic dysautonomia: electrophysiology and response to intravenous
immunoglobulin.
PMID- 10680828
TI - Morvan's syndrome associated with voltage-gated K+ channel antibodies.
PMID- 10680829
TI - POEMS syndrome with necrotizing vasculitis: a novel feature of vascular
abnormalities.
PMID- 10680830
TI - Arm levitation in progressive supranuclear palsy.
PMID- 10680831
TI - Arm levitation in progressive supranuclear palsy.
PMID- 10680832
TI - Ventricular asystole during vagus nerve stimulation for epilepsy in humans.
PMID- 10680833
TI - Ventricular asystole during vagus nerve stimulation for epilepsy in humans.
PMID- 10680834
TI - An active-control trial of lamotrigine monotherapy for partial seizures.
PMID- 10680835
TI - The influence of smoking on the risk of Alzheimer's disease.
PMID- 10680836
TI - Isolated Echinococcus granulosus hydatid cyst in the CNS with severe reaction to
treatment.
PMID- 10680837
TI - Effective gene therapy for pancreatic cancer by cytokines mediated by restricted
replication-competent adenovirus.
AB - Pancreatic cancer has a poor prognosis even when surgical treatment can be
accomplished. Studies have demonstrated that pancreatic cancer is associated with
various genetic abnormalities in oncogenes and tumor suppressor genes including
p53. New therapeutic approaches for pancreatic cancer can be developed by
targeting these genetic alterations. Adenovirus (Adv) lacking the 55-kDa E1B
protein (E1B55K) replicates preferentially in p53-deficient cancer cells. We
constructed E1B55K-deleted Adv (AxE1AdB), and studied its replication and
cytopathic effect on pancreatic cancer cells. AxE1AdB replicated in and caused
cell death of the p53-deficient pancreatic cancer cell lines tested (e.g., PANC
1, MIAPaCa-2, SU.86.86, BxPC-3, and PK-1). To enhance its therapeutic effect, we
examined the combination of coinfecting this restricted replication-competent
adenovirus (RRCA) with other Adv. Coinfection of E1-deficient Adv expressing the
reporter lacZ gene (AxCAlacZ) together with AxE1AdB resulted in the replication
of both viruses and a marked increase in reporter gene expression. PANC-1 cells
coinfected with AxE1AdB and the Adv for human IL-2 (AxCAhIL2), produced 110 times
more IL-2 than those infected with AxCAhIL2 alone. Similarly, coinfection of
AxE1AdB and Adv for human IL-12 augmented the IL-12 production by 370-fold.
Injecting AxE1AdB into the PANC-1 tumor of severe combined immunodeficient mice
(SCID mice) resulted in marked reduction of the volume of the tumor. Moreover,
injecting AxE1AdB with AxCAhIL2 into the PANC-1 tumor resulted in complete
regression of the established tumors. These data suggest that RRCA, which
augments the antitumor effect of a viral transgene (i.e., cytokines), may be a
powerful tool for treating p53-deficient pancreatic cancer.
PMID- 10680838
TI - Analysis of adenoviral transport mechanisms in the vessel wall and optimization
of gene transfer using local delivery catheters.
AB - Local delivery devices have been used for adenovirus-mediated gene transfer to
the arterial wall for the potential treatment of vascular proliferative diseases.
However, low levels of adenoviral gene expression in vascular smooth muscle cells
may pose a serious limitation to the success of these procedures in the clinic.
In this study, we examined the mechanisms controlling adenoviral transport to the
vessel wall, using both hydrogel-coated and infusion-based local delivery
catheters, with the goal of enhancing in vivo gene transfer under clinically
relevant delivery conditions. The following delivery parameters were tested in
vivo: applied transmural pressure, viral solution volume and concentration, and
delivery time. We found that viral particles are transported into the vessel wall
in a manner consistent with diffusion rather than pressure-driven convection.
Consistent with diffusion, viral concentration was shown to be the key variable
for viral transport in the vessel wall and thus gene expression in vascular
smooth muscle cells. A transduction level of 17.8+/-3.2% was achieved by
delivering a low volume of concentrated adenoviral beta-galactosidase solution
through an infusion balloon catheter at low pressure without an adverse effect on
medial cellularity. Under these conditions, effective gene transfer was
accomplished within a clinically relevant time frame of 2 min, indicating that
longer delivery times may not be necessary to achieve efficient gene transfer.
PMID- 10680839
TI - The CXC chemokine, monokine induced by interferon-gamma, inhibits non-small cell
lung carcinoma tumor growth and metastasis.
AB - Angiogenesis is an absolute requirement for tumor growth beyond 2 mm3 in size.
The balance in expression between opposing angiogenic and angiostatic factors
controls the angiogenic process. The CXC chemokines are a group of chemotactic
cytokines that possess disparate activity in the regulation of angiogenesis. Non
small cell lung carcinoma (NSCLC) has an imbalance in expression of ELR+
(angiogenic) compared with ELR- (angiostatic) CXC chemokines that favors
angiogenesis and progressive tumor growth. We found that the level of the ELR-
CXC chemokine MIG (monokine induced by interferon gamma) in human specimens of
NSCLC was not significantly different from that found in normal lung tissue.
These results suggested that the increased expression of ELR+ CXC chemokines
found in these tumor samples is not counterregulated by a concomitant increase in
the expression of the angiostatic ELR-CXC chemokine MIG. This would result in an
even more profound imbalance in the expression of regulatory factors of
angiogenesis that would favor neovascularization. We hypothesized that MIG might
be an endogenous inhibitor of NSCLC tumor growth in vivo and that reconstituion
of MIG in the tumor microenvironment would result in the inhibition of tumor
growth and metastasis. In support of this hypothesis, we demonstrate here that
overexpression of the ELR-CXC chemokine MIG, by three different strategies
including gene transfer, results in the inhibition of NSCLC tumor growth and
metastasis via a decrease in tumor-derived vessel density. These findings support
the importance of the ELR- CXC chemokine MIG in inhibiting NSCLC tumor growth by
attenuation of tumor-derived angiogenesis. Furthermore, these findings
demonstrate the potential of gene therapy as an alternative means to deliver and
overexpress a potent angiostatic CXC chemokine.
PMID- 10680840
TI - Catheter-mediated vascular endothelial growth factor gene transfer to human
coronary arteries after angioplasty.
AB - Blood vessels are among the easiest targets for gene therapy. However, no data
are available about the safety and feasibility of intracoronary gene transfer in
humans. We studied the safety and efficacy of catheter-mediated vascular
endothelial growth factor (VEGF) plasmid/liposome (P/L) gene transfer in human
coronary arteries after percutaneous translumenal coronary angioplasty (PTCA) in
a randomized, double-blinded, placebo-controlled study. The optimized
angioplasty/gene delivery method was previously shown to lead to detectable VEGF
gene expression in human peripheral arteries as analyzed from amputated leg
samples. Gene transfer to coronary arteries was done with a perfusion-infusion
catheter, using 1000 microg of VEGF or beta-galactosidase plasmid complexed with
1000 microl of DOTMA:DOPE liposomes. Ten patients received VEGF P/L, three
patients received beta-galactosidase P/L, and two patients received Ringer
lactate. Gene transfer to coronary arteries was feasible and well tolerated.
Except for a slight increase in serum C-reative protein in all study groups, no
adverse effects or abnormalities in laboratory parameters were detected. No VEGF
plasmid or recombinant VEGF protein was present in the systemic circulation after
the gene transfer. In control angiography 6 months later, no differences were
detected in the degree of coronary stenosis between treatment and control groups.
We conclude that catheter-mediated intracoronary gene transfer performed after
angioplasty is safe and well tolerated and potentially applicable for the
prevention of restenosis and myocardial ischemia.
PMID- 10680841
TI - Retroviral vector-mediated gene expression in human CD34+CD38- cells expanded in
vitro: cis elements of FMEV are superior to those of Mo-MuLV.
AB - A novel murine stromal cell line, HESS-M28, was established, which supports the
expansion of human CD34+CD38- cells more than 300-fold in vitro in the presence
of human IL-3 and SCF. These cells were used in an attempt to evaluate cis-acting
elements of retroviral vectors in human primitive hematopoietic cells. Cord blood
cells were cultured on top of the mixed cell layers of the stromal cell line,
HESS-M28, and retroviral vector-producing cells. The FMEV-type vector SF/Lyt
contained the spleen focus-forming virus U3 and the MESV primer-binding site
(PBS), while MO3/Lyt contained the U3 region and PBS from Mo-MuLV. After
transduction by the FMEV-type and Mo-MuLV-based vectors, expression of the marker
gene murine CD8 (mCD8) was examined in CD34-, CD34+, and CD34+CD38- cells. In
CD34+ and CD34+CD38- cells, expression of mCD8 was higher with the FMEV-type
vector, SF/Lyt, compared with the cells transduced by the Mo-MuLV-based vector
MO3/Lyt, although the expression was comparable in CD34- cells. Expression of
marker genes was also confirmed in long-term culture-initiating cells (LTC-ICs)
and SCID-repopulating cells (SRCs).
PMID- 10680842
TI - Regressions of established breast carcinoma xenografts by carboxypeptidase G2
suicide gene therapy and the prodrug CMDA are due to a bystander effect.
AB - The role of the bystander effect in the treatment of a human breast carcinoma
xenograft was studied by suicide gene therapy with carboxypeptidase G2 (CPG2) and
CMDA. Cells expressing enzymatically active surface-tethered bacterial CPG2
[stCPG2(Q)3] were mixed with control beta-galactosidase (beta-Gal)-expressing
cells to give stCPG2(Q)3:beta-Gal ratios of, respectively: group 1, 0:100; group
2, 10:90; group 3, 50:50; and group 4, 100:0. Four days after injection of the
cells into nude mice, the prodrug 4-[(2-chloroethyl)(2
mesyloxyethyl)amino]benzoyl-L-glutamic acid (CMDA) was administered. Tumor growth
delay correlated well with the levels of stCPG2(Q)3 expression: group 1, 0 day
delay; group 2, 10 days; group 3, 16 days; and group 4, 90 days. Similarly, the
number of cures was strongly correlated to the levels of stCPG2(Q)3 activity:
group 1, zero of six cured; group 2, one of six cured; group 3, three of six
cured and group 4, four of six cured. There was a good correlation between CPG2
enzyme activity in the tumors and the number of cures. The majority of cells from
groups 2 and 3 were apoptotic whereas those from group 1 were not, indicating a
substantial bystander effect in the tumors. These results suggest that a
bystander effect plays a major role in suicide gene therapy regimens with
stCPG2(Q)3 and CMDA.
PMID- 10680843
TI - Targeting human T cells by retroviral vectors displaying antibody domains
selected from a phage display library.
AB - To generate T cell-specific retroviral vectors an scFv phage display library
derived from immunized mice was selected for binding to the human T cell line
Molt-4/8. The scFv cDNAs recovered from the selected phages were transiently
expressed as an N-terminal fusion of the spleen necrosis virus (SNV)
transmembrane protein (TM) subunit of the viral envelope protein (Env) in the
cell line DSH-cxl, which packages the beta-galactosidase gene into SNV particles.
Screening of supernatants from about 150 transfections resulted in the
identification of 5 scFvs that mediated efficient transduction of Molt-4/8 cells.
Using stable packaging cell lines vector preparations with titers greater than
10(4) EFU/ml on human T cells were obtained. The scFv 7A5 in particular was able
to mediate selective transduction of human T cells with high efficiency. Titers
of up to 106 EFU/ml were reached on Molt-4/8, Jurkat, and A301 cells, while
titers on HeLa cells, TE671 cells, 293T cells, and HT1080 cells were below 102
EFU/ml. Transduction of stimulated primary human peripheral blood cells, which
consisted mainly of T cells, was about fivefold more efficient than transduction
of B cells. Western blot analysis of supernatant from the 7A5 packaging cells
demonstrated incorporation of 7A5-TM into vector particles and indicated
proteolytic processing of the coexpressed unmodified TM during particle
formation. Binding of bacterially expressed 7A5-scFv to a panel of cell lines
correlated well with the transduction results. These data provide the first proof
of concept that a general approach can be taken to obtain scFvs able to mediate
selective gene transfer into target cells.
PMID- 10680844
TI - Macrophage colony-stimulating factor can modulate immune responses and attract
dendritic cells in vivo.
AB - Studies have indicated that professional APCs in the periphery, such as dendritic
cells and macrophages, play an important role in initiating DNA vaccine-specific
immune responses. To engineer the immune response induced by DNA vaccines in vivo
we investigated the modulatory effects of codelivering growth factor genes for
the hematopoietic APCs along with DNA vaccines. Specifically, we examined the
effects on the antigen-specific immune responses following the codelivery of the
gene expression cassettes for M-CSF, G-CSF, and GM-CSF along with HIV-1 DNA
immunogen constructs. We observed that coimmunization with GM-CSF increased the
antibody response and resulted in a significant enhancement of
lymphoproliferative response. Furthermore, among all coinjection combinations, we
found that M-CSF coinjections resulted in a high level of CTL enhancement. This
enhancement of CTL responses observed from the coinjection with M-CSF was CD8+ T
cell dependent and was associated with the presence of CD11c+ cells at the site
of injection and with the antigen-specific induction of the beta-chemokine MIP
1beta, suggesting a role for this chemokine in CTL induction. These results
suggest that hematopoietic growth factors should be further studied as potential
adjuvants for in vivo modulators of immune responses.
PMID- 10680845
TI - Lentiviral and murine retroviral transduction of T cells for expression of human
CD40 ligand.
AB - Efficient transduction of primary human T cells is an important goal toward
treating a number of genetic defects. Patient T cells could be harvested by
leukapheresis, transduced, and returned to the donor. A wide range of secreted or
cell surface therapeutic proteins may be delivered in this way. The ability to
produce antibodies is the consequence of interactions between T cells and B cells
and lack of expression of CD40 ligand (CD40L) on T cells causes X-linked hyper
IgM syndrome (XHIM). We are investigating delivery of a normal CD40 ligand to
treat this disorder. We tested promoters driving the expression of either
reporter genes such as enhanced green fluorescent protein (eGFP) or human CDC40L.
Using murine retroviruses, the best able to drive gene expression in T cells was
the cytomegalovirus (CMV) promoter enhancer element; however, transduction
efficiency was low. To achieve efficient, high-level gene expression we tested
lentiviral gene delivery vectors. At a low multiplicity of infection (MOI) (0.5
2) a large fraction of target cells was transduced by lentiviral vectors (40
93%), and the strength of gene expression was high, as determined by flow
cytometric analysis. We monitored the expression of eGFP or human CD40L on T cell
lines and untransformed primary human T cells from normal and CD40L-deficient
patients. We achieved efficient gene expression without an extended exposure to
virus, and without the need for selection. These results are encouraging for
efficient lentivirus-mediated transduction of refractory human cells to achieve
therapeutic gene delivery.
PMID- 10680846
TI - DeltahGHR, a novel biosafe cell surface-labeling molecule for analysis and
selection of genetically transduced human cells.
AB - We describe a new selectable marker for retroviral transduction and selection of
human and murine cells. The molecule expressed on the cell surface of the
transduced population is a truncated version of human growth hormone receptor
(deltahGHR), capable of ligand (hGH) binding, but devoid of the domains involved
in signal triggering. We demonstrate that the engineered molecule is stably
expressed in the target cells as an inert protein unable to trigger proliferation
or to rescue the cells from apoptosis after ligand binding. This new marker will
probably have a wide application spectrum, since hGHR in the human adult is
highly expressed only in liver cells, and lower levels have been reported in
certain lymphocyte cell populations. The deltahGHR label has high biosafety
potential, as it belongs to a well-characterized hormonal system that is
nonessential in adults, and there is extensive clinical experience with hGH
administration in humans. This record allows us to hypothesize the lack of
relevant clinical consequences resulting from massive transgene expression caused
by successful replacement of a large tissue with genetically transduced cells. We
take advantage of the differential binding properties of several monoclonal
antibodies (MAbs) in describing a cell rescue method in which the antibody used
to select deltahGHR-transduced cells is eluted by competition with hGH or,
alternatively biotinylated hGH is used to capture tagged cells. In the latter
system, the final purified population would be recovered free of attached
antibodies in hGH (a substance approved for human use)-containing medium,
providing additional biosafety relative to currently existing methods that rely
on the use of murine MAb to rescue genetically labeled cells.
PMID- 10680847
TI - Anti-human immunodeficiency virus type 1 gene therapy in human central nervous
system-based cells: an initial approach against a potential viral reservoir.
AB - Studies have demonstrated that human immunodeficiency virus type 1 (HIV-1)
infection of central nervous system (CNS)-based cells in vivo results in a series
of devastating clinical conditions collectively termed acquired immune deficiency
syndrome (AIDS) dementia complex (ADC). Gene therapy for these neurovirological
disorders necessitates utilization of a vector system that can mediate in vivo
delivery and long-term expression of an antiretroviral transgene in
nondividing/postmitotic CNS cellular elements. The present studies focus on the
transfer of an anti-HIV-1 gene to primary isolated CNS microvascular endothelial
cells (MVECs) and neuronal-based cells, for its effects in protecting these cells
from HIV-1 infection. By using an HIV-1-based vector system, it was possible to
efficiently transduce and maintain expression of a marker transgene, beta
galactosidase (beta-Gal), in human CNS MVECs, human fetal astrocytes, plus
immature and mature (differentiated) NT2 cells. Significant transduction of the
marker gene, beta-Gal, in CNS-based cells prompted the utilization of this system
with an anti-HIV-1 gene therapeutic construct, RevM10, a trans-dominant negative
mutant Rev protein. Initially, it was not possible to generate any HIV-1 vector
particles with the RevM10 gene in the transducing construct, because of
inhibitory effects on the HIV-1 vector by this gene product. However, the vector
could be partially rescued by adding an additional construct that supplied wild
type rev, in trans, during a multiple construct transfection in the packaging
293T cells. Thus, it was possible to significantly improve the titer of RevM10
expressing viral particles generated from these cells. Moreover, this RevM10
vector transduced the neuronal precursor cell line NT2, retinoic acid
differentiated human neurons (hNT) from the precursor cells, and primary isolated
human brain MVECs with high efficiency. RevM10 generated from the HIV-1-based
vector system potently inhibited replication of diverse HIV-1 strains in human
CNS MVECs and neuronal cells. The data generated from these studies represent an
initial approach for future development of anti-HIV-1 gene therapy in the CNS.
PMID- 10680848
TI - Coarse spray delivery to a localized region of the pulmonary airways for gene
therapy.
AB - Targeting adenoviral vectors for cystic fibrosis gene therapy to the human
airways with minimal exposure to alveoli would avoid adverse reactions and
maximize response. At present, to deliver gene therapy vectors, large volumes of
fluid are instilled or nebulized as aerosols. Either approach would likely cause
alveolar exposure and increases the potential for side effects. We describe a
coarse spray delivery device that precisely and reproducibly delivers the viral
vector to the human airways to treat a small region of the airways for clinical
trials. An endoscopic washing pipe (Olympus) that can be inserted into the
channel of a bronchoscope was used. To minimize the escape of the therapeutic
material downstream from the site of administration, we restricted the volume
delivered to <150 microl (to prevent bulk flow), and used large droplets. Their
high velocity further enhanced the probability of impaction in the vicinity of
the nozzle. A pneumatic dosing system (Kahnetics) was used to reproducibly
deliver the spray. The droplet size distribution was determined by laser
diffraction and confirmed by cascade impaction: 190-microm volume median diameter
with 1% mass <10 microm. The localization of the spray was studied in hollow cast
models of human airways. 99mTc-sulfur colloid was used as a radiolabeled marker
for these studies. Localization of the deposited spray was determined by
scintigraphy and by measuring the radioactivity exiting the terminal airways. In
the lung casts the spray was localized to one or two generations over an
approximately 2-cm2 area. We conclude that delivery of large droplet sprays
limits exposure to a few generations and may be useful in topical gene delivery
clinical trials.
PMID- 10680849
TI - Primary care options to prevent mental illness.
AB - The common mental disorders, mainly anxiety and depression, constitute a major
public health problem, incurring considerable costs in terms of use of health
services and time lost from work. Risk factors include low socioeconomic status,
poverty and poor housing, as well as stressful life events and difficulties such
as demanding child care, separation or divorce, bereavement, loss of employment
and caring for a dependant relative. Population approaches are probably necessary
to reduce significantly the burden of such mental health problems, but health
care measures are far from negligible. Primary care professionals have regular
opportunities to identify people at risk of mental health problems and refer them
to welfare and social support services (primary prevention). A number of
interventions among high-risk groups have been shown to be effective, including
problem-solving training and cognitive-behavioural approaches. The most important
tasks in primary care are to identify people with depression, alcohol and drug
misuse and eating disorders as early as possible in the course of their illness
and to institute effective treatment (secondary prevention). Primary care teams
should also join in shared care arrangements for patients with chronic disabling
mental illnesses, in order to prevent recurrences and relapses (tertiary
prevention).
PMID- 10680851
TI - Development of gender differences in depression: description and possible
explanations.
AB - This article reviews the description and possible explanations for the
development of gender differences in depression in children and adolescents. The
emerging gender difference (more girls depressed than boys) in depressed mood and
depressive disorders appears after the age of 13 years or midpuberty. Currently,
little evidence supports that biological factors are an explanation. Genetic
factors are associated more strongly with depression among pubertal girls than
boys. Regarding cognitive factors, ruminative response style, but not
dysfunctional attitudes or attributional style, has been supported to be a
possible explanation. Studies on childhood adversities and gender role have
provided evidence explaining why more girls are depressed than boys. Girls are
more likely to experience negative events in the family than boys, and these
adversities are in turn associated with elevated depression. Girls identify more
strongly with a feminine stereotype of needing to appear thin and consequently
become more dissatisfied with their body shape and physical appearance, which in
turn is associated with increased depression.
PMID- 10680850
TI - Euthanasia and physician-assisted suicide.
AB - In the Netherlands there are about 9700 explicit requests for euthanasia or
physician-assisted suicide (EAS) each year, of which approximately 3600 are
granted. Other countries have criticized the Dutch policy concerning EAS. It has
been suggested that palliative care in the Netherlands is not adequate and that
euthanasia is often requested by patients with depression. In addition, this
criticism is partly based on the firm stance that 'human life has an absolute
value and a human being has under no circumstances the right of self
determination over his or her own life'. Many aspects of EAS are currently the
focus of attention in the literature. In this review the following aspects of EAS
are discussed: ethics, judicial questions, the relationship between depression
and euthanasia, and the impact of EAS on members of the family. Also, the current
situation concerning EAS in the Netherlands is summarized and described. Despite
the fact that EAS have been widely discussed in the literature, the association
between depression and the number of requests for EAS remains to be discovered.
It is also not yet known what the effects of EAS are on members of the family,
and whether unnatural death causes a higher incidence of complicated grief.
PMID- 10680852
TI - Memory retrieval under the control of the prefrontal cortex.
AB - Memory retrieval is a process wherein a distributed neural network reactivates
the brain's representation of past experiences. Sensory long-term memory is
represented among a population of neurones in the modality-specific posterior
association cortex. The coded representation of memory can be retrieved by
interactions of hierarchically different cortical areas along bottom-up and top
down anatomical connections. We examined the function of the prefrontal cortex in
memory retrieval by two different approaches. Firstly, a meta-analysis of brain
imaging studies revealed that the prefrontal cortex is reliably activated by
memory retrieval in humans. Secondly, in order to determine the causal
relationship between the prefrontal activations and memory retrieval, we designed
a new experimental paradigm using posterior-split-brain monkeys. Following
section of the splenium of the corpus callosum and the anterior commissure,
visual stimulus-stimulus association learning within one hemisphere did not
transfer to the other. Nevertheless, when a visual cue was presented to one
hemisphere, the prefrontal cortex could instruct the contralateral hemisphere to
retrieve the correct stimulus specified by the cue. These findings suggest that
the prefrontal cortex can regulate the recall of long-term memory in the absence
of bottom-up sensory inputs.
PMID- 10680853
TI - Medical treatment of erectile dysfunction.
AB - Erectile dysfunction (ED) is defined as the consistent inability to obtain or
maintain an erection for satisfactory sexual relations. Data from the
Massachusetts Male Aging Study have indicated that the prevalence of erectile
dysfunction of any degree is 39% in 40-year old men, and 67% in those aged 70
years. Effective therapy has been available for some time, but it has commonly
involved surgery, external devices or penile self-injection. For many men, these
represent unacceptable barriers to seeking therapy. Recently, however, an
effective oral medication has become available. This article reviews the
physiology and pharmacology of ED. The literature currently available on the
effectiveness and safety of various drugs used for ED is summarized, with
particular attention to newly available oral agents. Guidelines for work-up and
drug treatment of patients with ED are given. Detailed history and physical
examination are crucial to the safe and effective treatment of men with erectile
impotence. An extensive review of the literature shows that based on safety,
effectiveness and ease of use, oral sildenafil citrate is an excellent choice for
first-line therapy. Patients who use organic nitrates of any kind in any capacity
should not be offered sildenafil. Based solely on effectiveness intracavernosal
injection therapy remains the golden standard and should also be offered as an
option for first-line therapy for the appropriate patients. Many alternatives are
available for men who cannot use sildenafil or injection therapy. A thorough
knowledge of existing medications is essential for proper treatment of ED.
PMID- 10680854
TI - New diagnostic findings in coeliac disease.
AB - Coeliac disease, a life-long gluten-sensitive disorder, characterized by
malabsorption, villous atrophy and crypt hyperplasia, is well recognized.
However, the disease is evidently underdiagnosed, and the classic forms
constitute only the tip of the 'coeliac iceberg'. Patients with coeliac disease
can have subtle symptoms, if any. Diagnostic difficulties may further emerge when
minor mucosal changes are found. In coeliac screening and case-finding a novel
test, the antitissue transglutaminase test, has proven promising with a
sensitivity and specificity of over 95 %. Genetic and immunohistological research
has taken a great leap forward. Coeliac disease is strongly associated with HLA
DQ2, coded by the DQA1*0501 and DQB1*02 alleles, or the DQ8 (DQA1*03, DQB1*0302
alleles). The disease is rare in patients who do not share these alleles, a
circumstance which can be utilized in diagnostics. An increase in small bowel
intraepithelial lymphocytes especially gammadelta+ T-cell receptor-bearing cells
is typical, albeit not pathognomonic, for coeliac disease. Combining new
symptoms, humoral immunity, genetics and immunohistological staining can today
offer a greater diagnostic scope for coeliac disease, especially in cases where
clinical presentation and small bowel biopsy findings remain doubtful.
PMID- 10680855
TI - Neurological channelopathies: diagnosis and therapy in the new millennium.
AB - Rapid progress in the complementary fields of molecular genetics and cellular
electrophysiology has led to a better understanding of many disorders which are
caused by ion channel dysfunction. These channelopathies may manifest in a
multitude of ways depending on the tissue specificity of the channel that is
affected. Several important general medical conditions are now known to be
channelopathies but the neurological members of this family are amongst the best
characterized. Over recent years, ion channel dysfunction in skeletal muscle in
particular has emerged as a paradigm for understanding neurological ion channel
disorders. This review concentrates mainly on the diseases caused by dysfunction
of the voltage-gated ion channels. We initially focus on the skeletal muscle
channelopathies (the periodic paralyses, malignant hyperthermia, paramyotonia
congenita and myotonia congenita). The central nervous system channelopathies are
then explored, with particular reference to the advances which have implications
for understanding the mechanisms of common neurological disorders such as
epilepsy and migraine. Looking towards the new millennium, DNA-based diagnosis
will become a realistic proposition for most neurological channelopathies.
Furthermore, it seems likely that new therapies will be designed based on
genotype and mode of ion channel dysfunction.
PMID- 10680856
TI - In situ use of suicide genes for therapy of brain tumours.
AB - Suicide gene therapy represents a new therapeutic approach to the treatment of
patients with otherwise incurable malignant brain tumours. This strategy involves
the introduction of a gene that renders the tumour cell susceptible to an
otherwise nontoxic prodrug. The most often used genetic prodrug activation system
is the herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) paradigm.
An important aspect of this system is the 'bystander effect', the extension of
cytotoxic effects to untransduced cells. For gene delivery, retroviral,
adenoviral vectors and HSV-1 mutants have been used. Clinical studies have
revealed that the HSV-tk/GCV approach is safe, but also that responses are
observed only in very small brain tumours, indicating insufficient vector
distribution and very low transduction efficiency with replication-deficient
vector systems. To improve treatment efficacy, the use of replication-competent
oncolytic vectors in combination with new or improved prodrug-suicide gene
systems as a part of a multimodal approach is warranted. In the context of
replication-competent vectors, suicide genes might also be used as fail-safe
genes in the case of runaway infection.
PMID- 10680857
TI - PET in drug discovery and development: an introduction.
PMID- 10680858
TI - Drug development, radiolabelled drugs and PET.
AB - Positron emission tomography (PET) provides noninvasive in vivo quantitative
pharmacokinetic and pharmacodynamic information on novel and established drugs.
Because only very low amounts of the (potential) drug have to be administered,
far below toxicity levels, human studies can be carried out even before the drug
is entered in phase I studies. Such studies can provide cost-effective predictive
toxicology data and information on the metabolism and mode of action of drugs.
PET is also very useful in the study of the metabolic consequences of gene
expression or gene defects. In the last decade, several models using genetically
engineered small animals have been developed. The study of these animals with
high-resolution small animal PET cameras provides new opportunities in drug
development. Especially valuable is the contribution of PET in bridging the gap
between molecular biology, basic pathology and the design of a new generation of
drugs.
PMID- 10680859
TI - Ligand-receptor interactions as studied by PET: implications for drug
development.
AB - Positron emission tomography (PET) is a quantitative imaging method that can be
used to characterize binding properties of specific target molecules such as
various receptors, transporter molecules and enzymes in vivo. Although already
applied successfully, one of the greatest challenges for the technique is to
understand better the in vivo complexities of ligand-receptor (target)
interaction. The PET technique can be used efficiently in animal studies but,
most importantly, also in human studies. PET imaging of patients and healthy
volunteers can generate information on human pathophysiology at a molecular level
currently unobtainable with other methods. Modern imaging techniques are
increasingly applied to drug discovery and development. There are many ways of
utilizing PET in pharmacodynamic studies, one interesting approach being the
indirect exploration of synaptic neurotransmission with receptor ligands. The
receptor occupancy-type studies with PET are rapidly becoming a state-of-the-art
method for verifying the mechanism of action of a given drug in man and
especially for facilitating the dose-finding procedures in early drug
development. Thus far, PET has been mainly applied to pharmacodynamic studies in
the central nervous system but will be used also in other areas of drug
development such as cardiovascular diseases and oncology.
PMID- 10680860
TI - Drug development for neurodegenerative diseases: role of PET.
AB - There are few relevant animal models for neurodegenerative diseases to be used
for human drug development. Most current drugs for neurodegenerative diseases act
through different neurotransmitter systems. Positron emission tomography (PET) is
a unique tool in the study of neurodegenerative diseases as it enables
quantitative measurements of oxygen consumption, blood flow, energy metabolism
and functioning of various neurotransmitter systems. There are several
possibilities in the use of PET in drug development. It is possible to radiolabel
the drug itself or to study the effect of an unlabelled drug on blood flow,
energy metabolism or function of neurotransmitter systems. All these approaches
have been used in drug development for neurodegenerative diseases. However, in
spite of the important role of PET in pathophysiological studies of
neurodegenerative diseases, thus far the versatile possibilities of PET in drug
development for neurodegenerative diseases have not been fully exploited.
PMID- 10680861
TI - PET as a cardiovascular and metabolic research tool.
AB - Positron emission tomography (PET) represents the most advanced scintigraphic
imaging technology. It can be employed for cardiovascular research as well as for
clinical applications in patients with various cardiovascular diseases. PET
allows the noninvasive functional assessment of myocardial perfusion, substrate
metabolism and cardiac innervation as well as the study of skeletal muscle
metabolism and perfusion in vivo. The large number of existing tracers and the
flexibility of the PET technique that allows it to be combined with many other
methods, such as the insulin clamp technique, increase its potential as a
research tool. In the detection of myocardial viability PET is regarded as the
golden standard, and it is the only method available for the quantitative
assessment of myocardial blood flow.
PMID- 10680862
TI - Temporal lobe injury in temporal bone fractures.
AB - OBJECTIVE: To determine the incidence of intracranial injury, specifically in the
temporal lobe, in patients with longitudinal fractures of the temporal bone.
DESIGN: Prospective inception cohort. SETTING: University of Maryland Division of
Otolaryngology-Head and Neck Surgery and the Maryland Shock Trauma Center,
Baltimore. PATIENTS: Twenty-seven consecutive patients with unilateral or
bilateral temporal bone fractures. MAIN OUTCOME MEASURES: Evaluation of temporal
bone and intracranial trauma using computed tomography (CT) and magnetic
resonance imaging (MRI). RESULTS: Of the 27 patients enrolled in the study, 12
had the complete battery of MRI, CT, and physical and audiological examinations.
In all 12 patients, MRI demonstrated adjacent middle cranial fossa meningeal
enhancement. Results of non-contrast-enhanced CT and MRI demonstrated ipsilateral
temporal lobe contusions in 6 of the 13 fractures for an overall incidence of
46%. In addition, MRI demonstrated 4 cerebral contusions not seen in the results
of non-contrast-enhanced CT. CONCLUSIONS: While high-resolution CT remains the
criterion standard for evaluation of temporal bone fractures, MRI revealed a
higher incidence of related temporal lobe injuries. Magnetic resonance imaging
data may be valuable in preoperative evaluation of patients who require surgical
intervention through a middle cranial fossa approach to document pre-existing
injury and potential morbidity before retraction of the middle cranial fossa dura
mater and temporal lobe.
PMID- 10680863
TI - Dehiscence or thinning of bone overlying the superior semicircular canal in a
temporal bone survey.
AB - OBJECTIVE: To determine the incidence and etiology of dehiscences of bone
overlying the superior semicircular canal in a temporal bone archive. DESIGN: A
microscopic study was performed of 1000 temporal bones from 596 adults in a
university hospital registry. Specimens were sectioned vertically in the plane of
the superior semicircular canal. Measurements of minimum bone thickness over the
superior canal were made in a subset of 108 randomly chosen specimens. All bones
were examined for thinning or dehiscence relative to these norms. Clinical
histories, when available, were reviewed. RESULTS: Complete dehiscence of the
superior canal was identified in 5 specimens (0.5%), at the middle fossa floor (n
= 1) and where the superior petrosal sinus was in contact with the canal (n = 4).
In 14 other specimens (1.4%), the bone at the middle fossa floor (n = 8) or
superior petrosal sinus (n = 6) was no thicker than 0.1 mm, significantly less
than values measured in the control specimens (P<.001). Abnormalities were
typically bilateral. Specimens from infants demonstrated uniformly thin bone over
the superior canal in the middle fossa at birth, with gradual thickening until 3
years of age. CONCLUSIONS: Dehiscence of bone overlying the superior canal
occurred in approximately 0.5% of temporal bone specimens (0.7% of individuals).
In an additional 1.4% of specimens (1.3% of individuals), the bone was markedly
thin (< or =0.1 mm), such that it might appear dehiscent even on ultra-high
resolution computed tomography of the temporal bone. Sites affected were in the
middle fossa floor or a deep groove for the superior petrosal sinus, often
bilaterally. These abnormalities may arise from failure of postnatal bone
development. Thin areas of bone over the superior canal may be predisposed to
disruption by trauma.
PMID- 10680864
TI - Neuroprotection due to irrigation during bipolar cautery.
AB - OBJECTIVE: To test whether irrigation during bipolar cautery confers
thermoprotection from neuronal injury. DESIGN: A rat animal model (15 rats for
each treatment group) was used to test the thermoprotective effects of irrigation
during bipolar cautery. In this model, the sciatic nerve was exposed, and a 1
second stimulus was applied using bipolar cautery forceps at 40 or 20 W placed
directly on the nerve in the presence or absence of simultaneous irrigation. The
effects of cautery were determined on the basis of clinical gait analysis by
means of the Sciatic Functional Index, temperature response, and
neuropathological findings. RESULTS: The degree of paresis was reduced with
irrigation. Neuropathological examination of the sciatic nerve after cautery
showed significant axonal loss (more small than large fibers) with concomitant
demyelination, which was partially inhibited by irrigation (chi2; P = .04). The
mechanism of thermoprotection by irrigation was not the result of a reduction in
the temperature spike that followed cautery, but resulted from a reduced
temperature response during the 15 seconds that followed 40- or 20-W stimulation
with bipolar cautery. CONCLUSIONS: Simultaneous irrigation and bipolar cautery
enhance temperature recovery to basal levels and protect the peripheral nerve
from the effects of cautery.
PMID- 10680865
TI - Paranasal sinus development and choanal atresia.
AB - BACKGROUND: Although the determinates of paranasal sinus development and
sinusitis are not well defined, a candidate factor is blockage of the choana.
HYPOTHESIS: Maxillary sinuses ipsilateral to unilateral choanal atresia are
comparatively small and have more evidence of sinusitis than do the contralateral
sinuses. DESIGN: Retrospective. SETTING: Children's hospitals. PATIENTS: Sixteen
nonsyndomic children with isolated unilateral congenital choanal atresia. MAIN
OUTCOME MEASURES: Determination of maxillary sinus volumes and mucoperiosteal
thickening on preoperative computed tomograms. RESULTS: Maxillary sinuses
ipsilateral to unilateral choanal atresia have slightly larger volumes than, and
mucoperiosteal thickening that is similar to, the contralateral sinuses.
CONCLUSION: These data suggest that maxillary sinus development and sinusitis are
independent of posterior nasal ventilation and drainage.
PMID- 10680866
TI - Adenotonsillar enlargement in pediatric patients following solid organ
transplantation.
AB - OBJECTIVE: To evaluate the management of adenotonsillar hypertrophy in pediatric
patients after transplantation. DESIGN: A retrospective medical record review
after transplantation of all pediatric patients undergoing adenotonsillectomy at
the University of California, Los Angeles, Medical Center during a 14-month
period. SETTING: A tertiary care center. PATIENTS: There were 16 patients in our
review, 11 boys and 5 girls. Nine patients had undergone liver transplantation,
and 7 had undergone kidney transplantation. INTERVENTION: Fourteen patients
underwent adenotonsillectomy, and 2 underwent adenoidectomy alone. Indications
for surgical intervention included progressive symptoms of upper airway
obstruction, recurrent tonsillitis, and/or evidence of notable adenotonsillar
enlargement on physical examination. RESULTS: The mean +/- SD age at the time of
transplantation was 3 years 1 month +/- 3 years 5 months. The mean +/- SD
duration from allograft transplantation to adenotonsillectomy was 5 years 1 month
+/- 2 years 4 months. Histopathologic examination revealed that 1 kidney
transplant recipient had posttransplantation lymphoproliferative disorder. Eleven
patients were found to have Epstein-Barr virus-related lymphoid hyperplasia. All
patients experienced clinical resolution of their symptoms after surgery.
CONCLUSIONS: Posttransplantation lymphoproliferative disorder is a condition
associated with the Epstein-Barr virus infection in the setting of
immunosuppression. Early presentation of posttransplantation lymphoproliferative
disorder in children may be manifested by adenotonsillar enlargement. In addition
to the role in relieving upper airway obstruction and decreasing upper
respiratory tract infection, adenotonsillectomy may be critical in the prompt
evaluation and treatment of posttransplantation lymphoproliferative disorder.
PMID- 10680867
TI - Treatment of chronic suppurative otitis media with topical tobramycin and
dexamethasone.
AB - OBJECTIVES: To investigate the safety and efficacy of a topical combination of
tobramycin and dexamethasone in a primate model of chronic suppurative otitis
media (CSOM) and to explore the contribution of the added topical steroid for the
treatment of CSOM. DESIGN: Blinded, randomized, placebo-controlled trial.
SUBJECTS: Sixty juvenile cynomolgus monkeys randomized into the following 6
treatment groups of 10 monkeys each: 0.3% tobramycin (group 1), combined 0.3%
tobramycin-0.1% dexamethasone (group 2), combined 1.0% tobramycin-0.33%
dexamethasone (group 3), 0.1% dexamethasone (group 4), vehicle (group 5), and
phosphate-buffered saline solution (group 6). INTERVENTIONS: Chronic suppurative
otitis media was established by inoculating the right ear with Pseudomonas
aeruginosa. After 4 weeks of drainage, animals were treated according to the
group assignment with 3 drops twice daily for 7 weeks. Hearing thresholds were
monitored with repeated auditory brainstem response testing (ABR), and clinical
response was monitored with repeated otoscopic examinations and cultures
throughout the study. Cytocochleograms were evaluated for quantification of outer
hair cell loss. RESULTS: Rapid resolution of otorrhea and eradication of P
aeruginosa occurred in all groups receiving tobramycin. The inclusion of
dexamethasone accelerated the resolution of otorrhea and negative yields of
cultures compared with tobramycin alone. Otorrhea and positive culture findings
persisted in the groups not treated with topical antibiotic. Results of ABRs at 4
and 8 weeks and cytocochleograms for outer cell hair loss were not affected by
drug administration. Perilymph samples collected at the end of the study showed
no detectable tobramycin. CONCLUSIONS: Combined tobramycin-dexamethasone ear
drops were safe and effective in the monkey CSOM model. Dexamethasone enhanced
the efficacy of tobramycin.
PMID- 10680868
TI - Aerobic and anaerobic bacteriology of concurrent chronic otitis media with
effusion and chronic sinusitis in children.
AB - OBJECTIVE: To correlate the aerobic and anaerobic microbiologic findings of
concurrent chronic otitis media with effusion and chronic maxillary sinusitis.
METHODS: Cultures were obtained from 32 children with concurrent chronic otitis
media with effusion and maxillary sinusitis who underwent tympanostomy tube
placement. RESULTS: A total of 42 isolates, 24 aerobic and 18 anaerobic, were
recovered from 30 patients; 27 were isolated from both sites, 4 from the ear
only, and 11 from the sinus only. The most common isolates were Haemophilus
influenzae (9 isolates), Streptococcus pneumoniae (n = 7), Prevotella species (n
= 8), and Peptostreptococcus species (n = 6). Microbiological concordance between
the ear and sinus was found in 22 (69%) of culture-positive patients. CONCLUSION:
The concordance in recovery of organisms in more than two thirds of the patients
illustrates the common bacterial etiology between chronic otitis media with
effusion and chronic sinusitis in children.
PMID- 10680869
TI - Pediatric parotid masses.
AB - OBJECTIVE: To evaluate the incidence, types, and treatment outcomes of pediatric
parotid lesions. DESIGN: Retrospective case review, histological tissue review,
and literature review. SETTING: Tertiary care center. PATIENTS: All patients aged
18 years and younger with parotid masses evaluated and treated at the Mayo
Clinic, Rochester, Minn, from January 1, 1970, to December 31, 1997. RESULTS:
Parotid masses were identified in 118 children (60 boys and 58 girls). At
diagnosis, the ages of patients were from birth through 18 years, and 72 (61.0%)
were aged 10 years and older. An asymptomatic mass was the most common
presentation. Forty-three patients (36.4%) had infectious or inflammatory
lesions, 56 (47.5%) had benign lesions, and 19 (16.1%) had malignant lesions. The
most common benign lesions were pleomorphic adenoma (22.9%) and hemangioma
(10.2%). The most common malignant lesions were mucoepidermoid carcinoma (6.8%)
and acinic cell carcinoma (3.4%). The most common treatment was total
parotidectomy (40.7%). Surgical complications included temporary facial nerve
weakness in 22 (18.6%) patients, permanent facial weakness in 11 (9.3%), and
permanent paralysis in 2 (1.7%). Pleomorphic adenoma recurred in 4 (14.8%) of 28
patients and mucoepidermoid carcinoma in 3 (37.5%) of 8 patients. One patient
with adenoid cystic carcinoma died of the tumor. CONCLUSIONS: Although pediatric
parotid masses are unusual, they can represent a variety of pathological
diagnoses, including malignancy. We advocate prompt evaluation and treatment of
these masses, and suggest guidelines for their management, based on diagnosis.
PMID- 10680870
TI - Oropharyngotonsillitis associated with nonprimary Epstein-Barr virus infection.
AB - OBJECTIVE: To identify distinct clinical features of pharyngotonsillitis or
oropharyngitis associated with Epstein-Barr virus (EBV) infection from herpes
simplex virus infection. DESIGN: Clinical studies by case exploration. SETTING:
Institutional practice at a university hospital. PATIENTS: Thirty-three patients
with pharyngotonsillitis and 4 patients with oropharyngitis of nonbacterial
infection underwent biopsy of pharyngotonsillar lesions. MAIN OUTCOME MEASURE:
The specimens were examined by histopathology, immunohistochemistry, in situ
hybridization, and polymerase chain reaction. In addition to serological testing
and routine laboratory data, photographic oropharyngeal findings were collected
for clinical evaluation. RESULTS: In situ hybridization to detect EBV-encoded
small nuclear RNA-1 and -2 disclosed 8 cases of pharyngotonsillitis and 4 cases
of oropharyngitis associated with EBV infection. Immunohistochemical analysis
identified 5 cases of pharyngotonsillitis associated with herpes simplex virus
infection. Serological examination showed that, among 12 cases positive by in
situ hybridization, 3 cases were primary infection with infectious mononucleosis
and 9 were nonprimary infection. The staining pattern of in situ hybridization
was different, ie, a linear pattern in cases of nonprimary infection and a
scattered pattern in cases of primary infection. The clinical manifestations of
EBV pharyngotonsillitis were distinct from those of herpes simplex virus
pharyngotonsillitis and were characteristic irrespective of infectious status,
while those of EBV oropharyngitis were more variable. CONCLUSIONS: Epstein-Barr
virus-associated pharyngotonsillitis was demonstrated in patients with nonprimary
infection unaccompanied by infectious mononucleosis. Epstein-Barr virus should be
considered a potential causative agent of oropharyngotonsillitis even in absence
of infectious mononucleosis, especially in a young adult.
PMID- 10680871
TI - Novel cell proliferation marker for identification of a growth center in the
developing human cricoid.
AB - BACKGROUND: Developmental histomorphology of the human cricoid cartilage has
never been well described. Regional growth centers in the cricoid have been
hypothesized, but have never been demonstrated in histological sections.
OBJECTIVES: To apply Mib-1 immunostaining, a monoclonal antibody directed at a
nuclear proliferation marker, in human cricoids to identify a growth center and
to study the changing histomorphology of the developing cricoid. DESIGN:
Immunohistochemical Mib-1 studies were performed on postmortem cricoid sections
of 2 fetuses (gestational age, 18.5 and 33 weeks), 1 newborn (full term, 41
weeks), and 3 children (aged 1, 4, and 13 years, respectively). Cell counts,
surface areas, and organizational patterns of the chondrocytes were studied and
described in hemotoxylin-eosin-stained sections. RESULTS: Differential Mib-1
staining was found. The 18.5-week fetus showed diffuse cell proliferation
throughout the cricoid. The cricoid sections of the 33-week fetus and 1-year-old
child revealed a distinct ring of proliferation in the outer third of the cricoid
ring. The 4- and 13-year-old exhibited no cell proliferation.
Histomorphologically, with increasing age came chondrocyte hypertrophy,
decreasing cell count per standard square, and increasing organization from a
scattered to radial columnar pattern. CONCLUSIONS: Growth of the cricoid involves
a diffuse pattern of cell proliferation throughout the cricoid in fetal tissue.
At term and until age 1 year, the region of proliferation is more restricted to
the outer subperichondrial surface. By age 4 years, cell proliferation has
stopped. Histomorphologic changes in the developing cricoid include decreasing
cell counts per standard unit area, but increasing surface area with age. The
aging chondrocytes develop an increasingly organized layout to form a radially
arranged columnar pattern similar to that in the growth plate of the developing
limb bud.
PMID- 10680872
TI - Thirty-four patients with carcinoma of the cervical esophagus treated with
chemoradiation therapy.
AB - OBJECTIVE: To review the experience of 2 institutions in the management of
localized carcinoma of the cervical esophagus with chemoradiation therapy.
DESIGN: A series of 34 patients received chemoradiation therapy for a 5-year
period. All patients were treated with curative intent. Three different regimens
were used, all involving concomitant chemotherapy and high-dose radiation
therapy. Data relating to toxic effects, local control of disease, and disease
free and overall survival were prospectively collected. SETTING: Two combined
clinics at separate major hospitals where multidisciplinary care is the standard
practice for this disease. PATIENTS: Patients with biopsy-proved carcinoma of the
cervical esophagus. INTERVENTIONS: Patients received 3 different chemotherapy
regimens. Two of the regimens used a combination of cisplatin and fluorouracil.
The high-dose cisplatin regimen was a large dose of cisplatin (80 mg/m2) given on
days 1 and 22 followed by a 96-hour infusion of fluorouracil (800 mg/m2) from
days 2 to 5 and from days 23 to 26. The low-dose cisplatin regimen was cisplatin,
20 mg/m2, from days 1 to 5 and from days 22 to 26 and the same 96-hour infusion
of fluorouracil. The third regimen used fluorouracil alone. The mean radiation
dose administered was 61.2 Gy in 29.6 fractions during 41.8 days using 4- or 6-mV
photons and a shrinking field technique. RESULTS: The results of treatment have
shown a high rate of local control, although some patients developed metastases.
The local complete response rate following treatment was 91%, and the rate of
local control of disease was 88%. The projected actuarial 5-year survival rate
was 55%. Death from other causes was common. The acute toxic effects of the
treatment were acceptable, with only 5 patients requiring nasogastric feeding or
gavage. Two patients died of complications related to strictures. CONCLUSION:
Concomitant chemoradiation therapy, should be the treatment of choice for
carcinoma of the cervical esophagus.
PMID- 10680873
TI - Metastases to temporal bones from primary nonsystemic malignant neoplasms.
AB - OBJECTIVES: To compare histopathological and clinical findings of metastasis to
the temporal bone with previous reports and to determine the prevalence of these
metastases in patients with nonsystemic cancer. STUDY DESIGN: Retrospective.
METHODS: Autopsy records of 864 patients were screened to select those with
primary nondisseminated malignant neoplasms. These were evaluated
histopathologically for metastasis to and site of involvement within the temporal
bone, and histological characteristics of the tumor. Clinical records and autopsy
reports were reviewed for demographic data, clinical course, otologic and
vestibular manifestations, site of primary and its histological features, extent
of metastasis, and mode of spread. RESULTS: Of 212 patients with primary
nondisseminated malignant neoplasms, 47 had metastases to the temporal bone (76
temporal bones). Twenty different primary tumors had metastasized, most commonly
breast cancer. Hearing loss was the most common otologic symptom (seen in 19
patients [40%]), while 17 (36%) had no otologic or vestibular symptoms. Temporal
bone involvement was bilateral in 29 patients (62%). Most metastases to the
temporal bone demonstrated hematogenous spread in 58 temporal bones (76.7%), and
petrous apex was the most common site of metastases in 63 temporal bones (82.9%).
Temporal bone metastases were not observed in cases where the primary tumor was
adequately treated. CONCLUSIONS: In the largest series to date, we found temporal
bone metastases more frequently than previously reported. Absence of temporal
bone involvement in cases in which the primary tumor was adequately treated
stresses the need for early management of cancer. Metastatic disease must be
considered as a cause of hearing loss in patients with a history of malignant
neoplasm.
PMID- 10680874
TI - Radiation and intra-arterial cisplatin: effects on arteries and free tissue
transfer.
AB - OBJECTIVES: To determine the histopathologic effect of combined intra-arterial
cisplatin administration and hyperfractionated external beam radiation treatment
(HYPERRADPLAT) on potential recipient arteries in the neck and to analyze the
efficacy of free tissue transfer (FTT) in patients undergoing HYPERRADPLAT.
DESIGN: Cisplatin-perfused and nonperfused artery segments were harvested during
planned interval neck dissection performed 6 to 10 weeks after HYPERRADPLAT.
These segments were evaluated by light microscopy and transmission electron
microscopy. All patients undergoing FTT after HYPERRADPLAT were reviewed
retrospectively. SETTING: Academic medical center. PATIENTS AND INTERVENTION:
Eight patients undergoing HYPERRADPLAT for head and neck squamous cell carcinoma
and planned interval neck dissection were prospectively studied. All patients had
a perfused artery sampled, and 3 also had a nonperfused (control) artery sampled.
Five patients undergoing FTT after HYPERRADPLAT were retrospectively analyzed for
outcome of FTT. RESULTS: No consistent histological or ultrastructural
differences were detected between injected and noninjected arteries. Both
demonstrated intimal thickening, collagen and elastin deposition in the intimal
layer, and, occasionally, intimal smooth muscle proliferation. A smaller fraction
of the injected and noninjected arteries demonstrated smooth muscle cell
vacuolation, elastic fiber degeneration, and calcific deposits. Four of 5 FTTs in
patients undergoing HYPERRADPLAT were successful. CONCLUSIONS: The changes seen
in the injected and noninjected arteries were characteristic of ionizing
radiation. Arteries treated with HYPERRADPLAT had no observable difference from
vessels treated with radiation alone. These vessels can be used with caution as
recipient vessels for FTT. Further clinical experience is needed to establish the
expected results of FTT using these arteries.
PMID- 10680875
TI - Delayed anterior ischemic optic neuropathy after neck dissection.
AB - There are only 2 published cases of anterior ischemic optic neuropathy (AION)
occurring after neck dissection, to our knowledge. We report a case of bilateral
AION following neck dissection, discuss the differential diagnoses, and compare
the features of this case with those of previously described cases. There were
none of the previously described risk factors for the development of AION after
head and neck surgery (eg, hypotension, facial edema, or sudden massive
hemorrhage) in this case, but there was prolonged diffuse postoperative bleeding.
Also, the symptoms did not arise before the fifth postoperative day as they did
in the other cases. Prolonged, mild postoperative bleeding is a risk factor for
AION. Visual loss during the entire first postoperative week has to be regarded
as a complication of surgery, requires the exclusion of several differential
diagnoses, and must not be confounded with the patient's confusion or symptoms of
withdrawal.
PMID- 10680876
TI - Bilateral mucosa-associated lymphoid tissue lymphoma of the parotid gland.
AB - Mucosa-associated lymphoid tissue (MALT) tumors of the parotid gland are
extranodal non-Hodgkin lymphomas. Stage I and II MALT tumors are usually treated
with surgery or radiotherapy. Bilateral MALT-derived non-Hodgkin lymphoma of the
parotid glands is rare, and optimal treatment is debatable. Two patients
presented at the otorhinolaryngology department of the Friedrich-Alexander
University of Erlangen-Nuremberg, Erlangen, Germany. The treatment strategy that
was used in case 1 was also successfully used in case 2. A precise diagnosis
could not be made by either fine-needle biopsy or intraoperative frozen section
biopsy; it was achieved with open biopsy. Surgery and/or radiotherapy proved to
be effective. There was no recurrence of disease in either case. The advantages
of surgery are complete resection of the tumor and absence of xerostomia and
mucositis, which are caused by irradiation. Radiotherapy does not produce a scar
or an indentation at the parotid region, however, and results in a better
cosmetic appearance. Therefore, we recommend open biopsy with facial nerve
monitoring and subsequent irradiation in cases in which bilateral prominence of
the parotid glands and suspicion of a MALT lymphoma are both present.
PMID- 10680877
TI - Laryngeal cleft and eosinophilic gastroenteritis: report of 2 cases.
AB - Although laryngotracheoesophageal clefts are often found in association with
other well-described anomalies, we know of no previous reported association with
eosinophilic gastroenteritis, a disorder of unknown etiology characterized by
eosinophilic infiltration of the gastrointestinal tract. We treated 2 children
who had laryngeal clefts and eosinophilic gastroenteritis. Since the esophageal
inflammatory changes found in eosinophilic gastroenteritis may persist despite
aggressive therapy, management of the laryngotracheoesophageal clefts is more
complicated. The diagnosis of eosinophilic gastroenteritis should not be
overlooked in patients with laryngotracheoesophageal clefts and warrants prompt
referral to a pediatric gastroenterologist.
PMID- 10680878
TI - Using vision changes to differentiate sinonasal headache from migraine.
PMID- 10680879
TI - Visual aura: a useful diagnostic tool.
PMID- 10680880
TI - Patients with headache and visual disturbance: a differentiation between migraine
and sinonasal headache.
PMID- 10680881
TI - Quiz case 1. Cutaneous mucormycosis of the external ear.
PMID- 10680882
TI - Quiz case 2. Burkitt lymphoma (BL) of the nasopharynx.
PMID- 10680883
TI - Gastric dysplasia: the Padova international classification.
AB - A worldwide-accepted histologic, classification of the gastric carcinomatous and
precancerous lesions is a prerequisite for a consistent recording of
epidemiologic data and for both developing and evaluating primary and secondary
preventive efforts. Different nomenclatures have been proposed for gastric
precancerous lesions in eastern countries and in Japan. This article presents a
classification of gastric precancerous lesions resulting from an international
consensus conference involving pathologists of different countries. Five main
diagnostic categories are identified. To allow comparisons with the nomenclature
proposed by the Japanese Research Society for Gastric Cancer, each category was
also assigned a numeric identification: 1 = normal, 2 = indefinite for dysplasia,
3 = noninvasive neoplasia, 4 = suspicious for invasive cancer, and 5 = cancer.
The interobserver reproducibility of the histologic classification was tested in
a series of 46 cases. By collapsing benign alterations (categories 1+2) versus
noninvasive neoplasia (category 3) versus suspicious for invasive cancer and
fully appearing carcinomatous lesions (categories 4+5), the general agreement
value was 77.7%, whereas kappa coefficient was 0.63. By examining gastric
precancerous lesions from diverse populations, the authors agreed that the
gastric precancerous process is universal and the differences in nomenclatures
are merely semantics. The international Padova classification of the gastric
precancerous lesions is submitted to the attention of the international
scientific community, which is invited to test and to improve on it.
PMID- 10680884
TI - Differentiation of primary and metastatic clear cell tumors in the liver by in
situ hybridization for albumin messenger RNA.
AB - Clear cell neoplasms presenting as metastatic hepatic masses may be difficult to
differentiate histologically and immunohistochemically from hepatocellular
carcinoma (HCC) with prominent clear cell features, especially in small biopsy
specimens. In situ hybridization (ISH) for albumin messenger RNA (mRNA) has been
previously shown to be sensitive and specific for the detection of hepatocellular
differentiation, but its use for the identification of clear cell HCC has not
been previously evaluated. Among 309 cases of hepatocellular carcinoma diagnosed
at Mayo Clinic between 1985 and 1998, 30 cases (9.7%) with at least 30% (range,
30%-90%; median 60%) clear cells were studied by ISH for albumin mRNA. In
addition, immunohistochemical expression of AFP and polyclonal CEA, serum
determination of AFP, and histopathologic analyses of the tumor were done. Forty
two clear cell tumors were used as a control group: 21 metastatic clear cell
tumors to the liver (14 renal cell carcinomas and 7 adrenal cortical carcinomas)
and 21 primary clear cell tumors of the retroperitoneum (10 renal cell
carcinomas, 5 adrenal cortical adenomas, 4 adrenal cortical carcinomas, and 2
ovarian carcinomas). ISH for albumin mRNA was reactive in 28 of 30 cases of clear
cell HCC (93%). Clear cell HCC expressed AFP (15 cases; 50%) and polyclonal CEA
(19 cases; 63%). Tumors expressed either AFP or polyclonal CEA in 23 cases (77%).
Elevated serum AFP was present in 24 of 26 cases (92%). These results indicate
that ISH for albumin mRNA is a useful method to distinguish clear cell HCC from
other clear cell carcinomas metastatic to the liver and clear cell neoplasms in
the retroperitoneum.
PMID- 10680885
TI - Relationship and significance of greatest percentage of tumor and perineural
invasion on needle biopsy in prostatic adenocarcinoma.
AB - Serum prostate-specific antigen (PSA) levels and the biopsy Gleason sum are used
along with clinical staging to predict prostatectomy pathology results for men
with localized prostate cancer. The additional predictive value of perineural
invasion (PNI) in pretreatment prostate needle biopsies for evaluating tumor
stage in this setting is controversial. The current study evaluates the
independent predictive value of PNI for tumor staging in a cohort of 632 men who
underwent radical retropubic prostatectomies for clinically localized
adenocarcinoma of the prostate between the years 1994 and 1998. None of these men
received hormonal or radiation therapy before surgery. In addition to the Gleason
sum, biopsy results contained detailed information regarding tumor burden: 1)
total number of biopsy cores involved by adenocarcinoma, 2) greatest percentage
of any single biopsy involved by prostate carcinoma (GPC), and 3) total
percentage of cancer added over all cores (TPC). The presence or absence of any
PNI was recorded. Pretreatment factors were analyzed in a univariate and
multivariate fashion to determine their predictive value using the TNM tumor
stage (pT2 vs pT3) and the modified tumor staging system, which includes surgical
margin status (pT2 vs pT3 or positive surgical margin) as end points. Univariate
analysis revealed a significant association between pT3 disease and several
preoperative factors including age, Gleason sum, serum PSA, digital rectal
examination, PNI, GPC, TPC, and the total number of positive cores (p <0.01).
Multivariate analysis indicated that serum PSA, Gleason sum, age, and GPC
contributed significantly to predicting pT3 disease with odds ratios of 2.7 (95%
CI, 1.7-4.3), 2.3 (95% CI, 1.7-3.1), 1.7 (95% CI, 1.1-2.7), and 1.7 (95% CI, 1.4
2.1) respectively. PNI was significant in multivariate analysis only when GPC and
TPC were not considered, due to a significant interaction between GPC and PNI (p
<0.0001, Wilcoxon's rank sum test). These predictive factors showed a similar
relationship to adverse pathology when an alternative definition of adverse
pathology was used that included positive surgical margins (pT3 or any positive
margin). In the interaction between GPC and PNI, GPC was more significant than
PNI in predicting pT3 disease. However, PNI added additional information when
adverse pathology was defined more broadly as pT3 or any positive margin.
PMID- 10680886
TI - Epithelial sheath neuroma: a new entity.
AB - The authors describe four examples of a peculiar cutaneous lesion characterized
histopathologically by a proliferation of enlarged nerve fibers ensheathed by
squamous epithelium involving the superficial dermis. The perineural epithelial
sheaths were composed of uniform squamous epithelium with evidence of
cornification in the form of dyskeratotic cells or resulting in orthokeratotic
basket-weave corneocytes. Immunohistochemical studies confirmed the epithelial
and neural nature of the two components of the lesions, with the nerve fibers
expressing immunoreactivity for S-100 protein, neurofilaments, CD57, and nerve
growth factor receptor, whereas the perineural epithelial sheaths showed
immunoreactivity for cytokeratins. The authors propose the term "epithelial
sheath neuroma" for this lesion and believe that it is a distinct and a
previously undescribed benign neoplasm of both cutaneous nerves and epithelial
elements.
PMID- 10680887
TI - Large, central acellular zones indicating myoepithelial tumor differentiation in
high-grade invasive ductal carcinomas as markers of predisposition to lung and
brain metastases.
AB - High-grade invasive ductal carcinomas (IDCs) of the breast with large, central
acellular zones on their cut surfaces are usually associated with the
myoepithelial immunophenotype of carcinoma cells, which includes the expression
of S-100 protein, alpha-smooth muscle actin, and keratin 14. To clarify the
clinical significance of these features of IDCs, the authors compared the
incidence of the myoepithelial immunophenotype immunohistochemically, patient
prognosis, and metastatic sites of the tumor between 20 high-grade IDCs with
large, central acellular zones and 40 control high-grade IDCs without these
zones. The myoepithelial immunophenotype was detected in 16 IDCs (80%) with
large, central acellular zones but in only seven IDCs (18%) without. The risk
ratio of metastasis, especially in the brain and lung, and death from cancer were
significantly higher (p = 0.0096 and p = 0.030) for the 20 IDCs with large,
central acellular zones than for those without by Cox's univariate analysis.
Using Cox's multivariate analysis, large, central acellular zones in IDCs were an
indicator of high risk of brain and lung metastases and of death by cancer
independent of nodal status and tumor size. Examination of large, central
acellular zones and myoepithelial immunophenotype in high-grade IDCs appears
helpful in predicting patient prognosis and preferential metastatic sites of the
tumors.
PMID- 10680888
TI - Use of antibodies to RCC and CD10 in the differential diagnosis of renal
neoplasms.
AB - The majority of renal neoplasms can be distinguished on the basis of histologic
examination alone; however, there are morphologic similarities between clear cell
renal carcinoma and chromophobe cell carcinoma, as well as between the
granular/eosinophilic variants of these tumors and renal oncocytoma. Only a
limited number of histochemical markers are available to aid in the differential
diagnosis of these neoplasms. Hale's colloidal iron usually yields strong,
diffuse cytoplasmic staining of chromophobe cell carcinomas whereas clear cell
carcinomas are generally negative; however, interpretation of this stain is not
always straightforward. By immunohistochemistry, vimentin is detectable in most
clear cell carcinomas and is absent from most chromophobe cell tumors and
oncocytomas, but reliance on a single antibody can be misleading. In this report
we examine the use of commercially available monoclonal antibodies to RCC and
CD10 in the differential diagnosis of common renal tumors. Eighty-five percent of
clear cell carcinomas (53 of 62) had detectable surface membrane staining for
RCC, and 94% (58 of 62) were positive for CD10. Papillary carcinomas were
likewise strongly positive for RCC and CD10 in nearly all cases (13 of 14 each).
In contrast, all 19 chromophobe cell carcinomas examined were completely negative
for surface membrane staining with both of these markers. Oncocytomas were also
negative for RCC (0 of 9), but CD10 was detectable in some cases (3 of 9). These
results suggest that the presence of surface membrane staining for RCC and CD10
may be used to confirm a diagnosis of suspected clear cell or papillary renal
carcinoma. Chromophobe cell carcinomas should be negative for both markers. The
absence of RCC staining may also be helpful in the diagnosis of renal oncocytoma.
PMID- 10680889
TI - Esophageal stromal tumors: a clinicopathologic, immunohistochemical, and
molecular genetic study of 17 cases and comparison with esophageal leiomyomas and
leiomyosarcomas.
AB - Although rare elsewhere in the gastrointestinal tract, leiomyomas (LMs) are the
most common esophageal mesenchymal neoplasms. In contrast, gastrointestinal
stromal tumors (GISTs) predominate in the stomach and intestines but have not
been documented in the esophagus. This study was undertaken to determine the
clinicopathologic features and frequency of esophageal GISTs compared with LMs
and leiomyosarcomas (LMSs) of the esophagus. A total of 68 stromal/smooth muscle
tumors from the Armed Forces Institute of Pathology and the Haartman Institute of
University of Helsinki were reclassified by current histologic and
immunohistochemical criteria. There were 17 GISTs, 48 LMs, and three LMSs. The
esophageal GISTs occurred in 12 men and five women with a median age of 63 years
(range, 49-75 years). All tumors were from the lowest third of the esophagus, and
the most common complaint was dysphagia, whereas two tumors were detected
incidentally. Histologically the tumors had an overall basophilic appearance and
showed combinations of solid, myxoid, and perivascular collarlike patterns with a
spindle cell histology in 13 patients and epithelioid histology in four patients.
All tumors were positive for CD117 and for CD34, whereas two patients were also
positive for alpha-smooth muscle actin (SMA) and three patients were positive for
desmin. One patient showed a unique immunophenotype with coexpression of CD117,
CD34, SMA, and desmin. Nine patients died of disease, including all who had a
tumor larger than 10 cm, and also one patient whose tumor showed five mitoses per
50 high-power fields. In comparison, esophageal LMs (n = 48) occurred in a
younger population (median age, 35 years) but, similar to the GIST group, men
predominated (67%). All LMs were clinically indolent tumors with no tumor-related
mortality. The LMs showed eosinophilic cytoplasm, and were positive for desmin
and SMA, and negative for CD117 and CD34. All three LMSs were large high-grade
tumors that showed muscle cell markers but no CD117. All patients died of
disease. Esophageal GISTs showed mutations in exon 11 of c-kit as described
previously in gastric and intestinal GISTs. The separation of GISTs from
esophageal LMs is important diagnostically because the former group has a high
risk of malignant behavior.
PMID- 10680890
TI - Small cell neuroendocrine carcinoma with skeletal muscle differentiation: report
of three cases.
AB - Three cases of neuroendocrine carcinoma showing skeletal muscle differentiation
are presented. The tumors were located in the skin and subcutaneous tissue, the
urinary bladder, and the nasal cavity respectively, and were composed by two cell
types admixed intimately with each other. One cell type had features identical to
those seen in conventional small cell neuroendocrine carcinoma, including scanty
cytoplasm, round nuclei with fine granular chromatin, immunohistochemical
reactivity for neuron-specific enolase, chromogranin and cytokeratins, and
electron-dense granules on ultrastructural examination. The second cell type was
either plasmacytoid or elongated and straplike, with abundant eosinophilic
cytoplasm and irregular nuclei with prominent nucleoli. These cells showed
immunohistochemical positivity for desmin, sarcomeric actin, myoglobin, and
myogenin. They also exhibited ultrastructural evidence of rhabdomyoblastic
differentiation in the form of contractile filaments with abortive Z-band
formation. An origin from a cell capable of dual differentiation toward
neuroendocrine and rhabdomyoblastic elements is postulated for these tumors.
PMID- 10680891
TI - Cellular pseudosarcomatous fibroepithelial stromal polyps of the lower female
genital tract: an underrecognized lesion often misdiagnosed as sarcoma.
AB - Fibroepithelial stromal polyps of the vulvovaginal region are benign lesions
that, when bland or hypocellular, are readily recognized. However those that
exhibit bizarre cytomorphology, atypical mitoses, or hypercellularity, raising
the possibility of malignancy, continue to be underrecognized. The authors
reviewed a series of fibroepithelial stromal polyps to characterize further the
morphologic features that can lead to a misdiagnosis of sarcoma. A total of 33 of
65 consecutive cases of fibroepithelial stromal polyps retrieved from the
authors' consultation files were remarkable for marked hypercellularity (33 of
33), marked cytologic pleomorphism (21 of 33), mitotic counts of more than 10
mitoses per 10 high-power fields (12 of 33), and the presence of atypical mitoses
(14 of 33). A total of 16 of 33 lesions had three or more of these features.
Important morphologic clues to the diagnosis (shared with usual polyps at this
site) were lack of an identifiable lesional margin, extension of abnormal stromal
tissue up to the mucosal-submucosal interface, and the frequent presence of
individually scattered multinucleate stromal cells, most often located close to
the surface epithelium. Immunohistochemically, seven of 12 cases were desmin
positive and one of 11 cases were smooth muscle actin positive. The age range of
patients was 16 to 75 years (median, 32 years), and 21 patients (64%) were
premenopausal. Sites included the vagina (18 of 33), cervix (seven of 33), and
vulva (eight of 33). A total of 14 of 33 patients were pregnant, three patients
were taking Tamoxifen, and one patient was on oral progesterone. Eight of 33
patients had multiple lesions at the time of presentation, of whom five were
pregnant. Clinical follow-up was available in 21 of 33 patients. Three of 21
patients with follow-up had local, nondestructive recurrence. Two of these
patients had multiple recurrences. None of the patients followed developed
metastases. Cytologic atypia has been a previously recognized feature in these
lesions; however, the occurrence of marked stromal cellularity and a mitotic rate
of more than 10 mitoses per 10 high-power fields have not been emphasized
previously. Moreover, the combination of these features has only rarely been
documented. Awareness of the spectrum of histologic features that these lesions
can exhibit is crucial in their accurate recognition, thus avoiding potential
overtreatment.
PMID- 10680892
TI - Independent prognostic value of peritoneal immunocytodiagnosis in endometrial
carcinoma.
AB - Among the clinical parameters that play a pivotal role in predicting the outcome
of patients with endometrial carcinoma, intraperitoneal microscopic dissemination
represents an important cause of recurrences. To date, peritoneal cytology has
been incorporated into the current surgical staging system (International
Federation of Gynecology and Obstetrics 88), although its predictive value
remains a controversial issue. In this study the authors investigated the
possibility of applying immunocytochemistry (ICC) to the diagnosis of peritoneal
washing (PW) aimed at improving conventional cytology and verifying the
prognostic value of peritoneal malignant cells. The authors analyzed 182 PWs
sampled from endometrial cancer patients. The ICC analysis was performed using
two monoclonal antibodies (MAbs)--AR-3 and B72.3--that in combination recognize
more than 95% of endometrial carcinomas. The presence of peritoneal-free cancer
cells was identified morphologically in 27 of 182 lavages (14.8%) and ICC in 50
of 182 (27.5%), with a significant improvement (p <0.0001). Five-year survival
analysis, comparing results of ICC and cytodiagnosis, demonstrated a significant
decrease of disease-free survival in patients with peritoneal microscopic
disease. Furthermore, multivariate analysis showed that ICC diagnosis of PWs is
an independent prognostic factor. Data indicate that the use of selected MAbs
allows one to identify cytologically false-negative cases, providing results that
are highly predictive of a worse clinical outcome.
PMID- 10680893
TI - Primary giant cell tumor of soft tissues: a study of 22 cases.
AB - Twenty-two cases of giant cell tumor of soft tissues (GCT-ST) identified in the
Mayo Clinic files and the consultation files of two of the authors (A.G.N.,
C.D.M.F.) were analyzed clinicopathologically. Age at presentation ranged from 5
to 80 years (median, 43 years), and there was no sex predilection (12 male, 10
female). Duration of symptoms ranged from 2 to 12 months (median, 4.5 months),
and a painless growing mass was the most common complaint. The lower limbs were
the most frequent location (50%), followed by the trunk (31.8%) and the upper
limbs (13.6%). The size of the tumors ranged from 1 to 10 cm, and they tended to
be superficial (86.4%), forming well-circumscribed (72.7%), multinodular (86.4%)
masses. Histologically, all tumors consisted of a mixture of mononuclear cells
showing vesicular, round to oval nuclei and osteoclastlike, multinucleated giant
cells distributed uniformly throughout the tumors. Foci of stromal hemorrhage
were observed in 11 tumors (50%); nine tumors (40.1%) showed metaplastic bone
formation and six (27.2%) showed aneurysmal bone cystlike areas. Necrosis was
absent in all but one tumor. Mitotic figures were present in all but one tumor,
ranging from two to more than 30 mitoses per 10 high-power fields (HPFs; median,
9.5 mitoses per 10 HPFs) and were typical in aspect. Vascular invasion was
identified in seven tumors (31.8%), and none of the tumors showed marked cellular
atypia or pleomorphism. The tumors were treated surgically, and follow-up
information was available for 16 patients (duration of follow-up, 2 to 130
months; median, 51 months). Only one of the 16 patients (6.2%) had local
recurrence and lung metastases; this patient died of the tumor. In conclusion,
GCT-ST occurs as a primary soft-tissue neoplasm and is identical clinically and
morphologically to giant cell tumor of bone. Provided that GCT-ST is treated
adequately by complete excision, a benign clinical course is expected because
episodes of distant metastasis and tumor-associated death seem to be exceedingly
rare.
PMID- 10680894
TI - The pathology of late recurrence of testicular germ cell tumors.
AB - A total of 91 men had histologically documented late recurrences of testicular
germ cell tumors characterized by a complete response to treatment with a
subsequent disease-free interval of at least 2 years and no evidence of a second
primary lesion. Ninety percent of the patients for whom information was available
received chemotherapy shortly after their initial diagnosis of testicular germ
cell tumors; most of the other patients were known to have stage I disease
initially. Overall, 60% of patients had teratoma in their late recurrences,
including 20 patients (22%) in whom teratoma was the only element. Thus, teratoma
was the most common type of neoplasm in late recurrences. Excluding teratoma
coexisting with other types of neoplasms, yolk sac tumor was the most frequent
type of tumor in patients with late recurrence. It occurred in 47% of patients,
either alone or with teratoma, another nonteratomatous germ cell tumor type, or a
"nongerm cell malignant tumor." Unusual types of yolk sac tumor, including
glandular, parietal, clear cell, and pleomorphic patterns, were seen frequently
in late recurrences and often raised differential diagnostic problems with
"nongerm cell" carcinomas. A smaller number of late recurrences consisted of
other types of neoplasms. Twenty percent of patients with late recurrence had a
nonteratomatous germ cell tumor other than yolk sac tumor, either alone, with
yolk sac tumor, or with a "nongerm cell malignant tumor." Most of these
nonteratomatous germ cell tumors other than yolk sac tumor were embryonal
carcinoma, although rarely seminoma and choriocarcinoma were encountered.
"Nongerm cell malignant tumors," including both sarcomas and carcinomas of
various types, occurred in 23% of late-recurrence patients, either alone or with
a nonteratomatous germ cell tumor. Late recurrences were seen in many different
sites in these patients, including the retroperitoneum, abdomen, pelvis, liver,
mediastinum, lung, bone (femur, vertebra, and rib), lymph nodes outside the
retroperitoneum and mediastinum (supraclavicular, neck, and axillary regions),
scrotum and inguinal regions, adrenal gland, chest wall, and buttocks. Follow-up
data were available for 79 of the 91 patients studied. Duration of follow-up
ranged from 2 months to 13 years after the patient's first late recurrences; the
mean length of follow-up was 4.8 years. Patients whose late recurrences consisted
of teratoma only had the most favorable outcomes, with 79% having no evidence of
disease at last follow-up. Patients whose late recurrences consisted of pure
"nongerm cell malignant tumor" or pure germ cell tumor (yolk sac tumor or other
types) had a much worse prognosis: Only 36% to 37% were alive with no evidence of
disease. Patients with two different types of nonteratomatous malignancies in
their late recurrences had a dismal clinical course: Only 17% with both yolk sac
tumor and other nonteratomatous germ cell tumor had no evidence of disease,
whereas no patient with both nonteratomatous germ cell tumor and "nongerm cell
malignant tumor" was disease free. Late recurrences consisting of teratoma alone
often have a favorable outcome, but the prognosis in all other patients is poor.
Furthermore, late recurrence is not likely to respond to chemotherapy and is best
treated by surgical excision when possible.
PMID- 10680895
TI - Immunohistochemically detected micrometastases in peribronchial and mediastinal
lymph nodes from patients with T1, N0, M0 pulmonary adenocarcinomas.
AB - The T1, N0, M0 subset of stage I lung adenocarcinoma is a tumor that has a 5-year
disease-free survival rate of 66% to 85%. To date, there has not been a rigorous
immunohistochemically detected lymph node micrometastasis study composed of
patients with identical stage and type of tumors, and in which standard
histologic features were incorporated into multivariate analyses. We
immunohistochemically examined the peribronchial and mediastinal lymph nodes from
80 consecutively accrued patients with T1, N0, M0 adenocarcinomas and
bronchioloalveolar carcinomas unselected for distant metastasis, and an
additional 39 patients with similar stage and type neoplasms who were selected
for their development of metastases to evaluate the prevalence of
micrometastases, their association with distant metastases, and their
relationship with other pathologic prognostic features. All slides were stained
with keratin AE1/3. Micrometastases were confirmed with Ber-Ep4. Three
immunohistochemically detected lymph node micrometastases were identified in
three of 80 consecutively accrued patients (4%). These three positive stains
constituted 0.5% of the 573 stains required to immunohistochemically screen all
of the lymph node blocks from these patients. Among the 39 patients who were
selected because they developed distant metastases, three immunohistochemically
detected lymph node micrometastases from three patients were identified, which
constituted 8% of patients in this group and 1% of the 280 stains required to
screen all of these patients' lymph nodes. Small vessel invasion, maximum tumor
dimension, and immunohistochemically detected lymph node micrometastases were
independently associated with metastases on multivariate analysis. Among patients
who developed metastases, there was no significant difference in the disease-free
survival rate between those with and those without immunohistochemically detected
lymph node micrometastases. Given the low sensitivity in terms of the number of
immunohistochemical stains performed, and the prognostic significance of standard
histologic features, the use of immunohistochemical screening lymph nodes from
all patients with T1, N0, M0 adenocarcinomas is questionable.
PMID- 10680896
TI - Prevalence of inter-institutional anatomic pathology slide review: a survey of
current practice.
AB - Multiple studies have demonstrated discrepancy rates between original and review
histopathologic diagnoses of up to 30% with a mean of approximately 10%. In view
of these rates of discrepancy, several authorities, including the Association of
Directors of Anatomic and Surgical Pathology, have recommended in-house review of
all outside materials before commencement of therapy. We used a mail survey to
determine the degree of compliance with these recommendations among pathology
groups in the United States. Mail surveys were sent to six randomly selected
hospitals from each state (300 total). The survey included demographic questions,
including surgical pathology caseload, size of hospital (beds), and type of
hospital (community-general, non-academic-tertiary care, or academic-tertiary
care). The survey asked whether the hospital required review of all outside
slides before the performance of surgery. If not, was such a policy encouraged
but not required. The survey also asked whether in-house review of outside cases
had disclosed any significant differences in pathologic diagnoses. Finally, the
survey questioned whether any discrepancies between an internal and external
surgical pathology diagnosis had been discovered following radical surgery. One
hundred twenty-six usable responses were obtained. Fifty-five of these were from
hospitals self-described as community-general, seven were from hospitals
describing themselves as non-academic-tertiary care, and the remaining 61
hospitals described themselves as academic-tertiary care institutions. Sixty
three institutions stated they had a requirement for in-house review of outside
material, with 46 of 61 academic-tertiary centers having such a requirement.
Thirty-seven of 55 community-general hospitals did not require in-house review of
outside material before surgery could be performed. One hundred ten of the 126
institutions returning surveys either encouraged or required review of outside
material. Ninety-five institutions reported that they had at least one outside
case in which their diagnosis was significantly discordant with that rendered by
the referring pathologist. Sixty (48%) of the 126 institutions reported at least
one case in which a discrepancy was found between the outside biopsy diagnosis
and the internal diagnosis rendered on material obtained by radical surgery.
Approximately half of all responding institutions have a requirement for in-house
review of outside material prior to surgery. A majority of institutions requiring
such review have found discrepancies between the in-house diagnoses and those
rendered by referring laboratories.
PMID- 10680898
TI - Ronald A. DeLellis, M.D., recipient of the 1999 Fred W. Stewart Award.
PMID- 10680897
TI - Mesotheliomas with deciduoid morphology: a morphologic spectrum and a variant not
confined to young females.
AB - Deciduoid mesotheliomas are rare with only four previously reported cases, all
affecting the peritoneum of young females. We describe another six cases (three
men and three women; age range 52-65 yrs, median 55 yrs; five peritoneal and one
pleural). Three patients had an occupational history of asbestos exposure. The
deciduoid appearance predominated in four cases, whereas in two it represented a
minor component within conventional tubulopapillary epithelioid mesothelioma. All
tumors were strongly cytokeratin-positive (including CK5/6) and all showed at
least focal staining for thrombomodulin, HBME-1, and calretinin. All were
negative for epithelial mucin (D/PAS), CEA, BerEP4, LeuM1 (CD15), CD21, CD35, and
S100 protein. Five of six cases (83%) were vimentin-positive and two (33%) were
focally positive for alpha-smooth muscle actin. A differential diagnosis of
gastrointestinal autonomic nerve tumor (GANT) had been initially considered from
the morphology of one case, and we found positivity for some of the "neuronal"
markers described in GANTs. This prompted us to apply such a panel to the other
five tumors, accepting that the cytokeratin positivity encountered in all of our
cases would exclude GANT. All cases of deciduoid mesothelioma (100%) were
positive for PGP 9.5 and NSE and four of six (66%) were positive for NKI/C3. Weak
focal staining (<5% cells) for synaptophysin was seen in two of six tumors. All
cases were chromogranin-negative. All cases examined by electron microscopy
showed desmosomes and smooth microvilli without rootlets but no neuroendocrine
granules. In conclusion, a deciduoid morphology appears to be part of the
histopathologic spectrum encountered in epithelioid mesothelioma. This variant is
not confined to female patients and occurs over a wider age range than previously
recognized. The overlapping immunophenotype with GANTs illustrates that caution
should be exercised when interpreting positivity for "neuronal" markers in this
context. An immunohistochemical panel that includes cytokeratins should always be
used.
PMID- 10680899
TI - Spontaneously relapsing clonal, mucosal cytotoxic T-cell lymphoproliferative
disorder: case report and review of the literature.
AB - Primary T-cell lymphoma of the gastrointestinal tract is a rare and usually
aggressive disorder that may be associated with celiac disease. The authors
describe a unique case of a clonal proliferation of CD8+ T cells involving the
oral mucosa, ileum, and colon of a 35-year-old man that has regressed
spontaneously and recurred numerous times over a 9-year period without treatment.
The patient's symptoms were limited to occasional rectal bleeding and recurring
painful oral ulcers. Within the intestine, these collections of small T cells
induced minimal architectural distortions and did not show extensive
epitheliotrophism. Polymerase chain reaction and sequencing analyses revealed
that the identical T-cell clone has been present for more than 9 years and in
different mucosal locations in this patient. This may represent a unique T-cell
lymphoproliferative process akin to a mucosal counterpart of lymphomatoid
papulosis of the skin.
PMID- 10680900
TI - 'Little' littoral cell angioma of the spleen.
PMID- 10680901
TI - Examining the sentinel lymph node.
PMID- 10680902
TI - Epithelial-myoepithelial carcinoma.
PMID- 10680903
TI - Epstein-Barr virus-related intravascular lymphomatosis.
PMID- 10680904
TI - Poorly differentiated thyroid carcinoma--it is important.
PMID- 10680905
TI - Adenoid basal epithelioma versus adenoid basal carcinoma.
PMID- 10680906
TI - Nodal marginal zone lymphoma.
PMID- 10680907
TI - Primary nodal marginal zone lymphomas of splenic and MALT type.
PMID- 10680908
TI - What is a neuroendocrine tumor?
PMID- 10680909
TI - Omit iodine and CD30 will shine: a simple technical procedure to demonstrate the
CD30 antigen on B5-fixed material.
PMID- 10680910
TI - 'Like--but oh, how different!'.
PMID- 10680911
TI - Lobular endocervical glandular hyperplasia represents pyloric gland metaplasia?
PMID- 10680912
TI - Lobular endocervical glandular hyperplasia represents pyloric gland metaplasia?
PMID- 10680913
TI - Cause of familial and multiple gastrointestinal autonomic nerve tumors with
hyperplasia of interstitial cells of Cajal is germline mutation of the c-kit
gene.
PMID- 10680914
TI - Controversies in the management of thyroid nodule.
AB - Few subjects in surgery have generated as much controversy as the management of
thyroid nodule. The controversial issues include classification and histology,
diagnostic evaluation including needle biopsy, indications for surgery,
management of incidentalomas of the thyroid, the role of frozen section, extent
of thyroidectomy, management of neck nodes, the role of suppressive therapy, the
use of radioactive iodine, and appropriate follow-up. The two major issues in
relation to the controversies are diagnostic workup and extent of thyroidectomy.
Whenever the issue related to extent of thyroidectomy is discussed, there are two
strong groups believing in total thyroidectomy or less than total thyroidectomy.
This has generated considerable debate and panel discussions, and this article
reviews this on-going debate.
PMID- 10680915
TI - Prevalence of herpes simplex virus in malignant laryngeal lesions.
AB - OBJECTIVE: To determine the prevalence of herpes simplex virus (HSV) in malignant
laryngeal lesions. STUDY DESIGN: Retrospective review. MATERIALS AND METHODS:
Paraffin-embedded, histologically confirmed specimens containing benign laryngeal
lesions, squamous cell carcinoma of the larynx, and squamous cell carcinoma of
the oral cavity were identified from archived surgical specimens. Biopsies of
normal-appearing oral cavity tissue were also obtained from fresh-frozen
cadavers. These tissues were analyzed for the presence of HSV DNA using
polymerase chain reaction techniques. Patient charts were reviewed for patient
demographics, risk factors, stage, clinical course, treatment, and outcome.
RESULTS: HSV was detected in nine laryngeal squamous cell carcinomas (75%) and in
none of the benign laryngeal lesions (P = .0001). HSV was also found in three
oral cavity squamous cell carcinomas (25%) and in none of the controls (P =
.049). CONCLUSION: HSV is more prevalent in squamous cell carcinoma of the larynx
and oral cavity than in their respective control groups, suggesting a role for
carcinogenesis. HSV is more prevalent in squamous cell carcinoma of the larynx
than of the oral cavity. Further studies to determine the role of HSV as a
cocarcinogen and its interrelationship with other environmental factors in
laryngeal cancer are warranted.
PMID- 10680916
TI - Sentinel lymph node radiolocalization in head and neck squamous cell carcinoma.
AB - OBJECTIVES: To determine the feasibility of sentinel node radiolocalization in
stage N0 in head and neck squamous cell carcinoma and to gain insight as to
whether the sentinel node could be prognostic of regional micrometastatic
disease. STUDY DESIGN: A prospective report on the application sentinel node
radiolocalization in eight patients with N0 squamous cell carcinoma of the head
and neck region. METHODS: For each patient a peritumoral submucosal injection of
filtered technetium (99mTc) prepared with sulfur colloid was performed
immediately following intubation. After at least 30 minutes, focal areas of
accumulation corresponding to a sentinel node were marked on the skin surface.
Complete neck dissections were performed, and the sentinel nodes were identified
for later histological evaluation and comparison to the remaining lymphadenectomy
specimen. RESULTS: Sentinel node radiolocalization accurately identified two or
more sentinel lymph nodes in all eight cases. In one patient, two of the three
lymph nodes containing micrometastatic disease were sentinel lymph nodes. There
was no instance in which sentinel node was negative for micrometastatic disease
while being positive in a nonsentinel lymph node. CONCLUSIONS: Accurate
localization of the sentinel lymph node using radiolabeled sulfur-colloid is
feasible in patients with squamous cell carcinoma of the head and neck region.
Although sentinel node radiolocalization in head and neck squamous cell cancer
may potentially reduce the time, cost, and morbidity of regional lymph node
management, more experience with technique is required before its role can be
determined.
PMID- 10680917
TI - Long-standing lateral neck mass as the initial manifestation of well
differentiated thyroid carcinoma.
AB - OBJECTIVE: To analyze the presentation, evaluation, and treatment of a subset of
patients with well-differentiated thyroid carcinoma who present with a lateral
neck mass and no palpable disease in the thyroid gland. STUDY DESIGN: A
retrospective review of all patients undergoing thyroidectomy for malignancy.
METHODS: A database of all thyroidectomies performed for malignancy by the
Vanderbilt University Department of Otolaryngology-Head and Neck Surgery from
1992 to 1997 was created. Patients who presented with an isolated neck mass
without evidence of palpable disease in the thyroid were selected for the study
population. RESULTS: There were 60 cases of thyroid malignancy, with 14 cases
(23.3%) that presented as isolated lateral neck mass. The characteristics of this
group (compared with the population of all thyroid malignancies) include younger
age at presentation (37.7 +/- 15.2 y vs. 49.8 +/- 15.6 y; Student t test: P =
.019) and long-standing presence of symptoms (27.4 +/- 39.6 mo vs. 3.6 +/- 3.9
mo; P = .023). These patients generally presented from a referring facility after
having an excisional biopsy, which was 100% accurate. Fine-needle aspiration is
becoming more useful and was 66.7% accurate. Histological examination revealed
cancer in the thyroid gland in all patients, 11 cases of papillary carcinoma, 2
follicular carcinomas, and one medullary carcinoma The mean size of the primary
focus was 10.9 +/- 8.7 mm, with 29% demonstrating bilateral disease and 14%
demonstrating multifocal disease in the ipsilateral gland. The neck specimens
revealed an average of 5.3 +/- 3.2 metastatic nodes in levels II-IV and 3.9 +/-
4.6 metastatic nodes in the paratracheal region. CONCLUSION: Based on this
patient population, the long-standing lateral neck mass in the young patient
should raise the physician's index of suspicion for thyroid carcinoma Fine-needle
aspiration should be used in conjunction with judicious excisional biopsy. The
bilateral and multifocal nature of otherwise occult primary disease argues for
total thyroidectomy in this setting.
PMID- 10680918
TI - Length of stay after free flap reconstruction of the head and neck.
AB - OBJECTIVES: To analyze the incidence and timing of postoperative complications
after free tissue transfer (FTT) and relate that to length of stay (LOS.) STUDY
DESIGN: We reviewed one surgeon's experience with 97 patients undergoing 100 head
and neck reconstructions via FTT for a variety of traumatic and ablative defects
METHODS: Charts were reviewed for demographic data, type of defect and flap,
complications, LOS, length of intensive care unit (ICU) stay, date of
decannulation, and first oral intake, any readmission to the hospital, and
preoperative radiation status. RESULTS: Using strict guidelines, 31% of patients
had some form of complication, including a 9% flap failure rate. Average
postoperative LOS for all patients was 11 days. Average LOS for uncomplicated
cases was 9 and for complicated cases was 16 days. For cases with flap-related
complications the average LOS rose to 20 days. All reconstructive failures
(defined as patients requiring subsequent surgical procedures after a flap
related complication, regardless of outcome) occurred within the first 7
postoperative days. Three patients were readmitted for various reasons: a partial
flap dehiscence (postoperative day [POD] 9), meningitis (POD 24), and
orocutaneous fistula (POD 22), for a 3.2% readmission rate. Fourteen percent of
patients were on a regimen of oral intake, and 13% had decannulation by the time
of discharge. Resumption of oral intake and tracheostomy decannulation were
accomplished on an outpatient basis in the remainder of patients. CONCLUSIONS:
There were no preventable complications associated with early hospital discharge,
nor was there evidence of adverse patient outcome. We conclude that early
hospital discharge is feasible after FTT reconstruction and is consistent with
quality care.
PMID- 10680919
TI - Radiation dose to otologic structures during head and neck cancer radiation
therapy.
AB - BACKGROUND: Otologic structures are often contained within head and neck cancer
radiation treatment ports. The dosimetry to otologic structures has not been
routinely analyzed and radiation treatment planning does not currently attempt to
specifically avoid the inner ear structures when dosimetry is calculated. Recent
studies demonstrate that up to 30% of patients experience sensorineural hearing
loss on multimodality therapy with cisplatin and radiation. METHODS: In the
current case series, radiation dosimetry to otologic structures was calculated
from computed tomogram treatment plans on patients. Fifteen nasopharyngeal, oral
cavity, oropharyngeal, and hypopharyngeal cancer patients were analyzed. RESULTS:
Between 8% and 102% of the total dose is delivered to the petrous bone/cochlea,
with 4 of 15 patients getting more than 50% of the dose to at least one cochlea
The mastoid air cells received between 3% and 75% of the total dose, with higher
doses being delivered to patients with bulky high neck metastases or
nasopharyngeal tumors. The eustachian tubes received between 20% and 102% of the
total dose, with 10 of 15 patients receiving more than 50% of the dose to this
anatomic site. CONCLUSION: We conclude that the cochlea and eustachian tubes
receive significant radiation during treatment, particularly in nasopharyngeal
cancer patients. Careful design of radiation treatment ports may allow for the
reduction of radiation to hearing structures.
PMID- 10680920
TI - Quantification of the learning curve for percutaneous dilatational tracheotomy.
AB - OBJECTIVES/HYPOTHESIS: Although numerous investigators have reported a bedside
percutaneous dilatational tracheotomy (PDT) complication incidence similar to
that of standard operative tracheostomy, others have proposed a "learning curve"
for PDT resulting in increased complications early in individual or institutional
experience with this procedure. The objective of this investigation is to
characterize and quantify the proposed learning curve for PDT. STUDY DESIGN:
Prospective analysis of complication incidence for the first 100 PDT procedures
performed in a local community hospital Department of General Surgery. METHODS:
Demographic data, patient disease variables, and patient anatomic features, as
well as perioperative, postoperative, and late complications, were recorded
prospectively. Patients were divided into sequential cohorts of 20 and were
evaluated for complications at regular intervals. RESULTS: Perioperative and late
complication incidence was significantly higher in the first 20 patients who
underwent PDT. However, postoperative complication incidence did not
significantly vary with operator or institutional experience. In addition,
patients with suboptimal anatomy were found to have a significantly increased
complication incidence, independent of operator and institutional experience.
CONCLUSIONS: Percutaneous dilational tracheotomy has an identifiable learning
curve that is most prominent in the first 20 patients treated. Early experience
with PDT should be obtained under controlled circumstances, ideally the operating
suite. Although most complications occur during acquisition of early experience
with PDT, certain life-threatening complications such as tube dislodgment or
inability to complete procedure may occur even after extensive experience is
obtained. Bedside PDT has an acceptable complication incidence, but any surgeon
employing this technique must be prepared to perform immediate standard open
tracheotomy to minimize potentially lethal complications of this elective
procedure.
PMID- 10680921
TI - Documentation of variations in sinonasal anatomy by intraoperative nasal
endoscopy.
AB - OBJECTIVES: Functional endoscopic sinus surgery (FESS) requires a thorough
understanding of the variability in sinonasal anatomy. Previous reports have
relied primarily on anatomic studies of cadaveric specimens or skulls, or on
radiographic analysis. Relatively few comparative anatomic data have been
accumulated with endoscopic examination of living patients. STUDY DESIGN:
Retrospective review of video recordings of 119 consecutive patients undergoing
intraoperative nasal endoscopy at the time of sinonasal surgery. METHODS: At the
beginning of each surgical procedure, endoscopic examination of the nasal
cavities was performed with 0 degrees and 30 degrees telescopes and recorded with
a three-chip video camera on 3/4-inch U-matic videotape. These video records were
then reviewed with attention to variations in anatomical configuration of
different sinonasal structures. RESULTS: Data demonstrating variations in the
anatomical configuration of the following structures of the lateral nasal wall
are presented. Middle turbinate: typical (63%), concha bullosa (15%), sagittal
cleft (6%), laterally displaced (4%), "L" shaped (3%), medially bent (3%),
laterally bent (3%), medially displaced (2%), and transverse cleft (0.5%).
Uncinate process: typical (85%) and medially rotated (15%). Ethmoid bulla:
typical or balloon (45%), sausage-shaped (34%), and flat (21%). Accessory ostium:
round (50%), oval (46%), and kidney-shaped (4%). Sphenoid sinus ostium: oval
(42%), slit (32%), and round (26%). The classification system for the anatomical
categories is illustrated with digitized images. CONCLUSIONS: This study attempts
to provide statistical data regarding variations in sinonasal anatomy in living
subjects. Familiarity with such anatomy is important in differentiating normal
variants from pathological conditions to optimize surgical treatment of sinus
disease, while avoiding complications.
PMID- 10680922
TI - Update on intratympanic gentamicin for Meniere's disease.
AB - OBJECTIVE: To review the literature relating to intratympanic gentamicin
injection therapy for Meniere's disease to detect consistencies and differences
that might suggest optimal technique. DESIGN: Retrospective literature review.
METHODS: Eighteen papers from the literature regarding clinical experience with
intratympanic gentamicin injections for treatment of Meniere's disease were
reviewed and tabulated. RESULTS: All papers reported high success rates in
treating episodic vertigo of Meniere's disease, but technique, dose, duration,
and treatment philosophy varied considerably. Hearing loss was typically reported
in about 30% of patients. CONCLUSION: No single technique of gentamicin injection
has a significant medical advantage over the others. Until controlled studies
indicate otherwise, nonmedical needs such as convenience and safety may be
considered when choosing a technique.
PMID- 10680923
TI - Redefining the survival of the fittest: communication disorders in the 21st
century.
AB - OBJECTIVES: To determine the economic effect on the US economy of the cost of
caring for people with communication disorders as well as the cost of lost or
degraded employment opportunities for people with such disorders, including
disorders of hearing, voice, speech, and language. STUDY DESIGN: Survey of
available historical and contemporary governmental and scholarly data concerning
work force distribution and the epidemiology of disorders of hearing, voice,
speech, and language. METHOD: Analysis of epidemiological and economic data for
industrialized countries, North America, and the United States. RESULTS:
Communication disorders are estimated to have a prevalence of 5% to 10%. People
with communication disorders may be more economically disadvantaged than those
with less severe disabilities The data suggest that people with severe speech
disabilities are more often found to be unemployed or in a lower economic class
than people with hearing loss or other disabilities. Communication disorders may
cost the United States from $154 billion to $186 billion per year, which is equal
to 2.5% to 3% of the Gross National Product. CONCLUSIONS: Communication disorders
reduce the economic output of the United States, whose economy has become
dependent on communication-based employment. This trend will increase during the
next century. The economic cost and the prevalence rates of communication
disorders in the United States indicate that they will be a major public health
challenge for the 21st century.
PMID- 10680924
TI - Saline irrigation in the prevention of otorrhea after tympanostomy tube
placement.
AB - OBJECTIVES: Comparison of intraoperative saline irrigation to otic drops in the
prevention of postoperative otorrhea in children with middle ear effusion
undergoing bilateral myringotomy with ventilation tubes. STUDY DESIGN: This study
was designed as a blinded, controlled, prospectively randomized trial. METHODS:
Study children were randomly assigned to receive either otic drops for 3 days
postoperatively or saline irrigation of the middle ear space at the time of
myringotomy. Only children with effusion present at the time of surgery were
included. All children were evaluated for drainage 7 to 14 days postoperatively,
and the degree of drainage was graded from 0 to 4. RESULTS: Of the 84 patients
entered into the study, 62 patients were eligible for data analysis (16 failed
follow-up, 6 records were lost). Of the patients who completed the study, not all
had bilateral effusions, resulting in 111 ears for inclusion in the study. Fifty
two ears underwent irrigation, and 10 were noted to have otorrhea (19.2%). Fifty
nine ears received otic drops, resulting in 21 ears with otorrhea (35.6%).
Evaluating the degree of otorrhea with a five-point Leichert scale, the average
score per ear was 0.42 for the saline irrigation group and 1.07 for the control
group. The rate and degree of drainage were both statistically reduced in the
saline irrigation group (P < .05). CONCLUSIONS: Using middle ear irrigation at
the time of tympanostomy may be more effective than antibiotic drops in
preventing postoperative otorrhea.
PMID- 10680925
TI - Consequences to hearing during the conservative management of vestibular
schwannomas.
AB - OBJECTIVE: To estimate the risk of loss of serviceable hearing during the
conservative management of vestibular schwannomas. STUDY DESIGN: Retrospective
case review. METHODS: Twenty-five patients with a radiological diagnosis of
unilateral vestibular schwannoma were managed conservatively for a mean duration
of 43.8 months (range, 12-194 mo). The pure-tone average (PTA) (0.5, 1, 2, and 3
kHz) and speech discrimination scores (SDS) were measured at regular intervals
throughout the entire duration of follow-up. Serviceable hearing was defined
using two criteria: 70% SDS/30 dB PTA (the 70/30 rule) and 50% SDS/50 dB PTA (the
50/50 rule). The size and growth rate of tumors were determined according to the
American Academy of Otolaryngology-Head and Neck Surgery guidelines (1995).
Intervention was recommended if there was evidence of continuous or rapid
radiological tumor growth, and/or increasing symptoms or signs suggestive of
tumor growth. RESULTS: The risk of loss of serviceable hearing for the total
group was 43% using the 70/30 rule and 42% using the 50/50 rule. Tumor growth was
considered significant (> 1 mm) in 8 tumors (32%) and nonsignificant in 17 (68%).
The risk of loss of serviceable hearing for the tumor-growth group was 67% using
the 70/30 rule and 80% using the 50/50 rule. In contrast, the risk of loss of
serviceable hearing for the no tumor-growth group was 25% using the 70/30 rule
and 14% using the 50/50 rule. No audiological factors predictive of tumor growth
were identified. CONCLUSIONS: There is a significant risk of loss of serviceable
hearing during the conservative management of vestibular schwannomas. This risk
appears to be greater in tumors that demonstrate significant growth.
PMID- 10680926
TI - Dynamic asymmetry of the vestibulo-ocular reflex in unilateral peripheral
vestibular and cochleovestibular loss.
AB - OBJECTIVE: Rotatory tests in the horizontal plane have shown various degrees of
vestibulo-ocular reflex (VOR) asymmetry in patients after surgical
deafferentation of one labyrinth. The purpose of this work was to characterize
dynamic horizontal VOR responses among patients presenting with a unilateral
peripheral labyrinthine deficit of nonsurgical origin and to compare results in
isolated vestibular loss versus cochleovestibular loss. STUDY DESIGN: This study
included 40 patients who presented with an acute, spontaneous unilateral
peripheral labyrinthine lesion. Twenty-two patients had vestibular loss alone
(without associated hearing impairment) and 18 presented with a cochleovestibular
deficit (sudden hearing loss with vertigo). The majority of these patients were
part of a long-term protocol to evaluate vestibular compensation. METHODS: All
patients underwent both the clockwise test and the counterclockwise rotatory test
in the horizontal plane, using brief impulses of moderate intensity. Results were
analyzed by a simplified model of vestibular function, allowing a parametric
estimation of the response. RESULTS: A weak and transitory horizontal VOR
asymmetry was observed in the 22 patients with vestibular loss. However, the 18
patients with cochleovestibular loss demonstrated a more severe and persistent
asymmetry. CONCLUSIONS: This study revealed a difference in the dynamic
characteristics of the horizontal VOR between patients with vestibular loss and
those with cochleovestibular loss. Our results support the presence of an
extensive labyrinthine lesion in cochleovestibular deficit that involves the
otolith organs. The implications of this involvement on the central mechanisms of
otolith-canal interaction are discussed.
PMID- 10680927
TI - Pressure transfer between intracranial and cochlear fluids in patients with
Meniere's disease.
AB - OBJECTIVES: To elucidate the pressure transfer between intracranial and
labyrinthine fluids in patients with well-defined unilateral Meniere's disease.
STUDY DESIGN: Eleven patients previously exposed to hypobaric pressure agreed to
be investigated further with the tympanic membrane displacement (TMD) technique.
TMD was used to indirectly analyze perilymph pressure changes as the result of
changes in body position. METHODS: Repeated measurements for both the diseased
and the healthy ears were made with the patients supine and then in a sitting
position. The TMD parameters for the maximum inward displacement, the Vi, and the
mean volume displacement, the Vm, were calculated and compared. RESULTS: The
paired comparison showed statistically significant larger Vi values for both ears
in the supine position. A similar tendency was observed for the Vm value. This
difference of the Vi was significantly larger for the diseased ear compared with
the currently healthy ear. The results were compared to the audiometric and
electrocochleographic results previously obtained on the same patients when they
were subjected to hypobaric pressure. Patients who experienced the largest
differences in hearing level thresholds in the lower frequencies also showed the
greatest differences in TMD values as the result of postural changes.
CONCLUSIONS: Despite the limited number, the statistically supported results
suggest a relation between the efficiency of the routes of pressure transfer and
the observed effect of hypobaric exposure. The results also indicate that for the
patients tested, the routes of communication are more effective in the diseased
ear than in the healthy ear--a condition that may relate to the pathogeneses of
Meniere's disease.
PMID- 10680928
TI - Temporal bone histopathology in connexin 26-related hearing loss.
AB - OBJECTIVE: Mutations in GJB2, a gene that encodes a gap junction protein,
Connexin 26 (Cx26), are responsible for approximately one third of sporadic
severe-to-profound or profound congenital deafness and half of severe-to-profound
or profound autosomal recessive nonsyndromic hearing loss (ARNSHL). Mouse mutants
homozygous for knockouts of this gene are nonviable, precluding histopathologic
studies of the associated inner ear pathology in this animal model. Therefore, we
studied archival temporal bone sections to identify temporal bone donors with
Cx26-related deafness. STUDY DESIGN: Temporal bone donors with a history of
congenital severe-to-profound or profound deafness were identified in the
registry of the Temporal Bone Library at the University of Iowa. Histological
findings were interpreted in a blinded fashion. DNA extracted from two celloidin
embedded mid-modiolar sections from each temporal bone was screened for the
35delG Cx26 mutation. The entire coding region of Cx26 was screened for other
deafness-causing mutations if the 35delG mutation was detected. RESULTS: Of five
temporal bone donors with congenital severe-to-profound deafness, one donor was
found to have Cx26-related deafness. This individual was a Cx26 compound
heterozygote, carrying the 35delG mutation and a noncomplementary Cx26 missense
mutation on the opposing allele. Microscopic evaluation of this temporal bone
showed no neural degeneration, a good population of spiral ganglion cells, near
total degeneration of hair cells in the organ of Corti, a detached and rolled-up
tectorial membrane, agenesis of the stria vascularis, and a large cyst in the
scala media in the region of the stria vascularis. CONCLUSION: This study is the
first to report the temporal bone histopathology associated with Cx26-related
deafness. Preservation of neurons in the spiral ganglion suggests that long-term
successful habilitation with cochlear implants may be possible in persons with
severe-to-profound or profound Cx26-related deafness.
PMID- 10680929
TI - Levels of intracellular protein and messenger RNA of mucin and lysozyme in normal
human nasal and polyp epithelium.
AB - OBJECTIVES: Mucus hypersecretion is a characteristic feature in chronic sinusitis
with nasal polyps. The objective of this study is to examine whether the polyp
epithelium itself contributes to a certain extent to the increased mucous
secretions in chronic sinusitis with nasal polyps, and if it does, to determine
which mucin genes are responsible for the increased mucin secretion. METHODS:
Three pooled samples of normal nasal epithelial cells from each subject were
obtained by scrapings from the inferior turbinates of 30 healthy adult volunteers
and nasal polyps from 6 patients who underwent intranasal ethmoidectomy and
polypectomy. Isolated epithelial cells were used for total RNA isolation for
reverse transcriptase polymerase chain reaction and cell lysates for
immunoblotting. RESULTS: The intracellular level of mucin from polyp epithelium
was 2.9 times higher than that of normal nasal epithelium (P < .05).
Interestingly, MUC2 and MUC8 messenger RNA (mRNA) levels were clearly upregulated
in polyp epithelium compared with those of normal turbinate epithelium.
CONCLUSIONS: Polyp epithelium can be considered to contribute in part to
increased secretion in chronic sinusitis with polyps, and increased mucous
secretion might be related to the increased mRNA level of MUC2 or MUC8 or both.
PMID- 10680930
TI - Fontanelle and uncinate process in the lateral wall of the human nasal cavity.
AB - OBJECTIVES: Although a complete anatomic knowledge of the fontanelle is a
prerequisite to perform a surgical antrostomy opening, little is known about the
boundary, shape, and size of the fontanelle. The purpose of this paper is to
determine the best site for maintaining the patency of a surgical antrostomy
opening by defining the anatomic boundaries, shape, and size of the fontanelle as
well as its histological structure. MATERIALS AND METHODS: One hundred sagittally
divided heads were utilized. Mucosa overlying the lateral nasal wall was
carefully removed with an operating microscope under 6x magnification. In some
cases, a double mucous membrane, including the posteroinferior portion of the
uncinate process, was cut as a whole and embedded in paraffin. The sections were
stained with H&E. RESULTS: The boundary of the fontanelle and the location of the
natural ostium were described in detail. Eight patterns of the posteroinferior
portion of the uncinate process were observed. There were three major fontanelle
shapes when observed from the medial aspect to the lateral: triangular, pencil
like, and oval. The triangular type was the most common. The anterior portion of
the fontanelle was shorter than the posterior when observed medially and was
wider than the posterior portion when observed inferiorly. CONCLUSIONS: The
anterior portion of the fontanelle is more prone to stenosis than the posterior
portion. An antrostomy in the posterior fontanelle may be more ideal for a middle
meatal antrostomy of the maxillary sinus.
PMID- 10680931
TI - Extradural extranasal combined transmaxillary transsphenoidal approach to the
cavernous sinus: a minimally invasive microsurgical model.
AB - The authors have previously described an extradural transmaxillary approach to
the anterior compartment of the cavernous sinus. In an effort to expand the
surgical access to that area without necessitating a craniotomy or wide
transfacial dissection, they present a modification of the transmaxillary
approach to the sellar region and cavernous sinus. METHODS: The approach was
developed on 12 fresh and 12 embalmed cadaveric specimen, and 2 dry skulls. The
initial sublabial incision is followed by a maxillotomy to expose the course of
the infraorbital nerve (terminal branch of maxillary branch of the trigeminal
nerve) on the roof of the maxillary sinus. The route of the infraorbital nerve is
traced to the pterygopalatine fossa as a guide to the foramen rotundum.
Superomedial drilling of the foramen rotundum is then performed to reveal the
contents of the superior orbital fissure. After the nerves are safely identified
in the superior orbital fissure, medial enlargement of the window into the
cavernous sinus is made possible by drilling the lateral and posterior wall and
septum of the sphenoid sinus. RESULTS: The combined transmaxillary
transsphenoidal approach offers an excellent exposure of the sellar and
infrasellar region. The approach offers clear visualization of the ipsilateral
loop of the carotid artery, the pituitary fossa, and the cranial nerves of the
ipsilateral cavernous sinus. Mean operative reach is 38 mm from the posterior
wall of the maxillary sinus to the ipsilateral carotid loop and 56 mm to the
contralateral loop. The width of the operative window is 26 mm at the base within
the cavernous sinus. CONCLUSION: The model offers a minimally invasive approach
that avoids the need for craniotomy or violating the nasal cavity. It may be
safely employed to access vascular as well as invasive lesions of the sellar and
infrasellar region. The approach offers excellent visualization of the
ipsilateral intracavernous carotid artery with both proximal and distal control,
as well as cranial nerves III, IV, VI, V2, the hypophyseal region, and the medial
aspect of the contralateral cavernous sinus.
PMID- 10680932
TI - Endoscopic sinus surgery using intraoperative computed tomography imaging for
updating a three-dimensional navigation system.
AB - OBJECTIVES: The use of three-dimensional navigation systems provides information
on the structures surrounding the field of operation and thereby reduces the risk
of iatrogenic damage. The computed tomography (CT) data conventionally used are
provided by preoperative scanning procedures, which means that tissue changes
coming about during surgery are not seen on the screen. An intraoperative CT
scanning procedure being able to update the CT data could provide a solution.
STUDY DESIGN: Endoscopic sinus operations using an intraoperative CT updating the
three-dimensional navigation system were performed on six persons to find out,
whether the above is true. METHODS: Different parameters, advantages, and
disadvantages in the cases of these six patients were compared with a group of 22
patients who underwent conventional endoscopic sinus surgery with different three
dimensional navigation systems without updating the CT data set. RESULTS: The
intraoperative CT for updating the three-dimensional navigation system provides
useful information for the surgeon. CONCLUSION: Balancing its advantages against
its disadvantages, the updating of the CT data set with intraoperative CT cannot
be recommended for conventional standard endoscopic sinus surgery.
PMID- 10680933
TI - Role of vascular reflex in nasal mucosal swelling in nasal allergy.
AB - OBJECTIVE: In patients with nasal allergy, antigen challenge on the unilateral
nasal mucosa results in nasal secretion not only in the ipsilateral but also in
the contralateral nasal cavities that can be inhibited almost completely by
premedication with atropine sulfate. The present study was performed to elucidate
if centrally mediated vascular reflex induced by antigen challenge plays a role
in nasal mucosal swelling in subjects with nasal allergy. METHODS: Variations of
mucosal swelling and mucosal blood flow in the ipsilateral and the contralateral
nasal cavities after unilateral antigen challenge were evaluated by acoustic
rhinometry and laser Doppler flowmetry in 20 patients with perennial nasal
allergy. RESULTS: Unilateral antigen challenge caused ipsilateral and
contralateral nasal mucosal swelling in 17 and 13 patients, respectively.
Incidence of contralateral nasal mucosal swelling after unilateral antigen
challenge was significantly higher compared with that after control disc
challenge (P < .001). In 10 patients in whom unilateral antigen challenge caused
bilateral nasal mucosal swelling, significant swelling of the nasal mucosa lasted
for more than 30 minutes in the ipsilateral nasal cavity after antigen challenge
compared with only 15 minutes in the contralateral nasal cavity. Peak values of
contralateral mucosal swelling were 45.3% of those of ipsilateral nasal mucosa.
CONCLUSIONS: Centrally mediated vascular reflex is partially involved in the
onset of nasal mucosal swelling observed after antigen challenge in subjects with
nasal allergy. However, nasal mucosal swelling that persists and proceeds even 20
minutes after antigen challenge is caused by the direct effects of chemical
mediators on the nasal vasculature.
PMID- 10680934
TI - Assessing olfactory function in laryngectomees using the Sniffin'Sticks test
battery and chemosensory evoked potentials.
AB - OBJECTIVES/HYPOTHESIS: Laryngectomees are often considered to be completely
anosmic. The aim of this study was to determine whether anosmia in laryngectomees
reflects diminished transport of odorants to the olfactory epithelium or
olfactory epithelial damage. STUDY DESIGN: Twenty-five laryngectomees were
examined psychophysically using the Sniffin'Sticks test battery. All patients
rated the degree of their subjectively perceived deficit on a rating scale.
Chemosensory evoked potentials were also recorded in 11 of 25 patients. RESULTS:
Sixteen patients complained very little about their smell deficit, even though
the psychophysical testing found 18 patients to be anosmic and 7 hyposmic.
Olfactory potentials could be recorded in only 7 of the 11 patients who received
this evaluation, despite the fact that all 11 perceived, at least vaguely, the
olfactory stimulus, H2S, during the recording sessions. No meaningful correlation
between the psychophysical and electrophysiological data was observed.
CONCLUSIONS: The psychophysical data revealed the laryngectomees to be either
functionally anosmic or hyposmic. The olfactory evoked potential data suggested
that at least in two thirds of the laryngectomized patients the olfactory system
had some function, even up to 22 years after surgery. Because patients in
everyday situations find ways to bring odorants to the olfactory mucosa, the low
number of complaints about subjectively perceived deficits is reasonable.
PMID- 10680935
TI - Arterial supply of the nasal tip in Asians.
AB - OBJECTIVES: The blood supply to the nasal tip and columella was examined to
determine whether it could be damaged as a result of transcolumellar incision
during an external rhinoplasty approach in Asians. METHODS: The blood vessels
that supply the nasal tip were examined by dissecting 51 cadavers, and their
corresponding 102 nasal sections were injected with red latex before dissection.
The size and distribution of the vessels were measured with the unaided eye and
the primary supply vessels were determined. The subdermal layer in which the
vessels lie and the course of the vessels were also investigated. RESULTS: The
main blood supply source of the nasal tip proved to be the lateral nasal artery
in 78% (80/102) of the cases examined, while the remaining cases (22%) received
their blood supply via the dorsal nasal artery. Columellar branches were narrow
in diameter and varied in size and appearance, and were therefore appeared
insufficient as a main blood supply. These arteries passed through the
musculoaponeurotic layer, but they were also in close proximity to the main
surgical plane in the dome of the lower lateral cartilage. CONCLUSIONS: The
authors speculate that the nasal tip blood supply in Asians is primarily derived
from the lateral nasal or dorsal nasal arteries, with a variable contribution
from the columella arteries. Therefore, it is important to correctly determine
the surgical plane below the musculoaponeurotic layer in order to prevent skin
flap necrosis or nasal tip deformity that may occur from damage to the main
vessel during an external rhinoplasty approach.
PMID- 10680937
TI - Interventional sialendoscopy.
PMID- 10680936
TI - Long-term use of preservatives on rat nasal respiratory mucosa: effects of
benzalkonium chloride and potassium sorbate.
AB - OBJECTIVES: The preservatives benzalkonium chloride (BZC) and potassium sorbate
(PS) are widely used, not only for nasal drops, but also for eyedrops and
cosmetics. However, there have been many case reports that consider lesions such
as dermatitis or conjunctivitis to be the results of irritation induced by BZC or
PS. METHODS: We evaluated the histological changes after the long-term
administration of BZC or PS on rat nasal respiratory mucosa. Forty rats were used
for the BZC group and 40 rats for PS group. Animals in each group were divided
into four subgroups The first subgroup received a low-concentration preservative
solution that was commonly used for nasal sprays. The second subgroup received a
high-concentration preservative solution that was reported to induce dermatitis
in humans. The third and fourth subgroups received a steroid mixed preservative
solution of low and high concentrations, respectively. The control group was
administrated normal saline. After each group received 1, 2, and 4 weeks of
topical administration, the symptomatic and histological changes on H&E stain
were observed. RESULTS: Sneezing and nasal rubbing with forelegs were observed in
almost all subgroups by the seventh day of treatment. The preservatives induced
nasal lesions, including intraepithelial glandular formation, inflammatory cell
infiltration, vascular hyperplasia, and edematous change. The symptomatic and
histological changes were pronounced with the prolonged duration of
administration. Similar results were observed in the steroid mixed-solution
groups. In the PS steroid mixed-solution group, however, symptoms and nasal
lesions were reduced with the prolonged duration of administration. CONCLUSION:
It is our finding that even a low-concentration solution of preservative can lead
to nasal lesion. Hence there is a strong need to develop both a preservative that
can be safely and widely used and a nasal spray without preservatives.
PMID- 10680938
TI - Antimicrobial activity of synthetic salivary peptides against voice prosthetic
microorganisms.
AB - OBJECTIVES: To investigate whether synthetic salivary antimicrobial peptides have
an inhibitory effect on the growth of bacteria and yeasts isolated from used
silicone rubber voice prostheses. METHODS: The antimicrobial activities of six
synthetic salivary peptides (histatin 5, dhvarl, dhvar4, dhvar5, lactoferrin b
1730 [LFb 17-30], and cystatin S1-15) at concentrations of 2 and 4 mg/mL were
determined against different oropharyngeal yeast (four) and bacterial (eight)
strains and against a "total microflora" isolated from explanted voice prostheses
using agar diffusion tests. The spectrum of susceptible microorganisms was
determined qualitatively. RESULTS: Histatin 5 and cystatin S1-15 did not show any
antimicrobial activity against the microorganisms involved in this study. Dhvar1
was active against some of the oropharyngeal microorganisms tested, including the
yeast strains, but not against Rothia dentocariosa, Staphylococcus aureus,
Escherichia coli, and the total microflora Dhvar4 was active against all
microorganisms tested, including the total microflora. Dhvar5 lacked activity
against E coli and the total microflora LFb 1730 did not inhibit the growth of
any of the yeast strains involved and showed only minor activity against some of
the bacterial strains. LFb 1730 slightly inhibited the growth of the total
microflora from an explanted prosthesis. CONCLUSIONS: The synthetic salivary
peptide dhvar4 has a broad antimicrobial activity against all microorganisms that
are commonly isolated from explanted voice prostheses, including yeasts.
Therewith, it may represent a useful drug, as an alternative for antibiotics and
antimycotics employed in various ways to prolong the lifetime of voice prostheses
in laryngectomees.
PMID- 10680939
TI - Postoperative airway findings after maxillomandibular advancement for obstructive
sleep apnea syndrome.
AB - OBJECTIVE: To evaluate the upper airway characteristics in the early
postoperative period after maxilomandibular advancement for obstructive sleep
apnea syndrome. METHODS: Nasopharyngolaryngoscopy was performed before and 48
hours after surgery on 70 consecutive patients who underwent maxillomandibular
advancement for obstructive sleep apnea syndrome. The preoperative and the
postoperative evaluations were performed by the same examiner for consistency.
RESULTS: Mild to moderate lateral pharyngeal wall edema was identified in 70
consecutive patients. Fourteen patients (20%) had edema as well as ecchymosis
involving the pyriform sinus and aryepiglottic fold. Four of these patients (6%)
were also noted to have hypopharyngeal hematoma involving the pyriform sinus,
aryepiglottic fold, arytenoid, and false vocal cord that partially obstructed the
airway. These four patients were closely monitored for 1 to 2 additional days for
possible expanding hematoma leading to airway compromise. None of these patients
were found to have airway difficulty, and the minimum oxygen saturation was more
than 90% throughout the hospitalization. All four patients were discharged
uneventfully, and the hematoma resolved completely within 10 days. CONCLUSION:
Although postoperative edema was expected after maxillomandibular advancement,
hypopharyngeal hematoma was unexpected. Although none of our patients had
evidence of airway difficulty, the possibility of an expanding hypopharyngeal
hematoma should be considered in patients complaining of breathing difficulty
after maxillomandibular advancement surgery.
PMID- 10680940
TI - Predictive factors for complications in children with laryngeal damage at
extubation.
AB - OBJECTIVES: To determine which factors contribute to early complications when
intubated children show macroscopic lesions at extubation. STUDY DESIGN:
Retrospective review of 96 consecutive medical records of children aged 1 day to
15 years. Patients were divided into three groups depending on the extent of the
subsequent treatment required: medical, reintubation, and surgical. METHODS: Age,
sex, clinical history, and macroscopic features of the lesions were collected and
data were compared in each group. RESULTS: Underlying noninfectious respiratory
diseases and young age were found to be risk factors for higher incidence of
complications, but not prolonged or multiple intubations. Edema, especially in
the glottic area, was a risk factor for surgical treatment. Multiple lesions were
risk factors for reintubation. CONCLUSIONS: History of intubation, its cause, and
lesions discovered at extubation can provide the basis for definition of an "at
risk" profile for intubated children.
PMID- 10680941
TI - Endonasal laser surgery with a new laser fiber guidance instrument.
PMID- 10680942
TI - New millennium, new values: citizen participation as the democratic ideal in
health care.
PMID- 10680943
TI - Prenatal care in the first trimester: misleading findings from HEDIS. Health Plan
Employer Data and Information Set.
AB - OBJECTIVE: To understand factors influencing Health Plan Employer Data and
Information Set (HEDIS) rates for the measure 'Prenatal care in the first
trimester'. DESIGN: Telephone survey of a retrospective cohort of women with a
live birth. Medical record review of a sample of both responders and non
responders to the telephone survey. Detailed review of HEDIS data collection
procedures. SETTING: A managed care plan in California. STUDY PARTICIPANTS: Women
aged 18-49 years at date of delivery, who delivered a live birth from 1 October
1995 through 31 March 1996, and who were continuously enrolled in a California
managed care plan for 12 months prior to delivery (telephone survey, n= 1,185;
medical record review, n= 465). RESULTS: Of the women participating in the
telephone survey, 95% indicated that their first prenatal visit occurred during
the first 3 months of pregnancy. Using HEDIS 3.0 standards, a review of medical
records for a sample of these women indicated that 94% of the women initiated
care during the first trimester. These results contrasted sharply with 1995 and
1996 HEDIS rates of 64% and 75%, respectively. CONCLUSION: An investigation of
the discrepancy between HEDIS rates and rates from both telephone survey and
medical record review led to the finding that the low HEDIS rates were due not to
a true low rate of early care, but to data collection problems, including
difficulty obtaining medical records. Potential solutions involving health plan
activities, revisions to the official HEDIS process and revised reporting of
results are proposed.
PMID- 10680944
TI - How do we compare with our colleagues? Quality of general practitioner
performance in consultations for non-acute abdominal complaints.
AB - OBJECTIVE: To investigate what factors influence the quality of general
practitioner performance in consultations for non-acute abdominal complaints and
to establish the extent to which performance quality differs between general
practitioners (GPs). DESIGN: Explorative study in two parts: (i) detection of
variables influencing quality scores of consultations; and (ii) comparison of
mean quality scores of the consultations, selected by each GP. SETTING: Sixty-two
family practices across The Netherlands. SUBJECTS: Eight-hundred and forty
consultations concerning non-acute abdominal complaints, first encounters; 62
GPs. METHOD: Multilevel analysis was carried out to detect factors that influence
quality. After correction for the effect of significant factors the mean quality
scores of individual GPs were calculated and compared. RESULTS: Eighty-eight per
cent of the total variance in quality scores was located at the
consultation/patient level, and 12% at the GP level. One consultation
characteristic had significant influence on quality: quality scores were higher
in consultations of longer than average duration (>15 minutes). Several patient
characteristics were of significant influence. Consultation quality scores were
higher in consultations for patients with upper abdominal or non-specific
abdominal complaints. Quality scores were lower in consultations with female
patients and with patients aged >40 years. Together these characteristics
explained 20% of the variance at the GP level. None of the GP characteristics
investigated in this study appeared to have significant influence on the quality
of their performance. After correction of the scores for the effect of
significant factors the differences in performance quality between GPs remained
significant. CONCLUSIONS: Quality of performance is far more influenced by
consultation and patient characteristics than by GP characteristics. After
correction for influencing factors, the mean quality scores of GPs still differed
considerably and significantly. For many GPs the quality scores varied
substantially between different consultations; to a large extent this variation
remained unexplained. Consultation quality can be improved by booking more time
per patient and by giving more medical/technical attention to female and older
patients.
PMID- 10680945
TI - Physician attitudes, self-estimated performance and actual compliance with
locally peer-defined quality evaluation criteria.
AB - BACKGROUND: Physicians' agreement with quality evaluation criteria, and estimates
of their own and their colleagues' compliance with these criteria were compared
with actual compliance. METHODS: Physicians practicing in 10 health centers in
Spain defined 13 quality evaluation criteria for two patient conditions (upper
respiratory infections and high serum cholesterol). Compliance with criteria was
measured by an external team, using random samples of medical records stratified
by condition in each health center (n= 1,000). Concurrently, physicians were
surveyed regarding agreement with the criteria, and were asked to estimate their
own and their health center's rate of compliance with these criteria. RESULTS:
Agreement ratings varied from 5.9 to 9.1 on a 10-point scale. Actual compliance
rates ranged from 1.8 to 91.7% of records. Agreement correlated significantly
with self-reported compliance but not with actual compliance. Estimates of one's
own and one's health center compliance were positive and significantly correlated
for all criteria, but were significantly higher for oneself than for one's health
center for six of 13 criteria. CONCLUSIONS: Wide variation in physicians'
agreement on quality criteria and in actual performance reveal a lack of clear
guidelines. Agreement on criteria did not always translate into compliance with
criteria. Physicians tended to rate their own performance as better than the
average of their peers, suggesting that aggregate data may not influence
physicians to change. Self-estimate of one's own or one's colleagues performance
is not a good proxy for actual performance so that peer ratings are of dubious
value for performance appraisal.
PMID- 10680946
TI - Using patient surveys to measure the quality of outpatient care in Krakow,
Poland.
AB - OBJECTIVE: To test the feasibility of using patient reported information to
create indicators of quality (access, patient experience--including satisfaction,
and clinical quality) with the goal of providing Krakow city clinic managers (and
potentially other audiences) with information about the quality of outpatient
care in selected clinics. Setting and methods. Almost 2,000 patients from 19
outpatient clinics in Krakow, Poland were surveyed in November and December 1997
and January 1998. We prepared a self-completed questionnaire to capture data
about the patient's experience with access to services, interactions with
registration staff, communication with the doctor, information received from the
doctor, and receipt of preventive services. RESULTS: Access varied across
clinics. For example, 84% of patients waited less than 10 minutes at
registration, whereas only 53% of patients waited less than 30 minutes to see the
doctor. Among those who tried to register by telephone, only 72% were successful.
Satisfaction was highest with the doctor visit (satisfaction=79, on a scale of 1
100) and lowest with telephone registration (satisfaction = 59). Preventive
health care screening was generally disappointing, particularly for Papanicolaou
smear and clinical breast examination, although frequent users of a clinic (with
more opportunities for screening) generally had higher rates of screening.
CONCLUSION: We demonstrated the feasibility of constructing indicators of
multiple dimensions of the quality of outpatient care using patient-reported
information. Quality dimensions captured by survey included access, patient
experience and clinical quality. Results were successfully summarized in easy to
read and understand formats for clinic managers and city health department
officials.
PMID- 10680947
TI - Construction of a scale measuring inpatients' opinion on quality of care.
AB - OBJECTIVE: To develop a reliable and valid measure of patient opinions on quality
of hospital care. DESIGN: Issues of importance to patients and possible scale
items were generated by literature review and non-structured interviews of
patients, former patients, health care providers and researchers. Semi-structured
interviews with inpatients and pilot studies were conducted to modify or remove
ambiguous questions and reduce skewed responses. A study was then made to select
from these questions relevant items and variables correlated to patient
evaluation of quality of care. A principal-components analysis was performed to
select items and assess construct validity. Cronbach's alpha coefficients were
calculated to estimate the reliability of the scale. Time reliability and
concurrent validity were also considered. SETTING: An 800-bed French short-stay
teaching hospital in Paris. STUDY PARTICIPANTS: Five-hundred and thirty-four
consecutive patients hospitalized in eight medical and surgical wards. RESULTS: A
26-item scale was developed. Component analysis indicated two subscales: 'medical
information' and 'relationship with staff and daily routine'. Levels of
reliability were satisfactory: Cronbach's alpha coefficient exceeded 0.87 for
overall scale and subscales. Concurrent validity and time reliability were also
satisfactory. Multivariate analysis showed that, taking into account patients and
hospitalization characteristics linked to scores (age, health status, number of
hospitalizations, comorbidity, time since diagnosis, admission pattern, private
patient and difficulties reported by staff), these scores differed among
departments. CONCLUSION: A reliable, valid measure of inpatients' opinions on
quality of care has been developed in a French hospital and variables that have
to be taken into account to compare hospital departments have been selected.
Items selected in the scale emphasized the importance that patients give to
receiving medical information.
PMID- 10680948
TI - Quality of diabetes care in a university health center in Lebanon.
AB - OBJECTIVE: To assess the quality of care provided to diabetic patients by family
physicians in a university health clinic, using measures of glycemic and
cardiovascular risk control as well as documentation of and adherence to World
Health Organization (WHO) guidelines for diabetes primary care. DESIGN: Chart
review of the previous year's medical notes for all identified diabetics in the
practice over 2.5 years. RESULTS: Two-hundred and four diabetic patients were
identified, with an estimated prevalence of 4.1%. The majority was type II
diabetics, on oral hypoglycemic agents. Glycosylated hemoglobin was documented in
39.7% of patients, fasting plasma glucose in 99%, cholesterol in 93.1%,
triglycerides in 91.2% and blood pressure in 85.8%; optimal control of these
indicators was noted in 28.4%, 17.8%, 34%, 29.6% and 55.4% respectively. Fifty
percent of the diabetics were referred for retinal checks. Physicians documented
the presence of nephropathy in 46.8% and neuropathy in 59.6%; however, they
documented patient instruction on foot care, diet, exercise and diabetes self
care poorly. CONCLUSION: There is a need for interventions to improve management
and documentation in diabetes care in order to achieve early detection and
prevention of complications. Developing a protocol for the clinic based on
standard guidelines, and the use of flow sheets may be helpful in improving these
intermediate indicators of quality of care.
PMID- 10680949
TI - Determinants of users' satisfaction with primary health care settings and
services in Saudi Arabia.
AB - OBJECTIVE: To identify the components of primary health care that cause most
concern to service users and to identify socio-demographic and other factors
associated with satisfaction among the users of primary health care centres.
DESIGN: Interviews conducted by well-trained interviewers with a random sample of
heads of households. The questionnaires were composed of questions that measure
the extent of satisfaction with settings and services in the primary health care
centres using a 5-point rating scale from very satisfied to very dissatisfied.
SETTING: The community of Qateef, eastern Saudi Arabia. STUDY PARTICIPANTS: A
sample of 802 households representing 838 families was chosen randomly from the
housing lists of the primary health care centres in Qateef. There were 40 vacant
houses and nine refusals. Thus the number of heads of households actually
interviewed was 789. RESULTS: Waiting area structure, confidentiality measures
and environmental structure were the areas that caused most concern to service
users. The factors that showed the greatest association with satisfaction were
the type of the primary health care centre building (purpose-built or rented),
literacy status of the household head (literate or illiterate), the extent of the
primary health care centre utilization (regular or infrequent). Surprisingly, age
showed no association when other characteristics of the respondents were adjusted
for, and sex was less important than in other studies. CONCLUSION: How regular
the respondent was in using his or her primary health care centre was more
predictive in deciding the extent of satisfaction with the various components in
the study than the other variables. Socio-demographic factors played minor roles
in deciding the extent of satisfaction, although each had a deciding role with
one or more, but not all, components.
PMID- 10680950
TI - Communication gaps in paediatric care.
PMID- 10680951
TI - Chicken antibodies: a clinical chemistry perspective.
AB - The chicken immune system has been studied for many years and these studies have
contributed substantially to our understanding of the fundamental concepts of
immunology and the development of different immunoglobulin classes. It is thus
surprising that only a small fraction of the antibodies presently used in
laboratories are of avian origin. A laying hen produces more yolk antibodies than
a rabbit can produce during the same time period, and the animal care costs are
lower for the chicken compared to the rabbit. Chicken antibodies offer many
advantages to the traditional mammalian antibodies when used for the detection of
mammalian antigen. Due to the evolutionary difference chicken IgY will react with
more epitopes on a mammalian antigen, which will give an amplification of the
signal. Chicken antibodies can also be used to avoid interference in
immunological assays caused by the human complement system, rheumatoid factors,
human anti-mouse IgG antibodies (HAMA) or human and bacterial Fc-receptors. The
antibodies can be purified in large amounts from egg yolk, making laying hens
highly efficient producers of polyclonal antibodies.
PMID- 10680952
TI - Exercise-induced bronchoconstriction in adults with asthma--comparison between
running and cycling and between cycling at different air conditions.
AB - The bronchial response to cycling and running was compared in six adult asthmatic
persons. The effects of different air conditions during cycling regarding the
induction of bronchoconstriction was studied. The exercise consisted of 6
minutes' work at an intensity of 80-85% of maximal heart rate. Heart rate, oxygen
consumption and ventilation were measured to check that the exercise level was
the same in all tests. Peak expiratory flow (PEF) was used to test for
bronchoconstriction. Bicycling and treadmill running were performed under indoor
conditions and bicycling while breathing cold, dry air (-18 degrees C) and room
tempered humid air (60% RH), respectively. No difference in bronchoconstriction
was found between cycling and running under indoor conditions. However, bicycling
exercise with inhalation of cold dry air provoked more bronchoconstriction than
when inhalating humid air (PEF reductions of 19.4+/-6% and 6.1+/-2%,
respectively). No differences were found between the exercise modes in heart
rate, oxygen consumption, ventilation per minute, respiratory rate, carbon
dioxide elimination or subjective ratings of perceived exertion and
breathlessness. It is concluded that it is not the type of exercise, but the
ventilation demand and humidity of the inspired air that are the main
determinants of the occurrence and degree of bronchoconstriction.
PMID- 10680953
TI - Expression of prostasome-like granules by the prostate cancer cell lines PC3,
Du145 and LnCaP grown in monolayer.
AB - Prostasomes are a granular type of secretory product in the human prostate gland
cells. It is not known, whether in vitro grown cells derived from human prostate
cancers also express prostate secretory components containing granules with
properties similar to the prostasomes. Therefore, we carried out the present
investigation and found that cytospins of in vitro grown PC3, DU145 and LNCaP
cells generally expressed a granular secretion. DU145 demonstrated the highest
ratio of cells with granules (about 90%), while cytospins of PC3 and LNCaP
contained less stained cells (50-70%). Purified granules from PC3 cells were
immunoreactive with a monoclonal antibody (mAb78) originally raised against human
seminal prostasomes. The PC3 granules also shared the property with human seminal
prostasomes having an elevated UV260/UV280 absorbance ratio. On the other hand we
found a low aminopeptidase activity in PC3 granules contrary to that of human
prostasomes. Prostasomes may form a heterogeneous group with different properties
due to the source from which they are isolated and perhaps it is justified to
recognize them as different members of a prostasome family.
PMID- 10680954
TI - Poorly differentiated, solid-type adenocarcinoma of the stomach.
AB - Data of 58 cases of poorly differentiated, solid-type adenocarcinoma of the
stomach treated at our hospital between 1985 and 1995 were reviewed and compared
to data of 146 cases of non-solid-type carcinoma in order to determine whether
there are distinguishable clinicopathological features between these two types of
carcinoma. Significant differences were observed with respect to tumor size,
stage, macroscopic appearance, depth of invasion, histologic growth pattern,
lymph node metastasis, microscopical lymphatic invasion and vascular permeation.
Patients in the solid-type cancer group tended to have smaller tumors; the
disease was in the early stage in 48% of the patients, and total gastrectomy was
performed in only 20 of the 58 patients. Nodal involvement, lymphatic invasion
and vascular permeation were also less common in patients with solid-type cancer.
The overall survival rate of patients with solid-type carcinoma was higher than
that of patients with non-solid-type carcinoma, though no significant differences
were observed when corrected for stage. Our results suggest that poorly
differentiated solid-type carcinoma of the stomach should be regarded as a
distinct type of adenocarcinoma that has a good prognosis. The significant
prognostic factors for this type of gastric cancer are lymphatic invasion and
tumor location.
PMID- 10680955
TI - Clinicopathologic prognostic features in patients with gastric cancer associated
with esophageal or duodenal invasion.
AB - BACKGROUND: We evaluated the influence of several clinicopathologic variables on
5-year survival of patients with gastric cancer associated with esophageal or
duodenal invasion, and determined the significance of resection line involvement.
PATIENTS AND METHODS: A review of the database for gastric adenocarcinoma at
Sendai National Hospital between January 1985 and December 1995 identified 923
patients who underwent gastric cancer resection. Of these patients, 37 were
reported to have tumour infiltration of the esophagus or duodenum on histological
examination of the resected specimens. Univariate and multivariate analyses of
patients with esophageal or duodenal invasion were performed to evaluate the
prognostic significance of clinicopathologic features. Then the patients were
divided into two groups based on the results of microscopic examination: a tumour
wedge-positive group for resection margins of less than 5 mm in width and a
tumour wedge-negative group for resection margins of more than 5 mm in width.
There were 8 patients in the narrow (margin-positive) group and 29 patients in
the wide margin (margin-negative) group, respectively. RESULTS: Univariate
analysis revealed that the significant prognostic factors were nodal involvement
(p=0.0004) and gross type (p=0.0031). Multivariate analysis of the esophagus or
duodenum-invaded cancer cases, however, revealed that only nodal involvement was
a significant prognostic factor. There were statistical correlations between
these groups (margin-positive and margin-negative groups) and the Borrmann type
of tumour and tumour size. The survival rate was worse in patients with tumour
line involvement. CONCLUSIONS: Multivariate analysis revealed that the prognosis
of patients with esophageal or duodenal invasion was affected only by nodal
involvement independently. The risk of surgical margin involvement was high in
cases of a large Borrmann type-4 tumour and infiltrative carcinoma.
PMID- 10680956
TI - Malignant fibrous histiocytoma: a method to control intraoperative hemorrhage by
clamping the feeding arteries.
AB - Malignant fibrous histiocytoma (MFH), also referred to in the past as malignant
fibrous xanthoma and fibroxanthosarcoma, is a tumor of mesenchymal tissue origin.
A case of retroperitoneal MFH was reported. In this paper, we describe a method
of hemostasis and intraoperative control of hemorrhage during resection of
retroperitoneal MFH by snaring the feeding arteries. The patient was successfully
operated on using this technique.
PMID- 10680957
TI - A qualitative study on changes in local brain pH due to discrete cerebral
microembolism.
AB - In this work autoradiography of 14C-5,5-dimethyl-2,4-oxazolidinedione (14C-DMO)
was used to trace changes in local cerebral pH in embolized awake rabbits. One
hour after i.v. injection of 14C-DMO small cerebral ischemic foci were produced
in rabbits by injecting plastic beads into the left heart ventricle under short
acting anaesthesia, and after another hour the animals were put to death and
their brains processed for autoradiography of 14C-DMO. Evidence of acidosis was
in general not found in the microischemic regions, though there were a few
possible exceptions. However in the hippocampus a diffuse acidosis involving a
large part of the structure, could be found in 2 of the 4 experiments. This
hippocampal phenomenon probably reflected the same process as has been observed
using autoradiography of 2-deoxyglucose (reflecting cellular glucose uptake) on
the same ischemic model increased 2-deoxyglucose phosphorylation. Because the
hippocampus is involved in the memory function and the fact that small infarcts
are coupled to dementia, this phenomenon should be drawn into focus for further
studies.
PMID- 10680958
TI - A mathematical model of in situ freezing in liquid nitrogen.
AB - In situ freezing is a procedure, typically applied in neuroscience, to halt
metabolism and diffusion. However, the freezing process is not instantaneous, and
the regional concentrations of a compound under study may change before the
tissue is completely frozen. Knowing the local freezing time, metabolic rate and
the diffusion coefficient of the compound of interest, it should be possible to
reconstruct the spatial concentration profile prevailing before the object was
placed in the cryogen. A mathematical model for calculating the temperature
changes at different depths in rabbit and rat heads cooled in liquid nitrogen has
been developed. By comparing with experimental results it has been found that the
mathematical model can be used for prediction of the local freezing time with a
small error.
PMID- 10680959
TI - Evaluation of the teratogenic potential of pyrazinamide in Wistar rats.
AB - We have tested Pyrazinamide (PZA), an essential component of modern short-course
tuberculosis treatment regimen, for teratogenicity using Wistar rats. The drug
was given by oral intubation from 6-15 days of gestation, at doses of 0, 25, 100
and 500 mg/kg body weight per day. Reduction in body weight and food consumption
were observed in the treated dams. On day 20 of gestation, all the dams were
killed by cervical dislocation and signs of maternal toxicity, reproductive
indices and fetal measurements were recorded. Dams given doses of 100 and 500
mg/kg had significantly higher incidence of reabsorbed fetuses, reduced litter
size, and impaired neonatal growth than those given no PZA or only 25 mg/kg dose.
External visceral and skeletal examination of all fetuses of PZA-treated dams
showed several types of variations which were neither dose related nor having a
consistent pattern. However, these variations occurred mostly in the dams treated
with the dose of 500 mg/kg. In conclusion, these data show that in Wistar rats,
only high doses of PZA (100 and 500 mg/kg) produced fetotoxicity. No evidence of
teratogenic effect of the drug was observed.
PMID- 10680960
TI - Assessment of template quality by the incorporation of an internal control into a
RT-PCR for the detection of rabies and rabies-related viruses.
AB - A method is described to assess RNA template quality by the incorporation of a
ribosomal RNA (rRNA) internal (in tube) control into a standard rabies and rabies
related virus specific RT-PCR. Specific virus and rRNA templates were co
amplified in a duplex reaction from RNA extracts derived from 60 isolates
representing all six of the established lyssavirus genotypes. To ensure a wide
species applicability of this technique we demonstrated that the rRNA assay was
capable of functioning using the cells or tissues of 14 different mammals.
Parallel studies between the duplex and the unlinked lyssavirus assay
demonstrated only a minor reduction in the sensitivity of the former test. The
ribosomal and viral targets (unlike beta-actin RNA) were shown to have similar
degradation kinetics making rRNA amplification a good control for viral target
integrity. As a consequence, the use of this system would reduce the likelihood
of obtaining false negative RT-PCR results from lyssavirus infected material.
PMID- 10680961
TI - A simple purification and fluorescent assay method of the poliovirus 3C protease
searching for specific inhibitors.
AB - Picornaviruses such as poliovirus, foot-and-mouth disease virus, and
encephalomyocarditis virus produce their proteins by translating their genomic
RNA, injected within the host cell, into a precursor polyprotein, which is then
subjected to precise processing. The polyprotein is cleaved into mature proteins
predominantly by the viral 3C protease. A simple purification and assay method
for poliovirus 3C protease for use for screening for inhibitors of the 3C
protease is described. A poliovirus cDNA fragment containing the 3C protease
coding region was inserted into pET22b vector and expressed in Escherichia coli.
The His-tagged protein (3CD'-His) was purified by a Ni-affinity column and the
activity of the purified enzyme was measured by a fluorescent assay with a
fluorogenic substrate containing the 3C-specific cleavage site, MocAc-MEALFQGPLQY
Dnp. The kinetic parameters calculated from the Lineweaver-Burk plot and the
effects of inhibitors showed that E. coli expression with His tag and the assay
using the fluorogenic substrate are efficient, simple and sensitive methods for
purifying the 3C protease, and measuring its activity.
PMID- 10680962
TI - Green fluorescence protein as a transcriptional reporter for the long terminal
repeats of the human immunodeficiency virus type 1.
AB - Using the enhanced green fluorescence protein (EGFP), a transient reporter
expression system was established to assess the transcriptional activity of the
long terminal repeats (LTR) of primary isolates of the human immunodeficiency
virus type 1 (HIV-1). Consistent with the conventional chloramphenicol acetyl
transferase (CAT) reporter, EGFP expression, under the direction of HIV-1 LTR,
was readily detected in the transient transfection and was elevated by co
transfection of HIV-1 tat-expression vector. Comparing to CAT, however, EGFP
expression system has two advantages: (i) Using a fluorescence activated cell
sorter (FACS), it was possible to simultaneously measure transfection efficiency
and fluorescence intensity of the transfected live cells without the necessity of
co-transfection of a reference plasmid for comparing the transcriptional activity
of two promoters; and (ii) EGFP expression was readily detected at a DNA
concentration where CAT activity was not detectable possibly because the
transfectants could be 'gated'. On the other hand, at a higher concentration of
DNA, CAT signal became more prominent than that of EGFP, possibly because the
enzymatic activity of CAT 'amplified' the signal. EGFP fluorescence detected by
FACS was a direct measurement of the expressed chromophore. It is concluded that
the system is rapid, reproducible, convenient and useful for quantitative
analysis of transcription.
PMID- 10680963
TI - The effects of cell passages on the cell morphology and the outcome of herpes
simplex virus type 1 infection.
AB - Because cell cultures are essential in biological research which involves the
analysis of virus morphogenesis, this study focused on examining the significance
of cell passages. Human embryonic lung fibroblasts (MRC-5) at passage (P) 27 were
seeded twice a week to P 32, P 40, and P 48, when just at confluence and then
infected with herpes simplex virus type 1 (HSV-1). The structure of the non-virus
infected (MOCK) and HSV-1 infected cells, the amount of cellular infectious virus
particles and the capability to express HSV-1 glycoproteins C (gC-1) and D (gD-1)
were investigated by phase-contrast and immunofluorescence light microscopy,
immunogold cryosection EM, plaque assays, immunoblots, and total protein assays.
Modified cell structure including fragmentation of tubulin fibers were visible in
MOCK from P 38 onwards. The quantity of vimentin remained unchanged while actin
accumulated and beta-tubulin decreased in HSV-1 infected late P cells compared to
early P cultures. Cells of high P counts contained significantly fewer infectious
virus particles, very likely of lower virulence, and their expression of gC-1 and
gD-1 were concordantly reduced. These observations indicate that the number of
cell P must be considered in order to reproduce results of cell biology and viral
morphogenesis. The MRC-5 cells ought not to be passaged more than ten times
beyond P 27 in the laboratory.
PMID- 10680964
TI - Use of the confocal microscope to determine polyomavirus recombinant capsid-like
particle entry into mouse 3T6 cells.
AB - The structural protein genes of polyomavirus were expressed in the baculovirus
system, and the proteins were found to assemble into capsid-like particles
capable of packaging insect cell DNA. Recombinant capsid-like particles could be
produced that were composed of the various structural proteins (VP1, VP1/2, VP1/3
and VP1/2 + VP3). Laser scanning confocal microscopy was used to determine if the
various capsid-like particles could infect (enter) mouse 3T6 cells. Each of the
various capsid-like particles was equally capable of cell entry as determined by
indirect immunofluorescence confocal microscopy.
PMID- 10680965
TI - Detection of sheep poxvirus in skin biopsy samples by a multiplex polymerase
chain reaction.
AB - The development of a multiplex polymerase chain reaction (PCR) method with
amplification of capripoxvirus in a single-step procedure from skin biopsies
using three primer pairs, two specific for capripoxvirus and one specific for
alpha-tubulin is described. A sensitive multiplex PCR was achieved by
optimization of parameters such as the primer concentrations, magnesium and dNTPs
concentrations. False negative results that sometimes arise due to inhibitors of
DNA amplification may be avoided by the inclusion in the assay of alpha-tubulin
primers. The results reported on 42 skin biopsies from sheep suspected to have
poxvirus infection, indicated that the assay could monitor simultaneously DNA
extraction from skin biopsy samples and allow improved detection of capripoxvirus
within 24 h of specimen receipt in the laboratory.
PMID- 10680966
TI - Serological diagnosis of varicella-zoster virus in sera with antibody-capture
enzyme-linked immunosorbent assay of IgM.
AB - Evaluation was made of three enzyme-linked immunosorbent assay (ELISA) formats;
varicella-zoster virus (VZV) indirect ELISA; VZV IgM capture using biotin and VZV
IgM capture using peroxidase, for the detection of VZV-specific IgM antibodies in
human sera. It was observed that there was no significant difference in
sensitivity of detection using the three formats but there were important
practical differences in the number of steps and hence time for assay completion
between the three assay formats. All assays showed some cross-reactivity with
sera containing anti-HSV1 antibodies.
PMID- 10680967
TI - Dot-blot nitrocellulose enzyme immunoassays for the detection of white-spot virus
and yellow-head virus of penaeid shrimp.
AB - Dot-blot nitrocellulose enzyme immunoassays (DB-NC-EIA) were developed for the
detection of white-spot virus (WSV) and yellow-head virus (YHV) in infected
shrimp. The assays utilized HRP-conjugated virus-specific antibodies to detect
virus antigen present in gill homogenates of infected shrimp spotted onto
nitrocellulose membrane. The assays are by far the simplest and most rapid
detection methods available for WSV and YHV.
PMID- 10680968
TI - Evaluation of newly developed microparticle enzyme immunoassays for the detection
of HCV antibodies.
AB - The newly developed anti-HCV assays AxSYM HCV version 3.0 and IMx HCV version 3.0
were evaluated with regard to their precision, sensitivity and specificity in
comparison to the HCV EIA 3.0 (Abbott GmbH, Wiesbaden, Germany). Precision
testing was undertaken using five positive controls with different anti-HCV
levels for each assay. Specificity was estimated by testing 4383 blood donor
specimens. The supplemental assay Matrix HCV 2.0 (Abbott GmbH, Wiesbaden,
Germany) was used to confirm repeatedly reactive results. Samples which had been
found to be positive or indeterminate by Matrix HCV 2.0 were tested by
qualitative polymerase chain reaction after reverse transcription (RT-PCR,
Amplicor HCV test, Roche Diagnostic Systems, Basel, Switzerland). To determine
sensitivity, 20 commercially available seroconversion panels were tested. Based
on supplemental testing, the apparent specificities of AxSYM HCV version 3.0, IMx
HCV version 3.0 and HCV EIA 3.0 were estimated to be 99.84, 99.98 and 99.80%,
respectively. In seroconversion panel testing, AxSYM and IMx HCV version 3.0
detected seroconversion in up to 12/20 panels earlier and in up to 1/20 cases
later than the comparison EIA. The highest sensitivity was shown in AxSYM HCV
version 3.0, followed by IMx HCV version 3.0 and HCV EIA 3.0. Based on the
improved seroconversion sensitivity and specificity, the AxSYM and IMx HCV
version 3.0 assays appear to be suitable for detecting HCV antibodies in blood
donor testing and other routine laboratory assessments.
PMID- 10680969
TI - Evaluation of different measles IgG assays based on recombinant proteins using a
panel of low-titre sera.
AB - During the WHO campaign to eradicate measles, accurate discrimination between
immune and non-immune individuals will become increasingly important. Due to
waning immunity in vaccinated populations, the performance of a measles IgG assay
depends mainly on its ability to detect reliably seronegative individuals among
many vaccinees with low antibody levels. New serological tests based on
recombinant proteins detect only a fraction of the total measles virus (MV)
specific antibodies. Therefore, several assays based on recombinant MV
haemagglutinin (ELISA and flow cytometry) or MV-fusion protein (flow cytometry)
as well as neutralisatlon and haemagglutination test have been evaluated using a
large panel of low-titre and negative sera. Since such an evaluation is highly
dependent on threshold values for positivity, the receiver operating
characteristic curve analysis was applied. The H-FACS and the H-ELISA showed the
best performing characteristics (specificity: 97.4 and 96.1%, respectively;
sensitivity: 88.1 and 89.6%, respectively) and may be an alternative to the
neutralisation assay. The number of undefined/grey zone sera was significantly
lower compared to a commercial whole virus-based ELISA and therefore fewer
individuals would be vaccinated unnecessarily.
PMID- 10680970
TI - Detection and diagnosis of parapoxvirus by the polymerase chain reaction.
AB - The genus Parapoxvirus includes four members, bovine papular stomatitis virus
(BPSV), pseudocowpox virus (PCPV), orf virus (ORFV) and parapoxvirus of red deer
in New Zealand (PVNZ). A set of primers for polymerase chain reaction (PCR) was
designed to detect viral DNA from cells infected with each of the four
parapoxviruses. The set of primers resulted in the amplification of appropriately
sized products from cells infected with BPSV, PCPV, ORFV and PVNZ, respectively.
The PCR method was applied for the detection of seven field isolates of
parapoxvirus from cattle, sheep and free-ranging wild Japanese serows. The
expected size of DNA was amplified from cells infected with each of the seven
isolates. No specific PCR products were detected from vaccinia virus-, fowlpox
virus- and mock-infected cells. Moreover, by a semi-nested PCR with an inner
primer and Southern blot analysis, viral DNA was detected from lesions of
clinically affected cattle, sheep and Japanese serows. These results suggested
that the PCR method used in this study was specific for the detection of
parapoxviruses and thus useful for diagnosis of parapoxvirus infections,
especially in discrimination from diseases with similar clinical symptoms.
PMID- 10680971
TI - cDNA probes for detection of specific dsRNAs from the fungal pathogen,
Monosporascus cannonballus.
AB - Monosporascus cannonballus is an ascomycete fungus that is the causative agent of
Monosporascus root rot/vine decline, a serious disease of muskmelon and
watermelon. Double-stranded RNA (dsRNA) was identified in approximately 60% of M.
cannonballus isolates recovered from infected muskmelon plants in 1993. After
repeated laboratory transfer on culture media, the majority of the isolates
harboring dsRNAs developed degenerate culture phenotypes and showed reduced
virulence (hypovirulence) to muskmelon. Initially, dsRNA purification and cDNA
synthesis were attempted in three M. cannonballus isolates harboring dsRNAs.
However, numerous difficulties were encountered due to the stable, double
stranded nature of the dsRNAs and contamination of the preparations by fungal
rRNA. Several purification and cDNA protocols were evaluated and eventually
modified into methods that were ultimately highly effective for cloning dsRNAs
from M. cannonballus. The cDNAs derived from purified dsRNA preparations were
cloned into a pUC119 plasmid vector and amplified in Escherichia coli. Nine cDNA
clones were identified that are specific for medium-sized (ca. 3 kbp) dsRNAs
associated with M. cannonballus isolate Ca91-17(96+). The methods used to make
the cDNA clones of the dsRNAs in M. cannonballus may be useful for those working
on fungal dsRNAs. In addition, these cDNAs may be useful for identifying dsRNAs
associated with the hypovirulence phenotype.
PMID- 10680972
TI - Folate-mediated drug delivery: effect of alternative conjugation chemistry.
AB - When utilized as a macromolecular drug targeting ligand, folic acid (Pte-Glu) has
traditionally been coupled to peptides, proteins and lipids via one of its two
carboxylate groups fortuitously located within a distal glutamyl moiety. It has
been assumed in the literature that the gamma-glutamyl carboxylate of Pte-Glu is
the preferred conjugation site for macromolecules enduring endocytosis via the
folate-binding protein receptor. However, it is also possible that the steric
placement of the attached macromolecule around the vitamin's pteridine moiety may
be the more influential parameter controlling this delivery mechanism. Using
solid-phase chemistries, we have synthesized dipeptide derivatives of pteroic
acid for the purpose of identifying the preferred site onto which a macromolecule
can be chemically attached without compromising its endocytosis potential. Thus,
using fluorescent and radiolabeled conjugates, we have determined that
macromolecules attached to Pte-Glu by either an alpha- or gamma-glutamyl linkage
could associate with receptor-bearing cells at virtually identical levels. We
further discovered that removal of the remaining un-conjugated glutamyl
carboxylate had no inhibitory effect on cell uptake; and, the cytotoxicity of
related momordin toxin conjugates were comparable among the various pteroate
derivatives tested. From these observations we suggest that the preparation of
endocytosis-competent pteroate-macromolecule conjugates is strongly influenced by
the steric environment around the ligand's para-aminobenzoic acid moiety, and
that no selective isomeric (i.e. alphaGlu versus gammaGlu) conjugation
requirement necessarily exists.
PMID- 10680973
TI - Selective delivery of adriamycin to a solid tumor using a polymeric micelle
carrier system.
AB - The anticancer drug, adriamycin (ADR), was incorporated by physical entrapment
into polymeric micelles for selective delivery to a murine solid tumor colon
adenocarcinoma 26 (C 26). In vivo antitumor activity of ADR was greatly enhanced
by this incorporation into polymeric micelles. Using one polymeric micelle
delivery system, the tumor completely disappeared at two doses, while free ADR
exhibited a fair inhibition effect on tumor growth only at the maximum tolerated
dose. Biodistribution analysis revealed that the physically entrapped micellar
ADR accumulated at tumor sites in a highly selective manner. These results
indicate that these polymeric micelles are a promising system for delivering
hydrophobic anticancer drugs selectively to solid tumor sites using a passive
targeting mechanism.
PMID- 10680974
TI - Lipid microsphere preparation of a lipophilic ceramide derivative suppresses
colony formation in a murine experimental pulmonary metastasis model.
AB - Ceramide is a well-known regulator of apoptosis and cell growth. In this study,
we synthesized lipophilic ceramide derivatives to incorporate into lipid
microspheres (LM) and their activity was evaluated in vivo. Cera 03, a lipophilic
ceramide derivative synthesized from membrane-permeable C2-ceramide, caused
potent growth inhibition and DNA fragmentation of Meth A-T tumor cells in vitro.
Its potency was similar to that of C2-ceramide. Both compounds increased the
proportion of apoptotic cells. Cera 02, the diacetylated form of natural ceramide
(Cer), also suppressed in vitro cell growth with a similar or higher potency to
that of Cer, but both were far less potent than C2-ceramide and Cera 03. LM
containing Cera 03 (Lipo-Cera 03) could not totally prevent metastatic incidence
of Meth A-T cells, but reduced pulmonary metastatic nodules in number.
Intravenous injection of Lipo-Cera 03 (1 mg/kg of Cera 03) produced about 35%
inhibition, while Lipo-Cera 02 had no significant effect. In conclusion, Lipo
Cera 03 may have potential as an antimetastatic drug and may also be a useful
tool for researching the role of ceramides in vivo.
PMID- 10680975
TI - Effects of methotrexate and cyclophosphamide on polyamine levels in various
tissues of rats.
AB - The effects of methotrexate (MTX) and cyclophosphamide (CYP) on body weight,
organ weight, and the concentration of putrescine, spermidine, and spermine in 14
different tissues were measured in rats that had been given these compounds for 5
consecutive days. These three polyamines in both the thymus and spleen of rats
treated with MTX and CYP showed a statistically significant decrease. Further,
putrescine in the seminal vesicles, kidney, liver, and small intestine of MTX
treated rats, and in the prostate, seminal vesicles, kidney, heart, liver, small
intestine, and lung of CYP-treated rats, spermidine in the prostate, seminal
vesicles, testis, thymus, spleen, kidney, heart, small intestine, and skeletal
muscle of CYP-treated rats, and spermine in the prostate, seminal vesicles,
kidney, heart, small intestine, and stomach of CYP-treated rats showed
statistically significant decreases. Recognition of the significance of polyamine
levels and attention to their response in anti-cancer drug therapy may have
clinical implications.
PMID- 10680976
TI - Pre-exposure of cells to cationic lipids enhances transgene delivery and
expression in a tissue culture cell line.
AB - Several factors influence non-viral transfection in tissue culture models
including nature of the cationic lipid, plasmid construction, and DNA lipid
complex, among others. The cell line itself is another confounding variable. Each
subcellular population may respond independently to the transgene or specific
delivery vector with regards to toxicity or transgene expression. In this study,
the SKnSH (human neuroblastoma) and COS-1 (African green kidney) cells were
exposed to three different treatments A, B, and C. Treatment A refers to cells
obtained from American Type Culture Collection (ATCC) and cultivated as
recommended, treatment B to cells that were grown in presence of cationic lipids
for two weeks, and treatment C to cells that were grown in presence of cationic
lipids for two weeks followed by normal media for two weeks to determine if lipid
mediated effects were reversible. Treatment B resulted in a three-fold increase
in transgene expression of a reporter gene as compared to the other treatments.
This increase in transgene expression appeared not to be related to alterations
in toxicity. Interestingly, the fluid phase endocytic uptake of fluorescently
labeled oligonucleotides was increased in treatment B. However, there was no
significant difference in the cellular-associated signal when fluorescently
labeled plasmid-DNA was evaluated. In COS-1 cells, no difference in transfection
was observed with treatment B illustrating that cell lines respond independently.
In conclusion, pre-exposure of SKnSH cells to cationic liposomes (treatment B)
resulted in higher transgene production.
PMID- 10680977
TI - Uptake by hepatocytes and biliary excretion of intravenously administered
polystyrene microspheres in rats.
AB - The in vivo uptake by hepatocytes and biliary excretion of fluorescein
isothiocyanate-labeled polystyrene microsphere with a particle size of 50 nm (MS
50) after intravenous administration was studied in rats. It was confirmed by
using confocal laser scanning microscopy that MS-50 was partially phagocytosed by
the hepatocytes and that MS-50 taken up by the hepatocytes existed exclusively
inside the cells 1 h after intravenous administration. Studies on the mechanism
of the uptake of MS-50 by the hepatocytes using the liver perfusion technique
revealed that a process mediated by apo-E was involved. After intravenous
administration of MS-50, about 4% of dose was excreted into bile in 24 h.
Pharmacokinetic evaluation of the excretion rate of MS-50 into bile showed that
the process followed first-order kinetics. Qualitative evaluation of the
fluorescence detected in the bile after intravenous administration of MS-50
revealed that the particles were certainly excreted into bile in an intact form.
From these results, it was suggested that intravenously administered MS-50 would
be partially phagocytosed by hepatocytes through a process mediated by apo-E and
that MS-50 ingested by hepatocytes would be partially excreted into the bile.
PMID- 10680978
TI - Characterization of norfloxacine release from tablet coated with a new pH
sensitive polymer, P-4135F.
AB - A new pH-sensitive polymer, P-4135F, was evaluated as a colon delivery device for
norfloxacine (NFLX) which is used for the therapy of patients with Vero toxin
producing Escherichia coli gastroenteritis. P-4135F has a dissolution threshold
pH of 7.2 which is higher than the conventional pH-sensitive polymers, Eudragit
S100 and L100. To compare the dissolution site of P-4135F coated tablets with
other enteric polymer coatings, mini-tablets containing sodium fluorescein (FL)
as a model drug were prepared by coating them with the three polymers. After oral
administration of FL mini-tablets to rats, the first-appearance time, Ti, of FL
into the systemic circulation was measured. The Tis were 0.7+/-0.2 h for Eudragit
L100, 1.8+/-0.4 h for S100 and 2.0+/-0.3 h for P-4135F. Direct inspection of the
dissolution process of the FL mini-tablets after oral administration to rats was
performed by abdominal incision studies. All of the coated FL mini-tablets
started to dissolve in the rat ileum. The dissolution sites were identified to be
proximal to the ileocecal junction for P-4135F, at the middle part of the ileum
for Eudragit S100 and at the proximal part of the ileum for Eudragit L100. NFLX
tablets with different membrane thicknesses of P-4135F were prepared and were
orally administered to beagle dogs. The colon delivery efficiency was evaluated
by measuring the Ti of NFLX into the systemic circulation. The mean Tis were
1.33+/-0.33 h for 56.8+/-0.5 microm membranes, 3.75+/-0.25 h for 64.6+/-0.7
microm membranes, 4.00+/-1.00 h for 70.5+/-0.5 microm membranes and 3.00+/-1.00 h
for 74.9+/-0.4 microm membranes. By comparing the Ti, 4.33+/-0.33 h, obtained
after oral administration of NFLX in a pressure-controlled colon delivery
capsule, and the colon arrival time, 3.5+/-0.3 h, determined by a sulfasalazine
test in beagle dogs. P-4135F coated NFLX tablets appeared to dissolve and
disintegrate before reaching the colon. Studies using rats and beagle dogs have
suggested that P-4135F dissolves in the lower part of the small intestine, i.e.,
the ileum. These studies also suggest that this new polymer will be useful for
the delivery of NFLX to the lower part of the small intestine.
PMID- 10680979
TI - Transnasal delivery of 5-fluorouracil to the brain in the rat.
AB - The purpose of this research is to clarify the feasibility and to determine the
extent of transnasal drug delivery to the brain through the cerebrospinal fluid
(CSF) in the rat, using 3H-5-fluorouracil (5FU) as a model drug. It was confirmed
first that the concentration of 5FU in the CSF was significantly higher following
nasal administration compared with intravenous injection, indicating direct
transport of 5FU from the nasal cavity to the CSF. Concentration-time profiles of
5FU in the plasma and in the cerebral cortex were determined following
intravenous infusion, nasal instillation and nasal perfusion. In order to
evaluate the extent of drug transport from the nasal cavity to the cerebral
cortex by way of the CSF, the apparent brain uptake clearances were calculated.
The uptake clearance following nasal perfusion (8.65 microl/min/g tissue) was
significantly large (p < 0.001) in comparison with that following intravenous
infusion (6.20 microl/min/g tissue), while that following nasal instillation
(6.94 microl/min/g tissue) was not. Consequently, significant amount of 5FU is
transported from the nasal cavity to the brain through the CSF and thus, the
delivery of the hydrophilic drug to the brain is augmented by nasal drug
application.
PMID- 10680980
TI - Pathogenic mechanism of acute post-streptococcal glomerulonephritis.
AB - Considerable knowledge has been accumulated regarding the characteristics of
acute post-streptococcal glomerulonephritis (APSGN), and many attempts have been
made to identify a streptococcal factor or factors responsible for triggering
this disease. However, the pathogenic mechanism behind APSGN remains largely
unknown. As glomerular deposition of C3 is generally demonstrated before that of
IgG in the disease process, it is likely that the inflammatory response is
initiated by renal deposition of a streptococcal product, rather than by
deposition of antibodies or pre-formed immune complexes. During recent years, a
number of streptococcal products have been suggested to be involved in the
pathogenic process. In this review, possible roles of these factors are discussed
in the context of the clinical and renal findings most often demonstrated in
patients with APSGN. Streptokinase was observed to be required in order to induce
signs of APSGN in mice, and a number of findings suggest that the initiation of
the disease may occur as a result of renal binding by certain nephritis
associated variants of this protein. However, additional factors may be required
for the development of the disease.
PMID- 10680981
TI - Outbreak of echovirus 30 meningitis in Switzerland.
AB - This study includes 80 patients (38 children and 42 adults) who contracted
aseptic meningitis in the summer of 1996 in Fribourg, Switzerland. Virological
studies revealed an enteroviral infection in 65 out of 70 (93%) investigated
patients. In 47 out of the 53 cases (89%) where a precise virus could be
identified, the causative agent was an Echovirus 30. More than 50 patients lived
in an area within a 5-km radius. The patients presented with the classic symptoms
and signs of aseptic meningitis. In contrast, polymorphonuclear leukocytes
predominated in the cerebrospinal fluid in the first 24 h and 32% of the cases
had a left shift in their peripheral blood smear. The patients' age did not
influence white blood cell count, the proportion of polymorphonuclear leukocytes
or protein concentration in the cerebrospinal fluid. Thirty-three patients (41%)
received antibiotic treatment, and 38 patients (48%) left the hospital within 24
h. Only 2 neuroradiological procedures and 1 electroencephalographic recording
were performed. The outcome was favourable in all patients.
PMID- 10680982
TI - Acyclovir for treatment of infectious mononucleosis: a meta-analysis.
AB - A meta-analysis of 5 randomized controlled trials (RCT), involving 339 patients
with acute infectious mononucleosis (IM) treated with acyclovir (ACV) was
performed. ACV was given intravenously in 2 RCTs, which included patients with
more severe disease, and orally in the remaining 3 RCTs, which included patients
with mild to moderate IM. Both clinical and virological endpoint data available
from RCT were evaluated in this study. There was a trend towards clinical
effectiveness of ACV treatment, but no statistically significant results were
achieved. In contrast, a significant reduction in the rate of oropharyngeal EBV
shedding was observed at the end of the therapy (overall OR: 6.62; 95% CI: 3.56
12.29; p < 0.00001). However, no difference in EBV shedding was observed 3 weeks
later. There was no significant difference on adverse events in the groups of
patients treated with ACV or placebo. In conclusion, clinical data do not support
use of ACV for the treatment of acute IM, despite good virological activity of
this drug. There is a need for more effective treatment of EBV infection.
PMID- 10680983
TI - Cytomegalovirus UL97 and glycoprotein B (gB) sequences in tissues from
immunocompromised patients with ganciclovir-resistant virus infection.
AB - The pathogenesis of ganciclovir-resistant cytomegalovirus (CMV) was investigated
by analysing UL97 and gB sequences in tissues obtained from 4 immunocompromised
patients with infections caused by ganalciclovir-resistant virus. UL97 and gB
sequences were obtained by automated sequencing of CMV DNA amplified from lysates
prepared from deparaffinized tissue sections. Patient 1 contained wild-type UL97
and gB3 sequences. Patient 2 harboured genetically distinct viruses in his lung:
one with a ganciclovir-resistance UL97 mutation and a gB3 genotype, and another
without UL97 mutations and a gB1 genotype. In patient 3, a ganciclovir-resistant
UL97 mutant virus with a gB1 genotype was cultured from the lung, whereas the CMV
in the brain did not contain mutations and its genotype was gB2. In patient 4,
ganciclovir-resistance UL97 sequences were found in oesophageal tissue prior to
the isolation of a ganciclovir-resistant CMV from the blood. All viruses in this
patient had a gB3 genotype. CMV containing ganciclovir-resistance UL97 mutations
may cause end-organ disease in immunocompromised individuals. In these subjects,
CMV circulating in the blood may have similar or different UL97 and gB genotypes
than the virus causing end-organ disease.
PMID- 10680984
TI - Inter- and intra-species karyotype variations among microsporidia of the genus
Encephalitozoon as determined by pulsed-field gel electrophoresis.
AB - Disseminated infections due to microsporidia of the genus Encephalitozoon are
detected increasingly, especially in patients with AIDS. Identification of
microsporidia can be achieved by a variety of immunological and molecular
methods. This study evaluates the feasibility of pulsed-field gel electrophoresis
(PFGE) for the analysis of karyotypes of the 3 known species of this genus
(Encephalitozoon cuniculi, Encephalitozoon hellem and Encephalitozoon
intestinalis) and of 2 of the 3 known E. cuniculi strains (strains I and III).
Eleven chromosomal DNA bands were resolved for E. cuniculi and 10 chromosomal DNA
bands for E. hellem and E. intestinalis, with molecular sizes ranging from 231 to
320 kb, from 197 to 288 kb and from 195 to 285 kb, respectively, resulting in
estimated genome sizes of about 3.0 Mb, 2.5 Mb and 2.4 Mb. Different PFGE
chromosomal banding patterns indicate that not only E. cuniculi, as previously
described, but also E. hellem, represent a heterogeneous entity. PFGE is a
valuable method of evaluating inter- and intra-species variations among
Encephalitozoon species that may enable the identification of environmental
sources of infection and modes of transmission.
PMID- 10680985
TI - Bacterial arthritis in a Swedish health district.
AB - The aim of this retrospective investigation was to study the occurrence,
characteristics and outcome of culture-positive bacterial arthritis in a Swedish
county hospital for the period 1994-97. Using registers of diagnosis, 15 adult
patients with infectious arthritis in native joints were identified.
Staphylococcus aureus was, as expected, the most common microbial agent. Six
cases were caused by direct inoculation. The risk for bacterial arthritis caused
by intra-articular steroid injection was estimated at 1/12,000. Joint damage was
seen in 6 cases. Two patients died during the infection. White blood cell count
in synovial fluid was performed in 5 cases, with median value 1.9 x 10(9)/l and,
since it was not a good predictor of infection in this study, the value of this
method for this indication is questioned.
PMID- 10680986
TI - Tuberculosis diagnosed in a surgical department during 1974-93: a report of 32
cases.
AB - During the period 1974-93, 32 patients (18 males, 14 females) with previously
undiagnosed tuberculosis were admitted to the department of surgery and the
surgical outpatient department of Buskerud Central Hospital. Of these, 26 were
native Norwegians and 6 immigrants of Asian origin with an average age of 65 and
26 years, respectively. Of the native Norwegians, 14 patients had a past history
of tuberculosis and 7 cases were associated with concomitant cancer. With 1
exception, all immigrants had extrapulmonary tuberculosis. Cultural
identification of Mycobacterium tuberculosis occurred in 28 cases and
Mycobacterium bovis in 1 (immigrant). A total of 30 patients were cured, whereas
2 of 3 patients with miliary dissemination died.
PMID- 10680987
TI - Trovafloxacin susceptibility of aerobic clinical bacterial isolates from Sweden.
AB - Trovafloxacin susceptibility was studied in aerobic clinical isolates of
bacterial pathogens from 5 microbiology laboratories in Sweden. Trovafloxacin and
ciprofloxacin minimum inhibitory concentration (MIC) determinations were
performed on 474 clinical isolates. Disk diffusion tests using trovafloxacin and
ciprofloxacin 10 microg disks were performed on a total of 7142 clinical isolates
(trovafloxacin). Susceptibility interpretations for trovafloxacin and
ciprofloxacin were determined from MIC values and disk diffusion tests using
species-related MIC-limits and zone diameter breakpoints. Eight of 12 gram
positive species groups were fully susceptible to trovafloxacin as judged by MIC
tests. Trovafloxacin gave MIC50 values of 0.032 mg/l for S. aureus, 1.0 mg/l for
MRSA, 0.064 mg/l for coagulase negative staphylococci, 1.0 mg/l for MRSE, 0.064
mg/l for S. saprophyticus, 0.125 mg/l for group A and group B streptococci, 0.064
mg/l for group C and G streptococci and S. pneumoniae, 0.25 mg/l for E. faecalis,
and 16.0 mg/l for E. faecium. These MIC values were 4-16-fold lower than those of
ciprofloxacin. Both MIC and disk tests showed similar levels of susceptibility
among gram-negative isolates for trovafloxacin and ciprofloxacin. For most gram
negative species the trovafloxacin MIC50 values were similar to or slightly
higher than those for ciprofloxacin. Trovafloxacin MIC values were much lower for
Acinetobacter strains, but higher for P. mirabilis compared with ciprofloxacin.
The favourable susceptibility levels of Swedish aerobic pathogens to
trovafloxacin emphasize the potential of this drug for the treatment of serious
infections.
PMID- 10680988
TI - Calibration of disk diffusion antibiotic susceptibility testing: species-related
trovafloxacin interpretive zone breakpoints and selection of disk potency.
AB - International comparisons of antibiotic susceptibility require the use of common
minimum inhibitory concentration (MIC) limits. Disk diffusion test results are
not directly suitable for such comparisons, since different standards are often
used and zone breakpoints issued might reflect different MIC limits. We have used
single strain regression analysis (SRA) for the calibration of the disk test,
both according to species and individual laboratory, and for quality control of
trovafloxacin disk diffusion tests in 5 laboratories in Sweden. Preliminary
controls using histogram analysis including subtraction histograms of reference
strains revealed marked differences between different laboratories. SRA was
performed on 4 reference strains, S. aureus, E. faecalis, E. coli and P.
aeruginosa, using disks containing 1, 3, 10, 30 and 100 microg trovafloxacin. The
results using SRA showed a difference between laboratories using Biodisk PDM
medium, which produced smaller zones, and those using Oxoid IsoSensitest. Species
related regression lines for laboratories using either medium were calculated and
corresponding interpretive zone breakpoints determined for MIC limits. Rational
criteria for the selection of a suitable disk content of an antibiotic were also
defined and applied to trovafloxacin. The 10 microg disk selected by NCCLS
(National Committee for Clinical Laboratory Standards) proved optimal.
PMID- 10680989
TI - Immunogenicity and safety of a tetravalent diphtheria-tetanus-acellular pertussis
inactivated poliovirus vaccine.
AB - The objective of this study was to investigate whether a tetravalent vaccine
containing diphtheria, tetanus, monocomponent acellular pertussis and inactivated
poliovirus (DTaP-IPV) was immunogenic and safe compared with the vaccination
regime used in Denmark at the time of the study. The study was performed as an
open controlled study in which 270 Danish children were enrolled at their 5
weeks' routine examination. The children were allocated to receive either (i)
DTaP-IPV (12.5 Lf, 7 Lf, 40 microg, 40, 8, 32 DU) at 3, 5 and 12 months of age (n
= 186) or (ii) DT-IPV (50 Lf, 12.5 Lf, 40, 8, 32 DU) at 5, 6 and 15 months of age
plus whole-cell pertussis vaccine (> or = 4 IU) at 5 and 9 weeks and at 10 months
of age (n = 84). No hypotonic hyporesponsive episodes or other vaccine-related
serious adverse events were seen. Local reactions, febrile and crying episodes
with the investigational vaccine (DTaP-IPV) were similar to the reactions seen
with the existing DT-IPV vaccine. One month after completing the vaccination
schedule, all children had antibodies above the defined protective antibody
concentrations to polio, tetanus and diphtheria. For pertussis toxin, there was a
significantly better response in the investigational vaccine group. We therefore
conclude that, when used according to the schedule tested, the tetravalent DTaP
IPV vaccine is safe and immunogenic. In addition, the number of visits and the
number of injections necessary are reduced with this vaccine and vaccination
schedule.
PMID- 10680990
TI - Safety and immunogenicity of combined Dtpa-IPV vaccine for primary and booster
vaccination.
AB - This study evaluated the safety and immunogenicity of combined diphtheria,
tetanus, acellular pertussis, inactivated poliomyelitis vaccine (DTPa-IPV) given
as primary immunization at ages 3, 4.5 and 6 months and a booster dose between
the ages of 18 and 27 months to healthy children. The acellular pertussis
tricomponent vaccine contains pertussis toxoid (PT), filamentous haemaglutinin
(FHA) and 69 kDa outer membrane protein (PRN). Serum immune responses to the
administered antigens were measured before and after the primary and the booster
vaccination series. The safety of the vaccine was evaluated based on diary cards
completed by parents within 4 d following each vaccination. A total of 237 and
150 children completed the primary and booster vaccination series, respectively.
A total of 483 (66.5%) and 111 (74%) local and 317 (43.7%) and 98 (65.3%) general
adverse events were reported after 726 doses of the primary series and 150 of the
booster doses, respectively. Compared with primary vaccination, the incidence of
all adverse symptoms was greater after the booster dose and a previous severe
reaction was a risk factor for a severe reaction after the booster dose (OR =
5.11). All but 1 child, who failed to have antibodies to diphtheria toxoid after
the booster dose, responded to all administered antigens with antibody titres
greater than the assay cut-off points. The combined DTPa-IPV used for primary and
booster immunization induced good immunity, but was associated with large local
reactions in 21.3% of children after the booster dose.
PMID- 10680991
TI - Subacute primary Candida lung abscess.
AB - A case of primary subacute Candida lung abscess is described. The most reliable
way to diagnose a rare pulmonary disease is to perform an open lung biopsy. A
review of the literature suggests that the diagnosis of a primary subacute
abscess due to Candida albicans in vivo is unique.
PMID- 10680992
TI - Community-acquired Staphylococcus epidermidis endocarditis complicated by splenic
disease 9 years after aortic valve replacement.
AB - We describe here a case of Staphylococcus epidermidis prosthetic aortic valve
endocarditis 9 y after valve replacement. Surprisingly, the microorganism was
community-acquired, highly virulent and associated with splenic disease. The
patient recovered following emergency valve replacement and prolonged antibiotic
therapy. Splenectomy was not required.
PMID- 10680993
TI - Endocarditis caused by drug-resistant Streptococcus pneumoniae in a child.
AB - We report a case of infective endocarditis caused by drug-resistant Streptococcus
pneumoniae. Cefazolin or cefotaxime therapy induced a partial response. Treatment
with vancomycin was successful. This microorganism may be more significant in
endocarditis in areas with a high prevalence of drug-resistant Streptococcus
pneumoniae.
PMID- 10680994
TI - Streptococcus equinus endocarditis in a patient with pulmonary histiocytosis X.
AB - Although Streptococcus equinus has been isolated from the human bowel in an
appreciable percentage of the adult general population, it has only rarely been
described as a human pathogen. Our report describes the occurrence of S. equinus
endocarditis in a patient who had no history of pre-existing heart disease, but
who showed evidence of a late-stage pulmonary histiocytosis X. Endocarditis
resolved promptly after antibiotic treatment, but required aortic valve
substitution. Abnormalities of the immune system that have been demonstrated in
patients with histiocytosis X could explain the occurrence of endocarditis in
this patient.
PMID- 10680995
TI - Leukocyte adhesion deficiency in a Norwegian boy.
AB - A Norwegian boy suffering from recurrent urinary and respiratory tract infections
was examined. It was found that granulocyte random migration, respiratory burst
activity and the proportions of CD11/CD18 receptor positive leukocytes were
reduced, consistent with a diagnosis of leukocyte adhesion deficiency. An
increased proportion of Fc gammaI-receptor-bearing granulocytes did not
compensate for the CR3 deficiency.
PMID- 10680996
TI - Praziquantel in niclosamide-resistant Taenia saginata infection.
PMID- 10680997
TI - Loss of livestock breeding efficiency due to uncompensable sperm nuclear defects.
AB - An important goal of modern analyses of semen is to elucidate the molecular
traits of mammalian sperm chromatin structural abnormalities, defined here as
'uncompensable', that lead to abnormalities in fertility, pronuclear formation,
early embryo quality and pregnancy outcome. Sperm with uncompensable nuclear
abnormalities are able to fertilize oocytes both in vivo and in vitro; however,
due to the uncompensable trait(s), the embryo development may be abnormal.
Uncompensable nuclear traits can be experimentally induced in bull sperm by a
mild thermal insult to the testis. Sperm nuclear morphology abnormalities seen in
ejaculates 11-days post stress are likely related to molecular changes in
chromatin observed 3-days post stress by the flow cytometric sperm chromatin
structure assay (SCSA). The SCSA measures the susceptibility of sperm nuclear DNA
to denaturation in situ. This susceptibility has been correlated with the
presence of DNA strand breaks that may be derived in part by oxidative stress and
possibly by a unique, abortive apoptotic mechanism. The extent of DNA
denaturation is not significantly related to the level of disulfide bonding
between the chromatin protamines. The use of human sperm with uncompensable
nuclear traits for artificial reproductive techniques is also discussed. The goal
of this research is to remove from semen doses those sperm with uncompensable
nuclear traits and thereby increase male fertility potential.
PMID- 10680998
TI - Molecular cloning of translocation breakpoints in a case of constitutional
translocation t(11;22)(q23;q11) and preparation of probes for preimplantation
genetic diagnosis.
AB - In vitro fertilization (IVF) centres with preimplantation genetic diagnosis (PGD)
programmes are often confronted with the problem of identifying chromosomal
abnormalities in interphase cells biopsied from preimplantation embryos of
carriers of a reciprocal translocation. The present authors have developed a DNA
testing based approach to analyse embryos from translocation carriers, and this
report describes breakpoint-spanning probes to detect abnormalities in cases of
the most common human translocation (i.e. the t(11;22)(q23;q11)). Screening a
yeast artificial chromosome (YAC) library for probes covering the respective
breakpoint regions in the patient lead to probes for the breakpoint on chromosome
11q23. The physically mapped YAC and bacterial artificial chromosome (BAC) clones
from chromosome 22 were then integrated with the cytogenetic map, which allowed
localization of the breakpoint on chromosome 22q11 to an interval of less than 84
kb between markers D22S184 and KI457 and to prepare probes suitable for
interphase cell analysis. In summary, breakpoint localization could be
accomplished in about 4 weeks with additional time needed to optimize probes for
use in PGD.
PMID- 10680999
TI - Kinematic definition of ram sperm hyperactivation.
AB - Although it is known that ram spermatozoa exhibit hyperactivated motility under
capacitating conditions, quantitative analyses of the head and flagellar movement
of washed ram spermatozoa have not been published. Motile spermatozoa were
recovered from semen by swim-up into HSOF medium, and their movement in 30-microm
deep chambers was videorecorded. Spermatozoa of interest were identified during
tape playback (hyperactivated spermatozoa were identified by visual assessment of
flagellar movement) and sequential head and tail images were traced onto overhead
projector film attached to the video monitor. The flagellar movement
characteristics beat angle (FBA), beat envelope (FBE) and curvature ratio (FCR)
were determined by first principles, and head centroid kinematics were determined
using Cartesian methods. Hyperactivated spermatozoa had significantly higher FBA
and FBE and significantly lower FCR values than non-hyperactivated spermatozoa
(all P<0.0001). The centroid kinematic values were also found to be significantly
different, and kinematic criteria for ram sperm hyperactivation were developed.
These criteria were refined by consideration of 60-Hz CASA-derived trajectories,
and ram sperm hyperactivation was defined by: VCL > 250.0 microm s(-1) and VSL <
or = 100.0 microm s(-1) and LTN < or = 30% and ALHmax > or = 9.0 microm.
PMID- 10681000
TI - Expression of polo-like kinase (PLK) in the mouse placenta and ovary.
AB - The polo-like kinase (PLK) is a mammalian serine/threonine kinase involved in
cell cycle regulation. Much evidence for the role of PLK in the cell cycle has
come from studies of cultured cells; however, little is known about its function
or even expression in vivo. The present study examined the features of PLK
expression in the mouse placenta and ovary. Immunohistochemical studies showed
that PLK is highly expressed in the basement membrane of the endometrial gland,
in some endothelial cells, in endometrium after embryo implantation, in
trophoblastic tissue invading the decidua, in the ovarian stroma and in some
lutein bodies. In contrast, PLK was not detectable by immunohistochemistry in
endometrial stroma before decidualization, in decidua, in trophoblastic tissue
not invading the decidua or in ovarian follicles. PLK expression seemed to be
correlated with the expression of proliferation cellular nuclear antigen (PCNA)
in many placental and ovarian cells, reflecting a role in cellular proliferation.
Nevertheless, in ovarian stroma and lutein bodies where PCNA was not expressed,
PLK was strongly expressed. This finding indicates that PLK may have some post
mitotic functions in certain specialized cell types.
PMID- 10681001
TI - Development of the membrana granulosa of bovine antral follicles: structure,
location of mitosis and pyknosis, and immunolocalization of involucrin and
vimentin.
AB - The membrana granulosa of the ovarian follicle is termed the 'follicular
epithelium', yet there have been no studies considering its epithelial nature and
how it changes during follicular development. Therefore, these issues were
investigated using histology (n = 45 ovaries), considering its structure and the
location of proliferating and dying cells, and drawing analogies with other
epithelia. Additionally, differences between the layers of granulosa cells were
demonstrated by immunohistochemistry (n = 7 ovaries). The structure of the
membrana granulosa differed between follicles. Six arbitrary classifications were
designed based on these structures, 80 follicles were allocated (n = 13 ovaries)
to these classes and the follicular diameters were then measured. For the first
time, differences in membrana granulosa structure were shown to correspond to
follicle size. Follicles in classes 1-3, where basal granulosa cells were
columnar with nuclei positioned basally in the cell, were all < or = 3 mm in
diameter. All follicles larger than 3 mm had either columnar basal cells with
nuclei positioned centrally (class 4), or had rounded basal cells (class 5), and
all follicles > 5 mm had only rounded basal cells. In all these classes, cells in
the middle zone were rounded; cells aligning the antrum were often flattened.
Irrespective of follicle class, cell proliferation and cell death were shown to
be predominantly in the middle portions, rather than the most antral or most
basal portions, of the membrana granulosa of healthy and atretic follicles.
Involucrin, a marker of keratinocyte differentiation, was localized to the
suprabasal region of the membrana granulosa of healthy follicles, particularly in
the second and third cellular layers in from the follicular basal lamina.
Conversely, the staining intensity for the intermediate filament protein vimentin
was lowest in this region, and greatest in the more antral and basal regions. In
atretic follicles, there was widespread staining for involucrin and vimentin
throughout the membrana granulosa. In conclusion, the membrana granulosa is
highly structured, and alters with follicular development. Layers in the membrana
granulosa can differ in terms of cell shape, and differ in proliferation and gene
expression. In the light of the current work, and an associated study, it is
proposed that proliferation occurs in the middle layers, and that granulosa
cells, then progress basally or antrally, the latter undergoing terminal
differentiation.
PMID- 10681002
TI - Sperm antibodies in rat models of male hormonal contraception and vasectomy.
AB - The presence of sperm antibodies correlates with nearly every pathological
condition of the male reproductive tract. In the seasonal breeder, mink, a
decrease in gonadotrophin secretion and testicular regression also induces sperm
antibodies. Because the Sertoli cells and the principal cells of the epididymis
(i.e. the cells mainly responsible for protection of germ cells from autoimmune
destruction) are dependent on androgens, and because the androgen concentration
decreases in both the testis and epididymis during male hormonal contraception,
the presence of IgG class sperm antibodies in serum was studied in rats during
the suppression and recovery phases of testosterone contraception and after
vasectomy. Five-centimetre long testosterone implants were placed under the
dorsal skin of rats under pentobarbitone anaesthesia. The control rats received
empty implants. All implants were left in the rats for 27 or 53 days. The total
number of testicular antigens detected by sera from the vasectomized rats
increased significantly until 66 days post-operation, and then decreased to the
levels of intact rats. The number of testicular antigens detected by sera from
rats receiving contraceptive doses of testosterone did not increase before the
testosterone capsules were removed, but at 40 days post removal of the silastic
capsules, the number of antigens detected by the sera was significantly higher
than in intact rats and at 77 days post removal of the silastic capsules, the
number of antigens detected by the sera was significantly higher than at 27 days
after starting testosterone administration. No significant changes in the number
of antigens detected by the sera could be observed after the implanting of empty
capsules or after their removal. Vasectomy mostly induced antibodies against
testicular antigens in the molecular ratio ranges of 70-82, 25-33 and 21-24.5 kD.
Antibodies against antigens in these molecular ratio ranges were not
significantly induced during or after treatment with contraceptive doses of
testosterone. Cell nuclei with apoptotic morphology could be observed in the
seminiferous tubules of the vasectomized rats, but DNA in situ 3'-end labelling
of testes could not confirm any differences between the testes of vasectomized
and sham-operated rats or between testosterone-treated and empty implant-treated
rats. CD3+ T cells could not be observed in the testes of any of the treatment
groups. These results suggest that the immunological conditions remain stable in
the testes after vasectomy and during testosterone treatment, but that the
animals are more prone to develop autoantibodies after vasectomy and during
recovery from treatment with exogenous testosterone.
PMID- 10681003
TI - Effects of bull, sperm type and sperm pretreatment on male pronuclear formation
after intracytoplasmic sperm injection in cattle.
AB - This study investigated the effects of the bull, sperm type (dead, immotile or
motile) and sperm pretreatment (i.e. mechanical (tail-cutting or tail-scoring) or
chemical (heparin, heparin + caffeine, calcium ionophore A23187 or
dithiothreitol)) on male pronuclear formation after intracytoplasmic sperm
injection (ICSI) in cattle. Three experiments were conducted. In Experiment 1,
spermatozoa from three bulls (A, B and C) were used for both ICSI and in vitro
fertilization (IVF). The results were that sperm from bull B yielded a higher
penetration/male pronuclear formation rate than that of bull C when used for IVF
(89.6% v 25.6%, P<0.01). However, when injected into oocytes by ICSI, sperm from
bull C had a higher male pronuclear formation rate than that of bull B (34.6% v.
16.1%, P<0.05). The effects of sperm type and mechanical pretreatment were
examined in Experiment 2. No significant difference was found in the male
pronuclear formation rate when the three types of sperm were injected into
oocytes. Tail-scored sperm achieved a higher male pronuclear rate than that of
non-mechanically treated ones (38.2% v. 13.2%, P<0.005). In Experiment 3,
chemical pretreatments were tested and compared. Higher male pronuclear rates,
compared with the control, were obtained when sperm were pretreated with heparin
+ caffeine, calcium ionophore A23187 and dithiothreitol (48.2%, 62.5% and 64.5%
v. 25.0%, P<0.05, 0.005 and 0.005, respectively). These results indicate that (1)
there is a bull variation in male pronuclear formation with ICSI, and the male
pronuclear rate by ICSI is not coincident with the results by IVF, (2)
immobilization of a spermatozoon by tail-scoring before ICSI can improve the
formation of the male pronucleus, and (3) an appropriate chemical pretreatment of
spermatozoa is necessary to achieve a higher rate of male pronuclear formation.
PMID- 10681004
TI - Effects of pre- and post-mating nutritional status on hepatic function,
progesterone concentration, uterine protein secretion and embryo survival in
Meishan pigs.
AB - This experiment examined whether the pre- or the post-mating diet had greater
impact on embryo survival in Meishan gilts. Gilts received either a maintenance
(1.15 kg day(-1); n = 12) or a high (3.5 kg day(-1); n = 12) diet during the
oestrous cycle preceding mating. After mating, half the animals in each group
received either the maintenance or the high diet until slaughter on Day 12. Gilts
fed the high pre-mating diet had more corpora lutea (22.7 v. 19.0, SED = 0.98;
P<0.001), increased embryo survival (95.5% v. 74.8%, SED = 7.58; P<0.01) and
heavier corpora lutea (-0.71 log g v. -0.90 log g, SED = 0.09; P = 0.07) compared
with gilts fed the maintenance diet prior to mating. The post-mating diet had no
effect on embryo survival. There were no treatment effects on blastocyst
developmental stage, luteal surface area or progesterone release. Gilts receiving
the high post-mating diet had heavier livers than those fed the maintenance post
mating diet (1.45 v 1.08% of total bodyweight, SED = 0.07; P<0.001), suggesting
that these gilts have a greater capacity to metabolize progesterone. Pre-mating
nutritional status therefore appears to be a greater determinant of embryo
numbers and survival than the post-mating diet.
PMID- 10681005
TI - Reversed-phase liquid chromatography of proteins and peptides using multimodal
copolymer-encapsulated silica.
AB - Multimodal copolymer-encapsulated particles for liquid chromatography were
prepared by bonding 1-octadecene and unsaturated carboxylic acids on silica
particles (5 microm diameter, 300 A pores) for liquid chromatography of proteins.
These multimodal copolymer-encapsulated particles can provide both hydrophobic
and hydrogen bonding interactions with polar compounds. The chromatographic
performance of these multimodal copolymer-encapsulated particles for peptide and
protein separations was evaluated under reversed-phase conditions. Compared with
typical C8-bonded silica, polymer-encapsulated particles were more stable in
acidic mobile phases and provided better recoveries, especially for large
proteins (Mr>0.5 x 10(6)). Totally hydrophobic polymer-encapsulated particles
were found to produce broad peaks for proteins, and significant improvements were
observed by introducing hydrophilic groups (-COOH) onto the polymer-encapsulated
surface to form a multimodal phase. For the reversed-phase liquid chromatography
of peptides and proteins, improved selectivity and increased solute retention
were found using the multimodal polymer-encapsulated particles. More peaks were
resolved for the separation of complex peptide mixtures such as protein digests
using the multimodal polymer-encapsulated particles as compared to totally
hydrophobic polymer-encapsulated particles.
PMID- 10681006
TI - Enantiomeric separation of amino alcohols on protein phases using statistical
experimental design. A comparative study.
AB - Two LC supports often used for giving enantioselective retention were tested and
compared in the reversed-phase mode using statistical experimental design. The
two supports contain two different proteins, alpha1-acid glycoprotein or
cellulase immobilised to silica particles, as the chiral selectors. The two
chromatographic columns are commercially available as Chiral-AGP and Chiral-CBH.
Twelve closely structurally related amino alcohols were used as the testing
solutes. For each column three important mobile phase descriptors, that improve
the chiral recognition, were chosen as variables and retention and separation
factors were used as responses. All the tested solutes were separated using the
two protein based supports. However, the highest enantioselectivities, i.e.,
separation factors higher than 10 were obtained using the Chiral-CBH column. The
solute structure, e.g., distance between the nitrogen atom and the chiral carbon
atom, and position as well as type of substituent in the aromatic ring highly
influence the enantioselectivity on both columns. For one of the solutes the
choice of mobile phase composition could be used to control the retention order
of the two enantiomers.
PMID- 10681007
TI - Analysis of pigmented high-molecular-mass grape phenolics using ion-pair, normal
phase high-performance liquid chromatography.
AB - A normal-phase LC method has been developed to analyze high-molecular-mass grape
phenolic compounds. Samples are prepared by first isolating phenolics using C18
SPE. The analytical method uses a silica column and gradient elution with mobile
phases of methylene chloride, methanol, formic acid and heptanesulfonic acid.
This separation enables the analysis of these compounds from grape and wine
samples in the presence of anthocyanins without extensive purification. Based on
the elution order of proanthocyanidins and anthocyanins, phenolics elute in order
of increasing molecular mass. Currently, it is not possible to identify all of
the components separated in the chromatogram.
PMID- 10681008
TI - Comparison of the performance of butanol and pentanol as modifiers in the
micellar chromatographic determination of some phenethylamines.
AB - A procedure was developed for the determination of several phenethylamines
(amphetamine, arterenol, ephedrine, phenylephrine, phenylpropanolamine,
mephentermine, methoxyphenamine, pseudoephedrine and tyramine), using micellar
mobile phases of sodium dodecyl sulfate (SDS), a C18 column and UV detection. The
drugs were eluted at short retention times with conventional acetonitrile-water
or methanol-water mobile phases. In contrast, in the micellar system, they were
strongly retained due to association with the surfactant adsorbed on the
stationary phase, and needed the addition of butanol or pentanol to be eluted
from the column. These modifiers allowed a simple way of controlling the
retention. The chromatographic efficiencies obtained with the hybrid mobile
phases of SDS-butanol and SDS-pentanol were also very high, mostly in the N=3000
7000 range, significantly greater than those achieved with a conventional
acetonitrile-methanol-water mobile phase. Butanol and pentanol yielded similar
selectivities, but the latter modifier permitted significantly shorter retention
times than butanol, and was preferred to expedite the analysis of the
pharmaceuticals. Most binary combinations of the nine phenethylamines can be
resolved with these mobile phases. A mobile phase of 0.15 M SDS-5% pentanol was
used to assay five of the phenethylamines (amphetamine, ephedrine, phenylephrine,
phenylpropanolamine and pseudoephedrine) in 22 pharmaceutical preparations, which
contained diverse accompanying compounds. The results agreed with the declared
compositions and with those obtained with a mobile phase of methanol-acetonitrile
0.05 M phosphate buffer (pH 3) 10:5:85, with no interferences and relative errors
usually below 2%. However, with the aqueous-organic mobile phase, the retention
time for phenylephrine was too low and could not be usually evaluated.
PMID- 10681009
TI - High-performance liquid chromatography of selenium compounds utilizing
perfluorinated carboxylic acid ion-pairing agents and inductively coupled plasma
and electrospray ionization mass spectrometric detection.
AB - Increasing speciation demands in clinical chemistry, toxicology and nutrition
have made the determination of the total elements in a sample inadequate; the
amount of an element and the chemical forms in which it is present need to be
known. Inductively coupled plasma mass spectrometry (ICP-MS) was used after high
performance liquid chromatographic (HPLC) separation, as was electrospray
ionization mass spectrometry (ESI-MS). The effect of variation of the number of
carbon atoms in perfluorinated carboxylic acids used as ion-pairing agents for
the separation of selenium compounds was examined. Trifluoroacetic acid (0.1%),
pentafluoropropanoic acid (0.1%) or heptafluorobutanoic acid (0.1%; HFBA) were
alternatively used as additives to methanol-water (1:99, v/v) solutions as mobile
phases. Reversed-phase HPLC-ICP-MS with 0.1% HFBA in the mobile phase allowed
more than 20 selenium compounds to be separated in 70 min in an isocratic elution
mode; the separation of natural selenium-enriched sample extracts was examined
and explained. The pH of the 0.1% HFBA solution was modified with hydrochloric
acid or ammonia and the pH of the sample extracts before injection was modified
in order to overcome unwanted double peak formation in the chromatograms of
sample extracts. Oxidations of standard gamma-glutamyl-Se-methylselenocysteine
and Se-methylselenocysteine were carried out using 30% H2O2 solution and
identifications of selenium-containing oxidation products were made using HPLC
ICP-MS and HPLC-ESI-MS. The principal organic oxidation product in both cases was
methaneseleninic acid (MeSeO2H).
PMID- 10681010
TI - Determination of halogenated mono-alcohols and diols in water by gas
chromatography with electron-capture detection.
AB - We have developed an analytical method for the detection of halogenated alcohols
in water with particular focus on 3-chloro-1,2-propanediol and 3-bromo-1,2
propanediol. In this method the target analytes are extracted from water,
derivatized with heptafluorobutyric anhydride, and then analyzed with gas
chromatography with electron-capture detection. The effects of water, pH and
seawater constituents on the method were investigated. Method detection limits
for a 5 ml aqueous sample ranged from 0.14 microg l(-1) for 2-bromo-1,3
propanediol to 1.7 microg l(-1) for 1,3-dichloro-2-propanol (1,3DCP).
PMID- 10681011
TI - Application of pressurized liquid extraction followed by gas chromatography-mass
spectrometry to determine 4-nonylphenols in sediments.
AB - A time- and solvent-saving method, pressurized liquid extraction (PLE), to
extract 4-nonylphenol (4-NP) in sediment was developed. The effects of various
operational parameters (i.e., temperature, pressure, etc.) for the quantitative
extraction of 4-NP by PLE were investigated. The analytes were then identified
and quantitated by a large-volume injection GC-MS technique. The 4-NP can be
completely extracted by methanol at 100 degrees C and 100 atm combined with 15
min static and then 10 min dynamic extraction steps (1 atm = 101,325 Pa).
Recovery of 4-NP in spiked blank kaolin samples was 98% with 5% RSD. The degrees
of recovery of 4-NP in the spiked sediment samples from a reservoir and a
polluted river were 111% with 4% RSD and 106% with 5% RSD, respectively. The
perfect applicability of PLE for 4-NP was determined after testing it with spiked
and aged samples. The extraction efficiency of the PLE was compared with
conventional Soxhlet and bath ultrasonication extraction methods using the spiked
sediment samples.
PMID- 10681012
TI - Gas chromatographic profiling and screening for phenols as isobutoxycarbonyl
derivatives in aqueous samples.
AB - An efficient method is described for the simultaneous determination of phenol and
49 substituted phenols present in aqueous samples. The method is based on the
extractive two-phase isobutoxycarbonyl (isoBOC) derivatization with subsequent
solid-phase extraction (SPE) for the direct analysis by gas chromatography (GC)
and gas chromatography-mass spectrometry (GC-MS). Phenolic hydroxyl groups in
acidic aqueous solutions were allowed to react with isobutyl chloroformate
present in the dichloromethane phase containing triethylamine. The resulting
isoBOC derivatives were then recovered by SPE using Chromosorb P in normal-phase
partition mode, followed by direct GC and GC-MS analysis. Using this combined
procedure, linear detector responses were obtained in the concentration range of
0.5-8 microg ml(-1), with correlation coefficients varying from 0.925 to 0.999
for most of the phenols studied except for 2,4-dinitorphenol (0.789). The
temperature-programmed retention index (I) sets as measured on DB-5 and DB-17
dual-capillary columns of different polarity were characteristic of each isoBOC
phenol derivative and thus, useful in the screening for isomeric phenols by I
matching only. The mass spectral patterns, exhibiting characteristic [M-100]+, [M
200]+ and [M-300]+ ions for the mono-, di- and trihydroxybezenes, respectively
with common ions at m/z 57, facilitated their rapid structural confirmation. The
present method allowed rapid screening for phenols when applied to water samples
spiked with phenols.
PMID- 10681013
TI - Determination of reducing end sugar residues in oligo- and polysaccharides by gas
liquid chromatography.
AB - Reducing end sugar residues in maltodextrins and arabinoxylans are determined as
alditol acetates by gas-liquid chromatography following reduction, acid
hydrolysis and acetylation of the samples. After this conversion to alditol
acetates, the reducing end sugars are thus separated from their acetylated aldose
counterparts. The method allows to identify individual reducing end sugars
quantitatively and is a good alternative for colorimetric reducing sugar assays
and 1H-NMR analysis. To demonstrate the advantages of the method, an application
in a study of enzymic solubilisation and degradation of water unextractable
arabinoxylan from a flour squeegee fraction is described.
PMID- 10681014
TI - Prediction of gas chromatographic retention indices of polychlorinated
dibenzothiophenes on non-polar columns.
AB - Polychlorodibenzothiophenes (PCDTs) have been found in several kinds of
environmental samples. The lack of reference compounds has meant that very little
is known about their gas chromatographic behavior. Here we discuss the retention
of 19 authentic PCDTs and their sulfones on the widely used gas chromatographic
stationary phases DB-5 and DB-5ms. The retention order is different from that of
the polychlorodibenzofurans. The data generated allowed us to carry out a
multiple linear regression to generate parameters for predicting the retention
indices of unknown congeners based only on their structural features.
PMID- 10681015
TI - One-step capillary isoelectric focusing for the separation of the recombinant
human immunodeficiency virus envelope glycoprotein glycoforms.
AB - One-step capillary isoelectric focusing was investigated as a rapid method to
resolve the glycoforms of the heterogeneous recombinant human immunodeficiency
virus (HIV) envelope glycoprotein (rgp 160sMN/LAI). The separation was performed
in a poly(vinyl alcohol) (PVA) coated capillary using a mixture of ampholyte of
narrow and wide pH range. A combination of saccaharose and 3-(cyclohexylamino)-1
propanesulfonic acid was shown to be the most efficient additive to avoid protein
precipitation which occurs at a pH close to its pI. Although the calibration
curve [isoelectric point (pI) vs. migration times] showed a non-linear
relationship, an adequate linearity could be yielded for short pI ranges
permitting to exhibit the acidic character of the different glycoforms of the rgp
160s MN/LAI (pI from 4.00 to 4.95). Reproducibility evaluated by comparing the
performance of a polyacrylamide and a PVA coated capillary showed that low RSD
values were obtained for intra-day (0.5 to 1.9%) and inter-day (1.6 to 7.6%)
measurements using the PVA capillary. Moreover, the long term stability of the
PVA capillary was demonstrated by measuring the variation of migration times of
the protein markers for a long period of use. Finally, this method was able to
differentiate the glycoform pattern of two close glycoproteins such as the rgp
160 of two sub-populations of the virus HIV-1.
PMID- 10681016
TI - Determination of pesticides in waters by automatic on-line solid-phase extraction
capillary electrophoresis.
AB - The separation of seven pesticides by micellar electrokinetic capillary
chromatography in spiked water samples is described, allowing the analysis of
pesticides mixtures down to a concentration of 50 microg l(-1) in less than 13
min. Calibration, pre-concentration, elution and injection into the sample vial
was carried out automatically by a continuous flow system (CFS) coupled to a
capillary electrophoresis system via a programmable arm. The whole system was
electronically coupled by a micro-processor and completely controlled by a
computer. A C18 solid-phase mini-column was used for the pre-concentration,
allowing a 12-fold enrichment (as an average value) of the pesticides from
fortified water samples. Under the optimal extraction conditions, recoveries
between 90 and 114% for most of the pesticides were obtained.
PMID- 10681017
TI - Immunohistochemical study of S100-like protein in Eimeria brunetti and Eimeria
acervulina.
AB - We have investigated the expression of a calcium-binding protein, the S100
protein, in Eimeria brunetti and Eimeria acervulina stages. For this purpose,
paraffin sections of distal ileum and bursa of Fabricius or duodenum from
experimentally infected chickens were treated with anti-alpha-S100 (anti-alpha
subunit of S100 protein) and anti-beta-S100 (anti-beta subunit of S100 protein)
monoclonal antibodies and anti-S100 whole molecule polyclonal antibody. The
avidin-biotin peroxidase method was used to demonstrate immunoreactivity. In the
ileum, our results reveal a positive immunoreaction for the beta subunit and S100
whole molecule within the macrogametes of E. brunetti, whereas they were devoid
of immunostaining after treatment of the paraffin sections with the anti-alpha
S100 antiserum. Schizonts and oocysts of E. brunetti and all the E. acervulina
stages gave a negative reaction after treatment with any of the three antiserum
used in the study. This result indicated that the S100 protein molecules within
these stages were not recognized by the antibodies, suggesting that these
molecules are different from those identified in macrogametes of E. brunetti. By
contrast, in the epithelial cells, lining the lumen of the bursa of Fabricius,
macrogametes of E. brunetti were stained by the three antibodies used. These
results may indicate the existence of metabolic adaptations that enable the
parasite to invade tissue sites different from those where the parasite usually
develops.
PMID- 10681018
TI - Growth performance, meat quality and activities of glycolytic enzymes in the
blood and muscle tissue of calves infected with Sarcocystis cruzi.
AB - Growth performance and the pattern of glycolytic enzymes in the blood plasma were
assessed during experimental Sarcocystis cruzi infection (1 x 10(5) sporocysts
per calf) in six calves; five calves served as noninfected controls. At slaughter
(68 or 88 days post infection), carcass weight, dressing percentages and several
parameters of meat quality (pH, color brightness, rigor, water absorbing
capacity, water binding capacity) were recorded. Moreover, enzyme activities were
measured in muscle homogenates. Weight gain was significantly impaired by the
infection. Activities of lactate dehydrogenase (LDH) and aldolase (ALD)
significantly increased in the blood plasma of the infected calves during the
chronic stage of the disease, while glucose-6-phosphate dehydrogenase (G6PDH) and
isocitrate dehydrogenase (ICDH) were not significantly altered. This was
accompanied by a significant decrease of enzyme activities in the Musculus
longissimus dorsi (LDH, ALD), in the diaphragmatic musculature (ALD, G6PDH) and
in the heart (LDH, ALD). Activities of LDH, ALD, ICDH and G6PDH were visualized
by enzyme histochemistry within the developing sarcosporidial cysts. However,
isoenzymes of parasite origin could not be demonstrated by agar-gel
electrophoresis of muscle homogenates or blood plasma. It is concluded that
sarcocystiosis of even moderate severity alters the performance of calves but not
meat quality. Leakage of glycolytic enzymes from the affected muscles is the
probable cause of increased plasma enzyme activities. Although these enzymes are
also synthesized by the parasite, the contribution of parasite-derived enzymes to
the observed changes of enzyme patterns remains in question.
PMID- 10681019
TI - Cell-mediated immune response in calves to single-dose, trickle, and challenge
infections with Fasciola hepatica.
AB - A peripheral blood mononuclear cell (PBMC) proliferation assay was used to study
the cell-mediated immune response in eight calves experimentally infected with
Fasciola hepatica. Hypersensitivity-related eosinophil and mast-cell responses
were also assessed. The primary infection of 500 metacercariae was administered
either as a single-dose or as a trickle infection over a 4-week period. Calves
were challenge-infected 4 months later with 100 metacercariae and slaughtered 24
weeks postprimary infection. Skin eosinophil counts (SEC) were determined prior
to infection on the basis of the intradermal reaction (IDR) to
phytohaemagglutinin (PHA). These counts correlated negatively with the mean fluke
length but not with the fluke burden found at necropsy. At the end of the
experiment, non-specific (PHA) and specific (excretory-secretory parasite,
products, FhESAg, and whole-worm extract, FhSomAg) immediate type
hypersensitivity IDR were elicited in contrast to delayed type hypersensitivity
(DTH) responses. The SEC correlated with blood eosinophilia but not with parasite
parameters. These findings suggest that the eosinophil response does not
correlate clearly with the development of resistance to F. hepatica infection in
cattle. A specific mononuclear cell response to FhSomAg was detectable as early
as 7 days after infection in both infected groups, being significantly higher
during the very early migratory phase of the juveniles in the single-dose
infected calves than in the trickle infected calves. This response remained
significantly higher in infected groups than in the control group throughout the
experiment. Challenge elicited a significant proliferative response, less
pronounced than after primary infection. No production of gamma-interferon (INF
gamma) was recorded 3 weeks after challenge. At necropsy, the mean number of
flukes recovered was similar in both infected groups, suggesting that the rate at
which the infection is administrated has no effect on protective immunity.
Hepatic lesions, similar in both infected groups, were characterised by marked
eosinophil and mast-cell infiltration. Liver biopsies were performed and their
diagnostic value is discussed. All results suggest that F. hepatica infection
predominantly induces a Type-2 response in cattle, and that this response has
little protective effect.
PMID- 10681020
TI - Prevalence of hydatidosis among donkeys in northern Jordan.
AB - One hundred and thirty donkeys (Equus asinus), aged between 5 months and 14 years
of age, from the Irbid Governorate in northern Jordan were necropsied between
November 1997-May 1999. Of these animals, 16.9% had hydatid cysts in either their
lungs and/or livers. No donkeys of 3 years of age or less were infected, where as
33.3% (22 of 66) aged 4 years or greater were infected. Intensity of infection
increased with age in a linear fashion. The prevalence also increased with age
approaching an asymptotic prevalence of 1 in the oldest animals. This implied
there was minimal regulation of the parasite population by intermediate host
immunity. The numbers of cysts in the donkeys were increasing at a rate of 0.48
cysts per year from 0.054 infections. The frequency distribution was highly
aggregated, consistent with a negative binomial distribution indicating infection
of donkeys was not random.
PMID- 10681021
TI - Sero-epidemiological study of Taenia saginata cysticercosis in Belgian cattle.
AB - A sero-epidemiological survey of Taenia saginata cysticercosis was carried out to
determine the prevalence of the infection in cattle presented for slaughter in
Belgium. Between November 1997 and June 1998, a total of 1164 serum samples were
collected in 20 export abattoirs. Meat inspection was routinely carried out by
veterinary inspectors. Serum samples were examined for circulating parasite
antigen using a monoclonal antibody-based sandwich enzyme-linked-immunosorbent
assay (Ag-ELISA). Thirty six serum samples (3.09%) were found positive in the Ag
ELISA, while by meat inspection on the same animals cysticerci were detected in
only three carcasses (0.26%). Sero-prevalence was positively correlated with the
age of the animals. The sero-prevalence found in this study was more than 10
times higher than the annual prevalence (0.26%) reported by the Institute for
Veterinary Inspection. This study clearly indicates that the classical meat
inspection techniques detect only a minor fraction of the carcasses infected with
cysticerci.
PMID- 10681022
TI - Seasonal development and survival of equine cyathostome larvae on pasture in
south Louisiana.
AB - Cyathostome development and survival on pasture in subtropical climates of the US
have yet to be completely defined and available data on seasonal transmission are
minimal. In an attempt to study this phenomenon, a group of pony mares and their
foals was maintained on a naturally contaminated pasture in southern Louisiana.
Fecal egg counts (FEC) and numbers of infective third stage larvae (L3) kg(-1)
dry herbage were recorded biweekly during two time periods, from January 1986
through December 1988, and September 1996 through October 1997. A FEC rise
occurred during the late summer-early autumn which preceded the peak of L3 on
pasture during the winter season. The numbers of cyathostome L3 were reduced
during the hottest months of the year due mainly to daily minimum temperatures
above 18 degrees C, and in winter during short freezing spells when daily minimum
temperatures dropped below 0 degrees C. Tilling of the pasture reduced the number
of cyathostome L3 during the early winter months but this is an efficacious
measure only if horses are given an effective anthelmintic treatment prior to
being returned to pasture. The data collected suggest that parasite reduction in
southern Louisiana is possible using a treatment program with treatment beginning
at the end of September and continuing through the end of March.
PMID- 10681023
TI - The effect of oxfendazole terminated infections with Haemonchus contortus on the
development of immunity in sheep.
AB - The relative contribution of third (L3), fourth (L4) or adult stages of
Haemonchus contortus to the development of immunity was evaluated in three groups
of sheep subjected to infections terminated by oxfendazole treatments at the L3,
L4 or adult stage. A control group did not receive immunising infections. All the
groups were challenged with 5000 L3, to evaluate the protection provided by the
different protocols. All sheep were necropsied at the end of the experiment to
count the abomasal worm burdens. A marked reduction in egg counts after challenge
infection was only observed in sheep in which the infection was terminated in the
adult stage (Group 4). A significant reduction in worm burden was also observed
in Group 4. The immunising infections and/or the challenge infection resulted in
moderately elevated IgG antibody levels against L3, L4 and adult somatic antigens
in all the groups. In contrast, a strong IgG response against H. contortus
excretory/secretory (ES) antigens was observed in the groups in which the
immunising infection was terminated in the L4 and the adult stage. An elevated
lymphocyte proliferation response against Haemonchus ES antigens was found only
in the group that had their immunising infection terminated at the adult stage.
The combined data suggest that exposure to and elicited immunological responses
to ES antigens are important for the development of immunity against H.
contortus.
PMID- 10681024
TI - Detection of Oestrus ovis and associated risk factors in sheep from the central
region of Yucatan, Mexico.
AB - A cross-sectional epidemiologic study was conducted in order to detect the
presence of and to estimate the seroprevalence of Oestrus ovis L. infection in
flocks of sheep from the central region of the state of Yucatan, Mexico. The risk
factors associated with disease were also identified. A sample size of 10 animals
per farm was used to detect seropositive animals, considering a 30% prevalence
and 95% confidence level. Blood samples of 689 sheep from 88 flocks were
collected and a questionnaire with questions about the flock and the host was
applied. The thin layer immune assay test was used. The risk factors were
screened using logistic regression procedures. 77% of the flocks had at least one
positive animal with antibodies against O. ovis. The overall seroprevalence and
standard error was 30.6 +/- 3.5%. Only flock size and sheep nose color showed
association (P < 0.05) with the disease. The odds ratios for flocks with less
than 11 and with 11 to 25 sheep, as related to herds with 25 or more sheep, were
0.74 and 1.73, respectively. Sheep with dark noses had a higher risk (OR = 1.46)
compared with sheep having light noses (P < 0.05).
PMID- 10681025
TI - Possible risk factors on Queensland dairy farms for acaricide resistance in
cattle tick (Boophilus microplus).
AB - A case control study was carried out within a cross-sectional survey designed to
investigate the management by Queensland dairy farmers of the cattle tick
Boophilus microplus. Although 199 farmers were surveyed, data on acaricide
resistance were only obtained from 66 farms. Multiple models were used to predict
the probability of acaricide resistance associated with 30 putative risk factors.
The region of the state in which the farm was located and the frequency of
acaricide application were consistently associated with acaricide resistance. The
risk of resistance to all synthetic pyrethroids (Parkhurst strain) was highest in
Central Queensland and increased when more than five applications of acaricide
were made in the previous year, when spray races were used and when buffalo fly
treatments with a synthetic pyrethroid were applied frequently. The probability
of resistance to amitraz (Ulam strain) was highest in Central Queensland,
increased when more than five applications of acaricide were made in the previous
year, and decreased on farms when a hand-spray apparatus was used to apply
acaricides to cattle. The probability of resistance to flumethrin (Lamington
strain) was highest in the Wide Bay-Burnett region.
PMID- 10681026
TI - Field observations of the host-parasite relationship associated with the common
horse bot fly, Gasterophilus intestinalis.
AB - Behavior of Gasterophilus intestinalis (Diptera: Gasterophilidae) was observed in
the laboratory and field over a period of 10 years. Mating occurred in a frenzied
manner as flies emerged from pupae. Males attempted to copulate with females that
had not fully emerged from the pupal case. Mating was never observed in the field
or near the horse. Observations suggest that fecal piles of the horse are used as
the mating site for the newly hatched flies. Activation of host-seeking behavior
was found to occur early and remain throughout the life span of the adult as it
sought multiple hosts for oviposition. Evidence is presented supporting the use
of olfaction and vision in finding the host. Interest by flies in shadows and
linear high-contrast objects was observed. Methods used by the flies to maintain
close proximity with the host are discussed including flight with the host and
avoidance of host defenses. Recapture methods were successful in determining the
time taken to reestablish at the host, and extent of travel to the host. The
presence of kairomone(s) within horse secretions is suspected.
PMID- 10681027
TI - WAAVP/Pfizer award for excellence in veterinary parasitology research. My
involvement in, and some thoughts for livestock parasitological research in
Australia.
AB - Being presented with the WAAVP Pfizer award for excellence in parasitological
research is the pinnacle of my career. In accepting I acknowledge the support
that I have received from workmates, colleagues, friends and family over the
years that I have been involved in this field of endeavour. Parasitic disease is
the most significant threat to the Australian sheep industry. A lack of
understanding of drug action, the absence of epidemiologically-based treatment
programs and incorrect or excessive chemical use has resulted in the development
of worm, lice and blowfly parasites which are resistant to most existing
chemotherapeutic compounds. During the past decade, difficulties in sustainable
control of parasitic disease, the decline in demand for wool products and
competition from less expensive synthetic fibre has halved the sheep population
and profitability of the industry. Notwithstanding this, a 'right-sized',
sustainable industry is emerging which will require effective chemotherapy to be
the cornerstone of parasite control. Chemical intervention in parasitic disease
is therefore here to stay but the paucity of new antiparasitic products in the
short term dictates that present therapeutics are all that producers will have
for the foreseeable future. This situation will necessitate innovative practices
and formulations to provide more cost effective, efficient drug performance and
to extend parasiticide life. However, the development of multiple drug resistance
and reduction in funds for parasitological research seriously compromises our
ability to confront these demands. With the patent life of all but the most
recent macrocyclic lactone (ML) compounds lapsing, low cost development of
bioequivalent generic formulations and options for innovative strategies to
increase performance and market share are eagerly sought. The key to efficient
drug use lies in a detailed understanding of the pharmacokinetic principles of
drug action and the host animal's physiological responses to identify procedures
which maximise drug availability--in essence giving the drug the best chance to
work. It is therefore evident that the how, where and why of drug exchange
between the bloodstream and the gastrointestinal tract are of such interest. Of
particular importance is identification of the kinetic and dynamic behaviour of
drug in the gastrointestinal tract (GIT) and the role of biliary secretion and
metabolic fate of biliary (and non-biliary) compounds. The extent to which
biliary secreted parent drug and/or metabolites are presented to the gut lumen,
reabsorbed as free compound or after deconjugation by large bowel bacteria, and
participate in the enterohepatic cycle is a major contributor to parasite
exposure. Integrating parasiticide disposition with host physiology, particularly
relating to such aspects as gastrointestinal function, feed intake and body
condition has demonstrated the value of 'whole body' pharmacokinetic studies to
identify processes to increase drug efficacy. Novel formulation modifications to
provide 'targeted' drug delivery including carrier technology, sustained release
devices and site-directed formulations can manipulate pharmacokinetic disposition
to direct or extend drug availability to the parasite infection. These research
directions should be undertaken as collaborative projects between research
organisations and the veterinary pharmaceutical industry. With the identification
of methods to improve drug action, emphasis must then be directed towards
effective communication for their implementation. It will be vital that
parasitologists move out of the laboratory to actively disseminate knowledge to
the producer. We are ambassadors for our profession and if we fail to communicate
well the perception, and indeed the value, of our work can be at risk.
PMID- 10681028
TI - WAAVP/Pfizer award for excellence in teaching veterinary parasitology: teaching
of veterinary parasitology--quo vadis?
AB - Some thoughts on training and recruitment of academic teachers and future trends
in teaching veterinary parasitology are presented with emphasis on the European
situation. It is underlined that research is an indispensable basis for academic
teaching. Besides a broad scientific background of the teacher, motivation and
teaching methods are also important. Many academic teachers do not receive formal
training in teaching methods. In order to improve future education, training of
staff members in teaching methods should be promoted. Quality control of teaching
and research, already established in many schools, should generally be
introduced. Teaching is mostly underestimated in relation to research. Therefore,
more weight should be placed on the former both in selecting scientists for the
career as academic teachers and in evaluating and ranking departments for their
academic activities. In the future veterinary medicine will have to cope with
profound changes in the society and the veterinary profession, and the
progressing European unification will enhance trends for internationalizing
teaching curricula. Therefore, veterinary medicine has to reconsider the teaching
subjects and methods and to lay more emphasis on flexibility, skills of problem
solving and self-learning and on training for life-long learning. At present
there is an ongoing discussion on the question how to teach veterinary medicine,
including veterinary parasitology. There are various options, and some of them
are discussed, namely, the disciplinary and the problem-based/organ-focussed
approaches. It is concluded that for teaching of veterinary parasitology and
related disciplines a combined disciplinary and problem-based approach offers the
best chances for fulfilling the requirements of teaching for the future. In the
curriculum of undergraduate teaching of veterinary medicine at least 70-90 h
should be dedicated to veterinary parasitology using a disciplinary and taxonomic
approach. Additional hours are required for instructions on clinical cases in
approaches focussed on animal species and/or organ diseases. As there is a need
for discussing teaching issues, post-graduate specialization, and continuing
education in parasitology and related disciplines on national and international
levels, it is recommended to WAAVP to include regular workshops on teaching in
the programmes of the biannual conferences, and to establish a permanent
committee which should collect information and submit proposals for improvement
of teaching veterinary parasitology.
PMID- 10681029
TI - Performance of the ELISA test for swine cysticercosis using antigens of Taenia
solium and Taenia crassiceps cysticerci.
AB - Studies were conducted to evaluate antigens of Taenia solium (Tso) and Taenia
crassiceps (Tcra) cysticerci in the ELISA test for the diagnosis of swine
cysticercosis. The samples analyzed were cysticercosis positive and negative
control sera and heterologous sera. Four antigens were assayed: vesicular fluid
(VF) and crude (T) Tcra and scolex (S) and crude (T) Tso. All antigens showed
good performance, but VF-Tcra was the best followed by T-Tcra. Sensitivity rates
of ELISA were respectively, in 2nd and 3rd standard deviation cut-offs, 96.0 and
80.0% for the VF antigen and specificity of 97.5 and 100.0%. Cross-reactivity was
verified only for hidatidosis and ascaridiosis. Due to the high performance
observed, the ELISA test using Tcra antigens should be recommended for the
diagnosis of swine cysticercosis.
PMID- 10681030
TI - Canine echinococcosis: an alternative for surveillance epidemiology.
AB - The essential activities for programmes of cystic echinococcosis control are the
census of all dogs from the program and identification of parasitised animals.
Currently, in South America evaluations and epidemiological surveillance are
based on the administration of arecoline hydrobromide. This method has the
disadvantage of increasing environmental pollution and risk for operators and
owners of treated dogs. A genus-specific ELISA capture method has been employed
for recently issued faeces and the confirmation of positive examination was
performed by dog autopsies. Our work presents an alternative method based on
collection of dry field-dispersed faeces, followed by serological diagnosis by
Copro-ELISA and confirmation by Copro-Western blot. If Copro-ELISA were used to
define positive samples of dry faeces, the Copro-Western blot assay would provide
70% sensitivity and 100% specificity. Global efficiency of the system using dry
faeces would reach 76%, allowing epidemiological surveillance to be oriented to
analysis of surface units instead of dog as measurement unit.
PMID- 10681031
TI - Cooperia pectinata and C. punctata, parasites of the abomasum of cattle in
northern Cameroon (Central Africa).
AB - Cooperia pectinata Ransom, 1907 and C. punctata von Linstow, 1907 are common
trichostrongyles of zebu cattle in Africa. Their intestinal localization within
the digestive tract is considered by many authors to be exclusive. Nevertheless,
some limited surveys in Malagasy, Mauritania, The Gambia and Cameroon reported
the presence of both Cooperia species in the abomasum. The present survey was
carried out in a slaughterhouse of northern Cameroon on 17 zebu cattle and
confirms the infection of the small intestine and the abomasum by the two species
within the total number of cattle examined. Abomasal infections especially with
Cooperia punctata were heavier than those in the intestine. Due to the movements
of herdbreeders in Central Africa, and to the preliminary results obtained in
Mauritania, The Gambia, Burkina Faso and Malagasy, abomasal localization of C.
pectinata and C. punctata may be encountered in very large areas of Africa, and
that cooperiosis may contribute together with Haemonchus species to the digestive
disorders involving the abomasum.
PMID- 10681032
TI - The efficacy of levamisole, and a mixture of oxfendazole and levamisole, against
the arrested stages of benzimidazole-resistant Haemonchus contortus and
Ostertagia circumcincta in sheep.
AB - Sheep were allowed to graze pasture that had been seeded with benzimidazole
resistant Haemonchus contortus and Ostertagia circumcincta in order to acquire a
burden of arrested larvae. Following housing, sheep were dosed orally with either
oxfendazole at a dose rate of 4.7 mg/kg (to confirm the benzimidazole-resistant
status of the species of nematode), levamisole at a dose rate of 7.5 mg/kg, or an
oxfendazole/levamisole mixture at a dose rate of 4.6 mg/kg oxfendazole and 8.1
mg/kg levamisole. The efficacies of the treatments were assessed by estimation of
the arrested larval burden in the abomasum of each sheep, either at 10 or 11 days
(oxfendazole and oxfendazole/levamisole mixture), or 12 or 13 days (levamisole),
after treatment. Compared to the untreated controls, the protection afforded by a
single dose of either levamisole or the oxfendazole/levamisole mixture was >99%
against the arrested stages of both Haemonchus contortus and Ostertagia
circumcincta. Treatment with oxfendazole confirmed the benzimidazole-resistance
status of the two species.
PMID- 10681033
TI - Hypolipemia associated with the wasting condition of rabbits infected with
Strongyloides papillosus.
AB - Rabbits develop a wasting condition in the intestinal stage of Strongyloides
papillosus infection. Serum inflammatory cytokine and lipid profiles were
investigated in five rabbits infected with S. papillosus and five uninfected pair
fed controls to ascertain whether the disease is inflammatory cytokine-mediated
cachexia. Tumor necrosis factor alpha (TNF alpha) was detected in one infected
animal at Day 7 after infection. Interleukin (IL)-1 was detected in three
infected, and one control, animals at Day 28. IL-6 remained unchanged in both the
groups. Infected animals developed hypolipemia, including hypotriglyceridemia in
the intestinal stage of infection. Control animals lost body weight in the same
manner as the infected animals, but had elevated cholesterols and phospholipids
with normal triglyceride concentrations. The results suggested that the wasting
condition has no association with cachexia induced by TNF alpha. IL-1 or IL-6,
and that hepatic function for lipid synthesis is affected during the intestinal
stage of S. papillosus infection.
PMID- 10681034
TI - Variability of resistance in goats infected with Haemonchus contortus in Brazil.
AB - The variability between and within breeds with respect to nematode egg counts
(EPG), packed cell volume (PCV) and hemoglobin (Hb) was studied in 36 yearling
female goats of the Caninde (15), Bhuj (6) and Anglo-Nubian (15) breeds, exposed
to Haemonchus contortus. Nematode-free goats were turned to a contaminated
paddock in late February. From then on, fecal egg per gram counts (EPG), packed
cell volume (PCV) and hemoglobin (Hb) were determined at 2-week intervals up to
Week 18. The EPG, transformed as [log(EPG + 75)], varied (P < 0.01) between goats
within breeds and between weeks of exposure, but not between goat breeds (P >
0.05). PCV and Hb were affected by goat breeds (P < 0.05), by goats within breeds
(P < 0.01) and by weeks of exposure (P < 0.01). Anglo-Nubians had higher (P <
0.01) PCV and Hb than Caninde; Bhuj had intermediate values. There were two EPG
rises; one between Weeks 6 and 10 and the other between Weeks 14 and 16. The
within breed variability was marked during the EPG rise on Week 6, when
individual egg counts ranged from 130 to 2500. The EPG rises coincided with drops
in Hb. PCV presented a similar trend, though not as marked. Haemonchus was
responsible for more than 95% of nematode eggs counted. Considering the goat as
experimental unit, the correlation coefficients (r) were: -0.45, P = 0.0064,
between log(EPG + 75) and PCV; and -0.53, P = 0.0009, between log(EPG + 75) and
Hb. The negative correlation between egg counts and blood values suggested breed
differences in PCV and Hb were related to resistance to H. contortus infection
and/or to its effects.
PMID- 10681035
TI - Use of detomidine hydrochloride as an adjunct for studying first-stage
Gasterophilus intestinalis (Diptera: Gasterophilidae) in the tongue of the horse.
AB - A synthetic alpha-2 adrenergic agonist, detomidine hydrochloride, was used in the
study of in vivo activity of Gasterophilus intestinalis (Diptera:
Gasterophilidae) during migration in the tongue of the horse. Use of the drug
allowed the investigator to manipulate the tongue and closely observe the
movement patterns and tissue disturbance caused by burrowing first-stage larvae.
Detomidine hydrochloride should be utilized in studies of drug efficacy and
larval biology, whenever possible, to avoid the need to sacrifice the horse.
PMID- 10681036
TI - Two-step purification method of vitellogenin from three teleost fish species:
rainbow trout (Oncorhynchus mykiss), gudgeon (Gobio gobio) and chub (Leuciscus
cephalus).
AB - A two-step purification protocol was developed to purify rainbow trout
(Oncorhynchus mykiss) vitellogenin (Vtg) and was successfully applied to Vtg of
chub (Leuciscus cephalus) and gudgeon (Gobio gobio). Capture and intermediate
purification were performed by anion-exchange chromatography on a Resource Q
column and a polishing step was performed by gel permeation chromatography on
Superdex 200 column. This method is a rapid two-step purification procedure that
gave a pure solution of Vtg as assessed by silver staining electrophoresis and
immunochemical characterisation.
PMID- 10681037
TI - Two-step fast protein liquid chromatographic purification of the Serratia
marcescens hemolysin and peptide mapping with mass spectrometry.
AB - The pore forming toxin of Serratia marcescens (ShlA) is secreted and activated by
an outer membrane protein (ShlB). Activation of inactive ShlA (termed ShlA*) by
ShlB is dependent on phosphatidylethanolamine (PE). Activation may be a covalent
modification of ShlA. To test this hypothesis, the responsible activation domain
(in the N-terminal 255 amino acids of ShlA) was isolated from whole bacteria with
8 M urea in an inactive form (ShlA-255*) and from the culture supernatant in an
active form (ShlA-255), followed by a two-step purification by anion-exchange
chromatography and gel permeation chromatography. Comparison of a tryptic peptide
map of both forms with subsequent electrospray mass spectrometry (ES-MS) and
sequencing by tandem ES-MS revealed no modification. These data imply that ShlB
presumably imposes a conformation on ShlA-255 that triggers activity.
PMID- 10681038
TI - Preparative two-step purification of recombinant human basic fibroblast growth
factor from high-cell-density cultivation of Escherichia coli.
AB - Aggregation and precipitation are major pitfalls during bioprocessing and
purification of recombinant human basic fibroblast growth factor (rh-bFGF). In
order to gain high yields of the soluble protein monomer with high biological
activity, an efficient downstream process was developed, focussing on the
combination of expanded bed adsorption (EBA) and heparin chromatography. After
expression in E. coli TG1:plambdaFGFB, cells were harvested and washed; then the
rh-bFGF was released via high pressure homogenization. The high viscosity of the
feedstock of about 40 mPa s, showing non-newtonian behaviour, was reduced to 2
mPa s by the addition of DNase. The homogenate (5.6 l) was loaded directly on an
expanded bed column (C-50) packed with the strong cation-exchanger Streamline SP.
In the eluates, histone-like (HU) protein was identified as the main protein
contaminant by sequence analysis. The thermodynamics and kinetics of rh-bFGF
adsorption from the whole broth protein mixture were determined in view of
competition and displacement effects with host-derived proteins. Optimal binding
and elution conditions were developed with knowledge of the dependence of rh-bFGF
adsorption isotherms on the salt concentration to allow direct application of
eluates onto Heparin HyperD. This affinity support maintained selectivity and
efficiency under CIP and over a wide range of flow-rates; both is advantageous
for the flexibility of the purification protocol in view of a scalable process.
Remaining DNA and HU protein were separated by Heparin HyperD. The endotoxin
level decreased from approximately 1,000,000 EU/ml in the whole broth to 10 EU in
3 mg bFGF per ml. The final purification protocol yields >99% pure rh-bFGF as
judged from SDS-PAGE and MALDI-TOF mass spectrometry with high mitogenic activity
(ED50=1-1.5 ng/ml) of the lyophilized sample. In comparison to the conventional
process, the overall protein recovery rose by 15% to 65% with saving time and
costs.
PMID- 10681039
TI - Purification of the Ca2+-binding protein S100A1 from myocardium and recombinant
Escherichia coli.
AB - S100A1 is a new regulatory protein of myocardial contractility that is
differentially expressed in early and late stages of myocardial hypertrophy. In
order to further investigate the multiple functions of S100A1 in various assay
systems we developed a new strategy for isolating biologically active S100A1
protein. After EDTA extraction of myocardium or recombinant bacteria, S100A1 was
purified by Octyl-Sepharose hydrophobic interaction chromatography and HiTrapQ
anion-exchange chromatography yielding 1.4-2.0 mg/100 g wet tissue and 0.7-1.0
mg/100 ml bacterial culture. Native porcine as well as human recombinant S100A1
revealed biological activity in physiological and biochemical assays.
PMID- 10681040
TI - Multi-step purification strategy for RANTES wild-type and mutated analogues
expressed in a baculovirus system.
AB - RANTES (regulated on activation, normal T cell expressed and secreted), a C-C
chemokine, is one of the major HIV-suppressive factors produced by CD8+ T cells.
Wild-type RANTES and genetically modified analogues were expressed in a
baculovirus system and purified from cell culture supernatants employing a multi
step strategy based on affinity and RP-HPLC. Quantification and purity control of
the final proteins were carried out by capillary electrophoresis using the
synthetic or the recombinant wild-type RANTES as a reference. The procedure here
reported requires only three days to obtain 0.016-0.270 mg of the pure and
characterised proteins, starting from 370-900 ml of culture media, and is
suitable for the analysis of a large number of RANTES analogues.
PMID- 10681041
TI - Purification of the c-erbB2/neu membrane-spanning segment: a hydrophobic
challenge.
AB - High quality purification of membrane-spanning peptides and proteins remains a
challenging problem. In this work we describe a tailored chromatographic
purification of a synthetic 35-residue peptide corresponding to the transmembrane
region of the tyrosine kinase receptor c-erb2/neu. Composed to over 70% by the
amino acids alanine, isoleucine, leucine, phenylalanine and valine, this peptide
presents a very hydrophobic character. Product isolation from the complex peptide
mixture, obtained after acid cleavage of the resin matrix used during the solid
phase synthesis, represents a difficult task. We propose a three step strategy
based on gel permeation and reversed-phase high-performance liquid
chromatography, using aprotic polar solvent mixtures. The challenge consisted in
obtaining a sufficient amount of an extremely pure sample, in order to allow
structural analysis by NMR spectroscopy. Keeping trace of the synthetic peptide
throughout the different purification steps was assured by MALDI TOF mass
spectrometry, and the final product purity was checked by coupled liquid
chromatography-ESI TOF mass spectrometry.
PMID- 10681042
TI - Chromatographic purification of the C(H)2 domain of the monoclonal antibody
MAK33.
AB - The C(H)2 domain, one of the constant domains of the murine monoclonal antibody
MAK33 (immunoglobulin subtype K/IgG1) was expressed in Escherichia coli forming
insoluble inclusion bodies (IBs) and purified by a three-step process including a
denaturation-renaturation step, hydrophobic interaction and gel permeation
chromatography. After disrupting the cells, the soluble protein fraction was
removed by several centrifugation steps. The isolation of the IBs from the cell
fragments was achieved by solubilizing the IBs with 6 M guanidinium hydrochloride
(GdmCl) and 0.1 M 1,4-dithioerythrit (DTE) to reduce all disulfide bonds. After
refolding the C(H)2 domain, 1.5 M (NH4)2SO4 was added to the protein solution in
order to precipitate contaminations. Then the protein was loaded on a Butyl
Sepharose fast flow column and eluted with a linear gradient [1.5-0 M (NH4)2SO4].
As the last purification step a gel permeation chromatography was run on a
Superdex 75 prep grade. Finally, the purity of the C(H)2 protein was determined
by a silver-stained sodium dodecyl sulfate polyacrylamide gel. We achieved a
typical yield of 0.5 mg pure protein per 1 g of wet cells.
PMID- 10681043
TI - Three-step purification of a fragment of the large immunophilin FKBP52.
AB - PPIases catalyze the interconversion of cis and trans isomers of peptidyl-prolyl
(Xaa-Pro) bonds in peptide and protein substrates. The PPIase family comprises
three subfamilies, two of which interact with immunosuppressant drugs and are
therefore termed immunophilins. One subgroup of the immunophilins are the FK506
binding proteins (FKBPs). FKBPs of a relative molecular mass higher than 40 000
also display chaperone activity and are part of the multichaperone complex that
Hsp90 forms with substrate proteins. Their function in this chaperone complex is
still enigmatic. To further characterize the function of FKBP52 we want to
analyze constructs of FKBP52-fragments. Here we describe a fast and effective
three-step purification procedure for a fragment of FKBP52 with a relative
molecular mass of 48000, termed FKBP52-123, consisting of affinity
chromatography, anion-exchange column and gel-permeation chromatography. A yield
of 1 mg pure protein per gram of cells was achieved.
PMID- 10681044
TI - Purification of a viral coat protein by an engineered polyionic sequence.
AB - Virus-like particles composed of the polyoma coat protein VP1 were produced as a
central building block of an artificial vector system for gene therapy. For this
purpose, recombinant VP1 was expressed in E. coli. Classical purification schemes
resulted only in low yields of protein. Therefore, we developed a new affinity
purification procedure. We decided to use a polyionic sequence containing eight
glutamic acid residues which allows efficient purification using ion-exchange
chromatography. This peptide was inserted in a solvent exposed loop on the
surface of VP1. After recombinant expression and cell lysis the first
purification and concentration step consisted of a fractionated ammonium sulfate
precipitation. The resuspended VP1 was loaded on an anion-exchange column.
Elution with ca. 600 mM NaCl yielded almost homogeneous protein. Subsequently a
size exclusion chromatography was performed to separate the pentameric VP1 from
higher oligomeric and aggregated material. In contrast to wildtype VP1 the highly
charged mutant form showed no significant tendency to aggregate. To demonstrate
the functional state of the VP1 mutant, the in vitro assembly was investigated.
At conditions similar to those for wildtype VP1 assembly, the mutant protein
could form homogeneous virus-like particles.
PMID- 10681045
TI - Expression, purification and biological properties of the carboxyl half part of
the HTLV-I surface envelope glycoprotein.
AB - The carboxyl half of the surface envelope protein of HTLV-I contains the major
immunodominant and neutralizable domains. Using two affinity chromatography steps
and a combination of high salt concentration and non-ionic detergent, we purified
this part of the envelope protein from Escherichia coli. Analysis of some
immmunological and biological properties of this protein indicated that it was
folded in a way that preserved the correct structure of this domain of the HTLV-I
envelope protein. It could be utilized in structural studies to further
understand the mechanisms of HTLV-I entry and to better define the component(s)
of an effective vaccine.
PMID- 10681046
TI - Purification of respiratory syncytial virus F and G proteins.
AB - Respiratory syncytial virus (RSV) is the most important cause of severe lower
respiratory tract infections of infants in industrial nations. In addition, the
participation of RSV in the genesis of asthma is under discussion. The RSV
glycoproteins F and G have key positions in the viral pathogenesis. At present no
satisfactory protein purification protocols are available for these proteins. The
methods published for the G protein using preparative SDS-PAGE or immunoaffinity
chromatography yield only small amounts of purified G protein that has partially
lost its antigenicity. We describe a three-step purification protocol for these
glycoproteins. RSV-infected HEp-2 cells were lysed by a Triton X-100 containing
buffer. The viral proteins were captured by QAE-Sephadex A-50 material in a batch
procedure. A first elution with 100 mM NaCl led to a crude F protein fraction,
and a second elution with 300 mM NaCl led to a crude G protein fraction. The F
protein was further purified on a Lentil-lectin Sepharose 4B column and finally
polished using a Resource Isopropyl column. Lentil-lectin Sepharose 4B was also
used to purify the G protein from the crude fraction, but polishing of the G
protein was carried out on a Resource Q column. Homogenous RSV-F and RSV-G
proteins were obtained by this protein purification protocol. No loss of
antigenicity could be observed during this procedure as the highly purified viral
proteins remain detectable by a set of monoclonal antibodies and specific
antisera. The G protein was isolated as a 90000 monomer, whereas the purified F
protein was recovered as a functional homodimer of 140000.
PMID- 10681047
TI - Three-step purification of bacterially expressed human single-chain Fv antibodies
for clinical applications.
AB - We have obtained a cell line which secretes a human monoclonal IgM (B7) reacting
with the myosin heavy chain of human heart. We have constructed single-chain
fragments (scFv) of B7. The scFv may be useful for the imaging of myocardial
necrosis after myocarditis, cardiac drug toxicosis or graft rejection. The aim of
our work was to purify the scFv for immunoscintigraphy. We describe several
purification steps including immobilized metal affinity chromatography (IMAC),
anti-c-myc monoclonal antibody affinity chromatography, size-exclusion
chromatography with Superdex 75 HR 10/30 and ion-exchange chromatography (mini Q
TM 30Q).
PMID- 10681048
TI - Purification of the membrane binding domain of cytochrome b5 by immobilised
nickel chelate chromatography.
AB - The purification of a eukaryotic membrane protein has been achieved using a
prokaryotic expression system. Bovine cytochrome b5 is an integral membrane
protein (Mr approximately 16500). It comprises of a globular haem containing
catalytic domain positioned at the N-terminus of the protein and a hydrophobic
membrane binding segment at the C-terminus. The membrane binding domain (MBD) is
resistant to purification using conventional strategies that have proved
successful in isolating the soluble haem containing fragment. We report here a
versatile purification method for the isolation of the MBD involving a gene
fusion system. The fusion protein incorporates thioredoxin at the amino terminus
and six histidines as the metal affinity binding site followed by cytochrome b5
in a pET expression system. This supports high level expression of cytochrome b5
in E. coli C43(DE3) cells. The fusion protein is effectively solubilised from
lysed cells with Triton X-100. A step gradient elution with imidazole under non
denaturing conditions on a His-Bind nickel chelate affinity column, saturated
with proteins as a crude cell extract, purified the protein in a single step.
Proteolytic digestion of pure fusion protein, with trypsin, yielded the MBD. This
fragment was further purified by RP-HPLC to a final yield of approximately 10
mg/l.
PMID- 10681049
TI - Novel, rapid purification of the membrane protein photosystem I by high
performance liquid chromatography on porous materials.
AB - New porous materials have been tested for their potential to speed up
purification of membrane proteins. As an example the purification of photosystem
I, a light-driven electron pump from the cyanobacterium Synechocystis PCC6803,
was optimized. The combination of two HPLC steps (an anion-exchange
chromatography followed by a hydrophobic interaction chromatography) yields
homogeneous monomeric or trimeric photosystem I as determined by gel filtration
and gel electrophoresis. In comparison to traditional purification schemes our
method is at least three-times faster and allows for easy scale-up.
PMID- 10681050
TI - Three-step chromatographic purification procedure for the production of a his-tag
recombinant kinesin overexpressed in E. coli.
AB - A kinesin gene has been cloned by RT-PCR (reverse transcription polymerase chain
reaction) from Trypanosoma brucei and the corresponding protein overexpressed as
a recombinant His-tag (histidine-tag) kinesin in E. coli in order to study its
biochemical properties and to determine its three-dimensional structure by X-ray
crystallography. Starting from several liters of culture, an ultrasonic
homogenizer was used for cell disruption and an unclarified feedstock was
obtained. From this homogenate, a protein was then purified by immobilized metal
affinity chromatography (IMAC) using expanded bed adsorption (EBA) technology
(Streamline chelating). For this capture step, 100% of the recombinant protein
was purified with more than 90% of purity. This step was followed by ion-exchange
chromatography (Q Sepharose Fast Flow) for intermediate purification (96% purity,
53% recovery) and by size-exclusion chromatography with Superdex 75 as a
polishing step (99% purity, 93% recovery). We then separated two forms of
kinesin, a dimer (70%) and a monomer (30%). It was then possible to purify His
tag recombinant protein directly from feedstock in a rapid and efficient way and
to isolate two forms of kinesin.
PMID- 10681051
TI - Improved purification of the membrane-bound hydrogenase-sulfur-reductase complex
from thermophilic archaea using epsilon-aminocaproic acid-containing
chromatography buffers.
AB - A hydrogenase-sulfur reductase (SR) complex was purified from membrane
preparations of the extremely thermophilic, acidophilic archaeon Acidianus
ambivalens using a combination of sucrose density gradient centrifugation and
column chromatography (FPLC). All chromatographic steps were performed in the
presence of 0.5% epsilon-aminocaproic acid resulting in the elution of the SR
complex as a sharp peak. In contrast, chromatography using buffers without
epsilon-aminocaproic acid, or in the presence of detergents, were not successful.
The purified A. ambivalens SR complex consisted of at least four subunits with
relative molecular masses of 110000, 66000, 39000 and 29000, respectively. A
similar procedure was applied to purify the membrane-bound hydrogenase from
Thermoproteus neutrophilus, a non-related extremely thermophilic but neutrophilic
archaeon, which consisted of only two subunits with relative molecular masses of
66000 and 39000, respectively.
PMID- 10681052
TI - Highly efficient purification of porcine diamine oxidase.
AB - Diamine oxidase (DAO) is a member of the class of copper-containing amine
oxidases and catalyzes the oxidative deamination of histamine and other biogenic
amines. The enzyme from porcine kidney was purified by consecutive chromatography
on concanavalin A Sepharose, heparin Sepharose and Mono Q. Besides being simpler
and faster than previous methods, this new purification scheme results in a
homogenous product with a considerably higher yield and allows the rapid
purification of large amounts of DAO from mammalian tissues. The availability of
sufficient pure protein will greatly facilitate future studies of the structure
and function of the enzyme.
PMID- 10681053
TI - Development of a downstream process for the isolation of Staphylococcus aureus
arsenate reductase overproduced in Escherichia coli.
AB - Arsenate reductase (ArsC) encoded by Staphylococcus aureus arsenic-resistance
plasmid pI258 reduces intracellular As(V) (arsenate) to the more toxic As(III)
(arsenite). In order to study the structure of ArsC and to unravel biochemical
and physical properties of this redox enzyme, wild type enzyme and a number of
cysteine mutants were overproduced soluble in Escherichia coli. In this paper we
describe a novel purification method to obtain high production levels of highly
pure enzyme. A reversed-phase method was developed to separate and analyze the
many different forms of ArsC. The oxidation state and the methionine oxidized
forms were determined by mass spectroscopy.
PMID- 10681054
TI - Purification of recombinant hydantoinase and L-N-carbamoylase from Arthrobacter
aurescens expressed in Escherichia coli: comparison of wild-type and genetically
modified proteins.
AB - Two enzymes, hydantoinase (HyuH) and L-N-carbamoylase (HyuC), are required for
the biocatalytic production of natural and unnatural, optically pure L-amino
acids starting from D,L-5-monosubstituted hydantoins using the so called
'hydantoinase-method'. For the preparation of immobilized enzymes, which omit
several drawbacks of whole cell biocatalysts, purified or at least enriched HyuH
and HyuC have to be provided. In order to simplify existing purification
protocols several genetically modified derivatives of HyuH and HyuC from
Arthrobacter aurescens DSM 3747 have been cloned and expressed in E. coli. A
fusion protein consisting of maltose-binding protein (MalE) and HyuH resulted in
an enhanced solubility of the hydantoinase, which easily forms inclusion bodies.
On the other hand the fusion protein could easily be purified with high yield
(76%) by just one chromatographic step (amylose resin) and the complex
purification protocol of the wild-type enzyme could therefore be simplified and
shortened significantly. Interestingly, the specific activity of the MalE-HyuH
fusion protein was as high as the wild-type enzyme despite that the molecular
mass was doubled. A second modification of HyuH carrying a histidine-tag was
efficiently bound to a metal affinity matrix but inactivated completely during
elution from the column at either low pH or in the presence of imidazole. In the
case of HyuC, an aspartate-tag has been added to the biocatalyst to allow an
integrated purification-immobilization procedure since this enzyme is immobilized
efficiently only via its carboxylic groups. The diminished isoelectric point of
the Asp-tagged HyuC resulted in a simplified purification procedure. Compared to
the wild-type enzyme expressed in E. coli HyuC-Asp6 was shifted off the elution
range of the contaminating proteins and higher purification factors were obtained
even in the capturing step. In contrast to HyuH, it was possible to purify a L-N
carbamoylase carrying a histidine-tag to apparent homogeneity using immobilized
metal affinity chromatography. Therefore, the existing three step purification
protocol was reduced to one chromatographic step and the yield of this relatively
unstable protein enhanced remarkably.
PMID- 10681055
TI - Purification of a D-hydantoinase using a laboratory-scale streamline phenyl
column as the initial step.
AB - A D-hydantoinase from Thermus sp. was overexpressed in Escherichia coli and
purified to homogeneity for subsequent crystallization. The purification was
performed with hydrophobic interaction chromatography as the capture step
followed by anion-exchange chromatography and gel permeation chromatography as
intermediate purification and polishing steps, respectively. The hydrophobic
interaction step was done in fluidized bed mode in a laboratory-scale Streamline
column made from conventional laboratory equipment. The whole purification
protocol could be finished within one day. The purified enzyme crystallizes. The
crystals are suitable for X-ray protein structure analysis and diffract to at
least 2.3 A resolution. Complete data sets have been measured up to 2.6 A
resolution. The X-ray structure is currently being solved.
PMID- 10681056
TI - D-Xylose metabolism by Candida intermedia: isolation and characterisation of two
forms of aldose reductase with different coenzyme specificities.
AB - To study individual enzyme components responsible for the initial step of D
xylose utilisation by the yeast Candida intermedia, a two-step protocol has been
developed that enables clear-cut separation and isolation of two structurally
similar but functionally different aldose reductases (ALRs) in high yield. In the
first step, the yeast cell extract is fractionated efficiently by biomimetic
chromatography using the dye HE-3B (reactive Red 120) as pseudoaffinity ligand
coupled to Sepharose CL-4B. In the second step, optimised high-resolution anion
exchange chromatography using Mono Q yields purified ALR1 and ALR2 in overall
yields of 63 and 62%, respectively. ALR1 is strictly specific for NADPH (2.4 x
10(5) M(-1) s(-1)) whereas ALR2 utilises NADH and NADPH with similar specificity
constants of approximately 2-4 x 10(5) M(-1) s(-1). Both enzymes are dimers with
a subunit molecular mass of 36000 but they differ in pI and the number of
titratable sulphydryl groups in the native protein. The chromatographic procedure
identifies microheterogeneity in recombinant aldose reductase from Candida tenuis
overexpressed in Escherichia coli.
PMID- 10681057
TI - Purification of surface-associated urease from Helicobacter pylori.
AB - Helicobacter pylori colonizes the human gastric mucosa and produces large amounts
of urease. The enzyme was extracted from the bacteria by distilled water and
purified by gel-permeation (Sephacryl S-300), anion-exchange chromatography (Mono
Q) and a second gel-permeation (Superdex 200). Urease enzyme activity was
detected with a spectrophotometic assay based on phenol red. The optimal pH for
anion-exchange was 6.9. The recovery of urease was 55-75%, purity 93-98% and the
overall protein recovery 0.8-1.4%. The urease in the final extract still had
enzymatic activity and showed the typical subunits of Mr 66000 and Mr 30000 when
subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
PMID- 10681058
TI - Expression of chymotrypsin(ogen) in the thioredoxin reductase deficient mutant
strain of Escherichia coli AD494(DE3) and purification via a fusion product with
a hexahistidine-tail.
AB - A reliable protocol was designed for fast expression and purification of
recombinant chymotrypsin(ogen). The zymogen was overexpressed in soluble form as
a (His)6-fusion construct in the cytoplasm of the thioredoxin reductase deficient
Escherichia coli strain AD494(DE3). This allowed purification of chymotrypsinogen
in a highly selective affinity chromatography capture step using a Ni-NTA column.
After activation with enterokinase, the enzymatically active chymotrypsin was
purified in a polishing step using a modified soybean trypsin inhibitor agarose
column. This expression system and the use of affinity chromatography for capture
and polishing, offers an easier and faster route to recombinant
chymotrypsin(ogen) than the previously described use of Saccharomyces cerevisiae.
PMID- 10681059
TI - Refolding and purification of a urokinase plasminogen activator fragment by
chromatography.
AB - A fragment of recombinant urokinase plasminogen activator (u-PA), was expressed
in E. coli in the form of inclusion bodies. Purification and renaturation was
achieved in a three-stage process. Capture of the inclusion bodies was achieved
by coupling wash steps in Triton X-100 and urea with centrifugation. Solubilised
inclusion bodies were then renatured by buffer exchange performed by size
exclusion chromatography (SEPROS). Use of size-exclusion media with higher
fractionation ranges resulted in an increase in the recovery of u-PA activity, to
a maximum fractionation range of Mr 10000-1500000 after which recovery is
reduced, due to a low resolution between the refolded u-PA and denaturant.
Fractions of refolded u-PA were concentrated using cation ion-exchange
chromatography, which selectively binds correctly folded u-PA. The result is
concentrated, active, homogeneous u-PA.
PMID- 10681060
TI - Purification of human adenosine deaminase for the preparation of a reference
material.
AB - The goal was to optimise a purification procedure of adenosine deaminase from
human erythrocytes for the preparation of a European Reference Material.
Adenosine deaminase was purified from human erythrocytes with a specific activity
of 4.46 microkat/mg of protein and a catalytic concentration of 133 microkat/l.
The isolation and purification procedure involved ion-exchange chromatography
(STREAMLINE DEAE), and two purine riboside affinity chromatographies. The
purified enzyme exhibits a single band in SDS-PAGE with a molecular weight of
41600 g/mol, and three bands in PAGE, isoelectric focusing and two-dimensional
electrophoresis with pI 4.7, 4.85 and 5.0.
PMID- 10681061
TI - Pullulanase from the hyperthermophilic bacterium Thermotoga maritima:
purification by beta-cyclodextrin affinity chromatography.
AB - This is the first report about the isolation of a type I pullulanase from a
hyperthermophilic bacterium, Thermotoga maritima strain MSB8. Purification of the
enzyme from a cleared cell-free extract was achieved by anion-exchange
chromatography and beta-cyclodextrin affinity chromatography. Using this
convenient two-step method we have purified the pullulanase 406-fold with a 26%
yield. The purified enzyme displayed maximum pullulan hydrolysis at pH 5.9 and 90
degrees C (15-min assay) and was remarkably resistant against thermoinactivation,
having a half-life at 90 degrees C of about 3.5 h. To our knowledge, the T.
maritima pullulanase is the most thermostable type I pullulanase known to date.
The affinity-based purification protocol described here may be useful for the
efficient isolation of other pullulanases.
PMID- 10681062
TI - Single-step purification of a recombinant thermostable alpha-amylase after
solubilization of the enzyme from insoluble aggregates.
AB - The expression of the gene encoding a thermostable alpha-amylase (EC 3.2.1.1)
(optimal activity at 100 degrees C) from the hyperthermophilic archaeon
Pyrococcus woesei in the mesophilic hosts Escherichia coli and Halomonas elongata
resulted in the formation of insoluble aggregates. More than 85% of the
recombinant enzyme was present within the cells as insoluble but catalytically
active aggregates. The recombinant alpha-amylase was purified to homogeneity in a
single step by hydrophobic interaction chromatography on a phenyl superose column
after solubilization of the enzyme under nondenaturing conditions. The enzyme was
purified 258-fold with a final yield of 54%.
PMID- 10681063
TI - Technique for a rapid and efficient purification of the SHV-1 and PSE-2 beta
lactamases.
AB - A simple procedure is described which results in an optimised resolution in
molecular sieve chromatography. A sample exhibiting a large initial volume (about
20 ml) and conditioned in a buffer of low ionic strength (<20 mM) by filtration
through a 53-ml G25 molecular sieve column, is adsorbed on a 1.7-ml ion-exchange
(SOURCE) column. The proteins are released by a 10-ml pulse of 1 M NaCl and the
eluate directly injected onto a 120-ml Sephacryl S100-HR column. The very low
volume of the eluate ensures optimal conditions and resolution for the molecular
sieving process. The method is applied as the polishing step in the purification
of the SHV-1 and PSE-2 beta-lactamases. It could easily be scaled up for the
treatment of larger samples.
PMID- 10681064
TI - Purification of the fengycin synthetase multienzyme system from Bacillus subtilis
b213.
AB - The purification of the multienzyme system producing the lipodecapeptide fengycin
in Bacillus subtilis b213 was investigated. By gel filtration of a cell free
extract of this organism three enzyme fractions were obtained from which five
multifunctional components of fengycin synthetase were separated by high
resolution anion-exchange FPLC procedures. These proteins were characterized by
their thioester formation activities with 14C-labeled substrate amino acids and
by N-terminal sequencing. Correlation of these data with the DNA sequences of the
pps (fen) operons in three B. subtilis strains provided detailed knowledge on the
structural and functional organization of fengycin synthetase.
PMID- 10681065
TI - New approach for separating Bacillus subtilis metalloprotease and alpha-amylase
by affinity chromatography and for purifying neutral protease by hydrophobic
chromatography.
AB - Proteases are commonly used in the biscuit and cracker industry as processing
aids. They cause moderate hydrolysis of gluten proteins and improve dough
rheology to better control product texture and crunchiness. Commercial bacterial
proteases are derived from Bacillus fermentation broth. As filtration and
ultrafiltration are carried out as the only recovery steps, these preparations
contain also alpha-amylase and beta-glucanase as the main side activities. The
aim of this study is to purify and characterize the Bacillus subtilis
metalloprotease from a commercial preparation, in order to study separately the
impact of the protease activity with regards to its functionality on biscuit
properties. Purification was achieved by means of affinity chromatography on
Cibacron Blue and HIC as a polishing step. Affinity appeared to be the most
appropriate matrix for large scale purification while ion exchange chromatography
was inefficient in terms of recovery yields. The crude product was first loaded
on a Hi Trap Blue column (34 microm, Pharmacia Biotech); elution was carried out
with a gradient of NaCl in the presence of 1 mM ZnCl2. This step was only
efficient in the presence of Zn cations, because this salt promoted both protease
stabilization resulting in high recovery yields and also complexation of amylase
units into dimers resulting in amylase retention on the column and a better
separation of the 3 activities. Beta-glucanase was mostly non retained on the
column and a part was coeluted with the protease. This protease fraction was then
loaded on a Resource Phe column (15 microm, Pharmacia Biotech) in a last step of
polishing. Elution was carried out with a linear gradient of 100-0% ammonium
sulfate 1.3 M; protease was eluted at the beginning of the gradient and well
separated from amylase and glucanase trace impurities. The homogeneity of the
purified protease was confirmed by SDS-PAGE, which showed that its MW was about
38. pH and temperature optima were also determined on the fraction.
PMID- 10681066
TI - Purification and characterization of an aminopeptidase from the chloroplast
stroma of barley leaves by chromatographic and electrophoretic methods.
AB - Aminopeptidases catalyze the cleavage of amino acids from the amino terminus of
protein or peptide substrates. Although some aminopeptidase activities have been
found in plant chloroplasts, the identity of these proteins remains unclear. In
this work, we report the purification to apparent homogeneity of a soluble
aminopeptidase from isolated barley chloroplasts which preferentially degraded
alanyl-p-nitroanilide (Ala-pNA). After organelle isolation in a density gradient
and precipitation of soluble proteins with ammonium sulfate, the proteins were
purified in three consecutive steps including hydrophobic interaction, gel
permeation and ion-exchange chromatographies. The purified enzyme appeared as a
single band with a Mr of approximately 84000 in sodium dodecyl sulfate
polyacrylamide gel electrophoresis analysis. The Mr of the native enzyme was
estimated to be approximately 93000 by gel permeation chromatography, suggesting
that the protein is a monomer. Mass spectrometry analysis of tryptic digests
indicates that the primary structure of the protein has not been reported
previously. The enzyme was characterized as a metalloprotease as it could be
totally inhibited by 1,10-phenanthroline. Strong inhibition could also be
observed using the specific aminopeptidase inhibitors amastatin and bestatin.
Besides Ala-pNA, the purified protein could also cleave with decreasing activity
glycyl-pNA, leucyl-pNA, lysyl-pNA, methionyl-pNA and arginyl-pNA. The possible
physiological role of this enzyme in the chloroplast stroma is discussed.
PMID- 10681067
TI - Three-step chromatographic purification of Cpr6, a cyclophilin from Saccharomyces
cerevisiae.
AB - Cyclophilins constitute a group of peptidyl-prolyl cis-trans isomerases (PPIs),
known to be involved in protein folding. Because of their ability to bind the
immunosuppresant drug Cyclosporin A (CsA), they are also called immunophilins.
Immunophilins, which exhibit a relative molecular mass higher than 40 000, are
further found in complex with Hsp90, a major cytosolic molecular chaperone. The
present work describes a three-step chromatographic purification of recombinant
Cpr6, a cyclophilin from Saccharomyces cerevisiae. The cDNA of Cpr6 was cloned
into a pRSET A-plasmid with an N-terminal 6 x histidine-tag (his-tag) and
transformed into the BL21[DE3]pLysS strain. After collection of the bacterial
material and lysis of the cells the cell lysate was centrifuged and loaded onto a
metal chelating column. After extensive washing the protein was eluted with a
step gradient from 20 to 250 mM imidazol. The pooled protein was dialysed against
ethylenedinitrilo tetraacetic acid (EDTA)-buffer, and loaded onto a strong anion
exchanger. Cpr6 containing fractions were then, in a last step, loaded onto a gel
permeation chromatography column. The purity of the resulting protein was
measured by silver stained sodium dodecyl sulphate-polyacrylamide gel
electrophoresis (SDS-PAGE) and, additionally, as Cpr6 does not contain tryptophan
residues by tryptophan residue titration. Based on a standard curve the content
of contaminating tryptophan residues in the purified protein solution was
determined. A typical yield of 1 mg pure protein per g of wet cells was achieved
with the described procedure.
PMID- 10681068
TI - Are isoprostanes a clinical marker for antioxidant drug investigation?
AB - Numerous pathological conditions are suspected to involve free radical production
as part of their pathogenic process. Therefore, a pharmacological control of
oxidative stress could probably benefit many vascular, inflammatory or
degenerative diseases. However, the development of antioxidant drugs and their
clinical evaluation are limited by the absence of an accurate, reliable and easy
to-handle marker of tissue oxidative events. Isoprostanes (isoPs), a
prostaglandin-related series of metabolites, are emerging as major candidates for
clinical measurement of oxidative stress. They are chemically stable products of
lipid peroxidation, formed in cellular membranes and subsequently released and
excreted in the urine. Many recent clinical studies have reported that urinary
and plasma levels of isoPs (in particular the iPF2alpha-III isomer also called 8
epi-PGF2alpha) are increased in clinical conditions where oxidative stress is
suspected to play a pathogenic role. Moreover, isoPs have been detected in tissue
extracts from atherosclerotic plaques and Alzheimer patients brain tissue.
Finally, antioxidant treatments such as vitamin E supplementation appear to
reduce isoPs levels in biological fluids of treated patients. These preliminary
observations argue for a further investigation of isoPs as a practical
pharmacodynamic endpoint for the clinical evaluation of antioxidant therapies.
PMID- 10681069
TI - Effects of non-ionic monomeric and dimeric iodinated contrast media on renal and
systemic haemodynamics in rats.
AB - Non-ionic dimeric contrast media (CM) are a new class of CM which are iso-osmolar
with plasma. The aim of this study was to investigate their effects on systemic
and renal haemodynamics. The non-ionic dimeric CM iodixanol and the non-ionic
monomeric agent iobitridol (both at a dose of 1,600 mgI/kg) were compared in
terms of their effects on systemic blood pressure (BP) and renal blood flow (RBF)
in two strains of rats (Wistar and Sprague Dawley). Iodixanol significantly
lowered BP in Wistar rats (-33 +/- 9% of baseline, 10 min post-injection, P <
0.001 vs. saline and iobitridol). Iobitridol had virtually no effect on BP.
Iobitridol and iodixanol significantly decreased RBF. This effect was more marked
following injection of the dimer rather than the monomer (iodixanol: -32 +/- 13%
iobitridol: -20 +/- 4 of baseline at 16 min, P < 0.05). For both agents, RBF was
still decreased 50 min following injection (iodixanol: -30 +/- 11%, and
iobitridol: -20 +/- 5% of baseline). Iodixanol also decreased RBF in Sprague
Dawley rats, while BP remained unchanged. This suggests that changes in BP/RBF
autoregulation do not account for the renal haemodynamic effects of this agent.
When measured 2 h following injection, the iodixanol-induced renal hypoperfusion
was still detectable (-29% vs. saline-treated rats), although not significant (P
= 0.06). This effect was no longer observed 4 h following injection. Increasing
the saline infusion rate (18 mL/h vs. 2 mL/h) during the experiment did not
significantly decrease the effects of iodixanol on BP and RBF in Wistar rats. In
spite of its iso-osmolality, iodixanol, a non-ionic dimeric CM, depressed RBF and
BP significantly more than iobitridol, a monomeric non-ionic agent, in Wistar
rats. This effect was long-lasting and was not alleviated by increasing the
hydration rate.
PMID- 10681070
TI - Detection of salicylate and its hydroxylated adduct 2,3-dihydroxybenzoic acid in
glutamate neurotoxicity and the effects of verapamil and ryanodine in rats.
AB - It has been suggested that salicylate hydroxylation can be used to detect
hydroxyl radical formation in vivo. In the present study we investigated the
effects of verapamil and or ryanodine on salicylate (SA) and its hydroxylated
adduct; 2,3-dihydroxybenzoic acid (2,3-DHBA) levels in glutamate induced
neurotoxicity of whole rat brains. To detect SA and 2,3-DHBA, an HPLC-EC/UV
method was used. Retention time was found to be 3.9 min for 2,3-DHBA and 12.0 min
for SA. Verapamil at 10(-5) and 10(-7) and ryanodine at 10(-5) M concentrations
were found to have a significant decreasing effect on this degradation induced by
glutamate. This was the highest dose for ryanodine tested. As an L-type voltage
dependent calcium channel blocker, verapamil was found ineffective at 10(-4), 10(
6) and 10(-8) M concentrations. Surprisingly, none of the combined application
groups (verapamil + ryanodine) was found effective on SA hydroxylation. As a
result, ryanodine was effective only at the highest dose, while verapamil exerts
its effect in a dose dependent fashion as reported before in the literature.
PMID- 10681071
TI - Role of the endothelium on the response to adrenoceptor agonists of rabbit aorta
during cooling.
AB - The role of the endothelium in the effects of cooling on the response to alpha1-
and alpha2-adrenoceptor agonists of rabbit aorta was studied. The contractions
induced by clonidine (10(-9)-3 x 10(-4) M) and xylazine (10(-7)-10(-3) M) but not
phenylephrine (10(-9)-3 x 10(-4) M) and methoxamine (10(-9)-3 x 10(-4) M) were
enhanced in endothelium-denuded or N(G)-nitro-L arginine methyl- ester (L-NAME)
(10(-5) M) pretreated rabbit aorta. The sensitivity, but not the maximal
response, of both alpha1- and alpha2-adrenoceptor agonists was significantly
lower at 28 degrees C (cooling) than at 37 degrees C. Endothelium removal did not
affect the action of cooling. These results were taken as evidence for the
specificity of alpha2-adrenoceptor agonists on the production and release of
nitric oxide from vascular endothelium. The results suggest that the endothelium
seems to have no role in the cooling-induced responses of both alpha1- and alpha2
adrenoceptors.
PMID- 10681072
TI - Comparison of the efficacy and safety of losartan (50-100 mg) with the T-type
calcium channel blocker mibefradil (50-100 mg) in mild to moderate hypertension.
AB - The objective of this study was to compare the antihypertensive efficacy and
safety of losartan and mibefradil. 324 outpatients (57 +/- 9.2 years) with mild
to moderate hypertension were randomly allocated in a double-blind fashion to
receive 50 mg of losartan or mibefradil once daily p.o. for 6 weeks after 2 weeks
of placebo run-in. Titration was then forced to 100 mg of losartan or mibefradil
for an additional 6 weeks. Patients were assessed at baseline, 6 and 12 weeks.
The primary efficacy variable was change in predose sitting diastolic (SDBP) and
systolic (SSBP) blood pressure at 12 weeks. Secondary variables included change
in mean 24-hour ambulatory blood pressure and comparison of safety and
tolerability. Both treatments lowered SSBP and SDBP at 6 and 12 weeks (week 6:
mibefradil -14/-9 mm Hg; losartan -12/-7 mm Hg) (P <0.001). The primary
objective, a difference between treatments in reduction of SSBP and SDBP at week
12 could be demonstrated (mibefradil -22/-16 mm Hg; losartan -16/-10 mm Hg)
(P=0.003 and P=0.001, respectively). Twenty-four-hour SBP and 24-hour DBP were
reduced (P<0.001) within each treatment group at weeks 6 and 12. The secondary
objective, a difference between treatments in reduction of 24-hour blood pressure
at week 12 could be demonstrated (P<0.001). Twenty-four-hour heart rate was
lowered in the mibefradil group at weeks 6 and 12 (P < 0.001). Responder rates at
6 and 12 weeks were 56.2% and 78.5% for mibefradil versus 56.1% and 55.3% for
losartan (P = 0.001). Both treatments were equally well tolerated. This study
demonstrates that 50 mg losartan is comparably effective to 50 mg mibefradil in
the treatment of mild to moderate hypertension with 100 mg mibefradil being more
potent than losartan.
PMID- 10681073
TI - Criteria for vascular dementia: replacing dogma with data.
PMID- 10681074
TI - Alzheimer disease: mouse models pave the way for therapeutic opportunities.
AB - Research into the molecular mechanisms of Alzheimer disease (AD) continues to
clarify important issues in aberrant protein processing while seeking to identify
therapeutic targets. Mutations of genes on chromosomes 1, 14 (presenilins 1 and
2), and 21 (the amyloid-beta [Abeta] amyloid precursor protein [APP]) cause the
familial forms of AD that often begin before age 65. An allelic polymorphism on
chromosome 19 (apolipoprotein E ) affects the age of onset of the more common
forms of sporadic AD. Multiple studies in transgenic mice provide strong evidence
to support the view that Abeta amyloid formation is an early and critical
pathogenic event: mice expressing pathogenic human APP mutations develop Abeta
deposits; coexpression of mutant presenilin genes accelerates the rate of Abeta
deposition; and apolipoprotein E plays a role in this process. Thus, the 3
established genetic causes or risk factors for AD affect Abeta deposition. The
fact that elevation of the Abeta42/Abeta40 ratio (differing only in 2 amino acids
in length) is also linked to amyloid deposition in the APP mice and is temporally
linked to cognitive impairment suggests that Abeta42 may be a principal inducing
factor of AD. The exact sequence of events is still unknown, but the transgenic
models generated so far have shown their usefulness in clarifying this complex
part of the pathology. The continuing progress in elucidation of the molecular
pathogenesis of AD suggests a range of rational pharmacological interventions for
this disorder. The most promising strategy involves the development of approaches
to retard, halt, or prevent Abeta-mediated disease progression, and these can now
be tested in transgenic animals.
PMID- 10681075
TI - Cortical and subcortical interhemispheric interactions following partial and
complete callosotomy.
PMID- 10681076
TI - Clinical criteria for the diagnosis of vascular dementia: a multicenter study of
comparability and interrater reliability.
AB - BACKGROUND: Several clinical criteria have been developed to standardize the
diagnosis of vascular dementia (VaD). Significant differences in patient
classification have been reported, depending on the criteria used. Few studies
have examined interrater reliability. OBJECTIVE: To assess the concordance in
classification and interrater reliability for the following 4 clinical
definitions of VaD: the Hachinski Ischemic Score (HIS), the Alzheimer Disease
Diagnostic and Treatment Centers (ADDTC), National Institute of Neurological
Disorders and Stroke-Association Internationale pour la Recherche et
l'Enseignement en Neurosciences (NINDS-AIREN), and Diagnostic and Statistical
Manual of Mental Disorders, Fourth Edition (DSM-IV). METHODS: Structured
diagnostic checklists were developed for 4 criteria for VaD, 2 criteria for
Alzheimer disease (AD), and 4 criteria for dementia. Twenty-five case vignettes,
representing a spectrum of cognitive impairment and subtypes of dementia, were
prepared in a standardized clinical format. Concordance in case classification
using different criteria and interrater reliability among 7 ADDTCs given a
specific set of criteria was assessed using the kappa statistic. RESULTS: The
frequency of a diagnosis of VaD was highest using the modified HIS or DSM-IV
criteria, intermediate using the original HIS and ADDTC criteria, and lowest
using the NINDS-AIREN criteria. Scores for interrater reliability ranged from
kappa = 0.30 (ADDTC) to kappa = 0.61 (original HIS). CONCLUSIONS: Clinical
criteria for VaD are not interchangeable. Depending on the criteria selected, the
reported prevalence of VaD will vary significantly. The traditional HIS has
higher interrater reliability than the newer criteria for VaD. Prospective
longitudinal studies with clinical-pathological correlation are needed to compare
validity.
PMID- 10681077
TI - Effects of bilateral posteroventral pallidotomy on gait of subjects with
Parkinson disease.
AB - BACKGROUND: Most studies documenting the effect of pallidotomy on parkinsonian
gait have reported unilateral surgery and used qualitative scales or timed tests
that only provide measures of walking speed. OBJECTIVE: To document the effect of
bilateral posteroventral pallidotomy on the walking patterns of patients with
Parkinson disease (PD). DESIGN: Case series of gait evaluations performed 1 month
before and 1 month after surgery, with antiparkinson medication withheld for 8
hours overnight. SETTING: Movement analysis laboratory of a clinical research
center. PATIENTS: Consecutive sample of 8 men and 3 women with a diagnosis of PD
scheduled for bilateral pallidotomy. INTERVENTION: Bilateral posteroventral
pallidotomy. MAIN OUTCOME MEASURES: A 3-dimensional motion-capture system allowed
calculation of temporal and spatial measurements and joint angular displacements
of the lower extremities and trunk during gait. RESULTS: Pallidotomy
significantly increased average walking speed from 0.214 statures/s
preoperatively to 0.440 statures/s postoperatively (where stature indicates body
height) (P = .03). A faster postoperative walking speed was achieved almost
exclusively by increasing average stride length from 0.24 to 0.47 statures (P =
.03) rather than changing average gait cycle time (1.32 to 1.37 seconds; P =
.08). A forward stepwise multiple regression analysis (P<.001) revealed that 96%
of the change in stride length postoperatively could be explained by the
combination of changes in foot-floor angle, knee, and hip excursion during gait.
CONCLUSIONS: Bilateral posteroventral pallidotomy was associated with a 2-fold
increase in walking speed. Previous studies have demonstrated that walking speed
is an important indicator of locomotor performance and level of disability in
patients with PD, so the increase in postoperative walking speed likely provided
a functional benefit.
PMID- 10681078
TI - Striatal dopamine transporter binding assessed by [I-123]IPT and single photon
emission computed tomography in patients with early Parkinson's disease:
implications for a preclinical diagnosis.
AB - BACKGROUND: Specific binding to dopamine transporters may serve as a tool to
detect early loss of nigrostriatal dopaminergic neurons in patients with
Parkinson's disease. OBJECTIVE: To determine striatal dopamine transporter
binding using the cocaine analogue [I-123]N-(3-iodopropen-2-yl)-2beta
carbomethoxy-3beta-(4-chl orophenyl) tropane ([I-123]IPT) and single photon
emission computed tomography. PATIENTS AND METHODS: We studied 9 control subjects
(mean age, 58 years; range, 41-69 years) and 28 patients with early Parkinson's
disease (Hoehn and Yahr stages I [n = 14] and II [n = 14] [symptom duration, <5
years]; mean age, 55.5 years; range, 36-71 years). Single photon emission
computed tomography was performed 90 minutes after injection of 120 to 150 MBq of
radioactive [I-123]IPT. RESULTS: Specific striatal [I-123] IPT binding (mean +/-
SD) was significantly reduced in patients with early Parkinson's disease
(ipsilateral striatum: 4.09+/-0.97; range, 2.46-6.40; contralateral striatum:
3.32+/-0.76; range, 1.80-5.13) compared with controls (left striatum: 7.28+/
0.94; range, 5.78-8.81; right striatum: 7.41+/-1.28; range, 5.58-9.44). IPT
binding ratios (mean +/- SD) were significantly lower in patients with Hoehn and
Yahr stage II (ipsilateral striatum: 3.47+/-0.75; contralateral striatum: 2.96+/
0.73) compared with those with Hoehn and Yahr stage I (ipsilateral striatum:
4.72+/-0.75; contralateral striatum: 3.69+/-0.61) (P<.001). The ipsilateral
striatum of patients with Hoehn and Yahr stage I showed a significant mean+/-SD
reduction of IPT binding (ipsilateral striatum: 4.72+/-0.75) compared with either
right or left striatum of controls (P<.001). Only in 1 patient was IPT binding to
the ipsilateral striatum (ratio, 6.40) higher than the lowest value observed in
the striatum of a control subject (ratio, 5.58). CONCLUSIONS: Use of [I-123] IPT
and single photon emission computed tomography demonstrates a reduction of
dopamine transporter binding in patients with early Parkinson's disease.
Significantly reduced IPT binding already observed in the ipsilateral striatum of
patients with Hoehn and Yahr stage I demonstrates the potential of this method to
detect preclinical disease.
PMID- 10681079
TI - Association between angiotensin-converting enzyme and Alzheimer disease.
AB - BACKGROUND: Angiotensin-converting enzyme has been reported to show altered
activity in patients with neurologic diseases. An insertion-deletion polymorphism
in ACE has recently been linked to heart disease, cerebrovascular disease, and
AD. OBJECTIVE: To determine whether the angiotensin-converting enzyme (ACE) is
associated with risk of Alzheimer disease (AD). METHODS: We investigated the ACE
polymorphism as a potential risk factor for AD in 151 patients with AD and 206
ethnically matched controls from Russia and in 236 patients with AD and 169
controls from North America by means of allele association methods and logistic
regression. RESULTS: None of the ACE genotypes was associated with increased
susceptibility to AD in the total sample or in subsets stratified by
apolipoprotein E gene (APOE) epsilon4 status. However, the D allele was more
frequent among AD cases between ages 66 and 70 years compared with controls in
both the Russian (P = .02) and North American (P = .001) datasets. In this age
group, the effect of D (odds ratio, 11.2; 95% confidence interval, 2.9-44.0)
appeared to be independent of and equal or greater in magnitude to the effect of
APOE epsilon4 (odds ratio, 7.8; 95% confidence interval, 3.5-7.4). CONCLUSIONS:
Our results suggest that APOE and ACE genotypes may be independent risk factors
for late-onset AD, but the ACE association needs to be confirmed in independent
samples in which the time and extent of vascular cofactors can be assessed.
PMID- 10681080
TI - A novel missense mutation (W797R) in the myophosphorylase gene in Spanish
patients with McArdle disease.
AB - OBJECTIVE: To investigate the degree of genetic heterogeneity of myophosphorylase
deficiency (McArdle disease) in Spain through molecular studies of 10 new
patients. DESIGN: The coding sequence of the entire myophosphorylase gene was
sequenced in DNA extracted from muscle and blood. Restriction fragment length
polymorphism analysis of polymerase chain reaction fragments was used to confirm
and simplify detection of a novel mutation. SETTING: A collaborative study
between 2 university laboratories in Spain and the United States. RESULTS: Five
of the 10 patients harbored a novel missense mutation in exon 20, converting a
tryptophan to an arginine (W797R). Three patients were homozygous for the
"common" R49X mutation, and the remaining 2 patients were compound heterozygotes
for R49X and a previously described missense mutation, G204S. CONCLUSIONS: The
W797R missense mutation is the third novel mutation to be identified among
Spanish patients. Its relative frequency suggests that it should be added to the
R49X mutation in the molecular screening of McArdle disease in Spain.
PMID- 10681081
TI - Intracranial volume and Alzheimer disease: evidence against the cerebral reserve
hypothesis.
AB - BACKGROUND: Total intracranial volume (TIV) measurement commonly is used to
correct for variations in premorbid brain size in imaging studies of cerebral
structures in Alzheimer disease (AD). This assumes no intrinsic difference in TIV
between patients and control subjects and that TIV measurements are unaffected by
cerebral atrophy. However, an autopsy study has suggested that a larger premorbid
brain may protect against AD onset. A recent computed tomographic study lent
support to this by finding a correlation between intracranial size and age at
onset of AD in women. OBJECTIVE: To investigate the relationship between TIV and
sporadic and familial AD. DESIGN: Retrospective case study. SETTING: Specialist
dementia clinic. PATIENTS: Eighty-five patients with AD and 52 healthy
volunteers. MAIN OUTCOME MEASURES: Age at symptom onset and TIV measured using a
semiautomatic interactive thresholding technique on magnetic resonance imaging
spanning the entire intracranial cavity. RESULTS: Reproducibility measurement was
high (intrarater coefficient of variation, 1.2%; interrater coefficient of
variation, 0.7%). Unlike brain atrophy in the patients with AD, TIV did not vary
over time. Mean TIV did not differ significantly between any of the subject
groups. There was no association between TIV and age or age at symptom onset. The
only significant predictor of TIV was sex. CONCLUSIONS: Measurements of TIV are
independent of atrophy and can be used safely to adjust for differences in head
size in studies of cerebral structure in AD. Premorbid brain size does not differ
between patients with familial and sporadic AD and controls and does not delay
disease onset.
PMID- 10681082
TI - Differences between Pick disease and Alzheimer disease in clinical appearance and
rate of cognitive decline.
AB - OBJECTIVES: To define the cognitive characteristics of Pick disease (PcD), and to
determine which features distinguish PcD from Alzheimer disease (AD), in a cross
sectional and longitudinal study. METHODS: The participants were 44 patients with
PcD (10 pathologically verified), 121 patients with AD (14 pathologically
verified), and 60 normal control subjects. We obtained information regarding the
initial symptom of dementia from each patient's caregiver, estimated global
dementia severity by the Blessed Dementia Scale and the Activities of Daily
Living Scale, and assessed specific cognitive domains by administering 10 tests
of memory, language, visuospatial, and reasoning abilities and selective
attention. RESULTS: Among initial symptoms reported by caregivers, personality
change and language impairment were significantly more common in PcD than AD;
deficits in memory were common in both groups but more prevalent in AD (P<.001).
At initial cognitive testing, the scores of patients with PcD were inferior to
those of normal controls on all tests, except on a measure of visuospatial
function; the scores of patients with AD were inferior to those of controls on
all tests. Patients with PcD were superior to patients with AD on measures of
explicit memory (P<.001) and visuospatial function (P = .001) but had greater
impairments on the Activities of Daily Living Scale (P<.05). During the course of
illness, patients with PcD declined significantly faster than those with AD on
language tests and on global measures of dementia severity (P<.05), whereas
measures of explicit memory and visuospatial and reasoning abilities worsened
equally in both patient groups. CONCLUSIONS: There is a characteristic cognitive
profile and course of dementia in PcD. Nonetheless, cognitive test performance
does not clearly distinguish PcD from AD.
PMID- 10681083
TI - Lack of an association of estrogen receptor alpha gene polymorphisms and
transcriptional activity with Alzheimer disease.
AB - BACKGROUND: Long-term cognitive decline in postmenopausal women is associated
with aging and Alzheimer disease (AD). Estrogen replacement therapy has been
reported to reduce the risk of developing AD. The distribution of estrogen
receptors (ERs) in neurons overlaps that of the brain neurons known to develop
AD. Estrogen increases the secretion and metabolism of amyloid precursor protein,
may help synapse formation, and is reported to protect neurons from toxins.
Restriction fragment length polymorphisms (RFLPs) of the ERalpha gene at intron 1
and exon 2 were associated with a low bone mineral density in postmenopausal
women and also with AD in a Japanese population. OBJECTIVE: To determine whether
ERalpha gene polymorphisms are associated with transcriptional activity and AD.
METHODS: A luciferase reporter assay analyzed enhancer activity of the ERalpha
gene at intron 1 and exon 2. This activity was evaluated according to the RFLPs.
The RFLPs of the ERalpha gene were determined in Japanese patients clinically
diagnosed as having AD, white patients diagnosed as having AD at autopsy, and
corresponding healthy control subjects. The RFLPs were also evaluated for the
contribution of the ERalpha gene RFLPs to AD. RESULTS: We found weak (about 2
fold) enhancer activity of the ERalpha gene, which differed among RFLPs. Although
there were racial differences in these polymorphisms, we could not confirm the
previously reported association between ERalpha gene polymorphisms and AD.
CONCLUSION: Regulatory element of the ERalpha gene was found in intron 1, but we
found no association between ERalpha gene polymorphisms and AD.
PMID- 10681084
TI - Very late-onset Friedreich ataxia despite large GAA triplet repeat expansions.
AB - BACKGROUND: Most patients with Friedreich ataxia (FRDA) have abnormal GAA triplet
repeat expansions in both X25 genes. The size of the GAA expansion in the shorter
of the 2 expanded alleles correlates significantly with parameters of clinical
severity and is inversely related to the age at onset. OBJECTIVES: To describe
the clinical and molecular genetic findings in a patient with very late-onset
FRDA and to review the literature. PATIENT AND METHODS: A 58-year-old white woman
with mild progressive gait disturbance of 15 years' duration whose examination
revealed mild incoordination was analyzed for mutations in the X25 gene. A
combination of long-range polymerase chain reaction and genomic Southern blot
analyses were used to identify GAA expansions in intron 1 of the X25 gene. To
uncover evidence of somatic variability in triplet repeat length, DNA isolated
from several tissue samples was similarly analyzed. Single-strand conformational
polymorphism analysis was used to screen for mutations spanning the entire coding
sequence of frataxin and all intron-exon junctions of the X25 gene. RESULTS: DNA
isolated from blood leukocytes revealed GAA triplet repeat expansions in both X25
genes, which were estimated to contain 835 and 1200 repeats. Similar expansions
were detected in DNA isolated from lymphoblasts, fibroblasts, buccal cells, and
sural nerve, with estimated mean (+/- SD) lengths of the shorter and longer
expansions being 854 (+/-69) and 1283 (+/-72) triplets, respectively. A review of
reported cases of late-onset Friedreich ataxia (25-39 years) and very late-onset
Friedreich ataxia (> or =40 years) demonstrated that this is the first instance
of a patient presenting with very late-onset FRDA despite carrying more than 800
GAA repeats in both expanded X25 alleles. CONCLUSIONS: This unique case of very
late-onset FRDA highlights a limitation in our ability to accurately predict the
phenotype in FRDA based solely on the size of the GAA expansion. Other genetic or
environmental factors may significantly modify disease severity in FRDA.
PMID- 10681085
TI - Mechanism in progressive lacunar infarction: a case report with magnetic
resonance imaging.
AB - BACKGROUND: The mechanism of a progressive lacunar infarction is not well
understood, and changes in ischemic tissue after onset have not yet been
clarified clinically. OBJECTIVE: To investigate the pathophysiological
characteristics of a case of progressive lacunar infarction using diffusion
weighted and conventional magnetic resonance imaging (MRI) scans. PATIENT: A 73
year-old woman was hospitalized 18 hours after stroke onset and was diagnosed as
having a lacunar infarction in the perforating territory of the left middle
cerebral artery. Despite treatment, the hemiparesis worsened, with the peak on
the fourth day after onset. Diffusion-weighted and conventional MRI scans
provided clues to the pathogenesis. FINDINGS AND CONCLUSIONS: In the acute stage,
gradual enlargement of the hyperintense lesion, reflecting fresh ischemic tissue,
and neurological deterioration were observed by serial examination of diffusion
weighted MRI scans. A conventional coronal MRI scan revealed a 2-layered ischemic
lesion, suggesting the involvement of perforating arteries. These findings
indicated that hemodynamic impairment of the microcirculation in the perforators
was the major cause of the lacunar infarction.
PMID- 10681086
TI - Cerebral venous thrombosis associated with epoetin alfa therapy.
AB - BACKGROUND: Cerebral venous thrombosis is a rare complication of polycythemia. To
our knowledge, epoetin alfa-induced polycythemia has not previously been reported
in association with cerebral venous thrombosis. CASE DESCRIPTION: A 37-year-old
patient who was receiving peritoneal dialysis and epoetin alfa (Epogen) therapy
presented with a several-day history of worsening headache, and a neuroimaging
scan demonstrated thrombosis of the sagittal and transverse sinus. Epoetin alfa
therapy, which had been initiated 3 months earlier according to an institutional
protocol, was associated with a problematic increase in hematocrit values.
CONCLUSIONS: Headache should raise the suspicion of cerebral venous thrombosis in
patients who are being treated with epoetin alfa, particularly in the presence of
elevated hematocrit values. Monitoring hematocrit parameters in accordance with
"standard guidelines" is recommended.
PMID- 10681087
TI - Tolcapone and hepatotoxic effects. Tasmar Advisory Panel.
AB - Four patients with Parkinson disease have recently been described in whom severe
hepatic dysfunction developed in association with tolcapone therapy. These
reports led to the introduction of a "black box" warning and more intensive
monitoring requirements in the United States. A review of these cases and all
clinical trials indicates that liver dysfunction did not develop in any patient
who had received monitoring of liver function according to the original
prescribing information. Virtually all instances of liver enzyme abnormality and
clinical liver dysfunction occurred within 6 months of initiating treatment. To
assess the current role of tolcapone therapy in Parkinson disease, a panel of
neurologists and hepatologists was convened. Consensus was reached with respect
to the following: (1) Tolcapone is an effective agent in the treatment of
patients with fluctuating Parkinson disease. (2) The risk of developing
irreversible liver injury is negligible with appropriate monitoring. (3) It may
be possible to reduce the frequency of monitoring after 6 months of treatment.
(4) The requirement that tolcapone be withdrawn if liver enzymes are elevated
above the upper limit of normal on a single occasion is unnecessarily
restrictive. It was concluded that tolcapone, when used as an adjunct to
levodopa, is an effective anti-parkinsonian agent and that less frequent
monitoring after 6 months, with an action limit of 2 to 3 times the upper limit
of normal, is sufficient to ensure safety in patients who are deriving benefit
from the drug.
PMID- 10681088
TI - Weak and numb feet in a man with knobby hands.
PMID- 10681089
TI - New drugs: which should be included in the formulary? Epilepsy: all new drugs
should be included.
PMID- 10681090
TI - Restrictions on the availability of antiepileptic drugs.
PMID- 10681091
TI - New antiepileptic drugs: should all be made available?
PMID- 10681092
TI - Wilson's disease.
PMID- 10681093
TI - Solvent toxicity and cognition impairment.
PMID- 10681094
TI - Effects of hormone replacement therapy on lipid peroxides and oxidation system in
postmenopausal women.
AB - A short-term evaluation of 6 months of estrogen therapy on oxidant status in 38
postmenopausal women was conducted. The levels of serum lipid peroxidation
products, glutathione (GSH) status, and glutathione-related enzymes were
evaluated before and after 6 months of hormone replacement therapy. After 6
months of estrogen treatment there was a significantly increased concentration of
thiobarbituric acid-reactive substances (TBARS), which are an end product of
lipid peroxidation. This was accompanied by a significant increase in the
activity of glutathione peroxidase (GSH-Px). However, the activities of
glutathione reductase (GSSG-R) and superoxide dismutase (SOD) were significantly
decreased and total protein thiols were reduced. Data suggest that hormone
replacement therapy in postmenopausal women is associated with oxidant
mechanisms.
PMID- 10681095
TI - Comparison of oxidative stress indicators in plasma of recent-onset and long-term
type 1 diabetic patients.
AB - Oxidative stress was compared in plasma of 15 recently diagnosed (<2 mo) or 15
longstanding (>5 yr) type 1 diabetic patients with 15 healthy volunteers. Lipid
peroxidation indices measured in plasma included thiobarbituric acid-reactive
substances (TBARS), conjugated dienes, and lipid hydroperoxide (ROOH). The values
obtained were corrected for phospholipid to minimize this as a confounding
factor. In recently diagnosed diabetics, plasma conjugated lipid dienes were
significantly elevated. However, in longstanding diabetics there was a marked
increase in TBARS, conjugated dienes, and lipid hydroperoxide levels. Our
findings showed increased oxidative stress in type 1 diabetics regardless of
metabolic control and that conjugated diene measurement appeared to be the most
sensitive bioindicator of oxidant stress in our population.
PMID- 10681096
TI - Are individuals with glutathione S-transferase GSTT1 null genotype more
susceptible to in vitro oxidative damage?
AB - Recent epidemiological studies proposed that glutathione S-transferase (GST) T1
null genotype was correlated with an increased susceptibility to diseases
associated with oxidative stress, including cancer. A comparative study using
erythrocytes from individuals with GSTT1 null genotype was carried out to
determine how resistance to oxidative stress is affected by lack of this gene,
and whether the GST status of a person is an important factor in risk toward
oxidant chemicals. Malondialdehyde and carbonyl levels and fluorescence and
chemiluminescence formation were used as biomarkers of oxidative stress in
erythrocytes exposed in vitro to cumene hydroperoxide (CumOOH), an oxidizing
agent. When peroxidation-dependent changes in these parameters were compared
between GSTT1 null genotype and controls, who are both GSTM1 and GSTT1 positive,
no significant differences were found between the two genotypes, although the
erythrocytes of the GSTT1 null group had lower GSTT1 activity toward CumOOH. Our
results indicate that erythrocytes from individuals with GSTT1 null genotype are
not abnormally susceptible to CumOOH-induced oxidant challenge.
PMID- 10681097
TI - Embryotoxic and teratogenic effects of indium chloride in rats and rabbits.
AB - Daily indium chloride doses of control (0), 50, 100, 200, or 400 mg/kg were
administered orally to Sprague-Dawley rats by gavage, on d 6-15 of gestation, and
daily metal doses of control (0), 50, 100, or 200 mg/kg were administered to New
Zealand rabbits on d 6-20 of gestation. Further groups of pregnant rats were
treated with control (0) or 400 mg/kg indium chloride orally on one of d 8, 9,
10, 11, 12, 13, 14, or 15 of gestation. The dams and fetuses were examined on d
21 (rats) and 30 (rabbits) of gestation, using standard teratological methods.
Indium concentration was determined in the maternal and fetal blood, as well as
in the amniotic fluid, by atomic absorption spectrometry. Indium was found to
cross the placenta and appeared in fetal blood in proportion to the metal
concentration of the maternal blood. In the amniotic fluid, indium concentrations
remained below the detection limit. In rats, indium chloride produced dose
dependent maternal toxic effects, with a dose of 400 mg/kg inducing
embryotoxicity (embryolethality) and teratogenicity. Doses of 200 and 100 mg/kg
were embryotoxic (retarding) and teratogenic, causing skeletal and visceral
anomalies in addition to external anomalies (rudimentary or missing tail,
syndactylia, clubfoot, exencephalia) in rats. In rabbits, 200 mg/kg indium
chloride was lethal for the dams and the embryos (some of the animals died, and
the number of abortions and full resorptions increased). This dose was found to
be teratogenic (caused gross renal anomalies) and increased the frequency of
fetuses with skeletal retardation. In rats, the effects of indium chloride
causing fetal retardation was found to be independent of exposure time. The
teratogenic effects were the highest on d 11 and 12 of gestation, when indium
chloride caused gross external malformations. Data suggest that the teratogenic
effects of indium chloride can be attributed primarily to a direct cytotoxic
action of indium resulting from placental transfer, but the effect is not a
selective one, as it appears only in the presence of maternal toxic effects.
PMID- 10681098
TI - Effect of cadmium on Pekin duck total body water, water flux, renal filtration,
and salt gland function.
AB - The following hypotheses were examined using Pekin ducks (Anas platyrhynchos) as
a model for marine ducks: cadmium (Cd) intake affects (1) salt gland and/or
kidney function of ducks and (2) osmoregulation differently in male and female
ducks. Birds were fed 0, 50, or 300 microg Cd/g food. They were gradually
acclimated to 450 mM NaCl and then drank 300 mM NaCl for 3 mo while salt gland
secretion (SGS), glomerular filtration rate (GFR), total body water (TBW), and
water flux (WF) were measured in ducks eating control and high-Cd diets. Cadmium
ingestion did not markedly affect body mass, but significantly enlarged the salt
glands and kidneys. Enhancement of kidney mass was greater in males. Cadmium
ingestion did not affect TBW or WF, but tended to increase interstitial fluid
space at the expense of intracellular fluid. Sex did not affect TBW, but males
had greater WF. Birds that ate Cd diets, especially the higher Cd diet, exhibited
renal tubular damage and lower GFR. Ducks that ate Cd had lower plasma sodium
concentration and osmolality and, to activate SGS, required longer infusion of
NaCl and larger increments
PMID- 10681099
TI - Comparison of oxime-initiated reactivation of organophosphorous-inhibited
acetylcholinesterase in brains of avian embryos.
AB - Organophosphorous (OP) insecticide-induced inhibition and oxime reactivation of
acetylcholinesterase (AChE) was determined in whole-brain homogenates prepared
from 15-d-old chick embryos. Doses of chlorpyrifos, parathion, acephate, and
trichlorfon that inhibited AChE >70% were administered to the embryos. Following
insecticide exposure, an in vitro system compared the capability of the oximes
pralidoxime (2-PAM), obidoxime, TMB-4, and HI-6 to reactivate the OP-inhibited
AChE. Concentration-related increases in AChE activities were noted in embryo
brains reactivated with 2-PAM, TMB, and HI-6. 2-PAM was the most effective
reactivator of trichlorfon-inhibited AChE; 2-PAM and obidoxime were relatively
similar in effectiveness for reactivation of AChE inhibited with the other OP
insecticides used as test agents. All oximes were similarly effective against
acephate, but HI-6 was the least effective reactivator of AChE in chick embryo
brain homogenates inhibited by the other OP insecticides. These results suggest
that both the OP insecticide inhibiting AChE and the oxime reactivating this
enzyme can contribute to the effectiveness of the avian brain AChE reactivation.
PMID- 10681100
TI - Effectiveness of comprehensive services for crack-dependent mothers with newborns
and young children.
AB - This article presents an outcome study of the Family Rehabilitation Program
(FRP), a unique network of community-based programs in New York City that
provides comprehensive services to families with drug-dependent parents, most
caring for prenatally cocaine-exposed newborns. An admission sample of 173
mothers in 17 FRP sites was studied for one year; substance use was assessed by
hair analysis and self-report. Mean length of retention was 10 months; half the
clients were still active in the program at follow-up. Mothers completing or
still active in FRP had higher rates of abstinence and substantially lower
average levels of cocaine in their hair at follow-up than those exiting
prematurely. The percent of families with children out of their homes did not
increase significantly between admission and follow-up, and completing or
remaining active in the program were associated with less out-of-home placement
at follow-up.
PMID- 10681101
TI - Residential treatment for women with dependent children: one agency's approach.
AB - The Salvation Army First Choice Program, located in Fort Worth, Texas, provides
comprehensive-as well as gender-specific-treatment for addicted women while
providing child care and therapeutic services for children. Specific program
attributes (including therapeutic interventions, community linkages, and staffing
patterns) are described, and the five-year evaluation initiative, designed to
examine relationships between client characteristics, program participation, and
client progress is outlined. Findings from initial analyses examining correlates
of 90-day dropout suggest a complex interaction among specific problems a woman
brings to treatment, her level of dysfunction at treatment entry, how much social
support is available to her, and what services she receives.
PMID- 10681102
TI - Criminality among female drug abusers.
AB - Criminality among female (n=351) drug abusers is compared to that of men (n=798)
as part of a longitudinal study of persons in treatment in Sweden (the SWEDATE
project). The extent of criminality was much less among females than among males,
and fewer women than men were criminal. The pattern of criminality varied between
the sexes. Women's crime debuts occurred later, and they committed less violent
crimes and more drug-related crimes. The majority of women supported themselves
in other ways than with criminality. Also, women tended to have a more severe
pattern of abuse, a more rapid drug career, and more complex psychological
problems than men. A subgroup of prostitutes whose drug of choice was heroin
often began drug use early with cannabis and went on to amphetamine for their
first injection, which often took place in a junkie pad. There was also a
criminal group (as there was among men) with a very early and intensive juvenile
delinquency pattern, early drug debuts and a rapid transition to regular abuse
and extensive adult criminality. Forty-two percent of the women had no criminal
records; they had more extensive multiple drug abuse than the other women (this
was also true for the noncriminal male addicts). The study shows that drug abuse
and criminality are interrelated for certain individuals, but not for others.
PMID- 10681103
TI - Drug treatment outcomes: investigating the long-term effects of sexual and
physical abuse histories.
AB - Individuals in drug treatment, particularly women, generally report high levels
of past sexual and physical abuse. Although histories of sexual and physical
abuse are associated with greater prevalence and severity of depression, anxiety,
phobias, and interpersonal difficulties for individuals seeking substance-related
treatment, several recent studies failed to show that prior sexual or physical
abuse compromised short-term drug treatment outcomes. This study examined the
possible effects of sexual and physical abuse on a wide array of behavioral
domains over a two-year posttreatment period. The findings indicate few
differences between those with and without past histories of such abuse in terms
of drug use, drug treatment and 12-Step program participation, criminality,
income sources, intimate relationships, family functioning, and psychiatric
symptoms. There are specific exceptions, but they apply only to men. Overall, the
findings indicate that the impact of sexual and physical abuse histories on
relatively long-term treatment outcomes is minimal. Addressing the sexual and
physical abuse histories of those seeking treatment for drug abuse may be
justified on humanistic grounds, but it will not significantly improve the long
term effectiveness of drug treatment, nor will it substantially enhance the lives
of those with histories of abuse.
PMID- 10681104
TI - Using naltrexone in inpatient alcoholism treatment.
AB - Naltrexone has been used successfully in outpatient settings as an adjunct to
alcoholism treatment. This study examines the efficacy of using naltrexone in an
inpatient treatment setting. Sixty-three alcohol-dependent patients who
volunteered for a double-blind, placebo-controlled study were followed over the
course of their 20 days in treatment and six months follow-up. A comparison group
of 59 patients who did not volunteer were also studied over the same period of
time. Patients in the study group were randomly assigned to receive naltrexone or
placebo. Information was gathered daily on alcohol craving, drug craving and
moods on self-reporting forms from the naltrexone and placebo groups, and from
the comparison group. Follow-up data was gathered through self-report and through
Washington State's TARGET management information system. No significant
differences were found in craving scores while in treatment, nor in recidivism
after treatment.
PMID- 10681105
TI - Regional cerebral blood flow in alcohol-induced violence: a case study.
AB - A case is presented of a 20-year-old man who became violent on many occasions
after ingesting alcohol. On one occasion he committed an armed robbery. Two brain
SPECT studies were performed: one when he was alcohol free, and one after he
ingested alcohol in the same pattern as the night of the crime. The "alcohol
free" study revealed marked hyperactivity in the cingulate gyrus, right and left
lateral frontal lobes, right and left lateral parietal lobes and the right
lateral temporal lobe. The "alcohol intoxication" study showed an overall
dampening effect on the hyperactive areas of the brain, with only the anterior
cingulate gyrus showing excessive activity. In addition, the right and left
prefrontal cortex became hypoperfused, decreasing impulse control and judgment,
as did the left and right temporal lobes, increasing the likelihood for
aggression. This study suggests that this man may have been "self-medicating" an
overactive brain, but in the process induced a state that increased the
likelihood for aggressive behavior. This case study suggests the need for further
research in the area of alcohol-induced violence and the potential usefulness of
SPECT imaging, although no conclusions can be drawn from one case.
PMID- 10681106
TI - A preliminary study of drug abuse and its mental health and health consequences
among addicts in Greater Accra, Ghana.
AB - This article represents a preliminary effort to describe drug abuse in Tudu, one
of a number of neighborhoods in Accra that serve as drug centers. The problems of
such neighborhoods reflect the drug problems that currently beset the rest of
Ghana and Accra in particular. There is almost no fundamental current research on
this issue. The few works cited comprise virtually the entire body of existing
literature on this subject, and they fall far short of providing a comprehensive
account of the changes that drugs have made in the social structure of the
greater Accra region. This article is based on research done in the drug parlors
and alleyways where the Tudu drug trade is conducted, and is a preliminary effort
to redress the current lack of information by documenting the changing patterns
of drug use in greater Accra. The findings reveal that a shift is underway from
traditional marijuana abuse to abuse of crack cocaine and heroin. The article
highlights the social relations that characterize this more dangerous drug
setting and enhances the understanding of the psychiatric comorbidity of drug
abuse, health, and behavior. These conclusions are derived from a multifaceted
approach to data collection, taken to enhance the validity of research findings.
PMID- 10681107
TI - Effects of control and motivation on treatment outcome.
AB - This investigation was designed to determine who would benefit most from enhanced
motivation, increased awareness of control, and the opportunity to make choices
in substance abuse treatment. Thirty males and 21 females participated in
treatment planning, goal setting, and determining methadone dosage level.
Subjects were assigned at random to the Choice or Force condition. Choice group
subjects were allowed to choose the type of treatment and their urinalysis
schedule. No significant differences between groups on treatment outcome
variables were found. However, higher motivation at the start of treatment
predicted greater depression after 12 weeks. Results suggest that more highly
motivated individuals seeking relief from substance dependency may be more
vulnerable to depression which, in turn, can attenuate treatment effectiveness.
PMID- 10681108
TI - A survey of adult recreational drug use via the World Wide Web: the DRUGNET
study.
AB - DRUGNET was a cross-sectional survey of adult recreational drug users (i.e., not
abusers) via the World Wide Web of the Internet. The purpose of this survey was
to provide a unique, broad description of nondeviant adult recreational drug
users. The survey instrument had four divisions: demographic and lifestyle
indices, drug use history, legal history and attitudes about drug issues, and the
General Well-being Schedule (GWBS). Responses were received from 1,473 self
identified drug users. Of these, 567 completed only the first section, leaving
906 respondents who completed the entire survey. The typical respondent was a
White male who was well educated, employed full-time, a participant in
recreational and community activities, and who described his physical health
status as good. Their mental health, as measured by the GWBS, was similar to the
general adult U.S. population. Their drug-taking behavior appeared to be well
controlled, at mild to moderate levels in both frequency of use and degree of
intoxication. These findings have major implications for drug policy and indicate
the need for further research on the majority of drug users, who may be expected
to resemble this sample more than they do clinical populations of drug abusers.
PMID- 10681109
TI - The social construction of the crack epidemic in the print media.
AB - Early news coverage of the rapid expansions and horrors associated with use of
crack in the mid-1980s led to a great panic. Scholarly research subsequently
debunked the various myths emanating from this media scare. This article examines
whether this expanded understanding was reflected in the quality of news coverage
over time through a comprehensive examination of all articles about crack cocaine
appearing in the New York Times, Time, and Newsweek from 1985 through 1995. It
was found that later news stories were generally less blatant, but overall did
not correct for previous exaggerations. The long-term perspective also revealed
an insidious bias in news coverage through its focus on the inner city, in spite
of broader use of crack. This misleading view of "the problem" constructed by the
media probably helped divert attention from persistent structural problems facing
the inner-city. Scholars and activists need to continue their efforts to focus
attention on the underlying social problems to counteract the media's propensity
to focus on what might more appropriately be termed symptoms, such as the "crack
epidemic."
PMID- 10681110
TI - Teotlaqualli: the psychoactive food of the Aztec gods.
AB - The Aztecs in pre-Columbian Mexico used not only a large number of single
hallucinogens, they also used some combinations. The present article describes
reports of the use of teotlaqualli, an unction prepared from ololiuhqui and
picietl, with a large number of additions. The work of the chroniclers of pre
Columbian Mexico served as a source of information. The teotlaqualli was offered
to the gods, for whom it served as food. The Aztec priests smeared themselves
with this unction, to lose fear and to get the appropriate state of mind to serve
the Aztec gods. A few cases are reported in which the Aztec emperor or soldiers
were smeared with teotlaqualli. It is suggested that the black color of some
Aztec deities, as depicted in the codices, was due to anointment with
teotlaqualli. In addition to its use for psychoactive purposes, teotlaqualli was
used in medicine under the name teopatli.
PMID- 10681111
TI - The status of psychologists' training about and treatment of substance-abusing
clients.
AB - A random survey of 1,200 psychologists (with a 62% response rate) indicated that
most psychologists (91%) are to some degree involved in clinical practice with
substance abusers, although most have no formal education (74%) or training (54%)
in substance abuse. Relevant recommendations are made.
PMID- 10681112
TI - Subjective appraisal of problem severity and the ASI: secondary data or second
opinion? Addiction Severity Index.
AB - The Addiction Severity Index is a popular research and clinical tool for the
characterization of individuals grappling with substance abuse problems. For
research, use of the seven objectively calculated composite scores of problem
severity is recommended. In contrast, clinical use of the instrument relies more
upon its subjectively derived interviewer and client severity rating scores.
However, little systematic research has looked at the comparability of these two
sources of client data. This study compared the objective and subjective scores
of the ASI of male (n=141) and female (n=58) clients entering substance abuse
treatment. In addition, clients' narratives about their most worrisome problems
were recorded and put to content analyses. While significant correlations were
found among the various subjective indices, little relationship could be
discerned between the objective composite scores and any of the subjective
indices derived from either the ASI or the clients' narratives. As the focus of
outcome research shifts from objective client and treatment characteristics to a
better understanding of the process of intervention, empirical characterization
of substance abuse treatment outcome may be enriched by the inclusion of
subjective data that taps into the client's own perceptions of problems and
treatment efficacy in addition to more objective sources of data.
PMID- 10681113
TI - Therapeutic use of cannabis by crack addicts in Brazil.
AB - This study ensued from clinical observations based on spontaneous accounts by
crack abusers undergoing their first psychiatric assessment, where they reported
using cannabis in an attempt to ease their own withdrawal symptoms. Throughout a
period of nine months, the researchers followed up on 25 male patients aged 16 to
28 who were strongly addicted to crack, as diagnosed through the Composite
International Diagnostic Interview (CIDI), according to CID-10 and DSM-IV
diagnostic criteria. Most of the subjects (68%, or 17 individuals) ceased to use
crack and reported that the use of cannabis had reduced their craving symptoms,
and produced subjective and concrete changes in their behavior, helping them to
overcome crack addiction. The authors discuss some psychological, pharmacological
and cultural aspects of these findings.
PMID- 10681114
TI - Presentation of words to separate hemispheres prevents interword illusory
conjunctions.
AB - We tested the hypothesis that division of inputs between the hemispheres could
prevent interword letter migrations in the form of illusory conjunctions. The
task was to decide whether a centrally-presented consonant-vowel-consonant (CVC)
target word matched one of four CVC words presented to a single hemisphere or
divided between the hemispheres in a subsequent test display. During half of the
target-absent trials, known as conjunction trials, letters from two separate
words (e.g., "tag" and "cop") in the test display could be mistaken for a target
word (e.g., "top"). For the other half of the target-absent trails, the test
display did not match any target consonants (Experiment 1, N = 16) or it matched
one target consonant (Experiment 2, N = 29), the latter constituting true
"feature" trials. Bi- as compared to unihemispheric presentation significantly
reduced the number of conjunction, but not feature, errors. Illusory conjunctions
did not occur when the words were presented to separate hemispheres.
PMID- 10681115
TI - Broad band spectral EEG parameters correlated with different IQ measurements.
AB - The relationship of IQ (measured by WAIS and all its subscales) and EEG broad
band spectral parameters were studied in 40 right-handed, male volunteers ranging
in age from 20 to 25 years old. EEGs were recorded in 20 derivations during rest
with eyes opened. The results obtained reveal positive and negative correlations
with abundant frontal participation in all bands. Mean frequency data show a
frequency shift in a very narrow range suggesting that more relations in narrow
band could be achieved. These results highlight the need of psychological tests
that measure more homogeneous abilities and finer measurement technique to reveal
clearly explainable correlations and demonstrate that EEG recordings do reflect
intellectual abilities.
PMID- 10681116
TI - Spatial aspects of letter cancellation performance in Arabic readers.
AB - Studies of visuospatial and directed attention that used subjects drawn from
cultures with left-to-right reading patterns have suggested a slight performance
bias toward left space. This pattern could reflect an intrinsic, organic, bias in
spatial processing or the confounding effect of overlearned reading patterns. We
studied the spatial distribution of errors on random array letter cancellation
tasks obtained from 128 healthy Syrians who were native readers of Arabic. Fifty
eight of the 128 subjects (45.3%) made a total of 91 errors in which they omitted
cancelling a target. The distribution of errors was not spatially biased. This
differs from the error pattern reported for native readers of English on a
similar task. The findings, consistent with results of other approaches, suggest
that reading patterns influence visuospatial attention, but are not the sole
cause of spatial biases observed in readers of Indo-European languages.
PMID- 10681117
TI - Patterns of waking EEG spectral power in chemically intolerant individuals during
repeated chemical exposures.
AB - Previous studies indicate that low level chemical intolerance (CI) is a symptom
of several different controversial conditions with neuropsychiatric features,
e.g., chronic fatigue syndrome, fibromyalgia, multiple chemical sensitivity, and
"Persian Gulf Syndrome". Prior studies suggest that limbic and/or mesolimbic
sensitization may contribute to development of CI. The purpose of this report was
to document the waking electroencephalographic (EEG) patterns of individuals with
CI during chemical exposures presented over repeated sessions. Three groups of
adult subjects who were recruited from the community participated in the study:
self-reported CI who had made associated lifestyle changes due to their
intolerance (CI/ LSC), self-reported CI who had not made such changes (CI), and
normal controls without self-reported CI. Subjects underwent two sessions
involving one-minute EEG recordings during exposures to low level chemical odors
(a probe for limbic activation). The CI, but not the CI/ LSC, subjects had
increased absolute delta power after the chemical exposures during the second,
but not the first, session. The findings support the neural sensitization
hypothesis for intolerance to low levels of environmental chemicals in vulnerable
individuals. As in human studies of stimulant drug sensitization, those with the
strongest past history with sensitizing agents may not show-term sensitization to
low level exposures in the laboratory.
PMID- 10681118
TI - Expanding the neurological examination using functional neurologic assessment
part I: methodological considerations.
AB - Manual assessment of muscular function, in particular a method known as applied
kinesiology (AK), is a clinical measure of neurologic function. A review of the
literature reveals methodological problems with previous studies of AK as a form
of neurologic assessment. Research designs that do not reflect clinical practice
and principles of AK are common in the literature. Additional study is warranted
to explore the potential of AK manual muscle testing as a diagnostic tool. We
outline principles of AK and recommend that future research reflect more
accurately the clinical practice of functional neurologic assessment and applied
kinesiology.
PMID- 10681119
TI - Expanding the neurological examination using functional neurologic assessment:
part II neurologic basis of applied kinesiology.
AB - Functional Neurologic Assessment and treatment methods common to the practice of
applied kinesiology are presented. These methods are proposed to enhance
neurological examination and treatment procedures toward more effective
assessment and care of functional impairment. A neurologic model for these
procedures is proposed. Manual assessment of muscular function is used to
identify changes associated with facilitation and inhibition, in response to the
introduction of sensory receptor-based stimuli. Muscle testing responses to
sensory stimulation of known value are compared with usually predictable patterns
based on known neuroanatomy and neurophysiology, guiding the clinician to an
understanding of the functional status of the patient's nervous system. These
assessment procedures are used in addition to other standard diagnostic measures
to augment rather than replace the existing diagnostic armamentarium. The proper
understanding of the neurophysiologic basis of muscle testing procedures will
assist in the design of further investigations into applied kinesiology.
Accordingly, the neurophysiologic basis and proposed mechanisms of these methods
are reviewed.
PMID- 10681120
TI - Visual evoked potentials and heart rate during white noise stimulation.
AB - Visual evoked potentials (VEPs) were recorded in 12 adult participants as a
function of the temporal frequency of a phase-reversed checkerboard, with or
without a simultaneously presented white noise. During the VEP recordings also
the pulse rate was measured. VEP amplitude changed as function of temporal
frequency, but it was not affected by noise. Pulse rate was stable during the
session without noise, but it increased during the white noise stimulation at
high temporal frequencies. Heart acceleration might be associated to conditions
when processing at low levels of visual sensitivity (high temporal frequencies)
is furthermore disturbed by interfering stimulation (noise).
PMID- 10681121
TI - Orchidectomy affects the innervation of the rat thymus.
AB - To assess a putative role of the neural pathways in transfer of information from
the gonads to the thymus, adult AO rats were orchidectomized (ORX) or sham ORX
(controls); sacrificed 1, 3, 7, or 15 days later and their thymi were analyzed
for: (a) the concentrations of noradrenaline (NA), dopamine (DA) and serotonin (5
HT) and distribution of monoamine-containing nerve profiles and (b) the
acetylcholinesterase (AChE) activity and distribution of AChE-containing nerve
profiles. Three days after the castration, an elevation in the level of both
catecholamines, reflecting an increase in the overall intensity of nerve fibers
autofluorescence, was found. Seven days post castration neither NA nor DA
concentration differed from the appropriate control values, while 15 days after
the surgery the concentration of NA was lower than that in the controls, most
likely, due to diminished density of noradrenergic nerve profiles. In both the
rats sacrificed 7 and 15 days after orchidectomy the concentration of 5-HT was
reduced as result of a decrease in the density of 5-HT-containing autofluorescent
cells. The activity of AChE was depressed one day after the surgery; then
increased, so that 3 days post castration its value was higher than that in the
sham ORX. After this increase, AChE activity decreased being, at postoperative
day 7 and 15, lower than that in the controls. It seems that this decrease in
AChE activity reflected, not only a reduction in the density of AChE-containing
nerve fibers, but also a decrease in the density of AChE positive cells. Thus,
the results indicate that orchidectomy can evoke changes in the T-cell maturation
altering modulatory influences on this process coming via neural route, as well
as those coming from the mast cells and AChE positive epithelial cells which
constitute important component of the thymus microenvironment.
PMID- 10681122
TI - Serotonergic neuronal sprouting as a potential mechanism of recovery in multiple
sclerosis.
AB - Experimental allergic encephalomyelitis (EAE) is widely considered as an animal
model of multiple sclerosis (MS). Damage to the bulbospinal serotonergic (5-HT)
neurons occurs in the early paralytic stages of EAE in rats with the severity of
neurologic signs corresponding to spinal serotonergic depletion. Neurologic
recovery of EAE rats is associated with reestablishment of spinal 5-HT
transmission possibly through sprouting of undamaged axons and nerve terminals.
Damage to the bulbospinal serotonergic fibers also occurs in patients with MS (as
reflected by reduced lumbar CSF 5-HIAA levels) and may contribute to several
manifestations of the disease including autonomic dysregulation, sensory symptoms
(i.e., paresthesias, pain) and motor symptoms (weakness, spasticity, clonus).
Spinal serotonergic neuronal sprouting with regeneration of 5-HT nerve terminals
may also occur in the early stages of MS and may be associated with spontaneous
remission of MS symptoms following an acute relapse. Sprouting of serotonergic
neurons may also explain the disparity in MS between the extent of demyelinating
plaques and clinical signs of the disease. The chronic course of MS may be
associated with progressive axonal degenerative changes with reduction of
serotonergic nerve terminals and loss of their sprouting capability. It is
proposed that the beneficial effects of treatment with AC pulsed electromagnetic
fields on the symptoms and course of the disease in patients with chronic
progressive MS may be related in part to renewed sprouting of serotonergic
neurons.
PMID- 10681123
TI - Yawning and stretching induced by transcranial application of AC pulsed
electromagnetic fields in Parkinson's disease.
AB - Yawning is considered a brainstem regulated behavior which is associated with
changes in arousal and activity levels. Yawning and stretching are dopamine (DA)
mediated behaviors and pharmacological studies indicate that these behaviors are
associated with increased DA release coupled with stimulation of postsynaptic DA
D2 receptors. Despite their relation to the dopaminergic system, yawning and
stretching are poorly documented in untreated or treated patients with
Parkinson's disease (PD). A 49 year old fully medicated female patient with
juvenile onset PD is presented in whom recurrent episodes of yawning and
stretching developed during transcranial administration of AC pulsed
electromagnetic fields (EM Fs) of picotesla flux density. These episodes have not
been observed previously in this or other patients during treatment with levodopa
or DA receptor agonists or in unmedicated PD patients during treatment with AC
pulsed EMFs. It is suggested that yawning and stretching behavior resulted in
this patient from a synergistic interaction between EMFs and DA derived from
levodopa supplementation with EMFs possibly facilitating the release of DA and
simultaneously activating postsynaptic DA-D2 receptors in the nigrostriatal
dopaminergic pathways. In addition, it is postulated that the release of ACTH/MSH
peptides from peptidergic neurons in the brain upon stimulation of the DA-D2
receptors reinforced the yawning and stretching behavior.
PMID- 10681124
TI - It's not all in our genes!
PMID- 10681125
TI - Paper Alert. Cell Biology.
PMID- 10681126
TI - Web alert. Cell differentiation cell multiplication.
PMID- 10681127
TI - Cell multiplication. Peering in and peering out: regulation of and by the cell
cycle.
PMID- 10681128
TI - Anaesthetic Research Society. Plymouth, July 8-9, 1999. Abstracts.
PMID- 10681129
TI - [The appearance of the ophthalmoscope and the biomicroscope].
PMID- 10681130
TI - Results of mental health needs assessments performed by four urban American
Indian organizations.
PMID- 10681131
TI - 5-Hydroxy-4-oxo-L-norvaline depletes intracellular glutathione: a new modulator
of drug resistance.
AB - To search for compounds that reverse the drug resistance induced by glutathione
(GSH), an original screening system to detect intracellular GSH depleters was
established. Among 8843 microbes derived from the soil samples tested, the
extracts of two Streptomyces species named KS6701 and KS8846, lowered the
intracellular GSH level of Saccharomyces cerevisiae 5 x 47. From both the
microbes, 5-hydroxy-4-oxo-L-norvaline (HON) was isolated as the active compound.
At a concentration of 50-100 micrograms/ml, HON also decreased the GSH/protein
level of the human ovarian tumor cell line, 2008/C13*5.25 and reversed its
resistance to cisplatin. We also investigated the mechanism of the depletion. HON
had little effect on gamma-glutamylcysteine synthetase (gamma-GCS) or glutathione
synthetase, but HON decreased the quantity of thiol substances when it was
spontaneously reacted with them. This suggested that the GSH depletion by HON
occurred through a mechanism different from that of buthionine sulfoximine, a
selective gamma-GCS inhibitor.
PMID- 10681132
TI - Certification examination of the College of Family Physicians of Canada. Part 4:
Simulated office orals.
PMID- 10681133
TI - Acute otitis media. Evidence base on managing acute otitis media had
inaccuracies.
PMID- 10681134
TI - Acute otitis media. Surgery has a limited but important role in managing acute
otitis media.
PMID- 10681135
TI - Surgical treatments should have been discussed.
PMID- 10681136
TI - Social and productive activities in elderly people. Activity (occupation) is
important for survival.
PMID- 10681137
TI - Social and productive activities in elderly people. Self rated health is
important predictor of mortality.
PMID- 10681138
TI - Randomised controlled trials in psychiatry. Scarcity of evidence is not
necessarily evidence against long term psychodynamic psychotherapy.
PMID- 10681139
TI - Evaluation of questionnaire on cancer family history on general practice. General
practitioners reassure those at low risk and refer those at high risk.
PMID- 10681141
TI - Significance of relationships.
PMID- 10681140
TI - Bacteria associated with butterfly stain of Chilean tepa.
AB - Butterfly stain, common in Chilean tepa (Laureliopsis philippiana [Looser]
Schodde) trees, appears in cross-section of the stem as a series of partially
overlapping orange-brown arcs that in early stages resembles a butterfly.
Bacterial isolates from stained tepa wood samples cultured under aerobic and
anaerobic conditions were identified using several commercially available
identification systems. Pseudomonas sp. were most common in the cultures handled
aerobically, and Clostridium sp. were found in the cultures handled
anaerobically. A pectynolitic Bacillus sp. and a Gram-negative rod-shaped
bacterium that emitted a strong naphthalene-like odor similar to that of stained
wood were also isolated. Not all isolates could be identified. This the first
report of Clostridium from tepa.
PMID- 10681142
TI - Clinical expertise and the DPT: a need for residency training.
PMID- 10681143
TI - Making jargon from kinetic and kinematic chains.
PMID- 10681144
TI - Treatment of shoulder impingement syndrome.
PMID- 10681145
TI - Studies of reliability: show me the question.
PMID- 10681147
TI - Secrets of diagnosis.
PMID- 10681146
TI - Grappling with the "miracle" of glucosamine.
PMID- 10681148
TI - EIIaCre -- utility of a general deleter strain.
PMID- 10681150
TI - Exposure-response relations of alpha-amylase sensitisation in British bakeries
and flour mills.
PMID- 10681152
TI - Gastrointestinal Endoscopy 2000. Conference proceedings. New York City, New York,
USA. March 27-28, 1999.
PMID- 10681151
TI - [The resistance of soil microorganisms to soil pollution by heavy metals].
AB - Microbial communities of grey podzolized soil of Left-Bank Ukraine are
characterized by high potential resistance to pollution with heavy metals: above
40% of organotrophic microorganisms are capable to resist to pollution with a
mixture of heavy metals (Cu2+, Cd2+, Pb2+, Zn2+) in a dose of 20 MPC of each
metal. Relative amount of resistant microorganisms in polluted soil increases up
to 93%. White zeolites and biohumus are promising for reclamation of soils
polluted with heavy metals. They decrease toxic effect of heavy metals on soil
microflora and promote development of microflora resistant to pollution.
PMID- 10681153
TI - Brain in the twentieth century.
PMID- 10681154
TI - Proceedings of the International Symposium on Vaccinology. Paris, France, 18-20
November 1998.
PMID- 10681155
TI - [Report by the German Society of Gerontology and Geriatrics e. V. Protocol of the
meeting of the ZEAG. (Central European Society of Gerontologic/Geriatric
Societies) on 22 March 1999, 1 p.m., at the new Bad Hofgastein Congress Center].
PMID- 10681156
TI - [A trial of clonazepam treatment for manic-depressive psychoses].
AB - Clonazepam, which is a benzodiazepine structurally related to chlordiazepoxide
hydrochloride, diazepam and nitrazepam, has been available for the treatment of
seizure disorders in the USA since 1976 and in Japan since 1981. Recently,
clonazepam has attracted interest as drug for the treatment of manic-depressive
psychosis. Chouinard et al (1983), Victor et al (1984), Freinhar and Alvarez
(1985) and Santos and Morton (1987) have reported on the antimanic properties of
clonazepam, and Jones and Chouinard (1985), Zetine and Freedman (1986), Mas et al
(1993) and Kishimoto et al(1987) have reported on the antidepressive properties
of clonazepam. We have observed the antimanic and antidepressive properties of
clonazepam as well. Clonazepam is a useful therapeutic adjunct and the onset of
its effect is rapid. We cannot, however, advocate the use of only the therapeutic
agent for amelioration of manic-depressive psychosis. Clonazepam is a useful
supplement and has a diverse optimum daily dose for acute manic and depressive
states. Clonazepam should, at the time, be considered only as an alternative
treatment for patients nonresponsive to conventional therapy, and should be used
at a dosage of 3-6 mg/day for depressive state and 10 mg/day for acute manic
state in combination with other psychotropic drugs.
PMID- 10681157
TI - Appearance of highly sensitive cells to L-type Ca antagonist in cultured
cerebellar granule cells.
AB - We studied intracellular Ca2+ ([Ca2+]i) kinetics within single cells using and
image-analyzing system. We prepared a culture dish with a bottom made of quartz
(non-fluorescent glass) for reducing the background fluorescence during [Ca2+]i
measurement. Furthermore, we changed the concentration of the poly-L-lysine
solution which had been used to make cells adhere to the dish bottom from the
conventional 5 micrograms/ml to 15 micrograms/ml. This modification improved cell
viability, prevented colony formation, and therefore, provided favorable cell
samples for detection within single cells. Then, we investigated 25 mM KCl-evoked
changes in the [Ca2+]i level of rat cerebellar granule cells. We found that
sensitivity to KCl was high in some cells but low in others. In a study using the
highly sensitive cells, nicardipine, nimodipine and nifedipine were active even
at nanomolar or picomolar levels, although their affinities to the L-type Ca ion
channel have been reported to act only at micromolar levels.
PMID- 10681158
TI - [The influence of L-triiodothyronine on the action of desipramine on beta and
serotonin 2A receptor, monoamines in the rat brain].
AB - The co-administration of thyroid hormone and antidepressants is often useful in
the treatment of refractory depression. The aim of this study is to clarify the
anti-depressive mechanisms of repeated co- administration of thyroid hormone (T3)
and desipramine (DMI) in the rat brain. Forced swimming test, open-field test,
monoamine contents, beta receptor, and serotonin (5HT)2A receptor were compared
in four experimental groups (control, T3, DMI, DMI+T3). In the forced swimming
test, the (DMI+T3) group showed a significantly decreased immobility time
compared with that of the control group. The noradrenaline (NA) content in the
prefrontal cortex was highest in the (DMI+T3) group. Although beta receptor was
not altered in any brain region in the (DMI+T3) group, 5HT2A receptor was
significantly decreased, and the dopamine (DA) turnover rate was significantly
increased in the prefrontal cortex. This study suggests that the addition of T3
enhanced the action of DMI alone on the monoaminergic system in the prefrontal
cortex.
PMID- 10681159
TI - [The vertebrate nervous system comprises an enormous number of cell types].
AB - Neurogenesis is regulated by basic-helix-loop-helix (bHLH) transcription factors
in both vertebrates and insects. MASH1 and neurogenin, members of the bHLH genes,
are expressed in subsets of neural precursors and control their differentiation.
Downstream of the bHLH genes, PHD1, Phox2, and DRG11, which belong to PHD family
genes, are expressed in specific lineages of neurons and are involved in their
neuronal identity. Differentiated sensory and motor neurons express PEA3 and
ER81, members, of the ETS family, which specify neuronal connectivity. During
neuronal differentiation, these three families of transcription factors control
developmentally distinct operations. Increasing the numbers of members of the
families may underlie the generation of neuronal diversity.
PMID- 10681160
TI - [Brain cytokine network and novel characteristics of microglia].
AB - Microglia, macrophage-like cells in the central nervous system (CNS), are multi
functional cells; they play an important role in the removal of dead cells or
their remnants by phagocytosis in CNS degeneration and are one of the important
cells in the CNS cytokine network to produce and respond to a variety of
cytokines. Although little is known about microglia in the normal CNS, it is
obvious that they are quickly activated in all acute pathological events
including apoptosis, neurodegeneration and inflammation. Activation of microglia
in apoptosis is a double-edged response; under severe apoptotic conditions,
microglia act as scavengers removing tissue debris and inducing apoptosis in
damaged cells, whereas in more subtle injury they exert a surveillance function
and might play a protective role. The transformation of resting microglia into
full-blown phagocytes is strictly regulated. To understand the molecular basis of
controlling mechanisms of microglia in apoptosis, the study requires in vivo
models. For such purpose, we developed the brain-targeting gene delivery system
using immortalized microglia, which can facilitate investigation into the roles
of particular microglial genes in apoptosis and the gene therapy of several brain
disorders.
PMID- 10681161
TI - [Synapse-specificity and gene regulation during long-term potentiation].
PMID- 10681162
TI - Proceedings of the Cuban Biotechnology Conference, Havana, 1998.
PMID- 10681163
TI - Commentary on future allergy practice article.
PMID- 10681164
TI - Prayer in psychotherapy.
PMID- 10681165
TI - Report from the United States of America.
PMID- 10681166
TI - The eyes have it.
PMID- 10681167
TI - 3rd Annual North American Program on Computer Assisted Orthopaedic Surgery
(CAOS/USA '99). Pittsburgh, Pennsylvania, USA. June 7-19, 1999. Abstracts.
PMID- 10681169
TI - Future Trends in the Management of Rheumatoid Arthritis. Proceedings of the
International Rheumatology Round Tables, March 27-28, 1998 and February 19-20,
1999.
PMID- 10681168
TI - Proceedings of the symposium on transport and trafficking in the malaria-infected
erythrocyte. London, United Kingdom, 26-28 January 1999.
PMID- 10681170
TI - Dermatology blues--Society of Investigative Dermatology 60th Annual Meeting, 5-9
May 1999, Chicago, USA.
PMID- 10681171
TI - Hydroxyurea in psoriasis.
PMID- 10681172
TI - Patient information sheet used at St John's Institute of Dermatology. HYDROXYUREA
(Hydrea) Information Leaflet.
PMID- 10681173
TI - A sporadic form of hypertrichosis cubiti.
PMID- 10681174
TI - Pulsed dye laser treatment of subacute cutaneous lupus erythematosus.
PMID- 10681175
TI - Erosive pustular dermatosis of the scalp following cryotherapy and topical
tretinoin for actinic keratoses.
PMID- 10681176
TI - Jessner's lymphocytic infiltrate treated with auranofin.
PMID- 10681177
TI - Ventilation scintigraphy for the detection of bronchopleural fistulae.
PMID- 10681178
TI - Simple design for rapid self-injection ictal SPET during aura.
PMID- 10681179
TI - An investigation into the electro-physical characteristics of microbial cells
during the metabolism of toxic compounds under conditions of limited O2
availability.
AB - The purpose of the work reported here was to experimentally clarify the
interconnection between changes in the electro-physical characteristics of
microbial suspensions and processes of the metabolism of certain toxic compounds
(acrylamide and p-nitrophenol (PNP)) in cells containing enzyme systems of the
initial metabolism of these compounds. In this work, we used cells of two
strains, Acinetobacter calcoaceticum A-122 and Brevibacterium sp. 13PA, which are
capable of utilising PNP and acrylamide, respectively, as the sole source of
carbon. Suspensions of these cells exhibited appreciable decreases in the
magnitude of the electro-optical signal when the microbial metabolism of PNP and
acrylamide was inhibited under conditions of limited O2 supply. This attests to a
relationship between the electro-physical characteristics of microbial
suspensions and cellular metabolic reactions and also to the negligibly small
effect that the non-specific interaction of substrate with the cells has on the
suspensions' electro-optical properties.
PMID- 10681180
TI - The 1999 Thomas Hunt Morgan Medal. Salome G. Waelsch.
PMID- 10681181
TI - The 1999 Genetics Society of America Medal. Charles H. Langley.
PMID- 10681182
TI - The yeast HSM3 gene is not involved in DNA mismatch repair in rapidly dividing
cells.
PMID- 10681183
TI - The yeast HSM3 gene is involved in DNA mismatch repair in slowly dividing cells.
PMID- 10681184
TI - The 1999 George W. Beadle Medal. Michael Ashburner.
PMID- 10681185
TI - Epidemiology supports oral contraceptives as a risk factor in Crohn's disease.
PMID- 10681186
TI - The role of psychological and biological factors in postinfective gut
dysfunction.
PMID- 10681187
TI - Is isolated idiopathic pancreatitis associated with CFTR mutations?
PMID- 10681188
TI - Did prostaglandin E(2) stimulate glucose absorption in rat intestine?
PMID- 10681189
TI - Abstracts presented for the 31st annual meeting of the Society of Gynecologic
Oncologists. San Diego, California, February 5-9, 2000.
PMID- 10681190
TI - [Hypothesis--Origin of the parietal cells].
PMID- 10681191
TI - Diversion proctocolitis with granulomatous vasculitis in a patient without
inflammatory bowel disease.
PMID- 10681192
TI - Sarcomatous transformation of chromophobe cell renal carcinoma.
PMID- 10681193
TI - Vitamin A induced stellate cell hyperplasia and fibrosis in renal failure.
PMID- 10681194
TI - Mullerian adenosarcoma of the uterus in association with tamoxifen therapy.
PMID- 10681195
TI - Metastasizing hyalinizing spindle cell tumour with giant rosettes: report of a
case with long survival.
PMID- 10681196
TI - Exocyclic DNA Adducts in Mutagenesis and Carcinogenesis. Proceedings of the 2nd
international conference. Heidelberg, Germany, September 1998.
PMID- 10681197
TI - [Health economics: notes for a research agenda].
PMID- 10681198
TI - [The dreams and realities of the British National Health Service. Primary care as
a gateway to health services].
PMID- 10681199
TI - [The gatekeeper role of the general practitioner and the reform of the National
Health Service as seen from Barcelona, Spain].
PMID- 10681200
TI - [Toxic peripheral polyneuropathy outbreak in a labour environment].
PMID- 10681201
TI - [Use of nonparametric methods for controlling unseen confounding variables in
ecological time-series studies].
PMID- 10681202
TI - [Heinz Walther (1919-1999)].
PMID- 10681203
TI - [Professor Bernd-Rudiger Balda on his 60th birthday].
PMID- 10681204
TI - [Propionibacterium acnes--pathogenetic significance in sarcoidosis?].
PMID- 10681206
TI - Employment, starting salaries and educational indebtedness of 1999 graduates of
US veterinary medical colleges.
PMID- 10681207
TI - Is a large number of sputum specimens necessary for the bacteriological diagnosis
of tuberculosis?
PMID- 10681208
TI - Detection of Bordetella holmesii using Bordetella pertussis IS481 PCR assay.
PMID- 10681209
TI - Two Actinobacillus pleuropneumoniae serotype 8 reference strains in circulation.
PMID- 10681210
TI - Acute renal failure in an infant associated with cytotoxic Aeromonas sobria
isolated from patient's stool and from aquarium water as suspected source of
infection.
PMID- 10681211
TI - Rapid mini-preparation of fungal DNA for PCR.
PMID- 10681213
TI - Designs for life: the science of biomechanics. A tribute to Professor R. McNeill
Alexander FRS.
PMID- 10681212
TI - Obtaining unacceptable results in assays for quantitation of human
immunodeficiency virus type 1 RNA in plasma samples.
PMID- 10681214
TI - Attentional blink for color.
AB - Colored letters were presented by means of rapid serial visual presentation
(RSVP). Two letters (T1 and T2) were targets that required a speeded (T1) or
delayed (T2) response. T1 was shown on half of the trials. Two tasks were
performed in the experimental conditions. Task 1 required a discrimination
between 2 letters (when T1 was shown) or an indication that T1 was absent. In
Experiment 1, Task 2 was to detect the presence of a unique color in the RSVP
stream (e.g., green in a stream of alternating red and gray). In Experiment 2,
Task 2 was to report the color of the first colored letter to appear in the RSVP
stream. The lag between T1 and T2 in the RSVP stream was manipulated. Accuracy of
color reports in Task 2 was poor at shorter lags and improved as the lag was
lengthened in both experiments, demonstrating an attentional blink for chromatic
information. Theoretical implications of the results are discussed.
PMID- 10681215
TI - On the mitochondrial aspect of reactive oxygen species action in external
magnetic fields.
AB - Some retinoids or porphyrins can form radical pairs, alter transfer of electrons,
and increase synthesis of reactive oxygen species in the mitochondrial
respiratory chain. This leads to cell damage and apoptosis. We propose that co
application of an external static magnetic field of several to several hundreds
miliTesla (mT) can enhance those effects by further alteration of electron flow
in the mitochondrial respiratory chain, facilitation of forbidden transitions
from the triplet to the singlet state of retinoid or porphyrin radicals, and
modification of radical pair amount. Since electron flow in the mitochondrial
respiratory chain seems to possess fractal dynamics, the magnetic field can
initiate self- organization of the flow into more regular patterns, and create
optimal conditions for damage of cancer cells without any detriment for the
normal counterparts. External low magnetic field should improve effectiveness and
selectivity of retinoid chemoprevention or porphyrin photodynamic therapy.
PMID- 10681216
TI - The case in support of Gh therapy.
PMID- 10681217
TI - Vitamin A supplementation for extremely-low-birth-weight infants.
PMID- 10681218
TI - Cytomegalovirus infection and HIV-I disease progression in infants born to HIV-I
infected women.
PMID- 10681220
TI - Mississippi is blessed by HMO failure.
PMID- 10681219
TI - Autism and measles, mumps, and rubella vaccine: No epidemiological evidence for a
causal association.
PMID- 10681221
TI - Global epidemic of cardiovascular disease predicted.
PMID- 10681222
TI - Ochre suppressor transfer RNA restored dystrophin expression in mdx mice.
PMID- 10681223
TI - Reflections in mutation research. Reflections of Zhores Medvedev.
PMID- 10681224
TI - Transmyocardial laser revascularization.
PMID- 10681225
TI - Transmyocardial laser revascularization.
PMID- 10681226
TI - Mitochondrial disease in patients with exercise intolerance.
PMID- 10681227
TI - Mitochondrial disease in patients with exercise intolerance.
PMID- 10681228
TI - Virostatic therapy for advanced lymphoproliferation associated with the Epstein
Barr virus in an HIV-infected patient.
PMID- 10681229
TI - Nephropathy in type 2 diabetes.
PMID- 10681230
TI - Nephropathy in type 2 diabetes.
PMID- 10681231
TI - Nephropathy in type 2 diabetes.
PMID- 10681232
TI - Hypereosinophilic syndrome.
PMID- 10681233
TI - Hypereosinophilic syndrome.
PMID- 10681234
TI - An angiosarcoma in the left atrium.
PMID- 10681235
TI - Diversity convention in the balance.
PMID- 10681236
TI - Atmospheric chemistry. Better budgets for methyl halides.
PMID- 10681237
TI - Robert A. Swanson (1947-99)
PMID- 10681238
TI - [XXI National Congress of the Italian Society of Vascular Angiology and
Pathology. Bologna, 28 November-1 December 1999. Proceedings].
PMID- 10681239
TI - [Use of antithrombotic drugs in the treatment of peripheral occlusive arterial
diseases].
PMID- 10681240
TI - Risk factors for back pain incidence in industry: a prospective study.
PMID- 10681241
TI - The bee venom test: comparisons with the formalin test with injection of
different venoms.
PMID- 10681242
TI - Hemisensory impairment in patients with complex regional pain syndrome.
PMID- 10681243
TI - Resolution of psychological distress of whiplash patients following treatment by
radiofrequency neurotomy: a randomized, double-blind, placebo-controlled trial.
PMID- 10681244
TI - Absence of evidence is not evidence of absence (again)
PMID- 10681245
TI - Workshop on parenting methods to minimize disruptive behavior.
PMID- 10681246
TI - Workshop on practical and cost-effective issues of behavior management.
PMID- 10681247
TI - Workshop on choosing the setting and medication for the difficult child.
PMID- 10681248
TI - Evolution of the genetic covariance between male and female components of mate
recognition: an experimental test.
AB - The evolution of a positive genetic correlation between male and female
components of mate recognition systems will result as a consequence of
assortative mating and, in particular, is central to a number of theories of
sexual selection. Although the existence of such genetic correlations has been
investigated in a number of taxa, it has yet to be shown that such correlations
evolve and whether they may evolve as rapidly as suggested by sexual selection
models. In this study, I used a hybridization experiment to disrupt natural mate
recognition systems and then observed the subsequent evolutionary dynamics of the
genetic correlation between male and female components for 56 generations in
hybrids between Drosophila serrata and Drosophila birchii. The genetic
correlation between male and female components evolved from 0.388 at generation 5
to 1.017 at generation 37 and then declined to -0.040 after a further 19
generations. These results indicated that the genetic basis of the mate
recognition system in the hybrid populations evolved rapidly. The initial rapid
increase in the genetic correlation was consistent with the classic assumption
that male and female components will coevolve under sexual selection. The
subsequent decline in genetic correlation may be attributable to the fixation of
major genes, or, alternatively, may be a result of a cyclic evolutionary change
in mate recognition.
PMID- 10681249
TI - Phylogenetic approaches to nomenclature: a comparison based on a nemertean case
study.
AB - Phylogenetic approaches to biological nomenclature are becoming increasingly
common. Here I compare the behaviour of two such approaches, the phylogenetic
system of definition and the phylogenetic system of reference, when there is a
shift in the preference of phylogenetic hypotheses. The comparison is based on a
case study from nemertean systematics and is the first to compare two different
phylogenetic approaches throughout three stages of change, including two stages
of phylogenetic nomenclature. It is concluded that a phylogenetic system of
reference in combination with uninomials is superior in conveying phylogenetic
information.
PMID- 10681251
TI - [XLI Congress of the French National Society of Internal Medicine. Toulouse, 9-11
December 1999. Proceedings].
PMID- 10681250
TI - Total serum IgE and IgA antibody levels in healthy dogs of different breeds and
exposed to different environments.
AB - Total serum immunoglobulin (Ig) E and A levels were analysed in 233 healthy dogs
as basis for comparison with atopic dogs in future studies. They were measured by
ELISA in a group of non- colonised dogs of various breeds (group A) and three
groups of colonised dogs including one German Shepherd and two Beagle kennels
(groups B-D). IgE levels from non-colonised dogs were significantly higher than
the ones of German Shepherds and Beagles C (P<0.05). IgA levels were alike in all
groups except for the German Shepherds which displayed the lowest levels. Age and
sex were not identified as common significant cofactors for IgE and IgA levels in
all groups and IgE levels correlated negatively with IgA only in non-colonised
dogs. In conclusion, IgE and IgA levels seem to be mainly influenced by genetic
background. Thus use of total serum IgE as a diagnostic tool in the atopic dogs
required extensive family data and therefore appears most suitable for research
purposes within specific, well defined dog populations.
PMID- 10681252
TI - [The president's look back].
PMID- 10681253
TI - [Quality guidelines: are they applicable in the private office?].
PMID- 10681254
TI - [The debate for an incisor. The multidisciplinary approach in dental injuries.
The 12th Meeting of the Association of Former Students of the School of Dentistry
of Geneva, 30 September and 1 October 1999].
PMID- 10681255
TI - [Anonymous: a majolica plate representing Saint Apollonia. The BonaDent
Collection].
PMID- 10681256
TI - [The juridical aspects of quality management (quality assurance) in dentistry].
PMID- 10681257
TI - [Everything about intraoral video systems--part I. Advice on the purchase
decision and on use].
PMID- 10681258
TI - [Dental Health Assistance Switzerland].
PMID- 10681259
TI - [Periodontal risks in daily practice--the initiation of guided diagnosis. The
1999 congress of the SSP (Swiss Society for Periodontics) in Lugano].
PMID- 10681260
TI - [Prosthodontics on the threshold into the year 2000, the determination of its
status and the future prospects for dental practice. A report on the 2nd Easter
symposium of 10 April-17 April 1999 in Mallorca].
PMID- 10681261
TI - [Active specific immunotherapy (ASI) in colon cancer].
PMID- 10681262
TI - Risk factors for death from asthma.
PMID- 10681263
TI - Nebulised taurolidine and B cepacia bronchiectasis.
PMID- 10681264
TI - Effect of salmeterol on airway eosinophils.
PMID- 10681265
TI - Familial coagulation factor V deficiency caused by a novel 4 base pair insertion
in the factor V gene: factor V Stanford [erratum].
PMID- 10681266
TI - Ladislav Tauc (1926-1999)
PMID- 10681267
TI - [IV Conference on plant karyology and karyosystematics. St. Petersburg, May 25
27, 1999. Abstracts].
PMID- 10681268
TI - [Abstracts of papers and communications submitted to the International conference
"Free-radical processes: ecological, pharmacological and clinical aspects". St.
Petersburg, September 8-10, 1999].
PMID- 10681269
TI - B vitamins, homocysteine, and neurocognitive function in the elderly.
AB - Evidence of the importance of the B vitamins folic acid, vitamin B-12, and
vitamin B-6 for the well-being and normal function of the brain derives from data
showing neurologic and psychologic dysfunction in vitamin deficiency states and
in cases of congenital defects of one-carbon metabolism. The status of these
vitamins is frequently inadequate in the elderly and recent studies have shown
associations between loss of cognitive function or Alzheimer disease and
inadequate B vitamin status. The question that arises is whether these B vitamin
inadequacies contribute to such brain malfunctions or result from aging and
disease. From a theoretical standpoint, these inadequacies could give rise to
impairment of methylation reactions that are crucial to the health of brain
tissue. In addition or perhaps instead, these inadequacies could result in
hyperhomocysteinemia, a recently identified risk factor for occlusive vascular
disease, stroke, and thrombosis, any of which may result in brain ischemia.
Advances in the understanding of this putative relation between inadequate
vitamin status and loss of cognitive function in the elderly are likely to be
slow and may depend on the outcomes of both prospective studies and longitudinal
studies in which nutritional intervention is provided before cognitive decline
occurs.
PMID- 10681270
TI - Oxidative stress and Alzheimer disease.
AB - Research in the field of molecular biology has helped to provide a better
understanding of both the cascade of biochemical events that occurs with
Alzheimer disease (AD) and the heterogeneous nature of the disease. One
hypothesis that accounts for both the heterogeneous nature of AD and the fact
that aging is the most obvious risk factor is that free radicals are involved.
The probability of this involvement is supported by the fact that neurons are
extremely sensitive to attacks by destructive free radicals. Furthermore, lesions
are present in the brains of AD patients that are typically associated with
attacks by free radicals (eg, damage to DNA, protein oxidation, lipid
peroxidation, and advanced glycosylation end products), and metals (eg, iron,
copper, zinc, and aluminum) are present that have catalytic activity that produce
free radicals. beta-Amyloid is aggregated and produces more free radicals in the
presence of free radicals; beta-amyloid toxicity is eliminated by free radical
scavengers. Apolipoprotein E is subject to attacks by free radicals, and
apolipoprotein E peroxidation has been correlated with AD. In contrast,
apolipoprotein E can act as a free radical scavenger and this behavior is isoform
dependent. AD has been linked to mitochondrial anomalies affecting cytochrome-c
oxidase, and these anomalies may contribute to the abnormal production of free
radicals. Finally, many free radical scavengers (eg, vitamin E, selegeline, and
Ginkgo biloba extract EGb 761) have produced promising results in relation to AD,
as has desferrioxamine-an iron-chelating agent-and antiinflammatory drugs and
estrogens, which also have an antioxidant effect.
PMID- 10681271
TI - Vitamin E and Alzheimer disease: the basis for additional clinical trials.
AB - Many lines of evidence suggest that oxidative stress is important in the
pathogenesis of Alzheimer disease. In particular, beta-amyloid, which is found
abundantly in the brains of Alzheimer disease patients, is toxic in neuronal cell
cultures through a mechanism involving free radicals. Vitamin E prevents the
oxidative damage induced by beta-amyloid in cell culture and delays memory
deficits in animal models. A placebo-controlled, clinical trial of vitamin E in
patients with moderately advanced Alzheimer disease was conducted by the
Alzheimer's Disease Cooperative Study. Subjects in the vitamin E group were
treated with 2000 IU (1342 alpha-tocopherol equivalents) vitamin E/d. The results
indicated that vitamin E may slow functional deterioration leading to nursing
home placement. A new clinical trial is planned that will examine whether vitamin
E can delay or prevent a clinical diagnosis of Alzheimer disease in elderly
persons with mild cognitive impairment.
PMID- 10681272
TI - Weight loss in Alzheimer disease.
AB - BACKGROUND: Epidemiologic studies have shown that weight loss is commonly
associated with Alzheimer disease (AD) and is a manifestation of the disease
itself. The etiology of weight loss in AD appears multifactorial. Hypotheses to
explain the weight loss have been suggested (eg, atrophy of the mesial temporal
cortex, biological disturbances, and higher energy expenditure); however, none
have been proven. OBJECTIVE: In the first part of this article, we describe
weight loss in AD (epidemiologic data and hypotheses to explain weight loss and
anorexia in AD). In the second part we report the results of a longitudinal study
of the changes in nutritional variables in a cohort of patients with a probable
diagnosis of AD. DESIGN: We followed subjects with AD (based on criteria of the
National Institute of Neurological and Communicative Disorders and
Stroke/Alzheimer's Disease and Related Disorders Association) who were recruited
from the Alzheimer's Disease Center in Toulouse. All subject underwent a
nutritional, neuropsychologic, and functional evaluation. The Zarit scales were
used to assess caregiver burden and caregiver reactions to the patients'
behavioral and autonomic disorders. RESULTS: We showed that only results of the
Burden Interview and the Memory and Behavior Problems Checklist, which explored
caregiver burden, predicted weight loss in AD. It is possible that caregivers who
consider themselves overburdened by the disease process are not willing to invest
adequate resources to allow AD patients to properly nourish themselves.
CONCLUSION: Nutritional education programs for the caregivers of AD patients seem
to be the best way to prevent weight loss and improve the nutritional status of
these patients.
PMID- 10681273
TI - Alzheimer disease: protective factors.
AB - Approximately 6-8% of all persons aged >65 y have Alzheimer disease and the
prevalence of the disease is increasing. Any intervention strategy aimed at
decreasing risks or delaying the onset of the disease will therefore have a
substantial effect on health care costs. Nutrition seems to be one of the factors
that may play a protective role in Alzheimer disease. Many studies suggest that
oxidative stress and the accumulation of free radicals are involved in the
pathophysiology of the disease. Several studies have shown the existence of a
correlation between cognitive skills and the serum concentrations of folate,
vitamin B-12, vitamin B-6, and, more recently, homocysteine. However, nutritional
factors have to be studied not alone but with the other factors related to
Alzheimer disease: genetics, estrogen, antiinflammatory drug use, and
socioeconomic variables. The objective of this article was to review recent
studies in this field.
PMID- 10681275
TI - Changes in definitions of clinical staging for carcinoma of the cervix and ovary:
International Federation of Gynecology and Obstetrics.
PMID- 10681276
TI - Proceedings of an International Symposium on the Mechanisms and Management of
Allergic Disease to mark the 30th Anniversary of Allergopharma Joachim Ganzer KG.
Hamburg, Germany, September 24-26, 1999.
PMID- 10681274
TI - Energy expenditure, energy intake, and weight loss in Alzheimer disease.
AB - Alzheimer disease is one of the leading causes of death among older individuals.
Unexplained weight loss and cachexia are frequent clinical findings in patients
with Alzheimer disease. Thus, it has been postulated that Alzheimer disease may
be associated with dysfunction in body weight regulation. This brief review
examines the interrelations among energy intake, energy expenditure, and body
composition in Alzheimer disease. We explored whether abnormally high daily
energy expenditures, low energy intakes, or both contribute to unexplained weight
loss and a decline in nutritional status. Specifically, we considered studies
that examined energy intake, body composition, and daily energy expenditure and
its components. The application of doubly labeled water and indirect calorimetry
to understand the etiology of wasting has increased our knowledge regarding the
relation among energy expenditure, physical activity levels, and body composition
in Alzheimer disease patients. Although the number of studies are limited,
results do not support the notion that a hypermetabolic state contributes to
unexplained weight loss in Alzheimer disease, even in cachectic patients. Recent
findings are presented suggesting an association between abnormally elevated
levels of physical activity energy expenditure and elevated appendicular skeletal
muscle mass and energy intake in Alzheimer disease patients. Clinical strategies
aimed at developing lifestyle and dietary interventions to maintain adequate
energy intake, restore energy balance, and maintain skeletal muscle mass should
be a future area of investigation in Alzheimer disease research.
PMID- 10681277
TI - Opioid-induced breathing patterns disappear from view.
PMID- 10681278
TI - Profound motor blockade with epidural ropivacaine.
PMID- 10681279
TI - Effects of infant birthweight and maternal body mass index in pregnancy on
components of the insulin resistance syndrome in China.
AB - BACKGROUND: Reduced birthweight is associated with increased risk for the insulin
resistance syndrome. Part of this risk is hypothesized to originate from
undernutrition in utero. The prevalence of the insulin resistance syndrome
increases in countries that undergo the transition from chronic malnutrition to
adequate nutrition, when postnatal nutrition improves more rapidly than prenatal
nutrition. OBJECTIVE: To determine whether the components of the insulin
resistance syndrome are associated with reduced fetal growth and maternal
undernutrition. DESIGN: A nonconcurrent, prospective study of men and women whose
mothers' heights and weights were recorded during pregnancy. SETTING: Beijing,
China. PARTICIPANTS: 627 men and women (mean age, 45 years) whose mothers'
obstetric records were preserved. MEASUREMENTS: Adult offspring's blood pressure,
plasma glucose levels, insulin levels, and lipid concentrations during an oral
glucose tolerance test. The main explanatory measurements were mothers' body mass
index during pregnancy and offspring's birthweight and adult size. RESULTS: After
adjustment for sex and current body mass index, low birthweight was associated
with elevated plasma glucose levels, insulin levels, triglyceride concentrations,
and blood pressure. For every 1-kg increase in birthweight, systolic blood
pressure decreased by 2.9 mm Hg (95% CI, 0.3 to 5.4 mm Hg) and the 2-hour plasma
glucose level decreased by 5.1% (CI, 0.7% to 9.3%). Low maternal body mass index
in early and late pregnancy was associated with elevated levels of plasma
glucose, insulin, and triglycerides in adult offspring but was not associated
with elevated blood pressure. CONCLUSIONS: Risk for the insulin resistance
syndrome may be partially established through low maternal body mass before
pregnancy and consequent fetal undernutrition. This risk is independent of that
associated with adult obesity. In developing countries such as China, improved
nutrition in girls and young women may offer long-term benefits to offspring.
PMID- 10681280
TI - Screening for hereditary hemochromatosis in siblings and children of affected
patients. A cost-effectiveness analysis.
AB - BACKGROUND: Screening for hereditary hemochromatosis is traditionally done by
using serum iron studies. However, mutation analysis of the hemochromatosis
associated HFE gene has recently become available. OBJECTIVE: To compare the cost
effectiveness of no screening with four screening strategies that incorporate HFE
gene testing or serum iron studies. DESIGN: Cost-effectiveness analysis. DATA
SOURCES: Published literature. TARGET POPULATION: Siblings and children of an
affected proband. TIME HORIZON: Lifetime from 10 years of age (children) or 45
years of age (siblings). PERSPECTIVE: Societal. INTERVENTION: 1) Serum iron
studies. 2) Gene testing of the proband. If the proband is homozygous (C82Y+/+),
the spouse undergoes gene testing; if he or she is heterozygous (C82Y+/-), the
children undergo gene testing. 3) Gene testing of the proband; if he or she is
homozygous, relatives undergo gene testing. 4) Direct gene testing of relatives.
OUTCOME MEASURES: Cost per life-year saved and incremental cost-effectiveness
ratio. RESULTS OF BASE-CASE ANALYSIS: In children, HFE gene testing of the
proband was the most cost-effective strategy for screening one child (incremental
cost-effectiveness ratio, $508 per life-year saved). HFE gene testing of the
proband followed by testing of the spouse was the most cost-effective strategy
for screening two or more children (incremental cost-effectiveness ratio, $3665
per life-year saved). In siblings, all screening strategies were dominant
compared with no screening. Strategies using HFE gene testing were less costly
than serum iron studies. RESULTS OF SENSITIVITY ANALYSIS: Despite varying the
prevalence of mutations and regardless of the cost of the genetic test in one-
and two-way sensitivity analyses, HFE gene testing remained cost-effective.
CONCLUSIONS: HFE gene testing for the C282Y mutation is a cost-effective method
of screening relatives of patients with hereditary hemochromatosis.
PMID- 10681281
TI - Subclinical hypothyroidism is an independent risk factor for atherosclerosis and
myocardial infarction in elderly women: the Rotterdam Study.
AB - BACKGROUND: Overt hypothyroidism has been found to be associated with
cardiovascular disease. Whether subclinical hypothyroidism and thyroid
autoimmunity are also risk factors for cardiovascular disease is controversial.
OBJECTIVE: To investigate whether subclinical hypothyroidism and thyroid
autoimmunity are associated with aortic atherosclerosis and myocardial infarction
in postmenopausal women. DESIGN: Population-based cross-sectional study. SETTING:
A district of Rotterdam, The Netherlands. PARTICIPANTS: Random sample of 1149
women (mean age +/- SD, 69.0 +/- 7.5 years) participating in the Rotterdam Study.
MEASUREMENTS: Data on thyroid status, aortic atherosclerosis, and history of
myocardial infarction were obtained at baseline. Subclinical hypothyroidism was
defined as an elevated thyroid-stimulating hormone level (>4.0 mU/L) and a normal
serum free thyroxine level (11 to 25 pmol/L [0.9 to 1.9 ng/dL]). In tests for
antibodies to thyroid peroxidase, a serum level greater than 10 IU/mL was
considered a positive result. RESULTS: Subclinical hypothyroidism was present in
10.8% of participants and was associated with a greater age-adjusted prevalence
of aortic atherosclerosis (odds ratio, 1.7 [95% CI, 1.1 to 2.6]) and myocardial
infarction (odds ratio, 2.3 [CI, 1.3 to 4.0]). Additional adjustment for body
mass index, total and high-density lipoprotein cholesterol level, blood pressure,
and smoking status, as well as exclusion of women who took beta-blockers, did not
affect these estimates. Associations were slightly stronger in women who had
subclinical hypothyroidism and antibodies to thyroid peroxidase (odds ratio for
aortic atherosclerosis, 1.9 [CI, 1.1 to 3.6]; odds ratio for myocardial
infarction, 3.1 [CI, 1.5 to 6.3]). No association was found between thyroid
autoimmunity itself and cardiovascular disease. The population attributable risk
percentage for subclinical hypothyroidism associated with myocardial infarction
was within the range of that for known major risk factors for cardiovascular
disease. CONCLUSION: Subclinical hypothyroidism is a strong indicator of risk for
atherosclerosis and myocardial infarction in elderly women.
PMID- 10681282
TI - Positive results on tests for steatorrhea in persons consuming olestra potato
chips.
AB - BACKGROUND: Olestra is a nonabsorbable fat substitute that consists of fatty
acids esterified to a sucrose molecule. OBJECTIVE: To determine the effect of
olestra consumption on measurements of fecal fat excretion. DESIGN: Controlled
cross-over trial. SETTING: Clinical research center and outpatient research
laboratory. PARTICIPANTS: 10 healthy volunteers. INTERVENTION: On days 1 to 6 of
the study, participants consumed 5 oz of conventional potato chips per day; on
days 7 to 12, they consumed 5 oz of potato chips containing 40 g of olestra per
day. MEASUREMENTS: Quantitative measurement of fecal fat by the van de Kamer
titration, van de Kamer gravimetric, and Jeejeebhoy gravimetric methods and
qualitative assessment of fecal fat by Sudan III staining. RESULTS: Excellent
correlation was seen among the three quantitative assays, but the van de Kamer
titration method yielded lower measurements than the two gravimetric methods.
When participants consumed 40 g of olestra per day, the excretion of fecal fat
increased to levels observed in patients with steatorrhea caused by the
malabsorption syndrome. CONCLUSION: Consumption of olestra can cause false
positive results on tests for steatorrhea and may therefore lead to an erroneous
diagnosis of the malabsorption syndrome.
PMID- 10681283
TI - Fatal hyperammonemia after orthotopic lung transplantation.
AB - BACKGROUND: A case of fatal hyperammonemia complicating orthotopic lung
transplantation was previously reported. OBJECTIVE: To describe the incidence,
clinical features, and treatment of hyperammonemia associated with orthotopic
lung transplantation. DESIGN: Retrospective cohort analysis. SETTING: Academic
medical center and lung transplantation center in Philadelphia, Pennsylvania.
PATIENTS: 145 sequential adult patients who underwent orthotopic lung
transplantation. MEASUREMENTS: Plasma ammonium levels. RESULTS: Six of the 145
patients who had had orthotopic lung transplantation developed hyperammonemia,
all within the first 26 days after transplantation. The 30-day post
transplantation mortality rate was 67% for patients with hyperammonemia compared
with 17% for those without hyperammonemia (P = 0.01). Development of major
gastrointestinal complications (P = 0.03), use of total parenteral nutrition (P <
0.001), and lung transplantation for primary pulmonary hypertension (P = 0.045)
were associated with hyperammonemia. CONCLUSIONS: Hyperammonemia is a potentially
fatal event occurring after orthotopic lung transplantation. It is associated
with high nitrogen load, concurrent medical stressors, primary pulmonary
hypertension, and hepatic glutamine synthetase deficiency.
PMID- 10681284
TI - Update in critical care medicine.
PMID- 10681285
TI - Pathogenesis, natural history, treatment, and prevention of hepatitis C.
AB - Approximately 4 million persons in the United States and probably more than 100
million persons worldwide are infected with hepatitis C virus. The virus has the
unique ability to cause persistent infection in susceptible hosts after
parenteral or percutaneous transmission, and its underlying mechanisms are not
well understood. The immunologic correlates of protection and viral clearance and
the pathogenesis of liver injury are yet to be defined, but recent studies
suggest the importance of cell-mediated immune responses. Although 70% to 80% of
infected persons become chronic carriers, most have relatively mild disease with
slow progression. However, chronic and progressive hepatitis C carries
significant morbidity and mortality and is a major cause of cirrhosis, end-stage
liver disease, and liver cancer. Development of an effective hepatitis C virus
vaccine is not imminent, but recent advances in technology and basic knowledge of
molecular virology and immunology have engendered novel approaches to the
fundamental problems encountered in vaccine development. Current therapy for
hepatitis C, although effective in some patients, is problematic and still
evolving. Advances in modern biology and immunology promise new therapies for
this important disease.
PMID- 10681286
TI - The case for more cautious, patient-focused antiretroviral therapy.
AB - Many clinicians who care for patients with HIV infection are dissatisfied with
the existing recommendations on antiretroviral therapy. Current practice focuses
on the early suppression of viremia, yet the outcome of that approach may not be
in the best interest of individual patients or populations. The major goal of HIV
therapy is to maintain the long-term health of the patient while avoiding drug
related toxicity and preserving viable future treatment options. Recent studies
have challenged the principles on which recommendations for early, aggressive
treatment were based. Key studies that lead to licensure of antiretroviral
medications usually involve short-term results in treatment-naive patients; it is
difficult to apply these results to long-term management of therapy-experienced
patients. Early, aggressive therapy often prematurely exposes patients to risks
for medication-related side effects and resistance. A more cautious, patient
focused, long-term approach to therapy would help foster studies of alternate
strategies, such as delayed initiation of therapy, protease-sparing therapy,
class-sparing therapy, planned drug interruptions, switches in therapy, and
immune-based therapy. It is time for clinicians to rethink their approach to the
treatment of HIV infection.
PMID- 10681287
TI - Eugenic sterilization and a qualified Nazi analogy: the United States and
Germany, 1930-1945.
AB - In the United States and Germany before World War II, physicians participated in
state-authorized eugenic sterilization programs in an attempt to prevent persons
deemed to possess undesirable heritable characteristics from propagating. A
comparison of U.S. and German histories reveals similarities that argue against
easy dismissal of a Nazi analogy. On the basis of a review of editorials in New
England Journal of Medicine and Journal of the American Medical Association from
1930 to 1945 it is difficult to accept the suggestion that the alliance between
the medical profession and the eugenics movement in the United States was short
lived. Comparison of the histories of the eugenic sterilization campaigns in the
United States and Nazi Germany reveals important similarities of motivation,
intent, and strategy and differences that explain why support for eugenic
sterilization in the United States gradually weakened. The eugenics movement in
Germany was influenced by economic crisis, radical nationalism, Hitler's
totalitarianism, and the medical profession's willing participation and
attraction to Nazism for financial and ideological reasons. In the United States,
a combination of public unease, Roman Catholic opposition, federal democracy,
judicial review, and critical scrutiny by the medical profession reversed the
momentum of the eugenics movement and led to the conclusion that eugenic
sterilization should be voluntary.
PMID- 10681288
TI - Antiretroviral therapy: time to think strategically.
PMID- 10681289
TI - The eyes of the Asp.
PMID- 10681290
TI - Functional somatic syndromes.
PMID- 10681291
TI - Functional somatic syndromes.
PMID- 10681292
TI - Functional somatic syndromes.
PMID- 10681293
TI - Functional somatic syndromes.
PMID- 10681294
TI - Functional somatic syndromes.
PMID- 10681296
TI - Functional somatic syndromes.
PMID- 10681295
TI - Functional somatic syndromes.
PMID- 10681297
TI - Functional somatic syndromes.
PMID- 10681298
TI - Functional somatic syndromes.
PMID- 10681299
TI - Protease inhibitors do not interfere with prohormone processing.
PMID- 10681300
TI - Rapid identification of pathogens in blood.
PMID- 10681301
TI - The role of integrin-mediated cell adhesion in health and disease: integrin-based
therapy in clinical medicine.
PMID- 10681302
TI - In celebration of a life: a meeting of his fellows and friends. John J. Conley
memorial. New York City, New York, USA. November 19, 1999.
PMID- 10681303
TI - Reduced inhibitory capacity in prefrontal cortex of schizophrenics.
PMID- 10681304
TI - Neural circuitry of the prefrontal cortex in schizophrenia.
PMID- 10681305
TI - In pursuit of the molecular neuropathology of schizophrenia.
PMID- 10681306
TI - Carrier-mediated delivery of 9-(2-phosphonylmethoxyethyl)adenine to parenchymal
liver cells: a novel therapeutic approach for hepatitis B.
AB - Our aim is to selectively deliver 9-(2-phosphonylmethoxyethyl)adenine (PMEA) to
parenchymal liver cells, the primary site of hepatitis B virus (HBV) infection.
Selective delivery is necessary because PMEA, which is effective against HBV in
vitro, is hardly taken up by the liver in vivo. Lactosylated reconstituted high
density lipoprotein (LacNeoHDL), a lipid particle that is specifically
internalized by parenchymal liver cells via the asialoglycoprotein receptor, was
used as the carrier. PMEA could be incorporated into the lipid moiety of
LacNeoHDL by attaching, via an acid-labile bond, lithocholic acid-3alpha-oleate
to the drug. The uptake of the lipophilic prodrug (PMEA-LO) by the liver was
substantially increased after incorporation into LacNeoHDL. Thirty minutes after
injection of [(3)H]PMEA-LO-loaded LacNeoHDL into rats, the liver contained 68.9%
+/- 7.7% of the dose (free [(3)H]PMEA, <5%). Concomitantly, the uptake by the
kidney was reduced to <2% of the dose (free [(3)H]PMEA, >45%). The hepatic uptake
of PMEA-LO-loaded LacNeoHDL occurred mainly by parenchymal cells (88.5% +/- 8.2%
of the hepatic uptake). Moreover, asialofetuin inhibited the liver association by
>75%, indicating uptake via the asialoglycoprotein receptor. The acid-labile
linkage in PMEA-LO, designed to release PMEA during lysosomal processing of the
prodrug-loaded carrier, was stable at physiological pH but was hydrolyzed at
lysosomal pH (half-life, 60 to 70 min). Finally, subcellular fractionation
indicates that the released PMEA is translocated to the cytosol, where it is
converted into its active diphosphorylated metabolite. In conclusion, lipophilic
modification and incorporation of PMEA into LacNeoHDL improves the biological
fate of the drug and may lead to an enhanced therapeutic efficacy against chronic
hepatitis B.
PMID- 10681307
TI - Nasal carriage in Vietnamese children of Streptococcus pneumoniae resistant to
multiple antimicrobial agents.
AB - Resistance to antimicrobial agents in Streptococcus pneumoniae is increasing
rapidly in many Asian countries. There is little recent information concerning
resistance levels in Vietnam. A prospective study of pneumococcal carriage in 911
urban and rural Vietnamese children, of whom 44% were nasal carriers, was
performed. Carriage was more common in children <5 years old than in those >/=5
years old (192 of 389 [49.4%] versus 212 of 522 [40.6%]; P, 0.01). A total of 136
of 399 isolates (34%) had intermediate susceptibility to penicillin (MIC, 0.1 to
1 mg/liter), and 76 of 399 isolates (19%) showed resistance (MIC, >1.0 mg/liter).
A total of 54 of 399 isolates (13%) had intermediate susceptibility to
ceftriaxone, and 3 of 399 isolates (1%) were resistant. Penicillin resistance was
21.7 (95% confidence interval, 7.0 to 67.6) times more common in urban than in
rural children (35 versus 2%; P, <0.001). More than 40% of isolates from urban
children were also resistant to erythromycin, trimethoprim-sulfamethoxazole,
chloramphenicol, and tetracycline. Penicillin resistance was independently
associated with an urban location when the age of the child was controlled for.
Multidrug resistance (resistance to three or more antimicrobial agent groups) was
present in 32% of isolates overall but in 39% of isolates with intermediate
susceptibility to penicillin and 86% of isolates with penicillin resistance. The
predominant serotypes of the S. pneumoniae isolates were 19, 23, 14, 6, and 18.
Almost half of the penicillin-resistant isolates serotyped were serotype 23, and
these isolates were often multidrug resistant. This study suggests that
resistance to penicillin and other antimicrobial agents is common in carriage
isolates of S. pneumoniae from children in Vietnam.
PMID- 10681308
TI - In vitro activities of novel trans-3,5-disubstituted pyrrolidinylthio-1beta
methylcarbapenems with potent activities against methicillin-resistant
Staphylococcus aureus and Pseudomonas aeruginosa.
AB - The in vitro activities of the novel 1beta-methylcarbapenems J-111, 225, J
114,870, and J-114,871, which have a structurally unique side chain that consists
of a trans-3,5-disubstituted 5-arylpyrrolidin-3-ylthio moiety at the C-2
position, were compared with those of reference antibiotics. Among isolates of
both methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant
coagulase-negative staphylococci (MRCoNS), 90% were inhibited by J-111,347
(prototype), J-111,225, J-114,870, and J-114,871 at concentrations of 2, 4, 4,
and 4 microgram/ml (MICs at which 90% of isolates are inhibited [MIC(90)s]),
respectively, indicating that these agents were 32- to 64-fold more potent than
imipenem, which has an MIC(90) of 128 microgram/ml. Although these drugs were
less active in vitro than vancomycin, which had MIC(90)s of 1 and 2 microgram/ml
for MRSA and MRCoNS, respectively, the new carbapenems displayed better killing
kinetics than vancomycin. The potent anti-MRSA activity was ascribed to the
excellent affinities of the new carbapenems for penicillin-binding protein 2a of
MRSA. Since the new carbapenems also exhibited good activity against gram
positive and -negative bacteria including clinically important pathogens such as
penicillin-resistant Streptococcus pneumoniae, Haemophilus influenzae, members of
the family Enterobacteriaceae, Pseudomonas aeruginosa, and Clostridium difficile,
as well as MRSA, the novel carbapenems are worthy of further evaluation.
PMID- 10681309
TI - Differential effects of antiretroviral nucleoside analogs on mitochondrial
function in HepG2 cells.
AB - Numerous studies have reported effects of antiviral nucleoside analogs on
mitochondrial function, but they have not correlated well with the observed toxic
side effects. By comparing the effects of the five Food and Drug Administration
approved anti-human immunodeficiency virus nucleoside analogs, zidovudine (3'
azido-3'-deoxythymidine) (AZT), 2',3'-dideoxycytidine (ddC), 2', 3'
dideoxyinosine (ddI), 2',3'-didehydro-2',3'-deoxythymidine (d4T), and beta-L
2',3'-dideoxy-3'-thiacytidine (3TC), as well as the metabolite of AZT, 3'-amino
3'-deoxythymidine (AMT), on mitochondrial function in a human hepatoma cell line,
this issue has been reexamined. Evidence for a number of mitochondrial defects
with AZT, ddC, and ddI was found, but only AZT induced a marked rise in lactic
acid levels. Only in mitochondria isolated from AZT (50 microM)-treated cells was
significant inhibition of cytochrome c oxidase and citrate synthase found. Our
investigations also demonstrated that AZT, d4T, and 3TC did not affect the
synthesis of the 11 polypeptides encoded by mitochondrial DNA, while ddC caused
70% reduction of total polypeptide content and ddI reduced by 43% the total
content of 8 polypeptides (including NADH dehydrogenase subunits 1, 2, 4, and 5,
cytochrome c oxidase subunits I to III, and cytochrome b). We hypothesize that in
hepatocytes the reserve capacity for mitochondrial respiration is such that
inhibition of respiratory enzymes is unlikely to become critical. In contrast,
the combined inhibition of the citric acid cycle and electron transport greatly
enhances the dependence of the cell on glycolysis and may explain why apparent
mitochondrial dysfunction is more prevalent with AZT treatment.
PMID- 10681310
TI - Consequences of interaction of a lipophilic endotoxin antagonist with plasma
lipoproteins.
AB - E5531, a novel synthetic lipid A analogue, antagonizes the toxic effects of
lipopolysaccharide, making it a potential intravenously administered therapeutic
agent for the treatment of sepsis. This report describes the distribution of
E5531 in human blood and its activity when it is associated with different
lipoprotein subclasses. After in vitro incubation of [(14)C]E5531 with blood, the
great majority (>92%) of material was found in the plasma fraction. Analysis by
size-exclusion and affinity chromatographies and density gradient centrifugation
indicates that [(14)C]E5531 binds to lipoproteins, primarily high-density
lipoproteins (HDLs), with distribution into low-density lipoproteins (LDLs) and
very low density lipoproteins (VLDLs) being dependent on the plasma LDL or VLDL
cholesterol concentration. Similar results were also seen in a limited study of
[(14)C]E5531 administration to human volunteers. The potency of E5531 in freshly
drawn human blood directly correlates to increasing LDL cholesterol levels.
Finally, preincubation of E5531 with plasma or purified lipoproteins indicated
that binding to HDL resulted in a time-dependent loss of drug activity. This loss
in activity was not observed with drug binding to LDLs or to VLDLs or
chylomicrons. Taken together, these results indicate that E5531 binds to plasma
lipoproteins, making its long-term antagonistic potency dependent on the plasma
lipoprotein composition.
PMID- 10681311
TI - Effect of proinflammatory cytokines on the interplay between roxithromycin, HMR
3647, or HMR 3004 and human polymorphonuclear neutrophils.
AB - Cytokines, the hallmarks of infectious and inflammatory diseases, modify
phagocyte activities and thus may interfere with the immunomodulating properties
of antibacterial agents. We have investigated whether various proinflammatory
cytokines (interleukin 1 [IL-1], IL-6, IL-8, gamma interferon, tumor necrosis
factor alpha [TNF-alpha], and granulocyte-macrophage colony-stimulating factor
[GM-CSF]) modify two macrolide properties, i.e., inhibition of oxidant production
by polymorphonuclear neutrophils (PMN) and cellular uptake. Roxithromycin and two
ketolides, HMR 3647 and HMR 3004, were chosen as the test agents. TNF-alpha and
GM-CSF (but not the other cytokines) decreased the inhibitory effect of HMR 3647
only on oxidant production by PMN. Fifty percent inhibitory concentrations were,
however, in the same range in control and cytokine-treated cells (about 60 to 70
microgram/ml), suggesting that HMR 3647 acts downstream of the priming effect of
cytokines. In contrast, the impairment of oxidant production by roxithromycin and
HMR 3004 was unchanged (or increased) in cytokine-treated cells. This result
suggests that HMR 3004 (the strongest inhibitory drug, likely owing to its
quinoline side chain) and roxithromycin act on a cellular target upstream of
cytokine action. In addition, TNF-alpha and GM-CSF significantly (albeit
moderately) impaired (by about 20%) the uptake of the three molecules by PMN. The
inhibitory effect of these two cytokines seems to be related to activation of the
p38 mitogen-activated protein kinase. Our data also illuminate the mechanism
underlying macrolide uptake: protein kinase A- and tyrosine kinase-dependent
phosphorylation seems to be necessary for optimal uptake, while protein kinase C
activation impairs it. The relevance of our data to the clinical setting requires
further investigations, owing to the complexity of the cytokine cascade during
infection and inflammation.
PMID- 10681312
TI - Mechanism of uptake of a cationic water-soluble pyridinium zinc phthalocyanine
across the outer membrane of Escherichia coli.
AB - Previous studies have shown that a cationic water-soluble pyridinium zinc
phthalocyanine (PPC) is a powerful photosensitizer that is able to inactivate
Escherichia coli. In the current work incubation of E. coli cells with PPC in the
dark caused alterations in the outer membrane permeability barrier of the cells,
rendering the bacteria much more sensitive to hydrophobic compounds, with little
effect seen with hydrophilic compounds. Addition of Mg(2+) to the medium prior to
incubation of the cells with PPC prevented these alterations in the outer
membrane permeability barrier. The presence of Mg(2+) in the medium also
prevented the photoinactivation of E. coli cells with PPC. These results are
consistent with the hypothesis that PPC gains access across the outer membrane of
E. coli cells via the self-promoted uptake pathway, a mechanism of uptake
postulated for the uptake of other cationic compounds across the outer membranes
of gram-negative bacteria.
PMID- 10681313
TI - pncA mutations as a major mechanism of pyrazinamide resistance in Mycobacterium
tuberculosis: spread of a monoresistant strain in Quebec, Canada.
AB - Pyrazinamide (PZA) is an important first-line tuberculosis drug that is part of
the currently used short-course tuberculosis chemotherapy. PZA is a prodrug that
has to be converted to the active form pyrazinoic acid by pyrazinamidase (PZase)
activity, encoded by the pncA gene of Mycobacterium tuberculosis, and loss of
PZase activity is associated with PZA resistance. To further define the genetic
basis of PZA resistance and determine the frequency of PZA-resistant strains
having pncA mutations, we sequenced the pncA gene from a panel of 59 PZA
resistant clinical isolates from Canada, the United States, and Korea. Two
strains that did not contain pncA mutations and had positive PZase turned out to
be falsely resistant. Three PZase-negative strains (MIC, >900 microgram of PZA
per ml) and one PZase-positive strain (strain 9739) (MIC, >300 microgram of PZA
per ml) did not have pncA mutations. The remaining 53 of the 57 PZA-resistant
isolates had pncA mutations, confirming that pncA mutation is the major mechanism
of PZA resistance. Various new and diverse mutations were found in the pncA gene.
Interestingly, 20 PZA-monoresistant strains and 1 multidrug-resistant isolate
from Quebec, Canada, all had the same pncA mutation profile, consisting of an 8
nucleotide deletion and an amino acid substitution of Arg140-->Ser. Strain typing
indicated that these strains are highly related and share almost identical IS6110
patterns. These data strongly suggest the spread of a PZA-monoresistant strain,
which has not previously been described.
PMID- 10681314
TI - Antibacterial efficacy of gentamicin encapsulated in pH-sensitive liposomes
against an in vivo Salmonella enterica serovar typhimurium intracellular
infection model.
AB - Encapsulation of gentamicin in liposomes can be used to achieve intracellular
delivery and broaden the clinical utility of this drug. We have previously
described a novel, rationally designed, pH-sensitive liposomal carrier for
gentamicin that has superior in vitro efficacy against intracellular infections
compared to the efficacies of both free gentamicin and non-pH-sensitive liposomal
controls. This liposomal carrier demonstrated pH-sensitive fusion that was
dependent on the presence of unsaturated phosphatidylethanolamine (PE) and the pH
sensitive lipid N-succinyldioleoyl-PE. The pharmacokinetics and biodistribution
of the free and liposomal gentamicin were examined in mice bearing a systemic
Salmonella enterica serovar Typhimurium infection. Encapsulation of gentamicin in
pH-sensitive liposomes significantly increased the concentrations of the drug in
plasma compared to those of free gentamicin. Furthermore, the levels of
accumulation of drug in the infected liver and spleen were increased by 153- and
437-fold, respectively, as a result of liposomal encapsulation. The increased
accumulation of gentamicin in the liver and spleen effected by liposomal delivery
was associated with 10(4)-fold greater antibacterial activity than that
associated with free gentamicin in a murine salmonellosis model. These pH
sensitive liposomal antibiotic carriers with enhanced in vitro activity could be
used to improve both in vivo intracellular drug delivery and biological activity.
PMID- 10681315
TI - Efficacy of liposomal amphotericin B with prolonged circulation in blood in
treatment of severe pulmonary aspergillosis in leukopenic rats.
AB - The therapeutic efficacy of long-circulating polyethylene glycol-coated liposomal
amphotericin B (AMB) (PEG-AMB-LIP) was compared with that of AMB desoxycholate
(Fungizone) in a model of severe invasive pulmonary aspergillosis in persistently
leukopenic rats as well as in temporarily leukopenic rats. PEG-AMB-LIP treatment
(intravenous administration) consisted of a single, or double (every 72 h), or
triple (every 72 h) dose of 10 mg of AMB/kg of body weight, a double dose (every
72 h) of 14 mg of AMB/kg, or a 5-day treatment (every 24 h) with 6 mg/kg/dose.
AMB desoxycholate was administered for 10 consecutive days at 1 mg of
AMB/kg/dose. Treatment was started 30 h after fungal inoculation, at which time
mycelial growth was firmly established. Both persistently and temporarily
leukopenic rats died between 4 and 9 days after Aspergillus fumigatus inoculation
when they were left untreated or after treatment with a placebo. In persistently
leukopenic rats, a single dose of PEG-AMB-LIP (10 mg/kg) was as effective as the
10-day treatment with AMB desoxycholate (at 1 mg/kg/dose) in significantly
prolonging the survival of rats infected with A. fumigatus and in reducing the
dissemination of A. fumigatus to the liver. Prolongation of PEG-AMB-LIP treatment
(double or triple dose or 5-day treatment) did not further improve efficacy. For
temporarily leukopenic rats no major advances in efficacy were achieved compared
to those for persistently leukopenic rats, probably because the leukocyte numbers
in blood were restored too late in the course of infection.
PMID- 10681316
TI - A sensitive amphotericin B immunoassay for pharmacokinetic and distribution
studies.
AB - Since currently used assays of amphotericin B (AMB) lack sensitivity or are not
easily adaptable in all laboratories, we have developed an enzyme immunoassay for
AMB in biological fluids and tissues. Antibodies to AMB were raised in rabbits
after administration of an AMB-bovine serum albumin conjugate. The enzymatic
tracer was obtained by coupling AMB via its amino group to acetylcholinesterase
(EC 3.1.1.7). These reagents were used for the development of a competitive
immunoassay performed on microtitration plates. The limit of quantification was
100 pg/ml in plasma and 1 ng/g in tissues. The plasma assay was performed
directly without extraction on a minimal volume of 0.1 ml. The intra- and
interassay coefficients of variation were in the range of 5 to 17%, and the
recoveries were 92 to 111% for AMB added to human plasma. The assay was applied
to a pharmacokinetic study with mice given AMB intraperitoneally at the dose of 1
mg/kg. The drug distribution in selected compartments (plasma, liver, spleen,
lung, and brain) was monitored until 72 h after administration. In conclusion,
our assay is at least 100-fold more sensitive than previously described bioassays
or chromatographic determinations of AMB and may be useful in studying the tissue
pharmacokinetics of new AMB formulations and in drug monitoring in clinical
situations.
PMID- 10681317
TI - In vitro antihepadnaviral activities of combinations of penciclovir, lamivudine,
and adefovir.
AB - Penciclovir (9-[2-hydroxy-1-(hydroxymethyl)-ethoxymethyl]guanine [PCV]),
lamivudine ([-]-beta-L-2',3'-dideoxy-3'-thiacytidine [3TC]), and adefovir (9-[2
phosphonylmethoxyethyl]-adenine [PMEA]) are potent inhibitors of hepatitis B
virus (HBV) replication. Lamivudine has recently received approval for clinical
use against chronic human HBV infection, and both PCV and PMEA have undergone
clinical trials against HBV in their respective prodrug forms (famciclovir and
adefovir dipivoxil [bis-(POM)-PMEA]). Since multidrug combinations are likely to
be used to control HBV infection, investigation of potential interactions between
PCV, 3TC, and PMEA is important. Primary duck hepatocyte cultures which were
either acutely or congenitally infected with the duck hepatitis B virus (DHBV)
were used to investigate in vitro interactions between PCV, 3TC, and PMEA. Here
we show that the anti-DHBV effects of all the combinations containing PCV, 3TC,
and PMEA are greater than that of each of the individual components and that
their combined activities are approximately additive or synergistic. These
results may underestimate the potential in vivo usefulness of PMEA-containing
combinations, since there is evidence that PMEA has immunomodulatory activity
and, at least in the duck model of chronic HBV infection, is capable of
inhibiting DHBV replication in cells other than hepatocytes, the latter being
unaffected by treatment with either PCV or 3TC. Further investigation of the
antiviral activities of these drug combinations is therefore required,
particularly since each of the component drugs is already in clinical use.
PMID- 10681318
TI - ampR gene mutations that greatly increase class C beta-lactamase activity in
Enterobacter cloacae.
AB - The ampC and ampR genes of Enterobacter cloacae GN7471 were cloned into pMW218 to
yield pKU403. Four mutant plasmids derived from pKU403 (pKU404, pKU405, pKU406,
and pKU407) were isolated in an AmpD mutant of Escherichia coli ML4953 by
selection with ceftazidime or aztreonam. The beta-lactamase activities expressed
by pKU404, pKU405, pKU406, and pKU407 were about 450, 75, 160, and 160 times
higher, respectively, than that expressed by the original plasmid, pKU403. These
mutant plasmids all carried point mutations in the ampR gene. In pKU404 and
pKU405, Asp-135 was changed to Asn and Val, respectively. In both pKU406 and
pKU407, Arg-86 was changed to Cys. The ease of selection of AmpR mutations at a
frequency of about 10(-6) in this study strongly suggests that derepressed
strains, such as AmpD or AmpR mutants, could frequently emerge in the clinical
setting.
PMID- 10681319
TI - A novel human immunodeficiency virus type 1 reverse transcriptase mutational
pattern confers phenotypic lamivudine resistance in the absence of mutation 184V.
AB - We describe a new human immunodeficiency virus type 1 (HIV-1) mutational pattern
associated with phenotypic resistance to lamivudine (3TC) in the absence of the
characteristic replacement of methionine by valine at position 184 (M184V) of
reverse transcriptase. Combined genotypic and phenotypic analyses of clinical
isolates revealed the presence of moderate levels of phenotypic resistance
(between 4- and 50-fold) to 3TC in a subset of isolates that did not harbor the
M184V mutation. Mutational cluster analysis and comparison with the phenotypic
data revealed a significant correlation between moderate phenotypic 3TC
resistance and an increased incidence of replacement of glutamic acid by aspartic
acid or alanine and of valine by isoleucine at residues 44 and 118 of reverse
transcriptase, respectively. This occurred predominantly in those isolates
harboring zidovudine resistance-associated mutations (41L, 215Y). The requirement
of the combination of mutations 41L and 215Y with mutations 44D and 44A and/or
118I for phenotypic 3TC resistance was confirmed by site-directed mutagenesis
experiments. These data support the assumption that HIV-1 may have access to
several different genetic pathways to escape drug pressure or that the increase
in the frequency of particular mutations may affect susceptibility to drugs that
have never been part of a particular regimen.
PMID- 10681320
TI - Faropenem transport across the renal epithelial luminal membrane via inorganic
phosphate transporter Npt1.
AB - We previously showed that the mouse inorganic phosphate transporter Npt1 operates
in the hepatic sinusoidal membrane transport of anionic drugs such as
benzylpenicillin and mevalonic acid. In the present study, the mechanism of renal
secretion of penem antibiotics was examined by using a Xenopus oocyte expression
system. Faropenem (an oral penem antibiotic) was transported via Npt1 with a
Michaelis-Menten constant of 0.77 +/- 0.34 mM in a sodium-independent but
chloride ion-sensitive manner. When the concentration of chloride ions was
increased, the transport activity of faropenem by Npt1 was decreased. Since the
concentration gradient of chloride ions is in the lumen-to-intracellular
direction, faropenem is expected to be transported from inside proximal tubular
cells to the lumen. So, we tested the release of faropenem from Xenopus oocytes.
The rate of efflux of faropenem from Npt1-expressing oocytes was about 9.5 times
faster than that from control water-injected Xenopus oocytes. Faropenem transport
by Npt1 was significantly inhibited by beta-lactam antibiotics such as
benzylpenicillin, ampicillin, cephalexin, and cefazolin to 24.9, 40. 5, 54.4, and
26.2% of that for the control, respectively. Zwitterionic beta-lactam antibiotics
showed lesser inhibitory effects on faropenem uptake than anionic derivatives,
indicating that Npt1 preferentially transports anionic compounds. Other anionic
compounds, such as indomethacin and furosemide, and the anion transport inhibitor
4,4'-diisothiocyanostilbene-2,2'-disulfonic acid significantly inhibited
faropenem uptake mediated by Npt1. In conclusion, our results suggest that Npt1
participates in the renal secretion of penem antibiotics.
PMID- 10681321
TI - Pharmacokinetics and safety of ascending single doses of DZ-2640, a new oral
carbapenem antibiotic, administered to healthy Japanese subjects.
AB - DZ-2640 is the ester-type oral carbapenem prodrug of an active parent compound,
DU-6681. The pharmacokinetics and safety of DU-6681 were investigated in six
studies after oral administration of a single dose of DZ-2640 to healthy male
Japanese volunteers at doses of 25, 50, 100, 200, and 400 mg (as the equivalents
of DU-6681) in the fasted state. The same volunteers received the drug at a dose
of 100 mg in the fasted and fed states to examine the effect of food intake on
the bioavailability of DZ-2640. The concentrations of DU-6681 in plasma and urine
were determined by a validated high-performance liquid chromatography method and
a bioassay. A good correlation between both methods was seen, indicating an
absence of major active metabolites. The mean maximum concentrations of DU-6681
in plasma (C(max)) ranged from 0.263 microgram/ml (25-mg dose) to 2.489
microgram/ml (400-mg dose) and were reached within 1.5 h following drug
administration. After reaching the C(max), plasma DU-6681 concentrations declined
in a monophasic manner, with a half-life of 0.47 to 0.89 h. The area under the
concentration-time curve (AUC) and C(max) increased almost linearly with the dose
up to the 200-mg dose. The AUC and C(max) increased less than proportionally
after administration of the 400-mg dose, suggesting a reduction in drug
absorption. The plasma protein binding of DU-6681 was in the range of 23.3 to
25.6%. The cumulative urinary recoveries (0 to 24 h) were in the range of 31.9 to
44.9%. The AUC was slightly but statistically significantly reduced by food
intake. However, the C(max), half-life, and recovery in urine were not affected
by food intake. The renal clearance (402 to 510 ml/min) was much greater than the
mean glomerular filtration rate (ca. 120 ml/min), which indicated active tubular
secretion of the drug. A mild transient and moderate diarrhea was observed in two
of six volunteers in the study with a single dose of 25 mg. Mild soft stools were
observed in two of six volunteers who received a 400-mg dose of the drug.
PMID- 10681322
TI - Inactivation of the ampD gene in Pseudomonas aeruginosa leads to moderate-basal
level and hyperinducible AmpC beta-lactamase expression.
AB - It has been shown in enterobacteria that mutations in ampD provoke
hyperproduction of chromosomal beta-lactamase, which confers to these organisms
high levels of resistance to beta-lactam antibiotics. In this study, we
investigated whether this genetic locus was implicated in the altered AmpC beta
lactamase expression of selected clinical isolates and laboratory mutants of
Pseudomonas aeruginosa. The sequences of the ampD genes and promoter regions from
these strains were determined and compared to that of wild-type ampD from P.
aeruginosa PAO1. Although we identified numerous nucleotide substitutions, they
resulted in few amino acid changes. The phenotypes produced by these mutations
were ascertained by complementation analysis. The data revealed that the ampD
genes of the P. aeruginosa mutants transcomplemented Escherichia coli ampD
mutants to the same levels of beta-lactam resistance and beta-lactamase
expression as wild-type ampD. Furthermore, complementation of the P. aeruginosa
mutants with wild-type ampD did not restore the inducibility of beta-lactamase to
wild-type levels. This shows that the amino acid substitutions identified in AmpD
do not cause the altered phenotype of AmpC beta-lactamase expression in the P.
aeruginosa mutants. The effects of AmpD inactivation in P. aeruginosa PAO1 were
further investigated by gene replacement. This resulted in moderate-basal-level
and hyperinducible expression of beta-lactamase accompanied by high levels of
beta-lactam resistance. This differs from the stably derepressed phenotype
reported in AmpD-defective enterobacteria and suggests that further change at
another unknown genetic locus may be causing total derepressed AmpC production.
This genetic locus could also be altered in the P. aeruginosa mutants studied in
this work.
PMID- 10681323
TI - A dose ranging study of the pharmacokinetics, safety, and preliminary efficacy of
lamivudine in children and adolescents with chronic hepatitis B.
AB - Fifty-three patients with chronic hepatitis B and active viral replication were
studied for 4 weeks while on treatment and for 12 weeks after treatment with the
oral nucleoside analogue lamivudine. Children aged 2 to 12 years were randomized
to receive twice-daily doses of 0.35, 1.5, or 4 mg of lamivudine solution per kg
of body weight or once-daily doses of 3 mg of lamivudine solution per kg.
Adolescents aged 13 to 17 years received lamivudine at 100 mg (as tablets). Blood
samples for pharmacokinetic assay were taken on days 1 and 28. Lamivudine was
rapidly absorbed following oral administration, with the maximum concentration in
serum being reached 0.5 to 1 h postdosing. Apparent oral clearance (CL/F) was
higher in younger children and decreased with age, with CL/F values for
adolescents reaching those seen for adults by the age of 12. All doses produced a
dramatic fall in serum hepatitis B virus (HBV) DNA levels, with a median
reduction of >/=99.5% after 4 weeks of treatment and with the levels returning to
the baseline levels posttreatment. The correlation of dose, area under the
concentration-time curve (AUC), and changes in HBV DNA levels, as measured by the
Chiron Quantiplex assay, showed maximal antiviral effects (99.9% inhibition and a
reduction of the amount of HBV DNA of approximately 3 log(10)) at 3 mg/kg/day,
with no discernible increase in effect seen whether the drug was given at 4 mg/kg
twice daily or whether it was given once daily or twice daily. The limit of
detection of the assay (2.5 pg/ml) was reached for some but not all patients
across the dose ranges, with the smallest number (n = 2) of those having values
negative by the Chiron Quantiplex assay being in the lowest-dose group. The 13-
to 17-year-olds showed a similar overall response in terms of the HBV DNA level
reduction compared to that for patients younger than age 13. Analysis of the same
samples by PCR, which has a lower limit of sensitivity than the Chiron Quantiplex
assay, also showed average drops in HBV DNA levels of about 3 log(10) at 4 weeks
for patients for which the AUC was >/=4,000 ng. h/ml, confirming the conclusions
given above. Lamivudine treatment was well tolerated at all doses, with no
significant adverse events or laboratory data changes. On the basis of
pharmacokinetic and pharmacodynamic data, a 3-mg/kg/day dose in children (ages 2
to 12 years) with chronic hepatitis B provides levels of exposure and trough
concentrations similar to those seen in adults following the receipt of doses of
100 mg. The 100-mg dose is being evaluated in a large phase III study with HBV
infected pediatric patients.
PMID- 10681324
TI - Activities of trovafloxacin, gatifloxacin, clinafloxacin, sparfloxacin,
levofloxacin, and ciprofloxacin against penicillin-resistant Streptococcus
pneumoniae in an in vitro infection model.
AB - We adapted an in vitro pharmacodynamic model of infection to incorporate infected
fibrin clots. The bactericidal activities of various fluoroquinolones against two
strains of penicillin-resistant Streptococcus pneumoniae were studied over a 48-h
period. Bacteria were prepared in Muller-Hinton broth by using colonies from a 24
h tryptic soy agar plus 5% sheep blood plate and were added to a mixture of
cryoprecipitate (80%) and thrombin (10%) to achieve approximately 10(6) CFU of
organism per fibrin clot. The fibrin clots were suspended into the models and
removed, in triplicate, at various time points over 48 h. Control models were
also conducted to characterize the growth of S. pneumoniae in the growth medium
without antibiotic. Trovafloxacin, gatifloxacin, clinafloxacin, sparfloxacin,
levofloxacin, and ciprofloxacin were administered to simulate their
pharmacokinetic profiles in humans. Fibrin clot samples were also plated onto
antibiotic-containing tryptic soy agar plus 5% lysed horse blood to detect
resistance. The newer fluoroquinolones demonstrated better activity than
ciprofloxacin against both isolates. In conclusion, the newer quinolones
demonstrated significant activity against penicillin-resistant S. pneumoniae,
with standard dosing resulting in area under the concentration-time curve/MIC
ratios and peak concentration/MIC ratios that resulted in 99.9% killing against
these isolates.
PMID- 10681325
TI - Antibacterial and antimembrane activities of cecropin A in Escherichia coli.
AB - The ability of cecropin A to permeabilize and depolarize the membranes of
Escherichia coli ML-35p bacteria has been compared to its bactericidal activity
in an extension of earlier studies performed on synthetic lipid vesicle membranes
(L. Silvestro, K. Gupta, J. H. Weiser, and P. H. Axelsen, Biochemistry 36:11452
11460, 1997). Our results indicate that differences in the concentration
dependences of membrane permeabilization and depolarization seen in synthetic
vesicles are not manifested in whole bacteria. The concentration dependences of
both phenomena roughly correlate with bactericidal activity, suggesting that the
bactericidal mechanism of cecropin A is related to membrane permeabilization.
PMID- 10681326
TI - Frequent association between alteration of the rdxA gene and metronidazole
resistance in French and North African isolates of Helicobacter pylori.
AB - Mutations in the rdxA gene have been associated with the acquisition of
resistance to metronidazole in Helicobacter pylori. This gene encodes an NADPH
nitroreductase whose expression is necessary for intracellular activation of the
drug. We wished to examine whether mutations in rdxA were present in resistant H.
pylori isolates infecting either French or North African patients. We determined
the complete nucleotide sequences of the rdxA genes from seven French and six
North African patients infected with paired resistant and sensitive strains.
Genotyping by random amplified polymorphic DNA analysis confirmed the close
genetic relatedness of the susceptible and resistant isolates from individual
biopsies. Eight French and five North African individual resistant strains were
also studied. For the French strains, an alteration in rdxA most probably
implicated in resistance was found in 10 cases (seven frameshift mutations, two
missense mutations, and one deletion of 211 bp). One to three putative missense
mutations were identified in four cases, and a missense mutation possibly not
implicated in resistance was discovered in the last case. For the North African
strains, an alteration in rdxA was found in eight cases (three frameshift
mutations, three missense mutations, one deletion of 6 bp, and one insertion of a
variant of IS605). Two strains contained putative missense mutations, and no
change was observed in rdxA of the last strain. Thus, inactivation of the rdxA
gene is frequently, but not always, associated with resistance to metronidazole
in French and North African clinical isolates of H. pylori. In addition, a
variety of alterations of rdxA are associated with the resistant phenotype.
PMID- 10681327
TI - Efficacy of FK463, a new lipopeptide antifungal agent, in mouse models of
disseminated candidiasis and aspergillosis.
AB - The efficacy of intravenous injection of FK463, a novel water-soluble
lipopeptide, was evaluated in mouse models of disseminated candidiasis and
aspergillosis and was compared with those of fluconazole (FLCZ) and amphotericin
B (AMPH-B). In the candidiasis model, FK463 significantly prolonged the survival
of intravenously infected mice at doses of 0.125 mg/kg of body weight or higher.
In disseminated candidiasis caused by Candida species, including FLCZ-resistant
Candida albicans, FK463 exhibited an efficacy 1.4 to 18 times inferior to that of
AMPH-B, with 50% effective doses (ED(50)s) ranging from 0.21 to 1.00 mg/kg and
0.06 to 0.26 mg/kg, respectively, and was much more active than FLCZ. The
protective effect of FK463 was not obviously influenced by the fungal inoculum
size, the starting time of the treatment, or the immunosuppressed status of the
host. The reduction in efficacy was less than that observed with FLCZ or AMPH-B.
The efficacy of FK463 was also evaluated in the disseminated candidiasis target
organ assay and was compared with those of FLCZ and AMPH-B. Efficacies were
evaluated on the basis of a comparison between the mean log(10) CFU in kidneys in
the groups treated with antifungal agents and that in control group. A single
dose of FK463 at 0.5 mg/kg or higher significantly reduced the viable counts in
kidneys compared with the numbers of yeast cells before treatment, and its
efficacy was comparable to that of AMPH-B, while FLCZ at 4 mg/kg showed only a
suppressive effect on the growth of C. albicans in the kidneys. In the
disseminated aspergillosis model, FK463 given at doses of 0.5 mg/kg or higher
significantly prolonged the survival of mice infected intravenously with
Aspergillus fumigatus conidia. The efficacy of FK463 was about 2 times inferior
to that of AMPH-B, with ED(50)s ranging from 0.25 to 0.50 mg/kg and 0.11 to 0.29
mg/kg, respectively. These results indicate that FK463 may be a potent
parenterally administered therapeutic agent for disseminated candidiasis and
aspergillosis.
PMID- 10681328
TI - Efficacy of FK463, a new lipopeptide antifungal agent, in mouse models of
pulmonary aspergillosis.
AB - The efficacy of FK463, a novel water-soluble lipopeptide, was evaluated in mouse
models of pulmonary aspergillosis and was compared with that of amphotericin B
(AMPH-B). In the pulmonary aspergillosis models induced by intranasal
inoculation, FK463 exhibited good efficacy, with 50% effective doses in the range
of 0. 26 to 0.51 mg/kg of body weight; these values were comparable to those of
AMPH-B. In an Aspergillus target organ assay with immunosuppressed mice, under
conditions of constant plasma levels of FK463, using a subcutaneously implanted
osmotic pressure pump, a significant reduction in viable fungal cells was
observed at plasma FK463 levels of 0.55 to 0.80 microgram/ml or higher. We
conclude that FK463 is highly effective in the treatment of pulmonary
aspergillosis in this animal model. These results indicate that FK463 may be a
potent parenterally administered antifungal agent for pulmonary aspergillosis.
PMID- 10681329
TI - Biochemical sequence analyses of GES-1, a novel class A extended-spectrum beta
lactamase, and the class 1 integron In52 from Klebsiella pneumoniae.
AB - Klebsiella pneumoniae ORI-1 was isolated in 1998 in France from a rectal swab of
a 1-month-old girl who was previously hospitalized in Cayenne Hospital, Cayenne,
French Guiana. This strain harbored a ca. 140-kb nontransferable plasmid, pTK1,
that conferred an extended-spectrum cephalosporin resistance profile antagonized
by the addition of clavulanic acid, tazobactam, or imipenem. The gene for GES-1
(Guiana extended-spectrum beta-lactamase) was cloned, and its protein was
expressed in Escherichia coli DH10B, where this pI-5. 8 beta-lactamase of a ca.
31-kDa molecular mass conferred resistance to oxyimino cephalosporins (mostly to
ceftazidime). GES-1 is weakly related to the other plasmid-located Ambler class A
extended-spectrum beta-lactamases (ESBLs). The highest percentage of amino acid
identity was obtained with the carbenicillinase GN79 from Proteus mirabilis; with
YENT, a chromosome-borne penicillinase from Yersinia enterocolitica; and with L
2, a chromosome-borne class A cephalosporinase from Stenotrophomonas maltophilia
(36% amino acid identity each). However, a dendrogram analysis showed that GES-1
clustered within a class A ESBL subgroup together with ESBLs VEB-1 and PER-1.
Sequencing of a 7,098-bp DNA fragment from plasmid pTK1 revealed that the GES-1
gene was located on a novel class 1 integron named In52 that was characterized by
(i) a 5' conserved segment containing an intI1 gene possessing two putative
promoters, P(1) and P(2), for coordinated expression of the downstream antibiotic
resistance genes and an attI1 recombination site; (ii) five antibiotic gene
cassettes, bla(GES-1), aac(6')Ib' (gentamicin resistance and amikacin
susceptibility), dfrXVb (trimethoprim resistance), a novel chloramphenicol
resistance gene (cmlA4), and aadA2 (streptomycin-spectinomycin resistance); and
(iii) a 3' conserved segment consisting of qacEDelta1 and sulI. The bla(GES-1)
and aadA2 gene cassettes were peculiar, since they lacked a typical 59-base
element. This work identified the second class A ESBL gene of a non-TEM, non-SHV
series which was located in the plasmid and integron, thus providing it
additional means for its spread and its expression.
PMID- 10681330
TI - Activities and postantibiotic effects of gemifloxacin compared to those of 11
other agents against Haemophilus influenzae and Moraxella catarrhalis.
AB - The activity of gemifloxacin against Haemophilus influenzae and Moraxella
catarrhalis was compared to those of 11 other agents. All quinolones were very
active (MICs, =0.125 microgram/ml) against 248 quinolone-susceptible H.
influenzae isolates (40.7% of which were beta-lactamase positive); cefixime
(MICs, =0.125 microgram/ml) and amoxicillin-clavulanate (MICs =4.0
microgram/ml) were active, followed by cefuroxime (MICs, =16.0 microgram/ml);
azithromycin MICs were =4.0 microg/ml. For nine H. influenzae isolates with
reduced quinolone susceptibilities, the MICs at which 50% of isolates are
inhibited (MIC(50)s) were 0.25 microgram/ml for gemifloxacin and 1.0 microgram/ml
for the other quinolones tested. All strains had mutations in GyrA (Ser84,
Asp88); most also had mutations in ParC (Asp83, Ser84, Glu88) and ParE (Asp420,
Ser458), and only one had a mutation in GyrB (Gln468). All quinolones tested were
equally active (MICs, =0.06 microgram/ml) against 50 M. catarrhalis strains;
amoxicillin-clavulanate, cefixime, cefuroxime, and azithromycin were very active.
Against 10 H. influenzae strains gemifloxacin, levofloxacin, sparfloxacin, and
trovafloxacin at 2x the MIC and ciprofloxacin at 4x the MIC were uniformly
bactericidal after 24 h, and against 9 of 10 strains grepafloxacin at 2x the MIC
was bactericidal after 24 h. After 24 h bactericidal activity was seen with
amoxicillin-clavulanate at 2x the MIC for all strains, cefixime at 2x the MIC for
9 of 10 strains, cefuroxime at 4x the MIC for all strains, and azithromycin at 2x
the MIC for all strains. All quinolones except grepafloxacin (which was
bactericidal against four of five strains) and all ss-lactams at 2x to 4x the MIC
were bactericidal against five M. catarrhalis strains after 24 h; azithromycin at
the MIC was bactericidal against all strains after 24 h. The postantibiotic
effects (PAEs) against four quinolone-susceptible H. influenzae strains were as
follows: gemifloxacin, 0.3 to 2.3 h; ciprofloxacin, 1.3 to 4.2 h; levofloxacin,
2.8 to 6.2 h; sparfloxacin, 0.6 to 3.0 h; grepafloxacin, 0 to 2.1 h;
trovafloxacin, 0.8 to 2.8 h. At 10x the MIC, no quinolone PAEs were found against
the strain for which quinolone MICs were increased. Azithromycin PAEs were 3.7 to
7.3 h.
PMID- 10681331
TI - A dose-response study of antibiotic resistance in Pseudomonas aeruginosa
biofilms.
AB - Bacterial biofilms show enormous levels of antibiotic resistance, but little is
known about the underlying molecular mechanisms. Multidrug resistance pumps
(MDRs) are responsible for the extrusion of chemically unrelated antimicrobials
from the bacterial cell. Contribution of the MDR-mediated efflux to antibiotic
resistance of Pseudomonas aeruginosa biofilms was examined by using strains
overexpressing and lacking the MexAB-OprM pump. Resistance of P. aeruginosa
biofilms to ofloxacin was dependent on the expression of MexAB-OprM but only in
the low concentration range. Unexpectedly, biofilm resistance to ciprofloxacin,
another substrate of MexAB-OprM, did not depend on the presence of this pump.
Dose-dependent killing indicated the presence of a small "superresistant" cell
fraction. This fraction was primarily responsible for very high resistance of P.
aeruginosa biofilms to quinolones. Bacterial cells recovered from a biofilm and
tested under nongrowing conditions with tobramycin exhibited higher resistance
levels than planktonic cells but lower levels than cells of an intact biofilm.
PMID- 10681332
TI - Characterization of the fomA and fomB gene products from Streptomyces
wedmorensis, which confer fosfomycin resistance on Escherichia coli.
AB - Together, the fomA and fomB genes in the fosfomycin biosynthetic gene cluster of
Streptomyces wedmorensis confer high-level fosfomycin resistance on Escherichia
coli. To elucidate their functions, the fomA and fomB genes were overexpressed in
E. coli and the gene products were characterized. The recombinant FomA protein
converted fosfomycin to fosfomycin monophosphate, which was inactive on E. coli,
in the presence of a magnesium ion and ATP. On the other hand, the recombinant
FomB protein did not inactivate fosfomycin. However, a reaction mixture
containing FomA and FomB proteins converted fosfomycin to fosfomycin
monophosphate and fosfomycin diphosphate in the presence of ATP and a magnesium
ion, indicating that FomA and FomB catalyzed phosphorylations of fosfomycin and
fosfomycin monophosphate, respectively. These results suggest that the self
resistance mechanism of the fosfomycin-producing organism S. wedmorensis is mono-
and diphosphorylation of the phosphonate function of fosfomycin catalyzed by FomA
and FomB.
PMID- 10681333
TI - Inhibition of inositol phosphorylceramide synthase by aureobasidin A in Candida
and Aspergillus species.
AB - Inositol phosphorylceramide (IPC) synthase is an enzyme common to fungi and
plants that catalyzes the transfer of phosphoinositol from phosphatidylinositol
to ceramide to form IPC. The reaction is a key step in fungal sphingolipid
biosynthesis and the target of the antibiotics galbonolide A, aureobasidin A, and
khafrefungin. As a first step toward understanding the antifungal spectrum of IPC
synthase inhibitors, we examined the sensitivity of IPC synthase to aureobasidin
A in membrane preparations of Candida species (Candida albicans, C. glabrata, C.
tropicalis, C. parapsilosis, and C. krusei) and Aspergillus species (Aspergillus
fumigatus, A. flavus, A. niger, and A. terreus). As expected, preparations from
the five Candida species, all exquisitely susceptible to aureobasidin A (MICs, <2
microgram/ml), had IPC synthase activity (specific activity, 50 to 400
pmol/min/mg of protein) sensitive to aureobasidin A (50% inhibitory
concentrations [IC(50)s], 2 to 4 ng/ml). Surprisingly, preparations from the four
Aspergillus species, including A. fumigatus and A. flavus, which are
intrinsically resistant to aureobasidin A (MICs, >50 microgram/ml), had IPC
synthase activity (specific activity, 1 to 3 pmol/min/mg of protein) also
sensitive to aureobasidin A (IC(50)s, 3 to 5 ng/ml). The mammalian multidrug
resistance modulators verapamil, chlorpromazine, and trifluoperazine lowered the
MIC of aureobasidin A for A. fumigatus from >50 microgram/ml to 2 to 3
microgram/ml, suggesting that the resistance of this major fungal pathogen is the
result of increased efflux.
PMID- 10681334
TI - Efficacy of linezolid in experimental otitis media.
AB - Therapy for otitis media (OM) due to resistant Streptococcus pneumoniae (MIC of
penicillin, >/=2.0 microgram/ml) is challenging. Linezolid, an oxazolidinone,
represent a new class of antimicrobial agents with excellent in vitro activity
against penicillin-resistant S. pneumoniae; however, in vitro activity against
nontypeable Haemophilus influenzae (NTHI) is limited. We evaluated its efficacy
against experimental acute OM due to a multidrug-resistant S. pneumoniae isolate
and two isolates of NTHI. The chinchilla model was utilized to evaluate the
efficacy of linezolid against experimental infection due to S. pneumoniae or
NTHI. Serum and middle ear antibiotic concentrations were determined, and
sterilization of experimental OM was evaluated. Chinchillas were inoculated
directly with S. pneumoniae into the superior bulla. Twenty-four hours after
inoculation, all animals had positive middle ear and nasopharyngeal cultures.
Animals were given linezolid at 25 mg/kg/dose twice a day (b.i.d.) by orogastric
feeding tube or amoxicillin at 40 mg/kg/dose b.i.d. intramuscularly for 5 days.
By day 5, all animals in the linezolid group had sterile middle ear cultures and
eradication of S. pneumoniae from the nasopharynx. In the amoxicillin group, all
nine animals remained middle ear and nasopharynx positive (P < 0.01). In animals
inoculated with NTHI, 25 and 37.5 mg/kg b.i.d. failed to sterilize middle ear
infection or eradicate colonization. Mean levels in middle ear fluid measured
during experimental infection were 12.8 microgram/ml at 2 to 6 h and 4. 1
mirogram/ml at 16 to 17 h after orogastric dosing at 25 mg/kg. Linezolid achieved
a high concentration in the middle ear during experimental OM. Linezolid
eradicated multidrug-resistant S. pneumoniae from the middle ear and nasopharynx.
Experimental infection and nasopharyngeal colonization due to NTHI persisted
despite achievement of concentrations in the middle ear that were above the MIC
(for NTHI).
PMID- 10681335
TI - Assignment of the substrate-selective subunits of the MexEF-OprN multidrug efflux
pump of Pseudomonas aeruginosa.
AB - Pseudomonas aeruginosa expresses a low level of the MexAB-OprM efflux pump and
shows natural resistance to many structurally and functionally diverse
antibiotics. The mutation that has been referred to previously as nfxC expresses
an additional efflux pump, MexEF-OprN, exhibiting resistance to fluoroquinolones,
imipenem, and chloramphenicol and hypersusceptibility to beta-lactam antibiotics.
To address the antibiotic specificity of the MexEF-OprN efflux pump, we
introduced a plasmid carrying the mexEF-oprN operon into P. aeruginosa lacking
the mexAB-oprM operon. The transformants exhibited resistance to
fluoroquinolones, trimethoprim, and chloramphenicol but, unlike most nfxC-type
mutants, did not show beta-lactam hypersusceptibility. The transformants
exhibited additional resistance to tetracycline. In the next experiment, we
analyzed the MexEF-OprN pump subunit(s) responsible for substrate selectivity by
expressing MexE, MexF, OprN, and MexEF in strains lacking MexA, MexB, OprM, and
MexAB, respectively. The MexEF-OprM/DeltaMexAB transformants exhibited MexEF-OprN
type pump function that rendered the strains resistant to fluoroquinolones and
chloramphenicol but did not change susceptibility to beta-lactam antibiotics
compared with the host strain. The MexAB-OprN/DeltaOprM, MexAF-OprM/DeltaMexB,
and MexEB-OprM/DeltaMexA mutants exhibited antibiotic susceptibility
indistinguishable from that in the mutant lacking both types of efflux pumps. The
results imply that the MexEF-OprM pump selects substrates by a MexEF functional
unit. Interestingly, OprN did not link functionally with the MexAB complex,
despite the fact that OprM interacted functionally with MexEF.
PMID- 10681336
TI - Apoptosis in renal proximal tubules of rats treated with low doses of
aminoglycosides.
AB - Kidney cortex apoptosis was studied with female Wistar rats treated for 10 days
with gentamicin and netilmicin at daily doses of 10 or 20 mg/kg of body weight
and amikacin or isepamicin at daily doses of 40 mg/kg. Apoptosis was detected and
quantitated using cytological (methyl green-pyronine) and immunohistochemical
(terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling)
staining, in parallel with a measurement of drug-induced phospholipidosis
(cortical phospholipids and phospholipiduria), cortical proliferative response
((3)H incorporation in DNA and histoautoradiography after in vivo pulse-labeling
with [(3)H]thymidine), and kidney dysfunction (blood urea nitrogen and
creatinine). Gentamicin induced in proximal tubules a marked apoptotic reaction
which (i) was detectable after 4 days of treatment but was most conspicuous after
10 days, (ii) was dose dependent, (iii) occurred in the absence of necrosis, and
(iv) was nonlinearly correlated with the proliferative response (tubular and
peritubular cells). Comparative studies revealed a parallelism among the extents
of phospholipidosis, apoptosis, and proliferative response for three
aminoglycosides (gentamicin >> amikacin congruent with isepamicin). By contrast,
netilmicin induced a marked phospholipidosis but a moderate apoptosis and
proliferative response. We conclude that rats treated with gentamicin develop an
apoptotic process as part of the various cortical alterations induced by this
antibiotic at low doses. Netilmicin, and still more amikacin and isepamicin,
appears safer in this respect. Whereas a relation between aminoglycoside-induced
tubular apoptosis and cortical proliferative response seems to be established, no
simple correlation with phospholipidosis can be drawn.
PMID- 10681337
TI - Flow cytometric monitoring of antibiotic-induced injury in Escherichia coli using
cell-impermeant fluorescent probes.
AB - Three fluorescent nucleic acid binding dyes-propidium iodide, TO-PRO-1, and SYTOX
green-were evaluated, and their abilities to distinguish between bacterial cells
with and without an intact cytoplasmic membrane were compared. Each dye was
readily able to discriminate between healthy and permeabilized cells of
Escherichia coli, although SYTOX green showed a greater enhancement in
fluorescence intensity on staining-compromised, as opposed to healthy, cells in
log-phase growth, than either PI or TO-PRO-1. Flow cytometric analysis of E. coli
stained with these dyes after exposing them to several antimicrobial agents
showed that all three dyes were able to detect antimicrobial action. Notably,
however, the intensity of the cell-associated fluorescence was related to the
mechanism of action of the antimicrobial agent. Large changes in fluorescence
intensity were observed for all the dyes subsequent to beta-lactam antibiotic
action, but smaller changes (or no change) were seen subsequent to exposure to
antimicrobials acting directly or indirectly on nucleic acid synthesis.
Furthermore, cell-associated fluorescence did not relate to loss of viability as
determined by plate counts. Despite offering much insight into antimicrobial
mechanisms of action, these fundamental problems become relevant to the
development of rapid antimicrobial susceptibility tests if colony formation is
used as the standard.
PMID- 10681338
TI - Flow cytometric investigation of filamentation, membrane patency, and membrane
potential in Escherichia coli following ciprofloxacin exposure.
AB - Ninety-eight percent of the cells in a population of Escherichia coli in log
phase growth lost colony-forming ability after being exposed for 3 h to the
quinolone antibiotic ciprofloxacin at four times the MIC in nutrient broth, a
concentration easily reached in vivo. Flow cytometric analysis, however,
demonstrated that only 68% of this bacterial population had lost membrane
potential, as judged by the membrane potential-sensitive dye bis-(1,3
dibutylbarbituric acid) trimethine oxonol [DiBAC(4)(3)], and only 30% could no
longer exclude the nucleic acid-binding dye propidium iodide (PI), reflecting
lost membrane integrity, efflux mechanisms, or both. Subsequent removal of
ciprofloxacin and resuspension in nutrient broth resulted in renewed cell
division after 2 h, with a calculated postantibiotic effect (PAE) time of 57 min.
The proportion of DiBAC- and PI-fluorescent cells in this recovering population
remained stable for more than 4 h after antibiotic removal. Eighty percent of
cells present at drug removal were filamentous. Their number subsequently
decreased with time, and the increase in particle count seen at the end of the
PAE resulted from the division of short cells. Exposure to ciprofloxacin in the
presence of the protein synthesis inhibitor chloramphenicol increased colony
forming ability to 60% of starting population numbers. In contrast to
ciprofloxacin alone, this antibiotic combination resulted in insignificant
filamentation and no dye uptake. Subsequent drug removal and resuspension in
nutrient broth resulted in the appearance of filaments within 1 h, with 69% of
the population forming filaments at 3 h. Dye uptake was also seen, with 20% of
the population fluorescing with either dye after 4 h. We were unable to relate
dye uptake to the viable count. Cell division resumed 240 min after removal of
both drugs, yielding a PAE calculated at 186 min. Inhibition of protein synthesis
with chloramphenicol prevented ciprofloxacin-induced changes in bacterial
morphology, cell membrane potential, and ability to exclude nucleic acid-binding
dye. These changes persisted beyond the end of the classically defined PAE and
were not a definite indicator of cell death as defined by loss of colony
formation, which related at least in part to filamentation.
PMID- 10681339
TI - A standardized plaque reduction assay for determination of drug susceptibilities
of cytomegalovirus clinical isolates.
AB - Twelve laboratories collaborated in formulating and testing a standardized plaque
reduction assay for cytomegalovirus (CMV) cell-associated clinical isolates. Four
characterized and plaque-purified CMV strains, as well as six coded clinical
isolates obtained after antiviral therapy, were distributed and tested. Good
agreement was obtained for four of the clinical isolates, but a broad
distribution of results was obtained for two isolates. Analysis of these results
indicates the problems associated with clinical isolates, including the large
genetic variability and the highly cell-associated phenotype. This collaborative
effort, by addressing these problems, represents a significant step toward the
development of a standardized assay.
PMID- 10681340
TI - A double-blind placebo-controlled study of an infusion of lexipafant (Platelet
activating factor receptor antagonist) in patients with severe sepsis.
AB - Platelet-activating factor (PAF) is a potent endogenous proinflammatory mediator
implicated in the pathogenesis of septic shock. A double-blind randomized placebo
controlled trial of an intravenous PAF receptor antagonist (lexipafant) was
conducted with 131 adult Thai patients with suspected severe sepsis (66 of whom
had positive blood cultures). Detailed serial clinical, biochemical, and cytokine
measurements were performed. Lexipafant treatment was well tolerated. The 28-day
mortality in the lexipafant group (61.4%) was similar to that in the placebo
group (62.6%). There was also no evidence that lexipafant affected clinical or
biochemical measures of disease severity or the profile of sequentially measured
plasma cytokine levels. PAF may not have an important role in the pathogenesis of
severe sepsis.
PMID- 10681341
TI - Pharmacokinetics and pharmacodynamics of lumefantrine (benflumetol) in acute
falciparum malaria.
AB - The objective of this study was to conduct a prospective population
pharmacokinetic and pharmacodynamic evaluation of lumefantrine during blinded
comparisons of artemether-lumefantrine treatment regimens in uncomplicated
multidrug-resistant falciparum malaria. Three combination regimens containing an
average adult lumefantrine dose of 1,920 mg over 3 days (four doses) (regimen A)
or 2,780 mg over 3 or 5 days (six doses) (regimen B or C, respectively) were
given to 266 Thai patients. Detailed observations were obtained for 51
hospitalized adults, and sparse data were collected for 215 patients of all ages
in a community setting. The population absorption half-life of lumefantrine was
4.5 h. The model-based median (5th and 95th percentiles) peak plasma lumefantrine
concentrations were 6.2 (0.25 and 14.8) microgram/ml after regimen A, 9. 0 (1.1
and 19.8) microgram/ml after regimen B, and 8 (1.4 and 17.4) microgram/ml after
regimen C. During acute malaria, there was marked variability in the fraction of
drug absorbed by patients (coefficient of variation, 150%). The fraction
increased considerably and variability fell with clinical recovery, largely
because food intake was resumed; taking a normal meal close to drug
administration increased oral bioavailability by 108% (90% confidence interval,
64 to 164) (P, 0.0001). The higher-dose regimens (B and C) gave 60 and 100%
higher areas under the concentration-time curves (AUC), respectively, and thus
longer durations for which plasma lumefantrine concentrations exceeded the
putative in vivo MIC of 280 microgram/ml (median for regimen B, 252 h; that for
regimen C, 298 h; that for regimen A, 204 h [P, 0.0001]) and higher cure rates.
Lumefantrine oral bioavailability is very dependent on food and is consequently
poor in acute malaria but improves markedly with recovery. The high cure rates
with the two six-dose regimens resulted from increased AUC and increased time at
which lumefantrine concentrations were above the in vivo MIC.
PMID- 10681342
TI - The biopesticide Paenibacillus popilliae has a vancomycin resistance gene cluster
homologous to the enterococcal VanA vancomycin resistance gene cluster.
AB - We have previously identified, in Paenibacillus popilliae, a 708-bp sequence
which has homology to the sequence of the enterococcal vanA gene. We have
performed further studies revealing five genes encoding homologues of VanY, VanZ,
VanH, VanA, and VanX in P. popilliae. The predicted amino acid sequences are
similar to those in VanA vancomycin-resistant enterococci: 61% identity for VanY,
21% for VanZ, 74% for VanH, 77% for VanA, and 79% for VanX. The genes in P.
popilliae may have been a precursor to or have had ancestral genes in common with
vancomycin resistance genes in enterococci. The use of P. popilliae biopesticidal
preparations in agricultural practice may have an impact on bacterial resistance
in human pathogens.
PMID- 10681343
TI - Molecular mechanisms of fluoroquinolone resistance in Pseudomonas aeruginosa
isolates from cystic fibrosis patients.
AB - Twenty P. aeruginosa isolates were collected from six cystic fibrosis (CF)
patients, aged 27 to 33, in 1994 (9 isolates) and 1997 (11 isolates) at the CF
Center, Copenhagen, Denmark, and were typed by pulse-field gel electrophoresis
(PFGE) or ribotyping. Five of the patients had isolates with the same PFGE or
ribotyping patterns in 1997 as in 1994, and ciprofloxacin had a two- to fourfold
higher MIC for the isolates collected in 1997 than those from 1994. Genomic DNA
was amplified for gyrA, parC, mexR, and nfxB by PCR and sequenced. Eleven
isolates had mutations in gyrA, seven isolates had mutations at codon 83 (Thr to
Ile), and four isolates had mutations at codon 87 (Asp to Asn or Tyr). Sixteen
isolates had mutations in nfxB at codon 82 (Arg to Leu). Increased amounts of
OprN were found in six isolates and OprJ in eight isolates as determined by
immunoblotting. No isolates had mutations in parC or mexR. Six isolates had
mutations in efflux pumps without gyrA mutations. The average number of mutations
was higher in isolates from 1997 than in those from 1994. The results also
suggested that efflux resistance mechanisms are more common in isolates from CF
patients than in strains from urine and wounds from non-CF patients, in which
mutations in gyrA and parC dominate (S. Jalal and B. Wretlind, Microb. Drug
Resist. 4:257-261, 1998).
PMID- 10681344
TI - Effects of atovaquone and diospyrin-based drugs on the cellular ATP of
Pneumocystis carinii f. sp. carinii.
AB - Atovaquone (also called Mepron, or 566C80) is a napthoquinone used for the
treatment of infections caused by pathogens such as Plasmodium spp. and
Pneumocystis carinii. The mechanism of action against the malarial parasite is
the inhibition of dihydroorotate dehydrogenase (DHOD), a consequence of blocking
electron transport by the drug. As an analog of ubiquinone (coenzyme Q [CoQ]),
atovaquone irreversibly binds to the mitochondrial cytochrome bc(1) complex;
thus, electrons are not able to pass from dehydrogenase enzymes via CoQ to
cytochrome c. Since DHOD is a critical enzyme in pyrimidine biosynthesis, and
because the parasite cannot scavenge host pyrimidines, the drug is lethal to the
organism. Oxygen consumption in P. carinii is inhibited by the drug; thus,
electron transport has also been identified as the drug target in P. carinii.
However, unlike Plasmodium DHOD, P. carinii DHOD is inhibited only at high
atovaquone concentrations, suggesting that the organism may salvage host
pyrimidines and that atovaquone exerts its primary effects on ATP biosynthesis.
In the present study, the effect of atovaquone on ATP levels in P. carinii was
measured directly from 1 to 6 h and then after 24, 48, and 72 h of exposure. The
average 50% inhibitory concentration after 24 to 72 h of exposure was 1.5
microgram/ml (4.2 microM). The kinetics of ATP depletion were in contrast to
those of another family of naphthoquinone compounds, diospyrin and two of its
derivatives. Whereas atovaquone reduced ATP levels within 1 h of exposure, the
diospyrins required at least 48 h. After 72 h, the diospyrins were able to
decrease ATP levels of P. carinii at nanomolar concentrations. These data
indicate that although naphthoquinones inhibit the electron transport chain, the
molecular targets in a given organism are likely to be distinct among members of
this class of compounds.
PMID- 10681345
TI - Enzymes catalyzing the early steps of clavulanic acid biosynthesis are encoded by
two sets of paralogous genes in Streptomyces clavuligerus.
AB - Genes encoding the proteins required for clavulanic acid biosynthesis and for
cephamycin biosynthesis are grouped into a "supercluster" in Streptomyces
clavuligerus. Nine open reading frames (ORFs) associated with clavulanic acid
biosynthesis were located in a 15-kb segment of the supercluster, including six
ORFs encoding known biosynthetic enzymes or regulatory proteins, two ORFs that
have been reported previously but whose involvement in clavulanic acid
biosynthesis is unclear, and one ORF not previously reported. Evidence for the
involvement of these ORFs in clavulanic acid production was obtained by
generating mutants and showing that all were defective for clavulanic acid
production when grown on starch asparagine medium. However, when five of the nine
mutants, including mutants defective in known clavulanic acid biosynthetic
enzymes, were grown in a soy-based medium, clavulanic acid-producing ability was
restored. This ability to produce clavulanic acid when seemingly essential
biosynthetic enzymes have been mutated suggests that paralogous genes encoding
functionally equivalent proteins exist for each of the five genes but that these
paralogues are expressed only in the soy-based medium. The five genes that have
paralogues encode proteins involved in the early steps of the pathway common to
the biosynthesis of both clavulanic acid and the other clavam metabolites
produced by this organism. No evidence was seen for paralogues of the four
remaining genes involved in late, clavulanic acid-specific steps in the pathway.
PMID- 10681346
TI - Pharmacokinetics of SCH 56592, a new azole broad-spectrum antifungal agent, in
mice, rats, rabbits, dogs, and cynomolgus monkeys.
AB - SCH 56592 is a new broad-spectrum azole antifungal agent that is in phase 3
clinical trials for the treatment of serious systemic fungal infections. The
pharmacokinetics of this drug candidate were evaluated following its intravenous
(i.v.) or oral (p.o.) administration as a solution in hydroxypropyl-beta
cyclodextrin (HPbetaCD) or oral administration as a suspension in 0.4%
methylcellulose (MC) in studies involving mice, rats, rabbits, dogs, and
cynomolgus monkeys. SCH 56592 was orally bioavailable in all species. The oral
bioavailability was higher with the HPbetaCD solution (range, 52 to approximately
100%) than from the MC suspension (range, 14 to 48%) and was higher in mice (
approximately 100% [HPbetaCD] and 47% [MC]), rats ( approximately 66% [HPbetaCD]
and 48% [MC]), and dogs (72% [HPbetaCD] and 37% [MC]) than in monkeys (52%
[HPbetaCD] and 14% [MC]). In rabbits, high concentrations in serum suggested good
oral bioavailability with the MC suspension. The i.v. terminal-phase half-lives
were 7 h in mice and rats, 15 h in dogs, and 23 h in monkeys. In rabbits, the
oral half-life was 9 h. In species given increasing oral doses (mice, rats, and
dogs), serum drug concentrations were dose related. Food produced a fourfold
increase in serum drug concentrations in dogs. Multiple daily doses of 40 mg of
SCH 56592/kg of body weight for eight consecutive days to fed dogs resulted in
higher concentrations in serum, indicating accumulation upon multiple dosing,
with an accumulation index of approximately 2.6. Concentrations above the MICs
and minimum fungicidal concentrations for most organisms were observed at 24 h
following a single oral dose in MC suspension in all five species studied (20
mg/kg for mice, rats, and rabbits and 10 mg/kg for dogs and monkeys), suggesting
that once-daily administration of SCH 56592 in human subjects would be a
therapeutically effective dosage regimen.
PMID- 10681347
TI - Mutations in ribosomal protein L16 conferring reduced susceptibility to
evernimicin (SCH27899): implications for mechanism of action.
AB - A clinical isolate of Streptococcus pneumoniae (SP#5) that showed decreased
susceptibility to evernimicin (MIC, 1.5 microgram/ml) was investigated. A 4,255
bp EcoRI fragment cloned from SP#5 was identified by its ability to transform
evernimicin-susceptible S. pneumoniae R6 (MIC, 0.03 microgram/ml) such that the
evernimicin MIC was 1.5 microgram/ml. Nucleotide sequence analysis of this
fragment revealed that it contained portions of the S10-spc ribosomal protein
operons. The nucleotide sequences of resistant and susceptible isolates were
compared, and a point mutation (thymine to guanine) that causes an Ile52-Ser
substitution in ribosomal protein L16 was identified. The role of this mutation
in decreasing susceptibility to evernimicin was confirmed by direct
transformation of the altered L16 gene. The presence of the L16 mutation in the
resistant strain suggests that evernimicin is an inhibitor of protein synthesis.
This was confirmed by inhibition studies using radiolabeled substrates, which
showed that the addition of evernimicin at sub-MIC levels resulted in a rapid
decrease in the incorporation of radiolabeled isoleucine in a susceptible isolate
(SP#3) but was much less effective against SP#5. The incorporation of isoleucine
showed a linear response to the dose level of evernimicin. The incorporation of
other classes of labeled substrates was unaffected or much delayed, indicating
that these were secondary effects.
PMID- 10681348
TI - Synergistic antifungal activities of bafilomycin A(1), fluconazole, and the
pneumocandin MK-0991/caspofungin acetate (L-743,873) with calcineurin inhibitors
FK506 and L-685,818 against Cryptococcus neoformans.
AB - Cryptococcus neoformans is an opportunistic fungal pathogen that causes life
threatening infections of the central nervous system. Existing therapies include
amphotericin B, fluconazole, and flucytosine, which are limited by toxic side
effects and the emergence of drug resistance. We recently demonstrated that the
protein phosphatase calcineurin is required for growth at 37 degrees C and
virulence of C. neoformans. Because calcineurin is the target of potent
inhibitors in widespread clinical use, cyclosporine and FK506 (tacrolimus), it is
an attractive drug target for novel antifungal agents. Here we have explored the
synergistic potential of combining the calcineurin inhibitor FK506 or its
nonimmunosuppressive analog, L-685,818, with other antifungal agents and examined
the molecular basis of FK506 action by using genetically engineered fungal
strains that lack the FK506 target proteins FKBP12 and calcineurin. We
demonstrate that FK506 exhibits marked synergistic activity with the H(+)ATPase
inhibitor bafilomycin A(1) via a novel action distinct from calcineurin loss of
function. FK506 also exhibits synergistic activity with the pneumocandin MK
0991/caspofungin acetate (formerly L-743,873), which targets the essential beta
1,3 glucan synthase, and in this case, FK506 action is mediated via FKBP12
dependent inhibition of calcineurin. Finally, we demonstrate that FK506 and
fluconazole have synergistic activity that is independent of both FKBP12 and
calcineurin and may involve the known ability of FK506 to inhibit multidrug
resistance pumps, which are known to export azoles from fungal cells. In summary,
our studies illustrate the potential for synergistic activity of a variety of
different drug combinations and the power of molecular genetics to define the
mechanisms of drug action, as well as identify a novel action of FK506 that could
have profound implications for therapeutic or toxic effects in other organisms,
including humans.
PMID- 10681349
TI - Bloodstream infections due to Candida species: SENTRY antimicrobial surveillance
program in North America and Latin America, 1997-1998.
AB - An international program of surveillance of bloodstream infections (BSI) in the
United States, Canada, and Latin America detected 306 episodes of candidemia in
34 medical centers (22 in the United States, 6 in Canada, and 6 in Latin America)
in 1997 and 328 episodes in 34 medical centers (22 in the United States, 5 in
Canada, and 7 in Latin America) in 1998. Of the 634 BSI, 54.3% were due to
Candida albicans, 16.4% were due to C. glabrata, 14.9% were due to C.
parapsilosis, 8.2% were due to C. tropicalis, 1.6% were due to C. krusei, and
4.6% were due to other Candida spp. The percentage of BSI due to C. albicans
decreased very slightly in the United States between 1997 and 1998 (56.2 to
54.4%; P = 0.68) and increased in both Canada (52.6 to 70.1%; P = 0.05) and Latin
America (40.5 to 44. 6%; P = 0.67). C. glabrata was the second most common
species observed overall, and the percentage of BSI due to C. glabrata increased
in all three geographic areas between 1997 and 1998. C. parapsilosis was the
third most prevalent BSI isolate in both Canada and Latin America, accounting for
7.0 and 18.5% of BSI, respectively. Resistance to fluconazole (MIC, >/=64
microgram/ml) and itraconazole (MIC, >/=1.0 microgram/ml) was observed
infrequently in both 1997 (2.3 and 8.5%, respectively) and 1998 (1.5 and 7.6%,
respectively). Among the different species of Candida, resistance to fluconazole
and itraconazole was observed in C. glabrata and C. krusei, whereas isolates of
C. albicans, C. parapsilosis, and C. tropicalis were all highly susceptible to
both fluconazole (98.9 to 100% susceptible) and itraconazole (96.4 to 100%
susceptible). Isolates from Canada and Latin America were generally more
susceptible to both triazoles than U.S. isolates were. Continued surveillance
appears necessary to detect these important changes.
PMID- 10681350
TI - Indinavir pharmacokinetics and parmacodynamics in children with human
immunodeficiency virus infection.
AB - The indinavir dosage regimen currently used for human immunodeficiency virus
(HIV)-infected children is not based on pharmacokinetic data obtained in the
target patient population. The purpose of our study was to characterize indinavir
pharmacokinetics and pharmacodynamics in HIV-infected children. Eleven children
(age range, 9.0 to 13.6 years; weight range, 21.7 to 56.0 kg) receiving indinavir
(500 mg/m(2) every 8 h) in combination with lamivudine and stavudine were
studied. The correlation of indinavir pharmacokinetic parameters and demographic
parameters was evaluated. Also, the pharmacodynamic relationship between
parameters of indinavir exposure and parameters of renal toxicity and immunologic
recovery was studied. The area under the indinavir concentration-time curve (AUC)
and patient body surface area (BSA) showed a significant negative correlation (r
= 0.73; P = 0.012). Patients with smaller BSA had excessive indinavir AUC
compared to adults. On the other hand, the median minimum drug concentration in
plasma (C(min)) was lower than that reported for adults. The maximum indinavir
concentration in serum was higher in patients with renal toxicity (5 out of 11
children), but the difference was not statistically significant (15.3 +/- 8.2
versus 9.8 +/- 4.4 mg/liter; P = 0.19). There was a trend toward higher
immunologic efficacy in patients with greater indinavir exposure: the time
averaged AUC of the percentage of CD4(+) lymphocytes over the baseline value for
patients with indinavir C(min) > 95% inhibitory concentration (IC(95)) was higher
than in patients with C(min) < IC(95) (P = 0. 068). Our study suggests that a
dose reduction may be appropriate for children with small BSA and that a 6-h
dosage regimen may be indicated for a substantial percentage of patients. Due to
the low number of patients enrolled in this study, our results should be
confirmed by a larger study.
PMID- 10681351
TI - Intravitreal, retinal, and central nervous system foscarnet concentrations after
rapid intravenous administration to rabbits.
AB - Retinal, vitreous humor, brain, and cerebrospinal fluid (CSF) foscarnet levels
were measured by high-performance liquid chromatography after administration of
an intravenous dose of 120 mg/kg of body weight to 32 pigmented rabbits. A
pharmacokinetic analysis was done using a two-compartment model. The penetration
ratios, defined as ratios of retinal, vitreous humor, brain, and CSF areas under
the concentration-time curve from 0 to 2 h were 110% +/- 1%, 12.3% +/- 0.7%, 118%
+/- 1%, and 20.2% +/- 2.2%, respectively. These results suggest a good
penetration of foscarnet into the retinal and brain tissues, reaching higher
concentrations than those estimated from vitreous humor and CSF levels.
PMID- 10681352
TI - Capnocytophaga ochracea: characterization of a plasmid-encoded extended-spectrum
TEM-17 beta-lactamase in the phylum Flavobacter-bacteroides.
AB - A plasmid-encoded extended-spectrum TEM beta-lactamase with a pI of 5.5 was
detected in a Capnocytophaga ochracea clinical isolate. The bla gene was
associated with a strong TEM-2 promoter and was derived from bla(TEM-1a) with a
single-amino-acid substitution: Glu(104)-->Lys, previously assigned to TEM-17,
which is thus the first TEM beta-lactamase to be reported in the phylum
Flavobacter-Bacteroides.
PMID- 10681353
TI - Iron-chelating activity of tetracyclines and its impact on the susceptibility of
Actinobacillus actinomycetemcomitans to these antibiotics.
AB - Three tetracyclines (tetracycline, doxycycline, and minocycline) were found to
possess iron-chelating activity in a colorimetric siderophore assay.
Determination of MICs indicated that the activity of doxycycline against the
periodontopathogen Actinobacillus actinomycetemcomitans was only slightly
influenced by the presence of an excess of iron that likely saturates the
antibiotic. On the other hand, the MICs of doxycycline and minocycline were
significantly lower for A. actinomycetemcomitans cultivated under iron-poor
conditions than under iron-rich conditions.
PMID- 10681354
TI - Gemifloxacin is effective in experimental pneumococcal meningitis.
AB - In a rabbit model of Streptococcus pneumoniae meningitis, 5 mg of gemifloxacin
mesylate (SB-265805) per kg/h reduced the bacterial titers in cerebrospinal fluid
(CSF) almost as rapidly as 10 mg of ceftriaxone per kg/h (Deltalog CFU/ml/h +/-
standard deviation [SD], -0.25 +/- 0.09 versus -0.38 +/- 0.11; serum and CSF
concentrations of gemifloxacin were 2.1 +/- 1.4 mg/liter and 0.59 +/- 0.38
mg/liter, respectively, at 24 h). Coadministration of 1 mg of dexamethasone per
kg did not affect gemifloxacin serum and CSF levels (2.7 +/- 1.4 mg/liter and
0.75 +/- 0.34 mg/liter, respectively, at 24 h) or activity (Deltalog CFU/ml/h +/-
SD, -0.26 +/- 0.11).
PMID- 10681355
TI - Pulsed ultrasound enhances the killing of Escherichia coli biofilms by
aminoglycoside antibiotics in vivo.
AB - Escherichia coli biofilms on two polyethylene disks were implanted subcutaneously
into rabbits receiving systemic gentamicin. Ultrasound was applied for 24 h to
one disk. Both disks were removed, and viable bacteria were counted. Pulsed
ultrasound significantly reduced bacterial viability below that of nontreated
biofilms without damage to the skin.
PMID- 10681356
TI - Comparative activities of ciprofloxacin and levofloxacin against Streptococcus
pneumoniae in an In vitro dynamic model.
AB - The activities of levofloxacin (500 mg every 24 h) and ciprofloxacin (750 mg
every 12 h) against six pneumococcal isolates in an in vitro dynamic model were
compared. For one strain, levofloxacin reduced the inoculum by over 4 log CFU/ml
and ciprofloxacin reduced the inoculum by over 2 log CFU/ml. For four isolates,
both drugs reduced inocula by 4 log CFU/ml within 6 h, suggesting that this dose
of ciprofloxacin should be as effective as levofloxacin against these
pneumococci.
PMID- 10681357
TI - Occurrence of the new tetracycline resistance gene tet(W) in bacteria from the
human gut.
AB - Members of our group recently identified a new tetracycline resistance gene,
tet(W), in three genera of rumen obligate anaerobes. Here, we show that tet(W) is
also present in bacteria isolated from human feces. The tet(W) genes found in
human Fusobacterium prausnitzii and Bifidobacterium longum isolates were more
than 99.9% identical to those from a rumen isolate of Butyrivibrio fibrisolvens.
PMID- 10681358
TI - Postantibiotic effects and bactericidal activities of clarithromycin-14-hydroxy
clarithromycin, versus those of amoxicillin-clavulanate, against anaerobes.
AB - The bactericidal activities and postantibiotic effects (PAE) of clarithromycin-14
hydroxy-clarithromycin and amoxicillin-clavulanate against Bacteroides fragilis
and Peptostreptococcus anaerobius were determined. A concentration of twice the
MIC resulted in bactericidal activity against four of four and three of four
organisms at 24 h with clarithromycin-14-hydroxy-clarithromycin and amoxicillin
clavulanate, respectively. The PAE of clarithromycin-14-hydroxy-clarithromycin
was 1.44 to 3.20 h, compared to the less than 1 h of amoxicillin-clavulanate.
Clarithromycin-14-hydroxy-clarithromycin possesses good activity against
susceptible anaerobes.
PMID- 10681359
TI - Efficacy of SCH56592 in a rabbit model of invasive aspergillosis.
AB - SCH56592 (SCH) was evaluated in an immunosuppressed rabbit model of invasive
aspergillosis. SCH was more effective than similar doses of itraconazole and as
effective as amphotericin B in the clearance of Aspergillus spp. from tissues.
Compared with controls, SCH regimens reduced mortality, improved survival, and
significantly reduced tissue colony counts.
PMID- 10681360
TI - Antiviral activity of 2'-deoxy-3'-oxa-4'-thiocytidine (BCH-10652) against
lamivudine-resistant human immunodeficiency virus type 1 in SCID-hu Thy/Liv mice.
AB - Oral administration of 2'-deoxy-3'-oxa-4'-thiocytidine (BCH-10652), a nucleoside
analog structurally similar to lamivudine (3TC), caused dose-dependent inhibition
of viral replication in SCID-hu Thy/Liv mice infected with human immunodeficiency
virus type 1 NL4-3 and with an NL4-3 clone containing the M184V mutation in
reverse transcriptase that confers resistance to 3TC. These experiments
demonstrate the utility of this mouse model for evaluating drug resistance and
for performing direct comparisons between antiviral compounds in vivo.
PMID- 10681361
TI - Streptococcus gordonii strains resistant to fluorodeoxyuridine contain mutations
in the thymidine kinase gene and are deficient in thymidine kinase activity.
AB - Mutants of Streptococcus gordonii resistant to 5-fluorodeoxyuridine (FUdR(r))
were isolated. Each strain contained a point mutation resulting in the premature
termination of the thymidine kinase (TK) open reading frame (tdk). In vitro
translation of the mutant tdk coding regions resulted in synthesis of truncated
TK polypeptides deficient in TK activity.
PMID- 10681362
TI - Characterization of the Tn916-like transposon Tn3872 in a strain of abiotrophia
defectiva (Streptococcus defectivus) causing sequential episodes of endocarditis
in a child.
AB - Clinical blood isolates from three sequential episodes of endocarditis occurring
over a 6-month period in a child with a malformative cardiopathy were
investigated. All isolates identified as Abiotrophia defectiva were resistant to
erythromycin-clindamycin and to tetracycline-minocycline, due to the presence of
sequences homologous to the erythromycin resistance gene ermB and to the
tetracycline resistance gene tet(M), respectively. These resistance genes were
located on a chromosomally borne composite Tn916-related transposon. These
results demonstrate the involvement of conjugative transposons in the
dissemination of antibiotic resistance in the genus Abiotrophia.
PMID- 10681364
TI - A convenient assay for estimating the possible involvement of efflux of
fluoroquinolones by Streptococcus pneumoniae and Staphylococcus aureus: evidence
for diminished moxifloxacin, sparfloxacin, and trovafloxacin efflux.
AB - We developed a simplified assay for estimating efflux by measuring the effect of
reserpine on the growth of Streptococcus pneumoniae and Staphylococcus aureus
over 7 h. Reserpine enhanced ciprofloxacin and levofloxacin 17 to 68%. The
hydrophobic drug trovafloxacin and the drug moxifloxacin, with a bulky C-7
substituent but hydrophilicity similar to that of levofloxacin, showed little (0
to 11%) reserpine-enhancing effect. The ease of resistant mutant strain selection
correlated with efflux susceptibility.
PMID- 10681363
TI - Delavirdine susceptibilities and associated reverse transcriptase mutations in
human immunodeficiency virus type 1 isolates from patients in a phase I/II trial
of delavirdine monotherapy (ACTG 260).
AB - The development of human immunodeficiency virus type 1 resistance to delavirdine
(DLV) was studied in subjects receiving DLV monotherapy. Phenotypic resistance
developed in 28 of 30 subjects within 8 weeks. K103N and Y181C, which confer
nonnucleoside reverse transcriptase inhibitor (NNRTI) cross-resistance, were the
predominant reverse transcriptase mutations. P236L, which confers DLV resistance
but hypersensitivity to other NNRTIs, developed in <10% of isolates.
PMID- 10681365
TI - Comparative in vitro activities of ciprofloxacin, gemifloxacin, grepafloxacin,
moxifloxacin, ofloxacin, sparfloxacin, trovafloxacin, and other antimicrobial
agents against bloodstream isolates of gram-positive cocci.
AB - The in vitro activity of gemifloxacin against 316 bloodstream isolates of
staphylococci, pneumococci, and enterococci was compared with the activities of
six fluoroquinolones and three other antimicrobial agents. Of the antimicrobial
agents tested, gemifloxacin was the most potent against penicillin-intermediate
and -resistant pneumococci, methicillin-susceptible and -resistant Staphylococcus
epidermidis isolates, and coagulase-negative staphylococci.
PMID- 10681366
TI - Editorial
PMID- 10681367
TI - In vitro-in vivo scaling of CYP kinetic data not consistent with the classical
Michaelis-Menten model.
AB - Strategies for the prediction of in vivo drug clearance from in vitro drug
metabolite kinetic data are well established for the rat. In this animal species,
metabolism rate-substrate concentration relationships can commonly be described
by the classic hyperbola consistent with the Michaelis-Menten model and simple
scaling of the parameter intrinsic clearance (CL(int) - the ratio of V(max) to
K(m)) is particularly valuable. The in vitro scaling of kinetic data from human
tissue is more complex, particularly as many substrates for cytochrome P450 (CYP)
3A4, the dominant human CYP, show nonhyperbolic metabolism rate-substrate
concentration curves. This review critically examines these types of data, which
require the adoption of an enzyme model with multiple sites showing cooperative
binding for the drug substrate, and considers the constraints this kinetic
behavior places on the prediction of in vivo pharmacokinetic characteristics,
such as metabolic stability and inhibitory drug interaction potential. The cases
of autoactivation and autoinhibition are discussed; the former results in an
initial lag in the rate-substrate concentration profile to generate a sigmoidal
curve whereas the latter is characterized by a convex curve as V(max) is not
maintained at high substrate concentrations. When positive cooperativity occurs,
we suggest the use of CL(max), the maximal clearance resulting from
autoactivation, as a substitute for CL(int). The impact of heteroactivation on
this approach is also of importance. In the case of negative cooperativity, care
in using the V(max)/K(m) approach to CL(int) determination must be taken.
Examples of substrates displaying each type of kinetic behavior are discussed for
various recombinant CYP enzymes, and possible artifactual sources of atypical
rate-concentration curves are outlined. Finally, the consequences of ignoring
atypical Michaelis-Menten kinetic relationships are examined, and the
inconsistencies reported for both different substrates and sources of recombinant
CYP3A noted.
PMID- 10681368
TI - Bioactivation and covalent binding of hydroxyfluperlapine in human neutrophils:
implications for fluperlapine-induced agranulocytosis.
AB - The use of fluperlapine and the structurally related clozapine has been
associated with the induction of agranulocytosis in humans. Unlike clozapine,
fluperlapine is relatively resistant to chemical and biochemical oxidations. In
this study we demonstrated that 7-hydroxyfluperlapine, the major metabolite of
fluperlapine in humans, is oxidized to a reactive intermediate by HOCl and by
myeloperoxidase in the presence of H(2)O(2) and Cl(-). This reactive intermediate
was identified as an iminoquinone species with a M + 1 ion at m/z 324 by mass
spectrometry. The iminoquinone intermediate was trapped by N-acetyl-L-cysteine
(NAC) as well as GSH. NMR spectra of the NAC adducts indicated that the NAC was
bound to the 6 and 9 positions of the aromatic ring. This is the same orientation
as the binding of nucleophiles to the reactive metabolite of clozapine. We were
able to use an antibody against clozapine to demonstrate that 7
hydroxyfluperlapine, but not fluperlapine itself, covalently modifies human
myeloperoxidase. Furthermore, we demonstrated that 7-hydroxyfluperlapine is
metabolized by activated neutrophils to a reactive intermediate that covalently
binds to neutrophils. In the presence of NAC or GSH, such covalent binding was
inhibited and the NAC or GSH adducts were formed. Thus, the reactivity and even
the orientation of the binding of the reactive metabolite of 7
hydroxyfluperlapine is very similar to that of clozapine. These results provide a
mechanism for the formation of a reactive metabolite of fluperlapine similar to
clozapine that may explain its ability to induce agranulocytosis.
PMID- 10681369
TI - The role of mdr1a P-glycoprotein in the biliary and intestinal secretion of
doxorubicin and vinblastine in mice.
AB - Drug-transporting P-glycoproteins are abundantly present in the liver and the
intestinal wall. We have now investigated their role in the biliary and
intestinal secretion of the anticancer drugs doxorubicin (unlabeled: 5 mg/kg) and
vinblastine ((3)H-labeled: 1 mg/kg) i.v. administered to wild-type and mdr1a P
glycoprotein knockout [mdr1a(-/-)] mice. At 90 min after drug administration,
levels of unchanged drug and metabolites in plasma, intestinal contents, and bile
were determined by high-performance liquid chromatography and radioactivity by
liquid scintillation counting. The bile of both wild-type and mdr1a(-/-) mice
contained only minor amounts of unchanged vinblastine, whereas the total biliary
secretion of unknown (3)H-labeled breakdown products was about 25 to 30% of the
dose. The direct secretion of unchanged vinblastine through the gut wall was 6.7
and 3.3% of the dose in wild-type and mdr1a(-/-) mice, respectively. The biliary
secretion of unchanged doxorubicin decreased from 13.3% of the dose to only 2.4%
in the absence of mdr1a P-glycoprotein. Approximately 10% of the dose was
secreted as unchanged doxorubicin into the intestinal contents of both types of
mice. Thus, the absence of mdr1a P-glycoprotein affects the fate of vinblastine
chiefly by diminishing secretion into the lumen of the small intestine, whereas
it affects the fate of doxorubicin chiefly by diminishing secretion of parent
drug into bile.
PMID- 10681370
TI - The glucocorticoid receptor is essential for induction of cytochrome P-4502B by
steroids but not for drug or steroid induction of CYP3A or P-450 reductase in
mouse liver.
AB - Cytochrome P-4503A, CYP2B, and P-450 reductase are induced by glucocorticoids,
antiglucocorticoids such as pregnenolone 16alpha-carbonitrile, and drugs such as
rifampin and phenobarbital. Although the pregnane X receptor is reported to
mediate steroid and drug activation of CYP3A via a conserved cis-element in CYP3A
genes, discrepancies exist between the induction of the endogenous CYP3A genes
and the activation of the pregnane X receptor. It is a formal possibility that
the glucocorticoid receptor may account for some of these discrepancies. To
determine the requirement in vivo of the glucocorticoid receptor in expression of
CYP3A and CYP2B, we compared the induction of these proteins in the livers of
normal mice and mice with a targeted mutation in the glucocorticoid receptor.
Mice lacking the glucocorticoid receptor show no difference in constitutive
hepatic expression of CYP3A but show a decrease in the level of CYP2B.
Glucocorticoid receptor-deficient mice challenged with either dexamethasone or
pregnenolone 16alpha-carbonitrile failed to induce CYP2B proteins, whereas CYP2B
was readily induced in (+/+) mice. In contrast, CYP3A and P-450 reductase
proteins were induced by either inducer in wild-type and glucocorticoid receptor
null mice. Similarly, rifampin induced CYP3A in either wild-type or
glucocorticoid receptor-null mice. Despite reports that rifampin is a
nonsteroidal ligand for the human glucocorticoid receptor, rifampin failed to
induce tyrosine aminotransferase in mice regardless of glucocorticoid receptor
genotype, and rifampin did not compete for ligand binding to either mouse or
human glucocorticoid receptor. Phenobarbital induced CYP3A, CYP2B, and P-450
reductase in all mice, but the amplitude of induction was diminished 37% in
glucocorticoid receptor-null mice. Thus, there are distinctly different essential
requirements of CYP3A, CYP2B, and P-450 reductase genes for the glucocorticoid
receptor in their induction by steroids and drugs.
PMID- 10681371
TI - Diphenhydramine disposition in the sheep maternal-placental-fetal unit:
gestational age, plasma drug protein binding, and umbilical blood flow effects on
clearance.
AB - The objective of this study was to examine the interrelationships between
maternal and fetal plasma drug protein binding, umbilical blood flow (Q(um)),
gestational age (GA), and maternal-fetal diphenhydramine (DPHM) clearances in
chronically instrumented pregnant sheep. Maternal and fetal DPHM placental
(CL(mf) and CL(fm), respectively) and nonplacental (CL(mo) and CL(fo),
respectively) clearances and steady-state plasma protein binding were determined
in 18 pregnant sheep at 124 to 140 days' gestation (term, approximately 145
days). The data demonstrated a highly significant fall of approximately 66% in
CL(fm) and a decreasing trend in CL(fo) ( approximately 47%) over the GA range
studied. However, no such relationships existed between GA and CL(mf) or CL(mo).
Concomitant with this was a decrease in fetal DPHM plasma unbound fraction with
GA, with no such change being evident in the mother. Both CL(mo) and CL(fo) were
related to the respective DPHM plasma unbound fraction. A strong relationship
also existed between fetal plasma unbound fraction and CL(fm). Thus, the decrease
in fetal unbound fraction of DPHM during gestation could contribute to the fall
in CL(fm), and possibly CL(fo). However, over the GA range studied, fetal DPHM
free fraction decreased by approximately 47%, whereas CL(fm) fell by
approximately 66%. Because fetal unbound fraction and CL(fm) are linearly
related, the GA-associated fall in unbound fraction appears to be insufficient to
account for the entire decline in CL(fm). In separate studies in pregnant sheep,
we observed a approximately 40% fall in weight-normalized Q(um) between 125 and
137 days' gestation. Because CL(fm) for DPHM is similar to that of flow-limited
compounds (e.g., ethanol, antipyrine), this decrease in Q(um) may also contribute
to the GA-related fall in CL(fm).
PMID- 10681372
TI - Incorporation and retention of radiolabeled S-(+)-and R-(-)-methamphetamine and
S(+)- and R(-)-N-(n-butyl)-amphetamine in mouse hair after systemic
administration.
AB - We examined the incorporation of unlabeled and tritiated enantiomers of
methamphetamine (MA) and a more lipophilic analog N-(n-butyl)-amphetamine (BA)
into the hair of pigmented (C57) and nonpigmented (Balb/C) mice after systemic
administration. We also compared the ability of extraction methods to remove
unlabeled and tritiated MA and BA enantiomers from the hair. R(-)-MA, S(+)-MA,
[(3)H]R(-)-MA, [(3)H]S(+)-MA, R(-)-BA, S(+)-BA, [(3)H]R-(-)-BA, and [(3)H]S-(+)
BA were each administered to C57 and Balb/C mice (23 days of age) by i.p.
injection at 8.8 mg/kg daily for 3 days. At 44 days of age, hair samples from the
animals were treated with a brief methanol wash, a 24-h extraction with pH 6
phosphate buffer, and a final digestion in 1 N NaOH to free residual drugs from
the hair. Labeled drugs in the extracts were quantitated by liquid scintillation
counting. Unlabeled drugs were quantitated by gas chromatography/mass
spectrometry (GC/MS). GC/MS analysis demonstrated MA and BA to be the major
(>90%) species present in the blood during the 24 h after administration. Less
than 10% of the MA was N-demethylated. No p-hydroxylated metabolites were found.
Blood concentrations of tritiated MA and BA enantiomers measured by liquid
scintillation counting agreed well with blood concentrations of unlabeled
enantiomers measured by GC/MS. Hair concentrations of S(+)-MA were greater than
those of R(-)-MA in both mouse strains, paralleling blood concentrations. There
were no enantiomeric differences seen with BA hair accumulation in either strain
of mouse. Significantly more MA and BA enantiomers were deposited in pigmented
than in nonpigmented hair. With labeled and unlabeled compounds, approximately
30% of S(+)-MA and 60% of R(-)-MA in pigmented hair could be removed by a
phosphate extraction. A significant amount of drug could not be removed from the
hair by extraction. Greater amounts of drug could be extracted from nonpigmented
hair than pigmented. Extracted and residual MA and BA concentrations in pigmented
hair were significantly greater when labeled compounds were quantitated by liquid
scintillation counting than when unlabeled compounds were quantitated by GC/MS.
However, radiotracer and unlabeled drug concentrations were the same in
nonpigmented hair. The results demonstrate that hair pigmentation is an important
determinant in MA and BA deposition, and that MA and BA deposition is not
enantioselective. The data demonstrate a significant amount of MA and BA
accumulated is not easily amenable to exhaustive aqueous extraction from the
hair. The use of tritiated MA and BA enantiomers demonstrates that a significant
amount of MA and BA stored in pigmented hair is structurally different from
parent MA and BA, perhaps associated with melanin components of hair.
PMID- 10681373
TI - Human cytochrome P-450 metabolism of retinals to retinoic acids.
AB - Retinoic acids have important pleiotropic biological effects and thus the
potential for human cytochrome P-450s (CYPs) to mediate retinoic acid synthesis
was investigated. We examined the retinoic acid synthetic activity of human cDNA
expressed CYP1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4, 3A4+
cytochrome b(5) (b(5)), 3A5, and 4A11, expressed individually in insect cells
together with NADPH-P-450 reductase. Only CYP1A1, 1A2, 1B1, and 3A4+b(5)
converted all-trans-retinal (20 microM) to all-trans-retinoic acid with turnover
numbers of 0.53, 0.18, 0.20, and 0.41 nmol/min/nmol P-450, respectively. With 9
cis-retinal as substrate, CYP1A2 exhibited a turnover number of 1.58
nmol/min/nmol P-450 whereas CYP1A1, 2C19, and 3A4+b(5) had turnover numbers of
0.40, 0.27, and 0.41 nmol/min/nmol P-450, respectively. For CYP3A4 activities
with both retinals, b(5) was required. Kinetic analyses revealed that CYP1A1,
1A2, and 3A4+b(5) with all-trans-retinal had apparent K(m) values of 55, 356, and
255 microM, and V(max) values of 2.0, 8.3, and 6.3 nmol/min/nmol P-450,
respectively, and with 9-cis-retinal had K(m) values of 77, 91, and 368 microM,
and V(max) values of 2.7, 9.7, and 7.6 nmol/min/nmol P-450, respectively. The 9
cis retinoic acid synthetic activity of a group of 12 human liver microsomes
correlated only with the CYP1A2 activity (r = 0.96), implicating CYP1A2 in human
liver microsomal metabolism of 9-cis- retinal to 9-cis-retinoic acid. These
studies have indicated that human CYPs are capable of catalyzing retinal to
retinoic acid metabolism, but the physiological relevance of this metabolism is
still unclear.
PMID- 10681374
TI - Analysis of soy isoflavone conjugation in vitro and in human blood using liquid
chromatography-mass spectrometry.
AB - Soybean products containing isoflavones are widely consumed in Western and Asian
diets for putative health benefits, but adverse effects are also possible. The
conjugated forms of isoflavones present in a soy nutritional supplement
(predominately acetyl glucosides) and in blood from two human volunteers after
consuming the supplement (7- and 4'-glucuronides and sulfates) were identified
using liquid chromatography coupled with electrospray/tandem mass spectrometry.
Circulating conjugates of genistein and daidzein were quantified using selective
enzymatic hydrolysis and deuterated internal standards for liquid chromatography
electrospray/mass spectrometry. The levels of isoflavone glucuronides were much
greater than the corresponding sulfates or aglycones. The substrate activities of
genistein and daidzein were evaluated with recombinant human UDP glucuronosyl
transferase (UGT) and sulfotransferase (SULT) by using enzyme kinetics. The SULTs
1A1*2, 1E, and 2A1 catalyzed formation of a single genistein sulfate; however,
SULTs 1A2*1 and 1A3 had no observed activity. None of the SULTs showed activity
with daidzein. Although several UGTs (1A1, 1A4, 1A6, 1A7, 1A9, and 1A10)
catalyzed 7- and 4'-glucuronidation of genistein or daidzein, the UGT 1A10
isoform, which is found in human colon but not liver, was found to be specific
for genistein. Glucuronidation of only genistein was observed in human colon
microsomes, although nearly equal activity was observed for daidzein in human
liver and kidney microsomes. These findings suggest a prominent role for
glucuronidation of genistein in the intestine concomitant with absorption,
although hepatic glucuronidation of absorbed genistein and daidzein aglycones is
also likely.
PMID- 10681375
TI - Metabolism and excretion of [(14)C]celecoxib in healthy male volunteers.
AB - We determined the disposition of a single 300-mg dose of [(14)C]celecoxib in
eight healthy male subjects. The [(14)C]celecoxib was administered as a fine
suspension reconstituted in 80 ml of an apple juice/Tween 80/ethanol mixture.
Blood and saliva samples were collected at selected time intervals after dosing.
All urine and feces were collected on the 10 consecutive days after dose
administration. Radioactivity in each sample was determined by liquid
scintillation counting or complete oxidation and liquid scintillation counting.
Metabolic profiles in plasma, urine, and feces were obtained by HPLC, and
metabolites were identified by mass spectrometry and NMR. [(14)C]Celecoxib was
well absorbed, reaching peak plasma concentrations within 2 h of dosing.
[(14)C]Celecoxib was extensively metabolized, with only 2.56% of the radioactive
dose excreted as celecoxib in either urine or feces. The total percentage of
administered radioactive dose recovered was 84.8 +/- 4.9%, with 27.1 +/- 2.2% in
the urine and 57.6 +/- 7.3% in the feces. The oxidative metabolism of celecoxib
involved hydroxylation of celecoxib at the methyl moiety followed by further
oxidation of the hydroxyl group to form a carboxylic acid metabolite. The
carboxylic acid metabolite of celecoxib was conjugated with glucuronide to form
the 1-O-glucuronide. The percentages of the dose excreted in the feces as
celecoxib and the carboxylic acid metabolite were 2.56 +/- 1.09 and 54.4 +/-
6.8%, respectively. The majority of the dose excreted in the urine was the
carboxylic acid metabolite (18.8 +/- 2.1%); only a small amount was excreted as
the acyl glucuronide (1.48 +/- 0.15%).
PMID- 10681376
TI - Biosynthesis of all-trans-retinoic acid from all-trans-retinol: catalysis of all
trans-retinol oxidation by human P-450 cytochromes.
AB - Oxidative conversion of all-trans-retinol (t-ROH) to all-trans-retinal (t-RAL) is
recognized as the rate-limiting step for biosynthesis of all-trans-retinoic acid
from t-ROH in mammalian hepatic tissues. The purpose of this study was to
investigate the role of human cytochrome P-450 (CYP)-dependent monooxygenation in
the conversion of t-ROH to t-RAL. Adult human liver microsomes (HLMS) were
incubated with t-ROH, and retinoids generated were identified and quantified by
liquid chromatography-mass spectroscopy, HPLC, and other methods. HLMS-catalyzed
generation of t-RAL from t-ROH was primarily NADPH-dependent and was strongly
inhibited by carbon monoxide. Rates of reactions increased linearly with time and
concentrations of HLMS, and exhibited classical substrate saturation. These
observations strongly indicated that the reaction proceeded via CYP-catalyzed
monooxygenation. On the basis of responses to selective chemical inhibitors,
isoforms from CYP family 1 and the CYP3A subfamily appeared to be very active.
Members of the CYP2C subfamily and CYP2D6 exhibited lesser activities and CYP2A6,
CYP2B6, and CYP2E1 were virtually inactive. cDNA-expressed human CYP enzymes (CYP
SUPERSOMES) also were used to assess the capacity of individual CYP enzymes to
catalyze the reaction. Based on responses to selective chemical inhibitors,
specific activities, and levels present in adult human hepatic tissues, CYP1A2
and CYP3A4 strongly appeared to be the major CYP enzymes catalyzing hepatic
oxidative conversion of t-ROH to t-RAL in the adult human liver. CYP1A1 and
CYP1B1 SUPERSOMES both exhibited exceptionally high activities, and in
extrahepatic tissues, these isoforms could play important roles in biosynthesis
of all-trans-retinoic acid from t-ROH.
PMID- 10681377
TI - Input rate as a major determinant of furosemide pharmacodynamics: influence of
fluid replacement and hypoalbuminemia.
AB - To investigate how the response to a bolus and an infusion of furosemide is
modulated by the rate of fluid replacement and by hypoalbuminemia, rabbits
received 5 mg/kg of furosemide as a bolus or infused over 60 min, whereas
diuresis was replaced with 13, 121, or 238 ml/h NaCl 0.9%/glucose 5% (50:50).
Natriuretic and diuretic efficiencies were greater with the infusion than with
the bolus of furosemide. Fluid replacement increased natriuretic and diuretic
efficiency of furosemide bolus but only diuretic efficiency of furosemide
infusion. Furosemide net fluid depletion reached a plateau when fluid replacement
increased beyond 121 ml/h. Repeated plasmapheresis decreased plasma albumin by
30% (P <.05) and increased furosemide unbound fraction (P <.05). Compared with
control rabbits, hypoalbuminemia decreased the natriuresis of the bolus (22.7 +/-
1.5-16.6 +/- 1.3 mmol, P <.05) but not that elicited by furosemide infusion (26.2
+/- 1.8 mmol). Given as a bolus, furosemide natriuretic and diuretic response as
a function of its urinary rate of excretion exhibited an hyperbolic relationship,
and after its infusion a clockwise hysteresis, denoting tolerance. Plasma renin
activity was increased by the bolus and the infusion of furosemide, even in the
presence of 121 ml/h of fluid replacement. It is concluded that: 1) the increase
in natriuretic/diuretic efficiency of the bolus induced by fluid replacement is
greater than when furosemide is infused, 2) furosemide net effect does not
increase proportionally to fluid replacement, and 3) the infusion of furosemide
prevents the hypoalbuminemia-induced decrease in response of furosemide given as
a bolus.
PMID- 10681378
TI - Interactions of HIV protease inhibitors with a human organic cation transporter
in a mammalian expression system.
AB - Recently, we cloned a human organic cation transporter, hOCT1, which is expressed
primarily in the liver. hOCT1 plays an important role in the cellular uptake and
elimination of various xenobiotics including therapeutically important drugs. HIV
protease inhibitors are a new class of therapeutic agents. The purpose of this
study was to elucidate the interactions of HIV protease inhibitors with hOCT1 and
to determine whether hOCT1 is involved in the elimination of these compounds. We
studied the interactions of HIV protease inhibitors with hOCT1 in a transiently
transfected human cell line, HeLa. Uptake studies were carried out 40 h post
transfection using the radiolabeled model organic cation,
[(14)C]tetraethylammonium (TEA), under different experimental conditions. In cis
inhibition studies, all of the HIV protease inhibitors tested, i.e., indinavir
(IC(50) of 62 microM), nelfinavir (IC(50) of 22 microM), ritonavir (IC(50) of 5.2
microM), and saquinavir (IC(50) of 8.3 microM) inhibited TEA uptake in HeLa cells
expressing hOCT1. However, none of the HIV protease inhibitors trans-stimulated
[(14)C]TEA uptake, suggesting that they are poorly translocated by hOCT1.
Nelfinavir, ritonavir, and saquinavir demonstrated an apparent "trans-inhibition"
effect. No enhanced uptake of [(14)C]saquinavir was observed in hOCT1 DNA
transfected cells versus empty vector-transfected cells. These data suggest that
HIV protease inhibitors are potent inhibitors, but poor substrates, of hOCT1.
Some HIV protease inhibitors may potently inhibit the uptake and elimination of
cationic drugs that are substrates for hOCT1, leading to potential drug-drug
interactions. Other transporters, e.g., MDR1 and MRP1, in HIV-targeted cells may
control the intracellular concentrations of HIV protease inhibitors.
PMID- 10681379
TI - m-hydroxy benzoylecgonine recovery in fetal guinea pigs.
AB - Recently, meta-hydroxybenzoylecgonine (m-OH BE) was identified by gas
chromatography-mass spectroscopy during quantitative analysis for cocaine.
Identification of m-OH BE in addition to the routinely identified benzoylecgonine
by gas chromatography-mass spectroscopy confirmatory assays may increase
detection of cocaine-exposed infants and decrease false negative results.
However, it is not known whether m-OH BE is derived directly from benzoylecgonine
or from hydroxylated cocaine, or whether this metabolite is produced in the fetus
or transferred across the placenta from the maternal circulation. We quantitated
the recovery of cocaine, benzoylecgonine, and m-OH BE from amniotic fluid, fetal
meconium, fetal intestine, and maternal urine for up to 4 days after single dose
administration of either cocaine or benzoylecgonine to pregnant time-bred guinea
pigs. m-OH BE was recovered from meconium after maternal injections of cocaine
and benzoylecgonine. There was no significant detection of m-OH BE from amniotic
fluid or intestine and minimal recovery from maternal urine after either cocaine
or benzoylecgonine administration. Detection of m-OH BE in meconium increased the
identification of in utero exposed guinea pigs, and the greatest yield of m-OH BE
from meconium occurred later than that observed for cocaine or benzoylecgonine.
PMID- 10681380
TI - On the metabolism of the amphetamine-derived antispasmodic drug mebeverine: gas
chromatography-mass spectrometry studies on rat liver microsomes and on human
urine.
AB - We describe gas chromatography-mass spectrometry studies of the metabolism of the
antispasmodic drug mebeverine [Duspatal, (MB)]. MB is the veratric acid (VA)
ester of 4-?ethyl-[2-(4-methoxyphenyl)-1-methylethyl]amino?butan-1-ol (MB-OH),
which is an N-substituted ethylamphetamine derivative. The metabolites were first
identified in rat liver microsome incubates and then detected in urine samples of
volunteers through the use of electron impact and positive chemical ionization
gas chromatography-mass spectrometry. Urinary conjugates were enzymatically
cleaved before analysis. The following phase I metabolites of MB could be
identified: VA, O-demethyl VA (vanillic and/or isovanillic acid), O-bisdemethyl
VA (protocatechuic acid), MB-OH, hydroxy MB-OH, O-demethyl MB-OH, O-demethyl
hydroxy MB-OH, N-desethyl MB-OH, N-desethyl-O-demethyl MB-OH, N-de(hydroxybutyl)
MB-OH (methoxy-ethylamphetamine), N-de(hydroxybutyl)-O-demethyl MB-OH (hydroxy
ethylamphetamine), and N-bisdealkyl MB-OH (p-methoxy-amphetamine, known as the
designer drug PMA). The following, partly overlapping metabolic pathways of MB
could be postulated: ester hydrolysis, O-demethylation, ring hydroxylation, N
deethylation, and N-de(hydroxybutylation). The latter pathway led to
ethylamphetamine derivatives and bisdealkylation led to PMA, which are substances
of forensic interest. The metabolites containing alcoholic or phenolic hydroxy
groups were partly excreted into urine as conjugates.
PMID- 10681381
TI - Selective involvement of cytochrome P450 2D subfamily in in vivo 4-hydroxylation
of amphetamine in rat.
AB - The cytochrome P450 (P450) 2D subfamily catalyzes ring hydroxylation of
amphetamines. We tested the hypothesis that P450 2D is selectively involved in
amphetamine 4-hydroxylation. Urinary elimination of 4-hydroxyamphetamine and
amphetamine was determined in male Sprague-Dawley rats pretreated with P450
inducers and inhibitors. The urinary 24-h metabolic ratio (amphetamine/4
hydroxyamphetamine) was not affected by the inducers 3-methylcholanthrene,
isosafrole, phenobarbital, ethanol, pregnenolone-alpha-carbonitrile, and
clofibrate. Isosafrole did, however, increase amphetamine elimination along with
urine volume. Urinary elimination of 4-hydroxyamphetamine was significantly
decreased by, and the metabolic ratio increased by, the inhibitors 1
aminobenzotriazole, CCl(4), quinidine, quinine, and primaquine. Diallyl sulfide
and troleandomycin had no effect. In rat liver microsomes primaquine was shown to
be an inhibitor of 2D activity. Urine 4-hydroxyamphetamine content correlated
strongly (r(2) = 0. 989) with microsomal P450 2D activity in parallel-treated
rats. These studies also substantiate that 4-hydroxylation of amphetamine is
selectively performed by the P450 2D subfamily in the rat.
PMID- 10681382
TI - CYP2C19 participates in tolbutamide hydroxylation by human liver microsomes.
AB - Tolbutamide is a sulfonylurea-type oral hypoglycemic agent whose action is
terminated by hydroxylation of the tolylsulfonyl methyl moiety catalyzed by
cytochrome P-450 (CYP) enzymes of the human CYP2C subfamily. Although most
studies have implicated CYP2C9 as the exclusive catalyst of hepatic tolbutamide
hydroxylation in humans, there is evidence that other CYP2C enzymes (e.g.,
CYP2C19) may also participate. To that end, we used an immunochemical approach to
assess the role of individual CYP2Cs in microsomal tolbutamide metabolism.
Polyclonal antibodies were raised to CYP2C9 purified from human liver, and were
then back-adsorbed against recombinant CYP2C19 coupled to a solid-phase support.
Western blotting revealed that the absorbed anti-human CYP2C9 preparation reacted
with only recombinant CYP2C9 and the corresponding native protein in hepatic
microsomes, and no longer recognized CYP2C19 and CYP2C8. Monospecific anti-CYP2C9
not only retained the ability to inhibit CYP2C9-catalyzed reactions, as evidenced
by its marked (90%) inhibition of diclofenac 4'-hydroxylation by purified CYP2C9
and by human liver microsomes, but also exhibited metabolic specificity, as
indicated by its negligible (<15%) inhibitory effect on S-mephenytoin 4'
hydroxylation by purified CYP2C19 or hepatic microsomes containing CYP2C19.
Monospecific anti-CYP2C9 was also found to inhibit rates of tolbutamide
hydroxylation by 93 +/- 4 and 78 +/- 6% in CYP2C19-deficient and CYP2C19
containing human liver microsomes, respectively. Taken together, our results
indicate that both CYP2C9 and CYP2C19 are involved in tolbutamide hydroxylation
by human liver microsomes, and that CYP2C19 underlies at least 14 to 22% of
tolbutamide metabolism. Although expression of CYP2C19 in human liver is less
than that of CYP2C9, it may play an important role in tolbutamide disposition in
subjects expressing either high levels of CYP2C19 or a catalytically deficient
CYP2C9 enzyme.
PMID- 10681383
TI - Human cytochrome P-450 3A4: in vitro drug-drug interaction patterns are substrate
dependent.
AB - Testosterone, terfenadine, midazolam, and nifedipine, four commonly used
substrates for human cytochrome P-450 3A4 (CYP3A4), were studied in pairs in
human liver microsomes and in microsomes from cells containing recombinant human
CYP3A4 and P-450 reductase, to investigate in vitro substrate-substrate
interaction with CYP3A4. The interaction patterns between compounds with CYP3A4
were found to be substrate-dependent. Mutual inhibition, partial inhibition, and
activation were observed in the testosterone-terfenadine, testosterone-midazolam,
or terfenadine-midazolam interactions. However, the most unusual result was the
interaction between testosterone and nifedipine. Although nifedipine inhibited
testosterone 6beta-hydroxylation in a concentration-dependent manner,
testosterone did not inhibit nifedipine oxidation. Furthermore, the effect of
testosterone and 7,8-benzoflavone on midazolam 1'-hydroxylation and 4
hydroxylation demonstrated different regiospecificities. These results may be
explained by a model in which multiple substrates or ligands can bind
concurrently to the active site of a single CYP3A4 molecule. However, the
contribution of separate allosteric sites and conformational heterogeneity to the
atypical kinetics of CYP3A4 can not be ruled out in this model.
PMID- 10681384
TI - Butyrylcholinesterase accelerates cocaine metabolism: in vitro and in vivo
effects in nonhuman primates and humans.
AB - Butyrylcholinesterase (BChE) is known to metabolize cocaine in humans. In the
present study, three different experiments were performed to determine whether
the addition of horse serum-derived BChE would accelerate the metabolism of
cocaine. In the first experiment, the addition of BChE to squirrel monkey plasma
in vitro reduced the half-life of cocaine by over 80%, decreased the production
of the metabolic product benzoylecgonine, and increased ecgonine methyl ester
formation. The effect of BChE on cocaine metabolism was reversed by a specific
BChE inhibitor. In the second, in vivo, experiment, exogenously administered BChE
reduced peak cocaine concentrations when given to anesthetized squirrel monkeys.
Finally, incubation of cocaine with added BChE in human plasma in vitro resulted
in a decrease in cocaine half-life similar to that observed with squirrel monkey
plasma. The magnitude of the decrease in cocaine half-life was proportional to
the amount of added BChE. Together, these results indicate that exogenously
administered BChE can accelerate cocaine metabolism in such a way as to
potentially lessen the behavioral and toxic effects of cocaine. Therefore, BChE
may be useful as a treatment for cocaine addiction and toxicity.
PMID- 10681385
TI - Immunohistochemical localization of taurine in the male reproductive organs of
the rat.
AB - The amino acid taurine has been implicated in several aspects of reproductive
system physiology. However, its localization in these organs has not been
previously analyzed. The aim of this study was to characterize its distribution
in male rat reproductive organs by immunohistochemical methods. Taurine was
localized in the smooth muscle cells of the tissues studied and in the skeletal
fibers of the cremaster muscle. In the testis, taurine was found in Leydig cells,
vascular endothelial cells, and other interstitial cells. No immunoreactivity was
observed in the cells of the seminiferous tubules, either in germ cells at all
spermatogenic stages or in Sertoli cells. However, peritubular myoid cells were
immunostained. Most epithelial cells of the efferent ducts were immunolabeled,
whereas the epithelial cells of the rete testis (extratesticular segments),
epididymis (caput, corpus, and cauda regions), and ductus deferens were
unstained. However, most epithelial cells from the intratesticular segments of
the rete were immunopositive. Some cells identified as intraepithelial
macrophages and lymphocytes, apical cells, and narrow cells were intensely
immunolabeled. Regional differences in the distribution of these cell types along
the ducts studied were also noted. The possible functional roles for taurine in
these cells are discussed.
PMID- 10681386
TI - Heat-induced alterations in the localization of HSP72 and HSP73 as measured by
indirect immunohistochemistry and immunogold electron microscopy.
AB - The heat shock proteins are a family of stress-inducible proteins that act as
molecular chaperones for nascent proteins and assist in protection and repair of
proteins whose conformation is altered by stress. HSP72 and HSP73 are two major
cytosolic/nuclear stress proteins of mammalian cells, with extensive sequence
homology. HSP73 is constitutively expressed, whereas HSP72 is highly stress
inducible. However, it is unclear why two isoforms are expressed and whether
these two proteins have different functions in the cell. To assist in the
delineation of function, we have completed a detailed study of the localization
of HSP72 and HSP73 in the cell before and after heat stress, using two different
methods of detection. By indirect immunohistochemistry, the localization of these
two proteins is similar, cytoplasmic and nuclear in nonstressed cells with a
translocation to nucleoli immediately after heat. By the more sensitive
immunogold electron microscopy technique, differences in localization were noted.
In nonstressed cells, HSP72 was primarily nuclear, localized in heterochromatic
regions and in nucleoli. HSP73 was distributed throughout the cell, with most
cytoplasmic label associated with mitochondria. Mitotic chromosomes were also
heavily labeled. After stress, HSP72 concentrated in nuclei and nucleoli and
HSP73 localized to nuclei, nucleoli, and cytoplasm, with increased label over
mitochondria. These differences in localization suggest that the HSP72 and HSP73
may associate with different proteins or complexes and hence have different but
overlapping functions in the cell.
PMID- 10681387
TI - A qualitative and quantitative study on the enkephalinergic innervation of the
pig gastrointestinal tract.
AB - Enkephalins are involved in neural control of digestive functions such as
motility, secretion, and absorption. To better understand their role in pigs, we
analyzed the qualitative and quantitative distribution of enkephalin
immunoreactivity (ENK-IR) in components of the intestinal wall from the esophagus
to the anal sphincter. Immunohistochemical labelings were analyzed using
conventional fluorescence and confocal microscopy. ENK-IR was compared with the
synaptophysin immunoreactivity (SYN-IR). The results show that maximal ENK-IR
levels in the entire digestive tract are reached in the myenteric plexuses and,
to a lesser extent, in the external submucous plexus and the circular muscle
layer. In the longitudinal muscle layer, ENK-IR was present in the esophagus,
stomach, rectum, and anal sphincter, whereas it was absent from the duodenum to
the distal colon. In the ENK-IR plexuses and muscle layers, more than 60% of the
nerve fibers identified by SYN-IR expressed ENK-IR. No ENK-IR was observed in the
internal submucous plexus and the mucosa; the latter was found to contain ENK-IR
endocrine cells. These results strongly suggest that, in pigs, enkephalins play a
major role in the regulatory mechanisms that underlie the neural control of
digestive motility.
PMID- 10681388
TI - cAMP-dependent Cl(-) channel protein (CFTR) and its mRNA are expressed in the
secretory portion of human eccrine sweat gland.
AB - Immunoreactive cystic fibrosis transport regulator (CFTR) proteins in human sweat
ducts has been documented but CFTR expression in the secretory coil has remained
uncertain. Using monoclonal antibodies (MAbs) against epitopes in the R-domain
and C-terminus, we observed the following: Formalin fixation masks the CFTR
epitopes but the epitopes are exposed by treatment with urea and heat (antigen
retrieval). Pen-Fix fixation preserves CFTR epitopes. The secretory coil also
expresses CFTR epitopes for the R-domain and C-terminus. An MAb against C
terminus amino acids 1466-1480 coupled to keyhole limpet hemocyanin (MAb WC)
stained dark cells predominantly. Staining by MAbs against the C-terminus was
completely blocked by a C-terminus peptide. mRNA for CFTR was amplified by RT-PCR
in both the duct and the secretory coil. In situ hybridization for CFTR mRNA
after 3SR amplification indicates that mRNA is localized in the dark cells and
perhaps also in the clear cell cytoplasm near the secretory coil. mRNA is present
in both the luminal and basal duct cells. We conclude that CFTR is expressed
equally well in both the duct and the secretory coil, suggesting that cAMP
dependent Cl(-) channels are involved in regulation of sweat secretion and duct
absorption.
PMID- 10681389
TI - Effect of fixation and epitope retrieval on BrdU indices in mammary carcinomas.
AB - Studies in which 5-bromo-2'-deoxyuridine (BrdU) is used to quantify rates of cell
proliferation are conducted prospectively. Therefore, the opportunity exists to
select conditions that optimize detection of the BrdU epitope. The objective of
this study was to quantify the extent to which the BrdU epitope was masked by
formalin vs methacarn fixation in the assessment of cell proliferation. Mammary
carcinomas from animals pulse-labeled with BrdU were trisected. A portion was
frozen and the remaining two portions were fixed in 10% neutral buffered formalin
or methacarn for 24 hr, processed, embedded in paraffin, and sections stained for
incorporated BrdU using a peroxidase immunohistochemical staining technique.
Antigen retrieval techniques also were applied to formalin-fixed sections.
Fixation in methacarn gave the highest labeling index (16.4%), which was
comparable to that observed in unfixed frozen sections (17.5%). Formalin fixation
alone dramatically suppressed the labeling index (0.3%), which was only partially
recovered using various antigen retrieval techniques (2.1-8.1%). Methacarn
fixation is recommended for prospective studies in which BrdU detection is
planned because of the quantitative recovery of epitope and the simplicity of the
approach.
PMID- 10681390
TI - Integrin expression during epithelial migration and restratification in the
tenascin-C-deficient mouse cornea.
AB - In the unwounded cornea, tenascin-C localizes to a short stretch of the basement
membrane zone at the corneoscleral junction or limbus. To determine whether the
function of the limbus is affected by the absence of tenascin-C, mice possessing
a deletion of tenascin-C and strain-matched wild-type mice are used in corneal
debridement wounding experiments. The expression of integrins (alpha3, alpha9,
and beta4) in the tenascin-C knockout corneas is evaluated by producing
polyclonal cytoplasmic domain antipeptide sera and performing immunofluorescence
microscopy. In addition, we evaluate the localization of several other proteins
involved in wound healing, including fibronectin, laminin beta1,
nidogen/entactin, and VCAM-1, in both the tenascin knockout and wild-type mice.
There are no differences in healing rate, scarring, or neovascularization after
corneal debridement wounds. alpha9 integrin is expressed at the limbal border of
unwounded tenascin-C knockout animals and is upregulated during migration only
after the larger wounds. At 8 weeks after larger wounds, the localization of
alpha9 again becomes restricted to the limbal border. Results show that tenascin
C is not required for development or maintenance of the corneal limbus or for
normal re-epithelialization of corneal epithelial cells after debridement
wounding.
PMID- 10681391
TI - Immunohistochemical study of the expression of MUC6 mucin and co-expression of
other secreted mucins (MUC5AC and MUC2) in human gastric carcinomas.
AB - To investigate the expression of MUC6 mucin in gastric carcinomas, we generated a
novel monoclonal antibody (MAb CLH5) using an MUC6 synthetic peptide. MAb CLH5
reacted exclusively with the MUC6 peptide and with native and deglycosylated
mucin extracts from gastric tissues. MAb CLH5 immunoreactivity was observed in
normal gastric mucosa restricted to pyloric glands of the antrum and mucopeptic
cells of the neck zone of the body region. In a series of 104 gastric carcinomas,
31 (29.8%) were immunoreactive for MUC6. The expression of MUC6 was not
associated with histomorphological type or with clinicopathological features of
the carcinomas. Analysis of the co-expression of MUC6 with other secreted mucins
(MUC5AC and MUC2) in 20 gastric carcinomas revealed that different mucin core
proteins are co-expressed in 55% of the cases. MUC6 was co-expressed and co
localized with MUC5AC in 45% and with MUC2 in 5% of the cases. Expression of MUC2
alone was observed in 25% of the cases. All carcinomas expressing MUC2 mucin in
more than 50% of the cells were of the mucinous type according to the WHO
classification. The co-expression of mucins was independent of the
histomorphological type and stage of the tumors. In conclusion, we observed,
using a novel well-characterized MAb, that MUC6 is a good marker of mucopeptic
cell differentiation and is expressed in 30% of gastric carcinomas, independent
of the clinicopathological features of the cases. Furthermore, we found that co
expression and co-localization of mucins in gastric carcinomas is independent of
histomorphology and staging. Finally, we observed that intestinal mucin MUC2 is
expressed as the most prominent mucin of the mucins tested in mucinous-type
gastric carcinomas.
PMID- 10681392
TI - Expression of prolactin mRNA in rat mammary gland during pregnancy and lactation.
AB - We studied the expression of prolactin (PRL) mRNA in the mammary gland of
resting, pregnant, lactating, and weanling rats using in situ and solution
reverse transcriptase-polymerase chain reaction (RT-PCR). In mid- to late
pregnancy and throughout lactation, PRL mRNA was detected in both in situ and
solution RT-PCR. These PRL mRNA signals were clearly identified in the cytoplasm
of alveolar and ductal mammary epithelial cells by the in situ RT-PCR method. In
mid- to late pregnancy, such as at the initiating point of PRL mRNA expression,
we confirmed in some cases a lack of PRL mRNA by solution RT-PCR. In addition, in
the early weaning phase, no signals were detected by solution RT-PCR. However,
slight focal signals were detected in some poorly vacuolated cytoplasm of
regressing acinar cells by in situ RT-PCR. These findings suggest that PRL mRNA
in rat mammary gland begins in mid- to late pregnancy in parallel with the
development of the mammary gland, continues throughout lactation, and declines in
the early phase of weaning, with regression of mammary epithelial cells.
PMID- 10681393
TI - The cadherin-catenin complex is expressed alternately with the adenomatous
polyposis coli protein during rat incisor amelogenesis.
AB - E-cadherin, a calcium-dependent cell-cell adhesion molecule, is expressed in
highly specific spatiotemporal patterns throughout metazoan development, notably
at sites of embryonic induction. E-cadherin also plays a critical role in
regulating cell motility/adhesion, cell proliferation, and apoptosis. We have
used the continuously erupting rat incisor as a system for examining the
expression of E-cadherin and the associated catenins [alpha-, beta-, gamma
catenin (plakoglobin) and p120(ctn)] during amelogenesis. Using
immunhistochemical techniques, we observed expression of alpha-catenin and gamma
catenin in ameloblasts throughout amelogenesis. In contrast, expression of E
cadherin, beta-catenin, and p120(ctn) was strong in presecretory, transitional,
and reduced stage ameloblasts (Stages I, III, and V) but was dramatically lower
in secretory and maturation stage ameloblasts (Stages II and IV). This expression
alternates with the expression pattern we previously reported for the adenomatous
polyposis coli protein (APC), a tumor suppressor that competes with E-cadherin
for binding to beta-catenin. We suggest that alternate expression of APC and the
cadherin-catenin complex is critical for the alterations in cell-cell adhesion
and other differentiated cellular characteristics, such as cytoskeletal
alterations, that are required for the formation of enamel by ameloblasts.
PMID- 10681394
TI - Acidic fibroblast growth factor is present in the enteric nervous system of the
large intestine.
AB - Acidic fibroblast growth factor (aFGF) is a heparin binding protein that displays
pleiotropic activity. The purpose of this study was to document the presence of
the translated aFGF product, its mRNA, and its location in the colon. mRNA was
extracted from bovine large intestine and reverse transcribed to cDNA. Nested
primer PCR was used to determine the presence of mRNA using primers homologous to
the previously published bovine aFGF cDNA. Purification of translated aFGF was
performed using an established HPLC protocol. Western blot analysis of the HPLC
fractions was performed using two epitope-independent antibodies against aFGF.
Immunohistochemistry employed these antibodies to determine the locus of aFGF
expression. The nested-primer PCR product of predicted size was homologous to the
published bovine aFGF mRNA sequence, as determined by DNA sequencing. Intestinal
aFGF had a mass similar to bovine aFGF isolated from other tissues, and
immunocrossreacted with two peptide-based, epitope-independent anti-aFGF antisera
on Western blotting. Immunohistochemical analysis of large intestine using these
two independent antisera localized aFGF within the myenteric plexus. These data
demonstrate that aFGF is present within the myenteric plexus of the enteric
nervous system.
PMID- 10681395
TI - Expression of glutamine synthetase in macrophages.
AB - We studied the expression of glutamine synthetase in liver macrophages (Kupffer
cells, KCs) in situ and in culture. Glutamine synthetase was detectable at the
mRNA and protein level in freshly isolated and short-term-cultured rat liver
macrophages. Enzyme activity and protein content were about 9% of that in liver
parenchymal cells. In contrast, glutamine synthetase mRNA levels in liver
macrophages apparently exceeded those in parenchymal liver cells (PCs). By use of
confocal laser scanning microscopy and specific macrophage markers,
immunoreactive glutamine synthetase was localized to macrophages in normal rat
liver and normal human liver in situ. All liver macrophages stained positive for
glutamine synthetase. In addition, macrophages in rat pancreas contained
immunoreactive glutamine synthetase, whereas glutamine synthetase was not
detectable at the mRNA and protein level in blood monocytes and RAW 264.7 mouse
macrophages. No significant amounts of glutamine synthetase were found in
isolated rat liver sinusoidal endothelial cells (SECs). The data suggest a
constitutive expression of glutamine synthetase not only, as previously believed,
in perivenous liver parenchymal cells but also in resident liver macrophages.
PMID- 10681396
TI - Immunolocalization of collagen types II and III in single fibrils of human
articular cartilage.
AB - Type II and III fibrillar collagens were localized by immunogold electron
microscopy in resin sections of human femoral articular cartilage taken from the
upper radial zone in specimens from patients with osteoarthritis. Tissue samples
stabilized by high-pressure cryofixation were processed by freeze-substitution,
either in acetone containing osmium or in methanol without chemical fixatives,
before embedding in epoxy or Lowicryl resin, respectively. Ultrastructural
preservation was superior with osmium-acetone, although it was not possible to
localize collagens by this method. In contrast, in tissue prepared by low
temperature methods without chemical fixation, collagens were successfully
localized with mono- or polyclonal antibodies to the helical (Types II and III)
and amino-propeptide (Type III procollagen) domains of the molecule. Dual
localization using secondary antibodies labeled with 5- or 10-nm gold particles
demonstrated the presence of Types II and III collagen associated within single
periodic banded fibrils. Collagen fibrils in articular cartilage are understood
to be heteropolymers mainly of Types II, IX, and XI collagen. Our observations
provide further evidence for the complexity of these assemblies, with the
potential for interactions between at least 11 distinct collagen types as well as
several noncollagenous components of the extracellular matrix.
PMID- 10681397
TI - Analysis of antiphotobleaching reagents for use with FluoroNanogold in
correlative microscopy.
AB - Correlative microscopy is an important approach for bridging the resolution gap
between fluorescence and electron microscopy. We have employed FluoroNanogold
(FNG) as the detection system in these types of studies. This immunoprobe
consists of a gold cluster compound to which a fluorochrome-labeled antibody is
covalently linked. In these preparations, the fluorescence signal from FNG is
first recorded then the gold cluster compound is subjected to a silver
enhancement reaction before examination by electron microscopy. Potential
complications are those associated with photochemical reactions that occur during
fluorescence microscopy. We have evaluated this and some anti-photobleaching
agents (i.e., 1,4-diazabicyclo[2.2.2]octane [DABCO],p-phenylenediamine [PPD], and
N-propyl gallate [NPG]) for their utility with FNG in correlative microscopy.
When DABCO was employed, the gold signal from FNG was dramatically diminished but
the fluorescence signal was unaffected. The gold signal of DABCO-treated samples
decreased to approximately 30% of that of the other samples. On the other hand,
PPD and NPG did not adversely affect the FNG labeling. We recommend that either
PPD or NPG be used and that DABCO be avoided as an antiphotobleaching reagent for
this technique.
PMID- 10681398
TI - Direct eye visualization of Cy5 fluorescence for immunocytochemistry and in situ
hybridization.
AB - Cyanine 5.18 (or Cy5) is a fluorochrome emitting in the long-red/far-red range,
usually regarded as unsuitable for direct observation by the human eye. We
describe here the optimization of a direct visualization approach to Cy5
labeling, based on a standard fluorescence microscope with mercury light
excitation and applicable to both immunocytochemistry and fluorescent in situ
hybridization. Crucial factors were (a) an excitation path in the microscope not
absorbing light in the orange-red range, up to 640 nm, (b) a 588-640-nm
excitation filter range, distinctly below the excitation optimum for Cy5, (c) a
650-700-nm emission filter range, transmitting the low-wavelength portion of Cy5
emission, and (d) high-efficiency filter set components allowing a narrow gap
between excitation and emission ranges without visible cross-talk of excitation
light in the emission path.
PMID- 10681399
TI - Cytochrome P450 and arachidonic acid bioactivation. Molecular and functional
properties of the arachidonate monooxygenase.
AB - The demonstration of in vivo arachidonic acid epoxidation and omega-hydroxylation
established the cytochrome P450 epoxygenase and omega/omega-1 hydroxylase as
formal metabolic pathways and as members of the arachidonate metabolic cascade.
The characterization of the potent biological activities associated with several
of the cytochrome P450-derived eicosanoids suggested new and important functional
roles for these enzymes in cellular, organ, and body physiology, including the
control of vascular reactivity and systemic blood pressures. Past and current
advances in cytochrome P450 biochemistry and molecular biology facilitate the
characterization of cytochrome P450 isoforms responsible for tissue/organ
specific arachidonic acid epoxidation and omega/omega-1 hydroxylation, and thus,
the analysis of cDNA and/or gene specific functional phenotypes. The combined
application of physiological, biochemical, molecular, and genetic approaches is
beginning to provide new insights into the physiological and/or
pathophysiological significance of these enzymes, their endogenous substrates,
and products.
PMID- 10681400
TI - n-3 PUFA dietary supplementation inhibits proliferation and store-operated
calcium influx in thymoma cells growing in Balb/c mice.
AB - The antitumor effect of daily individual administration of eicosapentaenoic acid
(EPA) and docosahexaenoic acid (DHA) (2 g/kg body weight) in Balb/c mice bearing
a transplantable thymoma was investigated. Mice received oleic acid (control
group), EPA and DHA ethyl esters starting 10 days before tumor inoculation.
Analysis of phospholipid composition of neoplastic cell revealed that EPA and DHA
levels were significantly increased (63 and 22% increase) after EPA and DHA
treatments, respectively. Conversely, decreased levels of arachidonic acid were
found in both cases (19 and 24% decrease in EPA and DHA groups, respectively).
EPA and DHA delayed the appearance of macroscopic ascites (100% of animal, from 7
to 28 days), prolonged animal survival (100% of animal, from 22 to 32 and 33
days, respectively) and reduced the percentage of proliferating tumor cells
detected by immunostaining of proliferation cell nuclear antigen (PCNA) (80 and
85% decrease, respectively). Moreover, the regulatory effects of these dietary n;
3 fatty acids on the influx of Ca(2+), activated by depletion of intracellular
stores with thapsigargin (Tg), were investigated. By using a Ca(2+)-free/Ca(2+)
reintroduction protocol and Fura-2 as fluorescent indicator of intracellular free
Ca(2+)([Ca(2+)](i)), we observed that EPA and DHA treatments markedly decreased
Tg-induced rise in [Ca(2+)](i) (49 and 37% decrease, respectively). This effect
was related to the inhibition of the store-operated Ca(2+) influx, as confirmed
also by Mn(2+) influx experiments. The inhibitory action of EPA and DHA on the
store-operated Ca(2+) influx could explain, at least in part, their antitumoral
activity, as this Ca(2+) mobilization pathway appears to be involved in the cell
signaling occurring in non-excitable cells to evoke many cellular processes,
including cell proliferation.
PMID- 10681401
TI - Measurement of cholesterol gallstone growth in vitro.
AB - Methods to study growth of gallstones in the laboratory have not been reported.
We here present such a method. Human cholesterol gallstones were harvested from
patients with multiple nearly identical stones. The gallstones were washed and
added to supersaturated model biles and the formation of cholesterol crystals and
the increases in mass of human cholesterol gallstones were studied concurrently,
over a period of weeks, using nephelometry and a microbalance, respectively. All
stones incubated in model biles supersaturated with cholesterol increased in
mass. Increases in the degree of supersaturation of cholesterol in the model
biles resulted in increased growth of stones. The mass increases, the growth
rates, and the spatial orientation of accreted crystalline cholesterol differed
among various stone types. The kinetics and structures of stone growth were
similar when the stones were incubated in supersaturated, native, human
gallbladder biles. The structure of accreted cholesterol was the same as found on
the surface of some human gallstones that were harvested during apparent active
growth in situ. This simple method allows accurate measurements of stone growth
in vitro, in patterns that mimic stone growth in vivo, and is useful for studies
on the relationships of gallstone growth and the kinetics of cholesterol
crystallization.
PMID- 10681402
TI - Plasma 24S-hydroxycholesterol (cerebrosterol) is increased in Alzheimer and
vascular demented patients.
AB - Alzheimer's disease (AD) is characterized by the presence of senile plaques,
neurofibrillary tangles, and neuronal cell loss associated with membrane
cholesterol release. 24S-hydroxycholesterol (24S-OH-Chol) is an enzymatically
oxidized product of cholesterol mainly synthesized in the brain. We tested the
hypothesis that plasma levels of this oxysterol could be used as a putative
biochemical marker for an altered cholesterol homeostasis in the brain of AD
patients. Thirty patients with clinical criteria for AD, 30 healthy volunteers,
18 depressed patients, and 12 patients with vascular dementia (non-Alzheimer
demented) were studied. Plasma concentrations of 24S-OH-Chol were assayed by
isotope dilution;-mass spectrometry, cholesterol was measured enzymatically, and
apolipoprotein E (apoE) was genotyped by polymerase chain reaction and restricted
fragment length polymorphism. The concentration of 24S-OH-Chol in AD and non
Alzheimer demented patients was modestly but significantly higher than in healthy
controls and in depressed patients. There was no significant difference in the
concentrations of 24S-OH-Chol between depressed patients and healthy controls nor
between AD and non-Alzheimer demented patients. The apoE straightepsilon4 allele
influences plasma 24S-OH-Chol. However, this influence could be completely
accounted for by the elevated plasma cholesterol in apoE4 hetero- or homozygotes.
Plasma 24S-OH-Chol levels correlated negatively with the severity of dementia. AD
and vascular demented patients appear to have higher circulating levels of 24S-OH
Chol than depressed patients and healthy controls. We speculate that 24S-OH-Chol
plasma levels may potentially be used as an early biochemical marker for an
altered cholesterol homeostasis in the central nervous system. 24S
hydroxycholesterol (cerebrosterol) is increased in Alzheimer and vascular
demented patients.
PMID- 10681403
TI - Mechanism of the stimulatory action of okadaic acid on lipolysis in rat fat
cells.
AB - Okadaic acid was found to induce concentration- and time-dependent lipolysis in
rat fat cells in the absence of lipolytic hormones, but it did not significantly
increase the total hormone-sensitive lipase (HSL) activity in these fat cells,
the activity of HSL extracted from fat layer and that of HSL in the supernatant
of homogenized fat cells. Western blotting of fat cell homogenate fractions with
an antiserum raised against synthetic peptide derived from rat HSL showed that
HSL protein shifted from the supernatant to the fat layer in response to okadaic
acid, which increased the HSL protein content on the fat layer and concomitantly
reduced that of the supernatant, concentration- and time-dependently. Sonication
of the fat cells abolished their responsiveness to okadaic acid. The lipolytic
action of okadaic acid was examined and its site was identified using a cell-free
system comprising lipid droplets isolated from rat fat cells and HSL. Okadaic
acid induced lipolysis in this cell-free system and sonication of the lipid
droplets caused disappearance of lipolytic action of okadaic acid. Okadaic acid
failed to stimulate lipolysis in a cell-free system comprising HSL and artificial
lipid droplets (trioleoylglycerol emulsified with gum arabic) instead of lipid
droplets isolated from rat fat cells. These results suggest that okadaic acid
does not increase the catalytic activity of HSL but induces translocation of HSL
to the lipid droplets isolated from rat fat cells. The site of the lipolytic
action of okadaic acid in relation to the interaction between HSL and lipid
droplet is discussed.
PMID- 10681404
TI - Relative roles of LDLr and LRP in the metabolism of chylomicron remnants in
genetically manipulated mice.
AB - Remnant-like emulsions labeled with cholesteryl [(13)C]-oleate were prepared with
lipid compositions similar to remnants derived from triacylglycerol-rich
lipoproteins. When injected into the bloodstream of conscious mice, the remnant
like emulsions were metabolized in the liver leading to the appearance of
(13)CO(2) in the breath. Previously, using this technique, we found that remnant
metabolism was significantly impaired but not completely inhibited in mice
lacking low density lipoprotein receptors (LDLr). We have now found in mice with
non-functional low density lipoprotein receptor-related protein (LRP) that breath
enrichment of (13)CO(2) was significantly decreased, indicating that the LRP also
plays an important role in the metabolism of chylomicron remnants (CR). The
enrichment of (13)CO(2) in the expired breath was negligible in mice lacking both
LDLr and receptor-associated protein (-/-), essential for normal function of LRP.
In mice pre-injected with gluthatione S-transferase-receptor-associated protein
to block LRP binding, there was a marked inhibition of the appearance of
(13)CO(2) in the expired breath of homozygous LDLr-deficient mice, supporting the
role of LRP in vivo. Whether or not LDLr were present, in mouse and human
fibroblast cells human apoE3 or E4 but not apoE2 were essential for binding of
remnant-like emulsions, while lactoferrin and suramin completely inhibited
binding. We conclude that in normal mice LDLr are important for the physiological
metabolism of CR. When LDLr are absent the evidence supports a role for the LRP
in the uptake of CR in liver cells and in fibroblasts, with binding
characteristics for CR-associated apoE similar to LDLr.
PMID- 10681405
TI - Adrenal and liver in normal and cld/cld mice synthesize and secrete hepatic
lipase, but the lipase is inactive in cld/cld mice.
AB - Combined lipase deficiency (cld) is a recessive mutation in mice that causes a
severe lack of lipoprotein lipase (LPL) and hepatic lipase (HL) activities,
hyperlipemia, and death within 3 days after birth. Earlier studies showed that
inactive LPL and HL were synthesized by cld/cld tissues and that LPL synthesized
by cld/cld brown adipocytes was retained in their ER. We report here a study of
HL in liver, adrenal, and plasma of normal newborn and cld/cld mice.
Immunofluorescence studies showed HL was present in extracellular space, but not
in cells, in liver and adrenal of both normal and cld/cld mice. When protein
secretion was blocked with monensin, HL was retained intracellularly in liver
cell cultures and in incubated adrenal tissues of both groups of mice. These
findings demonstrated that HL was synthesized and secreted by liver and adrenal
cells in normal newborn and cld/cld mice. HL activities in liver, adrenal, and
plasma in cld/cld mice were very low, <8% of that in normal newborn mice,
indicating that HL synthesized and secreted by cld/cld cells was inactive. Livers
of both normal newborn and cld/cld mice synthesized LPL, but the level of LPL
activity in cld/cld liver was very low, <9% of that in normal liver.
Immunofluorescence studies showed that LPL was present intracellularly in liver
of cld/cld mice, indicating that LPL was synthesized but not secreted by cld/cld
liver cells. Immunofluorescent LPL was not found in normal newborn liver cells
unless the cells were treated with monensin, thus demonstrating that normal liver
cells synthesized and secreted LPL. Livers of both groups of mice contained an
unidentified alkaline lipase activity which accounted for 34-54% of alkaline
lipase activity in normal and 65% of that in cld/cld livers. Our findings
indicate that liver and adrenal cells synthesized and secreted HL in both normal
newborn and cld/cld mice, but the lipase was inactive in cld/cld mice. That
cld/cld liver cells secreted inactive HL while retaining inactive LPL indicates
that these closely related lipases were processed differently.
PMID- 10681406
TI - Cholesterol and oxysterol metabolism and subcellular distribution in macrophage
foam cells. Accumulation of oxidized esters in lysosomes.
AB - Cholesterol- and cholesteryl ester-rich macrophage foam cells, characteristic of
atherosclerotic lesions, are often generated in vitro using oxidized low density
lipoprotein (OxLDL). However, relatively little is known of the nature and extent
of sterol deposition in these cells or of its relationship to the foam cells
formed in atherosclerotic lesions. The purpose of this study was to examine the
content and cellular processing of sterols in OxLDL-loaded macrophages, and to
compare this with macrophages loaded with acetylated LDL (AcLDL; cholesteryl
ester-loaded cells containing no oxidized lipids) or 7-ketocholesterol-enriched
acetylated LDL (7KCAcLDL; cholesteryl ester-loaded cells selectively supplemented
with 7-ketocholesterol (7KC), the major oxysterol present in OxLDL). Both
cholesterol and 7KC and their esters were measured in macrophages after uptake of
these modified lipoproteins. Oxysterols comprised up to 50% of total sterol
content of OxLDL-loaded cells. Unesterified 7KC and cholesterol partitioned into
cell membranes, with no evidence of retention of either free sterol within
lysosomes. The cells also contained cytosolic, ACAT-derived, cholesteryl and 7
ketocholesteryl esters. The proportion of free cholesterol and 7KC esterified by
ACAT was 10-fold less in OxLDL-loaded cells than in AcLDL or 7KCAcLDL-loaded
cells. This poor esterification rate in OxLDL-loaded cells was partly caused by
fatty acid limitation. OxLDL-loaded macrophages also contained large
(approximately 40-50% total cell sterol content) pools of oxidized esters,
containing cholesterol or 7KC esterified to oxidized fatty acids. These were
insensitive to ACAT inhibition, very stable and located in lysosomes, indicating
resistance to lysosomal esterases. Macrophages loaded with OxLDL do not
accumulate free sterols in their lysosomal compartment, but do accumulate
lysosomal deposits of OxLDL-derived cholesterol and 7-ketocholesterol esterified
to oxidized fatty acids. The presence of similar deposits in lesion foam cells
would represent a pool of sterols that is particularly resistant to removal.
PMID- 10681407
TI - PLTP activity in premenopausal women. Relationship with lipoprotein lipase, HDL,
LDL, body fat, and insulin resistance.
AB - Plasma phospholipid transfer protein (PLTP) is thought to play a major role in
the facilitated transfer of phospholipids between lipoproteins and in the
modulation of high density lipoprotein (HDL) particle size and composition.
However, little has been reported concerning the relationships of PLTP with
plasma lipoprotein parameters, lipolytic enzymes, body fat distribution, insulin,
and glucose in normolipidemic individuals, particularly females. In the present
study, 50 normolipidemic healthy premenopausal females were investigated. The
relationships between the plasma PLTP activity and selected variables were
assessed. PLTP activity was significantly and positively correlated with low
density lipoprotein (LDL) cholesterol (r(s) = 0.53), apoB (r(s) = 0.44), glucose
(r(s) = 0.40), HDL cholesterol (r(s) = 0.38), HDL(3) cholesterol (r(s) = 0.37),
lipoprotein lipase activity (r(s) = 0.36), insulin (r(s) = 0.33), subcutaneous
abdominal fat (r(s) = 0.36), intra-abdominal fat (r(s) = 0.29), and body mass
index (r(s) = 0.29). HDL(2) cholesterol, triglyceride, and hepatic lipase were
not significantly related to PLTP activity. As HDL(2) can be decreased by hepatic
lipase and hepatic lipase is increased in obesity with increasing intra-abdominal
fat, the participants were divided into sub-groups of non-obese (n = 35) and
obese (n = 15) individuals and the correlation of PLTP with HDL(2) cholesterol
was re-examined. In the non-obese subjects, HDL(2) cholesterol was found to be
significantly and positively related to PLTP activity (r(s) = 0.44). Adjustment
of the HDL(2) values for the effect of hepatic lipase activity resulted in a
significant positive correlation between PLTP and HDL(2) (r(s) = 0.41),
indicating that the strength of the relationship between PLTP activity and HDL(2)
can be reduced by the opposing effect of hepatic lipase on HDL(2) concentrations.
We conclude that PLTP-facilitated lipid transfer activity is related to HDL and
LDL metabolism, as well as lipoprotein lipase activity, adiposity, and insulin
resistance.
PMID- 10681408
TI - Contribution of the hepatic lipase gene to the atherogenic lipoprotein phenotype
in familial combined hyperlipidemia.
AB - Familial combined hyperlipidemia (FCH) is a common genetic lipid disorder with a
frequency of 1-2% in the population. In addition to the hypercholesterolemia
and/or hypertriglyceridemia that affected individuals exhibit, small, dense LDL
particles and decreased HDL-cholesterol levels are traits frequently associated
with FCH. Recently, we reported that families with FCH and families enriched for
coronary artery disease (CAD) share genetic determinants for the atherogenic
lipoprotein phenotype (ALP), a profile presenting with small, dense LDL
particles, decreased HDL-cholesterol levels, and increased triglyceride levels.
Other studies in normolipidemic populations have shown that the hepatic lipase
(HL) gene is linked to HDL-cholesterol levels and that a polymorphism within the
HL promoter (-514C-->T) is associated with increased HDL-cholesterol levels as
well as larger, more buoyant LDL particles. In the present study, we tested
whether the HL gene locus also contributes to ALP in a series of Dutch FCH
families using nonparametric sibpair linkage analysis and association analysis.
Evidence for linkage of LDL particle size (P < 0.019), HDL-cholesterol (P <
0.003), and triglyceride levels (P < 0.026) to the HL gene locus was observed. A
genome scan in a subset of these families exhibited evidence for linkage of PPD
(LOD = 2.2) and HDL-cholesterol levels (LOD = 1.2) to the HL gene locus as well.
The -514C-->T promoter polymorphism was significantly associated (P < 0.0001)
with higher HDL-cholesterol levels in the unrelated males of this population, but
not in unrelated females. No association was observed between the polymorphism
and LDL particle size or triglyceride levels. Our results provide support that
ALP is a multigenic trait and suggest that the relationship between small, dense
LDL particles, HDL-cholesterol, and triglyceride levels in FCH families is due,
in part, to common genetic factors.
PMID- 10681409
TI - Markedly increased secretion of VLDL triglycerides induced by gene transfer of
apolipoprotein E isoforms in apoE-deficient mice.
AB - Apolipoprotein E (apoE) plays a key role in the receptor-mediated uptake of
lipoproteins by the liver and therefore in regulating plasma levels of
lipoproteins. ApoE may also facilitate hepatic secretion of very low density
lipoprotein (VLDL) triglyceride (TG). We directly tested the hypothesis that
reconstitution of hepatic apoE expression in adult apoE-deficient mice by gene
transfer would acutely enhance VLDL-TG production and directly compared the three
major human apoE isoforms using this approach. Second generation recombinant
adenoviruses encoding the three major isoforms of human apoE (E2, E3, and E4) or
a control virus were injected intravenously into apoE-deficient mice, resulting
in acute expression of the apoE isoforms in the liver. Despite the expected
decreases in total and VLDL cholesterol levels, apoE expression was associated
with increased total and VLDL triglyceride levels (E2 > E4 > E3). The increase in
TG levels significantly correlated with plasma apoE concentrations. In order to
determine whether acute apoE expression influenced the rate of VLDL-TG
production, additional experiments were performed. Three days after injection of
adenoviruses, Triton WR1339 was injected to block lipolysis of TG-rich
lipoproteins and VLDL-TG production rates were determined. Mice injected with
control adenovirus had a mean VLDL-TG production rate of 74 +/- 7 micromol/h/kg.
In contrast, VLDL-TG production rates in apoE-expressing mice were 363 +/- 162
micromol/h/kg, 286 +/- 175 micromol/h/kg, and 300 +/- 84 micromol/h/kg for apoE2,
apoE3, and apoE4, respectively. The VLDL-TG production rates in apoE-expressing
mice were all significantly greater than in control mice but were not
significantly different from each other. In summary, acute expression of all
three human apoE isoforms in livers of apoE-deficient mice markedly increased
VLDL-TG production to a similar degree, consistent with the concept that apoE
plays an important role in facilitating hepatic VLDL-TG production in an isoform
independent manner.
PMID- 10681410
TI - Binding of hepatic lipase to heparin. Identification of specific heparin-binding
residues in two distinct positive charge clusters.
AB - The interaction of hepatic lipase (HL) with heparan sulfate is critical to the
function of this enzyme. The primary amino acid sequence of HL was compared to
that of lipoprotein lipase (LPL), a related enzyme that possesses several
putative heparin-binding domains. Of the three putative heparin-binding clusters
of LPL (J. Biol. Chem. 1994. 269: 4626-4633; J. Lipid Res. 1998. 39: 1310-1315),
one was conserved in HL (Cluster 1; residues Lys 297-Arg 300 in rat HL) and two
were partially conserved (Cluster 2; residues Asp 307-Phe 320, and Cluster 4;
residues Lys 337, and Thr 432-Arg 443). Mutants of HL were generated in which
potential heparin-binding residues within Clusters 1 and 4 were changed to Asn.
Two chimeras in which the LPL heparin-binding sequences of Clusters 2 and 4 were
substituted for the analogous HL sequences were also constructed. These mutants
were expressed in Chinese hamster ovary (CHO) cells and assayed for heparin
binding ability using heparin-Sepharose chromatography and a CHO cell-binding
assay. The results suggest that residues within the homologous Cluster 1 region
(Lys 297, Lys 298, and Arg 300), as well as some residues in the partially
conserved Cluster 4 region (Lys 337, Lys 436, and Arg 443), are involved in the
heparin binding of hepatic lipase. In the cell-binding assay, heparan sulfate
binding affinity equal to that of LPL was seen for the RHL chimera mutant that
possessed the Cluster 4 sequence of LPL. Mutation of Cluster 1 residues of HL
resulted in a major reduction in heparin binding ability as seen in both the cell
binding assay and the heparin-Sepharose elution profile. These results suggest
that Cluster 1, the N-terminal heparin-binding domain, is of primary significance
in RHL. This is different for LPL: mutations in the C-terminal binding domain
(Cluster 4) cause a more significant shift in the salt required for elution from
heparin-Sepharose than mutations in the N-terminal domain (Cluster 1).
PMID- 10681411
TI - Phospholipid transfer protein gene knock-out mice have low high density
lipoprotein levels, due to hypercatabolism, and accumulate apoA-IV-rich lamellar
lipoproteins.
AB - Phospholipid transfer protein gene knock-out (Pltp KO) mice have defective
transfer of very low density lipoprotein (VLDL) phospholipids into high density
lipoprotein (HDL) and markedly decreased HDL levels (Jiang et al. 1999. J. Clin.
Invest. 103: 907-914). These animals also accumulated VLDL- and LDL-sized
lipoproteins on a high saturated fat diet. The goals of this study were to
further characterize the abnormal lipoproteins of Pltp KO mice and to determine
the mechanisms responsible for low HDL levels. A lipoprotein fraction enriched in
lamellar structures was isolated from the low density lipoprotein (LDL) region
and was shown to be phospholipid- and free cholesterol-rich and to have apoA-IV
(55%) and apoE (25%) as major apolipoproteins. The lamellar lipoproteins
accumulating in these mice probably represent surface material derived from
triglyceride-rich lipoproteins (TRL). The HDL was found to be protein-rich
(primarily apoA-I) and specifically depleted in phosphatidylcholine (PC) (28% in
wild-type mice (WT) vs. 15% in Pltp KO mice, P < 0.001). Unexpectedly, turnover
studies using autologous HDL revealed a profound 4-fold increase in the
catabolism of HDL protein and cholesteryl ester in Pltp KO mice compared to wild
type, with minor differences in synthesis rates. In contrast, injection of WT
mouse HDL into Pltp KO mice showed only a 2-fold increase in fractional
catabolism. Reminiscent of the defect in Tangier disease, the failure of transfer
of PC from TRL into the HDL fraction results in dramatic hypercatabolism of HDL.
These results suggest that defective phospholipid transfer from TRL into HDL,
arising from decreased lipolysis or decreased PLTP activity, could lead to
hypoalphalipoproteinemia characterized by hypercatabolism of HDL protein.
lipoprotein levels, due to hypercatabolism, and accumulate apoA-IV-rich lamellar
lipoproteins.
PMID- 10681412
TI - Regulation of calcium signalling by docosahexaenoic acid in human T-cells.
Implication of CRAC channels.
AB - We elucidated the role of docosahexaenoic acid (DHA) on the increases in free
intracellular calcium concentrations, [Ca(2+)]i, in human (Jurkat) T-cell lines.
DHA evoked an increase in [Ca(2+)]i in a dose-dependent manner in these cells.
Anti-CD3 antibody, known to stimulate increases in Ca(2+) from endoplasmic
reticulum (ER) via the production of inositol trisphosphate, also evoked
increases in [Ca(2+)]i in Jurkat T-cells. We also used thapsigargin which
inhibits Ca(2+)-ATPase of the ER and, therefore, increases Ca(2+) in the cytosol.
Interestingly, addition of DHA during the thapsigargin-induced peak response
exerted an additive effect on the increases in [Ca(2+)]i in human T-cells,
indicating that the mechanisms of action of these two agents are different.
However, the DHA-induced calcium response was not observed when this agent was
added during the anti-CD3-induced calcium peak, though its addition resulted in a
prolonged and sustained calcium response as a function of time, suggesting that
DHA recruits calcium, in part, from the ER pool and the prolonged response may be
due to Ca(2+) influx. In the medium containing 0% Ca(2+), the DHA-evoked response
on the increases in [Ca(2+)]i was significantly curtailed as compared to that in
100% Ca(2+) medium, supporting the notion that the response of the DHA is also
due, in part, to the opening of calcium channels. Furthermore, preincubation of
cells with tyrphostin A9, an inhibitor of Ca(2+) release-activated Ca(2+) (CRAC)
channels also significantly curtailed the DHA-induced sustained response on the
increases in [Ca(2+)]i in these cells. These results suggest that DHA induces an
increase in [Ca(2+)]i via the ER pool and the opening of CRAC channels in human T
cells.
PMID- 10681413
TI - Lipolytic remnants of human VLDL produced in vitro. Effect of HDL levels in the
lipolysis mixtures on the apoCs to apoE ratio and metabolic properties of VLDL
core remnants.
AB - To determine the role of high-density lipoprotein (HDL) as an acceptor of
lipolytic surface remnants of very low density lipoprotein (VLDL) in the
metabolism of VLDL core remnants, we examined the effect of HDL levels in the
VLDL lipolysis mixture on 1) the morphology and the apoCs to E ratio in VLDL core
remnants and 2) the metabolic properties of VLDL core remnants in human hepatoma
cell line HepG2 and human hepatocytes in the primary culture. Normolipidemic VLDL
was lipolyzed in vitro by purified bovine milk lipoprotein lipase (LpL) in a
lipolysis mixture containing a physiologic level of VLDL and albumin (30 mg VLDL
cholesterol (CH)/dl and 6% albumin) in the absence and presence of either a low
HDL level (VLDL-CH:HDL-CH = 3:1) or a high HDL level (VLDL-CH:HDL-CH = 1:4).
Lipolysis of VLDL in either the absence or presence of HDL resulted in the
hydrolysis of >85% of VLDL-triglycerides (TG) and the conversion of VLDL into
smaller and denser particles. In the absence of HDL, heterogeneous spherical
particles with numerous surface vesicular materials were produced. In the
presence of low or high HDL, spherical particles containing some or no detectable
vesicular surface components were produced. The apoCs to apoE ratios, as
determined by densitometric scanning of the SDS polyacrylamide gradient gel, were
2.89 in control VLDL and 2.27, 0.91, and 0.22 in VLDL core remnants produced in
the absence and in the presence of low and high HDL levels, respectively. In
vitro lipolysis of VLDL markedly increased binding to HepG2 cells at 4 degrees C
and internalization and degradation by human hepatocytes in primary culture at 37
degrees C. However, the HDL-mediated decrease in the apoCs to apoE ratio had a
minimal effect on binding, internalization, and degradation of VLDL core remnants
by HepG2 cells and human hepatocytes in primary culture. In order to determine
whether HepG2 bound VLDL and VLDL core remnants are deficient in apoCs, (125)I
labeled VLDL and VLDL core remnants were added to HepG2 culture medium at 4
degrees C. The bound particles were released by heparin, and the levels of (125)I
labeled apoCs and apoE, relative to apoB, in the released particles were
examined. When compared with those initially added to culture medium, the VLDL
and VLDL core remnants released from HepG2 cells had a markedly increased (113%)
level of apoE and a reduced (30-39%), but not absent, level of apoCs. We conclude
that apoCs, as a minimum structural and/or functional component of VLDL and VLDL
core remnants, may not have an inhibitory effect on the binding of VLDL or VLDL
core remnants to hepatic apoE receptors.
PMID- 10681414
TI - Ileal bile acid transport regulates bile acid pool, synthesis, and plasma
cholesterol levels differently in cholesterol-fed rats and rabbits.
AB - We investigated the effect of ileal bile acid transport on the regulation of
classic and alternative bile acid synthesis in cholesterol-fed rats and rabbits.
Bile acid pool sizes, fecal bile acid outputs (synthesis rates), and the
activities of cholesterol 7alpha-hydroxylase (classic bile acid synthesis) and
cholesterol 27-hydroxylase (alternative bile acid synthesis) were related to
ileal bile acid transporter expression (ileal apical sodium-dependent bile acid
transporter, ASBT). Plasma cholesterol levels rose 2.1-times in rats (98 +/- 19
mg/dl) and 31-times (986 +/- 188 mg/dl) in rabbits. The bile acid pool size
remained constant (55 +/- 17 mg vs. 61 +/- 18 mg) in rats but doubled (254 +/- 46
to 533 +/- 53 mg) in rabbits. ASBT protein expression did not change in rats but
rose 31% (P < 0.05) in rabbits. Fecal bile acid outputs that reflected bile acid
synthesis increased 2- and 2.4-times (P < 0.05) in cholesterol-fed rats and
rabbits, respectively. Cholesterol 7alpha-hydroxylase activity rose 33% (24 +/-
2.4 vs. 18 +/- 1.6 pmol/mg/min, P < 0.01) and mRNA levels increased 50% (P <
0.01) in rats but decreased 68% and 79%, respectively, in cholesterol-fed
rabbits. Cholesterol 27-hydroxylase activity remained unchanged in rats but rose
62% (P < 0.05) in rabbits. Classic bile acid synthesis (cholesterol 7alpha
hydroxylase) was inhibited in rabbits because an enlarged bile acid pool
developed from enhanced ileal bile acid transport. In contrast, in rats,
cholesterol 7alpha-hydroxylase was stimulated but the bile acid pool did not
enlarge because ASBT did not change. Therefore, although bile acid synthesis was
increased via different pathways in rats and rabbits, enhanced ileal bile acid
transport was critical for enlarging the bile acid pool size that exerted
feedback regulation on cholesterol 7alpha-hydroxylase in rabbits.
PMID- 10681415
TI - Apolipoprotein B metabolism and the distribution of VLDL and LDL subfractions.
AB - Apolipoprotein B (apoB) metabolism was investigated in 20 men with plasma
triglyceride 0.66-2.40 mmol/l and plasma cholesterol 3.95-6. 95 mmol/l. Kinetics
of VLDL(1) (S(f) 60-400), VLDL(2) (S(f) 20-60), IDL (S(f) 12-20), and LDL (S(f)
0;-12) apoB were analyzed using a trideuterated leucine tracer and a
multicompartmental model which allowed input into each fraction. VLDL(1) apoB
production varied widely (from 5.4 to 26.6 mg/kg/d) as did VLDL(2) apoB
production (from 0.18 to 8.4 mg/kg/d) but the two were not correlated. IDL plus
LDL apoB direct production accounted for up to half of total apoB production and
was inversely related to plasma triglyceride (r = -0.54, P = 0.009). Percent of
direct apoB production into the IDL/LDL density range (r = 0.50, P < 0.02) was
positively related to the LDL apoB fractional catabolic rate (FCR). Plasma
triglyceride in these subjects was determined principally by VLDL(1) and VLDL(2)
apoB fractional transfer rates (FTR), i.e., lipolysis. IDL apoB concentration was
regulated mainly by the IDL to LDL FTR (r = -0.71, P < 0.0001). LDL apoB
concentration correlated with VLDL(2) apoB production (r = 0.48, P = 0.018) and
the LDL FCR (r = -0.77, P < 0. 001) but not with VLDL(1), IDL, or LDL apoB
production. Subjects with predominantly small, dense LDL (pattern B) had lower
VLDL(1) and VLDL(2) apoB FTRs, higher VLDL(2) apoB production, and a lower LDL
apoB FCR than those with large LDL (pattern A). Thus, the metabolic conditions
that favored appearance of small, dense LDL were diminished lipolysis of VLDL,
resulting in a raised plasma triglyceride above the putative threshold of 1.5
mmol/l, and a prolonged residence time for LDL. This latter condition presumably
permitted sufficient time for the processes of lipid exchange and lipolysis to
generate small LDL particles.
PMID- 10681417
TI - Anatomy of a proficient enzyme: the structure of orotidine 5'-monophosphate
decarboxylase in the presence and absence of a potential transition state analog.
AB - Orotidine 5'-phosphate decarboxylase produces the largest rate enhancement that
has been reported for any enzyme. The crystal structure of the recombinant
Saccharomyces cerevisiae enzyme has been determined in the absence and presence
of the proposed transition state analog 6-hydroxyuridine 5'-phosphate, at a
resolution of 2.1 A and 2.4 A, respectively. Orotidine 5'-phosphate decarboxylase
folds as a TIM-barrel with the ligand binding site near the open end of the
barrel. The binding of 6-hydroxyuridine 5'-phosphate is accompanied by protein
loop movements that envelop the ligand almost completely, forming numerous
favorable interactions with the phosphoryl group, the ribofuranosyl group, and
the pyrimidine ring. Lysine-93 appears to be anchored in such a way as to
optimize electrostatic interactions with developing negative charge at C-6 of the
pyrimidine ring, and to donate the proton that replaces the carboxylate group at
C-6 of the product. In addition, H-bonds from the active site to O-2 and O-4 help
to delocalize negative charge in the transition state. Interactions between the
enzyme and the phosphoribosyl group anchor the pyrimidine within the active site,
helping to explain the phosphoribosyl group's remarkably large contribution to
catalysis despite its distance from the site of decarboxylation.
PMID- 10681418
TI - Induction of a bystander mutagenic effect of alpha particles in mammalian cells.
AB - Ever since the discovery of X-rays was made by Rontgen more than a hundred years
ago, it has always been accepted that the deleterious effects of ionizing
radiation such as mutation and carcinogenesis are attributable mainly to direct
damage to DNA. Although evidence based on microdosimetric estimation in support
of a bystander effect appears to be consistent, direct proof of such
extranuclear/extracellular effects are limited. Using a precision charged
particle microbeam, we show here that irradiation of 20% of randomly selected
A(L) cells with 20 alpha particles each results in a mutant fraction that is 3
fold higher than expected, assuming no bystander modulation effect. Furthermore,
analysis by multiplex PCR shows that the types of mutants induced are
significantly different from those of spontaneous origin. Pretreatment of cells
with the radical scavenger DMSO had no effect on the mutagenic incidence. In
contrast, cells pretreated with a 40 microM dose of lindane, which inhibits cell
cell communication, significantly decreased the mutant yield. The doses of DMSO
and lindane used in these experiments are nontoxic and nonmutagenic. We further
examined the mutagenic yield when 5-10% of randomly selected cells were
irradiated with 20 alpha particles each. Results showed, likewise, a higher
mutant yield than expected assuming no bystander effects. Our studies provide
clear evidence that irradiated cells can induce a bystander mutagenic response in
neighboring cells not directly traversed by alpha particles and that cell-cell
communication process play a critical role in mediating the bystander phenomenon.
PMID- 10681419
TI - Secretory responses of intact glomus cells in thin slices of rat carotid body to
hypoxia and tetraethylammonium.
AB - We have developed a thin-slice preparation of whole rat carotid body that allows
us to perform patch-clamp recording of membrane ionic currents and to monitor
catecholamine secretion by amperometry in single glomus cells under direct visual
control. In normoxic conditions (P(O(2)) approximately 140 mmHg; 1 mmHg = 133
Pa), most glomus cells did not have measurable secretory activity, but exposure
to hypoxia (P(O(2)) approximately 20 mmHg) elicited the appearance of a large
number of spike-like exocytotic events. This neurosecretory response to hypoxia
was fully reversible and required extracellular Ca(2+) influx. The average charge
of single quantal events was 46 +/- 25 fC (n = 218), which yields an estimate of
approximately 140,000 catecholamine molecules per vesicle. Addition of
tetraethylammonium (TEA; 2-5 mM) to the extracellular solution induced in most
(>95%) cells tested (n = 32) a secretory response similar to that elicited by low
P(O(2)). Cells nonresponsive to hypoxia but activated by exposure to high
external K(+) were also stimulated by TEA. A secretory response similar to the
responses to hypoxia and TEA was also observed after treatment of the cells with
iberiotoxin to block selectively Ca(2+)- and voltage-activated maxi-K(+)
channels. Our data further show that membrane ion channels are critically
involved in sensory transduction in the carotid body. We also show that in intact
glomus cells inhibition of voltage-dependent K(+) channels can contribute to
initiation of the secretory response to low P(O(2)).
PMID- 10681420
TI - A library of bacteriophage-displayed antibody fragments directed against proteins
of the inner ear.
AB - Bacteriophage display of antibodies provides a method for the generation of
immunological reagents against rare and uncharacterized antigens. To ascertain
the usefulness of this approach for the characterization of inner-ear proteins,
we produced a bacteriophage-displayed antibody-fragment library directed against
proteins from the bullfrog's sacculus. This library was probed for bacteriophage
that bound to proteins present in a lysate of hair cells, the sensory receptors
of the inner ear. The predominant bacteriophage clone after selection expressed
an antibody fragment that recognized a single protein in the inner ear. This
antigen occurred in both the nonsensory and sensory epithelia of the sacculus.
The specificity of the antibody fragment indicates that our bacteriophage
displayed library provides a useful source of immunological tools that should
facilitate the identification and biochemical characterization of novel proteins
in the inner ear.
PMID- 10681421
TI - Localized neuronal activation in the zebra finch brain is related to the strength
of song learning.
AB - Songbirds (Oscines) learn their songs from a tutor. It is not known where in the
brain the memories of these learned sounds are stored. Recent evidence suggests
that song perception in songbirds involves neuronal activation in brain regions
that have not traditionally been implicated in the control of song production or
song learning, notably the caudal part of the neostriatum (NCM) and of the
hyperstriatum ventrale. Zebra finch males (Taeniopygia guttata castanotis) were
reared without their father and exposed to a tape-recorded song during the
sensitive period for song learning. When, as adults, they were reexposed to the
tutor song, the males showed increased expression of the protein products of the
immediate early genes egr-1 (ZENK) and c-fos in the NCM and caudal hyperstriatum
ventrale, but not in the conventional "song-control nuclei." The strength of the
immediate early gene response (which is a reflection of neuronal activation) in
the NCM correlated significantly and positively with the number of song elements
that the birds had copied from the tutor song. These results show localized
neural activation in response to tutor song exposure that correlates with the
strength of song learning.
PMID- 10681422
TI - The mouse Nkx-1.2 homeobox gene: alternative RNA splicing at canonical and
noncanonical splice sites.
AB - A mouse homeobox gene, Nkx-1.2, (previously termed Sax-1) that is closely related
to the Drosophila NK-1/S59 gene was cloned, and genomic DNA and cDNA were
sequenced. Nine Nkx-1.2 cDNA clones were found that correspond to three species
of Nkx-1.2 mRNA that are formed by alternative splicing at conventional 5' donor
and 3' acceptor splice sites; however, seven cDNA clones were found that
correspond to three species of Nkx-1.2 mRNA from testes that have novel TG/AC 5'
and 3' splice sites. The consensus splice sequences are: 5' donor, CC downward
arrowTGGAAG; 3' acceptor, ACTTAC downward arrow. Predicted amino acid sequences
suggest that some transcripts may be translated into proteins that lack part or
all of the homeodomain. At least three bands of Nkx-1.2 mRNA were found in RNA
from the testes. Nkx-1.2 mRNA was shown to be present in postmeiotic germ cells
of the testis and in mature spermatozoa. Nkx-1.2 mRNA also was found in regions
of the adult cerebral cortex, hippocampus, diencephalon, pons/medulla, and
cerebellum. Nkx-1.2 mRNA was found in embryos in highest abundance in 10-day
embryos; the mRNA levels decrease during further development. Nkx-1.2 mRNA also
was found in discrete zones of the embryonic mesencephalon and myelencephalon.
PMID- 10681423
TI - Elevated matrix metalloprotease and angiostatin levels in integrin alpha 1
knockout mice cause reduced tumor vascularization.
AB - Integrin alpha1beta1 is a collagen receptor abundantly expressed on microvascular
endothelial cells. As well as being the only collagen receptor able to activate
the Ras/Shc/mitogen-activated protein kinase pathway promoting fibroblast cell
proliferation, it also acts to inhibit collagen and metalloproteinase (MMP)
synthesis. We have observed that in integrin alpha1-null mice synthesis of MMP7
and MMP9 was markedly increased compared with that of their wild-type
counterparts. As MMP7 and MMP9 have been shown to generate angiostatin from
circulating plasminogen, and angiostatin acts as a potent inhibitor of
endothelial cell proliferation, we determined whether tumor vascularization was
altered in the alpha1-null mice. Tumors implanted into alpha1-null mice showed
markedly decreased vascularization, with a reduction in capillary number and
size, which was accompanied by an increase in plasma levels of angiostatin due to
the action of MMP7 and MMP9 on circulating plasminogen. In vitro analysis of
alpha1-null endothelial cells revealed a marked reduction of their proliferation
on both integrin alpha1-dependent (collagenous) and independent (noncollagenous)
substrata. This reduction was prevented by culturing alpha1-null cells with
plasma derived from plasminogen-null animals, thus omitting the source from which
to generate angiostatin. Plasma from tumor-bearing alpha1-null animals uniquely
inhibited endothelial cell growth, and this inhibition was relieved by the
coaddition of either MMP inhibitors, or antibody to angiostatin. Integrin alpha1
deficient mice thus provide a genetically characterized model for enhanced
angiostatin production and serve to reveal an unwanted potential side effect of
MMP inhibition, increased tumor angiogenesis.
PMID- 10681424
TI - Pw1/Peg3 is a potential cell death mediator and cooperates with Siah1a in p53
mediated apoptosis.
AB - Induction of wild-type p53 in mouse fibroblasts causes cell cycle arrest at the
G(1) phase, whereas coexpression of p53 and the protooncogene c-myc induces
apoptosis. Although p53 transcriptional activity generally is required for both
pathways, the molecular components mediating p53-dependent apoptosis are not well
understood. To identify factors that could mediate p53-induced cell death, we
used a comparative RNA differential display procedure. We have identified
Pw1/Peg3 as a gene product induced during p53/c-myc-mediated apoptosis. Pw1/Peg3
is not induced during p53-mediated G(1) growth arrest nor by c-myc alone.
Although it is not clear whether the induction of Pw1/Peg3 depends on p53
activity, we show that Pw1/Peg3 interacts with a p53-inducible gene product
Siah1a. We demonstrate that coexpression of Pw1/Peg3 with Siah1a induces
apoptosis independently of p53 whereas expression of Pw1/Peg3 or Siah1a
separately has no effect on cell death. These data suggest that Siah1a and
Pw1/Peg3 cooperate in the p53-mediated cell death pathway. Furthermore, we show
that inhibiting Pw1/Peg3 activity blocks p53-induced apoptosis. The observation
that Pw1/Peg3 is necessary for the p53 apoptotic response suggests a pivotal role
for this gene in determining cell death versus survival.
PMID- 10681425
TI - Induced defenses in response to an invading crab predator: an explanation of
historical and geographic phenotypic change.
AB - The expression of defensive morphologies in prey often is correlated with
predator abundance or diversity over a range of temporal and spatial scales.
These patterns are assumed to reflect natural selection via differential
predation on genetically determined, fixed phenotypes. Phenotypic variation,
however, also can reflect within-generation developmental responses to
environmental cues (phenotypic plasticity). For example, water-borne effluents
from predators can induce the production of defensive morphologies in many prey
taxa. This phenomenon, however, has been examined only on narrow scales. Here, we
demonstrate adaptive phenotypic plasticity in prey from geographically separated
populations that were reared in the presence of an introduced predator. Marine
snails exposed to predatory crab effluent in the field increased shell thickness
rapidly compared with controls. Induced changes were comparable to (i) historical
transitions in thickness previously attributed to selection by the invading
predator and (ii) present-day clinal variation predicted from water temperature
differences. Thus, predator-induced phenotypic plasticity may explain broad-scale
geographic and temporal phenotypic variation. If inducible defenses are
heritable, then selection on the reaction norm may influence coevolution between
predator and prey. Trade-offs may explain why inducible rather than constitutive
defenses have evolved in several gastropod species.
PMID- 10681426
TI - The role of cavities in protein dynamics: crystal structure of a photolytic
intermediate of a mutant myoglobin.
AB - We determined the structure of the photolytic intermediate of a sperm whale
myoglobin (Mb) mutant called Mb-YQR [Leu-(B10)-->Tyr; His(E7)-->Gln; Thr(E10)-
>Arg] to 1.4-A resolution by ultra-low temperature (20 K) x-ray diffraction.
Starting with the CO complex, illumination leads to photolysis of the Fe-CO bond,
and migration of the photolyzed carbon monoxide (CO*) to a niche in the protein
8.1 A from the heme iron; this cavity corresponds to that hosting an atom of Xe
when the crystal is equilibrated with xenon gas at 7 atmospheres [Tilton, R. F.,
Jr., Kuntz, I. D. & Petsko, G. A. (1984) Biochemistry 23, 2849-2857]. The site
occupied by CO* corresponds to that predicted by molecular dynamics simulations
previously carried out to account for the NO geminate rebinding of Mb-YQR
observed in laser photolysis experiments at room temperature. This secondary
docking site differs from the primary docking site identified by previous
crystallographic studies on the photolyzed intermediate of wild-type sperm whale
Mb performed at cryogenic temperatures [Teng et al. (1994) Nat. Struct. Biol. 1,
701-705] and room temperature [Srajer et al. (1996) Science 274, 1726-1729]. Our
experiment shows that the pathway of a small molecule in its trajectory through a
protein may be modified by site-directed mutagenesis, and that migration within
the protein matrix to the active site involves a limited number of pre-existing
cavities identified in the interior space of the protein.
PMID- 10681427
TI - The bst locus on mouse chromosome 16 is associated with age-related subretinal
neovascularization.
AB - Ocular neovascularization is the leading cause of blindness in developed
countries and often causes rapid loss of vision in age-related macular
degeneration. Acute visual loss is most often due to hemorrhage from new vessels
that have extended from the choroid into the subretinal space. Growth of abnormal
vessels beneath the retina in this condition is known as subretinal
neovascularization (SRN). Age-related animal models of macular degeneration and
SRN have not been described. Current animal models of SRN depend on chemical or
physical stimuli to initiate growth of subretinal vessels. The genes responsible
for age-related human macular degeneration with SRN have not been firmly
identified. We report an angiogenic phenotype in Bst/+ mice that is age-related,
clinically evident, and resembles human SRN. This represents a spontaneous,
genetically determined model of SRN. Bst/+ mice offer the possibility of
exploring the molecular mechanisms of SRN without the need for exogenous agents.
PMID- 10681428
TI - TOGA: an automated parsing technology for analyzing expression of nearly all
genes.
AB - We have developed an automated, high-throughput, systematic cDNA display method
called TOGA, an acronym for total gene expression analysis. TOGA utilizes 8-nt
sequences, comprised of a 4-nt restriction endonuclease cleavage site and
adjacent 4-nt parsing sequences, and their distances from the 3' ends of mRNA
molecules to give each mRNA species in an organism a single identity. The parsing
sequences are used as parts of primer-binding sites in 256 PCR-based assays
performed robotically on tissue extracts to determine simultaneously the presence
and relative concentration of nearly every mRNA in the extracts, regardless of
whether the mRNA has been discovered previously. Visualization of the
electrophoretically separated fluorescent assay products from different extracts
displayed via a Netscape browser-based graphical user interface allows the status
of each mRNA to be compared among samples and its identity to be matched with
sequences of known mRNAs compiled in databases.
PMID- 10681429
TI - Crystal structure of the zymogen form of the group A Streptococcus virulence
factor SpeB: an integrin-binding cysteine protease.
AB - Pathogenic bacteria secrete protein toxins that weaken or disable their host, and
thereby act as virulence factors. We have determined the crystal structure of
streptococcal pyrogenic exotoxin B (SpeB), a cysteine protease that is a major
virulence factor of the human pathogen Streptococcus pyogenes and participates in
invasive disease episodes, including necrotizing fasciitis. The structure,
determined for the 40-kDa precursor form of SpeB at 1.6-A resolution, reveals
that the protein is a distant homologue of the papain superfamily that includes
the mammalian cathepsins B, K, L, and S. Despite negligible sequence identity,
the protease portion has the canonical papain fold, albeit with major loop
insertions and deletions. The catalytic site differs from most other cysteine
proteases in that it lacks the Asn residue of the Cys-His-Asn triad. The
prosegment has a unique fold and inactivation mechanism that involves
displacement of the catalytically essential His residue by a loop inserted into
the active site. The structure also reveals the surface location of an integrin
binding Arg-Gly-Asp (RGD) motif that is a feature unique to SpeB among cysteine
proteases and is linked to the pathogenesis of the most invasive strains of S.
pyogenes.
PMID- 10681430
TI - Notch signaling and the determination of appendage identity.
AB - The Notch signaling pathway defines an evolutionarily conserved cell-cell
interaction mechanism that throughout development controls the ability of
precursor cells to respond to developmental signals. Here we show that Notch
signaling regulates the expression of the master control genes eyeless,
vestigial, and Distal-less, which in combination with homeotic genes induce the
formation of eyes, wings, antennae, and legs. Therefore, Notch is involved in a
common regulatory pathway for the determination of the various Drosophila
appendages.
PMID- 10681431
TI - The xeroderma pigmentosum group C gene leads to selective repair of cyclobutane
pyrimidine dimers rather than 6-4 photoproducts.
AB - We investigated the contribution of the xeroderma pigmentosum group C (XPC) gene
to DNA repair. We stably transfected XPC cells (XP4PA-SV-EB) with XPC cDNA and
selected a partially corrected (XP4PA-SE1) and a fully corrected (XP4PA-SE2)
clone. Cell survival after UVC (254 nm) exposure was low for XP4PA-SV-EB,
intermediate for XP4PA-SE1, and normal for XP4PA-SE2 cells. XP4PA-SV-EB cells had
undetectable XPC mRNA and protein levels. XP4PA-SE1 cells had 130% of normal mRNA
but 25% of normal protein levels, whereas XP4PA-SE2 cells had an 18-fold mRNA
overexpression and normal XPC protein levels compared with normal cells. We
measured cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts (6-4PP) by
using specific mAbs and the ELISA technique. XP4PA-SV-EB cells had no detectable
removal of CPD or 6-4PP from their global genome by 24 h after 30 J/m(2) UVC
exposure. The partially corrected XP4PA-SE1 cells had normal repair of CPD but
minimal repair of 6-4PP by 24 h, whereas the fully corrected XP4PA-SE2 cells
regained normal CPD and 6-4PP repair capacities. We also exposed pRSVcat plasmid
to UVC (to induce CPD and 6-4PP), to UVC + photolyase (to leave only 6-4PP on the
plasmid), or to UVB + acetophenone (to induce only CPD). Host cell reactivation
of UVB + acetophenone-, but not of UVC + photolyase-treated plasmids was normal
in XP4PA-SE1 cells. Thus, increasing XPC gene expression leads to selective
repair of CPD in the global genome. Undetectable XPC protein is associated with
no repair of CPD or 6-4PP, detectable but subnormal XPC protein levels
reconstitute CPD but not 6-4PP repair, and normal XPC protein levels fully
reconstitute both CPD and 6-4PP repair.
PMID- 10681432
TI - Leptin-deficient (ob/ob) mice are protected from T cell-mediated hepatotoxicity:
role of tumor necrosis factor alpha and IL-18.
AB - The role of leptin was investigated in two models of T cell-mediated hepatitis:
the administration of Con A or of Pseudomonas aeruginosa exotoxin A (PEA). In
both models, leptin-deficient (ob/ob) mice were protected from liver damage and
showed lower induction of tumor necrosis factor (TNF) alpha and IL-18 compared
with their lean littermates. Neutralization of TNF-alpha reduced induction of IL
18 by either Con A (70% reduction) or PEA (40% reduction). Pretreatment of lean
mice with either soluble TNF receptors or with an anti-IL-18 antiserum
significantly reduced Con A- and PEA-induced liver damage. The simultaneous
neutralization of TNF-alpha and IL-18 fully protected the mice against liver
toxicity. However, neutralization of either IL-18 or TNF-alpha did not inhibit
Con A-induced production of IFN-gamma. Thymus atrophy and alterations in the
number of circulating lymphocytes and monocytes were observed in ob/ob mice.
Exogenous leptin replacement restored the responsiveness of ob/ob mice to Con A
and normalized their lymphocyte and monocyte populations. These results
demonstrate that leptin deficiency leads to reduced production of TNF-alpha and
IL-18 associated with reduced T cell-mediated hepatotoxicity. In addition, both
TNF-alpha and IL-18 appear to be essential mediators of T cell-mediated liver
injury.
PMID- 10681433
TI - Genetic control of development of the mushroom bodies, the associative learning
centers in the Drosophila brain, by the eyeless, twin of eyeless, and Dachshund
genes.
AB - Mushroom bodies (MBs) are the centers for olfactory associative learning and
elementary cognitive functions in the Drosophila brain. By high-resolution
neuroanatomy, we show that eyeless (ey), twin of eyeless, and dachshund (dac),
which are implicated in eye development, also are expressed in the developing
MBs. Mutations of ey completely disrupted the MB neuropils, and a null mutation
of dac resulted in marked disruption and aberrant axonal projections. Genetic
analyses demonstrated that, whereas ey and dac synergistically control the
structural development of the MBs, the two genes are regulated independently in
the course of MB development. These data argue for a distinct combinatorial code
of regulatory genes for MBs as compared with eye development and suggest
conserved roles of Pax6 homologs in the genetic programs of the olfactory
learning centers of complex brains.
PMID- 10681434
TI - APC mutations are sufficient for the growth of early colorectal adenomas.
AB - It is not clear whether APC mutations are sufficient for early colorectal
adenomas to grow or whether additional mutations at other loci are required. We
previously have screened 210 early colorectal adenomas from familial adenomatous
polyposis patients for mutations and allelic loss at APC. Here, we determined
whether allelic loss at APC had any effect on the nearby alpha-catenin gene.
However, loss on 5q in familial adenomatous polyposis adenomas rarely extended as
far as alpha-catenin, and no differences in alpha-catenin protein expression were
found in tumors that showed loss encompassing both APC and alpha-catenin. We then
screened all 210 tumors for mutations at candidate loci other than APC (K-ras,
beta-catenin, and allelic loss at 1p33-p35 and 1p36) and for microsatellite
instability (MSI). Each of these loci has been implicated previously in early
colorectal tumorigenesis. One tumor harbored a beta-catenin mutation and another
MSI, but none showed K-ras mutation or allelic loss at 1p33-p35 or 1p36. These
data support the following hypotheses derived from sporadic colorectal tumors:
beta-catenin mutations are generally an alternative to mutations at APC, MSI is
not usually an early phenomenon in colorectal tumorigenesis, and K-ras mutations
are more typical of large- and moderate-sized adenomas. Contrary to some previous
reports, chromosome 1p allelic loss is infrequent in very early adenomas. APC
mutations are generally sufficient for colorectal tumors to grow to about 1-cm
diameter, although chance mutations at other loci can provide these early
colorectal adenomas with a selective advantage, and some colorectal tumors may
develop along a pathway not involving APC.
PMID- 10681435
TI - Cortical correlates of learning in monkeys adapting to a new dynamical
environment.
AB - In this paper, we describe the neural changes observed in the primary motor
cortex of two monkeys while they learned a new motor skill. The monkeys had to
adapt their reaching movements to external forces that interfered with the
execution of their arm movements. We found a sizable population of cells that
changed their tuning properties during exposure to the force field. These cells
took on the properties of neurons that are involved in the control of movement.
Furthermore, the cells maintained the acquired activity as the monkey readapted
to the no-force condition. Recent imaging studies in humans have reported the
effects of motor learning in the primary motor cortex. Our results are consistent
with the findings of these studies and provide evidence for single-cell
plasticity in the primary motor cortex of primates.
PMID- 10681436
TI - Toward Anopheles transformation: Minos element activity in anopheline cells and
embryos.
AB - The ability of the Minos transposable element to function as a transformation
vector in anopheline mosquitoes was assessed. Two recently established Anopheles
gambiae cell lines were stably transformed by using marked Minos transposons in
the presence of a helper plasmid expressing transposase. The markers were either
the green fluorescent protein or the hygromycin B phosphotransferase gene driven
by the Drosophila Hsp70 promoter. Cloning and sequencing of the integration sites
demonstrated that insertions in the cell genome occurred through the action of
Minos transposase. Furthermore, an interplasmid transposition assay established
that Minos transposase is active in the cytoplasmic environment of Anopheles
stephensi embryos: interplasmid transposition events isolated from injected
preblastoderm embryos were identified as Minos transposase-mediated integrations,
and no events were recorded in the absence of an active transposase. These
results demonstrate that Minos vectors are suitable candidates for germ-line
transformation of anopheline mosquitoes.
PMID- 10681437
TI - Identification of a gene at 11q23 encoding a guanine nucleotide exchange factor:
evidence for its fusion with MLL in acute myeloid leukemia.
AB - We have identified a gene at 11q23, telomeric to MLL, that encodes a guanine
nucleotide exchange factor (GEF). This gene is transcribed into a 9.5-kb mRNA
containing a 4.6-kb ORF. By Northern analysis, it was found to be expressed in
all human tissues examined including peripheral blood leukocytes, spleen,
prostate, testis, ovary, small intestine, colon, and minimally in thymus.
Analysis of the predicted protein sequence indicates that it has strong homology
to several members of the family of Rho GEFs that includes such oncogenes as Dbl,
Vav, Tiam, and Bcr. A patient with primary acute myeloid leukemia (AML) and a
karyotype of 51,XY,+8,+19,+3mar was found to have the 5' end of MLL at exon 6
fused in-frame with the 3' end of almost the entire ORF of this gene, which we
named LARG for leukemia-associated Rho GEF. Transcriptional orientation of both
genes at 11q23 is from centromere to telomere, consistent with other data that
suggest the MLL-LARG fusion resulted from an interstitial deletion rather than a
balanced translocation. LARG does not appear to have any homology with other MLL
partner genes reported thus far. Thus, LARG represents an additional member of
the GEF family and a novel MLL fusion partner in acute myeloid leukemia.
PMID- 10681438
TI - An artificial transcriptional activating region with unusual properties.
AB - We describe a series of transcriptional activators generated by adding amino
acids (eight in one case, six in another) to fragments of the yeast Saccharomyces
cerevisiae activator Gal4 that dimerize and bind DNA. One of the novel activating
regions identified by this procedure is unusual, compared with previously
characterized yeast activating regions, in the following ways: it works more
strongly than does Gal4's natural activating region as assayed in yeast; it is
devoid of acidic residues; and several lines of evidence suggest that it sees
targets in the yeast transcriptional machinery at least partially distinct from
those seen by Gal4's activating region.
PMID- 10681439
TI - IL-18 binding protein increases spontaneous and IL-1-induced prostaglandin
production via inhibition of IFN-gamma.
AB - IL-18 shares with IL-1 the same family of receptors and several identical signal
transduction pathways. Because of these similarities, IL-18 was investigated for
its ability to induce prostaglandin E(2) (PGE(2)) synthesis in human peripheral
blood mononuclear cells (PBMC), a prominent, proinflammatory property of IL-1. IL
18 was highly active in PBMC by inducing the synthesis of the chemokine IL-8;
however, no induction of PGE(2) synthesis nor cyclooxygenase type-2 gene
expression was observed in PBMC stimulated with IL-18. In the same cultures, IL
1beta induced a 12-fold increase in PGE(2). Although IL-1beta-induced IL-8
synthesis was augmented 3-fold by IL-18, IL-18 suppressed IL-1beta-induced PGE(2)
production by 40%. The suppressive effect of IL-18 on PGE(2) production was
mediated by interferon (IFN)-gamma because anti-human IFN-gamma-antibody
prevented IL-18-induced reduction in PGE(2). Consistent with these observations,
IL-12, a known inducer of IFN-gamma, augmented IL-1beta-induced IFN-gamma but
suppressed IL-1beta-induced PGE(2) by 75%. IL-18 binding protein (IL-18BP) is a
naturally occurring and specific inhibitor of IL-18. When recombinant IL-18BP was
added to PBMC cultures, unexpectedly, spontaneous PGE(2) production increased.
PGE(2) production was also increased by the addition of IL-18BP to PBMC
stimulated with either IL-1beta or IL-12 and also in whole blood cultures
stimulated with Staphylococcus epidermidis. These studies demonstrate that IL
18BP decreases endogenous IL-18 activity by reducing IFN-gamma-mediated
responses.
PMID- 10681440
TI - Low dielectric response in enzyme active site.
AB - The kinetics of charge transfer depend crucially on the dielectric reorganization
of the medium. In enzymatic reactions that involve charge transfer, atomic
dielectric response of the active site and of its surroundings determines the
efficiency of the protein as a catalyst. We report direct spectroscopic
measurements of the reorganization energy associated with the dielectric response
in the active site of alpha-chymotrypsin. A chromophoric inhibitor of the enzyme
is used as a spectroscopic probe. We find that water strongly affects the
dielectric reorganization in the active site of the enzyme in solution. The
reorganization energy of the protein matrix in the vicinity of the active site is
similar to that of low-polarity solvents. Surprisingly, water exhibits an
anomalously high dielectric response that cannot be described in terms of the
dielectric continuum theory. As a result, sequestering the active site from the
aqueous environment inside low-dielectric enzyme body dramatically reduces the
dielectric reorganization. This reduction is particularly important for
controlling the rate of enzymatic reactions.
PMID- 10681441
TI - Electrostatic stress in catalysis: structure and mechanism of the enzyme
orotidine monophosphate decarboxylase.
AB - Orotidine 5'-monophosphate decarboxylase catalyzes the conversion of orotidine 5'
monophosphate to uridine 5'-monophosphate, the last step in biosynthesis of
pyrimidine nucleotides. As part of a Structural Genomics Initiative, the crystal
structures of the ligand-free and the6-azauridine 5'-monophosphate-complexed
forms have been determined at 1.8 and 1.5 A, respectively. The protein assumes a
TIM-barrel fold with one side of the barrel closed off and the other side binding
the inhibitor. A unique array of alternating charges (Lys-Asp-Lys-Asp) in the
active site prompted us to apply quantum mechanical and molecular dynamics
calculations to analyze the relative contributions of ground state
destabilization and transition state stabilization to catalysis. The remarkable
catalytic power of orotidine 5'-monophosphate decarboxylase is almost exclusively
achieved via destabilization of the reactive part of the substrate, which is
compensated for by strong binding of the phosphate and ribose groups. The
computational results are consistent with a catalytic mechanism that is
characterized by Jencks's Circe effect.
PMID- 10681442
TI - The crystal structure and mechanism of orotidine 5'-monophosphate decarboxylase.
AB - The crystal structure of Bacillus subtilis orotidine 5'-monophosphate (OMP)
decarboxylase with bound uridine 5'-monophosphate has been determined by multiple
wavelength anomalous diffraction phasing techniques and refined to an R-factor of
19.3% at 2.4 A resolution. OMP decarboxylase is a dimer of two identical
subunits. Each monomer consists of a triosephosphate isomerase barrel and
contains an active site that is located across one end of the barrel and near the
dimer interface. For each active site, most of the residues are contributed by
one monomer with a few residues contributed from the adjacent monomer. The most
highly conserved residues are located in the active site and suggest a novel
catalytic mechanism for decarboxylation that is different from any previously
proposed OMP decarboxylase mechanism. The uridine 5'-monophosphate molecule is
bound to the active site such that the phosphate group is most exposed and the C5
C6 edge of the pyrimidine base is most buried. In the proposed catalytic
mechanism, the ground state of the substrate is destabilized by electrostatic
repulsion between the carboxylate of the substrate and the carboxylate of Asp60.
This repulsion is reduced in the transition state by shifting negative charge
from the carboxylate to C6 of the pyrimidine, which is close to the protonated
amine of Lys62. We propose that the decarboxylation of OMP proceeds by an
electrophilic substitution mechanism in which decarboxylation and carbon-carbon
bond protonation by Lys62 occur in a concerted reaction.
PMID- 10681443
TI - Transgenic mice neuronally expressing baculoviral p35 are resistant to diverse
types of induced apoptosis, including seizure-associated neurodegeneration.
AB - Apoptosis is a cell-suicide process that appears to play a central role not only
during normal neuronal development but also in several neuropathological disease
states. An important component of this process is a proteolytic cascade involving
a family of cysteine proteases called caspases. Caspase inhibitors have been
demonstrated to be effective in inhibiting neuronal cell death in various
apoptotic paradigms. We have created transgenic mice that neuronally express the
baculoviral caspase inhibitor p35. Neuronal expression of the p35 protein was
found to confer functional caspase inhibitory activity and prevent apoptosis in
isolated cerebellar granular cultures induced to undergo apoptosis either via
staurosporine treatment or through withdrawal of extracellular potassium.
Neuronal expression of p35 was also found to attenuate neurodegeneration
associated with the excitotoxic glutamate analogue kainic acid (KA) in vitro and
in vivo. Organotypic hippocampal cultures isolated from p35 transgenics
demonstrated lowered caspase activity and decreased apoptosis compared with wild
type when exposed to KA. In vivo injection of KA also produced decreased caspase
activity and cell death in p35 transgenics vs. wild type. These results suggest
that the presence of p35 in neurons in vivo is protective against various types
of apoptosis, including seizure-related neurodegeneration, and that caspases may
be attractive potential targets for preventing neuronal injury associated with
diseases such as epilepsy. These mice also provide a valuable tool for exploring
the role of caspases in other neuropathological conditions in which apoptosis has
been implicated.
PMID- 10681444
TI - A critical residue for isoform difference in tetrodotoxin affinity is a molecular
determinant of the external access path for local anesthetics in the cardiac
sodium channel.
AB - Membrane-impermeant quaternary derivatives of lidocaine (QX222 and QX314) block
cardiac Na(+) channels when applied from either side of the membrane, but they
block neuronal and skeletal muscle channels poorly from the outside. To find the
molecular determinants of the cardiac external QX access path, mutations of adult
rat skeletal muscle (micro1) and rat heart (rH1) Na(+) channels were studied by
two-electrode voltage clamp in Xenopus oocytes. Mutating the micro1 domain I P
loop Y401, which is the critical residue for isoform differences in tetrodotoxin
block, to the heart sequence (Y401C) allowed outside QX222 block, but its
mutation to brain type (Y401F) showed little block. mu1-Y401C accelerated
recovery from block by internal QX222. Block by external QX222 in mu1-Y401C was
diminished by chemical modification with methanethiosulfonate ethylammonium
(MTSEA) to the outer vestibule or by a double mutant (mu1-Y401C/F1579A), which
altered the putative local anesthetic binding site. The reverse mutation in heart
rH1-C374Y reduced outside QX314 block and slowed dissociation of internal QX222.
Mutation of mu1-C1572 in IVS6 to Thr, the cardiac isoform residue (C1572T),
allowed external QX222 block, and accelerated recovery from internal QX222 block,
as reported. Blocking efficacy of outside QX222 in mu1-Y401C was more than that
in mu1-C1572T, and the double mutant (mu1-Y401C/C1572T) accelerated internal QX
recovery more than mu1-Y401C or mu1-C1572T alone. We conclude that the isoform
specific residue (Tyr/Phe/Cys) in the P-loop of domain I plays an important role
in drug access as well as in tetrodotoxin binding. Isoform-specific residues in
the IP-loop and IVS6 determine outside drug access to an internal binding site.
PMID- 10681445
TI - Compartmentation protects trypanosomes from the dangerous design of glycolysis.
AB - Unlike in other organisms, in trypanosomes and other Kinetoplastida the larger
part of glycolysis takes place in a specialized organelle, called the glycosome.
At present it is impossible to remove the glycosome without changing much of the
rest of the cell. It would seem impossible, therefore, to assess the metabolic
consequences of this compartmentation. Therefore, we here develop a computer
experimentation approach, which we call computational cell biology. A validated
molecular kinetic computer replica was built of glycolysis in the parasite
Trypanosoma brucei. Removing the glycosome membrane in that replica had little
effect on the steady-state flux, which argues against the prevalent speculation
that glycosomes serve to increase flux by concentrating the enzymes. Removal of
the membrane did cause (i) the sugar phosphates to rise to unphysiologically high
levels, which must have pathological effects, and (ii) a failure to recover from
glucose deprivation. We explain these effects on the basis of the biochemical
organization of the glycosome. We conclude (i) that the glycosome protects
trypanosomes from the negative side effects of the "turbo" structure of
glycolysis and (ii) that computer experimentation based on solid molecular data
is a powerful tool to address questions that are not, or not yet, accessible to
experimentation.
PMID- 10681446
TI - A spectroscopic method for observing the domain movement of the Rieske iron
sulfur protein.
AB - The g-tensor orientation of the chemically reduced Rieske cluster in cytochrome
bc(1) complex from Rhodovulum sulfidophilum with respect to the membrane was
determined in the presence and absence of inhibitors and in the presence of
oxidized and reduced quinone in the quinol-oxidizing-site (Q(o)-site) by EPR on
two-dimensionally ordered samples. Almost identical orientations were observed
when oxidized or reduced quinone, stigmatellin, or 5-(n-undecyl)-6-hydroxy-4,7
dioxobenzothiazole was present. Occupancy of the Q(o)-site by myxothiazole
induced appearance of a minority population with a substantially differing
conformation and presence of E-beta-methoxyacrylate-stilbene significantly
reduced the contribution of the major conformation observed in the other cases.
Furthermore, when the oxidized iron-sulfur cluster was reduced at cryogenic
temperatures by the products of radiolysis, the orientation of its magnetic axes
was found to differ significantly from that of the chemically reduced center. The
"irradiation-induced" conformation converts to that of the chemically reduced
center after thawing of the sample. These results confirm the effects of Q(o)
site inhibitors on the equilibrium conformation of the Rieske iron-sulfur protein
and provide evidence for a reversible redox-influenced interconversion between
conformational states. Moreover, the data obtained with the iron-sulfur protein
demonstrate that the conformation of "EPR-inaccessible" reduction states of redox
centers can be studied by inducing changes of redox state at cryogenic
temperatures. This technique appears applicable to a wide range of comparable
electron transfer systems performing redox-induced conformational changes.
PMID- 10681447
TI - The accuracy of codon recognition by polypeptide release factors.
AB - The precision with which individual termination codons in mRNA are recognized by
protein release factors (RFs) has been measured and compared with the decoding of
sense codons by tRNA. An Escherichia coli system for protein synthesis in vitro
with purified components was used to study the accuracy of termination by RF1 and
RF2 in the presence or absence of RF3. The efficiency of factor-dependent
termination at all sense codons differing from any of the three stop codons by a
single mutation was measured and compared with the efficiency of termination at
the three stop codons. RF1 and RF2 discriminate against sense codons related to
stop codons by between 3 and more than 6 orders of magnitude. This high level of
accuracy is obtained without energy-driven error correction (proofreading), in
contrast to codon-dependent aminoacyl-tRNA recognition by ribosomes. Two codons,
UAU and UGG, stand out as hotspots for RF-dependent premature termination.
PMID- 10681448
TI - Association of SWAP-70 with the B cell antigen receptor complex.
AB - SWAP-70 is a component of an enzyme complex that recombines Ig switch regions in
vitro. We report here the cloning of the human cDNA and its B lymphocyte-specific
expression. Although its sequence contains three nuclear localization signals, in
small resting B cells, SWAP-70 is mainly found in the cytoplasm. On stimulation,
SWAP-70 translocates to the nucleus. In activated, class-switching B cell
cultures, it is associated with membrane IgG, but not IgM. The membrane Ig
association requires a functional pleckstrin homology domain and is controlled by
the C terminus. We suggest that SWAP-70 is involved not only in nuclear events
but also in signaling in B cell activation.
PMID- 10681449
TI - Noise-based switches and amplifiers for gene expression.
AB - The regulation of cellular function is often controlled at the level of gene
transcription. Such genetic regulation usually consists of interacting networks,
whereby gene products from a single network can act to control their own
expression or the production of protein in another network. Engineered control of
cellular function through the design and manipulation of such networks lies
within the constraints of current technology. Here we develop a model describing
the regulation of gene expression and elucidate the effects of noise on the
formulation. We consider a single network derived from bacteriophage lambda and
construct a two-parameter deterministic model describing the temporal evolution
of the concentration of lambda repressor protein. Bistability in the steady-state
protein concentration arises naturally, and we show how the bistable regime is
enhanced with the addition of the first operator site in the promotor region. We
then show how additive and multiplicative external noise can be used to regulate
expression. In the additive case, we demonstrate the utility of such control
through the construction of a protein switch, whereby protein production is
turned "on" and "off" by using short noise pulses. In the multiplicative case, we
show that small deviations in the transcription rate can lead to large
fluctuations in the production of protein, and we describe how these fluctuations
can be used to amplify protein production significantly. These results suggest
that an external noise source could be used as a switch and/or amplifier for gene
expression. Such a development could have important implications for gene
therapy.
PMID- 10681450
TI - Vitamin E reduces chromosomal damage and inhibits hepatic tumor formation in a
transgenic mouse model.
AB - We have previously shown that chronic activation of mitogenic signaling induced
by over-expression of c-myc and transforming growth factor-alpha (TGFalpha)
transgenes in mouse liver induces a state of oxidative stress. We therefore
proposed that increased reactive oxygen species (ROS) generation might be
responsible for the extensive chromosomal damage and acceleration of
hepatocarcinogenesis characteristic for TGFalpha/c-myc mice. In this study, we
show that vitamin E (VE), a potent free radical scavenging antioxidant, is able
to protect liver tissue against oxidative stress and suppress tumorigenic
potential of c-myc oncogene. Dietary supplementation with VE, starting from
weaning, decreased ROS generation coincident with a marked inhibition of
hepatocyte proliferation while increasing the chromosomal as well as mtDNA
stability in the liver. Similarly, dietary VE reduced liver dysplasia and
increased viability of hepatocytes. At 6 mo of age, VE treatment decreased the
incidence of adenomas by 65% and prevented malignant conversion. These results
indicate that ROS generated by over-expression of c-myc and TGFalpha in the liver
are the primary carcinogenic agents in this animal model. Furthermore, the data
demonstrate that dietary supplementation of VE can effectively inhibit liver
cancer development.
PMID- 10681451
TI - Meiotic instability of CAG repeat tracts occurs by double-strand break repair in
yeast.
AB - Expansion of trinucleotide repeats is associated with a growing number of human
diseases. The mechanism and timing of expansion of the repeat tract are poorly
understood. In humans, trinucleotide repeats show extreme meiotic instability,
and expansion of the repeat tract has been suggested to occur in the germ-line
mitotic divisions or postmeiotically during early divisions of the embryo.
Studies in model organisms have indicated that polymerase slippage plays a major
role in the repeat tract instability and meiotic instability is severalfold
higher than the mitotic instability. We show here that meiotic instability of the
CAG/CTG repeat tract in yeast is associated with double-strand break (DSB)
formation within the repeated sequences, and that the DSB formation is dependent
on the meiotic recombination machinery. The DSB repair results in both expansions
and contractions of the CAG repeat tract.
PMID- 10681452
TI - The hippocampal neurons of neuronal apoptosis inhibitory protein 1 (NAIP1)
deleted mice display increased vulnerability to kainic acid-induced injury.
AB - The neuronal apoptosis inhibitory protein (NAIP) is a member of a novel family of
inhibitor of apoptosis (IAP) proteins. The IAP genes are highly conserved from
baculovirus to metazoans and suppress apoptosis induced by a variety of triggers
both in vitro and in vivo. Here we describe the generation and characterization
of mice with the targeted deletion of NAIP1. We demonstrate that the NAIP1
deleted mice develop normally. However, the survival of pyramidal neurons in the
hippocampus after kainic acid-induced limbic seizures is greatly reduced in the
NAIP1 knock-out animals. Thus, although NAIP1 is not necessary for normal
development of murine central nervous system, the endogenous NAIP1 is required
for neuronal survival in pathological conditions.
PMID- 10681453
TI - Dendritic cells acquire the MAGE-3 human tumor antigen from apoptotic cells and
induce a class I-restricted T cell response.
AB - In an attempt to transduce monocyte-derived dendritic cells (DCs) with a
retroviral vector coding for an intracytoplasmic tumor antigen (TAA), we were
confronted by the evident dissociation between the ability of the treated DCs to
induce a TAA-specific response, and the presence of integrated vector proviral
DNA. The TAA, i.e., MAGE-3, was acquired by DCs and presented to immune
effectors, thanks to the property of DCs to uptake the apoptotic bodies released
by the irradiated vector-producing cells. Indeed, we observed that upon
irradiation vector-producing cells underwent apoptotic cell death, monitored by
annexin V and propidium iodide staining, and were phagocytosed by DCs.
Lymphocytes obtained from a patient affected by a MAGE-3(+) melanoma, were
stimulated in vitro with autologous DCs previously exposed to irradiated MAGE-3
expressing cells. This procedure led to the induction of MAGE-3-specific
cytotoxic effectors, directed against a yet unknown MAGE-3 epitope presented by
HLA-A*B5201 molecules. These data demonstrate that DCs can present engulfed human
TAAs, thus providing strategies for cancer vaccination.
PMID- 10681454
TI - Transferrin receptor 2: continued expression in mouse liver in the face of iron
overload and in hereditary hemochromatosis.
AB - Hereditary hemochromatosis (HH) is a common autosomal recessive disorder
characterized by excess absorption of dietary iron and progressive iron
deposition in several tissues, particularly liver. Liver disease resulting from
iron toxicity is the major cause of death in HH. Hepatic iron loading in HH is
progressive despite down-regulation of the classical transferrin receptor (TfR).
Recently a human cDNA highly homologous to TfR was identified and reported to
encode a protein (TfR2) that binds holotransferrin and mediates uptake of
transferrin-bound iron. We independently identified a full-length murine EST
encoding the mouse orthologue of the human TfR2. Although homologous to murine
TfR in the coding region, the TfR2 transcript does not contain the iron
responsive elements found in the 3' untranslated sequence of TfR mRNA. To
determine the potential role for TfR2 in iron uptake by liver, we investigated
TfR and TfR2 expression in normal mice and murine models of dietary iron overload
(2% carbonyl iron), dietary iron deficiency (gastric parietal cell ablation), and
HH (HFE -/-). Northern blot analyses demonstrated distinct tissue-specific
patterns of expression for TfR and TfR2, with TfR2 expressed highly only in liver
where TfR expression is low. In situ hybridization demonstrated abundant TfR2
expression in hepatocytes. In contrast to TfR, TfR2 expression in liver was not
increased in iron deficiency. Furthermore, hepatic expression of TfR2 was not
down-regulated with dietary iron loading or in the HFE -/- model of HH. From
these observations, we propose that TfR2 allows continued uptake of Tf-bound iron
by hepatocytes even after TfR has been down-regulated by iron overload, and this
uptake contributes to the susceptibility of liver to iron loading in HH.
PMID- 10681455
TI - The protease thrombin is an endogenous mediator of hippocampal neuroprotection
against ischemia at low concentrations but causes degeneration at high
concentrations.
AB - We have considered the extracellular serine protease thrombin and its receptor as
endogenous mediators of neuronal protection against brain ischemia. Exposure of
gerbils to prior mild ischemic insults, here two relatively short-lasting
occlusions (2 min) of both common carotid arteries applied at 1-day intervals 2
days before a severe occlusion (6 min), caused a robust ischemic tolerance of
hippocampal CA1 neurons. This resistance was impaired if the specific thrombin
inhibitor hirudin was injected intracerebroventricularly before each short
lasting insult. Thus, efficient native neuroprotective mechanisms exist and
endogenous thrombin seems to be involved therein. In vitro experiments using
organotypic slice cultures of rat hippocampus revealed that thrombin can have
protective but also deleterious effects on hippocampal CA1 neurons. Low
concentrations of thrombin (50 pM, 0.01 unit/ml) or of a synthetic thrombin
receptor agonist (10 microM) induced significant neuroprotection against
experimental ischemia. In contrast, 50 nM (10 units/ml) thrombin decreased
further the reduced neuronal survival that follows the deprivation of oxygen and
glucose, and 500 nM even caused neuronal cell death by itself. Degenerative
thrombin actions also might be relevant in vivo, because hirudin increased the
number of surviving neurons when applied before a 6-min occlusion. Among the
thrombin concentrations tested, 50 pM induced intracellular Ca(2+) spikes in fura
2-loaded CA1 neurons whereas higher concentrations caused a sustained Ca(2+)
elevation. Thus, distinct Ca(2+) signals may define whether or not thrombin
initiates protection. Taken together, in vivo and in vitro data suggest that
thrombin can determine neuronal cell death or survival after brain ischemia.
PMID- 10681456
TI - Representation of actions in rats: the role of cerebellum in learning spatial
performances by observation.
AB - Experimental evidence demonstrates that cerebellar networks are involved in
spatial learning, controlling the acquisition of exploration strategies without
blocking motor execution of the task. Action learning by observation has been
considered somehow related to motor physiology, because it provides a way of
learning performances that is almost as effective as the actual execution of
actions. Neuroimaging studies demonstrate that observation of movements performed
by others, imagination of actions, and actual execution of motor performances
share common neural substrates and that the cerebellum is among these shared
areas. The present paper analyzes the effects of observation in learning a
spatial task, focusing on the cerebellar role in learning a spatial ability
through observation. We allowed normal rats to observe 200 Morris water maze
trials performed by companion rats. After this observation training, "observer"
rats underwent a hemicerebellectomy and then were tested in the Morris water
maze. In spite of the cerebellar lesion, they displayed no spatial defects,
exhibiting exploration abilities comparable to controls. When the cerebellar
lesion preceded observation training, a complete lack of spatial observational
learning was observed. Thus, as demonstrated already for the acquisition of
spatial procedures through actual execution, cerebellar circuits appear to play a
key role in the acquisition of spatial procedures also through observation. In
conclusion, the present results provide strong support for a common neural basis
in the observation of actions that are to be reproduced as well as in the actual
production of the same actions.
PMID- 10681457
TI - Oral administration of a dual analog of two myasthenogenic T cell epitopes down
regulates experimental autoimmune myasthenia gravis in mice.
AB - Myasthenia gravis (MG) and experimental autoimmune MG (EAMG) are T cell
regulated, antibody-mediated autoimmune diseases. The major autoantigen in MG is
the nicotinic acetylcholine receptor (AChR). Two peptides, representing sequences
of the human AChR alpha-subunit, p195-212 and p259-271, were previously shown to
be immunodominant T cell epitopes in MG patients as well as, respectively, in SJL
and BALB/c mice. A dual analog (termed Lys-262-Ala-207) composed of the tandemly
arranged two single amino acid analogs of p195-212 and p259-271 was shown to
inhibit, in vitro and in vivo, MG-associated autoimmune responses. Furthermore,
the dual analog could down-regulate myasthenogenic manifestations in mice with
EAMG that was induced by inoculation of a pathogenic T cell line. In the present
study, the ability of the dual analog to treat EAMG induced in susceptible
C57BL/6 mice by native Torpedo AChR was evaluated. Mice that were diagnosed to
have clinical symptoms of EAMG were treated with the dual analog by oral
administration, 500 microg per mouse three times a week for 5-8 weeks. Treatment
with the dual analog down-regulated the clinical manifestations of the ongoing
disease as assessed by the clinical score, grip strength (measured by a grip
strength meter), and electromyography. The effects on the clinical EAMG
correlated with a reduced production of anti-AChR antibody as well as a decrease
in the secretion of interleukin-2 and, more dramatically, interferon-gamma, in
response to AChR triggering. Thus, the dual analog is an efficient
immunomodulator of EAMG in mice and might be of specific therapeutic potential
for MG.
PMID- 10681458
TI - Molecular mobility in the cytoplasm: an approach to describe and predict lifespan
of dry germplasm.
AB - Molecular mobility is increasingly considered a key factor influencing storage
stability of biomolecular substances, because it is thought to control the rate
of detrimental reactions responsible for reducing the shelf life of, for
instance, pharmaceuticals, food, and germplasm. We investigated the relationship
between aging rates of germplasm and the rotational motion of a polar spin probe
in the cytoplasm under different storage conditions using saturation transfer
electron paramagnetic resonance spectroscopy. Rotational motion of the spin probe
in the cytoplasm of seed and pollen of various plant species changed as a
function of moisture content and temperature in a manner similar to aging rates
or longevity. A linear relationship was established between the logarithms of
rotational motion and aging rates or longevity. This linearity suggests that
detrimental aging rates are associated with molecular mobility in the cytoplasm.
By measuring the rotational correlation times at low temperatures at which
experimental determination of longevity is practically impossible, this linearity
enabled us to predict vigor loss or longevity. At subzero temperatures, moisture
contents for maximum life span were predicted to be higher than those hitherto
used in genebanks, urging for a reexamination of seed storage protocols.
PMID- 10681459
TI - Engineered herpes simplex virus expressing IL-12 in the treatment of experimental
murine brain tumors.
AB - Genetically engineered, neuroattenuated herpes simplex viruses (HSVs) expressing
various cytokines can improve survival when used in the treatment of experimental
brain tumors. These attenuated viruses have both copies of gamma(1)34.5 deleted.
Recently, we demonstrated increased survival of C57BL/6 mice bearing syngeneic GL
261 gliomas when treated with an engineered HSV expressing IL-4, as compared with
treatment with the parent construct (gamma(1)34. 5(-)) alone or with a virus
expressing IL-10. Herein, we report construction of a conditionally replication
competent mutant expressing both subunits of mIL-12 (M002) and its evaluation in
a syngeneic neuroblastoma murine model. IL-12 induces a helper T cell subset type
1 response, which may induce more durable antitumor effects. In vitro studies
showed that, when infected with M002, both Vero cells and murine Neuro-2a
neuroblastoma cells produced physiologically relevant levels of IL-12
heterodimers, as determined by ELISA. M002 was cytotoxic for Neuro-2a cells and
human glioma cell lines U251MG and D54MG. Neurotoxicity studies, as defined by
plaque-forming units/LD(50), performed in HSV-1-sensitive A/J strain mice found
that M002 was not toxic even at high doses. When evaluated in an intracranial
syngeneic neuroblastoma murine model, median survival of M002-treated animals was
significantly longer than the median survival of animals treated with R3659, the
parent gamma(1)34.5(-) mutant lacking any cytokine gene insert.
Immunohistochemical analysis of M002-treated tumors identified a pronounced
influx of CD4(+) T cells and macrophages as well as CD8(+) cells when compared
with an analysis of R3659-treated tumors. We conclude that M002 produced a
survival benefit via oncolytic effects combined with immunologic effects
meditated by helper T cells of subset type 1.
PMID- 10681460
TI - Patterned deposition of cells and proteins onto surfaces by using three
dimensional microfluidic systems.
AB - Three-dimensional microfluidic systems were fabricated and used to pattern
proteins and mammalian cells on a planar substrate. The three-dimensional
topology of the microfluidic network in the stamp makes this technique a
versatile one with which to pattern multiple types of proteins and cells in
complex, discontinuous structures on a surface. The channel structure, formed by
the stamp when it is in contact with the surface of the substrate, limits
migration and growth of cells in the channels. With the channel structure in
contact with the surface, the cells stop dividing once they form a confluent
layer. Removal of the stamp permits the cells to spread and divide.
PMID- 10681461
TI - Loss of brain-derived neurotrophic factor-dependent neural crest-derived sensory
neurons in neurotrophin-4 mutant mice.
AB - Peripheral ganglion neurons confer sensory information including touch, pain,
temperature, and proprioception. Sensory modality is linked to specific
neurotrophin (NTF) requirements. NT-3 supports survival of neurons that
differentiate primarily into proprioceptors whereas nerve growth factor and brain
derived neurotrophic factor (BDNF) support subpopulations that transmit
nociception and mechanoreception, respectively. We examined sensory neurons of
gene-targeted mouse mutants at the NT-4, BDNF, NT-3, and TrkA loci. We show that
NT-4 functions early in gangliogenesis, upstream of BDNF. In the absence of NT-4
function, BDNF-dependent, TrkB-expressing neurons fail to appear. The results are
consistent with the model that precursor cells intended to become BDNF-dependent
mechanoreceptors instead differentiate into NT-3-dependent proprioceptive
neurons.
PMID- 10681462
TI - Physical contact between lipopolysaccharide and toll-like receptor 4 revealed by
genetic complementation.
AB - Some mammalian species show an ability to discriminate between different
lipopolysaccharide (LPS) partial structures (for example, lipid A and its
congener LA-14-PP, which lacks secondary acyl chains), whereas others do not.
Using a novel genetic complementation system involving the transduction of
immortalized macrophages from genetically unresponsive C3H/HeJ mice, we now have
shown that the species-dependent discrimination between intact LPS and tetra-acyl
LPS partial structures is fully attributable to the species origin of Toll-like
receptor 4 (Tlr4), an essential membrane-spanning component of the mammalian LPS
sensor. Because Tlr4 interprets the chemical structure of an LPS molecule, we
conclude that LPS must achieve close physical proximity with Tlr4 in the course
of signal transduction.
PMID- 10681463
TI - The cellulose synthase gene of Dictyostelium.
AB - Cellulose is a major component of the extracellular matrices formed during
development of the social amoeba, Dictyostelium discoideum. We isolated
insertional mutants that failed to accumulate cellulose and had no cellulose
synthase activity at any stage of development. Development proceeded normally in
the null mutants up to the beginning of stalk formation, at which point the
culminating structures collapsed onto themselves, then proceeded to attempt
culmination again. No spores or stalk cells were ever made in the mutants, with
all cells eventually lysing. The predicted product of the disrupted gene (dcsA)
showed significant similarity to the catalytic subunit of cellulose synthases
found in bacteria. Enzyme activity and normal development were recovered in
strains transformed with a construct expressing the intact dcsA gene. Growing
amoebae carrying the construct accumulated the protein product of dcsA, but did
not make cellulose until they had developed for at least 10 hr. These studies
show directly that the product of dcsA is necessary, but not sufficient, for
synthesis of cellulose.
PMID- 10681464
TI - Arabidopsis cytochrome P450s that catalyze the first step of tryptophan-dependent
indole-3-acetic acid biosynthesis.
AB - Plants synthesize numerous secondary metabolites that are used as developmental
signals or as defense against pathogens. Tryptophan (Trp)-derived secondary
metabolites include camalexin, indole glucosinolates, and indole-3-acetic acid
(IAA); however, the steps in their synthesis from Trp or its precursors remain
unclear. We have identified two Arabidopsis cytochrome P450s (CYP79B2 and
CYP79B3) that can convert Trp to indole-3-acetaldoxime (IAOx), a precursor to IAA
and indole glucosinolates.
PMID- 10681466
TI - Protein folding and unfolding on a complex energy landscape.
AB - Recent theories of protein folding suggest that individual proteins within a
large ensemble may follow different routes in conformation space from the
unfolded state toward the native state and vice versa. Herein, we introduce a new
type of kinetics experiment that shows how different unfolding pathways can be
selected by varying the initial reaction conditions. The relaxation kinetics of
the major cold shock protein of Escherichia coli (CspA) in response to a laser
induced temperature jump are exponential for small temperature jumps, indicative
of folding through a two-state mechanism. However, for larger jumps, the kinetics
become strongly nonexponential, implying the existence of multiple unfolding
pathways. We provide evidence that both unfolding across an energy barrier and
diffusive downhill unfolding can occur simultaneously in the same ensemble and
provide the experimental requirements for these to be observed.
PMID- 10681467
TI - Defensive use of a fecal thatch by a beetle larva (Hemisphaerota cyanea).
AB - The larva of the tortoise beetle, Hemisphaerota cyanea (Chrysomelidae,
Cassidinae), constructs a thatch from long filamentous fecal strands, beneath
which it is totally concealed. The thatch is not discarded at molting but is
enlarged by addition of strands as the larva grows. Thatch construction begins
when the larva hatches from the egg. Pupation occurs beneath the thatch. Two
predators, a coccinellid beetle larva (Cycloneda sanguinea) and a pentatomid bug
(Stiretrus anchorago), were shown to be thwarted by the thatch. However, one
predator, a carabid beetle (Calleida viridipennis), feeds on the larva by either
forcing itself beneath the thatch or chewing its way into it. The attack behavior
is stereotyped, suggesting that the beetle feeds on Hemisphaerota larvae as a
matter of routine.
PMID- 10681465
TI - The gene coding for the Hrp pilus structural protein is required for type III
secretion of Hrp and Avr proteins in Pseudomonas syringae pv. tomato.
AB - Bacterial surface appendages called pili often are associated with DNA and/or
protein transfer between cells. The exact function of pili in the transfer
process is not understood and is a matter of considerable debate. The Hrp pilus
is assembled by the Hrp type III protein secretion system of Pseudomonas syringae
pv. tomato (Pst) strain DC3000. In this study, we show that the hrpA gene, which
encodes the major subunit of the Hrp pilus, is required for secretion of putative
virulence proteins, such as HrpW and AvrPto. In addition, the hrpA gene is
required for full expression of genes that encode regulatory, secretion, and
effector proteins of the type III secretion system. hrpA-mediated gene regulation
apparently is through effect on the mRNA level of two previously characterized
regulatory genes, hrpR and hrpS. Ectopic expression of the hrpRS gene operon
restored gene expression, but not protein secretion, in the hrpA mutant. Three
single amino acid mutations at the HrpA carboxyl terminus were identified that
affect the secretion or regulatory function of the HrpA protein. These results
define an essential role of the Hrp pilus structural gene in protein secretion
and coordinate regulation of the type III secretion system in Pst DC3000.
PMID- 10681469
TI - Debeerius ellefseni (Fam. Nov., Gen. Nov., Spec. Nov.), an autodiastylic
chondrichthyan from the Mississippian bear gulch limestone of Montana (USA), the
relationships of the chondrichthyes, and comments on gnathostome evolution.
AB - Debeerius ellefseni is an autodiastylic, operculate chondrichthyan from the 320
million-year-old Bear Gulch limestone (Heath Formation, Big Snowy Group, Upper
Chesterian) of Montana, USA. Cranial and postcranial morphologies show strong
affinities to the holocephalan cochliodonts and Chimaeriformes. The heterodont
dentition is, however, selachian in plan. Debeerius ellefseni's cranial,
postcranial, and suspensorial characters identify this fish as a paraselachian,
an early chondrichthyan with a morphology intermediate to the chimaeroid and
selachian plans. They also support the division of Chondrichthyes into the
subclasses Elasmobranchii and Euchondrocephali (Paraselachii +
Holocephalimorpha). Details of the anatomy of D. ellefseni are reviewed in light
of recent advances in understanding vertebrate splanchnocranial development and,
thus, permit a discussion of historically problematic craniate features,
including labial cartilages and the nature of the mandibular arch relative to
hyoid and branchial arches. Developmental and evolutionary considerations of
these characters are consistent with an embryonic body plan shared by both
lampreys and gnathostomes. Debeerius ellefseni's suspensorium corresponds to the
plesiomorphous gnathostome condition theorized by DeBeer and Moy-Thomas in 1935.
The description of this autodiastylic condition is clarified to include
observations of the hyoid arch, which is complete with a pharyngohyal and
provides support for the primary opercular valve. The confirmation of an
autodiastylic suspensorium requires a reexamination of the commonly accepted
paradigm for jaw evolution. The selachian, chimaeroid, and actinopterygian
conditions are all derivable from this plesiomorphous state; the placoderm and
sarcopterygian conditions are related and probably similarly derived. The
comparable osteichthyan suspensorium is best represented by the suspensorial
condition of coelacanths.
PMID- 10681468
TI - A protein-based therapeutic for human cytomegalovirus infection.
AB - Current antiviral strategies target viral gene products. Although initially
successful, their severe toxicity and susceptibility to circumvention by the
generation of drug-resistant variants limit their usefulness. By contrast, the
central role of the host cell serine endoprotease furin in the proteolytic
activation of numerous pathogens points to the endoprotease as a strategic target
for therapeutics. Herein, we show that the production of infectious human
cytomegalovirus is dramatically reduced by exogenous addition of a bioengineered
serpin, alpha(1)-PDX. This protein is a potent and selective furin inhibitor
(K(i) = 0.6 nM) and is 10-fold more effective than currently used antiherpetic
agents in cell-culture models. The requirement of furin for the processing of
envelope glycoproteins from many pathogenic viruses and for the activation of
several bacterial toxins suggests that selective inhibitors of furin have
potential as broad-based anti-pathogens.
PMID- 10681470
TI - Descriptive study of the diaphragm and lungs in the short-nosed echidna,
Tachyglossus aculeatus (Mammalia: monotremata).
AB - In this descriptive study, we characterize the diaphragm and lungs of the short
nosed echidna, Tachyglossus aculeatus, using a combination of gross anatomical,
light-microscopic, electron microscopic, and morphometric techniques, including
airway casting. The diaphragm is inclined from ventro-cranial to dorso-caudal and
possesses a large central tendon (centrum tendineum). The crural and costal
muscle groups and the associated trigoni are located in the same positions as in
other mammals. The bronchial branching pattern reveals cranially broad, tapering
stem bronchi and an unusually small number of first order bronchi. The
asymmetrical primary branching pattern and possibly also the asymmetry of right
and left lungs are plesiomorphic within the Mammalia. The histology and
ultrastructure of the airways and lung parenchyma reveal no unusual features:
alveolar type 1 and type 2 cells in the parenchyma; type 2 cells, exocrine
bronchiolar cells (Clara cells), ciliated cells, and goblet cells in the terminal
airways and the latter two cell types in the bronchi. Both a double and a single
capillary net are found on the interalveolar septa. The high capillary loading of
the double net may be of selective advantage because of long apneas and low
metabolic rate in the echidna.
PMID- 10681471
TI - Glycoconjugate sugar residues in the chick embryo developing lung: a lectin
histochemical study.
AB - A lectin histochemical study was performed to investigate the distribution and
changes of the oligosaccharidic component of the glycoconjugates in the lung of
chick embryos, of 1-day-old chick, and of the adult animal. For this purpose, a
battery of seven horseradish peroxidase-conjugated lectins (PNA, SBA, DBA, WGA,
Con A, LTA, and UEA I) were employed. During the first phase of parabronchi and
atria formation, D-galactose-(beta1-->3)-N-acetyl-D-galactosamine, beta-N-acetyl
D-galactosamine, D-glucosamine, alpha-D-mannose, and sialic acid, present at the
level of the surface and of cytoplasmic granules of the lining epithelial cells,
seem to play a role in regulating morphogenetic phenomena. In the subsequent
phases, the parabronchial lumen and the atrial cavities were characterized by the
presence of lectin-reactive material rich in terminal D-galactose-(beta1-->3)-N
acetyl-D-galactosamine, beta-N-acetyl-D-galactosamine, D-glucosamine and alpha-D
mannose. From day 18 onwards and immediately after hatching, the free border of
the cells lining the air capillaries was characterized by the presence of beta-N
acetyl-D-galactosamine and alpha-D-mannose. The appearance of these sugar
residues was concomitant with the beginning of respiratory activity.
PMID- 10681472
TI - Ovarian germinal epithelium and folliculogenesis in the common snook, Centropomus
undecimalis (Teleostei: centropomidae).
AB - The ovarian germinal epithelium in the common snook, Centropomus undecimalis, is
described. It consists of epithelial and prefollicle cells that surround germ
cells, either oogonia or oocytes, respectively. The germinal epithelium borders a
body cavity, the ovarian lumen, and is supported by a basement membrane that also
separates the epithelial compartment of the ovarian lamellae from the stromal
compartment. During folliculogenesis, the epithelial cells, whose cytoplasmic
processes encompass meiotic oocytes, transform into prefollicle cells, which
become follicle cells at the completion of folliculogenesis. The follicle is a
derivative of the germinal epithelium and is composed of the oocyte and
surrounding follicle cells. It is separated from the encompassing theca by a
basement membrane. The cells that form the theca interna are derived from
prethecal cells within the extravascular space of the ovarian stroma. The theca
externa differentiates from undifferentiated cells within the stromal compartment
of the ovary, from within the extravascular space. The theca interna and the
theca externa are not considered to be part of the follicle and are derived from
a different ovarian compartment than the follicle. Meiosis commences while
oocytes are still within the germinal epithelium and proceeds as far as arrested
diplotene of the first meiotic prophase. The primary growth phase of oocyte
development also begins while oocytes are still within the germinal epithelium or
attached to it in a cell nest. The definitions used herein are consistent between
sexes and with the mammalian literature.
PMID- 10681473
TI - Renal anatomy in sparrows from different environments.
AB - The renal anatomy of three species of sparrows, two from mesic areas, the House
Sparrow (Passer domesticus) and Song Sparrow (Melospiza melodia), and one salt
marsh species, the Savannah Sparrow (Passerculus sandwichensis) was examined.
Electron microscopy was used to describe the ultrastructure of the nephron. In
addition, stereology was used to quantify the volumes of cortex, medulla, and
major vasculature of the kidneys, and the volumes and surface areas occupied by
individual nephron components. There appeared to be no differences in the
ultrastructural anatomy of the nephrons among the sparrows. Proximal tubules
contained both narrow and wide intercellular spaces filled with interdigitations
of the basolateral membrane. The thin limbs of Henle contained very wide
intercellular spaces which were absent in the thick limbs of Henle. The distal
tubule cells contained short, apical microvilli and infoldings of the basolateral
membrane. In cross section, the medullary cones of all birds display an outer
ring of thick limbs of Henle which surround an inner ring of collecting ducts,
which in turn surround a central core of thin limbs of Henle. The Savannah
Sparrow has a significantly higher volume of medulla compared to the two more
mesic species. Within the cortex, the Savannah Sparrow also has a significantly
higher volume of proximal tubules but a significantly lower volume of distal
tubules than the other species. Within the medulla, the Savannah Sparrow has a
significantly higher volume and surface area of capillaries, and a significantly
higher surface area of thick limbs of Henle and collecting ducts than the mesic
species. These data suggest that the salt marsh Savannah Sparrow has the renal
morphology necessary to produce a more highly concentrated urine than the mesic
zone species.
PMID- 10681474
TI - Location of the vector of jaw muscle force in mammals.
AB - Previous work has suggested that the third molar lies just in front of the point
where the resultant vector of jaw muscle force, estimated from dissections,
intersects the tooth row. This point meets the jaw such that the vector is 30% of
jaw length from the jaw joint. Thus, the vector divides the jaw in the ratio of
3:7 when measurements are taken perpendicular to the vector. In practice,
however, distances along mammalian jaws are typically measured on an easily
determined line such as a line from one end of the tooth row to the other. The
position of the jaw joint is then projected onto this line. As a rule, such a
line is not perpendicular to the vector and so the distance from the projection
of the joint, out to the rear of the third molar (and the vector's intersection),
is different in different mammals. Rarely is this distance 30% of total jaw
length. However, when the location of the vector's intersection is measured along
the tooth row, this position varies directly with the inclination of the vector;
a vector inclined posteriorly intersects the tooth row far from the projection of
the joint and an anterior vector's intersection is relatively close. Only a
vector perpendicular to the line from one end of the tooth row to the other
intersects at 30%. This obvious point suggests a way to test the above hypotheses
when the inclination of the vector is not known exactly. The predicted
relationship between the distance to the molar, as a percentage of the total jaw
length, and the approximate inclination of the vector derived from muscle weights
(posterior or anterior depending on whether the temporalis or the
masseter/pterygoid, respectively, is dominant) was observed in a sample of 46
different mammals.
PMID- 10681476
TI - Are allografts the 'choice' in infectious endocarditis with periannular abscess?
PMID- 10681477
TI - Functional assessment of coronary stenosis: it does make sense, but why don't I
do it more often?
PMID- 10681478
TI - Neural-natriuretic hormone interactions.
PMID- 10681479
TI - Depression: the sleeping giant.
PMID- 10681480
TI - May aspirin be replaced in the treatment of myocardial infarction?
PMID- 10681481
TI - QT dispersion in ischaemic heart disease.
PMID- 10681482
TI - Why are smoking cessation strategies not implemented more effectively in clinical
practice?
PMID- 10681483
TI - Heart rate variability: a telltale of health or disease.
PMID- 10681484
TI - Diagnosis and treatment of nicotine dependence with emphasis on nicotine
replacement therapy. A status report.
AB - Tobacco use is a global health care problem. Repetitive exposure to nicotine
produces neuroadaptation resulting in nicotine dependence. Cigarette smoking is
particularly addictive due to the repeated delivery of bolus doses of nicotine to
the bloodstream. Although compulsive tobacco use is sustained by nicotine
addiction, it is the toxic combustion products in tobacco smoke such as carbon
monoxide and oxidant gases that adversely affect the cardiovascular system.
Smoking cessation produces significant health benefits and is a very cost
effective intervention. Evidence that nicotine is the addictive component of
tobacco provides the rationale for using nicotine replacement therapy to aid
cessation. Nicotine replacement therapy doubles successful smoking cessation
rates and evidence-based guidelines for the treatment of tobacco addiction
recommend routine use of nicotine replacement therapy, particularly in heavily
dependent smokers. Success rates of up to 40% can be achieved in specialist
clinics. Despite early concerns regarding the safety of nicotine replacement
therapy in smokers with heart disease, it is now clear that the health risks of
using nicotine replacement therapy to assist such patients to stop, or
significantly reduce, smoking far outweigh any treatment-related risks.
PMID- 10681485
TI - Dispersion of ventricular repolarization is determined by the presence of
myocardial viability in patients with old myocardial infarction. A dobutamine
stress echocardiography study.
AB - AIMS: The study sought to investigate the relationship of myocardial viability
detected by dobutamine stress echocardiography to changes of QT dispersion and to
the presence of arrhythmias during dobutamine infusion in patients with old
myocardial infarction. We also examined whether patency of the infarct-related
artery is associated with the presence of myocardial viability and QT dispersion.
BACKGROUND: QT dispersion and myocardial variability have been associated with
the presence of arrhythmias during late post infarction but not during dobutamine
stress. Restoration of anterograde coronary flow has beneficial effects on
ventricular systolic function and repolarization, suggesting that the extent of
viable myocardium may determine ventricular repolarization. METHODS: Seventy five
patients with previous myocardial infarction were studied in a low dose (up to 20
microg(-1) x kg(-1) x min(-1)) dobutamine stress echocardiography study. ECGs
were obtained at rest and peak stress for measurement of QT intervals. The
presence of ventricular arrhythmias (Lown grade >lb) during stress was noted. A
reduction in the total wall motion score of the left ventricle at peak stress
confirmed the presence of myocardial viability. RESULTS: Dobutamine infusion
increased QT dispersion in all patients (P<0.01). Patients with myocardial
viability had a lower resting QT dispersion (P<0.05) and a greater increase in QT
dispersion% (P<0.01) than patients without. The combination of a resting QT
dispersion <65 ms or an increase in QT dispersion >30% predicted viability with a
sensitivity of 67%, a specificity of 96%, and an accuracy of 78%. A patent
infarct-related artery, as well as ventricular arrhythmias, were more commonly
observed in patients with evidence of viable myocardium (P<0.05). Patients with
arrhythmias had a higher QT dispersion than patients without (P<0.05).
CONCLUSION: The combination of a resting QT dispersion +/-65 ms or an increase in
QT dispersion >30% predicts the presence of viable myocardium and thus, may
represent a simple index for the assessment of viability in everyday clinical
practice. Myocardial viability is related to a patent coronary artery and to a
high incidence of arrhythmias accompanied by a greater increase in QT dispersion
at peak dobutamine infusion.
PMID- 10681486
TI - Randomized comparative trial of triflusal and aspirin following acute myocardial
infarction.
AB - AIMS: To compare the efficacy and tolerability of the antiplatelet agent
triflusal with aspirin in the prevention of cardiovascular events following acute
myocardial infarction. METHODS AND RESULTS: In this double-blind, multicentre,
sequential design study, patients were randomized within 24 h of acute myocardial
infarction symptom onset to receive triflusal 600 mg or aspirin 300 mg once daily
for 35 days. The primary end-point was death, non-fatal myocardial reinfarction
or a non-fatal cerebrovascular event. The incidences of these individual outcomes
and urgent revascularization were secondary end-points. The null hypothesis of no
difference between treatments in the primary combined end-point was accepted with
80% power after recruiting 2124 validated patients (odds ratio (OR) for failure
[95% confidence interval (CI)]: 0.882 [0.634-1.227]). Non-fatal cerebrovascular
events were significantly less frequent with triflusal (OR [95% CI]: 0.364 [0.146
0.908]; P = 0.030). There was no significant difference between treatments for
death (OR [95% CI]: 0.816 [0.564-1.179]; P = 0.278), non-fatal reinfarction (OR
[95% CI]: 1.577 [0.873-2.848]; P = 0.131) or revascularization (OR [95% CI]:
0.864 [0.644-1.161]; P = 0.334). Overall, both drugs were well tolerated,
although there was a trend towards fewer bleeding episodes with triflusal;
significantly fewer central nervous system bleeding episodes were observed in
triflusal-treated patients (0.27% vs. 0.97%; P = 0.033). CONCLUSION: Triflusal
and aspirin have similar efficacy in preventing further cardiovascular events
after acute myocardial infarction, but triflusal showed a more favourable safety
profile. Triflusal significantly reduced the incidence of non-fatal
cerebrovascular events compared with aspirin.
PMID- 10681487
TI - Angiographical and Doppler flow-derived parameters for assessment of coronary
lesion severity and its relation to the result of exercise electrocardiography.
DEBATE study group. Doppler Endpoints Balloon Angioplasty Trial Europe.
AB - AIMS: Evaluation of angiographical and intracoronary Doppler-derived parameters
of coronary stenosis severity. METHODS AND RESULTS: A total of 225 patients with
one-vessel disease were studied before PTCA and at 6 months follow-up. Exercise
electrocardiography was performed to document presence (n = 157) or absence (n =
138) of an ST segment shift (> or =0.1 mV). Intracoronary blood flow velocity
analysis was performed to determine the proximal/distal flow velocity ratio, the
distal diastolic/systolic flow velocity ratio and coronary flow velocity reserve.
Receiver operator characteristic curves were calculated to assess the predictive
value of these variables compared with the exercise test. The distal coronary
flow velocity reserve demonstrated the best linear correlation for both
percentage diameter stenosis and minimum lumen diameter (r = 0.67 and r = 0.66;
P<0.01), compared to the diastolic/systolic flow velocity ratio (r = 0.19 and r =
0.14; P<0.01) and the proximal/distal flow velocity ratio (r = 0.03 and r = 0.07;
not significant). The areas under the curve were 0. 84+/-0.02; 0.82+/-0.03 and
0.83+/-0.03 for diameter stenosis, minimum lumen diameter and coronary flow
velocity reserve, respectively. Logistic regression analysis revealed that the
percentage diameter stenosis or minimum lumen diameter and coronary flow velocity
reserve were independent predictors for the result of stress testing.
CONCLUSIONS: The distal coronary flow velocity reserve is the best intracoronary
Doppler parameter for evaluation of coronary narrowings. Angiographical estimates
of coronary lesion severity and distal coronary flow velocity reserve are good
and independent predictors for the assessment of functional severity of coronary
stenosis, emphasizing the complementary role of these parameters for clinical
decision making.
PMID- 10681488
TI - Depressed low frequency power of heart rate variability as an independent
predictor of sudden death in chronic heart failure.
AB - AIMS: Identification of patients with chronic heart failure at risk for sudden
death remains difficult. We sought to assess the prognostic value for all-cause
and sudden death of time and frequency domain measures of heart rate variability
in chronic heart failure. METHODS AND RESULTS: We prospectively enrolled 190
patients with chronic heart failure in sinus rhythm, mean age 61+/-12 years, 109
(57.4%) in NYHA class II and 81 (42.6%) in classes III or IV, mean cardiothoracic
ratio 57.6+/-6.4% and mean left ventricular ejection fraction 28.2+/-8.8%, 85
(45%) with ischaemic and 105 (55%) with idiopathic dilated cardiomyopathy. Time
and frequency domain measures of heart rate variability were obtained from 24 h
Holter ECG recordings, spectral measures were averaged for calculation of daytime
(1000h-1900h) and night-time (2300h-0600h) values. During follow-up (22+/-18
months), 55 patients died, 21 of them suddenly and two presented with a syncopal
spontaneous sustained ventricular tachycardia. In multivariate analysis,
independent predictors for all-cause mortality were: ischaemic heart disease,
cardiothoracic ratio > or =60% and standard deviation of all normal RR intervals
<67 ms (RR = 2.5, 95% CI 1.5-4.2). Independent predictors of sudden death were:
ischaemic heart disease and daytime low frequency power <3.3 ln (ms(2)) (RR =
2.8, 95% CI 1.2-8.6). CONCLUSION: Depressed heart rate variability has
independent prognostic value in patients with chronic heart failure; spectral
analysis identifies an increased risk for sudden death in these patients.
PMID- 10681489
TI - Atrial right-to-left shunting causing severe hypoxaemia despite normal right
sided pressures. Report of 11 consecutive cases corrected by percutaneous
closure.
AB - BACKGROUND: Hypoxaemia resulting from a right-to-left shunt occurs in patients
with atrial septal defects and high pulmonary vascular resistance, but it is
uncommon without pulmonary hypertension. METHODS: We report on 11 consecutive
patients (age: 59-78 years) in whom a patent foramen ovale or a small atrial
septal defect with normal right-sided pressures led to significant cyanosis with
clinical symptoms. Six of them had associated platypnoea and orthodeoxia. The
diagnosis was confirmed by contrast transoesophageal echocardiography showing an
atrial right-to-left shunt. RESULTS: All but one were successfully treated by
percutaneous closure of the inter-atrial defect. In one patient, delivery of the
occluder failed due to kinking of the introducing sheath. Four complications were
observed following the procedure: two supraventricular arrhythmias and a
cerebrovascular accident, all resolved without sequelae; one patient died from a
septic shock unrelated to the procedure. During follow-up (up to 30 months), no
patient experienced any episode of desaturation due to inter-atrial shunting.
CONCLUSION: Cyanosis without pulmonary arterial hypertension in the adult should
prompt the performance of contrast transoesophageal echocardiography to identify
a possible atrial right-to-left shunt. Percutaneous closure of the defect allows
efficient and rapid correction of the hypoxaemia and avoids the need for surgical
closure.
PMID- 10681490
TI - Surgical treatment of active infective aortic valve endocarditis with associated
periannular abscess--11 year results.
AB - AIMS: The aim of the study was to evaluate the long-term results of allograft and
prosthetic valve replacement in the treatment of infective aortic valve
endocarditis with periannular abscess. METHODS: Between March 1988 and March
1996, 65 patients underwent surgery for active aortic valve endocarditis and
paravalvular abscess. The indications for surgery were congestive heart failure,
systemic emboli and atrioventricular block III. The pre-operative evaluation was
performed with transoesophageal echocardiography. Aortic valve replacement was
performed with allografts in 47 cases, with mechanical valves in 15, and
bioprosthetic valves in three cases. All patients with total ventricular-aortic
dehiscence and prosthetic valve endocarditis were treated with allografts.
RESULTS: The 30-day mortality rate was 23.5% in the prosthetic group, when
compared with 8.5% in the patients treated with allografts. The rate of recurrent
valve infections during the 11-year follow-up period was 27.1% in the prosthetic
group and 3.2% in the allograft group. The actuarial 11-year survival rate was
82.1% in the allograft group and 64.7% in the prosthetic group. CONCLUSION:
Aortic allografts are an effective treatment for infective aortic valve
endocarditis with associated periannular abscess. The operative mortality and
recurrent infection rates are lower than in the prosthetic group, resulting in a
significantly higher survival rate. Diagnosis and surgical management of these
cases should be based on pre-operative transoesophageal echocardiography.
PMID- 10681491
TI - Is the secretion of atrial natriuretic peptide in man under neural control?
AB - AIMS: Previous work has described short-term variation in the circulating plasma
level of atrial natriuretic peptide (ANP), but the mechanism remains unknown. Our
aim was to investigate the role of cardiac innervation in this variability.
METHODS AND RESULTS: Blood samples were obtained from the right atrium via a
pulmonary artery flotation catheter every 2 min over a 90 min period. Seven
patients who underwent cardiac transplantation by the standard biatrial technique
(partial innervation) and ten patients who underwent transplantation by the
bicaval technique (total denervation) were studied. ANP levels were measured by
radioimmunoassay. The median ANP levels were somewhat higher in the biatrial
group compared to the bicaval group [470 (150-1095) vs. 216 (100-605) pg. ml(-1);
median (range); P = ns], and both were much higher than normal levels in the
pulmonary artery (40 (24, 56) pg ml(-1); median and interquartile range). In both
transplant groups circulating plasma ANP levels showed considerable variability.
The median number of 'peaks' and 'troughs', as counted by visual inspection, were
not significantly different between the two groups. Computer analysis identified
12-16 and 6-15 'pulses' in the biatrial and bicaval group, respectively. Further
analysis revealed that pulse amplitude, height and area were significantly higher
in the biatrial compared to the bicaval group. CONCLUSION: It would appear that
variability of circulating plasma levels of ANP is preserved despite complete or
partial cardiac denervation, and so a neural mechanism does not appear to account
for such variation.
PMID- 10681493
TI - ESC news and appointments
PMID- 10681492
TI - ESC note from the publisher and the editor
PMID- 10681494
TI - Syndecan-4 deficiency impairs focal adhesion formation only under restricted
conditions.
AB - Two domains of fibronectin deliver two different but cooperative signals required
for focal adhesion formation. The signal from the cell-binding domain is mediated
by integrins, whereas the signal from the heparin-binding domain is recognized by
heparan sulfate proteoglycans, of which syndecan-4 has been hypothesized to be
involved in focal adhesion formation. We generated mice deficient in syndecan-4
to study its role directly. Even in fibroblasts from syndecan-4-deficient mice,
focal adhesions were formed, and actin fibers terminated normally at focal
adhesions when they were cultured on coverslips coated with fibronectin or with a
mixture of its cell-binding and heparin-binding fragments. However, when the
cells were cultured on the cell-binding fragment and the heparin-binding fragment
was added to the medium, focal adhesion formation was impaired in the syndecan-4
null fibroblasts as compared with that in wild-type cells. Therefore, syndecan-4
is essential for promoting focal adhesion formation only when the signal of the
heparin-binding domain of fibronectin is delivered as a soluble form, most
probably from the apical surface. When the signal is delivered as a substratum
bound form, other molecule(s) also participate(s) in the signal reception.
PMID- 10681495
TI - The packing of the transmembrane segments of human multidrug resistance P
glycoprotein is revealed by disulfide cross-linking analysis.
AB - Residues from several transmembrane (TM) segments of P-glycoprotein (P-gp) likely
form the drug-binding site(s). To determine the organization of the TM segments,
pairs of cysteine residues were introduced into the predicted TM segments of a
Cys-less P-gp, and the mutant protein was subjected to oxidative cross-linking.
In SDS gels, the cross-linked product migrated with a slower mobility than the
native protein. The cross-linked products were not detected in the presence of
dithiothreitol. Cross-linking was observed in 12 of 125 mutants. The pattern of
cross-linking suggested that TM6 is close to TMs 10, 11, and 12, while TM12 is
close to TMs 4, 5, and 6. In some mutants the presence of drug substrate
colchicine, verapamil, cyclosporin A, or vinblastine either enhanced or inhibited
cross-linking. Cross-linking was inhibited in the presence of ATP plus vanadate.
These results suggest that the TM segments critical for drug binding must be
close to each other and exhibit different conformational changes in response to
binding of drug substrate or vanadate trapping of nucleotide. Based on these
results, we propose a model for the arrangement of the TM segments.
PMID- 10681496
TI - WD40 repeat proteins striatin and S/G(2) nuclear autoantigen are members of a
novel family of calmodulin-binding proteins that associate with protein
phosphatase 2A.
AB - Protein phosphatase 2A (PP2A) is a multifunctional serine/threonine phosphatase
that is critical to many cellular processes including development, neuronal
signaling, cell cycle regulation, and viral transformation. PP2A has been
implicated in Ca(2+)-dependent signaling pathways, but how PP2A is targeted to
these pathways is not understood. We have identified two calmodulin (CaM)-binding
proteins that form stable complexes with the PP2A A/C heterodimer and may
represent a novel family of PP2A B-type subunits. These two proteins, striatin
and S/G(2) nuclear autoantigen (SG2NA), are highly related WD40 repeat proteins
of previously unknown function and distinct subcellular localizations. Striatin
has been reported to associate with the post-synaptic densities of neurons,
whereas SG2NA has been reported to be a nuclear protein expressed primarily
during the S and G(2) phases of the cell cycle. We show that SG2NA, like
striatin, binds to CaM in a Ca(2+)-dependent manner. In addition to CaM and PP2A,
several unidentified proteins stably associate with the striatin-PP2A and SG2NA
PP2A complexes. Thus, one mechanism of targeting and organizing PP2A with
components of Ca(2+)-dependent signaling pathways may be through the molecular
scaffolding proteins striatin and SG2NA.
PMID- 10681497
TI - An essential glutamyl residue in EmrE, a multidrug antiporter from Escherichia
coli.
AB - EmrE is an Escherichia coli 12-kDa protein that confers resistance to toxic
compounds, by actively removing them in exchange with protons. The protein
includes eight charged residues. Seven of these residues are located in the
hydrophilic loops and can be replaced with either Cys or another amino acid
bearing the same charge, without impairing transport activity. Glu-14 is the only
charged residue in the membrane domain and is conserved in all the proteins of
the family. We show here that this residue is the site of action of
dicyclohexylcarbodiimide, a carbodiimide known to act in hydrophobic
environments. When Glu-14 was replaced with either Cys or Asp, resistance was
abolished. Whereas the E14C mutant displays no transport activity, the E14D
protein shows efflux and exchange at rates about 30-50% that of the wild type.
The maximal DeltapH-driven uptake rate of E14D is only 10% that of the wild type.
The mutant shows a different pH profile in all the transport modes. Our results
support the notion that Glu-14 is an essential part of a binding domain shared by
substrates and protons but mutually exclusive in time. This notion provides the
molecular basis for the obligatory exchange catalyzed by EmrE.
PMID- 10681498
TI - Proximity of periplasmic loops in the metal-Tetracycline/H(+) antiporter of
Escherichia coli observed on site-directed chemical cross-linking.
AB - Our previous study on second-site suppressor mutations of the Tn10-encoded metal
tetracycline/H(+) antiporter suggested that Leu(30) and Ala(354), located in
periplasmic loop 1-2 and 11-12, respectively, are conformationally linked to each
other (Kawabe, T., and Yamaguchi, A. (1999) FEBS Lett. 457, 169-173). To
determine the spatial proximity of these two residues, cross-linking gel-shift
assays of the L30C/A354C double mutant were performed after the mutant had been
oxidized with Cu(2+)/o-phenanthroline. The results indicated that Leu(30) and
Ala(354) are close to each other but that Gly(62), which is located in
cytoplasmic loop 2-3, and Ala(354) are distant from each other, as a negative
control. Then, a single Cys residue was introduced into each of the six
periplasmic loop regions (P1-P6), and eleven double mutants were constructed. Of
these eleven double Cys mutants, the L30C/A354C and L30C/T235C mutants showed a
mobility shift on oxidation, indicating that P1 is spatially close to P4 as well
as P6. In contrast, the other nine mutants, L30C/S92C, L30C/S156C, L30C/S296C,
S92C/S296C, S92C/T235C, S92C/A354C, S156C/T235C, S156C/S296C, and S156C/A354C,
showed no mobility shift under oxidized conditions on intramolecular cross
linking. The S92C and S296C mutants showed dimerization on intermolecular cross
linking, indicating that P2 and P5 are located at the periphery of the helix
bundle.
PMID- 10681499
TI - On the spatial organization of hemes and chlorophyll in cytochrome b(6)f. A
linear and circular dichroism study.
AB - The organization of chromophores in the cytochrome b(6) f from Chlamydomonas
reinhardtii has been studied spectroscopically. Linear dichroism (LD)
measurements, performed on the complex co-reconstituted into vesicles with
photosynthetic reaction centers as an internal standard, allow the determination
of the orientations of the chromophore with respect to the membrane plane. The
orientations of the b(H)- and b(L)-hemes are comparable to those determined
crystallographically on the cytochrome bc(1). The excitonic CD signal, resulting
from the interaction between b-hemes, is similar to that reported for the
cytochrome bc(1). LD and CD data are consistent with the differences between the
b(6) f and bc(1) leaving the orientation of the b-hemes unaffected. By contrast,
the LD data yield a different orientation for the heme f as compared either to
the heme c(1) in the crystallographic structures or to the heme f as studied by
electron paramagnetic resonance. This difference could either result from
incorrect assumptions regarding the orientations of the electronic transitions of
the f-heme or may point to the possibility of a redox-dependent movement of
cytochrome f. The chlorophyll a was observed in a well defined orientation,
further corroborating a specific binding site for it in the b(6) f complex.
PMID- 10681500
TI - Relative orientation of the hemes of the cytochrome bc(1) complexes from
Rhodobacter sphaeroides, Rhodospirillum rubrum, and beef heart mitochondria. A
linear dichroism study.
AB - The orientation of the chromophores in the cytochrome bc(1) of Rhodospirillum
rubrum, Rhodobacter sphaeroides, and beef heart mitochondria is reported. The
combination of redox-resolved absorption spectrophotometry and linear dichroism
experiments at low temperature allows the determination of the orientation of the
three hemes with respect to the membrane plane. The orientations of the b(H)-and
b(L)-hemes of the R. sphaeroides and beef heart mitochondrial complexes are
similar to those determined by crystallographic studies of the mitochondrial
cytochrome bc(1). On the other hand the orientations of the b-hemes of the R.
rubrum complex lead to the conclusion that the b(H)-heme is more perpendicular to
the membrane plane than the b(L)-heme. This could be explained by a specific
organization of the b-hemes due to subunit composition of the complex or,
alternatively, to a different spatial position of the heme transitions with
respect to the porphyrin macrocycle compared with the other complexes. Moreover,
our results demonstrate a different orientation of the heme c(1) of the three
studied complexes in comparison to crystallographic studies. This difference may
arise from the above hypothesis on the transitions of the heme or from
flexibility of this subunit in function of its redox state.
PMID- 10681501
TI - Interaction of endothelial and neuronal nitric-oxide synthases with the
bradykinin B2 receptor. Binding of an inhibitory peptide to the oxygenase domain
blocks uncoupled NADPH oxidation.
AB - Endothelial nitric-oxide synthase (type III) (eNOS) was reported to form an
inhibitory complex with the bradykinin receptor B2 (B2R) from which the enzyme is
released in an active form upon receptor activation (Ju, H., Venema, V. J.,
Marrero, M. B., and Venema, R. C. (1998) J. Biol. Chem. 273, 24025-24029). Using
a synthetic peptide derived from the known inhibitory sequence of the B2R
(residues 310-329) we studied the interaction of the receptor with purified eNOS
and neuronal nitric-oxide synthase (type I) (nNOS). The peptide inhibited
formation of L-citrulline by eNOS and nNOS with IC(50) values of 10.6 +/- 0.4
microM and 7.1 +/- 0.6 microM, respectively. Inhibition was not due to an
interference of the peptide with L-arginine or tetrahydrobiopterin binding. The
NADPH oxidase activity of nNOS measured in the absence of L-arginine was
inhibited by the peptide with an IC(50) of 3.7 +/- 0.6 microM, but the cytochrome
c reductase activity of the enzyme was much less susceptible to inhibition
(IC(50) >0.1 mM). Steady-state absorbance spectra of nNOS recorded during
uncoupled NADPH oxidation showed that the heme remained oxidized in the presence
of the synthetic peptide consisting of amino acids 310-329 of the B2R, whereas
the reduced oxyferrous heme complex was accumulated in its absence. These data
suggest that binding of the B2R 310-329 peptide blocks flavin to heme electron
transfer. Co-immunoprecipitation of B2R and nNOS from human embryonic kidney
cells stably transfected with human nNOS suggests that the B2R may functionally
interact with nNOS in vivo. This interaction of nNOS with the B2R may recruit the
enzyme to allow for the effective coupling of bradykinin signaling to the nitric
oxide pathway.
PMID- 10681502
TI - Reaction intermediates and single turnover rate constants for the oxidation of
heme by human heme oxygenase-1.
AB - Heme oxygenase converts heme to biliverdin, iron, and CO in a reaction with two
established intermediates, alpha-meso-hydroxyheme and verdoheme. Transient
kinetic studies show that the conversion of Fe(3+)-heme to Fe(3+)-verdoheme is
biphasic. Electron transfer to the heme (0.11 s(-1) at 4 degrees C and 0.49 s(-1)
at 25 degrees C) followed by rapid O(2) binding yields the ferrous dioxy complex.
Transfer of an electron (0.056 s(-1) at 4 degrees C and 0.21 s(-1) at 25 degrees
C) to this complex triggers the formation of alpha-meso-hydroxyheme and its
subsequent O(2)-dependent fragmentation to Fe(3+)-verdoheme. The conversion of
Fe(3+)-verdoheme to Fe(3+)-biliverdin is also biphasic. Thus, reduction of Fe(3+)
to Fe(2+)-verdoheme (0.15 s(-1) at 4 degrees C and 0.55 s(-1) at 25 degrees C)
followed by O(2) binding and an electron transfer produces Fe(3+)-biliverdin
(0.025 s(-1) at 4 degrees C and 0.10 s(-1) at 25 degrees C). The conversion of
Fe(3+)-biliverdin to free biliverdin is triphasic. Reduction of Fe(3+)-biliverdin
(0.035 s(-1) at 4 degrees C and 0.15 s(-1) at 25 degrees C), followed by rapid
release of Fe(2+) (0.19 s(-1) at 4 degrees C and 0.39 s(-1) at 25 degrees C),
yields the biliverdin-enzyme complex from which biliverdin slowly dissociates
(0.007 s(-1) at 4 degrees C and 0.03 s(-1) at 25 degrees C). The rate of Fe(2+)
release agrees with the rate of Fe(3+)-biliverdin reduction. Fe(2+) release
clearly precedes biliverdin dissociation. In the absence of biliverdin reductase,
biliverdin release is the rate-limiting step, but in its presence biliverdin
release is accelerated and the overall rate of heme degradation is limited by the
conversion of Fe(2+)-verdoheme to the Fe(3+)-biliverdin.
PMID- 10681503
TI - Cloning and characterization of RAP250, a novel nuclear receptor coactivator.
AB - Ligand-induced transcriptional activation of gene expression by nuclear receptors
is dependent on recruitment of coactivators as intermediary factors. The present
work describes the cloning and characterization of RAP250, a novel human nuclear
receptor coactivator. The results of in vitro and in vivo experiments indicate
that the interaction of RAP250 with nuclear receptors is ligand-dependent or
ligand-enhanced depending on the nuclear receptor and involves only one short
LXXLL motif called nuclear receptor box. Transient transfection assays further
demonstrate that RAP250 has a large intrinsic glutamine-rich activation domain
and can significantly enhance the transcriptional activity of several nuclear
receptors, acting as a coactivator. Interestingly, Northern blot and in situ
hybridization analyses reveal that RAP250 is widely expressed with the highest
expression in reproductive organs (testis, prostate and ovary) and brain.
Together, our data suggest that RAP250 may play an important role in mammalian
gene expression mediated by nuclear receptor.
PMID- 10681504
TI - The acidic triad conserved in type IA DNA topoisomerases is required for binding
of Mg(II) and subsequent conformational change.
AB - The acidic residues Asp-111, Asp-113, and Glu-115 of Escherichia coli DNA
topoisomerase I are located near the active site Tyr-319 and are conserved in
type IA topoisomerase sequences with counterparts in type IIA DNA topoisomerases.
Their exact functional roles in catalysis have not been clearly defined. Mutant
enzymes with two or more of these residues converted to alanines were found to
have >90% loss of activity in the relaxation assay with 6 mM Mg(II) present.
Mg(II) concentrations (15-20 mM) inhibitory for the wild type enzyme are needed
by these double mutants for maximal relaxation activity. The triple mutant
D111A/D113A/E115A had no detectable relaxation activity. Mg(II) binding to wild
type enzyme resulted in an altered conformation detectable by Glu-C proteolytic
digestion. This conformational change was not observed for the triple mutant or
for the double mutant D111A/D113A. Direct measurement of Mg(II) bound showed the
loss of 1-2 Mg(II) ions for each enzyme molecule due to the mutations. These
results demonstrate a functional role for these acidic residues in the binding of
Mg(II) to induce the conformational change required for the relaxation of
supercoiled DNA by the enzyme.
PMID- 10681505
TI - 5'-nicked apurinic/apyrimidinic sites are resistant to beta-elimination by beta
polymerase and are persistent in human cultured cells after oxidative stress.
AB - Genomic DNA is continuously exposed to oxidative stress. Whereas reactive oxygen
species (ROS) preferentially react with bases in DNA, free radicals also abstract
hydrogen atoms from deoxyribose, resulting in the formation of
apurinic/apyrimidinic (AP) sites and strand breaks. We recently reported high
steady-state levels of AP sites in rat tissues and human liver DNA (Nakamura, J.,
and Swenberg, J. A. (1999) Cancer Res. 59, 2522-2526). These AP sites were
predominantly cleaved 5' to the lesion. We hypothesized that these endogenous AP
sites were derived from oxidative stress. In this investigation, AP sites induced
by ROS were quantitated and characterized. A combination of H(2)O(2) and FeSO(4)
induced significant numbers of AP sites in calf thymus DNA, which were
predominantly cleaved 5' to the AP sites (75% of total aldehydic AP sites). An
increase in the number of 5'-AP sites was also detected in human cultured cells
exposed to H(2)O(2), and these 5'-AP sites were persistent during the post
exposure period. beta-Elimination by DNA beta-polymerase efficiently excised 5'
regular AP sites, but not 5'-AP sites, in DNA from cells exposed to H(2)O(2).
These results suggest that 5'-oxidized AP sites induced by ROS are not
efficiently repaired by the mammalian short patch base excision repair pathway.
PMID- 10681506
TI - Poliovirus RNA-dependent RNA polymerase (3D(pol)). Assembly of stable, elongation
competent complexes by using a symmetrical primer-template substrate (sym/sub).
AB - Detailed studies of the kinetics and mechanism of nucleotide incorporation
catalyzed by the RNA-dependent RNA polymerase from poliovirus, 3D(pol), have been
limited by the inability to assemble elongation complexes that permit activity to
be monitored by extension of end-labeled primers. We have solved this problem by
employing a short, symmetrical, heteropolymeric RNA primer-template that we refer
to as "sym/sub." Formation of 3D(pol)-sym/sub complexes is slow owing to a slow
rate of association (0.1 microM(-1) s(-1)) of 3D(pol) and sym/sub and a slow
isomerization (0. 076 s(-1)) of the 3D(pol)-sym/sub complex that is a
prerequisite for catalytic competence of this complex. Complex assembly is
stoichiometric under conditions in which competing reactions, such as enzyme
inactivation, are eliminated. Inactivation of 3D(pol) occurs at a maximal rate of
0.051 s(-1) at 22 degrees C in reaction buffer lacking nucleotide. At this
temperature, ATP protects 3D(pol) against inactivation with a K(0.5) of 37
microM. Once formed, 3D(pol)-sym/sub elongation complexes are stable (t((1)/(2))
= 2 h at 22 degrees C) and appear to contain only a single polymerase monomer. In
the presence of Mg(2+), AMP, 2'-dAMP, and 3'-dAMP are incorporated into sym/sub
by 3D(pol) at rates of 72, 0.6, and 1 s(-1), respectively. After incorporation of
AMP, 3D(pol)-sym/sub product complexes have a half-life of 8 h at 22 degrees C.
The stability of 3D(pol)-sym/sub complexes is temperature-dependent. At 30
degrees C, there is a 2-8-fold decrease in complex stability. Complex
dissociation is the rate-limiting step for primer utilization. 3D(pol)
dissociates from the end of template at a rate 10-fold faster than from internal
positions. The sym/sub system will facilitate mechanistic analysis of 3D(pol) and
permit a direct kinetic and thermodynamic comparison of the RNA-dependent RNA
polymerase to the other classes of nucleic acid polymerases.
PMID- 10681507
TI - Kv4.2 phosphorylation by cyclic AMP-dependent protein kinase.
AB - Recent evidence suggests that K(+) channels composed of Kv4.2 alpha-subunits
underlie a transient current in hippocampal CA1 neurons and ventricular myocytes,
and activation of the cAMP second messenger cascade has been shown to modulate
this transient current. We determined if Kv4.2 alpha-subunits were directly
phosphorylated by cAMP-dependent protein kinase (PKA). The intracellular domains
of the amino and carboxyl termini of Kv4.2 were expressed as glutathione S
transferase fusion protein constructs; we observed that both of these fusion
proteins were substrates for PKA in vitro. By using phosphopeptide mapping and
amino acid sequencing, we identified PKA phosphorylation sites on the amino- and
carboxyl-terminal fusion proteins corresponding to Thr(38) and Ser(552),
respectively, within the Kv4.2 sequence. Kinetic characterization of the PKA
sites demonstrated phosphorylation kinetics comparable to Kemptide. To evaluate
PKA site phosphorylation in situ, phospho-selective antisera for each of the
sites were generated. By using COS-7 cells expressing an EGFP-Kv4.2 fusion
protein, we observed that stimulation of the endogenous PKA cascade resulted in
an increase in phosphorylation of Thr(38) and Ser(552) within Kv4.2 in the intact
cell. We also observed modulation of PKA phosphorylation at these sites within
Kv4.2 in hippocampal area CA1. These results provide insight into likely sites of
regulation of Kv4.2 by PKA.
PMID- 10681508
TI - TA1/LAT-1/CD98 light chain and system L activity, but not 4F2/CD98 heavy chain,
respond to arginine availability in rat hepatic cells. Loss Of response in tumor
cells.
AB - Tumor associated gene-1/L amino acid transporter-1 (TA1/LAT-1) was recently
identified as a light chain of the CD98 amino acid transporter and cellular
activation marker. Our previous studies with primary rat hepatocyte cultures
demonstrated that TA1 RNA levels were responsive to media amino acid
concentrations, suggesting adaptive regulation. High level TA1 expression
associated with transformed cells also suggested a role in tumor progression. The
present study examined the relationship of TA1/CD98 expression, adaptive
response, and associated amino acid transport to neoplastic transformation using
a panel of well characterized rat hepatic cell lines. We found 1) increased
expression of TA1 in response to amino acid depletion, specific for arginine but
not glutamine; 2) loss of TA1 response to arginine in gamma-glutamyl
transpeptidase-positive transformed and tumorigenic cells; 3) no appreciable
response of 4F2/CD98 heavy chain to arginine levels; and 4) correlation of system
L amino acid transport activity in response to arginine with changes in TA1/LAT-1
mRNA but not total immunoreacting protein. Our results suggest this CD98 light
chain may act as an environmental sensor, responding to amino acid availability
and that its regulation is complex. We hypothesize that altered TA1 expression is
an early event in hepatocarcinogenesis giving neoplastic cells a growth or
survival advantage, particularly under conditions of limited amino acid
availability.
PMID- 10681509
TI - Effect of ethanol and osmotic stress on receptor conformation. Reduced water
activity amplifies the effect of ethanol on metarhodopsin II formation.
AB - The combined effects of ethanol and osmolytes on both the extent of formation of
metarhodopsin II (MII), which binds and activates transducin, and on acyl chain
packing were examined in rod outer segment disc membranes. The ethanol-induced
increase in MII formation was amplified by the addition of neutral osmolytes.
This enhancement was linear with osmolality. At 360 milliosmolal, the osmolality
of human plasma, 50 mM ethanol was 2.7 times more potent than at 0 osmolality,
demonstrating the importance of water activity in in vitro experiments dealing
with ethanol potency. Ethanol disordered acyl chain packing, and increasing
osmolality enhanced this acyl chain disordering. Prior osmotic stress data showed
a release of 35 +/- 2 water molecules upon MII formation. Ethanol increases this
number to 49 water molecules, suggesting that ethanol replaces 15 additional
water molecules upon MII formation. Amplification of ethanol effects on MII
formation and acyl chain packing by osmolytes suggests that ethanol increases the
equilibrium concentration of MII both by disordering acyl chain packing and by
disrupting rhodopsin-water hydrogen bonds, demonstrating a direct effect of
ethanol on rhodopsin. At physiologically relevant levels of osmolality and
ethanol, about 90% of ethanol's effect is due to disordered acyl chain packing.
PMID- 10681510
TI - Phosphoinositide 3-kinase is involved in the tumor-specific activation of human
breast cancer cell Na(+)/H(+) exchange, motility, and invasion induced by serum
deprivation.
AB - Whereas the tumor acidic extracellular pH plays a crucial role in the invasive
process, the mechanism(s) behind this acidification, especially in low nutrient
conditions, are unclear. The regulation of the Na(+)/H(+) exchanger (NHE) and
invasion by serum deprivation were studied in a series of breast epithelial cell
lines representing progression from non-tumor to highly metastatic cells. Whereas
serum deprivation reduced lactate production in all three cells lines, it
inhibited NHE activity in the non-tumor cells and stimulated it in the tumor
cells with a larger stimulation in the metastatic cells. The stimulation of NHE
in the tumor cell lines was the result of an increased affinity of the internal
H(+) regulatory site of the NHE without changes in sodium kinetics or expression.
Serum deprivation conferred increased cell motility and invasive ability that
were abrogated by specific inhibition of the NHE. Inhibition of phosphoinositide
3-kinase by overexpression of a dominant-negative mutant or wortmannin incubation
inhibited NHE activity and invasion in serum replete conditions while
potentiating the serum deprivation-dependent activation of the NHE and invasion.
These results indicate that the up-regulation of the NHE by a phosphoinositide 3
kinase-dependent mechanism plays an essential role in increased tumor cell
invasion induced by serum deprivation.
PMID- 10681511
TI - Disulfide-mediated oligomerization of Peripherin/Rds and Rom-1 in photoreceptor
disk membranes. Implications for photoreceptor outer segment morphogenesis and
degeneration.
AB - Peripherin/Rds is a tetraspanning membrane protein that has been implicated in
photoreceptor outer segment morphogenesis and inherited retinal degenerative
diseases. Together with the structurally related protein, Rom-1, it forms a
complex along the rims of rod and cone disc membranes. We have compared the
oligomeric structure of these proteins from nonreduced and dithiothreitol reduced
membranes by velocity sedimentation, SDS-gel electrophoresis, immunoaffinity
chromatography, and chemical cross-linking. Under reducing conditions
peripherin/Rds and Rom-1 existed as homomeric and heteromeric core complexes
devoid of intermolecular disulfide bonds. Under nonreducing conditions core
complexes associated through intermolecular disulfide bonds to form oligomers.
One intermediate-size oligomer contained monomers and disulfide-linked dimers of
peripherin/Rds and Rom-1, while larger oligomers consisted only of disulfide
linked peripherin/Rds dimers when analyzed on nonreducing SDS gels. Consistent
with this result, disc membranes contained twice as much peripherin/Rds as Rom-1.
Peripherin/Rds individually expressed in COS-1 cells also formed disulfide-linked
oligomers bridged through Cys-150 residues, whereas Rom-1 showed little tendency
to form oligomers. These results indicate that peripherin/Rds and Rom-1 associate
noncovalently to form multisubunit core complexes. Peripherin/Rds containing core
complexes interact through specific intermolecular disulfide bonds to form
oligomers which may play a crucial role in photoreceptor disc morphogenesis and
retinal degenerative diseases.
PMID- 10681512
TI - Ligand-, cell-, and estrogen receptor subtype (alpha/beta)-dependent activation
at GC-rich (Sp1) promoter elements.
AB - 17beta-Estradiol (E2) induces expression of several genes via estrogen receptor
(ER)-Sp1 protein interactions with GC-rich promoter elements in which Sp1 but not
ER binds DNA. This study reports the ligand- and cell context-dependent
ER(alpha)/Sp1 and ER(beta)/Sp1 action using an E2-responsive construct (pSp1)
containing a GC-rich promoter. Both ER(alpha) and ER(beta) proteins physically
interact with Sp1 (coimmunoprecipitation) and preferentially bind to the C
terminal region of this protein in pull-down assays. E2- and antiestrogen
dependent transcriptional activation of ER(alpha)/Sp1 was observed in MCF-7, MDA
MB-231, and LnCaP cells, but not in HeLa cells. E2 did not affect or
significantly decrease ER(beta)/Sp1 action, and antiestrogens had minimal effects
in the same 4 cell lines. Exchange of activation function-1 (AF-1) domains of ER
subtypes gave chimeric ER(alpha/beta) (AF-1alpha/AF-2beta) and ER(beta/alpha) (AF
1beta/AF-2alpha) proteins that resembled wild-type ER (alpha or beta) in terms of
physical association with Sp1 protein. Transcriptional activation studies with
chimeric ER(beta/alpha) and ER(alpha/beta) showed that only ER(alpha/beta) can
activate transcription from an Sp1 element, not ER(beta/alpha). This indicates
that the AF-1 domain from ER(alpha) is responsible for activation at an Sp1
element, independent of ER subtype context. In order to further characterize this
observation, deletion constructs in the AF-1 domain of both ER(alpha) and
ER(alpha/beta) were made, and transactivation studies indicated that the region
between amino acids 79 and 117 of this domain is important for activation at an
Sp1 element.
PMID- 10681513
TI - Nerve growth factor cooperates with p185(HER2) in activating growth of human
breast carcinoma cells.
AB - Nerve growth factor (NGF) is known to exert a mitogenic effect on human breast
cancer cells through proto-TrkA activation. Reverse transcriptase-PCR analysis of
proto-TrkA expression in human breast carcinoma specimens and cell lines revealed
trkA transcript in 12 of 14 human breast carcinoma specimens and in all of four
cell lines tested. While cytofluorimetric and Western blot analysis indicated
proto-TrkA expression in three of the four cell lines, NGF stimulated growth in
only two of the three positive cell lines. Inhibition of NGF-induced MAPK
activation by an antibody directed against the extracellular domain of TrkA but
not by an inhibitor of TrkA phosphorylation demonstrated the requirement of NGF
binding but not of proto-TrkA kinase activity for MAPK activation, suggesting the
recruitment of another kinase for transmission of the mitogenic signaling.
Indeed, NGF induced tyrosine phosphorylation and stimulated kinase activity of
p185(HER2), a kinase receptor of the HER family. A TrkA phosphorylation inhibitor
did not affect this activation. Moreover, the two receptors were coprecipitated
by antibodies directed against proto-TrkA and p185(HER2). Down-modulation of
p185(HER2) expression in a breast carcinoma line transfected with a construct
containing an anti-p185(HER2) antibody sequence and expressing proto-TrkA
impaired NGF-induced MAPK activation and proliferation. Together these data show
that in cells expressing low levels of TrkA such as breast carcinoma cells, NGF
must recruit other overexpressed receptors such as p185(HER2) in order to
generate a biological signal that can induce breast cancer cell growth.
PMID- 10681514
TI - Overexpression of heme oxygenase in neuronal cells, the possible interaction with
Tau.
AB - Increased expression of heme oxygenase-1 (HO-1) is a common feature in a number
of neurodegenerative diseases. Interestingly, the spatial distribution of HO-1
expression in diseased brain is essentially identical to that of pathological
expression of tau. In this study, we explored the relationship between HO-1 and
tau, using neuroblastoma cells stably transfected with sense and antisense HO-1
constructs as well as with the vector alone. In transfected cells overexpressing
HO-1, the activity of heme oxygenase was increased, and conversely, the level of
tau protein was dramatically decreased when compared with antisense HO-1 or CEP
transfected cells. The suppression of tau protein expression was almost
completely reversed by zinc-deuteroporphyrin, a specific inhibitor of heme
oxygenase activity. The activated forms of ERKs (extracellular signal-regulated
kinases) were also decreased in cells overexpressing HO-1 although no changes in
the expression of total ERK-1/2 proteins were observed. These data are in
agreement with the finding that the expression of tau is regulated through signal
cascades including the ERKs, whose activities are modulated by oxidative
stresses. The expression of tau and HO-1 may be regulated by oxidative stresses
in a coordinated manner and play a pivotal role in the cytoprotection of neuronal
cells.
PMID- 10681515
TI - Fast kinetic analysis of conformational changes in mutants of the Ca(2+)-ATPase
of sarcoplasmic reticulum.
AB - Rapid quench experiments at 25 degrees C were carried out on selected mutants of
the sarco(endo)plasmic reticulum Ca(2+)-ATPase to assess the kinetics of the
conformational changes of the dephosphoenzyme associated with ATP
binding/phosphoryl transfer and the binding and dissociation of Ca(2+) at the
cytoplasmically facing transport sites. The mutants Gly(233) --> Glu, Gly(233) -
> Val, Pro(312) --> Ala, Leu(319) --> Arg, and Lys(684) --> Arg differed
conspicuously with respect to the behavior of the dephosphoenzyme, although they
were previously shown to display a common block of the transformation of the
phosphoenzyme from an ADP-sensitive to an ADP-insensitive form. The maximum rate
of the ATP binding/phosphoryl transfer reaction was reduced 3.6-fold in mutant
Gly(233) --> Glu and more than 50-fold in mutant Lys(684) --> Arg, relative to
wild type. In mutant Leu(319) --> Arg, the rate of the Ca(2+)-binding transition
was reduced as much as 10-30-fold depending on the presence of ATP. In mutants
Gly(233) --> Glu, Gly(233) --> Val, and Pro(312) --> Ala, the rate of the Ca(2+)
binding transition was increased at least 2-3-fold at acid pH but not
significantly at neutral pH, suggesting a destabilization of the protonated form.
The rate of Ca(2+) dissociation was reduced 12-fold in mutant Pro(312) --> Ala
and 3.5-fold in Leu(319) --> Arg, and increased at least 4-fold in a mutant in
which the putative Ca(2+) liganding residue Glu(309) was replaced by aspartate.
The data support a model in which Pro(312) and Leu(319) are closely associated
with the cation binding pocket, Gly(233) is part of a long-range signal
transmission pathway between the ion-binding sites and the catalytic site, and
Lys(684) is an essential catalytic residue that may function in the same way as
its counterpart in the soluble hydrolases belonging to the haloacid dehalogenase
superfamily.
PMID- 10681516
TI - Mammalian 5'(3')-deoxyribonucleotidase, cDNA cloning, and overexpression of the
enzyme in Escherichia coli and mammalian cells.
AB - 5'(3')-Deoxyribonucleotidase is a ubiquitous enzyme in mammalian cells whose
physiological function is not known. It was earlier purified to homogeneity from
human placenta. We determined the amino acid sequences of several internal
peptides and with their aid found an expressed sequence tag clone with the
complete cDNA for a murine enzyme of 23.9 kDa. The DNA was cloned into
appropriate plasmids and introduced into Escherichia coli and ecdyson-inducible
293 and V79 cells. The recombinant enzyme was purified to homogeneity from
transformed E. coli and was found to be identical with the native enzyme. After
induction with ponasterone, the transfected mammalian cells showed a gradual
increase of enzyme activity. A human expressed sequence tag clone contained a
large part of the cDNA of the human enzyme but lacked the 5'-end corresponding to
51 amino acids of the murine enzyme. Several polymerase chain reaction-based
approaches to find this sequence met with no success. A mouse/human hybrid cDNA
that had substituted the missing human 5'-end with the corresponding mouse
sequence coded for a fully active enzyme.
PMID- 10681517
TI - NAD(P)H:Quinone oxidoreductase activity is the principal determinant of beta
lapachone cytotoxicity.
AB - beta-Lapachone activates a novel apoptotic response in a number of cell lines. We
demonstrate that the enzyme NAD(P)H:quinone oxidoreductase (NQO1) substantially
enhances the toxicity of beta-lapachone. NQO1 expression directly correlated with
sensitivity to a 4-h pulse of beta-lapachone in a panel of breast cancer cell
lines, and the NQO1 inhibitor, dicoumarol, significantly protected NQO1
expressing cells from all aspects of beta-lapachone toxicity. Stable transfection
of the NQO1-deficient cell line, MDA-MB-468, with an NQO1 expression plasmid
increased apoptotic responses and lethality after beta-lapachone exposure.
Dicoumarol blocked both the apoptotic responses and lethality. Biochemical
studies suggest that reduction of beta-lapachone by NQO1 leads to a futile
cycling between the quinone and hydroquinone forms, with a concomitant loss of
reduced NAD(P)H. In addition, the activation of a cysteine protease, which has
characteristics consistent with the neutral calcium-dependent protease, calpain,
is observed after beta-lapachone treatment. This is the first definitive
elucidation of an intracellular target for beta-lapachone in tumor cells. NQO1
could be exploited for gene therapy, radiotherapy, and/or chemopreventive
interventions, since the enzyme is elevated in a number of tumor types (i.e.
breast and lung) and during neoplastic transformation.
PMID- 10681518
TI - Nitric oxide modulates the catalytic activity of myeloperoxidase.
AB - Myeloperoxidase (MPO), an abundant protein in neutrophils, monocytes, and
subpopulations of tissue macrophages, is believed to play a critical role in host
defenses and inflammatory tissue injury. To perform these functions, an array of
diffusible radicals and reactive oxidant species may be formed through oxidation
reactions catalyzed at the heme center of the enzyme. Myeloperoxidase and
inducible nitric-oxide synthase are both stored in and secreted from the primary
granules of activated leukocytes, and nitric oxide (nitrogen monoxide; NO) reacts
with the iron center of hemeproteins at near diffusion-controlled rates. We now
demonstrate that NO modulates the catalytic activity of MPO through distinct
mechanisms. NO binds to both ferric (Fe(III), the catalytically active species)
and ferrous (Fe(II)) forms of MPO, generating stable low-spin six-coordinate
complexes, MPO-Fe(III).NO and MPO-Fe(II).NO, respectively. These nitrosyl
complexes were spectrally distinguishable by their Soret absorbance peak and
visible spectra. Stopped-flow kinetic analyses indicated that NO binds reversibly
to both Fe(III) and Fe(II) forms of MPO through simple one-step mechanisms. The
association rate constant for NO binding to MPO-Fe(III) was comparable to that
observed with other hemoproteins whose activities are thought to be modulated by
NO in vivo. In stark contrast, the association rate constant for NO binding to
the reduced form of MPO, MPO-Fe(II), was over an order of magnitude slower.
Similarly, a 2-fold decrease was observed in the NO dissociation rate constant of
the reduced versus native form of MPO. The lower NO association and dissociation
rates observed suggest a remarkable conformational change that alters the
affinity and accessibility of NO to the distal heme pocket of the enzyme
following heme reduction. Incubation of NO with the active species of MPO
(Fe(III) form) influenced peroxidase catalytic activity by dual mechanisms. Low
levels of NO enhanced peroxidase activity through an effect on the rate-limiting
step in catalysis, reduction of Compound II to the ground-state Fe(III) form. In
contrast, higher levels of NO inhibited MPO catalysis through formation of the
nitrosyl complex MPO-Fe(III)-NO. NO interaction with MPO may thus serve as a
novel mechanism for modulating peroxidase catalytic activity, influencing the
regulation of local inflammatory and infectious events in vivo.
PMID- 10681519
TI - Loss of the major isoform of phosphoglucomutase results in altered calcium
homeostasis in Saccharomyces cerevisiae.
AB - Phosphoglucomutase (PGM) is a key enzyme in glucose metabolism, where it
catalyzes the interconversion of glucose 1-phosphate (Glc-1-P) and glucose 6
phosphate (Glc-6-P). In this study, we make the novel observation that PGM is
also involved in the regulation of cellular Ca(2+) homeostasis in Saccharomyces
cerevisiae. When a strain lacking the major isoform of PGM (pgm2Delta) was grown
on media containing galactose as sole carbon source, its rate of Ca(2+) uptake
was 5-fold higher than an isogenic wild-type strain. This increased rate of
Ca(2+) uptake resulted in a 9-fold increase in the steady-state total cellular
Ca(2+) level. The fraction of cellular Ca(2+) located in the exchangeable pool in
the pgm2Delta strain was found to be as large as the exchangeable fraction
observed in wild-type cells, suggesting that the depletion of Golgi Ca(2+) stores
is not responsible for the increased rate of Ca(2+) uptake. We also found that
growth of the pgm2Delta strain on galactose media is inhibited by 10 microM
cyclosporin A, suggesting that activation of the calmodulin/calcineurin signaling
pathway is required to activate the Ca(2+) transporters that sequester the
increased cytosolic Ca(2+) load caused by this high rate of Ca(2+) uptake. We
propose that these Ca(2+)-related alterations are attributable to a reduced
metabolic flux between Glc-1-P and Glc-6-P due to a limitation of PGM enzymatic
activity in the pgm2Delta strain. Consistent with this hypothesis, we found that
this "metabolic bottleneck" resulted in an 8-fold increase in the Glc-1-P level
compared with the wild-type strain, while the Glc-6-P and ATP levels were normal.
These results suggest that Glc-1-P (or a related metabolite) may participate in
the control of Ca(2+) uptake from the environment.
PMID- 10681520
TI - Induction of rac-guanine nucleotide exchange activity of Ras-GRF1/CDC25(Mm)
following phosphorylation by the nonreceptor tyrosine kinase Src.
AB - Ras-GRF1/CDC25(Mm) has been implicated as a Ras-guanine nucleotide exchange
factor (GEF) expressed in brain. Ras-GEF activity of Ras-GRF1 is augmented in
response to Ca(2+) influx and G protein betagamma subunit (Gbetagamma)
stimulation. Ras-GRF1 also acts as a GEF toward Rac, but not Rho and Cdc42, when
activated by Gbetagamma-mediated signals. Tyrosine phosphorylation of Ras-GRF1 is
critical for the induction of Rac-GEF activity as evidenced by inhibition by
tyrosine kinase inhibitors. Herein, we show that the nonreceptor tyrosine kinase
Src phosphorylates Ras-GRF1, thereby inducing Rac-GEF activity. Ras-GRF1
transiently expressed with v-Src was tyrosine-phosphorylated and showed
significant GEF activity toward Rac, but not Rho and Cdc42, which was comparable
with that induced by Gbetagamma. In contrast, Ras-GEF activity remained
unchanged. The recombinant c-Src protein phosphorylated affinity-purified
glutathione S-transferase-tagged Ras-GRF1 in vitro and thereby elicited Rac-GEF
activity. Taken together, tyrosine phosphorylation by Src is sufficient for the
induction of Rac-GEF activity of Ras-GRF1, which may imply the involvement of Src
downstream of Gbetagamma to regulate Ras-GRF1.
PMID- 10681521
TI - Mechanisms by which soluble endothelial cell protein C receptor modulates protein
C and activated protein C function.
AB - The endothelial cell protein C receptor (EPCR) functions as an important
regulator of the protein C anticoagulant pathway by binding protein C and
enhancing activation by the thrombin-thrombomodulin complex. EPCR binds to both
protein C and activated protein C (APC) with high affinity. A soluble form of
EPCR (sEPCR) circulates in plasma and inhibits APC anticoagulant activity. In
this study, we investigate the mechanisms by which sEPCR modulates APC function.
Soluble EPCR inhibited the inactivation of factor Va by APC only in the presence
of phospholipid vesicles. By using flow cytometric analysis in the presence of 3
mM CaCl(2) and 0. 6 mM MgCl(2), sEPCR inhibited the binding of protein C and APC
to phospholipid vesicles (K(i) = 40 +/- 7 and 33 +/- 4 nM, respectively). Without
MgCl(2), the K(i) values increased approximately 4-fold. Double label flow
cytometric analysis using fluorescein-APC and Texas Red-sEPCR indicated that the
APC.sEPCR complex does not interact with phospholipid vesicles. By using surface
plasmon resonance, we found that sEPCR also inhibited binding of protein C to
phospholipid in a dose-dependent fashion (K(i) = 32 nM). To explore the
possibility that sEPCR evokes structural changes in APC, fluorescence
spectroscopy studies were performed to monitor sEPCR/Fl-APC interactions. sEPCR
binds saturably to Fl-APC (K(d) = 27 +/- 13 nM) with a maximum decrease in Fl-APC
fluorescence of 10.8 +/- 0.6%. sEPCR also stimulated the amidolytic activity of
APC toward synthetic substrates. We conclude that sEPCR binding to APC blocks
phospholipid interaction and alters the active site of APC.
PMID- 10681522
TI - Dissecting the interaction of SHP-2 with PZR, an immunoglobulin family protein
containing immunoreceptor tyrosine-based inhibitory motifs.
AB - Tyrosine phosphorylation of membrane proteins plays a crucial role in cell
signaling by recruiting Src homology 2 (SH2) domain-containing signaling
molecules. Recently, we have isolated a transmembrane protein designated PZR that
specifically binds tyrosine phosphatase SHP-2, which has two SH2 domains (Zhao,
Z. J., and Zhao, R. (1998) J. Biol. Chem. 273, 29367-29372). PZR belongs to the
immunoglobulin superfamily. Its intracellular segment contains four putative
sites of tyrosine phosphorylation. By site-specific mutagenesis, we found that
the tyrosine 241 and 263 embedded in the consensus immunoreceptor tyrosine-based
inhibitory motifs VIYAQL and VVYADI, respectively, accounted for the entire
tyrosine phosphorylation of PZR. The interaction between PZR and SHP-2 requires
involvement of both tyrosyl residues of the former and both SH2 domains of the
latter, since its was disrupted by mutating a single tyrosyl residue or an SH2
domain. Overexpression of catalytically inactive but not active forms of SHP-2
bearing intact SH2 domains in cells caused hyperphosphorylation of PZR. In vitro,
tyrosine-phosphorylated PZR was efficiently dephosphorylated by the full-length
form of SHP-2 but not by its SH2 domain-truncated form. Together, the data
indicate that PZR serves not only as a specific anchor protein of SHP-2 on the
plasma membrane but also as a physiological substrate of the enzyme. The
coexisting binding and dephosphorylation of PZR by SHP-2 may function to
terminate signal transduction initiated by PZR and SHP-2 and to set a threshold
for the signal transduction to be initiated.
PMID- 10681523
TI - alpha(1A) adrenergic receptor induces eukaryotic initiation factor 4E-binding
protein 1 phosphorylation via a Ca(2+)-dependent pathway independent of
phosphatidylinositol 3-kinase/Akt.
AB - Phosphorylation of the translation repressor eukaryotic initiation factor 4E
binding protein 1 (4E-BP1) is thought to be partly responsible for increased
protein synthesis induced by growth factors. This study investigated the effect
of a G(q)-coupled receptor on protein synthesis and the phosphorylation state and
function of 4E-BP1 in Rat-1 fibroblasts expressing the human alpha(1A) adrenergic
receptor. Treatment of cells with phenylephrine (PE), a specific alpha(1)
adrenergic receptor agonist, increased protein synthesis and induced the
phosphorylation of 4E-BP1 and its release from translation initiation factor 4E.
Although the PE-induced phosphorylation of 4E-BP1 was blocked by the
phosphatidylinositol 3-kinase inhibitor LY294002, neither phosphatidylinositol 3
kinase nor Akt, its downstream effector, is activated in cells treated with PE
(Ballou, L. M., Cross, M. E., Huang, S., McReynolds, E. M., Zhang, B. X., and
Lin, R. Z., J. Biol. Chem. 275, 4803-4809). The effect of PE on 4E-BP1
phosphorylation was also abolished in cells depleted of intracellular Ca(2+) and
in cells pretreated with calmodulin antagonists. By contrast, phosphorylation of
4E-BP1 still occurred in cells in which the Ca(2+)- and diacylglycerol-dependent
isoforms of protein kinase C were down-regulated by prolonged exposure to a
phorbol ester. We conclude that activation of the alpha(1A) adrenergic receptor
in Rat-1 fibroblasts leads to phosphorylation of 4E-BP1 via a pathway that is
Ca(2+)- and calmodulin-dependent. Phosphatidylinositol 3-kinase, Akt, and phorbol
ester-sensitive protein kinase C isoforms do not appear to be required in this
signaling pathway.
PMID- 10681524
TI - Human vascular smooth muscle cells possess functional CCR5.
AB - CC chemokine receptors are important modulators of inflammation. Although CC
chemokine receptors have been found predominantly on leukocytes, recent studies
have suggested that vascular smooth muscle cells respond to CC chemokines. We now
report that human smooth muscle cells express CCR5, a co-receptor for human
immunodeficiency virus. CCR5 mRNA was detectable by RNA blot hybridization in
human aortic and coronary artery smooth muscle cells. The cDNA generated by
reverse transcription-polymerase chain reaction from aortic smooth muscle cells
had 100% identity throughout the entire coding region with the CCR5 cloned from
THP-1 cells. By immunohistochemistry, CCR5 and the CCR5 ligand, macrophage
inflammatory protein-1beta (MIP-1beta), were detected in smooth muscle cells and
macrophages of the atherosclerotic plaque. In smooth muscle cell culture, MIP
1beta induced a significant increase in intracellular calcium concentrations,
which was blocked by an antibody to CCR5. In addition, MIP-1beta caused a calcium
dependent increase in tissue factor activity. Tissue factor is the initiator of
coagulation and is thought to play a key role in arterial thrombosis. These data
suggest that human arterial smooth muscle cells express functional CCR5 receptors
and MIP-1beta is an agonist for these cells.
PMID- 10681525
TI - Identification of the peptide-binding site in the heat shock chaperone/tumor
rejection antigen gp96 (Grp94).
AB - Heat shock protein (HSP)-peptide complexes from tumor cells elicit specific
protective immunity when injected into inbred mice bearing the same specific type
of tumor. The HSP-mediated specific immunogenicity also occurs with virus
infected cells. The immune response is solely due to endogenous peptides
noncovalently bound to HSP. A vesicular stomatitis virus capsid-derived peptide
ligand bearing a photoreactive azido group was specifically bound by and cross
linked to murine HSP glycoprotein (gp) 96. The peptide-binding site was mapped by
specific proteolysis of the cross-links followed by analysis of the cross-linked
peptides using a judicious combination of SDS-gel electrophoresis, mass
spectrometry, and amino acid sequencing. The minimal peptide-binding site was
mapped to amino acid residues 624-630 in a highly conserved region of gp96. A
model of the peptide binding pocket of gp96 was constructed based on the known
crystallographic structure of major histocompatibility complex class I molecule
bound to a similar peptide. The gp96-peptide model predicts that the peptide
ligand is held in a groove formed by alpha-helices and lies on a surface
consisting of antiparallel beta-sheets. Interestingly, in this model, the peptide
binding pocket abuts the dimerization domain of gp96, which may have implications
for the extraordinary stability of peptide-gp96 complexes, and for the faithful
relay of peptides to major histocompatibility complex class I molecule for
antigen presentation.
PMID- 10681526
TI - Pairwise electrostatic interactions between alpha-neurotoxins and gamma, delta,
and epsilon subunits of the nicotinic acetylcholine receptor.
AB - alpha-Neurotoxins bind with high affinity to alpha-gamma and alpha-delta subunit
interfaces of the nicotinic acetylcholine receptor. Since this high affinity
complex likely involves a van der Waals surface area of approximately 1200 A(2)
and 25-35 residues on the receptor surface, analysis of side chains should
delineate major interactions and the orientation of bound alpha-neurotoxin. Three
distinct regions on the gamma subunit, defined by Trp(55), Leu(119), Asp(174),
and Glu(176), contribute to alpha-toxin affinity. Of six charge reversal
mutations on the three loops of Naja mossambica mossambica alpha-toxin, Lys(27) -
> Glu, Arg(33) --> Glu, and Arg(36) --> Glu in loop II reduce binding energy
substantially, while mutations in loops I and III have little effect. Paired
residues were analyzed by thermodynamic mutant cycles to delineate electrostatic
linkages between the six alpha-toxin charge reversal mutations and three key
residues on the gamma subunit. Large coupling energies were found between Arg(33)
at the tip of loop II and gammaLeu(119) (-5.7 kcal/mol) and between Lys(27) and
gammaGlu(176) (-5.9 kcal/mol). gammaTrp(55) couples strongly to both Arg(33) and
Lys(27), whereas gammaAsp(174) couples minimally to charged alpha-toxin residues.
Arg(36), despite strong energetic contributions, does not partner with any gamma
subunit residues, perhaps indicating its proximity to the alpha subunit. By
analyzing cationic, neutral and anionic residues in the mutant cycles,
interactions at gamma176 and gamma119 can be distinguished from those at gamma55.
PMID- 10681527
TI - Identification and characterization of a PDZ protein that interacts with activin
type II receptors.
AB - We have identified a mouse PDZ protein that interacts with the activin type IIA
receptor (ActRIIA), which we named activin receptor-interacting protein 1
(ARIP1). By using yeast two-hybrid screening, we isolated a cDNA clone of ARIP1
from a mouse brain cDNA library. We detected two forms of ARIP1, ARIP1-long and
ARIP1-short, which may be produced by alternative splicing. ARIP1-long had one
guanylate kinase domain in the NH(2)-terminal region, followed by two WW domains
and five PDZ domains (PDZ1-5). ARIP1-short had a deletion in the NH(2)-terminal
region and lacked the guanylate kinase domain. Both forms interacted with ActRIIA
through PDZ5. The COOH-terminal residues of ActRIIA (ESSL) agree with a PDZ
binding consensus motif, and ARIP1 recognized the consensus sequence. ARIP1
interacts specifically with ActRIIA among the receptors for the transforming
growth factor beta family. Interestingly, ARIP1 also interacted with Smad3, which
is an activin/transforming growth factor beta intracellular signaling molecule.
The mRNA of ARIP1 was more abundant in the brain than in other tissues.
Overexpression of ARIP1 controls activin-induced and Smad3-induced transcription
in activin-responsive cell lines. These findings suggest that ARIP1 has a
significant role in assembling activin signaling molecules at specific
subcellular sites and in regulating signal transduction in neuronal cells.
PMID- 10681528
TI - Probing subunit interactions in alpha class rat liver glutathione S-transferase
with the photoaffinity label glutathionyl S-[4-(succinimidyl)benzophenone].
AB - Glutathionyl S-[4-(succinimidyl)benzophenone] (GS-Succ-BP), an analogue of the
product of glutathione and electrophilic substrate, acts as a photoaffinity label
of dimeric rat liver glutathione S-transferase (GST), isoenzyme 1-1. A time
dependent loss of enzyme activity is observed upon irradiation of the enzyme with
long wavelength UV light in the presence of the reagent. The initial rate of
inactivation exhibits nonlinear dependence on the concentration of the reagent,
characterized by an apparent dissociation constant of the enzyme-reagent complex
(K(R)) of 99 +/- 2 microM and k(max) of 0.082 +/- 0.005 min(-1). Protection
against this inactivation is provided by the electrophilic substrate (ethacrynic
acid), electrophilic substrate analogue (dinitrophenol), and product analogues (S
hexylglutathione and p-nitrobenzylglutathione) but not by steroids (Delta(5)
androstene-3,17-dione and 17beta-estradiol-3, 17-disulfate). These results
suggest that GS-Succ-BP binds and reacts with the enzyme within the xenobiotic
substrate binding site, and this reaction site is distinct from the substrate and
nonsubstrate steroid binding sites of the enzyme. About 1 mol of reagent is
incorporated into 1 mol of enzyme dimer when the enzyme is completely
inactivated. Met-208 is the only amino acid target of the reagent, and
modification of this residue in one enzyme subunit of the GST 1-1 dimer
completely abolishes the enzyme activity of both subunits. In order to evaluate
the role of subunit interactions in the Alpha class glutathione S-transferases,
inactive GS-Succ-BP-modified GST 1-1 was mixed with unlabeled, active GST 2-2.
The enzyme subunits were dissociated in dilute trifluoroacetic acid and then
renatured at pH 7.8 and separated by chromatofocusing into GST 1-1, 1-2, and 2-2.
The specific activities of the heterodimer toward several substrates indicate
that the loss of catalytic activity in the unmodified subunit of the modified GST
1-1 is the indirect result of the interaction between the two enzyme subunits and
that this subunit interaction is absent in the heterodimer GST 1-2.
PMID- 10681529
TI - Cysteine-rich protein 2, a novel substrate for cGMP kinase I in enteric neurons
and intestinal smooth muscle.
AB - Nitric oxide/cGMP/cGMP kinase I (cGKI) signaling causes relaxation of intestinal
smooth muscle. In the gastrointestinal tract substrates of cGKI have not been
identified yet. In the present study a protein interacting with cGKIbeta has been
isolated from a rat intestinal cDNA library using the yeast two-hybrid system.
The protein was identified as cysteine-rich protein 2 (CRP2), recently cloned
from rat brain (Okano, I., Yamamoto, T., Kaji, A., Kimura, T., Mizuno, K., and
Nakamura, T. (1993) FEBS Lett. 333, 51-55). Recombinant CRP2 is specifically
phosphorylated by cGKs but not by cAMP kinase in vitro. Co-transfection of CRP2
and cGKIbeta into COS cells confirmed the phosphorylation of CRP2 in vivo. Cyclic
GMP kinase I phosphorylated CRP2 at Ser-104, because the mutation to Ala
completely prevented the in vivo phosphorylation. Immunohistochemical analysis
using confocal laser scan microscopy showed a co-localization of CRP2 and cGKI in
the inner part of the circular muscle layer, in the muscularis mucosae, and in
specific neurons of the myenteric and submucosal plexus. The co-localization
together with the specific phosphorylation of CRP2 by cGKI in vitro and in vivo
suggests that CRP2 is a novel substrate of cGKI in neurons and smooth muscle of
the small intestine.
PMID- 10681530
TI - The human AC133 hematopoietic stem cell antigen is also expressed in epithelial
cells and targeted to plasma membrane protrusions.
AB - The human AC133 antigen and mouse prominin are structurally related plasma
membrane proteins. However, their tissue distribution is distinct, with the AC133
antigen being found on hematopoietic stem and progenitor cells and prominin on
various epithelial cells. To determine whether the human AC133 antigen and mouse
prominin are orthologues or distinct members of a protein family, we examined the
human epithelial cell line Caco-2 for the possible expression of the AC133
antigen. By both immunofluorescence and immunoprecipitation, the AC133 antigen
was found to be expressed on the surface of Caco-2 cells. Interestingly,
immunoreactivity for the AC133 antigen, but not its mRNA level, was down
regulated upon differentiation of Caco-2 cells. The AC133 antigen was
specifically located at the apical rather than basolateral plasma membrane. An
apical localization of the AC133 antigen was also observed in various human
embryonic epithelia including the neural tube, gut, and kidney. Electron
microscopy revealed that, within the apical plasma membrane of Caco-2 cells, the
AC133 antigen was confined to microvilli and absent from the planar,
intermicrovillar regions. This specific subcellular localization did not depend
on an epithelial phenotype, because the AC133 antigen on hematopoietic stem
cells, as well as that ectopically expressed in fibroblasts, was selectively
found in plasma membrane protrusions. Hence, the human AC133 antigen shows the
features characteristic of mouse prominin in epithelial and transfected non
epithelial cells, i.e. a selective association with apical microvilli and plasma
membrane protrusions, respectively. Conversely, flow cytometry of murine CD34(+)
bone marrow progenitors revealed the cell surface expression of prominin. Taken
together, the data strongly suggest that the AC133 antigen is the human
orthologue of prominin.
PMID- 10681531
TI - X-ray structure of beta-carbonic anhydrase from the red alga, Porphyridium
purpureum, reveals a novel catalytic site for CO(2) hydration.
AB - The carbonic anhydrases (CAs) fall into three evolutionarily distinct families
designated alpha-, beta-, and gamma-CAs based on their primary structure. beta
CAs are present in higher plants, algae, and prokaryotes, and are involved in
inorganic carbon utilization. Here, we describe the novel x-ray structure of beta
CA from the red alga, Porphyridium purpureum, at 2.2-A resolution using intrinsic
zinc multiwavelength anomalous diffraction phasing. The CA monomer is composed of
two internally repeating structures, being folded as a pair of fundamentally
equivalent motifs of an alpha/beta domain and three projecting alpha-helices. The
motif is obviously distinct from that of either alpha- or gamma-CAs. This
homodimeric CA appears like a tetramer with a pseudo 222 symmetry. The active
site zinc is coordinated by a Cys-Asp-His-Cys tetrad that is strictly conserved
among the beta-CAs. No water molecule is found in a zinc-liganding radius,
indicating that the zinc-hydroxide mechanism in alpha-CAs, and possibly in gamma
CAs, is not directly applicable to the case in beta-CAs. Zinc coordination
environments of the CAs provide an interesting example of the convergent
evolution of distinct catalytic sites required for the same CO(2) hydration
reaction.
PMID- 10681532
TI - Cys-93-betabeta-succinimidophenyl polyethylene glycol 2000 hemoglobin A.
Intramolecular cross-bridging of hemoglobin outside the central cavity.
AB - Bis(maleidophenyl)-PEG2000 (Bis-Mal-PEG2000), a new bifunctional protein cross
linker targeted to sulfhydryl groups, introduces intra-tetrameric cross-links
into oxy-HbA in nearly quantitative yields. Structural as well as
crystallographic analyses of the cross-linked species, Bis-Mal-PEG2000 HbA,
identified Cys-93(beta) as the site of intramolecular cross-linking. The cross
bridging had only a limited influence on the O(2) affinity and cooperativity of
HbA in 50 mM BisTris acetate, pH 7.4. However, the Bohr effect was reduced by
approximately 60%. Bis-Mal-PEG2000 HbA retained sensitivity to the presence of
allosteric effectors 2, 3-diphosphoglycerate, IHP, and chloride, albeit to a
lesser degree compared with HbA. Crystallographic analysis revealed the overall
structure of deoxy-Bis-Mal-PEG2000 HbA to be similar to deoxy-HbA but for the
loss of the salt bridge between Asp-94(beta) and His-146(beta). The large
influence of the cross-bridging on the alkaline Bohr effect of HbA is consistent
with the loss of this salt bridge. Unlike the "central cavity cross-bridges"
described previously, the cross-link introduced by Bis-Mal-PEG2000 into HbA is an
"outside the central cavity cross-bridge." In view of its oxy-conformational
specificity and limited influence on O(2) affinity, this new cross-linking
strategy holds promise for the stabilization of new designer low O(2) affinity
Hbs generated by recombinant DNA technology for applications as Hb based
therapeutics.
PMID- 10681533
TI - Phosphorylation of microtubule-associated protein tau is regulated by protein
phosphatase 2A in mammalian brain. Implications for neurofibrillary degeneration
in Alzheimer's disease.
AB - Hyperphosphorylated tau, which is the major protein of the neurofibrillary
tangles in Alzheimer's disease brain, is most probably the result of an imbalance
of tau kinase and phosphatase activities in the affected neurons. By using
metabolically competent rat brain slices as a model, we found that selective
inhibition of protein phosphatase 2A by okadaic acid induced an Alzheimer-like
hyperphosphorylation and accumulation of tau. The hyperphosphorylated tau had a
reduced ability to bind to microtubules and to promote microtubule assembly in
vitro. Immunocytochemical staining revealed hyperphosphorylated tau accumulation
in pyramidal neurons in cornu ammonis and in neocortical neurons. The topography
of these changes recalls the distribution of neurofibrillary tangles in
Alzheimer's disease brain. Selective inhibition of protein phosphatase 2B with
cyclosporin A did not have any significant effect on tau phosphorylation,
accumulation, or function. These studies suggest that protein phosphatase 2A
participates in regulation of tau phosphorylation, processing, and function in
vivo. A down-regulation of protein phosphatase 2A activity can lead to Alzheimer
like abnormal hyperphosphorylation of tau.
PMID- 10681534
TI - Chymase as a proangiogenic factor. A possible involvement of chymase-angiotensin
dependent pathway in the hamster sponge angiogenesis model.
AB - We investigated the profound involvement of chymase, an alternative angiotensin
II-generating enzyme, in angiogenesis using a hamster sponge implant model. In
vivo transfection of human pro-chymase cDNA or a direct injection of purified
chymase into the sponges implanted resulted in marked increment of hemoglobin
contents in the sponge granuloma tissues, demonstrating that chymase has an
ability to elicit angiogenesis and is a potent angiogenic factor. Daily injection
of basic fibroblast growth factor into the sponges implanted also induced
angiogenesis, which was suppressed by the treatment with chymostatin, an
inhibitor of chymase, or TCV-116, an antagonist of angiotensin II (Ang II) type 1
receptor. Expression of chymase mRNA and production of Ang II in the granuloma
tissues were enhanced by the stimulation with basic fibroblast growth factor.
Chymase activity in the sponge granulomas increased in parallel with the rise in
hemoglobin contents, and mast cells observed in the granuloma tissues were
positively stained with anti-chymase antibody. Exogenous administration not only
of Ang II but of angiotensin I (Ang I) directly into the sponges could enhance
angiogenesis. Chymostatin inhibited the angiogenesis induced by Ang I but not Ang
II, suggesting the presence of a chymase-like Ang II-generating activity in the
sponge granulomas. Our results may suggest a potential ability of chymase to
promote angiogenesis through the local chymase-dependent and angiotensin
converting enzyme-dependent Ang II generating system in pathophysiological
angiogenesis.
PMID- 10681535
TI - Increased D-type cyclin expression together with decreased cdc2 activity confers
megakaryocytic differentiation of a human thrombopoietin-dependent hematopoietic
cell line.
AB - At the late phase of megakaryocytopoiesis, megakaryocytes undergo endomitosis,
which is characterized by DNA replication without cell division. Although a
number of cell cycle regulatory molecules have been identified, the precise roles
of these molecules in megakaryocytic endomitosis are largely unknown. In a human
interleukin-3-dependent cell line transfected with the thrombopoietin (TPO)
receptor c-mpl (F-36P-mpl), either treatment with TPO or the overexpression of
activated ras (Ha-Ras(G12V)) induced megakaryocytic maturation with polyploid
formation. We found that TPO stimulation or Ha-Ras(G12V) expression led to up
regulation of cyclin D1, cyclin D2, and cyclin D3 expression. In addition,
expression levels of cyclin A and cyclin B were reduced during the total course
of both TPO- and Ha-Ras(G12V)-induced megakaryocytic differentiation, thereby
leading to decreased cdc2 kinase activity. Neither the induced expression of
cyclin D1, cyclin D2, or cyclin D3 nor the expression of a dominant negative form
of cdc2 alone could induce megakaryocytic differentiation of F-36P-mpl cells. In
contrast, overexpression of dominant negative cdc2 together with cyclin D1,
cyclin D2, or cyclin D3 facilitated megakaryocytic differentiation in the absence
of TPO. These results suggest that both D-type cyclin expression and decreased
cdc2 kinase activity may participate in megakaryocytic differentiation.
PMID- 10681536
TI - Functional expression of the human hZIP2 zinc transporter.
AB - Zinc is an essential nutrient for humans, yet we know little about how this metal
ion is taken up by mammalian cells. In this report, we describe the
characterization of hZip2, a human zinc transporter identified by its similarity
to zinc transporters recently characterized in fungi and plants. hZip2 is a
member of the ZIP family of eukaryotic metal ion transporters that includes two
other human genes, hZIP1 and hZIP3, and genes in mice and rats. To test whether
hZip2 is a zinc transporter, we examined (65)Zn uptake activity in transfected
K562 erythroleukemia cells expressing hZip2 from the CMV promoter. hZip2
expressing cells accumulated more zinc than control cells because of an increased
initial zinc uptake rate. This activity was time-, temperature-, and
concentration-dependent and saturable with an apparent K(m) of 3 microM. hZip2
zinc uptake activity was inhibited by several other transition metals, suggesting
that this protein may transport other substrates as well. hZip2 activity was not
energy-dependent, nor did it require K(+) or Na(+) gradients. Zinc uptake by
hZip2 was stimulated by HCO(3)(-) treatment, suggesting a Zn(2+)-HCO(3)(-)
cotransport mechanism. Finally, hZip2 was exclusively localized in the plasma
membrane. These results indicate that hZip2 is a zinc transporter, and its
identification provides one of the first molecular tools to study zinc uptake in
mammalian cells.
PMID- 10681537
TI - Recognition of misfolding proteins by PA700, the regulatory subcomplex of the 26
S proteasome.
AB - The 26 S proteasome is a large protease complex that catalyzes the degradation of
both native and misfolded proteins. These proteins are known to interact with
PA700, the regulatory subcomplex of the 26 S proteasome, via a covalently
attached polyubiquitin chain. Here we provide evidence for an additional
ubiquitin-independent mode of substrate recognition by PA700. PA700 prevents the
aggregation of three incompletely folded, nonubiquitinated substrates: the DeltaF
508 mutant form of cystic fibrosis transmembrane regulator, nucleotide binding
domain 1, insulin B chain, and citrate synthase. This function does not require
ATP hydrolysis. The stoichiometry required for this function, the effect of PA700
on the lag phase of aggregation, and the temporal specificity of PA700 in this
process all indicate that PA700 interacts with a subpopulation of non-native
conformations that is either particularly aggregation-prone or nucleates
misassociation reactions. The inhibition of off-pathway self-association
reactions is also reflected in the ability of PA700 to promote refolding of
citrate synthase. These results provide evidence that, in addition to binding
polyubiquitin chains, PA700 contains a site(s) that recognizes and interacts with
misfolded or partially denatured polypeptides. This feature supplies an
additional level of substrate specificity to the 26 S proteasome and a means by
which substrates are maintained in a soluble state until refolding or degradation
is complete.
PMID- 10681538
TI - The yeast STM1 gene encodes a purine motif triple helical DNA-binding protein.
AB - The formation of triple helical DNA has been evoked in several cellular processes
including transcription, replication, and recombination. Using conventional and
affinity chromatography, we purified from Saccharomyces cerevisiae whole-cell
extract a 35-kDa protein that avidly and specifically bound a purine motif
triplex (with a K(d) of 61 pM) but not a pyrimidine motif triplex or duplex DNA.
Peptide microsequencing identified this protein as the product of the STM1 gene.
Confirmation that Stm1p is a purine motif triplex-binding protein was obtained by
electrophoretic mobility shift assays using either bacterially expressed,
recombinant Stm1p or whole-cell extracts from stm1Delta yeast. Stm1p has
previously been identified as G4p2, a G-quartet nucleic acid-binding protein.
This suggests that some proteins actually recognize features shared by G4 DNA and
purine motif triplexes, e.g. Hoogsteen hydrogen-bonded guanines. Genetically, the
STM1 gene has been identified as a multicopy suppressor of mutations in several
genes involved in mitosis (e.g. TOM1, MPT5, and POP2). A possible role for
multiplex DNA and its binding proteins in mitosis is discussed.
PMID- 10681539
TI - Molecular characterization of the non-biotin-containing subunit of 3
methylcrotonyl-CoA carboxylase.
AB - The biotin enzyme, 3-methylcrotonyl-CoA carboxylase (MCCase) (3-methylcrotonyl
CoA:carbon-dioxide ligase (ADP-forming), EC 6.4.1. 4), catalyzes a pivotal
reaction required for both leucine catabolism and isoprenoid metabolism. MCCase
is a heteromeric enzyme composed of biotin-containing (MCC-A) and non-biotin
containing (MCC-B) subunits. Although the sequence of the MCC-A subunit was
previously determined, the primary structure of the MCC-B subunit is unknown.
Based upon sequences of biotin enzymes that use substrates structurally related
to 3-methylcrotonyl-CoA, we isolated the MCC-B cDNA and gene of Arabidopsis.
Antibodies directed against the bacterially produced recombinant protein encoded
by the MCC-B cDNA react solely with the MCC-B subunit of the purified MCCase and
inhibit MCCase activity. The primary structure of the MCC-B subunit shows the
highest similarity to carboxyltransferase domains of biotin enzymes that use
methyl-branched thiol esters as substrate or products. The single copy MCC-B gene
of Arabidopsis is interrupted by nine introns. MCC-A and MCC-B mRNAs accumulate
in all cell types and organs, with the highest accumulation occurring in rapidly
growing and metabolically active tissues. In addition, these two mRNAs accumulate
coordinately in an approximately equal molar ratio, and they each account for
between 0.01 and 0.1 mol % of cellular mRNA. The sequence of the Arabidopsis MCC
B gene has enabled the identification of animal paralogous MCC-B cDNAs and genes,
which may have an impact on the molecular understanding of the lethal inherited
metabolic disorder methylcrotonylglyciuria.
PMID- 10681540
TI - Protein kinase C activation stimulates the phosphorylation and internalization of
the sst2A somatostatin receptor.
AB - The sst2A receptor is expressed in the endocrine, gastrointestinal, and neuronal
systems as well as in many hormone-sensitive tumors. This receptor is rapidly
internalized and phosphorylated in growth hormone-R2 pituitary cells following
somatostatin binding (Hipkin, R. W., Friedman, J., Clark, R. B., Eppler, C. M.,
and Schonbrunn, A. (1997) J. Biol. Chem. 272, 13869-13876). The protein kinase C
(PKC) activator, phorbol 12-myristate 13-acetate (PMA), also stimulates sst2A
phosphorylation. Here we examine the mechanisms and consequences of PMA and
agonist-induced sst2A phosphorylation. Like somatostatin, both PMA and bombesin
increased sst2A receptor phosphorylation within 2 min. The PKC inhibitor
GF109203X blocked PMA- and bombesin- stimulated sst2A phosphorylation, whereas
stimulation by the somatostatin analog SMS 201-995 was unaffected. Agonist and
PMA each stimulated phosphorylation in two receptor domains, the third
intracellular loop and the C-terminal tail. Functionally, PMA dramatically
increased the internalization of the sst2A receptor-ligand complex. This PMA
stimulation was blocked by GF109203X, whereas basal internalization was
unaffected. However, neither basal nor PMA-stimulated internalization was altered
by pertussis toxin, whereas both were blocked by hypertonic sucrose. Therefore
PKC activation and agonist binding stimulate sst2A phosphorylation by distinct
mechanisms, and PKC potentiates internalization of the sst2A receptor via
clathrin-coated pits. Thus, hormonal stimulation of PKC-coupled receptors may
provide a mechanism for regulating the inhibitory actions of somatostatin in
target tissue.
PMID- 10681541
TI - The Chk1 protein kinase and the Cdc25C regulatory pathways are targets of the
anticancer agent UCN-01.
AB - A checkpoint operating in the G(2) phase of the cell cycle prevents entry into
mitosis in the presence of DNA damage. UCN-01, a protein kinase inhibitor
currently undergoing clinical trials for cancer treatment, abrogates G(2)
checkpoint function and sensitizes p53-defective cancer cells to DNA-damaging
agents. In most species, the G(2) checkpoint prevents the Cdc25 phosphatase from
removing inhibitory phosphate groups from the mitosis-promoting kinase Cdc2. This
is accomplished by maintaining Cdc25 in a phosphorylated form that binds 14-3-3
proteins. The checkpoint kinases, Chk1 and Cds1, are proposed to regulate the
interactions between human Cdc25C and 14-3-3 proteins by phosphorylating Cdc25C
on serine 216. 14-3-3 proteins, in turn, function to keep Cdc25C out of the
nucleus. Here we report that UCN-01 caused loss of both serine 216
phosphorylation and 14-3-3 binding to Cdc25C in DNA-damaged cells. In addition,
UCN-01 potently inhibited the ability of Chk1 to phosphorylate Cdc25C in vitro.
In contrast, Cds1 was refractory to inhibition by UCN-01 in vitro, and Cds1 was
still phosphorylated in irradiated cells treated with UCN-01. Thus, neither Cds1
nor kinases upstream of Cds1, such as ataxia telangiectasia-mutated, are targets
of UCN-01 action in vivo. Taken together our results identify the Chk1 kinase and
the Cdc25C pathway as potential targets of G(2) checkpoint abrogation by UCN-01.
PMID- 10681542
TI - Identification by mutagenesis of arginines in the substrate binding site of the
porcine NADP-dependent isocitrate dehydrogenase.
AB - Pig heart mitochondrial NADP-dependent isocitrate dehydrogenase is the most
extensively studied among the mammalian isocitrate dehydrogenases. The crystal
structure of Escherichia coli isocitrate dehydrogenase and sequence alignment of
porcine with E. coli isocitrate dehydrogenase suggests that the porcine Arg(101),
Arg(110), Arg(120), and Arg(133) are candidates for roles in substrate binding.
The four arginines were separately mutated to glutamine using a polymerase chain
reaction method. Wild type and mutant enzymes were each expressed in E. coli,
isolated as maltose binding fusion proteins, then cleaved with thrombin, and
purified to yield homogeneous porcine isocitrate dehydrogenase. The R120Q mutant
has a specific activity, as well as K(m) values for isocitrate, Mn(2+), and
NADP(+) similar to wild type enzyme, indicating that Arg(120) is not needed for
function. The specific activities of R101Q, R110Q, and R133Q are 1.73, 1.30, and
19.7 micromols/min/mg, respectively, as compared with 39.6 units/mg for wild type
enzyme. The R110Q and R133Q enzymes exhibit K(m) values for isocitrate that are
increased more than 400- and 165-fold, respectively, as compared with wild type.
The K(m) values for Mn(2+), but not for NADP(+), are also elevated indicating
that binding of the metal-isocitrate complex is impaired in these mutants. It is
proposed that the positive charges of Arg(110) and Arg(133) normally strengthen
the binding of the negatively charged isocitrate by electrostatic attraction. The
R101Q mutant shows smaller, but significant increases in the K(m) values for
isocitrate and Mn(2+); however, the marked decrease in k(cat) suggests a role for
Arg(101) in catalysis. The V(max) of wild type enzyme depends on the ionized form
of an enzymic group of pK 5.5, and this pK(aes) is similar for the R101Q and
R120Q enzymes. In contrast, the pK(aes) for R110Q and R133Q enzymes increases to
6.4 and 7.4, respectively, indicating that the positive charges of Arg(110) and
Arg(133) normally lower the pK of the nearby catalytic base to facilitate its
ionization. These results may be understood in terms of the structure of the
porcine NADP-specific isocitrate dehydrogenase generated by the Insight II
Modeler Program, based on the x-ray coordinates of the E. coli enzyme.
PMID- 10681543
TI - Opposing role of mitogen-activated protein kinase subtypes, erk-1/2 and p38, in
the regulation of chondrogenesis of mesenchymes.
AB - The present studies were performed to determine subtype-specific roles of mitogen
activated protein kinase in chondrogenesis. Erk-1/2 activities, downstream of
protein kinase C, decreased as chondrogenesis proceeded, whereas p38 activities,
independent of protein kinase C, continuously increased during chondrogenesis.
Inhibition of Erk-1/2 with PD98059 enhanced chondrogenesis up to 1. 7-fold,
whereas inhibition of p38 with SB203580 reduced it to about 30% of the control
level. Inhibition of Erk-1/2 or p38 did not affect precartilage condensation.
However, cartilage nodule formation was significantly blocked by the inhibition
of p38, whereas Erk-1/2 inhibition did not affect it. Modulation of
chondrogenesis by the inhibition of Erk-1/2 and p38 was accompanied by altered
expression of adhesion molecules in an opposite way. Expression of N-cadherin was
reduced as chondrogenesis proceeded. Inhibition of p38 caused sustained
expression of N-cadherin, whereas Erk-1/2 inhibition accelerated the reduction of
N-cadherin expression. Expression of integrin alpha5beta1 and fibronectin were
found to transiently increase during chondrogenesis. Inhibition of p38 caused
continuous increase of expression of these molecules, whereas Erk-1/2 inhibition
accelerated the decrease of expression of these molecules at a later period of
chondrogenesis. Because temporal expression of these adhesion molecules regulates
chondrogenesis, the above results indicate that Erk-1/2 and p38 conversely
regulate chondrogenesis at post-precartilage condensation stages by modulating
expression of adhesion molecules.
PMID- 10681544
TI - The role of tryptophan residues in the 5-Hydroxytryptamine(3) receptor ligand
binding domain.
AB - Aromatic amino acids are important components of the ligand binding site in the
Cys loop family of ligand-gated ion channels. To examine the role of tryptophan
residues in the ligand binding domain of the 5-hydroxytryptamine(3) (5-HT(3))
receptor, we used site-directed mutagenesis to change each of the eight N
terminal tryptophan residues in the 5-HT(3A) receptor subunit to tyrosine or
serine. The mutants were expressed as homomeric 5-HT(3A) receptors in HEK293
cells and analyzed with radioligand binding, electrophysiology, and
immunocytochemistry. Mutation of Trp(90), Trp(183), and Trp(195) to tyrosine
resulted in functional receptors, although with increased EC(50) values (2-92
fold) to 5-HT(3) receptor agonists. Changing these residues to serine either
ablated function (Trp(90) and Trp(183)) or resulted in a further increase in
EC(50) (Trp(195)). Mutation of residue Trp(60) had no effect on ligand binding or
receptor function, whereas mutation of Trp(95), Trp(102), Trp(121), and Trp(214)
ablated ligand binding and receptor function, and all but one of the receptors
containing these mutations were not expressed at the plasma membrane. We propose
that Trp(90), Trp(183), and Trp(195) are intimately involved in ligand binding,
whereas Trp(95), Trp(102), Trp(121), and Trp(214) have a critical role in
receptor structure or assembly.
PMID- 10681545
TI - beta-Amyloid(1-42) binds to alpha7 nicotinic acetylcholine receptor with high
affinity. Implications for Alzheimer's disease pathology.
AB - Alzheimer's disease pathology is characterized by the presence of neuritic
plaques and the loss of cholinergic neurons in the brain. The underlying
mechanisms leading to these events are unclear, but the 42-amino acid beta
amyloid peptide (Abeta(1-42)) is involved. Immunohistochemical studies on human
sporadic Alzheimer's disease brains demonstrate that Abeta(1-42) and a neuronal
pentameric cation channel, the alpha7 nicotinic acetylcholine receptor
(alpha7nAChR), are both present in neuritic plaques and co-localize in individual
cortical neurons. Using human brain tissues and cells that overexpress either
alpha7nAChR or amyloid precursor protein as the starting material, Abeta(1-42)
and alpha7nAChR can be co-immunoprecipitated by the respective specific
antibodies, suggesting that they are tightly associated. The formation of the
alpha7nAChR.Abeta(1-42) complex can be efficiently suppressed by Abeta(12-28),
implying that this Abeta sequence region contains the binding epitope. Receptor
binding experiments show that Abeta(1-42) and alpha7nAChR bind with high
affinity, and this interaction can be inhibited by alpha7nAChR ligands. Human
neuroblastoma cells overexpressing alpha7nAChR are readily killed by Abeta(1-42),
whereas alpha7nAChR agonists such as nicotine and epibatidine offered protection.
Because Abeta(1-42) inhibits alpha7nAChR-dependent calcium activation and
acetylcholine release, two processes critically involved in memory and cognitive
functions, and the distribution of alpha7nAChR correlates with neuritic plaques
in Alzheimer's disease brains, we propose that interaction of the alpha7nAChR and
Abeta(1-42) is a pivotal mechanism involved in the pathophysiology of Alzheimer's
disease.
PMID- 10681546
TI - Phenylethylthiazolylthiourea (PETT) non-nucleoside inhibitors of HIV-1 and HIV-2
reverse transcriptases. Structural and biochemical analyses.
AB - Most non-nucleoside reverse transcriptase (RT) inhibitors are specific for HIV-1
RT and demonstrate minimal inhibition of HIV-2 RT. However, we report that
members of the phenylethylthiazolylthiourea (PETT) series of non-nucleoside
reverse transcriptase inhibitors showing high potency against HIV-1 RT have
varying abilities to inhibit HIV-2 RT. Thus, PETT-1 inhibits HIV-1 RT with an
IC(50) of 6 nM but shows only weak inhibition of HIV-2 RT, whereas PETT-2 retains
similar potency against HIV-1 RT (IC(50) of 5 nM) and also inhibits HIV-2 RT
(IC(50) of 2.2 microM). X-ray crystallographic structure determinations of PETT-1
and PETT-2 in complexes with HIV-1 RT reveal the compounds bind in an overall
similar conformation albeit with some differences in their interactions with the
protein. To investigate whether PETT-2 could be acting at a different site on HIV
2 RT (e.g. the dNTP or template primer binding site), we compared modes of
inhibition for PETT-2 against HIV-1 and HIV-2 RT. PETT-2 was a noncompetitive
inhibitor with respect to the dGTP substrate for both HIV-1 and HIV-2 RTs. PETT-2
was also a noncompetitive inhibitor with respect to a poly(rC).(dG) template
primer for HIV-2 RT. These results are consistent with PETT-2 binding in
corresponding pockets in both HIV-1 and HIV-2 RT with amino acid sequence
differences in HIV-2 RT affecting the binding of PETT-2 compared with PETT-1.
PMID- 10681547
TI - Identification and characterization of a novel hepatic canalicular ATP
diphosphohydrolase.
AB - We have identified and characterized a novel ATP diphosphohydrolase (ATPDase)
with features of E-type ATPases from porcine liver. Immunoblotting with a
specific monoclonal antibody to this ectoenzyme revealed high expression in liver
with lesser amounts in kidney and duodenum. This ATPDase was localized by
immunohistochemistry to the bile canalicular domain of hepatocytes and to the
luminal side of the renal ductular epithelium. In contrast, ATPDase/cd39 was
detected in vascular endothelium and smooth muscle in these organs. We purified
the putative ATPDase from liver by immunoaffinity techniques and obtained a
heavily glycosylated protein with a molecular mass estimated at 75 kDa. This
enzyme hydrolyzed all tri- and diphosphonucleosides but not AMP or diadenosine
polyphosphates. There was an absolute requirement for divalent cations (Ca(2+) >
Mg(2+)). Biochemical activity was unaffected by sodium azide or other inhibitors
of ATPases. Kinetic parameters derived from purified preparations of hepatic
ATPDase indicated V(max) of 8.5 units/mg of protein with apparent K(m) of 100
microM for both ATP or ADP as substrates. NH(2)-terminal amino acid sequencing
revealed near 50% identity with rat liver lysosomal (Ca(2+)-Mg(2+))-ATPase. The
different biochemical properties and localization of the hepatic ATPDase suggest
pathophysiological functions that are distinct from the vascular ATPDase/cd39.
PMID- 10681548
TI - Identification of a gp130 cytokine receptor critical site involved in oncostatin
M response.
AB - Gp130 cytokine receptor is involved in the formation of multimeric functional
receptors for interleukin-6 (IL-6), IL-11, leukemia inhibitory factor (LIF),
oncostatin M (OSM), ciliary neurotrophic factor, and cardiotrophin-1. Cloning of
the epitope recognized by an OSM-neutralizing anti-gp130 monoclonal antibody
identified a portion of gp130 receptor localized in the EF loop of the cytokine
binding domain. Site-directed mutagenesis of the corresponding region was carried
out by alanine substitution of residues 186-198. To generate type 1 or type 2 OSM
receptors, gp130 mutants were expressed together with either LIF receptor beta or
OSM receptor beta. When positions Val-189/Tyr-190 and Phe-191/Val-192 were
alanine-substituted, Scatchard analyses indicated a complete abrogation of OSM
binding to both type receptors. Interestingly, binding of LIF to type 1 receptor
was not affected, corroborating the notion that in this case gp130 mostly behaves
as a converter protein rather than a binding receptor. The present study
demonstrates that positions 189-192 of gp130 cytokine binding domain are
essential for OSM binding to both gp130/LIF receptor beta and gp130/OSM receptor
beta heterocomplexes.
PMID- 10681549
TI - TspO of rhodobacter sphaeroides. A structural and functional model for the
mammalian peripheral benzodiazepine receptor.
AB - The function and specific structural aspects of the tryptophan-rich sensory
protein (TspO) of Rhodobacter sphaeroides 2.4.1 were studied using site-directed
mutagenesis involving some 17 different amino acids. The choice of these amino
acids changes was dictated from an analysis of the TspO family of proteins
derived from the data bases. These studies demonstrated the importance of several
highly conserved tryptophan residues in the sensory transduction pathway
involving TspO through the proposed binding of an intermediate(s) in the
tetrapyrrole biosynthesis pathway. These studies also revealed that the
substitution of one or several of the amino acid residues dramatically affected,
either directly or indirectly, the levels of TspO in the membranes of R.
sphaeroides. Mounting evidence is presented suggesting that TspO normally forms a
dimer within the bacterial outer membrane, and the dimer form of TspO may be the
active form for TspO function. Because our earlier studies provided us with a
functional framework within which to view these amino acid substitutions, we are
able to suggest a preliminary model for TspO structure-function. Not only do
these studies tell us more about TspO, but they also shed light on the TspO
homologue, the drug-binding component of the mitochondrial peripheral
benzodiazepine receptor. Mounting evidence draws numerous parallelism between
these proteins and supports the significance of using TspO as a model for the
structure and function of the mitochondrial protein.
PMID- 10681550
TI - Highly hydrophilic proteins in prokaryotes and eukaryotes are common during
conditions of water deficit.
AB - The late embryogenesis abundant (LEA) proteins are plant proteins that are
synthesized at the onset of desiccation in maturing seeds and in vegetative
organs exposed to water deficit. Here, we show that most LEA proteins are
comprised in a more widespread group, which we call "hydrophilins." The defining
characteristics of hydrophilins are high glycine content (>6%) and a high
hydrophilicity index (>1.0). By data base searching, we show that this criterion
selectively differentiates most known LEA proteins as well as additional proteins
from different taxons. We found that within the genomes of Escherichia coli and
Saccharomyces cerevisiae, only 5 and 12 proteins, respectively, meet our
criterion. Despite their deceivingly loose definition, hydrophilins usually
represent <0.2% of the proteins of a genome. Additionally, we demonstrate that
the criterion that defines hydrophilins seems to be an excellent predictor of
responsiveness to hyperosmosis since most of the genes encoding these proteins in
E. coli and S. cerevisiae are induced by osmotic stress. Evidence for the
participation of one of the E. coli hydrophilins in the adaptive response to
hyperosmotic conditions is presented. Apparently, hydrophilins represent
analogous adaptations to a common problem in such diverse taxons as prokaryotes
and eukaryotes.
PMID- 10681551
TI - The sequence of a gastropod hemocyanin (HtH1 from Haliotis tuberculata).
AB - The eight functional units (FUs), a-h, of the hemocyanin isoform HtH1 from
Haliotis tuberculata (Prosobranchia, Archaeogastropoda) have been sequenced via
cDNA, which provides the first complete primary structure of a gastropod
hemocyanin subunit. With 3404 amino acids (392 kDa) it is the largest polypeptide
sequence ever obtained for a respiratory protein. The cDNA comprises 10,758 base
pairs and includes the coding regions for a short signal peptide, the eight
different functional units, a 3'-untranslated region of 478 base pairs, and a
poly(A) tail. The predicted protein contains 13 potential sites for N-linked
carbohydrates (one for HtH1-a, none for HtH1-c, and two each for the other six
functional units). Multiple sequence alignments show that the fragment HtH1
abcdefg is structurally equivalent to the seven-FU subunit from Octopus
hemocyanin, which is fundamental to our understanding of the quaternary
structures of both hemocyanins. Using the fossil record of the gastropod
cephalopod split to calibrate a molecular clock, the origin of the molluscan
hemocyanin from a single-FU protein was calculated as 753 +/- 68 million years
ago. This fits recent paleontological evidence for the existence of rather large
mollusc-like species in the late Precambrian.
PMID- 10681552
TI - A network of conserved intramolecular contacts defines the off-state of the
transmembrane switch mechanism in a seven-transmembrane receptor.
AB - Activation of the rhodopsin-like 7-transmembrane (7-TM) receptors requires
switching interhelical constraints that stabilize the inactive state to a new set
of contacts in the activated state, which binds the cognate G-protein. The free
energy to drive this is provided by agonist binding, which has higher affinity to
the active than to the inactive conformation. We have sought specific
interhelical constraint contacts, using the M(1) muscarinic acetylcholine
receptor as a model. Histidine substitutions of particular groups of amino acids,
in transmembrane domains 3, 6, and 7, created high-affinity Zn(2+) binding sites,
demonstrating the close proximity of their side chains in the inactive state.
Alanine point substitutions have shown the effect of weakening the individual
intramolecular contacts. In each case, the acetylcholine affinity was increased,
implying promotion of the activated state. These amino acids are highly conserved
throughout the 7-TM receptor superfamily. We propose that they form an important
part of a network of conserved interhelical contacts that defines the off-state
of a general transmembrane switch mechanism.
PMID- 10681553
TI - Four conserved cytoplasmic sequence motifs are important for transport function
of the Leishmania inositol/H(+) symporter.
AB - The protozoan Leishmania donovani has a myo-inositol/proton symporter (MIT) that
is a member of a large sugar transporter superfamily. Active transport by MIT is
driven by the proton electrochemical gradient across the parasite membrane, and
MIT is a prototype for understanding the function of an active transporter in
lower eukaryotes. MIT contains two duplicated 6- or 7-amino acid motifs within
cytoplasmic loops, which are highly conserved among 50 members of the sugar
transporter superfamily and are designated A(1), A(2) ((V)(D/E)(R/K)PhiGR(R/K)),
and B(1) (PESPRPhiL), B(2) (VPETKG). In particular, the three acidic residues
within these motifs, Glu(187)(B(1)), Asp(300)(A(2)), and Glu(429)(B(2)) in MIT,
are highly conserved with 96, 78, and 96% amino acid identity within the analyzed
members of this transporter superfamily ranging from bacteria, archaea, and fungi
to plants and the animal kingdom. We have used site-directed mutagenesis in
combination with functional expression of transporter mutants in Xenopus oocytes
and overexpression in Leishmania transfectants to investigate the significance of
these three acidic residues in the B(1), A(2), and B(2) motifs. Alteration to the
uncharged amides greatly reduced MIT transport function to 23% (E187Q), 1.4%
(D300N), and 3% (E429Q) of wild-type activity, respectively, by affecting V(max)
but not substrate affinity. Conservative mutations that retained the charge
revealed a less pronounced effect on inositol transport with 39% (E187D), 16%
(D300E) and 20% (E429D) remaining transport activity. Immunofluorescence
microscopy of oocyte cryosections confirmed that MIT mutants were expressed on
the oocyte surface in similar quantity to MIT wild type. The proton uncouplers
carbonylcyanide-4-(trifluoromethoxy) phenylhydrazone and dinitrophenol inhibited
inositol transport by 50-70% in the wild type as well as in E187Q, D300N, and
E429Q, despite their reduced transport activities, suggesting that transport in
these mutants is still proton-coupled. Furthermore, temperature-dependent uptake
studies showed an increased Arrhenius activation energy for the B(1)-E187Q and
the B(2)-E429Q mutants, which supports the idea of an impaired transporter cycle
in these mutants. We conclude that the conserved acidic residues Glu(187),
Asp(300), and Glu(429) are critical for transport function of MIT.
PMID- 10681554
TI - Lipoprotein lipase (LPL) strongly links native and oxidized low density
lipoprotein particles to decorin-coated collagen. Roles for both dimeric and
monomeric forms of LPL.
AB - Low density lipoprotein (LDL) and oxidized LDL are associated with collagen in
the arterial intima, where the collagen is coated by the small proteoglycan
decorin. When incubated in physiological ionic conditions, decorin-coated
collagen bound only small amounts of native and oxidized LDL, the interaction
being weak. When decorin-coated collagen was first allowed to bind lipoprotein
lipase (LPL), binding of native and oxidized LDL increased dramatically (23- and
7-fold, respectively). This increase depended on strong interactions between LPL
that was bound to the glycosaminoglycan chains of the collagen-bound decorin and
native and oxidized LDL (kDa 12 and 5.9 nM, respectively). To distinguish between
binding to monomeric (inactive) and dimeric (catalytically active) forms of LPL,
affinity chromatography on heparin columns was conducted, which showed that
native LDL bound to the monomeric LPL, whereas oxidized LDL, irrespective of the
type of modification (Cu(2+), 2, 2'-azobis(2-amidinopropane)hydrochloride,
hypochlorite, or soybean 15-lipoxygenase), bound preferably to dimeric LPL.
However, catalytic activity of LPL was not required for binding to oxidized LDL.
Finally, immunohistochemistry of atherosclerotic lesions of human coronary
arteries revealed specific areas in which LDL, LPL, decorin, and collagen type I
were present. The results suggest that LPL can retain LDL in atherosclerotic
lesions along decorin-coated collagen fibers.
PMID- 10681555
TI - A role for a helical connector between two receptor binding sites of a long-chain
peptide hormone.
AB - The conformational freedom of single-chain peptide hormones, such as the 41-amino
acid hormone corticotropin releasing factor (CRF), is a major obstacle to the
determination of their biologically relevant conformation, and thus hampers
insights into the mechanism of ligand-receptor interaction. Since N- and C
terminal truncations of CRF lead to loss of biological activity, it has been
thought that almost the entire peptide is essential for receptor activation. Here
we show the existence of two segregated receptor binding sites at the N and C
termini of CRF, connection of which is essential for receptor binding and
activation. Connection of the two binding sites by highly flexible epsilon
aminocaproic acid residues resulted in CRF analogues that remained full, although
weak agonists (EC(50): 100-300 nM) independent of linker length. Connection of
the two sites by an appropriate helical peptide led to a very potent analogue,
which adopted, in contrast to CRF itself, a stable, monomer conformation in
aqueous solution. Analogues in which the two sites were connected by helical
linkers of different lengths were potent agonists; their significantly different
biopotencies (EC(50): 0.6-50 nM), however, suggest the relative orientation
between the two binding sites rather than the maintenance of a distinct distance
between them to be essential for a high potency.
PMID- 10681556
TI - Characterization and subcellular localization of murine and human magnesium
dependent neutral sphingomyelinase.
AB - Sphingomyelinases (SMases) catalyze the hydrolysis of sphingomyelin, an essential
lipid constituent of the plasma membrane, lysosomal membranes, endoplasmic
reticulum, and the Golgi membrane stacks of mammalian cells. In this study, we
report the biochemical and functional characterization and subcellular
localization of magnesium-dependent nSMase1 from overexpressing human embryonic
kidney (HEK293) cells. Site-directed mutagenesis of conserved residues probably
involved in the enzymatic sphingomyelin cleavage as well as the removal of one or
both putative transmembrane domains lead to the complete loss of enzymatic
activity of human nSMase1 expressed in HEK293 cells. Polyclonal antibodies raised
against recombinant mammalian nSMase1 immunoprecipitated and inactivated the
enzyme in membrane extracts of overexpressing HEK293 cells and different murine
tissues. Cell fractionation combined with immunoprecipitation studies localized
the nSMase1 protein predominantly in the microsomal fraction. The enzyme
colocalized with marker proteins of the endoplasmic reticulum and the Golgi
apparatus in immunocytochemistry. Anti-nSMase1 antibodies did not affect the
nSMase activity in the plasma membrane fraction and membrane extracts from murine
brain. Our study leads to the conclusion that nSMase1 is one of at least two
mammalian neutral sphingomyelinases with different subcellular localization,
tissue specificity, and enzymatic properties.
PMID- 10681557
TI - Functional reconstitution of the Na(+)-driven polar flagellar motor component of
Vibrio alginolyticus.
AB - The bacterial flagellar motor is a molecular machine that couples the influx of
specific ions to the generation of the force necessary to drive rotation of the
flagellar filament. Four integral membrane proteins, PomA, PomB, MotX, and MotY,
have been suggested to be directly involved in torque generation of the Na(+)
driven polar flagellar motor of Vibrio alginolyticus. In the present study, we
report the isolation of the functional component of the torque-generating unit.
The purified protein complex appears to consist of PomA and PomB and contains
neither MotX nor MotY. The PomA/B protein, reconstituted into proteoliposomes,
catalyzed (22)Na(+) influx in response to a potassium diffusion potential. Sodium
uptake was abolished by the presence of Li(+) ions and phenamil, a sodium channel
blocker. This is the first demonstration of a purification and functional
reconstitution of the bacterial flagellar motor component involved in torque
generation. In addition, this study demonstrates that the Na(+)-driven motor
component, PomA and PomB, forms the Na(+)-conducting channel.
PMID- 10681558
TI - Distinct physiological functions of thiol peroxidase isoenzymes in Saccharomyces
cerevisiae.
AB - A new type of peroxidase ("thiol peroxidase"; TPx) having cysteine as the primary
site of catalysis has been discovered from prokaryotes to eukaryotes. In addition
to two yeast TPx isoforms (TSA I and TSA II/AHPC1) previously described, three
additional TPx homologues were identified by analysis of the open reading frame
data base for Saccharomyces cerevisiae. Three novel isoforms showed a distinct
thiol peroxidase activity supported by thioredoxin, and appeared to be
distinctively localized in cytoplasm, mitochondria, and nucleus. Each isoform was
named after its subcellular localization such as cytoplasmic TPx I (cTPx I or TSA
I), cTPx II, cTPx III (TSA II/AHPC1), mitochondrial TPx (mTPx), and nuclear TPx
(nTPx). Their transcriptional activities suggest that cTPx I and cTPx III are the
most predominant isoforms among the five type isoforms. Transcriptional
activities of TPx isoenzymes during yeast life span were quite different from
each other. Unlike other TPx null mutants, cTPx I null mutant was hypersensitive
to various oxidants except for 4-nitroquinoline N-oxide. The null mutant was more
resistant toward 4-nitroquinoline N-oxide and acidic culture than its wild type.
The severe growth retardation of cTPx II mutant resulted in accumulation of G(1)
phased cells. Based on kinetic properties of five isoforms, their subcellular
localizations, and distinct physiology of each null mutant, we discussed the
physiological functions of five types of TPx isoenzymes in yeast throughout the
full growth cycle.
PMID- 10681559
TI - p76(MDM2) inhibits the ability of p90(MDM2) to destabilize p53.
AB - The mdm2 oncogene encodes p90(MDM2), which binds to and inactivates the p53 tumor
suppressor protein. p90(MDM2) inhibits p53 by blocking the transcriptional
activation domain of p53 as well as by stimulating its degradation. Recently, we
showed that another product of the wild-type mdm2 gene, p76(MDM2), lacks the
first 49 amino acids of p90(MDM2) and cannot bind p53. Here, we report that, like
p90(MDM2), p76(MDM2) is expressed in both the nuclear and cytoplasmic
compartments. Overexpression of p76(MDM2) antagonizes the ability of p90(MDM2) to
stimulate the degradation of p53 and leads to an increase in the levels and
activity of p53. Seven murine tissues express an alternatively spliced mdm2 mRNA
that can encode p76(MDM2) but not p90(MDM2), as well as the normally spliced mdm2
mRNA that encodes both MDM2 proteins. All seven tissues express both MDM2
proteins. p90(MDM2) is much more abundant than p76(MDM2) in the testis, brain,
heart, and kidney. However, in those tissues known to undergo p53-mediated
apoptosis in response to gamma-irradiation, the thymus, spleen, and intestine,
the levels of the MDM2 proteins are roughly equivalent. Our results indicate that
the ratio of the two MDM2 proteins may regulate the response of tissues to DNA
damage.
PMID- 10681560
TI - Distinct roles for amino- and carboxyl-terminal sequences of SPRR1 protein in the
formation of cross-linked envelopes of conducting airway epithelial cells.
AB - The small proline-rich protein, SPRR1, is a marker gene whose expression in
conducting airway epithelium is elevated under a variety of conditions that
enhance squamous differentiation. The purpose of this study is to elucidate the
nature of the SPRR1 sequence involved in cross-linked envelope formation in a
tissue/cell type, such as conducting airway epithelium, that normally does not
express squamous function except after injury or maintenance in culture. For
this, a Flag-SPRR1 fusion protein expression system has been developed. Using the
liposome-mediated gene transfer technique on passage 1 culture of human
tracheobronchial epithelial (TBE) cells, the Flag-SPRR1 fusion protein can be
expressed and detected immunologically by both anti-Flag and anti-SPRR1
antibodies. The incorporation of Flag-SPRR1 fusion protein into cross-linked
envelopes can be demonstrated when transfected human passage 1 TBE cultures are
treated with phorbol 12-myristate 13-acetate and high calcium (1.5 mM). By
deletion and site-directed mutagenesis, two distinct roles of the amino- and
carboxyl-terminal sequences of SPRR1 have been demonstrated. First, we
demonstrated that the amino-terminal sequence of SPRR1 protein is required for
the incorporation of the fusion protein into cross-linked envelopes, whereas a
deletion on the carboxyl-terminal region or on the middle repetitive unit has no
effect. Interestingly, insertion of a 24-amino acid peptide of monkey MUC2
repetitive sequence in the amino-terminus of SPRR1 protein had a stimulatory
effect. Site-directed mutagenesis on the following amino acid residues, Lys(7),
Gln(88), and Lys(89), which were found previously to participate in the cross
linked envelope formation of keratinocytes, had no detrimental effect on the
incorporation. However, mutations on Gln clusters, such as Gln(4)-Gln(6) and
Gln(22)-Gln(25), had detrimental effects on the incorporation. These results
suggest an amino-terminal sequence-dependent and multiple cross-linked sites for
the incorporation of Flag-SPRR1 fusion protein into cross-linked envelopes of
cultured human TBE cells. Second, we demonstrated that the carboxyl terminus of
SPRR1 protein is required for a high level of Flag-fusion protein expression. A
deletion in the carboxyl region or a mutation on the last lysine residue of the
carboxyl end had a detrimental effect on the level of Flag-SPRR1 fusion protein
expressed in transfected cells. In contrast, there was only a slight decrease in
the level of expression if the amino-terminus was deleted. Interestingly, the
efficiency for fusion protein to incorporate into cross-linked envelopes was
elevated by the mutation at the carboxyl end. These results suggest distinct
roles, perhaps coordinately, for both amino- and carboxyl-terminal sequences in
the regulation of the life cycle of SPRR1 protein in cultured TBE cells.
PMID- 10681561
TI - Epiregulin, a novel member of the epidermal growth factor family, is an autocrine
growth factor in normal human keratinocytes.
AB - Epiregulin is a new member of the epidermal growth factor (EGF) family purified
from conditioned medium of NIH-3T3 clone T7. Some EGF family growth factors play
essential roles in human keratinocytes in an autocrine manner. We show here that
epiregulin is another autocrine growth factor for human keratinocytes. Epiregulin
stimulated human keratinocyte proliferation under both subconfluent and confluent
culture conditions in the absence of exogenous EGF family growth factors.
Immunoprecipitation of [(35)S]methionine-labeled conditioned medium revealed a 5
kDa band corresponding to epiregulin. Northern blot analysis detected a 4. 8
kilobase transcript of epiregulin, and the addition of epiregulin up-regulated
epiregulin mRNA synthesis. Furthermore, an anti-epiregulin blocking antibody
reduced DNA synthesis by 25%. Epiregulin up-regulated the mRNA levels of heparin
binding EGF-like growth factor (HB-EGF), amphiregulin, and TGF-alpha. In turn,
the addition of EGF, HB-EGF, amphiregulin, and TGF-alpha increased epiregulin
mRNA levels. These results demonstrate that epiregulin acts as an autocrine
growth factor in human epidermal keratinocytes and is part of auto- and cross
induction mechanisms involving HB-EGF, amphiregulin, and TGF-alpha. The mRNA
expression profile resulting from induction of differentiation with high calcium
and fetal calf serum revealed the differential expression of epiregulin, HB-EGF,
amphiregulin, and TGF-alpha in keratinocytes. This indicates that these four
growth factors have distinct, non-redundant biological functions.
PMID- 10681562
TI - A dominant-negative peroxisome proliferator-activated receptor gamma (PPARgamma)
mutant is a constitutive repressor and inhibits PPARgamma-mediated adipogenesis.
AB - The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma)
promotes adipocyte differentiation, exerts atherogenic and anti-inflammatory
effects in monocyte/macrophages, and is believed to mediate the insulin
sensitizing action of antidiabetic thiazolidinedione ligands. As no complete
PPARgamma antagonists have been described hitherto, we have constructed a
dominant-negative mutant receptor to inhibit wild-type PPARgamma action. Highly
conserved hydrophobic and charged residues (Leu(468) and Glu(471)) in helix 12 of
the ligand-binding domain were mutated to alanine. This compound PPARgamma mutant
retains ligand and DNA binding, but exhibits markedly reduced transactivation due
to impaired coactivator (cAMP-response element-binding protein-binding protein
and steroid receptor coactivator-1) recruitment. Unexpectedly, the mutant
receptor silences basal gene transcription, recruits corepressors (the silencing
mediator of retinoid and thyroid receptors and the nuclear corepressor) more
avidly than wild-type PPARgamma, and exhibits delayed ligand-dependent
corepressor release. It is a powerful dominant-negative inhibitor of
cotransfected wild-type receptor action. Furthermore, when expressed in primary
human preadipocytes using a recombinant adenovirus, this PPARgamma mutant blocks
thiazolidinedione-induced differentiation, providing direct evidence that
PPARgamma mediates adipogenesis. Our observations suggest that, as in other
mutant nuclear receptor contexts (acute promyelocytic leukemia, resistance to
thyroid hormone), dominant-negative inhibition by PPARgamma is linked to aberrant
corepressor interaction. Adenoviral expression of this mutant receptor is a
valuable means to antagonize PPARgamma signaling.
PMID- 10681563
TI - Glycoprotein IIb/IIIa antagonists induce apoptosis in rat cardiomyocytes by
caspase-3 activation.
AB - The platelet integrin glycoprotein (GP) IIb/IIIa, which mediates platelet
aggregation, has been the target for novel antiplatelet agents, the GPIIb/IIIa
antagonists. Several GPIIb/IIIa antagonists have been developed based on the
peptide RGDS present in adhesion proteins, including the principle ligand
fibrinogen. The apoptosis enzyme, procaspase-3, contains an RGD-recognition
sequence and is activated by RGDS. We examined the effects of RGDS and several
GPIIb/IIIa antagonists on cell death and procaspase-3 activation in rat neonatal
cardiomyocytes. These antagonists do not recognize rat integrins, yet RGDS,
orbofiban, and xemilofiban induced dose-dependent apoptosis and procaspase-3
activation in cardiomyocytes over 72 h, particularly under hypoxic conditions.
Scrambled peptide, the monoclonal antibody 7E3 or integrelin (a peptide
containing a KGD sequence), had little or no effect. Immunoprecipitation of
procaspase-3 followed by treatment with the compounds showed that procaspase-3
was activated directly by RGDS, orbofiban, xemilofiban, and by monoclonal 7E3
antibody, the latter demonstrating that compounds must enter cells to induce
apoptosis through caspase activation. Integrelin had no effect. Binding studies
with (3)H-SC52012B, a GPIIb/IIIa antagonist analogue of orbofiban, showed no
specific binding to cardiomyocytes, but the radioligand accumulated
intracellularly over 72 h. (3)H-SC52012B also bound directly to human recombinant
caspase-3 (K(d), 59 +/- 2 nm), and this was prevented by orbofiban, xemilofiban,
and the monoclonal 7E3 antibody but not by integrelin. Finally confocal
microscopy showed that RGDS co-localized with caspase-3 inside the cell. These
data show that RGDS and its mimetics induce cardiomyocyte apoptosis by direct
activation of procaspase-3.
PMID- 10681564
TI - The assembly factor Atp11p binds to the beta-subunit of the mitochondrial F(1)
ATPase.
AB - Atp11p is a protein of Saccharomyces cerevisiae required for the assembly of the
F(1) component of the mitochondrial F(1)F(0)-ATP synthase. This study presents
evidence that Atp11p binds selectively to the beta-subunit of F(1). Under
conditions in which avidin-Sepharose beads specifically adsorbed biotinylated
Atp11p from yeast mitochondrial extracts, the F(1) beta-subunit coprecipitated
with the tagged Atp11p protein. Binding interactions between Atp11p and the
entire beta-subunit of F(1) or fragments of the beta-subunit were also revealed
by a yeast two-hybrid screen: Atp11p bound to a region of the nucleotide-binding
domain of the beta-subunit located between Gly(114) and Leu(318). Certain
elements of this sequence that would be accessible to Atp11p in the free beta
subunit make contact with adjacent alpha-subunits in the assembled enzyme. This
observation suggests that the alpha-subunits may exchange for bound Atp11p during
the process of F(1) assembly.
PMID- 10681565
TI - Occludin modulates transepithelial migration of neutrophils.
AB - Neutrophils cross epithelial sheets to reach inflamed mucosal surfaces by
migrating along the paracellular route. To avoid breakdown of the epithelial
barrier, this process requires coordinated opening and closing of tight
junctions, the most apical intercellular junctions in epithelia. To determine the
function of epithelial tight junction proteins in this process, we analyzed
neutrophil migration across monolayers formed by stably transfected epithelial
cells expressing wild-type and mutant occludin, a membrane protein of tight
junctions with four transmembrane domains and both termini in the cytosol. We
found that expression of mutants with a modified N-terminal cytoplasmic domain up
regulated migration, whereas deletion of the C-terminal cytoplasmic domain did
not have an effect. The N-terminal cytosolic domain was also found to be
important for the linear arrangement of occludin within tight junctions but not
for the permeability barrier. Moreover, expression of mutant occludin bearing a
mutation in one of the two extracellular domains inhibited neutrophil migration.
The effects of transfected occludin mutants on neutrophil migration did not
correlate with their effects on selective paracellular permeability and
transepithelial electrical resistance. Hence, specific domains and functional
properties of occludin modulate transepithelial migration of neutrophils.
PMID- 10681566
TI - Discoidin domain receptor 1 is activated independently of beta(1) integrin.
AB - Various types of collagen have been identified as potential ligands for the two
mammalian discoidin domain receptor (DDR) tyrosine kinases, DDR1 and DDR2. It is
presently unclear whether collagen-induced DDR receptor activation, which occurs
with very slow kinetics, involves additional proteins with kinase activity or
membrane-anchored proteins serving as coreceptors. In particular, the role of the
collagen-binding integrins alpha(1)beta(1) or alpha(2)beta(1) in the DDR
activation process is undefined. Here, we provide three lines of evidence
suggesting that DDR1 signaling is distinct from integrin activation. First we
demonstrate that the enzymatic activity of DDR1 is essential for receptor
tyrosine phosphorylation. Collagen-induced DDR receptor autophosphorylation can
be blocked either by a dominant negative mutant or by a preparation of
recombinant extracellular domain. Second, we show DDR1 signals independent of the
epidermal growth factor (EGF) receptor. In cells that endogenously express both
DDR1 and the EGF receptor, stimulation with EGF does not induce DDR activation.
Third, we detected full DDR1 activation after collagen stimulation in cells that
have been treated with blocking antibodies for alpha(2)beta(1) integrin or in
cells with a targeted deletion of the beta(1) integrin gene. Finally, we show
that overexpression of dominant negative DDR1 in the myoblast cell line C2C12
blocks cellular differentiation and the formation of myofibers.
PMID- 10681567
TI - Structures, enzymatic properties, and expression of novel human and mouse
secretory phospholipase A(2)s.
AB - Mammalian secretory phospholipase A(2)s (sPLA(2)s) form a family of structurally
related enzymes that are involved in a variety of physiological and pathological
processes via the release of arachidonic acid from membrane phospholipids or the
binding to specific membrane receptors. Here, we report the cloning and
characterization of a novel sPLA(2) that is the sixth isoform of the sPLA(2)
family found in humans. The novel human mature sPLA(2) consists of 123 amino
acids (M(r) = 14,000) and is most similar to group IIA sPLA(2) (sPLA(2)-IIA) with
respect to the number and positions of cysteine residues as well as overall
identity (51%). Therefore, this novel sPLA(2) should be categorized into group II
and called group IIE (sPLA(2)-IIE) following the recently identified group IID
sPLA(2) (sPLA(2)-IID). The enzymatic properties of recombinant human sPLA(2)-IIE
were almost identical to those of sPLA(2)-IIA and IID in terms of Ca(2+)
requirement, optimal pH, substrate specificity, as well as high susceptibility to
the sPLA(2) inhibitor indoxam. Along with the biochemical properties of proteins,
genetic and evolutional similarities were also observed among these three types
of group II sPLA(2)s as to the chromosomal location of the human gene (1p36) and
the exon/intron organization. The expression of sPLA(2)-IIE transcripts in humans
was restricted to the brain, heart, lung, and placenta in contrast to broad
expression profiles for sPLA(2)-IIA and -IID. In sPLA(2)-IIA-deficient mice, the
expression of sPLA(2)-IIE was markedly enhanced in the lung and small intestine
upon endotoxin challenge, which contrasted with the reduced expression of sPLA(2)
IID mRNA. In situ hybridization analysis revealed elevation of sPLA(2)-IIE mRNA
at alveolar macrophage-like cells in the lung of endotoxin-treated mice. These
findings suggest a distinct functional role of novel sPLA(2)-IIE in the
progression of inflammatory processes.
PMID- 10681568
TI - Acetyl-CoA synthetase from the amitochondriate eukaryote Giardia lamblia belongs
to the newly recognized superfamily of acyl-CoA synthetases (Nucleoside
diphosphate-forming).
AB - The gene coding for the acetyl-CoA synthetase (ADP-forming) from the
amitochondriate eukaryote Giardia lamblia has been expressed in Escherichia coli.
The recombinant enzyme exhibited the same substrate specificity as the native
enzyme, utilizing acetyl-CoA and adenine nucleotides as preferred substrates and
less efficiently, propionyl- and succinyl-CoA. N- and C-terminal parts of the G.
lamblia acetyl-CoA synthetase sequence were found to be homologous to the alpha-
and beta-subunits, respectively, of succinyl-CoA synthetase. Sequence analysis of
homologous enzymes from various bacteria, archaea, and the eukaryote, Plasmodium
falciparum, identified conserved features in their organization, which allowed us
to delineate a new superfamily of acyl-CoA synthetases (nucleoside diphosphate
forming) and its signature motifs. The representatives of this new superfamily of
thiokinases vary in their domain arrangement, some consisting of separate alpha-
and beta-subunits and others comprising fusion proteins in alpha-beta or beta
alpha orientation. The presence of homologs of acetyl-CoA synthetase (ADP
forming) in such human pathogens as G. lamblia, Yersinia pestis, Bordetella
pertussis, Pseudomonas aeruginosa, Vibrio cholerae, Salmonella typhi,
Porphyromonas gingivalis, and the malaria agent P. falciparum suggests that they
might be used as potential drug targets.
PMID- 10681569
TI - Hormonal regulation of the phosphoenolpyruvate carboxykinase gene. Role of
specific CCAAT/enhancer-binding protein isoforms.
AB - The CCAAT/enhancer-binding protein alpha (C/EBP) is a transcription factor that
trans-activates a number of metabolically important genes. Previous work has
demonstrated that C/EBPalpha and C/EBPbeta have the potential to mediate the cAMP
responsiveness of phosphoenolpyruvate carboxykinase (PEPCK) in liver cells.
However, these studies used GAL4 fusion proteins and artificial promoter-reporter
gene vectors in transfection experiments; as a result, these studies only
indicated that both isoforms had the potential to mediate the hormonal response
and not which isoform actually participated in vivo. To address this issue, we
produced hepatoma cell lines that stably expressed either a dominant negative
inhibitor or antisense RNA for these two main liver C/EBP isoforms. Inhibition of
all C/EBP isoforms via expression of the dominant negative protein eliminated
cAMP responsiveness, and reduced glucocorticoid responsiveness, of the endogenous
PEPCK gene in hepatoma cells. Antisense directed against C/EBPalpha mRNA, which
reduced C/EBPalpha protein levels by nearly 80%, also significantly reduced the
cAMP responsiveness of the endogenous PEPCK promoter, whereas antisense directed
against C/EBPbeta was without effect. There was no major alteration in cAMP
signaling in the C/EBPalpha antisense cells, as cAMP induction of the C/EBPbeta
gene was similar to that in wild-type H4IIE cells. These data suggest that the
alpha-isoform of C/EBP is specifically utilized for mediating the cAMP
responsiveness of the PEPCK gene.
PMID- 10681570
TI - Sites of action of protein kinase C and phosphatidylinositol 3-kinase are
distinct in oxidized low density lipoprotein-induced macrophage proliferation.
AB - Oxidized low density lipoprotein (Ox-LDL) can induce macrophage proliferation in
vitro. To explore the mechanisms involved in this process, we reported that
activation of protein kinase C (PKC) is involved in its signaling pathway
(Matsumura, T., Sakai, M., Kobori, S., Biwa, T., Takemura, T., Matsuda, H.,
Hakamata, H., Horiuchi, S., and Shichiri, M. (1997) Arterioscler. Thromb. Vasc.
Biol. 17, 3013-3020) and that expression of granulocyte/macrophage colony
stimulating factor (GM-CSF) and its subsequent release in the culture medium are
important (Biwa, T., Hakamata, H., Sakai, M., Miyazaki, A., Suzuki, H., Kodama,
T., Shichiri, M., and Horiuchi, S. (1998) J. Biol. Chem. 273, 28305-28313).
However, a recent study also demonstrated the involvement of phosphatidylinositol
3-kinase (PI3K) in this process. In the present study, we investigated the role
of PKC and PI3K in Ox-LDL-induced macrophage proliferation. Ox-LDL-induced
macrophage proliferation was inhibited by 90% by a PKC inhibitor, calphostin C,
and 50% by a PI3K inhibitor, wortmannin. Ox-LDL-induced expression of GM-CSF and
its subsequent release were inhibited by calphostin C but not by wortmannin,
whereas recombinant GM-CSF-induced macrophage proliferation was inhibited by
wortmannin by 50% but not by calphostin C. Ox-LDL activated PI3K at two time
points (10 min and 4 h), and the activation at the second but not first point was
significantly inhibited by calphostin C and anti-GM-CSF antibody. Our results
suggest that PKC plays a role upstream in the signaling pathway to GM-CSF
induction, whereas PI3K is involved, at least in part, downstream in the
signaling pathway after GM-CSF induction.
PMID- 10681571
TI - Isolation of the ace1 gene encoding a Cys(2)-His(2) transcription factor involved
in regulation of activity of the cellulase promoter cbh1 of Trichoderma reesei.
AB - A genetic selection method was developed for the cloning of positive-acting
transcriptional regulatory genes in Saccharomyces cerevisiae. The method was
applied for the isolation of activators of Trichoderma reesei (Hypocrea jecorina)
cellulase genes. Activator genes were isolated from a T. reesei expression cDNA
library on the basis of the ability of their translation products to activate
transcription from the full-length T. reesei cbh1 promoter coupled to the S.
cerevisiae HIS3 gene and to support the growth of the yeast colonies in the
absence of histidine. Among the clones obtained was the ace1 gene encoding a
novel polypeptide, ACEI, that contains three zinc finger motifs of Cys(2)-His(2)
type. Possible ACEI homologues were found among expressed sequence tags of
Aspergillus and Neurospora. The ability of ACEI to bind to the cbh1 promoter was
further confirmed in the yeast one-hybrid system. In vitro binding and gel
mobility shift assays revealed several binding sites for the ACEI protein in the
cbh1 promoter. Disruption of the ace1 gene in T. reesei resulted in retarded
growth of the fungus on a cellulose-containing medium, on which cellulases are
normally highly expressed.
PMID- 10681572
TI - Identical or overlapping sequences in the primary structure of human alpha(2)
macroglobulin are responsible for the binding of nerve growth factor-beta,
platelet-derived growth factor-BB, and transforming growth factor-beta.
AB - alpha(2)-Macroglobulin (alpha(2)M) functions as a proteinase inhibitor and as a
carrier of diverse growth factors. In this study, we localized binding sites for
platelet-derived growth factor-BB (PDGF-BB) and nerve growth factor-beta (NGF
beta) to a linear sequence in the 180-kDa human alpha(2)M subunit which includes
amino acids 591-774. A glutathione S-transferase fusion protein containing amino
acids 591-774 (FP3) bound PDGF-BB and NGF-beta in ligand blotting assays whereas
five other fusion proteins, which collectively include amino acids 99-590 and 775
1451 did not. The K(D) values for PDGF-BB and NGF-beta binding to immobilized FP3
were 300 +/- 40 and 180 +/- 30 nM, respectively; these values were comparable
with those determined using methylamine-modified alpha(2)M, suggesting that
higher-order alpha(2)M structure is not necessary for PDGF-BB and NGF-beta
binding. PDGF-BB and NGF-beta blocked the binding of transforming growth factor
beta1 (TGF-beta1) to FP3. Furthermore, murinoglobulin, which is the only known
member of the alpha-macroglobulin family that does not bind TGF-beta, also failed
to bind PDGF-BB and NGF-beta. These results support the hypothesis that either a
single linear sequence in human alpha(2)M or overlapping sequences are
responsible for the binding of TGF-beta, PDGF-BB, and NGF-beta, even though there
is minimal sequence identity between these three growth factors. FP3 blocked the
binding of PDGF-BB to a purified chimeric protein, in which the extracellular
domain of the PDGF beta receptor was fused to the IgG(1) Fc domain, and to PDGF
receptors on NIH 3T3 cells. Thus, FP3 may inhibit the activity of PDGF-BB.
PMID- 10681573
TI - GD3 synthase gene expression in PC12 cells results in the continuous activation
of TrkA and ERK1/2 and enhanced proliferation.
AB - A rat pheochromocytoma cell line (PC12) transfected with ganglioside GD3 synthase
gene showed a marked change in the ganglioside profile and enhanced proliferation
and no response of neurite extension to nerve growth factor (NGF) stimulation. In
these transfectant cells, a continuous phosphorylation of TrkA and the activation
of ERK1/2 without NGF treatment were observed. Proliferation inhibition
experiments with kinase inhibitors such as herbimycin A, K-252a, and PD98059
revealed that the enhanced proliferation was actually due to the activation of
the Ras/MEK/ERK pathway. A TrkA dimer was detected in the GD3 synthase
transfectant cells regardless of NGF treatment by cross-linking and
immunoblotting. The increased expression of GD1b and GT1b in these transfectant
cells might induce the conformational change of TrkA to form a dimer and to be
activated continuously. These results may indicate regulatory roles of
gangliosides in cell proliferation under physiological and malignant processes.
PMID- 10681574
TI - Partitioning of serpin-proteinase reactions between stable inhibition and
substrate cleavage is regulated by the rate of serpin reactive center loop
insertion into beta-sheet A.
AB - The serpin family of serine proteinase inhibitors is a mechanistically unique
class of naturally occurring proteinase inhibitors that trap target enzymes as
stable covalent acyl-enzyme complexes. This mechanism appears to require both
cleavage of the serpin reactive center loop (RCL) by the proteinase and a
significant conformational change in the serpin structure involving rapid
insertion of the RCL into the center of an existing beta-sheet, serpin beta-sheet
A. The present study demonstrates that partitioning between inhibitor and
substrate modes of reaction can be altered by varying either the rates of RCL
insertion or deacylation using a library of serpin RCL mutants substituted in the
critical P(14) hinge residue and three different proteinases. We further
correlate the changes in partitioning with the actual rates of RCL insertion for
several of the variants upon reaction with the different proteinases as
determined by fluorescence spectroscopy of specific RCL-labeled inhibitor
mutants. These data demonstrate that the serpin mechanism follows a branched
pathway, and that the formation of a stable inhibited complex is dependent upon
both the rate of the RCL conformational change and the rate of enzyme
deacylation.
PMID- 10681575
TI - The itinerary of a vesicle component, Aut7p/Cvt5p, terminates in the yeast
vacuole via the autophagy/Cvt pathways.
AB - Aminopeptidase I (API) is delivered to the yeast vacuole by one of two
alternative pathways, cytoplasm to vacuole targeting (Cvt) or autophagy,
depending on nutrient conditions. Genetic, morphological, and biochemical studies
indicate that the two pathways share many of the same molecular components. The
Cvt pathway functions during vegetative growth, while autophagy is induced during
starvation. Both pathways involve the formation of cytosolic vesicles that fuse
with the vacuole. In either case, the mechanism of vesicle formation is not
known. Autophagic uptake displays a greater capacity for cytosolic protein
sequestration. This suggests the involvement of an inducible protein(s) that
allows the vesicle-forming machinery to adapt to the increased degradative needs
of the cell. We have analyzed the biosynthesis of Aut7p, a protein required for
both pathways. We find Aut7p expression is induced by nitrogen starvation. Aut7p
is degraded by a process dependent on both proteinase A and Cvt/autophagy
components. Protease accessibility assays demonstrate that Aut7p is located
within vesicles in strains defective in vesicle delivery or breakdown. Finally,
the aut7/cvt5 mutant accumulates precursor API at a stage prior to vesicle
completion. These data suggest that Aut7p is induced during autophagy and
delivered to the vacuole together with precursor API by Cvt/autophagic vesicles.
PMID- 10681576
TI - Limitation in electron transfer in photosystem I donor side mutants of
Chlamydomonas reinhardtii. Lethal photo-oxidative damage in high light is
overcome in a suppressor strain deficient in the assembly of the light harvesting
complex.
AB - Strains of Chlamydomonas reinhardtii lacking the PsaF gene or containing the
mutation K23Q within the N-terminal part of PsaF are sensitive to high light
(>400 microE m(-2) s(-1)) under aerobic conditions. In vitro experiments indicate
that the sensitivity to high light of the isolated photosystem I (PSI) complex
from wild type and from PsaF mutants is similar. In vivo measurements of
photochemical quenching and oxygen evolution show that impairment of the donor
side of PSI in the PsaF mutants leads to a diminished linear electron transfer
and/or a decrease of photosystem II (PSII) activity in high light.
Thermoluminescence measurements indicate that the PSII reaction center is
directly affected under photo-oxidative stress when the rate of electron transfer
becomes limiting in the PsaF-deficient strain and in the PsaF mutant K23Q. We
have isolated a high light-resistant PsaF-deficient suppressor strain that has a
high chlorophyll a/b ratio and is affected in the assembly of light-harvesting
complex. These results indicate that under high light a functionally intact donor
side of PSI is essential for protection of C. reinhardtii against photo-oxidative
damage when the photosystems are properly connected to their light-harvesting
antennae.
PMID- 10681577
TI - The insulin-like growth factors (IGFs) I and II bind to articular cartilage via
the IGF-binding proteins.
AB - Bovine articular cartilage discs (3 mm diameter x 400 micrometer thick) were
equilibrated in buffer containing (125)I-insulin-like growth factor (IGF)-I (4
degrees C) +/- unlabeled IGF-I or IGF-II. Competition for binding to cartilage
discs by each unlabeled IGF was concentration-dependent, with ED(50) values for
inhibition of (125)I-IGF-I binding of 11 and 10 nM for IGF-I and -II,
respectively, and saturation by 50 nM. By contrast, an analog of IGF-I with very
low affinity for the insulin-like growth factor-binding proteins (IGF-BPs), des
(1-3)-IGF-I, was not competitive with (125)I-IGF-I for cartilage binding even at
100-400 nM. Binding of the (125)I-labeled IGF-II isoform to cartilage was
competed for by unlabeled IGF-I or -II, with ED(50)s of 160 and 8 nM,
respectively. This probably reflected the differential affinities of the
endogenous IGF-BPs (IGF-BP-6 and -2) for IGF-II/IGF-I. Transport of (125)I-IGF-I
was also measured in an apparatus that allows diffusion only across the discs
(400 micrometer), by addition to one side and continuous monitoring of efflux on
the other side. The time lag for transport of (125)I-IGF was 266 min, an order of
magnitude longer than the theoretical prediction for free diffusion in the
matrix. (125)I-IGF-I transport then reached a steady state rate (% efflux of
total added (125)I-IGF/unit time), which was subsequently accelerated
approximately 2-fold by addition of an excess of unlabeled IGF-I. Taken together,
these results indicate that IGF binding to cartilage, mostly through the IGF-BPs,
regulates the transport of IGFs in articular cartilage, probably contributing to
the control of their paracrine activities.
PMID- 10681578
TI - Proteinase inhibitor 9, an inhibitor of granzyme B-mediated apoptosis, is a
primary estrogen-inducible gene in human liver cells.
AB - Although liver is an estrogen target tissue, the number of hepatic genes known to
be directly induced by estrogen is very small. We identified proteinase inhibitor
9, or PI-9, as being rapidly and strongly induced by estrogen in an estrogen
receptor-positive human liver cell line (HepG2-ER7). Since PI-9 mRNA was also
induced by estrogen in a human liver biopsy sample, PI-9 is a genuine estrogen
regulated human gene. PI-9 is a potent inhibitor of granzyme B and of granzyme B
mediated apoptosis. Estrogens induced PI-9 mRNA within 2 h, PI-9 mRNA levels
reached a plateau of 30-40-fold induction in 4 h, and induction was not blocked
by cycloheximide, indicating that induction of PI-9 mRNA is a primary response.
The antiestrogen trans-hydroxytamoxifen was a partial agonist for PI-9 mRNA
induction, whereas the antiestrogen ICI 182, 780 was a pure antagonist. Western
blot analysis showed that estrogen strongly increases PI-9 protein levels.
Inhibition of transcription with actinomycin D resulted in identical rates of PI
9 mRNA decay in the presence and absence of estrogen. We isolated genomic clones
containing the PI-9 promoter region, identified a putative transcription start
site, and carried out transient transfections of PI-9-luciferase reporter gene
constructs. The estrogen, moxestrol, elicited a robust induction from the PI-9
luciferase reporter. Mutational inactivation of three potential imperfect
estrogen response elements in the PI-9 5'-flanking region had no effect on
moxestrol estrogen receptor induction.
PMID- 10681579
TI - Dissecting the interactions between NTF2, RanGDP, and the nucleoporin XFXFG
repeats.
AB - We have used a range of complementary biochemical and biophysical methods to
investigate the interactions between nuclear transport factor 2 (NTF2), the Ras
family GTPase Ran, and XFXFG nucleoporin repeats that are crucial for nuclear
trafficking. Microcalorimetry, microtiter plate binding, and fluorescence
quenching in solution are all consistent with the binding constant for the NTF2
RanGDP interaction being in the 100 nM range, whereas the interaction between
NTF2 and XFXFG repeat-containing nucleoporins such as Nsp1p is in the 1 microM
range. Although the accumulation of NTF2 at the nuclear envelope is enhanced by
RanGDP, we show that Ran binding does not alter the affinity of NTF2 for
nucleoporins nor does the binding of nucleoporins alter the affinity of NTF2 for
RanGDP. These results indicate that, instead, Ran increases the binding of NTF2
to nucleoporins by another mechanism, most probably by Ran itself binding to
nucleoporins and NTF2 binding to this nuclear pore-associated Ran.
PMID- 10681580
TI - A novel conformation of the herpes simplex virus origin of DNA replication
recognized by the origin binding protein.
AB - The Herpes simplex virus type I origin binding protein (OBP) is a sequence
specific DNA-binding protein and a dimeric DNA helicase encoded by the UL9 gene.
It is required for the activation of the viral origin of DNA replication oriS.
Here we demonstrate that the linear double-stranded form of oriS can be converted
by heat treatment to a stable novel conformation referred to as oriS*. Studies
using S1 nuclease suggest that oriS* consists of a central hairpin with an AT
rich sequence in the loop. Single-stranded oligonucleotides corresponding to the
upper strand of oriS can adopt the same structure. OBP forms a stable complex
with oriS*. We have identified structural features of oriS* recognized by OBP.
The central oriS palindrome as well as sequences at the 5' side of the oriS
palindrome were required for complex formation. Importantly, we found that
mutations that have been shown to reduce oriS-dependent DNA replication also
reduce the formation of the OBP-oriS* complex. We suggest that oriS* serves as an
intermediate in the initiation of DNA replication providing the initiator protein
with structural information for a selective and efficient assembly of the viral
replication machinery.
PMID- 10681581
TI - A minimized human integrin alpha(5)beta(1) that retains ligand recognition.
AB - Two isolated recombinant fragments from human integrin alpha(5)beta(1)
encompassing the FG-GAP repeats III to VII of alpha(5) and the insertion-type
domain from beta(1), respectively, are structurally well defined in solution,
based on CD evidence. Divalent cation binding induces a conformational adaptation
that is achieved by Ca(2+) or Mg(2+) (or Mn(2+)) with alpha(5) and only by Mg(2+)
(or Mn(2+)) with beta(1). Mn(2+) bound to beta(1) is highly hydrated (
approximately 3 water molecules), based on water NMR relaxation, in agreement
with a metal ion-dependent adhesion site-type metal coordination. Each fragment
saturated with Mg(2+) (or Mn(2+)) binds a recombinant fibronectin ligand in an
RGD-dependent manner. A conformational rearrangement is induced on the
fibronectin ligand upon binding to the alpha(5), but not to the beta(1) fragment,
based on CD. Ligand binding results in metal ion displacement from beta(1). Both
alpha(5) and beta(1) fragments form a stable heterodimer (alpha(5)beta(1) mini
integrin) that retains ligand recognition to form a 1:1:1 ternary complex, in the
presence of Mg(2+), and induces a specific conformational adaptation of the
fibronectin ligand. A two-site model for RGD binding to both alpha and beta
integrin components is inferred from our data using low molecular weight RGD
mimetics.
PMID- 10681582
TI - Association of human origin recognition complex 1 with chromatin DNA and nuclease
resistant nuclear structures.
AB - An origin recognition complex (ORC) consisting of six polypeptides has been
identified as a DNA replication origin-binding factor in Saccharomyces
cerevisiae. Homologues of ORC subunits have been discovered among eukaryotes, and
we have prepared monoclonal antibodies against a human homologue of ORC1 (hORC1)
to study its localization in human cells. It was thus found to associate with
nuclei throughout the cell cycle and to be resistant to nonionic detergent
treatment, in contrast to MCM proteins, which are other replication factors, the
association of which with nuclei is clearly dependent on the phase of the cell
cycle. A characteristic feature of hORC1 is dissociation by NaCl in a narrow
concentration range around 0.25 M, suggesting interaction with some specific
partner(s) in nuclei. Nuclease treatment experiments and UV cross-linking
experiments further indicated interaction with both nuclease-resistant nuclear
structures and chromatin DNA. Although its DNA binding was unaffected, some
variation in the cell cycle was apparent, the association with nuclear structures
being less stable in the M phase. Interestingly, the less stable association
occurred concomitantly with hyperphosphorylation of hORC1, suggesting that this
hyperphosphorylation may be involved in M phase changes.
PMID- 10681583
TI - Differential effect of Rac and Cdc42 on p38 kinase activity and cell cycle
progression of nonadherent primary mouse fibroblasts.
AB - The Rho GTPases play an important role in transducing signals linking plasma
membrane receptors to the organization of the cytoskeleton and also regulate gene
transcription. Here, we show that expression of constitutively active Ras or
Cdc42, but not RhoA, RhoG, and Rac1, is sufficient to cause anchorage-independent
cell cycle progression of mouse embryonic fibroblasts. However, in anchorage free
conditions, whereas activation of either Cdc42 or Ras results in cyclin A
transcription and cell cycle progression, Cdc42 is not required for Ras-mediated
cyclin A induction, and the two proteins act in a synergistic manner in this
process. Surprisingly, the ability of Cdc42 to induce p38 MAPK activity in
suspended mouse embryonic fibroblast was impaired. Moreover, inhibition of p38
activity allowed Rac1 to induce anchorage-independent cyclin A transcription,
indicating that p38 MAPK has an inhibitory function on cell cycle progression of
primary fibroblasts. Finally, a Rac mutant, which is unable to induce
lamellipodia and focal complex formation, promoted cyclin A transcription in the
presence of SB203580, suggesting that the organization of the cytoskeleton is not
required for anchorage-independent proliferation. This demonstrates a novel
function for Cdc42, distinct from that of Rac1, in the control of cell
proliferation.
PMID- 10681584
TI - Repressed expression of the human xanthine oxidoreductase gene. E-box and TATA
like elements restrict ground state transcriptional activity.
AB - Studies were initiated to address the basis for the low xanthine oxidoreductase
(XOR) activity in humans relative to nonprimate mammalian species. The expression
of the XOR in humans is strikingly lower than in mice, and both transcription
rates and core promoter activity of the gene are repressed. Analysis of human XOR
promoter activity in hepatocytes and vascular endothelial cells showed that the
region from -258 to -1 contains both repressor and activator binding regions
regulating core promoter activity. The region between -138 and -1 is necessary
and sufficient for initiating, and the region between -258 and -228 is critical
for restricting core promoter activity. Within the latter region, site-directed
mutations identified a consensus sequence "acacaggtgtgg" (-242 to -230) that
contains an E-box that binds a repressor. In addition, the TATA-like element is
also required to restrict promoter activity and TFIID binds to this site. The
results demonstrate that both an E-box and TATA-like element are required to
restrict gene activity. A model is proposed to account for human XOR regulation.
PMID- 10681585
TI - Induction of light chain replacement in human plasma cells by caffeine is
independent from both the upregulation of RAG protein expression and germ line
transcription.
AB - When some human plasma cell lines are cultured with concanavalin A, the original
light chain is replaced with another light chain which results from secondary VJ
recombination (light chain shifting). We examined various intracellular factors
involved in the induction of light chain shifting. Light chain shifting can be
induced upon treatment with agents with phosphatase inhibitory activity such as
caffeine and okadaic acid. Although the plasma cells used express both RAG-1 and
RAG-2, the expression level of these proteins was not affected by caffeine or
okadaic acid. Transcription of the germ line locus, which correlates to the locus
activation for rearrangement, is also not influenced by phosphatase inhibition.
However, the amount of signal broken-ended DNA intermediates generated during
V(D)J rearrangement was shown to increase upon caffeine or okadaic acid
treatment. The inhibitory activity of caffeine on phosphatase was the same as
okadaic acid. However, caffeine exhibited much higher activity for VJ coding
joint formation than okadaic acid. Therefore, although phosphatase inhibition
might act, in part, on a mechanism by which V(D)J recombinase activity is
regulated within the human plasma cells, other factor(s) are probably also
involved in the process.
PMID- 10681586
TI - Isolation, structure, synthesis, and activity of a new member of the calcitonin
gene-related peptide family from frog skin and molecular cloning of its
precursor.
AB - Calcitonin gene-related peptide has been extracted from the skin exudate of a
single living specimen of the frog Phyllomedusa bicolor and purified to
homogeneity by a two-step protocol. A total volume of 250 microl of exudate
yielded 380 microg of purified peptide. Mass spectrometric analysis and gas phase
sequencing of the purified peptide as well as chemical synthesis and cDNA
analysis were consistent with the structure SCDTSTCATQRLADFLSRSGGIGSPDFVPTDVSANSF
amide and the presence of a disulfide bridge linking Cys(2) and Cys(7). The skin
peptide, named skin calcitonin gene-related peptide, differs significantly from
all other members of the calcitonin gene-related peptide family of peptides at
nine positions but binds with high affinity to calcitonin gene-related peptide
receptors in the rat brain and acts as an agonist in the rat vas deferens
bioassay with potencies equal to those of human CGRP. Reverse transcriptase
polymerase chain reaction coupled with cDNA cloning and sequencing demonstrated
that skin calcitonin gene-related peptide isolated in the skin is identical to
that present in the frog's central and enteric nervous systems. These data, which
indicate for the first time the existence of calcitonin gene-related peptide in
the frog skin, add further support to the brain-skin-gut triangle hypothesis as a
useful tool in the identification and/or isolation of mammalian peptides that are
present in the brain and other tissues in only minute quantities.
PMID- 10681587
TI - Subunit interactions in yeast transcription/repair factor TFIIH. Requirement for
Tfb3 subunit in nucleotide excision repair.
AB - A yeast strain harboring a temperature-sensitive allele of TFB3 (tfb3(ts)), the
38-kDa subunit of the RNA polymerase II transcription/nucleotide excision repair
factor TFIIH, was found to be sensitive to ultraviolet (UV) radiation and
defective for nucleotide excision repair in vitro. Interestingly, tfb3(ts) failed
to grow on medium containing caffeine. A comprehensive pairwise two-hybrid
analysis between yeast TFIIH subunits identified novel interactions between Rad3
and Tfb3, Tfb4 and Ssl1, as well as Ssl2 and Tfb2. These interactions have
facilitated a more complete model of the structure of TFIIH and the nucleotide
excision repairosome.
PMID- 10681588
TI - Identification and characterization of basal and cyclic AMP response elements in
the promoter of the rat GTP cyclohydrolase I gene.
AB - 5812 base pairs of rat GTP cyclohydrolase I (GTPCH) 5'-flanking region were
cloned and sequenced, and the transcription start site was determined for the
gene in rat liver. Progressive deletion analysis using transient transfection
assays of luciferase reporter constructs defined the core promoter as a highly
conserved 142-base pair GC-rich sequence upstream from the cap site. DNase I
footprint analysis of this region revealed (5' --> 3') a Sp1/GC box, a
noncanonical cAMP-response element (CRE), a CCAAT-box, and an E-box.
Transcription from the core promoter in PC12 but not C6 or Rat2 cells was
enhanced by incubation with 8-bromo-cyclic AMP. Mutagenesis showed that both the
CRE and CCAAT-box independently contribute to basal and cAMP-dependent activity.
The combined CRE and CCAAT-box cassette was also found to enhance basal
transcription and confer cAMP sensitivity on a heterologous minimal promoter. The
addition of the Sp1/GC box sequence to this minimal promoter construct inhibited
basal transcription without affecting the cAMP response. EMSA showed that nuclear
proteins from PC12 but not C6 or Rat2 cells bind the CRE as a complex containing
activating transcription factor (ATF)-4 and CCAAT enhancer-binding protein beta,
while both PC12 and C6 cell nuclear extracts were recruited by the CCAAT-box as a
complex containing nuclear factor Y. Overexpression of ATF-4 in PC12 cells was
found to transactivate the GTPCH promoter response to cAMP. These studies suggest
that the elements required for cell type-specific cAMP-dependent enhancement of
gene transcription are located along the GTPCH core promoter and include the CRE
and adjacent CCAAT-box and the proteins ATF-4, CCAAT enhancer-binding protein
beta, and nuclear factor Y.
PMID- 10681589
TI - Structural analysis of alpha-enolase. Mapping the functional domains involved in
down-regulation of the c-myc protooncogene.
AB - Myc-binding protein-1 (MBP-1) is a 37-kDa protein with sequence homology to the
3' portion of the alpha-enolase gene. alpha-Enolase is a 48-kDa protein, which
plays a critical role in the glycolytic pathway. MBP-1 binds to the c-myc P2
promoter and down-regulates c-myc expression. We have investigated the role of
alpha-enolase in regulation of the c-myc protooncogene. RNase protection assay
shows that alpha-enolase is transcribed into a single RNA species in HeLa cells.
A start codon, 400 base pairs downstream of the alpha-enolase ATG, corresponds to
the MBP-1 ATG, suggesting that MBP-1 is an alternative translation initiation
product of the alpha-enolase RNA. Domain mapping was performed using constructs
containing truncations of the alpha-enolase gene. In vitro binding to the c-myc
gene was abolished after deletion of the N-terminal portion of alpha-enolase. In
order to determine the relationship between DNA binding activity and
transcription inhibition, we performed co-transfection assays in HeLa cells.
These studies confirmed that an N-terminal deletion of alpha-enolase is unable to
down-regulate c-myc promoter activity. Our data suggest that alpha-enolase plays
an important role in regulation of c-myc promoter activity in the form of an
alternative translation product MBP-1, which is distinct from its role as a
glycolytic enzyme.
PMID- 10681590
TI - ZAP-70 is essential for the T cell antigen receptor-induced plasma membrane
targeting of SOS and Vav in T cells.
AB - Translocation of the SOS and Vav GDP/GTP exchange factors proximal to Ras and Rac
GTPases localized in the plasma membrane glycolipid-enriched microdomains is a
pivotal step required for T cell antigen receptor-induced T cell activation. Here
we demonstrate that the T cell antigen receptor zeta-chain-associated ZAP-70
kinase and T cell antigen receptor zeta-chain immunoreceptor tyrosine-based
activation motifs are essential for the membrane recruitment of SOS and Vav.
Plasma membrane targeting of SOS or Vav begins with the assembly of ZAP-70 with
Grb-2 and SOS. The subsequent tyrosine phosphorylation of LAT (linker for
activation of T cell) by ZAP-70 leads to a shift in equilibrium from the ZAP
70.Grb-2.SOS(Vav) complex to the (Vav)SOS.Grb-2.LAT complex. This shift results
in the targeting of SOS and Vav into glycolipid-enriched microdomains and
initiation of the Ras and Rac signaling cascades involved in T cell activation,
proliferation, and cytokine production.
PMID- 10681591
TI - Differential mechanisms of nuclear receptor regulation by receptor-associated
coactivator 3.
AB - Steroid and nuclear receptor coactivators (NCoAs) have been implicated in the
regulation of nuclear receptor function by enhancing ligand-dependent
transcriptional activation of target gene expression. We have previously isolated
receptor-associated coactivator 3 (RAC3), which belongs to the steroid receptor
coactivator family. In this study, we investigated the differential mechanisms by
which RAC3 interacts with and modulates the transcriptional activity of different
nuclear receptors. We found that the vitamin D receptor (VDR) and estrogen
receptor beta interact with different alpha-helical LXXLL motifs of RAC3.
Peptides corresponding to these motifs have diverse affinities for the VDR and
estrogen receptor beta, and mutation of specific motifs differentially impairs
the ability of RAC3 to interact with these receptors in vitro. Consequently,
these mutations inhibit the enhancement of transcriptional activation by these
receptors in vivo. Furthermore, we found that the activation function-2 (AF-2)
domain of the retinoid X receptor interferes with RAC3 binding to a DNA-bound
VDR/retinoid X receptor (RXR) heterodimer, whereas the VDR AF-2 domain is
required for this interaction. These results suggest a receptor-specific binding
preference for the different LXXLL motifs of RAC3, which may provide flexibility
for RAC3 to differentially regulate the function of different nuclear receptors.
PMID- 10681592
TI - SHP2 association with VE-cadherin complexes in human endothelial cells is
regulated by thrombin.
AB - Thrombin-mediated changes in endothelial cell adherens junctions modulate
vascular permeability. We demonstrate that the nonreceptor protein-tyrosine
phosphatase SHP2 co-precipitates with VE-cadherin complexes in confluent,
quiescent human umbilical vein endothelial cells. Ligand-binding blots using a
SHP2-glutathione S-transferase fusion peptide established that SHP2 associates
selectively with beta-catenin in VE-cadherin complexes. Thrombin treatment of
human umbilical vein endothelial cells promotes SHP2 tyrosine phosphorylation and
dissociation from VE-cadherin complexes. The loss of SHP2 from the cadherin
complexes correlates with a dramatic increase in the tyrosine phosphorylation of
beta-catenin, gamma-catenin, and p120-catenin complexed with VE-cadherin. We
propose that thrombin regulates the tyrosine phosphorylation of VE-cadherin
associated beta-catenin, gamma-catenin, and p120-catenin by modulating the
quantity of SHP2 associated with VE-cadherin complexes. Such changes in adherens
junction complex composition likely underlie thrombin-elicited alterations in
endothelial monolayer permeability.
PMID- 10681593
TI - Constitutive death of platelets leading to scavenger receptor-mediated
phagocytosis. A caspase-independent cell clearance program.
AB - Apoptosis is a physiological program for the deletion of cells in which caspases
govern events leading to safe clearance by phagocytes. However, a growing weight
of evidence now suggests that not all forms of programmed cell death are caspase
dependent. We now report a complete and constitutive but caspase-independent
program for the specific phagocytic clearance of intact effete platelets,
anucleated blood cells of critical importance in health and disease. Platelets
aged in vitro not only exhibited increased expression of proapoptotic Bak and Bax
but also evidenced constitutive diminution of function such as decreased
aggregation to ADP, which was accelerated by culture in the absence of plasma.
This abrogation of cell function in plasma-deprived platelets was associated with
morphological and biochemical features similar to those of granulocyte apoptosis,
that is, cytoplasmic condensation, plasma membrane changes including exposure of
phosphatidylserine and the granule protein P-selectin, and recognition by
phagocyte scavenger receptors. However, and in contrast with constitutive death
of other inflammatory blood cells by apoptosis, these events were not affected by
caspase inhibitors, nor was there evidence of caspase-3 activation either by
hydrolysis of analog peptide substrates or Western blot analysis, serving to
emphasize that neither programmed cell death nor clearance by phagocytes need
involve caspases.
PMID- 10681594
TI - Expression of distinct ERG proteins in rat, mouse, and human heart. Relation to
functional I(Kr) channels.
AB - One form of inherited long QT syndrome, LQT2, results from mutations in HERG1,
the human ether-a-go-go-related gene, which encodes a voltage-gated K(+) channel
alpha subunit. Heterologous expression of HERG1 gives rise to K(+) currents that
are similar (but not identical) to the rapid component of delayed rectification,
I(Kr), in cardiac myocytes. In addition, N-terminal splice variants of HERG1 and
MERG1 (mouse ERG1) referred to as HERG1b and MERG1b have been cloned and
suggested to play roles in the generation of functional I(Kr) channels. In the
experiments here, antibodies generated against HERG1 were used to examine ERG1
protein expression in heart and in brain. In Western blots of extracts of QT-6
cells expressing HERG1, MERG1, or RERG1 (rat ERG1) probed with antibodies
targeted against the C terminus of HERG1, a single 155-kDa protein is identified,
whereas a 95-kDa band is evident in blots of extracts from cells expressing
MERG1b or HERG1b. In immunoblots of fractionated rat (and mouse) brain and heart
membrane proteins, however, two prominent high molecular mass proteins of 165 and
205 kDa were detected. Following treatment with glycopeptidase F, the 165- and
205-kDa proteins were replaced by two new bands at 175 and 130 kDa, suggesting
that ERG1 is differentially glycosylated in rat/mouse brain and heart. In human
heart, a single HERG1 protein with an apparent molecular mass of 145 kDa is
evident. In rats, ERG1 protein (and I(Kr)) expression is higher in atria than
ventricles, whereas in humans, HERG1 expression is higher in ventricular, than
atrial, tissue. Taken together, these results suggest that the N-terminal
alternatively spliced variants of ERG1 (i.e. ERG1b) are not expressed at the
protein level in rat, mouse, or human heart and that these variants do not,
therefore, play roles in the generation of functional cardiac I(Kr) channels.
PMID- 10681595
TI - Isolation and characterization of cDNA clones for the e1beta and E2 subunits of
the branched-chain alpha-ketoacid dehydrogenase complex in Arabidopsis.
AB - Branched-chain alpha-ketoacid dehydrogenase (BCKDH) has been known in mammals to
be a key enzyme of the catabolic pathway of branched-chain amino acids. We have
isolated two cDNA clones encoding the E1beta and E2 subunits of BCKDH,
respectively, from Arabidopsis thaliana. Proteins encoded in these cDNA sequences
had putative mitochondrial targeting sequences and conserved domains reported for
their mammalian counterparts. Northern blot and immunoblot analyses showed that
transcripts from the respective genes and E2 protein markedly accumulated in
leaves kept in the dark. We found that the activity of BCKDH in the leaf extracts
also increased when plants were placed in the dark. Addition of sucrose to
detached leaves inhibited the accumulation of transcripts, whereas application of
a photosynthesis inhibitor strongly induced the expression of these genes even
under light illumination. These observations indicate that the cellular sugar
level is likely responsible for the dark-induced expression of these genes. The
transcript levels of these genes were also high in senescing leaves, in which
photosynthetic activity is low and free amino acids from degraded protein are
likely to serve as an alternative energy source.
PMID- 10681596
TI - Membrane targeting and cytoplasmic sequestration in the spatiotemporal
localization of human protein kinase C alpha.
AB - In order to map the molecular determinants that dictate the subcellular
localization of human protein kinase C alpha (hPKCalpha), full-length and
deletion mutants of hPKCalpha were tagged with the green fluorescent protein
(GFP) and transiently expressed in GH3B6 cells. We found that upon thyrotropin
releasing hormone (TRH) or phorbol 12-myristate 13-acetate stimulation, hPKCalpha
GFP was localized exclusively in regions of cell-cell contacts. Surprisingly,
PKCalpha failed to translocate in single cells despite the presence of TRH
receptors, as attested by the TRH-induced rise in intracellular calcium
concentration in these cells. TRH-stimulated translocation of hPKCalpha-GFP from
the cytoplasm to cell-cell contacts was a biphasic process: a fast (measured in
seconds) and transient phase, followed by a slower (approximately 1 hour) and
long lasting phase. The latter and the translocation induced by phorbol 12
myristate 13-acetate absolutely required the N-terminal V1 region. In contrast to
the full-length hPKCalpha, the N-terminal regulatory domain alone or associated
with the V3 hinge region was spontaneously and uniformly localized at the plasma
membrane of single and apposed cells. However, treatment with the calcium
chelator BAPTA/AM induced a differential cytoplasmic/nuclear redistribution of
the regulatory domain, depending on its association with V3, which suggests the
existence of a mechanism controlling the cytoplasmic sequestration of inactive
hPKCalpha and involving the V3 region. By using other deletion mutants, we were
able to map the sequence required for this sequestration to the C2+V3 regions.
This work points to the existence of a complex interplay between membrane
targeting and cytoplasmic sequestration in the control of the spatiotemporal
localization of hPKCalpha.
PMID- 10681597
TI - Impaired kit- but not FcepsilonRI-initiated mast cell activation in the absence
of phosphoinositide 3-kinase p85alpha gene products.
AB - The class I(A) phosphoinositide 3-kinases (PI3Ks) consist of a 110-kDa catalytic
domain and a regulatory subunit encoded by the p85alpha, p85beta, or p55gamma
genes. We have determined the effects of disrupting the p85alpha gene on the
responses of mast cells stimulated by the cross-linking of Kit and FcepsilonRI,
receptors that reflect innate and adaptive responses, respectively. The absence
of p85alpha gene products partially inhibited Kit ligand/stem cell factor-induced
secretory granule exocytosis, proliferation, and phosphorylation of the
serine/threonine kinase Akt. In contrast, p85alpha gene products were not
required for FcepsilonRI-initiated exocytosis and phosphorylation of Akt.
LY294002, which inhibits all classes of PI3Ks, strongly suppressed Kit- and
FcepsilonRI-induced responses in p85alpha -/- mast cells, revealing the
contribution of another PI3K family member(s). In contrast to B lymphocytes, mast
cell proliferation was not dependent on Bruton's tyrosine kinase, a downstream
effector of PI3K, revealing a distinct pathway of PI3K-dependent proliferation in
mast cells. Our findings represent the first example of receptor-specific usage
of different PI3K family members in a single cell type. In addition, because Kit-
but not FcepsilonRI-initiated signaling is associated with mast cell
proliferation, the results provide evidence that distinct biologic functions
signaled by these two receptors may reflect differential usage of PI3Ks.
PMID- 10681598
TI - The goodpasture autoantigen. Identification of multiple cryptic epitopes on the
NC1 domain of the alpha3(IV) collagen chain.
AB - Goodpasture (GP) disease is an autoimmune disorder in which autoantibodies
against the alpha3(IV) chain of type IV collagen bind to the glomerular and
alveolar basement membranes, causing progressive glomerulonephritis and pulmonary
hemorrhage. Two major conformational epitope regions have been identified on the
noncollagenous domain of type IV collagen (NC1 domain) of the alpha3(IV) chain as
residues 17-31 (E(A)) and 127-141 (E(B)) (Netzer, K.-O. et al. (1999) J. Biol.
Chem. 274, 11267-11274). To determine whether these regions are two distinct
epitopes or form a single epitope, three GP sera were fractionated by affinity
chromatography on immobilized NC1 chimeras containing the E(A) and/or the E(B)
region. Four subpopulations of GP antibodies with distinct epitope specificity
for the alpha3(IV)NC1 domain were thus separated and characterized. They were
designated GP(A), GP(B), GP(AB), and GP(X), to reflect their reactivity with E(A)
only, E(B) only, both regions, and neither, respectively. Hence, regions E(A) and
E(B) encompass critical amino acids that constitute three distinct epitopes for
GP(A), GP(B), and GP(AB) antibodies, respectively, whereas the epitope for GP(X)
antibodies is located in a different unknown region. The GP(A) antibodies were
consistently immunodominant, accounting for 60-65% of the total immunoreactivity
to alpha3(IV)NC1; thus, they probably play a major role in pathogenesis. Regions
E(A) and E(B) are held in close proximity because they jointly form the epitope
for Mab3, a monoclonal antibody that competes for binding with GP autoantibodies.
All GP epitopes are sequestered in the hexamer configuration of the NC1 domain
found in tissues and are inaccessible for antibody binding unless dissociation of
the hexamer occurs, suggesting a possible mechanism for etiology of GP disease.
GP antibodies have the capacity to extract alpha3(IV)NC1 monomers, but not
dimers, from native human glomerular basement membrane hexamers, a property that
may be of fundamental importance for the pathogenesis of the disease.
PMID- 10681599
TI - Metalloproteolytic release of endothelial cell protein C receptor.
AB - Previous studies observed that there is about 100 ng/ml soluble endothelial cell
protein C receptor (EPCR) in human plasma and that the levels increase in
inflammatory diseases. In this study we examine the potential mechanisms involved
in release of EPCR from cells. We find that EPCR is released from the surface of
endothelium and transfected 293 cells by a metalloprotease in a constitutive
fashion. The mass of soluble EPCR is 4 kDa less than intact EPCR. Release is
blocked by either the hydroxamic acid based inhibitor, KD-IX-73-4 or by 1,10
phenanthroline, but not by matrix metalloprotease inhibitors. Release is
stimulated by phorbol 12-myristate 13-acetate, thrombin, interleukin-1beta, and
hydrogen peroxide. Stimulation with these agents reduces EPCR expression levels
sufficiently to decrease the rate of protein C activation to a limited extent.
The influence of phorbol 12-myristate 13-acetate on both EPCR release and
inhibition of protein C activation are enhanced by microtubule disruption with
nocodazole. EPCR release is augmented by transfection of EPCR expressing 293
cells with caveolin, suggesting that release is caveolae dependent. These studies
indicate that metalloproteolytic release of EPCR is a highly regulated process
that is sensitive to both coagulation factors and inflammatory mediators.
PMID- 10681601
TI - Nitric oxide synthase expression in the opossum superior colliculus: a
histochemical, immunohistochemical and biochemical study.
AB - The expression of neuronal nitric oxide synthase (nNOS) in the superior
colliculus (SC) of the opossum Didelphis marsupialis was studied by NADPH
diaphorase (NADPH-d) histochemistry and nNOS immunohistochemistry. In addition,
the activity of nNOS was quantified by measurement of [(3)H]-L-arginine
conversion to [(3)H]-L-citrulline in tissue extracts from SC superficial layers
in opossums and rats. Our results show that the number of NADPH-d stained cells
was small and virtually identical in stratum opticum (SO) and stratum griseum
superficiale (SGS) and their staining was very light, particularly in SGS.
Neuropil staining was heavier in the stratum zonale (SZ) than in SGS or SO. The
intermediate and deep layers contained heavily stained cells and moderate
neuropil staining. Surprisingly, nNOS-immunoreactive cells were far more numerous
than NADPH-d+ cells in every layer. The production of [(3)H]-L-citrulline from
[(3)H]-L-arginine in tissue extracts enriched in superficial layers indicated
that nNOS specific activity is as high in the opossum as in the rat. Our results
suggest that the location of nNOS-expressing neurons in retino-receptive layers
may be related to inter-specific differences in the processing of visual
information.
PMID- 10681602
TI - Relative medial and dorsal cortex volume in relation to foraging ecology in
congeneric lizards.
AB - The need to locate distributed resources such as mates, food, and nests is
correlated with an enlarged hippocampus in many mammalian and avian species. This
correlation is believed to be a consequence of selection for spatial ability.
Little is known about how such ecological needs affect non-mammalian, non-avian
species. In lizards, the putative hippocampal homologues are the dorsal cortex
(DC) and medial cortex (MC). We examined the relationship between foraging
ecology and the size of the DC and MC in congeneric male lizards. We predicted
based on the mammalian and avian literature that Acanthodactylus boskianus, an
active forager that captures clumped, immobile prey would have a larger MC and DC
than A. scutellatus, a sit-and-wait predator, that captures mobile prey. Our
previous behavioral studies showed that A. boskianus did not differ from A.
scutellatus on a spatial task but that A. boskianus was significantly better at
the reversal of a visual discrimination, another task that is hippocampally
dependent in mammals. In the current study, we found that, relative to
telencephalon volume, the MC and DC were larger in the active forager whereas a
control region, the lateral, olfactory, cortex, was similar in size between
species. The current anatomical results suggest that MC and DC size is related to
active foraging in lizards and, along with our previous behavioral studies, show
that it is possible for this relationship to occur in the absence of evidence for
species differences in spatial memory.
PMID- 10681603
TI - A possible pathway connecting the photosensitive pineal eye to the swimming
central pattern generator in young Xenopus laevis tadpoles.
AB - The pineal eye of young Xenopus laevis tadpoles mediates a swimming response to
dimming. Our aim was to define pathways that allow pineal photoreceptors to
influence the swimming central pattern generator (CPG) in the hindbrain and
spinal cord. Retrograde filling with horseradish peroxidase (HRP) and
carboxyfluorescein showed that: (1) pineal ganglion cells do not project to the
hindbrain, and (2) diencephalic/mesencephalic descending (D/MD) neurons, which
could be contacted by pineal ganglion cell axons, do project to the hindbrain.
Lesion experiments demonstrated that ganglion cell axons form ipsilateral and
contralateral connections, either of which is sufficient to mediate a swimming
response. Latency measurements suggest that the contralateral pathway is stronger
than the ipsilateral one. Multiple unit recordings from the midbrain in the
region of the D/MD neurons showed short latency activity in response to dimming
or a brief current pulse to pineal axons. This activity could last for many
seconds after the stimulus. Pharmacological experiments showed that it depended
on synaptic excitation and suggested that the ganglion cell transmitter is
glutamate. If pineal ganglion cells excite midbrain D/MD neurons on both sides of
the brain, the D/MD neuron projections to the hindbrain could excite the swimming
CPG and initiate swimming.
PMID- 10681604
TI - Responses of single neurons in the toad's caudal ventral striatum to moving
visual stimuli and test of their efferent projection by extracellular antidromic
stimulation/recording techniques.
AB - Previous work in anuran amphibians has shown that activity in the caudal ventral
striatum correlates with visuomotor activity: orienting responses toward prey
fail to occur after striatal lesions. Thus it has been suggested that the
striatum influences visually guided behavior. Therefore, the present study
investigates visual response properties from neurons recorded in the striatum.
Extracellular recordings of 104 single neurons of the cane toad's (Bufo marinus)
caudal ventral striatum (STR) reveal five different response properties: resting
discharge activity uninfluenced by the visual test stimuli (group STR1, 24.0%);
resting discharge activity increased by any moving visual object (STR2, 31.7%);
preference to moving compact objects (STR3, 15.4%); preference to certain
configurational moving objects (STR4a and b, 13.5%), and resting activity reduced
by visual stimuli (STR5, 15.4%). The receptive fields of these neurons
encompassed the contralateral (46%) or the entire field of vision (54%). Of the
neurons recorded in the striatum, 34% responded to electrical stimuli applied in
the rostral diencephalon to the ipsilateral lateral forebrain bundle (LFB) which
connects the striatum with the optic tectum (e.g. either directly or via
pretectum or tegmentum). Various electrically driven STR neurons (40%) have axons
that project caudally through the LFB, which was suggested by their antidromic
activation in response to electrical stimuli applied to the LFB in the rostral
diencephalon. In the present study, the main striatal output is mediated by
'motion detectors' (STR2) and 'compact object perceivers' (STR3). It is suggested
that the caudal ventral striatum is involved in visual attentional processes that
allow the translation of perception into action.
PMID- 10681605
TI - Personal UV dosimetry by Bacillus subtilis spore films.
AB - BACKGROUND: Ultraviolet radiation (UVR) is known to be the most important risk
factor for melanoma and non-melanoma skin cancers. Until today it has been
impossible to measure reliably UVR in the frame of epidemiological studies. The
recent development of a spore film containing spores of Bacillus subtilis
resulted in a new method of UV measurement by personal dosimetry. METHODS: The
practical application of dosimeters was tested in 18 study persons under
different circumstances of UV exposure and in 4 different geographical regions.
RESULTS: Eleven children carried dosimeters on their shoulders for 1 day, playing
in- and outdoors on a sunny day in summertime. Their whole-day values ranged from
0.1 to 1.5 minimal erythema doses (MED) per day with a mean of 0.71 MED (+/
0.44). Four lifeguards in a public swimming-pool carried dosimeters on their
shoulders for 11 days and received UV exposures ranging from 3.6 to 9.5 MED (mean
5.9 +/- 1.88). Three mountain guides with dosimeters attached to the lateral head
in different mountain regions at 23 mountaineering activities received daily
exposures of 4.44-17.07 MED (mean 11.9 +/- 3.8). CONCLUSION: B. subtilis spore
film dosimeters can be applied to different study persons including children and
mountain guides under different climatic conditions. A broad range of UV
exposures can reliably be measured with this method.
PMID- 10681606
TI - Clinical, histological and immunopathological features of 58 patients with
subacute cutaneous lupus erythematosus. A review by the Italian group of
immunodermatology.
AB - BACKGROUND: Subacute cutaneous lupus erythematosus (SCLE) is a distinct subset of
cutaneous lupus erythematosus clinically characterized by psoriasiform and/or
annular lesions and by a mild or absent systemic involvement. OBJECTIVE: The
Italian Group of Immunodermatology of the Italian Society of Dermatology and
Venereology reviewed the cases of SCLE seen in 10 years (1987-1996). PATIENTS:
Forty-six women and 12 men have been retrospectively studied, 42% had annular
lesions, 39% psoriasiform ones and 16% both. RESULTS: Lesions were mainly
localized on the neck and face and relapsed in spring and autumn. Seventeen
patients had 4 or more American College of Rheumatology criteria and could be
classified as having systemic lupus erythematosus. The most frequent
histopathological alterations were epidermal atrophy, hydropic degeneration of
the basal layer and perivascular lymphocytic infiltrate. Deposits of
immunoglobulins and C3 at the dermo-epidermal junction on the clinically involved
skin were present in 86% of the patients. Dust-like particles in the epidermis
were only found in 3% of cases. Anti-Ro/SSA antibodies were found in 71% of the
cases and anti-dsDNA only in 5% of cases. CONCLUSIONS: SCLE is a particular
subset of cutaneous lupus erythematosus with peculiar clinical and
immunopathological features.
PMID- 10681607
TI - A cancer-registry-assisted evaluation of the accuracy of digital epiluminescence
microscopy associated with clinical examination of pigmented skin lesions.
AB - BACKGROUND: The accuracy of digital epiluminescence microscopy (D-ELM) as an
adjunct to clinical examination for the diagnosis of pigmented skin lesions
(PSLs) has seldom been evaluated. OBJECTIVE: To compare the accuracy of the
combined clinical/D-ELM (C/D-ELM) examination with that of the clinical
examination alone. METHODS: A total of 3,372 PSLs from 1,556 consecutive patients
referred to a skin cancer clinic underwent clinical examination and a combined
C/D-ELM examination. The reference diagnosis was established using the histology
report of known surgical excisions plus a cancer-registry-based follow-up
(duration 18 months) of benign C/D-ELM diagnoses. The two diagnostic approaches
were compared for sensitivity, predictive value and false-positive rate. RESULTS:
The series included 55 melanomas and 43 basal cell carcinomas. About 50% of
malignant misdiagnosed cases were identified solely through the cancer registry.
The C/D-ELM diagnosis showed a greater sensitivity for melanoma <0.76 mm thick
(83 vs. 46% for clinical examination alone; ratio, 1.82) and basal cell carcinoma
(79 vs. 49%; ratio, 1. 62), a greater predictive value for melanoma (81 vs. 53%;
ratio, 1. 53) and a reduced total false-positive rate (0.3 vs. 0.9%; ratio, 0.
31). CONCLUSION: D-ELM showed a potential to improve the clinical diagnosis of
PSL.
PMID- 10681608
TI - Calcipotriol cream combined with twice weekly broad-band UVB phototherapy: a
safe, effective and UVB-sparing antipsoriatric combination treatment. The
Canadian Calcipotriol and UVB Study Group.
AB - BACKGROUND: Calcipotriol has been combined with a number of systemic
antipsoriatric treatments, improving efficacy or reducing the systemic treatment
required. Although studies on calcipotriol and UVB have also been performed,
there are no data on the UVB-saving effect of calcipotriol combined with broad
band UVB to reduce overall UVB exposure, while maintaining efficacy. OBJECTIVES:
To assess the efficacy and safety of calcipotriol cream (50 microg/g) combined
with twice weekly broad-band UVB and to determine if this treatment would require
fewer UVB treatments and lower cumulative UVB irradiance when compared to a
standard 3 times weekly broad-band UVB regime in patients with extensive
psoriasis. METHODS: This multicentre, prospective, randomised, parallel-group,
vehicle-controlled, single-blind (investigator) study consisted of a 1-week wash
out phase, 12-week treatment phase and 12-week follow-up phase. Broad-band UVB
equipment was standardised and calibrated prior to the study. The UVB starting
dose was based on the patient's minimal erythema dose. Assessments included PASI,
extent, severity and investigator and patient's overall assessments of the
psoriasis. RESULTS: Fewer exposures (12 vs. 19) and less cumulative UVB
irradiance (1,570 vs. 5,430 mJ/cm(2)) were required by the calcipotriol + twice
weekly UVB group to achieve 80% reduction in PASI (p < 0.001). Similarly, fewer
exposures (22 vs. 25) and less cumulative UVB irradiance (4,147 vs. 9,670
mJ/cm(2)) were required by this group to achieve total clearance (p < 0.001).
There was no difference in the PASI, patient's and investigator's overall
assessments and number of adverse events recorded by either group for both the
treatment and follow-up phases. CONCLUSION: Calcipotriol cream + twice weekly
broad-band UVB phototherapy is an effective and safe antipsoriatric treatment,
resulting in fewer UVB exposures, lower cumulative irradiance and a saving of
time.
PMID- 10681609
TI - Efficacy of calcipotriol ointment applied under hydrocolloid occlusion in
psoriasis.
AB - BACKGROUND: Hydrocolloid (HCD) dressings enhance the efficacy of topical
corticosteroids. OBJECTIVE: We wanted to evaluate the effect of calcipotriol
ointment under an HCD dressing in the treatment of psoriatic plaques. METHODS: In
9 psoriatic patients, we cleared one plaque using this approach and took biopsies
at start, clearance and relapse. Clinical and immunohistochemical validation was
assessed. RESULTS: After an average treatment of 3.6 weeks, each lesion had
cleared (apart from some residual erythema). The average remission period was 8
weeks. During this treatment, the number of cycling epidermal cells (Ki-67
positive nuclei) and the expression of keratin 14 and keratin 16 had decreased
substantially. In biopsies taken from the skin immediately adjacent to the
relapsing lesion, these markers remained reduced which indicated the prolonged
effect of calcipotriol on epidermal differentiation. CONCLUSION: It is speculated
that combination therapy of calcipotriol with treatments with a different mode of
action such as photo(chemo)therapy, corticosteroids and cyclosporine might be
worthwhile.
PMID- 10681610
TI - Treatment and pain relief of ulcerative hemangiomas with a polyurethane film.
AB - BACKGROUND: Hemangiomas are the most common tumors occurring in young children.
The most common complication in the growing phase of hemangioma is ulceration.
AIM AND METHOD: We report healing, pain relief and evolutive effects of a
polyurethane film in 8 cases with ulcerative hemangiomas. RESULTS: In all 8
infants, prompt pain relief and healing within 1-2 months were observed. An
increased regression was also noted within 2-4 months, when the hemangiomas were
in the normal proliferative phase. CONCLUSION: As far as the authors know, there
is no explanation for the effectiveness of polyurethane film. Explanations could
be the occlusive effects of the film inhibiting proliferation or the decrease in
blood flow. As primary initial therapeutic approach in ulcerative hemangiomas, we
advocate the application of a polyurethane film. This therapy is painless and
suitable for children.
PMID- 10681611
TI - Clinical efficacy of narrow-band UVB (311 nm) combined with dithranol in
psoriasis. An open pilot study.
AB - BACKGROUND: For UVB, the most effective wavelength in clearing psoriatic lesions
was found to be of 313 nm. The efficacy of whole body exposure to narrow-band UVB
(311 nm) combined with dithranol in psoriasis has not been evaluated to date.
OBJECTIVE: Evaluation of the clinical efficacy of phototherapy with narrow-band
UVB (311 nm) and dithranol for psoriasis by means of whole body exposures and
analysis of the mean cumulative irradiation dose. METHODS: In this open pilot
study, 13 patients were treated for 4-5 weeks. Evaluation of the therapeutic
efficacy was performed by comparing the Psoriasis Area and Severity Index (PASI)
scores at baseline and after 4 weeks of treatment. The cumulative irradiation
dose was also calculated. RESULTS: Evaluation of the PASI scores showed a
significant overall reduction of psoriatic lesions after 4 weeks of treatment.
The cumulative irradiation dose was similar or lower to those found for
phototherapy with narrow-band UVB alone. DISCUSSION: In patients with widespread
psoriasis, treatment with narrow-band UVB (311 nm) combined with dithranol is
safe and effective, allowing reduction of the cumulative irradiation dose.
PMID- 10681612
TI - Paronychia with pyogenic granuloma in a child treated with indinavir: the
retinoid-mediated side effect theory revisited.
AB - BACKGROUND: The introduction of HIV-1 protease inhibitors into the treatment of
patients infected with HIV-1 has had a major influence on clinical practice.
However, the use of protease inhibitors is frequently associated with the
development of resistance and several side effects and interactions with other
drugs have been reported. OBSERVATIONS: We present the first pediatric patient
with paronychia with pyogenic granuloma associated with the administration of the
protease inhibitor indinavir. Clinical findings are discussed in view of a
possible interference of indinavir with endogenous retinoid metabolism.
CONCLUSION: Considerable evidence advocates the mediation of indinavir side
effects by impaired oxidative metabolism of retinoic acid through the inhibition
of cytochromes P450 3A by indinavir rather than by impaired formation of 9-cis
retinoic acid.
PMID- 10681613
TI - A prospective study of acute-onset steroid acne associated with administration of
intravenous corticosteroids.
AB - Steroid acne (SA) may occur after the administration of topical or systemic
corticosteroids. Because of several consultations of spinal injury patients with
a very abrupt onset of a uniform papular eruption (i.e. days) initially
misdiagnosed as a drug reaction or sepsis, we followed hospitalized patients who
received intravenous corticosteroids (IVC) for the development of acute-onset SA
in order to determine its incidence. Fifty-one consecutive subjects receiving IVC
were followed for the duration of their hospital stay and examined for the
development of acneiform lesions. Acute-onset SA occurred in 1 subject (2%).
Acute spinal cord injury may represent a high-risk clinical setting for acute
onset SA.
PMID- 10681614
TI - Leg ulcers in patients with myeloproliferative disorders: disease- or treatment
related?
AB - Leg ulcers are a relatively frequent problem in patients with myeloproliferative
disorders under treatment with hydroxyurea (HU). The pathogenesis is currently
unknown and may be multifactorial. Concomitant arterial or venous disease may
play a contributing role in the development of these wounds. Vasculitis,
cryoglobulinemia and pyoderma gangrenosum should be considered if typical
clinical signs are present. We report on 3 patients with myeloproliferative
disorders who developed HU-induced leg ulcers and review the literature. HU
induced leg ulcers share clinical features which can help to differentiate them
from leg ulcers of other etiologies: occurrence under long-term treatment with HU
at a dose of at least 1 g/day, localization in the malleolar region and
spontaneous healing when HU is discontinued. We conclude that differentiation
between disease-related and treatment-induced leg ulcers can be difficult and may
not always be possible. In HU-induced leg ulcers, cessation of the drug typically
leads to wound healing.
PMID- 10681615
TI - Kaposi's sarcoma after lung transplantation in a Sephardic Jewish woman.
AB - One of the four types of Kaposi's sarcoma (KS), KS after organ transplantation
under immunosuppression, is a well-known entity and has been abundantly described
in renal, heart and liver recipients. We report the second case of cutaneous KS
after lung transplantation, under regular immunosuppression, in a Sephardic
Jewish woman. This case, when added to the other 10 cases of posttransplantation
KS reported from Israel, all being Sephardic Jews, indicates that in Israel,
Sephardic Jews are at higher risk than Ashkenazi Jews to develop
posttransplantation KS. This observation should be added to the well-known
increased risk of Ashkenazi Jews to develop classic KS. Moreover, in Israel
Ashkenazi Jews develop classic KS at higher rates than Sephardic Jews. This
apparent discrepancy in the ethnic distribution between Sephardic and Ashkenazi
Jews in classic versus posttransplantation KS may shed light on the pathogenesis
of KS in general.
PMID- 10681616
TI - Interferon-alpha-associated development of bullous lesions in mycosis fungoides.
AB - We report a 67-year-old woman with mycosis fungoides (MF) who was receiving
subcutaneous injections of recombinant interferon alpha-2b (IFN-alpha). After 2
months of IFN-alpha treatment, bullous lesions appeared on her trunk and
extremities. A skin biopsy specimen from the trunk revealed histopathologic
features of bullous MF. Bullous lesions with specific infiltrates of MF are very
rare; to the best of our knowledge, this is the first case showing specific
bullous lesions of MF developed under IFN-alpha treatment.
PMID- 10681617
TI - Generalized granuloma annulare associated with granulomatous mycosis fungoides.
AB - We describe a 68-year-old man with plaque stage mycosis fungoides (MF) for 8
years. He developed tumorous lesions of granulomatous MF (GrMF) and generalized
granuloma annulare (GA) after a previously indolent clinical course. Since then,
the clinical course was aggressive with involvement of the bone marrow and lymph
nodes, and leukemic change occurred. Systemic chemotherapy was given, but the
patient died 9 months later due to neutropenic fever and septic shock. GA in
malignant lymphoma has been reported most frequently in association with
Hodgkin's disease. To the best of our knowledge, GA associated with GrMF has
never been reported in the English language literature. The prognostic
significance of the association of granulomatous inflammation and malignancy is
reviewed.
PMID- 10681618
TI - Pigmentation and pits at uncommon sites in a case with reticulate
acropigmentation of Kitamura.
AB - Reticulate acropigmentation of Kitamura is now reported from all over the world.
Additional features are being readily recognized. Our cases had pigmentation and
pits on the dorsa of the distal phalanges of the fingers and toes - the classical
features - as well as widely distributed pits on the palms, palmar aspect and
sides of the fingers. The involvement in our cases was more pronounced than in
the previously reported ones.
PMID- 10681619
TI - Tropical-wood-induced bullous erythema multiforme.
AB - We report a case of bullous erythema multiforme caused by an exotic wood, pao
ferro (Machaerium scleroxylon). A 25-year-old female, a luthier (guitar maker)
who often handles a variety of woods, developed bullous erythema multiforme. A
patch test confirmed a positive reaction to one of the exotic woods, pao ferro. A
subsequent accidental short contact with pao ferro 5 months following the first
incidence induced a similar exudative erythema. Exotic woods such as pao ferro
should be added to the list of contact allergens that can induce bullous erythema
multiforme.
PMID- 10681620
TI - Primary atrophic profound linear scleroderma. Report of three cases.
AB - We present 3 unusual cases of deep linear, primary atrophic scleroderma, not
preceded by inflammatory reaction and sclerosis, involving the subcutis and
deeper tissues. These cases differ in the course and prognosis from typical
profound scleroderma since they do not lead to disfiguration and crippling
deformities. In contrast to the atrophies left after regression of morphea or
linear scleroderma, they do not involve the dermis, which does not show
discoloration or changes in texture. Infiltrates in the endomysium, involvement
of deeper tissues and the progressive character of the disease argue for atypical
primary atrophic profound scleroderma. The coexistence in one case of primary
facial hemiatrophy appears to indicate also its relationship with primary linear
atrophies of the limbs.
PMID- 10681621
TI - Postirradiation morphea of the breast presentation of two cases and review of the
literature.
AB - The advent of radiation therapy as a common modality in the treatment and
palliation of breast cancer has led to the observation of morphea developing
months to years after supervoltage radiation therapy, in and around the site of
treatment. We report 2 new cases of morphea at the site of previous supervoltage
radiation therapy for breast cancer. The time period between irradiation and
onset of morphea in our 2 patients were an atypically long 6.5 years and 32
years, the latter being the longest reported such interval. With conservative
treatment, the inflammatory component of the lesions resolved over an
approximately 1-year period, leaving residual sclerosis. These patients are
compared to those previously reported in the medical literature so as to
summarize the range of clinical presentation and course. Recognition of
postirradiation morphea is important in distinguishing it from infectious
cellulitis, recurrent carcinoma, metastatic carcinoma or development of a second
primary carcinoma.
PMID- 10681622
TI - Recurrent intravascular papillary endothelial hyperplasia of the toes.
AB - We report on the rare case of a 50-year-old male with intravascular papillary
endothelial hyperplasia (IPEP) in the left toes. The patient noticed a small
tender mass in the left toes and underwent surgery in November 1997. The tumor
recurred twice after surgery. Histopathological examination revealed a pure form
of IPEP without underlying benign vascular lesions.
PMID- 10681623
TI - Three cases of type 2 segmental manifestation of multiple glomus tumors:
association with linear multiple trichilemmal cysts in a patient.
AB - We report 3 cases of congenital multiple glomus tumors seen during the last 5
years. One of them showed autosomal dominant inheritance with male-to-male
transmission. The remaining patients had no family history of similar lesions.
The clinical and histopathological aspects of our patients support the recently
described type 2 segmental manifestation of multiple glomus tumors. One of the
cases showed associated multiple and giant trichilemmal cysts with a linear
distribution in the scalp.
PMID- 10681624
TI - Humoral response in a patient with cutaneous nocardiosis.
AB - The clinical appearance of infection due to Nocardia spp. varies widely. The low
sensitivity of direct microscopy and the slow growth of the organism challenge
the laboratory diagnosis. We present the case of a skin abscess in an
immunocompetent man caused by Nocardia brasiliensis. Diagnosis was made by
cultivation and 16S rRNA sequencing. Using indirect immunofluorescence and
Western blot, a strong antibody response to the N. brasiliensis isolate could be
demonstrated. Serological tests might therefore be useful for the diagnosis and
management of nocardial infections.
PMID- 10681625
TI - UV transmission of summer clothing in Switzerland and Germany.
PMID- 10681626
TI - Macular amyloidosis due to friction by a horsehair glove.
PMID- 10681627
TI - Serum IgA autoantibodies in patients with epidermolysis bullosa acquisita: a high
frequency of detection.
PMID- 10681628
TI - Total anonychia congenita in a woman with normal intelligence: report of a
further case.
PMID- 10681629
TI - Pigmentary demarcation lines over the face.
PMID- 10681630
TI - Compression ulcer in a caisson worker.
PMID- 10681631
TI - Lack of detection of leukaemia inhibitory factor in the sera of psoriatic
patients.
PMID- 10681632
TI - Papular-purpuric 'Gloves-and-Socks' syndrome related to rubella virus infection.
PMID- 10681633
TI - Maternal hypothyroidism and child development. A review.
PMID- 10681634
TI - Insulin-like growth factor binding protein (IGFBP)-3-bound IGF-I and IGFBP-3
bound IGF-II in growth hormone deficiency.
AB - In blood, circulating IGFs are bound to six high-affinity IGFBPs, which modulate
IGF delivery to target cells. Serum IGFs and IGFBP-3, the main carrier of IGFs,
are upregulated by GH. The functional role of serum IGFBP-3-bound IGFs is not
well understood, but they constitute the main reservoir of IGFs in the
circulation. We have used an equation derived from the law of mass action to
estimate serum IGFBP-3-bound IGF-I and IGFBP-3-bound IGF-II, as well as serum
free IGF-I and free IGF-II, in 129 control children and adolescents (48 girls and
81 boys) and in 13 patients with GHD. Levels of serum total IGF-I, total IGF-II,
IGFBP-1, IGFBP-2 and IGFBP-3 were determined experimentally, while those of IGFBP
4, IGFBP-5 and IGFPB-6, as well as the 12 affinity constants of association of
the two IGFs with the six IGFBPs, were taken from published values. A correction
for in vivo proteolysis of serum IGFBP-3 was also considered. In controls, serum
total IGF-I, total IGF-II, IGFBP-3, IGFBP-3-bound IGF-I, IGFBP-3-bound IGF-II and
free IGF-I increased linearly with age, from less than 1 to 15 years, in the two
sexes. The concentrations of serum free IGF-I and free IGF-II were approximately
two orders of magnitude below published values, as well as below the affinity
constant of association of IGF-I with the type-1 IGF receptor. Therefore, it is
unlikely that these levels can interact with the receptor. In the 13 patients
with GHD, mean (+/- SD) SDS of serum IGFBP-3-bound IGF-I was -2.89 +/- 0.97. It
was significantly lower than serum total IGF-I, free IGF-I or IGFBP-3 SDSs (-2.35
+/- 0.83, -1.12 +/- 0.78 and -2.55 +/- 1.07, respectively, p = 0.0001). The mean
SDS of serum total IGF-II, IGFBP-3-bound IGF-II and free IGF-II were -1.25 +/-
0.68, -2.03 +/- 0.87 and 0.59 +/- 1.10, respectively, in GHD. In control
subjects, 89.8 +/- 4.47% of serum total IGF-I and 77.3 +/- 9.4% of serum total
IGF-II were bound to serum IGFBP-3. In patients with GHD, the mean serum IGFBP-3
bound IGF-I and IGFBP-3-bound IGF-II were 8.63 +/- 8. 53 and 19.1 +/- 14.7% below
the respective means of control subjects (p < 0.02). In conclusion, in GHD there
was a relative change in the distribution of serum IGFs among IGFBPs, due to the
combined effects of the decrease in both total IGF-I and IGFBP-3. As a result,
serum IGFBP-3-bound IGF-I and IGFBP-3 bound IGF-II, the main reservoirs of serum
IGFs, were severely affected. This suggests that the decrease in serum IGFPB-3
bound IGF-I and IGFBP-3-bound IGF-II might have a negative effect for growth
promotion and other biological effects of IGF-I and IGF-II. Finally, the
estimation of serum IGFBP-3-bound IGF-I, or the percentage of total IGF-I and IGF
II bound to IGFBP-3, might be useful markers in the diagnosis of GHD.
PMID- 10681635
TI - Growth hormone treatment downregulates serum leptin levels in children
independent of changes in body mass index.
AB - The changes in serum leptin levels during growth hormone (GH) treatment were
studied in 27 children, 17 with GH deficiency (GHD), 10 with idiopathic short
stature (ISS), and 9 with Prader-Willi syndrome (PWS). Within 1 month of GH
treatment, serum leptin levels decreased by 40% in the GHD children (p < 0.01).
There was no significant change in serum leptin level in the children with ISS.
In children with PWS, the mean serum leptin level decreased by almost 60% after 3
months of treatment (p < 0.001). Thereafter, no further decline was observed in
any of the 3 groups. Changes in body composition became evident first after the 3
months of treatment. In the GHD children, the BMI was unchanged while the mean
body fat percentage was 2.7% lower after 1 year of GH treatment (p < 0.05). In
the ISS children, neither BMI nor body fat percentage were significantly changed
during treatment. The PWS children exhibited a significant decrease in BMI after
6 months of GH treatment without any further change during the remaining period
of treatment. In this group, the mean body fat percentage decreased from 42 +/-
2.4 to 28 +/- 2.2% after treatment (p < 0.001). The finding that the fall in
leptin occurs before changes in body composition become detectable suggests a
direct effect of GH on leptin production, metabolism, or clearance.
PMID- 10681636
TI - Diagnosis of ACTH deficiency. Comparison of overnight metyrapone test to either
low-dose or high-dose ACTH test.
AB - Test sensitivity and accuracy of 250 microg/m(2) ACTH test, 1 microg/m(2) ACTH
test, and overnight metyrapone test were evaluated in 158 children at risk for
ACTH deficiency. Of 38 given high-dose ACTH, 20 had normal responses to
metyrapone and to high-dose ACTH. 14 had low response to metyrapone; of these
only 2 had low cortisol response (<550 nmol/l) to high-dose ACTH. Of 120 given
low-dose ACTH, 64 had normal responses to metyrapone and to low-dose ACTH. All 24
with low metyrapone response had low or borderline response to low-dose ACTH. The
remaining children had an inconclusive metyrapone response. In conclusion, high
dose ACTH misses most diagnoses of ACTH deficiency (21% sensitivity, 100%
specificity, 63% accuracy). In contrast, the low dose ACTH test accurately
diagnoses 90% of patients with ACTH deficiency (100% sensitivity, 68%
specificity). The low-dose ACTH test can serve as an accurate and practical
screening test for adequacy of ACTH reserve.
PMID- 10681637
TI - Final height, armspan, subischial leg length and body proportions in juvenile
chronic arthritis. A long-term follow-up study.
AB - OBJECTIVE: Assessment of growth disturbances in adults with a history of juvenile
chronic arthritis (JCA). MATERIAL AND METHODS: Sixty-five subjects, 52
premenopausal females and 13 males with a mean age (range) of 32.2 years (22.3
49.4) participated. Mean age at disease onset was 5.7 years (0.8-15.8) and mean
disease duration was 12.4 years (0.4-32). The follow-up time ranged from 18.7 to
46.9 years with a mean of 26.4 years. For each participant standard deviation
scores (z-scores) for final height, delta-height (the difference between observed
and expected height), armspan, subischial leg length and sitting height ratio,
were calculated. RESULTS: The study group as a whole did not exhibit linear
growth impairment. The categorical distribution of heights differed significantly
from a expected distribution in a healthy population (p < 0.001). A height z
score < -2 SD was present in 10.7% of the study group, of whom all had
polyarticular course of JCA. Polyarticular and systemic course of JCA (versus
pauciarticular) (p = 0.022), systemic steroid treatment (p = 0.006) and
Steinbrocker functional class II-IV (vs. I) in 1979 (p = 0.043) were variables
associated with reduced delta-height. In linear regression analyses, disease
severity defining variables were statistically significant predictors of reduced
final height and armspan. 27% of the study subjects had significantly reduced arm
span (p < 0.001). Subischial leg length and body proportions (sitting height
ratio) were normal. CONCLUSION: Our findings suggest that functionally impaired
polyarticular and systemic JCA patients treated with systemic steroids may be at
an increased risk of developing reduced final height and armspan. Disease control
achieved by an aggressive therapeutic approach, if possible with a minimal use of
systemic steroids, may reduce growth impairment in JCA.
PMID- 10681638
TI - Sera from children with type 1 diabetes mellitus react against a new group of
antigens composed of lysophospholipids.
AB - Several autoantibodies related to Type 1 diabetes mellitus and their
corresponding autoantigens have been previously identified. While peptide
antigens are more widely recognized, lipid antigens like sulfatides and
gangliosides are also known epitopes for the diabetic humoral immune response.
Islet cell antibodies (ICA) in Type 1 diabetes are heterogeneous immunoglobulins
directed against selected antigens in the islets of Langerhans. Moreover, ICA may
be the best predictive marker of disease in family members of patients with Type
1 diabetes. The aims of this study were: (1) to purify lipids from porcine
pancreas that contain ICA epitopes; (2) to characterize these lipid antigens, and
(3) to use the purified lipids in an assay to detect antibodies in patients with
Type 1 diabetes. A unique family of 4 lysophospholipids, 1 fully characterized as
lysophosphatidylmyoinositol, partially inhibited ICA staining, and therefore,
were considered to be candidate antigens for an ICA immunoassay. Using a dot blot
immunoassay, we detected antibodies directed against these phospholipids in 28
out of 46 (61%) diabetic sera, while detecting only 1 false positive out of 28
nondiabetic sera (3.6%; p < 0.0001 comparing diabetic vs. nondiabetic serum).
Therefore, lysophospholipid immunoassay positivity is present in sera of Type 1
diabetic patients. Furthermore, we detected 15 out of 23 ICA-negative diabetic
sera (65.2%), showing that our phospholipid immunoassay does not correlate with
ICA positivity.
PMID- 10681639
TI - Growth-suppressive effect of intra-articular glucocorticoids detected by
knemometry.
AB - After one intra-articular injection of 20 mg triamcinolone hexacetonide in the
knee, the length of the contralateral lower leg was found to be reduced in 2 boys
with juvenile rheumatoid arthritis.
PMID- 10681640
TI - Peritoneal carcinomatosis following laparoscopic resection of an adrenocortical
tumor causing primary hyperaldosteronism.
AB - A clinical syndrome combining hypertension and hypokalemic alkalosis led to the
diagnosis of primary hyperaldosteronism, caused by a right-sided, 2 cm large,
apparently benign aldosterone-producing adenoma. The adrenal tumor was completely
resected by laparoscopic adrenalectomy. Six months after surgery, the patient
exhibited a severe relapse of hyperaldosteronism. Extensive peritoneal metastases
of a mixed aldosterone- and cortisol-secreting adrenocortical carcinoma were
found at abdominal laparotomy. In the light of this case report, we discuss the
possibility that laparoscopic resection of adrenocortical tumors might contribute
to their subsequent peritoneal dissemination.
PMID- 10681641
TI - Acute watery diarrhea as the initial presenting feature of a pheochromocytoma in
an 84-year-old female patient.
AB - We report the case of an 84-year-old woman who was initially admitted to the
emergency room of our institution for frank dehydration caused by acute and
severe secretory diarrheas along with acidosis and hypokalemia. After extensive
gastrointestinal investigations, the etiology of the diarrhea remained unclear.
Because clinical symptoms and ionogram parameters worsened, despite intravenous
fluids and electrolyte replacement, an abdominal CT scan was performed and
unexpectedly revealed a 4.5-cm mass in the right adrenal gland. Several separate
24-hour urine catecholamines were shown to be highly elevated. The diagnosis of
pheochromocytoma was confirmed by MIBG scintigraphy and MRI. Before the
admission, the patient never experienced symptoms suggestive of pheochromocytoma,
except dry mouth and fear of impending death on several occasions. After 2 weeks,
the diarrhea stopped abruptly and spontaneously without specific medication but
after adequate rehydration. The patient subsequently underwent surgical removal
of the adrenal medullary mass. Postoperatively, urinary catecholamines returned
to normal values. Immunohistochemical study of the tumor confirmed the diagnosis
of pheochromocytoma and revealed the presence of VIP-positive cells organized as
islets in scattered areas of the tissue. This case illustrates the protean mode
of presentation of pheochromocytoma, as well as the ability of medullary neural
crest-derived cells to produce various neuropeptides potentially responsible for
a large variety of symptoms.
PMID- 10681642
TI - Mechanisms causing muscle proteolysis in uremia: the influence of insulin and
cytokines.
AB - Decreased muscle mass in patients with chronic renal failure (CRF) can be caused
by mechanisms that activate the ubiquitin-proteasome proteolytic system. This
system accelerates the degradation of muscle protein. Concurrent with muscle
protein breakdown, there is an increase in transcription of genes encoding
components of this pathway, including ubiquitin and subunits of the proteasome.
Potential activating signals include metabolic acidosis which stimulates
proteolysis in CRF patients and in muscle of rats with CRF by a mechanism
involving glucocorticoids. In CRF patients, there is insulin resistance and high
circulating levels of tumor necrosis factor and other cytokines. As the ubiquitin
proteasome proteolytic system is activated in acute diabetes and in catabolic
conditions associated with high levels of circulating cytokines, these factors
could also activate this pathway. Consequently, we examined whether the
transcription factor activated by certain cytokines, NF-kappaB, is involved in
the transcriptional regulation of subunits of the 26S proteasome complex. The
results suggest that cytokines may be involved in the regulation of muscle
protein degradation in uremia.
PMID- 10681643
TI - The balance between glucocorticoids and insulin regulates muscle proteolysis via
the ubiquitin-proteasome pathway.
AB - In uremia, accelerated muscle protein degradation results from activation of the
ATP-ubiquitin proteasome proteolytic pathway. Like uremia, other conditions
(e.g., acidosis and diabetes) activate this pathway in rat muscles and are
associated with excess glucocorticoids (GC) and impaired insulin action. To
define the stimuli responsible for muscle wasting in IDDM, the roles of
glucocorticoids, insulinopenia and acidosis in streptozotocin (STZ) - induced
diabetes were studied. Proteolysis in isolated epitrochlearis muscles from
acutely (3d) diabetic rats was 52% higher than pair-fed, sham-injected rats; this
increase was eliminated by an inhibitor of the proteasome or by blocking ATP
synthesis. In muscles of STZ-diabetic rats, the levels of ubiquitin-conjugated
proteins and mRNAs encoding ubiquitin, the ubiquitin-carrier protein, E2(14k) and
the C3, C5 and C9 proteasome subunits were increased. Transcription of ubiquitin
and C3 proteasome subunit genes in muscle was also increased by IDDM. Oral
NaHCO(3) eliminated acidemia but did not prevent accelerated muscle proteolysis.
Corticosterone excretion was higher in IDDM rats and adrenalectomy (ADX)
prevented these catabolic responses; physiologic doses of glucorcoticoids
restored the excessive protein catabolism in ADX-STZ rats. Giving IDDM rats
replacement insulin also normalized protein degradation in muscles. In
conclusion, reduced insulin together with physiologic levels of glucocorticoids
activate the ubiquitin-proteasome pathway by a mechanism that includes enhancing
ubiquitin conjugation and proteolysis by the proteasome. The balance between
these stimuli could regulate muscle proteolysis in uremia.
PMID- 10681644
TI - Glucocorticoids and acidification independently increase transcription of
branched-chain ketoacid dehydrogenase subunit genes.
AB - Metabolic acidosis and glucocorticoids act in concert to stimulate branched-chain
amino acid (BCAA) oxidation in adrenalectomized rats. In muscles of normal rats,
metabolic acidosis increases the maximal activity of the rate-limiting enzyme,
branched-chain alpha-ketoacid dehydrogenase (BCKAD) and a genetic response to
catabolic conditions like uremia is implicated by concurrently higher levels of
BCKAD subunit mRNA. To determine if acidification or glucocorticoids increase
transcription of BCKAD subunit genes, transfection studies were performed with
BCKAD promoter-luciferase reporter minigenes in LLC-PK(1) cells which do not
express gluco-corticoid receptors or LLC-PK(1) cells which express a rat
glucocorticoid receptor gene (LLC-PK(1)-GR101). Acidification significantly
increased luciferase activity in LLC-PK(1) cells and LLC-PK(1)-GR101 cells
transfected with reporter plasmids containing 7.0 kb of E2 subunit or 0.8 kb of
E1alpha subunit promoter region, respectively. Glucocorticoids in the form of
dexamethasone induced transcription of these minigenes but only in LLC-PK(1)
GR101 cells. Using promoter deletion analysis, independent transactivation
response elements to acidification or glucocorticoids were localized in the E2
promoter. In summary, catabolic responses to low extracellular pH and
glucocorticoids include enhanced expression of genes encoding BCKAD subunits.
PMID- 10681645
TI - Effects of acidosis on acute phase protein metabolism in liver cells.
AB - Metabolic acidosis has been shown to act as a causative factor in muscle protein
breakdown and negative nitrogen balance, as well as in decreased albumin
synthesis. Albumin and other acute phase proteins (APP) are mainly synthesized in
the liver following induction by interleukins, hormones and other mediators.
Acute phase proteins have been shown to be predictors of cardiovascular mortality
in the general population and in patients with end stage renal disease (ESRD).
Clinical investigation gives evidence that albumin is reduced by acidosis in ESRD
patients. The aim of our study was to investigate the role of the liver in
acidosis, i.e. the influence of acidosis on metabolic activity and secretion of
APP by liver cells (HepG2). Cells were cultured in a medium containing different
amounts of bicarbonate. Metabolic activity was significantly diminished when the
bicarbonate concentration of the extracellular medium was reduced (86.13+/-1.90%
(pH 7.0) vs. 99. 53+/-90% (pH 7.4); p<0.01). While cellular release of negative
APP was significantly decreased (albumin: 4.6+/-0.41 (pH 7.0) vs. 7.54+/-0.62 (pH
7.4) [ng/microg protein], p<0.001, transferrin: (0. 78+/-0.08 (pH 7.0) vs. 1.07+/
0.07 (pH 7.4) [ng/microg protein], p<0. 05), no significant influence of acidosis
(pH 7.0) on the positive APP, alpha(1)-acid glycoprotein (AGP) (1.69+/-0.25) (pH
7.0) vs. 1.62+/-0.23 (pH 7.4) [ng/microg protein]), could be shown. Our data
indicate that acidosis results in inhibition of liver cell metabolic activity and
in reduced secretion of the negative acute phase proteins albumin and
transferrin. In contrast, secretion of the positive acute phase protein AGP seems
to be unchanged at pH 7.0 as compared to pH 7.4. We conclude that negative and
positive APP in liver cells (HepG2) appear to be differently regulated by
acidosis.
PMID- 10681646
TI - Pathophysiologic glomerulotubular growth factor link.
AB - Circumstantial evidence from clinical and pathologic correlations in patients
with glomerular diseases and proteinuria suggest that glomerular protein
ultrafiltration contributes to tubulointerstitial injury. A series of studies was
performed to examine the hypothesis that in rats with adriamycin-induced
nephropathy or with diabetic nephropathy (but not in normal rats) high molecular
wt. growth factors are ultrafiltered into tubular fluid and act on tubular cells
through apical membrane receptors. Analysis of proximal tubular fluid that was
collected by nephron micropuncture indicates ultrafiltration of IGF-I, TGF-beta
and HGF. Respective receptors are also expressed in apical membranes in some
parts of the nephron as examined by immunohistochemistry. In vitro cell culture
experiments using proximal tubular fluid obtained from rats with experimental
glomerular diseases indicate that ultrafiltered IGF-I may contribute to increased
distal tubular Na-absorption. Indirect evidence also suggests that this growth
factor may increase the secretion of collagen types I and IV in proximal tubular
cells. TGF-beta and HGF cause increased expression and basolateral secretion of
MCP-1 in proximal tubular and collecting duct cells. There may be other biologic
effects on tubules that are caused by apical exposure to ultrafiltered growth
factors. These studies suggest that the glomerular ultrafiltration of bioactive
proteins causes or contributes to tubulo-interstitial pathology in glomerular
proteinuria.
PMID- 10681647
TI - Inflammation nutritional state and outcome in end stage renal disease.
AB - Hypoalbuminemia and reduction in lean body mass are potentially a reflection of
malnutrition and portend a poor prognosis in patients with end stage renal
disease (ESRD). The classic understanding of this relationship has been that ESRD
patients receive insufficient dialysis, reduce dietary intake and become
malnourished. Inflammation also causes many of the same changes in serum protein
composition and in body morphometry as malnutrition does even with adequate
calorie and protein intake. It has recently been recognized that this, the acute
phase response, occurs with frequency in ESRD patients and that both the physical
attributes of malnutrition and reduction in the serum concentration of albumin,
transferrin, prealbumin and apolipoprotein A-I all may lack a nutritional base.
The serum concentration of the acute phase proteins, C reactive protein (CRP) and
serum amyloid A (SAA), as well as the cytokines orchestrating the acute phase
response, predict albumin concentration as well as a number of clinically
important outcomes: specifically, erythropoietin resistance rejection of renal
transplant and survival. ESRD per se does not cause the acute phase response, and
indeed may blunt the response to infection. Activation of the acute phase
response may be a consequence of the interaction of mononuclear cells with
dialysis membranes, especially cuprophane, with endotoxin in dialysate, or
represents either clinically evident or obscure infection. Evaluation of the
acute phase response by measurement of CRP is advisable in the evaluation of
hypoalbuminemia or other stigmata of malnutrition in dialysis patients.
PMID- 10681648
TI - Genesis of atherosclerosis in uremic patients.
AB - Atherosclerosis significantly contributes to the high incidence of cardiovascular
complications and death of uremic patients. Whereas some of the mechanisms that
are being discussed in the atherogenesis of chronic renal failure are well
established, many others remain hypothetical at present. One of the main reasons
is that no long-term, well-controlled studies are available in this area which
would have systematically tested the importance of factors such as high blood
pressure, via the use of antihypertensive drugs, or disturbances of lipoprotein
metabolism, via the use of lipid-lowering medications. Current clinical practice
as to the use of the latter has been extensively reviewed in a recent meta
analysis by Massy et al. [69]. The majority of studies have been limited to
relating hemodynamic or metabolic parameters to parameters of ischemia.
Controlled long-term studies are required to reach valid conclusions on the
implications of the numerous factors which theoretically may play a role in the
atherosclerotic complications of chronic renal failure patients.
PMID- 10681649
TI - Apolipoprotein C-III, hypertriglyceridemia and triglyceride-rich lipoproteins in
uremia.
AB - Apolipoprotein C-III (ApoC-III) plays an important role in the metabolism of
triglyceride-rich lipoproteins and is known to be elevated in patients with
uremia. To investigate the role of apoC-III in uremic dyslipidemia, we examined
apoC-III, triglyceride levels and lipoprotein particles containing both apoB and
apoC-III (LP-Bc) in 27 uremic patients prior to dialysis (predialysis), 30
patients on hemodialysis (HD) and 31 patients on peritoneal dialysis (PD). All
three groups of patients had elevated levels of plasma apoC-III (20+/-7 mg/dl for
predialysis, 18+/-5 for HD and 22+/-8 for PD, compared to 11+/-3 mg/dl for
control subjects [p<0/01 for all comparisons]). ApoC-III was positively
correlated with plasma triglycerides in PD patients (r = 0.86, p<0.0001), HD
patients (r = 0.67, p<0.0001) and predialysis patients (r = 0.60, p<0.001) as
well as in all patients combined (r = 0.75, p<0.0001). ApoC-III was also
positively correlated with levels of LP-Bc in all three groups of patients,
although this correlation was less strong (r = 0.46, p<0.0001 for all patients
combined). In predialysis and PD patients, the majority of apoC-III was found in
heparin precipitable lipoproteins, whereas the majority of apoC-III in HD
patients was found in HDL, indicating less efficient lipolysis in predialysis and
PD patients in comparison with HD. These data support the hypothesis that the
elevation of apoC-III in uremia can alter the metabolism of triglyceride-rich
lipoproteins, leading to an elevation in triglycerides and LP-Bc. Understanding
the mechanism(s) of elevated apoC-III in uremia may help to clarify the causes of
uremic dyslipidemia.
PMID- 10681650
TI - Modification of lipoproteins in uremia: oxidation, glycation and carbamoylation.
AB - Lipoprotein modification occurs in uremic patients and in patients with end stage
kidney disease under chronic renal replacement therapy. Forms of lipoprotein
modification include lipid peroxidation, glycation, and carbamoylation. In this
short review, we discuss the presence of these forms of lipoprotein modification
and their association with various renal diseases. Methods to analyze lipoprotein
modification are introduced, and functional consequences related to vascular and
renal function are presented.
PMID- 10681651
TI - Molecular genetics of homocysteine metabolism.
AB - Recent genetic studies have led to the characterization of molecular determinants
contributing to the pathogenesis of hyperhomocysteinemia. In this article we
summarize the current insights into the molecular genetics of severe, moderate
and mild hyperhomocysteinemia. We will consider deficiencies of the trans
sulfuration enzyme cystathionine beta-synthase (gene symbol: CBS), and the
disturbances of the remethylation enzymes 5, 10-methylenetetrahydrofolate
reductase (gene symbol: MTHFR), methionine synthase (gene symbol: MTR), and the
recently identified methionine synthase reductase (gene symbol: MTRR).
Furthermore, we will focus on clinically important genetic polymorphisms which
are highly prevalent and thus of potential general interest.
PMID- 10681652
TI - Homocysteine and chronic renal failure.
AB - Homocysteine, a sulfur amino acid, is an important methionine derivative, which
has been implicated in the pathogenesis of atherothrombosis. Although only
observational, epidemiological studies are available at present, the evidence of
an association between hyperhomocysteinemia and increased cardiovascular risk is
quite strong and this is confirmed also in a population of chronic renal failure
patients. From a biochemical standpoint at least three mechanisms have been
summoned so far in order to explain homocysteine toxicity including: oxidation,
hypomethylation, and acylation. Proteins are believed to play a crucial role as
homocysteine molecular targets. Interference with the functions of several of
such macromolecules has been so far described being mediated by any of the above
mechanisms. Vitamins may positively influence homocysteine metabolism, thus
facilitating the metabolic clearance of this compound. Therefore they are
presently considered as potential means for reducing plasma levels of this amino
acid and preventing vascular occlusions in hyperhomocysteinemic patients. These
compounds, with special regard to folate, are eligible for interventional
clinical trials, from which the definitive answer on the role of homocysteine in
atherothrombosis is expected.
PMID- 10681653
TI - Pathophysiology and clinical importance of hyperhomocysteinemia: clinical
intervention studies.
AB - Hyperhomocysteinemia is a cardiovascular disease risk factor in the general
population and in patients with renal failure. This article summarizes the
results of recent total homocysteine-lowering intervention studies in individuals
without renal failure and in patients with renal failure. Although almost all of
the published studies mainly focused on the total homocysteine-lowering effect
and not on cardiovascular disease outcomes of folic acid and vitamin therapy,
recent work has gained important insights into this area of developing concern.
PMID- 10681654
TI - Regulation of appetite in chronic renal failure.
AB - Anorexia, nausea and vomiting in patients with severe renal failure may cause or
contribute to development of protein-energy malnutrition, which is associated
with increased morbidity and mortality. However, the specific mechanisms that
cause appetite suppression in uremia are poorly understood. This review
summarizes the general mechanisms by which appetite is regulated. Various factors
are discussed that may potentially be involved in appetite suppression in chronic
renal failure.
PMID- 10681655
TI - Leptin and its clinical implications in chronic renal failure.
AB - Leptin, the recently identified ob gene product, regulates food intake and energy
expenditure in animal models. Leptin reaches the brain by a saturable transport
mechanism and, via direct effects on the hypothalamus, decreases appetite and
increases metabolism. Several recent studies have demonstrated markedly elevated
serum leptin levels in patients with chronic renal failure (CRF) and it has been
speculated that hyperleptinemia may contribute to uremic anorexia and
malnutrition. Several factors may influence serum leptin levels in uremia and
apart from decreased glomerular filtration rate also body fat mass and plasma
insulin levels are important factors that determine serum leptin levels. The
possible influence of chronic inflammation on serum leptin levels in CRF need
further studies. Patients treated by peritoneal dialysis seem to have higher
leptin levels compared to patients treated by hemodialysis. This could be the
effect of a marked increase in body fat mass as a consequence of the continuous
carbohydrate load. Leptin receptors have by now been identified in several
peripheral organs which suggests that leptin besides having central effects also
has a pleiotropic action. Indeed, recent findings indicate that besides
regulating appetite leptin may play a role in sympathico-activation, insulin
metabolism, renal sodium handling and hematopoiesis.
PMID- 10681656
TI - Effects of neuropeptide Y on appetite.
AB - Neuropeptide Y (NPY) is a polypeptide containing 36 amino acids. Circulating NPY
originates predominantly from the sympatho-adrenomedullary nervous system. It has
a vasoconstrictive and mitogenic effect on blood vessels and seems to be involved
in blood pressure regulation and angiogenesis. NPY is a potent orexigenic agent
and is presumed to play a leading role in the regulation of eating behavior.
Stimulation of the NPY-ergic arcuate - paraventricular nucleus (ARC-PVN) pathway
by exercise, fasting, energy loss (glucosuria) is followed by increased appetite
and food intake and increased parasympathetic activity, but suppression of
sympathetic activity and energy expenditure. The end result of this process is an
increase of energy stores. Activity of the NPY-ergic ARC-PVN pathway is
suppressed by leptin - a polypeptide produced by adipocytes. Although functioning
of an NPY-leptin feedback was found in rodents, it seems likely that also in man
the NPY-leptin axis is involved in the regulation of food intake and energy
expenditure.
PMID- 10681657
TI - High protein/energy vs. standard protein/energy nutritional regimen in the
treatment of malnourished hemodialysis patients.
AB - Although malnutrition is frequently encountered in maintenance hemodialysis (MHD)
patients, a clear method of treating this complication is still lacking. Failure
of nutritional support regimens may be due to inadequate support of dietary
needs. Therefore, a high vs. standard or low protein/energy dietary regimen was
studied in malnourished MHD patients. A total of 18 malnourished MHD patients
selected according to subjective global assessment (SGA)-scores and biochemical
indicators of malnutrition (serum albumin <40 g/l, cholesterol <200 mg/dl,
prealbumin <30 mg/dl; two out of three) were assigned to three treatment groups:
(A: 45 kcal/kg/d and 1.5 g protein/kg/d; B: 35 kcal/kg/d and 1.2 g protein/kg/d;
C: spontaneous intake supplemented with 10% of mean protein and energy intake). A
and B received food supplements at appropriate dosing to reach the targeted
nutritional intake. During 3-month follow-up nutrient intake was assessed by
repeated 4-day dietary diaries. Compliance and tolerance was good in each group.
Weight gain (1.2+/-0.4 kg) was observed in group A, but not in B and C. Serum
albumin levels increased by 1.0+/-0.5 g/l in group A, but not in B and C.
Prealbumin and cholesterol levels were unaffected. Weight change correlated with
mean dietary energy intake, but not with mean dietary protein intake. We conclude
that prescription of 45 kcal/kg/d and 1.5 g protein/kg/d may be necessary to
achieve weight gain and improvement of nutritional indices in malnourished MHD
pts. Oral food supplements can be used safely and effectively to increase
nutrient intake to high levels in these patients.
PMID- 10681658
TI - Low protein diets are not needed in chronic renal failure.
AB - Low protein diets have been used for a long time in the conservative management
of chronic renal failure as they have a beneficial effect in preventing the
appearance of symptoms. However, with the exception of the beneficial effect on
hyperphosphatemia of the very low protein diets supplemented with ketoacids, they
have no proven effects on the other aspects of the uremic syndrome. Moreover, the
weight of the evidence suggests that the effect of these diets on preservation of
GFR, if any, in patients with nondiabetic renal disease is small and of little
clinical relevance. There is very little evidence in the literature of its role
in patients with diabetes. The nutritional safety of these diets is still
suspect. Patients with chronic renal failure have low energy intakes, which is
further reduced when these diets are prescribed. Metabolic studies predict that
these patients would be in negative nitrogen balance and in fact, even
nutritionally sound, nondiabetic patients enrolled in the Modification of Diet in
Renal Disease Study developed subclinical signs of malnutrition. It is possible
that the nutritional decline may have been more pronounced on longer duration of
follow-up. Finally, these diets are difficult to follow, leading to issues of
compliance and exert a great toll on the time of the dietitians. Hence, we
conclude that low protein diets are not necessary in chronic renal failure.
PMID- 10681659
TI - The potential of intradialytic parenteral nutrition: A review.
AB - Malnutrition is common in chronic hemodialysis (CHD) patients and is strongly
related to increased morbidity and mortality. Among the various approaches to
treat malnutrition in this patient population, intradialytic parenteral nutrition
(IDPN) is the treatment of choice for a small but important percentage of
malnourished CHD patients. However, the new revised policies relating to IDPN
reimbursement by Medicare in the US have made it very difficult to qualify
patients for this potentially useful therapy. This restrictive policy was adopted
mainly because there are no clear data that support IDPN use or efficacy. Studies
to date in the literature do not provide clear documentation of the benefits of
IDPN or their cost-effectiveness. The purpose of this review is to critically
evaluate studies relating to the use of IDPN as a potential therapy to treat
malnutrition in CHD patients and to discuss potential trials to prove its cost
effectiveness.
PMID- 10681660
TI - Intradialytic parenteral nutrition in malnourished hemodialysis patients. Review
of the literature.
AB - Malnutrition is a frequent problem of patients on intermittent hemodialysis and
is associated with increased morbidity and mortality. Intradialytic parenteral
nutrition (IDPN), i.e. intravenous supplementation of mixtures of glucose, amino
acids and/or lipids during the hemodialysis session, is one of the therapeutic
measures that are applied to correct this malnutrition. To our knowledge only few
long-term clinical studies have been undertaken, evaluating the effect of
intravenous calorie administration in hemodialysis. Most studies were carried out
over a relatively short observation period in small study populations; in several
of these studies, no measures were taken to prevent losses of nutrients in the
dialysate; adequate control groups are often missing. The authors review the
current available literature and conclude that IDPN might have a significant
beneficial effect on the nutritional status in malnourished hemodialysis
populations.
PMID- 10681661
TI - Nutrition impact of peritoneal dialysis solutions.
AB - All peritoneal dialysis (PD) solutions are designed to remove toxins and water,
normalize the blood electrolyte profile, and provide alkali to help maintain acid
base balance. Different formulations, however, may have different effects upon
nutrition status. Solutions with 40, as opposed to 35, mEq/l of sodium lactate
have been found to promote weight and muscle mass gain and reduce hospitalization
in malnourished PD patients. Glucose is varied to produce solutions with
different ultrafiltration potential. The glucose absorbed from the PD solution
has a protein-sparing effect. The high glucose concentrations necessary for
sustained ultrafiltration over a long dialysis dwell, however, often produce
appetite suppression and metabolic abnormalities. Solutions formulated with
glucose polymers, instead of hypertonic glucose, may provide sustained
ultrafiltration over long dwells with lower carbohydrate absorption and perhaps
fewer metabolic effects. Amino acids can also be substituted for glucose at
relatively low concentrations. A number of studies have shown that amino acids
absorbed from the dialysis solution can provide nutritional benefit to
malnourished PD patients.
PMID- 10681662
TI - Vitamin D analogs: perspectives for treatment.
AB - Vitamin D therapy is widely used for the treatment of secondary
hyperparathyroidism associated with chronic renal failure. However,
administration of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] or its precursor
1alpha(OH)D(3), especially in combination with calcium-based phosphate binders,
often produces hypercalcemia. Several vitamin D analogs have been developed that
retain the direct suppressive action of 1,25(OH)(2)D(3) on the parathyroid glands
but have less calcemic activity. These analogs offer a safer and more effective
means of controlling secondary hyperparathyroidism. 22-Oxa-1,25(OH)(2)D(3) (22
oxacalcitriol or OCT), 19-nor-1, 25(OH)(2)D(2) (19-norD(2)) and 1alpha(OH)D(2)
have been tested in animal models of uremia and in clinical trials. Intravenous
19-norD(2) and oral 1alpha(OH)D(2) have been approved for use in the United
States; OCT is currently under review. The mechanisms by which these analogs
exert their selective actions on the parathyroid glands are under investigation.
The low calcemic activity of OCT has been attributed to its rapid clearance which
prevents sustained effects on intestinal calcium absorption and bone resorption,
but still allows a prolonged suppression of PTH gene expression. The selectivity
of 19-norD(2) and 1alpha(OH)D(2) is achieved by a distinct mechanism(s).
Knowledge of how these compounds exert their selective actions on the parathyroid
glands may allow the design of more effective analogs in the future.
PMID- 10681663
TI - Transcriptional and post-transcriptional regulation of PTH gene expression by
vitamin D, calcium and phosphate.
AB - 1,25(OH)(2)D(3) the biologically active metabolite of vitamin D is synthesized in
the renal proximal tubules from the hepatic metabolite 25 (OH)D. Lack of
1,25(OH)(2)D(3) is relevant to the pathogenesis of secondary hyperparathyroidism,
and 1,25(OH)(2)D(3) itself is used effectively in the management of renal failure
patients to prevent secondary hyperparathyroidism. The scientific basis of this
therapy is the finding that 1,25(OH)(2)D(3) potently decreases PTH gene
transcription both in vitro and in vivo.
PMID- 10681664
TI - Nonclassical effects of 1alpha,25-dihydroxyvitamin D(3) and its analogs.
AB - The activated form of vitamin D(3), 1alpha,25(OH)(2)D(3), not only plays a
central role in bone and calcium metabolism but has also potent antiproliferative
and prodifferentiating effects. Moreover, the combined presence of 25(OH)D(3)
1alpha-hydroxylase as well as the vitamin D receptor in several tissues
introduced the idea of a paracrine role for 1alpha,25(OH)(2)D(3). By introducing
chemical modifications into the flexible parent molecule 1alpha,25(OH)(2)D(3), a
whole generation of vitamin D analogs was created. Due to a clear dissociation of
the antiproliferative and prodifferentiating effects from calcemic effects, these
analogs can be used not only for the treatment of bone disorders but also for non
classical applications.
PMID- 10681665
TI - Vitamin replacement therapy in renal failure patients.
AB - Renal failure patients require vitamin replacement therapy that addresses the
specialized needs of renal failure. Four factors including restricted diet,
uremic toxins, drug-nutrient interactions, and in ESRD, the dialysis process,
affect the normal absorption, retention and activity of necessary micronutrients
which support all aspects of carbohydrate, protein, lipid and nucleic acid
metabolism. Studies have shown that the typical renal failure diet is low in B
vitamins, that uremic factors affect folate and pyridoxine activities and that
many B vitamins are lost on dialysis at a rate greater than are lost with normal
urinary excretion. In addition, retention of vitamin A or inappropriately high
supplementation of vitamin C may cause toxicities which exacerbate existing
pathologies. Further, emerging research suggests some vitamins such as folic acid
and pyridoxine, if provided in higher than normal amounts, may have an impact on
reducing the risk of some aspects of renal cardiovascular disease. It is
therefore important to supplement some vitamins, and use restraint in the
supplementation of others. It is clear that renal failure patients, including
predialysis, ESRD and transplant patients need specialized supplementation that
meets the requirements of disease and its management.
PMID- 10681666
TI - Influence of water and sodium diuresis and furosemide on urinary excretion of
vitamin B(6), oxalic acid and vitamin C in chronic renal failure.
AB - Urinary excretion of vitamin B(6), oxalic acid and vitamin C was investigated in
15 healthy subjects during maximal water diuresis and in the group of 12 patients
in polyuric stage of chronic renal failure without dialysis treatment receiving a
diet containing high sodium chloride (15g/day). Urinary excretions of the same
parameters were investigated in another group of 15 patients in polyuric stage of
chronic renal failure without dialysis treatment after i.v. administration of 20
mg furosemide. Urinary excretion of vitamin B(6), oxalic acid and vitamin C
significantly increased during maximal water diuresis while during high intake of
sodium chloride the urinary excretions of these substances were not affected. The
results suggest that urinary excretion of vitamin B(6), oxalic acid and vitamin C
depends on the urinary excretion of water. Intravenous administration of 20 mg
furosemide led to an increase of urinary excretion of vitamin B(6), oxalic acid
and vitamin C in patients with chronic renal failure. The increased urinary
excretion of vitamin B(6) and vitamin C is a new negative side effect of
furosemide and increased urinary excretion of oxalic acid is a new positive side
effect in patients with chronic renal failure.
PMID- 10681667
TI - Metabolic adjuvants to erythropoietin therapy.
AB - It is possible to potentiate the response to epoietin by co-administering other
agents. In some instances, this response is seen when there is a deficiency of a
certain substance. In other cases, administration of an adjuvant such as
intravenous iron, vitamin D, L-carnitine, or androgens can enhance the response
to epoietin when given as a surfeit. With most of these agents, with perhaps the
exception of intravenous iron, further research is required to determine the
exact role they may play in clinical practice. As long as the cost of epoietin
therapy remains fairly high, the challenge will continue as to the best way of
optimizing its effect, and we can look forward to new developments in this
expanding area of research.
PMID- 10681668
TI - Preventive effects of an oral sorbent on nephropathy in rats.
AB - Circulating uremic substances are thought to be involved in the progression of
chronic renal failure (CRF). An oral adsorbent AST-120 (Kremezin) is effective in
removing circulating uremic toxins from the gastrointestinal tract, and retards
the progression of CRF. AST-120 is widely used as an approved drug in Japan for
the treatment of undialyzed uremic patients to delay the progression of CRF. AST
120 attenuates the progression of glomerular sclerosis and interstitial fibrosis
in a variety of experimental rat models of CRF. However, the mechanism by which
AST-120 delays the progression of CRF had not been clear. We have demonstrated
that indoxyl sulfate, a dietary protein metabolite, is a circulating uremic toxin
stimulating glomerular sclerosis and interstitial fibrosis, and that AST-120
decreases the serum and urine levels of indoxyl sulfate by adsorbing its
precursor, indole, in the intestine. The administration of indoxyl sulfate to
uremic rats stimulated the expression of transforming growth factor (TGF)-beta1,
tissue inhibitor of metalloproteinase (TIMP)-1 and pro-alpha1(I)collagen in the
kidneys. Further, the administration of AST-120 to uremic rats reduced the extent
of glomerular sclerosis and interstitial fibrosis as well as the renal expression
of TGF-beta1 and TIMP-1, by reducing the serum and urine levels of indoxyl
sulfate. We propose the protein metabolite hypothesis that endogenous protein
metabolites such as indoxyl sulfate play an important role in the progression of
CRF, and that AST-120 is effective in retarding the progression of CRF by
removing these protein metabolites through intestinal absorption.
PMID- 10681669
TI - Liver cell reactive components in peritoneal dialysis fluids.
AB - Metabolic changes in peritoneal dialysis (PD) patients are an important aspect
concerning long-term outcome. Liver plays the main role in regulating metabolism.
The effects of peritoneal dialysis fluids (PDF) on liver cell function are
scarcely investigated. Therefore, we investigated the effects of PDF, different
in some components, on liver cell metabolism in vitro. Metabolic activity (MTT),
cell integrity (LDH release), proliferation (BrdU incorporation) and synthesis of
albumin and transferrin are measured by incubating HepG2 cells for 3 h and 24 h
with six different PDFs: (a) lactate-buffered, pH5.5: PDF I (1.5% gluc.); PDF II
(4.5% gluc. ); (b) bicarbonate-buffered, pH7.4: PDF III (1.5% gluc.), PDF IV (4.
5% gluc.); (c) amino acid-based solutions, pH 7.4: PDF V (low AA level) and PDF
VI (high AA level). Metabolic activity of bicarbonate-treated cells is greatly
enhanced in comparison to lactate-buffered PDFs. These findings are confirmed by
proliferation data. Synthesis of albumin and transferrin is significantly
enhanced by amino acid-based solutions. Our data demonstrate, that lactate
buffered PDF impair liver cells much stronger than bicarbonate-buffered PDF. pH
is the parameter which contributes to cytotoxicity and impaired metabolism to a
major extent. In contrast to glucose-containing solutions, amino acid-based PDF
stimulate protein synthesis in liver cells.
PMID- 10681670
TI - Advanced glycation end-product levels in subtotally nephrectomized rats:
beneficial effects of angiotensin II receptor 1 antagonist losartan.
AB - The angiotensin II receptor 1 antagonist losartan (L) inhibited the advanced
glycated end-products (AGEs) induced expression of transforming growth factor
beta(1) in in vitro experiments performed on renal tubuloepithelial cells. To
test the pathophysiological importance of these findings, the possible link
between serum AGEs levels and angiotensin system was investigated in the model of
normotensive subtotally nephrectomized rats(4/6-NX). Concentration of AGEs in
serum of placebo administered 4/6-NX rats (n = 7, 1.09+/-0.09 U/l) increased
slightly in comparison with sham-operated healthy controls (CTRL, n = 8, 0.94+/
0.10 U/l, p<0.02) as measured by competitive ELISA. Treatment of 4/6-NX rats with
L over 12 weeks ameliorated the rise in serum AGEs concentration (1.00+/-0.12
U/l, n = 15 <0.005) almost to the level observed for CTRL. This effect was
further corroborated by the observation, that the impaired renal excretion of
AGEs in 4/6-NX-placebo rats (0.07+/-0.02 U/micromol creatinine) was significantly
restored by L (0.09+/-0.02 U/micromol creatinine, <0.009) and resembled that of
the CTRL (0.10+/-0.03 U/micromol creatinine). Administration of L to 4/6-NX rats
significantly improved renal function as evaluated by a smaller rise in serum
creatinine and urea concentration. In spite of the improvement in renal function,
there were no differences in concentrations of transforming growth factor beta(1)
in serum and in urine among the two groups. These effects were independent of
blood pressure. Our data give first evidence, that long-term treatment with
angiotensin II receptor 1 antagonist may exert salutary effects on AGEs levels in
the rat remnant kidney model, probably due to improved renal function.
PMID- 10681671
TI - Nitric oxide/L-arginine in uremia.
AB - Nitric oxide (NO), a gaseous free radical derived from L-arginine, is a potent
modulator of vascular tone and platelet functions. A number of recent studies,
both in the experimental model of renal mass reduction (RMR) in rats and in
uremic patients, have raised the hypothesis that abnormalities of NO synthetic
pathway could have a key role in mediating the complex hemodynamic and hemostatic
disorders associated to the progression of renal disease. Thus, kidneys from rats
with RMR produce less NO than normal rats and NO generation negatively correlates
with markers of renal damage. The abnormality is due to a strong defect of
inducible NO synthase (iNOS) content in the kidney. Recent in vitro and in vivo
data have raised the possibility that excessive renal synthesis of the potent
vasoconstrictor and promitogenic peptide endothelin-1 (ET-1) is a major
determinant for progressive iNOS loss in the kidney of RMR rats. In contrast,
uremia is associated with excessive systemic NO release, both in experimental
model and in human beings. In the systemic circulation of uremic rats, as well as
uremic patients, NO is formed in excessive amounts. Possible cause of the
increased NO levels is higher release from systemic vessels due to the augmented
expression of both iNOS and endothelial NOS. A putative cause for excessive NO
production in uremia can be guanidinosuccinate, an uremic toxin that accumulates
in the circulation of uremic patients and upregulates NO synthesis from cultured
endothelial cells. Upregulation of systemic NO synthesis might be a defense
mechanism against hypertension of uremia. On the other hand, more NO available to
circulating cells may sustain the bleeding tendency, a well-known complication of
uremia.
PMID- 10681672
TI - Long, slow dialysis.
AB - Long slow hemodialysis (3 x 8 hours/week) has been used in Tassin for 30 years
without significant change in the method. It provides excellent results in terms
of morbidity and mortality. The better survival than usually reported on shorter
dialysis is mainly due to lower cardiovascular mortality. The nutritional state
of the patient is good, as well as the correction of anemia with low doses of
EPO. But the main feature concerns blood pressure; hypertension is very well
controlled without need for antihypertensive medications. The gentle
ultrafiltration provided by a long session time associated with a low salt diet
and a moderate interdialytic weight gain allows for normalization of the
extracellular fluid space in most patients (dry weight) without important
intradialytic morbidity. This low salt diet has paradoxically been forgotten in
recent years while shortened dialysis time renders it more necessary than ever.
PMID- 10681673
TI - Nutritional status assessment and body composition analysis in pre-end stage
renal disease patients.
AB - Malnutrition is a known risk factor for survival in renal failure patients. Of
concern, a significant degree of malnutrition may develop in the predialysis
period due to dietary restrictions and uremia. To further define this issue, we
evaluated 25 predialysis patients using serum chemistries, body mass index (BMI),
fat free mass (FFM), body cell mass (BCM), and protein appearance rate (PAR) as
surrogates of nutritional status and compared their results to those obtained in
established hemodialysis patients and recipients of living donor renal allografts
during a nine-month observation period. Pre- dialysis patients had significantly
(p<0.0001) higher body weight (28%), body mass index (26%), body cell mass (17%)
and fat free mass (15%) than hemodialysis and transplant patients. Intracellular
water content was similar in all groups. As many patients do not start dialysis
until clearance values fall below 10 ml/min, it is possible that greater tissue
mass losses occur in the weeks preceding initiation of dialytic therapy. Why
renal transplant recipients fail to increase tissue mass may relate to the
catabolic effects of immunosuppression. We conclude that the early stages of pre
end stage renal disease are associated with relatively good preservation of body
cell mass.
PMID- 10681674
TI - Bioelectrical impedance analysis in dialysis patients.
AB - Identification of malnutrition is imperative in chronic dialysis patients.
Bioelectrical impedance (BIA) is a noninvasive method to measure body composition
and estimate total body water (TBW), lean body mass (LBM) and body cell mass
(BCM). Studies suggest BIA has good reliability as compared to other accepted
methods of body composition analysis. Preliminary data also suggest that BIA
derived parameters (reactance and phase angle) predict clinical outcome in
chronic hemodialysis patients. Overall, BIA is a promising nutritional assessment
tool to monitor health status, long-term follow-up, tailor nutrition support, and
detect early subtle losses of LBM in chronic dialysis patients.
PMID- 10681675
TI - Cranial bone fixation in infants and children.
AB - A technique is described for fixing cranial bone flaps with absorbable sutures
and bone shims. This technique is a cost-efficient method of rapidly achieving
rigid structural stability with excellent cosmetic results. The kerf created by
the craniotome is bridged at multiple sites by bone chips harvested from the
inner edge of the bone flap. Solid bony union is documented on histopathological
analysis. The technique requires no special tools and avoids the problems
associated with the use of plates, screws and wire.
PMID- 10681676
TI - Experiences with cranial neuronavigation in pediatric neurosurgery.
AB - Frameless, infrared-based neuronavigation (Surgical Microscope Navigator and
Surgical Tool Navigator) was applied to intracranial neurosurgery in 22 children
and infants (age range 7 months to 16 years). Predominant diagnoses were tumor
and hydrocephalus (including multiloculated forms); the surgical procedures were
open microneurosurgery in 10 cases and neuroendoscopy in 12 patients. There were
no principal technical problems even in very young infants. Surgical and clinical
results were satisfying in all cases. Neuronavigation proved to be particularly
helpful in targeting deep-seated processes and in guiding neuroendoscopy in cases
of multiloculated hydrocephalus or small ventricles.
PMID- 10681677
TI - Endoscopic approach to noncommunicating fluid spaces in the shunted patient.
AB - INTRODUCTION: It is well known that shunted hydrocephalic patients can, over
time, develop entrapped ventricles or cystic spaces not in communication with the
remaining ventricles. This situation has traditionally been treated with
placement of an additional catheter or shunt system in the noncommunicating fluid
space. With the advent of minimally invasive endoscopic techniques, it has become
possible to fenestrate trapped fluid spaces into the shunted ventricular system,
thus preventing the need for additional catheters. METHODS: Fifteen shunted
patients presented with noncommunicating fluid spaces over a 4-year period at our
two institutions. We attempted fenestration procedures in 14 of those patients.
The various procedures included: septum pellucidum fenestration, cyst
fenestration, third ventriculocisternostomy and a combination of the above.
RESULTS: Thirteen of 16 (81%) endoscopic fenestrations successfully prevented the
need for a complicated shunting system. There were 3 technical failures (3/16,
19%) in which an additional catheter was added to the existing shunt system at
the time of the endoscopic procedure. There were no adverse neurologic effects
from the endoscopic procedures; however, in 4 of the 14 patients (29%) a shunt
revision was performed between 2 and 30 days following the fenestration.
CONCLUSIONS: These results show that the endoscopic approach to establishing
communication between noncommunicating CSF spaces in the shunted patient is safe
and efficacious in preventing the need for additional CSF catheters. Though we
encountered failures, the majority of cases are technically feasible. In these
patients early shunt malfunction may occur, most likely due to intraoperative
bleeding and will require shunt revision.
PMID- 10681678
TI - Thalamic glioblastoma with cerebrospinal fluid dissemination in the peritoneal
cavity.
AB - Glioblastoma multiforme is one of the commonest primary malignant tumours of the
brain with rare incidence of extracranial metastases. Systemic dissemination via
the CSF or CSF diversionary shunt procedures is also rare. The reported 9-year
old child was a case of thalamic glioblastoma with hydrocephalus who underwent
biventriculoperitoneal shunting before tumour decompression and radiotherapy. The
child developed incapacitating ascites 8 months following surgical decompression
and 9 months after the shunt diversion which was found to be caused by CSF
dissemination of the glioblastoma via the ventriculoperitoneal shunt. The child
ultimately succumbed to his disease.
PMID- 10681679
TI - Successful use of intracavitary bleomycin for low-grade astrocytoma tumor cyst.
AB - We report successful use of bleomycin in a low-grade astrocytoma tumor cyst of
the tectal plate. A 6-year-old male underwent subtotal resection of a low-grade
astrocytoma of the tectal plate followed by chemotherapy and proton beam
radiation at age 2 and a half. Despite resolution of the solid portion of the
tumor, serial MRI showed enlargement of a bilobar tumor cyst 3 years after the
original diagnosis. The patient developed progressive ataxia, short-term memory
loss and dysconjugate gaze. Following stereotactic placement of an Ommaya
reservoir into the cyst, Isovue contrast and CT scan were used to confirm the
integrity of the cyst. Five consecutive daily doses of 3.0 mg of bleomycin were
instilled into the cyst after removal of cyst fluid. The therapy was well
tolerated in the outpatient setting, and the clinical findings resolved.
Subsequent CT and MRI at 4 months and 2 years after bleomycin confirmed no
recurrence of the tumor or cyst.
PMID- 10681680
TI - Inflicted traumatic brain injury: relationship of developmental outcome to
severity of injury.
AB - Inflicted traumatic brain injury (TBI) is a frequent consequence of physical
child abuse in infants and children. Twenty-eight children who were 2-42 months
of age when hospitalized for moderate to severe TBI were enrolled in a
prospective, longitudinal study of neurobehavioral outcome following acquired
brain injury. Relative to a comparison group, the children with inflicted TBI had
significant deficits in cognitive, motor and behavioral domains when assessed
with the Bayley Scales of Infant Development-II 1 and 3 months after the injury.
Nearly half of the injured children showed persisting deficits in
attention/arousal, emotional regulation and motor coordination. Greater injury
severity, as indicated by lower coma scale scores, longer periods of
unconsciousness and the presence of edema/cerebral infarctions was associated
with poorer outcomes in all domains.
PMID- 10681681
TI - Skull base growth in childhood.
AB - While studying skull base changes in craniosynostosis, it became apparent that
there is a lack of reference studies quantifying the changes of three-dimensional
(3D) parameters of the normal skull base throughout childhood. Using advanced 3D
visualisation techniques, 34 points of the skull base were identified on MRI
scans of 66 normal children, aged 1 month to 15 years. Several distances and
angles between the various landmarks were measured in an attempt to quantify the
growth of skull fossae with age. Two main growth periods were observed: before
and after the first 5 years of life. Most change occurred in the first period.
Anatomical regional differences were identified between the two sexes. During the
first 5 years of life, the anterior fossa showed rapid growth rate with respect
to its anterior projection in males, whereas in the females there was a more
concentric growth pattern. The body of the sphenoid bone and the middle fossa
showed a rapid growth rate in both sexes which was greater in the females. The
posterior fossa showed a concentric pattern of growth in both sexes with a
greater growth rate in the females. These findings provide new insight into the
pattern of growth of the various parts of the skull base and can be used for
comparative study of deformities that affect such growth.
PMID- 10681682
TI - Late shunt infections.
AB - We reviewed the records of the 957 shunt-related operations performed at Cardinal
Glennon Children's Hospital over a 10-year period. During that time, 94 shunt
infections were recognized. Eight of the infections occurred more than 9 months
postoperatively. These differed from early infections in two ways: (1)
Staphylococcus aureus was not found to be a pathogen in any late infection. (2)
Abdominal pseudocysts were much more frequently found in patients with late
developing infections. In addition, the pathogens involved and the temporal
distribution of cases suggest most infections that occur more than 9 months
postoperatively are more likely caused by secondary bacterial seeding than by
bacterial inoculation at the time of operation.
PMID- 10681683
TI - Abdominal pseudocysts complicating CSF shunting in infants and children. Report
of 18 cases.
AB - Abdominal pseudocysts (APC) are rare complications of ventriculoperitoneal
shunting for hydrocephalus. The authors studied retrospectively a series of 18
pediatric patients with APC. Signs and symptoms of shunt dysfunction were
observed in 15 (83.3%), abdominal complaints in 10 (55.5%) and fever in 6
(33.3%). Prior to the diagnosis of APC, 2 patients suffered exploratory
laparotomies due to important abdominal signs and symptoms. Ultrasonography was
diagnostic in all cases and proved to be the method of choice in the evaluation
of APC. Our series suggest that APC are strongly related to hardware infection
and in some cases can result from a previous shunt infection not completely
cured. The bacteriological examination of the tip of the peritoneal catheter was
a reliable indicator of infection. According to our data, the best treatment
seems to be the removal of the shunt system and the insertion of an external
ventricular drainage. In our experience, almost half of the patients had a
ventriculoatrial shunt replacing the peritoneal shunt at the end of the
treatment.
PMID- 10681684
TI - Vein of galen malformation.
PMID- 10681685
TI - Radiologic and histopathologic changes after Gamma Knife radiosurgery for
acoustic schwannoma.
AB - Gamma knife radiosurgery (GKRS) is a widely used treatment option for acoustic
schwannomas, 3 cm in diameter or less. Between May 1990 and February 1998, 102
acoustic tumors in 101 patients were treated with GKRS. There are 77 patients
with a follow-up period of more than six months (mean 55, range 7 to 90 months).
Seventy (91%) of these tumors have remained unchanged or reduced in volume. After
GKRS there was an increase in volume in seven cases. In four the volume increase
affected solid tumour. Among these, three patients were in stable condition and
are being observed. One of these patients developed brain stem compression
symptoms and was operated. In another three cases, cysts with multiple septa
developed medial to the tumor and compressed the brain stem and fourth ventricle,
thus necessitating post-GKRS surgery. In these three patients, MRI had shown loss
of central contrast enhancement followed by its return. Histological findings at
surgery before and after GKRS were compared for these four tumours. In spite of
the MRI changes, there were no definite histological findings after GKRS which
could be attributed to radiation induced changes. The development of cysts
occurred after the treatment of larger tumors.
PMID- 10681686
TI - Gamma Knife radiosurgery relative to microsurgery: epilepsy.
AB - There is a strong rationale for investigation of the role of Gamma Knife
radiosurgery in the treatment of medically intractable epilepsy. To explore this
potential application, the well established and highly successful current
outcomes associated with microsurgical treatment were reviewed, and include for
temporal resections seizure-free results in 65-70% of patients, with permanent
morbidity of less than 5% and mortality less than 1%. Advantages of open surgery
include the opportunity to conduct electrocorticography and functional mapping,
excellent visualization enabling an assured and discrete line of resection,
freedom in general from volume constraints, and immediate efficacy. The
preliminary evidence in support of radiosurgical treatment includes several
series of patients with epilepsy associated with arteriovenous malformation,
tumor, or cavernous anginoma in which results approaching those of surgery have
been achieved. In a series of 15 patients with mesial temporal sclerosis, all but
one patient with follow-up of at least one year are seizure-free; morbidity has
been limited to one asymptomatic field defect. A series of ten patients with
epilepsy associated with hypothalamic hamartoma has achieved seizure improvement
in six of eight patients with at least one year follow-up, and no major morbidity
has been seen. Radiosurgical treatment for intractable epilepsy appears to be
effective in a majority of patients and can be performed safely and efficiently.
Early experimental evidence suggests that seizure control might in some instances
be achievable without ablation of the pathological target.
PMID- 10681687
TI - Gamma Knife radiosurgery for epilepsy associated with cavernous hemangiomas: a
retrospective study of 49 cases.
AB - A retrospective multicenter study was performed to evaluate the effectiveness of
Gamma Knife radiosurgery (GKRS) in the treatment of drug resistant epilepsy
associated with cavernous hemangiomas (CH). The mean duration of epilepsy before
GKRS was 7.5 ? 9.3 years. The mean frequency of seizures was 6.9 ? 14/month. The
mean marginal dose was 19.2 ? 4.4 Gy (range 11.3 to 36 Gy). The mean follow up
was 23.7 ? 13 months. At the most recent follow-up examination, 26 (53%) patients
were seizure-free (Engel s class I) including 24 in class IA (49%) and two (4%)
patients with occasional auras (class IB, 4%). A highly significant decrease in
the number of seizures was achieved in 10 (20%) patients, which is class lIB. The
remaining 13 (2.6%) patients showed little or no improvement. A medial temporal
location was associated with a higher risk of failure. In contrast, all patients
with central region CH were seizure free. Two severe but transient complications
were observed. There was hemorrhage in one patient and another patient suffered
from radio-induced edema with transient aphasia. This series is the first
demonstrating that GKRS can be used safely and efficiently to treat epilepsy
associated to CH. Seizure control can be reached when a good electro-clinical
correlation exists between CH location and epileptogenic zone. Our findings
suggest that GKRS can be used to treat epilepsy for CH located in highly
functional areas, particularly the central region.
PMID- 10681688
TI - The effects of stereotactic radiosurgery on secondary facial pain.
AB - Twenty-seven patients with tumor-related secondary facial pain were treated by
stereotactic radiosurgical procedures between November 1991 and October 1998.
They had 14 meningiomas, 11 schwannomas (one trigeminal, 10 vestibular), one
nasopharyngeal cancer and one chordoma. The mean maximum dose administered was
26.4 Gy (range 16 to 35 Gy) and the margin of the tumor was encompassed within
the 45 to 90% isodose. The patients were analyzed based on their pain relief with
a mean follow-up duration of 32.1 months. In 24 patients (85.7%), there was
initial pain improvement after radiosurgery, but half had recurrent pain. A pain
response was obtained in 12 cases (pain response rate = 42.9%), five were pain
free and seven had pain reduction. On the follow-up MRI, a decrease in tumor
volume of more than 20% of the preoperative volume occurred in 14 of 25 cases.
The mean time interval to initial pain improvement (10.3 months) and pain
response (5.7 months) were shorter than for a decrease in tumor volume (18.6
months). Tumor-related secondary facial pain was less responsive to stereotactic
radiosurgery than idiopathic trigeminal neuralgia. It would seem that the
mechanism of pain relief in radiosurgery is not only trigeminal root
decompression secondary to tumor volume reduction, but also other mechanisms
involving inactivation of abnormal electrical transmission may be involved.
PMID- 10681689
TI - Brain tumors with cysts treated with Gamma Knife radiosurgery: is microsurgery
indicated?
AB - Cysts, which are not uncommonly associated with brain tumors, may be responsible
for neurological dysfunction. Stereotactic aspiration of such lesions can lead to
clinical improvement, but cyst recurrence is common and multiple aspirations may
be necessary. Thirteen cases of brain tumors with cystic components were treated
by radiosurgery with follow-up of 5-29 months (median 14 months). The tumor
diagnoses were three cystic craniopharyngiomas, two brain stem cystic
astrocytomas, two cystic cerebellar astrocytomas, one cerebellar
hemangioblastoma, one ganglioglioma, one fourth ventricle tumor, one
cerebellopontine angle pilocytic astrocytoma, one metastasis from lung cancer and
one glioblastoma. The dose at the tumor margin ranged between 10 and 20.5 Gy
(mean 15.5 Gy) and the maximum dose ranged between 18 and 45 Gy (mean 32.3 Gy).
In 11 of these cases the cystic component recurred in spite of a decrease in the
size of the solid tumor component. An Ommaya reservoir was inserted in six cases,
stereotactic aspiration was performed in two cases, microsurgery was undertaken
in two cases after 2-8 months (mean 4.8 months) and one patient refused further
treatment. Multiple aspirations through the Ommaya reservoir were performed in
the outpatients on the two patients who required them. It may be appropriate to
be cautious in advising radiosurgery for intracranial tumors with a significant
cystic component. Microsurgery if possible may be preferable in this situation.
PMID- 10681690
TI - Paradoxical labeling of radiosurgically treated quiescent tumors with Ki67, a
marker of cellular proliferation.
AB - Ki67 (also known as MIB) is a monoclonal antibody staining agent, which is
routinely used as a marker of cellular proliferation. It is used to evaluate the
proliferative potential of malignant tumors, since it is thought to stain only
those cells undergoing active division. The paradoxical elevation of the Ki67
labeling index observed in radiosurgically treated benign and malignant tumors is
reported. Ten patients, who had previously undergone either linac or Gamma Knife
radiosurgery, underwent surgical resection for a radiographically quiescent
tumor. One patient underwent autopsy after dying from complications of
radiosurgery. All were thought to be suffering from adverse radiation effect
(ARE) and were refractory to conservative management. None were thought to have a
recurrent tumor. All of the resected tumors were subjected to analysis with Ki67
staining. Despite the radiographic stability of the tumors, all manifested
significantly elevated populations of cells exhibiting positivity for Ki67
antigen. This staining pattern would suggest a significant proliferative
potential, which did not match the observed clinical course. The literature is
reviewed and possible mechanisms to explain the paradoxical findings are
presented.
PMID- 10681691
TI - Radiosurgery of glomus tumors: midterm results.
AB - Glomus tumors (GT) of the skull-base present a complex surgical challenge due to
their delicate localization and specific vascular supply. This study is designed
to evaluate the role of stereotactic radiosurgery in the treatment of GT.
Thirteen patients with GT have been treated with the Gamma Knife. Radiosurgery
was performed because of recurrences after surgical removal in six patients.
Histology was not available in seven patients, thus, diagnosis was made from
neuroradiological features only. Two of them had partial embolization before
Gamma Knife treatment. Clinical and morphological data were collected from 11
patients, who had a representative follow-up of at least 12 months. Mean follow
up was 42 months (range 14 to 72 months). Within the follow-up period there was
no tumor progression and no clinical deterioration in any of the patients. 64% of
the patients had an improvement of their symptoms, and in 36% the volume of the
lesion decreased in size. There was no radiation-related morbidity. It is
suggested that radiosurgery seems to be safe and effective in the treatment of
GT.
PMID- 10681692
TI - A comparison of single fraction radiosurgery tumor control and toxicity in the
treatment of basal and nonbasal meningiomas.
AB - Between July 1993 and October 1997, 107 patients with 118 meningiomas were
treated with Gamma Knife radiosurgery (GKRS). The most frequent site of tumor
origin was the skull base (54%). The mean tumor diameter and volume were 2.5 cm
and 9.4 cm3, respectively. The mean dose to the tumor periphery was 17 Gy,
prescribed to a mean iso-dose of 47%. At a mean follow-up of 28 months, tumor
control for basal and nonbasal meningiomas was 80%. Deteriorating peritumoral
edema associated with symptoms was observed in 1 of 49 (2%) skull-base tumors and
in 4 of 39 (10%) non-basal tumors, without associated tumor growth. (p=0.l5 and
0.234 respectively, z-test). Stereotactic radiosurgery can achieve acceptable
tumor control with low morbidity in the treatment of most meningiomas. However,
when the tumor is nonbasal, the potential morbidity from peritumoral edema should
be recognized and other treatment options considered, such as adjuvant surgery,
partial fractionated irradiation or stereotactic radiotherapy.
PMID- 10681693
TI - Low-dose radiosurgery for meningiomas.
AB - Gamma Knife radiosurgery is an effective treatment for meningiomas. However, it
may be difficult to deliver what is currently considered an optimal dose,
especially if the tumor is large or adjacent to critical structures. Eleven cases
are presented with a follow-up of more than 12 months where the margin dose did
not exceed 10 Gy. The mean age was 48.8 years. The mean follow-up period was 35.7
months (range 21 to 57 months). The mean volume of the tumors was 9.4 cm3 (range
1.6 to 28.9 cm3). The margin dose was less than 10 Gy in all 11 cases, due to a
large volume in two cases. Four tumors were close to the visual pathways. Five
tumors were close to the brain stem. Imaging follow-up showed that four tumors
had shrunk after radiosurgery. The remaining seven cases remained unchanged.
There was no tumor growth after radiosurgery. A transient oculomotor palsy was
observed in two cases after radiosurgery. It is suggested that Gamma Knife
radiosurgery using lower dosage than usual is one of the options for the
treatment of meningioma.
PMID- 10681694
TI - Gamma Knife radiosurgery for metastatic brain tumor: the usefulness of repeated
Gamma Knife radiosurgery for recurrent cases.
AB - Forty-one patients with a total of 193 metastatic brain tumors were treated
because of new lesions or in a few cases because of tumor regrowth. The
management involved two to four treatments with Gamma Knife radiosurgery (GKRS).
The overall median survival was 15 months. The local control rate of tumors was
89% for the first treatment and 93% for repeated treatments. Symptomatic
radiation-induced edema appeared in only two cases (4.9%). Patients with
metastatic brain tumors who developed new lesions after GKRS were treated with
GKRS alone for subsequent lesions. It was possible to control tumors for a long
period with minimal side effects. As a result, we were able to maintain the
quality of life of these patients, but, the effect of GKRS in controlling tumor
regrowth seemed temporary.
PMID- 10681695
TI - Gamma Knife radiosurgery for skull base metastasis and invasion.
AB - We treated 18 patients with skull base metastasis or invasion using Gamma Knife
radiosurgery. Seven of these patients had invasive nasopharyngeal cancer and 11
had distant metastasis from other cancers. The mean diameter of tumors was 22-46
mm (median 32.1 mm) and the radiation dose to the tumor margin was 12-23 Gy
(median 16.2 Gy). The median follow-up period was 10.5 months. Clinical symptoms
were improved in 61% of the patients after treatment and tumor control was
obtained in 67% of cases at their final followup. Radiation injury occurred in
only one patient (6%) who had received previous radiotherapy to the same region.
Gamma Knife radiosurgery is a useful therapeutic option for the treatment of
skull base metastasis and invasion, either as a secondary treatment for
recurrence after previous radiotherapy or as a primary treatment.
PMID- 10681696
TI - A six year experience with the postoperative radiosurgical management of
pituitary adenomas.
AB - Since April 1992, 73 consecutive patients with pituitary adenomas were treated
with radiosurgery. There were 31 hormonally inactive adenomas and 42 hormonally
active adenomas. All but three patients had been subjected to one or more
surgical procedures prior to radiosurgery. Three patients had received
fractionated radiotherapy. In the inactive adenoma group, the mean target volume
was 4.4 ? 3 cm3 and the mean prescription dose was 13.8?1.5 Gy. In the
prolactinoma patients, the mean target volume was 6.7 ? 9 cm3 and the mean
prescription dose was 14.2 ?4 Gy. In the acromegalic patients, the mean target
volume was 2.9?2.5 cm3 and the mean prescription dose was 16?4 Gy. ACTH secreting
adenomas had a mean target volume of 3.6 ? 5.5 cm3 with a mean prescription dose
of 17 ?4.8 Gy. The mean follow-up time was 28.9 ? 21.5 months. Follow-up data was
available in 83.6% of the patients. Tumor control was achieved in 98.3% and the
endocrinological cure rate was 57%. Pituitary function deteriorated in 19.2%. No
patient suffered from radiation induced visual damage. It would seem that
postoperative radiosurgery for residual or recurrent pituitary adenomas may be a
safe technique that can increase the frequency of therapeutic success.
PMID- 10681697
TI - Gamma Knife radiosurgery for functioning pituitary adenomas.
AB - Stereotactic radiosurgery has been an important treatment modality in the
treatment of pituitary adenomas. However, it has the disadvantage of a delayed
effect on hormonal normalization compared with microsurgical resection of
functioning pituitary adenomas. To define the efficacy of radiosurgery in the
treatment of functioning pituitary adenomas, 37 cases with a mean follow-up
duration of 26.9 months were analyzed. There were 18 prolactinomas, 11 cases with
acromegaly, and 8 cases with Cushing s disease. The mean maximum dose was 54.8
Gy. The tumor margin was encompassed within the 50 to 90% isodose. The level of
serum prolactin, growth hormone, and 24-hour urine free cortisol were evaluated
for hormonal follow-up according to the relevant endocrinopathy. There was 35.1%
hormonal normalization and an 81.8% decline in hormone levels to below 50% of the
preoperative value (hormonal response). Hormonal normalization was obtained in 13
patients (mean latency = 22 months). A hormonal response was seen in 30 patients
(mean latency = 7.6 months). The maximum dose and tumor volume included in the
prescription isodose were significantly correlated with the latency period from
radiosurgery to hormonal normalization. These results suggest that early hormonal
normalization can best be achieved by a high maximum dose (at least 55 Gy) and
broad coverage of the target tumor volume within the prescription dose thereby
increasing the integral dose.
PMID- 10681698
TI - Gamma Knife radiosurgery for pituitary adenomas.
AB - Ninety-two patients with pituitary adenomas have been treated during the last 5
years. Sixty-three of these patients had more than 6 months follow-up, and they
form the basis of this report. Eighteen had non-functioning adenomas (NFA), and
36 had functioning adenomas (FA). The mean marginal dose was 22.5 Gy (NFA 19.5
Gy, FA 23.9 Gy). Control of tumor growth was achieved in 92%. A significant
decrease of excessive hormone production was seen in 75.6%, and the
endocrinopathy normalization rate was 26.7%. Post-radiosurgical complications
were seen in 4.7%.
PMID- 10681699
TI - Gamma Knife radiosurgery for functioning pituitary microadenoma.
AB - Transsphenoidal microsurgery remains the treatment of choice for pituitary
microadenomas One hundred and six patients were treated with Gamma Knife
radiosurgery (GKRS) for pituitary adenomas, and of these, 23 patients (1 male, 22
female) had microadenomas. Twenty-two of these patients were followed up and
endocrinological tests were available for 15 of these 22. Thirteen of these 15
had prolactinomas, while the remaining 2 had acromegaly. The follow-up period was
from 3 to 26 months (median 12 months). The mean age was 33.6 years (range 21 to
60 years). The mean maximum tumor dose was 35.7 Gy and the mean margin dose was
22 Gy. Serum prolactin (PRL) was normalized in three patients, decreased in eight
and unchanged in two. The growth hormone (GH) secretion in the acromegalic
patients has remained unchanged through the follow-up period. Thus, GKRS is a
valuable adjuvant to transsphenoidal microsurgery for patients with pituitary
microadenomas.
PMID- 10681700
TI - Pituitary adenomas treated by microsurgery with or without Gamma Knife surgery:
experience in 122 cases.
AB - The clinical outcome of 122 patients with pituitary adenomas treated by
microsurgery and/or Gamma Knife radiosurgery (GKRS) was analyzed to evaluate
patient selection criteria and the role of GKRS. Sixty-six resections were
performed in 59 patients. All tumors were macroadenomas, except for 5 ACTH
producing adenomas. Twenty-four of the 31 hypersecreting adenomas showed normal
serum hormone values after treatment. Postoperative complications were
rhinorrhea, cranial nerve palsies, and a small thalamic infarct. GKRS was
performed on 18 of the operated patients because of residual tumors, mostly in
the cavernous sinus. Thirty-five of the 63 patients treated by GKRS were followed
for more than 2 years. All adenomas except 2 were stable or had decreased in
size. Eleven of 17 functioning adenomas showed normal serum hormone values after
treatment. It is concluded that tumors that compress the optic pathway should be
removed and that residual tumors in the cavernous sinus are good indications for
radiosurgery.
PMID- 10681701
TI - Cerebral infarction with ICA occlusion after Gamma Knife radiosurgery for
pituitary adenoma: A case report.
AB - Cranial irradiation may lead to accelerated atherosclerotic changes to small or
medium sized arteries, but stroke associated with pituitary irradiation is not
frequent. A patient treated with Gamma Knife radio-surgery (GKRS) for a pituitary
adenoma suffered a cerebral infarction with internal carotid artery occlusion 4
years after radiosurgery. The patient was a 35-year-old male presenting with a
visual disturbance. Endocrinological tests were normal. MRI revealed a 4.3 by 4.3
cm diameter invasive macroadenoma of the pituitary, projecting toward the
suprasellar region and with cavernous sinus involvement with encasement of both
internal carotid arteries (ICAs). GKRS was performed for residual tumor after a
transcranial resection. The maximum dose was 40 Gy and the dose to the right
carotid artery was below 20 Gy. The delayed hemiparesis was accompanied by a
right capsular lacunar infarct shown on MRI. The images also showed a marked
reduction in tumor size. Total, right ICA occlusion was confirmed by Doppler
ultrasound. The patient had no history or signs of heart disease or metabolic
disorder which could predispose to cerebrovascular
PMID- 10681702
TI - Craniopharyngiomas: A six year experience with Gamma Knife radiosurgery.
AB - The focused radiation produced by radiosurgery offers the theoretical advantage
of a reduced radiation dose to surrounding structures during the treatment of
residual craniopharyngiomas when compared with fractionated radiotherapy. A
retrospective analysis of 23 patients treated since 1992 was undertaken.
Intracystic bleomycin treatment in 10 patients with cystic tumors proved to be
effective in preparing the tumors for radiosurgery. The mean prescription dose in
this series was 10.8 ? 8.7 Gy delivered to a mean prescription 47% isodose. There
was a volume reduction of the residual tumor in 74%. In this series, initial
tumor volume and target volume were significant prognostic factors. Smaller
tumors and targets were more likely to shrink. Five patients with large
multicystic residual or recurrent tumors after multiple surgical attempts showed
further progression. The maximum radiation dose, prescription dose and choice of
prescription isodose were not significant prognostic factors within this series.
Radiosurgery resulted in no mortality and no significant morbidity could be
attributed to it. Clinically, the best results with radiosurgery were obtained
with monocystic tumors amenable to stereotactic drainage and intracystic
bleomycin treatment.
PMID- 10681703
TI - TLD measurements of the relative output factors for the Leksell Gamma Knife.
AB - The accuracy of the output factor directly affects the accuracy of dose delivery
during patient treatment. At our Gamma Knife center, annual output factor
measurements have been carried out by using a high accuracy TLD technique,
characterized by the group annealing and sorting (GAS) procedure. For each
collimator exposure, one to five LiF Thermoluminescent Dosimeter (TLD) 1 x 1 x 1
mm3 cubes were used, depending upon the collimator size, and the process was
repeated until approximately 10 TLDs had been exposed for each collimator.
Transit radiation dose accumulated during the motion of the treatment couch was
measured for each collimator helmet, and the result was subtracted from the
uncorrected TLD dose measurements. The mean values of the output factors for the
14, 8 and 4 mm collimators from last 5 years were 0.985 ? 0.001, 0.948 ? 0.005
and 0.833 ? 0.007, respectively, relative to the 18 mm collimator. These measured
relative output factors are virtually identical to the values recommended by the
manufacturer for the 14 mm and 8 mm collimators. On the other hand, the output
factor for the 4 mm collimator was approximately 4.1% larger than that
recommended by the manufacturer. The significance of these findings is discussed.
PMID- 10681704
TI - Successful conversion from a linear accelerator-based program to a Gamma Knife
radiosurgery program: the Cleveland Clinic experience.
AB - From August 1989 to January 1997, 307 treatments in 293 patients were performed
with a linear accelerator-based (LINAC) stereotactic radiosurgery system. Because
of the program s success, the need for a dedicated radiosurgery unit in Ohio and
the desire to treat functional disorders, the Cleveland Clinic Health System
(CCHS) obtained the first Gamma Knife in the state of Ohio. Based on the previous
volume of patients for radiosurgery, it was estimated that 75-100 patients would
be treated during the first year of operation. However, during the first calendar
year, 214 treatments were performed on 205 patients, which far exceeded
expectations. The success of the CCHS Gamma Knife Center can be attributed to an
increase in a number of factors. These included marketing efforts, patient
awareness, increased use for functional disorders, physician understanding of
radiosurgery, use by qualified nonaffiliated radiation oncologists and
neurosurgeons, and outpatient delivery (95% with the Gamma Knife vs <5% with the
LINAC). With proper planning, education, and awareness, the opening of a Gamma
Knife Center can greatly increase the volume of radiosurgery performed when
compared with a LINAC-based program.
PMID- 10681705
TI - A case of very large cyst formation with Gamma Knife radiosurgery for an
arteriovenous malformation.
AB - A 17-year-old male patient underwent Gamma Knife radiosurgery (GKRS) for a left
parietal arteriovenous malformation (AVM), which presented with hemorrhage. The
15.0 cm3 nidus was covered with the 50% isodose. The maximum dose was 50 Gy and
the margin dose was 25 Gy. Eleven months later he developed a right hemiparesis
and MRI showed a large cyst. Cerebral angiography showed partial obliteration of
the AVM nidus. Stereotactic removal of cyst fluid (about 70 cm3) was performed,
and an Ommaya reservoir was inserted. Cyst formation after GKRS for cerebral
arteriovenous malformation is a is side effect of radiosurgery about which we
need to learn more.
PMID- 10681706
TI - The role of Gamma Knife radiosurgery in arteriovenous malformation with
aneurysms.
AB - A review of 217 patients treated with Gamma knife radiosurgery (GKRS), at
Hospital Na Homolce, Prague, between October 1992 and January 1998 for
arteriovenous malformation (AVM) is presented. Forty-one patients (18.9%) with an
AVM and associated aneurysm are the subjects of special interest for this study.
The nidus volume in the presence of an aneurysm lying close to the nidus or
within it was significantly larger than the nidus volume in cases where the AVMs
had no associated aneurysm, suggesting that an increased flow in a larger AVM may
be an important factor for aneurysm formation. The association of an arterial
aneurysm with an AVM significantly increased the chance of hemorrhage when
compared to the group with AVM and no aneurysm. Ten patients out of 14, who had
an aneurysm close to or within the nidus, showed a complete obliteration of their
AVM and aneurysm, although the latter was not always included within the
irradiated volume. Thus, this study indicates that radiosurgery alone could be
the method of choice for the treatment of a combination of AVM and aneurysm, if
the aneurysm is close to or within the nidus.
PMID- 10681707
TI - [The advance of molecular technology in clinical microbiology laboratories].
PMID- 10681708
TI - The isolation results and the antimicrobial agents susceptibility analysis of
Haemophilus from the sputum of the elderly suffering from respiratory tract
disease.
AB - OBJECTIVE: To inform the isolation and antibiotics susceptibility results of
Haemophilus in the sputum of old men suffering from respiratory tract disease so
that the epidemiological information and treatment can be available to
physicians. METHODS: Two groups-group A, patients=562, group B, healthy
volunteers=57 expectorated specimens of sputum were cultured with a special
medium for Haemophilus. The isolates were then identified with API NH
Identification plates and detected with ATB NH antibiotics susceptibility cards,
finally, we got the statistics data of Haemophilus species and antibiotics
susceptibility rates from Datatrac statistic system of VITEK 32. RESULTS:
Haemophilus were detected in 132 specimens out of 562 (23.5%), which includes 6
strains of H. influenzae (4.5%). 122 strains of H. parainfluenzae, 4 strains of
H. aphrophilus (3.1%). At the same time, 3 strains of Haemophilus were isolated
from group B. Following are the susceptibility rates of sixteen antibiotics of
132 strains of Haemophilus, 73.4% to amoxicillin, 92.4% to amoxicillin and
clavulanic acid, 83.3% to cefactor, 90.9% to cefotaxime, 79.5% to cefuroxime
axetil, 52.3% to kanamycin, 25.0% to gentamycin, 72.0% to spectinomycin, 79.5% to
chloramphenicol, 50.0% to tetracycline, 9.1% to erythromycin, 42.4% to
pristhomycin, 49.2% to rosoxacin, 62.96% to pefloxacin, 97.7% to rifampin, 33.3%
to sulfonamides. CONCLUSION: There is a high isolation rate of Haemophilus in the
sputum of the elderly suffering from respiratory tract diseases, The H.
parainfluenzae is the main Haemophilus in our area of study, which it deserves
good attention by clinical microbiological laboratory. In addition, the
antibiotics susceptibility results indicate that this species is more susceptible
to beta-lactams antibiotics and is less susceptible to some others such as
macrolides and aminoglycosides, etc. So, the drug treatment should be based on
these antibiotics susceptibility results in order to guide the specific therapy.
PMID- 10681709
TI - Identification of Lactobacillus species of human origin by a commercial kit,
API50CHL.
AB - The efficacy of a biochemical kit, API50CHL kit, for identification of intestinal
and vaginal lactobacilli from humans was evaluated by comparing with the results
of DNA-DNA hybridization assay. The results showed that in total only 52 of the
172 strains (30.2%) tested were identified correctly by the kit at species level.
Especially all strains of some species, such as Lactobacillus gasseri and
Lactobacillus crispatus, were misidentified as Lactobacillus acidophilus by the
kit. However, the kit was found to be reliable for identification of
Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, and
Lactobacillus salivarius. This suggests that the exact identification of
Lactobacillus isolates from human stool and vaginal specimens by API50CHL kit is
difficult without the support of modern genotypic technique.
PMID- 10681710
TI - [Evaluation of inoculum density prepared by prompt inoculation system and
antimicrobial susceptibility test results by the automated MicroScan WalkAway
system].
AB - The Prompt Inoculation System adapted to the susceptibility testing by the
automated microbiology system, MicroScan WalkAway (Dade MicroScan Inc., West
Sacramento, CA, U.S.A.) was evaluated by determining colony forming units (cfu)
per ml of the inocula and by the susceptibility test results obtained through
repeated testing of the American Type Culture Collection (ATCC) reference strains
described by the National Committee for Clinical Laboratory Standards (NCCLS).
The colony forming units per ml of the inocula prepared by the Prompt ranged
2x10++(5) to 2x10(6)++ cfu/ml for the ATCC reference strains, the results
indicating that the Prompt gave a higher inoculum density and was more
reproducible when compared to the standard turbidity, McFarland adjustment. Also,
most inocula prepared from the clinical isolates, comprising the strains of
Enterobacteriaceae,no-entericbacilli,staphylococci,enterococci, and
streptococci,contained 1x10(6) to 3x10(6) cfu/ml. Although the inocula prepared
by the Prompt contained more viable bacterial cells, the outcome results for
susceptibility testing by the MicroScan WalkAway were highly acceptable. Four
ATCC reference strains were repeatedly tested. Of 540 MIC determinations, 489
(90. 6%) were within the acceptable MIC ranges described by the NCCLS M100-S9,
whereas the inocula prepared by the photometric adjustment gave 87.4%. In
conclusion, the Prompt inocula were found to give more precise susceptibility
test results mostly equivalent to those obtained from inocula prepared by the
conventional photometric procedures.
PMID- 10681711
TI - [Rapid detection of Mycoplasma pneumoniae-specific IgM].
AB - The rapid diagnosis of Mycoplasma pneumoniae infection is important in carrying
out chemotherapy in appropriate manner. It is also essential to detect the
specific immunoglobulin M (IgM) in order to diagnose infectious diseases. The
ImmunoCard Mycoplasma kit (TFB. Inc./Meridian Diagnostics, Inc.) is a 10-min-card
based enzyme-linked immunosorbent assay (ELISA) of IgM antibodies to M.
pneumoniae. The ImmunoCard was compared with high density particle agglutination
(HDPA) and cold hemagglutinin (CHA). The ImmunoCard test had 98.3% sensitivity,
51.4% specificity, and 72.5% agreement with HDPA (>or =320), but it had 94.3%
sensitivity, 87.5% specificity, and 92.2% agreement with clinical diagnosis. Our
results indicate that the ImmunoCard Mycoplasma IgM assay is a rapid, simple and
valuable procedure which can be analyze small numbers of specimens using a less
complicated technique and with no other equipment required. This means that the
ImmunoCard is a cost-effective, energy saving and rapid procedure for the
detection of M. pneumoniae-specific IgM.
PMID- 10681712
TI - [Evaluation of direct identification testing from positive blood culture bottles
with MicroScan rapid identification panels].
AB - We evaluated the direct identification method from growth-positive blood culture
bottles using MicroScan Rapid ID panels (DADE BEHRING) for the purpose of rapid
identification. The inoculum for Rapid ID panels were prepared using an isolation
method from blood culture bottles by VACUTAINER (BD). McF 1.0 had a better result
than McF 0.5 as the inoculum concentration for Rapid ID panels. Rapid ID panel
identification results were effected by blood contamination for > or =0.3% of S.
aureus and 0.9% of a strain of E. coli. Blood contamination from the bottle may
cause an issue to the identification results. The accuracy of this direct
identification testing was 72.0% (36 out of 50) for gram positives organisms and
88. 9% (80 out of 90) for gram negatives organisms. Although some strains
including S. pyogenes, coagulase-negative staphylococci and non-Fermentative Gram
Negative Rods had not identified correctly, this method provides a preliminary
result within 3 hours and provides a fast turn around time. In conclusion, this
method was considered as an effective method for routine testing.
PMID- 10681713
TI - [Evaluation of a fully automated mycobacteria culture system, MB/BacT using a
newly developed digestion-decontamination procedure, semi-alkaline protease-N
acetyl-L-cysteine-NaOH (SAP-NALC-NaOH) method].
AB - A fully automated non-radiometric mycobacteria culture system, MB/BacT (Organon
Teknika, Durham, NC, U.S.A.), was recently introduced in Japan and evaluated for
its ability to detect mycobacteria in clinical sputum specimens. A previous study
yielded nearly a 40% contamination ratio from sputa treated with the standard N
acetyl-L-cysteine (NALC)-NaOH method. This study employed a mucolytic agent (semi
alkaline protease; SAP) in which the sputa were processed twice for digestion
followed by decontamination at twice the standard volume of NALC-NaOH. The
concentrated sediments were resuspended in phosphate buffer (0.067 M, pH 6.8),
and inoculated into the MB/BacT Process Bottles supplemented with antibiotics.
The bottles were incubated at 37 degrees C and monitored for up to fifty-six
days. Recovery of mycobacteria was compared in three different egg-based Ogawa
media in addition to a non-selective Middlebrook 7H10 agar. A total of 1, 124
clinical sputum specimens have been evaluated. Of these, 464 were positive for
growth of mycobacteria, of which 447 (96.3%) were positive by the MB/BacT. False
positive alarms due to break through contamination, mainly by Pseudomonas
aeruginosa and Candida spp., were observed in twenty-one specimens (1.9%). The
three Ogawa media could detect only 283 (60.5%) to 353 (75.4%) positives, and
Middlebrook 7H10 agar only 424 (90.6%) positives. The time to detect positive
cultures of Mycobacterium tuberculosis complex by the MB/BacT ranged from 2.2
days to 52.3 days, and 50% of positive cultures were detected within 16.7 days of
incubation. It can be concluded that the combination of SAP-NALC-NaOH digestion
decontamination procedure and the MB/BacT is particularly useful for the
isolation of mycobacteria and has a faster time to detect than conventional
methods. MB/BacT is a suitable alternative method for the detection of
mycobacteria in Japan, where the radiometric Bactec System is not available.
PMID- 10681714
TI - [Detection of pyrazinamidase activity for differentiation of Campylobacter,
Arcobacter, and Helicobacter spp. by using a high-performance liquid
chromatography method].
AB - A high-performance liquid chromatography method was investigated for the
detection pyrazinamidase activity by Campylobacter, Arcobacter, and Helicobacter
spp. Pyrazine carboxilic acid, one of the end products of pyrazinamide hydrolysis
by microorganisms, was detected by using a high-performance liquid chromatography
(HPLC). A loopful of organism colonies was emulsified in 0.5 ml of a 0.5%
pyrazinamide solution. The suspens on was incubated in a 37 degrees C water bath
for 18-20 hr. After centrifugation, the supernatant was analyzed by HPLC. This
HPLC method does not require microaerobic incubation and was easy to interpret
for strains with weak enzymatic activity. By this method, we tested 111 clinical
isolates, type and reference strains of Campylobacter spp., Arcobacter spp., and
Helicobacter spp. , C. jejuni, C. jejuni subsp. doylei, C. coli, C. upsaliensis,
C. lari, C. lari (urease+), C. helveticus, C. hyolei, C. sputorum subsp. fecalis,
C. gracilis, C. concisus, C. curvus were positive for pyrazinamidase. C. fetus
subsp. fetus, C. hyointestinalis, C. sputorum subsp. sputorum, C. sputorum subsp.
bubulus, C. mucosalis, A. butzleri, A. skirrowii, A. cryaerophilus, H. pylori, H.
cinaedi, H. fennelliae, H. mustelae, H. felis, H. muridarum, H. canis, H.
nemestrinae, H. pamentensis, H. pullourum were negative.
PMID- 10681715
TI - Indolent lymphomas.
PMID- 10681716
TI - Chelation therapy in patients with thalassemia using the orally active iron
chelator deferiprone (L1).
AB - BACKGROUND AND OBJECTIVE: Excessive hemosiderosis is the main reason for the
multi-organ failure observed in multitransfused patients. Deferiprone (1,2
dimethyl-3-hydroxy-pyridine-4-one, L1) is an orally active iron chelator mainly
excreted via urine. We conducted a study in order to determine the efficacy and
safety of L1 in Greek thalassemic patients. DESIGN AND METHODS: A group of 11
thalassaemic patients entered the study; L1, the Cipla formulation for
deferiprone, at a daily dose of 75-100 mg/kg bw t.i.d. was used. After giving
informed consent all patients were subjected to clinical examination and
biological tests. RESULTS: All patients tolerated the L1 well; there were no
significant side effects (except for slight gastrointestinal disturbances for the
first days). The net urinary iron excretion ranged from 6.96 to 26.1 mg/24h.
Serum ferritin declined within 4-6 months in most of the patients. INTERPRETATION
AND CONCLUSIONS: The results suggest that L1 is a rather safe drug which
decreases iron overload without causing any considerable side-effects in Greek
thalassemics.
PMID- 10681717
TI - Analysis of T-cell clones in systemic lupus erythematosus.
AB - BACKGROUND AND OBJECTIVE: It is fairly well established that T-helper (TH)((1))
cells play a role in the pathogenesis of organ-specific autoimmune diseases,
while their role and their relationship with TH((2)) cells is far from being
defined in systemic lupus erythematosus (SLE). To address this issue, six female
patients who fulfilled the American Rheumatism Association criteria for the
diagnosis of SLE were studied. DESIGN AND METHODS: We analyzed the intracellular
production of cytokines by T-cells from the peripheral blood (PB). Then, we
established T-cell clones (TCC) from the peripheral blood (PB) of all cases as
well as from the synovial fluid of one patient with an articular flare-up.
RESULTS: The percentages of IL-4 positive and IFN-g positive PB T-cells were not
different between SLE patients and normal controls. When 93 TCC (67 CD4(+), 23
CD8(+)) from the PB of 5 different SLE patients were compared to 118 TCC (94
CD4(+), 23 CD8(+)) from 5 healthy controls no statistical difference was observed
between SLE and controls in terms of TH((1)), TH((2)) or TH((0)) phenotype.
However, SLE clones showed a reduced ability to secrete IL-10 (p = 0. 002). In
contrast, the analysis of the 30 clones obtained from synovial fluid revealed
that 11/23 CD4(+) clones were TH((1)), 12/23 were TH((0)), 2/7 CD8(+ )clones were
TH((1)) and 5/7 were TH((0)). No TH((2)) clones were obtained from the synovial
fluid. INTERPRETATION AND CONCLUSIONS: The data suggest that the T-cell subsets
operating in actively inflamed organs of SLE may belong to the TH((1)) and
TH((0)) subsets.
PMID- 10681718
TI - Heterogeneity of isolated mononuclear cells from patients with acute myeloid
leukemia affects cellular accumulation and efflux of daunorubicin.
AB - BACKGROUND AND OBJECTIVE: Pharmacologic studies on blasts from patients with
leukemia are generally performed on density gradient isolated blood or bone
marrow cells. Thereby, cellular drug accumulation and efflux are determined as
mean values of the entire cell population. The objective of the present study was
to characterize the heterogeneity in the accumulation and efflux of daunorubicin
in various subpopulations of mononuclear cells isolated from patients with acute
myeloid leukemia (AML). DESIGN AND METHODS: Mononuclear cells from 33 patients
with AML were isolated from peripheral blood by density gradient centrifugation
on Lymphoprep (1. 077 g/mL). Cellular accumulation of fluorescent daunorubicin
was determined by flow cytometry after incubation of the cells at +37C for 1
hour. Thereafter, the cells were washed and reincubated in drug-free medium.
Kinetics of drug efflux were determined by frequent determination of cellular
fluorescence during 30 min. Daunorubicin accumulation and efflux were compared in
the total isolated mononuclear cell population and in the various blast cell
populations gated on FSC/SSC according to the results of immunophenotyping.
RESULTS: In 8 of these 33 (24%) patient samples, two distinct blast cell
populations could be identified. In 7 out of 8 these cases the more immature
blasts had a lower drug accumulation and in 6 out of the 8 cases also a higher
efflux rate than the differentiating cell population. Cyclosporin A increased
daunorubicin accumulation and reduced efflux in the immature blast population. In
the differentiating cell population cyclosporin A increased both the accumulation
and the efflux. In patients with a single blast cell population, the gated blast
cells had a significantly lower drug accumulation but also a lower drug efflux
rate than the total cell population. INTERPRETATION AND CONCLUSIONS: The results
imply that drug transport studies on cells isolated from patients with AML give
somewhat different results depending on the cell population studied. Some, but
not all, of these differences in daunorubicin accumulation and efflux as well as
in the effect of cyclo-sporin A can be explained by a heterogenous expression of
the mdr1-gene. The observed heterogeneity may be of special relevance with regard
to drug resistance. The presence of even a small resistant cell clone may
jeopardize the effect of the chemotherapy due to expansion resulting in relapse
of disease.
PMID- 10681719
TI - Prolonged response to cyclosporin-A in hypoplastic refractory anemia and
correlation with in vitro studies.
AB - BACKGROUND AND OBJECTIVE: Lymphocyte abnormalities in myelodysplastic syndromes
(MDS) have been widely described, but the role of the immune system in the
pathogenesis of these clonal disorders remains controversial. An active role of
lymphocytes in suppressing normal hematopoiesis may be implicated in MDS with
hypoplastic marrow. We have studied in vitro and in vivo activity of cyclosporin
A (CSA) on hematopoiesis in patients affected by hypoplastic MDS without blast
excess. DESIGN AND METHODS: Nine consecutive patients with hypoplastic refractory
anemia (RA), followed up in our out-patient unit, were treated with CSA at daily
doses of 1-3 mg/kg for at least three months. Low dose steroids or danazol were
transiently added in 7/9 patients. Differences between pre- and post-treatment
parameters were studied by the Student's t-test. In vitro effect of CSA on
circulating hematopoietic progenitors was studied by the methylcellulose colony
assay. RESULTS: Before treatment, fewer circulating hematopoietic progenitors
were found in all patients as compared to normal subjects. The number of CD34+
cells was about halved, while circulating erythroid and myeloid colony-forming
cells (CFC) were reduced to one-fifth. After a mean period of 22 months of CSA
treatment (median: 14.5 months), hemoglobin was significantly and persistently
increased in two patients, platelets in one, platelets and hemoglobin in two. Two
patients showed transient responses, one patient did not tolerate the treatment
and one patient is close to a significant response. At in vitro CSA
concentrations similar to those achieved in vivo after oral administration the
drug significantly increased cell colony growth in hypoplastic RA. This test
correctly predicted a positive clinical response to CSA in 3/5 cases and
treatment failure in 4/4 cases. INTERPRETATION AND CONCLUSIONS: About one half of
hypoplastic RA patients benefited from CSA treatment. A larger study could verify
whether in vitro culture of hematopoietic progenitors in the presence of CSA can
predict the clinical response and whether this treatment could prolong patients'
survival.
PMID- 10681720
TI - L-selectin expression is low on CD34+ cells from patients with chronic myeloid
leukemia and interferon-a up-regulates this expression.
AB - BACKGROUND AND OBJECTIVE: Altered adhesive interaction between bone marrow (BM)
stroma and progenitors in chronic myeloid leukemia (CML) may be in part caused by
abnormal expression of cell adhesion molecules (CAMs) on malignant progenitor
cells. Treatment of CML with interferon-a (IFN-a) re-establishes normal
hemopoiesis in some patients in part by restoring normal adhesive interactions
between CML progenitors and BM microenvironment, which may in turn be mediated by
correcting CAM expression on progenitors. DESIGN AND METHODS: We investigated the
expression of CAMs (L-selectin, b((2))-integrin, LFA-3, ICAM-1, ICAM-3, NCAM) on
purified BM CD34(+) cells from CML patients (n= 34) and healthy adults (n= 15) by
flow cytometry. Modulation of L-selectin expression on CD34(+) cells from CML
after in vitro treatment with IFN-a was also investigated. RESULTS: The mean
percentage of CD34(+ )cells expressing L-selectin was significantly lower in CML
patients (25.4+/-12.8%) than in normal controls (68.7+/-8.3%, n=15). CD34(+)/HLA
DR(&endash;/low) and CD34(+)/ CD38(&endash;/low) co-expressing L-selectin were
also significantly lower in untreated CML (27.4+/-21.5% and 39.8+/-26.7%,
respectively, n=8) than in controls (61+/-17% and 83.7+/-10%, respectively, n=7).
In vitro treatment with IFN-a of purified CD34(+) BM cells from untreated CML
patients (n=8) induced a significant, dose and time-dependent increase in the L
selectin expression as indicated by FACS analysis. INTERPRETATION AND
CONCLUSIONS: We hypothesize that this L-selectin deficiency reflects a cell
surface adhesion defect of progenitors from CML that is partially restored by in
vitro IFN-a treatment. These data may help to explain the adhesive abnormalities
of CML progenitors to the BM microenvironment and the in vitro restoration of
adhesion capacity after IFN-a treatment.
PMID- 10681721
TI - Prevalence of Helicobacter pylori and hepatitis C virus infections among non
Hodgkin's lymphoma patients in Southern Switzerland.
AB - BACKGROUND AND OBJECTIVE: Several recent studies have reported a high rate of
previous hepatitis C virus (HCV) infection in patients with non-Hodgkin's
lymphoma (NHL). However, it appears that there are marked geographical
differences in the prevalence of HCV among NHL patients. There is further
controversy concerning a possible pathogenetic link between HCV and certain
histologic lymphoma subtypes, in particular MALT lymphomas, and it has recently
been speculated that HCV might be involved in the multistep process of gastric
lymphoma genesis, in addition to the well established role of chronic
Helicobacter pylori infection. The aim of this study was to investigate the
prevalence of HCV and H. pylori infections in patients with B-cell NHL in
Southern Switzerland. DESIGN AND METHODS: One hundred and eighty newly diagnosed
HIV-negative B-cell NHL patients, consecutively seen at a referral oncology
center in Southern Switzerland between 1990 and 1995 were prospectively studied.
A microparticle enzyme immunoassay was used to detect antibodies to HCV.
Serologic determination of HCV genotype was done by the Murex method. The
quantitative detection of IgG anti-H. pylori was performed by the Biorad GAP
test. RESULTS: Infection with HCV was detected in 17/180 patients (9.4%; 95%
C.I., 6%-15%). This prevalence is significantly higher than that observed in a
large survey of 5424 new blood donors from the same area tested in 1992-97 (0.9%;
95% C.I., 0.7-1.2). Neither histologic subtypes nor specific extranodal
presentations of NHL were associated with a higher prevalence of HCV. HCV
serotype 2 (corresponding to genotypes 2a-c) was the most common. HCV infection
was significantly associated with a shorter progression-free survival at both
univariate and multivariate analysis. Anti-Helicobacter antibodies were detected
in 81/180 patients (45%; 95% C.I., 38%-53%) and H. pylori infection was
significantly associated with the development of primary lymphomas of the
stomach. INTERPRETATION AND CONCLUSIONS: A high prevalence of HCV infection was
detected in NHL lymphoma patients and was associated with a shorter time to
lymphoma progression. HCV infection was not correlated with primary gastric
presentation or with MALT-type histology. Our findings further support the key
role of H.pylori infection in the pathogenesis of primary gastric lymphoma of
MALT-type. The possible role of HCV in the pathogenesis of NHL should be further
investigated.
PMID- 10681722
TI - Validation of the international prognostic index in working formulation group A
low-grade non-Hodgkin's lymphoma: retrospective analysis of 137 patients from the
Gruppo Italiano per lo Studio dei Linfomi registry.
AB - BACKGROUND AND OBJECTIVE: The subset of non-follicular non-Hodgkin's lymphoma
(NHL) includes patients with varied prognoses, thus suitable for different
therapeutic approaches. The International Prognostic Index (IPI), originally
proposed for aggressive NHL, has been demonstrated to be of prognostic relevance
also in follicular NHL. The main aim of the study was to validate the IPI in this
histologic category; in addition, the specific prognostic classification,
currently employed in the Gruppo Italiano per lo Studio dei Linfomi (GISL)
prospective therapeutic trials and based on different features, more similar to
those applied to chronic lymphocytic leukemia, was analyzed. DESIGN AND METHODS:
The present series consists of 137 evaluable patients affected by Working
Formulation group A NHL out of 256 cases referred to the GISL Registry. The
retrospective prognostic study included the evaluation by both univariate and
multivariate analyses of overall survival, response to therapy and response
duration. The IPI was applied as originally proposed. The GISL definition of
indolent and aggressive disease at diagnosis was based on the presence of B
symptoms, bulky disease, anemia and thrombocytopenia. RESULTS: The distribution
of patients in IPI risk groups was rather unbalanced with 18%, 47%, 28% and 7% of
cases classified as low (L), intermediate-low (IL), intermediate-high (IH) and
high (H) risk, respectively. The median overall survival was not reached in
either L or IL risk groups, and was 84.1 and 7.4 months for IH and H risk groups,
respectively (p=0. 0005). A simplified IPI model was designed merging patients in
both intermediate risk groups and the statistical difference of survival retained
its significance. GISL prognostic stratification was demonstrated to have a
significant association with survival, with a median survival of 71.3 months in
aggressive disease and a median survival not reached at 152 months in indolent
disease. Both the simplified IPI model and the GISL risk definition retained
their significance in multivariate analysis for overall survival, while for
response to therapy only the simplified IPI model resulted to be of statistical
significance. In addition, the GISL prognostic stratification identified patients
with different outcomes within the IPI intermediate risk group, with a median
survival of 70.2 months for patients with aggressive disease wheras the median
survival for those with indolent disease was not reached. Finally, a prognostic
score resulting from the integration of the simplified IPI and the GISL system
was statistically validated. INTERPRETATION AND CONCLUSIONS: The retrospective
analysis of this series demonstrates the validity of the IPI in non-follicular
indolent NHL and the usefulness of integrating the IPI parameters with disease
specific prognostic variables.
PMID- 10681723
TI - VACOP-B, high-dose cyclophosphamide and high-dose therapy with peripheral blood
progenitor cell rescue for aggressive non-Hodgkin's lymphoma with bone marrow
involvement: a study by the non-Hodgkin's Lymphoma Co-operative Study Group.
AB - BACKGROUND AND OBJECTIVE: Sequential treatment with the addition of high-dose
therapy (HDT) and peripheral blood progenitor cell (PBPC) rescue has been
reported to be active as front-line therapy in aggressive non-Hodgkin's lymphoma
(NHL) with bone marrow (BM) involvement. We designed an intensive sequential
therapy as front-line therapy in this subset of patients and conducted a phase II
study. DESIGN AND METHODS: Patients with aggressive non-Hodgkin's lymphoma and BM
involvement at diagnosis received 8 weeks of VACOP-B chemotherapy as induction
therapy. The second phase included high-dose cyclophosphamide (HDCY) (7 g/m(2))
with granulocyte colony-stimulating factor (G-CSF) followed by leukaphereses. The
third phase included HDT according to the BEAM protocol or melphalan (140
mg/m(2)) plus total body irradiation (8 Gy in a single dose). RESULTS: Forty
patients were included in the study. According to the intention-to-treat, after
VACOP-B, 11 (27.5%) and 22 (55%) patients achieved complete remission (CR) and
partial remission (PR), respectively. Thirty-four received HDCY. After HDCY, 18
patients (45%) were in CR and 13 (32.5%) in PR. Twenty-nine underwent HDT plus
peripheral blood cell rescue (PBPC) rescue. At the completion of treatment 29
patients (72.5%) were in CR, and 3 patients (7.5%) in PR. The actuarial 3-year
overall survival, disease free survival and failure free survival are 48%, 55%
and 40%, respectively. Overall severe toxicity was 7.5%. INTERPRETATION AND
CONCLUSIONS: This phase II study suggests that the intensified treatment
described is feasible and active in aggressive NHL with BM involvement. A
randomized trial is now underway to test this approach.
PMID- 10681724
TI - Autologous stem cell transplantation for high-risk Hodgkin's disease: improvement
over time and impact of conditioning regimen.
AB - BACKGROUND AND OBJECTIVE: High-dose chemo/radiotherapy with autologous stem cell
support is increasingly being used in Hodgkin's disease (HD) patients who do not
respond to or who relapse after conventional chemotherapy. In this work we
analyze the results of 56 consecutive high-risk HD patients autografted in our
institution and the role of possible prognostic factors. DESIGN AND METHODS:
There were 34 males and 22 females with a median age of 31 years. At
transplantation, 24 patients (43%) were in complete remission and 32 (57%) were
autografted while with active disease. Twenty-nine patients were autografted
before January 1993. Bone marrow was used as the source of stem cells in 40
patients (71%) and peripheral blood (PB) in 16 (29%). Forty-five patients
received chemotherapy-based conditioning regimens (40 CBV and 5 BEAM) while the
remaining 11 received cyclophosphamide (Cy) and total body irradiation (TBI).
RESULTS: Two bone marrow transplantation (BMT) recipients did not engraft.
Hematologic recovery was significantly faster in patients transplanted with PB
progenitor cells. Early transplant-related mortality (early TRM) (before day 100
after transplantation) was 9%; it was higher in patients transplanted before
January 1993 than in patients transplanted afterwards (14% vs 4%) and in patients
receiving TBI (18% vs 7%), although these differences did not reach statistical
significance. Overall TRM (before and after day 100) was 14%. TBI-containing
regimens significantly increased overall TRM (36% and 9%, p = 0.03). Actuarial
3.5-year overall survival (OS), event-free survival (EFS) and progression-free
survival (PFS) were 57%, 58% and 65%, respectively. On multivariable analysis,
TBI containing regimens and transplantation before 1993 significantly reduced OS
and EFS. INTERPRETATION AND CONCLUSIONS: Our results confirm that high-dose
therapy followed by autologous stem cell transplantation is associated with
sustained PFS in a remarkable proportion of patients with HD unlikely to be cured
with standard chemotherapy. Results improved over time and TBI containing
regimens had a negative effect on post-transplant outcome.
PMID- 10681725
TI - Myeloid mixed chimerism is associated with relapse in bcr-abl positive patients
after unmanipulated allogeneic bone marrow transplantation for chronic
myelogenous leukemia.
AB - BACKGROUND AND OBJECTIVE: Although bcr-abl polymerase chain reaction (PCR)
positivity after bone marrow transplantation (BMT) for chronic myelogenous
leukemia (CML) is significantly related to relapse, the predictive value of the
assay is not very high and therefore most investigators consider that qualitative
RT-PCR data alone are too imprecise to enable clinical decisions to be taken in
individual cases. To define the clinical outcome of bcr-abl positive patients
after unmanipulated BMT better, we sought the origin of hematopoiesis and traced
its evolution over time. DESIGN AND METHODS: Forty-nine patients received
allogeneic BMT for CML (39 in chronic phase and 10 in accelerated phase/blast
crisis). Median follow-up was 61 months (range 4-92). mRNA and DNA were used to
assess bcr-abl and chimerism status respectively. Quantitative VNTR-PCR on total
cells and lymphoid or myeloid population allowed us to assign and measure the
origin of hematopoiesis. RESULTS: Both bcr-abl positivity and the presence of
mixed chimerism (MC) were significantly associated with relapse (p = 0.0009 and p
< 0.0001 respectively). Relapse was observed in one of 39 patients with complete
donor chimerism and in 6 of 9 patients with MC. These six cases showed increasing
levels of host hemopoiesis and bcr-abl positivity in the CD15-positive population
prior to relapse. The other three cases had decreasing or stable low-level MC
which was restricted to the T-cells as well as bcr-abl negativity. INTERPRETATION
AND CONCLUSIONS: Whereas the simple detection of bcr-abl fails to identify
patients who will relapse with certainty, the assessment of MC by VNTR-PCR does
identify patients headed to relapse. Confirmation of myeloid involvement and
increasing levels over time further elucidates the clinical outcome of bcr-abl
positive patients after BMT.
PMID- 10681726
TI - Prevalence of TT viral DNA in italian blood donors with and without elevated
serum ALT levels: molecular characterization of viral DNA isolates.
AB - BACKGROUND AND OBJECTIVE: A novel non-enveloped DNA virus, called TT virus (TTV),
has been reported to be associated with post-transfusion hepatitis of unknown
etiology. Although its clinical role still remains obscure, its presence in blood
donations might cause problems. It, therefore, appeared of interest to
investigate TTV prevalence in voluntary blood donors. DESIGN AND METHODS: A total
of 595 Italian blood donors with and without elevated serum alanine
aminotransferase (ALT) levels were tested by polymerase chain reaction using two
sets of semi-nested primers that amplify the well-known region in the N22 clone.
The amplified products were then sequenced to assess the genotype by phylogenetic
and restriction fragment length polymorphism analyses. RESULTS: The prevalence of
TTV in blood donors was 5+/-1.9% (25 out of 500) with a 95% confidence limit. A
similar prevalence was found in 95 selected blood donors with increased ALT
levels. A viral load of 10(3)-10(4) viral DNA molecules/mL was found, thus
indicating a rather narrow range of variability. A phylogenetic tree built up on
the basis of 210 base sequences of ORF1 allowed isolates to be classified into 2
groups corresponding, at least, to two of the putatives TTV genotypes, group 1
and group 2 of Okamoto's classification. A similar classification was also
obtained by site restriction enzyme analysis. INTERPRETATION AND CONCLUSIONS: The
results show that TTV infection is present among Italian blood donors. No
significant difference in prevalence of TTV infection was found between patients
with normal and increased ALT, making the association between TTV infection and
human hepatitis questionable.
PMID- 10681727
TI - Relative sensitivity of direct antiglobulin test, antibody's elution and flow
cytometry in the serologic diagnosis of immune hemolytic transfusion reactions.
AB - BACKGROUND AND OBJECTIVE: Current immunohematology practice dictates that
serologic diagnosis of immune hemolytic transfusion reactions (IHTR) is based on
the finding of a positive post-transfusion direct antiglobulin test (DAT).
However, since DAT may fail to detect antibody-coated cells when they constitute
a minor population amid a large number of non-sensitized ones, we investigated
whether antibody detection in eluates or by flow cytometry is more sensitive than
DAT in this context. DESIGN AND METHODS: Ten samples of red blood cells
sensitized with allo- or autoantibodies were diluted in non-sensitized red blood
cells to final concentrations ranging from 10% to 0.1%. DAT, antibody detection
in eluates, and immunofluorescence by flow cytometry were performed on each
mixture. RESULTS: DAT failed to detect sensitized cells in all but two cases in
that only the 10% dilution yielded a positive DAT. Antibody detection in eluates
and by flow cytometry was able to detect up to 1% sensitized cells in most cases.
INTERPRETATION AND CONCLUSIONS: Antibody detection in eluates and by flow
cytometry is more sensitive than DAT for detecting minor populations of IgG
coated cells. These techniques should be included in the routine investigation of
suspected cases of IHTR.
PMID- 10681728
TI - Alternative therapies and the Di Bella affair in pediatrics. A questionnaire
submitted to Italian pediatric oncologists and hematologists.
AB - BACKGROUND AND OBJECTIVE: Over the last 2-3 years in particular, the so-called Di
Bella therapy (DBT) become the most famous of alternative treatments applied to
pediatric oncology and hematology in Italy. Many Italian oncologists and
hematologists had to cope with the problems that it introduced and the treatment
also elicited heated reactions all over Europe. We attempted to evaluate the
impact of this treatment on children with cancer. DESIGN AND METHODS: A
questionnaire prepared with the aim of addressing the use of alternative
therapies in pediatric hematology and oncology was circulated to the 48 centers
(or divisions) belonging to AIEOP (Associazione Italiana di Oncoematologia
Pediatrica) [Italian Pediatric Oncology and Hematology Association] and FONOP
(Forza Operativa Nazionale di Oncologia Pediatrica) [National Pediatric Oncology
Task Force]. The questionnaire consisted of 9 questions elaborated to give credit
to the case-related and professional experiences of the colleagues we contacted.
RESULTS: Forty-three centers replied to the questionnaire. Request to switch to
DBT represented a considerable problem, involving the vast majority of centers
participating into this study; however, case quantification varied greatly from
center to center. One of the most significant aspects is that children switched
to DBT, abandoning conventional therapies, were often relapsing or had had
multiple relapses (from solid tumor or leukemia), but some children abandoned
conventional therapies at an early stage and/or without fully exploiting the
curative potential of these therapies. INTERPRETATION AND CONCLUSIONS: This study
allowed us to obtain an evaluation of the impact of DBT in children with
oncologic or hematologic disorders. It also highlights the importance of
cultivating physician-parent dialogue and provides an opportunity for a few
pedagogic thoughts on the attitude and opinions of pediatricians on this problem.
PMID- 10681729
TI - Molecular pathophysiology of indolent lymphoma.
AB - Indolent lymphomas are a markedly heterogeneous group of lymphoproliferative
disorders including B-cell chronic lymphocytic leukemia/small lymphocytic
lymphoma, lymphoplasmacytoid lymphoma, follicular lymphoma, mantle cell lymphoma
and mucosa-associated lymphoid tissue (MALT) lymphoma. The molecular
pathophysiology of indolent lymphoma is characterized by distinct genetic
pathways which selectively associate with different clinico-pathologic categories
of the disease. At diagnosis, B-cell chronic lymphocytic leukemia frequently
display deletions of 13q14, trisomy 12 and alterations of the ATM gene, whereas
evolution to Richter's syndrome is associated with disruption of p53.
Lymphoplasmacytoid lymphoma carries t(9;14) (p13;q32) in approximately 50% of
cases, leading to the deregulated expression of the PAX-5 gene. Follicular
lymphoma consistently harbors rearrangement of BCL-2. With time, a fraction of
follicular lymphoma accumulates mutations of p53 and of p16 and evolves into a
high grade lymphoma. MALT-lymphoma frequently associates with alterations of
API2/MLT and, in some cases, of p53, BCL-6 and BCL-10. Studies of genotypic and
phenotypic markers of histogenesis have shown that mantle cell lymphoma and a
fraction of B-CLL/SLL derive from naive B-cells, whereas follicular lymphoma,
lymphoplasmacytoid lymphoma and MALT-lymphoma originate from germinal center (GC)
or post-GC B-cells. The identification of distinct genetic categories of indolent
lymphoma may help in the therapeutic stratification of these disorders. In
addition, genetic lesions of indolent lymphoma provide useful molecular markers
for disease monitoring by high sensitivity techniques.
PMID- 10681730
TI - Dendritic cells: specialized antigen presenting cells.
AB - Renewing interest in cancer immunotherapy reflects the excellent results that
have been obtained in animal models and the promising results in early clinical
trails with dendritic cell (DC) based approaches. The central role that DCs play
in the initiation of an immune response raises the possibility of using them to
trigger specific anti-tumor immunity. In addition, deeper knowledge of DC biology
will allow better understanding of the mechanism(s) underlying allergic and
autoimmune diseases as well as tolerance phenomena. These crucial issues were
critically reviewed during a workshop organized by the Italian Society for
Experimental Hematology in Florence, Italy, on March 18th, 1999. The chairmen
have prepared this report for the readers of Haematologica.
PMID- 10681731
TI - Reversible adult respiratory distress in primary antiphospholipid syndrome.
AB - Antiphospholipid antibody syndrome (APS) is a disorder caused by circulating
antibodies reacting with biological membranes and characterized by recurrent
thrombosis, chronic thrombocytopenia and miscarriages. It has been reported to
occur either as a primary syndrome or secondary to systemic autoimmune disorders.
We describe a case of primary APS in a young patient, in whom the clinical course
was particularly severe and complicated by a respiratory distress syndrome. The
patient was resistant to a number of treatments, and eventually responded to
intravenous high dose corticosteroids.
PMID- 10681732
TI - Unexpected consequence of splenectomy in composite lymphoma. The abscopal effect.
PMID- 10681733
TI - Fatal bone marrow aplasia during interferon-a treatment in chronic myelogenous
leukemia.
PMID- 10681734
TI - Does interferon-a exert an anti-leukemic effect by enhancing cell mediated
immunity in chronic myeloid leukemia?
PMID- 10681735
TI - Absence of bcr/abl rearrangement in 41 patients with essential thrombocythemia.
PMID- 10681736
TI - Cladribine as monotherapy or combined with dexamethasone and idarubicin or
mitoxantrone in previously treated patients with low-grade lymphoid malignancies.
PMID- 10681737
TI - Cyclophosphamide/cyclosporin-A treatment of multicentric Castleman's disease with
Kaposi's sarcoma.
PMID- 10681738
TI - High-dose ifosfamide and etoposide infusion plus methylprednisolone for
refractory or relapsed aggressive non-Hodgkin's lymphoma.
PMID- 10681739
TI - Transfusion requirement can be abolished by epoietin-a and autologous platelet
predeposit in patients receiving high dose chemotherapy with stem cell support.
PMID- 10681740
TI - Ultrasound scan to detect acalculous cholecystopathy in immunocompromised hosts
with unexplained fever.
PMID- 10681741
TI - Fludarabine containing regimen followed by autologous peripheral blood stem cell
transplantation in unselected patients with acute myeloid leukemia: a single
center experience.
PMID- 10681742
TI - [Modulated effects of prostaglandin E2 on endothelin production of alveolar
macrophages in rats].
AB - Using radioimmunoassay, we studied the endothelin (ET) production of alveolar
macrophages(AM) of the rats. The results showed that: (1) a basal amount of ET
which was time-dependent (r = 0.7415, P < 0.01) was detected in supernatant of
cultured unstimulated AM; (2) lipopolysaccharide (LPS), PMA, or A23187 could
increase the ET production of AM (P < 0.01) (3) calmodulin antagonist W7 reduced
the ET production of LPS or A23187-stimulated AM (P < 0.05, P < 0.01), but did
not effect that of PMA-stimulated AM; protein kinase C inhibitor H7 attenuated
the effect of PMA on ET production (P < 0.01), but did not effect LPS on ET
production; (4) prostaglandin E2 (PGE2) inhibited the ET production of LPS
stimulated (P < 0.05) and PMA-stimulated AM (P < 0.05); cyclooxygenase inhibitor
indomethacin enhanced the effect of LPS on ET production (P < 0.01), but did not
effect PMA on ET production. We conclude that AM is an important source of ET in
the lungs both at physiologic and pathologic situation there are two pathways of
signal transduction for factors stimulating ET production of AM, i.e., PKC
dependent and Ca(2+)-calmodulin-dependent pathways; the autocrine PGEs from AM
shows a negatively modulated effect on ET production of AM.
PMID- 10681743
TI - [Identification of antigens shared between Schistosoma japonicum and Trichinella
spiralis].
AB - Cross-reactivity was analysed between the antigen of T. spiralis muscular larvae
and antigens of cercariae, liver stage schistosomula, 30 day male and female
adult worms of S. japonicum by means of EITB technique. The result showed that
the antigens of cercariae schistosomula, female worms except male worms, were
recognized by sera from rabbits immunized with T. spiralis antigens or by sera
from T. spiralis infected rabbits. The molecular weight of recognized antigens
ranges from 15 to 100 kD, mainly from 50 to 70 kD. The immunized rabbit sera and
the infected rabbit sera reacted with the same cross-antigens of S. japonicum.
Among these schistosome stages, the cercariae showed the most cross-reactive
bands, the second were the liver stage schistosomula, and 30 day female worms
only showed a weak band which located at 97 kD position. Meanwhile, the anti-S.
japonicum sera recognized several T. spiralis antigens which located at 34 kD and
above, especially 35-38 kD. The results suggest that there are many antigens
shared between T. spiralis and S. japonicum and the main cross-reactive antigens
are found in the larva stages of S. japonicum and T. spiralis muscular larva. The
cross-reactive antigens are different between various stages of S. japonicum and
muscular larva of T. spiralis.
PMID- 10681744
TI - [Detection of human cytomegalovirus by PCR in patients with gastrointestinal
disease].
AB - Human cytomegalovirus (HCMV) genomes was detected by PCR in 51 patients' biopsy
or operation specimens with gastrointestinal disease. The positive rate was
9.80%. At the same time, 41 patients' serum HCMV-IgM was detected by indirect
immunofluorescence assay (IFA); the positive rate was 46.34%. Patients with
cancer and colitis exhibited a higher HCMV infection rate than those without
cancer and colitis. The results suggest that PCR is sensitive and specific in
detection of gastrointestinal HCMV infection, and the examination of biopsy or
surgical specimen is superior than that of IFA of serum HMCV-IgG.
PMID- 10681745
TI - [Genotype distribution of hepatitis C virus in hepatocellular carcinoma tissue in
Hunan province].
AB - Genotypes of hepatitis C virus(HCV) were detected by PCR using type-specific
primer in 50 patients' hepatocellular carcinoma(HCC) tissue. The results showed
that in the 50 HCC specimens, 30(60%) and 3(6%) were infected with the HCV type
II and III, 5(10%) and 8(16%) with type II + III and type II + IV, 2(4%) with
type II + I + III in combination, respectively. 2 cases were negative for HCV.
These data suggest that HCV type II may be a predominant genotype related to
hepatocarcinogenesis in Hunan Province, some cases of HCC may result from
coinfection of HCV type II and other genotypes, and only few HCC be separately
caused by infection of HCV type III.
PMID- 10681746
TI - [The relationship between C-erbB-2 expression with cell proliferative activity
and prognosis of nasopharyngeal carcinomas].
AB - C-erbB-2 and proliferating cell nuclear antigen (PCNA) were detected by
immunohistochemical and in situ hybridization methods in nasopharyngeal
carcinomas(NPC) and pericarcinomatous tissues(PCT). Some NPC cases were followed
up for more than 5 years. RESULTS: The positive rates of C-erbB-2 protein and C
erbB-2 mRNA expression were 87.8%, and 84.0%, respectively in NPC and 74.6% and
76.5%, respectively in PCT. There was a coexpression of C-erbB-2 protein and
mRNA. The significant difference for PCNA staining intensity index(S II) existed
in the vesico-nuclear and poorly differentiated types of NPC and in the C-erbB-2
staining cases of NPC. No correlation was found between the expression of C-erbB
2 protein and the clinical stage and metastasis as well as survival rate.
CONCLUSION: The C-erbB-2 gene overexpression and cell abnormal proliferation are
associated with the carcinogenesis and development of NPC. It is helpful to
examine both C-erbB-2 gene expression and PCNA in NPC to evaluate the malignant
degree and the effect of radiotherapy.
PMID- 10681747
TI - [An ultrastructural observation of peripheral blood neutrophils in patients with
hepatitis B].
AB - The abnormal changes of peripheral blood neutrophils in 13 patients with
hepatitis B were observed under electron microscope. The morphological and
structural changes of neutrophils included irregularity of shape, a large number
of pseudopodia and phagocytic vacuoles, less electron dense granules, increased
nuclear holes and vacuoles, etc. The present study provides the ultrastructural
evidence of impaired neutrophil morphology and functions in such patients.
PMID- 10681748
TI - [Significance of microvessel quantity in metastasis of invasive breast
carcinoma].
AB - Microvessel quantity(MVQ), expression of CD44V6 and EGFR were studied in 48
patients with invasive breast carcinoma by CD31 immunohistochemistry. Significant
differences of MVQ, CD44V6 and EGFR were observed (P < 0.01) between the groups
with and without metastasis. The results suggest that angiogeneses and activation
of tumor metastasis associated gene play an important role in tumor metastasis.
PMID- 10681749
TI - [Influence of portal triad clamping on the intestine in pigs].
AB - A pig model of liver ischemia and intestinal congestion was made by portal triad
clamping (PTC) for 45 minutes to investigate the influence of PTC on intestine.
The results were as follows: 1. The level of cathepsin D was increased
significantly after PTC as compared with the value before clamping (P < 0.05); 2.
The endotoxin and lactic acid were significantly increased after PTC comparing
with those of pre-clamping (P < 0.05, P < 0.01) and the control group (P < 0.05,
P < 0.01); 3. The intestinal mucosa had a significant damage (P < 0.05) after
PTC. The results indicate that PTC can result in intestinal mucosal lesion and
enterotoxin absorption. Therefore, the protection of intestinal functions is
important in hepatic surgery and preoperative bowel preparation should be done.
PMID- 10681750
TI - [The effects of hypertonic saline/mannitol resuscitation on the myocardiac
contractility and blood pressure of rabbits with hemorrhagic shock].
AB - Eighteen healthy adult male rabbits were hemorrhaged to shock and treated with
hypertonic-hyperoncotic solutions in 3 groups (6 per group): hypertonic
saline/dextran(HSD), hypertonic saline/mannitol(HSM) and hypertonic
acetate/mannitol(HAM). The results showed that HSM. HAM and HSD could raise the
left ventricular pressure(LVP), maximum change rate of LVP (+/- dp/dt max) and
the arterial blood pressure of hemorrhagic shock rabbits quickly at small dose.
The efficiency of HSM was better than that of HSD and HAM (P < 0.05), and the
time of blood pressure rise was in accordance with that of LVP and +/- dp/dt max,
which may partly explain the mechanism of shock resuscitation by hypertonic
hyperoncotic solution.
PMID- 10681751
TI - [Study on the immunoregulatory effect of Baoyuantang ([symbol: see text]) in
patients with chronic hepatitis B].
AB - The T lymphocyte colong, formition (TL-CFU), the T lymphocyte subsets (CD3+, CD4+
and CD8+) and interieakin-2 membrane receptor (mIL-2R) secreted by peripheral
mononuclear cells of 60 patients with chronic B hepatitis were studied. The
results indicated that the activity of TL-CFU, mIL-2R and CD3+, CD4+, CD4+/CD8+
were decreased, and CD8+ was increased as compared with the normal controls.
After treatment with Baoyuantang, the TL-CFU, mIL-2R, CD3+, CD4+ and CD4+/CD8+
increased and CD8+ decreased as well. It is suggested that the patients with the
chronic B hepatitis with immune function defficiency, and the Baoyuartan
treatment is presented immunoregulatory.
PMID- 10681752
TI - [Infection of cryptosporidium in child patients with diarhea in Changsha].
AB - Fecal specimens were collected from 102 outpatients with diarrhea in Children's
Hospital from March to October, 1997. The fecal smears were examined for
cryptosporozoites with the rapid modified acid-fast two-step methods. The
positive rate was 4.90%(5/102). There was no significant difference between
female and male (P > 0.05). The positive rates of 1-month-, 5-year-, and 10-year
old groups were 4.05% (3/74), 7.14%(1/14), and 7.14(1/14), respectively. We
conclude that there is crytosporidium infection in child patients with diarrhea
in different sex and age groups.
PMID- 10681753
TI - [Dental fluorosis of brick tea type in rats].
AB - To observe the dental fluorosis of brick tea type, 48 white rats were fed by 245
mg.L-1 of brick tea, respectively. The rat model of brick tea type fluorosis were
successfully established after 90 days. Naked eye examination of rats' incisors
showed that brick tea and sodium fluoride (as positive control) groups all
suffered from dental fluorosis. Using the dissecting microscope, the scanning
electron microscope, and the energy spectrum apparatus, we also proved that the
high concentration of brick tea could cause dental fluorosis.
PMID- 10681754
TI - [Relationship between osteoporosis and metabolism of calcium and bone].
AB - Using metabolic balance test, bone mineral density measurement, animal models of
osteoporosis, bone cell culture, we investigated the relationship between
osteoporosis and the metabolism of calcium and bone. We found that the calcium
intake was rather low in 20 healthy adults (480 mg per day); the average
intestinal net absorption rate(%) of calcium in 124 healthy adult volunteers was
28.9(%), which increased gradually in recent 20 years (from 17.1% in 1978 to
40.6% in 1977), owing to improvement of dietetic structure. We conclude that the
insufficiency of sex hormone and calcium are the main causes of osteoporosis. In
bone cell culture, the whole process of bone remodelling was observed for 35 days
continuously. Calcitonin damaging osteoclast was also investigated. Thus, we
suggest new concept of bone remodelling coupling.
PMID- 10681755
TI - [Mifepristone in the treatment of 47 ectopic pregnancy patients].
AB - OBJECTIVE: To investigate the effect and indication of mifepristone in treating
ectopic pregnancy, 47 patients were divided into three groups. RESULTS: Twenty
nine cases were effective; 18 cases were ineffective and operated on in which we
observed the gestational termination, bleeding capacity, and pathological changes
in fallopian tube. We found that the effect was related to the drug dosage,
levels of beta-hCG in blood and the operating time. CONCLUSION: High dosage of
mifepristone in treating ectopic pregnancy is convenient, safe, and has no side
effects. It is suitable for patients with early ectopic pregnancy who have smooth
life-sign, beta-hCG < 10 ng.ml-1, the mass in pelvic cavity < or = 5 cm, without
acute belly-ache and pulsation of fetal heart in fallopian tube and who ask for
the conservative treatment.
PMID- 10681756
TI - [A study on HBV DNA pre C region A83 mutation in patients with hepatitis B].
AB - Mismatched polymerase chain reaction (MPCR) and restriction fragment length
polymorphism assay(RFLP) were performed to detect the HBV DNA pre core A83
mutation in 97 patients with chronic HBV infection in Hunan. HBV DNA pre core A83
mutation were detected in 37 out of 97 patients (37/97,38.1%). It was found that
the prevalence of HBV DNA pre core A83 mutation of the patients with severe
hepatitis and with CAH(chronic active hepatitis) were significantly higher than
those with CPH(chronic persistent hepatitis) and carriers of HBV, and the
patients with elevated transaminase (ALT > 70U) or positive HBeAb were
significantly higher than those with normal transaminase (ALT < 70U) and with
positive HBeAg, respectively. The results suggest that the HBV DNA pre core A83
mutation is associated with active and severe liver tissue in patients with
hepatitis B.
PMID- 10681757
TI - [Changes of tissue oxygenation and relationship between oxygen delivery and
consumption in patients with poor cardiac function undergoing valve replacement].
AB - To study the relationship between oxygen delivery(DO2) and consumption(VO2) and
tissue oxygenation in patients during cardiac valve replacement, DO2, VO2,
arterial blood lactate (ABL) SvO2 were measured. The results showed a poor
correlation between DO2 and VO2 and a normal tissue oxygenation before CPB. There
was a good positive correlation between DO2 and VO2 within 20 h after the end of
CPB(P < 0.01), and changes of ABL and SvO2 showed tissue hypoxia. The level of
ABL in patients showing O2 supply-dependency was lower, and SvO2 was higher than
those in 15 patients showing O2 supply-independency, respectively (P < 0.05).
These data suggest that O2 supply-dependency was existed after the end of CPB,
and there was a good correlation between O2 supply-dependency and ABL. It might
not exclude tissue hypoxia in O2 supply-independency and normal level of SvO2.
PMID- 10681758
TI - [Dynamic enhanced MR imaging of intraspinal tumors].
AB - The dynamic enhanced MR imaging of 37 patients with intraspinal tumors were
performed. We found that the enhancement peak within 90s was shown only in
hemangioblastoma, within 180s was shown in most astrocytomas, meningiomas, and
metastases. The maximum contrast enhancement ratio (MCER) of neurilemmoma is
higher than that of meningioma(P > 0.05). We conclude that the contrast
enhancement ratio-time(CER-T) curve, the enhanced degree, and pattern of
intraspinal tumors have the significant value for the histologic diagnosis and
the calculation of vascularity.
PMID- 10681759
TI - [Serum HBV DNA detected by polymerase chain reaction with dUTP/uracil-DNA
glycosylase].
AB - The ability of PCR reagent containing dUTP/uracil-DNA glycosylase for controlling
carry-over contamination of PCR products was explored. All of 204 sera taken from
hepatitis patients were used for HBV DNA detection by PCR with PCR-dUTP/UDG
reagent in comparison with that without dUTP/UDG. The results showed that its
efficiency of controlling contamination was excellent. At least, contamination of
100 ng PCR products was got rid of. The corresponding rate of HBV DNA detection
by PCR-dUTP/UDG in combination with dot hybridization using digoxin-labeled HBV
probe was as high as 89.32%, higher than that (81.45%) of PCR without dUTP/UDG
plus dot hybridization(P < 0.05). It suggests that PCR-dUTP/UDG method could
prevent PCR products from contaminating and increase accuracy and specificity of
PCR amplification.
PMID- 10681760
TI - [Parkinson's disease and dementia].
AB - Neuropsychological tests were carried out in 30 patients with Parkinson's disease
and 26 healthy controls. The results showed that the average scores of HRB(A)-RC
test were above the limited scores, 45.45%-86.36% cases being over the limited
scores (P < 0.01), except speech sound perception test. Damage degrees (DQ) from
the least to the most serious were 63.64%. WAIS-RC test and WMS test showed that
the average scores of IQ and MQ in patients were lower than those in the normal.
The difference of IQ, MQ scores between patients and controls was very
significant (P < 0.01). The damaged cases of IQ, MQ from the least to the most
serious were 20% and 60%, respectively. This indicated that the patients with
Parkinson's disease were obviously damaged in intelligence and memory. In this
article, there were 6 cases (20%) fitted the diagnostic standard of dementia,
among them, 4 were subcortical dementia and 2 cases were complex dementia. We
found that the differences between the course and IQ, MQ were very significant (P
< 0.05), but not between the course and DQ. It is implied that in the very early
stage, the patients could appear abnormal in neuropsychology, and the
intelligence and memory may be damaged more seriously in longer course. The
result suggests that the early diagnosis and prompt intervention is important to
prevent the occurrence and advance of dementia.
PMID- 10681761
TI - [Antitumorigenic immunocompetence of alveolar macrophages in patients with lung
cancer].
AB - OBJECTIVE: The antitumorigenic immunocompetence of alveolar macrophages(AMs) in
patients with lung cancer was investigated. METHODS: Twenty-two patients with
lung cancer and 18 control subjects underwent bronchoalveolar lavage (BAL) by
fiberoptic bronchoscopy to collect BAL fluid (BALF). AMs in the BALF isolated by
adherence on plate surface were incubated for 24 hours at 5% CO2, 37 degrees C in
medium with or without granunocyte-macrophage colony stimulating factor (GM-CSF).
The cell free supernatants (SP) and AMs were harvested, respectively, the
activities of nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha),
superoxide dismutase (SOD), and soluble interleukin 2 receptor in BALF and SP
were examined by copper plating cadmium reduction, radioimmunoassay, xanthine
oxidase assay, and ELISA, respectively. mRNA expression of inducible nitric oxide
synthase in AMs was detected by reverse transcription-polymerase chain
reaction(RT-PCR). RESULTS: (1) The activity of NO was lower in BALF of the tumor
bearing lungs than that of the nontumor-bearing lungs and control groups; the
activities of TNF alpha, SOD, and sIL-2R were not statistically significant in
BALF between patients with lung cancer and control groups. (2) In supernatants,
the activities of NO and TNF alpha were lower in the tumor-bearing lungs than in
nontumor-bearing lungs and control groups; sIL-2R concentration of the lung
cancers was higher than that of control groups. (3) After AMs were stimulated by
GM-CSF, the activities of NO, TNF alpha, and SOD were increased and that of sIL
2R was decreased in SP. (4) mRNA expression of iNOS was demonstrated in AMs of
both groups. However, in comparison with beta-actin, the intensity of mRNA
expression of iNOS in AMs of lung cancer patients was lower than that of control
groups. CONCLUSION: There are some deficiencies in the function of AM at the
region of tumors and antitumorigenic immunocompetence in the patients with lung
cancer.
PMID- 10681762
TI - [Expression of telomerase in acute leukemia].
AB - To understand the expression patterns of telomerase activity in different types
of acute leukemia(AL) and during remission state, the mono-nuclear cells of
different bone marrow samples were isolated by desity gradient centrifugation.
Telomerase activity of the samples was assayed by telomeric repeat amplification
protocol(TRAP) with the cell extracts and the TRAP products were resolved in
PAGE. The results showed that the telomerase activity was at higher levels in the
acute leukemia compared with the normal controls. Of the acute nonlymphocytic
leukemia(ANLL), the telomerase activity presented as M2a > M5b > M1 > M3b. Of the
acute lymphocytic leukemia(ALL), the activity presented as L1 > L2. The activity
assayed in M2a and L2 remission was as high as that in the normal group. It
indicated that the expression of telomerase was enhanced differently among the
subtypes of ANLL and ALL, and was down-regulated during the AL remission. It
implicates that the expression patterns of telomerase activity in AL is
associated with the different proliferation states and differentiation properties
of the AL cells.
PMID- 10681763
TI - [A preliminary report of antiscar formation effect by subconjunctival injection
of mitomycin C before trabeculectomy in glaucoma].
AB - To improve the function of filtering blebs and increase the successful rate of
the trabeculectomy, mitomycin C injection 0.02 mg.ml-1 was given
subconjunctivally at the operative site before trabeculectomy in 32 patients (38
eyes) with moderate or late glaucoma. All patients were followed up for 6 to 12
months. The results showed that the rate of functional blebs were 93.7%. The
successful rate of the operation was 94.7%. The common postoperative complication
was shallow anterior chamber (7.9%). These findings indicate that the
subconjunctival injection of mitomycin C before operation is a safe, effective
method for antiscar formation.
PMID- 10681764
TI - [Changes of blood supply from portal system after transcatheter arterial
chemoembolization in huge hepatocellular carcinoma].
AB - OBJECTIVE: Blood supply changes of the portal venous system to the tumor mass
before and after transcatheterarterial chemoembolization(TACE) in a series of 22
patients with huge hepatocellular carcinoma were monitored to study the necessity
of intervention via portal vein. METHODS: Twenty-two selected patients with huge
hepatocellular carcinoma were enrolled in the study. Elscint double helical CT
was used to scan liver during the maximum concentration of contrast medium in
portal venous system. CT Angiography and MIP(Maximum Intensity Projection) were
used to image formation of the portal venous system. RESULTS: The technique of
scan and image formation were excellent to evaluate the attribution of portal
venous blood supply to HCC. The portal venous blood supply was mainly the tumor
periphery distribution (P < 0.01). After treatment of TACE, the portal venous
blood supply to tumor periphery increased significantly (P < 0.05), and some did
appear signs of enriched blood supply around the tumor. Negative correlation
between the degree of reduction in tumor and portal venous blood supply to the
tumor periphery before TACE was evident. CONCLUSION: The attribution of portal
venous blood supply to HCC was in the tumor periphery, and regression of tumor
after TACE was affected by portal venous blood supply to the tumor, thus it is
reasonable to suggest interventional therapy via portal vein.
PMID- 10681765
TI - [Plasma levels of lipids, lipoproteins and apolipoproteins affected by endogenous
testosterone].
AB - Plasma testosterone(T), estrodiol(E), total cholesterol(TC), triglyceride(TG),
high density lipoprotein-cholesterol(HDL-C), HDL2-C, HDL3-C,
lipoprotein(a)[Lp(a)], apolipoprotein(Apo) AI and B100 were determined in 201
subjects, among them 102 patients with coronary heart disease(CHD) and 99 healthy
subjects. It was observed that plasma T level was correlated negatively with TG(r
= -0.47, P < 0.01) and Lp(a) (r = -0.163, P < 0.05), and positively with HDL3-C(r
= 0.328, P < 0.01) and Lp(a)(r = -0.163, P < 0.05), and positively with HDL-3(r =
0.328, P < 0.01) and HDL3-C(r = 0.328, P < 0.01). Meanwhile, plasma levels of TG
(1.47 +/- 1.16 mmol.L-1) and Lp(a)(25 +/- 17.8 g.L-1) were significantly higher
in the subjects with low plasma T level (< 270 ng.ml-1) than those in the
subjects with normal plasma T level (1.10 +/- 0.74 mmol.L-1 and 17 +/- 15.9 g.L
1, respectively), while plasma levels of HDL-C (1.31 +/- 0.30 mmol.L-1) and HDL3
C(0.88 +/- 0.22 mmol.L-1) were significantly lower in the former than in the
latter (1.44 +/- 0.33 mmol.L-1 and 1.02 +/- 0.26 mmol.L-1, respectively). The
results support that low plasma T level may be a risk factor for coronary heart
disease, which may relate to the changes of plasma lipoproteins.
PMID- 10681766
TI - [Clinical analysis of PIH with abnormal liver function in 66 patients].
AB - Sixty-six patients of severe pregnancy induced-hypertension(PIH) with abnormal
liver function were studied. The results showed that the incidence of abnormal
liver function in severe PIH was 20.62%, which was significantly higher than that
in moderate PIH and closely related to the course of the disease. The incidence
of abnormal liver function in patients who were sick longer than 1 month was much
higher than those with short course (P < 0.05). The liver function abnormality in
PIH mainly showed the elevation of SGPT activity, increase of serum bilirubin was
rarely seen. Besides these, the incidences of the fetal distress and postpartum
hemorrhage in patients with abnormal liver function were significantly higher as
compared with those having normal liver function (P < 0.05).
PMID- 10681767
TI - [Protective effects of shenmai cardioplegia on intracardiac operative patients
with cardiopulmonary bypass].
AB - Forty intracardiac-operative patients were divided into two groups randomly.
Twenty patients were received by the improved St. Thomas Crystal Blood (1:4)
Cardioplegia(Group A); 20 by the Shenmai liquid and improved St. Thomas Crystal
Blood(1:4) Cardioplegia(Group B). During perioperation, the blood samples and
myocardial tissue were collected, and clinical observations were recorded. The
results showed that in Group B, contents of myocardial specific isoenzyme of
creatine kinase(CK-MB), lactate dehydrogenase(LDH), malonyldialdehyde(MDA), and
myocardial Ca2+ were significantly lower, the contents of superoxide
dismutase(SOD) were, significantly better than that in Group A; and the
histological findings showed less damage in Group B than in Group A. We conclude
that Shenmai Cardioplegia can increase the myocardial protection of the
intracardiac-operative patients. The possible mechanisms are that Shenmai liquids
inhibit the production of oxygen free radicals and calcium paradox.
PMID- 10681769
TI - [The diagnosis and treatment of nipple discharge in 253 cases].
AB - Among 253 cases of nipple discharge, 96 cases of them were diagnosed as
intracanalicular papilloma(37.9%), 73 cases as cystic disease of breast(28.9%),
41 cases as mammary duct ectasia (16.2%), 35 cases as breast cancer(13.8%) and 8
cases as acute suppurative mastitis(3.2%). The masses beneath areolar region were
smaller those outside areola. Finding of cancer cells or suspicious cancer cells
through cytologic examination of nipple discharge smear and breast mass puncture
usually had important significance. In addition, near infrared ray scanning shows
high rate of correct diagnosis; estimation of carcinoembryonic autigen(CEA) in
nipple discharge is beneficial to the early diagnosis of malignant diseases.
PMID- 10681768
TI - [The second phase clinical observation of anti-radiation effect by superoxide
dismutase].
AB - Multiple center randomized controlled double blind clinical trait was conducted
to evaluate the anti-radiotherapy effect by SOD (produced by Hunan Biochemical
Work) in 159 patients. Injection of 4000U SOD immediately after receiving
radiotherapy significantly reduced the occurrence rate of skin, oral mucosal,
pelvic visceral and systematic adverse reaction, only the reduction of leukopenia
did not reach the statistical significant level. No adverse effect of SOD
injection was observed. The results suggest that SOD is a safe and effective
agent to attenuate the radiotherapy reactions.
PMID- 10681770
TI - [Detection of 17-ketosteroid and 17-hydroxycorticosteroid in urine after
separation and collection by foam rubber].
AB - Using foam rubber 17-ketosteroid (17-KS) and 17-hydroxycorticosteroid (17-OHCS)
were separated and collected in urine. 17-KS and 17-OHCS were eluted down from
the foam rubber with alcohol, colour reaction can be respectively produced by m
dinitrobenzene and phenyhydrazine hydrocholoride, then both of them were detected
by spectro-photometry. The standard deviation of this method was +/- 0.032, and
its minimum detectable concentration was 0.01 microgram.ml-1. The recovery rate
of 17-KS and 17-OHCS estimation was from 99.0% to 101.0%, with co-efficients of
variation less than 6.23%.
PMID- 10681771
TI - [Determination of glycosylated hemoglobin in human erythrocytes by fast protein
liquid chromatography system].
AB - The chromatography method for analysis of glycosylated hemoglobin(HbA1c) in human
erythocytes was established by using a fast protein liquid chromatography
system(FPLC) and a Mono S column. The average intrabatch and interbatch
coefficients of variations (n = 3) were 2.5% and 4.8%, respectively. There was a
positive correlation between the results of FPLC and routine microcolumn method
(r = 0.413, P < 0.02). Using FPLC method, the HbA1c levels in festing blood of 54
normal donors and 26 diabetics on admission were 4.6 +/- 1.19(%) and 10.2 +/-
3.45(%), respectively. A significant difference was found statistically between
the results of two groups (t = 10.8, P < 0.01).
PMID- 10681772
TI - [Effect of ultraviolet irradiation on immune function in rabbits].
PMID- 10681773
TI - [Analysis of risk factors, prevention and therapy of fungal infection on brain
injuries].
PMID- 10681774
TI - [Effects of sevoflurane on hemodynamics of open heart valve replacement surgery].
PMID- 10681775
TI - [Relation between spirochetes and retrograde pulpitis].
PMID- 10681776
TI - [Relation between ABO blood-group system and Helicobacter pylori infection].
PMID- 10681777
TI - [Clinical uses of autologous blood transfusion].
PMID- 10681778
TI - [Mitral valve prosthesis implantation complication: thrombosis].
PMID- 10681779
TI - [Ultrasonic diagnosis for orthopedic (corrective) transposition of the great
artery with complex cardiac deformity. A case report].
PMID- 10681780
TI - [Expression of connexin genes in the liver of different stages of embryo
development].
AB - To explore the relationship between the connexin (Cx) gene expression and
cellular differentiation in the liver of different embryonic stage, we studied
the expression of Cx genes in the liver of different embryonic ages by Northern
blot hybridization technique, using the series of Cx gene as the molecular
probes. The expression of Cx genes exhibited organ specificity, Cx26, Cx32, and
Cx43 were expressed in the liver while others had no signal. Cx26, Cx32, and Cx43
genes exhibited different expression models in different developmental stages of
the fetus. Cx43 did not express in human liver after birth, but it expressed in
the fetal stage. The results suggest that the expression of Cx genes plays an
important role in the organ development and may be a key gene to regulate some
differentiational events associated with cell growth and organ development.
PMID- 10681781
TI - [Expression of CD44V6 and nm23-H1 in thyroid papillary adenocarcinoma and lymph
node metastasis].
AB - Expression of CD44V6 and nm23-H1 in thyroid papillary adenocarcinoma (TPC) was
studied in 84 patients by immunohistochemistry. The positive rates of CD44V6 and
nm23-H1 were 63.1% and 48.8% respectively. An increased CD44V6 and a decreased
nm23-H1 positive rate in patients with lymph node metastasis (LNM) were observed
(P < 0.01). Negative correlation was existed between overexpression of CD44V6 and
low-expression of nm23-H1 (P < 0.01). The results suggested that CD44V6 and nm23
H1 play important role in LNM of TPC and disordered expression of CD44V6 and nm23
H1 are involved in the process of LNM.
PMID- 10681782
TI - [Effects of mild hypothermia on Na(+)-K+ ATPase and lipid peroxidation in canine
brain tissue following cardiac arrest and resuscitation].
AB - The effect of mild hypothermia on Na(+)-K+ ATPase and lipid peroxidation in
canine brain tissue following a 18-minute cardiac arrest and resuscitation for 8
hours were studied. Mild hypothermia improved the restoration of the activity of
Na(+)-K+ ATPase, LDH, protect the activity of SOD, decrease the loss of GSH, but
not completely blocked the ischemia reperfusion induced lipid peroxidation.
PMID- 10681783
TI - [Microtubule-associated protein30 (MAP30) and ubiquitin detected in
neurofibrillary tangles of Alzheimer's disease brains].
AB - Using immunohistochemical technique, the distribution of immunoreactive products
of antiubiquitin and MAP30 in the neurons of hippocampus of Alzheimer's disease
(AD) brain were studied. Nurofibrillary tangles (NFT), dystrophic neurites in
plaques and neuropil threads were labeled by the antibody of ubiquitin. NFT and
pretangle neurons (PTN) were stained by the antibody of MAP30, but not detectable
signal in axons or distal dendrites. The neurons immunostained with antibodies to
ubiquitin and MAP30 were found in all the areas of CA1, CA2, CA3 and CA4 of
hippocampus of AD. These neurons labeled by 2 antibodies used in this study were
distributed more in the CA1 and CA2 than those in CA3 and CA4. The results
indicate that ubiquitin is seen associated when NFT is already formed, and MAP30
may be a novel antigenic component of NFT in Alzheimer's disease.
PMID- 10681784
TI - [Protection of hypertonic saline/mannitol to thymic cell apoptosis induced by
endotoxin (LPS) in mice].
AB - To observe the effect of HSM (hypertonic saline/mannitol) on thymic cell
apoptosis induced by endotoxin (LPS) in mice, twenty-four mice were divided into
three groups (8 mice/each group): 1. Control group, each mouse was
intraperitonealy injected with normal saline; 2. LPS group, each mouse was
intraperitonealy injected with LPS; 3. LPS + HSM group, each mouse was
intraperitonealy injected with HSM before and after injection of LPS. The results
showed that the percentage of apoptosis of HSM + LPS group was lower than that of
LPS group (P < 0.01); the ladder of nucleosomal DNA fragments by agarose gel
eletrophoresis of HSM group was not typical as compared with that of LPS group.
It is suggested that HSM might protect the apoptosis of mouse thymic cell induced
by LPS and may improve the immune function.
PMID- 10681785
TI - [The expressions of p16, CDK4 and PCNA proteins in trophoblastic tumors].
AB - OBJECTIVE: To evaluate the relationship between the regulatory factors in G1
phase of cell cycle and the cacrinogenesis of the trophoblastic cells. METHODS:
The expressions of p16, cyclin-dependent kinase 4 (CDK4), proliferation cell
nuclear antigen (PCNA) proteins in 18 cases of trophoblastic tumors, 30 cases of
hydatidiform mole and 30 cases of normal villi were studied by
immunohistochemical methods. RESULTS: The expressions of p16 protein between
malignant trophoblastic tumors and normal villi were significantly different (P <
0.05). PCNA positive rate in p16 positive samples were markedly lower than that
in negative samples (P < 0.05). The expressions of CDK4 among normal villi,
hydatiform mole and trophoblastic tumors were not significantly different.
Patients with positive p16 expression had a higher 3 year survival rate.
CONCLUSION: p16 protein may inhibit trophoblastic cells proliferation, and p16
gene mutation may be an important factor in carcinogenesis of trophoblastic cells
and proliferation out of control. P16 protein expression examination is helpful
in prediction of patients prognosis.
PMID- 10681786
TI - [Determination of cyanide in whole blood by completely differential
spectrophotometry].
AB - This paper introduced a method for the determination of cyanide in whole blood by
completely differential spectrophotometry with pyridine-pyrazolone method after
stabilization by addition of silver sulfate and separation by distillation. The
analytical results showed a precision 5.4% (n = 6) for the determination of 0.068
microgram.ml-1 CN- in whole blood. The average recovery was 97.4%. This method
was successfully used for the determination of cyanide in whole blood of non
smokers and smokers.
PMID- 10681787
TI - [Four-year follow-up and molecular epidemiologic investigation of intrafamilial
transmission of HCV infection].
AB - OBJECTIVE: To study the intrafamilial transmission of HCV infection. METHODS:
Four-year follow-up and molecular epidemiologic investigation of HCV infection in
a village was carried out. The diversity of HCV core region was analysed by
reverse transcription nested polymerase chain reaction, Okamoto genotyping
method, and single strand conformation polymorphism analysis (SSCP). RESULTS: The
incidence of positivity of anti-HCV and -HCVRNA raised from 21.30% (75/352) to
43.18% (152/352). There were 42 families with two or more members serological
positive for anti-HCV and/or -HCVRNA. There were a 3.46-fold increase of
intrafamilial propagation of HCV infection in the past 4 years. HCV genotyping by
Okamoto method showed that 90.67% (136/150) belonged to Type 1b/II, two cases
(1.33%) belong to type 2a/III and three cases (2.00%) were co-infection of both
types. Comparison of SSCP patterns revealed that the SSCP of HCV cDNA was
identical among members of the same family, but the single strand conformation of
HCV cDNA exhibited polymorphism patterns in different families. CONCLUSION: The
results indicate that the cause of marked increase of HCV infection rate in this
village in a 4-year period is mainly because of intrafamilial propagation. SSCP
is more feasible for molecular epidemiologic investigation of HCV infection than
genotyping.
PMID- 10681788
TI - [Thiamine status of university teacher families in Changsha].
AB - To evaluate the thiamine status of the population consuming the refined cereals
and its products, we studied thiamine concentration in 23 food samples and human
urine, and three-day dietary survey was conducted. The results showed that the
thiamine content in the staple food was much lower than that in the raw material.
The thiamine intake from diet was below to 80% RDA in 42.8% investigated families
and the thiamine energy ratio was lower than 0.5 mg/4186.8 kJ in 71.5% of them.
For the ratio of urinary tiamine (mg)/urinary inosine (g), 51.3% subjects
exhibited decreased excretion, especially in the school-age children. We conclude
that those people who take the refined cereals and its products as a staple food,
is in the risk of thiamine deficiency.
PMID- 10681789
TI - [Study on the characteristics of personality, emotion and the plasma arginine
vasopressin levels in patients with Gan Yang Shang Kang Zheng].
AB - Eighty patients with Gan Yang Shang Kang Zheng (GYSKZ) and the related Zheng were
questioned with three psychological scales: Type A Behavior Inventory, STAI and
SDS and plasma AVP (arginine ressopressin) levels were determined by RIA. The
TAB, S-AI, T-AI scores and plasma AVP levels of the patients with GYSKZ increased
consistently and the changes of all parameters in different diseases in the same
Zheng were similar. The results suggest that in patients with GYSKZ, type A
behavior is the dominant personality and anxiety is the chief emotional disorder.
Patients with GYSKZ are in the state of high level of psychological stress.
Patients with GYSKZ and GHSYZ have some common pathophysiological basis.
PMID- 10681790
TI - [Measurement of the strength of pronation and supination forces and its
significance in radius fracture displacement].
AB - The strength of pronation and supination was measured by "Forearm-Rotate
Dynamometer" on 524 male and female students ranging in age from 16 to 32. The
study showed that the strength of supination was 13% greater than that of
pronation for 91.3% of all the tested subjects (1048 sides). Based on this
finding, the pattern of displacement fracture of the middle lower segment of the
radius was discussed. It was concluded that the proximal fragment displacement
will show supination, adduction and flexion when a proximal fragment displacement
occurs.
PMID- 10681791
TI - [Experimental study on hypoglycemic effect of YTY granules].
AB - OBJECT: To perform experimental pharmacodynamic evaluation of a new TCM
antidiabetic drug Yitangyin (YTY). METHODS: Experimkental streptozotocin induced
rat diabetes models were subjected YTY treatment and the hypoglycemic effect was
evaluated. The proved TCM Yusanxiao (YSX) was used as contrast. RESULTS: The low,
middle and high dose YTY groups exhibited significant hypoglycemic effects on the
model rats. The efficiency was comparable with YSX. CONCLUSION: The TCM YTY
granule is an effective hypoglycmeic agent.
PMID- 10681792
TI - [The protective effects of cardiac ischemic preconditioning on lung in cardiac
operation with cardiopulmonary bypass].
AB - Twenty direct vision intracardial operation patients were divided into two groups
randomly. After cardiopulmonary bypass, ten patients were treated with myocardial
ischemic preconditioning. The aorta were clamped for 3 minutes and released for 3
minutes (Group IP). Another ten patients were not treated with ischemic
preconditioning (Group C), only underwent 6 minutes cardiopulmonary bypass. Then
the aorta were clamped and intracardial operation were done. The left atrium
blood and lung tissue were collected just after thoractomy and half an hour after
cardiac reperfusion in both groups. RESULTS: (1) The numbers of polymorphonuclear
(PMN) of the two groups were increased significantly after cardiopulmonary bypass
(P < 0.01). (2) The number of PMN and SOD, PaO2 contents were significantly
higher in Group IP than in Group C (P < 0.05). (3) The numbers of PMN in lung
interstitum under microscopy were less in Group IP than in Group C. (4) MDA
contents were less in Group IP than in Group C (P < 0.05). (5) Histological
finding showed less damage in Group IP than in Group C. It is evident that
cardiac ischemic preconditioning could protect lung against ischemia reperfusion
injury. The possible mechanisms are that ischemic preconditioning inhibites the
accumulation and activation of PMN in lung tissue and reduces the production of
oxygen free radicals.
PMID- 10681793
TI - [Changes of blood lipids and apolipoproteins in patients with silent myocardial
ischemia].
AB - Serum lipid profiles and apolipoproteins were measured in 148 patients with
silent myocardial ischemia (SMI) and 30 healthy control subjects comparable in
age. The serum lipid profiles and apolipoproteins were abnormal in all types of
SMI which were more significant in type II and III. The extent of ST segment
depression in ECG were positively correlated with serum TG, TC, LDL, B100,
B100/A1, Lp(a); and negatively correlated with A1, HDL1, HDL2, HDL-C/TC. Multiple
factor stepwise regression analysis revealed that the increased concentration of
serum TG, LDL, and B100/A1 ratio and decrease of HDL2-C are independent risk
factors in SMI.
PMID- 10681794
TI - [Comparative study of left ventricular morphology and function of patients with
left ventricular systolic and diastolic heart failure on echocardiography].
AB - Left ventricular pathology and pathophysiological characteristics of fifty
patients with left ventricular diastolic heart failure (LVDHF), and 35 patients
with left ventricular systolic heart failure (LVSHF) diagnosed by clinical
manifestations and radionuclide ventriculography, were examined by
echocardiography and 20 healthy persons were served as control group. Left atrial
diameter (LAD), interventricular septum thickness (IVST) and posterior wall
thickness (PWT) and left ventricular mass index (LVMI) were significantly
increased in the patients with LVDHF, while left ventricular diameter (LVD) was
significantly increased in the patients with LVSHF. Left ventricular ejection
fraction (LVEF), cardiac index (CI) were significantly decreased in the patients
with LVSHF. Early peak filling velocity (EPFV), atiral peak filling velocity
(APFV), deceleration of early peak filling velocity (DC) and isovolumic
relaxation time (IRT) in the patients with LVDHF and LVSHF observed no
significant difference.
PMID- 10681795
TI - [Clinical study on left ventricular diastolic heart failure in the aged
patients].
AB - Forty aged patients with LVDHF and 30 with left ventricular systolic heart
failure (LVSHF), confirmed by radionuclide ventriculography were studied by
clinical, echocardiography and treadmill test. Twenty healthy aged persons were
served as control group. Compared with LVSHF, short duration and less severe
manifestations of heart failure in LVDHF were observed. Compared with the
control, left atrium was enlarged but not the left ventricular chamber, and LV
wall was thickened in LVDHF, while enlargement of LV chamber was only found in
LVSHF. However, LV systolic function was remained normal in LVDHF. The exercise
tolerance was decreased in both LVDHF and LVSHF groups, but more marked in LVSHF.
PMID- 10681796
TI - [Changes of plasma testosterone level in male patients with coronary heart
disease].
AB - The plasma testosterone (T), estrodiol (E), total cholesterol (TC), triglyceride
(TG), high density lipoprotein cholesterol (HDL-C), HDL2-C, HDL3-C,
apolipoprotein (apo) A1 and B100, and lipoprotein (a) [Lp(a)] were measured in
118 male patients with coronary heart disease (CHD) and 53 sex and age-matched
healthy controls. The results showed that plasma T, HDL-C, HDL3-C levels and HDL
C/TC ratio were significantly lower and Lp(a) level was significantly higher in
patients than in the controls. After adjusting body mass index, blood pressure
and fasting blood glucose, the difference of plasma level between patients and
controls persisted. Plasma T level correlated positively with the HDL-C, HDL3-C
level and HDL-C/TC ratio and negatively with systolic blood pressure, apoB100 and
Lp(a) level. Logistic regression was used to analyze the data, and this indicated
that decreased T and HDL3-C levels, and increased Lp(a) level were the
independent risk factors of CHD.
PMID- 10681797
TI - [The application of low tidal volume pressure-controlled ventilation in patients
with acute respiratory distress syndrome].
AB - Low tidal volume pressure-controlled ventilation therapy was used in 32 patients
with ARDS. There were resulted a lower peak inspiratory pressure (PIP) level than
that of control group, thus a decline in incidence of overventilation and the
overventilation induced mortality. The results suggest that low tidal volume
pressure-controlled ventilation may consider as preferred ventilation mortality
in management of ARDS.
PMID- 10681798
TI - [Prospective study on the correlation factors of fetal macrosomia].
AB - The increase of body weight in pregnancy women, 50 g oral glucose challenge test
(50 g GCT), pregnant women and umbilicus vein blood insulin (INS), growth hormone
(GH), glucose and neonate weight were measured in 110 pregnant women and their
neonates were measured to explore the correlation factors of fetal macrosomia.
The incidence of macrosomia was higher in pregnant women whose increased weight >
or = 15 kg than those < 15 kg. 50 g GCT plasma glucose showed positive
correlation with neonatal weight. Which was higher in the group of the fetal
macrosomia than of the normal neonates. The results suggest that both the
increasing weight of the pregnant women and the 50 g GCT are related parameters
to predict fetal macrosomia. To prevent fetal macrosomia the diet should be
limited in those who have had a high increasing body weight in pregnancy and
appropriate intervention is required to those whose 50 g GCT are positive.
PMID- 10681799
TI - [Detection of Toxoplasma gondii DNA in the autopsy cases of abnormal birth and
teratosis by polymerase chain reaction].
AB - Toxoplasma gondii DNA in the autopsy tissues of 72 cases of the premature,
stillbirth and congenital malformation was detected using polymerase chain
reaction (PCR). The specific amplified products were found in 9 cases, i.e. one
case of premature, 3 cases of stillbirth, one case of hydrocephalus and 4 cases
of other teratosis. The positive rate was 12.5%. Ten control samples were
negative. The results showed that Toxoplasma gondii infection was present in the
disease cases. The finding indicates that the infection of Toxoplasma gondii may
be one of the main causes of the abnormal birth and the congenital teratosis.
PMID- 10681800
TI - [Internal fixation with mini-titanium plate for midface fractures].
AB - Thirty four patients with midface bone fractures were fixed by rigid internal
fixation (RIF) with min-titanium plate. An optimum exposure is provided for the
fracture sites of zygomatic, zygomatic arch, orbital floor and maxilla with the
coronal incision and adjuvant incisions. The approach was of benefit to accurate
anatomic reduction and fixation of the fracture segments. RIF with min-titanium
plate provided three-dimensional stability. The fixation of zygomatic-frontal
crevice and zygomatic maxillary crevice were the key for obtaining sufficient
stability, and at least two fixation screws were required above zygomatic-frontal
crevice.
PMID- 10681801
TI - [Research in the relationship between Chlamydia and ureaplasma and infertility].
AB - Samples taken from cervix and male urethra of 768 infertilitas patients were
studied, and samples taken from 226 normal fertile males and females served as
control. The fluorescent monoclonal antibody technique and cell culture method
were used for Chlamydia trachomatis (Ct) and microbiological culture method was
used for Ureaplasma urealyticum (Uu) detection. The positive rates of Ct and Uu
infections were 28.64% (220/768) and 36.59% (281/768) in infertilitas group, 5.2%
(14/266) and 14.28% (38/266) in control group respectively. There was significant
difference between the 2 groups (P < 0.01). The results suggest that infection
with Ct or Uu is one of the factors causing infertility.
PMID- 10681802
TI - [Etiology and clinical analysis of epididymal mass].
AB - The etiology and clinical pathological analysis of 147 cases of epididymal mass
were presented. The result showed that the most common mass in inflammatory
(66%), and the majority was tuberculosis, the next was cystic diseases (30%).
However, neoplasm was relatively less and malignant mass was rare. The diagnosis
can be established by careful history, physical examination, and BUS. The
selective surgery depends on the nature of diseases, the demand of the patients
and the effect of conservative therapy.
PMID- 10681803
TI - [Relationship between clinical manifestation and pathology in pediatric renal
diseases].
AB - To elevate the clinical diagnosis and pathological compatibility of pediatric
kidney diseases. Pathological changes from 101 cases of pediatric renal diseases
were studied, covering 13 diseases entities, including glomerulo-nephritis,
simple nephrotic syndrome, nephritic nephrotic syndrome etc. The technique of tru
cut biopsy under the guidance of B ultrasonogram was used in renal biopsy. The
renal puncture biopsy was 100% satisfactory. Pathological changes involved 12
pathological types. MsPGN were the most commonly seen (39.6%), followed by MPGN
and ICPGN (12.87% and 10.89%) respectively. It was found that children with
similar clinical manifestation may possess different pathological changes, while
the same pathological entity may present multiple clinical manifestation. The
results suggest that renal biopsy pathological diagnosis is important in the
diagnosis, treatment and prediction of prognosis in pediatric renal disease.
PMID- 10681804
TI - [Preliminary study on Chlamydia pneumoniae pneumonia].
AB - In order to know the incidence of Chlamydia pneumoniae (strain TWAR) pneumonia
and its clinical features, 93 patients with pneumonia and 93 matched patients
with non-respiratory diseases were studied. TWAR antibodies (IgG and IgM) were
detected by microimmunofluorescence (MIF) test. The results showed that 19.4% (18
cases) patients with pneumonia were TWAR pneumonia, in which 10 cases accompanied
by bacteria infection and 7 cases being simple TWAR pneumonia. There were no
significant differences in clinical features between TWAR pneumonia and non-TWAR
pneumonia, except dry and moist rales. These data showed that the occurrence
percentage of TWAR pneumonia in patients with lung cancer was higher than that in
patients with the other respiratory diseases. This study suggests that there are
TWAR pneumonia in China.
PMID- 10681805
TI - [Ultrasonographic rating score in evaluation of pathological severity and timing
of operation for acute cholecystitis].
AB - A rating score of ultrasonography to evaluate the pathological severity and
timing of operative intervention of acute cholecystitis was designed. The
ultrasonic rating score consisted of 7 items with were sensitive and specific in
diagnosis of acute cholecystitis, accorded with the findings during operation.
Emergency cholecystomies performed on patients with score < or = 10, 11-18 and >
18 points were 1/30, 4/42 and 7/13 respectively, followed by definite procedures.
The results suggest that the ultrasonographic rating score is an useful approach
in ultrasound diagnoses and timing of operation for acute cholecystitis.
PMID- 10681806
TI - [Distribution of Mg2+ and Ca2+ in serum and lymphocyte of the patients with
arrhythmia].
AB - The distributions of Mg2+ and Ca2+ in serum and lymphocyte from 51 arrhythmic
patients (15 cases of atrial premature beat, 12 cases of atrial fibrillation, 24
cases of ventricular premature beat) and 30 healthy subjects were detected by
flame atomic absorption spectrophotometry. The results showed that the
distribution of Mg2+ of the arrhythmia cases was significantly lower than that of
the control group (P < 0.01) and the concentration of Ca2+ in lymphocytes of
arrhythmia case group was significantly higher than that of the control group (P
< 0.01). The above distribution of Mg2+ and Ca2+ was somewhat related to the
degree of heart failure. It is suggested that the lower distribution of Mg2+ in
lymphocytes may cause arrhythmias.
PMID- 10681807
TI - [A clinical analysis of 94 cases of recurrent stroke].
AB - Ninety-four cases of recurrent stroke were analyzed retrospectively, and 290
cases of first stroke episode were selected as controls. Results showed that
recurrent stroke mainly appeared within the first year after the initial episode
males predominant. The clinical manifestations of recurrent stroke were variable
and commonly more severe. No significant differences was observed between the
groups with respect to a variety of factors including the presence of
hypertension, diabetes, history of transient ischemic attack, or familial history
of stroke, cardiac attacks, cigarette smoking and/or alcohol consumption. The
risk factors for recurrent stroke were discussed.
PMID- 10681808
TI - [Effects of lotensin and nitrendipine on plasma fibrinogen and platelet
aggregation in hypertensive patients].
AB - Plasma fibrinogen and platelet aggregation were measured by turbidimetric
immunoassay, turbidimetry in 47 hypertensive patients and 20 normotensive control
subjects. Among the 47 hypertensives, 24 cases were received lotensin and 23
nitrendipine. The plasma fibrinogen was increased and platelet aggregation
enhanced in hypertensive patients before treatment. Platelet aggregation
decreased after 8 weeks of treatment with lotensin or nitrendipine respectively.
Lotensin decreased plasma fibrinogen whereas nitrendipine did not. It was
concluded that both lotensin and nitrendipine decreased platelet aggregation;
lotensin decreased plasma fibrinogen but nitrendipine did not.
PMID- 10681809
TI - [Effects of lentinan of peripheral blood mononuclear cell expression of
interleukin-2 receptor in patients with chronic hepatitis B in vivo and in
vitro].
AB - The effects of lentinan on peripheral blood mononuclear cell (PBMC) expression of
IL-2 receptor in patients with chronic hepatitis B in vitro and in vivo were
studied. The expression percentage of IL-2 receptor in 44 patients with chronic
hepatitis before treatment was 36.74 +/- 7.74, which was lower than healthy
subjects, and was 48.92 +/- 3.79 after 2 months treatment of lentinan, which was
approximated the normal control. PBMC from 30 patients with chronic hepatitis B
were cultured in vitro with or without lentinan. The percentage of expression IL
2 receptor was 12.81 +/- 2.62 without lentinan and was 35.70 +/- 4.87 in the
presence of lentinan. The concentration of lentinan stimulating expression of IL
2 receptor was between 0.2 to 200 g.ml-1. The results suggest that lentinan
stimulates expression of IL-2 receptor on PBMC, which is associated with the
therapeutic effectiveness of lentinan treatment.
PMID- 10681810
TI - [Serum type IV collagen and laminin in patients with chronic hepatitis and its
clinical significance].
AB - Serum levels of laminin and type IV collagen of 188 patients with different types
of viral hepatitis were determined by RIA. Thirty-five blood donors were served
as normal control. The results showed that: (1) higher levels of type IV collagen
was found in patients with severe chronic hepatitis, post-hepatitis cirrhosis or
subfulminant hepatitis; (2) the level of laminin was obviously increased in post
hepatitis cirrhosis and subfulminant hepatitis; (3) there was a positive
correlation between the levels of type IV collagen and laminin as well as gamma
globulin, and negatively correlated to serum albumin, no correlation with alanine
aminotransferase was observed; (4) detecting rate of hepatic fibrosis was
increased with combination of serum laminin and type IV collagen examination; (5)
serum type IV collagen was more sensitive than that of serum laminin. The results
suggest that determination of serum type IV collagen and laminin are useful in
diagnosis of hepatic fibrosis, and combination of the two parameters is
recommended.
PMID- 10681811
TI - [The clinic significance of serum hyaluronate and tumor necrosis factor alpha
levels in liver diseases].
AB - Serum levels of hyaluronic acid (HA) and tumor necrosis factor alpha (TNF alpha)
in 94 patients with various liver diseases and 31 healthy controls were studied
by RIA, Serum TNF alpha in hepatitis, liver cirrhosis (LC) and primary hepatic
carcinoma (PHC) was higher than that of the control. Serum HA in chronic
hepatitis, LC and PHC was higher than that in the control. The serum level of HA
showed a positive correlation with the serum level of TNF alpha. It is considered
that the increase of serum HA indicates an early fibrogenic tendency in patients
with liver diseases. TNF alpha is involved in the formation of hepatic fibrosis.
PMID- 10681812
TI - [Domperidone and hyperprolactinemia].
AB - Nine patients with hyperprolactinemia and one patient with pituitary microadenona
were observed for 6 years. They were induced by administration of domperidone.
The clinical characteristic of the 9 patients was summarized and analysed. The
results suggest that prescribe domperidone for fertile women should pay more
attention to its adverse effect on inducing hyperprolactinemia and even pituitary
microadenona.
PMID- 10681813
TI - [The relationship between immunosuppression and oxygen free radicals in burned
patients].
AB - The serum immunosuppression effect and its relation to oxygen free radicals were
studied in patients with thermal injury (n = 11, total body surface area 20%
83%). The serum MDA, sIL-2R increased significantly in burned patients (P < 0.01
all). The serum of burned patients depressed the IL-2 productin of normal human
PBMC (P < 0.01). Antioxidants decreased the serum sIL-2R in burned patients and
attenuated the suppressive effect IL-2 production of normal human PBMC (P < 0.05
all). The results suggest that oxygen free radicals participate in the serum
immunosuppression effect in burned patients.
PMID- 10681814
TI - [A preliminary study of plasma oxidase activity by spectrophotometry on the
healthy middle-aged and old volunteers in Changsha].
AB - The plasma oxidase activities (POA) in 26 healthy volunteers were determined by
spectrophotometry. The results showed that the POA value of the 26 cases was
obviously lower (78.90 +/- 8.12 U.L-1) than that in Lasla's (84 +/- 5 U.L-1) (P <
0.05). A preliminary normal reference range of POA (45-60 years old) in Changsha
was established. This method is an accurate (CV = 3.9%), cheaper, and easy one
and applicable for clinical laboratories.
PMID- 10681815
TI - [Pathology and etiology of pulmonary alveolar proteinosis].
PMID- 10681816
TI - [Relation between plasma calcium and lipids in coronary disease].
PMID- 10681817
TI - [Relation between abnormal histogram and automatic blood platelet count].
PMID- 10681818
TI - [Skull damage caused by malignant changes of scalp cicatrix. A case report with
radionuclide image].
PMID- 10681819
TI - [Application of microdissection, PCR, and microcloning technique on human
chromosomal study].
PMID- 10681820
TI - [Study on relationship between apoptosis and proliferation of cells in liver
cirrhosis and hepatocellular carcinoma].
AB - Apoptosis and nuclear antigen of proliferating cells were detected by labelling
technique of in situ terminal deoxynucleotide transferase and immunohistochemical
method in liver cirrhosis and hepatocellular carcinoma(HCC). The density of
apoptotic cells in HCC was significantly lower than that in cirrhosis, and the
density of proliferating cells was much higher in HCC than that in cirrhosis.
Apoptotic cells mainly distributed in the peripseudolobular region of cirrhosis
and formed an apoptosis zone. But they scattered within the cancer tissue. The
results suggest that the formation of apoptosis zone in cirrhosis may be related
to the change of liver blood stream. Selective proliferation of cells may exist
during carcinogenesis of liver cirrhosis.
PMID- 10681821
TI - [The effect of brain-derived neurotrophic factor on the rat electroretinography
after pressure-induced ischemic injury].
AB - Brain-derived neurotrophic factor (BDNF) or normal goat serum (NGS) was injected
intravitreously in each 11 wistar albino rats two days before the induction of
ischemia. Retinal ischemia was induced in 22 rats by increasing intraocular
pressure to the threshold level which extinguished the electroretinography (ERG)
b-wave individually, and maintaining for 90 minutes. The ERG b-wave of the BDNF
treated rats recovered to 80.5 +/- 24.4% of their normal amplitude three days
after ischemia, while that of the NGS-treated rats recovered only to 11.1 +/-
5.3%. Statistic analysis showed that the recovery level of ERG b-wave after
ischemia in the BDNF and NGS treated rats was significantly different (P < 0.01).
The results suggest that BDNF could promote the recovery of the retinal
electrophysiologic function from ischemia induced by high intraocular pressure.
PMID- 10681822
TI - [Drug resistance study and detection of methicillin-resistant staphylococci].
AB - MRSA and MRSE were identified by detecting oxacillin resistance of 107 strains of
staphylococci from clinical sources. The positive rates of MRSA were 45.2% and
16.9%, respectively among the whole number of staphylococci examined. Antibiotic
resistant strains were detected with disks by Kirby-Bauer method. All MRSA and
MRSE strains were multi-resistant. Resistant rates of MRSA and MRSE were higher
than MSSA and MSSE. The positive rates of beta lactamase producing in MRSA and
MRSE were significantly higher than MSSA and MSSE (P< 0.05 and P< 0.01)
respectively. These results indicated that MRSA and MRSE were the main pathogens
in the clinical infection. MRSA and MRSE detection are important for the early
diagnosis and treatment of patients with infective diseases.
PMID- 10681823
TI - [Expression and significance of p53, c-erbB2, CEA proteins in colorectal adenoma
and carcinoma].
AB - Expression of p53, c-erB2, CEA proteins in 15 cases of normal colorectal mucosa,
40 adenoma and 40 carcinoma of colon were studied with immunohistochemistry. The
positive rate of p53, c-erbB2, CEA in colorectal carcinomas were significantly
higher than those in adenoma. The positive rate of p53 in adenoma with severe
atypical hyperplasia was higher than that in the mild (P< 0.01), and was higher
in colorectal carcinomas of poor differentiation that that in the well
differentiated ones (P< 0.05). The novel type monoclonal antibody of CEA Col-1
had a high sensitivity and specificity for the tissue of colorectal carcinoma in
which the positive rate was 85%. The results suggested the alteration p53, c
erbB2 are involve in the tumorgenesis and development of colorectal carcinoma;
and detection of p53, c-erbB2 and CEA proteins are helpful in distinguishing
benign and malignant polyps of colon.
PMID- 10681824
TI - [Study on the effects of hyaluronic acid-streptomycin perfusion through the round
window on the function and morphology in guinea pig inner ears].
AB - To investigate the effects of the hyaluronic acid-streptomycin (HA-SM) perfusion
through round window on the function and morphology of the inner ear in guinea
pig, membrous labyrinth mapping, temporal bone section after celloidin embedding,
transmission electron microscopy, electrocochlegraphy (ECochG) and
electronystagmography (ENG) were examined. The nystagmus duration induced by
caloric test was obviously reduced in comparison with that of the preoperation
(P< 0.01), while the action potential(AP) by ECochG was not obviously changed.
The sensory cells of estibular organs were severely damaged, while the morphology
of corti's organs were significantly damaged after HA-SM perfusion. The results
suggest that the HA-SM perfusion through the round window may selectively destroy
the vestibular function, whereas the auditory function is not obviously damaged.
PMID- 10681825
TI - [Effects of dibutyl phthalate on the proliferation and apoptosis of leukemic
cells].
AB - This study was designed to investigate the effects of dibutyl phthalate (DBP) on
the proliferation and apoptosis of leukemic cells. The results showed that DBP
suppressed the proliferation of HL-60 and K562 leukemic cells in a dose-dependent
and time-dependent manner. Inducing HL-60 and K562 leukemic cells to die via
apoptosis were confirmed by that the percentage of the apoptotic cells in
morphology and of the DNA fragmentation increased significantly and that typical
ladders of apoptosis were shown by gel electrophoresis when HL-60 and K562 cells
were exposed to the DBP. Also, K562 leukemic cells was less susceptible to the
DBP than HL-60 cells. These results indicate that DBP can inhibit the
proliferation of HL-60 and K562 leukemic cells and induced them to die via
apoptosis.
PMID- 10681826
TI - [A comparative study on the risk factors for the incidence of tongue cancer].
AB - The risk factors for the incidence of tongue cancer were analyzed with case
study. The result showed that oral leukoplakia (OR = 8.50) residual roots of oral
teeth (OR = 8.50), eating hot foods (OR = 13.0) and eating fire-roasted foods (OR
= 3.5) were the main risk factors for the occurrence of tongue cancer. Eating
fresh fruits (OR = 0.01) was usually helpful to the decrease in the
predisposition of tongue cancer. It suggested that oral precancerous lesions and
mouth diseases should be cured early and good life behavior must be developed in
order to prevent the incidence of tongue cancer.
PMID- 10681827
TI - [Effect of dietary intake on body mass index in middle aged and elderly
population].
AB - The paper investigated and analyzed the relationship between the nutrient intake
and body mass index (BMI) of 200 middle-aged and elderly people(aged 35 - 74
years) in Changsha. The result showed that the constituent rate of underweight
(BMI< 18.5) was 6.5% and that of over-weight (BMI<25.0) was 23.5%. The amount of
fat intake constituted slightly higher proportion in energy intake. The stepwise
regression analysis indicates that the body mass index increases with the
increasing intake of carbohydrates.
PMID- 10681828
TI - [Open heart surgery without cross clamping aorta].
AB - Open heart surgery without cross clamping aorta under normothermic or hypothermic
cardiopulmonary bypass was performed in 167 patients in which there were more
than ten kinds of cardiac diseases. The characteristics of the procedure included
only vena cava blocked and aorta unclamped with beating heart or artificial
evoked ventricular fibrillation. It diminished myocardial ischemia and
reperfusion injuries maximally. There were no low cardiac output syndrome, severe
arrhythmia and complications of brain except two patients died postoperatively.
The operative mortality rate was 1.1% (2/167). The advantages, disadvantages and
safety of this method are discussed briefly in this paper.
PMID- 10681829
TI - [Effect of apolipoprotein E gene plasma levels of lipids, lipoproteins,
apolipoproteins and its relation with coronary heart disease].
AB - Using a technique of polymerase chain reaction-restriction lengths polymorphism
(PCR-RLP), the authors detected the genotypes of apolipoprotein EE(ApoE) in 102
normal control subjects and in 118 patients with coronary heart disease (CHD).
Meanwhile, the effect of ApoE allele on plasma lipid, lipoprotein, apolipoprotein
levels were analyzed, and ApoE allele frequencies of patients with CHD and of
control subjects were compared. The results showed that the technique of modified
PCR-RFLP was a useful measure to detect the genotypes of ApoE. ApoE gene was
polymorphism, resulting in plasma lipid level variance among individuals. As
compared to ApoE3 allele, ApoE4 allele had positive effect on plasma TC, LDL-C
and ApoB100 levels; while ApoE2 allele had negative effect on plasma TC, LDL-C
and ApoB100 levels. The frequency of E4 allele in patients with CHD was higher
than that in control subjects. The results in the present study suggest that
ApoE4 allele is probably the genetic marker of CHD.
PMID- 10681830
TI - [Influence of cardiopulmonary bypass time on gastric intramucosal Pco2 and pH].
AB - To determine the influence of cardiopulmonary bypass time on gastric intramucosal
Pco2 and pH (pHi), 16 patients undergoing cardiopulmonary bypass (CPB) were
divided into two groups according to the CPB time-- group A (n = 8) within 100
minutes and group B (n = 8) beyond 100 minutes. The gastric intramucosal Pco2
increased and the pHi decreased significantly (P< 0.01) at the end CPB compared
with before operation, before bypass and 30 minutes after intermission of CPB in
all patients. Between group B and A, there were significant differences in the
gastric intramucosal Pco2 and in the pHi at the end of CPB. The patients of group
A had no severe complications. In group B, three patients developed life
threatening complications, one of them died. The results indicate that the longer
the CPB time, the greater the degree of gastric mucosal acidosis. It predicts the
patients may develop life-threatening complication after cardiac operations.
PMID- 10681831
TI - [Study on dopamine metabolite in cerebrospinal fluid of schizophrenics and
epilepsics].
AB - The concentration of dopamine (DA) metabolite-homovanillic acid (HVA) in
cerebrospinal fluid (CSF) of 40 patients with schizophrenia 27 with epilepsy and
15 controls without disorders of CNS was reported. The results showed that there
were no significant differences in mean levels of HVA among the three groups. It
is suggested that both schizophrenia and epilepsy are not abnormal in total level
of DA metabolism.
PMID- 10681832
TI - [A study on the activity of nitric oxide in alveolar macrophages from patients
with lung cancer].
AB - Nitrite and nitrate (NO2-/NO2-) in the bronchus alveolar lavage fluid (BALF) and
the supernatants of incubated alveolar macrophages (AMs) from patients with
primary lung cancer were measured by copper-coated cadmium reduction and Griess
method. Mrna expression of AM induced nitric oxide synthase (iNOS) were analyzed
by RT-PCR. There was NO2-/NO2- in BALF either from lung cancer patients or from
control subjects. When compared with control group and the nontumor-bearing lung,
the level of NO2-/NO2-was lower in BALF from the tumor-bearing lung [5.18+/-1.1
vs 2.47+/-0.67nmol x mg protein-1 (P< 0.01); 4.65+/- 2.46 vs 2.47+/- 0.67nmol x
mg protein-1(P< 0.01)]. We also found a lower level of NO2-/NO2- in the
supernatants of incubated AMs from the lung of cancer patients than from control
and nontumor-bearing lung [95.03+/- 21.76 vs 63.37+/- 17.58nmol (P< 0.01);
85.61+/- 16.70 vs 63.37+/- 17.58nmol (P< 0.05)]. No significant difference
existed between the MRNA expression of AM iNOS in lung cancer patients (69%) and
that of control subjects (91%). After the AMs were stimulated with granulocyte
macrophage colony stimulating factor (GM-CSF), the level of NO2-/NO2- in the
supernatants was significantly increased (P< 0.01); while the mRNA expression of
AM iNOS from patients with lung cancer resulted in an increase of 16.85+/- 7.58%
vs 33.38+/- 8.21% of control group (P< 0.05). These observation suggest that some
defects of antitumor function occur in the AMs at the tumor region. GM-CSF can
stimulate AMs and thus potentiate their NO activity.
PMID- 10681833
TI - [Gamma knife treatment of meningiomas].
AB - From October 1995 to July 1997, 52 cases of meningioma were treated with gamma
knife radiosurgery. Twenty-eight cases were followed up by CT or MR. The follow
up period was from 2 to 22 months. Follow-up imaging evaluation showed tumor size
shrinkage in 8 cases, central density decrease in 10 cases, no change in 8 cases
and tumor volume increase in 2 cases. The actual 1-year tumor growth control rate
was 92%. Radiation-induced edema was noted in 9 cases, including 7 cases of the
nonbasal tumor and 2 cases of basal one. The indications and efficacy of gamma
knife treatment of the meningioma were discussed. Our preliminary experience
suggests that gamma knife is an effective and safe technique for carefully
selected patients with meningiomas.
PMID- 10681834
TI - [Clinical significance of pulmonary valvular resistance in children determined by
color Doppler echocardiography].
AB - Pulmonary valvular resistance (PVR) of 40 children with pulmonary valvular
stenosis was determined by color Doppler echocardiography before and after
percutaneous balloon pulmonary valvuloplasty as well as during their follow-up.
The correlation coefficient of PVR between Doppler method and catheterization
method was 0.85 ( P <0.01) and the correlation coefficient between PVR determined
by former method and pulmonary valvular area determined by the latter was -0.80 (
P <0.01). This study indicates that color Doppler echocardiography can take the
place of catheterization to determine PVR in assessing the severity of pulmonary
valvular stenosis in children.
PMID- 10681835
TI - [Bilobate flap applied to the treatment of secondary deformity after
cheiloplasty].
AB - Secondary deformity after cheiloplasty was common and 7 cases (4 males, 3
females) were reconstructed with bilobate flap. The patients' age ranged from 16
to 30. Five of them with single cleftlip. The deformity of them included loose
and shortening of the upperlip, scar, vermilion pitting, too large nostril etc.
Lateral tissue of cleftlip was used to construct the bilobate flap which was
applied to repairing secondary deformity after cheiloplasty. The method was
matched with the principle of anatomy, and the effects were satisfactory.
PMID- 10681836
TI - [Infection of sexually transmitted diseases in female patients with inflammation
of genitourinary tract by polymerase chain reaction].
AB - Using polymerase chain reaction (PCR), Neisseria gonorrhoeae (NG) from 5899
female out-patients with inflammation of genitourinary tract was detected. Among
18.57% positive cases, the effective rates of the gonorrhea (26.07%) and
urethritis (23.73%) were higher than those of the Condyloma acuminatum (CA)
(17.73%), vaginitis (17.70%), and cervicitis (11.54%)(P< 0.01), indicating that
there were various degrees of NG infection in genitourinary tract diseases.
Moreover, Ureaplasma urealyticum (UU), Chlamydia trachomatis (CT), NG, and human
papilloma viruses (HPV) were also detected in 8329 patients with vaginitis. Among
20.01% positive cases, the positive rate of UU was 39.95%, CT 21.36%, NG 17.70%,
and HPV 16.40%. Variance analysis showed that significant differences existed in
the vaginitis caused by different pathogens ( P <0.01); namely, four kinds of
pathogens were present in the patients with vaginitis.
PMID- 10681837
TI - [Clinical analysis of early complications in 132 low body weight infants
performed open-heart surgery].
AB - A clinical analysis of early complications in 132 low body weight infants
undergoing open-heart surgery is reported. There were a higher risk of early
complication associated with severe illness and/or experienced a longer duration
time of cardiopulmonary bypass and endotracheal tube. The total complication rate
was 42.4% and the major three complications were low cardiac output, acute
respiratory distress syndrome and problems from endotracheal tube (occlusion
and/or in proper position of tube). The author emphasized the importance of
management of endotracheal tube after operation.
PMID- 10681838
TI - [CT diagnosis of carcinomas of ovary].
AB - OBJECTIVES: To evaluate CT imaging feature and CT in staging of the ovarian
carcinomas and low malignant potential tumors (LMP) in relation with pathology.
METHODS: Preoperative CT image of of 48 tumors, including 45 carcinomas and 3 LMP
in 30 patients verified surgical-pathologically were analyzed. RESULTS: The
tumors were classified as cystic, predominantly cystic, mixed, predominantly
solid and solid types. The solid and solid portion of the mass were enhanced
obviously. It appeared flower-shaped or nodular shadows or irregularity of patch.
Cystic portion of the mass with a wall or septa thickness exceeding 3mm observed
wall nodularily and/or a solid mass. LMP appeared purely cystic or predominantly
cystic, accompanied with a thin regular wall, thin septa and regular solid
portion with contrast material uptake. CT permitted accurate estimation of the
FiGo in 80% of patients. CONCLUSION: CT images is helpful to explore the
pathologic appearances of neoplasms and biological characteristics of ovary
carcinoma.
PMID- 10681839
TI - [The rescue of iodine allergy by contrast enhanced CT].
AB - We summarized 51 cases of iodine allergy and allergic shock induced by contract
enhanced computed tomography (CT). It is suggested that (1) the appropriate
measures must be taken to prevent the side effects of ionic contrast medium; (2)
a set of first-aid drug and essential equipment must be prepared; (3) the staff
of CT room must be trained with the first-aid techniques and knowledge.
PMID- 10681840
TI - [The value of color Doppler ultrasonography in diagnosing aneurysm].
AB - Using Doppler ultrasound, we detected 59 patients with aneurysm, 54 cases were
confirmed by angiography or operation or both. Among them, 33 cases (63%) showed
true aneurysm, 18 cases (33%) pseudoaneurysm, and 2 cases (4%) superficial
congenital arterio-venous aneurysm. Eight cases were associated with dissected
stripping. One case was falsely diagnosed by ultrasonography. The diagnostic
accuracy was 98%. The results suggest that color Doppler ultrasonography is
useful in detecting aneurysm.
PMID- 10681841
TI - [Effects of monocyte-derived endothelin on acute cerebral infarction].
AB - To investigate the mechanism that monocytes participate in ischemic brain injury,
endothelin (ET) levels in plasma, supernatants of cultured monocytes in vitro and
those pretreated by dexamethason (DXM) were assayed by radioimmunoassay in 31
patients with acute cerebral infarction and 16 patients with hypertension (served
as control). Compared with the control group, the ET levels in supernatants of
cultured monocytes increased and positively related with those in plasma and
degree of neurological damage in the acute cerebral infarction group, while the
ET levels in supernatants of cultured monocytes pretreated by DXM decreased. This
suggests that intensifying the synthesis and release ET may be one of the
mechanisms for the involvement of monocytes in the pathologic process of ischemic
brain injury during acute cerebral infarction. DXM can improve this process by
inhibition of producing monocyte-derived ET.
PMID- 10681842
TI - [Clinical of 50 cases of aged patients with pneumonia caused by gram-negative
bacteria].
AB - The diagnosis and treatment of 50 cases of aged patients with pneumonia caused by
gram-negative G-bacteria (from Feb. 1993 to Aug. 1997) were analyzed. Before the
results of drug sensitive tests were reported, aminoglycosides plus broad
spectrum semisynthetic penicillin or first generation cephalosporin could improve
the curative effect in patients with good renal function. Bacterial culture and
drug sensitive tests were crucial for choosing the proper antibiotics.
PMID- 10681843
TI - [Surgical treatment of sacral tumor].
AB - From 1990 to 1996, 21 patients with sacral tumor were surgically, including 8
cases with giant tumor of bone, 7 cases of spinal cord tumor, each 2 cases of
neurofibroma and adenoma, 1 case of myeloma and 1 case of lipoma with low grade
of malignancy. A total of 22 operations involving one for recurrent tumors in 21
cases were performed. Sacral resection and curettage plus resection were the
surgical ways. 19 patients were followed up with an average period of 2.5 years.
15 patients showed good results, 3 patients occurred urinary incontinence and
constipation, one of 3 cases occurred weakness of ankles and feet. Authors
conclude that surgery should be advised and actively adopted for sacral tumors.
PMID- 10681844
TI - [Detection of interleukin-2 receptor in patients with idiopathic thrombocytopenic
purpura].
AB - Using ELISA and indirect fluorescent antibody techniques(IFAT), the serum soluble
inter-leukin-2 receptor(sIL-2R) and membrane IL-2R (mIL-2R) on lymphocyte cells
induced by phyto-hemagglutinin (PHA) were studied in patients with idiopathic
thrombocytopenic purpura (ITP). The results showed that the level of sIL-2R
increased significantly before treatment and decreased after treatment; the
percentages of mIL-2R induced by PHA decreased. There was no correlation between
the level of serum sIL-2R and that of mIL-2R. Our observations suggest that
increased level of serum sIL-2R in ITP patients may be one of causes evoking
cellular immunological abnormalities.
PMID- 10681845
TI - [MRI observation on Arnold-Chiari I malformation].
AB - Craniocerical junction of 42 patients with Arnold-Chiari I malformation (ACM-1)
and 41 normal controls were studied. In addition to the decendent tonsil, all the
components in the posterior cranial fossa including the 4th ventricle, oblongata
medulla and the sinus confluence of patients with ACM- 1 were decended. Although
the spinal foramen magnum anterior -posterior diameter was smaller but not
statistically different from the control. The results suggest that the main
pathology of ACM- 1 is the shallow and small posterior cranial fossa and the
resulted organ decendent as a whole.
PMID- 10681846
TI - [Antiviral and antibacterial actions of bingduqing granules in vitro].
AB - The antiviral and antibacterial actions in vitro of bingduqing granules which
consists of nine kinds of Chinese traditional medicinal herbs were observed. The
results showed that the inhibitive concentrations of bingduqing granules for Adv
7, RSV, HSV-1, and influenza virus A3, were >-6.9, 8.3, 13.8 and 83 mg x ml-1,
respectively; while the minimum inhibitive concentrations for Staphylococcus
aureus, Staphylococcus epidermidis, Type A and B Streptococci, and pseudomonas
aeruginosa were 0.03125, 0.03125, 0.125, 0.125, and 0.25 g x ml-1, respectively.
This study provide a pharmacodynamics basis for clinical application of
Bingduqing Granules in the treatment of respiratory tract infection.
PMID- 10681847
TI - [Culture of murine HPP-CFC in vitro using conditioned medium substitutefor
recombinant growth factors].
AB - OBJECTS: To study the clonal growth on single layer, agar of high proliferative
potential colony-forming cells (HPP-CFC) of bone marrow obtained from both normal
mice (NBM) and mice treated 2 days earlier with 5-fluorouracil (FU,BM) using
conditioned media. MATERIAL AND METHODS: Using liquid cell culture to harvert
WEHI2-CM and L929-CM as the substitutes for IL-3 and M-CSF respectively; using
semi-solid culture to assay HP-CFCin vitro. RESULTS: (1) the combination of WEHI3
CM and L929-CM produced HPP-CFC in vitro, and the addition of rhIL-1 alpha, rhIL
6 and rmGM-CSF further enhanced HPP-CFC was enriched in the FU2 BM. Morphological
investigation showed that the HPP-CFC colony was large and compact, great than
0.5mm in diameter and contained more than 50,000 cells, most of which were
macrophage like cells. The hydroxyurea suicide rate for HPP-CFC was less than
10%. CONCLUSION: The results suggested that (1) WEHI3-CM and L929-CM can be used
as the substitutes of IL-3 and M-CSF to stimulate the formation of HPP-CFC; (2)
FU can enrich HPP-CFC of the mice.
PMID- 10681848
TI - [Study on the clinical diagnostic values of MCV and RDW to homolytic anemia].
AB - In this study, the mean corpuscula volume (MCV) and the red blood cell
distribution width (RDW) were measured in 21 patients with hemolytic anemia, 35
patients with non-hemolytic anemia, and 100 healthy subjects were in the control
group. The result revealed that the changes of MCV and RDW in hemolytic anemia
and the other proliferative anemia were special. As diagnostic criterion of HA,
MCV and RDW showed high-sensitivity and specificity. It is useful for screening
HA patients.
PMID- 10681849
TI - [The factors affecting apoptosis by in situ terminal deoxynucleotide transferase
method].
AB - Apoptosis in biopsies of patients with hepatocirrhosis or hepatocellular
carcinoma and in small intestinal mucosa of mice were detected by the method of
in situ terminal deoxynucleotide transferase (ISTdT). It was found that the best
positive result might be obtained by digesting tissue sections with 25mg x L-1
proteinase K for 15 minutes, then treating sections with moderate degree of
microwave for 5 minutes after reaction with terminal deoxynucleotide transferase.
The best choice of above conditions were discussed.
PMID- 10681850
TI - [Boari flap ureteroplasty in the treatment of distal long-segment defect or
stricture of the ureter].
PMID- 10681851
TI - [Human sex identification in dried bloodstains by PCR using X-Y homologous
primers].
PMID- 10681852
TI - [Cerebrospinal fluid cytology in the diagnosis of cancerous meningitis].
PMID- 10681853
TI - [Clinical analysis of acute glomerulonephritis in 166 children].
PMID- 10681854
TI - [Effects of aprotinin on activated coagulation time in the patients during
cardiopulmonary bypass].
PMID- 10681855
TI - [Relation between fibromyalgia and bacterial urine].
PMID- 10681856
TI - [A case of multiple pathway associated with right bundle branch block].
PMID- 10681857
TI - [Magnesium sulfate in the treatment of point torsion of ventricular tachycardia
and fibrillation caused by haotenggen. A case report].
PMID- 10681858
TI - [Large calcified cerebral glioma. Report of 2 cases].
PMID- 10681859
TI - [Right ventricular myocardial infarction with cardiac aneurysm. A case report].
PMID- 10681860
TI - Literature research on screening of the nucleus acupoints for treatment of
intellectual disturbances.
PMID- 10681861
TI - Clinical analysis on the treatment of HIV/AIDS by traditional Chinese medicine.
PMID- 10681862
TI - Treatment of atrophic cholecystitis by regulating the spleen--a report of 50
cases.
AB - Fifty cases of atrophic cholecystitis were treated by regulating of the spleen.
Of them, 21 were cured, 18 remarkably effective, and 7 effective. The overall
effective rate was 92.0%. As compared with the results of ultrasonography B
performed before and after treatment, it was shown that both the longitudinal and
transverse inner diameters of the gallbladder increased evidently, and the
condition of atrophy improved remarkably after treatment.
PMID- 10681863
TI - An analysis for death causes in 45 cases of liver cancer treated with traditional
Chinese drugs.
AB - Among the 165 cases of late-stage liver cancer treated in our hospital, 65
(39.4%) died, with an average survival time of 8.1 months and a median survival
time of 7 months. Among the 65 dead patients, 45 were treated with traditional
Chinese drugs and 20 with western medicine. The average survival time was 8.4
months in the former and 7.3 months in the latter group. The direct causes of
death for the 65 patients were hepatic coma, severe hemorrhage of the upper
digestive tract, Heyd's syndrome, hepatorrhexis, respiratory failure, cardiac
failure, etc. The incidence rates of hemorrhage of the upper digestive tract and
hepatorrhexis in the 45 patients treated with traditional Chinese drugs were
obviously lower than those treated with western medicine.
PMID- 10681864
TI - 311 cases of chronic osteomyelitis treated by soaking with ganlingsan liquid.
AB - From 1992 to 1995, 311 cases of chronic osteomyelitis (including 145 cases of
hematogenic osteomyelitis, 147 cases of traumatic osteomyelitis, 8 cases of
secondary osteomyelitis after local infection, 4 cases due to other causes, and 7
cases with cause unknown) were treated by soaking with Ganlingsan liquid. The
average treatment course was 69.5 days. The results showed that 260 cases were
cured, 26 cases markedly effective, 20 cases improved, and 5 cases ineffective.
The evaluation of the function revealed that 150 cases were excellent, 129 cases
good, 10 cases improved, and 22 cases poor. 111 patients recovered from abnormal
erythrocyte sedimentation rate. External fixation was applied at the same time
for the patients accompanied by nonunion of fracture, and the therapeutic effect
was also satisfactory.
PMID- 10681865
TI - 380 cases of bronchiectasis with hemoptysis treated by point-injection.
PMID- 10681866
TI - Treatment of epiphora due to insufficiency of lacrimal passage by acupuncture at
Jingming.
AB - Since 1995, the authors have employed acupuncture at Jingming (UB 1) with the
warming needles to treat epiphora due to insufficiency of lacrimal passages. Of
the 68 treated eyes in 42 patients, 28 eyes were cured, 35 improved, and 5
ineffective with a total effective rate of 92.65%; and 12 eyes were cured and 34
improved by only one course of treatment.
PMID- 10681867
TI - Observation of the efficacy of acupuncture and moxibustion in 62 cases of chronic
colitis.
AB - 62 patients with chronic colitis were randomly divided into two groups.
Acupuncture and moxibustion at acupoints such as Tianshu (St 25), Guanyuan (Ren
4) were applied in the treatment group, and western drugs were applied in the
control group. The results showed that acupuncture and moxibustion had a marked
curative effective with few side effects, and therefore was readily acceptable to
the patients.
PMID- 10681868
TI - Twenty-three cases of atrophic rhinitis treated by deep puncture at three points
in the nasal region.
AB - Atrophic rhinitis is a disease which manifests itself mainly by anosmia due to
dryness and atrophy of the nasal mucosa. There is no specific therapy for the
disease at present. In the past few years, 23 cases of atrophic rhinitis were
treated mainly by deep puncture at three points in the nasal region with
satisfactory results. In order to find out the functional changes of the nasal
mucosa, the mucociliary transport rate (MTR), surface temperature of the conchal
mucosa, acid-base scale of nasal secretion, and volume of nasal secretion were
determined before and after the treatment.
PMID- 10681869
TI - Dr. Du Xiaoshan's personal experience in acupuncture treatment.
PMID- 10681870
TI - A parallel study on the effects in treatment of impotence by tonifying the kidney
with and that without improving blood circulation.
AB - 141 cases of functional impotence of the kidney-deficiency type were treated by
tonifying the kidney. On them, 103 cases at the same time were treated by
improving blood circulation and the other 38 cases by the former only. As a
result the total effective rate and the markedly effective rate in the former
were 84.46% and 46.60% respectively; but in the latter, 60.55% and 13.15%. A
significant difference was found in Ridit analysis (P < 0.05), indicating that
method of tonifying the kidney with improving blood circulation is much better
than by simply tonifying the kidney alone.
PMID- 10681871
TI - Clinical application of ciliao in acupuncture treatment.
PMID- 10681872
TI - A clinical observation on therapeutic effects of acupuncture for allergic
rhinitis.
PMID- 10681873
TI - Study on pathogenic mechanism of emotions in traditional Chinese medicine--an
observation of hydrogen peroxide releasing function of celiac macrophages in rats
under stress state.
AB - The hydrogen peroxide releasing function of macrophages in rats under the stress
state was observed with the animal model of "excessive anger impairing the
liver". The results showed that the volume of hydrogen peroxide released from the
macrophages in rats was decreased, while the corticosterone level in plasma
increased after stress. It indicates that stimulation of harmful emotions could
cause inhibition of immunoreaction of the organism, which might be related to the
enhancement in excitability of the hypothalamus-pituitary-adrenal axis and
hypersecretion of glucocorticoid hormone.
PMID- 10681874
TI - Effects of transient forebrain ischemia and radix Salviae miltiorrhizae (RSM) on
extracellular levels of monoamine neurotransmitters and metabolites in the gerbil
striatum--an in vivo microdialysis study.
AB - The aim of this study was to investigate the effect of 30 min forebrain ischemia,
followed by 120 min reperfusion on extracellular fluid (ECF) levels of dopamine
(DA), norepinephrine (NE), serotonin (5-HT) and their metabolites, homovanillic
acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the striatum of gerbils, so
as to obtain further information on the mechanism of Radix Salviae Miltiorrhizae
(RSM)-induced neuroprotection. Microdialysis was used to sample the extracellular
space. Dialysate was measured by high performance liquid chromatography with
electrochemical detector (HPLC-ED). ECF DA, NE levels increased from basal levels
by 282, 227 and 221 folds, by 9.14, 8.51 and 8.25 folds, respectively for the
three ischemic duration (0-10; 11-20; 21-30 min). ECF DA, NE, 5-HT levels in the
RSM-treated group were significantly decreased as compared with those in the
control group during ischemia (P < 0.01). The results suggested that monoamine
neurotransmitters were involved in ischemic neuron damage directly or indirectly;
and that RSM plays a protective role during cerebral ischemia by attenuating the
dysfunctions of monoamine neurotransmitters.
PMID- 10681875
TI - Reciprocal actions of acupoints on gastrointestinal peristalsis during
electroacupuncture in mice.
AB - Orthogonal design was used to observe the gastrointestinal peristalsis in normal
and atropine-treated mice after electroacupuncture was applied, singly or in
combination, at Neiguan (P 6), Pishu (UB 20) and Zusanli (St 36). The results
showed that: 1) electroacupuncture has no significant effect on the
gastrointestinal peristalsis in normal mice; 2) Pishu (UB 20) was significantly
antagonistic to Zusanli (St 36) in normal mice; 3) the decreased gastrointestinal
peristalsis in atropine-treated mice was markedly promoted by electroacupuncture
at Zusanli (St 36); and 4) Neiguan (P 6) was significantly antagonistic to Pishu
(UB 20) in atropine-treated mice. The results indicated that the reciprocal
actions among acupoints should be taken into consideration for point
prescription.
PMID- 10681876
TI - Considerations in making prescriptions for diabetes.
PMID- 10681877
TI - Clinical application of radix Aconiti lateralis preparata.
PMID- 10681878
TI - Rationale for the designing of a new model of compound electroacupuncture
moxibustion stimulator.
PMID- 10681879
TI - International Anesthesia Research Society 74th Clinical and Scientific Congress.
Honolulu, Hawaii, USA. March 10-14, 2000. Abstracts.
PMID- 10681880
TI - Abstracts of meetings of the International Federation of Clinical
Neurophysiology, 1998-1999.
PMID- 10681881
TI - Pathological Society of Great Britain and Ireland 178th meeting. 6-8 January
1999. Abstracts.
PMID- 10681882
TI - Pathological Society of Great Britain and Ireland 179th meeting. 7-9 July 1999.
Abstracts.
PMID- 10681883
TI - XXVII Symposium of the Italian Cancer Society. Milan, November 22-24, 1999.
Abstracts.
PMID- 10681884
TI - Socioeconomic status and health: what we know and what we don't.
AB - In the past 15 years, we have seen a marked increase in research on socioeconomic
status (SES) and health. Research in the first part of this era examined the
nature of the relationship of SES and health, revealing a graded association; SES
is important to health not only for those in poverty, but at all levels of SES.
On average, the more advantaged individuals are, the better their health. In this
paper we examine the data regarding the SES-health gradient, addressing causal
direction, generalizability across populations and diseases, and associations
with health for different indicators of SES. In the most recent era, researchers
are increasingly exploring the mechanisms by which SES exerts an influence on
health. There are multiple pathways by which SES determines health; a
comprehensive analysis must include macroeconomic contexts and social factors as
well as more immediate social environments, individual psychological and
behavioral factors, and biological predispositions and processes.
PMID- 10681885
TI - Epidemiology of socioeconomic status and health: are determinants within
countries the same as between countries?
AB - Within societies, health and ill-health follow a social gradient: lower
socioeconomic position, worse health. The slope of the gradient has varied over
time. It is likely that social and economic circumstances play a role in this
changing slope. Within Europe, differences in health between East and West have
also varied in magnitude. The advantage in the West increased through the 1970s
and 1980s. Although similar in their health trends up to 1989, the countries of
central and eastern Europe have diverged quite sharply subsequently. It is again
likely that changing social and economic fortunes account for these trends. There
is evidence to support the role of psychosocial factors in relating to
socioeconomic differences within and between countries.
PMID- 10681886
TI - Protective and damaging effects of mediators of stress. Elaborating and testing
the concepts of allostasis and allostatic load.
AB - Stress is a condition of human existence and a factor in the expression of
disease. A broader view of stress is that it is not just the dramatic stressful
events that exact their toll but rather the many events of daily life that
elevate activities of physiological systems to cause some measure of wear and
tear. We call this wear and tear "allostatic load," and it reflects not only the
impact of life experiences but also of genetic load; individual habits reflecting
items such as diet, exercise, and substance abuse; and developmental experiences
that set life-long patterns of behavior and physiological reactivity (see
McEwen). Hormones associated with stress and allostatic load protect the body in
the short run and promote adaptation, but in the long run allostatic load causes
changes in the body that lead to disease. This will be illustrated for the immune
system and brain. Among the most potent of stressors are those arising from
competitive interactions between animals of the same species, leading to the
formation of dominance hierarchies. Psychosocial stress of this type not only
impairs cognitive function of lower ranking animals, but it can also promote
disease (e.g. atherosclerosis) among those vying for the dominant position.
Social ordering in human society is also associated with gradients of disease,
with an increasing frequency of mortality and morbidity as one descends the scale
of socioeconomic status that reflects both income and education. Although the
causes of these gradients of health are very complex, they are likely to reflect,
with increasing frequency at the lower end of the scale, the cumulative burden of
coping with limited resources and negative life events and the allostatic load
that this burden places on the physiological systems involved in coping and
adaptation.
PMID- 10681887
TI - Health, hierarchy, and social anxiety.
AB - This paper suggests that the main reasons why populations with narrower income
differences tend to have lower mortality rates are to be found in the
psychosocial impact of low social status. There is now substantial evidence
showing that where income differences are greater, violence tends to be more
common, people are less likely to trust each other, and social relations are less
cohesive. The growing impression that social cohesion is beneficial to health may
be less a reflection of its direct effects than of its role as a marker for the
underlying psychological pain of low social status. Low social status affects
patterns of violence, disrespect, shame, poor social relations, and depression.
In its implications for feelings of inferiority and insecurity, it interacts with
other powerful health variables such as poor emotional attachment in early
childhood and patterns of friendship and social support. Causal pathways are
likely to center on the influence that the quality of social relations has on
neuroendocrine pathways.
PMID- 10681888
TI - Developmental influences across the life span.
PMID- 10681889
TI - Maternal care, gene expression, and the development of individual differences in
stress reactivity.
PMID- 10681890
TI - The biological embedding of early experience and its effects on health in
adulthood.
AB - Explanations of the socioeconomic gradient in health status must account for the
observations that the gradient cuts across a wide range of disease processes and
is capable of replicating itself on new disease processes as they emerge in
society. Understanding this pattern requires an understanding of how human
organisms can become generally vulnerable or resilient to disease over time: a
huge collation task across different disciplines. The hypothesis that best fits
current evidence is that the gradient is an "emergent property" of the
interaction between the developmental status of people and the material and
psychosocial conditions they encounter over their life course. Within this broad
formulation, special attention is given to child development, and the prospect
that socioeconomic differences in the quality of early life experiences
contribute to subsequent gradients in health status through socioeconomic
differences in brain sculpting and the conditioning of host defense systems that
depend on communication with the developing brain. The contribution to the
gradient in health is theorized to occur through a combination of latent effects,
pathway effects, and cumulative disadvantage.
PMID- 10681891
TI - Hierarchies of life histories and associated health risks.
AB - Widely documented inverse associations between socioeconomic standing and
incident chronic disease and mortality invite explanation in terms of pathways to
these outcomes. Empirical identification of pathways, or histories, requires
measures that assess cumulative wear and tear on physiological systems following
from psychosocial adversity and genetic predispositions. Such an assessment,
allostatic load, has been shown to predict later life mortality, incident
cardiovascular disease, and decline in physical and cognitive functioning. Using
data from the Wisconsin Longitudinal Study (WLS), we seek precursors to
allostatic load via ordered categories of cumulative adversity relative to
advantage over the life course. We operationalize these histories via unfolding
economic circumstances and social relationship experiences (e.g., parent-child
interactions, quality of spousal ties). Findings reveal a strong direct
association between the extent of adversity relative to advantage in an ordering
of these histories and likelihood of high allostatic load. Importantly, resilient
individuals with economic disadvantage, but compensating positive social
relationship histories also show low prevalence of high allostatic load.
PMID- 10681892
TI - What is the role of the social environment in understanding inequalities in
health?
PMID- 10681893
TI - Social capital and community effects on population and individual health.
AB - Social capital refers to those features of social relationships--such as levels
of interpersonal trust and norms of reciprocity and mutual aid--that facilitate
collective action for mutual benefit. Social capital is believed to play an
important role in the functioning of community life across a variety of domains,
ranging from the prevention of juvenile delinquency and crime, the promotion of
successful youth development, and the enhancement of schooling and education to
the encouragement of political participation. More recently, researchers have
begun to apply the concept to explain variations in health status across
geographic localities. In preliminary analyses, the higher the stocks of social
capital (as indicated by measures of trust and reciprocity in social surveys),
the higher appear to be the health achievement of a given area. Strengthening the
social capital within communities may provide an important avenue for reducing
socioeconomic disparities in health.
PMID- 10681894
TI - Socioeconomic status and chronic stress. Does stress account for SES effects on
health?
AB - Socioeconomic status (SES) is an important predictor of a range of health and
illness outcomes. Research seeking to identify the extent to which this often
reported effect is due to protective benefits of higher SES or to toxic elements
of lower social status has not yielded consistent or conclusive findings. A
relatively novel hypothesis is that these effects are due to chronic stress that
is associated with SES; lower SES is reliably associated with a number of
important social and environmental conditions that contribute to chronic stress
burden, including crowding, crime, noise pollution, discrimination, and other
hazards or stressors. In other words, chronic stress may capture much of the
variance in health and social outcomes associated with harmful aspects of lower
social status. Low SES is generally associated with distress, prevalence of
mental health problems, and with health-impairing behaviors that are also related
to stress. Research targeting this hypothesis is needed to determine the extent
to which stress is a pathway linking SES and health.
PMID- 10681895
TI - Status, stress, and atherosclerosis: the role of environment and individual
behavior.
AB - Atherosclerosis induced by moderate hyperlipoproteinemia in group-housed
cynomolgus monkeys differs significantly between animals of dominant and
subordinate social status. The nature of this association also varies by sex, and
in males, by stability of the social environment. Dominant males develop more
extensive atherosclerosis than subordinates when housed in unstable, but not
stable, social groups; in contrast, subordinate females develop greater
atherosclerosis than dominants, and do so irrespective of the conditions of
social housing. Experimental investigations reveal that the first of these
associations (males) is mediated by concomitant sympathoadrenal activation and
the second (females) by ovarian impairment associated with the stress of social
subordination. We believe our findings offer clues to the neuroendocrine
mediation of behavioral influences on coronary artery disease in humans. This is
particularly true where these influences reflect asymmetries in the power or
status relationships among individuals within similar social environments, or
when dimensions of temperament or disposition give rise to such relationships. We
propose that these data also may be informative regarding the pathophysiological
sequelae of social stratification (in which disease incidence varies by class
membership within populations), but only where social environments engendered by
class inequalities exacerbate status-dependent behavioral differences among
individuals within communities of associates.
PMID- 10681896
TI - Stress responses in low-status jobs and their relationship to health risks:
musculoskeletal disorders.
AB - Conditions typical of many low-status jobs are known to induce elevated stress.
In keeping with this, blue-collar workers show elevated psychophysiological
stress levels both during and after work compared with workers in more
stimulating and flexible jobs. Health-related behaviors, such as cigarette
smoking and drug abuse, that are known to contribute to the social gradient in
health, can be seen as ways of coping with a stressful work situation in order to
get short-term relief. Negative emotional states associated with low-status jobs,
combined with a lack of economic resources, are also likely to reduce the
individual's motivation to seek proper medical treatment and, thus, increase the
risk that transient symptoms develop into chronic illness. With regard to
musculoskeletal disorders, it is well documented that physically monotonous or
repetitive work is associated with an increase in neck, shoulder, and low back
pain problems. However, recent studies also report an association between
psychosocial factors and muscle pain syndromes. Possible mechanisms explaining
these findings involve the assumption that psychological stress may induce
sustained activation of small, low-threshold motor units that may lead to
degenerative processes, damage, and pain. Analysis of short periods of very low
muscular electrical activity (EMG gaps) shows that female workers with a high
frequency of EMG gaps seem to have less risk of developing myalgia problems than
do workers with fewer gaps. Stress induced by psychosocial conditions at work,
which is usually more lasting than that resulting from physical demands, may
prevent the individual from shutting off their physiological activation and
reduces the time for rest and recovery. In the modern work environment, with
strong emphasis on a high work pace, competitiveness, and efficiency, it is
possible that lack of relaxation is an even more important health problem than is
the absolute level of contraction or the frequency of muscular activation.
PMID- 10681897
TI - Race, socioeconomic status, and health. The added effects of racism and
discrimination.
AB - Higher disease rates for blacks (or African Americans) compared to whites are
pervasive and persistent over time, with the racial gap in mortality widening in
recent years for multiple causes of death. Other racial/ethnic minority
populations also have elevated disease risk for some health conditions. This
paper considers the complex ways in which race and socioeconomic status (SES)
combine to affect health. SES accounts for much of the observed racial
disparities in health. Nonetheless, racial differences often persist even at
"equivalent" levels of SES. Racism is an added burden for nondominant
populations. Individual and institutional discrimination, along with the stigma
of inferiority, can adversely affect health by restricting socioeconomic
opportunities and mobility. Racism can also directly affect health in multiple
ways. Residence in poor neighborhoods, racial bias in medical care, the stress of
experiences of discrimination and the acceptance of the societal stigma of
inferiority can have deleterious consequences for health.
PMID- 10681898
TI - Pathways by which SES and ethnicity influence cardiovascular disease risk
factors.
AB - Little is known about pathways by which socioeconomic status (SES) translates
into individual differences in cardiovascular disease (CVD) risk factors. Because
the socioeconomic structure is not the same for all ethnic subgroups, the
pathways that lead to the development of CVD risk factors may vary by both SES
and ethnicity. We used data from a large national survey to examine the
independent associations of two indicators of SES (education and income) and
ethnicity with six primary CVD risk factors. We then used data on smoking that
reflected a temporal sequence to examine the extent to which SES and ethnicity
influenced smoking at three different time points, from smoking onset, to a
serious quit attempt, to successful quitting. These analyses provide an
understanding of the relationships between SES, ethnicity, and CVD risk factors
and suggest that if the timing, focus, and content of intervention programs take
pathways into account they will result in more successful outcomes.
PMID- 10681899
TI - Psychosocial resources and the SES-health relationship.
AB - Psychosocial resources, which include optimism, coping style, a sense of mastery
or personal control, and social support, influence the relationship between SES
and health. To varying degrees, these resources appear to be differentially
distributed by social class and related to health outcomes. Such resources may
partially mediate the impact of SES on health. For example, environments that
undermine personal control may have an impact on chronic arousal and the
corresponding development of disease, such as CHD. Psychosocial resources may
also moderate the impact of SES on health. For example, a large number of
positive social relationships and a few conflictual ones may buffer individuals
against the adverse effects of SES-related stress. These psychosocial resources
are moderately intercorrelated, and so a research strategy that explores their
coherence as a psychosocial profile that promotes resilience to stress is tenable
and merits empirical examination. The erosion of these resources as one moves
lower on the SES scale and specific factors that contribute to such erosion are
discussed.
PMID- 10681900
TI - Do negative emotions mediate the association between socioeconomic status and
health?
AB - In this chapter, we examine the possibility that negative emotions contribute to
the relationship between socioeconomic status (SES) and health. A model of the
associations among SES, emotion, and health is presented first. We then review
the evidence for this model, showing associations of SES with depression,
hopelessness, anxiety, and hostile affect and cognition, and of these negative
emotions with disease. Notably, most of the data supporting the model provide
only indirect evidence that negative emotions serve as a key contributor to the
proposed associations. We, therefore, conclude with recommendations for
longitudinal research, especially in children, that will more directly and
comprehensively examine negative emotions as possible mediators of the SES and
health relationship.
PMID- 10681901
TI - Social status and susceptibility to respiratory infections.
AB - Adults and children of lower socioeconomic status (SES) are at higher risk for a
wide range of communicable infectious diseases, especially respiratory
infections. Greater risk for infectious illness among people with lower SES is
thought to be attributable to increased exposure to infectious agents and
decreased host resistance to infection. We summarize three studies that examine
the prospective association of several markers of social status (unemployment,
perceived and observed social status) with host resistance to upper respiratory
infections. Unemployment was associated with increased susceptibility to
infection in adult humans. Lower social status in male monkeys was also
associated with increased susceptibility, as was lower perceived social status in
humans. The association of social status and susceptibility was accounted for
primarily by increased risk in the lowest social status groups. However, further
increases in social status were associated with further decreases in
susceptibility in both monkeys and humans.
PMID- 10681902
TI - Sleep as a mediator of the relationship between socioeconomic status and health:
a hypothesis.
AB - This article discusses the hypothesis that the adverse impact of low
socioeconomic status (SES) on health may be partly mediated by decrements in
sleep duration and quality. Low SES is frequently associated with a diminished
opportunity to obtain sufficient sleep or with environmental conditions that
compromise sleep quality. In a recent study, we examined carbohydrate metabolism,
endocrine function, and sympatho-vagal balance in young, healthy adults studied
after restricting sleep to four hours per night for six nights as compared to a
fully rested condition obtained by extending the bed-time period to 12 hours per
night for six nights. The state of sleep debt was associated with decreased
glucose tolerance, elevated evening cortisol levels, and increased sympathetic
activity. The alterations in glucose tolerance and hypothalamo-pituitary-adrenal
function were qualitatively and quantitatively similar to those observed in
normal aging. These results indicate that sleep loss can increase the "allostatic
load" and facilitate the development of chronic conditions, such as obesity,
diabetes, and hypertension, which have an increased prevalence in low SES groups.
PMID- 10681903
TI - Cardiovascular pathways: socioeconomic status and stress effects on hypertension
and cardiovascular function.
AB - In westernized societies there is a consistent and continuous gradient between
the prevalence of cardiovascular disease (including both coronary heart disease
and stroke) with SES, such that people from lower SES have more disease. Several
studies have examined the roles of the major cardiovascular risk factors for
explaining this gradient. There is a strong SES gradient for smoking, which
parallels the gradient in disease, but the gradients for hypertension and
cholesterol are weak or absent. Central obesity and physical inactivity may also
be contributory factors. In the United States there is a strong association
between SES and race, and it is suggested that the higher prevalence of
hypertension and cardiovascular disease in blacks may be attributed to
psychosocial factors, including those related to SES. The possible pathways by
which SES affects cardiovascular disease include effects of chronic stress
mediated by the brain, differences in lifestyles and behavior patterns, and
access to health care. At the present time, the second of these is the strongest
candidate; the effects of stress have been little studied.
PMID- 10681904
TI - Public policy frameworks for improving population health.
AB - Four conceptual frameworks provide bases for constructing comprehensive public
policy strategies for improving population health within wealthy (OECD) nations.
(1) Determinants of population health. There are five broad categories: genes and
biology, medical care, health behaviors, the ecology of all living things, and
social/societal characteristics. (2) Complex systems: Linear effects models and
multiple independent effects models fail to yield results that explain
satisfactorily the dynamics of population health production. A different method
(complex systems modeling) is needed to select the most effective interventions
to improve population health. (3) An intervention framework for population health
improvement. A two-by-five grid seems useful. Most intervention strategies are
either ameliorative or fundamentally corrective. The other dimension of the grid
captures five general categories of interventions: child development, community
development, adult self-actualization, socioeconomic well-being, and modulated
hierarchical structuring. (4) Public policy development process: the process has
two phases. The initial phase, in which public consensus builds and an
authorizing environment evolves, progresses from values and culture to
identification of the problem, knowledge development from research and
experience, the unfolding of public awareness, and the setting of a national
agenda. The later phase, taking policy action, begins with political engagement
and progresses to interest group activation, public policy deliberation and
adoption, and ultimately regulation and revision. These frameworks will be
applied to help understand the 39 recommendations of the Independent Inquiry into
Inequalities in Health, the Sir Donald Acheson Report from the United Kingdom,
which is the most ambitious attempt to date to develop a comprehensive plan to
improve population health.
PMID- 10681905
TI - Socioeconomic status and health. Policy implications in research, public health,
and medical care.
AB - The role of public policy in research, public health, and medical care is
discussed as well as the extent to which public policy has been informed by
increased knowledge about the relationship between SES and health and to what
extent policy has affected SES-related health disparities. Observations on
current healthcare policy and recommendations for the future are offered.
PMID- 10681906
TI - Solving the puzzle of socioeconomic status and health: the need for integrated,
multilevel, interdisciplinary research.
PMID- 10681907
TI - Social class differences in morbidity using the new U.K. National Statistics
Socio-Economic Classification. Do class differences in employment relations
explain class differences in health?
PMID- 10681908
TI - Orthostatic blood pressure responses as a function of ethnicity and socioeconomic
status: the ARIC study.
PMID- 10681909
TI - Social class as a moderator of income effects on stress and health outcomes
across nine years.
PMID- 10681910
TI - Socioeconomic disparities in adult oral health in the United States.
PMID- 10681911
TI - Income inequality, social trust, and self-reported health status in high-income
countries.
PMID- 10681912
TI - The Human Development Index and Per Capita Gross National Product as predictors
of dental caries prevalence in industrialized and industrializing countries.
PMID- 10681913
TI - Pathways between area-level income inequality and increased mortality in U.S.
men.
PMID- 10681914
TI - Education, income, wealth, and health among whites and African Americans.
PMID- 10681915
TI - Income inequality and mortality in Canada and the United States. An analysis of
provinces/states.
PMID- 10681916
TI - For richer, for poorer, in sickness and in health: socioeconomic status and
health among married couples.
PMID- 10681917
TI - Determinants of health: testing of a conceptual model.
PMID- 10681918
TI - The direct and indirect effects of metropolitan area inequality on mortality. A
hierarchical analysis.
PMID- 10681919
TI - Unbundling education: a critical discussion of what education confers and how it
lowers risk for disease and death.
PMID- 10681920
TI - Socioeconomic disparities in adolescent health: contributing factors.
PMID- 10681921
TI - Effects of socioeconomic status and psychosocial stress on the development of the
fetus.
PMID- 10681922
TI - Social position, age, and memory performance in the Whitehall II Study.
PMID- 10681923
TI - Social dominance and cardiovascular reactivity in preschoolers. Associations with
SES and health.
PMID- 10681925
TI - Racial differences in education, obesity, and health in later life.
PMID- 10681924
TI - Markers of transition to adulthood, socioeconomic status of origin, and
trajectories of health.
PMID- 10681926
TI - Limitations to the use of education as an SES indicator in studies of the
elderly. Confounding by cognition.
PMID- 10681927
TI - Parenting behavior and emotional health as mediators of family poverty effects
upon young low-birthweight children's cognitive ability.
PMID- 10681928
TI - Socioeconomic factors and emergency pediatric ICU admissions.
PMID- 10681929
TI - Socioeconomic status and health among elderly people in Sweden.
PMID- 10681930
TI - A multivariate model of functional decline in the elderly: the differential
influence of income versus education.
PMID- 10681931
TI - Socioeconomic status, social support, age, and health.
PMID- 10681932
TI - Measurement of social capital.
PMID- 10681933
TI - Racism and health: segregation and causes of death amenable to medical
intervention in major U.S. cities.
PMID- 10681934
TI - Identifying social pathways for health inequalities. The role of housing.
PMID- 10681935
TI - Transitions into poverty following job loss and the depression-reemployment
relationship.
PMID- 10681936
TI - Longitudinal effects of occupational, psychological, and social background
characteristics on health of older workers.
PMID- 10681937
TI - Social class and social cohesion: a content validity analysis using a
nonrecursive structural equation model.
PMID- 10681938
TI - The effect of job strain on ambulatory blood pressure in men: does it vary by
socioeconomic status?
PMID- 10681939
TI - Socioeconomic differences in social information processing and cardiovascular
reactivity.
PMID- 10681940
TI - Social environmental stress in indigenous populations: potential biopsychosocial
mechanisms.
PMID- 10681941
TI - Social status, anabolic activity, and fat distribution.
PMID- 10681942
TI - Socioeconomic status as a correlate of sleep in African-American and Caucasian
women.
PMID- 10681943
TI - The differential effects of sleep quality and quantity on the relationship
between SES and health.
PMID- 10681944
TI - Stress responsivity and body fatness: links between socioeconomic status and
cardiovascular risk factors in youth.
PMID- 10681945
TI - Social class differences in maternal stress appraisal during pregnancy.
PMID- 10681946
TI - The effects of race, gender, and education on the structure of self-rated health
among community-dwelling older adults.
PMID- 10681947
TI - Socioeconomic differences in measures of hostility.
PMID- 10681948
TI - SES and oral health status in an elderly population.
PMID- 10681949
TI - Hostility, coronary heart disease, and ischemia. The role of socioeconomic
status.
PMID- 10681950
TI - Education, infant health, and cigarette smoking.
PMID- 10681951
TI - Morbidity and health--National Health Interview Survey, 1987. In generalized
additive models.
PMID- 10681952
TI - Neighborhood socioeconomic context and adult health. The mediating role of
individual health behaviors and psychosocial factors.
PMID- 10681953
TI - Goal-striving stress, social economic status, and the mental health of black
Americans.
PMID- 10681954
TI - Moderating and mediating effects of socioeconomic status, perceived peer condom
use, and condom negotiation on sexual risk behavior among African-American and
white adolescent females.
PMID- 10681955
TI - Dissociative disruptions--psychological (psychosocial) pathways uncovered in the
healing process.
PMID- 10681956
TI - Does cognitive functioning mediate the well-documented link between education and
functional disability in middle-aged adults?
PMID- 10681957
TI - Socioeconomic status and health: a new explanation.
PMID- 10681958
TI - A framework for evidenced-based reviews of interventions for supportive social
environments.
PMID- 10681959
TI - Social ordering in developing countries: does hierarchy have the same effect as
in post-industrial nations? A look at Nepal.
PMID- 10681960
TI - SES, Medicare coverage, and flu shot utilization among vulnerable women in the
women's health and aging study.
PMID- 10681961
TI - The association of race/socioeconomic status and use of Medicare services. A
little-known failure in access to care.
PMID- 10681962
TI - Natural and bioterrorist/biocriminal threats to food and agriculture.
PMID- 10681963
TI - Agriculture and food security.
PMID- 10681964
TI - The Soviet Union's anti-agricultural biological weapons.
PMID- 10681965
TI - The threat posed by the global emergence of livestock, food-borne, and zoonotic
pathogens.
PMID- 10681966
TI - Contemporary global movement of emerging plant diseases.
AB - Plant diseases are a significant constraint to agricultural productivity. Exotic
plant diseases pose a continued threat to profitable agriculture in the United
States. The extent of this threat has increased dramatically in the 1980s and
1990s due to the expansion of international trade in agricultural products and
frequent movement of massive volume of people and goods across national
boundaries. Introduction of new diseases has not only caused farm losses, but has
also diminished export revenue since phytosanitary issues are linked to
international commerce. Plant pathogens and their vectors have also moved across
national boundaries, sometimes naturally and at other times influenced by the
recent changes in trade practices. Sorghum ergot, Karnal bunt of wheat, potato
late blight, and citrus tristeza are some of the most recent examples of enhanced
importance of diseases due to the introduction of plant pathogens or vectors.
PMID- 10681967
TI - Biological warfare training. Infectious disease outbreak differentiation
criteria.
AB - The threat of biological terrorism and warfare may increase as the availability
of weaponizable agents increase, the relative production costs of these agents
decrease, and, most importantly, there exist terrorist groups willing to use
them. Therefore, an important consideration during the current emphasis of
heightened surveillance for emerging infectious diseases is the capability to
differentiate between natural and intentional outbreaks. Certain attributes of a
disease outbreak, while perhaps not pathognomic for a biological attack when
considered singly, may in combination with other attributes provide convincing
evidence for intentional causation. These potentially differentiating criteria
include proportion of combatants at risk, temporal patterns of illness onset,
number of cases, clinical presentation, strain/variant, economic impact,
geographic location, morbidity/mortality, antimicrobial resistance patterns,
seasonal distribution, zoonotic potential, residual infectivity/toxicity,
prevention/therapeutic potential, route of exposure, weather/climate conditions,
incubation period, and concurrence with belligerent activities of potential
adversaries.
PMID- 10681968
TI - The U.S. Department of Agriculture Food Safety and Inspection Service's
activities in assuring biosecurity and public health protection.
PMID- 10681969
TI - Safeguarding production agriculture and natural ecosystems against biological
terrorism. A U.S. Department of Agriculture emergency response framework.
AB - Foreign pest introductions and outbreaks represent threats to agricultural
productivity and ecosystems, and, thus, to the health and national security of
the United States. It is advisable to identify relevant techniques and bring all
appropriate strategies to bear on the problem of controlling accidentally and
intentionally introduced pest outbreaks. Recent political shifts indicate that
the U.S. may be at increased risk for biological terrorism. The existing
emergency-response strategies of the Animal and Plant Health Inspection Services
(APHIS) will evolve to expand activities in coordination with other emergency
management agencies. APHIS will evolve its information superstructure to include
extensive application of simulation models for forecasting, meteorological
databases and analysis, systems analysis, geographic information systems,
satellite image analysis, remote sensing, and the training of specialized cadres
within the emergency-response framework capable of managing the necessary
information processing and analysis. Finally, the threat of key pests ranked
according to perceived risk will be assessed with mathematical models and "what
if" scenarios analyzed to determine impact and mitigation practices. An
infrastructure will be maintained that periodically surveys ports and inland
regions for the presence of exotic pest threats and will identify trend
abnormalities. This survey and monitoring effort will include cooperation from
industry groups, federal and state organizations, and academic institutions.
PMID- 10681970
TI - Guarding against natural threats and terrorist attacks. An industry perspective.
PMID- 10681971
TI - The role of national animal health emergency planning.
AB - Bioterrorism is one of many contingencies that we must be better prepared to
prevent from adversely impacting our food security system. Education and
awareness, prevention-based training, increased monitoring and surveillance, and
greater focus on coordination between government agencies at both the federal and
state levels will be necessary to develop a more prevention-based national food
security system. The formation of the Steering Committee on National Animal
Health Emergency Management is the beginning of a profound new process. The
animal industry is driving the formation of a new national animal health
emergency management system. It is designed to coordinate the emergency
prevention and response activities of all partners, including government (state
and federal), livestock producers, and veterinary practitioners. The goal is to
develop a national coordinated strategy that places primary emphasis on
preventing a broader spectrum of hazards from occurring throughout the food
production chain. Coordination and integration of efforts are necessary with many
different stakeholders, including government agencies other than U.S. Department
of Agriculture. Through a proposed National Animal Health Emergency Management
Council, all stakeholders can assist in the development of a national strategic
plan that can better protect our food security system.
PMID- 10681972
TI - Industry concerns and partnerships to address emerging issues.
PMID- 10681973
TI - International economic considerations concerning agricultural diseases and human
health costs of zoonotic diseases.
PMID- 10681974
TI - The cost of disease eradication. Smallpox and bovine tuberculosis.
AB - Although eradication is the ideal approach to reduce the economic and human
health costs of disease, there may be both short- and long-term consequences. A
$300 million effort succeeded in completely eradicating smallpox in less than ten
years. The campaign was effective because variola virus produced acute illness,
had no carrier stage or non-human reservoirs, and had an effective vaccine that
was used in combination with international surveillance and public education.
Bovine tuberculosis was completely eradicated in many U.S. herds at a cost of
$450 million over 50 years using a "test and slaughter" program combined with
meat inspection. Mycobacterium bovis often does not produce acute disease,
persists in the carrier stage, has multiple non-human reservoirs, and easily
crosses species. No effective vaccine or centralized global surveillance or
eradication programs currently exist. Control measures result in significant
economic losses. Smallpox eradication had limited economic consequences but has
left much of world's population highly susceptible to zoonotic orthopoxviruses
and to the use of smallpox as a biologic weapon. The primary threat of M. bovis
exists in wildlife that share watering holes or pasture land with domestic stock.
In the developed world, surveillance can minimize risks, but one-third of the
world's population lacks effective agricultural and food safety programs, leaving
them at substantial risk for zoonotic infection by M. bovis.
PMID- 10681975
TI - Economic considerations of agricultural diseases.
PMID- 10681976
TI - Regionalization's potential in mitigating trade losses related to livestock
disease entry.
PMID- 10681977
TI - Foreign animal disease agents as weapons in biological warfare.
PMID- 10681978
TI - Tools and methods for protection of targets and infrastructures associated with
food and agriculture industries.
PMID- 10681979
TI - Infecting soft targets. Biological weapons and Fabian forms of indirect grand
strategy.
PMID- 10681980
TI - The first step toward building tools and methods for protection.
PMID- 10681981
TI - Targeted immune design using RNA immunization.
PMID- 10681982
TI - Sensitive and rapid identification of biological threat agents.
PMID- 10681983
TI - United States of America v. Ray Wallace Mettetal, Jr. Preliminary observations.
PMID- 10681984
TI - Terrorism overview.
PMID- 10681985
TI - The changing biological warfare threat. Anti-crop and anti-animal agents.
PMID- 10681986
TI - Trends in American agriculture. Their implications for biological warfare against
crop and animal resources.
AB - Current trends in American agriculture have changed the vulnerability to use of
biological weapons against plant and animal resources. The major effect has been
a requirement to look again at the model of the U.S. BW program of widespread
dissemination of agent and look to attack models requiring much lower levels of
resources. The U.S. biological warfare program models must take the effects of
these major trends into account when considering the possible widespread
dissemination of a biological agent. The models must also acknowledge the lowered
levels or resources required to make such attacks given the modern trends in
American agriculture.
PMID- 10681987
TI - Agroterrorism. Agricultural infrastructure vulnerability.
AB - The intentional contamination of animal feed to reduce the availability of animal
derived human food or to infect human populations is seldom mentioned, but animal
feed could be an easy target for bioterrorists. The period of delay between the
contamination of the animal feed and adulteration of the human food product
provides an additional degree of uncertainty about the source of the
contamination and minimizes the possibility of apprehending the terrorist. The
less obvious and more natural the source of biological contamination, the greater
the likelihood that the animal feed contamination will be mistaken as a natural
phenomenon. However, the problems related to managing natural food contamination
and intentional food contamination remain the same. Rapid testing and separation
of contaminated feed are important steps, followed by the more specific
identification of the contaminant to determine the source of adulteration and/or
the possibility of decontamination. At this time identification of the bioagents
is dependent on the availability of antibody-specific test systems. The rapid
development of specific antibodies for the development of sensitive and specific
test kits is the key to identifying contamination and dealing effectively with
the disposal or decontamination of the animal feed and, ultimately, preventing
the contamination of animal-derived human food products.
PMID- 10681988
TI - The need for a coordinated response to food terrorism. The Wisconsin experience.
PMID- 10681989
TI - The threat of bioterrorism to U.S. Agriculture.
PMID- 10681990
TI - Where have all my pumpkins gone? The vulnerability of insect pollinators.
PMID- 10681991
TI - The role of pesticides in agricultural crop protection.
PMID- 10681992
TI - The status and role of vaccines in the U.S. food animal industry. Implications
for biological terrorism.
AB - This paper was intended to highlight some of the disease agents that could be
used effectively in acts of terrorism. In terms of vaccine countermeasures, we
face situations on both ends of the spectrum--(1) we and other nations have not
invested enough and have not been successful in developing or licensing any
protective vaccines and (2) where vaccines are available but not commercially
used due to current FAD policies we have not stockpiled them in sufficient doses
should regular practices fail to contain an outbreak. It is hoped that this paper
provokes additional thought and planning for those government agencies involved
in the business of national food animal agricultural welfare. Vaccine
technologies are available or are being developed to provide new and improved
vaccines against these highly contagious agents.
PMID- 10681993
TI - Exotic diseases of citrus. Threats for introduction?
PMID- 10681994
TI - What should the G8 do about the biological warfare threat to international food
safety?
PMID- 10681995
TI - A domestic legislative agenda for improving food safety and safeguards from
terrorist attacks on the U.S. food supplies and U.S. Agricultural interests.
PMID- 10681996
TI - [From genetic screening to surgical cancer prophylaxis].
PMID- 10681997
TI - [Predictive genetic investigations. Individualization of diagnosis and treatment
in families with multiple endocrine neoplasia type II].
AB - BACKGROUND AND OBJECTIVE: When multiple endocrine neoplasia type 2 (MEN2) is
suspected, genetic tests are at the centre of screening procedures. It was the
aim of this study to compare the diagnostic value of molecular biological
investigations with that of conventional biochemical tests. PATIENTS AND METHODS:
The study cohort consisted of all 144 patients cared for in our department since
1990 with the suspected diagnosis of MEN2 (evidence of a medullary thyroid
carcinoma [MTC]), coexistence of two MEN2 tumours or a family history of MEN2. 14
of the 144 patients (from 12 families) were already known to have an hereditary
MTC, while the remaining 130 had been referred for further diagnostic
investigations. RESULTS: An hereditary MTC was diagnosed in 22 of the 130
patients, a sporadic MTC in 32, while no definitive classification was possible
in 20 MTC patients without a positive family history and on whom no mutation
analysis had been performed. MEN2 was excluded in 56 family members. All 22
patients with newly diagnosed MTC had abnormally high calcitonin levels. A germ
line mutation in the RET proto-oncogene was found in 8 of the 9 families who had
undergone molecular biological tests. The investigate results led to a
thyroidectomy in 19 of the 22 patients with hereditary MTC; in all of them the
surgical specimen showed C-cell hyperplasia and/o MTC. CONCLUSION: These results
emphasize the importance of genetic tests in family screening. Preoperative
measurement of calcitonin remains essential in MEN2 families in whom a germ-line
mutation is not known. The choice of the appropriate diagnostic test must be
individualized to the particular patients so that optimal results are obtained.
PMID- 10681998
TI - [Decubitus ulcer in the terminal phase: epidemiologic, medicolegal and ethical
aspects].
AB - BACKGROUND AND OBJECTIVES: Pressure sores usually result from insufficient
preventive measures. They are particularly omnipresent among dying persons in
geriatric care. This study deals with prevalence, risk factors and the
significance of the nursing environment. PATIENTS AND METHODS: The prevalence of
pressure sores among the dead was analysed in a prospective cross-sectional study
based on 10,222 postmortem examinations in a crematorium in Hamburg. RESULTS: The
overall prevalence of pressure sores from grades I to IV was 11.2% (grade I:
6.1%, grade II: 3%, grade III: 1.1%, grade IV: 0.9%). A final logistic regression
model showed that pressure sores of Grade III or IV were associated with female
gender, date of death in the summer, marasmus, stroke history, neurological
disease in general, kidney disease, preceding traumatic events and nursery home
residence at the time of death. More than half of all the grade IV cases were
diagnosed among nursing home residents whereas those who had died in hospitals
contributed to only 11.5% of all the grade IV cases (dead from private homes
34.4%). Nursing home residence was associated with female gender, marasmus and
stroke history which predisposed to a higher rate of pressure sores. CONCLUSIONS:
Nursing homes are confronted with the highest proportion of pressure sores among
dying people when compared to hospitals or private home care. Failure to meet the
standards of preventive action against pressure sores point to the shortfalls in
the present public health sector and nursing home regulations as well as the
medical responsibility for supervision of nursing care. Apart from established
standards of care, medicolegal assessment of high-grade pressure sores should
also take ethical considerations into account when considering maximum therapy
goals among dying persons.
PMID- 10682000
TI - [Alveolar echinococcosis: diagnosis].
PMID- 10681999
TI - [A patient with an ACTH-producing pituitary tumor with liver metastasis].
AB - HISTORY AND FINDINGS: A 57-year-old woman had an ACTH-producing pituitary adenoma
twice resected, followed by bilateral adrenalectomy for recurrent
hypercortisolism. She subsequently developed a secondary postadrenalectomy
syndrome (Nelson's tumour) which required further surgery and radiotherapy. The
patient now presented for elucidation of a space-occupying lesion in the liver,
found incidentally on abdominal ultrasonography. INVESTIGATIONS:
Immunocytochemistry of the liver biopsy revealed ACTH-producing cells that were
structurally identical to the cells found in the specimen resected at the
previous operation. Changes were also found in the lower thoracic vertebrae,
suspicious of metastases, thus suggesting a metastasizing hypophyseal carcinoma.
RESULTS AND COURSE: Resection of the primary tumour and subsequent radiotherapy
had arrested the corticotropic, thyrotropic, and gonadotropic functions of the
pituitary, which had been adequately treated by administration of the
corresponding hormones. Ocreotide, bromocriptin or cytostatics were not given
because of their reported doubtful efficacy. At the time of diagnosis of the
malignancy a curative operation on the liver or palliative embolization of the
liver metastases were not possible because of their number and size. The bone
metastases were managed palliatively by radiotherapy. CONCLUSION: No curative
treatment has been found for the 66 cases of hypophyseal carcinoma reported so
far. Screening investigations in patients with operated pituitary adenoma with
the aim of eliciting an early diagnosis of possible malignancy cannot, therefore,
be recommended, particularly since renewed tumour growth and local invasiveness
do not constitute criteria for the diagnosis of pituitary carcinoma.
PMID- 10682001
TI - [Drug interactions with the cytochrome P-450 system].
PMID- 10682002
TI - [Medication prescriptions and costs in diabetic polyneuropathy].
PMID- 10682003
TI - [Lack of joy of publication in German biomedical research-- habilitation as a
brake?].
PMID- 10682004
TI - Relief of acute pain: a basic human right?
PMID- 10682005
TI - Allies or enemies? Evidence-based medicine and consumer choice.
PMID- 10682006
TI - Hepatitis A, liver transplants and indigenous communities.
PMID- 10682007
TI - Towards unity for health.
PMID- 10682008
TI - Patient attitudes to commonly promoted medical interventions.
AB - OBJECTIVE: To survey attitudes about three "best practice" medical interventions
(hormone replacement therapy [HRT], thrombolysis for acute myocardial infarction
[THROM] and coronary artery by-pass surgery [CABS]) in a sample of patients, and
identify factors associated with those attitudes. SETTINGS: Metropolitan tertiary
care hospital outpatient clinics (survey 1, April 1997), two general practice
surgeries (survey 2, May 1997), and one general practice surgery (survey 3,
October 1997). DESIGN: Patients completed a questionnaire while waiting for their
clinical consultation. Attitude scores were measured on an 11-category Likert
scale ranging from -5 (definitely would not) to +5 (definitely would) for
acceptance of proposed medication or surgery. PARTICIPANTS: 85 (participation
rate, 85%), 77 (94%) and 95 (97%) in surveys 1, 2 and 3, respectively. Surveys 1
and 2 constituted the primary study group (n = 162). Patients aged > or = 50
years or reporting heart disease were excluded from the HRT analyses; patients
aged > or = 65 years were excluded from the THROM and CABS analyses. RESULTS: The
median attitude scores for HRT (n = 58), THROM and CABS (n = 111) were -2.95 (95%
CI, -5 to -2.1), -0.5 (95% CI, -0.9 to 0) and -0.1 (95% CI, -0.5 to +1.3),
respectively. Decreasing the risk-benefit ratio fourfold for HRT in survey 3 (n =
68) increased the median score to -0.75 (95% CI, -2.3 to 0). CONCLUSIONS:
Patients do not view favourably the risk-benefit ratio of the three surveyed
medical interventions. These attitudes may present a major impediment to most
primary prevention programs.
PMID- 10682009
TI - Survival of patients with colorectal cancer detected by a community screening
program.
AB - OBJECTIVE: To determine survival rates for people with colorectal cancer detected
through Bowelscan, a community screening program. DESIGN: Survey of data from
local medical practitioners, and comparison with data from State cancer
registries. SUBJECTS AND SETTING: 249 people with colorectal cancer detected
after faecal occult blood screening in north-eastern New South Wales, 1987-1996.
Follow-up was in 1998-1999. MAIN OUTCOME MEASURES: Five-year survival rates and
relative survival ratios. RESULTS: Five-year survival rates for the screen
detected cancer patients were 90% for those with Dukes' stage A cancers, 75% for
Dukes' B, 52% for Dukes' C and 0 for Dukes' D (although one person with Dukes' D
cancer was living at four-year follow-up at the end of the study). Because of the
higher percentage of Dukes' A cases in the population whose cancer was detected
through screening, the resulting five-year relative survival ratio was
significantly better than for those recorded by New South Wales, South Australian
and Queensland cancer registries: 0.82 (95% confidence interval, 0.74-0.90)
compared to 0.59 (P < or = 0.001). CONCLUSIONS: The study supports the findings
of three overseas randomised trials that screening reduces mortality from
colorectal cancer. We estimate that screening 200,000 people would detect about
250 colorectal cancers and prevent as many as 55 deaths.
PMID- 10682010
TI - Concordance between use of proton pump inhibitors and prescribing guidelines.
AB - OBJECTIVE: To determine (i) the relationship between prescriptions for proton
pump inhibitors (PPIs) and upper gastrointestinal conditions, and (ii) compliance
with Pharmaceutical Benefits Scheme (PBS) prescribing guidelines for PPIs.
DESIGN: Drug utilisation evaluation. SETTING: 800-bed metropolitan teaching
hospital. PARTICIPANTS: 253 patients dispensed PPIs from the hospital pharmacy
over five consecutive weeks (11 January to 15 February 1999). MAIN OUTCOME
MEASURES: Recorded gastrointestinal conditions; previous trial of H2-antagonist
therapy; compliance with PBS criteria for prescribing PPIs. RESULTS: Seventy
patients (27.7%) had no appropriate upper gastrointestinal tract investigations,
and 62 patients (24%) did not receive an adequate trial of H2-antagonist therapy
before the commencement of a PPI. The major indications for use of PPIs in
investigated patients were gastro-oesophageal reflux in 99 (54%) and peptic ulcer
disease in 30 (16.4%). In only 57 patients (22.5%) did PPI prescriptions comply
with PBS prescribing guidelines. Clinical indications that failed to meet
prescribing criteria included milder forms of gastro-oesophageal reflux,
gastritis/duodenitis, and non-specific dyspepsia with normal endoscopy results.
CONCLUSION: Drug utilisation data indicate widespread use of PPIs outside current
prescribing guidelines. Many patients have not had relevant investigations and/or
an adequate trial of H2-antagonist therapy. These findings explain the
considerable hospital expenditure on PPIs.
PMID- 10682011
TI - Fulminant hepatitis A in indigenous children in north Queensland.
AB - Since 1993, three Indigenous children in north Queensland have died of fulminant
hepatitis A. Even if the children had been able to undergo liver transplantation,
prolonged immunosuppressant therapy and the likelihood of opportunistic
infections would inevitably have jeopardised any chance of long-term survival. As
hepatitis A has become a leading infectious cause of death in young Indigenous
children in north Queensland, hepatitis A vaccine has recently been introduced
into the vaccination schedule for these children.
PMID- 10682012
TI - General practice computerisation: lessons from the United Kingdom.
PMID- 10682013
TI - An integrated electronic health record and information system for Australia?
PMID- 10682014
TI - Integrated electronic health records and patient privacy: possible benefits but
real dangers.
PMID- 10682015
TI - 2020 vision: looking to the future.
PMID- 10682016
TI - More than minding the machine.
PMID- 10682017
TI - "Eyes-open optimism": one view of the future for physicians.
PMID- 10682018
TI - Fallopian tube carcinoma detected by ThinPrep cytology smear.
PMID- 10682019
TI - Computed tomography screening for coronary disease.
PMID- 10682020
TI - Computed tomography screening for coronary disease.
PMID- 10682021
TI - Computed tomography screening for coronary disease.
PMID- 10682022
TI - Stable angina pectoris: treatment and referral options.
PMID- 10682024
TI - Vancomycin-resistant enterococci and use of avoparcin in animal feed: is there a
link?
PMID- 10682023
TI - Vancomycin-resistant enterococci: seek and ye shall find.
PMID- 10682025
TI - Vibrio cholerae in Victoria.
PMID- 10682026
TI - Androgen treatment in women.
PMID- 10682027
TI - Women's role and satisfaction in the decision to have a caesarean section.
PMID- 10682028
TI - How best to fix a broken hip.
PMID- 10682029
TI - Short and curly.
PMID- 10682030
TI - [Prevention of venous thromboembolism in polytraumatized patients. Epidemiology
and importance].
AB - OBJECTIVE: Unfractionated heparin, low-molecular-weight heparin (LMWH),
mechanical compression, and vena cava filters are part of a large panel of
chemical or physical methods proposed to trauma patients as prophylaxis against
venous thromboembolism. This prophylactic strategy is based on a 1961 autopsy
survey showing a 16.6% rate of pulmonary embolism in this population. The
objective of this study was to assess the incidence of deep venous thrombosis
(DVT) and pulmonary embolism (PE) in multiple trauma patients. METHODS: A Medline
and Current Contents search was conducted for prospective studies including
trauma patients with ISS > 9 whose incidence of DVT and PE was evaluated by
contrast venography and/or duplex scan and by ventilation/perfusion lung scan
and/or pulmonary angiography and/or autopsy, respectively. RESULTS: Twelve
studies met the selection criteria for DVT. Among the global population of 2,374
trauma patients (14% of all admissions) 47% suffered lower limb injury and 17%
had severe head injury. Overall incidence of DVT was about 20%. It was about 38%
in patients without prophylaxis (range 2 to 61.5%) and about 13% in patients with
prophylaxis (range 0.8 to 37%). Similar variations were observed for proximal
DVT. In comparative studies (unfractionated heparin versus LMWH or versus
mechanical compression devices), the incidence of thromboembolic events varied
from 3.2 to 44% in patients given unfractionated heparin, 0.8 to 31% in those
given LMWH, and 3.1% to 12% with mechanical compression. Thirteen studies met the
selection criteria for PE and included an overall population of 4,245 trauma
patients where the diagnosis of PE was suspected only if the patient had clinical
signs. The incidence of PE and fatal PE was about 1.4% and 0.3% respectively.
Only one study systematically studied the presence of PE and showed an incidence
of 18.7% for PE in a population of 32 patients. DISCUSSION: The current
literature reports wide variability in methodology, characteristics of the study
population and prophylaxis. These differences explain the wide variability from
one study to another in the risk factors for venous thrombosis identified by
univariate and multivariate analysis. CONCLUSION: Current methodological
imperfections make it impossible to correctly assess the incidence of DVT and PE
in the multiple trauma population. Studies with a rigorous methodology using a
precise stratification of the trauma injuries are required to determine the real
risk for DVT/PE in trauma patients and to assess the impact of early systematic
prophylaxis.
PMID- 10682031
TI - [Administration of tobramycin aerosols in patients with nosocomial pneumonia: a
preliminary study].
AB - OBJECTIVE: The aim of this study was to assess renal and respiratory tolerance of
aerosolized tobramycin in intubated and mechanically ventilated patients with
nosocomial pneumonia. PATIENTS AND METHODS: This was a multicenter, randomized,
double-blind, placebo controlled study. Thirty-eight mechanically ventilated
patients with documented nosocomial pneumonia were included. Patients treated
with intravenous betalactam and tobramycin were randomly allocated to receive
aerosolized tobramycin (6 mg/kg/day, n = 21) or placebo (n = 17). The aerosol was
administered via a pneumatic nebulizer once a day for 5 days. RESULTS:
Respiratory tolerance was good in all but two patients. No acute renal failure
occurred. By day 10, 7 patients in the tobramycin group (35%) had been extubated
versus 3 in the placebo group (18.5%, p = 0.18). By day 28, 6 patients had died
(2 in the tobramycin group and 4 in the placebo group, p = 0.23). CONCLUSION:
Aerosolized tobramycin was well tolerated in ventilated patients with documented
nosocomial pneumonia.
PMID- 10682032
TI - [Sudden-onset coma revealing neurosarcoidosis].
AB - BACKGROUND: Central nervous system involvement is uncommon in sarcoidosis,
particularly in cases discovered in circumstances described in our case. CASE
REPORT: A 38-year-old man with a history of pulmonary sarcoidosis diagnosed in
1991 was treated by budesonide. The clinical course was generally favorable until
1995 when the patient complained of rapid onset headache which suddenly
progressed to coma. The patient died 26 days later. DISCUSSION: The course of the
neurological manifestations was remarkable in this case of neurosarcoidosis. The
anatomic localization was also unusual with 3 distinct foci outside the central
nervous system.
PMID- 10682033
TI - [Manchineel dermatitis].
PMID- 10682034
TI - [Troponin Ic in acute myocarditis in children].
PMID- 10682035
TI - [Basedow's disease and interferon for hepatitis C. Recurrence as Basedow's
ophthalmopathy after interferon reintroduction].
PMID- 10682036
TI - [Flu and antiviral agents....].
PMID- 10682037
TI - [Anti-ulcer drugs. Indications in adults. French Agency of the Safety of Health
Products].
PMID- 10682038
TI - [Indications for anti-ulcer drugs in adults].
PMID- 10682039
TI - [Impact: from nutrition to drug].
PMID- 10682040
TI - [The French pharmacovigilance system: structure and missions].
AB - THE NETWORK: The French pharmacovigilance system is composed of a network of 31
regional pharmacovigilance centers located in convenient proximity to health care
professionals. CAUSALITY ASSESSMENT: A causality assessment method is compulsory
for all persons involved in pharmacovigilance in order to assess the causal
relationship between an adverse effect and one or more drugs.
PHARMACOEPIDEMIOLOGY: If necessary, an additional evaluation of the causal
relationship is performed using pharmacoepidemiology methods. THE NATIONAL
COMMISSION: A technical committee and a National Commission of Pharmacovigilance
centralizes at the Agence Franciase de Securite Sanitaire (or AFSSAPS) and
assesses all data in order to provide consensual advise to the relevant
authorities on necessary measures, to prevent or reduce a drug-related adverse
effect.
PMID- 10682041
TI - [The European pharmacovigilance: regulatory aspects].
AB - ESTABLISHMENT: The European pharmacovigilance system has been operating since
1995 when the European Agency for the Evaluation of Medicinal Products as well as
two new European registration procedures were established. STRUCTURE: This system
is very similar to the French organization and is based on a decentralized
collection and validation of safety data by member states and a centralized
evaluation and decision making process at the European Agency for the Evaluation
of Medicinal Products performed by the Committee for Proprietary Medicinal
Products (CPMP) and its Pharmacovigilance Working Party. A EUROPEAN SYSTEM: In
light of the experience gained, the European pharmacovigilance system moved to an
interactive system which relies on a close cooperation between member states
ensuring the common evaluation and management of safety concerns.
PMID- 10682042
TI - [Incidence and prevalence of adverse drug reactions].
AB - FUNDAMENTAL DATA: Estimation of incidence and prevalence rates of adverse drug
reactions are necessary to assess the consequences and impact of these effects in
a population. HOSPITAL STUDIES: During the last 20 years, several studies
conducted in one or more departments of a single hospital have found incidence of
hospitalizations induced by adverse drug reactions between 2 and 8%. Three meta
analyses confirm these reports with incidence varying from 4.4 to 5.8% in
different countries and from 5.2 to 8.2% and from 2.37 to 3.6% in the United
States and Australia respectively. Two recent studies conducted by the French
pharmacovigilance regional centers on a representative sample of medical
departments in public hospitals found a prevalence of adverse drug reactions
between 4.2 and 22.1% (according to the type of department and hospital) and a
hospitalization incidence due to adverse drug reaction between 2.37 and 4.01%.
COMMUNITY STUDIES: In community medicine, few data are available. In general
medicine, the incidence would be 1.99 adverse effects per general practitioner
per day. The number of serious adverse drug reactions has been estimated at 0.01
per general practitioner per day. These numbers show the magnitude of adverse
drug reactions in terms of morbidity and mortality.
PMID- 10682043
TI - [Drug information and prescription guidance: role of regional centers of
pharmacovigilance].
AB - MISSIONS: Drug information is one of the missions of the French Regional Pharmaco
Vigilance Centers together with the evaluation of adverse drug reaction (ADR)
reports, expertise, teaching and research. SERVICES: Physicians and other health
professionals call their regional center (the address and phone numbers are on
the first pages of the Vidal, the French national drug compendium) for any kind
of information pertaining to adverse drug reactions or proper use of drugs such
as drug use in pregnancy or lactation. RELIABILITY: This information activity is
successful because of the competence and impartiality of the regional centers
which are based in university hospitals under an agreement signed with the French
Medicines Agency.
PMID- 10682044
TI - [Antibiotic strategy in an infectious diseases unit].
PMID- 10682045
TI - [Prevention of venous thromboembolism in a non-surgical medical ward. Proposed
indications for low molecular weight heparin].
AB - OBJECTIVE: The efficiency of venous thromboembolism prophylaxis with low
molecular weight heparins (LMWH) has not been established in non surgical
patients, so their official preventive use has been limited in France since 1995
to surgery. However, a survey conducted in 5 university hospitals in non surgical
patients showed that 21-29% of patients still received a LMWH prescription. It
seemed necessary to define the medical conditions for which the practical use of
these heparins would be justified. We contacted external experts to obtain a
consensus by using the Delphi method. METHODS: The Delphi method, created by the
"Rand Corporation" in the USA and used in medicine since the nineteen seventies,
is based on a light logistic, with questionnaires been sent by mail with a feed
back report A total of 48 experts were chosen by local staff teams in the 5
hospitals. For the 3 rounds, from March to October 1998, questions were devised
by a multicentred staff team. RESULTS: Among the 48 experts contacted, 32
completed the 3 questionnaires, 7 of them did for 2, and 43 did for at least one
questionnaire. The experts first defined a list of 12 risk or high risk
situations and 11 aggravating factors. For any high risk situation, prescription
is justified. For other cases, 2 risk situations are required, or one risk
situation with at least 2 aggravating factors, to justify a prescription. If no
risk situation is present, prescription is, according to experts, usually not
justified. CONCLUSION: The maximal agreement defines the situations in which one
use of low molecular weight heparins is proposed to prevent deep venous
thrombosis in non surgical inpatients, in most current hospital situations and
for more than 24 hours of hospitalization. Clinical trials are needed, to
validate their effectiveness and define the optimal dose in these indications. To
date, epidemiological studies should be conducted to evaluate the experts
proposals by estimating risk factors for deep venous thrombosis.
PMID- 10682046
TI - [Value of Holter ECG in the diagnosis of sleep apnea syndrome in patients with
massive obesity].
AB - OBJECTIVE: Assess the diagnostic contribution of cyclic nocturnal variations in
heart rate in sleep apnea syndrome. PATIENTS AND METHODS: Holter recordings
performed in a population of 30 patients with massive obesity defined as a body
mass index greater than 40 kg/m2 and sleep apnea syndrome defined by an apnea
index greater than 5 apneas per hour were analyzed retrospectively. The control
group was composed of 15 patients with massive obesity but without sleep apnea
syndrome. High variability in nocturnal heart rate was assessed using a visual
criterion defined as repeated episodes of progressive reduction in heart rate
followed by a sudden acceleration reaching a difference of 30 bpm between the
highest and lowest heart rate and occurring at least 5 times during one
consecutive hour of recording. RESULTS: Increased nocturnal variability in heart
rate was evidenced in all the patients with sleep apnea syndrome (30/30) but was
not observed in any of the control subjects (0/15). CONCLUSION: These results
suggest that Holter recordings can be a useful tool for the diagnosis of sleep
apnea syndrome.
PMID- 10682047
TI - [Panhypopituitarism secondary to pituitary metastases].
AB - BACKGROUND: Hypophyseal metastatic localizations are uncommon and rarely the
first expression of a primary cancer. We report an exceptional case revealed by
panhypopituitarism and diabetes insipidis. CASE REPORT: Brain MRI visualized an
intra- and suprasellar tumoral formation found to be a cribiform adenocarcinoma.
The primary tumor could not be identified. Despite radiotherapy, surgery and
chemotherapy combining carboplatin and etoposide, the tumor progressed with the
development of cervical and mediastinal nodes. The patient died one year after
onset of the clinical signs. DISCUSSION: Diagnosis of hypophyseal metastasis is
mainly based on indirect evidence: rapid course, invasion of neighboring
structures. Optimal management of these rare tumors remains to be determined.
PMID- 10682048
TI - [Recurrent infectious and metastatic cellulitis cause by Escherichia coli].
AB - BACKGROUND: We report a case of recurrent and metastatic infectious cellulitis
caused by Escherichi coli. CASE REPORT: A 79-year-old man with a history of
alcoholic cirrhosis and a myelodyplasia syndrome was hospitalized for skin rash
and inflammatory edema of the right leg associated with bullous and necrotic
lesions. Culture of a bulla puncture fluid grew E. coli. A two-drug intravenous
antibiotic regimen and surgical cleansing led to a favorable outcome in 3 weeks.
One week after withdrawal of the antibiotics, the patient developed a recurrent
erythematous and inflammatory lesion of the right flank. Blood culture grew E.
coli. The intravenous antibiotics were reinitiated immediately and provided rapid
regression of the skin signs. Search for a urinary or digestive tract neoplastic
focus was negative. DISCUSSION: E. coli cellulitis is a very uncommon usually
fatal condition. Clinicians should be aware of a possible association with
alcoholic cirrhosis. In case of recurrence, it is important to search for a
digestive, hepatobiliary or urinary tract focus. Broad spectrum empirical
antibiotic therapy must be initiated rapidly. Surgery is required in case of
necrotizing cellulitis whatever the infectious agent.
PMID- 10682049
TI - [Ketoacidosis as an initial sign of diabetes decompensated by a flare up of
Plasmodium falciparum infection].
PMID- 10682050
TI - [Fatal multiple organ failure in a homozygous sickle cell patient].
PMID- 10682051
TI - [Sural nerve palsy after stripping of the saphenous vein. 3 cases].
PMID- 10682052
TI - [Carpal tunnel syndrome: is corticosteroid infiltration sufficient to decompress
the median nerve?].
PMID- 10682053
TI - [Therapeutic management of HIV-infected subjects. Report of the expert group
under the direction of Prof. J.F. Delfraissy, 1999].
PMID- 10682054
TI - [Therapeutic management of HIU-infected persons. Interview with A, Sobel].
PMID- 10682055
TI - [Association of colon cancer and Hodgkin disease].
PMID- 10682056
TI - [Subcutaneous caffeine poisoning].
PMID- 10682057
TI - [Renal and hypertensive complications of extracorporeal lithotripsy].
AB - HISTOLOGICAL AND FUNCTIONAL CONSEQUENCES OF ESWL: Extracorporeal shock wave
litotripsy is now used for the treatment of about 90% of stones. Because of the
nonpunctual delivery of energy into the stone, a small volume of renal parenchyma
is injured, giving rise to a fibrous scar which can be visualized by
morphological techniques such as magnetic nuclear resonance. Isotopic techniques
point out a 15% reduction of renal plasma flow on the side of the litotripsy. For
a majority of patients, this alteration is transient. HYPERTENSION: In a few
cases, abrupt onset of transient hypertension has been reported in clear relation
with a compressive perirenal hematoma. The causal effect of ESWL on late
occurrence of permanent hypertension is however still uncertain, probably because
of the difficulty to show that this occurrence is not related to the older age of
the patient alone. The FDA sponsored multicentric study begun in 1993 should
solve this issue in the future. PATIENTS AT RISK: Recent articles suggest that
altered renal function prior to ESWL would predict late occurrence of
hypertension and worsening of renal failure. Furthermore, age and the resistance
index of arcuate or interlobular renal arteries (measured by Doppler) could help
to screen the patients at risk of developing hypertension. Practical attitude: In
practice, renal function and blood pressure should be carefully monitored in
patients aged over 60 and/or who have a serum creatinine > 300 mumol/l.
PMID- 10682058
TI - [Venous thromboembolism in pregnancy].
AB - A DUAL CHALLENGE: Pregnancy is a physiological state favoring the development of
venous thromboembolism and sometimes discloses a coagulation disorder. Due to the
presence of the fetus, suspected venous thromboembolism in a pregnant woman
raises a dual challenge for the clinician: confirmation of the clinically
suspected diagnosis using imaging techniques exposing the fetus to as little
radiation as possible, and adapted anticoagulant therapy taking into account the
teratogenic risk. MILD TO MODERATE DISEASE: Excepting exceptionally severe cases,
the only validated long-term treatment is continuous infusion heparin. However,
because of the difficulties inherent in the use and control of this type of
administration, most clinicians prefer low-molecular-weight heparins (LMWH)
although these pharmaceutical products have not acquired official approval for
this indication. PREVENTION: The optimal therapeutic approach for prevention of
venous thromboembolism in a pregnant woman with an acquired or hereditary
coagulation disorder or a history of venous thromboembolism remains to be
defined. New clinical trials are needed to validate the use of LMWH in this
indication and determine the therapeutic approach in certain risk situations and
at delivery.
PMID- 10682059
TI - [Multifactorial cardiovascular risk].
AB - IMPORTANCE OF RISK ASSESSMENT: The prevention of cardiovascular disease is a
major public health goal. Cardiovascular diseases are the number one cause of
mortality in industrialized countries and account for an important part of health
care expenditures. In this context, assessment of the cardiovascular risk for a
given subject based on epidemiological data and individual risk factors can be
used to determine his/her risk of ischemic heart disease or stroke. THE
FRAMINGHAM FORMULA: The most widely used assessment method is the Framingham
formula which integrates age, sex, blood pressure, smoking habits and presence or
not of diabetes. This formula gives an objective, reproducible estimation of the
cardiovascular risk and is a useful tool for therapeutic rationale and primary
and secondary prevention. INTEREST AND LIMITATIONS: This new global approach to
the individual patient has interesting practical and economic implications but
remains imperfect due to certain limitations (other risk factors not taken into
account because they are difficult to quantify or occurred recently). For daily
practice however, it provides a useful tool appreciated by clinicians and
patients.
PMID- 10682060
TI - [Effect of pregnancy, menopause and hormone substitution therapy on disseminated
systemic lupus erythematosus].
AB - EXACERBATIONS DURING PREGNANCY: Clinical and experimental data have clearly
evidenced the influence of hormones on the course of systemic lupus
erythematosus. In prospective studies of pregnant women, an exacerbation is
observed in 57% to 60% of the cases. It can be severe in 10% of the cases and
occur in the post partum in 7%. For most patients, the exacerbation is moderate
and has no unfavorable effect on the outcome of pregnancy. In case of renal
involvement, it is difficult to differentiate an intricated HELPP syndrome.
MARKERS AND RISK FACTORS: Low complement and elevated anti-DNA levels are
distinctive markers. Earlier renal involvement and hypertension are important
prognostic factors, particularly when the lupus begins during pregnancy. However,
when serum creatinine is lower than 100 mumol/l at pregnancy onset in patients in
remission, pregnancy does not alter renal function. An association with
antiphospholipid antibodies increases the risk for the fetus and the kidney
function. TREATMENT: Optimal treatment remains to be defined. Commonly, patients
are given aspirin, heparin in case of a history of thromboembolism, or both. The
rate of success currently exceeds 70%. The risk of thromboembolism in the peri or
post partum period requires anticoagulant treatment. Outside pregnancy: Ovulation
induction raises two risks: triggering a lupus flare-up and thrombosis,
particularly for patients with antiphospholipid antibodies. The influence of
menopause and hormone replacement therapy remains poorly understood.
PMID- 10682061
TI - [Antibiotic strategies in an intensive care service].
PMID- 10682062
TI - Water channel AQP-1 in the primary cell culture of rat peritoneum.
AB - To analyze the regulation of water channels in the peritoneum, we tried to
establish a primary mesothelial cell culture system. Male Sprague-Dawley rats
weighing about 250 g were anesthetized, and 10 mL of phosphate-buffered saline
(PBS) containing 0.25% trypsin and 1 mmol/L ethylenediamine tetraacetic acid
(EDTA) was infused into the peritoneal cavity for 15 minutes. Sediments from the
recovered fluid were cultured in medium M199 supplemented with 10% fetal bovine
serum (FBS). The culture was succeeded 4-6 times before experiments commenced.
After exposure to the test medium, RNA was extracted and subjected to reverse
transcriptase polymerase chain reaction (RT-PCR) for 10-19 cycles, then was
measured by Southern blot analysis with a digoxin-labeled probe. Cultured cells
were positively stained with mouse monoclonal anti-cytokeratin antibody,
confirming their characteristics as mesothelial cells. Aquaporin-1 (AQP-1)
message in the cultured cells increased with increases in glucose and mannitol
concentrations when beta-actin message was used as an internal control.
Tranexamic acid effected no change in AQP-1 message in the cultured mesothelial
cells. This system offers potential as a simple approach to test the effects of
osmolytes, cytokines, and vasoactive hormones on aquaporin expression and water
transport in the peritoneum.
PMID- 10682063
TI - Effects of chlorpromazine or diltiazem given intraperitoneally alone or in
combination on peritoneal transport of solute and water.
AB - Calcium channel blocker given intraperitoneally (i.p.) in rats was reported to
increase urea D/P ratio without protein loss. Chlorpromazine (CP) given i.p. in
humans was reported to increase ultrafiltration (UF) and urea clearance. We
studied the effects of i.p. Diltiazem (DZ) (15 mg/kg) and i.p. chlorpromazine
(0.25 mg/L dialysate)--given alone or in combination--on urea D/P ratio,
dialysate protein (Dpro), glucose concentration (Dg), UF, and drainage volume
(Vd). Six male Sprague-Dawley rats were studied. The rats underwent 21
consecutive 30-minute exchanges with 15 mL of 1.5% of Dianeal solution (Baxter
Healthcare Inc., Deerfield, Illinois, U.S.A.). DZ or CP was added to the dialysis
solution during exchanges 4-6 and 10-12. During exchange 16-18 both DZ and CP
were added to the dialysis solution. Exchanges 1-3, 7-9, 13-15, and 19-21 were
control exchanges performed with 1.5% Dianeal solution alone. The mean weight of
the rats was 541.6 +/- 44 g. The animals' blood pressure remained stable during
the study period. An increase in D/Purea ratio was observed with DZ, with CP, and
with the two drugs in combination, without increase in dialysate protein loss. An
increase in UF with a decrease in D/D0 was observed with DZ, with CP, and with
the two drugs in combination, suggesting a mechanism other than osmotic gradient-
such as increased blood flow or decreased surface tension.
PMID- 10682064
TI - Decreased in vitro formation of AGEs with extraneal solution compared to dextrose
containing peritoneal dialysis solutions.
AB - Extraneal peritoneal dialysis (PD) solution (Baxter Healthcare, Deerfield,
Illinois, U.S.A.) contains glucose polymer (icodextrin) as an osmotic agent in
place of dextrose. We investigated the ability of Extraneal to form advanced
glycation end products (AGEs) in vitro compared to standard PD solutions
containing dextrose. Extraneal, Dianeal PD-2 [1.5%, 2.5%, or 4.25% dextrose
(Baxter Healthcare)], or phosphate buffered saline (PBS) were incubated for 45
days with human serum albumin (HSA) or type IV collagen. AGE formation was
measured by spectrofluorometry using excitation at 350 nm and emission at 430 nm.
Solutions were also incubated with collagen affixed to plastic, simulating matrix
collagen in the peritoneal membrane. In addition, AGE formation was assessed
using icodextrin metabolites (maltose, maltotriose, and maltotetraose) at
concentrations normally found in the plasma of patients treated using icodextrin.
For PD solutions incubated with albumin, the relative order of AGE formation was:
4.25% dextrose > 2.5% dextrose > 1.5% dextrose > Extraneal. For incubations with
collagen (in solution or affixed to plastic), AGE formation was greatest for
4.25% dextrose, intermediate for Extraneal and 2.5% dextrose, and lowest for 1.5%
dextrose. Incubation of icodextrin metabolites with albumin for 45 days did not
result in appreciable AGE formation. These results confirm that solutions
containing icodextrin result in less in vitro AGE formation than do high dextrose
solutions. The results also suggest that Extraneal may lead to improved solution
biocompatibility in vivo.
PMID- 10682065
TI - Effect of icodextrin peritoneal dialysis solution on cell proliferation in vitro.
AB - Peritoneal dialysis solutions containing icodextrin are ideal for providing
sustained ultrafiltration during long dwells, and they have replaced high glucose
for long dwells in some patients. The biocompatibility of these solutions,
especially in regard to glucose degradation products, has not been studied in
depth. The object of this study was to compare the effects of commercially
available dextrose-containing dialysis solutions to those of icodextrin
containing solutions on fibroblast proliferation in vitro. We measured the effect
of solutions on cell growth by exposing murine fibroblasts to pH-adjusted test
solutions mixed with culture medium, and by comparing cell growth to growth in
culture medium only. No statistical difference was observed in the growth of
cells exposed to heat-sterilized Extraneal [7.5% icodextrin (Baxter Healthcare,
Deerfield, Illinois, U.S.A.)], heat-sterilized Dianeal [1.5% dextrose (Baxter
Healthcare)], or filter-sterilized Dianeal [4.25% dextrose (Baxter Healthcare].
Also, no difference was observed in the growth of fibroblasts exposed to heat
sterilized Extraneal or to filter-sterilized Extraneal, but heat-sterilized
Dianeal [4.25% dextrose (Baxter Healthcare)] caused a significant reduction in
cell growth. Glucose degradation products (GDPs) are known to contribute to
reduced cell growth in vitro. Extraneal had lower levels of the GDP acetaldehyde
compared to Dianeal (2.5% or 4.25% dextrose). The results demonstrate enhanced in
vitro biocompatibility characteristics for Extraneal, possibly related to low GDP
levels in Extraneal.
PMID- 10682066
TI - Peritoneal fluid kinetics: comparison between polyglucose solution and albumin
solution.
AB - Polyglucose (PG) solution has been shown to be capable of inducing peritoneal
ultrafiltration despite its hypo-osmolality. However, the mechanism of osmosis by
PG is not clear. In this study, we compared the fluid kinetics of albumin (ALB)
solution (thought to be an ideal solution that should induce ultrafiltration
through colloid osmosis) and PG solution. A 4-hour dwell study with frequent
sampling was conducted in Sprague-Dawley rats (six rats in each group). The study
used 25 mL of dialysate buffer, 10% ALB dialysis solution, 15% ALB dialysis
solution, 20% ALB dialysis solution, or 7.5% PG solution, with 131I albumin as an
intraperitoneal volume marker. All solutions were prepared by adding ALB or PG to
a base dialysis solution (without osmotic agent). The initial osmolality values
of the five solutions were 250 mOsm/kg, 284 mOsm/kg, 300 mOsm/kg, 320 mOsm/kg,
and 280 mOsm/kg, and the dialysate drainage volumes at 4 hours were 17.0 +/- 0.8
mL, 22.4 +/- 0.8 mL, 25.4 +/- 0.6 mL, 27.3 +/- 0.9 mL, and 26.3 +/- 0.6 mL
(buffer, 10% ALB, 15% ALB, 20% ALB, and 7.5% PG groups, respectively). The higher
initial osmolality in the ALB groups was partially due to the sodium content in
the ALB powder. The intraperitoneal volume was decreasing in the 10% ALB group,
rather stable in the 15% ALB group, but slowly increasing in the 20% ALB group.
In the PG group, intraperitoneal volume decreased initially and then started to
increase after 2 hours. This pattern was closely related to the increase in the
dialysate osmolality (to higher than plasma level). At 4 hours, the dialysate
osmolality was significantly higher (and higher than plasma level) in the PG
group as compared to all the ALB groups. No differences in peritoneal fluid
absorption rate were observed among the four treatment groups. In the 15% ALB and
20% ALB groups, the transcapillary ultrafiltration rate (Qu) was lower in the
later part of the dwell than in the initial part of the dwell; in the PG group,
the opposite pattern was observed. Our results suggest that the osmosis of
albumin dialysis solution is different from the osmosis of polyglucose solution.
Polyglucose solution induces net ultrafiltration only when the dialysate
osmolality increase to higher than plasma level, suggesting that degradation of
polyglucose may be important for effective ultrafiltration.
PMID- 10682067
TI - Changes in peritoneal membrane after continuous ambulatory peritoneal dialysis--a
histopathological study.
AB - Peritoneal membrane changes in continuous ambulatory peritoneal dialysis (CAPD)
patients have been widely described but poorly classified. Our aim was to
identify the morphological changes occurring after CAPD treatment. To this end,
17 biopsies of parietal peritoneum (1 cm in diameter) were withdrawn at least 5
cm from the catheter entry hole and stained with Van Gieson, hematoxylin-eosin,
trichrome, and some immunohistochemical stains: keratin, vimentin, CD34, CD20,
CD4, CD8, desmin, and collagen IV. The morphology of mesothelium, vessels, and
basement membrane (BM) of mesothelium and vessels, the presence of inflammatory
cells, fibrin, and calcifications, and the distribution and thickness of
submesothelial tissue were evaluated. Patients were divided into three groups
according to the thickness of the sclerotic band replacing mesothelium: group 1,
band up to 40 microns; group 2, band less than 40 microns; group 3, no sclerotic
band. The main histopathological alterations noted were: loss of mesothelium;
sclerotic alteration of vessels or duplication of BM; presence of myofibroblasts;
and presence of inflammatory cells (sparse, focal, or perivascular), mainly
represented by macrophages and CD4+ lymphocytes. No significant qualitative
differences were observed between the three groups. In conclusion, the variable
histological changes in peritoneal membrane suggest a routine peritoneal biopsy
in any surgical procedure to better understand pathological changes in the course
of CAPD treatment.
PMID- 10682068
TI - Evaluation of the effect of uremia on peritoneal permeability in an experimental
model of continuous ambulatory peritoneal dialysis in anephric rats.
AB - Anephric rats were maintained on continuous ambulatory peritoneal dialysis
(CAPD). Peritoneal permeability was assessed during a standard 4-hour peritoneal
equilibration test (PET) performed with Dianeal 3.86% (Baxter Healthcare,
Deerfield, Illinois, U.S.A.). The effect of uremia on peritoneal permeability was
evaluated in an experimental protocol in which each animal served as its own
control. In each rat, PET1 (control) was performed before removal of kidneys and
PET2 (uremia) was performed four days after removal of kidneys. Net
ultrafiltration during a 4-hour exchange with Dianeal 3.86% was higher during
PET1 (3.8 +/- 2.3 mL) than during PET2 (-1.3 +/- 3.3 mL), p < 0.05. Peritoneal
permeability to urea and glucose was similar in both series. Transperitoneal
equilibration of creatinine concentration was faster in uremic animals: D/P at 4
hours was 0.94 +/- 0.06 during PET2 versus 0.77 +/- 0.08 during PET1, p < 0.001.
The opposite difference was seen for total protein: D/Px 1000 after a 4-hour
dwell was 51.4 +/- 19.8 during PET2 versus 70.3 +/- 12.9 during PET1, p < 0.05.
Our results show that uremia modifies the permeability of the peritoneum to both
water and solutes.
PMID- 10682069
TI - Peritoneal kinetics of cancer antigen 125 in peritoneal dialysis patients: the
relationship with peritoneal outcome.
AB - Cancer antigen 125 (CA125) is a mesothelial product that has been directly
related with mesothelial bulk in peritoneal dialysis (PD) patients. Here, we
evaluate CA125 levels in peritoneal effluent over time on PD, and relate them to
changes in peritoneal function. We analyzed 27 peritoneal kinetic studies in 20
stable PD patients. Three patients dropped out of PD for peritoneal membrane
failure after the last kinetic study, and six patients required a peritoneal rest
period as treatment for membrane failure type I. We recorded the standardized
daily ultrafiltration capacity, net ultrafiltration during the kinetic study,
peritoneal mass transfer coefficients, time from onset of PD, and incidence of
peritonitis prior to the study. A linear increase in CA125 levels over time was
observed, and a strong correlation appears among the levels at different dwell
times (r: 0.85-0.98, p < 0.05). At 180 minutes, the mean CA125 concentration was
48.5 +/- 39.7 U/mL. We observed significant differences in CA125 levels in
effluent between the group of patients who later required a peritoneal rest
period and the group of stable patients (27.7 +/- 26.3 U/mL vs 55.7 +/- 41.5 U/mL
respectively, p < 0.05). Patients who left PD showed lower CA125 levels in
effluent (31.4 +/- 30.6 U/mL vs 52.3 +/- 41.1 U/mL, p < 0.1). No correlation was
seen between CA125 levels in effluent and time on PD, episodes of peritonitis,
accumulated days of peritoneal inflammation, ultrafiltration capacity, or urea
and creatinine mass transfer coefficients (MTCs). In conclusion, we believe that
serial determinations of peritoneal effluent CA125 levels may help in the early
identification of patients who show abnormal responses to peritoneal dialysis or
its complications.
PMID- 10682070
TI - Evaluation of changes in serum and dialysate levels of cancer antigen 125 in
stable continuous ambulatory peritoneal dialysis patients.
AB - To estimate the relationship between changes in the concentration of cancer
antigen 125 (CA125) and peritoneal membrane kinetics, the permeability
characteristics of 44 continuous ambulatory peritoneal dialysis (CAPD) patients
who had been treated with peritoneal dialysis for at least six months were
prospectively evaluated. Twenty-seven males (age 66 +/- 6 years, duration of CAPD
35.5 +/- 29 months) and seventeen females (age 63.7 +/- 9 years, duration of CAPD
47.7 +/- 32 months) were evaluated. Peritoneal equilibration test (PET) data and
Adequest (Baxter Healthcare Corporation, Deerfield, Illinois, U.S.A.) data were
analyzed in all patients over a 12-month period, while CA125 levels were measured
in blood and dialysate samples. No statistically significant correlations were
seen between the patients' age, sex, or peritonitis incidence rates, and serum
and dialysate levels of CA125. Dialysate-to-plasma ratio (D/P) of small solutes
at 0 and 240 minutes also showed no statistical correlation. Statistical analysis
revealed a statistically significant negative correlation (r = -0.33, p = 0.035)
between dialysate CA125 and duration of CAPD. The statistically significant
difference found between dialysate CA125 concentrations at 0 minutes and 240
minutes (2.32 +/- 1.3 U/mL vs 9.08 +/- 6.8 U/mL, p < 0.0001), means that CA125
concentration increases with longer dwell time. These results suggest that the
duration of CAPD clearly affects dialysate CA125 concentrations. CA125 may
therefore be used as a useful marker to evaluate the mesothelial cell mass in
longitudinal follow-up.
PMID- 10682071
TI - Clinical importance of intraperitoneal pressure in peritoneal dialysis and
measures to counteract its effect on net ultrafiltration.
AB - Experiments in animals and in humans have shown that fluid loss from the
peritoneal cavity to the body increases with large increments in the
intraperitoneal hydrostatic pressure (IPP). We have demonstrated previously that
much of this fluid loss occurs to the abdominal wall and is driven by the
hydrostatic pressure gradient (i.p. pressure-skin pressure) that develops across
the wall whenever therapeutic or pathologic volumes of fluid reside in the
cavity. We hypothesized that eliminating the pressure difference across the wall
by applying an equal and opposite pressure [abdominal counterpressure (ACP)]
would decrease fluid movement into the wall and decrease fluid movement from the
cavity. In addition, we hypothesized that net ultrafiltration or net fluid
recovery would increase with ACP. To address these hypotheses, we dialyzed rats
for 3 hours in the supine position at constant levels of IPP (4, 6, and 8 cmH2O)
with isotonic or hypertonic dialysis solutions containing a protein marker of
fluid movement. We measured total fluid loss, fluid marker concentration in the
abdominal wall, and lymph flow. In separate animals, we repeated the experiments
with ACP. Total fluid loss as determined by protein clearance and fluid marker
deposition in the abdominal wall was decreased in all experiments. Lymph flow was
unchanged by ACP. While ACP increased the net fluid recovery in isotonic
dialysis, no change was observed in the hypertonic case. Analogous experiments
were carried out in six dialysis patients with or without ACP during a 4-hour
dialysis with 1.5% dextrose solution performed in the supine position at i.p.
hydrostatic pressure of 4-6 cmH2O. No significant difference was noted in the
measured net ultrafiltration between control and ACP studies. We conclude that
the careful application of ACP does decrease fluid loss (particularly to the
abdominal wall) during isotonic or hypertonic dialysis in the rat. However, ACP
results in improved fluid recovery only with isotonic dialysis in rats and has no
effect on the recovery of fluid during peritoneal dialysis in humans.
PMID- 10682072
TI - Vasodilatation by intraperitoneal addition of nitroprusside is not a model for
high peritoneal transport.
AB - It has been suggested that the peritoneal capillary is the major determinant for
peritoneal fluid transport and that an increase in the number of peritoneal
capillaries may be the reason for an increased peritoneal transport rate. In this
study, we investigated the impact on peritoneal fluid and solute transport of
vasodilatation (which may increase the number of perfused capillaries) by
intraperitoneal addition of nitroprusside. A 4-hour dwell was performed in four
groups of Sprague-Dawley rats (4-8 rats in each group) with 131I albumin as an
intraperitoneal volume marker. Nitroprusside at concentrations of 0% (control),
0.0005%, 0.001%, and 0.002% was added to the 3.86% glucose solution before
intraperitoneal infusion. Net ultrafiltration (NUF) was 13.2 +/- 0.6 mL, 14.5 +/-
0.7 mL, 13.4 +/- 0.9 mL, and 6.3 +/- 2.0 mL for the control group and the
0.0005%, 0.001%, and 0.002% nitroprusside groups, respectively. No significant
differences in peritoneal fluid absorption rate (KE) were observed among the four
groups. The intraperitoneal volume, transcapillary ultrafiltration rate (Qu), and
peritoneal small-solute transport rate (glucose and urea) as assessed by
diffusive mass transfer coefficient were significantly higher or tended to be
higher in the 0.0005% nitroprusside group as compared to control. However, with
further increase in the dose of nitroprusside, these parameters started to
decrease as compared to the 0.0005% nitroprusside group, and NUF was
significantly lower in the 0.002% nitroprusside group, conceivably suggesting a
reduction in blood flow owing to the systemic effects of nitroprusside. Our study
showed that: (1) a low dose of nitroprusside increased the peritoneal small
solute transport rate, but did not decrease peritoneal transcapillary
ultrafiltration rate; (2) although a high dose of nitroprusside decreased
peritoneal fluid removal, the decrease was not due to an increased small-solute
transport rate, but more likely to a significant drop in peritoneal blood flow;
(3) vasodilatation by nitroprusside did not change peritoneal fluid absorption
rate. Overall, vasodilatation does not seem to produce a pattern of peritoneal
fluid kinetics similar to that seen in high transporters, who have a higher
peritoneal transport rate, lower transcapillary ultrafiltration rate, and higher
peritoneal fluid absorption rate.
PMID- 10682073
TI - Use of bolus intraperitoneal iron dextran in continuous ambulatory peritoneal
dialysis or continuous cyclic peritoneal dialysis patients receiving recombinant
human erythropoietin.
AB - Impaired erythropoiesis in continuous ambulatory peritoneal dialysis (CAPD) or
continuous cyclic peritoneal dialysis (CCPD) patients receiving recombinant human
erythropoietin (rHuEPO) is most often secondary to iron deficiency, either as a
result of poor intestinal absorption or failure to take oral supplements as
prescribed. The inconvenience of giving intravenous (i.v.) iron dextran (ID) to
CAPD/CCPD patients precluded its use in this population. We therefore examined
the efficacy of bolus intraperitoneal (i.p.) iron dextran (1000 mg) on
erythropoiesis in a pilot study of 14 CAPD/CCPD patients. The patients ranged in
age from 23-81 years, and all had iron deficiency (transferrin saturation 6%-23%;
mean: 15.2% +/- 1.34%). Of the 14 patients studied, 13 were receiving rHuEPO. Pre
treatment hematocrit (Hct) ranged from 21%-38% (mean: 30.2% +/- 1.37%). After
infusion of 2 L Dianeal (Baxter Healthcare Corp., Deerfield, Illinois, U.S.A.),
500 mg of undiluted ID was administered directly into the Tenckhoff catheter and
subsequently flushed with 30 mm3 normal saline. The peritoneal dialysis (PD)
exchange containing ID then dwelled for a period not < 6 hours before standard PD
resumed. A second 500 mg dose ID was given to each patient by the same protocol 3
86 days later (mean: 14 days). No complications were seen. No patient complained
of abdominal pain or other subjective symptoms during infusion or during the
dwell. Repeat iron studies done 1-7 months post ID (mean: 2.8 months) showed a
1.1-fold to 4.9-fold increase (mean: 1.4-fold) in mean iron levels (40.4 +/- 3.9
mg/dL versus 57.5 +/- 5.5 mg/dL, p = 0.036); a 1.1-fold to 5.2-fold increase
(mean: 1.6-fold) in mean transferrin saturation (15.2% +/- 1.3% versus 24.5% +/-
2.6%, p = 0.008); a 1.01-fold to 1.60-fold increase (mean: 1.12-fold) in mean Hct
(30.2% +/- 1.37% versus 33.8% +/- 1.5%; p = 0.042). The mean dose of rHuEPO was
statistically unchanged (170.0 +/- 47.4 U/kg body weight versus 178.8 +/- 49.6
U/kg body weight per week; p = 0.841). Peritoneal equilibration test (PET) score
1-4 months post ID (mean: 2 months) was 0.778 +/- 0.02 compared with a PET score
at baseline of 0.767 +/- 0.03 (p = 0.734). No significant delta was observed in
blood urea nitrogen (BUN) or creatinine values. We conclude that use of bolus
i.p. ID is safe, effective, and convenient, and demonstrates no short-term
negative effect on peritoneal membrane integrity. Long-term effects have yet to
be determined.
PMID- 10682074
TI - Correction of sodium sieving for diffusion from the circulation.
AB - Transcellular water transport (TCWT) can be estimated by Na- sieving. However,
the assumption that the initial Na+ dialysate concentration (D0) is equal to the
initial plasma concentration (P0) is not true for each patient. The difference
leads to Na+ diffusion from the circulation to the dialysate, which diminishes
the Na+ sieving. A model was developed to distinguish transcellular water
transport from Na+ diffusion. We previously found evidence that the mass transfer
area coefficient of urate (MTACurate) was similar to the MTACNa+. The MTAC is the
product of the elimination constant (ke) and the volume of distribution (VD), the
mean intraperitoneal volume. Because VD is known, the ke Na+ in each patient can
be equated with the ke urate. The Na+ mass transfer from the circulation to the
dialysate by diffusion can then be calculated for any time point during a dwell
(Dt). Dt was subtracted from the measured Na+ dialysate concentration at 60
minutes. The corrected D/P Na+ then represents the actual Na+ sieving. Using
3.86% glucose dialysate, this approach was investigated in 15 stable peritoneal
dialysis (PD) patients (normUF) and in 9 PD patients with low ultrafiltration
(lowUF, < 400 mL/4 hours). The MTACurate was calculated according to Waniewski
(W) and according to the Garred model (G). Similar calculations were also
performed for the MTAC of creatinine (MTACcreat). Initial D/P Na+ was not
different between the groups. When no diffusion correction was made, D/P60 Na+ in
the lowUF group (median 0.898, range 0.870-0.949) was significantly higher (p <
0.025) than D/P60 Na+ in the normUF group (median 0.881, range 0.816-0.899). The
difference disappeared after diffusion correction regardless of the correction
model applied. However, at 240 minutes, D/P Na+ in the normUF group was
significantly lower than in the lowUF group (median 0.880, range 0.839-0.952 vs
median 0.942, range 0.866-0.987; p < 0.004). Even after correction, D/P Na+ in
the normUF group was significantly lower: 0.847 normUF versus 0.893 lowUF
(Wurate, p < 0.005); and 0.842 normUF versus 0.890 lowUF (Gcreat, p < 0.003). The
correlation between the Wurate (the best theoretical diffusion correction) and
Gcreat (the least) was: y = 0.99x + 0.0037. Furthermore, Bland and Altman
analyses of Wurate and Gcreat at both 60 and 240 minutes resulted in random
distribution around the means, with a slight overestimation in relation to the
magnitude of Gcreat, as was expected. Gcreat can be used to make an accurate
estimation of the contribution of Na+ diffusion in the time course of D/P Na+. It
provides a simple way to more precisely determine Na+ sieving, and therefore
TCWT. In conclusion, to avoid overestimation of impaired channel-mediated water
transport, a Na+ diffusion correction should be made when D0 is not equal to P0
or in the case of a large vascular surface area.
PMID- 10682075
TI - Prevalence of gastroesophageal reflux disease in peritoneal dialysis and
hemodialysis patients.
AB - The prevalence of gastrointestinal reflux disease (GERD) in hemodialysis (HD) and
peritoneal dialysis (PD) patients was assessed at a single center with a self
administered questionnaire previously used in a general population. It defines
(GERD as the presence of heartburn or acid regurgitation, or both. Risk factors
for GERD and GERD-associated symptoms were also evaluated. In the studied
population, 29.7% of patients had frequent GERD (heartburn, acid regurgitation,
or both symptoms weekly). Frequent GERD was reported by 44.7% of PD patients
versus the 18.9% reported by HD patients and the 19.8% reported by the general
population. PD and HD patients had similar GERD severity scores [2.3 +/- 0.7 vs
1.9 +/- 0.8, mean +/- standard deviation (SD)]. PD and HD patients reported
atypical GERD symptoms at rates similar to those reported by the general
population, but having GERD made some atypical GERD symptoms more likely (p <
0.05, Fisher's exact test). In a logistic model, age < 60 [odds ratio (OR) 5.6,
confidence interval (CI) 1.5-21.3], smoking (OR 4.7, CI 1.3-16.9), and body mass
index > or = 27 (OR 3.9, CI 1.2-13.0) predicted GERD. Sex, race, diabetes, PD,
non steroidal anti-inflammatory drugs (NSAIDs), calcium channel blockers, and
coffee and alcohol use did not. GERD is more common in PD patients than in HD
patients or in the general population. It is not clear whether PD per se is a
risk factor for GERD.
PMID- 10682076
TI - Response to triple treatment with omeprazole, amoxicillin, and clarithromycin for
Helicobacter pylori infections in continuous ambulatory peritoneal dialysis
patients.
AB - In this study, the response to triple treatment with omeprazole, amoxicillin, and
clarithromycin was investigated in continuous ambulatory peritoneal dialysis
(CAPD) patients with Helicobacter pylori (Hp) infections. The study enrolled 20
CAPD patients (11 male, 9 female) who had dyspeptic complaints. The mean age of
the patients was 46 (range: 21-65). The study also enrolled, as a control group,
124 patients (66 male, 58 female) who had no systemic disease, but who had upper
gastrointestinal endoscopy for dyspeptic complaints. The mean age of the patients
in the control group was 47 years (range: 20-74 years). Upper gastrointestinal
endoscopy, rapid urease test (CLO test), and direct histologic examination were
carried out to detect Hp infection. Hp infection was detected in 10 cases (50%)
in the CAPD group and in 53 cases (43%) in the control group. In both groups,
patients with Hp infection received the triple treatment of omeprazole 20 mg
twice daily for 30 days, amoxicillin 500 mg thrice daily for 15 days, and
clarithromycin 500 mg thrice daily for 15 days. To assess response to treatment,
upper gastrointestinal endoscopy, CLO test, and direct histologic examination
were repeated 3 months after initiation of the treatment. Hp was eradicated in
all of the 11 CAPD patients (100%), and in 42 of the control patients (92%). Our
results suggest that the triple treatment with omeprazole, amoxicillin, and
clarithromycin for Hp infection is as effective in CAPD patients as in the normal
population.
PMID- 10682077
TI - Tumor necrosis factor alpha as a uremic toxin: correlation with neuropathy, left
ventricular hypertrophy, anemia, and hypertriglyceridemia in peritoneal dialysis
patients.
AB - Tumor necrosis factor alpha (TNF alpha) is usually excreted by the kidney. In
dialysis patients, it accumulates. TNF alpha has been implicated in the
pathogenesis of malnutrition, diabetic neuropathy, and erythropoietin resistance.
We studied TNF alpha plasma levels in 49 stable peritoneal dialysis (PD)
patients, with the aim of correlating those levels with the presence and severity
of peripheral neuropathy, hypertrophic cardiomyopathy, and anemia. Kt/Vurea'
residual renal creatinine clearance (CrC), nutritional markers, and general
biochemistry were also determined. The average plasma level of TNF alpha was 67
+/- 32 pg/mL (range: 18.1-156.3 pg/mL; normal value 3-20 pg/mL). No correlation
was observed between TNF alpha and KT/Vurea' but a negative correlation with CrC
was seen (r: -0.37, p < 0.05). TNF alpha levels were higher in patients with
neuropathy as compared to patients with normal results (72.5 +/- 32 pg/mL vs 44
+/- 22 pg/mL, p < 0.05). Patients with neuropathy also showed a lower CrC value
(1.5 +/- 1.7 mL/min vs 3.9 +/- 2.6 mL/min, p < 0.01). TNF alpha levels were
higher in patients with left ventricular hypertrophy (LVH) with respect to normal
individuals (70.4 +/- 32 pg/mL vs 38.5 +/- 20.8 pg/mL, p < 0.05). Patients with
severe LVH showed the lowest CrC value. A direct, significant relationship was
found between TNF alpha levels and weekly erythropoietin dose (r: 0.41, p <
0.05). Patients with hypertriglyceridemia or taking lipid-lowering agents showed
a positive linear correlation between TNF alpha and triglycerides (r = 0.7, n =
14, p < 0.05). These data suggest that accumulation of TNF alpha may contribute
to the development or maintenance of some neurologic, hematologic, and cardiac
complications of uremic syndrome. Loss of residual renal function conditions an
increment in TNF alpha levels. These data continue to add support to the idea
that TNF alpha may be considered a uremic toxin.
PMID- 10682078
TI - Predictors of survival in continuous ambulatory peritoneal dialysis patients: the
importance of left ventricular hypertrophy and diabetic nephropathy.
AB - We retrospectively evaluated the factors that are prognostic in long-term
continuous ambulatory peritoneal dialysis (CAPD). From 1986 to 1997, 91 CAPD
patients (59 male, 32 female, mean age 48 years) entered the study. Their primary
renal diseases were chronic glomerulonephritis (CGN, n = 80), diabetic
nephropathy (DN, n = 10), and polycystic kidney disease (PKD, n = 1). The roles
of primary renal disease, hypertension, left ventricular hypertrophy (LVH), left
ventricular ejection fraction (LVEF), cardiac sympathetic activity, anemia,
hypoalbuminemia, and plasma concentration of parathyroid hormone (PTH) on patient
prognosis were analyzed. Among the 91 CAPD patients, 26 died during the
observation period. Of these deaths, 17 resulted from cardiovascular diseases
including cerebrovascular events (n = 7), myocardial infarction (n = 2), sudden
death (n = 7), and aortic aneurysmal rupture (n = 1). Nine patients died of non
cardiovascular events. Sclerosing encapsulating peritonitis and others, mainly
cachexia, accounted for 2 and 7 of these deaths, respectively. The 5-year
survival rate was 74%; the 10-year rate was 49%. The cumulative 5- and 10-year
success rates of CAPD were 69% and 39%, respectively. DN, hypertension, severe
LVH (more than 200 g/m2), and hypoalbuminemia were contributors to poor
prognosis. Among these, DN and severe LVH were the two main predictors by Cox
proportional hazards model. We conclude that CAPD patients with DN or severe LVH,
or both, have a greater chance of drop-out from cardiovascular events.
PMID- 10682079
TI - Peritoneal dialysis prescriptions for diabetic patients.
AB - Peritoneal dialysis offers several advantages for the treatment of diabetic
patients with renal failure. The diabetic patients is often affected by comorbid
conditions that influence the dialytic prescription and the clinical outcome.
This article reviews the pertinent pathophysiology present in the diabetic
patient with advanced renal insufficiency in an attempt to make specific
recommendations for the initiation of peritoneal dialysis and the formulation of
an adequate prescription.
PMID- 10682080
TI - Peritoneal dialysis: matching the prescription to the membrane.
AB - Peritoneal transport characteristics determine solute clearance and
ultrafiltration and influence nutrition; matching the prescription to the
membrane type is therefore important. The prognostic implications of peritoneal
transport rate are here reviewed with emphasis on high transport states. The
minimal adequate dose is discussed in the light of three important issues: (1)
the relative importance of the urea and creatinine kinetic parameters; (2) the
potential contributions of renal and peritoneal clearance to outcome; and (3) the
influence of peritoneal transport rates on minimum dose. Specific recommendations
are made for the formulation of prescriptions according to membrane type.
PMID- 10682081
TI - Nonsurgical implantation of Tenckhoff peritoneal catheters in patients on
continuous ambulatory peritoneal dialysis.
AB - From 1994 to 1998, 54 Tenckhoff peritoneal catheters were implanted in 49
patients undergoing continuous ambulatory peritoneal dialysis. The implantation
technique included bedside insertion of peritoneal catheters via trocar under
local anesthesia. Early and late complications of this technique were comparable
with surgical techniques. Cumulative survival of all catheters was 91% after one
year, 78% after two years, 71% after three years, and 68% after four years. Our
results suggest that the percutaneous technique for insertion of peritoneal
catheters remains an easy, safe, and useful technique in the management of end
stage renal disease patients.
PMID- 10682082
TI - Long-term, successful peritoneal dialysis: end-stage renal disease core
indicators study data.
AB - The proportion of U.S. dialysis patients using peritoneal dialysis (PD) continues
to fall. The reasons for the decline are presumably related to reduced patient
recruitment and poor patient retention (technique failure). Yet, the 1998
Peritoneal Dialysis Core Indicators Study (PD-CIS) report suggests that PD
provides satisfactory "long-term" renal replacement for many patients, and,
further, that this capacity is becoming more obvious and is beginning to mimic
center hemodialysis results. Several patient characteristics suggest that the key
to successful "long-term" PD involves the delivery of "adequate dialysis" and
that increasing attention to PD prescription and dialysis delivery has been
accompanied by an improvement in PD technique success.
PMID- 10682083
TI - Peritoneal dialysis immediately post transplantation.
AB - Many peritoneal dialysis (PD) patients undergo successful renal transplantation.
The outcome is similar to that for transplanted hemodialysis (HD) patients. For
delayed graft function, dialysis is necessary in the immediate post-transplant
period. PD can be undertaken, with a small risk of peritonitis and other PD
related complications. Delayed graft function is less prevalent in patients who
were on PD before transplantation than in those who were on HD. The dialysis
modality may have an impact on graft survival. The graft thrombosis rate is
unaffected by the prior mode of dialysis. Catheter-related problems are
infrequent, but there must be a low threshold for catheter removal for any sign
of non response to therapy for peritonitis or for exit-site and tunnel
infections. PD can be undertaken successfully in the immediate post-transplant
period.
PMID- 10682084
TI - Differences in assessment of patients with satisfactory or complicated continuous
ambulatory peritoneal dialysis courses.
AB - The aim of our study was a comparison of comorbid scores, peritonitis rates,
dialysis adequacy, and nutritional parameters in continuous ambulatory peritoneal
dialysis (CAPD) patients. Patients were separated into two groups: those who, in
the course of CAPD, were ingood clinical condition and underwent renal
transplantation (group I, n = 11), and those who had to discontinue CAPD
treatment (group II, n = 16) owing to death caused by comorbid disease or owing
to transfer to hemodialysis for technique failure related mainly to recurrent
peritonitis. Clinical scores were lower in group II, showing significantly more
insomnia, weakness, and anorexia. The PET D/P creatinine, mean adequacy
parameter, and urine output were similar in groups I and II. Daily protein intake
(DPI) and daily energy intake (DEI) showed higher values in group I than in group
II when expressed in g/kg and kcal/kg total body mass (TBM) respectively (DPI
1.09 +/- 0.15 g/kg TBM vs 0.92 +/- 0.31 g/kg TBM, p = 0.036; DEI 36.3 +/- 4.3
kcal/kg TBM vs 31.0 +/- 9.0 kcal/kg TBM, p = 0.048), but the intakes were not
significantly different when calculated per kilogram ideal body mass (IBM). Lean
body mass as a percent of total mass was 77.7% +/- 7.8% versus 73.9% +/- 6.8% (p
= 0.048) in groups I and II respectively. Group I showed lower serum cholesterol
than group II (179 +/- 33 mg/dL vs 231 +/- 41 mg/dL, p = 0.001) despite higher
dietary intake of cholesterol (367 +/- 137 mg/day vs 251 +/- 97 mg/day, p =
0.016), correlating with DPI (r = +0.673, p = 0.023). Our results indicate that
under conditions of similar CAPD adequacy, patients with a satisfactory course of
CAPD therapy have higher dietary intake and are better nourished than those with
a poor outcome. The changes in nutrition seem to be related to comorbid diseases
and complications of CAPD therapy. Increased cholesterol level, associated with a
diminished DPI, is prognostic of a poor outcome for CAPD patients.
PMID- 10682085
TI - Peritoneal dialysis reduces the use of non native fistula access in dialysis
programs.
AB - Access problems remain the major difficulty associated with chronic hemodialysis.
Despite recent recommendations by the Dialysis Outcomes Quality Initiative (DOQI)
that native arteriovenous (AV) fistulae are the optimal form of vascular access,
grafts and central catheters are used by many patients. We analyzed our large
Canadian regional dialysis program, which has a high prevalence of peritoneal
dialysis, to examine the effect of dialysis modality choice on vascular access
utilization. Point prevalence data were collected from our program in October
1997, and technique and patient survival data for the period 1990-1996 were
analyzed and compared to data for the remainder of Canada from the Canadian Organ
Replacement Register. Mortality rate ratios were estimated using a Poisson
regression model to correct for comorbidity, age, and end-stage renal disease
etiology. Of 141 in-center hemodialysis patients, 91 had an AV fistula, 1 had a
polytetrafluoroethylene (PTFE) graft, and 49 were catheter-dependent. The program
also included 20 home hemodialysis patients with AV fistulae, and 156 patients on
peritoneal dialysis. No mortality risk differences between hemodialysis and
peritoneal dialysis are seen in our center, nor are they seen for each modality
in comparison with the remainder of Canada. Technique survival for peritoneal
dialysis at our center was about 80% at 2 years, significantly greater than for
Canada. For the program as a whole, 49% of patients used peritoneal dialysis 35%
a native AV fistula, and 15% a central catheter. For Canada and the U.S.A.
respectively, the comparable data were: peritoneal dialysis, 32% and 17%; native
fistula, 33% and 15%; PTFE, 19% and 41%; and central catheter 16% and 27%. These
data suggest that the use of peritoneal dialysis may allow reduced use of non
native AV fistula access without mortality penalty.
PMID- 10682086
TI - Tidal peritoneal dialysis to achieve comfort in chronic peritoneal dialysis
patients.
AB - Patients with end-stage renal disease on chronic peritoneal dialysis (CPD) can
usually tolerate continuous ambulatory peritoneal dialysis (CAPD) or continuous
cycling peritoneal dialysis (CCPD) without abdominal discomfort or pain. In some
patients, pain or discomfort occurs with complete drain of the peritoneal
dialysis solution or upon initiation of dialysis filling when the peritoneal
cavity is empty. We report on the use of tidal peritoneal dialysis (TPD) as a
modality to alleviate this pain. Of 136 patients in our CPD unit, 18 (13%) were
complaining of pain with complete drain or upon instillation of PD fluid. All
were placed on TPD after other causes for abdominal pain were excluded. Six
patients were placed on 25% TPD, and 12 patients on 50% TPD. The mean Kt/V of the
patients on TPD was 2.46 +/- 0.68. With TPD, all patients had complete relief of
abdominal discomfort. Patients who develop abdominal pain with complete drain or
fill when the abdominal cavity is empty would benefit from TPD and be able to
continue with CPD.
PMID- 10682087
TI - Hemodialysis together with peritoneal dialysis is one of the simplest ways to
maintain adequacy in continuous ambulatory peritoneal dialysis.
AB - When long-term peritoneal dialysis (PD) is performed without change in the
dialysis prescription, uremic symptoms appear owing to insufficient dialysis
dose. In such cases, an increase in dialysate volume is required, but this
increase is difficult to obtain in all patients owing to limitations in abdominal
volume, lifestyle, or body weight. A combination of PD and hemodialysis (HD) is
the simplest method of overcoming these limitations. Combination therapy--HD once
per week for 4 hours and PD 6 days per week--was performed in our patients. The
total weekly dialysis dose (urea) was calculated as follows: to convert the
dialysis dose by HD to that of continuous treatment, the equivalent renal urea
clearance (EKR) was calculated and added to the dialysis dose by PD. Combination
therapy was performed in 12 patients. The reasons for the combination therapy
included ultrafiltration (UF) loss in 2 patients, uremic symptoms in 3 patients,
poor fluid management in 5 patients, umbilical hernia in 1 patient, and
hydrothorax in 1 patient. Total Kt/V per week was increased from 1.61 +/- 0.19 to
2.05 +/- 0.25 in these patients. In the 2 patients with UF loss, weight control
became easier after the combination therapy was started, and this control was
possible with hypotonic dialysate alone. In patients with uremic symptoms, the
symptoms improved; furthermore, dermal pigmentation improved in these patients.
In summary, the dialysis dose was increased and body fluids became controllable
after inducing combination therapy, resulting in improvement uremic symptoms and
increased quality of life.
PMID- 10682088
TI - Estimation of residual glomerular filtration rate and renal Kt/Vurea from
creatinine clearance in end-stage renal disease patients. The Netherlands
Cooperative Study on the Adequacy of Dialysis.
AB - Residual glomerular filtration rate (rGFR) and renal Kt/Vurea are important
parameters in clinical practice and in cohort studies. The calculation of these
parameters requires analysis of urea in a 24-hour urine collection and in a
simultaneously obtained plasma sample. In clinical practice, urea clearance is
not always determined, but creatinine clearance usually is. The aim of the
present study was to assess how well rGFR and renal Kt/Vurea can be estimated
from creatinine clearance in end-stage renal disease (ESRD) patients. Of new
Dutch ESRD patients, 365 were consecutively included in this study at the start
of their chronic dialysis treatment. The estimation models were based on a random
sample of two-thirds of the patients; the models were validated on the remaining
one-third. We built models for pre-dialysis and peritoneal dialysis (PD) patients
together (pre + PD group), and separate models for hemodialysis (HD) patients.
Mean measured rGFR of pre + PD patients in the validation group was 6.3
mL/minute. The limits of agreement (LoAs) between estimated and measured rGFR
were within -1.5 and +1.5. Mean measured rGFR in HD patients was 3.1 mL/minute
(LoAs: -0.3 and +0.3). These relatively small limits of agreement reveal that,
should urea clearance be missing, rGFR can be estimated by a formula in which
creatinine clearance and 24-hour urine production are included. The estimation of
renal Kt/Vurea from creatinine clearance was less precise.
PMID- 10682089
TI - Trends in initiation of dialysis in an urban dialysis clinic in the United
States: a long way from dialysis outcomes quality initiative guidelines.
AB - The guidelines issued for peritoneal dialysis by the National Kidney Foundation
Dialysis Outcomes Quality Initiative (NKF-DOQI) suggest initiation of dialysis at
a glomerular filtration rate (GFR) of 10.5 mL/min/1.73 m2. We undertook this
study to determine trends at a center in Philadelphia. Using the MDRD
(Modification of Diet in Renal Disease) formula, we estimated the GFR
(mL/min/1.73 m2) at the time of first dialysis for patients starting on dialysis
at the center between 1994 and 1996. Data on 72 of the 86 new patients were
available. Of the 72, 69 patients (96%) were black and 29 (40%) were diabetic.
The estimated GFR at the time of dialysis initiation was 6.3 +/- 0.3 mL/min/1.73
m2. Only 3 patients (4%) had a GFR > 10.5; 25 patients (35%) had GFR < 5.0.
Patients with a lower GFR had more severe acidosis (HCO3 15.8 +/- 0.5 mmol/L vs
19.5 +/- 0.9 mmol/L, p = 0.0023) and greater impairment in divalent ion
metabolism (PO4: 7.6 +/- 0.2 mg/dL vs 5.6 +/- 0.3 mg/dL, p < 0.0001). Diabetic
patients were initiated on dialysis at a higher level of GFR than non diabetic
patients (7.2 +/- 0.3 mL/min/1.73 m2 vs 5.7 +/- 0.4 mL/min/1.73 m2, p = 0.0087).
Even though diabetic patients had higher GFR and lower serum creatinine (8.6 +/-
0.5 mg/dL vs 11.8 +/- 0.9 mg/dL, p = 0.0021) than non diabetic patients, blood
urea nitrogen (BUN) was similar in the two groups (89 +/- 3.7 mg/dL vs 96.8 +/-
5.8 mg/dL, p = 0.73). This difference may indicate that nondiabetic patients had
a greater decline in protein intake. Finally, a trend towards initiation of
dialysis at higher levels of renal function was seen with time (GFRs 5.5 +/- 0.4
mL/min/1.73 m2, 6.4 +/- 0.4 mL/min/1.73 m2, and 6.9 +/- 0.6 mL/min/1.73 m2 for
1994, 1995, and 1996 respectively; p = 0.058, 1994 vs 1996). The trend was
stronger for diabetic patients (GFR 6.3 +/- 0.4 mL/min/1.73 m2 and 8.1 +/- 0.7
mL/min/1.73 m2 for 1994 and 1996 respectively; p = 0.06) than for non diabetic
patients (GFR 5.1 +/- 0.5 mL/min/1.73 m2 and 6.2 +/- 0.7 mL/min/1.73 m2 for 1994
and 1996 respectively; p = 0.22). We conclude that initiation of dialysis is
delayed in urban centers, particularly in non diabetic patients, and that the
current practice is far below the DOQI recommendations.
PMID- 10682090
TI - The importance of an extra hour of cycler therapy to obtain better adequacy.
AB - As continuous ambulatory peritoneal dialysis (CAPD) patients lose residual renal
function, it frequently becomes impossible from them to obtain adequate dialysis
unless the dialysis prescription is changed. Increasing the dwell volumes,
increasing the frequency of exchanges, and using a night-exchange device or a
cycler are the means available to improve adequacy. In an effort to obtain
dialysis adequacy, we studied how an extra hour on cycler therapy can contribute
to improving dialysis adequacy. Over 18 months, we optimized solute clearance
using the PD Adequest program (Baxter Healthcare Corporation, Chicago, Illinois,
U.S.A.) in 70 patients. After finding the best total cycler volume, we compared
the weekly creatinine clearance and weekly Kt/V from 8-hour cycler therapy to
that from 9-hour cycler therapy for the four types of membrane transport. Adding
one extra hour on cycler therapy improved weekly creatinine clearance by 3-6.5 L
and the weekly Kt/V by 0.16-0.20. When patients are marginally approaching the
required weekly Kt/V or creatinine clearance, an extra hour on the cycler may
help to achieve the desired adequacy.
PMID- 10682091
TI - Bioelectrical impedance analysis in the evaluation of the nutritional status of
continuous ambulatory peritoneal dialysis patients.
AB - The authors evaluated the nutritional status of 47 continuous ambulatory
peritoneal dialysis (CAPD) patients, 26 men (age 58.9 +/- 14.6 years, duration on
CAPD 27.3 +/- 18.3 months) and 21 women (age 56.2 +/- 14.9 years, duration on
CAPD 34.5 +/- 23.4 months), using subjective global assessment (SGA), an
established method for the nutritional assessment of dialysis patients, and
bioelectrical impedance analysis (BIA: body cell mass, fat mass, and phase
angle). Of the studied patients, 19 were diabetic (age 59.7 +/- 13.8 years,
duration on CAPD 29.2 +/- 19.7 months) and 28 were non diabetic (age 53.9 +/-
14.3 years, duration on CAPD 31.5 +/- 21.8 months. According to SGA, 24 patients
were scored as well nourished (Group I), 18 as mildly malnourished (Group II),
and 5 as moderately malnourished (Group III). No patient scored as severely
malnourished (Group IV). Analysis of the main nutritional parameters for the
subgroups revealed a proportional decrease in phase angle, with a statistically
significant correlation (p < 0.009) between phase angle and SGA. No significant
difference was seen in serum albumin levels between patients in Group I and Group
II, but the mean level was significantly lower in patients in Group III compared
to Group I. The nutritional and biochemical data in diabetic patients and non
diabetic patients were not significantly different. BIA phase angle seems to be a
simple and reliable method for the routine assessment of nutritional status in
CAPD patients.
PMID- 10682092
TI - Incidence of gingival hyperplasia caused by calcium antagonists in continuous
ambulatory peritoneal dialysis patients.
AB - Calcium antagonists are widely used for the treatment of cardiovascular diseases
in patients receiving dialysis therapy. The incidence of gingival hyperplasia has
been reported as 10%-20% in patients treated with calcium antagonists in the
general population. However, precise reports examining the incidence or
pathogenesis of gingival hyperplasia in continuous ambulatory peritoneal dialysis
(CAPD) patients are lacking. We recruited 54 CAPD patients. Three patients
treated with long-acting nifedipine and one patient treated with felodipine were
reported by a periodontist to have gingival hyperplasia. No patients were taking
amlodipine and other calcium antagonists. After discontinuation of calcium
antagonists, gingival hyperplasia disappeared within 1 month. Based on these
results, we suggest that it is important to examine whether the gingiva is
overgrown in CAPD patients taking calcium antagonists.
PMID- 10682093
TI - Evidence that gender difference affects peritoneal dialysis capacity in
continuous ambulatory peritoneal dialysis patients.
AB - The progression of renal disease is reported to be more rapid in male patients
than in premenopausal females. However, few studies compare the difference in
dialysis therapy between males and females. We compared the efficacy of
peritoneal dialysis capacity, using measurements of retention volume and pelvic
cavity by helical section of computed tomography (CT) in 6 male and 6 female
patients. The patients did not differ significantly in age (males: 54 +/- 3
years; female: 56 +/- 4 years). Males were heavier than females (p < 0.05).
Retention volume in the visceral cavity was significantly larger in males (1787
+/- 43 mL) than in females (1580 +/- 59 mL) (p < 0.05). Peritoneal dialysis
capacity was evaluated by peritoneal equilibration test (PET). Although no
significant differences were observed in the PET data, when the PET results at 4
hours were divided by body weight in kilograms, a significant difference between
males and females was seen (p < 0.05). There was a mild, but not significant,
correlation between the volume of the pelvis as measured by helical CT and the
PET data per kilogram body weight (p = 0.07). These results suggest that gender
differences in peritoneal dialysis capacity relate partially to the difference in
pelvic cavity volume.
PMID- 10682094
TI - The use of peritoneal dialysis in special situations.
AB - This brief review outlines several situations in which peritoneal dialysis (PD)
can be used to address clinical situations that are out of the ordinary for end
stage renal disease (ESRD). For example, PD methodology can be used not only to
treat ESRD patients with difficult psychosocial problems that obviate other
dialysis options, but also to control ascites accumulation in patients with liver
failure, to treat congestive heart failure in azotemic patients with progressive
cardiomyopathy, to administer systemic medication via the peritoneal cavity, and
to provide additional clearance in demanding circumstances. In discussing these
unusual applications for PD, we open the door to extending the indications for PD
to a broader spectrum of clinical problems.
PMID- 10682095
TI - Residual volume in continuous ambulatory peritoneal dialysis patients from
various solute calculations.
AB - Residual volume (RV) has been measured using various methods and various solutes.
This prospective study set out to determine residual volume by using various
solute calculations, and to estimate mean residual volume in stable Thai CAPD
patients. Complete data from 9 patients (6 males, 3 females) were analyzed.
Residual volume was calculated using various solutes including sodium (Na),
potassium (P), glucose (G), urea (U), and creatinine (C). The calculation using
sodium was too variable to use to calculate a mean. Mean of residual volume was
calculated from the other solutes as RV1 (mean of PUC), RV2 (mean of GUC), and
RV3 (mean of PGUC). Mean residual volumes did not correlate with sex, body
weight, body surface area, hematocrit, albumin, or membrane characteristics
(drained volume). Comparing all means calculated in our study, creatinine was the
solute that yielded the most accurate mean, with a correlation coefficient of
0.877, 0.965, and 0.956 for RV1, RV2, and RV3 respectively. In this study, mean
residual volumes were 212.49 +/- 100.03 mL, 255.23 +/- 142.58 mL, and 250.42 +/-
121.60 mL for RV1, RV2, and RV3 respectively.
PMID- 10682096
TI - Failure of icodextrin to provide adequate ultrafiltration in continuous
ambulatory peritoneal dialysis patients.
AB - Icodextrin, a starch-derived glucose polymer with an average molecular weight of
20,000 D, has been developed partly as a response to some of the disadvantages of
dextrose. It has been suggested that icodextrin solutions are able to provide
sustained ultrafiltration (UF) over long dwell times of 8-12 hours in continuous
ambulatory peritoneal dialysis (CAPD). In this paper we describe three patients
on CAPD: 2 males and 1 female aged 60, 67, and 58 years respectively, duration on
CAPD 47, 60, and 15 months respectively. All of these patients, who were
categorized as high transporters according to peritoneal equilibration test (PET)
results, presented early signs of ultrafiltration loss with no evidence of
peritoneal inflammation. Icodextrin solution was used in a single nightly
exchange with 10-12 hours' dwell, for a period of 5-30 days. In all of these
cases, icodextrin solution failed to provide adequate ultrafiltration and the
patients returned to the previously used regime of five daily hypertonic
exchanges of 3.86% glucose concentration. Although these negative results were
not clearly explained, we report these three cases because they exemplify some
limitations of icodextrin solution to provide adequate ultrafiltration, at least
in a small number of CAPD patients.
PMID- 10682097
TI - Incremental initiation of peritoneal dialysis: current practice.
AB - The Dialysis Outcomes Quality Initiative (DOQI) guidelines define initiation of
peritoneal dialysis (PD) as "timely" when dialysis is started using deteriorating
renal function and nutritional indices as criteria--before the appearance of
frank uremia--and as "incremental" when the initial dose of PD is small, bringing
total clearances to or above target values, with the understanding that the dose
of PD will be increased as renal function is lost. Current practice regarding
timely/incremental PD initiation was studied by analyzing the responses to a
questionnaire distributed to 250 U.S. and Canadian nephrologists. A total of 89
responses were received. Only 30 responders (33.7%) practice incremental PD
initiation. The more frequent reasons for not practicing incremental PD
initiation included anticipated patient noncompliance, the desire to obtain the
highest possible clearances, disagreement with the DOQI rationale, and late
referral of patients to the nephrologists. Renal clearances were used by 58
responders (65.2%) as independent criteria to start dialysis. Creatinine
clearance, at a cut-off level of 9.9 +/- 2.1 mL/minute, was the criterion most
frequently used to start PD. Nutritional indices were used by 66 responders
(74.2%) as criteria to start PD. Frequently used nutritional indices were serum
albumin, body weight, normalized equivalent of protein nitrogen appearance
(nPNA), and dietary assessment. The survey provides clues about research studies
and educational activities that will be needed in the future.
PMID- 10682098
TI - Small-solute clearances in diabetic subjects on continuous ambulatory peritoneal
dialysis: comparison to nondiabetic subjects.
AB - Normalized clearances for urea and creatinine were compared between 121 diabetic
subjects (256 clearances) and 181 nondiabetic subjects (357 clearances) on
continuous ambulatory peritoneal dialysis (CAPD) with four 2-L exchanges daily.
Urea clearance was normalized by VWatson (Kt/Vur), while creatinine clearance was
normalized by both VWatson (Kt/Vcr) and body surface area (Ccr). Height, weight,
body water (V), and body surface area did not differ between the diabetic and the
nondiabetic groups. Also, renal Kt/Vur, renal Kt/Vcr, renal Ccr, and peritoneal
Kt/Vur did not differ between the groups. Weekly peritoneal Kt/Vcr (diabetic
group 1.36 +/- 0.38, nondiabetic group 1.31 +/- 0.31, p = 0.048) and weekly
peritoneal Ccr (diabetic group 47.6 +/- 11.0 L/1.73 m2, nondiabetic group 45.4 +/
9.2 L/1.73 m2, p = 0.012) were both higher in diabetic subjects. The percentage
of high/high-average transporters was higher in the diabetic group (64.9% vs
48.6% in nondiabetic group, p = 0.006). The following total (peritoneal + renal)
weekly clearances were obtained: Kt/Vur, diabetic group 2.07 +/- 0.63,
nondiabetic group 2.02 +/- 0.56, NS; Kt/Vcr, diabetic group 2.06 +/- 0.78,
nondiabetic group 1.92 +/- 0.74, p = 0.026; Ccr, diabetic group 72.7 +/- 28.5
L/1.73 m2, nondiabetic group 67.2 +/- 26.4 L/1.73 m2, p = 0.013. Normalized total
creatinine clearances are higher in diabetic subjects than nondiabetic subjects
on the same CAPD schedule and with the same renal clearances of urea and
creatinine and the same total Kt/Vur, because peritoneal creatinine clearances
are higher in the diabetic subjects. This finding is caused by higher peritoneal
transport in the diabetic subjects and is not an artifact caused by the
normalization process.
PMID- 10682099
TI - Peritoneal sclerosis--an overview.
AB - The term peritoneal sclerosis encompasses a vast range of peritoneal alterations,
from the low clinical impact manifestations associated with chronic peritoneal
dialysis, to dramatic thickening of the peritoneal membrane, which is rare, but
often life-threatening. The frequency, pathology, etiopathogenesis, clinical
manifestations, diagnostic criteria, therapy, and prevention of peritoneal
sclerosis are reviewed. Preliminary observations from the Italian Registry of
Peritoneal Sclerosis, established in the framework of a program of the Italian
Society of Nephrology, are reported.
PMID- 10682100
TI - Comparing peritonitis in continuous ambulatory peritoneal dialysis patients
versus automated peritoneal dialysis patients.
AB - The purpose of our study was to compare the incidence of peritonitis between
continuous ambulatory peritoneal dialysis (CAPD) treatment (Group I) and
automated peritoneal dialysis (APD) treatment (Group II) taking into account the
same population. We compared 20 patients with a follow-up of 215 patient-months
on CAPD and 252 patient-months on APD. Demographic data, diagnosis, peritoneal
equilibration test (PET) results, adequacy, and peritonitis rate were analyzed.
Diagnoses included glomerulopathy 35%, autosomal dominant polycystic kidney
disease (ADPKD) 20%, Type II diabetes 10%, systemic lupus erythematosus 5%,
interstitial nephritis 5%, nephrolitiasis 5%, and unknown 20%. PET results showed
that the group consisted of 30% high transporters, 45% high-average transporters,
and 25% low-average transporters. Kt/V for Group I was 1.3 +/- 0.3, and for Group
II, 1.83 +/- 0.48. Creatinine clearance for Group I was 43.64 +/- 7.31
L/week/1.73 m2, and for Group II, 52.42 +/- 13.47 L/week/1.73 m2. Group I
presented a peritonitis rate of 8.3 episodes/patient-month, and Group II
presented a rate of 18.9 episodes/patient-month. Gram-positive organisms were
responsible for 49.8% of episodes of peritonitis in Group I (S. aureus 26.6%, S.
epidermidis 16.6%, others 10%) and 83% of peritonitis episodes in Group II (S.
epidermidis 46.6%, S. aureus 20%). Gram-negative organisms were responsible for
16.5% of episodes of peritonitis in Group I. No gram-negative peritonitis was
seen in Group II. APD patients developed two cases of candida peritonitis. Our
preliminary results show that Group II exhibited a decrease in peritonitis rate
while achieving better adequacy. In CAPD and APD peritonitis, gram-positive
organisms predominated. In APD, we observed an increase in S. epidermidis
incidence. No gram-negative organisms were observed in APD. It seems that APD is
a safer treatment owing to the lower peritonitis incidence.
PMID- 10682101
TI - Peritoneal dialysis--associated peritonitis caused by gram-negative bacteria:
characteristics similar to spontaneous bacterial peritonitis?
AB - The aim of the study was to investigate the characteristics of PD-related
peritonitis caused by gram-negative bacteria (GNP). We retrospectively studied
the medical records of 164 patients (114 males, 50 females; mean age 46 +/- 15
years) who continued PD beyond 5 months between 1984 and 1998. The average
observation time was 40 +/- 28 months (total of 6609 patient-months). A total of
166 episodes of peritonitis occurred during that time (mean incidence: 1
episode/40 patient-months). Of these, 35 were GNPs, and GNP incidence stayed
almost constant over time. Most GNP patients (63%) recovered without complication
with an average of 14 days' antibiotic treatment. In only 4 cases was PD
abandoned. Clinical features of GNP were similar to those of spontaneous
bacterial peritonitis (SBP). The unchanged incidence of GNP over time with
advanced connection devices suggests that there are important mechanisms
promoting micro-organisms of endogenous origin into the peritoneal cavity in PD
patients.
PMID- 10682102
TI - Exit-site and catheter care: review of important issues.
AB - This brief review addresses the impact that several important aspects of catheter
technology and exit-site care have on catheter-related infections and catheter
longevity. The discussion includes exit-site microbiology, catheter
configuration, exit-site care, and catheter salvage, following which a summary of
recommendations is presented.
PMID- 10682103
TI - Simultaneous catheter removal and replacement in peritoneal dialysis infections:
update and current recommendations.
AB - Problematic peritoneal dialysis infection is a major cause of catheter loss and
interruption of peritoneal dialysis (PD) therapy. In selected instances,
problematic infection can be successfully treated by removing and replacing the
catheter while continuing with PD. Accumulated experience has helped to define
the circumstances under which a removal/replacement procedure is likely to be
safe and under which complications are likely to arise. It appears that
simultaneous removal and replacement can be expected to succeed when problematic
infection is associated with tunnel infection, with recurring peritonitis
repetitively culturing the same organism but clearing between episodes, and with
gram-positive organisms. Success is less likely in the presence of ongoing
inflammation, of active infection, of gram-negative or fungal organisms, or of
any evidence of intra-abdominal adhesions. We review the literature on which
these criteria are based and conclude with updated recommendations.
PMID- 10682104
TI - Outcome of Pseudomonas aeruginosa exit-site and tunnel infections: a single
center's experience.
AB - We reviewed the course and outcome of all Pseudomonas aeruginosa (PA) exit-site
and tunnel infections (ESI/TI) that occurred at our home peritoneal dialysis (PD)
unit over a 3-year period (July 1995 to June 1998). We documented PA ESI/TI in 19
out of a total of 467 patients. Of the 19 patients, 12 having local redness and
tenderness but no discharge were treated conservatively with increased frequency
of dressing with or without hydrogen peroxide locally. Of the 12 cases receiving
local care, 7 resolved without recurrence over 14.4 months follow-up, while the
remaining 5 developed persistent ESI/TI with discharge and required treatment
with antibiotics. Seven more patients who initially presented with purulent
discharge also received systemic antibiotics. Only 1 of the 12 patients with PA
ESI/TI treated with antibiotics resolved; the remaining 11 patients developed PA
peritonitis over a 1-month to 7-month period after the initial PA ESI/TI. In 2 of
these 11 patients, simultaneous PD catheter removal and replacement was attempted
for the treatment of PA ESI/TI, but these patients also developed PA peritonitis
1-3 weeks after the procedure. Of the 11 patients with PA peritonitis associated
with PA ESI/TI, 1 died, 6 were transferred to permanent hemodialysis, and just 4
continued PD after PD catheter replacement. Though not frequent, PA ESI/TI is
still a serious complication of home PD at our unit, resulting in ESI/TI-related
PA peritonitis and catheter loss in 58% of cases. Local treatment of mild PA
ESI/TI (redness and induration) seems to be effective. On the other hand,
patients with purulent discharge are likely to develop peritonitis and technique
failure despite antibiotic therapy. Early catheter replacement can be considered
in these cases.
PMID- 10682105
TI - Once-daily intraperitoneal cefazolin and oral ciprofloxacin as empiric therapy
for the treatment of peritonitis.
AB - The Ad Hoc Advisory Committee on Peritonitis Management has recommended
intraperitoneal (i.p.) cefazolin and an aminoglycoside as empiric therapy for the
treatment of peritonitis. Because most of our patients are on continuous cycler
therapy, we developed a strategy of once-daily i.p. cefazolin and oral
ciprofloxacin as empiric therapy. All patients in our unit that developed
peritonitis were given a once-daily 2 g load of i.p. cefazolin, plus 500 mg
ciprofloxacin orally, twice daily. Ciprofloxacin was given two hours after any
phosphate binder or iron supplement. The i.p. cefazolin was allowed to dwell for
at least six hours. The dialysate was then drained and chronic peritoneal
dialysis (CPD) resumed. Organisms sensitive to cefazolin were treated for 14 days
with once-daily cefazolin alone; resistant organisms were treated with
alternative antibiotics. A total of 40 patients were treated with this empiric
regimen. Of these, 35 (88%) successfully continued CPD therapy, 1 (2%)
transferred to hemodialysis, and 4 (10%) expired two weeks after the onset of
peritonitis. A total of 22 patients (55%) were treated successfully with once
daily i.p. cefazolin. Although once-daily i.p. cefazolin and oral ciprofloxacin
permitted continuation of CPD therapy in most patients in this study, the therapy
was not optimal. While vancomycin may have provided better coverage, recent
reports of vancomycin-resistant enterococci and Staphylococcus aureus present a
major concern.
PMID- 10682106
TI - Peritoneal toxicities of hypertonic dextrose dialysate.
AB - This report reviews the peritoneal toxicities of hypertonic (4.25%) dextrose
dialysate. In vitro incubation of peritoneal cell lines (polymorphonuclear cells,
macrophages) in hypertonic dextrose solutions have demonstrated direct
cytotoxicity, decreased phagocytosis and bacterial killing, and decreased
production of superoxide and inflammatory cytokines and leukotrienes. Hypertonic
dextrose dialysate also inhibits the proliferation of mesothelial cells and
causes increased mesothelial production of transforming growth factor,
potentially leading to peritoneal fibrosis. In vivo animal studies have also
shown peritoneal toxicity of hypertonic dextrose dialysate. Recently, the use of
peritoneal dialysate with high glucose concentration has been found to lead to
the deposition of advanced glycosylation end-products in the peritoneal
structures and to the development of high peritoneal solute transport. Fluid
control in peritoneal dialysis should not be based on the liberal use of
hypertonic dextrose dialysate. Instead, it should be achieved by restriction of
salt and water intake and prescription of the peritoneal dialysis schedule
(particularly the dwell time) based on peritoneal equilibration test (PET)
findings. Newer osmotic agents may obviate the use of hypertonic dialysate in the
future.
PMID- 10682107
TI - Reliability of the 7-point subjective global assessment scale in assessing
nutritional status of dialysis patients.
AB - Subjective global assessment (SGA) is a method to score nutritional status in a
standardized way. The original 3-point scale has been replaced by a 7-point
scale. The reliability of the latter scale has never been tested. We therefore
assessed inter-observer and intra-observer reliability. Furthermore, we examined
the relationship of SGA with other objective nutritional parameters. In 13
hemodialysis and 9 peritoneal dialysis patients, two nurses assessed SGA. They re
examined the same patients two weeks later. Anthropometric measurements and blood
samples were taken at the first assessment. According to SGA, 2 patients (9%)
were classified as severely malnourished, 6 (27%) as mildly malnourished, and 14
(64%) as well nourished. The 7-point SGA scale showed fair inter-observer
reliability [intraclass correlation (ICC) = 0.72] and good intra-observer
reliability (ICC = 0.88). A strong correlation was present between the 7-point
SGA scale and body mass index (BMI) (r = 0.79, p < 0.001), % fat (r = 0.77, p <
0.001), and mid arm circumference (r = 0.71, p < 0.001). Lower correlations were
found with mid arm muscle circumference and serum albumin. With respect to
biochemical markers, the strongest relationship was found with prealbumin (r =
0.60, p = 0.004). We conclude that the 7-point SGA scale is a valid and reliable
tool to assess nutritional status among end-stage renal disease patients. We
suggest that one observer or a select group of observers perform the assessments
to gain maximum benefit from the reliability of the SGA instrument.
PMID- 10682108
TI - Phthalic acid is the main metabolite of the plasticizer di(2-ethylhexyl)
phthalate in peritoneal dialysis patients.
AB - Di(2-ethylhexyl) phthalate (DEHP) is the most commonly used plasticizer in
polyvinyl chloride (PVC) plastics, and is therefore a major constituent of
continuous ambulatory peritoneal dialysis (CAPD) bags. Because DEHP is not
chemically bound, it leaches out of the plastic matrix. Recently, we found that
leukocyte function in vitro is impaired by a mixture of metabolites of DEHP. In
the present study, we investigated the metabolism of DEHP in patients on CAPD.
The study group consisted of 10 stable patients, on CAPD for at least 6 months,
using a plasticizer-containing PVC PD system [ANDY Plus (Fresenius Medical Care,
Bad Homburg, Germany)]. Effluent dialysate and urine samples were collected over
24 hours, and a 10 mL blood sample was drawn. Concentrations of DEHP and its
metabolites mono(2-ethylhexyl) phthalate (MEHP), phthalic acid (PA), and 2
ethylhexanol (2-EH) were determined in urine, dialysate, and serum using gas
chromatography/mass spectrometry. Additionally, the degree of glucuronidation of
the phthalic acid esters in urine were determined. In serum, dialysate, and
urine, PA was the predominant metabolite of DEHP (0.205 +/- 0.067 mg/L, 0.284 +/-
0.180 mg/L, and 1.34 +/- 1.00 mg/L, respectively), but concentrations of MEHP
were low (0.0100 +/- 0.0056 mg/L, 0.022 +/- 0.008 mg/L, 0.011 +/- 0.0064 mg/L,
respectively). Urinary MEHP was glucuronidated to approximately 15%. PA was 35%
eliminated as a glucuronide. Unlike healthy subjects, PD patients do not
eliminate DEHP mainly in the form of MEHP or MEHP metabolites. They further break
these compounds down to PA. The fact that concentrations of PA in urine exceed by
far the respective serum concentrations indicates that PA is secreted by the
kidney. Further research on the toxicological aspects of plasticizers in uremic
patients should take these findings into account.
PMID- 10682109
TI - Lack of interference of icodextrin on creatinine measurements.
AB - Glucose has been reported to interfere in the analysis of creatinine by the Jaffe
method. The potential interference of icodextrin and its primary metabolites
(maltose, maltotriose, maltotetraose) on creatinine measurements has not
previously been addressed. We evaluated the potential interference of icodextrin
and its metabolites at various concentrations using both the Jaffe and Creatinine
Plus methods. Interference was determined in samples containing 0.6-20 mg/dL
creatinine in saline solution or in plasma (n = 6), and in dialysate samples (n =
6) spiked with icodextrin, maltose, maltotriose, and maltotetraose at
concentrations up to twofold the level found in plasma and dialysate from
patients treated using icodextrin. Results confirm that no interference occurs
when using either the colorimetric Jaffe method or the enzymatic Creatinine Plus
method at levels up to 65 g/L icodextrin, 2 g/L maltose, 2 g/L maltotriose, and 1
g/L maltotetraose, levels representing worst-case clinical concentrations. In
addition, our results confirm that comparable values can be obtained using either
the Jaffe or the Creatinine Plus method for the analysis of creatinine in uremic
plasma and in dialysate samples.
PMID- 10682110
TI - Low concentrations of glucose degradation products in peritoneal dialysis fluids
and their impact on biocompatibility parameters: prospective cross-over study
with a three-compartment bag.
AB - The side effects of glucose degradation products (GDPs) in conventional
peritoneal dialysis (PD) fluids are well described. Using the three-compartment
bag concept--that is, in situ preparation of concentrated glucose solution into a
standard ionic solution--a GDP-free solution can be processed. To investigate the
possible impact of this product on biological and clinical parameters, we carried
out a prospective cross-over study with 31 patients, comparing the short-term
effects of conventional PD and GDP-free PD solutions. Classical peritoneal
parameters and ultrafiltration rate did not change during the study. After three
months and after six months with the three-compartment bag, cancer antigen 125
(CA125) concentration in overnight fluid increased significantly (p < 0.001) from
24.4 IU/mL to 44.4 IU/mL and 41.1 IU/mL respectively. CA125 decreased
significantly (p < 0.01) to 21.7 IU/mL after three months with the conventional
solution. No change in hyaluronan concentration was observed. A slight increase
of procollagen III N-terminal peptide in overnight effluent with the GDP-free
solution was followed by a significant reduction after three months with standard
solution. In summary, our data show that the GDP-free PD fluid improves
mesothelial cell mass and turnover even after a short-term period of three
months. A better quality of PD solution is obtained by using the three
compartment bag.
PMID- 10682111
TI - Influence of apolipoprotein E genotype on lipid and lipoprotein levels in
continuous ambulatory peritoneal dialysis patients.
AB - Apolipoprotein (Apo) E has an important role in triglyceride (TG)-rich
lipoprotein metabolism, and the genotype of Apo E is associated with premature
coronary artery disease. Patients undergoing continuous ambulatory peritoneal
dialysis (CAPD) develop various abnormalities of lipid metabolism and are prone
to develop accelerated atherosclerosis. To investigate the distribution of Apo E
genotype, and to evaluate the influence of Apo E polymorphism on lipid metabolism
in CAPD patients, we measured Apo E genotypes, serum lipid, and lipoprotein
levels in 54 CAPD patients (M:F = 1:1). The most common genotype of Apo E in the
CAPD patients was E 3/3, found in 68.5%. The frequencies of the other genotypes
were E 2/3, found in 14.8%, and E 4/3, found in 16.7%. No genotypic differences
in Apo E were seen in the patients with regard to the presence of diabetes, the
level of parathyroid hormone, or the transport characteristics of the peritoneal
membrane. When comparing lipid levels by Apo E genotype, the total cholesterol
and TG levels of E 2/3 patients were significantly higher than those of E 3/3 or
E 4/3 patients. The differences in high-density or low-density lipoprotein
cholesterol levels by Apo E genotype were not significant. In comparing
lipoprotein levels by Apo E genotype, the Apo B and lipoprotein (a) levels of E
2/3 patients were significantly lower than those of E 3/3 or E 4/3 patients. In
conclusion, the Apo E 3/3 genotype seems to be the most common genotype in CAPD
patients, and the Apo E 2/3 genotype appears to be associated with high
cholesterol and TG levels. These results demonstrate the need for further
prospective studies in these subjects aimed at elucidating the impact of genetic
variation at the Apo E locus on the development of atherosclerosis.
PMID- 10682112
TI - Do dialysis patients need extra folate supplementation?
AB - To assess folate status and to evaluate the need for conventional folate
supplementation in patients on dialysis, we measured serum folate, vitamin B12,
and red cell folate concentrations by radioimmunoassay. Thirty-four continuous
ambulatory peritoneal dialysis (CAPD) patients and 60 hemodialysis (HD) patients
who had not been supplemented with folate were enrolled. Serum folate levels (5.8
+/- 3.6 ng/mL vs 2.0 +/- 1.1 ng/mL, p < 0.001) and vitamin B12 levels (831.4 +/-
416.9 pg/mL vs 513.9 +/- 213.3 pg/mL, p < 0.001) were significantly higher in
CAPD patients than HD patients. The red cell folate levels (849.7 +/- 489.4 ng/mL
vs 491.0 +/- 253.2 ng/mL, p < 0.001) were also significantly higher in CAPD
patients. The incidences of folate deficiency in CAPD and HD patients were
overestimated using the cut-off value for serum folate concentration (3.0% vs
71.7%, respectively), but the incidence of true folate deficiency was lower using
the cut-off value for red cell folate level (0.0% vs 10.0%, respectively). In
conclusion, the true incidence of folate deficiency in stable CAPD and HD
patients is surprisingly low, even in patients who may not be taking folate
supplements. The need for conventional folate supplementation in patients with
end-stage renal disease on dialysis must therefore be re-evaluated. Before the
decision is made to use folate supplementation, measurement of red cell folate is
essential to assess of folate reserves of the patients on dialysis.
PMID- 10682113
TI - Peritoneal mesothelial cells produce complement factors and express CD59 that
inhibits C5b-9-mediated cell lysis.
AB - The CD59 membrane protein confers protection from C5b-9-mediated cell lysis.
Because evidence exists for complement (C) activation and generation of C5b-9 in
the peritoneal cavity during chronic peritoneal dialysis (CPD), we investigated,
on mesothelial cell (MC) lines, the expression of CD59 and the production of C
components. Four MC lines were obtained from children on CPD, and two from non
uremic children. CD59 expression on MCs was investigated with anti-CD59
monoclonal antibody (mAb) and polyclonal goat immunoglobulin G (IgG). MC lines
were positive for staining with anti-CD59 mAb. Western blotting analysis of MC
membrane demonstrated a band with the same molecular weight as CD59. Incubation
of MC with anti-CD59 mAb abrogated the protective effect of CD59 (100%
cytotoxicity). C3, C4, and C6 were detected in the supernatants of MC; in non
uremic MC supernatants, C5, C7, C8, and C9 were also detectable, and C4
concentration was tenfold higher. CD59 expression confers to MCs protection from
C5b-9-mediated lysis. MCs produce C factors. These findings suggest that
production of complement components and expression of CD59 on MCs could play a
role both in peritoneal cavity infection (decreased complement production) and in
peritoneal membrane damage (decreased CD59 expression and reduced
remesothelialization owing to MC lysis).
PMID- 10682114
TI - Five years' experience of a hospital-based home-care renal nursing service.
AB - A pediatric home-care renal nursing service was initiated in our unit five years
ago to provide direct respite care in the home for families on the dialysis and
transplant program. This nursing post responded to parental requests for more
practical support in the home. A trained children's nurse with renal and
community nursing qualifications was recruited with charitable support. Between
October 1993 and October 1998, 286 respite-care visits were performed. Of the
visits, 57% were for children on continuous cycling peritoneal dialysis (CCPD),
20% were for pre-dialysis support (mainly supplementary feeding of children < 5
years old), 15% were for children on hemodialysis, and 8% were for children in
the post transplantation period. The age of children receiving respite care
ranged from 2 months to 15 years. Distances traveled from the unit to the home
ranged from 5-150 miles with visit times of 2-10 hours. Of all visits, 60% were
performed during the day, and 60% involved sibling care. The parental response to
home-care support resulted in the incorporation of the home-care nurse into the
unit's nursing budget. The new nursing post has raised issues of the professional
accountability of home-care nurses, of patient confidentiality, and of
communication with multi-disciplinary team members. Reflecting upon our five-year
experience of home-care nursing has encouraged us to further develop our home
support program for families living at increasing distances from our unit.
PMID- 10682115
TI - Evidence of central hypothyroidism in children on continuous ambulatory
peritoneal dialysis.
AB - This study investigated the effects of chronic peritoneal dialysis on thyroid
function and thyroid volume of patients with chronic renal failure (CRF). We
measured the levels of serum and dialysate thyroid hormones [total thyroxine
(TT4), total triiodothyronine (TT3), free thyroxine (fT4), and free
triiodothyronine (fT3)], thyrotropin (TSH), thyroglobulin (Tg), and thyroid
volume in 10 children on chronic peritoneal dialysis [9 continuous ambulatory
peritoneal dialysis (CAPD), 1 continuous cycling peritoneal dialysis (CCPD)] at
baseline and after one year. Serum levels in patients were compared with those in
age- and sex-matched healthy children and were scored as normal, low, or high. At
the beginning of study, serum levels were low for TT3 in 1 patient, for fT3 in 8
patients, for fT4 in 3 patients, and for Tg in 1 patient; serum TSH was high in 1
patient. At the end of study, serum levels were low for TT3 in 2 patients, for
TT4 in 2 patients, for fT3 in 9 patients, for fT4 in 4 patients, for TSH in 2
patients, and for Tg in 3 patients. At the start of the study, only TSH and Tg
levels could be detected in peritoneal dialysate; other parameters could not be
measured. One year later, levels of TSH had decreased in 6 patients and increased
in 3 patients, and Tg had increased in 8 patients, compared with baseline levels.
To determine the effect of CAPD, baseline results were compared with mean levels
at the end of the study. Although the mean levels of all parameters, except Tg,
had decreased after one year, only the decrease in serum TSH was statistically
significant. On the other hand, only the levels of Tg increased significantly in
peritoneal dialysate. The mean value of thyroid volume also decreased after a
year, but all values were within the normal range, and the decrease was not
significant. No correlation was found between dialysis duration and any parameter
after one year. In conclusion, we found a decrease in serum thyroid hormones,
thyroid volume, and TSH in chronic peritoneal dialysis patients. We suggest that
the low TSH levels cannot be explained by loss in peritoneal dialysate and may be
due to impairment of pituitary function.
PMID- 10682116
TI - Response to early measles-mumps-rubella vaccination in infants with chronic renal
failure and/or receiving peritoneal dialysis.
AB - Achieving immunity to childhood viral infections before renal transplantation is
crucial. However, children with chronic renal failure (CRF) may respond poorly to
vaccination, making it difficult to achieve immunity before transplantation,
particularly if they will require transplantation at a young age. To address this
problem, we developed a protocol of early measles-mumps-rubella (MMR) vaccination
in infants with CRF. Nine infants received MMR vaccine at a mean age of 11.6 +/-
2.5 months. When vaccinated, 6 of the children (67%) were on peritoneal dialysis,
and 3 (33%) had CRF [glomerular filtration rate (GFR) < 30 mL/min/1.73 m2]. Eight
patients were later transplanted at a mean age of 16.8 +/- 4.8 months. Titers
were measured before transplantation in all patients. Response to vaccination was
excellent, with 89% developing immunity to measles, 88% developing immunity to
mumps, 100% developing immunity to rubella, and 88% developing immunity to all
three components of the vaccine. These response rates were equivalent to, or
slightly better than, those previously reported by Schulman for older children
(19 +/- 6 months) on dialysis: 80% for measles, 50% for mumps, 100% for rubella,
and 30% for all three components. We conclude that early MMR vaccination induces
immunity in most infants with CRF, even those on peritoneal dialysis. Response
rates are similar to those previously reported in older children. This approach
may help to facilitate transplantation in young infants by achieving immunity
earlier than traditional vaccination schedules.
PMID- 10682117
TI - Effects of recombinant human erythropoietin on physiological inhibitors of
coagulation in children on continuous ambulatory peritoneal dialysis.
AB - The effects of recombinant human erythropoietin (rHuEPO) on plasma and peritoneal
effluent levels of antithrombin III (AT-III), protein C (PC) activity, and
protein S (PS) activity were evaluated in 10 uremic children on continuous
ambulatory peritoneal dialysis (CAPD). The findings were compared with values
obtained from ten healthy children. Levels of AT-III and of PC and PS activity in
plasma and peritoneal effluent were measured before, and at 8 and 12 weeks after,
rHuEPO treatment. Baseline levels of AT-III and PC activity in plasma were lower
than the control values. Levels of PC activity increased during the trial, while
levels of AT-III remained unchanged, and levels of PS activity decreased.
Baseline levels of PC activity in peritoneal effluent were lower than those
obtained during rHuEPO treatment, while no change in peritoneal levels of PS
activity and AT-III was observed after rHuEPO treatment. A significant positive
correlation was seen between plasma and peritoneal levels of PC activity at
baseline. A significant positive correlation was also seen between plasma levels
of PS activity and hemoglobin at week 12, and a significant negative correlation
between plasma levels of AT-III and albumin at week 8. No correlation was found
between the plasma natural coagulation inhibitors and CAPD duration. These
results suggest that plasma PS activity can be decreased, and plasma PC activity
increased, by rHuEPO treatment in children.
PMID- 10682118
TI - Effects of recombinant human erythropoietin on fibrinolytic system in children on
continuous ambulatory peritoneal dialysis.
AB - We studied tissue plasminogen activator (t-PA) and plasminogen activator
inhibitor 1 (PAI-1) levels in plasma and peritoneal effluent in 10 children on
continuous ambulatory peritoneal dialysis (CAPD) before, and 8 and 12 weeks
after, treatment with recombinant human erythropoietin (rHuEPO). Plasma t-PA and
PAI-1 levels were lower in patients than in controls during the study. The plasma
t-PA levels were increased by rHuEPO treatment. Although PAI-1 levels showed a
tendency to increase in the early phase of rHuEPO treatment, they later returned
to near baseline levels. Peritoneal effluent t-PA levels were decreased at week 8
of treatment, but returned to baseline levels at week 12. Peritoneal effluent PAI
1 levels were not changed by the rHuEPO treatment. No correlation was observed
between levels of t-PA and PAI-1 in plasma and in peritoneal effluent. No
correlation was seen between plasma PAI-1 levels and duration of CAPD. A
significant negative correlation was found between the plasma PAI-1 levels and
hemoglobin levels at week 8 and week 12. These results suggest that plasma t-PA
levels can be increased by rHuEPO treatment, while plasma PAI-1 levels are
associated with hemoglobin levels.
PMID- 10682119
TI - Middle molecules in peritoneal equilibration test as a marker of peritoneal
stress in children on continuous peritoneal dialysis.
AB - At 1 month, 3 months, 6 months, and more than 6 months after healed peritonitis,
we evaluated repeated peritoneal equilibration tests (PETs) for small molecules
such as urea, and middle molecules such as cystatin C, beta 2-microglobulin, and
alpha 1-microglobulin. We analyzed a total of 104 PETs in 21 children aged 1.7
18.6 years (median: 9.9 years). Equilibration quotients (D/P)--that is, substrate
concentration in dialysis fluid (D) divided by substrate concentration in plasma
(P)--were calculated after a dwell time of 4 hours. The D/P for urea did not
change after healed peritonitis. In a cross-sectional study, the D/P for middle
molecules showed an increase in peritoneal permeability between 3 months and 6
months after a healed peritonitis. In a consecutive follow-up of 4 patients for
more than 6 months, beta 2-microglobulin and, more impressively, alpha 1
microglobulin showed a statistically significant increase in D/P (p < 0.05) 3
months after a healed peritonitis. All differences seen were completely
reversible after more than 6 months, showing that peritoneal function is rather
stable if peritonitis is healed. It is noteworthy that peritoneal dysfunction
lasts for up to 6 months after a completely healed peritonitis. This period might
be a vulnerable phase in continuation of peritoneal dialysis.
PMID- 10682120
TI - Residual peritoneal volume and body size in children on peritoneal dialysis.
[Members of the Mid European Pediatric Peritoneal Dialysis Study Group (MEPPS)].
AB - Residual peritoneal volume may play an important role in dialysis efficacy and
abdominal compliance in patients on chronic peritoneal dialysis (CPD). In
children on CPD, the relationship between residual peritoneal volume and
different measures of body size, as well as the day-to-day variability of
residual volume, have not been established. We therefore investigated, on two
consecutive days, residual peritoneal volume in 25 children on CPD, using the
dextran dilution technique. Residual volume was linearly correlated with body
size. Residual volume was independent of body size when normalized to body
surface area, but decreased with increasing body size when normalized to body
weight (r = -0.62, p < 0.001). Mean residual volume was 79 +/- 25 mL/m2, with an
intra-individual day-to-day coefficient of variation of 21% +/- 15%. Residual
volume was not correlated with the duration of PD, frequency of peritonitis, or
peritoneal permeability as estimated by D/P creatinine or D/D0 glucose. In
conclusion, residual peritoneal volume is constant across the pediatric age range
when normalized to body surface area. It accounts for approximately 8% of the
usual fill volume in patients on CPD. Residual volume is not a major confounder
of the transport status estimation obtained by peritoneal equilibration test.
PMID- 10682121
TI - Can dialysis adequacy be achieved by tailoring the dialysis prescription in an
Asian pediatric population on nightly intermittent peritoneal dialysis?
AB - This study was undertaken to determine whether tailoring the dialysis
prescription in Asian children on nightly intermittent peritoneal dialysis
(NIPD), without adding high-dose therapy for cost-savings purposes, was able to
achieve dialysis adequacy and improvement in nutrition. Eight children (age
range: 5.5-20 years) on NIPD for a mean of 2.1 +/- 0.6 years, were studied at
baseline and at 3 months and 9 months after their dialysis dose was tailored.
Dialysis adequacy was measured by weekly Kt/Vurea and creatinine clearance (CCr).
Fat-free mass (FFM) and percent body fat (%FAT) as measured by bioelectrical
impedance, together with anthropometric measurements, serum total protein, and
albumin, were used as indicators of nutrition. After the dialysis prescription
was tailored, the mean weekly Kt/Vurea increased from 1.89 +/- 0.35 to 2.12 +/-
0.54 at 9 months, and total CCr increased from 36.4 +/- 11.51 L/1.73 m2 to 48.30
+/- 14.30 L/1.73 m2. The increase occurred despite a decline in residual renal
function and was attributable to significant improvements in the peritoneal
clearances of urea and creatinine (p < 0.05). The mid arm muscle circumference
(MAMC) increased significantly (p = 0.006), while FFM increased from 25.68 +/-
7.92 kg to 26.95 +/- 9.83 kg, and %FAT decreased from 21.56% +/- 8.41% to 18.66%
+/- 8.16%. The increase in FFM correlated significantly with a decrease in serum
creatinine (r = -0.94, p = 0.005). In conclusion, tailoring the dialysis
prescription in NIPD, without adding high-dose therapy, resulted in a trend of
improvement in dialysis adequacy and some nutritional parameters.
PMID- 10682122
TI - Retroviruses et opportunistic infections '99.
PMID- 10682123
TI - Analysis of hepatitis B virus quasispecies changes during emergence and reversion
of lamivudine resistance in liver transplantation.
AB - This report describes nucleotide sequence analysis of part of the polymerase gene
of hepatitis B virus (HBV) during the development of lamivudine-resistant HBV in
five patients who received lamivudine treatment in conjunction with liver
transplantation. Samples from patients were analysed before, during and after
drug treatment in conjunction with serum HBV quantification by PCR. Lamivudine
resistance was found to be associated with L526M and M550V changes in two
patients and M550I change in three patients. Other changes associated with
lamivudine resistance in some patients were V509I, A546V, S565A and A568T. The
effects on HBV surface antigen are also described. Some patients were
subsequently treated with famciclovir and/or ganciclovir with variable outcomes.
In two out of three patients who stopped lamivudine treatment, reversion (partial
or complete) to wild-type virus was observed after about 5 months. In contrast, a
complex mixture of mutant viruses emerged in a third patient who stopped
lamivudine treatment.
PMID- 10682124
TI - Interferon-alpha therapy exerts selective pressure on hepatitis C virus
quasispecies equilibrium.
AB - Two patients with chronic hepatitis C virus (HCV) genotype 2b infection were
studied. They responded biochemically to interferon (IFN) but had early
virological and later biochemical relapse. The HCV quasispecies equilibrium in
these patients was studied by a combination of cloning, sequencing and
construction of phylogenetic trees. Another patient with chronic HCV genotype 2b
infection was followed every 6 months for 30 months (including one episode of
biochemical exacerbation) to serve as the control. Quasispecies equilibrium
drifted during IFN therapy but moved back in the direction of the original
equilibrium during biochemical relapse. In the control patient, there was no
significant drifting throughout the follow-up period. These data suggest that IFN
therapy exerts selective pressure on HCV quasispecies equilibrium.
PMID- 10682125
TI - Stavudine resistance: an update on susceptibility following prolonged therapy.
AB - The current report summarizes the available published and unpublished data from
several investigators on resistance in clinical isolates following prolonged
stavudine therapy. Results suggest that stavudine resistance is both modest in
degree and infrequent in appearance. Phenotypic evaluation of 61 patients on
stavudine therapy showed only modest changes in drug sensitivity following up to
29 months of treatment. The post-treatment isolates from 15 patients exhibited an
increase in EC50 value > fourfold (level above variability of assay) when
compared with the corresponding pretreatment isolates. However, the vast majority
(11) of these pretreatment isolates either had unexpectedly low EC50 levels
and/or had post-treatment isolates that lacked any amino acid changes within
their reverse transcriptase (RT) gene to account for the observed change in
sensitivity. Of the four remaining isolates, two appeared to have a multi
resistant phenotype to several nucleoside analogues and two had no detectable RT
amino acid changes to account for the observed change in stavudine sensitivity.
To date, clinical HIV-1 isolates displaying stavudine-specific resistance have
yet to be reported. Furthermore, full or partial RT sequence analysis of 194 post
treatment isolates failed to identify any consistent amino acid changes. The
strain-specific V75T mutation reported to confer stavudine resistance to the HXB2
HIV-1 strain in vitro, was found in only six isolates and did not correlate with
stavudine resistance. This low incidence of stavudine resistance is in striking
contrast to that observed with other nucleoside analogues and further supports
the use of stavudine in first-line combination therapy for HIV patients.
PMID- 10682126
TI - Induction and maintenance treatment regimens for HIV-1 infection in vitro.
AB - Can aggressive anti-human immunodeficiency virus (HIV) induction regimens be
simplified after sufficient virus suppression is achieved? In vitro studies were
conducted to evaluate the hypothesis that aggressive induction regimens could be
followed by less aggressive maintenance regimens. A clinical HIV-1 isolate and
lymphoblastoid cell line (H9) were employed. Virus multiplicities were varied, as
were drug inhibitory concentrations (IC90, IC99) and induction periods (1, 2 and
3 weeks) of a three-drug regimen (zidovudine plus lamivudine and indinavir),
following which maintenance regimens (no drug, zidovudine alone, indinavir alone,
zidovudine plus lamivudine) were employed. After 1 week inductions at IC99
concentrations, viral rebound occurred on none or one-drug maintenance regimens
but not on a two-drug regimen. After 2 week inductions, viral rebound occurred
with no-drug maintenance, but not with one- and two-drug regimens. After 3 week
inductions, viral rebound did not occur in zero-, one-, or two-drug maintenance
regimens, although HIV-1 DNA persisted in cultured cells. These studies suggest
that although some induction-maintenance regimens will fail, after a sufficient
period of HIV-1 suppression with a three-drug antiretroviral regimen, maintenance
on fewer drugs may be feasible.
PMID- 10682127
TI - Quality of life outcomes of saquinavir, zalcitabine and combination saquinavir
plus zalcitabine therapy for adults with advanced HIV infection with CD4 counts
between 50 and 300 cells/mm3.
AB - BACKGROUND: Benefits in patient health-related quality of life (HRQL) have not
yet been demonstrated for combination antiretroviral therapy with protease
inhibitors and nucleoside analogues. This double-blind study evaluated
zalcitabine or saquinavir monotherapy and combination saquinavir plus zalcitabine
therapy on HROL of human immunodeficiency virus (HIV)-infected adults. METHODS:
940 HIV-infected patients (CD4 counts 50-300 cells/mm3) who had discontinued
zidovudine therapy (for intolerance or treatment failure) were randomized to one
of three regimens: zalcitabine 0.75 mg every 8 h; saquinavir 600 mg every 8 h; or
combination zalcitabine 0.75 mg plus saquinavir 600 mg every 8 hours. HRQL was
measured at baseline, 24 and 48 weeks using the Medical Outcome Study HIV Health
Survey (MOS-HIV). The primary endpoints were the physical and mental health
summary scores (PHS; MHS) of the MOS-HIV as well as a global visual analogue
scale (VAS) score. RESULTS: After 24 weeks, the zalcitabine-treated patients
demonstrated significantly greater decreases in PHS scores (-4.4 +/- 0.6;
saquinavir: -1.3 +/- 0.6; zalcitabine plus saquinavir: -1.7 +/- 0.6; P < 0.0001)
and MHS scores (-2.2 +/- 0.5; saquinavir: -1.0 +/- 0.5; zalcitabine plus
saquinavir: -0.5 +/- 0.5; P = 0.032) compared to saquinavir and zalcitabine plus
saquinavir treated patients. No differences were observed on the VAS (P = 0.172).
Nine of 10 MOS-HIV subscales demonstrated results consistent with the primary
endpoints. After 48 weeks, a statistically significant difference between the
saquinavir-treated groups and the zalcitabine monotherapy group was observed for
PHS scores (zalcitabine: -5.8 +/- 0.6; saquinavir: -4.1 +/- 0.6; zalcitabine plus
saquinavir: -3.5 +/- 0.6; P = 0.014). CONCLUSIONS: Saquinavir monotherapy and
combination saquinavir plus zalcitabine demonstrated a benefit in HRQL relative
to zalcitabine monotherapy in patients with prior zidovudine therapy. The HRQL
findings are concordant with improved survival and reduced clinical progression
of HIV infection found in this study.
PMID- 10682128
TI - Presence of genotypic resistance in nucleoside analogue-treated HIV-1-infected
patients with undetectable viral load.
AB - Patients harbouring drug-resistance viruses usually suffer a rise in serum
viraemia after a variable period of time. We have investigated the relationship
between the appearance of resistant genotypes and the viral load of each patient
after treatment. Our objective was to assess the association between human
immunodeficiency virus (HIV) RNA plasma levels and the number of drug resistance
associated point mutations after treatment. A total of 150 patients from three
reference centres in Spain (Madrid, Barcelona and Seville) from a previous study
(Erase Study) were included. Patients had at that time undergone antiretroviral
treatment with nucleoside analogues for at least 1 year (zidovudine/didanosine;
zidovudine/zalcitabine; zidovudine/zalcitabine/lamivudine;
zidovudine/didanosine/lamivudine). In this study, plasma viraemia in these
patients was quantified and a line probe assay was used to determine the genotype
of the virus. Viral load was significantly higher in patients harbouring virus
with more than three mutations than in those individuals who harboured wild-type
strains (P < 0.05). Surprisingly, when patients with viral load < 500 copies/ml
(13/150) were analysed, only two carried wild-type strains, whereas three had
virus with more than three point mutations. The viral load of six samples was
assayed using an ultrasensitive test (detection limit < 20 copies/ml). Of the
three samples where viral load was < 20 copies/ml, one patient harboured wild
type virus, whereas two carried mutant virus strains. These results suggest that
even in patients with undetectable viral loads by conventional methods, viral
replication may continue and mutations develop. Therefore, standard values of
plasma viraemia for measuring the effectiveness of the treatment should be
reconsidered when patients are on antiviral regimens of just two or three
nucleoside analogues.
PMID- 10682129
TI - Acute hypersensitivity with delavirdine.
PMID- 10682130
TI - Finding a role for zalcitabine in the HAART era.
AB - Zalcitabine (ddC) is a nucleoside analogue reverse transcriptase inhibitor with
demonstrated clinical benefit in combination use. More widespread use of
zalcitabine has been limited by a number of factors including peripheral
neuropathy and three times daily dosing. However, screening for the risk factors
for peripheral neuropathy may enable a reduction in the incidence of neuropathy
to below 10%. Additionally, new data on the use of zalcitabine twice daily
suggest, based on the long intracellular half-life of the active triphosphate,
that this is feasible. Additionally, while limited data exist for zalcitabine in
true HAART combinations, data from small trials suggest a similar proportion of
responders to standard HAART regimens.
PMID- 10682131
TI - Meta-analysis of antiretroviral effects on HIV-1 RNA, CD4 cell count and
progression to AIDS or death.
AB - There is uncertainty as to how the effects of antiretroviral treatments on human
immunodeficiency virus type 1 (HIV-1) RNA levels and CD4 cell counts can predict
reductions in clinical progression to AIDS or death. A meta-analysis was
conducted for 27 pairwise comparisons of antiretroviral treatments in 15
randomized trials of antiretroviral treatments. For each trial, three measures of
treatment effect were used: (i) 16 week change from baseline in HIV-1 RNA; (ii)
16 week change from baseline in CD4 cell count; and (iii) rate of clinical
progression. Treatments which caused greater increases in CD4 cell count and
greater reductions in HIV-1 RNA were more effective at reducing the rate of
clinical progression (P < 0.05 for each comparison). However, there was
variability in the consistency of this correlation between different trials and
treatments. The results support the use of both CD4 count and HIV-1 RNA levels as
the primary markers of the efficacy of antiretroviral treatment.
PMID- 10682132
TI - Management of antiretroviral therapy for HIV infection: modelling when to change
therapy.
AB - OBJECTIVE: To evaluate four strategies for monitoring plasma HIV RNA levels
and/or resistance genotypes to decide when to change antiretroviral therapy. The
strategies include: (i) 1997 guidelines recommending a therapy switch when plasma
RNA exceeds a threshold level; (ii) a viral load policy, using a fixed increase
in viral load as the trigger; (iii) a genotype policy, requiring a smaller viral
rebound than (ii) and detection of genotypic resistance before switching; and
(iv) a proactive policy, switching drug regimens at a predetermined time if viral
load has not rebounded. DESIGN AND SETTING: A Monte Carlo simulation tracks
patients' viral loads and presence of opportunistic infection during therapy. The
model uses clinical and virological data and statistical variation in patient
parameters for the evaluation of therapeutic strategies. MAIN OUTCOME MEASURES:
To determine which strategies minimize viral rebound detection delay while
maintaining a low (prespecified) probability of switching therapy before rebound.
RESULTS: 1997 Guidelines and the viral load policy create lengthy delays in
detection of rebound, particularly when patients are drug-naive and the detection
limit of the viral load assay is 500 copies/ml. A detection limit of 20 copies/ml
decreases this delay substantially. Genotyping achieves only minor additional
delay reductions. Of the strategies tested, the proactive policy leads to the
shortest delays. CONCLUSIONS: This model indicates that prolonged periods may be
required for viral load to rebound to detectable levels following prolonged
suppression. Proactive switching produces the best outcome in our model because
it may reduce the duration of viral replication under pressure of a failing
regimen before detection of viral rebound. This strategy should be evaluated in
clinical trials.
PMID- 10682133
TI - Improvement in immune function due to treatment with indinavir despite severe
immune deficiency.
AB - To study the virological, immunological and clinical effects of the protease
inhibitor indinavir in human immunodeficiency virus (HIV)-infected patients with
CD4 counts < 50 cells/mm3, indinavir was added to prior treatment with nucleoside
analogues in a prospective open-label study in 23 HIV-infected patients with
median CD4 count of 10 cells/mm3 and median serum HIV-1 RNA load of 27,508
copies/ml. Addition of indinavir induced a decrease in HIV-1 RNA levels to < 400
copies/ml in 15 patients that was maintained until week 36 of the study in 8
(35%) patients. The median increase in CD4 cell counts was 92 cells/mm3 (range 55
258 cells/mm3) and in CD8 counts was 245 cells/mm3 (range 51-1552 cells/mm3) at
week 30. The treatment induced a significant CD8 T cell expansion, consisting in
the first 6 weeks of predominantly memory CD45RO+ cells and followed by expansion
of naive cells from week 12 on, and a significant decrease in the proportion of
activated CD8/CD38 cells. In addition, significant increases in T cell
proliferation following stimulation with phytohaemagglutinin and significant
decreases in the rates of spontaneous apoptosis of CD4+ and CD8+ T cells were
observed. In conclusion, the addition of indinavir induced restoration of both
memory and naive CD8 T cells. Corresponding evidence of improving T cell
function, as assessed by enhanced lymphoproliferative capacity and diminished
propensity to undergo apoptosis, provides evidence for treatment-induced
regeneration of immune function even in patients with severe immunodeficiency.
PMID- 10682134
TI - Prediction of HIV-1 RNA suppression and its durability during treatment with
zidovudine/lamivudine.
AB - To predict the probability of long-term viral suppression during treatment with
zidovudine and lamivudine, human immunodeficiency virus type 1 (HIV-1) RNA values
were retrospectively pooled for 1083 patients from six randomized, double-blind
clinical trials. All analyses of HIV-1 RNA were obtained using the Roche Amplicor
assay or its earlier prototype. Time to loss of response was evaluated by Kaplan
Meier analysis; Cox proportional hazards models were used to assess the influence
of baseline variables. Among 523 patients with < or = 6 months of prior
zidovudine treatment, the probability of HIV-1 RNA suppression below 400
copies/ml at 48 weeks was 71% in those with baseline HIV-1 RNA < 5000 copies/ml,
but only 14% in those with HIV-1 RNA between 50,000 and 200,000 copies/ml. Among
560 patients with > 6 months of prior zidovudine treatment, the rates of
sustained viral suppression were lower, but also significantly associated with
the baseline HIV-1 RNA. Multivariate analyses showed no independent effect of CD4
cell count, age, sex, race, or CDC disease stage on the probability of sustained
HIV-1 RNA suppression. When patients with < or = 6 months of prior therapy were
stratified based on the magnitude of HIV-1 RNA nadir achieved during treatment,
those who reached a nadir of < 400 copies/ml retained this response for
significantly longer time periods than the ones who only achieved partial viral
suppression. In conclusion, baseline HIV-1 RNA levels and the duration of prior
zidovudine therapy strongly predict the antiretroviral efficacy of
zidovudine/lamivudine. The baseline parameters should influence the choice of the
antiretroviral regimen.
PMID- 10682135
TI - Diminished HIV-1 sensitivity to stavudine in patients on prolonged therapy occurs
only at low levels and cannot be attributed to any single amino acid substitution
in reverse transcriptase.
AB - To study the extent to which phenotypic resistance to stavudine occurs under
therapy, we studied 18 pairs of human immunodeficiency virus type 1 (HIV-1)
isolates from patients both prior to and following 24-48 weeks of treatment with
stavudine monotherapy or stavudine in combination with either didanosine or
lamivudine. We also used a nested polymerase chain reaction (PCR) assay to probe
for the presence of specific mutations associated in culture with stavudine
resistance. The results showed that resistance to stavudine (approximately 3-10
fold) was observed in nine of ten cases of monotherapy, in three of four cases of
therapy involving both stavudine and didanosine, and in two of four cases
involving stavudine and lamivudine. Viruses from the four patients receiving
stavudine plus didanosine became resistant to didanosine in only one instance
while the use of lamivudine plus stavudine yielded resistance to lamivudine each
time. Whereas changes in the reverse transcriptase (RT) genes of resistant
isolates were frequently observed, two mutations, previously identified with
stavudine resistance in tissue culture (i.e., V75T and I50T), could not be
identified in the clinical samples by either direct sequencing of the RT gene or
by PCR amplification. Thus, resistance to stavudine can occur, albeit at low
levels, in the context of prolonged therapy with this drug but is not associated
with specific mutations in HIV RT at either codons 75 or 50 in clinical samples.
PMID- 10682136
TI - Genotypic and phenotypic resistance to stavudine after long-term monotherapy. BMS
020 Spanish Study Group.
AB - Protocol BMS 020 was a double-blind, prospective clinical trial in which two
different doses of stavudine (20 and 40 mg twice daily) were compared in human
immunodeficiency virus (HIV)-infected patients with previous exposure to
zidovudine for longer than 16 weeks. Genotypic and phenotypic resistance to both
zidovudine and stavudine were examined after at least 2 years of stavudine
monotherapy. None of 35 tested individuals harboured the codon 50 and/or 75
mutations previously described to be associated with stavudine resistance.
However, more than 80% of the individuals carried mutations associated with
zidovudine resistance, despite all these patients having stopped zidovudine at
least 2 years earlier. Significant phenotypic resistance to stavudine was
observed only in 2 of 5 tested individuals, although IC50 values were increased
only 6.6- and 9.2-fold, respectively. These two patients had suffered a decline
in their CD4 count, and one of them had high levels of plasma viraemia. The
sequence analysis of the reverse transcriptase (RT) gene (aa 30 to 240) in these
five patients revealed no changes that could be involved in stavudine resistance.
In contrast, and despite having stopped treatment with zidovudine more than 2
years before, phenotypic resistance to zidovudine was observed in all five
subjects, with IC50 values raised by more than 75-fold in all of them. Moreover,
all harboured codon substitutions within the RT gene associated with zidovudine
resistance, and these mutations remained in viral genomes examined after virus co
culture, suggesting that they provided some biological advantage to mutants, even
in the absence of drug pressure. In conclusion, both genotypic and phenotypic
resistance to stavudine seem to be a rare event in patients exposed to the drug,
even after long periods of exposure.
PMID- 10682137
TI - Quantitative p24 antigenaemia for monitoring response to antiretroviral therapy
in HIV-1 group O-infected patients.
AB - Failure to recognize infection caused by human immunodeficiency virus type 1 (HIV
1) group O variants has been described using both serological and genetic
techniques. Moreover, the monitoring of response to antiretroviral therapy is
difficult in persons carrying this infection since most currently available tests
for quantifying viral load are not reliable for group O viruses. Considering the
low level of divergence between the p24 proteins of group M and O viruses, we
have examined whether the quantification of circulating p24 antigenaemia might be
used as a surrogate marker of response to therapy in three subjects with HIV-1
group O infection treated with antiretroviral drugs. In summary, all three
patients showed a significant decline in circulating plasma p24 antigenaemia,
although only one achieved undetectable levels. The decline in p24 antigenaemia
was parallel to an increase in the CD4 count and was associated with an
improvement in clinical status.
PMID- 10682138
TI - Anti-HIV antiviral activity of stavudine in a thymidine kinase-deficient cellular
line.
AB - Stavudine (d4T) is a potent inhibitor of human immunodeficiency virus type 1 (HIV
1) reverse transcriptase. It is known that stavudine is metabolized in cells to
the mono-, di- and triphosphate nucleotides but the enzymes responsible for its
phosphorylation are as yet unidentified. In particular, there are conflicting
results concerning the role of thymidine kinase 1 (TK1) in stavudine metabolism.
To gain new insights into this phenomenon we analysed the antiviral activity of
stavudine in a TK1-deficient, resistant cell line. The results indicate that TK1
is responsible for the phosphorylation of stavudine but it is not the only enzyme
involved in its activation. The other enzyme(s) that might be involved in the
metabolism of stavudine, however, are not able to phosphorylate stavudine with
the same efficiency as TK1. Since it has been shown that prolonged treatment with
zidovudine may induce an in vivo defect in TK1 activity, it is tempting to
speculate that patients treated for a long time with zidovudine could be
resistant to further treatment with stavudine.
PMID- 10682139
TI - Loss of lamivudine resistance in a zidovudine and lamivudine dual-resistant HIV-1
isolate after discontinuation of in vitro lamivudine drug pressure.
AB - We examined the in vitro phenotypic and genotypic profiles of an extensively
passaged human immunodeficiency virus type 1 clinical isolate which has been
selected for lamivudine resistance, with an M184V mutation in a zidovudine
resistant genetic background, and then cultured with zidovudine alone. Our
passaging strategy led to a decrease in lamivudine IC50 values, which were
comparable to those prior to lamivudine exposure, and the genotypic restoration
of the wild-type sequence at codon 184 of reverse transcriptase.
PMID- 10682140
TI - Kinetics of productive and latent HIV infection in lymphatic tissue and
peripheral blood during triple-drug combination therapy with or without
additional interleukin-2.
AB - OBJECTIVE: To study decay rates of productively and latently infected cells in
peripheral blood and lymph nodes during triple antiretroviral therapy and the
possible impact of interleukin-2 (IL-2) on viral kinetics. METHODS: In this non
randomized study, nine antiretroviral-naive HIV-positive patients received either
saquinavir hard gel capsules 2400 mg three times daily (group I; four patients)
or saquinavir soft gel capsules 1200 mg three times daily and IL-2 (group II), in
both cases together with two nucleoside analogues. Plasma viraemia and lymphocyte
subsets were analysed. Axillary lymph nodes were excised before and after 12
weeks of therapy. Lymph node sections were examined by in situ hybridization for
HIV RNA, and productively infected cells were counted. Infection rates of FACS
sorted CD3, CD4 lymph node and peripheral blood mononuclear cells were determined
by nested DNA PCR. RESULTS: Baseline plasma HIV RNA levels ranged from < 25 to >
1 x 10(6) copies/ml and remained undetectable throughout the study in one patient
in group I. Plasma viraemia became undetectable after 3 months in four patients
(three in group I). Productively infected cells were markedly reduced in the
follow-up lymph node specimens. HIV DNA-positive CD4 T cells were reduced in
lymphoid tissue and peripheral blood in all six evaluable patients. There were no
significant differences between the groups in the clearance rates of plasma virus
and of HIV DNA-positive cells. CONCLUSIONS: Combined antiretroviral therapy
rapidly suppressed active HIV replication in plasma and lymphoid tissue. Latently
infected cells were cleared at a slower rate. Viral clearance did not appear to
be markedly affected by additional IL-2 therapy.
PMID- 10682141
TI - Low plasma concentrations of indinavir are related to virological treatment
failure in HIV-1-infected patients on indinavir-containing triple therapy.
AB - All human immunodeficiency virus type 1 (HIV-1)-infected patients who started to
use indinavir (800 mg three times a day) as part of their triple drug regimen
were included in a study to determine the importance of low plasma concentrations
of indinavir as a cause of virological treatment failure. The indinavir
concentration and a number of patient characteristics at baseline were tested as
risk factors for virological treatment failure (defined as a viral load above 200
copies/ml after 24 weeks of treatment) in univariate and multivariate analyses;
65 patients were included. Virological treatment failure occurred in 36.9% of the
patients. Multivariate analysis showed that a low plasma concentration of
indinavir (odds ratio 0.1), a high viral load at baseline (odds ratio 2.6) and
pretreatment with another protease inhibitor (odds ratio 10.0) were independent
factors related to virological treatment failure. Monitoring of indinavir plasma
concentrations may be an important tool for the optimization of triple drug
combination therapy.
PMID- 10682142
TI - Evaluation of mixtures of wild-type HIV-1 and HIV-1 with resistance point
mutations against reverse transcriptase inhibitors.
AB - The presence of resistance-related mutations in 185 serial proviral DNA samples
from 108 HIV-infected patients was monitored using the line probe assay (LiPA).
The proportions of wild-type and mutant virus in each sample were determined.
Subsequent samples from the same patient were analysed. Resistance mutations were
detected in 58 of 108 patients studied (53.7%), 53 of 73 (72.6%) treated with
antivirals and 5 of 35 (14.2%) untreated. The mutations were against zidovudine
(51), lamivudine (1), zidovudine and lamivudine (4), zidovudine and zalcitabine
(1) and zidovudine and didanosine (1). Among the 58 patients with resistant
virus, 168 related mutations were observed: 161 to zidovudine (90 in codon 70, 25
in codon 41 and 46 in codon 215), 5 to lamivudine (codon 184), 1 to zalcitabine
(codon 69) and 1 to didanosine (codon 74). Mixtures of wild-type and resistant
mutants were detected in 76 of 90 (84.4%) mutated at codon 70, 28 of 46 (60.8%)
mutated at codon 215 and in 21 of 25 (84%) mutated at codon 41. The mutations at
codon 184 were mixtures of wild-type and resistant in 4 of 5 samples. The
agreement between LiPA and sequencing was 96.5%. LiPA was more sensitive for the
detection of mutants that were present at low frequency. The analysis of
sequential samples from the same patient allowed evaluation of the dynamics of
appearance of the resistant mutants.
PMID- 10682143
TI - Opportunistic infections shortly after beginning highly active antiretroviral
therapy.
AB - The clinical benefit of highly active antiretroviral therapy (HAART) has been
attributed to its suppression of viral replication and improvement in the CD4
lymphocyte count. However, the development of clinical symptoms secondary to
previously silent opportunistic pathogens shortly after beginning HAART has been
reported as a distinct clinical syndrome and seems to be associated with
inflammatory phenomena surrounding a rapid restoration of the immune system in
previously immunosuppressed patients. Herein, we report nine (3.6%) episodes of
opportunistic infections (OI) in 247 human immunodeficiency virus (HIV)-infected
patients undergoing HAART in a reference HIV/AIDS institution located in Madrid,
Spain. In all instances, OI clustered within the first 3 months after beginning
HAART. Episodes of cerebral toxoplasmosis (three cases), Pneumocystis carinii
pneumonia (two cases), and herpes zoster (two cases) occurred in persons without
a previous AIDS-defining illness, in addition a relapse of cytomegalovirus
retinitis and a rebound in Kaposi's sarcoma were seen, respectively, in another
two patients. Four of the nine subjects had a CD4 count above 200 cells/mm3
before HAART began. Of these, one developed Pneumocystis pneumonia and one other
cerebral toxoplasmosis. In conclusion, prophylaxis and close clinical monitoring
of HIV-infected patients should be considered for the first 3 months after
beginning HAART, even for subjects without severe immunosuppression.
PMID- 10682144
TI - Combination treatment for hepatitis C can be hazardous in patients co-infected
with HIV.
PMID- 10682145
TI - Antiviral drug resistance: from the laboratory to the patient.
PMID- 10682146
TI - Cytomegalovirus drug resistance.
AB - Clinical resistance of cytomegalovirus (CMV) against the currently licensed
antiviral drugs is becoming an increasingly recognized problem. This review
focuses on the molecular basis of resistance and describes mutations in the UL54
DNA polymerase leading to resistance against cidofovir, foscarnet and
ganciclovir. The review highlights two important developments in our appreciation
of resistance. Firstly, the use of more rapid molecular based assays to detect
genotypic resistance and secondly, the relationship between resistance profiles
in multiple organ systems of the same host. Finally, the changing face of CMV
disease in the era of highly active antiviral chemotherapy is considered with
respect to its impact on the frequency of CMV resistance in the clinic.
PMID- 10682147
TI - Hepatitis B virus antiviral drug resistance: from the laboratory to the patient.
AB - The development and application of nucleoside (and nucleotide) analogues for the
treatment of chronic hepatitis B infection will transform the management of this
condition. For instance, treatment with lamivudine effects a dramatic and
measurable reduction of serum virus titre. This is associated with biochemical
and histological improvements. Unfortunately, for the majority, replication
resumes when treatment is withdrawn. Prolonged lamividine treatment may be
associated with the emergence of drug-resistant species with specific polymerase
mutations. Compared with the observed rate for the development of drug resistance
observed during monotherapy of HIV infection, resistance is slow to emerge during
treatment of hepatitis B. The rate of emergence might be dependent on the rate of
infected hepatocyte turnover, which is extremely variable in chronic HBV
infection (and significantly slower than infected lymphocyte turnover during HIV
infection). Preliminary data suggest that pretreatment serum virus titre may be
an important predictor of the development of drug resistance, an observation
consistent with preexistance of the resistant virus in the hepatitis B virus
quasispecies. Akin to developments in antiviral treatment of HIV infection,
further progress in the treatment of chronic hepatitis B will depend on the
development of drugs for use in combination therapy.
PMID- 10682148
TI - Laboratory markers of antiviral activity.
AB - Quantitative assays for viral nucleic acids have been instrumental in monitoring
the response of patients to various antiviral therapies. The level of viraemia is
predictive of clinical outcome in that a reduced risk of progression to AIDS or
death was observed with lower plasma human immunodeficiency virus (HIV) RNA
levels. Rebound in viral levels often signals therapeutic failures, some of which
are associated with the development of drug resistance. Quantitative plasma
assays for HIV, hepatitis C virus (HCV), cytomegalovirus (CMV) and hepatitis B
virus (HBV) have been developed. Over time, modifications to these assays have
been required to meet new demands. For example, as antiviral therapies have
become more effective, HIV and HCV assays of greater sensitivity are required in
order to follow patients for longer periods of time and to fully assess the
extent of viral suppression. For HIV-1, a large percentage of patients treated
with combination therapies had viral loads that were below the detection limit of
the ultrasensitive assay (50 copies/ml). To assess the residual viral burden in
this patient population an assay to quantify HIV-1 proviral DNA in peripheral
blood mononuclear cells was developed. Studies to date indicate that proviral DNA
remains easily detectable despite undetectable plasma RNA and may be useful in
monitoring this patient population. To increase assay throughput, a new
generation of quantitative assays that will provide real-time detection and a 6
log10 detection range from a single amplification is under development.
PMID- 10682149
TI - Effective salvage therapy for HIV-1 infection--an unmet challenge.
PMID- 10682150
TI - Safety and efficacy of the neuraminidase inhibitor zanamivir in treating
influenza virus infection in adults: results from Japan. GG167 Group.
AB - The study was carried out to evaluate the therapeutic effects of zanamivir, a
highly selective, potent and specific inhibitor of influenza A and B virus
neuraminidases, in adult patients with acute influenza-like illness. Patients who
presented within 36 h of the onset of influenza-like symptoms were randomly
assigned to receive one of three treatments, twice daily, for 5 days: 10 mg
zanamivir powder for inhalation (zanamivir inhalation group), 10 mg zanamivir
powder for inhalation plus 6.4 mg zanamivir nasal spray (zanamivir inhalation
plus intranasal group) or placebo (placebo group). The primary end point was the
time to alleviation of the three major symptoms (fever, headache and myalgia).
The secondary end point was the time to alleviation of five influenza symptoms
(fever, headache, myalgia, cough and sore throat). One hundred and sixteen
patients with influenza-like illness were recruited to the study. No differences
were observed between the two groups of patients who received zanamivir
(inhalation group or inhalation plus intranasal group). Patients who received
zanamivir recovered significantly faster (median 3 days to recovery) than the
patients in the placebo group (median 4 days to recovery; P < 0.01). Topically
administered zanamivir was well tolerated. This study confirms that in adults,
topically administered zanamivir is well tolerated and is effective in reducing
the time to alleviation of influenza symptoms.
PMID- 10682151
TI - Zidovudine resensitization and dual HIV-1 resistance to zidovudine and lamivudine
in the delta lamivudine roll-over study.
AB - OBJECTIVE: To study zidovudine resensitization and dual resistance to
zidovudine/lamivudine in HIV-1 isolates from nucleoside reverse transcriptase
(RT) inhibitor-experienced patients during selective pressure exerted by
zidovudine/lamivudine combination therapy. DESIGN AND METHODS: HIV-1 isolates
from 29 patients receiving zidovudine/lamivudine combination therapy in the Delta
roll-over study were analysed at entry and during a 1 year follow-up period for
phenotypic susceptibility to zidovudine and lamivudine in the ANRS PBMC assay.
The RT gene from codon 20 to 230 and at codon 333 was analysed by nucleotide
sequencing of the corresponding isolates. RESULTS: HIV-1 isolates from 23 of the
29 patients were phenotypically resistant to zidovudine at baseline; 61% of these
patients showed significant zidovudine resensitization during follow-up. The
zidovudine IC50 value correlated positively with log10 plasma HIV-1 RNA (P =
0.02) and negatively with the CD4 cell count (P = 0.004). Zidovudine
resensitization (related to acquisition of the M184V mutation) was transient,
with evolution towards dual resistance to zidovudine and lamivudine in 20 of the
29 patients. The phenotype of certain dually resistant isolates coincided with
the emergence of multiple mutations in the 5' part of the RT gene. CONCLUSIONS:
M184V-mediated zidovudine resensitization of HIV-1 is transient in most patients
who are given zidovudine/lamivudine combination therapy when zidovudine
resistance has already emerged. The subsequent evolution towards dual phenotypic
resistance to zidovudine/lamivudine corresponds to complex genotypic profiles.
PMID- 10682152
TI - AVANTI 1: randomized, double-blind trial to evaluate the efficacy and safety of
zidovudine plus lamivudine versus zidovudine plus lamivudine plus loviride in HIV
infected antiretroviral-naive patients. AVANTI Study Group.
AB - The objective of this randomized double-blind, placebo-controlled trial was to
investigate the effect of combination antiretroviral therapy on plasma HIV-1 RNA
as measured by HIV RNA PCR and to assess the safety and tolerability of such
regimens. The trial was carried out in seven European countries, Australia and
Canada and involved antiretroviral-naive patients (n = 106) with CD4 counts
between 150-300 cells/mm3 (CDC group A) and 150-500 cells/mm3 (CDC group B/C).
Patients were randomly assigned to zidovudine (200 mg three times daily) plus
lamivudine (300 mg twice daily) or to zidovudine plus lamivudine plus loviride
(100 mg three times daily) for 52 weeks. The main outcome measures were degree
and duration of reduction of plasma HIV-1 RNA as measured by RNA PCR and the
development of drug-related toxicities sufficiently severe to warrant dose
modification, interruption or permanent discontinuation. A mild, though
statistically significant difference in favour of zidovudine plus lamivudine plus
loviride for log10 plasma HIV-1 RNA (P = 0.022), as compared to zidovudine plus
lamivudine, was observed using area-under-the-curve minus baseline (AUCMB). An
increase in CD4 cell count in the zidovudine plus lamivudine plus loviride group
was observed with a median improvement of 124 cells/mm3 at week 52 compared with
70 cells/mm3 in the zidovudine plus lamivudine group (P = 0.06). Both treatment
regimens were well tolerated.
PMID- 10682153
TI - In vitro selection and characterization of HIV-1 with reduced susceptibility to
PMPA.
AB - 9-(2-phosphonomethoxypropyl)adenine (PMPA) has demonstrated remarkable anti
simian immunodeficiency virus (SIV) activity in macaque models of SIV infection
and transmission prevention. Recently, PMPA and its oral prodrug, bis-POC PMPA,
have also shown potent anti-human immunodeficiency virus type 1 (HIV-1) activity
in Phase I clinical studies. In vitro experiments were performed to address the
resistance properties of PMPA. After eight passages in increasing concentrations
of PMPA, HIV-1IIIB was able to grow in the presence of 2 microM PMPA, fivefold
above the IC50 of PMPA for wild-type parental virus. Sequence analysis of the
reverse transcriptase (RT) genes from four of 15 RT clones demonstrated the
presence of a K65R substitution in RT and recombinant HIV expressing the K65R RT
mutation showed a threefold to fourfold increase in IC50 value for PMPA as
compared to wild-type. Additional experiments demonstrated that viruses
expressing other nucleoside-associated RT resistance mutations all showed wild
type or < threefold reduced susceptibility to PMPA in vitro. Interestingly,
lamivudine-resistant viruses expressing the M184V RT mutation showed wild-type to
slightly increased susceptibility to PMPA in vitro and addition of the M184V
mutation to HIV with the K65R mutation resulted in reversion to wild-type
susceptibility for PMPA. In agreement with the cell culture findings, Escherichia
coli-expressed K65R RT showed fivefold reduced susceptibility to PMPA
diphosphate, the active moiety of PMPA. Furthermore, in combination experiments,
PMPA with hydroxyurea showed synergistic inhibition of HIV replication in vitro.
The potent antiretroviral activity and favourable resistance profile of PMPA and
bis-POC PMPA are being further investigated in ongoing clinical trials.
PMID- 10682154
TI - A combination of nucleoside analogues and a protease inhibitor reduces HIV-1 RNA
levels in semen: implications for sexual transmission of HIV infection.
AB - Direct contact with semen is the major route of sexual acquisition of human
immunodeficiency virus (HIV) in homosexual and heterosexual partners of
seropositive men. In this study, we show that concentrations of HIV-1 RNA
molecules in plasma and semen of seropositive patients are related to the
duration and type of antiretroviral agents used in treatment. In patients treated
with zidovudine alone, 1, 3 and 6 months after the start of therapy, the mean HIV
1 load in plasma was reduced by 0.57, 0.38 and 0.21 log10 and in semen by 0.66,
0.50 and 0.15 log10, respectively. In patients treated with zidovudine plus
didanosine at months 1, 3 and 6, the mean decrease in plasma HIV-1 RNA was 1.40,
1.25 and 1.12 log10 and in semen 1.10, 1.41 and 1.32 log10, respectively. In
patients treated with a combination of a protease inhibitor and two nucleoside
analogues the mean log10 decrease was 1.77, 1.83, 1.71 and 2.38 log10 in plasma
and 1.17, 1.74, 2.19 and 3.02 log10 in semen at 1, 2, 3 and 4 months,
respectively. Treatment with a combination of a protease inhibitor and two
nucleoside analogues caused a dramatic decrease in cell-free HIV-1 RNA in semen,
which is a reliable measure of viral load. These findings could have implications
for the sexual transmission of HIV-1.
PMID- 10682155
TI - Effect of weekly adefovir (PMEA) infusions on HIV-1 virus load: results of a
phase I/II study.
AB - The compound 9-(2-phosphonylmethoxyethyl)adenine (adefovir; PMEA) is a potent
inhibitor of a number of viruses in vitro, such as human immunodeficiency virus
(HIV) type 1 and 2, herpes simplex virus (HSV) type 1 and 2, human papillomavirus
virus (HBV) and Epstein-Barr virus (EBV). Adefovir also proved to be effective in
vivo against feline immunodeficiency virus (FIV) in cats and simian
immunodeficiency virus (SIV) in rhesus monkeys. In an open, non-placebo
controlled trial the antiviral activity of weekly doses of adefovir in nine
patients with AIDS or AIDS-related complex was studied for a period of 11 weeks.
CD4 cell counts at baseline were between 10 and 450 cells/mm3, HIV-1 RNA levels
at baseline were between 24,210 copies/ml and 406,197 copies/ml. The drug was
administered intravenously at a dose of 1000 mg every week and plasma viral load
was assessed at multiple points during the study. Administration of adefovir was
tolerated well and no severe side effects were seen. The response to adefovir
treatment differed widely between patients. The increase in CD4 cell count at end
point ranged from -40 to 120 cell/mm3. The lowest HIV RNA levels were measured
after 3-5 days, showing an increase thereafter. The nadir in viral load was
achieved after 2 weeks, with a mean viral load decline of 0.7 from baseline. The
decrease of the HIV RNA level at end point ranged from -0.3 log10 to 1.8 log10
with a mean decrease of 0.4 log10. Our results indicate that adefovir given
intravenously once weekly has a short-lasting initial antiviral effect. The
effect of more frequent dosing requires further evaluation. If adefovir is to be
useful clinically, it needs to be combined with other antiviral agents.
PMID- 10682156
TI - Kinetics of beta-chemokine levels during anti-HIV therapy.
AB - Chemokines are pro-inflammatory cytokines that inhibit human immunodeficiency
virus type 1 (HIV-1) replication in vitro. We studied the kinetics of the beta
chemokines, macrophage inhibitory protein (MIP)-1 alpha, MIP-1 beta, RANTES, and
monocyte chemotactic protein (MCP)-1 in plasma during 12 months of antiretroviral
therapy in 26 HIV-1-infected patients and in 11 untreated subjects. Eleven
patients with moderate immunodeficiency had HIV-1 RNA levels < 50 copies/ml after
1 year, whereas 12 out of 15 patients with severe immunodeficiency had detectable
virus. At baseline, MCP-1 levels correlated positively with HIV-1 RNA and DNA
levels and inversely with CD4 cell counts. A reverse pattern was seen for the MIP
1 beta levels. No correlation was seen between MIP-1 alpha or RANTES and any of
the parameters. Also, there was a dichotomy between the different beta-chemokines
in response to therapy. Decreases of MCP-1 and RANTES levels were found, but no
durable changes of MIP-1 alpha and MIP-1 beta. The MCP-1 levels rebounded back to
baseline after 1 year in the patients who responded virologically, which could
possibly reflect an increased immune activation. The biological consequences of
the changes in beta-chemokines levels during antiretroviral treatment are still
unknown and deserve further studies.
PMID- 10682157
TI - Patients failing saquinavir therapy require an early change to indinavir before
HIV-1 viral load reaches high levels.
AB - Sequential use of antiretroviral therapy with protease inhibitors (PI) is
frequently prescribed owing to failure or intolerance of the first selected
agent. Controversial data exist about the virological and immunological outcome
of patients in whom a change to a second PI regimen is needed. A prospective
study of 113 HIV-positive patients (male, 84%; mean age 36 years; previous AIDS
defining event, 35%; previous antiretroviral therapy with nucleoside analogues,
94%) who started a saquinavir-containing regimen between March 1996 and March
1997 and had to change to indinavir (n = 79) owing to intolerance, failure or
medical criteria was performed. At the time of the switch, median CD4 cell count
was 221 cells/mm3 and the HIV RNA level was 3.98 log10 copies/ml. The rate of
viral suppression (HIV RNA levels below 200 copies/ml) was 40% at 3 months and
28% at month 6 after indinavir was instituted. In a logistic regression analysis,
only the baseline viral load [relative risk (RR), 2.85; 95% confidence interval
(CI), 1.31-6.05; P = 0.007] was statistically associated with the lack of viral
suppression on indinavir. Although there are not sufficient data about the best
therapeutic option if a change in PI-containing regimens therapy is considered,
this study supports the recommendation of an early change of the PI-containing
regimens, before the HIV-1 viral load reaches high levels.
PMID- 10682158
TI - Efficiency of drug resistance genotypic tests in specimens with low HIV viral
load.
AB - The early recognition of resistance to antiretroviral agents could allow a rapid
switch in therapy and therefore avoid the accumulation of mutations and reduce
the risk of cross-resistance. However, the efficiency of genotypic tests in
specimens with low viral load (VL) is severely compromised since human
immunodeficiency virus (HIV) RNA in these samples often goes unrecognized. The
frequency of results provided by a line probe assay (LiPA, Murex), a commercially
available drug resistance test and a home-made point mutation assay (PMA) for
recognizing the codon 151 multidrug-resistance mutation was examined in 664
plasma samples stratified with respect to VL values. Overall, 421 (63%) samples
could be interpreted by both LiPA and PMA. The sensitivity decreased as plasma VL
lowered: 89% for samples with VL > 10,000 HIV RNA copies/ml, 77% for those with
VL between 500 and 10,000 HIV RNA copies/ml and 37% for specimens with VL < 500
HIV RNA copies/ml. A good agreement existed comparing the sensitivity of the home
made PMA and LiPA. Although the former tends to produce more results, the
difference did not achieve statistical significance. Our results support that
new, more sensitive, HIV RNA extraction methods need to be implemented for the
rapid recognition of drug-resistant mutants in patients experiencing an early
rebound in plasma viraemia.
PMID- 10682159
TI - Different outcome in the first two patients with an HIV-1 multinucleoside drug
resistant T69SSS insertion in Spain.
AB - A novel multidrug-resistance mechanism has been described in human
immunodeficiency virus type 1 (HIV-1), which involves the insertion of 6 bp
between codons 69 and 70 in the reverse transcriptase (RT) gene. Herein, we
report the first two patients in Spain carrying viral populations with the 69-SS
insert coupled to the T69S mutation. Both patients were selected because of the
lack of signal at positions 69/70 in the LiPA RT test despite being reactive to
the remaining probes on the LiPA strip. The presence of the T69SSS complex was
confirmed by sequence analysis. A common feature for both subjects was their past
history with zidovudine monotherapy and zidovudine plus either didanosine or
zalcitabine later on in the presence of persistent virus replication. Remarkably,
the introduction of triple therapy in patient 1 soon after the emergence of the
insert-containing viral strain produced its total displacement, which correlated
with a sustained suppression in viral load.
PMID- 10682160
TI - Atherogenesis and its relationship to coronary risk factors.
AB - A new model for the development of atherosclerosis is emerging (1,2). This
development process, called atherogenesis, is now thought to begin with metabolic
dysfunction of the endothelial cells that line the innermost portion of the
arterial wall. Endothelial dysfunction precedes visible changes in endothelial
structure. Dysfunctional endothelium loses its ability to maintain vascular
smooth muscle relaxation and instead promotes vasospasm, chemotaxis and
inflammation, platelet aggregation, and diminished clot lysis. Endothelial
dysfunction appears to occur diffusely, rather than discretely, in affected
vessels. Accordingly, local anatomical interventions, such as bypass surgery or
angioplasty, can be expected to have only limited success in the treatment of
patients with atherosclerotic disease. More definitive treatments must be
directed at the risk factors initiating or enhancing atherogenesis. Such
interventions are more likely to be medical than surgical or mechanical. With
appropriate understanding of the underlying process of atherogenesis and its
clinical manifestations, such medical interventions can be carried out within the
boundaries of everyday practice.
PMID- 10682161
TI - Clinical diagnosis of lipid disorders.
AB - Atherosclerotic cardiovascular disease is a major health problem in the United
States. In particular, coronary heart disease (CHD) is the leading cause of death
in men and women in the United States, as well as in other industrialized
countries. Extensive observational epidemiologic data within and between
populations have strongly linked such various factors as untreated hypertension,
diabetes, cigarette smoking, and lipid abnormalities to the development of CHD.
With respect to lipoprotein parameters, elevated total and low-density
lipoprotein cholesterol (LDL-C) and low levels of high-density lipoprotein
cholesterol (HDL-C) have been strongly associated with CHD risk. Emerging
evidence suggests that other lipoprotein abnormalities also are associated with
premature CHD, including elevated levels of lipoprotein(a), triglyceride-rich
lipoproteins such as small very-low-density lipoproteins and intermediate-density
lipoproteins, small and dense LDL particles, and the magnitude of postprandial
lipemia. Extensive primary and secondary clinical trial evidence has established
that favorably altering dyslipidemias through diet and a variety of pharmacologic
agents produces clear improvements in CHD end points. The extent of this benefit
depends on the presence or absence of clinical atherosclerotic disease, as well
as other CHD risk factors, and the severity of one or more lipoprotein
abnormalities. CHD patients and individuals with multiple risk factors, but free
of clinical CHD, derive the greatest absolute benefit from lipid treatment
directed at reducing LDL-C. The dyslipidemias that impart high risk are severely
elevated LDL-C (> 200 mg/dL), combined high LDL-C and low HDL-C (< 35 mg/dL), and
combined hyperlipidemias (non-HDL-C > 200 mg/dL with low HDL). The purpose of
this review is to aid the primary care physician in identifying these important
dyslipidemias and to critically analyze the relative importance of various
lipoproteins on atherosclerotic risk.
PMID- 10682162
TI - Primary prevention of coronary disease.
AB - In 1995, the latest year for which statistics are available, heart disease,
cancer, and stroke continued to be the three leading causes of death in the
United States. Notably, however, a wealth of experience has confirmed that
hygienic interventions such as diet, exercise, weight loss, and smoking cessation
can reduce the toll from heart disease while also reducing the morbidity and
mortality associated with stroke and cancer. This chapter will describe the
rationale for the primary prevention of coronary heart disease (CHD), review the
basic concepts involved in cholesterol screening, and update the reader regarding
key preventive measures, such as diet, exercise, and smoking cessation. Also
highlighted will be recent clinical trial results suggesting the benefits of
lipid-lowering drugs in "high-risk" individuals who have not experienced a
coronary event. These findings represent an exciting advance that emphasizes the
value of preventive efforts in curbing CHD.
PMID- 10682163
TI - The management of hypercholesterolemia in patients with coronary artery disease:
guidelines for primary care.
AB - More than 10 million individuals in the United States currently have symptomatic
coronary artery disease (CAD). Asymptomatic CAD is even more prevalent. CAD in
the United States is responsible for approximately 1.5 million myocardial
infarctions, 500,000 deaths, and a total economic burden in excess of $120
billion annually. Fortunately, CAD is preventable in many individuals. Our
understanding of CAD has steadily progressed throughout the 20th century, and now
several lines of evidence support the importance of cholesterol in both the
genesis and management of coronary atherosclerosis. Following identification of
the presence of cholesterol in atheromas, Anitschkov early this century
demonstrated that atherosclerotic lesions can be induced in susceptible animals
by high-saturated-fat and cholesterol diets. These lesions regressed when low-fat
and cholesterol diets were resumed. In the 1970s and 1980s, findings from the
landmark Framingham Heart, Seven Countries, and Multiple Risk Factor Intervention
Trial studies firmly established that hypercholesterolemia was a major risk
factor for cardiovascular morbidity and mortality. During the 1980s and 1990s, 21
of 22 angiographic trials demonstrated reduced progression of coronary and/or
carotid artery disease using lifestyle, drug, and surgical means for reducing
cholesterol. The later trials commonly employed hydroxymethylglutaryl coenzyme A
reductase inhibitors (statins), reflecting increasing clinical use of these
drugs. In 1988, the Adult Treatment Panel of the National Cholesterol Education
Program (NCEP) published guidelines on testing and treating hypercholesterolemic
patients, which outlined a more aggressive approach to cholesterol lowering than
was currently in practice. Since 1994, five large cardiovascular event trials and
a large angiographic trial have shown that aggressive cholesterol lowering
reduces both cardiac morbidity and mortality, largely substantiating the NCEP
guidelines. Although important clinical questions remain regarding patient
subsets and treatment goals, lifestyle changes and appropriate drug therapy have
proved to be highly effective in preventing initial and recurrent cardiovascular
events.
PMID- 10682164
TI - Pathogenesis of asthma.
AB - The conception of the pathogenesis of a disease is probably as important in
determining the selection of therapies as is the evidence provided by outcome
studies of their efficacy. The recent evolution in our understanding of the
pathogenesis of asthma has nicely paralleled advances in clinical research on new
forms of treatment. This evolution has occurred so smoothly that we may not be
fully aware how far it has taken us. Airflow obstruction is still regarded as the
fundamental cause of the characteristic asthmatic symptoms of shortness of
breath, chest tightness, and wheezing, while the factors leading to airflow
obstruction are still assumed to include spasm of airway smooth muscle,
thickening of the airway wall, and inspissation of viscid plugs of mucus in the
airway lumen. What is new is the recognition of asthma as a chronic disease of
the lower airways associated with characteristic inflammatory changes (involving
lymphocytes, mast cells, and eosinophils), and possibly irreversible "remodeling"
of the airways (by deposition of collagen and proteoglycans, proliferation and
transformation of resident cells, and infiltration with inflammatory cells). This
modern conception of asthma differs dramatically from the former perception of
the disease as an episodic illness characterized by disturbance of the
contractile function of airway smooth muscle. The new interpretation has
important implications not just for the development of future therapies based on
the inflammatory mechanisms involved in the pathogenesis of asthma, but also for
the ways in which current therapies should be used.
PMID- 10682165
TI - Diagnosis and periodic assessment of asthma.
AB - This chapter reviews the features of the clinical history that indicate a
diagnosis of asthma, the approach to establishing the diagnosis, and the tests
that may be employed in confirming the diagnosis. Recommendations are provided
for when to refer to an asthma specialist for a consultation or for ongoing care.
The chapter also describes the goal of therapy in asthma and recommends methods
for monitoring asthma, along with specific strategies to improve asthma care and
to enhance communication between the health care provider and the patient. Much
of the content comes directly from the recent Guidelines for the Diagnosis and
Management of Asthma developed by the National Institutes of Health (NIH)-NHLBI
National Asthma Education and Prevention Program (1). Other recent NIH
publications that may provide a valuable resource for the clinician are listed (2
8).
PMID- 10682166
TI - Pharmacologic therapy for asthma.
AB - Pharmacologic therapy is used to prevent and control asthma symptoms, reduce the
frequency and severity of asthma exacerbations, and reverse airflow obstruction.
Recommendations in this chapter, based on the 1997 National Asthma Education and
Prevention Program Expert Panel Report II: Guidelines for the Diagnosis and
Management of Asthma, reflect the scientific concept that asthma is a chronic
disorder with recurrent episodes of airflow limitation, mucus production, and
cough. Asthma medications are categorized into two general classes: long-term
control medications taken daily on a long-term basis to achieve and maintain
control of persistent asthma (these medications are also known as long-term
preventive, controller, or maintenance medications), and quick-relief medications
taken to provide prompt reversal of acute airflow obstruction and relief of
accompanying bronchoconstriction (these drugs are also known as reliever or acute
rescue medications). Patients with persistent asthma require both classes of
medication. Selecting the appropriate pharmacologic therapy to achieve and
maintain control of asthma involves several considerations: the medications and
their routes of administration, a stepwise approach to managing asthma long-term
as a chronic disorder, and the development of an effective clinician-patient
partnership strategy where patient education is continuously provided.
PMID- 10682167
TI - Management of asthma exacerbations.
AB - The 1997 Expert Panel Report 2 from the National Asthma Education and Prevention
Program details principles and goals for managing asthma exacerbations, based on
scientific literature and the opinion of the panel. The panel's recommendations
are summarized here, along with approaches to the evaluation and management of
patients with asthma exacerbations. Methods to assess and classify the severity
of asthma exacerbations are discussed, and treatment objectives for mild,
moderate, and severe exacerbations are presented, along with a discussion of
postinfectious acute airway hyperresponsiveness. A review of pharmacologic agents
used in the treatment of asthma exacerbations is also included. Key points in the
management of asthma exacerbations include the notion that early treatment is the
best strategy for management. Important elements of early treatment include
recognition of early signs of worsening asthma, a written action plan to guide
patient self-management, appropriate intensification of therapy, and prompt
communication between patient and provider about deterioration in asthma control.
Other key points include the use of inhaled beta 2-adrenergic agonists to provide
prompt relief of airflow obstruction, the early use of systemic corticosteroids
for patients with moderate to severe exacerbations or for patients who fail to
respond promptly and completely to an inhaled beta 2-adrenergic agonist, and
monitoring response to therapy with serial measurements of lung function.
PMID- 10682169
TI - New classification and diagnostic criteria for diabetes mellitus.
AB - There has been an explosive growth in knowledge about diabetes mellitus since the
National Diabetes Data Group promulgated diagnostic criteria and a classification
system in 1979 that was largely adopted by the World Health Organization.
However, recent findings regarding the levels of glucose associated with
development of retinopathy, and growing confusion caused by a system of
classification of diabetes based largely on the treatment used have led to a new
assessment of the diagnosis and classification of diabetes mellitus. Using new
data from population-based studies, and placing emphasis on a pathophysiology
based system of classification, in 1997, the Expert Committee of the American
Diabetes Association released its recommendations for the classification and
diagnosis of diabetes. The major changes from the 1979 report include: (a) the
preferred use of the terms "type 1" and "type 2" instead of "insulin-dependent"
and "non-insulin-dependent" to designate the two major types of diabetes
mellitus; (b) a simplification of the diagnostic test to two fasting plasma
glucose (FPG) determinations; and (c) a lower cutoff for FPG (126 mg/dL) to
diagnose diabetes (this level of FPG having been found equivalent to the 200
mg/dL value in the oral glucose tolerance test for diagnosis). These changes
provide an easier and more reliable means of diagnosing persons at risk of
complications of hyperglycemia. Even though the fasting criterion was lowered,
the total number of persons who will be diagnosed with diabetes by exclusive
reliance on FPG will actually be somewhat less than with the old criteria.
Moreover, epidemiologic data support the recommendation that screening for
diabetes should start at age 45 and be repeated every 3 years in persons without
risk factors, and earlier and more often in those with risk factors.
PMID- 10682168
TI - Allergen and irritant control: importance and implementation.
AB - The Expert Panel Report 2. Guidelines for the Diagnosis and Management of Asthma
(1) begins its section on controlling factors that precipitate or worsen asthma
with the statement: "For successful long-term asthma management, it is essential
to identify and reduce exposures to relevant allergens and irritants and to
control other factors that have been shown to increase asthma symptoms and/or
precipitate asthma exacerbations." The presence of allergy to indoor allergens
and certain seasonal fungal spores has been found to be a risk factor for asthma
in epidemiologic studies around the world. Generally between 70% and 85% of
asthmatic populations studied have been reported to have positive skin-prick
tests. Exposure of allergic patients to inhalant allergens increases airway
inflammation, airway hyper-responsiveness, asthma symptoms, need for medication,
severe attacks, and even death due to asthma. Environmental tobacco smoke
exposure has been shown to increase the prevalence of childhood asthma and to
increase asthma symptoms and bronchial hyperresponsiveness while reducing
pulmonary function in children chronically exposed. Exposure to other indoor
irritants, largely products of unvented combustion, has also been found to
increase asthma symptoms. Outdoor air pollution increases asthma symptoms; levels
of specific pollutants correlate with emergency room visits and hospitalization
for asthma. Rhinitis/sinusitis and gastroesophageal reflux are commonly
associated with asthma, and treatment of these conditions has been shown to
improve asthma. In patients sensitive to aspirin and nonsteroidal anti
inflammatory drugs or metabisulfites, exposure to these agents can precipitate
severe attacks of asthma. Viral infections are common causes for exacerbations of
asthma. Infections with Mycoplasma pneumoniae and Chlamydia pneumoniae contribute
to acute exacerbations and perhaps to long-term morbidity, as well. This chapter
will discuss preventive and therapeutic measures that have been found effective
in reducing the impact of aggravating or precipitating factors in patients with
asthma.
PMID- 10682170
TI - Clinical implications of the insulin resistance syndrome.
AB - Insulin resistance syndrome (IRS), also termed syndrome X, is a distinctive
constellation of risk factors for the development of type 2 diabetes mellitus and
cardiovascular disease. The syndrome's hallmarks are glucose intolerance,
hyperinsulinemia, a characteristic dyslipidemia (high triglycerides; low high
density lipoprotein cholesterol, and small, dense low-density lipoprotein
cholesterol), obesity, upper-body fat distribution, hypertension, and increased
prothrombotic and antifibrinolytic factors. Insulin resistance, caused by a
complex of genetic and environmental influences, is now recognized not just as a
mechanism contributing to hyperglycemia in type 2 diabetes, but also as an early
metabolic abnormality that precedes the development of overt diabetes. The
clinical definition of insulin resistance is the impaired ability of insulin
(either endogenous or exogenous) to lower blood glucose. In some insulin
resistant individuals, insulin secretion will begin to deteriorate under chronic
stress (glucose toxicity) and overt diabetes will result. If not, individuals
will remain hyperinsulinemic, with perhaps some degree of glucose intolerance,
together with other hallmarks of the IRS. The statistical correlation between
hypertension and impaired glucose tolerance is clear, although the mechanism is
not yet fully understood. Epidemiologic evidence of insulin resistance as an
independent risk factor for atherosclerosis and coronary heart disease (CHD)
completed the evolving concept of IRS as the common soil for the development of
both diabetes and CHD. No single laboratory test exists for diagnosis of IRS.
Rather, IRS remains a clinically evident syndrome that can be suspected on the
basis of physical and laboratory findings. This identifies individual patients
whom the clinician should screen for associated comorbid conditions, aggressively
control cardiovascular risk factors, and tailor drug therapy for optimal benefit.
This article provides practical guidelines to achieve these goals and specific
strategies to ameliorate cardiovascular and metabolic risk in the IRS.
PMID- 10682171
TI - Glucose control in type 1 diabetes: from conventional to intensive therapy.
AB - The discovery of insulin at the University of Toronto in 1921 and its first
administration on January 11, 1922, dramatically revolutionized the management
and outcome of type 1 diabetes. Type 1 diabetes was transformed from a condition
that was almost uniformly fatal into a chronic disease characterized by the long
term microvascular and macrovascular complications of diabetes. The Diabetes
Control and Complications Trial (DCCT) (1), following the lead of smaller
European studies, demonstrated conclusively that improved glycemic control, as
assessed by glycated hemoglobin (Hb A1c), markedly reduced the development and
progression of retinopathy, neuropathy, and nephropathy. These benefits were
achieved by the implementation of intensive diabetes management regimens (2).
Unfortunately, the advantages of intensive diabetes management were also
accompanied by an increased rate of severe hypoglycemia and weight gain.
Nonetheless, on balance, it is clear that the benefits of intensive therapy far
outweigh the risks. Indeed, the concluding recommendation of the DCCT is that
most patients with type 1 diabetes should be treated with intensive diabetes
management with the goal of achieving the best possible glycemic control. This
article will be divided into four sections providing clinically relevant
information relating to the transferral of patients from conventional to
intensive diabetes management. We will review the principles of intensive
diabetes therapy: selection of patients; implementation of therapy; and
assessment of outcome measures.
PMID- 10682172
TI - Management of glycemia in type 2 diabetes.
AB - The management of type 2 diabetes has been revolutionized over the last 3 to 5
years as a result of dramatic changes in our health care system, new clinical
trial data, novel pharmacologic agents, and a better understanding of appropriate
methods for patient education regarding lifestyle issues. As a result, diabetes
management has become much more heterogeneous, with dramatic differences in style
and approach used by practitioners, whether diabetes specialists, primary care
providers, or allied health professionals. Diabetes care has also become much
more rewarding: The vast majority of patients can now achieve excellent glycemic
control while leading full and unrestricted lives. In this article, a construct
is reviewed by which comprehensive diabetes care may be approached in a primary
care setting. The overall goal of diabetes management should be to provide an
opportunity for patients to live out their normal life expectancies with minimal
complications. In other articles, screening and treatment suggestions for
diabetes complications are provided. Prospective interventional and epidemiologic
studies demonstrate that glycemic control is critical to avoidance of
complications; the methods to achieve glycemic control are the major focus of
this chapter.
PMID- 10682173
TI - Prevention of diabetes complications.
AB - Basic and clinical research findings have led to an increased understanding about
diabetes and its complications. Therapeutic approaches are now based not only on
predicted effects from epidemiologic, correlative, or retrospective analyses, but
often on prospective intervention trials comparing a new form of therapy to the
standard methods. While this database may never be complete, partially due to the
complexity and variability of the diabetic state, we now have excellent data that
allow the development of aggressive new guidelines for care. Much of the material
presented here reflects the views of the American Diabetes Association, as
included in a recent publication (1). These guidelines are under review by a
number of other organizations and will be subject to modification for special
situations. Thus, the terminology "guidelines," rather than "standards of care,"
is chosen to indicate the flexibility necessary in developing such
recommendations for general usage.
PMID- 10682174
TI - Clinical aspects of depression.
AB - In recent years, clinicians and epidemiologists have examined the differences
between depressed patients in primary care and psychiatric settings. Although
evidence to support antidepressant efficacy is largely derived from studies of
major depression, many patients in primary care settings fall into "nonmajor"
depression diagnostic categories. In deciding when to initiate treatment,
functional change may be even more important than discrete symptom profiles.
Recognizing and treating depression as a comorbid condition in patients with
other medical illnesses represents an additional challenge for the primary care
physician. Variations in the clinical presentation of depression based on gender,
age, culture, or personality must also be considered.
PMID- 10682175
TI - Basic neuropharmacology of antidepressants relevant to the pharmacotherapy of
depression.
AB - In the past decade, 8 new antidepressants were approved for use in the United
States by the US Food and Drug Administration. Six of these have been marketed in
the United States since 1992. Two additional drugs marketed outside the United
States as antidepressants have been approved in this country for obsessive
compulsive disorder. Together with the conventional antidepressants, the new
ones, and the 2 drugs available off-label, the physician can choose from a list
of 22 compounds to treat the depressed patient. This article reviews theories
about the mechanisms of action of antidepressants and the basic pharmacology of
the newer-generation drugs in relation to the older compounds. We hope this
information is of use to the clinician in treating acute depression with
pharmacologic agents.
PMID- 10682176
TI - Antidepressant options in primary care.
AB - This article summarizes the basic and clinical pharmacology of the available
antidepressants to aid the busy primary care practitioner in anticipating and
predicting the effects of different antidepressants on patients; choosing a
specific antidepressant for each patient based on these effects; selecting a
sequential antidepressant for the patient who has not benefited from a trial of a
specific type of antidepressant, either because of inadequate effect or treatment
limiting adverse effects; and avoiding adverse drug interactions when choosing an
antidepressant for patients on other drug therapy.
PMID- 10682177
TI - Strategies for treatment-resistant depression.
AB - Clinical depression is a common disorder with serious implications that is often
misdiagnosed or underestimated. More than 50% of suicides are associated with a
major depressive disorder, and depression can adversely impact a variety of other
medical conditions. Although > or = 70% of depressions can respond to appropriate
medications, few patients actually receive adequate medical therapy. This article
reviews the definition of adequate therapy for depression, discusses common
comorbid conditions, and examines the issue of true treatment resistance.
Practical strategies for treatment-resistant depression, including switching
classes of antidepressant drugs, combination therapy, augmentation strategies,
and somatic therapies, are incorporated into a treatment algorithm.
PMID- 10682178
TI - Gastroesophageal reflux: practical management of a common, challenging disorder.
AB - Gastroesophageal reflux (GER) occurs in 2 distinct forms that differ in
pathophysiology, clinical presentation, natural history, and therapy: mild GER
(with no or minimal esophagitis) and classic, severe reflux (at risk for erosive
esophagitis). A minority of subjects (< 20%) have the classic, potentially severe
pattern of GER caused by reduced lower esophageal sphincter (LES) pressure and
prolonged acid reflux, particularly at night, but also during the day. Evaluation
and management must be catered to patients with this pattern of reflux. In
contrast, symptoms in mild reflux (the majority) often occur during the day after
meals in an upright posture (upright reflux); resting LES pressure is usually
normal (reflux episodes are related to transient relaxation of the LES) and
little reflux occurs at night. Acid reflux, which occurs mostly during the day,
overlaps with the normal range and esophagitis is rare; however, symptoms can be
distressing. Optimal management is controversial because no outcome trials have
been conducted to address management in primary care settings. However, clinical
clues can help differentiate mild and severe reflux and guide management
decisions. This article provides a detailed approach to current management of GER
syndromes.
PMID- 10682179
TI - Diagnosis and management of Helicobacter pylori infection.
AB - Helicobacter pylori infects more than half of the world's population, making it
one of the most prevalent infections. H pylori is now accepted as the most common
cause of histologic gastritis and is responsible for the majority of cases of
peptic ulcer disease and gastric cancer. Approximately 1 in 6 (17%) persons with
H pylori infection will develop peptic ulcer disease, and each year 1% to 2% of
these will experience a major or life-threatening complication, such as bleeding,
perforation, or gastric outlet obstruction. Peptic ulcer disease should no longer
be regarded as a chronic, recurring, lifelong disease, but rather as a curable
infectious disease. The diagnosis and therapy of this common infectious disorder
have become increasingly straightforward. In this article, we discuss the
possible outcomes of long-standing infection, the various diagnostic tests
available, including whom and when to test, and the combination drug regimens
approved for cure.
PMID- 10682180
TI - Peptic ulcer and dyspepsia.
AB - Peptic ulcers are defects in the gastrointestinal mucosa that extend through the
muscularis mucosae. They persist as a function of the acid or peptic activity in
gastric juice. Twenty years ago, most ulcers were considered idiopathic; but a
revolution in knowledge has occurred, so that it is now understood that the great
majority of ulcers results from infection with Helicobacter pylori (HP) or use of
nonsteroidal anti-inflammatory drugs (NSAIDs). Before this revolution, peptic
ulcer disease was a common public health problem, responsible for considerable
morbidity, some mortality, and high economic cost. Today, the overall prevalence
of ulcers is falling, but complication rates remain relatively stable. These
complex trends primarily reflect 3 factors: the rapid decline in the prevalence
of HP in the population of developed countries, an increase in consumption of
NSAIDs, and change in rates of smoking. Peptic ulcer prevalence is falling in
younger individuals because of decreased prevalence of HP, whereas complications
are rising in older subjects, largely as the result of increased NSAID use.
PMID- 10682181
TI - NSAID-related gastrointestinal complications.
AB - Despite the common induction of gastrointestinal (GI) complications by
nonsteroidal anti-inflammatory drugs (NSAIDs), many aspects of pathogenesis and
management remain controversial. The most important complications are bleeding
and perforation arising in the esophagus, stomach, and duodenum due to NSAID
effects on platelets and on a variety of mucosal lesions. Complications arise
from preexisting peptic ulcer, NSAID-induced ulcers and erosions, and other
lesions (not caused by NSAIDs) caused to bleed by NSAID-induced platelet
dysfunction. Much confusion has arisen from the umbrella term "NSAID gastropathy"
used to embrace a variety of pathogenetically distinct mucosal lesions. Failure
to discriminate among the different forms of NSAID injury has hampered clinical
investigation. This article offers general guidelines for prevention of NSAID
complications, but there remain many unresolved issues, including the role of
Helicobacter pylori infection. The best approach to management is to remove or
reduce exposure to NSAIDs whenever possible. The newer NSAIDs (e.g., cyclo
oxygenase [COX]-2-selective inhibitors) have a much lower risk of endoscopic
ulcers and minimal platelet effects, which are likely to translate into lower
risk of GI complications. However, this benefit on clinical outcome remains to be
established.
PMID- 10682182
TI - Common functional gastrointestinal disorders: nonulcer dyspepsia and irritable
bowel syndrome.
AB - Up to 35% of the world population suffer from functional gastrointestinal
disorders (FGD), accounting for about 40% of gastroenterologic and 12% of primary
care practice. Society incurs high costs from FGD morbidity in terms of medical
workups and absenteeism from work. FGD are characterized by chronic and recurrent
symptoms of the gastrointestinal (GI) tract without detectable structural or
biochemical abnormalities. In the absence of universal biologic markers, the
diagnosis is based on consensus symptom criteria (1). This chapter reviews
current knowledge of the pathophysiology and provides a practical approach to
patients with functional dyspepsia and irritable bowel syndrome, 2 of the most
common functional GI syndromes.
PMID- 10682183
TI - Classification and epidemiology of headache.
AB - Headache disorders are remarkably common. Like back pain, headache is a symptom
that has a broad range of possible causes. Diagnosis of primary headache
disorders (migraine, tension-type headache, cluster headache) depends on
systematic exclusion of secondary disorders and systematic identification of the
specific features of the primary disorders. Thus, migraine should be viewed as an
episodic syndrome of pain, involving intracranial structures associated with
other neurologic disturbances. Because of the large number of potential
etiologies, clinicians must approach headache classification systematically. In
this chapter, we provide an overview of headache classification followed by
discussions of epidemiology.
PMID- 10682185
TI - Diagnosis and treatment of migraine.
AB - Migraine is one of the most common and misunderstood disease encountered in
general medical practice. An estimated 23 million Americans suffer disabling
migraines, yet only a minority are diagnosed (1,2). An even smaller percentage
receive optimal care. Migraine extracts a significant personal, psychologic,
social, and economic toll from migraineurs and their families. An estimated 150
million workdays are lost annually due to headache at an estimated cost of $6 to
$17 billion (3,4). Recent advances in understanding of the pathophysiology and
acute therapy provide the potential to markedly reduce the impact of migraine.
Available abortive medications have efficacy rates as high as 80%, but only a
minority of afflicted patients currently receive these therapies. While reducing
headache pain, they also restore function, enabling an individual to return to
work, family, and personal commitments (5). Future progress in migraine
management resides in early identification and optimization of migraine
treatment. This article focuses on diagnosis and treatment.
PMID- 10682184
TI - Headache diagnosis.
AB - Headache is an extremely common symptom in primary care practice. Despite the
ubiquity of the pain, differential diagnosis of headache is not difficult,
provided the clinician obtains a comprehensive history. A complete physical
examination and specific testing may be required to rule out other underlying
causes, but headache itself falls into 3 main classes that are readily
identified. Migraine headache occurs most commonly in women, is of moderate to
severe intensity, and is often accompanied by nausea and increased sensitivity to
light and sound. Cluster headache describes multiple recurrent attacks of severe
unilateral pain and occurs most frequently in men. Tension-type headache is the
most common form, characterized by mild to moderate dull pain that is often
brought on by stress and/or depression. Understanding the triggers and
manifestations of these headache types is essential for effective management.
PMID- 10682186
TI - Tension-type headache.
AB - Tension-type headaches, the most prevalent form of headache, are differentiated
as being either episodic or chronic. The episodic form is a physiologic response
to stress, anxiety, depression, emotional conflicts, fatigue, or repressed
hostility. Treatment focuses on the use of over-the-counter or prescribed simple
analgesics for pain relief. Successful treatment of the chronic form depends on
recognition of depression or persistent anxiety states. Primary care physicians
can effectively manage most of these patients with nonhabituating anxiolytic or
antidepressant medications; however, referrals for psychotherapy may be required
in some cases. When tension-type headaches occur in children and adolescents, the
physician must explore the patient's family and social relationships as well as
school performance. In addition to nonhabituating drug therapies, family
counseling and biofeedback may be helpful. In coexisting migraine and tension
type headaches, nonhabituating analgesics may be used for the relief of acute
pain; the use of ergotamine and triptans should be restricted to relief of the
hard or sick headache. Tricyclic antidepressants or monoamine oxidase inhibitors
are the gold standards for prophylaxis, although the selective serotonin reuptake
inhibitors may be indicated in less severe cases. Several forms of biofeedback
have also proved effective. Nonetheless, some patients with this form of headache
may require psychiatric treatment for severe depression.
PMID- 10682187
TI - Emergency department management of the acute headache.
AB - Headache is a common complaint of patients seeking care at an emergency
department (ED). A survey of more than 16,755 walk-in patients at an ED showed
that 323 (1.9%) had a chief complaint of migraine (1). Almost one sixth of these
patients had used the ED more than once. In fact, migraineurs used the ED and
other health care providers 2 to 5 times more than nonmigraineurs (2).
Fortunately, headaches associated with significant morbidity and mortality occur
infrequently (3). The ED physician must be able to address the patient's need for
pain management and establish the correct diagnosis for the headache while also
ruling out any possibility of organic disease or life-threatening illness.
Potential problems include ensuring appropriate follow-up and avoidance of
narcotic habituation.
PMID- 10682189
TI - Moderate alcohol intake protective effect
PMID- 10682188
TI - Reduced mortality with moderate alcohol intake
PMID- 10682190
TI - Broader use of lipid-lowering therapy argued.
PMID- 10682191
TI - The diabetic patient as paradigm for selective antihypertensive therapy.
AB - General recommendations from US and international organizations indicate that an
ideal approach to the therapy of hypertension should begin with lifestyle
modifications, such as decreased salt and fat intake and a careful aerobic
exercise program, with the therapeutic goal of a blood pressure (BP) < 140/90 mm
Hg. The most recent guidelines recommend more rigorous targets for BP lowering in
high-risk populations, such as those with hypertension and concomitant diabetes
and/or renal disease with proteinuria. This chapter addresses hypertension in
patients with diabetes as an example of a group at especially high risk. It
reviews recent clinical trials that support more rigorous BP goals in such
patients to reduce cardiovascular morbidity and mortality and considers the
importance of combination therapy in achieving these goals.
PMID- 10682192
TI - Does the evidence from clinical trials justify the treatment of hypertension?
AB - Hypertension is the most common reason for physician office visits. An estimated
43 to 50 million people in the United States have elevated blood pressure (BP).
The prevalence of hypertension varies from a small percentage among individuals
in their teens and 20s to more than 70% of the elderly (those > 75 years of age).
The US Public Health Services (USPHS) has set a goal of having 50% of individuals
with hypertension "under control"--that is, reducing their BP to < 140 mm Hg
systolic and < 90 mm Hg diastolic--by the year 2000. Current information suggests
that we will fall far short of reaching that goal. In the early 1990s, such
levels had been achieved by only 27% of hypertensive Americans 18 to 74 years old
and by only 20% of those > 75 years old. Is this a cause for concern? Is the goal
defined by the USPHS justified? Should we push even harder to reach that goal,
should we strive to do even better, or should we be satisfied? Since we are now
in the era of evidence-based medicine, the only way to answer these questions is
to review what we have learned from the many large, prospective, well-controlled,
long-term clinical trials that have addressed these questions over the past 3
decades.
PMID- 10682193
TI - Diagnosis and evaluation of secondary hypertension.
AB - Although patients with secondary hypertension comprise only a small percentage of
those with elevated blood pressure, this subgroup should not be ignored. In many
cases, correcting the cause of secondary hypertension can lead to a cure, thus
avoiding the need for long-term medical therapy, with its attendant risks and
economic toll. Moreover, effective treatment of secondary hypertension can
prevent chronic complications, such as left ventricular hypertrophy and coronary
artery disease, which markedly increase morbidity and mortality. Nearly all forms
of secondary hypertension are related to decreased renal function and/or
derangement of hormonal balance or secretion. If hypertension is secondary to
chronic renal failure of any etiology, it can be recognized from biochemical
assays for blood urea nitrogen and creatinine.
PMID- 10682194
TI - Diagnosis and management of hypertensive emergencies.
AB - It has been estimated that approximately 600,000 to 800,000 Americans will
develop a hypertensive crisis (Calhoun and Oparil, 1990). Although such numbers
represent only about 1% of the estimated 60 million Americans with hypertension,
hypertensive crisis often constitutes a major medical emergency, necessitating a
focused, assertive, and reasoned therapeutic intervention. When such patients are
seen in the emergency department or in a physician's office with a critical
elevation in blood pressure (BP), appropriate and efficacious management is
essential to avoid catastrophic injury to vital target organs, including the
central nervous system, the heart, and the kidneys. Delays in initiating
effective therapy or, equally important, overzealous therapy leading to a too
rapid reduction in BP can produce severe complications involving these target
organs. This article reviews the spectrum of clinical syndromes that comprise
hypertensive emergencies, highlighting 2 to illustrate the complexities of
clinical presentation and management. The newly advocated treatment guidelines
based on the category of acute severe hypertension (including asymptomatic
hypertensive urgencies) are also considered, as are therapeutic strategies
utilizing currently available antihypertensive agents.
PMID- 10682195
TI - Broadening behavioral decision research: multiple levels of cognitive processing.
AB - The area of behavioral decision research--specifically, the work on heuristics
and biases--has had a tremendous influence on basic research, applied research,
and application over the last 25 years. Its unique juxtaposition against
economics has provided important benefits, but at the cost of leaving it
disconnected from too much of psychology. This paper explores an expanded
definition of behavioral decision research through the consideration of multiple
levels of cognitive processing. Rather than being limited to how decision makers
depart from optimality, we offer a broader analysis of how decision makers define
the decision problem and link decisions to goals, as well as a more detailed
focus on processes associated with implementing decisions.
PMID- 10682196
TI - Changing plans: dynamic inconsistency and the effect of experience on the
reference point.
AB - This article presents a new test of a principle of decision making called dynamic
consistency. This principle was tested in an experiment in which participants
were asked to make decisions about a second gamble within a sequence of two
gambles. Participants were first asked to make a planned choice about the second
gamble. The planned choice was made before the first gamble was played and was
conditioned on the anticipated outcomes of the first gamble. After the first
gamble was played, the same participants were asked to make a final choice about
the second gamble, conditioned on the experienced outcome of the first gamble.
The results showed that participants' final choices were frequently inconsistent
with their plans, even when the anticipated and experienced outcomes were
identical. These inconsistencies occurred in a systematic direction. Experiencing
an anticipated gain resulted with a change toward risk aversion, and experiencing
an anticipated loss resulted in a change toward risk seeking. These results are
explained in terms of the effect of actual experience on the reference point used
for the evaluation of the decision problem.
PMID- 10682197
TI - Value seeking and prediction-decision inconsistency: why don't people take what
they predict they'll like the most?
AB - In this research, it is proposed that, when making a choice between consumption
goods, people do not just think about which option will deliver the highest
consumption utility but also think about which choice is most consistent with
rationales--beliefs about how they should make decisions. The present article
examines a specific rationale, value seeking. The value-seeking rationale refers
to the belief that one should choose the option in a choice set that has the
highest monetary value. Studies 1 and 2 show that value seeking could lead to a
prediction-decision inconsistency, predicting a high consumption utility from one
option but choosing another option. Study 3 shows that the prediction-decision
inconsistency could be created even by "illusory" (as opposed to truly monetary)
values and that the inconsistency could be turned on or off through empirical
manipulation.
PMID- 10682198
TI - The semantic side of decision making.
AB - The research reported in this paper follows the perspective that decision making
is a meaningful act that conveys information. Furthermore, the potential meanings
associated with decision options may affect the decisions themselves. This idea
is examined in the contexts of compensation, donation, and exchange. In general,
judgments were relation dependent and meaning dependent. Furthermore, the results
show nonmonotonicities and limited substitutability in a pattern that challenges
straightforward ways of mapping decisions onto a common currency of utility.
PMID- 10682199
TI - Counterfactual thinking and decision making.
AB - Recent research on counterfactual thinking is discussed in terms of its
implications for decision making. Against a backdrop of the functional benefits
of counterfactual thinking, two distinct types of bias, one liberal and one
conservative, are discussed. Counterfactuals may cause decision makers to become
liberally biased (i.e., capricious) in terms of tactics, but conservatively
biased (i.e., rigid) in terms of long-term strategy. That is, counterfactuals may
lead to short-term corrective changes that are needless and costly, but they may
also lead to long-term overconfidence, blinding the decision maker to possible
beneficial strategic adjustments. Recent research on counterfactual thinking,
which is inherently multidisciplinary, is reviewed in light of a theoretical
structure that posits two mechanisms by which counterfactual effects occur:
contrast effects and causal inferences.
PMID- 10682200
TI - Choosing remedies after accidents: counterfactual thoughts and the focus on
fixing "human error".
AB - The present research is motivated by an interest in why organizational decision
makers so often respond to accidents with remedy plans that focus narrowly on
correcting human error rather than more environment-focused plans or more
encompassing plans. We investigated the role of counterfactual thinking in the
decision-making tendency toward human-focused plans. Our experiments indicated
that even in a domain where human-focused remedies were not otherwise appealing,
many participants decided on human-focused remedies after they had generated an
"if only" conjecture about the accident. This reflects that human actions are
often selected as the focus of "if only" conjectures and, importantly, that this
focus "locks in" and carries through to subsequent remedy decisions. Our
hypothesis that remedy plans are produced from "if only" thoughts was supported
over several alternative interpretations. We discuss implications for research on
the relation between counterfactual thinking and adaptive learning.
PMID- 10682201
TI - Analogical encoding facilitates knowledge transfer in negotiation.
AB - Information learned in one situation often fails to transfer to a similarly
structured situation. However, prior findings suggest that comparing two or more
instances that embody the same principle can promote abstraction of a schema that
can be transferred to new situations. In two lines of research, we examined the
effects of analogical encoding on knowledge transfer in negotiation situations.
In Experiment 1, undergraduates were more likely to propose optimal negotiation
strategies and less likely to propose compromises (a suboptimal strategy) when
they received analogy training. In Experiment 2, graduate management students who
drew an analogy from two cases were nearly three times more likely to incorporate
the strategy from the training cases into their negotiations than were students
given the same cases separately. For both novices and experienced participants,
the comparison process can be an efficient means of abstracting principles for
later application.
PMID- 10682202
TI - Why some are perceived as more confident and more insecure, more reckless and
more cautious, more trusting and more suspicious, than others: enriched and
impoverished options in social judgment.
AB - In line with the principle of compatibility, when making social judgments, people
tend to focus on personality attributes compatible with the trait under
consideration. Better known, or enriched, personages are more likely to present
attributes that are compatible with a particular trait than are personages about
whom little is known. As a result, enriched personages are more likely to have
various, sometimes even conflicting, traits attributed to them. This hypothesis
is supported by a number of studies that compare the frequency with which some
people are chosen as being better described by opposite trait adjectives than are
others. Celebrities more often have both of a pair of opposing adjectives
ascribed to them than do less well known figures. Similarly, subjects judge
themselves to be better described by either of a pair of opposite adjectives than
is a person who is relatively unknown in their lives. The implications for social
judgment and for everyday decisions are discussed.
PMID- 10682203
TI - Models and mosaics: investigating cross-cultural differences in risk perception
and risk preference.
AB - In this article, we describe a multistudy project designed to explain observed
cross-national differences in risk taking between respondents from the People's
Republic of China and the United States. Using this example, we develop the
following recommendations for cross-cultural investigations. First, like all
psychological research, cross-cultural studies should be model based.
Investigators should commit themselves to a model of the behavior under study
that explicitly specifies possible causal constructs or variables hypothesized to
influence the behavior, as well as the relationship between those variables, and
allows for individual, group, or cultural differences in the value of these
variables or in the relationship between them. This moves the focus from a simple
demonstration of cross-national differences toward a prediction of the behavior,
including its cross-national variation. Ideally, the causal construct
hypothesized and shown to differ between cultures should be demonstrated to serve
as a moderator or a mediator between culture and observed behavioral differences.
Second, investigators should look for converging evidence for hypothesized
cultural effects on behavior by looking at multiple dependent variables and using
multiple methodological approaches. Thus, the data collection that will allow for
the establishment of conclusive causal connections between a cultural variable
and some target behavior can be compared with the creation of a mosaic.
PMID- 10682204
TI - Associative competition in operant conditioning: blocking the response-reinforcer
association.
AB - Naive rats were trained to leverpress with a 30-sec delay-of-reinforcement
contingency from the start of training. In Experiment 1, the delay interval for
different groups of subjects included a signal in the first 5 sec, a signal in
the last 5 sec, or no signal at any time. Rats with the signal at the start of
the delay interval learned most rapidly. Rats with the signal at the end of the
delay failed to learn. In Experiment 2, a choice procedure was used, in which
each of two levers was associated with its own 30-sec delay of reinforcement. The
delay for one lever included a 5-sec signal at the end of the delay. The delay
for the second lever had no signal in its 30-sec delay. Preference was in favor
of the lever without the signal in the delay interval. The results demonstrate
that the acquisition of new response can be blocked in a manner analogous to the
blocking of Pavlovian conditioning.
PMID- 10682205
TI - The time course of phonological, semantic, and orthographic coding in reading:
evidence from the fast-priming technique.
AB - The present experiment employed the fast-priming paradigm in reading (Sereno &
Rayner, 1992), in which sentences are silently read while eye-movement-contingent
changes are made on a specified target region. In this paradigm, when readers
fixate on a specified target word region, a prime word is encountered for a brief
duration at the beginning of the fixation and then it is replaced by a target
word. Three types of primes were employed: homophones, semantically related, and
orthographically similar, and five prime durations were employed: 29, 32, 35, 38,
and 41 msec. The primary finding was that significant homophone priming was
obtained at prime durations ranging from 29 to 35 msec, whereas significant
semantic priming occurred only at the 32-msec prime duration. In contrast,
significant orthographic priming occurred at all prime durations. These findings
indicate that phonological codes are activated during an eye fixation at least as
rapidly as semantic codes. An explanation for the pattern of events is suggested
using the framework of an activation-verification model.
PMID- 10682206
TI - Syntactic priming in written production: evidence for rapid decay.
AB - There is strong evidence for syntactic priming in language production (Bock,
1986), but little evidence about the time course of such effects. We report an
experiment that examined the circumstances under which syntactic priming decays
in written language production. Participants completed sentence fragments that
allowed completions with one of two syntactic forms (Pickering & Branigan, 1998).
They tended to produce the same syntactic form for immediately consecutive
fragments, even though the two fragments described different events. However,
when the experimental fragments were separated by other fragments with unrelated
syntactic forms, this tendency rapidly diminished. The results suggest that
priming effects in written production decay rapidly when other structures are
subsequently produced. We discuss the implications for the application of
syntactic information during production.
PMID- 10682207
TI - Name that tune: identifying popular recordings from brief excerpts.
AB - We tested listeners' ability to identify brief excerpts from popular recordings.
Listeners were required to match 200- or 100-msec excerpts with the song titles
and artists. Performance was well above chance levels for 200-msec excerpts and
poorer but still better than chance for 100-msec excerpts. Performance fell to
chance levels when dynamic (time-varying) information was disrupted by playing
the 100-msec excerpts backward and when high-frequency information was omitted
from the 100-msec excerpts; performance was unaffected by the removal of low
frequency information. In sum, successful identification required the presence of
dynamic, high-frequency spectral information.
PMID- 10682208
TI - Figural aftereffects in the perception of faces.
AB - We examined figural aftereffects in images of human faces, for which changes in
configuration are highly discriminable. Observers either matched or rated faces
before or after viewing distorted images of faces. Prior adaptation strongly
biases face perception by causing the original face to appear distorted in a
direction opposite to the adapting distortion. Aftereffects transferred across
different faces and were similar for upright or inverted faces, but were weaker
when the adapting and test faces had different orientations (e.g., adapt inverted
and test upright). Thus the aftereffects depend on which images are distorted,
and not simply on the type of distortion introduced. We further show that the
aftereffects are asymmetric, for adapting to the original face has little effect
on the perception of a distorted face. This asymmetry suggests that adaptation
may play an important normalizing role in face perception. Our results suggest
that in normal viewing, figural aftereffects may strongly influence form
perception and could provide a novel method for probing properties of human face
perception.
PMID- 10682209
TI - Recognition memory for faces: when familiarity supports associative recognition
judgments.
AB - Recognition memory for single items can be dissociated from recognition memory
for the associations between items. For example, recognition tests for single
words produce curvilinear receiver operating characteristics (ROCs), but
associative recognition tests for word pairs produce linear ROCs. These
dissociations are consistent with dual-process theories of recognition and
suggest that associative recognition relies on recollection but that item
recognition relies on a combination of recollection and assessments of
familiarity. In the present study, we examined associative recognition ROCs for
facial stimuli by manipulating the central and external features, in order to
determine whether linear ROCs would be observed for stimuli other than arbitrary
word pairs. When the faces were presented upright, familiarity estimates were
significantly above zero, and the associative ROCs were curvilinear, suggesting
that familiarity contributed to associative judgments. However, presenting the
faces upside down effectively eliminated the contribution of familiarity to
associative recognition, and the ROCs were linear. The results suggest that
familiarity can support associative recognition judgments, if the associated
components are encoded as a coherent gestalt, as in upright faces.
PMID- 10682210
TI - The importance of monitoring and self-regulation during multitrial learning.
AB - Theory suggests that accuracy of metacognitive monitoring and self-regulation of
study will affect test performance, but there is little empirical evidence
linking these variables. I examined the relation among these variables in a
multitrial learning task. Regression analyses showed that monitoring accuracy and
self-regulation were reliably related to test performance--greater monitoring
accuracy and more effective self-regulation were associated with greater test
performance. These analyses were contrasted with analyses typically conducted in
previous research, to show the importance of using a multitrial learning task and
of attending to the theoretically based causal relation among variables when
evaluating how monitoring accuracy and self-regulation are related to test
performance. The results of this investigation may help to explain why previous
research has failed to link these variables.
PMID- 10682211
TI - Aptness predicts preference for metaphors or similes, as well as recall bias.
AB - Why might we sometimes prefer a metaphor such as "genes are blueprints" to a
simile such as "genes are like blueprints"? One possibility is that metaphors are
preferred when the comparison between a tenor (e.g., genes) and a vehicle (e.g.,
blueprints) seems especially apt. That is, metaphors might be used when the
comparison captures many salient features of the tenor in question. The present
experiments examined the relation between the aptness of comparisons and people's
preferences for expressing those comparisons as metaphors or as similes. In
Experiment 1, it was found that there is consensus on how to express particular
comparisons. In Experiment 2, it was found that this preference can be predicted
from the aptness of a comparison. It was also found that aptness can predict
errors in the recall of comparisons. These findings have implications for
theories of metaphor.
PMID- 10682212
TI - Predicting conjunction typicalities by component typicalities.
AB - In two studies, we investigated to what extent typicalities in conjunctive
concepts phrased as relative clauses--such as pets that are also birds--can be
predicted from simple functions of constituent typicalities and from extensions
of such functions. In a first study, analyses of a large aggregated data set,
based on seven different experiments, showed that a calibrated minimum rule model
and some extensions of this model accounted for a very large part of the variance
in the conjunction typicalities. The same models can also account for the so
called guppy effect. A psychological explanation is presented, which states that
typicalities in contrast categories, like pets that are not birds and birds that
are not pets, further improve the prediction of conjunction typicalities. This
hypothesis is tested in a second study.
PMID- 10682213
TI - Neuroimaging research and the neurobiology of obsessive-compulsive disorder:
where do we go from here?
PMID- 10682214
TI - Genetics and etiology of schizophrenia and bipolar disorder.
PMID- 10682215
TI - Proton spectroscopic imaging of the thalamus in treatment-naive pediatric
obsessive-compulsive disorder.
AB - BACKGROUND: Neurobiological abnormalities in the thalamus, particularly the
dorsomedial nucleus of the thalamus, are believed to be involved in the
pathophysiology of obsessive-compulsive disorder. Although obsessive-compulsive
disorder commonly arises in childhood and adolescence, no prior study has
examined the thalamus in pediatric obsessive-compulsive disorder patients.
METHODS: In this study, N-acetyl-aspartate, a putative marker of neuronal
viability, creatine/phosphocreatine, and choline levels were measured in the
lateral and medical subregions of the left and right thalami using a multislice
proton magnetic resonance spectroscopic imaging sequence in 11 treatment-naive,
nondepressed obsessive-compulsive disorder outpatients, 8-15 years old, and 11
case-matched control subjects. RESULTS: A significant reduction in N-acetyl
aspartate/choline and N-acetyl-aspartate/(creatine/phosphocreatine + choline) was
observed in both the right and left medial thalami in obsessive-compulsive
disorder patients compared with control subjects. The N-acetyl-aspartate/choline
and N-acetyl-aspartate/(creatine/phosphocreatine + choline) levels did not differ
significantly between case-control pairs in either the left or the right lateral
thalamus. Reduction in N-acetyl-aspartate levels in the left medial thalamus was
inversely correlated with increased obsessive-compulsive disorder symptom
severity. CONCLUSIONS: These findings provide new evidence of localized
functional neurochemical marker abnormalities in the thalamus in pediatric
obsessive-compulsive disorder. Our results must be considered preliminary,
however, given the small sample size.
PMID- 10682216
TI - Molecular genetics of Alzheimer's disease.
AB - Application of genetic paradigms to Alzheimer's disease (AD) has led to
confirmation that genetic factors play a role in this disease. Additionally,
researchers now understand that AD is genetically heterogeneous and that some
genetic isoforms appear to have similar or related biochemical consequences.
Genetic epidemiologic studies indicate that first-degree relatives of AD probands
have an age-dependent risk for AD approximately equal to 38% by age 90 years
(range 10% to 50%). This incidence strongly suggests that transmission may be
more complicated than a simple autosomal dominant trait. Nevertheless, a small
proportion of AD cases with unequivocal autosomal dominant transmission have been
identified. Studies of these autosomal dominant familial AD (FAD) pedigrees have
thus far identified four distinct FAD genes. The beta-amyloid precursor protein
(beta APP) gene (on chromosome 21), the presenilin 1 (PS1) gene (on chromosome
14), and the presenilin 2 (PS2) gene (on chromosome 1) gene are all associated
with early-onset AD. Missense mutations in these genes cause abnormal beta APP
processing with resultant overproduction of A beta 42 peptides. In addition, the
epsilon 4 allele of apolipoprotein E (APOE) is associated with a increased risk
for late-onset AD. Although attempts to develop symptomatic treatments based on
neurotransmitter replacement continue, some laboratories are attempting to design
treatments that will modulate production or disposition of A beta peptides.
PMID- 10682217
TI - Molecular and cellular mechanisms of cognitive function: implications for
psychiatric disorders.
AB - Recent studies on the molecular and cellular basis of learning and memory have
brought us closer than ever to understanding the mechanisms of synaptic
plasticity and their relevance to memory formation. Genetic approaches have
played a central role in these new findings because the same mutant mice can be
studied with molecular, cellular, circuit, and behavioral tools. Therefore, the
results can be used to construct models that cut across levels of analytical
complexity, forging connections from the biochemistry of the modified protein to
the behavior of the mutant mice. These findings are not only improving our
understanding of learning and memory, they are also enriching our understanding
of cognitive disorders, such as neurofibromatosis type I. Mechanisms underlying
long-term changes in synaptic function are likely to be at the heart of many
cognitive and emotional processes in humans. Therefore, molecular and cellular
insights into learning and memory undoubtedly will have a profound impact on the
understanding and treatment of psychiatric disorders.
PMID- 10682218
TI - Schizophrenia: genes and environment.
AB - The historical and genetic foundations of our current understanding of
schizophrenia are reviewed, as are the present and future directions for
research. Genetic epidemiological investigations, including family, twin, and
adoption studies have confirmed the contributions of genetic and environmental
determinants of schizophrenia. For example, identical twins show average
concordance rates of only 50%; rates of 100% would be expected on the basis of
genetic equivalence alone. Genetic factors may cause errors in brain development
and synaptic connections. A broad range of environmental components may further
damage the brain. Biological components may include pregnancy and delivery
complications, such as intrauterine fetal hypoxia, infections, and malnutrition.
Primarily nonbiological components may include psychosocial stressors, such as
residence in an urban area and dysfunctional family communication. It is likely
that the environmental factors interact with the genetic liability in a negative
manner to produce disorders in the schizophrenic spectrum. Genetic and
environmental components of the disorder are examined, as well as their
interactions in producing either neurodevelopmental syndromes or schizophrenia
itself. The implication of these findings for prevention and treatment are
considered.
PMID- 10682219
TI - Search for schizophrenia susceptibility genes.
AB - Identification of a gene or genes that contribute to the development of
schizophrenia, a complex psychiatric disorder, may be possible through genetic
linkage analysis. Although to date no single causative gene has been identified,
several chromosomal loci have shown positive linkage results and are under
investigation as tentative schizophrenia susceptibility loci. Despite such
obstacles as locus heterogeneity among sample populations, epistatic inheritance
models, and failure to obtain statistical significance in studies, patterns have
emerged that focus research efforts on chromosomes 13, 8, 22, and 6 and 10.
Initial heterogeneity analyses suggests that identifiable subgroups of the
families may not contribute equally to these linkage findings. Findings on
several additional chromosomes await further replication. Future progress in the
search for schizophrenia susceptibility genes will require collaboration among
researchers from both academia and industry.
PMID- 10682220
TI - Familial transmission of risk factors in the first-degree relatives of
schizophrenic people.
AB - Schizophrenia is a complex illness with multiple pathophysiologic factors that
contribute to its psychopathology. One strategy to identify these factors is to
observe them in isolation from each other, by characterizing their expression in
the relatives of schizophrenic probands. By Mendel's second law, each genetic
factor should be independently distributed in a sibship, so that each can be
observed by itself, uncomplicated by the general problems of the illness. Such
independently distributed phenotypes are obviously useful for genetic analyses;
however, they can also be considered together, to model how various brain
dysfunctions may combine to produce psychoses. In addition to a sensory gating
deficit linked to the alpha 7-nicotinic acetylcholine receptor locus,
schizophrenics and their families have a number of other deficits, including
decreased hippocampal volume on magnetic resonance images and increased plasma
levels of the dopamine metabolite homovanillic acid. Although such research is
far from complete, a heuristic model combining a sensory gating deficit,
decreased hippocampal neuron capacity, and increased dopaminergic
neurotransmission is consonant with current understanding of the neuropsychology
of schizophrenia.
PMID- 10682221
TI - Bipolar illness and schizophrenia as oligogenic diseases: implications for the
future.
AB - As with most complex inheritance diseases, there are at this time no identified
susceptibility genes for schizophrenia, bipolar manic-depressive illness, major
depression, childhood autism, and other inherited brain disorders whose
manifestations are primarily behavioral. Nonetheless, progress has occurred.
Genetic epidemiologic research, based on reliable phenotypic definitions, has
demonstrated the heritability of many of these disorders. Genetic linkages and
associations have been reported and replicated, although there have been
inconsistencies between studies, apparently due to the low statistical power of
the samples studied to detect small effects genes. Nonreplications of early
linkage reports in manic-depressive illness in the 1980s occurred when new cases
developed in the same large families in which the linkage was originally
reported, and the newly ill persons had the wrong genetic markers in the linkage
region. This appears to have resulted from applying inappropriate analytic
assumptions of single-gene dominant inheritance of a rare gene, which implied
that new cases must arise from the same ancestral gene within the pedigree. When
new cases arose in family members not sharing that chromosomal region, the
initial linkage report was proved invalid. Under oligogenic inheritance, on the
other hand, susceptibility genes are expected to be common, and have a
substantial probability of being brought into the pedigree by persons marrying
in. Nonspecific psychopathology genes may exist, shared by schizophrenia and
bipolar illness, diagnoses which do not co-aggregate in families. The discovery
of susceptibility mutations may be expected.
PMID- 10682222
TI - Susceptibility loci for bipolar disorder: overlap with inherited vulnerability to
schizophrenia.
AB - Genetic epidemiological studies reveal that relatives of bipolar probands are at
increased risk for recurrent unipolar, bipolar, and schizoaffective disorders,
whereas relatives of probands with schizophrenia are at increased risk for
schizophrenia, schizoaffective, and recurrent unipolar disorders. The overlap in
familial risk may reflect shared genetic susceptibility. Recent genetic linkage
studies have defined confirmed bipolar susceptibility loci for multiple regions
of the human genome, including 4p16, 12q24, 18p11.2, 18q22, 21q21, 22q11-13, and
Xq26. Studies of schizophrenia kindreds have yielded robust evidence for
susceptibility at 18p11.2 and 22q11-13, both of which are implicated in
susceptibility to bipolar disorder. Similarly, confirmed schizophrenia
vulnerability loci have been mapped, too, for 6p24, 8p, and 13q32. Strong
statistical evidence for a 13q32 bipolar susceptibility locus has been reported.
Thus, both family and molecular studies of these disorders suggest shared genetic
susceptibility. These two groups of disorders may not be as distinct as current
nosology suggests.
PMID- 10682223
TI - Pharmacogenetics of antipsychotic treatment: lessons learned from clozapine.
AB - The reintroduction of clozapine, the prototype of atypical antipsychotics, in the
late 1980s has led to significant advances in the pharmacological management of
schizophrenia. Since then, there has been a rapid development of novel "atypical"
antipsychotic agents that have been pharmacologically modeled, to a certain
extent, after their predecessor clozapine. As with all antipsychotics, there is
variability among individuals in their response to these "atypical" drugs.
Pharmacogenetics can provide a foundation for understanding this interindividual
variability in antipsychotic response. This review first provides a rationale for
the pharmacogenetic investigation of this variable trait. Studies of
pharmacokinetic and pharmacodynamic factors of antipsychotic therapy are
considered in the development of this rationale. Next, the molecular genetic
techniques used to study this interindividual variation in response are
described. This is followed by a review and discussion of the published studies
examining genetic factors involved in clozapine response. From this, several
recommendations for future pharmacogenetic investigations of antipsychotic
response are proposed. Although still in its early stages, psychiatric
pharmacogenetics should provide a basis for individualized pharmacotherapy of
schizophrenia, and may also lead to the development of newer, more efficacious
antipsychotic agents.
PMID- 10682224
TI - Multiple antioxidants in the prevention and treatment of Alzheimer disease:
analysis of biologic rationale.
AB - The etiology of Alzheimer disease (AD) is not well understood; therefore, neither
prevention strategies nor long-term effective treatment modalities are available
for this disease. Based on laboratory and clinical studies, it appears that
reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are
generated extracellularly and intracellularly by various mechanisms are among the
major intermediary risk factors that initiate and promote neurodegeneration in
idiopathic AD. Therefore, multiple antioxidant supplements could be useful in the
prevention of AD, and as an adjunct to standard therapy in the treatment of AD.
The products of inflammatory reactions such as prostaglandins (PGs; PGE1 and
PGA1), free radicals, cytokines, and complement proteins are neurotoxic.
Nonsteroidal antiinflammatory drugs (NSAIDs), which inhibit the synthesis of PGs,
reduce the rate of deterioration of cognitive functions in patients with advanced
AD. Cholinergic drugs are routinely used in the treatment of AD to improve
cognitive functions. Therefore, we propose that a combination of multiple
antioxidants and NSAIDs may be more beneficial in the prevention of AD, and that
this combination taken together with cholinergic drugs may be more effective in
the treatment of AD than the individual agents alone. We also hypothesize that,
in idiopathic AD, epigenetic components of neurons such as mitochondria,
membranes, other membranous structures, and protein modifications--rather than
the genes of neurons--are the primary targets for the action of neurotoxins
including free radicals. In some familial AD, mutations in amyloid precursor
protein and presenilins are associated with the risk of early onset of this
disease; however, their mechanisms of action are not fully understood.
PMID- 10682225
TI - Combined electroconvulsive-clozapine therapy.
AB - We reviewed 36 reported psychiatric patients who were treated with a combination
of electroconvulsive therapy (ECT) and clozapine. The indication of the ECT
clozapine treatment was resistance to classical antipsychotic agents, clozapine,
or ECT alone. Sixty-seven percent of the patients benefited from the combined
treatment. In most of the patients, the combined treatment was safe and well
tolerated. Adverse reactions occurred in 16.6% of the patients and included
prolonged ECT-induced seizures (one case), supraventricular (one case) and sinus
tachycardia, and blood pressure elevation. It seems that combined ECT-clozapine
treatment is effective and safe. This strategy may be a therapeutic option in
treatment-resistant patients.
PMID- 10682226
TI - Lack of residual sedation following middle-of-the-night zaleplon administration
in sleep maintenance insomnia.
AB - The present randomized, double-blind, placebo and active-drug controlled,
crossover study assessed residual sedation after zaleplon 10 mg, flurazepam 30 mg
(as an active control), and placebo, taken during a nocturnal awakening in
patients with sleep maintenance insomnia. Twenty-two healthy sleep maintenance
insomniacs (11 men; mean age, 42 y) received zaleplon, flurazepam, or placebo
after an experimental awakening 3.5 hours after bedtime on two consecutive nights
in each of three conditions. Residual sedation was measured with sleep latency
testing (5 and 6.5 h postdrug), digit symbol substitution, symbol copying, and
subjective sleepiness by visual analog scale, each twice each morning. Zaleplon
did not differ from placebo on any measure of residual sedation; flurazepam
showed significant sedation on all measures. No residual sedative effects were
detected 5 or 6.5 hours after ingestion of zaleplon during the middle of the
night by sleep maintenance insomniacs.
PMID- 10682227
TI - Multiple-dose pharmacokinetics of selegiline and desmethylselegiline suggest
saturable tissue binding.
AB - The goal of this study was to examine the multiple-dose pharmacokinetics of
selegiline and its metabolites desmethylselegiline, 1-methamphetamine, and 1
amphetamine after oral administration of selegiline HCl. Twelve healthy
volunteers received 10 mg of selegiline HCl once daily for 8 days. The
pharmacokinetic profiles of selegiline and the metabolites were examined from
serum samples for 24 hours (i.e., the dosing interval, tau) on days 1, 4, and 8.
The results indicated significant apparent accumulation of selegiline and
desmethylselegiline during the 8-day period of selegiline administration. The AUC
tau S of selegiline and desmethylselegiline were increased 2.7 fold (p < 0.001)
and 1.5 fold (p < 0.001), respectively, from day 1 to day 8. However, the half
lives of selegiline (range, 1.5-3.5 h) and desmethylselegiline (range, 3.4-5.3 h)
were found to be relatively short. Accordingly, the short half-lives of these
compounds failed to predict the apparent accumulation. With both of the 1
amphetamine metabolites of selegiline, steady state was reached by day 4. We
suggest that the most likely explanation for the apparent accumulation of
selegiline and desmethylselegiline was the saturation of the MAO-B binding sites
in tissues, although decreased first-pass metabolism of selegiline cannot be
ruled out. The observed increase in selegiline and desmethylselegiline
concentrations on multiple dosing is not likely to significantly increase the
pharmacodynamic effect or adverse effects of selegiline compared with what has
been found after a single 10-mg dose.
PMID- 10682228
TI - Diurnal motor variations to repeated doses of levodopa in Parkinson's disease.
AB - Patients with Parkinson's disease (PD) in long-term levodopa therapy often
complain of worsening of motor symptoms in the afternoon and evening. The
pathophysiology of this phenomenon is not known. We evaluated the motor response
to repeated doses of levodopa during a 12-hour period in 52 parkinsonian patients
(19 de novo, 20 stable, and 13 wearing-off). On the day of the study, all
patients received standard doses of levodopa/carbidopa at 8:00 a.m., 12:00 noon,
and 4:00 p.m. Motor measurements such as tapping test, walking time, and tremor
score, and blood samples for levodopa and 3-O-methyldopa (3OMD) plasma analysis,
were performed hourly. Mean motor scores and pharmacokinetic data, evaluated for
a period of 3 hours after each levodopa dose, were compared. In de novo patients,
we did not observe diurnal changes in motor score, whereas a progressive daytime
worsening was visible in stable and wearing-off patients. No significant
difference in levodopa pharmacokinetics after each levodopa dose was observed
within each patient group, whereas 3OMD plasma levels significant increased with
repeated levodopa administrations. However, no significant correlation between
motor scores and 3OMD plasma levels was observed, suggesting that the diminishing
motor response to afternoon and evening doses of levodopa in patients in long
term levodopa therapy does not relate to the pharmacokinetics of the drug. It is
possible that this phenomenon may be an expression of the occurrence of tolerance
to repeated doses of levodopa.
PMID- 10682229
TI - A randomized controlled trial comparing pramipexole with levodopa in early
Parkinson's disease: design and methods of the CALM-PD Study. Parkinson Study
Group.
AB - CALM-PD (Comparison of the agonist pramipexole with levodopa on motor
complications of Parkinson's disease) is a randomized, multicenter, double-blind,
controlled clinical trial designed to compare the policy of initial treatment of
pramipexole with the policy of initial treatment with levodopa in early,
symptomatic Parkinson's disease with regard to the development of dopaminergic
motor complications. At 22 American and Canadian sites, 301 eligible subjects
requiring antiparkinsonian therapy to treat emerging disability were enrolled in
CALM-PD and randomized to (i) active pramipexole and placebo levodopa or (ii)
placebo pramipexole and active levodopa. Subjects are being evaluated
systematically at regular intervals during a 23.5-month period to determine if
and when dopaminergic motor complications (wearing off, dyskinesias, "on-off"
effects) occur. In addition, quality-of-life outcomes, economic outcomes, and
functional imaging outcomes are being assessed in standard fashion with [123I]
beta-CIT and SPECT imaging throughout the trial. The study design contains many
provisions to approximate routine clinical practice and to produce data about
clinical effectiveness, tolerability, and cost to facilitate the evidence-based
practice of neurology.
PMID- 10682230
TI - Gabapentin treatment for muscle cramps: an open-label trial.
AB - To evaluate the efficacy and safety of gabapentin in the treatment of muscle
cramps, we engaged an open-label trial with a group of 30 patients with frequent
(> 5 cramps/week), stable, long-lasting cramps, associated with different
diseases. Gabapentin was effective in reducing the frequency and severity of
muscle cramps and associated sleep disturbances (clinical outcome measures)
within the first 2 weeks of medication at 600 mg/d. At the 1 month control (mean
dosage, 825 +/- 35 mg), almost every patient had responded to treatment and two
thirds experienced a total remission of symptoms. After 3 months of therapy (mean
dosage, 892 +/- 180 mg), cramps disappeared in 100% of patients and this benefit
persisted as long as 6 months. Additionally, we evaluated in 10 patients the
Cramps Threshold Frequency (CTF) (neurophysiological outcome measure) before and
during gabapentin treatment. Gabapentin significantly increased the CTF,
returning it to normal values. With the limitation of an open-label methodology,
our clinical and neurophysiologic experience suggests that a gabapentin dose of
600-1200 mg/d would be helpful in the treatment of muscular cramps.
PMID- 10682231
TI - Bradykinesia in Huntington's disease.
AB - Huntington's disease (HD) is characterized by the presence of hyperkinesias, but
bradykinesia is also present in most patients. We studied the motor performance
of 18 patients with genetically proven HD (age, 38.5 +/- 10 y; clinical stage,
1.7 +/- 1.7; (CAG) triplet length, 49.2 +/- 6.8 triplets; all but three patients
were free from neuroleptics) and compared with a control group (n = 18) and with
a typical Parkinson's disease (PD) group (n = 20). Motor study included the four
timed tests commonly used for PD: Pronation-supination (PS), finger dexterity
(FD), movement between two points (MTP) and walking test (WT). Tests were done at
9 AM. The PD group was studied in "off" condition, with no medication given for
12 hours. The HD group was slower than the controls on all tasks (all tests
significant, p < 0.01, Mann-Whitney U test) and even slower than PD group (for
FD, p < 0.05). A significant correlation was found between each test and clinical
stage (for PS, r = 0.84; for FD, r = 0.75; for MTP, r = 087, and for WT, r =
0.77, Pearson). Severe bradykinesia was present in HD, and motor impairment is
related to clinical stage.
PMID- 10682232
TI - Asterixis induced by gabapentin.
AB - We report the case of a patient with postherpetic neuralgia who developed
asterixis while being treated with gabapentin. We discuss the possible mechanism
of asterixis in this patient.
PMID- 10682233
TI - Central nervous system side effects associated with zolpidem treatment.
AB - Zolpidem is one of the newer medications developed for the treatment of insomnia.
It is an imidazopyridine agent that is an alternative to the typical sedative
hypnotic agents. Zolpidem use is gaining favor because of its efficacy and its
side effect profile, which is milder and less problematic than that of the
benzodiazepines and barbiturates used to treat insomnia. Still, side effects are
not uncommon with zolpidem use. We report a series of cases in which the patients
developed delirium, nightmares and hallucinations during treatment with zolpidem.
We will review its pharmacology, discuss previous reports of central nervous
system side effects, examine the impact of drug interactions with concurrent use
of antidepressants, examine gender differences in susceptibility to side effects,
and explore the significance of protein binding in producing side effects.
PMID- 10682234
TI - Intravenous administration of levodopa ameliorated a refractory akathisia case
induced by interferon-alpha.
AB - A 28 year-old man with chronic hepatitis B was administered interferon-alpha (5 x
10(6) IU) intramuscularly once a day for 28 days. Eight days after the end of
interferon treatment, he showed signs of inability to sit still for ten seconds
and walked around constantly. His akathisia symptoms worsened thereafter.
Clonazepam, thioridazine, beta-blockers, anticholinergics, and bromocriptine did
not ameliorate his akathisia. Two days' administration of levomepromazine 100 mg
led him to a coma for 2 days. Intravenous levodopa 25 mg ameliorated his
akathisia symptoms drastically. He became completely premorbid 2 weeks after
administration of levodopa. The present report illustrates a rare case of
refractory akathisia after interferon-alpha treatment and also that levodopa
treatment would be theoretically and practically useful in reducing the
neurotoxicity associated with interferon-alpha.
PMID- 10682235
TI - Resting and maximal heart rates in ectothermic vertebrates.
AB - Resting and maximal heart rates (HR) in ectothermic vertebrates are generally
lower than those in endotherms and vary by more than an order of magnitude
interspecifically. Variation of HR transcends phylogeny and is influenced by
numerous factors including temperature, activity, gas exchange, intracardiac
shunts, pH, posture, and reflexogenic regulation of blood pressure. The
characteristic resting HR is rarely the intrinsic rate of the pacemaker, which is
primarily modulated by cholinergic inhibition and adrenergic excitation in most
species. Neuropeptides also appear to be involved in cardiac regulation, although
their role is not well understood. The principal determinants of resting HR
include temperature, metabolic rate and hemodynamic requirements. Maximal HRs
generally do not exceed 120 b min-1, but notable exceptions include the
heterothermic tuna and small reptiles having HRs in excess of 300 b min-1 at
higher body temperatures. Temperature affects the intrinsic pacemaker rate as
well as the relative influence of adrenergic and cholinergic modulation. It also
influences the evolved capability to increase HR, with maximal cardiac responses
matched to preferred body temperatures in some species. Additional factors either
facilitate or limit the maximal level of HR, including: (1) characteristics of
the pacemaker potential; (2) development of sarcoplasmic reticulum as a calcium
store in excitation-contraction coupling; (3) low-resistance coupling of
myocardial cells; (4) limitations of force development imposed by rate changes;
(5) efficacy of sympathetic modulation; and (6) development of coronary
circulation to enhance oxygen delivery to myocardium. In evolutionary terms, both
hemodynamic and oxygen requirements appear to have been key selection pressures
for rapid cardiac rates.
PMID- 10682236
TI - Regulation of cardiac rhythm in hibernating mammals.
AB - The dramatic fall in heart rate exhibited by mammals entering hibernation begins
before there is any noticeable fall in body temperature. The initial, progressive
decrease in heart rate is the result of a cyclic parasympathetic activation that
induces skipped beats and regular asystoles as well as slows the even heart beat.
As body temperature subsequently falls, the parasympathetic influence is
progressively withdrawn and periods of parasympathetic and sympathetic dominance
alternate and give rise to regular periods of arrhythmia (tachycardia followed by
bradycardia), and occasional long asystoles or periods of highly irregular
cardiac activity. Superimposed on this is a vagally-mediated, respiratory sinus
arrhythmia that is accentuated in species that breathe episodically. These events
give way to a uniform heart rate in deep hibernation at low temperatures where
both parasympathetic and sympathetic tone appear absent. The complete absence of
tone is not a function of reduced temperature but is reflective of the state of
deep, steady state hibernation. The elevation in heart rate that accompanies the
onset of arousal is the result of dramatic increases in sympathetic activation
that precede any increases in body temperature. As body temperature then rises,
sympathetic influence is slowly withdrawn. Arrhythmias are also common during
natural arousals or shifts from lower to warmer hibernation temperatures as
periods of parasympathetic and sympathetic dominance again alternate en route to
re-establishing a steady state in euthermia. The mechanism behind, and the
biological significance of, cardiac changes mediated through orchestrated
arrhythmias remain unknown.
PMID- 10682237
TI - Control and interaction of the cardiovascular and respiratory systems in anuran
amphibians.
AB - In anuran amphibians, respiratory rhythm is generated within the central nervous
system (CNS) and is modulated by chemo- and mechanoreceptors located in the
vascular system and within the CNS. The site for central respiratory
rhythmogenesis and the role of various neurotransmitters and neuromodulators is
described. Ventilatory air flow is generated by a positive pressure, buccal force
pump driven by efferent motor output from cranial nerves. The vagus (cranial
nerve X) also controls heart rate and pulmocutaneous arterial resistance that, in
turn, affect cardiac shunts within the undivided anuran ventricle; however,
little is known about the control of central vagal motor outflow to the heart and
pulmocutaneous artery. Anatomical evidence indicates a close proximity of the
centers responsible for respiratory rhythmogenesis and the vagal motoneurons
involved in cardiovascular regulation. Furthermore, anurans in which phasic
feedback from chemo- and mechanoreceptors is prevented by artificial ventilation
exhibit cardiorespiratory interactions that appear similar to those of conscious
animals. These observations indicate interactions between respiratory and
cardiovascular centers within the CNS. Thus, like mammals and other air-breathing
vertebrates, the cardio-respiratory interactions in anurans result from both
feedback and feed-forward mechanisms.
PMID- 10682238
TI - Environmental influences on the development of the cardiac system in fish and
amphibians.
AB - In poikilothermic animals body temperature varies with environmental temperature,
and this results in a change in metabolic activity (Q10 of enzymatic reactions
typically is around 2-3). Temperature changes also modify gas transport in body
fluids. While the diffusion coefficient increases with increasing temperatures,
physical solubility and also hemoglobin oxygen affinity decrease. Therefore, an
increase in temperature typically requires adjustments in cardiac activity
because ventilatory and convectional transport of respiratory gases usually are
tightly coupled in adults in order to meet the oxygen demand of body tissues.
Hypoxic conditions also provoke adaptations in the central circulatory system,
like the hypoxic bradycardia, which has been described for many adult lower
vertebrates, combined with an increase in stroke volume and peripheral
resistance. In embryos and larvae the situation is much more complicated, because
nervous control of the heart is established only late during development, and
because the site of gas exchange changes from mainly cutaneous gas exchange
during early development to mainly pulmonary or branchial gas exchange in late
stages. In addition, recent studies in amphibian and fish embryos and larvae
reveal, that at least in very early stages convectional gas transport of the
hemoglobin is not essential, which means that in these early stages ventilatory
and convectional gas transport are not yet coupled. Accordingly, in early stages
of fish and amphibians the central cardiac system often does not respond to
hypoxia, although in some species behavioral adaptations indicate that oxygen
sensors are functional. If a depression of cardiac activity is observed, it most
likely is a direct effect of oxygen deficiency on the cardiac myocytes. Regulated
cardiovascular responses to hypoxia appear only in late stages and are similar to
those found in adult species.
PMID- 10682239
TI - Metabolic and ventilatory responses to hypoxia in two altitudinal populations of
the toad, Bufo bankorensis.
AB - Effects of hypoxia on resting oxygen consumption (MO2), lung ventilation, and
heart rate at different ambient PO2 were compared between lowland and high
altitude populations of the toad, Bufo bankorensis. Resting MO2 decreased
significantly in mild hypoxia (PO2 = 120 mm Hg) at 10 degrees C and in moderate
hypoxia (PO2 = 80 mm Hg) at 25 degrees C in both altitudinal populations;
however, resting MO2 did not differ significantly between the two populations.
Numbers of lung ventilation periods (VP) and total inspired volume (VL) did not
change with PO2 at 10 degrees C, but did increase at moderate and severe hypoxia
(40 mm Hg), respectively, at 25 degrees C. Resting heart rates did not change
during hypoxia and did not differ between altitude populations. The results
suggest (1) the effect of PO2 change on MO2 should be considered in future
studies involving transfer of anurans to a different altitude; and (2) the
metabolic and ventilatory physiology in B. bankorensis does not compensate for
the low temperature and PO2 at high altitude.
PMID- 10682240
TI - Genetic, environmental and maternal influences on embryonic cardiac rhythms.
AB - The relative roles of an animal's genetic constituents and environmental factors
in influencing physiological variables such has heart rate have not been
extensively investigated. This paper considers how heart rate patterns in the
developing animal can be regulated, and how a combination of 'nature' and
'nurture' may interact to produce discrete patterns of heart rate change during
development. The concept of the 'developmental trajectory' is evoked to generate
a conceptual framework for how physiological development can be perturbed by
environmental factors. Data are provided from three species showing how 'clutch
effects' (the fact that siblings perform physiologically much more similarly than
non-siblings) can greatly influence the variance observed when collecting data on
heart rate during development. Finally, so-called 'maternal effects', which are
the influences on embryos of environmental experiences of the parents, are
discussed as potentially confounding effects in the study of the genetic basis
for physiological patterns of change during development.
PMID- 10682241
TI - Biological rhythms in birds--development, insights and perspectives.
AB - The aim of this review is to show that probably the internal clock of precocial
birds is imprinted in the prenatal period by exogenous factors (zeitgeber). The
activity of organ functions occurs early during embryonic development, before
this function is ultimately necessary to ensure the survival of the embryo.
Prenatal activation of some functional systems may have a training effect on the
postnatal efficiency. The development of physiological control systems is
influenced by endogenous and exogenous factors during the late prenatal and early
postnatal period: epigenetic adaptation processes play an important role in the
development of animals; they have acquired characteristics which are innated but
not genetically fixed. As a rule, the actual value during the determination
period has a very strong influence on the set-point of the system. This will be
explained using the example of thermoregulation. It is shown in detail that it
seems to be possible to imprint the prenatal development of circadian rhythms by
periodic changes of the light-dark cycle but not by rhythmic influence of
acoustic signals. Altogether, there are more questions open than solved
concerning the perinatal genesis of circadian rhythms in birds. Topics are given
for the future research.
PMID- 10682242
TI - Long-term telemetry of heart rates and energy metabolic rate during the diurnal
cycle in normothermic and torpid African blue-naped mousebirds (Urocolius
macrourus).
AB - Colies are one of the phylogenetically oldest groups among the modern birds; the
earliest finds are from about 35 million years ago. In states of energy
deficiency they can undergo torpor during the night when metabolic rate and body
temperature are decreased drastically to save energy (up to 90%). Here, we report
the first measurements of heart rate (HR) by long-term telemetry, in seven
individuals of blue-naped mousebirds (Urocolius macrourus); simultaneously and
continuously metabolic rate (MR) was determined. HR at night was about 20% below
the range of expected values (246/310 bpm). Mean oxygen pulse (O2 output/stroke)
in normothermic birds was in a range of 0.019-0.020 ml O2/stroke; during torpor
nights this value decreased significantly to 0.0086. Mean cardiac output ranged
from 724 to 1214 ml blood/kg per min; in torpid birds this value fell to 400 ml
blood/kg per min. Cardiac regulation of metabolic demand within an activity phase
(day or night) is mainly achieved by chronotropy. Inotropy contributes at most
25% to the differences in MR between day and night (ca. 40%). Entry into torpor
is brought about mainly by changes in HR (decrease from 240 to 90 bpm); after
torpor levels have been reached, there is an increase in HR (to 200 bpm) and a
sharp decrease (-53%) in stroke volume. This regulation by inotropy is also
characteristic of arousal from torpor.
PMID- 10682243
TI - Understanding autonomic sympathovagal balance from short-term heart rate
variations. Are we analyzing noise?
AB - Heart rate variations reflect the output of the complex control of the heart
mediated by the autonomic nervous system. Because of that, they also encode
different types of information, namely the efferent outflow of reflex mechanisms
involved in the beat-to-beat control of cardiac function, the efferent activity
of neurohumoral elements involved in the control of other cardiovascular
parameters and random noise resulting from the hysteresis of the different
controllers. The degree to which power spectrum estimation methods will uncover
the periodic component of heart rate variations is in direct relation with the
status of the system under study. Although the utility of spectral methods is now
established in mammalian research, very little is known on the utility of these
techniques in non-mammalian cardiovascular research. This review covers this
space by discussing the physiological significance of heart rate variations in
non-mammalian vertebrates. A detailed account of the different steps of the
technique, its limitations and the ways to overcome these problems are also
presented. These are: the recording of the cardiac event signal, the detection
and digital processing methods, the satisfaction of stationarity conditions, the
problem of spectral leakage and the different methods to estimate the power
spectrum.
PMID- 10682244
TI - Cardiac rhythms in developing chicks.
AB - Instantaneous heart rate (IHR) of chicks was determined by electrocardiogram
measured non-invasively from the day of hatch to day 6 for continuity of
investigation of HR fluctuations from embryos and for ascertainment of HR diurnal
rhythms. In Experiment I, IHR was determined for 1-h periods twice a day, in
daytime and at night, to investigate development of heart rate fluctuations
(variability and irregularities). Chick IHR was substantially more arrhythmic
than embryonic HR and spontaneous acceleration dominated HR fluctuations. Chick
HR fluctuations were categorized into three types; [1] Type I as a widespread
baseline HR (20-50 bpm) due to respiratory arrhythmia, with a mean oscillatory
frequency of 0.74 Hz (range 0.4-1.2 Hz); [2] Type II as low frequency
oscillations of baseline HR, at a mean of 0.07 Hz (range 0.04-0.10 Hz), and [3]
Type III as non-cyclic irregularities, dominated by frequent transient
accelerations. In Experiment II, continuous measurements of HR were made under
conditions of a natural photoperiod, thermoneutrality and with feed available
throughout the first week after hatching and circadian rhythms of HR were
ascertained. HR was very variable in the daytime (250-500 bpm), due in part to
feeding and activity, and decreased to a diurnal low (200-350 bpm) at night when
mean HR was relatively stable. HR fluctuations persisted throughout the diurnal
cycle.
PMID- 10682245
TI - Dynamical systems analysis of arterial blood pressure signals in relation to
heart rate fluctuations in chick embryos.
AB - We attempted a new approach based on a modern dynamical system theory to
reconstruct the arterial blood pressure signals in relation to heart rate
fluctuations of developing chick embryos. The dynamical systems approach in
general is to model a phenomenon that is presented by a single time series record
and approximate the dynamical property (e.g. heart rate fluctuations) of a system
based only on information contained in a single-variable (arterial blood
pressure) of the system. The time-series data of the arterial blood pressure was
reconstructed in 3-dimensional space to draw characteristic orbits. Since the
reconstructed orbits of the blood pressure should retain information contained in
the pressure signals, we attempted to derive instantaneous heart rate (IHR) from
the reconstructed orbits. The derived IHR presenting HR fluctuations coincided
well with the IHR obtained conventionally from the peak-to-peak time intervals of
the maximum blood pressure. Movements of the reconstructed orbits of the arterial
blood pressure in 3-dimensional space reflected HR fluctuations (i.e. transient
decelerations and accelerations).
PMID- 10682246
TI - Development of cardiac rhythms in altricial avian embryos.
AB - Mean heart rate (MHR) was determined during incubation and in hatchlings of 14
altricial avian species to investigate (1) if there is a common developmental
pattern of heart rate in altricial embryos and (2) if heart rate changes during
incubation are correlated with changes in embryonic growth rate. On the basis of
normalized incubation MHR increased approximately linearly in 12 of 14 species
from as early as 30-40% of incubation to that of pipped embryos. The MHR of
hatchlings was equal to or higher than that of pipped embryos in seven species.
Passerine embryos and hatchlings maintained higher MHR in comparison to parrots
of similar egg mass, which may reflect phylogenetic differences in development.
Embryonic MHR increased at a higher rate while embryonic growth rates were
highest during the first 40% of incubation in tit, budgerigar and crow embryos
than during subsequent development when relative growth rates decreased. MHR
became independent of yolk-free wet mass at a smaller fraction of hatchling mass
in budgerigar and crow than in the tit, suggesting that MHR is more likely to
increase continuously after 40% of incubation in small altricial species than
larger species.
PMID- 10682247
TI - Long-term measurement of heart rate in chicken eggs.
AB - Taking advantage of acoustocardiogram (ACG), we measured the heart rate (HR) of
chick embryos continuously from day 12 until hatching and then investigated the
development of HR irregularities (HRI), HR variability (HRV), and the existence
of a circadian rhythm in mean HR (MHR). HRI comprised transient bradycardia and
tachycardia, which first developed on day 14 and 16 in most embryos,
respectively. Transient bradycardia increased in frequency and magnitude with
embryonic development and occurred over periods of up to 30 min in some embryos.
MHR was maximal on around days 14-15 and thereafter decreased to about 250-260
bpm on days 16-18. Baseline HRV, which is an oscillation of the MHR baseline,
occurred as HR decreased from days 15-16 and became predominant on days 17-18.
The magnitude of the baseline oscillations reached up to 50 bpm in some embryos
and the period ranged between about 40-90 min (ultradian rhythm). A circadian
rhythm of MHR was not found in late chick embryos. On days 18-19, embryonic
activities were augmented and then breathing movements began to occur, disturbing
ACG signals and thus making it difficult to measure the HR. Instead, the
development of breathing activities was recorded. Breathing frequency was
irregular at first and then increased to a maximum of about 1.5 Hz prior to
hatching.
PMID- 10682248
TI - Analysis of heart rate in developing bird embryos: effects of developmental mode
and mass.
AB - Bird embryos may be regarded as developing in their thermo-neutral zone, at rest,
and stay in the egg for a fixed period of time until hatching. It is therefore
interesting to investigate if they follow the same 'rule' set for adult
homeotherms, which states that, within a taxonomically or functionally defined
category such as mammals or birds, the number of heart beats throughout the life
span (sL) is more or less constant. This rule stems from the allometric
relationships between heart rate (fH) and body mass (mB) and between sL and mB.
As a step towards understanding the general allometric nature of avian embryonic
physiology we analyzed the fH values of avian embryos in relation to their
incubation span (sI). Data from 30 species were selected from the scientific
literature for the analyses. Values obtained from invasive methods which were
judged to grossly alter natural incubation conditions, or from undefined or
unmatched temperature conditions were not used. These include most values
obtained below the first 30% of the incubation. Also, data obtained after
internal pipping were discarded since hatching activity influences them. Values
for sI and egg mass (mE) as representatives of embryonic mass were also
collected. Embryonic fH was normalized to 70.1-80% sI. At 20.1-30% sI it was only
85% of the value at 70.1-80% sI and increased to a plateau at about 50.1-60% sI.
It was almost constant among species between 50.1 and 60% sI and pre-internal
pipping (PIP) time and thus, the mean fH value between 50.1 and 60% sI and
between 90.1 and 100% excluding pipped eggs (fH) was taken as a representative
value for each given species. The fH (min-1) and the corresponding sI (days)
values for the 30 species, scaled with mE (g) as follows: fH = 371.1.mE-0.112
and: sI = 12.29.mE+0.209. Both powers were significantly different from 0. The
product of fH and sI (fH.sI), representing the total number of heartbeats
throughout the incubation, scaled with mE for the entire data set as follows:
fH.sI = 6.565 x 10(+6).mE+0.096, where the +0.096 power is significantly
different from 0. Values for fH.sI from embryos of altricial birds tended to
concentrate at the low mE end of the plot while those of the precocial ones
tended towards the high end. Separate analyses showed that the mE power for the
combined altricial and semi-altricial species (ASA), and the combined precocial
and semi precocial species (PSP), of log fH.sI against log mE regressions, were
both insignificantly different from 0. Thus, means of fH.sI for ASA and PSP were
calculated. The mean ASA value of 7.27 x 10(+6) heartbeats for fH.sI, was
significantly different from the mean PSP value of 10.93 x 10(+6). The difference
of 3.66 x 10(-6) (33.5%) heartbeats can be attributed to either the more advanced
stage of the PSP hatchlings at hatch, to the larger mE values of these
hatchlings, to the difference in water fraction of the hatchlings or all. The
result of a linear regression of fH.sI against the rate of sI completion (the
inverse of incubation span, fI; day-1) was: fH.10(-6) = 0.205 + 3.940.sI-1. Thus,
the faster is the average rate of development accomplished per day (shorter
incubation) the higher is daily heart rate. Data tended to cluster such that
large eggs, mostly of the PSP type with relatively low fH, complete 2-4% of their
incubation per day, while small, ASA type eggs with relatively high fH, complete
6-8% of their incubation time per day. We conclude that, at this stage of
knowledge, the data is insufficient to resolve whether the different modes of
hatch stage alone can explain differences in the total number of heartbeats
throughout embryonic life among all bird species, or egg mass and water content
differences contribute variability. This should be investigated on a larger
sample of species in more depth.
PMID- 10682249
TI - Development of heart rate rhythmicity in Muscovy duck embryos.
AB - The heart rate (HR) of Muscovy duck embryos (Cairina moschata f. domestica) was
continuously recorded from as early as the 21st day of incubation (D21) until
hatching (D34/35). The aim of the study was to investigate the influence of
phonoperiods consisting of different acoustic stimuli on the course of HR and the
development of HR periodicities during this period. Incubation was carried out at
a constant temperature and in constant darkness. Until D25 HR was dominated by
decelerative fluctuations only, indicating a main input from the parasympathetic
system on the heart. Later sympathetic influences increased progressively. HR
periodicity was investigated by means of chi 2-periodogram and fast Fourier
transformation. Between D26 and D30 statistically significant and stable HR
periodicities developed gradually. They had periods in the range from 5 to 38 h.
Ultra-, circa- and infradian rhythms (< 20, 24 +/- 4 and > 28 h, respectively)
occurred in parallel in some cases in the same embryo. The for the HR course
important periods were dissimilar between individual embryos and had different
intensities. There was no indication that acoustic stimulation (phonoperiods) had
any effect on the development of HR periodicities.
PMID- 10682250
TI - Cardiac rhythms in chick embryos during hatching.
AB - Avian embryos develop within a hard eggshell which permits the measurement of
heart rate while maintaining an adequate gas exchange through the chorioallantoic
membrane. Heart rate has been determined from cardiogenic signals detected either
noninvasively, semi-invasively or invasively with various transducers. Firstly,
we reviewed these previously-developed methods and experimental results on heart
rate fluctuations in prenatal embryos. Secondly, we presented new findings on the
development of heart rate fluctuations during the last stages of incubation, with
emphasis on the perinatal period, which remained to be studied. Three patterns of
acceleration of the instantaneous heart rate were unique to the external pipping
period: irregular intermittent large accelerations, short-term repeated large
accelerations and relatively long-lasting cyclic small accelerations. Besides
these acceleration patterns, respiratory arrhythmia, which comprimised
oscillating patterns with a period of 1-1.5 s, appeared during the external
pipping period. Furthermore, additional oscillating patterns with a period of 10
15 min were found in some externally pipped embryos.
PMID- 10682251
TI - Cardiac responses to first ever submergence in double-crested cormorant chicks
(Phalacrocorax auritus).
AB - Heart rates were recorded from double-crested cormorant chicks during their first
ever and subsequent voluntary head submergences and dives, as well as during
longer dives made after the chicks were accustomed to diving. Despite variation
between chicks, the cardiac response to first ever and subsequent voluntary
submergence (head submergences and dives) was similar to the response observed in
adult cormorants. Upon submersion the heart rate fell rapidly when pre-submersion
heart rate was high (325-350 beats min-1). The heart rate established within the
first second of voluntary submergence was between 230 and 285 beats min-1, well
above resting heart rate (143 beats min-1). The same initial cardiac response
occurred during longer dives performed after the chicks were accustomed to
diving. In these dives the heart rate remained at the level established on
submersion, unlike the response observed in shallow diving adult cormorants in
which the heart rate declined throughout the dive. The heart rate was also
monitored in a separate group of chicks in which the first exposure to water was
during whole body forced submergence. Again, the observed response was similar to
the adult response, although the cardiac response of chicks to forced submergence
was more extreme than to voluntary submergence. Our results do not support the
hypothesis that learning (by conditioning or habituation) is involved in the
cardiac adjustments to voluntary submergence. It is suggested that the initial
cardiac adjustments are reflex in nature and this reflex is fully developed by
the first submergence event. Although the nature of this reflex pathway is
obscure, cessation of breathing before submersion and the close linkage between
breathing and heart rate might provide a plausible mechanism.
PMID- 10682252
TI - MR and CT angiography of the pelvis: clinical and technical considerations.
PMID- 10682253
TI - Radiographic equipment, installation, and radiation protection.
PMID- 10682254
TI - Spatial analytical methods and geographic information systems: use in health
research and epidemiology.
PMID- 10682255
TI - Hepatitis E: an emerging infectious disease.
PMID- 10682256
TI - Hepatitis C-related hepatocellular carcinoma: prevalence around the world,
factors interacting, and role of genotypes.
PMID- 10682257
TI - Epidemiologic studies of leukemia among persons under 25 years of age living near
nuclear sites.
PMID- 10682258
TI - Epidemiology of abdominal aortic aneurysms.
PMID- 10682259
TI - Role of cannabis in motor vehicle crashes.
PMID- 10682260
TI - Analytical studies of enamel fluorosis: methodological considerations.
PMID- 10682261
TI - Longitudinal change in the heights of men and women: consequential effects on
body mass index.
PMID- 10682262
TI - Epidemiology of gestational weight gain and body weight changes after pregnancy.
PMID- 10682263
TI - The unexpected promiscuity of steroid hormones.
PMID- 10682264
TI - Synaptonemal complex analysis in human male infertility.
AB - The fine structural features of human spermatocytes from carriers of some of the
most frequent chromosomal abnormalities are reviewed on the basis of original
data and previous reports from the literature. Special emphasis is given to the
Robert-sonian translocations t (13; 14), to one specific reciprocal translocation
involving chromosome 21, and to Y disomy in spermatocytes from XYY men.
Synaptonemal complex analysis shows that in many carriers of chromosomal
aberrations that lead to pachytene configurations having terminal asynaptic
segments in autosomes, there is a gradual association of these asynaptic segments
with the XY body. This associations with the XY pair is assumed to trigger a
process of germ cell deterioration, presumably through the spreading of the X
chromosome inactivation towards autosomal segments. Another different process of
germ cell deterioration occurs when the X chromosome becomes an univalent, as in
XYY men with persistence of two Y chromosomes in the germ line. The renewed
interest in the examination of spermatocytes from human testicular biopsies is
commented upon.
PMID- 10682265
TI - Presence and localization of molecules related to the cholinergic system in
developing rat testis.
AB - The presence of cholinergic molecules was recently found in male gametes of
different animal species; very little is known from this point of view about the
somatic component of the gonad. In the present study, a contribution is given to
the localization of some cholinergic-like molecules, such as acetylcholinesterase
(AChE), nicotinic acetylcholine and muscarinic acetylcoline (nAchR and mAChR,
respectively) receptors during postnatal development of the testis. Maturation
stages were checked by use of histochemical stainings, such as DAPI for nuclear
shape changes, and PSA binding to reveal acrosomal maturation. The distribution
of cholinergic-like molecules, revealed by immunocytochemical methods in both
gametes and somatic cells, varied with development. Generally, during early
stages, molecules immunologically related to AChE, and to mAChR's were mainly
found in the interstitial and peritubular compartment, while, during maturation,
they were found in Sertoli cells and in differentiating germ cells. nAChR's were
not found in the somatic compartment, except in the blood vessel walls, and were
distributed in mature germ cells, mainly in the flagella. The presence of
cholinergic molecules in somatic as well as germ cells could play a role in cell
to-cell communications affecting testicular cell differentiation and function.
PMID- 10682266
TI - Tubulin isoforms are differently expressed in developing and mature neurons: a
study on the cerebral cortex of newborn and adult rats.
AB - Tubulin heterogeneity was observed in the rat brain, where these proteins can
vary in different neurons suggesting multiple functions. In this paper, the
different expression of tubulins in cerebral cortex between newborn and adult
rats was analyzed by Western blot and immunocytochemical methods, using anti
tubulin antibodies. Our results showed that tubulins were present at higher
levels in the newborn than in the adult cerebral cortex. In newborn rats, a
marked staining of the perikarya and basal dendrites of pyramidal cells was
noted. This significant expression of tubulins in the newborn cerebral cortex
could be related to the major needs of tubulins in developing neurons. The higher
amount in tyrosine-tubulin and class III beta-tubulin could be consistent with
the state of "dynamic instability", typical of the microtubular network of
neurons during brain development.
PMID- 10682267
TI - Occurrence of GABA-transaminase in the thymus gland of juvenile and aged rats.
AB - The occurrence and distribution of GABA-transaminase (GABA-t) activity were
examined in the thymus of juvenile, adult and aged rats, using enzyme
histochemical and biochemical methods. Quantitative image analysis showed that
specific GABA-t reactivity was localized in the wall of the arteries and, to a
lesser extent, to the veins. Only a low activity could be observed in association
with the subcapsular and medullary part of the parenchyma of the thymus. Many
structures resembling nerve fibers also showed low positive reactivity.
Biochemical results gave the following decreasing order of GABA-t activity:
arteries, veins, whole thymus and parenchyma. Histoenzymatic staining and related
values of quantitative analysis of images, are in agreement with the biochemical
results; moreover, they demonstrated that the intensity of histoenzymatic
staining for GABA-t in thymus of rats strongly decreases with age. GABA-t in
thymic tissue is concentrated in blood vessels and particularly in the arteries.
Therefore, our findings do not support the earlier assumptions that GABA-t is
exclusively concentrated in cerebral vessels. Moreover, the decrease of GABA-t
activity during age in thymic tissues may be related to the decrease of thymic
microvessels as consequence of the thymic involution. On the contrary, the thymic
macrovessels show an elevated staining in all ages with an apparent increase due
to the thymic involution.
PMID- 10682268
TI - Developmental pattern of NADPH-diaphorase activity in the peripheral nervous
system of the cichlid fish Tilapia mariae.
AB - The distribution of NADPH-diaphorase activity was studied in the cichlid fish
Tilapia mariae, during the first developmental stages by means of the tetrazolium
salt technique. The reaction product was first found, 48 hours after
fertilization (stage 10), in the cells of the olfactory placodes and in the
superficial neuromasts. A faint positivity was seen in some hair cells of the
otic vesicles. The epithelial cells of the most caudal part of the intestinal
tract showed a strong labeling. At stage 12 (hatch), the reaction product was in
addition detected in scattered enteric neurons surrounding the digestive tract.
At stage 13 (4.5 days after spawning), the reaction product was also found in the
putative sympathetic trunk, which supplies the gill arches and digestive tract.
The epithelial cells of the gastrointestinal canal showed a more strong positive
labeling and two large clusters of cells near the pronephritic tubules (the
putative adrenomedullar tissue) were also labeled. The present results indicate
an early activity of NADPH-diaphorase during the development of the peripheral
nervous system of Tilapia and reveal a gradual maturation of NADPH-diaphorase
positive structures.
PMID- 10682269
TI - Immunohistochemical detection of mutant p53 protein in regional lymph nodes is
associated with adverse outcome in stage II colorectal cancer.
AB - Epidemiologic data identifies a cohort of Duke's B (CRC) patients whose survival
more closely matches that of Duke's C. Lymph node micrometastases may account for
this discrepancy. Lymph node expression of mutant p53 protein (Mp53P) has been
linked to a reduction in survival in Japanese Duke's B patients. We aimed to
determine the significance of nodal p53 expression in European Duke's B patients
using immunohistochemistry. The study comprised 134 consecutive patients who had
resections for CRC between 1984 and 1991. End points were 5 year disease free
survival or CRC related death. Thirty-four subjects did not achieve end points
and were excluded. We examined tumour and nodal sections for Mp53P by
immunohistochemistry and correlated this with survival using a Kaplan-Meier (KM)
and a Cox Proportional hazards model (CPHT). Five year survival was 73%. Fifty
eight percent of primary tumours expressed Mp53P. Tumour p53 expression did
modulate survival behavior. Twenty-six percent of subjects' lymph nodes expressed
Mp53P. Fifty-three per cent of those with positive and 17% of those with negative
lymph nodes died of recurrence. The relative risk for nodal Mp53P expression was
3.1. There was a significant univariate relationship between lymph node p53
expression and mortality. (Log Rank p = 0.028). Multivariate analysis also showed
a significant relationship with mortality. (CPHT p = .03). We conclude that lymph
node expression of Mp53P is associated with increased mortality in Duke's B CRC.
PMID- 10682270
TI - Immunohistochemical detection of lactoferrin in human astrocytomas and multiforme
glioblastomas.
AB - The presence of lactoferrin in astrocytomas, anaplastic astrocytomas and
multiforme glioblastomas was determined by immunohistochemistry; the staining
intensity and the percentage of neoplastic stained cells were graded and
statistical analysis was performed by non-parametric methods. A moderate to
strong diffuse immunoreactivity for lactoferrin was shown in glial elements of
astrocytomas, while the positivity was progressively reduced in anaplastic
astrocytomas and in multiforme glioblastomas, some of which were unstained; a
highly significant difference was found between scores relative to astrocytomas
and glioblastomas. We suggest that the lactoferrin may be produced by neoplastic
astrocytes which permits a greater availability of iron for metabolic cellular
processes. Alternatively, the cytoplasmic localization of lactoferrin in
neoplastic astrocytes may be the consequence of defective or functionally
impaired lactoferrin receptors at the cellular surface.
PMID- 10682271
TI - Autometallographical localisation of Cu and Zn within target cell compartments of
winkles following exposure to Cu&Zn mixtures.
AB - This investigation attempts to determine the usefulness of autometallography to
localise particular metals in certain key tissues of molluscs exposed to metal
mixtures. For this purpose, winkles (Littorina littorea) removed from shell were
exposed to very high concentrations of either copper (Cu), zinc (Zn) or a mixture
of both metals (Cu&Zn) dissolved in sea-water for short periods of time. Protein
bound metals were detected by autometallography as black silver deposits (BSD) on
histological sections of gills, foot, mantle, digestive gland/gonad complex,
stomach and kidney. Copper was localised within cytoplasmic granules of gill
ciliated cells, nephrocytes and stomach epithelial cells as well as within
digestive cell lysosomes. Zinc was essentially found in the basal lamina
(histological sense) of gill, stomach, kidney and digestive gland epithelia. BSD
were also evidenced in cytoplasmic granules of pore cells present in parenchymal
connective tissue of mantle, foot, gill, digestive gland and stomach. Copper and
zinc concentrations were additionally calculated for the whole soft body as well
as for certain organs by atomic absorption spectrophotometry (AAS). According to
AAS, a synergistic phenomenon would contribute to increase the rate of Cu and Zn
accumulation in presence of each other. However, after exposure to Cu&Zn
autometallography did not evidence any synergistic phenomenon, and Cu and Zn were
localised in their respective accumulation sites. In conclusion,
autometallography might indicate the presence of certain metals in the
environment irrespective of factors, such as "metal-metal interaction-like"
phenomena, affecting metal concentrations in soft tissues.
PMID- 10682272
TI - Immunoreactivity of the monoclonal antibody F89/160.1.5 for the human prion
protein.
AB - Monoclonal antibodies (Mab) to the prion protein (PrP) have been critical to the
neuropathological characterisation of PrP-related diseases in human and animals.
Although PrP is highly evolutionary conserved, there is some sequence divergence
among species. We have analysed the F89/160.1.5 Mab raised against the bovine
prion protein for immunoreactivity with the human prion protein. The antibody
recognised the IHFG epitope of the prion protein. An analysis of the Swiss Prot
database confirmed conservation of the epitope in humans. Further
immunohistochemical (IHC) analysis showed a highly sensitive (final concentration
55 ng/ml) and specific antibody for prion detection in humans. The observed
immunoreactivity of the prion protein did not differ from that observed after
staining with the well-known 3F4 (Senetek) monoclonal antibody.
PMID- 10682273
TI - Confocal laser microscopy to investigate myoepithelial cells in tissue blocks.
PMID- 10682274
TI - The estimation of marginal time preference in a UK-wide sample (TEMPUS) project.
PMID- 10682275
TI - Evaluation of oxygen permeability of gas vesicles from cyanobacterium Anabaena
flos-aquae.
AB - The enhancement of oxygen permeability in aqueous medium by addition of
cyanobacterial gas vesicles (GVs) has been examined. The GVs were isolated from
cultures of Anabaena flos-aquae that had been cultivated in photobioreactors and
harvested by dark flotation. Prior to the permeability experiments, the collected
GVs were treated with glutaraldehyde for improved stability. Measurements of
oxygen permeability were made with a polarographic oxygen electrode in
suspensions of various GV volume fractions (0-2.1%). The experimental results
were compared with the values predicted theoretically (Fricke's equation)
assuming different permeability through the GVs (PmGV), ranging from 0 to 8.30 x
10(-4) mol m-1 atm-1 s-1. The former corresponded to impermeable vesicles, the
latter to air at 22 degrees C as if there were no vesicle wall. The best-fit
value of PmGV was 9.9 x 10(-7) mol m-1 atm-1 s-1, ca. 36-fold higher than that in
water. GVs were therefore very permeable to oxygen. However, the value was much
lower than that predicted for air, implying the existence of wall resistance.
PMID- 10682276
TI - Large-scale production of recombinant hepatitis B surface antigen from Pichia
pastoris.
AB - The ability of the Pichia pastoris-based technology for large-scale production of
recombinant hepatitis B virus surface antigen (HBsAg) and both reproducibly
purify HBsAg and remove most of the relevant contaminants was ascertained by
evaluating ten industrial production batches, five in 1993 and five in 1998. At
an early stage, the clarification of mechanically disrupted yeast cells by acid
precipitation renders HBsAg with a purity as low as 3.8 +/- 0.6%. However, by
adsorption/desorption from diatomaceous earth matrix, the purity of HBsAg rapidly
increases to 18.8 +/- 5%, which is suitable for chromatographic processing. This
step also eliminates non-particulated forms of HBsAg, significantly lowers the
amount of carbohydrates and lipids, and concentrates the HBsAg 4.8-fold. Finally,
a sequential purification procedure that includes large-scale immunoaffinity, ion
exchange, and size-exclusion chromatographies further purifies the preparation,
resulting in a product (HBsAg at a concentration of 1.3 +/- 0.2 g l-1) with a
purity of 95% or more. Furthermore, each of the other contaminants measured
reaches the following low levels per 20 micrograms HBsAg: host deoxyribonucleic
acid (< 10 pg), carbohydrates (1.2 +/- 0.02 micrograms), lipids (14 +/- 0.28
micrograms), immunopurification-released immunoglobulin G (less than 100 ppm),
and endotoxins (106.7 +/- 19.3 pg). These values are below those specified for
recombinant DNA hepatitis B vaccines according to World Health Organization (WHO)
guidelines.
PMID- 10682277
TI - Production and in vitro refolding of a single-chain antibody specific for human
plasma apolipoprotein A-I.
AB - An active form of single-chain antibody (scFv) has been produced in Escherichia
coli for murine monoclonal antibody MabA34 (gamma 1, kappa), which is specific
for human plasma apolipoprotein (apo) A-I. The complementary DNAs (cDNAs)
encoding the variable regions of heavy chain (VH) and light chain (VL) were
connected by a (Gly4Ser)3 linker using an assembly polymerase chain reaction. The
construct (VL-linker-VH) was placed under the control of highly efficient T7
promoter system. The cloned scFv was expressed in E. coli as inclusion bodies.
After purification from E. coli lysate using sonication and low speed
centrifugation, the inclusion body was solubilized and denatured in the presence
of 8 M urea, renatured by dialysis, and scFv was finally purified using antigen
affinity chromatography. The purity and activity of purified scFv were confirmed
by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE),
Western blotting and enzyme-linked immunosorbent assay (ELISA). The affinity
constant was determined by a biosensor method using the BIAcore system. The
results showed that the yield of correctly refolded scFv was more than 20 mg l-1
of E. coli flask culture and the specific binding activity to apo A-I was
retained with an affinity constant of 6.74 x 10(-8) M (Kd). A notable thing is
that guanidine-HCl as a denaturant induced more multimeric formation in the
subsequent refolding procedure for the scFv of MabA34 and thus, it was not
suitable as urea was. This fact is uncommon for what is generally known for the
denaturation and refolding of recombinant antibodies.
PMID- 10682278
TI - The stimulation of gene expression by the R region from HTLV-1 and BLV.
AB - The 5' untranslated regions (5'UTR) of mRNA are known to stimulate or inhibit
more or less translation. SR alpha, an association of SV40 early gene promoter
and of the R region plus the first 39 nucleotides of the U5 region (designated as
R) from the human T-cell leukemia virus (HTLV-1) is currently used to stimulate
expression of various coding regions. Its effect is considered to take place at
the translational level. In all studies published so far, the R region was
associated with the promoter and 5'UTR from SV40 early genes. In the present
work, the role of SV40 5'UTR and HTLV-1R region was evaluated separately using
different promoters, reporter genes and cells. Both SV40 5'UTR (SU) and R region
(R) from HTLV-1 stimulated separately the expression of adjacent reporter genes.
When associated, the SV40 5'UTR and the R region from HTLV-1 (SUR) were a more
potent stimulator of gene expression and their effects were more than additive.
This effect was very potent in HeLa and HC11 cells and almost inexistent in CHO
and COS 7 cells. It was of various intensity in other cell types including bird
and fish cells. The presence of SUR in gene constructs favoured the accumulation
of the mRNAs. SUR stimulated gene expression when added between the cap and the
initiation codon. Unexpectedly, SUR was never inhibitory. SUR can therefore be
considered essentially as potent and specific stimulator of gene expression
favoring mRNA accumulation.
PMID- 10682279
TI - High production of 1,3-propanediol from industrial glycerol by a newly isolated
Clostridium butyricum strain.
AB - Batch and continuous cultures of a newly isolated Clostridium butyricum strain
were carried out on industrial glycerol, the major by-product of the bio-diesel
production process. For both types of cultures, the conversion yield obtained was
around 0.55 g of 1,3-propanediol formed per 1 g of glycerol consumed whereas the
highest 1,3-propanediol concentration, achieved during the single-stage
continuous cultures was 35-48 g l-1. Moreover, the strain presented a strong
tolerance at the inhibitory effect of the 1,3-propanediol, even at high
concentrations of this substance at the chemostat (e.g. 80 g l-1). 1,3
Propanediol was associated with cell growth whereas acetate and butyrate seemed
non growth-associated products. At low and medium dilution rates (until 0.1 h-1),
butyrate production was favoured, whereas at higher rates acetate production
increased. The maximum 1,3-propanediol volumetric productivity obtained was 5.5 g
l-1 h-1. A two-stage continuous fermentation was also carried out. The first
stage presented high 1,3-propanediol volumetric productivity, whereas the second
stage (with a lower dilution rate) served to further increase the final product
concentration. High 1,3-propanediol concentrations were achieved (41-46 g l-1),
with a maximum volumetric productivity of 3.4 g l-1 h-1. A cell concentration
decrease was reported between the second and the first fermentor.
PMID- 10682280
TI - Intracellular glucose 6-phosphate content in Streptomyces coelicolor upon
environmental changes in a defined medium.
AB - A new, chemically defined medium providing dispersed growth and high biomass
formation and a method for quantitative extraction of intracellular metabolites
was used to investigate the cellular response of Streptomyces coelicolor A3(2)
during growth and upon changes in nutrient utilization. Fast changes of the
glucose 6-phosphate content precisely signaled transitions in the flow of carbon
sources. The results indicate that intracellular pool sizes may be used to detect
early nutrient limitations in view of the onset of antibiotic production.
Additionally the results disclose characteristics of the regulation of maltose
and glutamic acid uptake and degradation in S. coelicolor A3(2).
PMID- 10682281
TI - Engineering of a proteolytically stable human beta 2-adrenergic receptor/maltose
binding protein fusion and production of the chimeric protein in Escherichia coli
and baculovirus-infected insect cells.
AB - The hydrophobic human beta 2 adrenergic receptor was produced in fusion to the
hydrophilic maltose-binding protein (MalE) in Escherichia coli. Photoaffinity
labeling with the adrenergic ligand [125I]cyanopindolole-diazirine indicated that
the majority of the protein was proteolyzed in the intergenic region between the
fusion partners after production in E. coli. The simple and fast genetics of the
bacterium enabled us to engineer a linker with an increased proteolytic
stability. The fusion protein produced in E. coli was fully functional with
respect to binding of adrenergic ligands and coupling to stimulatory GTP-binding
protein. The production level with 3 pmol receptor fusion protein per mg membrane
protein in a crude membrane preparation was significantly higher than those
reported for other beta 2 adrenergic receptor constructs in E. coli. After
solubilization with dodecanoyl sucrose, the fusion protein was purified to near
homogeneity by affinity chromatography on immobilized Ni2+ ions (binding to a C
terminal His6-tag) and on crosslinked amylose (binding to the MalE). In order to
achieve higher production levels, the fusion protein preceded by an insect signal
peptide was produced in baculovirus-infected insect cells. As expected, the
production level with about 17 pmol receptor per mg membrane protein was higher
in the insect cells than in E. coli. The receptor fusion protein produced in the
insect cells bound adrenergic ligands and activated heterotrimeric GTP-binding
proteins with biochemical properties comparable to that of the unfused receptor.
PMID- 10682282
TI - Different fungal manganese-oxidizing peroxidases: a comparison between
Bjerkandera sp. and Phanerochaete chrysosporium.
AB - Two manganese-oxidizing peroxidases differing in glycosylation degree were
purified from fermenter cultures of Bjerkandera sp. They were characterized and
compared with the three manganese-oxidizing peroxidase isoenzymes obtained from
the well-known ligninolytic fungus Phanerochaete chrysosporium. All the enzymes
showed similar molecular masses but those from P. chrysosporium had less acidic
isoelectric point. Moreover, the latter strictly required Mn2+ to oxidize
phenolic substrates whereas the Bjerkandera peroxidases had both Mn-mediated and
Mn-independent activity on phenolic and non-phenolic aromatic substrates. Taking
into account these results, and those reported for Bjerkandera adusta and
different Pleurotus species, we concluded that two different types of Mn(2+)
oxidizing peroxidases are secreted by ligninolytic fungi.
PMID- 10682283
TI - Calorimetrically recognized maximum yield of poly-3-hydroxybutyrate (PHB)
continuously synthesized from toxic substrates.
AB - The broader usage of poly-beta-hydroxybutyrate (PHB), for instance as bulk
plastics, calls for cheap raw materials and greater overall process efficiency.
The bacterial synthesis is generally induced and promoted by the limitation of
growth via nitrogen, oxygen or phosphate depletion with the simultaneous excess
and higher concentration of the carbon substrate. Consequently, toxic substrates
have been considered unsuitable for PHB synthesis. Nevertheless, a single-stage
continuous process for producing PHB from toxic substrates using microorganisms
was developed and is reported here. The maximum heat flux during continuous
growth and the maximum yield of PHB versus the substrate consumption rate were
found to coincide. This suggests the possibility of controlling the conversion of
a growth-inhibiting substrate into PHB and maximizing the process efficiency. The
observed correlation occurred irrespective of the substrates investigated (phenol
or sodium benzoate), the PHB-producing strain (Ralstonia eutropha JMP 134 or
Variovorax paradoxus JMP 116), or the type of limitation imposed. The maximum PHB
yields obtained comprised up to 50% of cell dry mass.
PMID- 10682284
TI - Molecular cloning and enzymatic characterization of a Trichoderma reesei 1,2
alpha-D-mannosidase.
AB - A cDNA encoding 1,2-alpha-D-mannosidase mds 1 from Trichoderma reesei was cloned.
The largest open reading frame occupied 1571 bp. The predicted sequence contains
523 amino acid residues for a calculated molecular mass of 56,266 Da and shows
high similarity to the amino acid sequences of 1,2-alpha-D-mannosidases from
Aspergillus saitoi and Penicillium citrinum (51.6 and 51.0% identity,
respectively). T. reesei mannosidase was produced as a recombinant enzyme in the
yeast Pichia pastoris. Replacement of the N-terminal part with the prepro-signal
peptide of the Saccharomyces cerevisiae alpha-mating factor resulted in high
amounts of secreted enzyme. A three-step purification protocol was designed and
the enzymatic properties were analyzed. The enzyme was characterized as a class-I
mannosidase.
PMID- 10682285
TI - Oxirane-immobilized Lentinula edodes laccase: stability and phenolics removal
efficiency in olive mill wastewater.
AB - Immobilization of Lentinula edodes laccase on Eupergit C increased pH, thermal
and proteolytic stability with slight modifications in laccase oxidation
efficiency. Immobilized laccase proved to be efficiently stable in removing olive
mill wastewater phenolics.
PMID- 10682286
TI - Hydrolysis of oleuropein by recombinant beta-glycosidase from hyperthermophilic
archaeon Sulfolobus solfataricus immobilised on chitosan matrix.
AB - The recombinant beta-glycosidase (EcS beta gly) from Sulfolobus solfataricus was
immobilised on chitosan to perform the enzymatic hydrolysis of commercial
oleuropein (heterosidic ester of elenolic acid and 3,4-dihydroxy-phenylethanol
(hydroxytyrosol)) at two temperatures (60 and 70 degrees C). Interestingly, on
the basis of the reasonable assumption that the enzyme hydrolyses only the sugar
linkage, the biotransformation produces unstable aglycone species formed by
oleuropein hydrolysis that, differently from some commercially available beta
glucosidases tested, give rise to the formation of hydroxytyrosol, at the
operative temperatures of the bioreactor. The results of the biotransformation at
70 degrees C showed that the main products are hydroxytyrosol, and glucose, being
the oleuropein aglycone present in low amount at the end of reaction. Both in
single step approach or in recycle approach the amounts of glucose and oleuropein
aglycone were lightly dependent from flow rate. The amount of hydroxytyrosol,
increased on decreasing the flow rate of bioreactor in recycle approach,
following a non-linear trend and obtaining the highest value at a flow rate of 15
ml h-1 while in the single step approach the 3,4-dihydroxy-phenylethanol was at
its maximum at higher flow rate (16 ml h-1). For the hydrolysis of the oleuropein
by bioreactor at 60 degrees C we used lower molar ratio oleuropein/enzyme only by
the single step approach. In these conditions it is possible to obtain high
amounts of only two products (glucose and hydroxytyrosol) in short time (2 h).
The stability of the bioreactor at the operative temperatures showed a t1/2 of 30
days at 70 degrees C and a t1/2 of 56 days at 60 degrees C.
PMID- 10682287
TI - Epoxide hydrolase activity of Streptomyces strains.
AB - The discovery of epoxide hydrolases within a Streptomyces sp. strain collection
is described. Screening was performed in 96 well microtiter plates using a
modified 4-(p-nitrobenzyl)pyridine assay with styrene oxide, 1,2-epoxy-hexane or
3-phenyl ethylglycidate (3-PEG) as substrates. Out of 120 strains investigated,
S. antibioticus Tu4, S. arenae Tu495 and S. fradiae Tu27 exhibited epoxide
hydrolase activity. These strains were further investigated by performing
laboratory-scale biotransformations utilizing styrene oxide, 1,2-epoxy-hexane and
3-PEG followed by subsequent quantitative analysis employing chiral gas
chromatography. The highest conversions were achieved with whole cells from S.
antibioticus Tu4 in the presence of 10% (v/v) DMSO. However, enantioselectivity
was only satisfying (E = 31) in the presence of 5% (v/v) acetone, which allowed
isolation of optically pure non-hydrolyzed (R)-styrene oxide (99% enantiomeric
excess (ee)) and (S)-phenyl-1,2-ethandiol (72% ee) at 55% conversion after 24 h.
The resolution of 3-PEG proceeded with slightly lower enantioselectivity albeit
higher reaction rates. With S. fradiae Tu27 and S. arenae Tu495
enantioselectivity towards styrene oxide was only E = 3-4.
PMID- 10682288
TI - Thirty categorization results in search of a model.
AB - One category structure dominated in the shift toward exemplar-based theories of
categorization. Given the theoretical burden on this category structure, the
authors reanalyzed 30 of its uses over 20 years in 8 articles. The authors
suggest 4 conclusions. (a) This category structure may encourage exemplar
memorization processes because of its poor structure, the learning difficulties
it causes, and its small, memorizable exemplar sets. Its results may only
generalize narrowly. (b) Exemplar models have an advantage in fitting these 30
data sets only because they reproduce a performance advantage for training items.
Other models fit equally well if granted this capacity. (c) A simpler exemplar
process than assumed by exemplar models suffices to explain these data sets. (d)
An important qualitative result predicted by exemplar theory is not found overall
and possibly should not even be expected. The authors conclude that the data
produced by this category structure do not clearly support exemplar theory.
PMID- 10682289
TI - Probability judgment in three-category classification learning.
AB - People give subadditive probability judgments--in violation of probability theory
-when asked to assess each in a set of 3 or more mutually exclusive hypotheses,
as indicated by their sum exceeding 1. Three potential evidential influences on
subadditivity--cue conflict, cue frequency, and cue redundancy--are distinguished
and tested in 5 experiments using a classification-learning task. Results
indicate that (a) judgments of probability and of frequency are systematically
subadditive even when the judgments are based on cues learned within the
experimental context, (b) cue conflict has a reliable influence on the degree of
subadditivity, and (c) judgments in this context are well described by a linear
discounting model within the framework of support theory.
PMID- 10682290
TI - Competition among causes but not effects in predictive and diagnostic learning.
AB - Causal asymmetry is one of the most fundamental features of the physical world:
Causes produce effects, but not vice versa. This article is part of a debate
between the view that, in principle, people are sensitive to causal
directionality during learning (causal-model theory) and the view that learning
primarily involves acquiring associations between cues and outcomes irrespective
of their causal role (associative theories). Four experiments are presented that
use asymmetries of cue competition to discriminate between these views. These
experiments show that, contrary to associative accounts, cue competition
interacts with causal status and that people are capable of differentiating
between predictive and diagnostic inferences. Additional implications of causal
model theory are elaborated and empirically tested against alternative accounts.
The results uniformly favor causal-model theory.
PMID- 10682291
TI - A feature-sampling account of the time course of old-new recognition judgments.
AB - This article describes the feature-sampling theory of recognition (FESTHER), a
new model of the time course of recognition judgments based on a model of the
time course of perceptual processing in categorization (K. Lamberts, 1995, 1998).
FESTHER is applied to previous results and to data from 4 old-new recognition
experiments. Experiments 1 and 2 provided a preliminary test of the model's
ability to explain recognition judgments of simple objects under response
deadlines. Experiments 3 and 4 involved a response-signal procedure to elicit
recognition judgments at different time lags after presentation of a stimulus.
Simple objects and words were used as stimuli in Experiments 3 and 4,
respectively. The new model accounts well for the data from the 4 experiments and
offers a parsimonious account of the time course of recognition judgments based
on the time-dependent availability of stimulus information.
PMID- 10682292
TI - Automatic comparisons of artificial digits never compared: learning linear
ordering relations.
AB - In 2 experiments, participants were trained to perform magnitude decisions, that
is, decide which of 2 arbitrary symbols in a pair represented a larger magnitude.
The symbols corresponded to locations on an implicit linear scale. Training
resulted in a Stroop-like size congruity effect when the participants had to
decide which symbol in a pair was physically larger. This effect, showing
automaticity of the processing of magnitude relations, was also obtained for
pairs never encountered during practice. The implications of these findings for
processing of magnitude relations and for theories of automaticity are discussed.
PMID- 10682293
TI - Priming and attentional control of lexical and sublexical pathways during naming.
AB - A modified priming task was used to investigate whether skilled readers are able
to adjust the degree to which lexical and sublexical information contribute to
naming. On each trial, participants named 5 low-frequency exception word primes
or 5 nonword primes before a target. The low-frequency exception word primes
should have produced a greater dependence on lexical information, whereas the
nonword primes should have produced a greater dependence on sublexical
information. Across 4 experiments, the effects of lexicality, regularity,
frequency, and imageability were all modulated in predictable ways on the basis
of the notion that the primes directed attention to specific processing pathways.
It is argued that these results are consistent with an attentional control
hypothesis.
PMID- 10682294
TI - The role of physical and conceptual properties in preserving object continuity.
AB - Six experiments investigated the nature of the object-file representation
supporting object continuity. Participants viewed preview displays consisting of
2 stimuli (either line drawings or words) presented within square frames,
followed by a target display consisting of a single stimulus (either a word or a
picture) presented within 1 of the frames. The relationship between the target
and preview stimuli was manipulated. The first 2 experiments found that
participants responded more quickly when the target was identical to the preview
stimulus in the same frame (object-specific priming). In Experiments 3, 4, 5, and
6, the physical form of the target stimulus (a word or picture in 1 frame) was
changed completely from that of either preview stimulus (pictures or words in
both frames). Despite this physical change, object-specific priming was observed.
It is suggested that object files encode postcategorical information, rather than
precise physical information.
PMID- 10682295
TI - Updating displays after imagined object and viewer rotations.
AB - Six experiments compared spatial updating of an array after imagined rotations of
the array versus viewer. Participants responded faster and made fewer errors in
viewer tasks than in array tasks while positioned outside (Experiment 1) or
inside (Experiment 2) the array. An apparent array advantage for updating objects
rather than locations was attributable to participants imagining translations of
single objects rather than rotations of the array (Experiment 3). Superior viewer
performance persisted when the array was reduced to 1 object (Experiment 4);
however, an object with a familiar configuration improved object performance
somewhat (Experiment 5). Object performance reached near-viewer levels when
rotations included haptic information for the turning object. The researchers
discuss these findings in terms of the relative differences in which the human
cognitive system transforms the spatial reference frames corresponding to each
imagined rotation.
PMID- 10682296
TI - Path integration while ignoring irrelevant movement.
AB - Participants attempted to return to the origin of travel after following an
outbound path by locomotion on foot (Experiments 1-3) or in a virtual visual
environment (Experiment 4). Critical conditions interrupted the outbound path
with verbal distraction or irrelevant, to-be-ignored movements. Irrelevant
movement, real or virtual, had greater effects than verbal or cognitive
distraction, indicating inability to ignore displacement during path integration.
Effects of the irrelevant movement's direction (backward vs. rightward) and
location (1st vs. 2nd leg of path) indicated that participants encoded a
configural representation of the pathway and then cognitively compensated for the
movement, producing errors directly related to the demands of compensation. An
encoding-error model fit to the data indicated that backward movement produced
downward rescaling, whereas movement that led to implied rotation (rightward on
2nd leg) produced distortions of shape and scale.
PMID- 10682297
TI - On the relation between representations constructed from text comprehension and
transitive inference production.
AB - Deductive inference production from texts is a process considered to involve
either the construction of an integrated mental model or the step-by-step
coordination of propositional representations of the sentences. These alternative
hypotheses were tested in 3 experiments using a set inclusion task paradigm in
which participants had to recall the premises and to evaluate transitive
inferences. Contrary to what is known about linear ordering relations, order of
recalls and reaction times provide evidence that the encoding of set inclusion
relations does not result in an integrated representation. These results suggest
that the mental models theory needs to take account of the nature of the relation
to be represented if it is to become a general theory of reasoning.
PMID- 10682298
TI - Metacognitive and control strategies in study-time allocation.
AB - This article investigates how people's metacognitive judgments influence
subsequent study-time-allocation strategies. The authors present a comprehensive
literature review indicating that people allocate more study time to judged
difficult than to judged-easy items--consistent with extant models of study-time
allocation. However, typically, the materials were short, and participants had
ample time for study. In contrast, in Experiment 1, when participants had
insufficient time to study, they allocated more time to the judged-easy items
than to the judged-difficult items, especially when expecting a test. In
Experiment 2, when the materials were shorter, people allocated more study time
to the judged-difficult materials. In Experiment 3, under high time pressure,
people preferred studying judged-easy sonnets; under moderate time pressure, they
showed no preference. These results provide new evidence against extant theories
of study-time allocation.
PMID- 10682299
TI - Functional characteristics of auditory temporal-spatial short-term memory:
evidence from serial order errors.
AB - The functional characteristics of auditory temporal-spatial short-term memory
were explored in 8 experiments in which the to-be-remembered stimuli were
sequences of bursts of white noise presented in spatial locations separated in
azimuth. Primacy and recency effects were observed in all experiments. A 10-s
delay impaired recall for primacy and middle list items but not recency. This
effect was shown not to depend on the response modality or on the incidence of
omissions or repetitions. Verbal and nonverbal secondary tasks did not affect
memory for auditory spatial sounds. Temporal errors rather than spatial errors
predominated, suggesting that participants were engaged in a process of
maintaining order. This pattern of results may reflect characteristics that
serial recall has in common with verbal and spatial recall, but some are unique
to the representation of memory for temporal-spatial auditory events.
PMID- 10682300
TI - Role of study strategy in recall of mixed lists of common and rare words.
AB - Experiment 1 confirmed previous findings that common words are more recallable
than are rare words when the 2 kinds of words are presented in separate lists but
not when they are presented in the same list. Experiment 2 showed much the same
pattern when an orienting task was performed during word presentation. In
Experiment 3 common words were found to be more recallable than rare words even
for mixed lists when no warning was given of the memory test, although the effect
was less pronounced than for pure lists. In Experiment 4 stronger measures were
taken to preclude anticipation of the memory test, and the effect of word
commonness was found to be just as pronounced with mixed lists as it was with
pure lists. It was suggested that lists are studied in a way believed to optimize
recall and that mixed lists foster a strategy of favoring the rare words.
PMID- 10682301
TI - Implicit learning differences: a question of developmental level?
AB - A. S. Reber's (1992) proposition that the implicit learning system should
demonstrate invariance of intellectual level (IQ) was examined by comparing 20
children with intellectual disability (mean mental age [MA] = approximately 5.8
years) with 20 intellectually gifted children (mean MA = approximately 12.4
years) of similar chronological age (CA; approximately 9.5 years). Implicit
learning was assessed using a task involving covariation of 2 incidental cues.
Explicit learning was assessed using a task of similar logical structure.
Contrary to the IQ-invariance proposition, implicit learning as well as explicit
learning varied with intellectual level. A secondary aim was to distinguish the
contributions of CA, IQ, and MA to implicit learning. This was done by combining
the samples of children in the present study with 2 samples of younger and older
children of average ability from a study by M. Maybery, M. Taylor, and A. O'Brien
Malone (1995). Analyses showed that MA is critical to implicit learning.
PMID- 10682302
TI - Psychiatric symptoms of inherited metabolic disease.
AB - Inborn errors of metabolism often present with a variety of psychiatric symptoms.
With improved diagnosis and treatment options, many patients have increased
lifespans; consequently, issues of long-term quality of life are coming to the
forefront. Mental health concerns are among these issues. To demonstrate the
connection between the course of metabolic disease and its psychiatric
manifestations, four different inborn errors of metabolism are reviewed:
phenylketonuria, Wilson disease, acute intermittent porphyria, and metachromatic
leukodystrophy.
PMID- 10682303
TI - Brain phenylalanine concentration in the management of adults with
phenylketonuria.
AB - Diagnosis by newborn screening and the implementation of a phenylalanine
restricted diet have resulted in normal neurological development in approximately
10,000 persons with phenylketonuria (PKU) in the United States. While it is
accepted that a phenylalanine-restricted diet is necessary in childhood, the
recommended concentration of phenylalanine in the blood varies. Clinicians now
must make recommendations for adults with PKU who probably tolerate higher levels
of phenylalanine than children. This factor, quality of life issues, the expense
of the diet, and varying genetic and socioeconomic backgrounds, make the choice
of dietary recommendations difficult. Molecular analysis of the mutations in PKU
has provided insight but has not resulted in clear recommendations for
phenylalanine concentration in the blood. Magnetic resonance imaging has provided
the recognition that white-matter changes are present in PKU. However, owing to
poor correlation of white-matter changes with clinical factors, analysis of white
matter changes has not proved useful. We hypothesize that measurement of brain
phenylalanine directly will aid in clinical decision making. Twenty-one subjects
with PKU had blood and brain phenylalanine measured simultaneously. Fifteen were
randomly selected, 2 were examined for clinical reasons and 4 exceptional
patients were chosen because they had maintained high IQs, despite having high
historic blood concentrations and having been off the diet for at least 10 years.
The correlation of blood and brain phenylalanine is in general poor. However, the
four exceptional patients all had relatively low concentrations of phenylalanine
in their brains compared to their blood. We suggest that their good clinical
status, despite high historic blood levels, is due to their comparatively low
brain levels of phenylalanine. We further suggest that measurement of brain
phenylalanine concentration is useful in the management of PKU patients.
PMID- 10682304
TI - Treatment of late-onset nonketotic hyperglycinaemia: effectiveness of imipramine
and benzoate.
AB - We report a patient with late-onset nonketotic hyperglycinaemia managed with a
sequential approach to drug therapy in placebo-controlled therapeutic trials.
Partial response to low-protein diet and sodium benzoate and dramatic response to
imipramine are demonstrated, with parental scores on the Developmental
Behavioural Checklist falling from the 86th centile before treatment to normal
with combined benzoate and imipramine therapy.
PMID- 10682305
TI - Effect of sodium benzoate in the treatment of atypical nonketotic
hyperglycinaemia.
AB - A 6-month-old girl presented with hypotonia and mild psychomotor retardation.
Subsequently, an atypical manifestation of a nonketotic hyperglycinaemia was
diagnosed, confirmed by significantly reduced activity of the glycine cleavage
system in the liver tissue. After the patient developed hypsarrhythmia and had a
single cerebral seizure, treatment with both sodium benzoate and dextromethorphan
was started. During the following year, the girl was free of seizures with
improvement of the EEG activity and showed retarded but continuously progressing
psychomotor development. At the age of 20 months she began to walk freely but had
generalized muscular hypotonia and moderate mental retardation. Discontinuation
of dextromethorphan medication after one year of treatment did not change the
clinical and electroencephalographic status. However, after cessation of sodium
benzoate therapy, epileptic activity in the EEG and behavioural changes occurred.
These changes disappeared promptly after sodium benzoate therapy was
reinstituted. Thus, this case of mild atypical nonketotic hyperglycinaemia with
only moderate psychomotor retardation and without epilepsy benefited from
treatment with sodium benzoate in terms of electroencephalographic and
behavioural changes.
PMID- 10682306
TI - Acylcarnitines in fibroblasts of patients with long-chain 3-hydroxyacyl-CoA
dehydrogenase deficiency and other fatty acid oxidation disorders.
AB - Mitochondrial fatty acid oxidation disorders cause hypoglycaemia, hepatic
dysfunction, myopathy, cardiomyopathy and encephalopathy. Despite their
recognition for more than 15 years, diagnosis and treatment remain difficult. To
help design rational diagnostic and therapeutic strategies, we studied the
pathophysiology of accumulating metabolites in a whole-cell system.
Acylcarnitines were quantified in cells and media of cultured fibroblasts after
incubation with L-carnitine and fatty acids. Following incubation with palmitate,
long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD)-deficient fibroblasts compared
with controls showed elevation of hydroxypalmitoyl- and palmitoyl-carnitine and
reduction of C10- and shorter acylcarnitines, and following incubation with
linoleate an increase in C14:2-, C18:2- and hydroxy-C18:2- acylcarnitines and
reduction in C10:1-acylcarnitines. Hydroxyacylcarnitines remained more
intracellular compared to corresponding saturated acylcarnitines. Incubation with
decanoate and octanoate showed absence of hydroxylated acylcarnitines and
correction of secondary metabolic disturbances, suggesting that optimal treatment
should include medium-chain triglycerides of these chain lengths. Fibroblasts of
patients with other fatty acid oxidation disorders showed distinct elevations of
disease-specific acylcarnitines. This acylcarnitine analysis allows the diagnosis
of LCHAD deficiency and its differentiation from other fatty acid oxidation
disorders, which can pose difficulties in vivo. The strategy has allowed in-depth
analysis with different substrates, providing suggestions for the rational design
of treatment trials.
PMID- 10682307
TI - Dietary therapy in two patients with a mild form of sulphite oxidase deficiency.
Evidence for clinical and biological improvement.
AB - We report an attempt at dietetic therapy in two unrelated patients with isolated
sulphite oxidase deficiency, with a mild clinical course and late onset of
symptoms. In case 1, disease started at 15 months with an acute crisis of
agitation, unexplained crying and restlessness following otitis. Case 2 was
diagnosed at 10 months when she presented with slight motor delay and dislocation
of lenses. In both cases, sulphite oxidase activity measured in fibroblasts was
undetectable. Therapy consisted of a diet low in protein from natural foods
(daily methionine intake 130-150 mg) and a synthetic amino acid mixture (50 g per
day) without cystine and methionine (Xmet, Cys Maxamaid, SHS International Ltd).
A comparison of clinical and biochemical parameters was made between the period
before treatment and after 2 years of treatment. Restriction in protein and
sulphur amino acids brought about a dramatic decrease of urinary thiosulphate and
S-sulphocysteine. It also brought about a generalized hypoaminoacidaemia with a
low plasma methionine and cystine in both patients. Furthermore, both patients
grew normally with no signs of neurological deterioration, and there was evidence
of progress in psychomotor development.
PMID- 10682308
TI - Pharmacological and genetic modifications of somatic cholesterol do not
substantially alter the course of CNS disease in Niemann-Pick C mice.
AB - Niemann-Pick type C (NPC) is a neurodegenerative disorder with somatically
altered cholesterol metabolism. The NPC1 gene has recently been cloned and shown
to have sequences shared with known sterol-sensing proteins. We have used a mouse
model with a disrupted Npc1 gene to study two cholesterol-lowering drugs
(nifedipine and probucol) and the effects of introducing a null mutation in the
low-density lipoprotein receptor (LDLR). Although these treatments significantly
ameliorated liver cholesterol storage, little effect on the onset of neurological
symptoms was found.
PMID- 10682310
TI - The natural course of Gaucher disease in The Netherlands: implications for
monitoring of disease manifestations.
AB - This retrospective study in 20 untreated type I Gaucher disease patients shows
that in Dutch patients clinical manifestations of Gaucher disease type I are
progressive in the majority of patients, children as well as adults. This is in
contrast with studies among Jewish patients. Our results emphasize the need for a
regular follow-up to enable timely initiation of enzyme therapy.
PMID- 10682309
TI - A non-glycosylated and functionally deficient mutant (N215H) of the sphingolipid
activator protein B (SAP-B) in a novel case of metachromatic leukodystrophy
(MLD).
AB - The lysosomal degradation of sphingolipids with short oligosaccharide chains
depends on small glycosylated non-enzymatic sphingolipid activator proteins
(SAPs, saposins). Four of the five known SAPs, SAP-A, -B, -C and -D, are derived
by proteolytic processing from a common precursor protein (SAP-precursor) that is
encoded by a gene on chromosome 10 consisting of 15 exons and 14 introns. SAP-B
is a non-specific glycolipid binding protein that stimulates in vitro the
hydrolysis of about 20 glycolipids by different enzymes. In vivo SAP-B stimulates
in particular the degradation of sulphatides by arylsulphatase A. So far, four
different point mutations have been identified on the SAP-B domain of the SAP
precursor gene. The mutations result in a loss of mature SAP-B, causing the
lysosomal accumulation of sulphatides and other sphingolipids, resulting in
variant forms of metachromatic leukodystrophy (MLD). Here we report on a patient
with SAP-B deficiency that is caused by a new homoallelic point mutation that has
been identified by mRNA and DNA analysis. A 643A > C transversion results in the
exchange of asparagine 215 to histidine and eliminates the single glycosylation
site of SAP-B. Metabolic labelling experiments showed that the mutation had no
effect on the intracellular transport of the encoded precursor to the acidic
compartments and its maturation in the patient's cells. All four SAPs (SAP-A to
SAP-D) were detectable by immunochemical methods. SAP-B in the patient's cells
was found to be slightly less stable than the protein in normal cells and
corresponded in size to the deglycosylated form of the wild-type SAP-B. Feeding
studies with non-glycosylated SAP-precursor, generating non-glycosylated SAP-B,
showed that the loss of the carbohydrate chain reduced the intracellular activity
of the protein significantly. The additional structural change of the patient's
SAP-B, caused by the change of amino acid 215 from asparagine to histidine,
presumably resulted in an almost completely inactive protein.
PMID- 10682311
TI - Neurological deterioration in adult phenylketonuria.
PMID- 10682312
TI - The glutamine paradox in a neonate with propionic acidaemia and severe
hyperammonaemia.
PMID- 10682313
TI - Protein, glucose and energy metabolism in Gaucher disease type I.
PMID- 10682314
TI - Increased urine heparan and chondroitin sulphate excretion in patients with
osteopetrosis.
PMID- 10682315
TI - Pyridoxine-responsive nephrocalcinosis and glycolic aciduria in two siblings
without hyperoxaluria and with normal alanine: glyoxalate aminotransferase
activity.
PMID- 10682316
TI - The target hypothesis as a "quantum leap" to gene mutations.
PMID- 10682317
TI - Fukuyama-type congenital muscular dystrophy: the first human disease to be caused
by an ancient retrotransposal integration.
AB - Fukuyama-type congenital muscular dystrophy (FCMD), one of the most common
autosomal recessive disorders in the Japanese population, is characterized by
congenital muscular dystrophy in combination with cortical dysgenesis
(micropolygyria). Recently we identified on chromosome 9q31 the gene responsible
for FCMD, which encodes a novel 461 amino acid protein that we have termed
fukutin. Most FCMD-bearing chromosomes (87%) derive from a single ancestral
founder, whose mutation consisted of a 3-kb retrotransposal insertion in the 3'
noncoding region of the fukutin gene. Two independent point mutations causing
premature termination confirmed that that this gene is responsible for FCMD. FCMD
is the first human disease to be caused by an ancient retrotransposal
integration. Fukutin contains an amino-terminal signal sequence, which together
with results from transfection experiments suggests that it is an extracellular
protein. Discovery of the FCMD gene represents an important step toward greater
understanding of the pathogenesis of muscular dystrophies and also of normal
brain development.
PMID- 10682318
TI - Apoptosis or necrosis for tumor immunotherapy: what's in a name?
AB - Here we discuss how the mechanisms by which tumor cells are killed in vivo by
gene transfer affects their immunogenicity. Our own work has shown that necrotic
cell death induces immunological activation signals which recruit, load, activate
and mature appropriate subsets of antigen-presenting cells. In contrast, for
apoptotic cell death to be immunogenic, signals additional to cell death alone
must be provided within the milieu of the dying tumor. Our conclusion is that the
immunogenicity of tumor killing is determined by a combination of factors,
including the mechanism of killing, the levels of cell death, the local
environment that exists within the dying tumor and, as a result, the nature of
the immune/scavenger cells which are present at the time of antigen release.
Knowledge of how these factors can influence the immune system and lead to the
breaking of tolerance to tumor-associated antigens, can potentially be exploited
in the design of effective immunotherapies for cancer using gene transfer.
PMID- 10682319
TI - Analysis of the genetic diversity of Helicobacter pylori: the tale of two
genomes.
AB - Infection with Helicobacter pylori has been linked to numerous severe
gastroduodenal diseases including peptic ulcer and gastric cancer. Several
techniques have been used to measure the genetic heterogeneity of H. pylori at
several different levels and to determine whether there is any correlation with
severity of disease. The availability of two completed genome sequences from
unrelated strains (J99 and 26,695) has allowed an analysis of the level of
diversity from a large-scale yet detailed perspective. Although the two
chromosomes are organized differently in a limited number of discrete regions,
the genome size and gene order of these two "high-virulence" (cagA+ and vacA+) H.
pylori isolates was found to be highly similar. The regions of organizational
difference are associated with insertion sequences, DNA restriction/modification
genes, repeat sequences, or a combination of the above. A significant level of
variation at the nucleotide level is seen across the genome, providing an
explanation for why the nucleotide-based typing techniques have such high
discriminatory power among independent H. pylori isolates. This nucleotide
variation together with the organizational rearrangements appears to have
provided an over-estimation of the gene order diversity of H. pylori as assessed
by pulse-field gel electrophoresis. Functional assignments are assigned to
approximately only 60% of the gene products in each strain, with one-half of the
remaining gene products of unknown function having homologues in other bacteria,
while the remainder appear to be H. pylori-specific. Between 6% and 7% of the
coding capacity of each strain are genes that are absent from the other strain,
with almost one-half of these strain-specific genes located in a single
hypervariable region called the plasticity zone. The majority of the strain
specific genes in each strain are also H. pylori-specific, with no homologues
being identified in the public databases. Significantly, over one-half of the
functionally assigned strain-specific genes in both H. pylori J99 and 26695
encode DNA restriction/modification enzymes. Analysis of the level of
conservation between orthologues from the two strains indicates that the H.
pylori specific genes have a lower level of conservation than those orthologues
to which a putative function can be assigned. The plasticity zone represents one
of several regions across each genome that is comprised of lower (G+C)% content
DNA, some of which has been detected in self-replicating plasmids, suggesting
that both horizontal transfer from other species and plasmid integration are
responsible for the strain-specific diversity at this locus. These analyses have
yielded results with important implications for understanding the genetic
diversity of H. pylori and its associated diseases, and imply a need to reassess
the respective roles of bacterial and host factors in H. pylori associated
diseases.
PMID- 10682320
TI - Analysis of differentially regulated mRNAs in monocytic cells induced by in vitro
stimulation.
AB - Macrophages are known to be effector cells in several granulomatous disorders.
However, little is known about granuloma-associated up- or downregulation of
genes in these cells. Differential display reverse transcription polymerase chain
reaction (DDRT-PCR) is an attractive method for the detection of differentially
expressed genes. Although this method entails a number of drawbacks, its
application to rare and limited amounts of clinical samples is still convenient.
In this study, we introduce a screening procedure for detecting differentially
regulated sequence tags in samples of patients suffering from granulomatous
diseases. We applied DDRT-PCR in a multiple and complex comparison of expressed
sequence tags in response to various granuloma-associated stimuli. The
histiocytic cell line U937 was used as a model. The cells had been stimulated
with granuloma-associated agents such as Mycobacterium tuberculosis, BeSO4,
lipopolysaccharide, or HgS and unspecific stimuli such as phorbol myristate
acetate, phytohemagglutinin, Zymosan, and Latex. Comparative analysis of 2237
sequence tags obtained from 55 primer combinations revealed 22.4% differentially
amplified PCR products. Notably, only 8.0% of the differentially expressed
sequence tags showed an association restricted to in vitro cultivation in the
presence of M. tuberculosis, lipopolysaccharide, BeSO4, and/or HgS, while 1.0
1.9% of the tags were altered exclusively as a consequence of stimulation with
one of the granuloma-associated agents. Our data provide evidence that this
strategy may function as a preselection for appropriate primer combinations to
discover sequence tags which could be specifically associated with granulomatous
disorders. This approach could shorten laborious screening, save consumption of
valuable and rare samples, and could reduce the number of false-positive results.
PMID- 10682321
TI - Relationship of angiotensin-converting enzyme gene polymorphism to carotid wall
thickness in middle-aged men.
AB - The insertion/deletion (I/D) polymorphism of the human angiotensin-converting
enzyme (ACE) gene is a major determinant of circulating ACE levels. The D allele
has been suggested to be a potent risk factor for coronary artery disease;
however, the effect of the ACE gene on carotid atherosclerosis remains
controversial. We therefore studied the relationship between the ACE gene I/D
polymorphism and carotid artery intima-media thickness (IMT). A random sample of
300 men aged 50-59 years living in southern Finland were selected, and 233 agreed
to participate (74%). Data were collected in 219 subjects. Quantitative B-mode
ultrasonography was used to measure the maximum near and far wall IMT of right
and left common, bifurcation, and internal carotid artery. The mean maximum IMT
(overall mean) was calculated as the mean of 12 maximum IMTs at 12 standard
sites. Patients with an IMT higher than 1.7 mm in at least one of 12 standard
sites were assumed to have carotid atherosclerosis. The I/D polymorphism was
determined by polymerase chain reaction. Overestimation of the frequency of the
DD genotype was eliminated by insertion-specific primer and the inclusion of 5%
dimethylsulfoxide. No significant differences were found in carotid wall
thickness between the three genotypes; the overall mean IMT were 1.18 +/- 0.30,
1.22 +/- 0.24, and 1.08 +/- 0.40 mm in genotypes of II, ID, and DD, respectively.
Similarly, the ACE genotypes and allele frequencies did not differ significantly
between the subjects with and those without carotid atherosclerosis. There was no
association in the subgroups among only nonsmoking subjects or subjects without
chronic medication. The present data indicate that the I/D polymorphism of the
ACE gene is not related to carotid IMT and is unlikely to play a major role in
carotid atherosclerosis.
PMID- 10682322
TI - Efficient gene delivery into adult cardiomyocytes by recombinant Sindbis virus.
AB - Somatic gene therapy as a potential strategy for the treatment of myocardial
diseases relies on an efficient gene transfer into cardiac muscle cells. The
difficulty of delivering genes into adult cardiomyocytes exists not only in vivo
but also in primary culture systems. Therefore, possibilities for ex vivo gene
transfer and the in vitro study of physiological processes by reverse genetics
are limited. We investigated the potential of an alphavirus-based vector system
to transduce adult rat cardiomyocytes (ARC) in culture using a replication
deficient Sindbis virus (SIN) encoding beta-galactosidase (SIN-LacZ).
Transduction efficiency depended on the virus concentration used, with expression
of the reporter gene being detectable in up to 80% of cultured ARC as early as 24
h after infection. We observed a remarkably lower cytotoxicity of this viral
vector in ARC than in other cells such as fibroblasts and neonatal
cardiomyocytes. Additionally, no perceptible changes in the morphology of the
nuclei or cytoskeleton were found in ARC 48 h after infection with SIN-LacZ. We
conclude that SIN vectors are useful for gene delivery into adult cardiomyocytes
and believe that improved versions of this viral system may be useful for
cardiovascular gene therapy in the future.
PMID- 10682324
TI - Dosage schedule for dietary fluoride supplements. Proceedings of a workshop.
Chicago, Illinois, USA. January 31-February 1, 1994.
PMID- 10682323
TI - The expression and role of insulin-like growth factor II in malignant
hemangiopericytomas.
AB - Hemangiopericytoma is a rare soft tissue tumor originating from contractile
pericapillary pericytes. To address the issue of molecular genetic events that
participate in genesis and progression of hemangiopericytoma we analyzed insulin
like growth factor (IGF) II and IGF I receptor in 29 tumors collected from a
human tumor bank network. Seven of these tumors were associated with severe
hypoglycemia; six were retroperitoneal and one was located in the leg. Of 22
tumors tested 12 (54.5%) exhibited IGF II mRNA, while almost 90% (17 of 19) of
hemangiopericytomas exhibited IGF I receptor mRNA. Sera from some patients whose
tumors expressed IGF II mRNA contained elevated levels of IGF II. Removal of the
tumor eliminated most of the IGF II immunoreactivity from the sera. The potential
role of IGF II as a growth-promoting factor was examined on three malignant
primary hemangiopericytoma cell cultures. Extracellular addition of IGF II
significantly enhanced cell proliferation in a dose-dependent manner. Antisense
oligodeoxynucleotides that specifically inhibit IGF II mRNA, at a concentration
of 40 or 80 micrograms/ml, inhibited the growth of hemangiopericytoma cells
significantly, by 40%. Simultaneous administration of antisense
deoxyoligonucleotides to both IGF II and IGF I receptor inhibited tumor cell
proliferation by even 80%. Our data suggest that tumor cells produce IGF II, and
that this in turn stimulates their proliferation by autocrine mechanisms.
PMID- 10682325
TI - The role of dietary fluoride supplements in caries prevention.
AB - Nearly all dental researchers and public health authorities agree that fluoride
supplements are highly effective in reducing dental caries in primary and
permanent teeth, that benefits to all teeth are greater when administration
begins at 2 years of age or younger, that both preeruptive and posteruptive
exposure is important in imparting cariostatic benefits, that effectiveness is
neither enhanced nor reduced by their being combined with vitamins, and that
benefits to the offspring of pregnant women who take supplements are uncertain.
Several studies show that fluoride supplements delivered in school-based programs
effectively reduce dental caries, and benefits are greater to teeth that receive
preeruptive exposure in addition to posteruptive exposure. Many parents who, for
a variety of reasons, did not administer fluoride supplements at home will enroll
their children in school-based fluoride tablet programs. Effectiveness of
fluoride supplements today is undoubtedly smaller than observed previously
because of dilution and diffusion effects from other fluoride sources;
nevertheless, they still have the same potential efficacy. It is apparent that
the current ADA dosage schedule is too high and requires modification; however,
the availability of this known-to-be-effective regimen should not be eliminated
or restricted.
PMID- 10682326
TI - Total fluoride intake and implications for dietary fluoride supplementation.
AB - This paper reviews the history and validity of recommended "optimal" levels of
systemic fluoride intake and the available information on levels of fluoride
intake in young children from foods and beverages (including water), dentifrices,
dietary fluoride supplements, mouthrinses, and gels. Most of the studies
emphasize the substantial variation in ingestion among individuals. Often, a
substantial proportion of individuals received fluoride well beyond the mean
exposure reported in the study. Limitations in the existing data make it
difficult to determine the total distribution of fluoride intake from all
sources. Therefore, hypothetical combinations of possible daily fluoride intake
from the three main sources (diet, dentifrices, and supplements) are presented
for those aged 6, 12, 24, and 36 months, with associated mean intake per kg body
weight. Findings suggest that some children exceed the "optimal" level of
fluoride intake from single sources alone, while others can from a combination of
sources. Moreover, if current recommended "optimal" levels, which have been
derived on an empirical basis, are actually lower than what has been quoted in
the literature, then more children could be ingesting excessive amounts of
fluoride, which could increase their risk of developing objectionable dental
fluorosis. The variation and complexity of fluoride ingestion from all sources
should be considered in the evaluation of recommendations for use of dietary
fluoride supplements.
PMID- 10682327
TI - Fluoride metabolism and excretion in children.
AB - This paper compares fluoride pharmacokinetics (plasma, renal, and extrarenal
clearances) and metabolic balances in healthy infants or children with those in
young or middle-aged adults. Regardless of age, the removal of fluoride from the
intra- and extracellular body fluids occurs almost exclusively by uptake in
calcified tissues and excretion in the urine. While there can be considerable
differences among individuals, the rates at which fluoride is cleared from plasma
by calcified tissues and the kidneys in adults are approximately equal. The
calcified tissue clearance of fluoride from plasma in children is substantially
higher than that by the kidneys. This is due to the greater surface area of the
loosely organized crystallites in the developing calcified tissues during growth.
Thus, the balance of fluoride (total intake minus total excretion) is typically
higher in children than in adults, but it can be positive or negative at any age.
Positive balance occurs when chronic fluoride intake is sufficient to prevent
plasma concentrations from declining. When positive, the fluoride content of the
calcified tissues, which contain more than 99 percent of the body's fluoride,
tends to gradually increase. Negative balance, which indicates net mobilization
of fluoride from calcified tissues, can occur when plasma concentrations decline
due to a reduction in the level of fluoride intake.
PMID- 10682328
TI - Fluoride intake by infants.
AB - Many infants are fully or partially breast fed during the early months of life;
however, the percentage of such infants decreases to about 30 percent by 4 months
of age. The majority of US infants are fed formulas for most of the first 10
months of life. Although fluoride (F) intakes by fully breast-fed infants are
low, F intakes by partially breast-fed infants and by formula-fed infants are
highly variable, depending primarily on the F content of the water used to dilute
concentrated liquid or powdered infant formula products. In communities with F
content of the drinking water less than 0.3 ppm, F consumption by many infants
will be 30 to 40 micrograms.kg-1.d-1. The addition of a F supplement of 0.25 mg/d
for a 4 kg infant would increase the F intake by 63 micrograms.kg-1.d-1,
resulting in a total intake of about 100 micrograms.kg-1.d-1, an intake in the
range believed to be associated with development of fluorosis of the permanent
teeth. However, for the US infant population generally, many fewer infants are
exposed to high F intakes from formula plus a supplement (recommended only for
communities with water providing less than 0.3 ppm F) than from formula alone in
communities with F content of 1 ppm in the drinking water. In assessing the
possible effects of F intake during infancy on development of fluorosis, it is
important to recognize that infant feeding practices have changed greatly during
the past 30 years. In the 1960s, most infants over 4 months of age were fed fresh
cow's milk and intakes of F were therefore low. By the mid 1970s a trend toward
more extended feeding of formula was evident and this trend has continued into
the 1990s. Prolonged exposure to high intakes of fluoride during infancy is much
more common now than in the past.
PMID- 10682329
TI - The differential diagnosis of fluorosis.
AB - Following the introduction of the first fluorosis index by Dean, a series of
fluorosis indexes were introduced. While they may differ in the specific way
fluorosis is categorized, they all nevertheless use the same underlying
diagnostic signs--originally described by Dean, Black, and McKay--that were
causally linked to the development of enamel in areas with above-optimum fluoride
in the drinking water. Underlying the various fluorosis indexes is the belief
that specific clinical diagnostic criteria, based upon established clinical
signs, can be utilized to differentiate fluorotic from nonfluorotic enamel
opacities. These criteria repeatedly have been substantiated in studies in which
the presence of enamel fluorosis, identified by clinical differential diagnosis,
has been associated with fluoride exposure history. Further, to whatever extent
nonfluorotic opacities have been misdiagnosed as fluorosis, observed estimates of
association derived from analytical studies will have been underestimated.
PMID- 10682330
TI - The prevalence and severity of enamel fluorosis in North American children.
AB - The question considered in this review is the extent to which changes in the
prevalence or severity of enamel fluorosis have occurred over the last half
century. Emphasis is given to a review of those studies in which subjects are
drinking water that is fluoride deficient and those in which subjects are
drinking optimally fluoridated water, either adjusted or natural. Trends in
fluorosis were examined using two definitions of fluorosis (definite and any
signs) and three types of comparisons--comparisons of pooled estimates from all
available studies that include data from different communities and time periods,
comparisons of estimates from the same communities at different times, and
comparisons of estimates from selected studies in the early years of fluorosis
research with results of the US National Fluorosis Survey done by the National
Institute of Dental Research. A clear increase in fluorosis among populations
drinking community water that contains less than 0.3 ppm fluoride was found.
Results of the comparisons using studies with Dean's Index pooled at different
time points, comparisons in the same communities over time, and comparisons of
prevalence found in selected communities before fluoride was widely available
with the National Fluorosis Survey all support this conclusion. An increase in
the prevalence of fluorosis in those drinking optimally fluoridated water likely
has occurred as well; however, evidence for such a trend is not as clear as for
fluoride deficient communities because of mixed results depending on the type of
comparison. The majority of fluorosis cases continue to be mild and seem of
little esthetic consequence for most of the public or dental profession. But a
few cases of more severe fluorosis can be found now in some communities. Because
the prevalence of fluorosis is now higher than 50 years ago, we can conclude that
fluoride availability to the developing enamel during critical periods when
enamel is at risk of fluorosis has increased in North American children.
PMID- 10682331
TI - Mechanism and timing of fluoride effects on developing enamel.
AB - Fluoride appears to specifically interact with mineralizing tissues, causing an
alteration of the mineralization process. In enamel, fluorosis results in a
subsurface hypomineralization. This hypomineralized enamel appears to be directly
related to a delay in the removal of amelogenins at the early-maturation stage of
enamel formation. The specific cause for this delay is not known, although
existing evidence points to reduced proteolytic activity of proteinases that
hydrolyze amelogenin. This delay in hydrolysis of amelogenins could be due to a
direct effect of fluoride on proteinase secretion or proteolytic activity, or to
a reduced effectiveness of the proteinase due to other changes in the protein or
mineral of the fluorosed enamel matrix. The formation of dental fluorosis is
highly dependent on the dose, duration, and timing of fluoride exposure. The
early-maturation stage of enamel formation appears to be particularly sensitive
to the effects of fluoride on enamel formation. Although the risk of enamel
fluorosis is minimal with exposure only during the secretory stage, this risk is
greatest when exposure occurs in both secretory and maturation stages of enamel
formation. The risk of fluorosis appears to be best related to the total
cumulative fluoride exposure to the developing dentition.
PMID- 10682332
TI - Overview of the history and current status of fluoride supplementation schedules.
AB - Clinical trials of dietary fluoride supplements began in the 1940s in an effort
to bring the benefits of fluoride to those who did not receive it through their
drinking water. Following the early success of these trials, the Council on
Dental Therapeutics of the American Dental Association (ADA) published its first
recommendations for fluoride supplementation in 1958. The American Academy of
Pediatrics (AAP) followed with its own recommendations in 1972. During the 1970s
a variety of alternative schedules appeared in the literature, most in reaction
to the findings of unexpectedly high levels of enamel fluorosis in children being
supplemented with the AAP schedule. In 1979 the ADA and AAP agreed on essentially
identical schedules. During the 1980s, however, the prevalence of enamel
fluorosis continued to increase, and fluoride supplements were found in some
studies to be a risk factor for fluorosis. This finding prompted another round of
dosage schedule recommendations in the early 1990s. This paper presents a history
of fluoride dosage recommendations and reviews the recent proposals for reducing
supplement dosage.
PMID- 10682333
TI - The case for retaining the current supplementation schedule.
AB - Following ingestion of dietary fluoride, microquantities of fluoride return to
the mouth in saliva, but in quantities large enough to facilitate the maintenance
and reparative functions of enamel. Dietary fluoride supplements alone are
unlikely to be the cause of the reported increase in fluorosis. Compliance
continues to be extremely poor and few children use supplements for more than a
year and a half. The amount of background fluoride resulting from dietary
fluoride supplements appears to be very small. Considering the almost ubiquitous
presence of fluoride dentifrice and the strong possibility of additional
unintentional fluoride ingestion from many sources, the present fluorosis data is
too amorphous to use as a basis for making reasonable risk/benefit evaluations.
Very mild and mild fluorosis is not a serious problem for either the clinician or
the patient. By altering the present recommended dosage we may deprive children
from receiving a proven effective dose. One cannot make a risk/benefit decision
concerning an esthetic problem without involving the patient's perception as well
as the caries score. The apparent severity of the milder forms of fluorosis
lessens with age and a community fluorosis index should be used only on
populations who are older than 15 years.
PMID- 10682334
TI - The case for reducing the current Council on Dental Therapeutics fluoride
supplementation schedule.
AB - The milder forms of dental fluorosis have increased in prevalence since the
original epidemiologic surveys of the 1930s. Most studies of fluorosis have
identified the use of supplements as a major risk factor. Fluorosis could be
prevented, in part, by stopping the improper prescription of fluoride supplements
in optimally fluoridated areas and by lowering the dosage currently recommended
by the Council on Dental Therapeutics supplemental fluoride schedule. At a 1991
workshop at the University of North Carolina, five alternatives to the present
ADA Council on Dental Therapeutics schedule were suggested; however, no consensus
on dosage was reached. Recently, the Federation Dentaire International adopted a
dosage schedule of 0.25 mg F from birth to 3 years of age, 0.5 mg F from 3 to 5
years, and 1 mg F thereafter. At a 1992 Canadian workshop it was proposed that
supplements should not be started until age 3, should be given only to those "at
high risk" of caries, and only 0.25 mg F should be prescribed from 3 to 5 years
of age. Similarly, in some European countries supplements are not recommended
until 3 years, at which time 0.5 mg F is prescribed, but only "for children at
risk." Australia is considering a dosage schedule starting with 0.25 mg F at 6
months, again only for those "particularly at risk of caries." Serious problems
exist in limiting fluoride supplementation only to high-caries-risk children
because they are not easily identifiable at a young age. Ideally, a dosage
schedule should be based on body surface area or weight rather than simply age,
and supplements should be in the form of lozenges for children over 2 years of
age. A reduced fluoride supplement dosage schedule is proposed.
PMID- 10682335
TI - The case for eliminating the use of dietary fluoride supplements for young
children.
AB - Fluoride supplements have been used for years to prevent dental caries;
nevertheless, there are three reasons why their use is inappropriate today among
infants and young children in the United States. Evidence for the efficacy of
fluoride supplements when used from birth or soon after is weak, supplements are
a risk factor for dental fluorosis, and fluoride has little preeruptive effect in
caries prevention. While there are many reports on the caries-preventive efficacy
of supplements, few meet standards for acceptability as clinical trials, and
those that do have tested chewable tablets or lozenges under supervision in
school-aged children. North American children today are exposed to fluoride from
many sources--drinking water, toothpaste, gels, rinses, and in processed foods
and beverages. The additional cariostatic benefits that accrue from using
supplements are marginal at best, while there is strong risk of fluorosis when
young children use supplements. Available evidence suggests that the public is
more aware of the milder forms of fluorosis than was previously thought; thus, it
is prudent for caries-preventive policies to aim to maximizing caries reductions
while minimizing the risk of fluorosis. It is therefore concluded that the risks
of using supplements in infants and young children outweigh the benefits. Because
alternative forms of fluoride for high-risk individuals exist, fluoride
supplements should no longer be used for young children in North America.
PMID- 10682336
TI - Challenges of and strategies for changing prescribing practices of health care
providers.
AB - Problems related to inappropriate prescribing practices of physicians in general
are well recognized. Dietary fluoride supplements have been implicated as one of
the contributing factors in an increase in dental fluorosis. Inappropriate
prescribing practices of providers have been cited as a major factor in this
implication. Numerous studies of physicians and dentists have documented a lack
of knowledge and inappropriate prescribing practices regarding fluoride
supplements. The purpose of this paper is to identify barriers to changing
fluoride-prescribing practices of health care providers and to suggest strategies
for implementing change. To increase optimal and appropriate use of fluoride
supplements, educational interventions are necessary for all user groups--detail
men and women, physicians, dentists, pharmacists, nurse practitioners, dental
hygienists, and the public. In addition, environmental supports for the
educational activities in the form of policy, regulation, standards of care, and
guidelines are recommended for consideration.
PMID- 10682337
TI - Testing for symmetry in the conditional discriminations of language-trained
chimpanzees.
AB - If subjects are taught to match Stimulus A to B and then, without further
training, match B to A, they have passed a test of symmetry. It has been
suggested that non-humans' lack of success on symmetry tests might be overcome by
giving them a history of symmetry exemplar training, that is, by directly
teaching a large number of conditional relations (e.g., AB, CD, EF,...) and also
directly training the "reverse" of these relations (e.g., BA, DC, FE,...). The
chimpanzee subjects of the present study, Sherman, Austin, and Lana, had already
received extensive symmetry exemplar training as a result of attempts to teach a
selection-based language system of lexigrams. The present study systematically
subjected 2 of these chimps (Sherman and Lana), for the first time, to standard
symmetry tests in controlled conditions. Both chimps failed the tests, even when
their correct responses on test trials were reinforced. The findings do not
support the exemplar training hypothesis, and cast doubt upon whether the chimps
can pass tests of stimulus equivalence.
PMID- 10682338
TI - Falsification of matching theory's account of single-alternative responding:
Herrnstein's k varies with sucrose concentration.
AB - Eight rats pressed levers for varying concentrations of sucrose in water under
eight variable-interval schedules that specified a wide range of reinforcement
rate. Herrnstein's (1970) hyperbolic equation described the relation between
reinforcement and responding well. Although the y asymptote, k, of the hyperbola
appeared roughly constant over conditions that approximated conditions used by
Heyman and Monaghan (1994), k varied when lower concentration solutions were
included. Advances in matching theory that reflect asymmetries between response
alternatives and insensitive responding were incorporated into Herrnstein's
equation. After fitting the modified equation to the data, Herrnstein's k also
increased. The results suggest that variation in k can be detected under a
sufficiently wide range of reinforcer magnitudes, and they also suggest that
matching theory's account of response strength is false. The results support
qualitative predictions made by linear system theory.
PMID- 10682339
TI - Three predictions of the economic concept of unit price in a choice context.
AB - Economic theory makes three predictions about consumption and response output in
a choice situation: (a) When plotted on logarithmic coordinates, total
consumption (i.e., summed across concurrent sources of reinforcement) should be a
positively decelerating function, and total response output should be a bitonic
function of unit price increases; (b) total consumption and response output
should be determined by the value of the unit price ratio, independent of its
cost and benefit components; and (c) when a reinforcer is available at the same
unit price across all sources of reinforcement, consumption should be equal
between these sources. These predictions were assessed in human cigarette smokers
who earned cigarette puffs in a two-choice situation at a range of unit prices.
In some sessions, smokers chose between different amounts of puffs, both
available at identical unit prices. Individual subjects' data supported the first
two predictions but failed to support the third. Instead, at low unit prices, the
relatively larger reinforcer (and larger response requirement) was preferred,
whereas at high unit prices, the smaller reinforcer (and smaller response
requirement) was preferred. An expansion of unit price is proposed in which
handling costs and the discounted value of reinforcers available according to
ratio schedules are incorporated.
PMID- 10682340
TI - Travel time and concurrent-schedule choice: retrospective versus prospective
control.
AB - Six pigeons were trained on concurrent variable-interval schedules in which two
different travel times between alternatives, 4.5 and 0.5 s, were randomly
arranged. In Part 1, the next travel time was signaled while the subjects were
responding on each alternative. Generalized matching analyses of performance in
the presence of the two travel-time signals showed significantly higher response
and time sensitivity when the longer travel time was signaled compared to when
the shorter time was signaled. When the data were analyzed as a function of the
previous travel time, there were no differences in sensitivity. Dwell times on
the alternatives were consistently longer in the presence of the stimulus that
signaled the longer travel time than they were in the presence of the stimulus
that signaled the shorter travel time. These results are in accord with a recent
quantitative account of the effects of travel time. In Part 2, no signals
indicating the next travel time were given. When these data were analyzed as a
function of the previous travel time, time-allocation sensitivity after the 4.5-s
travel time was significantly greater than that after the 0.5-s travel time, but
no such difference was found for response allocation. Dwell times were also
longer when the previous travel time had been longer.
PMID- 10682341
TI - Choice between constant and variable alternatives by rats: effects of different
reinforcer amounts and energy budgets.
AB - Two experiments, using rats as subjects, investigated the effect of different
reinforcer amounts and energy budgets on choice between constant and variable
alternatives under a closed economy. Rats were housed in the chamber and were
exposed to a modified concurrent-chains schedule in which the choice phase was
separated from a rest phase during which the rats could engage in other
activities. In the choice phase, a single variable-interval schedule arranged
entry into one of two equal terminal links (fixed-interval schedules). The
constant terminal link ended with the delivery of a fixed number of food pellets
(two or three, depending on the condition), whereas the variable terminal link
ended with a variable number of food pellets (means of two or three, depending on
the condition). Energy budget was defined as positive when body weights were over
90% of free-feeding weights, and as negative when they were under 80% of free
feeding weights. The different body weights were produced by varying the duration
of the equal terminal-link schedules within daily 3-hr sessions. In Experiment 1,
rats chose between a constant and a variable three pellets under both energy
budgets. Rats preferred the constant three pellets more under the positive energy
budget, whereas they were indifferent under the negative energy budget. In
Experiment 2, rats chose between a constant three pellets and a variable two
pellets, and chose between a constant two pellets and a variable three pellets
under both energy budgets. The rats strongly preferred the constant three pellets
over the variable two pellets under both energy budgets. In contrast, rats
preferred the variable three pellets over the constant two pellets only under the
negative energy budget, whereas they were indifferent under the positive energy
budget. These results indicate that rats choices are sensitive to the difference
in reinforcer amounts and to the energy budgets defined by the level of body
weight. The present results are consistent with those obtained with small
granivorous birds as well as with the predictions of a recent risk-sensitive
foraging theory.
PMID- 10682342
TI - Pigeons' choices between fixed-ratio and linear or geometric escalating
schedules.
AB - Four related procedures provided a basis for comparing the linear-optimality
principle with a principle based on the sums of reciprocals of distances to
reinforcement, and to explore the generality of the sums-of-reciprocals principle
as a description of choice patterns in situations of diminishing returns. The
procedures all arranged choices between fixed-ratio schedules and progressive
ratio schedules, which escalated with each consecutive choice. In contrast to
previous work that involved constant ratio increments, two sets of procedures in
this study involved relatively small increments that are similar to the early
values when a progressive schedule is increasing proportionally. The remaining
two sets of procedures examined progressive schedules with proportional
increments. In addition, the initial value of the progressive alternative was
manipulated to determine its effects on patterns of choice with both linear and
proportional types of escalation. With the exception of one phase, regardless of
the initial/reset value and the patterns of escalation, patterns of choice with
pigeons were well characterized by the sums-of-reciprocals principle. This
supports previous research with pigeons using fixed-increment progressive
schedules, as well as situations in which the progressive schedule increased by
constant proportions instead of by constant increments. The findings are
attributed to the feature of this averaging technique whereby it differentially
values reinforcers based on their relative proximity to a particular choice
point.
PMID- 10682343
TI - Drug discrimination in rats under concurrent variable-interval variable-interval
schedules.
AB - Eight rats were trained to discriminate pentobarbital from saline under a
concurrent variable-interval (VI) VI schedule, on which responses on the
pentobarbital-biased lever after pentobarbital were reinforced under VI 20 s and
responses on the saline-biased lever were reinforced under VI 80 s. After saline,
the reinforcement contingencies programmed on the two levers were reversed. The
rats made 62.3% of their responses on the pentobarbital-biased lever after
pentobarbital and 72.2% on the saline-biased lever after saline, both of which
are lower than predicted by the matching law. When the schedule was changed to
concurrent VI 50 s VI 50 s for test sessions with saline and the training dose of
pentobarbital, responding on the pentobarbital-biased lever after the training
dose of pentobarbital and on the saline-biased lever after saline became nearly
equal, even during the first 2 min of the session, suggesting that the presence
or absence of the training drug was exerting minimal control over responding and
making the determination of dose-effect relations of drugs difficult to
interpret. When the pentobarbital dose-response curve was determined under the
concurrent VI 50-s VI 50-s schedule, responding was fairly evenly distributed on
both levers for most rats. Therefore, 6 additional rats were trained to respond
under a concurrent VI 60-s VI 240-s schedule. Under this schedule, the rats made
62.6% of their responses on the pentobarbital-biased lever after pentobarbital
and 73.5% of their responses on the saline-biased lever after saline, which also
is lower than the percentages predicted by perfect matching. When the schedule
was changed to a concurrent VI 150-s VI 150-s schedule for 5-min test sessions
with additional drugs, the presence or absence of pentobarbital continued to
control responding in most rats, and it was possible to generate graded dose
response curves for pentobarbital and other drugs using the data from these 5-min
sessions. The dose-response curves generated under these conditions were similar
to the dose-response curves generated using other reinforcement schedules and
other species.
PMID- 10682344
TI - Highly purified thermo-stable oxygen-evolving photosystem II core complex from
the thermophilic cyanobacterium Synechococcus elongatus having His-tagged CP43.
AB - The carboxyl terminus of the CP43 subunit of photosystem II (PSII) in the
thermophilic cyanobacterium, Synechococcus elongatus, was genetically tagged with
six consecutive histidine residues to create a metal binding site on the PSII
supramolecular complex. The histidine-tagging enabled rapid isolation of an
intact cyanobacterial PSII core complex from dodecyl maltoside-solubilized
thylakoids by a simple one-step Ni(2+)-affinity column chromatography. The
isolated core complex was in a dimeric form with a molecular mass of about 580
kDa, consisting of five major intrinsic membrane proteins (CP47, CP43, D1, D2 and
cytochrome b-559), three extrinsic proteins (33 kDa, 12 kDa, and cytochrome c
550), and a few low molecular mass membrane proteins, and evolved oxygen at a
rate as high as 3,400 mumol (mg Chl)-1 h-1 at 45 degrees C with ferricyanide as
an electron acceptor. The core complex emitted thermoluminescence B2-, B1- and Q
bands arising from S2QB-, S3QB- and S2QA- charge recombinations at respective
emission temperatures of 45, 38 and 20 degrees C, all of which were higher by
about 15 degrees C as compared with those in mesophilic spinach BBY membranes.
These results indicated that the isolated core complex well retained the intact
properties of thermoluminescence of thermophilic cyanobacterial cells, the deeper
stabilization of PSII charge pairs. The isolated complex was extremely stable in
terms of both protein composition and function, exhibiting no release of
extrinsic proteins, no proteolytic degradation in any of its subunits,
accompanied by only a slight (less than 10%) loss in oxygen evolution, after dark
incubation at 20 degrees C for 8 d. These properties of the thermophilic PSII
core complex are highly useful for various types of studies on PSII.
PMID- 10682345
TI - Molecular cloning of a defense-response-related cytochrome P450 gene from
tobacco.
AB - Plant defenses against pathogen attack involve a series of inducible responses
that contribute to resistance. Tobacco leaves injected with HWC (hyphal wall
components prepared from Phytophthora infestans) elicitor showed typical defense
responses, including the induction of localized necrosis and the accumulation of
pathogenesis-related proteins. In order to elucidate the molecular mechanisms by
which plant defense systems are activated, we screened tobacco plants for genes
differentially expressed in response to HWC. We performed differential screening
by RT-PCR with random primers and obtained PCR products specific to HWC-treated
leaf RNA. Northern hybridization using the PCR products as probes confirmed that
one transcript was actually induced by HWC treatment. As the deduced amino acid
sequence of this clone showed the highest degree of similarity to elicitor
induced soybean cytochrome P450 CYP82A4, it was designated CYP82E1. The
expression of CYP82E1 was strongly induced in tobacco by the soybean pathogen
Pseudomonas syringae pv. glycinea (nonpathogenic on tobacco), but it was
activated only slightly and in a delayed fashion by the tobacco pathogen P.
syringae pv. tabaci (pathogenic on tobacco), implying that the product of CYP82E1
may be involved in disease resistance in tobacco.
PMID- 10682346
TI - Localization of the Ca(2+)-binding protein, Bra r 1, in anthers and pollen tubes.
AB - Calcium plays an essential role during pollen development and pollen tube growth,
and several Ca(2+)-binding proteins are expressed in anthers. We have previously
reported that Brassica pollen allergens encoded by Bra r 1 and Bra r 2 show
sequence similarities to Ca(2+)-binding proteins [Toriyama et al. (1995) Plant
Mol. Biol. 29: 1157]. Herein, we report that both genes are expressed in the
diploid tapetum and haploid microspores, as detected by in situ RNA
hybridization. Immunoblot analysis revealed that Bra r 1 and Bra r 2 were
accumulated in anthers during pollen development. When pollen grains were
suspended in an aqueous solution, both proteins were mainly detected in the
pollen extracellular fraction, indicating that Bra r 1 and Bra r 2 are released
from the pollen upon hydration. Localization of Bra r 1 was further investigated
in sections of anthers and pollen tubes. Bra r 1 was detected in the tapetum,
microspores and pollen grains. In longitudinal sections of cross-pollinated
pistils. Bra r 1 was detected throughout pollen tubes elongating in transmitting
tissue. These findings suggest that Bra r 1 may be involved in pollen-pistil
interaction and pollen tube growth.
PMID- 10682347
TI - Developmental transitions and dynamics of the cortical ER of Arabidopsis cells
seen with green fluorescent protein.
AB - Arabidopsis thaliana plants were stably transformed with DNA encoding green
fluorescent protein and with sequences ensuring retention in the endoplasmic
reticulum (ER). Confocal laser scanning microscopy shows fluorescent ER in many
cells of seedlings so allowing developmental changes to be documented. The
arrangement of the cortical ER changes as cells mature in the hypocotyl and root
epidermis. In the root, cells that have completed expansion have reticulate
cortical ER resembling the ER described in many previous studies. Expanding
cells, however, show extensive perforated sheets of cortical ER which transform
quite abruptly into a loose reticulum at the basipetal end of the elongation
zone. The reticulum compacts in trichoblasts beginning at sites where root hairs
are about to emerge. The compacted form is maintained throughout the hair until
growth ceases and the open reticulate form returns. All forms of cortical ER are
dynamic and we use a color overlay method to distinguish stable and moving
structures in a single composite image. Reticulate ER continuously rearranges its
polygonal layout and perforations move and change their shape in the ER sheets of
younger cells. ER deeper in the cell (i.e. not close to the plasma membrane)
moves more actively so that almost no tubules remain stable even over short
periods of less than one minute. The function of the perforated sheets of
cortical ER present in growing cells is unknown.
PMID- 10682348
TI - Identification and expression of cotton (Gossypium hirsutum L.) plastidial
carbonic anhydrase.
AB - Four carbonic anhydrase (CA) cDNA clones were isolated from a 48 h dark-grown
cotton (Gossypium hirsutum L.) seedling cDNA library. Nucleotide sequence
analysis revealed two different CA isoforms designated GhCA1 and GhCA2. The
encoded polypeptides possess N-terminal serine/threonine-rich regions indicative
of plastid transit peptides, and approximately 80% sequence identity to other
plant plastidial beta-CAs. The GhCA1 cDNA encodes a nearly complete preprotein of
323 amino acids with a molecular mass of 34.9 kDa and a predicted mature protein
of 224 amino acids with a molecular mass of 24.3 kDa. Eleven nucleotide
differences within ORFs of GhCA1 and GhCA2 result in 5 conservative amino acid
substitutions. The 3' GhCA2 untranslated region contains five additional
substitutions and one single nucleotide addition. GhCA1 clones, nearly full
length or with 70% of the transit peptide deleted, were expressed as LacZ alpha
fusion proteins in E. coli. Lysates of these strains contained 9-fold higher
levels of CA activity as compared to untransformed controls and this activity was
inhibited by CA-specific inhibitors. Sulfanilamide, acetazolamide,
ethoxyzolamide, each at 10 mM, inhibited recombinant CA activity approximately
50%, 65%, and 75%, respectively. In plant tissue homogenates these inhibitors
reduced CA activity by 50%, 70%, and 95%, respectively. Although CA activity was
bighest in extracts of mature cotton leaves, probing total RNA with GhCA1
revealed CA transcript levels to be highest in the cotyledons of dark-grown
cotton seedlings. Collectively, our data indicate the presence of a plastid
localized CA in cotyledons of germinated seeds, suggesting a role for CA in
postgerminative growth.
PMID- 10682349
TI - Characterization of a flower-specific gene encoding a putative myrosinase binding
protein in Arabidopsis thaliana.
AB - A cDNA clone, 4B-1, previously isolated by differential screening is
preferentially expressed in floral organs of Arabidopsis thaliana.
Characterization of the full length cDNA and the genetic locus corresponding to
4B-1 cDNA revealed that it potentially encodes a myrosinase binding protein (MBP)
which is presumably present in a large myrosinase complex. The deduced amino acid
sequence of the polypeptide encoded by cDNA clone (designated f-AtMBP) appeared
to consist of two parts: one region at the C-terminal half representing overall
homology with AtMBP, an MBP homologue in A. thaliana, and the other at an
extended N-terminal region of about 150 amino acids showing significant identity
with the N-terminal region of the MBP-related protein reported in Brassica.
Expression analysis by RNA blot and in situ hybridization showed that f-AtMBP was
specifically expressed in floral meristems, pistils, stamens, petals, and ovules
of immature flowers, but no expression was observed in the specialized cells
called the myrosin cells in the hypocotyl and cotyledons of developing seeds
where myrosinase enzymes are normally found. Although MBPs and MBP-related
proteins are considered to be inducible by exogenous application of signal
molecules and physical wounding, we found that f-AtMBP expression was not
activated by such treatment, suggesting that f-AtMBP is a novel type of MBP
specific to floral organs.
PMID- 10682351
TI - Contaminants in the Greenland environment.
PMID- 10682350
TI - Characterization of mitochondria-located small heat shock protein from tomato
(Lycopersicon esculentum).
AB - We cloned and sequenced a full-length cDNA encoding the precursor of the
mitochondria-located small heat shock protein (MT-sHSP) gene (LeHSP23.8) from
tomato (Lycopersicon esculentum). The deduced protein precursor with a calculated
molecular weight of 23.8 kDa was predicted to target mitochondria and was
classified as a plant MT-sHSP. A single copy of LeHSP23.8 was found in tomato
genomic DNA by southern-blot analysis. Northern-blot analysis revealed the heat
inducible character of LeHSP23.8 mRNA. The LeHSP23.8 mRNA was hardly detectable
at about 36 degrees C but accumulated markedly at 40 degrees C. The molecular
chaperone function of LeHSP23.8 was confirmed in vitro. The recombinant LeHSP23.8
was able to enhance the renaturation of chemically denatured citrate synthase
(CS). Moreover, the recombinant LeHSP23.8 protected CS from thermal inactivation
and also promoted the renaturation of thermally inactivated citrate synthase.
PMID- 10682352
TI - Lead, cadmium, mercury and selenium in Greenland marine biota and sediments
during AMAP phase 1.
AB - Lead, cadmium, mercury and selenium levels in the Greenland marine environment
from the first phase of the AMAP are presented. Samples were collected in 1994
1995 covering four widely separated regions in Greenland. Samples included
sediments, soft tissue of blue mussel; and liver of polar cod, shorthorn sculpin,
glaucous gull, Iceland gull and ringed seal. Concentrations of lead were found to
increase with the size of blue mussel, but not with the age of gulls or ringed
seal. Both cadmium and mercury concentrations were found to increase with the
size/age of all species. Selenium concentrations decreased with increasing size
of blue mussel, but increased with the age of gulls and ringed seal. Element
levels found are within the range of those found in previous studies in
Greenland. Relative to global background levels, lead levels must be considered
low, whereas levels of cadmium, mercury and selenium in Greenland marine biota
are high. Significant differences in element levels in sediments and biota among
regions in Greenland were seen in several cases. There was a tendency for the
highest lead and mercury concentrations to be found in east Greenland, whereas
the highest cadmium concentrations were found in central west Greenland. However,
the geographical differences among the media did not show a consistent pattern.
PMID- 10682353
TI - An assessment of selenium to mercury in Greenland marine animals.
AB - Information on mercury and selenium molar relation in muscle, liver and kidney
tissue of Greenland marine animals is presented. In the majority of the samples
selenium was present in a molar surplus to mercury. This was most clear in
molluscs, crustaceans, fish and seabirds. A 1:1 molar ratio was found in tissues
of marine mammals with high mercury concentrations (above approx. 10 nmol/g).
This was most clearly demonstrated for liver and kidney tissue of polar bear and
for ringed seal with high mercury concentration in the liver. These findings
support previous results found in liver tissue of marine mammals, suggesting that
methyl mercury is detoxified by a chemical mechanism involving selenium. If the
anthropogenic release of mercury to the environment increases in the future due
to increasing energy demands, species such as polar bears and seals with high
tissue mercury concentrations should be monitored to elucidate whether this
protective mechanism can be maintained in target organs.
PMID- 10682354
TI - Geographical differences of zinc, cadmium, mercury and selenium in polar bears
(Ursus maritimus) from Greenland.
AB - Muscle, liver, and kidney tissues from 100 polar bears (Ursus maritimus), caught
in the Avanersuaq area, north-west Greenland, and Ittoqqortoormiit area, central
east Greenland, were analysed for zinc, cadmium, mercury and selenium. The zinc
concentrations in muscle and liver were higher than in kidney. Mean zinc
concentrations ranged from 19.7 to 76.0 micrograms/g (all data are presented as
geometric means on a wet wt. basis). The presented cadmium concentrations by area
and age groups were all low in muscle and in many cases below the detection limit
(range: < 0.015-0.048 microgram/g). Cadmium concentrations were intermediate in
liver (range: 0.120-1.98 micrograms/g) and highest in kidney tissue (range: 2.16
28.9 micrograms/g). Mercury was likewise lowest in muscle tissue (range: 0.034
0.191 microgram/g). Mercury concentration ranged quite similarly in liver and
kidney tissue (liver range: 2.13-22.0 micrograms/g; kidney range: 2.87-32.0
micrograms/g). The selenium concentration increased from muscle (range: < 0.2
0.452 microgram/g) over liver (range: 1.20-9.80 micrograms/g) to kidney (range:
2.34-13.9 micrograms/g). No age accumulation was found for zinc. A weak increase
was found for selenium, whereas cadmium and mercury clearly accumulated with age.
An exception was mercury concentrations in muscle tissue, where no clear pattern
was observed. Polar bears had significantly lower cadmium concentrations than
ringed seals from the same area in all three tissues. Likewise mercury was
significantly lower in the muscle tissue of polar bears than in ringed seals,
whereas liver and kidney concentrations were higher. Biomagnification factors are
provided for different tissues and age groups. Tissue ratios are given for
different age groups and metals to enable a rough extrapolation from one tissue
to another. Tissue ratios for cadmium, selenium and for mercury vary up to a
factor of 6 with age. No significant differences could be detected between the
elements analysed in bears from two management zones in north-west Greenland.
This finding is in agreement with the genetic pattern in the two areas. In
central-east Greenland, however, cadmium, selenium, and some of the mercury
concentrations in polar bears from the southern area were higher than from the
northern area, indicating that the east Greenland area represents two different
ecological regions with different polar bear populations. Geographical
differences between polar bears from north-west and east Greenland were only
found for mercury and cadmium in liver tissue, where the concentrations were
highest in bears from north-west Greenland. The geographical trend of increasing
cadmium concentrations in polar bear liver tissue from west to east, which has
been found previously in Canada, could be extended to cover north-west Greenland
as well. East of this region a decrease was found. Mercury concentrations in
polar bear liver tissue showed an increase from Svalbard over east and north-west
Greenland, peaking in bears from south-west Melville Island. A marked decrease
was found west of Melville Island, and the lowest concentrations were found in
the Chukchi Sea.
PMID- 10682355
TI - Temporal trends of cadmium and mercury in Greenland marine biota.
AB - Data for cadmium and mercury in Greenland marine biota (blue mussels, polar cod,
shorthorn sculpin, glaucous gull and ringed seals) over a period of 20 years has
been analysed in order to assess temporal changes. Most of the comparisons were
conducted between tissue samples collected in the mid-1980s and mid-1990s.
Cadmium data from a few time series obtained at reference sites during monitoring
of mining activities were also included. No overall temporal trends in cadmium or
mercury concentrations were found within the 20-year period assessed. However,
cadmium concentrations in ringed seals tended to increase in the period from late
1970s to the mid-1980s. From the mid-1980s to the mid-1990s cadmium
concentrations in ringed seals decreased again, whilst mercury concentrations
showed a tendency to increase in the same period. The observed changes may
reflect natural fluctuations caused by factors such as a shift in feeding
behaviour, rather than changes in anthropogenic exposure.
PMID- 10682356
TI - Mercury in dated Greenland marine sediments.
AB - Twenty marine sediment cores from Greenland were analyzed for mercury, and dated
by the lead-210 method. In general the cores exhibit a mercury profile with
higher mercury concentrations in the upper centimetres of the core. The cores
were studied by linear regression of in Hg vs. age of the sediment for the
youngest 100 years. As a rule the mercury decreased with depth in the sediment
with various degrees of significance. The increase of the mercury flux during the
last 100 years is roughly a doubling. The increase may be of anthropogenic origin
as it is restricted to the last 100 years. In four cores the concentration of
manganese was found also to increase in the top layers indicating diagenesis. In
the other cases the higher concentrations were not accompanied by higher
manganese concentrations. The mercury flux to the sediment surface was generally
proportional to the Pb-210 flux indicating that the mercury mainly originates
from atmospheric washout. But the large variability indicates that other
processes also influence the mercury flux to Arctic marine sediments.
PMID- 10682357
TI - Temporal and spatial trends of persistent organochlorines in Greenland walrus
(Odobenus rosmarus rosmarus).
AB - Persistent organochlorines [PCBs, DDT and chlordane related compounds, dieldrin,
toxaphene, hexachlorocyclohexane (HCH), chlorobenzenes] were determined in
blubber of Atlantic walrus (Odobenus rosmarus rosmarus) in 1978 and 1988 from the
Avanersuaq (Thule) region of north-west Greenland and in 1989 from
Ittoqqortoormiit (Scoresbysund) in east Greenland. Lowest concentrations of
organochlorines (OCs) were found in the samples from the Avanersuaq region while
much higher levels of all compounds, except HCH isomers and
mono/dichlorobiphenyls (CB5/8), were observed in samples (all males) from
Ittoqqortoormiit. Total PCBs (sigma PCB) averaged 246 ng/g (wet wt.) male walrus
from Avanersuaq and 2860 ng/g in samples from Ittoqqortoormiit. DDT isomers
showed the greatest difference between the two locations, 50 x for p,p'-DDE and
69 x higher for p,p'-DDT. Ittoqqortoormiit walrus showed the pattern of OCs
characteristic of seal-eating animals although the consumption of other organisms
cannot be ruled out. The higher levels of OCs in east Greenland compared to north
west Greenland animals were consistent with results for polar bears, seals and
gulls from the same regions. Principal components analysis showed that the
pattern of OCs in Ittoqqortoormiit walrus was very similar to that in walrus from
Inukjuaq in east Hudson Bay, which have previously been reported to be seal
eaters, and quite distinct from the Avanersuaq walrus. No significant differences
in mean concentrations of any OCs were found between male walrus from 1978 and
1988. For females, there were significantly higher levels of CB5/8,
trichlorobiphenyls, dieldrin, toxaphene and alpha HCH as well as sigma HCH but
not for sigma PCBs or DDT compounds. The data for Greenland walrus from the 1970s
and late 1980s provide a baseline for future trend monitoring in walrus.
PMID- 10682358
TI - Organochlorines in Greenland marine fish, mussels and sediments.
AB - Shorthorn sculpin (Myoxocephalus scorpius), polar cod (Boreogadus saida), blue
mussels (Mytilus edulis) and sediments were sampled in Greenland 1994-1995 at
three locations at the west coast and one at the east coast. Fish liver, mussel
soft tissue and sediments were analysed for PCBs (10 congeners), DDTs (pp,'),
HCHs (alpha, beta, gamma), HCB and trans-nonachlor. The overall geometric mean
concentrations found for PCBs were 17 micrograms kg-1 wet wt. in shorthorn
sculpin liver, 33 micrograms kg-1 wet wt. in polar cod liver, and 0.86 microgram
kg-1 wet wt. in blue mussels. For the three species, the geometric mean
concentrations for DDTs were 11, 36, and 0.39 micrograms kg-1 wet wt.,
respectively; for HCHs: 8.7, 32 and 0.56 micrograms kg-1 wet wt., respectively;
for HCB: 4.2, 11 and 0.06 micrograms kg-1 wet wt., respectively; and for trans
nonachlor: 6.3, 19 and 0.16 microgram kg-1 wet wt., respectively. All
organochlorines in the sediment samples were below the detection limit of 0.1
microgram kg-1 dry weight. For sculpins and mussels, most organochlorine
compounds were found to increase with increasing lipid content. The weight of
mussels did not influence organochlorine concentrations, whereas organochlorine
content in general increased with fish length of sculpins. The concentrations
were found to be comparable to levels in other Arctic regions, but orders of
magnitude lower than levels found in the southern part of the North Sea.
Organochlorine concentrations in sculpins showed a decreasing trend following the
ocean current flowing from north to south at the east coast and from south
towards north at the west coast of Greenland. The proportion of higher
chlorinated PCBs (Cl atoms > or = 6) in sculpin liver followed the decreasing
trend of PCB concentrations.
PMID- 10682359
TI - Organochlorines in Greenland ringed seals (Phoca hispida).
AB - Twenty-five ringed seals (Phoca hispida) were sampled in 1994 at each of four
areas in Greenland, three on the west coast and one on the east coast. Seal
blubber samples were analysed for polychlorinated biphenyls (PCBs, IUPAC Nos. 28,
31, 52, 101, 105, 118, 138, 153, 156 and 180), DDTs (p,p'-DDE, p,p'-DDD, p,p'
DDT), hexachlorocyclohexanes (alpha-, beta- and gamma-HCH), hexachlorobenzene
(HCB) and trans-nonachlor. A number of the seals (n = 56) were also analysed for
toxaphene (total toxaphene and single congeners: CHB Nos. 26, 32, 50 and 62). The
overall geometric means (and ranges) found in seals were in microgram kg-1 wet
wt. for sigma PCBs: 452 (85-4200), sigma DDTs: 607 (97-6040), sigma HCHs: 123 (51
382), HCB: 13 (3-27), trans-nonachlor: 83 (21-1236) and total toxaphene: 263 (71
950). The geometric means for HCB, trans-nonachlor, toxaphenes and the sums of
PCBs and DDTs were higher for the east coast samples than for those from the west
coast, and a decreasing trend in concentrations followed the east Greenland
current. No geographical trend was apparent for HCHs. Differences in
concentrations between females and males were only significant for HCB and HCH
within certain age classes and sampling areas. A tendency for concentrations to
increase with age was observed, but was not statistically significant. Principal
component analyses for PCB congeners revealed that the proportion of higher
chlorinated PCBs (Cl atoms > or = 6) decreased with decreasing concentrations of
PCBs found for the four sampling areas. No differences between the higher and
lower chlorinated PCBs were seen in females and males, but a higher proportion of
CB-105 and CB-118 compared to CB-52 and CB-101 was seen in male seals compared to
female seals.
PMID- 10682361
TI - TBT in marine sediments and blue mussels (Mytilus edulis) from central-west
Greenland.
AB - Concentrations of butyltin compounds were investigated in the bivalve Mytilus
edulis (five sites) and marine sediments (three sites) near the largest town,
Nuuk, in Greenland. In seven of the eight samples the extremely toxic compound
tributyltin (TBT) was detected. The concentrations of tributyltin and degradation
products in the bivalves were close to 1 microgram kg-1 wet weight (ww),
calculated as Sn, which is lower than those found in Iceland and the Faeroe
Islands. In sediments the concentration of TBT ranged from below the limit of
detection of 1 microgram kg-1 to 171 micrograms kg-1 dry weight (dw), calculated
as Sn, which is comparable to levels found in Europe.
PMID- 10682360
TI - Organochlorines in Greenland glaucous gulls (Larus hyperboreus) and Icelandic
gulls (Larus glaucoides).
AB - Glaucous gulls (Larus hyperboreus) and Icelandic gulls (Larus glaucoides) were
sampled in 1994 from four different areas in Greenland, three on the west coast
and one on the east coast. Livers of 93 glaucous gulls and seven Icelandic gulls
were analysed for polychlorinated biphenyls (PCBs, IUPAC Nos. 28, 31, 52, 101,
105, 118, 138, 153, 156 and 180), DDTs (p,p'-DDE, p,p'-DDD, p,p'-DDT),
hexachlorocyclohexanes (alpha-, beta- and gamma-HCH), hexachlorobenzene (HCB) and
trans-nonachlor (TNC). The overall geometric means of the concentrations found in
glaucous gull liver were for sigma PCBs 388 (range 20-5557), for sigma DDTs 363
(17-8604), sigma HCHs 7.4 (1-53), HCB 47 (4-594) and trans-nonachlor 19 (3-187)
micrograms kg-1 wet wt., respectively. The geometric means of concentrations in
Icelandic gull liver were for sigma PCBs 112 (24-435), for sigma DDTs 95 (25
298), sigma HCHs 2.9 (1.4-5.2), HCB 22 (8-58) and trans-nonachlor 5.1 (2.4-8.6)
micrograms kg-1 wet wt., respectively. Significantly (P = 0.05) higher
concentrations of PCBs, DDTs and HCHs were found in glaucous gulls at
Ittoqqortoormiit at the east coast than in gulls from Qeqertarsuaq at the west
coast of Greenland. This tendency was also seen for HCB and trans-nonachlor, but
the differences were not statistically significant (P = 0.05). A decreasing trend
in organochlorine concentrations followed the East Greenland Current, flowing
from north to south down the east coast and to the north on the west coast. Gulls
taken from the most northerly sampling area of the west coast, however, showed
slightly higher concentrations than those from the central west coast. There
appeared to be a tendency for higher concentrations to be found in males than
females, and in adults compared to young glaucous gulls, but the differences were
not statistically significant (P = 0.05). The concentration ranges found in gulls
from Greenland were similar to those reported previously for gulls from northern
Norway and Russia. A principal component analysis revealed no obvious link
between the presence of higher chlorinated PCBs and higher PCB concentrations in
glaucous gulls. Significantly higher proportions of higher chlorinated PCBs were
found in glaucous gulls than in Icelandic gulls, and in adult glaucous gulls
compared to young gulls of 1-2 calendar years. As no such difference was found
between female and male gulls it seems that PCBs of all degrees of chlorination
may be passed equally well from mother to offspring.
PMID- 10682362
TI - The use of lichen (Cetraria nivalis) and moss (Rhacomitrium lanuginosum) as
monitors for atmospheric deposition in Greenland.
AB - Concentrations of Pb, Cd, Hg, Zn, Cu, Cr, Ni, As, V, Al and Fe are reported from
soil, humus, moss (Rhacomitrium lanuginosum) and lichen (Cetraria nivalis)
sampled at four locations in Greenland. For Al, Fe, Cr and V the levels in soil
were highest followed by humus and R. lanuginosum and with the lowest levels in
C. nivalis. The same was true for Pb, Cu and Ni but without as great a difference
between medias. For Cd and Hg, the lowest levels were found in soil. For Zn and
As, the media with highest levels differed between locality. Data were examined
by a principal component analysis. Three principal components explained 87% of
the total variation. The dominant elements in the first component were Fe, Al, V,
Ni, Cr, Cu and Pb. This component is interpreted as a soil dust factor. The
concentrations in R. lanuginosum and C. nivalis of these elements are believed to
be highly influenced by soil dust. Pb concentrations in moss and lichen may also
be influenced by other sources as Pb also had some correlation's with the third
component. Zn and Cd and to a lesser extent. As were the dominant elements in the
second component. The third component was highly dominated by Hg with a lesser
influence of Pb and As, Zn, Cd and Hg concentrations in R. lanuginosum and C.
nivalis are believed to be influenced by other sources than soil dust which may
be long-range atmospheric transport. In general, both the within locality and the
between locality variability in the values of the three components decreased in
the order soil, humus, R. lanuginosum and C. nivalis. The lichen C. nivalis is
looked at as an indicator with greater potential for monitoring atmospheric
deposition of elements than the moss R. lanuginosum.
PMID- 10682363
TI - Lead, zinc, cadmium, mercury, selenium and copper in Greenland caribou and
reindeer (Rangifer tarandus).
AB - Samples of caribou and reindeer muscle (127 samples) and liver (126 samples) were
collected from four locations during two seasons plus 3 years in Greenland. The
levels of lead, zinc, cadmium, mercury, selenium, and copper were determined, and
analyzed in relation to location, two seasons, age and year of sampling. The lead
concentrations (geometric mean) ranged from below the detection limit to 0.007
microgram/g wet weight (wet wt.) in muscle and from 0.027 to 0.926 microgram/g
wet wt. in liver. Zinc geometric mean concentrations ranged from 17.5 to 39.6
micrograms/g wet wt. in muscle and from 23.2 to 31.7 micrograms/g wet wt. in
liver. For cadmium, the geometric mean concentrations were at, or below the
detection limit in muscle, while concentrations in liver ranged from 0.121 to
0.695 microgram/g wet wt. Mercury levels ranged from 0.003 to 0.043 microgram/g
wet wt. in muscle and from 0.040 to 0.618 microgram/g wet wt. in liver. Selenium
concentration levels in muscle ranged from 0.030 to 0.252 microgram/g wet wt.,
and from 0.085 to 0.984 microgram/g wet wt. in liver. Copper levels in muscle
ranged from 2.09 to 3.60 micrograms/g wet wt., and from 21.8 to 71.0 micrograms/g
wet wt. in liver. Mercury concentrations were higher than those found at lower
latitudes in Norway and Canada, especially in Isortoq in southern Greenland.
Selenium levels were also high compared to other Arctic regions. Concentrations
of lead, zinc, cadmium and copper are similar to those reported in caribou from
Canada and Norway. Concentrations of elements generally decreased in the
following order: Isortoq > Akia > Itinnera > Kangerlussuaq, and there was only
found minor variation in the annual levels during 3 years in Itinnera. Late
winter levels were generally significantly higher than early winter levels
especially in the lichen-rich localities, and it is suggested that the
availability of lichens as winter forage is the key determining the level of
elements. Accordingly, when using caribou and reindeer as monitoring organism,
knowledge of winter forage is very important for interpretation of results.
PMID- 10682364
TI - Mercury in Arctic char (Salvelinus alpinus) populations from Greenland.
AB - Mercury concentrations were determined in muscle tissue of lake resident and
anadromous populations of Arctic char in Greenland. Mercury in lake sediment, and
in soil and humus from the surrounding area were also determined in the main
localities. Fish length and dry weight were shown to be important covariables,
which have to be taken into account when comparing mercury levels between
populations. Variations in fat content did not contribute further to the
differing mercury concentrations. Mercury concentrations in lake sediments, humus
from around the lakes and resident populations of Arctic char from west Greenland
and south-west Greenland were higher than for populations from east Greenland and
north-west Greenland. The mercury level in anadromous populations was found to be
10-15-fold lower than that found in lake resident populations, and similar to
that found in marine fish species. Methyl mercury was determined in two of the
populations investigated, and constituted 72-92% of the total mercury.
PMID- 10682365
TI - Organochlorines in Greenland lake sediments and landlocked Arctic char
(Salvelinus alpinus).
AB - Lake sediments and landlocked Arctic char (Salvelinus alpinus) were sampled in
1994 and 1995 at four different locations in Greenland, three at the west coast
and one at the east coast. Sediments, char muscle and char liver were analysed
for PCBs (10 congeners), DDTs (pp'), HCHs (alpha, beta, gamma), dieldrin, HCB and
chlordanes (5) and char in addition to toxaphene (total and 4 congeners). All
organochlorines in the sediment samples were below the detection limit of 0.1
microgram kg-1 dry wt., while the overall geometric means in Arctic char muscle
were, in microgram kg-1 wet wt., for PCBs 11 (range 1-140), for DDTs 4.0 (1-35),
for HCHs 0.4 (0.06-1.5), for dieldrin 0.7 (< 0.1-4.2), for HCB 0.7 (0.09-3.8),
for chlordanes 4.8 (1-57) and for total toxaphene 13 (1-180). The sums of PCBs,
DDTs, chlordanes and total toxaphene disclosed higher concentrations in muscle of
char from the east coast compared to char from the west coast. Dieldrin and HCB
showed the same tendency, but less pronounced, while the sum of HCHs were found
in highest concentrations at the west coast. PCB, DDT, chlordane and toxaphene
concentrations showed a decreasing trend following the East Greenland Current.
Principal component analysis on PCB congeners showed that the proportion of
higher chlorinated PCBs (Cl > 5) were higher in Qaqortoq in south Greenland
compared to the three other sampling areas in Greenland. However, no correlation
was seen either between degree of chlorination and latitude or between degree of
chlorination and PCB concentrations.
PMID- 10682366
TI - Lead, cadmium, mercury and selenium intake by Greenlanders from local marine
food.
AB - The human intake of lead, cadmium, mercury and selenium from local Greenlandic
marine food was estimated based on dietary studies and contaminant information.
The average lead intake was calculated to be 15 micrograms/person per week, which
is very low, whereas the intake of cadmium and mercury was estimated to be very
high, on average 1004 micrograms/person per week for cadmium and 846 for mercury,
thereby significantly exceeding limits established by FAO/WHO. The main cadmium
and mercury source was seal liver. Selenium intake was also high with whale skin
as the dominant source.
PMID- 10682367
TI - Organochlorines and heavy metals in pregnant women from the Disko Bay area in
Greenland.
AB - Recent studies from Greenland and the Canadian Arctic have shown high
concentrations of heavy metals, such as mercury, and organochlorines in the blood
and fatty tissue of the Inuit. This is attributed in particular to their high
consumption of the meat and blubber of marine mammals. In the present study, 180
pregnant women and 178 newborn babies were studied, amounting to 36% of the total
number of births in the Disko Bay area during 1994-1996. The pesticides found in
the highest concentrations in maternal blood were DDE (4.8 micrograms/l wet wt.),
trans-nonachlor (1.6 micrograms/l) and hexachlorobenzene (1.2 micrograms/l) while
the total concentration of PCB (Aroclor 1260) was 19.1 micrograms/l. Calculated
on a lipid basis, concentrations were slightly higher in maternal than in cord
blood. The mercury concentrations were 16.8 micrograms/l in maternal blood and
35.6 micrograms/l in cord blood. In a linear regression analysis, the
concentrations of organochlorines, mercury and selenium increased with maternal
age. Concentrations of mercury and cadmium increased with the consumption of
marine mammals, and cadmium was associated with smoking. The contaminants are
potentially toxic for several organ systems but the high concentrations of
pollutants have so far not been shown to influence health in Greenland.
PMID- 10682368
TI - Analytical methods, quality assurance and quality control used in the Greenland
AMAP programme.
AB - The majority of analytical results in the Greenland AMAP (Arctic Monitoring and
Assessment Programme) have been produced by laboratories that participate
regularly in performance studies. This makes it possible to judge the quality of
the results based on objective measurements made by independent assessors. AMAP
laboratories participated while analysing the AMAP samples in the QUASIMEME
laboratory performance study programme, in the 'Interlaboratory Comparison
Program' organised by Le Centre de Toxicologie du Quebec, in a toxaphene
intercomparison study organised by The Food Research Division of Health Canada,
and in an International Atomic Energy Agency Intercomparison exercise. The
relative errors of the trace analyses, i.e. the relative deviation of the result
obtained by the AMAP laboratory from the assigned value, are in most cases less
than the 25% which is regarded as acceptable by QUASIMEME. Usually the errors,
especially for trace elements, are less than 12.5%, while errors for trace
organics below 1 microgram kg-1 may rise to 50% or more. This study covers the
period 1993 to 1998 for trace elements and one or more years from the period 1994
1996 for trace organics.
PMID- 10682369
TI - Comparison of contaminants from different trophic levels and ecosystems.
AB - The present paper provides an overview of the priority contaminants and media
from the Greenland part of the Arctic Monitoring and Assessment Program. Levels
and accumulation patterns of heavy metals, POPs and a radionuclide (137Cs) are
compared from the terrestrial, freshwater and marine ecosystems. Of the nine
compounds presented, seven (Cd, Hg, Se, sigma PCB, sigma DDT, sigma HCH, HCB)
increased in concentration towards higher trophic levels. For these contaminants
the concentrations in soil and aquatic sediment were in the same order of
magnitude, whereas the concentrations in marine biota were higher than found in
the freshwater and terrestrial ecosystems probably due to the presence of longer
food chains. Pb and 137Cs showed the reverse pattern compared with the other
compounds. The concentrations in soil and aquatic sediments decreased in the
order terrestrial, freshwater and marine ecosystems, which was reflected in the
biota as well. Reindeer had similar or lower levels of Pb and 137Cs than lichens.
Levels of Pb and 137Cs in marine biota did not show the same clear increase
towards higher trophic as found for the other analysed compounds. Greenland Inuit
contains considerably less mercury but higher levels of sigma PCB, sigma DDT and
HCB than other Arctic marine top consumers.
PMID- 10682370
TI - Environmental radioactive contamination in Greenland: a 35 years retrospect.
AB - Environmental studies of anthropogenic radionuclides in Greenland over four
decades are reported. The studies have comprised the marine as well as the
terrestrial environments and emphasis has been laid on measurements of 90Sr and
137Cs. The temporal and the spatial trends of these radionuclides are described.
The radiation exposure from consumption of locally produced diets has been
calculated from consumption rates and the infinite time integrated levels of 90Sr
and 137Cs concentrations in the various food products. Compared with most other
Arctic people, the Greenlanders have received relatively low doses from
anthropogenic radionuclides. There are several reasons for this, first of all,
because of the relatively high consumption of marine products compared with
terrestrial products. Secondly, because winter slaughtering of reindeer is less
frequent in Greenland than in other Arctic countries and Greenland reindeer
consume, in general, less lichen than most other Arctic reinder, and thirdly,
because the transfer from deposition to lichen in Greenland seems lower than in
other Arctic areas.
PMID- 10682371
TI - Evaluation of the Greenland AMAP programme 1994-1995, by use of power analysis
(illustrated by selected heavy metals and POPs).
AB - The levels of PCBs, HCB, HCHs, DDTs, Cd, Pb, Hg and Se, and especially the
variability in biota obtained during Phase 1 of the Greenland AMAP-programme have
been used to illustrate the ability of the programme to detect differences in
contaminant levels over time. The statistical power of t-tests of contaminant
levels are illustrated according to various scenarios of magnitude of change,
significance level and sample size. The statistical power of various time series
of contaminant levels to detect linear trends in mean log-concentrations,
including a random between-year variation component, is illustrated. We conclude
that the ability to detect differences is rather poor for many combinations of
contaminants and media, and that long time series are needed before temporal
trends are likely to be detected.
PMID- 10682372
TI - Critical loads of acidity for surface waters in China.
AB - For further control of acid rain and sulphur dioxide pollution, the Chinese
government has designated the Acid Rain Control Zone and the Sulphur Dioxide
Pollution Control Zone for those areas that are, or could become, affected by
acid deposition or ambient sulphur dioxide concentrations. One of the most
important principles for designating the Acid Rain Control Zone is that the
critical load is exceeded by the sulphur deposition. Through the steady-state
water chemistry method (SSWC), critical loads of acidity for surface waters were
mapped based on available data. Results show that surface waters sensitive to
acid deposition, i.e. surface waters with low critical loads, are mainly found in
north-east China, on the Tibetan Plateau, and in north-west China. Compared with
the critical loads of soils, critical loads of surface waters are usually higher
in almost all areas in China. The reason for very low critical loads of surface
waters in some regions dominated by soils geologically not sensitive to acid
deposition may be attributed to the low temperature, high altitude and low
runoff. In contrast, surface waters in south China are not susceptible to acid
deposition, and so far acidification of surface water has not been found in spite
of the heavy acid rain. As can be seen from the critical load exceedance map,
nearly 10% of the surface waters are subject to risk of acidification in 1995.
PMID- 10682373
TI - Quantitative structure-property relationships for direct photolysis quantum
yields of selected polycyclic aromatic hydrocarbons
AB - By the use of partial least squares (PLS) method and 11 quantum chemical
descriptors computed by PM3 Hamiltonian, Quantitative Structure-Property
Relationships (QSPRs) for direct photolysis quantum yields of selected polycyclic
aromatic hydrocarbons (PAHs) were obtained. Direct photolysis quantum yields were
predicted for PAHs for which experimental quantum yield values were lacking.
Based on the QSPR models, significant PAH molecular characters governing their
direct photolysis quantum yields were identified. It can generally be concluded
that PAHs with large average molecular polarizability, molecular weight, and heat
of formation values tend to have small photolysis quantum yields. PAHs with large
values of the energy of the lowest unoccupied molecular orbital (Elumo), small
values of the energy of the highest occupied molecular orbital (Ehomo), and large
Elumo-Ehomo values, tend to have great photolysis quantum yields.
PMID- 10682374
TI - The chemistry of Norwegian groundwaters: III. The distribution of trace elements
in 476 crystalline bedrock groundwaters, as analysed by ICP-MS techniques
AB - Four hundred and seventy-six groundwater samples from boreholes in Norwegian
crystalline bedrock have been analysed by ICP-MS techniques. The results for 53
trace elements are presented as cumulative frequency distribution diagrams and
are compared with relevant international drinking water norms. A range of trace
elements appear to be enriched in granitic waters and depleted in anorthositic
waters which is to be expected as generally granitic rocks are enriched in trace
elements above those in anorthosites. A selection of elements which may be toxic
in excess when present in drinking water are further discussed (Be, Tl, Th, U,
Cd, Pb, As, Ni, and Hg). For uranium, 18% of the samples exceed the American
maximum admissible concentration of 20 micrograms/l; 7% of the samples fail to
meet the Russian drinking water norms for beryllium of 0.2 microgram/l. For some
parameters such as U, Be and Tl, no Norwegian drinking water regulations are set,
while the American and the Russian norms differ significantly from each other.
Between 0 and 1.5% of the wells exceed Norwegian drinking water norms for each of
the other selected elements.
PMID- 10682375
TI - Inhalation exposure to THMs from drinking water in south Taiwan.
AB - Trihalomethanes (THMs) are important disinfection byproducts (DBPs) in drinking
water. To understand the magnitude of exposure to THMs for the people in southern
Taiwan, models are used to estimate the inhalation exposure associated with
drinking water based on raw water quality. Two parts of models are used in this
study, one for estimating THM concentration from raw water quality, and one for
estimating inhalation exposure to people. Important raw water quality and
operational parameters, including TOC, UV254, pH, temperature, chlorine dosage,
and water residence time of a major water treatment plant in south Taiwan were
collected. An empirical THM formation model was then employed to predict the THM
concentration at consumers' dwellings based on the parameters collected.
Differences between the predicted results and experimental data were found to be
small, indicating that the model is appropriate. The predicted THM concentration
distribution was served as input parameters for the exposure models. Three major
scenarios associated with probable inhalation exposure of THMs, including shower,
pre- and post-cooking activities, and cooking processes, were considered in the
exposure models. The model results show that the mean inhalation exposure of THMs
for shower, pre- and post-cooking activities, and cooking processes are 26.4,
1.56, 3.29 micrograms/day, respectively. The total inhalation exposure (summation
of the three scenarios) was found to be comparable with that for direct
ingestion, indicating that inhalation is an important pathway for THM exposure
from drinking water.
PMID- 10682376
TI - The influence of a capacitor plant in Serpukhov on vegetable contamination by
polychlorinated biphenyls.
AB - PCB content in soil and vegetables grown on the polluted soils in some districts
of the town of Serpukhov have been studied for 10 years after the use of PCBs had
been banned at the local capacitor plant. Soil contamination with PCBs in the
vicinity of the plant is still extremely high (up to 30 mg/kg). Vegetables grown
on the polluted soils, especially carrots and green parts of fennel, parsley,
celery are also highly contaminated. The primary pollutants are found to be tri-
and tetrachlorobiphenyls (up to 70-80% of total PCBs).
PMID- 10682377
TI - Concentrations of mercury, cadmium, lead and copper in fruiting bodies of edible
mushrooms in an emission area of a copper smelter and a mercury smelter.
AB - Four metals were determined by AAS techniques in 56 samples of 23 wild mushroom
species collected in a heavily polluted area in eastern Slovakia in 1997 and
1998. The area has been contaminated from historical polymetallic ores mining and
smelting and by emissions from a mercury smelter between 1969 and 1993 and from a
copper smelter since 1951. No significant differences in metal concentrations (P
< 0.05) were found in four species when comparing the periods 1992-1993 and 1997
1998. Considerable contamination of most species was observed mainly for mercury
and cadmium. The highest levels of mercury, up to 50 mg kg-1 dry matter, were
found in Boletus reticulatus, Lycoperdon perlatum and Marasmius oreades, and of
cadmium up to 20 mg kg-1 dry matter in Xerocomus chrysenteron and Lycoperdon
perlatum. The latter species also had extremely high lead and copper
concentrations in hundreds of milligrams per kilogram dry matter. Concentrations
of mercury and copper in caps of four Boletaceae species were significantly (P <
0.05) higher than those in stipes.
PMID- 10682378
TI - A biokinetic model for lead metabolism with a view to its extension to pregnancy
and lactation; (1). Further validation of the original model for non-pregnant
adults.
AB - A published biokinetic model that describes the absorption, transfer between
organs and excretion of lead (Pb) in humans has been established using
commercially available simulation software. Recent in vivo data have been used to
validate further the model in adults, particularly for non-pregnant females. The
validation data centre on: (a) the prediction of blood Pb concentrations due to
changes in atmospheric and dietary Pb levels over the last 25 years; (b) the non
linear relationship between Pb in whole blood and that in blood plasma which can
be transferred to other organs; and (c) the accumulation of Pb in bone which may
be re-mobilised later in time of calcium stress. This work underpins our
alteration of the model to encompass pregnancy and lactation so that the build-up
of Pb in the developing foetus and breast-fed infant can be estimated from any
number of current and historical maternal exposure scenarios.
PMID- 10682380
TI - Trends in veterinary clinical and fundamental pharmacology: past and future in
The Netherlands.
AB - Veterinary pharmacology has undergone a gradual development in the Netherlands
during this century. Starting from a historical perspective the paper aims to
provide an overview of future trends and important issues in the area of
veterinary pharmacology and toxicology. It is pointed out that this discipline
comprises several subdisciplines as the comparative aspect of both, pharmacology
and toxicology, is inherent to veterinary medicine which has to address a broad
variety of animal species. Thus, the comparison of drug effects, side effects,
and drug disposition as well as the comparison of the species-specific
susceptibility to xenobiotics are obvious challenges in this discipline. Several
areas in clinical pharmacology are highlighted to indicate future research needs.
Finally, the principles of Good Veterinary Practice are presented as the 'golden
standard' in veterinary clinical pharmacology.
PMID- 10682379
TI - Response of stress indicators and growth parameters of Tibouchina pulchra Cogn.
exposed to air and soil pollution near the industrial complex of Cubatao, Brazil.
AB - The present study was performed in the vicinity of the industrial complex of
Cubatao, Sao Paulo, Brazil, in order to evaluate the response of 'manaca da
serra' Tibouchina pulchra Cogn. (Melastomataceae), a common species of secondary
Atlantic Rain Forest vegetation, to the impact of complex air pollution. Emphasis
was given to changes of biochemical parameters such as ascorbic acid
concentration, peroxidase activity, contents of water-soluble thiols, pH of leaf
extract and buffering capacity. These plant factors are often used as early
indicators of air pollution stress. Field experiments included sampling of leaves
from mature trees in areas with different air pollution load (passive
monitoring), exposure of saplings cultivated in uniform soil at these areas
(active monitoring) and a study on the combined effects of contaminated soil and
air pollution. In general, metabolic response of saplings was more accentuated
than that of mature trees. Leaf extract pH and buffering capacity showed no or
only small alterations in plants exposed to industrial emissions. In contrast,
air pollution resulted in a distinct decrease in ascorbic acid contents and an
increase in peroxidase activity and thiol concentrations in leaves. Cultivation
of saplings in soil types from contaminated regions frequently caused the same
modifications or enhanced the effects produced by air pollution. Growth analysis
of exposed saplings demonstrated that a change of the relationship between above
ground and below-ground plant parts was the most obvious effect of air pollution
and soil contamination. The experiments showed that even T. pulchra, a species
considered resistant to air pollution, suffers metabolic disturbances by the
present ambient air and soil quality. Although biochemical and physiological
alterations were not related to a certain air pollution type, they could be used
to estimate the overall pollution load and to map zones with different air
quality.
PMID- 10682381
TI - Signal transduction in inflammatory processes, current and future therapeutic
targets: a mini review.
AB - The selective control of inflammatory reactions will continue to be a major issue
in the development of new drugs. Many new molecular targets are coming up. This
paper highlights a few key mediators that are nowadays considered as interesting
therapeutic intervention points. Cytokines play an important regulatory role in
the initiation, maintenance and termination of inflammatory reactions. More than
50 cytokines have been identified, and more and more has become known about their
receptors and signal transduction pathways. Tumour necrosis factor-alpha (TNF
alpha) is still regarded as one of the initial cytokines of the cascade, and
different approaches are followed to control its synthesis, release or effects.
Lipopolysaccharide (LPS) is a one of the triggers that is able to induce a strong
TNF-response. Inhibitors of cyclic nucleotide phosphodiesterases (PDEs),
including rolipram and pentoxifylline suppress the LPS-induced TNF-alpha
production in monocytes/macrophages. In our laboratory it has been shown that the
alternative way to increase cAMP levels, via stimulation of beta-adrenergic
receptors, also provides an effective way, both in vitro and in vivo, to inhibit
TNF-alpha release. Other therapeutic ways include the use of antibodies directed
to cytokines, TNF receptor fused to IgG, antibody therapy against TNF, the use of
MAP kinase inhibitors. The different signal transduction pathways, including the
NF-kappa B activation route may provide alternative pharmacological tools. We may
surely expect anti-inflammatory drugs of much greater specificity to be developed
in the next decade. Despite the relative limited investments in veterinary drug
development this will also have consequences for veterinary therapy.
PMID- 10682382
TI - Cytochromes and cytokines: changes in drug disposition in animals during an acute
phase response: a mini-review.
AB - Diseases are a major cause of variation in drug response. Although many different
diseases are known that have an effect on the pharmacokinetics or sometimes the
pharmacodynamics of a drug, disorders associated with a so-called acute phase
response (APR) are the most important in this respect. During APR, for example
caused by tissue damage or invasion of a pathogen, a group of symptoms can be
observed that often include fever, lassitude, inhibition of gastric function and
synthesis of acute phase proteins. All phases that together determine the
pharmacokinetic profile of a drug, absorption, distribution, metabolism and
excretion, can be affected during APR. From a clinical point of view however, the
effects on absorption and metabolism are the most relevant. For drugs that are
given orally, a slower absorption rate is often observed during APR due to a
delayed gastric emptying. Even more important from a clinical point of view is
the depression of biotransformation capacity in the liver during APR, especially
affecting the enzymes of the cytochrome P450 (CYP450) complex. Although much has
become known about the mechanism of this effect, a number of questions remain.
Cytokines, nitric oxide and possibly the enzyme heme oxygenase are playing a role
in a complex process that depends on a mutual interaction between Kupffer cells
(macrophages) and hepatocytes in the liver. The clinician should be aware of
unexpected changes in drug effects or residue levels due to cumulation of the
compound during disease or after vaccination. In these situations, drugs that are
excreted unchanged may be better alternatives.
PMID- 10682383
TI - Cocultures of porcine hepatocytes and Kupffer cells as an improved in vitro model
for the study of hepatotoxic compounds.
AB - In this study primary hepatocyte cultures (HC cultures) and cocultures comprised
of hepatocytes and Kupffer cells (HC/KC cocultures) were compared to investigate
the inflammatory response induced by lipopolysaccharide (LPS). In addition both
culture types were compared to study the hepatotoxic effects of two frequently
used drugs: tiamulin and chlorpromazine. The inflammatory response in both
culture types was determined by measurement of tumour necrosis factor-alpha (TNF
alpha), interleukin 6 (IL-6) and nitric oxide (NO). The drug-induced hepatotoxic
effects were determined by measuring production of intracellular reactive oxygen
species (ROS) and cytotoxicity. Exposure of both cultures to LPS resulted in a
significantly increased production of TNF-alpha, IL-6 and NO. However, the
production of TNF-alpha, IL-6 and NO was substantially increased in culture
supernatant of cocultures, compared to single HC-cultures. Both tiamulin and
chlorpromazine were potent inducers of intracellular ROS production at
concentrations > or = 50 microM. High ROS production was paralleled by increased
cytotoxicity as observed in both culture types. Incubation of cocultures with
chlorpromazine resulted in a significant increased ROS production as compared to
HC cultures. In contrast, no significant differences between HC-cultures and
HC/KC cocultures were observed for tiamulin induced ROS production or
cytotoxicity. The present study demonstrates that cocultures between Kupffer
cells and hepatocytes provide an excellent model for the study of hepatotoxic
compounds which exert (part) of their toxic effects via the activation of Kupffer
cells. Furthermore they offer a valuable tool to study increased susceptibility
to intoxication from xenobiotic agents in case of a concurrent or pre-existing
inflammation.
PMID- 10682384
TI - Suppression of the acute inflammatory response of porcine alveolar- and liver
macrophages.
AB - During infection and inflammation drug disposition and hepatic metabolism are
markedly affected in mammals. Pro-inflammatory mediators play an important role
in the suppression of (cytochrome-P450-mediated) drug metabolism. Inflammatory
mediators like cytokines, nitric oxide (NO), reactive oxygen species (ROS) and
eicosanoids are released by activated macrophages from various sources, including
liver and lung. It was the aim of this study to investigate ways to suppress the
activation of macrophages during the onset of the inflammatory cascade. Therefore
porcine lung and liver macrophages were isolated, and incubated with
lipopolysaccharide (LPS) to initiate an acute inflammatory response, represented
by the release of high amounts of tumour necrosis factor-alpha (TNF-alpha) into
the culture medium. Additionally the primary macrophages were coincubated with
phosphodiesterase-IV-(PDE-IV)-inhibitors or beta-adrenoceptor agonists that in
previous studies demonstrated strong suppressive effects on TNF-alpha release.
Especially the beta-adrenoceptor agonists showed to be very potent TNF-alpha
suppressants, which indicates that the beta-adrenoceptor might be an interesting
target for suppression of activation of macrophages. This was strengthened by the
observation that the beta-adrenoceptor expression was not altered during the
onset of the inflammatory cascade.
PMID- 10682385
TI - Inhibition of aflatoxin M1 production by bovine hepatocytes after intervention
with oltipraz.
AB - It is well known that cattle ingesting aflatoxin B1 contaminated feed commodities
excrete aflatoxin M1 into their milk. As aflatoxin M1 originates from hepatic
metabolism, measures to prevent aflatoxin M1 formation need to be directed to
either the immobilization of aflatoxin B1 in the gastrointestinal tract or the
modification of hepatic metabolism of aflatoxin B1. Here we studied the influence
of oltipraz and a second dithiolthione, (1,2) dithiolo (4,3-c)-1,2-dithiole-3,6
dithione (DDD) on bovine hepatic aflatoxin B1 biotransformation. Oltipraz
inhibited aflatoxin B1 metabolism as no aflatoxin M1 and no aflatoxin B1
dihydrodiol, the second metabolite found in bovine hepatocytes, was formed. DDD
did not significantly inhibit aflatoxin B1 metabolism. It could be demonstrated
that the inhibition of aflatoxin B1 metabolism was due to the inhibition of
several cytochrome P450 enzyme activities by oltipraz. In contrast, DDD inhibited
only ethoxyresorufin O-deethylation activity. These findings suggest a high
efficacy of oltipraz in inhibiting aflatoxin M1 contamination of milk from dairy
cows exposed to aflatoxin B1 contaminated feeds.
PMID- 10682386
TI - Within-farm spread of classical swine fever virus--a blueprint for a stochastic
simulation model.
AB - A stochastic simulation model to investigate the transmission of classical swine
fever (CSF) virus within an infected farm is described. The model is structured
according to the processes that occur within and between management groups (pig
units or houses). It uses the individual pig as the unit of interest and
estimates the number of animals in the states 'susceptible', 'infected',
'infectious', and 'removed' for each day of the disease incident. Probabilities
are assigned to the transitions between states. The probability of a pig becoming
infected is made dependent on the probability of contact between a susceptible
and an infectious pig as well as the probability of transmission. The more pigs
become infected in one unit, the more likely is subsequent spread to another
management group on the farm. Ultimately, the probability that a shipment of pigs
from the farm will include at least one infected pig can be estimated in order to
identify high-risk movements during a CSF epidemic. The model results were
compared with experimental data on CSF transmission within one pig unit
(management group). It could be shown that the model was capable of reproducing
the experimentally observed infection and mortality rates. To improve the input
parameters and for further model validation, more experimental data and field
data from CSF outbreaks are needed.
PMID- 10682387
TI - Disease-induced alterations in plasma drug-binding proteins and their influence
on drug binding percentages in dogs.
AB - Disease-induced variations of plasma albumin (ALB) and alpha 1-acid glycoprotein
(AAG) levels were investigated in dogs. Lower ALB (sometimes > 50% reduction) and
higher AAG (sometimes > 10-fold increase) levels were observed in dogs with
various diseases. Drug binding was determined at therapeutic concentrations using
normal, low-ALB and high-AAG dog plasma. The binding percentages of the ALB
binding drugs decreased in low-ALB plasma, resulting in a large increase in
unbound drug, particularly for naproxen (a 13-fold increase). The binding
percentages of all AAG-binding drugs investigated in this study increased in high
AAG plasma, resulting in a large decrease in unbound drug, particularly for
quinidine (99% decrease). The fluctuation in the unbound fraction of drugs could
affect their efficacy or could cause side-effects. Veterinary clinicians should
monitor the ALB and AAG levels in the plasma of patients and correct dosage
regimens according to these levels, where field conditions permit this, in order
to ensure the proper usage of drugs with high affinity for ALB or AAG.
PMID- 10682388
TI - Validation of a new method of visual oestrus detection on the farm.
AB - Since visual observation is the most commonly used way of detecting oestrus and
is supposed to be as effective as detection with technical devices, we evaluated
a recently developed oestrus detection scoring system in daily dairy practice. In
this scoring system nine signs of oestrus are scored with points, ranging 3 to
100. Twenty-one dairy farmers used the scoring system during a period of 3 weeks.
All cows that were more than 30 days post partum and not confirmed pregnant were
monitored, using the scoring system, by the herd owners. Oestrus was confirmed by
measuring progesterone concentrations in milk. With the scoring system a
detection rate of 47% was achieved. This was lower than expected, because in an
earlier control period, the detection rate was 64%. We concluded that this new
method might be too complicated to introduce to normal herd management, because
in daily practice it is too demanding to watch cows twice a day for 30 minutes,
especially if the cows show only vague and infrequent symptoms of oestrus. It
also appeared to be too complicated to watch the herd at the most appropriate
time. However, if the scoring system is included in the daily routine, meaning
that farmers are trained to watch for other symptoms than standing heat only and
are able to recognize their different values, it can be a valuable aid to oestrus
detection.
PMID- 10682389
TI - Urinary concentration of corticoids in ponies with hyperlipoproteinaemia or
hyperadrenocorticism.
AB - The urinary corticoid:creatinine (c:c) ratio was determined in ten pony mares
suffering from hyperlipoproteinaemia. The mean (+/- sd) urinary c:c ratio of
these ten ponies (47 +/- 31 x 10(-6)) was not significantly different from that
of twelve pony mares with a pituitary pars intermedia adenoma (31 +/- 18 x 10(
6). The correlation between the urinary concentration of corticoids and plasma
total lipids, and the correlation between the urinary c:c ratio and plasma total
lipids in ponies with hyperlipoproteinaemia were not significant (P > 0.05; r =
0.53 and r = 0.008, respectively). Preliminary results favour primary
hyperadrenocorticism being associated with hyperlipoproteinaemia. In conclusion,
the data presented here suggest that cortisol can contribute to insulin
resistance in ponies with hyperlipoproteinaemia.
PMID- 10682390
TI - The use of a polypropylene mesh for treatment of ruptured collateral ligaments of
the equine metatarsophalangeal joint: a report of two cases.
AB - The prognosis of ruptured collateral ligaments of the metacarpophalangeal or
metatarsophalangeal joint in horses is usually considered to be poor, especially
for future athletic performance. The main problem is the development, due to
joint instability, of osteoarthritis, which may result in persistent lameness. In
this paper a surgical technique is described in which joint stabilisation is
realised by using a polypropylene mesh as a substitute for the ruptured
ligaments, with the subsequent application of a cast for 7 weeks. The technique
was successfully performed in 2 horses with ruptured lateral collateral ligaments
of a metatarsophalangeal joint. Fifteen months after surgery both horses resumed
exercise. Performance could be classified as fair in one case and good in the
other. It is concluded that the preliminary results obtained with this surgical
technique to stabilise ruptured collateral ligaments of the fetlock joint are
promising.
PMID- 10682391
TI - [Ethics and life: bioethics studies].
AB - A year ago, in June 1998, Diego Gracia published four volumes under the general
title of Bioethics and Life: Studies of Bioethics. These volumes are the
continuation of two other books published by the same author during the last
years: Foundations of Bioethics (1989) and Decision procedures in clinical ethics
(1991). The present article is a short presentation of the four volumes written
by the author, followed by the transcription of the foreword of the book. Due to
the fact that this book is one of the most important contributions made to
bioethics in the Spanish speaking world, it will have a very wide influence not
only in Spain but also in Latin America.
PMID- 10682392
TI - [Determination of allelic losses in peritumor bronchial mucosa].
AB - Lung cancer is the leading of death in both, women and men in the United States
and many European countries. molecular cytogenetic and LOH analyses and LOH
analyses of non-small cell lung cancer have shown somatic genetic alterations in
a variety of chromosomes such as 1p, 3p, 5q, 8p, 9p, 11p, 11q and 17p. Putative
tumor suppressor genes have been located in these lci. Allelic loss at 3p21, 9p21
and 5q21 has been also reported in premalignant epithelial lesions of the
bronchus. We investigated 33 cases of NSCLC for LOH at 3p, 5q, 9p and 17p: 22
squamous cell and 11 adeno carcinomas. Normal lymphocytes, tumor cells and normal
bronquial cells adjacent to the tumor were microdissected from paraffin embedded
tissues. PCR amplification was performed utilizing the specific markers D5S299,
D5S346, D3S1300, D9S157, D9S171 and D17S799. Our results show that within the
NSCLC tumor cells, LOH was more frequently found at the 5q21 locus (75% of the
informative cases), the 3p21 locus (48%) and 17p. Within the normal bronquial
cells, LOH was found in 33% of the cases at 5q21 and 33% of the cases at 3p21. In
conclusion our results show that LOH can be assessed in normal bronquial mucosae
adjacent to NSCLC. We suggest that LOH at these loci may be present before the
onset of the malignant growth.
PMID- 10682393
TI - [Spa therapy and sadness].
AB - The feeling of sadness is said to be an individual problem which can take
advantage of an adequate Spa therapy in all its complexity. The sadness as a
feeling of disproportional affective reaction with mental consequences, can find
relief in the Spa cures and their different structural elements like the
hydrothermal techniques, psychical actions, environmental features..., etc. These
Spa cures have many favourable effects not only on the body but also on the mind,
being capable of liberating the mind of worries and respecting the peculiar
personality and way of suffering of the patient.
PMID- 10682394
TI - [Arterial grafts].
AB - After a historical review, pointing out the different types of grafts (tubes,
veins, arteries, synthetic material), several haemodynamics facts are commented,
that in author's opinion, are closely related with biological process of "neo
intima" development. Technical aspects are evaluated, including extra-anatomical
by-pass, infection risk, and proposed solutions when run-off problems occurred
when placing a graft, concluding with modern guidances when using this material,
such as endotheliation, cryopreserved artery grafts, polyurethane and pyrolytic
carbon grafts, negatively charged grafts, biodegradation prosthesis, laboratory
artery development, small diameter grafts and endovascular surgery.
PMID- 10682395
TI - [History and perspective of reemerging tuberculosis].
AB - The concepts of infectious emergency, the microbial virulence stimulatory
factors, the genetic basis (pathogenicity islands and type III secretion factors)
of the microbial variation and adaptation, the interest of animal reservoirs in
the infection and transmission cycles, and the reemergence of human and animal
tuberculosis are reviewed. In reference to the tuberculosis, the finding of a new
species or subspecies of mycobacteria isolated by the authors laboratory from
goats and belonging to the important M. tuberculosis group is reported.
PMID- 10682396
TI - [Anorectal diseases. Diagnosis and treatment].
AB - The presentation of the book Enfermedades Anorrectales. Diagnostico y tratamiento
edited by Dr Fernando Lopez-Rios (Madrid: Harcourt Brace, 1999) consisted of two
parts. In the first part, the structure, goals and characteristics of the work
were explained by its editor. In the second part, after a brief survey of the
history of colorectal surgery, Dr Lopez-Rios discussed the importance of
understanding colorectal surgery as a subspecialization of general surgery.
PMID- 10682397
TI - [Antepartum brain injuries].
AB - It is generally accepted that congenital brain lesions and especially cerebral
paralysis are produced nearly always during the process of delivery. The origin
can be hypoxia or obstetrical trauma. This has been true until the 70s, but from
that period onwards, the incidence due to the delivery process has been reduced
so dramatically, that its appearance can be considered as an accident, as in the
umbilical cord prolapsus or during abruptio placentae. More than 80% of the
cerebral paralysis occur before delivery due to a variety of causes that are
detailed in this report and only the resting 20% can be related to foetal
asphyxia, only if the following 4 signs appear: 1 Umbilical artery pH lower than
7.2 Apgar test after 5 minutes of 3 or less. 3 Appearance of a neurological
hypoxic-isquemical syndrome. 4 Lesions in another organ that can be attributed to
hypoxia. This new international definition indicates, the necessity to put aside
the old definition still more generally accepted when a fetus is simply depressed
but not with asphyxia. In the same way, the actual concept of fetal suffering
during delivery needs also to be rejected not necessarily alterations are
followed and can be considered as pejorative. Only if the suffering continues
with asphyxia can be accepted.
PMID- 10682398
TI - [Epidermolysis bullosa].
AB - The epidermolysis bullosa are a group of genodermatoses in which there is
congenital fragility of the skin which produce blisters with the least of
traumas. The group includes up to thirty clinical-genetical entities. They are
classified according to the level where the blister is found into simplex or
epidermolytic (intraepitelial blister), junctional (blister in the dermoepidermal
junction) and dystrophic or dermolytic (subepidermal blister) epidermolysis
bullosa. The symptoms, classic or Mendelian genetics and the recent findings in
the most frequent forms of each one of these groups are reviewed. In most of
them, the gene that produces the mutations and the chromosome in which its locus
is found are known. In the simplex forms, the disorders lies in the genes that
codify the different keratins. In the junctional ones, mutations are found in the
laminin genes that act in the development of the anchoring filaments or in those
of the other components of the basement membrane. In the dystrophic ones, which
are the most serious, the mutations affect the collagen VII gene that codify the
development of the anchoring fibrils. There is no treatment for any of the forms
of epidermolysis bullosa. It is possible that the future advances in genetic
engineering can contribute to their prophylaxis.
PMID- 10682399
TI - [Stress and neurodegeneration: pharmacologic strategies].
AB - Long-term exposure to stress has detrimental effects on several brain functions
in many species, including humans and leads to neurodegenerative changes.
However, the underlying neural mechanisms by which stress causes
neurodegeneration are still unknown. We have investigated the role of
endogenously released nitric oxide (NO) in this phenomenon and the possible
induction of inducible NO synthase (iNOS) isoform. In adult male rats, stress
(immobilisation for 6 h during 21 days) increases the activity of a calcium
independent NOS and induces the expression of iNOS in cortical neurons as seen by
immunohistochemical and Western blot analysis. Three weeks of repeated
immobilisation increases immunoreactivity for nitrotyrosine, a nitration product
of peroxynitrate. Repeated stress causes NO2(-) + NO3- (NOx) accumulation in
cortex, and these changes occurs in parallel with lactate dehydrogenase (LDH)
release and impairment of glutamate uptake in synaptosomes. The administration of
the preferred iNOS inhibitor aminoguanidine (400 mg/kg i.p. daily from days 7 to
21 of stress) prevents NOx- accumulation in cortex, LDH release and impairment of
glutamate uptake in synaptosomes, as well as other markers of oxidative stress
such as lipid peroxidation and decrease in glutation. Taken together, these
findings indicate that a sustained overproduction of nitric oxide via iNOS
expression may be responsible, at least in part, of some of the neurodegenerative
changes caused by stress, and support a possible neuro-protective role for
specific iNOS inhibitors in this situation.
PMID- 10682400
TI - [In memoriam of Dr. Juan Gilbert Queralto].
PMID- 10682401
TI - [They thought; therefore, they spoke].
AB - All functions that characteristically define each form of life are the
consequence of the unpredictable process of evolution. The appearance around
300,000 years ago of a complex system of language allowed the homo sapiens to
verbally express his thoughts, feelings and experiences in a narrative manner.
Thus began the great and continuous development of knowledge and the subsequent
post-biological improvement of cognitive functions as a consequence of the
stimulation of brain plasticity. This complex process vas not rapid. Important
structural and functional craneofacial and pharyngo-laryngeal changes were
necessary. Some were already present four million years ago in the
australopitecus and became more efficient in homo erectus to reach the definite
dimensions of modern humans 125,000 years ago in the homo sapiens-sapiens. From
then on a continuous, productive and interactive relationship between the ability
to think and the capacity to speak was established. New anonymous ideas invent
their corresponding words which, in turn, create more complex sequential
thoughts. The fundamental contribution of language in the development of human
intelligence raises the question fo which of the two functions preceded the other
or whether they both evolved simultaneously. Is it possible to assume that if the
pharyngo-laryngeal structures ad not evolved at all, the brain would have
invented another type of language?
PMID- 10682402
TI - [Our brain deceives us].
AB - The brain does not "objectively" reflect outer reality, but rather what is
necessary in order to survive and adapt to the environment. The "phi" phenomenon,
the eye's blind spot and cryptomnesia, reflect the brain's capacity to invent
information. In split-brain patients, research has shown how one hemisphere, when
it lacks certain information, invents a plausible story to explain the behaviour
of the other hemisphere. All this would suggest that the brain deceives us,
producing occurrences which in reality have never happened, in such a way that,
for the brain, convenient reality and "objective" reality are two very different
things.
PMID- 10682403
TI - Synthesis and analgesic activities of 2-substituted-1H-phenantro [9,10-d]
imidazoles.
AB - Some 2-substituted-1H-phenantro [9, 10-d] imidazole compounds were synthesized
and their analgesic activities were determined on the Swiss albino mice (25-35 g)
of either sex. In the synthesis, phenantre-nequinone molecule was reacted with
different aldehyde derivatives in acetic acid presence of ammonium acetate and
finally 16 compounds were gained. All spectral and elemental analyses of the
original compounds were completed and their structures were elucidated. Analgesic
activity of the compounds were examined by using the Tail-Clip method. 2-Phenyl
1H-phenantro [9, 10-d] imidazole (comp.1) and 2-(4-chlorophenyl)-1H-phenantro [9,
10-d] imidazole (comp. 6) were found to be more active than the others and their
LD50 values were found to be greater than 100 mg/kg (i.p.).
PMID- 10682404
TI - Comparative bioavailability of sulfamethoxazole in co-trimoxazole suspensions
containing different thickness agents.
AB - Many workers have attempted to determine the bioavailability of pharmaceutical
formulations, which is important to assure the efficacy and safety of
medications. In the present study, we investigated the bioavailability of five
formulations of the combination of 0.8% trimethoprim (TMP) and 4%
sulfamethoxazole (SMZ) (co-trimoxazole) as a suspension, containing different
types of thickness agents. The blood levels of a single oral dose administered to
rats were compared. Bioavailability was determined by comparing the time to peak
concentration (Tmax), peak serum concentration (Cmax), total area under the
concentration time curve (AUC) and the elimination rate constant (Kel). Analysis
of the pharmacokinetic parameters of SMZ showed significant differences between
the formulations, indicating that the absorption of SMZ was affected by thickness
type. The calculated bioavailabilities of oral TMP and SMZ were 381, 558, 695,
480, 559 and 554 micrograms/mL, respectively, and the preparation containing
hydroxyethyl cellulose 4.400 H as a thickness agent showed the best
bioavailability (AUC 0-infinity = 695.24; micrograms/mL; Cmax = 35.2
micrograms/mL).
PMID- 10682405
TI - Albumin microsphere as a drug delivery system for dexamethasone: pharmacokinetics
in sheep, residue amount in cows and distribution in rats.
AB - The aim of this study was to evaluate the potential use of albumin microspheres
as a drug delivery system to provide sustained release of dexamethasone in vivo.
Pharmacokinetic studies were carried out in sheep and tissue distribution in rats
given dexamethasone in two injectable forms--water suspension of dexamethasone
associated with albumin microspheres and water-ethanol solution of dexamethasone.
When dexamethasone was associated with albumin microspheres the amount of free
dexamethasone, available for absorption did not reach the high values typical of
the pattern of release of dexamethasone from water-ethanol solution. The time of
withdrawal in lactating cows after i.m. administration of DXM-AM was found to be
5 days. The release of dexamethasone from the albumin microspheres was
accomplished gradually thus allowing sustained levels of the corticosteroid to be
maintained for several days in blood plasma, milk, liver, kidney and muscles.
PMID- 10682406
TI - Physico-chemical activity relationship of some substituted benzimidazoles.
PMID- 10682407
TI - Assessment of acute cyto- and genotoxicity of corrosion eluates obtained from
orthodontic materials using monolayer cultures of immortalized human gingival
keratinocytes.
AB - Whilst a patient is undergoing orthodontic treatment, dental appliances based on
non-precious metals or titanium remain in the oral cavity for up to several
years. Throughout this period the appliance is in either direct or indirect
contact with the oral mucosa. To investigate the possibility of cell damage
occurring as a result of appliance corrosion, monolayer cultures of immortalized
human gingival keratinocytes were assessed for acute cyto- and genotoxicity using
the hexosaminidase assay and the Comet assay respectively. The materials tested
included 1. a nickel-free wire, 2. a UK-1 bond, 3. nickel-free as well as nickel
containing brackets with and without color signature and 4. a titanium expansion
screw. Each of the test materials was corroded in a solution consisting of equal
amounts of lactic acid and sodium chloride (0.1 M) for 1, 3, 7 and 14 days. The
cell cultures were then exposed to eluates exhibiting the highest ion
concentrations. None of the eluates was found to exhibit acute cytotoxicity,
regardless of the type of test system used. Qualitative assessment using neutral
red dye for live cells and either trypan blue or propidium iodide to disclose
dead cells failed to reveal any significant increase in cell damage when exposed
cells were compared to control cultures. Unrestricted cell vitality was confirmed
by quantifying viable cells through measurement of hexosaminidase enzyme
activity. Furthermore, assessment of genotoxicity revealed no apparent DNA damage
to immortalized gingival keratinocytes following exposure to the test eluates.
Because the materials tested in this study were corroded using the exacting
methods normally applied to precious metals or gold-containing alloys, the lack
of either acute cyto- or genotoxic effects following exposure to the test eluates
indicates that the materials tested exert no adverse effects on cells similar to
those of the target tissue exposed to the materials in situ.
PMID- 10682408
TI - A longitudinal study on growth in untreated children with Angle Class II,
Division 1 malocclusion.
AB - The aim of this longitudinal study was to analyze growth-related changes in
untreated Class II, Division 1 subjects. Forty untreated Swedish children with
Angle Class II, Division 1 malocclusion were cephalometrically examined. The
average age of the total group was 10.1 years at the first examination and 12.0
at the second. In addition to statistical comparisons of the average values of
variables at both time points, multivariate analyses (harmony box according to
Hasund and Segner, regression equation analyses) were also performed. This
permitted individual evaluation of skeletal structures, position of incisors, and
the soft tissue profile relative to the given craniofacial configuration. With
the ANB angle remaining unchanged, both jaws were transposed ventrally. The
reduction of the angle between the palatal and mandibular planes and the gonial
angle was accompanied by anterior rotation of the mandible. The lower incisors
protruded, and upper and lower first molars exhibited a translation to
ventrocaudal. According to harmony box analysis, the most frequent cause of a
distal relationship between the 2 jaws was a disharmoniously anterior shift of
the maxilla. This was confirmed by the additional analysis of the available
unpublished raw data from untreated Norwegian and Munich Class II/1 subjects and
from other studies. In such cases, orthodontic treatment methods exerting a
growth-inhibitory effect on the maxilla should be used.
PMID- 10682409
TI - Facial profile and dental changes before, during and after treatment with
Hansaplate/Headgear.
AB - In this prospective study the changes of facial profile and dentition in 19 boys
and 19 girls treated for 1 year with Hansaplate/Headgear were analyzed yearly
over a 4-year period. On average the boys were 10.2 and the girls 9.2 years old
at the first recording, i.e., 1 year pretreatment. The actual values are compared
with standard growth data presented by Bathia and Leighton (1993). Irrespective
of the initial face morphology, the Hansaplate/Headgear appliance straightened
the facial hard and soft tissue profiles favorably. The upper lip became more
retruded while the lower lip was unaffected by therapy. During the 2-year post
treatment period these changes continued, probably as a consequence of growth.
The overjet was reduced by 5 mm during treatment and was found to be quite stable
2 years after treatment.
PMID- 10682410
TI - Axiographic evaluation of mandibular mobility in children with angle Class-II/2
malocclusion (deep overbite).
AB - Correction of the occlusion in Angle Class-II/2 patients is often more
complicated and tedious than in Class-II/1 cases. Reasons given are the more
comprehensive remodeling and functional adaptation processes of the
temporomandibular joints (TMJ) since the articular tuberculum is more strongly
developed in deep overbite, and a deep bite leading to a locked occlusion is
dominant due to the steeper condylar path. Both characteristics are, however,
considered to be the consequence of pronounced incisor retrusion. The present
study covered 28 untreated Class-II/2 patients aged 8 to 12 years in whom
functional TMJ adaptation to the retroclined maxillary incisors was studied with
the help of electronic, 3D axiographic registrations of mandibular movements.
Comparison with eugnathic age peers revealed increased mobility in mandibular
protrusion and a somewhat steeper condylar path, although the latter was less
pronounced than in adult patients. The results corroborate the concept of
functional TMJ adaptation to incisor inclination and speak for early uprighting
of maxillary incisors.
PMID- 10682411
TI - The influence of a 0.2% chlorhexidine mouthrinse on plaque regrowth in
orthodontic patients. A randomized prospective study. Part I: clinical
parameters.
AB - In a prospective plaque regrowth study focusing on oral hygiene during fixed
appliance therapy 12 adolescent patients (mean age 14.1 +/- 1.5 years) were
evaluated twice over 2-day test periods. In the randomized, double-blind study
the influence of a 0.2% chlorhexidine (CHX) mouthrinse (Corsodyl) and a
commercially available dentifrice supplementing fluoride (Odol-med-3) were
compared intra- and interindividually in a crossover design with regard to plaque
and gingivitis. Before starting the first test phase there was a 14-day
preliminary phase for upgrading the oral hygiene. Between the 2 test phases was a
5-day "washout". On the last day of the second test phase the patients were asked
to fill in a questionnaire concerning their experiences during the study. The
0.2% Corsodyl reduced the plaque index scores significantly (p < 0.001). The
gingival index revealed a similar reduction (2nd day of test: p = 0.03). Until
the 5th day of washout a clear-cut carryover effect of the chlorhexidine rinse on
the gingival index was observed. Both the lower mean values of the 2 clinical
parameters at the beginning of the test phases as compared with those at the
beginning of the preliminary phase and the evaluation of the questionnaires
indicated a possible Hawthorne effect. 0.2% Corsodyl may be employed as an
adjunct to other preventive measures such as professional care and patient
oriented instruction on an intermittent basis in order to reduce the plaque
induced iatrogenic side effects and to enhance the efficacy of oral hygiene
measures in connection with orthodontic therapy with fixed appliances.
PMID- 10682413
TI - MedBytes.
PMID- 10682412
TI - More tort reform is needed.
PMID- 10682414
TI - Insuring the children.
PMID- 10682415
TI - Measuring the mandates.
PMID- 10682416
TI - Living longer & better!
PMID- 10682417
TI - Traditions and transformations.
PMID- 10682418
TI - Telemedicine in Texas.
PMID- 10682419
TI - Area income as a predictor of preventable hospitalizations in the Harris County
Hospital District, Houston.
AB - This study assesses whether geographical area income based on census data is a
good predictor of preventable (or ambulatory care-sensitive) hospitalizations in
a large public hospital system in Texas, and how area income correlates with the
socioeconomic status reported by patients. Documenting a correspondence between
area and individual-level income, as well as meaningful variation in rates of
avoidable hospitalizations across subgroups and areas with varying concentrations
of low-income persons, points to the validity and utility of this approach for
monitoring how well public hospital systems in Texas address the needs of those
they most directly serve. Area income may not fully reflect the
disproportionately lower socioeconomic status of patients seen in the public
hospital system. Nonetheless, living in lower-income zip codes was associated
with higher preventable hospitalization rates for the predominantly low-income
population served by the public hospital system. A tenfold difference found in
the adjusted rates of hospitalizations for preventable conditions compared with
control (or marker) conditions among persons living in low-income areas signals
the likelihood of substantial unmet needs in this population. Small-area analysis
and related comparisons of rates of preventable hospitalizations in high- and low
income areas provide useful indicators for monitoring and assessing the
performance of public hospital systems in Texas.
PMID- 10682420
TI - [Study on the mechanism for fetal asphyxia in intrahepatic cholestasis of
pregnancy].
AB - OBJECTIVE: To investigate the cause of fetal asphyxia of mothers with
intrahepatic cholestasis of pregnancy (ICP). METHODS: The cord plasma
erythropoietin (EPO) concentrations were measured in 37 infants of mothers with
ICP and 46 control infants after elective cesarean section. Furthermore, the
transfer of oxygen across the placental membranes in ICP group (n = 7) were
compared with controls (n = 8) by dual perfusion of the human placental lobule in
vitro. RESULTS: The oxygen transfer across the placental membrane in ICP was
similar to the controls (P < 0.05). However cord venous EPO was lower in infants
delivered by elective cesarean section from women with ICP (13.58 +/- 8.88 IU/L,
P < 0.05) than that in control infants (20.43 +/- 14.15 IU/L). CONCLUSION: The
transfer of oxygen across the placental membrane in ICP may be normal. The lower
cord venous EPO value in ICP may be mainly responsible for the fetal asphyxia.
PMID- 10682421
TI - [Influence of prepregnancy weight and maternal weight gain on pregnancy outcome].
AB - OBJECTIVE: To determine the influence of weight before pregnancy and maternal
weight gain on pregnancy outcome. METHODS: Body wight index (BWI) was calculated
before pregnancy and maternal weight gain and pregnancy outcomes were followed up
in 2,584 primipara with singleton births. RESULTS: Compared with normal weight
women, the prevalences of pregnancy induced hypertension, operative deliveries
and high birth weight infants were significantly higher in women with heavy
weight, and prevalence of low birth weight infants was significantly higher in
women with lower weight. CONCLUSION: Prepregnancy weight and weight gain during
pregnancy have direct impact on birth weight of the baby and maternal
complications.
PMID- 10682422
TI - [Detection and enrichment of fetal cells in maternal circulation for prenatal
diagnosis of fetal sex].
AB - OBJECTIVE: To study fetal cells from maternal peripheral blood for prenatal
diagnosis of fetal sex. METHODS: Samples of peripheral blood in 64 women of 8-40
gestational weeks were collected to enrich the fetal nucleated red blood cells by
density gradient centrifugation. DNA was extracted from each samples of enriched
fetal cell for PCR amplification of Y chromosome specific DNA to determine fetal
sex. RESULTS: Fetal nucleated red cells were found in 25 out of 64 maternal
samples (39.06%). Y chromosome 149 bp was found in 28 cases of the 33 mothers
given birth to male babies. One Y specific DNA sequence was detected in 31 women
had female babies. The sensitivity was 84.85% and specificity 96.77%. The overall
agreement of the diagnosis was 90.63%. CONCLUSION: Density gradient
centrifugation can enrich fetal nucleated red blood cells from maternal
peripheral blood. Fetal sex can be determined by PCR amplification of Y
chromosome specific DNA with these fetal cells.
PMID- 10682423
TI - [Immuno-pathomorphological study of placenta with anticardiophospholipid antibody
positive].
AB - OBJECTIVE: To investigate the relationship between the anticardiophospholipid
antibody (ACA)-positive cases and the poor pregnancy outcomes by observing the
immuno-pathomorphology of the placenta. METHODS: 16 cases of ACA-positive
placenta (8 normal and 8 poor pregnancy outcomes) were collected as the studied
group, and 8 cases of ACA-negative placentas served as the controlled group, and
immunofluorescence technique (IFT) was used. RESULTS: In the studied group, the
deposits of immuno-complex were found in the cytoplasm of trophoblast and on the
walls of villous blood vessels. IgA manifested as filiform, and IgG, IgM, C3 and
C4 appeared as filiform, granular and tubercular as well. In contrast, all the
immuno-globulins displayed negative reaction in the controlled group, and C4
demonstrated some small focal positive reaction. The frequency of ACA-positive in
IUGR cases were 19.30% (22/144), and of the IUGR in all the ACA-positive pregnant
women was 15.28%(22/144). There were 3 cases of IUGR complicated by severe
pregnancy induced hypertension, 2 cases of prematurity and 5 newborns with serum
ACA IgG positive. CONCLUSION: The poor pregnancy outcome in ACA-positive women is
related to the dysfunction of autoimmuno-system, and ACA-positive may be one of
the causes of IUGR. The immuno-injury occurred in the placenta may affect the
normal function of placenta. Maternal antibody may be transmitted to the fetus,
and its significance needs further study.
PMID- 10682424
TI - [Changes of carbohydrate metabolism in normal pregnancy and its relationship with
placental lactogen concentrations].
AB - OBJECTIVE: To observe the changes of glucose metabolism and its relationship with
human placental lactogen (HPL) in normal pregnant women. METHOD: 94 normal
pregnant women had their serum HPL concentration tested and had undergone a 75 g
oral glucose tolerance tests (OGTT). Both serum insulin and glucose levels at
different time intervals were determined, and the areas under curve (IAUC, GAUC)
were caculated, also insulin resistance (IAI) was evaluated. RESULTS: GAUC, IAUC,
IAI and HPL are all significantly increased with advance of gestation (P < 0.05).
Multiple correlation coefficient study demonstrated that HPL is significantly
positively correlated with GAUC, IAUC and IAI(P < 0.001). But when IAUC and IAI
were controlled, the relationship between HPL and GAUC was not found. CONCLUSION:
There are hyperinsulinemia and insulin resistance during pregnancy, and they are
related to HPL. HPL is one of the factors that contributing to carbohydrate
metabolism changes during pregnancy.
PMID- 10682425
TI - [Study on a deletion polymorphism of the angiotensin converting enzyme gene in
pregnancy induced hypertension].
AB - OBJECTIVE: To study a polymorphism and allele frequency of the angiotensin
converting enzyme (ACE) gene in pregnancy induced hypertension (PIH). METHODS:
Polymerase chain reaction (PCR) for detection of ACE gene polymorphism was
performed to show the deletion/insertion (D/I) polymorphism in intron 16 of ACE
gene. A 490 bp(I) and 190 bp(D) PCR products were identified, corresponding to
the PCR amplification of the the allele with or without the insertion. RESULTS:
Derived allele frequencies for insertion and deletion were the different between
35 PIH and 25 control subjects. Compared the frequency of D allele gene (0.76)
and the percentage of the ACE DD genotype (65.7%) in the PIH patients with the
frequency (0.28) and the percentage (8.0%) in the control population, they were
significant higher in individuals with PIH (P < 0.001). CONCLUSIONS: There was an
excess of DD genotype and the frequency of D allele gene in PIH, confirming the
genetic variation in the ACE locus could be involved in the risk of PIH and
suggesting the ACE gene may contribute to the pathogenesis of PIH.
PMID- 10682426
TI - [A study on the relationship between serum anticardiolipin antibody and embryo
implantation in an in vitro fertilization and embryo transfer program].
AB - OBJECTIVE: To study the role of serum anticardiolipin antibody in embryo
implantation in an in-vitro fertilization and embryo transfer program. METHODS:
150 in vitro fertilization and embryo transfer (IVF-ET) treatment cycles from
Nov. 1994 to May, 1996 were studied. Serum anticardiolipin antibody was measured
by enzyme-linked immunosorbent assay (ELISA), and the clinical pregnancy outcome
observed. RESULTS: Lower pregnancy rate 9.5% was found in 21 cycles of
anticardiolipin antibody seropositive women compared with 26.3% in 129 cycles of
anticardiolipin antibody seronegative women (P < 0.05). Patients with biochemical
pregnancy and no pregnancy had seropositive anticardiolipin antibody in 20.0% and
16.2% compared with 5.6% in the patients with clinical pregnancy (P < 0.05).
CONCLUSIONS: Failure of embryo implantation is associated with many factors. Our
study demonstrated the serum anticardiolipin antibody in patients may play a part
in embryo implantation and very early postimplantation loss.
PMID- 10682427
TI - [Pathological and immunohistochemical study on estrogen and progesterone
receptors in endometrium of polycystic ovarian syndrome].
AB - OBJECTIVE: To investigate the changes of endometrium in infertility patients with
polycystic ovarian syndrome (PCOS). METHODS: The endometrium from 39 patients
with PCOS were studied by HE stain and immunohistochemical method using anti
estrogen receptor(ER) and anti-progesterone receptor(PR) monoclonal antibodies.
RESULTS: 87.2% (34/39) of the endometrium showed anovulatory proliferative
phases; 51.3% (20/39) had signs of hyperplasia; 35.9% (14/39) showed
asynchronization of endometrial glands and 46.2% (18/39) poor response of stroma
to sex hormone. The levels of ER and PR in endometrium during proliferative phase
were significantly higher than those of normal control, and the PR in the stroma
of hyperplasia endometrium had an uneven distribution and was significantly less
than that in the control group (P < 0.05). CONCLUSIONS: The endometrial
histopathological changes and local decrease or absence of ER and PR in PCOS
might be one of the causal factors of infertility.
PMID- 10682428
TI - [The clinical value of tissue polypeptide antigen in ovarian carcinoma].
AB - OBJECTIVE: To evaluate the clinical usefulness of tissue polypeptide antigen
(TPA) in diagnosis and monitoring the course of patients with ovarian carcinoma.
METHODS: Serum levels of TPA and cancer antigen 125 (CA125)were measured by
radioimmunoassay in 60 patients with advanced ovarian carcinoma (41 with active
disease and 16 with nonactive, 3 with metastatic tumor from gastrointestinal
carcinoma), 24 healthy women and 27 benign gynecologic tumors. RESULTS: The serum
TPA and CA125 levels were elevated in 82% and 70% of patients with ovarian
carcinoma respectively, the total positive rate of the two markers was 92%. TPA
and CA125 levels were within normal range among most of healthy women and
patients with benign tumors. TPA and CA125 levels were also correlated with the
regression or progression of the disease. CONCLUSION: Combined measurement of TPA
with CA125 was useful for the differential diagnosis and achieving higher
positivity in patients with epithelial ovarian carcinoma.
PMID- 10682429
TI - [The expression of glutathione S-transferase pi in human ovarian cancer as an
indicator of resistance to chemotherapy].
AB - OBJECTIVE: To study the relationship between the expression of glutathione S
transferase pi (GST-pi) in cancer tissue and the chemoresistance in patients with
ovarian carcinoma. METHODS: The expression of GST-pi in 53 cases of ovarian
cancer, 20 ovarian benign tumors and 17 normal controls was determined by using
immunohistochemical SP method and the results were studied in correlation with
some clinical and pathological data. RESULTS: (1) Positive expression with GST-pi
was demonstrated in 60.4% of malignant and 10.0% of benign ovarian tumors while
the expression was negative in normal controls. (2) No significant difference for
the expressions was shown in relation to the histopathology, the clinical staging
and the size of residual tumors after cytoreductive surgery. (3) The positive
rate of the expression was 47.2% (17/36) for the initially treated patients while
those with tumor recurrence had a positive rate of 88.2% (15/17). (4) GST-pi
positive cases showed less response rate of 37.5% (12/32) to chemotherapy as
compared with that of 76.2%(16/21) for GST-pi negative cases. (5) The survival
period of the patients with GST-pi positive expression was shorter than that of
those with GST-pi negative expression. CONCLUSION: The expression of GST-pi in
patients with ovarian carcinoma in closely related to the chemosensitivities
clinically. Determinations of the GST-pi are useful for predicting the
chemosensitivities and the prognosis of the disease.
PMID- 10682430
TI - [Relation between HLA antigen system and pathological pregnancies].
PMID- 10682431
TI - [Prevention and treatment of pregnancy-complicated tuberculosis].
PMID- 10682432
TI - [Ovarian cancer treated with very-high-dose chemotherapy and peripheral
hematopoietic stem cell transplantation].
PMID- 10682433
TI - [Detection of human papillomavirus infection in cervical Pap smears by computer
assisted cytologic test].
AB - OBJECTIVE: The sensitivity and accuracy of cytologic computer-assisted test (CCT)
in diagnosis of human papillomavirus (HPV) infection in cervical Pap smear were
evaluated. METHODS: Cervical Pap smears obtained from 158 patients with vulva
condyloma acuminata were examined by CCT. The diagnostic criteria were based on
The Bethesda System (TBS). Simultaneously HPV DNA in cervical mucus was examined
by polymerase chain reaction (PCR) technique and cervical biopsy taken under the
guidance of colposcopy for pathological examination. RESULTS: The sensitivity and
accuracy of CCT in diagnosis of cervical HPV infection were 74.62% and 67.72%
compared with pathological results whereas 69.11% and 70.88% compared with PCR
results respectively. CONCLUSION: The results indicates that CCT, a cytologic
pathological technique, is a useful method in diagnosis of clinical and
subclinical cervical HPV infection.
PMID- 10682434
TI - [The evaluation of computer cytological test with colposcopy for the diagnosis of
cervical lesions].
AB - OBJECTIVE: To assess the value of computer cytological test (CCT) with colposcopy
for the diagnosis of early cervical diseases. METHODS: 3,016 cervical pap smears
have been done in our hospital from March 15, 1995 to March 15, 1996. The CCT
smears were analyzed first, then cytologist made the final reports, cervical
biopsies under the guidance of colposcopy were taken in 56 cases with abnormal
findings. RESULT: We found 375 (12.4%) abnormal pap smears out of 3,016 cases, in
which cervical squamous cancer 5 cases, endometrium adenocarcinoma 1 case. The
low grade squamous intraepithelial lesion (LSIL) and human papilloma virus (HPV)
infection most frequently happened at the younger patients. There are 59 cases
(2.0%) of LSIL, among which HPV infection accounted 79.7%. We use CCT for primary
selection, its sensitivity is 98.9% specificity is 90.9%. CONCLUSION: Sexually
transmitted diseases is closely related to cervical early disease. CCT should be
done in the younger women, especially high-risk patients. Positive cases of CCT
must be examined by colposcopy and pathological biopsy, this is the best way to
diagnosis cervical disease.
PMID- 10682435
TI - [Effects of mifepristone on proliferation and apoptosis in early chorionic
villi].
AB - OBJECTIVE: To study the effects of mifepristone on proliferation and apoptosis in
early pregnant chorionic villi. METHODS: Proliferation and apoptosis in early
pregnant choionic villi from surgical aspiration and mifepristone induced
abortion were studied. Marker for proliferation is proliferating cell nuclear
antigen (PCNA) immunohistochemical staining, apoptotic cell death was detected
using DNA in situ terminal deoxynucleotidyl transferas-mediated dUTP-biotin nick
ending labeling (TUNEL). RESULTS: In early pregnant chorionic villi,
proliferating index of cytotrophoblasts was 53.74% +/- 1.34%, not only nuclear
but also cytoplasma were PCNA positive staining, syncytiotrophoblasts were
negative. There existed apoptotic cell death in trophoblasts, the apoptotic index
were 2.52% +/- 0.86% in syncytiotrophoblasts and 0.52% +/- 0.26% in
cytotrophblasts, respectively. After 2 days mifepristone treatment, the
proliferating index of cytotrophoblasts decreased slightly and PCNA positive
cytoplasmic expression disappeared; while apoptotic cell increased significantly,
the apoptotic indices were 22.16% +/- 2.26% in syncytiotrophoblasts and 20.12% +/
1.74% in cytotrophoblasts, respectively. CONCLUSION: Mifepristone may inhibit
proliferation and promote apoptosis of trophoblasts in early pregnant chorionic
villi.
PMID- 10682436
TI - [Effect of mifepristone on the concentration of epidermal growth factor in serum
and villi of early pregnant women].
AB - OBJECTIVE: To investigate the change of epidermal growth factor (EGF)
concentration in serum and villi of early pregnant women and its possible effects
by mifepristone. METHODS: Twenty normal women as control and sixty-six early
pregnant women were enrolled for study. Serum EGF, estradiol (E2) and
progesterone (P) concentrations were measured with radioimmunoassay. EGF
concentration in villi by surgical aspiration and mifepristone induced abortion
were compared. RESULTS: Serum EGF concentration in early pregnant women was
significantly higher than that in non-pregnant women (P < 0.01). The serum EGF,
E2 and P concentrations increased as pregnancy advanced (P < 0.05). The growth
rate of gestational sac declined and serum EGF and P concentrations decreased
slightly after administration of mifepristone. Villi EGF content in mifepristone
group was significantly lower than that in surgical group (P < 0.05). CONCLUSION:
EGF may be involved in regulating embryo development. Mifepristone may interfere
embryonic development via inhibiting EGF level.
PMID- 10682437
TI - [A study on the relationship between hemorheology of pregnant women with
pregnancy induced hypertension and hemodynamics of fetal umbilical artery blood
flow].
PMID- 10682438
TI - [Ultrasonic measurements of fetal thigh soft tissue thickness in the estimation
of fetal weight].
AB - OBJECTIVE: To study ultrasonic measurement of fetal thigh soft tissue thickness
in the estimation of fetal weight. METHODS: Fetal biparietal diameter (BPD), head
circumference (HC), abdominal circumference (AC), femur length (FL) and fetal
thigh soft tissue thickness (FTSTT) were measured by ultrasonography and analyzed
with neonatal birth weight in 178 cases. RESULTS: There was significant
correlation between FTSTT and neonatal birth weight (r = 0.8601), and it is
better to estimate fetal weight with FTSTT than with the other parameters. The
sensitivity and specificity for detection of macrosomia was 91% and 94%,
respectively. The FTSTT was positively correlated with gestational age (r =
0.7070). CONCLUSION: The ultrasonic measurement of FTSTT is a simple, accurate
and valuable index in estimation of fetal weight.
PMID- 10682439
TI - [Effects of human chorionic gonadotropine and insulin on androgen production by
cultured thecal cells from patients with polycystic ovary syndrome].
PMID- 10682440
TI - [Application of multi-tumor markers in ovarian carcinoma].
AB - OBJECTIVE: To improve the specificity and sensitivity of diagnosis and to
strengthen postoperative monitoring for patients with ovarian cancer. METHODS:
Sera obtained from patients-ovarian epithelial carcinoma (67 cases), benign
ovarian tumor (33 cases) and from donor (38 cases) as control. Serologic
examination of 5 tumor markers--SA, LSA, CA125, CP2, and 6B11Ab2 was performed.
RESULTS: The sensitivity and specificity in diagnosis of ovarian cancer were
83.6% and 85.9% respectively for CA125 alone (> 35 kU/L) whereas 86.6% and 94.4%
respectively for multi-tumor markers combined in which 3 or more indices showed
positive. In addition, serial measurements of multi-tumor markers have been done
for 1 year after operation in 24 cases of ovarian epithelial carcinoma. The
correlations between the levels of multi-tumor markers either and the results of
second look operation or and clinical manifestation of recurrence were analyzed.
CONCLUSION: Multi-tumor markers examination could improve the diagnosis of
ovarian cancer and early detection of recurrence.
PMID- 10682441
TI - [Study on multidrug resistant gene (MDR1) expression between neoplastic cells and
peripheral blood lymphocytes in ovarian carcinoma].
AB - OBJECTIVE: To explore the correlation of MDR1 (P-glycoprotein, P170) gene
expression P170 contents among neoplastic tissues, peripheral blood lymphocytes
(PBL) and ascites cancerous cells (ACC) during chemotherapy. METHODS: Content of
P170 in cancer tissue, ACC and PBL was quantiated dynamicly by using flow
cytometric-immunologic method in 48 cases suffered from ovarian carcinoma.
RESULTS: Cancer tissue showed positive P170 in 25% of patients. During
chemotherapy, P170 content in PBL and ACC were statistically increased. A
significant correlation of P170 was found between PBL and ACC (0.01 < P < 0.05).
CONCLUSION: The results indicated that multidrug resistance was produced
gradually during chemotherapy. Content of P170 in PBL could probably be used as
an indirect index of multidrug resistance for recurrent carcinoma or residual
tumor.
PMID- 10682442
TI - [A clinicopathological analysis of 15 cases with congenital tumors in fetus and
newborn].
AB - OBJECTIVE: The incidence rate of congenital tumors in fetuses and neonates and
its influence on fetal outcome including development and death were analysed.
METHODS: Both clinical manifestations and pathological data of 15 cases with
congenital tumor were analysed retrospectively. RESULTS: The incidence rate of
congenital tumors in fetuses and neonates was 7.7/100,000 with a rate of 0.7% in
total perinatal autopsies. The most common tumor was teratoma (46.7%), the next
was hemangioma (26.7%). Among 15 cases with congenital tumor, 9 cases (60.0%)
were complicated with polyhydroamnios; 11 perinates (73.3%) were born with body
weight appropriate for gestational age, 6 perinates (40.0%) were associated with
various anomalies which were commonly secondary to the tumors. The common causes
responsible for death were malformation, placental impairment due to tumor
invasion or tumor grown at a special site. CONCLUSION: The incidence rate of
congenital tumors in fetuses and neonates was very low. Because the tumor usually
exhibited a local effect, under carefully evaluating the development of neonates,
it is promising to get complete cure.
PMID- 10682443
TI - [Advances in the mass screening of Down's syndrome in early and middle stages of
pregnancy].
PMID- 10682444
TI - [Risk factors for fallopian tube pregnancy].
PMID- 10682445
TI - [Inhibin and ovarian neoplasms].
PMID- 10682446
TI - [Advance in reproductive immunology].
PMID- 10682447
TI - [The role of decidua tissue lymphocytes in early pregnancy].
AB - OBJECTIVE: To investigate the role of lymphocytes in early pregnancy decidua
tissue. METHODS: Immunohistochemical and in situ hybridization techniques were
employed to demonstrate the population, phenotype and mediator of lymphocytes in
early pregnancy decidua. RESULTS: In early pregnancy decidua, CD8+
suppressor/cytotoxic T lymphocytes were very few. CD4+ helper lymphocytes were
few and CD56+ lymphocytes (also named NK-like cell) were abundant. CD56+
lymphocytes containing perforin protein and expressing perforin mRNA were
observed. CONCLUSIONS: The lymphocytes in early pregnancy decidua are specific
and may play an important role in early pregnancy. They probably exert some
positive influence on embryo implantation and placental development, and maintain
the balance between trophoblastic cells and decidua tissue.
PMID- 10682448
TI - [Relationship between pregnancy loss and antiphospholipid antibody].
AB - OBJECTIVE: To investigate the relationship between history of pregnancy loss and
antiphospholipid antibodies (APA), including anticardiolipin (ACA) and lupus anti
coagulant antibodies (LA). METHODS: Levels of serum APA, ACA and LA were
determined by enzyme linked immunoabsorbent assay and activated partial
thromboplastin time method respectively in 122 patients with history of
unexplained pregnancy loss (study group) and 100 normal nonpregnant women
(control group). The study group was further divided into three subgroups: embryo
growth arrest (n = 23), stillbirth (n = 31), and recurrent abortion (n = 63).
RESULTS: The positive rates of APA, ACA, LA in the study group were significantly
higher than those in controls (P < 0.05-0.001). The above significance was true
in both stillbirth and recurrent abortion groups but not in embryo growth arrest
group. CONCLUSIONS: Levels of serum APA were associated with pregnancy loss,
especially recurrent abortion and stillbirth. We suggested routine screening of
serum APA should be performed in patients with history of fetal wastage for the
sake of early treatment.
PMID- 10682449
TI - [The study of autoantibodies in women with habitual abortion of unknown
etiology].
AB - OBJECTIVE: To evaluate the relationship between habitual abortion of unknown
etiology and autoantibodies. METHODS: IgG and IgA antibodies against cardiolipin,
specific antinuclear double-stranded DNA and single-stranded DNA were measured by
enzyme linked immunosorbent assay (ELISA). Antinuclear antibody, smooth muscle
antibody, antimitochondrial antibody and antiheart muscle antibody were performed
by indirect immunofluorescence assay. Antiextractable nuclear antigen's
antibodies were determined by immunodiffusion assay. RESULTS: Most women with
habitual abortion of unknown etiology showed higher incidence of antibodies to
cardiolipin, nuclear, smooth muscle compared with normal multigravida control (P
< 0.05). CONCLUSIONS: These results indicate that most women with habitual
abortion of unknown etiology have a higher level of autoreactivity, which may
affect the course of pregnancy. The incidence of antismooth muscle antibody in
women with habitual abortion of unknown etiology is also increased compared with
normal multigravida control.
PMID- 10682450
TI - [Alteration of peritoneal lymphocyte transformation and its interleukin-2 release
in patients with infertility and endometriosis].
AB - OBJECTIVE: To study the relationship between alteration of peritoneal lymphocyte
transformation activity, its interleukin-2 (IL-2) release and infertility
associated with endometriosis. METHODS: Peritoneal fluid was collected from 15
infertile patients with endometriosis (endometriosis group) and 13 normal fertile
women (control group). Lymphocyte transformation activity were determined in
peritoneal fluid by morphometry. IL-2 contents were determined in peritoneal
fluid and supernatants of cultured pelvic lymphocytes by biological method.
RESULTS: Lymphocyte transformation activity reinforced (P < 0.001) and IL-2
contents increased in peritoneal fluid and supernatant of cultured pelvic
lymphocyte in the endometriosis group than those in the control group (P < 0.01,
P < 0.001 respectively). There is significant positive correlation between
lymphocyte transformation rate and IL-2 activity of cultured supernatant in
endometriosis group (P < 0.001). CONCLUSION: The increase of IL-2 content in the
samples of endometriosis may play an important role in infertility with
endometriosis.
PMID- 10682451
TI - [Experimental study of effects of anti-ovarian antibodies on ovarian histology
and function].
AB - OBJECTIVE: To investigate the effects of anti-ovarian antibodies (AOA) on ovarian
histology and functions. METHODS: Rabbit antibodies against mice ovarian tissues
were obtained by immunizing with mice ovarian extracts and purified. The effects
of AOA on mice ovarian histology were examined under light and electronic
microscope. In addition, changes of ovarian functions, including natural pregnant
rate and pregnant mare serum gonadotropin (PMSG) + hCG induced ovulation rate and
pregnant rate, were also observed. RESULTS: After treating with different doses
of AOA pathological changes occurred in a variety of ovarian components,
especially in zona pellucida and granulosa cells, which is more serious in high
AOA level group than that in low AOA level group. The natural pregnant rate
decreased to zero in both AOA groups. The ovulation and pregnant rate induced by
PMSG-hCG were significant lower in both AOA groups than that in the control group
especially in the high AOA level group. CONCLUSION: AOA may damage the ovarian
tissues and reduce the ovulation and pregnant rate. The higher the AOA level, the
more serious pathological changes and the poorer curative effects of PMSG-hCG may
occur.
PMID- 10682452
TI - [The study on relationship between fetal blood flow velocity waveforms and cord
blood gas analyses in normal full term pregnancy].
AB - OBJECTIVE: To study the relationship between fetal blood flow velocity waveforms
and cord blood gas values in normal full term pregnancy. METHODS: Fetal umbilical
artery (UA) and middle cerebral artery (MCA) and abdominal aorta (AbAo) flow
velocity waveforms were measured in 45 full term fetuses 24 hrs before selective
cesarean section. Resistance index (RI) and pulse index (PI) were calculated,
cord blood samples were obtained from the umbilical artery at cesarean section
and blood gas values were measured immediately. RESULTS: (1) UA RI had a
significant negative correlation with pH and PO2, and a positive correlation with
PCO2. (2) MCA RI had a significant positive correlation with pH and PO2, and a
negative correlation with PCO2. CONCLUSION: A Doppler study of fetal blood flow
velocity waveforms would be a useful method in the evaluation of the fetal status
in the uterus.
PMID- 10682453
TI - [Lipoprotein lipids in polycystic ovarian syndrome: independent associations with
androgen excess and insulin resistance].
AB - OBJECTIVE: To investigate the relationship between androgen excess, insulin
resistance and altered lipoprotein lipids in polycystic ovarian syndrome (PCOS).
METHODS: Both basal and luternizing hormone-releasing hormone (LHRH, 100
micrograms) induced responses of circulating testosterone (T), triglycerides
(TG), high-density lipoprotein-cholesterol (HDL-C) and apoprotein A1 (apo A1)
were measured in two PCOS groups with similar T levels (LH/FSH > or = 3, Group 1,
n = 15, LH/FSH < 3, Group 2, n = 15) and the control (n = 20) of matched body
mass index with Group 1. Insulin resistance was assessed by fasting insulin
levels. RESULTS: In basal state, the mean TG levels in women of three groups were
as follows: Group 2 > Group 1 > control, while HDL-C showed the opposite. After
LHRH test, mean T and TG concentrations increased and HDL-C decreased in all PCOS
subjects, especially Group 2 whereas the indices remained unchanged in the
controls. CONCLUSION: Our data suggest that altered lipid profiles in women with
PCOS may result from the independent effects of androgen excess and insulin
resistance.
PMID- 10682454
TI - [Influences of sperm quality and quantity on fertilization, cleavage rates and
quality of embryos in in-vitro fertilization].
AB - OBJECTIVE: To examine the influences of the quality and quantity of seminal sperm
and inseminational sperm on in-vitro fertilization (IVF) outcomes. METHODS: chi
square tests were used to analyze the impacts of both semen and inseminated sperm
concentrations and percentages of different grade motile sperm on the
fertilization rates in 481 matured and 273 immatured oocytes and cleavage rate
percentage of embryo with low quality in embryos obtained from 92 IVF-embryo
transfer cycles. RESULTS: The fertilization rates of both kinds of oocytes and
cleavage rate of fertilizaed matured oocyte significantly decreased (P < 0.05) as
the concentrations and percentages of grade a and b sperms in semen reduced. The
rates of embryos with abnormal morphology were significantly dropped when the
above sperm parameters increased (P < 0.05). Meanwhile, it was also found that
the concentration and motility of inseminated sperm could also affect the above
three IVF parameters significantly (P < 0.05). CONCLUSION: Highly active semen
and inseminated sperm play important roles not only in fertilization, but also in
cleavage and embryo development during IVF procedure.
PMID- 10682455
TI - [Comparative study of tetracycline-estrone and estrone effects on bone
histomorphometric parameters in ovariectomized rats].
AB - OBJECTIVE: To compare the effects of tetracycline-estrone (TE) and estrone (E) on
bone histomorphometric parameters of femoral distal diaphysis in ovariectomized
(OVX) rats. METHODS: Twenty female rats were randomly allocated into four groups,
5 rats in each: tetracycline-estrone (TE), estrone (E), OVX and sham operation
(S). The OVX rats were used as a model for osteoporosis. After being fed with TE
or E for 13 weeks, all rats were sacrificed. The effects of TE and E on bone
microarchitecture and dynamics were studied by bone histomorphometry. RESULTS:
The histomorphometric data showed that the connectivity of trabecular bone in TE
and E groups was significantly improved in comparision with that in S group (P <
0.05). The dynamic data indicated that in TE and E group, the tetracycline
labelled and osteoid surfaces were remarkably increased in comparision with those
in OVX group, especially the data in TE group were significantly higher than
those in E group and other two groups (P < 0.05). CONCLUSIONS: The connectivity
of trabecular bone could be significantly improved by both TE and E. The
activation frequency seemed to be higher in TE group than that in E group.
PMID- 10682456
TI - [Treatment of 129 patients with advanced and recurrent malignant ovarian germ
cell tumor].
AB - OBJECTIVE: To investigate the improved treatment for advanced malignant germ cell
tumors of the ovary. METHODS: 129 patients with advanced and recurrent germ cell
tumor of the ovary treated from 1958 to 1993 were retrospectively analyzed. The
results of malignant nondysgerminomatous germ cell tumor of the ovary treated
from 1958-1983 were compared with those treated with the supplement of VAC
(Vincristine + ActinomycinD + Cyclophosphamide), PVB (Cisplatin + Vinblastine +
Bleomycin) or BEP (Bleomycin + Etoposide + Cisplatin) combined chemotherapy from
1984-1993. RESULTS: The overall 5-year survival rate was 30% (39/129) of advanced
and recurrent germ cell tumor of the ovary. The 5-year survival rates of
dysgerminoma and nondysgerminomatous germ cell tumor of the ovary were 68%
(19/28) and 20%(20/101), respectively. The 5-year survival rate of patients with
malignant nondysgerminomatous germ cell tumor of the ovary was raised from 3%
(1/40) to 42% (15/36) in the recent years. The institution of combination
chemotherapy is critical for the improvement with BEP regimen as the best among
the three. CONCLUSIONS: The endodermal sinus tumor of the ovary stands first in
the incidence of malignant germ cell tumors of the ovary in China. To improve the
prognosis of advanced malignant germ cell tumor of the ovary, BEP regimen is the
most effective at present.
PMID- 10682457
TI - [Effects of mifepristone on gene expression of epidermal growth factor in human
uterine leiomyoma].
AB - OBJECTIVES: To study the effects of mifepristone on epidermal growth factor gene
expression in human uterine leiomyoma. METHODS: 20 patients with leiomyoma were
divided into two groups. One was control group who underwent hysterectomy because
of leiomyoma, the other was experimental group who underwent hysterectomy after
pretreatment with mifepristone 10 mg/daily for 3 months. Epidermal growth factor
(EGF) mRNA was semiquantified in samples of leiomyoma and adjacent normal
myometrium from patients untreated in different phases of menostrual cycle and
from those treated with mifepristone. Semiquantitative reverse transcriptase
polymerase chain reaction, using beta-actin as internal standard, was applied to
determine levels of EGF mRNA. RESULTS: Leiomyoma untreated with mifepristone had
significantly greater amounts of EGF mRNA than adjacent normal myometrium of
uterus only in the luteal phase, but not in the follicular phase of cycle.
Similarly, leiomyoma untreated with mifepristone also had significantly larger
amount of EGF mRNA than treated leiomyoma in the luteal phase of the cycle,
whereas, no difference in the follicular phase of the cycle. CONCLUSION: These
findings suggested that: (1) EGF mRNA levels in leiomyoma were increased only in
the luteal phase, therefore, maybe mainly controlled by progesterone; (2)
mifepristone inhibited EGF gene expression in leiomyoma. This may be one of
regression mechanism of uterine leiomyoma in response to the antiprogesterone
mifepristone.
PMID- 10682458
TI - [The influence of immediate postpartum insertion of GyneFix PP-intrauterine
devices on puerperal period].
AB - OBJECTIVE: To investigate the effects of immediate postpartum insertion of
GyneFix PP-intrauterine devices (IUD) on postpartum hemorrhage, bloody lochia and
postpartum endometritis. METHODS: 126 women had GyneFix PP-IUD inserted
immediately postpartum (IUD group) and another 118 cases with no IUD insertion
were served as control. Blood loss during delivery, 2 and 24 hours after delivery
were determined, the time of bloody lochial lasted and the incidence of
postpartum endomeritis were recorded. RESULTS: There were no significant
differences in the blood loss during and after delivery, and the incidence of
endometritis between the 2 groups, but the bloody lochia was lasted significantly
longer in the IUD group (P < 0.05). CONCLUSION: This results suggested that the
immediate postpartum insertion of the GyneFix PP-IUD is a safe and good
postpartum contraceptive method, and the cause of prolonging bloody lochia awaits
for further study.
PMID- 10682459
TI - [Clinical uses of misoprostol in obstetrics and gynecology].
PMID- 10682460
TI - [Clinical uses of goserelin in gynecologic diseases and its safety].
PMID- 10682461
TI - [The changes of maternal and umbilical serum nitric oxide in patients with
pregnancy induced hypertension].
AB - OBJECTIVE: To determine whether levels of maternal and umbilical serum nitric
oxide (NO) were changed in patients with pregnancy induced hypertension (PIH).
METHODS: 40 women with PIH, 40 normal late trimester pregnant women and 20
nonpregnant women were studied. Maternal venous blood were collected from all the
cases and umbilical venous blood were collected from 28 of the first two groups
respectively. Serum NO2-/NO3-, the endproducts of NO, were measured with the
Griess reaction after reduction with nitrate reductase. RESULTS: The mean NO2
/NO3- in maternal venous serum were 23.30 +/- 5.60 mumol/L in nonpregnant group,
26.42 +/- 4.54 mumol/L in normal pregnant group and 32.58 +/- 5.06 mumol/L in PIH
group. Umbilical serum NO2-/NO3- were 12.26 +/- 4.91 mumol/L in normotensive
groups and 14.64 +/- 3.90 mumol/L in PIH group. Maternal serum NO2-/NO3- in
nonpregnant group were lower than that both in normal pregnant group (P < 0.05)
and in PIH group (P < 0.01). Compared with the normotensive group, maternal serum
NO2-/NO3- in PIH group was significantly higher (P < 0.01), while significantly
higher serum NO2-/NO3- were also found in umbilical venous blood in PIH group (P
< 0.05). There were no correlations between serum NO2-/NO3- level and blood
pressure or birth weight. The total nitrite levels in fetal circulation was lower
than that in maternal circulation in both pregnant groups (P < 0.01). CONCLUSION:
Total nitrites are increased both in maternal and fetal circulation in PIH. The
result indicates that the increase of NO may be secondary compensative reaction
in PIH.
PMID- 10682462
TI - [Study on the activity of platelets protein kinase C in patients with pregnancy
induced hypertension].
AB - OBJECTIVE: To investigate the relationship between the activity of protein kinase
C (PKC) in plateletes and patients with pregnancy induced hypertension (PIH).
METHOD: Activities of PKC in membrance of platelets, which came from 18 PIH
patients(PIH group), 20 normal pregnant women (normal pregnant group) and 20
healthy women (control group), were measured by substrate protein phosphoylation
method. RESULTS: Activities of PKC in the membrane and cytosolic of platelets
from normal pregnancie are lower than those from control group significantly (P <
0.01). Activities of PKC in the membrane and cytosolic of platelets from PIH
group are higher than those from normal pregnancie (P < 0.05). Activity of PKC in
membrane of platelets from mild and moderate PIH group is higher than that from
normal pregnancie (P < 0.01). However, there is no difference between the
activities of PKC in cytosolic of platelets from the two groups (P > 0.05).
Activities of PKC in membrane and cytosolic of platelets from severe PIH were
higher than those from normal pregnancie significantly (P < 0.01, P < 0.05). We
also found that the activity of PKC in cytosolic of platelets from severe PIH
group was significantly higher than that from mild and PIH cases, though there
was no significantly difference in the activity of PKC in membrane of platelets
between the two groups. CONCLUSION: Activity of PKC in platelets relates to the
occurrence and development of PIH syndrome.
PMID- 10682463
TI - [Expectant treatment of placenta previa with ritodrine].
AB - OBJECTIVE: To investigate the effectiveness of the expectant treatment in
placenta previa with adrenergic agonist ritodrine. METHODS: 50 women with
placenta previa of preterm labor were randomly assigned into two groups. 26
patients treated with magnesium sulfate were served as control group. 24 patients
were enrolled in the study group, receiving ritodrine 100 mg in 5% glucose 500 ml
intravenous. The drip speed was started at 8 drips per minute routinely, then
adjusted according to the treatment response, and oral ritodrine was used after
vaginal bleeding and uterine contraction disappeared 12 hours. If contraction
reappeared, the i.v. infusion would be restarted. RESULTS: The study group
prolonged the gestational period to an average of 28.24 days and increased the
birth weight of newborn to an average of 2,913.68 g (P < 0.05). CONCLUSION:
Ritodrine is highly effective and safe for expectant treatment of placenta
previa.
PMID- 10682464
TI - [Clinical experience with iron supplementation in pregnancy].
AB - OBJECTIVE: To study the efficacy of iron supplementation during pregnancy and its
influences on the outcome of pregnancy. METHODS: A total of 369 pregnant women
were enrolled in this study. According to the hemoglbin levels at recruitment,
there were 2 groups: preventive (Hb > or = 110 g/L) and treatment (Hb < 110 g/L)
groups. In the preventive group, women entered the study from 20-24 gestational
weeks and were randomly assigned to materna treatment (n = 96) who took materna 1
tablet daily or control group (n = 95) who took no other supplementation. In the
treatment groups, women less than 36 gestational weeks were accepted. They were
randomly divided as materna (n = 93) 1 tablet/d, ferrous sulfate 0.3 g tid/d (n =
50) or Ferroids 1 tablet/d (n = 35) groups. Both Hb and serum ferritin
concentrations were determined at admission and immediately after delivery. In
some cases serum ferritin in the umbilical vein were measured as well. Hemoglobin
levels were examined every 4 weeks during the observational period. RESULTS: In
the preventive groups, maternal serum ferritin levels after materna treatment
were significantly higher than that before treatment and the control group (P <
0.05). As for the anemia women, compared the serum ferritin concentration,
materna treatment had significantly higher levels than that at admission (P <
0.05), and also higher than that in the ferrous sulfate or ferroids tratment
groups (P < 0.05). The s-ferritin in the umbilical vein had no correlation with
the paired maternal levels. There were no significant differences in the
pregnancy outcomes among all the groups. CONCLUSION: Materna can increase the
iron storage and effectively improve the iron deficiency during pregnancy, and
has no impact on the prgnancy outcomes.
PMID- 10682465
TI - [Color Doppler monitoring the utero-placental-fetal circulation variety of normal
pregnancy and intrauterine growth retardation].
AB - OBJECTIVE: To study the utero-placental-fetal circulation (UPFC) in normal
pregnancy and intrauterine growth retardation (IUGR) cases. METHODS: Color
doppler ultrasound was used to detect UPFC in 150 second and third trimester
pregnant women, of which 89 cases were normal pregnancy and 58 cases were IUGR. 3
cases were IUGR with chronic renal failure. Hemodynamical value of the umbilical
artery (UmA), umbilical vein (UmV) and uterine artery (UtA) were examined
directly. The indices included time average velocity (TAV), pulsatility index
(PI), resistance index (RI), systolic/diastolic (S/D) ratio, blood flow volume
(Q). The maternal serum estriol (E3), human placental lactogen (HPL) and plasma
thromboxane B2 (TXB2)/6-keto-PGF1 alpha (6-KP) were measured simultaneously.
RESULTS: The result shows that in normal pregnancy group UPFC is abundant
gradually with increasing gestational age. In IUGR group 92.53% of cases showed
that TAV and Q of UmA, UmV markedly decreased and PI, RI and S/D ratio of UmA
elevated at 20 weeks of gestation. There were significant difference between the
two groups, maternal serum E3, HPL level in IUGR group were significantly lower
than that of the normal pregnancy group, 6-KP level reduced, and TXB2/6-KP ratio
significantly increased. CONCLUSION: Using color doppler ultrasound examining
hemodynamical changes of UmA, UmV and UtA could observe UPFC function directly.
It is one of the best method to early diagnose and predict the prognosis of IUGR.
PMID- 10682466
TI - [Morphometric analysis of gap junctions of the cell membrane in human uterine
smooth muscle at term].
AB - OBJECTIVE: To study the changes of the gap junctions (GJS) in the uterine smooth
muscle cells at various stages of labor, and its relationship with the onset of
labor. METHODS: 18 women (38 to 41 gestational weeks) were divided into three
groups: not-in-labor, pre-labor, active in labor and six cases in each group. The
uterine myometrium tissues were observed by transmission electron microscopy
(TEM) and lanthanum tracing method. RESULTS: The lengths and areas of GJS in
uterine corpus and lower segment in the active in labor group were significantly
larger than that of the other 2 groups, but there was no significant difference
between the not-in-labor and pre-labor groups. The area but not the lengths of
GJS in corpus was significant larger than that in the lower segment in the active
in labor group. CONCLUSION: The great increase of length and areas of GJS in all
parts of the uterine smooth muscle was closely correlated with onset of labor.
PMID- 10682467
TI - [Cervical ripening score by transperineal ultrasonography and its predictive
effect for induction of labor by prostaglandin E2].
AB - OBJECTIVE: To establish a cervical ripening score by transperineal
ultrasonography for induction of labor by Prostaglandin E2, and evaluate its
predictive effect. METHODS: 105 primiparae underwent cervical assessment by
digital and transperineal ultrasonography examination. The five indices of
cervical status, other clinical parameters and latency period (from induction to
the onset of labor) were analysed by Cox multivariate model. RESULTS:
Transperineal ultrasonography was simple, visualable satisfactorily, noninvasive
and less uncomfortable. The width of cervical internal os, the length of the
canal and position of the presenting part were the main factors that influenced
the latency period (P < 0.05). Primiparae with score > or = -4.5 were easy to
initiate the onset of labor within 12 hours (P < 0.001). The predictive results
were in good agreement with clinical outcomes, and had less misdiagnosis (the
Kappa value, specificity and the positive predictive value were 0.7409, 0.7917
and 0.9254, respectively), and were better than the Bishop score (the
corresponding value were 0.5680, 0.6667 and 0.8806, respectively). CONCLUSIONS:
Transperineal ultrasonography is safe and effective. In predicting the effect on
induction of labor of prostaglandin E2 in primiparae, the transperineal
ultrasonographic cervical ripening score is a valuable method.
PMID- 10682468
TI - [Experimental study on the role of insulin-like growth factor-I in ovulation
induction].
AB - OBJECTIVE: To investigate the possibility of insulin-like growth factor-I (IGF-I)
as an adjunctive factor for ovulation induction. METHODS: The model of
anovulatory mice was established by single injection of testosterone propionate.
Thirty anovulatory mice were divided into 3 groups, each contained 10 mice. IGF-I
1 microgram + human menopausal gonadotropin (hMG) 5 IU, IGF-I 2 micrograms or hMG
10 IU alone was injected intraperitoneally to each group respectively. Cyclic
changes of vaginal smear and numbers of oocytes in fallopian tubes were used to
assess the effect. RESULTS: Vaginal smears of 8 mice in IGF-I + hMG group, 6 mice
in hMG group and 2 mice in IGF-I group returned to normal cyclic pattern. The
differences between IGF-I + hMG group and IGF-I or hMG groups were significant (P
< 0.01 and P < 0.05), but the difference between IGF-I group and hMG group was
not significant (P > 0.05). The average numbers of oocytes within fallopian tubes
were 12.3 in IGF-I + hMG group and 9.2 in hMG group (P < 0.05). In IGF-I group
there were no oocytes in the fallopian tubes of two mice whose vaginal smears
returned to normal. CONCLUSION: IGF-I may be a potential agonist agent for
ovulation induction.
PMID- 10682469
TI - [Prevalence of premenstrual syndrome in reproductive women and its influential
factors].
AB - OBJECTIVE: To investigate the prevalence of premenstrual syndrome and its
influential factors in reproductive women. METHOD: A questionnaire was used in
454 reproductive women aged 15-49 in Beijing. RESULTS: The prevalence of
premenstrual syndrome in these women was 30.4%, among which 61.6% was mild, 34.1%
moderate, and 4.3% severe. The order of frequency of the symptoms occurring in
premenstrual syndrome was irritation, depression, anxiety, diarrhea, lack of
concentration and hypersomnia. Women with higher cultural level, greater stress
in life (work or study), dysmenorrhea, dislike menstruation and those with
depression symptom had a higher incidence than those with lower cultural level,
no stress in life, no dysmenorrhea, no dislike toward menstruation and no
depression symptom (P < 0.05). CONCLUSIONS: Premenstrual syndrome is a common
disease in reproductive women. Clinical doctors should pay attention and adopt
comprehensive measures in order to reduce its incidence and improve the quality
of life especially for women with high risk factors.
PMID- 10682470
TI - [The dose-response of cell proliferation and secretion of CA125 II antigen to
follicle stimulating hormone in ovarian cancer cell lines].
AB - OBJECTIVE: To study the dose-response of the proliferation and secretion of CA125
II antigen with follicle stimulating hormone (FSH) in epithelial ovarian cancer
cell lines. METHODS: Two different kinds of ovarian cancer cell lines originated
from different pathologic types-AO and 3AO were studied. Cancer cells were
cultured in medium containing FSH in different concentrations. The proliferation
rate of cells was detected by using the 3H-TdR intrusion technique. The accordant
titer of CA125 II antigen in the culture medium was measured by enzyme linked
immunoadsorbent assay technique. RESULTS: Proliferation rate of cancer cells (AO
and 3AO) was increased apparently as increasing in the concentration of FSH in
the culture medium. A positive correlation was found between them (P < 0.05).
Proliferation rate of AO cells positively correlated with secreting quantity of
CA125 II antigen (P < 0.05), however, no such correlation was found in 3AO cells.
CONCLUSION: It suggested that FSH can stimulate the proliferation of epithelial
ovarian cancer cell at high concentration and there is a accordant dose-response
relationship between them. The secreting pattern of the CA125 II antigen varied
by the pathological classification of the ovarian cancer.
PMID- 10682471
TI - [Effect of mifepristone on the expression of progesterone receptor messenger RNA
and protein in uterine leiomyomata].
AB - OBJECTIVE: To determine the expression of progesterone receptor (PR) mRNA and PR
protein levels in the myometrium and leiomyomata from untreated and mifepristone
pretreated women with leiomyoma and to examine the mechanism of mifepristone
treatment on uterine leiomyomata. METHODS: Expression of PR mRNA and PR protein
were determined by Northern blot and HAP of single-dose saturated analysis in
myometrium and leiomyomata (center and marginal area) from 27 untreated and 6
mifepristone pretreated women with leiomyomata. RESULTS: PR mRNA abundance and PR
protein levels in both myomatous center and marginal area were significantly
greater than those in corporal myometrium (P < 0.01) in both follicular and
luteal phases, but similar between myomatous center and marginal area (P > 0.05).
6 cases pretreated with mifepristone 25 mg/day for 3 months were operated, all
but one patient displayed a decrease in leiomyomata volume. PR mRNA abundance in
both myometruim and leiomyomata (center and marginal area) was significantly
decreased in 4 patients continuing mifepristone treatment before the operation
but not in the other 2 patients stopping RU486 1 month before operation. PR
protein levels in these tissues showed significant decrease in all 6 cases.
CONCLUSION: There are overexpression of PRmRNA and PR protein in leiomyomata. One
of the mechanism of mifepristone action on decreasing leiomyomata volume may be
related to suppression on expression of PR gene. It seems that suppression on
transcription of PR gene is reversible, but on translation of PR gene may
maintain in a relatively longer period.
PMID- 10682472
TI - [The morphometric study of endometrial spiral arterioles before and after
insertion of gamma CuI and TCu 220C intrauterine devices].
AB - OBJECTIVE: To investigate the morphologic changes of endometrial spiral
arterioles and its relationship with bleeding pattern after insertion of gamma
shape copper indomethacin-medicated (gamma CuI) and T-shape copper (TCu 220C)
intrauterine devices (IUD). METHODS: Endometrium specimens of late secretory
phase were obtained from fertile age women: 10 from preinsertion, 10 obtained
after insertion of TCu 220C IUD, and 9 obtained after insertion of gamma CuI IUD.
Samples were sectioned serially and morphometric analysis of endometrial spiral
arterioles was performed under light microscope. RESULTS: The average cross
section area (Area), maximum diameter (Dmax) and minimum diameter (Dmin) of
spiral arterioles in both spongeous and dense layers of endometrium increased
significantly after insertion of TCu 220C IUD. After insertion of gamma CuI IUD,
the Area and Dmax increased in dense layer only, though less obviously than that
occurred in TCu 220C group. However, the Dmin increased more obviously in both
spongeous and dense layers than after insertion of TCu 220C IUD, implying that
the shape of spiral arterioles was more regular in gamma CuI group. CONCLUSION:
gamma CuI IUD has less effects on the morphological changes of endometrial spiral
arterioles, and this may relate to its indomethacin-contained which causes less
bleeding.
PMID- 10682473
TI - [Human immunodeficiency virus infection among gynecology and obstetrics
patients].
PMID- 10682474
TI - [Gestational diabetes and fetal macrosomia].
PMID- 10682475
TI - [Clinical uses of maternal serum markers in the prenatal diagnosis].
PMID- 10682476
TI - [Human cytomegalovirus infection and congenital malformation].
AB - OBJECTIVE: To study the relationship between intrauterine cytomegalovirus (HCMV)
infection and congenital malformation, and to determine the distribution of
tissues infected. METHODS: Autopsy samples of 41 infants with congenital
malformation and 19 infants with normal appearances were studied. Using
polymerase chain reaction (PCR) technique the paraffin embedded specimens of main
organs were examined for HCMV infection. In-situ hybridization (ISH) was
performed in some of the PCR positive tissues in order to define the distribution
of HCMV DNA. RESULTS: 19 of the 41 infants (46.34%) with congenital defects were
HCMV positive, while 1 in 19 (5.26%) were positive in the control group, and
there was significant difference between the 2 groups (P < 0.05), 20.46% (35/171)
of the fetal organ samples were HCMV DNA positive in the malformation group, but
only 1 out of 78 samples (1.28%%) was positive in the pulmonary tissue of the
control group. More malformations of the digestive system were presented in HCMV
infected babies but no statistical significant difference when compared with
other systems. Brain tissue had the highest HCMV infection rates (41.37%, 12/29),
which was significantly higher than other organs. By ISH technique HCMV DNA was
found only in 6 out of 17 PCR positive samples, and they were located at neurons,
neurogliocytes, epithelium and interstitial cells of the kidney, and epithelial
cells of pulmonary alveolar. CONCLUSION: There are strong correlation between
HCMV infection and congenital malformation, and brain is more susceptible to
HCMV. By combining PCR and ISH, both sensitivity and distribution of HCMV could
be obtained.
PMID- 10682477
TI - [Detection of human cytomegalovirus infection in pregnant women and their fetuses
by nested polymerase chain reaction].
AB - OBJECTIVES: To evaluate the applicability of nested polymerase chain reaction
(PCR) and restriction endonucleases analyses (REA) for the diagnosis of human
cytomegalovirus (HCMV) in pregnant women and their fetuses. METHODS: Nested PCR
and REA, virus isolation, anti-HCMV-IgM and anti-HCMV-IgA were used for detection
of HCMV in peripheral blood of pregnant women, umbilical blood and tissues of
stillbirths. RESULTS: Among 367 pregnant women, the HCMV infections rate in the
first, second and third trimester of gestation were 8.6%, 1.6% and 7.0%,
respectively. The nested PCR had significantly higher detective rate (4.9%) than
that of virus isolation (3.0%, P < 0.025). Among 6 samples of maternal HCMV DNA
positive blood, 3 matched umbilical samples were HCMV DNA positive as well. Of
these 3 cases, HCMV intrauterine infection was considered. HCMV was detected with
all measurements in both maternal and umbilical blood except in 1 paired samples
specific-IgM were negative. HCMV DNA was found in the lung tissue of one of the
28 stillbirds. CONCLUSION: The diagnostic specificity and sensitivity of HCMV can
be raised by nested PCR.
PMID- 10682479
TI - [Weight gain pattern in normal pregnant women].
AB - OBJECTIVE: The purpose of this study was to determine the maternal weight gain
pattern of normal pregnant women. METHODS: One thousand five hundred and sixty
two (1,562) women, with 11,059 records, received prenatal care and had their
babies delivered at the Second Hospital of West China University of Medical
Sciences during the period of Jan. 1-Dec. 31, 1995. All the women without
complications and with their babies weighted between 2,500-3,999 g were included,
and data was analyzed. RESULTS: The average age was 26.49 +/- 3.02 and height
158.69 +/- 4.85 cm. The women were divided into three categories according to
their prepregnant body mass index (BMI): underweight (< 16.75), normal weight
(16.75-23.71) and overweight (> 23.71). The BMIs of each categories increased as
gestational week approached to the term, with total BMI increase as 8.07, 5.37,
3.82 for underweight, normal weight and overweight, respectively. CONCLUSION:
BMI, calculated with weight and height, is more accurate to assess maternal
weight gain than weight alone do, and above results and accompanied charts could
be used to monitor maternal weight gain as a reference.
PMID- 10682478
TI - [Prenatal gene diagnosis of alpha-thalassemias].
AB - OBJECTIVE: To study the value of polymerase chain reaction (PCR) in prenatal
diagnosis of alpha thalassemias. METHODS: Amniotic fluid prenatal gene diagnosis
with polymerase chain reaction was carried out on eleven fetuses whose parents
are both heterozygotes with alpha-globin gene deficiency. A DNA fragment of 224bp
in the production means normal alpha-globin gene sequence, while a 630bp fragment
indicated the alpha-globin gene deficiency. Both 224bp and 630bp fragments in the
same sample means heterozygote. RESULTS: Three of the 11 fetuses (one pregnancy
was twin) were with normal alpha-globin gene sequence, while 4 were homozygotes
and the other 4 were heterozygotes. For the 3 fetuses with ascitic fluid under
ultrasound examination, 2 were homozygotes and the other one was heterozygote by
gene diagnosis. Two of the 4 homozygotes from induced abortion were typical
Bart's syndrome, one was edema in the whole body and the other one with short
limbs and abdominal hernia. CONCLUSION: The method of PCR in prenatal diagnoses
for detection of alpha-thalassemias is simple, accurate and rapid.
PMID- 10682480
TI - [The evaluation of umbilical arterial Doppler spectrum fractal characterization
in obstetrics].
AB - OBJECTIVE: To evaluate the clinical value of fetal umbilical arterial Doppler
spectrum fractal. METHODS: 104 cases with 22-41 gestational weeks were included,
and divided into two groups: normal pregnant group, 59 cases; abnormal pregnant
group, 45 cases. Umbilical arterial Doppler spectrum were obtained by color
Doppler ultrasound, then Doppler signal were transformed into computer through
sound-frequency, and fractal were calculated. RESULTS: The fractal was 1.83 +/-
0.03 in normal pregnant group. The frequency of abnormal fractal was
significantly higher in abnormal pregnant group than that in normal pregnant
group (P < 0.001). Compared with the ratio of peak systolic to lowest diastolic
flow velocity (S/D), the fractal was more sensitive than S/D ratio in abnormal
pregnancy (P < 0.05). There were significant correlation between fractal and
gestational weeks (r = 0.266). CONCLUSION: Fractal responses to complexity of
umbilical arterial blood flow, and it is a better parameter than S/D ratio in
monitoring abnormal umbilical arterial blood flow.
PMID- 10682481
TI - [The changes of serum nitric oxide level in patients with intrahepatic
cholestasis of pregnancy].
AB - OBJECTIVE: To study the relationship of serum nitric oxide (NO) level with
pathophysiological changes in intrahepatic cholestasis of pregnancy (ICP).
METHODS: 49 patients with ICP and 26 healthy women in their late pregnancy were
studied. The serum NO levels were determined with Greiss reaction by measuring
oxidation products of NO. RESULTS: The serum NO concentration in patients with
ICP decreased significantly when compared with that of healthy pregnant women.
The serum NO level in patients with ICP was related to the time of persistent
pruritus, the serum concentration of bilirubin and glutamic-pyruvic transaminase
(GPR). There is no correlation between serum NO and cholylglycine. In the ICP
group the average gestational age was shorter than that of normal pregnancy and
the weight of newborn was also lower. CONCLUSIONS: The decline of serum NO may
play an important role in the pathophysiological changes in ICP and may cause the
intrauterine growth retardation, premature delivery and fetal hypoxia.
PMID- 10682482
TI - [Assessment of fetal maturation by epithelial growth factor in serum of pregnant
women].
AB - OBJECTIVE: To study the concentrations of human epithelial growth factor (EGF),
progesterone (P) in serum, and EGF, P, amylase (Ams), creatinine (Cr) and total
bilirubin (TB) in amniotic fluid at different trimester normal pregnancy.
METHODS: The concentrations of EGF, P in serum of 181 cases of pregnant women
(first trimester 35, midtrimester 69, late trimester 77) and the concentrations
of EGF, P, Ams, Cr, TB in amniotic fluid of 87 cases (mid-trimester 44, late
trimester 43) were determined. At the same time, the concentrations of EGF, P in
serum of umbilical veins and arteries from 23 full term neonates were determined
as well. The concentrations of EGF and P were measured by radioimmunoassay and
Ams, Cr, TB in amniotic fluid by PA110 autobiochemistry analyzer. RESULTS: (1)
The concentrations of EGF, P in serum increased as pregnancy advanced. (2) There
were significant correlations between EGF level and Ams, Cr levels in amniotic
fluid. After 32 gestational weeks, the fetal maturity rate was 70.59% when EGF
was > or = 4.5 micrograms/L. There were significant positive correlations between
EGF in maternal serum and in amniotic fluid, (3) The maternal serum EGF
concentration was significantly higher than that in the umbilical vessels, and
there was positive correlations between them. CONCLUSION: The change of maternal
serum concentration could be used to determine the fetal maturation.
PMID- 10682483
TI - [Functional states of pituitary-ovary, adrenal and thyroid axes in women with
polycystic ovarian syndrome].
AB - OBJECTIVE: To assess the role of the functional states of pituitary-ovary,
adrenal and thyroid axes in the pathophysiology of polycystic ovarian syndrome
(PCOS). METHODS: The stimulation tests of above-mentioned three endocrine axes by
luteinizing hormone releasing hormone (LRH, 100 micrograms), adrenocorticotrophin
(ACTH, 250 micrograms) and thyroid releasing hormoune (TRH, 500 micrograms),
respectively, were performed in each subjects of two PCOS groups [luteinizing
hormone/follicle stimulating hormone (LH/FSH) > or = 3, Group 1, n = 15; LH/FSH <
3, Group 2, n = 15] and the control (n = 20). Endocrine indices of corresponding
target glands were evaluated by radioimmunoassay (RIA). RESULTS: After LRH
administration, the amplitude of LH responses in three groups were as follows:
Group 1 > Group 2 > control while mean testosterone levels were elevated to a
similar extent in two PCOS groups and remained unchanged in the control.
Following ACTH stimulation, PCOS subjects, especially of Group 2 with obvious
insulin resistance, showed higher responses of cortisol, dehydroepiandrosterone
sulfate and testosterone as compared with the controls. However, during TRH
testing, exaggerated thyroid-stimulating hormone and prolactin responses in two
PCOS groups and blunted free thyroxine response at two hour point in Group 1 were
observed, as compared with the control. CONCLUSION: It appears that ovarian
androgen excess in women with PCOS is mainly LH-dependent in Group 1 and insulin
dependent in Group 2. Enhanced adrenal activity may contribute to both
hyperandrogenism and insulin resistance in this syndrome, and subclinical
hypothyroidism may exist in affected subjects, especially of Group 1.
PMID- 10682484
TI - [The effect of sex steroids on human ovarian granulosa cell apoptosis].
AB - OBJECTIVES: To study the molecular mechanism of human follicular atresia by
exploring the effects of estrogen, androgen on human granulosa cell (GC)
apoptosis. METHODS: Ovarian GC DNA fragments of both atretic and developing
follicles before and after estrogen (1 microgram/ml), androgen (1 microgram/ml)
treatments were analysed by agarose gel electrophoresis. The expression of bcl-2
mRNA was also determined by northern blotting in GC of developing follicle after
sex steroids addition. RESULTS: Internucleosomal DNA cleavage occurred in
granulosa cells in atretic follicles and after androgen treatment. In granulosa
cells of developing follicles, estrogen treatment increased the expression of bcl
2 mRNA by 45%, while androgen treatment downregulated the expression of bcl-2
mRNA by 35%. CONCLUSION: Androgens increase apoptotic DNA fragmentation, and
decrease the expression of bcl-2 mRNA in GC of developing follicles, while
estrogens produce the opposite effect. Therefore, expression of bcl-2 may be
involved in the mechanism of follicular development and atresia.
PMID- 10682485
TI - [Patterns of cisplatin induced apoptosis in ovarian cancer cell line COC1].
AB - OBJECTIVE: To elucidate the patterns of chemotherapeutic drugs induced apoptosis
and its role in cancer chemotherapy. METHODS: Apoptosis in cultured ovarian
cancer cell line COC1 induced by ciplatin was investigated in vitro by applying
cytohistochemistry stain, florescence stain and electron microscopy scanning
combining with DNA gel electrophoresis and flow cytometry analysis. RESULTS:
After exposure to cisplatin, COC1 cells manifested typical apoptotic
morphological features. Apoptosis persisted throughout 30 hours following
addition of cisplatin and augmentated gradually. The rate of apoptosis was
enhanced within tested dose range in a dose dependent pattern. At the point of 12
hour cisplatin exposure, the necrosis rate was only 12.4% while the apoptotic
rate accounted for 30.8% already. CONCLUSIONS: Chemotherapeutic drugs induced
apoptosis is one of the primary mechanism of anti-cancer chemotherapy.
PMID- 10682486
TI - [The relationship between the pathological classifications and molecular genetics
of hydatidiform moles].
AB - OBJECTIVE: To study the relationship between the pathological classification and
molecular genetics of hydatidiform mole. METHOD: 32 cases of hydatidiform mole
were analyzed by DNA restriction fragment length polymorphism (RFLP, hybridized
with the probe 33.15). RESULTS: DNA from only paternal origin was found in 21,
and from both parents in 11. In the formeron the basis of pathological
characteristics, the complete hydatidiform mole (CHM) and the partial
hydatidiform mole (PHM) were 16 (76%, 16/21) and 5 (24%, 5/21) respectively, and
in the later CHM and PHM were 5 (45%, 5/11) and 6 (55%, 6/11), respectively.
CONCLUSION: There is not much correlation between pathological classification and
molecular genetics of hydatidiform mole.
PMID- 10682487
TI - [Detection and sequence analysis of the p53 gene mutation in epithelial ovarian
cancer].
AB - OBJECTIVE: To find the characteristics of p53 gene mutation in epithelial ovarian
cancer and to analyze the relationship between p53 mutation and FIGO stage.
METHODS: p53 mutations in exon 5 to 7 were detected by single-strand
conformational polymorphism (SSCP) and sequencing technique. RESULTS: 8 of 46
tumor tissues demonstrated a SSCP band shift in the region of the gene. All of
them have been characterized to represent DNA alterations by sequencing,
including 8 point mutations (6 missence, 1 silent mutation and 1 in intron) and a
1-base pair insertion (introducing a stop codon downstream). Overall, 88.9% of
mutation were transitions, and most of them are G-->A transitions (7/8, 87.5%).
62.5% of the mutation were found in 175 and 245 codon. The percentage of the
mutation in stage I and stage II was 20.0%, and in stage III and stage IV was
16.7% (P > 0.05). CONCLUSION: The arising of p53 mutations in ovarian cancer is
due to spontaneous error in DNA synthesis and repair. Codon 175, 245 are the two
mutational hot spots. There is no relationship between the mutation of p53 gene
and FIGO stage in epithelial ovarian cancer.
PMID- 10682488
TI - [Investigation of intrauterine microbes after intrauterine operation].
AB - OBJECTIVE: To explore the postoperative changes in the cultures of ureaplasma
urealyticum (UU), mycoplasma hominis (Mh), L-form bacteria (L-form), anaerobic
bacteria (Ana) and chlamydia trochomatis (CT) after intrauterine operation.
METHODS: Four groups of patients were set up: group 1, induced abortion; group 2,
intrauterine device (IUD) insertion; group 3, penicillin i.m. after IUD
insertion; group 4, oral lincomycin after IUD insertion. Intrauterine secretion
were aspirated to identify the above microbes before operation and within 1 week
of ending of menstrual bleeding for 4 consecutive postoperative cycles. Bacteria
carrier was defined as at least one of the 5 microbes detected. RESULTS: No
difference was shown in the incidence of bacteria-carrier (IBC) among the 4
groups preoperation. The IBC tended to be the highest in the first menstrual
cycle postsurgery in all the 4 groups, then decreased. Compared with
preoperation, there were significantly higher IBC in the 3 IUD groups (P < 0.05)
except group 1. CONCLUSION: IUD is a major factor for intrauterine microbes
existing after operation, and the natural body defense system can help to get rid
of the organism by time. Small doses and short period of penicillin or lincomycin
administration proved not effective in clearing the intrauterine microbes after
IUD insertion.
PMID- 10682489
TI - [Predicative factors of long-term occurrence of diabetes in the patients with
gestational diabetes].
PMID- 10682490
TI - [New concepts of pathology in serious borderline tumor in ovarian neoplasm].
PMID- 10682491
TI - [Ovarian malignant tumor metastatic to the breast].
PMID- 10682492
TI - [A team of modern epidemiologists are needed in China].
PMID- 10682493
TI - [Epidemiologic study and prevention and control of communicable diseases in army
in China: experiences and successes].
PMID- 10682494
TI - [Zeng-Ding phenomenon: further demonstration and studies on its predictive value
in epidemic of measles and scarlet fever].
AB - OBJECTIVE: To demonstrate further the existence of Zeng-Ding phenomenon in
disease epidemic and to explore the relationship between it and the time series
in different kinds of diseases. METHODS: Incidence data of notifiable
communicable diseases during 1975 to 1996 were collected. Time series of measles
and scarlet fever incidence during 1975 to 1995, 1980 to 1995, 1985 to 1995 and
1990 to 1995 were established. Correlation analysis was conducted between monthly
cumulative percentage and predictive ratio of increase to decrease in incidence
rate at the best cut-off point. Prediction was studied based on the constructed
extrapolation model. RESULTS: Correlation analysis showed that 98.3% (232/236) of
the coefficients of correlation were negative (R < 0), indicating further the
existence of Zeng-Ding phenomenon in disease epidemic. There was significant
difference in coefficients of correlation between the four time series, which
accounted for 63.8%, 54.2%, 44.1% and 35.0%, respectively; and for 73.3%, 56.7%,
36.7% and 36.7%, respectively, in measles, and for 53.6%, 51.8%, 51.7% and 33.3%,
respectively, in scarlet fever. It showed that Zeng-Ding phenomenon correlated
with the time series and the kinds of diseases. Prediction from extrapolation
model showed that there was significant difference in predictive agreement
between two time series of 1975 to 1995 (65.5%) and 1985 to 1995 (37.0%) with chi
2 of 4.54 and P < 0.05, indicating a trend that predictive agreement increased
with prolonging of time series, and a trend that predictive agreement for scarlet
fever increased with decreasing of coefficients of correlation. CONCLUSION:
Predictive value of the incidence data can be evaluated by their source and
length of time series.
PMID- 10682495
TI - [Detection of S-gene mutation strain in vertical transmission of HBV and its
significance].
AB - OBJECTIVE: To study S-gene mutation of hepatitis B virus (HBV) in its vertical
transmission and its significance. METHODS: Nucleotides of S-gene NT451-660 of
HBV were sequenced with dideoxy end termination technique in four female and six
male carriers without HBV markers in their spouses and in their intrauterine
infected fetuses. RESULTS: It was showed that homology of HBV nucleotide and
amino acid sequences in the mothers, fathers and their fetuses was very high.
Mutation at the sites 491, 494, 530, 546 and 581 of S-gene resulted in amino acid
substitution at the sites 113, 114, 126, 131 and 143, respectively. Mutations at
the sites 126 were detected in two pairs of mother or father and her or his
fetuses and mutations at the sites 131 in four fetuses, respectively, including
combined mutation at the site 143 in two fetuses. CONCLUSION: Strains with S-gene
mutation, mainly at the sites 126, 131 and 143, could be found in HBV vertical
transmissions, which could cause failure in HB vaccine immunization.
PMID- 10682496
TI - [Case-control studies on risk factors for pulmonary tuberculosis in servicemen of
China].
AB - OBJECTIVE: To study the risk factors for pulmonary tuberculosis (PTB) in the
servicemen of armed forces and lay a basis for its prevention and control.
METHODS: A 1:2 matched case-control study was carried cut in the servicemen, with
86 cases and 153 controls. Data were analyzed with conditional logistic
regression with EGRET software. Odds ratios (ORs) were calculated for the
relevant factors. RESULTS: Single-variable analysis showed that schooling,
history of exposure to PTB, history of Bacille Calmette-Guerin (BCG) vaccination
and BCG vaccination scar all associated with the incidence of PTB, with ORs of
2.19, 2.03, 0.38 and 0.54, respectively, and P < 0.05. Multiple logistic
regression analysis showed that BCG vaccination scar, history of exposure to PTB
and schooling all entered the final regression model, with ORs of 0.36, 1.94 and
2.33, respectively. CONCLUSION: It suggested that BCG vaccination could play a
role in the prevention of TB in the servicemen, and history of exposure to PTB
was a potential risk factor for TB as well.
PMID- 10682497
TI - [Seroepidemiological study on Helicobactor pylori infection in rural adult
residents].
AB - OBJECTIVE: To study the prevalence of Helicobactor pylori (Hp) infection in rural
adult residents of China and its relation to serum levels of pepsinogen I (PG I),
pepsinogen II (PG II) and gastrin (GAS). METHODS: Serum levels of antibodies
against Hp were determined with enzyme-liked immunosorbent assay (ELISA) in 1,504
residents aged over 30 in Zanhuang County of Hebei Province, and their serum
levels of PG I, PG II and GAS, as well as PG I/PG II ratio, were analyzed
quantitatively, with radioimmunoassay (RIA). RESULTS: Positivity for serum Hp
antibody accounted for 66.4% of the rural adults in Zanhuang County, without
significant sex difference. There was no significant difference in positivity for
serum Hp antibody between residents in the high and low prevalent areas of
gastric cancer. Serum levels of PG I, PG II and GAS were significantly higher in
those with positive serum IgG anti-Hp (62.3 micrograms/L, 15.45 micrograms/L and
74.00 pg/ml, respectively) than those negative (42.1 micrograms/L, 6.40
micrograms/L and 66.00 pg/ml, respectively), all with a P-value less than 0.005,
and the ratio of serum PG I to PG II levels was significantly lower in the former
(4.0) than that in the latter (6.6), with P < 0.005. CONCLUSION: More than two
thirds of the adult residents in Zanhuang County had infected with Hp, which
could affect their serum levels of PG and GAS.
PMID- 10682498
TI - [Prevalence of HCV and HBV infection in patients with primary hepatocellular
carcinoma in Shanxi Province].
AB - OBJECTIVE: To study the prevalence of hepatitis C and B viruses (HCV and HBV)
infection in the patients with primary hepatocellular carcinoma (PHC) in Shanxi
Province and evaluate their etiologic roles in the pathogenecity of PHC to lay a
foundation for the prevention and control of it. METHODS: Ninety-eight patients
with PHC and 196 non-PHC controls matched in age and sex were selected from the
four hospitals at provincial level in Shanxi Province. Serum antibodies against
HCV (anti-HCV), HBs (anti-HBs), HBe (anti-HBe) and HBc (anti-HBc), IgM-antibody
against HBc (anti-HBc-IgM), HBsAg and HBeAg were determined for all of them with
enzyme-linked immunosorbent assay (ELISA). RESULTS: Positivity for anti-HCV and
rate of HBV infection were 8.16% and 63.37%, respectively, in the PHC patients,
both significantly higher than those in the controls (P < 0.05), with
attributable risk proportions of (ARP) 94%, and 91%, respectively. Multiple
conditional logistic regression analysis showed that positive serum anti-HCV,
HBsAg and anti-HBc a risk factors for PHC, all entered the regression model, with
odds ratios (ORs) of 55.06, 10.18 and 9.85, respectively. Dichotomized
contingency table analysis showed that OR for those positive both for anti-HCV
and HBsAg was 61.37, significantly higher than that for single positive of either
one, with an additive effect. CONCLUSION: It suggested that both HCV and HBV
infection were main etiologic factors for PHC in local. HBV also was an important
factor in the pathogenecity of PHC, especially in those with both positive for
HBsAg and anti-HBc. Coinfection with HBV and HCV had an additive effect on PHC
pathogenecity.
PMID- 10682499
TI - [Demonstration for periodicity of leptospirosis in Yichang City of Hubei Province
during 1960-1997].
AB - OBJECTIVE: To study the periodicity of leptospirosis incidence. METHODS: Data of
leptospirosis epidemics in Yichang City collected during the past 38 years from
1960 to 1997 were analyzed with periodic graphics method. RESULTS: Cause-specific
incidence rate of leptospirosis was 15.43 per 100,000 in average, with an
epidemic interval of 10 years, with statistical significance in periodic
vibration (J = 4.179, P < 0.05). CONCLUSION: The results mentioned above provided
scientific basis for the effective control and prevention of the disease.
PMID- 10682500
TI - [Surveillance of hemorrhagic fever with renal syndrome and studies on its
predictive indices in Jiangsu Province].
AB - OBJECTIVE: To study its predictive significance of the direct use of surveillance
data of hemorrhagic fever with renal syndrome (HFRS) collected in Jiangsu
province, and find an indicator of choice for qualitative prediction. METHODS: A
correlation analysis between the HFRS incidence rate and surveillance data
collected in the past 12 years since 1986 was applied. RESULTS: There was
significant relationship between HFRS incidence rate and indoor density of rattus
norvegicus (Rn), proportions of mixed species of rats and Rn with HFRS virus,
indices of mixed species of rats and Rn with virus in the spring Relationship
between HFRS incidence rate and densities of outdoor mixed species of rats and
Apodemus agrarius (Aa), and proportions of mixed species and Aa with virus was
all significant in autumn and winter. And, there was significant relationship
between HFRS incidence rate during the whole year and annual average density of
rats, proportion of rats with virus, index of rats with virus. There was no
significant relationship between HFRS incidence rate and human inapparent
infection rate. The coefficients of correlation between HFRS incidence rate in
the spring and indices of indoor mixed species of rats and Rn with virus were
0.8637 and 0.8295, respectively (P < 0.001). And, those between HFRS incidence
rate and indices of outdoor mixed species of rats and Aa were 0.7089 and 0. 7258
in the autumn and winter, respectively (P < 0.01). The coefficients of
correlation between HFRS incidence rate in the next spring and indices of outdoor
mixed species and Aa with virus in the autumn were 0.7118 and 0.7113,
respectively (P < 0.01). The coefficient of correlation between HFRS incidence
rate during the whole year and annual average index of rats with virus was 0.9207
(P < 0.001). CONCLUSION: The index of rats with virus was an indicator of choice
for qualitative prediction of HFRS, and the density of rats may be the secondary
choice.
PMID- 10682501
TI - [Cost-benefit analysis for hepatitis A vaccine].
AB - OBJECTIVE: To improve economic benefits of hepatitis A (HA) vaccination and to
lay a foundation for formulating an immunization strategy for it. METHODS: Health
economics methods were used for analyzing the cost-benefit ratio, balance point
of cost-benefit and balance point of antibody level after HA vaccination.
RESULTS: The benefit-cost ratio (BCR) for HA vaccine was 2.53 in Jiangxing City
of Zhejiang Province with an HA-specific incidence rate of 41.15 per ten
thousand. Incidence rate of HA was 16.26 per ten thousand at balance point of
cost-benefit of HA vaccine. Cost would be reduced if serum HA antibody was
screened before vaccination in the population with more than 50% of seropositive
HA antibody. CONCLUSION: It indicated that more economic benefits would be gained
if mass HA vaccination strategy was used. Vaccinee of choice was those at ages of
15 to 29 years. HA vaccination after antibody screening in the population aged
over 25 years would be more economic than the direct use.
PMID- 10682502
TI - [A case report of heterosexual transmission of HIV infection between spouses with
persistent condom use].
AB - OBJECTIVE: To report a case of heterosexual transmission of HIV infection between
spouses with consistent condom use. METHODS: The first case with HIV infection
was detected in the contracted male workers returned from abroad in Qingdao in
1992 and both he and his spouse were given health education for AIDS/HIV
prevention and instructions on condom use. And, his wife was followed-up every
six months by detecting her serum anti-HIV. RESULTS: The wife of the index case
was negative for anti-HIV in the first 12 blood tests before December 1996. But,
she was found suspect of positive for anti-HIV an July 1997 and definitely
positive for anti-HIV-1 in August 1997 during her 14th test. In the period of
1992 to 1997, they persisted in condom use during intercourse. Recall of the wife
showed that she had low fever in May 1997, suggesting at the window phase of her
acute HIV infection. It postulated that she infected with HIV curing March to
April 1997. CONCLUSION: The case report indicated that incorrect use of condom
could not prevent from HIV transmission between spouses.
PMID- 10682503
TI - [Quality evaluation of locally-prepared kits for HIV antibody detection in
clinical applications].
AB - OBJECTIVE: To evaluate the quality of eight kinds of locally prepared enzyme
linked immunosorbent assay (ELISA) kits for HIV antibody (anti-HIV) detection and
study their current status in clinical applications. METHODS: Two hundred serum
specimens were tested with eight kinds of locally prepared ELISA kits for anti
HIV screening, with an imported kit as reference, including 100 specimens with
confirmed positive, negative or undetermined anti-HIV and 100 specimens collected
from the drug abusers in Xinjiang Region. RESULTS: Anti-HIV could be detected in
all the 74 confirmed positive specimens with the imported reference kit, with
sensitivity of 100%. But, six to eighteen specimens were false negative detected
with local prepared kits, with sensitivities of 81.1%-91.9%, mainly in those
collected from the drug abusers with weak positive for anti-HIV. Two of the 107
confirmed negative specimens were false positive by the imported reference kit,
with a specificity of 98.2%, and 0-8 specimens were false positive by locally
prepared kits, with specificities of 92.5%-100%. CONCLUSION: The sensitivity of
locally prepared ELISA kits for anti-HIV screening should be improved further to
ensure the safety of blood transfusion and the control of AIDS/HIV.
PMID- 10682504
TI - [Experiences and achievements in the control of schistosomiasis in China].
PMID- 10682505
TI - [Experiences in the basic control of sexually transmitted diseases and their
recurrences in China].
PMID- 10682506
TI - [Review on the study of Keshan disease in China].
PMID- 10682507
TI - [Risk factors for initiation of drug use among young males in Longchuan, Yunnan].
AB - OBJECTIVE: To identify the risk factors for drug use among young males in
Longchuan, Yunnan. METHODS: A non-concurrent cohort study was carried out based
on a cross-sectional survey. Demographic, behavioral, and drug-using related
information were collected using an anonymous questionnaire. The non-concurrent
cohort included the period January 1, 1991 to August 1, 1994. Risk factors were
assessed by univariate and multivariate analysis. RESULTS: The annual incidence
of drug use increased between 1991 and 1993. Multivariate analysis identified the
following risk factors for drug use: being born to Jingpo ethnic group (OR = 1.8,
95% C.I. 1.2-2.5), being divorced/ widowed/separated (OR = 8.9, 95% C.I. 1.8
43.3), smoking cigarettes (OR = 2.4,95% C.I. 1,6-3.8), having had pre-/extra
marital sex (OR = 1.5, 95% C.I. 1.1-2.2), having been encouraged by friends to
try drugs (OR = 8.8, 95% C.I. 6.1-12.9) and having a family member who used drugs
in 1991 (OR = 1.5, 95% C.I. 1.0-2.3). More than six years of education was a
protective factor for drug use (OR = 0.6, 95% C.I. 0.4-0.98). The population
attributable fractions were 70.8% for being encouraged by friends or others to
try drugs, 50% for smoking cigarettes and 24% for being Jingpo ethnic group.
CONCLUSION: Results suggested that community based programs to change attitudes
towards smoking cigarettes and drug use could dramatically reduce the incidence
of new drug users in Longchuan County. We, therefore, recommend a community-based
intervention program targeting adolescent.
PMID- 10682508
TI - [Logistic regression analysis of female drug abusers' social-psychological
factors].
AB - OBJECTIVE: To study the social-psychological health status on female drug
abusers. METHODS: Case-control study and logistic regression analysis. RESULTS:
Results of simple logistic regression showed that factors with significant ORs
were low education level, unemployment, marital status, senseless of life, self
killing, horror, madness, depression, insomnia, dizziness, perspiration, evil
dream, divorce, setbacks of emotion, smoking, alcohol-abuse, playing truant,
runaway from home, fighting, etc. The results of stepwise logistic regression
analysis showed that factors entered the regression model were smoking, runaway
from home, divorce, setbacks of emotion, marital status, hopeless toward life,
level of education, dizziness, etc. CONCLUSION: Most female drug abusers' social
psychological status was poorer than controls preceding to their drug abuse,
which contributed to the major causes of abuse drugs.
PMID- 10682509
TI - [Analysis on the epidemic characterization and trend of AIDS in Fujian Province].
AB - OBJECTIVE: To analysed the epidemic characterization and trend of AIDS in Fujian
Province based on data obtained from HIV sero-survallance, HIV-1 subtyping and
epidemiological survey. METHODS: Serum samples collected from people in high risk
groups and specific subgroups were examined for antibody against human
immunodeficiency virus (HIV). Epidemiological investigation was conducted toward
people who were sero-positive. Clinical data on patients with AIDS were also
collected. Peripheral blood mononuclear cells (PBMCs) obtained from HIV-1
infectious and patients with AIDS were used for DNA amplification between C2-V3
region by PCR. The amplified products were sequenced to identify HIV-1 subtypes.
RESULTS: From January 1987 through the end of December 1997, a total number of
569,873 serum samples from high risk groups and specific subgroups including
blood donors and people that travelling abroad frequently were examined for HIV
antibody Seventy people with HIV-1 sero-positive were identified, accounting for
0.12/1000 of the total detected numbers. Among them, 21 patients with AIDS in
which 18 cases had died. HIV/AIDS cases were mainly distributed along the coastal
cities as Fuzhou, Quanzhou and Xiamen where economic development was growing
rapidly. Most cases were infected abroad and spreading HIV to the country through
sexual transmission. Clinical data showed that early syndromes and reversal fever
of patients with AIDS were seen but survival time was short. Nucleotide
sequencing showed that HIV-1 strains in the province were most subtype E.
CONCLUSION: HIV epidemic in the province will mainly be spreading among people
with sexually promiscuous behaviors.
PMID- 10682510
TI - [A prevalence study on injuries among 2,553 children 7-16 years old].
AB - OBJECTIVE: In order to find out the present situation and cause of injuries among
children. METHODS: A cluster sampling study on the conditions of injuries was
conducted among 2,553 children 7-16 years old during the period of October 1996
to September 1997 in Shantou City, Guangdong Province. RESULTS: There was a trend
that the incidence of injuries increased with age among children. The overall
incidence of injuries was 37.96% with schoolboys higher than schoolgirls (P <
0.05). There were 38.1% children who had more than two episodes. Falls took the
leading type of incidence among both sexes and all age groups. Among the causes
of injuries, playing, motion, riding and walking ranked the consecutive leading 4
places. The places where injuries occurred were mainly at home and then on
campus. Self injured was mostly seen followed with hurt by others (classmate,
sibling, et al). Medium and serious injuries took up 8% with a disability rate of
121.4/100,000. CONCLUSION: Some preventive measures were preliminarily suggested.
PMID- 10682511
TI - [Progress of speeding up measles control strategies in Anhui].
AB - OBJECTIVE: To speed up measles control program. METHODS: Catching-up immunization
campaigns on measles have been conducted among the children aged 1-6 years in
three prefectures of Anhui by the end of 1997 and the measles surveillance system
was established at the beginning of 1998. IgM antibody of measles and rubella was
tested with ELISA and IgG antibody was examined with HI test. RESULTS: The
positive rate of measles antibody among children was 100%, GMT increased from
1:18.97 to 1:43.45 after the campaigns. Measles cases in the three districts from
January to June 1998 had a 87.71% decrease, comparing with the same period of
1997 with measles outbreak avoided. There were 105(58.01%) cases of measles with
positive IgM and 32(17.68%) cases of rubella with positive IgM out of 181 testees
having fever and rash illnesses. CONCLUSION: Results indicated the programs as
catching-up immunization campaigns on measles and keeping high level of MV
immunization, establishing measles surveillance system with improvement of its
sensibility together with rubella control program all seemed to be important
strategies in speeding up the positive outcome of measles control.
PMID- 10682512
TI - [Evaluation on the establishment and operation on neonatal tetanus surveillance
program in Hainan Province].
AB - OBJECTIVE: In order to learn the actual morbidity and influencing factors of
neonatal tetanus(NNT) and to provide scientific basis for NNT elimination.
METHODS: A surveillance program was set up in 1997 in Hainan Province and to
operate at the same time. RESULTS: 216 NNT cases were investigated in 1997. The
number was higher than reported 78 cases. The result from surveillance showed
that parturition at home and the old delivering method were the main influencing
factors 88.89% of mothers of NNT cases had no TT immunization history. The
surveillance data of Sanya City and Qiongzhong County indicated the NNT morbidity
in 1997 had declined 61.29%, 82.05% than that in 1996 respectively due to the
improvement of TT immunization rate. CONCLUSION: The study result proved that the
most economical and effective measure to eliminate NNT is to increase TT
immunization rate of women at child-bearing-age. It was practical integrate the
NNT surveillance program into AFP surveillance system and operate along with it.
PMID- 10682513
TI - [A large-scale study on the safety and epidemiological efficacy of Japanese
encephalitis (JE) live vaccine (SA14-14-2) in the JE endemic areas].
AB - OBJECTIVE: To measure the safety and epidemiological efficacy of Japanese
encephalitis live vaccine(SA14-14-2). METHODS: Guoyang and Mengcheng counties in
Anhui Province, were chosen as observed spots where high incidence of JE was
noticed in China. 1-6 years old children in two counties were inoculated with
vaccine manufactured by Chengdu Biological Products Institute in the beginning of
1992. All children of 1-6 years old received one primary dose of live vaccine and
the children at one or two years old were respectively given one dose for primary
or booster vaccination in 1993-1996. Side effects of live vaccine had been under
surveillance for five years for its safety JE cases during the epidemic season
(Jun to October), were diagnosed clinically and serologically. RESULTS: Data on
the safety and efficacy of the JE live vaccine(SA14-14-2) are listed as
follows:1) During 1992-1996, a total number, of 335,941 children at 1-6 year old
were vaccinated. No vaccine-associated encephalitis, meningitis or other serious
adverse events were observed. 2) The incidence of JE case has greatly declined
since the beginning of large-scale vaccination. The average JE morbidity dcreased
from 11.34/100,000 in 1987-1991 to 2.74/100,000 in 1992-1996(P < 0.005). 3) The
incidence of JE case in 1-6 years old in that period reduced as well. The average
JE morbidity decreased from 56.24/100,000 to 13.83/100,000 in Guoyang and from
44.57/100,000 to 16.94/100,000 in Mengcheng counties respectively(P < 0.005).
Most of the JE cases (94%) occurred in the unvaccinated children including all
the 18 death cases. 4) Serum antibody response to immunization were measured by
plaque reduction neutralization test. Neutralizing antibody seroconversion after
one single vaccination were 83.87%-94.74%. CONCLUSION: The results further
confirmed that JE live vaccine is safe for children and effective for prevention
from JE disease in JE endemic areas.
PMID- 10682514
TI - [The investigation of natural antibody level to Haemophilus influenzae type b
polysaccharide in China].
AB - OBJECTIVE: Investigation of natural antibody level to Haemophilus influenzae type
b polysaccharide in China. METHODS: 1,596 sera samples from cord (55 sera),
infants (1,383 sera), children (66 sera), adult (52 sera) and elderly (40 sera)
were collected from different provinces and the natural antibody level to PRP was
measured with a standardized radio immunoassay 125I-labeled PRP. RESULTS:
Antibody level of infants under 5 year olds in different provinces was different.
Levels of infants from Gansu, Guizhou, Jiangxi province were lower (< or = 0.07
microgram/ml) than from Shanhai, Guangxi and Heilognjiang. Comparison of antibody
levels with different age groups showed that infants aged 6 months to 5 years
having the lowest antibody level (< 0.15 microgram/ml). The level increased
rapidly during 6-10 years of age (> or = 1.0 microgram/ml). The levels of adults
and elderly were about 1-1.5 micrograms/ml. CONCLUSION: General immunity against
Hib disease were low in Chinese population. Children aged 6 months to 5 years old
with lowest natural antibody level to PRP were the population under high risk.
PMID- 10682515
TI - [Analysis on characteristics and risk factors of acute myocardial infarction in
younger adults].
AB - OBJECTIVE: To investigate the risk factors and characteristics related to acute
myocardial infarction (AMI) in younger adults. METHODS: Clinical data were
analyzed in 55 patients under 40 years old with AMI and compared with 1,097
controls of older age group (> or = 40 years). RESULTS: Results showed that the
family history of coronary heart disease, smoking and alcohol intake were more
frequently seen in younger age group than those in control group with odds ratios
OR = 1.4, OR = 1.6 and OR = 1.6, respectively. Younger age group had a higher
rate of noticeable inducing cause and the major causes were exhaustion and
physically over-hurdened. A higher percentage of typical chest pain was found in
younger patients. CONCLUSION: Smoking, alcohol drinking and genetic factor made
up major risk factors of coronary heart disease in younger adults in this study,
however reducing the amount of smoking and alcohol drinking, prevention of
fatigue and over excitement might have some preventive impact on the prevalence
of AMI in younger population.
PMID- 10682516
TI - [Cellular immunity and epidemiologic analysis of pediatric patients with
Mycoplasma pneumonia].
AB - OBJECTIVE: To understand the of immuno-reactions of pediatrics patients with
Mycoplasma pneumonia. METHODS: 90 patients suffered from M. pneumonia were
administered and divided into three groups: mild group, severe group, and normal
control group. T cell subset parameters, natural killer cell and the serumsoluble
interleukin-2 recepter of all of above were determined. RESULTS: Data showed:CD4
decreased at both acute and recovery stage of M. pneumonia, while CD8 remarkably
increased (t = 2.63, 66, 2.77, 3.36, P < 0.05). SIL-2R level of all patients also
greatly increased (t = 5.26, 3.19, P < 0.01), especially in the serious group.
CONCLUSION: There are disturbances of cell-immune in M. pneumonia. The level of
SIL-2R can serve as monitor on the degree of severeness of M. pneumonia. The
incidence M. pneumonia appeared highest in the 10-14 year-old group.
PMID- 10682517
TI - [Measurement of serum tumor necrosis factor-alpha and interleukin-8 in children
with low respiratory tract infection (LRTI) caused by Mycoplasma pneumonia].
AB - OBJECTIVE: To investigate the immunopathological mechanism of LRTI caused by
Mycoplasma pneumonia. METHODS: Serum tumor necrosis factor-alpha (TNF-alpha) and
interleukin-8 (IL-8) from 30 patients with LRTI caused by Mycoplasma pneumonia,
were measured with sequence saturated solution competitive radioimmunoassay and
sandwich ELISA. RESULTS: The level of serum TNF-alpha and IL-8 of patients
suffering from LRTI caused by Mycoplasma pneumonia were magnificantly higher than
that of healthy children. Meanwhile, a positive relationship between serum TNF
alpha and IL-8 was noticed. CONCLUSION: TNF-alpha plays an important role in LRTI
caused by Mycoplasma pneumonia, and serves the key factor to the elevation of IL
8.
PMID- 10682518
TI - [Argument over meta-analysis in medicine].
PMID- 10682519
TI - [Epidemiologic study and prevention of AIDS in China].
PMID- 10682520
TI - [Progress on the study of prevention and control of anthrax in China].
PMID- 10682521
TI - [Marked success of prevention and control of sex transmitted diseases in pastoral
area of Inner Mongolia Autonomous Region in China: epidemiologic survey and
serologic follow-up study of syphilis].
PMID- 10682522
TI - [Study of superinfection of HBV and HCV].
AB - OBJECTIVES: To understand the situation in hepatitis B patients coinciding with
HCV and to explore its influence on HCV on the replication of HBV. METHODS: Using
ELISA, 712 hepatitis B patients were tested for serum anti-HCV and markers of
HBV. RESULTS: Of the 712 patients, anti-HCV positive rate was 14.47% with the
highest 48.98% in patients with severe hepatitis and the lowest 3.25% in patients
with acute hepatitis. Markedly different anti-HCV positive rates (P < 0.001) in
patients of different clinical stages were discovered. The more severe the case
with longer the course, the higher the anti-HCV positive rates. In patients with
superinfection of HBV and HCV, serum HBsAg, HBeAg and anti-HBcIgM positive rates
were lower than those in patients with hepatitis B (P < 0.001, P < 0.001 and P <
0.05) but the anti-HBe positive rates were higher. All the differences showed an
obvious statistical significance. CONCLUSION: Hepatitis B coinciding with HCV
infection is responsible for the deterioration of the disease and towards its
formation of its chronic phase as well as for the inhibition of HBV replication.
PMID- 10682523
TI - [Analysis on the mis-reported cases of infectious diseases in Hainan Province].
AB - OBJECTIVE: To investigate the reasons for mis-reporting cases and to furnish
theoretical foundation for the control of infectious diseases. METHOD: 15
hospitals and 2,937 residents were selected and studied through random and
systematic sampling methods in Hainan Province. RESULTS: Data showed that the mis
reporting rate in clinics was 44.40%, among which the private-ran clinics had a
highest mis-reported records. They not only failed to fill in the forms of
reporting infectious diseases, but also neglected to report epidemic information.
Malaria, hepatitis, syphilis and gonorrhea were among the highest mis-reported
diseases with malaria the most (91.73% mis-reporting rate). Remarkable difference
was noticed in various hospitals (P < 0.01). CONCLUSION: The author concluded
that many infectious diseases were seriously mis-reported, indicating the
reporting system should be improved and the quality be enhanced.
PMID- 10682524
TI - [Epidemiological analysis of the fires happened in China from 1950 to 1994].
AB - OBJECTIVE: Approaching the harmful factors and the preventive steps of fires for
controlling and preventing fires from harming people. METHOD: Descriptive
analysis was used to review 2,905,504 fires-cases in China from 1950 to 1994.
RESULTS: On average, there were 3,432 people died and 6,726 injured in 64,567
fires per year. From the middle of 70's, the means of injured and death rates
decreased slightly, but have gone up a little after 80's. The economical loss has
risen greatly year after year, reaching the maximum of 1.3 billion Yuan (RMB) in
1994. The loss of a fire case in 1994 was more than twice than that in 1990.
89.4% fires were caused by man's faults. The fire cases in Sichuan, Yunnan,
Jiangshu, Zhejiang and Guangdong Provinces were more serious than the average, of
which Guangdong was the worst. Data from 17 departments showed that, the fire
frequency in residential quarters of cities and countryside were highest (24%),
and the number of injury and death accounted for 28.4%. The fire happens
frequently in winter, and least in summer. CONCLUSIONS: The problem caused by
accounted fire has not been controlled effectively.
PMID- 10682525
TI - [A study of genetic epidemiology on child bronchial asthma].
AB - OBJECTIVE: To examine the relationship between child bronchial asthma and genetic
fastor. METHODS: A case-control study including 372 pedigree was carried out.
RESULTS: Child bronchial asthma had obvious familiar clustering (chi 2 = 24.8, P
< 0.01). The prevalence rate of the first and the second degree relatives of
proband was significally higher than that of the controls. The segregation ration
of asthma was 0.14 (95% CL 0.098-0.18). The h2 of the first and second degree
relatives of asthma were 78.18% and 55.02%, of which 83.64% for female and 73.48%
for male. CONCLUSION: The genetic model of asthma belonged to polygenetics.
Genetic fastor was a main risk fastor for asthma, especially for female patients.
PMID- 10682526
TI - [Prevalence study of congenital heart disease in children aged 0-2 in Zhejiang
Province].
AB - OBJECTIVE: To find out the prevalence rate of Congenital Heart Disease (CHD)
among infants and toddlers. METHODS: Heart auscultation and echocardiography
examination on children aged 0-2 were examined in 13 cities (or counties) in
Zhejing province. RESULTS: Findings showed that the prevalence rate in children
aged 0-2 was 3.72/1000. The prevalence rates of CHD were quite different among
age groups with the highest (5.54/1000) in age group 0, followed by 3.36/1000 in
age group 1 and lowest (2.66/1000) in age group 2. No significant difference of
prevalence rates was found between different sex. Ventricular septal defects
(59.4%) was noticed as the most common lesion. CONCLUSION: The evidence indicated
that CHD is one of the most important problems of public health in China.
Preventing its occurrence by conducting CHD surveillance and its etiologic
research will have great significance for enhancing the qualities of life of
children.
PMID- 10682527
TI - [Investigation on the prevalence and influencing factors to anemia in women at
reproductive age].
AB - OBJECTIVE: To investigate the prevalence of anemia in women of reproductive age
and to analyze the influencing factors in anemia. METHODS: A total number of
1,529 women aged 15-49 years old including workers, farmers, cadres and students
were tested with Hb and FEP and investigated through questionnaire including
related influencing factors. Statistical analysis was performed using SPSS/PC
statistical software. RESULTS: Mean value of Hb was 116.35 g/L (SD 14.67 g/L) in
1,529 cases and the prevalence rate of anemia was 31.2%. Majority of the anemia
identified belonged to the 'iron deficiency type'. Influencing factors on anemia
included occupation, education, marriage status, menstruation, status of family
expenses and physical exercise. CONCLUSION: The prevalence rate of anemia in
reproductive aged women was high, thus more attention should be paid. In order to
lower the incidence of anemia, preventive and intervenient measurements should be
conducted accordingly.
PMID- 10682528
TI - [Markov process method in analyzing longitudinal quality of life data].
AB - OBJECTIVE: To present a method to analyze longitudinal quality of life data and
discuss some relevant questions. METHOD: Based on the theories of Markov process,
the Markov method was presented and used to analyze the change of quality of life
status for 212 cases being detoxificated drug addicts and their influence
factors. RESULTS: The intensity coefficients of status transient for 1-->2 and 2-
>3 for occupation were 0.7912 and 0.6797 respectively; the coefficients for
status 1-->2 for the detoxification time was 0.5663 and that for 2-->3 for the
detoxification method was 0.2765. CONCLUSIONS: The Markov method is good to
analyze longitudinal quality of life data for it can analyze both the transient
probabilities between any two status of quality of life and their influence
factors. The results showed that the occupation of drug addicts, the
detoxification time and method can affect the change of quality of life.
PMID- 10682529
TI - [Study on the association and significance between trace elements and rectal
cancer].
PMID- 10682530
TI - [Analysis on epidemiological feature of injuries in civic students of Jiangmen].
AB - OBJECTIVE: In order to set up intervention measures in preventing injuries.
METHODS: An analysis on the epidemiological feature of injuries in 9 civic middle
and primary schools with 3,988 students involved was carried out in July 1998.
RESULTS: The results showed that the total rate of 12 kinds of injuries was
50.55%. Among which, 5 kinds of injuries took the first 5 places: injuries from
falls (32.15%), knife-cutting or sharp weapon hurt (21.99%) bumps (17.05%)
traffic accidents (12.51%) burns and scalds (11.43%). CONCLUSION: The rate of
injury was related closely with age parent's culture background and the number of
children in families, but was not significantly related to sex, parent's
occupation and the condition of living with relatives. Strengthening supervision,
safety health education and increase awareness on self-protection were the most
important points. Some intervention measures were being put into practice.
PMID- 10682531
TI - [Long-term efficacy study of hepatitis B vaccination in newborns--results of 11
years' follow-up].
AB - OBJECTIVE: To evaluate the long-term efficacy of hepatitis B(HB) vaccination in
newborns and the need for a booster dose. This research is one of the longest HB
vaccine follow-up studies in the world with its subjects came from a program of
universal infant HB vaccination. METHODS: Children who were born in 1986 and
immunized with hepatitis B vaccine at birth were followed up at least once a
year. Serum HBsAg, anti-HBc and anti-HBs were tested. At the 5th year after the
first dose the prevalence of hepatitis B infection in the children in other
district who were also born in 1986 and remained unvaccinated was surveyed as
external controls. Random sampling was applied and the possible bias was
analyzed. The trends of the positive rates of serum HBsAg, anti-HBs and anti-HBc
in the immunized cohort were studied. With external control, the long-term
efficacy of HB vaccination was calculated. RESULTS: The positive rates of HBsAg
in the vaccine group from the first to eleventh year were 0.46%-0.98% and were
below than those of baseline and external control. HBsAg rates in the cohort at
different ages were similar with an average of 0.70%(25/3 578). The long-term
efficacy of newborn vaccination was 85.42% (95% confidant interval: 70.11%-100%).
CONCLUSIONS: The efficacy of HB vaccine was long-lasting and a booster dose was
not necessary at least up to age 11 years.
PMID- 10682532
TI - [Gene therapy of AIDS].
PMID- 10682533
TI - [Epidemiologic study of risk factors of gallstone].
PMID- 10682534
TI - [Global eradication of small-pox: historical fact, experiences and
enlightenment].
PMID- 10682535
TI - [Progress in the study of spotted fever in China].
PMID- 10682536
TI - [Molecular-epidemiological analysis of HIV-1 initial prevalence in Guangxi,
China].
AB - OBJECTIVE: In April 1996, HIV-1 infection was first found among both commercial
blood donors and IDUs in Guangxi. In order to identify the source of HIV-1
transmission and analyze the trend of HIV-1 epidemic, the study was carried out.
METHODS: HIV-1 genetic subtypes were determined by peptide enzyme immunoassays
(PEIA), RT-PCR and DNA sequencing. RESULTS: Four subtypes of Group M HIV-1 were
found in Guangxi:subtype B' (Thai B), C,D and E. Subtype E and C (1 person) were
circulating among IDUs and hetrosexual, while subtype B' and D (1 person) were
among commercial blood donors. Subtype B' infections were discovered among a
group of commercial blood donors and one of them was infected by subtype D.
CONCLUSION: It is the first report of subtype D infection and subtype E that were
identified in China. This observation indicated that subtype E HIV-1 was spread
into China from Southeast Asia, and a new epidemic region with subtype E HIV-1
would emerge in southern China. Serotyping might be a useful screening method for
HIV-1 molecular epidemiological analysis.
PMID- 10682537
TI - [Investigation on the effect and strategy of polio eradication in Hainan
Province].
AB - OBJECTIVE: Hainan Province was a hyperendemic area of poliomyelitis, with an
average incidence rate of 0.28 per hundred thousand before 1993. A series of
strategy was developed for polio eradication in the whole province in July 1993.
METHODS: Health education, regular and strenthening immunization programs, AFP
surveillance. RESULTS: 1. OPV vaccination rate increased to 97.93%, 2. incidence
rate of polio had a 80.93% reduction, 3. seasonal peak of epidemic was cut down,
4. endemic cycle was broken and 5. the endemic area became smaller. The number of
counties (cities) where polio cases occured reduced for 81.33% in 1993 than that
in 1989. Four boosters had been implemented from 1993 to 1997, to eliminated
blank spots of immunization. The average geometric antibody of titre increased to
1:400 and above. After the establishment of polio surveillance system in 1991, 1.
the reporting rate of non-AFP increased from 0 to 1.27 per hundred thousand, 2.
rate of double specimens collection increased from 0 to 87.10%, 3. positive rate
of virus isolation from 23.07% to 34.80%, 4. the positive specimens were
appraised by National Polio Surveillance Center and no wild strain was found.
Health education has made remarkable impact and immunization knowledge among
parents had a 75 percentage point increase. CONCLUSION: Results showed that
strategy of polio eradication has made positive effects and provided valuable
experiences for the control or elimination of diseases which can be prevented by
vaccines.
PMID- 10682538
TI - [An effective measure to prevent and control STDs through epidemiological
surveillance on sex-related criminals].
AB - OBJECTIVE: To study the prevalence and trend of sexually transmitted diseases
(STDs) among sex-related criminals and to strengthen the strategy on prevention
and control of STDs. METHODS: STDs surveillance on 956 criminals at selected
sites in Beijing had been consecutively monitored during the period of 1996-1997.
Data was then collected and analyzed. RESULTS: Out of the 956 criminals, 317
(33.2%) cases were identified as having STDs. Among them NGU took the first place
and followed by gonerrhea and syphilis. CONCLUSION: The results revealed that
STDs had become one of the major infectious diseases in Beijing and its incidence
increased annually. Epidemiological surveillance on sex-related criminals is one
of the effective measure in reducing the sources of infectious.
PMID- 10682539
TI - [Study on hepatitis G virus infection].
AB - OBJECTIVE: To find out the situation of HGV infection in Shandong Province, and
to explore the relations between HGV infection and HCV or HBV infection. METHODS:
Enzyme linked immunosorbent assay (ELISA) was used to determine the serum anti
HGV in 1,082 patients with viral hepatitis, 77 patients with non A-E hepatitis
and 361 blood donors. RESULTS: 53 patients whose serum anti-HGVs were positive
(positive rate: 3.49%) were noticed. The anti-HGV positive rate (8.93%) in
patients with Hepatitis C was remarkably higher than that (3.32%) in patients
with Hepatitis B (chi 2 = 8.80, P < 0.01). The anti-HGV positive rate (4.82%) in
patients with chronic hepatitis was significantly higher than that (0.79%) in
patients with acute hepatitis (chi 2 = 10.79, P < 0.01). The anti-HGV positive
rate (8.00%) in patients with severe hepatitis was obviously higher than that in
patients with acute hepatitis (chi 2 = 10.23, P < 0.01). CONCLUSION: The
manifestations of HGV infection can be expressed as virus-carriers, subclinical
infection or various clinical types. Patients with Hepatitis C were more
subjective to be overlapped with HGV than the patients with Hepatitis B;
moreover, HCV or HBV infection superinfected with HGV is associated with
exacerbation of patients' condition and the formation of chronic infection.
PMID- 10682540
TI - [Study on seroprevalence of Helicobacter pylori infection among upper digestive
tract cancer patients and their kindreds].
AB - OBJECTIVE: In order to analyse the association between Hp infection and the risk
of upper-digestive tract cancer. METHODS: In Huaian and Pizhou cities, Jiangsu
province, Hp IgG quantitative-enzyme-immunoassay methods was used to identify IgG
to H.pylori in the serum of 312 cases of upper-digestive tract cancer patients
and their kindreds. RESULTS: (1) The level of IgG to H. pylori and the IgG
positive rate (50.0%) in gastric cancer patients were both higher than that of
cardia and esophageal cancer patients (P > 0.05, chi 2 test) but no significant
differences were observed between cardia and esophageal cancer patients, 3 types
of cancer patients and their kindreds; (2) the overall positive rates of both
patients and kindreds in gastric cancer families (27.1%) were significantly
higher than that of cardia or esophageal cancer families (P < 0.05) but no
significant differences were observed between cardia and esophageal groups.
CONCLUSION: H.pylori infection was not thought to be correlated with the
development of gastric cancer, although higher clustering of Hp infection in
families afflicted with gastric cancer was noticed.
PMID- 10682541
TI - [Matched case-control study for detecting risk factors of breast cancer in women
living in Chengdu].
AB - OBJECTIVE: To detect the risk factors of breast cancer in women living in Chengdu
in order to identify high risk population and to conduct proper interventions.
METHODS: A matched case-control study was performed in 265 cases with breast
cancer who lived in this area. RESULTS: In the univariate analysis, menarche to
menopause period > or = 35 years, taking oral contraceptives, history of benign
breast diseases, passive smoking, and syrup drinking are the statistically
significant risk factors of breast cancer, whereas breast feeding and soybean
food consumption are protective factors. Conditional logistic multivariate
analysis revealed that history of benign breast diseases and passive smoking are
risk factors while soybean food products and breast feeding are protective
factors. CONCLUSION: The risk factors of breast cancer in women living in Chengdu
are history of benign breast diseases and passive smoking.
PMID- 10682542
TI - [A case-control study on the dietary risk factors of upper digestive tract
cancer].
AB - OBJECTIVE: To understand the effect of dietary factors in Yangzhong, Jiangsu
Province-a high prevalence area in China. METHODS: A case-control study on 209
cases of upper digestive tract cancer was conducted. There were 68 cases of
esophageal cancer, 69 cases of cardiac cancer and 72 cases of other gastric
cancers including 129 males and 80 females aged 35-79 under the study. RESULTS:
It is revealed that intake of pickled vegetables increases the ORs of esophageal,
cardiac and other gastric cancers (OR = 2.82, OR = 5.17, OR = 2.92,
respectively). It is also concluded that the intake of leftovers can elevate the
ORs of esophageal and cardiac gastric cancer (OR = 1.88 and OR = 1.90) and over
consumption of salt also elevates the OR of cardiac cancer (OR = 1.87). However,
drinking green tea may decrease the ORs of esophageal and other gastric cancers
(OR = 0.20 and OR = 0.28) while fruits consumption may reduce the OR of
esophageal cancers (OR = 0.51). CONCLUSION: Tumors from upper digestive tract
have some relations with diet factors but the effects vary with the differences
of tumor sites, dose of exposure and area, etc.
PMID- 10682543
TI - [An investigation on the prevalence of diabetes mellitus among 336 health
workers].
AB - OBJECTIVE: To find out prevalence of diabetes millitus among health workers.
METHODS: Physical examination was conducted among 336 health workers. Blood
glucose was determined by routine glucokinase method. RESULTS: Results showed
that IGT was 26.49%. According to the WHO diagnostic standard, the prevalence
rate of diabetes was 9.23% (31/336) with type II 96.77% and type I 3.22%. Among
diabetes cases, 61.29% (19/31) was newly diagnosed. The prevalence rates of IGT
and diabetes were related to age and both BMI (Trend chi 2 test: P < 0.01) and
family history were important factors (OR = 10) 42.11% of the new cases had
complications. CONCLUSION: It is important to provide health workers with more
knowledge on the prevention of diabetes.
PMID- 10682544
TI - [A case-control study on the risk factors in naevus fusco-caeruleus zygomaticus].
AB - OBJECTIVE: To determine the risk factors of naevus fusco-caeruleus zygomaticus, a
case-control study was conducted in 100 cases. METHODS: The selection of major
risk factors was through logistic regression and chi 2-test. RESULTS: It was
suggested that the high exposed rate in the family history of objectives was
related to "genetic susceptibility". Histories of using cosmetics and exposure to
ultraviolet ray were identified as environmental risk factors. However, there was
no single factor that could completely explain the etiology of naevus fusco
caeruleus zygomaticus. CONCLUSION: We believe that coordinating effects of both
susceptibility in genetics and environmental risk factors may play important
roles in the pathogenesis of naevus fusco-caeruleus zygomaticus. Thus combined
research on the location of gene mutation with environmental factors is important
in the discovery of the etiology of naevus fusco-caeruleus zygomaticus.
PMID- 10682545
TI - [The epidemiological study on limb deformities among children in Guangdong
Province].
AB - OBJECTIVE: To study the incidence of limb deformities of children in Guangdong
province. METHODS: Physical examination on lined-up students and looked over one
by one. Detailed examinations of orthopaedics or related subjects were performed
on those with susceptive deformity. RESULTS: Results showed that there were 655
cases of limb deformities (0.64%) in 102,313 pupils of 7 to 14 years old, in
which 550 cases (83.97%) needed surgical intervention. The incidence of deformity
in economically poor areas was 2.88 times higher than those in advanced areas.
CONCLUSION: Prevention and cure of limb deformities of children, especially those
in rural area, should be addressed and emphasized.
PMID- 10682546
TI - [A serological investigation of Legionella infection in six-species of poultries
and domestic animals in Luzhou City, Sichuan Province].
AB - OBJECTIVE: To understand the prevalence rates of Legionella infection in poutries
and domestic animals in Luzhou city. METHODS: Serological investigation of
antibodies against Legionella pneumophila serogroups 1-14 and Legionella micdadei
was carried out, using microagglutination test (MAT) in six species of poutries
and domestic animals. RESULTS: Results showed that the infection with multiple
serogroups was present. However, each species had its own serogroup with positive
rates of different serogroups ranging from 2.00% to 28.75%. Positive rates of
domestic animals and poultry accounted for 4.49% and 6.47% respectively.
CONCLUSION: It was suggested that poultries and domestic animals were widely
infected with Legionella. It is important to carry out epidemiological
surveillance in these domestic animals, poultries and environment for a better
control program of this disease.
PMID- 10682547
TI - [Evaluation on the quality of life among cardiac carcinoma cases--fifteen years
after surgical treatment].
AB - OBJECTIVE: To investigate factors affecting the quality of life among long-term
survivors after resection of cardiac carcinoma. METHODS: Follow-up study on the
quality of life among 68 cases with carcinoma of the cardia who survived over 15
years postoperatively in our hospital, was conducted between January 1996 and
June 1998. RESULTS: Results showed that 88.2% of the patients had a high sense of
well-being, 86.8% of them were able to eat ordinary food, 64.7% of them could
carry on regular work as well as physical labor. 89.7% of the patients were
satisfied with their quality of life and 77.9% of them felt excellent.
CONCLUSION: The postoperative mental status and the occurrence of long-term
complications in digestive tract played an important roles in affecting the
quality of life.
PMID- 10682548
TI - [The use of risk factors scoring method in screening for undiagnosed diabetes in
general population].
AB - OBJECTIVE: Based on an epidemiological survey of NIDDM in the general population,
two sub-population groups were selected to develop a screening method on risk
factors to identify people at increased risk for undiagnosed diabetes. METHODS:
Logistic regression analysis on the original data of population A was carried out
to screen the main risk factors of diabetes. The score of the variable was
determined based on the OR value and the aggregate score was used to predict the
risk of undiagnosed diabetes. Both validity and effectiveness of the method were
evaluated in population B. RESULTS: Results showed that the risk of having
diabetes in the population increased along with aggregate scores of the method.
Trend chi 2 test showed statistical significance (P < 0.01). When the threshold
value was set up at 7, both sensitivity and specificity for identifying
undiagnosed diabetes were 74.3% and 63.2%, respectively making the positive
predictive value 4.2% and negative predictive value 99.2%. CONCLUSION: The
benefits of this screen method seemed to be simple, economical and helpful to
obtain a satisfactory response rate. The method could be used for health
education and to identify people (community) at high risk for potential diabetes.
It was predicted that this screening method could serve as an effective and
useful tool for mass screening of NIDDM.
PMID- 10682549
TI - [Study on double antigens sandwich enzyme immunoassay for detection of Brucella
specific antibodies in human and animals].
AB - OBJECTIVE: In order to develop practicable methods for serodiagnosis,
surveillance and epidemiological surveys in human and animals Brucellosis.
METHODS: A double antigens sandwich Enzyme Immunoassay (DAgS-EIA include DAgS
ELISA and DAgS-DIEA) have been developed under the basis of first production
conjugate of Brucella antigen with horseradish peroxidase. Serum samples from
diagnosed patients, suspected patients of Brucellosis and sheep infected with
Brucella in Henan and Hebei provinces as well as from experimental animals of
infected with Brucella in laboratory detected through DAgS-EIA, I-ELISA, RBPT and
SAT tests. RESULTS: Of the diagnosed and suspected Brucellosis patients, positive
rates of DAgS-ELISA, RBPT, I-ELISA, DAgS-DIEA and SAT were 60.0%-62.9%, 48.6%
58.1%, 55.6%, 53.7% and 44.2% respectively; as for sheep with Brucella-infection,
positive rate of the above mentioned 5 tests were 81.8%. CONCLUSION: Results
showed that DAgS-EIA were not only specific and practicable but may use for
Brucella specific antibodies detection in humans and various animals with only
one conjugate of Brucella antigen with horseradish peroxidase.
PMID- 10682550
TI - [Schistosoma japonicum ferritin: cloning, nucleotide sequencing, expression, and
purification].
AB - Our previous work showed that immunization of mice with Schistosoma japonicum
(Sj) immature eggs induced significant immunity against fecundity and
embryonation of the parasite. The Sj adult cDNA library was screened by sera from
rabbits against Sj immature egg antigen (RASjIEA). The genes encoding molecules
which may induce immunity against fecundity/embryonation were chosen for further
cloning and expression. First of all, RASjIEA was absorbed with E. coli lysate to
remove cross reactive antibodies. The cDNA library was then immunoscreened using
the routine method. The resulted positive plaques were rescreened till individual
clones were confirmed. Phagemids were obtained using in vivo excision. The
positive clones were amplified using PCR. The sizes of the genes were determined
by agarose gel electrophoresis. After DNA sequencing of the genes cloned, Gene
bank was searched and six different genes were identified from a total of 102
positive clones. One of six identified genes, Sj ferritin (SjFer) was chosen to
subclone into pGMC vector. According to DNA sequences of Sj Fer and MCS (multiple
cloning site) of the vector, forward primer (Fer/GMC1) and reverse primer
(Fer/GMC2) were designed and used to amplify Sj Fer by PCR. The Sj Fer cDNA and
expression vector pGMC were digested with BamHI and XhoI. The digested cDNA and
pGMC were ligased by T4 DNA ligase to construct a recombinant which was then used
to transform E. coli strain ER2566. The fusion protein GMCSF-Sj Ferritin was
expressed in insoluble form, the inclusion body. Pellets were harvested and
resolved in Tris-HCl buffer containing 8M urea. GMCSF-Sj Ferritin was purified by
affinity chromatography using Ni-NTA resin. The molecular weight was determined
by SDS-PAGE. This study first reports the gene encoding S. japonicum ferritin as
a new candidate for schistosome vaccine.
PMID- 10682551
TI - [Alterations of amino acids in rat cerebral cortex of infectious brain injuries].
AB - Concentrations of amino acids such as glutamate(Glu), glutamine(Gln), gamma
aminobutyric (GABA), glycerin(Gly) in rat cerebral cortex were measured by o
phthaldialdehyde method to clarify alterations of these amino acids in infectious
brain injuries(IBI). The results were that Gln and GABA in groups treated by
bordetella pertussis suspension(BP) 4h were increased compared to those in the
group treated by the normal saline(NS) or the operative control(OC) and a
positive correlation with water content or Evans blue content, respectively. In
the 24h BP group, Gln was still increased; GABA and Gly were decreased compared
to those in the NS or OC group. The findings suggest that GLu, Gln, and Gly play
an important role and GABA may be a marker of injury in pathogenetic mechanism of
IBI induced by BP.
PMID- 10682552
TI - [Influence of ischemic preconditioning of heart on ischemia/reperfusion injury of
rabbit lung].
AB - The influence of ischemic preconditioning of heart on ischemia-reperfusion injury
of 16 Japanese big-ear-rabbit lungs were studied. The results showed: 1.
Experimental group had a significant reduction in wet/dry weight ratio; 2. It had
a significant increase in PaO2. 3. It had a minimal intraalveolar neutrophil
infiltration in comparison with the control group. These data suggestes that the
ischemic preconditioning of heart can lighten the ischemia-reperfusion injury of
rabbit lungs.
PMID- 10682553
TI - [Experimental study of FZBZ decoction enhancing chemotherapy efficacy for mice
bearing with tumors].
AB - To study the mechanism of the increasing effect of Fuzheng Baozhen decoction
(FZBZD) on chemotherapy. The BALB/C mice with transplanted human lung
adenocarcinoma (SPC-A-1), sarcoma (S180) were treated in different groups.
Comparing the group treated with chemotherapy (CTX), and the group treated with
CTX plus FZBZD, the inhibiting tumor rate was higher (P < 0.01), the cAMP/cGMP
ratio was increased by adding cAMP level in cancer tissue (P < 0.05), the level
of serum TNF-alpha and MDA was decreased (P < 0.01), the activity of total SOD
was improved (P < 0.01), the G0/G1 phase cells enhanced and S phase cells
decreased in tumor tissue (P < 0.05). It suggested that FZBZD increased the
effect of chemotherapy in different ways.
PMID- 10682554
TI - [Oxidative DNA damage of cartilage in osteoarthrosis].
AB - In order to study molecular mechanism of osteoarthrosis, we used molecular
techniques to detect DNA oxidative damage of cartilage. There were 10 samples
from clinical operation including 5 cases of replacement of hip joint, 4
degenerative cartilage of knee osteoarthrosis, and 1 free body of knee joint. DNA
from all samples was run out on an agarose gel and appeared classic nucleosomal
ladders. (8-hydroxyl-2'-deoxyguanosine)/ml (8-OHdG) in DNA samples was measured
by high-performance liquid chromatography with electrochemical detection (HPLC
EC). The results showed that the levels of 8-OHdG were increased to 0.11-0.26
ng.ml-1, average 0.177 ng.ml-1. Normal controls were lower than 0.05 ng.ml-1. The
high 8-OHdG in DNA led to a misreading of affected templates and base-pair
exchange, which could be a sensitive indicator about oxidative DNA damage, which
was produced by free radicals or other DNA damage agents. The result suggests
that oxidative DNA damage may be the molecular mechanism of osteoarthrosis.
PMID- 10682555
TI - [Relationship between expression of tumor suppressor protein p21 and p53 and cell
proliferation in the gastric carcinoma].
AB - To study the relationship between the expressions of tumor supressor protein p21
and p53 and malignant growth of gastric carcinoma, 88 paraffin embedded specimens
of gastric carcinoma and gastric ulcer were examined with immunohistochemical
method. We found that the expression rate of mutated protein p53 in the gastric
carcinoma was about 40% and the expression rate of p21 protein in gastric mucous
carcinoma, undifferentiated carcinoma, poorly differentiated carcinoma was
obviously low. The expression of PCNA in gastric adenoid cancer was very high.
The results suggest that the low expression of p21 proteins and mutation of p53
proteins in gastric cancer cells play a certain role in the morbidity of gastric
carcinoma, but its involvement in the malignant growth of gastric carcinoma cells
is not obvious.
PMID- 10682556
TI - [The prevalence of Chlamydia trachomatis and Ureaplasma urealyticum cervical
infection in infertility women and the observation of therapeutic efficacy].
AB - OBJECTIVE: To study the prevalence of Chlamydia trachomatis (CT) and Ureaplasma
urealyticum (Uu) cervical infection in infertility women, and therapeutic
effectiveness of tetracycline and qianglimycin. METHOD: CT in cervical swab
specimen was detected by cell culture, polymerase chain reaction(PCR) and
immunofluorescent assay(IFA), Uu in cervical swab specimen was detected by
culture, in a group of 145 infertility women, before and after treatment, and 45
women at productive age who attended obstetric and gynecologic clinic. RESULT:
The positive rate of CT by cell culture, PCR, IFA(shell) and IFA(direct smear)
was 62.7%, 66.8%, 64.8% and 36.5%, respectively, which was obviously higher than
that of the control (P < 0.01). The positive rate of Uu was 33.1%, that of CT and
Uu co-infection was 18.6%. Both were obviously higher than those of the control
(P < 0.01). CONCLUSION: This study indicates that the prevalence of CT and Uu
cervical infection in infertility women is high. CT and Uu cervical infection is
closely related to female infertility. The therapeutic effectiveness of
tetracycline and qianglimycin is not ideal.
PMID- 10682557
TI - [Influence of dietary habits and body weight on blood uric acid in the elderly].
AB - Influence of dietary habits, body weight on blood uric acid was studied in 416
elderly people. The result showed that level of blood uric acid in the people who
had habits of drinking alcohol, tea and taking hot foods was higher than that who
never had those habits (P < 0.05 or 0.01). It also showed that level of blood
uric acid was significantly increased in the over-weight or obesity people (P <
0.05). The hyperuricemia incidence in the over-weight or obesity people is 27.4
per cent, and it is 2 times and 3.4 times of the people with ideal weight and
weak-weight, respectively. It is suggested that the patients with gout or
hyperuricemia give up drinking alcohol, tea and taking hot foods for their
health. Reducing body weight is one of the effective measures to prevent and
treat gout or hyperuricemia in the elderly.
PMID- 10682558
TI - [Efficacy of epimedium compound pills in the treatment of the aged patients with
kidney deficiency syndrome of ischemic cardio-cerebral vascular diseases].
AB - One hundred-twenty aged patients with kidney deficiency syndrome of ischemic
cardio-cerebral vascular diseases were treated with Epimedium compound granules.
The results showed that after therapeutic period the total and marked effective
rates were 96.7%, 39.5% respectively in treatment group. The rates of improvement
were 70% in electrocardiogram of the patients with coronary heart diseases, and
75% in electro-encephalogram of the patients with cerebral arterosclerosis. The
therapeutic effectiveness in treatment group was better than that in control
group treated with Su-Guan-Bian. According to experimental observation, the
therapeutic effectiveness was related to the facts that Epimedium compound
granules lower blood lipid have anti-free radicals and adjust balance between
prostacyctin I2 and thromboxane A2(TXA2/PGI2).
PMID- 10682559
TI - [A prospective study on etiologic bacteria in 200 patients with pneumonia].
AB - The etiologic agents in 200 patients with pneumonia were studied by the bacterial
culture of sputums obtained from the protected single catheter brush or
quantitative expectoration at one morning or three-morning expectoration. Two
hundred patients were divided into 3 groups. Group 1 was Nosocomial pneumonia (NP
patients). Group 2-1 and Group 2-2 were community acquired pneumonia (CAP
patients). All cases in Group 1 and Group 2-2 suffered from significant
underlying diseases while Group 2-1 did not. Gram-negative bacilli(GNB) were
isolated from the specimens in Group 1 (87%) and Group 2-2 (75%), respectively.
Pseudomonas (30.8%) and klebsiella (20.5%) were the predominant bacteria (in
Group 1 and pseudomonas bacteria) in Group 1 and pseudomonas (27.3%),
acinetobacter (23%) and kledsiella (18%) were the major etiologic agents in Group
2-2. The commonest pathogens in Group 2-1 were gram-positive cocci (75%), in
which streptococcus (38%) and staphylococcus aureus (25%) were the dominant
agents. Compared with Group 2, Group 1 suffered from more mixed bacteria and the
agents presented severer drug-resistant. The prognosis was worse in Group 2-2
than in Group 2-1. The results showed that the GNB pneumonia was more common in
the cases who had underlying disease, no matter whether the pneumonia was NP or
CAP. These patients had more trouble on their antibiotic therapy. Thus it is
important that doctors should use vigorous antibiotics timely while treating
these patients' underying diseases.
PMID- 10682560
TI - [Relationship between ventricular arrhythmia and blood lipid in hypertensive
patients with left ventricular hypertrophy].
AB - The possible relationship among ventricular arrhythmia(VA), blood lipid(BL) and
left ventricular hypertrophy(LVH) were investigated in 92 patients with essential
hypertension(EH). The results showed that the incidence of VA and complex VA and
ventricular tachycardia(VT) were significantly higher in EH with LVH than those
in EH with non-LVH. The incidence of VA and complex VA and VT were highest in
hypertensive patients with LVH accompanied with hyperlipemia(HL), and VA seemed
closely related to left heart structure and BL. The results suggest that LVH and
HL are the two additive risk factors of occurrence of VA in patients with EH.
PMID- 10682562
TI - [Clinical study on the orthodontic treatment of deep overbite with bite plane].
AB - Fifteen cases of patients with incisal Angel's Class II obserbite were
orthodontically treated with bite plane and analysed with cephalometric
radiograph. The results showed that bite plane can correct deep overbite rapidly
(within 6 months) and effectively. The mechanism of bite plane was to raise the
posterior teeth (1.1 mm) and to lower the anterior teeth (0.8 mm).
PMID- 10682561
TI - [Relationship between sex hormone levels and blood lipids/immunity in
perimenopausal women].
AB - To investigate the relationship between sex hormone levels and blood
lipids/immunity and to evaluate the therapeutical effects of nylestriol, 96 women
without coronary heart disease(CHD) were studied during their perimenopausal
period. The estimation of serum biochemical components included serum 17 beta
estradiol(E2), testosterone(T), total cholesterol(TC), triglyceride (TC), high
density lipoprotein cholesterol(HDL-C), low density protein cholesterol(LDL-C),
apolipoprotein A-I(ApoAI), apolipoprotein B(ApoB), lipoprotein (a)[Lp(a)],
immunoglobulin G(IgG), and IgG antibody against cardiolipin(ACAIgG). Thirty-six
postmenopausal volunteers were divided into two groups and randomized to treat
with either 2 mg nylestriol or placebo. In postmenopausal women, serum levels of
E2, E2/T, HDL, and ApoAI decreased, while those of T, TC, TG, LDL, ApoB, Lp(a),
IgG, and ACAIgG increased. Serum level of E2 was positively correlated to HDL-C
and negatively correlated to TC, ApoB, LDL, IgG, and ACAIgG. Serum level of T was
positively correlated to LDL, IgG, and ACAIgG and negatively correlated to HDL.
In the nylestriol group, as compared with the results before treatment, serum
levels of TG, TC, LDL, IgG, and ACAIgG decreased and that of HDL-C increased
after treatment. We conclude that estradiol is a protective factor of CHD,
whereas testerone is a dangerous factor. After menopause, the imbalance of the
estradiol/testosterone ratio increases the incidence of CHD. Nylestriol is an
effective substitute for estradiol to prevent CHD in post menopausal women.
PMID- 10682563
TI - [Changes of plasma endothelin-1 in patients with congestive heart failure and the
influence of metoprolol].
AB - To investigate the alterations of plasma endothelin-1(ET-1) in patients with
congestive heart failure(CHF) and the effects of metoprolol on it, plasma ET-1
and norepinephrine(NE) were measured in 43 patients using radioimmunoassay and
high-performance liquid chromatography methods. Twenty-four patients were treated
with metoprolol plus the routine therapy while the others were received the
routine therapy only. The findings were that levels of plasma ET-1 and NE
increased before the treatment, and decreased after the treatment with metoprolol
for 1 month. There was no alteration of plasma ET-1 or NE in the control group.
PMID- 10682564
TI - [Chronic pulmonary heart diseases treated by fraxiparin].
AB - OBJECTIVE: The effects of fraxiparine with hypodermic on the treatment of
patients with chronic pulmonary heart diseases(CPHD) at acute phase were studied.
METHODS: Twenty patients were hypodermically injected with 0.4 ml fraxiparine per
day for 7 days as a course. Fibrin fibrinogen degradation products (FDP and D
dimer), antithrombin III (AT-III), PaO2 and PaCO2 were detected before and after
the treatment. RESULTS: In the therapy group, FDP and D-dimer decreased after the
treatment, AT-III increased. All indexes didn't alter in the control group.
CONCLUSION: Fraxiparine is effective on patients with CPHD at acute phase.
PMID- 10682565
TI - [Clinical significance of heart rate variability: analysis of silent myocardial
ischemia].
AB - To study the potential role of dynamic electrocardiogram(DEG) in silent
myocardial ischemia (SMI) patients, we measured the extension of ischemia and
heart rate variation-time-domain analysis in 148 patients with SMI and 30 healthy
controls by DEG and followed up all patients for 1.5 years. The results were that
the extension of myocardial ischemia (the extension of ST segment depression,
episodes of SMI attack, and the total ischemia time), the incidence rate of
ventricular premature heat increased gradually and the difference of heart rate.
Heart rate variant hinder(HRVI), and SDNN decreased gradually in SMI I, III, II
types. And the extension of ischemia had positive correlation with the lowest
heart rate and the incidence rate of ventricular premature beat, while negative
correlation with HRVI and SDNN, indicating that the impairment of cardial
autonomic nerves is associated with the extension of ischemia. Also, we found
that 23 patients out of 148 patients with SMI died and the levels of HRVI and
SDNN of the patients who died were lower than that of the survivals. We conclude
that the heart rate variability can serve as a prognosis index of SMI.
PMID- 10682566
TI - [Clinical study of fructose 1,6-diphosphate on myocardial ischemia/reperfusion
injuries].
AB - Twenty ventricular septal defect patients who underwent cardiopulmonary bypass
(CPB) were divided into 1,6-diphosphate group and controlled group (10 cases
each). Blood samples were taken at pre- and post-cardiopulmonary bypass 30 min, 6
h, and 24 h to determine lactate dehydrogenase enzyme(LDH), creatine kinase
enzyme(CK) and its isoenzyme(CK-MB) levels. We found that 1,6-diphosphate
decreased the increasing levels of LDH, CK, and CK-MB after cardiopulmonary
bypass. It is suggested that 1,6-diphosphate may attenuate myocardial
ischemia/reperfusion injuries during cardiopulmonary bypass.
PMID- 10682567
TI - [Influence of MP infection on immunologic function in patients with chronic
obstructive pulmonary disease].
AB - The aim of this study was to detect Mycoplasma pneumoniae(MP) in sputum with
chronic obstructive pulmonary disease(COPD) by using polymerase chain reaction
and measured the level of sIL-2R in chronic pulmonary heart disease(CPHD)
patients by Enzyme Linked Immnosorbert Assay(ELISA). At the same time, we also
measured the level of the serum total IgE in CPHD patients. We determine the
relationship between the sIL-2R and lymphocytes. The results showed that rate of
MP infection in COPD patients was 34.59%. The rate of MP infection in CPHD
patients and asthmatic patients were significantly higher than that in patients
with chronic bronchitis. The level of sIL-2R in patients with CPHD who had MP
infection increased significantly higher than that in CPHD patients which didn't
have MP infection. There was a linear negative correlation between the level of
sIL-2R and lymphocytes. The level of serum total IgE in CPHD patients with MP
infection was higher than that in patients with other infection. These data
suggest that MP is a common agent in COPD patients, particularly in CPHD and
asthma. MP infection can impair the cellular immunity and immunotherapy combined
with antibiotics may be more effective.
PMID- 10682568
TI - [Relationship between IL-1 beta and TNF-alpha in subretinal fluids of
rhegmatogenous retinal detachment with PVR].
AB - The concentrations of IL-1 beta and TNF-alpha in subretinal fluids from 49
patients with rhegmatogenous retinal detachment with proliferative
vitreoretinopathy(PVR) were measured by Enzyme-linked immunosorbent assay
(ELISA). The results showed that all subretinal fluids contained IL-1 beta, their
concentrations were positive correlation with severity of PVR (r = 0.677) and no
correlation with age, sex, holes, ranges and times of retinal detachment, TNF
alpha was detected in 18/49 subretinal fluids including 2 patients with PVR-1
beta and 16 patients with PVR-C and the above cases. It suggested that IL-1 beta
and TNF-a are involved in the pathogenesis of PVR.
PMID- 10682569
TI - [Management of hepatic trauma in 267 cases].
AB - Two hundred and sixty-seven consecutive hepatic trauma in recent 17 years were
analysed. They were classified by AAST classification: grade I and II 68 cases
(25.4%), grade III 132 cases (49.44%), grade IV 52 cases (19.48%) and grade V 15
cases (5.6%) and 237 cases were operated in different procedures according to the
severity of the trauma. More than ten modalities such as dedridement, suturing,
repairment, abdominal drainage, billiary drainage, hepatic artery ligation,
packing and pressing hemostasis, resection of traumatic parecchyma, vessel
ligation with suturing in section etc were used, The morbidity and mortality were
20.6% and 8.9%, respectively. The other 24 cases were found no active bleeding
during laporatomy and rehabitated with preservative management. The authors
believe that effective management on time and intensive perioperative care are
important to minimize the morbidity and mortality of hepatic trauma. Nonoperative
management deserves enough attention.
PMID- 10682571
TI - [Changes of serum myocardial enzymes in patients with malignant hematologic
diseases].
AB - Myocardial enzymes including aspartate aminotransferase (AST), lactate
dehydrogenase (LDH), HBD (LDH1 and LDH2), and creatine kinase (CK) and its
isoenzyme were monitored in 106 cases of malignant hematologic diseases. The
findings were that average values of LDH and HBD increased. There were 82.4%
myocardial enzyme levels of 51 patients with leukemia, lymphoma, and
myelodysplastic syndrome (MDS) returning to normal or making an obvious reduction
after chemotherapy associated with drugs of heart toxicity, while there were
increases of the myocardial enzyme levels before chemotherapy. Patients with the
increasing of enzyme levels were only 3.9% after chemotherapy. After several
courses of chemotherapy, the positive rates of the increasings of CK and CK-MB
were higher than that of pretreatment. The results suggest that the injuries of
myocardium are possible.
PMID- 10682570
TI - [Influence of isoflurane and sevoflurane on metabolism of oxygen free radicals in
cardiac valve replacement].
AB - To investigate effects of isoflurane and sevoflurane on the levels of lipid
peroxides (LPO) in plasma and superoxide dismutase (SOD) in red blood cells
during myocardial ischemia/reperfusion, and to study myocardial protection of
these two volatile anesthetcs, 30 patients undergoing cardiac valve replacement
were randomly divided into isoflurane (Group I), sevoflurane (Group S), and
controlled group (Group C). Patients of Group I were anesthetized with isoflurane
mainly, Group S with sevoflurane, and Group C with fentanyl. LPO and SOD levels
were measured at five points before and during the operation. The results were as
follows: SOD levels in all groups did not change significantly. LPO levels in
Group C increased during the operation, while in other two groups didn't. Rates
of automatical rebeating of hearts in Group C were lower than that of hearts in
other two groups. It is suggested that isoflurane and sevoflurane can inhibit
increasing of LPO levels to attenuate myocardial ischemia/reperfusion injuries
mediated by oxygen free radicals during open-heart surgery.
PMID- 10682572
TI - [Preliminary study of clinical scoring on prognosis of severe head-injury].
AB - In this article, 68 cases of severly head-injured patients scoring and prognosis
evaluation were reviewed. We have come to a practicable severe head injury index
(SHII) for first aid: the blood pressure (Bp), pulse rate (P), respiration rate
(R), degree of consciousness and reaction of the pupils are five items taken for
estimation of the patients. The highest total score was 25, the lowest was 5. If
the score was lasted for 2-4 hours below 7, and first aid non-responsive in 4-6
hours, the mortality and morbidity rates will be high. When the score is more
than 14, the first aid salvage will be meaningful. The first aid salvage will be
meaningful. The first aid had significant measing especially for those patients
whose score was over 18. The detailed method of clinical scoring is shown on
chart 2.
PMID- 10682573
TI - [Relationship between plasma NO and PaO2 of artery blood in the patients with
chronic pulmonary heart disease].
AB - The plasma nitric oxide(NO) level in the 28 patients with chronic pulmonary heart
disease and health controls were measured. The results showed that NO level in
the exacerbating patients and stable patients was significantly lower than that
in health controls. The NO level in the patients getting worse was markedly lower
than that in the stable patients. The lower the oxygen pressure of the artery
blood (PaO2), the lower the NO level. when the patient's situation was improving,
the plasma NO level increased with rising PaO2. The plasma NO level in patients
was associated with the PaO2. This study suggests that the sustained pulmonary
hypertension caused by chronic hypoxia may relate to the reduction of NO
synthesis and release, and that NO may play an important role in the pathogenesis
in chronic pulmonary heart disease.
PMID- 10682574
TI - [The applied value of BiPAP mechanical ventilation via facial of nasal mask
before or after ordinary mechanical ventilation].
AB - To expore the applied value of BiPAP ventilator before or after regular
ventilation, 44 patients who had indicators of regular mechanical ventilation and
4 patients who had difficulty of getting free from endotracheal intubation
mechanical ventilation were ventilated with BiPAP ventilator via facial or nasal
mask. The results showed that 13/44 patients had good responses and avoided
receiving regular mechanical ventilation with endotracheal intubation or
incision. BiPAP ventilation was also effective in patients who were dependent on
regular mechanical ventilatin.
PMID- 10682575
TI - [Bcl-2 mRNA expression in acute promyelocytic leukemia by RT-PCR].
AB - To check the anti-apoptosis gene bcl-2 mRNA expression in 20 APL patients by PCR,
and analyse the relationship between bcl-2 mRNA and the PML-RARa isoform. The
result is that the bcl-2 mRNA expression has no significance between the isoforms
(P > 0.05). This shows that the PML-RARa transcription type has no influence on
the clinical features and prognosis.
PMID- 10682576
TI - [A new fluorescent scanning technique in quantitative determination of isoenzymes
of creatine kinase].
AB - To increase the sensitivity and specificity and decrease the cost on determining
the isoenzymes of creatine kinase (CK), including CK-MM, CK-MB, and CK-BB, we
used the electrophoresis bath with different buffers to isolate the isoenzymes
and used the fluorescent scanner to determine the content of each isoenzyme. We
found that the concordance appeared in sensitivity and specificity in comparison
with the MOPS electrophoretic system. There was a positive correlation between
our method and MOPS, and the cost was much less than that of the MOPS.
PMID- 10682578
TI - [Effect of different doses of succinylcholine chloride on its action duration
during rapid anesthesia induction].
PMID- 10682577
TI - [Analysis of bacterium culture and drug sensitivity test in bile of biliary tract
diseases].
PMID- 10682579
TI - [Therapeutic experience of primary inferior tracheal tumor. Report of 10 cases].
PMID- 10682580
TI - [Uses of valve patches for repairing the congenital heart defects with severe
pulmonary hypertension].
PMID- 10682581
TI - [A clinical analysis of 40 patients with the unknown origin fever].
PMID- 10682583
TI - [A case of particular-long slow pathway conduction among triple A-V nodal
pathway].
PMID- 10682582
TI - [A case of primary ovary non-Hodgkin's malignant lymphoma].
PMID- 10682584
TI - [A case of Tourette syndrome complicated with schizophrenia].
PMID- 10682585
TI - [Relationship between health status and work ability among elderly Al exposed
workers].
AB - In this study, health status and work ability of 80 elderly male workers exposed
to aluminum (Al) were assessed by physiological and neurobehaviral tests. The
results showed that workers with cardiovascular or respiratory diseases had lower
work ability index(WAI). Vital capacity and musculoskeletal function index(MSFI)
were correlated closely with work ability. Mental performance capacity decreased
with the increasing of age, and mental performance score was associated with work
ability. It is suggested that vital capacity and MSFI may serve as index
reflecting physical work ability of Al-exposed workers. Simple reaction time,
visual memory, manual dexterity and pursuit aiming may reflect mental work
ability.
PMID- 10682586
TI - [Detection of sister chromatic exchange in workers exposed to coal tar pitch and
to coke oven volatiles].
AB - In order to know the changes of genetic toxicological effects on workers
occupationally exposed to polycyclic aromatic hydrocarbons (PAHs), sister
chromatic exchange(SCE) was detected by the methods of peripheral lymphocyte
culture in 23 workers exposed to coal tar pitch (CTP) and in 19 workers exposed
to coke oven volatiles (COV) and 12 normal controls. The results suggested that
the SCE in occupational workers was significantly higher than that in controls
(11.31 vs 6.37, P < 0.001). The SCE in workers exposed to CTP and to COV was
higher than that of control (10.27 and 12.58 vs 6.37) respectively. In workers
exposed to CTP and COV, there were no differences of SCE for smokers and
nonsmokers (P > 0.05). It is indicated that CTP and COV caused strong genetic
toxicity and injury to chromosome.
PMID- 10682587
TI - [Application and analysis of biochemical indices for the evaluation of
antisilicosis treatment. Study on anti-silicosis therapy and its evaluation
research group].
AB - The levels of serum Ceruloplasmin (Cp), Superoxide dismutase (SOD) and IgG of 296
silicosis patients treated by tetrandrine, polyvinylpridine-N-Oxide,
hydroxypiperaquinoline phosphate and aluminium citrate were measured. Sera were
collected before and after the 1st, 3rd and 6th therapy courses. 144 Silicosis
patients without treatment were observed as controls. The levels of these three
indices decreased by the end of treatment. The levels of SOD were fluctuated,
which were increased after the 3rd course, but decreased after the 1st and 6th
courses. The decrease of Cp, SOD and IgG consisted with the clinical
effectiveness of the treatment, indicating that Cp, SOD and IgG were appropriate
biochemical indicators for the evaluation of antisilicosis drugs. The quality
control and the statistics standardization for data analysis are important.
PMID- 10682588
TI - [Expression of p53 and ras p21 gene products in malignant transformed V79 cell
induced by various organic components of DEPs].
AB - The effect of various fractions of diesel exhausted particles on the expression
of mutant p53 antigen product and ras oncogene p21 product was examined by
immunohistochemical method in malignant transformed V79 cell. The result showed
that all fractions of diesel exhausted particles (DEPs) could significantly
increase the expression of p53 products (P < 0.01). It demonstrated that the
organic fractions of DEPs could induce the mutation of p53 suppressor gene in
malignant transformed cells. But the expression levels of ras oncogene p21
product were not changed under the same experimental conditions (P > 0.05).
PMID- 10682589
TI - [Ceruloplasmin gene expression in silicotic rat lung].
AB - In order to investigate the existence of extrahepatic ceruloplasmin (Cp) gene
expression during silicotic process, molecular hybridization technique including
dot blotting, in situ hybridization and Northern blotting was used. Twenty one
days after silica dust intratracheal injection, Cp mRNA was detectable in lung,
which was nearly double the content of that in the control (saline injection). In
situ hybridization and Northern blotting revealed that the alveolar macrophages
in silicosis could express Cp mRNA. It is concluded that lung is a prominent site
for Cp gene expression during silicosis and Cp may play a previously unknown role
in pulmonary injury or repair.
PMID- 10682590
TI - [Antagonistic action of organic selenium on lead poisoning].
AB - Ninety white rats were treated with liquid lead acetate. When the concentration
of lead in urine was more than (0.81 +/- 0.26) mg/L and blood lead was more than
(4.8 +/- 0.33) mg/L, the rats were divided into three groups randomly. The
oxygenic damage indicators in serum showed SOD activity decreased and MDA content
increased. In one group of lead rats fed with an organic selenium compound (code
FCQY) the SOD activities were high and the lipid peroxidation was inhibited
compared with controls without selenium supplementation. The lead contents of
bone, kidney and liver were measured. The results suggested that the organic
selenium compound could interfere with the absorption and accumulation of lead.
PMID- 10682591
TI - [Study on the psychological status of video display terminal operator].
AB - Occupational psychological test designed by the Labour Hygiene Department of West
China University of Medical Sciences was applied to survey the mental health of
516 video display terminal (VDT) workers and 396 control workers in Chengdu. The
results showed that mental health level of VDT workers was higher than that of
controls. In the somatic disorder, anxious and hostile are increased obviously.
With the prolonging of operating hours per week, somatic disorders, depression
and obsession are increased, especially when VDT operating time is more than 30
hours per week and operating on VDT is more than ten years. This indicates that
the operating hours should not be more than 30 hours per week. It is found by
multiple factors analysis of data that the main adverse effects on mental health
are age and VDT operating time.
PMID- 10682592
TI - [Effect of manganese on the growth and development of rat offspring].
AB - Effects of Manganese exposure to pregnant rats on the growth and development of
their offsprings were as follows: (1) the gain of body weight and brain weight in
the high dose Mn-exposed offspring was significantly lower but the ratio of brain
to body weight was significantly higher; (2) in Morris Water Maze Test, the
average latency to find the hidden platform in the high dose Mn-exposed
offsprings was obviously reduced during the first 5 days. But on the non-platform
test day, a much longer length of swimming in the quadrant in which the hidden
platform was located previously, although no difference was found for the total
distance between them; (3) the immunoreactivity of glial fibrillary acid protein
and the average density of its products in hippocampus of both the low and high
dose Mn-exposed groups, especially of the high dose one, was significantly higher
than that of the control group.
PMID- 10682593
TI - [Relation between methylmercury chloride-induced programmed cell death and the
development of nervous system in rats].
AB - The study was designed to reveal the role of programmed cell death (PCD, or
apoptosis) induced by methylmercury chloride (MMC) in SD rat embryos, wish TdT
mediated dUTP nick end labeling (TUNEL), Nile blue sulfate (NBS) vital stailing
electron microscopy (SEM) and in vivo teratogenic methods (TEM). Pregnant rats
were intraperitoneally injected at gestation day 9.5 with doses of 0, 0.2, 0.4,
0.8, 1.6 and 3.2 mg/kg MMC and killed at 11.5 day later. Results showed that the
PCD of embryonic nervous system was apparently dose dependent with MMC during rat
head-fold stage. Observations under SEM and TEM showed that MMC caused pathologic
changes of epithelia and organellae in embryonic brain such as atrophied or
decreased microvilli cavernous damages and mitochondrial swelling and so on.
Though MMC could result in developmental anomalies of embryonic brain and other
organs, the main defect was open neural tube. The experiment study suggested that
over PCD may be one of the teratogenic mechanisms of MMC on rat embryos,
developing brain in particular.
PMID- 10682594
TI - [Determination of tetradecyl pyridyl bromide in waste water by flame atomic
absorption spectrometry].
AB - A indirect method for the determination of tetradecyl pyridyl bromide (TPB) was
established (TPB) by flame atomic absorption spectrometry (FAAS). TPB was
combined with cadmium tetrathocyanate to make neutral ion association compounds,
which are extracted into xylene. The concentration of TPB can be indirectly
determined by the absorption of cadmium in xylene layer with flame atomic
absorption spectrometry. The linear range of TPB is 0.03-0.80 mg/L. The
sensitivity is 0.0212 mg/L x 1%. When the method was applied to the analysis of
waste water, the recovery is from 98% to 104% and the RSD is less than 9.16%.
PMID- 10682595
TI - [Effects of low temperature storage on DNA migration assayed by single cell gel
electrophoresis].
AB - V79 cells treated with potassium dichromate and control cells were stored at 4
degrees C, -20 degrees C, -80 degrees C and -196 degrees C. Single cell gel
electrophoresis (SCGE) was carried out after preserving cells for 0, 4, 24, 48
and 168 hours. The results showed that there was no difference on DNA migration
between cells processing immediately after trypsinization and cells preserving
for 24 h at different low temperatures. Longer storage (48 h or 168 h) resulted
in a significant increase in the length of DNA migration and decrease in cell
viability. The results suggested that 4 degrees C is more convenient for less
than 24 h storage without influence on DNA migration and -80 degrees C is better
for longer storage to minimize the influence on DNA migration.
PMID- 10682596
TI - [Effects of opium peptide system on the temperature regulation of mice under dry
hot environment with different temperature].
AB - The Kunming mice were selected as subjects. Animals were allowed to move and
drink freely. The Naloxone(0.02 mg/g) was injected by abdominal cavity. The
ability to body temperature stable by mice under the environment with high
temperature (41 degrees C, 43 degrees C) was observed. The results showed that
after obstructing opium receptor by Naloxone, the ability mentioned above was
reduced obviously.
PMID- 10682597
TI - [Effect of dietary calcium on serum calcium and calmodulin activity of brain and
hypothalamus in rats].
AB - The effect of low calcium (LC) diet supplemented with various amount of calcium
on serum calcium and calmodulin of rats was studied. The LC diet was mainly
composed of corn low in calcium. The calcium content of LC diet was only half of
that of the stock diet. Seventy Wistar rats were divided into 7 groups by weight
and sex. Results showed that serum calcium in LC group was low and calmodulin
activity was also low. These parameters were improved while calcium was
supplemented in LC diet. There is a significant dose-response relationship among
diet calcium, serum calcium and growth. When the total calcium in diet was
increased up to 1000 mg/kg, serum calcium level was closed to that of normal and
higher than the serum calcium in LC group significantly. The study demonstrated
that low dietary calcium, hypocalcemia and low calmodulin are associated. When
total dietary calcium was up to 1000 mg/kg, the growth retardation was
attenuated.
PMID- 10682598
TI - [Study on the contamination level and the tolerable limit of mould and yeast in
yoghurt].
AB - The results show that 67.33% of yoghurt samples collected from factories,
supermarkets and retailers are contaminated by mould and yeast. The main problem
of yoghurt product is yeast contamination (56.67%). The highest count of mould
and yeast in the positive samples are 39,500 cft/ml and innumerable,
respectively. There is a significant difference in the levels of contamination of
mould and yeast between yoghurt filled in the glass bottles and that in the
plastic bottles (P < 0.005). According to the results above, it is suggested that
the tolerable limit of mould and yeast in yoghurt should be equal to or less than
50 cfu/ml.
PMID- 10682599
TI - [Mutation of p53 gene in human fetal gastric mucosal cells by sterigmatocystin in
vitro].
AB - Cell culture, flow cytometry and silver-staining PCR-SSCP methods were used to
explore the effects of sterigmatocystin(ST) (1 mg/L and 3 mg/L) on carcinogenesis
and mutation of tumor suppressor gene p53 in human fetal gastric mucosal cells in
vitro. Four weeks after treated with ST, the cells showed vigorous growth and
malignant transformation foci. Twenty-four weeks after ST treatment, the cells
could form cellular colonies in soft agar(the mean colony number was 15 and 17
perdish for ST 1 mg/L and 3 mg/L groups respectively). Flow cytometric analysis
showed that both proliferation indexes (PI) and the cellular DNA contents of ST
treated cells were much higher than those of normal control. The DNA contents of
ST treated cells were in DNA aneuploid range. Mutant p53 protein expression was
also significantly higher in ST treated cells. Silver-staining PCR-SSCP analysis
showed that abnormal electrophoretic migration bands could be seen at exon 8 of
p53 gene in ST-treated groups 22 weeks after ST treatment, while no abnormal
bands were found in control group. Thus, the results further confirmed the
carcinogenic effects of ST on human fetal gastricmucosal cells.
PMID- 10682600
TI - [Study on the antimutagenicity of curcumin].
AB - Curcumin is a coloring additive used in food, which has many biological
functions. In order to provide basic information on its anticarcinogenicity, the
antimutagenicity of curcumin was determined by Ames test and micronuclei test.
The results indicated that curcumin (60-250 micrograms/plate) inhibited the
revert mutant induced by 2, 7-diaminofluorene (2AF) with S-9 in TA98 and in
TA100. The inhibitory rates are 29.5%-55.9% and 37.5%-59.1% respectively. Before
the injection of cyclophosphamide (CP), mice were given with curcumin (60, 120,
and 240 mg/kg) orally once a day for a week. The results revealed that curcumin
reduced the micronuclei formation induced by CP. The inhibitory rates of curcumin
are 43.7%, 56.9%, and 63.9% respectively, which are different from that of the
positive control significantly.
PMID- 10682601
TI - [Determination of taurine in foods by high performance liquid chromatography].
AB - Taurine (2-aminoethanesulfonic acid) was quantitated by reversed-phase liquid
chromatography on a C18 resolve column (ZOBAX ODS) using a mobile phase of methyl
alcohol-phosphate buffer (pH = 4.9). L-glutamine was used as the internal
standard. Before separation, the sample was extracted with 0.2 mol/L
sulfosalicylic acid solution and cleaned up with dual ion exchange column
chromatography. The amino acid was derived with o-phthalaldehyde to form an amino
acid adduct which was monitored at 340 nm by UV detector. The HPLC method for
taurine analysis in foods showed the precision (relative standard deviation) is
better than 5%. The recoveries are more than 95% and the detection limit is 12 ng
of taurine.
PMID- 10682602
TI - [Impact of maternal income on the nutrients intake of preschool children--a case
study in 8 provinces of China].
AB - The data of this study are based on the project "China Health and Nutrition
Survey" carried out in 8 provinces of China from 1989 to 1998 in collaboration
with the University of North Carolina at Chapel Hill, USA. Totally, 1180 and 916
mother-child pairs aged 2-6 were investigated in 1991 and 1993 respectively.
Descriptive and stratified analysis is applied to investigate the impact of
maternal income on the nutrients intake of children. It is found that the
nutrients intake of children in higher maternal income group is greater than that
in lower maternal income group. After adjusting for family income, the results
show that the more contribution of the mother's income to the family, the more
nutrients intake of their children, especially in lower income families. It is
illustrated that the income of mother may be more important for children's
dietary status than that of other members of the family.
PMID- 10682603
TI - [Survey on breakfast-eating behavior among residents in Beijing, Guangzhou and
Shanghai].
AB - A survey of breakfast-eating behavior among residents in Beijing, Guangzhou and
Shanghai was carried out in 1994-1995. The results showed that the breakfast
eating rates in three cities were 74.8%-90.5%. Subjects aged below 35 years
skipped breakfast more often. "Time limiting" in the morning became the main
cause of breakfast-skipping. Nearly half of subjects in three cities got their
breakfast out of home. Moreover, compared with two years ago, the present rates
of eating outside increased at various levels in three cities. Steamed bun, bread
and congee were main foods consumed at breakfast. In addition, 39% to 56% of
subjects often drank milk. Through this survey, the authors got an all-round
understanding on breakfast-eating rates, eating outside rates and variety of food
consumed of residents in 3 cities. This survey will also provide a background for
nutrition intervention and education in the future.
PMID- 10682604
TI - [Comparison between selenomethionine and sodium selenite on action potentials of
cultured myocardiocytes].
AB - The action potentials of ventricular myocardial cells were recorded with glass
microelectrodes inside the cells from neonatal Wistar rats treated with
selenomethionine and sodium selenite in concentrations of 1.0, 2.0, and 4.0 mg/L
selenium. Both of selenomethionine and sodium selenite decreased the action
potential parameters, such as action potential amplitude(APA), overshoot(OS),
threshold potential(TP), maximum diastolic potential (MDP) and maximum rate of
depolarization (Vmax). Selenomethionine decreased the action potential duration
at 10%, 50% and 90% repolarization (APD10, APD50 and APD90), while sodium
selenite prolonged APD10, APD50 and APD90 at dose of 4.0 mg/L selenium and
decreased APD50 and APD90 at dose of 1.0 and 2.0 mg/L selenium. The results
indicated that both sodium selenite and selenomethionine inhibit the
transmembrane movement of Ca2- and sodium selenite also inhibits transmembrane
movement of K+.
PMID- 10682605
TI - [Study on certified reference material of germanium in Ganoderma lucidum].
AB - Analytical reference material of Ge in Ganoderma lucidum is designed and prepared
for accurete analysis, monitoration and evaluation in trades of farming,
forestry, medicine and food hygiene for Ge. It is used in technical training,
technical assessing, monitoring, data arbitrating and analytic method verifing
for professional supervisors. This reference material has been certified by
graphitic oven atomic absorption spectrometry, hydride spectrophotometry,
polarography, chemical separation spectrophotometry, atomic fluorescence method
and x-ray fluorescence method. According to Grubb's law to judge the data of each
group, it is confirmed that all of seven groups certified crude data are normal
distribution by checking normality D. The arithmatic mean value of all data is
0.38 microgram/g. Standard deviation is 0.08 microgram/g.
PMID- 10682606
TI - [Study on certified reference material of benzene, toluene, o-xylene in
charcoal].
AB - This certified reference material (CRM) of benzene, toluene and o-xylene in
charcoal is used for quility control and calibration of analytical instruments in
the determination of benzene, toluene and o-xylene in air. Homogeneity of
benzene, toluene and o-xylene concentrations in the CRM was testes by GC. The
stability of the CRM was assessed for one year. The certified values are based on
analysis made by a group of independent laboratoies using GC method.
PMID- 10682607
TI - [Research and production of air cleaner for traveller train carriage].
AB - After the traveller train carriage is closed, the air pollution would be serious
in the carriage. In order to control the air pollution, the air cleaning
technology must be studied and the air cleaner for the carriage must be designed.
The authors discussed. 1. Working out a technology scheme and main technology
parameter for the air cleaner, and the structure design of the air cleaner. 2.
Texting the function and performance of the air cleaner. 3. Investigating the
effectiveness of the cleaner in same train sections. Thereby it will be confirmed
that the air cleaner can improve the air environment in the carriage, and give
convincingly security to the health of attendants and travellers.
PMID- 10682608
TI - [Study on the relationship between deoxyribonucleoside triphosphate (dNTP) pools
and cell transformation].
AB - Deoxyribonucleoside triphosphate (dNTP) pools were measured in normal BALB/c3T3
cells, transformation-treated cells and transformed cells with reverse-phase
HPLC. The fluctuation of dNTP pools was similar after cells were treated with
alkylating mutagens glycidyl methacrylate (GMA) and N-methyl-N'-nitro-N
nitrosoguanidine (MNNG). The gap between (dGTP + dATP) pools and (dTTP + dCTP)
pools was greatly intensified. The measurements also indicated that the dNTP
pools in transformed cells were quite different from those in normal cells. The
results suggest that dNTP pools may play an important role in cell
transformation.
PMID- 10682609
TI - [Study on inhibition and prevention of tumor and antioxidative effects of lithium
carbonate in tumor bearing mice].
AB - Two Kinds of tumor-bearing mice (hepatoma H22 and sarcoma S180) were administered
with lithium carbonate (Li2CO3) for 17 or 10 days (advanced and simultaneous
administration), in order to observe the effects of prevention and treatment of
Li2CO3 on malignant tumor, as well as the relationship between Li2CO3 and lipid
peroxidation in tumor-bearing mice. Meanwhile, we compared the toxic and side
effects of cyclophosphamide (CP) with that of Li2CO3. The results showed that
Li2CO3 had no significant toxic or side effects with the suggested doses. In the
tests of inhibition and prevention of tumor, Li2CO3 could significantly inhibit
the grouth of the two kinds of tumor, and increase the activity of superoxide
dismutage (SOD) and decrease the contents of Malonyldialdehyde (MDA). In
addition, Li2CO3 had no effect on the white blood cells (WBC) and decreased the
micronucleus frequency (MNF) in bone marrow polychromatic erythrocytes (PCE),
while CP had definite effect of decreasing the WBC and increasing the MNF in the
tumor-bearing mice.
PMID- 10682610
TI - [Observation of inducing effect of five kinds of soft wood dust in micronucleus
test].
AB - The authors investigated the micronucleus frequencies (MP) in peripheral
lymphocytes in 584 workers exposed to five kinds of soft wood dust and found that
all kinds of soft wood dust could increase the micronucleus frequency. As the
control's 95% confidential upper limit > or = 0.4% is defined as the standard for
positivity the micronucleus positive frequency (MPF) in the exposure group is
much higher than that in the control group (P < 0.01). Meanwhile the increase of
exposure years may increase the MP, and the time-response relationship is evident
(r = 0.90, P < 0.01). For different exposures, the MPFs are: 36.2% for linden,
26.3% for fir. 15.7% for lacebark pine, 9.6% for birch and 2.1% for polar. The
positive rate of linden and fir exposure are significantly higher than that of
the control group (P < 0.01). Water extract of these five kinds of soft wood dust
can increase the frequencies of micronucleus in polychromatic red blood cell in
mice's sternum marrow, which also showed a dose-response. The correlation
coefficients are: 0.86 for linden 0.6 for fir, 0.39 for lacebark pine, 0.76 for
birch and 0.73 for polar. All but the lacebark pine have the P value less than
0.01 (P < 0.01). At the dose of 15 g/kg body weight, micronucleus frequency
induced by linden was the highest (0.8%), next were fir (0.71%), birch (0.65%),
lacebark pine (0.63%), and polar (0.43%). The results from animal test are
consistent with those from the exposure workers. These results suggest that there
are some substances in soft wood which can induce chromosome aberration.
PMID- 10682611
TI - [Study on electroneuromyography of 175 workers exposed to carbon disulfide].
AB - A study on electroneuromyography of 175 workers exposed to carbon disulfide
demonstrated that electroneuromyographic abnormalities of these workers were in
accordance with characteristic alteration of axonal polyneuropathy.
Electroneuromyography was an objective and sensitive method to detect the early
damage of peripheral nerve caused by low-level exposure to carbon disulfide. The
dose-response relationship between the exposure to carbon disulfide and the
damage of peripheral nerve was demonstrated.
PMID- 10682612
TI - [Study on method of sampling and analysis of trichloroaniline in the air].
AB - Trichloroaniline in the air was collected with 50% ethanol and separated with a
column OV-17:OV-210 ECD as a detector. The best conditions of sampling and
determining were selected through the orthogonal experimental design. The
detectable limit was 0.01 mg/L. When the concentration of trichloroaniline in the
air was 0.5-10 mg/L, the relative standard deviation (RSD) was 4.3%-3.7%. There
was a linear relation within the range of 0.02-40 mg/L. The sampling efficiency
was 99.1%-100%. The samples were stable for at least 15 days. It is proved that
this method is accurate, fast, simple and sensitive. It is suitable for the
determination of trichloroaniline in the air.
PMID- 10682613
TI - [Role of programmed cell death in mediating arsenic-induced rat embryo
anomalies].
AB - With a view to further investigating teratogenicity, embryotoxicity and
teratogenic mechanism of arsenic on developing embryos, the relationship between
apoptosis (programmed cell death, PCD) and arsenic-induced teratogenesis was
studied during head-fold stage by using in situ 3'end-labeling of DNA and Nile
blue sulfate (NBS) vital staining. Sprague-Dawley rats were intraperitoneally
injected on gestation day 9.5 with doses of 0, 1, 4 and 8 mg/kg arsenic
respectively, and killed at day 12, the results show that teratogenic incidence
and mortality increased to 35.7% and 23.8% respectively, in apparent dose-effect
relationship. In NBS staining experience, it was found that arsenic induced PCD
in many areas, which related with abnormal development of brain, optic system,
somite segmentation, limb bud and so on. In situ 3' end-labeling of DNA further
supported above-mentioned results. The positive rate of apoptotic cell death was
up to 55.6% (P < 0.05). This research suggested a positive correlation between
abnormal PCD and teratogenesis. It may be seen that over-apoptosis is one of
teratogenic mechanisms of arsenic. Moreover, our results show that necrosis plays
some role in teratogenesis as well.
PMID- 10682614
TI - [Study of ozonization effects on mineral water components].
AB - The disinfection effects of ozonization and its influences on chemical components
of mineral water were investigated. The results showed that ozone at the level of
0.5 mg/L and with the exposure time of 5 minutes effectively destroyed bacteria
in mineral water. High level ozone showed no strong influences on some beneficial
components, such as strontium and metasilicate and on some main components, such
as bicarbonate, hardness and alkalinity, but slightly elevated pH value.
Ozonization reduced the contents of total dissolved solids and oxygen demand, and
decomposed some reductive contaminants such as ammonia, cyanide and phenols.
Ozonization will convert part of the bromide into hypobromite and bromate.
PMID- 10682615
TI - [Effects of static magnetic fields on free radical metabolism of human body].
AB - The effects of static magnetic fields at 150 to 155 mT on the activities of
superoxide dismutase (SOD) and the contents of maglonydiadehyde (MDA) in the
serum and the activities of glutathione peroxidase (GSH-Px) in the whole blood
were observed in the healthy volunteers. The results showed that the activities
of SOD and GSH-Px were significantly increased, and the content of MDA was
significantly decreased in short term at the observed magnitude of static
magnetic fields. The results suggest that the function of the free radical
metabolism of human body could be improved by static magnetic fields at that
magnitude.
PMID- 10682616
TI - [Detection of microcystins in source and tap water from a lake].
AB - The microcystins in source and tap water collected from seven waterworks around a
lake in summer, 1996 were detected by enzyme-linked immunosorbent assay (ELISA).
Microcystins were determined in the source water from all the seven waterworks,
and the concentrations ranged from 280 to 35,300 ng/L. Low concentrations of
microcystins were also detected in the tap water of three waterworks. The results
suggest that microcystins in source water could not be removed completely by
conventional adding bleaching powder treatment.
PMID- 10682617
TI - [A rapid simple and reliable method for sequencing the targeted gene of shuttle
vector pSP189].
AB - The authors established a simple, rapid and effective procedures for sequencing
the targeted a-gene SupF TRNA of shuttle vector pSP189, which is very important
and useful in molecular mechanism research of mutagens. In this method, double
stranded plasmid DNA as template, prepared single-stranded DNA with alkali
denaturation, applied r-32P-ATP for labelling 5'-end of primer, were used. A
satisfactory result was achieved.
PMID- 10682618
TI - [Efficacy of beta-carotene on lipid peroxidation induced by N
nitrosodimethylamine in rats].
AB - The effect of beta-carotene (beta-C) on lipid peroxidation induced by N
nitrosodimethylamine (NDMN) in rats was studied. Thirty clear conventional SD
rats were randomly devided into 3 groups and were intragastricly given daily
water (10 ml/kg). NDMN (1.75 mg/kg), and NDMN (1.75 mg/kg) plus beta-C (25 mg/kg)
respectively. The results showed that: compared with group 1, the activities of
SOD and GSH-Px in NDMN group were significantly decreased (P < 0.05), the values
of MDA and ROOH increased (P < 0.05). The activities of SOD and GSH-Px in group 3
were significantly higher and the contents of ROOH and MDA were significantly
lower than that of NDMN group (P < 0.05). These results suggested that free
radicals and lipid peroxidation may be a carcinogenic path for NDMN and other
nitrosamines. beta-C had ability to inhibit the lipid peroxidation induced by
NDMN.
PMID- 10682619
TI - [Scavenging effect of total flavonoids of lycium barbarum L on active oxygen
radicals and inhibitory effects on heat output from L1210 cells].
AB - The scavenging effects of total flavonoids of Lycium barbarum L. (TFL) were
studied by using ESR-spin trapping technique and the inhibitory effects on heat
output of both polymorphonuclear leukocyte(PMN) respiration burst and L1210 cells
were measured by using microcalorimetric technique. TFL (0-217 mg/L) could
scavenge O2-. in xanthine/xanthine oxidase (Xan/XO)system, with scavenging rate
of 0-51%. TFL(7.5-200 mg/L)could scavenge OH. produced in Fenton reaction and the
scavenging rate is between 20% to 72%. Those effects were concentration
dependent. Furthermore, TFL(0.56 g/L)could completely inhibit the heat output
from PMA-stimulated PMN and TFL(1.0-5.0 g/L)could inhibit the heat output from
L1210 cells.
PMID- 10682620
TI - [Effect of zinc on cadmium-induced fetal damage].
AB - The effect of different zinc level on cadmium (Cd)-induced fetal damage was
studied in pregnant rats. Seventy Waster rats were divided into five groups: zinc
30 mg/kg diet, zinc deficiency (3.2 mg/kg), zinc deficiency with Cd 2.0 mg/kg,
zinc 30 mg with Cd 2.0 mg and zinc 227 mg with Cd 2.0 mg. The pregnant rats were
killed on the 20 th day of gestation. Blood samples were taken and all the
fetuses were examined. The result showed that zinc deficiency could induce fetus
absorption or malformation, which were increased significantly in zinc dificient
plus Cd rats. Fetuses can be protected if high dose of zinc (227 mg/kg) is given.
The occurrence of fetus absorption and malformation decreased and survival
increased in compared with the nonsupplemented group. The results suggested that
fetal malformations can be induced by zinc deficiency, and being worse when Cd is
added. Zinc supplementation can offset to some extent the toxic effect of Cd.
PMID- 10682621
TI - [Behavioral-teratological effects of caffeine on mice].
AB - Pregnant ICR mice were exposed to caffeine at levels of 0, 4, 20 and 100 mg/kg
during pregnancy. The behavioral-teratological tests indicated that the
retardation of development, the obstruction of early reflexes and sensation and
decline of learning ability existed in the offsprings of 20 and 100 mg/kg groups.
The number of the dead fetus increased in the group of 100 mg/kg coffeine treated
mice. No morphological changes were found.
PMID- 10682622
TI - [Relationship between the toxigenicity and ribotype distribution of Pseudomonas
cocovenenans subsp. farinofermentans].
AB - By rDNA fingerprinting technique, ribotype discrimination analysis was conducted
for exploring the relationship between the toxigenicity and ribotype distribution
of 42 strains of Pseudomonas cocovenenans subsp. farinofermentans. The results
showed that 73.8 percent of the strains were toxigenic, which were distributed
within the most ribotype and isolated from either food poisoning samples or
normal food samples. The other strains were not toxigenic; which were isolated
from normal food samples and distributed only within a few ribotypes. Since the
most clones of P. cocovenenans subsp. farinofermentans were toxigenic, their
potential hazard should be concerned.
PMID- 10682623
TI - [Research on detection of type C2 staphylococcus enterotoxin in food with
piezoelectric immunosensors].
AB - Using the biosensor of immobilization of antibody by Piezoectric Immunosensors
(PEI) method, the concentration of antigen was determined. When the concentration
of antigen was 10 micrograms/L-2 mg/L, the linear response was found. When the
sensor was applied to detect type C2 staphylococcus enterotoxin in food, the
method was proved with high specificity and selectivity.
PMID- 10682624
TI - [Association of apoB levels and nutrition of coronary heart disease patients].
AB - Blood lipids and apo B levels were measured on 101 Coronary Heart Disease
patients and 100 controls. The results showed that the apo B levels of patients
were higher than that of controls. The average values were (877 +/- 129) mg/L and
(800 +/- 95) mg/L respectively. It was found that there was close association
among body mass index(BMI), ratio of waist circumference to hip
circumference(WHR) and apo B levels. Besides, the results showed that dietary
habit of "eating fat meat" might result in the increase of apo B concentration
while the VC intake was negatively associated with serum apo B levels.
PMID- 10682625
TI - [Catalytic spectrophotometric determination of trace manganese in theragran-M
with Mn (II)-KIO4-NTA-coomassie brilliant blue G250].
AB - A new indicator reaction is developed on the basis of manganese catalyzed
oxidation of coomassie brilliant blue G250 by potassium periodate with
nitrilotriaetic acid as an activator. The detection limit for manganese is 6.76 x
10(-8) g/L. The linear range of determination is 0.02-0.30 microgram/25 mL.
PMID- 10682626
TI - [Determination of serum copper by atomic absorption spectrometry sensitized with
mixed surfactants].
AB - The effects of six kinds of surfactants were studied in the detection of copper
in serum by atomic absorption spectrometry. The results demonstrated that the
absorption decreased when polyvinyl alcohol was used alone or together with the
other one, and the absorption increased when one or two of Tween-20, emulgent-OP,
palmityl trimethyl ammonium bromide, arabicgum and sodium laurylsulfate were
used. Tween-20 and sodium laurylsulfate used together are most effective. A
method of determination of serum copper by atomic absorption spectrometry
sensitized with mixture of Tween-20 and sodium laurylsulfate was established. The
absorption increased by 50%. The relative standard deviation was 1.35%-2.11%. The
recovery was 98.00%-98.13%. The detection limit was 0.0524 mumol/L.
PMID- 10682627
TI - [Protein status and antioxidant capability of residents in endemic and nonendemic
areas of Keshan disease(KD)].
AB - From a survey of residents in endemic and nonendemic areas of Keshan disease(KD),
it was found that the plasma cystine, tryptophan and lysine as well as blood
selenium content were lower, while the plasma lipid peroxide was higher in
endemic areas than those in non-endemic areas. These results suggests that the
selenium deficiency coexisting with cystine and tryptophan insufficiency
decreases the antioxidant defense of the organism and may be one of the important
factors for the development of KD. The role of sulfur-containing amino acid in
antioxidant defense is discussed emphatically.
PMID- 10682628
TI - [Comparative study on the retention effect of the inhaled mineral and coal dusts
in rat lung].
AB - The pulmonary retention and physico-chemical characteristics of the dust are very
important factors in the occurrence of pneumoconiosis. This paper reports a
comparative study on the retention characteristics between the inhaled mineral
dust and coal dust in rat lung. The dust quantities in the lungs and the
mediastinal lymphatic nodes were determined by the formic acid digestion method.
The results showed that the pulmonary retention quantities of the coal dust in
rats were higher than those of the mineral dust on the third day but lower on the
90th day after exposure for two weeks. The results suggest that the mineral dust
can deposit in the lung longer than the coal dust, and the lymphatic system is
important for the pulmonary elimination of the dust.
PMID- 10682629
TI - [Development of the certified reference material of iodine in lyophilized human
urine].
AB - Urine samples from normal level and low level iodine districts were filtered,
homogenized, dispensed, lyophilized and radio-sterilized. Homogeneity test,
stability inspection and certification were conducted using a spectrophotometric
method. The physical and chemical stability of the CRM (Certified reference
material) were assessed for one year. The certified values are based on analysis
made by five independent laboratories using three different principle methods.
The certified values +/- uncertainties are as follows: low level is (121 +/- 14)
micrograms/L, normal level is (201 +/- 11) micrograms/L.
PMID- 10682630
TI - [Detection of K-ras oncogene mutations in human lung cancer by PCR-SSCP-DNA
direct sequencing].
AB - K-ras oncogene mutations were detected with PCR-SSCP-DNA direct sequencing
technique in 40 cases of lung cancer. The result of PCR-SSCP silver staining
indicated that the mutational rate was 30% (12/40), all mutations were observed
in lung adenocarcinoma and its mutational rate was 44% (12/27). The result of DNA
direct sequencing showed that 11 of the 12 positive samples screened by PCR-SSCP
had mutation and 90% of K-ras mutations were in codon 12. The mutation was mainly
G-->T transversion and G-->A transition. The study suggested that SSCP silver
staining analysis is very useful in screening large amount of samples
simultaneously and PCR-SSCP-DNA direct sequencing method is quite efficient for
the detection of oncogene mutation.
PMID- 10682631
TI - [Study on the changes of heart-rate in lead-exposed workers].
AB - ECG examination and questionnaires survey were performed among lead-exposed
workers in order to assess whether moderate occupational lead exposure may cause
autonomic nervous system (ANS) dysfunction. The tests included; 1. heart-rate
response to Valsalva manoeuvre (HR-V); 2. heart-rate variation during deep
breathing (HR-DB); 3. immediate heart-rate response to immediate stand up (30:15
or Max:Min). The results did not show any evidence that lead exposure is related
to ANS dysfunction. There was no significant difference between the exposed
workers and controls who were with the same ages (P > 0.05). The important cause
for ANS dysfunction was aging.
PMID- 10682632
TI - [Evaluation on the effects of water defluoridation measures in China. Research
Group Evaluation on the Effects of Water Defluoridation Measures in China].
AB - In order to find out the situation of management and application of water
defluoridation measures, as well as the effects on the prevention of endemic
fluorosis in 10 provinces and cities with heavy endemic fluorosis from the
drinking water sources, 1960 water engineering projects accounting for about 10%
of all projects were investigated. The authors applied uniform method, criteria
and forms to carry out the retrospective investigation. The data were entered
into the computer database and analyzed statistically. The results demonstrate
that all the defluoridation projects have significant effectiveness on the
prevention of endemic fluorosis. The concentrations of water fluoride were below
1 mg/L. The prevalences of dental fluorosis were 30%-40% and the main type was
light dental fluorosis. But with the time prolonging, less attention has been
paid in man.
PMID- 10682633
TI - [Genetic epidemiological study of asthma in general].
AB - With theory and method of genetic epidemiology, data of 641 nuclear families on
asthma were analysed, and the results showed that the history of parents asthma
was one of risk factors about offsprings asthma, and the risk was 4.0-8.0 times
higher (P < 0.01), compared with the one of offsprings of parents with no asthma.
The effect of parents with asthma on the risk of sons was the same as one of
daugters. The result declared that the airway responsiveness of parents did not
relate to the one of offsprings. The results suggest that the genetic factors
play an important role in the asthma.
PMID- 10682634
TI - [Effects of low concentration ozone on the respiratory system of mice].
AB - Effects of low concentration of O3 on the respiratory system in mice were studied
in the present study. Mice were exposed to 0.1, 0.25 and 1.0 mg/m3 of O3,
respectively for 8 h per day for 3 days. Cilia in brochia, Lipid peroxide (LPO)
in lung tissue and phagocytic function of macrophage in mice were examined. The
results showed that there were cilia damage in the 1.0 mg/m3 group and swelling
of mitochondrias as well as endoplasmic reticulums in the 0.25 mg/m3 group. But
no damage was found in the group of 0.1 mg/m3. Furthermore, phagocytic rates in
the 0.25 and 1.0 mg/m3 groups were significantly lower than that of control group
(P < 0.01). No differences in LPO leads were found.
PMID- 10682635
TI - [Data cleaning in the 1995-1996 national smoking prevalence survey].
AB - The authors introduced the procedure of data cleaning in the 1995-1996 national
smoking prevalence survey, and the objectives, principles, procedures, quality
evaluation and points for attention of data cleaning were summarized. Data
cleaning must be carried out from the smallest investigative unit. The logical
relationship among variables must be fully considered for the revision of
incorrect values. In dealing with miss values, their roles in the statistical
analyses must be evaluated. Comparing the differences in some important variables
before and after cleaning is a useful method for assessing whether the
representativeness of the data has been changed during the cleaning process.
PMID- 10682636
TI - [Emergency measures on drinking water sanitation for mitigation of flood and
waterlogging disasters].
AB - This article reports the emergency measures for mitigation during flood and
waterlogging disasters to ensure drinking water sanitation and to prevent
infectious disease outbreaks. Five preparatory and preventive measures for flood
and waterlogging disasters include the construction of dual-purpose water supply
installation for ordinary and disaster use, the storage of qualified technicians
and materials (or their inventories), and the formulation of predetermination
programme for disaster relief, ect.
PMID- 10682637
TI - [The combined effects of MCYST and water organic pollutants on the co-induction
of SHE cell transformation and expression of Ras P21 protein].
AB - The authors studied the combined carcinogenic activities of MCYST and organic
pollutants in water of Dianshan Lake, using in vitro Syrian hamster embryo (SHE)
cell transformation and immunohistochemical assays. The results showed that MCYST
alone could not induce SHE cell transformation, but it increased the effects of
low dose organic pollutants in cell transformation in a dose-dependent manner. In
the cells isolated from type II transformed foci, ras P21 protein showed a
positive immunohistochemical staining. It suggests MCYST may be a tumor promoter,
which has a synergistic carcinogenic activity organic pollutants in water and the
activation of ras oncogene may be one of the factors inducing malignant
transformation.
PMID- 10682638
TI - [Effects of selenium polysaccharide and sodium selenite on blood selenium
concentration and liver cytochrome P450 monooxygenase system in rat].
AB - The effects of selenium polysaccharide and sodium selenite administered by single
or repetitive intraperitoneal injection (i.p.) on blood selenium concentration,
the activities of liver cytochrome P450, b5 as well as NAD(P)H cytochrome C
reductase, glutathione S-transferase and glutathione were studied in rats. The
biological effects of selenium polysaccharide and sodium selenite were also
compared. The results indicated that the blood selenium concentration was
increased rapidly and reached the peak in 2 hours followed by gradual decline
after selenium polysaccharide and sodium selenite were i.p. injected at a dose of
Se 0.6 mg/kg. The absorption and eliminating rates of Se from sodium selenite
were faster than that from selenium polysaccharide. Administration of selenium
polysaccharide and sodium selenite at a dose of 0.2 mg/kg by i.p. increased the
blood selenium concentration to 2.6 and 2.1 times of those of control group,
respectively, and the blood selenium concentration of selenium polysaccharide
group was significantly higher than that of sodium selenite group (P < 0.05). The
activities of liver cytochrome P450, b5 and GST were inhibited by selenium
polysaccharide and sodium selenium in vivo and in vitro experiments. Those
proteins were decreased to 57%, 70% and 62% of the control, respectively, by
selenium polysaccharide which has particularly stronger effects on cytochrome P
450 monooxygenase system (P < 0.05). The two selenium compounds did not appear to
affect the activity of NAD(P)H cytochrome C reductase. Both of the selenium
polysaccharide and sodium selenite could enhance the activity of glutathion
peroxidase significantly (P < 0.05).
PMID- 10682639
TI - [The antioxidative mechanisms of tea polyphenols in inhibiting tumor promotion by
TPA].
AB - In the mouse study, topical application of green tea polyphenols (GTP)
significantly inhibited TPA-induced increasing of epidermal ornithine
decarboxylase (ODC) and increased the activities of several antioxidant enzymes
(CAT, GR and GST). In another in vitro study, when GTP was incubated with TPA and
mice polymorphonuclear leukocytes (PMNs), TPA induced hydrogen peroxide formation
was markedly suppressed with a dose-dependent relationship. The results suggest
that the antioxidative effect of GTP may play an important role in inhibiting
tumor promotion.
PMID- 10682640
TI - [Short-term screening of anticarcinogenic ingredients of tea by cell biology
assays].
AB - By using a panel of short term cell biology assays, several ingredients of tea
(tea pigments, caffeine, tea polysaccharide, tea polyphenols tablet and mixed
tea) were screened in order to investigate their anticarcinogenic effects. The
cytokinesis block micronuclei test in V79 cells induced by mitomycin, the test of
metabolic cooperation between V79 and M cells and the test of growth ability of
Hela cells in soft agar were used in the screening. The results showed that the
six kinds of tea ingredients tested were effective in the test involved in
different stages of carcinogenesis, i.e. initiation, promotion and progression.
The effects of mixed tea and tea pigments were the strongest among the
ingredients tested.
PMID- 10682641
TI - [Study on the molecular epidemiology characteristics of Pseudomonas cocovenenans
subsp. farinofermentans isolated from China with rDNA fingerprinting].
AB - After the chromosomal DNA digestion by Bgl II and EcoRV, rDNA fingerprinting for
Pseudomonas cocovenenans subsp. farinofermentans was made using biotin-labeled
16S + 23S rDNA as a probe. Fifty one strains of P. cocovenenans subsp.
farinofermentans isolated from some areas of China were divided into 20 ribotyes,
52.9 percent of which were RT6, 9 and 2. In most cases, there were 2 or more
ribotypes in each province or city. Though same ribotypes were isolated from
different provinces, each ribotype existed in part of an area. The ribotype of
RT6 was detected in samples from 4 incidents of food poisoning in Guizhou,
Jiangsu and Hebei provinces, which indicated that these incidents may be caused
by the same clone. With discrimination and cluster analysis of ribotypes, the
rDNA fingerprinting may effectively contribute to analyzing the homogeneity of
different strains, tracing the transmission route, and exploring the evolution
and epidemiological characteristics of P. cocovenenans subsp. farinofermentans.
PMID- 10682642
TI - [The method of removing methamidophos from contaminated vegetables].
AB - Since the massive food poisoning outbreak in 1987, imported vegetables
contaminated with methamidophos continued to cause sporadic food poisoning
outbreaks in Hong Kong. Despite various administrative measures to lower the risk
of importing vegetables, it is evident that the occurrence of sporadic food
poisoning outbreaks cannot be completely stemmed out. The education of the public
on the effective ways to remove methamidophos from the contaminated vegetables
was reckoned to the another preventive measure against food poisoning. A study
was carried out to evaluate the effectiveness of various ways of treating the
vegetables before consumption. In this study, the removal of methamidophos by
simply washing with water at near room temperature was found to be a slow
process. The concentration of methamidophos was reduced by about 65% after
washing in water for an hour. Further washing did not improve the situation. The
addition of detergents and various washing aids including potassium permanganate,
hydrogen peroxide, sodium bicarbonate and vinegar did not greatly enhance the
removal effectiveness. Among the various treatment procedures, soaking in hot
water was the most effective way to remove methamidophos from vegetables. Less
than 10% of the pesticide remained in the vegetables after soaking in boiling
water for 1 minute.
PMID- 10682643
TI - [The method for the determination of fluoride in the total diet study].
AB - This paper reports a microdiffusion method using fluoride-ion selective electrode
for determination of fluoride contents in dietary samples. The method was
suitable for the determination of fluoride in different dietary samples. It was a
simple and fast method, and could be applied in large amount of sample analysis.
The minimum detectable limit of this method was 1.0 microgram fluoride in 1.0 g
dry dietary sample. The range of fluoride recovery and RSD in this dietary
samples were 85.0%-107.0% and 4.5%-9.5% respectively. The fluoride content
determined in the oyster tissue of NBS 1566 SRM was 87.9%-104.6% of certified
SRM, and RSD was 6.5%. The RSD of fluoride determination in alcohol drinks was
3.1%.
PMID- 10682644
TI - [Determination of copper, zinc, iron and calcium in wheat and maize and three
nitrogen compounds in high and low risk areas of esophageal cancer].
AB - This study reports the concentrations of copper, zinc, iron and calcium in wheat
and maize from high risk area Linzhou and low risk area Yuzhou of esophageal
cancer and three nitrogen compounds of four types of drinking water in Linzhou.
The results showed that the concentrations of zinc and calcium in wheat and maize
from Linzhou were significantly lower than these from Yuzhou, the copper
concentrations in grains were higher and the iron in maize was lower. The nitrate
N concentrations in four types of drinking water from Linzhou were below the
national standard but the nitrite and NH3-N concentrations were higher than the
national limits. The results suggest that the low concentrations of zinc, iron
and calcium and high concentrations of copper in grains as well as the high
concentrations of nitrite and NH3-N may be related to the etiology of esophageal
cancer.
PMID- 10682645
TI - [Successful treatment of an elderly woman after stubborn resistance].
AB - A 72-year-old depressed woman was admitted by court order after a long history of
?successful' resistance to any treatment, both at home and in a psychiatric
hospital. The nature of her disorder had not been recognised and she was
diagnosed elsewhere as suffering from factitious disorder, probably based on
intense countertransference. The diagnosis of depression with mood-congruent
psychotic features was made. After several unsuccessful combination treatments
and refusal of electroshock therapy, she finally responded to combination therapy
with tranylcypromine, lithium carbonate and clozapine. Dutch medicolegal
regulations need not be an impediment in such cases, intercollegiate consultation
is most useful and strict adherence to therapy guidelines is beneficial.
PMID- 10682646
TI - [The operating room of the future].
AB - Advances in computer technology will revolutionize surgical techniques in the
next decade. The operating room (OR) of the future will be connected with a
laboratory where clinical specialists and researchers prepare image-guided
interventions and explore the possibilities of these techniques. The virtual
reality is linked to the actual situation in the OR with the aid of navigation
instruments. During complicated operations the images prepared preoperatively
will be corrected during the operation on the basis of the information obtained
peroperatively. MRI currently offers maximal possibilities for image-guided
surgery of soft tissues. Simpler techniques such as fluoroscopy and echography
will become increasingly integrated in computer-assisted peroperative navigation.
The development of medical robot systems will make possible microsurgical
procedures by the endoscopic route. Tele-manipulation systems will also play a
part in the training of surgeons. Design and construction of the OR will be
adapted to the surgical technology, and include an information and control unit
where preoperative and peroperative data come together and from where the surgeon
operates the instruments. Concepts for the future OR should be regularly adjusted
to allow for new surgical technology.
PMID- 10682647
TI - [Pharmacotherapy of patients with (early) rheumatoid arthritis].
AB - As soon as the diagnosis 'early rheumatoid arthritis (RA)' is made, a disease
modifying antirheumatic drug (DMARD) should be prescribed without delay.
Methotrexate in dosages up to 30 mg once weekly is being used more frequently
than in the past, also in early RA. Combination therapy with DMARDs is indicated
in case of insufficient effect of a single DMARD. Combinations with methotrexate
appear to be especially effective, like methotrexate and cyclosporin. A novel
effective DMARD is leflunomide. In the near future promising biologicals will
probably be applied in clinical daily practice, presumably in combination with
conventional DMARDs. New non-steroidal anti-inflammatory drugs (NSAIDs) have been
developed that are probably safer than conventional NSAIDs. If the recent finding
that glucocorticoids are able to inhibit joint damage in (early) RA will be
confirmed, prednisone might be used more often in (early) RA. Bone marrow
transplantation in RA is still experimental.
PMID- 10682648
TI - [Physical diagnosis--percussion and palpation of the spleen].
AB - The accuracy of physical examination of the spleen was investigated in the
literature. Ultrasonography or scintigraphy was used to test the findings at
physical examination. Physical examination has a low sensitivity, but a
reasonably good specificity. The interobserver variability is rather high. In
general, palpation is more sensitive and specific than percussion. The findings
of percussion improve the accuracy of palpation and the combination has a high
specificity, of approximately 90%. The two should therefore be used in
conjunction. The sensitivity is much lower although it is greatly influenced by
the degree of splenic enlargement and the leanness of the patient.
PMID- 10682649
TI - [Moroccans' opinions about general practitioners: analyzing reasons for
consultation].
AB - OBJECTIVE: To determine whether there is a difference in the extent to which the
GP succeeds in establishing the reasons for consultation of Moroccans and those
of the Dutch; and whether the opinion of Moroccans about the GP's consultation
differs from that of the Dutch. DESIGN: Analysis of patient interviews and GP's
consultations. METHOD: In 11 general practices in Amsterdam and The Hague in May
1997, 50 Moroccan adults and 50 Dutch individuals were asked for their reasons to
attend before the consultation and in the mother language; a distinction was made
between the actual complaint and the expectations with regard to the
consultation. The GPs recorded these data after every consultation. The
complaints were coded by organ system and by nature of complaint, following which
agreement of the assessments was scored on a scale ranging from 0 to 100.
RESULTS: Both groups comprised 20 men and 30 women. The mean age of the Moroccans
was 38.6 years (SD: 13.8), that of the Dutch 56.4 years (SD: 16.7). The GPs
established complaints of Moroccan patients not as well as those of Dutch
patients (score: 73.9 versus 87.3); the difference was more pronounced where
patients with only elementary education were concerned (67.0 as against 86.1).
The GPs were able to establish the expectations with regard to the consultation
nearly as often for the Moroccan as for the Dutch patients (58.5 versus 55.9).
Moreover, the Moroccans were as positive about the course of the consultation as
the Dutch. Except for communication problems among the lower educated, none of
the problems indicated appeared to be experienced more often by the Moroccans
than by the Dutch. CONCLUSION: A large part of the complaints presented by lower
educated Moroccan patients were interpreted differently by the GP. For Moroccans
with a higher education, the care was comparable with that among the Dutch.
PMID- 10682650
TI - [Fewer x-rays while maintaining quality of clinical care using clinical protocols
for physical diagnosis of ankle injuries].
AB - OBJECTIVE: To determine whether it is possible to decrease the number of X-rays
in acute ankle injury while keeping the health care constant, using a scoring
system. DESIGN: Prospective. METHOD: Patients presenting in the emergency
department of the University Hospital Utrecht (AZU), the Netherlands, over a one
year period of time with acute ankle injuries were subjected to a thorough
physical examination based on a scoring system developed at Leiden University
Hospital. The score was calculated and X-ray examination was indicated when this
score was > or = 8 points. Radiological investigation or telephone interviews six
weeks after injury achieved verification of the clinically relevant ankle
fractures. Specificity and sensitivity were calculated from every possible cut
off point and drawn in a 'receiver operating characteristics' (ROC) curve.
RESULTS: Of the 514 patients included 81 patients had a score of 8 or higher and
24 of them had a clinically relevant fracture. In 34 patients an ankle X-ray was
made although their score was < 8 points. The positive and negative predictive
values of the system were 30% (95% confidence interval (95% CI): 20-41) and 99%
(95% CI: 97-100) respectively. The score yielded an area under the ROC curve of
91% (95% CI: 84-98). A cut-off point of 8 led to a reduction of X-rays by 60%
(using the 'Ottawa ankle rules' the decrease in this population would have been
28%). On the other hand, 5 clinically relevant fractures were missed. CONCLUSION:
Radiological examination in patients wit acute ankle complaints was reduced while
health care remained almost constant. In the AZU, a decision was made for a major
reduction in X-rays while accepting that some fractures would be missed.
PMID- 10682651
TI - [Systemic capillary leak syndrome].
AB - A man aged 61 had recurrent attacks of severe shock. The episodes were preceded
by symptoms such as a runny nose, epigastric discomfort with nausea, vertigo,
orthostatism and sometimes light fever. During the attacks there were marked
hypotension, a strong rise of the haematocrit, a decrease of the protein and
albumin concentrations in the blood and prerenal kidney failure. In addition,
there was a paraprotein, type IgG-kappa. The shock every time responded rapidly
to intravenous administration of fluid and was followed by a period of
substantial polyuria. The pattern was characteristic of systemic capillary leak
syndrome, a rare but frequently fatal disease characterized by episodes of
unexplained extravasation of plasma. The aetiology and pathogenesis are unknown.
Attacks are suppressed by supportive therapy (administration of fluids,
inotropics) and future attacks may be prevented by the intake of terbutaline and
theophylline. The systemic capillary leak syndrome should be considered in the
differential diagnosis of idiopathic and anaphylactic shock.
PMID- 10682652
TI - [Do medical schools still train doctors?].
AB - In practice, medical finals are not final and a supplementary training is
necessary before medicine may be practised independently. Social factors and an
ongoing evolution of medical science prompt reconsideration of the structure,
content and duration of the training of doctors and specialists. This was the
subject of a meeting of this Journal. One possibility of differentiation in the
basic training is an early subdivision into care physicians, clinical specialists
and health physicians. In the training of social medical officers one of the
factors to be taken into account is the influence of principals. For GP's,
postgraduate training is increasingly important because of social and other
developments. The training of non-surgical specialists can be made shorter since
a significant proportion of the time in the present training is devoted to areas
requiring special attention. The training of surgical specialists could be
shortened by introducing a training programme that is independent of the
procedure. Responsibility for the total care of the patient will be borne by the
specialists jointly.
PMID- 10682653
TI - [General practitioner: acrobat or drug store clerk?].
PMID- 10682654
TI - [Family doctor: acrobat or drugstore clerk?].
PMID- 10682655
TI - [Family doctor: acrobat or drugstore clerk?].
PMID- 10682657
TI - Hypermethylation of ribosomal DNA in human breast carcinoma.
AB - We examined the methylation status of the transcribed domain of ribosomal DNA
(rDNA) in 58 patients with breast cancer. The mean percent of methylation was
significantly higher in breast tumours than that of normal control samples (P <
0.0001). This increased rDNA methylation was associated with oestrogen receptor
non-expression (P < 0.0273) and with moderately or poorly differentiated tumours
as compared to well differentiated tumours (P < 0.0475). Our results suggest that
rDNA can be a useful marker for monitoring aberrant methylation during breast
tumour progression.
PMID- 10682656
TI - Oestrogen and growth factor cross-talk and endocrine insensitivity and acquired
resistance in breast cancer.
PMID- 10682658
TI - 17Beta-hydroxysteroid dehydrogenase type 1 and type 2 in human breast carcinoma:
a correlation to clinicopathological parameters.
AB - The expression of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) type 1 and
type 2 was examined immunohistochemically in 111 invasive ductal carcinomas, and
correlated with various clinicopathological parameters. This study investigates
local regulatory mechanisms of oestrogens in human breast carcinoma. 17Beta-HSD
type 1 was immunolocalized in carcinoma cells of 68 out of 111 invasive ductal
carcinoma cases (61.3%). 17Beta-HSD type 2 immunoreactivity was not detected in
all cases examined. A significant inverse correlation was observed between the
immunohistochemical expression of 17beta-HSD type 1 and histological grade of the
carcinoma (P < 0.02). There was a significant correlation between 17beta-HSD type
1 and oestrogen receptor (ER) labelling index (LI) (P < 0.05). In addition,
carcinoma cells expressing immunoreactive 17beta-HSD type 1 were frequently
positive for ER. 17Beta-HSD type 1 was also correlated with progesterone receptor
(PR) LI (P < 0.05). There was a significant inverse correlation between 17beta
HSD type 1 and Ki-67 LI (P < 0.0001). No significant correlations were detected
between 17beta-HSD type 1 and other clinicopathological parameters, including
patient age, menopausal status, stage, tumour size, lymph node status and
prognosis. This study suggests that 17beta-HSD type 1 plays an important role in
the regulation of in situ oestradiol production in hormone-dependent breast
carcinomas.
PMID- 10682659
TI - Idarubicinol myelotoxicity: a comparison of in vitro data with clinical outcome
in patients treated with high-dose idarubicin.
AB - We evaluated in vitro the toxicity of idarubicin and its active metabolite
idarubicinol on haematopoietic progenitors, using human umbilical cord blood and
peripheral blood progenitors to obtain dose-response curves. We treated 16
patients with poor prognosis lymphoma in a phase I-II trial of high-dose
idarubicin and melphalan and investigated if idarubicinol persisting in patients'
plasma at the time of transplantation (day 0), on day +1 and +2 could result in
an inhibition of infused progenitors. Colony inhibition was correlated with
pharmacokinetic data and with the time of patients' engraftment. Plasma samples
obtained before idarubicin treatment demonstrated a colony-stimulating effect,
increasing the cloning efficiency by 72%. The inhibitory activity on colony
forming unit granulocyte-macrophage (CFU-GM) of patients' plasma collected on the
day of transplantation was lower than expected from dose-response curves (21%
measured vs 70% expected). The time to patients' WBC and PLT recovery correlated
with the amount of CD34+ cells reinfused and, to a lesser extent, with the colony
inhibiting effect of patients' plasma. The correlation between idarubicinol
concentration and CFU-GM inhibition was not significant. These data suggest that
plasma drug concentration on the day of stem cell reinfusion may overestimate the
toxicity of residual anthracyclines to the transplanted cells.
PMID- 10682660
TI - A unified definition of clinical anthracycline resistance breast cancer.
AB - The purpose of the study was to determine the response rates (RR) and duration to
second- and third-line chemotherapy programmes in patients with anthracycline
resistant breast cancer, utilizing various definitions of anthracycline
resistance. This was a retrospective analysis performed on 1335 patients with
metastatic breast cancer who participated in consecutive clinical trials of first
line, anthracycline-containing combination chemotherapy (ACCC) at the University
of Texas MD Anderson Cancer Center between July 1973 and April 1980.
Anthracycline-resistant groups were identified using definitions of anthracycline
resistance found in the literature: progressive disease as best response to ACCC
(Group 1, n = 56 patients); progressive disease while receiving ACCC after an
intervening response to the drug (Group 2, n = 84); progressive disease within 6
months of last dose of ACCC (Group 3, n = 233); and progressive disease within 12
months of last dose of ACCC (Group 4, n = 272). Second- and third-line therapies
administered to these patients included methotrexate, doxorubicin, mitoxantrone,
bisantrene, vinblastine, vindesine, melphalan, mitomycin, cisplatin, etoposide
and others, but not taxanes. The distribution of patients' characteristics was
similar between the four groups, as was the use of second- and third-line
regimens. Response rate (RR) to second-line chemotherapy were 5% and 7.7% for
Group 1 and Group 2 respectively. In contrast, RR to second-line chemotherapy
were 21.6% and 15% for Group 3 and 4. The differences in response rate between
the combination of Groups 1 and 2 and Groups 3 or 4 were significant (P = 0.005
and P = 0.04 respectively). These results indicate that strictly defined
anthracycline resistance as defined in Groups 1 and 2 is associated with
resistance to many other cytotoxic drugs. The definitions used in Groups 3 and 4
include many patients with responsive tumours, and a more favourable prognosis.
PMID- 10682661
TI - Intron splice acceptor site polymorphism in the hMSH2 gene in sporadic and
familial colorectal cancer.
AB - A polymorphism in hMSH2 gene has been associated with an increased susceptibility
to develop colorectal cancer (CRC). Here we show that it is a genetic risk factor
for CRC in the Spanish population. However, its presence does not apparently
affect hMSH2 function.
PMID- 10682662
TI - The prevalence of BRCA1 mutations in Chinese patients with early onset breast
cancer and affected relatives.
AB - The purpose of this study was to determine the prevalence of BRCA1 mutations in
Chinese breast cancer patients in Singapore. BRCA1 analysis was conducted in
consecutive patients with breast cancer before the age of 40 years (76 women), or
whose relatives had breast or ovarian cancer (16 women). Ten patients had both
early onset breast cancer and affected relatives. Genomic DNA from peripheral
mononuclear blood cells was studied by using the protein transcription
translation assay (exon 11) and single-strand conformational polymorphism, with
subsequent DNA sequencing. All six disease-causing mutations occurred in women
under 40 years (8.6%) with three occurring in patients under 35 years (three out
of 22 patients, 13.6%). Mis-sense mutations of unknown significance were found in
three patients. Two of the ten women with affected relatives under 40 years had
BRCA1 mutations. The prevalence of BRCA1 mutations in Chinese patients with early
onset breast cancer is similar to that observed in Caucasian women. Most Chinese
patients with affected relatives were not carriers of BRCA1 mutations.
PMID- 10682663
TI - Multiple deleted regions on the long arm of chromosome 6 in astrocytic tumours.
AB - Chromosome 6 deletions are common in human neoplasms including gliomas. In order
to study the frequency and identify commonly deleted regions of chromosome 6 in
astrocytomas, 159 tumours (106 glioblastomas, 39 anaplastic astrocytomas and 14
astrocytomas malignancy grade II) were analysed using 31 microsatellite markers
that span the chromosome. Ninety-five per cent of cases with allelic losses had
losses affecting 6q. Allelic losses were infrequent in astrocytomas malignancy
grade II (14%) but more usual in anaplastic astrocytomas (38%) and glioblastomas
(37%). Evidence for clonal heterogeneity in the astrocytomas and anaplastic
astrocytomas was frequently observed (i.e. co-existence of subpopulations with
and without chromosome 6 deletions). Clonal heterogeneity was less common in
glioblastomas. Five commonly deleted regions were identified on 6q. These
observations suggest that a number of tumour suppressor genes are located on 6q
and that these genes may be involved in the progression of astrocytic tumours.
PMID- 10682664
TI - Analysis of the insertion/deletion polymorphism of the human angiotensin
converting enzyme (ACE) gene in patients with renal cancer.
AB - The angiotensin I-converting enzyme (ACE) contains an insertion/deletion (I/D)
polymorphism, with the DD genotype associated with benign renal diseases. The
distribution frequencies of the D and I alleles, and the DD, DI and II genotypes
were determined in DNA extracted from kidney tissues of 58 renal cancer patients.
The observed frequencies in patients who develop renal cancer was not
significantly different than the normal population.
PMID- 10682665
TI - Identification of a founder BRCA2 mutation in Sardinia.
AB - Sardinian population can be instrumental in defining the molecular basis of
cancer, using the identity-by-descent method. We selected seven Sardinian breast
cancer families originating from the northern-central part of the island with
multiple affected members in different generations. We genotyped 106 members of
the seven families and 20 control nuclear families with markers flanking BRCA2
locus at 13q12-q13. The detection of a common haplotype shared by four out of
seven families (60%) suggests the presence of a founder BRCA2 mutation. Direct
sequencing of BRCA2 coding exons of patients carrying the shared haplotype,
allowed the identification of a 'frame-shift' mutation at codon 2867 (8765delAG),
causing a premature termination-codon. This mutation was found in breast cancer
patients as well as one prostate and one bladder cancer patient with shared
haplotype. We then investigated the frequency of 8765delAG in the Sardinian
breast cancer population by analysing 270 paraffin-embedded normal tissue samples
from breast cancer patients. Five patients (1.7%) were found to be positive for
the 8765delAG mutation. Discovery of a founder mutation in Sardinia through the
identity-by-descent method demonstrates that this approach can be applied
successfully to find mutations either for breast cancer or for other types of
tumours.
PMID- 10682666
TI - Thymidilate synthase and p53 primary tumour expression as predictive factors for
advanced colorectal cancer patients.
AB - The purpose of this work was to analyse the ability of p53 and thymidilate
synthase (TS) primary tumour expression to retrospectively predict clinical
response to chemotherapy and long-term prognosis in patients with advanced
colorectal cancers homogeneously treated by methotrexate (MTX)-modulated-5
fluorouracil (5-FU-FA). A total of 108 advanced colorectal cancer patients
entered the present retrospective study. Immunohistochemical p53 (pAb 1801 mAb)
and TS (TS106 mAb) expression on formalin-fixed paraffin-embedded primary tumour
specimens was related to probability of clinical response to chemotherapy, time
to progression and overall survival. p53 was expressed in 53/108 (49%) tumours,
while 54/108 (50%) showed TS immunostaining. No relationship was demonstrated
between p53 positivity and clinical response to chemotherapy (objective response
(OR): 20% vs 23%, in p53+ and p53- cases respectively) or overall survival.
Percent of OR was significantly higher in TS-negative with respect to TS-positive
tumours (30% vs 15% respectively; P < 0.04); simultaneous analysis of TS and p53
indicated 7% OR for p53-positive/TS-positive tumours vs 46% for p53-positive/TS
negative tumours (P < 0.03). Logistic regression analysis confirmed a significant
association between TS tumour status and clinical response to chemotherapy
(hazard ratio (HR): 2.91; 95% confidence interval (CI) 8.34-1.01; two-sided P <
0.05). A multivariate analysis of overall survival showed that only a small
number of metastatic sites was statistically relevant (HR 1.89; 95% CI 2.85-1.26;
two-sided P < 0.03). Our study suggests that immunohistochemical expression of
p53 and TS could assist the clinician in predicting response of colorectal cancer
patients to modulated MTX-5-FU therapy.
PMID- 10682667
TI - Lobular carcinoma in situ of the breast is not caused by constitutional mutations
in the E-cadherin gene.
AB - Lobular carcinoma in situ (LCIS) is an unusual histological pattern of non
invasive neoplastic disease of the breast occurring predominantly in women aged
between 40 and 50 years. LCIS is frequently multicentric and bilateral, and there
is evidence that it is associated with an elevated familial risk of breast
cancer. Although women with LCIS suffer an increased risk of invasive breast
disease, this risk is moderate suggesting that LCIS may result from mutation of a
gene or genes conferring a high risk of LCIS, but a lower risk of invasive breast
cancer. The high frequency of somatic mutations in E-cadherin in LCIS, coupled
with recent reports that germline mutations in this gene can predispose to
diffuse gastric cancer, raised the possibility that constitutional E-cadherin
mutations may confer susceptibility to LCIS. In order to explore this possibility
we have examined a series of 65 LCIS patients for germline E-cadherin mutations.
Four polymorphisms were detected but no pathogenic mutations were identified. The
results indicate that E-cadherin is unlikely to act as a susceptibility gene for
LCIS.
PMID- 10682668
TI - Loss of DCC gene expression during ovarian tumorigenesis: relation to tumour
differentiation and progression.
AB - To clarify the possible role of DCC gene alteration in ovarian neoplasias, we
immunohistochemically investigated 124 carcinomas, as well as 55 cystadenomas and
41 low malignant potential (LMP) tumours and compared the results with those for
p53 protein expression, clinicopathological factors and survival. A combination
of the reverse transcription polymerase chain reaction (RT-PCR) and Southern blot
hybridization (SBH) for DCC mRNA levels was also carried out on 26 malignant,
five LMP, eight benign and seven normal ovarian samples. Significantly decreased
levels of overall DCC values in carcinomas compared with benign and LMP lesions
were revealed by both immunohistochemical and RT-PCR/SBH assays. Similar findings
were also noted when subdivision was into serous and mucinous categories. In
carcinomas, reduction or loss of DCC expression was significantly related to the
serous phenotype (serous vs non-serous, P < 0.0001), a high histological grade
(grade 1 vs 2 or 3, P < 0.02) and a more advanced stage (FIGO stage I vs
II/III/IV, P = 0.0083), while no association was noted with survival. Although
p53 immunopositivity demonstrated significant stepwise increase from benign
through to malignant lesions, there was no clear association with DCC score
values. The results indicated that impaired DCC expression may play an important
role in ovarian tumorigenesis. In ovarian carcinomas, the altered expression is
closely linked with tumour differentiation and progression.
PMID- 10682669
TI - Spontaneous apoptosis in ovarian carcinomas: a positive association with p53 gene
mutation is dependent on growth fraction.
AB - Changes in cell survival contribute to tumour development, influence tumour
biology and its response to chemotherapy. p53 gene alterations should negatively
affect apoptosis by impaired p53-dependent apoptotic response. We looked for
associations between spontaneous apoptosis, p53 gene mutation, p53 protein
accumulation, growth fraction, bcl-2 expression and histological parameters in 64
ovarian, four tubal and three peritoneal carcinomas. Apoptotic cells were
detected with the TUNEL method. p53 gene variants were detected by the single
strand conformation polymorphism and were sequenced directly. P53, Ki-67 and bcl
2 protein expressions were detected immunohistochemically. A weighed multiple
logistic regression model was applied. Apoptotic index (AI) ranged 0.02-0.18
(mean 0.11); proliferation index (PI) ranged 3-90% (mean 54%). p53 gene mutations
were present in 51, p53 protein accumulation in 46, and diffuse bcl-2 expression
in 29 of 71 tumours. The AI was positively associated with the presence of p53
gene mutation (P = 0.011). However, the PI included into the analysis did
positively influence the AI (P = 0.02) and diminished the association with p53
gene mutation (P = 0.082). The AI was negatively associated with good
histological differentiation (P = 0.0006), the serous tumour type (P = 0.002),
and diffuse bcl-2 expression (P = 0.025). Strong bcl-2 expression was associated
with endometrioid tumour type (P = 0.002). FIGO stage and p53 protein
accumulation were the only parameters that influenced overall survival time.
Thus, our results suggest that histological tumour type and grade are major
determinants of spontaneous apoptosis in ovarian carcinomas; p53 alterations do
not adversely but rather positively affect spontaneous apoptosis by increasing
growth fraction. This, in turn, suggests p53-independency of spontaneous
apoptosis in ovarian carcinomas.
PMID- 10682670
TI - Tumour prothymosin alpha content, a potential prognostic marker for primary
breast cancer.
AB - In a previous report we suggested that the estimation of prothymosin alpha (PTA)
levels in primary breast tumours might be used to identify breast cancer patients
at high risk for distant metastasis (Dominguez F et al (1993) Eur J Cancer 29A:
893-897). Here the role of tumour PTA levels as predictor was investigated with
respect to both disease-free survival (DFS) and survival. Tumours were obtained
from a series of 210 consecutive female patients with ductal carcinoma who
underwent surgery at the Hospital Xeral de Galicia (Santiago de Compostela,
Spain). Characteristics including PTA tumour levels, number of positive axillary
nodes, patient's age at surgery and tumour histological grade were significantly
associated with DFS and survival, as determined by univariate analysis. Patients
with tumours with low or moderate PTA levels demonstrated a statistically
decreased rate of tumour recurrence and a statistically significant increased
overall survival in comparison with those whose tumours had high PTA levels.
Patient's relative risk of dying was 2.1 times greater for tumours with high PTA
levels than for those tumours with low or moderate PTA levels. In conclusion,
these data support the hypothesis that tumour high PTA levels is associated with
a worse outcome.
PMID- 10682671
TI - Angiogenic switch occurs late in squamous cell carcinomas of human skin.
AB - Angiogenesis is a crucial event in carcinogenesis and its onset has been
associated with premalignant tumour stages. In order to elucidate the
significance of angiogenesis in different stages of epithelial skin tumours, we
analysed the vessel density in ten normal skin samples, 14 actinic keratosis
(AK), 12 hypertrophic AKs, and in nine early- and 16 late-stage squamous cell
carcinomas (SCCs). Mean vascular density was quantitated by counting the number
of CD 31-immunostained blood vessels and by morphometric assessment of stained
vessel area by computer-assisted image analysis. The results from both methods
were well correlated. Mean vascular density was similar in normal dermis and in
AK, and only slightly elevated in hypertrophic AKs and early SCC stages (tumour
thickness < 2 mm). Only late-stage SCCs infiltrating the subcutis exhibited a
significant increase in vascularization. Vessel density was independent of tumour
localization, degree of proliferation and inflammatory cell infiltration.
Furthermore, tumour vascularization was not correlated with the expression of
vascular endothelial growth factor, a major angiogenic factor, as revealed by in
situ hybridization and immunohistochemistry. The restriction of enhanced
vascularization to increased tumour thickness may be a major reason for the
rather low metastatic spread of cutaneous SCCs.
PMID- 10682672
TI - Telomere length and telomerase activity in malignant lymphomas at diagnosis and
relapse.
AB - Telomere length maintenance, in the vast majority of cases executed by
telomerase, is a prerequisite for long-term proliferation. Most malignant
tumours, including lymphomas, are telomerase-positive and this activity is a
potential target for future therapeutic interventions since inhibition of
telomerase has been shown to result in telomere shortening and cell death in
vitro. One prerequisite for the suitability of anti-telomerase drugs in treating
cancer is that tumours exhibit shortened telomeres compared to telomerase
positive stem cells. A scenario is envisioned where the tumour burden is reduced
using conventional therapy whereafter remaining tumour cells are treated with
telomerase inhibitors. In evaluating the realism of such an approach it is
essential to know the effects on telomere status by traditional therapeutic
regimens. We have studied the telomere lengths in 47 diagnostic lymphomas and a
significant telomere shortening was observed compared to benign lymphoid tissues.
In addition, telomere length and telomerase activity were studied in consecutive
samples from patients with relapsing non-Hodgkin's lymphomas. Shortened,
unchanged and elongated telomere lengths were observed in the relapse samples.
The telomere length alterations found in the relapsing lymphomas appeared to be
independent of telomerase and rather represented clonal selection random at the
telomere length level. These data indicate that anti-telomerase therapy would be
suitable in only a fraction of malignant lymphomas.
PMID- 10682673
TI - Early evaluation of tumour metabolic response using [18F]fluorodeoxyglucose and
positron emission tomography: a pilot study following the phase II chemotherapy
schedule for temozolomide in recurrent high-grade gliomas.
AB - Quantitation of metabolic changes in tumours may provide an objective measure of
clinical and subclinical response to anticancer therapy. This pilot study
assesses the value of quantitation of metabolic rate of glucose (MRGlu) measured
in mmol min(-1) ml(-1) to assess early subclinical response to therapy in a
relatively non-responsive tumour. Nine patients receiving the CRC Phase II study
schedule of temozolomide were assessed with [18F]fluorodeoxyglucose ([18F]FDG)
dynamic positron emission tomography (PET) scans prior to and 14 days after
treatment with temozolomide given as 750-1000 mg m(-2) over 5 days every 28 days.
Tumour MRGlu was calculated and compared with objective response at 8 weeks.
Pretreatment MRGlu was higher in responders than non-responders. The responding
patient group had a greater than 25% reduction in MRGlu in regions of high focal
tumour uptake (HFU). Whole tumour changes in MRGlu did not correlate with
response. Percentage change in HFU standardized uptake value (SUV) did
discriminate the responding from the non-responding patients, but not as well as
with MRGlu. Large differences also occurred in the normal brain SUV following
treatment. Thus, MRGlu appeared to be a more sensitive discriminator of response
than the simplified static SUV analysis. Changes in MRGlu may reflect the degree
of cell kill following chemotherapy and so may provide an objective, quantitative
subclinical measure of response to therapy.
PMID- 10682674
TI - Diagnosis of persistent ovarian carcinoma with three-step immunoscintigraphy.
AB - The diagnosis of recurrent ovarian carcinoma is usually determined at surgical re
exploration since the main non-invasive diagnostic tests have low accuracy. It
would be desirable to have a high accuracy non-invasive diagnostic procedure.
With this aim, we have assessed the utility of three-step immunoscintigraphy.
Thirty patients were intravenously injected with biotinylated monoclonal
antibodies MOv18 and B72.3, followed by avidin-streptavidin injection and finally
by 111In-biotin. Tumour recurrences were imaged 2 h post radioactivity injection.
All patients underwent surgical re-exploration 3-4 days after immunoscintigraphy;
the presence of tumour in the area of immunoscintigraphic uptake was evaluated in
the biopsied material. Twenty-one patients studied were true-positive, five were
true-negative, four were false-positive and none was false-negative. The
diagnostic accuracy, positive predictive value and negative predictive value were
87%, 84% and 100% respectively. If these findings are confirmed in a larger
number of patients, we expect immunoscintigraphy to be introduced as a cost
effective procedure in the follow-up of patients who have received surgery for
ovarian carcinoma, since it promises to reliably identify patients who do not
require surgical re-exploration, and guide biopsies when they are indicated.
PMID- 10682675
TI - IL-6 production in ovarian carcinoma is associated with histiotype and biological
characteristics of the tumour and influences local immunity.
AB - The presence of interleukin (IL)-6 in peritoneal carcinomatous fluid (PCF) and
its effect on immune cells composition in PCF in patients with advanced ovarian
carcinoma was studied. In 21 out of 30 ovarian carcinoma patients, PCF IL-6
levels were found to exceed those seen in PCFs of patients with gastrointestinal
cancer. IL-6 activity was higher in serous/mucinous than in endometrioid and
undifferentiated ovarian carcinoma PCF (P = 0.05). Ovarian carcinoma PCF IL-6
activities were correlated with serum C-reactive protein levels (r = 0.65, P =
0.0000, n = 25). Ovarian carcinoma PCF leucocyte profile differed from that in
blood with respect to: (i) lower percentage of NK and CD8+ and (ii) higher
percentage of B and CD45RO+, CD14+ and HLA-DR+ cells. The proportions of CD45RO+
in blood were correlated with IL-6 levels in PCF. Corresponding to PCF ovarian
carcinoma tumours were stained for the presence of Ki-67 antigen and p53. The
highest proportions of Ki-67+ cells and cells showing accumulation of p53 were
seen in undifferentiated tumours. A low grade of p53 staining was seen in tumours
associated with high IL-6 levels in PCF. It was evident that IL-6 production (i)
depended on the histiotype of the tumour, (ii) influenced the local immune system
in favour of accumulation of B, and T memory cells, and (iii) was higher in
patients lacking p53 accumulation.
PMID- 10682676
TI - Mechanistic aspects of the cytotoxic activity of glufosfamide, a new tumour
therapeutic agent.
AB - Beta-D-glucosyl-ifosfamide mustard (D 19575, glc-IPM, INN = glufosfamide) is a
new agent for cancer chemotherapy. Its mode of action, which is only partly
understood, was investigated at the DNA level. In the breast carcinoma cell line
MCF7 glufosfamide inhibited both the synthesis of DNA and protein in a dose
dependent manner, as shown by the decreased incorporation of [3H-methyl]
thymidine into DNA and [14C]-methionine into protein of these cells. Treatment of
MCF7 cells with 50 microM glufosfamide was sufficient to trigger poly(ADP-ribose)
polymerase (PARP) activation, as revealed by immunofluorescence analysis. Both
CHO-9 cells, which are O6-methylguanine-DNA methyltransferase (MGMT)-deficient,
and an isogenic derivative, which has a high level of MGMT, showed the same
cytotoxic response to beta-D-glc-IPM, indicating that the O6 position of guanine
is not the critical target for cytotoxicity. By contrast, a sharp decrease in
survival of cross-link repair deficient CL-V5 B cells was observed already at
concentrations of 0.1 mM beta-D-glc-IPM, whereas the wild-type V79 cells showed a
90% reduction in survival only after treatment with 0.5 mM of this compound. The
therapeutically inactive beta-L-enantiomer of glufosfamide also showed genotoxic
effects in the same assays but at much higher doses. This was probably due to
small amounts of ifosfamide mustard formed under the conditions of incubation.
The results indicate that the DNA crosslinks are the most critical cytotoxic
lesions induced by beta-D-glc-IPM.
PMID- 10682677
TI - Vascular endothelial growth factor expression is independent of hypoxia in human
malignant glioma spheroids and tumours.
AB - We recently showed that severe hypoxia was not universally present adjacent to
necrosis in human glioma xenografts and spheroids established from the M059K,
M006, M006X, M006XLo and M010b cell lines. Using these glioma models, we wished
to test whether oxygen serves as a regulator of cellular VEGF expression in situ.
In situ hybridization (ISH) and immunohistochemistry (IHC) were used to detect
vascular endothelial growth factor (VEGF) mRNA and protein expression in sections
of glioma xenografts and spheroids in which hypoxic regions and regions with well
oxygenated necrosis were identified on contiguous sections by use of the hypoxia
specific marker, 3H-misonidazole. Independent validation of the presence of
radiobiologically hypoxic cells in M006 xenografts was undertaken using the comet
assay. Northern blotting analyses of monolayer cells demonstrated significant up
regulation of VEGF mRNA in the M006X line at oxygen concentrations of 6% and
below. ISH analysis of VEGF mRNA showed unexpectedly strong staining for VEGF
mRNA across the entire viable rim of M006X and M006XLo glioma spheroids.
Similarly, in virtually all xenograft tumours of the M059K, M006 and M010b lines,
VEGF ISH showed similar staining across all regions of healthy cells up to the
border of necrosis. Only in one M006X tumour was there a suggestion of increased
VEGF expression in cells adjacent to necrosis. IHC for VEGF showed good
concordance with the ISH results. IHC analysis of the VEGF receptor flt-1 showed
strong tumour cell staining in M006XLo glioma cells. In human glioma spheroids
and xenograft tumours, regions of severe hypoxia do not correspond to areas of up
regulated VEGF expression; in fact, VEGF expression is quite uniform.
Furthermore, this and our previous study demonstrate that levels of VEGF
expression vary among sublines (M006, M006X and M006XLo) derived from a single
human glioma specimen.
PMID- 10682678
TI - p53-dependent G2 arrest associated with a decrease in cyclins A2 and B1 levels in
a human carcinoma cell line.
AB - In vivo transfer of wild-type (wt) p53 gene via a recombinant adenovirus has been
proposed to induce apoptosis and increase radiosensitivity in several human
carcinoma models. In the context of combining p53 gene transfer and irradiation,
we investigated the consequences of adenoviral-mediated wtp53 gene transfer on
the cell cycle and radiosensitivity of a human head and neck squamous cell
carcinoma line (SCC97) with a p53 mutated phenotype. We showed that ectopic
expression of wtp53 in SCC97 cells resulted in a prolonged G1 arrest, associated
with an increased expression of the cyclin-dependent kinase inhibitor WAF1/p21
target gene. A transient arrest in G2 but not in G1 was observed after
irradiation. This G2 arrest was permanent when exponentially growing cells were
transduced by Ad5CMV-p53 (RPR/INGN201) immediately after irradiation with 5 or 10
Gy. Moreover, levels of cyclins A2 and B1, which are known to regulate the G2/M
transition, dramatically decreased as cells arrived in G2, whereas maximal levels
of expression were observed in the absence of wtp53. In conclusion, adenoviral
mediated transfer of wtp53 in irradiated SCC97 cells, which are mutated for p53,
appeared to increase WAF1/p21 expression and decrease levels of the mitotic
cyclins A2 and B1. These observations suggest that the G2 arrest resulted from a
p53-dependent premature inactivation of the mitosis promoting factor.
PMID- 10682679
TI - NADPH:cytochrome c (P450) reductase activates tirapazamine (SR4233) to restore
hypoxic and oxic cytotoxicity in an aerobic resistant derivative of the A549 lung
cancer cell line.
AB - Tirapazamine (TPZ, SR4233, WIN 59075) is a bioreductive drug that is activated in
regions of low oxygen tension to a cytotoxic radical intermediate. This labile
metabolite shows high selective toxicity towards hypoxic cells, such as those
found in solid tumours. Under aerobic conditions, redox cycling occurs with
subsequent generation of superoxide radicals, which are also cytotoxic.
NADPH:cytochrome c (P450) reductase (P450R) is a one-electron reducing enzyme
that efficiently activates TPZ. Recently a derivative of the A549 non-small cell
lung cancer cell line (A549c50) was generated that showed substantially reduced
P450R activity compared to its parental line (Elwell et al (1997) Biochem
Pharmacol 54: 249-257). Here, it is demonstrated that the A549c50 cells are
markedly more resistant to TPZ under both aerobic and hypoxic conditions. In
addition, these cells have a dramatically impaired ability to metabolize TPZ to
its two-electron reduction product, SR4317, under hypoxic conditions when
compared to wild-type cells. P450R activity in the A549c50 cells was reintroduced
to similar levels as that seen in the parental A549 cells by transfection of the
full-length cDNA for human P450R. These P450R over-expressing cells exhibit
restored sensitivity to TPZ under both aerobic and hypoxic conditions, comparable
to that found in the original parental A549 cells. Further, the ability of the
transfected cells to metabolize TPZ to SR4317 under hypoxic conditions is also
shown to be restored. This provides further evidence that P450R can play an
important role in the activation, metabolism and toxicity of this lead
bioreductive drug.
PMID- 10682681
TI - ERBB-2 overexpression confers PI 3' kinase-dependent invasion capacity on human
mammary epithelial cells.
AB - Amplification and overexpression of ERBB-2 in human breast cancer is thought to
play a significant role in the progression of the disease; however, its precise
role in the aetiology of altered phenotypes associated with human breast cancer
is unknown. We have previously shown that exogenous overexpression of ERBB-2
conferred growth factor independence on human mammary epithelial cells. In this
study, we show that ERBB-2 overexpression also causes the cells to acquire other
characteristics exhibited by human breast cancer cells, such as anchorage
independent growth and invasion capabilities. ERBB-2-induced invasion is
dependent on fibronectin and correlates with the down-regulation of cell surface
alpha4 integrin. In addition ERBB-2 co-immunoprecipitates with focal adhesion
kinase (FAK) in these cells. We have also shown, by use of exogenously expressed
PTEN and by treatment with the PI3'-kinase inhibitor LY294002, that ERBB-2
induced invasion is dependent on the PI3'-kinase pathway; however, PTEN does not
dephosphorylate FAK in these cells.
PMID- 10682680
TI - Collagenolytic and gelatinolytic matrix metalloproteinases and their inhibitors
in basal cell carcinoma of skin: comparison with normal skin.
AB - Tissue from 54 histologically-identified basal cell carcinomas of the skin was
obtained at surgery and assayed using a combination of functional and
immunochemical procedures for matrix metalloproteinases (MMPs) with
collagenolytic activity and for MMPs with gelatinolytic activity. Collagenolytic
enzymes included MMP-1 (interstitial collagenase), MMP-8 (neutrophil collagenase)
and MMP-13 (collagenase-3). Gelatinolytic enzymes included MMP-2 (72-kDa
gelatinase A/type IV collagenase) and MMP-9 (92-kDa gelatinase B/type IV
collagenase). Inhibitors of MMP activity including tissue inhibitor of
metalloproteinases-1 and -2 (TIMP-1 and TIMP-2) were also assessed. All three
collagenases and both gelatinases were detected immunochemically. MMP-1 appeared
to be responsible for most of the functional collagenolytic activity while
gelatinolytic activity reflected both MMP-2 and MMP-9. MMP inhibitor activity was
also present, and appeared, based on immunochemical procedures, to reflect the
presence of TIMP-1 but not TIMP-2. As a group, tumours identified as having
aggressive-growth histologic patterns were not distinguishable from basal cell
carcinomas with less aggressive-growth histologic patterns. In normal skin, the
same MMPs were detected by immunochemical means. However, only low to
undetectable levels of collagenolytic and gelatinolytic activities were present.
In contrast, MMP inhibitor activity was comparable to that seen in tumour tissue.
In previous studies we have shown that exposure of normal skin to epidermal
growth factor in organ culture induces MMP up-regulation and activation. This
treatment concomitantly induces stromal invasion by the epithelium (Varani et al
(1995) Am J Pathol 146: 210-217; Zeigler et al (1996b) Invasion Metastasis 16: 11
18). Taken together with these previous data, the present findings allow us to
conclude that the same profile of MMP/MMP inhibitors that is associated with
stromal invasion in the organ culture model is expressed endogenously in basal
cell carcinomas of skin.
PMID- 10682682
TI - The role of p16-cyclin d/CDK-pRb pathway in the tumorigenesis of endometrioid
type endometrial carcinoma.
AB - We analysed p16 gene alteration and p16, cyclin-dependent kinase 4 (CDK4), CDK6,
cyclin D1, cyclin D2, cyclin D3 and retinoblastoma protein (pRb) expression in
ten normal endometriums (PE), 18 endometrial hyperplasias (EH) and 35 endometrial
cancers (EC). Two of ten PE (20%), nine of 18 EH (50.0%) and 29 of 35 EC (82.9%)
exhibited p16 nuclear staining. p16 expression was significantly higher in EC
than EH (P = 0.0119). In the six p16 (-) EC, one was considered to have reduced
gene dosage consistent with possible homozygous deletion of the CDKN2 gene and
three had methylation in 5'CpG island in the promoter region of the p16 gene,
whereas none showed such reduced gene dosage and four had methylation in the nine
p16 (-) EH. Strong CDK4 staining was observed in 12 of 35 EC (34.3%) and one of
18 EH (5.6%). The strong expression of CDK4 was higher in EC than in EH (P =
0.0399). The expression of CDK4 was higher in EH than PE (P = 0.0054). The
abnormalities of p16-cyclin D/CDK-pRb pathway were detected in 18 of 35 EC
(51.4%). In conclusion, the expression of p16 and CDK4 may be an early event in
the neoplastic transformation of endometrial cancer.
PMID- 10682683
TI - Interaction of the PA2G4 (EBP1) protein with ErbB-3 and regulation of this
binding by heregulin.
AB - The processes by which ErbB-3, an inactive tyrosine kinase, exerts its biological
effects are poorly understood. Using the yeast two-hybrid system, we have
isolated an ErbB-3 binding protein (Ebp1) that interacts with the juxtamembrane
domain of ErbB-3. This protein is identical to that predicted to be encoded for
by the human PA2G4 gene. Ebp1 is the human homologue of a previously identified
cell cycle-regulated mouse protein p38-2G4. Two transcripts of ebp1 mRNA (1.7 and
2.2 kb) were detected in several normal human organs. The interaction of Ebp1
with ErbB-3 was examined in vitro and in vivo. The first 15 amino acids of the
juxtamembrane domain of ErbB-3 were essential for Ebp1 binding in vitro.
Treatment of AU565 cells with the ErbB-3 ligand heregulin resulted in
dissociation of Ebp1 from ErbB-3. Ebp1 translocated from the cytoplasm into the
nucleus following heregulin stimulation. These findings suggest that Ebp1 may be
a downstream member of an ErbB-3-regulated signal transduction pathway.
PMID- 10682685
TI - Detection of antibodies to human herpesvirus 8 in Italian children: evidence for
horizontal transmission.
AB - Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma associated
herpesvirus (KSHV), has been shown to be the causative agent for Kaposi's sarcoma
(KS) and to be more prevalent in populations or risk groups at increased risk for
KS. HHV-8 infection is rare in children from the US and the UK, but has been
reported in African children. In this study we examine HHV-8 infection in
children from Italy, a country with an elevated prevalence of HHV-8 in adults and
high socio-economic conditions.
PMID- 10682684
TI - Lack of evidence for MHC-unrestricted (atypical) recognition of mucin by mucinous
pancreatic tumour-reactive T-cells.
AB - Cytotoxic T-cells generated against heterologous, mucinous pancreatic tumour
cells were shown to recognize mucin in a major histocombatibility complex (MHC)
unrestricted fashion. In contrast, the present study demonstrates a typical
allogeneic response of heterologous cytotoxic T-cells established against mucin
expressing pancreatic tumour cells. Heterologous cytotoxic T cells lysed targets
that were used as stimulators and other targets that shared human leucocyte
antigen (HLA) with the stimulator. These cytotoxic T-cells lysed mucin-expressing
stimulator cells but not autologous tumour cells in spite of expressing mucin on
their surface. Likewise, tumour-infiltrating CD4+ T-cells proliferated against
its own tumour cell target, while such T-cells did not respond to heterologous,
mucin-expressing pancreatic tumour cells. Culturing heterologous tumour-specific
cytotoxic T-cells with purified pancreatic tumour cell-mucin rendered them
unresponsive to their target cells. Furthermore, purified mucin did not produce a
mucin-specific response in mucinous pancreatic tumour patients' primary T-cells
even in the presence of antigen-presenting cells. Our study finds no evidence for
MHC-unrestricted recognition of mucin by pancreatic cancer patients' T-cells.
PMID- 10682686
TI - Evidence of a founder BRCA1 mutation in Scotland.
AB - BRCA1 mutations have been identified in breast and ovarian cancer families from
diverse ethnic backgrounds. We studied 17 different families with the BRCA1
2800delAA mutation; seven were ascertained in Scotland (Dundee, Edinburgh,
Glasgow, St Andrews), five in Canada (Toronto, Victoria) and five in the United
States (Chicago, Philadelphia, Seattle). Overall there was a clear preponderance
of Scottish ancestry. Genotype analysis performed on key members from 17 families
was consistent with a common haplotype, strongly suggesting a single ancestral
origin. A possible link was established between two families by tracing their
genealogies through the records of the Registrar General for Scotland. This is
the first example of a BRCA1 mutation likely to be derived from a common founder
in Scotland. Further studies will be necessary to estimate more accurately the
population frequency of the BRCA1 2800delAA mutation among unselected cases of
breast and ovarian cancer in Scotland and the UK.
PMID- 10682687
TI - Reducing DCO registrations through electronic matching of cancer registry data
and routine hospital data.
AB - The Thames Cancer Registry (TCR) has registered a high proportion of tumours from
death certificate information only (DCO) registrations. This paper describes the
results of a study set up to establish whether this proportion could be reduced
by linking cancer registrations with routine hospital data from the Hospital
Episodes Statistics (HES) data set using computerized matching. A total of 67752
registrations were identified from the TCR. Matches were found in the HES data
set for 66%. The proportion of cases retrieved for each tumour site was: 72% for
colorectal cancer; 62% for cancer of the lung, trachea or bronchus; and 65% for
female breast cancer. For all three tumour sites the proportion of matches found
for patients registered from hospital case notes was higher than the proportion
found for patients registered as DCOs (P < 0.0001 for all three tumour sites).
Among matched DCO cases, 58% had at least one procedure recorded. DCO rates might
be reduced by as much as 43% (from 17% of total registrations to less than 10%)
for the three most common cancers if the method of electronic matching outlined
here was used. Younger age groups, prognosis of tumour site and residence in
North Thames region were all positively associated with successful matching (P <
0.0001 in all three cases). Many matched DCO cases were found to have had more
than one admission for cancer. Among ordinary in-patient admissions, admissions
to patients ratios of 1.5, 1.4 and 1.9 were found for colorectal, lung and breast
cancers respectively. Of 5190 matched DCOs a procedure was recorded for 3013
(58%). HES data offer a useful aid to follow-up of case notes on patients
identified to the registry by death certificates. Doubts about the completeness
and accuracy of HES data mean case notes must remain the 'gold standard'.
PMID- 10682689
TI - Breast cancer among former college athletes compared to non-athletes: a 15-year
follow-up.
AB - A growing body of evidence indicates that physical activity is protective against
breast cancer. In 1996-97, we conducted a 15-year follow-up of 5398 college
alumnae comprised of former college athletes with their non-athletic classmates.
Participants completed a detailed mailed questionnaire on their health history
from 1981-82 to the present. Excluding women who had died and non-deliverable
questionnaires, 84.7% (n = 3940) of the participants in our earlier study
responded to the questionnaire; the response rate for former athletes was 86.6%
(n = 1945), for non-athletes, 83.0% (n = 1995). Results confirmed our earlier
findings. Based on self-reports, former college athletes had a significantly
lower risk of breast cancer than the non-athletes. The OR for the 15-year
incidence of breast cancer is 0.605 with 95% confidence interval (CI) (0.438
0.835); the 15-year incident breast cancers were 64 among the athletes and 111
among the non-athletes. Among women under 45 the protective effect of physical
activity on the risk of breast cancer is considerably greater; odds ratio (OR) =
0.164, 95% CI (0.042-0.636). Athletic activity during the college and pre-college
years is protective against breast cancer throughout the life span, and more
markedly among women under 45. These results confirm our earlier findings and the
findings of other investigators.
PMID- 10682688
TI - Sexual behaviour, STDs and risks for prostate cancer.
AB - A population-based case-control study was carried out among 981 men (479 black,
502 white) with pathologically confirmed prostate cancer and 1315 controls (594
black, 721 white). In-person interviews elicited information on sexual behaviour
and other potential risk factors for prostate cancer. Blood was drawn for
serologic studies in a subset of the cases (n = 276) and controls (n = 295).
Prostate cancer risk was increased among men who reported a history of gonorrhoea
or syphilis (odds ratio (OR) = 1.6; 95% confidence internal (CI) 1.2-2.1) or
showed serological evidence of syphilis (MHA-TP) (OR = 1.8; 95% CI 1.0-3.5).
Patterns of risk for gonorrhoea and syphilis were similar for blacks (OR = 1.7;
95% CI 1.2-2.2) and whites (OR = 1.6; 95% CI 0.8-3.2). Risks increased with
increasing occurrences of gonorrhoea, rising to OR = 3.3 (95% CI 1.4-7.8) among
subjects with three or more events (Ptrend = 0.0005). Frequent sexual encounters
with prostitutes and failure to use condoms were also associated with increased
risk. Syphilis, gonorrhoea, sex with prostitutes and unprotected sexual
intercourse may be indicators of contact with a sexually transmissible factor
that increases the risk of prostate cancer.
PMID- 10682690
TI - Adding free to total prostate-specific antigen levels in trials of prostate
cancer screening.
AB - We used a nested case-control design on data from men in four prospective studies
(from the UK, Maryland in the USA, and two from Finland) with available stored
serum samples to determine whether there was an advantage in measuring both free
prostate-specific antigen (PSA) and total PSA as a potential screening test for
prostate cancer. Of these men, 247 were verified through national vital
statistics offices as having died of prostate cancer, or having developed the
disease, and 953 men who did not develop prostate cancer (controls) were
selected, matched to cases for age, study centre and sample storage duration.
Fixing the false-positive rate at 1%, the prostate cancer detection rate
(sensitivity) over the 3 years following serum collection (based on 14 cancers)
increased from an estimated 95% using total PSA to 97% using free and bound PSA
(that is, bound to alpha-antichymotrypsin which together with the free form is
total PSA). Over a 6-year period (based on 41 cancers) a similar difference
occurred (52% and 56% detection rates respectively). We conclude that there is no
material advantage in adding free to total PSA in prostate cancer screening
trials.
PMID- 10682691
TI - Fertility in Norwegian testicular cancer patients.
AB - The intention was to explore the relationship between fertility and testicular
cancer, including the possibly treatment-induced changes over time in the post
diagnostic fertility. Data are from the Norwegian Cancer Registry, The Norwegian
Population Register and the Population Censuses. By estimating Poisson regression
models, birth rates among testicular cancer patients were compared with those of
other men who had the same age, parity and duration since previous birth. Poisson
regression models were also estimated to check whether men's parity has an effect
on the cancer incidence. Fertility rates among testicular cancer patients born
after 1935 and treated before 1991 decreased by roughly 30% when compared with
the normal population. The introduction of cisplatin chemotherapy and of nerve
sparing RPLND in the 1980s seems to have enabled more patients with non-seminoma
to father a child after treatment, or at least shortened the time to conception.
Moreover, the risk of being diagnosed with seminoma is reduced with increasing
parity. This suggests that the relatively low fertility after diagnosis may be
partly due to the continuing inherent influence of a sub- or infecundity that
also had a bearing on the development of the disease.
PMID- 10682692
TI - Delay in presentation of symptomatic referrals to a breast clinic: patient and
system factors.
AB - We attempted to identify factors associated with delay in presentation and
assessment of women with breast symptoms who attended a London breast clinic. A
total of 692 consecutive symptomatic referrals, aged 40-75 years, were studied.
Patient delay, assessed prior to diagnosis, was defined as time elapsing between
symptom discovery and first presentation to a medical provider. This was studied
in relation to: reasons for delaying, beliefs and attitudes, socio-demographic
and clinical variables, psychiatric morbidity and subsequent diagnosis. Thirty
five per cent of the cohort delayed presentation 4 weeks or more (median 13
days). The most common reason given was that they thought their symptom was not
serious (odds ratio (OR) = 5.32, 95% confidence interval (CI) 3.6-8.0). Others
thought their symptom would go away (OR = 3.73, 95% CI 2.2-6.4) or delayed
because they were scared (OR = 4.61, 95% CI 2.1-10.0). Delay was associated with
psychiatric morbidity but not age. Patients who turned out to have cancer tended
to delay less (median 7 days) but not significantly. Median system delay--time
between first medical consultation and first clinic visit--was 18 days. Patients
who thought they had cancer and those so diagnosed were seen more promptly
(median 14 days). Most factors, including socio-economic status and ethnicity
were non-contributory. Beliefs about breast symptoms and their attribution are
the most important factors determining when women present. Health education
messages should aim to convince symptomatic women that their condition requires
urgent evaluation, without engendering fear in them.
PMID- 10682693
TI - Retrospective study of the relationships between age, inflammation and the
isolation of bacteria from the lower respiratory tract of thoroughbred horses.
AB - A total of 1235 tracheal aspirates taken from 724 thoroughbreds in race training,
aged from two to 10 years, were examined cytologically and bacteriologically. An
inflammation scoring system on a scale of 0 to 9 was devised to allow the
severity of lower airway disease to be assessed from the cytological results. The
inflammation scores were closely related to the isolation of bacteria (P<0.001),
and the most common bacterial isolates were Streptococcus zooepidemicus,
Streptococcus pneumoniae and Pasteurella/Actinobacillus-like species. Lower
airway disease was less common in older horses (P = 0.031), and the groups at
highest risk were the two- and four-year-olds. Lower airway inflammation was more
common in the four-year-olds at National Hunt yards than in the four-year-olds at
flat racing yards (P = 0.040, odds ratio = 3.80).
PMID- 10682694
TI - Survey of retinal haemorrhages in neonatal thoroughbred foals.
AB - Twenty-seven of 167 neonatal thoroughbred foals (16 per cent) were found to have
retinal haemorrhages after a careful examination of the entire fundus. Experience
in differentiating haemorrhages from other lesions, and the selection of foals
from normal populations, were considered to have an important effect on their
apparent incidence. Bilateral haemorrhages were more common and there was a
significantly higher incidence in female foals. The numbers of haemorrhages
ranged between one and 20; 36 per cent of eyes with retinal haemorrhages had the
small punctate type and 56 per cent had the splash-like form. There was no change
from one type of haemorrhage to another, and the patterns of resolution were
similar. The haemorrhages were in the tapetal fundus, except two that were
recorded in the optic disc, and they resolved within 10 days. No short- or long
term ocular or neurological effects of the retinal haemorrhages were detected,
and they were not related to the incidence of abnormal foal behaviour.
PMID- 10682695
TI - Transfer of chlortetracycline from contaminated feedingstuff to cows' milk.
AB - Three groups of four Friesian cows in mid-lactation were fed a compound
feedingstuff contaminated with 2, 10 or 300 mg chlortetracycline/kg for 21 days,
and were then fed an uncontaminated diet for seven days. A fourth group of four
cows was fed an uncontaminated diet throughout the study. Daily pooled milk
samples from each cow were analysed by high performance liquid chromatography
(HPLC) with a detection limit of 50 microg chlortetracycline/litre.
Chlortetracycline was detected in only two milk samples taken from one of the
animals fed feed containing 300 mg 300 mg chlortetracycline/kg, and both
contained less than the maximum residue limit (MRL) specified by the European
Union (100 microg/litre). All the milk samples were also analysed by the
Delvotest SP microbiological assay, which has a detection limit of 300 microg
chlortetracycline/litre. During the treatment period, this method gave four
presumptive false-positive results, because they were not confirmed by HPLC.
Selected daily pooled samples from each treatment group were also analysed by the
semi-quantitative Charm II radioreceptor assay with a detection limit of 10
microg chlortetracycline/litre. Immunoreactive chlortetracycline was detected
only in the animals fed feed containing 300 mg chlortetracycline/kg and several
of the results exceeded the EU MRL during the treatment period. No significant
treatment effects on animal performance were observed. However, there was a trend
towards a higher milk fat concentration (P<0.09) and a lower milk protein
concentration (P<0.07) with increasing concentration of chlortetracycline in the
diet.
PMID- 10682696
TI - African horse sickness in Senegal: serotype identification and nucleotide
sequence determination of segment S10 by RT-PCR.
PMID- 10682697
TI - Transport stress in cattle as reflected by an increase in faecal cortisol
metabolite concentrations.
PMID- 10682698
TI - Student debt and socioeconomic mix.
PMID- 10682699
TI - Clomipramine and behavioural therapy in the treatment of separation-related
problems in dogs.
PMID- 10682700
TI - Inositol trisphosphate and cyclic adenosine diphosphate-ribose increase quantal
transmitter release at frog motor nerve terminals: possible involvement of smooth
endoplasmic reticulum.
AB - The release of chemical transmitter from nerve terminals is critically dependent
on a transient increase in intracellular Ca2+. The increase in Ca2+ may be due to
influx of Ca2+ from the extracellular fluid or release of Ca2+ from intracellular
stores such as mitochondria. Whether Ca2+ utilized in transmitter release is
liberated from organelles other than mitochondria is uncertain. Smooth
endoplasmic reticulum is known to release Ca2+, e.g., on activation by inositol
trisphosphate or cyclic adenosine diphosphate-ribose, so the possibility exists
that Ca2+ from this source may be involved in the events leading to exocytosis.
We examined this hypothesis by testing whether inositol trisphosphate and cyclic
adenosine diphosphate-ribose modified transmitter release. We used liposomes to
deliver these agents into the cytoplasmic compartment and binomial analysis to
determine their effects on the quantal components of transmitter release.
Administration of inositol trisphosphate (10(-4)M) caused a rapid, 25% increase
in the number of quanta released. This was due to an increase in the number of
functional release sites, as the other quantal parameters were unaffected. The
effect was reversed with 40 min of wash. Virtually identical results were
obtained with cyclic adenosine diphosphate-ribose (10(-4)M). Inositol
trisphosphate caused a 10% increase in quantal size, whereas cyclic adenosine
diphosphate-ribose had no effect. The results suggest that quantal transmitter
release can be increased by Ca2+ released from smooth endoplasmic reticulum upon
stimulation by inositol trisphosphate or cyclic adenosine diphosphate-ribose.
This may involve priming of synaptic vesicles at the release sites or
mobilization of vesicles to the active zone. Inositol trisphosphate may have an
additional action to increase the content of transmitter within the vesicles.
These findings raise the possibility of a role of endogenous inositol phosphate
and smooth endoplasmic reticulum in the regulation of cytoplasmic Ca2+ and
transmitter release.
PMID- 10682701
TI - Cortical cholinergic inputs mediating arousal, attentional processing and
dreaming: differential afferent regulation of the basal forebrain by
telencephalic and brainstem afferents.
AB - Basal forebrain corticopetal neurons participate in the mediation of arousal,
specific attentional functions and rapid eye movement sleep-associated dreaming.
Recent studies on the afferent regulation of basal forebrain neurons by
telencephalic and brainstem inputs have provided the basis for hypotheses which,
collectively, propose that the involvement of basal forebrain corticopetal
projections in arousal, attention and dreaming can be dissociated on the basis of
their regulation via major afferent projections. While the processing underlying
sustained, selective and divided attention performance depends on the integrity
of the telencephalic afferent regulation of basal forebrain corticopetal neurons,
arousal-induced attentional processing (i.e. stimulus detection, selection and
processing as a result of a novel, highly salient, aversive or incentive stimuli)
is mediated via the ability of brainstem ascending noradrenergic projections to
the basal forebrain to activate or "recruit" these telencephalic afferent
circuits of the basal forebrain. In rapid eye movement sleep, both the basal
forebrain and thalamic cortiocopetal projections are stimulated by cholinergic
afferents originating mainly from the pedunculopontine and laterodorsal tegmenta
in the brainstem. Rapid eye movement sleep-associated dreaming is described as a
form of hyperattentional processing, mediated by increased activity of cortical
cholinergic inputs and their cortical interactions with activated thalamic
efferents. In this context, long-standing speculations about the similarities
between dreaming and psychotic cognition are substantiated by describing the role
of an over(re)active cortical cholinergic input system in either condition.
Finally, while determination of the afferent regulation of basal forebrain
corticopetal neurons in different behavioral/cognitive states assists in defining
the general cognitive functions of cortical acetylcholine, this research requires
a specification of the precise anatomical organization of basal forebrain
afferents and their interactions in the basal forebrain. Furthermore, the present
hypotheses remain incomplete because of the paucity of data concerning the
regulation and role of basal forebrain non-cholinergic, particularly GABAergic,
efferents.
PMID- 10682702
TI - Cortical and subcortical influences on the nucleus of the optic tract of the
opossum.
AB - In the present work we propose a new phylogenetic hypothesis for the role played
by cortical and subcortical afferents to the nucleus of the optical tract, the
main visual relay station of the horizontal optokinetic reflex in mammals. The
hypothesis is supported by anatomical and physiological data obtained in the
South American opossum (Didelphis aurita) using the following experimental
approaches: (i) single-unit recordings in the nucleus of the optic tract and
simultaneous electrical stimulation of the contralateral nucleus of the optic
tract; (ii) single-unit recordings in the nucleus of the optic tract and
simultaneous electrical stimulation of the ipsilateral striate cortex; (iii)
injection of cholera toxin subunit B into the striate cortex and subsequent
immunohistochemical reaction to reveal the presence of the marker in the thalamus
and mesencephalon; and (iv) single-unit recordings in the nucleus of the optic
tract both before and after ablation of the ipsilateral visual cortex. The main
results are: (i) there is a strong inhibitory reciprocal effect upon the nucleus
of the optic tract following stimulation of its contralateral counterpart; (ii)
electrophysiological and anatomical data imply that the visual cortex does not
project directly to the nucleus of the optic tract. Rather, cortical terminals
seem to target the nearby anterior and posterior pretectal nuclei and orthodromic
latencies in the nucleus of the optic tract following stimulation of the visual
cortex were twice as large as in the superior colicullus; and (iii) ablation of
the entire visual cortex did not have any effect upon binocularity of cells in
the nucleus of the optic tract. These results strengthen the model proposed here
for the role of the interactions between the nuclei of the optic tract under
optokinetic stimulation. The hypothesis in the present work is that the cortical
influences upon the nucleus of the optical tract, in addition to the subcortical
ones, appeared only recently in phylogenesis. In more primitive mammals, such as
the opossum, subcortical interactions are thought to play a relatively important
role. With the emergence of retinal specializations, such as the fovea, one might
suppose that there followed the appearance of new ocular movements, such as the
smooth pursuit and certain types of saccades, that came to join the pre-existent
optokinetic reflex.
PMID- 10682703
TI - Subthreshold inward membrane currents in guinea-pig frontal cortex neurons.
AB - Current-clamp and single-electrode voltage-clamp recordings were used to study
the inward currents activated in the subthreshold membrane potential range of
cortical pyramidal neurons. The experiments were done on slices from guinea-pig
frontal cortex and all recordings were obtained at a distance of 600-900 microm
from the pial surface. In current-clamp recordings and from membrane potentials
hyperpolarized to about -70 mV, the depolarization leading to spike firing was
partially blocked by 1 microM tetrodotoxin, but not by calcium-free extracellular
solution. The calcium-free solution only affected this depolarization when the
membrane potential was held at a level more negative than -75 mV. Under voltage
clamp, an inward current was recorded between the resting membrane potential and
the level of spike firing. This current was activated at about -60 mV and part of
it was blocked by 1 microM tetrodotoxin; the remaining current was blocked by
calcium-free extracellular solution. In five neurons both components were
recorded and isolated in the same cell. The tetrodotoxin-sensitive component
activated at close to -60 mV, was similar to the persistent sodium current (I(Na
p)). The Ca2+-sensitive component activated at close to -60 or -65 mV, was less
voltage-dependent than I(Na-p). This component was similar to the low threshold
calcium current (I(T)). These results suggest that the subthreshold
depolarization which led to spike firing was dependent on I(Na-p) and I(T), I(Na
p) being the most important factor up to resting membrane potentials of -70 or
75 mV. A physiological role of this finding is revealed by the action of
dopamine, which (at 10 microM) prevented the firing of action potentials from -60
mV, but not from -80 mV due to the inhibition of I(Na-p) and the lack of effect
on I(T).
PMID- 10682704
TI - Subcellular localization of glutamate-stimulated intracellular magnesium
concentration changes in cultured rat forebrain neurons using confocal
microscopy.
AB - Glutamate can stimulate increases in intracellular magnesium concentration
([Mg2+]i) and induce neurotoxicity, both independent of Ca2+ changes. Although
Mg2+ is essential within the cell, very little is known about how it is
regulated, especially in neurons. Therefore we used the fluorescent indicator,
magindo-1 and confocal microscopy to examine possible intracellular pools of Mg2+
in cultured neurons that can be dynamically regulated by glutamate. The magindo-1
fluorescence signal was present throughout the cell body and extends into the
neuronal processes. The magindo-1 405 nm/490 nm ratio signal was similar in the
cytoplasm and nucleus, suggesting that resting [Mg2+]i is uniform across the
neuron. The addition of 100 microM glutamate/10 microM glycine in an
extracellular Ca2+- and Na+-free buffer stimulated an increase in [Mg2+]i in both
the nuclear and cytoplasmic regions of similar magnitude and duration. This
glutamate exposure also stimulated a [Mg2+]i increase in neuronal processes which
was inhibited by the N-methyl-D-aspartate receptor antagonist, MK-801 (10
microM). The glutamate-stimulated [Mg2+]i increase in both the cell body and
neuronal processes was dependent on the extracellular Mg2+ concentration. These
findings suggest glutamate-stimulated [Mg2+]i changes may not only impact
cytoplasmic processes, but also directly trigger nuclear events involved, for
example, in neuronal injury.
PMID- 10682705
TI - Gerbil angiotensin II AT1 receptors are highly expressed in the hippocampus and
cerebral cortex during postnatal development.
AB - Increasing evidence suggests that Angiotensin II, classically known from its many
effects regulating salt and water homeostasis, is also involved in brain
development and cognitive functions through activation of AT1 Angiotensin II
receptors. The recently cloned gerbil AT1 receptor is expressed in brain areas
controlling hydro-mineral homeostasis, and particularly highly expressed in
limbic areas such as the hippocampal formation. We quantified the gerbil AT1
receptor messenger RNA expression and receptor binding by quantitative in situ
hybridization and receptor autoradiography, respectively, in the hippocampal
formation and cerebral cortex of gerbils during postnatal development. The
receptor messenger RNA and binding were present from birth and showed a gradual
and sustained increase through postnatal maturation in the CA1 and CA2 regions of
the hippocampus and in the dentate gyrus. Conversely, in the CA3 region, no
binding was detected while receptor messenger RNA peaked at 15 days after birth
and disappeared in the adult. The highest receptor messenger RNA expression and
binding were found in the septomedial portions of the CA1 region and at septal
levels of the CA2 region. We detected the highest receptor messenger RNA
expression at postnatal day one in the frontolateral pole of the cerebral
hemispheres. In these areas, and in the frontoparietal and insular cortex,
receptor messenger RNA dramatically decreased during postnatal life. Similarly,
we found receptor messenger RNA expression in the cingulate, retrosplenial,
perirhinal and infralimbic cortex with higher values during the first two weeks
of development and decreased expression in the adult. However, receptor binding
in the cerebral cortex, did not decrease during postnatal life. The differential
profile of receptor messenger RNA expression and binding in the gerbil cortex and
hippocampus during postnatal maturation suggest a role for AT1 receptors in the
development and function of the corticohippocampal system.
PMID- 10682706
TI - Endothelin b receptor deficiency is associated with an increased rate of neuronal
apoptosis in the dentate gyrus.
AB - The dentate gyrus retains neuronal proliferative potential throughout life. Using
immature endothelin B receptor-deficient (sl/sl) rats, a rabbit model of
pneumococcal meningitis and autopsy brains from humans who died from pneumococcal
meningitis, we explored the role of endothelin B receptors in physiological and
pathological neuronal apoptosis in the dentate gyrus. At postnatal days 3-4, the
rate of apoptosis in the dentate gyrus was high in all rats, declining to low
levels in wild-type rats (+/+) on days 14 and 22, but remaining high in both
homozygous (sl/sl) and heterozygous (sl/+) endothelin B receptor-deficient rats.
Increased apoptosis was not significantly compensated for by neuronal
proliferation. Hippocampal neuronal cultures also exhibited genotype-dependent
apoptosis with the highest rate in neurons from homozygous endothelin B receptor
deficient (sl/sl) rats. In rabbit and human pneumococcal meningitis, increased
apoptosis in the dentate gyrus was associated with loss of neuronal endothelin B
receptor immunoreactivity. In conclusion, endothelin B receptors appear to act as
neuronal survival factors in the dentate gyrus in rodents and man, both during
postnatal development and under pathological conditions.
PMID- 10682707
TI - Expression of brain-derived neurotrophic factor, neurotrophin-3 and their
receptor messenger RNAs in monkey rhinal cortex.
AB - The primate rhinal cortex, consisting of areas 36 and 35 of the perirhinal cortex
and the entorhinal cortex (area 28), plays a crucial role in perception and
memory. We investigated the expression of messenger RNAs for brain-derived
neurotrophic factor and neurotrophin-3, as well as those for their respective
tyrosine kinase receptors, TrkB and TrkC, in the monkey rhinal cortex. Results
from in situ hybridization revealed that each of these messenger RNAs was
expressed in neurons with distinct laminar and areal patterns of distribution.
Brain-derived neurotrophic factor messenger RNA was principally detected in
layers V/ VI of area 36, and layers II/III and V of the entorhinal cortex. Some
of the messenger RNA-positive cells in the deep layers of the rhinal cortex were
confirmed to exhibit a pyramidal cell-like morphology. Neurotrophin-3 messenger
RNA expression was confined to layers II/III of the entorhinal cortex. In
contrast, trkB and trkC messenger RNAs were expressed rather homogeneously and
abundantly throughout the rhinal cortex. The laminar and cellular distributions
of brain-derived neurotrophic factor and neurotrophin-3 messenger RNAs indicate
the predominant expression of these neurotrophins in projection neurons. These
results suggest that brain-derived neurotrophic factor and neurotrophin-3
regulate neuronal connectivities of forward and backward projections from the
rhinal cortex and contribute to functional reorganization underlying the
formation and maintenance of long-term memory in primates.
PMID- 10682708
TI - Glial cell line-derived neurotrophic factor receptor alpha1 availability
regulates glial cell line-derived neurotrophic factor signaling: evidence from
mice carrying one or two mutated alleles.
AB - Glial cell line-derived neurotrophic factor receptor alpha1 (GFRalpha1, also
known as GDNFR-alpha) is a glycolipid-anchored membrane protein of the GFRalpha
family, which binds glial cell line-derived neurotrophic factor [Jing S. et al.
(1996) Cell 85, 1113-1124; Treanor J. J. et al. (1996) Nature 382, 80-83], a
survival factor for several populations of central and peripheral neurons,
including midbrain dopamine neurons [Lin L. F. et al. (1993) Science 260, 1130
1132], and mediates its ligand-induced cell response via a tyrosine kinase
receptor called Ret [Takahashi M. et al. (1988) Oncogene 3, 571-578; Takahashi M.
and Cooper G. M. (1987) Molec. Cell Biol. 7, 1378-1385]. In this paper, we show
that mice with a null mutation of the GFRalpha1 gene manifest epithelial
mesenchymal interaction deficits in kidney and severe disturbances of intestinal
tract development similar to those seen with glial cell line-derived neurotrophic
factor or Ret null mutations. There is a marked renal dysgenesis or agenesis and
the intrinsic enteric nervous system fails completely to develop. We also show
that newborn GFRalpha1-deficient mice display no or minimal changes in dorsal
root and sympathetic ganglia. This is in contrast to the deficits reported in
these neuronal populations in glial cell line-derived neurotrophic factor and Ret
null mutations. Mesencephalic dopaminergic neurons in the substantia nigra and
ventral tegmental area appear intact at the time of birth of the mutated mice.
Mice homozygous for the GFRalpha1 null mutation die within 24 h of birth because
of uremia. Heterozygous animals, however, live to adulthood. There is a
significantly reduced neuroprotective effect of glial cell line-derived
neurotrophic factor in such heterozygous animals, compared with wild-type
littermates, after cerebral ischemia. Taken together with previous data on glial
cell line-derived neurotrophic factor and Ret, our results strongly suggest that
GFRalpha1 is the essential GFRalpha receptor for signaling in the glial cell line
derived neurotrophic factor-Ret pathway in the kidney and enteric nervous system
development, and that GFRalpha2 or GFRalpha3 cannot substitute for the absence of
GFRalpha1. Moreover, neuroprotective actions of exogenous glial cell line-derived
neurotrophic factor also require full GFRalpha1 receptor expression.
PMID- 10682709
TI - Early direct and transneuronal effects in mice with targeted expression of a
toxin gene to D1 dopamine receptor neurons.
AB - The neurochemical profile was examined at postnatal day 3-4 in mutant mice
generated by in vivo Cre mediated activation of an attenuated diphtheria toxin
gene inserted into the D1 dopamine receptor gene locus. An earlier study of this
model had shown that D1 dopamine receptor, substance P and dynorphin were not
expressed in the striatum. Quantitative in situ hybridization analysis showed an
increase in D2 dopamine receptor and enkephalin messenger RNA expression. The
nigrostriatal pathway in the mutant pups was intact with a normal number of
dopaminergic neurons in the substantia nigra and the ventral tegmental area in
addition to a normal pattern of striatal dopamine transporter and tyrosine
hydroxylase immunoreactivity. Quantitative analysis of striatal dopamine
transporter density using [3H]mazindol showed a reduction of 26% suggesting a
degree of transneuronal down-regulation. There was also a 49% reduction of
striatal GABA receptor binding and a 36% reduction of striatal muscarinic
receptor binding in mutant pups. The number of healthy striatal neuropeptide Y
containing interneurons was also substantially down-regulated in the mutant
striatum. In contrast, there was an increase in the number of striatal
cholinergic interneurons. Down-regulated cortical GABA receptor and muscarinic
receptor binding was also observed in addition to subtle morphological changes in
the neuropeptide Y-expressing population of cortical neurons. The changes reflect
the early cascade of events which follows the ablation of D1 dopamine receptor
positive cells. Although extensive changes in a number of striatal and cortical
neurons were demonstrated, only subtle transneuronal effects were seen in the
nigrostriatal pathway.
PMID- 10682710
TI - Late direct and transneuronal effects in mice with targeted expression of a toxin
gene to D1 dopamine receptor neurons.
AB - Detailed analysis of a novel transgenic model of basal ganglia disease has been
undertaken. In this model the expression of an attenuated form of the diphtheria
toxin gene was tightly controlled by D1 dopamine receptor regulatory domains. The
behavioral and both direct toxin-mediated and transneuronal effects observed in
pups in the first postnatal week have been described. Although younger pups are
bradykinetic, older pups have a hyperkinetic syndrome with gait abnormality,
postural instability and myoclonic jerks typical of human basal ganglia diseases
such as Huntington's disease. As expected, striatal D1 dopamine receptor,
dynorphin and substance P transcripts were not detected by in situ hybridization
but there was a 27% increase in striatal D2 dopamine receptor messenger RNA and a
65% increase in enkephalin messenger RNA expression. Receptor autoradiographic
studies confirmed the lack of D1-class binding in the mutant striatum and in
contrast to young pups, a substantial increase in striatal D2-class binding.
Autoradiographic quantitation also showed a 30% increase in striatal dopamine
transporter binding. In addition to the changes described in the striatopallidal
and nigrostriatal pathways, up-regulated dynorphin and substance P messenger RNA
expression was also seen in the cortex. The capacity of the developing brain for
neurochemical adaptation following injury is dramatic. The results show that
primary loss of D1 dopamine receptor-positive striatonigral pathway neurons is
sufficient to generate a hyperkinetic phenotype.
PMID- 10682711
TI - Inhibitory control of the GABAergic transmission in the rat neostriatum by D2
dopamine receptors.
AB - The aim of the study was to determine the role of dopamine on the GABAergic input
to striatal projection neurons. Accordingly, the effect of the activation of
dopamine D2-like receptors on GABA-mediated depolarizing postsynaptic potentials
evoked in striatal slices by local stimulation was studied. Conventional
intracellular recording techniques were used to record the synaptic responses.
The experiments were done in the presence of 6-cyano-7-nitroquinoxaline-2,3-dione
(20 microM) and (+)-2-amino-5-phosphonovaleric acid (40 microM) to block the
participation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate/kainate and
N-methyl-D-aspartate receptors in the synaptic response. The GABAergic nature of
the response was assessed by its potentiation by pentobarbital (50 microM) and by
its elimination by bicuculline or picrotoxin. At 100 nM, a concentration already
maximal, dopamine inhibited by 55% the GABAergic synaptic response. The
inhibitory effect was totally blocked by the selective antagonist of D2-like
receptors, sulpiride (100 nM). The dopamine inhibition was observed only in one
third of the studied neurons and was concentration dependent (IC50 = 14 nM). The
inhibition was not associated with changes in the input resistance or any other
membrane property. In addition, dopamine (50 nM) reduced the frequency but not
the amplitude of spontaneous, bicuculline-sensitive depolarizing postsynaptic
potentials. The D2-like receptor agonist quinpirole also dose-dependently (IC50 =
10 nM) inhibited the GABAergic synaptic response. As with dopamine, the
inhibition did not change the membrane properties of the studied neurons. In
addition, the quinpirole induced inhibition of the GABA response was accompanied
by increased paired-pulse facilitation. The results indicate that D2-like
receptors located on intrinsic GABAergic terminals in the rat striatum exert an
inhibitory control of the GABAergic input to striatal projection neurons. The
dopaminergic effect would be translated in facilitation of the firing of the
neurons upon the arrival of the cortical input.
PMID- 10682712
TI - Effect of acute and chronic administration of 1,2,3,4-tetrahydroisoquinoline on
muscle tone, metabolism of dopamine in the striatum and tyrosine hydroxylase
immunocytochemistry in the substantia nigra, in rats.
AB - The effects of acute and chronic administration of 1,2,3,4
tetrahydroisoquinoline, an endogenous substance suspected of producing
parkinsonism in humans, on the muscle tone and metabolism of dopamine in the
striatum, and on the number of tyrosine hydroxylase-immunoreactive cells in the
substantia nigra were investigated in rats. Muscle tone was examined using a
combined mechanomyographic and electromyographic method which measured
simultaneously the muscle resistance of the rat's hind foot to passive extension
and flexion in the ankle joint and electromyographic activity of the antagonistic
muscles of that joint: gastrocnemius and tibialis anterior. 1,2,3,4
Tetrahydroisoquinoline administered at doses of 50 and 100 mg/kg
intraperitoneally for 19 days increased muscle resistance 1 h after the first
injection (acute treatment), 1 h after the last injection (chronic treatment) and
three days after compound withdrawal. Rigidity observed on the third day of
1,2,3,4-tetrahydroisoquinoline withdrawal was accompanied by an increased tonic
(resting) electromyographic activity of the gastrocnemius and tibialis anterior
muscles. At the same time, a significant reduction in the number of tyrosine
hydroxylase-immunoreactive neurons in the substantia nigra and a decrease in the
dopamine level in the striatum were also found. A declining number of tyrosine
hydroxylase-immunoreactive neurons in the whole substantia nigra showed a
significant negative correlation with the enhanced muscle resistance, as well as
with the tonic electromyographic activity recorded at rest, i.e. before the start
of movements, from the gastrocnemius and tibialis anterior muscles. Our results
suggest that 1,2,3,4-tetrahydroisoquinoline may be one of the endogenous
substances involved in the progress of Parkinson's disease.
PMID- 10682713
TI - Dopamine release and uptake are greater in female than male rat striatum as
measured by fast cyclic voltammetry.
AB - The present studies investigated sexual dimorphisms in dopamine release and
uptake using fast-scan cyclic voltammetry in anesthetized rats and in brain
slices. Electrical stimulation of the medial forebrain bundle of anesthetized
rats at high frequency (60 Hz) elicited significantly more extracellular dopamine
in the caudate nucleus of females than males. This sex difference was apparent
over a range of current intensities applied to the stimulating electrode. Local
electrical stimulation of brain slices in vitro verified in vivo results as more
extracellular dopamine was elicited by single and 10 pulse stimulations in the
caudate nucleus of females. Kinetic analysis of in vivo and in vitro dopamine
overflow data indicated that dopamine release (the concentration of dopamine
released per stimulus pulse) and the maximal velocity of dopamine uptake are
greater in female rats, but the affinity of the transporter for dopamine was the
same in males and females. None of these three parameters varied across the
female estrous cycle. Linear regression analysis of dopamine release versus
maximal uptake velocity data indicated a significant association of release and
uptake sites in each sex and regression lines for males and females virtually
overlapped. One explanation for these results is greater dopamine neuron terminal
density in female caudate nucleus. These sexual dimorphisms in dopaminergic
neurotransmission provide a novel, plausible mechanism to explain robust sex
differences in behavioral responses of rats to psychostimulant drugs and may have
implications for human neurological disorders and drug abuse.
PMID- 10682714
TI - Lidocaine blockade of amygdala output in fear-conditioned rats reduces Fos
expression in the ventrolateral periaqueductal gray.
AB - We showed recently that conditioned fear to context induces Fos expression in the
ventrolateral periaqueductal gray [Neuroscience (1997) 78, 165-177]. Neurons in
this region are thought to play an important role in the expression of freezing
during conditioned fear. To test the possibility that this activation comes
directly from the amygdala, we looked at changes in Fos expression after a
unilateral blockade of the ventral amygdalofugal pathway with lidocaine. The
pathway contains fibres originating from the central nucleus of the amygdala that
project directly and mainly ipsilaterally to the ventrolateral periaqueductal
gray. Conditioned fear was evoked by re-exposing rats to the same box in which
they had previously received electric footshocks. The test re-exposure was
preceded by a unilateral microinjection of lidocaine (2%, 0.5-1 microl; n = 20)
or saline (n = 14). Lidocaine was also tested in non-conditioned animals (n =
13). The results show that, when lidocaine was microinjected in the medial part
of the central nucleus of the amygdala or along the ventral amygdalofugal pathway
of conditioned rats, fear-induced Fos expression in the ventrolateral
periaqueductal gray was reduced on the side ipsilateral to the injection (up to
37% reduction in comparison to the contralateral side). Ipsilateral reductions
were also observed with saline, but they were weaker (maximum of 27% reduction).
Fos expression remained low on both sides in the non-fear-conditioned animals
injected with lidocaine. Finally, although freezing was only partly reduced in
the conditioned animals unilaterally injected with lidocaine, it was
significantly correlated to the ipsilateral reduction in Fos expression. This
study provides direct evidence that the projection from the central nucleus of
the amygdala to the ventrolateral periaqueductal gray is activated during fear
and that it contributes to the Fos response of the ventrolateral periaqueductal
gray.
PMID- 10682715
TI - Correlations between serotonin level and single-cell firing in the rat's nucleus
raphe magnus.
AB - The relation between serotonin release and electrical activity was examined in
the nucleus raphe magnus of rats anesthetized with pentobarbital. Serotonin
levels were monitored through a carbon-fiber microelectrode by fast cyclic
voltammetry (usually at 1 Hz). Single-cell firing was recorded through the same
microelectrode, except during the voltammetry waveform and associated electrical
artifact (totaling about 30 ms). Multi-barrel micropipettes incorporating the
voltammetry electrode were used for iontophoresis of drugs. Cells were inhibited,
excited or unaffected by noxious mechanical skin stimulation. These were
respectively designated as off(M) cells, on(M) cells and neutral(M) cells, M
denoting mechanical. During 3 min of pinching, serotonin slowly rose near seven
of 14 on(M) cells and 26 of 46 off(M) cells; it fell near two off(M) cells; it
was unchanged near all other cells, including six neutral(M) cells. On a finer
spatiotemporal scale, near four of seven on(M) cells, 10 of 14 off(M) cells and 0
of four neutral(M) cells, average serotonin levels fell significantly within +/-
100 ms of spontaneous spikes. Lower serotonin may have caused the higher spike
probability; the converse is theoretically unlikely, since delays between release
and detection are estimated to exceed 100 ms. Increased serotonin and decreased
firing were always seen following iontophoresis or intravenous injection (1
mg/kg) of the serotonin re-uptake inhibitor clomipramine (n = 7). Iontophoresis
of +/- propranolol, whose serotonergic actions include antagonism and partial
agonism at 5-HT1 receptors, also increased serotonin and decreased firing (n=4).
Methiothepin (intravenous, 1 mg/kg), whose serotonergic actions include 5-HT1 and
5-HT2 antagonism, typically raised serotonin levels (four of five cells) and
always blocked inhibition by clomipramine (n = 3). Iontophoresis of glutamate
always lowered serotonin and increased firing (n = 4). Since serotonin levels and
firing were usually inversely correlated, except near on(M) cells during pinch,
we propose that serotonin is released from terminals of incoming nociceptive
afferents. Prior neuroanatomical knowledge favors a midbrain origin for these
afferents, while some of the drug findings suggest that their terminals possess
inhibitory serotonergic autoreceptors, possibly of 5-HT1b subtype. The released
serotonin could contribute to the inhibition of off(M) cells and excitation of
on(M) cells by noxious stimulation, since inhibitory 5-HT1a receptors and
excitatory 5-HT2 receptors, respectively, have previously been shown to dominate
their serotonergic responses.
PMID- 10682716
TI - Neurotrophin-induced rapid enhancement of membrane potential oscillations in
mesencephalic trigeminal neurons.
AB - We have proposed that neurotrophins, in addition to their trophic actions, act as
neuromodulators in the adult central nervous system. As a first step to test this
hypothesis, we examined in the adult rat slice preparation whether nerve growth
factor and neurotrophin-3 are capable of altering the excitability of neurons of
the mesencencephalic trigeminal nucleus. In contrast to vehicle pressure
microapplication, which did not evoke changes in the electrophysiological
properties of these neurons, neurotrophin application produced a significant
increase in amplitude of the membrane potential oscillatory activity that is
observed in these cells and a significant decrease in their threshold current.
The latency of these effects ranged from 2 to 80 s and the duration ranged from 2
to 11 min. Neurotrophin-3 induced a decrease in input resistance and resting
membrane potential in 58% of the cells; nerve growth factor induced a decrease in
input resistance and resting membrane potential in 35% of the neurons. The spike
configuration and action potential afterhyperpolarization potential remained
unchanged following neurotrophin application. Tetrodotoxin blocked the membrane
potential oscillatory activity of trigeminal mesencephalic neurons. Neurotrophin
induced effects were not blocked by the tyrosine kinase inhibitor K-252a, whereas
IgG-192, an antibody directed to the neurotrophin low-affinity receptor, enhanced
excitability, as did neurotrophins. These results demonstrate that neurotrophins
are capable of producing a rapid increase in the excitability of trigeminal
mesencephalic neurons and suggest that their effects may be mediated by low
affinity neurotrophin receptors.
PMID- 10682717
TI - Repeated stimuli for axonal growth causes motoneuron death in adult rats: the
effect of botulinum toxin followed by partial denervation.
AB - Axons of motoneurons to tibialis anterior and extensor digitorum longus muscles
of adult rats were induced to sprout by injecting botulinum toxin into them, by
partial denervation or by a combination of the two procedures. Ten weeks later,
the number of motoneurons innervating the control and operated tibialis anterior
and extensor digitorum longus muscles was established by retrograde labelling
with horseradish peroxidase. In the same preparations, the motoneurons were also
stained with a Nissl stain (gallocyanin) to reveal motoneurons in the sciatic
pool. Examination of the spinal cords from animals treated with botulinum toxin
showed that the number of retrogradely labelled cells and those stained with
gallocyanin in the ventral horn on the treated compared to the control side was
unchanged. In rats that had their L4 spinal nerve sectioned on one side, the
number of retrogradely labelled cells on the operated side was 48+/-3% (n = 5) of
that present in the control unoperated ventral horn. Thus, just over half the
innervation was removed by cutting the L4 spinal nerve. Counts made from
gallocyanin-stained sections showed that 94+/-4% (n = 5) of motoneurons were
present in the ventral horn on the operated side. Thus, section of the L4 spinal
nerve did not lead to any death of motoneurons. In rats that had their muscles
injected with botulinum toxin three weeks prior to partial denervation, the
number of retrogradely labelled cells was reduced from 48+/-3% (n = 5) to 35+/-4%
(n = 5). Moreover, only 67+/-5% (n = 5) of motoneurons stained with gallocyanin,
suggesting that a proportion of motoneurons died after this combined procedure.
This result was supported by experiments in which motor unit numbers in extensor
digitorum longus muscles were determined by measurements of stepwise increments
of force in response to stimulation of the motor nerve with increasing stimulus
intensity. In partially denervated extensor digitorum longus muscles, 16.6+/-0.7
(n = 5) motor units could be identified, and in animals treated with botulinum
toxin prior to partial denervation only 13.3+/-0.9 (n = 3) motor units were
present. Taken together, these results show that treatment with botulinum toxin
followed by partial denervation causes motoneuron death in adult rats.
PMID- 10682718
TI - Identification of differentially expressed genes in dorsal root ganglia following
partial sciatic nerve injury.
AB - Partial sciatic nerve injury, a model of neuropathic pain, elicits a variety of
neurochemical, electrophysiological and neuroanatomical changes in primary
sensory neurons. We have used the technique of messenger RNA differential display
to identify genes with altered expression in these neurons which may contribute
to the development of aberrant sensation following such peripheral nerve damage.
This approach identified 14 distinct complementary DNA clones, representing
transcripts with increased ipsilateral expression in L4/5 dorsal root ganglia,
two weeks after unilateral partial ligation of the rat sciatic nerve. Both Zucker
diabetic fatty rats and their lean counterparts were used in this study but none
of the transcripts identified showed an induction that was confined to one of the
two groups. The majority of the clones did not show significant sequence
similarity to previously reported genes and therefore may represent novel
messenger RNA sequences or, alternatively, unknown regions of partially
characterised messenger RNAs. Two of the clones represented transcripts for the
known proteins muscle LIM protein and acidic epididymal glycoprotein, neither of
which had previously been associated with expression in the nervous system.
Reverse transcriptase-polymerase chain reaction analysis and in situ
hybridization confirmed that the messenger RNA expression of both muscle LIM
protein and acidic epididymal glycoprotein was induced in an ipsilateral-specific
manner. Their localisations, examined with in situ hybridization in L5 dorsal
root ganglia, were limited in each case to a sub-population of neuronal profiles.
Those neuronal profiles that demonstrated muscle LIM protein hybridization were
distributed across the profile size range, whereas the distribution of acidic
epididymal glycoprotein-positive profiles appeared to be skewed towards smaller
profiles. The induction of muscle LIM protein and acidic epididymal glycoprotein
in dorsal root ganglia may play an important functional role in the adaptive
response of primary sensory neurons following partial sciatic nerve injury.
PMID- 10682719
TI - Calcium channels controlling acetylcholine release from preganglionic nerve
terminals in rat autonomic ganglia.
AB - Little is known about the nature of the calcium channels controlling
neurotransmitter release from preganglionic parasympathetic nerve fibres. In the
present study, the effects of selective calcium channel antagonists and amiloride
were investigated on ganglionic neurotransmission. Conventional intracellular
recording and focal extracellular recording techniques were used in rat
submandibular and pelvic ganglia, respectively. Excitatory postsynaptic
potentials and excitatory postsynaptic currents preceded by nerve terminal
impulses were recorded as a measure of acetylcholine release from parasympathetic
and sympathetic preganglionic fibres following nerve stimulation. The calcium
channel antagonists omega-conotoxin GVIA (N type), nifedipine and nimodipine (L
type), omega-conotoxin MVIIC and omega-agatoxin IVA (P/Q type), and Ni2+ (R type)
had no functional inhibitory effects on synaptic transmission in both
submandibular and pelvic ganglia. The potassium-sparing diuretic, amiloride, and
its analogue, dimethyl amiloride, produced a reversible and concentration
dependent inhibition of excitatory postsynaptic potential amplitude in the rat
submandibular ganglion. The amplitude and frequency of spontaneous excitatory
postsynaptic potentials and the sensitivity of the postsynaptic membrane to
acetylcholine were unaffected by amiloride. In the rat pelvic ganglion, amiloride
produced a concentration-dependent inhibition of excitatory postsynaptic currents
without causing any detectable effects on the amplitude or configuration of the
nerve terminal impulse. These results indicate that neurotransmitter release from
preganglionic parasympathetic and sympathetic nerve terminals is resistant to
inhibition by specific calcium channel antagonists of N-, L-, P/Q- and R-type
calcium channels. Amiloride acts presynaptically to inhibit evoked transmitter
release, but does not prevent action potential propagation in the nerve
terminals, suggesting that amiloride may block the pharmacologically distinct
calcium channel type(s) on rat preganglionic nerve terminals.
PMID- 10682720
TI - Muscarinic receptor activation is a prerequisite for the endogenous release of
nitric oxide modulating nicotinic transmission within the coeliac ganglion in the
rabbit.
AB - The aim of the present study was to investigate whether the activation of
muscarinic receptors is a preliminary step to the endogenous release of nitric
oxide modulating nicotinic transmission within the prevertebral ganglia. This
work has been performed in vitro in isolated rabbit coeliac ganglion. The
electrical activity of the ganglionic neurons was recorded using intracellular
recording techniques. When a train of pulses of supramaximal intensity was
applied to the splanchnic nerves, gradual depression of fast nicotinic
transmission occurred: the pulses do not systematically elicit action potentials,
but very often elicit excitatory postsynaptic potentials only. The use of
pharmacological agents that interfere with the nitric oxide pathway such as L
arginine (precursor of nitric oxide) or 2-(4-carboxyphenyl)-4,4,5,5
tetramethylimidazoline-1-oxyl-3-oxide (nitric oxide scavenger) demonstrated that
nitric oxide modulates this depression phenomenon by facilitating or inhibiting
the nicotinic transmission of the ganglionic neurons. A nitric oxide donor
(diethylamine/nitric oxide complex) induced an inhibition of the nicotinic
synaptic transmission. In the presence of the muscarinic receptors antagonist
atropine, L-arginine and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1
oxyl-3-oxide failed to modify the nicotinic transmission of the ganglionic
neurons but diethylamine/nitric oxide complex was still able to inhibit it. These
results demonstrate that in the coeliac ganglion, the activation of muscarinic
cholinergic receptors is a prerequisite for the activation of neuronal nitric
oxide synthase in preganglionic fibres. The nitric oxide released then exerts a
facilitation or an inhibition of the nicotinic transmission of the ganglionic
neurons. Atropine triggered a facilitation of the nicotinic transmission when
superfused alone and an inhibition when superfused in the presence of 2-(4
carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. These results
confirm that muscarinic receptors activate the nitric oxide pathway modulating
the nicotinic transmission of the prevertebral neurons. Our results also
demonstrate that when the nitric oxide pathway is blocked, activation of
muscarinic receptors leads to facilitation of the nicotinic transmission. Our
study brings new insights concerning the modulation by nitric oxide and by
muscarinic receptors of the synaptic transmission within the prevertebral
ganglia.
PMID- 10682721
TI - Localization of metabotropic glutamate receptor type 2 in the human brain.
AB - Metabotropic glutamate receptors are a heterogeneous family of G-protein-coupled
receptors that are linked to multiple second messenger systems to regulate
neuronal excitability and synaptic transmission. To elucidate the physiological
role of these receptors in human central nervous system function and dysfunction
at the receptor protein level requires the use of selective antibodies to
determine the phenotype of cells expressing particular receptor subtypes. To this
end the present study has examined the regional and cellular localization of the
metabotropic glutamate type 2 receptor protein in selected human brain regions.
After epitope prediction, antibodies have been generated against a short
synthetic peptide corresponding to amino acid residues located in the putative
intracellular carboxy-terminus and subsequently applied to an immunohistochemical
investigation. Antibodies specifically detected the type 2 receptor in
transfected mammalian cells and also recognized a major band of 98,000 mol. wt in
western blots of human brain tissue membranes. At the light microscope level
immunohistochemical studies have demonstrated that type 2-like immunoreactivity
was widely distributed in the human brain, being characterized by the presence of
a strong immunoreaction in multiple cortical regions, and in structures
comprising the basal ganglia, to include the caudate nucleus, putamen, globus
pallidus, substantia nigra and subthalamic nucleus. In the hippocampal formation,
immunoreactivity was predominant in selective cell layers of both the dentate
gyrus and cornu ammonis, the subicular complex and entorhinal cortex. In the
thalamus, multiple subnuclei showed reaction product. In the cerebellar cortex,
immunoreactivity was expressed in a number of cell layers and cell types.
Furthermore, using double immunofluorescence we confirmed that the type 2
receptor is a product of normal resting astrocytes in the cerebral cortex in
particular. This antibody provides a new immunological tool with the potential to
evaluate the distribution of human metabotropic glutamate receptor 2 protein in
other brain regions and in human central nervous system diseases.
PMID- 10682722
TI - Involvement of caspase-1 proteases in hypoxic brain injury. effects of their
inhibitors in developing neurons.
AB - To further explore the contribution of caspase-1/interleukin-1beta-convening
enzyme in the consequences of hypoxia in developing brain neurons, its temporal
expression profile was analysed by immunohistochemistry and western blotting in
cultured neurons from the embryonic rat forebrain subjected to a hypoxic stress
(95% N2/5% CO2 for 6 h), and proteolytic activity of caspase-1 was monitored as a
function of time by measuring the degradation of a selective colorimetric
substrate (N-acetyl-Tyr-Val-Ala-Asp-p-nitroanilide). In addition, the influence
of pre- and posthypoxic treatments by caspase-1 inhibitors (N-acetyl-Tyr-Val-Ala
Asp-aldehyde and N-acetyl-Tyr-Val-Ala-Asp-chloromethylketone) was tested on cell
outcome. Hypoxia led to delayed apoptotic neuronal death, with an elevation of
the expression of both pro-caspase-1 and caspase-1 active cleavage product (ICE
p20) for up to 96 h after cell reoxygenation. As reflected by cleavage of the
specific substrate, caspase-1 activity progressively increased between 24 h and
96 h posthypoxia, and was blocked by inhibitors in a dose-dependent fashion. The
inhibitory compounds, including when given 24 h after hypoxia, prevented neuronal
death, reduced apoptosis hallmarks and also increased the number of mitotic
neurons, suggesting they might promote neurogenesis. Similar observations were
made when neurons were exposed to a sublethal hypoxia (i.e. 3 h). These data
emphasize the participation of caspase-1 in neuronal injury consecutive to oxygen
deprivation, and provide new insight into the possible cellular mechanisms by
which caspase inhibitors may protect developing brain neurons.
PMID- 10682723
TI - Sites of action of thyrotropin-releasing hormone on central nervous system
neurons revealed by expression of the immediate-early gene c-fos in the rat.
AB - Centrally administered thyrotropin-releasing hormone produces a number of
physiological and behavioral changes, e.g., a general antidepressant effect,
increasing body temperature, and elevated blood pressure. However, the specific
brain sites of action responsible for the centrally activating property of
thyrotropin-releasing hormone have not been precisely determined. Using chloral
hydrate-anesthetized adult Sprague-Dawley rats, we compared the distribution of
Fos-like immunoreactivity after intracerebroventricular administration of
thyrotropin-releasing hormone with the results after intracerebroventricular
injection of vehicle alone. Some rats were paralysed and artificially ventilated
to avoid possible Fos expression secondarily induced by autonomic (e.g.,
respiratory) disturbances. In thyrotropin-releasing hormone administered rats,
selective Fos-like immunoreactivity was observed in V/VI layers of the pre- and
infralimbic areas of the medial prefrontal cortex, the ventral midline thalamus,
and the nucleus of the solitary tract as well as in the adjacent reticular
formation. Fos-like immunoreactivity was significantly reduced in most areas of
the cerebral cortex (II/III layers), the shell of the nucleus accumbens, the
medial amygdaloid nucleus, parts of the hypothalamus, and the periaqueductal
gray. These data suggest that various behavioral and autonomic responses induced
by centrally administered thyrotropin-releasing hormone might be produced through
the complex neural circuitry comprising the above structures, which are presumed
to be implicated in limbic and/or autonomic functions.
PMID- 10682724
TI - Repair of articular cartilage defects one year after treatment with recombinant
human bone morphogenetic protein-2 (rhBMP-2).
AB - BACKGROUND: Damaged articular cartilage has a limited ability to repair.
Operative removal of damaged cartilage and penetration into the subchondral bone
to allow population of the defect with progenitor cells can result in filling of
the defect with repair tissue. However, this repair tissue often degenerates over
time because of its inability to withstand the mechanical forces to which it is
subjected. We previously reported that recombinant human bone morphogenetic
protein-2 (rhBMP-2) improves the repair of full-thickness defects of cartilage as
long as six months postoperatively. We have now extended that study to examine
the quality of the repair tissue at one year. METHODS: Full-thickness defects of
cartilage were created in the trochlear groove of twenty-five adult New Zealand
White rabbits. Eight defects were left empty, eight were filled with a collagen
sponge, and nine were filled with a collagen sponge impregnated with five
micrograms of rhBMP-2. The animals were killed at fifty-two weeks
postoperatively, and the gross appearance of the healed defect was assessed. The
repair tissue was examined histologically and was evaluated, according to a
grading scale, by four individuals who were blinded with respect to the
treatment. The tissue sections were immunostained with antibodies against type-I
collagen, type-II collagen, aggrecan, and link protein. The residence time of the
rhBMP-2 in the cartilage defect was evaluated in vivo with use of scintigraphic
imaging of radiolabeled protein. RESULTS: One year after a single implantation of
a collagen sponge containing five micrograms of rhBMP-2, the defects had a
significantly better histological appearance than the untreated defects (those
left empty or filled with a collagen sponge). The histological features that
showed improvement were integration at the margin, cellular morphology,
architecture within the defect, and reformation of the tidemark. The total scores
were also better for the defects treated with rhBMP-2 than for the untreated
defects, but in no instance was the repair tissue identical to normal articular
cartilage. The thickness of the cartilage in the defects treated with rhBMP-2 was
70 percent that of the normal cartilage, an observation that was identical to
that at twenty-four weeks postoperatively. Immunostaining demonstrated
significantly less type-I collagen in the defects treated with rhBMP-2 than in
the untreated defects. Immunostaining for other matrix components showed no
difference among the treatment groups. The mean residence time of rhBMP-2 in the
cartilage defects was eight days with an elimination half-life of 5.6 days.
Detectable amounts of rhBMP-2 were present as long as fourteen days after
implantation. CONCLUSIONS: The problems associated with operative repair of
cartilage include the formation of fibrocartilage rather than normal articular
cartilage and the degeneration of that repair tissue over time. Our results
demonstrate that the addition of rhBMP-2 to the operative site after creation of
a full-thickness defect results in an improvement in the histological appearance
and composition of the extracellular matrix at one year postoperatively. If these
experimental results translate directly to the clinical situation, it is possible
that the addition of rhBMP-2 to existing operative treatments for the repair of
cartilage may improve the repair process and may help to maintain the integrity
of the repair tissue.
PMID- 10682725
TI - Ciprofloxacin inhibition of experimental fracture healing.
AB - BACKGROUND: Fluoroquinolones, such as ciprofloxacin, have an adverse effect on
growing cartilage and endochondral ossification in children. This study was
carried out to determine whether ciprofloxacin also has an adverse effect on the
healing of experimental fractures. METHODS: Sixty male 300-gram Wistar rats were
divided equally into three groups, which received ciprofloxacin, cefazolin, or no
treatment for three weeks, beginning seven days after production of a closed,
nondisplaced, bilateral femoral fracture. The serum concentrations of the
ciprofloxacin and the cefazolin were 2.4 and 146 micrograms per milliliter,
respectively. Radiographic, histological, and biomechanical studies were used to
evaluate fracture-healing. RESULTS: Radiographs revealed significantly more
advanced healing of the control fractures compared with the fractures in the
ciprofloxacin-treated group (average stage, 2.1 compared with 1.5, p = 0.01). The
cefazolin-treated group was not different from the controls with respect to
radiographic healing (average stage, 1.8 compared with 2.1, p = 0.18). Torsional
strength-testing of fracture callus exposed to ciprofloxacin revealed a 16
percent decrease in strength compared with the controls (284 compared with 338
newton-millimeters, p = 0.04) and a 49 percent decrease in stiffness (twenty
compared with thirty-nine newton-millimeters per degree, p = 0.001). The
biomechanical strength in the cefazolin-treated group was not different from that
of the controls. Fracture calluses in the animals treated with ciprofloxacin
showed abnormalities in cartilage morphology and endochondral bone formation and
a significant decrease in the number of chondrocytes compared with the controls
(0.77 x 10(4) compared with 1.3 x 10(4) cells per square millimeter, p = 0.004).
CONCLUSIONS: These data suggest that experimental fractures exposed to
therapeutic concentrations of ciprofloxacin in serum demonstrate diminished
healing during the early stages of fracture repair. The administration of
ciprofloxacin during early fracture repair may compromise the clinical course of
fracture-healing.
PMID- 10682726
TI - Joint angular velocity in spastic gait and the influence of muscle-tendon
lengthening.
AB - BACKGROUND: Joint angular velocity (the rate of flexion and extension of a joint)
is related to the dynamics of muscle activation and force generation during
walking. Therefore, the goal of this research was to examine the joint angular
velocity in normal and spastic gait and changes resulting from muscle-tendon
lengthening (recession and tenotomy) in patients who have spastic cerebral palsy.
METHODS: The gait patterns of forty patients who had been diagnosed with spastic
cerebral palsy (mean age, 8.3 years; range, 3.7 to 14.8 years) and of seventy
three age-matched, normally developing subjects were evaluated with three
dimensional motion analysis and electromyography. The patients who had cerebral
palsy were evaluated before muscle-tendon lengthening and nine months after
treatment. RESULTS: The gait patterns of the patients who had cerebral palsy were
characterized by increased flexion of the knee in the stance phase, premature
plantar flexion of the ankle, and reduced joint angular velocities compared with
the patterns of the normally developing subjects. Even though muscle-tendon
lengthening altered sagittal joint angles in gait, the joint angular velocities
were generally unchanged at the hip and knee. Only the ankle demonstrated
modified angular velocities, including reduced dorsiflexion velocity at foot
strike and improved dorsiflexion velocity through mid-stance, after treatment.
Electromyographic changes included reduced amplitude of the gastrocnemius-soleus
during the loading phase and decreased knee coactivity (the ratio of quadriceps
and hamstring activation) at toe-off. Principal component analyses showed that,
compared with joint-angle data, joint angular velocity was better able to
discriminate between the gait patterns of the normal and cerebral palsy groups.
CONCLUSIONS: This study showed that muscle-tendon lengthening corrects
biomechanical alignment as reflected by changes in sagittal joint angles.
However, joint angular velocity and electromyographic data suggest that the
underlying neural input remains largely unchanged at the hip and knee.
Conversely, electromyographic changes and changes in velocity in the ankle
indicate that the activation pattern of the gastrocnemius-soleus complex in
response to stretch was altered by recession of the complex.
PMID- 10682727
TI - Electromyographic and gait analysis of forty-three patients after rotationplasty.
AB - BACKGROUND: Rotationplasty is considered to be a treatment option for patients
who have had a primary malignant bone tumor of the distal part of the femur or
the proximal part of the tibia. The present study was performed to evaluate the
muscle activity, the kinetics (range of motion of the hip and knee joints), and
the kinematics (joint moments) after rotationplasty and to determine whether
there was an association between these parameters and the functional outcome.
METHODS: Forty-three patients who had been managed with rotationplasty for the
treatment of a femoral or tibial bone tumor were evaluated clinically and
functionally. The mean age (and standard deviation) at the time of follow-up was
24.4 +/- 10.7 years (range, eight to sixty-eight years), the mean age at the time
of the procedure was 17.8 +/- 10.2 years (range, seven to sixty-three years), and
the mean duration of follow-up was 6.7 +/- 4.9 years (range, 0.7 to eighteen
years). Instrumented gait and electromyographic analyses were performed. The
qualitative data were compared with the functional outcome, which was determined
with the functional evaluation score of the Musculoskeletal Tumor Society.
RESULTS: Gait analysis revealed a fairly normal walking pattern with a slight
limp and a lateral lean of the trunk over the ipsilateral limb that led to a
reduced joint moment in the hip (moment on involved side, 68 percent [compared
with a control group]; moment on uninvolved side, 81 percent). The ranges of
motion of the hips (uninvolved side, 42.0 +/- 8.2 degrees; involved side, 42.4 +/
8.0 degrees) and the knees (uninvolved side, 59.7 +/- 5.0 degrees; involved side
[former ankle joint], 58.1 +/- 11.6 degrees) were symmetrical even though the
knee-motion pattern of the involved limb indicated a slightly reduced extensor
mechanism in 51 percent (twenty-two) and a markedly reduced extensor mechanism in
35 percent (fifteen) of the forty-three patients. Electromyography revealed
function of the muscles of the involved limb, with comparable amplitudes in the
involved and uninvolved limbs. The leg muscles of the involved limb were active
in the stance phase (the soleus and the lateral and medial heads of the
gastrocnemius) and the swing phase (the peroneus longus and the tibialis
anterior) according to their function in relation to the new knee joint. The
patients had a good functional result, with a mean score of 23.9 +/- 2.7 of 30
points. With the numbers available for study, we could not show the duration of
follow-up to be related to the overall outcome, but the age at the time of the
operation was related to the total functional score as well as to gait and
walking ability (p < 0.05). CONCLUSIONS: The results of the electromyographic and
gait analyses demonstrated good functional restoration of gait following
rotationplasty.
PMID- 10682728
TI - Acetabular revision with use of a bilobed component inserted without cement in
patients who have acetabular bone-stock deficiency.
AB - BACKGROUND: Massive deficiency of acetabular bone stock is a challenging problem
in the increasing number of patients who need a revision of a failed hip
arthroplasty. The bilobed cup has been presented as one alternative
reconstruction technique for hips with extensive acetabular bone loss. The
purpose of this study was to assess the results with use of a bilobed acetabular
component inserted without cement for revision reconstruction in hips with
acetabular bone deficiency in order to clarify the indications for its use and to
identify the factors that influence the clinical and radiographic outcome.
METHODS: Forty-one hips in thirty-eight patients had an acetabular revision with
a bilobed acetabular component inserted without cement between December 1991 and
December 1995. These hips were a subset of the 414 hips treated with an
acetabular revision during the same period of time. One patient was lost to
follow-up, and one died during the study period. Two patients who could not
return for radiographic evaluation completed questionnaires. The remaining thirty
four patients (thirty-seven hips) were evaluated radiographically and clinically
and were followed for an average of forty-one months (range, twenty-four to sixty
six months). RESULTS: Radiographic analysis demonstrated an improvement in the
average vertical displacement of the hip center. At the time of the latest follow
up examination, 76 percent (twenty-eight) of the thirty-seven cups were stable, 8
percent (three) were probably unstable with a change in the screw position but no
definite migration of the cup, and 16 percent (six) were unstable. Eight of the
nine loose or probably loose components were in patients who had more than two
centimeters of superior migration of the component and disruption of Kohler's
line on preoperative radiographs. Additionally, implants were more likely to
become unstable (demonstrating more than 4 degrees of change in the abduction
angle or more than four millimeters of radiographic migration) when the inferior
aspect of the component did not extend to or distal to the interteardrop line,
which indicated that the component was undersized. CONCLUSIONS: On the basis of
our early rate of probable or definite loosening of 24 percent (nine of thirty
seven cups) and the technical difficulties involved, we do not recommend the
routine use of this component. We believe that this device is indicated when a
patient has an oblong-shaped acetabular defect and the surgeon wants to correct
an elevated hip center. However, the medial wall of the acetabulum (Kohler's
line) should be intact if the failed component has migrated more than two
centimeters. An alternative reconstruction technique, such as use of a structural
allograft with or without an acetabular cage, is also an option in this
situation.
PMID- 10682729
TI - Anticoagulant treatment of thromboembolism with intravenous heparin therapy in
the early postoperative period following total joint arthroplasty.
AB - BACKGROUND: Treatment of thromboembolism with intravenous heparin therapy in the
early postoperative period after total joint arthroplasty has been associated
with a high rate of complications. The purpose of the present study was to
compare the rate of bleeding complications in a group of patients who required
intravenous heparin therapy for the treatment of thromboembolism after total hip
or knee arthroplasty with the rate in a control group of patients who received
only prophylactic anticoagulation. METHODS: The postoperative courses of forty
four consecutive patients who were managed with intravenous administration of
heparin and oral administration of warfarin for the treatment of a thromboembolic
event following unilateral total hip or knee arthroplasty were compared with
those of a control group of 376 consecutive patients who had these same
procedures but did not have a thromboembolic complication. The patients in the
control group were managed with prophylactic anticoagulation with use of
enoxaparin. Sixty-eight percent (thirty) of the forty-four patients in the
heparin group received the initial dose of heparin on or before the fourth
postoperative day, and 82 percent (thirty-six) received an initial bolus of 5000
units of heparin at the initiation of therapy. RESULTS: The rate of bleeding
complications was 9 percent (four of forty-four) in the heparin group, compared
with 6 percent (twenty-three of 376) in the control group (p = 0.44). The mean
transfusion requirement in the heparin group (1.8 units of packed red blood
cells) was significantly greater than that in the control group (0.8 unit) (p <
0.0001). Three of the four patients who had a bleeding complication while
receiving heparin and warfarin had coagulation parameters that were substantially
higher than recommended levels. The mean duration of hospitalization in the
heparin group (fifteen days) was significantly longer than that in the control
group (seven days) (p < 0.0001). CONCLUSIONS: The results of the present study
suggest that the use of intravenous heparin therapy for the treatment of
thromboembolism in the early postoperative period after total joint arthroplasty
is associated with a rate of bleeding complications that is similar to that
associated with the use of prophylactic anticoagulation with use of enoxaparin
alone. One should expect an increased transfusion requirement and a longer
duration of hospitalization for patients who require intravenous heparin therapy
for the treatment of a thromboembolic event.
PMID- 10682730
TI - Bilateral stress fractures of the anterior part of the tibial cortex. A case
report.
PMID- 10682731
TI - A transverse acetabular nonunion treated with computer-assisted percutaneous
internal fixation. A case report.
PMID- 10682732
TI - Displaced intra-articular fractures of the calcaneus.
PMID- 10682733
TI - Recent advances in venous thromboembolic prophylaxis during and after total hip
replacement.
PMID- 10682734
TI - Design issues in clinical studies of the in vivo volumetric wear rate of
polyethylene bearing components.
PMID- 10682735
TI - Current concepts review. Internet resources for orthopaedic surgeons.
PMID- 10682736
TI - Survival analysis of hips treated with core decompression or vascularized fibular
grafting because of avascular necrosis.
PMID- 10682737
TI - Survival analysis of hips treated with core decompression or vascularized fibular
grafting because of avascular necrosis.
PMID- 10682738
TI - Survival analysis of hips treated with core decompression or vascularized fibular
grafting because of avascular necrosis.
PMID- 10682739
TI - Acetabular involvement in osteonecrosis of the femoral head.
PMID- 10682740
TI - Clinical and pathological findings of a newly recognized disease of elephants
caused by endotheliotropic herpesviruses.
AB - The unique clinical and pathological findings in nine Asian (Elephas maximus) and
two African (Loxodonta africana) elephants from North American Zoos with a highly
fatal disease caused by novel endotheliotropic herpesviruses are described.
Identification of the viruses by molecular techniques and some epidemiological
aspects of the disease were previously reported. Consensus primer polymerase
chain reaction (PCR) combined with sequencing yielded molecular evidence that
confirmed the presence of two novel but related herpesviruses associated with the
disease, one in Asian elephants and the second in African elephants. Disease
onset was acute, with lethargy, edema of the head and thoracic limbs, oral
ulceration and cyanosis of the tongue followed by death of most animals in 1 to 7
days. Pertinent laboratory findings in two of three clinically evaluated animals
included lymphocytopenia and thrombocytopenia. Two affected young Asian elephants
recovered after a 3 to 4 wk course of therapy with the anti-herpesvirus drug
famciclovir. Necropsy findings in the fatal cases included pericardial effusion
and extensive petechial hemorrhages in the heart and throughout the peritoneal
cavity, hepatomegaly, cyanosis of the tongue, intestinal hemorrhage, and
ulceration. Histologically, there were extensive microhemorrhages and edema
throughout the myocardium and mild, subacute myocarditis. Similar hemorrhagic
lesions with inflammation were evident in the tongue, liver, and large intestine.
Lesions in these target organs were accompanied by amphophilic to basophilic
intranuclear viral inclusion bodies in capillary endothelial cells. Transmission
electron microscopy of the endothelial inclusion bodies revealed 80 to 92 nm
diameter viral capsids consistent with herpesvirus morphology. The short course
of the herpesvirus infections, with sudden deaths in all but the two surviving
elephants, was ascribed to acute cardiac failure attributed to herpesvirus
induced capillary injury with extensive myocardial hemorrhage and edema.
PMID- 10682742
TI - Seroepidemiology of chlamydial infections of wild ruminants in Spain.
AB - Chlamydial infections were determined serologically among wild ruminants in the
Nature Park of the Sierras de Cazorla, Segura y Las Villas (CNP; Spain). Sampling
was done during the period from 1990-95. There were 1,244 blood samples
collected, consisting of 490 from fallow deer (Dama dama), 343 from mouflon (Ovis
mussimon), 283 from red deer (Cervus elaphus) and 128 from Spanish ibex (Capra
pyrenaica). Specific complement-fixing antibodies of Chlamydia spp. were detected
by means of microtechnique, using lipopolysaccharide antigen. The relationship of
biological (species, sex, age), temporal (year) and territorial (central and
peripheral areas) factors to seropositive prevalence was examined, and
preliminary data were collected on whether or not sheep and goat herds grazing in
the peripheral areas of the park also were infected with Chlamydia spp.
Chlamydiosis was common in the four species of wild ruminants in the CNP in all
the years studied. The prevalence of Chlamydia sp. in mouflon (37%) was
significantly greater than in fallow deer (30%), and both had a significantly
higher prevalence rate than Spanish ibex and red deer (both 24%). The four
species of wild ruminants were similar in that they act as reservoirs of
Chlamydia spp., although their receptivity may be different, and the infection
can certainly be maintained among these animals by intra-group transmission. The
differences in prevalences and geometric mean titers (GMT), both between the
sexes (male versus female) and between different ages (adult versus juvenile),
were insignificant in all four species. For all species of wild ruminants both
prevalence rates and GMTs were greater in populations occupying the peripheral
areas of the park than in those inhabiting the central area. Herds of sheep and
goats had a high prevalence of chlamydiosis. Intertransmission of Chlamydia sp.
between wild and domestic ruminants occurred through grazing on the same
pastures. The highest mean prevalence (44%) of patent infections (CFT titers of >
or =1:80) was detected in red deer, although this frequency was not significantly
different from those observed in mouflon (39%), Spanish ibex (38%), and fallow
deer (37%). The proportion of patent infection was higher in females than in
males, and none of the juveniles (<2-yr-old) showed patent infections. The
prevalence of predicted patent chlamydial infections was always higher in the
peripheral areas of the park, although only among mouflon and fallow deer were
the differences statistically significant.
PMID- 10682741
TI - Role of peridomestic birds in the transmission of St. Louis encephalitis virus in
southern California.
AB - In response to the 1984 St. Louis encephalitis (SLE) epidemic in the Los Angeles
Basin of southern California (USA), an investigative program was initiated to
evaluate the interactive components of the SLE virus transmission cycle. From
1987 through 1996 (10 yr), 52,589 birds were bled and their sera tested for SLE
and western equine encephalomyelitis (WEE) virus antibodies by the
hemagglutination inhibition (HAI) test. Eighty-three percent of the birds tested
were house finches (Carpodacus mexicanus) (48.7%) and house sparrows (Passer
domesticus) (34.6%); 1.1% of these birds were positive for SLE antibodies.
Prevalence of WEE antibodies was negligible. The analysis of 5,481 sera from rock
doves (Columbia livia) yielded 3.6% SLE positives and 0.4% WEE positives.
Collection sites were maintained as study sites when identified as positive bird,
mosquito, and SLE virus activity localities; others were abandoned. Serial serum
samples from 7,749 banded house sparrows and 9,428 banded house finches from
these selected sites demonstrated year-round SLE virus transmission. One location
exhibited significant numbers of house finches undergoing annual SLE
seroconversion and a number of seroconversion-reversion-reconversion sequences
suggesting either viral reinfection from mosquitoes or recrudescence by latent
virus. A proportion of both bird species also lived for longer than 1 yr, thus,
increasing the possibility of virus carry-over from autumn to spring. Assessment
of concurrently collected mosquitoes indicated no correlative association between
mosquito populations and SLE seroconversion and reconversion. European house
sparrows introduced in the 1800's may have provided a supplemental link to the
existing SLE virus enzootic cycle involving endemic house finches. Meteorological
factors are reviewed as possible important correlates of SLE epidemics. The house
finch/house sparrow serosurveillance system is also evaluated for use as an
"Early Warning" indicator of SLE virus activity.
PMID- 10682743
TI - Characterization of Lyme disease spirochetes isolated from ticks and vertebrates
in North Carolina.
AB - Borrelia burgdorferi isolates obtained from numerous locations and from different
hosts in North Carolina, were compared to previously characterized strains of the
Lyme disease spirochete and other Borrelia spp. The spirochete isolates were
confirmed to be B. burgdorferi sensu stricto based on immunofluorescence (IFA)
using a monoclonal antibody to outer surface protein A (Osp A [H5332]) and
polymerase chain reaction (PCR) using a species-specific nested primer for a
conserved region of the gene that encodes for flagellin. In addition, the
isolates tested positive in Western blots with species-specific monoclonal
antibodies for outer surface protein A and OspB (84c), and the genus-specific,
monoclonal antibody to flagellin (H9724). Infectivity studies with several of
these isolates were conducted using Mus musculus and Oryzomys palustris and the
isolates exhibited markedly different levels of infectivity. This study
demonstrates that B. burgdorferi sensu stricto is present and naturally
transmitted on the Outer Banks and in the Coastal Plain and Piedmont regions of
North Carolina.
PMID- 10682744
TI - Mange epizootic in white-nosed coatis in western Mexico.
AB - From November of 1994 to June of 1996 an epizootic of mange, probably caused by
the mite Notoedres cati, occurred in white-nosed coatis (Nasua narica) in the
tropical dry forests of the Chamela-Cuixmala Biosphere Reserve in western Mexico.
A monitoring scheme to determine the extent and severity of the epizootic within
coatis was implemented. Trapping periods and transects were conducted for 2 yr.
To control the spread of the disease, all captured infected coatis were either
euthanized or treated with acaricides such as Butox and Ivomec-F, depending on
the severity of their infection. Four other species of wild mammals and feral
cats had skin conditions resembling mange. A more severe problem with the disease
was predicted and later confirmed in the less isolated areas of the reserve, with
a higher density of coatis. Our results indicate that epizootics may be more
prone to occur in areas with greater fragmentation and less isolation from
anthropogenic influence. Interestingly, although there was an apparently severe
impact of the mange epizootic in the coati population, the long-term impact of
the disease is unknown but appears to be negligible. So in order to understand
the role of diseases in wildlife populations, long-term experimental studies are
required.
PMID- 10682745
TI - Trichomoniasis in a Bonelli's eagle population in Spain.
AB - During 1980-97, trichomoniasis was detected in nestlings of Bonelli's eagle
Hieraaetus fasciatus in Catalonia (Spain). In 1993 Trichomonas gallinae was
isolated in 36% of nestlings (n = 39) and affected 41% of broods (n = 22).
Overall, trichomoniasis was one of the most important single nestling mortality
factor, accounting for 22% of total chick mortality, and causing the death of 2%
of chicks. Trichomoniasis deaths took place during the second half of the
nestling period. The median age at death was 45.5 days. Although the presence of
the parasite was not related to the composition of the diet or parental age,
pairs that developed the disease ate more pigeons and included more often non
adult birds. At present trichomoniasis apparently has little demographic impact
on the Bonelli's eagle population in Catalonia, but the eventual spread of this
disease in chicks and its unknown effects on adults might be of concern.
PMID- 10682746
TI - Detection, identification, and correction of a bias in an epidemiological study.
AB - The relative lack of epidemiological studies of natural populations is partly due
to the difficulty of obtaining samples that are both large enough and
representative of the population. Here, we present the result of an
epidemiological study (December 1992-August 1995) of feline immunodeficiency
virus (FIV) in a free-roaming population of domestic cats (Felis catus), with a
special emphasis on sample bias. Over five trapping periods, the prevalence of
FIV in sampled cats steadily declined. Across these samples we consistently
achieved a very large sampling fraction (approximately 60% of the population),
the sex ratio, age and weight distributions remained stable with time in the
samples, and the sex ratio was similar in the samples and the population. These
indices would normally indicate that our samples were representative, suggesting
the decline in FIV prevalence to be real. However, a concomitant ecological study
of the whole population revealed an important bias in the samples, with an
initial high probability of capturing a few individuals, which appeared
significantly more likely to be FIV-infected, and then a lower probability of
recapturing them. Since our protocol resulted in a non-random sampling,
subsequent trappings were designed to avoid this bias, by also capturing
individuals who had previously learned to escape capture. This modified capture
regime revealed that FIV prevalence was in fact constant in the population. This
study shows how samples of large size, which are stable and appear representative
of the population, can still be biased. These results may have major implications
for other studies based on trapping.
PMID- 10682747
TI - Effects of delivery method on serological responses of bighorn sheep to a
multivalent Pasteurella haemolytica supernatant vaccine.
AB - The safety and efficacy of a remotely delivered multivalent Pasteurella
haemolytica supernatant vaccine (serotypes A2 and T10) were examined in captive
Rocky, Mountain bighorn sheep (Ovis canadensis canadensis). Twenty bighorn sheep
were grouped according to baseline leukotoxin neutralizing antibody titers (< or
=2 or >2 log2(-1)) and vaccination history (previously vaccinated or
unvaccinated). Within these groups, animals were randomly assigned to one of two
delivery treatments: hand injection (control) or biobullet implantation. All
bighorns received a single dose from the same lot of vaccine (n = 10/treatment);
four additional animals were injected intramuscularly with 0.9% saline as
unvaccinated sentinels. Mild, transient lameness one day after hand injection or
biobullet implantation was the only adverse effect. Serum neutralizing antibody
titers to P. haemolytica leukotoxin differed between delivery treatments (P =
0.009) and among baseline titer/vaccination history groups (P = 0.013).
Neutralizing titers were higher among hand-injected bighorns. Although
neutralizing titers were lower among implanted bighorns than hand-injected
controls at 1 wk (P = 0.002) and 2 wk (P = 0.021) after vaccination,
seroconversion rates in response to implantation (6/10) and hand injection (9/10)
did not differ (P = 0.303). Agglutinating antibody titers to T10 were high and
did not vary over time or between delivery treatments. Agglutinating antibody
titers to A2 in the hand-injected controls were not different (P > or = 0.07)
than those in bighorns vaccinated with biobullet implantation. These data
demonstrate that although hand injection elicits higher absolute titers,
biobullet implantation may also stimulate effective antibody responses to P.
haemolytica supernatant vaccine. Further evaluation of biobullet vaccination
against pneumonic pasteurellosis in free-ranging populations of wild bighorn
sheep is warranted.
PMID- 10682748
TI - A modified bait for oral delivery of biological agents to raccoons and feral
swine.
AB - A field study was conducted on Ossabaw Island (Georgia, USA) in March 1994 to
evaluate four different types of bait for delivering orally effective biological
agents to raccoons (Procyon lotor) and feral swine (Sus scrofa). A deep-fried
corndog batter bait, which was previously shown to be ingested by both captive
and free-ranging raccoons, and a polymer fishmeal bait which had been shown
effective for both raccoons and feral swine were compared with a grain-based dog
food meal polymer bait topically coated with corn oil and cornmeal or with fish
oil and fishmeal. Tracking stations were used to determine the number of each
bait type visited and removed by animals visiting stations. We found no
significant differences in the numbers of different baits removed by either
species. These data support the results of earlier studies which also indicated
that an inexpensive grain-based matrix bait surface-coated with attractive
flavors can be used to deliver oral biologics to problem species.
PMID- 10682749
TI - Effect of jaw shape in kill-traps on time to loss of palpebral reflexes in
brushtail possums.
AB - The effect of three configurations of the jaw of kill-traps on time to loss of
palpebral reflex of brushtail possums (Trichosurus vulpecula) was assessed. Traps
were Standard, with an offset rotating jaw closing past a pear-shaped
constriction, Offset, with a rotating jaw closing past a straight edge, and
Opposing, with a rotating jaw closing directly onto a static bar. Possums
captured in the Standard and Offset traps had significantly lower times to loss
of palpebral reflexes (42 and 50 sec respectively) than those captured in
Opposing traps (122 sec). Both the Standard and Offset traps achieved total
occlusion of both carotid arteries more frequently than the Opposing trap. Thus
the killing effectiveness of kill traps designed for capturing possums can be
improved by offsetting the jaws without the need to increase the power of the
trap. Therefore, for some target species, such modifications might satisfy the
demands of animal welfare proponents for traps that kill rapidly, without
compromising trapper safety.
PMID- 10682750
TI - Scurvy in capybaras bred in captivity in Argentine.
AB - In order to determine if the absence of vitamin C in the diet of capybaras
(Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals
were fed food pellets without ascorbic acid, while another group of eight
individuals received the same food with 1 g of ascorbic acid per animal per day.
Animals in the first group developed signs of scurvy-like gingivitis, breaking of
the incisors and death of one animal. Clinical signs appeared between 25 and 104
days from the beginning of the trial in all individuals. Growth rates of
individuals deprived of vitamin C was considerably less than those observed in
the control group. Deficiency of ascorbic acid had a severe effect on
reproduction of another population of captive capybaras. We found that the
decrease in ascorbic acid content in the diet affected pregnancy, especially
during the first stages. The results obtained suggest that it is necessary to
supply a suitable quantity of vitamin C in the diet of this species in captivity.
PMID- 10682752
TI - Influence of diet on the hematology and serum biochemistry of zinc-intoxicated
mallards.
AB - Changes in hematological and serum biochemistry parameters in female zinc (Zn)
dosed farm-raised mallards (Anas platyrhynchos) fed four different diets were
examined. Sixty ducks received an average dose of 0.97 g of Zn in the form of
eight, 3.30-mm diameter shot pellets containing 98% Zn and 2% tin, and another 60
ducks were sham-dosed as controls. Fifteen ducks from each of the two dosing
groups were assigned to one of four dietary treatments: corn only, corn with
soil, commercial duck ration only, or commercial duck ration with soil. Shot
pellet dissolution rates ranged from 7 mg/Zn/day to 27 mg/Zn/day. Regardless of
diet, the Zn dose resulted in mortality; incoordination; paralysis and anorexia;
decreased body, liver, pancreas, gonad, and gizzard weight; increased kidney
weight; and macroscopic lesions. Zn-dosed ducks had a lower mean erythrocyte
packed cell volume (PCV), higher mean reticulocyte count, and a greater number of
individuals with immature and/or abnormal erythrocytes, than did control
mallards. Mean total leucocyte counts were higher in Zn-dosed ducks than in
controls. Zn-dosed ducks that had soil available had higher leucocyte counts than
those without soil. Zn-dosed ducks were characterized by a marked heterophilia
and relative lymphopenia. In Zn-dosed ducks, the mean lymphocyte count was
highest in those provided a commercial duck ration, and lowest in those fed corn.
In control ducks, the mean lymphocyte count was highest in ducks fed corn, and
lowest in those provided soil along with a commercial duck ration. Zn-dosed
mallards had higher serum aspartate aminotransferase and amylase levels, and
lower alkaline phosphatase activities than control ducks. Serum phosphorus and
uric acid concentrations were higher, and calcium, glucose, and total protein
levels lower, in Zn-dosed ducks than in control ducks. Diet did affect serum
calcium, phosphorus, total protein, and uric acid concentrations. Differences in
erythrocyte and leucocyte parameters, serum enzyme activities, and metabolite
concentrations were associated with dose and diet effects. Diets high in protein
and other organic matter and calcium and phosphorus did not prevent or
substantially alleviate Zn toxicosis in farm-raised mallard ducks.
PMID- 10682751
TI - Biochemical responses to fibropapilloma and captivity in the green turtle.
AB - Blood biochemical parameters were compared for green turtles (Chelonia mydas)
with and without green turtle fibropapillomatosis (GTFP) from both captive and
wild populations in Hawaii (USA) and from a captive population from California
(USA), during the period between 1994 and 1996. Statistical analysis did not
detect an influence of disease in any of the blood parameters for free-ranging
turtles; however, captive turtles in Hawaii with GTFP had significantly higher
levels of alkaline phosphatase and significantly lower levels of lactate compared
to non-tumored captive turtles. Multivariate analysis found that biochemical
profiles could be used to accurately predict if turtles were healthy or afflicted
with GTFP. Discriminant function analysis correctly classified turtles as being
with or without GTFP in 89% of cases, suggesting that diseased animals had a
distinct signature of plasma biochemistries. Measurements of blood parameters
identified numerous differences between captive and wild green turtles in Hawaii.
Levels of corticosterone, lactate, triglyceride, glucose, and calcium were
significantly higher in wild green turtles as compared to captive turtles, while
uric acid levels were significantly lower in wild turtles as compared to captive
turtles. Additionally, turtles from Sea World of California (San Diego,
California, USA), which had been in captivity the longest, had higher levels of
alanine aminotransferase and triglycerides as compared to nearly all other
groups. Differences in diet, sampling methods, environmental conditions, and
turtle size, help to interpret these results.
PMID- 10682753
TI - Immobilization of California sea lions using medetomidine plus ketamine with and
without isoflurane and reversal with atipamezole.
AB - The use of medetomidine and ketamine, alone and in combination with isoflurane,
with atipamezole reversal was evaluated for immobilizing 51 California sea lions
(Zalophus californianus) for a variety of medical procedures at a rehabilitation
center in northern California (USA) between May 1997 and August 1998. Animals
were given 140 microg/kg medetomidine with 2.5 mg/kg ketamine intramuscularly.
Mean (+/-SD) time to maximal effect was 8+/-5 min. At the end of the procedure,
animals were given 200 microg/kg atipamezole intramuscularly. Immobilization and
recovery times were, respectively, 25+/-12 and 9+/-7 min for 35 animals
maintained with medetomidine and ketamine alone and 58+/-30 and 9+/-9 min for 16
animals intubated and maintained with isoflurane. No mortalities occurred as a
result of the immobilizations. Disadvantages of the medetomidine and ketamine
combination included a moderate variation in time to maximal effect and plane of
sedation, a large injection volume and high cost. However, this combination
offers safe and reversible immobilization that can be easily administered by the
intramuscular route and that produces a plane of anesthesia that is sufficient to
carry out most routine diagnostic procedures.
PMID- 10682755
TI - Pathology of experimental toxoplasmosis in eastern barred bandicoots in Tasmania.
AB - Wild-caught eastern barred bandicoots (Perameles gunnii) initially seronegative
to Toxoplasma gondii, were inoculated orally with approximately 100 T. gondii
oocysts. The bandicoots were maintained in indoor pens under laboratory
conditions and observed daily. Serial blood samples were tested for agglutinating
antibodies to T. gondii. Inoculated bandicoots died 15 and 17 days post
infection. A rise in Direct Agglutination Test (DAT) titres was detected at the
time of death (1:256, 1:64 respectively). Clinical observations, serological
changes, gross findings at necropsy, and histopathological changes were
consistent with acute toxoplasmosis. The findings indicate that eastern barred
bandicoots are likely to die from primary T. gondii infection, often even before
detectable antibodies are produced, reinforcing the significance of toxoplasmosis
as a potential contributor to the reduction in numbers of wild populations of
eastern barred bandicoots.
PMID- 10682754
TI - Immobilization of free-ranging nine-banded and great long-nosed armadillos with
three anesthetic combinations.
AB - Nine-banded (n = 47) and great (n = 31) long-nosed armadillos (Dasypus
novemcinctus and Dasypus kappleri) were immobilized for clinical examination and
collection of biological samples as part of a wildlife rescue during the filling
of a hydroelectric dam (Petit Saut, French Guiana) from May 1994 to April 1995.
Three intramuscular (i.m.) anesthetic combinations were evaluated: (1)
tiletamine/zolazepam (T/Z) at a dose of 8.5 mg/kg in 12 nine-banded long-nosed
armadillos (NBA) and 10 great long-nosed armadillos (GLA), (2) ketamine at 40
mg/kg combined with xylazine at 1.0 mg/kg (K/X) in 18 NBA and nine GLA, and (3)
ketamine at 7.5 mg/kg combined with medetomidine at 75 microng/kg (K/M) in 17 NBA
and 12 GLA, antagonized by 375 microg/kg atipamezole. Induction was smooth,
ranged from mean +/- SD = 2.8+/-0.6 to 4.3+/-1.8 min, and did not differ
significantly between protocols, species, or sex. In NBA, immobilization time
ranged from 43.8+/-27.8 to 66.5+/-40.0 min and did not differ between protocols
or sex. Muscle relaxation was judged to be better with K/X and K/M versus T/Z. In
GLA, the response to the anesthetic protocols was more variable and
immobilization time ranged from 30.4+/-6.2 to 98.4+/-33.7 min. The main
difference was observed in GLA females receiving the T/Z combination, in which
immobilization time was significantly longer versus males, but also versus GLA
K/M group, and versus NBA T/Z group. Effects on body temperature, heart rate and
respiratory rate were limited. Thirty six to 50% of the individuals showed
hypoxemia (SpO2 < 85%) throughout anesthesia and values <80% also were recorded
but the hypoxemia was not associated with clinical signs. With T/Z and K/X,
recovery was irregular and prolonged up to 2 to 3 hr in some individuals. In K/M
groups, first standing was observed 1.0 to 16.4 min after i.m. atipamezole
injection without adverse effects. Finally, the three anesthetic combinations
used in this study were effective and safe agents for 30 to 40 min
immobilizations including minor surgery procedures. The ability to antagonize the
medetomidine-induced sedation with atipamezole significantly reduces the recovery
time, making the K/M combination preferable, especially in field conditions.
PMID- 10682756
TI - Earthworms as paratenic hosts of toxoplasmosis in eastern barred bandicoots in
Tasmania.
AB - An experimental feeding study was designed to assess the role of earthworms in
the transmission of Toxoplasma gondii infection to eastern barred bandicoots
(Perameles gunnii). Six animals with no agglutinating antibodies to T. gondii
were fed artificially cultured earthworms that had been maintained in autoclaved
nutrient-enriched soil. Two animals were given earthworms that had been
maintained in soil contaminated with T. gondii oocysts (P89/VEG strain); two
animals were fed on earthworms, which initially had been exposed to soil
containing T. gondii oocysts then transferred through three changes of sterile
soil; two control bandicoots were fed earthworms maintained in sterile soil. Both
bandicoots fed earthworms maintained in T. gondii contaminated soil died 11 and
14 days after feeding. The necropsy findings were consistent with acute
toxoplasmosis. Bandicoots fed earthworms exposed to oocysts but then transferred
through changes of sterilized soil remained healthy as did control animals. All
surviving animals remained seronegative over the 6 wk observation period after
feeding. These findings confirm that earthworms, a major component of the natural
diet of P. gunnii, can transmit T. gondii infection. It appears that oocysts
present in the alimentary tracts of the worms, rather than infective stages of T.
gondii in worm somatic tissues, are responsible for these infections.
PMID- 10682757
TI - Naturally occurring and experimentally transmitted Hepatozoon americanum in
coyotes from Oklahoma.
AB - Twenty free-ranging coyotes (Canis latrans) in Oklahoma (USA) were examined for
the presence of naturally occurring infections with Hepatozoon americanum and to
determine if bone lesions attributable to H. americanum were present. Although
eight of the 20 free-ranging coyotes were found to be naturally infected with H.
americanum, no bone lesions were detected. In addition, two coyote pups were
exposed to H. americanum oocysts collected from experimentally infected ticks and
the course of the resulting infection was followed. Both experimentally infected
coyotes developed hepatozoonosis detectable by specific muscle lesions beginning
4 wk after exposure. Bone lesions were detected grossly and histologically at
necropsy. Histologic evidence of periosteal bone proliferation ranged from
segmental areas of plump hypercellularity and thickening of the periosteum, with
minor degrees of osteogenesis, to extensive proliferation of woven bone and
periosteal hypercellularity and thickening. Nymphal Amblyomma maculatum that fed
on one of the experimentally infected coyote pups became infected and mature H.
americanum oocysts were recovered when the ticks molted to adults. These results
demonstrate that coyotes in some parts of Oklahoma are naturally infected with H.
americanum, that experimentally infected coyotes can develop clinical disease,
including characteristic bone lesions, and that A. maculatum nymphs can acquire
infections by feeding on them.
PMID- 10682758
TI - Louse flies on birds of Baja California.
AB - Louse flies were collected from 401 birds of 32 species captured in autumn of
1996 in Baja California Sur (Mexico). Only one louse fly species (Microlynchia
pusilla) was found. It occurred in four of the 164 common ground doves (Columbina
passerina) collected. This is a new a host species for this louse fly.
PMID- 10682759
TI - Prevalence of Bartonella henselae antibody in Florida panthers.
AB - Serum samples from 28 free-ranging Florida panthers (Puma concolor coryi) and
seven mountain lions from Texas (P. concolor stanleyana) living in south Florida
(USA) between 1997 to 1998 were tested for antibodies to Bartonella henselae.
Twenty percent (7/35) of the samples were reactive to B. henselae antisera with a
subspecies prevalence of 18% (5/ 28) for Florida panthers and 28% (2/7) for
cougars from Texas (USA). There was not a significant sex related difference in
infection rates among the Florida panthers. Antibody prevalence was higher in
panthers <2-yr of age (40%) compared to panthers >2-yr (13%). Compared to studies
of antibody prevalence in mountain lions (P. concolor) from California (USA),
overall seroprevalence was lower as was prevalence in panthers >2-yr-old.
However, the seroprevalence in animals <2-yr from southern Florida was similar to
prevalences reported in mountain lions or domestic felids in California.
PMID- 10682760
TI - Antibodies to selected disease agents in translocated wild turkeys in California.
AB - Wild turkeys (Meleagris gallopavo) trapped within California (n = 715) or
imported into California from other states (n = 381) from 1986 to 1996 were
tested for exposure to certain disease agents. Prevalence of antibody to
Mycoplasma gallisepticum, Mycoplasma meleagridis, Salmonella pullorum, Salmonella
typhimurium, Newcastle disease virus, and avian influenza virus was low (0-4%)
for wild turkeys trapped within California. With the exception of antibody
prevalence to M. meleagridis of 33%, the same was true for wild turkeys imported
into California from other states. Antibody prevalence to Mycoplasma synoviae was
8-10% for both groups.
PMID- 10682761
TI - Typing of pestiviruses from eland in Zimbabwe.
AB - Pestiviruses were isolated from three eland (Taurotragus oryx) in Zimbabwe. The
viruses were characterised by typing with monoclonal antibodies and by partial
genetic sequencing. All were similar to bovine viral diarrhea viruses commonly
isolated from cattle. This suggests that bovine viral diarrhea virus can spread
from cattle to eland.
PMID- 10682762
TI - Rabies in an American bison from North Dakota.
AB - In North Dakota (USA) during April 1998, a ranched female bison (Bison bison) was
found dead. At gross necropsy, there was profound hair loss and consolidated lung
lobes. Intracytoplasmic neuronal inclusions suggestive of Negri bodies were
observed in the brain stem and hippocampus, and a diagnosis of rabies was
confirmed by the fluorescent antibody test. Antigenic typing demonstrated the
occurrence of a rabies virus variant associated with skunks from the upper
midwestern USA. This case of a rabid bison was one of only four such instances
recorded from the USA over the past 40 yr, and is the first case report of rabies
in a bison that reports clinical, pathologic, and antigenic findings. Although
rabies in bison is rare, veterinarians and wildlife managers that work closely
with such non-traditional species are reminded of the dangers that zoonoses such
as rabies present.
PMID- 10682763
TI - Effect of climate and type of storage container on aflatoxin production in corn
and its associated risks to wildlife species.
AB - The effects of grain storage containers on aflatoxin production, and the
relationship between the level of aflatoxin and the number and weight of
fluorescing kernels were determined in corn (Zea maize) stored in controlled
climate regimes. Two hundred and forty 100-g samples were held up to 3 mos using
four types of storage containers placed in four climates. Storage containers
included corn placed in metal cans, paper bags, plastic bags, and paper bags
placed in plastic bags. Climates were constant during the duration of the project
and included a combination of temperatures and humidities. Temperatures were 29
32 C and 14-18 C; relative humidities were 85-88% and 35-40%. In addition, corn
was exposed to environmental conditions conductive for aflatoxin production and
100 g samples were randomly collected, examined under ultraviolet light for
fluorescence, and then quantified for aflatoxin levels. Corn samples tested
negative for aflatoxin at the beginning of the project. Main (i.e., container,
climate, and month) and interactive effects were not observed. Mean levels of
aflatoxin ranged from 0 to 151 microg/kg. Aflatoxin was produced regardless of
type of storage container, time of storage, and climatic conditions; however,
only 8% of the samples produced aflatoxin levels that exceeded 50 microg/kg.
Fluorescing corn ranged from 0 to 19 kernels per sample, while aflatoxin levels
ranged from 0 to 1,375 microg/kg for the same samples. No relationships were
found between the number and weight of fluorescing kernels of corn and aflatoxin
levels. The black light test yielded a false negative rate of 23% when in fact
the aflatoxin concentrations exceeded 50 microg/kg. Therefore, quantifying
fluorescing grain under UV light should not be considered a feasible alternative
for aflatoxin testing of grain intended for wildlife.
PMID- 10682764
TI - Lead poisoning in a northern bobwhite in Georgia.
AB - A northern bobwhite (Colinus virginianus) was observed with partial paralysis on
3 March 1997 and found dead on 8 March 1997 on Di-Lane Plantation Wildlife
Management Area (Burke County, Georgia, USA). The juvenile male was necropsied by
the Southeastern Cooperative Wildlife Disease Study (Athens, Georgia) and
diagnosed with lead toxicosis. The bobwhite had liver tissue lead levels of 399
parts per million wet weight and two worn 1-mm diameter lead shot pellets were
found in the gizzard.
PMID- 10682765
TI - Desert bighorn sheep mortality due to presumptive type C botulism in California.
AB - During a routine telemetry flight of the Mojave Desert (California, USA) in
August 1995, mortality signals were detected from two of 12 radio-collared female
desert bighorn sheep (Ovis canadensis) in the vicinity of Old Dad Peak in San
Bernardino County (California). A series of field investigations determined that
at least 45 bighorn sheep had died near two artificial water catchments
(guzzlers), including 13 bighorn sheep which had presumably drowned in a guzzler
tank. Samples from water contaminated by decomposing bighorn sheep carcasses and
hemolyzed blood from a fresh bighorn sheep carcass were tested for the presence
of pesticides, heavy metals, strychnine, blue-green algae, Clostridium botulinum
toxin, ethylene glycol, nitrates, nitrites, sodium, and salts. Mouse bioassay and
enzyme-linked immunosorbent assay detected type C botulinum toxin in the
hemolyzed blood and in fly larvae and pupae. This, coupled with negative results
from other analyses, led us to conclude that type C botulinum poisoning was most
likely responsible for the mortality of bighorn sheep outside the guzzler tank.
PMID- 10682766
TI - Letter to the editor concerning Arnold-Chiari malformation in a captive African
lion cub.
PMID- 10682767
TI - Double pylorus sign.
PMID- 10682768
TI - Minimally invasive treatment of malignant hepatic tumors: at the threshold of a
major breakthrough.
AB - Six existing minimally invasive techniques for the treatment of primary and
secondary malignant hepatic tumors--radio-frequency ablation, microwave ablation,
laser ablation, cryoablation, ethanol ablation, and chemoembolization--are
reviewed and debated by noted authorities from six institutions from around the
world. All of the authors currently believe that surgery remains the treatment of
choice for patients with resectable hepatic tumors. However, the clinical results
of each of the minimally invasive techniques presented have exceeded those
obtained with conventional chemotherapy or radiation therapy. Thus, for
nonsurgical patients, these techniques are becoming standard independent or
adjuvant therapies. In addition, with continued improvement in technology and
increasing clinical experience, one or more of these minimally invasive
techniques may soon challenge surgical resection as the treatment of choice for
patients with limited hepatic tumor.
PMID- 10682769
TI - CT and MR imaging findings of bowel ischemia from various primary causes.
AB - Ischemic bowel disease represents a broad spectrum of diseases with various
clinical and radiologic manifestations, which range from localized transient
ischemia to catastrophic necrosis of the gastrointestinal tract. The primary
causes of insufficient blood flow to the intestine are diverse and include
thromboembolism, nonocclusive causes, bowel obstruction, neoplasms, vasculitis,
abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive
injury. Computed tomography (CT) or magnetic resonance (MR) imaging can
demonstrate the ischemic bowel segment and may be helpful in determining the
primary cause. The CT and MR imaging findings include bowel wall thickening with
or without the target sign, intramural pneumatosis, mesenteric or portal venous
gas, and mesenteric arterial or venous thromboembolism. Other CT findings include
engorgement of mesenteric veins and mesenteric edema, lack of bowel wall
enhancement, increased enhancement of the thickened bowel wall, bowel
obstruction, and infarction of other abdominal organs. However, regardless of the
primary cause, the imaging findings of bowel ischemia are similar. Furthermore,
the bowel changes simulate inflammatory or neoplastic conditions. Understanding
the pathogenesis of various conditions leading to mesenteric ischemia helps the
radiologist recognize ischemic bowel disease and avoid delayed diagnosis,
unnecessary surgery, or less than optimal management.
PMID- 10682770
TI - Solitary pulmonary nodules: Part I. Morphologic evaluation for differentiation of
benign and malignant lesions.
AB - The solitary pulmonary nodule is a common radiologic abnormality that is often
detected incidentally. Although most solitary pulmonary nodules have benign
causes, many represent stage I lung cancers and must be distinguished from benign
nodules in an expeditious and cost-effective manner. Evaluation of specific
morphologic features of a solitary pulmonary nodule with conventional imaging
techniques can help differentiate benign from malignant nodules and obviate
further costly assessment. Small size and smooth, well-defined margins are
suggestive of but not diagnostic for benignity. Lobulated contour as well as an
irregular or spiculated margin with distortion of adjacent vessels are typically
associated with malignancy. There is considerable overlap in the internal
characteristics (eg, attenuation, cavitation, wall thickness) of benign and
malignant nodules. The presence of intranodular fat is a reliable indicator of a
hamartoma. The presence and pattern of calcification can also help differentiate
benign from malignant nodules. Computed tomography (CT) (particularly thin
section CT) is 10-20 times more sensitive than standard radiography and allows
objective, quantitative assessment of calcification. Initial evaluation often
results in nonspecific findings, in which case nodules are classified as
indeterminate and require further evaluation to exclude malignancy. Growth rate
assessment, Bayesian analysis, contrast material-enhanced CT, positron emission
tomography, and transthoracic needle aspiration biopsy can be useful in this
regard.
PMID- 10682771
TI - Solitary pulmonary nodules: Part II. Evaluation of the indeterminate nodule.
AB - Various strategies may be used to evaluate indeterminate solitary pulmonary
nodules. Growth rate assessment is an important and cost-effective step in the
evaluation of these nodules. Clinical features (eg, patient age, history of prior
malignancy, presenting symptoms, smoking history) can be useful in suggesting the
diagnosis and aiding in management planning. Bayesian analysis allows more
precise determination of the probability of malignancy (pCa). Decision analysis
models suggest that the most cost-effective management strategy depends on the
pCa for a given nodule. At contrast material-enhanced computed tomography,
nodular enhancement of less than 15 HU is strongly predictive of a benign lesion,
whereas enhancement of more than 20 HU typically indicates malignancy. At 2
[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography, lesions
with low FDG uptake are typically benign, whereas those with increased FDG uptake
are typically malignant. Results of transthoracic needle aspiration biopsy
influence management in approximately 50% of cases and, in indeterminate lesions
with a pCa between 0.05 and 0.6, is the best initial diagnostic procedure. It is
optimally used in peripheral nodules and has been reported to establish a benign
diagnosis in up to 91% of cases. Although there is no one correct management
approach, the ability to distinguish benign from malignant solitary pulmonary
lesions has improved with the use of these strategies.
PMID- 10682772
TI - Unusual radiologic findings in the thorax after radiation therapy.
AB - Radiation therapy is used to treat many intrathoracic and chest wall
malignancies. A variety of changes may occur after radiation therapy to the
thorax. Radiation therapy produces dramatic effects in the lung. Pulmonary
necrosis is an uncommon, severe, late complication of adjuvant postoperative
radiation therapy. Bronchiolitis obliterans with organizing pneumonia is a
distinct clinicopathologic entity characterized by patchy, migratory, peripheral
air-space infiltrates. Radiation therapy can also cause spontaneous pneumothorax,
mesothelioma, and lung cancer. In the mediastinum, radiation therapy may cause
thymic cysts, calcified lymph nodes, and esophageal injuries. Cardiovascular
complications of radiation therapy are often delayed and insidious. Premature
coronary artery stenosis occurs after radiation therapy to the mediastinum.
Radiation therapy may also give rise to calcifications of the ascending aorta,
pericardial disease, valvular injuries, and conduction abnormalities. Women who
undergo thoracic irradiation before the age of 30 years have a high risk of
developing a second breast cancer. Radiation-induced sarcomas are an infrequent
but well-recognized complication of radiation therapy. Other chest wall injuries
due to radiation therapy are osteochondroma and rib or clavicle fractures.
Knowledge of the imaging features of injuries caused by radiation therapy can
prevent misinterpretation as recurrent tumor and may facilitate further
treatment.
PMID- 10682773
TI - Back to basics: keeping patients and families in the loop.
PMID- 10682774
TI - Radiation-induced lung disease and the impact of radiation methods on imaging
features.
AB - Although radiologic findings in radiation-induced lung disease are well described
in the literature, the influence exerted on these findings by different radiation
methods is not well understood. Radiation treatment of non-small cell lung cancer
varies depending on the location and extent of disease. Irradiation with oblique
beam angles results in unusual distribution of radiation-induced lung disease.
Small cell lung cancer is treated with irradiation concurrent with or following
chemotherapy, and portal arrangements are controversial. In breast cancer, use of
tangential beam portals may induce radiation pneumonitis or fibrosis at the
peripheral lung anterolaterally. Use of supraclavicular portals may produce
lesions in the lung apex that appear similar to pulmonary tuberculosis. In
esophageal cancer, radiation portals with a 5-6-cm margin above and below the
tumor are generally recommended, and computed tomography (CT) frequently
demonstrates radiation-related lung damage adjacent to the mediastinum. In
mediastinal tumors, the mantle field includes all the major lymph node regions
above the diaphragm. Radiation pneumonitis varies from minimal to extremely
marked change in the paramediastinal areas and in both apices. CT is more
sensitive to radiation-induced lung disease than chest radiography and
demonstrates related changes earlier. Furthermore, it more clearly depicts the
precise distribution and pattern of disease. Familiarity with the imaging
findings in radiation-induced lung disease produced by different radiation
methods will help radiologists interpret abnormalities seen at chest radiography
and CT in affected patients.
PMID- 10682775
TI - Review of criteria appropriate for a very low probability of pulmonary embolism
on ventilation-perfusion lung scans: a position paper.
AB - The "low-probability" interpretation of ventilation-perfusion lung scans has been
characterized as misleading or even dangerous because of the high prevalence of
pulmonary embolism associated with such an interpretation. Since the completion
of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study,
analyses of the PIOPED database have allowed identification of several
abnormalities seen on ventilation-perfusion scans that have a positive predictive
value (PPV) for pulmonary embolism of less than 10%. These include nonsegmental
perfusion abnormalities (PPV = 8%), perfusion defects smaller than the
corresponding areas of increased opacity at chest radiography (PPV = 8%), matched
ventilation-perfusion abnormalities in two or three zones of a single lung (PPV =
3%), one to three small segmental perfusion defects (PPV = 1%), triple matched
defects in the upper or middle lung zone (PPV = 4%), and the stripe sign (PPV =
7%). Use of these abnormalities as interpretative criteria constitutes "very low
probability" interpretation and will reduce the number of low-probability
interpretations of ventilation-perfusion lung scans, which may be considered
nondiagnostic because of the unacceptably high rate of false-negative results.
This will enhance the utility of the ventilation-perfusion lung scan for
screening patients with suspected pulmonary embolism.
PMID- 10682776
TI - MR angiography of the thoracic aorta with an electrocardiographically triggered
breath-hold contrast-enhanced sequence.
AB - An electrocardiographically (ECG) triggered breath-hold contrast material
enhanced magnetic resonance (MR) angiography sequence has been developed for
imaging the thoracic aorta. A three-dimensional (3D) gradient-echo sequence is
used with a contrast material bolus. Forty-nine patients with various aortic
abnormalities and five healthy volunteers underwent imaging with the sequence.
All studies were performed in a single breath hold. ECG-triggered breath-hold
contrast-enhanced MR angiography was tolerated in 48 of the 49 patients. The
images demonstrated no respiratory motion artifacts and diminished pulsation
artifacts. The cardiac chambers, aortic root, ascending and descending aorta,
aortic arch, proximal arch vessels, and proximal coronary arteries were clearly
demonstrated and not obscured by ghost artifacts. The 3D data set allowed
excellent multiplanar reformation, permitting orthogonal or oblique views of the
vascular anatomy. A variety of congenital and acquired abnormalities were clearly
identified. When this sequence is used, it is important to evaluate both the
maximum-intensity projection and source images. Delayed imaging should be
performed to detect late filling. In conjunction with cine MR and T1-weighted
spin-echo imaging, ECG-triggered breath-hold contrast-enhanced MR angiography
should be considered the technique of choice for imaging the thoracic aorta.
PMID- 10682777
TI - Optimized diagnostic angiography in high-risk patients with severe peripheral
vascular disease.
AB - Conventional arteriography remains the usual method for preoperative assessment
of severe peripheral vascular disease (PVD). Unfortunately, many peripheral
arteriograms are still performed with a suboptimal technique, which can cause
significant diagnostic errors in patients with severe PVD. A suboptimal technique
may be due to poor collimation (causing incorrect exposure and incorrect gray
scale), excessive patient-film distance (magnification unsharpness), inadequate
volume or density of contrast material, poor contrast resolution (screen-film
arteriography), nonselective injection, patient movement, and pressure from
restraints or incorrect patient position (failure to profile lesions, pseudo
occlusion from external pressure or plantar flexion). The technique of selective
digital subtraction arteriography (DSA) allows one to avoid these errors. The
superior contrast resolution of DSA allows use of lower concentrations of
contrast material. Selective injection into the external iliac artery allows
proper positioning and improves image quality. Demonstration of distal vessels is
best achieved by using biplane arteriography. For patients with severe resting
ischemia, especially those with diabetes, high-quality selective DSA is essential
to ensure that all distal vessels suitable for distal bypass grafting are
identified. When properly performed, selective DSA remains the investigation of
choice for reliably demonstrating arterial anatomy in high-risk patients with
severe PVD.
PMID- 10682778
TI - Dynamic subtraction contrast-enhanced MR angiography: technique, clinical
applications, and pitfalls.
AB - Rapid advances in techniques of contrast material-enhanced magnetic resonance
(MR) angiography have enabled evaluation of the entire aorta and the main
arteries. Dynamic subtraction MR angiography consists of first-pass imaging of
long segments of arteries by using a three-dimensional fast field echo sequence
with multiple rapid bolus injections of a small dose of gadopentetate
dimeglumine. Subtraction enables clear demonstration of the enhanced vascular
lumen by eliminating background signal. Improved temporal resolution and repeated
sequences after gadopentetate dimeglumine administration allow demonstration of
arteries and veins separately. Double subtraction postprocessing can be used to
eliminate arterial enhancement in demonstration of the portal and systemic veins.
Additional postprocessing can be used to demonstrate arteries in a single image
in patients with aortic dissection or a prolonged circulation time. To optimize
the examination, the pulse sequence, injection dose, injection rate, timing of
the start of data acquisition, imaging time, breath holding, section thickness,
and coil selection should be considered. This technique is flexible enough to be
applied in a variety of clinical settings, including atherosclerotic occlusive
disease, aneurysm of aortoiliac arteries, bypass graft, Takayasu arteritis,
aortic dissection, antiphospholipid antibody syndrome, renal artery disease,
pelvic vascular disease, and the portomesenteric venous system.
PMID- 10682779
TI - Pediatric voiding cystourethrography: a pictorial guide.
AB - Voiding cystourethrography is commonly performed in children with prenatally
diagnosed hydronephrosis, urinary tract infections, and voiding abnormalities.
Voiding cystourethrography can be performed with many variations designed to
optimize visualization of disease and minimize radiation exposure. The procedure
should include assessment of the spine and pelvis; masses or opaque calculi;
bladder capacity, contour, and emptying capability; presence and grade of reflux;
and urethral appearance. Radiologists differ as to whether the patient should
void prior to catheterization. Anteroposterior imaging of the bladder is
performed during early filling; little or no imaging is necessary during
intermediate filling. When bladder filling is complete, steep oblique images that
are centered on the ureterovesical junction should be obtained. If reflux is
observed, the ipsilateral renal fossa may be imaged prior to voiding. With a
smaller than expected voiding volume, bladder refilling is recommended. Voiding
around the catheter is also strongly recommended. In girls, one anteroposterior
image of the urethra is usually sufficient; in boys, the entire urethra must be
imaged. Steep oblique imaging is optimal. At the conclusion of voiding, each
renal fossa should be imaged to detect reflux missed at fluoroscopy as well as
other anomalies. Familiarity with these abnormalities and use of proper
techniques will allow detection of most common pathologic conditions with very
low radiation exposure.
PMID- 10682780
TI - US approach to jaundice in infants and children.
AB - High-resolution real-time ultrasonography (US) serves as an important tool for
differentiation of obstructive and nonobstructive causes of jaundice in infants
and children, independent of liver function. Unconjugated hyperbilirubinemia
occurs in approximately 60% of normal term infants and in 80% of preterm infants.
Persistence of neonatal jaundice beyond 2 weeks of age demands US evaluation to
differentiate between the three most common causes: hepatitis, biliary atresia,
and choledochal cyst. In all three conditions, the hepatic echotexture is
diffusely coarse and hyperechoic, but this appearance may be seen in a variety of
hepatic inflammatory, obstructive, and metabolic processes. Thus, hepatic
scintigraphy and at times percutaneous liver biopsy are necessary to narrow the
differential diagnosis and to identify patients who require more invasive
techniques (eg, intraoperative cholangiography). US is useful for demonstrating
inspissated bile and biliary duct stones. In infants, stones are usually
secondary to obstructive congenital anomalies of the biliary tract, total
parenteral nutrition, furosemide treatment, phototherapy, dehydration, infection,
hemolytic anemia, and short-gut syndrome, whereas in older children, stones are
usually associated with sickle cell disease, bowel resection, hemolytic anemia,
and choledochal cyst. Jaundice in infants and children may also be due to
cirrhosis, benign strictures, and neoplastic processes.
PMID- 10682781
TI - Renal lymphoma: CT patterns with emphasis on helical CT.
AB - Renal lymphoma is most often seen in conjunction with multisystemic, disseminated
lymphoma or as tumor recurrence. Renal lymphoma may also be seen in
immunocompromised patients or, rarely, as primary disease. Computed tomography
(CT) is the most sensitive, efficient, and comprehensive examination for
evaluation of the kidneys in patients with suspected renal lymphoma. Helical CT
in particular improves detection and characterization of lymphomatous renal
involvement by optimizing contrast dynamics and data acquisition and is the
current modality of choice for accurate staging of lymphoma. Typical CT patterns
in renal lymphoma include single and multiple masses, invasion from contiguous
retroperitoneal disease, perirenal disease, and diffuse renal infiltration.
Atypical CT patterns may also be encountered and provide a diagnostic challenge.
These include spontaneous hemorrhage, necrosis, heterogeneous attenuation, cystic
transformation, and calcification. Solid renal masses including renal cell
carcinoma and metastases are the most commonly encountered entities that mimic
renal lymphoma at CT and require biopsy for definitive diagnosis. CT
(particularly helical CT) is useful in the evaluation of patients with suspected
renal lymphoma, and familiarity with the spectrum of findings in renal lymphoma
is important for accurate diagnosis.
PMID- 10682782
TI - From the archives of the AFIP. Infiltrative renal lesions: radiologic-pathologic
correlation. Armed Forces Institute of Pathology.
AB - Most renal masses exhibit an expansile growth pattern characterized by radial
tumor enlargement that displaces normal renal parenchyma and forms spherical,
often exophytic, lesions. These expansile masses have pushing margins that
impress adjacent normal renal parenchyma but do not infiltrate it; this behavior
results in a well-defined, encapsulated appearance at both radiologic and gross
pathologic examination. In contrast, certain disease processes involve the kidney
in an infiltrative fashion by using the normal renal architecture as scaffolding
for interstitial growth. These infiltrative renal lesions lack a sharp border of
demarcation with the normal parenchyma and therefore demonstrate ill-defined
zones of transition between the lesion and normal parenchyma. Although
infiltrative lesions frequently enlarge the kidney, its reniform shape is usually
maintained. Cross-sectional imaging can often help distinguish infiltrative from
expansile growth patterns through analysis of the parenchymal interface between
the process and the kidney, the effect of the lesion on the collecting system and
renal sinus, and the overall renal morphology. A wide variety of neoplastic and
inflammatory conditions characteristically involve the kidney by cellular
infiltration. Although considerable overlap of the imaging features exists among
the various infiltrative processes, the correct diagnosis may be suspected when
the clinical data and associated radiologic findings are considered together.
PMID- 10682783
TI - Image interpretation session: 1999. Intraductal mucin-producing tumor of the
pancreas.
PMID- 10682784
TI - Image interpretation session: 1999. Juxtaglomerular tumor.
PMID- 10682785
TI - Image interpretation session: 1999. Bilateral quadriceps tendon rupture and
multiple brown tumors in a patient with secondary hyperparathyroidism.
PMID- 10682786
TI - Image interpretation session: 1999. Accessory cardiac bronchus.
PMID- 10682787
TI - Image interpretation session: 1999. Extramedullary hematopoiesis in a patient
with beta thalassemia.
PMID- 10682788
TI - Image interpretation session: 1999. Benign mucous membrane pemphigoid
(cicatricial pemphigoid).
PMID- 10682789
TI - Image interpretation session: 1999. Leiomyosarcoma of the left renal vein.
PMID- 10682790
TI - Image interpretation session: 1999. Intraosseous malignant peripheral nerve
sheath tumor (malignant schwannoma) in a patient with neurofibromatosis.
PMID- 10682791
TI - Image interpretation session: 1999. Inflammatory myoblastic pseudotumor of the
trachea (plasma cell granuloma).
PMID- 10682792
TI - Image interpretation session: 1999. Desmoplastic infantile ganglioglioma.
PMID- 10682793
TI - The visible man: three-dimensional interactive musculoskeletal anatomic atlas of
the lower extremity.
AB - A personal computer-based interactive musculoskeletal anatomic atlas of the lower
extremity has been created by using the Visible Human Male data set. A
semiautomatic segmentation program was developed by using an intelligent scissors
approach and shape-based interpolation, thus considerably reducing the laborious
work of the segmentation and labeling process. Manual contour extractions at 3-mm
section intervals and shape-based interpolations of intervening sections of the
musculoskeletal structures of the lower extremity were performed. For interactive
and realistic three-dimensional display, an efficient binary volume rendering
method was developed that introduces the concept of shear-warp factorization and
applies a newly developed normal calculation technique. Binary volume rendering
reconstructs various structures from a series of two-dimensional sections in a
few seconds, thus enabling real-time manipulations of the computerized atlas. All
of the muscles, tendons, and bones of the lower extremity have been segmented and
labeled. The volume-based three-dimensional interactive atlas supports various
interactions including rotation, removal, highlighting with artificial colors,
arbitrary cutting operation, transparent view, and descriptive knowledge
representation. In addition, browsing through the two-dimensional images of
transverse, coronal, and sagittal views with labeling and segmentation
information is possible.
PMID- 10682794
TI - Potential use of extensible markup language for radiology reporting: a tutorial.
AB - One of the main goals of radiology is to communicate imaging information to aid
in patient management. Information standards can facilitate communication and
help realize this goal. Extensible Markup Language (XML) is a new information
transmission standard that was developed to meet the growing need for robust,
large-scale World Wide Web applications. XML notation provides a compact document
representation scheme that allows radiology reports to be transmitted over the
Web as universally understandable, self-defining documents. XML documents can
include a report-specific document type definition (DTD) that defines the
allowable data fields and values. XML may also be used to generate data entry
forms for radiology reporting and help physicians improve the efficiency of the
reporting process. XML documents can be used to store reporting results directly,
thus allowing pertinent data to be shared on the Web. An XML-based approach can
allow users to link information to entities outside the information systems of a
given institution. XML-based methods and applications have the potential to
promote development of robust radiology reporting systems and integration with
broader, enterprise-wide information systems.
PMID- 10682795
TI - The effects of corn milling coproducts on growth performance and diet
digestibility by beef cattle.
AB - Simmental x Angus weanling heifers (n = 96; 239 +/- 2.3 kg) were used in four
replications to evaluate three dietary treatments in Trial 1. Treatments were
cracked corn-hay diets supplemented with one of three corn milling industry
coproducts: dry corn gluten feed (DCGF), dried distillers grains (DDG), and a new
modified corn fiber (MCF). In Trial 2, ruminally cannulated mature crossbred beef
steers (n = 4; 606 +/-60 kg) were used in a 4 x 4 Latin square with 11-d periods
to determine digestibility and ruminal metabolism of limit-fed cracked corn
alfalfa haylage diets supplemented with cornstarch (CON), DCGF, DDG, or MCF.
During Periods 3 and 4, an in situ study was conducted to compare the rate and
extent of CP degradation of DCGF, DDG, and MCF. In Trial 1, there were no
differences (P > .10) in initial weights or DM intake. Average daily gain and
feed efficiency (G/F) were improved (P < .01) for heifers fed DCGF or DDG vs
heifers fed MCF. In Trial 2, no differences (P > . 10) in digestibilities of any
nutrients or in ruminal VFA concentrations were observed for steers fed
coproducts. The CON supplementation decreased (P < .05) total dietary fiber (TDF)
digestibility, improved (P < .10) digestibilities of DM and OM, increased (P <
.05) total VFA concentrations and concentrations of propionate and valerate, and
decreased (P < .05) concentrations of butyrate, isobutyrate, and isovalerate when
compared with the coproducts. Dry corn gluten feed increased (P < .05) and DDG
tended (P < .10) to increase percentages of the immediately soluble fraction of
CP, and both had increased (P < .05) rates (Kd) and greater (P < .05) extent of
ruminal CP degradation than MCF. These data suggest that DCGF and DDG may be
utilized in limit-fed high-energy diets without sacrificing performance. Feeding
of MCF resulted in poorer performance of heifers, suggesting a limited feeding
value that results from high ADIN content and slow in situ protein digestion.
PMID- 10682796
TI - Lactation and calf weight traits of mature crossbred cows fed varying daily
levels of metabolizable energy.
AB - Our objective was to evaluate differences in lactation traits and calf weights
produced by F1 cows under varying daily metabolizable energy availability.
Measures of milk yields and calf weight traits were recorded on mature F1 cows.
The cows were produced from matings of Angus or Hereford dams with sires
representing Angus/Hereford, Shorthorn, Galloway, Longhorn, Nellore, and Salers
breeds. The cows' daily DM intakes of a diet composed of a corn silage or alfalfa
silage plus corn silage were recorded from approximately 2 wk postpartum until
the calves were weaned at an average age of 170 d. Milk yield measurements were
recorded when the calves were approximately 14, 28, 56, 84, 112, 140, and 168 d
of age. Sources of variation considered for the traits of interest included sire
breed of the cow (SBC) and the covariates weaning age of the calf and daily
metabolizable energy intake (DMEI) of the cow for lactation and calf weights. The
linear and quadratic effects were evaluated for DMEI. The SBC x DMEI (linear)
interaction was significant for total milk yield. Sire breed of cow differences
(P < .05) were observed for milk yield at time of peak yield, persistency,
preweaning ADG, and weaning weight. Salers- and Shorthorn-sired cows had greater
(P < .05) peak yield than Galloway, Longhorn, or Nellore cross-bred cows but were
not significantly different from the Hereford/Angus. Increasing DMEI linearly
increased peak yield and total yield (P < .05). Preweaning ADG of calves from
Nellore-sired cows was greater (P < .05) than all SBC. Preweaning ADG of calves
from Galloway-sired cows was less than all SBC (P < .05). The linear effect of
DMEI was heterogeneous across SBC for total yield. The pooled quadratic effect of
DMEI was significant for all traits except birth weight. The DMEI for expression
of maximum weaning weight was estimated to be 29 Mcal. Feed efficiency ratios for
the test period were 28, 27, 30, 25, 28, 32, and 30 g calf weight:Mcal DMEI for
reference and 1980s Angus/Hereford-, Shorthorn-, Galloway-, Longhorn-, Nellore-,
and Salers-sired cows, respectively, at the DMEI level of 29 Mcal.
PMID- 10682797
TI - Twinning rate in Norwegian cattle: frequency, (co)variance components, and
genetic trends.
AB - The overall twinning rate was shown to increase from .6% in the first parity to
4.0% in the sixth parity, and a positive phenotypic trend for twinning rate was
observed during the time period considered (1978 to 1995). The distribution of
bulls according to the average percentage of multiple births of daughters in
first and second parity showed that some bulls had an extremely low twinning
frequency and others exceeded the population mean by approximately six times.
(Co)variance components were estimated for twinning in first and second parities
using a linear sire model. The analysis included either first- and second-crop
daughters (1.4 and .9 million records for first- and second-parity cows,
respectively) or first-crop daughters only (.6 and .4 million records for first-
and second-parity cows, respectively) from 2,043 sires. Heritability estimates
were .7 to .8% in the first parity and 2.8% in the second parity. The genetic
correlation between twinning in the first and second parities was approximately
1. Part of the phenotypic trend observed can be explained by a genetic trend for
twinning rate.
PMID- 10682798
TI - Maternal birth weight breeding value as an additional factor to predict calf
birth weight in beef cattle.
AB - A total of 1,028 birth weight (BWT) and gestation length (GL) records were
collected for calves from 1994 to 1997 in five U.S. Angus herds. Parental BWT EPD
and dam BWT maternal breeding values (MBV) computed from the entire U.S. Angus
data base after each breeding season were also available. A full model was fit to
BWT that contained contemporary group (CG), sire BWT EPD, dam BWT EPD, and dam
BWT MBV. A reduced model that dropped dam BWT MBV was also fit. The full model
had smaller (P < .01) sum of squares for error than the reduced model. Calf BWT
records were then adjusted for CG. Two data sets were formed to include adjusted
BWT progeny records from sires with BWT EPD > or = .75 or > or = 1.0 SD above the
mean of sires in the data set. Adjusted birth weights were assigned to either >
or = .75 or other < .75 SD and > or = 1.0 or < 1.0 SD categories based on the
mean BWT of calves in the entire data set. Dams were assigned to either > or =2
.75 or < .75 SD and > or = 1.0 or < 1.0 SD categories based on dam BWT EPD, MBV,
or total maternal genetic contribution (TMGC = EPD + MBV). Chi-square analyses
showed that dam BWT EPD, MBV, or TMGC categories were not independent (P < .10)
of BWT SD categories, indicating that both dam BWT EPD and BWT MBV provide useful
information to attenuate calf BWT. Calf BWT records were then adjusted for the
overall mean, CG, sire and dam BWT EPD, and dam BWT MBV. Dams were then assigned
to five categories: high dam EPD and MBV (HH), high dam EPD and low MBV (HL), low
dam EPD and high MBV (LH), low dam EPD and MBV (LL), and other (OTH). High was >
or = .75 or > or = 1.0 SD and low was < .75 or < 1.0 SD based on the mean BWT EPD
or MBV of dams in the data set. In all adjusted BWT analyses, HH, HL, and LH
categories did not differ (P > .05) from each other; however, the LL category was
less (P < .05) than all other categories, indicating that calves from LL dams
were lighter at birth than expected. For GL, LL was significantly different (P <
.05) from only HH. The large differences in birth weight for the LL dams compared
to other groups did not seem to be primarily due to shorter GL. Results showed
that MBV provided additional information to control BWT; however, when both dam
MBV and EPD were low, birth weight of calves was less than expected. Future
research should focus on explanations for this interaction.
PMID- 10682799
TI - Breed and sex differences in growth curves for two breeds of dog guides.
AB - A desirable dog guide weighs 18 to 32 kg as an adult. Male and female German
shepherd dogs and male and female Labrador retrievers were weighed between birth
and 18 mo of age, with at least one weight recorded after 290 d of age. Growth
curves were constructed from 10,484 observations on 880 dogs using the Gompertz
function in the form Wt = W(max)exp(-e[-(t-c)/b]), where Wt is weight at time t,
Wmax is mature body weight, b is proportional to duration of growth, c is age at
point of inflection, and t is age in days. Estimates for mature body weight were
2.4 +/- .3 kg higher for Labrador retrievers than for German shepherd dogs and
4.7 +/- .2 kg higher for males than for females. Male Labrador retrievers were
closest to the upper limit for desirable weight, with an average estimated mature
weight of 31.4 +/- .3 kg. Duration of growth, 4b + c, was not different between
the breeds; however, the estimate for males was 8 +/- 5d longer than for females.
Female Labrador retrievers had the shortest estimate for growth of 319 +/- 6 d.
The estimate for age at the point of inflection was 3.6 +/- 1.2 d greater for
males than for females, but not different between breeds. A better understanding
of growth curves for dog guides may aid in estimating mature weight at a young
age, thus allowing earlier breeding and training decisions to be made and
increasing genetic change per year.
PMID- 10682800
TI - Variance and covariance components for weaning weight for Herefords in three
countries.
AB - Records from the Hereford Associations of the United States (USA), Canada, and
Uruguay were used to estimate genetic and phenotypic variances and covariances
for weaning weight. Estimation was done using a complete animal model, relatively
large data sets, and the same methodology for the three countries in order to
determine whether genetic parameters for weaning weight were homogeneous across
environments. Data were composed of 2,322,722, 487,661, and 102,986 edited
weaning weight records for USA, Canada, and Uruguay, respectively. Ten samples
were obtained from each country by eliminating data from small herds with fewer
than 500 records, selecting herds at random from the entire data set after
removing the small herds, and then retaining the direct-sire-connected
contemporary groups within each sample. The final sample sizes ranged from 9,832
to 46,377 records. An accelerated EM-REML algorithm was used in estimating the
(co)variance components in each sample. The estimates were pooled by calculating
the arithmetic mean of the 10 samples from within each country. Direct and
maternal (in parentheses) heritability estimates were .24 (.16), .20 (.16), and
.23 (.18) for USA, Canada, and Uruguay, respectively. Maternal heritabilities
reported here are nearly 50% smaller than the values currently used in national
genetic evaluation for the breed, which were estimated using sire-maternal
grandsire models. Covariance between direct and maternal was negative in all
countries, accounting for 6, 8, and 10% of the total phenotypic variation, and
the total dam effect was 32.5, 37.0, and 34.0% in USA, Canada, and Uruguay,
respectively. Total heritabilities were similar among the countries, with values
of .19, .19, and .17 for the three respective countries. The similarity of
genetic and environmental parameters across the three countries suggests that
joint genetic evaluation is feasible across environments provided that the
genotype x environment interaction is negligible and can be ignored.
PMID- 10682801
TI - Few differences found between early- and late-weaned pigs raised in the same
environment.
AB - Segregation and medicated early weaning are technologies used to optimize the
productivity and health of pigs, but these practices may also cause aberrant
behaviors indicative of stress. Thus, differences in early- (=10 d of age) and
late- (=30 d of age) weaned pigs were investigated. At weaning, pigs were housed
in groups of four in 16 pens (eight pens per treatment) in the same facility,
and, thus, they were not segregated. Body weights were recorded at birth,
weaning, and at approximately 42, 65, 102, 137, and 165 d of age (at slaughter).
One-minute, instantaneous scan samples during a 10-min period (at 0600, 1000,
1400, and 1800) were used to record the frequency of lying, standing, and
sitting, total number of drinks, feeder investigations, and time spent
playing/fighting on 2, 3, and 4 d after weaning. Five-minute, direct observations
of each pig were conducted at approximately 40, 60, 80, and 150 d of age. Direct
observations were also made of the entire pen for 10 min at approximately 50, 95,
123, and 160 d of age to record aberrant behaviors. At 62 d of age, a handling
and blood collection stress was imposed. At 165 d of age, a second stress test
was conducted in response to rough handling and transport. Early-weaned pigs
spent more time playing/ fighting (P < .006) than late-weaned pigs during the 4 d
after weaning, manipulated conspecifics more often at 40 d of age (P < .002), had
greater percentage of hemoglobin (P < .03) during Stress Test 1, had greater ADG
at 42 d of age (P < .03), and had greater hypothalamic growth hormone-releasing
hormone receptor mRNA at slaughter (P < .06). Late-weaned pigs had greater ADG
between 137 and 165 d of age (P < .03) and greater pro-opiomelanocortin at
slaughter (P < .04). Overall, most differences found between early-weaned and
late-weaned pigs were evident soon after weaning, but they disappeared before
slaughter.
PMID- 10682802
TI - Effects of birth weight and postnatal nutrition on neonatal sheep: II. Skeletal
muscle growth and development.
AB - This study investigated effects of birth weight and postnatal nutrition on growth
and development of skeletal muscles in neonatal lambs. Low (L; mean +/- SD 2.289
+/- .341 kg, n = 28) and high (H; 4.840 +/- .446 kg, n = 20) birth weight male
Suffolk x (Finnsheep x Dorset) lambs were individually reared on a liquid diet to
grow rapidly (ad libitum fed, ADG 337 g, n = 20) or slowly (ADG 150 g, n = 20)
from birth to live weights (LW) up to approximately 20 kg. At birth, weight of
semitendinosus (ST) muscle in L lambs was 43% that in H lambs; aggregate weights
of ST and seven other dissected muscles were similarly reduced. In ST muscle of L
lambs, mass of DNA, RNA, and protein were also significantly reduced to levels
67, 60, and 34%, respectively, of those in H lambs. However, myofiber numbers of
ST, tibialis caudalis, or soleus muscles did not differ between the L and H birth
weight lambs and did not change during postnatal growth. During postnatal
rearing, daily accretion rate of dissected muscle was lower in L than in H lambs.
Accretion of muscle per kilogram of gain in empty body weight (EBW) was reduced
in the slowly grown L lambs compared with their H counterparts, although the
difference was less pronounced between the rapidly grown L and H lambs.
Throughout the postnatal growth period, ST muscle of L lambs contained less DNA
with a higher protein:DNA ratio at any given muscle weight than that of H lambs.
Slowly grown lambs had heavier muscles at any given EBW than rapidly grown lambs.
Content of DNA and protein:DNA ratio in ST muscle were unaffected by postnatal
nutrition, but RNA content and RNA:DNA were greater and protein:RNA was lower at
any given muscle weight in rapidly grown lambs. Results suggest that myofiber
number in fetal sheep muscles is established before the presumed, negative
effects of inadequate fetal nutrient supply on skeletal muscle growth and
development become apparent. However, proliferation of myonuclei may be
influenced by fetal nutrition in late pregnancy. Reduced myonuclei number in
severely growth-retarded newborn lambs may limit the capacity for postnatal
growth of skeletal muscles.
PMID- 10682803
TI - Ovine adipose tissue monounsaturated fat content is correlated to depot-specific
expression of the stearoyl-CoA desaturase gene.
AB - The basis for the variation in fatty acid composition in different ovine adipose
tissue depots was investigated. The proportion of stearic (C18:0) and oleic
(C18:1) acids vary in a site-specific fashion; abdominal depots (omental and
perirenal) contain relatively more C18:0 than C18:1, and carcass depots,
especially sternum, have a markedly higher proportion of C18:1. Additionally,
expression of a number of lipogenic enzyme genes (stearoyl-CoA desaturase [SCD],
acetyl-CoA carboxylase-alpha [ACC-alpha], lipoprotein lipase [LPL]) and the
cytoskeletal protein gene alpha-tubulin vary among depots, although the pattern
of variation differs for each mRNA. When these expression data were related to
the mean cell volume of adipocytes pooled from all depots, a significant pattern
emerged: expression of the ACC-alpha, LPL, and alpha-tubulin genes was highly
correlated with the size of adipocytes. In contrast, when the expression of SCD
mRNA was assessed as a function of mean cell volume, two populations of
adipocytes emerged: no significant correlation was found between the expression
of SCD mRNA per adipocyte and mean cell volume for the abdominal depots, although
a highly significant correlation was observed between SCD gene expression and
mean cell volume for the carcass and epicardial depots. Similarly, a highly
significant correlation was found for the amount of C18:1 per adipocyte and the
abundance of SCD mRNA per adipocyte for the carcass and epicardial depots,
whereas no significant correlation was observed for these traits for the omental
and perirenal depots. Thus, the SCD gene seems to be regulated in a depot
specific fashion and in a manner distinct from that of the ACC and LPL genes.
PMID- 10682804
TI - Messenger ribonucleic acid expression of the MyoD gene family in muscle tissue at
slaughter in relation to selection for porcine growth rate.
AB - Livestock meat production capacity is related to muscle fiber numbers and growth.
Muscle fibers develop during early embryonic development from proliferating and
differentiating myoblasts. Post-natal muscle growth requires satellite cell
proliferation and differentiation. Myoblast and satellite cell proliferation and
differentiation is regulated by the genes of the MyoD gene family (myogenin, myf
5, myf-6, and MyoD1). Our aim was to study the mRNA expression of these genes in
postnatal muscle tissue in relation to porcine selection for growth rate or
leanness. Five boars from a line selected for fast growth (F-line) and five boars
from a line selected against backfat thickness (L-line) were slaughtered, and
biopsies were taken from 12 muscles. Between-line effects, within-line effects in
relation to the performance of the pigs, and muscle-specific effects were
studied. Comparing the F-line with the L-line revealed significantly greater
myogenin, myf-5, and MyoD1 mRNA expression in some muscles of the F-line. The
expression of myf-6 showed a tendency for the opposite effect in some muscles.
Muscles were ordered by their muscle-specific growth rate (b-value). Within-line
evaluation of the data revealed a systematic muscle effect for the myf-6
expression level in the F-line because higher b-values correlated with increased
myf-6 expression level. Backfat thickness was negatively related to myogenin
expression in the F-line. A relationship was found between myogenin:MyoD1 mRNA
expression ratio and meat color/muscle fiber type composition in the L-line.
Furthermore, the myogenin:MyoD1 ratio was greater in muscles from F-line boars
than in muscles from L-line boars, which relates to the difference between the
lines in muscle fiber type. We conclude that the mRNA levels of the MyoD genes in
porcine muscle tissue at slaughter showed different relationships to selection
for growth rate when evaluated between selection lines and within selection
lines.
PMID- 10682805
TI - Protein kinetics in callipyge lambs.
AB - The objectives for this experiment were to determine the effect of the callipyge
phenotype on protein kinetics. We studied callipyge and normal lambs (n = 37) at
5, 8, and 11 wk of age (n = 4 to 7/ group) to determine how protein kinetics are
altered by this trait. Total protein, DNA, and RNA and calpastatin activity were
measured in five skeletal muscles and in the heart, kidneys, and liver, and
protein accretion rates were calculated. At 8 wk, the fractional synthesis rates
of proteins in these tissues were measured in vivo using a primed, continuous 8-h
infusion of [2H5]phenylalanine. Fractional rates of protein degradation were
estimated by differences. At 5 wk of age, muscle weights, protein mass,
protein:DNA, RNA:DNA, and calpastatin activity were higher (P < .05) for
callipyge, and protein mass differences continued to increase through 11 wk. At 8
wk, fractional rates of protein synthesis and degradation were lower (P < .05) in
callipyge than in normal lambs. The organs of callipyge lambs exhibited reduced
growth at 11 wk. Thus, enhanced muscle growth seems to be maintained in callipyge
lambs by reduced protein degradation rather than increased protein synthesis.
However, we cannot exclude the possibility that the initial onset of the
callipyge condition may be caused by an increase in the fractional rate of
protein synthesis.
PMID- 10682806
TI - Added dietary pyridoxine, but not thiamin, improves weanling pig growth
performance.
AB - We conducted two trials to determine the effects of added dietary pyridoxine
(vitamin B6) or thiamin (vitamin B1) on growth performance of weanling pigs. In
Exp. 1, weanling pigs (n = 180, initially 5.55 +/- .84 kg, and 21 +/- 2 d of age)
were fed either a control diet (no added pyridoxine or thiamin) or the control
diet with added thiamin (2.8 or 5.5 mg/kg) from thiamin mononitrate or pyridoxine
(3.9 or 7.7 mg/kg) from pyridoxine HC1. These five diets were fed in meal form in
two phases (d0 to 14 and 14 to 35 after weaning), with identical vitamin
concentrations in both phases. From d 0 to 14 after weaning, pigs fed added
pyridoxine had increased (quadratic, P < .05) ADG and ADFI; pigs fed 3.9 mg/kg of
added pyridoxine had the greatest improvement. From d 14 to 35 and 0 to 35, ADG
and ADFI increased (linear P = .06) for pigs fed increasing pyridoxine. Growth
performance was not improved by added thiamin. In Exp. 2, weanling pigs (n = 216,
initially 6.08 +/- 1.13 kg, and 21 +/- 2 d of age) were fed a control diet or the
control diet with 1.1, 2.2, 3.3, 4.4, or 5.5 mg/kg of added pyridoxine from
pyridoxine HCl. From d 0 to 14 after weaning, increasing pyridoxine increased
(quadratic, P < .05) ADG and ADFI; pigs fed 3.3 mg/kg of added pyridoxine had the
greatest ADG and ADFI. Break-point analysis suggested a requirement estimate of
3.3 and 3.0 mg/kg of added pyridoxine to maximize ADG and ADFI, respectively.
From d 14 to 35 or 0 to 35, increasing pyridoxine had no effect (P > .10) on pig
growth performance. These results suggest that adding 3.3 mg/kg of pyridoxine
(7.1 to 7.9 mg/kg of total pyridoxine) to diets fed from d 0 to 14 after weaning
can improve pig growth performance.
PMID- 10682807
TI - Efficacy of yeast phytase in improving phosphorus bioavailability in a corn
soybean meal-based diet for growing pigs.
AB - Crossbred barrows (n = 66; 6 wk old) were used in a 6-wk experiment to evaluate
the efficacy of phytase from yeast or Aspergillus niger on performance, tibial
characteristics, and serum inorganic P concentration. We also investigated the
stability of these phytases in acidic solutions with pepsin, which simulated
gastric conditions. Pigs were fed a P-adequate diet containing .34% nonphytate-P
or a low-P diet containing .20% nonphytate-P. The low-P diet was supplemented
with 0, 1,000, 2,000, or 4,000 phytase units (PU; the activity at optimal pH,
i.e., pH 4.2 for yeast phytase and pH 5.5 for phytase from Aspergillus niger)/kg
of yeast phytase, or 1,000 PU/kg phytase from Aspergillus niger. The graded level
of yeast phytase linearly increased ADG (P = .047), tibial weight (P = .091),
tibial density (P < .001), and P concentration in tibial cortex (P = .018).
Aspergillus niger phytase also increased ADG (P = .022), serum inorganic P
concentration (P < .001), tibial density (P = .007), and tibial P concentration
(P = .025). The pigs given 1,000 PU/kg Aspergillus niger phytase showed greater
ADG (P = .091), tibial density (P= .001), and tibial P concentration (P = .062)
than those given 1,000 PU/kg yeast phytase. No measurements differed (P > .31)
between the pigs given 1,000 PU/kg Aspergillus niger phytase and those given
4,000 PU/kg yeast phytase. These results suggested that yeast phytase improves
bioavailability of P in the diet for growing pigs but the efficacy of yeast
phytase is less than that of Aspergillus niger phytase. During incubation in
acidic solutions with pepsin, yeast phytase (P < .001) lost more of its activity
than Aspergillus niger phytase. This lesser stability of yeast phytase may be
responsible for the poorer efficacy of yeast phytase than that of Aspergillus
niger. In summary, supplementation of swine diets with yeast phytase is
beneficial, but its efficacy is less than that of Aspergillus niger phytase.
PMID- 10682808
TI - Effect of organic and inorganic selenium sources and levels on sow colostrum and
milk selenium content.
AB - A study was conducted to evaluate the short-term effects of feeding two dietary
Se sources at various Se levels on the transfer of Se to the dam's milk and
nursing pig. Six dietary treatments were arranged in a 2 x 2 factorial
arrangement with two additional treatments in a randomized complete block
designed experiment. Inorganic (sodium selenite) or organic (Se-enriched yeast)
Se sources were added to the diet at .15 or .30 ppm Se. A non-Se-fortified corn
soybean meal basal diet served as a negative control, and a sixth group was fed
.15 ppm Se from both inorganic and organic Se sources. A total of 43 sows were
fed their treatment diets at 2.2 kg/d from 6 d prepartum to parturition and at
full feed through a 14-d lactation period. Ten sows were initially bled at 6 d
prepartum, and three sows and three pigs from their litters were bled at 7 and 14
d postpartum. Serum was analyzed for its Se concentration and glutathione
peroxidase (GSH-Px) activity. Colostrum was collected within 12 h postpartum and
milk at 7 and 14 d of lactation. When the basal diet was fed, sow serum GSH-Px
activity declined from 6 d prepartum and remained low throughout lactation. When
dietary Se levels increased, sow serum Se concentration and serum GSH-Px activity
increased (P < .05) at both 7 and 14 d postpartum. The short-term feeding of
either Se source at .15 or .30 ppm Se did not affect colostrum Se content when
inorganic Se was fed, but it was increased when organic Se was provided. This
resulted in a significant Se source x Se level interaction (P < .01). Milk Se at
7 and 14 d postpartum was 2.5 to 3 times higher when the organic Se source was
provided and resulted in a significant Se source x Se level interaction (P <
.05). When the combination of inorganic and organic Se was fed at .15 ppm Se,
colostrum and milk Se contents were similar to those of sows fed .15 ppm Se from
the organic Se source. Pig serum GSH-Px activity was not affected at 7 and 14 d
of age by dietary Se level or Se source fed to the sow, but serum Se increased (P
< .05) as dietary Se level increased, particularly when sows had been fed organic
Se. The results demonstrated that organic Se increased milk Se content more than
did inorganic Se and increased the nursing pig's serum Se. These results indicate
that inorganic Se was more biologically available for sow serum GSH-Px activity,
but organic Se was more effectively incorporated into milk.
PMID- 10682809
TI - Effects of dietary calcium:phosphorus ratios on apparent absorption of calcium
and phosphorus in the small intestine, cecum, and colon of pigs.
AB - Thirty-two crossbred barrows were used to investigate the effects of dietary
Ca:total P (tP) ratios in phytase-supplemented diets on the apparent absorption
of P and Ca in the small intestine, cecum, and colon. Three Ca:tP ratio
treatments (1.5:1, 1.3:1, or 1.0:1) were created by adjusting the amount of
ground limestone added to the basal low-P grower (.39% tP including .07% added
inorganic P) and finisher (.32% tP without added inorganic P) diets. All low-P
ratio diets were supplemented with Natuphos phytase at 500 units/kg. A positive
control diet without phytase supplementation contained adequate P and Ca to meet
dietary requirements. At 123 kg, the pigs were slaughtered and the contents of
ileum, cecum, and colon were collected. Lowering the dietary Ca:tP ratio in the
diets containing phytase linearly increased (P < .01) the apparent absorption (%
and g/d) of P in the small intestine, but Ca absorption was not affected. Pigs
fed the low-P diet with a Ca:tP ratio of 1.0:1 had an apparent absorption (g/d)
of P or Ca similar to that of pigs fed the control diet, which was adequate in Ca
and P. Averaged across all diets, the apparent absorption of P was highest when
measured at the cecum, and the apparent absorption of Ca was highest when
measured at the colon. In conclusion, lowering the dietary Ca:tP ratio to 1.0:1
in a low-P diet containing phytase increased the apparent absorption of P in the
small intestine. Furthermore, a significant amount of P was absorbed in the
cecum.
PMID- 10682810
TI - Effect of vitamin E sources (RRR- or all-rac-alpha-tocopheryl acetate) and levels
on sow reproductive performance, serum, tissue, and milk alpha-tocopherol
contents over a five-parity period, and the effects on the progeny.
AB - Two dietary sources of vitamin E (DL-alpha-tocopheryl acetate [DL-beta-TAc], or D
alpha-tocopheryl acetate [DL-alpha-TAc]) at two dietary supplemental levels (30
vs 60 IU/kg) were evaluated in reproducing sows over a five-parity period. The
experiment was a 2 x 2 factorial arrangement of treatments conducted as a
randomized complete block in two replicates. A total of 48 gilts were fed their
treatment diets from 40 kg BW through five parities, reflecting a total of 171
farrowings. Reproductive measurements of litter size, sow weight, and back-fat
thickness were collected. The incidence of mastitis-metritis-agalactia (MMA) and
fluid discharge from the vagina were evaluated for each sow on each of the first
3 d postpartum. Sows were bled at periodic intervals during gestation and at
weaning (21 d) and serum was frozen. After the fifth parity, two to four sows
from each treatment group were killed and tissues collected. At birth, two to
three neonatal pigs were killed from each sow treatment group within each parity
and livers were collected and frozen. In addition, three pigs from each litter
from three to four sows per treatment group within each parity were bled at
weaning and serum was saved. Six pigs from each sow group at weaning of Parity 5
were also killed and livers were collected and frozen. Sow and pig sera and
tissues were analyzed for a-tocopherol. There was no effect (P > .15) of vitamin
E source or level on the various sow reproductive measurements, litter size, or
the incidences of MMA or fluid discharges from the vagina. Feeding D-alpha-TAc
compared with DL-alpha-TAc or 60 IU compared with 30 IU vitamin E/kg diet
resulted in higher (P < .01) sow serum, colostrum, and milk alpha-tocopherol
contents at each measurement period. Sow liver, adipose, lung, and heart alpha
tocopherol contents were also higher (P < .01) when the 60 IU vitamin E level had
been fed. Both serum and liver a-tocopherol contents in 21-d-old nursing pigs
were higher (P < .01) when the sow had been fed D-alpha-TAc compared with the DL
alpha-TAc source or when the 60 IU level had been fed. There were no vitamin E
source x vitamin E level interactions (P > .15) for the various alpha-tocopherol
measurements. Although the supplemental vitamin E sources were provided on an
equivalent IU basis, these results suggest that D-alpha-TAc has a higher
equivalency than DL-alpha-TAc on an IU basis, but higher dietary levels also
resulted in higher sow and pig alpha-tocopherol contents.
PMID- 10682811
TI - Effect of feather meal as a source of valine for lactating sows.
AB - An experiment was conducted to evaluate feather meal as a source of Val in
lactating sow diets. Sows (five farrowing groups; mean parity = 2.34) were
allotted to one of two dietary treatments on the basis of ancestry, parity, and
weight and date of d 110 of gestation. The treatment diets included 1) corn
soybean meal lactation diet (n = 40) or 2) corn-soybean meal lactation diet with
2.5% feather meal (n = 39). The diets were formulated on an equal Lys basis. All
litters were adjusted to 10 pigs within 24 h after farrowing, and all sows weaned
at least nine pigs. Sows were bled at 110 d of gestation and at weaning, and
serum urea N was determined. Backfat thickness was determined ultrasonically at
110 d of gestation and at weaning. Serum urea N and backfat thickness at d 110 of
gestation were used as covariates for serum urea N and backfat thickness at
weaning, respectively. The litter response criteria (weaning weight, litter
weight gain, and percentage survival) were not affected (P > .10) by feather
meal. The sow response criteria (weaning weight, weight loss per day, weaning
backfat thickness, change in backfat thickness, ADFI, and days to estrus) were
not affected (P > .10) by feather meal. Sows fed feather meal had increased (P <
.01) serum urea N and tended (P = .15) to have decreased sow weaning weight.
Following the initial analysis of the data, the data set was split into two
groups: 1) sows with litters gaining less than 2.17 kg/d (n = 19 and 20 for
control and feather meal diets, respectively) and 2) sows with litters gaining
more than 2.17 kg/d (n = 21 and 19 for control and feather meal diets,
respectively). These two groups were analyzed separately. In sows with litters
gaining less than 2.17 kg/d, the litter and sow criteria were not affected (P >
.10) by treatment. In sows with litters gaining more than 2.17 kg/d, sow weaning
weight was decreased (P < .04) and sow weight loss (P < .02) and serum urea N (P
< .01) were increased in sows fed feather meal. Feather meal (as a source of Val)
did not improve litter weight gain, but it increased serum urea N.
PMID- 10682812
TI - Physiological responses of Brahman and Hereford steers to an acute ergotamine
challenge.
AB - Research was conducted to evaluate the sensitivity of Bos indicus and Bos taurus
cattle to a tall fescue ergopeptine alkaloid by assessing vital sign responses.
Eight Polled Hereford and seven Red Brahman steers received bolus i.v. injections
of ergotamine tartrate and saline vehicle in a simple cross-over design.
Physiological traits measured 30 min and immediately before and 30, 60, and 90
min after treatment were respiration rate, rectal temperature, skin temperature
at the tailhead and tail tip, systolic and diastolic blood pressure, and heart
rate. Blood samples were collected immediately before and 105 min after
treatments to determine plasma prolactin and cortisol concentrations. Steers were
fed a fescue-free diet in drylot. Ambient temperature and relative humidity
averaged 31 degrees C and 55%, respectively, during data collection. No breed x
treatment x time interactions were apparent for vital signs. The treatment x time
interaction was significant (P < .05) for blood pressure and skin temperature.
Ergotamine increased (P < .01) blood pressure and decreased (P < .01) skin
temperature. The breed x treatment x time interactions were significant for
prolactin (P < .1) and cortisol (P < .01). Ergotamine decreased plasma (P < .01)
prolactin and increased (P < .01) cortisol concentrations in both breeds, despite
some breed variation. Across all traits, Brahman and Hereford steers responded
similarly to acute ergotamine exposure, indicating that the breeds are alike in
acute sensitivity to a systemically administered ergopeptine alkaloid associated
with fescue toxicosis.
PMID- 10682813
TI - Morphology of luminal and glandular epithelial cells from pig endometrium grown
on plastic or extracellular matrices.
AB - Luminal (LE) and glandular epithelial (GE) cells from d-13 pregnant pigs were
cultured on plastic, matrix secreted from endometrial stroma, and EHS matrix
(Matrigel) in culture medium (RPMI-1640) supplemented with 20 and 10% fetal
bovine serum, respectively. After culture for 7 and 14 d, GE and LE cells were
prepared for transmission and GE cells for scanning electron microscopy. The two
types of endometrial epithelial cells displayed different morphological
characteristics when grown on different culture substrates. On plastic, the GE
and LE cells formed flattened monolayers. However, stroma-secreted matrix
directed the polarization of endometrial epithelia. The GE and LE cells reacted
differently to thick Matrigel coatings; LE cells formed a colony after 7 d of
culture and then proliferated further to form a colony with a cavity, but GE
cells organized to form a colony with a shallow depression in the center at 7 d
and developed duct-like structures after 14 d in vitro. Luminal epithelial cells
grown on either diluted or thin-coated Matrigel and grown on stroma-secreted
matrix formed a monolayer but no three-dimensional structures.
PMID- 10682814
TI - Plasma fatty acids, prostaglandin F2alpha metabolite, and reproductive response
in postpartum heifers fed rumen bypass fat.
AB - An experiment was conducted to determine whether feeding rumen-protected fatty
acids (FA) to postpartum heifers would increase plasma concentrations of linoleic
acid and PGF2, metabolite (PGFM), shorten the interval from calving to first
increase in plasma concentrations of progesterone (P4), and increase pregnancy
rate relative to controls. Hereford x Angus heifers (346 kg) were assigned
randomly to treatments containing either lipid or barley supplemented diets for
the first 30 d postpartum. Lipid was .23 kg.heifer(-1).d(-1) of calcium salts of
FA (CSFA; n = 20), and an isocaloric amount of barley served as the control (n =
19). Supplements, with .23 kg of barley as a vehicle, and a basal diet of meadow
and alfalfa hays were pen fed to heifers (5/pen). Heifers were bled on alternate
days (d1 to 30) and twice weekly (d 30 to 2 wk after first estrus) for RIA of
plasma PGFM and P4, respectively. Weight percentage of major FA in plasma on d1
and 7 was determined with gas chromatography. First behavioral estrus was
detected by use of intact bulls and confirmed by an increase in plasma P4. On d
7, but not d 1, plasma from heifers fed CSFA had altered proportions of major FA
(P < .01), including an increase in linoleic acid compared with those of controls
(29.1 vs 25.6% of total FA; SE = .75; P < .01). Analysis of variance of contrast
variables revealed an effect of treatment on direction of change in PGFM from d 3
to 5 (P < .01). By d 7 and on d 9, plasma concentrations of PGFM were greater in
heifers fed CSFA than in controls (P = .02 and P = .06, respectively). There was
no difference in plasma concentration of PGFM between treatments on d 1, 3, 5,
11, 13, and 15 postpartum (P = .80, .17, .52, .82, .46, and .77, respectively).
Days to first estrus with ovulation, pregnancy rate, and calving interval were
not affected by treatments (P = .58, .52, and .24, respectively). Although
supplemental lipid fed to primiparous beef heifers increased plasma levels of
linoleic acid and production of PGFM in the early postpartum period, it did not
improve the fertility of these heifers in the subsequent breeding season.
PMID- 10682815
TI - Use of a small dose of estradiol benzoate during diestrus to synchronize
development of the ovulatory follicle in cattle.
AB - We tested the hypothesis that a small dose of estradiol benzoate (EB) at the
midstage of the estrous cycle in cattle would synchronize the subsequent pattern
of ovarian follicular development, estrus, and ovulation. Nonlactating Friesian
cows received either 1 mg of EB i.m. on d 13 of the estrous cycle (T; n = 12;
estrus = d0) or served as untreated controls (C; n = 12). Their ovaries were
examined daily with transrectal ultrasonography from d 7, and blood samples were
collected 0, 2, 4, 8, 24, and 48 h after treatment on d 13. Plasma concentrations
of estradiol-17beta were elevated to 12 pg/mL during the initial 24 h following
treatment, compared with a baseline of 1 pg/mL in untreated controls (P < .001).
Progesterone concentrations in cows of the T group declined between 24 and 48 h
after treatment (-3.2 +/- .5 ng/mL) compared with little change in concentrations
of progesterone in cows of the C group at this time (P < .01). This difference
was coincident with an earlier time to regression of the corpus luteum in cows of
the T group. Disregarding treatment groups, the second dominant follicle of the
estrous cycle (DF2) emerged on d 10.6 +/- .3 and was 9.4 +/- .4 mm in diameter on
d 13. Further growth of the DF2 was halted by EB treatment on d 13. Cessation of
growth occurred irrespective of whether the DF2 was in the early or late growth
phase, and a new follicular wave emerged 4.5 +/- .2 d later. The dominant
follicle from this wave (DF3) ovulated 5 d after emergence in most cases. During
the estrous cycle of every cow in the T group, there were three waves of
follicular development (3-wave), whereas the ratio of 2:3 waves of follicular
development in cows of the C group was 1:3. Consequently, the interval from
emergence to ovulation of the ovulatory dominant follicle in cows of the C group
ranged from 3 to 11 d. The dynamics of ovarian follicular wave development during
the estrous cycle can be strategically manipulated by treating with a small dose
of EB to synchronize proestrous development of the ovulatory follicle.
PMID- 10682816
TI - Reduced oxygen tension and EDTA improve bovine zygote development in a chemically
defined medium.
AB - Bovine zygotes produced by in vitro oocyte maturation and fertilization were
cultured for 7.5 d in a chemically defined medium without serum or proteins,
except .12 IU/mL of insulin. In Exp. 1, embryos were cultured in approximately
20% oxygen (i.e., 5% CO2 in air) or 5% CO2; 5% O2; 90% N2, with the metal
chelators EDTA or diethylenetetraaminopentaacetic acid (DTPA) at 0, 5, 25, or 125
microM. More (P < .01) embryos developed to blastocysts at 5% O2 (17%) than at
20% O2 (7%). Also, embryos grown at 5% O2 averaged more cells than embryos
cultured at -20% O2 (38 vs 29 cells for morulae and blastocysts and 15 vs 12
cells including all embryos; P < .05). There were interactions (P < .01) among
chelator, concentration of chelator, and oxygen tension. The most efficacious
treatments were 5 microM EDTA at 5 or -20% O2 (24 and 20% blastocysts), 5 microM
DTPA at 5% O2 (28% blastocysts), and 25 microM EDTA at 5% O2 (25% blastocysts).
High concentrations of either chelator were detrimental, especially at -20% O2.
In Exp. 2, a smaller range of chelator concentrations was compared (EDTA: 3, 9,
27, or 81 microM, DTPA: 3 or 15 microM) in 5% O2. More embryos developed to
blastocysts and expanded blastocysts with 3 microM EDTA than the control without
a chelator (20 and 16% vs 7 and 3%, respectively; P < .05). However, in Exp. 3,
which concerned embryo development in .33, 1, 3, or 27 microM EDTA and .33, 1, or
3 microM DTPA, no concentration of either chelator was better (P > . 1) than the
control.
PMID- 10682817
TI - Amino acid flux in ruminal and gastric veins of sheep: effects of ruminal and
omasal injections of free amino acids and carnosine.
AB - The possibility of free amino acid (FAA) and peptide absorption across the
ruminant stomach wall was studied in multicatheterized wethers fed every 12 h.
During the last third of the feeding cycle, two intraruminal or intraomasal
injections of solutions containing increasing amounts of Ser, Gly, Val, Met, Phe,
Lys, and carnosine were successively performed. Before injections, a net uptake
of each of these FAA was measured in the ruminal and the gastric veins. The
ruminal injections produced a linear increase in ruminal FAA concentration. The
highest ruminal concentrations (observed with 3 g of FAA and carnosine) ranged
between 5 and 14 mM. After ruminal injections, Ser (P < .05), Gly (P < .05), Val
(P < .05), Met (P < .10), and Lys (P < .10) uptake decreased and carnosine net
release linearly increased (P < .05), suggesting absorption across the ruminal
epithelium. Owing to the low net flux generated by high ruminal concentration,
the ruminal epithelium permeability to these molecules seemed to be low. After
omasal injections, net flux of injected FAA were not modified, suggesting a low
permeability of the gastric epithelia to FAA. Carnosine net release linearily
increased (P < .05) with increasing level of carnosine injection, indicating the
possibility of dipeptide absorption at the gastric level. This study demonstrated
in vivo that the stomach epithelia possess the capacity to absorb FAA and small
peptides; however, the permeability of these epithelia to these molecules seemed
limited.
PMID- 10682818
TI - Effects of base ingredient in cooked molasses blocks on intake and digestion of
prairie hay by beef steers.
AB - Twelve steers (332 kg) were used in three simultaneous 4 x 3 incomplete Latin
squares to evaluate effects of beet molasses (BEET), cane molasses (CANE), or
concentrated separator by-product (CSB) as base ingredients in cooked molasses
blocks on intake and digestion of prairie hay and ruminal characteristics. All
steers had ad libitum access to prairie hay (5.9% CP and 69.4% NDF; DM basis).
The four experimental treatments included a control (no supplement) and three
cooked molasses blocks, based on BEET, CANE, or CSB, fed daily at .125% of BW
(.42 kg/d as-fed, .13 kg/d CP). Forage OM, NDF, and N intakes; digestible OM,
NDF, and N intakes; and total tract OM and N digestibilities (percentage of
intake) were greater (P < .05) for steers fed cooked molasses blocks than for
control steers. Total tract OM digestibility was greater (P < or = .06) for
steers fed BEET blocks (54.0%) than for those fed CSB (52.1%) or CANE blocks
(52.2%). Digestion of NDF was greatest (P < .05) for steers fed BEET blocks
(51.9%) and tended to be greater (P < .07) for steers fed CANE (49.3%) or CSB
blocks (49.3%) than for control steers (46.9%). Ruminal ammonia concentrations
were greater (P < .05) for steers fed cooked molasses blocks (.89 mM) than for
control steers (.21 mM); this was primarily due to increases to 4.6 mM at 2 h
postfeeding for steers fed blocks. Concentrations of total VFA in ruminal fluid
were greater (P < .05) for steers fed BEET (92.7 mM) and CSB (88.1 mM) blocks
than for control steers (80.3 mM), whereas concentrations for steers fed CANE
blocks were intermediate (85.4 mM). Steers supplemented with cooked molasses
blocks had greater molar percentages of butyrate than did control steers,
particularly shortly after feeding. In summary, supplementation with cooked
molasses blocks increased forage intake and digestion. The three base ingredients
elicited similar responses, although steers fed BEET had slightly greater OM and
NDF digestibilities than those fed CANE or CSB.
PMID- 10682819
TI - Efficacy of laidlomycin propionate in low-protein diets fed to growing beef
steers: effects on steer performance and ruminal nitrogen metabolism.
AB - We conducted two experiments to evaluate the effect of the ionophore laidlomycin
propionate (LP) on steer performance and ruminal N metabolism. Experiment 1 was a
91-d growth study evaluating the growth and ruminal characteristics of steer
calves consuming supplemental LP. Steers (n = 96; 255 +/- 3 kg; four steers/pen;
six pens/treatment) were used in a randomized complete block design with a 2 x 2
factorial arrangement of treatments consisting of two levels of dietary CP
(formulated to be 10.5 and 12.5% of DM) with and without LP (11 mg/kg diet DM).
Ruminal fluid was collected via stomach tube on d 91 from one steer randomly
selected from each pen. No CP x LP interactions were observed with performance
data (P > .64). Final weight and total gain were greater (P < .07) for 12.5% CP
and LP compared with 10.5% CP and control steers, respectively. Also, DMI was
increased (P = .08) with 12.5% CP but not with LP supplementation (P = .36). In
addition, ADG and gain:feed ratio were greater (P < .03) for both 12.5% CP and
supplemental LP. Ruminal NH3 N concentration was greater (P < .09) with 12.5% CP
and LP. Total VFA concentration and molar proportion of acetate were not affected
by treatment (P > .11). However, propionate concentration was increased (P < .09)
with 12.5% CP and LP, and acetate:propionate was lower (P = .02) with LP
supplementation. In Exp. 2, six steers were used in a replicated 3 x 3 Latin
square design to compare ruminal fermentation and protein degradation in steers
without ionophore feeding or adapted to LP or monensin. In vitro deamination of
amino acids by adapted ruminal microbes was also assessed. Ionophore
supplementation decreased (P = .07) ruminal NH3 N concentration compared with
control steers, and LP increased (P = .02) ruminal NH3 N compared with monensin.
Molar proportion of acetate was decreased (P = .02) and propionate increased (P =
.01) with ionophore treatment. Consequently, ionophore supplementation depressed
the acetate:propionate ratio (P = .01). In situ degradation rate of soybean meal
(SBM) CP was greater (P = .09) with ionophore treatment, but estimates of SBM
undegradable intake protein were not altered by treatment (P > .25). Microbial
specific activity of net NH3 N release and alpha-amino N degradation were
decreased (P < .04) with ionophores. Based on this study, LP and monensin did not
affect the extent of ruminal degradation of SBM CP but decreased amino acid
deamination.
PMID- 10682820
TI - Influence of the novel urease inhibitor N-(n-butyl) thiophosphoric triamide on
ruminant nitrogen metabolism: I. In vitro urea kinetics and substrate digestion.
AB - Two in vitro digestion experiments were conducted to evaluate the influence of
the novel urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) on in vitro
urea kinetics, substrate digestion, and fermentation characteristics. In Exp. 1,
in vitro incubations were conducted in 50-mL test tubes containing .25 g of
ground fescue hay to which 0, 6.5, 13, 26, or 52 mg of NBPT in a buffered ruminal
fluid innoculum was added. Tubes were incubated in triplicate at 39 degrees C and
replicated on consecutive days, with NH3 N and urea concentrations measured at 0,
10, 30, 60, 120, 240, and 360 min. Samples for VFA analysis were collected at 6
h, and incubations were continued through 48 h to estimate true digestibility
(based on NDF analysis). Increasing the dose of NBPT tended (P < .12) to linearly
depress the rate of urea hydrolysis and decreased (P < .0004) subsequent NH3 N
formation. Although total VFA concentration at 6 h increased linearly (P < .03),
acetate:propionate and estimated true digestibility decreased (P < .01) with
increasing NBPT concentration. In Exp. 2, we compared in vitro urea kinetics and
digestion of forage-only or mixed forage-grain substrates in response to addition
of NBPT. In vitro incubations were conducted in 50-mL test tubes containing
either .5 g of ground fescue hay or .5 g of a ground fescue hay and ground corn
mixture (50:50, DM basis) to which 0, 6.5, 13, 26, or 52 mg of NBPT in a buffered
ruminal fluid innoculum was added. Tubes were incubated in triplicate at 39
degrees C and replicated on consecutive days, with NH3 N and urea concentrations
measured at 0, .5, 1, 2, 4, 8, 12, 24, and 48 h. At 48 h, samples for VFA
analysis were collected and true digestibility (based on NDF analysis) was
estimated. No (P > .10) NBPT dose x substrate interactions were detected.
Increasing the dose of NBPT depressed (P < .003) the rate of urea hydrolysis and
subsequent NH3 N formation, regardless of substrate. Although total VFA
concentration was unaffected (P > .10), the acetate:propionate and estimated true
digestibility decreased (P < .002) with higher NBPT addition. In both
experiments, the rate of urea degradation was not different (P > .20) from zero
for the 26 and 52 mg NBPT treatments, indicating that nearly complete inhibition
of urease had been achieved. We conclude that NBPT can be used to reduce the rate
of NH3 N release from dietary urea and, thereby, offers the potential to improve
nonprotein nitrogen utilization in ruminants.
PMID- 10682821
TI - Influence of the novel urease inhibitor N-(n-butyl) thiophosphoric triamide on
ruminant nitrogen metabolism: II. Ruminal nitrogen metabolism, diet
digestibility, and nitrogen balance in lambs.
AB - Three lamb metabolism experiments were conducted to investigate the effects of
chronic administration of the novel urease inhibitor N (n-butyl) thiophosphoric
triamide (NBPT) on ruminal N metabolism, fermentation, and N balance. In Exp. 1,
ruminally cannulated wethers (n = 28; 45.0 +/- .9 kg) were administered one of
seven doses of NBPT (0 [control], .125, .25, .5, 1, 2, or 4 g of NBPT daily) and
fed a common cracked corn/cottonseed hull-based diet twice daily containing 2%
urea at 2.5% of initial BW for the duration of the 15-d experiment. Overall, NBPT
decreased (linear P < .0001; quadratic P < .001) ruminal urease activity,
resulting in linear increases (P < .0001) in ruminal urea and decreases in
ruminal NH3 N concentrations. However, the detection of an NBPT x day interaction
(d 2 vs 15; P < .01) indicated that this depression in urea degradation
diminished as the experiment progressed. Increasing NBPT linearly decreased (P <
.01) total VFA concentrations on d 2 of the experiment, but it had no effect (P >
.10) on d 15. Increasing NBPT had no effect (P > .10) on DM or ADF
digestibilities, but it linearly decreased (P < .01) N digestibility.
Supplementing NBPT produced a linear increase (P < .05) in urinary N excretion
and a linear decrease (P < .01) in N retention. In Exp. 2, ruminally cannulated
wethers (n = 30; 46.8 +/- .6 kg) were fed one of two basal diets (2.0 vs 1.1%
dietary urea) at 2.5% of initial BW and dosed with either 0 (control), .25, or 2
g of NBPT daily for the duration of the 15-d experiment. There were no NBPT x
dietary urea interactions (P > .10) for Exp. 2. Increasing NBPT depressed (linear
and quadratic P < .0001) ruminal urease activity, producing linear (P < .0001)
increases in urea N and linear decreases in NH3 N in the rumen. As in Exp. 1, an
NBPT x day interaction (P < .05) was noted for urea, NH3 N, and total VFA
concentrations; the maximum response to NBPT occurred on d 2 but diminished by d
15 of the experiment. Administration of NBPT did not influence (P > .10) DM, ADF,
or N digestibilities in Exp. 2. In Exp. 3, wether lambs (n = 30; 26.4 +/- .7 kg)
were subjected to the same treatment regimen as in Exp. 2 for a 14-d N balance
experiment. Although several NBPT x dietary urea interactions (P < .05) were
noted, increasing NBPT did not affect (P > .10) N digestibility. Administration
of NBPT quadratically increased (P < .10) urinary N excretion, producing a linear
decrease (P < .05) in N retention. These results suggest that although NBPT is
capable of inhibiting ruminal urease short-term, the ruminal microflora may be
capable of adapting to chronic NBPT administration, thereby limiting its
practical use in improving the utilization of dietary urea.
PMID- 10682822
TI - Metabolize methionine and lysine requirements of growing cattle.
AB - Two growth studies were conducted to determine the Met and Lys requirements of
growing cattle. In each 84-d trial, steer calves were fed individually diets
containing 44% sorghum silage, 44% corn cobs, and 12% supplement (DM basis) at an
equal percentage of BW. In Trial 1, 95 crossbred steers (251 kg) were
supplemented with urea or meat and bone meal (MBM). Incremental amounts of rumen
protected Met were added to MBM to provide 0, .45, .9, 1.35, 3, and 6 g/d
metabolizable Met. In Trial 2, 60 steers (210 kg) were supplemented with urea or
corn gluten meal (CGM). Incremental amounts of rumen-protected Lys were added to
CGM to provide 0, 1, 2, 3, 4, 5, 6, 8, and 10 g/d metabolizable Lys.
Supplementation with MBM and CGM increased the supply of metabolizable protein to
the animal. Steers fed MBM plus 0 Met gained 49 g/d more than steers fed urea,
whereas steers fed CGM plus 0 Lys gained 150 g/d more than steers fed urea.
Supplementation of rumen-protected Met and Lys improved ADG in steers fed MBM and
CGM, respectively (P < .10). Nonlinear analysis, comparing gain vs supplemental
Met and Lys intake, predicted supplemental Met and Lys requirements of 2.9 and .9
g/d, respectively. This amount of additional Met promoted .13 kg/ d gain greater
than MBM alone, and this amount of additional Lys promoted .10 kg/d gain greater
than the CGM alone. Metabolizable Met and Lys requirements were predicted from
Level 1 of NRC (1996) calculated metabolizable protein supply, amino acid
analysis of abomasal contents, and the maximum response to supplemental AA.
Steers gaining .39 kg/d required 11.6 g/ d Met or 3. 1% of the metabolizable
protein requirement, whereas steers gaining .56 kg/d required 22.5 g/d Lys or
5.7% of the metabolizable protein requirement.
PMID- 10682823
TI - Evaluation of feather meal as a source of sulfur amino acids for growing steers.
AB - In situ and digestion studies were conducted to evaluate feather meal (FTH),
blood meal (BM), and meat and bone meal (MBM) for escape protein content, amino
acid composition of the escape protein, true protein digestibility, and
digestibility of the individual amino acids. Following 12 h of ruminal
incubation, escape protein values were 73.5, 92.4, and 60.8% of CP for FTH, BM,
and MBM, respectively. Blood meal and MBM were poor sources of sulfur amino acids
(SAA), whereas FTH was a good source. Most of the SAA of FTH, however, was Cys,
with very little Met. True protein digestibilities were not different for the
protein sources (P > .15), ranging from 86.7 to 94.0% of the CP. However,
digestibilities of the individual amino acids were quite different. Two growth
studies were conducted to evaluate FTH as a source of SAA for growing cattle. The
first study used 120 steers (228 +/- 15 kg) supplemented with urea, MBM, MBM plus
1% FTH, or MBM plus 2% FTH. Additionally, incremental amounts of rumen-protected
Met were added to treatments containing MBM. Supplementation of MBM increased (P
< .05) ADG compared with the urea control. Addition of FTH to MBM resulted in a
linear (P < .01) increase in ADG. However, addition of rumen-protected Met to MBM
plus FTH treatments further improved gains. Although FTH is an effective source
of SAA, Met probably was first-limiting. The second study used 90 steers (243 +/-
18 kg) supplemented with BM plus incremental amounts of SAA from either FTH or
rumen-protected Met. Addition of SAA improved ADG compared with BM alone (P <
.05). Rumen-protected Met as a source of SAA improved ADG compared with FTH (P <
.05). The SAA from FTH promoted a gain response equal to 50% of the response
obtained with rumen-protected Met. Formulation of ruminant diets for
metabolizable amino acids must account for escape value and digestibility of each
individual amino acid. Feather meal is an effective source of SAA; however, Cys
supplies over five times the amount supplied by Met.
PMID- 10682824
TI - Changes in postprandial plasma and extracellular and ruminal fluid volumes in
wethers fed or unfed for 72 hours.
AB - Postprandial shifts in body water compartments might limit feed intake by
ruminants, especially when an animal becomes partially dehydrated during
transportation or other periods of water deprivation. This experiment was
conducted to determine the effects of feed and water deprivation on postprandial
changes in body water compartments in wethers. Hampshire wethers (n = 8; average
BW 42 +/- 2 kg) were used in a crossover design. During each period, four wethers
were limit-fed (540 g DM/d: FED) and four were deprived of feed and water for 72
h (DEPRIVED). Wethers were infused i.v. with Evans blue and sodium thiosulfate
and intraruminally with Cr- or Co-EDTA, after which blood and ruminal samples
were collected for the next 4 h. All wethers were then fed 540 g of feed DM, and
infusions were repeated 30 min after feeding. Body water compartment volumes were
determined with linear regression using plasma concentrations of Evans blue
(plasma volume), and sodium thiosulfate (extracellular volume), and using ruminal
fluid concentrations of Cr or Co. Feed and water deprivation decreased (P < .01)
extracellular water space but did not affect plasma or ruminal water space. After
feeding, extracellular water space decreased (P < .01) and ruminal volume
increased (P < .05) in the FED and DEPRIVED wethers. Plasma pools of Na, K, and
Mg were not affected by feeding in FED wethers but decreased (P < .05) in
DEPRIVED wethers. The increase in ruminal fluid pools of Na, K, and Mg were
greater (P < .05) in FED than in DEPRIVED wethers. These results indicate that
abnormal water and electrolyte shifts may be factors partially responsible for
the decreased feed intake by ruminants subjected to transportation or feed and
water deprivation stress.
PMID- 10682825
TI - Effects of supplemental degradable intake protein on utilization of medium- to
low-quality forages.
AB - Three independent experiments were conducted each using 16 ruminally fistulated
beef steers fed bermudagrass (8.2% CP, 71% NDF; Exp. 1), bromegrass (5.9% CP, 65%
NDF; Exp. 2), or forage sorghum (4.3% CP, 60% NDF; Exp. 3) hays to evaluate the
effects of increasing level of supplemental degradable intake protein (DIP) on
forage utilization. In each experiment, steers were blocked by weight and
assigned to one of four treatments, and hay was offered to each steer at 130% of
average voluntary intake for the preceding 5-d period. Supplemental DIP (sodium
caseinate) was placed in the rumen at 0700, immediately before feeding forage.
Levels of DIP supplementation were .041, .082, and .124% BW; the control received
no supplemental DIP. Following a 10-d adaptation, intake and total fecal output
were measured for 7 d. In Exp. 1, neither forage OM intake (FOMI) nor fiber (NDF)
digestion were influenced (P > or = .20) by increasing level of DIP
supplementation. The DIP supplied by the bermudagrass hay was estimated to be
8.2% of the total digestible OM intake (TDOMI) for control steers. In Exp. 2,
increasing level of supplemental DIP did not affect (P > or = .26) FOMI but
tended to increase total OM intake linearly (TOMI; P = .10). The tendency for a
rise in TOMI coupled with a slight numeric increase in digestion resulted in an
increase (linear; P = .06) in TDOMI. In the treatment group in which the maximum
TDOMI was observed (supplemental DIP treatment of .082% BW), total DIP intake
constituted approximately 9.8% of the TDOMI. In Exp. 3, FOMI, TOMI, organic
matter digestion (OMD), and TDOMI were improved (P < .01) by increasing amounts
of supplemental DIP. Although there was some evidence of a tendency for a
decrease in the magnitude of change in TDOMI in response to increasing DIP
supplementation, a clear plateau was not achieved with the levels of supplement
provided. When the highest level of supplemental DIP was fed, DIP constituted
approximately 12.8% of the TDOMI. In conclusion, significant variation was
observed among forage in the amount of DIP needed to maximize intake and
digestion when expressed in relationship to the digestible OM.
PMID- 10682826
TI - Determination of the methionine requirement of growing double-muscled Belgian
blue bulls with a three-step method.
AB - The three-step technique was used to determine the requirements of total amino
acids (TAA) and the first-limiting amino acid (AA) in growing double-muscled
Belgian Blue bulls (BBb). In Exp. 1, three double-muscled BBb weighing initially
306 +/- 28 kg received a basal diet consisting of 30% meadow hay and 70%
concentrate that was poor in digestible protein but had adequate NE because of
continuous infusion of dextrose into the duodenum. The intestinal apparent
digestibility of essential AA (EAA) was defined according to their duodenal and
ileal flows. It averaged 72% but varied between 60% for Met and 79% for Arg. In
Exp. 2, five double-muscled BBb (334 +/- 22 kg) received the same diet
supplemented with duodenal infusions of dextrose and four doses of Na-caseinate
(28, 56, 84, and 112% of intestinal digestible dietary AA) in a 4 x 4 Latin
square design with one additional animal. Nitrogen retention for the basal diet
alone and the four increasing supplements of Na-caseinate reached 49, 61, 70, 80,
and 86 g/d, respectively. Nitrogen utilization improved from 34.3% without Na
caseinate supplementation to a maximum of 40.6%, with the third dose supplying
788 g/d of apparently digestible AA. Based on patterns of plasma concentrations,
Met, Phe, and Arg were probably the limiting AA when animals optimized N
utilization. In Exp. 3, six double-muscled BBb (315 +/- 25 kg) fed the basal diet
received duodenal infusions of dextrose and AA, equivalent to the third dose in
Exp. 2, except for digestible Met (9.3, 14.4, 18.4, 22.4, 26.4, and 30.4 g/d) in
a 6 x 6 Latin square design. The Met requirement was close to 26.4 g/d on the
basis of N retention.
PMID- 10682827
TI - Rapid communication: localization of POU1F1 to bovine, ovine, and caprine 1q21
22.
PMID- 10682828
TI - Summary of Notifiable Diseases, United States, 1998.
AB - The MMWR Summary of Notifiable Diseases, United States, 1998 contains summary
tables of the official statistics for the reported occurrence of nationally
notifiable diseases in the United States for 1998. These statistics are collected
and compiled from reports to the National Notifiable Diseases Surveillance System
(NNDSS), which is operated by CDC in collaboration with the Council of State and
Territorial Epidemiologists (CSTE).
PMID- 10682829
TI - Nuclear wavepacket motion producing a reversible charge separation in bacterial
reaction centers.
AB - The excitation of bacterial reaction centers (RCs) at 870 nm by 30 fs pulses
induces the nuclear wavepacket motions on the potential energy surface of the
primary electron donor excited state P*, which lead to the fs oscillations in
stimulated emission from P* [M.H. Vos, M.R. Jones, C.N. Hunter, J. Breton, J.-C.
Lambry and J.-L. Martin (1994) Biochemistry 33, 6750-6757] and in Qy absorption
band of the primary electron acceptor, bacteriochlorophyll monomer B(A) [A.M.
Streltsov, S.I.E. Vulto, A.Y. Shkuropatov, A.J. Hoff, T.J. Aartsma and V.A.
Shuvalov (1998) J. Phys. Chem. B 102, 7293-7298] with a set of fundamental
frequencies in the range of 10-300 cm(-1). We have found that in pheophytin
modified RCs, the fs oscillations with frequency around 130 cm(-1) observed in
the P*-stimulated emission as well as in the B(A) absorption band at 800 nm are
accompanied by remarkable and reversible formation of the 1020 nm absorption band
which is characteristic of the radical anion band of bacteriochlorophyll monomer
B(A)-. These results are discussed in terms of a reversible electron transfer
between P* and B(A) induced by a motion of the wavepacket near the intersection
of potential energy surfaces of P* and P+B(A)-, when a maximal value of the
Franck-Condon factor is created.
PMID- 10682830
TI - Induction of tcI 7, a gene encoding a beta-subunit of proteasome, in tobacco
plants treated with elicitins, salicylic acid or hydrogen peroxide.
AB - We previously isolated, by differential display and 5' RACE (rapid amplification
of cDNA ends), cDNAs corresponding to genes activated following cryptogein
treatment of tobacco cell suspensions, among them tcI 7 (tcI for tobacco
cryptogein Induced), a gene encoding a beta-subunit of proteasome. Here, we
report that tcl 7 was up-regulated in tobacco plants treated with elicitins
(cryptogein and parasiticein) that have been shown to induce a systemic acquired
resistance (SAR). Moreover, subsequent inoculation of tobacco with the pathogen
Phytophthora parasitica var. nicotianae (Ppn) was shown to induce an additional
activation of tcI 7 in tobacco plants pretreated with cryptogein. We also showed
an up-regulation of tcI 7 by salicylic acid (SA). Moreover, accumulation of tcI 7
transcripts after treatment with cryptogein or with SA only occurred in NahG 9
tobacco plants that do not express the salicylate hydroxylase and thus are able
to accumulate SA and develop a SAR. Suppressed accumulation of tcI 7 transcripts
in NahG 8+ tobacco plants after cryptogein or SA treatment correlated with the
loss of SAR. H2O2 was also shown to up-regulate tcI 7 in tobacco plants. Using
gene walking by PCR we cloned and sequenced the 5' flanking region of tcI 7
containing hypothetical regulatory sequences, especially myb and NF-kappaB boxes,
that could be responsible for the regulation of tcI 7 by salicylic acid and H2O2
respectively.
PMID- 10682831
TI - P-glycoprotein is localized in caveolae in resistant cells and in brain
capillaries.
AB - A significant proportion of P-glycoprotein (P-gp) and caveolin was co-localized
in caveolae isolated from resistant (CH(R)C5) cells overexpressing P-gp and from
drug-sensitive Chinese hamster ovary cells (AuxB1). The proportion of P-gp and
caveolin associated with caveolar microdomains was higher in CH(R)C5 cells grown
in the presence of P-gp substrates (cyclosporin A or colchicine) than in
untreated CH(R)C5 cells. Coimmunoprecipitation of P-gp and caveolin from CH(R)C5
lysates suggests that there is a physical interaction between them. Furthermore,
co-localization of P-gp and caveolin was found in caveolae from brain
capillaries, indicating that this association also takes place in vivo.
PMID- 10682832
TI - A high affinity nitrate transport system from Chlamydomonas requires two gene
products.
AB - A nitrate-regulated cluster of genes involved in nitrate transport and
assimilation has been identified in Chlamydomonas reinhardtii. Mutant strains of
the alga, which are defective in some aspect of transport and assimilation have
been used to assign functions to these genes. This analysis has suggested that
two gene products are necessary to obtain a functional high affinity nitrate
system in Chlamydomonas [Quesada et al. (1994) Plant J. 5, 407-419]. In this
paper we have tested this hypothesis by injecting Xenopus oocytes with mRNA
prepared from these two cDNAs, Nrt2;1 and Nar2, and then assaying the oocytes for
nitrate transport activity. Oocytes injected with single types of mRNA did not
show any nitrate transport activity. Furthermore, Nar2 mRNA was toxic to oocytes,
with nearly 60%, of the oocytes dead 3 days after the injection. However, when
oocytes were injected with a mixture of two mRNAs prepared from Nrt2;1 and Nar2,
a high affinity nitrate transport activity could be measured. However, the Km for
nitrate of this transport system was 28 microM which is higher than the value of
1.6 microM which had been obtained by the analysis of mutant phenotypes. The pH
dependence of the nitrate-elicited currents was consistent with a proton
cotransport mechanism. These results prove that two gene products are required to
produce a functional high affinity nitrate transport system and that this process
does not involve transcriptional regulation.
PMID- 10682833
TI - Potential role for triglycerides in signal transduction.
AB - We previously reported that endothelin-1 or platelet-derived growth factor
promoted in aortic smooth muscle cells a rapid hydrolysis of 1-O-alkyl-2-acyl-sn
glycero-3-phosphoethanolamine (alkyl-PE) which was immediately converted into 1-O
alkyl-2,3-diacyl-sn-glycerol (alkyl-TG) within 5 s or 60 s respectively [C.
Comminges et al. (1996) Biochem. Biophys. Res. Commun. 220, 1008-1013 and C.
Comminges et al. (1997) Biochim. Biophys. Acta 1355, 69-80]. In this study, we
show that this alkyl-PE hydrolysis is triggered by a transient activation of a
specific phospholipase C (PLC) regulated by pertussis toxin-sensitive
heterotrimeric G-proteins. Moreover, this PLC can be triggered through a Ca2+
influx depending on L-type Ca2+ channel activation, as suggested by the use of a
specific 'activator' S(-)-BayK 8644 and of selective inhibitors such as
nimodipine. Interestingly, low concentrations (10(-8)-10(-7)M) of alkyl-TG block
the opening of L-type Ca2+ channels, whereas identical concentrations of DG do
not alter L-type Ca2+ channels. This study thus unravels a hitherto unrecognized
signaling pathway generating alkyl-TG as a novel lipid second messenger,
potentially acting as a negative feedback regulator of L-type Ca2+ channels.
PMID- 10682834
TI - Functional association between the nef gene product and gag-pol region of HIV-1.
AB - Nef gene function is diverse among virus isolates of primate immunodeficiency
viruses. We found differential effects of nef mutation on the virus replication
between two HIV-1 clones, NL432 and LAI. The nef mutation in NL432 affected the
infectivity more severely compared with that in LAI, although the Nef functions
of both clones were comparable. Analysis with a series of chimeric viruses
between NL432 and LAI revealed that the gag-pol region was responsible for the
differential effect of nef mutation. The functional association between Nef and
gag-pol suggested that one of the potential targets of Nef was located within the
gag-pol region.
PMID- 10682835
TI - cDNA-derived amino acid sequence of acetoacetyl-CoA synthetase from rat liver.
AB - In order to examine the primary structure of acetoacetyl-CoA synthetase
(acetoacetate-CoA ligase, EC 6.2.1.16; AA-CoA synthetase), the cDNA clone
encoding this enzyme has been isolated from the cDNA library which was prepared
from the liver of rat fed a diet supplemented with 4% cholestyramine and 0.4%
pravastatin for 4 days. Nucleotide sequence analysis of cloned cDNA revealed that
AA-CoA synthetase of rat liver contains an open reading frame of 2019
nucleotides, and the deduced amino acid sequence (672 amino acid residues) bears
25.0 and 38.9% homologies with acetyl-CoA synthetases of Saccharomyces cerevisiae
and Archaeoglobus fulgidus, respectively.
PMID- 10682836
TI - Identification of a cDNA encoding an active asparaginyl endopeptidase of
Schistosoma mansoni and its expression in Pichia pastoris.
AB - Asparaginyl endopeptidases, or legumains, are a recently identified family of
cysteine-class endopeptidases. A single gene encoding a Schistosoma mansoni
asparaginyl endopeptidase (a.k.a. Sm32 or schistosome legumain) has been
reported, but by sequence homology it would be expected to yield an inactive
product as the active site C197 had been replaced by N. We now describe a new S.
mansoni gene in which C197 is present. Both gene products were expressed in
Pichia pastoris. Autocatalytic processing to fully active C197 Sm32 occurred at
acid pH. In contrast, N197 Sm32 was not processed and this is consistent with the
hypothesis that C197 is essential for catalysis. This was confirmed by mutation
of N197 to C and re-expression in Pichia. The availability of recombinant active
Sm32 allows detailed analysis of its catalytic mechanism and its function(s) in
the biology of this important human parasite.
PMID- 10682837
TI - Two Sox9 messenger RNA isoforms: isolation of cDNAs and their expression during
gonadal development in the frog Rana rugosa.
AB - Sox is a family of SRY-related testis-determining genes. We have isolated two
different mRNA isoforms of the frog Sox9 gene from adult frog testis cDNAs. One
form (Sox9 alpha) encodes a 482 amino acid protein containing the HMG box,
whereas the other form (Sox9 beta), which completely lacks the HMG box, is a
truncated 265 amino acid protein of Sox9 alpha. Sox9 alpha is 82% similar to
mouse, 86% to chicken, and 77% to trout Sox9 at the amino acid level. Sox9
expression was upregulated in embryos after stage 16, and was seen in both
developing testes and ovaries. The size of Sox9 transcripts was determined to be
7.8 knt by Northern blot analysis. In addition, Sox9 alpha expression was found
prominently in the testis and brain among various tissues of adult frogs
examined, and was considerably higher than Sox9 beta. The fact that Sox9 is
expressed in both sexes suggests that this gene is involved in gonadal
development of male and female frogs. This is dissimilar to the pattern in birds
and mammals, in which Sox9 expression is male-specific.
PMID- 10682838
TI - Key amino acids of vasopressin V1a receptor responsible for the species
difference in the affinity of OPC-21268.
AB - A non-peptide, vasopressin V1a receptor-selective antagonist, OPC-21268,
exhibited a markedly higher affinity for the rat V1a receptor (Ki = 380 nM) than
for the human V1a receptor (Ki = 140 microM). To delineate the region responsible
for the high affinity binding of OPC-21268 for the rat V1a receptor, we have
constructed a series of chimeric human and rat V1a receptors, and examined the
chimeric and point-mutated receptors by competitive radioligand binding analysis.
The results showed that the transmembrane domain (TMD) VI-VII of the vasopressin
V1a receptor, in particular the amino acid residue Ala-342 in TMD VII, is the
major component conferring the rat-selective binding of OPC-21268 to the V1a
receptor.
PMID- 10682839
TI - Unusual FTIR and EPR properties of the H2-activating site of the cytoplasmic NAD
reducing hydrogenase from Ralstonia eutropha.
AB - Soluble NAD-reducing [NiFe]-hydrogenase (SH) from Ralstonia eutropha (formerly
Alcaligenes eutrophus) has an infrared spectrum with one strong band at 1956 cm(
1) and four weak bands at 2098, 2088, 2081 and 2071 cm(-1) in the 2150-1850 cm(
1) spectral region. Other [NiFe]-hydrogenases only show one strong and two weak
bands in this region, attributable to the NiFe(CN)2(CO) active site. The position
of these three bands is highly sensitive to redox changes of the active site. In
contrast, reduction of the SH resulted in a shift to lower frequencies of the
2098 cm(-1) band only. These and other properties prompted us to propose the
presence of a Ni(CN)Fe(CN)3(CO) active site.
PMID- 10682840
TI - Gene structure of human cholecystokinin (CCK) type-A receptor: body fat content
is related to CCK type-A receptor gene promoter polymorphism.
AB - The transcriptional start site of the human cholecystokinin (CCK)-A receptor gene
was determined by the Capsite Hunting method. Two sequence changes were detected,
a G to T change in nucleotide -128, and an A to G change in nucleotide -81. The
homozygote (T/T, G/G) was detected in 25 of 1296 individuals (1.9%) in the cohort
study. This polymorphism showed a significantly higher percent body fat and
higher levels of serum insulin and leptin, compared with wild type and
heterozygotes. Our study provided the possibility that polymorphism in the
promoter region of the CCK-A receptor gene may be one of genetic factors
affecting fat deposition.
PMID- 10682841
TI - Mutational analysis of phosphorylation sites in the Dictyostelium myosin II tail:
disruption of myosin function by a single charge change.
AB - The dynamic assembly/disassembly of non-muscle myosin II filaments is critical
for the regulation of enzymatic activities and localization. Phosphorylation of
three threonines, 1823, 1833 and 2029, in the tail of Dictyostelium discoideum
myosin II has been implicated in control of myosin filament assembly. By
systematically replacing the three threonines to aspartates, mimicking a
phosphorylated residue, we found that position 1823 is the most critical one for
the regulation of myosin filament formation and in vivo function. Surprisingly, a
single charge change is able to perturb filament formation and in vivo function
of myosin II.
PMID- 10682842
TI - Requirements for alternative forms of the activator domain, P5abc, in the
Tetrahymena ribozyme.
AB - The role of P5abc domain of the Tetrahymena LSU self-splicing Group I intron is
to enhance the activity of the intron via tertiary interactions involving A-rich
bulge and terminal loops L5b and L5c. We constructed and examined alternative
forms of the domain that accelerate the ribozymatic reaction. The results
indicate that the characteristic structure of P5c subdomain plays an important
role by forming L2xL5c interaction (P14) and that the region flanking P5c
subdomain can be significantly mutable without much affecting the activity of the
ribozyme.
PMID- 10682843
TI - Progesterone is a cell death suppressor that downregulates Fas expression in rat
corpus luteum.
AB - In female rats, apoptotic cell death in the corpus luteum is induced by the
prolactin (PRL) surge occurring in the proestrous afternoon during the estrous
cycle. We have previously shown that this luteolytic action of PRL is mediated by
the Fas/Fas ligand (FasL) system. During pregnancy or pseudopregnancy, apoptosis
does not occur in the corpus luteum. Progesterone (P4), a steroid hormone
secreted from luteal steroidogenic cells, attenuated PRL-induced apoptosis in
cultured luteal cells in a dose-dependent manner. P4 significantly decreased the
expression of mRNA of Fas, but not FasL, in cultured luteal cells prepared from
both proestrous and mid-pseudopregnant rats. These data indicate that P4
suppresses PRL-induced luteal cell apoptosis via reduction of the expression
level of Fas mRNA in the corpus luteum, suggesting that P4 acts as an important
factor that can change the sensitivity of corpus luteum to PRL.
PMID- 10682844
TI - Closed loops of nearly standard size: common basic element of protein structure.
AB - By screening the crystal protein structure database for close Calpha-Calpha
contacts, a size distribution of the closed loops is generated. The distribution
reveals a maximum at 27+/-5 residues, the same for eukaryotic and prokaryotic
proteins. This is apparently a consequence of polymer statistic properties of
protein chain trajectory. That is, closure into the loops depends on the
flexibility (persistence length) of the chain. The observed preferential loop
size is consistent with the theoretical optimal loop closure size. The mapping of
the detected unit-size loops on the sequences of major typical folds reveals an
almost regular compact consecutive arrangement of the loops. Thus, a novel basic
element of protein architecture is discovered; structurally diverse closed loops
of the particular size.
PMID- 10682845
TI - p97 ATPase, an ATPase involved in membrane fusion, interacts with DNA unwinding
factor (DUF) that functions in DNA replication.
AB - DNA unwinding factor (DUF) unwinds duplex DNA and is supposed to function in DNA
replication in Xenopus egg extracts. Here we report the isolation and analysis of
a DUF-interacting factor. By immunoprecipitation, we found that p97 ATPase (p97)
interacts with DUF in Xenopus egg extracts. This interaction was confirmed by the
in vitro binding of purified p97 with DUF. When sperm chromatin was added to
Xenopus egg extracts to construct nuclei active in DNA replication, p97 was
incorporated into the nuclei. These data suggest that the complex of DUF and p97
may function in DNA replication.
PMID- 10682846
TI - Chitosan-induced phospholipase A2 activation and arachidonic acid mobilization in
P388D1 macrophages.
AB - We have found that chitosan, a polysaccharide present in fungal cell walls, is
able to activate macrophages for enhanced mobilization of arachidonic acid in a
dose- and time-dependent manner. Studies aimed at identifying the intracellular
effector(s) implicated in chitosan-induced arachidonate release revealed the
involvement of the cytosolic Group IV phospholipase A2 (PLA2), as judged by the
inhibitory effect of methyl arachidonoyl fluorophosphonate but not of bromoenol
lactone. Interestingly, priming of the macrophages with lipopolysaccharide
renders the cells more sensitive to a subsequent stimulation with chitosan, and
this enhancement is totally blocked by the secretory PLA2 inhibitor 3-(3
acetamide)-1-benzyl-2-ethylindolyl-5-oxy-propanesulfonic acid (LY311727).
Collectively, the results of this work establish chitosan as a novel macrophage
activating factor that elicits AA mobilization in P388D1 macrophages by a
mechanism involving the participation of two distinct phospholipases A2.
PMID- 10682847
TI - Activation of recombinant proenteropeptidase by duodenase.
AB - Duodenase, a serine proteinase from bovine Brunner's (duodenal) glands that was
predicted to be a natural activator of enteropeptidase zymogen, cleaves and
activates recombinant single-chain bovine proenteropeptidase (kcat/Km = 2700 M(
1) s(-1)). The measured rate of proenteropeptidase cleavage by duodenase was
about 70-fold lower compared with the rate of trypsin-mediated cleavage of the
zymogen. The role of duodenase is supposed to be the primary activator of
proenteropeptidase maintaining a certain level of active enteropeptidase in the
duodenum. A new scheme of proteolytic activation cascade of digestive proteases
is discussed.
PMID- 10682848
TI - Role of the highly conserved Asp-Arg-Tyr motif in signal transduction of the CB2
cannabinoid receptor.
AB - The DRY motif, at the junction of transmembrane helix 3 and intracellular loop 2
of G protein-coupled receptors, is highly conserved. Mutations were introduced
into the CB2 cannabinoid receptor to study the role of this motif in CB2
signaling. D mutations (DRY130-132AAA and D130A) markedly reduced binding of
cannabinoid agonists, while no significant reduction was observed with R131A or
Y132A. Mutating R (R131A) only partially reduced, and mutating Y (Y132A) more
efficiently reduced the cannabinoid-induced inhibition of adenylyl cyclase. Thus,
in CB2, D130 is involved in agonist binding, whereas Y seems to have a role in
receptor downstream signaling.
PMID- 10682849
TI - Virus-induced permeability transition in mitochondria.
AB - Isolated rat liver mitochondria undergo permeability transition after
supplementation with a suspension of tobacco mosaic virus. Four mitochondrial
parameters proved the opening of the permeability transition pore in the inner
mitochondrial membrane: increased oxygen consumption, collapse of the membrane
potential, release of calcium ions from mitochondria, and high amplitude
mitochondrial swelling. All virus-induced changes in mitochondria were prevented
by cyclosporin A. These effects were not observed if the virus was treated with
EGTA or disrupted by heating. Protein component of the virus particle in the form
of 20S aggregate A-protein, or helical polymer, as well as supernatant of the
heat-disrupted virus sample, had no effect on mitochondrial functioning. Electron
microscopy revealed the direct interaction of the virus particles with isolated
mitochondria. The possible role of the mitochondrial permeability transition pore
in virus-induced apoptosis is discussed.
PMID- 10682850
TI - Characterization of the c-specific promoter of the gene encoding human endothelin
converting enzyme-1 (ECE-1).
AB - Human ECE-1 is expressed in four isoforms with different tissue distribution and
its mRNA and protein levels are altered under certain pathophysiological
conditions. To investigate the transcriptional regulation of ECE-1, we studied
the regulatory region of ECE-1c, the major ECE-1 isoform. A genomic clone
comprising the complete human ECE-1 gene including the putative ECE-1c-specific
promoter was obtained. Up to 968 bp upstream of the putative c-specific
translation initiation start codon and several serial deletion mutants were
subcloned into a reporter vector and transfected into endothelial (BAEC,
EA.hy926, ECV304) and epithelial (MDA MB435S, MCF7) cells, showing very strong
promoter activity in comparison to the SV40 promoter and to the previously
described ECE-1a and 1b promoters. Transfection of serial deletion mutants
indicated two positive regulatory regions within the promoter (-142/-240 and
240/490) likely involved in binding GATA and ETS transcription factors. RNase
protection assay (RPA) and 5'-RACE revealed multiple transcriptional start sites
located at about -110, -140 and -350 bp. Site-directed mutagenesis demonstrated a
crucial role for the E2F cis-element for basal ECE-1c promoter activity.
Additionally, we found a correlation between isoform-specific ECE-1 mRNA levels
and corresponding ECE-1a, 1b, 1c promoter activities.
PMID- 10682851
TI - Mutagenic studies on human protein disulfide isomerase by complementation of
Escherichia coli dsbA and dsbC mutants.
AB - Protein disulfide isomerase (PDI) exhibits both an oxido-reductase and an
isomerase activity on proteins containing cysteine residues. These activities
arise from two active sites, both of which contain pairs of redox active
cysteines. We have developed two simple in vivo assays for these activities of
PDI, based on the demonstration that PDI can complement both a dsbA mutation and
a dsbC mutation when expressed to the periplasm of Escherichia coli. We
constructed a variety of mutants in and around the active sites of PDI and
analysed them using these complementation assays. Our analysis showed that the
active site amino acid residues have a major role in determining the activities
exhibited by PDI, particularly the N-terminal cysteine of the N-terminal active
site. The roles of the histidine residue at position 38 and the glutamic acid
residue at position 30 were also studied using these assays. The results show
that these two in vivo assays should be useful for rapid screening of mutants in
PDI prior to purification and detailed biochemical analysis.
PMID- 10682852
TI - The effect of reactive oxygen species generated from the mitochondrial electron
transport chain on the cytochrome c oxidase activity and on the cardiolipin
content in bovine heart submitochondrial particles.
AB - The effect of reactive oxygen species (ROS), produced by the mitochondrial
respiratory chain, on the activity of cytochrome c oxidase and on the cardiolipin
content in bovine heart submitochondrial particles (SMP) was studied. ROS were
produced by treatment of succinate-respiring SMP with antimycin A. This treatment
resulted in a large production of superoxide anion, measured by epinephrine
method, which was blocked by superoxide dismutase (SOD). Exposure of SMP to
mitochondrial mediated ROS generation, led to a marked loss of cytochrome c
oxidase activity and to a parallel loss of cardiolipin content. Both these
effects were completely abolished by SOD+catalase. Added cardiolipin was able to
almost completely restore the ROS-induced loss of cytochrome c oxidase activity.
No restoration was obtained with peroxidized cardiolipin. These results
demonstrate that mitochondrial mediated ROS generation affects the activity of
cytochrome c oxidase via peroxidation of cardiolipin which is needed for the
optimal functioning of this enzyme complex. These results may prove useful in
probing molecular mechanism of ROS-induced peroxidative damage to mitochondria
which have been proposed to contribute to aging, ischemia/reperfusion and chronic
degenerative diseases.
PMID- 10682853
TI - Expression of GIRK (Kir3.1/Kir3.4) channels in mouse fibroblast cells with and
without beta1 integrins.
AB - G protein-activated K+ channel (GIRK) subunits possess a conserved extracellular
integrin-binding motif (RGD) and bind directly to beta1 integrins. We expressed
GIRK1/GIRK4 channels labeled with green fluorescent protein in fibroblast cell
lines expressing or lacking beta1 integrins. Neither plasma membrane localization
nor agonist-evoked GIRK currents were affected by the absence of beta1 integrins
or by incubation with externally applied RGD-containing peptide. Mutation of the
aspartate (D) of RGD impaired currents, GIRK glycosylation, and membrane
localization, but the interaction with beta1 integrins remained intact. Thus,
beta1 integrins are not essential for functional GIRK expression; and the GIRK
integrin interactions involve structural elements other than the RGD motif.
PMID- 10682854
TI - NMR structure of the channel-former zervamicin IIB in isotropic solvents.
AB - Spatial structure of the membrane channel-forming hexadecapeptide, zervamicin
IIB, was studied by NMR spectroscopy in mixed solvents of different polarity
ranging from CDCl3/CD3OH (9:1, v/v) to CD3OH/H2O (1:1, v/v). The results show
that in all solvents used the peptide has a very similar structure that is a bent
amphiphilic helix with a mean backbone root mean square deviation (rmsd) value of
ca. 0.3 A. Side chains of Trp1, Ile2, Gln3, Ile5 and Thr6 are mobile. The results
are discussed in relation to the validity of the obtained structure to serve as a
building block of zervamicin IIB ion channels.
PMID- 10682855
TI - Isolation and expression of a novel alternatively spliced mu opioid receptor
isoform, MOR-1F.
AB - The MOR-1 gene is large, with a recent study reporting nine exons spanning 250 kb
which combine to yield six different mu opioid receptor splice variants. We now
report the isolation of exon 10, which is contained within yet another splice
variant, MOR-1F, which is composed of exons 1, 2, 3, 10, 6, 7, 8 and 9. Exon 10
comprises 186 bp which predict a unique 58 amino acid sequence extending beyond
exon 3. It has been mapped between exons 4 and 6 and has flanking consensus
splice sequences. On Northern blot analysis, the MOR-1F mRNA is smaller than the
other MOR-1 mRNAs. When expressed in CHO cells, MOR-1F binds the mu opioid
radioligand [3H]DAMGO with high affinity (K(D) = 1.04+/-0.03 nM). Competition
studies demonstrated the selectivity of the variant for mu opioid ligands,
supporting its classification within the mu opioid receptor family.
PMID- 10682856
TI - Spin label EPR structural studies of the N-terminus of alpha-spectrin.
AB - Spectrin, a vital component in human erythrocyte, is composed of alpha- and beta
subunits, which associate to form (alphabeta)2 tetramers. The tetramerization
site is believed to involve the alpha-spectrin N-terminus and the beta-spectrin C
terminus. Abnormal interactions in this region may lead to blood disorders. It
has been proposed that both termini consist of partial structural domains and
that tetramerization involves the association of these partial domains. We have
studied the N-terminal region of a model peptide for alpha-spectrin by making a
series of double spin-labeled peptides and studying their dipolar interaction by
electron paramagnetic resonance methods. Our results indicate that residues 21-42
of the N-terminus region exhibit an alpha-helical conformation, even in the
absence of B-spectrin.
PMID- 10682857
TI - Myosin light chain phosphorylation-dependent modulation of volume-regulated anion
channels in macrovascular endothelium.
AB - The Rho/Rho-associated kinase (ROK) pathway has been shown to modulate volume
regulated anion channels (VRAC) in cultured calf pulmonary artery endothelial
(CPAE) cells. Since Rho/ROK can increase myosin light chain phosphorylation, we
have now studied the effects of inhibitors of myosin light chain kinase (MLCK) or
myosin light chain phosphatase (MLCP) on VRAC in CPAE. Application of ML-9, an
MLCK inhibitor, inhibited VRAC, both when applied extracellularly or when
dialyzed into the cell. A similar inhibitory effect was obtained by dialyzing the
cells with AV25, a specific MLCK inhibitory peptide. Conversely, NIPP1(191-210),
an MLCP inhibitory peptide, potentiated the activation of VRAC by a 25% hypotonic
stimulus. These data indicate that activation of VRAC is modulated by MLC
phosphorylation.
PMID- 10682858
TI - pH control of the plant outwardly-rectifying potassium channel SKOR.
AB - SKOR, an Arabidopsis depolarisation-activated K+-selective channel, was expressed
in Xenopus oocytes, and external and internal pH effects were analysed. Internal
pH was manipulated by injections of alkaline or acidic solutions or by acid load
from acetate-containing medium. An internal pH decrease from 7.4 to 7.2 induced a
strong (ca. 80%) voltage-independent decrease of the macroscopic SKOR current,
the macroscopic gating parameters and the single channel conductance remained
unchanged. An external acidification from 7.4 to 6.4 had similar effects. It is
proposed that pH changes regulate the number of channels available for
activation. Sensitivity of SKOR activity to pH in the physiological range
suggests that internal and external pH play a role in the regulation of K+
secretion into the xylem sap.
PMID- 10682859
TI - The platelet cytoskeleton regulates the aggregation-dependent synthesis of
phosphatidylinositol 3,4-bisphosphate induced by thrombin.
AB - Pretreatment of intact platelets with cytochalasin D prevented actin
polymerization and cytoskeleton reorganization induced by thrombin, but did not
affect platelet aggregation. Under these conditions, synthesis of
phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2) stimulated by thrombin was
strongly inhibited, while production of phosphatidic acid was unaffected. The
inhibitory effect of cytochalasin D was not observed when platelet aggregation
was prevented by the RGDS peptide. We also found that cytochalasin D did not
affect PtdIns(3,4)P2 synthesis induced by concanavalin A (ConA), which is known
to occur through an aggregation-independent mechanism. Moreover, thrombin, but
not ConA, induced the translocation of phosphatidylinositol 3-kinase to the
cytoskeleton. This process was equally inhibited by both the RGDS peptide and
cytochalasin D. These results demonstrate that the cytoskeleton represents a
functional link between thrombin-induced aggregation and synthesis of
PtdIns(3,4)P2.
PMID- 10682860
TI - Eukaryotic selenocysteine tRNA has the 9/4 secondary structure.
AB - There are two secondary structure models for the eukaryotic selenocysteine (Sec)
tRNA(Sec). One model, the 9/4 structure, was experimentally tested and possesses
acceptor and T-stems with 9 and 4 bp, respectively [Sturchler et al., 1993;
Hubert et al., 1998]. The other one, the 7/5 secondary structure with a bulge in
the T-stem, was derived from theoretical calculation [Ioudovitch and Steinberg,
19991. In this report, we show more experimental results supporting the 9/4
secondary structure. Several tRNA(Sec) mutants, whose secondary structure can
adopt only the 9/4 structure, were active for serylation and selenylation. Some
mutants that cannot base-pair between positions 26 and 44 to provide the 6 bp
anticodon stem were still active, inconsistent with the model by Steinberg. We
also show that the orientation of the V-arm directly or indirectly influences the
selenylation activity, and that the rigid 6 bp D-stem is important. Finally, we
conclude that all tRNA(Sec) possess the 13 bp domain II made by the stacking of
the colinear AA and T-stems, whether they present the 9/4 structure in Eukarya
and Archaea or the 8/5 structure in bacteria.
PMID- 10682861
TI - Involvement of asparagine 118 in the nucleotide specificity of the catalytic
subunit of protein kinase CK2.
AB - Protein kinase CK2 is a heteromeric enzyme with catalytic (alpha) and regulatory
(beta) subunits which form an alpha2beta2 holoenzyme and utilizes both ATP and
GTP as nucleotide substrate. Site-directed mutagenesis of CK2alpha subunit was
used to study this capacity to use GTP. Deletion of asparagine 118
(alpha(deltaN118)) or the mutant alphaN118E gives a 5-6-fold increase in apparent
Km for GTP with little effect on the affinity for ATP. Mutants alphaN118A and
alphaD120N did not alter significantly the Km for either nucleotide. CK2alphaN118
has an apparent Ki for inosine 5' triphosphate 5-fold higher than wild-type and
is very heat labile. These studies complement recent crystallographic data
indicating a role for CK2alpha asparagine 118 in binding the guanine base.
PMID- 10682862
TI - Identification of a melanoma antigen, PRAME, as a BCR/ABL-inducible gene.
AB - In order to elucidate molecular events in BCR/ABL-induced transformation, we
adopted a polymerase chain reaction (PCR)-based technique of differential display
and compared mRNA expression in human factor-dependent cells, TF-1, with that in
factor-independent cells, ID-1, which were established from TF-1 cells by
transfection of BCR/ABL. Cloning and sequencing of a gene which was upregulated
in ID-1 cells revealed that the gene was identical to a melanoma antigen, PRAME.
Our present study demonstrated that PRAME was markedly expressed in primary
leukemic cells with chronic myeloid leukemia (CML) in blastic crisis and
Philadelphia (Ph)+-acute lymphoblastic leukemia (ALL), in which BCR/ABL played an
important role as a pathogenic gene. Moreover, comparison of PRAME expression
among CD34+ cells with CML in blastic, accelerated, and chronic phases revealed a
higher expression in CML in advanced phases. Thus PRAME was considered to be a
good candidate for a marker of Ph+-leukemic blast cells as well as a new target
antigen of leukemic blast cells that cytotoxic T cells can recognize.
PMID- 10682863
TI - Mutagenesis of the proposed iron-sulfur cluster binding ligands in Escherichia
coli biotin synthase.
AB - Biotin synthase (BioB) is a member of a family of enzymes that includes anaerobic
ribonucleotide reductase and pyruvate formate lyase activating enzyme. These
enzymes all use S-adenosylmethionine during turnover and contain three highly
conserved cysteine residues that may act as ligands to an iron-sulfur cluster
required for activity. Three mutant enzymes of BioB have been made, each with one
cysteine residue (C53, 57, 60) mutated to alanine. All three mutant enzymes were
inactive, but they still exhibited the characteristic UV-visible spectrum of a
[2Fe-2S]2+ cluster similar to that of the wild-type enzyme.
PMID- 10682864
TI - Regulation of the cardiac voltage-gated Na+ channel (H1) by the ubiquitin-protein
ligase Nedd4.
AB - The cardiac voltage-gated Na+ channel H1, involved in the generation of cardiac
action potential, contains a C-terminal PY motif (xPPxY). Since PY motifs are
known ligands to WW domains, we investigated their role for H1 regulation and the
possible involvement of the WW domain containing ubiquitin-protein ligase Nedd4,
taking advantage of the Xenopus oocyte system. Mutation of the PY motif leads to
higher peak currents when compared to wild-type channel. Moreover, co-expression
of Nedd4 reduced the peak currents, whereas an enzymatically inactive Nedd4
mutant increased them, likely by competing with endogenous Nedd4. The effect of
Nedd4 was not observed in the PY motif mutated channel or in the skeletal muscle
voltage-gated Na+ channel, which lacks a PY motif. We conclude that H1 may be
regulated by Nedd4 depending on WW-PY interaction, and on an active
ubiquitination site.
PMID- 10682865
TI - Suppression of GD1alpha ganglioside-mediated tumor metastasis by liposomalized
WHW-peptide.
AB - GD1alpha ganglioside-replica peptides were recently isolated from a phage
displayed random pentadecapeptide library by assaying for inhibition of adhesion
of RAW117-H10 lymphosarcoma cells to hepatic sinusoidal microvessel endothelial
(HSE) cells. We show here that the Trp-His-Trp (WHW) peptide was identified as a
minimal sequence of the GD1alpha-replica peptide WHWRHRIPLQLAAGR. The addition of
WHW peptide-attached liposomes displayed efficient inhibition of liver metastasis
of RAW117-H10 cells as well as of GD1alpha-mediated adhesion of RAW117-H10 cells
to HSE cells in vitro. These results suggest that engineered liposomes for
peptide delivery are applicable to treatment for metastasis.
PMID- 10682866
TI - The N-terminal domain of the light-harvesting chlorophyll a/b-binding protein
complex (LHCII) is essential for its acclimative proteolysis.
AB - Variations in the amount of the light-harvesting chlorophyll a/b-binding protein
complex (LHCII) is essential for regulation of the uptake of light into
photosystem II. An endogenous proteolytic system was found to be involved in the
degradation of LHCII in response to elevated light intensities and the
proteolysis was shown to be under tight regulation [Yang, D.-H. et al. (1998)
Plant Physiol. 118, 827-834]. In this study, the substrate specificity and
recognition site towards the protease were examined using reconstituted wild-type
and mutant recombinant LHCII. The results show that the LHCII apoprotein and the
monomeric form of the holoprotein are targeted for proteolysis while the trimeric
form is not. The N-terminal domain of LHCII was found to be essential for
recognition by the regulatory protease and the involvement of the N-end rule
pathway is discussed.
PMID- 10682867
TI - Subcellular localization and processing of the lytic transglycosylase of the
conjugative plasmid R1.
AB - Protein P19 encoded by the conjugative resistance plasmid R1, is essential for
efficient conjugative DNA transfer and infection by the pilus-specific RNA phage
R17. Based on sequence homologies P19 belongs to a family of lysozyme-like
virulence factors which are found in type III and type IV secretion systems. In
this report we describe the processing and subcellular localization of P19. Pulse
chase experiments were used to demonstrate the processing of P19 by the signal
peptidase I of Escherichia coli. Translocation of P19 across the inner membrane
was shown by gene 19-phoA fusions. Cell fractionation studies of P19 expressing
cells showed the presence of P19 in the membrane compartment. P19 was solubilized
with the detergent Sarkosyl indicating an inner membrane localization. Using
sucrose density gradient centrifugation to separate inner and outer membranes,
P19 was found in both membrane fractions. Taken together, our data suggest that
mature P19 is a periplasmic protein which may be attached to the proposed
membrane-spanning DNA transport complex.
PMID- 10682868
TI - Nutrition on the net.
PMID- 10682869
TI - The potential for dietary supplements to reduce premenstrual syndrome (PMS)
symptoms.
AB - Many types of dietary supplements have been advocated for the reduction of
certain symptoms of premenstrual syndrome (PMS). However, only one supplement
calcium-has been demonstrated to be of significant benefit in a large, rigorous,
double-blind, placebo-controlled trial. Limited evidence suggests that magnesium,
vitamin E and carbohydrate supplements might also be useful, but additional
research is needed to confirm these findings. Trials of vitamin B6
supplementation have had conflicting results, and high doses of this vitamin
taken for prolonged periods of time can cause neurological symptoms. Trials of
evening primrose oil have also had conflicting results; the two most rigorous
studies showed no evidence of benefit. A variety of herbal products are suggested
to reduce symptoms of PMS. The efficacy of these products is uncertain because of
a lack of consistent data from scientific studies. Health professionals should be
aware of the possible use of these supplements and ask those with PMS about their
use of such products and counsel them based upon the totality of evidence.
PMID- 10682870
TI - Preliminary observation: oral zinc sulfate replacement is effective in treating
muscle cramps in cirrhotic patients.
AB - BACKGROUND: While not life threatening, muscle cramps severely affect the quality
of life of patients with cirrhosis. AIM: To determine whether oral zinc sulfate
therapy decreases the frequency and severity of muscle cramps in cirrhotic
patients. METHODS: 12 patients with cirrhosis (5 Child's A, 3 Child's B, and 4
Child's C), hypozincemia and muscle cramps at least thrice weekly received oral
zinc sulfate 220 mg BID for 12 weeks. Patients answered a questionnaire regarding
their muscle cramps symptoms at the beginning and end of the study. RESULTS:
Muscle cramps occurred in all patients at rest, mainly while sleeping (8/12), and
in two patients also during exercise. Cramps were located in calves (10/12), feet
(4/12) and hands (4/12) more commonly. Zinc supplementation improved cramps in
10/12 patients, and in seven of these patients the cramps completely resolved.
One patient experienced mild watery diarrhea that resolved upon discontinuation
of the zinc sulfate. No other complication of zinc supplementation was noted.
CONCLUSION: A potential relationship between zinc deficiency and muscle cramps in
the setting of cirrhosis has not been suggested before. Zinc supplementation may
lead to improvement in symptoms associated with muscle cramps in cirrhosis.
PMID- 10682871
TI - Influence of purine intake on uric acid excretion in infants fed soy infant
formulas.
AB - OBJECTIVE: These studies tested the hypothesis that increasing intake of purines,
delivered as RNA from soy protein-based infant formula, would increase urinary
uric acid excretion in infants. METHODS: Study One examined the influence of
feeding on serum uric acid in a total of 178 infants from four separate trials
with infants fed commercial and experimental soy-based and milk-based infant
formulas or human milk. Studies Two and Three compared the effect of a standard
purine soy formula (STD Purine; 180 mg purines/L from RNA) and a reduced purine
soy formula (Reduced Purine; 65 mg purines/L; 26 mg/L from RNA and 39 mg/L from
ribonucleotides) on urinary uric acid excretion in infants. In Study Two, 11
infants ranging in age from 16 to 128 days of age were fed both formulas in a
random crossover design. Complete 72-hour urine collections were done at the end
of each 11-day feeding period. Urinary uric acid excretion was expressed as
mmol/day. In Study Three, 33 infants were enrolled before eight days of age and
randomized to one of the formulas one week later. Spot urine samples were
collected at 28 and/or 56 days of age and urinary uric acid concentration was
expressed as mmol/mmol creatinine. RESULTS: In Study One, each of the feedings
resulted in mean serum uric acid levels within normal reference ranges. Soy
formula led to higher serum uric acid levels than human milk, and human milk to
levels indistinguishable from cow milk-based formulas. In Study Two, infants
excreted significantly more uric acid in the urine when fed the STD Purine
formula compared to the Reduced Purine formula (0.86+/-.04 vs. 0.57+/-.04 mmol/d)
(p = 0.006). In Study Three, infants fed the STD Purine formula had a
significantly higher concentration of uric acid in their urine compared to those
fed the Reduced Purine formula (2.1+/-0.2 vs. 1.4+/-0.1 mmol uric acid/mmol
creatinine) (p = 0.0001). CONCLUSION: These data indicate that healthy infants
can digest RNA and subsequently absorb the liberated purine ribonucleotides as
determined by urinary uric acid concentration.
PMID- 10682872
TI - Low-density lipoprotein subclass distribution pattern and adiposity-associated
dyslipidemia in postmenopausal women.
AB - OBJECTIVE: A predominance of small, dense low-density lipoprotein (LDL) particles
(subclass pattern B) is associated with increased risk for coronary heart disease
and is characterized by elevated triglycerides and depressed high-density
lipoprotein (HDL) cholesterol concentrations. The present analysis was undertaken
to assess the impact of LDL subclass distribution pattern and adiposity on serum
lipids in postmenopausal women. METHODS: Anthropometric measurements and fasting
lipid data were obtained from 254 postmenopausal women 70 years of age or
younger, not receiving sex hormone replacement, who were participating in a
clinical trial designed to assess the influence of hormone replacement regimens
on coronary heart disease risk markers. RESULTS: The prevalence of LDL subclass
pattern B was 32%. Triglyceride levels were higher and HDL cholesterol lower
(both p<0.001) in women with pattern B vs. pattern A, but total and LDL
cholesterol levels did not differ. LDL subclass pattern contributed independently
to the variance in HDL cholesterol (p<0.001) and log(e) triglyceride (p<0.001)
concentrations explained by anthropometric variables (waist circumference or body
mass index). Compared to women with LDL subclass pattern A and waist
circumference below the median value of 83.0 centimeters, those with pattern B
and waist > or =83.0 centimeters had markedly lower HDL cholesterol levels [44.0
(41.6-47.4) vs. 57.2 (54.1-60.3) mg/dL, mean (95% CI)] and increased triglyceride
concentrations [geometric mean 147.8 (131.6-165.7) vs. 95.4 (88.2-102.5) mg/dL].
CONCLUSIONS: These data suggest that adiposity and LDL subclass distribution
pattern are independent determinants of plasma triglyceride and HDL cholesterol
concentrations in postmenopausal women.
PMID- 10682873
TI - The interaction between dietary fructose and magnesium adversely affects
macromineral homeostasis in men.
AB - OBJECTIVE: Studies with rats have found that an interaction between fructose and
magnesium affects macromineral metabolism; high dietary fructose significantly
increased kidney calcification in both male and female rats, particularly when
dietary magnesium was low. This study tests the hypothesis that an interaction
between dietary fructose and magnesium adversely affects macromineral homeostasis
in men. METHODS: Eleven men aged 22 to 40 years were fed a mixed, Western diet
for four 42-day dietary periods in which dietary magnesium was either
approximately 170 or 370 mg/day and dietary fructose was either 4% or 20% of
energy. A decaffeinated beverage containing high fructose corn syrup replaced
cornstarch, bread and rice in the low fructose diet to give the high fructose
diet. RESULTS: High dietary fructose significantly (p<0.01) increased magnesium
balance during both low and high dietary magnesium intakes. Ultrafilterable and
ionized serum magnesium also apparently were related to magnesium and fructose
intakes; they were higher when fructose was fed and when Mg intakes were high.
High fructose depressed calcium balance: the effect tended to be more marked when
dietary Mg was low. High dietary fructose also significantly (p<0.005) decreased
phosphorous balance. Urinary phosphorous losses were significantly (p<0.001)
higher when high dietary fructose was fed. High dietary fructose also increased
the concentration of serum alkaline phosphatase (p<0.005). CONCLUSION: These
findings indicate that dietary fructose adversely affects macromineral
homeostasis in humans and suggest further studies to see if a high fructose diet
coupled with low dietary magnesium and marginal calcium leads to bone loss.
PMID- 10682874
TI - A noninvasive measure of physical maturity as a predictor of bone mass in
children.
AB - OBJECTIVE: The purpose of this study was to describe the accumulation of whole
body bone mass in a longitudinal study of prepubertal boys and girls using
Roche's physical maturity index as a measure of developmental age. METHODS: We
measured 561 children (39% white, 61% African-American) from a suburban school
district, representing an ethnically mixed, middle-class community adjacent to
Detroit. Anthropometric measures taken for the present study included recumbent
length (cm), stature (cm), weight (kg), whole body bone mineral content (WBBMC in
g) and a noninvasive measure of physical maturity (PM%). PM% was calculated from
published formulae derived from data from the Fels Longitudinal Study, using
recumbent length, weight, midparental stature, age, and age- and gender-specific
regression coefficients. RESULTS: At average age 9.9 (+/-0.6) years, there were
no significant gender differences in stature, recumbent length, weight, or WBBMC
in either ethnic group. Average PM for girls was significantly greater than that
for boys within each ethnic group. There were no significant ethnic differences
in PM in either gender. Stature and WBBMC were significantly different in the two
ethnic groups for both boys and girls. Regressions of WBBMC on PM and
chronological age indicated that PM explained more of the variance in WBBMC than
did age (r2 ranging from 0.28 to 0.75 for PM versus 0.01 to 0.06 for age). In the
case of African-American boys, r2 was similar (0.09 for PM and 0.06 for age).
CONCLUSIONS: PM is a useful, noninvasive measure of developmental age that is
significantly correlated with bone mass in children. Our study also indicates
that PM is a better predictor of WBBMC than chronological age. Because PM can be
calculated without using invasive and potentially expensive methods, PM may be
useful in some clinical as well as research settings.
PMID- 10682875
TI - The effects of varying dietary fat on the nutrient intake in male and female
runners.
AB - OBJECTIVE: The present study examined the effects of varying dietary fat levels
on nutrients in female and male endurance runners. METHODS: Three diets (low,
medium and high fat) were designed for each subject using their food preferences
and three-day food records. Each diet was eaten for 28 to 31 days. The diets were
self-selected from seven-day sample menus. Twelve male and 13 female runners
between 18 and 55 years of age who averaged 42 miles/week participated in the
study. Daily food intakes, activity records and weekly palatability/hunger scales
were completed. RESULTS: Dietary fat intakes, as a percent of total energy intake
(%E), averaged 17%E, 31%E, and 44%E on the low, medium and high fat diets,
respectively. Energy consumption was less than their estimated energy expenditure
(EEE) on all diets. On the low fat diet, the female runners were consuming
approximately 60% of their EEE. As dietary fat increased, the difference between
calorie intake and estimated energy expenditure became less and the subjects were
less hungry on the two higher fat diets. For all subjects, as energy intakes
increased, so did carbohydrate intake. Therefore, carbohydrate intake was not
different on the two lower fat diets. Irrespective of gender, calcium and zinc
intakes, which were below 1989 RDAs, increased with increasing fat intakes,
between the low and medium fat diets. Zinc intake was also higher on the highest
fat diet. Essential fatty acid intakes for females on the low fat diet were less
than 2.5%E. Half of the female runners ate less than the RDA of calcium and zinc
on the low fat diet and Fe on the medium fat diet. CONCLUSION: This study
suggests that endurance runners may not be consuming enough calories on a low fat
diet and that increasing dietary fat increased energy consumption. On the low fat
diet, essential fatty acids and some minerals (especially zinc) may be too low. A
low fat diet could compromise health and performance.
PMID- 10682876
TI - The effects of varying dietary fat on performance and metabolism in trained male
and female runners.
AB - OBJECTIVES: Low dietary fat intake has become the diet of choice for many
athletes. Recent studies in animals and humans suggest that a high fat diet may
increase VO2max and endurance. We studied the effects of a low, medium and high
fat diet on performance and metabolism in runners. METHODS: Twelve male and 13
female runners (42 miles/week) ate diets of 16% and 31% fat for four weeks. Six
males and six females increased their fat intakes to 44%. All diets were designed
to be isocaloric. Endurance and VO2max were tested at the end of each diet.
Plasma levels of lactate, pyruvate, glucose, glycerol, and triglycerides were
measured before and after the VO2max and endurance runs. Free fatty acids were
measured during the VO2max and endurance runs. RESULTS: Runners on the low fat
diet ate 19% fewer calories than on the medium or high fat diets. Body weight,
percent body fat (males=71 kg and 16%; females=57 kg and 19%), VO2max and
anaerobic power were not affected by the level of dietary fat. Endurance time
increased from the low fat to medium fat diet by 14%. No differences were seen in
plasma lactate, glucose, glycerol, triglycerides and fatty acids when comparing
the low versus the medium fat diet. Subjects who increased dietary fat to 44% had
higher plasma pyruvate (46%) and lower lactate levels (39%) after the endurance
run. CONCLUSION: These results suggest that runners on a low fat diet consume
fewer calories and have reduced endurance performance than on a medium or high
fat diet. A high fat diet, providing sufficient total calories, does not
compromise anaerobic power.
PMID- 10682877
TI - A diet high in whole and unrefined foods favorably alters lipids, antioxidant
defenses, and colon function.
AB - OBJECTIVE: Diets rich in whole and unrefined foods, like whole grains, dark green
and yellow/orange-fleshed vegetables and fruits, legumes, nuts and seeds, contain
high concentrations of antioxidant phenolics, fibers and numerous other
phytochemicals that may be protective against chronic diseases. This study
compared the effects of a phytochemical-rich diet versus a refined-food diet on
lipoproteins, antioxidant defenses and colon function. METHODS: Twelve
hyperlipidemic women followed two diets for four weeks starting with a refined
food diet. Subjects then directly crossed over to the phytochemical-rich diet.
Duplicate, fasting serum lipids and single, fasting antioxidant enzymes were
measured at the end of the four-week refined-food diet period (baseline) and
again at the end of the phytochemical-rich diet period. RESULTS: Total energy and
total fat intake were similar during both diet periods, but there was a decrease
in saturated fat (SFA) of 61% in the phytochemical-rich diet group. Dietary
fiber, vitamin E, vitamin C and carotene intakes were 160%, 145%, 160% and 500%
more, respectively, than during the refined-food diet period. The phytochemical
rich diet induced a drop of 13% in total cholesterol (TC) (p < 0.05) and 16% (p <
0.001) in low density lipoprotein-cholesterol (LDL-C). Erythrocyte superoxide
dismutase decreased 69% (p < 0.01) and glutathione peroxidase dropped 35% (p <
0.01). Colon function was improved on the phytochemical-rich diet. CONCLUSIONS: A
diet abundant in phytochemically-rich foods beneficially affected lipoproteins,
decreased need for oxidative defense mechanisms and improved colon function.
PMID- 10682878
TI - Serum vitamin B12, C and folate concentrations in the New Mexico elder health
survey: correlations with cognitive and affective functions.
AB - OBJECTIVES: 1) To compare serum vitamin B12, C and folate concentrations in a
randomly selected sample of elderly (age 65 years or older) male and female
Hispanics and nonHispanic whites (NHW) and 2) to examine associations between
serum B12, C and folate concentrations compared to measures of cognitive and
affective (depression) functions. METHODS: Equal numbers of male and female
Hispanics and NHW were randomly sampled from the Health Care Financing
Administration (Medicare) registrant list for Bernalillo County, New Mexico, and
asked to volunteer for a paid home interview followed by a paid comprehensive
interview/examination covering health and health-related issues. In addition to
serum determinations of B12, C and folate, associations were examined between
these vitamins and measures of cognitive and affective functions. RESULTS: Males
and Hispanics had lower serum vitamin B12, C and folate concentrations than
females and NHW respectively. Participants taking a multivitamin supplement (MVI)
had higher serum vitamin concentrations than those not taking MVI. There were
significant associations between serum folate concentrations and measures of
cognitive function, not seen with B12 or C, nor between any of the vitamins and
affective function. CONCLUSIONS: Hispanics, even after adjustments for gender,
age, vitamin supplementation, vitamin content of dietary foods, education and
household income, had lower serum concentrations of B12, C and folate than NHW.
The most significant associations observed were those between serum folate and
various measures of cognitive function, even after adjusting for presence of
depression.
PMID- 10682879
TI - Predictors of screening for breast, cervical, colorectal, and prostatic cancer
among community-based primary care practices.
AB - BACKGROUND: As we enter the year 2000, it is worth looking at whether primary
care practices are reaching the goals established in Healthy People 2000 for
breast, cervical, colorectal, and prostatic cancer screening. The objectives of
this study were (1) to determine the current rates of cancer screening; and (2)
to determine which factors predict completion of a single screening test, of all
tests for each cancer, and of all procedures for age and sex. METHODS: Medical
records of 200 eligible patients (100 men and 100 women) from each of 24
community-based primary care practices were abstracted for cancer-screening
events. RESULTS: We audited 5125 charts. A Papanicolaou smear was documented for
63.8% of women with an intact cervix within 3 years of the audit.. We found that
46.8% of women had documentation of ever having a discussion of breast self
examination. For breast cancer screening, 41.8% of the women had a clinical
breast examination within 1 year, 48.2% aged 40 to 49 years had a mammogram
within 2 years, and 38.5% aged 50 years and older had a mammogram within 1 year.
Only 29% of women aged 40 to 49 years and 17% of women 50 years and older were
current for all breast cancer-screening tests. Among patients 50 years and older,
33% of men and 38% of women had a digital rectal examination within 1 year, 26%
of men and 28% of women had a fecal occult blood test within 1 year, and 22% of
men and 16.8% of women had a flexible sigmoidoscopy within 5 years. Of all men
28.7% had a prostate-specific antigen test within 1 year. Completion of all tests
relevant for age and sex were documented for 8.6% of women aged 40 to 49 years,
3% of women 50 years and older, and 5% of men 50 years and older. The single most
significant predictor of documented cancer screening was a health maintenance
visit. CONCLUSIONS: This sample of primary care clinicians has not reached the
goals set in Healthy People 2000 for cancer screening. Interventions aimed at
increasing the percentage of patients who schedule a health maintenance visit
could serve to increase cancer screening and help us reach goals set for the year
2010.
PMID- 10682881
TI - Elderly deaf patients' health care experiences.
AB - BACKGROUND: Approximately 10% of the US population has some degree of hearing
loss, and 2 million Americans are deaf. Most medical school curricula and major
textbooks characterize deafness as pathologic condition only, which is at odds
with the movement to understand the Deaf population as a minority group with a
unique language and cultural tradition. Physicians might therefore be unprepared
to meet the needs of deaf patients effectively and sensitively. This study seeks
to understand the health care experiences of elderly Deaf adults in Richmond, Va.
METHODS: The authors conducted focus groups of elderly Deaf persons. Real-time
voice-interpretation of the sign language communication allowed for tape
recording and full transcription. The authors independently analyzed the
transcripts using an editing style, and incorporated feedback on their
interpretation from participants. RESULTS: Participants experienced many
practical barriers to effective health care, including problems with scheduling
appointments and communicating with providers. They believed that providers are
ill-prepared to care for them and worried that prejudice might be a more subtle
obstacle. Participants seemed resigned to these circumstances. CONCLUSIONS: The
authors suggest a possible explanation for this perspective, and make specific
recommendations for three levels of competency in caring for deaf patients. When
the provider and the office staff provide methods to communicate with deaf
patients using telephone-assisted communication, qualified interpreters, and some
basic knowledge of lipreading or sign language, the care of deaf patients is
greatly enhanced and the physician-patient relationship improved.
PMID- 10682882
TI - Care of the elderly patient with lower extremity amputation.
AB - BACKGROUND: The elderly patient with a lower extremity amputation (LEA) remains
relatively common in most family medicine practices. LEA can be categorized into
three major types: partial foot, transtibial amputation, and transfemoral
amputation. Family physicians have not been well trained to provide care to these
patients. METHODS: A literature review was performed using the key words "lower
extremity amputation," "aged" and "rehabilitation." RESULTS AND CONCLUSIONS:
Appropriate medical, surgical, and rehabilitative care can have a positive effect
on the functional outcome for an elderly patient with a lower extremity
amputation. The family physician can be instrumental in preparing the patient and
family for surgery, providing psychological support, preventing and treating
complications, managing comorbid illness, and assisting in rehabilitation. In
addition, the family physician is primarily responsible for the daily care needs
of these patients.
PMID- 10682880
TI - Adolescent preventive health visits: a comparison of two invitation protocols.
AB - BACKGROUND: Adolescent health care in family practice at times creates
conflicting responsibilities for parents and their teenagers. In the context of a
new adolescent preventive health program in a family practice setting, we
compared attendance rates using two invitation protocols, the protocols differing
in their emphasis on adolescent autonomy vs parental responsibility. METHODS: One
hundred six teenagers in the seventh and tenth grades were invited for preventive
health visits with the family nurse and physician using two protocols. Protocol 1
involved obtaining parental consent before approaching the adolescent. With
protocol 2, an invitation letter and parental consent form were mailed to the
teenager, while a letter of explanation was sent concurrently to the parents. In
each case, the letter of invitation was followed up by a telephone call for those
who did not respond. The spontaneous response rate (a positive response after
receiving the letter), agreement to attend rate (a positive response after
receiving the letter or being telephoned), and the attendance rate were
determined according to grade, sex, and protocol. RESULTS: The spontaneous
response rate was 21%, the agreement to attend rate was 75%, and the attendance
rate was 44%. Attendance rates were higher for the girls compared with the boys
(54% vs 35%, P = .08) and for the seventh graders compared with the tenth graders
(53% vs 31%, P = .03). The spontaneous response rate was lower among the tenth
graders using protocol 2 (8% vs 37.5% with protocol 1, P = .04), while the
agreement to attend rate and attendance rate did not differ for the two
protocols. CONCLUSIONS: Nearly one half of this population of adolescents
attended preventive health visits at the family nurse's and physician's
initiative. A follow-up telephone call after the initial written invitation
resulted in increased participation, while approaching the teenager or parent
initially did not make a difference in attendance. This pilot study shows the
potential for initiating an adolescent health program in the family practice
setting.
PMID- 10682883
TI - Transient hyperthyroidism of hyperemesis gravidarum: a sheep in wolf's clothing.
AB - BACKGROUND: Transient hyperthyroidism of hyperemesis gravidarum (THHG) is a self
limiting hyperthyroidism occurring in the context of hyperemesis gravidarum.
METHODS: A literature search of MEDLINE was undertaken, and a case report of a
woman with THHG in pregnancy is described. RESULTS AND CONCLUSIONS: Because
thyroid function tests cannot distinguish Graves disease from THHG, the diagnosis
of THHG rests largely on the concurrent development of hyperemesis and
hyperthyroidism and the absence of signs and symptoms of hyperthyroidism before
and during pregnancy. THHG might be responsible for 40% to 70% of thyroid
function abnormalities in pregnancy. Both the thyroid function abnormalities and
hyperemesis are related to elevated levels of human chorionic gonadotropin. THHG
resolves by 18 weeks of pregnancy without sequelae. No treatment is required.
Diagnosis of THHG by the primary care provider can prevent unnecessary treatment
or referral for specialty care.
PMID- 10682884
TI - Late postpartum eclampsia 16 days after delivery: case report with clinical,
radiologic, and pathophysiologic correlations.
AB - BACKGROUND: Postpartum eclampsia is a rare, frightening, and potentially tragic
complication of hypertensive pregnancies, usually developing within 48 hours of
delivery. Seizures occurring days to weeks after parturition are exceedingly
uncommon and require rapid, precise clinical evaluation by multiple specialists.
METHODS: A case presentation of delayed postpartum eclampsia illustrates unique
features of the syndrome. Extensive review of the literature highlights
pathogenesis, controversies, and dilemmas surrounding this enigmatic hypertensive
disorder. RESULTS AND CONCLUSIONS: A 39-year-old hypertensive patient had an
uneventful full-term delivery by her family physician only to develop headache,
double vision, and recurrent tonic-clonic seizures 16 days later. Initial
evaluation showed severe hypertension, diplopia, hyperreflexia, proteinuria, and
hyperuricemia. She was given a magnesium sulfate infusion. Magnetic resonance
imaging (MRI) documented asymmetric ischemic foci within gray matter in the
distribution of the posterior cerebral arteries. All symptoms, signs, and
abnormal laboratory values resolved within 4 days. A follow-up MRI showed
complete resolution of all cytotoxic cortical lesions. Based on human autopsy
data, radiologic investigations, and animal studies, eclampsia is believed to
result from explosive vasospasm, endothelial dysfunction, and cytotoxic edema of
cerebral cortex. This central nervous system vasculopathy is most prominent in
the posterior cerebral vasculature and is often rapidly reversible. Difficulties
in differential diagnosis, typical findings on neuroimaging, and urgent
management strategies are discussed. The time limit for postpartum eclampsia
probably should be lengthened to 4 weeks, as indicated by our case and other
clinical series.
PMID- 10682885
TI - Cost-effectiveness of primary care.
AB - This article is intended only as an introduction to the use of cost-effectiveness
analysis in primary care. The goals are to provide a clear understanding of the
difference between the cost of a treatment and its cost-effectiveness; consider
what is generally a socially acceptable range for cost-effectiveness; provide
some basic criteria for critically evaluating cost-effectiveness analyses in the
medical literature; give some examples of the cost-effectiveness of various
treatments in primary care; and provide for comparison some examples of cost
effectiveness in the world of specialty care. For those interested in more
detail, excellent books and reviews are available, including the report of a US.
Public Health Service-appointed expert panel.
PMID- 10682886
TI - Combined ipratropium and beta2--adrenergic receptor agonist in acute asthma.
PMID- 10682887
TI - Rhabdomyolysis in a teenage boy: a case report.
PMID- 10682888
TI - Jaundice and disseminated intravascular coagulopathy in pregnancy.
PMID- 10682889
TI - Toothpaste allergy with intractable perioral rash in a 10-year old boy.
PMID- 10682890
TI - Acute intermittent porphyria with seizure and paralysis in the puerperium.
PMID- 10682891
TI - Health care of the deaf--toward a new understanding.
PMID- 10682892
TI - Implementing clinical preventive medicine: time to fish or cut bait.
PMID- 10682893
TI - Critical appraisal of the literature.
PMID- 10682894
TI - Firearm safety as preventive medicine.
PMID- 10682895
TI - Birth and death through a child's eyes.
PMID- 10682896
TI - Birth and death through a child's eyes.
PMID- 10682897
TI - Birth and death through a child's eyes.
PMID- 10682898
TI - Birth and death through a child's eyes.
PMID- 10682899
TI - Regulation of calcium in salivary gland secretion.
AB - Neurotransmitter-regulation of fluid secretion in the salivary glands is achieved
by a coordinated sequence of intracellular signaling events, including the
activation of membrane receptors, generation of the intracellular second
messenger, inositol 1,4,5, trisphosphate, internal Ca2+ release, and Ca2+ influx.
The resulting increase in cytosolic [Ca2+] ([Ca2+]i) regulates a number of ion
transporters, e.g., Ca2+-activated K+ channel, Na+/K+/2Cl- co-transporter in the
basolateral membrane, and the Ca2+-activated Cl- channel in the luminal membrane,
which are intricately involved in fluid secretion. Thus, regulation of [Ca2+]i is
central to the regulation of salivary acinar cell function and is achieved by the
concerted activities of several ion channels and Ca2+-pumps localized in various
cellular membranes. Ca2+ pumps, present in the endoplasmic reticulum and the
plasma membrane, serve to remove Ca2+ from the cytosol. Ca2+ channels present in
the endoplasmic reticulum and the plasma membrane facilitate rapid influx of Ca2+
into the cytosol from the internal Ca2+ stores and from the external medium,
respectively. It is well-established that prolonged fluid secretion is regulated
via a sustained elevation in [Ca2+]i that is primarily achieved by the influx of
Ca2+ into the cell from the external medium. This Ca2+ influx occurs via a
putative plasma-membrane-store-operated Ca2+ channel which has not yet been
identified in any non-excitable cell type. Understanding the molecular nature of
this Ca2+ influx mechanism is critical to our understanding of Ca2+ signaling in
salivary gland cells. This review focuses on the various active and passive Ca2+
transport mechanisms in salivary gland cells--their localization, regulation, and
role in neurotransmitter-regulation of fluid secretion. In addition to a
historical perspective of Ca2+ signaling, recent findings and challenging
problems facing this field are highlighted.
PMID- 10682900
TI - The impact of molecular genetics on oral health paradigms.
AB - As a result of our increased understanding of the human genome, and the
functional interrelationships of gene products with each other and with the
environment, it is becoming increasingly evident that many human diseases are
influenced by heritable alterations in the structure or function of genes.
Significant advances in research methods and newly emerging partnerships between
private and public sector interests are creating new possibilities for
utilization of genetic information for the diagnosis and treatment of human
diseases. The availability and application of genetic information to the
understanding of normal and abnormal human growth and development are
fundamentally changing the way we approach the study of human diseases. As a
result, the issues and principles of medical genetics are coming to bear across
all disciplines of health care. In this review, we discuss some of the potential
applications of human molecular genetics for the diagnosis and treatment of oral
diseases. This discussion is presented in the context of the ongoing
technological advances and conceptual changes that are occurring in the field of
medical genetics. To realize the promise of this new molecular genetics, we must
be prepared to foresee the possibilities and to incorporate these newly emergent
technologies into the evolving discipline of dentistry. By using examples of
human conditions, we illustrate the broad application of this emerging technology
to the study of simple as well as complex genetic diseases. Throughout this
paper, we will use the following terminology: Penetrance--In a population,
defined as the proportion of individuals possessing a disease-causing genotype
who express the disease phenotype. When this proportion is less than 100%, the
disease is said to have reduced or incomplete penetrance. Polymerase chain
reaction (PCR)--A technique for amplifying a large number of copies of a specific
DNA sequence flanked by two oligonucleotide primers. The DNA is alternately
heated and cooled in the presence of DNA polymerase and free nucleotides, so that
the specified DNA segment is denatured, hybridized with primers, and extended by
DNA polymerase. MIM--Mendelian Inheritance in Man catalogue number from V.
McKusick's Mendelian Inheritance in man (OMIM, 1998).
PMID- 10682901
TI - Acute and chronic craniofacial pain: brainstem mechanisms of nociceptive
transmission and neuroplasticity, and their clinical correlates.
AB - This paper reviews the recent advances in knowledge of brainstem mechanisms
related to craniofacial pain. It also draws attention to their clinical
implications, and concludes with a brief overview and suggestions for future
research directions. It first describes the general organizational features of
the trigeminal brainstem sensory nuclear complex (VBSNC), including its input and
output properties and intrinsic characteristics that are commensurate with its
strategic role as the major brainstem relay of many types of somatosensory
information derived from the face and mouth. The VBSNC plays a crucial role in
craniofacial nociceptive transmission, as evidenced by clinical, behavioral,
morphological, and electrophysiological data that have been especially derived
from studies of the relay of cutaneous nociceptive afferent inputs through the
subnucleus caudalis of the VBSNC. The recent literature, however, indicates that
some fundamental differences exist in the processing of cutaneous vs. other
craniofacial nociceptive inputs to the VBSNC, and that rostral components of the
VBSNC may also play important roles in some of these processes. Modulatory
mechanisms are also highlighted, including the neurochemical substrate by which
nociceptive transmission in the VBSNC can be modulated. In addition, the long
term consequences of peripheral injury and inflammation and, in particular, the
neuroplastic changes that can be induced in the VBSNC are emphasized in view of
the likely role that central sensitization, as well as peripheral sensitization,
can play in acute and chronic pain. The recent findings also provide new insights
into craniofacial pain behavior and are particularly relevant to many approaches
currently in use for the management of pain and to the development of new
diagnostic and therapeutic procedures aimed at manipulating peripheral inputs and
central processes underlying nociceptive transmission and its control within the
VBSNC.
PMID- 10682902
TI - Biomarkers and molecular epidemiology and chemoprevention of oral carcinogenesis.
AB - Chemopreventives are chemicals that prevent the formation of cancers such as oral
cancer. They can take the form of nutrients or synthetic molecules, and their
fundamental characteristic is that they do not produce disease processes that
would result in debilitating symptoms. Current evidence indicates that they
function by modifying the oxidative state of transforming cells. Biomarkers can
take the form of genetic and molecular indicators, which characterize the
function of chemopreventives and cancer processes such as oral carcinogenesis.
Biomarkers cannot provide all the required information for risk assessment or
possible activity of the chemopreventives. Other methods, such as epidemiological
analyses and techniques, must be used to enhance our understanding of the risk
for oral cancer in human populations. One common epidemiologic method, the
questionnaire, helps to determine the use and carcinogenic potential of tobacco
and alcohol during oral carcinogenesis. Genetic and molecular changes in human
patient populations may result in a reduction in the number and function of tumor
suppressor genes. If these changes are to be assessed, the tissues (e.g., buccal
mucosa) must be accessible and harvested in a reliable and consistent manner for
the acquisition of DNA, mRNA, and protein. Oral tissues provide sufficient
quantities of these molecules and, under stringent conditions, the quality
required for the isolation of these molecular constituents. In conjunction with
epidemiologic techniques, various genotypic polymorphisms, such as glutathione-S
transferase (GSTM1) or cytochrome P450 (CYP450A1), have indicated a loss in
carcinogen detoxification or the processing of internal growth control signals.
Biomarkers are composed of a large diverse group of genetic and molecular
structures. Some of these biomarkers are indicators for programmed cell death
(PCD), while others describe malignant tumor growth. Many of these classes of
molecules are oxidative-responsive (e.g., tumor suppressor p53, Bcl-2, growth
factors, immune-derived proteins, and death-inducing molecules) and induce PCD by
triggering a cascade of cysteine proteases and regulators (e.g., caspases, death
receptors). This pathway results in cell-cycle alterations and DNA fragmentation.
It is hoped that a detailed knowledge of the processes involved in malignant
transformation will better define the biomarker-screening tools for oral cancer.
These tools will enhance our ability to predict the incidence of cancer, detect
early malignant change, and quantitate chemoprevention during oral
carcinogenesis. Chemopreventives such as the retinoids have already demonstrated
their ability to suppress potential malignant changes in pre-malignant oral
leukoplakias and decrease the incidence of second head-and-neck cancer primaries.
It is our hope that this review will increase investigators' interest in
developing new screening and detection systems for oral cancer.
PMID- 10682903
TI - Biomechanics of the mandible.
AB - In this review the biomechanical behavior of the mandibular bone tissue, and of
the mandibular bone as a whole, in response to external loading is discussed. A
survey is given of the determinants of mandibular stiffness and strength,
including the mechanical properties and distribution of bone tissue and the size
and shape of the mandible. Mandibular deformations, stresses, and strains that
occur during static biting and chewing are reviewed. During biting and the
powerstroke of mastication, a combination of sagittal bending, corpus rotation,
and transverse bending occurs. The result is a complex pattern of stresses and
strains (compressive, tensile, shear, torsional) in the mandible. To be able to
resist forces and bending and torsional moments, not only the material properties
of the mandible but also its geometrical design is of importance. This is
reflected by variables like polar and maximum and minimum moments of inertia and
the relative amount and distribution of bone tissue. In the longitudinal
direction, the mandible is stiffer than in transverse directions, and the
vertical cross-sectional dimension of the mandible is larger than its transverse
dimension. These features enhance the resistance of the mandible to the
relatively large vertical shear forces and bending moments that come into play in
the sagittal plane.
PMID- 10682904
TI - Commentary on the challenges of establishing gene medicines as a new class of
therapeutics.
PMID- 10682905
TI - Non-viral peptide-based approaches to gene delivery.
AB - To achieve effective non-viral gene therapy, the control of in vitro and in vivo
stability, cellular access, intracellular trafficking and nuclear retention of
plasmids must be achieved. Inefficient endosomal release, stability against
cytosolic nucleases, cytoplasmic transport and nuclear entry of plasmids are
amongst some of the key limiting factors in the use of plasmids for effective
gene therapy. Synthetic peptide-based gene delivery systems can be designed for
DNA compaction, serum stability, cell-specific targeting, endosomolysis,
cytoplasmic stability and nuclear transport. The stability of compacted DNA under
physiological conditions can be enhanced by the use of hydrophilic polymers, such
as polyethylene glycol. The aims of this review are to (i) explore theoretical
and experimental aspects of DNA compaction, (ii) describe approaches for
stabilizing compacted DNA, (iii) assess techniques used for characterization of
compacted DNA, and (iv) review possible use of peptides for efficient gene
transfer.
PMID- 10682906
TI - Gene transfer into the CNS using recombinant adeno-associated virus: analysis of
vector DNA forms resulting in sustained expression.
AB - Recombinant adeno-associated virus (rAAV) vectors have shown significant promise
as vehicles for in vivo gene transfer, particularly for transduction of organs
composed primarily of non-dividing cells (i.e., muscle, CNS, and liver). However,
the mechanistic basis for this desirable property remains unclear. To investigate
the fate of rAAV genomes in mouse brain, we stereotactically injected an rAAV
vector carrying the E. coli lacZ gene into the caudate of BALB/c mice and
demonstrate efficient transduction of mouse brain cells that possess cellular
morphology consistent with post-mitotic neurons. We observed a significant
increase in beta-galactosidase expression from 5 to 56 days after injection that
paralleled the disappearance of single-stranded DNA input genomes. Analysis of in
vivo viral DNA forms over time out to 5 months after inoculation revealed that
rAAV genomes associated with high molecular weight mouse chromosomal DNA by 14
days after injection and persisted for the length of this study. The pattern of
Southern hybridization was consistent with random viral integration in
predominantly head-to-tail concatameric arrays. Importantly, we also documented
an additional DNA species that appears to be a monomeric episomal circular form
based on nuclease sensitivity assays. These data are the first to document the
existence of multiple vector DNA forms present within the adult murine brain
following direct rAAV inoculation and therefore, provide insight into the
molecular events that ultimately result in long-term rAAV mediated transgene
expression.
PMID- 10682907
TI - Synthesis and characterization of aromatic ring-based cationic lipids for gene
delivery in vitro and in vivo.
AB - A new series of cationic lipids has been synthesized for gene delivery using 3,5
dihydroxybenzyl alcohol as the backbone and starting material. Using CMV driven
expression system and luciferase gene as a reporter, we demonstrated that the
transfection activity of these new lipids when formulated with Tween 80 as co
lipid is comparable to that of DOTAP, one of the most commonly used cationic
lipids for transfection. Among the four different cell lines tested including
murine melanoma BL-6 cells, human embryonic kidney 293 cells, HepG2 and HeLa
cells, the highest transgene expression was seen in 293 cells. Results from in
vivo experiments using mice as an animal model show that these cationic lipids
preferentially transfect the cells in the lung upon tail vein administration. The
cationic lipid, N,N,N-trimethyl-N-[3,5-bis(tetradecyloxy)benzyl] ammonium bromide
4c(di-C14:0) with two 14-hydrocarbon chains exhibits the best transfection
activity. These results suggest that these new aromatic ring-based cationic
lipids are useful transfection reagents for both in vitro and in vivo gene
transfer studies.
PMID- 10682908
TI - Development of transferrin-polycation/DNA based vectors for gene delivery to
melanoma cells.
AB - We describe the comparison of non-viral polycation transfection reagents,
adenovirus-enhanced transferrinfection (AVET), polyethylenimine (PEI800) and
transferrin-conjugated PEI800 (Tf-PEI800) in their ability to transfect murine
and primary human melanoma cell lines. Expression of a reporter gene, cell
surface marker and secreted protein (interleukin-2) was assessed for each vector
system. Testing for luciferase reporter gene expression in murine and primary
human cell lines, AVET and Tf-PEI800, both showed high levels of expression and
comparable activity. Furthermore, when the melanoma cell line B16F10 was
transfected with a cell surface marker up to approximately 97% of the cells
expressed the protein on the cell surface. Assessing the levels of secreted IL-2
in murine cell lines, AVET/IL-2, Tf-PEI800/IL-2 and PEI800/IL-2 all expressed
high levels of the cytokine (up to 20 microg IL-2/10(6) cells/24 h). In primary
human melanoma cell lines, AVET/IL-2 transfected cells secreted more IL-2 than
cells transfected with either Tf-PEI800/IL-2 or PEI800/IL-2. In murine melanoma
cell culture experiments, positively charged PEI800/DNA and Tf-PEI800/DNA
complexes gave similar transfection efficiencies. However, when subcutaneous
tumors in mice were injected with the luciferase reporter gene complexed with
either Tf-PEI800 or AVET, higher transfection activity was measured in the tumors
as compared to ligand free PEI800/DNA complexes.
PMID- 10682909
TI - Optimisation of polyethylenimine-based gene delivery to mouse brain.
AB - Polyethylenimine (PEI) is proving to be an efficient and versatile vector for
gene delivery in vivo. However, a limiting factor is the relatively short
duration of gene expression in some sites. Given the particularly high levels of
expression seen in the short term we postulated that loss of expression could
result from overloading the nucleus with foreign DNA. To address this problem we
first followed DNA delivery and localisation with digoxin-labelled plasmid DNA
complexed with 22 kD linear PEI and used these complexes for intraventricular
injection into brains of anaesthetised newborn mice. At 24 h post-injection,
labelled DNA was found exclusively in the nuclear and perinuclear regions. We
next carried out a dose response curve using decreasing amounts of DNA, either in
a constant volume (2 microl) or at a constant concentration (500 ng/microl). In
both conditions, transgene expression yield was maximum at 100 ng DNA per
injection. Using this optimal amount of DNA increased yield of transgene
expression significantly at 24 h and one week post-injection as compared to 1
microg DNA. A final point addressed was whether co-expressing an anti-apoptotic
gene could enhance gene expression in the longer term. Co-expressing bcl-X(L)
with luciferase or LacZ significantly increased expression of both these genes at
one week post-injection.
PMID- 10682910
TI - Comparison of process parameters for microencapsulation of plasmid DNA in
poly(D,L-lactic-co-glycolic) acid microspheres.
AB - Poly(D,L-lactic-co-glycolic) acid (PLGA) microspheres containing plasmid DNA
encoding the firefly luciferase gene were prepared using the water-in-oil-in
water (w/o/w) double emulsion and solvent evaporation method. In this study, we
investigated the effects of three process parameters on DNA microencapsulation:
(1) emulsification method used to generate the primary emulsion, (2) water/oil
ratio during formation of the first emulsion, and (3) surfactant concentration
used in the preparation of the second emulsion. The resulting formulations were
also analyzed for microsphere size, encapsulation efficiency, and kinetics of DNA
release. We found that although each process alteration resulted in encapsulation
of biologically active, structurally intact DNA, the surfactant and water/oil
ratio significantly affected the size, release kinetics and encapsulation
efficiency of plasmid DNA.
PMID- 10682911
TI - Inactivation of the reconstituted oxoglutarate carrier from bovine heart
mitochondria by pyridoxal 5'-phosphate.
AB - The effect of pyridoxal 5'-phosphate and some other lysine reagents on the
purified, reconstituted mitochondrial oxoglutarate transport protein has been
investigated. The inhibition of oxoglutarate/oxoglutarate exchange by pyridoxal
5'-phosphate can be reversed by passing the proteoliposomes through a Sephadex
column but the reduction of the Schiff's base by sodium borohydride yielded an
irreversible inactivation of the oxoglutarate carrier protein. Pyridoxal 5'
phosphate, which caused a time- and concentration-dependent inactivation of
oxoglutarate transport with an IC50 of 0.5 mM, competed with the substrate for
binding to the oxoglutarate carrier (Ki = 0.4 mM). Kinetic analysis of
oxoglutarate transport inhibition by pyridoxal 5'-phosphate indicated that
modification of a single amino acid residue/carrier molecule was sufficient for
complete inhibition of oxoglutarate transport. After reduction with sodium
borohydride [3H]pyridoxal 5'-phosphate bound covalently to the oxoglutarate
carrier. Incubation of the proteoliposomes with oxoglutarate or L-malate
protected the carrier against inactivation and no radioactivity was found
associated with the carrier protein. In contrast, glutarate and substrates of
other mitochondrial carrier proteins were unable to protect the carrier.
Mersalyl, which is a known sulfhydryl reagent, also failed to protect the
oxoglutarate carrier against inhibition by pyridoxal 5'-phosphate. These results
indicate that pyridoxal 5'-phosphate interacts with the oxoglutarate carrier at a
site(s) (i.e., a lysine residue(s) and/or the amino-terminal glycine residue)
which is essential for substrate translocation and may be localized at or near
the substrate-binding site.
PMID- 10682912
TI - Oligomeric state of wild-type and cysteine-less yeast mitochondrial citrate
transport proteins.
AB - Experiments have been conducted to determine the oligomeric state of the
mitochondrial citrate transport protein (CTP) from the yeast Saccharomyces
cerevisiae. Both wild-type and cysteine-less (Cys-less) CTPs were overexpressed
in E. coli and solubilized with sarkosyl. The purity of the solubilized material
is approximately 75%. Upon incorporation into phospholipid vesicles, a high
specific transport activity is obtained with both the wild-type and Cys-less
CTPs, thereby demonstrating the structural and functional integrity of the
preparations. Two independent approaches were utilized to determine native
molecular weight. First, CTP molecular weight was determined via nondenaturing
size-exclusion chromatography. With this methodology we obtained molecular weight
values of 70,961 and 70,118 for the wild-type and Cys-less CTPs, respectively.
Second, charge-shift native gel electrophoresis was carried out utilizing a low
concentration of the negatively charged detergent sarkosyl, which served to both
impart a charge shift to the CTP and the protein standards, as well as to promote
protein solubility. Via the second method, we obtained molecular weight values of
69,122 and 74,911 for the wild-type and Cys-less CTPs, respectively. Both methods
clearly indicate that following solubilization, the wild-type and the Cys-less
CTPs exist exclusively as dimers. Furthermore, disulfide bonds are not required
for either dimer formation or stabilization. The dimeric state of the CTP has
important implications for the structural basis underlying the CTP translocation
mechanism.
PMID- 10682913
TI - Inhibitory properties of ruthenium amine complexes on mitochondrial calcium
uptake.
AB - The recent finding that the inhibition of Ca2+-stimulated respiration by
ruthenium red is mainly due to a binuclear ruthenium complex (Ru360) present in
the commercial samples of the classical inhibitor ruthenium red (Ying et. al.,
1991), showed that this complex is the more potent and specific inhibitor of the
mitochondrial calcium uniporter. This work was aimed to provide insights into the
mechanism by which Ru360 and other ruthenium-related compounds inhibits calcium
uptake. Ruthenium red and a synthesized analog (Rrphen) were compared with Ru360.
The inhibition by this binuclear complex was noncompetitive, with a Ki of 9.89
nM. The number of specific binding sites for Ru360 was 6.2 pmol/mg protein.
Ruthenium red and Ru360 were mutually exclusive inhibitors. Bound La3+ was not
displaced by Ru360. Rrphen was the least effective for inhibiting calcium uptake.
The results support the notion of a specific binding site in the uniporter for
the polycationic complexes and a negative charged region from the phospholipids
in the membrane, closely associated with the uniporter inhibitor-binding site.
PMID- 10682915
TI - Binding of rat brain hexokinase to recombinant yeast mitochondria: identification
of necessary molecular determinants.
AB - The association in vitro of rat brain hexokinase to mitochondria from rat liver
or yeast (wild type, porinless, or expressing recombinant human porin) was
studied in an effort to identify minimal requirements for each component. A short
hydrophobic N-terminal peptide of hexokinase, readily cleavable by proteases, is
absolutely required for its binding to all mitochondria. Mammalian porins are
significantly cleaved at two positions in putative cytoplasmic loops around
residues 110 and 200, as determined by proteolytic-fragment identification using
antibodies. Recombinant human porin in yeast mitochondria is more sensitive to
proteolysis than wild-type porin in rat liver mitochondria. Recombinant yeast
mitochondria, harboring several natural or engineered porins from various
sources, bind hexokinase to variable extent with marked preference for the
mammalian porin1 isoform. Genetic alteration of this isoform at the C-, but not
the N-terminal, results in a significant reduction of hexokinase binding ability.
Macromolecular crowding (dextran) promotes a stronger association of the enzyme
to all recombinant mitochondria, as well as to proteolytically digested
organelles. Consequently, brain hexokinase association with heterologous
mitochondria (yeast) in these conditions occurs to an extent comparable to that
with homologous (rat) mitochondria. The study, also pertinent to the topology and
organization of porin in the membrane, represents a necessary first step in the
functional investigation of the physiological role of mammalian hexokinase
binding to mitochondria in reconstituted heterologous recombinant systems, as
models to cellular metabolism.
PMID- 10682914
TI - Stimulation of mitochondrial gene expression and proliferation of mitochondria
following impairment of cellular energy transfer by inhibition of the
phosphocreatine circuit in rat hearts.
AB - Mitochondria proliferate when cellular energy demand increases. However, the
pathways leading to enhanced expression of mitochondrial genes are largely
unknown. We tested the hypothesis that an altered flux through energy metabolism
is the key regulatory event by decreasing mitochondrial energy supply to rat
heart cells by creatine depletion. Electron microscopy showed that the density of
mitochondria increased by 75% in such hearts (p < 0.01). Levels of representative
mRNAs encoded on mitochondrial DNA (mtDNA) or on nuclear chromosomes were
elevated 1.5 to 2-fold (p < 0.05), while the mtDNA content was unchanged. The
mRNA for the nuclear encoded mitochondrial transcription factor A (mtTFA) was
increased after GPA feeding (p < 0.05). Thus, we have shown that an impairment of
mitochondrial energy supply causes stimulation of gene expression resulting in
mitochondrial proliferation, probably as a compensatory mechanism. The observed
activation of the mtTFA gene corroborates the important function of this protein
in nuclear-mitochondrial communication.
PMID- 10682916
TI - Mitochondrial effects of triarylmethane dyes.
AB - The mitochondrial effects of submicromolar concentrations of six triarylmethane
dyes, with potential applications in antioncotic photodynamic therapy, were
studied. All dyes promoted an inhibition of glutamate or succinate-supported
respiration in uncoupled mitochondria, in a manner stimulated photodynamically.
No inhibition of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) supported
respiration was observed, indicating that these dyes do not affect mitochondrial
complex IV. When mitochondria were energized with TMPD in the absence of an
uncoupler, treatment with victoria blue R, B, or BO, promoted a dissipation of
mitochondrial membrane potential and increase of respiratory rates, compatible
with mitochondrial uncoupling. This effect was observed even in the dark, and was
not prevented by EGTA, Mg2+ or cyclosporin A, suggesting that it is promoted by a
direct effect of the dye on inner mitochondrial membrane permeability to protons.
Indeed, victoria blue R, B, and BO promoted swelling of valinomycin-treated
mitochondria incubated in a hyposmotic K+-acetate-based medium, confirming that
these dyes act as classic protonophores such as FCCP. On the other hand, ethyl
violet, crystal violet, and malachite green promoted a dissipation of
mitochondrial membrane potential, accompanied by mitochondrial swelling, which
was prevented by EGTA, Mg2+, and cyclosporin A, demonstrating that these drugs
induce mitochondrial permeability transition. This mitochondrial permeabilization
was followed by respiratory inhibition, attributable to cytochrome c release, and
was caused by the oxidation of NAD(P)H promoted by these drugs.
PMID- 10682917
TI - Myopathic mutations affect differently the inactivation of the two gating modes
of sodium channels.
AB - Three groups of mutations of the alpha subunit of the rat skeletal muscle sodium
channel (rSkM1), homologous to mutations linked to human muscle hereditary
diseases, have been studied by heterologous expression in frog oocytes: S798F,
G1299E, G1299V, and G1299A, linked with potassium-aggravated myotonia (PAM);
T1306M, R1441C and R1441P, linked with paramyotonia congenita (PC); T698M and
M1353V, linked with the hyperkalemic periodic paralysis (HyPP). Wild-type rSkM1
channels (WT) show two gating modes, M1 and M2, which differ mainly in the
process of inactivation. The naturally most representative mode M1 is tenfold
faster and develops at approximately 30 mV less depolarized potentials. A common
feature of myopathy-linked mutants is an increase in the mode M2 probability,
P(M2), but phenotype-specific alterations of voltage-dependence and kinetics of
inactivation of both modes are also observed. The coexpression of the sodium
channel beta1 subunit, which has been studied for WT and for the five best
expressing mutants, generally caused a threefold reduction of P(M2) without
changing the properties of the individual modes. This indicates that the
mutations do not affect the alpha - beta1 interaction and that the phenotypic
changes in P(M2) observed for the enhanced mode M2 behavior of the sole alpha
subunits, although largely depressed in the native tissue, are likely to be the
most important functional modification that causes the muscle hyperexcitability
observed in all patients carrying the myotonic mutations. The interpretation of
the more phenotype-specific changes revealed by our study is not obvious, but it
may offer clues for understanding the different clinical manifestations of the
diseases associated with the various mutations.
PMID- 10682918
TI - Role of pinoline and melatonin in stabilizing hepatic microsomal membranes
against oxidative stress.
AB - We investigated the influence of pinoline (0.01-1.5 mM) on microsomal membrane
fluidity before and after rigidity was induced by oxidative stress. In addition,
we tested the effect of pinoline in the presence of 1 mM melatonin. The fluidity
in rat hepatic microsomes was monitored using fluorescence spectroscopy and it
was compared to the inhibition of malonaldehyde (MDA) plus 4-hydroxyalkenals (4
HDA) production as a reflection of lipid peroxidation. Below 0.6 mM, pinoline
inhibited membrane rigidity in a manner parallel to its inhibitory effect on MDA
+ 4-HDA formation. At concentrations between 1-1.5 mM, pinoline was less
effective in stabilizing microsomal membranes than was predicted from its
inhibition of lipid peroxidation. The addition of 1 mM melatonin enhanced the
membrane-stabilizing activity of pinoline (0.01-0.6 mM). This cooperative effect
was not observed for concentrations of pinoline between 1-1.5 mM. When pinoline
was tested without induced oxidative damage, 1-1.5 mM pinoline maintained
membrane fluidity at the same level as that recorded after induced lipid
peroxidation. The results suggest that pinoline may be another pineal molecule
that prevents membrane rigidity mediated by lipid peroxidation and this ability
is enhanced by melatonin.
PMID- 10682919
TI - A quantitative approach to the evaluation of the morphological variability of two
echinostomes, Echinostoma miyagawai Ishii, 1932 and E. revolutum (Frolich, 1802),
from Europe.
AB - A comparative morphometric analysis was conducted on two European species of
Echinostoma in order to examine the degree of the variability in the metrical
characteristics of the adults and to assess their value in discriminating
species. Adult E. miyagawai and E. revolutum, obtained experimentally, were
compared using univariate and multivariate statistical analyses of 35 and 25
metrical characters, respectively. All subsets of worms of different ages
represented homogeneous samples with respect to their morphometric
characteristics; however, univariate analyses revealed significant differences in
22 and 23 variables between the corresponding age subsets of the two species, and
it was found that the different allometric growth patterns contribute to this.
The variables, body width at the posterior border of the ventral sucker, pharynx
length and width, ovary length, testes length and width and length of the pre
ovarian region, exhibited isometric or positive allometric growth in E. miyagawai
and negative allometry in E. revolutum. A cluster analysis based on 61 specimens
and 25 variables separated E. revolutum and E. miyagawai unambiguously, producing
an exact ordering of the specimens with respect to their identity and age. A
forward stepwise discriminant analysis identified five variables (body width at
the posterior border of ventral sucker, head collar width, length of oesophagus,
width of ventral sucker and length of the pre-ovarian region) which yielded a
100% accurate classification of the two species. We suggest, therefore, that the
morphometric characteristics of the adult worms should be used in studies
attempting the identification of species or isolates of Echinostoma spp. More
comparative data need to be gathered in order that the species boundaries within
the 'revolutum' group be defined more accurately.
PMID- 10682920
TI - Observations on trichodinid ectoparasites (Ciliophora: Peritricha) from the gills
of maricultured molluscs in China, with descriptions of three new species of
Trichodina Ehrenberg, 1838.
AB - During surveys of the trichodinid parasites in mariculture beds off the coast of
Shandong Province, China, four species of the genus Trichodina from the gills of
marine molluscs were investigated and morphologically studied. Of these, three
are described as new: T. ruditapicis n. sp. from Ruditapes philippinarum
(Veneridae), T. scapharcae n. sp. from Scapharca subcrenata (Arcidae) and T.
mactrae n. sp. from Mactra veneriformis (Mactridae). One little-known species, T.
macomarum Raabe & Raabe, 1959, is redescribed from M. veneriformis. Taxonomic and
morphometric data for these trichodinids based on wet silver nitrate and
protargol-impregnated specimens are presented. For each of the new species,
comparisons with closely related species are provided.
PMID- 10682921
TI - Durettechina beveridgei n. g., n. sp. (Nematoda: Seuratidae) from Antechinus spp.
(Dasyuridae: Marsupialia) from Australia.
AB - Durettechina beveridgei n. g., n. sp. (Nematoda: Seuratidae) is described from
Antechinus flavipes (Dasyuridae) from Victoria and New South Wales. A single
female from A. bellus from the Northern Territory may also be D. beveridgei. This
new genus is compared with other genera of the Echinonematinae, to which it has
been assigned. The genus has a unique body armature and most closely resembles
Chabaudechina, in the armature of the cephalic bulb, but has four rather than
five rows of hooks, and Linstowinema, in having body hooks on the cuticle of the
anterior region, but has 18-22 hooks in each row rather than 14-16. The hooks of
Durettechinca are also smaller and have a less complex root morphology than those
of Linstowinemna. Durettechina resembles Seurechinac and Chabaudechina in having
caudal alae into which papillae extend, but differs from both these genera in the
number and arrangement of the caudal papillae, as well as in the body armature.
Durettechina, is most different from Bainechina, which has neither hooks on a
cephalic bulb nor body hooks on the anterior region nor caudal alae.
PMID- 10682922
TI - Six new species of Lepidapedon Stafford, 1904 (Digenea: Lepocreadiidae) from deep
sea macrourid fishes from the Gulf of Mexico and Caribbean Sea, with revised keys
to the species of the genus.
AB - Species of the genus Lepidapecon are divided into various groups and subgroups
based on vitelline distribution relative to the acetabulum and anterior extent of
the excretory vesicle. Members of this genus predominantly parasitise gadiform
fishes and are commonly collected from relatively deep waters. A recent study of
deep-sea helminths from macrourids of the Gulf of Mexico and Caribbean Sea
revealed six new species of this genus. L. mexicanensis n. sp., of the elongatum
group, elongatum subgroup, differs from other species in this subgroup in
proportions (as % of body length), lacking confluent vitelline fields between
both the ovary and anterior testis and the testes, and in having a smaller egg
and body size. L. nezumiatis n. sp., of the elongatum group, desclersae
oesophagus than prepharynx. L. caribbaei n. sp. and L. longivesicula n. sp., of
the garrardi group, congeri sub-subgroup, differs from both L. filiformis and L.
desclersae in having intermediate egg and body sizes, and a longer group, differ
from L. congeri in having a sucker-ratio of 1: < 1. L. caribbaei n. sp. and L.
longivesicula n. sp. differ from each other in that L. caribbaei n. sp. has
numerous long, barb-like, deeply imbedded spines, a less elongate body, an
infundibuliform oral sucker, a similar-sized oesophagus and prepharynx, and a
caecal bifurcation which is closer to the acetabulum than oral sucker, while L.
longivesicula n. sp. has shorter, serrate or plate-like, lightly imbedded, widely
to sporadically spaced spines, a more elongate body, a spherical to subspherical
oral sucker, a longer oesophagus than prepharynx, and a caecal bifurcation which
is closer to the oral sucker than acetabulum. L. desotoensis n. sp., of the
rachion group, rachion subgroup, is distinct from both L. luteum and L.
abyssensis in having a smaller size, lacking cervical glands or pharyngeal gland
cells, and possessing dark-staining particles in the mesenchyme, while it differs
from L. abyssensis specifically in having a much longer oesophagus than
prepharynx, lateral vitelline fields that are not confluent intertesticularly,
and wider eggs. L. zaniophori n. sp., also of the rachion subgroup, differs from
both L. cascadensis and L. genge in having a smaller egg size, a shorter
prepharynx and oesophagus than pharynx, and vitelline fields that are
intertesticular but only slightly encroach between the ovary and anterior testis.
L. sammari and L. spiniferi are designated as incertae sedis, and L. quiloni and
L. stromateusi are designated as species inquirendae. New parasite keys and host
records for Coelorinchus coelorhincus. C. caribbaeus and Nezumia cyrano are
offered. Support is given to Lepidapedon probably being the dominant digenean
genus in deep water.
PMID- 10682923
TI - Records of the bird capillariid nematode Ornithocapillaria appendiculata
(Freitas, 1933) n. comb. from freshwater fishes in Mexico, with remarks on
Capillaria patzcuarensis Osorio-Sarabia et al., 1986.
AB - Re-examination of capillariid specimens collected from the freshwater fish
Chirostoma estor Jordan from Lake Patzcuaro in 1985-1986 and deposited as
paratypes of Capillaria patzcuarensis Osorio-Sarabia, Perez-Ponce de Leon &
Salgado-Maldonado, 1986 showed that their morphology was in contradiction with
the description of this species and, in fact, they could be identified as the
species originally described as C. appendiculata Freitas, 1933 from cormorants
Phalacrocorax brasilianus (Gm.) in Brazil; conspecific capillariid specimens were
later recorded from Chirostoma estor and Cyprinus carpio L. from the same
locality. This species and two others are transferred to Ornithocapillaria Barus
& Sergeeva, 1990 as O. appendiculata (Freitas, 1933) n. comb., O. carbonis
(Dubinin & Dubinina, 1940) n. comb., and O. phalacrocoraxi (Borgarenko, 1975) n.
comb. This is the first record of O. appendiculata in Mexico. Its occurrence in
fishes suggests that these nematodes may be acquired by their fish hosts
accidentally while feeding on cormorant excrement containing mature nematodes. A
female capillariid collected from one of 110 Chirostoma estor examined from this
locality in April, 1998 was identified as Capillaria patzcuarensis. Both
capillariid species are briefly described and illustrated.
PMID- 10682924
TI - Three new species of Polyclithrum Rogers, 1967 (Gyrodactylidae: Monogenea) from
mugilid fishes from Australia and Brazil, with a redescription of P. mugilini
Rogers, 1967.
AB - Polyclithrum mugilini Rogers, 1967, a parasite of Mugil cephalus Linnaeus, is
redescribed from type-material from Lake Seminole, Georgia, USA. Three new
species of Polyclithrum Rogers, 1967 are also described: P. alberti n. sp. from
M. cephalus from the Albert River, Queensland, Australia; P. boegeri n. sp. from
M. platanus Gunther from Rio da Guarda, State of Rio de Janeiro, Brazil; and P.
corallense n. sp. from M. cephalus from Heron Island, Great Barrier Reef,
Australia. The four species can be distinguished by the size and shape of
haptoral sclerites, but in particular by accessory bar number 3, the dorsal bar,
the marginal hooks and the hamulus point to shaft angle. The validity of
Micropolyclithrum parvum Skinner, 1975, a parasite of M. cephalus in Biscayne
Bay, Florida, is discussed, and a key to the species of Polyclithrum is
presented.
PMID- 10682925
TI - A new species and a new record of ectoparasitic mites from thrips in Turkey
(Acari: Trombidiidae and Erythraeidae).
AB - Trombidium telletxeae n. sp. is described from a larva parasitic on Odontothrips
sp. (Thysanoptera: Thripidae) from Turkey. Grandjeanella multisetosa Zhang &
Goldarazena is also reported for the first time in Turkey. A host list for
ectoparasitic larval mites on thrips in Turkey is presented.
PMID- 10682926
TI - Accuracy of stereotactic coordinate transformation using a localisation frame and
computed tomographic imaging. Part I. Influence of the mathematical and physical
properties of the CT on the image of the rods of the localisation frame and the
determination of their centres.
AB - The accuracy of coordinate transformation from the computed tomographic (CT)
space to the stereotactic frame space was analysed for frame-based stereotactic
systems which use a localisation frame and coordinate transformation based on
matrix calculation. The coordinate transformation was divided into three
consecutive steps: (1) transforming the localisation frame into the CT image
built up from pixels with distinct attenuation values, (2) determining the rod
centres of the localisation frame in the CT image, and (3) coordinate
transformation from the image to the frame space using the centres of the rods in
the image space and algebraic, matrix-based calculation. The error contribution
at each step was evaluated separately and its effect on the subsequent
mathematical operations was analysed. The first step dealt with the influences of
the mathematical and physical properties of the CT on the image of the
localisation frame. Noise, slice thickness, convolution filter, dimension of the
pixel matrix, and image processing had an influence on the attenuation values in
each pixel. Above all, the slice thickness had an effect on the shape of the
oblique rods in the CT image. At the second step, the main error contribution was
due to the method by which the centre of the rods was calculated. The most
accurate method was to determine the centre of gravity using the attenuation
values as single mass points (with accuracy in the range of +/-1/10 pixel, or +/
0.125 mm), followed by rounding off the centre of gravity and the highest pixel
value in the square matrix R2(N) within 1 pixel. Pointing with a cursor under
visual control was accurate to 1 pixel and the pixel with the highest attenuation
value showed deviations of up to 2 pixels in the x and y axes. Thus, the methods
differed by a factor of 20. The influence of the CT mathematics and physics on
the determination of the centre of the fiducials was negligible in comparison to
the method of calculation used. There was no systemic error due to the filtred
back projection algorithm. Data input errors due to noise were in the range of
1/10 pixel. The effects of the remaining physical influences were all in the
range of the error due to noise. In particular these results speak in favour of
no influence of slice thickness on coordinate transformation.
PMID- 10682927
TI - Accuracy of stereotactic coordinate transformation using a localisation frame and
computed tomographic imaging. Part II. Analysis of matrix-based coordinate
transformation.
AB - The accuracy of coordinate transformation from a CT image to a stereotactic frame
was investigated for stereotactic systems using a localisation frame and matrix
based coordinate transformation. The main source of error influencing calculation
was input data, due to inaccurate calculation of the centres of the rods of the
localisation frame in the CT image, and the propagation of this input error
during subsequent matrix calculation. Systemic errors during matrix calculation
do not exist, and rounding off errors were of subordinate importance compared to
the input data error. The influence of input data error on coordinate
transformation was studied by geometric methods, computer simulation, and
numerical analysis. In the geometric model, input data errors affected the
calculation of the centres of the three oblique rods in the frame space and
shifted them three points upwards or downwards on the axis of each rod. The three
centres of the oblique rods defined the "CT plane" in the 3D space of the
stereotactic frame. Displacements of these three centres caused a characteristic
tilting of the CT plane. The positions of the correct and tilted CT planes
defined the spatial error properties for all target points on the CT plane. The
computer simulation investigated the effects on matrix-based transformation of
all possible displacement combinations on the three oblique rods by 1 pixel (1.
16 mm) in the x and y directions. A characteristic, space-dependent distribution
of the frame-related coordinates was obtained for each target point. In the
centre of the frame, we found a maximal deviation of 1.0 mm in the xy direction
and 2 mm in the z direction. This corresponded to an error amplification of 0.73
in the xy direction and 1.22 in the z direction relative to the error at the
centres of the rods. The maximum deviation (found in the periphery) for all
combinations on the three oblique rods was 1.7 mm in the xy direction and 3.3 mm
in the z direction. This resulted in an amplification of 1.03 in the xy direction
and 2.01 in the z direction. This results had to be multiplied by 2 to obtain a
maximal error estimate for displacements including all nine rods of the
localisation frame. Numerical analysis showed stable solutions with low error
amplification for hexagonal frame arrangements.
PMID- 10682928
TI - Expression of BCL-2 oncoprotein on tumor cells and tumor-infiltrating lymphocytes
(TIL) in meningiomas.
AB - The Expression of the antiapoptotic oncoprotein BCL-2 and its correlation to
tumor grade in 62 meningiomas (48 classic, 9 atypical, and 5 anaplastic) using
single and double immunohistochemistry was investigated. BCL-2 expression was
found in two different cell populations identified as lymphocytes (BCL-2+CD3+)
and tumor cells (BCL+/CD3-). Tumor-infiltrating lymphocytes (TIL) (CD3+) were
found within classic (9.5% of cells), atypical (2.4% of cells), and anaplastic
(1.8% of cells) meningiomas. In classic meningiomas, 66.5% of TIL were BCL-2
positive, in atypical meningiomas 79.2%, and in anaplastic meningiomas 37.9%. In
33 (68.8%) of the classic meningiomas, medium to high counts of BCL-2+ tumor
cells were detected. Atypical meningiomas showed nearly equal percentages of high
(two patients), medium (five patients), and low (two patients) BCL-2+ tumor cell
counts, whereas anaplastic meningiomas showed only medium (two patients) and low
(three patients) BCL-2 tumor cell counts or were BCL-2-negative (one patient). In
summary, a significant inverse correlation between the number of BCL-2-positive
tumor cells and tumor grade in meningiomas was found. These findings support the
hypothesis of cell survival prolongation by the antiapoptotic ability of BCL-2
proto-oncogenes and demonstrate the prognostic relevance of BCL-2
immunoreactivity in meningiomas.
PMID- 10682929
TI - Evaluation of the malignancy of glioma using 11C-methionine positron emission
tomography and proliferating cell nuclear antigen staining.
AB - 11C-methionine positron emission tomography (PET) and proliferating cell nuclear
antigen (PCNA) staining were performed in 13 cases of glioma to investigate the
relationship between the uptake of L-[methyl]-11C-methionine and the degree of
malignancy and proliferative potential. The 11C-methionine uptake was
significantly greater in high-grade gliomas compared to low-grade gliomas
(P<0.05). The PCNA indexes were also significantly higher in the high-grade cases
(P<0.05). Moreover, a strong positive correlation was found between the 11C
methionine values and the PCNA indexes (P<0.005), demonstrating that higher 11C
methionine uptake was associated with greater proliferative potential and greater
malignancy. 11C-methionine PET is a potentially useful preoperative method to
discriminate the malignancy of glioma.
PMID- 10682930
TI - Fibroxanthoma arising from the cranial dura mater.
AB - A primary xanthomatous tumor is very rare in the central nervous system (CNS).
Here we report the case of a fibroxanthoma arising from the dura mater of the
cerebrum that demonstrated no systemic disease or metabolic abnormalities. A 19
month-old, otherwise healthy boy was found to have an enlarged head. Magnetic
resonance imaging demonstrated a left occipital dural mass lesion and an enlarged
left cerebral hemisphere with ipsilateral ventricular enlargement. Subtotal
removal of the tumor was performed through the left parieto-occipital craniotomy.
The tumor was composed of a central fibrous portion, a peripheral xanthomatous
area, and a boundary. The peripheral area of the tumor showed abundant uniform
xanthomatous cells with a thin fibrous stroma and the mass was diagnosed as
fibroxanthoma involving the dura. This may represent a distinct category of
tumor, which is different from the previously reported cases of fibrous xanthoma
and fibrous histiocytoma. Intracranial xanthomatous tumors may be heterogeneous
in their origin and histological features. However, further studies are needed to
elucidate their clinical features, biological behavior, and optimal treatment
strategies.
PMID- 10682931
TI - Endovascular treatment of basilar trunk aneurysm associated with fenestration of
the basilar artery.
AB - Basilar trunk saccular aneurysms associated with fenestration are infrequent,
especially in the middle or distal portion of the basilar artery. Surgical
treatment of the basilar trunk aneurysm is difficult, due to its anatomical
environment and the complicated surgical exposure. A 46-year-old woman presenting
with Hunt and Kosnik grade II subarachnoid hemorrhage was found to have a
ruptured aneurysm arising at the proximal corner of the associated fenestration
in the middle portion of the basilar artery. Because of surgical difficulties
anticipated in approaching the aneurysm, it was decided to treat it with
endovascular embolization utilizing the Guglielmi detachable coil; and complete
occlusion of the aneurysm was obtained. The efficacy of endovascular treatment
for the basilar trunk aneurysm with associated fenestration is discussed from
anatomical and embryological points of view, and relevant literature is reviewed.
PMID- 10682932
TI - Sphenoidal sinus mucocele after transsphenoidal surgery for acromegaly.
AB - This report concerns one case of a sphenoid sinus mucocele occurring 17 years
after transsphenoidal surgery for acromegaly. In 1979, a 51-year-old man was
successfully operated by the transnasal transsphenoidal approach for a growth
hormone (GH) adenoma 1 cm in diameter. In 1996, the patient was hospitalized for
headaches and diplopia. He presented a loss of right visual acuity with paralysis
of the right oculomotor nerve. The basal GH level was normal with a satisfactory
decrease after oral glucose ingestion. Pituitary sellar radiography showed a
disappearance of the posterior clinoid while magnetic resonance imaging revealed
the existence of a bilocular, circular, homogeneous lesion of the sphenoid sinus
3 cm in diameter with a posterior and lateral extension. The diagnosis of
mucocele was confirmed by surgical treatment, allowing drainage of the mucocele
through a transsphenoidal approach. The drained material was composed of sinus
epithelium containing many polynuclear and resorptive cells. Postoperatively, the
symptoms decreased dramatically, leading to full recovery of visual function and
disappearance of the headaches. Apart from the tumor recurrence, the mucocele of
the sphenoid sinus can be evoked as a possible long term complication of
transsphenoidal surgery for pituitary adenoma.
PMID- 10682933
TI - Spontaneous epidural hematoma following a shunt in an infant with congenital
factor X deficiency. Case report and literature review.
AB - The authors describe a case of an infant with congenital factor X deficiency. The
patient presented with a central nervous system hemorrhage followed by
hydrocephalus. He underwent a ventriculoperitoneal shunt and, during the
postoperative period, developed a spontaneous epidural hematoma, which was
evacuated. The clinical and pathophysiological aspects of this case are discussed
based on a literature review.
PMID- 10682934
TI - A sensitive brain retractor for neurosurgery.
PMID- 10682935
TI - Protective effect of metallothionein to ras DNA damage induced by hydrogen
peroxide and ferric ion-nitrilotriacetic acid.
AB - Metallothionein (MT) is a strong antioxidant, due to a large number of thiol
groups in the MT molecule and MT has been found in the nucleus. To investigate
whether MT can directly protect DNA from damage induced by hydroxyl radical, the
effects of MTs on DNA strand scission due to incubation with ferric ion
nitrilotriacetic acid and H2O2 (Fe3+ -NTA/H2O2) were studied. The Fe3+-NTA/H2O2
resulted in a higher rate of deoxyribose degradation, compared to incubation of
Fe3+/H2O2, presumably mediated by the formation of hydroxyl radicals (*OH). This
degradation was inhibited by either Zn-MT or Cd-MT, but not by Zn2+ or Cd2+ at
similar concentrations. The Fe3+ -NTA/H2O2 resulted in a concentration dependent
of increase in DNA strand scission. Damage to the sugar-phosphodiester chain was
predominant over chemical modifications of the base moieties. Incubation with
either Zn-MT or Cd-MT inhibited DNA damage by approximately 50%. Preincubation of
MT with EDTA and N-ethylmaleimide, to alkylate sulfhydryl groups of MT, resulted
in MT that was no longer able to inhibit DNA damage. These results indicates that
MT can protect DNA from hydroxyl radical attack and that the cysteine thiol
groups of MT may be involved in its nuclear antioxidant properties.
PMID- 10682936
TI - Toxicity and metabolism of malachite green and leucomalachite green during short
term feeding to Fischer 344 rats and B6C3F1 mice.
AB - Malachite green, an N-methylated diaminotriphenylmethane dye, has been widely
used as an antifungal agent in commercial fish hatcheries. Malachite green is
reduced to and persists as leucomalachite green in the tissues of fish. Female
and male B6C3F1 mice and Fischer 344 rats were fed up to 1200 ppm malachite green
or 1160 ppm leucomalachite green for 28 days to determine the toxicity and
metabolism of the dyes. Apoptosis in the transitional epithelium of the urinary
bladder occurred in all mice fed the highest dose of leucomalachite green. This
was not observed with malachite green. Hepatocyte vacuolization was present in
rats administered malachite green or leucomalachite green. Rats given
leucomalachite green also had apoptotic thyroid follicular epithelial cells.
Decreased T4 and increased TSH levels were observed in male rats given
leucomalachite green. A comparison of adverse effects suggests that exposure of
rats or mice to leucomalachite green causes a greater number of and more severe
changes than exposure to malachite green. N-Demethylated and N-oxidized malachite
green and leucomalachite green metabolites, including primary arylamines, were
detected by high performance liquid chromatography/mass spectrometry in the
livers of treated rats. 32P-Postlabeling analyses indicated a single adduct or co
eluting adducts in the liver DNA. These data suggest that malachite green and
leucomalachite green are metabolized to primary and secondary arylamines in the
tissues of rodents and that these derivatives, following subsequent activation,
may be responsible for the adverse effects associated with exposure to malachite
green.
PMID- 10682937
TI - Specific interactions of monotetrahydrofuranic annonaceous acetogenins as
inhibitors of mitochondrial complex I.
AB - Annonaceous acetogenins (ACG) are a wide group of cytotoxic compounds isolated
from plants of the Annonaceae family. Some of them are promising candidates to be
a future new generation of antitumor drugs due to the ability to inhibit the
NADH:ubiquinone oxidoreductase of the respiratory chain (mitochondrial complex
I), main gate of the energy production in the cell. ACG are currently being
tested on standard antitumor trials although little is known about the structure
activity relationship at the molecular level. On recent studies, the relevance of
several parts of the molecule for the inhibitory potency has been evaluated. Due
to the great diversity of skeletons included in this family of natural products,
previous studies on the presence and distribution of oxygenated groups along the
alkyl chain only covered the compounds with different bis-tetrahydrofuranic (bis
THF) relative configurations. Therefore, we have investigated the inhibitory
action of all the mono-tetrahydrofuranic (mono-THF) acetogenins available, which
differ in the oxygenated arrangements along the molecule. Our results show that
the hydroxyl and carbonyl groups, placed in the aliphatic chain that links the
initial gamma-lactone moiety with the dihydroxylated tetrahydrofuranic ring
system, significantly contribute for modulating the inhibitory potency of the ACG
through specific effects.
PMID- 10682938
TI - Identification of the zinc-binding protein specifically present in male rat liver
as carbonic anhydrase III.
AB - A zinc (Zn)-binding protein that is present specifically in the livers of male
adult rats was detected by HPLC with in-line detection by mass spectrometry (ICP
MS). The Zn-binding protein was purified on Sephadex G-75 and G3000SW HPLC
columns. and was identified as carbonic anhydrase III (CAIII) based on the amino
acid sequence of a peptide obtained on lysyl endopeptidase digestion. CAIII is
expressed as one of the major Zn-binding proteins in the livers of male rats in
an age-dependent manner, a comparable amount of Zn to that of copper, Zn
superoxide dismutase (Cu,Zn-SOD) being bound to CAIII at 8 weeks of age.
Castration at 4 or 8 weeks of age was shown to reduce Zn bound to CAIII to 47.5%
of the sham-operated control level, suggesting that the sex-dependent expression
of CAIII is partly regulated by a sex hormone, androgen. The concentration of
CAIII in the livers of Long-Evans rats with a cinnamon-like coat color (LEC
rats), an animal model of Wilson disease, was also estimated as Zn bound to CAIII
and shown to be lower than that in Wistar rats before the onset of hepatitis. The
concentration of CAIII was decreased specifically by repeated injections of
cupric ions without the Cu,Zn-SOD concentration being affected.
PMID- 10682939
TI - Daytime sleepiness predicts mortality and cardiovascular disease in older adults.
The Cardiovascular Health Study Research Group.
AB - INTRODUCTION: As part of the baseline examination in the Cardiovascular Health
Study, sleep disturbance symptoms including snoring and daytime sleepiness, were
assessed as potential risk factors or precipitants of cardiovascular disease
(CVD). Because of the association of sleep disturbance with poorer health and the
possible associations of sleep apnea with CVD, we hypothesized that those with
poorer sleep or daytime sleepiness may be at increased risk of mortality or
incident CVD. SETTING: Participants (n = 5888) were recruited in 1989, with an
additional minority cohort recruited in 1993, in four US communities for a cohort
study designed to evaluate risk factors for cardiovascular disease. METHODS: An
interview-administered questionnaire regarding health and sleep habits with
ongoing ascertainment of total mortality and cardiovascular disease morbidity and
mortality, including total CVD morbidity and mortality, incident myocardial
infarction, and congestive heart failure. RESULTS: Daytime sleepiness was the
only sleep symptom that was significantly associated with mortality in both men
and women. The unadjusted hazard ratio was 2.12 (1.66, 2.72) in women and 1.40
(1.12, 1.73) in men. Men who reported difficulty falling asleep also had an
increased mortality rate (HR = 1.43 (1.14, 1.80)) which was not seen in women.
The risks were attenuated with adjustment for age but remained significant for
daytime sleepiness in women (HR = 1.82 (1.42, 2.34)) and for difficulty falling
asleep in men. (HR = 1.29 (1.03, 1.63)). Frequent awakenings, early morning
awakening, and snoring were not associated with a significantly increased risk of
mortality in these older men and women. Crude event rates were evaluated for
total incident cardiovascular morbidity and mortality, incident myocardial
infarction, and incident congestive heart failure (CHF). Incident CVD rates were
higher in both men and women with daytime sleepiness. The aged adjusted HR was
1.35 (95% CI = 1.03, 1.76) in men and was 1.66 (95% CI = 1.28, 2.16) in women.
Incident CVD was not higher in those with any other sleep disturbance including
snoring. The risk of CVD events associated with daytime sleepiness was attenuated
but remained significant in women after adjustment for age. Incident myocardial
infarction (MI) rates were also higher in women with daytime sleepiness but were
not significantly higher in men. Incident CHF rates were increased in both men
and women with daytime sleepiness. In men, the age adjusted HR was 1.49 (95% CI,
1.12- 1.98) and in women, was 2.21 (95% CI, 1.64-2.98). Women reporting both
daytime sleepiness and frequent awakening had a hazard ratio of 2.34 (95% CI,
1.66-3.29) for incident CHF compared with those with daytime sleepiness but
without frequent awakening. This interaction was not found in men. CONCLUSIONS:
In this study, daytime sleepiness was the only sleep disturbance symptom that was
associated with mortality, incident CVD morbidity and mortality, MI, and CHF.
These findings were stronger in women than men, i.e., the associations persisted
for mortality, CVD, and CHF in women after adjustment for age and other factors.
Thus, a report of daytime sleepiness identifies older adults at increased risk
for total and cardiovascular mortality, and is an independent risk factor in
women.
PMID- 10682940
TI - Delivery of preventive services to older black patients using neighborhood health
centers.
AB - OBJECTIVES: Older black patients are at risk for underutilization of preventive
services. Our objectives were to assess the delivery of five preventive services
in Title 330-funded health centers in low income neighborhoods in Cleveland,
Ohio, and to determine the association of health system factors and health status
with the delivery of these services. DESIGN: A cross-sectional study. SETTING:
Four neighborhood health centers in low income neighborhoods of Cleveland, Ohio.
PARTICIPANTS: A total of 683 black men and women, aged 70 and older, who regarded
the health center as their primary source of outpatient care. MEASUREMENTS:
Demographic characteristics, independence in basic and instrumental activities of
daily living, comorbidity scores, and perceived access were determined by
telephone interview. We reviewed charts to determine whether each of five
preventive service goals were obtained: influenza vaccination within 1 year;
pneumococcal vaccination at any time; mammography within 2 years; Papanicolau
screening within 1 year or twice at any time in the past with documentation of
normal results; and fecal occult blood testing within 2 years. RESULTS: The
defined goals for influenza vaccination, pneumococcal vaccination, mammography,
Papanicolau screening, and fecal occult blood testing were achieved for 59%, 64%,
59%, 51%, and 17% of patients, respectively. Influenza and pneumococcal vaccines
were obtained more often in persons with greater comorbidity. Mammography and
Papanicolau smear were obtained more often in patients without of ADL or IADL
impairments. The four clinical sites varied substantially in the delivery of each
preventive service. More frequent office visits were associated with greater
delivery of all five preventive services. This relationship persisted in
multivariable analyses controlling for health status and clinical site.
CONCLUSIONS: This study shows that Title 330 federally supported neighborhood
health center sites providing primary care to older blacks in Cleveland achieved
high rates of performance in four of the five recommended preventive services. In
addition, preventive services practices were associated with prognostically
relevant health status information. The frequency of office visits was related
strongly and consistently to the performance of the various preventive services,
indicating that more, not fewer, office visits may be necessary to achieve
Healthy People 2000 targets. J Am Geriatr Soc 48:124-130, 2000. Key words:
preventive services; blacks; access to care; geriatrics; primary care
PMID- 10682941
TI - Long-term exercise and its effect on balance in older, osteoarthritic adults:
results from the Fitness, Arthritis, and Seniors Trial (FAST).
AB - OBJECTIVES: To examine the effects of 18-month aerobic walking and strength
training programs on static postural stability among older adults with knee
osteoarthritis. DESIGN: Randomized, single-blind, clinical trial of therapeutic
exercise. SETTING: Both center-based (university) and home-based. PARTICIPANTS: A
cohort of 103 older adults (age = 60 years) with knee osteoarthritis who were
participants in a large (n = 439) clinical trial and who were randomly assigned
to undergo biomechanical testing. INTERVENTION: An 18-month center- (3 months)
and home-based (15 months) therapeutic exercise program. The subjects were
randomized to one of three treatment arms: (1) aerobic walking; (2) health
education control; or (3) weight training. MEASUREMENTS: Force platform static
balance measures of average length (Rm) of the center of pressure (COP), average
velocity (Vel) of the COP, elliptical area (Ae) of the COP, and balance time (T).
Measures were made under four conditions: eyes open, double- and single-leg
stances and eyes closed, double- and single-leg stances. RESULTS: In the eyes
closed, double-leg stance condition, both the aerobic and weight training groups
demonstrated significantly better sway measures relative to the health education
group. The aerobic group also demonstrated better balance in the eyes open,
single-leg stance condition. CONCLUSIONS: Our results suggest that long-term
weight training and aerobic walking programs significantly improve postural sway
in older, osteoarthritic adults, thereby decreasing the likelihood of larger
postural sway disturbances relative to a control group.
PMID- 10682942
TI - The relationship between aerobic exercise capacity and circulating IGF-1 levels
in healthy men and women.
AB - OBJECTIVES: To determine whether aerobic capacity is associated independently
with insulin-like growth factor-I (IGF-1) levels in healthy community-dwelling
men and women. SETTING: The Baltimore Longitudinal Study on Aging (BLSA). DESIGN:
A cross-sectional analysis of data from the population-based cohort of the
Baltimore Longitudinal Study of Aging (BLSA). PARTICIPANTS: We studied 181 men
and 92 women aged 20 to 93 years, volunteers in the Baltimore Longitudinal Study
on Aging (BLSA). Subjects were free of endocrine, renal, hepatic,
gastrointestinal, or cardiac diseases, and they were taking no medications known
to interfere with the growth hormone-IGF-1 axis. MEASUREMENTS: All subjects
underwent a single measurement of serum IGF-1 in the fasting state, as well as
peak VO2 determinations during maximal treadmill exercise testing performed
within one visit of the IGF-1 determination. Dual energy X-ray absorptiometry
(DEXA) scans were performed in a subset of 171 subjects (64 women and 107 men)
for determination of fat free mass (FFM). RESULTS: In the pooled group of women
and men, univariate regression analysis revealed that age was correlated strongly
with decreasing IGF-1 levels (r = -0.53, P < .001) and with peak VO2r = -0.56, P
< .001). IGF-1 levels were also significantly correlated with peak VO2 (r = 0.29,
P < .001). There were no significant gender-related differences in these
relationships. On multivariate analysis, age (beta = -0.54, P < .001), but not
peak VO2 (P = -0.01, P = .840), remained strongly associated with IGF-1 levels.
After adjustment of peak VO2 for FFM in subjects with DEXA scans, results were
similar. CONCLUSIONS: These findings indicate that although both peak aerobic
capacity and circulating IGF-1 levels decline with age, aerobic capacity is not
independently related to circulating IGF-1 in healthy men and women across the
adult life span.
PMID- 10682943
TI - Determinants of exercise tolerance after acute myocardial infarction in older
persons.
AB - OBJECTIVES: Exercise tolerance is reduced with advancing age. Identification of
potentially reversible determinants of the age-related decrement in exercise
tolerance, which remain largely unexplored in older subjects and in patients
recovering from a recent myocardial infarction (MI), may have useful therapeutic
implications. The objective of this study was to identify the independent
determinants of exercise tolerance in older patients with a recent MI. DESIGN,
SETTING, AND PARTICIPANTS: Data is from baseline assessment of 265 post-MI
patients (age range 45-85 years) enrolled in the Cardiac Rehabilitation in
Advanced Age randomized, controlled trial. Patients with major comorbidities or
severe MI complications were excluded from the trial. Exercise tolerance was
determined from symptom-limited exercise testing and expressed as total work
capacity (TWC, kg.m) or peak oxygen consumption (VO2peak, mL/kg/min). The
associations between both TWC and VO2peak and baseline demographic, social,
clinical, and neuropsychological variables and an index of health-related quality
of life were determined with univariate and multivariate analysis. RESULTS: With
univariate analysis, TWC decreased by 1285 kg.m per decade of increasing age
between 45 and 85 years of age. With multivariate analysis, TWC decreased by 922
kg.m per decade. Increasing age (P < .001), female gender (P < .001), a small
body surface area (P < .001), a low level of usual physical exercise before MI (P
< .002), and the presence of post-MI depressive symptoms (P < .024) were
independently associated with a lower TWC. The same factors, in addition to a
small arm muscle area (P < .002), were also independently associated with a lower
VO2peak. CONCLUSIONS: Age per se accounts for approximately 70% of the age
related decay in TWC or VO2peak. However, the inclusion of modifiable factors
such as physical exercise and depression in the prediction model reinforces the
importance of a multidimensional approach to the evaluation and treatment of
older patients with a recent MI.
PMID- 10682944
TI - Appropriateness of the decision to transfer nursing facility residents to the
hospital.
AB - OBJECTIVES: To develop and test a standardized instrument, the purpose of which
is to assess (1) whether skilled nursing facilities (SNFs) transfer residents to
emergency departments (ED) inappropriately, (2) whether residents are admitted to
hospitals inappropriately, (3) and factors associated with inappropriate
transfers. DESIGN: A structured implicit review (SIR) of medical records. SETTING
AND PARTICIPANTS: Using nested random sampling in eight community SNFs, we
identified SNF and hospital records of 100 unscheduled transfers to one of 10
hospitals. MEASUREMENTS: Seven trained physician reviewers assessed
appropriateness using a SIR form designed for this study (2 independent reviews
per record, 200 total reviews). We measured interrater reliability with kappa
statistics and used bivariate analysis to identify factors associated with
assessment that transfer was inappropriate. RESULTS: In 36% of ED transfers and
40% of hospital admissions, both reviewers agreed that transfer/admit was
inappropriate, meaning the resident could have been cared for safely at a lower
level of care. Agreement was high for both ED (percent agreement 84%, kappa .678)
and hospital (percent agreement 89%, kappa .779). When advance directives were
considered, both reviewers rated 44% of ED transfers and 45% of admissions
inappropriate. Factors associated with inappropriateness included the perceptions
that: (1) poor quality of care contributed to transfer need, (2) needed services
would typically be available in outpatient settings, and (3) the chief complaint
did not warrant hospitalization. CONCLUSIONS: Inappropriate transfers are a
potentially large problem. Some inappropriate transfers may be associated with
poor quality of care in SNFs. This study demonstrates that structured implicit
review meets criteria for reliable assessment of inappropriate transfer rates.
Structured implicit review may be a valuable tool for identifying inappropriate
transfers from SNFs to EDs and hospitals.
PMID- 10682945
TI - Functional status before hospitalization in acutely ill older adults: validity
and clinical importance of retrospective reports.
AB - OBJECTIVES: Retrospective reports of patients' functional status before hospital
admission are often used in longitudinal studies and by clinicians caring for
hospitalized patients. However, the validity of these reports has not been
established. Our aim was to examine the validity of retrospective reports by
testing hypotheses about the relationships these measures would have with other
clinical measures if they were valid. DESIGN: A prospective cohort study.
PARTICIPANTS AND SETTING: A total of 2877 older patients (mean age 81, 36% women)
hospitalized on the general medical service at two hospitals. For 1953 of the
subjects, the patient was the primary respondent, whereas for 924 subjects, a
surrogate was the primary respondent. MEASUREMENTS: Shortly after hospital
admission, patients or surrogates reported whether the patient was independent in
each of five activities of daily living (ADLs) on admission and at baseline 2
weeks before admission. Outcome measures included reported independence in each
ADL 3 months after the hospitalization and survival to 1 year. RESULTS: Patients'
retrospective reports of their ADL function 2 weeks before admission had a
clinically plausible relationship with ADL function at the time of admission, in
that patients independent in an ADL on admission rarely reported they were
dependent in that ADL 2 weeks before admission (range 2-6%). Surrogates were
somewhat more likely than patients to report that patients independent on
admission were dependent 2 weeks before admission (range 5-14%). Retrospective
reports of prehospitalization ADL function demonstrated strong evidence of
predictive validity for both patients' and surrogates' reports. For example,
among patients dependent in bathing on admission, patients who were reported as
independent 2 weeks before admission were much more likely than those reported as
dependent 2 weeks before admission to be independent 3 months after
hospitalization (68% vs 20%, P < .001 for patient respondents; 30% vs 5%, P <
.001 for surrogate respondents). Similarly, among patients dependent in bathing
on hospital admission, survival 1 year after hospitalization was much higher in
patients who were independent in bathing 2 weeks before admission than patients
who were dependent 2 weeks before admission (76% vs 59%, P < .001 for patient
respondents; 60% vs 45%, P < .001 for surrogate respondents). Results were
similar for each of the other four ADLs. In a logistic regression model
controlling for the number of ADLs reported as dependent on admission, the number
of ADLs reported as dependent 2 weeks before admission was significantly
associated with 1-year mortality among both patient (odds ratio (OR) = 1.39 per
dependent ADL, 95% confidence interval (CI) - 1.26-1.54) and surrogate (OR =
1.14, 95% CI = 1.06-1.24) respondents. CONCLUSIONS: Hospitalized patients'
assessments of their ability to perform ADLs before their hospitalization have
evidence of face and predictive validity. These measures are strong predictors of
important health outcomes such as functioning and survival. In particular, among
patients dependent in ADL function on hospital admission, these results highlight
the prognostic importance of inquiring about the patient's functional status
before the onset of the acute illness.
PMID- 10682946
TI - Modifiable risk factors predict functional decline among older women: a
prospectively validated clinical prediction tool. The Study of Osteoporotic
Fractures Research Group.
AB - OBJECTIVE: To identify modifiable predictors of functional decline among
community-residing older women and to derive and validate a clinical prediction
tool for functional decline based only on modifiable predictors. DESIGN: A
prospective cohort study. SETTING: Four geographic areas of the United States.
PARTICIPANTS: Community-residing women older than age 65 recruited from
population-based listings between 1986 and 1988 (n = 6632). MEASUREMENTS:
Modifiable predictors were considered to be those that a clinician seeing an
older patient for the first time could reasonably expect to change over a 4-year
period: benzodiazepine use, depression, low exercise level, low social
functioning, body-mass index, poor visual acuity, low bone mineral density, slow
gait, and weak grip. Known predictors of functional decline unlikely to be
amenable to intervention included age, education, medical comorbidity, cognitive
function, smoking history, and presence of previous spine fracture. All variables
were measured at baseline; only modifiable predictors were candidates for the
prediction tool. Functional decline was defined as loss of ability over the 4
year interval to perform one or more of five vigorous or eight basic daily
activities. RESULTS: Slow gait, short-acting benzodiazepine use, depression, low
exercise level, and obesity were significant modifiable predictors of functional
decline in both vigorous and basic activities. Weak grip predicted functional
decline in vigorous activities, whereas long-acting benzodiazepine use and poor
visual acuity predicted functional decline in basic activities. A prediction rule
based on these eight modifiable predictors classified women in the derivation set
into three risk groups for decline in vigorous activities (12%, 25%, and 39%
risk) and two risk groups for decline in basic activities (2% and 10% risk). In
the validation set, the probabilities of functional decline were nearly
identical. CONCLUSIONS: A substantial portion of the variation of functional
decline can be attributed to risk factors amenable to intervention over the short
term. Using eight modifiable predictors that can be identified in a single office
visit, clinicians can identify older women at risk for functional decline.
PMID- 10682947
TI - Decision-making capacity to execute a health care proxy: development and testing
of guidelines.
AB - OBJECTIVE: To evaluate the reliability and validity of guidelines to determine
the capacity of nursing home residents to execute a health care proxy (HCP).
DESIGN: A cross-sectional study. SETTING: A 750-bed not-for-profit nursing home
located in New York City. PARTICIPANTS: A random sample of 200 nursing home
residents: average age, 87; 99% white; 83% female; average length of stay, 3.05
years; mean Mini-Mental State Exam (MMSE) score, 15.9. MEASUREMENTS: Demographic
characteristics (Minimum Data Set (MDS)); function and cognitive status
(Institutional Comprehensive Assessment and Referral Evaluation (INCARE));
Reisberg Dementia Staging; MMSE; Minimum Data Set-Cognitive Performance Scale
(MDS-COGS)); an investigator-developed measure of a nursing home resident's
capacity to execute a health care proxy (Health Care Proxy (HCP) Guidelines.)
RESULTS: The internal consistency of the decision-making scales in the HCP
Guidelines, paraphrased recall and recognition, reached acceptable levels, alphas
of .85 and .73, respectively. Interrater reliability estimates were .92 and .94,
respectively, for the recall and recognition scales; test-retest reliability
estimates were .83 and .90. The discriminant validity of these scales is
promising. For example, the MMSE correlation was .51 with the Recall scale and
.57 with the Recognition scale. Of residents with severe cognitive impairment
(MMSE < 10), 71% completed 50% or more of the scaled items in the HCP guidelines
and 95% consistently named a proxy. CONCLUSIONS: Seventy-three percent of
testable residents, approximately three-quarters of whom were cognitively
impaired, evidenced sufficient capacity to execute an HCP. Of residents with
severe cognitive impairment, the HCP guidelines are potentially useful in
identifying those with the capacity to execute a HCP. The guidelines are more
predictive than the MMSE in identifying residents able to execute a HCP.
PMID- 10682948
TI - Physicians are less willing to treat suicidal ideation in older patients.
AB - OBJECTIVE: Older adults have the highest rate of suicide of any age group, and
reducing the number of late-life suicides has become a national priority. The
objective of this study was to determine if an age bias exists among primary care
physicians when they contemplate treating suicidal patients. DESIGN: Primary care
providers were mailed one of two case vignettes of a suicidal, depressed patient.
The only difference between the two vignettes was the age of the patient (38 or
78 years old) and employment status (employed vs retired as a factory worker). A
questionnaire was included to determine provider recognition of suicidal
ideation, and a scale was designed to detect willingness to treat the vignette
patient. SETTING/PARTICIPANTS: Physicians were selected randomly from the
University of California, San Francisco physician roster and invited to
participate in the study. A total of 342 physicians (63% response rate),
including specialists, responded to the mailings. For this study, the responses
of 215 primary care physicians were analyzed. INTERVENTION: The randomly assigned
experimental group received a vignette of a geriatric, retired patient who was
depressed and suicidal (n = 100 participants). The control group received an
identical but younger, employed patient (n = 115 participants). MEASUREMENTS: A
21-item Suicidal Patient Treatment Scale measured willingness to treat the
suicidal patient. RESULTS: The physicians in this study recognized depression and
suicidal risk in both the adult and the geriatric vignette, but they reported
less willingness to treat the older suicidal patient compared with the younger
patient. The physicians were more likely to feel that suicidal ideation on the
part of the older patient was rational and normal. They were less willing to use
therapeutic strategies to help the older patient, and they were not optimistic
that psychiatrists or psychologists could help the suicidal patient. CONCLUSIONS:
This study suggests that primary care physicians are capable of recognizing
suicidal ideation but are less willing to treat it if the patient is older and
retired. Future research needs to determine etiologic factors for this age bias.
PMID- 10682949
TI - Aging is associated with endothelial dysfunction in the human forearm
vasculature.
AB - OBJECTIVE: Our objective was to examine the role of the endothelium in
maintaining vascular tone in the basal as well as in the contracted state during
aging. DESIGN/PARTICIPANTS: Responses to brachial artery infusion of
acetylcholine in presence and absence of NG-nitro-L-arginine methyl ester (L
NAME) and to angiotensin II were studied in 11 young and 12 old white subjects.
MEASUREMENTS: Strain gauge plethysmography was used to measure forearm vascular
resistance (FVR). The dose of acetylcholine at 50% maximal observed decrease in
forearm vascular resistance (EC50) was significantly higher (11.0 +/- 1.59 vs
7.07 +/- .65 microg/min, respectively; mean +/-SEM; P < .05) and the FVR at
maximal acetylcholine effect (Emax) remained greater (12.6 +/- 1.75 vs 7.15 +/-
1.25 mm Hg/100 mL tissue volume/min; P < .02) in old compared with young
subjects. Acetylcholine effect was significantly reversed by concomitant
administration of L-NAME, as indicated by the increase in EC50 (old, 20.2 +/-
3.69; young, 11.9 +/- 1.68 microg/min). RESULTS: There was no age-related
difference in sodium nitroprusside-induced decrease in FVR. The EC50 and Emax for
angiotensin II-mediated increase in FVR were 7.87 +/- 1.15 and 8.36 +/- 1.00
ng/min (EC50) and 5.30 +/- .67 vs 6.56 +/-1.25 mm Hg/100 mL tissue volume/min
(Emax), and these were not different in old and young subjects, respectively.
CONCLUSIONS: These data indicate that aging is associated with impaired
endothelial- dependent vascular relaxation and that this is selective, with no
age-related change in endothelial-independent vascular relaxation or angiotensin
II-mediated vascular contraction.
PMID- 10682950
TI - The effects of childhood residence in Japan and testing language on cognitive
performance in late life among Japanese American men in Hawaii.
AB - OBJECTIVES: To examine the association of years spent in Japan during childhood
with cognitive test performance in late life among Japanese American men, and to
assess the influence of the language used for testing on this association.
DESIGN: A cross-sectional study. SETTING/PARTICIPANTS: A total of 3734 Japanese
American men, aged 71-93 years, who were first- or second-generation migrants and
living on Oahu Island, Hawaii. MEASUREMENTS: The outcome variable was cognitive
test performance assessed using the Cognitive Abilities Screening Instrument
(CASI), which was developed for cross-cultural studies of cognitive impairment.
The explanatory variable of main interest was the number of years spent in Japan
during school-age childhood years (ages 6-17). The associations of CASI scores
with childhood years in Japan was evaluated using a stepwise multiple linear
regression model in which a total of 40 potential confounders were included as
covariates. RESULTS: In the total sample, there was an inverse association
between CASI scores and middle childhood years in Japan. This association
remained significant after controlling for age, education, socioeconomic status,
traditional Japanese food consumption, pulmonary function, apolipoprotein E4,
proficiency in speaking Japanese, and other possible confounders. When data were
analyzed separately for subgroups according to the language preferred at testing
(English or Japanese), associations between childhood years in Japan and CASI
scores were in opposite directions negative for the group tested in English and
positive for the group tested in Japanese. The interaction between the testing
language and childhood years in Japan was statistically significant. CONCLUSIONS:
There was an inverse association between years spent in Japan during school-age
years of childhood and cognitive test performance in late life. This association
could not be accounted for by age, education, or other confounding factors.
However, this finding was not observed in participants who preferred being tested
in Japanese. To assess cognitive test performance in older people, it is of prime
importance to use the most optimal language for testing, usually the subject's
native language.
PMID- 10682951
TI - The high prevalence of depression and dementia in elder abuse or neglect.
AB - BACKGROUND: The risk factors for mistreatment of older people include age, race,
low income, functional or cognitive impairment, a history of violence, and recent
stressful events. There is little information in the literature concerning the
clinical profile of mistreated older people. OBJECTIVES: To describe the
characteristics of abused or neglected patients and to compare the prevalence of
depression and dementia in neglected patients with that of patients referred for
other reasons. DESIGN: A case control study. SETTING: Baylor College of Medicine
Geriatrics Clinic at the Harris County Hospital District (Houston, Texas).
PATIENTS: Forty-seven older persons referred for neglect and 97 referred for
other reasons. INTERVENTION: Comprehensive geriatric assessment. MEASUREMENTS:
Standard geriatric assessment tools. RESULTS: There was a statistically
significant higher prevalence of depression (62% vs 12%) and dementia (51% vs
30%) in victims of self-neglect compared to patients referred for other reasons.
CONCLUSIONS: This is the first primary data study that highlights a high
prevalence of depression as well as dementia in mistreated older people.
Geriatric clinicians should rule out elder neglect or abuse in their depressed or
demented patients.
PMID- 10682952
TI - Nutritional intake monitoring for nursing home residents: a comparison of staff
documentation, direct observation, and photography methods.
AB - BACKGROUND: The current approach to assessing nutritional intake requires nursing
home (NH) staff to document total percentage of food and fluid consumed at each
meal. Because NH staff tend to significantly overestimate total food intake,
methods need to be developed to improve the accuracy of food intake measurement.
OBJECTIVE: To compare three methods of assessing the nutritional intake of NH
residents. RESEARCH DESIGN: Validation Study. SUBJECTS: Fifty-six NH residents in
one facility. MEASURES: Total percentage of food and fluid intake of each
resident for each of nine meals, or all three meals for 3 consecutive days, was
assessed by: (1) Nursing home staff chart documentation, (2) Research staff
documentation according to direct observations, and (3) Research staff
documentation according to photographs of residents' trays before and after each
meal. RESULTS: Research staff documentation of total intake and intake of all
individual food and fluid items was similar for the direct observation and
photography methods. In comparison with these two methods, NH staff documentation
reflected a significant overestimate (22%) of residents' total intake levels. In
addition, NH staff failed to identify the more than half (53%) of those residents
whose intake levels were equal to or below 75% for most meals. CONCLUSIONS: The
photography method of nutritional assessment yielded the same information as
direct observations by research staff, and both of these methods showed the
intake levels of NH residents to be significantly lower than the intake levels
documented by NH staff. The photography method also has several advantages over a
documentation system that relies on an observer to be present to record food and
fluid intake levels.
PMID- 10682953
TI - Health care for older persons, a country profile: The Netherlands.
PMID- 10682954
TI - The implementation of the EverCare demonstration project.
AB - EverCare represents a creative approach to providing medical services to long
stay nursing home patients. It offers a capitated package of Medicare-covered
services with more intensive primary care provided by nurse practitioners. The
program's underlying premise is that better primary care will result in reduced
hospital use. This work examines the implementation of the program in six
locations. It identifies some of the issues that must be addressed if the program
is to succeed both operationally and financially.
PMID- 10682955
TI - The use of oral anticoagulants (warfarin) in older people. AGS Clinical Practices
Committee. American Geriatric Society.
PMID- 10682956
TI - Ask about daytime sleepiness!
PMID- 10682957
TI - Inappropriate hospitalization of nursing facility residents: a symptom of a sick
system of care for frail older people.
PMID- 10682958
TI - Hydroxyurea-induced cutaneous ulceration in older patients.
PMID- 10682959
TI - Subclinical hypothyroidism in a biethnic, urban community.
PMID- 10682960
TI - Subclinical hypothyroidism.
PMID- 10682962
TI - Subclinical hypothyroidism in a bi-ethnic, urban community
PMID- 10682961
TI - Subclinical hypothyroidism in a bi-ethnic, urban community.
PMID- 10682963
TI - Optical coherence tomography and scanning laser polarimetry in normal, ocular
hypertensive, and glaucomatous eyes.
AB - PURPOSE: To evaluate the relationship between visual function and retinal nerve
fiber layer measurements obtained with scanning laser polarimetry and optical
coherence tomography in a masked, prospective trial. METHODS: Consecutive normal,
ocular hypertensive, and glaucomatous subjects who met inclusion and exclusion
criteria were evaluated. Complete ophthalmologic examination, disk photography,
scanning laser polarimetry, optical coherence tomography, and automated
achromatic perimetry were performed. RESULTS: Seventy-eight eyes of 78 patients
(17 normal, 23 ocular hypertensive, and 38 glaucomatous) were enrolled (mean age,
56.8+/-11.5 years; range, 26 to 75 years). Eyes with glaucoma had significantly
greater neural network scores on scanning laser polarimetry and lower maximum
modulation, ellipse modulation, and mean retinal nerve fiber layer thickness
measured with optical coherence tomography compared with normal and ocular
hypertensive eyes, respectively (all P<.005). Significant associations were
observed between neural network number (r = -.51, r = .03), maximum modulation (r
= .39, r = -.32), ellipse modulation (r = .36, r = -.28), and optical coherence
tomography-generated retinal nerve fiber layer thickness (r = .68, r = -.59) and
visual field mean deviation and corrected pattern standard deviation,
respectively. All scanning laser polarimetry parameters were significantly
associated with optical coherence tomography-generated retinal nerve fiber layer
thickness. CONCLUSION: Optical coherence tomography and scanning laser
polarimetry were capable of differentiating glaucomatous from nonglaucomatous
populations in this cohort; however considerable measurement overlap was observed
among normal, ocular hypertensive, and glaucomatous eyes. Retinal nerve fiber
layer structural measurements demonstrated good correlation with visual function,
and retinal nerve fiber layer thickness by optical coherence tomography
correlated with retardation measurements by scanning laser polarimetry.
PMID- 10682964
TI - The long-term safety and efficacy of brinzolamide 1.0% (azopt) in patients with
primary open-angle glaucoma or ocular hypertension. The Brinzolamide Long-Term
Therapy Study Group.
AB - PURPOSE: Oral carbonic anhydrase inhibitors used to treat glaucoma have
significant systemic side effects. Brinzolamide 1.0%, a new topical ocular
carbonic anhydrase inhibitor, is effective apparently without significant
systemic side effects. This study was performed to establish the long-term safety
and efficacy of brinzolamide 1.0% two and three times daily for primary open
angle glaucoma and ocular hypertension. METHODS: An 18-month, multicenter, double
masked, parallel, controlled study was conducted. Patients were randomized to
brinzolamide two or three times daily or timolol 0.5% twice daily in a 2:2:1
ratio (n = 150, 153, and 75, respectively). Intraocular pressure was measured at
8:00 AM at eligibility and months 1, 3, 6, 9, 12, 15, and 18. Efficacy was based
on intraocular pressure reduction from baseline. Safety was also evaluated.
RESULTS: All regimens produced clinically relevant and statistically significant
(P<.05) intraocular pressure reductions from baseline. Mean changes in
intraocular pressure trough measurements ranged from -2.7 to -3.9 mm Hg with
brinzolamide twice-daily dosing and -2.8 to -3.8 mm Hg three times daily dosing
compared with -4.7 to -5.6 mm Hg with timolol. The intraocular pressure
reductions with brinzolamide two and three times daily were clinically and
statistically equivalent. One hundred forty-four patients were discontinued from
the study after randomization with the most common reasons being the occurrence
of an adverse event (46), inadequate intraocular pressure control (23), patient
decision unrelated to study medication (11), lost to follow-up (16), and
noncompliance (9). Adverse events were nonserious and resolved without sequelae.
There were no clinically relevant changes in safety parameters. Brinzolamide
produced less ocular discomfort (burning/stinging) than timolol, and total
carbonic anhydrase inhibition levels remained below that known to cause systemic
side effects. CONCLUSION: Brinzolamide produced significant and equivalent
reductions in intraocular pressure when dosed two and three times daily for 18
months. Brinzolamide was safe and well tolerated by patients, with minimal ocular
discomfort.
PMID- 10682965
TI - Dorzolamide and corneal recovery from edema in patients with glaucoma or ocular
hypertension.
AB - PURPOSE: To investigate whether dorzolamide alters corneal hydration control in
patients with glaucoma or ocular hypertension. METHODS: Pachymetry, tonometry,
and endothelial cell density were measured by a masked observer in 19 subjects
with bilateral glaucoma or ocular hypertension. They were treated with 2%
dorzolamide in one eye, and with saline in the other, before wearing contact
lenses under patched eyes. Corneal thickness, measured each 30 minutes up to 4.5
hours after contact lens removal, enabled estimation of percentage recovery per
hour and time for 95% of corneal thickness recovery for both eyes. Seven patients
repeated this test after 1 year of dorzolamide use, and their results were
compared with those of the preceding year. RESULTS: After induction of hypoxic
corneal edema, there was no significant difference between paired corneas in
swelling levels (60.0+/-11.8 and 59.8+/-12.9 microm) (P = .94), time to 95%
recovery (440.6+/-255.8 and 445.4+/-186.7 minutes) (P = .93), and percentage
recovery per hour (38.1%+/-10.9% and 36.1%+/-9.6%) (P = .40). Subjects followed
up after 1 year of dorzolamide use did not differ significantly in values of
endothelial cell density, percentage recovery per hour, or time to 95% recovery
from those obtained a year before. One subject developed persistent corneal edema
after his stress test in the eye treated with dorzolamide. CONCLUSION: There is
no significant difference in the recovery from induced corneal edema after either
a short-term or 1-year use of dorzolamide in patients with glaucoma or ocular
hypertension with a normal corneal endothelium. One patient had persistent
corneal edema after the stress test was performed on the dorzolamide-treated eye.
PMID- 10682966
TI - Tear and serum soluble leukocyte activation markers in conjunctival allergic
diseases.
AB - PURPOSE: To measure markers of leukocyte activation in patients with an
exclusively ocular inflammatory or bacterial disease. METHODS: Neutrophil
myeloperoxidase, eosinophil cationic protein, eosinophil neurotoxin, and soluble
interleukin-2 receptor were measured in serum and tears of 17 patients with
allergic vernal keratoconjunctivitis, seven with atopic keratoconjunctivitis, 11
with seasonal allergic conjunctivitis, seven with giant papillary conjunctivitis,
13 with rosacea blepharokeratoconjunctivitis, seven with bacterial
conjunctivitis, and 13 normal subjects as controls. RESULTS: In serum of patients
with vernal and atopic keratoconjunctivitis, levels of eosinophil cationic
protein, eosinophil neurotoxin, and interleukin-2 receptor were significantly
increased compared with control subjects but were not correlated with the
severity of ocular symptoms. In tears of patients with vernal and atopic
keratoconjunctivitis and seasonal allergic conjunctivitis, as well as in the
nonallergic diseases, rosacea blepharokeratoconjunctivitis and bacterial
conjunctivitis, levels of eosinophil cationic protein, neurotoxin, and
interleukin-2 receptor were significantly increased compared with control
subjects. The highest values of these markers were found in vernal
keratoconjunctivitis samples. Neutrophil myeloperoxidase was significantly
increased in vernal and atopic keratoconjunctivitis, rosacea
blepharokeratoconjunctivitis, and bacterial conjunctivitis. In vernal
keratoconjunctivitis, tear markers were correlated to the clinical score of the
disease, but not with cytology. CONCLUSIONS: Tear histamine was measured in 10
allergic patients after allergen challenge. Although none of the above markers
can be considered specific to a single disease, their measurement may still be
useful for the quantification of local cell activation in ocular inflammatory
diseases.
PMID- 10682967
TI - Genetically distinct autosomal dominant posterior polar cataract in a four
generation Japanese family.
AB - PURPOSE: To describe the clinical findings of a form of posterior polar cataract
in a large Japanese family and to determine whether the posterior polar cataract
is causally related to other autosomal dominant cataracts with known genes,
chromosomal locations, or both. METHODS: Systemic and ocular histories were
obtained and comprehensive ophthalmic examinations were performed in 15 of 37
members of the Japanese family. The posterior polar cataract was transmitted in
an autosomal dominant manner through four generations. Although there is some
variation in the degree of opacification, the posterior polar cataract in this
family is characterized by progressive disk-shaped posterior subcapsular
opacities. Genetic linkage analysis was performed with 41 polymorphic
microsatellite markers located in chromosomal regions known for linkage to
cataracts. Genomic DNA extracted from the 15 individuals was amplified by
polymerase chain reaction, the genotype at the marker loci was determined in each
family member, and the lod score was calculated at each locus. RESULTS:
Significant linkage of the posterior polar cataract was ruled out from the
following 10 loci or chromosomal regions: 16q22 and 1p36, to which two forms of
autosomal dominant posterior polar cataract have been assigned: 1q21-q25, 2q33
q35, 13cen, 17p13, 17q11-q12, 17q24, 21q22, and 22q, which are the regions
responsible for other autosomal dominant congenital cataracts. CONCLUSIONS: This
study confirms the genetic heterogeneity of autosomal dominant posterior polar
cataracts and demonstrates that the posterior polar cataract in this Japanese
family is phenotypically and genetically distinct from previously mapped
cataracts.
PMID- 10682968
TI - Viral causes of the acute retinal necrosis syndrome.
AB - PURPOSE: The primary goal of this study was to determine the viral cause of the
acute retinal necrosis syndrome in 28 patients (30 eyes). A secondary goal was to
investigate possible associations between viral cause and patient age, and viral
cause and central nervous system disease. METHODS: A retrospective case series in
which we reviewed the laboratory results and clinical histories of 28 patients
(30 eyes) diagnosed with acute retinal necrosis syndrome, from whom vitreous or
aqueous specimens were received, for diagnostic evaluation using previously
described polymerase chain reaction-based assays. RESULTS: Varicella-zoster
virus, herpes simplex virus, and cytomegalovirus (CMV) DNA were detected in
aqueous and/or vitreous specimens from 27 of 28 patients (29 of 30 eyes with a
clinical history of acute retinal necrosis syndrome). No sample was positive for
DNA from more than one virus. Varicella-zoster virus DNA was detected in 13
patients (15 eyes). Median age was 57 years. Herpes simplex virus type 1 DNA was
detected in seven patients (seven eyes). Median age was 47 years. Six of these
patients had a history of herpes simplex virus encephalitis. Herpes simplex virus
type 2 DNA was detected in six patients (six eyes). Median age was 20 years.
Three of these patients had a likely history of meningitis. Cytomegalovirus DNA
was detected in one patient who was immunosuppressed iatrogenically. No viral DNA
was detected in one patient from whom a sample was taken after 6 weeks of
acyclovir therapy. CONCLUSIONS: The data suggest that varicella-zoster virus or
herpes simplex virus type 1 cause acute retinal necrosis syndrome in patients
older than 25 years, whereas herpes simplex virus type 2 causes acute retinal
necrosis in patients younger than 25 years. A history of central nervous system
infection in a patient with acute retinal necrosis syndrome suggests that herpes
simplex virus is likely to be the viral cause.
PMID- 10682969
TI - Association of HLA with Vogt-Koyanagi-Harada syndrome in Koreans.
AB - PURPOSE: To study the distribution of human leukocyte antigen HLA-A/B antigens
and HLA-DR/-DQ/-DP alleles and to investigate the immunogenetic background of
Korean patients with Vogt-Koyanagi-Harada (VKH) syndrome and clinical course with
different types of HLA. METHODS: Human leukocyte antigen typings were performed
in 18 Korean patients with VKH syndrome and in 128 healthy control subjects. HLA
A/B loci serologic typing was performed according to the standard
microlymphocytotoxicity technique. DNA was extracted through the salting out
method, and HLA-DR phenotyping and HLA-DR4, HLA-DQ, and HLA-DP subtyping were
performed with the polymerase chain reaction-sequence specific oligonucleotide
probe (PCR-SSOP) method. RESULTS: Among HLA-A/B antigens typed by the standard
microlymphocytotoxicity method, the frequencies of HLA-A31 (RR = 6.1, P<1x10(-2))
and HLA-B55 (RR = 15.8, P<.05) were significantly increased in the patient group
compared with the control group. Among HLA-DR/-DQ/-DP alleles subtyped by DNA
methods, the frequencies of HLA-DRB1*04 (RR = 45.1, P<1x10(-7)) and HLA-DRB1*07
(RR = 3.2, P<.05) were significantly increased. However, significant decreases in
HLA-DRB1*08 (RR = .1, P<.05), HLA-DRB1*13 (RR = .1, P<.05), and HLA-DRB1*14 (RR =
.1, P<.05) frequencies were observed. The result of HLA-DR, HLA-DQ, and HLA-DP
subtyping showed the significant increase in DRB1*0405 (RR = 45.1, P<1x10(-7)),
DQA1*0302 (RR = 12.0, P<1x10(-4)), DQB1*0303 (RR = 5.0, P<1x10(-2)), DQB1*0401
(RR = 18.9, P<1x 10-6), and DPB1*0501 (RR = 3.8, P<.05). However, significant
decreases in DQA1*0101 (RR = .1, P< .05), DQA10102 (RR = .1, P<1x10(-2)),
DQA1*0103 (RR = .1, P<.05), DQA1*0501 (RR = .1, P<1x10(-2)), DQB1*0301 (RR = .1,
P<.05), DQB1*0601 (RR = .1, P<.05), DPB1*0201 (RR = .3, P<.05), and DPB1*0401 (RR
= .1, P<.05) frequencies were also observed. In patients with DRB1*0405 itself or
HLA-DRB1*0405-DQA1*0302-DQB1*0401 haplotype, a reduction in visual acuity and
ocular complications was common. CONCLUSIONS: These results suggest that HLA
DRB1*0405 itself or HLA-DRB1*0405-DQA1*0302-DQB1*0401 haplotype is greatly
increased and may play the most important role in the development and the
clinical course of VKH syndrome in Korean patients.
PMID- 10682970
TI - One-year outcomes of panretinal photocoagulation in proliferative diabetic
retinopathy.
AB - PURPOSE: To describe the clinical features and complications of diabetic
retinopathy, visual acuity, and number of repeat treatments after panretinal
photocoagulation for proliferative diabetic retinopathy in a tertiary care
center. METHODS: A cohort study was conducted with data collection from medical
records of patients undergoing panretinal photocoagulation between 1985 and 1995
at the Scheie Eye Institute; 297 eyes of 186 patients were eligible for study.
RESULTS: The presence of neovascularization of the disk at baseline, an earlier
onset of diabetes, and a shorter duration of disease before panretinal
photocoagulation were the strongest risk factors for needing an additional
panretinal photocoagulation treatment. Sixty-two percent of eyes with poor visual
acuity (< or =20/200) at baseline still had poor visual acuity at 1 year, and 76%
with good visual acuity (> or =20/40) at baseline maintained good visual acuity
at 1 year. Poor vision at baseline was the only risk factor for having poor
vision at 1 year. Vitreous hemorrhage was present in 44% of eyes at baseline. New
vitreous hemorrhage developed in 37% of eyes during the first year after
panretinal photocoagulation. A traction retinal detachment was present in 4% of
eyes at baseline and newly developed in 6% of eyes during follow-up. A repeat
panretinal photocoagulation treatment was performed in 39% of eyes after initial
treatment. A vitrectomy was performed in 10% of eyes from baseline through the 1
year follow-up visit. CONCLUSIONS: The data from this study are useful for
counseling patients with respect to likely visual outcome, possibility of major
complications from proliferative diabetic retinopathy, and the chance of
undergoing additional laser treatment after panretinal photocoagulation.
PMID- 10682971
TI - Optical coherence tomography of the neurosensory retina in rhegmatogenous retinal
detachment.
AB - PURPOSE: To clarify the pathologic changes of the detached neurosensory retina in
rhegmatogenous retinal detachment. METHODS: Retinal images were prospectively
examined by optical coherence tomography in 25 eyes of 25 consecutive patients
with rhegmatogenous retinal detachment. We excluded the patients whose retinal
detachment did not involve the central fovea or patients with poor fixation
during optical coherence tomography (OCT) examination. Optical coherence
tomography was scanned through the center of the fovea. The patients ranged in
age from 15 to 77 years (mean, 45 years; SD, 20 years). The period from onset of
subjective symptoms of retinal detachment to OCT ranged from 2 to 60 days (mean,
16 days; SD, 18 days). Optical coherence tomography findings, best-corrected
visual acuity, and the height of the retinal detachment at the central fovea were
statistically analyzed using ANCOVA (analysis of covariance) and the Mann-Whitney
U test. RESULTS: In 25 eyes of 25 patients, OCT of the detached neurosensory
retina at and adjacent to the center of the fovea demonstrated normal retinal
structure (10 eyes, 40%), intraretinal separation (7 eyes, 28%), and an undulated
separated outer retina (8 eyes, 32%). Three statistically significant factors
affected best-corrected visual acuity: intraretinal separation (P = .001),
intraretinal separation with undulated outer retina (P = .001), and height of
retinal detachment at the central fovea (P<.001). Best-corrected visual acuity
was significantly worse in the 15 eyes with intraretinal separation with or
without an undulated outer retina than in the 10 eyes with retinal thickening but
no intraretinal separation (P = .036). The eight eyes with undulated separated
outer retina showed significantly higher retinal detachment at the central fovea
than the seven eyes with intraretinal separation but no undulated outer retina (P
= .009) and the 10 eyes without intraretinal separation (P = .016). The duration
from onset of subjective symptoms to OCT was not related to the occurrence of
intraretinal separation of the detached retina. CONCLUSIONS: Intraretinal
separation of the detached retina occurred frequently and shortly after retinal
detachment in rhegmatogenous retinal detachment and was one of the factors
associated with poor vision in rhegmatogenous retinal detachment. Best-corrected
visual acuity significantly decreased in the highly detached retina.
PMID- 10682972
TI - Remodeling of choroidal venous drainage after vortex vein occlusion following
scleral buckling for retinal detachment.
AB - PURPOSE: To evaluate the choroidal drainage route after scleral buckling for
retinal detachment. METHODS: We performed wide-angle indocyanine green
angiography with a scanning laser ophthalmoscope in 22 eyes of 22 patients with
rhegmatogenous retinal detachment that had been treated with scleral buckling and
cryopexy. The 22 eyes had at least one retinal break located posterior to the
equator where vortex veins were present. The period between angiography and
retinal detachment surgery was less than 3 months in 10 eyes, 3 to 12 months in
five eyes, and more than 1 year in seven eyes. RESULTS: At the site of the
silicone exoplant and cryopexy for retinal breaks, one vortex vein was occluded
in seven eyes and two in five eyes. Choroidal veins were congested in the
quadrant of the occluded vortex vein in two of 12 eyes that had angiography less
than 3 months after retinal detachment surgery. In 10 of 12 eyes that had
angiography 3 months or more after retinal detachment surgery, new drainage
routes developed that connected the sector of the occluded vortex veins to that
of the intact vortex veins with venovenous anastomoses. No venous congestion was
found in the areas of the occluded vortex veins in the 10 eyes. Venous
collaterals formed between the superior and inferior vortex in all 10 eyes and
between the temporal and nasal vortex in two eyes. CONCLUSIONS: New venous
drainage routes, which were connected to the intact vortex veins, formed in eyes
with occluded vortex veins resulting from scleral buckling surgery and
compensated for choroidal venous congestion. The choroidal veins have a great
deal of plasticity that enables remodeling of the drainage routes, depending on
the pressure gradient.
PMID- 10682973
TI - Intraoperative echographic localization of iodine-125 episcleral plaque for
brachytherapy of choroidal melanoma.
AB - PURPOSE: To report intraoperative echographic localization of iodine-125
episcleral plaque for brachytherapy of choroidal melanoma. METHODS: In a
retrospective study, 117 eyes with medium-sized choroidal melanoma in 117
patients not participating in the Collaborative Ocular Melanoma Study underwent
iodine-125 episcleral plaque radiotherapy with intraoperative echographic
verification of plaque placement between January 1992 and December 1998 at the
Bascom Palmer Eye Institute. RESULTS: After initial plaque placement using
standard localization techniques, intraoperative echography demonstrated
satisfactory tumor-plaque apposition in 76% of eyes (89 of 117). In the 28 eyes
(28 of 117, 24%) that required repositioning of the plaque, the extent of
misplacement was less than 1 mm in 10 eyes, 1.1 to 3.0 mm in six eyes, and
greater than 3 mm in eight eyes. Two eyes had tilting of the plaque, and in two
additional eyes, although the plaque covered all tumor margins, the centration
was considered suboptimal. Repositioning was necessary in 1 eye with an
anteriorly located tumor (1 of 13, 7.7%) and in 20 eyes with peripapillary or
posterior pole tumors (20 of 67, 26.3%). Anteriorly located tumors required
plaque repositioning significantly less frequently than did posteriorly located
tumors (P = .041). Misalignment involved one tumor margin in 23 eyes and two
margins in five eyes. The most commonly misaligned margins were the lateral (35%)
and posterior margins (26%). In no case was an anterior marginal misalignment
documented. At a mean follow-up of 37 months, no tumor-related death or
metastatic disease was noted. Two of the 117 patients (1.7%) had local tumor
recurrence and underwent enucleation. CONCLUSIONS: Intraoperative echography is
an effective adjunct for localization and confirmation of tumor-plaque
relationship. This technique facilitates the identification and correction of
suboptimal plaque placement at the time of surgery, potentially minimizing
treatment failures.
PMID- 10682974
TI - Location, substructure, and composition of basal laminar drusen compared with
drusen associated with aging and age-related macular degeneration.
AB - PURPOSE: To determine whether basal laminar drusen differ in their location,
ultrastructure, or composition from drusen associated with aging and age-related
macular degeneration. METHODS: A paraffin-embedded block from an eye of a patient
with basal laminar drusen was obtained. Sections were examined
immunohistochemically using a battery of antibodies and lectins directed against
drusen-associated proteins and glycoconjugates, respectively. Thin sections were
examined by electron microscopy and compared with eyes with age-related macular
degeneration. RESULTS: Drusen in the eye with basal laminar drusen are located
between the basal lamina of the retinal pigment epithelium and the inner
collagenous layer of Bruch membrane, just as they are in age-related macular
degeneration. Two distinct ultrastructural phenotypes are observed in the eye
with basal laminar drusen; their substructure is indistinguishable from drusen
phenotypes in age-related macular degeneration. Both basal laminar drusen and
drusen associated with age-related macular degeneration are bound by the lectins
Ricinis communis agglutinin and Arachis hypogea agglutinin (after neuraminidase
digestion) and by antivitronectin, anti-HLA-DR, anti-serum amyloid P, and anti-C5
antibodies, but not by antibodies directed against basement membrane-associated
heparan sulfate proteoglycan, laminin, fibrinogen, or collagen type IV.
CONCLUSIONS: These data support the notion that cuticular or basal laminar drusen
are similar to, and perhaps indistinguishable from, drusen associated with age
related macular degeneration and are not nodular or diffuse thickenings of Bruch
membrane, as previously suggested. Thus, we suggest basal laminar drusen is a
misnomer. This clinical phenotype should be identified as "early adult onset,
grouped drusen" or by the eponym "Gass syndrome." Features of basal laminar
drusen, such as uniform drusen size, clustered distribution, and angiographic
features, do not appear to be related to differences in drusen location,
composition, or substructure.
PMID- 10682975
TI - Abnormalities in rod photoreceptors, amacrine cells, and horizontal cells in
human retinas with retinitis pigmentosa.
AB - PURPOSE: To evaluate changes in the rods and amacrine cells and horizontal cells
in human retinas with retinitis pigmentosa. METHODS: Seven retinas from patient
donors with retinitis pigmentosa and 14 age- and postmortem-matched normal human
retinas were processed for immunocytochemistry and confocal microscopy. The
following cell-specific antibodies were used: anti-rhodopsin (rods), anti-gamma
aminobutyric acid (amacrine cells), anticalbindin (cones and horizontal cells),
anti-glial fibrillary acidic protein (astrocytes and reactive Muller cells), and
anti-synaptophysin and anti-SV2 (synaptic vesicles). RESULTS: In retinal regions
with significant photoreceptor loss, the rods, gamma-aminobutyric acid-positive
amacrine cells, and calbindin-positive horizontal cells had undergone neurite
sprouting. The rod, amacrine and horizontal cell neurites were associated with
the surfaces of glial fibrillary acidic protein-immunoreactive Muller cells. Most
rod neurites that projected into the inner retina contacted the somata of gamma
aminobutyric acid-positive amacrine cells. CONCLUSIONS: Rods, amacrine and
horizontal cells undergo neurite sprouting in human retinas with retinitis
pigmentosa. These changes in the retinal neurons may contribute to the
electroretinographic abnormalities and progressive decline in vision noted by
patients with retinitis pigmentosa. These alterations may also complicate
strategies for treatment of retinitis pigmentosa.
PMID- 10682976
TI - Retinal micromovements, the visual line, and Donders' law.
AB - PURPOSE: To report the relationship of the retinal micromovements to the visual
line and to confirm the validity of Donders' Law. METHODS: Two video cameras
suspended from a headband were used to record eye (video-oculography) and head
movements. Eye positions in held gaze and following various trajectories to a
target were recorded in five normal, young subjects. The videotapes were analyzed
off-line using a computer algorithm. RESULTS: Retinal micromovements cause the
visual line to trace a zigzag pathway across the foveola, which has an
approximate diameter of 350 microm (about 2 degrees). The mean micromovement was
about 10 microm in 33.3 msec. The cumulative effect of successive micromovements
may move the visual line across the foveola from edge to edge depending on the
elapsed time. When the visual line reaches the edge of the foveola it changes its
direction. When the eye resets to the same target by different trajectories, the
visual line may alight up to about 350 microm from its original location anywhere
within the foveola. CONCLUSIONS: Donders' Law is upheld because for each
direction of gaze, and regardless of the trajectory used to reach that direction
of gaze, the retina has a constant orientation to an index head plane at any
given moment in time. Failure to consider that the micromovements cause a shift
in the position of the visual line within the foveola may account for the
exceptions to Donders' Law found by contemporary researchers using invasive
recording techniques.
PMID- 10682977
TI - The human leukocyte antigen complex and chronic ocular inflammatory disorders.
AB - PURPOSE: To review the role of gene products from the human leukocyte antigen
(HLA) complex in the normal functioning of the immune system, ocular
inflammation, and models of autoimmunity. METHOD: A review of recently published
reports. RESULTS: Many chronic ocular inflammatory diseases are associated with
specific alleles of the HLA complex. Understanding how HLA gene products function
normally provides clues to the mechanism of disease associations. In the thymus,
these molecules control the shape of the developing T-cell repertoire, leading to
self-tolerance. In the periphery, HLA molecules bind and present peptide
fragments to T cells, leading to a variety of effector functions. Although
effector functions are for the most part beneficial, models are reviewed in which
peptide-HLA interactions lead to T-cell responses with pathologic consequences.
Herpes stromal keratitis is an informative animal model highlighting the role of
self-tolerance, infection, and molecular mimicry in the development of
autoimmunity. CONCLUSIONS: Human leukocyte antigen gene products may be
associated with chronic inflammatory disorders through the unique presentation of
"disease-inducing" peptides or the development of a T-cell repertoire prone to
autoreactivity and molecular mimicry.
PMID- 10682978
TI - Conjunctival incision for primary conjunctivodacryocystorhinostomy with Jones
tube.
AB - PURPOSE: To study a conjunctival incision approach for primary
conjunctivodacryocystorhinostomy with Jones tube insertion. METHODS: This
technique was applied throughout an 8-year period on 13 adult patients; each
presented with complete lacrimal obstruction at the common canaliculus and
excessive tearing. RESULTS: Surgical outcome was successful, with no external
facial scarring. Follow-up ranged from 9 months to 7 years (median, 4.5 years).
Complications included a tube exchange in one patient and occasional tearing in
another. CONCLUSION: A conjunctival incision approach to
conjunctivodacryocystorhinostomy (CDCR) with Jones tube insertion is an
alternative technique for adult patients, especially those known (or potential)
keloid-former cases, or those preferring not to undergo laser treatment and
wanting to avoid an external facial scar.
PMID- 10682979
TI - Primary localized conjunctival amyloidosis presenting with recurrence of
subconjunctival hemorrhage.
AB - PURPOSE: To report the ocular presentation and histopathology of a patient with
primary localized conjunctival amyloidosis. METHODS: A 38-year-old woman
presented with a recurrence of episodes of severe bilateral subconjunctival
hemorrhage. Ocular examination revealed yellowish, marked folding and redundancy
of the conjunctiva in the inferior cul-de-sac of each eye. RESULTS: After two
initial conjunctival biopsies that showed only chronic inflammation, a third
biopsy revealed the presence of amyloid in the substantia propria of the
conjunctiva. CONCLUSION: Primary localized conjunctival amyloidosis is rare and
usually diagnosed histologically instead of clinically. Recurrence of
subconjunctival hemorrhage may be the initial presentation. Evaluation for
systemic diseases is advised, though the results of the examination are almost
always negative.
PMID- 10682980
TI - Localized infection by Serratia marcescens simulating a conjunctival neoplasm.
AB - PURPOSE: To report a Serratia marcescens infection that clinically simulated a
conjunctival neoplasm. METHOD: Case report. RESULTS: A healthy 80-year-old man
without contact lenses presented with a pink-yellow conjunctival mass that
resembled a solid neoplasm. Stains and cultures of material that exuded from the
mass during surgery revealed S. marcescens. Histopathology disclosed an
epithelial-lined cyst with macrophages containing S. marcescens. CONCLUSION:
Although S. marcescens usually affects the eye as a keratoconjunctivitis in
patients with contact lenses, it can also present as a mass simulating a neoplasm
in a patient who does not wear contact lenses.
PMID- 10682981
TI - A new mutation (A546T) of the betaig-h3 gene responsible for a French lattice
corneal dystrophy type IIIA.
AB - PURPOSE: To characterize the betaig-h3 gene defect in a French family affected
with lattice corneal dystrophy type IIIA (LCDIIIA). METHODS: Histologic
examination was performed from corneal buttons of two patients. Genomic DNA was
extracted from leukocytes, and exons of the betaig-h3 gene were amplified by
polymerase chain reaction to be directly sequenced. RESULTS: Numerous deposits
were evident in the stroma and beneath the Bowman membrane, which had all the
features of amyloid deposits. Analysis of exon 12 revealed a heterozygous G to A
transition on codon 546. CONCLUSION: In contrast to Japanese patients, these
French patients affected with LCDIIIA carry a distinct mutation of the betaig-h3
gene (A546T instead of P501T). Therefore, it is unclear whether different
mutations could result in the same dystrophy or whether we are dealing with
clinical heterogeneity of LCDIIIA.
PMID- 10682982
TI - Intracorneal hematoma in Mooren ulceration.
AB - PURPOSE: To report a case of intracorneal hematoma occurring in association with
Mooren ulceration. METHOD: Case report. RESULTS: In an 81-year-old man with
bilateral Mooren ulceration, a dense intracorneal hemorrhage occurred in the
right eye secondary to peripheral corneal neovascularization and was followed by
slow resolution over a 3-year period. Following subsequent lamellar and
penetrating keratoplasty, histopathologic examination demonstrated the
association between the stromal neovascularization and the residual interlamellar
hemorrhage, as well as phagocytosis of residual hemosiderin by macrophages.
CONCLUSION: Intracorneal hematoma with spontaneous resolution has been documented
clinically and histopathologically in an eye with Mooren ulceration.
PMID- 10682983
TI - Choroidal effusions and hypotony caused by severe anterior lens capsule
contraction after cataract surgery.
AB - PURPOSE: To report the clinical features and management of two patients with
pseudophakic anterior capsule contraction with secondary tractional ciliary body
detachments and hypotonous choroidal effusions. METHODS: Case reports. RESULTS:
In two eyes of two patients with pseudophakia, severe anterior lens capsule
contraction and tractional ciliary body detachments, anterior capsulotomy (one
Nd:YAG laser, one surgical), was followed by resolution of the ocular hypotony
and resolution/nonrecurrence of the choroidal effusions. In both cases,
continuous curvilinear capsulorhexis was used during cataract surgery.
CONCLUSION: Anterior capsule contraction following pseudophakia may result in
tractional ciliary detachment and secondary ocular hypotony. Radial anterior
capsulotomy appeared to be effective in both cases.
PMID- 10682984
TI - Syndrome simulating pseudotumor cerebri caused by partial transverse venous sinus
obstruction in metastatic prostate cancer.
AB - PURPOSE: To report a case of partial transverse venous sinus obstruction causing
a syndrome resembling pseudotumor cerebri. METHOD: Case report. A 61-year-old man
developed decreased vision, bilateral papilledema, and a highly increased
cerebrospinal fluid opening pressure. Brain magnetic resonance imaging (MRI)
disclosed a small, extra-axial mass near the torcula, which was dismissed as an
incidental meningioma because cerebral angiography showed sinus patency. RESULTS:
The patient's vision worsened. Biopsy of the enlarging mass disclosed metastatic
prostate cancer. After radiation therapy, the mass shrank, magnetic resonance
angiography disclosed reopening of the transverse sinuses, and papilledema
resolved, but visual fields remained severely compromised. CONCLUSION: Partial
blockage of the dural venous sinus by a small mass near the torcula can cause a
sufficient increase in intracranial pressure to produce vision-threatening
papilledema.
PMID- 10682985
TI - Bilateral blindness as the initial presentation of lymphoma of the sphenoid
sinus.
AB - PURPOSE: To report a patient with large-cell lymphoma of the sphenoid sinus
presenting with bilateral blindness and no other signs or symptoms. METHOD: Case
report. A previously healthy 5-year-old boy complained of sudden vision loss
without other systemic complaints. RESULTS: Ophthalmologic examination revealed
no light perception bilaterally. The pupils of the patient were fixed at 8 mm
without reaction to the brightest light stimulus. Systemic examination was
unremarkable, and neuroimaging revealed a large sphenoid tumor extending
intracranially. Biopsy of the tumor proved to be large-cell lymphoma. CONCLUSION:
Large-cell lymphoma affecting children may present initially with blindness,
without other systemic symptoms.
PMID- 10682986
TI - DNA-based diagnosis of the von Hippel-Lindau syndrome.
AB - PURPOSE: To evaluate the etiology of a unilateral hemangioblastoma noted in a
male with a family history remarkable only for spine surgery in the proband's
father. METHODS: Genomic DNA was isolated from peripheral blood of family
members, and the three exons of the von Hippel-Lindau gene were examined for
mutations by direct sequencing. RESULTS: A three base pair (bp) deletion in exon
1 of the VHL gene was found in the father and both sons. This in-frame deletion
results in the loss of a phenylalanine residue from the von Hippel-Lindau protein
product, at amino acid position 76. CONCLUSION: Genetic screening has confirmed
that von Hippel-Lindau syndrome is responsible for the hemangioblastoma in the
proband. Magnetic resonance imaging scans performed as a consequence of these
results indicated spinal tumors present in the father and tumors present in the
cerebellum of the proband's sibling. As close, lifelong follow-up is warranted
with this disease, this case demonstrates the value of DNA testing in patients
with ocular findings consistent with von Hippel-Lindau disease in the absence of
a recognized family history.
PMID- 10682987
TI - A novel spontaneous missense mutation in VMD2 gene is a cause of a best macular
dystrophy sporadic case.
AB - PURPOSE: To report the molecular characterization of a novel VMD2 mutation
causing a Best macular dystrophy sporadic case. METHODS: All family members
underwent ophthalmologic examination and genetic testing by single strand
conformation polymorphism analysis and direct sequencing of the VMD2 gene.
RESULTS: A single T to G transition at nucleotide 663 was identified in one of
the VMD2 gene copies of the patient, which results in a Cys to Trp substitution
at position 221 in the corresponding protein (C221W). Sequence analysis of the
VMD2 exon 6 of both parents of the patient did not reveal any mutation.
CONCLUSION: These data confirm the involvement of the VMD2 gene in Best macular
dystrophy onset, even in sporadic cases of the disease, pointing out the
relevance of molecular analysis in the diagnosis of this degenerative retinal
disease.
PMID- 10682988
TI - Serous retinal detachment at the macula in sarcoidosis.
AB - PURPOSE: To report an unusual case of serous retinal detachment at the macula in
a patient with a history of sarcoidosis. METHOD: Case report. In a 44-year-old
Caucasian man, the history, clinical features, fluorescein angiography,
laboratory and radiological investigations, treatment, and lung autopsy findings
are presented. RESULTS: A serous detachment of the retina in the macula of his
left eye was observed. He had pulmonary hypertension secondary to active sarcoid
granulomas that caused pulmonary angiitis. CONCLUSION: Serous retinal detachment
at the macula may occur in association with pulmonary angiitis secondary to
sarcoidosis.
PMID- 10682989
TI - Optical cross-sectional observation of resolved diabetic macular edema associated
with vitreomacular separation.
AB - PURPOSE: To describe the resolution of cystoid macular edema associated with
vitreomacular separation in a diabetic patient. METHODS: Case report. A 58-year
old man who had cataract surgery 3 years earlier developed diabetic macular edema
after panretinal laser photocoagulation. For a detailed fundus examination, we
performed neodymium: YAG (Nd:YAG) laser capsulotomy in the left eye as the
initial management. RESULTS: Two days after the laser capsulotomy, fundus
biomicroscopy and B-mode ultrasonography disclosed a vitreomacular separation in
the left eye that was not detectable preoperatively. Optical coherence tomography
through the macula disclosed a dramatic decrease in the size of intraretinal
cystoid spaces with an improvement of visual acuity. Scanning retinal thickness
analysis also confirmed the decrease of retinal thickness at the macula with the
resolution of cystoid macular edema. CONCLUSION: Resolution of diabetic macular
edema with subsequent visual recovery is potentially associated with the
vitreomacular separation in a patient after Nd:YAG laser capsulotomy.
PMID- 10682990
TI - Reduced expression of the adherens junction protein cadherin-5 in a diabetic
retina.
AB - PURPOSE: Transvascular leakage occurs in diabetic retinopathy. The tight junction
proteins occludin and zonula occludens-1 (ZO-1) and adherens junction protein
cadherin-5 are critical to the maintenance of endothelial barrier. We report a
comparison of junction protein expression in the normal and diabetic retina.
METHOD: Case report. Postmortem retinal cryosections were prepared from the left
eye of a 73-year-old woman with diabetic retinopathy. Cryosections were
immunostained for cadherin-5, occludin, and ZO-1 and compared with retinal
cryosections from the right eye of a 72-year-old man with no progression of
retinal disease. RESULTS: Immunofluorescence showed positive retinal vessel
staining for occludin and ZO-1 in both eyes and cadherin-5 in the normal eye but
reduced cadherin-5 staining in the retinal vessels of the diabetic eye.
CONCLUSION: Increases in transvascular leakage observed in diabetic retinal
vasculature may be associated with reduction in the expression of the critical
adherens junction protein, cadherin-5.
PMID- 10682991
TI - Retinal vasculitis occurring with common variable immunodeficiency syndrome.
AB - PURPOSE: To report severe retinal vasculitis causing decreased vision in three
patients with the common variable immunodeficiency syndrome. METHOD: Case report.
Three patients with common variable immunodeficiency syndrome developed decreased
vision secondary to retinal vasculitis. Fluorescein angiography was performed in
all three patients. Peribulbar injections were given in one patient, and two
patients were treated with oral steroids and cyclosporin. RESULTS: All three
patients were young and had classic common variable immunodeficiency syndrome.
Bilateral retinal vasculitis and diffuse retinal edema were present in all three
patients, and two patients had retinal neovascularization in the absence of
ischemia. No evidence of intraocular infection was present, and none was detected
systematically. Visual acuity decreased in five of the six eyes and was
responsive to treatment in only one patient (both eyes). CONCLUSION: Retinal
vasculitis may be another autoimmune manifestation of common variable
immunodeficiency syndrome.
PMID- 10682992
TI - Latanoprost increases the severity and recurrence of herpetic keratitis in the
rabbit; latanoprost and herpes simplex keratitis.
PMID- 10682993
TI - Epidemic and pandemic 'flu.
PMID- 10682994
TI - Benefits of irradiation for DCIS: a Pyrrhic victory.
PMID- 10682995
TI - Endpoints for homocysteine-lowering trials.
PMID- 10682996
TI - Serum homocysteine and risk of coronary heart disease in UK Indian Asians.
PMID- 10682997
TI - Neonatal screening for hearing impairment.
PMID- 10682998
TI - Double gloving--electrical resistance and surgeons' resistance.
PMID- 10682999
TI - Value of 6-min-walk test for assessment of severity and prognosis of heart
failure.
PMID- 10683000
TI - Effect of homocysteine-lowering treatment with folic acid plus vitamin B6 on
progression of subclinical atherosclerosis: a randomised, placebo-controlled
trial.
AB - BACKGROUND: A high plasma homocysteine concentration is associated with increased
risk of atherothrombotic disease. We investigated the effects of homocysteine
lowering treatment (folic acid plus vitamin B6) on markers of subclinical
atherosclerosis among healthy siblings of patients with premature
atherothrombotic disease. METHODS: We did a randomised, placebo-controlled trial
among 158 healthy siblings of 167 patients with premature atherothrombotic
disease. 80 were assigned placebo and 78 were assigned 5 mg folic acid and 250 mg
vitamin B6 daily for 2 years. The primary endpoint was the development or
progression of subclinical atherosclerosis as estimated from exercise
electrocardiography, the ankle-brachial pressure index, and carotid and femoral
ultrasonography. FINDINGS: Ten participants in the treatment group, and 14 in the
placebo group dropped out. Vitamin treatment, compared with placebo, was
associated with a decrease in fasting homocysteine concentration (from 14.7 to
7.4 micromol/L vs from 14.7 to 12.0 micromol/L), and in postmethionine
homocysteine concentration (from 64.9 to 34.9 micromol/L vs from 64.8 to 50.3
micromol/L). It was also associated with a decreased rate of abnormal exercise
electrocardiography tests (odds ratio 0.40 [0.17-0.93]; p=0.035). There was no
apparent effect of vitamin treatment on ankle-brachial pressure indices (0.87
[0.56-1.33]), or on carotid and peripheral-arterial outcome variables (1.02 [0.26
4.05] and 0.86 [0.47-1.59], respectively). INTERPRETATION: Homocysteine-lowering
treatment with folic acid plus vitamin B6 in healthy siblings of patients with
premature atherothrombotic disease is associated with a decreased occurrence of
abnormal exercise electrocardiography tests, which is consistent with a decreased
risk of atherosclerotic coronary events.
PMID- 10683001
TI - Plasma homocysteine concentrations and risk of coronary heart disease in UK
Indian Asian and European men.
AB - BACKGROUND: Reasons for the increase in mortality due to coronary heart disease
(CHD) in UK Indian Asians are not well understood. In this study, we tested the
hypotheses that elevated plasma homocysteine concentrations are a risk factor for
CHD in Indian Asians, and explain part of their increased CHD risk, compared with
Europeans. METHODS: We undertook two parallel case-control studies, one in
Europeans and one in Indian Asians. We recruited 551 male cases (294 European,
257 Indian Asian) and 1025 healthy male controls (507 European, 518 Indian
Asian). Fasting and post-methionine load homocysteine, vitamin B12 and folate
concentrations, and conventional CHD risk factors were measured. FINDINGS:
Fasting homocysteine concentrations were 8% higher (95% CI 3-14) in cases
compared with controls, in both ethnic groups. The odds ratio of CHD for a 5
micromol/L increment in fasting plasma homocysteine was 1.3 (1.1-1.6) in
Europeans and 1.2 (1.0-1.4) in Indian Asians. The association between fasting
plasma homocysteine and CHD was independent of conventional CHD risk factors in
both ethnic groups. Post-load homocysteine concentrations were not significantly
different in cases compared with controls. Among the controls, fasting
homocysteine concentrations were 6% (2-10) higher in Indian Asians than in
Europeans. From the results we estimate that elevated homocysteine may contribute
to twice as many CHD deaths in Indian Asians, compared with Europeans. The
differences in homocysteine concentrations between the two ethnic groups were
explained by lower vitamin B12 and folate levels in Asians. INTERPRETATION:
Plasma homocysteine is a novel and independent risk factor for CHD in Indian
Asians, and may contribute to their increased CHD risk. Raised homocysteine
concentrations in Indian Asians may be related to their reduced vitamin B12 and
folate levels, implying that the increased CHD risk in this group may be reduced
by dietary vitamin supplementation.
PMID- 10683002
TI - Radiotherapy in breast-conserving treatment for ductal carcinoma in situ: first
results of the EORTC randomised phase III trial 10853. EORTC Breast Cancer
Cooperative Group and EORTC Radiotherapy Group.
AB - BACKGROUND: Ductal carcinoma in situ (DCIS) of the breast is a disorder that has
become more common since it may manifest as microcalcifications that can be
detected by screening mammography. Since selected women with invasive cancer can
be treated safely with breast conservation therapy it is paradoxical that total
mastectomy has remained the standard treatment for DCIS. We did a randomised
phase III clinical trial to investigate the role of radiotherapy after complete
local excision of DCIS. METHODS: Between 1986 and 1996, women with clinically or
mammographically detected DCIS measuring less than or equal to 5 cm were treated
by complete local excision of the lesion and then randomly assigned to either no
further treatment (n=503) or to radiotherapy (n=507; 50 Gy in 5 weeks to the
whole breast). The median duration of follow-up was 4.25 years (maximum 12.0
years). All analyses were by intention to treat. FINDINGS: 500 patients were
followed up in the no further treatment group and 502 in the radiotherapy group.
In the no further treatment group 83 women had local recurrence (44 recurrences
of DCIS, and 40 invasive breast cancer). In the radiotherapy group 53 women had
local recurrences (29 recurrences of DCIS, and 24 invasive breast cancer). The 4
year local relapse-free was 84% in the group treated with local excision alone
compared with 91% in the women treated by local excision plus radiotherapy (log
rank p=0.005; hazard ratio 0.62). Similar reductions in the risk of invasive
(40%, p=0.04) and non-invasive (35%, p=0.06) local recurrence were seen.
CONCLUSIONS: Radiotherapy after local excision for DCIS, as compared with local
excision alone, reduced the overall number of both invasive and non-invasive
recurrences in the ipsilateral breast at a median follow-up of 4.25 years.
PMID- 10683003
TI - Stress and psychiatric disorder in healthcare professionals and hospital staff.
AB - BACKGROUND: Previous studies of stress in healthcare staff have indicated a
probable high prevalence of distress. Whether this distress can be attributed to
the stressful nature of the work situation is not clear. No previous study has
used a detailed interview method to ascertain the link between stress in and
outside of work and anxiety and depressive disorders. METHODS: Doctors, nurses,
and administrative and ancillary staff were screened using the general health
questionnaire (GHQ). High scorers (GHQ>4) and matched individuals with low GHQ
scores were interviewed by means of the clinical interview schedule to ascertain
definite anxiety and depressive disorders (cases). Cases and controls, matched
for age, sex, and occupational group were interviewed with the life events and
difficulties schedule classification and an objective measure of work stress to
find out the amount of stress at work and outside of work. Sociodemographic and
stress variables were entered into a logistic-regression analysis to find out the
variables associated with anxiety and depressive disorders. FINDINGS: 64 cases
and 64 controls were matched. Cases and controls did not differ on demographic
variables but cases were less likely to have a confidant (odds ratio 0.09 [95% CI
0.01-0.79]) and more likely to have had a previous episode of psychiatric
disorder (3.07 [1.10-8.57]). Cases and controls worked similar hours and had
similar responsibility but cases had a greater number of objective stressful
situations both in and out of work (severe event or substantial difficulty in and
out of work-45 cases vs 18 controls 6.05 [2.81-13.00], p<0.001; severe chronic
difficulty outside of work-27 vs 8, 5.12 [2.09-12.46], p<0.001). Cases had
significantly more objective work problems than controls (median 6 vs 4, z=3.81,
p<0.001). The logistic-regression analyses indicated that even after the effects
of personal vulnerability to psychiatric disorder and ongoing social stress
outside of work had been taken into account, stressful situations at work
contributed to anxiety and depressive disorders. INTERPRETATION: Both stress at
work and outside of work contribute to the anxiety and depressive disorders
experienced by healthcare staff. Our findings suggest that the best way to
decrease the prevalence of these disorders is individual treatment, which may
focus on personal difficulties outside of work, combined with organisational
attempts to reduce work stress. The latter may involve more assistance for staff
who have a conflict between their managerial role and clinical role.
PMID- 10683004
TI - Effects of replicating primary-reflex movements on specific reading difficulties
in children: a randomised, double-blind, controlled trial.
AB - BACKGROUND: Children with specific reading difficulties have problems that extend
beyond the range of underlying language-related deficits (eg, they have
difficulties with balance and motor control). We investigated the role of
persistent primary reflexes (which are closely linked in the earliest months of
life to the balance system) in disrupting the development of reading skills.
METHODS: We assessed the efficacy of an intervention programme based on
replicating the movements generated by the primary-reflex system during fetal and
neonatal life. A randomised, individually matched, double-blind, placebo
controlled design was used and children (aged 8-11 years) with persistent primary
reflexes and a poor standard of reading were enrolled into one of three treatment
groups: experimental (children were given a specific movement sequence); placebo
control (children were given non-specific movements); and control (no movements).
FINDINGS: From an initial sample of 98 children, 60 children, 20 in each group
were matched on age, sex, verbal intelligence quotient (IQ), reading ability, and
persistent asymmetrical tonic neck reflex. For asymmetrical tonic neck-reflex
levels there was a significant (group by time) interaction (p<0.001). The
experimental group showed a significant decrease in the level of persistent
reflex over the course of the study (mean change -1.8 [95% CI -2.4 to -1.2],
p<0.001), whereas the changes in the placebo-control and control groups were not
significant (-0.2 [-0.9 to 0.6] and -0.4 [-0.9 to 0.2]). INTERPRETATION: This
study provides further evidence of a link between reading difficulties and
control of movement in children. In particular, our study highlights how the
educational functioning of children may be linked to interference from an early
neurodevelopmental system (the primary-reflex system). A new approach to the
treatment of children with reading difficulties is proposed involving assessment
of underlying neurological functioning, and appropriate remediation.
PMID- 10683005
TI - Suppression and recovery of adrenal response after short-term, high-dose
glucocorticoid treatment.
AB - BACKGROUND: Suppression of the adrenal response is an unpredictable consequence
of glucocorticoid treatment. To investigate the kinetics of the adrenal response
after short-term, high-dose glucocorticoid treatment, we measured the adrenal
response to the low-dose (1 microg) corticotropin stimulation test. METHODS: We
studied 75 patients who received the equivalent of at least 25 mg prednisone
daily for between 5 days and 30 days. After discontinuation of glucocorticoid
treatment, 1 microg corticotropin was administered intravenously, and stimulated
plasma cortisol concentrations were measured 30 min later. In patients with a
suppressed response to 1 microg corticotropin, the test was repeated until
stimulated plasma cortisol concentrations reached the normal range. FINDINGS: The
adrenal response to 1 microg corticotropin was suppressed in 34 patients and
normal in 41. Subsequent low-dose corticotropin tests showed a steady recovery of
the adrenal response within 14 days. In two patients, the adrenal response
remained suppressed for several months. There was no correlation between plasma
cortisol concentrations and the duration or dose of glucocorticoid treatment.
INTERPRETATION: Suppression of the adrenal response is common after short-term,
high-dose glucocorticoid treatment. The low-dose corticotropin test is a
sensitive and simple test to assess the adrenal response after such treatment.
PMID- 10683006
TI - A woman with ascites and abdominal masses.
PMID- 10683007
TI - Indinavir concentrations and St John's wort.
AB - St John's wort reduced the area under the curve of the HIV-1 protease inhibitor
indinavir by a mean of 57% (SD 19) and decreased the extrapolated 8-h indinavir
trough by 81% (16) in healthy volunteers. A reduction in indinavir exposure of
this magnitude could lead to the development of drug resistance and treatment
failure.
PMID- 10683008
TI - Acute heart transplant rejection due to Saint John's wort.
AB - We report here acute rejection in two transplant patients due to a metabolic
interaction of St John's wort and cyclosporin.
PMID- 10683009
TI - School-based hepatitis B vaccination programme and adolescent multiple sclerosis.
AB - We investigated multiple sclerosis in adolescents in British Columbia before and
after a hepatitis B vaccination programme was begun. There was no evidence of a
link between hepatitis B vaccination and multiple sclerosis or other
demyelinating disease.
PMID- 10683010
TI - Pulse-inversion contrast harmonic imaging: ultrasonographic assessment of
cerebral perfusion.
AB - Pulse-inversion contrast harmonic imaging is a new ultrasonographic technique
that can assess brain perfusion. In an adult with moyamoya disease and multiple
recurrent strokes, this method detected subtle hemispheric differences in
temporal-lobe perfusion, presumably due to neovascularisation, which were not
shown by xenon-computed tomography or magnetic resonance perfusion imaging.
PMID- 10683011
TI - Simian foamy virus infection among zoo keepers.
AB - We investigated 322 North American zoo workers in an anonymous serosurvey for
antibodies to simian foamy viruses to establish the potential risk of zoonotic
transmission by these retroviruses. 4 of 133 (3%) individuals who worked
specifically with mammals including primates were seropositive, primarily with
chimp-like viruses, indicating the importance of work practices to reduce
exposure to these agents.
PMID- 10683012
TI - Suspicions raised over breast-cancer-therapy trial.
PMID- 10683013
TI - Functional foods nibble away at serum cholesterol concentrations.
PMID- 10683014
TI - Experts hear sobering side of HIV-1 treatment story.
PMID- 10683015
TI - Epidemiological studies: overdone or underappreciated?
PMID- 10683016
TI - British American tobacco shrugs off smuggling charges.
PMID- 10683017
TI - New Zealand's pharmaceutical reference-pricing strategy may backfire.
PMID- 10683018
TI - South Africa's AIDS taskforce questioned.
PMID- 10683019
TI - Are booster immunisations needed for lifelong hepatitis B immunity? European
Consensus Group on Hepatitis B Immunity.
AB - Long-term protection against clinically significant breakthrough hepatitis B (HB)
virus infection and chronic carriage depends on immunological memory, which
allows a protective anamnestic antibody response to antigen challenge. Memory
seems to last for at least 15 years in immunocompetent individuals. To date there
are no data to support the need for booster doses of HB vaccine in
immunocompetent individuals who have responded to a primary course. All
adequately vaccinated individuals have shown evidence of immunity in the form of
persisting anti-HBs and/or in vitro B-cell stimulation or an anamnestic response
to a vaccine challenge. Nonetheless several countries and individuals currently
have a policy of administering booster doses to certain risk groups. Boosters may
be used to provide reassurance of protective immunity against benign breakthrough
infection. For immunocompromised patients, regular testing for anti-HBs, and a
booster injection when the titre falls below 10 mIU/mL, is advised. Long-term
monitoring should continue, to confirm the absence of clinically significant
breakthrough episodes of hepatitis B and to find out if a carrier state develops
after 15 years. Also, non-responders to a primary course should continue to be
studied.
PMID- 10683020
TI - Value of drug-licensing documents in studying the effect of postmenopausal
hormone therapy on cardiovascular disease.
AB - BACKGROUND: In a previous study of pooled data from published trials, we found no
evidence to support the claim that postmenopausal hormone therapy (PHT) is
associated with a decrease in cardiovascular disease. The purpose of this study
was to see whether reports of clinical trials attached to drug-licensing
applications in Finland could be obtained for scientific purposes, whether they
are useful for studying cardiovascular events resulting from PHT, and if so,
whether these unpublished reports corroborate the results of published reports.
METHODS: Since clinical trials in drug-licensing documents are confidential, we
had to obtain special permission from the Ministry of Social Affairs and Health
to use the data for research purposes. After permission was granted, we studied
the clinical sections of licensing documents for PHT drugs sent by drug companies
to the Finnish Drug Agency. We aimed to identify trials that compared PHT and a
placebo (or no therapy, or vitamin-mineral drugs), and that reported on
cardiovascular and thromboembolic events or superficial phlebitis. New trials
were identified and their data were pooled with those of published trials.
FINDINGS: 17 licensing applications for drugs used as PHT were found. The number,
type, and quality of reporting of clinical trials varied widely between
applications. The trials and their reporting of unanticipated adverse events were
mostly inadequate. Six new trials (ie, those fulfilling the inclusion criteria
and not included in our earlier report) were found. The new trials added little
to the conclusions of previously published studies: the calculated odds ratios of
cardiovascular and thromboembolic events for women taking PHT versus those not
taking it was 1.97 (95% CI 0.84-4.63), compared with 1.65 (0.65-4.21) in our
previous study. INTERPRETATION: In this case, unpublished trials added only a
little to the data available from published trials, mainly due to the type of
clinical data used in the licensing applications. The new data did not change the
previous conclusion that clinical trials do not support a beneficial effect of
PHT on cardiovascular diseases.
PMID- 10683021
TI - The death of a British officer-cadet from heat illness.
PMID- 10683022
TI - Management of unstable coronary-artery disease.
PMID- 10683023
TI - Management of unstable coronary-artery disease.
PMID- 10683024
TI - Management of unstable coronary-artery disease.
PMID- 10683025
TI - Management of unstable coronary-artery disease.
PMID- 10683026
TI - Nimesulide and neonatal renal failure.
PMID- 10683027
TI - Safety of St John's wort (Hypericum perforatum)
PMID- 10683028
TI - Safety of St John's wort (Hypericum perforatum)
PMID- 10683029
TI - Safety of St John's wort (Hypericum perforatum)
PMID- 10683030
TI - Safety of St John's wort (Hypericum perforatum)
PMID- 10683031
TI - Taxane-induced glaucoma.
PMID- 10683032
TI - Urinary incontinence and the rhabdosphincter.
PMID- 10683033
TI - Hepatitis E virus infection.
PMID- 10683034
TI - Pneumococcal vaccine and the elderly.
PMID- 10683035
TI - End of exile for Taiwan.
PMID- 10683036
TI - Early uptake of research findings after fast-track publication.
PMID- 10683037
TI - Trade agreements and public health: role of WHO.
PMID- 10683038
TI - Judgment by peers.
PMID- 10683039
TI - The Nobel chronicles. 1987: Susumu Tonegawa (b 1939).
PMID- 10683040
TI - Recent advances in wound healing.
PMID- 10683041
TI - IRBs search for answers and support during a time of institutional change.
PMID- 10683042
TI - Music therapists chime in with data on medical results.
PMID- 10683043
TI - From the Centers for Disease Control and Prevention. Achievements in public
health, 1900-1999: changes in the public health system.
PMID- 10683044
TI - Effects of androstenedione in young men.
PMID- 10683045
TI - Effects of androstenedione in young men.
PMID- 10683046
TI - Effects of androstenedione in young men.
PMID- 10683047
TI - Animal research and human disease.
PMID- 10683049
TI - Chronic fatigue: syndrome or disease?
PMID- 10683048
TI - Animal research and human disease.
PMID- 10683050
TI - Alcohol consumption and risk of coronary heart disease.
PMID- 10683051
TI - Immunologic strategies for herpes vaccination.
PMID- 10683052
TI - Immunologic strategies for herpes vaccination.
PMID- 10683053
TI - A controlled trial of a critical pathway for treatment of community-acquired
pneumonia. CAPITAL Study Investigators. Community-Acquired Pneumonia Intervention
Trial Assessing Levofloxacin.
AB - CONTEXT: Large variations exist among hospitals in the use of treatment resources
for community-acquired pneumonia (CAP). Lack of a common approach to the
diagnosis and treatment of CAP has been cited as an explanation for these
variations. OBJECTIVE: To determine if use of a critical pathway improves the
efficiency of treatment for CAP without compromising the well-being of patients.
DESIGN: Multicenter controlled clinical trial with cluster randomization and up
to 6 weeks of follow-up. SETTING: Nineteen teaching and community hospitals in
Canada. PATIENTS: A total of 1743 patients with CAP presenting to the emergency
department at 1 of the participating institutions between January 1 and July 31,
1998. INTERVENTION: Hospitals were assigned to continue conventional management
(n = 10) or implement the critical pathway (n = 9), which consisted of a clinical
prediction rule to guide the admission decision, levofloxacin therapy, and
practice guidelines. MAIN OUTCOME MEASURES: Effectiveness of the critical
pathway, as measured by health-related quality of life on the Short-Form 36
Physical Component Summary (SF-36 PCS) scale at 6 weeks; and resource
utilization, as measured by the number of bed days per patient managed (BDPM).
RESULTS: Quality of life and the occurrence of complications, readmission, and
mortality were not different for the 2 strategies; the 1-sided 95% confidence
limit of the between-group difference in the SF-36 PCS change score was 2.4
points, which was within a predefined 3-point boundary for equivalence. Pathway
use was associated with a 1.7-day reduction in BDPM (4.4 vs 6.1 days; P = .04)
and an 18% decrease in the admission of low-risk patients (31% vs 49%; P = .01).
Although inpatients at critical pathway hospitals had more severe disease, they
required 1.7 fewer days of intravenous therapy (4.6 vs 6.3 days; P = .01) and
were more likely to receive treatment with a single class of antibiotic (64% vs
27%; P<.001). CONCLUSION: In this study, implementation of a critical pathway
reduced the use of institutional resources without causing adverse effects on the
well-being of patients.
PMID- 10683054
TI - Outcome at age 4 years in offspring of women with maternal phenylketonuria: the
Maternal PKU Collaborative Study.
AB - CONTEXT: Untreated maternal phenylketonuria (PKU) increases risk for
developmental problems in offspring. The extent to which this risk is reduced by
maternal dietary therapy at various stages of pregnancy is not known. OBJECTIVE:
To determine whether dietary treatment during pregnancy of women with PKU affects
developmental outcomes of offspring. DESIGN: The Maternal PKU Collaborative
Study, an ongoing, longitudinal prospective study begun in 1984. SETTING: A total
of 78 metabolic clinics and obstetrical offices in the United States, Canada, and
Germany. PARTICIPANTS: A total of 253 children of women with PKU (n = 149), with
untreated mild hyperphenylalaninemia (n = 33), or without known metabolic
problems (comparison group; n = 71) were followed up to age 4 years.
INTERVENTION: Women with PKU were offered a low-phenylalanine diet prior to or
during pregnancy with the aim of maintaining metabolic control (plasma
phenylalanine < or =10 mg/dL [< or =605 micromol/L]). Women with mild
hyperphenylalaninemia, who had plasma phenylalanine levels of no more than 10
mg/dL (605 micromol/L) on a normal diet, were not treated. MAIN OUTCOME MEASURES:
Children's scores on cognitive and behavioral assessments (McCarthy Scales of
Children's Abilities, Test of Language Development, Achenbach Child Behavior
Checklist, Vineland Adaptive Behavior Scales, and Home Observation for
Measurement of the Environment), compared by maternal metabolic status at 0 to 10
weeks', 10 to 20 weeks', and after 20 weeks' gestation. RESULTS: Scores on the
McCarthy General Cognitive Index decreased as weeks to metabolic control
increased (r = -0.58; P<.001). Offspring of women who had metabolic control prior
to pregnancy had a mean (SD) score of 99 (13). Forty-seven percent of offspring
whose mothers did not have metabolic control by 20 weeks' gestation had a General
Cognitive Index score 2 SDs below the norm. Overall, 30% of children born to
mothers with PKU had social and behavioral problems. CONCLUSIONS: Our data
suggest that delayed development in offspring of women with PKU is associated
with lack of maternal metabolic control prior to or early in pregnancy. Treatment
at any time during pregnancy may reduce the severity of delay.
PMID- 10683056
TI - End-of-life care content in 50 textbooks from multiple specialties.
AB - CONTEXT: Prior reviews of small numbers of medical textbooks suggest that end-of
life care is not well covered in textbooks. No broad study of end-of-life care
content analysis has been performed on textbooks across a wide range of medical,
pediatric, psychiatric, and surgical specialties. OBJECTIVE: To determine the
quantity and rate the adequacy of information on end-of-life care in textbooks
from multiple medical disciplines. DESIGN AND SOURCES: A 1998 review of 50 top
selling textbooks from multiple specialties (cardiology, emergency medicine,
family and primary care medicine, geriatrics, infectious disease and acquired
immunodeficiency syndrome [AIDS], internal medicine, neurology, oncology and
hematology, pediatrics, psychiatry, pulmonary medicine, and surgery) for the
presence and adequacy of content in 13 end-of-life care domains. MAIN OUTCOME
MEASURES: Chapters on diseases commonly causing death and those devoted to end-of
life care were identified, read, rated, and compared by textbook specialty,
chapter, and domain for the presence of helpful information in the 13 domains.
Content for each domain was rated as absent, minimally present, or helpful.
Textbook indexes were analyzed for the number of pages relevant to end-of-life
care. RESULTS: Overall, helpful information was provided in 24.1% (range, 8.7%
44.2%) of the expected end-of-life content domains; in 19.1% (range, 6.2%-38.5%),
expected content received minimal attention; and in 56.9% (range, 23.1 %-77.9%),
expected content was absent. As a group, the textbooks with the highest
percentages of absent content were in surgery (71.8%), infectious diseases and
AIDS (70%), and oncology and hematology (61.9%). Textbooks with the highest
percentage of helpful end-of-life care content were in family medicine (34.4%),
geriatrics (34.4%), and psychiatry (29.6%). In internal medicine textbooks, the
content domains with the greatest amount of helpful information were epidemiology
and natural history. Content domains covered least well were social, spiritual,
ethical, and family issues, as well as physician after-death responsibilities. On
average, textbook indexes cited 2% of their total pages as pertinent to end-of
life care. CONCLUSION: Top-selling textbooks generally offered little helpful
information on caring for patients at the end of life. Most disease-oriented
chapters had no or minimal end-of-life care content. Specialty textbooks with
information about particular diseases often did not contain helpful information
on caring for patients dying from those diseases.
PMID- 10683055
TI - Testosterone replacement and resistance exercise in HIV-infected men with weight
loss and low testosterone levels.
AB - CONTEXT: Previous studies of testosterone supplementation in HIV-infected men
failed to demonstrate improvement in muscle strength. The effects of resistance
exercise combined with testosterone supplementation in HIV-infected men are
unknown. OBJECTIVE: To determine the effects of testosterone replacement with and
without resistance exercise on muscle strength and body composition in HIV
infected men with low testosterone levels and weight loss. DESIGN AND SETTING:
Placebo-controlled, double-blind, randomized clinical trial conducted from
September 1995 to July 1998 at a general clinical research center. PARTICIPANTS:
Sixty-one HIV-infected men aged 18 to 50 years with serum testosterone levels of
less than 12.1 nmol/L (349 ng/dL) and weight loss of 5% or more in the previous 6
months, 49 of whom completed the study. INTERVENTIONS: Participants were randomly
assigned to 1 of 4 groups: placebo, no exercise (n = 14); testosterone enanthate
(100 mg/wk intramuscularly), no exercise (n = 17); placebo and exercise (n = 15);
or testosterone and exercise (n = 15). Treatment duration was 16 weeks. MAIN
OUTCOME MEASURES: Changes in muscle strength, body weight, thigh muscle volume,
and lean body mass compared among the 4 treatment groups. RESULTS: Body weight
increased significantly by 2.6 kg (P<.001) in men receiving testosterone alone
and by 2.2 kg (P = .02) in men who exercised alone but did not change in men
receiving placebo alone (-0.5 kg; P = .55) or testosterone and exercise (0.7 kg;
P = .08). Men treated with testosterone alone, exercise alone, or both
experienced significant increases in maximum voluntary muscle strength in leg
press (range, 22%-30%), leg curls (range, 18%-36%), bench press (range, 19%-33%),
and latissimus pulls (range, 17%-33%). Gains in strength in all exercise
categories were greater in men assigned to the testosterone-exercise group or to
the exercise-alone group than in those assigned to the placebo-alone group. There
was a greater increase in thigh muscle volume in men receiving testosterone alone
(mean change, 40 cm3; P<.001 vs zero change) or exercise alone (62 cm3; P = .003)
than in men receiving placebo alone (5 cm3; P = .70). Average lean body mass
increased by 2.3 kg (P = .004) and 2.6 kg (P<.001), respectively, in men who
received testosterone alone or testosterone and exercise but did not change in
men receiving placebo alone (0.9 kg; P = .21). Hemoglobin levels increased in men
receiving testosterone but not in those receiving placebo. CONCLUSION: Our data
suggest that testosterone and resistance exercise promote gains in body weight,
muscle mass, muscle strength, and lean body mass in HIV-infected men with weight
loss and low testosterone levels. Testosterone and exercise together did not
produce greater gains than either intervention alone.
PMID- 10683057
TI - Oral androstenedione administration and serum testosterone concentrations in
young men.
AB - CONTEXT: Androstenedione, a steroid hormone and the major precursor to
testosterone, is available without prescription and is purported to increase
strength and athletic performance. The hormonal effects of androstenedione,
however, are unknown. OBJECTIVE: To determine if oral administration of
androstenedione increases serum testosterone levels in healthy men. DESIGN: Open
label randomized controlled trial conducted between October 1998 and April 1999.
SETTING: General clinical research center of a tertiary-care, university
affiliated hospital. PARTICIPANTS: Forty-two healthy men aged 20 to 40 years.
INTERVENTION: Subjects were randomized to receive oral androstenedione (either
100 mg/d [n = 15] or 300 mg/d [n = 14]) or no androstenedione (n = 13) for 7
days. MAIN OUTCOME MEASURES: Changes in serum testosterone, androstenedione,
estrone, and estradiol levels, measured by frequent blood sampling, compared
among the 3 treatment groups. RESULTS: Mean (SE) changes in the area under the
curve (AUC) for serum testosterone concentrations were -2% (7%), -4% (4%), and
34% (14%) in the groups receiving 0, 100, and 300 mg/d of androstenedione,
respectively. When compared with the control group, the change in testosterone
AUC was significant for the 300-mg/d group (P<.001) but not for the 100-mg/d
group (P = .48). Baseline testosterone levels, drawn 24 hours after
androstenedione administration, did not change. Mean (SE) changes in the AUC for
serum estradiol concentrations were 4% (6%), 42% (12%), and 128% (24%) in the
groups receiving 0, 100, and 300 mg/d of androstenedione, respectively. When
compared with the control group, the change in the estradiol AUC was significant
for both the 300-mg/d (P<.001) and 100-mg/d (P = .002) groups. There was marked
variability in individual responses for all measured sex steroids. CONCLUSIONS:
Our data suggest that oral androstenedione, when given in dosages of 300 mg/d,
increases serum testosterone and estradiol concentrations in some healthy men.
PMID- 10683058
TI - Effect of out-of-hospital pediatric endotracheal intubation on survival and
neurological outcome: a controlled clinical trial.
AB - CONTEXT: Endotracheal intubation (ETI) is widely used for airway management of
children in the out-of-hospital setting, despite a lack of controlled trials
demonstrating a positive effect on survival or neurological outcome. OBJECTIVE:
To compare the survival and neurological outcomes of pediatric patients treated
with bag-valve-mask ventilation (BVM) with those of patients treated with BVM
followed by ETI. DESIGN: Controlled clinical trial, in which patients were
assigned to interventions by calendar day from March 15, 1994, through January 1,
1997. SETTING: Two large, urban, rapid-transport emergency medical services (EMS)
systems. PARTICIPANTS: A total of 830 consecutive patients aged 12 years or
younger or estimated to weigh less than 40 kg who required airway management; 820
were available for follow-up. INTERVENTIONS: Patients were assigned to receive
either BVM (odd days; n = 410) or BVM followed by ETI (even days; n = 420). MAIN
OUTCOME MEASURES: Survival to hospital discharge and neurological status at
discharge from an acute care hospital compared by treatment group. RESULTS: There
was no significant difference in survival between the BVM group (123/404 [30%])
and the ETI group (110/416 [26%]) (odds ratio [OR], 0.82; 95% confidence interval
[CI], 0.61-1.11) or in the rate of achieving a good neurological outcome (BVM,
92/404 [23%] vs ETI, 85/416 [20%]) (OR, 0.87; 95% CI, 0.62-1.22). CONCLUSION:
These results indicate that the addition of out-of-hospital ETI to a paramedic
scope of practice that already includes BVM did not improve survival or
neurological outcome of pediatric patients treated in an urban EMS system.
PMID- 10683059
TI - Genital herpes and public health: addressing a global problem.
AB - Genital herpes can be caused by herpes simplex virus 2 (HSV-2) or, less commonly,
by herpes simplex virus 1 (HSV-1). With a seroprevalence of antibodies to HSV-2
of 22% in the general population, genital herpes is 1 of the 3 most prevalent
sexually transmitted diseases (STDs) in the United States. A central issue in the
public health problem of genital herpes is the high proportion of genital HSV
infections that are unrecognized by both patients and clinicians. Persons who are
HSV-2 seropositive may be symptomatic but nevertheless fail to recognize genital
herpes; they serve as reservoirs for transmission. Physicians and patients must
be aware of the subclinical presentation of genital herpes and the potential
these patients have for transmitting HSV. Serious consequences of HSV infection
include neonatal herpes and increased risk of human immunodeficiency virus
transmission. Recommendations to physicians for prevention include using type
specific tests for HSV when screening for other STDs and testing for HSV when
evaluating patients with genital ulcers. Researchers must evaluate the
performance of type-specific tests and strategies to prevent transmission.
PMID- 10683060
TI - Threats to the confidentiality of medical records--no place to hide.
PMID- 10683061
TI - Out-of-hospital intubation of children.
PMID- 10683062
TI - Uses and abuses of prescription drug information in pharmacy benefits management
programs.
AB - A 1998 incident in which patients' prescription information was used to advertise
a new drug exemplifies the importance of confidentiality in the era of managed
care and computers. The ethical concerns voiced about this incident can also
apply to pharmacy benefits management programs. The use of personal health
information in pharmacy benefits management is particularly important because of
increased pressures to control rising drug costs. Specific confidentiality
concerns include whether the goal of benefiting patients will be achieved and
whether the means are appropriate. The means may be problematic because of
financial conflicts of interest, lack of patient authorization, inappropriate
access to information by third parties, and inadequate safeguards for
confidentiality. Policies should be crafted that protect confidentiality while
allowing appropriate use of personal health information in pharmacy benefits
management. Sound policies should require clear evidence of benefit to patients,
an oversight committee, patient authorization, disclosure or prohibition of
conflicts of interest, additional safeguards for sensitive medical conditions,
strong confidentiality protections, and restrictions on advertising.
PMID- 10683063
TI - JAMA Patient Page: pneumonia.
PMID- 10683064
TI - Follicular carcinoma of the thyroid gland: prognostic factors, treatment, and
survival.
AB - Prognostic variables and treatment outcomes of 82 patients treated at the
Northern Israel Oncology Center were reviewed. There were 59 women and 23 men in
this series. The female/male ratio was 2.6/1. Median age was 46 years. Median
follow-up was 11.4 (range: 3.8-24 years). Median tumor size was 3.6 cm. When
first seen, 4 patients had lymph node involvement and 11 (13%) had distant
metastases. Surgical treatment was total thyroidectomy in 37 patients (45%),
subtotal thyroidectomy in 38 (46%), and lesser procedures in 7 (9%). Sixty-six
patients (80%) were treated after surgery with 131I to ablate thyroid remnants.
Doses ranged between 30 and 80 mCi. The 20-year overall actuarial survival rate
was 65%. The actuarial survival rate of patients <40 years of age was 96% versus
33% in patients >50 years of age (p = 0.0008). Patients with distant metastases
at presentation had inferior survival compared with patients without metastases.
In conclusion, we found subtotal thyroidectomy followed by 131I and hormone
therapy to provide survival similar to that with total thyroidectomy, with less
morbidity. Risk factors include: age > or =40 at the time of diagnosis, presence
of distant metastases, capsular invasion, tumor size > or =2 cm, and male gender.
PMID- 10683065
TI - Comparison of preoperative embolization followed by radical nephrectomy with
radical nephrectomy alone for renal cell carcinoma.
AB - A series of 474 patients with renal cell carcinoma (RCC), who had radical
nephrectomy during a period of 15 years, was studied to assess the prognostic
significance of various pathologic parameters (tumor stage [pT], lymph node
status, metastasis, tumor grade, venous involvement) and value of preoperative
embolization of renal artery. There were: 20 (4%) pT1, 204 (43%) pT2, 245 (52%)
pT3, and 5 (1%) pT4 patients. All 474 patients underwent nephrectomy including a
group of 118 (25%) patients (24 pT2, 90 pT3, and 4 pT4) who underwent
preoperative embolization of the renal artery. To compare treatment outcomes in
embolized patients with RCC, a group of 116 (24%) nonembolized patients with RCC
was selected. This group was matched for sex, age, stage, tumor size, and tumor
grade, with the embolized patients (p<0.01). All important prognostic factors
were studied as to their influence on survival by the treatment group. The
overall 5- and 10-year survival was 62% and 47%, respectively. The 5- and 10-year
survival rates were significantly better (p<0.01) for patients with pT2 than for
those with pT3 tumors (79% vs. 50% and 59% vs. 35%, respectively). Involvement of
regional lymph nodes (N+) was an important prognostic factor for survival in
patients with pT3 tumors. The 5-year survival for pT3 N+ was 39%, compared with
66% in those with pT3N0 (p<0.01). Preoperative embolization was also an important
factor influencing survival. The overall 5- and 10-year survival for 118 patients
embolized before nephrectomy was 62% and 47%, respectively, and it was 35% and
23%, respectively, for the matched group of 116 patients treated with surgery
alone (p = 0.01). The most important finding of this study was an apparent
importance of preoperative embolization in improving patients' survival. This
finding needs to be interpreted with caution and confirmed in a prospective
randomized trial.
PMID- 10683066
TI - A phase II trial of tamoxifen, ifosfamide, epirubicin, and cisplatin combination
chemotherapy for inoperable non-small-cell lung cancer.
AB - A phase II trial of tamoxifen, ifosfamide, epirubicin, and cisplatin (TIEP)
chemotherapy was conducted in patients with chemonaive inoperable non-small-cell
lung cancer (NSCLC) to assess response and toxicity. From October 1997 to August
1998, 19 patients were treated. The treatment schema included tamoxifen 60 mg
twice daily by mouth on days 1 to 3, ifosfamide 3 g/m2 intravenous infusion (IV)
60 minutes with mesna on day 2, epirubicin 50 mg/m2 IV bolus on day 2, and
cisplatin 60 mg/m2 IV 60 minutes on day 2 every 4 weeks for up to six cycles. All
patients were evaluable for response and toxicity. The major toxicity was
myelosuppression; grade 3 or 4 leukopenia or neutropenia occurred in 14 of 19
(73.7%) patients during treatment, and 6 patients (31.6%) experienced fever in
association with the neutropenia; no toxic deaths occurred. Grade 3 anemia
occurred in six patients (31.6%) during the treatment. Grade 3 or 4
nausea/vomiting occurred in only one patient. Toxicities other than neutropenia
and anemia were minimal. After two cycles of treatment, 9 of 19 patients attained
a partial response (47.4%, 95% confidence interval 24.9%-69.9%) in this study.
The median time to disease progression was 6 months and median survival time was
12 months. We conclude that TIEP is an active combination regimen with an
acceptable toxicity profile in Chinese patients with inoperable NSCLC.
PMID- 10683067
TI - Late pulmonary effects in favorable stage I and IIA Hodgkin's disease treated
with radiotherapy alone.
AB - Radiotherapy (RT) in patients with favorable-stage Hodgkin's disease can induce
clinical and subclinical evidence of pulmonary damage lasting over the years. In
this study, we monitored 36 patients with stage IA-IIA Hodgkin's disease treated
with subtotal nodal RT. The planned dose of RT was 40 Gy to 44 Gy to the involved
areas and 36 Gy to the adjacent uninvolved areas. Pulmonary function was
evaluated by chest radiograph, spirometric parameters, arterial blood gas
analysis, and single-breath CO transfer factor (DLCO). The tests were performed
before and at the end of irradiation, and during the follow-up 1 and 3 to 5 years
after the treatment. At the end of RT, we found a significant decrease of total
lung capacity, vital capacity, forced expiratory volume in 1 second, residual
volume, and DLCO. Spirometric parameters improved during the follow-up period,
whereas the decline of DLCO (-6.4%) was persistent. No correlation was found
between mantle RT dose and DLCO changes. Four patients showed a decline of DLCO
of >20% from pretreatment values but only one was symptomatic. Our study confirms
that RT induces a pulmonary-restrictive disease at a subclinical level that seems
to be reversible in the majority of patients.
PMID- 10683068
TI - Ambamustine in the second-line treatment of patients with small-cell lung cancer:
a phase II Fonicap study.
AB - Despite a high probability of response to first-line chemotherapy, most patients
with small-cell lung cancer (SCLC) will eventually have progression of their
disease because of the development of resistant disease. Second-line testing of
new drugs is an accepted research strategy in SCLC. In this context, the Italian
Lung Cancer Task Force (FONICAP) has tested a new synthetic bifunctional
alkylating agent, Ambamustine, with preliminary evidence of activity in other
solid tumors. Patients with measurable SCLC, progressive after one first-line
chemotherapy regimen (either "sensitive" or "refractory"), were eligible for the
study. Ambamustine was administered at the dose of 2 mg/kg as a 1-hour
intravenous infusion on day 1 every 21 days. The dose was to be increased to 3
mg/kg if no grade IV toxicity and complete hematologic recovery had occurred by
day 22. Sample size was calculated according to a two-stage optimal Simon's
design. Seventeen patients were entered into the study. Twelve patients were
refractory to prior chemotherapy; 12 had extensive disease; the median age was 64
years (range: 46-75 years) and the median performance status was 1. Among 13
patients who received more than one cycle, 9 patients could increase Ambamustine
dose from 2 to 3 mg/kg. No objective response was observed: one patient obtained
a 50% regression of the primary tumor with contemporary disease progression in
the liver and was qualified as having progressive disease. The treatment was well
tolerated: grade IV leukopenia occurred in only 1 patient; grade III anemia
occurred in 17.6%, grade III leukopenia in 11.8%, and grade III thrombocytopenia
in 23.5%. Nonhematologic toxicity was minimal. Ambamustine, at the dose and
schedule used in this study, is well tolerated in pretreated patients with SCLC
but has no significant antitumor activity in this unfavorable group of patients.
PMID- 10683069
TI - Kaposi sarcoma after treatment of Hodgkin's disease in a young adult non-AIDS
patient: case report and review.
AB - We describe a young woman diagnosed with Hodgkin's disease, stage I, at age 20
years. She delayed treatment until age 23, at which time she was considered to
have stage II-A disease and was then treated with chemotherapy and involved field
irradiation. Two years later, Kaposi sarcoma, which developed on her right
shoulder, was excised. Both the Hodgkin's disease and Kaposi sarcoma appeared to
be cured, but 3 years later, acute myelogenous leukemia developed and the patient
subsequently died in relapse. This is one of the very few instances of a young
patient, not infected with the AIDS virus, in whom Kaposi sarcoma developed as a
second malignancy after treatment of Hodgkin's disease.
PMID- 10683070
TI - 'Full dose' reirradiation of human cervical spinal cord.
AB - With the progress of modern multimodality cancer treatment, retreatment of late
recurrences or second tumors became more commonly encountered in management of
patients with cancer. Spinal cord retreatment with radiation is a common problem
in this regard. Because radiation myelopathy may result in functional deficits,
many oncologists are concerned about radiation-induced myelopathy when retreating
tumors located within or immediately adjacent to the previous radiation portal.
The treatment decision is complicated because it requires a pertinent assessment
of prognostic factors with and without reirradiation, radiobiologic estimation of
recovery of occult spinal cord damage from the previous treatment, as well as
interactions because of multimodality treatment. Recent studies regarding
reirradiation of spinal cord in animals using limb paralysis as an endpoint have
shown substantial and almost complete recovery of spinal cord injury after a
sufficient time after the initial radiotherapy. We report a case of "full" dose
reirradiation of the entire cervical spinal cord in a patient who has not
developed clinically detectable radiation-induced myelopathy on long-term follow
up of 17 years after the first radiotherapy and 5 years after the second
radiotherapy.
PMID- 10683071
TI - Thoracic wall prosthesis prevents deep invasion by non-small-cell lung cancer.
AB - Chest wall invasion is found in 5% of patients with non-small-cell lung cancer.
Treatment for localized non-small-cell lung cancer consists of surgical resection
and/or radiotherapy. We report a patient with lung cancer who had a local relapse
after a reconstruction of the thoracic wall with a soft-tissue patch.
Chemotherapy was given before reresection of the local relapse. Postoperative
radiation therapy was performed. Twenty-one months after treatment for recurrent
disease, the patient remains in complete remission. The history of this patient
shows that a soft-tissue patch may prevent local tumor invasion. A review of the
literature is given.
PMID- 10683072
TI - Sustained ventricular tachycardia and its successful prophylaxis during high-dose
bolus interleukin-2 therapy for metastatic renal cell carcinoma.
AB - In the setting of interleukin-2 (IL-2) administration, tachycardias of
ventricular origin are classified as serious, grade IV toxicities, necessitating
the discontinuation of therapy. In this report, we describe a patient with renal
cell carcinoma who experienced ventricular tachycardia while undergoing treatment
with high-dose bolus IL-2. Prophylaxis with sotalol permitted the successful
completion of his first cycle of treatment, without any recurrent rhythm
disturbances.
PMID- 10683073
TI - A phase II trial of 5-fluorouracil, leucovorin, and interferon alpha 2A (IFN
alpha 2a) in metastatic pancreatic carcinoma: a Penn Cancer Clinical Trials Group
(PCCTG) trial.
AB - A phase II study was performed to evaluate the activity and toxicity of 5
fluorouracil (5-FU), leucovorin, and inteferon alpha-2a in metastatic pancreatic
carcinoma. Twenty-three patients were entered in this study. Four patients
withdrew before receiving treatment and one patient was nonevaluable for response
because of treatment-related toxicity. The most common significant toxicity was
nausea and vomiting. Treatment-related hospitalization was significant. Of 18
evaluable patients, 4 maintained stable disease and 14 had disease progression.
None had an objective clinical response. We conclude that this biochemically
modulated 5-FU regimen is ineffective treatment for advanced pancreatic
carcinoma, with significant toxicity even in highly selected patients with an
ambulatory performance status.
PMID- 10683074
TI - Continuous-infusion high-dose leucovorin with 5-fluorouracil and cisplatin for
relapsed metastatic breast cancer: a phase II study.
AB - Twelve women with metastatic breast cancer were treated with continuous infusion
high dose leucovorin, 5-fluorouracil and cisplatin. Toxicity was severe although
the dose was lower than previously described for the treatment of other cancers,
and there was little anti-tumor activity. Many other regimens are more effective
and less toxic.
PMID- 10683075
TI - Pyomyositis after chemotherapy for breast cancer.
AB - Pyomyositis is a rare complication of chemotherapy. A 47-year-old woman with
metastatic breast cancer, in whom pyomyositis developed after chemotherapy, is
described. It was difficult to differentiate between pyomyositis and deep venous
thrombosis early in her admission. Pyomyositis should be considered part of the
differential diagnosis of deep venous thrombosis. This infection, after
chemotherapy, usually is considered to be caused by neutropenia or
immunodeficiency secondary to the cancer, or both. It is postulated that
subclinical myopathy, secondary to the malignancy or drugs used in treating the
malignancy, or both, may also predispose to pyomyositis.
PMID- 10683076
TI - Treatment of squamous cell esophageal cancer with topotecan: an Eastern
Cooperative Oncology Group Study (E2293).
AB - Seventeen patients with enhanced measurable squamous cell carcinoma of the
esophagus were treated with topotecan 1.5 mg/m2 daily for 5 days repeated every
21 days. Toxicity was severe, with 1 death from myelotoxicity and 10 patients
with life-threatening myelotoxicity. Severe gastrointestinal toxicity consisting
of vomiting was also seen in three patients. No response was seen in any of the
patients in the study. Topotecan given in this manner has no activity in squamous
cell carcinoma of the esophagus.
PMID- 10683077
TI - Accuracy and clinical impact of mediastinal lymph node staging with FDG-PET
imaging in potentially resectable lung cancer.
AB - To determine the sensitivity, specificity, and accuracy of staging mediastinal
nodal disease in potentially resectable lung cancer using fluorodeoxyglucose
positron emission tomography (FDG-PET), computed tomography (CT), or both and
compare these results to surgical staging. We also assessed whether PET scanning
results changed clinical management. From 1992 to 1997, 50 patients underwent CT,
and PET scanning before or close to the time of surgical staging. Sensitivity,
specificity, accuracy, and predictive values were then calculated based on
pathology results. A retrospective review of the records was performed to
determine how PET results affected clinical treatment decisions. Forty-seven of
50 patients had non-small-cell lung cancer. The prevalence of pathologically
confirmed mediastinal and hilar involvement was 38%. The sensitivity,
specificity, and accuracy of mediastinal disease staging were as follows: CT
alone = 73%, 77%, 76%; PET alone = 73%, 94%, 87%; PET + CT = 82%, 96%, 91%,
respectively. PET was more specific and accurate than CT (p = 0.025). The results
of PET changed management decisions in 12 of 50 cases (24%). Using FDG-PET in
conjunction with CT scanning provides the most accurate staging of mediastinal
disease in lung cancer by contributing complementary information. Furthermore,
PET can affect clinical decision-making and allow some patients considered
unresectable a chance for resection.
PMID- 10683078
TI - The roles of chemotherapy and surgery in gastric carcinoma and the influence of
prognostic factors on survival.
AB - In this study, we present the results of surgery and chemotherapy and the impact
of various prognostic factors on survival in patients with gastric carcinoma with
a follow-up of 6 years. All of the 328 cases were adenocarcinoma histologically
and had a median age of 55 years. Median survival was 11 months, and the 5-year
survival rate was 18%. Nonmetastatic cases were associated with improved survival
as compared with the cases with metastatic disease (p<0.001). Patients with
gastrectomy had improved survival (p<0.001). Subtotal gastrectomized patients had
better survival rates in comparison to the total gastrectomized patients (p =
0.03). Addition of splenectomy to total gastrectomy and adjuvant chemotherapy did
not influence survival rates (p>0.05). In metastatic patients, we determined
beneficial effects of gastrectomy and chemotherapy on survival. The benefit was
most predominant in chemoresponsive patients (p<0.001). Higher serum CA 19.9
levels in patients without metastases, higher serum lactate dehydrogenase and
carcinoembryonic antigen levels in patients with metastases, and lower serum
albumin levels in both stages were determined as significant predictors of poor
survival. On multivariate analysis, only higher serum CA 19.9 level was the
independent unfavorable prognostic factor of survival time in nonmetastatic
patients (p = 0.008). In metastatic disease, older age (p = 0.03) and male gender
(p = 0.05) were associated with poorer survival. In conclusion, gastric cancer is
a great health problem, especially in developing countries, and we need more
optimal approaches and treatment modalities for gastric cancer.
PMID- 10683079
TI - Poorly differentiated carcinoma of the lung presenting with Lambert--Eaton
myasthenic syndrome.
AB - Lambert-Eaton myasthenic syndrome commonly seen in small-cell lung cancer
represents an autoimmune reaction against antigens coexpressed by tumor and
neurons. It is rarely seen with other histologic subtypes. Symptoms antedate the
appearance of the neoplasm by weeks to years. Therapeutic options range from
immunosuppression, plasmapheresis, pharmacologic facilitation of neuromuscular
transmission, and definitive therapy of the primary tumor. This case report
describes the rare association of Lambert-Eaton myasthenic syndrome with non
small-cell lung cancer.
PMID- 10683080
TI - A phase II trial of vinorelbine and cisplatin in previously untreated inoperable
non--small-cell lung cancer.
AB - Weekly vinorelbine injection with cisplatin had been used in treatment of non
small-cell lung cancer. We performed a phase II trial to evaluate the efficacy
and toxicity of a new schedule of vinorelbine and cisplatin in patients with
previously untreated, inoperable (stage IIIB or stage IV) non-small-cell lung
cancer. From April 1996 to May 1997, 52 patients were enrolled for study, and 50
patients were eligible and evaluable for both response and toxicity assessment.
Therapy consisted of vinorelbine, 30 mg/m2, intravenously on days 1 and 5 of a 21
day cycle, and cisplatin 100 mg/m2 (reduced to 80 mg/m2 after the first seven
patients) given on day 1. A total of 211 treatment courses were administered; the
median number of cycles administered per patient was 4.5 (range: 1-6), the median
dose intensity for vinorelbine was 16.9 mg/m2/week (84.4%), whereas that of
cisplatin was 22.8 mg/m2/week (84.7%). Twenty-five patients responded to therapy
for an overall response rate of 50%; one patient attained a complete response
(2%). The main toxicities were vomiting, myelosuppression, and diarrhea, which
included World Health Organization grade 3 or 4 nausea/vomiting (58% patients),
anemia (41% patients), neutropenia (12% patients), and diarrhea (14%). The median
duration of responses was 9 months. The median time to disease progression was
6.8 months (range 0.4-18.1 months). Median survival was 13 months, and 54% of
patients were alive at 1 year. We conclude that this new schedule of vinorelbine
and cisplatin achieves a high response with acceptable toxicity profile in
patients with advanced non-small-cell lung cancer.
PMID- 10683081
TI - Oral etoposide for Merkel cell carcinoma in patients previously treated with
intravenous etoposide.
AB - We describe three patients with advanced Merkel cell carcinoma who were treated
with etoposide given orally for recurrent regional lymph node involvement 18 to
30 months after exposure to etoposide given intravenously. Etoposide given orally
(100 mg/day) was given for 10 to 14 consecutive days and repeated every 21 to 28
days for a median of three courses (range: two to four). Toxicity was minimal and
mainly hematologic. Two patients showed a complete response and one a partial
response, all of very rapid onset. All three patients are alive 6, 9, and 42
months from the start of oral treatment. Two remain progression free, and one had
a recurrence 1 month after completion of chemotherapy. We suggest that orally
administered etoposide, a topoisomerase II inhibitor, has a strong antitumor
effect in advanced Merkel cell carcinoma, even in patients previously treated
parenterally with the same drug. This action may be explained by the greater
dependence of the drug's efficacy on the duration of administration rather than
the dose intensity.
PMID- 10683082
TI - Phase II study of doxorubicin and paclitaxel as second-line chemotherapy of small
cell lung cancer: a Hoosier Oncology Group Trial.
AB - Forty-six evaluable patients with recurrent small-cell lung cancer were entered
on a phase II Hoosier Oncology Group (HOG) protocol evaluating bolus doxorubicin
40 mg/m2 followed by paclitaxel 175 mg/m2 over 3 hours. Courses were repeated
every 3 weeks for a maximum of 6 courses. Therapy was well-tolerated with grade
III neurotoxicity in 5 patients (11%), grade III/IV emesis in 5 (11%), and grade
III mucositis in 2 patients. One patient had grade IV myalgias and one patient
had grade III cardiotoxicity. The main toxicity was myelosuppression. Twenty-nine
patients (63%) had grade IV and 8 (17%) grade III granulocytopenia. Nine patients
(20%) were hospitalized for granulocytopenic fever. There was no treatment
related mortality. Nineteen of 46 patients (41%) had an objective response,
including 3 complete remissions. Two of 14 patients with refractory disease
(progression less than 3 months after initial therapy) responded, compared to 17
of 32 (52%) with sensitive disease (progression beyond 3 months of initial
chemotherapy regimen).
PMID- 10683083
TI - Warfarin is safe as secondary prophylaxis in patients with cancer and a previous
episode of venous thrombosis.
AB - The purpose of this study was to establish the safety and efficacy of sodium
warfarin in the secondary prophylaxis of venous thrombosis in patients with
cancer. This was an inception cohort study of patients enrolled in an
anticoagulation clinic between July 1991 and October 1996. The rates of bleeding
and recurrent thrombosis were evaluated in all the patients, and the results in
patients with cancer (n = 104) were compared with those without cancer (n = 208).
The rate of major hemorrhage was 0.4% and 0.3% per treatment month in the
patients with cancer and those without cancer, respectively. The rates of
recurrent thrombosis were 1.2% and 0.2% per treatment month in the patients with
cancer compared with those without cancer, respectively. We conclude that
warfarin is safe when used for the secondary prophylaxis of patients with cancer
who have had a venous or arterial thrombosis, and the risk of major hemorrhage is
not significantly different when compared with the risk in patients without
cancer. The rate of recurrent thrombosis is approximately sixfold higher in
patients with cancer being treated with warfarin for secondary prophylaxis of
thrombosis compared with patients without cancer. Nonetheless, the rate of
recurrent thrombosis is not overly excessive, and warfarin can be viewed as a
relatively effective form of therapy for these patients.
PMID- 10683084
TI - Thrombotic thrombocytopenic purpura in metastatic carcinoma of the breast.
AB - We present a case of a 52-year-old woman with thrombotic thrombocytopenic purpura
associated with progressive metastatic adenocarcinoma of the breast. The patient
received plasma exchange therapy. Thrombocytopenic purpura resolved 2 months
after discontinuation of plasma exchange while the patient received chemotherapy.
After 3 more months, a fulminant relapse of the thrombocytopenic purpura
developed, and there were signs of tumor progression. She died despite adequate
treatment. We conclude that effective treatment of the underlying tumor can be
crucial to control cancer-associated thrombocytopenic purpura.
PMID- 10683085
TI - A phase I trial of gemcitabine and infusional 5-fluorouracil (5-FU) in patients
with refractory solid tumors: Louisiana Oncology Associates protocol no. 1 (LOA
1).
AB - The major purposes of this study were to determine the maximally tolerated dose
(MTD), dose-limiting toxicity (DLT), toxicity profile, and antitumor activity of
gemcitabine (GEM) (Gemzar) and 5-fluorouracil (5-FU) combination therapy when
administered to patients with advanced solid tumors. GEM was administered
intravenously over 30 minutes on days 1, 8, and 15, and 5-FU was administered as
a continuous intravenous infusion from day 1 through day 15 of each 28-day
treatment course. Seventeen patients (13 men and 4 women, median age 57, all
previously treated with chemotherapy) were treated with 68 courses at 3 dose
levels: 800/200, 1,000/200, and 1,000/300 [GEM (mg/m2/week)/ 5-FU (mg/m2/day)].
Two further patients were not fully evaluable for toxicity; one died from a
probable pulmonary embolism, and one refused further treatment after developing
grade II mucositis and dermatitis after her day 1 to 7 treatment. At the third
dose level, 2 of 4 patients developed grade III mucositis; one also developed
grade IV neutropenia with fever and grade III thrombocytopenia. Patient accrual
then resumed at the second dose level. At this level, 10 patients were treated,
with two developing grade III mucositis. One of these patients also developed
grade IV dermatitis. No other patient developed grade III or IV side effects.
Prophylactic dexamethasone was initiated after 4 of the first 7 patients
(including 1 of the not fully evaluable patients) developed dermatitis-grade IV
in 1 patient and grade II in the remaining 3 patients. After the steroids were
initiated, 4 of the last 11 patients treated developed dermatitis, but grade 1 in
all cases. One patient with metastatic gastric cancer achieved a near-complete
response of his gastric mass and adrenal metastasis. Minor responses were
achieved in a patient with colon carcinoma and a patient with an ethmoid sinus
adenoid cystic carcinoma. The MTD and recommended dose for phase II clinical
trials of GEM and 5-FU on the above schedule is 1,000 mg/m2 and 200 mg/m2
respectively, with mucositis as the DLT.
PMID- 10683086
TI - Preliminary results of the use of Re-186-HEDP for palliation of pain in patients
with metastatic bone disease.
AB - We evaluated the effectiveness of Re-186-HEDP in 25 patients with painful
metastatic bone disease. Twenty-five patients with known prostatic (n = 19), non
small-cell lung cancer (n = 1) and breast cancer (n = 5) and multiple confirmed
skeletal metastases were studied. All were taking analgesics daily (nonsteroidal
antiinflammatory drugs/opiates). Re-186-HEDP (mean 35.2 mCi) was administered and
patients were monitored for at least 50 days. In five patients, a repeat dose was
administered 9 to 10 weeks later. The evaluation of the analgesic effect was
based on a "pain diary" and by recording the use of analgesics. In 80% (20 of 25)
of the patients, the effect was significant palliation, moderate in 3 patients
(12%), and insignificant in 2 (8%). No significant myelotoxicity was observed.
Transient pain flare was recorded in 8 of 25 patients. These results indicate
that Re-186-HEDP can offer pain palliation in patients with painful bone
metastases without being complicated by significant myelotoxicity.
PMID- 10683087
TI - Short-course palliative radiotherapy in non-small-cell lung cancer: results of a
prospective study.
AB - From February 1993 to October 1997, 91 consecutive patients with inoperable
(stage IIIB-IV) histologically confirmed non-small-cell lung cancer underwent
palliative hypofractionated radiotherapy. Recently, the Medical Research Council
studies on hypofractionated short-course radiotherapy (8.5 Gy x 2) have reported
high control of symptoms caused by thoracic disease without toxicity. Based on
these experiences and our previous positive trial on short-course radiotherapy (8
Gy x 2) in metastatic spinal cord compression, a prospective study of short
course palliative radiotherapy in non-small-cell lung cancer was carried out. The
regimen was 16 Gy given in two 8-Gy fractions, 1 week apart. Eighty-one patients
were evaluable for response to treatment. Forty-eight (59%) patients were 65
years or older. Forty (49%) patients were naive to radiotherapy, whereas 41 (51%)
had previous cisplatin-based chemotherapy. All but four stage IV patients (95%)
had poor Eastern Cooperative Oncology Group performance status (i.e., 2-3).
Clinical palliation was achieved in 62 (77%) patients. Performance status
improved in 59 (73%) patients. The median palliation time ranged from 28% to 57%
of patient survival. The median survival from the beginning of treatment was 148
days (range, 5-681 days). No difference in overall survival according to stage
and previous chemotherapy was observed. Only performance status conditioned
survival (performance status 1-2 vs. performance status 3; p = 0.0289). Short
course radiotherapy gave good results in terms of clinical palliation for
thoracic symptoms, even in patients with poor performance status and pretreated
with chemotherapy. The median palliation time was approximately 50% of patient
survival time. Treatment was generally well tolerated-only 4 (5%) patients
experienced World Health Organization grade III dysphagia. No late toxicity was
recorded. The two-fraction regimen had social and economic advantages compared
with the conventional ones.
PMID- 10683088
TI - Standard dose (Mayo regimen) 5-fluorouracil and low dose folinic acid:
prohibitive toxicity?
AB - Despite the perception that standard 5-fluorouracil/folinic acid (5-FU/FA) (425
mg/m2 per day and 20 mg/m2 per day intravenously once daily x 5 every 4 or 5
weeks) is well tolerated, we have been impressed by toxicity seen and frequent
need for dose modification. We performed a retrospective analysis to quantitate
the proportion of patients experiencing toxicity and attempted to identify
associated clinical characteristics. One hundred thirty-four patients received 5
FU/FA at standard doses described by the Mayo regimen. Patient characteristics
were as follows: female 35%, median age 66 years, Eastern Cooperative Oncology
Group performance status less than or equal to 2, 96%. Sixty-eight percent
received chemotherapy for metastatic disease. Forty-seven patients (35%+/-8%)
experienced significant toxicity and were unable to receive the second cycle as
scheduled: 76% required dose reduction, 11% discontinued therapy (including two
toxic deaths), 11% discontinued therapy during the first cycle, and 2% required
dose delay. Logistic regression was used to explore the following as predictors
of toxicity: age, sex, performance status, adjuvant versus metastatic setting,
prior chemotherapy, prior radiation, mean corpuscular volume, red blood cell
distribution width, albumin, alkaline phosphatase, aspartate aminotransferase,
bilirubin, and calculated creatinine clearance. No clinical characteristic was
found to predict toxicity. Only high bilirubin approached statistical
significance. We conclude that standard 5-FU/FA, when used in the general
population, is associated with significant toxicity. Known clinical
characteristics are not helpful in predicting toxicity. The lack of previous
formal phase I evaluation of this regimen of 5-FU/FA raises concerns regarding
its safety and generalizability in clinical practice.
PMID- 10683089
TI - Synchronous primary cancers of the breast and cervix: planning multidisciplinary
primary treatment [clinico-pathological conference].
AB - Multiple metachronous primary malignancies are becoming increasingly frequent;
however, multiple synchronous primary malignancies are still unusual. We report
the case of a 61-year-old woman with synchronous stage IIIB ductal carcinoma of
the left breast and FIGO stage IB2 squamous cell carcinoma of the cervix. The
patient was treated initially every 4 weeks with a 24-h intravenous infusion of
paclitaxel (175 mg/m2) followed by a 1-h infusion of carboplatin (area under the
curve of 5 mg/ml x min) with concurrent irradiation of the pelvis. Significant
toxic reactions including nausea, vomiting, and diarrhea required hospitalization
or outpatient intravenous fluids and antiemetics. After four cycles of
chemotherapy, the breast cancer was in complete clinical remission, and the
patient underwent a modified radical mastectomy with axillary lymph node
dissection. Pathologic findings revealed a few microscopic foci of residual
infiltrating ductal carcinoma exhibiting a marked treatment effect; none of the
14 axillary lymph nodes removed showed evidence of metastatic tumor. A near
complete pathologic response of the breast cancer and a complete clinical
response of the cervical cancer were obtained. Adjuvant chemotherapy for the
breast cancer was then initiated, followed by radiation and hormonal therapy.
PMID- 10683090
TI - Correlation between water proton spin lattice relaxation time and radiation
tolerance dose in normal human tissue.
PMID- 10683091
TI - Exercise and insulin sensitivity: a review.
AB - Physical activity has a beneficial effect on insulin sensitivity in normal as
well as insulin resistant populations. A distinction should be made between the
acute effects of exercise and genuine training effects. Up to two hours after
exercise, glucose uptake is in part elevated due to insulin independent
mechanisms, probably involving a contraction-induced increase in the amount of
GLUT4 associated with the plasma membrane and T-tubules. However, a single bout
of exercise can increase insulin sensitivity for at least 16 h post exercise in
healthy as well as NIDDM subjects. Recent studies have accordingly shown that
acute exercise also enhances insulin stimulated GLUT4 translocation. Increases in
muscle GLUT4 protein content contribute to this effect, and in addition it has
been hypothesized that the depletion of muscle glycogen stores with exercise
plays a role herein. Physical training potentiates the effect of exercise on
insulin sensitivity through multiple adaptations in glucose transport and
metabolism. In addition, training may elicit favourable changes in lipid
metabolism and can bring about improvements in the regulation of hepatic glucose
output, which is especially relevant to NIDDM. It is concluded that physical
training can be considered to play an important, if not essential role in the
treatment and prevention of insulin insensitivity.
PMID- 10683092
TI - Dietary creatine monohydrate supplementation increases satellite cell mitotic
activity during compensatory hypertrophy.
AB - Nutritional status influences muscle growth and athletic performance, but little
is known about the effect of nutritional supplements, such as creatine, on
satellite cell mitotic activity. The purpose of this study was to examine the
effect of oral creatine supplementation on muscle growth, compensatory
hypertrophy, and satellite cell mitotic activity. Compensatory hypertrophy was
induced in the rat plantaris muscle by removing the soleus and gastrocnemius
muscles. Immediately following surgery, a group of six rats was provided with
elevated levels of creatine monohydrate in their diet. Another group of six rats
was maintained as a non-supplemented control group. Twelve days following
surgery, all rats were implanted with mini-osmotic pumps containing the thymidine
analog 5-bromo-2'-deoxyuridine (BrdU) to label mitotically active satellite
cells. Four weeks after the initial surgery the rats were killed, plantaris
muscles were removed and weighed. Subsequently, BrdU-labeled and non-BrdU-labeled
nuclei were identified on enzymatically isolated myofiber segments. Muscle mass
and myofiber diameters were larger (P < 0.05) in the muscles that underwent
compensatory hypertrophy compared to the control muscles, but there were no
differences between muscles from creatine-supplemented and non-creatine
supplemented rats. Similarly, compensatory hypertrophy resulted in an increased
(P < 0.05) number of BrdU-labeled myofiber nuclei, but creatine supplementation
in combination with compensatory hypertrophy resulted in a higher (P < 0.05)
number of BrdU-labeled myofiber nuclei compared to compensatory hypertrophy
without creatine supplementation. Thus, creatine supplementation in combination
with an increased functional load results in increased satellite cell mitotic
activity.
PMID- 10683093
TI - Dehydroepiandrosterone (DHEA) rather than testosterone shows saliva androgen
responses to exercise in elite female handball players.
AB - The aim of the investigation was to evaluate in fourteen elite female handball
players the resting values of saliva levels of testosterone -- T -- and
dehydroepiandrosterone -- DHEA -- in comparison with ten sedentary women and the
response to exercise of the same hormones in handball players. Saliva samples
were taken from the handball players upon wakening (resting values) (8 a. m.), 5
minutes before and after a simulated handball match (6 p. m.; 8 p. m.) and upon
wakening the following morning (8 a. m. + 24 h). The samples of saliva from the
sedentary controls were taken at the same time of day but the controls did not
perform any exercise. Resting hormonal levels were lower in handball players than
in controls (P < 0.01). The exercise did not induce significant changes in T and
DHEA salivary concentrations in handball players. Positive correlations between
testosterone concentrations and DHEA were observed at all the time points
studied. These findings showed that the T and DHEA concentrations followed a
remarkably similar pattern. Considering the very low concentrations of
testosterone in women, in particular in saliva, and its biosynthetic pathway, we
suggest that measurements of DHEA could serve as a substitute for testosterone
measurements to study training responses in elite sportswomen.
PMID- 10683094
TI - Reduction of the plasma concentration of C-reactive protein following nine months
of endurance training.
AB - An intense physical exercise induces an inflammatory reaction as demonstrated by
the delayed increase in blood of acute phase proteins and among them of C
reactive protein (CRP). There is also evidence for a diminished acute phase
reaction due to regular exercise suggesting a suppression of the inflammatory
response through training. With this background CRP was measured by a sensitive
enzyme immunoassay under resting conditions before and after 9 months of training
in 14 subjects preparing for a marathon with the aim of studying the effect of
training on the base-line CRP concentration. The mean distance run per week
increased significantly from 31 +/- 9 km at the beginning to 53 +/- 15 km after 8
months of training (p < 0.01). The aerobic capacity rose significantly after
training as demonstrated by the increase of running velocity during a maximal
treadmill test from 3.82 +/- 0.29 m/s pre-training to 4.17 +/- 0.17 m/s post
training at a blood lactate concentration of 4 mmol/L (p < 0.01). In 10 of 12
runners base-line CRP was diminished after training in spite of a continuous
increase of training intensity. The CRP median fell from 1.19 mg/L before to 0.82
mg/L after training (p < 0.05). Since intense physical exercise is known to be
associated with an inflammatory reaction of muscles and tendons, the CRP decrease
was unexpected. In 2 subjects the CRP concentration rose markedly because of a
borrelia infection and a knee injury, respectively. These values were caused by a
pathological condition and were not considered for the statistical evaluation. In
10 non-training control subjects the CRP median did not change significantly
during the same 9 months period. The decrease of the CRP base-line concentration
after training suggests that intensive regular exercise has a systemic anti
inflammatory effect. This is of particular interest with regard to several recent
reports confering on the concentration of CRP in plasma a predictive value for
the risk of cardiac infarction, venous thrombosis or stroke.
PMID- 10683095
TI - The effect of free glutamine and peptide ingestion on the rate of muscle glycogen
resynthesis in man.
AB - The present study investigated previous claims that ingestion of glutamine and of
protein-carbohydrate mixtures may increase the rate of glycogen resynthesis
following intense exercise. Eight trained subjects were studied during 3 h of
recovery while consuming one of four drinks in random order. Drinks were ingested
in three 500 ml boluses, immediately after exercise and then after 1 and 2 h of
recovery. Each bolus of the control drink contained 0.8 g x kg(-1) body weight of
glucose. The other drinks contained the same amount of glucose and 0.3 g x kg(-1)
body weight of 1) glutamine, 2) a wheat hydrolysate (26% glutamine) and 3) a whey
hydrolysate (6.6% glutamine). Plasma glutamine, decreased by approximately 20%
during recovery with ingestion of the control drink, no changes with ingestion of
the protein hydrolysates drinks, and a 2-fold increase with ingestion of the free
glutamine drinks. The rate of glycogen resynthesis was not significantly
different in the four tests: 28 +/- 5, 26 +/- 6, 33 +/- 4, and 34 +/- 3 mmol
glucosyl units x kg(-1) dry weight muscle x h(-1) for the control, glutamine,
wheat- and whey hydrolysate ingestion, respectively. It is concluded that
ingestion of a glutamine/carbohydrate mixture does not increase the rate of
glycogen resynthesis in muscle. Glycogen resynthesis rates were higher, although
not statistically significant, after ingestion of the drink containing the wheat
(21 +/- 8%) and whey protein hydrolysate (20 +/- 6%) compared to ingestion of the
control and free glutamine drinks, implying that further research is needed on
the potential protein effect.
PMID- 10683096
TI - The slow component of O2 uptake kinetics during high-intensity exercise in
trained and untrained prepubertal children.
AB - The aim of the present study was to investigate the O2 uptake slow component in
prepubertal children of different aerobic capacity during high intensity
exercise. Twenty-three (12 well-trained, T and 11 untrained, U subjects) 10-13
year old prepubertal children took part in 3 tests: one incremental test to
determine the maximal aerobic power (PMA) and anaerobic threshold (LAT); two
constant-power tests performed at intensities corresponding to 80%LAT and 90%PMA.
Oxygen uptake (VO2), heart rate, ventilation (VE) and lactate ([L]s) were
evaluated during each test. A monoexponential + linear term model (starting after
phase 1) was used to assess VO2 kinetics during both constant-power tests. Our
results showed that a slow component, represented by the linear coefficient (S)
of the mathematical model, was present during the 90%PMA test only (S = 0.86 +/-
0.48 ml x min(-2) x kg(-1) for the whole population). No relationships were found
between either S and VE or [L]s, showing that, at least in prepubertal children,
these factors play a minor role in the explanation for the VO2 slow component.
The slow component contributed approximately to the same amount of the total VO2
response in both groups (T: 21.4 +/- 8.0, U: 19.3 +/- 3.9%, ns). In conclusion,
as previously described in adults, our data demonstrated the existence of a slow
component in prepubertal children during high-intensity exercise. Moreover, this
slow component was similar in trained and untrained children, exercising at the
same relative intensity.
PMID- 10683097
TI - The stability of lactate concentration in preserved blood microsamples.
AB - This study aimed to determine the stability of lactate concentration in blood
samples preserved and stored using methods practical for field testing and
experimental applications. Whole blood microsamples were obtained from venous
samples drawn from 10 healthy subjects following bouts of moderate (approximately
5 mmol x l(-1), n = 12), or intense (approximately 10 mmol x l(-1), n = 12),
treadmill exercise. Samples were analysed fresh (2 x 25 microl), or placed in
preservative-containing tubes (12 x 75 microl) and analysed directly, or after
storage at room temperature (RT) or 4 degrees C, for 1 h, 18 h, 2 d, 3 d or 7 d,
or at -20 degrees C for 7 d. In comparison to preserved samples assayed directly
after collection, lactate levels in all RT samples had declined significantly,
whereas the 4 degrees C samples had not changed, by 2 d post-collection. After 7
d of refrigeration, the absolute value of the difference from lactate levels in
samples measured after collection (mean +/- SD) was 0.38 +/- 0.34 mmol x l(-1),
or 5.3 +/- 4.3%; with freezing, this difference was 0.27 +/- 0.27 mmol x l(-1),
or 3.6 +/- 3.0%. These differences were less than the daily variation in the
analyser readings of a 10 mmol x l(-1) standard, indicating that the blood
preservation and storage methods identified herein are suitable for use during
exercise testing.
PMID- 10683098
TI - Joint excursion, handle velocity, and applied force: a biomechanical analysis of
ergonometric rowing.
AB - Rowers may sacrifice on-water technique during ergonometric training in an
attempt to increase stroke output. This cross-sectional study aimed to identify
characteristics of ergonometric rowing technique that could be potentially
detrimental to an effective and safe on-water performance. Joint excursion,
handle velocity, and applied force were measured in 44 athletes while they
performed a 2500 meter race on an instrumented ergometer. Results on four
subjects are presented here. Their performance is compared to that of a Barcelona
Olympic and World champion rower with 12 years of experience to illustrate how
athletes deviate from standard on-water technique. Kinematic data showed knee
joint oscillations and out-of-phase hip and knee joint reversals. Horizontal
handle velocity curves indicated that higher stroke rates were achieved by a
decrease in recovery time. Vertical handle velocity curves exhibited bi
directional variations. The largest amplitude occurred at the end of the drive
phase during an upward displacement of the handle that was associated with a jerk
in the applied force. Force-time curves at different stroke rates showed greater
variability in the initial portion of the drive phase. Perpetuation of these
technique deviations may be detrimental to on-water performance. Biomechanical
analyses may allow coaches to better monitor technique during ergonometric
training.
PMID- 10683099
TI - Heart rate and blood pressure variability during heavy training and overtraining
in the female athlete.
AB - We investigated heavy training- and overtraining-induced changes in heart rate
and blood pressure variability during supine rest and in response to head-up tilt
in female endurance athletes. Nine young female experimental athletes (ETG)
increased their training volume at the intensity of 70-90% of maximal oxygen
uptake (VO2max) by 125% and training volume at the intensity of < 70% of VO2max
by 100% during 6-9 weeks. The corresponding increases in 6 female control
athletes were 5% and 10%. The VO2max of the ETG and the control athletes did not
change, but it decreased from 53.0 +/- 2.2 ml x kg(-1) x min(-1) to 50.2 +/- 2.3
ml x kg(-1) x min(-1) (mean+/-SEM, p < 0.01) in five overtrained experimental
athletes. In the ETG, low-frequency power of R-R interval (RRI) variability
during supine rest increased from 6 +/- 1 ms2 x 10(2) to 9 +/- 2 ms2 x 10(2) (p <
0.05). The 30/15 index (= RRI(max 30)/RRI(min 15), where RRI(max 30) denotes the
longest RRI close to the 30th RRI and RRI(min 15) denotes the shortest RRI close
to the 15th RRI after assuming upright position in the head-up tilt test),
decreased as a result of training (analysis of variance, p = 0.05). In the ETG,
changes in VO2max were related to the changes in total power of RRI variability
during standing (r = 0.74, p < 0.05). Heart rate response to prolonged standing
after head-up tilt was either accentuated or attenuated in the overtrained
athletes as compared to the normal training state. We conclude that heavy
training could increase cardiac sympathetic modulation during supine rest and
attenuated biphasic baroreflex-mediated response appearing just after shifting to
an upright position. Heavy-training-/overtraining-induced decrease in maximal
aerobic power was related to decreased heart rate variability during standing.
Physiological responses to overtraining were individual.
PMID- 10683100
TI - A new index of coordination for the crawl: description and usefulness.
AB - This study analyzes stroke phases and arm and leg coordination during front crawl
swimming as a function of swim velocity and performance level. Forty-three
swimmers constituted three groups based on performance level. All swam at three
different swim velocities, corresponding to the paces appropriate for the 800 m,
100 m, and 50 m. The different stroke phases and the arm and leg coordination
were identified by video analysis. Arm coordination was quantified using a new
index of coordination (IdC), which expresses the three major modalities
opposition, catch-up and superposition. Opposition, where one arm begins the pull
phase when the other is finishing the push phase; catch up, which has a lag time
(LT) between propulsive phases of the two arms; and superposition, which
describes an overlap in the propulsive phases. The IdC is an index which
characterizes coordination patterns by measure of LT between propulsive phases of
each arm. The most important results showed that duration of the propulsive
phases (B + C) increased significantly with increasing velocity: 43.1 +/- 3.3%
for V800; 46.5 +/- 3% for V100 and 49 +/- 3% for V50. The arm and leg
synchronization was modified in the sense of an increase in six-beat kick. The
IdC increased significantly with velocity: IdCV800 = -7.6 +/- 6.4%; IdCV100 =
3.2 +/- 5.1% and IdCV50 = -0.9 +/- 5.6%. IdC increased also significantly with
performance level: IdCG3 = -6.07 +/- 5.3%; IdCG2 = -3.9 +/- 4.2% and IdCG1 =
1.76 +/- 5.6% for the mean of the 3 velocity. The two extreme IdC were IdCG3V800
= -9.4 +/- 5.4% and IdCG1V50 = +2.53 +/- 4.4%.
PMID- 10683101
TI - Energetically optimal cadence vs. freely-chosen cadence during cycling: effect of
exercise duration.
AB - The purpose of this study was to examine the relationship between cadence and
oxygen consumption with exercise duration. Ten triathletes who trained regularly
were examined. The first test was always a maximal test to determine maximal
oxygen uptake (VO2max). The other sessions were composed of six submaximal tests
representing 80% of the maximal power reached with VO2max (Pmax). During these
tests submaximal rides with a duration of 30 min were performed. Each test
represented, in a randomised order, one of the following pedal rates: 50, 65, 80,
95, 110 rpm and a freely-chosen rate. VO2, respiratory parameters, and heart rate
were monitored continuously. Two periods, between the 3rd and the 6th minute and
between the 25th and the 28th minute, were analysed. Results showed that when VO2
and heart rate were plotted against cadence, each curve could be best described
by a parabolic function, whatever the period. Furthermore, a significant effect
of period was found on energetically optimal cadence (70 +/- 4.5 vs. 86 +/- 6.2
rpm, P < 0.05). Only during the second period was no significant difference found
between freely-chosen cadence (83 +/- 6.9 rpm) and energetically optimal cadence
(P > 0.05). In conclusion, our results suggest that during prolonged exercise
triathletes choose a cadence that is close to the energetically optimal cadence.
A change of muscle fibre recruitment pattern with exercise duration and cadence
would explain the shift in energetically optimal rate towards a higher pedal rate
observed at the end of exercise.
PMID- 10683102
TI - The effect of a sports drink on gastroesophageal reflux during a run-bike-run
test.
AB - The effects of different modes of prolonged exercise and different drinks on
gastroesophageal reflux and reflux-related symptoms were examined. In a cross
over design seven male triathletes performed two tests at one week intervals (50
min periods of alternately running, cycling and running at 70-75% VO2max), with
supplementation of either a conventional sports drink (7% carbohydrates) or tap
water. Gastroesophageal reflux (percentage time and number of periods esophageal
pH < 4) was measured with an ambulant pH system before, during and after
exercise. Percentage reflux time (+/- SEM) during running, cycling, running and
recovery was 24.0 +/- 4.6, 8.2 +/- 4.8, 17.6 +/- 8.4 and 11.8 +/- 4.0 with
carbohydrates and 7.4 +/- 2.9, 0 +/- 0, 2.4 +/- 1.4 and 0.2 +/- 0.2 with water,
respectively. Reflux lasted longer during exercise as compared to the rest
situation (5.6 + 1.4%), especially with carbohydrates, and lasted longer with
carbohydrates than with water (P < 0.05; Wilcoxon signed rank test). In general,
reflux lasted longer during running than during cycling (P < 0.05). Data on the
number of reflux periods are concordant to these results. Chest pain was reported
by one subject during running with carbohydrates. Heartburn during running was
reported by two subjects with water and by one with carbohydrates. In conclusion,
physical exercise increases gastroesophageal reflux, dependent on the mode of
exercise and beverage used.
PMID- 10683103
TI - Acute creatine supplementation in older men.
AB - The hypothesis of this study was that short term creatine (Cr) ingestion in older
individuals would increase body mass and exercise performance, as has been shown
in younger subjects. Seventeen males 60-78 years old were randomly placed into
two groups, Cr and placebo (P), and supplemented in double-blind fashion for 5
days. Subjects ingested either 5 g of Cr plus 1 g of sucrose 4x per day or 6 g of
a sucrose placebo 4x per day. Isometric strength of the elbow flexors was
assessed using a modified preacher bench attached to a strain gauge. Isokinetic
exercise performance was assessed using an intermittent fatigue test of the knee
extensors. Subjects performed 3 sets of 30 repetitions with 60 sec rest between
sets. There was a small (0.5 kg) but statistically significant increase in body
mass (p < 0.05) in the Cr group after supplementation. There was a significant
overall interaction between groups in isokinetic performance from pre to post
supplementation (group x time x set, p < 0.05). However, analysis of the groups
separately revealed that the subjects in the Cr group demonstrated a small non
significant increase in isokinetic performance while subjects in the P group
demonstrated a small non-significant performance decrement. There was no
significant difference in isometric strength between groups from pre to post
supplementation. These data suggest that acute oral Cr supplementation does not
increase isometric strength and only produces small increases in isokinetic
performance and body mass in men over the age of 60.
PMID- 10683104
TI - Incomplete restoration of immobilization induced softening of young beagle knee
articular cartilage after 50-week remobilization.
AB - The aim of this study was to characterize the biomechanical and structural
changes in canine knee cartilage after an initial 11-week immobilization and
subsequent remobilization period of 50 weeks. Cartilage from the immobilized and
remobilized knee was compared with the tissue from age-matched control animals.
Compressive stiffness, in the form of instant shear modulus (ISM) and equilibrium
shear modulus (ESM) of articular cartilage, was investigated using an in situ
indentation creep technique. The local variations in cartilage of
glycosaminoglycan (GAG) concentration were measured with a microspectrophotometer
after safranin O staining of histological sections. Using a computer-based
quantitative polarized light microscopy method, collagen-related optical
retardation, gamma, of cartilage zones were performed to investigate the collagen
network of cartilage. Macroscopically, cartilage surfaces of the knee joint
remained intact both after immobilization and remobilization periods.
Immobilization caused significant softening of the lateral femoral and tibial
cartilages, as expressed by ESM (up to 30%, p < 0.05). Remobilization restored
the biomechanical properties of cartilage in the lateral condyle of tibia, but in
the lateral condyle of femur ESM remained 15% below the control level (p = 0.05).
The instant shear modulus was not changed either after immobilization or
remobilization. The GAG content of the cartilage was slightly decreased after
immobilization, especially in the superficial zone of cartilage, but the change
was not statistically significant. After remobilization the intensity of safranin
O content rose to control level. Neither immobilization nor remobilization had
any effect on the gamma value of collagen fibril network either in the
superficial or the deep zone at any of the test points. The changes of ESM were
positively correlated with the alterations in GAG content of the superficial and
deep zones after immobilization and remobilization. This confirms the key role of
protoglycans in the regulation of the equilibrium stiffness of articular
cartilage. As a conclusion, immobilization of the joint of a young individual may
cause long-term, if not permanent, alterations of cartilage biomechanical
properties. This may predispose joint to degenerative changes later in life.
PMID- 10683105
TI - Avian behavioural neuroscience: past, present and future perspectives.
AB - A survey of avian brain-behavior conference reports of the last 25 years reveals
that neither the avian species studied nor the types of scientific questions
asked have changed very much since the first such conference report in 1974. The
birds studied tend, for the most part, to be pigeons, chickens, quail, and
canaries. Because of the growing interest in avian vocalization and its neural
control, one recent conference featured studies of canaries, zebra finches, and
budgerigars. The topics of investigation at these conferences largely have
involved sensory systems, mostly sensory and sensorimotor mechanisms with a heavy
emphasis on vision and audition, as well as studies of learning and memory.
Future research should expand the range of orders and species of birds studied so
as to shed light on evolutionary trends within Aves as a whole. The scope of
behavioral questions asked also should be broadened to include topics of
neuroethological interest.
PMID- 10683106
TI - Visual circuits of the avian telencephalon: evolutionary implications.
AB - Birds and primates are vertebrates that possess the most advanced, efficient
visual systems. Although lineages leading to these two classes were separated
about 300 million years ago, there are striking similarities in their underlying
neural mechanisms for visual processing. This paper discusses such similarities
with special emphasis on the visual circuits in the avian telencephalon. These
similarities include: (1) the existence of two parallel visual pathways and their
distinct telencephalic targets, (2) anatomical and functional segregation within
the visual pathways, (3) laminar organization of the telencephalic targets of the
pathways (e.g. striate cortex in primates), and (4) possible interactions between
multiple visual areas. Additional extensive analyses are necessary to determine
whether these similarities are due to inheritance from a common ancestral stock
or the consequences of convergent evolution based on adaptive response to similar
selective pressures. Nevertheless, such a comparison is important to identify the
general and specific principles of visual processing in amniotes (reptiles,
birds, and mammals). Furthermore, these principles in turn will provide a
critical foundation for understanding the evolution of the brain in amniotes.
PMID- 10683107
TI - Functional subdivisions of the ascending visual pathways in the pigeon.
AB - This study represents an attempt to examine an alternative view of the functional
architecture of the ascending visual pathways in pigeons. According to this
conception the pars dorsalis (GLd) of the thalamofugal system represents the
lateral monocular field of view and is frontally blind to a large extent. The
tectofugal system, on the other hand, processes frontal visual input within the
framework of asymmetrical tectorotundal connections. As a result, the left, but
not the right, rotundus should be able to integrate to an important degree the
input from both eyes via the tecta of both hemispheres. Two lesion studies were
conducted to test these assumptions. In the first psychophysical experiment, the
visual acuity was determined in head-fixed pigeons. After thresholds were
determined, stereotaxic lesions were placed in the GLd and/or the rotundus.
Multiple regressions between structure specific lesion extents and postoperative
threshold alterations demonstrated that only GLd lesions contributed to acuity
reductions. In the second experiment the acuity threshold of pigeons under
binocular and monocular conditions was determined in a conventional skinner box
before GLd and/or rotundus lesions. Multiple regression analyses showed that
rotundus--but not GLd lesions--contributed to performance losses. The left
rotundus lesions were significantly related to threshold elevations under both
monocular conditions, while the right rotundus only contributed together with the
left rotundus to binocular performance. The double dissociation revealed in these
experiments indicates that the ascending pathways in pigeons are functionally
segregated and differentially process frontal and lateral as well as left- and
right-sided inputs.
PMID- 10683108
TI - Functional anatomy of the avian centrifugal visual system.
AB - Although first described over a century ago, the centrifugal visual system (CVS)
projecting to the retina still remains somewhat of an enigma with regard to its
functional role in visually-guided behavior. The highly developed avian CVS has
been the most extensively investigated and the anatomical organization of its two
component centrifugal structures, the n. isthmo-opticus (NIO) and ectopic neurons
(EN), including its afferent brainstem projections is reviewed. The results of
double-labeling studies combining axonal tracing techniques and
immunohistofluorescence have demonstrated GABA immunoreactivity (-ir) of
interneurons within the neuropilar zone of the NIO, choline acetyltransferase
(ChAT)-ir and nitric oxide synthase (NOS)-ir in the centrifugal cells of the NIO
and EN as well as in the afferent projection neurons of layers 9/10 of the optic
tectum. The data are discussed in terms of neurochemical and
excitatory/inhibitory mechanisms within the different components of the avian CVS
in relation to hypotheses which have implicated this system in visual attention
and ground-feeding behavior.
PMID- 10683109
TI - The dorsocaudal neostriatum of the domestic chick: a structure serving higher
associative functions.
AB - The dorsocaudal neostriatal (dNC) complex consists of at least three functionally
distinct subregions and is part of an 'imprinting' pathway, which interconnects
several forebrain regions that are known to be involved in juvenile learning.
Based on its anatomical features, at least one subregion of the dNC complex, the
neostriatum dorsocaudale (Ndc) may be considered as the equivalent of the
mammalian polysensory association cortices. Several lines of evidence point to a
role for this forebrain region in learning and memory formation. After auditory
or visual imprinting changes of stimulus-evoked metabolic activities and of
synaptic densities have been measured in the Ndc. Pharmacological behavioral
studies revealed that the activation of NMDA receptors plays a critical role
during this learning process and that NMDA receptor activation is required for
the associated metabolic and synaptic changes. In addition to glutamatergic
afferents, anatomical studies revealed a massive input from monoaminergic and
peptidergic pathways into the dNC complex, suggesting a modulatory role for these
systems during imprinting. The results presented here together with data from
other avian species support the view that the dNc complex, and in particular the
Ndc, plays an important role in juvenile and adult learning.
PMID- 10683110
TI - The avian hippocampal formation: subdivisions and connectivity.
AB - The avian hippocampal formation (HP) is considered to be homologous to the
mammalian hippocampus on the basis of topography, developmental origin and its
role in processing spatial memory. However, the morphological organization of the
avian HP is very different from that of mammals and components similar to the
subdivisions of the mammalian structure are not readily recognizable. In
passerine birds, three spatially and morphologically distinct populations of
Calbindin immunoreactive neurones are found in the dorsolateral (DL), dorsomedial
(DM) and ventral (V) aspects of HP. Iontophoresis of Phaseolus vulgaris
leucoagglutinin revealed three consistently different projection patterns arising
from the different subregions. Generally, there is a medial-to-lateral
topographical organization of efferents in relation to the septal complex. The DL
region could be paralleled to the subiculum of mammals with its main projections
to the basal ganglia, the limbic archistriatum, the lateral septum and the
paraxial meso-diencephalic centres. The 'V' subdivision is likely to be
homologous to the Ammon's horn of mammals with its commissural projections to the
contralateral HP. Based on its purely intrinsic connectivity, the DM region could
be a good candidate for an equivalent of the dentate gyrus. Nitric oxide synthase
(NOS) containing neural structures display a specific distribution within the
hippocampal subregions which is uniform in all passerine species studied.
However, there is a marked difference in the level of diffuse neuropil reactivity
between food-storers versus non-storers. Unlike the mammalian homologue, avian
hippocampal NOS positive neurones do not show a near complete co-localization
with the inhibitory transmitter GABA.
PMID- 10683111
TI - Striato-telencephalic and striato-tegmental circuits: relevance to learning in
domestic chicks.
AB - Memory formation for a passive avoidance task in the domestic chick is likely to
involve a hyperstriatum ventrale (IMHV)-archistriatum-lobus parolfactorius (LPO)
arc. The present study summarises previous findings, relevant to this neural
system, and is also supplemented with some recent data from our laboratory.
Projections from the IMHV on the archistriatum, as well as from the archistriatum
on the LPO, have been characterised using a combination of anterograde pathway
tracing (Phaseolus lectin), and post-embedding GABA and glutamate
immunocytochemistry. The majority of IMHV efferents have been found to synapse
with dendritic spine heads and necks of densely spiny projection neurons of the
ventral archistriatum, and the ultrastructure of synapses suggested a potent
excitatory input. Similar synaptic connections of the excitatory type were
ultrastructurally verified between ventral archistriatal afferent terminals and
dendrites or spines of the LPO, suggesting an involvement of the medium sized
spiny neurons, which are typical of the striatum. Although some of the IMHV
boutons terminating in the archistriatum were immunoreactive to glutamate, this
was not observed in the archistriatal-LPO pathway. Tegmental connections of the
basal ganglia, in particular LPO, are also likely to play a role in processing of
the avoidance response. We have demonstrated reciprocal connections between the
LPO and dopaminergic (TH-positive) neurons of the substantia nigra and ventral
tegmentum. Dopamine D1 receptors were upregulated bilaterally in the LPO
following avoidance learning and this response was not accompanied by significant
changes in the level of dopamine or its metabolites (HVA, DOPAC), as revealed by
HPLC chromatography of brain samples dissected from the LPO of control and
trained chicks. The dopamine receptor-related phosphoprotein DARPP-32 was
localised in dendritic elements of the LPO, often forming asymmetric synapses
with glutamate immunoreactive axon terminals. The findings are consistent with a
scenario in which the striatum acts as a suppressor of natural pecking behaviour.
Learned visual association with the target (bead) occurs in the IMHV and is
relayed to the basal ganglia via the limbic archistriatum (amygdala equivalent),
the latter introducing a motivational element (aversion, fear). Suppression of a
brainstem pecking centre is likely to involve activation of the nigrostriatal
(tegmentostriatal) dopaminergic circuit.
PMID- 10683112
TI - Cellular correlates of stages of memory formation in the chick following passive
avoidance training.
AB - The process of memory formation has been investigated using the model of one
trial passive avoidance training in the one-day old domestic chick. We have
unraveled a biochemically coherent cascade of processes which, beginning with
transient ion and neurotransmitter flux, and by way of a sequence of interacting
pre- and post-synaptic intracellular signalling steps, results in gene activation
and the synthesis of cell adhesion molecules which appear to be the effective
agents in the structural processes involved in remodelling of synaptic and
neuronal circuits. Further, in a related series of experiments we have shown that
these biochemical and morphological changes are accompanied by significant
changes in the neurophysiological status of the neurons on the IMHV and LPO, in
particular in terms of their engagement in bouts of high-frequency firing.
However, much remains to be clarified, particularly the meaning of the time
dependent shifts in the location of the trace, and the ways in which these
molecular and cellular events translate into changes in behavior in the animal.
PMID- 10683113
TI - Early learning and the development of filial preferences in the chick.
AB - Newly hatched domestic chicks (Gallus gallus domesticus) rapidly form a social
preference for a conspicuous stimulus to which they are exposed. The learning
process involved is known as filial imprinting. When chicks are exposed to an
audio-visual compound stimulus, both auditory and visual learning are enhanced.
The enhancement of visual imprinting is virtually abolished when chicks are
exposed separately to the auditory element, either before or after training with
the audio-visual compound. Simultaneous exposure to the two elements of the
compound is superior to sequential exposure in achieving the enhancement of
visual learning. These results are unlike Pavlovian conditioning, but are
consistent with an interpretation of imprinting as a form of within-event
learning, where links are formed between the representations of the elements of
the compound, that can be weakened by separate exposure to an element. Apart from
imprinting, chicks may show a developing predisposition to approach stimuli
resembling conspecifics. The predisposition emerges in dark-reared chicks given
some non-specific experience during a sensitive period, and is expressed as a
relatively general preference for stimuli with a head and neck region. In the
natural situation, the animal's response may be biased by the predisposition, and
through imprinting it then learns the characteristics of individuals.
PMID- 10683114
TI - The recognition memory of imprinting: biochemistry and electrophysiology.
AB - A restricted part of the intermediate and medial part of the hyperstriatum
ventrale (IMHV) of the domestic chick forebrain is pivotal to the learning
process of imprinting and is probably the site at which information about an
imprinting stimulus is stored. A range of learning-related changes occur in the
IMHV between 1 and 24 h after training. The earliest change described is in Fos
like immunoreactivity. There follow changes in phosphorylation of the protein
kinase C substrate MARCKS, morphological changes in axospinous synapses, an
increase in NMDA receptor number and increases in amounts of the major isoforms
of the neural cell adhesion molecule and clathrin heavy chain. All but the change
in Fos-immunopositivity occurs in the left, but not the right, IMHV. Insufficient
nitric oxide synthase is available in the IMHV to support the hypothesis that
nitric oxide is a retrograde messenger contributing to the effect on Fos-like
immunoreactivity. In chicks anaesthetised approximately 24 h after imprinting
training, the spontaneous mean neuronal firing rate is related to a preference
score (a measure of learning). In unanaesthetised chicks 24 h after training, the
responsiveness of some IMHV neurons is biassed specifically towards the
imprinting stimulus.The responses of other neurons in the IMHV generalise across
some features of the training stimulus, such as form or colour. Some neurons in
the IMHV of unanaesthetised chicks are responsive to the distance of an
imprinting stimulus from the chick; distance-sensitive neurons can be
distinguished from distance-insensitive neurones by the action potential shape.
PMID- 10683115
TI - Electrophysiological correlates of past history: in vitro studies of the IMHV of
the domestic chick.
PMID- 10683116
TI - Behavioural and neurophysiological aspects of sexual imprinting in zebra finches.
AB - Sexual imprinting has been defined as the process by which young animals learn
the characteristics of their future sexual partners. It is a two stage process
including an acquisition period where features of the social environment are
learnt, and a stabilization process by which, under the guidance of the
previously acquired social information, a preference for a sexual partner is
established and stabilized, so that it cannot be altered again subsequently. The
stabilization process is short (1 h) and can be controlled experimentally. This
allows for the design of experiments to examine the physiological events
accompanying the imprinting process. During the stabilization process, four areas
of the forebrain are more activated than in any other behavioural context. These
are the hyperstriatum accessorium/dorsale (HAD), the archi-neostriatum caudale
(ANC), the medial neo/hyperstriatum (MNH) and the lateral neo/hyperstriatum
(LNH). Isolation during development reduces the spine density of neurons in HAD
and ANC and enhances it in MNH and LNH. Subsequent exposure to a female (which
stabilizes the previously acquired preference in behavioural experiments) for 1
week leads to an enhancement of spine densities in HAD and ANC, and to a
reduction in MNH and LNH. The enhancement in HAD and ANC is reversible by a
second isolation period after the exposure to a female, the reduction within MNH
and LNH is not. This irreversibility indicates that the reduction process within
MNH and LNH may be the anatomical manifestation of the imprinting process. The
examination of spine densities in the four brain areas after two experiments
which have been shown previously to affect the stabilization process in
behavioural experiments, confirms this idea.
PMID- 10683117
TI - Light experience and lateralization of the two visual pathways in the chick.
AB - Using retrograde labelling with the fluorescent tracer rhodamine B isocyanate
(RITC), we have examined the organisation of the thalamofugal and tectofugal
visual projections to the forebrain of the young chick. In addition, we have
investigated the influence of light exposure prior to hatching on the development
of the tectofugal visual projections. Our results for the thalamofugal
projections confirm those found previously; viz., that there are more projections
from the left side of the thalamus to the right hyperstriatum of the forebrain
than from the right side of the thalamus to the left hyperstriatum in males and
females. The organisation of the tectofugal visual projections to the rotundal
nuclei was more symmetrical (males only examined) although there was a trend
towards a greater number of projections from the left optic tectum to its
ipsilateral nucleus rotundus than from the right optic tectum to its ipsilateral
nucleus rotundus. There are numerous projections from the optic tecta to their
contralateral rotundal nuclei but, in contrast to reports for the pigeon, no
marked asymmetry was present in these. The ratio of contralateral to ipsilateral
projections revealed significant asymmetry for projections from the ventral
regions of the optic tecta and symmetry from the dorsal regions. Thus both visual
pathways of the chick have asymmetrical organisation but the asymmetry is much
greater in the thalamofugal pathway. The slight asymmetry in the tectofugal
projections may be determined by exposing the embryo to light just before
hatching, as known to be the case for thalamofugal projections.
PMID- 10683118
TI - The differential roles of right and left sides of the brain in memory formation.
AB - A series of transitions in chick memory formation, with sharp standard timings,
which were revealed by amnestic agents, coincide with a series of brief windows
of enhanced recall ('retrieval events'), repeating with periods of 16 min (left
hemisphere) and 25 min (right). Their timings were recently confirmed by: (1) the
demonstration of a brief dip in recall 5 min after each left hemisphere event in
the period 0-100 min, (2) spontaneous use of the eye providing direct input to
the hemisphere undergoing an event, and (3) good performance in a delayed match
to-sample task after 100 min, only at times of near, or exact coincidence (400
min) with right and left events. The exact coincidence is accompanied by a late
episode of consolidation, as is a transition in memory formation in the zebra
finch with precisely the same timing. Linkages between right and left versions of
a single experience appear to be established as a result of near coincidences of
events. The greater involvement of the left hemisphere in initiating such
interactions appears to be responsible for a wide range of asymmetries described
for interocular transfer and unilateral insult.
PMID- 10683119
TI - Scientific and trade groups clash over 'authoritative' statements for health
claims.
PMID- 10683120
TI - Rosiglitazone approved for treatment of type 2 diabetes.
PMID- 10683121
TI - Second selective COX-2 inhibitor receives marketing approval.
PMID- 10683122
TI - Drug review and postmarketing surveillance programs are sound, but systems
approach to risk management is needed, says FDA.
PMID- 10683123
TI - Report examines strategies for reducing breast cancer risk.
PMID- 10683124
TI - Translating an idea into a product at ASHP.
PMID- 10683125
TI - Improving the care of hemophiliacs by managing the drug benefit.
PMID- 10683126
TI - Improving ambulatory care through therapeutic interchange.
PMID- 10683127
TI - Charting the demand for pharmacists in the managed care era.
AB - The demand for pharmacists in the changing health care market is discussed. The
Pharmacy Manpower Project (PMP) evolved out of concerns raised in the late 1980s,
when the demand for pharmacists exceeded the supply. PMP collects, analyzes, and
disseminates data on pharmacy work force variables. PMP's Subcommittee to Study
Demand Issues was formed after the publication in 1995 of the Pew Health
Professions Commission report projecting dramatic surpluses of pharmacists. In
1996-97, the PMP subcommittee held a series of sessions to discuss the future
demand for pharmacists and their services. The panel identified a wide range of
work force projections, but it concluded that medication management problems in
the context of increasing prescription numbers and the emergence of data-driven
health care support a scenario of a steadily increasing demand for pharmacists
and pharmaceutical services. The data did not show that higher penetration by
managed care is associated with smaller pharmacy staffs or job loss in
institutions. There is little reason to expect the dramatic downsizing of the
pharmacy work force predicted by the third report of the Pew Commission. However,
retaining pharmacy roles that are useful to the system and satisfying to
pharmacists will require a continuation of current proactive measures by the
profession.
PMID- 10683128
TI - Survival differences associated with treatment of cytomegalovirus retinitis in
Maryland patients with AIDS, 1987-1994.
AB - Differences in survival related to treatment of cytomegalovirus (CMV) retinitis
in AIDS patients were studied. The medical records of adult AIDS patients who had
been diagnosed with CMV retinitis in a Maryland inpatient facility between
September 1987 and September 1994 were reviewed to assess determinants of
survival, including treatment with ganciclovir and foscarnet, use of zidovudine,
and demographic characteristics. The review was based on inpatient and outpatient
medical records and computerized data from the Maryland HIV Information System.
Of 212 AIDS patients with CMV retinitis, 123 (58.0%) were treated exclusively
with ganciclovir, 55 (25.9%) received foscarnet only, and the remaining 34
(16.1%) received both ganciclovir and foscarnet at some point after their
diagnosis for CMV retinitis. Patients who received both drugs survived
significantly longer after the diagnosis than patients who received either drug
by itself. The median time from diagnosis of CMV retinitis to death was 464 days
for patients receiving both drugs, 225 days for ganciclovir recipients, and 202
days for foscarnet recipients. Other positive predictors of survival were male
sex and use of zidovudine. Among Maryland adults with AIDS who were treated for
CMV retinitis between September 1987 and September 1994, the most common
treatment for the eye infection was ganciclovir. Patients receiving both
ganciclovir and foscarnet survived longer than those treated with either drug
alone.
PMID- 10683129
TI - Impact of interruptions and distractions on dispensing errors in an ambulatory
care pharmacy.
AB - A possible association between interruptions and distractions and the occurrence
of dispensing errors was investigated. Fourteen pharmacists and 10 technicians in
an ambulatory care pharmacy at a general medical-surgical hospital were tested
for distractibility by using the group embedded figures test (GEFT) as well as
for visual acuity and hearing. They were videotaped as they filled prescriptions
during a 23-day period in 1992. A study investigator compared each filled
prescription with the physician's written order, noted details of deviations,
verified with the pharmacist any errors that occurred, and asked the pharmacist
to correct the error if necessary. Interruptions and distractions were detected
and characterized by reviewing the videotapes. None of the study participants had
significant hearing or visual impairment. There was a significant association
between GEFT scores and error rates. A total of 5072 prescriptions were analyzed,
and 164 errors were detected, for an overall error rate of 3.23%. Wrong label
information was the most common type of error (80% of errors detected). A total
of 2022 interruptions (mean +/- S.D. per half hour per subject, 2.99 +/- 2.70)
and 2457 distractions (mean +/- S.D. per half hour per subject, 3.80 +/-3.17)
were detected. The error rate for sets of prescriptions with one or more
interruptions was 6.65% and for sets during which there were one or more
distractions, 6.55%. Interruptions and distractions per half hour were both
significantly associated with errors. In an ambulatory care pharmacy,
interruptions and distractions over a half-hour period were associated with
dispensing errors, a majority of which involved incorrect label information.
PMID- 10683130
TI - Creating a computerized database from administrative claims data.
AB - The creation of a computerized database from Medicaid administrative claims data
for research purposes is described. Researchers should consult with computer
experts at their institution before selecting software for data manipulation and
conversion. It is essential to have an accurate layout of the file record before
attempting to convert raw claims data into data sets or other data formats. The
location of data elements within the claim will vary depending on whether the
record comes from a provider, an institution, or a pharmacy. Each claim contains
a common header, a variable header, and a claim detail section. The difficulty in
analyzing data elements within a claim detail lies in locating the starting point
of the claim detail section. So that data elements not in character or numeric
formats can be converted, the file record layout must describe the exact format
of each data element and its COBOL notation. A data element dictionary is
necessary for translating data element coding into usable data. Data elements not
necessary for any planned analysis must be eliminated. The data are then
"cleaned" to remove any denied or reversed claims and claims that contain
incomplete or erroneous data. Regardless of the format data are obtained in, an
accurate file record layout and a data element dictionary are essential to the
conversion of administrative claims data into a computerized database for data
analysis and research purposes.
PMID- 10683131
TI - Economic and clinical impact of a pharmacy-based filgrastim protocol in oncology
patients.
AB - The effects of a clinical protocol for filgrastim use in oncology patients were
studied. A chart review was conducted for every fourth oncology inpatient who
received filgrastim at a community hospital between January and June 1996 to
determine how filgrastim was being used in the hospital's oncology patients. The
results were presented to the oncology committee, and a filgrastim protocol was
implemented. The protocol stated that filgrastim would be discontinued when the
absolute neutrophil count (ANC) was > or =1500 cells/mm3 for two days after the
neutrophil nadir. Six months after the protocol was implemented, a follow-up
evaluation was conducted by reviewing the chart for every fourth oncology patient
who received filgrastim between November 1996 and April 1997. Twenty-one patient
charts were reviewed before the protocol was implemented, and 34 charts were
reviewed after implementation. The results showed there was compliance with the
protocol for 19 (76%) of the 25 patients evaluable for compliance. Sixty-seven
percent of patients were febrile before the protocol was implemented, and 56%
were febrile afterward. Ten percent of patients had documented infections before
implementation, compared with 12% afterward. The average ANC at which filgrastim
was discontinued before and after the protocol was implemented was 6839 and 5538
cells/mm3, respectively. Filgrastim was discontinued by a pharmacist in 32% of
cases. A $22,416 cost saving was achieved in the first six months after protocol
implementation, with no compromise in clinical efficacy. A pharmacy-based
protocol for discontinuing filgrastim therapy in oncology patients saved a
community hospital more than $22,000 in the first six months withno adverse
impact on the drug's effectiveness.
PMID- 10683132
TI - Prevalence and treatment of heart failure in elderly long-term-care patients.
PMID- 10683133
TI - Impact of pharmacist interventions on hospital readmissions for heart failure.
PMID- 10683134
TI - Opportunities for pharmacy specialists as the delivery of health care changes.
PMID- 10683135
TI - Developing a care plan.
PMID- 10683136
TI - Clinical usefulness of urokinase after dilution and freezing.
PMID- 10683137
TI - Doxazosin-to-terazosin switch for benign prostatic hyperplasia.
PMID- 10683138
TI - Electronic prescriptions in pharmacy.
PMID- 10683139
TI - Bad medical writing as a barrier to communication.
PMID- 10683140
TI - Cross-regulation of the Wnt signalling pathway: a role of MAP kinases.
AB - The Wnt signal transduction pathway regulates various aspects of embryonal
development and is involved in cancer formation. Wnts induce the stabilisation of
cytosolic (beta)-catenin, which then associates with TCF transcription factors to
regulate expression of Wnt-target genes. At various levels the Wnt pathway is
subject to cross-regulation by other components. Recent evidence suggests that a
specific MAP kinase pathway involving the MAP kinase kinase kinase TAK1 and the
MAP kinase NLK counteract Wnt signalling. In particular, homologues of TAK1 and
NLK, MOM-4 and LIT-1, negatively regulate Wnt-controlled cell fate decision in
the early Caenorhabditis elegans embryo. Moreover, TAK1 activates NLK, which
phosphorylates TCFs bound to (beta)-catenin. This blocks nuclear localization and
DNA binding of TCFs. Since TAK1 is activated by TGF-(beta) and various cytokines,
it might provide an entry point for regulation of the Wnt system by other
pathways. In addition, alterations in TAK1-NLK might play a role in cancer.
PMID- 10683141
TI - The parting of the endothelium: miracle, or simply a junctional affair?
AB - Leukocyte extravasation from the blood across the endothelium is vital for the
functioning of the immune system. Our understanding of the early steps of this
process has developed rapidly. However, it is still unclear how leukocytes
undergo the final step, migrating through the junctions that mediate adhesion
between adjacent endothelial cells, while preserving the barrier function of the
endothelium. The first stage of transmigration - tethering and rolling - is
mediated by interactions between selectins on the surface of leukocytes and
glycosylated proteins such as GlyCAM-1 on the surface of endothelial cells.
Stimulation of the leukocyte by chemokines then induces tight adhesion, which
involves binding of activated leukocyte integrins to endothelial ICAM-1/VCAM-1
molecules. Passage of the leukocyte across the endothelium appears to require
delocalization of certain endothelial cell molecules and proteolytic degradation
of junctional complexes.
PMID- 10683142
TI - Ras-independent oncogenic transformation by an EGF-receptor mutant.
AB - Mutations in the ligand-binding domain of the epidermal growth factor receptor
have been identified in several types of human cancers, including malignant
gliomas. These mutations render signaling by this receptor to be constitutively
ligand-independent. In fibroblasts transformed with ligand-independent epidermal
growth factor receptor mutants, there is a correlation between the formation of a
unique phosphotyrosine protein complex and oncogenic transformation. This
phosphoprotein complex includes Grb2, Shc, Sos, tyrosine-phosphorylated form of
caldesmon, and two, as yet, unidentified proteins. The presence of Grb2, Shc, and
Sos in this complex implicates Ras in ligand-independent signaling by these
oncogenic epidermal growth factor receptor mutants. We, therefore, have used
retroviral co-infections of cultured primary fibroblasts to determine if Ras
activation is required for phosphoprotein complex formation, stress fiber loss,
or transformation. As predicted, expression of a dominant-negative Ras mutant
(N17Ras) completely abrogates ligand-stimulated soft agar colony growth of
primary fibroblasts. In contrast, N17Ras expression has no effect on v-ErbB
mediated stress fiber disassembly, soft agar colony growth, or phosphoprotein
complex assembly. In addition, our data suggest that ligand-dependent Ras
activation may be suppressed by oncogenic v-ErbB expression. Together these
observations suggest that oncogenic signaling by v-ErbB does not require Ras
activation, and implicate an alternative signal transduction pathway in ligand
independent epidermal growth factor receptor oncogenic signaling.
PMID- 10683143
TI - Reconstitution of microtubule nucleation potential in centrosomes isolated from
Spisula solidissima oocytes.
AB - Treatment of isolated Spisula solidissima centrosomes with KI removes (gamma)
tubulin, 25 nm rings, and their microtubule nucleation potential, revealing the
presence of a filamentous lattice, the 'centromatrix'. Treatment of this
centromatrix with Spisula oocyte extract results in the binding of (gamma)
tubulin and 25 nm rings, and the recovery of microtubule nucleation potential.
Fractionation of this extract resulted in the separation of elements that are
required for the recovery of microtubule nucleation potential. We show that some,
but not all, of the elements needed cosediment with microtubules. Further,
extracts prepared from activated (meiotic) and non-activated (interphase) Spisula
oocytes, CHO cells blocked in S phase, Drosophila embryos and Xenopus oocytes all
support the recovery of microtubule nucleation potential by the Spisula
centromatrix. These results demonstrate that components necessary for centrosome
dependent microtubule nucleation are functionally conserved and abundant in both
interphase and meiotic/mitotic cytoplasm.
PMID- 10683144
TI - DNA-binding activity of the N-terminal cleavage product of poly(ADP-ribose)
polymerase is required for UV mediated apoptosis.
AB - The role of the N-terminal cleavage product of poly(ADP-ribose) polymerase (PARP)
on UV mediated apoptosis was investigated in cultured HeLa cells. Ultrastructural
analysis of cells expressing caspase-resistant PARP (PARP(D214A)) revealed the
typical features of necrosis following UV treatment. However, cells co-expressing
PARP(D214A) with the N-terminal fragment of PARP containing the DNA-binding
domain underwent apoptosis instead of necrosis. In this study, we have
demonstrated that the DNA-binding activity of the N-terminal fragment of PARP is
important for the execution of apoptosis. Point mutations were introduced in the
DNA-binding sites of the N-terminal fragment. Cells co-expressing PARP(D214A)
with the mutated N-terminal fragments neither stimulated apoptosis nor prevented
necrosis in response to UV irradiation. The present study proposes that the DNA
binding activity of the N-terminal fragment of PARP in UV treated cells prevents
cellular ATP depletion, a mechanism by which necrotic cell death is triggered.
PMID- 10683145
TI - Formation of hemidesmosome-like structures in the absence of ligand binding by
the (alpha)6(beta)4 integrin requires binding of HD1/plectin to the cytoplasmic
domain of the (beta)4 integrin subunit.
AB - Hemidesmosomes are adhesion structures that mediate anchorage of epithelial cells
to the underlying basement membrane. We have previously shown that the
(alpha)6(beta)4 integrin can induce the assembly of these multi-protein
structures independent of binding to its ligand laminin-5 (ligand-independent
formation of hemidesmosomes). Our results suggested a role for HD1/plectin, which
binds to the cytoplasmic domain of the (beta)4 integrin subunit, in controlling
the clustering of hemidesmosomal components at the basal side of the cell. Using
keratinocytes derived from patients lacking HD1/plectin, we now show that ligand
independent formation of hemidesmosomal clusters indeed requires HD1/plectin, in
contrast to the ligand-dependent assembly of hemidesmosomes. No clustering of the
(alpha)6(beta)4 integrin, or of the bullous pemphigoid antigens BP180 and BP230,
was seen when HD1/plectin-deficient keratinocytes were plated on fibronectin or
type IV collagen. In (&bgr;)4-deficient keratinocytes, expression of an
interleukin 2 receptor (IL2R) transmembrane chimera containing the (beta)4
cytoplasmic tail with the mutation R1281W, which abrogates HD1/plectin binding,
resulted in a diffuse distribution of the chimeric receptor. In contrast, a
(beta)4(R1281W) mutant that can associate with (alpha)6 and bind ligand, was
found to be directed to the basal surface of the cells, at sites where laminin-5
was deposited. In addition, this mutant induced clustering of BP180 and BP230 at
these sites. Together, these results show that the formation of hemidesmosomes
requires binding of either ligand or HD1/plectin to the (beta)4 integrin subunit.
Intriguingly, we found that IL2R/(beta)4 chimeras become localized in pre
existing hemidesmosomes of HD1/plectin-deficient keratinocytes, and that this
localization requires a domain in the (beta)4 cytoplasmic tail that is also
required for HD1/plectin binding (residues 1115-1356). Because this part of
(beta)4 lacks the BP180 binding site, and since we show in this study that it is
unable to interact with the same part on another (beta)4 molecule, we suggest
that the chimera becomes incorporated into hemidesmosomes of HD1/plectin
deficient keratinocytes by interacting with an as yet unidentified hemidesmosomal
component.
PMID- 10683146
TI - p39 activates cdk5 in neurons, and is associated with the actin cytoskeleton.
AB - Cyclin-dependent kinase 5 (cdk5) is a small serine/threonine kinase that displays
close sequence homology to the mitotically active cyclin-dependent kinases. Cdk5
has been shown to play an essential role in the development of the nervous
system, including neuronal migration and neurite outgrowth. Cdk5 activation
requires the presence of a regulatory activator such as p35. cdk5 -/- mice have
much more extensive defects in the development of the nervous system than p35 -/-
mice, leading to the speculation that other regulatory activators of cdk5 exist.
Indeed, p39 is a p35 related protein isolated by sequence homology to p35. We
show here that p39 associates with cdk5 in brain lysates, and that this complex
is active in phosphorylation of histone H1. By extensive characterization of p39
subcellular localization in different cell types, we demonstrate the presence of
p39 in lamellipodial and fillopodial structures of cells and in growth cones of
neurons. We show that p39 colocalizes with actin, and cofractionates with the
detergent insoluble cytoskeleton from brain. Further, p39 coimmunoprecipitates
with actin in brain lysates. Finally, disruption of the actin cytoskeleton alters
p39 subcellular localization as well as kinase activity of the p39/cdk5 complex.
Therefore, our results reveal the existence of the p39/cdk5 complex in vivo and
suggest that it might play a role in regulating actin cytoskeletal dynamics in
cells.
PMID- 10683147
TI - Inhibiting cadherin function by dominant mutant E-cadherin expression increases
the extent of tight junction assembly.
AB - Previous studies have shown that induction of cadherin-mediated cell-cell
adhesion leads to tight junction formation, and that blocking cadherin-mediated
cell-cell adhesion inhibits tight junction assembly. Here we report analysis of
tight junction assembly in MDCK cells overexpressing a mutant E-cadherin protein
that lacks an adhesive extracellular domain (T151 cells). Mutant E-cadherin
overexpression caused a dramatic reduction in endogenous cadherin levels. Despite
this, tight junction assembly was extensive. The number of tight junction strands
observed by freeze-fracture electron microscopy significantly increased in T151
cells compared to that in control cells. Our data indicate that the hierarchical
regulation of junctional complex assembly is not absolute, and that inhibition of
cadherin function has both positive and negative effects on tight junction
assembly.
PMID- 10683148
TI - Preferential association of syntaxin 8 with the early endosome.
AB - Members of the syntaxin family play a fundamental role in vesicle docking and
fusion of diverse transport events. We have molecularly characterized syntaxin 8,
a novel member of the syntaxin family. The nucleotide sequence of cloned rat cDNA
predicts a polypeptide of 236 residues with a carboxyl-terminal 18-residue
hydrophobic domain that may function as a membrane anchor. Characteristic of
syntaxins, syntaxin 8 also contain regions that have the potential to form coiled
coil structures. Among the known syntaxins, syntaxin 8 is most homologous to
syntaxin 6 which is predominantly associated with the trans-Golgi network (TGN).
The syntaxin 8 transcript is detected in all rat tissues examined by northern
blot. Antibodies against recombinant syntaxin 8 recognize a 27 kDa protein that
is enriched in membrane fractions containing the Golgi apparatus and the
endosomal/lysosomal compartments. Syntaxin 8 in membrane extract could be
incorporated into a 20S protein complex in a way that is dependent on the soluble
N-ethylmaleimide-sensitive factor (NSF) and soluble NSF attachment protein
((alpha)-SNAP), suggesting that syntaxin 8 is indeed a SNAP receptor (SNARE).
Indirect immunofluorescence microscopy reveals that the majority of syntaxin 8 is
localized to the early endosome marked by Rab5. This is corroborated by
immunogold labeling experiments showing enrichment of syntaxin 8 in the early
endosome and its co-labeling with Rab5.
PMID- 10683149
TI - Interactions between Fc(epsilon)RI and lipid raft components are regulated by the
actin cytoskeleton.
AB - Previous studies showed that crosslinking of IgE-Fc(epsilon)RI complexes on RBL
2H3 mast cells causes their association with isolated detergent-resistant
membranes, also known as lipid rafts, in a cholesterol-dependent process that
precedes initiation of signaling by these receptors. To investigate these
interactions on intact cells, we examined the co-redistribution of raft
components with crosslinked IgE-Fc(epsilon)RI using confocal microscopy. After
several hours of crosslinking at 4 degrees C, the glycosylphosphatidylinositol
linked protein Thy-1 and the Src-family tyrosine kinase Lyn co-redistribute with
IgE-Fc(epsilon)RI in large patches at the plasma membrane. Under these
conditions, F-actin also undergoes dramatic co-segregation with Fc(epsilon)RI and
raft components but is dispersed following a brief warm-up to 37 degrees C. When
crosslinking of IgE-Fc(epsilon)RI is initiated at higher temperatures, co
redistribution of raft components with patched Fc(epsilon)RI is not readily
detected unless stimulated F-actin polymerization is inhibited by cytochalasin D.
In parallel, cytochalasin D converts transient antigen-stimulated tyrosine
phosphorylation to a more sustained response. Sucrose gradient analysis of lysed
cells reveals that crosslinked IgE-Fc(epsilon)RI remains associated with lipid
rafts throughout the time course of the transient phosphorylation response but
undergoes a time-dependent shift to higher density that is prevented by
cytochalasin D. Our results indicate that interactions between Lyn and
crosslinked IgE-Fc(epsilon)RI are regulated by stimulated F-actin polymerization,
and this is best explained by a segregation of anchored raft components from more
mobile ones.
PMID- 10683150
TI - Endo180, an endocytic recycling glycoprotein related to the macrophage mannose
receptor is expressed on fibroblasts, endothelial cells and macrophages and
functions as a lectin receptor.
AB - Endo180 was previously characterized as a novel, cell type specific, recycling
transmembrane glycoprotein. This manuscript describes the isolation of a full
length human Endo180 cDNA clone which was shown to encode a fourth member of a
family of proteins comprising the macrophage mannose receptor, the phospholipase
A(2) receptor and the DEC-205/MR6 receptor. This receptor family is unusual in
that they contain 8-10 C-type lectin carbohydrate recognition domains in a single
polypeptide backbone, however, only the macrophage mannose receptor had been
shown to function as a lectin. Sequence analysis of Endo180 reveals that the
second carbohydrate recognition domain has retained key conserved amino acids
found in other functional C-type lectins. Furthermore, it is demonstrated that
this protein displays Ca(2+)-dependent binding to N-acetylglucosamine but not
mannose affinity columns. In order to characterize the physiological function of
Endo180, a series of biochemical and morphological studies were undertaken.
Endo180 is found to be predominantly expressed in vivo and in vitro on
fibroblasts, endothelial cells and macrophages, and the distribution and post
translational processing in these cells is consistent with Endo180 functioning to
internalize glycosylated ligands from the extracellular milieu for release in an
endosomal compartment.
PMID- 10683151
TI - Evidence for the coincident initiation of homolog pairing and synapsis during the
telomere-clustering (bouquet) stage of meiotic prophase.
AB - To improve knowledge of the prerequisites for meiotic chromosome segregation in
higher eukaryotes, we analyzed the spatial distribution of a pair of homologs
before and during early meiotic prophase. Three-dimensional images of
fluorescence in situ hybridization (FISH) were used to localize a single pair of
homologs in diploid nuclei of a chromosome-addition line of oat, oat-maize9b. The
system provided a robust assay for pairing based on cytological colocalization of
FISH signals. Using a triple labeling scheme for simultaneous imaging of
chromatin, telomeres and the homolog pair, we determined the timing of pairing in
relation to the onset of three sequential hallmarks of early meiotic prophase:
chromatin condensation (the leptotene stage), meiotic telomere clustering (the
bouquet stage) and the initiation of synapsis (the zygotene stage). We found that
the two homologs were mostly unpaired up through middle leptotene, at which point
their spherical cloud-like domains began to transform into elongated and
stretched-out domains. At late leptotene, the homologs had completely reorganized
into long extended fibers, and the beginning of the bouquet stage was
conspicuously marked by the de novo clustering of telomeres at the nuclear
periphery. The homologs paired and synapsed during the bouquet stage, consistent
with the timing of pairing observed for several oat 5S rDNA loci. In summary,
results from analysis of more than 100 intact nuclei lead us to conclude that
pairing and synapsis of homologous chromosomes are largely coincident processes,
ruling out a role for premeiotic pairing in this system. These findings suggest
that the genome-wide remodeling of chromatin and telomere-mediated nuclear
reorganization are prerequisite steps to the DNA sequence-based homology-search
process in higher eukaryotes.
PMID- 10683152
TI - The transmembrane protein p23 contributes to the organization of the Golgi
apparatus.
AB - In previous studies we have shown that p23, a member of the p24-family of small
transmembrane proteins, is highly abundant in membranes of the cis-Golgi network
(CGN), and is involved in sorting/trafficking in the early secretory pathway. In
the present study, we have further investigated the role of p23 after ectopic
expression. We found that ectopically expressed p23 folded and oligomerized
properly, even after overexpression. However, in contrast to endogenous p23,
exogenous p23 molecules did not localize to the CGN, but induced a significant
expansion of characteristic smooth ER membranes, where they accumulated in high
amounts. This ER-derived, p23-rich subdomain displayed a highly regular
morphology, consisting of tubules and/or cisternae of constant diameter, which
were reminiscent of the CGN membranes containing p23 in control cells. The
expression of exogenous p23 also led to the specific relocalization of endogenous
p23, but not of other proteins, to these specialized ER-derived membranes.
Relocalization of p23 modified the ultrastructure of the CGN and Golgi membranes,
but did not affect anterograde and retrograde transport reactions to any
significant extent. We conclude (i) that p23 has a morphogenic activity that
contributes to the morphology of CGN-membranes; and (ii) that the presence of p23
in the CGN is necessary for the proper organization of the Golgi apparatus.
PMID- 10683153
TI - Brain-derived neurotrophic factor-induced phosphorylation of neurofilament-H
subunit in primary cultures of embryo rat cortical neurons.
AB - Phosphorylation of the neurofilament-H subunit (NF-H) was investigated in rat
embryonic brain neurons in culture. A portion of the NF-H was phosphorylated in
vivo at embryonic day 17 when brain neurons were prepared. When the neurons were
isolated and cultured, the NF proteins disappeared once and then reappeared over
the next several days in the following order: (1) NF-L/NF-M, (2) dephosphorylated
NF-H and (3) phosphorylated NF-H. Phosphorylation of NF-H began around 4 days
after cell plating, at about the time of synapse formation. Treatments that
appeared to modulate the timing of synapse formation also affected the timing of
NF-H phosphorylation: (1) earlier phosphorylation was observed at higher neuronal
cell density, (2) earlier phosphorylation was observed in neurons cultured on a
coating substrate that promotes rapid neurite extension and (3) phosphorylation
was suppressed when neurite extension was inhibited by brefeldin A. Three
possible synapse formation-induced events, excitation, cell-cell contact through
adhesion proteins and elevated concentrations of neurotrophic factors, were
examined for their possible involvement in generating the signal for NF-H
phosphorylation. Neither excitation nor cell contact enhanced NF-H
phosphorylation. Neurotrophic factors, brain-derived neurotrophic factor (BDNF)
and neurotrophin 3 (NT3) stimulated phosphorylation of NF-H. The BDNF-stimulated
phosphorylation was inhibited by an anti-BDNF antibody and K252a, an inhibitor of
BDNF receptor TrkB tyrosine kinase. Among known NF-H kinases of cyclin-dependent
kinase 5 (CDK5), external signal-regulated protein kinase (ERK) and stress
activated protein kinase (SAPK), CDK5 and SAPK showed an increase in kinase
activity or an active form with a time course similar to NF-H phosphorylation in
control culture. On the other hand, BDNF stimulated the kinase activity of CDK5
and induced appearance of an active form of ERK transiently. These results
suggest a possibility that synapse formation induces NF-H phosphorylation, at
least in part, through activation of CDK5 by BDNF.
PMID- 10683154
TI - Evidence for deterministic chaos in aperiodic oscillations of proliferative
activity in long-term cultured Fao hepatoma cells.
AB - The proliferative activity of long-term cultured mammalian cells exhibits traits
of a complex dynamic system, with a succession of spontaneous rises and falls in
proliferation rate. We analyzed three successive series of proliferation data for
the Fao hepatoma cell line in long-term cultures. In the three series the
proliferation rate displayed apparently disordered oscillations, which each
lasted about 3-5 passages, with variable amplitude and were therefore
unpredictable. Such non-linear kinetics raises the major issue of whether these
fluctuations are random, or determined and coordinated. We used a graphical
method of analysis of the data, which demonstrated that all troughs of
proliferation were mathematically related to a common value in each series. This
common value was itself related to the maximum level of proliferation of the cell
line. Non-linear analysis thus confirmed that the fluctuations in proliferation
rate of tumoral Fao cells are, at least in part, determined. This pattern evokes
chaotic dynamics and is evidence for the flexible coordination of the complex
system linking positive and negative growth regulators in long-term cultured
cells.
PMID- 10683155
TI - A novel mutant allele of the chromatin-bound fission yeast checkpoint protein
Rad17 separates the DNA structure checkpoints.
AB - To further dissect the genetic differences between the checkpoint pathway
following S-phase cdc arrest versus DNA damage, a genetic screen was performed
for checkpoint mutants that were unable to arrest mitosis following cell-cycle
arrest with a temperature-sensitive DNA polymerase delta mutant, cdc20-M10. One
such checkpoint mutant, rad17-d14, was found to display the cut phenotype
following S-phase arrest by cdc20-M10, but not by the DNA synthesis inhibitor
hydroxyurea, reminiscent of the chk1 mutant. Unlike chk1 , rad17-d14 was not
sensitive to UV irradiation. Interestingly, the ionising radiation sensitivity of
rad17-d14 was only at higher doses, and cells were found to be defective in
properly arresting cell division following irradiation in S phase, but not G(2)
phase. Biochemical analysis attributes the checkpoint defects of rad17-d14 to the
failure to phosphorylate the checkpoint effector Chk1p. To investigate if Rad17p
monitors the genome for abnormal DNA structures specifically during DNA
synthesis, chromatin association of Rad17p was analysed. Rad17p was found to be
chromatin associated throughout the cell cycle, not just during S phase. This
interaction occurred irrespective of the arrest with cdc20-M10 and, surprisingly,
was also independent of the other checkpoint Rad proteins, and the cell-cycle
effectors Chk1p and Cds1p.
PMID- 10683156
TI - Mammalian S-phase checkpoint integrity is dependent on transformation status and
purine deoxyribonucleosides.
AB - In eukaryotic cells arrested in S-phase, checkpoint controls normally restrain
mitosis until after replication. We have identified an array of previously
unsuspected factors that modulate this restraint, using transformed hamster cells
in which cycle controls are known to be altered in S-phase arrest. Arrested cells
accumulate cyclin B, the regulatory partner of the mitotic p34(cdc2) kinase,
which is normally not abundant until late G(2) phase; treatment of arrested cells
with caffeine produces rapid S-phase condensation. We show here that such S-phase
checkpoint slippage, as visualised through caffeine-dependent S-phase
condensation, correlates with rodent origin and transformed status, is opposed by
reverse transformation, and is favoured by c-src and opposed by wnt1
overexpression. Slippage is also dependent on a prolonged replicative arrest, and
is favoured by arrest with hydroxyurea, which inhibits ribonucleotide reductase.
This last is a key enzyme in deoxyribonucleotide synthesis, recently identified
as a determinant of malignancy. Addition of deoxyribonucleosides shows that rapid
S-phase condensation is suppressed by a novel checkpoint mechanism: purine (but
not pyrimidine) deoxyribonucleosides, like reverse transformation, suppress
cyclin B/p34(cdc2) activation by caffeine, but not cyclin B accumulation. Thus,
ribonucleotide reductase has an unexpectedly complex role in mammalian cell cycle
regulation: not only is it regulated in response to cycle progression, but its
products can also reciprocally influence cell cycle control kinase activation.
PMID- 10683157
TI - Analysis of the three-dimensional trajectories of organisms: estimates of
velocity, curvature and torsion from positional information.
AB - Most biological motions are three-dimensional. This includes the trajectories of
whole organisms and of their appendages. While recordings of three-dimensional
trajectories are sometimes published, quantitative analysis of these trajectories
is uncommon, primarily because there are no standard techniques or conventions in
biology for the analysis of three-dimensional trajectories. This paper describes
a new technique, finite helix fit (FHF), based on the geometry of three
dimensional curves, whereby a three-dimensional trajectory is completely
described by its velocity, curvature and torsion. FHF estimates these parameters
from discretely sampled points on a trajectory (i.e. from positional data such as
x,y,z coordinates). Other measures of motion can be derived from these
parameters, such as the translational and rotational (or angular) velocities of
an organism. The performance of the algorithms is demonstrated using simulated
trajectories and trajectories of freely swimming organisms (a flagellate,
Chlamydomonas reinhardtii; a ciliate, Paramecium tetraurelia; spermatozoa of a
sea urchin, Arbacia punctulata; larvae of an ascidian, Botrylloides sp.).
PMID- 10683158
TI - Directional hearing of a grasshopper in the field.
AB - An electrophysiological method for making long-term recordings from the tympanal
nerve was developed in Chorthippus biguttulus (Gomphocerinae) to gain insight
into the ecophysiological constraints of sound localization in acridid
grasshoppers. Using this 'biological microphone', the directional dependence of
auditory nerve activity was monitored both in the laboratory and in various
natural habitats of this species. On gravel and in sparse vegetation, the overall
patterns of directionality were found to be very similar to those in the free
sound field in the laboratory, regardless of whether the animal was positioned
horizontally or vertically. However, the differences between the ipsi- and
contralateral sides were smaller in these habitats than in the laboratory. In
dense vegetation, the directional patterns were greatly affected by the
environment. Moreover, a minimum in nerve activity was not always reached on the
contralateral side, as is typical for the free sound field situation. On the
basis of these data, predictions can be made about the ability of the animals to
determine the correct side of a sound source. In the free sound field of the
laboratory, correct lateralizations are expected at all angles of sound incidence
between 20 and 160 degrees, a prediction corresponding to the results of
behavioural studies. In sparse vegetation, a similar accuracy can be anticipated,
whereas on gravel and in dense vegetation directional hearing is expected to be
severely degraded, especially if the animal is oriented horizontally. The
predictions from our present electrophysiological investigations must now be
confirmed by behavioural studies in the field.
PMID- 10683159
TI - Lack of effect of ageing on acetate oxidation in rat skeletal muscle during
starvation: a (13)C NMR study.
AB - Acetate oxidation was examined by (13)C nuclear magnetic resonance in skeletal
muscle from adult and old rats. Rats fasted for 5 days were perfused with [2
(13)C]acetate over 2 h, and muscle extracts were analyzed for [(13)C]glutamate
isotopomers. This study shows that approximately 80 % of acetyl-coenzyme A
entering the tricarboxylic cycle was derived from substrate infusion in both
adult and old rats, and that the flux through anaplerotic pathways was
approximately 21 % of the flux through citrate synthase. These data demonstrate
that skeletal muscle from adult and old rats oxidizes the same proportion of
exogenous acetate.
PMID- 10683160
TI - The ontogeny of metabolic rate and thermoregulatory capabilities of northern fur
seal, Callorhinus ursinus, pups in air and water.
AB - Young pinnipeds, born on land, must eventually enter the water to feed
independently. The aim of this study was to examine developmental factors that
might influence this transition. The ontogeny of metabolic rate and
thermoregulation in northern fur seal, Callorhinus ursinus, pups was investigated
at two developmental stages in air and water using open-circuit respirometry.
Mean in-air resting metabolic rate (RMR) increased significantly from 113+/-5 ml
O(2 )min(-)(1) (N=18) pre-molt to 160+/-4 ml O(2 )min(-)(1) (N=16; means +/-
s.e.m.) post-molt. In-water, whole-body metabolic rates did not differ pre- and
post-molt and were 2.6 and 1.6 times in-air RMRs respectively. Mass-specific
metabolic rates of pre-molt pups in water were 2.8 times in-air rates. Mean mass
specific metabolic rates of post-molt pups at 20 degrees C in water and air did
not differ (16.1+/-1.7 ml O(2 )min(-)(1 )kg(-)(1); N=10). In-air mass-specific
metabolic rates of post-molt pups were significantly lower than in-water rates at
5 degrees C (18.2+/-1.1 ml O(2 )min(-)(1 )kg(-)(1); N=10) and 10 degrees C
(19.4+/-1.7 ml O(2 )min(-)(1 )kg(-)(1); N=10; means +/- s.e.m.). Northern fur
seal pups have metabolic rates comparable with those of terrestrial mammalian
young of similar body size. Thermal conductance was independent of air
temperature, but increased with water temperature. In-water thermal conductance
of pre-molt pups was approximately twice that of post-molt pups. In-water pre
molt pups matched the energy expenditure of larger post-molt pups while still
failing to maintain body temperature. Pre-molt pups experience greater relative
costs when entering the water regardless of temperature than do larger post-molt
pups. This study demonstrates that the development of thermoregulatory
capabilities plays a significant role in determining when northern fur seal pups
enter the water.
PMID- 10683161
TI - Thermotolerant desert lizards characteristically differ in terms of heat-shock
system regulation.
AB - We compare the properties and activation of heat-shock transcription factor
(HSF1) and the synthesis of a major family of heat-shock proteins (HSP70) in
lizard species inhabiting ecological niches with strikingly different thermal
parameters. Under normal non-heat-shock conditions, all desert-dwelling lizard
species studied so far differ from a northern, non-desert species (Lacerta
vivipara) in the electrophoretic mobility and content of proteins constitutively
bound to the regulatory heat-shock elements in the heat-shock gene promoter.
Under these conditions, levels of activated HSF1 and of both HSP70 mRNA and
protein are higher in the desert species than in the non-desert species. Upon
heat shock, HSF1 aggregates in all species studied, although in desert species
HSF1 subsequently disaggregates more rapidly. Cells of the northern species have
a lower thermal threshold for HSP expression than those of the desert species,
which correlates with the relatively low constitutive level of HSPs and high
basal content of HSF1 in their cells.
PMID- 10683162
TI - Differential branchial and renal handling of urea, acetamide and thiourea in the
gulf toadfish Opsanus beta: evidence for two transporters.
AB - The possible presence of a urea transporter in the kidney of the gulf toadfish
(Opsanus beta) and further characterization of the pulsatile facilitated
transporter previously identified in its gills were investigated by comparing the
extra-renal and renal handling of two urea analogues with the handling of urea.
Toadfish were fitted with caudal artery and indwelling urinary ureteral catheters
and injected with an iso-osmotic dose of (14)C-labelled urea analogue (acetamide
or thiourea) calculated to bring plasma analogue concentrations close to plasma
urea concentrations. Branchial permeabilities to urea, acetamide and thiourea
were similar during non-pulsing periods and all increased during pulse events,
although urea permeability was greater than analogue permeability during pulses.
The incidence and magnitude of acetamide and urea pulses at the gills were
significantly correlated, acetamide pulses being 35-50 % of the size of urea
pulses. However, the thiourea and urea pulses at the gills were only weakly
correlated, thiourea pulses being less than 16 % of the size of urea pulses.
Thiourea inhibited branchial urea excretion by reducing the pulse frequency. The
renal handling of thiourea and urea were similar in that both substances were
more concentrated in the urine than in the plasma, whereas acetamide was found in
equal concentrations in the urine and plasma. Urea and thiourea were secreted 2-3
times more effectively than Cl(-) and water, whereas acetamide was secreted at a
similar relative rate. The differential handling of the urea analogues by the
gills and kidney indicates the presence of a different, possibly unique,
transporter in the kidney. The movement of thiourea and urea into the renal
tubule against an apparent concentration gradient suggests the presence of an
active transport mechanism.
PMID- 10683163
TI - The effects of cell ageing on metabolism in rainbow trout (Oncorhynchus mykiss)
red blood cells.
AB - The effects of cell age on metabolism in the nucleated red blood cells of rainbow
trout (Oncorhynchus mykiss) were examined. Red blood cells were separated
according to age using fixed-angle centrifugation. The mean erythrocyte
haemoglobin concentration in old red blood cells was found to be 120 % of that in
young red blood cells. In young red blood cells, the activities of the
mitochondrial enzymes citrate synthase and cytochrome oxidase were 135-200 %,
respectively, of those measured in old red blood cells. The activity of the
glycolytic enzyme lactate dehydrogenase in young red blood cells was 170 % of
that in old red blood cells, whereas the activity of the glycolytic enzyme
pyruvate kinase was not significantly affected by cell age. In addition, young
red blood cells consumed over twice as much O(2) and devoted 50 % more O(2) to
protein synthesis and the activity of Na(+)/K(+)-ATPase than old red blood cells.
Red blood cell age did not significantly affect the rate of lactate production.
This study shows that ageing in rainbow trout nucleated red blood cells is
accompanied by a significant decline in aerobic energy production and the
processes it supports, as well as a corresponding increase in the glycolytic
contribution to metabolism.
PMID- 10683164
TI - Sulphaemoglobin formation in fish: a comparison between the haemoglobin of the
sulphide-sensitive rainbow trout (Oncorhynchus Mykiss) and of the sulphide
tolerant common carp (Cyprinus Carpio).
AB - A method for the quantitative determination of sulphaemoglobin (SHb) in a mixture
of haemoglobin derivatives by spectral deconvolution is described. SHb formation
was studied in haemolysates and in red blood cells of the sulphide-sensitive
rainbow trout (Oncorhynchus mykiss) and of the sulphide-tolerant common carp
(Cyprinus carpio). Addition of sulphide caused the formation of SHb in
haemolysates of both animals. However, haemoglobin from common carp was much less
sensitive to sulphide than was trout haemoglobin. The maximal obtainable SHb
fraction was approximately 30 % in trout and 10 % in carp haemolysates. In both
animals, the SHb fraction increased with increasing Hb and sulphide
concentrations up to 100 micromol l(-)(1) and 1 mmol l(-)(1), respectively, and
was favoured by a low pH. An increase of temperature between 5 and 25 degrees C
strongly increased SHb formation in trout haemolysate. In contrast, temperature
changes had almost no effect on SHb production in carp. Within trout red blood
cells, approximately 7 % of total haemoglobin was converted to SHb during 60 min
of incubation (with 2.5 mmol l(-)(1) sulphide), inducing a 20 % loss of
haemoglobin oxygen-saturation. In carp red blood cells incubated under identical
conditions, SHb formation was minimal and haemoglobin oxygen-saturation was not
affected.
PMID- 10683165
TI - Physical and physiological components of the graviresponses of wild-type and
mutant Paramecium Tetraurelia.
AB - Wild-type and the morphological mutant kin 241 of Paramecium tetraurelia showed
improved orientation away from the centre of gravity (negative gravitaxis) when
accelerations were increased from 1 to 7 g. Gravitaxis was more pronounced in the
mutant. A correlation between the efficiency of orientation and the applied g
value suggests a physical basis for gravitaxis. Transiently enhanced rates of
reversal of the swimming direction coincided with transiently enhanced gravitaxis
because reversals occurred more often in downward swimmers than in upward
swimmers. The results provide evidence of a physiological modulation of
gravitaxis by means of the randomizing effect of depolarization-dependent
swimming reversals. Gravity bimodally altered propulsion rates of wild-type P.
tetraurelia so that sedimentation was partly antagonized in upward and downward
swimmers (negative gravikinesis). In the mutant, only increases in propulsion
were observed, although the orientation-dependent sensitivity of the gravikinetic
response was the same as in the wild-type population. Observed swimming speed and
sedimentation rates in the wild-type and mutant cells were linearly related to
acceleration, allowing the determination of gravikinesis as a linear (and so far
non-saturating) function of gravity.
PMID- 10683166
TI - A conserved location for the central nervous system control of mating behaviour
in gastropod molluscs: evidence from a terrestrial snail.
AB - We have investigated the role of the right mesocerebrum in the expression of
mating behaviour in the garden snail Helix aspersa. Using an in vivo stimulation
and recording technique, we provide evidence for both sensory and motor functions
in the mesocerebral neuronal population. Some neurones were specifically
sensitive to tactile stimuli delivered to the skin on the superior tentacles and
around the genital pore. Electrical stimulation of the right mesocerebrum evoked
genital eversion and, in combination with tactile stimulation, dart-shooting and
penial eversion. Genital eversions were also elicited by injections of APGWamide.
During courtship, one recorded unit increased its activity only in correlation
with penial eversion, while six other units increased their activity only during
dart-shooting. Three additional units increased their activity during both types
of behaviour. In addition, most of the recorded units showed increased neuronal
activity during times of contact with a partner. Comparison of our results with
available data from other molluscs leads us to conclude that the right
anteromedial region of the cerebral ganglion is an evolutionarily conserved
region of the gastropod brain specialised for the control of male mating
behaviour. It is striking to find such functional conservation in the central
nervous system of phylogenetically distant gastropods given the large differences
in behaviour during mating.
PMID- 10683167
TI - Mechanics of lung ventilation in a post-metamorphic salamander, Ambystoma
Tigrinum.
AB - The mechanics of lung ventilation in frogs and aquatic salamanders has been well
characterized, whereas lung ventilation in terrestrial-phase (post-metamorphic)
salamanders has received little attention. We used electromyography (EMG), X-ray
videography, standard videography and buccal and body cavity pressure
measurements to characterize the ventilation mechanics of adult (post
metamorphic) tiger salamanders (Ambystoma tigrinum). Three results emerged: (i)
under terrestrial conditions or when floating at the surface of the water, adult
A. tigrinum breathed through their nares using a two-stroke buccal pump; (ii) in
addition to this narial two-stroke pump, adult tiger salamanders also gulped air
in through their mouths using a modified two-stroke buccal pump when in an
aquatic environment; and (iii) exhalation in adult tiger salamanders is active
during aquatic gulping breaths, whereas exhalation appears to be passive during
terrestrial breathing at rest. Active exhalation in aquatic breaths is indicated
by an increase in body cavity pressure during exhalation and associated EMG
activity in the lateral hypaxial musculature, particularly the M. transversus
abdominis. In terrestrial breathing, no EMG activity in the lateral hypaxial
muscles is generally present, and body cavity pressure decreases during
exhalation. In aquatic breaths, tidal volume is larger than in terrestrial
breaths, and breathing frequency is much lower (approximately 1 breath 10 min(
)(1 )versus 4-6 breaths min(-)(1)). The use of hypaxial muscles to power active
exhalation in the aquatic environment may result from the need for more complete
exhalation and larger tidal volumes when breathing infrequently. This hypothesis
is supported by previous findings that terrestrial frogs ventilate their lungs
with small tidal volumes and exhale passively, whereas aquatic frogs and
salamanders use large tidal volumes and and exhale actively.
PMID- 10683168
TI - The electrical properties of the anterior stomach of the larval mosquito (Aedes
aegypti).
AB - The electrical properties of the anterior stomach of the larval mosquito (Aedes
aegypti) were determined. At late times after cannulation, the intraluminal space
constant was 936 microm, which is almost as long as the isolated tissue itself.
At this time, the resistance of the apical cell membranes dominates the
transcellular resistance; it is approximately 14 times the resistance of the
basal cell membrane. Two physiologically distinct epithelial cell types were
identified. One type has a stable basal potential of approximately 65 mV and
responds to 5-hydroxytryptamine with hyperpolarization. The second cell type
initially shows a basal potential of 100 mV. However, this basal potential decays
in the first few minutes in parallel with the decay of the transintestinal
potential. This latter cell type does not respond to 5-hydroxytryptamine.
PMID- 10683169
TI - The RXR ortholog USP suppresses early metamorphic processes in Drosophila in the
absence of ecdysteroids.
AB - The steroid hormone 20-hydroxyecdysone (20E) initiates metamorphosis in insects
by signaling through the ecdysone receptor complex, a heterodimer of the ecdysone
receptor (EcR) and ultraspiracle (USP). Analysis of usp mutant clones in the wing
disc of Drosophila shows that in the absence of USP, early hormone responsive
genes such as EcR, DHR3 and E75B fail to up-regulate in response to 20E, but
other genes that are normally expressed later, such as (&bgr;)-Ftz-F1 and the Z1
isoform of the Broad-Complex (BRC-Z1), are expressed precociously. Sensory neuron
formation and axonal outgrowth, two early metamorphic events, also occur
prematurely. In vitro experiments with cultured wing discs showed that BRC-Z1
expression and early metamorphic development are rendered steroid-independent in
the usp mutant clones. These results are consistent with a model in which these
latter processes are induced by a signal arising during the middle of the last
larval stage but suppressed by the unliganded EcR/USP complex. Our observations
suggest that silencing by the unliganded EcR/USP receptor and the subsequent
release of silencing by moderate steroid levels may play an important role in
coordinating early phases of steroid driven development.
PMID- 10683170
TI - In ovo time-lapse analysis of chick hindbrain neural crest cell migration shows
cell interactions during migration to the branchial arches.
AB - Hindbrain neural crest cells were labeled with DiI and followed in ovo using a
new approach for long-term time-lapse confocal microscopy. In ovo imaging allowed
us to visualize neural crest cell migration 2-3 times longer than in whole embryo
explant cultures, providing a more complete picture of the dynamics of cell
migration from emergence at the dorsal midline to entry into the branchial
arches. There were aspects of the in ovo neural crest cell migration patterning
which were new and different. Surprisingly, there was contact between neural
crest cell migration streams bound for different branchial arches. This cell-cell
contact occurred in the region lateral to the otic vesicle, where neural crest
cells within the distinct streams diverted from their migration pathways into the
branchial arches and instead migrated around the otic vesicle to establish a
contact between streams. Some individual neural crest cells did appear to cross
between the streams, but there was no widespread mixing. Analysis of individual
cell trajectories showed that neural crest cells emerge from all rhombomeres (r)
and sort into distinct exiting streams adjacent to the even-numbered rhombomeres.
Neural crest cell migration behaviors resembled the wide diversity seen in whole
embryo chick explants, including chain-like cell arrangements; however, average
in ovo cell speeds are as much as 70% faster. To test to what extent neural crest
cells from adjoining rhombomeres mix along migration routes and within the
branchial arches, separate groups of premigratory neural crest cells were labeled
with DiI or DiD. Results showed that r6 and r7 neural crest cells migrated to the
same spatial location within the fourth branchial arch. The diversity of
migration behaviors suggests that no single mechanism guides in ovo hindbrain
neural crest cell migration into the branchial arches. The cell-cell contact
between migration streams and the co-localization of neural crest cells from
adjoining rhombomeres within a single branchial arch support the notion that the
pattern of hindbrain neural crest cell migration emerges dynamically with cell
cell communication playing an important guidance role.
PMID- 10683172
TI - Autoregulation and multiple enhancers control Math1 expression in the developing
nervous system.
AB - Development of the vertebrate nervous system requires the actions of
transcription factors that establish regional domains of gene expression, which
results in the generation of diverse neuronal cell types. MATH1, a transcription
factor of the bHLH class, is expressed during development of the nervous system
in multiple neuronal domains, including the dorsal neural tube, the EGL of the
cerebellum and the hair cells of the vestibular and auditory systems. MATH1 is
essential for proper development of the granular layer of the cerebellum and the
hair cells of the cochlear and vestibular systems, as shown in mice carrying a
targeted disruption of Math1. Previously, we showed that 21 kb of sequence
flanking the Math1-coding region is sufficient for Math1 expression in transgenic
mice. Here we identify two discrete sequences within the 21 kb region that are
conserved between mouse and human, and are sufficient for driving a lacZ reporter
gene in these domains of Math1 expression in transgenic mice. The two identified
enhancers, while dissimilar in sequence, appear to have redundant activities in
the different Math1 expression domains except the spinal neural tube. The
regulatory mechanisms for each of the diverse Math1 expression domains are
tightly linked, as separable regulatory elements for any given domain of Math1
expression were not found, suggesting that a common regulatory mechanism controls
these apparently unrelated domains of expression. In addition, we demonstrate a
role for autoregulation in controlling the activity of the Math1 enhancer,
through an essential E-box consensus binding site.
PMID- 10683171
TI - Endodermal Nodal-related signals and mesoderm induction in Xenopus.
AB - In Xenopus, mesoderm induction by endoderm at the blastula stage is well
documented, but the molecular nature of the endogenous inductive signals remains
unknown. The carboxy-terminal fragment of Cerberus, designated Cer-S, provides a
specific secreted antagonist of mesoderm-inducing Xenopus Nodal-Related (Xnr)
factors. Cer-S does not inhibit signalling by other mesoderm inducers such as
Activin, Derriere, Vg1 and BMP4, nor by the neural inducer Xnr3. In the present
study we show that Cer-S blocks the induction of both dorsal and ventral mesoderm
in animal-vegetal Nieuwkoop-type recombinants. During blastula stages Xnr1, Xnr2
and Xnr4 are expressed in a dorsal to ventral gradient in endodermal cells. Dose
response experiments using cer-S mRNA injections support the existence of an
endogenous activity gradient of Xnrs. Xnr expression at blastula can be activated
by the vegetal determinants VegT and Vg1 acting in synergy with dorsal (beta)
catenin. The data support a modified model for mesoderm induction in Xenopus, in
which mesoderm induction is mediated by a gradient of multiple Nodal-related
signals released by endoderm at the blastula stage.
PMID- 10683173
TI - Fragile skeletal muscle attachments in dystrophic mutants of Caenorhabditis
elegans: isolation and characterization of the mua genes.
AB - Over 30 Caenorhabditis elegans mutants were identified with normal muscle
differentiation and initial locomotion followed by catastrophic detachment of
skeletal muscles from the body wall. Reducing the strength of muscle contraction
in these mutants with a myosin gene mutation suppresses muscle detachment. These
dystrophic mutants identify a novel class of genes required for growth and
maintenance of functional muscle attachments, not exceptional alleles of genes
required for muscle differentiation and contractility. Nine new genes, named mua,
and two previously published loci, unc-23 and vab-10, cause fragile musscle
attachments. The primary sites of muscle detachment, including the plane of
tissue separation, are characteristic for each gene. We suggest these genes
identify feedback mechanisms whereby local strain regulates the extent of
myofibril contraction and the placement of new muscle attachments in functioning
muscles. Finally, we draw some comparisons to vertebrate skin fragility diseases
and muscular dystrophies.
PMID- 10683174
TI - Dorsal and intermediate neuronal cell types of the spinal cord are established by
a BMP signaling pathway.
AB - We have studied the role of Bmp signaling in patterning neural tissue through the
use of mutants in the zebrafish that disrupt three different components of a Bmp
signaling pathway: swirl/bmp2b, snailhouse/bmp7 and somitabun/smad5. We
demonstrate that Bmp signaling is essential for the establishment of the
prospective neural crest and dorsal sensory Rohon-Beard neurons of the spinal
cord. Moreover, Bmp signaling is necessary to limit the number of intermediate
positioned lim1+ interneurons of the spinal cord, as observed by the dramatic
expansion of these prospective interneurons in many mutant embryos. Our analysis
also suggests a positive role for Bmp signaling in the specification of these
interneurons, which is independent of Bmp2b/Swirl activity. We found that a
presumptive ventral signal, Hh signaling, acts to restrict the amount of dorsal
sensory neurons and trunk neural crest. This restriction appears to occur very
early in neural tissue development, likely prior to notochord or floor plate
formation. A similar early role for Bmp signaling is suggested in the
specification of dorsal neural cell types, since the bmp2b/swirl and
bmp7/snailhouse genes are only coexpressed during gastrulation and within the
tail bud, and are not found in the dorsal neural tube or overlying epidermal
ectoderm. Thus, a gastrula Bmp2b/Swirl and Bmp7/Snailhouse-dependent activity
gradient may not only act in the specification of the embryonic dorsoventral
axis, but may also function in establishing dorsal and intermediate neuronal cell
types of the spinal cord.
PMID- 10683175
TI - Regulation of the early expression of the Xenopus nodal-related 1 gene, Xnr1.
AB - The Xenopus nodal related-1 (Xnr1) gene has a complex expression pattern in
embryos, with two temporal phases. In the first phase, transcripts are first
detected in perinuclear sites in the vegetal region of the blastula. During
gastrulation, this expression disappears and transcripts become localised to the
dorsal marginal zone. Expression stops and then restarts in a second phase at
neurula and tailbud stages, firstly in two symmetric patches near the posterior
end of the notochord, and then asymmetrically in a large domain in the left
lateral plate mesoderm. In this study, we have investigated the regulation of the
early phase of expression of Xnr1. We show that the T-box transcription factor
VegT can induce Xnr1. It had previously been shown that Xnr1 can induce VegT in
ectoderm cells and we show that the early expression of Xnr1 is regulated by an
autoregulatory loop. By inspection of the Xnr1 promoter sequence, we have
identified two non-palindromic T-box-binding sites, which are 10 bp apart. Using
mutational analysis, we have shown that these elements are required for the VegT
induction of Xnr1. The Xnr1 promoter shows striking homologies with the Xnr3
promoter. In particular, two elements that are required for Wnt signaling are
conserved between these two promoters, but the two T-box sites are not conserved,
and Xnr3 is not induced by VegT. A region of the promoter containing the T-box
sites and the Wnt sites is sufficient to drive expression of a reporter gene in a
dorsal domain in transgenic Xenopus at the gastrula stage. We show that this
pattern of expression of the transgene in gastrulae is not dependent on the T-box
sites.
PMID- 10683176
TI - Kinase independent function of EphB receptors in retinal axon pathfinding to the
optic disc from dorsal but not ventral retina.
AB - Optic nerve formation requires precise retinal ganglion cell (RGC) axon
pathfinding within the retina to the optic disc, the molecular basis of which is
not well understood. At CNS targets, interactions between Eph receptor tyrosine
kinases on RGC axons and ephrin ligands on target cells have been implicated in
formation of topographic maps. However, studies in chick and mouse have shown
that both Eph receptors and ephrins are also expressed within the retina itself,
raising the possibility that this receptor-ligand family mediates aspects of
retinal development. Here, we more fully document the presence of specific EphB
receptors and B-ephrins in embryonic mouse retina and provide evidence that EphB
receptors are involved in RGC axon pathfinding to the optic disc. We find that as
RGC axons begin this pathfinding process, EphB receptors are uniformly expressed
along the dorsal-ventral retinal axis. This is in contrast to the previously
reported high ventral-low dorsal gradient of EphB receptors later in development
when RGC axons map to CNS targets. We show that mice lacking both EphB2 and EphB3
receptor tyrosine kinases, but not each alone, exhibit increased frequency of RGC
axon guidance errors to the optic disc. In these animals, major aspects of
retinal development and cellular organization appear normal, as do the expression
of other RGC guidance cues netrin, DCC, and L1. Unexpectedly, errors occur in
dorsal but not ventral retina despite early uniform or later high ventral
expression of EphB2 and EphB3. Furthermore, embryos lacking EphB3 and the kinase
domain of EphB2 do not show increased errors, consistent with a guidance role for
the EphB2 extracellular domain. Thus, while Eph kinase function is involved in
RGC axon mapping in the brain, RGC axon pathfinding within the retina is
partially mediated by EphB receptors acting in a kinase-independent manner.
PMID- 10683177
TI - Completion of meiosis in Drosophila oocytes requires transcriptional control by
grauzone, a new zinc finger protein.
AB - Mutations in grauzone or cortex cause abnormal arrest in Drosophila female
meiosis. We cloned grauzone and identified it as a C2H2-type zinc finger
transcription factor. The grauzone transcript is present in ovaries and at later
developmental stages. A Grauzone-GFP fusion protein is functional and localizes
to nuclei of both nurse cells and follicle cells during oogenesis. Three lines of
evidence indicate that grauzone and cortex interact: reducing cortex function
enhanced the grauzone mutant phenotype; cortex transcript abundance is reduced in
the absence of grauzone function and Grauzone protein binds to the cortex
promoter. These results demonstrate that activation of cortex transcription by
grauzone is necessary for the completion of meiosis in Drosophila oocytes, and
establish a new pathway that specifically regulates the female meiotic cell
cycle.
PMID- 10683178
TI - A retrograde signal is involved in activity-dependent remodeling at a C. elegans
neuromuscular junction.
AB - We have characterized how perturbations of normal synaptic activity influence the
morphology of cholinergic SAB motor neurons that innervate head muscle in C.
elegans. Mutations disrupting components of the presynaptic release apparatus,
acetylcholine (ACh) synthesis or ACh loading into synaptic vesicles each induced
sprouting of SAB axonal processes. These sprouts usually arose in the middle of
the normal innervation zone and terminated with a single presynaptic varicosity.
Sprouting SAB neurons with a similar morphology were also observed upon reducing
activity in muscle, either by using mutants lacking a functional nicotinic ACh
receptor subunit or through muscle-specific expression of a gain-of-function
potassium channel. Analysis of temperature-sensitive mutants in the choline
acetyltransferase gene revealed that the sprouting response to inactivity was
developmentally regulated; reduction of synaptic activity in early larval stages,
but not in late larval stages, induced both sprouting and addition of
varicosities. Our results indicate that activity levels regulate the structure of
certain synaptic connections between nerve and muscle in C. elegans. One
component of this regulatory machinery is a retrograde signal from the
postsynaptic cell that mediates the formation of synaptic connections.
PMID- 10683179
TI - Regulation of cell proliferation patterns by homeotic genes during Arabidopsis
floral development.
AB - The shoot apical meristem of Arabidopsis thaliana consists of three cell layers
that proliferate to give rise to the aerial organs of the plant. By labeling
cells in each layer using an Ac-based transposable element system, we mapped
their contributions to the floral organs, as well as determined the degree of
plasticity in this developmental process. We found that each cell layer
proliferates to give rise to predictable derivatives: the L1 contributes to the
epidermis, the stigma, part of the transmitting tract and the integument of the
ovules, while the L2 and L3 contribute, to different degrees, to the mesophyll
and other internal tissues. In order to test the roles of the floral homeotic
genes in regulating these patterns of cell proliferation, we carried out similar
clonal analyses in apetala3-3 and agamous-1 mutant plants. Our results suggest
that cell division patterns are regulated differently at different stages of
floral development. In early floral stages, the pattern of cell divisions is
dependent on position in the floral meristem, and not on future organ identity.
Later, during organogenesis, the layer contributions to the organs are controlled
by the homeotic genes. We also show that AGAMOUS is required to maintain the
layered structure of the meristem prior to organ initiation, as well as having a
non-autonomous role in the regulation of the layer contributions to the petals.
PMID- 10683180
TI - Different clonal dispersion in the rostral and caudal mouse central nervous
system.
AB - We have performed a systematic clonal analysis to describe the modes of growth,
dispersion and production of cells during the development of the mouse neural
system. We have used mice expressing a LaacZ reporter gene under the control of
the neuron specific enolase promoter to randomly generate LacZ clones in the
central nervous system (CNS). We present evidence for (1) a pool of CNS founder
cells that is not regionalized, i.e. give descendants dispersed along the entire
A-P axis, (2) an early separation between pools of precursors for the anterior
and posterior CNS and (3) distinct modes of production of progenitors in these
two domains. More specifically, cell growth and dispersion of the progenitors
follow a relatively coherent pattern throughout the anterior CNS, a mode that
leads to a progressive regionalization of cell fates. In contrast, cell growth of
progenitors of the SC appears to involve self-renewing stem cells that progress
caudally during regression of the mode. Therefore, at least part of the area
surrounding the node is composed of precursors with self-renewing properties and
the development of the trunk is dependent on pools of stem cells regressing from
A to P. Taken together with our analysis of the cell growth changes associated
with neuromere formation (Mathis, L., Sieur, J., Voiculescu, O., Charnay, P. and
Nicolas, J. F. (1999) Development 126, 4095-4106), our results suggest that major
transitions in CNS development correspond to changes in cell behavior and may
provide a link between morphogenesis and genetic patterning mechanisms (i.e.
formation of the body plan).
PMID- 10683181
TI - The Abruptex domain of Notch regulates negative interactions between Notch, its
ligands and Fringe.
AB - The Notch signalling pathway regulates cell fate choices during both vertebrate
and invertebrate development. In the Drosophila wing disc, the activation of
Notch by its ligands Delta and Serrate is required to make the dorsoventral
boundary, where several genes, such as wingless and cut, are expressed in a 2- to
4-cell-wide domain. The interactions between Notch and its ligands are modulated
by Fringe via a mechanism that may involve post-transcriptional modifications of
Notch. The ligands themselves also help to restrict Notch activity to the
dorsoventral boundary cells, because they antagonise the activation of the
receptor in the cells where their expression is high. This function of the
ligands is critical to establish the polarity of signalling, but very little is
known about the mechanisms involved in the interactions between Notch and its
ligands that result in suppression of Notch activity. The extracellular domain of
Notch contains an array of 36 EGF repeats, two of which, repeats 11 and 12, are
necessary for direct interactions between Notch with Delta and Serrate. We
investigate here the function of a region of the Notch extracellular domain where
several missense mutations, called Abruptex, are localised. These Notch alleles
are characterised by phenotypes opposite to the loss of Notch function and also
by complex complementation patterns. We find that, in Abruptex mutant discs, only
the negative effects of the ligands and Fringe are affected, resulting in the
failure to restrict the expression of cut and wingless to the dorsoventral
boundary. We suggest that Abruptex alleles identify a domain in the Notch protein
that mediates the interactions between Notch, its ligands and Fringe that result
in suppression of Notch activity.
PMID- 10683182
TI - Distinct effects of XBF-1 in regulating the cell cycle inhibitor p27(XIC1) and
imparting a neural fate.
AB - XBF-1 is an anterior neural plate-specific, winged helix transcription factor
that affects neural development in a concentration-dependent manner. A high
concentration of XBF-1 results in suppression of endogenous neuronal
differentiation and an expansion of undifferentiated neuroectoderm. Here we
investigate the mechanism by which this expansion is achieved. Our findings
suggest that XBF-1 converts ectoderm to a neural fate and it does so
independently of any effects on the mesoderm. In addition, we show that a high
dose of XBF-1 promotes the proliferation of neuroectodermal cells while a low
dose inhibits ectodermal proliferation. Thus, the neural expansion observed after
high dose XBF-1 misexpression is due both to an increase in the number of
ectodermal cells devoted to a neural fate and an increase in their proliferation.
We show that the effect on cell proliferation is likely to be mediated by
p27(XIC1), a cyclin-dependent kinase (cdk) inhibitor. We show that p27(XIC1) is
expressed in a spatially restricted pattern in the embryo, including the anterior
neural plate, and when misexpressed it is sufficient to block the cell cycle in
vivo. We find that p27(XIC1 )is transcriptionally regulated by XBF-1 in a dose
dependent manner such that it is suppressed or ectopically induced by a high or
low dose of XBF-1, respectively. However, while a low dose of XBF-1 induces
ectopic p27(XIC1 )and ectopic neurons, misexpression of p27(XIC1 )does not induce
ectopic neurons, suggesting that the effects of XBF-1 on cell fate and cell
proliferation are distinct. Finally, we show that p27(XIC1 )is suppressed by XBF
1 in the absence of protein synthesis, suggesting that at least one component of
p27(XIC1 )regulation by XBF-1 may be direct. Thus, XBF-1 is a neural-specific
transcription factor that can independently affect both the cell fate choice and
the proliferative status of the cells in which it is expressed.
PMID- 10683183
TI - The neurofibromatosis-2 homologue, Merlin, and the tumor suppressor expanded
function together in Drosophila to regulate cell proliferation and
differentiation.
AB - Neurofibromatosis-2 is an inherited disorder characterized by the development of
benign schwannomas and other Schwann-cell-derived tumors associated with the
central nervous system. The Neurofibromatosis-2 tumor suppressor gene encodes
Merlin, a member of the Protein 4.1 superfamily most closely related to Ezrin,
Radixin and Moesin. This discovery suggested a novel function for Protein 4.1
family members in the regulation of cell proliferation; proteins in this family
were previously thought to function primarily to link transmembrane proteins to
underlying cortical actin. To understand the basic cellular functions of Merlin,
we are investigating a Drosophila Neurofibromatosis-2 homologue, Merlin. Loss of
Merlin function in Drosophila results in hyperplasia of the affected tissue
without significant disruptions in differentiation. Similar phenotypes have been
observed for mutations in another Protein 4.1 superfamily member in Drosophila,
expanded. Because of the phenotypic and structural similarities between Merlin
and expanded, we asked whether Merlin and Expanded function together to regulate
cell proliferation. In this study, we demonstrate that recessive loss of function
of either Merlin or expanded can dominantly enhance the phenotypes associated
with mutations in the other. Consistent with this genetic interaction, we
determined that Merlin and Expanded colocalize in Drosophila tissues and cells,
and physically interact through a conserved N-terminal region of Expanded,
characteristic of the Protein 4.1 family, and the C-terminal domain of Merlin.
Loss of function of both Merlin and expanded in clones revealed that these
proteins function to regulate differentiation in addition to proliferation in
Drosophila. Further genetic analyses suggest a role for Merlin and Expanded
specifically in Decapentaplegic-mediated differentiation events. These results
indicate that Merlin and Expanded function together to regulate proliferation and
differentiation, and have implications for understanding the functions of other
Protein 4.1 superfamily members.
PMID- 10683184
TI - Morphogenetic furrow initiation and progression during eye development in
Drosophila: the roles of decapentaplegic, hedgehog and eyes absent.
AB - The Drosophila signaling factor decapentaplegic (dpp) mediates the effects of
hedgehog (hh) in tissue patterning by regulating the expression of tissue
specific genes. In the eye disc, the transcription factors eyeless (ey), eyes
absent (eya), sine oculis (so) and dachshund (dac) participate with these
signaling molecules in a complex regulatory network that results in the
initiation of eye development. Our analysis of functional relationships in the
early eye disc indicates that hh and dpp play no role in regulating ey, but are
required for eya, so and dac expression. We show that restoring expression of eya
in loss-of-function dpp mutant backgrounds is sufficient to induce so and dac
expression and to rescue eye development. Thus, once expressed, eya can carry out
its functions in the absence of dpp. These experiments indicate that dpp
functions downstream of or in parallel with ey, but upstream of eya, so and dac.
Additional control is provided by a feedback loop that maintains expression of
eya and so and includes dpp. The fact that exogenous overexpression of ey, eya,
so and dac interferes with wild-type eye development demonstrates the importance
of such a complicated mechanism for maintaining proper levels of these factors
during early eye development. Whereas initiation of eye development fails in
either Hh or Dpp signaling mutants, the subsequent progression of the
morphogenetic furrow is only slowed down. However, we find that clones that are
simultaneously mutant for Hh and Dpp signaling components completely block furrow
progression and eye differentiation, suggesting that Hh and Dpp serve partially
redundant functions in this process. Interestingly, furrow-associated expression
of eya, so and dac is not affected by double mutant tissue, suggesting that some
other factor(s) regulates their expression during furrow progression.
PMID- 10683185
TI - The pharmacology of hSK1 Ca2+-activated K+ channels expressed in mammalian cell
lines.
AB - The pharmacology of hSK1, a small conductance calcium-activated potassium
channel, was studied in mammalian cell lines (HEK293 and COS-7). In these cell
types, hSK1 forms an apamin-sensitive channel with an IC(50) for apamin of 8 nM
in HEK293 cells and 12 nM in COS-7 cells. The currents in HEK293 cells were also
sensitive to tubocurarine (IC(50)=23 microM), dequalinium (IC(50)=0.4 microM),
and the novel dequalinium analogue, UCL1848 (IC(50)=1 nM). These results are very
different from the pharmacology of hSK1 channels expressed in Xenopus oocytes and
suggest the properties of the channel may depend on the expression system. Our
findings also raise questions about the role of SK1 channels in generating the
apamin-insensitive slow afterhyperpolarization observed in central neurones.
PMID- 10683186
TI - Antihyperglycemic action of isoferulic acid in streptozotocin-induced diabetic
rats.
AB - Wistar rats with streptozotocin-induced diabetes (STZ-diabetic rats), which is
similar to human insulin-dependent diabetic mellitus (IDDM), were employed to
investigate the antihyperglycemic action of isoferulic acid. A single intravenous
injection of isoferulic acid decreased the plasma glucose in a dose-dependent
manner in the STZ-diabetic rats. Repeated intravenous administration of STZ
diabetic rats with isoferulic acid (5.0 mg kg(-1)) also resulted in the lowering
of plasma glucose after one day. Stimulatory effects of isoferulic acid on the
glucose uptake and glycogen synthesis in soleus muscles isolated from STZ
diabetic rats were also obtained indicating an increase of glucose utilization
following isoferulic acid treatment which was not dependent on insulin. The mRNA
level of glucose transporter subtype 4 form (GLUT4) in soleus muscle was raised
by isoferulic acid after repeated treatment for 1 day in STZ-diabetic rats.
Similar repeated treatment with isoferulic acid reversed the elevated mRNA level
of phosphoenolpyruvate carboxykinase (PEPCK) in liver of STZ-diabetic rats to the
normal level. However, expression of GLUT4 and PEPCK genes in nondiabetic rats
were not influenced by similar treatment with isoferulic acid. These results
suggest that isoferulic acid can inhibit hepatic gluconeogenesis and/or increase
the glucose utilization in peripheral tissue to lower plasma glucose in diabetic
rats lacking insulin.
PMID- 10683187
TI - Beta 1-, beta 2- and atypical beta-adrenoceptor-mediated relaxation in rat
isolated aorta.
AB - beta-adrenoceptor-mediated relaxation was investigated in ring preparations of
rat isolated thoracic aorta. Rings were pre-constricted with a sub-maximal
concentration of noradrenaline (1 microM) and relaxant responses to cumulative
concentrations of beta-adrenoceptor agonists obtained. The concentration-response
curve (CRC) to isoprenaline was shifted to the right by propranolol (0.3 microM)
with a steepening of the slope. Estimation of the magnitude of the shift from
EC(50) values gave a pA(2) of 7.6. Selective beta(1)- and beta(2)-adrenoceptor
antagonists, CGP 20712A (0.1 microM) and ICI 118551 (0.1 microM), respectively,
produced 4 and 14 fold shifts of the isoprenaline CRC. Atypical beta-adrenoceptor
agonists also produced concentration-dependent relaxation of aortic rings. The
order of potency of the beta-adrenoceptor agonists was (-log EC(50)):
isoprenaline (6. 25)>cyanopindolol (5.59)>isoprenaline+propranolol (5.11)>CGP
12177A (4.40)>ZD 2079 (4.24)>ZM 215001 (4.07)>BRL 37344 (3.89). Relaxation to CGP
12177A and ZM 215001 was unaffected by propranolol (0.3 microM). SR 59230A (=1
microM) and cyanopindolol (1 microM), beta(3)-adrenoceptor antagonists, had no
effect on the isoprenaline (in the presence of propranolol) or CGP 12177A CRCs.
Bupranolol and CGP 20712A, at microM concentrations (beta(4)-adrenceptor
antagonists), inhibited responses to isoprenaline (in the presence of
propranolol) and CGP 12177A. In conclusion, atypical beta-adrenoceptors co-exist
with beta(1)- and beta(2)-adrenoceptors in rat aorta. Although non-conventional
partial agonists and selective beta(3)-adrenoceptor agonist cause relaxation, the
vascular atypical beta-adrenoceptor does not appear to correspond to the beta(3)
adrenoceptor. There are, however, similarities with the putative beta(4)
adrenoceptor.
PMID- 10683188
TI - Comparison of novel cannabinoid partial agonists and SR141716A in the guinea-pig
small intestine.
AB - The controversial nature of the CB(1) receptor antagonist, SR141716A, in the
guinea-pig small intestine was investigated by comparing it with four analogues
of Delta(8)-tetrahydrocannabinol (Delta(8)-THC): O-1184, O-1238, O-584 and O
1315. These compounds (10 - 1000 nM) inhibited the electrically-evoked
contractions with a rank order of potency of O-1238>O-1184>O-584>O-1315. Log
concentration-response curves for O-1238, O-1184 and O-1315 were significantly
shifted to the right by SR141716A and the maxima were significantly less than
that of the CB(1) agonist, WIN55212-2, an indication of partial agonism. Partial
saturation of the triple bond in O-1184 to a cis double bond (O-1238) increased
its potency as an agonist (pEC(50) from 6.42 to 7.63) and as an antagonist of
WIN55212-2, (pK(B), from 8.36 to 9.49). Substitution of the terminal azide group
by an ethyl group (O-584) or removal of the phenolic hydroxyl group (O-1315) had
no significant effect on the agonist or antagonist potency. None of these
analogues increased the twitch response in a manner resembling that of SR141716A.
O-1184 (10 and 100 nM) shifted the log concentration-response curve of WIN55212-2
for inhibition of the twitch responses to the right with pK(B) values of 8.29 and
8.38, respectively. We conclude that these Delta(8)-THC analogues behave as
partial agonists rather than silent antagonists at CB(1) binding sites in this
tissue. There was no evidence of antagonism of endocannabinoids thus supporting
the hypothesis that, in this tissue, SR141716A is an inverse agonist of
constitutively active CB(1) receptors.
PMID- 10683189
TI - Differential response to chloroethylclonidine in blood vessels of normotensive
and spontaneously hypertensive rats: role of alpha 1D- and alpha 1A-adrenoceptors
in contraction.
AB - The effects of chloroethylclonidine on alpha(1)-adrenoceptor-mediated contraction
in endothelium-denuded caudal arteries and aorta from normotensive Wistar and
Wistar Kyoto (WKY), and from spontaneously hypertensive (SHR) rats were
evaluated. Chloroethylclonidine elicited concentration-dependent contractions.
Maximal contraction was similar in caudal arteries among strains ( approximately
40% of noradrenaline effect). However, chloroethylclonidine elicited a higher
contraction in aorta from SHR than from normotensive rats. In Wistar aorta
chloroethylclonidine produced the smallest contractile response. In SHR aorta,
BMY 7378 and 5-methylurapidil blocked chloroethylclonidine-elicited contraction,
while (+)-cyclazocine did not inhibit it; while in caudal arteries, 5
methylurapidil blocked chloroethylclonidine action; the other antagonists had no
effect. In chloroethylclonidine-treated aorta noradrenaline elicited biphasic
contraction-response curves, indicating a high affinity (pD(2), 8.5 - 7.5)
chloroethylclonidine-sensitive component and a low affinity (pD(2), 6.3 - 5.2)
chloroethylclonidine-insensitive component. The high affinity component was
blocked by chloroethylclonidine; while in caudal arteries noradrenaline elicited
monophasic contraction-response curves with pD(2) values (6.5 - 5.7) similar to
the low affinity component in aorta. Chloroethylclonidine inhibition of
noradrenaline response was greater in aorta than in caudal arteries.
Chloroethylclonidine increased the EC(50) values of noradrenaline approximately
1000 fold in aorta and approximately 10 fold in caudal arteries. In SHR aorta BMY
7378 protected alpha(1D)-adrenoceptors and in caudal arteries 5-methylurapidil
protected alpha(1A)-adrenoceptors from chloroethylclonidine alkylation, allowing
noradrenaline to elicit contraction. These results show marked strain-dependent
differences in the ability of chloroethylclonidine to contract aorta; moreover,
chloroethylclonidine stimulates alpha(1D)-adrenoceptors in aorta and alpha(1A)
adrenoceptors in caudal arteries. The higher contraction observed in aorta from
SHR and WKY suggests an augmented number of alpha(1D)-adrenoceptors in these
strains.
PMID- 10683190
TI - Effects of selective inhibitors of cyclo-oxygenase-1 (COX-1) and cyclo-oxygenase
2 (COX-2) on the spontaneous myogenic contractions in the upper urinary tract of
the guinea-pig and rat.
AB - The role of cyclo-oxygenase-1 (COX-1) and cyclo-oxygenase-2 (COX-2) in the upper
urinary tract of the guinea-pig and rat was examined using simultaneous tension
recordings of the proximal and distal regions of the renal pelvis and the ureter.
The guinea-pig upper urinary tract contracted at a frequency (7.52+/-0.3 min(-1)
at 35 degrees C) significantly lower than the frequency in the proximal renal
pelvis (21.6+/-1.3 min(-1)) and in the distal renal pelvis and ureter (20.2+/-1.4
min(-1)) of the rat (at 30 degrees C). Indomethacin (>/=1 microM for 60 min),
decreased the motility index (amplitudexfrequency) (MI) in all three regions of
the guinea-pig upper urinary tract, an effect which mainly arose from a decrease
in the frequency of contractions. In the rat, indomethacin (1 - 30 microM for 60
min) significantly decreased the MI calculated in the proximal renal pelvis
(>/=30 microM indomethacin), and in the distal renal pelvis (>/=10 microM
indomethacin), arising from a significant decrease in the amplitude of
contractions. The COX-1 inhibitor, valeryl salicylate (VSA) (5 - 100 microM for
60 min), had no effect on either the amplitude or frequency of contractions in
the guinea-pig upper urinary tract. In contrast, VSA increased the force of
contractions in the proximal and distal renal pelvis of the rat, whilst having
little effect on the frequency of contractions. The COX-2 inhibitor, NS-398 (10 -
100 nM for 60 min) reduced the MI in the guinea-pig upper urinary tract in a
concentration-dependent manner. The MIs calculated for the proximal renal pelvis,
distal renal pelvis and ureter, were decreased by 72, 64 and 72% respectively, in
100 nM NS-398. NS-398 (10 - 100 nM) had no effect on any of the three parameters
measured in either the proximal or distal renal pelvis of the rat. These data
suggest that endogenously-released prostaglandins (PGs) maintain the myogenic
contractility of the upper urinary tract in both the guinea-pig and rat. Moreover
COX-2 is the primary enzyme involved in synthesizing PGs in the guinea-pig upper
urinary tract, while COX-1 appears to be the predominantly active enzyme in the
rat.
PMID- 10683191
TI - The effects of Z13752A, a combined ACE/NEP inhibitor, on responses to coronary
artery occlusion; a primary protective role for bradykinin.
AB - The effects on the responses to coronary artery occlusion of a combined ACE/NEP
inhibitor (Z13752A) were examined in anaesthetized dogs. A 1 h infusion of
Z13752A (128 microgram kg(-1) min(-1) intravenously) decreased arterial blood
pressure (by 11+/-3%; P<0. 05) and increased coronary blood flow (by 12+/-4%,
P<0.05). There were no other significant haemodynamic changes. Z13752A inhibited
both NEP and ACE enzymes both in dog plasma and in tissue (lung ACE; kidney NEP).
Pressor responses to angiotensin I in vivo were inhibited and systemic
vasodilator responses to bradykinin were potentiated. When the left anterior
descending coronary artery was occluded for 25 min, Z13752A markedly reduced the
severity of the resultant ventricular arrhythmias. No ventricular fibrillation
(VF) occurred (compared to 7/16 in the controls; P<0.05), and ventricular
tachycardia (VT) was reduced (VT in 2/9 dogs treated with Z13752A cp. 16/16 of
controls; episodes of VT 0.2+/-0.1 c.p. 10.7+/-3.3; P<0. 05). Reperfusion of the
ischaemic myocardium led to VF in all control dogs but occurred less frequently
in dogs given Z13752A (survival from the combined ischaemia-reperfusion insult
67% c.p. 0% in controls; P<0.05). Z13752A reduced two other indices of ischaemia
severity; epicardial ST-segment elevation and inhomogeneity of electrical
activation. These protective effects of Z13752A during ischaemia and reperfusion
were abolished by the administration of icatibant (0.3 mg kg(-1), i.v.) a
selective antagonist of bradykinin at B(2) receptors; the ischaemic changes in
dogs given both icatibant and Z13752A were similar to those in the controls. We
conclude that this ACE/NEP inhibitor is effective at reducing the consequences of
coronary artery occlusion in this canine model and that this protection is
primarily due to potentiation of released bradykinin. British Journal of
Pharmacology (2000) 129, 671 - 680
PMID- 10683192
TI - Wound collagen deposition in rats: effects of an NO-NSAID and a selective COX-2
inhibitor.
AB - Selective cyclo-oxygenase (COX)-2 inhibitors and nitric oxide-releasing
nonsteroidal anti-inflammatory drugs (NSAIDs) exhibit reduced toxicity in the
gastrointestinal tract, but may affect wound healing in other tissues. In this
study, we have compared the effects of a selective COX-2 inhibitor (celecoxib), a
nitric-oxide releasing derivative of naproxen (HCT-3012) and naproxen in a model
of wound collagen deposition in the rat. Polyvinyl alcohol sponges were implanted
subcutaneously in rats. The rats were treated daily for 5 days with the test
drugs at equieffective anti-inflammatory doses. Naproxen (10 mg kg(-1))
significantly decreased (45%) collagen deposition at the wound site relative to
the vehicle-treated control group. In contrast, HCT-3012 (14.5 mg kg(-1))
significantly increased (62%) collagen deposition, while celecoxib (10 mg kg(-1))
had no effect. Naproxen and HCT-3012 suppressed prostaglandin (PG) E(2) levels at
the wound site and whole blood thromboxane synthesis to similar degrees.
Celecoxib had no significant effect on wound fluid PGE(2) levels, but slightly
reduced whole blood thromboxane synthesis (by 17%). COX-1 mRNA and protein were
expressed in the wound exudate, the skin surrounding the wound and in normal
skin. In contrast, COX-2 mRNA, but not protein, was expressed in wound and normal
skin. These results demonstrate that HCT-3012 can significantly enhance collagen
deposition at a wound site, despite inhibiting prostaglandin synthesis to the
same extent as the parent drug. Nitric oxide-releasing NSAIDs may represent a
safer alternative to standard NSAIDs for use as anti-inflammatory and analgesic
agents by post-surgery patients.
PMID- 10683193
TI - Hamster pancreatic beta cell lines with altered sensitivity towards apoptotic
signalling by phosphatase inhibitors.
AB - Specific inhibitors of serine/threonine phosphatases like okadaic acid can induce
apoptotic cell death in the pancreatic beta cell line HIT. Cultivation in
stepwise increased concentrations of okadaic acid enabled the isolation of
HIT100R cells which proliferate at 100 nM okadaic acid (8 - 10 times the
initially lethal concentration). These two cell lines were used to characterize
the events triggered by okadaic acid that led to apoptosis. Biochemical markers,
e.g. cytochrome c release from mitochondria and increase of caspase-3-like
activity, revealed that induction of apoptosis by 100 nM okadaic acid in parental
HIT cells started with the release of cytochrome c. In HIT100R cells 500 nM
okadaic acid were necessary to induce alterations comparable to those observed
with 100 nM okadaic acid in non-resistant HIT cells. In contrast to okadaic acid,
the potency of the structurally different phosphatase inhibitor cantharidic acid
to induce cytochrome c release, increase of caspase-3-like activity and DNA
fragmentation was comparable in HIT and HIT100R cells. Thus, no cross-resistance
between these phosphatase inhibitors seemed to exist. Phosphatase activity in
extracts from HIT and HIT100R cells did not differ in its total amount or in its
sensitivity for okadaic acid. Since higher concentrations of okadaic acid were
needed to induce apoptosis in HIT100R cells, a compromised intracellular
accumulation of the toxin appeared likely. Functional and structural analysis
revealed that this was achieved by the development of the multidrug resistance
phenotype in HIT100R cells. The underlying mechanism appeared to be the enhanced
expression of the pgp1 but not the pgp2 gene.
PMID- 10683194
TI - Voltage-dependent inhibition of the muscarinic cationic current in guinea-pig
ileal cells by SK&F 96365.
AB - The effects of SK&F 96365 on cationic current evoked either by activating
muscarinic receptors with carbachol or by intracellularly applied GTPgammaS (in
the absence of carbachol) were studied using patch-clamp recording techniques in
single guinea-pig ileal smooth muscle cells. SK&F 96365 reversibly inhibited the
muscarinic receptor cationic current in a concentration-, time- and voltage
dependent manner producing concomitant alteration of the steady-state I-V
relationship shape which could be explained by assuming that increasing membrane
positivity increased the affinity of the blocker. The inhibition was similar for
both carbachol- and GTPgammaS-evoked currents suggesting that the cationic
channel rather than the muscarinic receptor was the primary site of the SK&F
96365 action. Increased membrane positivity induced additional rapid inhibition
of the cationic current by SK&F 96365 which was more slowly relieved during
membrane repolarization. Both the inhibition and disinhibition time course could
be well fitted by a single exponential function with the time constants
decreasing with increasing positivity for the inhibition (e-fold per about 12 mV)
and approximately linearly decreasing with increasing negativity for the
disinhibition. At a constant SK&F 96365 concentration, the degree of cationic
current inhibition was a sigmoidal function of the membrane potential with a
potential of half-maximal increase positive to about +30 mV and a slope factor of
about -13 mV. Increasing the duration of voltage steps at -80 or at 80 mV,
increased the percentage inhibition; the degree of inhibition was almost
identical at both potentials providing evidence that the same cationic channel
was responsible for the cationic current both at negative and at positive
potentials. It is concluded that the distinctive and unique mode of SK&F 96365
action on the muscarinic receptor cationic channel is a valuable tool in future
molecular biology studies of this channel.
PMID- 10683195
TI - Bromoenol lactone enhances the permeabilization of rat submandibular acinar cells
by P2X7 agonists.
AB - The permeabilizing effect of P2X(7) agonists was tested in rat submandibular
acinar cells using the uptake of ethidium bromide as an index. The uptake of
ethidium bromide by acini incubated at 37 degrees C in the presence of 1 mM ATP
increased with time and reached after 5 min about 10% of maximal uptake measured
in the presence of digitonin. The response to ATP was dose-dependent (half
maximal concentration around 40 microM) and it was decreased when the temperature
was lowered to 25 degrees C. Benzoyl-ATP reproduced the response to ATP (half
maximal concentration around 10 microM). UTP or 2-methylthioATP had no effect.
The permeabilization in response to ATP was blocked by oxidized ATP and by
magnesium and inhibited by Coomassie blue. ATP increased the activity of a
calcium-insensitive phospholipase A(2) (iPLA(2)). Bromoenol lactone (BEL)
inhibited the iPLA(2) stimulated by ATP but potentiated the uptake of ethidium
bromide in response to the purinergic agonist. From these results it is concluded
that the activation of P2X(7) receptors permeabilizes rat submandibular acinar
cells. The pore-forming activity of the receptor might be negatively regulated by
the concomitant activation of the iPLA(2) by the receptor.
PMID- 10683196
TI - M-type K+ currents in rat cultured thoracolumbar sympathetic neurones and their
role in uracil nucleotide-evoked noradrenaline release.
AB - Cultured sympathetic neurones are depolarized and release noradrenaline in
response to extracellular ATP, UDP and UTP. We examined the possibility that, in
neurones cultured from rat thoracolumbar sympathetic ganglia, inhibition of the M
type potassium current might underlie the effects of UDP and UTP. Reverse
transcriptase-polymerase chain reaction indicated that the cultured cells
contained mRNA for P2Y(2)-, P2Y(4)- and P2Y(6)-receptors as well as for the KCNQ2
and KCNQ3-subunits which have been suggested to assemble into M-channels. In
cultures of neurones taken from newborn as well as from 10 day-old rats,
oxotremorine, the M-channel blocker Ba(2+) and UDP all released previously stored
[(3)H]-noradrenaline. The neurones possessed M-currents, the kinetic properties
of which were similar in neurones from newborn and 9 - 12 day-old rats. UDP, UTP
and ATP had no effect on M-currents in neurones prepared from newborn rats.
Oxotremorine and Ba(2+) substantially inhibited the current. ATP also had no
effect on the M-current in neurones prepared from 9 - 12 day-old rats.
Oxotremorine and Ba(2+) again caused marked inhibition. In contrast to cultures
from newborn animals, UDP and UTP attenuated the M-current in neurones from 9 -
12 day-old rats; however, the maximal inhibition was less than 30%. The results
indicate that inhibition of the M-current is not involved in uracil nucleotide
induced transmitter release from rat cultured sympathetic neurones during early
development. M-current inhibition may contribute to release at later stages, but
only to a minor extent. The mechanism leading to noradrenaline release by UDP and
UTP remains unknown.
PMID- 10683197
TI - Protein phosphatase-protein kinase interplay modulates alpha 1b-adrenoceptor
phosphorylation: effects of okadaic acid.
AB - In the present work we studied the effect of protein phosphatase inhibitors on
the phosphorylation state and function of alpha(1b)-adrenoceptors. Okadaic acid
increased receptor phosphorylation in a time- and concentration-dependent fashion
(maximum at 30 min, EC(50) of 30 nM). Other inhibitors of protein phosphatases
(calyculin A, tautomycin and cypermethrin) mimicked this effect. Staurosporine
and Ro 31-8220, inhibitors of protein kinase C, blocked the effect of okadaic
acid on receptor phosphorylation. Neither genistein nor wortmannin altered the
effect of okadaic acid. The intense adrenoceptor phosphorylation induced by
okadaic acid altered the adrenoceptor-G protein coupling, as evidenced by a small
decreased noradrenaline-stimulated [(35)S]GTPgammaS binding. Okadaic acid did not
alter the noradrenaline-stimulated increases in intracellular calcium or the
production of inositol trisphosphate. Our data indicate that inhibition of
protein phosphatases increases the phosphorylation state of alpha(1b)
adrenoceptors; this effect seems to involve protein kinase C. In spite of
inducing an intense receptor phosphorylation, okadaic acid alters alpha(1b)
adrenergic actions to a much lesser extent than the direct activation of protein
kinase C by phorbol myristate acetate.
PMID- 10683198
TI - The actions of ether, alcohol and alkane general anaesthetics on GABAA and
glycine receptors and the effects of TM2 and TM3 mutations.
AB - The actions of 13 general anaesthetics (diethyl ether, enflurane, isoflurane,
methoxyflurane, sevoflurane, chloral hydrate, trifluoroethanol, tribromoethanol,
tert-butanol, chloretone, brometone, trichloroethylene, and alpha-chloralose)
were studied on agonist-activated Cl(-) currents at human GABA(A)
alpha(2)beta(1), glycine alpha(1), and GABA(C) rho(1) receptors expressed in
human embryonic kidney 293 cells. All 13 anaesthetics enhanced responses to
submaximal (EC(20)) concentrations of agonist at GABA(A) and glycine receptors,
except alpha-chloralose, which did not enhance responses at the glycine alpha(1)
receptor. None of the anaesthetics studied potentiated GABA responses at the
GABA(C) rho(1) receptor. Potentiation of submaximal agonist currents by the
anaesthetics was studied at GABA(A) and glycine receptors harbouring mutations in
putative transmembrane domains 2 and 3 within GABA(A) alpha(2), beta(1), or
glycine alpha(1) receptor subunits: GABA(A) alpha(2)(S270I)beta(1),
alpha(2)(A291W)beta(1), alpha(2)beta(1)(S265I), and alpha(2)beta(1)(M286W);
glycine alpha(1)(S267I) and alpha(1)(A288W). For all anaesthetics studied except
alpha-chloralose, at least one of the mutations above abolished drug potentiation
of agonist responses at GABA(A) and glycine receptors. alpha-Chloralose produced
efficacious direct activation of the GABA(A) alpha(2)beta(1) receptor (a 'GABA
mimetic' effect). The other 12 anaesthetics produced minimal or no direct
activation of GABA(A) and glycine receptors. A non-anaesthetic isomer of alpha
chloralose, beta-chloralose, was inactive at GABA(A) and glycine receptors and
did not antagonize the actions of alpha-chloralose at GABA(A) receptors. The
implications of these findings for the molecular mechanisms of action of general
anaesthetics at GABA(A) and glycine receptors are discussed.
PMID- 10683199
TI - Cholecystokinin-8 enhances nerve growth factor synthesis and promotes recovery of
capsaicin-induced sensory deficit.
AB - Alterations of nerve growth factor (NGF) expression have been demonstrated during
peripheral nerve disease and the impaired expression or synthesis and
transportation of NGF has been correlated with the pathogenesis of several
peripheral neuropathies. Since exogenous NGF administration seems to cause
undesired side-effects, therapeutical strategies based on the regulation of
endogenous synthesis of NGF could prove useful in the clinical treatment of these
disorders. The aim of the present study was to analyse the effects of exogenous
peripheral administration of the neuropeptide cholecystokinin-8 (CCK-8) on
endogenous NGF synthesis, NGF mRNA and distribution of peripheral neuropeptides
which are known to be regulated by this neurotrophin. To address these questions
we studied the effects of capsaicin (CAPS) before and after the administration of
CCK-8 on NGF levels, NGF mRNA expression and localization, and the concentration
of substance P (SP) and calcitonin gene-related peptide (CGRP) in peripheral
tissue These studies demonstrate that administration of the CCK-8 induces an
increase of NGF protein and mRNA in peripheral tissue. NGF level in paw skin of
CAPS/CCK-8-treated mice is 3 fold higher than in controls (1241+/-110 pg gr(-1)
of tissue wet weight versus 414+/-110 pg gr(-1) of controls) and nearly 6 fold
higher than in CAPS-treated mice (1241+/-110 pg gr(-1) versus 248+/-27 pg gr(
1)). The increase of NGF is correlated with the recovery of impaired nocifensive
behaviour and with an overexpression of SP and CGRP. The evidence that CCK-8
promotes the recovery of sensory deficits suggests a potential clinical use for
this neuropeptide in peripheral neuropathies.
PMID- 10683200
TI - Investigation of the interaction between nitric oxide and vasoactive intestinal
polypeptide in the guinea-pig gastric fundus.
AB - The interaction between nitric oxide (NO) and vasoactive intestinal polypeptide
(VIP) was investigated in isolated circular smooth muscle cells and strips of the
guinea-pig gastric fundus. VIP induced a concentration-dependent inhibition of
carbachol-induced contraction in smooth muscle cells with a maximum at 10(-6) M.
The relaxation by 10(-6) M VIP was inhibited for 79.1+/-5.8% (mean+/-s.e. mean)
by the NO-synthase (NOS) inhibitor L-N(G)-nitroarginine (L-NOARG; 10(-4) M) in a
L-arginine reversible way. Also the inducible NOS (iNOS) selective inhibitor N-(3
(acetaminomethyl)-benzyl)acetamide (1400 W; 10(-6) M) inhibited the VIP-induced
relaxation, but its inhibitory effect was not reversed by L-arginine. When cells
were incubated with the guanylyl cyclase inhibitor 1H-(1,2,4)oxadiazolo(4,3
a)quinoxalin-1-one (ODQ, 10(-6) M), the protein kinase A-inhibitor (R)-p-cyclic
adenosine-3', 5'-monophosphothioate ((R)-p-cAMPS, 10(-6) M) and the
glucocorticoid dexamethasone (10(-5) M), the relaxant effect of VIP was decreased
by respectively 80.9+/-7.6, 77.0+/-11.6 and 87.1+/-4.5%. In circular smooth
muscle strips of the guinea-pig gastric fundus, the VIP (10(-9) - 10(-7) M)
induced relaxations were not significantly influenced by 10(-4) M L-NOARG, 10(-6)
M 1400 W, 10(-6) M ODQ and 10(-5) M dexamethasone. These results suggest that
iNOS, possibly induced by the procedure to prepare the smooth muscle cells, is
involved in the relaxant effect of VIP in isolated smooth muscle cells but not in
smooth muscle strips of the guinea-pig gastric fundus. This study illustrates the
importance of the experimental method when studying the influence of NOS
inhibitors on the relaxation induced by VIP in gastrointestinal smooth muscle
preparations.
PMID- 10683201
TI - Evidence that rat hepatocytes co-express functional P2Y1 and P2Y2 receptors.
AB - Previous studies have indicated the expression of multiple P2Y receptors by rat
hepatocytes although they have not been identified. Here we show by reverse
transcriptase-polymerase chain reaction (RT - PCR) that rat hepatocytes express
mRNA encoding all of the four cloned rat P2Y receptors (P2Y(1), P2Y(2), P2Y(4)
and P2Y(6)). The effects of UTP have been examined on single aequorin-injected
rat hepatocytes. The [Ca(2+)](i) transients induced by UTP were indistinguishable
from those induced by ATP in the same cell. The modulatory effects of elevated
intracellular cyclic AMP concentration were the same on both UTP- and ATP-induced
[Ca(2+)](i) transients. UDP, an agonist at the P2Y(6) receptor, failed to induce
transients in hepatocytes, indicating that functional P2Y(6) receptors coupled to
increased [Ca(2+)](i) are not expressed. The transients evoked by ADP were more
sensitive to inhibition by suramin than those induced by either ATP or UTP.
Within an individual cell, the transients induced by ATP and UTP were inhibited
by the same concentration of suramin. This sensitivity of ATP and UTP responses
to suramin suggests action through P2Y(2) rather than P2Y(4) receptors. Co
application of 30 microM pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid
(PPADS) caused a decrease in frequency and amplitude of transients induced by
ADP. ATP- and UTP-induced transients also displayed a decrease in amplitude in
response to addition of PPADS, but this was accompanied by an increase in
frequency of transients. In conclusion the data presented here are consistent
with the co-expression of P2Y(1) and P2Y(2) receptors by rat hepatocytes.
PMID- 10683202
TI - Isolation of the serotoninergic 5-HT4(e) receptor from human heart and
comparative analysis of its pharmacological profile in C6-glial and CHO cell
lines.
AB - RT - PCR technique was used to clone the human 5-HT(4(e)) receptor (h5-HT(4(e)))
from heart atrium. We showed that this h5-HT(4(e)) receptor splice variant is
restricted to brain and heart atrium. Recombinant h5-HT(4(e)) receptor was stably
expressed in CHO and C6-glial cell lines at 347 and 88 fmol mg(-1) protein,
respectively. Expression of h5-HT(4(e)) receptors at the cell membrane was
confirmed by immunoblotting. The receptor binding profile, determined by
competition with [(3)H]-GR113808 of a number of 5-HT(4) ligands, was consistent
with that previously reported for other 5-HT(4) receptor isoforms. Surprisingly,
we found that the rank order of potencies (EC(50)) of 5-HT(4) agonists obtained
from adenylyl cyclase functional assays was inversely correlated to their rank
order of affinities (K(i)) obtained from binding assays. Furthermore, EC(50)
values for 5-HT, renzapride and cisapride were 2 fold lower in C6-glial cells
than in CHO cells. ML10302 and renzapride behaved like partial agonists on the h5
HT(4(e)) receptor. These results are in agreement with the reported low efficacy
of the these two compounds on L-type Ca(2+) currents and myocyte contractility in
human atrium. A constitutive activity of the h5-HT(4(e)) receptor was observed in
CHO cells in the absence of any 5-HT(4) ligand and two 5-HT(4) antagonists,
GR113808 and ML10375, behaved as inverse agonists. These data show that the h5
HT(4(e)) receptor has a pharmacological profile which is close to the native h5
HT(4) receptor in human atrium with a functional potency which is dependent on
the cellular context in which the receptor is expressed.
PMID- 10683203
TI - Non-prostanoid prostacyclin mimetics as neuronal stimulants in the rat:
comparison of vagus nerve and NANC innervation of the colon.
AB - The spontaneous activity of the rat isolated colon is suppressed by prostacyclin
analogues such as cicaprost (IC(50)=4.0 nM). Activation of prostanoid IP(1)
receptors located on NANC inhibitory neurones is involved. However, several non
prostanoids, which show medium to high IP(1) agonist potency on platelet and
vascular preparations, exhibit very weak inhibitory activity on the colon. The
aim of the study was to investigate this discrepancy. Firstly, we have
demonstrated the very high depolarizing potency of cicaprost on the rat isolated
vagus nerve (EC(50)=0.23 nM). Iloprost, taprostene and carbacyclin were 7.9, 66,
and 81 fold less potent than cicaprost, indicating the presence of IP(1) as
opposed to IP(2)-receptors. Three non-prostanoid prostacyclin mimetics, BMY
45778, BMY 42393 and ONO-1301, although much less potent than cicaprost (195, 990
and 1660 fold respectively), behaved as full agonists on the vagus nerve. On re
investigating the rat colon, we found that BMY 45778 (0.1 - 3 microM), BMY 42393
(3 microM) and ONO-1301 (3 microM) behaved as specific IP(1) partial agonists,
but their actions required 30 - 60 min to reach steady-state and only slowly
reversed on washing. This profile contrasted sharply with the rapid and readily
reversible contractions elicited by a related non-prostanoid ONO-AP-324, which is
an EP(3)-receptor agonist. The full versus partial agonism of the non-prostanoid
prostacyclin mimetics may be explained by the markedly different IP(1) agonist
sensitivities of the two rat neuronal preparations. However, the slow kinetics of
the non-prostanoids on the NANC system of the colon remain unexplained, and must
be taken into account when characterizing neuronal IP-receptors.
PMID- 10683204
TI - Chlorotoxin does not inhibit volume-regulated, calcium-activated and cyclic AMP
activated chloride channels.
AB - It was the aim of this study to look for a high-affinity and selective
polypeptide toxin, which could serve as a probe for the volume-regulated anion
channel (VRAC) or the calcium-activated chloride channel (CaCC). We have
partially purified chlorotoxin, including new and homologous short chain
insectotoxins, from the crude venom of Leiurus quinquestriatus quinquestriatus
(Lqq) by means of gel filtration chromatography. Material eluting between 280 and
420 min, corresponding to fractions 15-21, was lyophilized and tested on VRAC and
CaCC, using the whole-cell patch-clamp technique. We have also tested the
commercially available chlorotoxin on VRAC, CaCC, the cystic fibrosis
transmembrane conductance regulator (CFTR) and on the glioma specific chloride
channel (GCC). VRAC and the correspondent current, I(Cl,swell), was activated in
Cultured Pulmonary Artery Endothelial (CPAE) cells by a 25% hypotonic solution.
Neither of the fractions 16-21 significantly inhibited I(Cl,swell) (n=4-5).
Ca(2+)-activated Cl(-) currents, I(Cl,Ca), activated by loading T84 cells via the
patch pipette with 1 microM free Ca(2+), were not inhibited by any of the tested
fractions (15-21), (n=2-5). Chlorotoxin (625 nM) did neither effect I(Cl,swell)
nor I(Cl,Ca) (n=4-5). The CFTR channel, transiently transfected in COS cells and
activated by a cocktail containing IBMX and forskolin, was not affected by 1.2
microM chlorotoxin (n=5). In addition, it did not affect currents through GCC. We
conclude that submicromolar concentrations of chlorotoxin do not block volume
regulated, Ca(2+)-activated and CFTR chloride channels and that it can not be
classified as a general chloride channel toxin.
PMID- 10683205
TI - Differential effects of ethanol on glycine uptake mediated by the recombinant
GLYT1 and GLYT2 glycine transporters.
AB - The effects of ethanol on the function of recombinant glycine transporter 1
(GLYT1) and glycine transporter 2 (GLYT2) have been investigated. GLYT1b and
GLYT2a isoforms stably expressed in human embryonic kidney 293 (HEK 293) cells
showed a differential behaviour in the presence of ethanol; only the GLYT2a
isoform was acutely inhibited. The 'cut-off' (alcohols with four carbons)
displayed by the n-alkanols on GLYT2a indicates that a specific binding site for
ethanol exists on GLYT2a or on a GLYT2a-interacting protein. The non-competitive
inhibition of GLYT2a indicates an allosteric modulation by ethanol of GLYT2a
activity. Chronic treatment with ethanol caused differential adaptive responses
on the activity and the membrane expression levels of these transporters. The
neuronal GLYT2a isoform decreased in activity and surface expression and the
mainly glial GLYT1b isoform slightly increased in function and surface density.
These changes may be involved in some of the modifications of glycinergic or
glutamatergic neurotransmitter systems produced by ethanol intoxication.
PMID- 10683207
TI - Agonist binding to G-protein coupled receptors.
PMID- 10683206
TI - Apamin-sensitive, non-nitric oxide (NO) endothelium-dependent relaxations to
bradykinin in the bovine isolated coronary artery: no role for cytochrome P450
and K+.
AB - Since cytochrome P(450)-derived metabolites of arachidonic acid and K(+) have
been implicated in endothelium-derived hyperpolarizing factor (EDHF)-dependent
responses, the aim of this study was to determine whether such factors contribute
to non-nitric oxide (NO), endothelium-dependent relaxation to bradykinin (BK) in
bovine isolated coronary artery. In rings of artery contracted with U46619 and
treated with indomethacin (3 microM) and N(G)-nitro-L-arginine (L-NOARG; 100
microM), relaxation to BK (0.01 nM-0.3 microM) was blocked by approximately 60%
after inhibition of K(+) channels with either high extracellular K(+) (high
[K(+)](o); 15 - 67 mM) or apamin (0.3 microM). Ouabain (1 microM), an inhibitor
of Na(+)/K(+)-ATPase, decreased the sensitivity to BK without affecting the
maximum response. In L-NOARG-treated rings, ouabain had no further effect on the
relaxation to BK. An inhibitor of inward-rectifying K(+) channels, Ba(2+) (30
microM), had no effect on relaxations to BK in the absence or presence of either
L-NOARG or ouabain. KCl (2.5 - 10 mM) elicited small relaxations ( approximately
20%) that were abolished by nifedipine (0.3 microM) and ouabain. Both the high
[K(+)](o)/apamin-sensitive relaxation to BK, and the relaxation to the K(ATP)
channel-opener, levcromakalim (0.6 microM), were unaffected by the cytochrome
P(450) inhibitor, 7-ethoxyresorufin (10 microM), or by co-treatment with a
phospholipase A(2) inhibitor, arachidonyl trifluoromethyl ketone (AACOCF(3); 3
microM) and a diacylglycerol (DAG)-lipase inhibitor, 1, 6-bis
(cyclohexyloximinocarbonylamino)-hexane (RHC 80267; 30 microM). The non-NO/high
[K(+)](o)-insensitive, approximately 40% relaxation to BK was, however, abolished
by these treatments. Therefore, neither cytochrome P(450)-derived metabolites of
arachidonic acid nor K(+) appear to mediate the EDHF-like relaxation to BK (i.e
the non-NO, high [K(+)](o)/apamin-sensitive component) in bovine coronary
arteries. Cytochrome P(450)-derived metabolites may be released at higher BK
concentrations to act in parallel with NO and the high [K(+)](o)/apamin-sensitive
mechanism.
PMID- 10683208
TI - Overview of infection control problems: principles in gastrointestinal endoscopy.
AB - The practice of flexible gastrointestinal endoscopy has matured significantly in
recent years. Unfortunately, two long-standing problems still exist: the complex
physical nature inherent to the endoscopes and accessories, and user compliance
with established reprocessing guidelines. Improvements have been made, but newer
instruments remain comparatively fragile, expensive, and physically complex, and
validated data on reprocessing specific instruments is generally lacking. The
practice of flexible gastrointestinal endoscopy today, however, is demonstrably
safe and beneficial, provided established practice procedures for reprocessing,
with emphasis on instrument cleaning, are followed meticulously in each endoscopy
center.
PMID- 10683209
TI - Infectious complications associated with gastrointestinal endoscopy.
AB - Infectious complications resulting from endoscopy rarely occur. This is probably
due as much to the efficiency of the gastrointestinal immune system as to
effective endoscope disinfection practices. The low incidence may also represent
the difficulty linking infections to endoscopy. Recent reports of probable
interpersonal transmission of hepatitis C infection during colonoscopy has
heightened this concern. This article examines the documented cases of endoscopy
related infections and reviews the risk factors for these infections and details
guidelines which have been designed to keep the incidence of these complications
low.
PMID- 10683210
TI - The microbial flora of the gastrointestinal tract and the cleaning of flexible
endoscopes.
AB - Technologic advances in the last 30 years have resulted in the development of
complex, expensive, and heat sensitive medical instrumentation, including
flexible gastrointestinal endoscopes. Because of the design complexity and the
region of use, gastrointestinal endoscopes present special challenges to
cleaning. If instruments are not properly cleaned the disinfection or
sterilization procedure can fail and increase the possibility of infection
transmission from one patient to another. Although the cleaning process removes
intestinal microflora, the washing process itself may introduce a saprophytic or
environmental microbial flora. It has been repeatedly shown that endoscope
cleaning, not the disinfection or sterilization procedure, controls the success
of the reprocessing procedure.
PMID- 10683211
TI - Automatic flexible endoscope reprocessors.
AB - Reprocessing medical instruments is a complex and controversial discipline. If
all instruments were constructed of materials not damaged by heat, pressure, and
moisture, instrument reprocessing would be greatly simplified. As the number of
novel and complex instruments entering the market continues to increase, periodic
review of the health care facility's instrument reprocessing protocols to ensure
their safety and effectiveness is important. This article reviews the advantages
and the limitations of automatic flexible endoscope reprocessors.
PMID- 10683212
TI - FDA guidelines for endoscope reprocessing.
AB - The Food and Drug Administration (FDA) relies on guidance documents, such as
voluntary consensus standards and professional practice standards when reviewing
the manufacturer's endoscope reprocessing instructions included in the
instructions for use manual. The FDA does not perform endoscope reprocessing
validation studies. The device manufacturer must certify that the reprocessing
instructions included in the user manual have been or will be validated. This
article discusses the regulatory review of gastrointestinal endoscopes and
endoscope reprocessing instructions required prior to marketing.
PMID- 10683213
TI - American Society for Gastrointestinal Endoscopy-Society of Gastroenterology
Nurses and Associates Endoscope Reprocessing Guidelines.
AB - Adequate endoscope reprocessing is one of the most essential functions in any
endoscopy setting. Standards and guidelines for reprocessing endoscopes have been
established by the Society of Gastroenterology Nurses and Associates (SGNA) and
the American Society for Gastrointestinal Endoscopy (ASGE). These standards
pertain to any setting in which gastrointestinal endoscopy is performed.
Endoscope reprocessing that meets the established standard of practice helps to
ensure a patient-ready instrument for all patients, reduces the risk of disease
transmission to practitioners and staff, and helps to prolong the life of the
endoscope.
PMID- 10683214
TI - Reconciliation of FDA and societal guidelines for endoscope reprocessing.
AB - Chemical sterilants are used to high-level disinfect semicritical medical devices
such as flexible endoscopes. For the chemosterilant to obtain a high level
disinfection claim, The Food and Drug Administration requires demonstration of a
6-log reduction of myobacterial inoculum under worst case conditions (2% horse
serum added to test sterilant). This testing requirement has led to label product
claims of 45 minutes immersion times at 25 degrees C. Review of the scientific
data suggests that at least an 8-log reduction in contamination with thorough
instrument cleaning, followed by chemical disinfection for 20 minutes immersion
at 20 degrees C will achieve high-level disinfection.
PMID- 10683215
TI - Noncompliance with FDA and society guidelines for endoscopic reprocessing:
implications for patient care.
AB - Flexible endoscopic instruments are very valuable in the diagnosis and treatment
of patients with gastrointestinal diseases. Current guidelines for reprocessing
these instruments between patient use are appropriate. Rigid adherence to these
guidelines, however, will be necessary to reassure governmental authorities,
other medical authorities, and the public that the risk of infection from these
procedures is minimal.
PMID- 10683216
TI - Non-United States guidelines for endoscope reprocessing.
AB - A worldwide concern has emerged with regard to endoscope disinfection, and many
gastrointestinal endoscopy associations have guidelines for proper disinfection
of endoscopes and endoscopic accessories. They are not much different from those
of the American Society of Gastrointestinal Endoscopy and include mechanical
cleaning as the first and most important step followed by immersion in 2%
glutaraldehyde for periods ranging from 5 to 20 minutes. Lack of compliance with
these guidelines has been noted, however, in 20 to 70% of centers in Europe, the
United Kingdom, Australia, and Asia. Automated disinfectors are being universally
recommended to ensure better compliance. Two other improvements are use of
peracetic acid as an alternative disinfectant and use of a disposable sheath over
the endoscope.
PMID- 10683217
TI - Newer technologies for endoscope disinfection: electrolyzed acid water and
disposable-component endoscope systems.
AB - Novel technologies have been designed to improve or replace more conventional
methods of endoscope disinfection. Electrolyzed acid water has the potential to
decrease the time, toxicity, and cost of endoscope disinfection. Disposable
component endoscope systems have the potential to improve the ease of cleaning
and disinfection, or eliminate the need altogether.
PMID- 10683218
TI - Overview of the problem: reprocessing versus disposal of endoscopic accessories.
AB - The decision to reuse or not reuse endoscopic accessories appears simple on the
surface. Further reflection, however, reveals that the decision to purchase
reusable accessories or reuse disposable accessories is complex and
controversial. This article clarifies key issues surrounding the use of
disposable and reusable endoscopic accessories. Discussion includes the
advantages and disadvantages of disposable and reusable accessories, the issues
surrounding reprocessing of reusable equipment, and the issues surrounding the
reuse of disposable accessories.
PMID- 10683219
TI - Advantages of disposable endoscopic accessories.
AB - Despite the prevailing emphasis on falling reimbursements and cost containment,
the use of disposable endoscopic accessories has grown tremendously. They offer
simplicity of use, certain sterility, and reduced labor costs in exchange for
higher purchase costs per procedure and the burden of waste disposal. Disposable
accessories provide greater variety, complexity, and utility. They carry a cost
burden that may be acceptable when the devices are difficult to reprocess, when
they incorporate features that justify the added cost, or when their unit cost
approaches purchase plus reprocessing costs for reusable alternatives, such as
for biopsy forceps. Units with small volumes may prefer the ease of disposable
accessories independent of relative cost issues, while large high-volume units
may need to evaluate cost data more carefully to maintain sustainable practices.
PMID- 10683220
TI - Advantages of reusable accessories.
AB - Despite scant evidence supporting the use of disposable accessories, these
devices have been widely disseminated. Manufacturers and governmental regulators,
the most devout proponents of one-time use accessories, have framed the issue in
economic terms-parsimonious practitioners reusing disposable accessories at the
risk of cross-contamination, mechanical failure and product liability. This
simplistic view represents revisionist history and ignores the long tradition of
reusing these devices. This article reviews the numerous studies that support the
safe and cost effective reuse of disposable and reusable accessories.
PMID- 10683221
TI - Methodology of reprocessing reusable accessories.
AB - Accessory devices used for gastrointestinal endoscopy are often complex and
because they enter sterile body cavities, or contact blood because of invasive
procedures, they should be sterile before being used for a patient procedure. The
complexity of such reusable accessory devices is reviewed, and the critical
aspects of cleaning, sterilization, and quality assurance are discussed. The
effectiveness of adequate reprocessing between patient use is critical to prevent
transmission of infectious diseases from one patient to another.
PMID- 10683222
TI - Methodology of reprocessing one-time use accessories.
AB - The current climate of falling reimbursements has prompted evaluation of reusing
single use (disposable) endoscopic accessories. A number of different accessories
have undergone study of both function and sterility after reuse. These studies,
albeit limited in number, do show that selected equipment can be sterilized
without impairment of function. Nonetheless, despite the data, widespread
adoption of accessory reuse remains hampered by lingering concerns over cross
contamination and medical and legal risks.
PMID- 10683223
TI - Third-party reprocessing of endoscopic accessories.
AB - Third-party reprocessing of medical devices labeled for single use is a safe, FDA
regulated practice that helps hospitals reduce costs without compromising patient
care. Simply because a device is labeled as single use does not mean it cannot be
safely reprocessed. To the contrary, the single use label is chosen by the
manufacturer, sometimes for economic gain, as there are no formal FDA regulations
or standards to distinguish between reusable and single use devices. The current
FDA regulatory framework for third-party reprocessors, which emphasizes
compliance with FDA quality assurance requirements, is presently under review,
and the agency is in the process of developing a new regulatory scheme for
reprocessing.
PMID- 10683224
TI - A method for application of samples to matrix-assisted laser desorption
ionization time-of-flight targets that enhances peptide detection.
AB - Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass
spectrometry has become a fundamental tool for the identification and analysis of
peptides and proteins. MALDI-TOF is well suited for the analysis of complex
biological mixtures because samples are crystallized onto a solid support that
can be washed to remove contaminants and salts prior to laser desorption. A
number of approaches for immobilizing samples onto MALDI targets have been put
forth. These include the use of different chemical matrices and the
immobilization of samples onto different solid supports. In large part though,
the preparation of MALDI targets has been an empirical exercise that often
requires a unique series of conditions for every sample. Here, a simple method
for the application of peptide mixtures onto MALDI targets is put forth. This
method differs because peptides are added directly to a sample of nitrocellulose
dissolved in acetone, allowing them to interact in solution-phase organic
solvent. This solution-phase mixture is then spotted to the MALDI target and
evaporated, forming a homogenous solid surface for laser desorption. This
procedure is robust, highly sensitive, tolerant to detergents, and easily
learned. In our hands, the method provides as much as a 10-fold enhancement to
the detection of tryptic peptide fragments derived from in-gel digests.
PMID- 10683226
TI - Separation of lipooligosaccharides by linear gradient gel electrophoresis.
AB - Lipooligosaccharides (LOSs) are one of the major antigenic and immunogenic
components on the outer membrane of mucosal Gram-negative bacteria. These
glycolipid antigens are in the M(r) range of 3-7 kDa, and SDS/PAGE has been used
as an analytical tool. Although we are able to separate relatively higher M(r)
LOS components by mini-PAGE, we encounter difficulties in resolving LOS
components below 3.6 kDa present in heterogeneous LOS preparations. In the
present study, we selected PID2 LOS consisting of six LOS components of 3.0-5.1
kDa as a model LOS and examined mini-PAGE conditions not only to resolve smaller
M(r) LOS components but also to retain resolving capability of higher LOS
components. We found that mini-PAGE with stepwise and linear gradient gels
(glycine-SDS) resolved smaller M(r) LOS components. Mini-PAGE with linear
gradient gels gave the best resolution, and LOS components of 3.0-5.1 kDa were
separated as tight and even bands. Because of the resolution, LOS components were
stained chemically and immunochemically much better than those on continuous or
stepwise gradient gels. Our study also showed that preformed tricine-SDS (TSDS)
minigels such as 16.5 and 10-20% (linear gradient) did not resolve PID2 LOS,
which indicated that heterogeneous LOS preparations may not be fully analyzed by
using these TSDS minigels. By using glycine-SDS linear gradient mini-PAGE, we
should be able not only to screen expression of LOSs but also to characterize
smaller M(r) LOS components present in heterogeneous LOS preparations whose
identities may have been neglected in the past.
PMID- 10683225
TI - Tubulin carboxypeptidase assay based on the action of the enzyme on
[14C]tyrosinated tubulin bound to nitrocellulose membrane.
AB - We have developed a method for the determination of tubulin carboxypeptidase
activity which is based on the action of the enzyme on the substrate,
[14C]tyrosinated tubulin, previously adsorbed on nitrocellulose membrane. In
addition to being two to three times more sensitive than previous
carboxypeptidase assays, this method allows the determination of dilute enzyme
preparations even containing high salt (inhibitory) concentrations. This is a
valuable property specially under circumstances in which numerous high salt
containing fractions with scarce activity should be analyzed (for example after
certain chromatographic stages during enzyme purification). Our method is
simpler, less time-consuming, and suitable for multiple, simultaneous
determinations and the substrate bound to nitrocellulose can be stored for
several months without significant alteration of its properties. Peptidases other
than tubulin carboxypeptidase can act on [14C]tyrosinated tubulin bound to
nitrocellulose, solubilizing radioactive compounds, suggesting the eventual
applicability of this method to assay proteases in general. Other features and
advantages of the assay as well as its limitations are discussed.
PMID- 10683227
TI - Characterization of ricin heterogeneity by electrospray mass spectrometry,
capillary electrophoresis, and resonant mirror.
AB - Electrospray mass spectrometry (ES/MS), capillary-zone electrophoresis (CZE),
capillary isoelectric focusing (CIEF), and multianalyte resonant mirror are used
to evaluate the heterogeneity of samples of ricin toxins extracted from five
horticultural varieties of Ricinus communis seeds: R. communis zanzibariensis,
carmencita, impala, sanguineus, and gibsonii. The investigation is also extended
to the geographical provenance of the beans. Combining mass spectrometry, CE
techniques, and resonant mirror results in a powerful analytical tool capable to
characterize and differentiate between different varieties of ricin toxins. Each
technique complements the others, adding another level of information. This study
reveals a large extent of heterogeneity for each cultivar, demonstrating that
ricin toxins consist of a series of glycosylated proteins most likely originating
from a multigene family. By combining these techniques, it is possible to
differentiate between zanzibariensis and the other four varieties, and that
variations in the functional characteristics may be observed between the
different cultivars. This study demonstrates that knowledge of the variety of R.
communis beans used and their geographical provenance is essential before any
type of investigation of ricin toxins is carried out. Consequently, any unusual
behavior observed can only be attributed to that particular cultivar studied and
not automatically extended to include all R. communis varieties.
PMID- 10683228
TI - High-performance capillary electrophoresis of sialylated oligosaccharides of
human milk.
AB - Oligosaccharides in human milk inhibit enteric pathogens in vitro and in vivo.
Neutral milk oligosaccharides vary among individuals and over the course of
lactation. To study such variation in the acidic milk oligosaccharides, a
sensitive, convenient, quantitative method is needed. High-performance capillary
electrophoresis of underivatized acidic oligosaccharides with detection by UV
absorbance at 205 nm proved to be sensitive to the femtomole level. Eleven
standard oligosaccharides ranging from tri- to nonasaccharide (3'-sialyllactose,
6'-sialyllactose, 3'-sialyllactosamine, 6'-sialyllactosamine, disialyltetraose,
3'-sialyl-3-fucosyllactose, sialyllacto-N-tetraose-a, sialyllacto-N-tetraose-b,
sialyllacto-N-neotetraose-c, disialyllacto-N-tetraose, and
disialomonofucosyllacto-N-neohexaose) were resolved; baseline resolutions of 3'
sialyllactose, 6'-sialyllactose, and other structural isomers were achieved. Peak
areas were linear from 30 to 2000 pg and were reproducible with a coefficient of
variation between 4 and 9%. There was no evidence of quantitative interference of
one oligosaccharide with another. In studies using pooled human milk, addition of
increasing amounts of authentic standard oligosaccharides produced the expected
positive increments in detected values, indicating quantitative recovery without
interference by other milk components. The identities of the major sialylated
acidic oligosaccharides of pooled human milk agreed with the results of previous
studies employing other analytical methods. Comparison of oligosaccharide
profiles of milk samples from different donors revealed extensive variation,
especially in the structural isomers of sialyllacto-N-tetraose. This sensitive,
highly reproducible method requires only simple sample workup and is useful in
defining variations in human milk acidic oligosaccharides and investigating their
possible relationship with diseases of infants.
PMID- 10683229
TI - Development of an offline noncompetitive flow immunoassay for the determination
of interleukin-8 in cell samples.
AB - A noncompetitive flow immunoassay system (FIA) for the analysis of interleukin-8
(IL-8) in cell samples was developed. Affinity interaction assays based on
offline incubation of excess labeled antibodies and antigen (IL-8) were carried
out. The residual unbound labeled antibody was trapped in an immunoaffinity
column with immobilized IL-8 while the immunocomplex, labeled antibody/IL-8, was
detected by a fluorescence detector. Two fluorophores, FLUOS and Cy5.5, were
conjugated with IL-8 antibody. Optimization and comparison between the two
fluorescent labeled antibodies were performed with regard to pH, antibody
concentration, flow rate, injection volume, and association time. Additionally, a
horseradish peroxidase enzyme label was used for the conjugation to the anti-IL
8. The enzyme substrate reaction was optimized with respect to temperature and
length of the substrate reaction coil. The detection limits were found to be 200
amol using the FLUOS-labeled anti-IL-8 and 1 fmol using the Cy5.5 fluorescence
label. The developed FIA technique was applied for the analysis of IL-8 in cell
samples. Matrix-assisted laser desorption/ionization time-of-flight mass
spectrometry was used to identify IL-8 in the cell samples.
PMID- 10683230
TI - Evaluation of methods for the determination of mitochondrial respiratory chain
enzyme activities in human skeletal muscle samples.
AB - The quantification of mitochondrial enzyme activities in skeletal muscle samples
of patients suspected of having mitochondrial myopathies is problematic.
Therefore, we have evaluated different methods for the determination of
activities cytochrome c oxidase and NADH:CoQ oxidoreductase in human skeletal
muscle samples. The measurement of cytochrome c oxidase activity in the presence
of 200 microM ferrocytochrome c and the detection of NADH:CoQ oxidoreductase as
rotenone-sensitive NADH:CoQ(1) reductase resulted in comparable citrate synthase
normalized respiratory chain enzyme activities of both isolated mitochondria and
homogenates from control human skeletal muscle samples. These methods allowed the
precise detection of deficiencies of respiratory chain enzymes in skeletal muscle
of two patients harboring only 20 and 27% of deleted mitochondrial DNA,
respectively. Therefore, citrate synthase-normalized respiratory chain activities
can serve as stable reference values for the determination of a putative
mitochondrial defect in human skeletal muscle.
PMID- 10683231
TI - Kinetic analysis of the mass transport limited interaction between the tyrosine
kinase lck SH2 domain and a phosphorylated peptide studied by a new cuvette-based
surface plasmon resonance instrument.
AB - We explored the use of a newly developed cuvette-based surface plasmon resonance
(SPR) instrument (IBIS) to study peptide-protein interactions. We studied the
interaction between the SH2 domain of lck and a phosphotyrosine peptide
EPQY*EEIPIYL which was immobilized on a sensor chip. No indications for mass
transport limitation (MTL) were observed when standard kinetic approaches were
used. However, addition of competing peptide during dissociation revealed a high
extent of rebinding. A dissociation rate constant (k(d)) of 0.6+/-0.1 s(-1) was
obtained in the presence of large amounts of peptide. A simple bimolecular
binding model, applying second-order kinetics for the cuvette system, could not
adequately describe the data. Fits were improved upon including a step in the
model which describes diffusion of the SH2 domain from the bulk to the sensor,
especially for a surface with high binding capacity. From experiments in glycerol
containing buffers, it appeared that the diffusion rate decreased with higher
viscosity. It is demonstrated that MTL during association and dissociation can be
described by the same diffusion rate. A binding constant (K(D)) of 5.9+/-0.8 nM
was obtained from the SPR equilibrium signals by fitting to a Langmuir binding
isotherm, with correction for loss of free analyte due to binding. An association
rate constant k(a) of 1.1(+/-0.2)x10(8) M(-1) x s(-1) was obtained from
k(d)/K(D). The values for k(a) and k(d) obtained in this way were 2-3 orders
larger than that from standard kinetic analysis, ignoring MTL. We conclude that
in a cuvette the extent of MTL is comparable to that in a flow system.
PMID- 10683232
TI - Kinetic analysis of the interaction between HIV-1 protease and inhibitors using
optical biosensor technology.
AB - The interaction between HIV-1 protease and reversible inhibitors was studied by
surface plasmon resonance biosensor technology. The steady-state binding level
and the time course of association and dissociation could be observed by
measuring the binding of inhibitors injected in a continuous flow of buffer to
the immobilized enzyme. Fourteen low molecular weight inhibitors (500-700 Da),
including the four clinically used HIV-1 protease inhibitors (indinavir,
nelfinavir, ritonavir, and saquinavir), were analyzed. Affinities were estimated
as B(50) values from a series of sensorgrams at different concentrations of
inhibitors. These values were found to be correlated with inhibition constants
(K(i)) determined by an enzyme inhibition assay (r(2) = 0.84, logarithmic
values). Dissociation rates were estimated at a single saturating concentration
of the inhibitors as t(1/2,obs), but these values did not correlate with K(i)
(r(2) = 0.26, logarithmic values). Indinavir had the highest affinity (B(50) = 11
nM) and the fastest dissociation (t(1/2,obs) = 500 s) among the clinically used
inhibitors while saquinavir had a lower affinity (B(50) = 25 nM) and the slowest
dissociation rate (t(1/2,obs) = 6500 s). Since these two inhibitors have similar
K(i) values, the differences in dissociation rates reveal important
characteristics in the interaction that cannot be obtained by the inhibition
studies. The biosensor data are expected to be of greater in vivo relevance since
the experiments were performed in a buffer more similar to physiological
conditions.
PMID- 10683233
TI - Separation of Galfbeta1-->XGlcNAc and Galpbeta1-->XGlcNAc (X = 3, 4, and 6) as
the alditols by high-pH anion-exchange chromatography and thin-layer
chromatography: characterization of mucins from Trypanosoma cruzi.
AB - The O-linked N-acetylglucosamine oligosaccharides in the mucins of Trypanosoma
cruzi may contain galactofuranose or galactopyranose, depending on the strain,
one of the components being the disaccharide. Since galactofuranose is a site for
antibody recognition, it is desirable to have a sensitive method for the
detection of the galactofuranosyl structures. In this paper, we present
procedures for the separation of Galfbeta1-->XGlcNAc and Galpbeta1-->XGlcNAc (X =
3, 4, and 6) as the corresponding alditols by high-pH anion-exchange
chromatography with pulse amperometric detection. All the isomeric disaccharides
could be resolved on a CarboPac PA-10 column, the galactofuranose-containing
disaccharides being more retained in the column. GlcNAcol and Galfbeta1-
>4(Galpbeta1-->6)GlcNAcol could be analyzed in the same run. The compounds could
also be separated by thin-layer chromatography on silica gel 60, a convenient
method for analysis of the radiolabeled alditols obtained by reductive beta
elimination in the presence of NaB(3)H(4). Both methods were applied for the
analysis of the O-linked sugars in the mucins of T. cruzi CL 14 and revealed that
they contained only N-acetylglucosamine and the disaccharide Galpbeta1-->4GlcNAc.
PMID- 10683234
TI - A spectrophotometric method for assay of tannase using rhodanine.
AB - A method for assay of microbial tannase (tannin acyl hydrolase) based on the
formation of chromogen between gallic acid and rhodanine is reported. Unlike the
previous protocols, this method is sensitive up to gallic acid concentration of 5
nmol and has a precision of 1.7% (relative standard deviation). The assay is
complete in a short time, very convenient, and reproducible.
PMID- 10683235
TI - Resolution of glycoproteins by a lectin gel-shift assay.
AB - Gel-shift assays previously described in the literature are based on protein
protein or protein-DNA interactions. We show that carbohydrate-lectin
interactions can be successfully used to alter the electrophoretic mobility of
glycosylated, but not nonglycosylated, protein species in SDS-polyacrylamide
gels. We were able to separate the two closely migrating mono- (95 kDa) and
nonglycosylated (92 kDa) forms of a polytopic membrane protein, anion exchanger 1
(AE1), synthesized by cell-free translation or in transfected HEK293 cells.
Concanavalin A was selected as the lectin due to the high mannose content of the
oligosaccharide chain on AE1. Concanavalin A was either added to the samples
prior to loading or copolymerized in a top layer of the separating gel, the
latter being the method of choice. The presence of concanavalin A resulted in
slower mobility of the monoglycosylated protein while the mobility of the
nonglycosylated form was not altered. The shift in mobility was dependent on
concentration of concanavalin A and the length of separating gel containing
copolymerized concanavalin A. When a diglycosylated mutant of AE1 was tested,
good separation was achieved at lower concentrations of concanavalin A. This
lectin gel-shift assay allows the separation of N-glycosylated and
nonglycosylated forms of the protein.
PMID- 10683236
TI - A complete system for identifying inhibitors of creatine kinase B.
AB - We have developed a complete system for discovery of lead compounds as inhibitors
of creatine kinase B. In this article, we describe production and purification of
the recombinant protein, conditions and features of an optimized high-throughput
screening assay, and results of our implementation of the system using a diverse
compound library.
PMID- 10683237
TI - Pulsed high-field gradient in vivo NMR spectroscopy to measure diffusional water
permeability in Corynebacterium glutamicum.
AB - Pulsed high-field gradient in vivo NMR spectroscopy was used to measure
diffusional water permeability in cell suspensions of the Gram-positive bacterium
Corynebacterium glutamicum. Two different regions of H2O mobility were detected.
One was characterized by the apparent coefficient of self-diffusion, D(1 app) =
(4.6-12.7)x10(-8) cm(2) s(-1), depending on the observation time t. The other
region was characterized by D(2) = 1.4x10(-5) cm(2) s(-1). The value of D(2) was
similar to the diffusion coefficient of H2O in free water and in extracellular
biological fluids. Restricted diffusion could be demonstrated for the slower
process (D(1)). It was attributed to the cytoplasm of the cells. The membrane
permeability, P(d H2O), for C. glutamicum was (4.8+/-0.4)x10(-3) cm s(-1). It
compared favorably with values reported for human erythrocytes and was higher by
a factor of about 100 compared to the diffusional permeability for ethanol, P(d
ethanol), in Zymomonas mobilis. Addition of HgCl2, a water channel inhibitor in
eukaryotes, decreased P(d H2O) in C. glutamicum by a factor of approximately 8.
To our knowledge, these are the first functional studies of water transport in
prokaryotes that yielded quantitative data, viz., transmembrane water
permeability expressed through D(H2O) and P(d H2O).
PMID- 10683238
TI - Determination of pineal melatonin by precolumn derivatization reversed-phase high
performance liquid chromatography and its application to the study of circadian
rhythm in rats and mice.
AB - Determination of minute amounts of endogenous melatonin in rat and mouse pineal
gland was performed using an RP-HPLC system. Melatonin was separated following
precolumn derivatization and determined with a fluorescence detector at the
emission wavelength of 380 nm with the excitation at 245 nm. The calibration
curve of melatonin constructed by adding known amounts of melatonin to the
homogenates of mouse pineal gland was linear over the range of 1-500 fmol
(injection amount/20 microl). The detection limit of added melatonin was 1 fmol
(S/N = 5). Repeatability and day-to-day precision for the melatonin spiked sample
of mouse pineal gland was 4.0 and 3.8% (RSD), respectively. Using the present
method, circadian changes of melatonin content in rat (Wistar) and mouse (C3H)
pineal gland were determined. In addition, a minute amount of melatonin in ddY
mouse pineal gland was determined, because pineal melatonin of many inbred mouse
strains has been reported to be lower than the detection limit.
PMID- 10683239
TI - Optimal use of the fluorescent PicoGreen dye for quantitative analysis of
amplified polymerase chain reaction products on microplate.
PMID- 10683240
TI - Evaluation of subtilisin cleavage specificity for RNase A peptide bonds by high
performance liquid chromatography and mass spectrometric analysis.
PMID- 10683241
TI - Degenerate oligonucleotide-primed preamplification of ancient DNA allows the
retrieval of authentic DNA sequences.
PMID- 10683242
TI - Alkaline treatment after X-Gal staining reaction for Escherichia coli beta
galactosidase enhances sensitivity.
PMID- 10683243
TI - Decreased expression of adenosine kinase in streptozotocin-induced diabetes
mellitus rats.
AB - Adenosine has been implicated as an important endogenous regulator of various
tissue functions. In diabetes, the responsiveness of several tissues to adenosine
is altered. The aim of this study was to investigate the activities of enzymes
metabolizing adenosine in tissues of diabetic rats. The cytosolic activity
(V(max)) of adenosine kinase (AK) was decreased by 50% in the kidney and by 40%
in the heart and liver of diabetic rats. A decrease in the V(max) of AK in
diabetic tissues was not associated with a change in the K(m) for adenosine.
Evaluation of AK gene transcript status showed significantly lower levels of AK
mRNA in diabetic tissues as compared to normal tissues. In diabetic kidneys, the
level of AK gene transcript was lowered by 50% on first day after streptozotocin
administration, and these reduced levels were sustained declined during the next
10 days. Smaller changes in AK gene transcript levels were observed in the heart
and liver than in the kidney. The cytosolic activities of 5'-nucleotidase, AMP
deaminase, and adenosine deaminase were unchanged in kidney, heart, and liver of
diabetic rats. These results suggest that the turnover of the AMP-adenosine
metabolic cycle might be impaired in diabetic tissues due to the reduced activity
of adenosine kinase.
PMID- 10683244
TI - Cystic fibrosis transmembrane conductance regulator: the purified NBF1+R protein
interacts with the purified NBF2 domain to form a stable NBF1+R/NBF2 complex
while inducing a conformational change transmitted to the C-terminal region.
AB - The cystic fibrosis transmembrane conductance regulator (CFTR) is known to
function as a regulated chloride channel and, when genetically impaired, to cause
the disease cystic fibrosis. The novel studies reported here were undertaken to
gain greater molecular insight into possible interactions among CFTR's soluble
domains, which include two nucleotide binding domains (NBF1 and NBF2) and a
regulatory domain (R). The NBF1+R and NBF2 regions of CFTR were highly expressed
in Escherichia coli, purified to near homogeneity under denaturing conditions,
and refolded. Both refolded proteins bound TNP-ATP and TNP-ADP, which could be
readily replaced with ATP. Four different approaches were then used to determine
whether the NBF1+R and NBF2 proteins interact. First, the purified NBF2 protein
was labeled near its C-terminus with a fluorescent probe, 7-diethyl amino-3-(4'
maleimidylphenyl)-4-methylcoumarin (CPM). Addition of the unlabeled NBF1+R to the
CPM-labeled NBF2 caused a red-shift in lambda(max) of the CPM fluorescence,
consistent with a direct interaction between the two proteins. Second, when the
NBF1+R protein, the NBF2 protein, and a mixture of the two proteins were folded
separately and analyzed by molecular sieve chomatography, the mixture was found
to elute prior to either NBF1+R or NBF2. Third, na-tive-PAGE gel studies revealed
that the mixture of the NBF1+R and NBF2 domains migrated as a single band with an
R(F) value between that of NBF1+R and NBF2. Fourth, trypsin digestion of a
mixture of the NBF1+R and NBF2 proteins occurred at a slower rate than that for
the individual proteins. Finally, studies were carried out to determine whether
an NBF1+R/NBF2 interaction could be demonstrated after expressing one of the two
proteins in soluble, native form, thus avoiding the inclusion body, denaturation,
and renaturation approach. Specifically, the NBF1+R protein was overexpressed in
E. coli in fusion with glutathione-S-transferase near a thrombin cleavage site.
Following binding of the GST-(NBF1+R) fusion protein to a GST Sepharose affinity
column, added NBF2 was shown to bind and then to coelute with NBF1+R upon
addition of glutathione or thrombin. Collectively, these experiments demonstrate
that CFTR's NBF1+R region and its NBF2 domain, after folding separately as
distinct units, have a strong propensity to interact and that this interaction is
stable in the absence of added nucleotides or exogenously induced
phosphorylation. These findings, together with the additional observation that
the NBF1+R/NBF2 interaction induces a change in the C-terminus of NBF2, which
resides within the C-terminal region of CFTR, may have important implications not
only for the function of CFTR per se, but its interaction with other proteins.
PMID- 10683245
TI - Substrate oxidation and ATP supply in AS-30D hepatoma cells.
AB - The oxidation of several metabolites in AS-30D tumor cells was determined.
Glucose and glycogen consumption and lactic acid production showed high rates,
indicating a high glycolytic activity. The utilization of ketone bodies,
oxidation of endogenous glutamate, and oxidative phosphorylation were also very
active: tumor cells showed a high respiration rate (100 ng atoms oxygen (min x
10(7) cells)(-1)), which was 90% oligomycin-sensitive. AS-30D tumor cells
underwent significant intracellular volume changes, which preserved high
concentrations of several metabolites. A high O(2) concentration, but a low
glucose concentration were found in the cell-free ascites liquid. Glutamine was
the oxidizable substrate found at the highest concentration in the ascites
liquid. We estimated that cellular ATP was mainly provided by oxidative
phosphorylation. These data indicated that AS-30D hepatoma cells had a
predominantly oxidative and not a glycolytic type of metabolism. The NADH
ubiquinol oxido reductase and the enzyme block for ATP utilization were the sites
that exerted most of the control of oxidative phosphorylation (flux control
coefficient = 0.3-0.42).
PMID- 10683246
TI - Homology models of mu-opioid receptor with organic and inorganic cations at
conserved aspartates in the second and third transmembrane domains.
AB - Metal ions affect ligand binding to G-protein-coupled receptors by as yet unknown
mechanisms. In particular, Na(+) increases the affinity for antagonists but
decreases it for agonists. We had modeled the mu-opioid receptor (muR) based on
the low-resolution structure of rhodopsin by G. F. X. Schertler, C. Villa, and R.
Henderson (1993, Nature 362, 770-772) and proposed that metal ions may be
directly involved in the binding of ligands and receptor activation (B. S. Zhorov
and V. S. Ananthanarayanan, 1998, J. Biomol. Struct. Dyn. 15, 631-637).
Developing this concept further, we present here homology models of muR using as
templates the structure of rhodopsin elaborated by I. D. Pogozheva, A. L. Lomize,
and H. I. Mosberg (1997, Biophys. J. 70, 1963-1985) and J. M. Baldwin, G. F. X.
Schertler, and V. M. Unger (1997, J. Mol. Biol., 272, 144-164). Using the Monte
Carlo minimization (MCM) method, we docked the Na(+)-bound forms of muR ligands:
naloxone, bremazocine, and carfentanyl. The resultant low-energy complexes showed
that the two positive charges in the protonated metal-bound ligands interact with
the two negative charges at Asp(3.32) and Asp(2.50) (for notations, see J. A.
Ballesteros and H. Weinstein, 1995, Methods Neurosci. 25, 366-426). MCM
computation on morphine docked inside the model of muR by I. D. Pogozheva, A. L.
Lomize, and H. I. Mosberg (1998, Biophys. J. 75, 612-634) yielded two binding
modes with the ligand's ammonium group salt-bridged either to Asp(3.32)
(generally regarded as the ligand recognition site) or to Asp(2.50). The latter
is the presumed site for Na(+) ion, which is known to modulate ligand binding.
Assuming that in the low-dielectric transmembrane region of muR, organic and
inorganic cations would compete for Asp(3.32) and Asp(2.50), we propose that
ligand binding, as visualized in the above models, would first displace Na(+)
from Asp(3.32). A subsequent progress of the ligand toward Asp(2.50) would result
in either the retention of Na(+) at Asp(2.50) in the case of antagonists or the
displacement of Na(+) from Asp(2.50) in the case of agonists. The displaced Na(+)
would move toward the salt-bridged Asp(3.49)-Arg(3.50) and disengage the salt
bridge. This, in turn, would result in conformational changes at the cytoplasmic
face of the receptor that facilitate the interaction with the G-protein.
PMID- 10683247
TI - Hydrogen peroxide-mediated protein oxidation in young and old human MRC-5
fibroblasts.
AB - It is suggested that the aging process is dependent on the action of free
radicals. One of the highlights of age-related changes of cellular metabolism is
the accumulation of oxidized proteins. The present investigation was undertaken
to reveal the proliferation-related changes in the protein oxidation and
proteasome activity during and after an acute oxidative stress. It could be
demonstrated that the activity of the cytosolic proteasomal system declines
during proliferative senescence of human MRC-5 fibroblasts and is not able to
remove oxidized proteins in old cells efficiently. Whereas in young cells removal
of oxidized proteins was accompanied by an increase in the overall protein
turnover, this increase in protein turnover could not be seen in old MRC-5
fibroblasts. Therefore, our studies demonstrate that old fibroblasts are much
more vulnerable to the accumulation of oxidized proteins after oxidative stress
and are not able to remove these oxidized proteins as efficiently as young
fibroblasts.
PMID- 10683248
TI - Experimental hyperthyroidism causes inactivation of the branched-chain alpha
ketoacid dehydrogenase complex in rat liver.
AB - Hyperthyroidism induced by 3-day treatment of rats with thyroid hormone (T(3);
3,5,3'-triiodothyronine) at 0.1 or 1 mg/kg body wt/day resulted in a reduced
activity state (% of enzyme in its active, dephosphorylated state) of the hepatic
branched-chain alpha-ketoacid dehydrogenase (BCKDH) complex. One treatment with
0.1 mg T(3)/kg body wt caused a significant effect on the activity state of BCKDH
complex after 24 h, indicating that the reduction of the activity state was
triggered by the first administration of T(3). Hyperthyroidism also caused a
stable increase in BCKDH kinase activity, the enzyme responsible for
phosphorylation and inactivation of the BCKDH complex, suggesting that T(3)
caused inactivation of the BCKDH complex by induction of its kinase. Western blot
analysis also revealed increased amounts of BCKDH kinase protein in response to
hyperthyroidism. No change in the plasma levels of branched-chain alpha-keto
acids was observed in T(3)-treated rats, arguing against an involvement of these
known regulators of BCKDH kinase activity. Inactivation of the hepatic BCKDH
complex as a consequence of overexpression of its kinase may save the essential
branched-chain amino acids for protein synthesis during hyperthyroidism.
PMID- 10683249
TI - Characterization and partial purification of microsomal NAD(P)H:quinone
oxidoreductases.
AB - Quinone oxidoreductases are flavoproteins that catalyze two-electron reduction
and detoxification of quinones. This leads to the protection of cells against
toxicity, mutagenicity, and cancer due to exposure to environmental and synthetic
quinones and its precursors. Two cytosolic forms of quinone oxidoreductases
[NAD(P)H:quinone oxidoreductase 1 (NQO1) and NRH:quinone oxidoreductase 2 (NQO2)]
were previously identified, purified, and cloned. A role of cytosolic NQO1 in
protection of cells from oxidative stress, cytotoxicity, and mutagenicity of
quinones was established. Currently, we have characterized and partially purified
the NQO activity from rat liver microsomes. This activity was designated as
microsomal NQO (mNQO). The mNQO activity showed significantly higher affinity for
NADH than NADPH as electron donors and catalyzed reduction of 2,6
dichlorophenolindophenol and menadione. The mNQO activity was insensitive to
dicoumarol, a potent inhibitor of cytosolic NQO1. Western analysis of microsomal
proteins revealed 29- and 18-kDa bands that cross-reacted with polyclonal
antibodies raised against cytosolic NQO1. The mNQO activity was partially
purified by solubilization of microsomes with detergent Chaps, ammonium sulfate
fractionation, and DEAE-Sephacel column chromatography. The microsomal mNQO
proteins are expected to provide additional protection after cytosolic NQOs
against quinone toxicity and mutagenicity.
PMID- 10683250
TI - Sphingosine-1-phosphate activates phospholipase D in human airway epithelial
cells via a G protein-coupled receptor.
AB - Sphingosine-1-phosphate (SPP) acts as a first messenger in immortalized human
airway epithelial cells (CFNPE9o(-)), possibly interacting with an Edg family
receptor. Expression of the SPP receptors Edg-1 and Edg-3, as well as a low level
of Edg-5/H218, was detected in these cells, in agreement with their ability to
specifically bind SPP. The related lipids, lysophosphatidic acid and
sphingosylphosphorylcholine, were unable to displace SPP from its high affinity
binding sites, suggesting that the biological responses to these different
lysolipids are mediated by distinct receptors. SPP markedly inhibited forskolin
stimulated cAMP accumulation in a dose-dependent manner and caused a remarkable
elevation of intracellular calcium, both effects being sensitive to pertussis
toxin treatment. Most importantly, SPP stimulated phosphatidic acid formation,
which was maximal after 2 min and decreased within 8-10 min. In the presence of
butan-1-ol, suppression of SPP-induced phosphatidic acid formation and production
of phosphatidylbutanol were found, clearly indicating activation of phospholipase
D (PLD). This finding was also confirmed by analysis of the fatty acid
composition of phosphatidic acid, showing an increase in the monounsaturated
oleic acid only. The decrease of phosphatidic acid level after 8-10 min
incubation with SPP was accompanied by a parallel increase of diacylglycerol
production, which was abolished in the presence of butan-1-ol. This result
indicates that activation of phospholipase D is followed by stimulation of
phosphatidate phosphohydrolase activity. Phosphatidic acid formation was
insensitive to protein kinase C inhibitors and almost completely inhibited by
pertussis toxin treatment, suggesting that SPP activates phospholipase D via a
G(i/o) protein-coupled receptor.
PMID- 10683251
TI - A winged helix protein from yeast Saccharomyces cerevisiae recognizes centromere
sequences.
AB - The winged helix-turn-helix motif was initially identified in the mammalian
hepatocyte-enriched transcription factor HNF-3 and the Drosophila forkhead
homeotic protein. Proteins containing the winged helix motif have been shown to
play important roles in tissue-specific developmental regulation. In this report,
by using a genomic binding site selection method, we demonstrate that the winged
helix protein YFKH-1 from the yeast Saccharomyces cerevisiae recognizes conserved
sequence in yeast centromeres. Thus, our data suggest that the winged helix
proteins of the yeast may be involved in centromeric functions of the yeast.
PMID- 10683252
TI - Ribosomal stalk protein phosphorylating activities in Saccharomyces cerevisiae.
AB - With ribosomal P protein as a substrate, five peaks of protein kinase activity
are eluted after chromatography of a Saccharomyces cerevisiae cellular extract on
DEAE-cellulose. Two of them correspond to CK-II and the other three have been
called RAP-1, RAP-II, and RAP-III. RAP-I was previously characterized. RAP-III is
present in a very small amount, which hindered its purification. RAP-II was
further purified on phosphocellulose, heparin-Sepharose, and P protein-Sepharose,
studied in detail, and compared with other acidic protein kinases, including RAP
I, CK-II, and PK60. RAP-II is shown by SDS-PAGE and centrifugation on glycerol
linear density gradients to have a molecular mass of around 62 kDa and it is
immunologically different from RAP-I and PK60. RAP-II phosphorylates the P
proteins in the last serine residue at the highly conserved carboxyl terminal
domain as other P-protein kinases. The ribosome-bound stalk P proteins are not
equally phosphorylated by the different kinases. Thus, RAP-II and PK60 mainly
phosphorylate P1beta and P2alpha whereas RAP-I and CK-II modify all of them. A
comparative study of the K(m) and V(max) of the phosphorylation reaction by the
different kinases using individual purified acidic proteins suggests changes in
the substrate susceptibility upon binding to the ribosome. All the data available
reveal clear differences in the characteristics of the various P protein kinases
and suggest that the cell may use them to differentially modify the stalk
depending, perhaps, on metabolic requirements.
PMID- 10683253
TI - Expression of a 70-kDa immunoreactive form of bile salt-dependent lipase by human
pancreatic tumoral mia PaCa-2 cells.
AB - This work describes the characterization of an immunoreactive form of bile salt
dependent lipase (BSDL) expressed by the human pancreatic tumoral Mia PaCa-2 cell
line. This BSDL-related protein, which has an M(r) of 70 kDa, is enzymatically
active and poorly secreted. Furthermore, a protein with the same electrophoretic
migration can also be immunoprecipitated with polyclonal antibodies specific for
the human pancreatic BSDL after in vitro translation of RNA isolated from Mia
PaCa-2 cells. These data indicated that this BSDL-related protein might be
poorly, or not, glycosylated. Reverse transcription and amplification of RNA
extracted from Mia PaCa-2 cells using primers able to specifically amplify the
full-length mRNA of the human BSDL resulted in a detectable 1.8-kb cDNA product,
shorter than that of BSDL (2.2 kb). The sequence of this transcript corresponds
to the mRNA sequence that codes for the mature human pancreatic BSDL. However, a
deletion of 330 bp is located within the 3'-domain of this cDNA. Therefore data
allowed us to conclude that the 70-kDa BSDL-related protein is a 612 amino acid
length protein and represents a truncated form of BSDL. The deletion of 110 amino
acids occurs in the C-terminal region of the protein, which encompasses 6
tandemly repeated sequences instead of the 16 normally present in the sequence of
BSDL. Because feto-acinar pancreatic protein (FAPP), which is the oncofetal
counterpart of BSDL, is a C-terminally truncated isoform of BSDL, it is suggested
that the 70-kDa BSDL-related protein expressed in MiaPaCa-2 cells could be
representative of the protein moiety of FAPP.
PMID- 10683254
TI - Development of disulfide peptide mapping and determination of disulfide structure
of recombinant human osteoprotegerin chimera produced in Escherichia coli.
AB - Recombinant human osteoprotegerin chimera is a 90-kDa protein containing a human
IgG Fc domain fused to human osteoprotegerin. The molecule is a dimer linked by
two intermolecular disulfide bonds and contains eleven intramolecular disulfide
bonds per monomer. A cysteine-rich region in osteoprotegerin contains nine
disulfide bridges homologous to the cysteine-rich signature structure of the
tumor necrosis factor receptor/nerve growth factor receptor superfamily. In this
report, we have developed peptide mapping procedures suitable to generate
disulfide-containing peptides for disulfide structure assignment of the fusion
molecule. The methods employed included proteolytic digestion using
endoproteinases Glu-C and Lys-C in combination followed by LC-MS analyses.
Disulfide linkages of peptide fragments containing a single disulfide bond were
assigned by sequence analysis via detection of (phenylthiohydantoinyl) cystine
and/or by MS analysis. Disulfide bonds of a large, core fragment containing three
peptide sequences linked by four disulfides were assigned after generation of
smaller disulfide-linked peptides by a secondary thermolysin digestion. Disulfide
structures of peptide fragments containing two disulfide bonds were assigned
using matrix-assisted laser desorption ionization mass spectrometry with
postsource decay. Both the inter- and intramolecular disulfide linkages of the
chimeric dimer were confirmed.
PMID- 10683255
TI - Isolation and characterization of glycophorin from nucleated (chicken)
erythrocytes.
AB - A sialoglycoprotein fraction was isolated from chicken erythrocytes by two
methods based on the phenol extraction or chloroform/2-propanol extraction of
differently prepared erythrocyte membranes. Both preparations gave in SDS-PAGE
two major PAS-stained bands (GP2 and GP3), which migrated as 60- and 33-kDa
species, respectively, compared to reference proteins, or as 44- and 23-kDa
molecules, compared to human glycophorins. Some less abundant slower migrating
PAS-stained components, antigenically related to GP2 and GP3, also were detected.
No evidence for the presence of antigenically distinct glycoproteins of
leukosialin type was obtained. Interconversion in SDS-PAGE, similar carbohydrate
composition, and similar antigenic properties of GP2 and GP3 indicated that they
are a dimer and monomer, respectively, of the same glycoprotein which shows
properties that allow it to be classified as a glycophorin. Lectin binding
studies and methylation analysis of beta-elimination products of chicken
glycophorin preparation showed the presence of O-glycans and N-glycans. The major
O-glycans include sialylated Galbeta1-3GalNAc units and more complex GlcNAc
containing chains. Among the N-glycans, there are complex-type biantennary
structures with a bisecting GlcNAc residue, accompanied by chains with additional
antennas linked to alpha-mannose residues. A characteristic feature of the
chicken glycophorin is a relatively high proportion of N-glycans to O-glycans,
compared to the glycophorin A from human erythrocytes.
PMID- 10683256
TI - Double-base lesions are produced in DNA by free radicals.
AB - Evidence has been accumulating at the oligomer level that free radical-initiated
DNA damage includes lesions in which two adjacent bases are both modified.
Prominent examples are lesions in which a pyrimidine base is degraded to a
formamido remnant and an adjacent guanine base is oxidized. An assay has been
devised to detect double-base lesions based on the fact that the phosphoester
bond 3' to a nuclesoside bearing the formamido lesion is resistant to hydrolysis
by nuclease P1. The residual modified dinucleoside monophosphates obtained from a
nuclease P1 (plus acid phosphatase) digest of DNA can be (32)P-postlabeled using
T4 polynucleotide kinase. Using this assay the formamido single lesion and the
formamido-8-oxoguanine double lesion were detected in calf thymus DNA after X
irradiation in oxygenated aqueous solution. The lesions were measured in the
forms d(P(F)pG) and d(P(F)pG(H)), where P(F) stands for a pyrimidine nucleoside
having the base degraded to a formamido remnant and G(H) stands for 8-oxo
deoxyguanosine. The yields in calf thymus DNA irradiated 60 Gy were 8.6 and 3.2
pmol/microgram DNA, respectively.
PMID- 10683257
TI - P(1),P(4)-Diadenosine 5'-tetraphosphate modulates l-arginine and l-citrulline
uptake by bovine aortic endothelial cells.
AB - We have previously demonstrated that P(1),P(4)-diadenosine 5'-tetraphosphate
(Ap(4)A) interacts with high-affinity and low-affinity binding sites on the
bovine aortic endothelial cell (BAEC) surface. In this report we demonstrate that
Ap(4)A interaction with the lower affinity site modulates l-arginine (l-Arg) and
l-citrulline (l-Cit) uptake by BAEC. Competition uptake studies demonstrate that
l-Arg and l-Cit uptake occurs through a common transporter system that is
sensitive to Ap(4)A. Evidence is also presented that is consistent with Ap(4)A
modulating l-Arg uptake by increasing the affinity of l-Arg for the transporter.
PMID- 10683258
TI - Monovalent cation activation in Escherichia coli inosine 5'-monophosphate
dehydrogenase.
AB - Inosine 5'-monophosphate dehydrogenase (IMPDH) catalyzes the oxidation of inosine
5'-monophosphate (IMP) to xanthosine 5'-monophosphate with the concomitant
reduction of NAD to NADH. Escherichia coli IMPDH is activated by K(+), Rb(+),
NH(+)(4), and Cs(+). K(+) activation is inhibited by Li(+), Na(+), Ca(2+), and
Mg(2+). This inhibition is competitive versus K(+) at high K(+) concentrations,
noncompetitive versus IMP, and competitive versus NAD. Thus monovalent cation
activation is linked to the NAD site. K(+) increases the rate constant for the
pre-steady-state burst of NADH production, possibly by increasing the affinity of
NAD. Three mutant IMPDHs have been identified which increase the value of K(m)
for K(+): Asp13Ala, Asp50Ala, and Glu469Ala. In contrast to wild type, both
Asp13Ala and Glu469Ala are activated by all cations tested. Thus these mutations
eliminate cation selectivity. Both Asp13 and Glu469 appear to interact with the
K(+) binding site identified in Chinese hamster IMPDH. Like wild-type IMPDH, K(+)
activation of Asp50Ala is inhibited by Li(+), Na(+), Ca(2+), and Mg(2+). However,
this inhibition is noncompetitive with respect to K(+) and competitive with
respect to both IMP and NAD. Asp50 interacts with residues that form a rigid wall
in the IMP site; disruption of this wall would be expected to decrease IMP
binding, and the defect could propagate to the proposed K(+) site. Alternatively,
this mutation could uncover a second monovalent cation binding site.
PMID- 10683259
TI - Reactivity of the cysteine residues in the protein splicing active center of the
Mycobacterium tuberculosis RecA intein.
AB - Protein splicing involves the self-catalyzed excision of an intervening
polypeptide segment, an intein, from a precursor protein. The first two steps in
the protein splicing process lead to the formation of ester intermediates through
nucleophilic attacks by the side chains of cysteine, serine, or threonine
residues adjacent to the splice junctions. Since both nucleophilic residues in
the Mycobacterium tuberculosis RecA intein are cysteine, their reactivities could
be compared by sulfhydryl group titration. This was accomplished by using fusion
proteins containing a truncated RecA intein modified by mutation to prevent
protein splicing, in which the cysteines at the splice junctions were the only
sulfhydryl groups. The ability to undergo hydroxylamine-induced cleavage at the
upstream splice junction showed that the modified intein was not impaired in the
ability to form ester intermediates. Sulfhydryl titration with iodoacetamide,
monitored by quantitating the residual thiols after reaction with a maleimide
derivative of biotin, revealed a striking difference in the apparent pK(a) values
of the cysteines at the two splice junctions. The apparent pK(a) of the cysteine
at the upstream splice junction, which initiates the N-S acyl rearrangement
leading to the linear ester intermediate, was approximately 8.2, whereas that of
the cysteine residue at the downstream splice junction, which initiates the
transesterification reaction converting the linear ester to the branched ester
intermediate, was about 5.8. This suggests that the transesterification step is
facilitated by an unusually low pK(a) of the attacking thiol group. Comparison of
the rates of cleavage of the linear ester intermediates derived from the M.
tuberculosis RecA and the Saccharomyces cerevisiae VMA inteins by dithiothreitol
and hydroxylamine revealed that the former reacted relatively more slowly with
dithiothreitol, suggesting that the RecA intein has diverged in the course of
evolution to react preferentially with thiolate anions and thus lacks the basic
groups that may facilitate nucleophilic attack by thiols in other inteins.
PMID- 10683260
TI - Thyroid hormone and dehydroepiandrosterone permit gluconeogenic hormone responses
in hepatocytes.
AB - The importance of the sn-glycerol- 3-phosphate (G-3-P) electron transfer shuttle
in hormonal regulation of gluconeogenesis was examined in hepatocytes from rats
with decreased mitochondrial G-3-P dehydrogenase activity (thyroidectomized) or
increased G-3-P dehydrogenase activity [triiodothyronine (T(3)) or
dehydroepiandrosterone (DHEA) treated]. Rates of glucose formation from 10 mM
lactate, 10 mM pyruvate, or 2.5 mM dihydroxyacetone were somewhat less in
hypothyroid cells than in cells from normal rats but gluconeogenic responses to
calcium addition and to norepinephrine (NE), glucagon (G), or vasopressin (VP)
were similar to the responses observed in cells from normal rats. However, with
2. 5 mM glycerol or 2.5 mM sorbitol, substrates that must be oxidized in the
cytosol before conversion to glucose, basal gluconeogenesis was not appreciably
altered by hypothyroidism but responses to calcium and to the calcium-mobilizing
hormones were abolished. Injecting thyroidectomized rats with T(3) 2 days before
preparing the hepatocytes greatly enhanced gluconeogenesis from glyc erol and
restored the response to Ca(2+) and gluconeogenic hormones. Feeding
dehydroepiandrosterone for 6 days depressed gluconeogenesis from lactate or
pyruvate but substantially increased glucose production from glycerol in
euthyroid cells and restored responses to Ca(2+) in hypothyroid cells
metabolizing glycerol. Euthyroid cells metabolizing glycerol or sorbitol use the
G-3-P and malate/aspartate shuttles to oxidize excess NADH generated in the
cytosol. The transaminase inhibitor aminooxyacetate (AOA) decreased
gluconeogenesis from glycerol 40%, but had little effect on responses to Ca(2+)
and NE. However, in hypothyroid cells, with minimal G-3-P dehydrogenase, AOA
decreased gluconeogenesis from glycerol more than 90%. Thus, the basal rate of
gluconeogenesis from glycerol in the euthyroid cells is only partly dependent on
electron transport from cytosol to mitochondria via the malate/aspartate shuttle
and almost completely dependent in the hypothyroid state, and the hormone
enhancement of the rate in euthyroid cells involves primarily the G-3-P cycle.
These data are consistent with Ca(2+) being mobilized by gluconeogenic hormones
and G-3-P dehydrogenase being activated by Ca(2+) so as to permit it to transfer
reducing equivalents from the cytosol to the mitochondria.
PMID- 10683261
TI - The "SUN" family: UTH1, an ageing gene, is also involved in the regulation of
mitochondria biogenesis in Saccharomyces cerevisiae.
AB - Since it was shown in previous work that NCA3 (one of the four genes of the SUN
family) is involved in mitochondrial protein synthesis regulation, the effect of
the other members of this gene family was tested. UTH1 (but not SUN4 or SIM1) was
also shown to interfere with mitochondria biogenesis. In Deltauth1 cells,
cytochromes aa(3), c, and b were lowered by 25 and 15%, respectively. In the
double-null mutant Deltauth1Deltanca3, only cytochrome aa(3) was lowered by 50%
relative to the wild type. However, the ratio of cellular respiration to
cytochrome oxidase was greatly enhanced in the double-null mutant. Measurements
on whole lysed cells showed that another mitochondrial enzyme, citrate synthase,
was also lowered in Deltauth1 and Deltauth1Deltanca3 whereas hexokinase was not.
Electron micrographs showed no difference in global mitochondria content in
Deltauth1Deltanca3, but mitochondria appeared less dense to electrons compared to
the wild type. Cardiolipin and mtDNA were equivalent in parental and mutant
strains. Measurements on isolated mitochondria showed that the cyt aa(3)/cyt b
ratio was also lowered in Deltauth1Deltanca3, but the control exerted by the
oxidase on the respiratory flux was higher. The activity of other mitochondrial
complexes versus oxidase was equivalent in mutants compared to the wild type.
These results suggest that the protein equipment could be lowered in mitochondria
from strains inactivated for UTH1.
PMID- 10683262
TI - Acan125 binding to the SH3 domain of acanthamoeba myosin-IC.
AB - The domain organization of Acanthamoeba myosin-I, an oligomodular motor protein,
includes a potentially important protein interaction module that is mostly
uncharacterized. The Src homology 3, SH3, domain of myosin-I binds Acan125, a
protein containing at least two consensus ligand binding domains: C-terminal SH3
binding motifs (PXXP) and N-terminal leucine-rich repeats. We report the first
affinities determined for an SH3 domain of any myosin, namely, K(d) = 7 microM
for a 21-residue synthetic peptide based on the PXXP domain sequence and K(d) =
0.15 microM for the PXXP domain included in the C-terminus of Acan125. These
values are consistent with affinities reported for peptides and proteins that
associate with SH3. By deletional analysis we show that only the PXXP domain is
required for Acan125 to interact with the SH3 domain of Acanthamoeba myosin-IC
(AmyoC(SH3)). The synthetic peptide described above at a concentration near the
K(d) for SH3 binding blocked the interaction between native AmyoC and Acan125,
mapping the interaction to the PXXP domain of Acan125 and the SH3 domain of
myosin-I. These results are consistent with prototypical SH3 binding and suggest
that a PXXP module is both necessary and sufficient to interact with an SH3
module of myosin-I.
PMID- 10683263
TI - Further analysis of maize C(4) pyruvate,orthophosphate dikinase phosphorylation
by its bifunctional regulatory protein using selective substitutions of the
regulatory Thr-456 and catalytic His-458 residues.
AB - In C(4) plants such as maize, pyruvate,orthophosphate dikinase (PPDK) catalyzes
the regeneration of the initial carboxylation substrate during C(4)
photosynthesis. The primary catalytic residue, His-458 (maize C(4) PPDK), is
involved in the ultimate transfer of the beta-phosphate from ATP to pyruvate.
C(4) PPDK activity undergoes light-dark regulation in vivo by reversible
phosphorylation of a nearby active-site residue (Thr-456) by a single
bifunctional regulatory protein (RP). Using site-directed mutagenesis of maize
recombinant C(4) dikinase, we made substitutions at the catalytic His residue
(H458N) and at this regulatory target Thr (T456E, T456Y, T456F). Each of these
affinity-purified mutant enzymes was assayed for changes in dikinase activity. As
expected, substituting His-458 with Asn results in a catalytically incompetent
enzyme. Substitutions of the Thr-456 residue with Tyr and Phe reduced activity by
about 94 and 99%, respectively. Insertion of Glu at this position completely
abolished activity, presumably by the introduction of negative charge proximal to
the catalytic His. Furthermore, neither the T456Y nor inactive H458N mutant
enzyme was phosphorylated in vitro by RP. The inability of the former to serve as
a phosphorylation substrate indicates that RP is functionally a member of the
Ser/Thr family of protein kinases rather than a "dual-specificity" Ser-Thr/Tyr
kinase, since our previous work showed that RP effectively phosphorylated Ser
inserted at position 456. The inability of RP to phosphorylate its native target
Thr residue when Asn is substituted for His-458 documents that RP requires the
His-P catalytic intermediate form of PPDK as its protein substrate. For these
latter studies, synthetic phosphopeptide-directed antibodies specific for the
Thr(456)-P form of maize C(4) PPDK were developed and characterized.
PMID- 10683264
TI - Removal of the tryptophan 139 side chain in Escherichia coli D-3-phosphoglycerate
dehydrogenase produces a dimeric enzyme without cooperative effects.
AB - Escherichia coli d-3-phosphoglycerate dehydrogenase (PGDH) is a homotetrameric
enzyme whose activity is allosterically regulated by l-serine, the end-product of
its metabolic pathway. Previous studies have shown that PGDH displays two modes
of cooperative interaction. One is between the l-serine binding sites and the
other is between the l-serine binding sites and the active sites. Tryptophan 139
participates in an intersubunit contact near the active site catalytic residues.
Site-specific mutagenesis of tryptophan 139 to glycine results in the
dissociation of the tetramer to a pair of dimers and in the loss of cooperativity
in serine binding and between serine binding and inhibition. The results suggest
that the magnitude of inhibition of activity at a particular active site is
primarily dependent on serine binding to that subunit but that activity can be
modulated in a cooperative manner by interaction with adjacent subunits. The
disruption of the nucleotide domain interface in PGDH by mutating Trp-139
suggests the potential for a critical role of this interface in the cooperative
allosteric processes in the native tetrameric enzyme.
PMID- 10683265
TI - Substrate preferences of caffeic acid/5-hydroxyferulic acid 3/5-O
methyltransferases in developing stems of alfalfa (Medicago sativa L.).
AB - Caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase (COMT, EC 1.2.1.68)
catalyzes at least two reactions in lignin biosynthesis. Of its two supposed
substrates in the lignin pathway, COMT from most sources methylates 5
hydroxyferulic acid (5HFA) with two to three times higher activity than caffeic
acid (CafA). The ratio of activity for 5HFA compared with CafA increases with the
developmental age of alfalfa (Medicago sativa L.) stem internodes, from
approximately 1:1 in young (third and fourth) internodes to 2:1 in mature
(seventh and eighth) internodes. This observation, together with immunoblot
analysis using antiserum raised against recombinant alfalfa COMT, suggests the
presence of a different form of COMT, having preference for CafA compared with
5HFA, in young internodes. This apparently new O-methyltransferase (COMT II) was
separated from the previously characterized COMT (COMT I) by anion exchange and
hydrophobic interaction chromatography. COMT I, but not COMT II, was found in
mature internodes. COMT II was not recognized by anti-(COMT I) serum.
Furthermore, in addition to substrate preference, COMT II differed from COMT I in
native relative molecular mass, pH optimum, and its very low K(m) for CafA. The
possible physiological role of COMT II is discussed.
PMID- 10683266
TI - Cellular and enzymatic studies of N(omega)-propyl-l-arginine and S-ethyl-N-[4
(trifluoromethyl)phenyl]isothiourea as reversible, slowly dissociating inhibitors
selective for the neuronal nitric oxide synthase isoform.
AB - N(omega)propyl-l-arginine (NPA) and S-ethyl-N-[4
(trifluoromethyl)phenyl]isothiourea (TFMPITU) inhibit selectively the neuronal
nitric oxide (NO) synthase (nNOS) isoform. In the presence of Ca(2+) and
calmodulin (CaM), NPA and TFMPITU produce a time- and concentration-dependent
suppression of nNOS catalyzed NO formation. This suppression of activity occurs
by a first order kinetic process as revealed from linear Kitz-Wilson plots but
does not depend on catalytic turnover since it occurs in the absence of NADPH.
Following full suppression of NO synthetic activity by either NPA or TFMPITU, NO
synthesis can be restored slowly by excess arginine or by dilution, indicating
that the effects of these agents are reversible. This behavior is consistent with
a dissociation of NPA and TFMPITU from nNOS slowed by a conformational transition
produced by Ca(2+) CaM-binding. NPA and TFMPITU bind to nNOS rapidly producing a
heme-substrate interaction as revealed by difference spectrophotometry. At
physiological conditions (100 microM extracellular arginine), NPA and TFMPITU
inhibit Ca(2+)-dependent NO formation by GH(3) pituitary cells with IC(50) values
of 19 and 47 microM, respectively, but require millimolar concentrations to
inhibit NO formation by cytokine-induced RAW 264.7 murine macrophages. The
inhibition of NO formation by these agents in GH(3) cells is rapidly reversible
and not due to suppression of cellular arginine uptake.
PMID- 10683267
TI - Purification and characterization of the human recombinant histidine-tagged
prostaglandin endoperoxide H synthases-1 and -2.
AB - We have used in vitro mutagenesis to introduce a six residue histidine sequence
(His-tag) near the amino terminal end of the human PGHS-1 and -2 and have
expressed these proteins using the baculovirus system. The His-tags are located
one and two amino acids beyond the signal peptide cleavage sites of PGHS-1 and
PGHS-2, respectively, positions that do not affect their activities or
sensitivities to nonsteroidal anti-inflammatory drugs. When expressed in sf-21
cells, the His-tagged enzymes have K(m) values for arachidonate, and IC(50)
values for inhibition by nonsteroidal anti-inflammatory drugs that are similar to
values reported for the nontagged enzymes. The His-tags allowed for purification
of the PGHSs by a simplified protocol involving nickel-affinity and anion
exchange FPLC chromatography. The specific activities and recoveries for the
purified enzymes were as good or better than those reported previously for
purification of the non-tagged PGHS. These baculovirus constructs should provide
a convenient source for pharmacologic and biophysical studies that require large
scale preparation of human PGHSs.
PMID- 10683268
TI - Modulation of glutathione synthetic enzymes by acidic fibroblast growth factor.
AB - Increasing evidence suggests that glutathione (GSH) synthesis is a regulated
process. Documented increases in gamma-glutamylcysteine synthetase (GCS) occur in
response to oxidants, in tumors, on plating cells at a low cell density, and with
nerve growth factor stimulation, suggesting that GSH synthesis may be related to
the cell growth and transformation. Previously, extracellular acidic fibroblast
growth factor (FGF-1) has been demonstrated to cause transformation and
aggressive cell growth in murine embryonic fibroblasts. In the present
investigation, we sought to determine whether FGF-1, with its growth inducing
properties, resulted in the modulation of GSH biosynthetic enzymes, GCS and GSH
synthetase. Murine fibroblasts transduced with (hst/KS)FGF-1, a chimeric human
FGF-1 gene containing a signal peptide sequence for secretion, displayed elevated
gene expression of both heavy and light subunits of GCS. Activity of GSH
synthetase was also elevated in these cells compared with control cells.
Nonetheless, GSH was decreased in the FGF-1-transduced cells along with high
energy phosphates, adenine nucleotides, NADH, and the redox poise. However, GSSG
was not elevated in these cells. Fibroblasts stably expressing human
immunodeficiency virus type 1 Tat, which induces intrinsic FGF-1 secretion,
resulted in similar changes in GCS, GS, and GSH. The results suggest that
although increases in the enzymes of GSH synthesis are a common response to
growth factors, an increase in GSH content per se is not required for altered
cell growth.
PMID- 10683269
TI - Effects of spinal cord X-irradiation on the recovery of paraplegic rats.
AB - Axonal regrowth is limited in the adult CNS, especially in the spinal cord, one
of the major sites of traumatic lesions. Pathophysiological changes occurring
after spinal cord injury include complex acute, subacute, and late processes. In
this study, we assessed whether X-irradiation interferes with the acute/subacute
phases, thereby improving the functional recovery of paraplegic animals. Two days
after acute compression of adult rat spinal cords, various doses (0, 2, 5, 10, 20
Gy) of X-rays were administered as one single dose to the compression site. The
animals were functionally evaluated over the course of 1 month after injury,
using the Tarlov scale and the Rivlin and Tator scale. We also designed a
"physiological" scale, including an assessment of urinary function and infection,
appropriate for the evaluation of spinal-cord-lesioned animals. Behavioral
analysis suggested that the high doses, 20 Gy and, to a lesser extent, 5 and 10
Gy, were toxic, as shown by morbidity rate and "physiological" score. The 2-Gy
group showed better motor performances than the lesioned nonirradiated (LNI)
animals and the 5- and 20-Gy groups. Motor performance in the 5-, 10-, and 20-Gy
groups was poorer than that seen in the LNI group. Gliosis was reduced in the 2
Gy group compared to LNI animals, and there was high levels of gliosis in the
highly (>/=5 Gy) irradiated animals. There was a 23% less lesion-induced
syringomyelia in the 2-Gy group than in the other groups (LNI and 5-20 Gy). Thus,
low doses of X-rays may interfere with the formation of syringomyelia and glial
scar, thereby facilitating the recovery of paraplegic animals. These findings
suggest that low-dose irradiation of the lesion site, in association with other
therapies, is a potentially promising treatment for improving recovery after
spinal cord injury.
PMID- 10683270
TI - Light and confocal microscopic studies of evolutionary changes in neurofilament
proteins following cortical impact injury in the rat.
AB - Previous studies have shown that traumatic brain injury (TBI) produces
progressive degradation of cytoskeletal proteins including neurofilaments (e.g.,
neurofilament 68 [NF68] and neurofilament 200 [NF200]) within the first 24 h
after injury. Thus, we employed immunofluorescence (light and confocal
microscopy) to study the histopathological correlates of progressive
neurofilament protein loss observed at 15 min, 3 h, and 24 h following unilateral
cortical injury in rats. TBI produced significant alterations in NF68 and NF200
immunolabeling in dendrites and cell bodies at contusion sites ipsilateral to
injury, as well as in the noncontused contralateral cortex. Changes in
immunolabeling were associated with, but not exclusively restricted to, regions
previously shown to contain dark shrunken neurons labeled by hematoxylin and
eosin staining, a morphopathological response to injury suggesting impending cell
death. Immunofluorescence microscopic studies of neurofilament proteins in the
ipsilateral cerebral cortex detected prominent fragmentation of apical dendrites
of pyramidal neurons in layers 3-5 and loss of fine dendritic arborization within
layer 1. While modest changes were observed 15 min following injury, more
pronounced loss of dendritic neurofilament immunofluorescence was detected 3 and
24 h following injury. Confocal microscopy also revealed progressive alterations
in NF68 immunoreactivity in dendrites following TBI. While some evidence of
structural alterations was observed 15 min following TBI, dendritic breaks were
readily detected in confocal micrographs from 3 to 24 h following injury.
However, disturbances in axonal NF68 by immunofluorescence microscopy in the
corpus callosum were not detected until 24 h after injury. These studies
confirmed that derangements in dendritic neurofilament cytoskeletal proteins are
not exclusively restricted to sites of impact contusion. Moreover, changes in
dendritic cytoskeletal proteins are progressive and not fully expressed within
the first 15 min following impact injury. These progressive dendritic disruptions
are characterized by disturbances in the morphology of neurofilament proteins,
resulting in fragmentation and focal loss of NF68 immunofluorescence within
apical dendrites. In contrast, alterations in axonal cytoskeletal proteins are
more restricted and delayed with no pronounced changes until 24 h after injury.
PMID- 10683271
TI - Tanycytes transplanted into the adult rat spinal cord support the regeneration of
lesioned axons.
AB - During past years a number of therapeutic strategies have been developed in order
to stimulate axonal regeneration after traumatic injuries of the spinal cord.
Recently, encouraging data have been obtained by grafting specific glial cells
such as Schwann cells or olfactory ensheathing glial cells, known to support the
regeneration of peripheral or central axons, respectively. In a recent series of
studies, we have shown that tanycytes, a particular glial cell type present in
the mediobasal hypothalamus, were able to support the regeneration of a variety
of axons innervating this region. The aim of the present study was to determine
whether tanycytes could also support the regeneration of lesioned spinal axons.
Cultured hypothalamic tanycytes and cortical astrocytes were prelabeled with Fast
blue (FB) and grafted into the thoracic spinal cord of adult rats. Three weeks
after the transplantation, the animals were fixed and spinal cord sections
treated for multiple fluorescence detection of the FB-labeled transplanted cells
on the one hand and of various glial and neuronal markers on the other hand. We
show here that in all the spinal cords examined, transplanted tanycytes or
astrocytes formed large spherical clusters of about 0.5 mm in diameter, located
in the mediolateral spinal cord layer. The immunodetection of glial markers
showed that transplanted astrocytes exhibited intense immunostaining for both
glial fibrillary acidic protein (GFAP) and vimentin (VIM), whereas transplanted
tanycytes were intensely immunostained for VIM, but GFAP negative. The
immunodetection of axonal markers showed that contrasting with astrocyte
transplants, tanycyte transplants were invaded by numerous axonal fibers. These
data indicate that tanycyte transplants may represent a useful therapeutic tool
for the reparation of the lesioned spinal axons.
PMID- 10683272
TI - Upregulation of BDNF mRNA and trkB mRNA in the nigrostriatal system and in the
lesion site following unilateral transection of the medial forebrain bundle.
AB - We have performed unilateral transection of the medial forebrain bundle (MFB) and
studied BDNF mRNA and trkB mRNA levels at different postlesion times in the
nigrostriatal system by means of in situ hybridization. BDNF mRNA levels were
transiently induced in the substantia nigra pars compacta at 1 day postaxotomy.
The disposition of BDNF mRNA expressing cells at this postlesion time in
substantia nigra mimicked that of the dopaminergic neurons expressing the mRNA
for the dopamine transporter. TrkB mRNA levels remained unaltered in the ventral
mesencephalon at the different postlesion times examined-1 to 14 days. In
contrast, trkB mRNA levels were significantly induced in the striatum at the
longer postlesion time examined-14 days-when all neurodegenerative events are
completed. It is becoming apparent that nigral BDNF mRNA levels are anterogradely
transported to its target tissue in striatum. However, following axotomy, the
lesion site represents a second potential target for BDNF action. Consequently,
we also analyzed the pattern of mRNA expression for BDNF and trkB at the lesion
site where dopaminergic axons are disconnected. There, we found notable
inductions of both BDNF mRNA and trkB mRNA levels at 4 days postaxotomy. BDNF
mRNA expressing cells were confined at the site of axotomy, which coincided
precisely to that showing induction of trkB mRNA. Altogether, our results
anticipate promising trophic roles of BNDF in the injured nigrostriatal system.
PMID- 10683273
TI - Robust regeneration of CNS axons through a track depleted of CNS glia.
AB - Transected CNS axons do not regenerate spontaneously but may do so if given an
appropriate environment through which to grow. Since molecules associated with
CNS macroglia are thought to be inhibitory to axon regeneration, we have tested
the hypothesis that removing these cell types from an area of brain will leave an
environment more permissive for axon regeneration. Adult rats received unilateral
knife cuts of the nigrostriatal tract and ethidium bromide (EB) was used to
create a lesion devoid of astrocytes, oligodendrocytes, intact myelin sheaths,
and NG2 immunoreactive cells from the site of the knife cut to the ipsilateral
striatum (a distance of 6 mm). The regenerative response and the EB lesion
environment was examined with immunostaining and electron microscopy at different
timepoints following surgery. We report that large numbers of dopaminergic nigral
axons regenerated for over 4 mm through EB lesions. At 4 days postlesion
dopaminergic sprouting was maximal and the axon growth front had reached the
striatum, but there was no additional growth into the striatum after 7 days.
Regenerating axons did not leave the EB lesion to form terminals in the striatum,
there was no recovery of function, and the end of axon growth correlated with
increasing glial immunoreactivity around the EB lesion. We conclude that the
removal of CNS glia promotes robust axon regeneration but that this becomes
limited by the reappearance of nonpermissive CNS glia. These results suggest,
first, that control of the glial reaction is likely to be an important feature in
brain repair and, second, that reports of axon regeneration must be interpreted
with caution since extensive regeneration can occur simply as a result of a major
glia-depleting lesion, rather than as the result of some other specific
intervention.
PMID- 10683274
TI - Establishment and properties of a growth factor-dependent, perpetual neural stem
cell line from the human CNS.
AB - The ready availability of unlimited quantities of neural stem cells derived from
the human brain holds great interest for basic and applied neuroscience,
including therapeutic cell replacement and gene transfer following
transplantation. We report here the combination of epigenetic and genetic
procedures for perpetuating human neural stem cell lines. Thus we tested various
culture conditions and genes for those that optimally allow for the continuous,
rapid expansion and passaging of human neural stem cells. Among them, v-myc (the
p110 gag-myc fusion protein derived from the avian retroviral genome) seems to be
the most effective gene; we have also identified a strict requirement for the
presence of mitogens (FGF-2 and EGF) in the growth medium, in effect constituting
a conditional perpetuality or immortalization. A monoclonal, nestin-positive,
human neural stem cell line (HNSC.100) perpetuated in this way divides every 40 h
and stops dividing upon mitogen removal, undergoing spontaneous morphological
differentiation and upregulating markers of the three fundamental lineages in the
CNS (neurons, astrocytes, and oligodendrocytes). HNSC.100 cells therefore retain
basic features of epigenetically expanded human neural stem cells. Clonal
analysis confirmed the stability, multipotency, and self-renewability of the cell
line. Finally, HNSC.100 can be transfected and transduced using a variety of
procedures and genes encoding proteins for marking purposes and of therapeutic
interest (e.g., human tyrosine hydroxylase I).
PMID- 10683275
TI - Experimental gliosarcoma induces chemokine receptor expression in rat brain.
AB - Macrophage/microglial infiltration is a characteristic feature of brain tumors.
The functional role(s) of these cells is complex and could include both trophic
and suppressive effects on tumors. Information has recently emerged about the
molecular signals that regulate the accumulation and function of monocytes in
pathological disorders. Recent data indicate that the chemokine, monocyte
chemoattractant protein-1 (MCP-1), a potent monocyte activating and chemotactic
factor, is a primary regulator of the macrophage response in brain tumors. We
hypothesized that if MCP-1 regulates macrophage/microglial infiltration, then
expression of the specific MCP-1 receptor, CCR2, will be induced in peritumoral
tissue and/or within brain tumors. Identification of a specific receptor that is
preferentially expressed in brain tumors could be important both in terms of
tumor biology and as a potential therapeutic target. We used an established
experimental gliosarcoma model, induced by intracranial transplantation of
cultured 9L cells into adult rat brain, to test this hypothesis. RT-PCR analysis
showed high levels of both MCP-1 and CCR2 mRNA and Western blot analysis
demonstrated increased CCR2 protein in tumor extracts. Immunocytochemistry showed
CCR2 immunoreactive microglia in peritumoral tissue and, unexpectedly, that
intrinsic tumor cells, rather than monocytes, were the predominant source of
CCR2. These results demonstrate that CCR2 expression is markedly upregulated in
this brain tumor model.
PMID- 10683276
TI - Engagement of the scavenger receptor is not responsible for beta-amyloid
stimulation of monocytes to a neurocytopathic state.
AB - Experiments were performed to determine if scavenger receptors (SRs) play a role
in amyloid beta (Abeta) stimulation of peripheral blood monocyte (PBM)
neurotoxicity. Results indicate that Abeta does not block binding of the SR
ligand DiI-acetylated low density lipoprotein to PBM, nor does another SR ligand,
fucoidin, inhibit Abeta-PBM binding. Moreover, neither of three SR ligands alone
stimulates neurotoxicity in PBM, nor antagonizes the ability of Abeta to activate
PBM to a neurocytopathic state. Such findings suggest that Abeta's action is not
dependent upon engagement of the SR ligand binding domain and raise doubts about
the role of SR in Abeta neurotoxicity.
PMID- 10683277
TI - Traumatic brain injury leads to increased expression of peripheral-type
benzodiazepine receptors, neuronal death, and activation of astrocytes and
microglia in rat thalamus.
AB - In mammalian CNS, the peripheral-type benzodiazepine receptor (PTBR) is localized
on the outer mitochondrial membrane within the astrocytes and microglia. PTBR
transports cholesterol to the site of neurosteroid biosynthesis. Several
neurodegenerative disorders were reported to be associated with increased
densities of PTBR. In the present study, we evaluated the changes in the PTBR
density and gene expression in the brains of rats as a function of time (6 h to
14 days) after traumatic brain injury (TBI). Sham-operated rats served as
control. Between 3 and 14 days after TBI, there was a significant increased in
the binding of PTBR antagonist [(3)H]PK11195 (by 106 to 185%, P < 0.01, as
assessed by quantitative autoradiography and in vitro filtration binding) and
PTBR mRNA expression (by 2- to 3. 4-fold, P < 0.01, as assessed by RT-PCR) in the
ipsilateral thalamus. At 14 days after the injury, the neuronal number decreased
significantly (by 85 to 90%, P < 0.01) in the ipsilateral thalamus. At the same
time point, the ipsilateral thalamus also showed increased numbers of the glial
fibrillary acidic protein positive cells (astrocytes, by approximately 3.5-fold)
and the ED-1 positive cells (microglia/macrophages, by approximately 36-fold),
the two cell types known to be associated with PTBR. Increased PTBR expression
following TBI seems to be associated with microglia/macrophages than astrocytes
as PTBR density at different periods after TBI correlated better with the number
of ED-1 positive cells (r(2) = 0.95) than the GFAP positive cells (r(2) = 0.56).
TBI-induced increased PTBR expression is possibly an adaptive response to
cellular injury and may play a role in the pathophysiology of TBI.
PMID- 10683278
TI - Neuronal subclass-selective loss of pyruvate dehydrogenase immunoreactivity
following canine cardiac arrest and resuscitation.
AB - Chronic impairment of aerobic energy metabolism accompanies global cerebral
ischemia and reperfusion and likely contributes to delayed neuronal cell death.
Reperfusion-dependent inhibition of pyruvate dehydrogenase complex (PDHC) enzyme
activity has been described and proposed to be at least partially responsible for
this metabolic abnormality. This study tested the hypothesis that global cerebral
ischemia and reperfusion results in the loss of pyruvate dehydrogenase
immunoreactivity and that such loss is associated with selective neuronal
vulnerability to transient ischemia. Following 10 min canine cardiac arrest,
resuscitation, and 2 or 24 h of restoration of spontaneous circulation, brains
were either perfusion fixed for immunohistochemical analyses or biopsy samples
were removed for Western immunoblot analyses of PDHC immunoreactivity. A
significant decrease in immunoreactivity was observed in frontal cortex
homogenates from both 2 and 24 h reperfused animals compared to samples from
nonischemic control animals. These results were supported by confocal microscopic
immunohistochemical determinations of pyruvate dehydrogenase immunoreactivity in
the neuronal cell bodies located within different layers of the frontal cortex.
Loss of immunoreactivity was greatest for pyramidal neurons located in layer V
compared to neurons in layers IIIc/IV, which correlates with a greater
vulnerability of layer V neurons to delayed death caused by transient global
cerebral ischemia.
PMID- 10683279
TI - Complement component C1q modulates the phagocytosis of Abeta by microglia.
AB - Recent studies showing that microglia internalize the amyloid beta-peptide
(Abeta) suggest that these cells have the potential for clearing Abeta deposits
in Alzheimer's disease, and mechanisms that regulate the removal of Abeta may
therefore be of clinical interest. Previous studies from this laboratory showing
that C1q enhances phagocytosis of cellular targets by rat microglia prompted the
current investigations characterizing the effects of C1q on microglial
phagocytosis of Abeta. Microglia were shown to phagocytose Abeta1-42, in
agreement with observations of other investigators. Uptake of Abeta1-42 was
observed for concentrations of 5-50 microM, and phagocytosis of peptides
containing (14)C or fluorescein (FM) labels was not affected by the interaction
of microglia with C1q-coated surfaces. However, inclusion of C1q (125 nM-1.4
microM) in solutions of 50 microM Abeta1-42 inhibited the uptake of (14)C-Abeta1
42 and FM-Abeta1-42, suggesting that C1q blocks the interaction of Abeta with
microglia. Uptake of Abeta was partially blocked by the scavenger receptor
ligands polyinosinic acid and maleylated BSA. Inhibition of Abeta uptake by C1q
may contribute to the accumulation of fibrillar, C1q-containing plaques that
occurs in parallel with disease progression. These data suggest that mechanisms
which interfere with the binding of C1q to Abeta may be of therapeutic value both
through inhibition of the inflammatory events resulting from complement
activation and via altered access of Abeta sites necessary for ingestion by
microglia.
PMID- 10683280
TI - Genetic dissection of the signals that induce synaptic reorganization.
AB - Synaptic reorganization of mossy fibers following kainic acid (KA) administration
has been reported to contribute to the formation of recurrent excitatory
circuits, resulting in an epileptogenic state. It is unclear, however, whether KA
induced mossy fiber sprouting results from neuronal cell loss or the seizure
activity that KA induces. We have recently demonstrated that certain strains of
mice are resistant to excitotoxic cell death, yet exhibit seizure activity
similar to what has been observed in rodents susceptible to KA. The present study
takes advantage of these strain differences to explore the roles of seizure
activity vs cell loss in triggering mossy fiber sprouting. In order to understand
the relationships between gene induction, cell death, and the sprouting response,
we assessed the regulation of two molecules associated with the sprouting
response, c-fos and GAP-43, in mice resistant (C57BL/6) and susceptible (FVB/N)
to KA-induced cell death. Following administration of KA, increases in c-fos
immunoreactivity were observed in both strains, although prolonged induction of c
fos was present only in the hippocampal neurons of FVB/N mice. Mossy fiber
sprouting following KA administration was also only observed in FVB/N mice, while
induction of GAP-43, a marker associated with mossy fiber sprouting, was not
observed in either strain. These results indicate that: (i) KA-induced seizure
activity alone is insufficient to induce mossy fiber sprouting; (ii) mossy fiber
sprouting may be due to the loss of hilar neurons following kainate
administration; and (iii) induction of GAP-43 is not a necessary component of the
sprouting response that occurs following KA in mice.
PMID- 10683281
TI - Internalization of intracerebrally administered porcine galanin (1-29) by a
discrete nerve cell population in the hippocampus of the rat.
AB - In spite of numerous studies utilizing intraventricular administration of porcine
galanin (1-29), little is known about the spread and cellular distribution of
exogenous galanin following intraventricular administration. In this study a
discrete nerve cell body population with their dendrites became strongly galanin
immunoreactive (IR) in the dorsal hippocampus following intraventricular porcine
galanin (1.5 nmol/rat). Time course experiments showed that after time intervals
of 10 and 20 min, but not at 60 min, scattered small- to medium-sized galanin-IR
nerve cell bodies and their dendrites were present in all layers of the dorsal
and ventral hippocampus. In double-immunolabeling experiments most of these nerve
cells were identified as putative GABA interneurons costoring NPY-IR or
somatostatin-IR in some cases. Twenty minutes after intraventricular injection of
artificial cerebrospinal fluid (aCSF), only endogenous punctate and coarse
galanin-IR terminals were found, but no galanin-IR cell bodies. Intrahippocampal
injection of fluorophore-labeled galanin resulted in the appearance of
fluorescent nerve cell bodies with the same morphology and localization as in the
above experiments. Coadministration of the putative galanin antagonist M35 (0.5
nmol) and galanin (1.5 nmol) resulted in a reduced number of galanin-IR nerve
cell bodies in the hippocampus of half of the rats. These findings support the
existence of a population of putative hippocampal GABA interneurons with the
ability to internalize and concentrate galanin and/or its fragments present in
the extracellular fluid, possibly mediated by galanin receptors.
PMID- 10683282
TI - Prenatal methotrexate exposure decreases seizure susceptibility in young rats of
two strains.
AB - Effects of prenatal exposure to methotrexate (MTX) administered in Sprague-Dawley
(one 5 mg/kg dose of MTX on gestational day 15; E15) or Wistar (one 5 mg/kg dose
of MTX on E14 or E15 or two such doses on E15) pregnant rat dams were studied in
developing offspring. Young Sprague-Dawley rats were subjected to rapid kindling
on postnatal days (PN) 15 and 16, and to flurothyl seizures on PN 15 and PN 30.
Offspring of the Wistar strain were tested in flurothyl on PN 30. In Sprague
Dawley rats, prenatal exposure to MTX decreased susceptibility to kindling
induced seizures on PN 15 and to flurothyl-induced clonic seizures on PN 30. In
Wistar rats, a single dose of MTX on E15 was ineffective, but two doses
significantly decreased susceptibility to flurothyl-induced seizures.
Additionally, due to a shorter duration of pregnancy in Wistar rats, exposure to
a single dose of MTX on E14 also decreased susceptibility to flurothyl seizures.
MTX, as folic acid antagonist, interferes with DNA synthesis. However, unlike
other treatments that suppress DNA synthesis (such as methylazoxymethanol
exposure or X-ray radiation), MTX exposure results in anticonvulsant effects in
surviving offspring. The data suggest that not all prenatal impairments of DNA
have proconvulsant features postnatally.
PMID- 10683283
TI - Brain RNA polymerase and nucleolar structure in perinatal asphyxia of the rat.
AB - Ribosomes are integral constitutens of the protein synthesis machinery.
Polymerase I (POL I) is located in the nucleolus and transcribes the large
ribosomal genes. POL I activity is decreased in ischemia but nothing is known so
far on POL I in perinatal asphyxia. We investigated the involvement of POL I in a
well-documented model of graded systemic asphyxia at the level of activity, mRNA,
protein, and morphology. Caeserean section was performed at the 21st day of
gestation. Rat pups still in the uterus horns were immerged in a water bath for
asphyctic periods from 5-20 min. Brain was taken for measurement of pH, nuclear
POL I activity, and mRNA steady state, and protein levels of RPA40, an essential
subunit of POL I and III. Silver staining and transmission electron microscopy
with morphometry when appropriate were used to examine the nucleolus. Brain pH
and nuclear POL I activity decreased with the length of the asphyctic period
while POL-I mRNA and protein levels were unchanged. Accompanying the decrease in
brain pH we found significant changes of nucleolar structure in the course of
perinatal asphyxia at the light and electron microscopic level. As early as ten
min following the asphyctic insult, morphological disintegration of the nucleolus
was observed. The changes became more dramatic with longer duration of perinatal
asphyxia. We conclude that severe acidosis may be responsible for decreased POL
activity and for disintegration of nucleoli in neurons. This condition may lower
the ribosome content in neonatal neurons and impair protein synthesis.
PMID- 10683284
TI - Sciatic nerve transection in the adult rat: abnormal EMG patterns during
locomotion by aberrant innervation of hindleg muscles.
AB - The effects of lesions in the sciatic nerve were studied in adult rats. In the
left hindleg, a segment 12 mm long was resected from the proximal part of the
nerve, before the bifurcation into the peroneal and tibial nerves. This segment
in a reversed orientation was used as a nerve graft. EMG patterns in the tibialis
anterior and the gastrocnemius muscles at both sides were recorded during
locomotion in six rats after recovery periods varying from 15 to 21 weeks. The
specificity of axonal outgrowth was studied in nine rats by retrogradely labeling
the motoneurons with unconjugated Cholera Toxin subunit B (CTB) after injections
into the gastrocnemius, the soleus, and the tibialis anterior muscles at both
sides. EMG patterns at the operated side were irregular and we often observed
coactivation of the gastrocnemius and tibialis anterior muscle. Moreover, burst
activity was badly adjusted to the phases of the stepcycle. Retrogradely labeling
indicated that the pools of motoneurons innervating the respective muscles at the
left side had increased in volume. Neuronal diameters were slightly decreased but
a considerable decrease was observed in dendritic branching and dendrite bundles
in the pools of the SOL and in the GC were absent. No consistent trends in
neuronal numbers at the affected side in comparison to the right side were
detected. We conclude that axons, sprouting from the proximal stump of the
sciatic nerve, innervate the muscles aselectively and that the motoneurons of
origin maintain their original activation pattern.
PMID- 10683285
TI - Safety and tolerability assessment of intrastriatal neural allografts in five
patients with Huntington's disease.
AB - This study describes issues related to the safety and tolerability of fetal
striatal neural allografts as assessed in five patients with Huntington's
disease. Huntington's disease (HD) is characterized by motor, cognitive, and
behavioral disturbances. The latter include psychological disturbances and, as a
consequence, we took particular care to analyze behavioral changes, in addition
to the usual "safety" follow-up. We conducted multidisciplinary follow-up at
least 2 years before and 1 year after grafting. Psychological care extended to
close relatives. The grafting procedure itself was altogether safe and
uneventful, and there were no apparent clinical deleterious effects for 1 year.
The immunosuppressive treatment, however, was complicated by various problems
(irregular compliance, errors of handling, side effects). Direct psychological
consequences of the transplantation procedure were rare and not worrisome,
although mood alteration requiring treatment was observed in one patient.
Indirectly, however, the procedure required patients and relatives to accept
constraints that tended to complicate familial situations already marred by
aggressivity and depression. All patients and close relatives expressed major
expectations, in spite of our strong and repeated cautioning. It is clearly
important to be aware of these particular conditions since they may eventually
translate into psychological difficulties in coping with the long-term clinical
outcome of the procedure, if not beneficial. Despite an overall good tolerance,
therefore, this follow-up calls for caution regarding the involvement of HD
patients in experimental surgical protocols.
PMID- 10683286
TI - Reversible physiological alterations in sympathetic neurons deprived of NGF but
protected from apoptosis by caspase inhibition or Bax deletion.
AB - Cell death in nervous system development and in many neurodegenerative diseases
appears to be apoptotic or programmed. Withdrawal of nerve growth factor (NGF)
from cultures of superior cervical ganglia neurons (SCG) is an excellent model of
programmed cell death (PCD), producing apoptosis within 24-48 h. This death can
be prevented by treatment with caspase inhibitors or deletion of the proapoptotic
Bax gene. Since inhibition of apoptosis is an attractive strategy for the therapy
of many neurological diseases and little is known about the function of neurons
when apoptosis has been aborted, we examined the electrophysiological properties
of NGF-deprived SCG neurons from rats and mice, saved by the caspase inhibitor
boc-aspartyl(OMe)fluoromethyl ketone (BAF) or by Bax deletion. Compared to NGF
maintained controls, the resting membrane potentials of BAF-saved neurons were
depolarized by 9 mV and the action potentials were prolonged by over 50%.
Nicotinic cholinergic current density was depressed by about 50%.
Electrophysiological parameters returned to normal within 4 days after NGF
restoration. Neurons from Bax-deficient mice were altered differently by NGF
withdrawal. There were no detectable changes in resting or action potentials.
However, nicotinic current density was reduced just as in BAF-saved rat neurons.
There were no observable changes in the processes of individual neurons after 6
days of NGF deprivation in the presence of BAF. Our results indicate that neurons
are physiologically altered during pharmacological inhibition of PCD, but fully
recover after trophic support is returned.
PMID- 10683287
TI - Effect of acute L-Dopa pretreatment on apomorphine-induced rotational behavior in
a rat model of Parkinson's disease.
AB - Currently, reduction of apomorphine-induced rotational behavior in the 6
hydroxydopamine (6-OHDA) lesioned rat is the most utilized drug-induced paradigm
for assessing functional efficacy in a rat model of Parkinson's disease (PD). Any
clinically predictive animal model of PD should include a positive response to l
dopa, the standard pharmacotherapy for PD. However, the acute interaction between
L-dopa and apomorphine has never been studied to determine if L-dopa pretreatment
could reduce apomorphine-induced rotational behavior in a 6-OHDA lesioned rat.
The present study was designed to explore whether, indeed, pretreatment with
subrotational doses of L-dopa could inhibit apomorphine-induced rotations. The
data indicate that L-dopa significantly reduced apomorphine-induced rotational
behavior only at one dose (5.0 mg/kg) for 12 min. Based on these and other data,
it is concluded that although the apomorphine-induced rotational paradigm may
continue to be utilized as one additional indicator of efficacy in the 6-OHDA rat
model of PD, it is not in itself a completely valid functional assay.
PMID- 10683288
TI - Chronic, selective forebrain responses to excitotoxic dorsal horn injury.
AB - Intraspinal injection of the AMPA/metabotropic receptor agonist quisqualic acid
(QUIS) results in excitotoxic injury which develops pathological characteristics
similar to those associated with ischemic and traumatic spinal cord injury (SCI)
(R. P. Yezierski et al., 1998, Pain 75: 141-155; R. P. Yezierski et al., 1993, J.
Neurotrauma 10: 445-456). Since spinal injury can lead to partial or complete
deafferentation of ascending supraspinal structures, it is likely that secondary
to the disruption of spinal pathways these regions could undergo significant
reorganization. Recently, T. J. Morrow et al. (Pain 75: 355-365) showed that
autoradiographic estimates of regional cerebral blood flow (rCBF) can be used to
simultaneously identify alterations in the activation of multiple forebrain
structures responsive to noxious formalin stimulation. Accordingly, we examined
whether excitotoxic SCI produced alterations in the activation of supraspinal
structures using rCBF as a marker of neuronal activity. Twenty-four to 41 days
after unilateral injection of QUIS into the T12 to L3 spinal segments, we found
significant increases in the activation of 7 of 22 supraspinal structures
examined. As compared to controls, unstimulated SCI rats exhibited a significant
bilateral increase in rCBF within the arcuate nucleus (ARC), the hindlimb region
of S1 cortex (HL), parietal cortex (PAR), and the thalamic posterior (PO),
ventral lateral (VL), ventral posterior lateral (VPL), and ventral posterior
medial (VPM) nuclei. All structures showing significantly altered rCBF are
associated with the processing of somatosensory information. These changes
constitute remote responses to injury and suggest that widespread functional
changes occur within cortical and subcortical regions following injury to the
spinal cord.
PMID- 10683289
TI - Is Fos protein expressed by dying striatal neurons after immature hypoxic
ischemic brain injury?
AB - The transient induction of mRNA for the immediate-early gene c-fos has been
reported following hypoxic-ischemic brain injury in the immature brain. However,
no studies have examined the temporal expression of Fos protein, which is the
functionally relevant product of c-fos gene expression. Increased expression of
Fos protein has been linked to cell death. We therefore examined whether Fos
protein is expressed by dying neurons after immature hypoxic-ischemic brain
injury. A well characterized immature rat model of hypoxic-ischemic injury at
postnatal day (PN) 7 was used. Three hypoxic-ischemic and three normoxic control
pups were studied per time point (i.e., 0, 2, 12, 24, 48, and 72 h
posttreatment). Expression of Fos within striatal and other neurons was detected
immunocytochemically. Fos protein was expressed within dying striatal neurons at
0-12 h after hypoxia-ischemia. However, detection was only seen in 2 of 17
hypoxic-ischemic pups. These 2 pups had >/=80% of their striatal neurons dying
within their right, hypoxic-ischemic-exposed hemisphere. Fos protein expression
after severe injury may, therefore, be a response to extraordinary or extreme
stress. The absence of Fos protein expression in the majority of hypoxic-ischemic
pups, which all exhibited striatal neuronal death, suggests that Fos expression
is not necessary for cell death to occur. Therapies directed against Fos protein
expression may therefore have limited usefulness in immature hypoxic-ischemic
brain injury.
PMID- 10683290
TI - Evidence that Cereport's ability to increase permeability of rat gliomas is
dependent upon extent of tumor growth: implications for treating newly emerging
tumor colonies.
AB - Cereport (RMP-7) enhances delivery of chemotherapeutics into brain tumors by
increasing the permeability of the glioma vasculature (i.e. , the blood-brain
tumor barrier; BBTB). Its effect on brain tumors has consistently been more
robust than that on normal brain. The present experiments tested the hypothesis
that the ability of Cereport to increase the permeability of infiltrating glioma
colonies increases as the glioma colonies develop, in situ. In an initial
preliminary experiment, the significant and selective effects of Cereport in
tumor tissue and brain surrounding tumor were verified using [(14)C]carboplatin
as a marker, 8 days after implantation of 50,000 RG2 cells. A second preliminary
experiment established that the number of tumor cells initially seeded influences
the growth rate of the tumor mass. Tumors seeded with 50,000 cells were larger
than those seeded with 25,000 cells 3, 5, and 8 days after implantation. Next,
the hypothesis that the extent of tumor growth increases Cereport's effects on
the BBTB was tested by measuring the concentration of radiolabeled carboplatin in
the tumor when 50,000 cells were implanted 3, 8, or 13 days prior to the
experiment. While a reliable, approximately twofold increase in carboplatin
concentration was seen in the 8- and 13-day-old tumors, no significant effect of
Cereport was observed in the tumors that developed only 3 days, in situ. Finally,
another test of the hypothesis was made by comparing Cereport's effects on 8-day
old tumors initially seeded with either 50,000 or 25,000 cells (the latter
producing a smaller, more slowly developing, tumor mass). Again, significantly
higher carboplatin concentrations were seen with Cereport in the 50,000 cell
tumors (greater than two-fold increase), compared to the smaller, more slowly
developing, 25,000 cell tumors (<30% increase). The tumor and its vasculature
were characterized in additional rats implanted with RG2 cells using CD-31,
laminin, and bradykinin B(2) receptor immunocytochemistry. Intense B(2) receptor
staining was observed on cells within the parenchyma of normal brain and tumor
but not on the vasculature of tumor or brain. An extensive network of CD-31 and
laminin staining was seen within and around the tumors in all groups, indicating
relatively rapid and robust changes in vascularity in response to the gliomas.
However, no consistent difference in vascularity between groups was observed to
account for the uptake differences seen with Cereport. Collectively, these data
offer initial preclinical empirical support for the hypothesis that Cereport's
effects on tumor permeability increase as the tumor grows, which we further
hypothesize is likely related to features of vascular development within the
tumor independent of numbers or general morphology of vessels. If a similar
phenomenon is shown to occur with infiltrating colonies from spontaneously
forming gliomas in humans or from newly emerging metastases in brain, these data
could impact the design and conduct of future trials using approaches intended to
enhance delivery of chemotherapeutics through increased permeability of the tumor
vascular barrier.
PMID- 10683291
TI - P75 neurotrophin receptor in the nucleus basalis of meynert in relation to age,
sex, and Alzheimer's disease.
AB - In a previous study we showed that the staining of tyrosine kinase receptors
(trks), which are high-affinity neurotrophin receptors (NTRs), is strongly
diminished in the nucleus basalis of Meynert (NBM) of Alzheimer's disease (AD)
patients, which may explain the lack of effect of NGF therapy in AD patients so
far. Since the literature regarding the expression of low-affinity NTRs was
rather controversial, the aim of the present study was to examine (i) possible
changes in the staining of low-affinity NTRs, i.e., p75 in the human NBM, an area
that is severely affected in AD; and (ii) alterations of these receptors in
relation to risk factors for AD, e. g., age, sex, and menopause. Brain material
of 31 controls and 30 AD patients was obtained at autopsy, embedded in paraffin,
and stained immunocytochemically. Using an image analysis system, we quantified
p75 immunoreactivity in both cell bodies and fibers at the level of the NBM. Our
results showed a significant diminishment of p75 immunoreactivity in both cell
bodies and fibers of NBM neurons in AD. We did not find any relationship between
age or sex and the expression of p75 receptor in cell bodies. However, there was
a clearly positive relationship between age and fiber staining in AD patients
which suggests the occurrence of a p75 transport disorder as an early event in
the process of AD. These observations and the earlier reported decreased staining
of trk receptors show that degeneration of NBM neurons in AD is associated with a
decreased neurotrophin responsiveness of NBM neurons in AD and that therapeutic
strategies should be directed toward upregulation of receptors or facilitation of
transport before an effect of neurotrophins in AD may be expected.
PMID- 10683292
TI - Intracerebral implantation of NGF-releasing biodegradable microspheres protects
striatum against excitotoxic damage.
AB - Intrastriatal implantation of genetically modified cells synthesizing nerve
growth factor (NGF) constitutes one way to obtain a long-term supply of this
neurotrophic factor and a neuronal protection against an excitotoxic lesion. We
have investigated if NGF-loaded poly(d,l-lactide-co-glycolide) microspheres could
represent an alternative to cell transplantations. These microspheres can be
implanted stereotaxically and locally release the protein in a controlled and
sustained way. In order to test this paradigm, the NGF release kinetics were
characterized in vitro using radiolabeled NGF, immunoenzymatic assay, and PC-12
cells bioassay and then in vivo after implantation in the intact rat striatum.
These microspheres were thus implanted into the rat striatum 7 days prior to
infusing quinolinic acid. Control animals were either not treated or implanted
with blank microspheres. The extent of the lesion and the survival of ChAT-,
NADPH-d-, and DARPP-32-containing neurons were analyzed. In vitro studies showed
that microspheres allowed a sustained release of bioactive NGF for at least 1
month. Microspheres implanted in the intact striatum still contained NGF after
2.5 months and they were totally degraded after 3 months. After quinolinic acid
infusion, the lesion size in the group treated with NGF-releasing microspheres
was reduced by 40% when compared with the control groups. A marked neuronal
sparing was noted, principally concerning the cholinergic interneurons, but also
neuropeptide Y/somatostatin interneurons and GABAergic striatofuge neurons. These
results indicate that implantation of biodegradable NGF-releasing microspheres
can be used to protect neurons from a local excitotoxic lesion and that this
strategy may ultimately prove to be relevant for the treatment of various
neurological diseases.
PMID- 10683293
TI - Changes in urinary bladder neurotrophic factor mRNA and NGF protein following
urinary bladder dysfunction.
AB - Spinal cord injury and cyclophosphamide-induced cystitis dramatically alter lower
urinary tract function and produce neurochemical, electrophysiological, and
anatomical changes that may contribute to reorganization of the micturition
reflex. Mechanisms underlying this neural plasticity may involve alterations in
neurotrophic factors in the urinary bladder. These studies have determined
neurotrophic factors in the urinary bladder that may contribute to reorganization
of the micturition reflex following cystitis or spinal cord injury. A
ribonuclease protection assay was used to measure changes in urinary bladder
neurotrophic factor mRNA (betaNGF, BDNF, GDNF, CNTF, NT-3, and NT-4) following
spinal cord injury (acute/chronic) or cyclophosphamide-induced cystitis
(acute/chronic). The correlation between urinary bladder nerve growth factor mRNA
and nerve growth factor protein expression was also determined. Each experimental
paradigm resulted in significant (P = 0.05-0.005) changes in urinary bladder
neurotrophic factor mRNA, although the magnitude of the changes differed between
paradigms. Urinary bladders from rats with acute spinal cord injury (4 days)
exhibited the largest increase in neurotrophic factor mRNA levels (betaNGF, 21
fold increase; BDNF, 78-fold increase; GDNF, 11-fold increase; CNTF, 5.5-fold
increase; NT-3, 10-fold increase; NT-4, 25-fold increase) relative to control
urinary bladders. More modest but significant increases were demonstrated for
urinary bladders from rats with chronic (4-6 weeks) spinal cord injury.
Significant increases in urinary bladder neurotrophic factor mRNA levels of
comparable magnitude were demonstrated following either acute or chronic
cyclophosphamide-induced cystitis. Increased abundance of urinary bladder nerve
growth factor mRNA was not always associated with increased total urinary bladder
nerve growth factor. Total urinary bladder nerve growth factor decreased
following acute or chronic cystitis despite increased abundance of nerve growth
factor mRNA. Urinary bladder nerve growth factor mRNA correlates with protein
measures 5-6 weeks following spinal cord injury but not earlier. The 5- to 6-week
time point coincided with the reemergence of the spinal bladder-to-bladder reflex
mechanisms following spinal cord injury. Discrepancies between two measures (mRNA
and protein) may reflect retrograde axonal transport of nerve growth factor to
the dorsal root ganglia (L6-S1). Retrogradely transported NGF may play a role in
altered lower urinary tract function following spinal cord injury or
cyclophosphamide-induced cystitis.
PMID- 10683294
TI - Macrophage cell-conditioned medium promotes cholinergic differentiation of
undifferentiated progenitors and synergizes with nerve growth factor action in
the developing basal forebrain.
AB - Conditioned medium from stimulated microglia and from the monocyte/macrophage
cell line (RAW 264.7; MC-CM) promotes the differentiation of cholinergic neurons
from undifferentiated progenitors in the septal nuclei and adjacent basal
forebrain (BF). We have studied the regulation of this process by measuring the
activity of choline acetyltransferase (ChAT) in cultured BF taken from embryonic
day 16 rat brain. Inhibition of either xanthine oxidase with allopurinol or
nitric oxide synthase with N(G)-monomethyl-l-arginine produces a small but
significant improvement in the efficacy of MC-CM while inclusion of pyrrolidine
dithiocarbamate, a hydroxyl radical scavenger widely used as an antioxidant,
lowers MC-CM-induced ChAT activity. Addition of nerve growth factor (NGF) but not
brain-derived neurotrophic factor or glial-derived neurotrophic factor together
with MC-CM has a synergistic effect on both ChAT activity and ChAT mRNA, raising
ChAT activity as much as 29-fold and ChAT mRNA almost 15-fold. While MC-CM raised
mRNA for trkA, the effect was not synergistic with NGF. mRNA for the common
neurotrophin receptor (p75NTR) showed a modest synergistic increase. Blockade of
the Ras/Raf/ERK [extracellular signal-regulated kinase, also known as mitogen
activated protein [(MAP) kinase] signal transduction pathway with either PD28059
(an inhibitor of MAP kinase/ERK kinase kinase or MEK) or N-acetyl-S-farnesyl-l
cysteine (an inhibitor of Ras farnesylation and, hence, activation) inhibited the
action of MC-CM. Moreover, a subpopulation of cells responded rapidly to MC-CM
with an increased appearance of phosphorylated ERK. Because NGF also utilizes
this pathway, synergy may occur along this signal transduction pathway.
PMID- 10683295
TI - Regulation of microglial tyrosine phosphorylation in response to neuronal injury.
AB - The regulation and substrate specificity of microglial phosphotyrosine (ptyr)
increases accompanying motor neuron degeneration in the rat spinal cord induced
by injection of the cytotoxic lectin, ricin, into sciatic nerve were examined
using specific enzyme inhibitors, immunohistochemistry, and Western blot
analyses. Optical density measurements of immunostained sections show that
microglial ptyr levels are elevated at 3 days postinjection. This period
coincides with initial stages of neuronal degeneration, and ptyr levels are
maximal at 7 days. We next asked whether this increase is due to increased
tyrosine kinase or decreased tyrosine phosphatase activities by assaying ptyr
immunostaining in animals that received osmotic pump infusion of the nonreceptor
tyrosine kinase inhibitor, herbimycin A, for the 7-day survival period. When
compared to the control ventral horn, microglial ptyr on the experimental side
was attenuated by at least 45% in the presence of herbimycin A. In order to
identify microglial substrates undergoing increased tyrosine phosphorylation,
Western blot analysis was performed on hemicord and punch biopsy samples from
control and experimental sides following ricin injection. A subset of two
proteins was identified whose increased ptyr was almost completely attenuated in
the herbimycin-A-treated animals. We conclude that the data support earlier
indications that upregulation of microglial tyrosine phosphorylation is a key
early event in response to neuronal injury. Further, this upregulation is due to
turning on tyrosine kinase activities, particularly nonreceptor kinases, and the
end product is phosphorylation of a very limited number of substrates. This
suggests the activation of specific tyrosine phosphorylation pathways, which may
represent critical therapeutic intervention points, rather than a global
response. The results are discussed in terms of recent cell culture models of
microglial activation and earlier data demonstrating elevated microglial ptyr in
neurodegenerative disease.
PMID- 10683296
TI - Dendrite loss is a characteristic early indicator of toxin-induced
neurodegeneration in rat midbrain slices.
AB - In rat brain substantia nigra catecholamine neurons in vitro, a sensitive
indicator of excitatory amino-acid-induced damage is dendritic degeneration that
precedes the loss of the cell body. The present study has shown that dendritic
loss is not specific for excitatory amino acids and is an early indicator of
neurodegeneration produced by numerous agents that initiate damage by different
primary cellular actions. Rats were anesthetised by fluothane inhalation and
killed, and the brain was rapidly removed. Three-hundred-micrometer-thick slices
containing substantia nigra were incubated for 2 h at 35 degrees C in the
presence or absence of kainic acid (50 microM), 1-methyl-4-phenylpyridinium ion
(10 or 50 microM), ouabain (10 or 30 microM), 6-hydroxydopamine (10 or 100
microM), potassium cyanide (100 microM or 1 mM), or elevated extracellular
potassium chloride (25, 50, or 100 mM). The slices were fixed and recut into thin
sections (30 micrometer) and substantia nigra dopamine neurons were immunolabeled
for tyrosine hydroxylase coupled to diaminobenzidine. Both the cell body and the
extensive dendritic projections were immunolabeled. Each agent caused a similar
pattern of toxicity including loss of tyrosine-hydroxylase-immunolabeled
dendrites at lower concentrations and damage to, or disintegration of, the cell
bodies at higher concentrations. For example, 100 microM potassium cyanide
reduced the proportion of substantia nigra neurons which exhibited dendrites from
66 +/- 4% (SEM) in controls to 54 +/- 7%, without obvious changes in cell bodies.
After 1 mM potassium cyanide, only 13 +/- 2% of substantia nigra neurons retained
dendrites and cell bodies were shrunken or disintegrated. Loss of dendrites was
also evident in substantia nigra neurons stained with cresyl violet or
immunolabeled for microtubule-associated protein 2. The findings suggest that
disruption of the dendritic arbor is an early indicator of neurodegeneration,
irrespective of how this is initiated. The approach that we have developed may
therefore prove valuable in investigating the mechanisms of degeneration of
catecholamine neurons.
PMID- 10683297
TI - Differential expression of S100beta and glial fibrillary acidic protein in the
hippocampus after kainic acid-induced lesions and mossy fiber sprouting in adult
rat.
AB - The expression of S100beta and glial fibrillary acidic protein (GFAP) was
analyzed following bilateral injection of kainic acid (KA), a glutamate
derivative, into the CA3 region of the adult rat hippocampus. This treatment
produces a progressive degeneration of the pyramidal neurons of the hippocampus
while sparing the granule cells of the dentate gyrus which undergo sprouting of
their axons in the supragranular layer. Messenger RNA and protein levels were
measured, by Northern blot and ELISA, in the hippocampus of lesioned and sham
operated rats 1, 7, and 30 days after KA injection. A significant increase of
GFAP and its mRNA was demonstrated at each time point, whereas S100beta mRNA
levels were significantly enhanced only 30 days after the KA injection and the
levels of S100beta protein remained unchanged at all time points. However, when
analyzed by immunohistochemistry the S100beta showed clear changes in its
expression and distribution depending on the region considered. One month after
KA injection, S100beta immunoreactivity was considerably reduced in the stratum
radiatum of CA3 region, but there was increased S100beta immunoreactivity in the
stratum moleculare. In particular, a notable band of S100beta positive,
hypertrophic astrocytes appeared in the supragranular layer of the dentate gyrus
where the sprouting of mossy fiber collaterals was detected by Timm's staining.
These data show for the first time that an increase in S100beta expression in
subpopulations of reactive astrocytes may be involved in the structural
reorganization of the hippocampus following KA-induced neurodegeneration.
PMID- 10683298
TI - Search for a mutation in the tau gene in a Swiss family with frontotemporal
dementia.
AB - Frontotemporal dementia (FTD) is considered to have a heterogeneous aetiology. To
date the tau gene located on chromosome 17 has been shown to be implicated in the
pathogenesis of several FTD families with parkinsonism, the so called FTDP-17
families. The mutations reported so far are located within exons 9 to 13, a
region coding for the microtubule-binding sites. They are causing various
cytoskeletal disturbances. We are describing here the main clinical and
neuropathological features of a Swiss FTD family with members presenting a FTDP
like clinical phenotype. However, if we except two silent polymorphic sites at
position 227 and 255 in exon 9, neither a known FTDP-17 mutation nor a novel one
was detected in this region of the tau gene. Thus, the existence of a yet unknown
mechanism of neurodegeneration, other than via mutations near or within the
microtubule-binding sites, or the exon 10 splice sites of the tau gene, has to be
considered to explain dementia in this family. A mutation in another gene is
still possible.
PMID- 10683299
TI - Behavioral and metabolic changes in immature rats during seizures induced by
homocysteic acid: the protective effect of NMDA and non-NMDA receptor
antagonists.
AB - Bilateral intracerebroventricular infusion of dl-homocysteic acid (DL-HCA) (600
nmol on each side) to immature 12-day-old rats induced generalized clonic-tonic
seizures, recurring frequently for at least 90 min, with a high rate of survival.
Electrographic recordings from sensorimotor cortex, hippocampus, and striatum
demonstrated isolated spikes in the hippocampus and/or striatum as the first sign
of dl-HCA action. Generalization of epileptic activity occurred during
generalized clonic-tonic seizures, but electroclinical correlation was very low;
dissociation between EEG pattern and motor phenomena was common. Seizures were
accompanied by large decreases of cortical glucose and glycogen and by
approximately 7- to 10-fold accumulation of lactate. ATP and phosphocreatine
(PCr) levels remained unchanged even during longlasting (3 h) convulsions.
Metabolite levels became normalized during the recovery period (24 h). The
examination of the effect of selected antagonists of NMDA [AP7 (18.5 and 37
mg/kg, respectively), MK-801 (0.5 mg/kg)] and non-NMDA [NBQX (10, 15 and 30
mg/kg, respectively)] receptors revealed that seizures could be attenuated or
prevented (depending on the dose employed) by antagonists of both NMDA and non
NMDA receptors, as evaluated not only according to the suppression of behavioral
manifestations of seizures, but also in terms of the protection of metabolite
changes accompanying seizures. All antagonists employed, when given alone in the
same doses as those used for seizure protection, did not influence metabolite
levels, with the exception of increased glucose concentrations. Furthermore, the
pronounced anticonvulsant effect could be achieved by the combined treatment with
low subthreshold doses of NMDA (AP7) and non-NMDA (NBQX) receptor antagonists,
which may be of potential significance for a new approach to the treatment of
epilepsy.
PMID- 10683300
TI - Comparison of tyrosine hydroxylase and preproenkephalin expression in rat adrenal
medullary explants in vitro and transplanted into subarachnoid space.
AB - When adrenal medullary cells are cultured in vitro, tyrosine hydroxylase (TH)
mRNA, preproenkephalin (PPEnk) mRNA, and methionine enkephalin (Mek)
immunoreactivity was markedly increased compared with intact adrenal medullary
cells in situ, suggesting an increased biosynthesis of catecholamines and
enkephalin-containing peptides. In transplanted adrenal medullary cells in vivo,
TH mRNA and TH immunoreactivity are still apparent for at least 1 year after
transplantation, indicating continued capacity for catecholamine biosynthesis.
PPEnk mRNA levels in surviving adrenal medullary grafted cells increased,
particularly in the first week after transplantation, and remained above levels
found in the intact adrenal gland for at least 1 year after transplantation.
These results support other studies in our laboratory, suggesting that adrenal
medullary transplants reduce pain by synthesis and secretion of both
catecholamines and enkephalin-containing peptides. The differences in expression
of TH mRNA and PPEnk mRNA in the adrenal medulla in situ, in explants in culture
and in transplants in the spinal subarachnoid space, indicate that the mechanisms
regulating the expression of neurohumoral factors depend upon environmental
factors extrinsic to the medullary cells themselves.
PMID- 10683301
TI - Enkephalin and aFGF are differentially regulated in rat spinal motoneurons after
chemodenervation with botulinum toxin.
AB - Botulinum toxin is used to induce transient graded paresis by chemodenervation in
the treatment of focal hyperkinetic movement disorders. While the molecular
events occurring in motoneurons after mechanical nerve lesioning leading to
muscle paresis are well known, they have been investigated to a lesser extent
after chemodenervation. We therefore examined the expression of enkephalin (ENK),
acidic fibroblast growth factor (aFGF), neurotensin (NT), galanin (GAL),
substance P (SP), vasoactive intestinal polypeptide (VIP), and neuropeptide Y
(NPY) in rat spinal motoneurons after chemodenervation of the gastrocnemius. In
order to precisely localize the motoneurons targeting the injection site,
retrograde tracing was performed in additional rats by using Fluorogold
injections. ENK expression was upregulated in the region corresponding to the
Fluorogold positive motoneurons, but also on the contralateral side and in more
distant parts of the spinal cord. The highest upregulation occurred 7 to 14 days
after injections and decreased over a period of three months. At 8 days, aFGF was
slightly downregulated in all regions studied, single motoneurons showed NT
expression, while expression of GAL, SP, VIP, and NPY could be detected neither
in controls nor in toxin-treated animals. These alterations in gene expression
were strikingly different from those described after axotomy. Our present
findings give additional demonstration of the considerable plasticity of the
adult spinal cord after botulinum toxin treatment.
PMID- 10683302
TI - Expression of receptors for complement anaphylatoxins C3a and C5a following
permanent focal cerebral ischemia in the mouse.
AB - In the present study, we have examined the expression of anaphylatoxin C3a and
C5a receptors (C3aR and C5aR) at the mRNA and protein levels in ischemic brain
tissues following permanent middle cerebral artery (MCA) occlusion in the mouse.
C3aR and C5aR mRNAs were both detected by semiquantitative reverse transcription
and polymerase chain reaction (RT-PCR) and the cellular distribution of each
receptor was analyzed by immunohistochemistry. Significant increases in the
expression of C3aR and C5aR mRNAs in the ischemic cortex were observed; the
expression of both reached a peak at 2 days after MCA occlusion (4.3- and 3.4
fold increases, respectively, compared with nonoperated control cortical samples;
P < 0.00625 with Bonferroni's correction, n = 3). C3aR and C5aR stainings were
found constitutively on neurons and astrocytes. In ischemic tissues, we observed
that C3aR and C5aR were expressed de novo on endothelial cells of blood vessels,
at 6 h and 2 days after MCA occlusion, respectively. C3aR and C5aR immunostaining
was increased in macrophage-like cells and reactive astrocytes 7 days
postocclusion. C3a and C5a may play an important role in promoting inflammatory
and/or repair processes in the ischemic brain by regulating glial cell activation
and chemotaxis.
PMID- 10683303
TI - Susceptibility to beta-amyloid-induced toxicity is decreased in goto-kakizaki
diabetic rats: involvement of oxidative stress.
AB - The response of synaptosomes isolated from Wistar non-diabetic rats and Goto
Kakizaki (GK) diabetic rats to the beta-amyloid fragment Abeta25-35 was compared.
The synaptosomal redox activity, evaluated by the MTT [3-(4,5-dimethylthiazol-2
yl)-2,5-diphenyltetrazolium bromide] assay, was shown to be decreased in GK rats
(72.8 +/- 7.45% of MTT reduction). However, the reduction of MTT was decreased in
synaptosomes of Wistar rats upon Abeta25-35 treatment (84.47 +/- 3.73%), while in
GK rats it was not affected. Abeta25-35 induced lipid peroxidation in
synaptosomes of Wistar rats, but not in that of GK rats, leading to an 1.5-fold
increase in thiobarbituric acid reactive substances (TBARS) levels. In the
absence of Abeta25-35, basal TBARS levels were 1.6-fold higher in GK rats. In the
former preparations, the content in vitamin E was also higher (2-fold). A
decrease in ATP levels, of about 2-fold, was observed in synaptosomes of Wistar
rats treated with Abeta25-35, while no significant changes were observed in
synaptosomes of GK rats. No significant differences between the two groups were
detected in the basal ATP levels. The extrasynaptosomal accumulation of aspartate
and glutamate increased upon Abeta25-35 treatment, only in synaptosomes of Wistar
rats (aspartate and glutamate accumulation increased by 1.1-fold and 1.5-fold,
respectively), while the accumulation of glycine increased in both Wistar (by 1.8
fold) and GK (by 2.2-fold) rats. No statistical differences in the basal
accumulation of aminoacids were observed. These results show that synaptosomes of
GK diabetic rats have a lower redox activity, but are less susceptible to the
Abeta25-35-induced toxicity. Data also suggest that oxidative stress occurs in
this hyperglycemia animal model and that an increase in the antioxidant defense
systems may exert protection against toxic insults. This mechanism, occuring in
the early phases of diabetes, may correspond to an adaptive response.
PMID- 10683304
TI - Lesion-induced increase of BDNF is greater in the striatum of young versus old
rat brain.
AB - Young (4-5 month old) and old (32-34 month old) Brown Norway/F344 hybrid rats
were given unilateral 6-OHDA lesions of the nigrostriatal pathway. Four weeks
later tissue from the lesioned or intact striatum or ventral midbrain was
dissected and analyzed for brain-derived neurotrophic factor (BDNF) protein
levels using an enzyme-linked immunosorbent assay. BDNF protein content was
greater in the lesioned striatum than in the intact striatum for all young rats,
and the increased BDNF content in the lesioned striatum of young rats was
directly correlated with severity of lesion as determined by rotational scores.
BDNF content in the lesioned striatum increased in less than half of the old rats
and was not significantly different than BDNF content in the intact striatum.
BDNF content in the lesioned substantia nigra/ventral tegmental area (SN/VTA) was
greater than BDNF content in the intact SN/VTA for both young and old rats. These
data suggest that an age-related difference in activity of at least one
neurotrophic factor, BDNF, occur within the denervated striatum following a
neurotoxic lesion of the nigrostriatal pathway.
PMID- 10683305
TI - A new morphometric analysis of the hominid pelvic bone.
AB - This study is based upon a new morphometric technique providing both size and
shape variables. It has been applied to 189 pelvic bones of extant humans and
African apes as well as to 13 hominid pelvic bones of various taxonomic status.
The main aim of this work is to include such fossil bones in the same study in
order to set a synthetic comparison of their shape in the light of the yardstick
given by the African ape/human pelvic bone comparison. To do so, ratio diagrams
are chosen because they are simple and very expressive tools with which to
present such comparisons. Shape differences are very well illustrated and
quantified by this technique. The ilium appears to be the most different of the
three parts of the pelvic bone. Compared to these differences, discrepancies
between fossil hominid and extant human bones are of a totally different scale.
This shows the architectural unity related to the acquisition of bipedalism by
hominids. It is nonetheless possible to detect two levels of difference. The
first separates Australopithecus from Homo and could be seen as reflecting
locomotor differences between both genera. The second splits both Homo erectus
and Neanderthal from modern human pelvic bones. It appears from the hominid
fossil record of pelvic bones that two periods of stasis exist and are separated
by a period of very rapid evolution corresponding to the emergence of the genus
Homo. We are of the opinion that the same could be true for the split between
African ape and hominid lineages at the end of the Miocene.
PMID- 10683306
TI - The human chin revisited: what is it and who has it?
AB - Although the presence of a "chin" has long been recognized as unique to Homo
sapiens among mammals, both the ontogeny and the morphological details of this
structure have been largely overlooked. Here we point out the essential features
of symphyseal morphology in H. sapiens, which are present and well-defined in the
fetus at least as early as the fifth gestational month. Differences among adults
in expression of these structures, particularly in the prominence of the mental
tuberosity, are developmental epiphenomena and serve to emphasize the importance
of studying this region in juveniles whenever possible. A survey of various
middle to late Pleistocene fossil hominids for which juveniles are known reveals
that these features are present in some late Pleistocene specimens assigned to H.
sapiens, but not in all of the presumed anatomically modern H. sapiens (i.e.,
Qafzeh 8, 9, and 11). The adult specimens from Skhul, as well as the adult Qafzeh
7 specimen, are similarly distinctive in symphyseal morphology. Neanderthals are
quite variable in their own right, and they as well as other middle to late
Pleistocene fossils lack the symphyseal features of H. sapiens. Some of the
latter are, however, seen in the Tighenif (Ternifine) mandibles.
PMID- 10683307
TI - Isometric scaling of maxillary sinus volume in hominoids.
AB - Previous hypotheses of maxillary sinus size evolution have proposed one or more
changes in the volume of the structure across hominoid phylogeny. These
hypotheses have been used subsequently to support the phylogenetic placement of
fossil taxa relative to the living Hominoidea. The null hypothesis, that no
change in sinus volume independent of size has occurred in ape evolution, is
evaluated here by scaling analysis. Mixed sex samples of adult dry crania for the
extant ape genera were examined by computer tomography imaging and the volume of
the maxillary sinus was obtained. Sinus volume was then regressed, using both
least squares and reduced major axis models, against cranial size variables. The
results clearly demonstrate that the null hypothesis of no change in relative
sinus volume cannot be rejected; thus, there is no support for hypotheses that
maxillary sinus volume, independent of cranial size, has changed in the course of
hominoid evolution. This result, in turn, has implications for the phylogenetic
placement of fossil taxa and highlights the need for the careful delineation of
character states in studies of hominoid systematics.
PMID- 10683308
TI - Cranial discrete traits in the middle pleistocene humans from Sima de los Huesos
(Sierra de Atapuerca, Spain). Does hypostosis represent any increase in
"ontogenetic stress" along the Neanderthal lineage?
AB - Cranial discrete traits may be regarded as markers of dynamic responses to
general and local perturbations of the morphogenetic pattern, particularly when
they are viewed and examined in terms of hypostosis vs. hyperostosis. There are
indications, in fact, that the variation between these two opposite conditions
relates to mechanical stress suffered by the bony structures during early stages
of growth and development. In a previous comparison between Neanderthals and
modern humans, variable degrees and contrasting distribution patterns of
hypostosis were found [Manzi et al. (1996), JHE30: 511-527]. In the present
paper, the occurrence, expression and cranial distribution of 20 hypo
hyperostotic traits are examined in the Middle Pleistocene sample from Atapuerca
Sima de los Huesos (Spain), with the principal aim being to test whether or not
the degree of cranial hypostosis increases during the evolution of the
Neanderthals. Other Middle Pleistocene representatives of the genus Homo (Kabwe
and Petralona), the Italian Neanderthals, and a large recent European sample are
also considered. A general consistency between the gradual appearance and
stabilization of the Neanderthal cranial features and the results of the present
analysis is found and is interpreted as an indication that hypostosis does mark
the occurrence of "ontogenetic stress". As suggested more than half a century ago
by S. Sergi, an increase in "ontogenetic stress" in the Neanderthal lineage could
result from the relationship between intracranial pressures and other
(heterochronic) effects produced by the growth of a large brain (encephalization)
and the ossification of an archaic (platycephalic) cranial vault.
PMID- 10683309
TI - Macaca (Primates, Cercopithecidae) from the late Miocene of Spain.
PMID- 10683310
TI - Novel roles for integrins in the nervous system.
PMID- 10683311
TI - The nuclear accumulation of a variant epidermal growth factor receptor (EGFR)
lacking the transmembrane domain requires coexpression of a full-length EGFR.
AB - Both the epidermal growth factor (EGF) and its receptor (EGFR) accumulate in the
nucleoplasm during liver regeneration. This localization in a nonmembraneous
compartment presents a challenge in that the standard form of EGFR is a
transmembrane protein and suggests the existence of a variant, soluble form of
EGFR. To investigate the localization of such a putative EGFR splice variant, we
generated a transmembrane-devoid form of EGFR. We placed this transmembrane
negative [TM(-)] EGFR construct and full-length wild-type (wt) EGFR either in a
retroviral transfection vector or in an inducible expression vector. Mouse 3T3
cells, which express endogenous EGFR, were transfected with the TM(-) EGFR
construct. The expression of these TM(-) EGFR, detected with a specific antibody
against human EGFR using a confocal laser-scanning microscope, was predominantly
found in the cytoplasm with no nuclear localization. After an overnight
incubation with EGF the TM(-) EGFR accumulated in the nucleus. In mouse NR6
cells, which lack endogenous EGFR, transfected TM(-) EGFR were found in the
cytoplasm, but incubation with EGF did not result in a nuclear accumulation of
TM(-) EGFR. However, NR6 cells transfected with both TM(-) EGFR and wt EGFR
showed nuclear accumulation after EGF treatment. These results suggest that both
the wt EGFR and the TM(-) EGFR are required for nuclear accumulation of TM(-)
EGFR and may implicate a model of homotypic recognition and translocation of a
splice variant of EGFR.
PMID- 10683312
TI - Transcriptional regulation of herpes simplex virus type 1 ICP0 promoter by virion
protein 16.
AB - HSV regulatory proteins ICP0 and VP16 independently regulate transcription of the
ICP0 gene during virus infection. In this study, we tried to determine the
possible regulatory mechanism of ICP0 expression during virus infection. Among
eight putative VP16 binding sites present in the ICP0 regulatory sequence, the
most upstream one alone was sufficiently responsive to VP16-mediated activation.
When the G/C-rich sequence present in front of the last TAATGARAT sequence of the
ICP0 promoter was either deleted or point mutated, the activational effect of
VP16 on the promoter was completely abolished. Furthermore, according to the gel
mobility shift assay using a labeled double-stranded oligonucleotide derived from
the G/C-rich sequence in the ICP0 promoter, specific protein binding to the probe
was clearly demonstrated and was approximately fivefold upregulated by HSV-1
infection. Therefore, the G/C-rich sequence might play a critical role in VP16
mediated activation of the ICP0 promoter and the effect may be a result of the
enhanced binding of a protein to the G/C-rich sequence during virus infection.
PMID- 10683314
TI - Structure of the Mesothelin/MPF gene and characterization of its promoter.
AB - Mesothelin is a cell-surface antigen of unknown function that is expressed in a
highly tissue-specific manner. Expression of the protein is limited to
mesothelium, the tissue forming the pleural, pericardial, and peritoneal
membranes. The purpose of this study was to characterize the gene and identify
elements responsible for its transcription. The gene contains an 1884-bp open
reading frame encoded by 15 exons occupying 8 kb of human chromosome 16. An 1850
bp region of genomic DNA at the 5' end of the gene encompassing the proposed
transcriptional start site was cloned. This region lacks a TATA box and other
regulatory elements such as SP1 sites, which are commonly found in promoters.
Transient transfection analyses demonstrated that mesothelium-specific control
elements are present within the 1.85-kb region. Minimal constitutive promoter
elements were localized to a 317-bp region. Tissue-specific enhancer elements
upstream of the minimal promoter were found to activate transcription from the
homologous and a heterologous promoter in a position- and orientation-independent
manner.
PMID- 10683313
TI - Increased chitin synthesis in response to type II myosin deficiency in
Saccharomyces cerevisiae.
AB - We reported previously that the chitin content in cell walls of type II myosin
deficient Saccharomyces cerevisiae strains is increased relative to wild-type
cells suggesting that increased chitin synthesis is induced in these strains. In
the present study, we have performed enzyme activity assays for chitin synthases
1, 2, and 3 to determine the enzyme isoform(s) involved. To determine if
transcriptional regulation is involved, we conducted quantitative mRNA assays of
the corresponding chitin synthase genes. We show that the enzyme activities of
all three chitin synthases increase substantially over the wild-type strain while
eight- and twofold increases in the mRNA levels for chitin synthases 1 and 3 were
detected. Increases in enzyme activities and mRNA levels were not proportional.
We conclude that the enzyme activities for all three chitin synthases are
elevated in this strain and that this increase is mediated mainly by a
posttranslational mechanism(s). The heightened sensitivity to osmotic stress and
the corresponding increase in cell wall chitin content reported in these strains
are consistent with a compensatory "stress response" mechanism induced by
abnormal cell wall assembly.
PMID- 10683315
TI - CpG-specific common commitment in caspase-dependent and -independent cell deaths.
AB - Cell death in mammals seems to have caspase-dependent and -independent pathways
unlike that in Caenorhabditis elegans where CED-3 protease activation is the
central command. A recent suggestion to define apoptosis as the caspase-dependent
or caspase-committed cell death form and leave cell death committed by other
pathways as just cell death was meant to categorize the apparent divergence in
mammalian cell death pathways. However, we show CpG oligonucleotides (ODN)
blocking caspase-dependent fas(CD95) ligand-mediated apoptosis as well as caspase
independent etoposide-mediated apoptosis and etoposide-zVAD-mediated necrosis.
CpG specificity was demonstrated by reversing the CpG motif or replacing it with
a methylated motif (mCpG) which failed to inhibit. CpG ODN blocked CpG-specific
DNA cleavage by rare-cutting NotI restriction, which produced a megabase cleavage
pattern similar to that in the fasL and etoposide cell death inductions. CpG ODN
inhibition was similar to that by CpG-specific SssI methylase. A common CpG
specific commitment point preceding caspase-dependent and -independent cell death
pathways was suggested. CpG-specific modulation is a key epigenetic mechanism in
genomic imprinting, resisting nuclease restriction, and patterning of chromatin
conformations. It is now shown to have a powerful effect modulating cell death.
PMID- 10683317
TI - Regulation of sialyltransferase expression by estradiol and 4-OH-tamoxifen in the
human breast cancer cell MCF-7.
AB - We have addressed the effects of estradiol and 4-OH-tamoxifen on the expression
of five sialyltransferases in the hormono-dependent MCF-7 cell line using a
Multiplex RT-PCR approach. Estradiol induced a statistically significant increase
in ST3Gal III and a decrease in ST6Gal I, whereas the two other enzymes, ST3Gal
IV and ST3Gal I, are not modified and expression of the fifth enzyme, ST3Gal II,
was very low or not detectable. Estradiol effects were dose dependent and
completely antagonized by 4OH-tamoxifen. In addition, there is no direct relation
between cellular proliferation and sialyltransferase expression. This suggests
that ST3Gal III and ST6Gal I could be used as supplementary markers of hormono
sensitivity in breast cancer.
PMID- 10683316
TI - CYP2B1 is regulated by C/EBP alpha and C/EBP delta inlung epithelial cells.
AB - Pulmonary expression of several cytochrome P450 (CYP) monooxygenases is detected
late in gestation. Little is known of the factors involved in this
differentiation-dependent expression. C/EBP factors are known regulators of
differentiation and differentiation-dependent gene expression in several tissues.
In this study we demonstrate the importance of C/EBP alpha and C/EBP delta in
pulmonary epithelial CYP2B1 gene expression. A 1.3 kb CYP2B1 promoter fragment
which recently has been shown to confer lung tissue- and cell-specific expression
of CYP2B1 in transgenic mice was used in transient transfection studies. Both
C/EBP alpha and C/EBP delta transactivated the CYP2B1 promoter in the lung
epithelial cell lines A549 and NCI-H441. C/EBP alpha in nuclear extracts from
isolated rat primary bronchiolar Clara cells was capable of interacting with a
C/EBP-binding site in the proximal CYP2B1 promoter. Site-directed mutagenesis
studies showed that this proximal C/EBP-binding site is necessary for
transactivation of the CYP2B1 gene by C/EBP alpha and C/EBP delta. Thi study
shows that C/EBP factors have a role in pulmonary CYP2B1 expression and suggests
that these transcription factors may be important for the differentiation
dependent expression of CYP2B1 in the lung.
PMID- 10683318
TI - The expression of membrane-associated 67-kDa laminin receptor (67LR) is modulated
in vitro by cell-contact inhibition.
AB - The interaction of cells with their substratum is an important determinant of
cell behaviour, influencing attachment, proliferation, and motility. Such
interactions are mediated by cell surface receptors which bind to attachment
factors, like the glycoprotein laminin in basement membranes. We have previously
shown that expression of the 67-kDa laminin receptor (67LR) is elevated in
proliferating retinal microvasculature compared with mature, quiescent vessels.
Here, we examined 67LR mRNA and protein expression in primary cultures of retinal
microvascular endothelial cells (RMEC) and in the breast cancer cell-line T47D
during stages of contact inhibition. In both cell types, the expression levels of
67LR mRNA and membrane-associated 67LR protein were significantly increased
during the proliferative phases of monolayer formation. As the cells achieved
contact inhibition, 67LR expression was reduced to comparatively low levels.
Thus, the differential expression of 67LR between dividing and contact-inhibited
cells may indicate a role for this receptor during proliferative processes.
PMID- 10683319
TI - Induction and secretion of the chemokines interleukin-8 and monocyte chemotactic
protein-1 in human immature leukemia cell lines.
AB - We investigated expression and secretion of the chemokines interleukin-8 (IL-8)
and monocyte chemotactic protein-1 (MCP-1) in human myeloid cell lines.
Quantitative determination by ELISA revealed a significant constitutive
production of both chemokines in the cell lines HL-60 and NB-4 (>1000 pg/ml IL-8
and >400 pg/ml MCP-1 per million cells), while in the cell lines EOL-1, KASUMI-1
and KG-1 only 10-100 pg/ml IL-8 and MCP-1 were detected. Tetradecanoyl phorbol
acetate (TPA) strongly increased the IL-8 and MCP-1 amounts in the culture
supernatants of all five cell lines. The TPA-induced NB-4 produced the largest
amounts of both chemokines (>40,000 pg/ml). The strongest induction was seen in
EOL-1 (>100-fold increase). Besides TPA, tumor necrosis factor-alpha (TNF alpha)
also distinctively enhanced IL-8 and MCP-1 production. The calcium ionophore A
23187 and thapsigargin, an inhibitor of the Ca(2+)-ATPase, differentially induced
IL-8 and MCP-1 secretion in the cell lines investigated, suggesting that, at
least in some cell lines, intracellular free Ca(2+) might be important for
chemokine secretion. Dexamethasone significantly prevented the IL-8 and MCP-1
production of stimulated cells, emphasizing the potent anti-inflammatory property
of glucocorticoids. Similarly, the protein kinase inhibitor staurosporine clearly
decreased the TPA-induced chemokine secretion in NB-4 cells, indicating the
involvement of protein kinases in the signal transduction pathway which leads to
enhanced chemokine secretion.
PMID- 10683320
TI - Proteolytic processing of Marburg virus glycoprotein.
AB - Processing of the transmembrane glycoprotein (GP) of Marburg virus involved the
conversion of an endo H-sensitive, ER-specific form into an endo H-resistant,
Golgi-specific precursor that was cleaved into GP(1) and GP(2). Cleavage was
mediated by furin or another subtilisin-like endoprotease with similar substrate
specificity as indicated by mutational analysis of the cleavage site and
inhibition using peptidyl chloromethylketones. Mature GP consisted of disulfide
linked GP(1) and GP(2) subunits.
PMID- 10683321
TI - Canine cyclin T1 rescues equine infectious anemia virus tat trans-activation in
human cells.
AB - Human immunodeficiency virus-1 Tat protein and human Cyclin T1 mediate
transcriptional activation by enhancing the elongation efficiency of RNA
polymerase II. Activation of transcription of the related equine infectious
anemia virus (EIAV) requires a similar protein known as eTat, which does not
function in human cells. Expression of equine Cyclin T1 in human cells rescues
eTat function, suggesting a general mechanism of transcription activation among
lentiviruses. Here we present the cloning of Cyclin T1 from canine D17
osteosarcoma cells, which support EIAV transactivation, and show that canine
Cyclin T1 confers eTat transactivation to human cells. A two-amino-acid change,
from 79-proline-glycine-80 to 79-histidine-arginine-80, confers on the human
Cyclin T1 the ability to cooperate with eTat in transcriptional activation. These
findings suggested that the regions of Cyclin T1 that interact with lentiviral
Tat proteins and TAR RNA elements form an extended domain, which very likely has
a conserved fold.
PMID- 10683322
TI - Peripheral blood mononuclear cells of HIV- and HCV-antibody-positive individuals
contain HCV RNA but No HCV DNA despite evidence for reverse transcription of HIV
RNA into DNA.
AB - Following reports of the finding of cDNA of RNA viruses in cells containing an
endogenous retrovirus-encoded reverse transcriptase, we looked for the presence
of hepatitis C virus (HCV) DNA in peripheral blood mononuclear cells (PBMC) of
injecting drug users seropositive for both HCV and human immunodefiency virus
(HIV). We tested serial PBMC samples from four HCV infected individuals; one was
seronegative for HIV, two seroconverted for HIV during follow-up, and one was
seropositive for HIV throughout the study period. HCV RNA was found in PBMC and
plasma samples at all time points tested. Similarly, HIV RNA was found in all
PBMC and plasma samples following HIV seroconversion. In contrast, no HCV DNA was
detected in any PBMC sample, whereas HIV DNA was found in all tested PBMC samples
following HIV seroconversion, indicative of active HIV reverse transcriptase in
these PBMC samples. These results do not support the hypothesis that HCV viraemia
is related to retrotranscription of the HCV RNA genome into DNA in peripheral
blood mononuclear cells coinfected with HIV. The potential of HIV RT to
retrotranscribe HCV RNA into DNA awaits studies of liver cells coinfected with
HCV and HIV.
PMID- 10683323
TI - Establishment of latent herpes simplex virus type 1 infection in resistant,
sensitive, and immunodeficient mouse strains.
AB - Productive infection with herpes simplex virus (HSV) type 1 is limited by both
innate and adaptive immune mechanisms. The purpose of the current study was to
determine whether these mechanisms also play a role in the establishment of
latent HSV infection. First we examined the trigeminal ganglia (TG) of severe
combined immunodeficiency (SCID), interferon-gamma knockout (GKO), and beige (a
strain deficient in natural killer cell activity) mice following ocular
inoculation with HSV. Although infection of SCID mice was invariably lethal, we
consistently found latently infected neurons in the TG of these animals at 2-4
days postinoculation. HSV infection of GKO and beige mice, while not lethal, was
characterized by a greater number of productively infected TG neurons and/or a
delay in the time to peak productive infection compared to C57BL/6 controls.
However, as assayed by both in situ hybridization for LAT expression and
quantitative PCR (Q-PCR) for viral DNA, we found that HSV established a latent
infection in GKO and beige mice as efficiently as in C57BL/6 controls. We
subsequently examined the TG of "HSV-sensitive" strains of mice (Swiss-Webster,
CBA, and BALB/c) following ocular infection with HSV. At the peak of acute
ganglionic infection the number of productively infected TG neurons in each of
these mouse strains was about sevenfold greater than in the "HSV-resistant"
strain C57BL/6, consistent with previously reported differences in susceptibility
to lethal challenge with HSV. However, as assayed by both in situ hybridization
for LAT and Q-PCR for viral DNA, we found that HSV established a latent infection
in Swiss-Webster, CBA, and BALB/c mice as efficiently as in C57BL/6 controls. We
conclude that HSV efficiently establishes latent infection in the TG of mice in
the absence of innate and adaptive immune mechanisms that are essential for
limiting productive viral infection.
PMID- 10683324
TI - Genetic dissection of the multiple functions of alfalfa mosaic virus coat protein
in viral RNA replication, encapsidation, and movement.
AB - Coat protein (CP) of alfalfa mosaic virus (AMV) binds as a dimer to the 3'
termini of the three genomic RNAs and is required for initiation of infection,
asymmetric plus-strand RNA accumulation, virion formation, and spread of the
virus in plants. A mutational analysis of the multiple functions of AMV CP was
made. Mutations that interfered with CP dimer formation in the two-hybrid system
had little effect on the initiation of infection or plus-strand RNA accumulation
but interfered with virion formation and reduced or abolished cell-to-cell
movement of the virus in plants. Six of the 7 basic amino acids in the N-terminal
arm of CP (positions 5, 6, 10, 13, 16, and 25) could be deleted or mutated into
alanine without affecting any step of the replication cycle except systemic
movement in plants. Mutation of Arg-17 interfered with initiation of infection
(as previously shown by others) and cell-to-cell movement of the virus but not
with plus-strand RNA accumulation or virion formation. The results indicate that
in addition to the RNA-binding domain, different domains of AMV CP are involved
in initiation of infection, plus-strand RNA accumulation, virion formation, cell
to-cell movement, and systemic spread of the virus.
PMID- 10683325
TI - The HTLV receptor is a widely expressed protein.
AB - The receptor for human T-cell leukemia virus type 1 (HTLV-1) was found to be
expressed on a broad range of cell lines derived from multiple species. Receptor
expression was assessed using human immunodeficiency virus type 1 particles,
pseudotyped with the HTLV-1 envelope glycoprotein, and expressing luciferase
under the control of an SV40 enhancer and promoter. Infection by pseudotyped
virus was blocked with neutralizing antibodies to HTLV-1, and infection was
dependent on the presence of the cleavage and fusogenic sequences in the envelope
protein precursor. Trypsin treatment of susceptible target lymphocytes reduced
entry. Entry was partially resistant to ammonium chloride.
PMID- 10683326
TI - Japanese encephalitis DNA vaccine candidates expressing premembrane and envelope
genes induce virus-specific memory B cells and long-lasting antibodies in swine.
AB - Swine are an important amplifier of Japanese encephalitis (JE) virus in the
paradomestic environment. In this study, two JE DNA vaccine candidates were
evaluated for immunogenicity in swine. Both vaccine plasmids encode a cassette
consisting of the signal of premembrane (prM), prM, and envelope (E) coding
regions of JE virus. One plasmid, designated pcJEME, is based on a commercial
vector (pcDNA3), whereas the other plasmid, designated pNJEME, is based on a
vector (pNGVL4a) designed to address some of the safety concerns of DNA vaccine
use. No differences were detected in the immunogenicity of these two plasmids in
mice or swine. Swine immunized with the DNA vaccines at a dose of 100 to 450
microgram at an interval of 3 weeks developed neutralizing and hemagglutination
inhibitory (HAI) antibody titers of 1:40 to 1:160 at 1 week after the second
immunization. However, swine administered two doses of a commercial JE vaccine
(formalin-inactivated virus preparation; JEVAX-A) developed low (1:10) or
undetectable antibody responses after their boost. Interestingly, serum antibody
titers elicited by DNA vaccines in swine were higher than those detected in mice.
Eight days after boosting with viral antigen (JEVAX-A) to detect an anamnestic
response, swine immunized two times with the DNA vaccine showed a >100-fold
elevation in HAI titer, indicating a strong recall of antibody response. Swine
maintained detectable levels of HAI antibody for at least 245 days after two
immunizations with a DNA vaccine. These results indicate that these DNA vaccines
are able to induce virus-specific memory B cells and long-lasting antibodies in
swine, which were of higher levels than those obtained with a commercial formalin
inactivated JE vaccine.
PMID- 10683327
TI - Characterization of an overexpressed spindle protein during a baculovirus
infection.
AB - The nucleopolyhedrovirus CfDEFNPV contains a gene encoding a viral protein, which
accumulates as bipyramidal inclusion bodies (spindles) in the cytoplasm of
infected cells. The spindles appear as early as 24 h postinfection, approximately
1 day earlier than viral occlusion bodies (OBs). Purification and
characterization of the spindle protein was complicated by the fact that the OBs
copurified with the spindles. We therefore modified CfDEFNPV by replacing the
polyhedrin gene (plh) with a cassette containing the green fluorescent protein
(GFP) gene. The recombinant virus did not produce OBs; however, the synthesis and
morphogenesis of the spindles were not altered. When analyzed by SDS-PAGE, the
spindles produced a 50-kDa protein, which was termed spindlin. Tunicamycin
inhibition and endoglycosidase studies showed that spindlin was glycosylated. The
N-terminus of spindlin was sequenced and its gene (gp50) was located on the viral
genome. The gene was cloned and sequenced. Homologs of gp50 were found in several
baculoviruses as well as in entomopoxviruses (EPV). In the latter virus, the
homologous gene is that of fusolin, which also encodes a protein that forms
spindle-shaped inclusion bodies in the cytoplasm of infected cells. Immunoblot
analysis indicated that spindlin and fusolin were not serologically related, even
though they share conserved polypeptide domains. Sequence analysis showed that
gp50 of CfDEFNPV contains two late promoter motifs (TTAAG) in its 5' flanking
region. Both were used, but the proximal motif (-14 to -18 nt relative to the
ATG) was the primary sequence from which most of the mRNA was initiated. When
gp50 was cloned in a heterologous baculovirus expression system, spindlin was
synthesized, although the spindles were irregular in shape. This suggested that
the spindle structure may be species-specific or it may require more than one
gene product for its morphogenesis.
PMID- 10683328
TI - Loss of ATM function enhances recombinant adeno-associated virus transduction and
integration through pathways similar to UV irradiation.
AB - Ataxia telangiectasia is caused by a genetic defect in the ATM gene that results
in altered cellular sensitivity to DNA-damaging agents such as gamma-irradiation.
ATM deficiency is associated with an increased incidence of neurological
disorders, immune deficiency, and cancer. In this report we demonstrate that
recombinant adeno-associated virus (rAAV) gene transfer in ATM-deficient
fibroblasts is significantly enhanced over normal fibroblast cell lines. This
enhancement of rAAV transduction in AT cells is correlated with an increased
abundance of circular form rAAV genomes, as well as a higher number of integrated
head-to-tail concatamer proviral genomes. Studies evaluating AAV trafficking
using Cy3-labeled virus suggest that a nuclear mechanism is responsible for
increased rAAV transduction in AT cells, because binding, endocytosis, and
nuclear trafficking of virus are unaffected by the AT phenotype. Additionally,
the profile of rAAV transduction after UV irradiation is significantly blunted in
AT cells, suggesting that the level of DNA repair enzymes normally associated
with UV augmentation of viral transduction may already be maximally elevated.
These results further expand our understanding of genes involved in rAAV
transduction.
PMID- 10683329
TI - Construction of a selectable nef-defective live-attenuated human immunodeficiency
virus expressing Escherichia coli gpt gene.
AB - We have developed a replication-competent human immunodeficiency virus (HIV)
carrying a selective marker that can be used in vivo. This recombinant virus (Z6
Delta nef gpt) was generated by replacing the 5' half of the HIV nef gene with
the Escherichia coli guanine phosphoribosyl transferase gene (gpt). This new
vector can express the gpt product on infection and works as a positive selective
marker for mycophenolic acid (MPA) resistance, a potent immunosuppressive drug
used in organ rejection therapy. Conversely, gpt expression also served as a
negative selectable marker, since its intracellular expression induces host-cell
susceptibility to 6-thioxantine (6-TX), a nucleotide analog that is toxic to the
infected cell under these conditions. In this manner, we could suppress the
recombinant virus replication through 6-TX selection in both transformed cells
and primary human peripheral blood mononuclear cells (PBMCs), suggesting the
vector's potential as a model for a new live-attenuated vaccine approach against
HIV.
PMID- 10683330
TI - Porcine endogenous retroviruses inhibit human immune cell function: risk for
xenotransplantation?
AB - Transgenic pigs are currently the most favored potential source of organs for
xenotransplantation. Like all mammalian species they all harbor endogenous
retroviruses in their genome. These porcine endogenous retroviruses (PERVs) are
produced from several primary cells and cell lines and are able to infect human
cells. Here we demonstrate that different pig strains and different animals of
one strain differ in their ability to produce PERVs from normal blood cells. We
report that purified PERV particles show a protein pattern typical for type C
retroviruses and are antigenically related to mammalian leukemia viruses. Like
most retroviruses, purified PERVs and peptides derived from the highly conserved
immunosuppressive domain of their transmembrane envelope protein inhibit human
immune cell functions. This indicates that high titer replication of PERVs in the
transplant recipient could therefore lead to an immunodeficiency disease.
PMID- 10683331
TI - The kinetics of specific immune responses in rhesus monkeys inoculated with live
recombinant BCG expressing SIV Gag, Pol, Env, and Nef proteins.
AB - Development of an effective preventive or therapeutic vaccine against HIV-1 is an
important goal in the fight against AIDS. Effective virus clearance and
inhibition of spread to target organs depends principally on the cellular immune
response. Therefore, a vaccine against HIV-1 should elicit virus-specific
cytotoxic lymphocyte (CTL) responses to eliminate the virus during the cell
associated stages of its life cycle. The vaccine should also be capable of
inducing immunity at the mucosal surfaces, the primary route of transmission.
Recombinant Bacille Calmette-Guerin (BCG) expressing viral proteins offers an
excellent candidate vaccine in view of its safety and ability to persist
intracellularly, resulting in the induction of long-lasting immunity and
stimulation of the cellular immune response. BCG can be administered orally to
induce HIV-specific immunity at the mucosal surfaces. The immunogenicity of four
recombinant BCG constructs expressing simian immunodeficiency virus (SIV) Gag,
Pol, Env, and Nef proteins was tested in rhesus macaques. A single simultaneous
inoculation of all four recombinants elicited SIV-specific IgA and IgG antibody,
and cellular immune responses, including CTL and helper T cell proliferation. Our
results demonstrate that BCG recombinant vectors can induce concomitant humoral
and cellular immune responses to the major proteins of SIV.
PMID- 10683332
TI - Deletion mapping of the potyviral helper component-proteinase reveals two regions
involved in RNA binding.
AB - The Potyvirus helper component-proteinase (HC-Pro) binds nonspecifically to
single-stranded nucleic acids with a preference for RNA. To delineate the regions
of the protein responsible for RNA binding, deletions were introduced into the
full-length Potato potyvirus Y HC-Pro gene carried by an Escherichia coli
expression vector. The corresponding proteins were expressed as fusions with the
maltose-binding protein, purified, and assayed for their RNA-binding capacity.
The results obtained by UV cross-linking and Northwestern blot assays
demonstrated that the N- and C-terminal regions of HC-Pro are dispensable for RNA
binding. They also revealed the presence of two independent RNA-binding domains
(designated A and B) located in the central part of HC-Pro. Domain B appears to
contain a ribonucleoprotein (RNP) motif typical of a large family of RNA-binding
proteins involved in several cellular processes. The possibility that domain B
consists of an RNP domain is discussed and suggests that HC-Pro could constitute
the first example of a plant viral protein belonging to the RNP-containing family
of proteins.
PMID- 10683333
TI - Expression of human immunodeficiency virus type 1 Gag protein precursor and
envelope proteins from a vesicular stomatitis virus recombinant: high-level
production of virus-like particles containing HIV envelope.
AB - Recombinant vesicular stomatitis viruses have been developed as high-level
expression vectors which serve as effective vaccine vectors in animals (Roberts
et al., 1998, J. Virol. 72, 4704-4711; Roberts et al., 1999, J. Virol. 73, 3723
3732). Here we show that two genes can be expressed simultaneously from a single,
live-attenuated VSV recombinant. The genes used encode the Pr55(gag) protein
precursor of HIV-1 (1.7-kb gene) and an HIV-1 envelope (Env) protein (2.4 kb
gene). Our results show that VSV can accommodate up to a 40% increase in genome
size with only a threefold reduction in virus titer. Recombinants expressing the
Pr55(gag) protein precursor with or without Env protein produced abundant HIV
virus-like particles (VLPs) in addition to bullet-shaped VSV particles. HIV Env
protein expressed from a VSV recombinant also expressing Gag was specifically
incorporated into the HIV VLPs but not into the VSV particles. In contrast, VSV G
protein was found in both VSV particles and in HIV VLPs. Such VSV/HIV
recombinants producing HIV VLPs with Env protein could be an effective source of
HIV-like particles inducing both cellular and antibody-mediated immunity to HIV
1.
PMID- 10683334
TI - Limitations of in vivo IL-12 supplementation strategies to induce Th1 early life
responses to model viral and bacterial vaccine antigens.
AB - The limited induction of Th1 and cytotoxic immune responses is regarded as the
main reason for the increased susceptibility to intracellular microorganisms in
early life. Recently, in vitro IL-12 supplementation was shown to enhance the
limited IFN-gamma release of measles-specific infant T cells. Using a series of
IL-12 delivery systems, we show here that in vivo IL-12 supplementation may
enhance early life murine Th1 responses to two model vaccine antigens, measles
virus hemagglutinin and tetanus toxin peptide. However, this required multiple
repeat injections of recombinant rIL-12, which were poorly tolerated in young
mice. Local IL-12 delivery by an IL-12 expressing canarypox vector proved safe
but failed to modulate vaccine responses. An IL-12 DNA plasmid or a CD40L DNA
plasmid efficiently enhanced neonatal Th1 responses to measles hemagglutinin DNA
vaccine. However, both plasmids only enhanced Th1 responses to DNA and not to
peptide, protein, or live viral vaccines. Thus, inducing adult-like Th1 responses
may be achieved in vivo by inducing (CD40L) or substituting for (IL-12
supplementation) optimal activation of neonatal APC. However, these
immunomodulatory effects appear limited to certain antigen-presentation
approaches and may not be broadly applicable to vaccines.
PMID- 10683335
TI - Internal cleavage of hepatitis C virus NS3 protein is dependent on the activity
of NS34A protease.
AB - The nonstructural protein NS3 of the hepatitis C virus (HCV) is indispensable for
virus replication and a multifunctional enzyme that contains three catalytic
activities such as serine protease, helicase, and NTPase. Here, we demonstrated
that the internal cleavage of the HCV NS3 protein occurs in various mammalian
cells such as HepG2, COS-7, and NIH3T3. As is observed for the internal cleavage
mechanism of the NS3 protein of dengue virus 2, the internal processing of HCV
NS3 protein was catalyzed by the active NS3 serine protease and NS4A, but not NS3
alone. From the data acquired from extensive site-directed mutagenesis, we
observed that the NS3 protein was internally cleaved at two different sites,
FCH(1395) ||S(1396)KK and IPT(1428) ||S(1429)GD, within RNA helicase domain. The
internal cleavage of NS3 protein by NS34A protease was also confirmed in a
different isolate of HCV-1b strain. In addition, in vitro transforming assays
demonstrated that the internal cleavage product of NS3, NS3a-1, appeared to have
higher oncogenic potential than does intact NS3. Taken together, our results
suggest that the internal cleavage of NS3 may be associated with the replication
and oncogenesis of HCV.
PMID- 10683336
TI - Adenovirus endopeptidase hydrolyses human squamous cell carcinoma antigens in
vitro but not ex vivo.
AB - The serpins SCCA1 and SCCA2 are highly expressed in the epithelium of the
conducting airways, a common site of infection by group C adenoviruses, such as
human adenovirus type 2 (Ad2). Based on the common location we examined a
possible interaction between them. In vitro experiments with recombinant proteins
showed that SCCA1 inhibited the viral protease in a dose-dependent manner. Both
serpins were cleaved in a manner consistent with hydrolysis within their reactive
site loop, without the formation of an SDS-resistant complex, as in the case of
papain. Infection of SCCA1-expressing cells did not result in the cleavage of
SCCA1, nor was the yield of infectious virus affected as compared to SCCA1
negative parental cells. This may be due to differential localization, the serpin
being cytoplasmic and viral protease being nuclear. Surprisingly, however, virus
infection, which tends to inhibit host protein synthesis, caused a significant
increase in SCCA1 expression well into the late phase of infection.
PMID- 10683337
TI - Cellular expression of alphaherpesvirus gD interferes with entry of homologous
and heterologous alphaherpesviruses by blocking access to a shared gD receptor.
AB - Several human and animal alphaherpesviruses can enter cells via human herpesvirus
entry mediator C (HveC), a receptor for viral glycoprotein D (gD). In previous
studies with cells expressing unknown entry mediators, cellular expression of
alphaherpesvirus gD was shown to inhibit entry of the homologous virus and
sometimes also of heterologous alphaherpesviruses. To investigate the mechanism
of gD-mediated interference and the basis for cross-interference among
alphaherpesviruses, HveC was expressed in cells as the sole entry mediator, in
the presence or absence of one of the gDs encoded by herpes simplex virus type 1,
pseudorabies virus, or bovine herpesvirus type 1. Cells expressing HveC alone
were highly susceptible to entry of all three viruses, whereas cells coexpressing
HveC and any one of the gDs were at least partially resistant to infection by
each virus. Coexpression of gD with HveC did not cause reduced levels of cell
surface HveC but the HveC had reduced ability to bind to exogenous gD.
Coimmunoprecipitation experiments revealed that HveC was complexed with gD in
lysates of cells expressing both. Thus, cellular expression of gD can interfere
with alphaherpesvirus entry by blocking ligand-binding sites of the gD
receptor(s) used for entry and cross-interference can occur because different
forms of alphaherpesvirus gD can compete for shared entry receptors.
PMID- 10683338
TI - A role for bovine herpesvirus 1 (BHV-1) glycoprotein E (gE) tyrosine
phosphorylation in replication of BHV-1 wild-type virus but not BHV-1 gE deletion
mutant virus.
AB - Bovine herpesvirus 1 (BHV-1), an alphaherpesvirus, is a major pathogen that
causes respiratory and reproductive infections. We observed tyrosine
phosphorylation of a 95-kDa viral protein and dephosphorylation of 55- and 103
kDa cellular proteins during the course of BHV-1 infection. We demonstrated BHV-1
glycoprotein E (gE) to be the tyrosine phosphorylated viral protein by
immunoprecipitation. Inhibition of phosphorylation of BHV-1 gE by tyrosine kinase
inhibitors genistein and tyrphostin AG1478 substantially lowered the viral titer
in Madin-Darby bovine kidney cells. The decrease in viral titer was directly
proportional to the decrease in phosphorylation of the BHV-1 gE. Interestingly,
these kinase inhibitors did not inhibit the replication of the BHV-1 gE deletion
mutant virion (BHV-1gEDelta3.1). Our findings suggest that the wild-type BHV-1,
with a functional gE protein, uses a different pathway of signaling events than
the BHV-1 gE deletion mutant in replication. Our results indicate that the
tyrosine phosphorylation of the cytoplasmic tail of BHV-1 gE is an important post
translational modification of the functional protein. An application of this
study may be the use of tyrosine kinase inhibitors in controlling the BHV-1
infection.
PMID- 10683339
TI - Distinct transcriptional and functional properties of the R transactivator gene
orf50 of the transforming herpesvirus saimiri strain C488.
AB - The transformation-associated region of herpesvirus saimiri strains is variable,
whereas other parts of the virus genome are highly conserved. However, we
observed considerable interstrain sequence divergence of the early viral
regulatory orf50 gene, which encodes the R transactivator, a homolog of Epstein
Barr virus BRLF1. The orf50 gene of strain C488 was transcribed at low abundance
during lytic infection, whereas antisense transcripts were simultaneously
expressed at high levels. A spliced variant, orf50a, was detectable by RT-PCR and
RNase protection assays in stimulated C488-transformed, nonpermissive human T
cells. In contrast to strain A11, the short, unspliced orf50b form of C488
displayed complete transactivation capability on the orf6 and orf57 promoters. In
summary, there are unexpected structural and functional differences between the
orf50 genes of herpesvirus saimiri strains, which differ in their capability to
transform human T lymphocytes.
PMID- 10683340
TI - The Epstein-Barr virus latent membrane protein 2A PY motif recruits WW domain
containing ubiquitin-protein ligases.
AB - Latent membrane protein 2A (LMP2A) is expressed in latent Epstein-Barr virus
(EBV) infection. LMP2A functions to downregulate B-cell signal transduction and
viral reactivation from latency in EBV-immortalized B cells in vitro, and acts to
provide B cells with both a survival and developmental signal in vivo.
Identification of proteins associated with LMP2A is important for elucidation of
the mechanism that LMP2A employs to regulate B-cell signal transduction and EBV
latency. LMP2A is constitutively tyrosine phosphorylated and is associated with
protein tyrosine kinases such as Lyn and Syk when specific LMP2A tyrosines are
phosphorylated. The amino-terminal domain of LMP2A includes multiple proline-rich
regions, which may provide binding sites for proteins containing SH3 or WW
domains. In this study, we demonstrate that four cellular proteins bind
specifically to two PPPPY (PY) motifs present within the LMP2A amino-terminal
domain. Protein microsequence analysis determined that three of these proteins
were AIP4, WWP2/AIP2, and Nedd4. All of these proteins are members of the Nedd4
like ubiquitin-protein ligases family and have conserved domains including the
C2, WW, and ubiquitin-protein ligase domain. The mutation of both PY motifs
completely abolished binding activity of these proteins to LMP2A and the
interaction of AIP4 and WWP2 with LMP2A was confirmed in cell lines expressing
LMP2A, WWP2, and AIP4. Furthermore, a reduction in the level of Lyn and the rapid
turnover of LMP2A and Lyn were observed in LMP2A-expressing cells. These findings
suggest that LMP2A recruits Nedd4-like ubiquitin-protein ligases and B-cell
signal transduction molecules, resulting in the degradation of LMP2A and Lyn by a
ubiquitin-dependent mechanism. This provides a new means by which LMP2A may
modulate B-cell signal transduction.
PMID- 10683341
TI - Genetic analysis of the cell-to-cell movement of beet yellows closterovirus.
AB - A beet yellows closterovirus (BYV) variant expressing green fluorescent protein
and leaves of BYV local lesion host Claytonia perfoliata were used to reveal
genetic requirements for BYV cell-to-cell movement in leaf epidermis and
mesophyll. A series of mutations targeting genes that are not involved in
amplification of the viral positive-strand RNA was analyzed. The products of
genes coding for a 6-kDa hydrophobic protein (p6) and a 64-kDa protein (p64), as
well as for minor and major capsid proteins, were found to be essential for
intercellular translocation of BYV. In a previous work, we have demonstrated that
the BYV HSP70-homolog (HSP70h) also plays a critical role in viral movement (V.
V. Peremyslov, Y. Hagiwara, and V. V. Dolja, 1999, Proc. Natl. Acad. Sci. USA,
96, 14771-14776). Altogether, a unique protein quintet including three dedicated
movement proteins (p6, p64, and HSP70h) and two structural proteins is required
to potentiate the cell-to-cell movement of a closterovirus. The corresponding BYV
genes are clustered in a block that is conserved among diverse representatives of
the family Closteroviridae.
PMID- 10683342
TI - Dihydrofolate reductase from Kaposi's sarcoma-associated herpesvirus.
AB - Kaposi's sarcoma-associated herpesvirus (KSHV) is the first human virus known to
encode dihydrofolate reductase (DHFR), an enzyme required for nucleotide and
methionine biosynthesis. We have studied the purified KSHV-DHFR enzyme in vitro
and analyzed its expression in cultured B-cell lines derived from primary
effusion lymphoma (PEL), an AIDS-associated malignancy. The amino acid sequence
of KSHV-DHFR is most similar to human DHFR (hDHFR), but the viral enzyme contains
an additional 23 amino acids at the carboxyl-terminus. The viral DHFR,
overexpressed and purified from E. coli, was catalytically active in vitro. The
K(m) of KSHV-DHFR for dihydrofolate (FH(2)) was 2.4 microM, which is
significantly higher than the K(m) of recombinant hDHFR (rhDHFR) for FH(2) (390
nM). K(m) values for NADPH were similar for the two enzymes, about 1 microM. KSHV
DHFR was inhibited by folate antagonists such as methotrexate (K(i): 200 pM),
aminopterin (K(i): 610 pM), pyrimethamine (K(i): 29 nM), trimethoprim (K(i): 2.3
microM), and piritrexim (K(i): 3.9 nM). In all cases, K(i) values for these
folate antagonists were higher for KSHV-DHFR than for rhDHFR. The viral enzyme
was expressed at levels two- to tenfold higher than hDHFR in PEL cell lines as an
early lytic cycle gene. KSHV-DHFR mRNA and protein appeared from 6 to 24 h after
chemical induction of the KSHV lytic cycle. Epitope-tagged KSHV-DHFR and rhDHFR
both localized to the nucleus of transfected cells, while other KSHV nucleotide
metabolism genes localized to the cytoplasm. DHFR activity was not essential for
viral replication in cultured PEL cells. Since hDHFR was not detectable in
peripheral blood mononuclear cells (PBMCs), KSHV-DHFR may function to provide
increased DHFR activity in vivo in infected cells that have little or none of
their own enzyme.
PMID- 10683343
TI - A chloroplastic RNA polymerase resistant to tagetitoxin is involved in
replication of avocado sunblotch viroid.
AB - Avocado sunblotch viroid (ASBVd), the type species of the family Avsunviroidae,
replicates and accumulates in the chloroplast. Two main chloroplastic RNA
polymerases have been described: the plastid-encoded polymerase (PEP) with a
multisubunit structure similar to the Escherichia coli enzyme and a single-unit
nuclear-encoded polymerase (NEP) resembling phage RNA polymerases. On a different
basis, sensitivity to tagetitoxin, two major RNA polymerase activities,
tagetitoxin sensitive (TS) and resistant (TR), have been found in plastids. The
most plausible candidates for the TS and TR RNA polymerases are PEP and NEP,
respectively. To gain an insight into the enzymology of the polymerization of
ASBVd strands, purified chloroplast preparations from ASBVd-infected leaves were
assayed for their in vitro ability to transcribe ASBVd RNAs together with some
representative genes (psbA, 16SrDNA, accD, and rpoB) of the three classes of
chloroplastic genes according to their promoter structure. High concentrations of
alpha-amanitin had no effect on gene or on viroid transcription, but tagetitoxin
(5-10 microM) prevented transcription of all these genes without affecting
synthesis of ASBVd strands; only at higher tagetitoxin concentrations (50-100
microM) was a 25% inhibition observed. These results suggest that NEP is the RNA
polymerase required in ASBVd replication, although the participation of another
TR RNA polymerase from the chloroplast cannot be excluded.
PMID- 10683344
TI - Circulation online only : february 22, 2000
PMID- 10683345
TI - Distinguishing mechanisms from markers of cardiac contractile dysfunction: more
than 1 way to skin the cat of heart failure.
PMID- 10683346
TI - Paraoxonase polymorphism (Gln192Arg) as a determinant of the response of human
coronary arteries to serotonin.
AB - Background-Oxidation of LDL plays a role in endothelial dysfunction. Paraoxonase,
an enzyme present on HDL, protects LDL against oxidation. Paraoxonase activity is
genetically determined in part, and 3 genotypes have been described with variable
enzymatic activity. We hypothesized that the paraoxonase polymorphism might
influence endothelial function. Methods and Results-Twenty-seven patients with
clinical manifestations of coronary artery disease underwent provocative testing
by intracoronary administration of serotonin. None of the coronary arteries
studied had significant (>50%) stenosis. Ten patients had the QQ genotype and 17
had the QR genotype. At proximal segments, the mean percentage reduction in lumen
diameter in response to serotonin was greater in QQ patients than in QR patients
(10(-5) mol/L: P<0.05; 10(-4) mol/L: P<0.006). Similarly, at distal segments,
constriction in response to serotonin was greater in QQ patients than in QR
patients (10(-6) mol/L: P<0. 03; 10(-5) mol/L: P<0.07). Conclusions-These results
suggest a higher synthesis or release of endothelium-derived relaxing factors to
counteract the vasoconstrictor effect of serotonin in patients with the R allele.
These findings provide evidence that the paraoxonase polymorphism may play a role
in the regulation of coronary vasomotor tone.
PMID- 10683347
TI - Hyperfibrinogenemia is associated with specific histocytological composition and
complications of atherosclerotic carotid plaques in patients affected by
transient ischemic attacks.
AB - BACKGROUND: Epidemiological studies have demonstrated that hyperfibrinogenemia is
an independent risk factor for cerebrovascular atherosclerosis. However, the
underlying mechanisms are poorly understood. We studied whether
hyperfibrinogenemia could modify the histological composition of atherosclerotic
plaque and precipitate carotid thrombosis resulting from rupture of the plaque.
METHODS AND RESULTS: We studied the histological composition of 71 carotid
atherosclerotic plaques from patients who had undergone surgical endarterectomy
after a first episode of transient ischemic attack. Patients were divided into 3
groups corresponding to the tertiles of plasma fibrinogen values.
Hypercholesterolemia, hypertriglyceridemia, hypertension, diabetes, and smoking
habit were also assessed. At the histological analysis, plaques of patients in
the highest tertile of fibrinogen (>407 mg/dL) were characterized by a high
incidence of thrombosis (66.7% of cases) compared with plaques of subjects in the
lower (21.7%) (P=0.002) and middle (29. 2%) (P=0.009) tertiles. Plaque rupture
was significantly associated with high fibrinogen levels (54.2%, P=0.003).
Multivariate logistic regression indicated that hyperfibrinogenemia was an
independent risk factor for a decrease in cap thickness (P=0.0005), macrophage
foam cell infiltration of the cap (P=0.003), and thrombosis (P=0. 003). When the
presence of other risk factors was accounted for, hyperfibrinogenemia remained an
independent predictor of carotid thrombosis with an odds ratio of 5.83, compared
with other risk factors. CONCLUSIONS: The results of the present study add to the
evidence that hyperfibrinogenemia, independently of other risk factors, is
associated with a specific histological composition of carotid atherosclerotic
plaques that predisposes them to rupture and thrombosis.
PMID- 10683348
TI - Early percutaneous coronary intervention, platelet inhibition with eptifibatide,
and clinical outcomes in patients with acute coronary syndromes. PURSUIT
Investigators.
AB - BACKGROUND: Platelet glycoprotein (GP) IIb/IIIa antagonists prevent the composite
end point of death or myocardial infarction (MI) in patients with acute coronary
syndromes. There is uncertainty about whether this effect is confined to patients
who have percutaneous coronary interventions (PCIs) and whether PCIs further
prevent death or MI in patients already treated with GP IIb/IIIa antagonists.
METHODS AND RESULTS: PURSUIT patients were treated with the GP IIb/IIIa
antagonist eptifibatide or placebo; PCIs were performed according to physician
practices. In 2253 of 9641 patients (23.4%), PCI was performed by 30 days. Early
(<72 hours) PCI was performed in 1228 (12.7%). In 34 placebo patients (5.5%) and
10 treated with eptifibatide (1.7%) (P=0.001), MI preceded early PCI. In patients
censored for PCI across the 30-day period, there was a significant reduction in
the primary composite end point in eptifibatide patients (P=0.035). Eptifibatide
reduced 30-day events in patients who had early PCI (11.6% versus 16.7%, P=0.01)
and in patients who did not (14.6% versus 15.6%, P=0.23). After adjustment for
PCI propensity, there was no evidence that eptifibatide treatment effect differed
between patients with or without early PCI (P for interaction=0.634). PCI was not
associated with a reduction of the primary composite end point but was associated
with a reduced (nonspecified) composite of death or Q-wave MI. This association
disappeared after adjustment for propensity for early PCI. CONCLUSIONS:
Eptifibatide reduced the composite rates of death or MI in PCI patients and those
managed conservatively.
PMID- 10683350
TI - Assessment of aortic valve stenosis severity: A new index based on the energy
loss concept.
AB - BACKGROUND: Fluid energy loss across stenotic aortic valves is influenced by
factors other than the valve effective orifice area (EOA). We propose a new index
that will provide a more accurate estimate of this energy loss. METHODS AND
RESULTS: An experimental model was designed to measure EOA and energy loss in 2
fixed stenoses and 7 bioprosthetic valves for different flow rates and 2
different aortic sizes (25 and 38 mm). The results showed that the relationship
between EOA and energy loss is influenced by both flow rate and aortic cross
sectional area (A(A)) and that the energy loss is systematically higher (15+/-2%)
in the large aorta. The coefficient (EOAxA(A))/(A(A)-EOA) accurately predicted
the energy loss in all situations (r(2)=0.98). This coefficient is more closely
related to the increase in left ventricular workload than EOA. To account for
varying flow rates, the coefficient was indexed for body surface area in a
retrospective study of 138 patients with moderate or severe aortic stenosis. The
energy loss index measured by Doppler echocardiography was superior to the EOA in
predicting the end points, which were defined as death or aortic valve
replacement. An energy loss index =0.52 cm(2)/m(2) was the best predictor of
adverse outcomes (positive predictive value of 67%). CONCLUSIONS: This new energy
loss index has the potential to reflect the severity of aortic stenosis better
than EOA. Further prospective studies are necessary to establish the relevance of
this index in terms of clinical outcomes.
PMID- 10683349
TI - Effect of mibefradil, a T-type calcium channel blocker, on morbidity and
mortality in moderate to severe congestive heart failure: the MACH-1 study.
Mortality Assessment in Congestive Heart Failure Trial.
AB - BACKGROUND: Calcium antagonists have proved disappointing in long-term congestive
heart failure (CHF) studies. Mibefradil, a new calcium antagonist that
selectively blocks T-type calcium channels, has been shown to be an effective
antihypertensive, antianginal, and anti-ischemic agent, and because of its
different mechanism of action, it may be beneficial as adjunct therapy in CHF
patients. METHODS AND RESULTS: This multicenter, randomized, double-blind study
compared mibefradil with placebo as adjunct to usual therapy in 2590 CHF patients
(NYHA class II to IV; left ventricular fraction <35%). The initial 50-mg daily
dose of mibefradil was uptitrated to 100 mg after 1 month and continued up to 3
years. Patients were monitored at 1 week; 1, 2, and 3 months; and every 3 months
thereafter. All-cause mortality, cardiovascular mortality, and cardiovascular
morbidity/mortality were analyzed by use of the log-rank test (alpha=0.05).
Substudies included exercise tolerance, plasma hormone and cytokines,
echocardiography, and quality of life. Total mortality was similar between
mibefradil- and placebo-treated patients (P=0.151). The 14% increased risk of
mortality with mibefradil in the first 3 months was not statistically significant
(P=0.093). Treatment groups had similar cardiovascular mortality (P=0.246),
cardiovascular morbidity/mortality (P=0.783), and reasons for death or
hospitalization. Patients comedicated with mibefradil and antiarrhythmics (class
I or III), including amiodarone, had a significantly increased risk of death.
Substudies demonstrated no significant differences between treatments.
CONCLUSIONS: When used as adjunct therapy, mibefradil did not affect the usual
outcome of CHF. The potential interaction with antiarrhythmic drugs, especially
amiodarone, and drugs associated with torsade de pointes may have contributed to
poor outcomes early in the study.
PMID- 10683351
TI - Prospective randomized comparison of irrigated-tip versus conventional-tip
catheters for ablation of common flutter.
AB - BACKGROUND: Radiofrequency (RF) ablation of common flutter requires the creation
of a complete ablation line to produce bidirectional conduction block in the
cavotricuspid isthmus. An irrigated-tip ablation catheter has been shown to be
effective in patients in whom conventional ablation has failed. This randomized
study compares the efficacy and safety of this catheter with those of a
conventional catheter for de novo flutter ablation. METHODS AND RESULTS:
Cavotricuspid ablation was performed with a conventional (n=26) or an irrigated
tip catheter (n=24). RF was applied for 60 minutes with a temperature-controlled
mode: 65 degrees C to 70 degrees C up to 70 W with a conventional catheter or 50
degrees C up to 50 W (with a 17-mL/min saline flow rate) with the irrigated-tip
catheter. The end point was the achievement of bidirectional isthmus block, and a
crossover was performed after 21 unsuccessful applications. Procedural ablation
parameters as well as number of applications, x-ray exposure, procedure duration,
impedance rise, and clot formation were compared for each group. A coronary
angiogram was performed before and after each ablation for the first 30 patients.
Complete bidirectional isthmus block was achieved for all patients. Four patients
crossed over from conventional to irrigated-tip catheters. The number of
applications, procedure duration, and x-ray exposure were significantly higher
with the conventional than with the irrigated-tip catheter: 13+/-10 versus 5+/-3
pulses, 53+/-41 versus 27+/-16 minutes, and 18+/-14 versus 9+/-6 minutes,
respectively. No significant side effects occurred, and the coronary angiograms
of the first 30 patients after ablation were unchanged. CONCLUSIONS: Irrigated
tip catheters were found to be more effective than and as safe as conventional
catheters for flutter ablation, facilitating the rapid achievement of
bidirectional isthmus block.
PMID- 10683352
TI - Left ventricular geometry and function preceding neurally mediated syncope.
AB - BACKGROUND: Neurally mediated syncope has been associated with increased left
ventricular (LV) fractional shortening (FS) during tilt testing, which is
consistent with the hypothesis that the stimulation of LV mechanoreceptors leads
to reflex hypotension and/or bradycardia. However, FS does not represent true LV
contractility because of its dependence on afterload and preload. METHODS AND
RESULTS: To elucidate the role of increased contractility in the mediation of
neurally mediated syncope, we compared echocardiographic measures of LV
performance corrected for end-systolic stress (ESS) in 21 patients (13 women and
8 men) with unexplained syncope who had either positive (n=10) or negative (n=11)
responses to a tilt-table test. Two-dimensional echocardiographic LV imaging was
performed at baseline and during the initial 5 minutes of upright tilt. In the
supine position, both groups had similar LV end-diastolic volume indexes, stroke
volumes, FS, circumferential ESS, and afterload-independent measures of LV
performance (stress-corrected midwall and FS). However, after 5 minutes of
upright tilt, patients who subsequently had a positive test had a lower stroke
volume, lower stress-corrected midwall shortening, and endocardial FS. The tilt
positive group also had a greater fall in ESS and FS early during upright tilt.
CONCLUSIONS: Reduced ESS, LV volume, and chamber function during initial upright
tilt are associated with a subsequent positive tilt response in patients with
unexplained syncope. These data suggest that if paradoxic activation of LV
mechanoreceptors has a role in mediating neurally mediated syncope, it is not
triggered by LV hypercontractility or increased systolic wall stress during the
initial period of upright tilt.
PMID- 10683353
TI - Exaggerated renal vasoconstriction during exercise in heart failure patients.
AB - BACKGROUND: During static exercise in normal healthy humans, reflex renal
cortical vasoconstriction occurs. Muscle metaboreceptors contribute importantly
to this reflex renal vasoconstriction. In patients with heart failure, in whom
renal vascular tone is already increased at rest, it is unknown whether there is
further reflex renal vasoconstriction during exercise. METHODS AND RESULTS:
Thirty-nine heart failure patients (NYHA functional class III and IV) and 38 age
matched control subjects (controls) were studied. Renal blood flow was measured
by dynamic positron emission tomography. Graded handgrip exercise and post
handgrip ischemic arrest were used to clarify the reflex mechanisms involved.
During sustained handgrip (30% maximum voluntary contraction), peak renal
vasoconstriction was significantly increased in heart failure patients compared
with controls (70+/-13 versus 42+/-1 U, P=0.02). Renal vasoconstriction returned
to baseline in normal humans by 2 to 5 minutes but remained significantly
increased in heart failure patients at 2 to 5 minutes and had returned to
baseline at 20 minutes. In contrast, during post-handgrip circulatory arrest,
which isolates muscle metaboreceptors, peak renal vasoconstriction was not
greater in heart failure patients than in normal controls. In fact, the increase
in renal vasoconstriction was blunted in heart failure patients compared with
controls (20+/-5 versus 30+/-2 U, P=0.05). CONCLUSIONS: During sustained handgrip
exercise in heart failure, both the magnitude and duration of reflex renal
vasoconstriction are exaggerated in heart failure patients compared with normal
healthy humans. The contribution of the muscle metaboreceptors to reflex renal
vasoconstriction is blunted in heart failure patients compared with normal
controls.
PMID- 10683354
TI - Restoration of diastolic function in senescent rat hearts through adenoviral gene
transfer of sarcoplasmic reticulum Ca(2+)-ATPase.
AB - BACKGROUND: Senescent hearts are characterized by diastolic dysfunction and a
decrease in sarcoplasmic reticulum (SR) Ca(2+)-ATPase protein (SERCA2a). METHODS
AND RESULTS: To test the hypothesis that an increase in SERCA2a could improve
cardiac function in senescent rats (age 26 months), we used a catheter-based
technique of adenoviral gene transfer to achieve global myocardial transduction
of SERCA2a in vivo. Adult rat hearts aged 6 months and senescent rat hearts
infected with an adenovirus containing the reporter gene beta-galactosidase were
used as controls. Two days after infection, parameters of systolic and diastolic
function were measured in open-chest rats. Cardiac SERCA2a protein and ATPase
activity were significantly decreased in senescent hearts compared with adult
rats (Delta -30+/-4% and -49+/-5%) and were restored to adult levels after
infection with Ad.SERCA2a. At baseline, left ventricular systolic pressure and
+dP/dt were unaltered in senescent hearts; however, diastolic parameters were
adversely affected with an increase in the left ventricular time constant of
isovolumic relaxation and diastolic pressure (Delta +29+/-9% and +38+/-12%) and a
decrease in -dP/dt (Delta -26+/-11%). Overexpression of SERCA2a did not
significantly affect left ventricular systolic pressure but did increase +dP/dt
(Delta +28+/-10%) in the senescent heart. Overexpression of SERCA2a restored the
left ventricular time constant of isovolumic relaxation and -dP/dt to adult
levels. Infection of senescent hearts with Ad.SERCA2a markedly improved rate
dependent contractility and diastolic function in senescent hearts. CONCLUSIONS:
These results support the hypothesis that decreased Ca(2+)-ATPase activity
contributes to the functional abnormalities observed in senescent hearts and
demonstrates that Ca(2+) cycling proteins can be targeted in the senescent heart
to improve cardiac function.
PMID- 10683355
TI - Anti-ischemic effect of a novel cardioprotective agent, JTV519, is mediated
through specific activation of delta-isoform of protein kinase C in rat
ventricular myocardium.
AB - BACKGROUND: A new 1,4-benzothiazepine derivative, JTV519, has a strong protective
effect against Ca(2+) overload-induced myocardial injury. We investigated the
effect of JTV519 on ischemia/reperfusion injury in isolated rat hearts. METHODS
AND RESULTS: At 30 minutes of reperfusion after 30-minute global ischemia, the
percent recovery of left ventricular developed pressure was improved, and the
creatine phosphokinase and lactate dehydrogenase leakage was reduced in a
concentration-dependent manner when JTV519 was administered in the coronary
perfusate both at 5 minutes before the induction of ischemia and at the time of
reperfusion. The myocardial protective effect of JTV519 was completely blocked by
pretreatment of the heart with GF109203X, a specific protein kinase C (PKC)
inhibitor. In contrast, the effect of JTV519 was not affected by alpha(1)-, A(1)
, and B(2)-receptor blockers that couple with PKC in the cardiomyocyte. Both
immunofluorescence images and immunoblots of JTV519-treated left ventricular
myocardium and isolated ventricular myocytes demonstrated that this agent induced
concentration-dependent translocation of the delta-isoform but not the other
isoforms of PKC to the plasma membrane. CONCLUSIONS: The mechanism of
cardioprotection by JTV519 against ischemia/reperfusion injury involves isozyme
specific PKC activation through a receptor-independent mechanism. This agent may
provide a novel pharmacological approach for the treatment of patients with acute
coronary diseases via a subcellular mechanism mimicking ischemic preconditioning.
PMID- 10683356
TI - Red wine polyphenols inhibit proliferation of vascular smooth muscle cells and
downregulate expression of cyclin A gene.
AB - BACKGROUND: Red wine polyphenols have been shown to contribute to the "French
paradox" phenomenon, which consists of lower morbidity and mortality from
coronary heart disease in the French population. Although vascular smooth muscle
cell (VSMC) proliferation plays an important role in the progression of
atherosclerotic lesions, the effects of red wine polyphenols on VSMC
proliferation have not been elucidated. METHODS AND RESULTS: We extracted the
total polyphenolic fraction from red wine (RW-PF) by column chromatography.
Treatment with RW-PF showed a potent inhibitory effect on the proliferation and
DNA synthesis of cultured rat aortic smooth muscle cells (RASMCs). In contrast,
the inhibitory effect of RW-PF on the proliferation of bovine carotid endothelial
cells was observed only at much higher concentrations. To elucidate the molecular
mechanisms of this antiproliferative effect of RW-PF on RASMCs, we investigated
the effects of RW-PF on cell cycle regulation. RW-PF downregulated the expression
of cyclin A mRNA and cyclin A promoter activity. In addition, RW-PF decreased the
binding of nuclear proteins to the activating transcription factor (ATF) site in
the cyclin A promoter and downregulated the mRNA levels of transcription factors,
cAMP-responsive element-binding protein (CREB), and ATF-1. CONCLUSIONS: These
results suggest that the downregulation of cyclin A gene expression may
contribute to the antiproliferative effect of red wine polyphenols on RASMCs
through the inhibition of transcription factor expression.
PMID- 10683357
TI - Stent and artery geometry determine intimal thickening independent of arterial
injury.
AB - BACKGROUND: Clinical trials show that larger immediate postdeployment stent
diameters provide greater ultimate luminal size, whereas animal data show that
arterial injury and stent design determine late neointimal thickening. At
deployment, a stent stretches a vessel, imposing a cross-sectional polygonal
luminal shape that depends on the stent design, with each strut serving as a
vertex. We asked whether this design-dependent postdeployment luminal geometry
affects late neointimal thickening independently of the extent of strut-induced
injury. METHODS AND RESULTS: Stainless steel stents of 3 different configurations
were implanted in rabbit iliac arteries for 3 or 28 days. Stents designed with 12
struts per cross section had 50% to 60% less mural thrombus and 2-fold less
neointimal area than identical stents with only 8 struts per cross section.
Sequential histological sectioning of individual stents showed that immediate
postdeployment luminal geometry and subsequent neointimal area varied along the
course of each stent subunit. Mathematical modeling of the shape imposed by the
stent on the artery predicted late neointimal area, based on the re-creation of a
circular vessel lumen within the confines of the initial stent-imposed polygonal
luminal shape. CONCLUSIONS: Immediate postdeployment luminal geometry, dictated
by stent design, determines neointimal thickness independently of arterial injury
and may be useful for predicting patterns of intimal growth for novel stent
designs.
PMID- 10683358
TI - Prevention of high incidence of neurally mediated ventricular arrhythmias by
afferent nerve stimulation in dogs.
AB - BACKGROUND: This study tested the hypothesis that the high incidence of
ventricular arrhythmias caused by hypothalamic stimulation during acute
myocardial ischemia could be attenuated by afferent nerve stimulation and
investigated the cardiac mechanisms for those effects. METHODS AND RESULTS: In 18
anesthetized dogs, stimulating electrodes were implanted in the hypothalamus and
in the isolated left peroneal nerve. The chest was opened and approximately 100
plunge needles were inserted into the ventricles for 3-D activation mapping. Each
animal underwent 4 episodes of 2.5 minutes of acute myocardial ischemia. The
first and fourth episodes served as controls. During the second and third
episodes, animals received either hypothalamic stimulation, peroneal nerve
stimulation, or both. Hypothalamic stimulation significantly increased the
incidence of ventricular arrhythmias. This high incidence was reduced 34% by
simultaneous stimulation of the hypothalamus and peroneal nerve. 3-D mapping
showed a focal origin for all ventricular arrhythmias. Hypothalamic stimulation
increased the number of arrhythmic beats and decreased the coupling interval
between each arrhythmic beat and the preceding beat. These effects were reduced
by peroneal nerve stimulation. CONCLUSIONS: Alteration in autonomic tone by
hypothalamic stimulation causes a high incidence of ventricular arrhythmias
during acute myocardial ischemia that can be decreased by afferent nerve
stimulation.
PMID- 10683359
TI - Images in cardiovascular medicine. Sudden cardiac death in arrhythmogenic right
ventricular dysplasia.
PMID- 10683360
TI - AHA Science Advisory. Resistance exercise in individuals with and without
cardiovascular disease: benefits, rationale, safety, and prescription: An
advisory from the Committee on Exercise, Rehabilitation, and Prevention, Council
on Clinical Cardiology, American Heart Association; Position paper endorsed by
the American College of Sports Medicine.
PMID- 10683361
TI - Peripheral vascular malformation (Servelle-Martorell).
PMID- 10683362
TI - Do clean hands cause allergies?
PMID- 10683363
TI - Inspector General wants to curb administrative costs for managed care
organizations.
PMID- 10683364
TI - Hospitals still losing on Medicare, despite federal relief attempts.
PMID- 10683365
TI - Proposed budget for fiscal year 2001 for Department of Health and Human Services
seeks to expand access to care and boost research funding.
PMID- 10683366
TI - British physician convicted in 15 deaths.
PMID- 10683367
TI - Epigenetic gene silencing in cancer.
PMID- 10683368
TI - Gene silencing as a threat to the success of gene therapy.
PMID- 10683369
TI - The impact of genomic imprinting for neurobehavioral and developmental disorders.
PMID- 10683370
TI - Signaling in leukemia: which messenger to kill?
PMID- 10683371
TI - Fatal myeloproliferation, induced in mice by TEL/PDGFbetaR expression, depends on
PDGFbetaR tyrosines 579/581.
AB - The t(5;12)(q33;p13) translocation associated with chronic myelomonocytic
leukemia (CMML) generates a TEL/PDGFbetaR fusion gene. Here, we used a murine
bone marrow transplant (BMT) assay to test the transforming properties of
TEL/PDGFbetaR in vivo. TEL/PDGFbetaR, introduced into whole bone marrow by
retroviral transduction, caused a rapidly fatal myeloproliferative disease that
closely recapitulated human CMML. TEL/PDGFbetaR transplanted mice developed
leukocytosis with Gr-1(+) granulocytes, splenomegaly, evidence of extramedullary
hematopoiesis, and bone marrow fibrosis, but no lymphoproliferative disease. We
assayed mutant forms of the TEL/PDGFbetaR fusion protein - including 8 tyrosine
to phenylalanine substitutions at phosphorylated PDGFbetaR sites to which various
SH2 domain-containing signaling intermediates bind - for ability to transform
hematopoietic cells. All of the phenylalanine (F-) mutants tested conferred IL-3
independence to a cultured murine hematopoietic cell line, but, in the BMT assay,
different F-mutants displayed distinct transforming properties. In transplanted
animals, tyrosines 579/581 proved critical for the development of
myeloproliferative phenotype. F-mutants with these residues mutated showed no
sign of myeloproliferation but instead developed T-cell lymphomas. In summary,
TEL/PDGFbetaR is necessary and sufficient to induce a myeloproliferative disease
in a murine BMT model, and PDGFbetaR residues Y579/581 are required for this
phenotype.
PMID- 10683372
TI - Mice lacking beta3 integrins are osteosclerotic because of dysfunctional
osteoclasts.
AB - Osteoclasts express the alphavbeta3 integrin, an adhesion receptor that has been
implicated in bone resorption and that is therefore a potential therapeutic
target. To assess the role of this heterodimer in skeletal development in vivo,
we engineered mice in which the gene for the beta3 integrin subunit was deleted.
Bone marrow macrophages derived from these mutants differentiate in vitro into
numerous osteoclasts, thus establishing that alphavbeta3 is not necessary for
osteoclast recruitment. Furthermore, the closely related integrin, alphavbeta5,
does not substitute for alphavbeta3 during cytokine stimulation or authentic
osteoclastogenesis. beta3 knockout mice, but not their heterozygous littermates,
develop histologically and radiographically evident osteosclerosis with age.
Despite their increased bone mass, beta3-null mice contain 3.5-fold more
osteoclasts than do heterozygotes. These mutant osteoclasts are, however,
dysfunctional, as evidenced by their reduced ability to resorb whale dentin in
vitro and the significant hypocalcemia seen in the knockout mice. The resorptive
defect in beta3-deficient osteoclasts may reflect absence of matrix-derived
intracellular signals, since their cytoskeleton is distinctly abnormal and they
fail to spread in vitro, to form actin rings ex vivo, or to form normal ruffled
membranes in vivo. Thus, although it is not required for osteoclastogenesis, the
integrin alphavbeta3 is essential for normal osteoclast function.
PMID- 10683373
TI - Failure of spermatogenesis in mouse lines deficient in the Na(+)-K(+)-2Cl(-)
cotransporter.
AB - The Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) carries 1 molecule of Na(+) and K(+)
along with 2 molecules of Cl(-) across the cell membrane. It is expressed in a
broad spectrum of tissues and has been implicated in cell volume regulation and
in ion transport by secretory epithelial tissue. However, the specific
contribution of NKCC1 to the physiology of the various organ systems is largely
undefined. We have generated mouse lines carrying either of 2 mutant alleles of
the Slc12a2 gene, which encodes this cotransporter: a null allele and a mutation
that results in deletion of 72 amino acids of the cytoplasmic domain. Both NKCC1
deficient mouse lines show behavioral abnormalities characteristic of mice with
inner ear defects. Male NKCC1-deficient mice are infertile because of defective
spermatogenesis, as shown by the absence of spermatozoa in histological sections
of their epididymides and the small number of spermatids in their testes.
Consistent with this observation, we show that Slc12a2 is expressed in Sertoli
cells, pachytene spermatocytes, and round spermatids isolated from wild-type
animals. Our results indicate a critical role for NKCC1-mediated ion transport in
spermatogenesis and suggest that the cytoplasmic domain of NKCC1 is essential in
the normal functioning of this protein.
PMID- 10683374
TI - Enhanced atherosclerosis and kidney dysfunction in eNOS(-/-)Apoe(-/-) mice are
ameliorated by enalapril treatment.
AB - Hypertension and atherosclerosis are each important causes of morbidity and
mortality in the developed world. We have investigated the interaction between
these conditions by breeding mice that are atherosclerotic due to lack of
apolipoprotein (apo) E with mice that are hypertensive due to lack of endothelial
nitric oxide synthase (eNOS). The doubly deficient mice (nnee) have higher blood
pressure (BP) and increased atherosclerotic lesion size but no change in plasma
lipoprotein profiles compared with normotensive but atherosclerotic (NNee) mice.
The nnee mice also develop kidney damage, evidenced by increased plasma
creatinine, decreased kidney weight/body weight ratio, and glomerular lipid
deposition and calcification. Enalapril treatment abolishes the deleterious
effects of eNOS deficiency on BP, atherosclerosis, and kidney dysfunction in nnee
mice. In striking contrast, a genetic lack of inducible NOS, which does not
affect BP, has no effect on the development of atherosclerotic lesions in Apoe(-/
) mice. We also observed a positive relationship between BP and size of
atherosclerotic lesions These results suggest that the atherogenic effects of
eNOS deficiency can be partially explained by an increase in BP and reemphasize
the importance of controlling hypertension in preventing atherosclerosis.
PMID- 10683375
TI - IL-1alpha, IL-1beta, and IFN-gamma mark beta cells for Fas-dependent destruction
by diabetogenic CD4(+) T lymphocytes.
AB - Cytokines such as IL-1alpha, IL-1beta, and IFN-gamma have long been implicated in
the pathogenesis of autoimmune diabetes, but the mechanisms through which they
promote diabetogenesis remain unclear. Here we show that CD4(+) T lymphocytes
propagated from transgenic nonobese diabetic (NOD) mice expressing the highly
diabetogenic, beta cell-specific 4.1-T-cell receptor (4.1-TCR) can kill IL-1alpha
, IL-1beta-, and IFN-gamma-treated beta cells from NOD mice. Untreated NOD beta
cells and cytokine-treated beta cells from Fas-deficient NOD.lpr mice are not
targeted by these T cells. Killing of islet cells in vitro was associated with
cytokine-induced upregulation of Fas on islet cells and was independent of MHC
class II expression. Abrogation of Fas expression in 4.1-TCR-transgenic NOD mice
afforded nearly complete protection from diabetes and did not interfere with the
development of the transgenic CD4(+) T cells or with their ability to cause
insulitis. In contrast, abrogation of perforin expression did not affect beta
cell-specific cytotoxicity or the diabetogenic potential of these T cells. These
data demonstrate a novel mechanism of action of IL-1alpha, IL-1beta, and IFN
gamma in autoimmune diabetes, whereby these cytokines mark beta cells for Fas
dependent lysis by autoreactive CD4(+) T cells.
PMID- 10683376
TI - Impaired mucosal defense to acute colonic injury in mice lacking cyclooxygenase-1
or cyclooxygenase-2.
AB - To investigate roles in intestinal inflammation for the 2 cyclooxygenase (COX)
isoforms, we determined susceptibility to spontaneous and induced acute colitis
in mice lacking either the COX-1 or COX-2 isoform. We treated wild-type, COX-1(-/
), COX-2(-/-), and heterozygous mice with dextran sodium sulfate (DSS) to provoke
acute colonic inflammation, and we quantified tissue damage, prostaglandin (PG)
E(2), and interleukin-1beta. No spontaneous gastrointestinal inflammation was
detected in mice homozygous for either mutation, despite almost undetectable
basal intestinal PGE(2) production in COX-1(-/-) mice. Both COX-1(-/-) and COX-2(
/-) mice showed increased susceptibility to a low-dose of DSS that caused mild
colonic epithelial injury in wild-type mice. COX-2(-/-) mice were more
susceptible than COX-1(-/-) mice, and selective pharmacologic blockade of COX-2
potentiated injury in COX-1(-/-) mice. At a high dose, DSS treatment was fatal to
50% of the animals in each mutant group, but all wild-type mice survived. DSS
treatment increased PGE(2) intestinal secretion in all groups except COX-2(-/-)
mice. These results demonstrate that COX-1 and COX-2 share a crucial role in the
defense of the intestinal mucosa (with inducible COX-2 being perhaps more active
during inflammation) and that neither isoform is essential in maintaining mucosal
homeostasis in the absence of injurious stimuli.
PMID- 10683377
TI - Activation of direct and indirect pathways of glycogen synthesis by hepatic
overexpression of protein targeting to glycogen.
AB - Glycogen-targeting subunits of protein phosphatase-1, such as protein targeting
to glycogen (PTG), direct the phosphatase to the glycogen particle, where it
stimulates glycogenesis. We have investigated the metabolic impact of
overexpressing PTG in liver of normal rats. After administration of PTG cDNA in a
recombinant adenovirus, animals were fasted or allowed to continue feeding for 24
hours. Liver glycogen was nearly completely depleted in fasted control animals,
whereas glycogen levels in fasted or fed PTG-overexpressing animals were 70%
higher than in fed controls. Nevertheless, transgenic animals regulated plasma
glucose, triglycerides, FFAs, ketones, and insulin normally in the fasted and fed
states. Fasted PTG-overexpressing animals receiving an oral bolus of [U
(13)C]glucose exhibited a large increase in hepatic glycogen content and a 70%
increase in incorporation of [(13)C]glucose into glycogen. However, incorporation
of labeled glucose accounted for only a small portion of the glycogen synthesized
in PTG-overexpressing animals, consistent with our earlier finding that PTG
promotes glycogen synthesis from gluconeogenic precursors. We conclude that
hepatic PTG overexpression activates both direct and indirect pathways of
glycogen synthesis. Because of its ability to enhance glucose storage without
affecting other metabolic indicators, the glycogen-targeting subunit may prove
valuable in controlling blood glucose levels in diabetes.
PMID- 10683378
TI - Neointima formation in a restenosis model is suppressed in midkine-deficient
mice.
AB - Neointima formation is a common feature of atherosclerosis and restenosis after
balloon angioplasty. To find a new target to suppress neointima formation, we
investigated the possible role of midkine (MK), a heparin-binding growth factor
with neurotrophic and chemotactic activities, in neointima formation. MK
expression increased during neointima formation caused by intraluminal balloon
injury of the rat carotid artery. Neointima formation in a restenosis model was
strongly suppressed in MK-deficient mice. Continuous administration of MK protein
to MK-deficient mice restored neointima formation. Leukocyte recruitment to the
vascular walls after injury was markedly decreased in MK-deficient mice. Soluble
MK as well as that bound to the substratum induced migration of macrophages in
vitro. These results indicate that MK plays a critical role in neointima
formation at least in part owing to its ability to mediate leukocyte recruitment.
PMID- 10683379
TI - Toll-like receptor 4 imparts ligand-specific recognition of bacterial
lipopolysaccharide.
AB - Lipopolysaccharide (LPS) is the main inducer of shock and death in Gram-negative
sepsis. Recent evidence suggests that LPS-induced signal transduction begins with
CD14-mediated activation of 1 or more Toll-like receptors (TLRs). The lipid A
analogues lipid IVa and Rhodobacter sphaeroides lipid A (RSLA) exhibit an
uncommon species-specific pharmacology. Both compounds inhibit the effects of LPS
in human cells but display LPS-mimetic activity in hamster cells. We transfected
human TLR4 or human TLR2 into hamster fibroblasts to determine if either of these
LPS signal transducers is responsible for the species-specific pharmacology. RSLA
and lipid IVa strongly induced NF-kappaB activity and IL-6 release in Chinese
hamster ovary fibroblasts expressing CD14 (CHO/CD14), but these compounds
antagonized LPS antagonists in CHO/CD14 fibroblasts that overexpressed human
TLR4. No such antagonism occurred in cells overexpressing human TLR2. We cloned
TLR4 from hamster macrophages and found that human THP-1 cells expressing the
hamster TLR4 responded to lipid IVa as an LPS mimetic, as if they were hamster in
origin. Hence, cells heterologously overexpressing TLR4 from different species
acquired a pharmacological phenotype with respect to recognition of lipid A
substructures that corresponded to the species from which the TLR4 transgene
originated. These data suggest that TLR4 is the central lipid A-recognition
protein in the LPS receptor complex.
PMID- 10683380
TI - Dynein light chain binding to a 3'-untranslated sequence mediates parathyroid
hormone mRNA association with microtubules.
AB - The 3'-untranslated region (UTR) of mRNAs binds proteins that determine mRNA
stability and localization. The 3'-UTR of parathyroid hormone (PTH) mRNA
specifically binds cytoplasmic proteins. We screened an expression library for
proteins that bind the PTH mRNA 3'-UTR, and the sequence of 1 clone was identical
to that of the dynein light chain LC8, a component of the dynein complexes that
translocate cytoplasmic components along microtubules. Recombinant LC8 binds PTH
mRNA 3'-UTR, as shown by RNA electrophoretic mobility shift assay. We showed that
PTH mRNA colocalizes with microtubules in the parathyroid gland, as well as with
a purified microtubule preparation from calf brain, and that this association was
mediated by LC8. To our knowledge, this is the first report of a dynein complex
protein binding an mRNA. The dynein complex may be the motor that is responsible
for transporting mRNAs to specific locations in the cytoplasm and for the
consequent is asymmetric distribution of translated proteins in the cell.
PMID- 10683381
TI - Sterol upregulation of human CETP expression in vitro and in transgenic mice by
an LXR element.
AB - The cholesterol ester transfer protein (CETP) facilitates the transfer of HDL
cholesterol esters from plasma to the liver. Transgenic mice expressing human
CETP, controlled by its natural flanking region, increase expression of this gene
in response to hypercholesterolemia. We established a CETP promoter-luciferase
reporter assay in differentiated 3T3-L1 adipocytes to map the sterol upregulatory
element. Promoter mutagenesis suggested that a direct repeat of a nuclear
receptor binding sequence separated by 4 nucleotides (DR4 element, -384 to -399)
was responsible for this activity. Using mice carrying normal or mutated promoter
sequences, we confirmed the importance of this element for gene induction by
dietary sterol. A gel retardation complex containing LXR/RXR was identified using
the CETP DR4 element and adipocyte nuclear extracts. Both LXRalpha/RXRalpha and
LXRbeta/RXRalpha transactivated the CETP promoter via its DR4 element in a sterol
responsive fashion. Thus, the positive sterol response of the CETP gene is
mediated by a nuclear receptor binding site that is activated by LXRs. That
Cyp7a, the rate-limiting enzyme for conversion of cholesterol into bile acids in
the liver, is also regulated by LXRalpha suggests that this class of nuclear
receptor coordinates the regulation of HDL cholesterol ester catabolism and bile
acid synthesis in the liver.
PMID- 10683383
TI - Pretreatment with DNA-damaging agents permits selective killing of checkpoint
deficient cells by microtubule-active drugs.
AB - Cell-cycle checkpoint mechanisms, including the p53- and p21-dependent G(2)
arrest that follows DNA damage, are often lost during tumorigenesis. We have
exploited the ability of DNA-damaging drugs to elicit this checkpoint, and we
show here that such treatment allows microtubule drugs, which cause cell death
secondary to mitotic arrest, to kill checkpoint-deficient tumor cells while
sparing checkpoint-competent cells. Low doses of the DNA-damaging drug
doxorubicin cause predominantly G(2) arrest without killing HCT116 cells that
harbor wt p53. Doxorubicin treatment prevented mitotic arrest, Bcl-2
phosphorylation, and cell death caused by paclitaxel, epothilones, and
vinblastine. In contrast, doxorubicin enhanced cytotoxicity of FR901228, an agent
that does not affect microtubules. Low doses of doxorubicin did not arrest p21
deficient clones of HCT116 cells and did not protect these cells from
cytotoxicity caused by microtubule drugs, but cells in which p21 expression was
restored enjoyed partial protection under these conditions. Moreover, in p53
deficient clones of HCT116 cells doxorubicin did not induce either p53 or p21 and
provided no protection against paclitaxel-induced cytotoxicity. Therefore, (a)
p53-dependent p21 induction caused by doxorubicin protects from microtubule drug
induced cytotoxicity, and (b) pretreatment with cytostatic doses of DNA-damaging
drugs before treatment with microtubule drugs results in selective cytotoxicity
to cancer cells with defective p53/p21-dependent checkpoint.
PMID- 10683384
TI - Development of virus-specific CD4(+) T cells during primary cytomegalovirus
infection.
AB - Although virus-specific CD4(+) T cells have been characterized extensively in
latently infected individuals, it is unclear how these protective T-cell
responses develop during primary virus infection in humans. Here, we analyzed the
kinetics and characteristics of cytomegalovirus-specific (CMV-specific) CD4(+) T
cells in the course of primary CMV infection in kidney transplant recipients. Our
data reveal that, as the first sign of specific immunity, circulating CMV
specific CD4(+) T cells become detectable with a median of 7 days after first
appearance of CMV-DNA in peripheral blood. These cells produce the T helper 1
type (Th1) cytokines IFNgamma and TNFalpha, but not the T helper 2 type (Th2)
cytokine IL4. In primary CMV infection, the vast majority of these circulating
virus-specific T cells have features of recently activated naive T cells in that
they coexpress CD45RA and CD45R0 and appear to be in the cell cycle. In contrast,
in people who have recovered from CMV infection earlier in life, virus-specific T
cells do not cycle and express surface markers characteristic of memory T cells.
After the initial rise, circulating virus-specific CD4(+) T cells decline
rapidly. During this phase, a strong rise in IgM and IgG anti-CMV antibody titers
occurs, concomitant with the reduction of CMV-DNA in the circulation.
PMID- 10683382
TI - The role of the LDL receptor in apolipoprotein B secretion.
AB - Familial hypercholesterolemia is caused by mutations in the LDL receptor gene
(Ldlr). Elevated plasma LDL levels result from slower LDL catabolism and a
paradoxical lipoprotein overproduction. We explored the relationship between the
presence of the LDL receptor and lipoprotein secretion in hepatocytes from both
wild-type and LDL receptor-deficient mice. Ldlr(-/-) hepatocytes secreted apoB100
at a 3.5-fold higher rate than did wild-type hepatocytes. ApoB mRNA abundance,
initial apoB synthetic rate, and abundance of the microsomal triglyceride
transfer protein 97-kDa subunit did not differ between wild-type and Ldlr(-/-)
cells. Pulse-chase analysis and multicompartmental modeling revealed that in wild
type hepatocytes, approximately 55% of newly synthesized apoB100 was degraded.
However, in Ldlr(-/-) cells, less than 20% of apoB was degraded. In wild-type
hepatocytes, approximately equal amounts of LDL receptor-dependent apoB100
degradation occured via reuptake and presecretory mechanisms. Adenovirus-mediated
overexpression of the LDL receptor in Ldlr(-/-) cells resulted in degradation of
approximately 90% of newly synthesized apoB100. These studies show that the LDL
receptor alters the proportion of apoB that escapes co- or post-translational
presecretory degradation and mediates the reuptake of newly secreted apoB
containing lipoprotein particles.
PMID- 10683385
TI - Channel-consistency following unilateral stroke: an examination of patient
communications across verbal and nonverbal domains.
AB - One way in which the dyadic communicative process can go awry is for one or both
parties to send channel-inconsistent communications - communications in which the
verbal and nonverbal elements are not matched in emotional valence (e.g.,
uttering positive words with a frown). We hypothesized that unilateral stroke
patients would be likely to send such messages. Given the verbal impairments
typically associated with left hemisphere damage (LHD), e.g., agrammatism, and
the nonverbal impairments typically associated with right hemisphere damage
(RHD), we expected LHD and RHD patients to send messages in which the impaired
channel was perceived as inconsistent with the unimpaired channel. Ten LHD, 11
RHD and six normal control patients were videotaped while engaging in social
interaction. Observers made judgments about the valence of the patients' (1)
words (based on transcripts of the interactions), and (2) facial expressions
(based on soundless videos of the interactions). Analysis of word-face difference
scores revealed a significant linear trend, with messages of LHD patients judged
more positive in facial expression than in verbal content, messages of RHD
patients judged more positive in verbal content than in facial expression, and
messages of control patients judged channel-consistent (similar in valence across
facial and verbal channels).
PMID- 10683386
TI - A category-specific deficit of spatial representation: the case of
autotopagnosia.
AB - Following a vascular lesion in the parietal cortex of the language dominant
hemisphere (right in one case), two patients showed a striking dissociation
between spared naming, recognition and use of their body parts and an inability
in localising on verbal command the same body parts on themselves and on a
mannequin (Autotopagnosia, AT). The patients were submitted to a modified version
of Reed and Farah Test (1995), a test that taps the ability to encode changes of
body position as opposed to changes of position of objects. Their performance
differed from normal controls, showing a specific deficit in encoding body
position. It is suggested that AT could be the consequence of a lesion in a
specific neural circuit, located in the language dominant hemisphere, whose
function is to encode the body position for both oneself and others.
PMID- 10683387
TI - Converging evidence for the role of occipital regions in orthographic processing:
a case of developmental surface dyslexia.
AB - Recently, there have been several reports focusing on the neural basis for word
recognition. Two different views have emerged: one emphasizing the role of the
left angular gyrus in recognizing printed words, and the second view suggesting
that visual word processing activates the left extrastriate cortex. This paper
describes the case of EBON, a 14-year-old girl with an extensive early (most
likely congenital) brain lesion in the left occipital lobe. She demonstrates a
clear pattern of developmental surface dyslexia in that she is more successful at
reading and spelling regular words than irregular words and makes frequent
regularization errors. Thus, EBON is the first case reported with the potential
to establish converging evidence for the role of extrastriate regions in the left
hemisphere in the acquisition of orthographic representations.
PMID- 10683388
TI - Reversed negative priming following frontal lobe lesions.
AB - The present study investigated whether lesions to the prefrontal cortex would
lead to impaired inhibitory control in selective attention. Patients with uni-
and bilateral frontal lobe damage and age-matched control participants were
compared in an identity negative priming task involving letter naming. Whereas
all control groups revealed robust negative priming and distractor interference,
the majority of patients showed positive instead of negative priming and not all
of them were more susceptible to interference. These results suggest that frontal
lobe lesions disrupt distractor inhibition and cannot be explained in terms of a
retrieval deficit. However, the level of interference may not only be determined
by inhibition but also by excitation of the target stimulus.
PMID- 10683389
TI - Behavioral evidence for brain-based ability factors in visuospatial information
processing.
AB - The present study examined possible parallels between the structure of human
visuospatial abilities and the organization of the neural systems. Forty-eight
participants were tested on seven speeded visuospatial tasks. Three of these
tasks were constructed so as to rely primarily on known ventral stream functions
and four were constructed so as to rely primarily on known dorsal stream
functions. Both sets of tasks spanned approximately the same range of difficulty
as indexed by both the speed and accuracy of decision making. Factor analysis of
response times on the seven tasks revealed only two significant factors. The
putative ventral stream tasks all loaded heavily on one factor (mean
loading=0.843) but only weakly on the other factor (mean loading=0.222); the
putative dorsal stream tasks showed the opposite pattern in that they all loaded
heavily on the second factor (mean loading=0.828) but only weakly on the first
factor (mean loading=0.229). These findings are consistent with the hypothesis
that human visuospatial abilities can be classified using categories based on the
specializations of underlying neural structures and systems.
PMID- 10683390
TI - Wisconsin Card Sorting Test performance in patients with focal frontal and
posterior brain damage: effects of lesion location and test structure on
separable cognitive processes.
AB - Forty-six patients with single focal lesions (35 frontal, 11 nonfrontal) were
administered the Wisconsin Card Sorting Test (WCST) under three conditions of
test administration. The three conditions varied in the amount of external
support provided via specificity of instructions. The WCST, while a
multifactorial test, is specifically sensitive to the effects of frontal lobe
damage if deficits in language comprehension and visual-spatial search are
controlled. There is also specificity of functioning within the frontal lobes:
patients with inferior medial frontal lesions, unilateral or bilateral, were not
impaired on the standard measures although they had increased loss of set when
informed of the sorting categories. Verbal instructions may provide a probe to
improve diagnosis and prognosis, assessment of the potential efficacy of
treatment, and the time frame of plasticity of specific cognitive operations.
PMID- 10683391
TI - The effect of situational factors on hand preferences for feeding in 177 captive
chimpanzees (Pan troglodytes).
AB - This study examined the effect of situational factors on hand use for feeding in
a sample of captive chimpanzees. Lateral bias in hand use was tested in biased
and unbiased testing circumstances to assess strength and consistency in hand
preference. For both unbiased and biased testing conditions, population-level
right hand preferences were found for the sample. In the biased condition,
subjects were more likely to overcome positional factors in order to feed with
their right hand contrasted with the left. Overall, hand use in the biased and
unbiased testing conditions was significantly positively correlated. In terms of
strength of hand use, juveniles were found to be less lateralized than sub-adults
and adults. Moreover, juvenile females were found to be more lateralized than
juvenile males. Taken together, the data suggest that chimpanzee hand preferences
for feeding are not constrained by situational factors and are relatively
consistent in biased and unbiased testing conditions.
PMID- 10683392
TI - A comparison of egocentric and allocentric spatial memory in a patient with
selective hippocampal damage.
AB - The spatial memory of a single patient (YR) was investigated. This patient, who
had relatively selective bilateral hippocampal damage, showed the pattern of
impaired recall but preserved item recognition on standardised memory tests that
has been suggested by Aggleton and Shaw [Aggleton JP, Shaw C. Amnesia and
recognition memory: a reanalysis of psychometric data. Neuropsychologia
1996;34:51-62] to be a consequence of Papez circuit lesions. YR was tested on
three recall tests and one recognition test for visuospatial information. The
initial recall test assessed visuospatial memory over very short unfilled delays
and YR was not significantly impaired. This test was then modified to test recall
of allocentric and egocentric spatial information separately after filled delays
of between 5 and 60 s. YR was found to be more impaired at recalling allocentric
than egocentric information after a 60 s interval with a tendency for the
impairment to increase up to this delay. Recognition of allocentric spatial
information was also assessed after delays of 5 and 60 s. YR was impaired after
the 60 s delay. The results suggest that the human hippocampus has a greater
involvement in allocentric than egocentric spatial memory, and that this most
likely concerns the consolidation of allocentric information into long-term
memory rather than the initial encoding of allocentric spatial information. The
findings also suggest that YR's item recognition/free recall deficit pattern
reflects a problem retrieving or storing certain kinds of associative
information.
PMID- 10683393
TI - Recoding, storage, rehearsal and grouping in verbal short-term memory: an fMRI
study.
AB - Functional magnetic resonance imaging (fMRI) of healthy volunteers is used to
localise the processes involved in verbal short-term memory (VSTM) for sequences
of visual stimuli. Specifically, the brain areas underlying (i) recoding, (ii)
storage, (iii) rehearsal and (iv) temporal grouping are investigated. Successive
subtraction of images obtained from five tasks revealed a network of left
lateralised areas, including posterior temporal regions, supramarginal gyri,
Broca's area and dorsolateral premotor cortex. The results are discussed in
relation to neuropsychological distinctions between recoding and rehearsal,
previous neuroimaging studies of storage and rehearsal, and, in particular, a
recent connectionist model of VSTM that makes explicit assumptions about the
temporal organisation of rehearsal. The functional modules of this model are
tentatively mapped onto the brain in light of the imaging results. Our findings
are consistent with the representation of verbal item information in left
posterior temporal areas and short-term storage of phonological information in
left supramarginal gyrus. They also suggest that left dorsolateral premotor
cortex is involved in the maintenance of temporal order, possibly as the location
of a timing signal used in the rhythmic organisation of rehearsal, whereas
Broca's area supports the articulatory processes required for phonological
recoding of visual stimuli.
PMID- 10683394
TI - Effect of luminance on successiveness discrimination in the absence of the corpus
callosum.
AB - Three split-brained subjects, one with full forebrain commissurotomy and two with
callosotomy, were impaired at judging whether pairs of lights in opposite visual
fields were successive or simultaneous. This impairment did not vary with
luminance when the lights were grey against a dark background, but was more
pronounced when the lights were equiluminant with a yellow background. All three
subjects were also better able to discriminate succession from simultaneity when
the lights were both in the left visual field than when they were both in the
right. A fourth subject with callosal agenesis was only slightly impaired
relative to normal subjects, who were virtually errorless.
PMID- 10683395
TI - Sex differences in brain-behavior relationships between verbal episodic memory
and resting regional cerebral blood flow.
AB - Women have better verbal memory, and higher rates of resting regional cerebral
blood flow (rCBF). This study examined whether there are also sex differences in
the relationship between verbal episodic memory and resting rCBF. Twenty eight
healthy right-handed volunteers (14 male, 14 female) underwent a
neuropsychological evaluation and a Positron Emission Tomography (PET) (15)O
water study. Immediate and delayed recall was measured on the logical memory
subtest of the Wechsler Memory Scale - Revised (WMS-R), and on the California
Verbal Learning Test (CVLT). Resting rCBF (ml/100 g/min) was calculated for four
frontal, four temporal, and four limbic regions of interest (ROIs). Women had
better immediate recall on both WMS-R and CVLT tasks. Sex differences in rCBF
were found for temporal lobe regions. Women had greater bilateral blood flow in a
mid-temporal brain region. There were also sex differences in rCBF correlations
with performance. Women produced positive correlations with rCBF laterality in
the temporal pole. Greater relative CBF in the left temporal pole was associated
with better WMS-R immediate and delayed recall in women only. These results
suggest that trait differences in temporal pole brain-behavior relationships may
relate to sex differences in verbal episodic memory.
PMID- 10683396
TI - Developmental trends in right hemispheric participation in reading.
AB - Behavioral laterality tasks assessed the differential processing efficiencies of
the cerebral hemispheres in younger and older reading-age children. Lateralized
lexical decision task findings supported a "direct access" model of hemispheric
processing for the younger children whereas the older children demonstrated a
"callosal relay" pattern. A dual-task with oral and silent reading indicated that
the right hand was significantly more disrupted than the left during unimanual
finger tapping. The findings suggest that although the left hemisphere's
involvement during reading is developmentally stable, the involvement of the
right hemisphere appears to change dynamically as reading experience increases.
PMID- 10683397
TI - Configurational coding, familiarity and the right hemisphere advantage for face
recognition in sheep.
AB - This study examined characteristics of visual recognition of familiar and
unfamiliar faces in sheep using a 2-way discrimination task. Of particular
interest were effects of lateralisation and the differential use of internal
(configurational) vs external features of the stimuli. Animals were trained in a
Y-maze to identify target faces from pairs, both of which were familiar (same
flock as the subjects) or both of which were unfamiliar (different flock). Having
been trained to identify the rewarded face a series of stimuli were presented to
the sheep, designed to test for the use of each visual hemifield in the
discriminations and the use of internal and external facial cues. The first
experiment showed that there was a left visual hemifield (LVF) advantage in the
identification of 'hemifaces', and 'mirrored hemifaces' and 'chimeric' faces and
that this effect was strongest with familiar faces. This represents the first
evidence for visual field bias outside the primate literature. Results from the
second experiment showed that, whilst both familiar and unfamiliar faces could be
identified by the external features alone, only the familiar faces could be
recognised by the internal features alone. Overall the results suggest separate
recognition methods for socially familiar and unfamiliar faces, with the former
being coded more by internal, configurational cues and showing a lateral bias to
the left visual field.
PMID- 10683398
TI - Acquisition of novel semantic information in amnesia: effects of lesion location.
AB - Two patients with severe global amnesia are described who differ in the extent to
which they have acquired new semantic information. Patient SS, who has extensive
medial temporal lobe damage including the hippocampus as well as surrounding
cortical areas, has failed to acquire virtually any new information regarding
vocabulary or famous faces that entered the public domain since the onset of his
amnesia. In contrast, patient PS, who has a selective lesion of the hippocampus
proper, has gained a sense of familiarity of novel vocabulary and famous people,
even though her effortful retrieval of this new semantic knowledge remains
impaired. These findings extend to amnesia of adult onset, the proposal of Vargha
Khadem and colleagues that in patients with selective hippocampal injury,
cortical areas surrounding the hippocampus may play an important role in new
semantic learning [Vargha-Khadem, F., Gadian, D.G., Watkins, K. E., Connelly, A.,
Van Paesschen, W. and Mishkin, M., regarding the importance of the subhippocampal
cortices in the mediation of new semantic learning in children with hippocampal
lesions, Science, 1997, 277, 376-380].
PMID- 10683399
TI - Asymmetries in cerebral width in nonhuman primate brains as revealed by magnetic
resonance imaging (MRI).
AB - A comparative study of asymmetries in cerebral width was conducted in a sample of
great apes, Old World and New World monkeys. The brains of all subjects were
scanned using magnetic resonance imaging (MRI) and the first axial slice above
the third ventricle was identified. Measures of cerebral width were taken at
distances of 10% and 30% of the length from the occipital and frontal poles.
Cerebral widths were measured from the midline to the lateral surface of the
brain for each area. The great apes exhibited a right-frontal and left-occipital
directional asymmetry in cerebral width. In contrast, no significant mean
directional asymmetries were found in either the Old or New World monkeys. The
results in the great apes are consistent with previous reports of petalia
asymmetries and suggest that the use of MRI is a valid approach to the assessment
of neuroanatomical asymmetries in primates.
PMID- 10683400
TI - Reaching movements may reveal the distorted topography of spatial representations
after neglect.
AB - It has been proposed that patients with spatial neglect fail to respond
appropriately toward stimuli opposite their brain lesion because they have an
impairment of directing attention. However, a disorder of 'intention' - or
movement initiation - has also been demonstrated in this condition. Recently, the
paths of neglect patients' reaches have been shown to be abnormally curved, but
it is unclear whether this impairment is visual or motor. Here, we show for the
first time that reaches to and from identical positions executed by three
patients recovering from neglect are significantly more curved to visually
defined targets compared to when the same targets are defined proprioceptively.
These findings indicate that abnormal hand paths in neglect result from an
impairment in the visual representation of space used to guide reaches but
without any general failure of spatial representation of target position.
Furthermore, the curved hand paths reveal how the topography of that
representation is distorted in spatial neglect.
PMID- 10683401
TI - Differences in visual attention and task interference between males and females
reflect differences in brain laterality.
AB - Two cognitive tasks (a letter memory task and a spatial memory task) designed to
selectively activate the left or right hemisphere were combined with attentional
probe tasks to measure how hemispheric activation affects attention to left and
right hemifields. The probe task in Experiment 1 required the identification of
digits in the left and right hemifield. During the letter task, male subjects
identified more probes from the left hemifield than from the right. Their
accuracy varied little across the two hemifields during the dots task. Experiment
2 tested whether this pattern is due to either spatial attention or interference
in character processing. Instead of identifying digits, the probe task required
subjects to respond to a black square that appeared in the periphery of the
screen. For male subjects, the pattern was opposite of that from Experiment 1.
During the letter task they responded faster to the probe in the right hemifield
than in the left. Their response times were equivalent across the two hemifields
during the dots task.These results indicate two separate effects of laterality in
male subjects. The activation of one hemisphere produced more attention to the
contralateral hemifield in Experiment 2, and the letter memory task interfered
with the processing of other characters in the right visual field more than those
in the left visual field in Experiment 1. Neither of these effects appeared in
female subjects, corroborating earlier claims that female brains are less
lateralized than male brains.
PMID- 10683402
TI - Stimulus modulation of pseudoneglect: influence of line geometry.
AB - A variety of stimulus factors have recently been shown to influence the
performance of normal subjects on line bisection tasks (i.e., pseudoneglect),
independent of motoric factors such as scanning or hand use [McCourt & Jewell
(1999) Neuropsychologia 35, 843-55]. An experiment is described which further
examined the modulating influence of line geometry in determining the magnitude
of pseudoneglect. Subjects bisected horizontally oriented trapezoidal lines
presented in central vision whose narrow end pointed either left or right. A
highly significant influence of line geometry was found which modulated a tonic
leftward error (i.e., pseudoneglect). The results are interpreted in the context
of a "center-of-mass" effect [Shuren, Jacobs & Heilman (1997) Brain and
Cognition, 34, 293-300]. Further studies designed to tease apart the potentially
independent effects of perceptual and attentional asymmetry on bisection
performance are suggested.
PMID- 10683403
TI - An axon pacemaker: diversity in the mechanism of generation and conduction of
action potentials in snail neurons.
AB - One of the main principles in neuroscience is that in vertebrate motoneurons and
certain interneurons the decision to initiate an action potential is made at the
initial segment of the axon, the axon hillock [Kandel E. R. and Schwartz J. H.
(1991) In Principles of Neural Science (eds Kandel E. R., Schwartz J. H. and
Jessell T. M. ), pp. 166-167. Elsevier, New York]. The situation in invertebrate
motoneurons is different. The axon has many arborizations near its soma, in the
nearby neuropil, and many branches in the target region. The action potentials
are generated in the region of the axon in the neuropil and in some cases the
trigger zone can be found more than 1mm apart from the soma [Tauc C. (1962)
Aplysia. J. gen. Physiol. 45, 1077-1097]. Thus, it is obvious that, in a neuron,
the removal of the trigger zone would cease the spiking activity in the axon. The
purpose of this work is to demonstrate that, in snails, there are axons of
certain neurons, like neuron B2, which are able to maintain their firing activity
after the removal of their cell body and the so-called trigger zone.
PMID- 10683404
TI - Search for an IgG response against neural antigens in experimental spinal cord
injury.
AB - In order to determine if a specific response is induced after spinal cord injury,
we performed a kinetic search for IgG antibodies against various spinal cord
antigenic preparations in a rat contusion model. Even though spinal cord injured
animals showed two reactive bands, these could be originated by the reaction of
natural antibodies, since they were also observed before lesion. Thus, these
antibodies would not be of relevance in the pathogenic events of spinal cord
injury in this rat model. Our findings do not demonstrate the existence of a
specific IgG response against spinal cord constituents after injury.
PMID- 10683405
TI - Changes in the distribution and connectivity of interneurons in the epileptic
human dentate gyrus.
AB - The distribution, size, dendritic morphology and synaptic connections of
calbindin-, calretinin- and substance P receptor-positive interneurons and
pathways have been examined in control and epileptic human dentate gyrus. In the
epileptic dentate gyrus, calbindin-containing interneurons are preserved, but
their dendrites become elongated and spiny, and several cell bodies appear
hypertrophic. The relative laminar distribution of calretinin-containing cells
did not change, but their number was considerably reduced. The calretinin
positive axonal bundle at the top of the granule cell layer originating from the
supramammillary nucleus expanded, forming a dense network in the entire width of
the stratum moleculare. Substance P receptor-immunopositive cells were partially
lost in epileptic samples, and in addition, the laminar distribution and
dendritic morphology of the surviving cells differed considerably from the
controls. In the control human dentate gyrus, the majority of substance P
receptor-positive cells can be seen in the hilus, while most are present in the
stratum moleculare in the epileptic tissue. Their synaptic input is also changed.
The extent of individual pathological abnormalities correlates with each other in
most cases. Our data suggest, that although a large proportion of inhibitory
interneurons are preserved in the epileptic human dentate gyrus, their
distribution, morphology and synaptic connections differ from controls. These
functional alterations of inhibitory circuits in the dentate gyrus are likely to
be compensatory changes with a role to balance the enhanced excitatory input in
the region.
PMID- 10683406
TI - Evidence for the existence of non-GABAergic, cholinergic interneurons in the
rodent hippocampus.
AB - Previous studies have revealed a small number of hippocampal interneurons
immunoreactive for choline acetyltransferase, the acetylcholine-synthesizing
enzyme. It remained an open question, however, whether these neurons represented
a subgroup of inhibitory GABAergic neurons co-localizing acetylcholine. In this
study, we have combined immunocytochemistry for choline acetyltransferase and in
situ hybridization for glutamate decarboxylase messenger RNA, the GABA
synthesizing enzyme. None of the choline acetyltransferase-immunoreactive neurons
in the various layers of the hippocampus proper and fascia dentata were found to
co-localize glutamate decarboxylase messenger RNA. The lack of an in situ
hybridization signal in these neurons is unlikely to result from the combination
of the two labeling techniques. When combining in situ hybridization for
glutamate decarboxylase messenger RNA with immunostaining for parvalbumin, a
calcium-binding protein expressed by many GABAergic hippocampal interneurons,
numerous double-labeled cells were observed. These data provide neurochemical
evidence for the existence of non-GABAergic, supposedly cholinergic non-principal
cells in the hippocampus.
PMID- 10683407
TI - Strychnine-sensitive glycine receptors in rat caudatoputamen are expressed by
cholinergic interneurons.
AB - Strychnine-sensitive glycine receptors are ligand-gated anion channels widely
expressed in spinal cord and brainstem. Recent functional studies demonstrating
glycine-induced release of [(3)H]acetylcholine in rat caudatoputamen suggested
the existence of excitatory glycine receptors in that region. Since the
expression of glycine receptors in the caudatoputamen had not been reported
earlier, we studied the glycine receptor-like immunoreactivity in this structure
using a monoclonal antibody (mAb4a) recognizing an epitope common to all of the
ligand-binding alpha-subunit variants of the glycine receptor. [Becker et al.
(1993) Brain Res. 11, 327-333; Nicola et al. (1992) Neurosci. Lett. 138, 173
178]. Immunohistochemistry with mAb4a disclosed a specific staining of sparsely
distributed large neurons in rat caudatoputamen, displaying an immunoreactive
signal of lower intensity than that observed in motoneurons in spinal cord.
Fluorescent dual labelling demonstrated that glycine receptor-like
immunoreactivity co-localizes with choline acetyltransferase-like
immunoreactivity in rat caudatoputamen. All neurons with glycine receptor-like
immunoreactivity in the caudatoputamen studied were immunoreactive with choline
acetyltransferase, and represented a subpopulation of cholinergic neurons
(approximately 90% of the somata with choline acetyltransferase-like
immunoreactivity). These results suggest that strychnine-sensitive glycine
receptors are present on cholinergic interneurons in rat caudatoputamen,
supporting the hypothesis that glycine receptors inducing striatal release of
[(3)H]acetylcholine may be localized to cholinergic neurons.
PMID- 10683408
TI - Estrogen binding and estrogen receptor characterization (ERalpha and ERbeta) in
the cholinergic neurons of the rat basal forebrain.
AB - Estrogen is thought to enhance cognitive functions by modulating the production
of acetylcholine in basal forebrain neurons; a system that projects to the
cerebral cortex and hippocampus and plays a central role in learning and memory.
To elucidate the mechanism of estrogen action in the cholinergic system, we
utilized a combined in vivo autoradiography/immunocytochemistry technique to
evaluate the distribution of estrogen binding sites in cholinergic neurons of the
rat basal forebrain. The results of these studies revealed that a portion of the
cholinergic neurons in the medial septum (41%), vertical (32%) and horizontal
(29%) limbs of the diagonal band and in the substantia innominata/nucleus basalis
(4%) contained estrogen receptors. Through the use of a double-label in situ
hybridization/immunocytochemistry technique we have shown that estrogen receptor
alpha is the predominant estrogen receptor in the cholinergic neurons, with only
a few cells containing estrogen receptor-beta. The results of these studies
provide evidence that biologically active estrogen receptors are present in the
basal forebrain cholinergic neurons of the adult rat brain, with estrogen
receptor-alpha being the predominant receptor subtype. The demonstration that
cholinergic neurons contain estrogen receptors is consistent with the possibility
that estrogen directly modulates the activity of cholinergic neurons in rats and
may provide insight as to how estrogen improves cognitive functions in women.
PMID- 10683409
TI - Acute immediate-early gene response to 6-hydroxydopamine infusions into the
medial forebrain bundle.
AB - Although the long-term neurobiological and behavioral effects of nigrostriatal
lesions are well characterized, the events occurring soon after injury are not.
These acute events can provide insight into the mechanisms underlying long-term
adaptations to nigrostriatal lesions. The present experiments examined the basal
ganglia immediate-early gene response to infusions of the catecholamine
neurotoxin 6-hydroxydopamine into the nigrostriatal pathway in rats. Following 6
hydroxydopamine infusions into the medial forebrain bundle in awake, behaving
rats, there was a rapid and transient induction of striatal c-fos and zif/268
messenger RNAs. Both immediate-early genes were maximally induced by 45min post
infusion, and returned to control levels by 1.5h (c-fos) or 3h (zif/268) post
infusion. Double-labeling experiments revealed that striatal c-fos expression
occurred preferentially in preproenkephalin-expressing neurons. 6-Hydroxydopamine
induced c-fos messenger RNA was also observed in the substantia nigra pars
reticulata and entopeduncular nucleus, but not the globus pallidus, 45 min after
medial forebrain bundle 6-hydroxydopamine infusions. Finally, the role of
ionotropic striatal glutamate receptors in nigrostriatal injury-induced striatal
c-fos was examined by combining medial forebrain bundle 6-hydroxydopamine
infusions with intrastriatal glutamate antagonist infusions. Both the N-methyl-D
aspartate antagonist, (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid,
and the non-N-methyl-D-aspartate antagonist, 6,7-dinitroquinoxaline-2, 3-dione,
blocked striatal induction of c-fos messenger RNA following 6-hydroxydopamine
infusions into the medial forebrain bundle. These results provide evidence of
rapidly developing, glutamate-dependent molecular responses in the basal ganglia
which may contribute to some of the well-described long-term adaptations of this
system to nigrostriatal injury.
PMID- 10683410
TI - Neurochemical changes induced by acute and chronic administration of 1,2,3,4
tetrahydroisoquinoline and salsolinol in dopaminergic structures of rat brain.
AB - The finding that endogenous tetrahydroisoquinolines may be involved in the
etiology of Parkinson's disease suggests that their administration may cause
changes resembling those observed in parkinsonian brain. We tested, using a high
performance liquid chromatography method, how single and chronic administration
of 1,2, 3,4-tetrahydroisoquinoline and salsolinol affects dopamine and serotonin
metabolism in the neurons of extrapyramidal and mesolimbic dopaminergic systems.
We report that chronic administration of tetrahydroisoquinoline and salsolinol
causes a decrease in a dopamine metabolism: the effect of tetrahydroisoquinoline
was limited to the striatum, while salsolinol caused also a dramatic decline of
dopamine level in the substantia nigra. The effect of both compounds on serotonin
metabolism was small or absent. The tetrahydroisoquinolines produced no changes
in the nucleus accumbens. The results indicate that tetrahydroisoquinoline and
salsolinol specifically affect the nigrostriatal dopamine system, but only when
administered chronically, and thus are compatible with the view that endogenous
tetrahydroisoquinolines may participate in pathogenesis of Parkinson's disease.
PMID- 10683411
TI - Inhibitory glutamatergic regulation of evoked dopamine release in striatum.
AB - Certain aspects of schizophrenia and Parkinson's disease suggest that glutamate
might have an inhibitory effect on dopamine release. Several studies have
reported that the excitatory actions of ionotropic glutamate agonists on
extracellular dopamine levels in striatum are resistant to tetrodotoxin, which
suggests that glutamate excites an impulse-independent mechanism of dopamine
release. We tested the hypothesis that an inhibitory action of glutamate on
dopamine terminals in the striatum specifically involves an impulse-dependent
mechanism of dopamine release. We used voltammetry to monitor electrically-evoked
dopamine release in striatal slices, which is completely tetrodotoxin- and Ca(2+)
sensitive and so provides a model of impulse-dependent dopamine release. Agonists
of the ionotropic glutamate receptors significantly decreased the amplitude of
the response, while antagonists significantly increased the amplitude of the
response, by as much as approximately 60% in the case of kynurenic acid. These
results support the hypothesis that ionotropic glutamate receptors can inhibit
impulse-dependent dopamine release by a mechanism that acts locally within the
striatum. This finding contrasts with previous reports that glutamate can excite
impulse-independent dopamine release. This extends earlier findings that
glutamate may both excite and inhibit subcortical dopamine systems by suggesting
that the excitatory and inhibitory actions of striatal ionotropic glutamate
receptors are specifically associated with impulse-independent and impulse
dependent dopamine release, respectively.
PMID- 10683412
TI - Specificity of amygdalostriatal interactions in the involvement of mesencephalic
dopaminergic neurons in affective perception.
AB - We have recently shown that dopaminergic responses to an attractive or an
aversive stimulus were respectively increased and decreased in the core part of
the nucleus accumbens and the ventromedial dorsal striatum. By contrast,
increases in dopaminergic responses were obtained in the shell part of the
nucleus accumbens with stimuli of both affective values. In addition, the
involvement of the basolateral amygdala in affective processes has been reported
by several authors. Anatomo-functional relationships between the basolateral
amygdala and striatal structures have also been described. Thus, in the present
work we studied the regulation by the basolateral amygdala of affective
dopaminergic responses in the two parts of the nucleus accumbens (core and shell)
and the ventromedial dorsal striatum. More precisely, variations in extracellular
levels of dopamine induced by an attractive or an aversive olfactory stimulus
were studied using in vivo voltammetry in freely moving rats. Changes in dopamine
levels in the three left striatal regions were measured after functional blockade
of the ipsilateral basolateral amygdala with tetrodotoxin. Changes in place
attraction or aversion toward the stimulus were studied in parallel to dopamine
variations. The results obtained suggest a specific regulation of affective
dopaminergic responses in the two parts of the nucleus accumbens by the
basolateral amygdala and a lack of influence of the basolateral amygdala on the
ventromedial dorsal striatum. The results suggest that attraction or aversion
toward a stimulus are correlated with dopamine variations in the core of the
nucleus accumbens and that the basolateral amygdala controls affective
behavioural responses. These data may provide new insights into the
pathophysiology of schizophrenic psychoses.
PMID- 10683413
TI - Differential regional zif268 messenger RNA expression in an escalating dose/binge
model of amphetamine-induced psychosis.
AB - Amphetamine-induced psychosis is most often associated with a high-dose multiple
binge pattern of stimulant abuse. To simulate these conditions in rats, we used
an escalating dose/binge administration paradigm. Animals were pretreated with
escalating doses of amphetamine (1.0-8.0mg/kg) over four days, then exposed to
nine daily binges (8.0mg/kg every 2h; four injections/day). Other animals
received either multiple injections of saline, saline followed by acute
amphetamine (8.0mg/kg) or single daily injections of amphetamine (8.0mg/kg) in
parallel with the escalating dose/binge treatment. One hour after the last
injection, all animals were decapitated and regional brain activation patterns
were assessed using in situ hybridization with antisense probes for zif268. Acute
amphetamine resulted in a significant elevation of zif268 messenger RNA in both
the nucleus accumbens and dorsal striatum. However, whereas after single daily
amphetamine treatment this index was no longer elevated above control levels in
the dorsal striatum, multiple binge exposures were required for the nucleus
accumbens to return to baseline. Agranular insular cortex and medial olfactory
tubercle zif268 messenger RNA expression was also markedly increased after acute
amphetamine treatment but, unlike the nucleus accumbens and dorsal striatum, this
increase was not significantly attenuated by either single daily injection or
multiple binge treatment. Zif268 messenger RNA expression in the lateral nucleus
of the amygdala also remained elevated above baseline after binge treatment. The
possible relationships of these changes in zif268 messenger RNA regional
expression patterns to the development of psychosis in high-dose stimulant
abusers are discussed.
PMID- 10683414
TI - Kappa opioid receptor immunoreactivity in the nucleus accumbens and caudate
putamen is primarily associated with synaptic vesicles in axons.
AB - A rabbit polyclonal antiserum, raised against a C-terminal oligopeptide of the
mouse kappa opioid receptor, was used to localize the cellular distribution of
kappa receptors in the dorsal and ventral striatum of rats with light and
electron microscopic immunocytochemistry. Prominent, diffuse kappa receptor
immunoreactivity was present in the nucleus accumbens, particularly in the shell,
ventral caudate-putamen and olfactory tubercle. The density of receptor
immunoreactivity decreased in more dorsal areas of the caudate-putamen. In
contrast, neuronal cell bodies stained clearly in the dorsal endopiriform
nucleus, claustrum and layer VI of the adjacent cerebral cortex. Observations at
the electron microscopic level in the dorsomedial shell of the nucleus accumbens
and caudate-putamen revealed that the kappa receptor immunoreactivity was
predominantly located in axons, often associated with synaptic vesicles, remote
from the terminal or preterminal area. The few terminals which were labeled made
slightly more asymmetrical than symmetrical contacts and the percentage of
asymmetrical contacts observed was greater in the caudate than in the accumbens.
A small number of postsynaptic spines was labeled; most of them were contacted by
asymmetrical terminals. No labeling was observed in dendritic shafts.Thus, the
predominant localization of kappa receptor immunoreactivity in axons is
consistent with its role as a major inhibitor of glutamate and dopamine release
in the dorsal and ventral striatum.
PMID- 10683415
TI - Effect of unilateral deafferentation on extracellular potassium concentration
levels in rat thalamic nuclei.
AB - The autotomy performed by rats after unilateral section of the dorsal roots
corresponding to the brachial plexus was frequently attributed to an abnormal
painful sensation felt in the peripheral deafferented area. We studied the values
of potassium (K(+)) extracellular concentration ([K(+)](e)) in thalamic nuclei of
somatic projection in this animal model of deafferentation pain. Potassium
concentrations were measured with microelectrodes sensitive to K(+) (K(+)-ISM).
When such microelectrodes are gradually inserted into the thalamus, a sudden
transient increase of K(+) concentration appears after each step lasting for
about 30s. This is followed by a stabilization of K(+) values, which is present
for several hours. We measured this stable concentration of K(+) (resting
[K(+)](e)) for 3-5 min in different nuclei of the somatic projection to the
lateral thalamus of controls and deafferented groups of adult rats under
Equithesin anaesthesia. The following thalamic nuclei were explored: the ventral
posterior medial and lateral (VPM and VPL) and the adjacent posterior oral (PO)
as well as the lateral dorsal (LD) and posterior (LP) and ventral anterolateral
(VAL). In the control group (12 rats), the mean values of resting [K(+)](e)
expressed in mmol/l in these nuclei were between 3.26 and 3.62. All these values
of the K(+) concentration were significantly higher than those in the
cerebrospinal fluid for P<0.001. In the deafferented group (21 rats), a
significant increase of the resting [K(+)](e) concentration was found in three
nuclei only (VPL, VPM, PO) of the thalamus contralateral to the root section,
when compared to the corresponding nuclei in the controls. No changes were
observed in the other contralateral nuclei and in all nuclei of the thalamus
ipsilateral to the deafferentation. The most statistically significant changes in
mean values were found in five deafferented animals, which had recently performed
autotomy. Localised variations of resting [K(+)](e) observed in each of VPL, VPM
and PO nuclei were also demonstrated by curves traced for each control and
deafferented animal. The greatest changes in resting [K(+)](e) were observed in
the three nuclei mentioned above, where the value of [K(+)](e) attained 6 to 7
mmol/l in deafferented animals. The maximum amplitude peaks of resting [K(+)](e)
were found in animals which had recently exhibited autotomy. These enhanced
resting values of [K(+)](e) apparently reflect increased activity in the somatic
lateral thalamus of deafferented animals. Their possible role in pain and
autotomy are discussed.
PMID- 10683416
TI - Projection neurons in the superficial layers of the superior colliculus in the
rat: a topographic and quantitative morphometric analysis.
AB - The present study deals with qualitative and quantitative investigations in the
superior colliculus of the rat. Tracer studies were correlated with Nissl
staining to calculate the quantitative ratio between projection neurons and
interneurons in the upper three layers of the superior colliculus. In order to
reveal the projections from the superior colliculus, the first group of rats
received injections of the tracer FluoroGold into the nucleus lateralis posterior
thalami, the lateral geniculate body, the nucleus parabigeminalis, and the
predorsal bundle. Commissural connections between the superior colliculus were
traced in a second group of animals, which received Biocytin and FluoroGold
injections in the upper layers of the right superior colliculus and small
deposits of the carbocyanine tracer DiI in the deeper layers of the left superior
colliculus. Additionally, double-labelling with FluoroGold tracing and the
histochemical detection of NADPH-diaphorase activity was carried out to
distinguish between projection neurons and interneurons. These experiments showed
that 66% of the neurons within the superficial layers of the superior colliculus
were represented by ascending projection neurons, whereas only 2-3% could be
identified as descending neurons. Ascending neurons were scattered throughout the
three laminae and descending neurons were localized in a cluster-like pattern.
Approximately 2-3% of the neurons in the superficial layers were found to be
commissural and interlayer neurons which were represented by an identical cell
type, since both transcommissural and interlayer processes were originated from
their somata. The somata of these commissural-interlayer neurons were all located
in the mediorostral part of the superior colliculus and contained NADPH
diaphorase activity. The axon terminals of the interlayer-commissural neurons
formed net-like structures which surrounded neuronal somata within the
ipsilateral deep layers and within the contralateral upper layers of the superior
colliculus, respectively.
PMID- 10683417
TI - The neuronal EF-hand calcium-binding protein visinin-like protein-3 is expressed
in cerebellar Purkinje cells and shows a calcium-dependent membrane association.
AB - Visinin-like protein-3 is a member of the family of intracellular neuronal
calcium sensors belonging to the superfamily of EF-hand proteins. Members of this
family are involved in the calcium-dependent regulation of signal transduction
cascades. To gain insights into the characteristics of visinin-like protein-3, we
have generated specific antibodies against visinin-like protein-3 and determined
the developmental and tissue distribution of the protein and its exact cellular
and subcellular localization. Expression of visinin-like protein-3 protein
appeared late in development mainly in the cerebellum. It is strongly expressed
in cerebellar Purkinje cells. The protein expression results were further
confirmed by in situ hybridization and compared with hippocalcin messenger RNA
localization. Native cerebellar visinin-like protein-3 was shown to bind calcium
and to associate in a calcium-dependent manner with membrane fractions during
subcellular fractionation. Recombinant wild-type visinin-like protein-3 was shown
to be N-terminally myristoylated in transfected cells. The membrane association
was strongly reduced for the non-myristoylated mutant of visinin-like protein-3
in transfected cells. These results suggest that visinin-like protein-3, which is
mainly expressed in Purkinje cells in vivo, shows a calcium-dependent association
with cell membranes which is mediated by a calcium-myristoyl switch.
PMID- 10683418
TI - Traumatic injury induces differential expression of cell death genes in
organotypic brain slice cultures determined by complementary DNA array
hybridization.
AB - The expression of a large panel of selected genes hypothesized to play a central
role in post-traumatic cell death was shown to be differentially altered in
response to a precisely controlled, mechanical injury applied to an organotypic
slice culture of the rat brain. Within 48 h of injury, the expression of nerve
growth factor messenger RNA was significantly increased whereas the levels of bcl
2, alpha-subunit of calcium/calmodulin-dependent protein kinase II, cAMP response
element binding protein, 65,000 mol. wt isoform of glutamate decarboxylase, 1beta
isoform of protein kinase C, and ubiquitin messenger RNA were significantly
decreased. Because the expression levels of a number of other messenger RNAs such
as the neuron-specific amyloid precursor protein, beta(2) microglobulin, bax,
bcl(xl), brain-derived neurotrophic factor, cyclooxygenase-2, interleukin-1beta,
interleukin-6, tumor necrosis factor-alpha, receptor tyrosine kinase A, and
receptor tyrosine kinase B were unaffected, these selective changes may represent
components of an active and directed response of the brain initiated by
mechanical trauma. Interpretation of these co-ordinated alterations suggests that
mechanical injury to the central nervous system may lead to disruption of calcium
homeostasis resulting in altered gene expression, an impairment of intracellular
cascades responsible for trophic factor signaling, and initiation of apoptosis
via multiple pathways. An understanding of these transcriptional changes may
contribute to the development of novel therapeutic strategies to enhance
beneficial and blunt detrimental, endogenous, post-injury response mechanisms.
PMID- 10683419
TI - Extended neuronal protection induced after sublethal ischemia adjacent to the
area with delayed neuronal death.
AB - In the present study, we investigated whether neurons adjacent to an ischemic
lesion acquire tolerance against subsequent ischemia or not. We initially used
unilateral hemispheric ischemia for 3 min in gerbils to produce an ischemic
lesion confined to the unilateral CA1 sector, and the presence of tolerance was
examined in the adjacent CA3 sector through transient global ischemia by
occlusion of both common carotid arteries. Attenuation of neuronal damage was
clearly observed in neurons in the CA3 sector adjacent to the ischemic lesion in
the CA1 sector. The phenomenon lasted for up to two weeks after the initial
hemispheric ischemia, but was no longer present two months later. Reactive
astrocytes as identified by the presence of glial fibrillary acidic protein were
visible in the CA3 hippocampus four days and two weeks after hemispheric
ischemia, but they were scarce two months later. Expression of heat shock protein
72 in the CA3 neurons was observed four days after hemispheric ischemia, but the
reaction returned to the control level two weeks later. In conclusion, the
present study showed that tolerance in the neurons adjacent to an ischemic lesion
could be sustained at least for two weeks, and raised the possibility that
reactive astrocytes might contribute to the extended tolerance in neurons.
PMID- 10683420
TI - Increased expression of apoptosis-linked gene 2 (ALG2) in the rat brain after
temporary focal cerebral ischemia.
AB - Calcium is an important mediator of programmed cell death induced by transient
cerebral ischemia, and calcium-binding proteins have been implicated in calcium
regulated signal transduction. Apoptosis-linked gene 2 is a calcium-binding
protein required for cell death induced by different apoptotic stimuli. By
Western blot analysis, we found that apoptosis-linked gene 2 protein was
expressed in normal brains, and that expression increased in ischemic brains
after 20 or 90 min of transient focal cerebral ischemia. Immunocytochemistry
showed increased apoptosis-linked gene 2 protein expression in frontal cortex, a
region where neurons underwent ischemic stress but still survived, after 20 or 90
min of focal cerebral ischemia. Apoptosis-linked gene 2 protein was also up
regulated in the ischemic border-zone of parietal cortex 24h after 20 min of
focal ischemia, and was remarkably over-expressed in the caudate-putamen and
parietal cortex, (where cells are destined to die) 24h after 90 min of ischemia.
The expression pattern of apoptosis-linked gene 2 protein was similar to that of
deoxyribonucleic acid damage detected by Klenow labeling assay. Our results
suggest that apoptosis-linked gene 2 may be involved in the regulation of cell
death after transient focal cerebral ischemia.
PMID- 10683421
TI - Autoradiography of receptor-activated G-proteins in post mortem human brain.
AB - The agonist-stimulated guanosine 5'-(gamma-[(35)S]thio)triphosphate binding assay
was used to anatomically localize receptor-activated G-proteins by
autoradiography in post mortem human brain. The optimal conditions for guanosine
5'-(gamma-[(35)S]thio)triphosphate binding to human brain sections were
established in post mortem samples of the prefrontal cortex, hippocampus, basal
ganglia, brainstem and cerebellar cortex. An excess of GDP (2mM) was required to
decrease basal activity and obtain effective stimulation by specific agonists.
guanosine 5'-(gamma-[(35)S]Thio)triphosphate binding was increased after
stimulation with specific agonists of different G-protein-coupled receptors. They
include cannabinoid (WIN55212-2), mu-opioid ([D-Ala(2),N-Me-Phe(4), Gly(5)
ol]enkephalin), serotonin-1A [(+/-)-8-hydroxy-2-(di-n-propylamino)tetralin] and
serotonin-1B/1D (sumatriptan), cholinergic muscarinic receptors (carbachol) and
alpha(2)-adrenoceptors (UK14304). Such stimulation reached 1458%, 440%, 188%,
219%, 61% and 339%, respectively, over the basal levels. In tissue sections, the
use of the above-mentioned agonists (10(-4)M) showed patterns of anatomical
distribution similar to those already described by receptor autoradiography, with
high densities over the hippocampus (serotonin-1A receptors), cortex (alpha(2)
adrenoceptors) and striatum (mu-opioid receptors). The highest binding levels
were reached with the cannabinoid receptor agonist in most of the analysed brain
regions. Carbachol produced only moderate stimulation of those same regions. The
blockage of agonist-stimulated guanosine 5'-(gamma-[(35)S]thio)triphosphate
binding by selective antagonists verified that the effect was receptor mediated.
This technique provides a method to identify modifications of the receptor
mediated activation of G-proteins in post mortem human brain with anatomical
resolution. It also provides valuable information on the level of drug efficacy
in the human species.
PMID- 10683422
TI - Chronic sodium salicylate treatment exacerbates brain neurodegeneration in rats
infected with Trypanosoma brucei.
AB - We have reported previously that axonal degeneration in specific brain regions
occurs in rats infected with the parasite Trypanosoma brucei. These degenerative
changes occur in spatiotemporal association with over-expression of pro
inflammatory cytokine messenger RNAs in the brain. To test how aspirin-like anti
inflammatory drugs might alter the disease process, we fed trypanosome-infected
rats with 200mg/kg of sodium salicylate (the first metabolite of aspirin) daily
in their drinking water. Sodium salicylate treatment in uninfected rats did not
cause any neural damage. However, sodium salicylate treatment greatly exacerbated
neurodegeneration in trypanosome-infected rats, resulting in extensive terminal
and neuronal cell body degeneration in the cortex, hippocampus, striatum,
thalamus, and anterior olfactory nucleus. The exaggerated neurodegeneration,
which occurred in late stages of infection, was temporally and somewhat spatially
associated with a late-appearing enhancement of messenger RNA expression of
interleukin-1beta, interleukin-1beta converting enzyme, tumor necrosis factor
alpha, and inhibitory factor kappaBalpha in the brain parenchyma. Restricted
areas showed elevations in messenger RNA expression of interleukin-1 receptor
antagonist, interleukin-6, inducible nitric oxide synthase, interferon-gamma, and
inducible cyclooxygenase. The association suggests that increased production of
pro-inflammatory cytokines in the brain may be an underlying mechanism for neural
damage induced by the chronic sodium salicylate treatment. Furthermore, the
results reveal a serious complication in using aspirin-like drugs for the
treatment of trypanosome infection.
PMID- 10683423
TI - Microglia and astrocytes in the adult rat brain: comparative immunocytochemical
analysis demonstrates the efficacy of lipocortin 1 immunoreactivity.
AB - The distribution of glial cells (microglia and astrocytes) in different regions
of normal adult rat brain was studied using immunohistochemical techniques and
computer analysis. Lipocortin 1, phosphotyrosine, and lectin GSA B(4), were used
for identification of microglia, while S100beta and glial fibrillary acidic
protein identified astrocytes. Bioquant computerized image analysis was used to
quantify and map the immunostained cells in sections from adult rat brain. If
lipocortin 1 was used as a marker, more microglial cells were detected than with
phosphotyrosine or lectin. The lipocortin 1-positive microglial population was
most numerous (on average, 130+/-5 cells/mm(2) of the brain section area) in
neostriatum, and least (51+/-4 cells/mm(2)) in cerebellum and medulla oblongata.
In general, the density of lipocortin 1 microglia was higher in the forebrain,
and lower in the midbrain, and the least in the brainstem and cerebellum. The
number of S100beta astrocytes was two to three times larger than the number of
microglial cells, and approximately two times greater than glial fibrillary
acidic protein cells. A high density of astrocytes was found in the hypothalamus
and hippocampus (more than 260 cells/mm(2)); they were more numerous in the white
matter than in the gray matter. Fewer astrocytes were observed in the cerebral
cortex, neostriatum, midbrain, medulla oblongata and cerebellum (less than 200
cells/mm(2)). Thus lipocortin 1 and S100beta were shown to be the most specific
and reliable markers for microglia and astrocytes, respectively. The regional
population differences demonstrated for lipocortin 1 microglia and S100beta
astrocytes presumably reflect structural and functional specializations of the
certain brain regions.
PMID- 10683424
TI - Long-term superior cervical sympathectomy induces mast cell hyperplasia and
increases histamine and serotonin content in the rat dura mater.
AB - Nerve fibres and mast cells are often described in close morphological and
functional interactions in various organs such as the dura mater. The respective
roles of mast cell activation and sympathetic impairment in cluster headache and
migraine attacks have been repeatedly suggested. We have thus investigated the
long-term effects of sympathectomy on mast cell morphology and content in the rat
dura mater. Fifteen to 60 days after either sham, unilateral or bilateral
superior cervical ganglionectomy, dura were removed for either histochemical or
biochemical analysis. In the first case, they were fixed and mast cell heparin
was stained by fluorescein isothiocyanate-conjugated avidin. Microscopic
examination was followed by digital acquisitions using a tomographic process to
assess mast cell density in the whole depth of the dura mater. Unilateral
ganglionectomy induced a progressive and significant increase in mast cell
density 15-60 days post-surgery in contralateral hemi-dura and 30 days post
surgery in ipsilateral hemi-dura. This increase was significant in both dura 60
days after bilateral ganglionectomy. Following perfusion with saline, we also
examined the content of histamine and serotonin, pre-formed amines stored in mast
cell granules. Biochemical analysis of dura serotonin and histamine content using
high-pressure liquid chromatography and radioenzymatic assays, respectively,
revealed under all conditions a serotonin tissue concentration lower than that of
histamine. After sham ganglionectomy, the dura serotonin content increased from
15 to 60 days post-surgery, whereas the histamine content remained stable over
the same period. After unilateral ganglionectomy, the histamine content increased
progressively and significantly 30-60 days post-surgery in both hemi-dura,
whereas the serotonin content became significantly different from that of sham
only 60 days post-surgery in the ipsilateral dura. After bilateral
ganglionectomy, the histamine level significantly increased in both hemi-dura 15
60 days post-surgery, whereas the serotonin level had significantly increased at
60 days post-surgery. These results clearly demonstrate, for the first time, a
long-term trophic effect of sympathetic nerve degeneration on mast cells in the
dura mater. Since mast cell activation has been described previously on the
painful side of cluster headache patients during attack periods, we propose that
the sympathetic impairment reported in these patients could be prominent,
directly or indirectly inducing mast cell hyperplasia and changes in amine
contents in the tissue concerned.
PMID- 10683425
TI - Activity of foot skin mechanoreceptors and afferent nerve fibres in the adult rat
sciatic nerve are altered after central axotomy of sensory neurons.
AB - The functional properties of skin mechanoreceptors were examined in the hind foot
of normal rats in comparison with animals subjected to dorsal rhizotomy. Evoked
nerve impulses were recorded from afferent nerve fibres of the tibial nerve. The
decentralized mechanoreceptors displayed evidence of autonomous functioning, but
with several abnormalities as compared to normal animals. There was a decreased
sensitivity to mechanical stimulation and a lower adaptive capacity as a
consequence of rhizotomy. The underlying mechanism is suggested to be a loss of
central trophic support because of the interrupted link between the central
nervous system and the sensory ganglion cell periphery. The findings indicate
that mechanical receptors continue functioning under conditions when sensory
impulses flow cannot reach postsynaptic target neurons in the central nervous
system, but stop at the level of the primary sensory neuron.
PMID- 10683426
TI - Neural mechanisms of impaired micturition reflex in rats with acute partial
bladder outlet obstruction.
AB - To determine the contribution of neural elements to micturition, we evaluated, in
intact rats, the cystometrogram, pelvic afferent nervous activity, pelvic
efferent nervous activity and external urethral sphincter-electromyogram activity
in the normal and acute partial bladder outlet obstruction states. In the normal
state, in response to saline filling, mechanoreceptor-dependent pelvic afferent
nervous activity gradually activated and finally triggered a voiding reflex,
including four phases of detrusor contractions. Phase 1 was characterized by an
initial rising intravesical pressure, Phase 2 was characterized by a series of
high-frequency oscillations in intravesical pressure, Phase 3 contraction was
characterized by a rebound intravesical pressure and Phase 4 contraction was
characterized by a rapid fall in intravesical pressure. In the acute partial
bladder outlet obstruction state, Phase 1 contraction rose and high-frequency
oscillations fell in Phase 2. This voiding dysfunction is ascribed to the
bursting extraurethral sphincter activity being converted to tonic extraurethral
sphincter activity. In summary, the suppressed high-frequency oscillations in
Phase 2 of the detrusor muscle contraction could be detrimental to efficient
voidings in the acute partial bladder outlet obstructed rat.
PMID- 10683428
TI - Action potential bursts in central snail neurons elicited by d-amphetamine: roles
of ionic currents.
AB - The roles of the ionic currents in the firing of potential bursts elicited by d
amphetamine in central snail neurons were studied in the identified RP4 neuron of
the African snail, Achatina fulica Ferussac, using the two-electrode voltage
clamp method. Oscillations of membrane potential bursts were elicited by d
amphetamine. The action potential bursts elicited by d-amphetamine decreased
following intracellular injection of either EDTA or magnesium, or extracellular
application of lanthanum. Voltage-clamped studies revealed that d-amphetamine
decreased the fast Na(+), Ca(2+) and transient outward K(+) currents of the RP4
neuron. It also decreased the steady-state K(+) current and elicited a negative
slope resistance in the steady-state I-V curve between -50 and -10 mV. The
amplitude of negative slope resistance was decreased if either Na(+)-free saline
or Co(2+)-substituted Ca(2+)-free saline was perfused. d-Amphetamine did not
increase the amplitude of the slowly inactivating Ca(2+) current or the
persistent Na(+) currents of RP4 neuron. Tetraethylammonium, a blocker of the
delayed outward K(+) current, elicited action potential bursts and negative slope
resistance in the RP4 neuron, while 4-aminopyridine, an inhibitor of transient
outward K(+) current (I(A)), did not. These results demonstrate that the delayed
outward K(+) current and the negative slope resistance in steady-state I-V curve
elicited by d-amphetamine may be responsible for the action potential bursts in
central snail neurons elicited by d-amphetamine.
PMID- 10683427
TI - Embryonic expression and extracellular secretion of Xenopus slit.
AB - The slit genes have recently been found to encode proteins with a conserved
chemorepulsive activity for axons in invertebrates and vertebrates. We have
determined the expression pattern of a slit gene in Xenopus embryos. In the
neural tube, slit is expressed at the ventral and dorsal midlines, and the motor
neurons. slit is also expressed in a changing pattern in the retina. The full
length Xenopus Slit protein is secreted extracellularly, whereas its receptor
Roundabout can not be secreted. Using a myc-tagged secreted Slit protein, we
confirmed the binding of Slit to Roundabout expressed on the cell surface. These
results confirm Slit-Roundabout interactions and the biochemical properties of
Slit and Roundabout proteins, and further support the idea that Slit may guide
axon projections in multiple regions of the embryo.
PMID- 10683429
TI - Secondary carnitine deficiency and impaired docosahexaenoic (22:6n-3) acid
synthesis: a common denominator in the pathophysiology of diseases of oxidative
phosphorylation and beta-oxidation.
AB - A critical analysis of the literature of mitochondrial disorders reveals that
genetic diseases of oxidative phosphorylation are often associated with impaired
beta-oxidation, and vice versa, and preferentially affect brain, retina, heart
and skeletal muscle, tissues which depend on docosahexaenoic (22:6n-3)-containing
phospholipids for functionality. Evidence suggests that an increased NADH/NAD(+)
ratio generated by reduced flux through the respiratory chain inhibits beta
oxidation, producing secondary carnitine deficiency while increasing reactive
oxygen species and depleting alpha-tocopherol (alpha-TOC). These events result in
impairment of the recently elucidated mitochondrial pathway for synthesis of
22:6n-3-containing phospholipids, since carnitine and alpha-TOC are involved in
their biosynthesis. Therapeutic supplementation with 22:6n-3 and alpha-TOC is
suggested.
PMID- 10683430
TI - The high molecular weight isoforms of basic fibroblast growth factor (FGF-2): an
insight into an intracrine mechanism.
AB - Basic fibroblast growth factor (FGF-2) is an important modulator of cell growth
and differentiation under both physiological and pathological conditions. Until
recently, most investigations into the FGF-2 signalling pathway were concerned
with its interaction with specific membrane receptors. Nevertheless, while a 18
kDa protein of FGF-2 is cytosolic, there are also co-translated high molecular
weight (HMW) isoforms that are predominantly located in the cell nucleus. An
increasing amount of data strongly argue in favour of distinct biological
functions depending on the subcellular location of the FGF-2 species. This review
describes the evidence concerning the strictly intracellular mode of action of
the HMW isoforms of FGF-2.
PMID- 10683431
TI - Amino acids and peptides. LVII. Synthetic peptide with a sequence of ribonuclease
from Sulfolobus solfataricus, SSR(1-62), does not function as an RNase.
AB - The 62 residue peptide, SSR(1-62), whose sequence corresponds to that of
ribonuclease (RNase) from Sulfolobus solfataricus, and its related peptides,
SSR(1-22) and SSR(10-62), were chemically synthesized and their RNase activity
and DNA-binding activity were examined. The RNase activity assay using yeast RNA
or tRNA(fMet) as substrate showed that the synthetic peptide SSR(1-62) did not
hydrolyze yeast RNA or tRNA(fMet). These data were not consistent with previous
reports that both the native peptide isolated from S. solfataricus [Fusi et al.
(1993) Eur. J. Biochem. 211, 305-311] and the recombinant peptide expressed in
Escherichia coli [Fusi et al. (1995) Gene 154, 99-103] were able to hydrolyze
tRNA(fMet). However, the synthetic SSR(1-62) exhibited DNA-binding activity. In
the presence of synthetic SSR(1-62), the cleavage of DNA (plasmid pUCRh2-4) by
restriction endonuclease (EcoRI) was not observed, suggesting that synthetic
SSR(1-62) bound to DNA protected DNA from its enzymatic digestion. Neither SSR(1
22) nor SSR(10-62) prevented DNA from being cleaved by a restriction enzyme.
These findings strongly suggest the importance of not only the N-terminal region
of SSR(1-62) but also the C-terminal region for DNA-binding. Circular dichroism
spectroscopy of synthetic SSR(1-62) indicated a beta-sheet conformation, in
contrast with synthetic SSR(1-22), which exhibited an unordered conformation.
PMID- 10683432
TI - Protease activity of CND41, a chloroplast nucleoid DNA-binding protein, isolated
from cultured tobacco cells.
AB - CND41 is a 41 kDa DNA-binding protein isolated from chloroplast nucleoids of
cultured tobacco cells. The presence of the active domain of aspartic protease in
the deduced amino acid sequence of CND41 suggests that it has proteolytic
activity. To confirm this, CND41 was highly purified from cultured tobacco cells
and its proteolytic activity was characterized with fluorescein isothiocyanate
labeled hemoglobin as the substrate. The purified CND41 had strong proteolytic
activity at an acidic pH (pH 2-4). This activity was inhibited by various
chemicals, including the nucleoside triphosphates, NADPH, Fe(3+) and sodium
dodecyl sulfate.
PMID- 10683433
TI - Structural characterisation of the native fetuin-binding protein Scilla
campanulata agglutinin: a novel two-domain lectin.
AB - The three-dimensional structure of a 244-residue, multivalent, fetuin-binding
lectin, SCAfet, isolated from bluebell (Scilla campanulata) bulbs, has been
solved at 3.3 A resolution by molecular replacement using the coordinates of the
119-residue, mannose-binding lectin, SCAman, also from bluebell bulbs. Unlike
most monocot mannose-binding lectins, such as Galanthus nivalis agglutinin from
snowdrop bulbs, which fold into a single domain, SCAfet contains two domains with
approximately 55% sequence identity, joined by a linker peptide. Both domains are
made up of a 12-stranded beta-prism II fold, with three putative carbohydrate
binding sites, one on each subdomain. SCAfet binds to the complex saccharides of
various animal glycoproteins but not to simple sugars.
PMID- 10683434
TI - A peptide from the adenovirus fiber shaft forms amyloid-type fibrils.
AB - The fiber protein of adenovirus consists of a C-terminal globular head, a shaft
and a short N-terminal tail. The crystal structure of a stable domain comprising
the head plus a part of the shaft of human adenovirus type 2 fiber has recently
been solved at 2.4 A resolution [van Raaij et al. (1999) Nature 401, 935-938]. A
peptide corresponding to the portion of the shaft immediately adjacent to the
head (residues 355-396) has been synthesized chemically. The peptide failed to
assemble correctly and instead formed amyloid-type fibrils as assessed by
electron microscopy, Congo red binding and X-ray diffraction. Peptides
corresponding to the fiber shaft could provide a model system to study mechanisms
of amyloid fibril formation.
PMID- 10683435
TI - Inositol polyphosphate multikinase (ArgRIII) determines nuclear mRNA export in
Saccharomyces cerevisiae.
AB - The ARGRIII gene of Saccharomyces cerevisiae encodes a transcriptional regulator
that also has inositol polyphosphate multikinase (ipmk) activity [Saiardi et al.
(1999) Curr. Biol. 9, 1323-1326]. To investigate how inositol phosphates regulate
gene expression, we disrupted the ARGRIII gene. This mutation impaired nuclear
mRNA export, slowed cell growth, increased cellular [InsP(3)] 170-fold and
decreased [InsP(6)] 100-fold, indicating reduced phosphorylation of InsP(3) to
InsP(6). Levels of diphosphoinositol polyphosphates were decreased much less
dramatically than was InsP(6). Low levels of InsP(6), and considerable quantities
of Ins(1,3,4,5)P(4), were synthesized by an ipmk-independent route.
Transcriptional control by ipmk reflects that it is a pivotal regulator of
nuclear mRNA export via inositol phosphate metabolism.
PMID- 10683436
TI - Conjugated linoleic acid induces lipid peroxidation in humans.
AB - Conjugated linoleic acid (CLA) is shown to have chemoprotective properties in
various experimental cancer models. CLA is easily oxidised and it has been
suggested that an increased lipid oxidation may contribute to the antitumorigenic
effects. This report investigates the urinary levels of 8-iso-PGF(2alpha), a
major isoprostane and 15-keto-dihydro-PGF(2alpha), a major metabolite of
PGF(2alpha), as indicators of non-enzymatic and enzymatic lipid peroxidation
after dietary supplementation of CLA in healthy human subjects for 3 months. A
significant increase of both 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha) in
urine was observed after 3 months of daily CLA intake (4.2 g/day) as compared to
the control group (P<0.0001). Conjugated linoleic acid had no effect on the serum
alpha-tocopherol levels. However, gamma-tocopherol levels in the serum increased
significantly (P=0. 015) in the CLA-treated group. Thus, CLA may induce both non
enzymatic and enzymatic lipid peroxidation in vivo. Further studies of the
mechanism behind, and the possible consequences of, the increased lipid
peroxidation after CLA supplementation are urgently needed.
PMID- 10683437
TI - Detection of partially phosphorylated forms of ERK by monoclonal antibodies
reveals spatial regulation of ERK activity by phosphatases.
AB - When cells are stimulated by mitogens, extracellular signal-regulated kinase
(ERK) is activated by phosphorylation of its regulatory threonine (Thr) and
tyrosine (Tyr) residues. The inactivation of ERK may occur by phosphatase
mediated removal of the phosphates from these Tyr, Thr or both residues together.
In this study, antibodies that selectively recognize all combinations of
phosphorylation of the regulatory Thr and Tyr residues of ERK were developed, and
used to study the inactivation of ERK upon mitogenic stimulation. We found that
inactivation of ERK in the early stages of mitogenic stimulation involves
separate Thr and Tyr phosphatases which operate differently in the nucleus and in
the cytoplasm. Thus, ERK is differentially regulated in various subcellular
compartments to secure proper length and strength of activation, which eventually
determine the physiological outcome of many external signals.
PMID- 10683438
TI - Peroxide accumulation without major mitochondrial alteration in replicative
senescence.
AB - The aim of this work was to determine how ageing changes were related to each
other by studying the establishment of a senescent state in cell culture, rabbit
articular chondrocytes. A striking increase of the amount of peroxides appeared
at 2/3 of the time of cell growth, which is responsible for an oxidative stress,
as shown by the appearance of oxidized proteins, the overexpression of HSP27 gene
and the accumulation of HSP27 protein. While no change of the mitochondrial
membrane potential was observed all along the cell culture, p21, a protein
overproduced in senescent cells, appeared with the peak of peroxides and
accumulated.
PMID- 10683439
TI - Mirror image mutations reveal the significance of an intersubunit ion cluster in
the stability of 3-isopropylmalate dehydrogenase.
AB - The comparison of the three-dimensional structures of thermophilic (Thermus
thermophilus) and mesophilic (Escherichia coli) 3-isopropylmalate dehydrogenases
(IPMDH, EC 1.1.1.85) suggested that the existence of extra ion pairs in the
thermophilic enzyme found in the intersubunit region may be an important factor
for thermostability. As a test of our assumption, glutamine 200 in the E. coli
enzyme was turned into glutamate (Q200E mutant) to mimic the thermophilic enzyme
at this site by creating an intersubunit ion pair which can join existing ion
clusters. At the same site in the thermophilic enzyme we changed glutamate 190
into glutamine (E190Q), hereby removing the corresponding ion pair. These single
amino acid replacements resulted in increased thermostability of the mesophilic
and decreased thermostability of the thermophilic enzyme, as measured by
spectropolarimetry and differential scanning microcalorimetry.
PMID- 10683440
TI - ERK activation upon hypoxia: involvement in HIF-1 activation.
AB - Hypoxia-inducible factor-1 (HIF-1) is a transcription factor activated by
hypoxia. The HIF-1 activation transduction pathway is poorly understood. In this
report, we investigated the activation of extracellular regulated kinases (ERK)
in hypoxia and their involvement in HIF-1 activation. We demonstrated that in
human microvascular endothelial cells-1 (HMEC-1), ERK kinases are activated
during hypoxia. Using dominant negative mutants, we showed that ERK1 is needed
for hypoxia-induced HIF-1 transactivation activity. Moreover, using a kinase
assay and Western blot experiments, we showed that HIF-1alpha is phosphorylated
in hypoxia by an ERK-dependent pathway. These results evidence the role of
mitogen-activated protein kinase in the transcriptional response to hypoxia.
PMID- 10683441
TI - The gene encoding DRAP (BACE2), a glycosylated transmembrane protein of the
aspartic protease family, maps to the down critical region.
AB - We applied cDNA selection methods to a genomic clone (YAC 761B5) from chromosome
21 located in the so-called 'Down critical region' in 21q22.3. Starting from
human fetal heart and brain mRNAs we obtained and sequenced several cDNA clones.
One of these clones (Down region aspartic protease (DRAP), named also BACE2
according to the gene nomenclature) revealed a striking nucleotide and amino acid
sequence identity with several motifs present in members of the aspartic protease
family. In particular the amino acid sequences comprising the two catalytic sites
found in all mammalian aspartic proteases are perfectly conserved. Interestingly,
the predicted protein shows a typical membrane spanning region; this is at
variance with most other known aspartic proteases, which are soluble molecules.
We present preliminary evidence, on the basis of in vitro translation studies and
cell transfection, that this gene encodes a glycosylated protein which localizes
mainly intracellularly but to some extent also to the plasma membrane.
Furthermore DRAP/BACE2 shares a high homology with a newly described beta
secretase enzyme (BACE-1) which is a transmembrane aspartic protease. The
implications of this finding for Down syndrome are discussed.
PMID- 10683442
TI - A rev-like NES mediates cytoplasmic localization of HERV-K cORF.
AB - The human endogenous retrovirus K (HERV-K)-encoded protein cORF has recently been
shown to be a functional homolog of the HIV Rev protein. Rev-mediated RNA export
requires interaction between a leucine-rich nuclear export signal (NES) in Rev
and the nuclear export receptor Crm1/exportin1. Like Rev, cORF binds to Crm1 and
cORF-mediated RNA export depends on Crm1 activity. Here we document that mutation
of the putative NES in cORF results in trapping of the protein in the nucleus,
suggesting that the cORF NES functions in analogy to the Rev NES.
PMID- 10683443
TI - Intra- and intermolecular interactions of the catalytic domains of human CD45
protein tyrosine phosphatase.
AB - We have investigated protein-protein interaction between distinct domains of the
human CD45 cytoplasmic region using a yeast two-hybrid system. Consequently, we
have found that the spacer region between two tandem PTP domains specifically
interacts with the membrane-distal PTP domain (D2). This interaction is mediated
by a stretch of amino acid residues in the carboxyl-terminal half of the spacer
region. Although the membrane proximal region does not directly interact with
either of the two PTP domains, it appears to function in stabilizing the
interaction between the spacer region and D2. We also demonstrate that the
interaction between the spacer region and D2 might take place intramolecularly.
PMID- 10683444
TI - Reinitiation of protein synthesis in Escherichia coli can be induced by mRNA cis
elements unrelated to canonical translation initiation signals.
AB - In Eubacteria, de novo translation of some internal cistrons may be inefficient
or impossible unless the 5' neighboring cistron is also translated (translational
coupling). Translation reinitiation is an extreme case of translational coupling
in which translation of a message depends entirely on the presence of a nearby
terminating ribosome. In this work, the characteristics of mRNA cis-elements
inducing the reinitiation process in Escherichia coli have been investigated
using a combinatorial approach. A number of novel translational reinitiation
sequences (TRSs) were thus identified, which show a wide range of reinitiation
activities fully dependent on a translational coupling event and unrelated to the
presence/absence of secondary structure or mRNA stability. Moreover, some of the
isolated TRSs are similar to intercistronic sequences present in the E. coli
genome.
PMID- 10683445
TI - Biosynthesis of dystroglycan: processing of a precursor propeptide.
AB - Dystroglycan is a cytoskeleton-linked extracellular matrix receptor expressed in
many cell types. Dystroglycan is composed of alpha- and beta-subunits which are
encoded by a single mRNA. Using a heterologous mammalian expression system, we
provide the first biochemical evidence of the alpha/beta-dystroglycan precursor
propeptide prior to enzymatic cleavage. This 160 kDa dystroglycan propeptide is
processed into alpha- and beta-dystroglycan (120 kDa and 43 kDa, respectively).
We also demonstrate that the precursor propeptide is glycosylated and that
blockade of asparagine-linked (N-linked) glycosylation did not prevent the
cleavage of the dystroglycan precursor peptide. However, inhibition of N-linked
glycosylation results in aberrant trafficking of the alpha- and beta-dystroglycan
subunits to the plasma membrane. Thus, dystroglycan is synthesized as a precursor
propeptide that is post-translationally cleaved and differentially glycosylated
to yield alpha- and beta-dystroglycan.
PMID- 10683446
TI - A conserved small GTP-binding protein Alp41 is essential for the cofactor
dependent biogenesis of microtubules in fission yeast.
AB - The proper folding of tubulins and their incorporation into microtubules consist
of a series of reactions, in which evolutionarily conserved proteins, cofactors A
to E, play a vital role. We have cloned a fission yeast gene (alp41(+)) which
encodes a highly conserved small GTP-binding protein homologous to budding yeast
CIN4 and human ARF-like Arl2. alp41(+) is essential, disruption of which results
in microtubule dysfunction and growth polarity defects. Genetic analysis
indicates that Alp41 plays a crucial role in the cofactor-dependent pathway, in
which it functions upstream of the cofactor D homologue Alp1(D) and possibly in
concert with Alp21(E).
PMID- 10683447
TI - Simultaneous production of nitric oxide and peroxynitrite by plant nitrate
reductase: in vitro evidence for the NR-dependent formation of active nitrogen
species.
AB - We examined the ability of plant nitrate reductase (NR) to produce nitric oxide
(NO) using in vitro assays. Electrochemical and fluorometric measurements both
showed that NO is produced by corn NR in the presence of nitrite and NADH at pH
7. The NO production was inhibited by sodium azide, a known inhibitor for NR.
During the reaction, absorbance of 2',7'-dichlorodihydrofluorescein increased
markedly. This change was completely suppressed by sodium azide, glutathione or
depletion of oxygen. We conclude that plant NR produces both NO and its toxic
derivative, peroxynitrite, under aerobic conditions when nitrite is provided as
the substrate for NR.
PMID- 10683448
TI - Cloning, genomic organization, chromosomal assignment and expression of a novel
mosaic serine proteinase: epitheliasin.
AB - We report the isolation of a cDNA encoding a novel murine serine proteinase,
epitheliasin. The cDNA spans 1753 bp and encodes a mosaic protein with a
calculated molecular mass of 53529 Da. Its domains include a cytoplasmic tail, a
type II transmembrane domain, a low-density lipoprotein receptor class A domain,
a cysteine rich scavenger receptor-like domain and a serine proteinase domain.
The proteinase portion domain shows 46-53% identity with mouse neurotrypsin,
acrosin, hepsin and enteropeptidase. The gene, located in the telomeric region in
the long arm of mouse chromosome 16, consists of 14 exons and 13 introns and
spans approximately 18 kb. Epitheliasin is expressed primarily in the apical
surfaces of renal tubular and airway epithelial cells.
PMID- 10683449
TI - Structure of the cytosolic domain of TOM5, a mitochondrial import protein.
AB - TOM5 is a small outer mitochondrial membrane protein in Saccharomyces cerevisiae
and is part of a multi-protein translocator complex, which mediates protein
import into mitochondria. Presently, nothing is known about the conformational
preferences of TOM5 or other mitochondrial import proteins. In this report,
circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy are
used to determine the conformational preferences of the cytosolic domain of TOM5.
The CD spectra show evidence of a helical structure that is invariant with pH.
NOESY data revealed that TOM5 forms a stable helical core between E11 and R15
with a less structurally rigid helix extending to the C-terminus.
PMID- 10683450
TI - The scintillating grid illusion in stereo-depth.
AB - The dark scintillating dots occurring on a gray-on-black, modified Hermann grid
[Schrauf, M., Lingelbach, B., & Wist, E. R. (1997). The scintillating grid
illusion. Vision Research, 37, 1033-1038] were studied in stereo-depth by
assigning various degrees of disparity to the white inducing disks. Dependent on
the sign of disparity, the disks and the dark illusory spots within them appeared
to lie either in the same plane, in front of, or behind the grid. At zero
disparity, illusory strength was maximum and was the same for stereo, binocular
and monocular viewing. With increasing disparity, the illusion became
progressively weaker; however, the decrease for stereo-patterns was significantly
less than for control patterns presented binocularly or monocularly. These
results suggest a central contribution to the scintillation effect.
PMID- 10683451
TI - The structure of colour naming space.
AB - An experiment is described which replicates recent name mapping work, and delves
further into the detailed structure of colour naming space. Observers freely
named 1044 CRT-displayed colour-background combinations, sampled regularly along
the (u',v') axes of the 1976 UCS, and along a luminance axis. Three response
measures - response times, confidence ratings and consistencies - were obtained.
These measures were collapsed by principal components analysis (PCA) into
'nameability', a single measure of ease of naming of colours. The structure of
colour naming space and the use of different colour name types, were
investigated. Data confirmed the uniqueness of basic colour terms as compared
with the non-basic terms, agreeing with previous constrained naming studies.
Colour naming space was found to exhibit regular structure, which appears to be
linked to fundamental response categories, and to previous observations that
colour naming space may be divided into five major regions.
PMID- 10683452
TI - Slow discrimination of contrast-defined expansion patterns.
AB - We compared observers' performance in the same complex motion discrimination task
using stimuli defined by luminance or by contrast. They were asked to
discriminate between a centred expansion pattern, constructed from four patches
of outwards motion, and a distorted expansion pattern, constructed with one patch
containing inwards motion and three patches containing outwards motion. We
measured performance versus duration and found that for luminance-defined
patterns, observers were able to discriminate correctly between these patterns in
75% of trials when the stimulus duration was 200 ms. For contrast-defined
patterns, observers required over 2 s to reach this level of performance.
Observers did not require such long durations to discriminate correctly between
the contrast-defined expansion patterns when the patterns contained fewer patches
or when the distorted patterns contained more patches of inwards motion. This
suggests that observers performed the task by searching for a patch that
contained a pattern moving inwards. There was no such effect on performance with
the luminance-defined patterns. These results also suggest that contrast-defined
patterns are processed too slowly to provide an input to specialised optic flow
detectors that guide navigation in real time. Further, the differences in
performance may be due to processing delays from sequential processing of the
contrast-defined local motion signals.
PMID- 10683453
TI - Spatial resolution and receptive field height of motion sensors in human vision.
AB - We estimated the length of motion-detecting receptive fields in human vision by
measuring direction discrimination for three novel stimuli. The motion sequences
contained either (i) alternate frames of two differently oriented sinusoidal
gratings; (ii) alternate frames of vertical grating and plaid stimuli or (iii) a
vertical grating divided into horizontal strips of equal height, where alternate
strips moved leftward and rightward. All three stimulus sequences had a similar
appearance (of moving strips) and the task was to identify the direction of the
central strip. For sequences (ii) and (iii), performance fell as the strip height
decreased. Threshold height fell with increasing contrast up to about 20%, then
levelled off at the critical strip height. Temporal frequency (1. 9-15 Hz) had no
effect on the critical strip height. We argue that the receptive field length
corresponds to twice this critical height. The length estimates were strikingly
short, ranging from about 0.4 cycles at 3.0 cpd to 0.1 cycles at 0.1 cpd. These
lengths agree well with the estimates derived at threshold by Anderson and Burr
(1991, J. Opt. Soc. Am. A8, 1330-1339), and imply that the motion-sensing filters
have very broad orientation tuning. These and other results are interpreted
within the framework of a Gaussian derivative model for motion filtering. The
sensitivity of motion filters to a broad range of orientations suggests a simpler
view of how coherent plaid motion is processed.
PMID- 10683454
TI - Spatial localization of colour and luminance stimuli in human peripheral vision.
AB - A variety of studies suggest the localization of objects in three-dimensional
space is predominantly the task of the magnocellular (M) system, and conversely
that the parvocellular (P) system plays little or no role in localization.
However, there are conflicting reports and the goal of this paper was to
determine whether spatial localization is predominantly accomplished by one or
the other visual system. Both manual pointing and three-target alignment
protocols were used to measure localization accuracy for eccentrically presented
patches of a sinewave grating. Two general approaches were adopted to activate
preferentially one or the other pathway: (1) we varied the spatio-temporal
frequency, contrast and chromatic properties of the stimulus to conform with the
physiological response properties of either M or P cells; and (2) some
measurements were made both with steady fixation and during large saccades, as
the latter have been reported to cause selective suppression of the M system
[Burr, Morrone & Ross (1994). Nature, 371, 511-513]. Each stimulus was presented
at or near its detection contrast threshold, which was determined separately for
each visual field location using forced-choice procedures. Using manual pointing,
both M- and P-type stimuli were localized to within about 1.3 degrees at retinal
eccentricities near 10 degrees. This accuracy was not affected by distractor
targets in the peripheral field or temporal uncertainty in stimulus presentation,
but was reduced by a similar amount for each stimulus type during saccadic eye
movements. Using the alignment task, localization accuracy remained at about 1.3
degrees for P-type stimuli but improved to 0.5 degrees for M-type stimuli. We
conclude that both M and P systems play an equally important role in localizing
peripheral targets for the purpose of visuo-motor tasks such as pointing, but
that the M system may offer an advantage over the P system for the perceptual
task of localizing a stimulus relative to nearby targets.
PMID- 10683455
TI - Detection of chromoluminance patterns on chromoluminance pedestals I: threshold
measurements.
AB - Measurement of the detection thresholds of patterns on pedestals of various kinds
has the potential of providing insight into the mechanisms that mediate pattern
vision. This study is concerned with chromoluminance patterns, that is, patterns
that vary over space in luminance, chromaticity, or both. Contrast thresholds for
1 c/deg Gabor patterns (targets) were measured as a function of the contrast of
Gabor pedestal patterns (TvC functions), where the pedestals paired with each
target were modulated in a wide range of directions in color space. For most
target-pedestal pairs, the TvC function decreased (facilitation) and then
increased as pedestal contrast increased. The increase went above the absolute
contrast threshold (masking) for all target-pedestal pairs except in cases where
facilitation occurred at the upper end of the pedestal contrast range. The
specific form of the TvC function varied greatly with the target and pedestal,
consistent with a general model of pedestal effects proposed by Foley [Journal of
the Optical Society of America A, 1994, 11(6)]. There were two sets of target
pedestal pairs for which facilitation did not occur, but masking did occur: pairs
in which the target was a luminance modulation and the pedestals were
individually isoluminant and pairs in which the pedestal was blue/yellow and the
target was in any of our directions except blue/yellow.
PMID- 10683456
TI - Detection of chromoluminance patterns on chromoluminance pedestals II: model.
AB - A model for chromoluminance pattern detection and pedestal effects is described.
This model has five stages. The stimulus is first processed by the cone array and
then by color-spatial linear operators. The outputs of the linear operators may
be expressed as weighted sums of cone contrasts over space. There are three
opposite sign pairs of linear spatial operators in the model. Their spectral
tuning at each point in space is similar to the luminance, green/red and
blue/yellow mechanisms in color opponent models, but their sensitivity to cone
inputs varies as a function of space. The operators in each pair are the same
except that the signs of the cone inputs in one are the opposite of those in the
other. A non-linear response operator follows each linear operator. It receives
two inputs, one excitatory and the other divisive inhibitory. The excitatory
input is the half-wave rectified output of one of the linear operators. The
inhibitory input is a non-linear sum of all linear operator outputs. The non
linear response operator raises the excitatory input to a power, and divides it
by the inhibitory input plus a constant to produce the response. The detection
variable is computed by combining the difference in response to target-plus
pedestal and pedestal alone across the three non-linear operators. The model
accounts well for the large data set presented in the companion paper and is
generally consistent with other results in the literature. The spectral
sensitivities of the inferred chromoluminance pattern mechanisms are similar to
those obtained with different methods. The data set is shown to be inconsistent
with several other models.
PMID- 10683457
TI - Dynamic random noise shrinks the twinkling aftereffect induced by artificial
scotomas.
AB - Physiological alterations in cortical neurons are induced during adaptation to an
artificial scotoma, a small homogeneous patch within a dynamic random noise or
patterned background. When the dynamic noise is replaced by an equiluminant gray
background, a twinkling aftereffect can be seen in the location of the artificial
scotoma. Following binocular adaptation, we discovered that the perceived size of
the twinkling aftereffect was dramatically smaller than the inducing artificial
scotoma. Dichoptic adaptation induced shrinkage in the twinkling aftereffect that
was similar to that found after binocular adaptation, suggesting that the
twinkling aftereffect and its shrinkage both have cortical origins. We speculate
that this perceptual shrinkage may reflect the interaction between two cortical
mechanisms: a twinkling aftereffect mechanism that spreads throughout the
artificial scotoma, and a filling-in mechanism that has a greater influence at
the edges of the artificial scotoma and spreads inwards.
PMID- 10683458
TI - Chromatic and luminance contributions to a hyperacuity task.
AB - Displacement thresholds with incremental chromatic and luminance edges were
measured on different backgrounds. Above 3% luminance contrast, thresholds were
always similar. At luminance contrasts below 3%, luminance edges could not be
detected, but chromatic edges were still visible. At these low contrasts
displacement thresholds for chromatic edges increased to a high level. We
interpret these data in terms of multiple mechanisms; above 3% contrast a
luminance mechanism determines thresholds, but when, at lower contrasts,
chromatic mechanisms support detection, they also support the spatial task.
Physiological data were consistent with the different mechanisms originating at
the retinal ganglion cell level.
PMID- 10683459
TI - The role of relative motion computation in 'direction repulsion'.
AB - When two sets of intermixed dots move in different directions the perceived
direction of each is considerably shifted [Marshak & Sekuler (1979). Science,
205, 1399-1401; Mather & Moulden, (1980). Quarterly Journal of Experimental
Psychology, 32, 325-333)]. This phenomenon has been attributed to 'repulsive'
interactions between channels tuned to different directions of motion. However,
we report that it is not only the relative direction, but also the density and
speed of the sets, which determines the magnitude of the apparent shift. These
results are difficult to reconcile with the notion of 'repulsive' interactions,
and we describe an alternative, functionally motivated explanation. In the
natural environment, observed motion results from objects moving over background
surfaces that may themselves be mobile. Disentanglement of motion signals
therefore necessitates a computation of relative motion. We propose that the
phenomenon of 'direction repulsion' results from a deliberate adjustment of
observed motion to compensate for an inferred source of 'background' motion. A
simple scheme to do this subtracts the weighted vector-sum of all motion signals
from observed motion. This relative motion computation quantitatively predicts
the observed effects of the density of dot sets on perceived direction. The
effects of speed cannot be reconciled with the scheme as it stands, but this
could be due to the model's failure to consider the effect of temporal frequency
on the effective contrast of the sets.
PMID- 10683460
TI - Image formation by bifocal lenses in a trilobite eye?
AB - In this work we report on a unique and ancient type of eye, in which the lower
surface of the upper calcite lens units possessed an enigmatic central bulge
making the dioptric apparatus similar to a bifocal lens. This eye belonged to the
trilobite Dalmanitina socialis, which became extinct several hundred million
years ago. As far as we know, image formation by bifocal lenses of this kind
did/does not occur in any other ancient or modern animal visual system. We
suggest that the function of these bifocal lenses may be to enable the trilobite
to see simultaneously both very near (e.g. floating food particles and tiny
preys) and far (e.g. sea floor, conspecifics, or approaching enemies) in the
optical environment through the central and peripheral lens region, respectively.
This was the only reasonable function we could find to explain the puzzling lens
shape. We admit that it is not clear whether bifocality was necessary for the
animal studied. We show that the misleading and accidental resemblance of an
erroneous correcting lens surface (designed by Rene DesCartes in 1637 [DesCartes,
R. (1637). Oeuvres de DesCartes. La Geometrie. Livre 2. pp. 134. J. Maire,
Leyden] to the correcting interface in the compound Dalmanitina lens may be the
reason why the earlier students of the Dalmanitina lens did not recognize its
possible bifocality.
PMID- 10683461
TI - Spatial pooling in the second-order spatial structure of cortical complex cells.
AB - We investigate what computational mechanisms give rise to the nonlinearity of
complex cell responses in the primary visual cortex. Complex cells are
characterized by their nonlinear spatial properties such as spatial phase
invariance and nonlinear spatial additivity. We carried out network simulations
to estimate the second-order Wiener-like kernels for several different models.
Models with nonlinear spatial pooling of simple-cell-like linear subunits
reproduce the second-order kernels in good agreement with physiologically
estimated kernels, while models without the pooling mechanism fail to reproduce
the kernel. The results support the cascade mechanism consisting of simple cells'
local feature extraction followed by spatial pooling.
PMID- 10683462
TI - Analysis by enzyme-linked immunosorbent assay and immunoblot of the antibody
responses of patients infected with Mycobacterium marinum.
AB - The serum antibody responses of a total of 14 patients with active or recently
cured Mycobacterium marinum infections were analysed via a combination of enzyme
linked immunosorbent assay (ELISA) and the immunodevelopment of Western blots of
M. marinum antigen. Normal human sera and sera from patients with active
pulmonary tuberculosis were also analysed as controls. The detectable IgG
response of M. marinum patients, as demonstrated by ELISA, was highly variable
and did not differ significantly from normal controls. IgA and IgM levels were
generally low in the M. marinum patients and were not significantly different
from normal controls. Immunodevelopment of Western blots of M. marinum antigen
with the sera of patients with M. marinum infections revealed that a number of
antigens were recognised. Of particular note was an 18-kDa species that was
recognised by 11 out of 14 patients (and by none of the normal controls). The 18
kDa antigen may be a useful serodiagnostic marker in the identification of M.
marinum infections.
PMID- 10683463
TI - Involvement of endogenously synthesized interleukin (IL)-18 in the protective
effects of IL-12 against pulmonary infection with Cryptococcus neoformans in
mice.
AB - We previously demonstrated that interleukin (IL)-12 protected mice against fatal
pulmonary infection with a highly virulent strain of Cryptococcus neoformans,
which correlated well with the production of interferon (IFN)-gamma as well as IL
18 in the primary infected site. In the present study, we examined the role of
endogenously synthesized IL-18 in IL-12-induced host resistance to this pathogen.
There was little or no production of IFN-gamma and IL-18 both at mRNA and protein
levels in lungs of mice infected with C. neoformans, while treatment with IL-12
induced a marked production of these cytokines. Caspase-1 mRNA was expressed in
infected mice even without IL-12 treatment. Administration of neutralizing anti
IFN-gamma monoclonal antibody (mAb) clearly inhibited production of IFN-gamma and
IL-18 induced by IL-12, while control IgG did not show such an effect. However,
administration of IFN-gamma did not induce the production of both cytokines in
infected mice, although tumor necrosis factor (TNF)-alpha and IFN-gamma-inducible
protein (IP)-10 were synthesized by the same treatment. Finally, neutralizing
anti-IL-18 antibody (Ab) significantly interfered with the production of IFN
gamma and elimination of the microorganism from the lung induced by IL-12
treatment. Furthermore, both IFN-gamma synthesis and host protection caused by IL
12 were profoundly diminished in IL-18 gene-disrupted mice. Considered
collectively, our results indicated that host protection against C. neoformans
induced by IL-12 involved endogenously synthesized IL-18 and that the production
of IL-18 was mediated at least in part by endogenous IFN-gamma.
PMID- 10683464
TI - Prevention of endotoxin-induced lethality in mice by calmodulin kinase activator.
AB - Porphyromonas gingivalis strain 381 lipid A showed lower activity in inducing
interleukin (IL)-1alpha and IL-1beta production and cytokine mRNA expression than
synthetic Escherichia coli lipid A (compound 506) in alveolar macrophages of
C57BL/6 mice. Both the lipid As induced tumor necrosis factor alpha in alveolar
macrophages and IL-6 in peritoneal macrophages. A calmodulin (CaM) antagonist, W
7, inhibited IL-1beta production and its mRNA expression induced by P. gingivalis
lipid A but not compound 506 in alveolar macrophages. A CaM kinase activator
reduced the induction of IL-1beta in the serum of mice when administered with
compound 506, and protected the mice against the lethal toxicity. The modulation
of a variety of intracellular enzymes including the CaM kinase may result in
clinical control of endotoxic sepsis.
PMID- 10683465
TI - Correlation between the immune response elicited in rabbits by env-recombinant
avipox vaccines and the inhibition of HIV-1-specific functions.
AB - The fine immunoreactivity of the rabbit humoral response elicited by four env
recombinant avipoxviruses and their ability to stimulate a memory T-cell response
and a protective immunity have been studied. The antibody specificity was
compared with the serum neutralizing activity and virus-specific T-cell
proliferative response. Resistance to challenge by cell-associated HIV-1 was
monitored by PCR. Canarypox (CP) and fowlpox (FP) constructs, containing the
complete env gene (IS(+)) from the HIV-1(SF2) strain, induced a higher profile of
epitope recognition than their counterparts expressing the env gene deleted of
the putative immunosuppressive region (IS(-)). Serum neutralizing activity was in
agreement with fusion inhibition and lymphoproliferative response in rabbits
immunized with CPIS(+), and only partially with FPIS(+). Rabbits failed to be
infected, but anti- p55 gag-specific antibodies could be demonstrated by Western
blot. This study confirms the ability of these non-replicative live recombinant
viruses to elicit a complete immune response, capable of inhibiting specific HIV
1 functions.
PMID- 10683466
TI - Immunochemical aspects of Hafnia alvei O antigens.
AB - In the article the composition and structure of the O-specific polysaccharide
chains and core region of the O antigens isolated from over 20 H. alvei strains
is overviewed. Moreover, the correlation between the structure and
immunospecificity of the O antigens is presented and discussed.
PMID- 10683467
TI - Immunogenicity of in vitro folded outer membrane protein PorA of Neisseria
meningitidis.
AB - In vitro folded and the denatured form of PorA P1.6 from Neisseria meningitidis
strain M990 were used for immunization studies in mice. Previously, the antigen
was isolated from cytoplasmic inclusion bodies, folded and purified. Its
immunogenicity without adjuvant appeared to be low. The addition of the adjuvant
QuilA, but not of galE lipooligosaccharide, considerably enhanced the
immunogenicity. Moreover, when immunized with folded PorA P1.6 plus QuilA, a
clear switch towards the IgG2a subclass of antibodies and concomitantly, the
appearance of serum bactericidal activity, which is believed to be important for
protective immunity, was observed. Hence, a tool for preparing vaccines against
serogroup B meningococci devoid of endotoxin is available.
PMID- 10683468
TI - Apoptosis of human keratinocytes after bacterial invasion.
AB - In this study, we examined the invasive capacity of Staphylococcus aureus and
Salmonella typhi in human keratinocytes and monitored the number of viable
intracellular bacteria at different post-infection times. The strains tested
entered keratinocytes; both S. typhi and S. aureus were internalized within 30
min to 2 h after infection. No intracellular multiplication was observed, but S.
typhi and S. aureus remained viable 72 h after infection. We also demonstrated
that keratinocyte death following S. typhi and S. aureus invasion occurs by
apoptosis as shown by DNA fragmentation. After 24 h of infection with S. typhi,
the number of cells undergoing apoptosis were higher compared to infection with
S. aureus. For prolonged infection times (48 h, 72 h) with both bacteria, there
was no significant change in the number of cells undergoing apoptosis. The
results demonstrated that viable intracellular S. typhi and S. aureus induced
apoptosis in keratinocyte cells.
PMID- 10683469
TI - Isolation and characterization of a human neutrophil aggregation defective mutant
of Fusobacterium nucleatum.
AB - Fusobacterium nucleatum is known to adhere to human polymorphonuclear neutrophils
(PMNs) and cause them to aggregate. In this study, we isolated a spontaneously
occurring aggregation defective (AGG(-)) mutant and this mutant will be used for
future study of the interactions between this bacterium and human PMN. Genomic
DNA fingerprinting by random-primed polymerase chain reaction method revealed a
difference between the parent strain and the AGG(-) mutant. This mutant also
showed an altered phenotype in both microbicidal and phagocytic assays,
suggesting that the bacterial factor involved in the aggregation may also be very
important for the phagocytosis and, subsequently, the killing by human PMNs.
Further study of this mutant may help to clarify the molecular mechanisms of the
interaction between this pathogen and human PMNs.
PMID- 10683470
TI - Impairment of T-cell functions with the progressive ascitic growth of a
transplantable T-cell lymphoma of spontaneous origin.
AB - It has been observed that the progressive ascitic growth of a transplantable T
cell lymphoma of spontaneous origin, designated Dalton's lymphoma (DL), in a
murine host induces inhibition of various immune responses and is associated with
an involution of thymus accompanied by a massive depletion of the cortical region
and alteration in the distribution of thymocytes caused by tumour serum-dependent
induction of apoptosis with a decrease of CD4(+)CD8(+), CD4(+)CD8(-) and CD4(
)CD8(+) thymocytes. Here, we report that thymocytes of DL-bearing mice are
defective in their proliferative ability and in their response to non-specific
mitogenic stimulus in vitro. Also, antigen-specific T-cell proliferative ability
representing the fundamental T(H) function declines under DL-bearing conditions
and upon treatment with serum of DL-bearing mice. Moreover, a significant
inhibition of T-cell cytolytic activity with a decreased ability to produce
interferon gamma is shown by the T cells of DL-bearing mice and by the T cells
treated with DL-ascitic fluid, DL-conditioned medium or serum of DL-bearing mice.
Further, addition of interleukin-2 and anti-interleukin-10 to the cultures of
thymocytes treated with serum of DL-bearing mice is found to inhibit the
induction of apoptosis in thymocytes, a phenomenon associated with the
progression of DL growth. Analysis of the results indicates an immune deviation
with the predominance of a T(H2)-type response with the progression of tumour. We
further discuss the possible mechanisms that may explain the observed tumour
induced diminution of T-cell immunity.
PMID- 10683471
TI - Endocardiac infectivity and binding to extracellular matrix proteins of oral
Abiotrophia species.
AB - Microorganisms of the genus Abiotrophia, formerly known as nutritionally variant
streptococci, are members of the oral flora and often isolated from patients with
endocarditis, but pathogenicity of oral Abiotrophia species has not been examined
yet. In this study, 17 strains isolated from healthy human oral cavities and 7
reference strains (all derived from patients with endocarditis) of Abiotrophia
spp. were tested for their abilities to cause infections in damaged heart tissues
in catheterized rats and to adhere to extracellular matrix proteins in vitro. The
reference strains of A. defectiva and A. adiacens showed high infectivities in
the rats. Four oral isolates of these two species showed similarly high
infectivities and three had moderate infectivities. Most of 10 oral strains of A.
para-adiacens and A. elegans were found to be generally less infective. The
highly infective A. adiacens strains showed markedly high fibronectin-binding
capacity, suggesting a possible relationship between the fibronectin-binding
capacity and damaged heart tissue infectivity of the Abiotrophia species. A.
defectiva strains which were also highly infective had moderate levels of binding
to fibronectin and other extracellular matrix proteins. Most of A. para-adiacens
and A. elegans strains showed low or negligible binding capacities to any
extracellular matrix proteins tested.
PMID- 10683472
TI - Immunogens of interest for the diagnosis of Campylobacter jejuni infections.
AB - In order to identify the C. jejuni immunogens of interest for the diagnosis of
Campylobacter infections, we analyzed the humoral response of 153 patients by
using complement fixation (CF) and western blot assays. A first group of 79 sera
was from C. jejuni infected patients suffering from enteritis (n=16), Guillain
Barre syndrome (GBS) (n=40) and arthritis (n=23). A second group of 49 sera was
from healthy blood donors and a third group consisted of 25 sera from children
under 4 years old. Using the CF test, 88.6% of the C. jejuni infected patients
were seropositive versus 28.5% of the healthy blood donors and none of the
children. The Western blot assay allowed detection of antibodies directed against
seven selected antigens ranging from 14 to 67 kDa. Three of these antigens with a
molecular size of 29, 37 and 43 kDa were detected by 86.0%, 84.8% and 91.1% of
the C. jejuni infected patients, respectively. These three antigens seem to be
good candidates for the development of assays suitable for direct and indirect
diagnosis of Campylobacter infections.
PMID- 10683473
TI - Differences in the consumption of ethanol and flavored solutions in three strains
of rats.
AB - Several studies have shown a correlation between ethanol consumption and the
intake of flavored solutions in rats, particularly sweet solutions. This
observation, however, has not been shown in all strains of rats. The present
study examined whether the intake of ethanol and that of flavored solutions would
be related in Lewis (LEW), Wistar (WIS), and Wistar Kyoto (WKY) rats. During
phase I, all rats were presented with water and a flavored solution following a
continuous access paradigm as developed by Overstreet et al.: quinine (0.25%
wt/vol), saccharin (0.1% wt/vol), ethanol (ETOH) (10% vol/vol), and saccharin
quinine (SQ) solutions (0.4% wt/vol-0.04% wt/vol). During phase II, fluid
presentations were reduced to a 10-min limited access schedule and were presented
in the same order. Results showed strain differences in intake and preference for
ETOH and SQ during both phases, but not in quinine or saccharin intake. ETOH and
saccharin intake were only correlated in the LEW strain during limited access
drinking, while ETOH and SQ intake were correlated in the LEW strain as well as
when all strains were collapsed during continuous drinking. These findings
suggested that any association between ETOH and sweet intake may not be
generalizable to all rat strains. The animals used in this study may have
differed in taste sensitivity, as low ETOH-consuming LEW rats were sensitive to
the bitter taste of quinine alone, as well as when mixed with saccharin.
Sensitivity to bitter tastes may be an important predictor of low ETOH
consumption and/or preference. These data provide further evidence for the role
of taste factors in the mediation of voluntary ETOH consumption in rats.
PMID- 10683474
TI - Modulation of memory processing in the cingulate cortex of mice.
AB - To evaluate the possible role of the cingulate cortex in memory processing for
training using a noxious stimulus, we trained mice on foot shock avoidance in a T
maze. Cholinergic, GABAergic, serotonergic, and glutamatergic agonists and
antagonists were administered into the cingulate cortex immediately after
training. Retention for the foot shock avoidance training was tested 1 week
later. The results indicate that muscarinic and nicotinic agonists improved
retention, while antagonists impaired it. GABA and serotonin agonists impaired
retention, while antagonists improved it. Drugs acting on GABA(A) and GABA(B)
receptors had similar effects on retention, as did drugs acting on serotonin 1
and 2 receptor subtypes. Glutamate improved retention, and AP5, an antagonist of
the excitatory amino acid site of the NMDA receptor, impaired retention. The
cingulate cortex, like other parts of the limbic system, is involved in memory
processing that occurs shortly after training.
PMID- 10683475
TI - Supraadditive effect of d-fenfluramine plus phentermine on extracellular
acetylcholine in the nucleus accumbens: possible mechanism for inhibition of
excessive feeding and drug abuse.
AB - The combination of d-fenfluramine plus phentermine (d-FEN/PHEN) provides a tool
for exploring neural mechanisms that control food intake and drug abuse. Prior
research suggests that dopamine (DA) in the nucleus accumbens can reinforce
appetitive behavior and acetylcholine (ACh) inhibits it. When rats were given d
fenfluramine (5 mg/kg, IP) DA increased to 169% (p < 0.01), and ACh decreased
slightly. Phentermine (5 mg/kg, IP) increased extracellular DA to 469% of
baseline and ACh increased slightly to 124% (both p < 0.01). The d-FEN/PHEN
combination, however, increased both DA and ACh with a supraadditive effect on
ACh to 172%. One interpretation is that dFEN/PHEN increases DA like a meal or
drug of abuse, while also increasing ACh to stop further approach behavior. This
leaves the animal "satiated," as defined by reduced intake of food or drugs.
PMID- 10683476
TI - Acetylcholine release in ventral tegmental area by hypothalamic self-stimulation,
eating, and drinking.
AB - Evidence is presented for an acetylcholine (ACh) input to the midbrain ventral
tegmental area (VTA) as part of a system for self-stimulation and ingestive
behavior. Male rats were prepared with an electrode in the perifornical lateral
hypothalamus and an ipsilateral guideshaft for microdialysis in the VTA.
Extracellular ACh increased in the VTA during self-stimulation, auto-stimulation,
eating, or drinking. Infusion of atropine into the VTA via the microdialysis
probe was sufficient to stop self-stimulation and reduce intake of food. It is
concluded that ACh acts at muscarinic receptors in the VTA as part of a circuit
that modulates hypothalamic self-stimulation and ingestive behavior.
PMID- 10683477
TI - Changes in food intake and food selection in rats after 2,3,7, 8
tetrachlorodibenzo-p-dioxin (TCDD) exposure.
AB - Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on food selection were
studied in TCDD-resistant Han/Wistar and TCDD-sensitive Long-Evans rats and their
crosses. The rats were offered a selection diet consisting of chocolate, cheese,
and chow, and TCDD was given at the same time or 4 or 16 days later. TCDD
persistently reduced the chocolate intake. When the selection diet was started at
the time of or less than 11 h after TCDD exposure, TCDD almost completely
prevented the intake of chocolate and also cheese in all strains already on the
first day, while controls started to consume large amounts of both foods. This
may be due to conditioned taste aversion. The effect on food selection with
familiar foods seemed to reduce fat intake, while protein and carbohydrate
intakes were more variable. There were no major strain differences in the
chocolate intake inhibition despite a 1000-fold sensitivity difference in TCDD
lethality.
PMID- 10683478
TI - Test conditions influence the response to a drug challenge in rodents.
AB - These studies were conducted to examine the differential response to a drug
challenge under varied experimental test conditions routinely employed to study
drug-induced behavioral and neurophysiological responses in rodents. Apomorphine,
a nonselective dopamine agonist, was selected due to its biphasic behavioral
effects, its ability to induce hypothermia, and to produce distinct changes to
dopamine turnover in the rodent brain. From such experiments there is evidence
that characterization and detection of apomorphine-induced activity in rodents
critically depends upon the test conditions employed. In rats, detection of
apomorphine-induced hyperactivity was facilitated by a period of acclimatization
to the test conditions. Moreover, test conditions can impact upon other
physiological responses to apomorphine such as drug-induced hypothermia. In mice,
apomorphine produced qualitatively different responses under novel conditions
when compared to those behaviors elicited in the home test cage. Drug-induced
gross activity counts were increased in the novel exploratory box only, while
measures of stereotypic behavior were similar in both. By contrast, apomorphine
induced locomotion was more prominent in the novel exploratory box. Dopamine
turnover ratios (DOPAC:DA and HVA:DA) were found to be lower in those animals
exposed to the exploratory box when compared to their home cage counterparts.
However, apomorphine-induced reductions in striatal dopamine turnover were
detected in both novel and home cage environments. The implications of these
findings are discussed with particular emphasis upon conducting
psychopharmacological challenge tests in rodents.
PMID- 10683479
TI - Reinforcing and neurochemical effects of cocaine: differences among C57, DBA, and
129 mice.
AB - C57BL/6J, DBA/2J, and 129/OlaHsd mice were compared as to their propensity to
self-administer cocaine, the ability of cocaine injection to prevent extinction
of nose poking in the absence of cocaine infusion, and cocaine's effect on NGFI-A
and secretogranin II mRNA. Baseline nose-poke activity tended to be highest in
C57 and lowest in DBA mice. C57 and DBA mice self-administered cocaine, as
indicated by more frequent nose pokes in mice allowed to infuse cocaine through
nose pokes than in mice passively receiving the same amount of cocaine. DBA mice
had the larger ratio between active and yoked-control animals, but the response
rate in DBA mice was four times lower, and cocaine intake 10 times lower than in
C57 mice. The 129 mice showed little response to cocaine. C57 and DBA mice that
had been self-administering cocaine showed an extinction of responding when
infusions were stopped, preventable by IP cocaine (5 mg kg(-)(1)). A single
cocaine injection (2 mg kg(-)(1)) increased NGFI-A mRNA and decreased
secretogranin II mRNA in the caudate putamen in C57 mice. These effects were more
widespread in DBA and absent in the 129 mice. The marked differences among mouse
strains described here will be important to consider when transgenic mice are to
be used in cocaine-related studies.
PMID- 10683480
TI - Time-dependent alterations in ICSS thresholds associated with repeated
amphetamine administrations.
AB - The time interval between successive injections of psychostimulant drugs, such as
amphetamine, plays an important role in the development of neuroadaptive
responses to these drugs. Changes in reward function were quantified using a
discrete-trial current-intensity paradigm to determine thresholds for lateral
hypothalamic electrical self-stimulation after experimenter-administered
amphetamine injections (4 mg/kg, IP) at 1- and 5-day intervals. Repeated
administration of amphetamine produced progressive changes in ICSS behavior that
were dependent on the time interval between injections. The acute effects of
amphetamine on ICSS thresholds were potentiated, and threshold elevations
associated with withdrawal from the drug diminished after repeated drug
challenges at 5-day intervals. By contrast, daily injections of the same dose of
amphetamine did not alter the acute threshold-lowering effect of the drug, but
resulted in progressive increments in thresholds at later time points. Notably,
the decreases in response latency produce by acute amphetamine administration
were potentiated by both exposure regimens, which indicates a dissociation of
drug effects on motor performance and brain stimulation reward. Thus, the
distinct components of changes in reward function associated with acute
amphetamine administration and subsequent withdrawal were differentially altered
by the two exposure regimens, suggesting that the pattern of exposure is an
important determinant of neuroadaptive responses to the drug.
PMID- 10683481
TI - Differences in drug-induced place conditioning between BALB/c and C57Bl/6 mice.
AB - The influence of genotype on the rewarding effects of morphine (0, 1, 3, and 9
mg/kg), amphetamine (0, 0.5, 1, and 2 mg/kg), and cocaine (0, 2.5, 5, and 10
mg/kg) was examined in a place-conditioning paradigm. Two strains of mice, the
BALB/cByJIco and the C57BL/6JIco, were used, notably because of their high
difference in novelty-seeking behavior. Indeed, high novelty seeking has been
associated with an increased risk for using drugs of abuse. Results clearly show
that C57BL/6 mice display a conditioned place preference for stimuli paired with
morphine, amphetamine, or cocaine. In contrast, BALB/c mice demonstrated place
preference to morphine and place aversion to amphetamine, while cocaine was
ineffective at the doses tested. No treatment induced differences in the
locomotion measured in a drug-free condition. Results may be related to
differences at the behavioral (difference in novelty seeking) or neurochemical
level (differences in catecholaminergic or opioidergic neurotransmission).
PMID- 10683482
TI - The protective effects of PBN against MPTP toxicity are independent of hydroxyl
radical trapping.
AB - To study the mechanism of the protective effect of the spin-trapping agent alpha
phenyl-N-tert-butyl nitrone (PBN) against MPTP (1-methyl-4-phenyl-1,2,3,6
tetrahydropyridine) toxicity hydroxyl radicals and functional parameters of
neuroprotection were determined. C57BL/6 mice received PBN (100 mg/kg IP) over a
time period of 15 days and on day 8 MPTP (40 mg/kg SC). On day 15 striatal levels
of dopamine, serotonin, and metabolites were analyzed. For radical determination
mice received a single injection of salicylic acid (SA) (100 mg/kg IP) in the
time period of 0.5 h before to 72 h after MPTP injection. In vivo maximum
hydroxyl radical levels indicated by 2,3-dihydroxybenzoic acid/SA ratios were
obtained 4 h after MPTP injection, and were not affected by PBN treatment.
However, the MPTP-induced mortality, reduction of locomotor activity, continuous
loss of body weight, and striatal dopamine depletion were significantly less
pronounced in PBN-treated animals. These results elucidate the time course of
hydroxyl free radical formation in MPTP toxicity. PBN improved the functional
parameters of neuroprotection against MPTP toxicity, but there is no evidence for
hydroxyl radical scavenging properties to this effect.
PMID- 10683483
TI - Similar effects of D(1)/D(2) receptor blockade on feeding and locomotor behavior.
AB - Recent evidence suggests an important relationship between dopamine (DA)
modulation of feeding and locomotor activity. To investigate this relationship,
the free-feeding and locomotor behavior of rats under the influence of D(1)/D(2)
antagonist cis-flupenthixol was examined. DA antagonists are known to produce
within-session declines in reinforced behavior, with behavioral suppression
occurring only after a number of normal responses have been emitted. In the
present study, cis-flupenthixol (0.30 mg/kg ) produced a within-session decrement
in both free-feeding behavior and in locomotor/exploratory activity of animals in
an environment that had never been paired with food. In addition to producing
similar patterns of disruption in feeding and locomotion, the drug also produced
a similar magnitude of suppression in the two behaviors. The results show that
disruption of DA activity suppresses locomotor/exploratory activity in a manner
that closely mirrors neuroleptic suppression of feeding. Although neuroleptic
induced suppression of locomotion and feeding are traditionally presumed to
reflect an attenuation of DA motor and reward functions, respectively, the
present results suggest that DA plays a similar role in the modulation of these
two behaviors.
PMID- 10683484
TI - Sustained behavioral stimulation following selective activation of group I
metabotropic glutamate receptors in rat striatum.
AB - Group I metabotropic glutamate receptors (mGluRs) are densely expressed in the
medium-sized spiny projection neurons of striatum. Activation of this group of
the mGluRs modifies neuronal physiology through stimulation of phosphoinositide
hydrolysis and intracellular Ca(2)+ release. Unlike the ionotropic glutamate
receptors that mediate rapid synaptic transmission, activation of the mGluRs
produces long-lasting actions brought about by modulation of activities of
intracellular effectors. In this study, the role of the group I mGluRs in the
modulation of extrapyramidal motor function was examined using a group I
selective agonist, 3, 5-dihydroxyphenylglycine (DHPG), in chronically cannulated
rats. Bilateral injections of DHPG at a series of subtoxic doses (20, 40, 80, and
160 nmol) into the central part of the dorsal striatum produced hyperlocomotion
and a unique stereotypical behavior (spontaneous and repetitive twitching
movement of the head and forepaws) in a dose-dependent manner. The characteristic
twitchy behavior usually commenced 30 min to 1 h, and could last as long as 10 to
12 h, after a single injection of the group I agonist. The behavioral responses
to DHPG administration were markedly antagonized by intrastriatal injection of
the group I antagonist PHCCC (10 nmol), but not the group II/III antagonist
MSOPPE (10 nmol). Intrastriatal administration of 20 nmol dantrolene, an
inhibitor of intracellular Ca(2)+ mobilization, also prevented DHPG-stimulated
motor activities. However, blockade of dopamine D(1) receptors with systemic
administration of SCH-23390 (0.1 mg/kg, SC) did not alter the ability of DHPG to
provoke behavioral activities. These data indicate that selective activation of
the DHPG-sensitive group I mGluRs in the striatum can produce long-lasting
stimulation of motor activity. DHPG-induced motor stimulation involves the
mobilization of intracellular Ca(2)+ stores, but appears to be independent of
D(1) dopaminergic transmission.
PMID- 10683485
TI - Ontogeny of phencyclidine and apomorphine-induced startle gating deficits in
rats.
AB - NMDA antagonists and dopamine (DA) agonists produce neuropathological and/or
behavioral changes in rats that may model specific abnormalities in schizophrenia
patients. In adult rats, NMDA antagonists and DA agonists disrupt sensorimotor
gating-measured by prepulse inhibition (PPI)-modeling PPI deficits in
schizophrenia patients. In addition, high doses of NMDA antagonists produce
limbic system pathology that may model neuropathology in schizophrenia patients.
We examined these behavioral and neuropathological models across development in
rats. Both the NMDA antagonist phencyclidine (PCP) and the DA agonist apomorphine
disrupted PPI in 16 day pups, demonstrating early developmental functionality in
substrates regulating these drug effects on PPI. In contrast, PCP neurotoxicity
was evident only in adult rats. Brain mechanisms responsible for the PCP
disruption of PPI, and PCP-induced neurotoxicity, are dissociable across
development.
PMID- 10683486
TI - PD-135,158, a cholecystokinin(B) antagonist, enhances latent inhibition in the
rat.
AB - The antipsychotic potential of cholecystokinin (CCK)-related compounds stems from
CCK's colocalization with dopamine (DA). CCK demonstrates excitatory and
inhibitory effects on DA in the mesolimbic pathway. Such diverse actions might be
mediated by different receptor subtypes (CCK(A) or CCK(B)). Multiple hypotheses
have emerged regarding the clinical application of CCK-based drugs. Administering
selective nonpeptide antagonists within animal models relevant to schizophrenia
would help delineate CCK receptor involvement. One animal model simulating a
cognitive dysfunction of schizophrenia is latent inhibition (LI). An animal
repeatedly exposed to a stimulus that is devoid of consequence is subsequently
inhibited in making new associations with that stimulus. This reflects a process
of learning to ignore irrelevant stimuli. The present study examined the effects
of the selective CCK(B) antagonist PD-135,158 (0.001, 0. 01, and 0.1 mg/kg) using
a conditioned suppression of drinking procedure in rats. For purposes of
comparison the effects of haloperidol (0.1 mg/kg) were also investigated. PD
135,158 (0.1 mg/kg), similar to haloperidol (0.1 mg/kg), elicited a clear LI
effect under conditions that did not lead to LI in control rats (low number of
preexposures). These findings highlight the antipsychotic potential of CCK(B)
antagonists, and further illustrate the LI paradigm's capacity to detect novel,
antipsychotic-like, drug activity.
PMID- 10683487
TI - Anxiolytic-like effects of meprobamate. Interactions with an opiate antagonist in
Swiss and BALB/c mice.
AB - Naloxone has previously been shown to block the effects of benzodiazepines in the
Swiss but not in the BALB/c strain. We have also reported that naloxone
potentiates subeffective doses of benzodiazepines in Swiss mice. In the present
studies we first determined whether naloxone could block anxiolytic-like effects
of meprobamate in Swiss and BALB/c mice. Then we evaluated if subeffective doses
of meprobamate could be potentiated in Swiss as well as in BALB/c mice. The
elevated plus-maze test and the light/dark choice procedure were used. The lowest
dose of meprobamate with anxiolytic-like effects was 60 mg/kg in the BALB/c mice.
This dose was effective in both the plus-maze and in the light/dark choice
procedure. In Swiss mice the same dose was effective in the plus-maze, whereas
120 mg/kg was required in the light/dark choice procedure. When an effective dose
of meprobamate was combined with naloxone, 10 mg/kg, no blockade of anxiolytic
like effects was obtained in any strain in any procedure. To the contrary, when a
subeffective dose of meprobamate was combined with naloxone, 10 mg/kg, an
anxiolytic-like effect was obtained in both strains in both procedures. The
present series of experiment shows that the ability of naloxone to block
anxiolytic-like drug effects do not apply to meprobamate. However, the naloxone
induced potentiation of subeffective doses previously observed after treatment
with benzodiazepines or buspirone was present also after treatment with
meprobamate. Moreover, although blockade of anxiolytic-like drug effects with
naloxone has not been observed in BALB/c mice, potentiation was as evident in
that strain as in the Swiss. This suggests that the mechanisms behind naloxone's
blockade of anxiolytic-like effects are independent from those behind its
potentiation of such effects.
PMID- 10683488
TI - Benzodiazepine receptor affinities, behavioral, and anticonvulsant activity of 2
aryl-2,5-dihydropyridazino[4,3-b]indol- 3(3H)-ones in mice.
AB - The anticonvulsant properties of 1,4-benzodiazepines (BDZs), pyrazoloquinolones
(CGS), 2-aryl-2,5-dihydropyridazino[4, 3-b]indol-3(3H)-ones (PIs) 1 1i 1d 1f 1e
1b 1c 1h, and 1a, the latter being inactive against audiogenic seizures. Some PIs
1 and abecarnil showed anticonvulsant properties against seizures induced by PTZ
with a potency lower than that observed in audiogenic seizures. The
pharmacological actions of 1d, 1f, and 1i were significantly reduced by a
treatment with flumazenil (8.24 micromol/kg IP), suggesting a clear involvement
of benzodiazepine mechanisms in the anticonvulsant activity of these compounds or
their metabolites. The anticonvulsant activity of 1d, 1f, and 1i was also
evaluated against seizures induced by two beta-carbolines namely methyl-beta
carboline-3-carboxylate (beta-CCM) and methyl-6, 7-dimethoxy-4-ethyl-beta
carboline-3-carboxylate (DMCM), in DBA/2 mice: they gave better protection
against seizures induced by beta-CCM than the ones by DMCM. The potency of
various BDZs and PIs as inhibitors of specific [3H]flumazenil binding to neuronal
membranes, was also evaluated. The radioligand binding study, carried out on
stable cell lines expressing definite combinations of benzodiazepine receptor
subunits, demonstrated that 1b, 1e, 1d, and 1h have preferential interaction with
alpha(1), beta(3), gamma(2), receptor subtypes.
PMID- 10683489
TI - Heroin-specific stimuli reinstate operant heroin-seeking behavior in rats after
prolonged extinction.
AB - The clinical literature suggests that exposure to environmental stimuli
previously associated with heroin availability may precipitate relapse. However,
experimental studies elucidating the significance of learned associations between
drug availability and reinstatement of heroin-seeking behavior in the rat are
still scarce. To examine the role of environmental stimuli in reinstatement of
heroin-seeking behavior, rats were trained to associate discriminative stimuli
(DS+) with intravenous heroin availability vs. nonreward [i.e., availability of
intravenous saline (DS-)]. The animals then were subjected to extinction training
during which the discriminative stimuli were not presented, and lever pressing
did not result in drug or saline infusion. The resistance to extinction varied
greatly among animals (2.5-11.4 weeks). When the discriminative stimuli were
reintroduced, the DS+ reinstated responding while the DS- did not. The average
number of responses for heroin during the reinstatement trial (12.8) paralleled
the average responding for heroin during discrimination training (12.6),
suggesting that the associations between environmental stimuli and drug
availability are long-lasting and powerful motivators of drug-seeking behavior.
PMID- 10683490
TI - Circadian rhythm-dependent development of melatonin effects and tolerance to PHNO
in rats.
AB - Male Sprague-Dawley rats were given 12 days of continuous infusions of (+)-4
propyl-9-hyroxynapthoxazine (PHNO, 5microg/h), a highly selective dopamine D(2)
receptor agonist, via subcutaneous ALZET((R)) osmotic pumps. Motor stimulant
effects (locomotion and rearing) were monitored throughout the treatment period,
including after the animals were injected with 2-iodo-melatonin (0.5 mg/kg) on
days 8-10 and 13 after initiation of PHNO infusions. The rats (maintained on 12
L:12 D cycle) developed tolerance to the motor stimulant effects of PHNO during
the day, and behavioral sensitization to PHNO during the night. Arousing rats
with a vehicle injection transiently blocked the daytime tolerance. A more
sustained environmental noise without handling of animals, which had a stronger
effect on increasing motor activity of control rats, reversed tolerance to
sensitization. Therefore, graded levels of arousal produce graded increases in
motor activity in rats otherwise tolerant to the effects of PHNO. Daytime
tolerance to PHNO was reversed to sensitization by 2-iodo-melatonin. This effect
was more than an additive effect of drug + injection procedure stress. The
differential development of nocturnal sensitization and diurnal tolerance to PHNO
effects on motor activity may depend upon circadian rhythms in melatonin release,
as well as on state of arousal.
PMID- 10683491
TI - Effects of ropinirole on various parkinsonian models in mice, rats, and
cynomolgus monkeys.
AB - Ropinirole (4-[2-(dipropylamino)ethyl]-2-indolinone monohydrochloride) a
nonergoline dopamine receptor agonist with high affinity for native dopamine D(2)
like receptors in human caudate tissue, was tested with respect to the
stimulation of postsynaptic brain dopamine receptors in standard preclinical
models of Parkinson's disease. Additionally, in these animal models the
antiparkinsonian activity of ropinirole was compared to that of bromocriptine.
The ED(50)s (95% confidence limits) of ropinirole and bromocriptine on the
turning behavior in 6-OHDA-lesioned rats were 20.17 mg/kg (14.27-26.88 mg/kg) and
11.99 mg/kg (9.37-14.17 mg/kg), respectively. The ED(50)s (95% confidence limits)
of ropinirole and bromocriptine on the catalepsy induced by reserpine were 18.55
mg/kg (15.29-22.99 mg/kg) and 12.56 mg/kg (10.25-14.64 mg/kg), respectively.
Ropinirole and bromocriptine had no effect on the tremors induced by oxotremorine
in mice, whereas atropine markedly suppressed the tremors. The ED(50)s (95%
confidence limits) of ropinirole and bromocriptine on the tremors in VMT-lesioned
monkeys were 0.18 mg/kg (0.12-0.29 mg/kg) and 2.63 mg/kg (1.06-6.45 mg/kg),
respectively. In rodent parkinsonian models, bromocriptine was more potent than
ropinirole; however, in the nonhuman primate parkinsonian model, ropinirole was a
more potent inhibitor of parkinsonian activity than bromocriptine. This study
suggests that ropinirole is a dopamine D(2)-like receptor agonistic drug of
potential use in the treatment of Parkinson's disease.
PMID- 10683492
TI - Individual differences in pavlovian autoshaping of lever pressing in rats predict
stress-induced corticosterone release and mesolimbic levels of monoamines.
AB - Pavlovian autoshaping CRs are directed and reflexive consummatory responses
targeted at objects repeatedly paired with rewarding substances. To evaluate the
hypothesis that autoshaping may provide an animal learning model of vulnerability
to drug abuse, this study relates individual differences in lever-press
autoshaping CR performance in rats to stress-induced corticosterone release and
tissue monoamine levels in the mesolimbic dopamine tract. Long-Evans rats (n =
14) were given 20 sessions of Pavlovian autoshaping training wherein the
insertion of a retractable lever CS was followed by the response-independent
presentation of food US. Large between-subjects differences in lever-press
autoshaping CR performance were observed, with group high CR frequency (n = 5)
performing many more lever press CRs than group low CR frequency (n = 9). Tail
blood samples were obtained before and after the 20th autoshaping session, then
24 h later the rats were sacrificed and dissection yielded tissue samples of
nucleus accumbens (NAC), prefrontal cortex (PFC), caudate putamen (CP), and
ventral tegmental area (VTA). Serum levels of postsession corticosterone were
elevated in group high CR frequency. HPLC revealed that group high CR frequency
had higher tissue levels of dopamine and DOPAC in NAC, lower levels of DOPAC/DA
turnover in CP, and lower levels of 5-HIAA and lower 5-HIAA/5-HT turnover in VTA.
The neurochemical profile of rats that perform more autoshaping CRs share some
features of vulnerability to drug abuse.
PMID- 10683493
TI - Learning and memory in mice treated with choline oxidase, a hydrolytic enzyme for
choline.
AB - Learning and maintenance of memory in mice intraperitoneally (IP) injected with
choline oxidase (ChO, 6 units/g), a hydrolytic enzyme for choline (Ch), were
assessed by means of a step-through passive-avoidance task. The ChO treatment
induced a hydrolysis of free Ch in plasma, which in turn, induced a decrease in
cerebral acetylcholine (ACh) release. In the learning test, the ChO-treated mice
showed significant inhibition to learn the avoidance from electric shock. In the
retention test, the impairment of the memory once established was not produced by
posttreated ChO. We concluded that the decreased cerebral cholinergic
neurotransmission induced by ChO retarded acquisition of passive-avoidance
learning more readily than the maintenance of memory.
PMID- 10683494
TI - Quantification of S-adenosylmethionine-induced tremors: a possible tremor model
for Parkinson's disease.
AB - Tremor is the most visible symptom of Parkinson's Disease (PD), and should be the
appropriate parameter in models for its evaluation. Lack of reliable PD tremor
models and methods to distinguish tremors from nontremor movements means that
nontremor behavior such as rotation following basal ganglia damage are mostly
used. Our laboratory has shown that S-adenosyl-methionine (SAM) injections into
the brain of rats reliably produced tremors, rigidity, hypokinesia, and abnormal
posture. Thus, SAM-induced tremors, when distinguished from nontremor activities,
has the potential as a model for testing anti-PD agents. Tremor Monitor-recorded
activity profiles of the rats injected with SAM showed low-amplitude signals
interlaced with high-amplitude bursts of tremor episodes. Control activities were
of low-medium amplitudes with no such patterns. The number of real and apparent
episodes detected over 20 min were 92 +/- 12 and 84 +/- 14 lasting 470 +/- 50 and
210 +/- 50 s, indicating mean durations of 5.1, and 2.4 s, frequencies of 12 +/-
0.1 and 11 +/- 0.2 Hz, cycles (waves) per episode of 54 +/- 6 and 19 +/- 2 and
amplitudes of 42.3 +/- 5 and 19.8 +/- 1 for the SAM-treated and control rats,
respectively. The nontremor activities of rats injected with phosphate-buffered
saline were distinguished and eliminated by raising the minimum amplitude and
number of cycles to 20. This procedure is being enhanced for screening antitremor
agents and for elucidating the possible mechanism for Parkinsonism.
PMID- 10683495
TI - Lack of evidence for a role of serotonin in interleukin-1-induced hypophagia.
AB - Interleukin-1 (IL-1) administration depresses food intake in rodents. IL-1 is
known to increase the metabolism of serotonin, which is known to affect feeding
behavior. Thus, serotonin is an obvious candidate for a mediator of the
hypophagic response to IL-1. Therefore, we tested the ability of serotonergic
agonists and antagonists to alter the hypophagic responses to IL-1 and bacterial
lipopolysaccharide (LPS). Hypophagia was assessed in ad lib-fed mice by recording
the intake of sweetened milk in a 30-min period. Acute intraperitoneal
administration of mouse IL-1beta reliably decreased milk intake. This hypophagic
response was not affected by any of the serotonin antagonists tested, including 5
HT(1A) (WAY100135 and propranolol), 5-HT(1B) (GR127935), 5-HT(2) (ritanserin,
ketanserin, SB206553, and RS102221), mixed 5-HT(1/2) (methysergide and
metergoline), and 5-HT(3) (tropisetron) receptor antagonists. The 5-HT(1A)
agonists (8-OH-DPAT and ipsapirone) and a 5-HT(1B) agonist (CGS12066B) known to
decrease the activity of serotonergic neurons, also had no effect. Mice
pretreated with 5,7-dihydroxytryptamine to deplete brain serotonin ate less, but,
nevertheless, displayed similar hypophagic responses to mIL-1beta or LPS. The
results suggest that serotonin is not involved in the decrease in short-term milk
intake induced by mIL-1beta or LPS in mice that have been fed ad lib.
PMID- 10683496
TI - Diazepam has no beneficial effects on stress-induced behavioural and endocrine
changes in male tree shrews.
AB - The present study evaluated the effect of subchronic oral treatment of
psychosocially stressed male tree shrews with diazepam on locomotor activity,
marking behavior, avoidance behavior, and urinary cortisol and noradrenaline. To
mimic a realistic situation of anxiolytic intervention, the treatment started 14
days after the beginning of psychosocial stress; at that time, the stress-induced
behavioral and endocrine alterations had been established. The drug (5 mg/kg/day)
was administered orally in the morning, while the psychosocial stress continued
during the whole treatment period; the therapeutic action of diazepam treatment
was followed across 7 days. Twenty-four hours after the last application serum
concentrations of diazepam and its major metabolites were determined via HPLC.
The results revealed concentrations of 7 ng/ml for diazepam, 106 ng/ml for
nordiazepam, 22 ng/ml for temazepam, and 30 ng/ml for oxazepam. Treatment of
subordinate animals with diazepam did not reveal a beneficial effect to any of
the parameters studied. This contrasts to earlier findings showing that the
behavioral and neuroendocrine alterations produced by this stress paradigm are
sensitive to chronic treatment with the tricyclic antidepressant clomipramine.
The present results support the view that in male tree shrews the state induced
by psychosocial stress might be more depression related than anxiety related.
PMID- 10683497
TI - Behavioral and neurochemical alterations after lithium-pilocarpine administration
in young and adult rats: a comparative study.
AB - Pilocarpine and lithium-pilocarpine can induce seizures and brain damage in adult
rats. However, manifestation of cerebral lesions seems to be an age-related
phenomenon suggesting that maturational states of neurocircuitry may be involved.
We have studied behavior changes, cerebral histopathology, and muscarinic and
dopaminergic receptors density in rodents subjected to lithium-pilocarpine
treatment. Wistar rats, at two different ages (21 days and 2 months), were
treated with pilocarpine (15 mg/kg, SC), lithium (3 mEq/kg, IP), atropine (50
mg/kg, IP) and the combination of lithium to pilocarpine. Histopathologic studies
showed that younger animals were more resistant to the development of cerebral
changes and there was a preferential involvement of the striatum (Wilcoxon p =
0.02) as opposed to more generalized areas in adult animals such as hippocampus
and neocortex. Lithium treatment induced an upregulation of muscarinic receptors
at both ages, and this effect was reversed in younger animals after pilocarpine
administration. Lithium also induced an upregulation of dopaminergic receptors in
the striatum at both ages (p < 0.05), and this effect was not reversed after
pilocarpine administration. Our data confirm that young animals show less brain
damage after lithium-pilocarpine, and main alterations in dopaminergic receptors
density occur in young and older animals after treatment with lithium and lithium
combined to a low dose of pilocarpine.
PMID- 10683498
TI - Long-term functional end points following middle cerebral artery occlusion in the
rat.
AB - The purpose of the present study was to assess the magnitude and stability of a
number of functional deficits in rats subjected to occlusion of the middle
cerebral artery (MCAO). Three groups of rats, treated with 90-min, 120-min, or
sham occlusion were used in functional studies for 22 weeks following surgery.
The following tests were used: methamphetamine-induced rotation, the staircase
test, acquisition of operant responding, running-wheel behavior, and performance
of operant differential reinforcement of a low-rate responding (DRL) schedule of
reinforcement. Histology performed at 23 weeks following infarct showed on
average modest damage of a 19% reduction in hemispheric volume. Of the behavioral
tests conducted, rotation, the staircase test, and the operant DRL were sensitive
to ischemic damage, and were under some circumstances related to lesion size.
These data show that long-term functional deficits following MCAO are
demonstrable, and hence, assessment of long-term neuroprotection is feasible.
PMID- 10683499
TI - Fentanyl self-administration in juvenile rats that were tolerant and dependent to
fentanyl as infants.
AB - Human neonates and infants can become tolerant and dependent during continuous
fentanyl or morphine administration. The long-term consequences in these
individuals as juveniles and adults are unknown. This study compared fentanyl
self-administration behavior in juvenile rats that were opioid naive or were
exposed chronically to fentanyl as infants. Postnatal day 14 infant rats remained
naive or were implanted with saline- or fentanyl-filled Alzet minipumps. After 72
h, fentanyl's antinociceptive potency was 3.0-fold lower in the fentanyl-infused
rats. Naloxone precipitated withdrawal occurred only in the fentanyl-infused
animals. Other similarly treated infant rats were allowed to mature into P42
juvenile rats before enrolling them in an oral fentanyl self-administration
study. Rats from each group consumed significantly more fentanyl than quinine.
However, those rats, tolerant and dependent to fentanyl as infants, did not self
administer more fentanyl than their opiate-naive littermates. The issue of
whether fentanyl was consumed for its reinforcing properties was demonstrated
when noncontingent administration of opiate antagonists significantly reduced
fentanyl intake in another group of juvenile rats. These data indicate that
fentanyl is consumed for its reinforcing properties, but that infant fentanyl
tolerance and dependence did not predispose them to self-administer more fentanyl
than opiate-naive animals.
PMID- 10683500
TI - Medial prefrontal cortex acetylcholine injection-induced hypotension: the role of
hindlimb vasodilation.
AB - The injection of acetylcholine (ACh) into the cingulate region of the medial
prefrontal cortex (MPFC) causes a marked fall in arterial blood pressure which is
not accompanied by changes in heart rate. The purpose of the present study was to
investigate the hemodynamic basis for this stimulus-induced hypotension in
Sprague-Dawley rats. The study was designed to determine whether a change in the
vascular resistance of hindlimb, renal or mesenteric vascular beds contributes to
the fall in arterial pressure in response to ACh injection into the cingulate
cortex. Miniature pulsed-Doppler flow probes were used to measure changes in
regional blood flow and vascular resistance. The results indicated that the
hypotensive response was largely due to a consistent and marked vasodilation in
the hindlimb vascular bed. On this basis, an additional experiment was then
undertaken to determine the mechanisms that contribute to hindlimb vasodilation.
The effect of interrupting the autonomic innervation of one leg on the hindlimb
vasodilator response was tested. Unilateral transection of the lumbar sympathetic
chain attenuated the cingulate ACh-induced vasodilation in the ipsilateral, but
not in the contralateral hindlimb. These results suggest that the hypotensive
response to cingulate cortex-ACh injection is caused by skeletal muscle
vasodilation mediated by a sympathetic chain-related vasodilator system.
PMID- 10683501
TI - Vagal innervation of the rat duodenum.
AB - Electrophysiologic and anterograde tract tracing studies have demonstrated that
the vagus nerve innervates the duodenum. These studies, however, have provided
little information regarding the finer anatomic topography within the vagal
complex. In this study, the retrograde neuronal tracers WGA-HRP or DiI, applied
to the duodenum, were used to characterize the vagal afferent and efferent
innervation of this portion of the gastrointestinal tract. This approach labeled
a substantial number of motor neurons in both the medial and lateral columns of
the dorsal motor nucleus of the vagus (DMNV). Vagal motor neurons innervating the
duodenum were seen across the medial-lateral extent of the DMNV and between 600
microm rostral to obex and 1600 microm caudal to obex. The three branches of the
vagus nerve contained efferent fibers to the duodenum. The gastric branch of the
vagus nerve was the pathway that connected the majority of DMNV neurons with the
duodenum. These neurons were located in the medial and middle thirds of the DMNV.
The celiac branch to the duodenum was composed of axons from the majority of
lateral column neurons but also contained axons from neurons in the medial
column. The hepatic branch of the vagus nerve contained only a small number of
cell axons. Some neurons were located medially whereas others were in the lateral
third of the duodenum. Although central terminations of vagal primary afferents
from the duodenum were not found in previous tract tracing studies, we observed a
large number of terminals in the subpostremal/commissural region of the nucleus
of the solitary tract. Similar to the motor fibers, most afferent fibers from the
duodenum were located in the gastric branch of the vagus nerve, although the
hepatic and celiac branches also contained afferent neurons. These results
demonstrate that the vagal innervation of the duodenum is unique, being an
amalgam of what would be expected following labeling of more proximal and distal
portions of the GI tract. The uniqueness of the sensory and motor innervation to
the duodenum has implications for hypotheses regarding the organization of
vagovagal reflexes controlling gastrointestinal function.
PMID- 10683502
TI - The role of NGF in pregnancy-induced degeneration and regeneration of sympathetic
nerves in the guinea pig uterus.
AB - In the guinea pig, pregnancy is associated with a generalised depletion of
noradrenaline in uterine sympathetic nerves and, in the areas of the uterus
surrounding the foetus, by a complete degeneration of sympathetic nerve fibres.
These pregnancy-induced changes have been interpreted as a selective effect of
placental hormones on the system of short sympathetic fibres arising from the
paracervical ganglia. An alternative explanation is that pregnancy affects the
neurotrophic capacity of the uterus. We measured NGF-protein levels in the guinea
pig uterine horn, tubal end and cervix at early pregnancy, late pregnancy and
early postpartum, using a two-site enzyme-linked immunosorbent assay. For
comparative purposes the distribution and relative density of noradrenaline
containing sympathetic nerve fibres were assessed histochemically, and tissue
levels of noradrenaline were measured biochemically, using high-performance
liquid chromatography with electrochemical detection. In all the uterine regions
analysed, NGF-protein levels showed a decline at term pregnancy, but in no case
was this change statistically significant. After delivery, NGF-protein levels
showed a marked increase in the cervix as well as in both the fertile and empty
horns. These results suggest that alterations in NGF-protein do not account for
the impairment of uterine sympathetic innervation during pregnancy, but may
contribute to their recovery after delivery.
PMID- 10683503
TI - The gain of the baroreflex bradycardia is reduced by microinjection of NMDA
receptor antagonists into the nucleus tractus solitarii of awake rats.
AB - The baroreflex activation with phenylephrine infusion produces a bradycardic
response. In the present study, the role of NMDA receptors in the nucleus tractus
solitarii (NTS) in the processing of the parasympathetic component of the
baroreflex was evaluated using acid phosphonivaleric (AP-5), a selective NMDA
receptor antagonist. Baroreflex activation was performed before and after
bilateral microinjection of AP-5 into the intermediate commissural NTS (0.5 mm
lateral to the midline). Microinjection of the vehicle (saline, 0.9%) or a dose
of 2 nmol/50 nl of AP-5 into the NTS produced no effect on the gain of the
baroreflex while a dose of 10 nmol/50 nl of AP-5 produced a significant reduction
in the gain of the baroreflex 2 min after microinjection [-1.43+/-0.22 vs. -0.
43+/-0.03 bpm/mmHg, (n=6)], with a return to control levels 10 min after the
microinjections. The dose of 10 nmol/50 nl was selective for NMDA receptors
considering that the cardiovascular responses to microinjection of AMPA (0.05
pmol/50 nl), a non-NMDA receptor agonist, were not affected by this dose of AP-5
and the responses to microinjection of NMDA (2 nmol/50 nl) were blocked. The data
show that the bradycardic response to baroreflex activation was blocked by AP-5
microinjected into the NTS, indicating that the neurotransmission of the
parasympathetic component of the baroreflex is mediated by NMDA receptors in the
NTS.
PMID- 10683504
TI - Effects of superoxide generating systems on muscle tone, cholinergic and NANC
responses in cat airway.
AB - To study the possible role of reactive oxygen species in airway hyperreactivity,
we examined the effects of the superoxide anion radical (O(2)(-)) generating
systems, pyrogallol and xanthine with xanthine oxidase, on muscle tone,
excitatory and inhibitory neurotransmission in the cat airway. Smooth muscle
contraction or non-adrenergic non-cholinergic (NANC) relaxation evoked by
electrical field stimulation (EFS) were measured before or after O(2)(-)
generating systems with or without diethydithiocarbamic acid (DEDTCA), an
inhibitor of endogenous superoxide dismutase (SOD). Resting membrane potential or
excitatory junction potential (EJP) were also measured in vitro. Both pyrogallol
and xanthine/xanthine oxidase produced biphasic changes in basal and elevated (by
5-HT) muscle tone. After SOD pretreatment, both systems consistently produced a
prolonged contraction, thereby indicating that O(2)(-) was converted to H(2)O(2)
by the action of SOD and as a result the actions of O(2)(-) were lost but those
of H(2)O(2) introduced. The O(2)(-) showed no significant effect on smooth muscle
contraction or EJP evoked by EFS, however after DEDTCA pretreatment, it evoked
initial enhancement followed by suppression of the contraction and EJP. DEDTCA
pretreatment ameliorated the inhibitory action of pyrogallol and
xanthine/xanthine oxidase on the NANC relaxation, probably because O(2)(-) could
combine with endogenous NO to form peroxynitrite. These results indicate that the
O(2)(-) generating systems have multiple actions, presumably due to the presence
and simultaneous action of at least two different reactive oxygen species (O(2)(
) and H(2)O(2)). While H(2)O(2) seems to be responsible for elevation of muscle
tone and augmentation of smooth muscle contraction by EFS, O(2)(-) inhibits
muscle tone, cholinergic and NANC neurotransmission.
PMID- 10683505
TI - Inhibitory neural pathway regulating gastric emptying in rats.
AB - The relaxation of the pylorus is one of the most important factors for promoting
gastric emptying. However, the role of inhibitory neurotransmitters in the
regulation of pyloric relaxation and gastric emptying remains unclear. In this
study, we investigated the effects of NO biosynthesis inhibitor, N(G)-nitro-L
arginine methyl ester (L-NAME), and calcium dependent potassium channel blocker,
apamin, on vagal stimulation-induced pyloric relaxation and gastric emptying in
rats. Sodium nitroprusside (SNP), adenosine 5'-triphosphate (ATP), vasoactive
intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating peptide
(PACAP) caused pyloric relaxations in a dose dependent manner in vivo. Apamin
(120 microg/kg) significantly reduced ATP and PACAP-induced pyloric relaxations
without affecting SNP- or VIP-induced relaxations. Vagal stimulation (10 V, 1 ms,
1-20 Hz)-induced pyloric relaxation was significantly inhibited by L-NAME (10
mg/kg). The combined administration of L-NAME and apamin almost completely
abolished vagal stimulation-induced pyloric relaxation. L-NAME and apamin
significantly increased spontaneous contractions in the antrum, pylorus and
duodenum. Increased motility index by L-NAME and apamin was significantly higher
in the pylorus and duodenum, compared to that of antrum. L-NAME and apamin
significantly delayed liquid gastric emptying. These results suggest that besides
NO, probably ATP and PACAP, act as inhibitory neurotransmitters in the rat
pylorus and regulate gastric emptying.
PMID- 10683506
TI - Effect of sensory stimulation (acupuncture) on sympathetic and parasympathetic
activities in healthy subjects.
AB - It has been postulated that sensory stimulation (acupuncture) affects the
cardiovascular system via the autonomic nervous system. Previously, skin
temperature, thermography, plethysmography and blood pressure changes have been
used in evaluation of sympathetic nerve activity following acupuncture. By using
power spectral analysis, the low frequency and high frequency components of heart
rate variability can be calculated reflecting the sympathetic and parasympathetic
activity. The purpose of this study was to investigate to what extent acupuncture
applied into the thenar muscle and into the cavum concha of the ear induced
changes in the sympathetic and/or parasympathetic nervous system in healthy
subjects. MATERIALS AND METHODS: Twelve healthy volunteers, six men and six
women, mean age 34.4 (range 23-48) participated in three balanced, randomly
distributed sessions. At an individual initial visit the 12 volunteers were
introduced to the needle sensation by having a needle inserted into the point LI
11. The needle sensation was evoked and the subject was trained to identify the
characteristic needle sensation. The introduction was followed by three test
sessions. SESSION A: A short acupuncture needle, (Seirin no 3, ∅0.20x15
mm) was inserted perpendicular into the earpoint, Lu 1, in the left inferior hemi
conchae. SESSION B: An acupuncture needle (Hwato, ∅0.30x30 mm) was
inserted perpendicular into the Hegu point (LI 4) in the middle of the right
dorsal thenar muscle. SESSION C: An acupuncture needle (Hwato, ∅0.30x30
mm) was inserted perpendicular superficially into the skin overlying the Hegu
point on the left hand. Results. Stimulation of the ear induced a significant
increase in the parasympathetic activity during the stimulation period of 25 min
(P<0.05) and during the post-stimulation period of 60 min (P<0.05). No
significant changes were observed in either the sympathetic activity, blood
pressure or heart rate. Stimulation of the thenar muscle resulted in a
significant increase in the sympathetic and the parasympathetic activity during
the stimulation period (P<0.01) and during the post-stimulation period (P<0.01
and P<0.001, respectively). A significant decrease in the heart rate frequency
(P<0.05) at the end of the post-stimulation period was also demonstrated. The
superficial needle insertion into the skin overlaying the right thenar muscle
caused a pronounced balanced increase in both the sympathetic and parasympathetic
activity during the post stimulation period of 60 min (P<0.01) while no changes
were observed during the stimulation period. CONCLUSION: It is indicated that
sensory stimulation (acupunctura) in healthy persons is associated with changed
activity in the sympathetic and parasympathetic nervous system depending on site
of stimulation and period of observation.
PMID- 10683507
TI - Gastric and non-gastric signals in electrogastrography.
AB - Electrogastrography (EGG) is the cutaneous recording of gastric myoelectrical
activity, and the dominant frequency reflects the rhythm of the gastric slow
wave. Ambulatory EGG is contaminated with a large amount of motion artifacts, and
it is unclear how much of the signals comprising the dominant frequency
originates from non-gastric sources. The aim of the present study was to evaluate
the pattern of gastric and non-gastric signals in the dominant frequency
histogram (DFH) obtained from long-term ambulatory EGG recordings. Ten normal
controls and five post-gastrectomy patients participated in the present study.
Twenty-four hour ambulatory EGG was recorded under normal daily conditions. The
DFH of normal controls showed two distinctive peaks, and that of the post
gastrectomy patients, a single peak. The common peak at approximately 1.5 cpm was
seen in both DFHs, and the peak at 3 cpm was seen only in the DFH of normal
controls. Thus, the common peak was thought to be a product of non-gastric
origin. In conclusion, the dominant frequency consists of gastric and non-gastric
components which have a specific distribution pattern in the DFH. These findings
quantified the contribution of gastric and non-gastric signals to the dominant
frequencies in long-term ambulatory EGG.
PMID- 10683508
TI - ICAM-1 expression in autoimmune encephalitis visualized using magnetic resonance
imaging.
AB - The expression of leukocyte adhesion molecules in the intact brains of mice with
experimental autoimmune encephalitis (EAE) was visualized by Magnetic Resonance
Imaging (MRI) through the use of a new, target-specific MR contrast agent.
Antibody-conjugated paramagnetic liposomes (ACPLs) were designed to achieve in
vivo targeting of molecules expressed on vascular endothelium, while providing
sufficient signal enhancement at these sites for detection by MRI. ACPLs targeted
to intercellular adhesion molecule-1 (ICAM-1), an endothelial leukocyte receptor
upregulated on cerebral microvasculature during EAE, were administered to
diseased mice. Fluorescence microscopy confirmed that fluorescently-tagged ACPLs
were localized to central nervous system (CNS) microvasculature in a pattern
consistent with ICAM-1 upregulation described immunohistochemically. High
resolution MRI of mouse brains ex vivo demonstrated that ACPL binding conferred
significant enhancement of signal intensity (SI) as compared to control images.
These results suggest that ACPLs can be used as MRI contrast agents to visualize
specific molecules expressed on vascular endothelium during disease.
PMID- 10683509
TI - Strain specific variation in cytokine regulated ICAM-1 expression by rat brain
endothelial cells.
AB - Cytokine induced levels of ICAM-1 expressed by rat brain-endothelial cells were
quantitated by enzyme immunoassay in response to stimulation by TNF-alpha in the
presence or absence of IFN-gamma. The rat strains investigated differ in their
susceptibility to experimental allergic encephalomyelitis; significantly less
ICAM-1 was induced by BEC derived from the resistant PVG strain as compared to
the susceptible LEW strain with both cytokine combinations. In contrast, despite
the difference in disease susceptibility, equivalent levels of ICAM-1 were
induced between the LEW and BN strain. Furthermore, evidence for a synergistic
interaction of both TNF-alpha and IFN-gamma was observed in the BN strain. The
results are discussed with relevance to the disease profile of each strain.
PMID- 10683510
TI - Analysis of experimental autoimmune encephalomyelitis induced in F344 rats by
pertussis toxin administration.
AB - To elucidate the factor(s) accelerating the autoimmune disease processes, we
induced two types of experimental autoimmune encephalomyelitis (EAE), severe and
very mild, in F344 rats by immunization with myelin basic protein (MBP) plus
pertussis toxin (PT) (PT+) or with MBP alone (PT-) and compared the differences
between the two. Immunohistochemical examinations showed that although the nature
of inflammation was essentially the same between the two groups, the proportion
of Vbeta8.2(+) T cells in the CNS lesion of PT (+) rats was larger than that of
PT (-) rats. Cytokine analysis by competitive PCR revealed that IL-10 mRNA in the
lymphoid organ was significantly suppressed in the PT(+) group, whereas levels of
IFN-gamma,TNF-alpha and TGF-beta mRNA were insignificantly different after PT
administration. In addition, T cells taken from PT (+) rats proliferated well in
response to MBP, while those from PT (-) rats showed a marginal response to the
same antigen. However, this finding does not indicate the switching of non
encephalitogenic to encephalitogenic T cells upon PT administration because PT (
) rats contained encephalitogenic T cells and/or their precursor cells as
revealed by adoptive transfer experiments. Taken together, these findings suggest
that suppression of IL-10 by PT administration is the major factor contributing
to the exacerbation of EAE in PT(+) rats.
PMID- 10683511
TI - Alterations in cytokine but not chemokine mRNA expression during three distinct
Theiler's virus infections.
AB - DA, GDVII and H101 are neurovirulent strains of Theiler's murine
encephalomyelitis virus that cause very different neuropathology and CNS disease
when inoculated into SJL/J mice. DA virus causes a chronic demyelinating disease,
GDVII virus causes an acute fatal polioencephalomyelitis, and H101 virus causes
an acute pachymeningitis with hydrocephalus. Performing RNase protection assays,
we detected the same pattern of chemokine (RANTES, MCP-1, IP-10, MIP-1beta, MIP
1alpha and MIP-2) mRNA expression in brain and spinal cord during all three
infections. In contrast, IFN-beta and IL-6 mRNA were highly expressed only in
GDVII virus infection, whereas high levels of LT-alpha mRNA were only found
during DA virus infection. Our study demonstrates that proinflammatory cytokines
are involved in the neuropathogenesis of CNS disease and modulate the acute and
chronic process underlying different pathologic features of disease.
PMID- 10683512
TI - Behavioral aspects of experimental autoimmune encephalomyelitis.
AB - Acute inflammation is known to induce a depressive-like sickness behavior
syndrome in humans and in experimental animals. In the present study, we sought
to determine whether a chronic neuroautoimmune inflammation is also associated
with a similar behavioral syndrome. Experimental autoimmune encephalomyelitis
(EAE) was induced in SJL/J female mice by adoptive transfer of lymph node cells,
and sickness behavior symptoms, including anorexia, loss of body weight, reduced
social exploration, and decreased preference for sucrose solution were measured.
We report that these components of sickness behavior were induced during the
acute phase of the disease, and recovered in later phases. Moreover, the onset
and recovery of the behavioral symptoms preceded the onset and recovery of the
neurological signs, respectively. Since EAE is considered a model for multiple
sclerosis (MS), it is suggested that EAF-induced behavioral changes may serve as
a model for the depressive symptomatology that characterizes most MS patients.
PMID- 10683513
TI - Impairment of rat thymocyte differentiation and functions by neonatal capsaicin
treatment is associated with induction of apoptosis.
AB - The direct and indirect interaction between the nervous system and its
transmitters with the immune system was evaluated in the rat by using the
neurotoxin capsaicin (Caps). In the present study we investigated the effect of
Caps administration to neonatal rats on thymocyte subpopulation distribution and
functions at different times after treatment. Caps treatment results in a marked
reduction of thymus weight and cellularity. As shown by immunofluorescence and
FACS analysis, profound depletion of double negative (DN), double positive (DP),
and single positive (SP) CD4(+) cells was already evident at day 7 after
treatment and persisted until day 28. Reduced numbers of SP CD8(+) cells were
observed only at later time points. Analysis of TCR phenotype indicates that
CD5(+) TCR gamma/delta(+) are particularly sensitive to neonatal Caps treatment.
Caps-induced thymocyte depletion was associated with reduced proliferation in
response to T cell mitogens. Moreover, in situ TUNEL reaction and agarose gel
electrophoresis indicate that neonatal Caps treatment induces apoptosis of thymus
cells. Morphological analysis reveals the presence of apoptotic cells in the
subcapsular thymus cortical region. Overall our results suggest that Caps when
administered at birth, profoundly affects T cell differentiation, likely through
its ability to activate apoptotic cell death program.
PMID- 10683514
TI - Encephalitogenic and immunogenic potential of the stress protein alphaB
crystallin in Biozzi ABH (H-2A(g7)) mice.
AB - The stress protein alphaB-crystallin is an immunodominant antigen in multiple
sclerosis (MS)-affected myelin for human T cells and is expressed at elevated
levels in MS lesions. Using bovine alphaB-crystallin and synthetic peptides based
on mouse alphaB-crystallin the ability of this stress protein to induce
experimental allergic encephalomyelitis (EAE) was screened in Biozzi ABH (H
2A(g7)) mice. While whole alphaB-crystallin and the immunodominant T cell
epitopes (49-64, 73-88, 153-168) failed to induce disease the subdominant or
cryptic epitope (1-16) was weakly encephalitogenic. The lack of
encephalitogenicity of whole protein and dominant epitopes may be due to the low
constitutive expression of alphaB-crystallin in the CNS combined with a state of
peripheral tolerance suggested by the constitutive expression of alphaB
crystallin in secondary lymphoid tissues in ABH mice. Further evidence for a role
of alphaB-crystallin in the progression of chronic relapsing neurological disease
is suggested by the development of T cell responses to alphaB-crystallin during
MOG-induced relapsing EAE as myelin damage accumulates. Together our data
indicate that normal tolerising mechanisms in ABH mice prevent the induction of
EAE by alphaB-crystallin while the subdominant or cryptic epitope is able to
circumvent these mechanisms and contribute to pathogenic myelin-directed
autoimmunity following T cell activation.
PMID- 10683515
TI - Axonal damage induced by cerebrospinal fluid from patients with relapsing
remitting multiple sclerosis.
AB - The importance of axonal damage in multiple sclerosis (MS) has been recently
stressed in proton magnetic resonance spectroscopy and pathological studies, but
the exact mechanism producing this damage is unknown. The aim of our study was to
ascertain whether soluble mediators present in the cerebrospinal fluid (CSF) of
patients with relapsing-remitting MS could induce neuron injury in culture.
Different biochemical and cytochemical parameters were determined in primary
embryonal rat neuron cultures following 8 days of exposure to CSF. Cytotoxic
activity was evaluated with a blue formazan production colorimetric assay.
Morphological and immunocytochemical studies performed with antibodies against
beta-tubulin revealed neuritic fragmentation, axonal damage and cellular
shrinkage indicating apoptosis. Detection of apoptosis was carried out using the
fluorescent DNA-binding dye Hoechst 33342, as well as by a Terminal
deoxynucleotidyl transferase-mediated dUTP Nick End-Labeling assay. We observed
that soluble factors in CSF from patients with "aggressive" MS i.e, those with
poor recovery after relapses, induced neurite breakdown and neuronal apoptosis in
cultures. Neuron injury is not related with blood-brain barrier dysfunction nor
with IgG index. Interestingly, CSF from patients with "non-aggressive" MS i.e.,
relapsing-remitting patients with a good recovery after relapses, did not induce
any damage. In conclusion, we report that CSF from patients with aggressive MS
bears soluble mediators that induce axonal damage and apoptosis of neurons in
culture. These mediators can be present during the first attack of the disease,
and the neuronal damage caused could be related to the functional deficit of
these MS patients.
PMID- 10683516
TI - The neuropeptides VIP and PACAP inhibit IL-2 transcription by decreasing c-Jun
and increasing JunB expression in T cells.
AB - Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating
polypeptide (PACAP) act as macrophage and T-cell deactivators. Previously we
established that VIP/PACAP limit T-cell activation directly, by inhibiting
interleukin 2 (IL-2), and indirectly, by reducing the macrophage costimulatory
functions. The nature of the IL-2 transcriptional factors affected by VIP/PACAP
has not been elucidated. Here we investigate the effect of VIP on the AP-l
complexes bound to several regulatory sites. VIP/PACAP downregulate c-Jun, and
upregulate JunB mRNA and protein. The reduction in c-Jun correlates with the
inhibition of the c-Jun N-terminal kinase (JNK). The effects of VIP/PACAP on c
Jun and JunB expression lead to changes in the composition of the AP-l complexes,
from c-Jun/Fos to JunB/Fos dimers, with a subsequent decrease in DNA binding and
loss of transactivating activity.
PMID- 10683517
TI - Lymphocytes from mice chronically infected with Theiler's murine
encephalomyelitis virus produce demyelination of organotypic cultures after
stimulation with the major encephalitogenic epitope of myelin proteolipid
protein. Epitope spreading in TMEV infection has functional activity.
AB - Theiler's murine encephalomyelitis virus (TMEV) infection produces a chronic
inflammatory disease of the spinal cord white matter, with striking similarities
to both experimental allergic encephalomyelitis (EAE) and human multiple
sclerosis (MS). The first phase of demyelination in this model appears to be
dependent on a delayed-type hypersensitivity (DTH) response to viral antigens,
driven by CD4+, Th1 lymphocytes. Macrophages, recruited in the infected CNS,
would be responsible for most of the myelin damage. Recently, new populations of
CD4+ lymphocytes were demonstrated in infected mice, this time with specificity
for myelin antigens, particularly PLP. This suggests that, in the chronic phase
of the disease, an autoimmune mechanism of demyelination, similar to EAE, may
participate in the process of myelin destruction. The present study represents a
first step in exploring the functional activity of these anti-myelin lymphocytes
that emerge during the chronic phase of the disease. Lymphocytes were removed
from chronically infected animals, they were stimulated with the major PLP
encephalitogenic epitope for SJL/J mice, and they were added to organotypic
myelinated spinal cord cultures for different lengths of time. Results show that
lymphocytes stimulated with the major PLP epitope have a powerful capacity for
demyelinating these cultures, while MBP stimulated lymphocytes and lymphocytes
from control animals do not. This study, suggests that the anti-myelin response
that emerges during the chronic phase of the infection is functionally active. A
similar phenomenon of epitope spreading from virus to organ specific antigens may
take place in humans and be involved in a number of immune-mediated diseases,
including MS.
PMID- 10683518
TI - Allograft-inflammatory-factor-1 is upregulated in microglial cells in human
cerebral infarctions.
AB - Allograft inflammatory factor-1 (AIF-1) is a 17-kDa-peptide identified in rat
cardiac allografts undergoing chronic rejection and in activated microglial cells
in inflammatory autoimune disease of the CNS. We have investigated the expression
of AIF-1 in 18 autopsy cases of human focal cerebral infarction. AIF-1-positive
cells show the morphology of microglia and are CD68- but not GFAP-positive. The
peptide is expressed at a low level in normal brain. In infarctions, activated
microglial cells in the area of glial reaction show strongly enhanced cytoplasmic
immunoreactivity. The density of AIF-1-expressing cells increases during the
first three days post infarction and remains elevated until chronic cystic
stages. The upregulation of AIF-1-immunoreactivity precedes the rise in
expression of the S-100-protein MRP-8. We conclude that AIF-1 is a sensitive
marker of human microglial activation not only in inflammation but also in non
inflammatory lesions of the CNS.
PMID- 10683519
TI - Chemokines and their receptors in neurobiology: perspectives in physiology and
homeostasis.
AB - Chemokines are a large family of small secreted proteins (8-14 kDa) associated
with the trafficking of leukocytes in physiological immunosurveillance as well as
inflammatory cell recruitment in different disease processes. A limited
repertoire of chemokines and their specific cognate receptors are detectable in
cells of the CNS such as microglia, astrocytes and neurons under physiological
conditions. Coupled with distinct patterns of ligand and receptor expression in
various pathologies including multiple sclerosis, trauma, neuro-AIDS, Alzheimer's
disease, stroke, neuro- and glioblastomas, such phenomena have fueled the strong
belief that chemokines must fulfill significant and potentially diverse
functional roles in the CNS.
PMID- 10683520
TI - Genetic variation at position -1082 of the interleukin 10 (IL10) promotor and the
outcome of multiple sclerosis.
AB - Interleukin-10 is a potent immunomodulatory cytokine with possible implications
for the pathogenesis of multiple sclerosis. Increased IL10 mRNA expression is
associated with stable disease. The interleukin 10 gene is highly polymorphic and
certain haplotypes result in differential interleukin-10 expression. The presence
of guanine instead of adenine at position -1082 in the IL10 promotor was shown to
result in a higher IL10 production. We analysed this diallelic polymorphism in
patients with multiple sclerosis but did not find any association between a
certain -1082 IL10 genotype and susceptibility to or severity of multiple
sclerosis.
PMID- 10683521
TI - Protein-protein interactions in neurotransmitter release.
AB - The arrival of a nerve impulse at a nerve terminal leads to the opening of
voltage-gated Ca(2+) channels and a rapid influx of Ca(2+). The increase in
Ca(2+) concentration at the active zone from the basal level of 100-200 mM
triggers the fusion of docked synaptic vesicles, resulting in neurotransmitter
release. A large number of proteins have been identified at nerve terminals and a
cascade of protein-protein interactions has been suggested to be involved in the
cycling of synaptic vesicle states. Functional studies in last half decade on
synaptic-terminal proteins, including Ca(2+) channels, have revealed that the
SNARE core complex, consisting of synaptobrevin VAMP, a synaptic vesicle
associated protein, syntaxin and SNAP-25, synaptic membrane-associated proteins,
acts as the membrane fusion machinery and that proteins interacting with the
SNARE complex play essential roles in synaptic vesicle exocytosis by regulating
assembly and disassembly of the SNARE complex.
PMID- 10683522
TI - Lambert-Eaton myasthenic syndrome as an autoimmune calcium-channelopathy.
AB - Lambert-Eaton myasthenic syndrome (LEMS), often associated with small cell lung
carcinoma (SCLC), is a disease of neuromuscular transmission in which antibodies
directed against voltage-gated calcium channel (VGCC) in the motor nerve terminal
play a crucial role in causing a deficient quantal release of acetylcholine. We
focused attention on the P/Q-type VGCC, against which a majority of LEMS patients
carry the specific antibody. Since the P/Q-type VGCC expresses in SCLC, the motor
nerve terminal and SCLC may share a common VGCC antigen. In search for antigenic
sites at the molecular level, We employed peptides or recombinant protein
corresponding to the S5-S6 linker of each of four domains forming the alpha 1A
subunit and tested their antigenicity. As the result, we specified the domain II,
III and IV as immunodominant sites by the induction of an immune-mediated animal
model of LEMS and the assay for antibodies in LEMS patients. Also, by use of
peptides or recombinant protein corresponding to the synaptotagmin I, we found
that in this VGCC-associated protein, the segment which exposes extracellularly
during exocytosis can be antigenic for LEMS.
PMID- 10683523
TI - Consistency behind trial-to-trial variation in intrinsic optical responses to
single-whisker movement in the rat D1-barrel cortex.
AB - We examined consistent characteristics behind the trial-to-trial variati on in
intrinsic optical imaging of single barrel cortical responses to D 1-whisker
movement in 2-5-week postnatal (2-5 W) and adul t (>9-weeks) Wistar rats, and we
identified the effective are a of the neural response. The extent/size,
configuration and orientation of the intrinsic optical response area varied from
trial-to-trial with the same whisker stimulation. We argue that the trial-to
trial variation was due to cortical blood circulation related to the barrel
neural activity. Subsequently, interpolating a family of the traces of the
optical response area imaged with repeated stimulation for each animal, we
extracted a centered circular area from the trial-to-trial response for each
animal. Although the trial-to-trial variation decreased gradually with age, the
spatial extent of the interpolated response area was consistently about 660
microm in diameter, in agreement with that measured morphologically and/or
histochemically. A possible interpretation is that the optically defined area
appears to image the actual effective single-barrel response area, as a first
approximation. Furthermore, the constancy of the extracted area independent of
age suggests that the barrel cortex is, in fact, virtually mature by 2 weeks of
age. The extracted area was also nearly independent of the frequency (>/=5 Hz) of
whisker movement.
PMID- 10683524
TI - A DPDPE-induced enhancement of inward rectifier potassium current via opioid
receptor in neuroblastomaxglioma NG108-15 cells.
AB - The effect of a delta-selective opioid agonist, DPDPE([D-Pen(2, 5)]-enkephalin),
on the inward rectifier potassium current (I(KIR)) of NG108-15 cell was studied
by whole cell voltage-clamp technique. It was found that microM DPDPE increased
the amplitude and delayed the activation and inactivation of I(KIR) rapidly and
reversibly. These effects could be reversed by naloxone, but were still obtained
in pertussis toxin (PTX) preincubated cells or when using GDP-betas (guanosine 5'
o-[2-thio] diphoaphate) containing electrodes to block the G-protein coupled
events. The above results suggest that DPDPE-induced change of I(KIR) is mediated
by delta-opioid receptor but does not involve G-proteins.
PMID- 10683525
TI - Characteristics of monocarboxylates as energy substrates other than glucose in
rat brain slices and the effect of selective glial poisoning - a 31P NMR study.
AB - In rat brain slices we examined the differences in the levels of high-energy
phosphates in the presence of various energy substrates by using 31P NMR with a
time resolution of 4 min at 25 degrees C. In parallel experiments we recorded
population excitatory postsynaptic potentials (EPSPs) from granule cells in rat
hippocampal slices. During high K(+) stimulation (8 min) phosphocreatine (PCr)
decreased to a low level and recovered to the control level in standard
artificial cerebrospinal fluid (ACSF) in about 10 min. Population EPSPs
disappeared following high-K(+) stimulation and recovered in standard ACSF. In
iodoacetic acid (IAA)-pretreated slices, whereas glucose was unable to support
energy metabolism, the PCr level, which decreased following high-K(+)
stimulation, recovered in ACSF containing lactate or pyruvate. The half-time of
recovery of PCr levels in ACSF containing lactate was longer than that containing
glucose. Population EPSPs in standard ACSF were maintained for more than 1 h, but
those in ACSF containing lactate decreased gradually by about half in 40 min. In
IAA-pretreated slices, when further treated with fluorocitrate (100 microM) for 2
h, the recovery of the PCr level in ACSF containing lactate after high-K(+)
stimulation was completely abolished, whereas the recovery of the PCr level in
ACSF containing pyruvate was unaffected. These results indicate that neurons can
utilize pyruvate as well as glucose, but not lactate, as exogenous energy
substrates, and that lactate may be metabolized to pyruvate in glial cells and
transported to neurons to be utilized as an energy substrate.
PMID- 10683526
TI - The effects of binocular suture and dark rearing on the induction of c-fos
protein in the rat visual cortex during and after the critical period.
AB - It has been demonstrated in kittens that binocular lid suture has more
deleterious and irreversible effects on plasticity of the developing visual
system than rearing in complete darkness. The present study using
immunocytochemistry focuses on the effects of the two types of visual deprivation
on the inducibility of c-fos protein in visual cortical neurons of rats. Rats
were subjected to binocular suture or dark rearing for 1 week during (postnatal
days 14-21; P14-P21) and after (P50-P57) the critical period for activity
dependent modifiability of cortical ocular dominance. In rats of both age groups
reared in the normal light-dark condition, only a small number of Fos
immunoreactive neurons was obtained in the visual cortex. By contrast, in dark
reared pups and adult rats, numerous c-fos neurons were detected in the layers II
IV and VI of the visual cortex following a brief light exposure (1 h). In rats of
both ages subjected to binocular suture, Fos neurons were detected in the same
layers as in the dark-reared rats, but significantly less in number. We speculate
that the reduced plasticity of the visual cortex in the rats subjected to
binocular suture may be due partly to the repressed AP-1 activity in visual
cortical neurons. No significant difference was detected in c-fos expression in
the visual cortex between visually manipulated pups and adult rats.
PMID- 10683527
TI - The role of fixation point and subjects' readiness in the occurrence of express
saccades as revealed by the self-initiation paradigm.
AB - The role of fixation and the subjects' response preparedness in producing express
saccades were explored in seven human subjects. The occurrence frequencies of the
express saccades were compared in the overlap (continuous presentation of
fixation point), gap (fixation point offset 0-400 ms prior to target onset) and
no-fixation tasks under the conventional and self-initiation paradigms. In the
latter paradigm, the subjects, when ready, touched a sensor in order to ignite
the target lamp with a delay time of 0-400 ms (target onset delay time).
Therefore, the subjects' response preparedness might be expected to be higher
than that in the normal paradigm and equated in each subject at the time when the
subjects touched a sensor regardless of the paradigms. Although express saccades
were produced neither in the normal overlap nor in the normal no-fixation tasks,
they could be produced at the rate of 24 and 48% in the overlap and no-fixation
tasks under the self-initiation paradigm, respectively. The highest occurrence
frequency of express saccades was obtained when the gap paradigm was combined
with the self-initiation paradigm with a delay time of 100 ms (62%). The value
was higher by 20% than in the normal gap task. At a target onset delay time of 0
ms under the self-initiation paradigm, the occurrence frequency of express
saccades was higher in the overlap task than in the gap task. These results
suggest that the subjects' response preparedness has a potentiality to produce
express saccades without fixation point offset and that fixation point offset at
the same time of the target stimulus onset has an interference, rather than
facilitatory, influence on the generation of express saccades.
PMID- 10683528
TI - Circadian release of excitatory amino acids in the suprachiasmatic nucleus
culture is Ca(2+)-independent.
AB - We have previously reported that spontaneous release of excitatory amino acids
(aspartate and glutamate) show remarkable circadian rhythms in the organotypic
slice culture of rat suprachiasmatic nucleus (SCN). Here we showed effects of
extracellular Ca(2+) removal and of L-trans-pyrrolidine-2,4-dicarboxylic acid, a
glutamate/aspartate uptake inhibitor on the circadian release of excitatory amino
acids in the SCN culture. Amino acids were measured by high-performance-liquid
chromatography. Removal of extracellular Ca(2+) exerted no effect on the
spontaneous release of the excitatory amino acids, while it blocked high K(+)
evoked release of the amino acids. Neither the period nor the amplitude of the
spontaneous circadian release of amino acids in Ca(2+)-free medium was different
from those in the Ca(2+)-containing medium. On the other hand, L-trans
pyrrolidine-2,4-dicarboxylic acid increased the excitatory amino acid levels
without affecting the amplitude of excitatory amino acid rhythms. These results
indicated that the circadian release of excitatory amino acids in the SCN is
Ca(2+)-independent and L-trans-pyrrolidine-2,4-dicarboxylic acid- insensitive.
Therefore, Ca(2+)-dependent chemical synaptic transmission may not be involved in
the circadian rhythm generation in the SCN.
PMID- 10683530
TI - Synaptic architecture of glomeruli in lamina II of the chicken spinal cord, as
revealed using ultrathin section and freeze fracture techniques.
PMID- 10683529
TI - The p44/42 mitogen-activated protein kinase cascade is involved in the induction
and maintenance of astrocyte stellation mediated by protein kinase C.
AB - The mitogen-activated protein kinase (MAPK) is known to be involved in the
differentiation of various types of cells. To understand the role of p44/42 MAPK
(ERK1/2) in astrocyte differentiation, we investigated the effects of U0126 and
PD98059, specific inhibitors of the MAPK-activating enzyme MEK, on astrocyte
morphology in culture. Cultured rat cortical astrocytes exhibited flattened,
polygonal morphology in the absence of stimulation, but differentiated into
process-bearing stellate cells in response to the membrane-permeable cyclic AMP
analog dibutyryl cyclic AMP (dBcAMP) or the protein kinase C (PKC) activator
phorbol 12-myristate 13-acetate (PMA). dBcAMP-induced astrocyte stellation was
not affected by MEK inhibitors, while PMA-induced astrocyte stellation was
significantly blocked by U0126 (0.1-10 microM) and PD98059 (10-30 microM).
Western blot analysis with an antibody specific for phosphorylated ERK1/2
revealed that PMA, but not dBcAMP, induced phosphorylation of ERK1/2 in a time-
and concentration-dependent manner. The PMA-induced astrocyte stellation and
ERK1/2 phosphorylation were blocked by specific PKC inhibitors, GF-109203X (0.01
1 microM) and calphostin C (1 microM). In addition, when U0126 or PD98059 was
added after treatment with PMA, stellate astrocytes returned to polygonal. These
results suggest that the MEK/ERK cascade is involved in the induction and
maintenance of astrocyte stellation mediated by PKC, but not by cyclic AMP
signaling.
PMID- 10683531
TI - Preface
PMID- 10683532
TI - Introduction and official welcome to the congress
PMID- 10683533
TI - Who needs vaccination against hepatitis viruses?
PMID- 10683534
TI - Keynote speech: health education and promotion programmes--the accountability
aspect.
AB - In the early days of health education, people depended on health education
specialists to provide information about diseases and their prevention. The
differentiation between health promotion and health education, and the emphasis
on the settings approach have resulted in the inclusion of a wide range of people
and professions into these activities. This has raised the question of the
protection of consumers, and the issue of accountability has become a major
focus. This paper briefly traces the history of health education and promotion,
with particular emphasis on the way people have dealt with accountability in the
past as a platform for the future. The Polish model of hepatitis B vaccination is
used to illustrate these developments.
PMID- 10683535
TI - Special address: safety of hepatitis B vaccination.
PMID- 10683536
TI - Hepatitis B epidemiology in Poland, Central and Eastern Europe and the newly
independent states.
AB - The incidence of hepatitis B virus (HBV) infection varies considerably in
countries in Central and Eastern Europe and the Newly Independent States, but
data are difficult to compare between countries because of the large differences
in levels of diagnosis, particularly serological identification, and levels of
notification. Poland has high levels of diagnosis, including laboratory
diagnosis. In the past, the incidence of hepatitis B in Poland was approx. 45
reported cases per 100,000 population, but following the introduction of improved
sterilization of medical equipment in 1986 and a selective programme of
vaccination in 1991, the incidence fell to about 35 per 100,000 by 1993. In 1993,
an intensive vaccination campaign was launched, which has reduced the incidence
to under 15 per 100,000. The incidence of HBV infection has decreased across all
age groups and in both men and women, and in the under 3 years age group only 32
cases in total were reported in 1997. In 1996 and 1997, there was a slight
relative increase in the incidence of HBV infection in men aged 20-24 years. This
group may be a target for future vaccination programmes and other activities of
control for the infection.
PMID- 10683537
TI - Hepatitis B epidemiology in Latin America.
AB - The available data on prevalence of hepatitis B virus (HBV) infection in Latin
America are incomplete and largely based on analysis of blood banks, which are
not stratified by age or social class. An epidemiological study was recently
undertaken in six countries in Latin America to update the data. The highest
seroprevalence of antibody to the HBV core antigen (anti-HBc) was found in the
Dominican Republic (21.4%), followed by Brazil (7.9%), Venezuela (3.2%) and
Argentina (2.1%). The lowest seroprevalence was found in Mexico (1.4%) and Chile
(0.6%). The seroprevalence in different regions of Brazil varied from 21% in
Manaus to 1.2% in Fortaleza. There were no differences in seroprevalence of anti
HBc between females and males except in Brazil (significantly higher in males)
and in the Dominican Republic (significantly higher in females). In Brazil alone,
higher seroprevalence was associated with lower socioeconomic class. In both the
Dominican Republic and Brazil, seroprevalence was high in childhood, and in
Brazil and Argentina, anti-HBc was detected in 3.0-6.6% of children up to 1 year
old, suggesting vertical transmission. Other risk factors included dental and
surgical procedures, sexual activity and tattooing. There was an increase in
seroprevalence in all countries at or after adolescence, suggesting that sexual
activity is a major route of transmission.
PMID- 10683538
TI - Hepatitis B epidemiology in Asia, the Middle East and Africa.
AB - Asia and Africa have previously been classified as areas of high endemicity for
hepatitis B virus (HBV), but in some countries highly effective vaccination
programmes have shifted this pattern towards intermediate or low endemicity.
Thus, China is now the only country in Asia where HBV endemicity is high.
Countries with intermediate endemicity include India, Korea, the Philippines,
Taiwan and Thailand, and those with low endemicity include Japan, Pakistan,
Bangladesh, Singapore, Sri Lanka and Malaysia. Most countries in Africa have high
HBV endemicity, with the exceptions of Tunisia and Morocco, which have
intermediate endemicity. Zambia has borderline intermediate/high endemicity. In
the Middle East, Bahrain, Iran, Israel and Kuwait are areas of low endemicity,
Cyprus, Iraq and the United Arab Emirates have intermediate endemicity, and
Egypt, Jordan, Oman, Palestine, Yemen and Saudi Arabia have high endemicity. All
of these Middle East countries reach a large proportion of their population with
hepatitis B vaccination, which is reducing the infection rate, particularly in
Saudi Arabia. The vaccination programme in Taiwan has also greatly reduced the
HBV infection rate. Future vaccination programmes must take into account the mode
of transmission of HBV, the healthcare infrastructure to deliver vaccination, and
the socioeconomic and political factors in each individual country, to determine
the most cost-effective way of infection control.
PMID- 10683539
TI - Clinical course and consequences of hepatitis B infection.
AB - Hepatitis B virus (HBV) is a small enveloped virus containing partially double
stranded DNA. The DNA and HBV-specific DNA polymerase are surrounded by the HBV
core antigen (HBcAg), which in turn is surrounded by a lipoprotein envelope
containing the HBV surface antigen (HBsAg). Serum of HBV-infected patients
contains complete virus particles, as well as non-infectious spherical or
filamentous HBsAg particles. Acute hepatitis is characterized by the appearance
of serum HBV markers, including HBsAg and IgM anti-HBc, which then disappear
during convalescence. Persistence of HBsAg for more than 6 months indicates a
carrier state. Chronic hepatitis develops in 90% of newborns who become infected,
compared with 29-40% of children infected and 5-10% of adults infected. The
immune status of the infected person also influences the development of chronic
hepatitis. Chronic HBV infection can be diagnosed by serology (identification of
HBsAg and HBV DNA), biochemistry (elevated aminotransferase levels) and liver
biopsy. The last is important to assess the severity of disease, its stage and
prognosis, and to exclude other hepatic diseases. The outcome of chronic HBV
infection varies between individuals, with estimated 5-year survivals of 97% for
chronic persistent hepatitis, 86% for chronic active hepatitis, and 55% for
chronic active hepatitis with cirrhosis. Treatment with interferon alpha is
effective in up to 40% of cases, but in view of the very large number of infected
people worldwide, vaccination to prevent spread of the disease is a more cost
effective option.
PMID- 10683540
TI - Teenagers' lifestyle and the risk of exposure to hepatitis B virus.
AB - Prevention of lifestyle-related diseases and promotion of physical and mental
well-being in adolescents require an understanding of how life situations place
adolescents at risk. The most important risk factors for hepatitis B virus (HBV)
infection are sexual activity with more than one partner and injecting drug use.
Sexual transmission is particularly important in areas of low endemicity, but is
increasingly important in areas of high endemicity as young people adopt a
'Western' lifestyle. HBV infection in general is associated with indicators of
sexual activity, e.g. number of sexual partners, years of sexual activity and the
occurrence of other sexually transmitted diseases (STDs). Risk behaviours are
often associated: adolescents who have frequent sexual intercourse also drink
more alcohol, smoke more cigarettes, use marijuana more often and wear seat-belts
less often when driving than adolescents who have little or no sexual activity.
Health education and health promotion are important activities aimed at
preventing HBV infection, but the major strategy should be providing immunity
from infection before risk-taking behaviour. As for other STDs, this is best
achieved by universal vaccination of young adolescents or infants or both.
PMID- 10683541
TI - Rationale for the infant and adolescent vaccination programmes in Italy.
AB - In Italy in the 1980s, the incidence of acute hepatitis B was about 13 per
100,000, corresponding on average to 7500 new symptomatic cases per year was
about 3%, making Italy an area of intermediate endemicity. HBV infection was also
associated with 12 per 100,000 deaths from cirrhosis and with 5.1 per 100,000
deaths from hepatocellular carcinoma. In view of the large numbers of pregnant
women who were hepatitis B surface antigen (HBsAg)-positive, selective hepatitis
B vaccination of all newborns to these mothers and of other high-risk groups was
introduced in 1983. Compliance was high among the newborns but low in other high
risk groups. Hepatitis vaccination was adopted in Italy in 1991, including each
year all newborns, all adolescents aged 12 years and other high-risk groups.
Compliance has been nearly 95% for newborns and 80% for adolescents. Since the
introduction of vaccination, both the incidence of acute hepatitis B and the
prevalence of HBV carriage have fallen, the latter from 3.4% in 1985 to 0.9% in
1996. There is good evidence that these decreases are mainly the result of the
vaccination programmes. Although the full economic impact cannot yet be assessed,
about 18,000 cases of acute HBV infection have been prevented over the 6 years
since starting the mass vaccination programme, with cost savings of about US$
244,308,000.
PMID- 10683542
TI - Nationwide vaccination: a success story in Taiwan.
AB - In the early 1980s, 15-20% of the population of Taiwan were estimated to be
hepatitis B virus (HBV) carriers. A programme of mass vaccination against
hepatitis B was therefore launched in 1984. In the first 2 years, newborns of all
HBVsurface antigen (HBsAg)-positive mothers were vaccinated. Since 1986, all
newborns, and then year by year pre-school children, primary school children,
adolescents, young adults and others have also been vaccinated. Vaccination
coverage is over 90% for newborns, with 79% of pregnant women screened for HBsAg.
The proportion of babies born to highly infectious carrier mothers who also
became carriers decreased from 86-96% to 12-14%; the decrease was from 10-12% to
3-4% for babies of less infectious mothers. Between 1989 and 1993, the prevalence
of HBsAg in children aged 6 years also fell from 10.5 to 1.7%. The average annual
incidence of hepatocellular carcinoma in children aged 6-14 years decreased
significantly from 0.7 per 100,000 in 1981-1986 to 0.36 per 100,000 in 1990-1994
(P<0.01). Similarly, the annual incidence of hepatocellular carcinoma in children
aged 6-9 years declined from 0.52 per 100,000 for those born in 1974-1984 to 0.13
per 100,000 for those born in 1986-1988 (P<0.001). The mass vaccination programme
is highly effective in controlling chronic HBV infection and in preventing liver
cancer in Taiwan. If a coverage rate of 90% of all newborns vaccinated against
hepatitis B can be maintained, by the year 2010 the carrier rate in Taiwan is
expected to decline to <0.1%.
PMID- 10683543
TI - Discussion 1
PMID- 10683544
TI - The expanded programme on immunization calendar in Poland.
AB - Poland has a long history of prophylactic vaccination against infectious
diseases. Hepatitis B vaccination was introduced in Poland between 1989 and 1996
as part of the Expanded Programme on Immunization (EPI). All newborns and those
at high risk of hepatitis B virus (HBV) infection currently receive hepatitis B
vaccine free of charge. For many years Poland has reached or exceeded the
indicators required by the World Health Organization for vaccination programmes,
and about 10% of the population has now been vaccinated against hepatitis B. The
incidence of hepatitis B has decreased from about 40 per 100,000 in the early
1990s to 12.7 per 100,000 in 1997. It is hoped to modify the EPI in the future to
improve vaccination against mumps, rubella and poliomyelitis. The possible
benefit of vaccination against Haemophilus influenzae type b is currently being
evaluated. Financial constraints, however, mean that not all of the approved
vaccinations can be implemented. The EPI is supported by recommended vaccinations
in certain groups, who pay for the vaccines. For hepatitis B, these include
children, teenagers, those between 20 and 40 years of age, and those at high risk
because of lifestyle or occupation.
PMID- 10683545
TI - The hepatitis B prevention education programme in Poland.
AB - The main objective of the hepatitis B prevention education programme in Poland is
to promote education in the school setting. The programme stems from the national
policy for the prevention of hepatitis B virus (HBV) infection and is an element
of the national Health Prevention Programme. The main aims of the programme
include reducing morbidity from HBV infection by increasing community awareness,
facilitating access to vaccination, establishing local lobbies to support the
programme, and encouraging cooperation with vaccine producers. The education
programme has been implemented in three phases, starting with a pilot programme
in 1996 that was extended to half of Poland in 1997 and to the whole country in
1998. The programme is divided into five stages, consisting of meetings at
central, voivodship and local levels, vaccination of children and evaluation of
the programme.
PMID- 10683546
TI - Evaluation of the hepatitis B prevention education programme in Poland.
AB - Evaluation of the hepatitis B prevention education programme was performed as a
survey including all the coordinators in 25 regions (211 coordinators; half the
country). The success of the programme was defined by an objective measure (the
ratio of vaccinated children to the total number of children in a region) and a
subjective measure (the need to introduce changes in current procedures). The
best information was felt to be provided on the subjective area, with financial
aspects raising the most doubts. There was a high level of participation in local
training by school nurses, but insufficient participation by paediatric nurses
and paediatricians. In one-third of the regions schools fulfilled the tasks set
them, but in 19% of the regions only a few schools did. Information about
vaccination was given in most public children's clinics in 65% of the regions,
but there was no activity in 6% of the regions. Recruitment of sponsorship was
successful, with only 12% of parents paying the full cost of vaccination. The
most important factors contributing to the success of the education programme
were the health education and the epidemiology departments of state sanitary
inspection, the schools' medical services and paediatric services. The greatest
perceived need for change in procedures was in the area of cooperation with local
authorities. Only 56% of those surveyed felt the director of the local sanitary
station participated to a significant extent, though the programme is very
dependent on such participation. Overall, 12% of the regions achieved a ratio of
20 or more between vaccinated and non-vaccinated children, with another 52%
reaching a ratio of 5-19.9. The perceived need for changes in cooperation with
the Health Service was smaller in regions in which the ratio of vaccinated
children was higher. The survey showed a connection between the results of the
education programme and the incidence of hepatitis B virus infection.
PMID- 10683547
TI - Cost-benefits of vaccination programmes.
AB - Decision-makers are increasingly demanding hard economic data as a basis for the
allocation of limited healthcare resources. The main types of evaluation that are
available are cost-benefit analysis, cost-effectiveness analysis and cost-utility
analysis. Cost-effectiveness analysis is a tool that helps decision-makers to
decide on the best use of allocated resources, whereas cost-benefit analysis is a
tool that helps policy-makers decide on the overall allocation of resources. The
basis of the cost-utility analysis is the quality-adjusted life year (QALY),
which allows a direct comparison of a wide range of medical interventions. The
cost per QALY for a range of childhood vaccinations can be compared in order to
plan a vaccination programme. Public health vaccines warrant a cost-benefit
approach, in order to determine if they are worthwhile, whereas recommended
vaccines might be more usefully assessed by cost-effectiveness analysis. It is
also important to look at combinations of vaccines, which offer large economic
advantages by reducing costs (time and equipment) and ensuring better acceptance
(improved coverage and reduced risk of disease). Although cost-savings do not
necessarily equate with cost-effectiveness, cost-savings are achieved in many
vaccination programmes.
PMID- 10683549
TI - Discussion 2
PMID- 10683548
TI - Cost-benefit analysis of the Polish hepatitis B prevention programme.
AB - This paper presents a cost-benefit analysis of hepatitis B vaccination in Poland.
The costs relating to hepatitis B are based on official epidemiological data and
a validated model, and amount to 1324.2 million Polish zlotys. The annual costs
of vaccination amounted to 120 million zlotys, which when projected over a 20
year period with appropriate adjustment give a total cost of the vaccination
programme of 2676 million zlotys. If vaccination is held at its present level for
the next 20 years, the total value of benefits would be 12,046.4 million zlotys
and of losses due to hepatitis B despite vaccination would be 14,437.0 zlotys. If
no hepatitis B vaccination were performed, however, the total loss due to HBV
infection is estimated to be 26,484.2 million zlotys. There is clearly a wide gap
between the losses due to HBV infection despite vaccination and the costs of the
vaccination programme. This clearly shows that the sooner total community
vaccination is achieved, the greater the benefits. This may be achieved by
vaccinating schoolchildren in the first year of school and by broadening the
definitions of high-risk groups.
PMID- 10683550
TI - Hepatitis A shifting epidemiology in Latin America.
AB - In the past, Latin America was considered to be an area of high endemicity for
hepatitis A virus (HAV) infection, with most people infected in early childhood.
A seroepidemiological study was recently undertaken in six countries to determine
whether this pattern has changed. The highest seroprevalence of antibodies to HAV
(anti-HAV) was found in Mexico and the Dominican Republic. Analysis of the
different age groups showed that at age 6-10 years, 30% of children in Chile and
54-55% in Brazil, Venezuela and Argentina had been infected, compared with almost
70% in Mexico and 80% in the Dominican Republic. At age 11-15 years, nearly 90%
in Mexico and 91% in the Dominican Republic had been infected, compared with 54%
in Argentina, 62% in Venezuela, 60% in Brazil and 70% in Chile. By age 31-40
years, over 80% of the populations in all six countries had been exposed to HAV.
In all of the countries except Brazil and Venezuela, the seroprevalence of anti
HAV was significantly higher in females than in males. In Mexico, Argentina and
Brazil, anti-HAV seroprevalence was significantly higher in the low socioeconomic
groups than in the middle/high socioeconomic groups. The results show that there
has been a shift from high to medium endemicity of HAV infection throughout Latin
America, which may result in more clinical cases in adolescents and adults and a
greater potential for outbreaks. The vaccination strategy for hepatitis A should
thus be reviewed.
PMID- 10683551
TI - Hepatitis A shifting epidemiology in South-East Asia and China.
AB - A review of the epidemiology of hepatitis A virus (HAV) infection over the last
20 years shows shifting patterns in the prevalence of antibodies to HAV (anti
HAV) throughout South-East Asia and China. A number of countries have shifted
from high to moderate and from moderate to low endemicity, with a corresponding
increase in the age of exposure from childhood to early adulthood. The changes
have resulted from improvements in hygiene, sanitation and the quality of
drinking water, reflecting improvements in living standards and socioeconomic
progress. In general in the late 1970s and early 1980s, 85-95% of the population
of developing countries like the Philippines, Korea, China and Thailand were anti
HAV-positive by age 10-15 years, compared with only about 50% in the more
affluent countries like Malaysia and Singapore. In the early 1990s, 85-95% of the
population were immune by age 30-40 years in the Philippines, Korea, China and
Thailand, and by 50 years of age and above in Malaysia and Singapore. Similar
trends were noted in Hong Kong, Taiwan and Japan. Exposure to HAV at a later age
may be associated with an increase in hepatitis A morbidity and a greater
propensity for outbreaks.
PMID- 10683552
TI - Hepatitis A shifting epidemiology in the Middle East and Africa.
AB - Data on the endemicity of hepatitis A virus (HAV) infection in Africa and the
Middle East are scant, but most of Africa appears to remain a high endemicity
region, with the exception of subpopulations in some areas, e.g. White people in
South Africa. Saudi Arabia is a model for the Middle East, and is a country in
which shifting HAV epidemiology has been documented in recent years, concurrent
with the social and economic development that has occurred over the last two
decades. Earlier studies generally showed very high prevalence rates, with most
people becoming infected in early childhood. Between 1989 and 1995, however,
there was a significant fall in the seroprevalence of antibodies to HAV in
children up to 12 years old throughout the country except in one region bordering
the Yemen. The highest seroprevalence is found in children from rural
backgrounds, while the seroprevalences in Bedouin and urban children are similar.
Seroprevalence is related to socioeconomic status, being highest in the lowest
groups. Similar findings have been reported from other countries in the Middle
East. The existence of pockets of high endemicity for HAV infection with
surrounding areas shifting towards intermediate endemicity may lead to outbreaks,
and widespread vaccination should be considered.
PMID- 10683553
TI - Hepatitis A shifting epidemiology in Poland and Eastern Europe.
AB - The clinical morbidity of hepatitis A probably only represents 20% of cases of
hepatitis A virus (HAV) infection. When it became possible to determine specific
antibodies, a seroepidemiological survey of anti-HAV was undertaken in Poland,
which showed that between 1979 and 1997 there was a shift in the peak age of
infection from childhood to adulthood, concomitant with a substantial decline in
the incidence of HAV infection. Data from the World Health Organization also
indicate that there has also been a decline in the incidence of hepatitis A in
Eastern European countries in general, over the 3 years from 1994 to 1996. The
potential risk of epidemics still exists, however, when appropriate conditions
are created. The available data show that fewer young people are becoming
infected with HAV, and general preventive measures, including vaccination of
children and high-risk groups (e.g. healthcare and childcare personnel and those
living in 'closed communities') are needed to deal with HAV infections in Eastern
Europe.
PMID- 10683555
TI - Discussion 3
PMID- 10683554
TI - Clinical course and consequences of hepatitis A infection.
AB - Hepatitis A virus (HAV) is a small, non-enveloped RNA virus belonging to the
Picornaviridae, for which only one serotype has been identified. Transmission is
usually through the faecal-oral route by person-to-person contact. The most
common risk factors are household or sexual contact with a sufferer, attendance
or working at a day-care centre, international travel, and association with food
or waterborne outbreaks; 55% of cases have no identifiable risk factors. HAV
infection may be symptomatic or asymptomatic, and shows three phases. Virus is
shed during the incubation phase, anti-HAV IgM appears during the symptomatic
phase and can be used for diagnosis, and anti-HAV IgG appears at the same time
but persists lifelong. Unusual clinical manifestations of hepatitis A include
cholestatic, relapsing and fulminant hepatitis. Hepatitis A accounts for 93% of
cases of acute hepatitis in Argentina, including 7% of atypical clinical cases.
Hepatitis A is the major cause of fulminant hepatitis, and has been reported to
account for 10% of liver transplants in children in France and 20% in Argentina.
One-year survival after liver transplantation is 64%. Prevention must be
considered as the main means of averting this severe illness.
PMID- 10683556
TI - Hepatitis B school-based vaccination programmes in the USA: a model for hepatitis
A and B.
AB - Following the recommendation for routine vaccination against hepatitis B virus
for newborns, many states have started school-based catch-up vaccination of 11-
to 12-year-olds. Implementation of these programmes requires educational and
promotional initiatives to increase awareness among parents, children, teachers,
school nurses, school boards and administration. Experience in Framingham,
Massachusetts, suggests that over 90% of targeted hepatitis B vaccine coverage
can be achieved. Because hepatitis B vaccination targeted at high-risk groups in
the USA was largely unsuccessful, this suggests that the initial similar targeted
approach with hepatitis A vaccination will also fail. Only about 50% of hepatitis
A cases have a known risk factor, and multiple high-risk areas exist throughout
the USA. However, the geographical clustering of these high-risk areas and the
occurrence of periodic outbreaks, suggest that school-based hepatitis A
vaccination programmes may be effective in reducing the risk of infection. A
voluntary programme in San Antonio achieved 43% of the targeted coverage in its
first year, and a compulsory programme is due to start in Oklahoma. The
effectiveness of this programme is not yet known, but future recommendations are
likely to include hepatitis A vaccination as a school entry requirement in areas
with high incidence of hepatitis A.
PMID- 10683557
TI - Prospects for vaccination against hepatitis A and B in Catalonia (Spain).
AB - Catalonia is in an area of intermediate endemicity for hepatitis A virus (HAV)
infection. An Expert Committee has recently proposed the implementation of
universal hepatitis A vaccination for 12-year-olds, based on the fact that no
risk factors can be identified for hepatitis A in 50% of cases, and also that
selective vaccination targeted at high-risk groups has a limited potential to
reduce the incidence of hepatitis A. The well-established programme of hepatitis
B vaccination of pre-adolescents in Catalonian schools has high levels of
vaccination coverage. This will provide a means to introduce hepatitis A
vaccination in a cost-effective way in schools, by replacing the single vaccine
with the combined hepatitis A and B vaccine. High-risk groups will also continue
to be targeted. A pilot programme has commenced in the 1998/1999 school year and
will be evaluated after 3 years. If it is successful, it will be extended
indefinitely.
PMID- 10683558
TI - From hepatitis B to hepatitis A and B prevention: the Puglia (Italy) experience.
AB - The incidence of hepatitis B virus infection in Italy is 10 per 100, 000
population, with most cases occurring in young adults. Vaccination against
hepatitis B has been compulsory since 1991 for all newborns and 12-year-olds. In
the Puglia region, this programme has reduced the incidence of hepatitis B from
7.4 per 100,000 population in 1990 to 2.4 per 100,000 population in 1996. The
number of notified cases of hepatitis B in Puglia decreased from 212 in 1992 to
73 in 1997. As 50% of these cases occurred in young adults, the main aim of the
current vaccination programme is to achieve high coverage rates among teenagers
and young adults within the next few years. Although the incidence of hepatitis A
is only about 5 per 100, 000 overall in Italy, Puglia is an area of intermediate
endemicity with a seroprevalence of antibodies to hepatitis A virus (anti-HAV) of
about 40% in 18-year-olds. The incidence of hepatitis A is up to 30 per 100,000
between the periodic outbreaks that occur every 2-4 years. Most notified cases
occur in adolescents and young adults. The last outbreak of about 11,000 cases of
hepatitis A in the Puglia region occurred in 1996-1997, mainly in the summer
months in towns with harbours or near the coast. The most important risk factor
was initially consumption of raw seafood, but later was personal contact,
probably between children. A vaccination programme against hepatitis A was
initiated in Puglia in 1997, aiming to vaccinate all infants of 15-18 months and
all 12-year-olds against hepatitis A. Infants receive monovalent hepatitis A
vaccine with the first dose of mumps/measles/rubella vaccine. Monovalent
hepatitis vaccine can be given with the second and third doses of hepatitis B
vaccine in 12-year-olds, but use of combined hepatitis A and B vaccine is
recommended to aid compliance and reduce the commitment of physician/nurse time.
Vaccination can be performed in school.
PMID- 10683559
TI - Cost-effectiveness of hepatitis A and B vaccination programme in Germany.
AB - A recent study in Germany analysed the epidemiological and economic impact of
combined hepatitis A and hepatitis B vaccination of all 1-15-year-olds or of all
11-15-year-olds projected over three periods of 10 years compared with a strategy
of non-vaccination. Vaccination of all 1-15-year-olds will achieve a reduction of
57,596 new hepatitis A cases with 7555 new infections remaining over 30 years.
Vaccination of all 11-15-year-olds will reduce the number of new hepatitis A
cases by 19,826, with 45,325 new cases remaining over 30 years. Vaccination of
all 1-15-year-olds will reduce the number of new hepatitis B cases by 45,820 with
7484 new cases remaining over 30 years, compared with vaccination of all 11-15
year-olds, which will reduce the number of new hepatitis B cases by 21,905 with
31,339 new cases remaining over 30 years. This significant reduction in the
number of new cases will lead to savings in treatment costs of DM 2.9 billion for
vaccination of 11-15-year-olds and of DM 5.1 billion for vaccination of 1-15-year
olds. The cost-effectiveness of vaccination ranges from costs of DM 90,000 for
each infection avoided to savings of DM 50, 000 for each case avoided. If
unreported cases are also taken into account and are equally distributed between
all age-groups, the savings per infection avoided over 30 years are DM 69,796 for
vaccination of 11-15-year-olds and DM 55,850 for vaccination of 1-15-year-olds.
Although the strategy of vaccinating 11-15-year-olds is the more cost-effective,
it leaves a large percentage of the population at high risk of hepatitis A virus
infection. The use of an initially more expensive combined hepatitis A and B
vaccine represents a cost-effective alternative to monovalent hepatitis B
vaccination and is more beneficial in terms of its epidemiological impact.
PMID- 10683561
TI - Discussion 4
PMID- 10683560
TI - Awareness campaigns: experience in Mexico.
AB - The current total of AIDS cases in Mexico is 37,000 of which 86% have occurred in
men. The major route of transmission is sexual. The campaign to prevent AIDS has
fallen into four phases, and has now been extended to other sexually transmitted
diseases, including hepatitis B. The first phase (1985-1989) was based around
question and answer brochures, which increased awareness but did not remove
misconceptions. A mass media campaign addressed these misconceptions and stressed
preventive measures. The campaign was halted by opposition to the promotion of
condom use on the grounds that it encouraged promiscuity. The second phase (1989
1992) used more conservative messages, but these were too obscure and failed to
reach the target audience. A poster campaign using popular lottery characters was
widely accepted. In the third phase (1992-1994), a combination of messages was
targeted at different populations, including parents and women, and general
public sympathy for social support for people with AIDS was encouraged. In the
fourth phase (1996-2000), a mass media campaign was aimed at teenagers, with
parents and teachers as support groups. The campaign was widened to include HBV
infection, and posters and brochures for teenagers were produced. These are
distributed as part of a collaboration with non-governmental organizations
providing sex education. The private medical sector is being encouraged to
provide facilities for hepatitis B vaccination. So far the campaign has only been
established in Mexico City, but it is hoped that this will be extended
nationwide. Hepatitis B vaccination has been recently included in the National
Immunization Programme for infants in the first year of life and it is officially
recommended for at-risk populations.
PMID- 10683563
TI - Discussion of the regional workshop conclusions
PMID- 10683562
TI - Introduction to the regional workshops.
PMID- 10683564
TI - P2 receptor-mediated inhibition of dopamine release in rat neostriatum.
AB - Axon terminal nucleotide P2 receptors mediating an inhibition of transmitter
release have, so far, been detected in various sympathetically innervated
tissues,(8,27) and on central noradrenergic,(14,26) glutamatergic(15) and
serotonergic neurons. (28) We have now investigated the effect of ATP and related
nucleotides on the release of endogenous dopamine from slices of rat neostriatum
using fast cyclic voltammetry. Mutual interactions between the two
neurotransmitters have been observed previously: ATP and related nucleotides
induce a release of dopamine in PC12 pheochromocytoma cells, a frequently used
model for sympathetic neurons;(10,22) they also increase the dopamine
concentration in rat brain measured by in vivo microdialysis(16,32) and stimulate
the uptake of dopamine by rat striatal synaptosomes.(3) Dopamine, in contrast,
facilitates activation of ligand-gated cation channels (i. e. P2X(2) receptors)
by ATP.(11,20) Here, we show that ATP and two of its analogues decrease the
electrically evoked release of endogenous dopamine in rat neostriatum. The
inhibitory effect of ATP is blocked by the P2 receptor antagonists suramin,
reactive blue 2 and cibacron blue 3GA. Suramin, in addition, partly prevents the
attenuation of dopamine release evoked by a single stimulus that follows a brief
train of high-frequency pulses.These findings suggest the existence of release
inhibiting P2 receptors on dopaminergic nerve terminals and indicate that
dopaminergic transmission in rat neostriatum might be modulated by an endogenous
P2 receptor ligand, presumably ATP.
PMID- 10683565
TI - Ceramide-induced sustained depression of synaptic currents mediated by ionotropic
glutamate receptors in the hippocampus: an essential role of postsynaptic protein
phosphatases.
AB - Ceramide, a sphingomyelin-derived second messenger, mediates cellular signals of
cytokines such as tumor necrosis factor-alpha that are rapidly produced in the
brain in response to vigorous neuronal activity and tissue injury. Using whole
cell patch-clamp recordings, the present study examined whether ceramide
modulated excitatory postsynaptic currents mediated by ionotropic glutamate
receptors in CA1 pyramidal neurons of rat hippocampal slices. Application of N
acetyl-D-sphingosine, a synthetic cell-permeable ceramide analog, promptly
produced a slight increase of excitatory postsynaptic current amplitude lasting
for about 3 min. However, this transient enhancement was followed by a profoundly
delayed-onset, sustained depression of synaptic excitatory postsynaptic currents
in a concentration-dependent fashion (1-30 microM). This ceramide-induced
sustained depression was not associated with changes in paired-pulse
facilitation, a phenomenon resulting from an alteration of presynaptic
transmitter release. Dihydro-N-acetyl-D-erythro-sphingosine (10 microM), an
inactive analog of N-acetyl-D-sphingosine, did not affect synaptic excitatory
postsynaptic currents, indicating the specificity of N-acetyl-D-sphingosine's
action. The induction of ceramide-induced sustained depression was primarily
dependent on the activation of postsynaptic protein phosphatases, being
considerably blocked by loading 30 nM okadaic acid (a potent inhibitor of protein
phosphatases 1 and 2A) into neurons. In addition, following a stable
establishment of ceramide-induced sustained depression, a protocol for inducing
long-term depression caused no additional decreases in excitatory postsynaptic
current amplitude, and vice versa. The study suggests that ceramide induces a
long-term depressed modulation on synaptic transmission mediated by ionotropic
glutamate receptors in the hippocampus, possibly through the activation of
postsynaptic protein phosphatases 1 and 2A. In addition, ceramide-induced
sustained depression seems to share some common mechanisms with long-term
depression, such as the cascades of events resulting from the activation of
protein phosphatases. Collectively, the long-term depressed modulation of
ceramide on ionotropic glutamate receptor-mediated functions may be particularly
important in various physiological and/or pathological conditions, in which the
ceramide signaling pathway is activated in the mammalian brain.
PMID- 10683566
TI - Long-term potentiation induction--a synaptic catch mechanism released by
extracellular phosphorylation.
AB - The best understood form of long-term potentiation in hippocampal CA1 neurons is
induced by activation of the N-methyl-D-aspartate receptor complex and subsequent
activation of the intracellular second messenger systems. In addition to this
intracellular mechanism, long-term potentiation can also be induced by an
extracellular mechanism involving phosphorylation by ATP-ecto-protein kinase. In
the present study, we hypothesize that a putative blocking molecule of the
formation of long-term potentiation exists on the synaptic membrane, and examine
whether ecto-protein kinases play a role in the block of long-term potentiation
by phosphorylating the ecto-domains of this molecule in CA1 neurons of guinea-pig
hippocampal slices. Long-term potentiation was induced by theta burst stimulation
whether or not the test input was delivered to the CA1 neurons following burst
stimulation. However, 5 microM K-252b, an ecto-protein kinase inhibitor, only
blocked the induction of long-term potentiation when the test input was delivered
during a 30-min period following burst stimulation. The results suggest that the
process of formation of long-term potentiation continues independently of test
synaptic input, while the block of long-term potentiation results from a
combination of an interruption of the ATP-ecto-protein kinase-dependent processes
and continued test synaptic input after burst stimulation. This block of long
term potentiation, which should be released by activation of ATP-ecto-protein
kinase, is suggested to act as a "safety catch" for synaptic plasticity in
hippocampal CA1 neurons.
PMID- 10683567
TI - Differential regulation of Ca(2+)-calmodulin stimulated and Ca(2+)-insensitive
adenylyl cyclase messenger RNA in intact and denervated mouse hippocampus.
AB - The Ca(2+)-calmodulin stimulated AC1 and Ca(2+)-insensitive AC2 are major
isoforms of adenylyl cyclase, playing an important role in synaptic plasticity in
the mammalian brain. We studied the pattern of expression of AC1 and AC2 genes in
the hippocampus of C57BL/6 mice. We found that there were differences in their
patterns of distribution in the dentate gyrus. AC1 messenger RNA was detected
both in the dentate granule cell bodies and the corresponding molecular field
whereas AC2 messenger RNA was preferentially distributed in the dentate granule
cell layer, suggesting that AC1 and AC2 messenger RNA are differentially
regulated in the dentate gyrus. In order to examine the regulation of AC1 and AC2
expression in response to synaptic deafferentation and reinnervation, the
distribution patterns of the two AC messenger RNA in the hippocampal fields and
the parietal cortex were analysed 2, 5, 9 and 30 days following an unilateral
entorhinal cortex lesion. Interestingly, we found significantly reduced levels of
AC1 hybridization signal following the lesion whereas the level of AC2 messenger
RNA remained unaffected in all lesioned groups. The changes in AC1 messenger RNA
were transient, with a maximal reduction at five days postlesion, and were
restricted to the granule cell bodies and stratum moleculare of the deafferented
dentate gyrus. No significant change in AC1 messenger RNA levels was detected in
other hippocampal fields nor for any other postlesion times studied. These
findings suggest that, at least in the dentate gyrus, messenger RNA for AC1 and
AC2 might be differentially compartmentalized in cell bodies and dendritic
fields. The activity-dependent regulation of AC1 messenger RNA levels by afferent
synapses may provide an elegant mechanism for achieving a selective local
regulation of AC1 protein, close to its site of action.
PMID- 10683568
TI - Immunohistochemical and neurochemical correlates of learning deficits in aged
rats.
AB - This study examined whether cholinergic and monoaminergic dysfunctions in the
brain could be related to spatial learning capabilities in 26-month-old, as
compared to three-month-old, Long-Evans female rats. Performances were evaluated
in the water maze task and used to constitute subgroups with a cluster analysis
statistical procedure. In the first experiment (histological approach), the first
cluster contained young rats and aged unimpaired rats, the second one aged rats
with moderate impairment and the third one aged rats with severe impairment. Aged
rats showed a reduced number of choline acetyltransferase- and p75(NTR)-positive
neurons in the nucleus basalis magnocellularis, and choline acetyltransferase
positive neurons in the striatum. In the second experiment (neurochemical
approach), the three clusters comprised young rats, aged rats with moderate
impairment and aged rats with severe impairment. Alterations related to aging
consisted of reduced concentration of acetylcholine, norepinephrine and serotonin
in the striatum, serotonin in the occipital cortex, dopamine and norepinephrine
in the dorsal hippocampus, and norepinephrine in the ventral hippocampus. In the
first experiment, there were significant correlations between water maze
performance and the number of; (i) choline acetyltransferase- and p75(NTR)
positive neurons in the nucleus basalis magnocellularis; (ii) choline
acetyltransferase-positive neurons in the striatum and; (iii) p75(NTR)-positive
neurons in the medial septum. In the second experiment, water maze performance
was correlated with the concentration of; (i) acetylcholine and serotonin in the
striatum; (ii) serotonin and norepinephrine in the dorsal hippocampus; (iii)
norepinephrine in the frontoparietal cortex and; (iv) with other functional
markers such as the 5-hydroxyindoleacetic acid/serotonin ratio in the striatum,
3,4-dihydroxyphenylacetic acid/dopamine ratio in the dorsal hippocampus, 5
hydroxyindoleacetic acid/serotonin and homovanillic acid/dopamine ratios in the
frontoparietal cortex, and 3,4-dihydroxyphenylacetic acid/dopamine ratio in the
occipital cortex. The results indicate that cognitive deficits related to aging
might involve concomitant alterations of various neurochemical systems in several
brain regions such as the striatum, the hippocampus or the cortex. It also seems
that these alterations occur in a complex way which, in addition to the loss of
cholinergic neurons in the basal forebrain, affects dopaminergic, noradrenergic
and serotonergic processes.
PMID- 10683569
TI - Apolipoprotein E-deficient mice are not more susceptible to the biochemical and
memory deficits induced by nucleus basalis lesion.
AB - We investigated whether the nucleus basalis lesion induced by quisqualic acid was
associated with a more severe impairment of spatial navigation in a water maze, a
greater reduction in frontal choline acetyltransferase activity and decrease in
the number of choline acetyltransferase-positive neurons in the nucleus basalis
in apolipoprotein E-deficient mice than in control mice. We also studied the
effect of ageing on water maze spatial navigation and cortical choline
acetyltransferase activity in 16-month-old control and apolipoprotein E-deficient
mice. We found that the lesion decreased choline acetyltransferase-positive
neurons in the nucleus basalis and frontal choline acetyltransferase activity
equally in control and apolipoprotein E-deficient mice. The nucleus basalis
lesion had no effect on the initial acquisition in the water maze in control and
apolipoprotein E-deficient mice after 25 or 106 days of recovery. However, the
nucleus basalis lesion impaired the reversal learning in the water maze similarly
in both strains after 25 days of recovery, but had no effect after 106 days of
recovery. Finally, water maze spatial navigation and cortical choline
acetyltransferase activity were similar in old control and apolipoprotein E
deficient mice. These results suggest that young and old apolipoprotein E
deficient mice do not have impairments in cholinergic activity or spatial
navigation. Furthermore, apolipoprotein E deficiency does not increase the
sensitivity to cholinergic and spatial navigation deficits induced by lesioning
of the nucleus basalis with an excitatory amino acid and does not slow down the
behavioral recovery.
PMID- 10683570
TI - Muscarinic receptors depress GABAergic synaptic transmission in rat midbrain
dopamine neurons.
AB - The effects of muscarine and nicotine on evoked and spontaneous release of GABA
were studied using intracellular and whole-cell patch-clamp recordings from rat
midbrain dopamine neurons in an in vitro slice preparation. Muscarine (30 microM)
reversibly depressed the pharmacologically isolated inhibitory postsynaptic
potential evoked by local electrical stimulation. The maximal inhibition of the
inhibitory postsynaptic potential amplitude was 39.6+/-5%. This depressant effect
of muscarine was blocked by the M3/M1 receptor antagonist 4-diphenylacetoxy-N
methylpiperidine methiodide (100 nM), but was slightly affected by the M1/M3
receptor antagonist pirenzepine (1 microM). In addition, muscarine decreased the
frequency of the miniature synaptic currents without any effect on their
amplitude. Moreover, muscarine did not change the GABA-induced hyperpolarization,
indicating that its effect on the inhibitory postsynaptic potential is mediated
by presynaptic receptors. On the contrary, the cholinergic agonist nicotine did
not change the frequency or the amplitude of the spontaneous glutamatergic and
GABAergic synaptic currents. Our data indicate that a prevalent activation of
presynaptic M3 muscarinic receptors inhibits the GABA-mediated synaptic events,
while the activation of nicotinic receptors does not affect the release of
glutamate and GABA on midbrain dopamine neurons.
PMID- 10683571
TI - Oxidative stress during energy impairment in mesencephalic cultures is not a
downstream consequence of a secondary excitotoxicity.
AB - Past studies have shown that inhibiting energy metabolism with malonate in
mesencephalic cultures damages neurons by mechanisms involving N-methyl-D
aspartate receptors and free radicals. Overstimulation of N-methyl-D-aspartate
receptors is known to produce free radicals. This study was, therefore, carried
out to determine if N-methyl-D-aspartate receptor activation triggered by energy
impairment was a significant contributor to the oxidative stress generated during
energy inhibition. Exposure of mesencephalic cultures to malonate for the minimal
time required to produce toxicity, i.e. 6h, resulted in an increase in the efflux
of both oxidized and reduced glutathione, and a decrease in tissue levels of
reduced glutathione. In contrast, exposure to 1mM glutamate for 1h caused an
increased efflux of reduced glutathione, but no changes in intra- or
extracellular oxidized glutathione or intracellular reduced glutathione. Blocking
N-methyl-D-aspartate receptors with MK-801 (0.5 microM) during malonate exposure
did not modify malonate-induced alterations in glutathione status or free radical
generation as monitored by dihydrochlorofluorescein diacetate and
dihydrorhodamine 123 fluorescence. In contrast, the increase in dihydrorhodamine
fluorescence caused by glutamate was completely blocked by MK-801. Reduction of
tissue glutathione with a 24h pretreatment with 10 microM buthionine sulfoxamine,
as shown previously, greatly potentiated malonate-induced toxicity to dopamine
and GABA neurons, but had no potentiating effect on toxicity due to glutamate.
The findings indicate that although oxidative stress mediates damage due either
to energy deprivation or excitotoxicity, N-methyl-D-aspartate receptor over
stimulation does not contribute significantly to the oxidative stress that is
incurred during malonate exposure.
PMID- 10683572
TI - Role of climbing fibers in determining the spatial patterns of activation in the
cerebellar cortex to peripheral stimulation: an optical imaging study.
AB - The spatial patterns of activation in the rat cerebellar cortex evoked by
ipsilateral face stimulation were mapped using optical imaging based on the pH
sensitive dye, Neutral Red. The aims of the study were to characterize the
optical responses evoked by peripheral stimulation and test the hypothesis that
the resultant parasagittal banding is due to climbing fiber activation. In the
anesthetized rat Crus I and II of the cerebellar cortex were stained with Neutral
Red. Epi-fluorescent changes produced by a train of stimuli (5-10s and 4-20 Hz)
to the ipsilateral face were monitored in time using a fast, high resolution
charge-coupled device camera. The patterns of activation were quantified using a
two-dimensional fast Fourier transform analysis that removed signals with high
spatial frequencies and minimized the contribution of horizontal structural
elements (i.e. blood vessels). The dominant spatial pattern of activation evoked
by face stimulation was that of parasagittal bands. The bands were highly
frequency-dependent and were elicited most strongly by stimulus frequencies in
the range of 6-8 Hz. There was a large fall-off in the response for frequencies
above and below. The optical signal evoked by face stimulation built up over a
period of 10s and then gradually decayed. Within a folium the individual
parasagittal bands exhibited some frequency and temporal specificity. Stimulation
of the contralateral inferior olive also resulted in the activation of
parasagittal bands with characteristics similar to the bands evoked by face
stimulation, including a preferred stimulus frequency which peaked at 10 Hz.
Injection of lidocaine into the contralateral inferior olive blocked the
parasagittal bands evoked by ipsilateral face stimulation, while control
injections of saline had no effect. The results confirm that a parasagittal
banding pattern is a dominant feature of the functional architecture of the
cerebellar cortex. The parasagittal banding pattern observed with Neutral Red is
due primarily to the activation of climbing fiber afferents. The frequency tuning
of the responses, with the preference for peripheral stimuli of 6-8 Hz, is in
agreement with previous findings that the inferior olive is inherently rhythmic.
These observations support the hypothesis that inferior olivary neurons are
dynamically coupled into groups that activate parasagittal bands of Purkinje
cells in the cerebellar cortex. The frequency tuning also supports the hypothesis
that the climbing fiber system is involved with timing. Activation of this
afferent system may require stimuli with appropriate frequency content and
stimuli synchronized to the rhythmicity of the inferior olive.
PMID- 10683573
TI - A direct cerebrocerebellar projection in adult birds and rats.
AB - The rostral Wulst of birds, like the somatosensory cortex of mammals, receives
somatosensory information from the thalamus and projects to the brainstem and
spinal cord via a pyramidal-like tract. Using anterograde and retrograde tract
tracers, we show here, in adult zebra finches, that the rostral Wulst also
projects directly to the cerebellar cortex and deep nuclei. In the cortex, the
cerebrocerebellar fibers resemble neither mossy nor climbing fibers, but more
closely resemble the multilayer fibers shown to originate from the hypothalamus
in mammals. We also show that a sparse projection to the cerebellum from the
mammalian neocortex, originally thought to be lost during early development, is
present in the adult rat. Although the functional implications of these results
are obscure, they suggest a revision of the concept of the "cerebrocerebellar
system", which is generally considered to involve a pontine relay.
PMID- 10683574
TI - Apposition of neuronal elements containing nitric oxide synthase and glutamate in
the nucleus tractus solitarii of rat: a confocal microscopic analysis.
AB - The distribution of glutamate and neuronal nitric oxide synthase in the rat
nucleus tractus solitarii was investigated by double fluorescent
immunohistochemistry combined with confocal laser scanning microscopy. Cells and
fibers that exhibited neuronal nitric oxide synthase immunoreactivity alone,
glutamate immunoreactivity alone or both immunolabels were present in all
subnuclei of the nucleus tractus solitarii, but staining intensities differed
between the subnuclei. The percentages of double-labeled glutamate-immunoreactive
cells also differed between the subnuclei. The central subnucleus contained the
highest percentage of double-labeled glutamate-immunoreactive cells and the
medial subnucleus contained the lowest. The percentages of double-labeled
neuronal nitric oxide synthase-immunoreactive neurons likewise differed between
the subnuclei. The central subnucleus contained the highest percentage of double
labeled neuronal nitric oxide synthase-immunoreactive neurons and the commissural
subnucleus contained the lowest. Because of our interest in cardiovascular
regulation, the anatomical relationship between glutamate-immunoreactive and
neuronal nitric oxide synthase-immunoreactive fibers in the dorsolateral and
commissural subnuclei was further examined at higher magnification. Close
appositions were observed between neuronal nitric oxide synthase-immunoreactive
and glutamate-immunoreactive fibers, between double-labeled and glutamate
immunoreactive fibers, and between neuronal nitric oxide synthase-immunoreactive
and double-labeled fibers. We recognized that a single visual perspective might
cause labeled fibers that pass in close proximity to appear to make contact.
Therefore, we constructed three-dimensional images from serial optical sections
obtained from the dorsolateral and commissural subnuclei by means of a confocal
scanning microscope. Rotation of the three-dimensional images caused some fibers
that had seemed to be in close apposition to other structures to separate from
those structures. In contrast, some glutamate-immunoreactive and some neuronal
nitric oxide synthase-immunoreactive fibers remained in close apposition
regardless of the angle at which they were viewed. This study supports there
being an anatomical link between glutamatergic and nitroxidergic systems in the
nucleus tractus solitarii. Recognized physiological interactions between the two
systems could occur through such a link.
PMID- 10683575
TI - Fos expression is induced by increased nitric oxide release in rat spinal cord
dorsal horn.
AB - The relationship between exogenous or endogenous nitric oxide and c-fos, an
immediate-early gene which can further activate the production of other
substances in the central nervous system, was investigated in this study. We
found that Fos expression is increased after intradermal capsaicin injection,
which also leads to endogenous nitric oxide release in the spinal cord. The
increased Fos expression is distributed in neurons of the superficial layers and
lamina V of the dorsal horn on the side ipsilateral to the injection. The
increased Fos expression is blocked by N(G)-nitro-L-arginine methyl ester, a
nitric oxide synthase inhibitor, but not by its inactive isomer N(G)-nitro-D
arginine methyl ester. Fos expression was also increased following the perfusion
of 3-morpholino-sydnonimine, a nitric oxide donor, into the dorsal horn through a
microdialysis fiber. The increased Fos was distributed within 400 microm from the
edge of the microdialysis fiber. Although Fos expression was increased with 3
morpholino-sydnonimine perfusion compared to that seen with artificial
cerebrospinal fluid perfusion, there was still some Fos immunostaining in the
control sections. Following perfusion of artificial cerebrospinal fluid in the
spinal cord of rats pretreated with N(G)-nitro-L-arginine methyl ester, it was
found that Fos staining was reduced significantly compared to the control
sections from animals without N(G)-nitro-L-arginine methyl ester pretreatment.
These results suggest that nitric oxide helps mediate Fos expression induced by
an intradermal capsaicin injection. We conclude that both endogenous and
exogenous nitric oxide induce Fos expression. Involvement of nitric oxide in the
development of central sensitization may affect nociceptive processing by
increasing Fos expression. Since many other substances which are related to pain
mechanisms can be induced by Fos, it is suggested that nitric oxide may regulate
production of these substances through activation of Fos. Nitric oxide is not
only involved in the development of central sensitization, but is also involved
in the activation of control mechanisms affecting nociception.
PMID- 10683576
TI - Anticonvulsant A(1) receptor-mediated adenosine action on neuronal networks in
the brainstem-spinal cord of newborn rats.
AB - Membrane potential of ventral respiratory group neurons as well as inspiratory
related cranial (hypoglossal) and spinal (C(1)-Th(4)) nerve activities were
analysed in brainstem-spinal cord preparations from neonatal rats. Block of Cl(-)
mediated inhibition with bicuculline (plus strychnine) affected neither rhythmic
depolarizations nor spike discharge in 23 of 30 ventral respiratory group cells.
In the other seven neurons, block of inhibitory postsynaptic potentials evoked
pronounced depolarizations and spike discharge that was synchronous with seizure
like spinal nerve activity. Respiratory hypoglossal nerve activity persisted
after transection at the spinomedullary junction, whereas spinal rhythm was
blocked. After transection, the moderate bicuculline-evoked seizure-like
perturbation of hypoglossal nerve activity was abolished and rhythmic ventral
respiratory group neuron activity was not disturbed, whereas epileptiform
discharge persisted in spinal nerves. The seizure-like nerve activity and
depolarization of the minor subpopulation of perturbed ventral respiratory group
neurons were reversed by either adenosine or the A(1) adenosine receptor agonist
2-chloro-N(6)-cyclopentyladenosine. The A(2) receptor agonist CGS 21860 had no
effect. In control preparations, inspiratory nerve activity and membrane
potential fluctuations (29 of 35 cells) were not changed by adenosine, 2-chloro
N(6)-cyclopentyladenosine or CGS 21860. In the other six cells, adenosine evoked
a hyperpolarization (<10 mV) with no major change in input resistance. The
anticonvulsant effects of adenosine and 2-chloro-N(6)-cyclopentyladenosine were
antagonized by the A(1) adenosine receptor blocker 8-cyclopentyl-1,3
dipropylxanthine. After pre-incubation with 8-cyclopentyl-1,3-dipropylxanthine,
bicuculline also evoked seizure-like discharge in the hypoglossal nerve. The
results indicate that seizure-like spinal motor output of the respiratory network
upon block of Cl(-)-mediated inhibition is caused by disinhibition of spinal
neuronal networks with afferent connections to the ventral respiratory group.
Presynaptic A(1) adenosine receptors exert an anticonvulsant action on the
disinhibited spinal motor network, but have no depressing effect per se on the
isolated medullary respiratory network.
PMID- 10683577
TI - The kappa opioid receptor and dynorphin co-localize in vasopressin magnocellular
neurosecretory neurons in guinea-pig hypothalamus.
AB - The relationship between the cloned kappa opioid receptor, dynorphin, and the
neurohypophysial hormones vasopressin and oxytocin was analysed in the guinea-pig
hypothalamic magnocellular neurosecretory neurons. This analysis was performed in
order to understand better which population of neuroendocrine neurons in the
guinea-pig is modulated by kappa opioid receptors and its endogenous ligand
dynorphin. Extensive co-localization was observed between kappa opioid receptor
immunoreactivity and preprodynorphin immunoreactivity in neuronal cell bodies in
the paraventricular and supraoptic nuclei. Cells positive for either the kappa
opioid receptor or both the kappa opioid receptor and preprodynorphin were
restricted to the vasopressin expressing neuronal population and not found in the
oxytocin expressing neuronal population. The kappa opioid receptor and dynorphin
were examined in the posterior pituitary and both were found to be extensively
distributed. Staining for the kappa opioid receptor and dynorphin B co-localized
in posterior pituitary. In addition, immunogold electron microscopy confirmed
that kappa opioid receptor and dynorphin B immunoreactivity were found in the
same nerve terminals. Ultrastructural analysis also revealed that kappa opioid
receptor immunoreactivity was associated with both nerve terminals and
pituicytes. Within nerve terminals, kappa opioid receptor immunoreactivity was
often associated with large secretory vesicles and rarely associated with the
plasma membrane. Our data suggest that the cloned kappa opioid receptor may
directly modulate the release of vasopressin but not oxytocin in guinea-pig
hypothalamic magnocellular neurosecretory neurons and posterior pituitary.
Furthermore, we propose that this receptor is an autoreceptor in this system
because our results demonstrate a high degree of co-localization between kappa
opioid receptor and dynorphin peptide immunoreactivity in magnocellular nerve
terminals.
PMID- 10683578
TI - Reduction of voltage-dependent magnesium block of N-methyl-D-aspartate receptor
mediated current by in vivo axonal injury.
AB - The post-traumatic change of the voltage-dependent Mg(2+) block of N-methyl-D
aspartate response was investigated using nystatin perforated patch recording
mode under the voltage-clamp condition. Motor neurons of the dorsal motor nucleus
of vagus nerve were freshly dissociated from rat brain at 2h to 10 days after
receiving axonal crush injuries in vivo at the neck. The reduction of voltage
dependent Mg(2+) block of N-methyl-D-aspartate response became evident at more
than 12h after the injury, sustained for at least five days and recovered within
10 days. Other characteristics examined such as reversal potentials, the Hill
coefficient and EC(50) of N-methyl-D-aspartate-induced current were not affected
by axonal injury. The Mg(2+) block of N-methyl-D-aspartate response was not
affected at all by local application of colchicine onto the vagal axon in in vivo
condition, suggesting that axonal injury, but not the blockade of the axonal
flow, is responsible for the change of the sensitivity of N-methyl-D-aspartate
response to extracellular Mg(2+). In addition, the reduction of Mg(2+) block by
the nerve injury persisted regardless of the presence of protein kinase C
modulators, such as 10(-6)M chelerythrine and 10(-7)M calphostin C. Therefore
alteration of protein kinase C activity after axonal injury is not responsible
for the maintenance of the reduced Mg(2+) block. These findings suggest that
injured neurons acquire immature characteristics of plasticity with respect to
the sensitivity of N-methyl-D-aspartate receptors to extracellular Mg(2+) or a
long-term increase in the susceptibility to Ca(2+) excitotoxicity.
PMID- 10683579
TI - Cerebral vasodilatation induced by stimulation of the pterygopalatine ganglion
and greater petrosal nerve in anesthetized monkeys.
AB - Although brain cell viability depends largely on cerebral circulation, mechanisms
of blood flow control, such as autoregulation, or of the pathogenesis of
functionally impaired blood supply to brain regions, such as in cerebral
vasospasm after subarachnoid hemorrhage, have not been clearly defined. Our
recent studies support the hypothesis that nitric oxide, released from nitrergic
nerves, plays a crucial role as a neurotransmitter in vasodilating cerebral
arteries from primate and subprimate mammals. In the present study, we
demonstrated, by using arterial angiography, that electrical stimulation of the
pterygopalatine ganglion produced vasodilatation of ipsilateral cerebral arteries
of anesthetized Japanese monkeys. The response was abolished by intravenous
injections of N(G)-nitro-L-arginine, a nitric oxide synthase inhibitor.
Denervation of the ganglion elicited cerebral vasoconstriction, indicating that
vasodilator nerves from the vasomotor center were tonically active. Stimulation
of the greater petrosal nerve, upstream of the pterygopalatine ganglion, also
elicited cerebral vasodilatation, which was abolished by treatment with the
nitric oxide synthase inhibitor and with hexamethonium, indicating that the nerve
is in connection via synapses with the nitrergic nerve innervating cerebral
arteries. Endogenous nitric oxide released from the nerve may contribute to the
maintenance of blood flow in major cerebral arteries necessary to supply blood to
the different brain regions. Without this influence, cerebral arteries might be
constricted to the extent that blood flow is impeded. This is the first direct
evidence indicating an important role of nitric oxide liberated by pre- and
postganglionic nerve stimulation in the control of cerebral arterial tone in
primates.
PMID- 10683580
TI - Role of the axodendritic tree in the functioning of helix bursting neurons:
generation of pacemaker activity and propagation of action potentials along the
axon.
AB - The purpose of this study was to determine the role of the axodendritic tree in
the generation of bursting pacemaker activity in the identified Helix RPa1
neuron, which is homologous to the Aplysia R15 cell, and propagation of action
potentials along the axons. In doing so, I used recording of RPa1 neuron
electrical activity after cutting off the right or left parietovisceral
connections, the two-electrode voltage-clamp technique, registration of
electrical activity of visceral nerve containing RPa1 axon branches, isolation of
the RPa1 neuron and puff application of oxytocin on it. Cutting of the right (but
not left) parietovisceral connection in all cases (more than 15 preparations)
evoked complete disappearance of bursting pacemaker activity in the RPa1 neuron
and hyperpolarization of its membrane potential up to -65 to -67 mV. Such silent
state of the RPa1 neuron was maintained after its complete isolation from the
ganglion. The described cutting did not result in a change of bursting activity
of the pacemaker neuron V7 located in the visceral ganglion, although isolation
of the V7 neuron also eliminated its own activity. Puff application of oxytocin
(10 microM in a micropipette) on to the RPa1 neuron both after cutting the right
parietovisceral connection or isolation of the neuron from the ganglion resulted
in all cases (more than 10 cells) in transient depolarization with development of
beating, oscillatory or bursting activity. Voltage clamping of RPa1 soma in the
intact ganglion at a level close to zero membrane current sometimes, and, as a
rule, at a more depolarized level, revealed bursting-like oscillations of
membrane current, reflecting electrical bursting activity in the unclamped remote
region of a neuron, most likely in the dendritic tree. Voltage clamping of RPa1
soma possessing bursting activity reveals bursting-like oscillation of membrane
current and prevents propagation of corresponding axon action potentials in the
visceral nerve. Controversially, clamping of RPa1 soma possessing beating
activity exhibits a beating-like oscillation of membrane current and does not
prevent propagation of corresponding action potentials in the nerve. Within the
framework of the developed hypothesis that persistent bursting pacemaker activity
of the RPa1 neuron is due to a constant activation of its peptidergic synaptic
inputs [Kononenko N. I. (1993) Comp. Biochem. Physiol. 106A, 135-147], the
experimental results were interpreted in the manner that these synapses and,
correspondingly, the locus of electrical bursting activity generation, are
localized on the dendritic tree of the RPa1 neuron mainly or possibly exclusively
in the visceral ganglion. It is hypothesized that bursting and beating neuronal
activities are due to functioning of different loci of the dendritic tree,
regarding their electrical relations with axon branches.
PMID- 10683581
TI - Acute effects of capsaicin on gastrointestinal vagal afferents.
AB - Capsaicin is an important tool for investigation of thin afferent fibres, but its
acute effects on subtypes of vagal afferent endings are unknown. In the
gastrointestinal tract, these subtypes are: muscle endings (thought to be purely
tension sensitive), mucosal endings (sensitive to stroking and chemical stimuli)
and endings in the oesophagus with both properties. Acute capsaicin sensitivity
was investigated in ferrets using in vivo and in vitro methods. Single-fibre
activity was recorded from 63 vagal afferents: 12 Adelta-fibres, 15 C-fibres and
36 unclassified fibres with endings in the oesophagus (n=42), stomach (n=19) and
duodenum (n=2). Responses to capsaicin occurred independently of motility changes
and were therefore due to direct activation of the receptor ending. In the
oesophagus in vivo, two of 10 tension receptors and one of one mucosal receptor
responded to intraluminal application of 3.25 mM capsaicin. In the stomach and
duodenum, five of 14 tension receptors and two of four mucosal receptors
responded to close-systemic (32-164 nmol) capsaicin. In an in vitro gastro
oesophageal preparation, three of five tension, four of 21 mucosal and two of
eight tension/mucosal receptors responded to topical application of 1mM
capsaicin. Occurrence of responses was therefore unrelated to location of endings
and isolation of tissue. Responsiveness was also unrelated to conduction
velocity. Capsaicin caused desensitization of responses to further capsaicin
application in 37% of afferents. It additionally caused cross-desensitization to
mechanical stimuli, which was also seen in afferents that did not respond
directly to capsaicin. In conclusion, capsaicin acutely activates all subtypes of
gut vagal afferents in vivo and in vitro, although responsiveness is restricted
to 30% of fibres and follows no specific pattern. Acute desensitization may be
induced with or without a response.
PMID- 10683582
TI - Dexamethasone pre-treatment interferes with apoptotic death in glioma cells.
AB - Glucocorticoids are known to influence the ability of cells to undergo apoptosis,
directly inducing apoptosis in thymocytes while inhibiting it in hepatoma and
carcinoma cells. Dexamethasone, a synthetic glucocorticoid, is reported to induce
partial resistance to certain anticancer drugs in glioma cell lines. In the
present study, the effect of dexamethasone on apoptosis of glioma and astrocytoma
cell lines was investigated. Exposure of D384 human astrocytoma and C6 rat glioma
cells to staurosporine induced apoptosis as judged by the formation of condensed
nuclei and caspase activation. Pre-treatment of cells with dexamethasone caused a
reduction in staurosporine-induced apoptosis. In addition, dexamethasone also
conferred protection against the induction of apoptosis by anticancer agents
including camptothecin and etoposide. The protective effect of dexamethasone was
dose and time dependent, with maximal protection obtained with concentrations
equal to or greater than 100 nM and a pre-incubation period of at least 24h. The
earliest significant inhibition was seen with a pre-incubation period of 8h. Co
treatment with the glucocorticoid receptor antagonist RU38486 abolished the
effect of dexamethasone, indicating that the protection due to dexamethasone is
mediated via this receptor. Dexamethasone was found to induce a time-dependent up
regulation of Bcl-x(L) protein expression. However, the ability of cytochrome
c/dATP to activate the caspase cascade in cytosolic extracts of D384 cells was
unaffected by prior exposure of the cells to dexamethasone (1 microM) for 48 h.
In conclusion, dexamethasone inhibits the induction of apoptosis in astrocytoma
cells, probably via an up-regulation of Bcl-x(L), which could prevent cytochrome
c release from mitochondria and subsequent caspase activation. Since
glucocorticoids are often used in the treatment of gliomas to relieve cerebral
oedema, the inhibition of apoptosis by these compounds could potentially
interfere with the efficacy of chemotherapeutic drugs.
PMID- 10683583
TI - Microglia in organotypic hippocampal slice culture and effects of hypoxia:
ultrastructure and lipocortin-1 immunoreactivity.
AB - Lipocortin-1 immunocytochemistry was used to study the various cell forms of
microglia that appear during organotypic hippocampal tissue culture, as well as
in the in vitro toxic hypoxia model. Antibodies against lipocortin-1 identified
activated and phagocytic cells that were abundant in a slice after the plating of
a culture: cells of the intermediate form at the later time-points of culturing,
resting ramified microglia beginning from the seventh day of culturing, as well
as activated and phagocytic cells that appeared in the slice after experimental
toxic hypoxia induced by potassium cyanide treatment. Lipocortin-1-positive
microglia cell forms corresponded well to the description of the microglia in
vivo, and the morphology of microglia corresponded to the circumstances under
which these cells were observed in slice cultures. Electron microscopic studies
have demonstrated, for the first time, that microglia in organotypic slice
culture preserve morphological features typical of different microglial forms in
vivo, as well as specific contacts and interactions with the other neural tissue
elements. After experimental toxic hypoxia, rapid changes in microglial
ultrastructure and localization were observed, reminiscent of in vivo models of
ischaemia. In conclusion, observations of microglial morphology and behaviour
allow us to suggest that microglia in the organotypic culture preserve their
essential characteristic features and properties, thus providing an important
model system for studying the structure and function of these cells.
PMID- 10683584
TI - Neurotrophin regulation of sodium and calcium channels in human neuroblastoma
cells.
AB - Neurotrophins, acting through tyrosine kinase family genes, are essential for
neuronal differentiation. The expression of tyrosine kinase family genes is
prognostic in neuroblastoma, and neurotrophins reduce proliferation and induce
differentiation, indicating that neuroblastomas are regulated by neurotrophins.
We tested the effects of nerve growth factor and brain-derived neurotrophic
factor on Na(+) and Ca(2+) currents, using the whole-cell patch-clamp technique,
in human neuroblastoma NB69 cells. Control cells exhibited a slow tetrodotoxin
resistant (IC(50)=98 nM) Na(+) current and a high-voltage-activated Ca(2+)
current. Exposure to nerve growth factor (50 ng/ml) and/or brain-derived
neurotrophic factor (5 ng/ml) produced the expression of a fast tetrodotoxin
sensitive (IC(50)=10 nM) Na(+) current after day 3, and suppressed the slow
tetrodotoxin-resistant variety. The same type of high-voltage-activated Ca(2+)
current was expressed in control and treated cells. The treatment increased the
surface density of both Na(+) and Ca(2+) currents with time after plating, from
17 pA/pF at days 3-5 and 1-5 to 34 and 30 pA/pF after days 6-10, respectively.
Therefore, both nerve growth factor and brain-derived neurotrophic factor, acting
through different receptors of the tyrosine kinase family and also possibly the
tumor necrosis factor receptor-II, were able to regulate differentiation and the
expression of Na(+) and Ca(2+) channels, partially reproducing the modifications
induced by diffusible astroglial factors. We show that neurotrophins induced
differentiation to a neuronal phenotype and modified the expression of Na(+) and
Ca(2+) currents, partially reproducing the effects of diffusible astroglial
factors.
PMID- 10683585
TI - c-Jun/AP-1 (N) directed antibodies cross-react with "apoptosis-specific protein"
which marks an autophagic process during neuronal apoptosis.
PMID- 10683587
TI - Gerrits M. A. F. M., wiegant V. M. And van ree J. M. (1999). Endogenous opioids
implicated in the dynamics of experimental drug addiction: an in vivo
autoradiographic analysis. Neuroscience 89, 1219-1227
PMID- 10683586
TI - c-Jun/AP-1 (N) expression and apoptosis.
PMID- 10683589
TI - Systematic reviews of wound care management: (2). Dressings and topical agents
used in the healing of chronic wounds.
PMID- 10683591
TI - Factors that limit the quality, number and progress of randomised controlled
trials.
PMID- 10683592
TI - Antimicrobial prophylaxis in total hip replacement: a systematic review.
PMID- 10683593
TI - Health promoting schools and health promotion in schools: two systematic reviews.
PMID- 10683594
TI - Economic evaluation of a primary care-based education programme for patients with
osteoarthritis of the knee.
PMID- 10683597
TI - Obesity reduction through lifestyle modification.
AB - Obesity is a worldwide public health problem. One in three Canadians is
overweight, a prevalence that is already high and increasing. Moreover, 54% of
men and 37% of Canadian women are characterized as abdominally obese, the
phenotype that is strongly associated with cardiovascular disease and type II
diabetes. These observations underscore the importance of considering the
efficacy of methods commonly used to reduce total and abdominal obesity. These
strategies include a decrease in energy intake (diet), an increase in energy
expenditure (exercise), or pharmacological intervention. The combination of diet
and exercise is more commonly prescribed, with pharmacological intervention
suggested only when lifestyle changes fail to achieve weight loss. The aim of
this report is to review current knowledge regarding the influence of diet and
exercise as treatment strategies for obesity reduction and provide
recommendations for attaining and maintaining a healthy weight. The importance of
diet composition in the treatment of obesity is also considered.
PMID- 10683598
TI - Exercise and training in women, Part I: Influence of gender on exercise and
training responses.
AB - Exercise and training responses in women are briefly reviewed. Part I of the
paper considers the influence of gender on such responses. The average woman has
a smaller inherent aerobic power and less muscular strength than a man,
reflecting sociocultural influences, physical size, body composition, and
hormonal milieu. Nevertheless, the best-trained women can out-perform sedentary
men. The handicap of the average woman is offset by a lighter body mass and a
tendency to metabolize fat rather than carbohydrate during exercise. A lack of
anabolic hormones may limit training increases of muscle bulk in the female. A
low initial fitness may enhance the scope for training tolerance, but it also
limits tolerance of conditioning. Nevertheless, women seem less vulnerable than
men to exercise-induced sudden death and overtraining. Part II of the review
considers the influence of the menstrual cycle and pregnancy upon exercise and
training responses. Physical activity programmes for young women should take
account of possible pregnancy. Potential dangers to the foetus include an
excessive rise of core body temperature, a decrease of maternal blood sugar, and
foetal hypoxia. Nevertheless, regular moderate exercise generally has a
favourable impact upon pregnancy outcomes.
PMID- 10683599
TI - Exercise and training in women, Part II: Influence of menstrual cycle and
pregnancy.
AB - This part of the review considers the impact of the menstrual cycle and pregnancy
upon exercise performance, together with the implications of continued, regular
exercise for the developing foetus. Specific issues that are covered include
changes in physical performance over the menstrual cycle; the impact of training
on the menstrual cycle; a need for awareness of potential pregnancy; alterations
in fitness, performance, circulatory, respiratory and metabolic function during
pregnancy; potential hazards to the foetus from hyperthermia and hypoxia; a
recommended physical activity programme for the pregnant woman; and the impact of
continued exercise upon pregnancy outcomes.
PMID- 10683600
TI - The efficacy of SPORT as a dietary supplement on performance and recovery in
trained athletes.
AB - This study investigated the efficacy of SPORT (a popular dietary supplement) in
improving performance and assisting recovery in 9 trained athletes. In a double
blind, crossover experiment, subjects ran at workloads of 60 and 80% of peak
oxygen uptake (Peak VO2) for 5 min each with 5 min recovery after each bout and
at 100% Peak VO2 until exhaustion. Two capsules of either SPORT or a gelatin
placebo were administered 1 hr prior to exercise and immediately after each
workload. Heart rate (HR) and blood lactate (BLa) were measured at 1 hr prior to
exercise, immediately after the 100% exercise bout and at 5, 10, 20, and 45 min
during recovery. No significant differences between treatments on HR and BLa
measures at any of the 6 time periods, or on subjects' time to exhaustion were
found. Under the conditions of this experimental design, SPORT had no beneficial
effects on performance or recovery in trained athletes.
PMID- 10683601
TI - The acute effects of androstenedione supplementation in healthy young males.
AB - We examined the effects of androstenedione supplementation on the hormonal
profile of 10 males and its interaction with resistance exercise. Baseline
testosterone, luteinizing hormone, estradiol, and androstenedione concentrations
were established by venous sampling at 3 hr intervals over 24 hr. Subjects
ingested 200 mg of androstenedione daily for 2 days, with second and third day
blood samples. Two weeks later, they ingested androstenedione or a placebo for 2
days, in a double-blind, cross-over design. On day 2, they performed heavy
resistance exercise with blood sampled before, after, and 90 min post. The
supplement elevated plasma androstenedione 2--3-fold and luteinizing hormone
approximately 70% but did not alter testosterone concentration. Exercise elevated
testosterone, with no difference between conditions. Exercise in the supplemented
condition significantly elevated plasma estradiol by approximately 83% for 90
min. Androstenedione supplementation, thus, is unlikely to provide male athletes
with any anabolic benefit and, with heavy resistance exercise, elevates estrogen.
PMID- 10683602
TI - Immunocytochemical localization of the metabotropic glutamate receptor mGluR4a in
the piriform cortex of the rat.
AB - This study evaluates the localization of the metabotropic glutamate receptor
mGluR4a in the piriform cortex of rats using preembedding immunocytochemical
methods. At the light microscopic level, punctate labeling was evident in layers
Ia and Ib of the piriform cortex, and immunolabeled fibers were present in layers
II and III. Following bilateral destruction of the olfactory bulb, the density of
labeled puncta in layer Ia decreased. These results suggest that the receptor is
present on the terminals of the lateral olfactory tract (LOT). Electron
microscopic evaluation of layers Ia and Ib revealed that mGluR4a was localized in
synaptic terminals in layers Ia and Ib. The terminals had clear, round synaptic
vesicles and terminated on asymmetric synapses on dendritic spines and shafts.
There was also immunolabeling of some dendritic profiles in layers Ia and Ib that
were postsynaptic to unlabeled presynaptic terminals. These observations suggest
that mGluR4a is present on presynaptic terminals in the layers of the piriform
cortex that receive LOT and associational synapses. This is the same area in
which previous studies have revealed the presence of mGluR7 and mGluR8,
suggesting that all three receptors may be colocalized.
PMID- 10683603
TI - Expression of L1 and TAG-1 in the corticospinal, callosal, and hippocampal
commissural neurons in the developing rat telencephalon as revealed by retrograde
and in situ hybridization double labeling.
AB - In the telencephalon, the corticospinal (CS), callosal, and hippocampal
commissural neurons are the major types of neurons that have axons crossing the
midline of the brain. To understand the mechanisms involved in crossing the
midline structure and to examine whether the expression patterns of L1 and TAG-1
in the commissural neurons are similar to those in the spinal cord, we
investigated L1 and TAG-1 expression in these neurons in rats by using a double
labeling technique involving retrograde labeling and in situ hybridization.
Expression of L1 messenger RNA was detected in the retrogradely labeled CS
projection neurons by 1,1;-dioctadecyl-3,3, 3;,3;-tetramethylindocarbocyanine
perchlorate (DiI) injection into the pons at embryonic day (E) 19, but expression
of TAG-1 messenger RNA was not detected in these neurons. Also, after their axons
crossed the pyramidal decussation, continued expression of L1 but no expression
of TAG-1 in the CS projection neurons was shown by an additional double-labeling
experiment involving DiI injection into the spinal cord at postnatal day (P) 1.
An immunohistochemical study showed that L1 was continuously present in each
level of the CS tract at E21 and P3, but TAG-1 immunoreactivity was not found in
any level at any stage. Finally, we examined the expression of L1 and TAG-1
messenger RNAs in the callosal and hippocampal commissure neurons after their
axons had crossed the midline by using the double-labeling technique. In both
cases, hybridization signals of the L1 and TAG-1 messenger RNAs were observed in
the retrogradely labeled neurons at P3. These results suggest that the roles of
L1 and TAG-1 in the formation of the commissures in the forebrain are different
from their roles in the spinal cord.
PMID- 10683604
TI - Retinoid-dependent gene expression regulates early morphological events in the
development of the murine retina.
AB - Endogenous retinoids have been implicated in the axial patterning of the
embryonic vertebrate retina; however, no studies have directly examined how
asymmetric retinoid-dependent gene expression regulates early morphological
events in the development of the retina. Here we used a line of indicator mice
that possess a retinoid-dependent transgene to examine the relationship between
retinoic acid (RA)-dependent gene expression and events occurring during early
eye morphogenesis, such as the closure of the optic disc. We found that retinoid
regulated gene expression shifts along the dorsal/ventral axis of the embryonic
retina; at embryonic day (E) E11.5 transgene expression is restricted to the
neuroepithelium in dorsal retina, and by E14.5 only immature cells located in
ventral retina and the dorsal retinal margins demonstrate transgene activation.
By manipulating RA levels, we were not only able to systemically alter RA
dependent gene expression along the dorsal/ventral axis, but also to affect
retinal morphology. In particular, reducing RA availability resulted in the
abnormal closure of the optic fissure. These results indicate that asymmetric
levels of RA regulate early RA-dependent gene expression in the eye and
demonstrate that the normal pattern of retinoid-dependent gene transcription
along the dorsal/ventral axis is critical for the proper development of the
vertebrate retina.
PMID- 10683605
TI - Sensory neuroanatomy of a passively ingested nematode parasite, Haemonchus
contortus: amphidial neurons of the first stage larva.
AB - When infective larvae of Haemonchus contortus (a highly pathogenic, economically
important, gastric parasite of ruminants) are ingested by grazing hosts, they are
exposed to environmental changes in the rumen, which stimulate resumption of
development. Presumably, resumption is controlled by sensory neurons in sensilla
known as amphids. Neuronal function can be determined by ablation of specifically
recognized neurons in hatchling larvae (L1) in which neuronal cell bodies are
easily visualized using differential interference microscopy. Using three
dimensional reconstructions from electron micrographs of serial transverse
sections, amphidial structure of the L1 is described. Each amphid of H. contortus
is innervated by 12 neurons. The ciliated dendritic processes of 10 neurons lie
in the amphidial channel. Three of these end in double processes, resulting in 13
sensory cilia in the channel. One process, that of the so-called finger cell,
ends in a number of digitiform projections. Another specialized dendrite enters
the amphidial channel, but leaves it to end within the sheath cell, a hollow,
flask-shaped cell that forms the base of the amphidial channel. Although not
flattened, this process is otherwise similar to the wing cells in Caenorhabditis
elegans; we consider it AWC of this group. Two other neurons, ASA and ADB, appear
to be homologs of wing cells AWA and AWB in C. elegans, although they end as
ciliated processes in the amphidial channel, rather than as flattened endings
seen in C. elegans. Each of the 12 amphidial neurons was traced to its cell body
in the lateral ganglion, posterior to the worm's nerve ring. The positions of
these bodies were similar to their counterparts in C. elegans; they were named
accordingly. A map for identifying the amphidial cell bodies in the living L1 was
prepared, so that laser microbeam ablation studies can be conducted. These will
determine which neurons are involved in the infective process, as well as others
important in establishing the host-parasite relationship.
PMID- 10683606
TI - Glutamate-induced cobalt uptake reveals non-NMDA receptors in rat taste cells.
AB - Taste receptor cells are chemical detectors in the oral cavity. Taste cells form
synapses with primary afferent neurons that convey the gustatory information to
the central nervous system. Taste cells may also synapse with other taste cells
within the taste buds. Furthermore, taste cells may receive efferent connections.
However, the neurotransmitters at these synapses have not been identified.
Glutamate, a major excitatory neurotransmitter in other sensory organs, might act
at synapses in taste buds. We used a cobalt staining technique to detect Ca(2+)
permeable glutamate receptors in taste buds and thus establish whether there
might be glutamatergic synapses in gustatory end organs. When 500 microm slices
of foliate and vallate papillae were briefly exposed to 1 mM glutamate in the
presence of CoCl(2), a subset of spindle-shaped taste cells accumulated Co(2+).
Cobalt uptake showed concentration-dependency in the range from 10 microm to 1 mM
glutamate. Interestingly, higher glutamate concentrations depressed cobalt
uptake. This concentration-response relation for cobalt uptake suggests that
synaptic glutamate receptors, not receptors for glutamate taste, were activated.
Sensory axons and adjacent non-sensory epithelium were not affected by these
procedures. Glutamate-stimulated cobalt uptake in taste cells was antagonized by
the non-NMDA receptor antagonist CNQX. Depolarization with 50 mM K(+) and
application of NMDA (300 microM) did not increase the number of stained taste
cells. This pharmacological characterization of the cobalt uptake suggests that
non-NMDA receptors are present in taste cells. These receptors might be
autoreceptors at afferent synapses, postsynaptic receptors of a putative efferent
system, or postsynaptic receptors at synapses with other taste cells.
PMID- 10683607
TI - Focal denervation alters cellular phenotypes and survival in the developing rat
olfactory bulb.
AB - Several studies have demonstrated that contact between the olfactory nerve and
the forebrain is critical for normal olfactory bulb development. Removal of the
embryonic olfactory placode results in a failure of the olfactory bulb to form,
as well as causing other forebrain malformations. The current study introduces a
technique that permits removal of contact between specific regions of the
olfactory nerve and the bulb early in development, without causing damage to
other brain regions, and without removing the peripheral olfactory organ. The
manipulation, which involves insertion of a small Teflon chip between the
cribriform plate and the bulb, prohibits growth of new axons into the "shadow"
region behind the implant. Focal denervation of the olfactory bulb causes a
decrease in bulb and layer sizes, a reduction in mitral cell number, and changes
to bulb architecture. Using a battery of antibodies (OMP, MAP2, TuJ1, calretinin,
calbindin, parvalbumin, TH, and GAD), we further demonstrated that 1) focal
denervation alters the relationship between the olfactory nerve and the bulb, 2)
the fine structure of cells in denervated regions is disrupted, and 3) cellular
phenotypes change in response to loss of afferent contact. These results suggest
that contact between the olfactory nerve and the bulb is important for
maintaining bulb architecture and cell survival, structure, and phenotype. They
also point to focal denervation as a useful technique for examining the role of
neural contact in olfactory development and maintenance of the central nervous
system.
PMID- 10683609
TI - Proliferation and programmed cell death of neuronal precursors in the mushroom
bodies of the honeybee.
AB - We have studied proliferation and programmed cell death in the brain of the
honeybee during metamorphosis. DNA fragmentation detection using the TUNEL method
combined with 5-bromodeoxyuridine incorporation experiments reveal that in the
mushroom bodies neurogenesis is terminated by extensive apoptosis. Proliferation
of mushroom body neuroblasts is active until the fourth day of pupal development,
ceasing abruptly within 1 day after the onset of apoptosis in the mushroom body
proliferative clusters. Inside the mushroom bodies, apoptosis spreads from the
apical ends of proliferative clusters, beneath the brain's surface, toward the
basal ones. The distributions of apoptotic cells and those in the S phase of the
cell cycle overlap significantly. Electron microscopic analysis gives further
evidence that mushroom body neuroblasts themselves undergo programmed cell death.
We suggest that programmed cell death may be the main factor controlling the
final number of Kenyon cells produced during metamorphosis. The overlap in time
and space between proliferation and apoptosis raises the question of whether the
neuronal precursors switch to programmed cell death during the progression of the
cell cycle, or afterwards.
PMID- 10683608
TI - Segregation of serotonin 5-HT2A and 5-HT3 receptors in inhibitory circuits of the
primate cerebral cortex.
AB - An emerging concept of cortical network organization is that distinct segments of
the pyramidal neuron tree are controlled by functionally diverse inhibitory
microcircuits. We compared the expression of two serotonin receptor subtypes, the
G-protein-coupled 5-hydroxytryptamine2A receptors and the ion-channel gating 5
HT3 receptors, in cortical neuron types, which control these microcircuits. Here
we show, using light and electron microscopic immunocytochemical techniques, that
5-HT2A receptors are segregated from 5-HT3 receptors in the macaque cerebral
cortex. 5-HT2A receptor immunolabel was found in pyramidal cells and also in
GABAergic interneurons known to specialize in the perisomatic inhibition of
pyramidal cells: large and medium-size parvalbumin- and calbindin-containing
interneurons. In contrast, 5-HT3 label was only present in small GABA-, substance
P receptor-, and calbindin-containing neurons and in medium-size calretinin
containing neurons: interneurons known to preferentially target the dendrites of
pyramidal cells. This cellular segregation indicates a serotonin-receptor
specific segmentation of the GABAergic inhibitory actions along the pyramidal
neuron tree.
PMID- 10683610
TI - Synapse distribution of olfactory interneurons in the procerebrum of the snail
Helix aspersa.
AB - The procerebrum is believed to be important for processing olfactory information
and storing olfactory memories in terrestrial pulmonate molluscs. Previous
results have demonstrated that the procerebral cell population is morphologically
heterogeneous. In the present study, serial sections and electron microscopy were
used to investigate differences in synapse distributions. The results demonstrate
that procerebral neurons with different sites of arborization have distinct
patterns of synapse distribution that probably reflect different functional
contributions to the olfactory pathway. Cells that have all their arborizations
in the procerebrum, but none in the internal mass, have multiple large
varicosities that are specialized for output. On the other hand, cells that
arborize in the internal mass or outside the procerebrum have mostly input
synapses proximal to the soma and mostly output synapses in the terminal region
of the neurites. These cells appear to transmit information from the procerebral
cell body mass to other central nervous system regions, e.g., the internal mass
and the mesocerebrum. The implications of these data are twofold. Firstly, the
procerebrum directly participates in distributing processed olfactory information
to more central regions of the nervous system. Secondly, the procerebral neuronal
population may be divisible into two subgroups: 1) intrinsically arborizing
interneurons; and 2) projection neurons. This is significant because the neural
organization of the procerebrum may now be compared with that of olfactory
systems in other organisms.
PMID- 10683612
TI - CK-MB mass test in ischemic myocardial injury. Comparison of two tests:
BioMerieux Vidas and sanofi access immunoassays.
AB - The analytical and clinical performances of the new fluorescent immunoassay (CK
MB mass Vidas-BioMerieux) were examined and compared to the chemiluminescent test
(CK-MB mass Access-Sanofi-Pasteur). Assay precisions of the CK-MB Vidas test
within-assay or between-assay were less than 5.4 and 5.3%, respectively.
Linearity was tested up to 214 microg/L. The CK-MB Vidas test was free of
interference with CK-BB, CK-MM, and macro-CK. One hundred nineteen blood samples
from patients with ischemic myocardial injury (IMI): acute myocardial infarction
(AMI), suspected myocardial contusion (SMC), and unstable angina pectoris (UA),
were tested using both immunoassays. In AMI, a good correlation was found (Y [CK
MB Access] = 1.1372 x [CK-MB Vidas] - 6.3902; r(2) = 0.96). In UA and SMC, low
values were observed and both methods were well correlated (Y [CK-MB Access] =
1.3662 x [CK-MB Vidas] + 0.0671; r(2) = 0.97). Clinical data were in good
agreement with both immunoassays. ROC analysis performed in AMI demonstrated that
the clinical performances of the two assays were similar.
PMID- 10683613
TI - Measurement of adenylate cyclase activity in the right ventricular endomyocardial
biopsy samples from patients with chronic congestive heart failure.
AB - A highly sensitive fluorometric assay technique was adopted in order to examine
the adenylate cyclase activity in the minute right ventricular endomyocardial
biopsy samples from patients with chronic congestive heart failure (n = 10).
Norepinephrine (10(-4) M) and adenosine (10(-3) M) were incubated for 30 min with
10 microl of membrane preparation (1-2 mg protein/mg) to analyze the extent of
the receptor-coupled adenylate cyclase activity. Forskolin (10(-4) M) stimulation
was used to estimate the maximum adenylate cyclase activity (pmol/mg protein/min,
mean +/- SE). The new microanalytical cyclic AMP assay involves four steps:
enzymatic destruction of noncyclic adenine nucleotides and phosphorylated
metabolites, conversion of cyclic AMP to ATP, amplification of ATP by enzymatic
cycling, and fluorometric measurement of NADPH, which is generated in proportion
to initial cyclic AMP levels. Basal and forskolin-stimulated maximum adenylate
cyclase activities were 75 +/- 8 and 123 +/- 15, respectively. Norepinephrine
increased the adenylate cyclase activity to 107 +/- 14, while adenosine tended to
decrease it to 65 +/- 7. In addition, elimination of adenosine by adenosine
deaminase (10 U/ml) slightly increased the adenylate cyclase activity to 82 +/-
9. These results indicate that the adenylate cyclase activity can be measured in
minute endomyocardial biopsy samples. Use of this new approach shows promise of
becoming a new and potentially important way to predict the efficacy of
pharmacological treatment.
PMID- 10683614
TI - An application of apo(a) isoforms for the clinical assessment of Lp(a).
AB - To examine whether or not Lp(a) is applicable as a diagnostic marker for
atherosclerosis, we studied the correlation between Lp(a) levels and molecular
weights of apo(a) isoforms in sera from both normal healthy adults and diabetic
patients. Serum Lp(a) level was measured by turbidimetric immunoassay (TIA) and
the molecular weight of apo(a) isoform was determined by Western blotting
analysis. The serum Lp(a) levels of the diabetic patients (25.0 mg/dl +/- 2.2
[mean +/- SE], n = 54) were significantly higher than those of the normal
subjects (14.4 mg/dl +/- 0.57, n = 500). With respect to the correlation between
serum Lp(a) levels and the molecular weights of apo(a) isoforms, there was an
inverse correlation in sera from normal subjects (n = 298), whereas there was no
correlation in sera from the diabetic patients. Statistical significant inverse
correlation (r = -0.91, y = 224.25 - 3.07x) was especially observed in 50
representative apo(a) isotypes from the normal subjects. By applying a
standardized curve based on the significant inverse correlation to serum Lp(a)
levels, 40.7% (22/54) of the diabetic patients were revealed to have an
abnormally high value of serum Lp(a). Moreover, it was found that the
significantly higher mean value of serum Lp(a) in the diabetic group was caused
by the 22 patients with higher value of Lp(a). The present findings suggest that
determination of apo(a) isoform size provides estimation of the serum Lp(a) value
and that the inverse correlation curve between serum Lp(a) level and the
molecular weight of apo(a) isoform may be applicable to the clinical use of
Lp(a).
PMID- 10683615
TI - Diagnosis of quinolone-resistant Coxiella burnetii strains by PCR-RFLP.
AB - A total of 12 strains of Coxiella burnetii (8 Greek isolates from acute Q-fever
patients, two reference strains-Nine Mile and Q212-and two pefloxacin-resistant
laboratory strains) were examined for the presence of point mutations in the
quinolone resistance determining region (QRDR) of gyrA gene by direct DNA
sequencing of the polymerase chain reaction (PCR)-amplified fragments. The gene
sequences of all eight Greek isolates and the two reference strains Nine Mile and
Q212 [minimal inhibitory concentration (MIC)= 4 microg/ml] were identical.
Direct DNA sequencing of the in vitro-selected resistant strains (MICs to
pefloxacin, 8-32 microg/ml) revealed a transition (G-->A) at the corresponding
codon 87 of E. coli. This mutation lead to the substitution of Glu (codon GAG) by
Lys (codon AAG ). Restriction maps of amplified gyrA gene sequences were
determined by GCG Wisconsin PACKAGE, and the MnlI restriction enzyme was found to
cut only the sensitive strains sequences and not the resistant ones. The present
PCR-RFLP analysis has proved to be a simple, rapid, and useful method for the
detection of Coxiella burnetii and, at the same time, for the diagnosis of
quinolone-resistant Coxiella burnetii strains.
PMID- 10683616
TI - Occurrence of serum M-protein species in Japanese patients older than 50 years
based on relative mobility in cellulose acetate membrane electrophoresis.
AB - We investigated the occurrence of serum M-protein species in 2,007 Japanese
patients older than 50 years of age. All sera samples were analyzed by cellulose
acetate membrane electrophoresis. The relative mobility of an M-protein band was
calculated by dividing the migration distance of M protein by that of albumin. M
proteins were found to be present in 71 of 2,007 cases (3.5%). Men 80-89 years
old showed the highest occurrence of M proteins, 11.0%. The relative mobility of
M-protein bands, especially the band of the IgA-type M protein, increased as the
patient's age advanced. The patients had higher levels of the IgG-type M protein
than healthy Japanese subjects. We found that the occurrence of M-protein species
in Japanese patients increases with their age. The IgG-type M protein was most
frequently expressed among other types. The mobility of the M protein was greater
in older patients probably because of aging-related changes in the carbohydrate
chain of immunoglobulins composing an M-protein molecule.
PMID- 10683617
TI - GB virus C in patients with liver disease of unknown etiology.
AB - To assess the prevalence of GBV-C in patients suffering unknown liver disease we
have investigated the GBV-C-RNA in serum of 54 patients: 10 with acute and 32
with chronic non-A-E hepatitis (16 active and 16 persistent), 10 with
hepatocellular carcinoma, 2 diagnosed with hepatic fulminant failure, and 91
healthy blood donors (control). PCR with primers from NS3 helicase region was
performed and the product was identified by a double strand DNA enzyme
immunoassay. GBV appears to infect 40 and 31% of acute or chronic non-A-E
hepatitis respectively. Also the GBV genome was found in 1 in 10 samples of
hepatocarcinoma, in 2 cases of fulminant hepatitis, and in 1 in 91 of the control
group. In spite of these results the role of GBV in the etiology of liver
diseases has to be analyzed in more comprehensive studies.
PMID- 10683618
TI - Immunoassays for pentamidine and related compounds: development of a facile
inhibitory ELISA suitable for clinical use.
AB - Aromatic dicationic drugs have a broad spectrum of activity against protozoal and
fungal pathogens including Pneumocystis carinii, Leishmania mexicana amazonensis,
Cryptosporidium parvum and Cryptococcus neoformans. Pentamidine serves as the
exemplar for an extensive collection of newly synthesized related compounds,
which have reduced toxicity and a wider range of target organisms. Assays of
pentamidine and related compounds have depended on HPLC-tandem mass spectrometry
(HPLC-TMS) for the quantitation and identification of drug and metabolites.
Immunoassays for pentamidine would have many advantages over the HPLC methods
including relative simplicity of assay format and required equipment, convenience
in sample preparation and reduction in time and cost of assays. In this report we
describe a simple ELISA based immunoassay for pentamidine and pentamidine-like
drugs with requisite sensitivity and specificity for use as a clinical assay
(EC50 value of about 50 nanomolar). Immunogen was synthesized by coupling the
hapten aminopentamidine to ovalbumin (chemically modified to provide an optimal
number of -SH groups) using sulfo-MBS. Maleic-anhydride activated ELISA plates
were covalently sensitized using the aminopentamidine hapten and used in an
inhibitory ELISA assay format whereby the ability of analyte to suppress antibody
binding to sensitized plate was measured. The assay detects primarily the
phenolic amidine of pentamidine when in a para position and hence can also detect
structurally related derivatives of pentamidine of potential interest as new
therapeutic agents.
PMID- 10683619
TI - Clinical utility of a competitive ELISA to detect antibodies against Treponema
pallidum.
AB - Screening for Treponema pallidum infection is carried out on a large human
population. To reduce costs, fewer tests which still offer adequate sensitivity
and specificity could be performed. We studied the reliability of a novel
indirect ELISA method to test for this infection. Several panels of sera were
used that corresponded to 40 primary infections (group 1), 13 recurrences (group
2), 348 latent infections (group 3), 5 samples with anticardiolipin antibodies
(group 4), 15 samples from patients with Lyme borreliosis (group 5), and 400
samples from blood donors and healthy pregnant women (group 6). The ELISA showed
a global sensitivity and specificity of 100 and 99.5%, respectively. Our
evaluation shows that Enzygnost Syphilis is a sensitive, specific, and simple
test to screen for this infection.
PMID- 10683620
TI - Psychotic disorders among inpatients with abuse of cannabis, amphetamine and
opiates. Do dopaminergic stimulants facilitate psychiatric illness?
AB - We have studied the occurrence of dual diagnoses (psychoses as well as abuse of
either amphetamine, cannabis or opiates) during a 15-year period, among patients
treated at Huddinge Hospital, Stockholm, Sweden. The purpose of the study is to
evaluate if the different drugs were coupled to different rates of psychiatric co
morbidity. During the period in question, 461, 425 and 371 different patients
respectively had been admitted at least once due to dependency on amphetamine,
cannabis and opiates. Approximately 30% of the patients with a pure abuse of
amphetamine or cannabis and less than 6% of the opiate abusers had been diagnosed
at least once with any of the psychoses studied. Comparing the frequency of
psychoses among mixed and pure abusers of illegal drugs, with and without a
concomitant abuse of alcohol, we found that the co-morbidity rate for mixed
opiate abusers increased significantly from 7.2 to 20.2% when alcohol abuse was
also present. For abusers of amphetamine and cannabis (both pure and mixed), no
differences in co-morbidity rates were seen when an abuse of alcohol was added to
that of the drugs. It is difficult to find an explanation for the significant
difference between the co-morbidity of pure abuse of amphetamine or cannabis on
the one hand and opiates on the other. In conclusion, our findings show that the
distribution of psychotic illness is high among abusers of amphetamine and
cannabis, in contrast to the generally lower co-morbidity among abusers of
opiates. Although these findings are consistent with earlier studies that have
shown a propensity for developing psychoses among abusers of amphetamine and
cannabis, one should bear in mind that this study is based on inpatients, and is
not necessarily representative for all abusers of the drugs in question.
PMID- 10683621
TI - Alexithymia and anxiety: compounded relationships? A psychometric study.
AB - This study is a careful examination of the relationships between different
components of the alexithymia construct and state versus trait anxiety. In order
to study the relations between anxiety and alexithymia in a subclinical
population, we administered to 125 female college students a test battery
including measures of alexithymia (TAS26), state and trait anxiety (STAI) and
depression (QD2A). Results indicated positive correlations between depression,
anxiety (state and trait) and alexithymia scores. Partial correlations revealed a
tight link between trait anxiety and alexithymia. Furthermore, in agreement with
the view that alexithymia is a multidimensional construct, the various
alexithymia dimensions were found to be diversely correlated with anxiety. On the
basis of partial correlation analyses, a descriptive model of the relationships
between depression, state anxiety, trait anxiety and alexithymia was postulated.
This model was confirmed by pathways analyses.
PMID- 10683622
TI - Need for support and participation in treatment differences among subgroups of
relatives to compulsorily and voluntarily admitted mentally ill individuals.
AB - The need for support and participation in treatment of relatives to voluntarily
and compulsorily admitted patients was addressed in a study of the quality of
mental health services in two Swedish county councils. The aims of the study were
to investigate differences in the above aspects between subgroups of relatives,
the differences between two years of investigation, 1986 and 1991, and the
differences between relatives of voluntarily and compulsorily admitted patients.
The relatives investigated consisted of 79 spouses, 118 parents and 31 grown-up
children. The results showed that there were only minor differences between the
subgroups concerning their participation in care. Grown-up children experienced
significantly less need of support and received less help for this need. In 1991,
relatives participated more in the care situation, were more interested in
support with regard to their own life situation, and also showed more positive
attitudes towards the psychiatric services than in 1986. The relatives of the
voluntarily admitted patients felt more involved in the patient's treatment,
whereas the relatives of those compulsorily admitted felt less involved and
perceived obstacles to admission.
PMID- 10683623
TI - Psychometric qualities of the French version of the Heinrichs quality of life
rating scale.
AB - The quality of life concept has been increasingly used as a major tool for
patient care and clinical investigations. The Heinrichs quality of life scale
(QLS) is the quality of life assessment method widely used in schizophrenic
patients. The QLS was translated into its French version by J.D. Guelfi according
the back-translation method. This version of the validation study included 60
schizophrenic inpatients. The scale possesses acceptable psychometric qualities.
The test-retest reliability is good for nearly all items of the scale and for the
categories and overall score. The internal consistency alpha-coefficients were
0.9 for the global score and varied between 0.6 and 0.9 according to the
category. Factor analysis elicited four factors. Convergent validity is good.
Recommendations for future use of the QLS are proposed.
PMID- 10683624
TI - The development and validation of a Spanish version of the quality of life in
depression scale (QLDS).
AB - OBJECTIVE: The adaptation of the Quality of Life in Depression Scale, the QLDS,
into Spanish. METHODS: The original UK version of the QLDS was considered by two
translation panels, who produced a Spanish translation. Priority was given to
conceptual rather than semantic equivalence. This version was then field-tested
with 15 depressed patients. The final stage of the research involved a postal
survey of 62 patients, who were asked to complete the measure on two occasions.
RESULTS: The Spanish QLDS was found to be appropriate and acceptable by depressed
patients. The questionnaire's test-retest reliability and internal consistency
were both high, and QLDS scores correlated as predicted with scores on sections
of the Nottingham Health Profile. The measure was sensitive to different levels
of depression as assessed by the Hospital Anxiety and Depression Scale.
CONCLUSION: The Spanish version of the QLDS is suitable for use in clinical
trials and for monitoring individual patients in routine clinical practice.
PMID- 10683625
TI - Associations between cortical slow potentials and clinical rating scales in panic
disorder: a 1.5-year follow-up study.
AB - In a previous study of 15 panic patients, we demonstrated that body-related
(somatic) word stimuli elicited an enhanced positive cortical slow wave compared
to non-somatic word stimuli. Healthy controls did not show this difference. The
present paper reports on psychometric ratings in relation to cortical slow waves
in these patients. Patients were clinically reexamined after about 1.5 years.
Although no significant correlations between neurophysiology and psychometric
measures could be found at the onset of the study, there was a significant
correlation between improvement over the follow-up period and neurophysiology. A
decline in the Hamilton Anxiety Scale (HAMA), which proved to be the best
estimate for improvement, was associated with the relative magnitude of the
positive slow wave elicited by somatic stimuli. Our findings support cognitive
models of panic disorder, which stress that abnormal processing of bodily
symptoms is relevant for the development and/or maintenance of the disorder.
PMID- 10683626
TI - Dysphoric subjective response to neuroleptics in schizophrenia: relationship to
extrapyramidal side effects and symptomatology.
AB - OBJECTIVE: Subjective reports of dysphoric responses to neuroleptic medication
are common in clinical practice. However, cognitive and affective side effects of
neuroleptic medications are difficult to differentiate from the symptoms of
schizophrenia. We sought to elucidate the relative contribution of extrapyramidal
side effects and symptomatology to dysphoric response. METHOD: Fifty clinically
stable outpatients with schizophrenia attending a rehabilitation centre were
assessed for extrapyramidal side effects and symptomatology before completing the
drug attitude inventory (DAI). RESULTS: Presence of extrapyramidal side effects,
found in 28 patients (Z = -1.99, p = 0.05), and severity of negative symptoms (r
= -0.47, p = 0.001) were independently associated with dysphoric response,
explaining a significant proportion of the variance (R = 0. 53, R(2) = 25.2%, F =
9.27, df = 2, p = 0.0004). CONCLUSIONS: Patients who report a dysphoric response
which they associate with neuroleptic medications have more extrapyramidal side
effects and more severe negative symptoms. While these responses may be part of
the negative symptoms of the illness or due to other factors such as depression,
we raise the possibility that they may be clinically indistinguishable from, and
be a subjective measure of, the so-called 'neuroleptic-induced deficit syndrome'.
PMID- 10683627
TI - Geographical analysis of the risk of psychiatric hospitalization in Hamburg from
1988 - 1994.
AB - The analysis of the geographical distribution of hospital cases is obviously
important for the purpose of planning hospital services, but it is of even
greater significance in the planning of psychiatric services. This concern
motivated our seven-year-long study, which examined hospitalization risks among
various categories of psychiatric disorders in the major German city of Hamburg.
Our database encompassed 77% (n = 64,000) of all psychiatric admissions in a
total of 41 hospitals, most of which are general hospitals. In order to carry out
the geographical analysis we employed a new statistical method based on a mixture
distribution model. According to our findings, the strongest indications of an
increased frequency were among male cases of schizophrenia, drug abuse and
organic psychoses, and female cases of neurotic disorders, personality disorders,
drug abuse and schizophrenia. We found that some areas are exposed to a risk of
hospitalization for these diagnostic categories which is more than 50% above the
reference. Contrary to other authors we did not identify an increased frequency
of admission concentrated in the inner-city area for any of the diagnostic
groups. The risk of hospitalization for schizophrenics was almost entirely
associated with the close proximity of psychiatric units, while the risks for
neuroses and personality disorders, as well as alcohol and drug abuse, appeared
to be concentrated in areas of low social status. However, a statistically
relevant correlation between an increased risk of hospitalization and low social
status could be determined only for drug abuse and alcoholism. In the end, we did
identify two areas in which there was an increased risk of hospitalization for
several diagnostic groups, and this information will undoubtedly facilitate the
planning of hospital and psychiatric services. The fact that our findings deviate
to some extent from other authors - especially with respect to neuroses and
personality disorders, but also to addiction - can be attributed to the inclusion
of psychiatric cases from general hospitals in our geographic analysis.
PMID- 10683628
TI - Comparison of the diagnosis of melancholic and atypical features according to DSM
IV and somatic syndrome according to ICD-10 in patients suffering from major
depression.
AB - While melancholic (according to DSM) or somatic syndrome (according to ICD) has
strong historical roots and substantial empirical verification, the concept of
atypical features is relatively new and not sufficiently studied. The aim of the
current study was to investigate the reliability of these diagnostic
subcategories in patients suffering from major depression in Greece. Forty
patients (eight males and 32 females) aged 19-60 years (mean 39.3, sd 12.2)
suffering from major depression according to DSM-IV criteria were studied. SCAN
v.2.0 was used to assess symptomatology. The presence of each criterion according
to DSM-IV and ICD-10 was registered. Frequency tables were developed and factor
and cluster analysis were performed. The results of the analysis suggest the
existence of three syndromes which roughly reflect the melancholic and atypical
but also propose a third, which can be considered as an 'undifferentiated'
syndrome. The DSM demand that the existence of melancholic features be excluded
first and then that diagnosis of atypical features be made was confirmed.
PMID- 10683629
TI - Gender-related clinical differences in obsessive-compulsive disorder.
AB - The purpose of the present study was to investigate the gender-related
differences of clinical features in a sample of obsessive-compulsive (OCD)
patients. One hundred and sixty outpatients with a principal diagnosis of
obsessive-compulsive disorder (DSM-IV, Y-BOCS = 16) were admitted. Patients were
evaluated with a semi-structured interview covering the following areas: socio
demographic data, Axis I diagnoses (DSM-IV), OCD clinical features (age at onset
of OC symptoms and disorder, type of onset, life events and type of course). For
statistical analysis the sample was subdivided in two groups according to gender.
We found an earlier age at onset of OC symptoms and disorder in males; an
insidious onset and a chronic course of illness were also observed in that group
of patients. Females more frequently showed an acute onset of OCD and an episodic
course of illness; they also reported more frequently a stressful event in the
year preceding OCD onset. A history of anxiety disorders with onset preceding OCD
and hypomanic episodes occurring after OCD onset was significantly more common
among males, while females showed more frequently a history of eating disorders.
We found three gender-related features of OCD: males show an earlier age at onset
with a lower impact of precipitant events in triggering the disorder; OCD seems
to occur in a relative high proportion of males who already have phobias and/or
tic disorders; and a surfeit of chronic course of the illness in males in
comparison with females.
PMID- 10683630
TI - Discriminant cognitive factors in responder and non-responder patients with
schizophrenia.
AB - To identify which improvements in cognitive function are associated with symptom
resolution in schizophrenic patients treated with atypical antipsychotics.
DESIGN: a prospective open trial with atypical neuroleptics (risperidone,
clozapine, quetiapine). SETTING: Inpatient and outpatient units, Institute of
Psychiatry. PATIENTS: Thirty-nine patients with schizophrenia according to DSM-IV
criteria were included. Clinical and cognitive assessment were done at baseline
(T0) and again after six months of treatment (T2). Twenty-five patients completed
the trial. INTERVENTIONS: New-generation antipsychotics during six months.
Patients were considered as responders if their PANSS score decreased at least
20% (n = 15) and non-responders if it did not (n = 10). OUTCOME MEASURES: a
computerized cognitive assessment comprised tests of short-term-memory (digit
span), explicit long-term memory (word pair learning), divided attention,
selective attention and verbal fluency (orthographic and semantic). Clinical
assessment included PANSS and ESRS. RESULTS: A discriminant function analysis was
performed to determine which changes in cognitive performance predicted
symptomatic response status. Semantic fluency and orthographic fluency were
significant predictors. Together they correctly predicted responder status in 88%
of cases. Memory was not a significant predictor of symptomatic response.
CONCLUSION: Verbal fluency discriminated the responder from the non-responder
group during a pharmacological treatment.
PMID- 10683631
TI - Evidence for an increase in functional platelet 5-HT2A receptors in depressed
patients using the new ligand [125I]-DOI.
AB - Abnormalities in the serotonergic system have been implicated in the
pathophysiology of depressive disorders. Human platelets possess serotonin-2A (5
HT(2A)) receptors, and previous research using LSD or ketanserin as ligands have
indicated that their number is increased in depressed patients. Compared to other
ligands previously used in platelet studies, DOI is highly selective for the 5
HT(2A) receptor and binds to its high-affinity state, therefore labeling only the
receptors that are biologically coupled to the G-protein. We determined the
density (Bmax) and the affinity (Kd) of 5-HT(2A) receptors labeled by [(125)I]
DOI in platelets from 21 untreated patients with major depression and 21 healthy
volunteers. The density of the 5-HT(2A) binding sites was found to be increased
in platelets from female depressed patients as compared to controls. No changes
were observed in the Kd. We did not find any relationship between the binding
parameters and either the severity of the depressive episode or the suicidal
tendencies of the patients. Our results show that the number of coupled platelet
5-HT(2A) receptors is increased in depressed patients, indicating that platelet 5
HT(2A) receptor function is enhanced in depression.
PMID- 10683633
TI - Changing patterns of mental health care in Greece (1984-1996).
AB - Greece joined the European Community in 1981 and, three years later, the
Commission of the European Communities provided financial and technical
assistance under EEC Regulation 815/84 for the modernisation of the traditional
psychiatric care system, with the emphasis on decentralisation of mental health
services and the development of community-based services, as well as on
deinstutionalization of long-stay patients and improvement of conditions in
public mental hospitals. Over the last 11 years, the implementation of the EEC
Reg. 815/84 programme contributed to a significant shift towards extramural care
and rehabilitation. The role of the large mental hospitals has gradually been
diminished and a large number of long-stay patients have been
deinstitutionalised. It is commonly accepted that the EEC-funded psychiatric
reform programme, despite inadequacies and constraints, had an impact on the
changing mental health scene in Greece.
PMID- 10683632
TI - Psychotic versus nonpsychotic bipolar outpatient depression.
AB - Psychotic bipolar depression was compared with nonpsychotic bipolar depression.
Psychotic (n = 59) and nonpsychotic (n = 176) bipolar depressed outpatients were
SCID-DSM-IV interviewed. Psychotic bipolar depression had significantly higher
severity, more chronicity, fewer atypical features and axis I co-morbidity, more
bipolar I, and fewer bipolar II patients. Age at onset, duration of illness,
gender, and recurrences, were not significantly different.
PMID- 10683634
TI - Conversion disorder: a case report of treatment with the Main Puteri, a Malay
shamanastic healing ceremony.
AB - We report on the case of a 38-year-old Malay housewife diagnosed with conversion
disorder. It was believed that 'evil spirits' caused her symptoms. The patient
was eventually treated by the Main Puteri, a Malay shamanistic healing ceremony,
after previous treatments failed. The patient improved on the third day of the
performance, which was attributed to the departure of the spirits from her body.
This case documents the potential benefits of indigenous psychotherapy.
PMID- 10683635
TI - Families: in the way?
PMID- 10683636
TI - 'Why couldn't I have seen him?'.
PMID- 10683637
TI - The number of partners.
PMID- 10683638
TI - Setting up a home-based business.
PMID- 10683639
TI - Reversing respiratory depression with naloxone.
PMID- 10683640
TI - MAOIs: still here, still dangerous.
PMID- 10683641
TI - Family presence during invasive procedures and resuscitation.
PMID- 10683642
TI - Till death do us part. A firsthand account of family presence.
PMID- 10683643
TI - Renovascular hypertension.
PMID- 10683644
TI - Dialysis disequilibrium syndrome.
PMID- 10683645
TI - Pharmacologic treatment of dyslipidemia.
PMID- 10683646
TI - Have we forgotten the patient?
PMID- 10683647
TI - How long-term care is changing.
PMID- 10683648
TI - From incontinence to confidence.
PMID- 10683649
TI - Optimism, pessimism, and mortality.
PMID- 10683650
TI - Vaccine safety: injecting a dose of common sense.
PMID- 10683651
TI - Optimists vs pessimists: survival rate among medical patients over a 30-year
period.
AB - OBJECTIVE: To examine explanatory style (how people explain life events) as a
risk factor for early death, using scores from the Optimism-Pessimism scale of
the Minnesota Multiphasic Personality Inventory (MMPI). SUBJECTS AND METHODS: A
total of 839 patients completed the MMPI between 1962 and 1965 as self-referred
general medical patients. Thirty years later, the vital status of each of these
patients was ascertained. RESULTS: Of the 839 patients, 124 were classified as
optimistic, 518 as mixed, and 197 as pessimistic. Follow-up was available for 723
patients. Among these, a 10-point T-score increase on the Optimism-Pessimism
scale (e.g., more pessimistic) was associated with a 19% increase in the risk of
mortality. CONCLUSION: A pessimistic explanatory style, as measured by the
Optimism-Pessimism scale of the MMPI, is significantly associated with mortality.
PMID- 10683652
TI - Poststreptococcal reactive arthritis in adults: a case series.
AB - OBJECTIVE: To guide primary care physicians regarding the diagnosis and treatment
of poststreptococcal reactive arthritis (PSReA) in adults. PATIENTS AND METHODS:
We retrospectively reviewed an indexed database of all patients evaluated or
hospitalized between 1976 and 1998 at Mayo Clinic Rochester and identified 35
patients with the diagnosis of reactive streptococcal arthritis, arthralgia, or
arthritides. Twenty-nine patients with the diagnosis of acute rheumatic fever
(ARF), septic streptococcal arthritis, or nonspecific reactive arthritis were
excluded. RESULTS: PSReA was confirmed in 6 adults (3 women, 3 men; age range, 25
66 years). All patients were symptomatic with polyarthritis and oligoarthritis
disproportionate to the objective findings on physical examination. Although all
patients had negative throat cultures at the onset of arthritis, increased titers
of anti-DNase B and antistreptolysin O confirmed recent streptococcal infection.
Antecedent events included pharyngitis in 3 patients (who had received a minimum
of a 10-day course of penicillin) and toxic shock syndrome in 1 patient. The
latency of onset of arthritis ranged from 4 days to 6 weeks. The arthritic
symptoms had a protracted course beyond the typical maximum of 3 weeks described
for ARF. Treatment with aspirin did not provide symptomatic relief in any of the
patients, whereas the response to therapy with nonsteroidal anti-inflammatory
drugs (NSAIDs) was at least partial in all cases. Symptomatic relief occurred in
1 patient who received indomethacin and in 1 patient treated with prednisone.
Penicillin prophylaxis was recommended in 1 patient. CONCLUSION: PSReA should be
included in the differential diagnosis of all adult patients presenting with
arthritis. Treatment strategies include aspirin, other NSAIDs, and
corticosteroids. In adult patients with PSReA, there is no evidence to support
the use of penicillin prophylaxis at this time.
PMID- 10683653
TI - Left ventricular diastolic dysfunction in patients with hypertension and
preserved systolic function.
AB - OBJECTIVE: To assess prospectively diastolic function in hypertensive patients
with preserved left ventricular function, particularly focusing on the limitation
of the transmitral flow velocity curve alone to detect diastolic dysfunction.
PATIENTS AND METHODS: Comprehensive Doppler analysis was performed in 51
hypertensive patients with preserved left ventricular systolic function. RESULTS:
The ratio of the peak early diastolic filling wave velocity to the peak velocity
of filling wave at atrial contraction was less than the age-adjusted mean value
minus 2 SD in 16 patients, and the other 35 patients had a "normal" transmitral
Doppler signal. However, the combined transmitral and pulmonary venous Doppler
analysis revealed that 12 of these 35 patients had a "pseudonormal" pattern. The
prevalence of diastolic dysfunction was estimated at 31% with use of transmitral
Doppler alone but increased to 55% when comprehensive Doppler analysis was used
(P < .05). CONCLUSION: The presence of diastolic dysfunction has been frequently
overlooked in hypertensive patients with transmitral Doppler analysis alone, and
an assessment of diastolic function with a comprehensive Doppler analysis is
needed in patients at risk for diastolic dysfunction.
PMID- 10683654
TI - Busy physicians and preventive services for adults.
AB - OBJECTIVE: To study the relationship between overall productivity and the rates
at which primary care physicians, in a fee-for-service setting, deliver or
prescribe preventive services to adult patients. PATIENTS AND METHODS: The charts
of 452 adult patients treated by 8 family practitioners and 5 internists in a fee
for-service practice setting were randomly selected and abstracted for provision
of 10 preventive services over a 27-month period. The percentage of eligible
patients screened for each service was correlated with the production of each
physician measured in relative value units (RVUs). RESULTS: The correlation
coefficient between RVUs and the aggregate of the 10 services was 0.23 (95%
confidence interval [CI], -0.36 to 0.70). The individual correlation coefficients
between RVUs and 9 of the 10 preventive services ranged from -0.05 to 0.43. For
cervical cancer screening, however, the correlation coefficient was -0.72 (95%
CI, -0.91 to -0.24). CONCLUSION: With the exception of screening for cervical
cancer, the data presented in this study do little to support physicians' common
belief that lack of time is the reason they are unable to incorporate prevention
strategies into their clinical practice.
PMID- 10683655
TI - Johann Deisenhofer--Nobel Laureate in chemistry.
PMID- 10683656
TI - Clinical preventive medicine in primary care: background and practice: 1.
Rationale and current preventive practices.
AB - Impressive evidence supports the value of clinical preventive medicine, defined
as the maintenance and promotion of health and the reduction of risk factors that
result in injury and disease. Primary prevention activities deter the occurrence
of a disease or adverse event, e.g., smoking cessation. Secondary prevention
(screening) is early detection of a disease or condition in an asymptomatic stage
so treatment delays or blocks occurrence of symptoms, e.g., mammographic
detection of breast cancer. Tertiary prevention attempts to not allow adverse
consequences of existing clinical disease, e.g., cardiac rehabilitation to
prevent the recurrence of a myocardial infarction. Preventive services have
decreased morbidity and mortality from both acute and chronic conditions.
However, these services are underutilized for numerous reasons. Barriers to their
use include physician, patient, and health system factors. The traditional
disease/treatment model should be modified to incorporate more preventive
services. The subsequent 2 parts of this review will discuss suggestions for
integrating primary preventive services and screening into primary care practice.
PMID- 10683658
TI - Palliative care and hospice programs.
AB - Palliative care and hospice programs are points on the continuum of comprehensive
patient care. Unfortunately, provision of care for terminally ill patients is
suboptimal. There are many new approaches to improving the skills of all
physicians to fulfill the needs of patients, including better education for house
staff, "train-the-trainers" programs for physicians in practice, research into
methods of symptom control, and better access to established hospice programs.
This review covers the history, current status, and practical suggestions for
improving palliative care and hospice programs in primary care settings.
PMID- 10683657
TI - Dual chamber pacing for patients with hypertrophic obstructive cardiomyopathy: a
clinical perspective in 2000.
AB - In some patients with hypertrophic cardiomyopathy, the dynamic left ventricular
outflow tract obstructive gradient results in exercise-limiting symptoms of
dyspnea, angina, and syncope. Dual chamber pacing has been proposed as a widely
available alternative treatment for a subset of patients with symptomatic
hypertrophic obstructive cardiomyopathy. Initial studies showed a reduction in
gradient and an improvement in symptoms in almost 90% of patients with severe
symptoms. We report the Mayo Clinic experience with dual chamber pacing in 38
patients with hypertrophic obstructive cardiomyopathy who had permanent
pacemakers implanted for limiting symptoms intractable to medical therapy. After
a mean +/- SD follow-up of 24 +/- 14 months, subjective improvement was reported
in 47% of patients. However, there was no statistical difference between the
maximal oxygen consumption at last follow-up and AAI pacing (atrial sensing and
atrial pacing) (18.6 +/- 1.1 mL.kg-1.min-1) (i.e., when the pacemaker was
implanted but not pacing continuously). This article discusses the clinical
perspective on the utility of dual chamber pacing for patients with hypertrophic
obstructive cardiomyopathy.
PMID- 10683659
TI - Chronic obstructive pneumonia caused by a vertebral body osteophyte.
AB - Osteophytes associated with spondylosis have been implicated as a cause of
multiple extraspinal manifestations. Symptoms are more likely to occur with the
large osteophytes associated with diffuse idiopathic skeletal hyperostosis. In
the thoracic region, osteophytes have been reported infrequently as a cause of
extraspinal complications. We report a case in which an anterior thoracic
vertebral osteophyte was responsible for chronic obstructive pneumonia due to
obstruction of the right main stem bronchus. The patient's condition improved
considerably after surgical resection of the compressing thoracic osteophyte.
PMID- 10683660
TI - Anemia: a cause of intolerance to thyroxine sodium.
AB - Usual causes of intolerance to thyroxine sodium include coronary artery disease,
advanced age, untreated adrenal insufficiency, and severe hypothyroidism. We
describe 4 patients with iron deficiency anemia and primary hypothyroidism. After
treatment with thyroxine sodium, these patients developed palpitations and
feelings of restlessness, which necessitated discontinuation of the thyroid
hormone. After the anemia was treated with ferrous sulfate for 4 to 7 weeks, they
were able to tolerate thyroxine sodium therapy. Iron deficiency anemia coexisting
with primary hypothyroidism results in a hyperadrenergic state. In such patients,
we postulate that thyroid hormone administration causes palpitations,
nervousness, and feelings of restlessness. Correction of any existing pronounced
anemia in hypothyroid patients who are intolerant to thyroxine sodium therapy may
result in tolerance to this agent.
PMID- 10683661
TI - 59-year-old man with epistaxis, headache, and cough.
PMID- 10683662
TI - The losses and suffering of terminal illness.
PMID- 10683663
TI - Clinical aspects of antimicrobial resistance.
AB - Soon after penicillin was introduced into clinical use, an enzyme (penicillinase)
that inactivated it was discovered. Since then, the variety of antimicrobial
agents has increased substantially, along with a parallel increase in resistant
pathogenic microorganisms. Resistance is now recognized against all available
antimicrobial agents. Factors influencing the emergence of resistance include
indiscriminate use of antibiotics, prolonged hospitalizations, increasing numbers
of immunocompromised patients, and medical progress resulting in increased use of
invasive procedures and devices. This article provides an update on clinical
aspects of a few commonly found resistant microorganisms relevant to day-to-day
clinical practice. A discussion of all resistant organisms is beyond the scope of
this report. Both viral and mycobacterial resistance have been addressed in
previous articles in this symposium.
PMID- 10683664
TI - Improvement of anemia induced by parvovirus B19 in a patient with AIDS after
combined antiretroviral therapy.
PMID- 10683665
TI - Dynamic left ventricular outflow tract obstruction in acute coronary syndromes.
PMID- 10683666
TI - Drugs for HIV infection.
PMID- 10683667
TI - VII Congress of the Bulgarian Society of Physiological Sciences. Sofia, June 10
11, 1999. Abstracts.
PMID- 10683668
TI - 10th World Congress of the International Organization of Psychophysiology (IOP).
Sydney, Australia, 8-13 February 2000. Abstracts.
PMID- 10683669
TI - In what way does the parietal ERP old/new effect index recollection?
AB - Event-related potentials (ERPs) were recorded while subjects performed a memory
retrieval task requiring old/new judgements to visually presented old (previously
studied) and new words. For words judged old, subjects made two binary forced
choice context (hereafter source) judgements, denoting the voice (male/female)
and task (action/liking) with which the test word had been associated at study.
By separating the ERPs according to the accuracy of the voice and task
judgements, it was possible to test the prediction that the differences between
ERPs to correctly identified old and new words at parietal scalp sites (parietal
old/new effects) are sensitive to the amount or quality of information that is
retrieved from episodic memory (Rugg, M.D., Cox, C.J.C., Doyle, M.C., Wells, T.,
1995. Event-related potentials and the recollection of low and high frequency
words. Neuropsychologia 33, 471-484). In keeping with this proposal, the
magnitude of the parietal old/new effects co-varied with the number of accurate
source judgements. This finding is consistent with proposals that the parietal
old/new effect indexes recollection in a graded fashion.
PMID- 10683670
TI - Annual meeting of the Society for Adolescent Medicine. Arlington, Virginia, USA.
March 22-26, 2000. Abstracts.
PMID- 10683671
TI - British Association of Sports and Exercise Sciences Annual Conference. 7-10
September 1999. Abstracts.
PMID- 10683672
TI - A comparative evaluation of open loop and closed loop drug administration
strategies in the treatment of AIDS.
AB - In recent years, many researchers in the field of biomedical sciences have made
successful use of mathematical models to study, in a quantitative way, a
multitude of phenomena such as those found in disease dynamics, control of
physiological systems, optimization of drug therapy, economics of the preventive
medicine and many other applications. The availability of good dynamic models
have been providing means for simulation and design of novel control strategies
in the context of biological events. This work concerns a particular model
related to HIV infection dynamics which is used to allow a comparative evaluation
of schemes for treatment of AIDS patients. The mathematical model adopted in this
work was proposed by Nowak & Bangham, 1996 and describes the dynamics of viral
concentration in terms of interaction with CD4 cells and the cytotoxic T
lymphocytes, which are responsible for the defense of the organism. Two
conceptually distinct techniques for drug therapy are analyzed: Open Loop
Treatment, where a priori fixed dosage is prescribed and Closed Loop Treatment,
where the doses are adjusted according to results obtained by laboratory
analysis. Simulation results show that the Closed Loop Scheme can achieve
improved quality of the treatment in terms of reduction in the viral load and
quantity of administered drugs, but with the inconvenience related to the
necessity of frequent and periodic laboratory analysis.
PMID- 10683673
TI - Seasonal variations in water quality of an oxbow lake in response to multiple
short-time pulses of flooding (Jatai Ecological Station--Mogi-Guacu River, Luiz
Antonio, SP-Brazil).
AB - Mogi-Guacu River is a six-order floodplain river in the upper Parana River Basin,
Southern Brazil. Its yearly discharge varies from a minimum of 100 m3.s-1 to a
maximum of 600 m3.s-1. Diogo Lake is a shallow lake located at its floodplain
within the Jatai Ecological Station (Luiz Antonio, Sao Paulo State) and is
connected throughout the year to the river through a narrow and shallow channel.
The main finding of this study is that the river hidrology controls the annual
variations in lake hydrochemistry through a series of hydraulic effects related
to oscillations in river discharge. Lake water quality is a resultant of
differential contribution from local and regional watersheds. During the low
water period, lake water quality is determined by inputs from Cafundo Creek,
which drains the local watershed into the lake. Raising the river level during
the rain season results in the damming of lake and culminates with the entrance
of river waters into the plain. The geochemistry of waters in this system is
determined by weathering of sandstones with basalt intrusions. Waters are acidic
(river pH = 6.00 to 7.02 and stream-lake pH = 5.15 to 6.7) and dominant cations
are Na+ and K+. Major anions are almost exclusively represented by bicarbonate
and an unknown concentration of organic acid anions. The overall ionic load of
these soft waters in the system is therefore very low.
PMID- 10683674
TI - The advancement of science in Brazil.
PMID- 10683675
TI - Filling-in in topographically organized distributed networks.
AB - We propose a framework for understanding visual perception based on a
topographically organized, functionally distributed network. In this proposal the
extraction of shape boundaries starts at retinal ganglion cells with concentric
receptive fields. This information, relayed through the lateral geniculate
nucleus, creates a neural representation of negative and positive boundaries in a
set of topographically connected and organized visual areas. After boundary
extraction, several processes involving contrast, brightness, texture and motion
extraction take place in subsequent visual areas in different cortical modules.
Following these steps of processing, filling-in processes at different levels,
within each area, and in separate channels, propagate locally to transform
boundary representations onto surfaces representations. These partial
representations of the image propagate back and forth in the network, yielding a
neural representation of the original image. We propose that completion takes
places in a wide cortical circuit that heavily relies on V1, where long-range
information helps determine contour responses at specific topographically
organized locations. Neural representations of illusory contours would emerge in
circuits involving primarily area V2. The neural representation of filling-in of
a peripheral stimulus in a dynamic surround (such as in texture filling-in) would
depend on circuits involving primarily cells in areas V2 and V3, and would
include competitive mechanisms required for figure to ground segregation.
Finally, we suggest that multiple representations of the stimulus engage
competitive mechanisms that select the "most likely hypothesis". Such choice
behavior would rely on winner-take-all mechanisms capable of constructing a
single neural representation of perceived objects.
PMID- 10683676
TI - Recent trends in environmental and ecological modelling.
AB - The paper outlines the history of modelling and presents a status of ecological
modelling: what is the modelling effort of various ecosystem and various
environmental problems. Typical validation results and prognosis validation
results of a eutrophication model are applied as an illustration of what models
can do in environmental management. Structural dynamic modelling which considers
parameters that are changed currently by optimisation of a so-called goal
function is presented as one of the recent development to overcome one of the
most crucial problems in modelling, namely to consider adaptation. Two case
studies are presented to illustrate this approach, namely application of
biomanipulation and eutrophication of a shallow lake. Forecast on the directions
of development is finally presented.
PMID- 10683677
TI - Identification of a new Lesch-Nyhan syndrome mutation (HPRTBrasil) and analysis
of potentially heterozygous females.
AB - The mutation in the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene
has been determined in two brothers affected with Lesch-Nyhan syndrome. Female
members of the family who are at risk for being heterozygous carriers of the HPRT
mutation were also studied to determine whether they carry the mutation. DNA
sequencing revealed that the boys' mother is heterozygous for the mutation in her
somatic cells, but that three maternal aunts are not heterozygous. Such carrier
information is important for the future pregnancy plans of at-risk females. The
mutation, an A-->T transversion at cDNA base 590 (590A-->T), results in an amino
acid change of glutamic acid to valine at codon 197, and has not been reported
previously in a Lesch-Nyhan syndrome male. This mutation is designated
HPRTBrasil.
PMID- 10683678
TI - Magnetic resonance findings in amyotrophic lateral sclerosis using a spin echo
magnetization transfer sequence. Preliminary report.
AB - We present the magnetic resonance (MR) findings of five patients with amyotrophic
lateral sclerosis (ALS) using a spin-echo sequence with an additional
magnetization transfer (MT) pulse on T1-weighted images (T1 SE/MT). These
findings were absent in the control group and consisted of hyperintensity of the
corticospinal tract. Moreover we discuss the principles and the use of this fast
but simple MR technique in the diagnosis of ALS.
PMID- 10683679
TI - Possible analgesic effect of vigabatrin in animal experimental chronic
neuropathic pain.
AB - Since anticonvulsants have been used for treating neuralgias, an interest has
arisen to experimentally test vigabatrin for its gabaergic mechanism of action.
For this, 41 Wistar rats were used, and in 25 of them a constrictive sciatic
neuropathy was induced (Bennet & Xie model). For testing pain symptoms,
spontaneous (scratching) and evoked behaviors to noxious (46 degrees C) and non
noxious (40 degrees C) thermal stimuli were quantified. Moreover, a comparative
pharmacological study of vigabatrin with other analgesic anticonvulsant drugs was
also performed. The results showed a possible dose-dependent analgesic effect of
vigabatrin (gamma-vinyl-GABA) on experimental neuropathic pain, as shown by the
significant (p < 0.05) decreasing effect of vigabatrin on scratching and by its
significant (p < 0.05) increasing effect on the latency of the right hindpaw
withdrawal of the animals to noxious thermal stimulus. This was corroborated by
similar findings with analgesic anticonvulsants (carbamazepine, phenytoin and
valproic acid). This possible and not yet described analgesic effect of
vigabatrin seems not to be opioid mediated.
PMID- 10683680
TI - Magnetic resonance imaging in five patients with a tumefactive demyelinating
lesion in the central nervous system.
AB - Five patients with a tumefactive lesion were clinically followed from 1992 to
1993. Four patients were female; age ranged from 32 to 57 years, the duration of
symptoms varied from 3 days to 3 years. Neurological examination disclosed
dementia in two patients, aphasia in three, hemiparesis in four,
hemihypoaesthesia in three, optical neuritis in two, tetraparesis with sensitive
level and neurogenic bladder in one. MRI disclosed lesions with a hypersignal on
images assessed at T2 and hyposignal at T1, and gadolinium heterogeneous
enhancement; these lesions were located in the: a) temporooccipital region
bilaterally and brain stem, b) frontoparietal white matter, c) basal ganglia,
bilateral white matter and brain stem, d) left parietal region, e) cervical
spinal cord, with enlargement of this region. Cerebral biopsy was performed in
three patients; acute and subacute demyelinating disease was diagnosed by
histological examination. Two patients had an evolutive diagnosis; exclusion of
other pathologies and clinical and radiological improvement after corticotherapy,
pointed to an inflammatory disease.
PMID- 10683681
TI - Multiple sclerosis in Brazil. Analysis of cerebrospinal fluid by standard
methods.
AB - The demonstration of intrathecal IgG synthesis has been used as an important
laboratory parameter to support the diagnosis of multiple sclerosis (MS). The
Committee for European Concerted Action for Multiple Sclerosis has recommended a
protocol for the assessment of intrathecal IgG synthesis. We applied this
methodology to determine the cerebrospinal (CSF) profile of 128 Brazilian
patients with MS. We detected hypercytosis lower than 35 cells/mm3 in 97%,
protein lower than 80 mg/dl in 99%, normal blood-CSF barrier function in 76%,
increased IgG local production around 53% and oligoclonal IgG bands by
isoelectric focusing in 85% of the definite MS patients. The diagnostic accuracy
of the quantitative analysis was lower than the qualitative. The detection of
oligoclonal bands was especially important in the cases of normal quantitative
assays of IgG. In addition, we found a lower frequency of inflammatory reaction
in CSF in our MS cases, in comparison to some European studies.
PMID- 10683682
TI - Panic disorder and hyperventilation.
AB - Respiratory abnormalities are associated with anxiety, particularly with panic
attacks. Symptoms such as shortness of breath, "empty-head" feeling, dizziness,
paresthesias and tachypnea have been described in the psychiatric and respiratory
physiology related to panic disorder. Panic disorder patients exhibit both
behaviorally and physiologically abnormal responses to respiratory challenges
tests. OBJECTIVE: We aim to observe the induction of panic attacks by
hyperventilation in a group of panic disorder patients (DSM-IV). METHOD: 13 panic
disorder patients and 11 normal volunteers were randomly selected. They were drug
free for a week. They were induced to hyperventilate (30 breaths/min) for 3
minutes. Anxiety scales were taken before and after the test. RESULTS: 9 (69.2%)
panic disorder patients and one (9.1%) of control subjects had a panic attack
after hyperventilating (p < 0.05). CONCLUSION: The panic disorder group was more
sensitive to hyperventilation than normal volunteers. The induction of panic
attacks by voluntary hyperventilation may be a useful and simple test for
validating the diagnosis in some specific panic disorder patients.
PMID- 10683683
TI - [Psychiatric symptoms among patients with dementia seen in an ambulatory
service].
AB - Subjects with dementia often display an array of neuropsychiatric symptoms that
include disorders of mood, delusions, hallucinations, vegetative symptoms and
psychomotor abnormalities. The present study was designed to investigate the
prevalence of psychiatric morbidity amongst patients with the clinical diagnosis
of dementia (ICD-10) assessed at a Memory Clinic in Sao Paulo-Brazil between
February 1997 and May 1998. The mental and cognitive state of patients were
assessed with an extended version of the SRQ-20 and the MMSE respectively. Thirty
four (45.3%) out of a total of 75 subjects scored 8 or more on the SRQ-20,
indicating the presence of significant psychiatric morbidity. Depressive symptoms
were reported by 69.3% of patients. Persecutory ideas and auditory hallucinations
were observed in 20.0% and 16.0% of the sample respectively. Eight subjects
(10.7%) described suicidal ideation--they all displayed depressive symptoms.
Patients with scores on the SRQ-20 > or = 8 or who described suicidal ideation
were significantly younger than their counterparts. Auditory hallucinations were
more frequent amongst subjects with lower MMSE scores. There were no sex
differences in the distribution of the psychiatric symptoms under investigation.
The assessment of patients with dementia should always include a detailed
psychiatric examination, as the detection and treatment of such symptoms may
contribute to decrease the stress of patients and the burden on carers.
PMID- 10683684
TI - [Facial recognition and autism].
AB - Through the presentation of four facial expressions' illustrations, we evaluate
the capacity of autistic children recognition, comparing with normal intelligence
children and adults. The comparison of results was accomplished through the qui
square test. The differences observed were significant, showing that a
disturbance of the facial expressions' perception is present in autistic
children, and that it interferes directly in the social relationships.
PMID- 10683685
TI - [Brain hypoxic-injury of hemorrhagic pattern in newborns: analysis of 1028
autopsies from 1960 to 1995].
AB - Hypoxic-ischaemic injury of the central nervous system (CNS) in newborns is a
very prevalent entity affecting 1 to 6 children per 1000 births. This injury may
induce severe neurological sequelae. We present the analysis of 1028 consecutive
cases of hypoxic-ischaemic CNS injuries of haemorrhagic pattern detected in
autopsies performed at the Division of Anatomic Pathology, Hospital de Clinicas,
University of Parana, Brazil, from 1960 to 1995. The prevalence of these lesions
was high (49.73%) amongst all autopsied newborns. The main types of haemorrhage
were microscopical intra-parenchymal haemorrhages, intraventricular and
periventricular haemorrhages and subarachnoid foci of bleeding. Our results
emphasize that premature children constitute a high risk group for CNS
haemorrhage needing special preventive therapeutic procedures to avoid
neurological complications.
PMID- 10683686
TI - [DNA ploidy in astrocytoma. Study in 66 Brazilian patients].
AB - The determination of the nuclear DNA content (S-phase fraction (SPF) and ploidy)
was carried out by image analysis (IA). The morphometric and densitometric
features of Feulgen-stained nuclei were determined from stored formalin-fixed and
paraffin-embedded specimens of 66 patients with intracranial astrocytomas. Our
results suggest a strong relationship between patient age, histological grade,
survival and DNA ploidy and SPF. The analysis of the proliferative activity of
intracranial astrocytomas is very helpful in understanding biological
stractification and prognostication to assess tumor behaviour and planning of
treatment strategies.
PMID- 10683687
TI - [Congestive brain swelling in victims of fatal road accident. Frequency and
association with other head injury lesions].
AB - A morphological study, macro and microscopical, was made of brain lesions in 120
victims of fatal road traffic accidents. Congestive brain swelling occurred in 21
(17.5%) patients. Owing to the brain swelling that increases the brain volume, an
increase of brain weight was also observed. Brain contusion was the most frequent
lesion associated with congestive brain swelling (76.2%), while the intracranial
haematomas were observed in almost half of the cases.
PMID- 10683688
TI - [Burst lobe in victims of fatal road traffic accident. Frequency and association
with other head injury].
AB - A morphological study, macro and microscopical, was made of brain lesions in 120
victims of fatal road traffic accidents. Burst lobes were identified in 12
(10.0%) of the patients. It occurred in the frontal lobe in 6 (50.0%) patients,
in the temporal lobe in 2 (16.7%) and in both lobes in 4 (33.3%) patients. A
skull fracture occurred in 8 (66.7%) patients and intracranial hypertension
occurred in half of cases. Nine patients were admitted in coma and three patients
died immediately after the road traffic accident. All cases of burst lobes were
associated with diffuse axonal injury, which explains the severe alteration of
consciousness observed at the patients' admission.
PMID- 10683689
TI - [The involvement of the brachial plexus in cardiac surgery with median sternotomy
for the revascularization of the myocardium: clinical evaluation].
AB - To evaluate the involvement of brachial plexus in cardiac surgery with median
sternotomy for the revascularization of the myocardium 113 patients (87 men and
26 women) were clinically examined in the preoperative and between the fifth and
eight post-operative days. The internal thoracic artery was used in 65 of the 113
patients. The electroneuromyography was not effected in any of the patients. A
lesion of the brachial plexus was found in three patients though the internal
thoracic artery was used in only one patient. We believe that factors such as
posture of the patient, hypothermia, thoracic braces and use of the internal
thoracic artery are relevant in the lesions. Hence one must be attentive to all
the factors mentioned above so as to avoid or minimize the lesions.
PMID- 10683690
TI - [Medulloblastoma in adults: analysis of a casuistics and surgical results].
AB - We report on 15 cases of medulloblastoma of adult onset (8 male and 7 female)
operated upon posterior fossa approach from February 1988 to October 1995. Tumors
were localized in cerebellar hemisphere in 7 cases (one with extension to
supratentorial notch and another case reaching the cerebello-pontine angle
cistern), in vermis and hemisphere in four, only in vermis in another four.
Resection was total in seven patients, subtotal in other seven, and partial in
one. There was no operative mortality. Aspects regarding biological behavior,
diagnosis, pathological findings, surgery and survival are discussed as well as
prognostic factors.
PMID- 10683691
TI - [Clinical features of transformed migraine].
AB - Most daily headache patients seen in specialized clinics present a past history
of migraine. Some authors refer to it as transformed migraine and emphasize its
milder intensity and clinical characteristics different from migraine. The aim of
this study was to evaluate the clinical presentation of the daily headache in
patients with prior history of migraine. We studied retrospectively 215 patients.
We observed that a significant percentage of the patients presenting the so
called transformed migraine, reported frontal and/or temporal bilateral pain and
had pressure or tightening pain, which is a characteristic of chronic tension
type headache. It emphasizes the loss or changing of the standard migraine
features. The pulsatile pain quality remained as an important feature, specially
for those with intermittent typical migraine attacks.
PMID- 10683692
TI - [Management of arterial hypertension in patients with acute ischemic stroke].
AB - PURPOSE: We aimed with study to assess the current clinical practice about the
management of high blood pressure in patients in the acute phase of ischemic
stroke. We also comment some topics of ischemic stroke treatment. METHODS: A case
report of a patient admitted 8 hours after onset of ischemic stroke and with
blood pressure of 186 x 110 mmHg was presented to 120 surgeons and clinician.
They were asked to decide the best therapeutic option: to increase, decrease or
maintenance blood pressure. RESULTS: Thirty-eight physicians (31.7%) considered
decreasing blood pressure the best therapeutics, 82 (68.3%) considered
maintenance and none decided to increase it (p < 0.05). There was no difference
between the two specialties conduct. The physicians, with more than 10 years of
graduation, had a tendency to decrease the blood pressure (p < 0.05). CONCLUSION:
The maintenance of blood pressure may present a sufficient blood support to
compensate brain flow. A high percentage of the physicians (31.7%) do not know
about the current concepts of therapeutics considering hypertension in acute
ischemic stroke. The development on special units to treat these patients
("stroke units") may eventually decrease the morbimortality rates of ischemic
stroke.
PMID- 10683694
TI - Cerebrovascular disease in newborn infants. Report of three cases with clinical
follow-up and brain SPECT imaging.
AB - The clinical and neurological findings of three neonates with the diagnosis of
cerebrovascular disease are reported. The neuropsychological evaluation disclosed
impairment of fine motor function, coordination, language, perception and
behavioral disturbances. Brain SPECT imaging revealed perfusional deficits in the
three cases.
PMID- 10683693
TI - [Infantile neuroaxonal dystrophy: report of 2 cases].
AB - We describe two cases of infantile neuroaxonal dystrophy, which is a rare,
neurodegenerative disease, with autosomal recessive inheritance. The first case
was an 8 year old boy, with arrested motor and mental development, ataxia and
muscle weakness. On physical examination there was horizontal and vertical
nystagmus, optic disc atrophy, hypotonia; deep tendon reflexes were absent. The
second case was a 1.6 year old boy with arrested motor and mental development,
and seizures. On physical examination there was optic atrophy, hypertonia and
hyperreflexia. Both patients had on sural nerve biopsy neuronal enlargement,
consistent with neuroaxonal dystrophy. Diagnosis without pathological
confirmation with neuroaxonal spheroids is very difficult, because the clinical
picture is variable and the neurophysiological findings are non specific.
PMID- 10683695
TI - [Transitory cerebellar mutism: report of 2 cases].
AB - We present two cases of mutism observed after resection of tumors of the
cerebellum, in two children of the feminine sex, being in the first case of
medulloblastoma and in the second of juvenile astrocytoma. In both patients there
was pre-operative lesion of low cranial nerves. The pathophysiology of the mutism
involves anatomical, vascular and emotional factors, being its essential
characteristics discussed with base in revision of the literature.
PMID- 10683696
TI - Kearns-Sayre syndrome "plus". Classical clinical findings and dystonia.
AB - We present a boy of eight years of age with symptoms of Kearns-Sayre syndrome
(KSS) characterised by ophthalmoparesis, palpebral ptosis, mitochondrial
myopathy, pigmentous retinitis, associated to short stature, cerebellar signs,
cardiac blockade, diabetes mellitus, elevated cerebrospinal fluid protein
concentration, and focal hand and foot dystonia. The skeletal muscle biopsy
demonstrated ragged red fibers, cytochrome C oxidase-negative and succinate
dehydrogenase-positive fibers. The magnetic resonance imaging showed symmetrical
signal alteration in tegmentum of brain stem, pallidum and thalamus.
Mitochondrial DNA analysis from skeletal muscle showed a deletion in
heteroplasmic condition. The association of dystonia to KSS, confirmed by
molecular analysis, is first described in this case, and the importance of
oxidative phosphorylation defects in the physiopathogenesis of this type of
movement disorder is stressed.
PMID- 10683697
TI - Malaria and stroke. Case report.
AB - Malaria is a parasitic disease with high prevalence in several regions of the
world. Infestation by Plasmodium faciparum can, in some cases, affect the central
nervous system producing encephalitis resulting in death or neurological
sequelae. The mechanisms involved in the pathophysiology of the cerebral lesion
are not totally clear and there are currently two theories (mechanical and
humoral) concerning this. We report a case of malaria with an atypical evolution,
with a stroke lesion in the territory of the middle cerebral artery, with no
association with encephalitis. We conclude that the mechanical theory is the one
applicable to this patient.
PMID- 10683698
TI - [Thrombosis of the internal artery secondary to soft palate injury: case report].
AB - Stroke following intraoral trauma is a rare complication of a common childhood
injury. In the literature these complications have been well documented, however
this condition is still infrequent. In order to alert the physicians about this
possible injury we report our experience with one case. Computer tomography and
magnetic resonance imaging evidenced complete occlusion of the internal carotid
artery. Pathogenesis of this oral trauma is discussed.
PMID- 10683699
TI - [Probable Rasmussen's syndrome. Case report].
AB - The syndrome of chronic encephalitis with epilepsy (Rasmussen's syndrome)
typically occurs in children and is characterized by the development of
intractable focal seizures, progressive hemiparesis and intellectual
deterioration. The etiology is unknown, and the pathological abnormalities vary.
We report the case of a 17-year-old boy, presenting with clinical features
typical of probable Rasmussen's syndrome. We discuss the etiology and treatment
for this pathology.
PMID- 10683700
TI - [Comparison of the neuropsychological assessment in a girl with bilateral
cerebrovascular disease (moyamoya) before and after surgical intervention].
AB - Moyamoya is a chronic progressive cerebrovascular disease with characteristic
angiographic findings and a clinical picture with episodes of transient ischemic
attacks, headache, seizures, hemiparesis, which may resolve after surgical
treatment. We describe the case of a girl with the typical findings of the
disease, comparing them before and after surgery with the use of
neuropsychological tests, neurological examination and laboratory tests.
PMID- 10683701
TI - [Autogenic bone plug to seal burr holes: technical note].
AB - Many neurosurgical procedures can be performed by a single burr hole: neuro
endoscopy, microvascular decompression, stereotactic procedures, chronic subdural
haematomas. It is technically difficult to suture and close the dura, located at
the bottom of such holes, which can lately lead to CSF leakage. On the other
hand, the surgical material used to seal the burr holes can be divided in
heterogenic (metal screws, silicon plugs, gelfoam, bone wax, metilmetacrilate,
hydroxyapatite), and autogenic (fat, aponeurosis, muscle, and bone dust from
trephination). The heterogenic group always brings the possibility of foreign
body reaction, which can complicate the procedure lately, ensuing a new surgical
procedure to clean up the area. It also favors infection. We present a simple,
economic, and biologically compatible "autogenic bone plug" to seal burr holes
using the bone dust from the original trephination packed with surgical. The
incidence of CSF fistulae on that procedures performed by a single burr hole
lowered to almost zero, and foreign body reaction was not observed to present.
PMID- 10683702
TI - Cerebral systems in the pathogenesis of endogenous psychoses. 1974.
AB - Mental process imply a harmonious functioning of psychic systems, assembled into
larger units, psychic spheres (Table 1). Their neurophysiological representatives
are brain systems of areas and pathways (Figs 1-4). Under functional and/or
organic disturbances these systems originate the leading mental symptoms (Table
2) characterizing the diverse endogenous psychoses: hence, the latter's
distinctive patterns. Accordingly, understanding and classification of psychoses
should rest on the pathogenic dynamisms, not on clinical description. This is why
Kleist's and Leonhard's conceptions of the endogenous psychoses surpass any other
to exist. Kleist stands among the founders of psychiatry, by describing the
"degeneration psychoses" and many single psychoses, as well as redefining,
isolating and clarifying the progressive ones, later on renamed as schizophrenias
(Table 3). Such pathogenic criterion may also be useful to define mental
conditions other than psychoses, as hysteria, neuroses and psychopathic
inferiority (Tables 4 and 5). One should consider here, besides the psychic
systems and spheres involved, the way they were caught and the corresponding
developmental phase. In Kleist's "degeneration psychoses"--cyclic or episodic
(Table 6) the systems and spheres are disturbed by functional transient processes
due to latent dispositions, while his and Leonhard's schizophrenias (Table 7)
show a rather progressive, deteriorating course. The nature of the disorder is
itself genetically determined, as is either its confinement to one sphere or its
spreading out. The spread out pattern, while exceptional in schizophrenia,
represents a rule for the "degeneration psychoses", in discussant's mind. Both
groups may have symptoms alike by involvement of the same sphere (Table 8), but
proper diagnosis is reached by taking pathogenesis into consideration.
PMID- 10683703
TI - [Homage--Anibal Silveira (1902-1979)].
PMID- 10683704
TI - Reactions to prenatal testing: reflection of religiosity and attitudes toward
abortion and people with disabilities.
AB - To better understand factors associated with prenatal testing decisions, we asked
individuals what they would do if through prenatal testing they discovered that
they (or their partner) were carrying an affected fetus. Respondents were more
uncertain about whether to continue the pregnancy when the fetus was diagnosed as
having Down syndrome than when the fetus had spina bifida or hemophilia and less
certain about continuing a fetus with spina bifida than one with hemophilia.
There was modest support for the hypothesis that negative attitudes toward people
with disabilities would be associated with an increased likelihood of choosing
abortion. Religious affiliation was associated only with the decision concerning
the fetus with hemophilia; church attendance was associated with the decisions
concerning fetuses with all three diagnoses.
PMID- 10683705
TI - Effects of modified orthography on the identification of printed words.
AB - Research has shown that instructional methods involving pairing pictures with
print interfere with identification of written words. Preliminary evidence,
however, indicates that use of modified orthography (where a line drawing is
superimposed upon the printed word) may be effective for reading instruction with
individuals who have mental retardation. In the present study, we used a single
subject parallel treatments design with 4 adults who had moderate to severe
mental retardation. They received reading instruction under two conditions-
traditional and modified orthography. Results showed that traditional orthography
was a more effective method for word identification. The relative advantage of
modified orthography over traditional orthography for individuals with mental
retardation was not supported.
PMID- 10683706
TI - Problem behaviors associated with 15q- Angelman syndrome.
AB - Caregivers of persons with Angelman syndrome completed the Aberrant Behavior
Checklist and Reiss Screen for Maladaptive Behavior. Seventy-three replies were
received, and comparisons were made with other published data. Responses
indicated that 15q- Angelman syndrome is associated with such problems as lack of
speech, overactivity, restlessness, and eating and sleep problems. Episodes of
inappropriate laughter were only reported for 57%, despite being considered a
cardinal feature of the syndrome; eating problems (64%) and a fascination with
water (68%) were reported more frequently. Overactivity was more of a problem for
children; Aberrant Behavior Checklist Factor IV (Hyperactivity) was negatively
correlated with age. Scores were mostly lower than for previously studied
etiological groups. Therapeutic effort should be put into programs to address
these problems.
PMID- 10683707
TI - Models of child-family interactions for children with developmental delays: child
driven or transactional?
AB - Child-driven and transactional models of child-family interactions were tested
with 80 children who had developmental delays and their families. Children's
cognitive competence, personal-social competence, behavior and communication
"hassle," and family accommodations to the children were assessed at child ages
3, 7, and 11. Accommodations were summarized as internal (within the family) and
external (use of outside resources) intensity and types. Results indicate that
the longitudinal relationships between children's cognitive competence, personal
social competence, behavior and communication hassle, and family accommodations
are best explained by a child-driven model. Implications for early intervention
and for the need to consider both child and family outcomes are discussed.
PMID- 10683708
TI - Influence of feature training on the formation of exemplar-specific
representations in children with mental retardation.
AB - Whether exemplar-specific or prototype representations were primarily used by
children with mild mental retardation in a categorization task consisting of two
groups of make-believe animals whose features were ill-defined was examined.
Categorization performance of familiar, prototypic, and novel test phase
exemplars indicated that these children were able to acquire and use both types
of representations. A feature-labeling training procedure, expected to promote
the formation of exemplar-specific representations prior to exemplar
classification, was also incorporated within the current study's design. It was
unclear whether such training had any impact on the formation of exemplar
specific representations.
PMID- 10683709
TI - Behavioural effects of fluoxetine and tianeptine, two antidepressants with
opposite action mechanisms, in rats.
AB - The behavioural effects of two antidepressants with opposite molecular
mechanisms, tianeptine 7-[(3-chloro-6,11-dihydro-6
methyldibenzo[c,f][1,2]thiazepin - 11-yl)amino]heptanoic acid S,S-dioxide, CAS
66981-73-5) 5 mg/kg p.o., a serotonin reuptake enhancer, and fluoxetine (+/-)-N
methyl-3-phenyl-3-[(alpha, alpha, alpha-trifluoro-p- tolyl)oxy]propylamine, CAS
54910-89-3) 5 mg/kg p.o., a serotonin reuptake inhibitor, were compared after
single and prolonged administration (7 and 14 days) once daily). In all
experiments the drug effects were noted at the peak activity time: 30 min after
tianeptine and 60 min after fluoxetine administration. In the immobility time
test both drugs had a shortening effect on immobility time only after prolonged
administration or, in single treatment, after joint administration. A different
pattern was observed in the two compartment test: both antidepressants showed
anxiolytic effects after single and prolonged treatment. However, when the drugs
were given in joint administration, the anxiolytic effects were entirely
abolished after single as well as prolonged treatment. In reference spatial
memory test (food finding time in the maze) tianeptine had no effect, whereas
fluoxetine caused, after single and prolonged treatment, a very marked
improvement of reference memory. Joint administration of both drugs resulted in
worsening the effects on memory in comparison to fluoxetine alone, but the
results were still significantly better vs. control. In the test for sedative
action (in the Activity Meter AM-1, where the movements of the animals are
counted electronically) only after prolonged treatment with tianeptine a
diminished locomotor activity could be observed. It is concluded that in the
action of the drugs (beside the effect on serotonin uptake) other mechanisms must
play an important role. The diminished locomotor activity after tianeptine
suggests an influence on the dopaminergic or GABA-Receptor system.
PMID- 10683710
TI - Muscarinic properties of compounds related to arecaidine propargyl ester.
AB - A series of new analogues of the arecaidine propargyl ester (CAS 35516-99-5),
APE, 1a) with alcohols consisting of 4 or 5 carbon atoms were investigated at
muscarinic receptor subtypes. The muscarinic activity of the quaternary and
tertiary salts of the APE-related compounds were assayed on the isolated guinea
pig ileum (M3 receptor subtype) and guinea-pig left atria (M2 receptor subtype)
as well as on rabbit isolated vas deferens (M1 receptor subtype). The structural
variations made in the APE molecule, replacing the triple bond in the ester side
chain with structures such as double bond, an allene moiety, a single bond, a
cyclopropyl group or two triple bonds should alter the selectivity and potency in
favour of the M2 subtype. Enhanced, though modest, selectivity for M2 receptors
was achieved with the 2-butynyl ester 2a. The other structural variations
resulted in a loss of potency, but not necessarily of efficacy.
PMID- 10683711
TI - Neurosedative and antioxidant activities of phenylpropanoids from ballota nigra.
AB - Ballota nigra is a European plant known for its neurosedative properties. In this
study, the ability of five phenylpropanoids (verbascoside, forsythoside B,
arenarioside, ballotetroside, and caffeoyl malic acid) isolated from a
hydroalcoholic extract, to bind to benzodiazepine, dopaminergic, and morphinic
receptors was investigated. To carry out these studies, affinity tests with rat
striata, entire brains and receptor rich preparations were employed. In addition,
the phenolic aspect of these five phenylpropanoid esters led to investigate
antioxidant activities using cell-free experiments and cellular experiments
including isolated polymorphonuclear neutrophils (PMN). Effects of
phenylpropanoid esters against reactive oxygen species as superoxide anion,
peroxide hydrogen, hypochlorous acid and hydroxyl radical were tested. These
molecules are liberated by PMN during inflammatory disorders, so that
reproduction of this process in vitro stimulating PMN by chemical stimulants was
undertaken. Results show that four of the five compounds are able to bind to the
studied receptors. Inhibitory concentrations at 50% were determined and vary from
0.4 to 4.7 mg/ml. This may be in relation with the Ballota nigra known
neurosedative activities. Results concerning antioxidant investigations evidence
an ability to scavenge reactive oxygen species. Inhibitory concentrations at 50%
obtained are comparable to those of known antioxidant drugs (mesna or N-acetyl
cysteine). Moreover, the use of different stimuli having various pathways of
action on PMN oxidative metabolism permits to establish that each phenylpropanoid
ester has its own particular way of action by using proteine kinase C or
phospholipase C pathways.
PMID- 10683712
TI - Effects of tramadol and tilidine/naloxone on oral-caecal transit and pupillary
light reflex.
AB - As has been demonstrated in binding studies the two opioids tilidine (CAS 27107
79-7)/naloxone (CAS 357-08-4) and tramadol (CAS 36282-47-0) differ in regard to
their affinities to the opioid receptor site. Therefore it is of interest to
evaluate whether such a difference in opioid affinity is also seen in the
pharmacological effects of clinically relevant doses in man. Following
institutional approval by the local ethical committee and informed consent, 12
volunteers received oral doses of tramadol (100 mg), tilidine/naloxone (100 mg)
and placebo, respectively, in a randomized, double-blind cross-over design. In
order to determine the degree of constipation, oral-caecal transit time was
measured using the H2-exhalation test. Additionally, in order to evaluate a
centrally mediated effect, the response of the pupil to light was quantified
using the pupillary light reflex technique. Both, peripheral and central mediated
effects were compared to placebo. Tramadol as well as tilidine/naloxone induced a
significant (p < 0.05) prolongation of oral-caecal transit when compared to
placebo. However, prolongation of oral-caecal transit was significantly longer in
the tilidine/naloxone (p < 0.05) than in the tramadol group. Compared to
tramadol, the pronounced constipating effect of tilidine/naloxone is likely to be
due to the 10 fold higher affinity of that drug to the peripheral opioid receptor
sites in the intestinal tract, which are responsible for normal propulsion. Such
difference in binding is underlined by a central effect, the pupillary light
reflex response. The amount of constriction of the iris to light was reduced
after both opioids. Again, tilidine/naloxone significantly reduced (p < 0.001)
the pupillary light reflex when compared to tramadol. Other side effects such as
tiredness, nausea, emesis and dry mouth were more often reported after
tilidine/naloxone than after tramadol (40% versus 15%; p < 0.05). Vertigo and
perspiration were more often reported after tramadol than after after
tilidine/naloxone (58% and 78% versus 8%; p < 0.01). All these data support the
findings that while tramadol is considered an opioid, it does not mediate its
main clinical relevant properties via binding at the opioid receptor. More
likely, due to its monoaminergic reuptake mechanism, to a lesser extent opioid
like effects are induced.
PMID- 10683713
TI - Preliminary acute and subchronic toxicity studies of GLG-V-13, a novel class III
antiarrhythmic agent, in mice.
AB - The acute and subchronic toxic effects of GLG-V-13 (3-[4-(1H-imidazol-1
yl)benzoyl]-7-isopropyl-3,7-diazabicyclo[3.3.1]nona ne dihydroperchlorate, CAS
155029-33-7), a novel class III with some class Ib antiarrhythmic activity, were
investigated in mice. The estimated LD50 for GLG-V-13 given orally were 419 mg/kg
for male mice and 383 mg/kg for female mice, respectively. The acute toxic signs
appeared to be of the central nervous system in origin. Four groups of mice (15
per sex, group and dose) were fed daily with diets containing GLG-V-13 for 90
consecutive days. The equivalent daily doses were 0, 22, 50 and 121 mg/kg/day and
0, 27, 60 and 136 mg/kg/day for male and female mice, respectively. All of the
mice survived. Food consumption was decreased. However, mean body weight and body
weight gain were not significantly changed. Gross pathological changes,
especially in the lungs and liver, were found in the middle and high dose groups.
Consistent increased mean corpuscular hemoglobin concentration and decreased mean
corpuscular hemoglobin were observed in all dose groups. Hepatocellular necrosis
was found in both male and female mice treated with the drug and was dose
dependent. Marked vacuolation of the X zone in the adrenal gland with mild to
moderate deposition of ceroid pigments (brown degeneration) was observed in
female mice. Lesions in the kidneys and adrenal glands may be a possible reason
for changes in serum sodium and potassium ions concentrations leading to an
increase in water intake. A significant reduction in cholesterol in the high dose
group may be a favorable pharmacological effect of GLG-V-13. The data from the 90
day subchronic toxicity studies indicate that GLG-V-13 appears to have limited
systemic toxicity potential.
PMID- 10683714
TI - [The effect of a nasal spray consisting of a standardized mixture of citrus limon
(succus) and an aqueous extract of Cydonia oblongata (fructus) on nasal
mucociliary clearance].
AB - In a three-way-crossover study in 18 healthy male and female subjects aged from
20 to 49 years the influence of a 1% and 3% solution of a standardized
composition of Citrus limon, succus, and extract from Cydonia oblonga, fructus
(Gencydo) on the intranasal mucociliar clearance was investigated after multiple
administration. The pH of the solution was about pH 2.3-3.2. The dose regimen
consisted of 20 puffs (0.13 ml per puff) in each nostril within 24 h, which was
by factor 3-10 higher than the usual therapeutic dosage of 2-6 puffs per nostril
and 24 h. The mucociliar transport time was measured by a modified saccharin
test, where 1 microliter of a 3-molar aqueous sodium saccharinate solution was
applicated at the inferior nasal turbinate 1 cm from its anterior end using a
glass capillary microliter pipet. This test was performed at screening
examination, before each administration period, directly after each 24 h
treatment period and 24 h after the end of each treatment. The time of initial
taste perception could be defined with high precision by the volunteer since it
appeared very spontaneously. Neither after intranasal administration of the 1%
and 3% Citrus/Cydonia solution nor after placebo solution a prolongation of the
perception time was found. It could be concluded that there is no measurable
influence of the test products on the intranasal ciliar function.
PMID- 10683715
TI - Pharmacokinetics of diclofenac after oral administration of its potassium salt in
sachet and tablet formulations.
AB - This paper reports the results of a pharmacokinetic study involving 24 healthy
volunteers and designed to characterise the rate and extent of diclofenac
absorption after the administration of a single dose of diclofenac (CAS 15307-86
5) potassium salt 50 mg in sachet (Voltfast) and tablet (Cataflam) formulations.
Timed plasma concentrations of diclofenac during a 12-h-period after dosing were
measured by means of HPLC with UV detection at 275 nm and a quantification limit
of 10 ng/ml; the method was fully validated for pharmacokinetic purposes. These
plasma concentrations were used to calculate Cmax, tmax, trapezoidal AUC0-t and
AUC0-infinity and t1/2 by means of noncompartmental analysis. Cmax and tmax are
the parameters expressing the rate of absorption, whereas the AUCs reflect the
extent of absorption. The rate of absorption with the sachets proved to be very
fast, reaching peak values at 10 min in seven subjects and at 15 min in the
remaining subjects: mean time was 13.68 min, with concentrations at 5 min being
38% of Cmax. The average time to peak concentration with the tablets was 53.10
min. The extent of absorption of the sachets and tablets was similar, with AUC0
infinity values of respectively 1362 and 1214 ng.ml-1.h, and a 90% confidence
interval 1.05-1.20. The highly soluble potassium salt of diclofenac was rapidly
absorbed, especially in its sachet formulation, and thus appears to be an
invaluable analgesic agent that is particularly useful for quick pain relief.
PMID- 10683716
TI - Synthesis and biological evaluation of indole containing derivatives of
thiosemicarbazide and their cyclic 1,2,4-triazole and 1,3,4-thiadiazole analogs.
AB - New indolic derivatives of thiosemicarbazides and some cyclic 1,2,4-triazol-5
thione analogs were synthesized. The newly synthesized compounds as well as some
indole containing thiosemicarbazides, 1,2,4-triazoles and 1,3,4- thiadiazoles,
which have been reported previously, were investigated for antimicrobial,
antifungal and antiphage activity. Certain thiosemicarbazide derivatives and the
corresponding cyclic 1,2,4-triazole analogs showed selective antimicrobial or
antifungal activity, while they lack any antiphage activity. Antiphage activity
was detected for one compound, bearing the 1,3,4-thiadiazole nucleus. The
selectively active compounds cover a wide range of lipophilicity. Structure
activity relations show a remarkably similarity in the antimicrobial and
antifungal behaviour of the thiosemicarbazides and their cyclic triazo-thien-5-yl
analogs, while alpha-naphtyl substitution in the non indolic portion of the
molecule is favorable. C5 substitution on the indolic nucleus may also be
critical for selective activity.
PMID- 10683717
TI - Synthesis, antibacterial, antifungal and anti-HIV evaluation of Schiff and
Mannich bases of isatin and its derivatives with triazole.
AB - Isatin (indole 2,3-dione) and its 5-chloro and 5-bromo derivatives have been
reacted with 3-(4'-pyridyl)-4-amino-5-mercapto-4-(H)-1,2,4-triazole to form
Schiff bases and the N-Mannich bases of these compounds were synthesised by
reacting them with formaldehyde and several secondary amines. Their chemical
structures have been confirmed by means of their IR, 1H-NMR data and by elemental
analysis. Investigation of antimicrobial activity of compounds was done by agar
dilution method against 27 pathogenic bacteria, 8 pathogenic fungi and anti-HIV
activity against replication of HIV-1 (III B) in MT-4 cells. Among the compounds
tested 1-(piperidinomethyl) 5-bromo 3-[3'-(4"-pyridyl)-5'-mercapto-4'-(H)
1',2',4'-triazol 4'-yl]imino isatin showed the most favourable antimicrobial
activity.
PMID- 10683718
TI - Pharmacokinetics and tissue distribution of rifametane, a new 3-azinomethyl
rifamycin derivative, in several animal species.
AB - Single and repeated dose experiments in mice, rats, dogs and monkeys are reported
in this study to assess the pharmacokinetics and tissue distribution of
rifametane, a new semi-synthetic rifamycin with the chemical formula 3-[(1
diethylaminoethylidene)azinomethyl]rifamycin SV (CAS 94168-98-6, SPA-S-565). All
the kinetic tests were carried out in comparison with known rifamycin
derivatives, as rifampicin (CAS 13292-46-1) or rifamycin SV (CAS 6998-60-3). Mice
received single i.v. and oral administration of 10 mg/kg of rifametane or of
rifampicin and serum samples were obtained up to 96 h after dosing. The two
antibiotics showed similar peak of serum concentrations, but rifametane showed a
longer half-life and higher AUC values. In an additional experiment, the
tissue/serum ratio after the 10 mg/kg oral dose was lower than unity for lungs
and kidneys, while the liver/serum ratio exceeded the unity at all sampling
times. After 4 weeks of once weekly administration measurable serum and tissue
concentrations were observed, and after twice weekly administration for the same
time period some blood and tissue accumulation was seen. Rats were treated with a
single intravenous injection of 20 mg/kg of rifametane or rifampicin and with
single oral or i.m. administration of 60 mg/kg of rifametane or reference
standards (rifampicin and rifamycin SV resp.), in two separate trials. The serum
half-life of the test antibiotic after i.v. dose was 6 times longer than that of
rifampicin and the serum concentrations of rifametane after oral and i.m. doses
were higher and longer-lasting than those of the reference compounds. Repeated
daily administrations of rifametane at three dose levels (3, 10, 30 mg/kg p.o.)
for 4 weeks induced very high serum and liver concentrations. Dogs received a
single oral dose of 1.25 mg/kg of rifametane or 2.5 mg/kg of rifampicin. The
serum half-life of rifametane resulted 3 times longer than that of rifampicin.
Remarkable serum and tissue concentrations were observed after 3-4 weeks of daily
oral administration of rifametane at 3, 10, 30 mg/kg dose. Monkeys were given
single oral or i.m. administration of 30 mg/kg of rifametane or reference
standards (oral rifampicin and i.m. rifamycin SV). The serum concentrations after
rifametane were higher and more sustained than those of reference compounds and
the half-lives of the test antibiotic were about 2.5 (p.o.) to 6 times (i.m.)
longer. The urine excretion of rifametane after a single intravenous dose in rats
and a single oral dose in dogs was very low, while rifampicin had a little higher
urine concentrations.
PMID- 10683719
TI - Effect of quercetin, caffeic acid and caffeic acid phenylethyl ester, solubilized
in non-ionic surfactants, on histamine release in vivo and in vitro.
AB - A practical hindrance in using many therapeutic agents is their limited
solubility in aqueous matrixes. This is usually overcome by incorporating the
active compounds in a matrix, with the aid of a non-ionic surfactant. Three water
insoluble natural polyphenols with inherent biological activity, quercetin (CAS
117-39-5), caffeic acid and caffeic acid phenylethyl ester, were solubilized in
water, with the aid of Tween 80 (an esterified and polyethoxylated derivative of
sorbitan), Solutol HS15 (a polyethoxylated derivative of 12-hydroxy-stearic
acid), Cremophor RH40 (a ricinoleic acid derivative) or Cremophor EL and the
effect of the solubilized polyphenols on histamine release was studied in vitro
(mast cells) and in vivo in the rat. In vivo Cremophor EL alone increased, and
Tween 80 decreased histamine plasma levels. All four groups injected with
solubilized quercetin exhibited a decrease in their plasma histamine levels.
Caffeic acid solubilized in Cremophor RH40 decreased histamine levels, too. In
vitro Tween 80 increased histamine release in a dose-dependent mode. Quercetin in
vitro inhibited histamine release in all solubilizers used. It is concluded that
the ability of the studied polyphenols to release histamine is not only depending
on the condition of the storage vesicles in the mast cells, but also on the
surfactant used to solubilize them.
PMID- 10683720
TI - General pharmacology studies on beta-domain deleted recombinant factor VIII.
AB - beta-Domain deleted recombinant factor VIII (GC-rAHF), newly developed by Korea
Green Cross Co., is a novel therapeutic for hemophiliacs and is currently under
clinical evaluation. The general pharmacological properties of this drug were
evaluated using mice, rats, guinea pigs and rabbits. Intravenous doses of 5 to
500 IU/kg were assayed in several tests to analyze their effects in vivo on
various systems. The effect of the substance under study was also tested in vitro
on isolated guinea pig ileum preparations at final concentrations of 5 to 50
IU/kg. The result of this study showed that GC-rAHF did not affect general
behavior in the Irwin test. Similarly the drug was not found to affect neither
normal body temperature nor the spontaneous activity in mice. In addition, it was
not found to induce pharmacologically significant alterations of the
cardiovascular and respiratory parameters in rats. No effects were observed
either in the pentobarbital sodium-induced sleep-induction time and duration, in
writhing test or in the test of pentetrazole-induced convulsion. Finally, the
tested drug did not modify the gastrointestinal motility, acetylcholine or
histamine-induced contraction of the isolated guinea pig ileum, nor gastric
secretion. The results demonstrated that GC-rAHF has no effects on the central
nervous, cardiovascular, respiratory and digestive systems in the doses of 5, 50
and 500 IU/kg in vivo and 5, 10, 50 and 100 IU/kg in vitro.
PMID- 10683721
TI - Biomedical technology in Franconia.
AB - Medical instrumentation and biotechnology business is developing rapidly in
Franconia. The universities of Bayreuth, Erlangen-Nurnberg, and Wurzburg hold
upper ranks in biomedical extramural funding research. They have a high
competence in biomedical research, medical instrumentation, and biotechnology.
The association "BioMedTec Franken e.V" has been founded at the beginning of 1999
both to foster the information exchange between universities, industry and
politics and to facilitate the establishment of biomedical companies by means of
science parks. In the IGZ (Innovation and Foundation Center Nurnberg-Furth
Erlangen) 4,500 square meters of space are currently shared by 19 novel
companies. Since 1985 60 companies in the IGZ had a total turnover of about 74
Mio Euro. The TGZ (Technologie- und Grunderzentrum) in Wurzburg provides space
for 11 companies. For the specific needs of biomedical technology companies
further science parks will be set up in the near future. A science park for
medical instrumentation will be founded in Erlangen (IZMP, Innovations- und
Grunderzentrum fur Medizintechnik und Pharma in der Region Nurnberg, Furch,
Erlangen). Furthermore, a Biomedical Technology Center and a Research Center for
Bicompatible Materials are to be founded in Wurzburg and Bayreuth, respectively.
Several communication platforms (Bayern Innovativ, FORWISS, FTT, KIM, N-TEC
VISIT, TBU, WETTI etc.) allow the transfer of local academic research activities
to industrial utilization and open new co-operation possibilities. International
pharmaceutical companies (Novartis, Nurnberg; Pharmacia Upjohn, Erlangen) are
located in Franconia. Central Franconia represents a national focus for medical
instrumentation. The Erlangen settlement of the Medical Engineering Section of
Siemens employs 4,500 people including approximately 1,000 employees in the
Siemens research center.
PMID- 10683722
TI - Multiple site mutagenesis with high targeting efficiency in one cloning step.
PMID- 10683723
TI - Gene replacement in gram-negative bacteria: the pMAKSAC vectors.
PMID- 10683724
TI - Direct observation of GFP gene expression transduced with HSV-1/EBV amplicon
vector in unfixed tumor tissue.
PMID- 10683725
TI - Dominant positive and negative selection using luciferase, green fluorescent
protein and beta-galactosidase reporter gene fusions.
PMID- 10683726
TI - Direct reprobing with anti-beta-actin antibody as an internal control for western
blotting analysis.
PMID- 10683727
TI - Lipopolysaccharide affinity measurement by scintillation proximity assay:
application to human heparin binding protein.
PMID- 10683728
TI - Suitability of a unique 16S rRNA gene PCR product as an indicator of Gardnerella
vaginalis.
PMID- 10683729
TI - Expression of TetC fusion proteins from Salmonella in a gaseous environment that
models conditions found in mammalian tissues.
PMID- 10683731
TI - Transfection of cultured mesenchyme cells isolated from embryonic chick limb buds
and facial primordia.
PMID- 10683730
TI - Recovery of protein kinases from renatured SDS-polyacrylamide gels for
biochemical studies.
PMID- 10683732
TI - Fast, qualitative analysis of p53 phosphorylation by protein kinases.
PMID- 10683733
TI - Get your bioinformatics on the Web!
PMID- 10683734
TI - Photo-cross-linkable oligonucleotide probes for in situ hybridization assays.
AB - In situ hybridization techniques have been an important research tool since first
introduced 30 years ago, and more recently clinical applications have been
expanding greatly. Still, further improvements in the assay sensitivity and
protocols that are amenable to routine clinical use are desired. We use a novel
photo-cross-linking technology to irreversibly bind short oligonucleotide probes
to the target sequence following a hybridization period. The cross-linking agent
is incorporated into the backbone of the probe and is activated to react with
pyrimidines in the opposite strand by near-UV (300-370 nm) irradiation. By
locking the probe to the target, very stringent wash conditions can be used that
would otherwise completely remove probes that are hybridized but not cross-linked
to the target. Consequently, the probe-specific signal is maximized, while the
background signal is minimized to the greatest extent possible with the
stringency of the wash. The use of short, photo-cross-linkable probes presents a
new strategy for maximizing the sensitivity of probe hybridization or signal
amplification-based in situ techniques.
PMID- 10683735
TI - Comparison of lipid-mediated and adenoviral gene transfer in human monocyte
derived macrophages and COS-7 cells.
AB - Lipid-mediated transfection was compared to adenoviral-mediated gene transfer in
COS-7 cells as well as human monocyte-derived macrophages (HMDM). For this
purpose, we monitored enhanced green fluorescent protein (EGFP) expression by
fluorescence microscopy and quantified gene transfer by competitive PCR.
Transfection of COS-7 cells with a novel lipid formulation for DNA transfer was
highly effective in COS-7 cells. On average, 30% of the cells were fluorescent 48
h after transfection. In HMDM, the same formulation resulted in the expression of
EGFP in less than 0.5% of cells. We measured plasmid DNA by quantitative PCR in
lipid-transfected macrophages and found that each macrophage contained on average
2 fg of plasmid DNA 24 h after transfection, that is, more than 400 molecules of
plasmid DNA entered each cell. Despite the high level of reporter DNA in lipid
transfected cells, expression of the fluorescent protein was suppressed in more
than 99.5% of the macrophages. We also used adenoviral gene transfer to introduce
the foreign DNA into both COS-7 cells and HMDM. Even though the multiplicity of
infection was less than 30, expression of EGFP was observed in nearly all COS-7
cells and in more than 80% of HMDM 48 h after transfection. Despite major
advances in the field of lipid-mediated transfection of HMDM, the lipid
formulations that are available commercially cannot compete with the efficiency
of adenoviral gene transfer.
PMID- 10683736
TI - Modified differential display technique that eliminates radioactivity and
decreases screening time.
AB - Several techniques are available that detect variations in gene expression
between cellular populations. These include subtractive hybridization (SH),
differential colony hybridization (DCH) and mRNA differential display, all based
on the analysis of mRNA. The first two techniques, however, are limited because
they require large amounts of mRNA for SH or several rounds of screening for DCH.
Differential display overcomes both of these limitations. However, the
conventional differential display technique is plagued by false positives and is
labor intensive. The identification of genes that are truly differentially
expressed, therefore, becomes a formidable task. We describe a modified
differential display technique that overcomes the limitations of the conventional
technique. This new technique eliminates a source of false positives, decreases
the time required to screen a set of primers and reduces the use of
radioactivity.
PMID- 10683737
TI - Specificity-enhanced hot-start PCR: addition of double-stranded DNA fragments
adapted to the annealing temperature.
AB - A new method to produce hot-start conditions in PCR is described. Short double
stranded DNA fragments were found to inhibit the activity of DNA polymerases from
Thermus aquaticus and Thermus flavus. This inhibition is not sequence specific,
but exclusively dependent on the melting temperature of the fragments as shown by
its correlation to their melting curves as measured. This property is exploited
by adding fragments of the appropriate length to the PCR mixture during the
reaction setup and thereby preventing the DNA polymerases from extending primers
annealed nonspecifically at lower than the optimal temperature. By amplifying ten
copies of phage lambda DNA in the presence of 2 micrograms of nonspecific DNA, it
is shown for three different primer pairs how the melting temperatures of the
double-stranded DNA fragments have to be adapted to the cycle profiles to obtain
predominantly specific products in the 0.5 microgram range.
PMID- 10683738
TI - New protocol for DNA extraction of stool.
AB - Present methods for DNA isolation of stool have various limitations such as the
amount of stool used, the requirement of lavage fluids or the use of fresh stool.
In this paper, a new method is described for the isolation of human nucleic acids
from stool, which is independent from the moment of collection. Fecal samples as
dry as possible were collected from 75 patients; two grams of stool were mixed
with a lysis buffer containing phenol. DNA yields of crude stool were variable
and ranged from 9-1686 micrograms/g of feces. With dot blots in 9 of the 75
cases, the human DNA was identified and ranged from 0.06%-46%. In the remaining
66 cases, human genomic DNA was detected by nested PCR, using human K-ras gene
amplification as an example. Amplification products were confirmed for human K
ras with the exonuclease-amplification coupled capture technique (EXACCT). In
conclusion, the developed DNA isolation method can be used for the study of large
numbers of stool samples, is independent of the age or method of stool collection
and is suitable for large-scale screening studies.
PMID- 10683739
TI - Isolation and purification of functional total RNA from woody branches and
needles of Sitka and white spruce.
AB - The isolation of intact, functional RNA from conifer spp. is not easy, especially
from those tissues that are heavily lignified and characterized by a low number
of living cells. An efficient procedure for isolating RNA from combined wood and
bark tissues of conifers was developed based on a protocol optimized for the
extraction of RNA from pollen and one for the isolation of RNA from woody stems.
This protocol does not involve the use of phenol, and no ultracentrifugation was
required. In addition, the protocol overcame the problems of RNA degradation and
low yield due to oxidation by polyphenolics and co-precipitation with
polysaccharides, both of which are abundant components in conifer bark tissues.
The isolated RNA was of high quality and undegraded as gauged by
spectrophotometric readings and electrophoresis in denaturing agarose gels.
Quality was further assessed through the subsequent use of the RNA in reverse
transcription and RT-PCR, indicating that it could be used for a number of
downstream purposes including Northern blot hybridization and cDNA library
construction. Using this modified protocol, 80-150 micrograms of RNA was
routinely obtained from 1 g of fresh material. This protocol was also used for
the isolation of RNA from needles of spruce spp., from which 750-950 micrograms
RNA per gram of starting material could routinely be obtained.
PMID- 10683740
TI - Cross-contamination limits the use of recycled anion exchange resins for
preparing plasmid DNA.
PMID- 10683741
TI - Trace contamination following reuse of anion-exchange DNA purification resins.
PMID- 10683742
TI - PNA-dependent gene chemistry: stable coupling of peptides and oligonucleotides to
plasmid DNA.
AB - Two approaches are described for stably conjugating peptides, proteins and
oligonucleotides onto plasmid DNA. Both methods use a peptide nucleic acid (PNA)
clamp, which binds irreversibly and specifically to a binding site cloned into
the plasmid. The first approach uses a biotin-conjugated PNA clamp that can be
used to introduce functional biotin groups onto the plasmid to which streptavidin
can bind. Atomic force microscopy images of linearized plasmid show streptavidin
localized at the predicted PNA binding site on the DNA strand. Peptides and
oligonucleotides containing free thiol groups were conjugated to maleimide
streptavidin, and these streptavidin conjugates were bound to the biotin-PNA
labeled plasmid. In this way, peptides and oligonucleotides could be brought into
stable association with the plasmid. A second approach used a maleimide
conjugated PNA clamp. Methods are described for conjugating thiolated peptides
and oligonucleotides directly to the maleimide-PNA-DNA hybrid. This
straightforward technology offers an easy approach to introduce functional groups
onto plasmid DNA without disturbing its transcriptional activity.
PMID- 10683743
TI - Photoreduction of monoclonal antibodies for conjugation and fragmentation.
AB - The conjugation of enzymes, fluorescent or radioactive labels, cross-linkers and
other moieties to antibodies is a commonly performed procedure in biochemical
research. Using reduced disulphides, conjugation can be an inconvenient,
multistep, time- and material-consuming process. We have developed a reduction
technique based on UV irradiation, which lacks these drawbacks. Antibodies are
irradiated in a sealed vial for a few minutes by a common laboratory UV source in
the presence of stannous ions, following the depletion of atmospheric oxygen. The
preparation may subsequently be conjugated with thiol-reactive probes such as
maleimide derivatives, with no need for any prior purification or concentration.
This simple, rapid and effective reduction and conjugation process results in a
fully functional immunoglobulin conjugate that can be used for a variety of
biochemical applications.
PMID- 10683744
TI - Approaches to detecting false positives in yeast two-hybrid systems.
AB - While many novel associations predicted by two-hybrid library screens reflect
actual biological associations of two proteins in vivo, at times the functional
co-relevance of two proteins scored as interacting in the two-hybrid system is
unlikely. The reason for this positive score remains obscure, which leads to
designating such clones as false positives. After investigating the effect of
over-expressing a series of putative false positives in yeast, we determined that
expression of some of these clones induces an array of biological effects in
yeast, including altered growth rate and cell permeability, that bias perceived
activity of LacZ reporters. Based on these observations, we identify four simple
strategies that can assist in determining whether a protein is likely to have
been selected in a two-hybrid screen because of indirect metabolic effects.
PMID- 10683745
TI - Cell-free synthesis and affinity isolation of proteins on a nanomole scale.
AB - The performance of conventional cell-free gene expression systems based on the
Escherichia coli S30 extract can be significantly improved by using expression
vectors that encode viral structural elements known to enhance translation in
vivo and to protect mRNA from ribonuclease action. The expression vectors
reported here are designed to produce a functionally active protein carrying the
Strep-tag oligopeptide at its C-terminus. They can be used in translation,
transcription-translation or replication-translation reactions. Depending on its
type, the reaction yields up to 40 micrograms per mL, or about 1 nmol of a
standard protein. The presence of Strep-tag allows the synthesized protein to be
easily isolated on a streptavidin-agarose column under mild conditions and the
entire procedure to be completed within one working day. The results show that
standard low-cost, cell-free systems can serve for rapid preparation of purified
proteins in amounts that can satisfy a number of needs of a research laboratory.
PMID- 10683746
TI - Detection of plant genes using a rapid, nonorganic DNA purification method.
AB - We have developed a simple procedure for the preparation of plant genomic DNA
using FTA paper. Plant leaves were crushed against FTA paper, and the genomic DNA
was purified using simple, nonorganic reagents. The 18S rRNA gene and the gene
encoding the ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit
(rbcL) from the chloroplast genome were detected by PCR amplification of DNA on
FTA paper. DNA amplification was successful using extracts from 16 dicot and
monocot plants. Studies of specific plant extracts revealed that extracts of leaf
samples could be collected and stored at room temperature on FTA paper without a
decrease in the DNA amplification success rate for more than a month. Both the
18S RNA gene and the rbcL gene were detected in the genomic DNA isolated from
various soybean cultivars stored in this manner. Furthermore, by modestly
increasing the number of cycles of DNA amplification, we were able to detect the
uidA gene in transgenic tobacco and rice leaves as well as a single copy gene
linked to the resistance gene of cyst nematode race 3 using genomic DNA isolated
on FTA paper. These results demonstrate that genomic DNA isolated using FTA paper
can be used for the detection of plant genes, from a wide range of plants with
either high or low gene copy number and of either nuclear or cytoplasmic origin.
PMID- 10683747
TI - New Cleavase Fragment Length Polymorphism method improves the mutation detection
assay.
AB - Cleavase Fragment Length Polymorphism (CFLP) analysis is a convenient, accurate
and highly sensitive method for the detection and localization of nucleic acid
mutations. The assay is well suited for high-throughput screening and can be used
to detect mutations in known and unknown nucleic acid samples. A recent
improvement in the CFLP assay termed "temperature ramping" or "ramping" is
reported here. This procedural improvement eliminates the need for time and
temperature optimizations before the actual sample analysis. In this study, we
compare the CFLP ramping procedure to the conventional CFLP optimization
procedure and demonstrate equal, and in some cases improved, detection of point
mutations. With ramping, CFLP reactions are identical for all DNA fragments
analyzed, which allows for increased sample throughput, decreased assay time and
lower overall cost.
PMID- 10683748
TI - [Cardiovascular disorders in Parkinson disease are underrated].
PMID- 10683749
TI - [Orofaciodigital syndrome--a new variant? Psychiatric, neurologic and
neuroradiological findings].
AB - Oral-facial-digital (OFD) syndromes are a heterogeneous group of inherited
syndromes that have in common anomalies of the face (median cleft lip), the
tongue (bifid or lobulated tongue with harmartomas), and the digits
(brachydactyly, polydactyly, syndactyly). Due to more or less subtle clinical
features, at least seven causally different entities can be identified: 1) OFDS
I; 2) OFDS II (Mohr syndrome); 3) OFDS III; 4) OFDS with tibial anomalies (OFDS
IV); 5) OFDS V (Thurston syndrome); 6) OFDS VI (Varadi syndrome); and 7) OFDS VII
(Whelan syndrome). The neuro-psychiatric clinical observations and MRI findings
of a 40 year old woman with a OFD syndrome are described. The observed findings
(leukoaraiosis, epilepsy, major depression) in combination with a proven OFD
syndrome possibly reflect a new type of OFD syndrome.
PMID- 10683750
TI - [German research institute/Max-Planck Institute for psychiatry].
AB - The Deutsche Forschungsanstalt fur Psychiatrie (DFA, German Institute for
Psychiatric Research) in Munich was founded in 1917 bel Emil Kraepelin. For a
long time it was the only institution in Germany entirely devoted to psychiatric
research. Because of its strictly science-oriented and multidisciplinary approach
it also became a model for institutions elsewhere. Kraepelin's ideas have
certainly had a strong influence on psychiatry in the twentieth century. The
fascinating and instructive history of the DFA reflects the central issues and
determinants of psychiatric research. First, talented individuals are needed to
conduct such research, and there was no lack in this regard. Second, the various
topics chosen are dependent on the available methods and resources. And finally,
the issues addressed and the ethical standards of the researchers are heavily
dependent on the zeitgeist, as is evident in the three epochs of research at the
DFA, from 1917 to 1933, from 1933 to 1945, and from the postwar period to the
present. With the introduction of molecular biology and neuroimaging techniques
into psychiatric research a change in paradigm took place and a new phase of the
current epoch began.
PMID- 10683751
TI - [A century of German psychiatry (1899-1999)].
AB - The century of German psychiatry between 1899 and 1999 was shaped by creative and
catastrophic contrasts. For the beginning and the end these contrasts and the
tensions between them can be personalized by the names of Kraepelin and Freud.
During the time in between there was the unfolding of the ideas of schizophrenia,
classical psychiatry, psychotherapy, structural theories, pharmaco-psychiatry,
anthropological psychiatry, social psychiatry and of many other creative theories
and methods in manyfold ways. But during the time in between there was also Nazi
psychiatry. In historical perspective not only the murdering of countless
psychiatric patients was a disaster. Expulsion, intellectual exhaustion, death of
many psychiatrists and war damages too had catastrophic consequences. Only
seemingly as a paradox Nazi time and its sequels were followed by global
acknowledgement for and globalization of German psychiatry. But this period has
come to an end too. Resources and man power are available, the path is free for
completely new ideas.
PMID- 10683752
TI - [Psychiatric classification. Basic idea and development of an ongoing process].
AB - Whereas the present internationally accepted systems appear like a radical break
with the psychiatric tradition at first sight, a closer look reveals that there
is in fact a continuity between traditional and modern classification systems:
The programmatic idea behind their development is still the same as the one that
was first formulated by K. Kahlbaum and introduced to psychiatry by E. Kraepelin.
And indeed, those changes in modern systems that appear new were developed
because the responsible commissions kept in line with this German tradition. The
present paper reviews the development of classifications in psychiatry from their
beginning to today and underlines the reasons why the true adequacy of current
systems will only show in the next millennium.
PMID- 10683753
TI - [Comment on R. Thomasius, M. Schmolke, D. Kraus: MDMA ("Ecstasy") use--an
overview of psychiatric and medical sequelae].
PMID- 10683754
TI - Vitamin E and ATPases: protection of ATPase activities by vitamin E
supplementation in various tissues of hypercholesterolemic rats.
AB - It has been shown that the lipid composition of plasma membrane can be modified
in vivo by dietary fat. It has also been observed that an increase in the
cholesterol content of plasma membranes results in decreased activities of
ATPases. In the present study, we evaluated the changes in the activities of
ATPases from erythrocytes, hepatocytes, and kidney cortex caused by cholesterol
rich diet in rats and subsequently examined the role of vitamin E administration
on the cholesterol-induced effects in these tissues. Administration of
hypercholesterolemic diet to the rats for 4.5 months, significantly decreased
membrane Na(+)-K(+)-ATPase and Ca+2-ATPase activities in comparison to the
controls in all tissues studied. Vitamin E supplementation to the
hypercholesterolemic rats led to a recovery in membrane ATPase activities. In
conclusion, vitamin E supplementation to the rats provided protection against
hypercholesterolemic diet-induced impairment of membrane-bound ATPases.
PMID- 10683755
TI - Precaecal digestibility of niacin and pantothenic acid from different foods.
AB - This study was conducted to investigate the apparent precaecal digestibilities of
niacin and pantothenic acid from human nutrient related foods including wheat,
coarse whole-meal bread, boiled potatoes and boiled pork and beef. Therefore,
pigs were subjected to an end-to-end ileo-rectal anastomosis, so digesta passed
straight from ileum to rectum, eliminating endogenous vitamin synthesis. Excreted
chyme was collected over 5-days periods, and concentrations of niacin, and
pantothenic acid in the food and chyme samples were determined microbiologically.
The intestinal bioavailability of niacin and pantothenic acid was affected
differently by the food administered. The digestibility values of niacin deriving
from the wheat-, potato- and the meat-based meals ranged from 59 to 69%.
Wholemeal bread exerted a nutritionally important negative effect on the apparent
intestinal availability of dietary niacin relative to the other foods, which
averaged by 40%. Food-related differences of the pantothenic acid digestibility
values were greater than that observed with niacin. The digestibility values of
pantothenic acid from wheat, potatoes and the meat meals ranged between 65 and
81% and were of the order wheat diet > pork diet > potato diet > beef diet,
although differences were not statistically significant. The digestibility of
pantothenic acid from the coarse wholemeal bread diet was lower than 30%.
PMID- 10683756
TI - Lack of effect of dietary chromium supplementation on glucose tolerance, plasma
insulin and lipoprotein levels in patients with type 2 diabetes.
AB - Chromium is essential for the regulation of insulin action, thereby influencing
carbohydrate and lipid metabolism. An uncontrolled pilot study was designed to
measure the habitual daily intake of chromium in a group of healthy individuals
with type 2 diabetes and to monitor the effect of daily supplementation with high
chromium yeast on glucose tolerance, plasma insulin and lipoproteins. Twelve free
living adults with type 2 diabetes underwent a glucose tolerance test (GTT) on
recruitment, at 4 weeks (after a 7-d duplicate diet collection) and at 12 weeks
(following 8 weeks daily supplementation with 100 micrograms of chromium). Urine
samples were collected on the day before and the day of each GTT. Blood samples
were taken at half hourly intervals for 3 hours during the GTT and the plasma
glucose, cholesterol, triglyceride, HDL, LDL and insulin concentration measured.
The chromium content of diets and urine samples was determined. Fasting glucose
concentrations and glucose area under the curve profiles did not alter
significantly post supplementation with the chromium rich yeast. No significant
changes in insulin and lipoprotein concentrations were observed. The results of
this study do not support the hypothesis that individuals with type 2 diabetes
benefit from yeast-based chromium supplements (100 micrograms/day).
PMID- 10683757
TI - Effects of capsaicin on biliary free fatty acids in rats.
AB - The effects of capsaicin, a major pungent agent of capsicum fruits, on biliary
free fatty acids (FFAs) were studied in male rats. Animals were dosed 100 mg/kg
capsaicin after the administration of olive oil, and the bile was obtained for 6
hours continuously after dosing with capsaicin for analysis of FFAs using HPLC
methods. Capsaicin significantly decreased the total biliary FFA concentration in
the animals which had been previously increased by the administration of olive
oil. The main FFAs in the bile of control rats are lauric and palmitic acids,
followed by linoleic, oleic, stearic and palmitoleic acids. Capsaicin alone
decreased the values of these main FFAs. While lauric, palmitic, linoleic,
stearic and arachidonic acids were increased significantly by the treatment with
olive oil, elevation of these FFAs was inhibited by the treatment with capsaicin.
PMID- 10683758
TI - Dietary polyunsaturated fatty acids and plasma butyrylcholinesterase activity in
piglets.
AB - Diets containing different ratios of n-3:n-6 polyunsaturated fatty acids, were
fed to piglets for a period of 10 days. Diets with n-3:n-6 ratios of 0.2 and 0.3
decreased the group mean activity of plasma butyrylcholinesterase when compared
with a diet with a ratio of 0.1.
PMID- 10683759
TI - Standards for the Ph.D. degree in the molecular biosciences. Recommendations of
the Committee on Education of the International Union of Biochemistry and
Molecular Biology.
PMID- 10683760
TI - How standards for the Ph.D. degree in the molecular biosciences came about.
PMID- 10683761
TI - Hypothetical double-helical poly(A) formation in a cell and its possible
biological significance.
AB - Arguments are presented in favor of capability of poly(A)-tracts of cellular RNA
to form double helices in vivo. It is suggested that formation of the double
helix in the mRNA poly(A) tall provides the basis for such processes as
polyadenylation termination, PAB I synthesis autoregulation, and stabilization of
ARE-containing mRNA by ELAV-like proteins.
PMID- 10683762
TI - ERK/MAPK pathway is required for changes of cyclin D1 and B1 during phorbol 12
myristate 13-acetate-induced differentiation of K562 cells.
AB - Phorbol 12-myristate 13-acetate (PMA)-induced differentiation of human
erythroleukemic K562 cells is characterized by growth arrest, morphological
change, and expression of megakaryocyte-specific proteins. We examined the
possible involvement of cell cycle regulators with PMA-induced growth arrest and
megakaryocytic differentiation of K562 cells. The concentrations of cyclin D1 and
p21Waf1/Cip1 were dramatically increased, whereas those of cyclin B1 and cdc2
were decreased, by PMA treatment. The concentrations of most cyclin-dependent
kinases (Cdk2, Cdk4, and Cdk6), however, were unchanged by PMA treatment.
PD98059, a specific inhibitor of MEK1, partially prevented the increase in cyclin
D1 caused by PMA and fully reversed the down-regulation of cyclin B1 protein seen
in response to PMA treatment. Thus, it is demonstrated here that the PMA-mediated
changes of cyclin D1 and B1 are the result of a persistent increase in
extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK)
activity.
PMID- 10683763
TI - 5' to 3' single strand DNA exonuclease activity in a preparation of human Ku
protein.
AB - We describe a novel 5' to 3' single-strand exonuclease activity exhibited by a Ku
preparation purified from a human cell line. The enzyme removes 5' single-strand
extensions from duplex DNA molecules. The exonuclease and helicase activities
respond reciprocally to changes in ATP concentrations: Nuclease activity is
inhibited at the ATP concentrations that are optimal for the helicase. The
exonuclease activity does not require divalent cations. The potential
implications of the exonuclease activity findings for repair of double-strand
breaks and recombination processes are discussed.
PMID- 10683764
TI - Signature sequences for the galectin-4 subfamily.
AB - Galectins are a distinct family of animal lectins that have a cation-independent
affinity for beta-galactoside sugars and share characteristic amino acid
sequences. The cDNA encoding rabbit bladder galectin-4 has been cloned and
sequenced (GenBank accession no. AF091738). The deduced 328 amino acid sequence
predicts a multidomain structure consisting of an N-terminal peptide (19
residues) and two carbohydrate recognition domains (130 residues each) connected
by a linker region (49 residues). Comparison of rabbit galectin-4 with related
proteins reveals that two peptide motifs, M-A-F/Y-V-P-A-P-G-Y-Q-P-T-Y-N-P-T-L-P-Y
in the N terminus and A-F-H-F-N-P-R-F-D-G-W-D-K-V-V-F in the first carbohydrate
recognition domain are highly conserved in human, pig, rat, and mouse galectin-4
as well as in mouse galectin-6. The two peptide motifs are proposed here as the
signature sequences to identify new members of the galectin-4 subfamily.
PMID- 10683765
TI - Variation of hepatic methotrexate 7-hydroxylase activity in animals and humans.
AB - This study deals with individual and species variations in the converting
activity of methotrexate (MTX) to 7-hydroxymethotrexate in animals and humans.
When MTX 7-hydroxylase was assayed in six human liver cytosols, a 48-fold range
of intersubject variation of the activity was observed. The variations were
correlated to the concentrations of aldehyde oxidase activity in human subjects
assayed with benzaldehyde as a substrate. Species differences of liver MTX 7
hydroxylase activity were also observed. The activity was highest in rabbits,
followed by rats, hamsters, and monkeys but was undetectable in dogs. Strain
differences of MTX 7-hydroxylase activity based on aldehyde oxidase activity were
also observed in rats and mice. The results suggest that aldehyde oxidase
functions as MTX 7-hydroxylase in livers of animals and humans, and the observed
differences of MTX 7-hydroxylase activity are due to variations in the amount of
aldehyde oxidase present.
PMID- 10683766
TI - Single-stranded oligodeoxyribonucleotides are substrates of Fpg protein from
Escherichia coli.
AB - The interaction of Escherichia coli Fpg protein, which catalyzes excision of
several damaged purine bases including 8-oxoguanine (oxoG) from DNA with a set of
single- (ss) and double-stranded (ds) 23-mer oligodeoxyribonucleotides (ODNs)
containing 8-oxoguanine(s) at various positions, has been investigated. The
affinities of different ss ODNs (KM = 0.55-1.3 microM) were shown to be 12-170
times less than those for corresponding ds ODNs (KM = 6-60 nM). Depending on the
position of the oxoG within the ODNs, relative initial rates of conversion of ss
substrates may be less than, comparable, or greater than those for ds ODNs. The
enzyme can remove 5'-terminal oxoG from ODNs only if the 5'-end is
phosphorylated. Fpg does not release oxoG residues from the ultimate and
penultimate 3'-terminal positions. Duplexes containing two adjacent oxoG are poor
substrates for the glycosylase.
PMID- 10683767
TI - Fine structure of the human translocation protein 1 (HTP1/TLOC1) gene.
AB - We characterized the genomic region corresponding to the human translocation
protein 1 (HTP1/TLOC1) cDNA previously reported. An experiment using rapid
amplification of cDNA ends revealed that the transcription initiation site was at
-12 bp upstream from the translation initiation codon ATG. Using direct
sequencing PCR, we determined precise intron/exon boundaries and intron-exon
composition of the gene. The gene region spanned approximately 28 kb and was
composed of eight exons and seven introns. The lengths of exons and introns range
from 48 to > 1707 bp and from 0.25 to 8.2 kb, respectively. The translation
initiation codon and the termination codon were located in exons 1 and 8,
respectively. The nucleotide sequences of the introns were also determined in the
region around the intron/exon boundaries for 63 to 442 bp. All of the sequences
around the intron/exon boundaries were consistent with the 5' and 3' consensus
sequences for splice junctions of transcribed genes. Putative lariat sequences
were identified between -28 and -64 nucleotides from the 3' splice junction for
all seven introns. DNA walking experiments revealed a promoter region of 600 bp.
The promoter region did not contain an apparent TATA box or a CAT box but did
contain Evi-1, GATA, v-Myb, MZF1, and AP-1 binding sites--factors known as
regulatory factors on expression of the gene in blood cells. Therefore, this gene
may be one such gene.
PMID- 10683768
TI - Effects of chlorophyll availability on phycobilisomes in Synechocystis sp. PCC
6803.
AB - Inactivation of the chlL gene in Synechocystis sp. PCC 6803 resulted in
negligible chlorophyll content when the mutant was grown in darkness. Upon
phycocyanin excitation at 580 nm, the 77K fluorescence spectrum of dark-grown
cells showed three peaks at 648 nm, 665 nm, and 685 nm, this last being the
largest. This reflects the functional presence of major components of
phycobilisomes, including phycocyanin, allophycocyanin, and the terminal emitter,
and efficient energy transfer between these components. As expected, no
fluorescence emission peaks corresponding to chlorophyll in the photosystems were
observed. Intact phycobilisomes could be isolated from the dark-grown chlL
deletion mutant. However, the phycobilisomes had a lower efficiency of energy
transfer than did those isolated from the light-grown mutant, probably because of
a decreased phycobilisome stability in the absence of chlorophyll. Exposing the
dark-grown chlL-deletion mutant to light triggered the biosynthesis of
chlorophyll. For the first 6 h in the light, upon phycocyanin excitation at 580
nm, the 77K fluorescence emission spectrum of greening cells was identical to
that of dark-grown cells that lacked significant amounts of chlorophyll. With
increased chlorophyll synthesis, gradual energy transfer from phycobilisomes to
the two photosystems can be demonstrated.
PMID- 10683769
TI - Mechanism of oxidative damage to fish red blood cells by ozone.
AB - The present study was conducted to elucidate the adverse effects of ozone
exposure on rainbow trout (Oncorhynchus mykiss) red blood cells (RBCs). We
evaluated whether hemoglobin (Hb) or Hb-derived free iron could participate in
the RBC damage using an in vitro ozone exposure system. Ozone exposure induced
hemolysis, formation of methemoglobin, and RBC membrane lipid peroxidation. This
RBC damage was not suppressed by the addition of a specific iron chelator
(deferoxamine mesilate) to the medium but was suppressed by carbon monoxide (CO)
treatment before ozone exposure. Generation of hydrogen peroxide (H2O2) in RBC
was observed upon ozone exposure but was significantly suppressed by CO treatment
before ozone exposure. Thus the Hb status (i.e., Hb redox condition) and H2O2
generation in RBC should play important roles in mediating RBC damage by ozone
exposure. In other words, neither ozone nor its derivative directly attacked from
the outside of the cell, but ozone that penetrated through the membrane derived
the reactive oxygen species from Hb inside of the cell.
PMID- 10683770
TI - Stability of alkyl-dihydroxyacetonephosphate synthase in human control and
peroxisomal disorder fibroblasts.
AB - Alkyl-dihydroxyacetonephosphate synthase (alkyl-DHAP synthase) is a peroxisomal
enzyme that plays a key role in ether phospholipid biosynthesis. To determine the
turnover of alkyl-DHAP synthase in several peroxisomal disorders, pulse-chase
experiments were performed. In control fibroblasts, mature alkyl-DHAP synthase
displayed a half-life of 23 +/- 12 h. In Zellweger syndrome and rhizomelic
chondrodysplasia punctata fibroblast cell lines, in which alkyl-DHAP synthase
cannot be imported into peroxisomes, the enzyme was mainly detected in its
precursor form. This precursor form showed a much shorter half-life, 5 +/- 2 h.
In contrast, when the precursor protein accumulated inside the peroxisome of a
particular neonatal adrenoleukodystrophy cell line in which processing does not
take place, a half-life of 18 +/- 8 h, resembling that of the mature protein in
controls, was observed. In a cell line from a patient with a single deficiency in
the activity of alkyl-DHAP synthase, the mature form was detected and its
radioactivity decreased with a half-life of 16 +/- 7 h. Collectively, these
results provide an explanation for the instability of alkyl-DHAP synthase outside
its target organelle. Additionally, they indicate that both the precursor and
mature form of alkyl-DHAP synthase exhibit considerable intraperoxisomal
turnover.
PMID- 10683771
TI - Incision size and intraocular lens implantation.
PMID- 10683772
TI - Supernormal vision, hypervision, and customized corneal ablation.
PMID- 10683773
TI - Interface Elschnig pearl formation with piggyback implantation.
PMID- 10683774
TI - IOL registry and errors in A-scan.
PMID- 10683775
TI - Drift index to explain patient complaints after PRK.
PMID- 10683776
TI - Comments on the combined procedure.
PMID- 10683777
TI - Medical control of IOP after cataract surgery.
PMID- 10683778
TI - Preventing ocular damage from a cannula.
PMID- 10683779
TI - Lidocaine gel for topical anesthesia.
PMID- 10683780
TI - Avoiding conjunctival necrosis after periocular depot corticosteroid injection.
PMID- 10683781
TI - Simple nucleus cracking technique.
PMID- 10683782
TI - Consultation section. Refractive surgical problem.
PMID- 10683783
TI - Closed chamber iridodialysis repair using a needle with a distal hole.
AB - We describe a closed-system technique of iridodialysis repair using a 22.0 mm,
plastic handled, 27 gauge straight needle with a hole 1.0 mm proximal to the tip.
The distal hole is suitable for passage of 9-0 or 10-0 mm polypropylene or nylon
sutures. The technique was effective in 8 patients with traumatic iridodialysis
in the upper and inferior temporal quadrants.
PMID- 10683784
TI - In situ tumbling of the AcrySof intraocular lens.
AB - The small incision through which foldable acrylic intraocular lenses (IOLs) are
implanted does not allow easy explantation of the lens in the event of
intraoperative complications. Reversal of the IOL optic during insertion,
although rare, can predispose to postoperative complications such as pupillary
capture of the IOL, capsule bag distension syndrome, and refractive problems.
Explanting the IOL can damage it, the cataract wound, or both. We describe a
technique of in situ tumbling of the AcrySof IOL to correct reversed-optic
implantation that preserves the integrity of the IOL and anterior segment
structures.
PMID- 10683785
TI - Surgical prevention of posterior capsule opacification. Part 1: Progress in
eliminating this complication of cataract surgery.
AB - PURPOSE: To evaluate over almost 2 decades the success of a component of cataract
surgery that represents a critical step in reducing the incidence of posterior
capsule opacification (PCO); namely, the efficacy of cortical cleanup. SETTING:
Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute,
Department of Ophthalmology, Medical University of South Carolina, Charleston,
South Carolina, USA. METHODS: Accessioned from the early 1980s to 1997, 3320 eyes
obtained postmortem with posterior chamber intraocular lenses were analyzed with
respect to formation of a postoperative Soemmering's ring. This anatomic lesion,
the precursor of clinical PCO, represents an important and measurable indication
of the quality of cortical cleanup. Its formation was documented using Miyake
Apple posterior photographic analysis. RESULTS: The quality and thoroughness of
cortical cleanup and overall effectiveness in eliminating retained and/or
regenerating cortical cells, as measured by scoring of Soemmering's rings, showed
virtually no net change since the early 1980s. The intensity of Soemmering's ring
was higher in the most recent specimens than in those in the early 1980s.
CONCLUSION: The results indicate that renewed attention to cortical cleanup in
cataract surgery is warranted for significant reduction in incidence or the
elimination of PCO. More attention to the hydrodissection (cortical cleaving
hydrodissection) step of the procedure is likely a practical, immediately
implementable, and inexpensive remedy.
PMID- 10683786
TI - Surgical prevention of posterior capsule opacification. Part 2: Enhancement of
cortical cleanup by focusing on hydrodissection.
AB - PURPOSE: To experimentally analyze the role and efficacy of hydrodissection in
achieving maximal cortical cleanup. SETTING: Center for Research on Ocular
Therapeutics and Biodevices, Storm Eye Institute, Department of Ophthalmology,
Medical University of South Carolina, Charleston, South Carolina, USA. METHODS:
Phacoemulsification and irrigation/aspiration were performed in 10 pairs of human
eyes (20 eyes) obtained postmortem. Ten eyes had previous hydrodissection and 10
eyes, no hydrodissection. The time (seconds) required for complete lens substance
removal in each procedure was measured. In addition, a qualitative evaluation of
difficulty of surgery was noted. RESULTS: Phacoemulsification required 28.6% less
time in eyes with previous hydrodissection than in those without.
Irrigation/aspiration time was reduced by 50.9% when hydrodissection was
performed. The total time of each procedure required for complete evacuation of
the capsular bag was reduced by an average of 37.7% in eyes with hydrodissection.
Furthermore, qualitatively the procedure was far easier, less stressful, and
caused less posterior capsule stress or rupture when copious hydrodissection was
performed. CONCLUSIONS: Hydrodissection enhances the general safety and
efficiency of cortical cleanup, especially at 12 o'clock. Hydrodissection is the
best available, practical, immediately implementable, and inexpensive means to
help remove equatorial E-cells and thus alleviate the incidence of posterior
capsule opacification.
PMID- 10683787
TI - Surgical prevention of posterior capsule opacification. Part 3: Intraocular lens
optic barrier effect as a second line of defense.
AB - PURPOSE: To emphasize an important aspect of preventing posterior capsule
opacification (PCO), the barrier effect established by the optic of a posterior
chamber intraocular lens (PC IOL), and present a new classification regarding
capsular bag status after extra-capsular cataract extraction, including
phacoemulsification. SETTING: Center for Research on Ocular Therapeutics and
Biodevices, Storm Eye Institute, Medical University of South Carolina,
Charleston, South Carolina, USA. METHODS: This analysis included 150 consecutive
eyes obtained postmortem with United States-manufactured PC IOLs including (1)
poly(methyl methacrylate), (2) silicone, and (3) hydrophobic acrylic designs that
were accessioned in the Center from September 1995 to January 1, 1998. Gross
photographs from behind (Miyake-Apple views) were taken and serial histologic
sections prepared. RESULTS: Microscopic analysis of the 150 eyes showed that the
morphologic appearance of the capsular bag could be grouped into 2 categories:
(1) those with little or no evidence of retained cortical material and cells, and
(2) those with retained cortical material and cells in which a Soemmering's ring
formed. With the latter, when a distinct barricade to cellular migration created
by the IOL optic was noted, 2 discrete configurations occurred, depending on the
different geometries of the optic components. With a classic biconvex optic with
a curved and tapered edge, in many instances some ingrowth of cells proceeded
posteriorly around the edge of the IOL optic in the direction of the central
axis. With a lens optic that had a squared, truncated, and relatively thick edge,
there was often abrupt termination of cells at the peripheral edge of the optic.
The posterior capsule subtending the entire optic zone was therefore relatively
or totally cell free. CONCLUSIONS: The barrier effect of the IOL optic appears to
be of critical importance in retarding ingrowth of cells, functioning as a second
line of defense when cortical cleanup is incomplete. Analysis of PC IOLs obtained
postmortem showed that a square, truncated optic edge seemed to provide the
maximum impediment to cell growth behind the IOL optic.
PMID- 10683788
TI - Corneal ablation patterns to correct for spherical aberration in photorefractive
keratectomy.
AB - PURPOSE: To determine the spherical aberration introduced by photorefractive
keratectomy (PRK) and customize ablation patterns to compensate for this
aberration and improve post-PRK visual performance. SETTING: Department of
Ophthalmology, University of Arizona, Tucson, Arizona, USA. METHODS: Presurgical
and postsurgical corneal topography of 16 patients who had PRK with the Summit
OmniMed laser were obtained. The data were applied to a schematic eye model, and
exact ray tracing was used to determine the introduction of spherical aberration
from the procedure. Optimization routines were used to determine the ideal
ablation pattern. RESULTS: The magnitude of the spherical aberration introduced
into the eyes after PRK increased with the level of attempted correction. The
theoretical ideal ablation pattern requires additional flattening of the ablation
periphery to avoid the introduction of spherical aberration. CONCLUSIONS: Current
PRK ablations introduce spherical aberration into the eye. Modifying the existing
ablation algorithms to compensate for spherical aberration may boost
postoperative visual performance.
PMID- 10683789
TI - Keratoconus evaluation using the Orbscan Topography System.
AB - PURPOSE: To evaluate corneal topography in a series of keratoconus patients using
the Orbscan Topography System. SETTING: Department of Ophthalmology, Ruprecht
Karls-University of Heidelberg, Heidelberg, Germany. METHODS: Seventy-one eyes of
38 patients with keratoconus were evaluated. Quantitative topographic parameters
were analyzed with special reference to the central point of the cornea, the apex
(the point with maximum reading on the anterior elevation best-fit sphere map),
and the thinnest point. Evaluation included location, elevation (compared to a
best-fit sphere), pachymetry, tangential curvature, and composite curvature. The
mirror-image symmetry between the right and left eyes of a patient was also
investigated. RESULTS: Mean patient age was 31.2 years +/- 12.2 (SD). Thirty
three patients (86.8%) had bilateral keratoconus and 5 (13.2%), unilateral
keratoconus. Most cones (68/71) were located in the inferior temporal quadrant; 3
were above the horizontal meridian. Mean distance between the apex and the
thinnest point was 0.917 +/- 0.729 mm (P < .001). The correlations between apex
elevation and apex composite curvature and apex tangential curvature were high (r
= 0.94 and r = 0.91, respectively; P < .001). In right and left eyes, there was a
correlation between the apex and the thinnest point semi-meridians (r = 0.47 and
r = 0.65, respectively; P < .05) but not between the radii of the apex and the
thinnest point (r = 0.21 and r = 0.24, respectively). CONCLUSIONS: The Orbscan
system can provide useful and accurate information in defining the morphology of
keratoconus and detecting subtle topographic changes present in early
keratoconus. It may also improve the results of contact lens fitting and surgical
management.
PMID- 10683790
TI - Comprehensive method of analyzing the results of photoastigmatic refractive
keratectomy for the treatment of post-cataract myopic anisometropia.
AB - PURPOSE: To assess the efficacy, stability, and safety of photoastigmatic
refractive keratectomy (PARK) in treating post-cataract myopic anisometropia to
restore binocularity and to describe a comprehensive method for analyzing the
results of refractive surgery. SETTING: St. Paul's Eye Center, Royal Liverpool
Hospital, Liverpool, United Kingdom. METHODS: Nineteen patients (20 eyes) with
post-cataract myopic anisometropia were treated with PARK using a VISX Twenty
Twenty laser and followed for 12 months. Cataract surgery had been performed
between 10 and 144 months (mean 43.4 months) previously. A comprehensive method
based on Long's matrix formalism and the vech operator of Harris, in addition to
the nearest equivalent sphere and cylinder, was used to analyze the refractive
data. RESULTS: The mean preoperative refraction in the post-cataract eyes was
4.79 +1.17 x 0.2 and in the fellow eyes, +0.02 +0.31 x 166. Twelve months after
PARK, the postoperative refraction in the post-cataract eyes was -0.90 +0.65 x 2,
a significant reduction (P = .15). This postoperative refraction was not
significantly different from that in the fellow eye (P = .93). The pretreatment
mean uncorrected visual acuity was 0.12. It improved to 0.41 at 12 months, at
which time 52% of eyes achieved a visual acuity of 0.5 or better without
correction. All patients regained binocularity. At 12 months, 2 eyes (11%) showed
clinically unacceptable regression; 1 eye with grade 2 haze lost 1 line of
corrected visual acuity. CONCLUSIONS: Photoastigmatic refractive keratectomy
reduced post-cataract myopic anisometropia, allowing restoration of binocularity
in all patients. Overall, the results in this elderly population with previous
ocular surgery, posterior capsule thickening, and macular degeneration are not as
satisfactory as those obtained from similar treatment of physiological myopia.
Stability and postoperative complications are acceptable.
PMID- 10683791
TI - Incision width after phacoemulsification with foldable intraocular lens
implantation.
AB - PURPOSE: To determine the incision size after insertion of foldable intraocular
lenses (IOLs) using both a forceps and injectors. SETTING: Intermountain Ocular
Research Center, Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
METHODS: One hundred patients had phacoemulsification through a clear corneal
wound. The incision width was measured before and after IOL implantation. A 3
piece silicone IOL and a 3-piece acrylic IOL (both with an optic diameter of 5.5
mm) were inserted using a forceps. A plate-haptic silicone lens and a 3-piece
silicone lens with a 6.0 mm diameter optic were inserted using an injector.
RESULTS: The wound size in the group with the 3-piece silicone lens inserted with
a forceps enlarged 4.4% (3.23 to 3.38 mm) in the low-power IOL group (15.0 to
20.0 diopters [D]) and 6.2% (3.24 to 3.44 mm) in the high-power IOL group (20.5
to 25.0 D). Similarly, the acrylic IOL wound enlarged 5% (3.21 to 3.37 mm) in the
low-power IOL group and 6% (3.25 to 3.44 mm) in the high-power IOL group when a
forceps was used. The 3-piece silicone and plate silicone lenses inserted using
an injector enlarged the wound 3.2% and 3.3% (3.02 to 3.11 mm and 3.05 to 3.15
mm), respectively. There was no difference in the wound size with higher IOL
powers in eyes with injected lenses. CONCLUSIONS: Clear corneal incisions enlarge
after insertion of foldable IOLs in a predictable manner, with a forceps-inserted
IOL enlarging the wound diameter more than lenses inserted with an injector. The
forceps-inserted lens group also showed a difference in wound size related to IOL
power.
PMID- 10683792
TI - Transconjunctival corneoscleral tunnel "blue line" cataract incision.
AB - PURPOSE: To report the technique and astigmatic results of the blue line cataract
incision. SETTING: The Buzzard Eye Institute, Las Vegas, Nevada, USA. METHODS:
This prospective study included 411 eyes of 271 patients who had cataract
extraction by phacoemulsification with a self-sealing 3.0 mm blue line cataract
incision. The blue line incision is performed with a diamond knife
transconjunctively, 2.0 mm behind the surgical limbus. RESULTS: Mean patient age
was 68 years (range 40 to 94 years) and mean preoperative astigmatism, 0.96
diopter (D) +/- 0.78 (SD). Uncorrected visual acuity at 1 day was 20/40 or better
in 47% of patients. Mean spherical equivalent was -0.57 +/- 0.78 D at 6 months.
Mean postoperative astigmatism measured with a subtraction method was 1.00 +/-
0.84 D at 6 months. Vector analysis showed an induced astigmatism of -0.47 +/-
1.00 D at 1 month, -0.58 +/- 0.81 D at 3 months, and -0.57 +/- 0.99 D at 6
months. No complications such as wound leakage or hyphema occurred. CONCLUSION:
The blue line incision combines the efficiency of the clear corneal with the
safety of the scleral tunnel cataract incision and appears to be relatively
astigmatically neutral.
PMID- 10683793
TI - Five year study of astigmatic stability after cataract surgery with intraocular
lens implantation: comparison of wound sizes.
AB - PURPOSE: To assess the long-term stability of cataract wounds of various lengths.
SETTING: Private practice. METHODS: This retrospective study comprised 5 groups
of consecutive cataract surgery cases and 1 control group with similar mean ages
and wound lengths of 10.0, 6.0, 4.0, 2.0, and 0 (control) mm. Except for the 4.0
mm cases, follow-up was 5 years, with few patients lost during that time. Cases
within each group had the same wound position, configuration, and suturing.
Refractive data, controlled by keratometry, were collected and analyzed
preoperatively and 1 day, 1 and 6 weeks, 3 and 6 months, and 1, 2, 3, 4, and 5
years postoperatively. No sutures were cut. RESULTS: With long-term follow-up,
there was a progressive against-the-rule shift in astigmatism. Smaller wounds
showed less immediate induced astigmatism. However, except for the unsutured 2.0
mm iridectomy wounds and the control group, all shifted similarly. Data were not
available for the 4.0 mm wounds beyond 1 year. CONCLUSION: Wounds were not
necessarily "stable" at 6 months. Larger wounds continued to shift years after
surgery. Smaller wounds have significant postoperative advantages, but absolute
long-term refractive stability may not be one.
PMID- 10683794
TI - Combined phacoemulsification, vitrectomy, foreign-body extraction, and
intraocular lens implantation.
AB - PURPOSE: To assess the outcome of simultaneous phacoemulsification, pars plana
vitrectomy, intraocular foreign-body extraction, and intraocular lens (IOL)
implantation. SETTING: SSK Ankara Eye Hospital, Department of Vitreoretinal
Surgery, Ankara, Turkey. METHODS: Seventeen patients with corneal perforation,
intraocular foreign body, vitreous hemorrhage, and lens opacity had simultaneous
clear corneal phacoemulsification, pars plana vitrectomy, intraocular foreign
body extraction, and IOL implantation. RESULTS: Postoperative complications
included massive retinal fibrosis in 2 patients, retinal detachment in 1, and
cilioretinal artery occlusion in 1. At a mean follow-up of 15.2 months, best
corrected visual acuity improved in the remaining 13 eyes (76%). The IOL was
stable in all cases. CONCLUSION: Combined phacoemulsification with IOL
implantation and vitreoretinal surgery was safe in selected cases of penetrating
ocular trauma resulting from an intraocular foreign body.
PMID- 10683795
TI - Perception of Purkinje vessel shadows and foveal granular pattern as a measure of
potential visual acuity.
AB - PURPOSE: To compare perception of 2 entoptic phenomena, the Purkinje vessel
shadows and the foveal granular pattern, as measures of retinal visual acuity
using a transscleral illumination technique that bypasses the anterior segment.
SETTING: Retinal Vascular Center and General Eye Clinic, Wilmer Ophthalmological
Institute, Johns Hopkins Hospital, Baltimore, Maryland, USA. METHODS: Both eyes
of 85 patients with clear ocular media, many with retinal disease, were tested
for perception of these entoptic phenomena. Also, retinal visual acuity was
measured with a Potential Acuity Meter through the current refractive correction.
RESULTS: Of 114 eyes with retinal acuity of 20/40 or better, 99% perceived the
Purkinje vessel shadows and 86% perceived the foveal granular pattern. Of 45 eyes
with retinal acuity of 20/80 or worse, 73% perceived the Purkinje vessel shadows
and 4% perceived the foveal granular pattern. CONCLUSION: Perception of the
Purkinje vessel shadows does not distinguish between good and poor retinal
acuity, whereas nonperception of the vessel shadows strongly suggests poor
acuity. Perception of the foveal granular pattern, on the other hand, provides a
positive indication of good retinal acuity and will likely prove to be predictive
of good vision after removal of significant media opacity.
PMID- 10683796
TI - Long-term results of out-of-the-bag intraocular lens implantation.
AB - PURPOSE: To evaluate long-term results of out-of-the-bag intraocular lens (IOL)
implantation. SETTING: Department of Ophthalmology, Tenri Yorozu Hospital, Nara,
Japan. METHODS: This study comprised 22 patients, 13 women and 9 men, who had
cataract surgery by phacoemulsification and out-of-the-bag IOL implantation
because of a posterior lens capsule rupture. Sixteen patients had in-the-bag IOL
implantation in the fellow eye, and these eyes were used as a control group. The
IOL's position was determined by ultrasound biomicroscopy (UBM). Anterior chamber
flare counts were measured by a laser flare meter. The corneal endothelium was
observed by specular microscopy. RESULTS: Mean follow-up after cataract surgery
was 35 months +/- 22 (SD). The UBM revealed that in the 19 eyes with sulcus-to
sulcus IOL fixation, the optics touched the iris. In 3 eyes, 1 haptic was fixated
at the sulcus and the other at the ciliary body. In 2 of these eyes, the optics
did not touch the iris. Anterior chamber flare counts in eyes with sulcus-to
sulcus IOL fixation were significantly higher than in eyes with in-the-bag or
sulcus-to-ciliary-body fixation (P < .05). There were no statistical differences
in corneal endothelial cell counts based on haptic placement. CONCLUSION: Rubbing
between the IOL optic and iris seems to contribute to the high flare counts in
eyes with a sulcus-to-sulcus IOL fixation. A larger haptic angle may be needed to
prevent contact between the iris and IOL optic in such cases.
PMID- 10683797
TI - Intraocular pressure after small incision cataract surgery with Healon5 and
Viscoat.
AB - PURPOSE: To evaluate the effect of Healon5 (sodium hyaluronate) and Viscoat
(sodium chondroitin sulfate-sodium hyaluronate) on intraocular pressure (IOP)
after bilateral small incision cataract surgery. SETTING: Department of
Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective
randomized study comprised 70 eyes of 35 consecutive patients with age-related
cataract in both eyes scheduled for bilateral small incision cataract surgery.
The patients were randomly assigned to receive Healon5 or Viscoat during cataract
surgery in the first eye. The second eye received the other viscoelastic
substance. Cataract surgery was performed in an identical fashion in both eyes,
with a temporal 3.5 mm sutureless posterior limbal incision, phacoemulsification,
and implantation of a foldable silicone intraocular lens. The IOP was measured
preoperatively and 6 hours, 20 to 24 hours, and 1 week postoperatively. RESULTS:
At 6 hours after surgery, the mean IOP increased by 5.2 mm Hg +/- 5.3 (SD) in the
Healon5 group (P < .0001) and by 10.1 +/- 8.7 mm Hg in the Viscoat group (P <
.0001). The increase was significantly higher in the Viscoat group than in the
Healon5 group (P = .0016). Intraocular pressure spikes of 30 mm Hg or more
occurred in 2 eyes in the Healon5 group and in 10 eyes in the Viscoat group (P =
.0112). Twenty to 24 hours and 1 week postoperatively, the mean IOP in the 2
groups was not statistically different. CONCLUSIONS: Viscoat caused a
significantly higher IOP increase and significantly more IOP spikes than Healon5
in the early period after small incision cataract surgery.
PMID- 10683798
TI - Effect of Healon and Viscoat on outflow facility in human cadaver eyes.
AB - PURPOSE: To compare the acute effects of Healon (sodium hyaluronate) and Viscoat
(sodium chondroitin sulfate-sodium hyaluronate) on outflow facility in human
cadaver eyes and determine which viscoelastic agent is least likely to cause an
intraocular pressure (IOP) spike after cataract surgery. SETTING: The Glaucoma
Research Lab, University of Toronto, Ontario, Canada. METHODS: In this
prospective paired study, 15 pairs of human cadaver eyes were used. Following the
construction of a 3.0 mm scleral tunnel, 0.25 cc of Healon was injected into the
anterior chamber of 1 eye and 0.25 cc of Viscoat was injected into the
contralateral eye. The viscoelastic agents were removed from both eyes in a
standardized fashion and the scleral tunnels closed. The eyes were then perfused
at a constant IOP of 8.0 mm Hg, corresponding to 16.0 mm Hg in vivo. Outflow
facility (microL/minute [min]/mm Hg) was recorded every 15 minutes for 24 hours
using standard methods. RESULTS: Outflow facility in the Viscoat-treated eyes
decreased appreciably for the first 3 hours, then recovered somewhat after 12
hours; facility in the Healon-treated eyes showed less of an overall decrease.
Over the 24 hour perfusion period, mean outflow facility was 0.037 microL/min/mm
Hg +/- 0.015 (SD) in the Viscoat-treated eyes and 0.060 +/- 0.012 microL/min/mm
Hg in the Healon-treated eyes. Healon reduced outflow facility significantly less
than Viscoat between 3.25 and 10.50 hours postoperatively (P < .05, 2-tailed t
test). CONCLUSIONS: Healon reduced outflow facility less than Viscoat between
3.25 and 10.50 hours postoperatively.
PMID- 10683799
TI - Ultrasonic transmission in viscoelastic substances.
AB - PURPOSE: To study the propagation of ultrasonic shock waves in viscoelastic
agents and the resulting corneal load. SETTING: University Siegen, Institute for
Mechanics and Control Engineering, Siegen, Germany. METHODS: The anterior chamber
of a manufactured artificial eye was constructed according to anatomic
dimensions. Three openings were drilled--for the phaco tip, for the exchange of a
viscoelastic agent or water, and for the shock-wave sensor. The sensor was fixed
to the area corresponding to the corneal apex. The sensor signal was analyzed
using a direct oscilloscope that measured the amplitude reaching the corneal
apex. Shock-wave propagation in several viscoelastic agents was compared with
that in balanced salt solution. RESULTS: In hydroxypropyl methylcellulose, the
shock wave was amplified or influenced slightly. In hyaluronic-acid preparations,
acoustic dampening occurred. CONCLUSION: Removal of hyaluronic-acid derivatives
prior to phacoemulsification is not necessary.
PMID- 10683800
TI - Detection of integrins in cataract lens epithelial cells.
AB - PURPOSE: To detect the expression of integrin subunits in lens epithelial cells
(LECs) of human cataracts. SETTING: Research Laboratory, International
Intraocular Implant Training Centre, Tianjin Medical University, China. METHODS:
The circular sections of the anterior capsules with attached LECs were obtained
during cataract surgery from 100 patients. The LECs were stained with an avidin
biotin-complex immunohistochemical technique using 5 monoclonal antibodies
specific for alpha subunits 2, 3, 5 and beta subunits 1, 2. RESULTS: All integrin
subunits studied were found to varying degrees in specimens. The positive
percentages were 70%, 65%, 75%, 70%, and 80%, respectively. CONCLUSION: Integrin
subunits were present in LECs of human cataracts. These molecules may serve in
the adhesion of LECs to the lens capsule and play a role in cell-posterior
capsule interaction after cataract surgery.
PMID- 10683801
TI - Corneal ectasia detected after laser in situ keratomileusis for correction of
less than -12 diopters of myopia.
AB - We report 2 cases of corneal ectasia detected after laser in situ keratomileusis
(LASIK) for the correction of less than -12.0 diopters (D) of myopia. Patients
were evaluated before and after LASIK by corneal topography and pachymetry. After
treatment, visual acuity temporarily improved but was followed by visual
impairment, with corneal ectasia detected by topography. There may be a risk of
corneal ectasia after LASIK in cases of myopia of less than -12.0 D. Despite
thelow incidence, we recommend that LASIK be restricted to cases in which more
than half the original corneal thickness and more than 250 microns of the stromal
bed can be preserved. Careful examination, including preoperative serial
topographic evaluation and measurement of posterior stromal thickness, should be
performed to improve the quality and predictability of corneal refractive
surgery.
PMID- 10683802
TI - Phototherapeutic keratectomy of a corneal scar due to presumed infection after
photorefractive keratectomy.
AB - This case involves a 25-year-old patient who suffered from corneal ulceration
several days after photorefractive keratectomy (PRK). A central scar developed,
resulting in discomfort and reduction in visual acuity. Four months later, the
scar was treated by phototherapeutic keratectomy (PTK) (25 microns depth, 5 mm
ablation zone). Some scar tissue was left, but it cleared slowly and steadily
over the next few years. The induced hyperopia decreased from 5.00 to 1.37
diopters spherical equivalent within 28 months postoperatively. Best corrected
visual acuity increased from 20/60 preoperatively to 20/20 at 28 months
postoperatively. Surgeons can encourage patients with postinfectious scars after
PRK to try at least 1 PTK treatment.
PMID- 10683803
TI - Silicone oil removal from a silicone intraocular lens with perfluorohexyloctane.
AB - Silicone oil can be easily dissolved in vivo from silicone intraocular lenses by
perfluorohexyloctane. Using specular microscopy, we examined the corneal
endothelium in a patient with silicone lens implantation immediately after
cataract surgery and 5 weeks postoperatively. There were no signs of acute or
chronic toxicity to the endothelium.
PMID- 10683804
TI - Calcium absorption from the ingestion of coral-derived calcium by humans.
AB - Recent dietary life involves frequent opportunities for the ingestion of
purified, processed food products and preserved foods, and it has been pointed
out that the current dietary mineral intake strongly tends toward nutritional
imbalance. The Ryukyu Islands yield coral which contains calcium and magnesium in
a content ratio of about 2 to 1, with their approximate contents of 20 and 10%,
respectively. In this report, the calcium absorption from the ingestion of
crackers into which the coral powder was incorporated (coral-added crackers) and
that from ingestion of calcium carbonate-added crackers was comparatively
assessed. Twelve healthy adult volunteers (6 men and 6 women) ingested coral
added crackers (calcium content: 525 mg) and calcium carbonate-added crackers
(ditto) once each alternately on a cross-over design with a wash-out period of 3
d between the regimens. The study also included controls receiving neither
cracker. The degree of intestinal absorption of calcium from coral-added crackers
and that from calcium carbonate-added crackers was evaluated in terms of
increment in urinary calcium excretion per dL of glomerular filtrate (GF)
(difference between coral calcium and calcium carbonate) and increase in urinary
calcium excretion per milligram creatinine (difference from control value). The
increment in urinary calcium excretion per dL of GF during the latter half of the
observation period after the ingestion of coral-added crackers was significantly
greater than that during the latter half of the observation period after
ingestion of calcium carbonate-added crackers (p = 0.039, paired t-test). A
significant difference (from control value) in the increase of urinary calcium
excretion per milligram creatinine was also observed (p = 0.0008). The present
data, though from a relatively few study subjects, suggest that the calcium of
coral origin is better absorbed from the intestine than calcium of calcium
carbonate origin on the average.
PMID- 10683805
TI - Foods contributing to absolute intake and variance in intake of selected
vitamins, minerals and dietary fiber in middle-aged Japanese.
AB - Using 351 one-day weighted diet records, we selected foods providing vitamins,
minerals and dietary fiber according to contribution analysis (CA) and multiple
regression analysis (MRA). Vitamin C was supplied by various vegetables and
fruits, and carotene was specifically derived from green-yellow vegetables based
on MRA as well as CA. Vitamin A was provided by green-yellow vegetables, fruits,
chicken egg and milk (whole) according to CA; whereas chicken liver and pork
liver were major sources according to MRA. Vitamin E was mainly of vegetable
origin as determined by CA, and largely of spinach, safflower oil and pumpkin as
determined by MRA. Vitamin D was mainly derived from chicken egg, fish and
mushroom based on CA, and particularly from fish based on MRA. Calcium was
supplied by milk (whole), soy products and chicken egg as determined by CA; while
milk, tofu and various small fishes were the main contributors to variance.
Magnesium was provided by soy products, well-milled rice and spinach according to
both analyses, and iron by chicken egg, spinach and soy products. Zinc was
largely derived from well-milled rice, followed by chicken egg and milk (whole)
as determined by CA, and copper was provided by well-milled rice, soy and wheat
products. Dietary fiber was supplied by vegetable sources, whether water soluble
or insoluble, based on both analytic methods.
PMID- 10683806
TI - Oral health and nutritional status in Egyptian elderly.
AB - A cross-sectional sample of 253 ambulatory elderly Egyptians (99 males and 154
females) of minimal age, 60 y, living in the metropolitan Cairo area was
investigated. Nutritional status assessment was based on body weight, mid-upper
arm circumference and skinfold thickness. Additionally, three nutritional
indices, namely body mass index, index of adiposity and index of muscularity,
were computed. The oral cavity was examined clinically to evaluate the number and
health condition of teeth present. Results showed that the anthropometric
nutritional indicators were higher than expected, however, they decreased by age
in both sexes. In addition, the values of body mass index and index of adiposity
in females were significantly higher than in males, while the reverse was
observed in regards to muscularity index (p < 0.05). The three nutritional
indices in dentate subjects were slightly higher than those in edentulous ones.
Moreover, within the dentate groups there was a tendency for increased values of
these indices by the increasing number of healthy teeth.
PMID- 10683807
TI - Effect of timing of meal intake after squat exercise training on bone formation
in the rat hindlimb.
AB - We hypothesized that bone acquisition was affected by the timing of meal intake
after resistance exercise training. This was based on the following previous
results: 1) Nutrient intake right after exercise resulted in an increase in
muscle mass and a decrease in abdominal fat mass as well as muscle protein
synthesis when compared to the intake of a meal later after the exercise; and 2)
body composition has been proposed to be a good predictor of bone mass. To
substantiate our hypothesis, 20 male rats were assigned to either a group fed a
meal right after squat exercise (R) or a group fed a meal 4 h after the exercise
(L). The 10-wk training program consisted of approximately 70% of one repetition
maximum for each animal, 15 repetitions per set, 10 sets per day, 3 d per week.
As a result, hindlimb muscle mass in the R group was greater (p < 0.05) than that
in the L group and abdominal fat mass was less (p < 0.01) in the R group as
compared to the L group, regardless of there being no significant difference in
body weight between the groups. Bone volume in the tibia (p < 0.01) and femur (p
< 0.05) were both significantly greater in the R group than in the L group. Bone
mineral content index (BMCI) and bone mineral density index (BMDI) in the tibia
of the R group were significantly (p < 0.05) greater than the corresponding
values of the L group. The greater BMCI and BMDI in the tibia were positively and
significantly (p < 0.05) related with hindlimb muscle mass, but not with
abdominal fat mass. There was no significant difference in BMCI and BMDI in the
femur between the groups. These results suggest that the R regimen may contribute
to increased bone acquisition in the tibia as compared to the L regimen, and this
effect is partly due to the enlargement of muscle mass in the R group as compared
to the L group.
PMID- 10683808
TI - Effects of long-term consumption of high doses of fish oil concentrates on
clinical parameters in male and female rats.
AB - Many studies suggest that a diet supplemented with fish oil concentrates (FOCs)
may provide protection against cardiovascular and other diseases. The possible
harmful effects of long-term consumption of high doses of FOCs, however, have not
been adequately investigated. Corn oil, fish oil (MaxEPA) and various mixtures of
the oils were administered by gavage to 120 male and 120 female rats, 5 d/wk for
13 wk at the rate of 5 mL/kg/d. Although MaxEPA had no effect on prothrombin time
or activated partial thromboplastin time, it caused a statistically significant
diminution of the total serum cholesterol level. Correlations between relative
liver and spleen weights and dose levels were positive but a negative correlation
was found between dose levels and serum vitamin E concentration. In female rats,
the negative correlations between dose levels and serum iron and triglyceride
levels were highly significant. The pathology data showed no remarkable lesions
in any of the tissues examined. Results of this study suggest that long-term
consumption of high levels of FOCs in rats may reduce serum cholesterol and
triglycerides and adversely affect serum iron level and relative liver weight in
female rats and relative spleen weights in both sexes.
PMID- 10683809
TI - Effect of a new amino acid solution on nutritional status and nitrogen metabolism
in rats with chronic renal failure undergoing hyperalimentation.
AB - We studied the effects of the new amino acid solution MRX-III on the nutritional
status and nitrogen metabolism of rats with chronic renal failure (CRF) in
comparison with those of a general amino acid solution (MPR-F). The essential
amino acids/non-essential amino acids ratio was 3.21 for MRX-III and 1.09 for MPR
F. Rats with CRF, induced by 7/8 renal ablation, were divided into 6 groups of 8
rats each receiving total parenteral nutrition (TPN) containing MRX-III or MPR-F
at a non-protein calorie/nitrogen ratio (Cal/N) of 300, 600 or 900 for 7 d. The
rats were infused with test solutions containing the same amounts of non-protein
calories. The cumulative nitrogen balance, as a nutritional index, in the MRX-III
group was significantly higher than that in the MPR-F group at the Cal/N of 600
or 900, and the plasma albumin level at the Cal/N of 300. The plasma transferrin
levels at the Cal/N of 900 in the MRX-III groups were significantly higher than
those in the corresponding MPR-F groups. At all Cal/N, the MRX-III groups showed
low levels of blood urea nitrogen and urinary excretion of ammonia and urea
nitrogen as compared with the MPR-F groups at the same Cal/N. The plasma amino
acid concentration profiles in the MRX-III groups after TPN showed greater
similarity to that in the Normal group as compared with the profiles in the
corresponding MPR-F groups. No aggravation of renal failure was observed in any
TPN groups during TPN. These results indicate that, in rats with CRF undergoing
hyperalimentation, the effects of MRX-III on the nutritional status and nitrogen
metabolism are superior to those of the general amino acid solution, MPR-F. It is
suggested that MRX-III could safely provide adequate amounts of nitrogen during
hyperalimentation.
PMID- 10683810
TI - Effect of the fat/carbohydrate ratio in the diet on obesity and oral glucose
tolerance in C57BL/6J mice.
AB - To study whether consumed dietary fat has a linear relationship or a threshold
with glycemic controls, female C57BL/6J mice were fed different levels of a
safflower oil (10, 20, 30, 40, 50, and 60% of total energy) diet ad libitum for
15 wk. Food intake, body weight, parametrial white adipose tissue (WAT) and liver
weight were measured, and oral glucose tolerance tests were conducted. Although
there was no significant difference in average energy intake, graded increments
of safflower oil resulted in graded deterioration of glucose tolerance during 5
and 12-wk feeding, and deterioration of glucose tolerance was more manifested
after 12-wk feeding as compared to 5-wk feeding. After 12-wk feeding, a
significant deterioration of glucose tolerance was observed in diets of more than
40% fat. Graded increments of body weight and WAT weight were observed, and their
weight increases were manifested in diets of more than 30% fat. These data
indicated that the amount of dietary fat had an almost linear relationship with
glucose tolerance, and significant differences were observed in mice fed diets
more of than 40% fat.
PMID- 10683811
TI - Comparison of various phosphate salts as the dietary phosphorus source on
nephrocalcinosis and kidney function in rats.
AB - The effects of various phosphate salts as the dietary phosphorus sources on the
development of nephrocalcinosis and kidney function were examined in rats fed
diets containing monophosphate salts (sodium dihydrogenphosphate, NaH2PO4, or
potassium dihydrogenphosphate, KH2PO4) or polyphosphate salts (sodium
tripolyphosphate, Na5P3O10, or potassium tripolyphosphate, K5P3O10), at levels
representing normal phosphorus (normal phosphorus diet) or high phosphorus (high
phosphorus diet) contents for 21 d. High phosphorus diet-feeding increased the
kidney calcium and phosphorus concentrations. Kidney calcium and phosphorus
concentrations were higher in rats fed the high phosphorus diet containing
Na5P3O10 or K5P3O10 than in rats fed the high phosphorus diet containing NaH2PO4
or KH2PO4. Nephrocalcinosis was observed in all rats fed a high phosphorus diet,
and the degree of nephrocalcinosis was more severe in rats fed Na5P3O10 or
K5P3O10 than in rats fed NaH2PO4 or KH2PO4. In rats fed the high phosphorus diet,
creatinine clearance was higher in rats fed Na5P3O10 or K5P3O10 than in rats fed
NaH2PO4 or KH2PO4. In rats fed Na5P3O10 or K5P3O10, urinary albumin excretion and
N-acetyl-beta-D-glucosaminidase (NAG) activity in the urine were increased in
rats fed the high phosphorus diet. These were higher in rats fed the high
phosphorus diet containing Na5P3O10 than in rats fed the high phosphorus diet
containing NaH2PO4 or KH2PO4. This study observed that the development of
nephrocalcinosis and kidney function in rats fed the high phosphorus diet was
influenced by the difference in monophosphate or polyphosphate salts provided as
the dietary phosphorus source, while the effects of sodium and potassium salts
were not evident. We suggest that the development of nephrocalcinosis and kidney
function in rats fed a high phosphorus diet was altered depending on the form of
phosphate salts provided as the dietary source of phosphorus. Additionally, the
development of nephrocalcinosis and diminished kidney function in rats fed the
high phosphorus diet was more severe for polyphosphate salts as compared to
monophosphate salts.
PMID- 10683812
TI - Ultrasonography evaluation of abdominal fat in live rats.
AB - We have developed a new noninvasive method of estimating abdominal fat volume in
live rats using ultrasonography. By this method, cross sections of perirenal
(retroperitoneal) fat tissue, which is an abdominal fat, at the renal vein level
could be identified and the area determined. The perirenal fat in Wistar rats
(wide body weight range, 111.4 to 497.3 g; limited range, 300.1 to 337.9 g)
measured by ultrasonography was compared with the actual fat tissue weight. The
cross-sectional area of perirenal fat tissue was significantly correlated to the
actual whole tissue weight. Using this procedure, we examined the changes of
perirenal fat stores during fasting. Consequently, the cross-sectional area of
perirenal fat and its actual weight decreased in parallel. Total body electrical
conductivity (TOBEC) is currently used to measure fat-free mass (FFM) and
indirectly predicts total body fat mass of live laboratory animals. The body fat
distribution, that is, the location of adipose tissue in the abdominal region, is
closely associated with obesity-related diseases. Therefore, it is important to
focus not only on the accumulation of total body fat, but also on that of
abdominal fat. The present ultrasonographic method is considered to be useful for
repeated noninvasive measurement of abdominal fat in the live rat.
PMID- 10683813
TI - The correlation between feed-intake cycle and nutritional zinc-deficient status
in rats.
AB - The characteristic cyclic variation in feed intake of rats fed a Zn-deficient
diet (Mills et al, Am J Clin Nutr 22: 1240-1249 (1969)) followed a Cosinor curve,
as determined by computer analysis (Tamaki et al, Br J Nutr 73: 711-722 (1995)).
The values of amplitude for the feed-intake cycle had a positive correlation to
their own day-to-day variations and to the correlation value of their own
simulated cycles (r2 = 0.764, df = 50, p < 0.001 and r2 = 0.682, df = 50, p <
0.001, respectively). The cyclic variation in feed intake was accompanied by a
cyclic variation in body-weight change in rats fed the Zn-deficient diet, and
cyclic variation in body-weight change occurred similarly in pair-fed control
rats. There were no differences in the mesors of body-weight change cycles of Zn
deficient rats and pair-fed control rats (Zn-deficient rats: 2.5 +/- 1.0 g/d,
pair-fed rats: 2.8 +/- 1.0 g/d, mean +/- SD, df = 18, t = -0.674, ND). Rats fed
the Zn-deficient diet were given different amounts of Zn supplementation by daily
subcutaneous injection. The amplitude of the feed-intake cycle was decreased with
increasing Zn supplementation (r2 = 0.919, df = 5, p < 0.001). The concentration
of Zn for the appearance of the feed-intake cycle was estimated to be 71.6 +/-
6.6 micrograms/d per rat. The Zn level in the serum showed a significant decrease
in the Zn-deficient diet groups, but the supplement of Zn did not vary in the Zn
deficient rats injected with up to 47.3 micrograms/d per rat. From these results,
an analysis of the feed-intake cycle allowed us to estimate the quantitative Zn
deficient status of rats.
PMID- 10683814
TI - Depletion of dietary n-3 fatty acid affects the level of cyclic AMP in rat
hippocampus.
AB - Prolonged depletion of dietary n-3 fatty acid induces a neurological disturbance.
To ascertain the deficit of neurotransmission at the time of n-3 deficiency, the
concentrations of cAMP and inositol triphosphate, and the activities of protein
kinases A and C were examined in vitro in rat hippocampus. Furthermore, the
saturation binding study of [3H]quinuclidinyl benzilate, a specific antagonist to
muscarinic cholinergic receptor, was performed. Rats were fed a safflower oil
diet as the deficient group and a soybean oil diet as the control group.
Hippocampi were obtained from rats in the 3rd generation in the deficient group
and in the 2nd generation in the control group. Dietary effect was not observed
in the parameters except for the concentration of cAMP, which was significantly
higher in the deficient group than in the control group.
PMID- 10683816
TI - The effect of docosahexaenoic acid on plasma catecholamine concentrations and
glucose tolerance during long-lasting psychological stress: a double-blind
placebo-controlled study.
AB - We previously found that docosahexaenoic acid (DHA) intake prevented aggression
from increasing at times of mental stress. In the present study, we investigated
whether DHA intake modified the plasma catecholamines and cortisol of medical
students during a 9-wk period of final exams. We also investigated the effects of
DHA intake on a 75 g oral glucose tolerance test (oGTT). Fourteen medical
students participated in the present study. They were randomly allocated to
either control or DHA group in a double-blind manner. Subjects in the control
group (4 males and 3 females) took 10 control capsules/d, each capsule containing
280 mg of mixed plant oil, and those in the DHA group (4 males and 3 females)
took 10 DHA capsules/d containing 1.5 g DHA for 9 wk, during which subjects
underwent more than 20 stressful final exams. At the start and end of the study,
plasma catecholamines (epinephrine, norepinephrine (NE) and dopamine) and
cortisol were measured; a 75 g oGTT was also performed. There were no intra- or
intergroup differences in plasma glucose concentrations. However, NE
concentrations were significantly reduced after DHA administration (-31%, p <
0.03). The other catecholamines and cortisol did not change significantly. The
plasma ratio of epinephrine to NE increased in every DHA subject (+78%, p <
0.02), and intergroup differences were significant (p < 0.03). We conclude that
these effects of DHA may be applied to people under long-lasting psychological
stress to prevent stress-related diseases.
PMID- 10683815
TI - Allylthiamindisulfide and related compounds enhance thermogenesis with increasing
noradrenaline and adrenaline secretion in rats.
AB - The effects of allylthiamindisulfide, an allyl derivative of thiamin, and related
compounds on thermogenesis were investigated by measuring noradrenaline and
adrenaline secretion and the temperatures of interscapular brown adipose tissue
(IBAT) and rectum in rats. In Experiment 1, the effects of the administrations of
allylthiamindisulfide and related compounds on noradrenaline and adrenaline
secretion were evaluated as compared to thiamin in anesthetized rats. The
administration of allylthiamindisulfide significantly increased the plasma
concentrations of noradrenaline and adrenaline. These increases were dose
dependent, while that of thiamin was not. Four synthetic compounds related to
allylthiamindisulfide also increased the plasma adrenaline and noradrenaline
concentrations. In Experiment 2, the effects of allylthiamindisulfide on
thermogenesis were investigated by the direct measurement of temperatures in the
IBAT and rectum in anesthetized rats, and compared to the effects induced by
thiamin and diallyldisulfide. The temperatures in the IBAT and rectum were
significantly increased by the administration of allylthiamindisulfide and
diallyldisulfide, while there was no significant increase as the result of
thiamin administration. These results suggest that allylthiamindisulfide and
related compounds enhance thermogenesis by increasing noradrenaline and
adrenaline secretion in rats.
PMID- 10683817
TI - Effects of high-fat diet intake on glucose uptake in central and peripheral
tissues of non-obese rats.
AB - We previously demonstrated that plasma glucose concentration was higher while
plasma insulin concentration was lower in rats fed a high-fat diet. In the
present study, we examined the effects of high-fat diet on glucose uptake in
central and peripheral tissues in non-obese rats. Forty male Sprague-Dawley rats
were fed high- or low-fat diets for 4 wk. Body weight and body fat accumulation
were not different between the two diet groups after 4 wk. Glucose uptake in the
skeletal muscles and adipose tissues, estimated by the 2-deoxy-D-glucose method,
was lower in the rats fed the high-fat diet than that in the rats fed the low-fat
diet, whereas uptake in the liver and pancreas did not differ between the two
groups. Glucose uptake in the hypothalamus and cortex was higher in the high-fat
diet group as compared with that in the low-fat diet group. These results suggest
that increased plasma glucose levels in rats fed the high-fat diet were caused by
a decrease in glucose uptake in the skeletal muscles and adipose tissues. Reduced
plasma insulin level in the high fat diet group with no difference in glucose
uptake in the pancreas may be due to increased sympathetic activity in the
pancreas resulting from the increased glucose uptake in the brain regions
involved in autonomic functions.
PMID- 10683818
TI - Towards the unknown.
PMID- 10683819
TI - Unipolar brush cells in marmoset cerebellum and cochlear nuclei express
calbindin.
AB - Unipolar brush cells (UBCs) are excitatory neurons in the mammalian cerebellum
and cochlear nuclei (CN), including the CN of primates, as shown only recently.
UBCs are readily identified by their expression of the calcium-binding protein
calretinin (CR), except for those of the primate CN that hardly immunostain for
CR. The present findings corroborate the existence of UBCs in the CN of a
primate, Callithrix. Furthermore, evidence is presented for UBCs, in the
cerebellum and a small subpopulation of UBCs in the CN of Callithrix to express
the calcium-binding protein calbindin (CB). This may be unique for Callithrix as
CB-expressing UBCs have not been recognized in any other mammal. Presence of CB
but not CR in UBCs of the Callithrix CN may indicate a certain interchangeability
between these two calcium-binding proteins.
PMID- 10683820
TI - Pattern of distribution and co-localization of NOS and ATP in the myenteric
plexus of human fetal stomach and intestine.
AB - The pattern of distribution and co-localization of nitric oxide synthase (NOS)
and quinacrine fluorescence (indicative of vesicular adenosine 5'-triphosphate,
ATP), and co-localization of NADPH-diaphorase (NADPH-d) activity and NOS
immunoreactivity in the myenteric plexus of pre-term human fetal (6-17 weeks of
gestation) stomach and small intestine was examined using immunohistochemical and
histochemical techniques. In all stages of gestation investigated, NOS
immunoreactive and NADPH-d-reactive myenteric neurons and nerve fibres were seen
in the fetal intestine and stomach. However, in fetuses of 6-10 weeks of
gestation, only 15% of the NADPH-d-positive myenteric neurons were NOS
immunoreactive, whereas a 100% co-localization was found in samples of 12-17
weeks of gestation. Quinacrine fluorescent myenteric neurons and nerve fibres
were found only in the fetal intestine of 12-17 weeks of gestation, of which 25%
of the NADPH-d-positive myenteric neurons in these samples were quinacrine
fluorescent. These findings demonstrate the presence and co-localization of
markers for nitric oxide (NO)- and ATP-utilizing myenteric neurons and nerve
fibres in the early stages of gestation, suggesting possible co-transmitter
and/or trophic roles of ATP and NO in the process of development and maturity of
human myenteric neurons. In addition, the fact that only a small percentage of
NADPH-d-reactive myenteric neurons express NOS immunoreactivity at 6-10 weeks of
gestation confirms that NADPH-d-reactivity does not always represent NOS
activity.
PMID- 10683821
TI - Immunolocalization of NAIP in the human brain and spinal cord.
AB - The neuronal apoptosis inhibitory protein (NAIP) is known to have anti-apoptotic
functions, and its gene is often mutated in severe cases of spinal muscular
atrophy (SMA), a disease characterized by motor neuron degeneration. In this
study, we examined the distribution of the endogenous NAIP protein in normal
human spinal cord and brain tissue by using a polyclonal antibody against NAIP.
Immunohistochemical staining demonstrated that NAIP is strongly expressed in
anterior horn and motor cortex neurons of normal brains, and it is not altered in
the remaining motor neurons of patients with amyotrophic lateral sclerosis (ALS).
NAIP is also located in human fetal neurons and in adult choroid plexus cells.
These results suggest that the anti apoptotic molecule NAIP may be important in
motor neurons, but it specifically does not appear to be altered in ALS.
PMID- 10683822
TI - MRI T2 shortening ('black T2') in multiple sclerosis: frequency, location, and
clinical correlation.
AB - Abnormal iron deposition occurs in the brains of patients with multiple sclerosis
(MS) and may cause MRI T2 shortening ('black T2'; BT2). The frequency,
distribution and clinical significance of BT2 in MS is unknown. Analysis of brain
MRI scans of 114 MS patients showed BT2 in thalamus (n = 65; 57%), putamen (n =
48; 42%), caudate (n = 27; 24%) and Rolandic cortex (n = 9; 8%). BT2 was
significantly related to longer disease duration and advancing neurological
disability. Wheelchair-bound patients had worse BT2 in thalamus (p < 0.05),
putamen (p < 0.001) and Rolandic cortex (p < 0.05). Patients with secondary
progressive disease (n = 34) had worse BT2 in thalamus, putamen and caudate (all
p < 0.05) than those with relapsing remitting disease (n = 80). BT2 is proposed
as a clinically relevant finding relating to neuronal degeneration in MS.
PMID- 10683823
TI - Noradrenaline does not change the mode of discharge of auditory cortex neurons.
AB - The mode of discharge of auditory cortex cells was studied during iontophoretic
application of noradrenaline (NA). Only seven of 190 cells showed changes in
interspike interval distribution during NA application. A similar conclusion was
drawn when the analysis focused on 68 cells classified as bursting (n = 15),
regular spiking (n = 49) or thin spike (n = 4) cells. Only two bursting cells
showed changes in their ISI distribution. The effects on the mode of discharge
were independent of the effect on the spike rate and were not a function of
cortical depth. These results suggest that the changes in firing mode previously
described in vitro occur for a limited percentage of cells and/or for cell types
not very often recorded in vivo.
PMID- 10683824
TI - Distribution of PDE4A and G(o) alpha immunoreactivity in the accessory olfactory
system of the mouse.
AB - Distribution of the cAMP-specific phosphodiesterase PDE4A was examined in the
accessory olfactory system by immunohistochemistry. Adjacent sections through the
vomeronasal organ (VNO) and accessory olfactory bulb (AOB) were alternately
immunostained with antibodies against PDE4A or the G-protein alpha subunit G(o)
alpha, which labels basal VNO neurons, in order to determine whether PDE4A occurs
preferentially in one of two segregated VNO pathways. We found that PDE4A
strongly labeled apical VNO neurons and rostral AOB glomeruli. There was
virtually no overlap in G(o) alpha and PDE4A staining, and there were no regions
of the VNO neuroepithelium or AOB glomeruli not labeled by either antibody. These
results identify a potential member of the pheromone transduction cascade in
apical neurons, and provide further evidence that the VNO consists of
functionally distinct pathways.
PMID- 10683825
TI - Activity-related changes in intracellular pH in rat thalamic relay neurons.
AB - Activity-related shifts in intracellular pH (pHi) can exert potent
neuromodulatory actions. Different states of neuronal activity of thalamocortical
neurons were found to differentially modulate pHi. Tonic activity evoked by
injection of depolarizing current led to a reversible rise in [H+]i which was
nearly abolished in the presence of TTX. Block of voltage-gated calcium channels
with I mM Ni2+ reduced the [H+]i transients related to tonic activity. Rhythmic
activation of burst discharges caused changes of [H+]i which were decreased by
TTX, whereas I mM Ni2+ almost abolished the [H+]i transients. The present results
show that different forms of neuronal activity can lead to intracellular
acidification caused by different mechanisms, i.e. Na+ and Ca2+ influx through
sodium and Ca2+ channels, respectively, and the subsequent activation of a
Ca2+/H+ pump. The resulting acidosis is suggested to reduce further Ca2+ influx
and prevent excessive neuronal excitation.
PMID- 10683826
TI - Suppression of gamma activity in the human medial temporal lobe by sevoflurane
anesthesia.
AB - We have reported the presence of continuous gamma (30-150 Hz) activity in the
human medial temporal lobe (MTL). Since the MTL is involved in learning and
memory, we speculated that MTL gamma activity is related to such higher brain
functions. It is thus of interest to learn how this activity changes during
different states of consciousness. In this study, we recorded
electrocorticographic (ECoG) activity directly from the surface of the MTL after
various doses of sevoflurane anesthesia. Five epileptic patients underwent
electrode placement operations in which electrodes were attached to the surfaces
of the MTL and the basal temporal lobe (BTL). Immediately following the operation
ECoG was recorded from each patient under four concentrations of sevoflurane
anesthesia (1.5, 2.0, 2.5 and 3.0%). Fast Fourier Transform (FFT) analysis was
performed on the MTL ECoGs. Under the lowest sevoflurane concentration, MTL gamma
activity was observed in all patients. However, gamma activity was progressively
suppressed by increased concentrations of sevoflurane, in a dose-dependent
manner. Sevoflurane has been known to reduce neuronal excitability in the rat
hippocampus in vitro, probably by changing GABAergic inhibition. The reduction of
MTL gamma in the present study may be the result of such a mechanism. Although
memory function was not tested in this study, the amount of MTL gamma activity
may be related to residual memory function during anesthesia.
PMID- 10683827
TI - Modulating emotional responses: effects of a neocortical network on the limbic
system.
AB - Humans share with animals a primitive neural system for processing emotions such
as fear and anger. Unlike other animals, humans have the unique ability to
control and modulate instinctive emotional reactions through intellectual
processes such as reasoning, rationalizing, and labeling our experiences. This
study used functional MRI to identify the neural networks underlying this
ability. Subjects either matched the affect of one of two faces to that of a
simultaneously presented target face (a perceptual task) or identified the affect
of a target face by choosing one of two simultaneously presented linguistic
labels (an intellectual task). Matching angry or frightened expressions was
associated with increased regional cerebral blood flow (rCBF) in the left and
right amygdala, the brain's primary fear centers. Labeling these same expressions
was associated with a diminished rCBF response in the amygdalae. This decrease
correlated with a simultaneous increase in rCBF in the right prefrontal cortex, a
neocortical region implicated in regulating emotional responses. These results
provide evidence for a network in which higher regions attenuate emotional
responses at the most fundamental levels in the brain and suggest a neural basis
for modulating emotional experience through interpretation and labeling.
PMID- 10683828
TI - Knock down of spinal NMDA receptors reduces NMDA and formalin evoked behaviors in
rat.
AB - Chronic pain remains a major health problem afflicting an estimated 70% of
patients with advanced cancer and inflammatory disorders, and up to 94% of
patients with spinal cord injuries. Although progress has been made in the
pharmacotherapy of chronic pain management, such as usage of adjuvant drugs and
more effective methods of drug delivery, the mainstay of clinical pain management
still depends on opiates. NMDA receptor activation, at the level of the spinal
cord has been shown to play an important role in the facilitation of nociception
(pain) in several animal models. Unfortunately, potent NMDA receptor antagonists,
such as MK-801 and APV, have toxic properties and low safety margins that
preclude their clinical use. We present evidence which indicates that the use of
antisense oligonucleotides targeted to the NMDA-R1 receptor subunit (AS-NMDA-R1),
but not sense, abolishes NMDA and formalin induced behaviors. Moreover, we
demonstrate that spinal administration of AS-NMDA-R1 results in the abolition of
staining for immunoreactive NMDA-R1 in the spinal cord. These data provide novel
evidence supporting the feasibility of the use of gene therapy approaches in the
management of neuropathic pain.
PMID- 10683829
TI - Pro-apoptotic effects of tau mutations in chromosome 17 frontotemporal dementia
and parkinsonism.
AB - It was recently discovered that mutations of tau cause hereditary frontotemporal
dementia and parkinsonism linked to chromosome 17 (FTDP-17). Here we report that
cultured SH-SY5Y human neuroblastoma cells transfected with mutated tau genes are
more vulnerable to apoptotic stimulus. Two kinds of mutations of tau causing FTDP
17 were examined in the present study: one was in exon 10 (N279K) and the other
was in exon 12 (V337M). SH-SY5Y cells transfected with either mutated tau were
more vulnerable to serum withdrawal, whereas cells transfected with the wild-type
tau or vector alone showed no significant change in apoptotic vulnerability. The
increase in the intracellular calcium concentration by the serum withdrawal was
significantly greater in the SH-SY5Y cells transfected with mutated tau genes
than in cells transfected with the wild-type tau or vector alone. These results
suggest that mutations of tau might cause FTDP-17 by these pro-apoptotic
functions by disrupting the intracellular calcium homeostasis.
PMID- 10683830
TI - Evidence that the mismatch negativity system works on the basis of objects.
AB - The purpose of this study was to determine whether the system that underlies the
mismatch negativity (MMN) of event-related potentials would operate on the basis
of objects if stimuli were delivered in such a way as to create the impression of
two objects. To this end, tones were alternated between ears with one combination
of features for each ear. Deviant tones, which differed from the standard tones
of both ears, were delivered separately to each ear. The deviants elicited MMNs
only with respect to the standards of the ear to which they were delivered. The
data indicate that the MMN system operated on the basis of objects and that the
integration of objects occurs preattentively in the auditory system.
PMID- 10683831
TI - Nerve growth factor treatment alters Ca2+ pump levels in PC12 cells.
AB - Nerve growth factor (NGF) treatment converts rapidly dividing PC12 cells into a
neuronal phenotype. To understand the Ca2+ sequestration mechanisms accompanying
this differentiation, we examined the endoplasmic reticulum Ca2+ (SERCA) pump
levels using two different assays: ATP-dependent azide insensitive oxalate
stimulated 45Ca2+ uptake by PC12 cells permeabilized with saponin, and Western
blots using a monoclonal antibody which reacts with all the SERCA isoforms. We
also examined the reaction to an antibody against the plasma membrane Ca2+ (PMCA)
pump. NGF treatment decreased the SERCA pump expression but it increased the PMCA
pump level. These results are consistent with a greater role of PMCA pumps in
neuronal cells than in most other cells and with an increased role of SERCA pumps
during cell proliferation.
PMID- 10683832
TI - The N170 occipito-temporal component is delayed and enhanced to inverted faces
but not to inverted objects: an electrophysiological account of face-specific
processes in the human brain.
AB - Behavioral studies have shown that picture-plane inversion impacts face and
object recognition differently, thereby suggesting face-specific processing
mechanisms in the human brain. Here we used event-related potentials to
investigate the time course of this behavioral inversion effect in both faces and
novel objects. ERPs were recorded for 14 subjects presented with upright and
inverted visual categories, including human faces and novel objects (Greebles). A
N170 was obtained for all categories of stimuli, including Greebles. However,
only inverted faces delayed and enhanced N170 (bilaterally). These observations
indicate that the N170 is not specific to faces, as has been previously claimed.
In addition, the amplitude difference between faces and objects does not reflect
face-specific mechanisms since it can be smaller than between non-face object
categories. There do exist some early differences in the time-course of
categorization for faces and non-faces across inversion. This may be attributed
either to stimulus category per se (e.g. face-specific mechanisms) or to
differences in the level of expertise between these categories.
PMID- 10683833
TI - Topiramate depresses carbachol-induced plateau potentials in subicular bursting
cells.
AB - Intracellular recordings were made in an in vitro slice preparation to establish
whether the antiepileptic drug topiramate reduces the depolarizing plateau
potentials (PPs) induced in the rat subiculum by intracellular pulses of
depolarizing current, in the presence of the cholinergic agonist carbachol (CCh,
70-100 microM). PPs lasted up to about 2 s, and disappeared during application of
the muscarinic receptor antagonist atropine. Topiramate (10-100 microM, n = 22
neurons) decreased and eventually abolished in a dose-dependent manner these PPs,
even when the function of excitatory amino acid and GABAA receptors was blocked.
Hence, topiramate depresses muscarinic receptor-dependent PPs in the rat
subiculum, thus suggesting that this form of excitation may represent a target
for the mechanism of action of this antiepileptic compound.
PMID- 10683834
TI - Developmental prosopagnosia with normal configural processing.
AB - The configural processing hypothesis proposes that prosopagnosia results from a
domain-general impairment in configural processing, and so predicted that all
prosopagnosics would have impaired configural processing. In order to test this
prediction, tests of face recognition and configural processing were presented to
a developmental prosopagnosic. He was severely impaired in face recognition, but
his normal performance on three tests of configural processing disconfirmed the
configural processing hypothesis. Additional tests of low-level vision and object
recognition found no evidence of impairments with material other than faces. The
pattern of spared and impaired face recognition indicates that this case of
developmental prosopagnosia is caused by a domain-specific inability to match
novel views of faces with previously derived representations.
PMID- 10683835
TI - SNAP-25 is present on the Golgi apparatus of retinal neurons.
AB - SNAP-25 is a neuronal SNARE protein required for synaptic vesicle exocytosis and
neurite outgrowth. Here we show that in addition to synaptic staining, SNAP-25
immunoreactivity is also localized to an intracellular, perinuclear compartment
of retinal neurons. Double-labeling with an antibody against the 58 kD resident
protein of the trans-golgi network indicates that the intracellular SNAP-25 is
localized to the Golgi complex. Immuno-electron microscopic localization of SNAP
25 confirmed its presence on the Golgi apparatus of photoreceptors, bipolar
cells, amacrine cells and ganglion cells in the retina. These data implicate SNAP
25 in the trafficking of Golgi-derived vesicles in neurons in addition to the
synaptic vesicle cycle.
PMID- 10683836
TI - Astrocytes in chronic active multiple sclerosis plaques express MHC class II
molecules.
AB - To initiate the inflammatory cascade leading to demyelination in multiple
sclerosis (MS) T cells have to recognize their specific myelin antigen, which
needs to be presented in the context of major histocompatibility (MHC) class II
molecules expressed on antigen presenting cells. Whether astrocytes can express
MHC class II molecules in vivo is a controversial issue. We performed double
labeling immunohistochemistry in postmortem samples from nine patients with MS,
three patients with a cerebral infarction and six controls. Astrocytes in
controls, in normal appearing white matter in MS, and at the boundary of
infarctions were MHC class II negative. In contrast, a subset of astrocytes in
active chronic plaques immunostained for MHC class II, indicating potential
antigen presenting interactions of astrocytes in MS.
PMID- 10683837
TI - A sparse projection from the suprachiasmatic nucleus to the sleep active
ventrolateral preoptic area in the rat.
AB - The circadian clock of the suprachiasmatic nucleus (SCN) may control the sleep
wake cycle by modulating the activity of brain regions important in sleep onset
and maintenance, such as the ventrolateral preoptic area (VLPO). The aim of this
study was to determine whether the VLPO receives direct projections from the SCN.
The retrograde tracer cholera toxin (beta subunit; CT beta) was injected into the
VLPO of male rats and the SCN was examined for the presence of labeled, VLPO
projecting neurons. After injections restricted to the VLPO only a few labeled
cells were found within the SCN, with more labeled cells located around the
nucleus. Therefore, the circadian regulation of the VLPO is likely to be achieved
through multisynaptic pathways or via a diffusible signal, rather than by direct
axonal outputs from the SCN to the VLPO.
PMID- 10683838
TI - Parvalbumin-immunoreactive neurons in the human anteroventral thalamic nucleus.
AB - We immunohistochemically characterised the expression of the calcium-binding
protein parvalbumin in the normal human anteroventral thalamic nucleus (AVN). Two
morphologically distinct neuronal populations were found to be parvalbumin
immunoreactive (PV-IR): a large population of lightly staining PV-IR neurons and
a smaller population of intensely PV-IR neurons. This second type of neuron,
which displayed many characteristics normally associated with GABAergic
interneurons, has not previously been described in human thalamus. Thus,
presumptive thalamic interneurons in the human brain can be further subtyped on
the basis of immunoreactivity to parvalbumin. This may have implications for the
understanding of thalamocortical function in the normal state and in
dysfunctional conditions such as Wernicke-Korsakoff syndrome and schizophrenia.
PMID- 10683839
TI - Hypocretin I in the lateral hypothalamus activates key feeding-regulatory brain
sites.
AB - Hypocretin I (also referred to as orexin A) administered into the lateral
hypothalamus (LH) stimulates feeding in rats. We undertook the present study to
determine the brain regions activated by LH administration of hypocretin I.
Hypocretin I administered into the LH significantly elevated cFos
immunoreactivity in the lateral septal area, the central nucleus of the amygdala,
the shell of the nucleus accumbens, the bed nucleus of the stria terminalis, the
LH, the posterior and dorsomedial hypothalamus, the perifornical, arcuate and
paraventricular nuclei and the nucleus of the solitary tract. These data indicate
that LH hypocretin I communicates with other key energy regulatory sites within
the hypothalamus, the limbic region and the hindbrain, and suggest that these
areas are important in the feeding-stimulatory actions of hypocretin I.
PMID- 10683840
TI - New aspects of motion perception: selective neural encoding of apparent human
movements.
AB - Perception of apparent motion operates somewhat differently for objects and human
figures. Depending on the interstimulus interval, the latter d may give rise to
either perception of a direct path (i.e. biologically impossible) or indirect
path (i.e. biologically possible). Here, PET was used to investigate whether a
change in brain activity accompanies this perceptual shift. We found neural
encoding of apparent motion to be a function of the intrinsic properties of the
stimulus presented (object vs human) as well as the kind of human movement path
perceived (biomechanically possible vs impossible). Motor and parietal cortex
were only involved for possible motion which suggests that these regions are
selectively activated to process actions which conform to the capabilities of the
observer.
PMID- 10683841
TI - Effect of 2-mercaptoacetate and 2-deoxy-D-glucose administration on the
expression of NPY, AGRP, POMC, MCH and hypocretin/orexin in the rat hypothalamus.
AB - Using in situ hybridization, the mRNA levels encoding neuropeptide Y (NPY),
agouti gene-related protein (AGRP), proopiomelanocortin (POMC), melanin
concentrating hormone (MCH) and hypocretin/orexin (HC/ORX) were investigated in
the rat arcuate nucleus (Arc) and lateral hypothalamic area (LHA) 2 h after a
single dose of the glucose antimetabolite 2-deoxy-D-glucose (2-DG; 600 mg/kg) or
of the fatty acid oxidation inhibitor mercaptoacetate (MA; 600 mumol/kg). Two
hours after 2-DG or MA injection food intake was significantly increased. NPY and
AGRP mRNA levels in the Arc were increased by 2-DG but not affected by MA, and
MCH mRNA levels in the LHA were increased by both antimetabolites. These results
suggest that Arc neurons expressing NPY and AGRP are regulated by changes in
glucose, but not fatty acid availability, whereas both factors affect MCH neurons
in the LHA.
PMID- 10683842
TI - Brain representation of habituation to repeated complex visual stimulation
studied with PET.
AB - To investigate CNS habituation (i.e. response decrement due to stimulus
repetition) the present study used positron emission tomography (PET) to measure
regional cerebral blood flow (rCBF) in eight healthy women during two repetitions
of complex visual stimuli. Repeated visual stimulation resulted in neural
habituation bilaterally in the secondary visual cortex and in the right medial
temporal cortex including the amygdala and the hippocampus. Regional CBF in the
left thalamus was elevated as a function of repeated stimuli presentations. Thus,
repeated presentation of complex visual stimuli result in rCBF habituation in
later stages of the visual processing chain. The elevated neural activity in the
thalamus might be associated with interruption of further neural transmission
related to suppression of non-meaningful behavior.
PMID- 10683843
TI - A laboratory study of sleep in Asperger's syndrome.
AB - Asperger's syndrome (AS) is a pervasive developmental disorder that may fall
along the autistic spectrum. We compared the sleep of eight patients with AS with
that of participants matched for age and gender. Patients with AS showed
decreased sleep time in the first two-thirds of the night, increased number of
shifts into REM sleep from a waking epoch, and all but one patient showed signs
of REM sleep disruption. EEG sleep spindles were significantly decreased while K
complexes and REM sleep rapid eye movements were normal. Three patients with AS,
but none of the comparison participants, showed a pathological index of periodic
leg movements in sleep. These observations show that sleep disorders are
associated with AS and suggest that defective sleep control systems may be
associated with the clinical picture of AS.
PMID- 10683844
TI - Subdural applications of NO scavenger or NO blocker to the cerebellum depress the
adaptation of monkey post-saccadic smooth pursuit eye movements.
AB - We examined pharmacologically whether cerebellar long-term depression (LTD) may
play a role in the adaptation of smooth pursuit eye movements in two Macaca
fuscata, which were trained to pursue a target moving in the horizontal plane in
a 3 degrees step-10 deg/s ramp mode. The monkeys showed small catch-up saccades
followed by 6-8 deg/s post-saccadic pursuit movements. Adaptation of the post
saccadic pursuit velocity was induced by repetition of acceleration of the target
to 20 deg/s after the catch-up saccades. Injections of 0.1 mM hemoglobin or 20 mM
NG-monomethyl-L-arginine solution into the subdural space above the paraflocculus
flocculus scarcely affected the post-saccadic pursuit velocity, but markedly
depressed its adaptation. These observations suggest that cerebellar LTD may
underlie the adaptation of smooth pursuit.
PMID- 10683845
TI - Dorsolateral prefrontal cortex and the implicit association of concepts and
attributes.
AB - The Implicit Association Test (IAT) examines the differential association of two
object categories (e.g. flower and insect) with attribute categories (e.g.
pleasant and unpleasant). When items from congruent categories (e.g. flower +
pleasant) share a response key, performance is faster and more accurate than when
items from incongruent categories (e.g. insect + pleasant) share a key.
Performing incongruent word classification engages inhibitory processes to
overcome the prepotent tendency to map emotionally congruent items to the same
response key. Using fMRI on subjects undergoing the IAT, we show that the left
dorsolateral prefrontal cortex, and to a lesser extent the anterior cingulate
cortex, mediate inhibitory processes where manipulation of word association is
required.
PMID- 10683846
TI - Branchiomotor activities in mouse embryo.
AB - Using a novel isolated hindbrain in vitro preparation, we demonstrate that, in
the mouse, branchiomotor activities from trigeminal, facial, glossopharyngeal and
vagal nerves start during segmentation, a crucial and conserved period of
hindbrain embryogenesis. At embryonic day (E) 10.5, branchiomotor nerves are
independently active in bursts, become coactive at a low frequency (about 0.5 min
1) at E12.5, before high frequency (about 15 min-1) fetal breathing starts at
E14.5. Comparison with observations in chick reveals a transient episodic
rhythmic pattern highly similar in mouse at E13.5 and chick at E7. This pattern
is proposed as a marker identifying a phylotypic stage during the development of
hindbrain neuronal networks in vertebrates.
PMID- 10683847
TI - The representation of the plegic hand in the motor cortex: a combined fMRI and
TMS study.
AB - TMS mapping and fMRI were used to investigate changes in the motor cortex
representation of the hand in a patient with complete loss of right hand function
following traumatic avulsion of the cervical roots C7 and C8. Both TMS and fMRI
demonstrated an expansion of the motor representation of the forearm into the
hand area contralateral to the injured side. fMRI of the hand area, however,
revealed that this area could still be activated when the patient was instructed
to imagine finger tapping with his plegic hand. These results indicate that the
plegic hand is still represented in the motor cortex, despite the fact that the
same cortical area is also now active during movements involving forearm muscles.
PMID- 10683848
TI - Alteration of veratridine neurotoxicity in sympathetic neurons during development
in vitro.
AB - Neurotoxic effects of veratridine, the activator of voltage-dependent Na+
channels, were examined at various stages of in vitro development of superior
cervical ganglion cells dissociated from newborn rats. Veratridine neurotoxicity
did not occur in 1DIV (days in vitro) neurons, but occurred in 7DIV neurons, both
of which depend on NGF for survival, but elevated K+ supports only the latter.
TUNEL and electron microscopic analyses revealed that 7DIV neurons underwent both
apoptotic and necrotic cell death. Veratridine was also toxic to 21DIV neurons
which are independent of NGF for survival. Nuclear features of apoptosis,
however, were greatly reduced in these neurons undergoing cell death, suggesting
that nuclear vulnerability is also subject to developmental regulation in vitro.
PMID- 10683849
TI - Mood state and brain electric activity in ecstasy users.
AB - Resting EEG during open and closed eyes and subsequent mood ratings were obtained
from 15 Ecstasy users and 14 Ecstasy-naive controls. Absolute spectral power on
the scalp, and the three-dimensional, intracerebral distribution of neuroelectric
activity using low resolution brain electromagnetic tomography (LORETA) were
computed. LORETA revealed global increases of theta, alpha 1 and beta 2/3 power
during eyes open in Ecstasy users, and spectral analyses revealed a right
posterior increase of alpha 2 power (confirmed by LORETA) and increased beta band
activity during open eyes. Ecstasy users had higher levels of state
depressiveness, emotional excitability and a trend-level increase in state
anxiety. The observed differences may be related to regular exposure to Ecstasy
or other illicit drugs, or may be pre-existing.
PMID- 10683850
TI - Histamine H3-receptor activation inhibits dopamine synthesis in rat striatum.
AB - Unilateral 6-hydroxydopamine lesion to rat substantia nigra pars compacta
resulted in a modest, but significant, decrease in the specific binding of N
alpha-[methyl-3H]histamine (19 +/- 5% reduction) to synaptosomal membranes from
ipsilateral striata. Dopamine synthesis was assessed in striatal slices by
determining [3H]DOPA accumulation after inhibition of DOPA decarboxylase.
[3H]DOPA synthesis induced by 50 mM K+ (151 +/- 4% of basal) was prevented by
either Ca2+ removal or by Ni2+. Depolarization-stimulated [3H]DOPA accumulation
was reduced by the selective H3-agonist immepip (100 nM; 68 +/- 7% inhibition).
The effect of immepip was reversed by thioperamide (100 nM), a selective H3
antagonist. Taken together, our results indicate that histamine modulates
striatal dopamine synthesis by acting at H3-receptors located on dopaminergic
nerve terminals.
PMID- 10683851
TI - Selective increase in cellular A beta 42 is related to apoptosis but not
necrosis.
AB - Amyloid beta protein ending at 42 (A beta 42) plays an important role in the
pathology of Alzheimer's disease (AD). Here we show an increase in cellular A
beta 42 in damaged neurons, with both ELISA and immunocytochemistry. The cellular
A beta 42 increase was caused by 3-day treatments with H2O2, etoposide or
melphalan, all of which induce genotoxic apoptosis, but not by treatment with
sodium azide, which causes necrosis. Secreted A beta was similarly decreased with
all these treatments. The cellular A beta 42 increase appeared even with minimal
damage (ELISA) and A beta 42-positive cells were TUNEL negative (double
staining), indicating that any early apoptosis mechanism may induce the cellular
A beta 42 increase. Thus, neuronal apoptosis and cellular A beta 42 increase may
be linked in a way that contributes importantly to AD pathology.
PMID- 10683852
TI - Effects of dizocilpine (MK 801) on noradrenaline, serotonin and dopamine release
and uptake.
AB - In the present study, we examined the actions of the NMDA antagonist dizocilpine
(MK801) on electrically evoked release and uptake of noradrenaline (NA) in the
locus coeruleus (LC), serotonin (5-HT) in the dorsal raphe nucleus (DRN) and
dopamine (DA) in the nucleus accumbens (NAc), measured by fast cyclic voltammetry
(FCV) in rat brain slices. Dizocilpine (10 microM) significantly increased NA (to
248 +/- 15%) and 5-HT release (to 184 +/- 29%) and slowed monoamine uptake in the
LC (t1/2 = 853 +/- 129%) and the DRN (t1/2 = 387 +/- 70%), respectively. However,
dizocilpine had no effect on DA release or uptake in NAc. Actions on monoamines
are thus likely and should be considered in the interpretation of data regarding
dizocilpine.
PMID- 10683853
TI - Early damage of sympathetic neurons after co-culture with macrophages: a model of
neuronal injury in vitro.
AB - Since activated immune cells may damage peripheral nerves during inflammation, we
developed a co-culture model that permits the direct study of macrophage-induced
neuronal damage. Sympathetic neurons were enzymatically isolated from neonatal
mice and co-cultured with increasing numbers of peritoneal macrophages for 24 h.
This caused rapid neuronal cell death, reducing neuronal number by 24.1 +/- 4%
with the addition of 11.5 x 10(3) macrophages, representing a ratio of 8
macrophages per neuron. Nuclear analysis showed that cell death occurred by both
apoptosis and necrosis. These effects were not mimicked by addition of macrophage
conditioned medium, and were prevented by 10 microM dexamethasone. Although no
appreciable neuronal death occurred beyond 24 h, the density of neurites was
decreased between 1 and 2 days of co-culture (p < 0.05). There is, therefore, a
rapid induction of cytotoxicity by macrophages after their addition to the
neuronal cultures, followed by axonal damage without neuronal cell death.
PMID- 10683854
TI - Effects of dalargin on excitation induced by L-glutamate agonists in the frog
vestibular organs.
AB - We have used an electrophysiological approach to investigate the action of a
synthetic analog of leu-enkephalin dalargin (DAL) on chemically induced afferent
activity in the frog vestibular organs. Administration of 5.0 microM kainic acid
(KA), 5.0 microM (AMPA) and 50 microM NMDA produced an increase in the frequency
of the resting discharge. Firing evoked by KA, AMPA or NMDA could be depressed by
administration of 1 nM Dal by 55.5 +/- 9.9% (n = 10, p < 0.05), 64.5 +/- 11.2% (n
= 13, p < 0.05) and 21.3 +/- 11.1% (n = 14, p = 0.051), respectively. Thus, the
frequency decrease under NMDA was statistically non-significant. These results
show that non-NMDA, but not NMDA subtypes of receptors are mostly involved in
opioid action at the vestibular organs of the frog.
PMID- 10683855
TI - Somatosensory areas in man activated by moving stimuli: cytoarchitectonic mapping
and PET.
AB - This study was performed to identify neuronal populations in the somatosensory
areas engaged in discrimination of moving stimuli on the skin. Changes in
regional cerebral blood flow (rCBF) were measured with positron emission
tomography (PET) and correlated with cytoarchitectonic sensorimotor areas 4a, 4p,
3a, 3b, and 1. Volunteers discriminated differences in the speed of a rotating
brush stimulating the palmar surface. Discrimination of moving stimuli,
contrasted to rest, increased the rCBF mainly in primary somatosensory (SI) area
1, but also in area 3b. The parietal operculum (PO) was activated bilaterally. We
conclude that area 1 is the area in SI which is mainly responding to
discrimination of moving stimuli and that the PO contains several regions engaged
in the discrimination of fast transient stimuli.
PMID- 10683856
TI - Role of central adenosine in the respiratory and thermoregulatory responses to
hypoxia.
AB - No reports are available about the role of central adenosine in the respiratory
and thermoregulatory responses to hypoxia in conscious rats. We therefore
measured ventilation (VE) and body temperature (Tb) before and after
intracerebroventricular injection of saline or aminophylline (adenosine
antagonist), followed by a 30-min period of hypoxia exposure. Aminophylline did
not change VE or Tb during normoxia; however, during hypoxia, it caused a
significant increase in VE, and significantly attenuated hypoxic hypothermia. The
present data indicate that central adenosine has an inhibitory effect on hypoxic
hyperventilation and partially causes hypoxic hypothermia, suggesting that the
ventilatory and metabolic interaction during hypoxia does not involve opposing
mechanisms.
PMID- 10683857
TI - Localization of the tetrodotoxin-resistant sodium channel NaN in nociceptors.
AB - Tetrodotoxin-resistant sodium currents contribute to the somal and axonal sodium
currents of small diameter primary sensory neurons, many of which are
nociceptive. NaN is a recently described tetrodotoxin-resistant sodium channel
expressed preferentially in IB4-labeled dorsal root ganglion (DRG) neurons. We
employed an antibody raised to a NaN specific peptide to show that NaN is
preferentially localized along axons of IB4-positive unmyelinated fibers in the
sciatic nerve and in axon terminals in the cornea. NaN immunoreactivity was also
found at some nodes of Ranvier of thinly myelinated axons of the sciatic nerve,
where it was juxtaposed to Kv1.2 potassium channel immunoreactivity. This
distribution of NaN is consistent with a role for NaN sodium channels in
nociceptive transmission.
PMID- 10683858
TI - Estimation of photoparoxysmal response elicited by half-field visual stimulation.
AB - We examined photoparoxysmal responses (PPRs) elicited by half-field visual
stimulation with deep-red flicker light to determine the neurophysiological
features of photosensitive epilepsy (PSE). EEG revealed two types of PPRs. One
had the focal spike in the occipital region and the other in the temporo
occipital region at the contralateral hemisphere. The equivalent current dipoles
of these types were located at the occipital cortex and the inferior temporal
(IT) cortex, respectively. These cortices comprise one of the main pathways in
the visual system, and they play important roles in color discrimination. Thus,
we propose that the visual system, especially the occipital cortex and the IT
cortex, might be involved in the generator mechanism of PSE.
PMID- 10683859
TI - Sound-induced laryngeal and respiratory reflexes originate from vestibular
afferents.
AB - To determine whether the auditory or vestibular system causes the sound-induced
laryngeal reflex, which has been considered to participate in the auditory
feedback control of vocalization, click-induced laryngeal responses were compared
before and after sectioning of the cochlear and/or vestibular nerves in cats. The
sound-induced reflex modulation of respiratory muscle activity was also
investigated, because respiratory movement is important for vocal control.
Sectioning of the cochlear nerves had little influence on these responses. In
contrast, sectioning of the vestibular nerves abolished these responses. It was
concluded that the sound-induced laryngeal and respiratory reflexes are
attributed to the vestibular system.
PMID- 10683860
TI - MPTP induces alpha-synuclein aggregation in the substantia nigra of baboons.
AB - 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity reproduces many
of the features of Parkinson's disease (PD). alpha-Synuclein has been identified
as a prominent component of the Lewy body (LB), the pathological hallmark of PD.
MPTP-treated primates have been reported to develop intraneuronal inclusions but
not true Lewy bodies. We administered MPTP to baboons and used a monoclonal alpha
synuclein antibody to define the relationship between neuronal degeneration and
alpha-synuclein immunoreactivity in the substantia nigra. MPTP-induced neuronal
degeneration was associated with the redistribution of alpha-synuclein from its
normal synaptic location to aggregates in degenerating neuronal cell bodies.
alpha-Synuclein aggregation induced by MPTP models the early stages of Lewy body
formation and may be a fundamental step in the evolution of neuronal degeneration
in PD.
PMID- 10683861
TI - Serotonin transporter gene polymorphism and antidepressant response.
AB - We examined allelic polymorphisms of the serotonin transporter (5-HTT) gene and
antidepressant response to 6 weeks' treatment with the selective serotonin
reuptake inhibitor (SSRI) drugs fluoxetine or paroxetine. We genotyped 120
patients and 252 normal controls, using polymerase chain reaction of genomic DNA
with primers flanking the second intron and promoter regions of the 5-HTT gene.
Diagnosis of depression was not associated with 5-HTT polymorphisms. Patients
homozygous l/l in intron 2 or homozygous s/s in the promoter region showed better
responses than all others (p < 0.0001, p = 0.0074, respectively). Lack of the l/l
allele form in intron 2 most powerfully predicted non-response (83.3%). Response
to SSRI drugs is related to allelic variation in the 5-HTT gene in depressed
Korean patients.
PMID- 10683862
TI - Role of dopamine D3 receptors in thermoregulation: a reappraisal.
AB - Dopamine agonist-induced hypothermia has been proposed to be mediated by the D3
receptor (D3R), as it is elicited by (+)7-OH-DPAT and antagonized by S 14297, two
putative D3R-preferential ligands. Here we show, however, that S 14297 is a full
and partial agonist at D3R and D2R, respectively. Hypothermia was induced in rats
by agonists with potencies correlated with their D3R and D2R functional
potencies, and was reversed by antagonists, with a rank order of potency typical
of the D2R. Moreover, BP 897, a highly potent and selective but partial D3R
agonist was inactive in producing hypothermia or reversing (+)7-OH-DPAT-induced
hypothermia. (+)7-OH-DPAT was as potent and efficient in inducing hypothermia in
wild-type as in D3R-deficient mice. Hence, our results suggest that hypothermia
does not result from a selective stimulation of the D3R.
PMID- 10683863
TI - Synthesis of new derivatives of 1,2,3,4,7-pentamethylbicyclo[2.2.1]hept-2-ene-5,6
dicarboximide with an expected anxiolytic activity.
AB - The preparation of a number of derivatives of 1,2,3,4,7
pentamethylbicyclo[2.2.1]hept-2-ene-5,6-dicarboximide with potential anxiolytic
activity has been described. The aim of our study was to obtain new analogues of
tandospirone, that is derivatives of cyclic imides [1].
PMID- 10683864
TI - Synthesis of some N-substituted 3,4-pyrroledicarboximides as potential CNS
depressive agents.
AB - As a continuation of our work on N-[4-aryl(heteroaryl)piperazin-1-ylalkyl]-3,4
pyrro ledicarboximides, which were characterized by strong analgesic activity and
CNS depressive action, several novel N-substituted 3,4-pyrroledicarboximides were
prepared and eleven representatives were examined in a series of in vivo CNS
tests. A few of these compounds displayed a similar profile of biological
selectivity to that of 3,4-pyrroledicarboximides described previously; their
structure-activity relationships are discussed.
PMID- 10683865
TI - [Color reactions for identification of nalidixic acid].
AB - Nalidixic acid (1) gives with 2-naphthol a yellow charge-transfer complex. The 7
methyl group of 1 condenses with vanillin (2) and Ehrlich's reagent (4) to the
coloured (E)-benzylidene compounds 3 and 5. Treating 1 with thionyl chloride and
subsequent reaction with aminopyrazolone (6) and sodium acetate leads to a
mixture of trichloronalidixic acid (7) and its 3-carboxamide 8. The
trichloromethyl group of 7 is converted with 6 in pyridine to form the amide 9.
Nalidixic acid reacts with 1,3-dimethylbarbituric acid (10) in
acetanhydride/acetic acid to yield the polymethine dyes 11-13, whose structures
are confirmed by X-ray crystal structure analysis. The dyes 3 and 12 inhibit the
growth of staphylococcus aureus and Escherichia coli, respectively.
PMID- 10683866
TI - [Synthesis of 4,5-dihydro-1,2,4-oxadiazoles from N-unsubstituted amidoximes].
AB - 4,5-Dihydro 1,2,4-oxadiazoles can be synthesized from aromatic and araliphatic
amidoximes by cyclocondensation with aldehydes and ketones. Resulting
heterocycles differ in substitution at C-3 and C-5 showing the scope of the
simple reaction.
PMID- 10683867
TI - Synthesis and anticonvulsant activity of some amino acid derivatives. Part 3:
Derivatives of Ala, Arg, Tzl, Gly and chi Abu.
AB - Ten amino acid derivatives as antagonists of the excitatory amino acid (EAA)
receptor and anticonvulsant activity have been designed. Five of these compounds
supposed to show rather strong and five of them rather weak action as it was
expected on the base of their hydrophobicity. All the compounds were synthesized
and then evaluated in mice in the maximal electroshock seizure (MES) test, the
subcutaneous Metrasol seizure threshold (scMet) test and the rotorod
neurotoxicity (Tox) test. Four of the obtained compounds have shown high activity
(three received class I and one class II) and six were classified in class III
according to the classification of the Anticonvulsant Screening Project (ASP) of
the Antiepileptic Drug Development Program (ADDP) of NINDS. One of the compounds
classified in class I (10) was tested quantitatively following i.p.
administration in mice. It has a MES ED50 = 29.05 b.w. and protective index (PI)
of 3.77.
PMID- 10683868
TI - Synthesis of new pyrido[4',3':4,5]thieno[2,3-d]-1,2,4-triazolo[3,4-c]pyrimidines
and a 5,6-dihydro-1,2,4-triazolo[4",3":1',2']pyrido[4',3':4,5]thieno [2,3-d]
pyrimidine ring system.
AB - A series of substituted pyrido[4',3':4,5]thieno[2,3-d]-1,2,4-triazolo[3,4
c]pyrimidines 4-6, 8, pyrido[4',3':4,5]thieno[2,3-d]-1,2,4-triazolo[3,4
c]pyrimidines 11-13 and 5,6-dihydro-1,2,4
triazolo[4",3":1',2']pyrido[4',3':4,5]thieno[2,3-d] pyrimidines 16-19 have been
synthesized from 3, 10 and 15 through the reaction with orthoesters and carbon
disulphide, respectively.
PMID- 10683869
TI - [A 1-hydroxyindole-2-carboxylic acid and a 9-hydroxy-beta-carboline-4-carboxylic
acid from a nifedipine analog biscyanoethyl ester].
AB - Bis(2-cyanoethyl) 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5
dicarboxylate (3) reacts with sodium hydroxide solution to yield the 1
hydroxyindole-2-carboxylic acid 7 and the 9-hydroxy-beta-carboline-4-carboxylic
acid 13. The structures of 7 and 13 were elucidated by derivatization and by
spectroscopic methods. Bis(2-cyanoethyl) 2,6-dimethyl-4-(2-nitrosophenyl)pyridine
3,5-dicarboxylate (22) obtained by irradiation of 3 reacts with sodium hydroxide
solution to give the cyclic hydroxamic acid 23 whose structure is proven by an
independent synthesis.
PMID- 10683870
TI - Fluorescent-labeled ligands for the benzodiazepine receptor. Part 1: Synthesis
and characterization of fluorescent-labeled benzodiazepines.
AB - Because radioactive labeled ligands in receptor assays have several
disadvantages, we synthesized a number of fluorescent-labeled benzodiazepines.
Several fluorophores were attached at different positions of 1,4-benzodiazepine
molecules in order to assess the impact of the fluorophores and their coupling
position on the affinity for the benzodiazepine receptor. Besides the 1,4
benzodiazepines, the 1,2-annelated 1,4-benzodiazepines were also used for
labeling. A metabolite of flumazenil (18), desethylflumazenil (Ro15-3890, 19),
was labeled with the fluorophore 4-bromomethyl-7-methoxycoumarin, with and
without the incorporation of a spacer chain, yielding the methyl-methoxycoumarin
(Mmc) derivatives Mmc-Ro15-3890 (20a) and Mmc-O-CO-(CH2)3-Ro15-3890 (20b),
respectively. After the synthesis, the fluorescent-labeled benzodiazepines were
purified by HPLC, using an analytical RP-C18 column. For the purification of 20b,
the chromatographic system was optimized, using multi-criteria decision making
(MCDM) techniques. The binding affinities for the benzodiazepine receptor and the
fluorescence characteristics were determined for the resulting products.
PMID- 10683871
TI - Determination of tetrahydrozoline hydrochloride and fluorometholone in
pharmaceutical formulations by HPLC and derivative UV spectrophotometry.
AB - Two methods for the quantitative determination of tetrahydrozoline hydrochloride
(1) and fluorometholone (2) in pharmaceutical eye drops (Efemoline) are
described. The procedures are based on derivative UV spectrophotometry and HPLC.
In the former method, d2A/d lambda 2 values were measured in methanol at 226 and
282 nm for 1 and 2, respectively. The relative standard deviations for the method
were found to be 1.06% for 1 and 0.98% for 2. The latter method based on a
reversed phase HPLC system using a Partisil 5 ODS analytical column. The mobile
phase used for the separation of 1, 2 and internal standard (lidocaine) was
methanol/acetonitrile/water (50:50:10 v/v) and the compounds in the eye drops
were detected at 220 nm using an UV detector. The relative standard deviations
for the HPLC method were determined to be 0.61% and 0.50% for 1 and 2,
respectively. The proposed methods, which give thoroughly comparable data, are
simple, rapid, and allow precise and accurate results and could be used for
commercial formulations containing tetrahydrozoline hydrochloride and
fluorometholone in combination.
PMID- 10683872
TI - ["Non-solvent shock agglomeration technology" as a new alternative method for
work on ibuprofen. 4. Production and evaluation of quick release forms].
AB - During compaction of shock-agglomerated S(+)ibuprofen it was of interest if and
how far the sometimes strongly differing quality or the origin of the source
material has effects on the tabletting properties and on tablet quality.
Moreover, conventional and shock agglomerated substances are compared with regard
to the parameters mentioned. The technology of "non-solvent shock agglomeration"
results in substances suitable for direct tabletting. Additionally, the resulting
comprimates have characteristics which can be clearly traced back to the special
quality of the ibuprofen-shock agglomerates. By using different agents in the
process of substance preparation specific galenic properties can be achieved.
PMID- 10683873
TI - Interactions between food components and drugs. Part 8: Effect of pectins and
bile acid preparations forming stable mixed micelles on transport of quinine in
vitro.
AB - Interactions between quinine and acetylated pectin, amidated pectin and pectin
with blockwise arrangement of the free carboxyl groups as well as interactions
between quinine and bile salt preparations forming stable mixed bicelles have
been investigated. A diffusion cell with two compartments and an artificial lipid
membrane and a filter-grown colon carcinoma cell line (Caco-2) have been used.
Depending on structural parameters, pectin preparations diminished the rate of
permeation of the drug. Above the critical micelle concentration, the bile salt
preparations influence the quinine transport stronger than the pectin
preparations. The strongest inhibition of the quinine permeation showed a stable
mixed micelle preparation consisting of glycodeoxycholate, palmitic acid and
lecithin. The Caco-2 cell line appears to be not as suitable as artificial lipid
membranes to study drug transport in the presence of the bile salt preparations.
PMID- 10683874
TI - Synthesis of 1-amino-6,7,8,8a-tetrahydroacenaphthene and its effect on the
inhibition of the MAO-enzyme at the brain cortex and liver level.
AB - (+/-)-1-Amino-6,7,8,8a-tetrahydroacenaphthene was synthesized and evaluated as a
novel drug acting on the dopaminergic system. It was shown that the new compound
displays activity as MAO inhibitor.
PMID- 10683875
TI - Antitussive activity of a glucuronoxylan from Rudbeckia fulgida compared to the
potency of two polysaccharide complexes from the same herb.
AB - An alkali-extracted low-molecular glucuronoxylan and two water-extractable
polysaccharide complexes isolated from various parts of Rudbeckia fulgida were
tested for antitussive activity on mechanically induced cough in nonanaesthetized
cats. Glucuronoxylan consisted of a (1-->4)-linked beta-D-xylopyranosyl backbone
with about 18% of 4-0-methyl-D-glucuronic acid attached to 0-2 of the chain
xylose residues. The polysaccharide complexes differed from each the other
regarding the in qualitative and quantitative composition of the sugar
components. It was found that peroral administration of all the compounds led to
a significant suppression of the cough reflex without negative influence on
expectoration. Glucuronoxylan and the complex from the aerial parts of the herb
exhibited much higher antitussive activity than the complex from the roots which
did not contain any uronic acid component. Their activity (48.2% and 46.5%,
respectively) highly surpassed the activity of the complex from the roots (23.5%)
as well as that of the peripherally acting drugs dropropizine (28.3%) and
prenoxdiazine (24.7%).
PMID- 10683876
TI - A common variant of the angiotensinogen gene and the risk of coronary artery
disease in a German population.
AB - The thymidine to cytosine transition at position 704 in exon 2 of the
angiotensinogen gene leads to the amino acid substitution of threonine for
methionine (T235 variant) and is responsible for elevated plasma levels of
angiotensinogen. To examine the influence of T235 on the risk of coronary artery
disease (CAD) we genotyped 184 CAD patients, 77 controls in whom CAD was excluded
angiographically, and 155 healthy controls without signs of CAD by polymerase
chain amplification and restriction enzyme digestion. Allele frequencies for A
(wildtype) and a (mutant allele) in the total study population were 0.538 and
0.462, 0.536 and 0.464 in the healthy controls, and 0.481 and 0.519 in patients
with excluded CAD, respectively. The allele frequencies and the genotype
distribution in these groups did not show a significant difference. In
conclusion, we did not observe an association between the T235 variant of the
angiotensinogen gene and the risk of CAD.
PMID- 10683877
TI - Cytotoxicity of triterpenoid saponins. Part 2: Relationships between the
structures of glycosides of polygalacic acid and their activities against
pathogenic Candida species.
AB - Glycosides of polygalacic acid (2 beta,3 beta,16 alpha,23-tetrahydroxy-olean-12
ene-28-oic acid) is isolated from the aerial parts of Solidago virgaurea L.
subsp. virgaurea, Heteropappus altaicus (Willd.) Novopokr. and Heteropappus
biennis (Ldb.) Tamamsch. or produced by degradation of these genuine saponins
were tested against humanpathogenic strains of Candida albicans, C. glabrata, C.
krusei and C. tropicalis using a micro-dilution assay. The antifungal action can
be influenced the variation of the etherglycosidically bonded carbohydrate units
at C-3 as well as of the acylglycosidically bonded oligosaccharide at C-28 of the
aglycone.
PMID- 10683878
TI - Screening of selected plant extracts for in vitro inhibitory activity on HIV-1
reverse transcriptase (HIV-1 RT).
AB - Methanolic-aqueous extracts of 70 plants were investigated for their ability to
inhibit HIV-1 reverse transcriptase activity in vitro. Two thirds of the extracts
screened showed more than 50% inhibition. Two extracts inhibited the enzyme
completely while four exhibited more than 90% inhibition. Tannins as nonspecific
HIV-1 RT inhibitors were detected and removed from the extracts. The IC50 values
of the most potent extracts after the removal of tannins for the HIV-1 RT
inhibition are as follows: Sambucus racemosa 0.017 mg/ml and Geranium phaeum
0.067 mg/ml. Daunomycine was chosen as a standard substance in the non
radioactive immuno assay used for screening. As a result from the future
isolation and characterization of these compounds, new leading structures are
expectable.
PMID- 10683879
TI - Isolation and structure elucidation of ligustroflavone, a new apigenin
triglycoside from the leaves of Ligustrum vulgare L.
AB - A new flavone, apigenin-7-O-beta-(2",6"-di-alpha-rhamnopyranosyl)-glucopyranoside
, named ligustroflavone, was isolated from the leaves of common privet (Ligustrum
vulgare L., Oleaceae), whose popular use was well known in the Mediterranean
historical medicine and ethnomedicine as anti-inflammatory. The structures of
other five apigenin and luteolin derivates, isolated from the polar fractions of
the methanolic leaf extracts, were elucidated.
PMID- 10683880
TI - [Aphasia research and speech localization in the brain].
AB - Aphasia research has become an acknowledged branch of modern cognitive
neuropsychology research whose aim is to explore more fully the structures of
knowledge and of cerebral processes which might both be affected in patients with
aphasia. Up to the second half of this century, a model based on a specific
cerebral localisation of language processes had emerged based on brain
localisation research by Broca and Wernicke (among others). New modern
neuroimaging techniques, however, such as computed tomography and magnetic
resonance imaging (MRI), but also functional imaging modalities such as positron
emission tomography or functional MRI, have modified these concepts. It emerges
that in comprehension as well as in production of language, not only a few well
defined centres are responsible for the activity, but there is a synchronised
activity in large neuronal networks connecting various regions located both in
the cortex and in the deep subcortical structures; today, this activity can be
demonstrated best in a non-invasive and reproducible way with functional MRI.
PMID- 10683881
TI - [High-dose chemotherapy with autologous bone marrow transplantation: 11 years'
experience in Zurich].
AB - High-dose chemotherapy with autologous bone marrow or peripheral blood stem cell
transplantation has gained widespread acceptance for the treatment of certain
malignancies. Since the introduction of this therapy in 1988 we have treated 272
patients. Indications for high-dose chemotherapy were high-risk large cell
lymphoma and lymphoblastic or Burkitt lymphoma in first remission (73 patients),
non-Hodgkin's lymphoma in chemosensitive relapse (65 patients), Hodgkin's
lymphoma in relapse (52 patients), germ cell tumours with inadequate response to
chemotherapy (34 patients), multiple myeloma (29 patients), and other
malignancies (19 patients). Treatment mortality was 1.8%. The 3-year event-free
survival and overall survival for all patients were 48 and 61% respectively. High
dose chemotherapy with autologous stem cell transplantation has become a safe
procedure and is considered the treatment of choice for relapsed large cell
lymphoma, relapsed Hodgkin's disease, stage II or III multiple myeloma, and germ
cell tumours with inadequate response to cisplatin-based chemotherapy. In other
situations, including aggressive lymphoma with risk factors, acute leucaemia or
breast cancer, the superiority of high-dose over conventional chemotherapy
remains to be proven. Patients with such diseases should not receive high-dose
chemotherapy outside a controlled clinical study.
PMID- 10683882
TI - [Postpartum footdrop].
AB - We report on a rare peripartal neuropathy of the leg caused by prolonged
difficult labour. Immediately after delivery two patients complained of
unilateral footdrop and numbness in the leg. The footdrop was most probably due
to compression of the lumbosacral trunk exposed to the foetal head. This trunk
contains fibres from lumbar roots L4 and L5 and connects the lumbar with the
sacral plexus. The outcome was favourable in both patients. If subsequent
pregnancies occur, caesarean section may be indicated.
PMID- 10683883
TI - [Spontaneous bacterial peritonitis with Streptococcus constellatus in an HIV
positive patient].
AB - Liver diseases are an important cause of high morbidity and mortality in HIV
infected patients, and liver cirrhosis is the commonest cause of ascites in this
population. We describe the case of a 38-year-old HIV-positive male (CDC stage
B3, CD4 cell count 199/mm3) with a history of hepatitis C-associated liver
cirrhosis. Following pneumonia he developed spontaneous bacterial peritonitis due
to Streptococcus constellatus. Clinically noticeable was the gradually worsening
course with few symptoms, despite the initially high ascitic fluid leucocyte
count of over 11,000/microliter, but a favourable response to betalactam
antibiotics.
PMID- 10683884
TI - [Value of radiosynovectomy in rheumatology and orthopedics].
AB - For many years radiosynovectomy has proved its worth in the treatment of
inflammatory joint disease. More recently there has also been growing interest in
the use of this method for outpatient treatment. In this overview we discuss the
established and new indications. With increasing use of the method, interest
should be focused on adequate quality control. Accordingly, basic requirements
for correct performance of radiosynovectomy in clinical practice are addressed.
Our results, based on five years' experience of radiosynovectomy in outpatients,
have shown improvement of clinical symptoms in 60-70% of cases. However, success
rates of this kind require high quality standards and close cooperation with the
referring rheumatologists.
PMID- 10683885
TI - [Acute tinnitus].
PMID- 10683886
TI - [Medical discretion and data protection in medicine].
PMID- 10683887
TI - [Medical discretion in the past and today].
AB - It is based on old traditions that a physician and other medical personal have to
be diskrete about their conversation with patients as well as about diagnostic
and therapeutical measures. The roots are found in the early times when priests
were working as medical therapists. Well known are the Asclepiads in old Greece
and later on in the Roman Empire. They were priests in the tempels of the god
Asclepios and the famous Hippocrates of Cos was also an Asclepiad and
nevertheless the founder of western scientific medicine. The historian of
medicine can demonstrate a steady development of the professional discretion
observed by physicians and surgeons on different political, cultural and
scientific conditions until today.
PMID- 10683888
TI - [Data protection as a personal right. Government Agency].
AB - The sector-specific secrets are traditionally regarded as the historical
predecessors of general data protection law. The lecture demonstrates that they
are not only aimed at protecting the individual's right to self-determination of
the handling of his personal data. It also indicates that those particular
secrets are, at the same time, serving for further purposes which are of
importance in their respective sectors. The general (omnibus) data protection
statues are given attention in the light of the beginning of automated
information processing and in their role of guaranteeing the right to personal
privacy, a role which the Federal Constitutional Court underlined in its census
decision of 1983 and which became of general relevance in the course of the
further developments. In conclusion, the report particularizes that, inter alia,
statutory adaptations and amendments are necessary in order to preserve the
effects of the doctor-patient confidentiality under the conditions of modern data
processing. The examples given are comprising: health data on chip cards, health
data in networks and the electronic record of the patient.
PMID- 10683889
TI - [Medical discretion towards relatives, colleagues and the media from the
physician's point of view].
AB - Three aspects are examined more closely: discretion towards relatives, medical
colleagues and the media. Medical discretion has a long tradition and forms an
indispensable part of the medical ethos. Physicians, however, often find it
difficult to cope with the diversity of legal regulations. Legal regulations
manifest themselves in the Social Code with its different books of legislation;
in the Federal Data Protection Law; in the Federal Epidemics Law; in the Criminal
Code; in the Code of Criminal Procedure. Physician's discretion is an
indispensable prerequisite for the confidential relationship between doctor and
patient, thus enhancing the success of medical treatment. Consequently, this
discretion must never be jeopardized. First of all, it protects the patient's
privacy and personal rights. The discretion towards relatives bears different
facets which are considered more closely: these include the patient's declaration
to unconscious patients, therapeutical decisions. Medical discretion must also be
observed among fellow doctors. This is unproblematic if the patient remains
informed in the case of joint/further treatment. The following cases are
problematic: consulting in additional physicians without the patient's knowledge;
joint practices and practice networks. As far as the media are concerned, there
is no case whatsoever that would justify a patient being presented in the media
without his or her consent.
PMID- 10683890
TI - [Medical confidentiality towards family, colleagues and the media from the legal
point of view].
AB - The more medical confidentiality is endangered in a society based on the exchange
of information especially by the welfare system and a health care system relying
on the division of labour, the more it must be protected by the law of
professional rules and regulations, civil and criminal law. First of all, medical
confidentiality refers to the patient who will only confide in his doctor if he
can be sure that his secrets will be kept. The individual patients' interests
lead directly to the interests of the public health care system which demands
confidence and cannot exist without secrecy. The physician may only reveal
information if he has the patient's consent which can also be given implied. He
can be justified by a presumed consent or the balancing consideration of legally
protected values. However, a duty to disclose does not exist. The medical
confidentiality applies towards relatives, colleagues who are not consulted by
the patient and the media.
PMID- 10683891
TI - [Special problems of confidentiality in hospitals from the legal point of view].
AB - Medical confidentiality is applicable to hospitals as well. Hospital physicians
are obliged to keep medical confidentiality to those responsible for the
hospital, to relatives, other physicians, authorities, health insurance companies
and medical services. However, this does not apply if the patient gives his
consent or is presumed to give his consent or if there is a regulation of the law
which justifies the violation of medical confidentiality.
PMID- 10683892
TI - [Special problems of confidentiality in the hospital from the physician's point
of view].
AB - Professional discretion is a result of the individual rights of the patient and
the increasing right of self-determination. It is very difficult to follow these
rules because of the necessity for precise documentation, electronic
dommentation, and the medical and administrational necessities in the hospital.
How to assure the discretion in an ambulatorium, in the room with several beds?
Where to place the operation-schedules with all their details? How to assure the
discretion, when a lot of people in the hospital are involved in the therapy and
the diagnostic procedures? A lot of questions: everybody has to do his best,
keeping in mind the professional discretion as an important human right.
PMID- 10683893
TI - [Medical confidentiality towards employers,health insurance medical services and
health insurance companies from the point of view of a medical society].
AB - In the Federal Republic of Germany, the medical discretion is protected by
criminal law section 203, by section 9 of the medical professional law, and by
the state law regarding data protection. Patient's secret may only be revealed if
the patient agrees, if a law demands or allows the revelation, or if a legal good
of higher value facilitates the revelation. The employer may be informed about
the fact of sickness of an employed and about the results of an occupational
medical screening but not about diagnosis and therapy. Under specific
circumstances, the health insurance companies have the right to demand revelation
from the physician if this is legally permitted or if the patient agrees.
Certified hospitals have to reveal certain data to the insurance companies.
Medical services of health insurances have the right to demand certain data from
the physician if a health insurance company has ordered an expert witness opinion
or examination and if the revelation is necessary for this examination. If it is
suspected that there is a mismanagement about the numbers of beds occupied by
patients in a hospital, the medical service of a health insurance may examine all
patient's records related to the health insurance of interest. There exists no
legal rights or duties to reveal information to private health insurance
companies. The revelation of patient's data to such companies is most commonly
not allowed.
PMID- 10683894
TI - [Medical confidentiality towards health insurance, employment, state offices and
health insurance companies--legal guidelines].
AB - The relationship between physician and patient has become multi-dimensional due
to the inclusion of state offices, health insurance companies and other insurance
companies. Thus, the medical confidentiality has been compromised, inevitably
information will be spread into a wider circle. Nevertheless, the principle of
confidentiality should be upheld.
PMID- 10683895
TI - [Confidentiality and the refusal to give evidence].
AB - The physician's obligation to give evidence as a witness in a preliminary
investigation is in an area of conflict between the duty to tell the truth and
preservation of professional discretion. These have to be weighed in the
individual case. In opposition to the Anglo-American law, where a possible right
of the witness to refuse to give evidence is limited by the principle of "finding
the truth", the German law of criminal procedure contains far-reaching rights of
a physician and so-called professional assistants witness to refuse to give
evidence in sections 53, 53a Code of Criminal Procedure in order to protect the
professional secrecy. This privilege refers to all facts, that have become known
to the doctor or his staff and therefore it goes beyond the area of the medical
discretion in section 203 GCC, that only contains secrets, which were confined to
the doctor or which have become known to him. The witness can decide whether he
either uses his right to refuse to give evidence or gives evidence without being
released from medical confidentiality. In the second case, he risks being
punished under section 203 GCC. If a physician is considered as witness in a
procedure, the medical files are protected from attachment in section 97
subsection 1 numbers 2 and 3 Code of Criminal Procedure. In cases, where the
physician is defendant himself, he cannot refer to this protection.
PMID- 10683896
TI - [Medical confidentiality and data protection in medical research-- legal
aspects].
AB - Medical confidentiality and data protection are important for medical research.
They should not impede medical progress. Unfortunately, the German legal
situation is not easy to understand. There are different statutes which have to
be reconciled. It is necessary that by special statute the particular problems of
medical research and confidentiality as well as data protection should be
regulated.
PMID- 10683897
TI - [Data protection in medical networks for the point of view of a representative
for data protection].
AB - The processing of medical data makes great demands on the guarantee of
confidentiality, integrity and authentity. This applies to all layers of
telecommunication: networks (telecommunication law), services (law of new media)
and contents (data protection law). The use of strong encryption, data
economicalness, offer of anonymous and pseudonym services and suitable methods of
authentication are prerequisites of data medical networks which comply with data
protection demands on the side of the physicians. The patients' sensitivity
regarding their privacy has to be strengthened too.
PMID- 10683898
TI - [Data protection in medical networks from the physician's point of view (short
report)].
PMID- 10683899
TI - [Data protection in telemedicine--legal aspects].
AB - Recent developments in telemedicine have resulted in an increased flow of
personalized medicinal data and therefore caused new in calculable risks and
dangers to the right of privacy. This article discusses the particular problems
of this issue: The patient's consent must be based on sufficient information
about the intended data processing and data flow. Transmitting data into
countries outside the European Community should prevail sufficient data
protection according to the EC-Guideline. Particular attention mus be paid to the
regulations of the new German Multimedia Legislature.
PMID- 10683900
TI - [Medical aspects of telemedicine--chip cards--electronic reception and more
(short report)].
PMID- 10683901
TI - [Medical confidentiality in the former DDR].
AB - In accordance with the communist ideology of the GDR, interventions in the
private domain of citizens were made without any compunction. Notwithstanding,
Section 136 of the Penal Code of the GDR made it a punishable offence to divulge
in professional secrets. However, this regulation only simulated the right and
obligation to respect professional secrets. Organs of the state continually
disregarded medical confidentiality. Besides this, there were numerous statutory
medical notifications which were also a severe burden to the relationship of
trust between the physician and patient. The State Security Service of the GDR
also constantly infringed medical confidentiality. In "research work" carried out
at the "Juridical University" of the State Security Service, a thorough strategy
of procuring information actually protected by medical confidentiality was
ceveloped. The physician has sole responsibility in maintaining medical
confidentiality. This also applies to the period of the GDR. There are examples
of physicians resisting the State Security Service.
PMID- 10683902
TI - [Resources survey of medicinal species from genus Aralia].
AB - This paper deals with the distribution area, growing environment and medicinal
parts of 19 species and 1 variety, including 2 new species of genus Aralia. An
index for identification of these medicinal species is presented.
PMID- 10683903
TI - [Dormancy characteristic and inner inhibitory substances of fructus Schisandrae].
AB - It has been found for the first time that there is quite a number inhibitory
substances in the testa and kernel of dormant Fructus Schisandrae. Differences
have alas been found between the inhibitor extracted from the testa and that from
the kernel. The fromer is stronger in inhibiting the root elongatain of Brassica
sp, whereas the latter is stonger in inhibiting the seeds germination. The result
shows that the dormancy of Fructus Schisandrae the inhibitors contained in the
testa and kernel.
PMID- 10683904
TI - [Effect of nitrogen, phosphorus and potassium on the growth of rhizome of Coptis
chinensis Franch and its contents of berberine].
AB - It has been found out that the normal growth of Coptis chinensis is heavily
affected and both NRA in leaves and berberine contents in rhizome are very low
when seedlings are short of nitrogen, phosphorus and potassium. The plants grow
especially worse and most of them soon die off when nitrogen is short. The new
leaves are smaller both in number and size when phosphorus and potassium are
short. Few roots can grow up and easily get old in the solution short of
potassium.
PMID- 10683905
TI - [Processing technology of rhizoma Arisaematis (Pinellia pedatisecta Schott)].
AB - Using the qualitative standard of Rhizoma Arisaematis stipulated in Pharmacopoeia
and combining with the toxic reaction in experimental mice, the optimum amount of
KAl(SO4)2.12H2O for eliminating the toxic reaction of Rhizoma Arisaematis was
selected. Based on the comparison of experiments, two new technologies for
processing Rhizoma Arisaematis have been established. Pilot production shows that
these technologies are feasible for mass production.
PMID- 10683906
TI - [Preparation method of foamed aerosol for use in vagina].
AB - The extraction of medicinal materials, compatibility of liquor and prescription
of emulsion for use in vagina were observed. The result shows that through
compound extraction, removal of tannic materials, decolorization and water
precipitation, with propylene glycol and ethylene glycol as latent solvent and
using lactic acid to adjust to pH4.5, a clarified solution can be obtained, and
then with the help of Tween-spans emulisifying agent and propellant the stable
emulsion is formed.
PMID- 10683907
TI - [Quality criteria for bazhen shennongyin liquor].
AB - Radix Angelicae Sinensis, Radix Paeoniae Alba and Radix et Rhizoma Rhei in Bazhen
Shengnongyin Liquor were identified by TLC. The contents of ginsenoside Rb1 in
the preparation was determined by TLCS. Simple, accurate and reproducible, this
method could be used as the quality criteria for this preparation.
PMID- 10683908
TI - [Determination of emodin in kangnaoshuai capsules and in radix Polygoni multifori
by thin layer chromatography scanning].
AB - The content of emodin in Kangnaoshuai Capsules was determined by TLC scanning.
The method is simple and the result is accurate. The average recovery is 99.17%
and RSD is 1.14%. The content of emodin in Radix Polygoni Multiflori was also
determined by the same method. The method is useful in quality control of
products.
PMID- 10683909
TI - [Minor saponins from leaves of Panax ginseng C.A. Meyer].
AB - Five compounds were isolated from the leaves of Panax ginseng and characterized
as 20(R)-protopanaxatriol, daucosterine, ginsenoside-F2, ginsenoside-F3 and
majoroside-F4 on the basis of spectral analysis and chemical evidence. Among
them, majoroside-F4 is obtained from plant for the first time.
PMID- 10683910
TI - [Flavonoids of Cuscuta australis R. Br].
AB - Six flavonoids were isolated from the seed of Cuscuta australis and four of them
were identified as kaempferol, quercetin, astragalin and hyperoside. Hyperoside
was obtained from this plant for the first time. In comparison with the
flavonoids in C. chinensis, it is found that quercetin and its glycoside are the
main flavonoids in C. australis. This result suggests that the flavonoids can be
used to distinguish these two medicinal materials.
PMID- 10683911
TI - [Chemical constituents of Strychnos nitida G. Don].
AB - Six compounds were isolated from the root and stem of Strychnos nitida for the
first time. On the basis of chemical properties and spectral data, the compounds
were identified as beta-sitosterol, strychnine, brucine, cantieyine, lignoceric
acid and palmitic acid.
PMID- 10683912
TI - [Quantitative determination of neferine in plumula Nelumbinis by thin layer
chromatography scanning].
AB - The content of neferine in Plumula Nelumbinis wsa determined by dual-wavelength
TLC-scanning. The linear range was found to be 0.5-6.7 micrograms. The average
recovery was 100.35%. The contents of neferine in growing in Fujian, Jiangxi and
Hubei provinces Plumula Nelumbinis were found to be 0.199%, 2.46% and 2.48%
respectively.
PMID- 10683913
TI - [Screening of antiviral agents from medicinal herbs by means of Hepadnaviruses
models].
AB - The antiviral study of 21 Chinese medicinal herbs was carried out in vitro and in
vivo. The extracts of phyllanthus urinarin and polygonum cuspidatum exhibite
obvious effects on duck hepatitis B virus and human hepatitis B virus, while the
extract of Eclipta alba showed limited inhibition on HBV DAN polymerase.
PMID- 10683914
TI - [Antioxidative effect of constituents of herba Epimedii (ESPS)].
AB - Herba Epimedii is a traditional Yang invigorating Chinese herb widely used in
clinic. The experimental results have shown that ESPS obviously increases
superoxide dismutase(SOD) activity of red cells and liver in aged mice and rats,
and increases glutathione peroxidase(GSH-Px) activity of red cells in aged mice.
On the other hand, ESPS obviously helps to reduce the content of serum and liver
lipoperoxide(LPO) in aged mice and rats, as well as the content of lipofuscin(LF)
in cardiac muscle of aged mice. The results suggest that being helpful in
increasing SOD and GSH-Px activities and inhibiting the formation of LPO and LF,
ESPS may be a good antiageing agent.
PMID- 10683915
TI - [Pharmacological effects of zisu and baisu].
AB - The extract and volatile oil of zisu (Perilla frutescens) has shown significant
antipyretic effect in rabbits and antiemetic effect in pigeons. The fatty oil
extracted from its seeds has significant antitussive effect in mice and anti
asthmatic effect in guinea pigs. The extract, volatile oil and fatty oil of
Baisu, which is of the same genus as Zisu have the same effects as those of Zisu.
The acute toxicities of the extract and fatty oil of Zisu and Baisu, whether by
peroral or by intraperitoneal, are similar to each other. These results indicate
that Baisu has the same pharmacological effects as Zisu, and thus can be used as
a substitute for Zisu.
PMID- 10683916
TI - [Characterication of reference strains of L. interrogans in China by ISSP-PCR].
AB - The gene polymorphism of the DNAs extracted from reference strains of L.
interrogans in China was characterized by LSSP-PCR primered by G1 or G2, which
were a pair of specific primers for L. interrogans. The fingerprinting produced
by LSSP-PCR showed that serovar lai, serovar canicola, serovar pyrogens, serovar
autumnalis, serovar australis, serovar linhai, serovar wolffi and serovar
haemolytic have similar patterns, but serovar hebdomadis, serovar javanica,
serovar ballum, serovar pomona, serovar spaidjin, serovar tarassov and serovar
manahao I have different profiles. This result agreed with the classification of
genetic species by Yasuda. The utilization of LSSP-PCR banding patterns in the
identification of leptospries in blood samples also gained encouraging results.
Compared with the routine methods in genetic species classification, LSSP-PCR has
the advantages of rapidity, simplicity and low-cost. It appears to be a promising
tool in studying such slowly growing bacteria as leptospires. Further exploration
of LSSP-PCR in classification and identification of Leptospires is worthwhile.
PMID- 10683917
TI - [Immunogenecity of expressed protein p68 from recombinant plasmid rpDJt in L.
interrogans serovar lai].
AB - There are two types of infection caused by pathogenic microorganisms,
intracellular infection and intercellular infection. Infection of pathogenic
leptospira is an intercellular infection. The immunological reaction of host to
intercellular infection is unique. The potential immunogen of an expressed
protein should meet three criteria: it can be degraded (by antigen-present cells
in the host); it should have antigenic epitope which can be recognized by
specific antibodies and have at least one epitope that can be recognized by an
MHC II protein and T cell receptor. In this study we report the cloning of an L.
interrogans protein in plasmid rpDJt and the immunogencity of the expressed
protein derivative. A genomic library of L. interrogans serovar lai strain 017
was constructed with the plasmid vector pUC18. Recombinant plasmids, designated
pDJH2 and pDJ8 were screened from the bank. EcoRI-inserted fragment of 1. 9 kb
recombinant DNA of pDJH2 was ligated into T7 RNA polymerase/promoter vectors (pT7
7). Then they were transformed into E. coli JM109 (De3), one of subclones,
designated rpDJt was achieved. SDS-PAGE showed that the molecular weights of
expression proteins were 68 kd and 23 kd respectively, designated p68 and p23.
Purifying and isolating p68 and p23, we separated them from SDS-Polyacrylamide
gels by using Side-Strip method. After fragmenting and electroeluting, p68 and
p23 were injected into guinea pigs and rabbits. An extremely strong immune
response to p68 was obtained since an anti-p68 antibody response could be
detected to a dilution 1:524,288 (guinea pigs) and 1:262,144 (rabbits) by ELISA
while anti-P23 antibody being 1:1024 (the same to guinea pigs and rabbits). The
results of improved MTT and conA 3HTdR transformation methods showed the
activities and proliferation of Th-cells were increased in guinea pigs after p68
immunization (IL-6, 83.25 IU/ml, IL-2, 28.75 IU/ml; RPI, 2.04, SI, 65.62%)
Thlymphocyte existed in two subclasses, the Th1- and Th2-cells. A major role of
Th2-cells is to "help" B-cells differentiate, replicate, and secrete antibody.
The properties of these interactions explain why p68 makes good antigen and p23
does not. The antigens responsible for eliciting the production of protective
antibodies are not known; however, several outer membrane proteins on L.
interrogans are candidates for vaccine. Our results suggest that expresion
protein p68 from recombinants (rpDJt) may be a candidate for gene engineered
subunit vaccine for Leptospirosis.
PMID- 10683918
TI - [Characterization of immunoblots of hydrophobic outer membrane proteins
Leptospira interrogans serovar lai strain 017].
AB - Outer membrane proteins (OMP) of Leptospira interrogans serovar lai strain 017
were extracted by using Triton X-114 (TX-114). The OMP were solubilized and phase
partitioned into both the hydrophilic, aqueous phase and hydrophobic, detergent
phase. TX-114 did not solubilize the protoplasmic cylinder in intact organisms.
The protoplasmic cylinders contained a lot of protein bands and most of the TX
114 solubilized proteins partitioned into the aqueous phase, whereas only 14
protein bands entered the detergent phase with SDS-PAGE. Detergent phase proteins
were of 5 major protein bands such as 66 kd, 39 kd, 35 kd, 27 kd, and 16 kd.
Immunoblotting of the material extracted with TX-114 showed that detergent phase
proteins of alone 39 kd was apparently immunoblotting with antiserum against such
as whole cell of 017 strain the outer envelope of 017 strain and the
immunoprotective anti-017 Mb E4B7G5. The results showed that we could separate
and purify the 39 kd protein to analyse the amino acid sequence for the cloning,
expression and development of genetic engineering vaccines.
PMID- 10683919
TI - [Analysis on speciems of serum and urine in 66 cases of early leptospirosis by
PCR and biotin-AMPPD hybridization].
AB - We used polymerase chain reaction (PCR) and Biotin-AMPPD hybridization to detect
leptospiral DNA in blood and urine samples in 66 patients at the early stage of
leptospirosis. The results showed that PCR and Biotin-AMPPD hybridization not
only ruled out the non-specific PCR amplification and increased the reliability
for clinical specineus of leptospirosis but also raised the detecting sensibility
(from 71.3% to 86.1%). The positive rates of PCR resulted from serum and urine
showed no statistical difference; therefore urine sample is worthy of application
and dissemination for detecting leptospires at the early stage of leptospirosis.
Urine sample is easier for one to collect, preserve and has less intervention.
The primers G1, G2 are optimal opplication of PCR in epdemic areas in China.
PMID- 10683920
TI - [Alterations of substance P-immune reaction positive neurons of cerebral tissues
in epileptic rats].
AB - Employing the immunocytochemical analysis, we observed the alterations of
Substance P-Immune Reaction (SP-IR) positive neurons of the cerebral cortex,
hippocampus and amygdala in rats suffering from epilepsy induced by Penicillin
(PEN). The result showed that the number of neurons of epileptic group was higher
than that of the control group and no significant change in the rumber of neurons
was observed in the group in which PEN was given after injection of Nimodine. It
indicates that SP and Ca2+ participate in the process of epileptogenesis.
PMID- 10683921
TI - [Regeneration of functionally active rat brain muscarinic receptor in vitro after
inhibition with methylmercury chloride].
AB - The effect of methylmercury on muscarinic receptors and the regeneration of
functionally active muscarinic receptor in vitro by antagonists were
investigated. The result showed that methylmercury chloride (MMC) inhibited the
binding of [3H] QNB to muscarinic receptor of rat brain-lysed synaptosomes, with
IC50 values of 4.18 mmol/L. Regeneration of functionally active rat brain
muscarinic receptors after inhibition with methylmercury was achieved by 2,3
dimercapto-1-propanesulfonc acid, Na salt (DMPS) dithiothreitol (DTT),
glutathione (GSH) and Cysteine. Blocking the sulfhydryl groups is suggested to be
the molecular mechanism of inhibition of brain muscarinic receptors by
methylmercury. Our results provide evidence that thiols chelate out mercuric
cations that tightly bound to sulfhydryl groups in muscarinic receptor binding
sites and regenerate [3H] QNB binding activity.
PMID- 10683922
TI - [The effects of Tripterygium wilfordii polyglycosidium on neuromuscular junctions
of adult toad].
AB - The effects of tripterygium wilfordii polyglycosidium (TWP) on the transmission
at the neuromuscular junctions (NMJ) of sciatic nerve-sartorius muscle
preparations of 20 adult toads (Bufo bufo gargarizans) in vitro were studied by
means of intracellular microelectrode recording of endplate potentials (EPP). The
results revealed that TWP could cause changes of EPP amplitude so as to influence
the transmission at NMJ, and the effects apparently depended on the concentration
of the drug. A proper concentration of TWP could produce a significant increase
in EPP amplitude and therefore facilitate the transmission at the NMJ.
PMID- 10683923
TI - [Application of Apo B 3' DNA polymorphisms in forensic science Practice].
AB - Amp-FLP analyses of Apo B 3' VNTR locus in human blood stain, saliva (stain),
semen, mixed stain and hair have been carried out. The genotypings have been
achieved. The genotypes of Apo B 3' locus can be detected accurately in blood
stains kept at room temperature within 15 weeks and at -20 degrees C within two
years. In a series of paternity testing on 34 cases, 8 false alleged fathers were
excluded; of them, 6 were excluded by Apo B 3' locus alone or by Apo B 3' locus
combined with other genetic markers. 3 rape cases were investigated; 2 suspects
were excluded.
PMID- 10683924
TI - [The application of D1S80 locus analysis to forensic problems by using Amp-FLP
technique].
AB - This is a paper on paternity testing in 85 test cases and the identification of
individuals from mixed stains of semen and vaginal secretion in two rape cases.
We used primers flanking the hypervariable region of the D1S80 gene to amplify
DNA extracted from fresh blood, blood stain, saliva stain, semen stain, mixed
stain in vaginal swab, and from fetal tissues. The results revealed that 35 out
of 85 alleged fathers in 85 paternity testing cases were excluded. In 30 of the
35 excluded cases, the alleged fathers were excluded by D1S80 locus analysis. The
exclusion rate was 35.29%. In 2 of the excluded cases, the alleged fathers were
excluded by D1S80 locus analysis only. In 50 nonexcluded paternity testing cases,
the paternity index(PI) of D1S80 locus was 2. 0576-111.1111. It indicates that
D1S80 locus analysis plays an important role in elevation the relative chance of
paternity (RCP) value. In 41 of the 50 nonexcluded cases, RCP was higher that
99.75%. RCP reached 99.300%-99.649% in 9 of cases. In one rape and homicide case,
the genotype of D1S80 locus of sperm on the vaginal swab was detected. It gave a
clue to investigation. In the other rape case, the genotype of D1S80 of sperm on
the vaginal swab was consistent with the blood stain from the suspect. So the
suspect was not excluded. Since the D1S80 locus has a high discrimination power
it is very useful for forensic individual identification and parentage testing.
Some problems have been discussed in this paper.
PMID- 10683925
TI - [Transferrin subtyping of human semen, semen stain, vaginal fluid and mixed stain
using isoelectric focusing and immunoblotting].
AB - Transferrin (Tf) is an important genetic marker for personal identification in
forensic science. We examined the subtypes in human semen, semen stain, vaginal
fluid and mixed stain using isoelectric focusing and immunoblotting
method(IEFIB). The results showed that, Tf subtypes of 8 semen and semen stain
samples stored at room temperature for up to 32 weeks were the same as those in
sera. Tf subtypes of 17 vaginal fluid and 4 mixed stain containing few semen were
not detected. Tf Subtyping of 1 mixed stain containing enough semen was
successful by using IEFIB. These results indicate that Tf is stable in semen
stain. The Tf subtyping in semen stain and mixed stain containing enough semen
can be carried out by using IEFIB method.
PMID- 10683927
TI - [Optimazation of conditions for stereoselective reaction by enzyme-catalyzed
acetylation].
AB - Optically active endo-tricyclo-[5,2,1, 0(2,6)]deca-8-en-3,5-diol-5-acetate is a
very useful chiral synthon for the synthesis of optically active natural
products. In this paper, the optimal conditions for the synthesis of this
compound was established by orthogonality test. Under these conditions, the
chemical percentage yield of acetylation of (+) endo-tricyclo-[5,2,1,0(2,6)] deca
8-en-3,5-diol-5-acetate and its % e.e. can reach up to 81% and 98.3%
respectively. The optimazation of the conditions is efficient for the reaction of
enzyme-catalyzed esterification.
PMID- 10683926
TI - [Study of PEFV curves in 520 normal middle-aged and old humans].
AB - Partial expiratory flow-volume(PEEV) curves and other pulmonary functions were
performed for 520 (20-86 yr) normal midde-aged and old humans. The regression
equations of V at FRC (VFRC, volume corrected VFRC (VFRC/FVC), flows at various
lung volumes (V75, V50, V25) and specific time constants (S tau 75, S tau 50, S
tau 25) were built with multiple stepwise regression analysis. VFRC decreased
with increase of age, but after correction with FVC, the correlation of VFRC/FVC
with age decreased. The regressions were tested with substitution of parameters
with normal persons and proved to be correct. This study suggests that PEFV curve
with convenient method has theoretical and practical significance.
PMID- 10683928
TI - [Callus formation of Aristolochia tuberosa and determination of aristolochic acid
of callus by HPLC].
AB - Studies on the callus induction starting from the young stems of Aristolochia
tuberosa on MS medium were reported and the morphological characteristics of
cultured cells were described. The results of HPLC determination showed that some
callus cultures had higher aristolochic acid content than their original plant
organs, and the callus cultured in MS medium +2, 4-D 0.5 mg/L produced more
amounts of airstolochic acid(0.27% of dry callus weight) compared to the original
plant organ (0.15/1000 of dry weight).
PMID- 10683929
TI - [Mutagenicity and carcinogenicity of nabumetone].
AB - To study the mutagenicity and carcinogenicity of Nabumetone, we conducted Ames
test (TA97, TA98, TA100, TA102), micronucleus test(MN) in mice marrow,
chromosomal aberration assay(CA) in CHL cells in vitro, CA in germ cells from
testes of mice, and cell transformation test of Syrian hamster embryo(SHE) cells.
The maximum concentration was 500 micrograms/plate in Ames test with and without
S9 mix. The mice were treated orally(gavage) daily for 4 days in 3 doses in which
the maximum dose was 60% LD50 and sampled at the 5th day in MN. The maximum
concentration was the dose that the growth of 50% of cells was inhibited in CA of
CHL. Cells were harvested after recultured for 18 hours in fresh medium after
treatment for 6 hours in the test with S9 mix, and after treatment for 24 or 48
hours in the without S9 mix. The mice were treated orally(gavage) daily for 5
days in 3 doses in which the maximum dose was 1/4 LD50 and sampled at the 6th day
in CA of germ cells from testes of mice. 2 micrograms/ml was chosen as the
maximum concentration in the cell transformation test of SHE cells, and result
was observed after treatment for 9 days, All the tests obtained the same negative
result as that reported by other investigators.
PMID- 10683930
TI - [Antiallergic effects of tranilast in rats and guinea pigs].
AB - Tranilast is an anti-allergic drug. In this study, we made a comparision between
the Tranilast synthized by School of Pharmacy WCUMS using new technical and the
Tranilast produced by Kissei pharmaceutical Co. LTD, Japan on their antiallergic
effects. We found that the two tranilasts had the same antiallergic effects: (1)
they inhibit the passive cutaneous anaphylaxis in sensitized rats with the dose
of 100, 200 mg/kg(P < 0.01); (2) they inhibit degranulation of mast cells in
sensitized rats (10(-5) and 10(-4) mol/L) (P < 0.05); (3) they inhibit schultz
Dale response in sensitized guinea pigs (10(-3) and 10(-4) (mol/L); (4) the
inhibit SRS-A release from the lung of sensitized guinea pigs(10(-3), 10(-4) and
10(-5) mol/L) (P < 0.05); and (5) they inhibit the contraction of ileum of normal
guinea pigs induced by SRS-A(10(-4) and 10(-3) mol/L).
PMID- 10683931
TI - [Molecular cloning of the imipenem resistant gene in bacteroides fragilis].
AB - Imipenem, as a representative of-cabapenem, is one of the most effective beta
Lactam agents against Bacteroides, but recently there have been a few reports on
the resistant strains of Bacteroides. To explore the mechanism of imipenem
resistance (IMPr) at the molecular level, we extracted chromosome DNA of the
resistant strains and acquired a 1.7 kb fragment of resistant gene of imipenem.
Recombinant plasmid was stably reserved in generation after generation in E. coli
DH5. Resistant gene of imipenem was labeled with Dig-11-dUTP by way of random
prime, and 40 strains of clinically isolated Bacteroides were detected by the
prepared DNA probe. Two IMPr strains showed hybridization signal, whereas 38 IMPr
strains did not show such a signal. The result suggests that the Dig-labeled IMPr
gene probe can be used in molecular epidemiology for investigating IMPr strains.
PMID- 10683932
TI - [The responses of leukemia cells to interleukin-2 in vitro].
AB - We conducted a study on the utility and safety of rhIL-2 immunotherapy for
leukemia. The responses of leukemic cells expressing interleukin-2 receptor (IL
2R) gene obtained from 7 leukemic cell lines, 6 cases of acute lymphoblastic
leukemia (ALL) and 8 cases of acute myeloid leukemia (AML) were measured by 3H
thymidine incorproation. The results showed that the responses of these cells
were heterogeneous. The cells expressing IL-2R alpha and IL-R beta mRNAs
simultanesously from NKL-1,2 cases of ALL and 1 cases of AML(M5) responded to
rhIL-2 proliferatively; the cells from 3 leukemic cell lines, 2 cases of ALL and
2 cases of AML were inhibited by rhIL-2; the leukemic cells from the remaining 3
leukemic cell lines and 7 cases of leukemia did not respond to rhIL-2. The study
demonstrates that the responses of leukemic cells expressing IL-2 receptors to
rhIL-2 are heterogeneous. The patterns of the responses are proliferative, being
inhibited to rhIL-2, or irresponsive. So rhIL-2 immunotherapy is suitable for the
patients whose leukemic cells were inhibited by or did not respond to rhIL-2 in
vitro, but this immunotherapy is not suitable for the patients whose leukemic
cells responded proliferatively to rhIL-2 in vitro.
PMID- 10683933
TI - [Properties of adherence of erythrocytes to endothelial cells in patients with
ischemic stroke].
AB - Adherence of erythrocytes to human umbilical vein endothelial cells (HUVEC) in
patients with cerebral thrombosis and transient ischemic attack (TIA) were
quantitatively studied in the flow chamber system, compared with that in healthy
subjects. We found: (a) The adherence of erythrocytes to HUVEC in patients with
cerebral thrombosis and TIA increased, compared with that in healthy subjects;
(b) The adhesion of erythrocytes to HUVEC in patients with TIA was not
significantly different from that of patients with cerebral thrombosis. These
suggested that the increased adhesion of erythrocytes to endothelial cells might
play an important role in the pathologic process of ischemic stroke.
PMID- 10683934
TI - [Evaluation of oral glucose tolerance test in the assessment of reserved function
of liver for patients with hepatocellular carcinoma].
AB - The aim of this study was to evaluate oral glucose tolerance test(OGTT)in the
assessment of reserved function of liver for predicting the tolerability of
patients to hepatectomy and hence provided a criteria for selecting the
candidates for undergoing hepatectomy, since the majority of hepatocellular
carcinoma (HCC) patients were associated with posthepatitis cirrhosis. The
preoperative and postoperative OGTT and liver biopsy for pathological
investigation were carried out in 62 cases of hepatecomized patients and 49 cases
of unresected patients for comparison. The results revealed that the patients
whose preoperative OGTT curve was of P type recovered uneventfully after
hepatectomy, but those whose curve was of L type of tolerated poorly to
hepatectomy and were liable to postoperative hepatic failure and complications.
The severity of cirrbosis in those poor risk patients fell to C III or C IV
histological degree. 29 patients with intermediate feature of OGTT curve between
P type and L type, i.e. I type underwent regional vascular occlusion at hepatic
hilus as hepatectomy, and infusion of Danshen extract solution before vascular
occlusion to prevent hepatocytes from reperfusion injury. Of them, 20 recovered
uneventfully, 8 suffered from complications such as ascites and/or juandice, and
1 died within 1 month after operation. The followup study showed that the
survival time of patients with P type OGTT curve was longer than that of I type,
and the latter was longer than that of L type. The pattern of OGTT curve could
change from preoperative P type to postoperative L type, depending on the
severity of vascular interruption of liver and the ischemic injury to hepatocytic
mass in operation.
PMID- 10683935
TI - [Kidney lesions complicated by hypoxic ischemic encephalopathy of neonatal pig].
AB - To study the kidney lesions complicated by hypoxic ischemic encephalopathy (HIE)
in newborn, we successfully established a neonatal pig model of HIE. Changes in
brain tissue similar to those of newborn in HIE were detected after 2 hours of
hypoxia and ischemia. Meanwhile, swelling of kidneys, hemorrhage below
encapsules, swellin of tubular epithelial cells, necrosing and falling of a few
tubular epithelial cells, and narrowing of tubular lumens were observed. The
basement membranes of renal tubules remained normal serum BUN and creatinine
increased significantly after experiment compared with before (P < 0.025 and P <
0.05 respectively). The results showed that the kidney of neonatal pig was
damaged in HIE. But the injury was not severe. After 72 hours free from hypoxia,
the structure and function recovered approximately from the injury.
PMID- 10683936
TI - [Medicine S inhibits class II MHC expression of intragraft renal in rats].
AB - The Purpose of this study was to address the mechanism of medicine S which has
anti-rejection effects of renal allografts in rats. Kidney transplantations were
performed from SD to Wistar strain (allogeneic) and from Wistar to Wistar
(Isograft) using the same modified technigue described by Fabre and kamada.
Experimental rats were divided into five groups. Group I (Isograft group) and
group II (allograft group) as controls were not treated with medicine. The others
were allograft groups which received medicine S, Cyclosporine A, and low-dose
Cyclosporine combined with medicine S, respectively. Renal function and resultant
morphology changes were assessed 2, 4 weeks after transplantation. All sections
of kidney grafts were stained with monoclonal antibody class II MHC (OX6), and
then the surface densities of positive staining were quantified by computer image
analysis. The level of molecular expression in group II was significantly
increased (7.61 +/- 0.57 vs 0.51 +/- 0.2 of group I, P < 0.01). In groups I and
IV, the molecule of expression was reduced, compared with the groups II, III and
V (P < 0.05). The results suggest that medicine S decreases the level of class II
MHC expression and medicines combined with lowe-dose cyclosporine is more
effective than cyclosporine alone.
PMID- 10683937
TI - [Correlations of T lymphocyte subsets and IL-2, sIL-2R in patients with malignant
ovarian tumor].
AB - To study the relation between malignant ovarian tumor (MOT) and cell mediated
immunity, the numbers of T lymphocyte subsets and levels of IL-2 and sIL-2R were
measured simultaneously in 40 patients with MOT and 30 normal controls (NC), and
the correlations between T subsets and IL-2, T subsets and sIL-2R were analyzed.
The results were as follows: (1) The numbers of CD3+, CD4+, CD4+/CD8+ and the
levels of IL-2 in the patients were lower than those in the NC significantly, and
the opposite results were observed about CD8+ and sIL-2R (P < 0.01-0.001); (2)
There were positive correlations between CD3+, CD4+, CD4+/CD8+ and IL-2 and there
were negative correlations between CD3+, CD4+, CD4+/CD8+ and sIL-2R in MOT group
(P < 0.01-0.001). The results suggested that the T lymphocyte immune function in
MOT group was decreased. The reduced numbers of CD3+, CD4+, CD4+/CD8+ were
related to the decreased levels of IL-2 and the increased levels of sIL-2R. It
may be an important factor of incidence and development in MOT.
PMID- 10683938
TI - [Relationship of C-erbB-2 oncogene overexpression to estrogen progesterone
receptors in brease cancer and its prognostic significance].
AB - In order to understand the relationship of C-erbB-2 oncogene overexpression to ER
and PR in breast cancer and its prognostic significance, we examined
overexpression of C-erbB-2 oncogene in 106 breast carcinomas by using
immunohistochemical techniques (LSAB). The results showed that the positive rate
of C-erbB-2 overexpression was 63.21% (67/106). The overexpression of C-erbB-2
oncogene related negatively with survival. 81.63% of the cases with
overexpression of C-erbB-2 oncogene survived < or = 5 years and 34.29% survived >
10 years. There were significant associations of C-erbB-2 overexpression with
advance clinical stage, high histological grade, and positive axillary node
status in breast cancers. Negative relationship between hormone receptors and C
erbB-2 oncogene. All of these findings suggested that overexpression of C-erbB-2
oncogene might be an important prognostic factor and the detection of C-erbB-2
oncogene might be arranged as a regular pathological examination in the cases of
breast cancer.
PMID- 10683939
TI - [Effect of haemorrheological changes on acute pancreatitis].
AB - This study sought to determine the effect of the haemorrheological changes on the
pathological damage to pancreas in acute pancreatitis. 96 Wistar rats, four
months old, were allocated into three groups: group I (n = 32) received surgery
for pancreatic duct obstruction (PDO) with secretion stimulation; group II (n =
32) for PDO with high molecular dextran (DX110) injection intravenously, and
group III (n = 32) for PDO with secretion stimulation and DX110 injection
intravenously. Ten other rats were used as controls (group IV) for laparotomy
alone. The results showed that PDO with hypersecretion could induced edematous
pancreastitis and PDO with DX110 injection induced only very lightly oedema in
the pancreas which was similar to the result of PDO alone, although the
haemorrheological changes were obvious in these rats. PDO with hypersecretion and
DX110 injection induced acute necrotic pancreatitis, and the pathological lesion
in the pancrease which changed gradually from edematous to necrotic could be
observed. This result suggests that haemorrheological change may not be a
causative factor of the acute necrotic pancreatitis, but it probably could
exacerbate the damage to pancreas in acute pancreatitis and play an important
role in the transformation from edematous to necrotic pancreatitis.
PMID- 10683940
TI - [Diagnostic value of pleuro-examination with fiberoptic bronchoscope in
indefinite pleural effusions].
AB - The diagnostic value of pleuro-examination with fiberoptic bronchoscope in
indefinite pleural effusions was studied. Pleuro-examination with fiberoptic
bronchoscope has been performed in 10 cases with indefinite pleural effusions,
and its diagnostic value and complications have been observed. The results showed
that the diagnoses were confirmed in 9 of 10 patients submitted to pleuro
examination, and no severe complications were found. The results suggest that
pleuro-examination with fiberoptic bronchoscope is an effective and safe
procedure and might be performed on patients with pleural effusions when routine
examinations fail to provide a diagnosis.
PMID- 10683941
TI - [Determination of trace silver in surface water samples by flame atomic
absorption with continuous flow on-line absorption preconcentration].
AB - In a continuous flow on-line preconcentration system, trace silver was adsorbed
onto activated carbon particles packed in micro colum at pH 1, eluted with 0.3 ml
of 10 g/L Na2S2O3 solution and determined by flame atomic absorption
spectrometry. For surface water samples, 25 ml sufficed precise determination of
silver at level of microgram/L. The relative standard deviation of 10 parallel
sample determinations was 6.9%. The proposed method was successfully applied to
water samples with recoveries ranging from 93.2% to 104.6% and a throughout of 7
8 sampling/h.
PMID- 10683942
TI - [A simple and rapid method of preparing cell or tissue embedded in situ for
transmission electron microscopy].
AB - A simple and rapid method of preparing cell or tissue embedded in situ for
transmission electron microscopy (TEM) is recommended. It is very simple; all
procedures, including fixation, dehydration, infiltration and embedding, are
performed on the same carrier (culture vase or microscope slides). It is also
very rapid; the whole process takes only five hours. The entire cell or tissue
embedded in situ is easily separated from the carrier. The ultrastructures of the
cell or tissue embedded in situ are well preserved with minimal damage. This
method can be used in preparing cultured monolayer cell for TEM study, paraffin
section for electron microscopic diagnosis, and frozen section for TEM
immunohistochemistry or enzymehistochemistry. The main points of the procedures
of preparation have been discussed.
PMID- 10683943
TI - [The compressive strength, tensile strength, flexural strength and micro-hardness
of Plat-II Castable Ceramics].
AB - In preparation for the clinical use of Plat-II Castable Ceramics (PCC-II), we
tested its compressive strength, tensile strength, flexural strength and
microhardness. The flexural strength was tested by the three-point bending test.
The result showed that the compressive strength was 541.7 MPa; the tensile
strength 42.5 MPa; the flexural strength 142.0 MPa; the modulus of elasticity
61.4 GPa; and the micro-hardness 499.6 kg/mm3. The strength anol micro-hardness
of PCC-II materials were better than those of human enamel. So PCC-II is
applicable to restorations in dentistry.
PMID- 10683944
TI - [The immune response in rats immunized systemically by the surface protein
antigen P1 from streptococcus mutans conjugated with procholeragenoid].
AB - This study was carried out to observe the antibody responses in rats after they
were immunized with the surface protein P1 of streptococcus mutans when a special
adjuvant was used. Antigen P1 was conjugated covalently with procholeragenoid
(PCG), and then Sprague Dawley rats were immunized with P1 or the conjugated
antigen P1-PCG subcutaneously or intragastrically. Anti-P1 antibody level was
assayed at different time points by ELISA. The results showed that the levels of
anti-P1 SIgA antibody in saliva rose when P1-PCG was given subcutaneously or
intragastrically; the antibody level following the subcutaneous injection was
higher and lasted longer, compared with that following the intragastric
administretion. The level of anti-P1 IgG antibody in serum only rose when the
rats were immunized subcutaneously. These results implied that mucosal immune
response or humoral immune response could be induced subcutaneously when PCG was
used as an adjuvant.
PMID- 10683945
TI - [The influence of porcelain thickness and non-uniformity on porcelain cracks in
implant-supported metal-porcelain fixed bridge].
AB - This experiment studied the influence of porcelain thickness and non-uniformity
on porcelain crack in implant-supported metal-porcelain fixed bridge. The result
indicated that porcelain crack began to appear when the body porcelain powder was
3-5 mm in thickness; more cracks took place when the powder thickness increased
by 1 mm to 2 mm on the axial surface in the axial direction; cracks became
serious when the thickness suddenly changed to zero; and connectors were liable
to cracks. Therefore, in designing and fabrication, one should avoid and sudden
change in the shapes of the connector and the porcelain on it, any sudden change
in the thickness of porcelain and a thickness of porcelain powder not less than
3.5 mm. Other-wise, it is neccessary to use internal crown between metal base and
abutment to meet the demands.
PMID- 10683946
TI - [Change of serum lipid, apolipoprotein during cholesterol gallstone formation in
rabbit model].
AB - In order to study the formation of cholesterol gallstone through rabbit model
which was induced by high cholesterol diet (HCD), we investigated the rabbits'
serum lipoprotein cholesterols and apolipoprotein (apo) at 1 week (1w), 2 weeks
(2w), 3 weeks (3w) and 4 weeks (4w) in comparison with those of a control group
respectively. The results were as follows: (1) of 10 rabbits subjected to
experiment, 4, 6, and 7 rabbits were found to have induced-cholesterol gallstones
in the 2w, 3w and 4w groups respectively. (2) The serum concentrations of total
cholesterol (TC), triglyceride (TG), phospholipid (PL), low density lipoprotein
cholesterol (LDL-C) and very low density lipoprotein chloesterol (VLDL) increased
significantly (1w, 2w, 3w and 4w groups vs control group, P < 0.05), especially
in the 3w and 4w groups; the surum concentrations of high density lipoprotein
cholesterol and its subfractions (HDL-C, HDL2-C, HDL3-C) decreased slightly (vs
control group, P > 0.05). (3) The serum contents of apoB100, apoC II and apoC III
increased significantly (vs control group, P < 0.05), especially in the 3w and 4w
groups; the serum apoA I reduced gradually in 1w, 2w and 3w groups, and decreased
greatly in 4w group (vs control group, P < 0.05). The results demonstrated that
owing to the intake of high cholestrol diet with the passage of time, the
increased concentrations of serum VLDL-C, apoB, apoC II and apoC III possibly
caused an enhanced secretion of biliary cholesterol into bile; that the decreased
serum apoA I level might reduce the secretion of anti-nucleating factor into
bile. All of these factors and changes may play important roles during the
formation of cholesterol gallstones.
PMID- 10683947
TI - [Penetration of ciprofloxacin and cefoperazone into human pancreas].
AB - Major pancreatic infection is responsible for more than 80% of deaths in patients
with acute pancreatitis. Therefore, the role of antimicrobial drugs in the
prevention and treatment of secondary parcreatic infection is very important. The
choice of antimicrobial drugs must be based upon the ability of the drug to
exceed the therapeutic concentration in pancreas for the common pathogens. The
penetration of ciprofloxacin and cefoperazone into pancreas was investigated in
ten patients who had undergone pancreatoduodenectomy. The pancreatic juice was
temporarily diverted to the exterior via a panoreatic duct catheter. The
pancreatic tissue was obtained intraoperatively and pancreatic juice was drained
postoperatively. The antimicrobial drug concentrations were determined by high
performance liquid chromatography. The concentrations of ciprofloxacin and
cefoperazone in pancreatic juice were 44% and 17%, respectively, of those in
serum, and exceeded the in vitro concentration (MIC-90) for most bacteria
associated with pancreatic infections. The result indicates that ciprofloxacin
and cefoprazone appear to be appropriate for both prophylaxis and therapy of
secondary pancreatic infections.
PMID- 10683948
TI - [Detection of the level of serum antigen recognized by McAbGB2 in breast cancer].
AB - This study sought to verify the levels of serum antigen recognized by McAbGB2
(abbr. serum McAbGB2 antigen) in patients with breast cancer. We adopted the
ELISA method and used McAbGB2 to detect the level of serum McAbGB2 antigen in 50
normal persons and 60 patients with breast cancer. The results showed that the
level of serum McAbGB2 antigen of 17 preoperative patients with breast cancer was
significantly different from that of the normal persons (P < 0.001); the rate of
agreement on positivity for the 17 preoperative patients with breast cancer was
88.2% (15/17); the levels of serum McAbGB2 antigen in 8 patients among the 17
preoperative patients with breast cancer decreased from 57.5 +/- 51.3 u/ml
(preoperation) to 20.6 +/- 4.98 u/ml (postoperation; the levels of serum McAbGB2
antigen in the other 43 operated patients with breast cancer almost remained
normal during post-operative chemotherapy. These suggest that serum McAbGB2
antigen is a marker for breast cancer and can be used for serological diagnosis,
treatment and prognosis inspection.
PMID- 10683949
TI - [Investigation of C1R gene frequencies in three Han populations in China].
AB - To reveal the C1R polymorphism in Chinese, three Han populations in Guangzhou
(101 samples), Jilin (105 samples) and Chengdu (111 samples) were investigated
with a technique using PAGIF followed by immunoblotting. The results showed in
Chengdu the C1R * 1 = 0.5676, C1R * 2 = 0.3424 and C1R * 5 = 0.0856, in Guangzhou
C1R * 1 = 0.5248, C1R * 2 = 0.2663 and C1R * 5 = 0.1089, and in Jilin C1R * 1 =
0.5381, C1R * 2 = 0.2619 and C1R * 5 = 0.1714. Three rare genes C1R * 6, C1R * 7
and C1R * 8 were found in the investigation. These indicate that the frequency of
C1R * 2 is elevated from north to south which may imply a geographic cline in
this locus. The cumulated heterogeneity of C1R in Han population is 61.5% which
means that this polymorphic system is useful in anthropolgy as well as in
forensic science.
PMID- 10683950
TI - [p53 gene mutations in BALB/c 3T3 cells transformed by crocidolite].
AB - This study sought to address the relationship between crocidolite and p53 gene
mutation. The mutations of p53 gene in 8 BALB/c 3T3 cell lines transformed by
crocidolite were analysed. Altogether 11 exons of the gene from 8 cell lines were
detected by PCR-SSCP. 7 alterations were found; 2 of them were located in exon 4
6, and 5 in 9-11. Most of the mutations (5/7) were of one more band than that of
wild cell from SSCP, and alterations were randomly scattered among the
crocidolite doses groups. The results suggest that the presence of a p53
alteration is not related to the dose of crocidolite used. Besides, p53 mutation
may occur in a relatively later period of the growth of the transformed cell
lines. The results also showed that the mutations occurred predominantly in exons
9-11. This was different from that seen in human mesothelioma where mutations in
the exon 5-8 of p53 gene were more frequently observed.
PMID- 10683951
TI - [Expression of vasoactive intestinal peptide receptor in human colonic carcinoma
cell membranes].
AB - To evaluate the expression of vasoactive intestinal peptide receptor in colonic
carcinoma cell membranes in men and to assess the relationship between the
receptor characteristics and the histopathologic features, the authors labelled
vasoactive intestinal peptide and measured vasoactive intestinal peptide receptor
sites with radio-ligand bind assay on 12 specimens from colon cancer and its
adjacent normal tissues. The number of the vasoactive intestinal peptide receptor
sites of colon cancer was significantly smaller than that of the adjacent normal
tissues (2.66 +/- 3.84 pmol/mg versus 10.54 +/- 17.99 pmol/mg, and the number of
the receptor sites of colon cancer was not well related to the degrees of cancer
differentiation. This study has laid the basis for the regulation of the receptor
ligand binding to inhibit the growth of colon cancer.
PMID- 10683952
TI - [Antiepileptic effects of nimodipine on penicillin-induced seizures in rats].
AB - Injecting penicillin (PNC) intraperitoneally in Wistar rats, we observed their
epileptic behaviour and electroencephalographys. The results showed that
nimodipine (NIM), a calcium antagonist, could inhibit the seizures and epileptic
discharges significantly. No epileptic action was noted while NIM was injected
before PNC. It supports our consideration of NIM as a new sort of nonsedative
anticonvulsant in clinical practice.
PMID- 10683953
TI - [Effect of tetrandrine on pulmonary vascular morphology in rats with hypoxia
pulmonary hypertension].
AB - To investigate the effect of Tetrandrine on pulmonary vascular morphology in rats
with hypoxia pulmonary hypertension. We established the model of hypoxia
pulmonary hypertension and observed the small pulmonary arterial morphologic
changes under light microscope and electron microscope after the rats were
treated with Tetrandrine; also, we made morphometric analysis. The results showed
that the small pulmonary arteria in rats with hypoxia pulmonary hypertension was
thinner than normal ones and had proliferation of smooth muscular cells.
Morphometry displayed that the external diameter became smaller and that the
ratio of vascular wall thickness to external diameter (M/T%) and the ratio of
vascular wall area to total area (MA%) increased. The pathologic change
significantly decreased after the rats were treated with Tetrandrine, indicating
that Tetrandrine inhibited hypoxia-induced thickening and muscularization of
small pulmonary arteria by inhibiting the proliferation of collagenous fibers so
that narrowing of small pulmonary arteria was significantly slackened and
pulmonary hypertension was alleviated. Therefore, we conclude that tetrandrine
may partly prevent the development of pulmonary hypertension.
PMID- 10683954
TI - [The changes of glutamate receptor and free Ca2+i in hypoxic-ischemic cerebral
injury: experimental study].
AB - This experiment was designed to explore the pathogenesis in hypoxic-ischemic
encephalopathy (HIE). Sixteen newborn pigs were divided into two groups: (Group
A) normal control and (Group B) HIE 24 hours. The glutamate receptor (Glu R) in
forebrain crude synaptic membrane (SPM) and free Ca2+i in RBC were tested
respectively. The results revealed that the binding sites (Bmax) of Glu R in
Group B was much lower than that in Group A, but the affinity (Kd) showed no
statistic difference between Group A and Group B. In addition, free Ca2+i of RBC
in Group B was much higher than that in Group A. This study demonstrates that the
changes of Glu R and Ca2+i are involved in the pathogenesis of hypoxic-ischemic
cerebral injury in newborn animals.
PMID- 10683955
TI - [Identification of the anti-rIL-1ra McAb].
AB - Using dot-immuno-blot and Western blotting techniques, we have identified the
specificity of anti-rIL-1ra McAbs. The results showed that the anti-rIL-1ra McAb
2E4 specifically reacted with rIL-1ra, from which the recognizing signal of dot
immunoblot was significantly positive (+2) and a single rIL-1ra protein band (20
kd) was clearly recognized by Western blotting. The control results of PcAb
recognization have further proved the high sensitivity of Western blotting and
high specificity of rIL-1ra McAb 2E4. The successful identification of rIL-1ra
McAb 2E4 will be helpful to further understand the biologic effects, especially
the pro-inflammatory properties, to study the change of rIL-1ra level during
inflammation, and to instruct the clinical use of rIL-1ra.
PMID- 10683956
TI - [Bone histomorphometric changes in ovariectomized goat at different time
courses].
AB - Using histopatholoical method, we investigated the bone histomorphometric changes
in ovariectomied goats at different time courses. Eight goats, female, aged one
and a half years, were randomly divided into two groups, the control and the
ovariectomy (OVX). Iliac crest biopsies were separately processed before
ovariectomy and at 60 days, 120 days and 180 days after ovariectomy. The
histomorphometric changes were observed. It was found that the bone structure in
trabecular bone remained relatively constant in the control group throughout the
whole study. In contrast, the trabecular quantity was slightly decreased and the
trabeculae were disconnected in OVX at 60 days after ovariectomy. The bone
structure was characterized by the thinning of the trabeculae, the further
discontinuance and quantity loss of trabeculae, and the anlargement of marrow
cavity at 120 days to 180 days after ovariectomy. Apparently, these bone
structural changes manifested with typical osteopenia pathological changes. Our
results may serve as a basis for the design of further studies using OVX goat as
an animal model for postmenopausal osteoporosis.
PMID- 10683957
TI - [Circadian variations of plasma SOD and MDA in health subjects].
AB - Oxygen derived free radical system has been to be implicated in the pathogenesis
of many diseases, such as cardiovascular disease, tumor, trauma and radiation
injury. Many studies have suggested that oxygen free radical initiate a series of
events that result in cell membrane alterations leading to the development of
cell injury. The objective of the present study was to examine the circadian
characteristics of some parameters of this system in the blood. One parameter was
superoxide dismutase (SOD), a major oxygen free radical scavenger; the other was
malondialdehyde (MDA), an important product of lipid peroxidation initiated by
oxygen free radicals. Blood samples were collected at 6 h intervals beginning at
08:00 over a 24 h span in nine healthy volunteers (5 females, 4 males, average
age 30 +/- 5 years). All participants were synchronized for one week with diurnal
activity from 07:00 to 23:00 and nocturnal rest, with three meals served at
07:30, 12:00 and 19:00. Plasma SOD, MDA levels were measured by pyrogallol
autoxidation assay, thiobarbituric acid spectrophotometry respectively, and the
data were fitted with a 24 h cosine curve and analyzed further by a population
mean cosinor. The results showed that the plasma SOD levels exhibited a highly
significant circadian rhythm (P < 0.001) in healthy subjects, with acrophase
(phi) at 21:17, mesor (M) of 3975.3 +/- 680.5 u/g Hb, and amplitude (A) of 273.62
u/g Hb. A circadian rhythm of plasma MDA was also detected (P < 0.01), phi =
15:15, M = 4.23 +/- 0.86 mumol/L, A = 2.37 mumol/L). The evaluation of circadian
natures of SOD and MDA may be important in the prevention, diagnosis and
treatment of associated diseases.
PMID- 10683958
TI - [A study on P16 and P53 protein expressions in ovarian serous
cystadenocarcinoma].
AB - An immunohistochemical method utilizing avidin-biontin complex (ABC) technique
was used in this study to detect P16 and P53 protein expressions in 40 ovarian
serous cystadenocarcinomas and 10 serous cystadenomas. The results showed that
the total positive rates of P16 and P53 protein were 40% and 60% respectively.
The positive staining rate was higher in P53 protein expression than in P16
protein expression in the same cases. The positive staining rates of P16 protein
were 16.67%, 33.33% and 52.63% respectively in stages I, II and III. There was no
significant difference in histological grading. The postive staining rate of P53
protein expression in poorly differentiated tumor was higher than that in well
differentiated group (P < 0.05). These results suggested that P16 and P53 protein
expressions of the ovarian serous cystadenocarcinoma might be correlated with
human organs, histological type of tumor, cyclin and cyclindependent kinase.
PMID- 10683960
TI - [Observation of the serum acidic isoferritin levels in patients with
hepatocellular carcinoma].
AB - The levels of serum acidic isoferritin (SAIF) in 48 patients with hepatocellular
carcinoma (HCC), 30 patients with hepatitis, 28 patients with liver cirrihosis,
and 33 healthy subjects were measured by using enzyme-linked immunosorbent assay
(ELISA--double-determinant). The result revealed that the SAIF values of HCC, HP
and LC did not show normal distribution. The median values were 440 micrograms/L,
21 micrograms/L, 120 micrograms/L and, in normal subjects, 66 micrograms/L
respectively. There were statistically significant differences between HCC and
the control groups. The sensitivity of SAIF to HCC was 85.46%, with the cut-off
point being 250 micrograms/L. SAIF was not correlated to AFP in HCC cases. The
values of SAIF had no relationship with the volume of the tumors and the clinical
stages. SAIF may be an available and useful serum marker and be beneficial to the
diagnosis of early-staged HCC.
PMID- 10683959
TI - [P53 protein expression in malignant germ cell tumor of ovary and its
relationship with clinical course and prognosis].
AB - To study the relationship of P53 protein expression with clinical course and
prognosis in malignant germ cell tumor of ovary P53 protein expression was
examined by immunohistochemical ABC methods in 82 cases of the neoplasm and 20
cases of normal ovary tissue. The results showed that no expression of P53
protein was detected in normal ovarian tissue. The total expression rate of P53
protein was 24.39% in neoplasm, and the expression was not significantly
correlated with the different histological types of neoplasm. The study however
found that the protein expression of p53 gene was significantly correlated with
the clinical stages and prognosis of the neoplasm.
PMID- 10683961
TI - [Analysis of the mechanism on the formation of configuration of F-V curves with
tangent time constant in adult humans].
AB - The tangent time constants at high, mid, low lung volumes (tau t75, tau t50, tau
t25) were measured from F-V curves of 258 normal adults aged 20-49. The
configurations of F-V curves were classified into the plateau, linear, convex and
concave types. In terms of distribution ratio, the convex type increased with
age, but the concave type decreased with age. The top of F-V curve was chiefly
determined by the length of magnitude of tau t75. The magnitude of tau t75 was
the longest for the concave type; its top fell down slowly with the formation of
a blant round shape. The magnitude of tau t75 of convex type was the shortest;
its top fell down rapidly and formed a peak shape. The mid portion of the curve
was determined by the length of tau t50 and the height of V50. The tau t50 was
longer and V50 was higher in the plateau and concave types, so that the mid
portion fell down slowly to form a plateau or to be concave to the volume axis.
While tau t50 was shorter and V50 was lower in the convex and linear types, the
mid portion became convex to the volume axis or formed a linear shape. The
configuration of the tail was determined by tau t25 and V25. The long tau t25 and
high V25 in the plateou type implied the extension of plateau to the low lung
volumes. While tau t25 in theother 3 types was shorter. However, V25 was higher
in the concave type, thus it made the tail fall down fast and become concave to
the volume axis. The V25 was lower in the convex type with the tail convex to the
volume axis. The height of V25 in the linear type was between the concave and
convex ones with the tail falling in a linear fashion.
PMID- 10683962
TI - [Measurement and clinical significance of inspiratory drive efficacy in patients
with chronic obstructive pulmonary disease].
AB - To study the relationship between VT/P0.1 and the function of inspiratory
muscles, we performed the measurement of VT/P0.1 (inspiratory drive efficacy),
MIP (maximal inspiratory mouth pressure) and MMIF (maximal midinspiratory flow)
in 15 normal subjects and 60 patients with chronic obstructive pulmonary
disease(COPD). The results indicated that VT/P0.1 decreased with the
deterioration of COPD and it correlated highly and positively with MIP and MMIF.
These suggest that VT/P0.1 can reflect the function of inspiratory muscles as
well as MIP and MMIF can.
PMID- 10683963
TI - [The value of erythromycin pleurodesis in the treatment of malignant pleural
effusions].
AB - Malignant pleural effusion is a frequent complication of patients with advanced
malignant tumors. For many patients suffering from malignant pleural effusion
that increases rapidly and may be life threatening, it is important to control
the effusions. To investigate the value of erythromycin as a pleural sclerosant,
a dose of 1 g erythromycin in 30 ml of 5% glucose was injected into the pleural
cavity of 26 patients with malignant pleural effusion. The results were assessed
by Miller's standards. After treatment, numerous adhesions were present in 15
cases; Pleural effusion reduced in 7 patients, and no effect was noted in 4
patients. The total response rate was 84.6%, and there were no severe side
effects. The erythromycin-induced pleurodesis is probably the result of induced
chemical inflammation in the locality. This study suggests that erythromycin is a
useful pleural sclerosant.
PMID- 10683964
TI - [Observation on the changes of lipid peroxidation in neonates with sclerema].
AB - Thirty-six hospitalized newborn infants with sclerema (case group), which were
divided into mild group(n = 18) and severe group(n = 18), and 28 normal neonates
(normal control group) were selected to measure the changes of blood lipid
peroxidation (LPO) and superoxide dismutase(SOD) so as to study the role of free
radicals and lipid peroxide injury the pathogenesis of the entity. The results
showed that the plasma LPO contents were significantly increased and SOD were
significantly decreased in the case group when compared with those in the normal
group (P < 0.01). The plasma LPO was significantly higher and SOD activity was
significantly lower in the severe group than those in the mild group (P < 0.01).
The study indicates that the free radicals produced in sclerema neonatorum are
great in amount and suggests that free radicals possibly participate in the
pathogenesis of the disease.
PMID- 10683965
TI - [Analysis and prevention of road traffic fatalities in Sichuan Province].
AB - This is an epidemiological survey of the fatalities from road traffic accidents
in Sichuan. All fatal accidents that occurred in Sichuan from January 1994 to
December 1994 were analysed. The mortalities per million kilometers of vehicle
travel, per 100,000 registered motor vehicles and per 100,000 resident population
were 4.35, 42.41 and 3.92 respectively. These figures were compared with
international death rates and those reported by other countries. The results
showed that Sichuan had higher mortalities per million kilometers of vehicle
travel and per 100,000 registered vehicles but lower mortality per 100,000
resident population, compared with some industrialized and rich develeping
countries. The majority of the victims were males aged 21 to 40. Road traffic
fatalities constituted the leading cause of all accident deaths. The cost of road
accidents in Sichuan was estimated to be sixty million Yuan. Further strategies
and methods to minimize the rate of such accidents have been suggested.
PMID- 10683966
TI - [Improved MTT colorimetric assay for serum TNF activity].
AB - The activity of serum tumor necrosis factor(TNF) is known to be related with the
mechanism and prognosis of many diseases. The aim of this experiment was to look
for an economic and reliable method for assaying the activity of serum TNF. We
used the neutrophil solventor 20% SDS-50% DMF instead of the acidity solventor
0.04 mol/l acidified isopropy alcohol and established an improved 3-(4,5-dimethyl
thiazoly)2,5-diphenyl-tetrazolium bromide (MTT) colorimetric assay for measuring
the amount and function of living cell. We used this improved MTT colorimetric
assay for measuring TNF activity of peripheral blood serum of healthy persons. It
avoided the deposition of the protein in serum and medium and showed more
repeatability, as compared with the conventional MTT colorimetric assay. The
results showed: when the activity of target cell(TC)-L929 is > or = 95%, the
density of TC is > or = 1 x 10(2)/well and the number of living cells in each
well is positively correlated with the OD volume (OD570nm-OD630nm of purple
formazan metabolite of MTT solution(r = 0.87, P < 0.01); when the density of TC
is 5 x 10(4)/well, the level standard of TNF in each well is negatively
correlated with the OD volume (OD570nm-OD630nm)r = 0.79, P < 0.01). Using this
method, we measured the TNF activity of 20 healthy persons' peripheral blood
serum. The mean +/- s of TNF activity is 20.95 +/- 3.2 IU/ml. This method is
dependable, easy-to-do and economic, it has good repeatability within 3-12 hours.
PMID- 10683967
TI - [Preparation of chromosomal DNA from whole blood without use of phenol].
AB - We describe in this paper a simple and efficient procedure for preparing
peripheral blood DNA without pre-isolation of white blood cells. The method also
avoids the hazard of organic solvent extraction. Routinely it yields 20 to 28
micrograms of chromosomal DNA from per ml whole blood. The A260/A280 ratio for
DNA sample is 1.80 to 1.85. The undigested DNAs migrate above the 21 kb pair,
while the endonucleasedigested samples appear characteristically in the smear
form. These data illustrate the consistency and quality of the chromosomal DNA
isolated using this procedure. The DNA prepared by this method was used for
analysis of beta-thalassemia mutation and prenatal diagnosis in our laboratory.
PMID- 10683968
TI - [Quantitative determination of dracorhodin in Daemonorops draco B1. and
traditional Chinese medicines containing Daemonorops draco B1. by HPLC].
AB - A reversed phase high performance liquid chromatographic mertod for the
determination of Dracorhodin in Daemonorops draco B1. and Traditional Chinese
Medicines containing Daemonorops draco B1. has been developed so as to set the
quality standard for Sichuan Jinyao. The result showed that the components of
Dracorhodin were separated by ODS column, with MeOH-0.05 mol/L NaH2PO4 (51:50)
(pH = 3.10-3.15, adjusted with H2PO4) acting as the mobile phase. The other high
retentive components were eluted by methanol; thus the analytical time was
reduced. The method is simple and accurate.
PMID- 10683969
TI - [Cloning and expression of leptospiral protective antigen gene OmpL1 in BCG].
AB - This study was intended to produce a new living vaccine against leptospirosis
using BCG as vector. Leptospiral outer envelop antigen gene OmpL1 was amplified
from the genome of pathogenic leptopira serova Lai 017 by PCR, and cloned in E.
coli-BCG shuttle plasmid pY6002. Recombinant plasmids were isolated by dot
blotting with Digoxigeninlabeled OmpL1 gene. After transforming the recombinant
plasmids in BCG (Shanghai strain) by electroporation, the genomic DNA of all 21
transformants were prepared and hybridized with OmpL1. It showed that 6 of the 21
transformants were recombinants in which the OmpL1 gene had been integrated into
the genome of BCG. By immunoblotting with OmpL1 infected rabbit antiserum, which
was preabsorbed to remove antibody against E. coli and SPA-HRP, three
recombinants, pLI1, pLI2 and pLI3, were detected to express OmpL1 protein. The
ability of expression is in the order of pLI2 > pLI1 >> plI3. These studies
provide the possibility of further research on the development of highly
efficient recombinant vaccines against leptospirosis.
PMID- 10683970
TI - [Relationship between the expression level of alpha-MHC gene and cardiac
contractility during heart failure].
AB - To investigate the molecular basis of the decrease in myocardial contractility
during heart failure, an animan model of heart failure was set up by means of
deoxycorticosterone-acetate impregnated silicone rubber implants in wistar rats.
Cardiac contractility in normal and heart failure rats was examined, and gene
expression of its myocardial contractile protein, alpha-MHC, was quantitatively
analyzed at gene transcription level by using RNA slot blot hybridization. The
results showed that the cardiac contractility and the alpha-MHC mRNA levels in
heart failure rats were all lower than those in the normal. Statistical analysis
showed a positive correlation between the cardiac contractility and the gene
expression of alpha-MHC (r = 0.4143, n = 43, P < 0.05). The above results
indicate that gene expression level of alpha-MHC is one of the key factors
determining cardiac contractility.
PMID- 10683971
TI - [Study on the beta-lactamases of the Escherichia coli HX88108 resistant to
ceforperazon].
AB - E. coli HX88108 was isolated from a patient and found to produce plasmid-encode
beta-lactamases with conferring highly resistance to ceforperazone(CPZ). The beta
lactamases of the E. coli HX88108 and transformants pFC, pFT1, pFT2 and pFT3 were
studied. The beta-lactamases stability test among 11 beta-lactam antibiotics
showed that beta-lactamases from E. coli HX88108. pFC, pFT1, readily hydrolyzed
penicillins, the first, second-generation cephalosporins and CPZ. beta-lactamases
of pFT2 and pFT3 hydrolyzed penicillins more strongly than cephalosporins. On the
other hand, experiments of inhibiting enzyme were carried out. The results
indicated that beta-lactamases of HX88108, pTF1, pFT2 and pFT3 were inhibited by
clavulanic acid(CA) and sulbactam (SBT). Enzyme of pFC was inhibited poorly by CA
and SBT. Through isoelectric focusing technique, the PIs were as follows: HX88108
contained three beta-lactamases, of which the PIs were 5.25, 5.3 and 5.6
respectively; the PIs of beta-lactamases from pFT2, pFT3, were 5.3 and 5.6. pFC
and pFT1 were different plasmids encoded beta-lactamases with the same PI 5.25.
The results indicate that the beta-lactamases of E. coli HX88108 may be a new
member in TEM farmily.
PMID- 10683972
TI - [Reversal of cancer multidrug resistance by Chinese medicine Ams-11, Fw-13 and
Tul-17].
AB - The aim of this project was to find some kinds of Chinese materia medica as
effective agents for in vitro reversal of cancer multidrug resistance. Based on
the present authors' previous researches, thirty-two kinds of Chinese medicine as
research meterials were selected and examined. Using cell growth inhibit assay,
the authors found that three of them--Ams-11, Fw-13 and Tul-17 in the doses free
from cytotoxity could enhance the sensitivity of multidrug resistant cells to
anti-cancer drugs in a dose-dependent way. It seemed that these three kinds of
Chinese medicine might be potential effective reversal agents.
PMID- 10683973
TI - [Study on telomeric association in nasopharyngeal carcinoma].
AB - The chromosomal telomeric association in peripheral blood lymphocytes from 25
untreated patients with nasopharyngeal carcinoma (NPC) and in NPC cell lines
(CNE) was investigated by using chromosome G banding technique. The cell
telomeric association rate of patients (35.07%) was found to be higher than that
of controls(20.27%) (P < 0.01), while in the two groups the distributions of
chromosomes involved were approximately the same (P > 0.05). The telomeric
association rates of patients were significantly higher than those of control in
chromosomes 1, 2, 3, 4, 7, 11, 15, and 17(P < 0.05). In NPC lines (CNE), 94% of
the cell division phases showed telomeric association. Chromosomes 2, 3, 5, 11
and 16 had higher frequencies of association than other chromosomes. The most
frequent telomeric association was single chromatid association.
PMID- 10683974
TI - [Isolation of antibacterial polypeptides of human cervical mucus].
AB - The acid-soluble extract of human cervical mucus was obtained by solving mucus
with 5% acetic acid in the presence of protease inhibitor. The antibacterial
activity of the acid-soluble extract was analyzed by gel overlay technique. The
result showed that two protein bands which were designated human cervical protein
1 (Hcp-1), human cervical protein-2(Hcp-2) were potently antibacterial against E.
coli 25922 and S. aureus 25923. Tricine-SDS-PAGE analysis indicated that Hcp-1,
Hcp-2 actually contained three and four protein bands respectively. The molecular
weights of Hcp-1 were 6.7 kd, 10 kd, 15.4 kd; these of Hcp-2 were 4.4 kd, 6.7 kd,
9 kd, 15.4 kd. Our studies suggested that human cervical mucosa might secrete
some currently-unknown antibacterial polypeptides which play an important role in
the cervical defense against infection.
PMID- 10683975
TI - [Distribution of morphine in acute morphine-treated rats].
AB - The distribution of morphine in acute morphine-treated rats was studied by
immunohistochemistry (PAP). Samples were examined for morphine distribution and
localization in internal organs at 10-160 min after intraperitoneal injection of
morphine. The results showed that morphine was distributed in the heart,
hepatocytes, epithelial cells of the bile canalicular cells in liver, spleen,
kidney, adrenal glands, stomach parietal cells, small intestinal villus, pancreas
islet, sublingual glands and submandibular glands. Morphine was found in the
cardiac tissue, liver, spleen, pancreas islet, small intestinal villus at 10 min
after injection and in the cardiac tissue, stomach parietal cells at 160 min
after injection. The cause of the postmortem the distribution of morphine in
internal organs at different times after injection was discussed. The results of
this study may be used as a basis for the choice of samples for the forensic
toxicological analysis.
PMID- 10683976
TI - [The effect of removable partial denture on the composition of bacteria on the
apt-to-decay site of abutment teeth].
AB - This study was aimed at the composition of plaques which were on the base teeth's
carious sensitive sites, just after the insertion of the removable partial
denture (RPD). The results showed that the ratios of bacterial detection in
different teeth at the same period and those on the different sites of same teeth
at different periods were not significantly different. There was a tendency that
the detection ratio of the stomatococcus at the early period was higher than that
of other bacteria, but at the middle period the ratios declined, and at the late
period it was higher again. The detection ratio of the bacillus was on the
contrary in the study. At the same time, the composition of the plaques changed
significantly after the dentures had been used for 7, 14, and 21 days and 3
months. After 3 months, the ratios of the stomatococcus and the bacillas returned
to their normal levels. The 3 main cariogenic bacteria were all detected in this
study. The Streptococcus mutant was the dominant bacterium in the plaques and its
ratio went up with the time duration. The ratio for the lower second molar was
higher than that for the mandibular second premolar (P < 0.05). The detection
ratios of the Actinomyces viscosus and lactobacillus were lower. In conclusion,
after the insertion of RPD, the oral microbial ecosystem would be changed and the
cariogenic bacteria began to implant on the surface of the base teeth. So RPD is
a potential factor to cause the caries.
PMID- 10683977
TI - [Expression of CD44 molecule and its significance in uveal and conjunctival
melanomas].
AB - The aim of this study was to evaluate the role of over expression of CD44
molecule in the development and progression of uveal and conjunctival melanomas.
Flow cytometry (FCM) and immunofluorescence methods were used for detecting the
CD44V expression in uveal malignant melanomas (UMM), conjunctival nevi (CN) and
conjunctival malignant melanomas(CMM). The expression content of CD44 in 7 cases
of CMM was significantly higher than that in 5 cases of CN (P < 0.05); the CD44V
positive expression percentages in 7 cases of CMM and 40 cases of UMM were 71.43%
and 62.50% respectively; the expression content of CD44V in UMM was related to
scleral invasion (P = 0.0105); there was a negative correlation between the
expression content of CD44V and proliferative index (PI), S-phase fraction (SPF)
(P < 0.01; P < 0.05). The results suggested that the over expression of CD44V
might be involved in the development of CMM and UMM and related to local
infiltration ability of UMM and that the CD44V expression content detected by FCM
might be helpful in discriminating CN From CMM, but this waited for further
research confirmation.
PMID- 10683978
TI - [The LDL receptor activity of hepatocytes during cholesterol gallstone formation
in rabbits].
AB - In order to study the mechanism of cholesterol gallstone formation through rabbit
model which was induced by high cholesterol diet, we investigated the LDL
receptor activity of hepatocytes binding to 125I-LDL in different phases, namely
1, 2, 3 week group and 4 week, and in a control group besides. In this animal
experiment, cholesterol gallstones were induced at 2 week, 3 week and 4 week
groups in 4/10, 6/10, and 7/10 cases respectively. The Bmax values of LDL
receptor of hepatocytes binding to 125I-LDL decreased significantly in 3 week and
4 week groups (vs 1 week and control groups, P < 0.05). The kd values became
increased in 3 week and 4 week groups (vs 1 week and control group, P < 0.05),
which suggested that the activity of LDL receptor decreased gradually. In
conclusions owing to the intake of high cholesterol diet with the passage of
time, the decreased activity of LDL receptor of hepatocytes would reduce the
synthesis of bile acid.
PMID- 10683979
TI - [Changes of cerebral blood flow during hypoxicischemic encephalopathy in newborn
pigs].
AB - This study was designed to explore the change of cerebral blood flow during
hypoxic-ischemic encephalopathy (HIE). Sixteen newborn pigs were devided into
four groups: the normal control, 15 minutes after HIE, 30 minutes after HIE and
60 minutes after HIE. The shapes of the cerebral blood vessels were obsessed by
the prepared Chinese ink irrigation and the width and volume fraction of
capillary were tested and analyzed by stereographic method respectively. The
results showed the small blood vessels were interrupted with the passage of time.
At the time of 60 minutes after HIE, capilaries almost disappeared from view,
only a few ends of blood vessels in the sheap of a broken tree were seen. The
width of capillaries and small veins became more and more narrow as time went on.
The percentages of capillary volume fraction and small vein volume fraction
became smaller and smaller (P < 0.05). These demonstrate that the fall of
cerebral blood flow plays an important role in the development of HIE.
PMID- 10683980
TI - [Mechanism for the formation of F-V curve configuration analysed with tangent
time constant and wave-speed theory in normal adolescents].
AB - To understand the distribution of F-V curve configuration and the characteristics
of tangent time constant (tau t), and to explore the mechanical mechanism for the
formation of F-V curve configuration, we measured the tau t of high, mid, low
lung volumes (tau t75, tau t50, tau t25) from F-V curves in 728 normal
adolescents aged 8-19. The results showed that the distribution of the concave
type was the highest among 4 types of F-V curve configuration with a range of 40%
70%. Its tau t features were tau t75 > tau t50 > tau t25 and magnitude of tau t75
> 1s. Then the concave type and its tau t features were called "adolescent
fashion". Contrastedly, the distribution of the convex type was the lowest, only
4%-22%. The mechanical mechanism responsible for the formation of the concave
type was analysed with the wave-speed theory. During the growth of adolescents,
the lung elastic pressure and driving pressure increase with age. The diameters
of airways increase, especially those of the peripheral airways with profuse
branches. These changes lead to a decrease of resistance. Therefore, the critical
flow (Vc) or wave-speed flow (Vmax) of peripheral airways is raised, and the flow
there-in could hardly be limited. Thus the choke point (CP) will stay in trachea
for a longer period, leading to the elongation of the plateau towards the tail or
the concavity of the curve towards the volume axis and hence the formation of the
concave type.
PMID- 10683981
TI - [A study of the adenosine deaminase polymorphism in a Chinese Han population by
the PCR method].
AB - The study of genetic polymorphism of adenosine deaminase (ADA) has not been
reported in China and abroad. The target DNA was amplified by PCR. The amplified
product was then digested with Pst I, and run on a 9% polyacrylamide gel
electrophoresis and followed by AgNO3 staining. ADA polymorphism, was determined
in 80 unrelated individuals Chinese Han polulation. Five alleles and 14 genotypes
were detected. The gene frequencies were ADA * 10 = 0.15625, ADA * 11 = 0.31875,
ADA * 12 = 0.23750, ADA * 13 = 0.23125 and ADA * 14 = 0.05625 respectively. The
heterozygosity was 0.8 and the discrimination power (DP) was 0.89. The
distribution of observed genotypes frequencies was in good agreement with the
Hardy-Weinberg law. The study of three families demonstrated that this locus was
inherited according to Mendelian law. The technique is quite simple, fast,
extremely sensitive, and it does not require the use of radioisotopes. This new
method may be used for the forensic identification and paternity testing.
PMID- 10683982
TI - [Determination of copper, iron and zinc in hair of mentally retarded children by
oscillopolarography].
AB - The oscillopolarographic method (proposed by Ding Jianwen)for the simulltaneous
determination of copper, iron and zinc in hair was further studied and applied to
the investigation of copper, iron, zinc content in hair samples from 46 mentally
retarded children and 49 healthy children. For copper, iron, zinc, the detection
limits were 0.03, 0.03, 0.01 microgram/ml, dynamic range 0.05-15, 0.05-2.5, 0.2
10 micrograms/ml, the RSD of sample analysis 3.2%, 3.3%, 2.4%, the recoveries 96:
0%-105.2%, 2%, 97.3%-109.0%, 94.7%-107.7%, respectively. The difference between
the results for the same sample by this method and the atomic absorption
spectroscopic method was no statistical significance. The results showed that the
copper content and iron content of hair samples from mentally retarded children
were significantly lower than those of healthy children.
PMID- 10683983
TI - [The risk of lung cancer and mesothelioma in farmers exposed to crocidolite in
environment].
AB - To assess the risk of lung cancer and mesothelioma after environmental exposure
to crocidolite for 20-30 years, a retrospective cohort study was carried out in
farmers who had been exposed to crocidolite in environment. 1610 subjects were
followed up for 9 years (Jan. 1, 1987 Dec. 31, 1995). The control group consisted
of 7646 farmers who resided in the noncrocidolite pollution rural area in the
same province. The results showed that the annual mortality rate was 43.75 per
100,000 population for lung cancer, and 36.46 per 100,000 for mesothelioma.
Significantly high risks of lung cancer (RR 5.67) and mesothelioma (RR 182.3)
were noted. These results demonstrate a strong causal association between lung
cancer, mesothelioma and exposure to crocidolite.
PMID- 10683984
TI - [Study on the power of O/E method].
AB - This paper addresses the methodology of calculating the power of O/E method and
introduces the relevant algorithm for estimating the sample size. Based on the
principles of hyporthesis testing and Poisson distribution, the power can be
worked out for given sample size, baseline rate(pi 0) and the factor of
increasing (gamma). The power increases with the increase in sample size, pi 0
and gamma. In shape the power is not a continuous smooth line but a zigzag line.
The method illustrated in this paper can be also used for estimaging the sample
size of studies on the intervention of diseases.
PMID- 10683985
TI - [Pathologic grading and differential diagnosis on oligodendroglioma].
AB - To investigate the histological characteristics of oligodendroglioma (ODG), 65
cases of ODG were observed with light microscopy and partially with
immunohistochemistry. According to WHO classification of tumors, 65 cases of ODG
were graded in degree of differentiation of tumor cells. Of these, 19 cases
belonged to grade I, 32 grade II, and 14 grade III. CONCLUSION: Except the degree
of differentiation, some other criterlons as cellular density, mitotic
activities, and the presence of focally concentrated apoptotic cells are closely
related to grading of ODG.
PMID- 10683986
TI - [Cytokines release related to cardiopulmonary bypass in patients with prosthetic
valve replacement].
AB - To examine cytokines release related to cardiopulmonary bypass(CPB), the anthers
investigated the possible differences in cytokines responses between patients
undergoing prosthetic valve replacement (study group, n = 10) and those receiving
closure of patent ductus arteriosus or pericardiectomy(control group, n = 9).
Venous levels of interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R),
interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-10
(IL-10) were measured at multiple time points before, during and after operation.
As compared with pre-operative values, IL-2 levels in both groups decreased
significantly (P < 0.05), and the levels of sIL-2R, IL-6, TNF-alpha, and IL-10 in
both groups increased significantly at multiple time points post-operative (P <
0.01). All the values of cytokines returned to pre-operative levels at 7th post
operative day. Although there were no pre-operative differences in these
cytokines between the two groups (P > 0.05), the post-operative changes of
cytokines in study group was more obvious than that in control group (P < 0.01).
In study group IL-10 rose to a peak value of around 620 pg/ml at the end of CPB
while IL-6 and TNF-alpha levels reached their peak values of around 88 pg/ml and
52 pg/ml respectively at 1st post-operative day. IL-10 has been reported as an
antiinflammatory cytokine. The preceding IL-10 peak value, as compared with the
peak values of IL-6 and TNF-alpha, could be associated with the interplay and
regulation of cytokine network. On the other hand, in control group the levels of
IL-6, TNF-alpha, and IL-10 reached their peak values at 1st post-operative day
simultaneously. The values were 34 pg/ml, 36 pg/ml, and 162 pg/ml respectively.
This result suggests that besides surgical stress mediated cytokines production
or suppression, CPB itself also results in obvious changes of cytokine
metabolism. However further studies are needed to elucidate the underlying
mechanisms and clinical value of post-operative cytokines production or
suppression related to CPB in patients with prosthetic valve replacement.
PMID- 10683987
TI - [Cromakalim inhibits endothelin-1 induced pulmonary hypertension in rats].
AB - There is evidence that endothelin-1 (ET-1) and potassium channel may play an
important role in the development of pulmonary hypertension. To evaluate the
effect of ATP-sensitive K+ channel opener on pulmonary hypertension induced by ET
1, catheter was inserted into the pulmonary artery in ten male Wistar rats which
had had pulmonary hypertension established by infusion of ET-1 (1.5
micrograms/kg), and then cromakalim were injected with a dose of 150
micrograms/kg. The mean pulmonary arterial pressure (mPAP), cardiac output (CO)
monitored before and after infusion of ET-1, and 1 min, 5 min, 10 min after
cromakalim injection, and pulmonary vascular resistance (PVR) were calculated. It
was found that the mPAP was significantly increased, from 2.36 +/- 0.24 kPa to
3.32 +/- 0.49 kPa(P < 0.01), and PVR also increased, by infusion of ET-1. After
cromakalim injection, mPAP were decreased to 2.50 +/- 0.62 kPa in 1 min, 1.14 +/-
0.18 kPa in 5 min and 2.33 +/- 0.52 kPa in 10 min, PVR decreased significantly.
It is suggested that there is interaction between ET-1 and potassium Channel, and
Cromakalim decreases mPAP in part by inhibiting the response of pulmonary artery
to ET-1.
PMID- 10683988
TI - [Semiquantitative measurement of progesterone receptors in luteal-phase-defect
endometrial cells during secretory phase].
AB - To investigate the changes of endometrial progesterone receptor (PR) of luteal
phase-defect (LPD) patients during the secretory phase, thirteen patients with
complaints of infertility or habitual abortion were studied. During the early-mid
secretory phase, endometrial tissue was obtained by dilatation and curettage (D &
C) for histological and receptor study: meanwhile serum E2, P, FSH, LH and PRL
were measured. Based on histologic diagnosis, the patients were divided into two
groups: the LPD group (n = 7) and the normal control group(n = 6). PR content was
determined by immunohisto-chemical (IHC) assay. The results showed that during
the early-mid luteal phase a significantly low PR content on endometrial
glandular nucleus was observed in LPD group, compared with normal control(6.75 +/
2.57 vs 9.50 +/- 1.64 P < 0.05), but no difference in serum progesterone was
noted between the two groups. These findings suggest that during early-mid
secretory phase, PR content on endometrial glandular nucleus decreases in LPD
cases, which results in deficient response of endometrium to proper stimulus of
progesterone. This change may cause endometrial secretory deficiency and blockade
of embreyo implantation. That is why infertility or habitual abortion happened.
PMID- 10683989
TI - [Comparison of the effects of inhaled nitric oxide and intravasculare regitine on
pulmonary gas exchange in young dogs with oleic-acid acute lung injury].
AB - In order to find an agent which truly improves hypoxemia of some serious
pediatric lung diseases, the authors examined the independent effects of nitric
oxide inhalation and regitine infusion on blood gases, intrapulmonary shunt and
hemodynamics in young dogs with oleic-acid acute lung injury. After nitric oxide
inhalation, the results showed moderate increases in PaO2 and SaO2 (P > 0.05) and
a significant decrease in Qs/Q tau ratio (P < 0.01). There was a significant
decrease of PAP(P < 0.05), while SAP remained unchanged. After regitine infusion,
however, there were marked decreases in PaO2 and SaO2 (P < 0.01); meanwhile, Qs/Q
tau rose (P < 0.05). These suggest that with the presence of pulmonary pathology
nitric oxide inhalation may alleviate the elevated pulmonary pressure without
alteration in systemic artery pressure; so it can improve pulmonary ventilation
perfusion distribution and cause favorable changes in blood gases. On the other
hand, regitine, as a non-selective vasodilator, reduces pulmonary artery pressure
at the cost of significant worsening of blood oxygenation and systemic
hypotension; so its routine use in childhood pulmonary diseases should be
cautiously considered.
PMID- 10683990
TI - [The relation between nutrition and pulmonary ventilation in patients with
chronic obstructive pulmonary disease during the relieved period].
AB - To observe the effect of nutrition on pulmonary ventilation in aged patients with
chronic obstructive pulmonary diseace (COPD) during the relieved period, the
pulmonary function (MVV, PVC, FEV1, MMEF) of 261 aged patients with COPD was
tested during the relieved period. The results showed that the MVV (48.75% +/-
19.9%) tested in the patients with malnutrition was significantly lower than that
tested in the patients with normal nutrition (59.1% +/- 22.6%) (P < 0.01) while
there was no marked difference in the ventilation in their large and small
airway. It is conluded that malnutrition of the patients with COPD affects the
constrictive function of respiratory muscle and thus results in a decrease in
MVV.
PMID- 10683991
TI - [Esophageal reconstruction using ilecolon in children--a report of ten cases].
AB - The use of the ileocolon as a substitute for esophagus in children has been a
well-established surgical procedure. Between 1992 and 1995, ten retrosternal
esophageal substitutions using an ileocolic interposition were performed. The
ages of the children ranged from 2 to 8 years. The esophageal strictures were
secondary to ingestion of caustic liquid. No death occurred in the intra- and
post-operation period. Cervical ileoesophageal anastomotic leaks took place in 2
cases as the early major postoperative complications, which healed spontaneously.
Three cases of ileoesophageal anastomotic strictures were noted in the follow-up
period. The surgical indications, the treatments of anastomotic leaks and
strictures, and the importance of long-term follow-up were discussed.
PMID- 10683992
TI - [Free jejunal grafts for reconstruction of pharynx and cervical esophasgus].
AB - Eleven patients with hypopharyngeal carcinoma were treated surgically and the
pharynx and cervical esophagus were reconstructed with free jejunal grafts
through the technique of microvascular anastomosis. The microvascular anastomosis
were all successful and the patients all survived the operations. The operations
were performed at one time with only a few complications. There were 2 cases of
pharyngeal fistula and 1 case of bleeding from the anastomotic site. The patients
could eat by their mouths and swallow very well just 15 days after the operation.
The 3-year suvival rate was 36%. The main causes of death were the recurrence and
the metastasis to the cervical lymph nodes. We came to the conclusion that the
operation is safe with high success rate and no mortality during operation, and
it is less injurious than the gastropharyngeal anastomosis. The key point of the
operation is the surgeon's mastery of the microvascular anastomosis technique.
PMID- 10683993
TI - [A retrospective study of neurogenic pulmonary edema following intracranial
injury without open wound].
AB - To find factors that relate to the occurrence of neurogenic pulmonary edema(NPE)
following intracranial injury without open wound, thirty-founr autopsies on such
cases were studied retrospectively. The rate of NPE in the 34 cases was 41.18%,
and it was 44.44% in those aged 10 to 49. The rate of NPE in the persons who died
immediately or 0-6 hours after injury was 41.18%, and in those who died 7-48
hours after injury, 41.18% too. The rate of NPE was 69.23% for the cases with
only one site of bleeding and 23.81% for ones with multiple sites of bleeding.
These findings suggest that the occurrence of NPE is not related with the
duration of time after head injury or the location of brain injury, but it is
related with the severity of brain injury.
PMID- 10683994
TI - [Isoelectric focusing and immunoblotting identification of human ApoE phenotype].
AB - A simple, rapid and accurate method for phenotyping sera apoE has been developed.
In this method 10 microliters serum or plasma are incubated with Dithiothreitol
and Tween-20 for 15 min and then applied to 5% polyacrylamid gel containing pH 4
8 ampholyte and 3 mol/L urea. After 2 h focusing, the apoE bands are transferred
to Nitrocellulose membrane. apoE bands are made visible by immunoblotting and TMB
is used as the substrate. Identification phenotype is easily accomplished by
noting the location and number of protein bands. 56 samples shows apoE 3/3 in 47
cases, apoE 2/3 in 2 cases, and apoE 3/4 in 7 cases. This method is well suited
for large-scale population studies and clinical labs.
PMID- 10683995
TI - [Extraction and purification of mouse H-2 antigen].
AB - This study was designed to purify the mouse major histocompatibility complex
antigen (H-2Ag). The detergent was used to extract the crude H-2Ag, and
monoclonal antibodies affinity chromatography was applied to purify H-2 antigen.
A 45 kd heavy chain and a 12 kd light chain from the purified proteins were shown
by electrophoresis. Besides, the pure H-2 antigen was found to have immunological
and biological activity. This method should be useful in purifying large
quantities of H-2Ag for the researches in transplantation and functional analysis
of H-2 antigen.
PMID- 10683996
TI - [The effect of a vaccine made from 39kd hydrophobic outer membrane protein of
Leptospira interrogans on neurohumoral and red cell immunity function of the
guinea pigs].
AB - A randomized control trial was conducted to determine the immunoprotective
efficacy of OmpL39. 36 guinea pigs were divided into OmpL39 group, whole
leptospiral cell vaccine (WLCV) group, other proteins of Leptospira group, and
negative control group (normal saline, NS). The results showed that all the
guinea pigs of infected OmpL39 and WLCV still survived, but all the control
guinea pigs died. Immunoprotective efficacy was 100% for OmpL39 and WLCV. OmpL39
levels were similar to WLCV levels and higher than controls (P < 0.05). These
suggested that OmpL39 could be used as important immunoprotective antigen to
develop the genetic vaccine of the targeting delivery system. Also it was
observed that OmpL39 could produce 100% immunoprotective efficacy, have higher
MAT level (> 1:3200) and regulate 5-HT, 5-HIAA, DA, NE. The 5-HT, DA, NE
concentration was lower and 5-HIAA was higher than that of controls after
stimulating the guinea pigs with OmpL39 (P < 0.05). The results suggested that
OmpL39 genetic vaccine could produce immunity function and have an active effect
on absorbing inflammation and protecting organs and tissues. Besides, the red
cell immunity efficacy of the guinea pigs was changed during immunity response
and the RBC-C3b RR and the RBC-ICR were increased. The RFER was increased; the
RFIR was decreased. RFER/RFIR was remarkably higher than that of control (P <
0.05). These suggested that OmpL39 could increase red cell immunity function.
PMID- 10683997
TI - [Partially purified antibacterial polypeptides from granules of human large
granular lymphocytes].
AB - This was a study on the antibacterial activity of human large granular
lymphocytes (LGL). In our previous work, three antibacterial fractions named HLP
1, HLP-2 and HLP-3 had been identified from the acid-soluble extracts of the
granules of LGL by using the gel overlay technique. The present study
demonstrated that HLP-1, HLP-2 and HLP-3 separated by preparative acid-urea
polyacrylamide gel electrophoresis were potently bactericidal against E. coli MI
35P, S. aureus ATCC 25923, P. aeruginosa ATCC 27853 when tested for their
antibacteiral activities by using both agarose radial diffusion assay and gel
overlay technique. SDS-PAGE analysis showed that the HLP-3 was almost purified
with the molecular weight of 7 kd. The HLP-1 and HLP-2 were more complex, and the
ranges of molecular weight were 5.6-13 kd and 5.6-8.8 kd respectively. Our study
suggests that the granules of human LGL might contain some low molecular weight
antibiotic peptides which play an important role in human innate immunity.
PMID- 10683998
TI - [Cloning and orientation of cefoperazone resistance gene on plasmid pFC in E.
coli HX88108].
AB - Cefoperazone resistance gene (CPZr) has been cloned from plasmid pFC of E. coli
HX88108 using the vector pMB9 (TCr, 5.3 kb). The plasmid pFC DNA was partially
digested with Sau3A I, and its 1-2 kb fragments were ligated into BamH I site of
vector plasmid pMB9. The recombinant DNA was then transformed into E. coli DH5
prepared using calcium chloride. CPZ resistant bacterial colonies were selected
on the agar SOB plates containing CPZ (40 micrograms/ml). The resistance to CPZ
could be stably reserved in generation after generation. The recombinant plasmids
which encoded CPZ resistance were designated pFL11, pFL25, pFL33, pFL82, pFL86
and pFL102. Rapid small-scale preparation of plasmid and DNA restrication enzyme
analysis were used for identification of bacterial colonies. Five plasmids DNA
physical maps have been established. Comparison of recombinant plasmids maps with
pFC map confirmed that the CPZr gene was oriented between nucleotide no. 3200 bp
and no. 4800 + 40 bp of plasmid pFC total sequence. Its molecular weight was
about 1.6 kb. There were EcoR I, Sma I and Pvu II sites within CPZr gene.
PMID- 10683999
TI - [Study of macroencapsulated islet xenografts for treatment of diabetes in mice].
AB - The aim of this study was to prevent rejection after islet xenotransplantation.
Islet obtained from Wistar Furth rats were macroencapsulated with agarose and
collagen before transplanted into diabetic C57BL/6, B6AF1, and BALB/c mice. The
results showed that the diabetic condition was reversed in 92.3% of recipients
transplanted with macroencapsulated islets. The normoglycemic state of recipients
was maintained 125.8 +/- 57.9 days without immunosuppression. The glucose
tolerance curves in these mice were similar to those of normal mice. The
macroencapsulated islets retrieved 103 days after transplantation showed no
evidence of tissue reaction or fibrosis. These indicated that the
macroencapsulated islets serve both to achieve and maintain normoglycemia of
recipients, as well as to protect islet xenografts from rejection.
PMID- 10684000
TI - [Study of flow field uniformity downstream of mitral stenosis using Doppler
echocardiography].
AB - To research into the relationship between mitral lesion, stenosed degree and flow
field uniformity downstream of mitral valve, we adopted the advanced color
Doppler echocardiographic technique to conduct a quantitative study of flow field
uniformity downstream of mitral valve in sixty patients with varying-degree of
mitral stenosis in vivo. Twenty normal persons acted for comparison. The results
showed that there was a linear correlation between the extent of valvular lesion,
the stenosed degree and flow field uniformity downstream of mitral valve. We
conclude that the more severe the mitral lesion is, the more grave the stenosis
is and the worse the flow field uniformity is. This suggests that there might be
a reciprocity between valvular lesion and flow field uniformity as well as
turbulent shear stress, which should be further studied.
PMID- 10684001
TI - [A pharmacokinetic study of 125I-VIP in rat].
AB - To investigate the pharmacokinetics of 125I-VIP in normal rats, a single dose of
125I-VIP was given intravenoualy to rats and from 0.5 to 240 min after the
administration, serial blood samples were taken and measuredp by gamma
scintillation counter and finally expressed as mu Ci/ml blood. The data were
analyzed by computer for the estimation of pharmacokinetic parameters and the
judgment of compartment model with a program of 3P87. The results demonstrated
that the pharmacokinetics of 125I-VIP in rat fitted with the three-compartment
model(Wi = 1) based on either the comparison of the calculated theoretic value
with measured concentration, the values of AIC and r2 or F test for the model
judgment, and that the average distributive half-life of 125I-VIPk in blood was
1.36 min, the elimination half-life(T1/2 beta was 67.3 min, the K12(3.589 min-1)
was markedly higher than that of K12(0.045 min-1), and the K21:K12(0.0127) was
obviously lower than that of K31:K13(0.215). The present study indicates that
125I-VIP has a rapid uptake and slow elimination in the tissues with high density
and affinity VIP receptors (the second compartment).
PMID- 10684002
TI - [Study of a new type of material substituted for human hard tissues-hydroxyl poly
calcium sodium phosphate: histologic report implants in mandible of animals].
AB - This study was aimed to evaluate the histocompatibility of hydroxyl poly calcium
sodium phosphate (HPPA) preliminarily. HPPA and hydroxylapatite were implanted in
the mandibular defect in dogs. The implant-bone interface was observed by using
stereomicroscope and decalcified histologic sections. The result demonstrates
that HPPA has well-osseous integrated property after being implanted into bone
tissues. This suggests that HPPA might be a new material of future excellence in
substitution for human hard tissues.
PMID- 10684003
TI - [Effects of surface roughness of two restorative materials on early Streptococcus
sanguis adhesion in vitro].
AB - This was an in vitro study aimed at the surface roughness of two kinds of
commonly used restorative materials resin and alloy necessary to affect the
adhesive behavior of Streptococcus sanguis(S. s) on them after 24 h. The surface
roughness(SR) of each tested sample was evaluated with a profilometer
quantitatively and observed with scanning electron microscope (SEM)
morphologically. Then the adhesive microbial amount was determined by the clone
forming unit counting method, and adhesion morphology was analyzed with SEM. The
result showed a positive linear relation between the adhesion amount of S. s and
the SR. The relative coefficients were rresin = 0.46(P < 0.01) and ralloy =
0.25(P < 0.01) respectively. These suggest the SR of the restorative material is
important for the early adhesion of oral microbes in vitro. Therefore, before the
prothesis is inserted in the patient's oral cavity, its surface should be
polished as smoothly as possible so that the bacterial adhesive amount on its
surface can be decreased, and hence the patient may keep in good oral health and
have a prolonged use of the prothesis.
PMID- 10684004
TI - [HA-coated titanium implants used as orthodontic anchorage. An experimental
investigation of implant stability and peri-implant neck tissue in dogs].
AB - This study was aimed at the feasibility of using HA-coated titanium endosseous
implants as orthodontic anchorage. These implants installed in dog's mandibles
were loaded with the orthodontic force of 150 g for 3 months. The stability of
the implant and the peri-implant neck tissue were investigated with radiograph
and index evaluation. The findings demonstrated that no implant was mobile or
loose or dislocated. The soft tissue around the cervical part of the implants had
a slight inflammation because of bad oral hygiene and the stimulation of residual
food attached to the stainless string. However, no resorption of marginal
alveolor bone was found under sustained orthodontic force. The above results
suggest that the HA-coated titianium implant can be used as anchorage for short
term orthodontic treatment.
PMID- 10684005
TI - [Protective effects of flunarizine and vitamin C on isolated rat heart subjected
to ischemia-reperfusion injury].
AB - Isolated rat heart was subjected to Langendorff perfusion for 10 minutes of total
global ischemia, and reperfusion for 15 minutes. The content of myocardial
intracellular calcium, content of oxygen free radical induced lipid peroxide
mitabolite-malondialdehyde (MDA), content of Lactic dehydrogenase (LDH) in
coronary effluent, and the change of myocardial morphology were studied. The
effects of flunarizine(FNZ) and/or vitamin C(Vit C) on the above parameters were
observed. The results showed that, at 15 minutes of reperfusion, the contents of
myocardial intracellular calcium, of MDA in myocaredium and of LDH in coronary
effluent in the FNZ + Vit C group, Vit C group and FNZ group were all lower than
those in the control group, and the change of morphology in the three groups was
also slighter than that in the control group. When FNZ and Vit C were
administered together, the effect was more marked and equivalent to the sum total
of the effects of the two drugs. These suggest that both FNZ and Vit C reduce
reperfusion injury through suppression of myocardium calcium overload and oxygen
free radical damage.
PMID- 10684006
TI - [Relationship between nitric oxide synthase, endothelin and the initiation of
hypertension and atherosclerosis].
AB - To investigate the relationship between nitric oxide synthase (NOS), endothelin
(ET) and the initiation of hypertension and atherosclerosis, 5 hypertensive rats
(systemic pressure 22.7-24 kPa), 5 atherosclerotic rats (by cholesterol-rich
diet, 3 months), and 5 normal Wistar rats were used for determination of the
distribution of NOS and ET of aorta by histochemical methods. The levels
determined in the three groups were quantitated and compared by computer-imaging
analysis. The results showed that in early stage of atherosclerotic process, the
NOS decreased while the ET increased in aorta. In early stage of essential
hypertension, however, both NOS and ET levels increased. These results suggest
that the increased ET and the change of NOS may play a role in the pathogenesis
of hypertension and atherosclerosis.
PMID- 10684007
TI - [A comparison of chromosome fragile sites in elderly and young people].
AB - In this comparative study, the authors investigated the chromosome aberrations
and expression of fragile sites in the lymphocytes which were collected from 45
elderly people and 29 young people and were cultured with FUDR for 24 hours. The
results showed that the aberration rate was 24.75% for elderly people, but 4.22%
for young people (P < 0.01): that the expression of fragile sites was 45.94% for
elderly peoples, but 23.02% for young people (P < 0.01): and that the relation of
aberrations with fragile sites was 79.98% for elderly people, and 92% for young
people. These findings suggest that chromosome aberration is in close association
with fragile site.
PMID- 10684008
TI - [Study on the relationship between occupational factors and work ability of
middle aged workers].
AB - Based on the assessment of work ability index (WAI) of middle aged workers,
associations between occupational factors and work ability decline of middle aged
workers were examined in a case-control study. 1037 workers (age ranged from 40
to 60) were included in the study. The study group comprised 180 workers of mean
age 47.71 years representing those who's work ability decreased. The control
group comprised 857 workers of mean age 47.22 years representing those who's work
ability was on a normal level. Results showed that some common occupation hazards
such as dusts, noise, vibration, humidity, and high temperature were more
frequently occurred in work environment of the study group than that of the
control group. High risks were found in workers with these hazards. Another
significant risk factor of work ability decline was heavy physical load.
Significantly elevated risks were observed for physical load perception(OR =
2.52), repetitive work (OR = 1.36), poor work postures(OR = 1.48), and carrying
heavy loads(OR = 1.59). As compared to physical loads, mental loads were not in
relation to work ability decline. The information about occupational factors
affecting work ability will be helpful for redesiging the work for the middle
aged workers.
PMID- 10684009
TI - [Characteristics of F-V curve configuration and its tangent time constants and
its wave-speed mechanism in normal humans above 50 years old].
AB - To understand the characteristics of F-V curve configuration and its tangent time
constant (tau 1) in normal humans above 50 years old, the tau 1 at high, mid, low
lung volumes (tau 175, tau 150, tau 125) were measured from F-V curves for 135
normal humans aged 50-84. The results showed that the convex type was the most
frequent one (40%-75%) among the 4 types of F-V curve and its tau 1
characteristics were tau 175 > tau 150 < tau 125 and magnitude of tau 175 < 1s;
on the other hand, the concave type was the least frequent one (0.18%). These
suggested that the convex type and its tau 1 characteristics might be the changes
in senility. Further, the mechanical mechanism for the convex type of F-V curve
configuration was explored.
PMID- 10684010
TI - [Relationship between tumor cell proliferating activity and biological behavior,
prognosis in laryngeal carcinoma].
AB - Using PC 10, an antibody to proliferating cell nuclear antigen (PCNA) and a
standard immunohistochemical staining the authors examined 11 cases of simple
hyperplasia of epithelium (SHE), 32 cases of atypical hyperplasia of epithelium
(AHE) and 42 cases of laryngeal squamous cell carcinoma (LSCC) for expression of
PCNA, a protein associated with DNA polymerase dalta and DNA replication, a
marker for tumor cell proliferation. The results revealed that PCNA indices in
SHE, AHE and LSCC were 9.5%, 27.33% and 68.05%, respectively. The PCNA indices
were 63.68%, 69.57%, 71.18% in the well, moderately and poorly differentiated
LSCC, respectively, there were significant differences. The PCNA indices were
63.88%, 70.82%, 66.20% and 69.04%, respectively in stages I, II, III, and IV of
LSCC; no significance was found. There was a strong negative correlation betwee
survival time and the tumor cell proliferative activity (r = 0.6243). PCNA might
provide a useful tool for studying cell proliferation in situ under normal and
pathological condition.
PMID- 10684011
TI - [Prognostic significance of P53 protein expression in patients with colorectal
adenocarcinoma].
AB - In order to investigate the prognostic significance of P53 protein expression in
the patients with colorectal adenocarcinoma, we used the P53 monoclonal antibody
and ABC immunohistochemical method combined with the repairing method for antigen
by microwave oven to study the relationship between the overexpression of P53
protein and the prognosis in 40 cases of colorectal adenocarcinoma. The results
showed that 65% (26/40) cases of colorectal adenocarcinoma were positive for
overexpression of P53 protein. The 5-year survival rate for positive cases was
50%, but 87.5% for negative cases. These findings suggest that the overexpression
of P53 protein closely associates with the prognosis in colorectal adenocarcinoma
(P < 0.05), thus it might become a new prognostic indicator. The prognosis in
colorectal adenocarcinoma could be predicted thoroughly by considering the
expression of P53 protein in combination with the traditional prognostic factors.
PMID- 10684012
TI - [The role of lens epithelium in cataract formation in diabetic rats].
AB - This study was designed to evaluate the changes and the role of lens epithelium
in sugar cataract formation, in regard to the fact that the highest level of
aldose reductase is found in this layer of lens. By light and electron
microscopy, we examined the histological changes of central epithelium in lens of
rats made diabetic with streptozotocin (STZ) with or without AL1576, an aldose
reductase inhibitor, at varying periods of time ranging from 5 to 40 days after
intraperitoneal injection of STZ. Also, we examined Na-K-ATPase activity in lens
epithelium of rats with diabetes, diabetes plus AL1576 and normal controls at the
time of 30 days. The results showed that the first detectable abnormalities
occurred after 15 days of STZ injection and were limited to the lens epithelium;
cell edema, intracellular vacuoles and extention of rough endoplasmic reticulum
pool were remarkable; that AL1576 could prevent almost all of the lesion
mentioned above; and that Na-K-ATPase activity in lens epithelium of rats with
diabetes increased at the time of 30 days. The findings suggest that lens
epithelium may play an important role in sugar cataractogenesis.
PMID- 10684013
TI - [Quantitive analysis of 5-hydroxytryptamine levels on edges of incised skin of
rats].
AB - To find index for early diagnosis of antemortem wound, the authors used the ICS
analysis in a quantitive study of 5-hydroxytryptamine(5-HT) levels on rat's
incised-skin antemortem wound in comparison with the postmortem wound inficted at
various intervals. The results showed that the 5-HT increased significantly at 5
min, reached a peak at 15 min and decreased at 60 min on antemortem wounds. The 5
HT levels of antemortem groups were prominently high (more than 40%, P < 0.05) as
compared with those of postmortem group and the levels of 5-HT on the wounds of
postmortem groups were higher (35.77%, P < 0.05) than those of controls as well.
The authors suggest that in the cases where the levels of 5-HT are as high as 40%
on the edges of the injured skin, the injury should be considered an antemortem
wound.
PMID- 10684014
TI - [Morphologic changes of red blood cells in various conditions under scanning
electron microscope].
AB - To study the changes of RBC in various conditions, blood clots elapsed 6 days in
water and air and bloodstains stored in variant time were observed under Scanning
Electron Microscope (SEM). The results showed that the morphology of RBC elapsed
6 days in water and air seemed to retain their integrity. They were measured 5,
48-5, 88 microns in diameter, whereas the RBC in the bloodstains stored 14 years
were obviously disfigured and some appeared membrane cracking. However, the
structure of RBC membrane was well recognized under the SEM. The morphological
changes under the SEM and the forensic significance of the RBC were discussed.
PMID- 10684015
TI - [Applied anatomy of the vascularity in the ileocolic region and its clinical
significance].
AB - To understand the characteristics of the patterns of arteries and veins
distributed over the ileocolic segment, 50 cadavers were studied by gross
anatomy. The arteries, veins and their paracolic anastomoses distributed over
ileocecal region, ascending colon and transverse colon were observed. The results
showed that the distribution pattern of venous vessel was far more constant than
that of artery, that the arrangements of artery in the ileocolic segment were
classified into 7 types, and there were no interruption of paracolic anastomoses
between arteries. But in 3 specimens the paracolic anastemoses between the right
colic vein and the middle colic vein were completely interrupted. These findings
may be useful in guiding clinical practice and preventing postoperative
complications in ileocolic replacement of esophagus.
PMID- 10684016
TI - [The effect of partial hepatectomy and portal vein occlusion on aminopyrine
metabolism capacity of the liver in rats].
AB - To observe the variation of metabolic function and anatomical weight of the liver
after partial hepatectomy and occlusion of portal branches feeding the same
magnitude of the liver lobes, hepatic 14C-aminopyrine demethylation capacity
determined by aminopyrine breath test and liver weight in rats were examined and
compared in series in this study. The results showed that 14CO2 expiratory
clearance rate was reduced by 50% at 2 hours and by 70% at 24 hours after 70%
hepatectomy. Then it increased gradually and was similar to the preoperative
level in 2 weeks. The remnant liver weight was lowest at 2 hours and increased to
80% of the control in 7 days after 70% hepatectomy. It recovered to normal in 2
weeks. In 90% hepatectomy group, 14CO2 expiratory clearance rate decreased by 90%
at 2 hours after operation. Thereafter, all rats died very soon. In the 2 portal
vein occlusion groups, 14CO2 expiratory clearance rate had little change at 2
hours and it declined by about 40% at 24 hours after ligation of portal branches
feeding 70% or 90% liver mass. It recovered gradually and returned to the
preoperative level in 2 weeks. The total liver weight in 2 portal occlusion
groups was not significantly different from that in the control except that it
was slightly lower than the control at 24 hours after operation. This
experimental study suggests that comparing deprivation of portal blood feeding
partial liver mass with corresponding partial hepatectomy, the former can not
only keep the anatomical liver weight relatively stable but also produce a lesser
damage to hepatic metabolic function.
PMID- 10684017
TI - [Respiratory muscle function and serum enzymology in hyperthyroidism before and
after treatment].
AB - To investigate the effect of hyperthyroidism on respiratory muscle function and
its possible mechanism, the thyroid function, serum enzymology, serum potassium,
pulmonary function and respiratory muscle function were examined in 60 patients
with Grave's disease before treatment and 26 patients among them after treatment,
and 20 normal subjects as control. T3, T4, and FT4 increased while FVC and PImax,
which reflect the respiratory muscle strength, and Pi/PImax, which reflects the
reserve capacity of inspiratory muscle, decreased significantly in the 60
patients with Grave's disease, compared with the ones of normal subjects. The
comparison of above measurements in the 26 patients between before- and after
treatment showed that respiratory muscle strength increased obviously along with
the improvement of throid function. The serum enzymology, potassium and TSH,
however, were not abnormal and not changed after treatment. The thyroid functions
in 10 patients with hyperthyroid heart disease were not different, compared with
the ones of other 50 patients without hyperthyroid heart disease, but their
respiratory muscle strength was significantly lower than the ones of latter. The
above results suggested that hyperthyroidism could lead to significant decrease
of respiratory muscle strength and its reserve capacity, whereas treatment for
hyperthyroidism would improve respiratory muscle function, so the measurement of
respiratory muscle function in hyperthyroidism cases might be useful in
prediction of hyperthyroid heart disease.
PMID- 10684018
TI - [Effects of fat emulsion on serum lipid, apo A I, apo B100, LCAT, KBR of
postoperative patients with liver disorder].
AB - Twenty post-operative patients with liver disorder were divided randomly into two
groups. Ten of them received mean 0.82 g.kg-1.d-1 fat emulsion(42% of the total
calorie), and the other ten received mean 1.72 g.kg-1.d-1 fat emulsion (52% of
the total calorie) via vein during 5 post-operative days. Their serum lipid, apoA
I, apoB100, ketone body ratio (KBR), fat clearance, LCAT and so on were
investigted. The results suggest that it is safe for liver-disordered patients
with slight or even moderate abnormality of liver function to receive mean 0.82
g.kg-1.d-1 and 1.72 g.kg-1.d-1 fat emulsion after operation and the use of mean
1.72 g.kg-1.d-1 fat emulsion will do no harm but good to liver function.
PMID- 10684019
TI - [A survey of prostate symptoms in old male population].
AB - To know well the prostate symptoms in old men, the prostate symptom scores of 412
male residents over 60 years of age in Chengdu area (116 in city and 296 in
countryside) were investigated by using I-PSS. The results showed that there was
a significant difference between the city and countryside in terms of symptoms
score(P < 0.05) and quality of life scores (P < 0.05). No significant difference
was noted among the three age groups (P > 0.05). However, the mean score and the
percentage of high score section in the elder group were higher than those in the
younger group. The prevalence of benign prostate hypertrophy (BPH) and the
demands on quality of life in city were different from those in countryside, and
the prevalence rate of BPH increased with age.
PMID- 10684020
TI - [Effects of mifepristone on ICE expression and Fas expression in early pregnant
chorionic villi].
AB - This study addressed the question whether mifepristone has any effect on
apoptosis in early pregnant chorionic villi. Interleukin 1 beta converting
enzyme(ICE) expression and Fas expression in early pregnant villi and their
changes following mifepristone administration were detected by immunohistochmical
method and computer image analysis. During early pregnancy, ICE and Fas were
expressed in all component chorionic cells, predominantly syncytiotrophoblasts.
ICE stained cytoplasma. Fas stained mainly cytoplasma, and in partial
trophoblastic cells, Fas was expressed on membrane and nucleus. In the villi from
the pregnant women who received mifepristone for 2 days, expression of Fas
increased markely; the ratio of positive nuclear staining cells were
significantly raised, but the immunostaining intensity of ICE was slightly
increased. These results suggest that mifepristone may terminate early pregnancy
via increasing the expression of Fas and promoting apoptosis in the chorionic
villi.
PMID- 10684021
TI - [Study on enzyme-linked immunosorbent assay for cholecystokinin].
AB - This study was undertaken to develop a method for assaying octapeptide
cholecystokinin (CCK-8) using ELISA. The design of the method was based on the
pretreatment of polystyrene microplates with ultraviolet irradiation and
glutaraldehyde activation piror to coating. The results showed that this
pretreatment let to stable attachment of CCK-8 to the solid-phase. Competitive
ELISA with CCK-8 as a competitor gave excellent quantitive relationship. Using
this method we distinguished two kinds of CCK-related peptides. This method
proved to be simple, stable and reproducible, the intra- and inter-assay
coefficients of variation were 4.75% and 7.80% respectively.
PMID- 10684022
TI - [Application of antigen linked with chemicals on nitrate cellulose membrane for
dot-enzyme immunoassay].
AB - HCMV-IgG in sera of pregnant women was detected by means of dot-enzyme
immunoassay (DEIA), in which antigen was cross-linked on nitrate cellulose
membrane through chemical reagent. The results showed better repetition by DEIA,
compared with ELISA, and no significant differences were noted between the two
methods in the rates of detecting HCMV-IgG in positive, weak positive and
negative sera. The rate of agreement was 93.2%. In examining the sera which had
been examined by ELISA for three times with the same, results the sensitivity,
specificity, index and efficiency of diagnosis by DEIA were 100%, 96.6%, 196.6%
and 98.7% respectively. Since this method is convenient, fast, of good
repetition, economical and its diagnosis index meets the application criterion,
it is more suitable for clinical laboratories.
PMID- 10684023
TI - [DNA polymorphisms of apolipoprotein A I gene in Chinese endogenous
hypertriglyceridemics].
AB - The restriction fragment length polymorphisms (RFLPs) of apolipoprotein(apo) A I
gene were studied using polymerase chain reaction (PCR) in 69 endogenous
hypertriglyceridemics (HTG) and 74 healthy subjects from a population of Chinese
Han nationality in Chengdu area. The loci studied included Msp 1 within intron 3
of the apo A I gene; Xmn I, 5' to the apo A I gene; and Pst I, 3' to the apo A I
gene. The results showed that both in HTG group and control group M1, X1 and P1
alleles were the major alleles and homozyous M1M1, X1X1 and P1P1 genotypes were
the most frequent ones. The frequencies of rare M2 and X2 alleles in Chinese were
significantly higher than those in European Caucasians (0.293 vs 0.111, P <
0.0006, 0.286 vs 0.130, P < 0.004), but no differences were found in the
frequency of rare P2 allele (0.071 vs 0.046, P > 0.05). The frequency of rare M2
tended to increase in the HTG group when compared with the control group (0.353
vs 0.275, P > 0.05). Both in the HTG group and control group, subjects with
genotype M2M2 had a higher serum mean concentration of TC, apo C II and higher
serum TG/HDL-C ratio compared with the subjects with the genotypes M1M1 and M1M2
(P = 0.05, P < 0.03, P < 0.04), and the serum TG, apo C II and apo E levels had a
tendency to increase. The subjects with the genotypes P1P2 and P2P2 had a higher
serum apo A II levels compared with the subjects with the genotype P1P1 (P <
0.04). The data show that the only Msp I RFLP within the intron 3 of apo A I gene
is associated with endogenous hypertriglyceridemia to some extent in Chinese
population.
PMID- 10684024
TI - [Immunoblots of hydrophobic OmpL39 of Leptospiral interrogans with
immunoprotective Mb E4B7G5].
AB - The immunoprotective Mb E4B7G5 against outer membrane antigens from L.
interrogans serovar Lai strain 017 were produced and used in immunoblots of the
OMP of six strains of L. interrogans (017, 601, 603, 609, 620 and 245). The OMP
from the six strains, which partitioned into the hydrophobic detergent phase,
contained four-seven major proteins bands of 66 kd-16 kd. It was found that Mb
E4B7G5 recognized only specifically the 39 kd antigenic band of strain 017, 601,
603 and 609, and did not recognize apparently any bands of strains 620 and 245.
The findings suggest that Mb E4B7G5 be valuable for separating protective antigen
of OMP and studying genetic vaccines.
PMID- 10684025
TI - [Microvasculature of islets in human pancreas].
AB - The microvasculature of islets was studied by light microscopy with ink-injection
and scanning electron microscopy with vascular casts respectively in 11 human
pancreas. The results revealed that most of the islets were supplied by the
branches of the intralobular artery directly. The islets appeared in 3 types
(central type, peripheral type and mixed type) characterized by the site where
the afferent vessels entered the islets. Two (convergent and continuous) patterns
of portal vessels were found according to their calibre and length. Some of the
small islets were supplied by the efferent vessels of the adjacent large islets,
and the vessels connecting the large and small islets were called insulo-insular
portal vessels.
PMID- 10684026
TI - [Acupoints specificity in promoting the plasticity of cat spinal lamina II with
acupuncture-quantitative EM study].
AB - Our previous studies have shown acupoints stimulation might promote the
plasticity of spinal cord. In order to explore the acupoints specificity of the
effects we used ten cats with unilateral dorsal partial rhizotomy (L1-S2, except
L6). The rhizotomy sides of five cats received acupuncture stimulation (acupoints
stimulation group) at Zusanli (St36), Xuanzhong (GB 39), Futu (St32) and
Sanyinjiao (Sp 6) in the innervated areas of L6 spinal nerve for two courses, 10
days per coure. The rest cats were subjected to needling at the areas adjacent to
the acupoints (nonacupoints stimulation group). Quantitative EM method was
applied to detect (the population of synaptic terminals in lamina II 30 days
postoperation. According to the number of synaptic contacts between synaptic
terminal and postsynaptic element, synaptic terminals were divided into two
types: the simple terminal (ST) coming from spinal and descending tract, and the
complex terminal (CT) from dorsal root. The average numbers of the two types'
synaptic terminals per photo were compared directly because the acupoints and
nonacupoints groups' transverse areas of lamina II showed no significant
difference. The results showed: (1) There was no significant difference for ST
number between two groups. Associated with our previous study that acupoints
stimulation did not influence ST number, the present result indicated that
nonacupoints stimulation had no effect on ST number, (2) The complex terminal
numbers were statistically different (P < 0.05). The percentage of CT in the
nonacupoints group was only 53% of that in the acupoints group. This result was
similar to two other nonacupuncture groups in our laboratory (the percentages
were 59% and 62% respectively). It indicates that the effect of nonacupoints
stimulation is similar to that of nonneeding, i.e. nonacupoints stimulation does
not promote the plasticity of spinal lamina II or there might be acupoints
specificity in promoting the plasticity of spinal laminal II.
PMID- 10684027
TI - [L-arginine and nitric oxide have effects on glomerulus hyperperfusion of early
diabetic rats].
AB - We used streptozotocin (STZ) to induce the animal model of diabetes mellitus in
rats. On the 7th and 14th days of induction, kidney disorder, the levels of NO3-
in plasma and tissue homogenate in different periods were observed. The NO3-
levels in relation to the application of L-arginine (L-Arg) were also noted. The
results showed that the kidney weight/body weight ratio significantly increased
in different periods (P < 0.05). On the 7th day profuse proteinuria appeared and
it markedly increased on the 14th day: creatinine clearance rate (Ccr)
significantly raised, too (P < 0.005). The NO3- levels in plasma and tissue
homogenate were getting higher with time. The level of NO3- significantly
increased after L-Arg was perfused. It indicated that kidney disorder was present
at the early stage of diabetes, and the raised Ccr indirectly indicated the
increase of glomerular filtration rate. These suggest that NO3- and L-Arg may be
important mediums which have effects of hyperfiltration and hyperperfusion of
glomerulus.
PMID- 10684028
TI - [Experimental study of hypoxic pulmonary hypertension induced by nitric oxide in
rats].
AB - This experiment in rats was designed to investigate the effect and mechanism of
nitric oxide (NO) in the induction of hypoxic pulmonary hypertension. The plasma
concentrations of NO in normal controls and in the 1-, 2- and 3-week hyporemic
ventilation groups were measured. The hemodynamic and pathological changes were
observed in rats of the 2-week group after bolus injection of L-Arginine and NG
nitro-L-arginine. The results showed that NO concentrations of the 1-2- and 3
week groups were 5 +/- 2.67 mumol/L 2.1 +/- 0.41 mumol/L and 0.5 +/- 0.16 mumol/L
respectively, which were significantly lower than the control group's 6.73 +/-
1.83 mumol/L (P < 0.05). Bolus injection of L-Arginine 100 mg.kg-1.d-1 could
relieve chronic hypoxic pulmonary hypertension and decrease the thickening of
pulmonary arteries, but L-NNA could antagonize the effect of L-Arginine. This
experiment demonstrates that chronic hypoxemia may decrease the release of NO and
result in pulmonary hypertension. L-Arginine may be used to relieve pulmonary
hypertension, but L-NNA may antagonize the effect of L-Arginine.
PMID- 10684029
TI - [Effect of different hypoxic duration on changes of pulmonary circulation].
AB - In order to assess the relationship between the hypoxic duration and pulmonary
hypertension, we investigated the pulmonary hemodynamics and right ventricular
hypertrophy and pulmonary vascular structure changes in rats with hypoxic
exposure for 1 day to 3 weeks. After hypoxic treatment, the pulmonary artery
pressure of rats increased in 3 days, and it was up to peak at 2 weeks later. The
weight of right ventricle of rats significantly increased after 1 week. The
endothelium of pulmonary vascular of rats became swollen in 3 days, and then
increased in extracellular matrix deposition. Vessel wall thickening was found in
1 week hypoxic rats, and it was very significant in 3 week hypoxic rats. The
results suggest that the duration of hypoxic treatment is related to the change
of pulmonary circulation in 3 weeks in rats.
PMID- 10684030
TI - [Study on PHSAr gene expression of HBV in normal human hepatocytes].
AB - Based on the sequence of Hepatitis B Virus (type adr) (HBV) Pre S2 region, we
synthesized a pair of PCR primers. After a test of specificity, the primers were
employed to amplify the postulated transcripts of PHSAr gene in the liver samples
of 3 normal human subjects. By RT-PCR and RNA-PCR, all amplification results were
positive, while those from corresponding skeleton muscle controls were negative.
It suggests that HBV Pre S2 region should be to some extent homologous to PHSAr
gene exon(s). It also indicates that PHSAr gene is in expression at
transcriptional level, but not in expression in tissues (e.g. skeleton muscle) un
susceptible to HBV infection. Our data further confirm the role of PHSAr in HBV
infection of hepatocytes, compared with those from membrane receptor researches.
PMID- 10684031
TI - [The expression of tumor suppressor gene p53 and Rb gene in nasopharyngeal
carcinoma].
AB - In order to observe the relation of tumor supperssor gene p53 and Rb gene to
nasopharyngeal carcinoma, we investigated p53 gene mutations in exon 7-8 in 33
cases of nasopharygeal carcinoma (NPC), using single-strand conformation
ploymorphism analysis of PCR (PCR-SSCP). The data showed p53 mutations in 7 of 33
specimens at exon 8 (21.2%). No mutation in exon 7 was detected. Analysis of Rb
gene in NPC tissues by southern blot revealed the deletion and loss of activity
of Rb gene in 11 of 13 cases (86.6%). Our results suggest that Rb gene and p53
gene are closely associated with the tumorigenesis of NPC.
PMID- 10684032
TI - [Relationship of primary pulmonary carcinoma with P16 protein expression].
AB - This study sought to address the relationship of primary pulmonary carcinoma
(PPC) with P16 protein expression. The expression of P16 protein in 65 cases of
PPC was examined with immunohistochemical staining. The rate of loss of P16
protein expression in PPC was 36.92% +/- 18.45%. The rate of loss of P16 protein
expression in adenocarcinoma (AC) was 28.47 +/- 16.33%, that in squamous cell
carcinoma (SCC) was 35.95% +/- 17.36%, and that in adenosquamous cell carcinoma
(ASCC) 57.88% +/- 10.18%. There significant differences were in the rate of loss
of P16 protein expression between those aged < 60 with SCC and those aged > 60
with SCC, between low differentiated PPC and intermediate differentiated PPC,
between AC and ASCC, and between SCC and ASCC (P < 0.05). There were no
significant differences in the rate of loss of P16 protein between males and
females with PCC, between left and right PPC, and between PPC and metastatic
pulmonary carcinoma of lymph node (P > 0.05). These suggest that P16 protein
expression may be one of the important standards in estimating the prognosis of
patients with PCC.
PMID- 10684033
TI - [Successful 48-72 h cold storage of dog kidneys with HX-1 solution].
AB - HX-1 solution was used in this study to determine its effects on long term kidney
preservation. 20 female and male mongrel dogs were randomly divided into control
(HC-WCU solution) and experimental (HX-1 solution) groups. Kidneys were flushed
with HC-WCU or HX-1 solution and stored at 0.4 degree C for 48 or 72 h. After
being preserved, the kidney was implanted in the right groin of the animal and
anastomosed to the iliac vessles. This procedure was immediately followed by a
contralateral nephrectomy. The experimental findings were: 1. The maximum serum
creatinine levels were 642.60 +/- 158.60 mumol/L and 686.20 +/- 154.04 mumol/L
respectively in HC-WCU solution subgroups for 48 or 72 h cold storage. But the
maximum serum creatinine levels were 448.32 +/- 36.90 mumol/L and 524.60 +/-
109.38 mumol/L respectively in HX-1 solution subgroups. 2. 80% of the kidneys
were viable after 48 h storage in HC-WCU kidney solution, but 100% viable when
stored in HX-1 solution: 40% of the kidneys were viable after 72 h storage in HC
WCU solution, but 60% viable when stored in HX-1 solution. 3. Histologically the
kidney of dogs that died of renal failure was damaged worse in HC-WCU solution
group than that in HX-1 solution group. These results suggest that HX-1 solution
is superior to HC-WCU solution for preserving kidneys and HX-1 solution may store
up the kidney of dogs to 48-72 h.
PMID- 10684034
TI - [Expression of epidermal growth factor receptor in human duodenal ulcer].
AB - Expression of epidermal growth factor receptor (EGFR) was studied
immunohistochemically in 111 cases of human duodenal bulb biopsy. The results
showed that the expression of EGFR was strong on the luminal side of epithelial
cell membrane, moderate in the basolateral membrane of epithilial cells and the
cells of muscularis mucosae, low in the cytoplasm of the epithelial cells, and
lower in the mesenchyma and Brunner's gland. No expression of EGFR was found in
lymphoid aggregates. The expression was evidently stronger in duodenal ulcer and
duodenal ulcer scar. EGFR expression was correlated with the severity of
inflammation, but was not related to sex and age. In conclusion, the result
suggests that EGFR is correlated with mucosal adaptation to inflammation, ulcer
healing and tissue reconstruction.
PMID- 10684035
TI - [Histopathologic and immunochemical changes in Sjogren's syndrome].
AB - To research into the causes of sjogren's syndrome, we investigated the lacrimal
gland tissues of 6 cases of sjogren's syndriome by using electronmicroscopy and
immunochemical methods. The results revealed that at the early stage the lacrimal
gland cells showed degeneration, irregular arrangement and many intracellular
vacuoles. At the middle stage, some lymphocytes infliltrated into the gland
tissues. And at the advanced stage, lymphocytes and collagenous fibers were there
in substitution of gland cells.
PMID- 10684036
TI - [A study on interleukin-2 receptor genes in acute myeloid leukemia cells].
AB - To investigate IL-2 receptor (IL-2R) gene expression in acute myeloid leukemia
(AML) cells and the role of IL-2 in AML, the IL-2R alpha mRNA and IL-2R beta mRNA
in leukemic cells obtained from bone marrow of 41 cases with AML before
chemotherapy were measured by reverse transcriptase-polymerase chain reaction (RT
PCR). The responses to recombinant human IL-2 (rhIL-2) of these leukemic cells
expressing IL-2R mRNA from 8 cases were assayed by 3H-thymidine incorporation.
The IL-2R alpha mRNA and IL-2R beta mRNAs in leukemic cells were detected in 28
cases (68.3%) and 32 cases (78.0%), respectively. The IL-2R alpha mRNA and IL-2R
beta mRNA in leukemic cells of 21 cases (51.2%) were expressed simultaneously.
The responses to rhIL-2 of these leukemic cells from 8 cases were heterogeneous.
The responses to rhIL-2 appeared in three types: proliferation, inhibition and no
reaction. Only the cells of one case with M5 expressing IL-2R alpha mRNA and IL
2R beta mRNA responded proliferatively. The results demonstrate that the
expressions of IL-2R genes in AML cells are a general phenomenon. The responses
of these leukemic cells to rhIL-2 in vitro are heterogeneous.
PMID- 10684037
TI - [Maturation of bone marrow megakaryocyte in patients with chronic idiopathic
thrombocytopenic purpura].
AB - Colony formation units of megakaryocyte of twenty four patients with idopathic
thromboeytopentic purpura (CITP) were observed by plasma clot cultures in vitro.
We observed the maturation degree of megakarycyte and the effect of recombinant
interferon alpha-2a (rIFN-alpha-2a) on megakaryocyte colony growth and
maturation. The results showed that the number of CFU-MK of the patients with
CITP was greater than that of the control group, while the patients with normal
number of megakaryocytes on bone marrow smears had less BFU-MK and total clonies
than the controls had. Through image analysis, we found that the black level of
the positive cells of GP II a and GMP-140, the diameter and the area of
megakaryocyte of patients with CITP were lower or smaller than those of the
control group. These evidenced the block of megakaryocytopoiesis and megakarycyte
maturation. The growth of MK colonies of marrow of patients with CITP was
inhibited by r-IFN-alpha-2a.
PMID- 10684038
TI - [The relationship between female infertility and genital inflammation of
Chlamydia trachomatis].
AB - To address the relationship between female infertility and genital inflammation
of chlamydia trachomatis (CT), we took samples from the cervix and fallopian tube
of 147 cases of female infertility and investigated the rate of CT infection by
using polymerase chain reaction (PCR) assay. 60 cases of normal pregnant women
were chosen as controls. The results showed that in the infertile group the CT
positive rates for fallopian tubes and cervices were 15.66% and 22.45%
respectively, whereas in the control group the tubal positive rate was 3.33%.
There was significant difference between the two groups in tubal positive rate (P
< 0.05). Youngsters and workers were the high risk population of genital
infection of CT. These results indicate that genital infection of CT is an
important factor causing infertility; in that disease, the tubal infection of CT
is even more important. Besides the damage to tubal mucosa and smooth muscle, CT
infection causes tubal adhesion and obstruction. As a result it impairs the
function of the fimbriae and leads to infertility.
PMID- 10684039
TI - [Application of spectrophotometry to evaluation of the levels and the influence
of chemotherapeutic drugs on ATP of malignant cell lines].
AB - To evaluate the value of ATP spectrophotometry for malignant tumor in vitro
chemosensitivity test, Hela and L929 cell lines, which were derived from human
cervical carcinoma and mouse fibroma respectively, were investigated. The results
showed that when the cellular numbers were > or = 2 x 10(5), the linearity
between the ATP concentrations and the cellular numbers was observed, with all 2
cell types studied, and that when L929 cells were incubated with cis-platinum
(1x, 2x, 5x x plasma peak concentration, PPC), a marked fall in ATP
concentrations was observed and a clear dose-response curve was obtained, but no
decrease of ATP concentrations was measured after incubation with adriamycin (1x,
2x, 5x x PPC). This study suggests that ATP spectrophotometry is a cheap,
feasible method for studying the energy metabolism and the influence of
chemotherapeutic drugs on ATP concentrations of malignant tumor.
PMID- 10684040
TI - [Investigation of potency to produce interleukin-2 of the peripheral blood T
lymphocytes in patients with hemorrhagic stroke].
AB - For further understanding the changes in immune function of the patients with
hemorrhagic stroke, we investigated the activity of interleukin-2 (IL-2) in the
peripheral blood T lymphocytes from 32 patients. The results showed that the
levels of IL-2 in the patients were lower than those of the healthy controls, but
no significant difference was observed between the cerebral hemorrhage group and
subarachnoid hemorrhage group. It suggests the cellular immune function of
patients at the acute period is low. We consider that IL-2 might be of use as a
kind of therapeutic measure to modulate patients' immune function and treat the
diseases.
PMID- 10684041
TI - [Development of an expert system for assessment of criminal responsibility
capacity of mentally ill offenders].
AB - The objective of this study was to develop an expert system for the assessment of
legal capacity (ESALC). Visual Basic for Windows 3.0 was employed in establishing
ESALC, and 281 cases were assessed by the system. The results were in substantial
agreement with those of expert assessment. Kappa = 0.68 (P < 0.01); accuracy
90.04%, sensitivity, 85.63% and specificity 96.49%. ESALC can be used as a
supplementary instrument in forensic psychiatric assessment.
PMID- 10684042
TI - [The residue and degradation of herbicide ammonium 2,4-dichloro-6-nitrophenate in
the system of wheat and soil].
AB - To study the residue and degradation of ammonium 2, 4-dichloro-6-nitrophenate (a
herbicide) in wheat and soil, a field test was made in Wuxi Jiangsu of East China
and Chengdu Sichuan of West Chain during 1985-1992. The results showed that
ammonium 2,4-dichloro-6-nitrophenate was unstable with a half-life of 12-18 days
in soil. The residue in wheat was less than 0.05 mg/kg on the field doses
recommended. These results may be used as a basis for the hygienic evaluation of
ammonium, 2,4-dichloro-6-nitrophenate.
PMID- 10684043
TI - [Primary study on the sensitivity of cytokinesis blocked micronucleus assay in
CHL cells].
AB - Studies were performed to determine the cytochalasin B induced binucleated cell
percentage influenced by clastogens and aneuploidgens and to compare the efficacy
of cytokinesis blocked binucleated cells for scoring micronuclei with that of the
conventional mononucleated method following the treatment with mitomycin C,
methyl methanesulforate, colchicin and chloral hydrate. The results showed that
mitomycin C decreased the binucleated cell percentage induced by cytochalasin B,
whereas colchicin increased the frequencies of binucleated cells. The frequencies
of micronuclei in binucleated cells were not significantly higher than those in
the conventional mononucleated cells. The results suggest that cytokinesis
blocked method is not more sensitive than the conventional method for scoring
micronuclei. The factors that may influence the cytokinesis blocked micronucleus
assay have been discussed.
PMID- 10684044
TI - [The relationship between pulmonary function and work ability of aging workers].
AB - To explore the relationship between pulmonary function and work ability, a field
study was conducted in 285 aging workers (aged 40 to 60) of different occupations
in Chengdu area. The pulmonary function indices included FVC, FEV1, FEV1%, MMEF,
and the pulmonary function index (PFI) which was the sum of the rating values
from the first three indices. The work ability index (WAI) was also measured.
Between work types, the indices, including FVC and FEV1%, showed significant
difference (P < 0.05); FVC also showed significant difference between male and
female workers (P < 0.05). There was a significant relationship between PFI
(including FEV1% and MMEF) and WAI (P < 0.05), but the relationship between FVC
(or FEV1) and WAI was not statistically significant (P > 0.05). Moreover, the
agreement percentage between the classifications of PFI and WAI was 43.8%; the
disagreement percentage was 4.56%. The results suggest that FEV1% and MMEF may be
beneficial to the objective evaluation of the work ability of aging workers.
PMID- 10684045
TI - [Electron spin resonance studies of the oxidative denaturation of hemoglobin of
blood preserved at 35 degrees C].
AB - Studying the denaturation of oxidative hemoglobin of blood preserved at room
temperature, it is helpful to overall understand erythrocyte injurious during
blood preserved at room temperature. Using electron spin resonance technique, we
have researched the denaturation of oxidative hemoglobin of blood preserved at 35
degrees C. We discovered that blood preserved at 35 degrees C, appears ESR
absorption of high spin methemoglobin (g = 6) after preservation time is 36
hours. The high spin methemoglobin ESF absorption will increase when preservation
time increases. When blood is preserved at 4 degrees C, it dose not emerge ESR
absorption during 60 hours preservation. SOD activity will gradually decline in
erythrocyte of blood preserved at 35 degrees C when preservation time increases.
Oxidative denaturation of hemoglobin is probably caused with gradual declining of
antioxidation system effect in erythrocyte.
PMID- 10684046
TI - [Resistant antibiotic analysis of methicillin-resistant staphylococcus].
AB - Methicillin-resistant staphylococcus aureus is one of the important patholonic
bacteria which cause nosocomial infection. In order to investigate the resistant
antibiotic circumstances of this organism and hence provide foundations of
prevention and treatment, we determined the resistant rates of 88 staphylococcus
strains for methicillin and for other 14 kinds of commonly used antibiotics, and
we determined the engendering beta-lactamase. The results showed that the
isolation rate of methicillin-resistant staphylococcus aureus (MRSA) was 56%; the
rate of methicillin-resistant staphylococcus coagulase-negative (MRSCoN) was
47.6%; the resistance rate and the multi-resistant rate of methicillin-resistant
staphylococcus (MRS) for the 14 kinds of antibiotics were higher as compared with
those of methicillin-sensitive (MSSA). Among all the tested strains, MRSA was the
highest to engender beta-lactamase (92.9%); Methicillin-sensitive staphylococcus
coagulase-negative (MSSCoN) was the lowest (39.4%). MRS was sensitive to
vancomycin and furantoin. These suggest that when treating this bacterium, we
should select these two antibiotics first.
PMID- 10684047
TI - [Non-parametric testing for independence in data].
AB - In this paper, we have discussed the important effects of data independence on
statistic results, and have explained in detainl the non-parametric testing for
independence, which can facilitate medical researchers to use statistical methods
for solving their problems.
PMID- 10684048
TI - [Studies on the essential oil constituents of the stem bark of Magnolia obovata].
AB - For the extensive studies of the chemical constituents of Magnollis obovata, the
essential oil from Magnolia obovata was obtained by steam distillation. The
chemical components of the oil were examined by means of capillary gas
chromatography and gas chromatography-mass spectrometry. 29 of the 75 separated
constituents were identified. The content of each component identified was
determined by area normalization method, which showed the content of 9 compounds
was higher than 1%.
PMID- 10684049
TI - [Optimization of quenching system for determination of emodin and chrysophanol by
chemiluminescence method].
AB - Determination of the valid components in traditional Chinese medicine is one of
the key steps for its identification, and the development of accurate and simple
methods is necessary for the present analysis work of medicines. In this paper,
the experimental conditions were optimized and procedures chosen for
determination of emodin and chrysophanol by lunminol-H2O2-Cr3+ chemiluminescence
quenching system. The dynamic range for determination of emodin was 10(-4)-10(-8)
g/ml (r = 0.9965), with a detection limit of 1.57 x 10(-9) g/ml. The RSD and
recovery for determination of 10(-7) g/ml of emodin (n = 6) were 0.4% and 92.8%
+/- 0.5%, respectively. Satisfactory results were also obtained when the method
was used to determine chrysophanol. This method was used, after separation by
thin layer chromatography, to determine emodin and chrysophanol in several
traditional Chinese patent medicines, and the results were in good agreement with
those obtained by the standard colorimetric method.
PMID- 10684050
TI - [Adsorption of permanganate onto activated carbon particles].
AB - In this paper, the adsorption behavior of permanganate onto activated carbon
particles was studied as a function of pH, flow rate and the concentration of
permanganate. It was found that permanganate was not adsorbed but reduced by
activated carbon particles. The percent of reduction of permanganate was strongly
pH-dependent. The reducing product of permanganate was mainly Mn2+ which was
adsorbed onto the activated carbon particles by surface complexation.
PMID- 10684051
TI - [Oxidative modification of serum LDL, VLDL and HDL induced by fed on high
cholesterol diet in vivo in rabbits].
AB - Many lines of evidence suggest that LDL is oxidized in vivo and that ox-LDL is
present in the artery wall. But the oxidation of VLDL and HDL in vivo has not
been reported yet. A study on effects of high cholesterol diet on oxidative
modification of LDL, VLDL and HDL in rabbits was made. The control group (n = 8)
was fed on routine diet, and the experimental group (n = 8) on high cholesterol
diet (routine diet supplemented with 5% lard, and 0.5 g cholesterol a day for
each rabbit) for 12 weeks. The serum LDL, VLDL and HDL were isolated by the
density gradient ultra centrifugation. The oxidative modification of LDL, VLDL
and HDL was identified by agarose gel electrophoresis, absorbance at 234 nm and
fluorescence of TBARS. The results showed that serum TC, TG and TBARS in the
experimental group were significantly higher than these of the control group (P <
0.01). The electrophoretic mobility of LDL, VLDL and HDL was increased, and
absorbance at 234 nm and TBARS of LDL, VLDL and HDL in the experimental group
were significantly higher than these of the control group (P < 0.01). These
results suggest that not only LDL but also VLDL and HDL were oxidatively modified
in vivo in rabbits after fed on high cholesterol diet.
PMID- 10684052
TI - [Serum apolipoprotein C II, C III and E levels in 437 male healthy subjects aged
40-70 in Chengdu area].
AB - Apolipoprotein (apo) C II, C III and E levels of 437 male healthy subjects aged
40-70 [with fasting serum triglyceride (TG levels < 2.26 mmol/L, total
cholesterol (TC) levels < 6.21 mmol/L and plasma glucose levels < 6.10 mmol/L] in
Changdu area were determined by radial immunodiffusion assay (RID). The results
showed that the concentrations of apoC II, C III and E were 41.6 +/- 13.1, 112.8
+/- 31.0 and 38.7 +/- 8.2 mg/L (mean +/- s) respectively. No difference in the
serum levels of apoC II, C III and E was noted between the men of different ages.
The results of the linear correlation showed that there was a positive
correlation of apoC II, C III, E with TG, TC, LDL-C; of apoC II, C III with BMI;
and of apoE with ages.
PMID- 10684053
TI - [The serum lipid and apolipoprotein levels of middle-aged male hyperlipidemics in
Chengdu district].
AB - It has been evidenced that cardiovascular diseases (CVD) relate with many risk
factors and serum lipids play and essential role in the development of CVD. In
order to further study hyperlipidemia (HL) in the middle-aged males, we analysed
the body mass index (BMI), fast blood sugar (FBS), serum lipids and
apolipoproteins A I, A II, B100, C II, C III and E in 223 male HL patients aged
41-60 and 349 normal male subjects who matched the HL patients in age. The result
showed that the increase of serum triglycerids (TG), was as might be expected,
the major characteristic of the middle-aged male HL patients in Chengdu District.
Besides the serum lipid and apolipoprotein B100, C II, C III and E levels, the
BMI and FBS levels in the IIb, IV and V types of HL patients were significantly
higher than those in the normal subjects. It also showed that in TG increased
patients the increased percentages of serum lipids were significantly higher than
those of apolipoproteins. The age distribution in HL patients revealed that only
25% of the HL patients were between 41 to 50 years old, while 50% in the 56-60
year-old group. The relationship between apolipoprotein levels and serum lipid
metabolism is also discussed. The results suggest that the 51-60 year-old males
should pay attention to diet and increase physical activities to reduce incidence
of HL which is directly associated with CVD.
PMID- 10684054
TI - [Relation of serum apolipoprotein B100 levels to lipids and apolipoproteins A I,
A II, C II, C III and E levels in the middle and old age normal males in Chengdu
area].
AB - This study was conducted in 438 normal men aged 40-70. The age groups were: 40
44, 45-49, 50-54, 55-59, 60-64, and 65-70. The results showed that the serum
apolipoproteins levels (mean+/- s, mg/L) were: B100 levels 742.5 +/- 165.8, A I
1301.2 +/- 219.9, A II 299.4 +/- 49.0, C II 42.7 +/- 21.4, C III 113.3 +/- 34.0
and E 38.7 +/- 8.2. The levels of serum apoB100 increased with age. The serum
apoB100 levels in the 5th and 6th age groups were significantly higher as
compared with the groups 1, 2, 3 and 4 (P < 0.05 and P < 0.05). The fasting serum
mean TG (1.39 +/- 0.45 mmol/L), TC(4.79 +/- 0.82 mmol/L) and LDC-C(1.62 +/- 0.40
mmol/L levels in the groups 5 and 6 were significantly higher as compared with
the groups 1, 2, 3 and 4 (P < 0.01). Serum apoC II, C III and E levels were
significantly increased in the groups 5, 6 (P < 0.05). The correlation analysis
indicated that there was a positive correlation of apoB100 with serum TG, TC, LDL
C, apoC II, C III and E respectively (P < 0.01); and a negative correlation with
HDL-C levels (r = 0.1312); and apoB100 correlated negatively with apoA I (r =
0.0706). The results suggest that serum TG, TC, LDL-C, apoC II, C III and E are
the main factors related with the serum apoB100 levels.
PMID- 10684055
TI - [Construction of genomic library of L. interrogans serovar lai using lambda gt11
as the vector and a study of recombiant plasmid pDL121].
AB - A genomic library of L. interrogans serovar lai strain 017 has been constructed
using lambda gt11 as the vector. DNA was partially digested by two blunt-end
restriction enzymes, then methylated with EcoR I methylase; after EcoR I linker
was added to the DNA, the linker-ended DNA was ligated to the dephosphorylated
EcoR I digested lambda gt11 arms. The recombined DNA was packaged in vitro, and
used to transduct E. coli Y1090 for amplification. There were 2.1 x 10(6)
recombinant bacteriophages as recognized by their ability to form white plaques
plated on Lac host in the presence of both IPTG and X-Ga1. A positive clone,
designated lambda DL12, was screened with a rabbit anti-serum against L.
interrogans serovar lai from the genomic library. The DNA from lambda DL12 was
subcloned into plasmid pUC18. A recombinant (designated as pDL121) was obtained.
SDS-PAGE analysis indicated that a 23 kd was expressed in E. coli JM 103
harboring pDL121. Western blotting analysis showed that a specific protein band
molecular weight of 23 kd could be recognized by the rabbit antiserum against L.
interrogans serovar lai strain 017.
PMID- 10684056
TI - [Circadian rhythm of PGE2 level in plasma and condylar cartilage of young growing
rats].
AB - This paper reports the circadian rhythm of PEG2 level in plasma and condylar
cartilage of young frowing rats. The samples were measured at 0:00, 4:00, 8:00,
12:00, 16:00, and 20:00 respectively. The count of PGE2 were determined by RIA
and analysed with simple Cosinor and coordination. The results revealed: (1) The
levels of PGE2 in plasma and condylar cartilage of young growing rats fluctuated
in strong circadian rhythm; (2) The rhythm of PGE2 in plasma between 16:00 and
24:00 was significantly different from that between 4:00 and 12:00, so for
analysing PGE2 level in plasma, one should proper sampling time or adjust it to
circadian rhythm; (3) The circadian rhythm of PGE2 in condylar cartilage could
provide important reference for reatments in dentistry and orthopaedics.
PMID- 10684057
TI - [Effects of estrone on transmission at neuromuscular junction of the toad].
AB - The effects of estrone on neuromuscular transmission were studied intracellularly
at the muscle fiber endplate in isolated sciatic nerve-sartorius muscle
preparations of the toad (Bufo bufo gargarizans) in vitro. The results showed
that estrone (10(-4) mol/L), added to bath medium, caused an increase in
amplitudes of endplate potentials (EPP) both in 10 micrograms tubocurarine
treated and 10 mmol/L MgCl2 treated preparations, but the increase was more
prominent in the former, and that estrone, 30 min after being added to bath
medium, caused clear increase both in frequency and amplitude of miniature
endplate potentials (MEPP), but the wave form of MEPP remained unchanged and the
resting membrane potentials were also unchanged. These results suggest that
estrone can increase neuromuscular transmission, which seems to involve primarily
the presynaptic mechanism.
PMID- 10684058
TI - [Effects of L-glutamic acid, gamma-aminobutyric acid and their respective
antagonists on spontaneous discharge of nucleus paragigantocellularis lateralis
neurons in rats].
AB - Using multibarrel microelectrode techniques, we studied the effects of
iontophoretic application of L-glutamic acid (L-Glu), gamma-aminobutyric acid
(GABA) and their respective antagonists DL-2-amino-5-phosphonovaleric acid (AP5),
bicuculline (BIC) on the spontaneous discharge of the caudal half of nucleus
paragigantocellularis lateralis (cPGCL) neurons (including respiratory related
neurons) and the influences of AP5 and BIC on the effects of L-Glu and GABA
respectively in 22 anesthetized spontaneously breathing Sprague-Dawley rats. The
spontaneous discharges of all the cPGCL neurons tested were inhibited by GABA(n =
53). Most of the tested neurons were excitated by L-Glu (30/36). AP5 and BIC both
showed three kinds of effects on the cPGCL neuronal spontaneous discharge;
excitatory, inhibitory and no-effect. The excitatory effects of L-Glu and BIC and
the inhibitory effects of GABA showed a dose-response relationship. AP5 could
block partially the excitatory effect of L-Glu on a large part of neurons tested
(14/19). BIC blocked, partially or completely, the inhibitory effect of GABA also
on a large part of the neurons tested(18/24). The results implicate that there
might exist endogenous L-Glu and GABA acting as neurotransmitters in the cPGCL
area and excitatory amino acids (EAA, including NMDA and non-NMDA) and GABA
receptors on cPGCL neurons. These neurotransmitters and receptors may mediate the
regulatory action of cPGCL on respiration and other functional systems.
PMID- 10684059
TI - [Alkaloid production of cultured coptis cells by two-stage suspension-culture].
AB - In this study the asexual cell line H292 induced and selected from Coptis
gulinensis had rapid growth rate and could stably produce alkaloids. By the one
stage method, after the cell suspensions were cultured on the same medium for six
weeks, the increased dry and fresh weights of the cells were 20.96 g/L and 174.92
g/L respectively. The content of the total alkaloids in the cells was 14.79 mg/g
cell dw. Per litter liquid medium could provide 323 mg alkaloid. In contrast, the
cells were cultured by two-stage method. After having been cultured on the medium
which contributed to the growth of the cells for three weeks, the cells were
transferred to the medium which contributed to the production of the alkaloid and
cultured for three weeks. Six weeks later, the dry and fresh weights of the cells
were 16.72 g/L and 127.44 g/L, respectively. The biomass was lower than that by
one-stage method, but the content of the total alkaloids was as high as 31.76
mg/g cell dw, which was much more than that by one-stage method. In addition, the
content of the alkaloid in the medium was 25.31 mg/L. Per litter liquid medium
could provide 556 mg alkaloid. The total yield of alkaloid obtained by two-stage
method was 1.72 times than that by one-stage method.
PMID- 10684060
TI - [Expression of metastasis-suppressor gene nm23H1 product in nasopharyngeal
carcinoma].
AB - Using the specific monoclonal antibody of nm23H1 gene product and the
immunohistochemical technique, we studied the expression of DNPK/nm23H1 and its
correlation with lymph-node metastasis in nasopharyngeal carchnoma (NPC). The
results revealed that, in a total of 31 cases of NPC, 13 showed positive
expression with a positive rate of 41.9%. Among 21 cases of NPC with no lymph
node metastasis, 11 (52.3%) showed positive expression while only 20% (2/10) of
those with lymph-node metastasis were positive, and there was significant
difference between them (P < 0.01). Meantime the expression was very low or not
detectable in the cancerous cells of the match lymph-node metastasis and all 10
cases showed negative expression. Statistical significant difference was found
between the group of NPC with no metastasis and the group of lymph-node
metastasis (P < 0.01). The above results indicated that high expression of
DNPK/nm23H1 existed in the group of NPC with no metastasis while low expression
existed in those with metastasis and lymph-node metastasis. It suggests that the
expression of nm23H1 is inversely associated with lymph-node metastasis. The
DNPK/nm23H1 may play a role in polymerization of microtubulin protein and
participate in the process of cancer metastasis.
PMID- 10684061
TI - [PCR-SSCP analysis of p53 gene in human primary brain tumor].
AB - In this study PCR-SSCP alalysis was made to detect the mutation of the exon 5-7
of p53 gene in 37 cases of human primary brain tumor. The results showed that 10
human primary brain tumors had mutation, of which 9 were gliomas (37.5%) and 1
was meningioma (7.7%), and that the higher the grade of tumor was, the higher
would be the frequency of mutation. These results suggest that human primary
brain tumor is related to p53 gene mutation and such mutation may be the major
reason for human primary brain tumor genesis and malignancy.
PMID- 10684062
TI - [Detection of p53 gene mutations in hepatocellular carcinoma].
AB - This study screened 32 cases of hepatocellular carcinoma (HCC) from Chengdu
detecting HBV DNA. HBsAg and p53 mutations by using Southern blot hybridization,
immunohistochemistry and polymerase chain reaction/restriction enzyme digest
methods, respectively. The results revealed all the cases had been infected by
HBV; the frequency of HBV DNA integration into HCC cell was 72%, and the positive
staining for HBsAg 96.3%(26/27). Of the 32 cases, 8 showed nuclear staining of
p53 protein (25%), no mutation of p53 gene at all in 27 nontumorours liver
tissues was identified. The resluts suggest the inactivation of p53 function may
play a significant role in the genesis of HBV-associated HCC; however, the
largely negative p53 mutation results in the current study conversely indicate
that hepatocarcinogenesis may even involve other comprehensive mechanisms.
Further studies are worth doing to evaluate the possible contribution of HBV to
the p53 mutation in HCC.
PMID- 10684063
TI - [An analysis of acute leukemia cells TfR expression in children].
AB - There are a lot of transferrin receptors on the acute leukemia cells. We used the
method of "Receptor Radioligand Assay" to determine the numbers of TfR binding
sites on leukemia cells from 20 child patients with acute lymphocyte leukemia
(ALL) and 9 with acute myeloid leukemia (AML). The results showed the numbers of
TfR binding sites of AML cells were higher than those of ALL cells, and the
numbers of complete remission group were lower than those of dead or relapse
group. This indicated there might be a relationship between the TfR expression
and the prognosis.
PMID- 10684064
TI - [The anti-inflammatory effects of superoxide dismutase].
AB - This paper reports the anti-inflammatory effects of superoxide dismutase (SOD)
from pig blood on inflammatory animal models. The experimental results have shown
that SOD has significant anti-inflammatory effects. It inhibited carrageenin
induced foot-edema and croton oil induced granulation tissue edema of rats. It
also inhibited arthritis induced by egg serum and Freund's adjuvant in rats. The
effects were significantly dose-dependent.
PMID- 10684065
TI - [The effect of Tianma injection on cultured vascular smooth muscle cells
proliferation].
AB - The proliferation of vascular smooth muscle cells (VSMC) has been thought to play
an important role in the development of hypertension and atherosclerosis. The aim
of this study was to investigate the effect of Tianma Injection and its major
component Gastrodin on the proliferation of cultured VSMC. VSMC were cultured and
randomly divided into the control, Tianma and Gastrodin groups. The results
showed that Tianma Injection significantly decreased cell numbers dose
dependently and time-dependently, and it inhibited 3H-TdR incorporation in VSMC.
It also increased the content of PGI2 production in VSMC. However, no significant
differences of the above measurements were observed between the Gastrodin and
control groups. The suggest that Tianma Injection can inhibit VSMC proliferation
and the effect possibly results from its increasing PGI2 production content, and
that the inhibiting effect of Tianma is irrelated to Gastrodin.
PMID- 10684066
TI - [A confirmatory analysis on the causation of osteoporosis].
AB - Bone width (BW, cm), bone mineral density (BMD, g/cm) and bone mineral density
(BMD, g/square cm) are three indexes to the mineral content of the bone. Since
the ways, methods and instruments measurement are usually not the same, exact
measurement of the three indexes could not be assured. Thus the results of data
analysis might not keep with the facts. We treated the three indexes as latent
variables, set up a linear structural relation model (LISREL) and hence confirmed
the causation of osteoporosis.
PMID- 10684067
TI - [Application of serum bile acid chromatography to the diagnoses of liver
diseases].
AB - In order to explore the specificity of serum bile acid (SBA) chromatograph in the
diagnoses of different kinds of hepatosis, we investigated by means of gas
chromatography the changes of serum bile acids in workers who exposed to hexogen
or chloroethylene and in patients who suffered from hepatosis such as acute
jaundice hepatitis, chronic active hepatitis, cirrhosis and liver cancer. The
results revealed different disturbances of SBA occurring in the liver injuries
induced by the two kinds of hepatotoxicant. Serum lithocholic acid (LCA),
deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA) in workers exposed to
hexogen and wre significantly different from those of the control group
respectively (P < 0.01, P < 0.01, P < 0.05); on the other hand, only serum LCA
and DCA went up in workers exposed to chloroethylene (P < 0.0005, P < 0.001). The
main changes both concentrated on the secondary bile acids. In acute jaundice
hepatitis, chronic active hepatitis, cirrhosis and liver cancer, serum LCA, DCA,
CDCA and cholic acids (CA) all went up in different degrees compared with the
control group respectively (P < 0.005, P < 0.025, P < 0.005, P < 0.005). But no
difference was noted among the 4 kinds of bile acids (P > 0.5), except that
between CA and CDCA. These provided the evidence of the diagnosis and
identification of clinical hepato-biliary diseases and occupational liver
injures.
PMID- 10684068
TI - [Effects of chronic hypoxia on calmodulin activity in rats].
AB - To investigate the effects of chronic hypoxia of calmodulin activity in rats, we
divided 40 wistar rats into four major groups. One group acted as control. The
other three groups were made hypoxic by placing them in an isobaric hypoxic
chamber (O2 = 10%) for 1, 2 and 3 weeks respectively. Calmodulin activity was
measured by Phosphodiesterase method. The results showed that the mean pulmonary
arterial pressure and the pulmonary vascular resistance in rats were remarkably
increased by chronic hypoxia. The total calcium levels and the calmodulin content
in the lung tissue of rats were significantly elevated at 2-3 weeks of hypoxia
exposure. However, the calmodulin content in the lung tissue of the rats exposed
to hypoxia for 1 week also increased, but it was lower than those at 2-3 weeks of
hypoxia exposure. Therefore, we conclude that Ca(2+)-calmodulin system may play a
central role in mediating hypoxai-induced pulmonary hypertension.
PMID- 10684069
TI - [Effect of methylphenidatum on inspiratory muscles function in patients with
chronic obstructive pulmonary disease and its mechanism].
AB - To have a better understanding of the effect of methylphenidatum on inspiratory
muscles function, we studied the respiratory force parameters of 70 patients with
chronic obstructive pulmonary disease by intravenous infusion methylphenidatum in
a randomized controlled clinical trial. The indices of respiratory force
parameter included maximal inspiratory mouth pressure (MIP), maximal
midinspiratory flow (MMIF), forced inspiratory capacity (FIC), maximal works of
inspiration (Wimax) and airway occlusion pressure (P0.1), etc. Aminophylline and
Nikethamidi were chosen as controls. The results showed that MIP, MMIF, FIC,
Wimax, P0.1 and minute ventilation (Vr) were significantly increased after
administration of methylphenidatum and aminophylline. There were no significant
differences in MIP, MMIF, FIC and Wimax after administration of Nikethamidi, but
P0.1 was significantly increased and the increase was higher than that after
administration of methylphenidatum and aminophylline groups. We conclude that
methylphenidatum can significantly improve the function of inspiratory muscles as
aminophylline can do.
PMID- 10684070
TI - [Changes of serum TNF-alpha level, t-PA activivty and PAI activity in patients
with silent myocardial ischemia or silent cerebral ischemia].
AB - Tumor necrosis factor-alpha (TNF-alpha) level, tissue-typed plasminogen
activator(t-PA) activity and PA inhibitor (PAI) activity were determined in three
groups: (1) 25 NIDDM patients with silent myocardial ischemia (SMI) or silent
cerebral ischemia (SCI); (2) 18NIDDM patients without SMI or SCI; (3) 20 age
matched normal controls. Diagnosis of SMI or SCI was based on the finding of
ischemic evidence by SPECT of myocardiotomograph or cerebrotomograph. All
patients ECG and blood pressure were normal, and they had no history of clinical
symptoms and signs of MI or CI. The result showed that the TNF-alpha level and
PAI activity in the ischemia group were the highest and the t-PA activity in the
ischemia group was the lowest, as compared with those in the other two groups
respectively. It suggests that in NIDDM patients who have high TNF-alpha, high
PAI activity, low t-PA, and even no symptoms and signs of MI or CI, anticoagulant
therapy might be useful to prevent the progression of diabetic macroangiopathies.
PMID- 10684071
TI - [The study on insulin secretion function of beta-cell in new diagnosed type II
diabetic patients].
AB - To determine type II diabetes in association with alteration in beta-cell
function, we studied 30 patients with newly diagnosed diabetes and 30 matched
controls. The beta-cell 1st phase insulin response was measured by intravenous
glucose tolerance test and the 2nd phase insulin response was measured by oral
glucose tolerance test. The results revealed that in type II diabetes mellitus
the pulse of 1st phase insulin secretion could not be found. The amount of 2nd
phase insulin secretion of the patients was lower than that normal controls, and
the patients' secretary pulse of insulin was not concomitant with glucose pulse.
These findings again suggest it is the defect in beta-cell function, not the
peripheral resistance an essential cause of overt type II diabetes.
PMID- 10684072
TI - [Prevention of acute hepatic failure after "90%" hepatectomy by portal branch
ligation in rats].
AB - In this study, ligation of portal branches feeding 90% liver mass was performed
in rats. After the ligation, 10% liver mass with portal blood perfusion underwent
a progressive hypertrophy. It gained weight against the control by about 5-fold
at the 14th day. The measurement of incorporation rate of H3-thymidine showed
that the DNA synthesis increased rapidly in the liver tissue keeping portal blood
supply. It reached a peak at 24 hours and retumed to normal at 7 days after the
ligation. The ligated liver lobes under-went an atrophy gradually. With the
pretreatment of such portal branch ligation 2 weeks before, 80% rats survived
from the resection of ligated liver lobes which composed of 90% preceding liver
mass. In the control group of sham portal branch ligation, all rats died within a
short period of time after 90% hepatectomy. This study demonstrated that a
secondary extended hepatectomy following the ligation of portal branches feeding
90% liver mass could prevent acute hepatic failure induced by primary 90%
hepatectomy in rats.
PMID- 10684073
TI - [Uterine activity in active phase].
AB - This study was designed to understand the uterine activity (UA) in normal labor.
43 nulliparous women(33 in normal course of labor and 10 in abnormal course of
labor) were in the active phase of spontaneous labor with cephalic presentation
for vaginal delivery. An open-end fluid filled intrauterine catheter connected to
a pressure transducer was used to measure the uterine contraction intensity,
frequency and duration. UA was quantified by means of Montevideo Unit (MU) and
Uterine activity integral(UAI). The receiver operator characteristic(ROC) curve
defined the cut-off points of UA between normal labor and abnormal labor. The
results showed that MU and UAI were correlated with the rate of cervial
dilatation in the active phase of labor (r = 0.3734 and 0.3502 respectively, P <
0.05). There was a strong correlation between MU and UAI (r = 0.7173, P < 0.001).
The mean of UA in normal labor as MU = 226(s = 68.45) mmHg/15 min. UAI = 901(s =
258.02) kPa/15 min. The minimum of UA to normal labor in MU was 170 mmHg/15 min,
of UAI 650 kPa/15 min. The study suggests that quantification of UA is very
useful in the management of labor, especially in the proper use of oxytocin in
cases abnormal labor.
PMID- 10684074
TI - [Evaluation on ISGP classification of endometrial hyperplasia in clinical
application].
AB - To evaluate clinical application of International Society of Gynecologic
Pathologists Classification of endometrial hyperplasia 424 patients with endome
trial hyperplasia were treated in our hospital from Sept. 1989 to Feb. 1995. Our
of these cases, 339 were simple hyperplasia, 28 were complex hyperplasia and 57
atypical hyperplasia. We made an analysis of the cases of complex and atypical
hyperplasia in terms of the ISGP classification. The total rate of curettage was
63.5%. The agreement rate for pathologic diagnoses before and after operation was
78%. Under the age of 40, 18 patients had atypical hyperplasia and 15 of them
underwent hysterectomy. Eight patients had complex hyperplasia and 3 of them
underwent hysterectomy. Above the age of 40, 39 patients had atypical hyperplasia
and 30 of them had uterus removed. Twenty patients had complex hyperplasia and 12
of them had uterus removed. These suggest that the ISGP pathologic diagnostic
method is good to avoid overdiagnosis and overtreatment. Yet, diagnostic
curettage is still the best means in diagnosis before operation.
PMID- 10684075
TI - [Perinatal monitoring in intrahepatic cholestasis of pregnancy].
AB - The sensitivity of meconium stain in amniotic fluid for prediction of fetal well
being in intrahepatic cholestasis of pregnancy(ICP) was evaluated. The study
consisted of an ICP group(n = 30), and a control group (n = 30) and the umbilical
arterial pH value(< 7.2) was used as a standard. The positive and negative
predicttive valus of meconium-stained amniotic fluid in ICP group were 80.0%; the
positive and negative predictive values in control group were 60.0% and 92.0%
respectively. There was no significant difference (P > 0.05) between the two
groups in positive and negative predictive values. However, the positive and
negative predictive values of the two groups were high, which indicated that
meconium-stained amniotic fluid related to fetal hypoxia. Moreover, the incidence
of meconium-stained amniotic fluid in ICP was higher than that in control (40.0%:
16.70%, P < 0.05). Therefore, we suggest that the amniotic fluid of patients with
ICP should be observed very closely. When meconium-stained amniotic fluid is
discovered, delivery by cesarean section is imminent.
PMID- 10684076
TI - [A three-month follow-up study of excimer laser photorefractive keratectomy for
myopia].
AB - In order to evaluate the efficacy of photorefractive keratectomy (PRK) in the
treatment of myopia, we summed up and analysed the 3-month follow-up data on 145
cases treated in our hospital. Prior to PRK, refractive dioptal was -1.5 to
11.5; visual acuity was less than 0.1 in 137 cases (94%) and less than 0.5 in 8
cases(6%). One month after operation, the mean refractive dioptal was +0.98 +/-
0.88; visual acuity increased to > or = 1.0 in 95 cases (66%) and to > or = 0.5
in 142 cases(98%). Three months after operation, the mean refractive dioptal was
0.13 +/- 1.09; visual acuity increased to > or = 1.0 in 104 cases(72%) and to >
or = 0.5 in 135 cases(93%). There was no severe complication noted in all cases.
The results demonstrate that PRK is and effective, safe and predictable treatment
for myopia.
PMID- 10684077
TI - [A study of 46 forensic autopsy cases of medical tangle].
AB - Forty-six forensic autopsy cases of medical tangle were investigated for
understanding the characteristic of medical tangle cases and for comparing the
consistency between clinical and pathological diagnoses. The age ranged from 6
days to 68 years. Women outnumbered men by ratio of 1.3:1. The most common
occupation was farming. The consistency between clinical and pathological
diagnoses was 34.78%. The causes of medical tangle and the difference between
clinical and pathological diagnoses were discussed.
PMID- 10684078
TI - [Quantitation of human apolipoprotein B100 by immunoturbidimetric assay].
AB - An immunoturbidimetric assay(ITA) for quantification of human serum
apolipoprotein B100 (apoB100) was developed. The assay is sensitive, rapid,
specific, easily automatic and thus convenient for routine work. The minimu
measurable concentration of apoB100 was 3.1 micrograms in each assay. The
standard curve with a working range of 0.34-1.79 g/L was plotted. The between and
within assay coefficients of variation were 1.13%-3.48% and 2.91%-4.48%
respectively. The recovery was 99.23% +/- 3.57%. The mean serum concentration of
apoB100 in 100 normal subjects was 0.821 +/- 0.165 g/L. The correlation
coefficient of RID for apoB100 to ITA was 0.8626(P < 0.001).
PMID- 10684079
TI - [A newly developed equipment for cleaning of sample tube used in nuclear magnetic
resonance experiment].
AB - Cleaning sample tubes used in nuclear magnetic resonance experiment is a time
consuming work. We developed a new type of equipment based on fluidics for
cleaning those sample tubes and successfully solved the problem. For several
years of application, the developed equipment proved to be time saving and very
effective. It is simple in design and easy to make up, and it can wash whatever
glassware that is narrow in diameter and long in length.
PMID- 10684080
TI - [Changes of the gene expression of vascular endothelial growth factor in the lung
of rats with chronic hypoxic pulmonary hypertension].
AB - To observe the effect of chronic hypoxia on the gene expression of vascular
endothelial growth factor (VEGF) in rat's lung, and the role of VEGF in the
pathogenesis of hypoxic pulmonary hypertension, thirteen male Wistar rats were
exposed to isobaric hypoxia for 3 weeks. The pulmonary artery pressure was
measured by right cardiac catheterization. The serum level of VEGF was measured
by Elisa. The VEGF cRNA was labeled with digoxigenin-UTP by in vitro
transcription. The expression of VEGF mRNA in the lung was examined by
hybridization in situ. The pulmonary artery pressure was significantly increased
after hypoxic exposure. The serum level of VEGF in rats treated with hypoxia
(420.3 +/- 73.1 pg/ml) was significantly increased in comparison with that of
normal rats (322.2 +/- 58.1 pg/ml). The VEGF hybridization signals on the wall of
pulmonary arteriole were significantly increased in rats with pulmonary
hypertension. Chronic hypoxia can markedly increase expression of VEGF mRNA in
the pulmonary arteriole and hence stimulate VEGF synthesis and secretion. The
increase of VEGF may play a role in the developing process of hypoxic pulmonary
hypertension.
PMID- 10684081
TI - [Changes of level and distribution of vascular endothelial growth factor in the
lungs of rats with hypoxic pulmonary hypertension].
AB - This study was designed to elucidate whether the level and distribution of
vascular endothelial growth factor (VEGF) are changed in the lungs of rats with
hypoxic pulmonary hypertension. 13 male Wistar rats were exposed to isobaric
hypoxia for 3 weeks. The pulmonary artery pressure was measured by right cardiac
catheterization. The level of VEGF in pulmonary homogenate was measured by Elisa
method. The distribution of VEGF in the rat lung was examined by
immunohistochemistry. The results showed that the pulmonary artery pressure was
significantly increased after hypoxic exposure. The level of VEGF in pulmonary
homogenate of rats treated with hypoxia (466.9 +/- 75.5 pg/g) were significantly
increased as compared with taht of normal rats (376.2 +/- 47.1 pg/g). The
contents of VEGF in the wall of pulmonary arteriole were significantly increased
in rats with pulmonary hypertension. So we suggest that chronic hypoxia can
strongly stimulate VEGF secretion, and VEGF may mediate the process of hypoxic
pulmonary vascular remodeling and pulmonary hypertension.
PMID- 10684082
TI - [Isolation and identification of smooth muscle cells from pulmonary artery in
rats].
AB - To explore the method of isolating acutely the smooth muscle cells from pulmonary
artery in rats, small pulmonary arteries (700-200 microns, ID) were dissected
free of connective tissue and were allowed to digest in a N-2-hydroxyethyl
piperazine-N'-2-ethanesulfonic acid(HEPES)-buffered physiological saline solution
(HPSS) containing collagenase, papain and bovine serum albumin. The tissue was
then triturated to disperse smooth muscle cells. The isolated cells in suspension
were identified and photographed with film on electron microscope (EM). We
succeeded in isolating the single smooth muscle cell, which appeared compressed
typically. 90% cells in suspension were identified smooth muscle cells on EM. We
conclude that the method for isolation of pulmonary arterial smooth muscle cells
is simple, stable and effective and is recommanded for use.
PMID- 10684083
TI - [Qualitative and quantitative analyses of telomerase activity in cultured cells].
AB - In this study, we established a qualitative PCR-TRAP assay by using SYBR Green
stain instead of EB stain; this modification based on Kim's method raised the
sensitivity of telomerase detection by 25-100 fold. Besides, a quantitative assay
was established by us using 32P-ATP labeled TS primer and the internal control
TSK1. We detected the telomerase activity of 12 cultured cells by means of these
two assays. The results showed that the telomerase activity could be detected in
all the cells, but the activity levels of the cells differed prominently (from 23
to 652 TPG units). The establishment of PCR-TRAP assay and especially the
establishment of quantitative assay have enabled us to evaluate the telomerase
activity of cells more accurately, and they can be used in our further studies of
tumor gene therapy by reducing the telomerase activity of tumor cells.
PMID- 10684084
TI - [Immunoprotection in guinea pigs using DNA recombinant plasmid rpDJt and
expressed protein P68 in L. interrogans serovar lai].
AB - Immunoprotection against the infection by Leptospira interrogans serogroup
Icterohemorrhagiae serovar lai strain 017 was demonstrated in guinea pigs
vaccinated with DNA recombinant plasmid rpDJt and expressed protein P68 derived
from genomic library of Leptospira strain 017. Thirty days after active
immunization, each group received intraperitoneally (1/2 dose) and subcutaneously
(1/2 dose) inoculum of L. interrogans serovar lai stain 017; cultures were
adjusted to 5 x 10(8) cells/ml. All guinea pigs were observed for 10 days after
challenge. Survival (%) of P68 group was 100(7/7); P23 group was 75(3/4); group
rpDJt was 77(10/13); group lack recombinant (control) pT7-7 was 25 (3/12), and
group with whole-cell inactivated vaccine was 93(13/14). Although the protective
antigen in the leptospires has yet to be determined, it is evident that expressed
protein P68 conferred a high degree of immunoprotection in guinea pigs.
PMID- 10684085
TI - [A comparison study on the sensitivity of lung tumor short-term induction test in
three strains of mice].
AB - To compare the sensitivities of lung tumor short-term induction in different
strains of mice, the carcinogenicity risk was evaluated with the incidence rate
and the average number of tumors. Three different strains of mice (KM, BALB/c and
A/J) were injected with a single different dose of urethane i.p. The results
demonstrated that the lowest dose for increasing tumor risk was 100 mg/kg in KM,
200 mg/kg in BALB/c, and lower than 25 mg/kg in A/J strain. So, the sensitivity
of A/J strain is the highest and that of BALB/c is the lowest.
PMID- 10684086
TI - [Effect of fluoride on proliferation and differentiation in rat and mouse embryo
bud cell in vitro].
AB - The effect of fluoride on differentiation and proliferation of rat and mouse
embryo limb bud cell were studied with micromass cultures in vitro. Embryo limb
bud cells of rat (13-day) and mouse (12-day) were subjected to culture for 5
days. The results showed that fluoride could inhibit differentiation of cells
without affecting cells proliferation. The concentrations of 50% inhibition of
cell differentiation (ID50) were 6.8 micrograms/ml(rat) and 7.3
micrograms/ml(mouse). The concentrations of 50% inhibitions of cell proliferation
(IP50) were 44.1 micrograms/ml (rat) and 63.6 micrograms/ml (mouse). The IP/ID50
values 6.4(rat) and 8.7 (mouse) were both greater than 5. According to the
assessment criteria of Flint and Cheng Wanrong, the fluoride may be an embryo
limb bud cells specific inhibitor. It could have potent teratogenicity.
PMID- 10684087
TI - [Application of mouse limb bud culture to study the influence of zinc on
teratogenesis induced by cadmium].
AB - In this study, an in vitro method of mouse limb bud culture in self-made rotator
with continuous supplementation of gas mixture was employed in studying the
teratogenic potential of cadmium and the influence of zinc on the teratogenesis
induced by cadmium. Image analysis on the area and the form of the bone analgen
of the cultured limb was used to evaluate quantitatively their teratogenic
potentials. Different amounts of cadmium were directly added to culture medium.
As cadmium concentrations were increased from 0.1 to 1.0 microgram/ml, the degree
of morphogenetic differentiation and the area of the bone anlagen of limbs
culture were significantly decreased. The paws and long bones were affected
seriously. Cadmium had a greater effect on chondrogenic tissue than on soft
tissue. Then various levels of Zn, together with cadmium (1.0 microgram/ml
medium), were added into the culture media. As Zn concentrations increased from
1.0 to 10.0 micrograms/ml, the degree of morphogenetic differentiation and the
area of cartilaginous bone anlagen of limbs culture were improved or increased.
The long bones were better ameliorated as compared with the paw.
PMID- 10684088
TI - [The effect of electroacupuncture stimulation an neurotrophic substance in cat
spinal dorsal horn].
AB - For exploration of the mechanism of collateral sprouting from injured spinal
cord, polyacrylamide gel electrophoresis (PAGE) and modified hanging drop culture
method were used to examine the effect of acupuncture on the amount and the
biological activity of neurotrophic substance in larger than 50 kd fraction of
dorsal horn in cat subjected to partial dorsal rhizotomy. The results showed that
the amount of protein in relative mobility (RM) 0.1 zone increased significantly
in the acupuncture-operated group by PAGE and that of protein in RM 0.5 zone
decreased significantly as compared with the unoperated group. While this data
was compared with the data of another operated group in our lab, the amount of RM
0.1 protein of the acupuncture-operated group was significantly higher than that
of the latter group; however, no obvious difference was noted between the two
groups in the amount of RM 0.5 protein. It suggests that acupuncture may promote
tha amount of RM 0.1 protein to increase, but acupuncture has no influence on the
amount of RM 0.5 protein. Also, the results showed that, in culture, accompanying
with the increase in amount, the activity of RM 0.1 protein for promoting DRG
neurite-outgrowth increased. This indicates that the RM 0.1 protein has a
function to promote DRG neurite-outgrowth, but the RM 0.5 protein has no obvious
effect on DRG neurite-outgrowth.
PMID- 10684089
TI - [Detecting expression of the multidrug resistance gene product (P170) in human
tumor tissues and cells by flow cytometry].
AB - We have detected the human multidrug resistance gene (MDR1) product P170 in 29
solid tumor samples and K562 cell line through indirectimmunoflourence staining
by flow cytometry using mouse monoclonal antibody (McAb). The results showed that
the expression of P170 was detected in 18 samples, the positive ratio being
62.1%; the expression was not detected in 11 samples, the negative ratio being
37.9%; and 99.9% of K562 cells expressed P170. In 16 of the 18 positive samples,
the percent ratio of tumor cells for expression of P170 was less than 30%; in the
other 2, more than 30%. This indicated that the positive ratio of P170 of most
tumor samples was high, but their percent ratio of P170 was low. Thus it provided
a parameter for reference in evaluating the efficacy of clinical antitumor
treatments.
PMID- 10684090
TI - [Determination of valaciclovir polybutylcyanoacrylate nanoparticles].
AB - The valaciclovir content of polybutylcyanoacrylate nanoparticles was determined
by HPLC after dissolving the valaciclovir-poly butylcyanoacrylate nanoparticles
in a solvent mixture. ODS-C18 column was used. The mobile phase consisted of
CH3OH-0.02 mol/L KH2PO4 (20:80). The linear range was 2.02-20.20 micrograms/ml;
the recovery 97.30%, and RSD 4.90%. This method is accurate and can be used for
determining the contents of other nanoparticles.
PMID- 10684091
TI - [A study of immobilized enzyme-assisted semisynthesis of human insulin].
AB - In this paper, a study on preparation of human insulin by immobilized enzyme
assisted semisynthesis is reported for the first time in our country. Porcine
insulin with Thr(Bu(t)OB(t) catalyzed by immobilized trypsin has been converted
into human insulin via a two-step transpeptidation. With the systematic technique
of optimization, the rate of transpeptidation is 66%-70%. PAGE photometry is used
to determine the conversion rate of semisynthesis. PAGE and C-terminal analysis
of protein are adopted to identify the semisynthesis human insulin.
PMID- 10684092
TI - [Improving the bonding strength of castable ceramic crowns].
AB - To study the influence of bonding agent on fracture strength of Plat-II castable
ceramic crowns bonded to molars, we tested the specimens in vitro with Panavia 21
resin bonding agent and porcelite dual cure cement. The results showed that the
fracture loading (845.8 +/- 137.1 N) of crowns bonded with Panavia 21 bonding
agent was higher than that (534.0 +/- 58.7 N) of crows bonded with porcelite dual
cure cement. The difference between the two agents was statistically significant
(P < 0.05). The crowns bonded with Panavia 21 agent had higher strength than bite
forces. These suggest that costable ceramic crowns could be bonded with Panavia
21 resin agent in clinical practice.
PMID- 10684093
TI - [A biodistribution experiment on 125 I-VIP in mice].
AB - This experiment was designed to investigate the biodistribution characters of 125
I-vasoactive intestinal peptide (VIP) with high specific activity in normal mice
and the effect of VIP on the distributive test. After intravenous injection of
125 I-VIP, the mice were killed during 180 min. Blood, lungs, liver, intestine
and kidneys were collected respectively and measured in 7 counter, finally the
measurements of their radioactivity (cpm) were converted into ID%/g tissue and
the results were expressed as mean+/-s. The effect on VIP on distributive test
was evaluated by simultaneously injection of 125 I-VIP (74kBq) which contained
10,20 and 40 microgram VIP respectively; the mice were killed at 5 and 20 min.
respectively, the collection of tissues and the management of data were the same
as above. Most of the 125 I-VIP was distributed in the lungs rapidly, the
radioactivity was mainly eliminated through kindneys; the T1/2 of activity in
blood was shorter than 20 min; the difference in activity between liver and blood
was not significant after 20 min. (P >0.05); the activity intestine remained
lower during the experiment. The uptake of 125 I-VIP in lungs, liver and
intestine was inhibited by VIP in dose dependence. The rates of inhibitory
effectiveness of 10, 20 and 40 microgram VIP in lungs were 45.12%, 56.64% and
68.12% respectively at 5 min., and 53.65%, 71.03% and 79.03% respectively at 20
min. The present study indicated that the uptake of 125 I-VIP in various tissues
of the mice possesses the character mediated by VIP receptor, 125 I-VIP is mainly
accumulated by lungs, eliminated through kidneys, and the hepatobiliary system
cannot remove it. The biodistribution character of 125 I-VIP is helpful to 131I
(123I)-VIP imaging in the detection of gastrointestinal tumor.
PMID- 10684094
TI - [Effects of flunarizine and vitamin C on hemodynamics in rat heart subjected to
ischemia-reperfusion].
AB - Langendorff perfusion isolated rat heart was subjected to total global ischemia
(coronary flow rate is equal to zero) for 10 minutes and reperfusion for 15
minutes. The heart rate (HR), left ventricular developed pressure (LVDP),
coronary flow rate (CFR), electrocardiogram (ECG) and the effects of calcium
antagonist-flunarizine (FNZ) and/or oxygen free radical scavenger--vitamine C on
the above parameters were observed. The results showed that FNZ dilated coronary
vessel (P < 0.01) and had a slight negative chronotropic effect, but it had no
effect on LVP. Vitamine C did not affect HR, LVP and CFR. The recovery of the
product of HR and LVDP-Rate Pressure Product (RPP) in the FNZ + Vit. C group,
Vit. C group and FNZ group was significantly higher than that in the control
group (P < 0.05) at ten minutes reperfusion. All the results suggest that FNZ and
Vit. C may improve the recovery of heart function after reperfusion.
PMID- 10684095
TI - [Expression of glial cells line-derived neurotrophic factor in the central
nervous system of rat].
AB - Glial cell line-derived neurotrophic factor (GDNF) iss a distant member of the
transforming growth factor-beta, originally isolated by virtue of its ability to
induce dopamine uptake and cell survival in cultures of embryonic ventral
midbrain dopaminergic neurons, and more recently it has been shown to be a potent
neurotrophic factor for motor neurons. However, the distribution of this molecule
in the central nervous system (CNS) is not known yet. In the present study, the
expression of GDNF of rat was investigated by using immunohistochemistry. GDNF
immunoreactive fibers or bodies were found in molecular layer and Purkinje layer
of cerebellum. In the spinal cord, neuronal expression was found widely,
especially in ventral horn, Clarke's column. GDNF was also expressed in fiber
terminals of I and II lamella of dorsal horn. Additionally, GDNA expression was
found in the ependymal epithelium and neuroglia of spinal cord. The nuclei of
neuroglia were stronger than perikaryon. The neurons in cerebral cortex showed
very weak immunoreaction. We conclude that GDNF is expressed in many different
cellular systems within the CNS, suggesting the multiple functions of GDNF in the
adult CNS.
PMID- 10684096
TI - [Regulative effects pentagastrin and somatostatin on growth of human gastric
cancer cells in vitro].
AB - In order to observe the regulative effects of pentagastrin (PG) and somatostatin
(SS) on the growth of two human gastric cancer cell lines (HGC803 and HGC823) in
vitro, we observed the effects of PG and SS on proliferation of human gastric
cancer cells by means of MTT. The contents such as gastrin, insulin, and glucagon
were determined by radioimmunoassay (RIA), and the hexosamine content was
determined by Neuhaus' method. The results showed that the growth of the two
human gastric cancer cell lines were obviously promoted by PG. On the contrary,
the growth and secretion of gastrin and glucagon were inhibited by SS. In
addition, the hexosamine content of human gastric cancer cells was significantly
increased by PG (7.58 +/- 0.66 versus 4.20 +/- 0.39 pg/cell, (P < 0.05). But the
hexosamine content was decreased by SS (2.62 +/- 0.29 versus 4.20 +/- 0.39
pg/cell, P < 0.05). These findings indicate that the growth of gastric cancer
cells is regulated by PG and SS, nevertheless a host of problems need to be
elucidated.
PMID- 10684097
TI - [An endometrium morphometry study on ovariectomized rats subjected to nilestriol
and estradiol replalcement therapies].
AB - This study was designed to evaluate the effect of estrogen on rat endometrium and
compare the results of Nilestriol and Estradiol replacement therapies for
preventing osteoporosis in ovariectomized rats. Forty 4-month old SD female rats
were randomly divided into four groups, namely sham operation, bilateral
ovariectomy, ovariectomy plus supplementary ethinyl estradiol (0.2 microgram/100
g B. W. qd x 5), and ovariectomy plus supplementary Nilestriol (0.15 mg/100 g B.
W. once a week). Computerized image analyzer was used to evaluate the endomitrial
pathological changes 10 weeks later. The results showed an atrophied endometrium
in ovariectomized group, a slightly proliferative endometrium in Nilestriol
treated group, and a markedly proliferative endometrium with local atypical
hyperplasia in estradiol treated group. The difference between group 3 and group
4 in morphometry was significant (P < 0.5). These suggest the relative safety of
Nilestriol replacement therapy for preventing menopausal osteoporosis.
PMID- 10684098
TI - [Clinicopathological and immunohistochemical study of hepatoblastoma].
AB - To investigate the relationship between immunoreaction of histologic subtype and
prognosis, this paper analysed the clinicopathological data from 20 cases of
hepatoblastoma. Immunohistochemical staining was performed in 18 cases. The
results showed that cytopolasmic postivities of epithlial tumor cells were
observed by CK, AFP, S-100 protein and vimentin in 14, 10, 9 and 4 cases
respectively. Positive staining for CEA was seen in the nuclei of epithelial
tumor cells in 11 cases. Nuclear P53 protein staining was found in 9 cases.
Nuclear and cytoplasmic postivities of P16 protein were observed in 7 cases. S
100 protein, vimentin, CK and P16 protein were detected in mesenchymal component
in 1 case. This study suggested that immunoreactions of hepatoblastomas were
different in histologic subtypes. The expression may correlate with the
neoplastic differentiation and prognosis.
PMID- 10684099
TI - [Effect of ischemia/reperfusion in cardiac surgery with cardiopulmonary bypass on
nitric oxide levels of peripheral blood in patients].
AB - To examine the effect of ischemia/reperfusion in cardiac surgery with
cardiopulmonary bypass (CPB) on nitric oxide (NO) levels of peripheral blood,
venous levels of NO2- and NO3- were measured at multiple time-points before,
during, and after CPB by means of high-pressure liquid chromatograph to reflect
NO concentration indirectly in 20 patients. The results showed there was a linear
regression between the decreased trend of NO release at the period of peri-CPB is
related to the endothelial cell activation caused by ischemia/reperfusion at the
same time. Therefore it is necessary to explore the regulation and action of NO
release during systemic inflammatory response procedure in CPB.
PMID- 10684100
TI - [Quantitative analysis of motor unit potential in patients with dermatomyositic
disease].
AB - To diagnose dermatomyositic disease well, we adopted the method of EMG in an
investigation of 37 patients. Their electrophysiologic parameters of 220 muscles
were determined. The results showed that the parameters, including the average
DUR, AMP, RISE, AREA, AR/AM and SI of motor unit potentials (MUPs) were
significantly lower than those of the controls (P < 0.05 or P < 0.01), especially
AREA and SI (P < 0.01). But no remarkable difference was found between the
muscles on the two sides of the diseased extremties. These findings suggest that
quantitative analysis of MUPs is of importance to diagnosis of dermatomyositic
disease and the parameters such as AREA and SI may provide more valuable
information.
PMID- 10684101
TI - [A longitudinal study on growth model and velocity of term small for gestation
age].
AB - To probe into the vegetal pattern and find out the key period of promoting normal
growth of term small for gestational age (TSGA), a longitudinal study on growth
model and velocity of TSGA was conducted from Jan 1993 to June 1997. The body
weight and length of 150 children of TSGA (57 boys, 93 girls) and 152 children as
controls (58 boys, 94 girls) were measured from the 1st month to 36th month. The
growth model was analysed by multilevel models. The result showed that there was
a difference between the growth models of TSGA and controls. During 8 and a half
months (center month), the weight, length of controls were 1.19 kg, 3.46 cm
greater than those of TSGA; the weight, length of boys were 0.34 kg, 1.08 cm more
than those of girls respectively. The growth velocity of TSGA was similar to that
of controls. The maximal growth velocity was observed during the first 6 monthes
after birth. The order of growth velocity from high to low was 1 mo. > 2 mo. > 3
mo. in length and weight, showing that children of TSGA have their own growth
model. Their growth velocity should be monitored attentively. If low velocity
appears one should search for the cause and adopt apropriate measures to ensure
their growth in accordance with their "own track".
PMID- 10684102
TI - [Relationship between PGI2, TXA2 and threatened preterm].
AB - The objectives of this study were to investigate the levels of 6-keto-PGF1 alpha,
TXB2 and progesterone in plasma and cervical mucus of women with threatened
preterm labor (Group I), term labor (Group III) versus their controls (Groups II
and IV) respectively and to investigate the relationship between these substances
and threatened preterm labor. One case was matched with one control (pregnant
woman) by weeks of gestation. Radioimmunoassay was used to determine the levels
of 6-keto-PGF1 alpha, TXB2 and progesterone. Statistical differences were
assessed by student t test. The results showed that the levels of TXB2, 6-Keto
PGF1 alpha in plasm from women with term labor and threatened preterm labor were
higher than those of the control groups (P < 0.001) respectively. The ratios of 6
keto-PGF1 alpha and TXB2 were lower than their controls (P < 0.001) respectively.
No differences in the levels of progesterone were noted between the labor groups
and their control groups (P > 0.05) respectively. The results observed in
cervical mucus were in line with there in plasma. These results suggest that the
levels of PGI2, TXA2, and PGI2/TXA2 ratio were associated with the onset of term
labor.
PMID- 10684103
TI - [Effects of plasma endothelin-1 and aldosterone on sodium retention in children
with nephrotic syndrome].
AB - The effects of plasma endothelin-1 (ET-1) and aldosterone (Ald) on sodium
retention in children with nephrotic syndrome were investigated. 14 cases were
divided into the edematous stage and non-edematous stage. Plasma ET-1, Ald, and
serum osmolarity, albumin (Alb), and Na+ were measured in each stage. The results
showed that the plasma ET-1 in edemaous stage increased significantly, compared
with that in no-edematous stage (P < 0.01). There was no significant difference
in plasma Ald between the edematous stage and the non-edematous stage. Plasma ET
1 was positively correlated with the serum sodium ionic concentration and
negatively correlated with the serum Alb(r = 0.486, P < 0.01; r = 0.490, P <
0.01, respectively). In conclusion, the sodium retention with nephrotic syndrome
might be correlated with reduction of secreted sodium in the kidney, suggesting
that ET-1 plays an important role in pathogenesis.
PMID- 10684104
TI - [Observations on rat's muscle at various postmortem intervals by scanning
electron microscopy].
AB - The aim of this study was to observe the morphological changes of muscle in the
process of rigor mortis. The quadriceps of 40 rats at various postmortem
intervals were observed under the scanning electron microscope (SEM) and the
light microscope by phosphtungstic acid-haematoxylin staining. The results showed
that the striations of muscle were blurred within 4 hours, but they became
apparent from 6 hours to 24 hours after death. The authors suggest that this
phenomenon be associated with the increased resistance of muscle against the
postmortal changes. The observations by scanning electron microscopy and light
microscopy have revealed that the muscles do contract in the process of rigor
mortis because the distance between two Z lines shortens and the I band narrows,
compared with those in anaesthetised animals. The basic biochemical process for
the formation of rigor mortis is the same as that of muscle contraction except
that the former happens postmortem and the latter antemortem.
PMID- 10684105
TI - [Sjogren's syndrome and malignant lymphoma].
AB - To diagnose and study the early stage of Sjogren's syndrome associated with
malignant lymphoma, the authors used the PCR technique of B malignant lymphoma
gene for lacrimal gland tissues in four patients with Sjogren's syndrome and in
five patients suffering from B malignant lymphoma. The results showed that all
cases of Sjogren's syndrome were negative and all cases of B malignant lymphoma
were positive. These suggest that in general the patients with primary or
secondary Sjogren's syndrome have no malignant lymphoma genes, but those who have
chronic fever and enlarged superficial lymph nodes should under go this technique
for early diagnosis and treatment of Sjogren's syndrome associated with malignant
lymphoma.
PMID- 10684106
TI - [Preparation of acyclovir-polybutylcyanoacrylate-nanoparticles by emulsion
polymerization method].
AB - The aim of this study was to optimize the conditions and technology of preparing
acyclovir-polybutylcyanoacrylate-nanoparticles (ACV-PBCA-NP) which has the
diameter of about 100 nm and the shape of a sphere. The influential factors on
sphericization were observed by single factor optimization. The preparation
conditions and technology were optimized by the even design method. The contents
of acyclovirin in acyclovir polybutyloganoacrylate nanoparticles were determined
by HPLC. The optimum conditions and technology of preparing acyclovir
polybutylcyanoacrylate nanoparticles were decided and put into use. The average
diameter of the ACV-PBCA-NP thus prepared was 108.5 +/- 94.8 (n = 588). Its
embedding ratio was 71.8%, and drug loading was 18.5%. The results suggest that
the conditions and technology of preparing ACV-PBCA-NP presented in this paper
are stable and practical.
PMID- 10684107
TI - [Identification and determination of Shenbaiye].
AB - This study was amied at the method of identifying and determining Shenbaiye so
that a ground can be provided for the quality requirements. Three Chinese materia
medica (Radix Sophorae flavescentis, I; Cortex Phellodendri, II; Rhizoma
Atractylodis, III) of Shenbaiye were identified by means of TLC successfully. The
method in detail and the chromatogram were presented. The determination of I in
Shenbiaye was carried out by solid phase cleaned-up and separated through neutral
alumine column (10 x 1 cm i.d.) eluting with chloroform. This eluent was
extracted with sulphuric acid (0.01 mol/L) and the excess of acids was titrated
with sodium hydroxide (0.02 mol/L) using the methyl red as an indicator. The
total alkaloid content of I was calculated as matrine of I in Shenbaiye. This
method was established with a precision of 1.10% (n = 5) and the recoveries of
97.59 +/- 1.28% (n = 8). The results of determination of samples were reported.
PMID- 10684108
TI - [Patch clamp recording in brain slice--modified blind method and the perforated
patch clamp method].
AB - The use of the patch clamp recording in combination with the technique of the
brain slice is the forefront method widely used in the studies of the
neurocircuit in vitro. However, few authors in the papers published in domestic
journals adopted this method. This paper presents the author's work to modify
some details of blind method and the perforated patch clamp method. We used a
dissecting microscope (with 40 times object lens) to replace the reverse
microscope. As the recording electrode is very important in the experiment, we
studied the size and the shape of the electrode tip and used two to three steps
to pull the electrode so that the process of polishing of the electrode tip was
not necessary and in perforated patch recording the synaptic transmission could
be observed at the depolarization of 0-40 mV. The author also showed typical
current or voltage waveforms in voltage or current mode respectively for guiding
how to obtain the tight-seal whole cell patch. As these modifications have
facilitated the acquisition of stable recording and lowered the cost of
instrumentation, the methods become more suitable for the use in domestic
laboratories.
PMID- 10684109
TI - [CCD-diode array spectrophotometry used for simultaneous determination of cadmium
and lead].
AB - A new spectrophotometric setup for simultaneous determination of lead and cadmium
has been developed. It is composed of charge coupled device (array detector),
multichromatic instrument and computer. The optimum chromogenic conditions of
meso-tetra (4-trimethylammoniumphenyl) porphine (TAPP) with cadmium and lead were
studied and reported in this paper. The linear ranges of Pb and Cd were 0-0.50
microgram/ml and 0-0.20 microgram/ml respectively. The detection limits were
0.001 microgram/ml for both Pb and Cd. The proposed method has been successfully
applied to the simultaneous determination of cadmium and lead in the synthetic
samples and the soaking solutions of ceramics and enamel. The recoveries of
spiked samples ranged from 84.4%-118.6% and the average recovery was 100.8% with
RSD of 1.0%-9.1%. The proposed method is more sensitive, more accurate and faster
than the traditional one, it can be used to simultaneously determine multiple
elements.
PMID- 10684110
TI - [Gene expression and distribution in mouse abdominal cavity mediated by
adenovirus].
AB - Infection and expression of recombinant human adenovirus in mouse abdominal
cavity was reported. After adenovirus vector Ad/RSV-beta-gal harboring the E.
coli lacZ marker gene was injected into mice abdominal cavity, the peritoneal
surface of jejunum, ileum, colon, uterus, liver, spleen, stomach, bladder,
abdominal wall, diaphragm and testis was found large patches of lacZ-positive
cells. But the adenovirus vector was not able to penetrate the peritoneum, as
demonstrated by histochemical staining. Another adenovirus vector Ad/RSV-tk
harboring the HSV-tk gene was injected into mouse abdominal cavity and the mouse
was treated with ACV. No acute toxic reaction was observed. Based on these data,
the feasibility of gene therapy of malignant tumor within abdominal cavity with
adenovirus mediated TK/GCV system was discussed.
PMID- 10684111
TI - [Studies on cell signaling immunomodulated murine peritoneal suppressor
macrophages: LPS and PMA mediate the activation of RAF-1, MAPK p44 and MAPK p42
and p38 MAPK].
AB - Monocytes-macrophages which serve as host immune cells to kill pathogens can
often be "activated" after exposing to viruses, bacteria, cytokines as well as
chemical substances, However, it is paradoxical that highly activated macrophages
can be induced to become the suppressor ones by live microbes, microbial
products, tumor, and autoimmune disease, although the mechanism remains unknown.
Our previous experimental studies have shown that immuno-suppressor activities of
suppressor macrophages on T, B and NK cells can be prevented by the treatment
with LPS or supernatant in vitro from mitogen-stimulated lymphocytes, while, at
the same time, the tumoricidal activities of those macrophages can be kept or
even enhanced following the same treatment. This phenomenon was then termed as
"immune modulation" For the understanding of its mechanism, we are now
undertaking signal transduction in modulated macrophages. Since mitogen-activated
protein kinase (MAPK) is an integration point of different signal transduction
pathways, its cascade and regulation of activation are being investigated
extensively by the assay of electrophoresis mobility shift. Recent results
suggested that interaction of ligand-receptor triggers protein tyrosine
kinase(PTK) activation leading to Ras-GTP binding with Raf-1 to phosphorylate
MAPK kinase (MAPKK), the specific activator of MAPK. It is reported that PKC
alpha can directly phosphorylate or activate Raf-1 in NIH3 T3 cells. Raf-1 (74
KDa), with an intrinsic serine (Ser)-threonine (The) kinase activity, becomes
hyperphosphorylated after activation which can be followed by gel mobility shift
test. It has also been shown that a variety of extracellular factors stimulate a
pair of MAPK p44 and MAPK p42 of MAPK family members. A significant property of
activation of ERK 1 and ERK 2 is the requirement for the phosphorylation of both
Thr-183 and Tyr-185 (at TEY motif) within in its protein kinase subdomain VIII.
More recently, two other MAPK subtypes, p38 MAPK (mammalian equivalents of HOG1
in yeast) and JNK MAPK have been discovered. The requirement for activation of
p38 MAPK for both Thr-180 and Tyr-182 (at TGY motif) has been shown. p38 MAPK is
important in certain transcriptional regulatory pathways, since it can
phosphorylate the following transcriptional factors: 1) Elk at Ser 383/389 for
binding with SRE motif; 2). ATF 2 at Ser 69/71, forming a complex with Myc for
DNA binding at CRE motif; 3) Max at Ser-62 to combine DNA of E-Box motif. p38
MAPK can be activated by LPS, inflammatory cytokines, such as TNF and IL-1,
osmolarity. To examine the possibility that whether activation of Raf-1 and ERK
1, ERK2 and p38 MAPK can be regulated directly or/and differently by PKC and PKA
pathways, herbimycin A (Ki = 0.9 mumol/L), a potent PTK inhibitor (J. Immunol.
155:3944-4003, 1995) at 2 mumol/L concentration was utilized to block Ras/Raf
1/MAPK cascade. After pre-incubation of macrophages with herbimycin A for 30 min
or 90 min, cells were treated with LPS (10 micrograms/ml) and PMA (100 nmol/L)
for 15 min. No inhibition of phosphorylation of Raf-1, MAPK p44 and MAPK p42 in
response to LPS and PMA was observed (Fig. 1 and 3). However, forskolin, a cAMP
inducer for protein kinase A (PKA) activation, inhibited the phosphorylation of
LPS- and PMA-stimulated Raf-1, MAPK p44 and MAPK p42 (Fig. 2 and 4). Similarly,
in agreement with a very recent report from David, M et al in NIH, in which they
indicated that forskolin (30 mumol/L) inhibited IFN-beta-stimulated ERK activity
by U 266 cells (J. Biol. Chem. 271: 4585-4588 1996), we found that the levels of
phosphorylations of Raf-1 and ERK1 and ERK2 were declined when forskolin (30
mumol/L) was added to macrophages for 20 min at 37 degrees C prior to the
stimulation by LPS and PMA. Interestingly, under the same condition, forskolin
(30 mumol/L) stimulated the phosphorylation of LPS- and PMA-triggered p38 MAPK of
murine peritoneal suppressor macrophages, suggesting that activatio
PMID- 10684112
TI - [The expression of Quox-1 gene homologous sequence in the development of early
human embryos].
AB - By using the b2 fragment of Quox-1 gene as probe, we have confirmed that the Quox
1 gene homologous sequence exists in the human genome according to the results of
Southern blot. Studies on the expression of Quox-1 homologous sequence in early
human embryos from 26 to 37 days by means of immunohistochemistry technigue with
Quox-1 protein antibodies showed the spatiotemporal expression patterns: in 26
days embryo Quox-1 homologous sequence was expressed in many places including
neural tube, but 30 days later, tits expression sites were limited to notochord,
digestive epithelium, myotome, cardiac muscle cell and periderm. The functions in
control and regulation of Quox-1 gene homologous sequence during the early
development of human embryo were discussed.
PMID- 10684113
TI - [Spatial and temporally expressed proteins during Drosophila oogenesis as
revealed by monoclonal antibodies].
AB - By use of hybridoma technique, we have prepared 6 monoclonal antibodies. As shown
by antibody labeling of whole mount ovary, four of them recognized, respectively,
the antigens which were spatial-temporally expressed during oogenesis. The B 2
antigens appeared very early in the germarium and were expressed mainly by
cystocyte and nurse cells. Later, they were all transported and localized in the
posterior of oocyte, F 9 antigens followed and were also transported and
localized in the posterior of oocyte in the stage 7-8. Then, E 8 antigens
appeared and mainly localized on the membrane of oocyte in the stage 9-10. C 3
antigens were expressed much later, at about stage 14. They localized like two
caps in the perivitelline fluid at both ends of matured egg. Such specific
expression and distribution pattern of all these antigens suggest their possible
roles during oogenesis.
PMID- 10684114
TI - [Regulation of human 17 beta-hydroxysteroid dehydrogenase type 1 expression by
cyclic adenosine 3',5'-monophosphate in choriocarcinoma cells].
AB - Human 17 beta-hydroxysteroid dehydrogenase type 1 (17 HSD type 1), encoded by HSD
17 B 1 gene, is a steroidogenic enzyme catalyzing the interconversion of estrone
and estradiol. In this study, we investigated the role of cyclic adenosine 3', 5'
monophosphate (cAMP) in the regulation of 17 HSD type 1 expression in cultured
choriocarcinoma cell lines. Treatment with 8-bromo-cAMP increased 17-HSD type 1
protein concentration in JAR and JEG-3 cells, and the induction was accompanied
by parallel increase of 1.3 kb 17 HSD type 1 mRNA expression. Reporter gene
analysis revealed that the activity of HSD 17 B 1 promoter in JAR and JEG-3 cells
was induced by cAMP and that the region participating in transmission of cAMP
effect is situated in the position between -659 and -550 in HSD 17 B 1 gene. The
consequent electrophoretic mobility shift assay showed that this region formed
specific DNA-protein complexes with nuclear extracts prepared from JAR, JEG-3, T
47 D and HeLa cells. The data provide the first evidence that HSD 17 B 1 gene
transcription is activated by cAMP in choriocarcinoma cells.
PMID- 10684115
TI - [The effects of hydroxyurea on cell-cycle distribution and the expression of
human beta-globin gene in K 562 cells].
AB - Although the hydroxyurea (HU) has been extensively studied, little is known of
its molecular mechanism in controlling the expression of human globin gene and in
modulating the progression of cell-cycle in K 562 cell. In the present study, the
effect of hydroxyurea on proliferative kinetics of K 562 cells was examined by
monitoring the number of cells during a period of 8 day's cell culture. Our
results showed that there was a dose related decrease in cell growth when K562
cells were incubated with HU. Moreover, cell-cycle analysis demonstrated that HU
had profound effect on cell-cycle distribution. In the case of the induced K 562
cells, there was an increased accumulation of cells in S phase and a decreased
fraction of cells in G 1 and G 2 + M phase. Furthermore, HU could induce the
expression of human beta-globin gene in the induced K 562 cells. Our results
indicate that HU has a potential to inhibit the proliferation of K 562 cells and
to stimulate the terminal differentiation of this cell.
PMID- 10684116
TI - [Study on the transformation of mammal cells induced by glycidyl methacrylate in
vitro].
AB - Glycidyl methacrylate(GMA) can induce the phenotype transformation of human
embryonic lung fibroblasts. The transformed cells prolifeated rapidly with a
higher in the ratio of nucleus to cytoplasm, and their life span extended
notably. The transformed colonies exhibited in extensive random orientation and
the cells crossing-over. The transformed cells could be agglutinated by lower
concentration of ConA and could grow in semisolid agar. The chromosome
abberations could occur in transformed fibroblasts. These results suggest that
GMA is able to induce malignant transformation of mammal cells, and it may be
carcinogenic to human.
PMID- 10684117
TI - [Immobilization of rat liver microsomes with liquid lipid membrane
encapsulation].
AB - Rat liver microsomes were immobilized by encapsulating them into liquid lipid
membranes (56% paraffin thick, 38% paraffin thin, 5% lecthin and 1% dodecanol).
The resistance against heat and pH profile of the immobilized enzyme-NADPH
cytochrome C reductase was weakened. However, the activity and storage stability
of the immobilized enzyme were enhanced.
PMID- 10684118
TI - [Effects of propyl gallate on histopathology of liver from mice exposed to
trinitrotoluene].
AB - In addition to the hepatocellular edema and cytoplasmic eosinophilia, sludging of
blood was present in liver of mice exposed to trinitrotoluene(TNT). Single
necrosis of the partical liver cell was seen occasionally. Liver damage induced
by TNT was significantly alleviated by orally administrated propyl gallate(PG).
Futhermore, PG can promote the regeneration of the hepatocytes following TNT
exposed mice. The results suggest that PG showed a protective effect on the
histopathologic changes of liver injury induced by TNT.
PMID- 10684119
TI - [Risk of lung cancer among iron and steel workers in Anshan, China--case-control
study].
AB - A case-control interview study on 610 lung cancer patients and 959 controls was
conducted among male workers in Anshan Iron-steel Complex. After adjusting for
non-occupational risk factors, such as smoking, pulmonary disease, family history
of cancer and the consumption of fruit, risks for lung cancer were significantly
higher in workers engaged in smelting and rolling (OR = 1.5, 95% CI = 1.1-2.2),
in the fire-resistant brick factory (OR = 2.9, 95% CI = 1.4-5.9), in general
loading (OR = 2.5 95% CI = 1.0-6.1), and in coking (OR = 3.4, 95% CI = 1.4-8.5)
for 15 or more years. Significant dose-response was observed for exposure to
total dust and B[a]P, but not for specific chemical components of dust. The lung
cancer risk increased 40% in iron and steel workers with long term occupational
exposure.
PMID- 10684120
TI - [Study on the health of cotton mill workers].
AB - A group of 110 workers in a cotton mill was investigated by questionnaire, skin
testing, and the measurement of airway responsiveness through forced expiratory
volume for one second(FEV1) by spirometry. The workers were examined before
starting work, 10 weeks and one year after exposure. Decreases in FEV1 over
shifts were small at 10 weeks and one year, and were slightly higher among people
with positive skin reactions to cotton dust extracts. Airway responsiveness,
defined as the average decrease in FEV1 after 1.25 mg methacholin, was increased
at 10 weeks. It remained about the same after one year, except in the workers
with positive skin test. Subjective symptoms of chest tightness and cough with
phlegm increased progressively at 10 weeks and one year. Nasal irritation
remained unchanged and dry cough decreased in one year. The results suggest that
the airway inflammation caused by cotton dust increases with the exposure time
and that the changes are more notable in workers with reactivity to cotton dust
extract.
PMID- 10684122
TI - [Effect of particles size calibration on air microbe sampling].
AB - The airborne bacterial particles number sampled with 6 grades Andersen sampler at
Xidan in Beijing from 1987 to 1988 was calibrated by the alive bioparticles
calibration formula. The results showed that the average number of airborne
bacterial particles sampled in 3 minutes and in 84.9 L air was 257, but it is 315
when calibrated. The later was higher than the former (t = 2.012, P < 0.05). The
average number sampled with the 1st grade sampler (> 8.2 microns) was 98, but it
is 136 when calibrated, and the difference was obviously (t = 2.409, P < 0.05).
There was no obvious difference between the number sampled with the rest grades
sampler (2nd-6th) and when calibrated (t = 1.701-0.026, P > 0.05). The effects of
calibration on the particles size distribution and its concentration day's change
were not obviously.
PMID- 10684121
TI - [Influence of arsenic on proliferation and differentiation of rat bud cells in
vitro].
AB - The objective of this study was designed to evaluate the developmental toxicity
of arsenic and its effect on embryonic chondrogenesis of Sprague-Dawley rat by
using Flint's rat limb bud cell micromass cultrure system in vitro. The results
revealed that arsenic inhibited markedly both proliferation and differentiation
of rat limb bud cells in vitro and there was an obvious dose-response
relationship. The concentrations of arsenic for IP50(dose of inhibiting
proliferation by 50% of the control value) and ID50(dose of inhibiting
differentiation by 50% of the control value) were 0.70 mg/L and 0.21 mg/L
respectively. The ratio between IP50 and ID50 was 3.3. These parameters indicated
that the influence of arsenic on differentiation of rat limb bud cells was
stronger than on proliferation, and arsenic belonged to a strong teratogenic
agent and a specific inhibitor. This study suggested that the specific inhibitory
action of arsenic on limb bud cell differentiation did not result from the
cytotoxicity, but would result from the teratogenic effects of arsenic.
PMID- 10684123
TI - [Development of emission models for volatile organic compounds from indoor
materials].
AB - Volatile organic compounds (VOCs) emitted from indoor materials was a major cause
of indoor air pollution. The characteristics of VOCs emission was an important
part of research programs on indoor air quality. The technology of test chambers
with exactly controllable conditions has been successfully used in studies of
VOCs emissions. The technology could be used to model the chamber VOCs
concentration level vs time profile C(t), which could in turn be used to estimate
the sample emission rate vs time profile R(t). The emission models of VOCs from
indoor materials were presented in this review. The principal of emission
process, parameters and the applications of emission models were introduced. The
application of diffusion model, dilution model and vapor pressure (VP) model were
limited due to the existence of sink effect. Sink model is the most promising
model at present.
PMID- 10684124
TI - [Study on the preventive effect of tea on DNA damage of the buccal mucosa cells
in oral leukoplakias induce by cigarette smoking].
AB - In order to study the preventive effect of tea on DNA damage induced by cigarette
smoking and to provide further evidence on the protective effects of tea in human
cancer, a 6-month, double-blind and randomized placebo-controlled intervention
trial was carried out. The effect of tea on micronuclei frequency in exfoliated
oral buccal mucosa cells in 36 oral leukoplakias of smokers was investigated. A
kind of mixed tea given in an oral dose of 3 g/day and a concentration of 0.1%
smeared on mucosa lession three times a day for 3 months and 6 months,
significantly decreased the micronuclei formation in exfoliated oral buccal
mucosa cells in subjects with oral leukoplakias. In contrast, there was no change
in the micronuclei frequency after 6 months in the placebo group. The results
indicate that mixed tea may reduce the oral cancer risk by preventing DNA damage
in oral leukopiakias induced by cigarette smoking.
PMID- 10684125
TI - [Study on the relative absorption of food carbohydrate in healthy adults].
AB - The absorption of food carbohydrate was determined with breath hydrogen test
(BHT) in healthy adults. When the absorption of lactulose was assumed as 0, the
absorption of food carbohydrates were as follows: 100% for rice with ground lean
pork; 98% for rice; 85% for bread; 58% for corn and 30% for red potato. The
absorption of food carbohydrate was positively related to the oral-colon transit
time (OCTT, r = 0.8790) and the peak hydrogen time (PHT, r = 0.6745), and was
negatively related to the peak hydrogen value (PHV, r = -0.6468) and to the
hydrogen producing percentage (H2 > 1.8 mg/m3, r = -0.8679). The breath hydrogen
test can be used in estimating the absorption of food carbohydrate in human body
because this method is safe, non-invasive, reproducible and accurate.
PMID- 10684126
TI - [Effects of high dietary zinc on liver function, hepatic drug metabolism enzymes
and membrane fluidity in mice].
AB - Mice were fed with high zinc diet (15 g/kg) for 3 weeks. High zinc could cause
liver toxicity: 1. inhibiting the activity of GOT and GPT in liver homogenate,
reducing GSH and glycogen contents. 2. increasing the activity of aniline
hydroxylase and inhibiting the activities of NADPH-cytochrome C reducease, benzo
phytamine-N-demethylase and glutathione S-transferase. The activities of
cytochrome P450 and cytochrome b5 were not obviously changed 3. increasing
microsomal membrane fluidity in the superficial layers, but not in the deep
layers.
PMID- 10684127
TI - [Protection of vitamin E against testis lipid peroxidation induced by iron and
ethanol].
AB - The influence of acute iron and ethanol load on lipid peroxidation and
antioxidative defense systems in rat testes and the modification after
supplemented with Vitamin E was investigated. Acute iron and ethanol load was
achieved by i.p. injection of iron-dextran (500 mg/kg) and ethanol (50 mmol/kg).
After 18 h, a significant increase in testis total iron content was induced.
Compared with control, total testis iron content was 6.8-fold higher in iron
treated rats and 9.1-fold in iron and ethanol treated rats. As the content of
iron increasing, the endogenous lipid peroxidation evaluated as 2-thiobarbituric
acid-rective substances (TBARS) increased apparently, and the content of lipid
soluble antioxidants alpha-tocopherol decreased. The supplement of an
antioxidant, alpha-tocopherol, protected against lipid peroxidation. Iron and
ethanol treatment did not affect the activity of superoxide dismutase, catalase
and glutathione peroxidase. The results indicate that acute iron load causes iron
accumulation in rat testes and ethanol increases the same accumulation. Iron
played pivotal paracrine roles on ethanolinduced injure rat testis. The
supplement of Vitamin E can protect against this damage.
PMID- 10684128
TI - [Study on the human dietary intake of minerals, energy, fiber and phytic acid].
AB - Duplicate diets of three days were collected. The diets represented general
living standard of male adults. There were three types of subjects: city
inhabitants in group 1, northern peasants in group 2, and southern peasants in
group 3. The diets were analyzed to calculate the average per capita intake of
various minerals, energy, fiber and phytic acid. The assessment of intake
according to the values of RDA, ESADDI and ADI shows the following results: Zn is
low, Ca comes up to 2/3 of RDA, P reaches 88%-133% of RDA, Fe appears enough to
attain the standard, but the availability should be considered. The contents of
Se and I in each group was varied. Even though the intake of Se is low, it
reaches the minimum requirement. Since I is being supplemented for all the
people, it would not be deficient. The intake levels of Cu, Mo and Cr achieve or
surpass the minimum values of ESADDI. Mn intake exceeds the maximum value of
ESADDI, but the highest intake was only 10. 5 mg, which is far from poisoning
level. High Na and low K intakes are specific defects of Chinese diets. The level
of Cd, Hg and Pb is far apart from toxicosis. As for the amount of As intake,
only in group 3 is higher than ADI by 29%. The energy is full. Dietary fiber is
suitable. The intake of phytic acid of northern peasants is higher than that of
southern peasants and city inhabitants, but it would be harmless.
PMID- 10684129
TI - [Determination of taurine in food by high performance liquid chromatography].
AB - Taurine in food was separated by HPLC as its phthalaldehyde-ethanethiol
derivative on mu-Bondapak C18 reverse column and measured at 330 nm. The
determination was not interfered by sulphosalicylic acid, excess dervatizing
reagents and 20 kinds of amino acids. The stability of the taurine dervatives was
discussed in this paper. The result showed that the higher concentration of
borate buffer, the more stable of taurine derivatives and the lower concentration
of taurine, the faster decomposition of taurine dervitives. Using more
concentrated borate buffer (0.4 mol/L) and controlling the time between injection
and reaction and keeping the operation identically could avoid the effect of
nonstable taurine derivatives in the determination. The minimum detectable
quantlity was 8 ng. The coefficient of variation was less than 8%. The recoveries
were 90.7%-105.1%.
PMID- 10684130
TI - [Simultaneous extraction of tea-polyphenols and caffeine from green tea].
AB - Tea-polyphenols and caffeine were extracted simultaneously from green tea. The
factors influencing on the process of impregnation and extraction were studied.
The result indicated that the content of tea-polyphenols and caffeine in tea was
increased with the duration of extraction and decreased with the frequency of
extraction. The authors discuss the effect of pH on the precipition of calcium
tea-polyphenols.
PMID- 10684131
TI - [Simultaneous determination of lead and copper in food by differential potential
stripping with the presence of emulgent OP].
AB - The effect of different surfactants on the stripping analysis of Pb and Cu was
studied. The optimum condition for simultaneous determination of Pb and Cu in
foods by the differentital potential stripping analysis in the 0.3 mol/L HCl
media and by using emulgent OP as spike agent was described. The contents of Pb
and Cu in soft drinks, fermented wine and flavourings with added standards were
determined directly by synchronous mercury plating. The recovery of the added
standard samples were 95%-105%, and relative standard deviation was 0.8%-7.9%.
The proposed method has been applied to the sample analysis.
PMID- 10684132
TI - [Study on the antagonistic action of selenite on fluoride-induced lipid
peroxidation and on the changes of trace elements in rats].
AB - Five groups of SD male rats were provided with deionized drinking water
containing 0 and 150 mg/L NaF, and containing both 150 mg/L NaF and 0.5, 2.0 or
4.0 mg/L Na2SeO3 respectively for 10 weeks, in order to find out the optimal
level of selenite in drinking water against fluoride toxicity. The results showed
that fluoride could cause significant increase of lipid peroxides (LPO) and
metabolic disorder of trace elements in the serum and kidney of rats. The
antagonistic effect of 2.0 mg/L Na2SeO3 drinking water on the lipid peroxidation
induced by 150 mg/LNaF was the most evident, whereas those of 0.5 and 4.0 mg/L
Na2SeO3 were not obvious. It is concluded that selenite possesses significant
antagonistic effects on renal damages induced by fluoride and 2.0 mg/L Na2SeO3 is
the optimal concentration for the antagonistic effect on renal impairments
induced by 150 mg/L NaF in drinking water.
PMID- 10684133
TI - [Study on the joint action of selenium and cadmium on DNA damage of rat liver
cells].
AB - The effect of joint action of selenium and cadmium on DNA damage in rat liver
cells was investigated with single cell gel electrophoresis. The results show
that both selenium and cadmium can induce DNA damage at the concentration of 8.75
mumol/L, 17.5 mumol/L and 35 mumol/L. The degree of DNA damage induced by cadmium
is more serious than by selenium. When selenium and cadmium act jointly, they can
antagonize each other on DNA damage at the concentration of 8.75 mumol/L and 17.5
mumol/L, but not at the concentration of 35 mumol/L. There is an antagonism
between selenium and cadmium on DNA damage in rat liver cells at certain
concentrations.
PMID- 10684134
TI - [Effect of dietary selenium on the activities of glutathione peroxidase and
deiodinase in rat liver].
AB - In order to investigate the effect of dietary selenium on the activities of
glutathione peroxidase and deiodinase and the least selenium requirement for
their optimal activities, fifty four male weanling Wistar rats of 50-60g body
weight were randomly divided into 9 groups and were fed with semisynthetic diets
of different selenium level for 20 weeks. The selenium in the diets were 0.01,
0.02, 0.03, 0.04, 0.05, 0.06, 0.1, 0.2 and 5 mg/kg diet respectively. The body
weight of ratsin the ninth group was different significantly from the seventh and
eighth group, but those in the other eight groups were not significantly
different. The activities of liver glutathione peroxidase in 0.1, 0.2 and 5 mg/kg
groups were the highest among the nine groups. So at least 0.1 mg/kg diet is
required for its normal activity. The activities of the liver type I deiodinase
of nine groups were high from 0.05 to 0.2 mg/kg diet groups and at least Se 0.05
mg/kg diet is required for its normal activity.
PMID- 10684135
TI - [Calculating method for the necessary lamps and sterile rate in a tube-shaped
ultraviolet air washer].
AB - It has much more advantage to use the cylindric ultraviolet air washer than to
use the ordinary ultraviolet lamps. There was a calculation method for
determining necessary lamps in a rectangled ultraviolet air washer, but it had a
limiting condition. This paper developed two calculating methods for determining
necessary lamps and its sterile rate in a tube-shaped ultraviolet air washer. The
sterile rate can be extracted with any parameter. Necessary lamps can also be
extracted with its sterile rate.
PMID- 10684136
TI - 28th Annual International Neuropsychological Society Conference. Denver,
Colorado, USA. February 9-12, 2000. Abstracts.
PMID- 10684137
TI - Assessment of functional capacity through oxygen consumption in patients with
asymptomatic probable heart disease.
AB - PURPOSE: To compare peak exercise oxygen consumption (VO2peak) of healthy
individuals with asymptomatic individuals with probable heart disease. METHODS:
Ninety-eight men were evaluated. They were divided into two groups: 1) 39 healthy
individuals (group N) with an age range of 50 +/- 4.6 years; and 2) 59
asymptomatic individuals with signs of atherosclerotic and/or hypertensive heart
disease (group C) with an age range of 51.9 +/- 10.4 years. In regard to age,
height, body surface area, percentage of fat, lean body mass, and daily physical
activity, both groups were statistically similar. Environmental conditions during
the ergometric test were also controlled. RESULTS: Maximal aerobic power (watts),
VO2peak, maximal heart rate, and maximal pulmonary ventilation were lower in
group C (p < 0.01) than in group N; weight, however, was lower in group N (p =
0.031) than in group C. Differences in the respiratory gas exchange index, heart
rate at rest, and the maximal double product of the two groups were not
statistically significant. CONCLUSION: Signs of probable heart disease, even
though asymptomatic, may reduce the functional capacity, perhaps due to the lower
maximal cardiac output and/or muscle metabolic changes.
PMID- 10684138
TI - Coronary artery disease, microalbuminuria and lipid profile in patients with non
insulin dependent diabetes mellitus.
AB - PURPOSE: To determine the frequency of coronary artery disease, microalbuminuria
and the relation to lipid profile disorders, blood pressure and clinical and
metabolic features. METHODS: Fifty-five type 2 diabetic patients (32 females, 23
males), aged 59.9 +/- 9 years and with known diabetes duration of 11 +/- 7.3
years were studied. Coronary artery disease (CAD) was defined as a positive
history of myocardial infarction, typical angina, myocardial revascularization or
a positive stress testing. Microalbuminuria was defined when two out of three
overnight urine samples had a urinary albumin excretion ranging 20-200
micrograms/min. RESULTS: CAD was present in 24 patients (43.6%). High blood
pressure (HBP) present in 32 patients (58.2%) and was more frequent in CAD group
(p = 0.05) HBP. Increased the risk of CAD 3.7 times (CI[1.14-12]).
Microalbuminuria was present in 25 patients (45.5%) and tended to associate with
higher systolic blood pressure (SBP) (p = 0.06), presence of hypertension (p =
0.06) and known diabetes duration (p = 0.08). In the stepwise multiple logistic
regression the systolic blood pressure was the only variable that influenced UAE
(r = 0.39, r2 = 0.14, p = 0.01). The hypertensive patients had higher cholesterol
levels (p = 0.04). CONCLUSION: In our sample the frequency of microalbuminuria,
hypertension, hypercholesterolemia and CHD was high. Since diabetes is an
independent risk factor for cardiovascular disease, the association of others
risk factors suggest the need for an intensive therapeutic intervention in
primary and in secundary prevention.
PMID- 10684139
TI - Safety and efficacy of coronary stent implantation. Acute and six month outcomes
of 1,126 consecutive patients treated in 1996 and 1997.
AB - PURPOSE: The authors analyzed the 30-day and 6-month outcomes of 1,126
consecutive patients who underwent coronary stent implantation in 1996 and 1997.
METHODS: The 30-day results and 6-month angiographic follow-up were analyzed in
patients treated with coronary stents in 1996 and 1997. All patients underwent
coronary stenting with high-pressure implantation (> 12 atm) and antiplatelet
drug regimen (aspirin plus ticlopidine). RESULTS: During the study period, 1,390
coronary stents were implanted in 1,200 vessels of 1,126 patients; 477 patients
were treated in the year 1996 and 649 in 1997. The number of percutaneous
procedures performed using stents increased significantly in 1997 compared to
1996 (64% vs 48%, p = 0.0001). The 30-day results were similar in both years: the
success and stent thrombosis rates were equal (97% and 0.8%, respectively). The
occurrence of new Q wave MI (1.3% vs 1.1%, 1996 vs 1997, p = NS), emergency
coronary bypass surgery (1% vs 0.6%, 1996 vs 1997, p = NS) and 30-day death rates
(0.2% vs 0.5%, 1996 vs 1997, p = NS) were similar. The 6-month restenosis rate
was 25% in 1996 and 27% in 1997 (p = NS); the target vessel revascularization
rate was 15% in 1996 and 16% in 1997 (p = NS). CONCLUSIONS: Intracoronary
stenting showed a high success rate and a low incidence of 30-day occurrence of
new major coronary events in both periods, despite the greater angiographic
complexity of the patients treated with in 1997. These adverse variables did not
have a negative influence at the 6-month clinical and angiographic follow-up,
with similar rates of restenosis and ischemia-driven target lesion
revascularization rates.
PMID- 10684140
TI - Influence of the elevation of the left ventricular diastolic pressure on the
values of the first temporal derivative of the ventricular pressure (dP/dt).
AB - PURPOSE: To assess the effects of the elevation of the left-ventricular end
diastolic pressure (LVEDP) on the value of the 1st temporal derivative of the
ventricular pressure (dP/dt). METHODS: Nineteen anesthetized dogs were studied.
The dogs were mechanically ventilated and underwent thoracotomy with
parasympathetic nervous system block. The LVEDP was controlled with the use of a
perfusion circuit connected to the left atrium and adjusted to the height of a
reservoir. The elevation of the LVEDP was achieved by a sudden increase in the
height of a reservoir filled with blood. Continuous recordings of the
electrocardiogram, the aortic and ventricular pressures and the dP/dt were
performed. RESULTS: Elevation of the LVEDP did not result in any variation of the
heart rate (167 +/- 16.0 bpm, before the procedure; 167 +/- 15.5 bpm, after the
procedure). All the other variables assessed, including systolic blood pressure
(128 +/- 18.3 mmHg and 150 +/- 21.5 mmHg), diastolic blood pressure (98 +/- 16.9
mmHg and 115 +/- 19.8 mmHg), LVEDP (5.5 +/- 2.49 and 9.3 +/- 3.60 mmHg), and
dP/dt (4,855 +/- 1,082 mmHg/s and 5,149 +/- 1,242 mmHg/s) showed significant
increases following the expansion of the ventricular cavity. Although the
elevation of the dP/dt was statistically significant, 6 dogs curiously showed a
decrease in the values of dP/dt. CONCLUSION: Sudden elevation of the LVEDP
resulted in increased values of dP/dt; however, in some dogs, this response was
not uniform.
PMID- 10684141
TI - Natural course of subsequent pregnancy after peripartum cardiomyopathy.
AB - OBJECTIVE: To assess the effect of subsequent pregnancy after peripartum
cardiomyopathy (PPCM) on maternal and fetal outcome. METHODS: Prospective study
of 34 patients with the diagnosis of PPCM (mean age = 26 years). At the time of
first diagnosis 5 were in NYHA functional class (FC) II for heart failure, one in
FC III and 28 in FC IV. After clinical treatment, patients were advised to avoid
new pregnancies and a follow-up was obtained. RESULTS: There were 12 (35.3%)
subsequent pregnancies in patients (pt) aged 19 to 44 years (mean 32), divided
into two groups: GI: 6 pts who had normalized their heart size and GII: 6 pts
with persistent cardiomegaly. GI had initially mild clinical manifestations (3
were in FC II, 1 in FC II and 2 in FC IV) and complete recovery of cardiac
function (FC I). A new pregnancy was well-tolerated in 5 (83.3%); 1 pt presented
with preeclampsia, and progressed to FC II. Presently, 5 pt are in FC I and 1 in
FC II. GII pts had more severe heart failure at the onset of PPCM (1 pt in FC II
and 5 in FC IV); during follow-up, 4 pt were in FC I and 2 in FC II. A new
pregnancy was well tolerated in all of them, but the eldest, who had had 2
pregnancies and had a progressive worsening of clinical status, dying 8 years
after the last pregnancy and 13 years after the diagnosis of PPCM. The remaining
5 pt are still alive, 3 in FC I and 2 in FC II, with worsening of FC in 1.
Subsequent pregnancies occurred 3-7 years after clinical treatment of PPCM and no
fetal distress was observed. CONCLUSION: Subsequent pregnancies are well
tolerated after PPCM, but not devoid of risk. No fetal distress was observed. A
minimum interval of 3 years after the recovery of function seems to be safe for
subsequent pregnancies.
PMID- 10684142
TI - Aortopulmonary window. Clinical and surgical assessment of 18 cases.
AB - OBJECTIVE: Aortopulmonary window (APW) is an uncommon congenital malformation.
Its clinical presentation is dependent on the size of the defect and on the
associated lesions. We evaluated our experience with this anomaly and compared it
with 296 cases reported in the literature. METHODS: Retrospective study of 18
patients diagnosed as having APW (age range from 13 days to 31 years, 13 (72.2%)
females), divided into two groups: Group A (GA): 10 patients with isolated APW,
and Group B (GB): 8 patients with associated lesions. RESULTS: Heart failure
occurred in 14 patients, and cyanosis in 3:2 from GB (tetralogy of Fallot--TF,
and double outlet right ventricle--DORV), and one from GA with pulmonary
hypertension. In 5 patients from GA the diagnosis of mitral regurgitation was
made based on a systolic murmur and LV hypertrophy on the EKG. In GB, clinical
findings were determined by the associated defect. Diagnosis was established by
echocardiography in 11 (61.2%) of the patients. In 3 patients, a wrong diagnosis
of mitral regurgitation was made, in 1 a patent ductus arteriosus was diagnosed
and in 3 others, the diagnosis of APW was masked by other important associated
defects (2 cases of DORV and 1 case of TF). The diagnosis was made by
catheterization in 3 (16.6%) patients, by surgery in 3 (16.6%) and by necropsy in
1 (5.5%). Corrective surgery was performed in 14 (77.7%) patients, with one
immediate death and good long-term follow-up in the remaining patients.
CONCLUSION: APW can be confused with other defects. Clinical findings, associated
with an adequate echocardiogram can provide the information for the correct
diagnosis.
PMID- 10684143
TI - Aortic valve assessment. Anatomical study of 100 healthy human hearts.
AB - PURPOSE: To assess anatomical characteristics of the aortic valve, so that they
may be useful in diagnostic situations and surgical treatment. METHODS: The study
analyzed 100 healthy fixed human hearts; 84% of them obtained from males, 61% of
them from Caucasian individuals. The ages of the individuals ranged from 9 to 86
years (mean 30 +/- 15.5 years). The characteristics assessed related to age, sex,
and race were the following: number and height of the cusps, size of the lunulae,
internal and external intercommissural distance, position of the coronary ostium
in relation to the aortic valve, position of the ventricular septum in relation
to the aortic valve, thickness of the cusps. RESULTS: All hearts assessed had a
tricuspidal aortic valve. In regard to the height of the cusps and size of the
lunula, the left coronary cusp was larger, followed by the right coronary cusp
and the noncoronary cusp. The internal and external intercommissural distances
had mean values of 24.6 +/- 5.7 mm and 19.7 +/- 7 mm, respectively. In regard to
the position of the coronary ostia, in one heart two ostia emerged from the left
coronary sinus, and in another, the ostium was supracommissural. The mean
diameter of the aorta was 21.8 +/- 3.6 mm, and there were no significant sexual
or racial differences, but the diameter increased progressively with the increase
in age. The thickness of the cusps did not show any significant difference in the
3 points assessed. CONCLUSION: The aortic valve annulus did not show a perfect
circumference, with some variations in the measurements of the annulus, in the
cusps and in the relation with the ventricular septum.
PMID- 10684144
TI - Myocardial repair with long-term and low-dose administration of a nitric oxide
synthesis inhibitor. Myofibroblasts, type III collagen and fibronectin.
AB - OBJECTIVE: To study the healing process of the myocardium in hypertensive rats
undergoing inhibition of nitric oxide synthesis. METHODS: Two groups of animals
were studied: one received L-NAME, 12 mg/kg/day, and the other was a control
group. The presence of type III collagen, fibronectin, and alpha-smooth muscle
actin-positive cells was assessed by immunohistochemistry. RESULTS: Fibronectin
was seen in both early and late lesions, while type III collagen was seen mainly
in areas of incomplete healing, situated among myocytes and around the
intramyocardial branches of the coronary arteries. Areas representing early and
late lesions showed a population of spindle-shaped cells. Immunohistochemistry
showed that these cells were positive for alpha-smooth muscle actin. CONCLUSION:
In the myocardium of hypertensive rats, the alpha-smooth muscle actin-positive
cells are related to the accumulation of type III collagen and fibronectin in the
areas of myocardial damage.
PMID- 10684145
TI - Essential thrombocythemia and acute myocardial infarction treated with rescue
coronary angioplasty.
AB - A 48-year-old man with essential thrombocythemia suffered an extensive anterior
acute myocardial infarction; this is a rare association. A pharmacological
thrombolysis was performed, without success. He subsequently underwent successful
rescue coronary angioplasty. To our knowledge, there is no other report in the
literature relating the triad of essential thrombocythemia, acute myocardial
infarction and rescue coronary angioplasty.
PMID- 10684146
TI - Left ventricular hypertrophy in systemic hypertension. Benefits of its reversal.
PMID- 10684147
TI - Physical activity at moderate and high altitudes. Cardiovascular and respiratory
morbidity.
PMID- 10684148
TI - [Banco Mundial/FNUAP/OMS/PNUD. Special program of investigation, development and
formation of investigators on human reproduction. Guidelines for the creation of
scientific and ethical revision agencies].
PMID- 10684149
TI - [Ethical conflicts in the exercise of the role of health agents].
PMID- 10684150
TI - [Lanari Lecture. Hematopoietic cytokines and hematologic disorders].
PMID- 10684151
TI - Current trends in antiretroviral therapy for HIV infection and AIDS.
PMID- 10684152
TI - [Studies of drug utilization: a necessary instrument to promote the rational use
of drugs].
PMID- 10684153
TI - The steroidogenic acute regulatory (StAR) protein.
PMID- 10684154
TI - Steroidogenic factor 1: a key mediator of endocrine development and function.
PMID- 10684155
TI - Sources and function of neuronal signalling molecules in the gonads.
AB - While the hypothalamic-pituitary-gonadal axis is crucial for the function of the
gonads, non-endocrine regulatory influences are exerted by other factors within
the gonads. Among these factors are neurotransmitters, such as catecholamines.
Several types of receptors for catecholamines exist in the gonads on vascular or
endocrine cells. Their activation can alter blood flow, steroidogenesis and gene
expression, depending on the target cells. Recently a neuronal-like cell type
expressing catecholamine-biosynthetic enzymes and neuronal proteins was
identified in testis and ovary of human and non-human primates. Together with the
well-known sympathetic innervation, this gonadal nervous system may serve as a
source of catecholamines. Dopamine is present in the follicular fluid. Oocytes,
while not able to perform de novo synthesis of catecholamines, were shown to
utilize dopamine to produce norepinephrine. This catecholamine then acts on beta
adrenoreceptors of follicular cells to increase cAMP. Oocytes may thus indirectly
via dopamine and cAMP be able to control their own meiotic arrest. In addition,
neurotransmitters may also be synthesized in other, non-neuronal ovarian cells.
Thus, cultured human granulosa-luteal cells possess the acetylcholine
synthesizing enzyme and the acetylcholine-specific vesicular transporter protein.
These cells also express muscarinic-receptors (M1), which are linked to the
mobilization of intracellular calcium and cell proliferation. This suggests
involvement of the acetylcholine system in follicular growth and in the
periovulatory events. In neurons, neurotransmitters alter the properties of the
neuronal cell membrane. If this is the case in endocrine cells of the gonads is
not yet clear, but the recent identification of voltage-activated potassium and
sodium channels in human luteinized granulosa-luteal cells raises this question
and opens a door to a new area of investigation.
PMID- 10684156
TI - Glypican-3 is a novel inhibitor of insulin-like growth factor signaling.
PMID- 10684157
TI - The role of plasminogen activator receptor in cancer invasion and dormancy.
AB - Urokinase plasminogen activator receptor (uPAR) has been identified some 15 years
ago and the anticipation was that its presence on the cell surface will provide a
focus for anchoring uPA and possibly protect the enzyme from native inhibitors.
The studies of the last decade have shown that uPA localized to the surface of
cells by uPAR is indeed an important factor in the process of cancer cell
invasion and metastasis. We developed a chick embryo model in which we showed
that uPAR is crucial in invasion of stroma and in intravasation (breaching of the
blood vessels walls). More recently and unexpectedly, uPAR--a protein anchored in
the outer leaf-let of the plasma membrane, has been shown to initiate signal
transduction events and affect cell migration. We have shown that uPAR co
associates with fibronectin binding integrin, alpha 5 beta 1, activates them and
that this interaction leads to a greatly increased level of active ERK. When the
association between uPAR and integrin or integrin and fibronectin are interrupted
either by reduction of surface uPAR expression, or by other means, human
carcinoma cells enter a state of protracted dormancy. We show that very high
levels of active ERK are required to keep cancer cells proliferating in vivo.
PMID- 10684158
TI - Suppression of tumor cell growth by type IV collagen and a peptide from the NC1
domain of the alpha 3(IV) chain.
PMID- 10684159
TI - [Metabolic changes in 2612 patients with nephrolithiasis].
AB - Nephrolithiasis is one of the most frequent pathologies of the urinary tract. Its
prevalence in the city of Buenos Aires is 4%. Different biochemical and
physiological disturbances may create an environment conductive to renal stone
formation. We present the results of an ambulatory evaluation in 2612 patients
for the purpose of updating the classification of nephrolithiasis. An abnormal
urinary biochemistry was observed in 2423 patients (92.8%) that could be
classified in 15 categories. A single diagnosis was documented in 61.5% of the
patients, and the remaining 31.2% had more than one diagnosis (concurrent
abnormalities). No abnormality was found in 189 stone formers (7.2%). Idiopathic
hypercalciuria was the most frequent abnormality, it was encountered in 31.2%;
hyperuricosuria and gouty diathesis (presence of urine pH < 5.5, with normal or
high uricemia) accounted for 9.4% and 5.4% of patients, respectively. On the
other hand, hypomagnesuria affected 6.7% of the stone formers and hypocitraturia
was observed in 4.5%. Primary hyperparathiriodism, hyperoxaluria and cystinuria
were seen less frequently in 2.6%, 1.3 and 0.45% of patients. Low urine volume
was found in 12% of the patients. Among those patients with more than one
abnormality, we found that hypercalciuria together with hyperuricosuria and
hypocitraturia (12%) was the prevalent association followed by hypercalciuria
with hyperuricosuria (9.1%). Our results show the importance of studying
nephrolithiasis patients from a biochemical point of view, since this is the only
way to achieve a diagnosis of the metabolic abnormality and introduce a specific
therapy to prevent recurrence.
PMID- 10684160
TI - [Atrioventricular node catheter ablation with condenser discharge and
radiofrequency].
AB - The AV junction ablation was useful to treat patients with drug-refractory
supraventricular arrhythmias. The purpose of this study was to determine short
and long-term success and complications of the atrioventricular nodal catheter
ablation and to compare direct current and radiofrequency energy. Forty patients
underwent AV nodal ablation with direct current energy (Group I) and forty
patients with radiofrequency (Group II). They were followed up for a mean of 76
+/- 49 and 28 +/- 20 months, respectively. Persistent complete AV block was
successfully induced during the first ablation session in 45% of 40 patients who
underwent DC energy, while in 50% it was modulated. All patients in the
radiofrequency group had complete AV block. The rate of recurrence of AV
conduction was 7.5% and 2.5% respectively. Immediate complications did not occur
after either procedure. One patient died suddenly in each group during follow-up.
AV nodal ablation with radiofrequency energy appears to be as efficacious and
safe as direct current energy.
PMID- 10684161
TI - [Effect of iron supplementation and its frequency during pregnancy].
AB - The iron (Fe) nutritional status of 203 healthy pregnant women was assessed at
the first prenatal visit (To) (gestational age: 16.9 weeks +/- 3.81. Women were
randomly assigned to one of three groups: G1 and G2 were supplemented with
ferrous fumarate (60 mg elemental Fe) daily or intermittently (three times a
week), respectively; and GC was the control group, without supplementation. The
follow up was carried out until 34-37 weeks of gestational age (Tf), but only 43%
of pregnant women completed the trial. At To and Tf fasting blood samples were
collected and Hematocrit (Hct), Hemoglobin (Hb), Erythrocyte Protoporphyrin (EP)
and Serum Ferritin (FERR) were determined. The percentage of women with abnormal
biochemical values at To (n = 203) was: Hb (g/dl) < 10.5: 2.6%; PE (microgram/dl
of red blood cells) > 70: 4.8%; FERR (ng/ml) < 10: 4.4%. Results (X +/- DE) of
women that completed the follow up were at To and Tf, respectively: Hct (%): GC:
37.7 +/- 3.4 and 36.0 +/- 3.2 (p < 0.05); G1: 38.8 +/- 2.2 and 38.0 +/- 2.6; G2:
39.0 +/- 2.7 and 37.7 +/- 3.7; Hb (g/dl): GC: 12.5 +/- 1.2 and 11.9 +/- 1.3 (p <
0.05); G1: 12.6 +/- 1.1 and 12.8 +/- 1.1; G2: 12.9 +/- 0.9 and 12.2 +/- 1.5; PE
(microgram/dl red blood cells): GC: 30 +/- 17 and 43 +/- 22 (p < 0.01); G1: 26 +/
13 and 38 +/- 21 (p < 0.01); G2: 26 +/- 16 and 31 +/- 26; FERR (ng/ml): GC: 75
+/- 67 and 31 +/- 49 (p < 0.01); G1: 46 +/- 34 and 19 +/- 10 (p < 0.01); G2: 43
+/- 11 and 11 +/- 7 (p < 0.01). These results show: a) Fe administration was
efficient to mitigate Hb decrease; b) Fe stores decreased during pregnancy
regardless of Fe supplementation and frequency; c) EP values indicate that
intermittent Fe administration was more efficient to maintain normal
erythropoiesis.
PMID- 10684162
TI - [Syphilis in adolescent mothers in the city of Posadas, Province of Misiones].
AB - During three months (April to June 1997) 1,238 consecutive pregnant women were
studied at the time of delivery at the Madariaga public Hospital. Syphilis was
confirmed in 26 (2.1%) women, and 15 cases (57.7%) of congenital syphilis were
demonstrated in newborns one of whom was a stillborn. Of the syphilitic women
61.5% were 20 years old (average), 65.4% were single, 19.2% had a stable partner
and 15.4% were married; 70% of them had finished elementary school (seven years),
but despite this discrete level of instruction and that they were benefited with
free health attention, 73% of them had not started or completed the pregnancy
control. None of these women acted as sexual workers or were drug users; 57.7%
were unemployed and the remainder worked as domestic servants or were still going
to school. Menarca started at 13 (average) and the age of the first sexual
activity was 15 (average). The distribution of the cases of syphilis within the
city area shows four clusters that coincide with the lower income population, but
not with marginal groups. The failure to submit to medical control during
pregnancy among syphilitic women is directly linked with an increased risk for
congenital syphilis. The specific prevalence of syphilis in women (20 years old
or less) pregnant or not, shows an alarming hidden epidemic situation. An
interinstitutional and communitary program, with direct interventions within the
detected population clusters, is now underway in order to control syphilis.
Undesired pregnancy and syphilis seem to be associated with adolescent unsafe sex
conducts. A coordinated program between Public Health Service and National
Misiones University is operating, visiting home by home, in order to decrease or
eliminate congenital syphilis and is considered a priority health problem.
Unfortunately, if sexual conducts do not undergo changes in the near future, at
least by the correct use of condoms, HIV will replace syphilis.
PMID- 10684163
TI - Hematologic study of newborn umbilical cord blood.
AB - Hematological parameters in newborn umbilical cord blood samples (n = 476),
collected at the Hospital Provincial del Centenario, Rosario, were studied. They
were divided into 3 groups: (I) full term newborns with weight according to
gestational age; (II) low weight and normal gestational age; (III) preterm
newborns. The results were as follows: group (I) Hb: 15.5 +/- 1.1 g/dl; RBC; 4.66
+/- 0.33 x 10(12)/l; PCV: 49% +/- 4.3%, MCV 105.1 +/- 5.3 fl; MHC: 33.2 +/- 1.2
pg. Decreased Hb concentration (p < 0.05) and increased MCV (p < 0.01) were
observed in preterm newborns in comparison with normal ones, and a slight PCV
increase and RBC values in low weight newborns compared to the control group (p <
0.05). Erythrocyte morphology was normal as well as reticulocyte values in these
samples. The electrophoretic pattern was (FA) with the following Hb F values 66.3
+/- 6.8%, and Hb A2 0.45 +/- 0.3% in group (I), with a significant increase of Hb
F in 30-35 weeks preterm newborns. Group (I) values are considered as normal
hematological parameters in newborns in our country, whereas MCV < 94.7 fl is
considered as a neonatal microcytosis marker, consequently an alert to
investigate alpha-thalassemia. There was no influence on Hb concentration due to
maternal smoking habit. The present work could be of relevance for our region
since up to the present time there are no similar records.
PMID- 10684164
TI - [Vitamin D status in women living in Buenos Aires].
AB - Bone loss has both age-related and menopausal components. The causes of age
related bone loss are multifactorial. In order to establish vitamin D status in
women in our city (34 degrees S), calcidiol levels were assessed in 357
ambulatory women aged 40-90 years. One hundred and eighty were evaluated during
summer time and 177 during winter time. We also evaluated intact PTH values in a
subgroup of 231 women and this allowed us to document the prevalence of secondary
hyperparathyroidism. Summer levels of calcidiol were significantly higher than in
winter: 25.3 +/- 8.5 vs 21.3 +/- 7.4 ng/ml (p < 0.001). We found 4.4% of
calcidiol levels < 10 ng/ml (2.2% in summer and 6.6% in winter). Prevalence of
calcidiol between 10-20 ng/ml reached 67% in winter and went down to 25% during
summer. Prevalence of secondary hyperparathyroidism was 5.2%. Even though
prevalence of vitamin D deficiency was low, a great proportion of ambulatory
women had calcidiol levels between 10-20 ng/ml. These values would not be
sufficient for elderly people and could result in increased calcium mobilisation
and further bone loss.
PMID- 10684165
TI - [Utility of gas chromatography for the identification of mycobacterial species].
AB - The human immunodeficiency virus (HIV) epidemic has altered the epidemiological
profile of tuberculosis in both industrialized and developing countries. Serious
diseases caused by mycobacteria other than Mycobacterium tuberculosis, mostly
belonging to the M. avium-intracellulare complex (MAC), have become very common
in association with severe immunosuppression. The increase in mycobacterial
disease complexity has stimulated the development of more rapid and efficient
methods for diagnosis. In the present study, we investigated and assessed the
suitability of a gas-liquid chromatography technique for diagnosis of clinically
important mycobacteria in Argentina. An identification scheme was developed from
the results obtained in a previous study where we characterized the cellular
fatty acids and the mycolic acid cleavage products from most frequent species in
Argentina. Of 183 isolates tested, 69% were correctly identified to species level
and 5% were incorrectly classified. If we only take into account the isolates
that could be identified, 93% were correctly identified. Although all of the
isolates of M. tuberculosis were correctly identified, four isolates of MAC
incorrectly matched by M. tuberculosis. Gas chromatography provides a rapid
technique of highly predictive value for mycobacteria identification; it could be
used in reference laboratories as a rapid presumptive identification until the
biochemical tests are completed.
PMID- 10684166
TI - Absence of mutations in the p53 tumor suppressor gene in non-invasive Cushing
adenomas.
AB - A lot of evidence supports the existence of a monoclonal origin for pituitary
tumors, and several genetic alterations have already been confirmed as necessary
or sufficient for unrestrained cellular growth and pituitary function. The p53
gene, a known tumor-suppressor gene (TSG), encodes a protein that exerts
antiproliferative effects such as cell-growth arrest and apoptosis in response to
several types of stimuli. In fact, several human cancers are believed to be
caused by p53 mutations. In the case of pituitary tumors, p53 protein
accumulation has been described in ACTH-secreting pituitary adenomas. Since
increased amounts of the p53 protein are often related to mutations of its gene,
we decided to explore the existence of p53 mutations in the tumor tissues of 9
patients bearing non-invasive corticotropinomas, excised by the transphenoidal
route. We screened mutations in exons 5 to 8 of the p53 gene by the PCR-SSCP
analysis. We were not able to find any mutation in the exons investigated. Our
results are in close accordance with those obtained previously for other types of
pituitary tumors.
PMID- 10684167
TI - [Role of nitric oxide in the synthesis of prostaglandin F2 alpha and progesterone
during luteolysis in the rat].
AB - In the corpus luteum (CL) prostaglandin F2 alpha (PGF2 alpha) is a luteolytic
agent. Nitric oxide (NO) is a messenger molecule capable of modulating diverse
pathophysiological processes. Many of these functions are related with the female
reproductive tract. The aim of the present study was to investigate the role of
ovarian NO in PGF2 alpha production arid in progesterone synthesis during CL
regression in the rat. By means of the intrabursa (i.b.) ovarian sac treatment of
two competitive NO inhibitors, NG-monomethyl-L-arginine (L-NMMA; 1 mg/kg); NW
Nitro-L-arginine methyl ester (L-NAME, 3 mg/kg) and sodium nitroprusside (SNP,
0.05 mg/kg) as a NO generator we found that NO, produced by the ovarian tissue
during the last days (days 8 and 9) of CL development, acted by increasing PGF2
alpha production in the ovary and diminishing seric progesterone levels leading
to CL involution. We also postulated a positive feedback mechanism between PGF2
alpha and NO, to ensure luteal regression. Thus, we injected intraperitoneally
(i.p.) a luteolytic dose (3 micrograms/kg) of a synthetic PGF2 alpha during the
mid and late phase of CL development. The ovarian activity was evaluated. The
results confirmed our hypothesis; we did not see any effect in mid-stage of CL
development, while at a late stage enhancement of ovarian NOs activity was
observed in PGF2 alpha-infected animals.
PMID- 10684168
TI - [Anti glomerular basement membrane disease in a renal transplant patient with
Alport syndrome].
AB - We report a case of anti GBM disease that developed in the renal graft of a
patient with Alport syndrome. After reaching abnormal values of creatinine, the
patient presented with deteriorating renal function three months after a cadaver
transplant and the biopsy showed crescent formation, and linear IF deposits.
Circulating antibodies against alpha 5 chain of type IV collagen were found and
plasmaphereses stabilized the condition for one year until a lung infection led
to withdrawal of the immunosuppressive drugs and the patient returned to
dialysis. We discuss the possible mechanisms underlying the specificity of the
circulating antibodies in this case, which differs from the target characteristic
of the idiopathic form of anti GBM disease, the alpha 3 (IV) chain.
PMID- 10684169
TI - [Rosacea, vinegar and lemon, dysuria and Helicobacter pylori].
AB - A 52 year old male consulted his clinician because of dysuria, difficulty in
voiding and cutaneous lesions that were cured with high daily ingestion of acid
substances (vinegar and lemon). For the last 20 years he had made several
consultations without finding any solution to his problem. The patient was
advised to stop acid ingestion after which he presented disuria and skin lesions
compatible with rosacea. Due to the known association between this skin disorder
and gastric colonization with H. pylori an upper gastrointestinal endoscopy was
performed and the presence of the bacteria was confirmed. The patient received
specific treatment with permanent resolution of the symptoms. We repeated the
endoscopy with biopsy that did not show the presence of H. pylori. It is
suggested that gastric colonization with H. pylori could be related to irritative
symptoms of the lower urinary tract that are not due to other disease processes.
PMID- 10684170
TI - [Bronchiectasis, endothoracic goiter and hemoptysis].
PMID- 10684171
TI - [Biology of heat shock proteins].
AB - Hsp (Heat shock proteins) are a family of constitutive proteins of all pro and
eukariotic cells that play different physiological roles: they promote the
folding (acquisition of tertiary structure) assembly, translocation and secretion
of newly synthesized polypeptides and participate in the removal or repairing of
denatured proteins acting as molecular chaperons. This family of proteins is
composed by numerous members grouped according to their molecular weight. When
cells are subjected to different stresses such as hyperthermic shock, radiation,
toxins, viral infections, etc., Hsp are overexpressed. In this way, they exert a
cytoprotective effect, making the cells resistant to apoptosis. In humans, Hsp
are overexpressed in cancer cells from ovary, endometrium, breast, prostate,
digestive tract, etc. In some cases, overexpression is correlated with an
unfavorable outcome because these proteins could favour metastatic disease. Some
authors associate them not only with proliferation but also with differentiation
of the neoplastic tissue. Recent studies show their influence in resistance to
chemotherapeutic drugs. In autoimmune diseases like rheumatoid arthritis, Hsp can
suppress the inflammatory response. Nevertheless, their role in the immune system
has not been well established.
PMID- 10684172
TI - [Family violence. The physician's role].
AB - Family violence is mostly used against women. It is the cause of heavy
psychological and physical damages as well as social and economic costs. It also
has a repercussion on the future generations. Medical practitioners should be
prepared to recognise these situations in order to give support, counsel and
assistance to victims of abuse. Training in family violence should be included in
pre and post courses in Medical School programs.
PMID- 10684173
TI - [Participation of transcriptional factors in the regulation of lymphocyte
differentiation].
AB - The cytomorphological changes as well as the expression of certain markers in the
different stages of lymphocyte differentiation are well known. Studies carried
out on expression patterns of specific genes in lymphoid cells and their
regulatory mechanism have led to the identification of the fundamental mechanism
of cell development and activation. A great deal of knowledge has accumulated
concerning enhancers and promoters, the regulatory elements of those genes and
the transcriptional factors to which they bind. The present paper analyzes these
components and the participation of some of them such as PU.1, Ikaros, Aiolos,
GATA-3, Egf-1, E2A, EBF-1, PAX-5 (BSAP), TFE-3, Oct-1, Oct-2, and Nf-kappa B in
the regulation of the differentiation stages of cells belonging to the B and T
lymphoid lineages.
PMID- 10684174
TI - [Rethinking the pathogenesis of chronic chagasic cardiopathy at the closing of
the millennium].
PMID- 10684175
TI - [Recommendations on the ethics of withholding and/or withdrawing life-sustaining
treatment in the critically ill. Comite de Bioetica de la Sociedad Argentina de
Terapia Intensiva].
PMID- 10684176
TI - [Addio del passato. What kind of memory is musical memory?].
PMID- 10684177
TI - [Procedures in abattoirs and meat inspection. State of the discussion on the
implementation of alternative systems].
AB - Results of field studies which were performed in EU member states and which dealt
with meat inspection procedures in fattening pigs were reviewed with respect to
their contribution to alternative systems of meat inspection. The following was
concluded: Inspection ante mortem (monitoring of circumstances at the farm of
origin): Data which should be given to the notice of the authorities have not yet
been satisfactorily defined and their informative value still is not yet clear
The predictive character of information from the farm of origin regarding the
health status of the animals (results of meat inspection) is not yet sound enough
The technique of ante mortem inspection should be reconsidered also. Meat
inspection (monitoring and assessment of lesions): In all studies the compared
techniques (visual and official procedure) did not entirely find all lesions,
which were supposed to be on the carcasses and organs. This was true in different
percentages. The impact on consumer's health from the lesions monitored has to be
discussed more thoroughly. The information presently available is not yet sound
enough to generate a new practicable system of meat inspection. Further pilot
studies are necessary.
PMID- 10684178
TI - Effect of avilamycin, tylosin and ionophore anticoccidials on Clostridium
perfringens enterotoxaemia in chickens.
AB - In order to study the prophylactic and metaphylactic effect of antomicrobial
growth promoters and ionophorous anticoccidials on the incidence of Cl.
perfringens enterotoxaemia in chickens, experimental attempts were performed with
675 chickens in 27 trials. The birds were intraduodenally infected with Cl.
perfringens type A (ATCC 3624). The following antimicrobial growth promoters and
ionophore anticoccidials were used either on their own or in combination:
avilamycin, narasin, monensin and tylosin. While infected and non-medicated
trials showed an average incubation period of 1 week, clinical symptoms occurred
2-4 days later in infected and medicated birds. Avilamycin medicated birds had
the longest incubation period. In the infected and non-medicated trials, a
mortality rate of 16%-36% was noted within 3 weeks post infection. The avilamycin
trials showed a mortality rate of 0-8% (0-2 birds died) and the narasin and
monensin a mortality rate of 0-8%, respectively. In the combination groups
(monensin + avilamycin or narasin + avilamycin), the mortality rate ranged from 0
to 4%. Tylosin showed a very good metaphylactic/therapeutic effect against Cl.
perfringens enterotoxaemia. Following infection, medicated birds showed a
significantly better bodyweight gain than the chickens, whose feeds had not been
supplemented. From epidemiological point of view, the systematic prevention of
coccidiosis is a key in the control of Cl. perfringens enterotoxaemia in
chickens.
PMID- 10684179
TI - [Effect of mycotoxin contaminated feed on production parameters of dairy cows].
AB - Based on a feeding trial using 27 lactating "Simmental-cows" the effect of
naturally contaminated feed with deoxynivalenol (DON) as well as zearalenone
(ZON) regarding production parameters was examined. 3 groups of cows according to
lactation number, milk yield (kg ECM) and body mass were used. The average daily
intake of DON in group K was 12.4 mg, in group T 14.1 mg and in group M 14.3 mg
and ZON in group K was 12.4 mg, in group T 0.67 mg and in group M 0.68 mg
respectively. The feed of animals of group M was supplemented with "Mycofix Plus"
as mycotoxin inactivator. The red and white blood picture including the
thrombocytes were in all groups within the normal range. Concerning enzymes (GGT,
AP) and metabolites (GLUC, TBIL, UREA, CREA) the mean values of the 3 groups were
in the normal range. Slightly increased were the mean values of all groups in
respect to the AST- and GLDH-activities. Volatile fatty acids of the rumen
content were significantly highest in group M, also the number of dead rumen
infusoria was significantly decreased, but the counts of small sized infusoria
increased. The study has shown that "Mycofix Plus" might be able to enhance the
activity of rumen flora concerning detoxification of mycotoxins in feed of dairy
cows.
PMID- 10684180
TI - [Experience with simple ELISA test systems for Brucella serology in cattle, sheep
and goats].
AB - The objective of this work was to use the ELISA technique for the serological
surveillance for freedom of brucellosis of cattle, sheep and goats. By comparing
28 cattle sera taken after a brucellosis outbreak, 15 bovine sera supplied by the
Federal Institute for Health Protection of Consumers and Veterinary Medicine
(BgVV) and 497 serum slow agglutination test (SSAT) and complement fixation test
(CFT) negative bovine sera from herds officially declared free of brucellosis,
the ELISA technique not only shows higher sensitivity as compared to SSAT and CFT
but also distinguishes clearly between positive and negative reactions. The
serological comparison by SSAT, CFT and ELISA of 615 cattle, 624 sheep and 630
goat sera from herds acknowledged as brucellosis free showed equivalent
specificities for both CFT and ELISA. The specificity of the SSAT was much lower,
81.1% in cattle and 96.2% in goat sera. The examination of 5796 cattle, 1337
calf, 5031 sheep and 1796 goat sera demonstrates the advantage of the ELISA
technique as routine method. The possible application of the ELISA technique as a
screening method for serological brucellosis tests in sheep, goats and possibly
also in pigs is discussed.
PMID- 10684182
TI - On the presence of ganglion cells in the intracranial portion of the accessory
nerve (XI cranial nerve) in some mammals.
AB - The intracranial tract of the accessory nerve (XI cranial nerve) was studied in
some mammals (equines, domestic and wild ruminants, pig, carnivores, rabbit,
nutria, guinea pig, hamster, hedgehog). The specimens were embedded in paraffin
or paraplast, the sections were stained with cresyl violet, haematoxylin and
eosin, or submitted to argentic impregnation. Pseudounipolar ganglion cells were
found in all the mammals examined, with the exception of the cat. The number of
cells and their variability in the different species and subjects were related.
The topography and morphology of the cells were described. This comparative study
has demonstrated that the accessory nerve is not a entirely motor nerve, but it
is a mixed, motor and sensitive, nerve. Nevertheless, we think further studies
are necessary in order to establish the peripheral distribution, the central
pathway and the functional role of the pseudounipolar neurons found in the
intracranial tract of the accessory nerve.
PMID- 10684181
TI - Intertwined Sharpey fibers in human acellular cementum.
AB - We had carried out a detailed morphological study on the human acellular
extrinsic fiber cementum (AEFC) in order to support the exclusively extrinsic
origin of matrix collagen bundles. Mesial and distal cervical third of fresh
premolars from young individuals were examined. Semi-thin and thin section
clearly show the Sharpey fibres entering in the cementum at right-angle to the
root surface and coursing throughout the cementum to the cemento-dentinal
junction. On their way to the dentin the Sharpey fibres divide into smaller
bundles which, coursing obliquely or tangentially, intersect with others deriving
from neighbouring Sharpey fibres. Both de-proteinated and decalcified samples
observed at SEM present Sharpey fibres along the fractured surfaces entering and
running trough the cementum perpendicularly to the root surface. Fibril bundles
are seen branching out from the main body of a single Sharpey fibre and coursing
obliquely or perpendicularly to the original fibre. These morphological evidences
obtained both at TEM and SEM further confirm that in AEFC fibril bundles running
parallel or obliquely to the root surface are branches of Sharpey fibres and not
intrinsic cementum fibres.
PMID- 10684183
TI - Bone mineral density and anthropometric measures in normal and osteoporotic men.
AB - In an ethnically homogeneous men population living in Tuscany, Italy, the
relationship between age, height, body weight and bone mineral density were
studied. In 50 men bone mineral density was measured by Dual Energy X ray
Absorptiometry (DEXA). 13 subjects (26%) were osteoporotic. Age and bone mineral
density were not related (R2 = 0.052). Bone mineral density was associated with
body weight (R2 = 0.303), and height (R2 = 0.155). In osteoporotic men, mean (+/-
SD) body weight was Kg. 65.8 +/- 11.2, lower than that recorded in non
osteoporotic men, Kg. 77.3 +/- 10.2, (p = 0.0013). Age in osteoporotic and non
osteoporotic men did not differ (53.8 +/- 13.6 yrs and 60.9 +/- 11.8 yrs,
respectively; p = 0.077). In conclusion, anthropometric factors, as predictors of
bone disease, behave differently in women and men.
PMID- 10684184
TI - Placental morphometry in pregnancies complicated by intrauterine growth
retardation with absent or reversed end diastolic flow in the umbilical artery.
AB - The aim of this study was to assess any possible correlation between villous tree
architecture and its vascularization, and absent or reversed end-diastolic flow
velocity (ARED) in the umbilical artery. The study group included seven
pregnancies complicated by IUGR (estimated fetal weight < 10th percentile) and
absent end-diastolic flow velocity in the umbilical artery. A gestational-age
matched group of seven normally grown pregnancies was selected as control group.
At delivery, the placenta was weighed and immersed in 10% neutral buffered
formalin. A stratified random sampling procedure was used to obtain 12 blocks of
full-thickness tissue per organ. A single random section was cut from each block.
The following morphometric parameters were evaluated in each section: mean vessel
diameter, volume density of the villous tissue, stem villi and terminal villi.
Measurements were performed using a computerized Video Image Analysis system. No
significant difference in mean vessel diameter was found between the two groups
(37.1 microns versus 36.1 microns; p = 0.1). There was a significant reduction in
the proportion of total villous tissue in the ARED group (43% versus 52%): this
was due to a significant reduction in the volume of tissue occupied by the
terminal villi (14.1% versus 18.4%). No significant difference was found in the
proportion of villous tissue occupied by the stem villi (42% versus 40%). Several
studies have investigated the anatomical and/or vasomotor bases of absent end
diastolic flow velocity in the umbilical artery of fetuses with severe IUGR. Our
observations of a significant reduction in the proportion of villous tissue
occupied by the peripheral villi are consistent with the theory that failure of
normal development of the terminal villous is responsible for the increased
vascular resistance in IUGR pregnancies with ARED.
PMID- 10684185
TI - [Treatment of acute destructive alimentary pancreatitis].
AB - The paper reports treatment of 52 patients with acute destructive pancreatitis
for the period from 1993 to 1999. Up to 1997 conservative policy for management
of such patients was used, operative treatment was carried on only in pyoseptic
complications (43 patients, group 1). Later on early video-endoscopic procedures
(9 patients) aimed at removal of toxic exudate from the abdominal cavity, its
sanation and drainage with the use of not less than 5 drainage tubes were
employed. From 43 patients of group 1 10 died. There were no lethal outcomes in
group 2. The authors believe that early evacuation of the toxic purulent exudate
with lavage and drainage of the abdominal cavity promotes more effective
elimination of multiorganic insufficiency and decreases the risk for development
of pyoseptic complications.
PMID- 10684186
TI - [Humoral immunity and antigens of HLA system in acute pancreatitis].
AB - In the authors investigations patients with acute pancreatitis had antibodies to
endogenic antigens: to o-DNA--in 58.5%, to d-DNA--in 53.7%, to n-DNA in 51.2%, to
trypsin--in 42.7%, to insulin--in 28.1% and to the tissue antigen of the pancreas
-in 19.5%. A rise of serum immunoglobulins' and circulating immune complexes'
levels were established. Alterations of humoral immunity in connection with high
frequency of antigens HLA A1, B8, B18 associated with disregulation among T- and
B-links of immune system detected in patients with acute pancreatitis, represent
genetic and humoral mechanisms which mediate the development of autoimmune
reactions in this disease.
PMID- 10684187
TI - [Management of large and giant postoperative ventral hernias].
AB - The experience of the Department for Plastic Surgery of the A.V. Vishnevsky.
Institute of Surgery of RAMS in surgical treatment of 262 patients with
postoperative hernias of the anterior abdominal wall has been summarized for the
period from 1993 to 1998. 138 patients (test group) had large and giant hernias,
124 (control group)--small and middle-sized postoperative hernias. In large and
giant hernias more frequently (46.1%) combined plastic reconstruction of the
anterior abdominal wall was used rather than in small and middle-sized hernias
(21.5%). In the majority of patients in control group (78.5%) autoplasty of the
abdominal wall defect was carried out. In the long term period relapses developed
in 9 (7.0%) patients of the test group. In 7 cases the relapse developed after
the autoplasty (10.1%), and in 2 cases--after the use of combined method (3.4%).
This supports perspectiveness of the method of postoperative hernioplasty by the
combined method. Lethality rate after hernioplasty in the test group made up 2.3%
(3 patients).
PMID- 10684188
TI - [Surgical treatment of paracolostomu hernias and prolapses].
AB - The results of surgical treatment for paracolostomy hernias and prolapses in 71
patients show insufficient effectiveness of this method for surgical correction
of such paracolostomy complications as paracolostomy hernias and prolapses: the
rate of their relapses reaches 50%. The authors have developed a new effective
method for surgical treatment of complicated colostomy: intraabdominal
reconstruction of colostomy with retroperitoneal pull and laying of prestomal
segment of the sygmoid colon.
PMID- 10684189
TI - [Lychtenstein's hernioplasty in inguinal hernmias].
AB - The choice of plastic treatment of inguinal hernias is stile a problem. The rate
of relapses in conventional methods of hernioplasty averages 8%. The commonest
complications are nerves' injuries and damage to the arterial and venous vessels
of the spermatic cord. The hope for the decrease of complications rate is based
on implementation of "unstretched" surgery. The rate of relapses after
endoscopical hernioplasties varies from 0.8% after transabdominal preperitoneal
hernioplasty to 3.2%--after intraperitoneal one. Laparoscopic methods for
hernioplasty are technically complicated and expensive. The authors used
Lychtenstein's hernioplasty as an alternative to laparoscopic hernioplasty
methods. The technique is described according to which 76 operations were carried
out. The method is much easier than laparoscopical one. The course of the early
postoperative period is comparable with that one after laparoscopical operations.
It is stressed that Lychtenstein's hernioplasty should be considered as a method
of choice in majority of patients with inguinal hernias.
PMID- 10684190
TI - [Ultrasound examination in patients with peritonitis].
AB - Ultrasonographic features of developed intraabdominal complications were in 73
patients, in 43 of them being local and in 30-diffuse peritonitis. The diagnosis
was based on the complex manifestations of' sonographic changes of the small
bowel and other organs of the abdominal cavity which the authors suggest to
interpret as an ultrasound syndrome of "the bowel deficiency". The possibility of
dynamic ultrasound control in postoperative period for registration of the
features indicating elimination or progressing of peritonitis is shown.
PMID- 10684191
TI - [Provisional ileostomy as a treatment of postoperative purulent peritonitis].
AB - Early elimination of functional bowel obstruction in postoperative diffuse
purulent peritonitis (PDPP) is an important factor determining the outcomes of
the disease. Nasogastrointestinal drainage used for this purpose is capable to
adequately aspirate small bowel contents from the segments located at a distance
not farther than 80-100 cm. In the majority of patients with PDPP, lacking of
vital capacity of bowel wall as well as insufficiency of previously laid sutures
were revealed, which forced a surgeon to resort to resection; in such cases the
method of choice for decompression should be the application of terminal
ileostomy. Ileostomy in patients with PDPP provides adequate decompression of the
bowel. The optimal terms for elimination of ileostomy is 3-4 weeks
postoperatively.
PMID- 10684192
TI - [Ultrasound examination for diagnosis of postoperative peritonitis].
AB - 78 patients with peritonitis after various operations on the organs of abdominal
cavity were followed up. Ultrasound examinations (n = 86) were carried out in 59
patients. In 28 of them US has revealed abscesses of the abdominal cavity.
Comparative analysis showed coincidence of the diagnosis of peritonitis by
clinical and roentgenological data with the results of relaparotomy in 10 (58.8%)
of 17 examined patients. The same coincidence of the diagnosis of peritonitis by
clinical, roentgenological and sonographic data on one side and of the results of
relaparotomy on the other was found in 48 (81.4%) of 59 patients with
peritonitis. It is stated, that US examination considerably increases the
effectiveness of the diagnosis of postoperative peritonitis and incapsulated
cavities.
PMID- 10684193
TI - [Management of stomach cardial ulcers complicated by bleeding].
AB - The results of treatment of the patients with bleeding ulcers of cardial part of
the stomach have been analysed. In contrast to gastric ulcers of another
location, cardial ones are poorly respond conservative treatment, are usually
accompanied by severe complications, and are more frequently prone to malignant
transformation. New method for proximal resection of the stomach has been
developed, which was successfully used in 14 patients. There were no
complications and lethal outcomes. Yearly and long-term results were favourable.
PMID- 10684194
TI - [Gastrectomy with creation of small intestinal reservoir].
AB - A new variety of the esophago-intestinal anastomosis in gastrectomy is presented.
The application of the anastomosis begins with formation of the cuff around the
esophagus by the usage of the afferent and efferent loops, which then being
joined together in a shape f reservoir. A total of 113 patients with cancer of
the stomach (83), cancer of the gastric stump (10), giant ulcers of the cardial
part of the stomach complicated by bleeding (15), and Zollinger-Ellison (5)
syndrome have been operated on. Insufficiency of the anastomosis was revealed in
2 patients (1.8%). 6 patients (5.1%) died, 1 patient with insufficiency of the
esophageal anastomosis included. There were no clinical manifestations and
objective features of reflux-esophagitis after the usage of the suggested method
for anastomosis, the reservoir function after the resection of the stomach was
for the most part compensated.
PMID- 10684195
TI - [Therapeutic policy in rectal cancer].
AB - The results of clinical examination and treatment of 751 patients with rectal
cancer are presented. A total of 684 (91.0%) patients underwent radical surgery.
In 439 (64.2%) from them sphincter saving operations were carried out. The rate
of sphincter saving procedures for the last 5 years has increased up to 73.8%,
most often of them transbdominal resection was used--284 (64.7%) patients.
Sygmoidorectal anastomosis in 158 (55.6%) patients was carried out by the hand
sutures, and in 126 (44.4%)--suturing apparatuses were used. The operation was
finished by the suture of the pelvic peritoneum by two layers of sutures and the
drainage of the area of the anastomosis from the perineum site by two tubes for
prevention of the development of peritonitis even in case of insufficiency of the
anastomosis was made. All the operated patients underwent preoperative
radiotherapy with a total dose 20-25 Gy. The basic stage of the operation was on
demand followed by chemohyperthermic perfusion of the abdominal cavity. It was
carried out in 30 patients, including 12 patients with rectal cancer. In cancer
of the rectum of the II B and III stages the usage of chemotherapy is obligatory.
New operations for metastases of cancer of the colon into the liver were made in
4 patients (left and extended right hemihepatectomy). Complications developed in
33.5% of patients, lethality made up 3.8%, including 1.8% for the last 5 years.
PMID- 10684196
TI - [Advisability of combined operations in proctologic patients].
AB - The analysis of surgical treatment for combined diseases of the anorectal region
in 106 patients is presented. The mean duration of the hospital stay after one
stage procedures made up 10.8 days, whereas in proctological patients with a
single disease it made up 9 days. The individual approach to the choice of
surgical policy and keeping to the order of the stages of the operation are
essential in treatment of patients with combined diseases. The results of the
study support the use of combined operations in patients with disease of the
colon and the anorectal area.
PMID- 10684197
TI - [Radiofrequency electrostimulation of sympathetic nerve boundary trunk in
patients with bronchial asthma].
AB - In 7 patients aged from 43 to 64 years with severe infectious allergic forms of
bronchial asthma with curative aims radiofrequency electrostimulator for the
boundary trunk of the sympathic nerve (BTSN) has been implanted in the neck.
Daily sessions of electrostimulation (ES) by the current with parameters 1-100
Hz, 0.1-0.4 m/s, 0.1-2.0 V adjusted individually by maximal broncholytic and
clinical effects were performed for 5 years. It was established that ES of BTSN
can produce both bronchial dilatation and bronchial spasm. Application of ES of
BTSN has resulted in a decrease of bronchial hyperreactivity, frequency of
asthmatic attacks 2.6-3.2 fold in consumption of antiasthmatic drugs 2.4-2.7
fold. The only complication has been detected--rejection of the electrostimulator
due to the defect of its capsule. This method can be applied as an adjuvant in
therapy of severe forms of bronchial asthma resistant to drug treatment.
PMID- 10684198
TI - [Systemic inflammatory response syndrome and sepsis in maxillofacial surgery
clinic].
AB - A total of 106 patients with surgical infection in maxillofacial region were
studied. Clinical and laboratory diagnostic data on surgical infection and sepsis
in maxillofacial surgery are presented. Integral indices of blood circulation,
respiration, brain and liver metabolism, regarding severity of surgical infection
were determined. Pathogenetically substantiated therapy of sepsis is proposed.
PMID- 10684199
TI - [Registration of superficial acoustic waves velocity (SAWV) in prognosis and
diagnosis of wound healing].
AB - A new method of objective diagnostic express-monitoring of a wound healing course
has been developed for prognosis and evaluation of effectiveness of the treatment
for various purulent wounds. The method is based on measurement of SAWV in the
skin integument surrounding festered wound. Portable device-acoustic skin
analyser (ASA) was used for the measurement of SAWW. The following results were
obtained in 273 patients: in phase I of healing process in the first period SAWV
was 35.0-49.9 m/s; in the second period of phase I of wound healing it was 50.0
90.0 m/s; in phase II--35.0-49.0 m/s; in phase III--25.0-34.9 m/s. SAWV in
healthy skin is 18-24.9 m/sec. These measurements of SAWV completely correlated
with cytological and hystological examination data.
PMID- 10684200
TI - [Up-to=date view on medical documentation in surgical clinic].
AB - Computer variants of the fragments of clinical records were developed. They
represent the parts: "Title-page", "Examination of surgical patient in the
admission department", "Protocol of laparoscopic cholecystectomy". During
modelling of the intellectual contents of the modules the principle of the
formalized protocol was used, which has been realized with use of a context
depending menu. According to the authors opinion, newly developed programs
provide objective and correct reflection of any clinical and surgical situation,
use of standardized terminology and classifications, save the surgeons the
trouble of "scribbling" and decrease time-consuming registration of medical
records, provide specialized information, prevent possible diagnostic and
technical errors, and give physicians, legal defence.
PMID- 10684201
TI - [Extra-anatomical shunting of femoral artery in purulent wound].
PMID- 10684202
TI - [Cancer of appendix complicated destructive appendicitis].
PMID- 10684203
TI - [Isolated injuries of gallbladder].
PMID- 10684204
TI - [Patient's quality of life after surgical treatment].
PMID- 10684205
TI - [I.M. Popov'ian - physician, researcher, public figure].
PMID- 10684206
TI - [Angina pectoris, left ventricular dysfunction and age].
PMID- 10684207
TI - [Atherosclerosis: some topical issues of pathogenesis, diagnosis, treatment and
prevention].
PMID- 10684208
TI - [Autoimmune and rheumatic aspects of HCV infection (lecture)].
PMID- 10684209
TI - [Present-day infectious endocarditis (part i)].
PMID- 10684210
TI - [Treatment of arterial hypertension in patients with bronchial asthma].
AB - Treatment of arterial hypertension in patients with concurrent chronic
obstructive diseases of the lungs has limits in prescription of antihypertensive
drugs. STAMLO--long-acting calcium antagonist--is proposed for monotherapy of
mild and moderate hypertension in patients with bronchial asthma. The drug
decreases hypertension in the greater and lesser circulation, improves bronchial
permeability.
PMID- 10684211
TI - [Cellular activity in healthy subjects with cardiovascular integral risk
factors].
AB - The study was made of permeability of erythrocytic membrane (PEM), electrokinetic
properties of cellular nucleus (ECN) and phagocytic activity of neutrophils (PAN)
in whole blood of 130 healthy subjects with integral risk factors of
cardiovascular disease. First-level test immunogram was analysed.
Hypercholesterolemia and hyperbetalipidemia were associated with high PAN. Obese
patients with cardiovascular hereditary load had elevated PAN and PEM. In smokers
PEM was elevated but ECN was subnormal, PAN rose in parallel with number of
cigarettes smoked for a day. Combination of the risk factors led to low activity
of the nucleus and high PAN. It is concluded that healthy subjects with integral
risk factors develop changes in functional cell activity.
PMID- 10684213
TI - [Polymagnetolaser correction of vegetative and bioelectric imbalance in patients
with duodenal ulcer].
AB - 90 patients with duodenal ulcer in exacerbation were divided into two groups.
Control patients have received drugs against Helicobacter pylori (Hp). In
addition to it, the test subjects were exposed to transcutaneous and reflex
magnetolaser impact with consideration of baseline vegetative and bioelectric
balance as shown by mathematical analysis of cardiac rhythm and Nakatani
acupuncture diagnosis, monitoring of biopotentials of biologically active points.
Impacts on general regulation systems in combined differential therapy of ulcer
shorten ulcer healing, promote eradication of Hp, improve the condition of
gastroduodenal mucosa.
PMID- 10684212
TI - [Role of bronchospasm in impairment of bronchial permeability in bronchial asthma
in attack-free period].
AB - Lung capacity (LC), functional lung capacity (FLC), FEV1, FEV1/LC%, CO25, CO50,
CO75 were measured in 56 patients with bronchial asthma in attach-free period
before and after inhalation of one-dose berotec and one-dose atrovent.
Bronchospasm was registered in 66% of the patients. It was the only cause of
bronchial obstruction in 12% of the patients and one of the causes in 54% of
them. Contribution of the bronchospasm to development of bronchial obstruction
was, as a rule, dominating. This contribution reached 81-100% in 60% of the
patients.
PMID- 10684214
TI - [Features of angina pectoris in patients with non-insulin-dependent diabetes
mellitus (NIDDM)].
AB - Detailed clinicofunctional examination of anginal patients with NIDDM using
variation pulsometry and electrophysiological cardiac tests in 110 patients (89
females and 21 males aged 36-79 years, mean 64.3 +/- 5.2 years) has revealed that
atypical cardialgia, arterial hypertension, obesity was present in 28.1, 76.4 and
85.4% of anginal patients with NIDDM. Sympathicotonia was registered in autonomic
heart regulation of 83% of them. Anginal patients exhibited also suppression of
sinus node automatism and sinoatrial conduction. When NIDDM is severe, pacemaker
activity of the sinus node intensified suggesting development of cardial diabetic
neuropathy.
PMID- 10684215
TI - [Vegetative regulation of arterial pressure in patients with arterial
hypertension and non-insulin-dependent diabetes mellitus (NIDDM)].
AB - 72 patients with NIDDM (duration 5.3 +/- 3.1 years) aged 41-60 years were
examined. They had also mild or moderate hypertension (duration 12.1 +/- 4.5).
Control groups consisted of 15 NIDDM patients free of hypertension, 15
hypertensive patients without diabetes, 15 healthy subjects. All the patients
have undergone 24-h monitoring of arterial pressure (APM) and computed
cardiointervalography (CIG). As shown by CIG, hypertensive patients with NIDDM
had sympathotonia which resulted from hypofunction of parasympathetic and
hyperfunction of the sympathetic nervous systems. APM demonstrated enhanced
variability of arterial pressure and its inadequate fall at night in patients of
this group and normotensive patients with diabetes.
PMID- 10684216
TI - [Efficacy of emoxipin in treatment of arterial hypertension in the Far North].
AB - A total of 95 hypertensive men working in duty regimen in the extreme North were
examined. The men were found to have lipid metabolism disorders, activation of
lipid peroxidation, decreased antioxidant defense in red cell membranes in all
the examinees vs control hypertensive men living in moderate climatic zone.
Effect of 2-week monotherapy with emoxipin was studied in 29 males with mild
arterial hypertension free of obesity and coexisting diseases. Placebo was given
to 10 patients. Emoxipin had an antihypertensive and antioxidant effects,
improved structural-functional condition of erythrocytes in hypertensive
patients.
PMID- 10684217
TI - [Effect of ACE inhibitor (ednit) on portal hemodynamics in patients with hepatic
cirrhosis].
PMID- 10684218
TI - [New approaches to prevention of stomach cancer in employees of chemical plants].
PMID- 10684219
TI - [Long-term atrovent treatment of chronic obstructive bronchitis].
PMID- 10684220
TI - [Medicine in Academy of Sciences in "century of Enlightenment" (the 275th
anniversary of Russian Academy of Sciences)].
PMID- 10684221
TI - [There is something wrong in the studies of mammography! No support for the
conclusions on benefits of breast cancer screening].
PMID- 10684222
TI - [Incidence and mortality of breast cancer during a 25-year period. International
and regional comparisons].
PMID- 10684223
TI - [Spontaneous premature birth: physiopathology, predictors and management. The
frequency is constant--early detection can improve therapeutic possibilities].
AB - Premature birth is associated with increased perinatal morbidity and mortality.
Spontaneous premature birth can be understood as a syndrome with a number of
underlying causes including infection, maternal stress, uterine distention,
placental hypoxia, bleeding and lack of prostaglandin dehydrogenase. Infection is
probably the most important factor at low gestational age, with uterine
distention and maternal stress increasing in significance further on. In the
future we may become better able than we are at determining the specific reason
in each individual case, which may lead to the development of more effective
treatment. On the other hand, results have been very poor with respect to
prevention, and in some countries we even note a slight increase in incidence.
Although premature birth is often impossible to prevent, early detection and
tocolytic therapy can delay labor long enough to permit effective corticosteroid
therapy and transport when required to the appropriate obstetric clinic for
optimal neonatal care.
PMID- 10684224
TI - [Fetal virus infection a risk factor of diabetes mellitus type 1 in children].
AB - The incidence of type-1 diabetes mellitus is high and increasing in Sweden. The
etiology of IDDM is complex: several genes appear to interact with each other and
with various nongenetic risk factors to induce and complete the autoimmune
destruction of beta-cells. IDDM has its onset most often in childhood, and during
the past decade incidence is increasing specifically among children under the age
of five. Factors initiating the process should thus be sought in early life. A
number of recent studies have identified perinatal events as risk determinants;
among these, fetal viral infections may be causally related to the disease and
may become targets for intervention and prevention.
PMID- 10684225
TI - [Perinatal factors can be risk factors of diabetic nephropathy].
AB - This article discusses the association of perinatal risk determinants and the
future development of diabetic nephropathy. A low birth-weight seems to increase
the risk for future cardiovascular disease, hypertension and insulin resistance,
all of which are features of diabetic nephropathy. In a nation-wide case
controlled study we found that smoking during pregnancy and low maternal
education, rather than low birth weight per se increase the risk of developing
incipient nephropathy in offspring with type-1 diabetes. These factors are in
addition to, and independent of, a familial disposition for cardiovascular
disease and hypertension. Persistent hyperglycaemia is a prerequisite for the
influence of these factors. Our findings support the hypothesis of a
multifactorial aetiology of diabetic nephropathy.
PMID- 10684226
TI - [When insight on disease is halting. I. Clinical assessment of impaired insight-
current research summarized].
AB - This review explores the definition, assessment and possible restoration of
impaired insight in psychosis. Hypotheses concerning the neuropsychological
correlates of insight impairment are discussed. The distinction between impaired
insight in psychosis and impaired awareness and psychological denial in other
medical conditions is emphasised.
PMID- 10684227
TI - [When disease insight is halting. II. The neurobiological underpinnings].
AB - This review examines the neurobiological underpinnings of impaired insight and
awareness in psychosis. Crucial mainly dopaminergic pathways are discussed in
relation to delusions and hallucinations. Thirty percent of psychotic patients
with impaired insight will not respond to traditional neuroleptic drug treatment,
and the possibility that multifocal brain etiology might underlie such cases is
discussed. It is suggested that severe cases of thought process disorder in
psychosis may result from such multifocal processes.
PMID- 10684228
TI - [Don't miss prolactinoma! On the importance of measuring prolactin and how it is
done].
AB - Prolactinoma is the most common functional pituitary tumor. Since appropriate
treatment is often pharmacological rather than surgical, all patients with a
tumor within or close to the sella turcica should be evaluated for prolactinoma
before being sent for neurosurgery. Preanalytical factors affecting serum
prolactin concentration should be taken into account when planning blood
sampling. Diagnostic laboratories should aim for the use of common international
calibrators and a common unitage for expressing concentrations. Assays should be
carried out in such a way that the risk of falsely high or low values is
minimized. Any patient with high values due to an immunometric method should be
evaluated for the possible presence of endogenous antibodies against prolactin
("macroprolactinemia").
PMID- 10684229
TI - [Europe without borders--who will take care of the protection against
infections?].
PMID- 10684230
TI - [Scientists and humanists can bridge over the differences of their specialties].
PMID- 10684231
TI - [A reflection on the effect of medical knowledge on man].
PMID- 10684232
TI - [Future of school health services. Concentrate on the good parts of Swedish
health care!].
PMID- 10684233
TI - [How really dangerous is spinal manipulation?].
PMID- 10684234
TI - [Halting primary health care--what does the Medical Society do?].
PMID- 10684235
TI - [To master severe epilepsy requires multicompetent measures].
PMID- 10684236
TI - [Efficient cytologic screening: selective and in combination with HPV test].
PMID- 10684237
TI - [Automated quantitative image cytometry of bronchial washings in suspected lung
cancer: comparison with cytology, histology and clinical diagnosis].
AB - INTRODUCTION: Automated image cytometry represents a new method for the
quantitative analysis of nuclear structure and DNA-content of exfoliative airway
epithelial cells. In the present investigation, we examined the correlation
between automated cytometry, conventional cytology and histopathology with the
final diagnosis as the "gold standard". METHODS: In 142 patients (100 males and
42 females) with suspected lung cancer and 50 controls (COPD, asthma), bronchial
washings (5-10 ml) were obtained during bronchoscopy before taking biopsies for
cytological and/or histological examinations. The washings were collected in 20
ml Saccomanno's fixative and centrifuged (500 g, 15 min). The cell pellet was
resuspended in Saccomanno's solution. Two specimens were stained according to
Papanicolaou and another two using the Feulgen reaction with thionine. Image
cytometry was performed by means of a special, trainable classifier for
exfoliative cells of the respiratory tract, using the Cyto-Sacant (Oncometrics,
Vancouver). RESULTS: In the patients with suspected lung cancer we found numerous
abnormal nuclei in 97 samples, 36 samples contained normal cells only, and 9
samples were insufficient. In our control group there was no sample with abnormal
nuclei, and all washings were evaluable. Compared to the final diagnosis of lung
cancer, we found a sensitivity of 90% (92/102) and a specificity of 84% (26/31).
For histology sensitivity was 91% (73/80) and specificity 100%, while we found a
sensitivity of 92% (92/100) and specificity of 100% for cytology. For automated
cytometry the positive predicted value was 95%, the negative predicted value 71%.
CONCLUSIONS: In the investigation of patients with suspected lung cancer,
automated image cytometry of bronchial washings is a sensitive and reliable
method for the detection of malignant changes in the tracheobronchial mucosa. The
automated procedure seems well suited not only for analysing bronchial washings,
but also for a screening procedure.
PMID- 10684238
TI - [Irrigation drainage and fibrinolysis for treatment of parapneumonial pleural
empyema].
AB - We report on our experiences on 336 patients suffering from manifest pleural
empyema within a period of 10 years (1985-1995). Considering the pathogenesis,
particularly the results of 218 patients with "parapneumonic pleural empyema"
were analysed retrospectively. Definite healing could be achieved by chest tube
placement and pleural irrigation in 201 patients (= 92.2%). Other 11 patients
finally needed surgical interventions (= 5%). Only 6 patients could not be cured:
An indwelling tube was palliatively inserted once and 5 patients died in the
course of the medical treatment (mortality = 2.3%). Within the first years the
irrigation therapy was performed using a single chest tube (n = 38%) but since
1989 a double-lumen drainage was used (n = 158). Since 1987 in most cases (n =
182) intrapleural medicinal fibrinolysis was performed by instillation of
streptokinase (Varidase N). If outward invasively pretreated patients (n = 30)
are analysed separately, a statistical dependency can be found between the
duration and the way of treatment. Without significant difference between the
groups (Gr) the average duration of treatment using a single tube without
fibrinolysis (Gr1) was 31.8 days, but 26.5 days using a single tube combined with
fibrinolysis (Gr2). A clear shortening of the duration is detectable if patients
were treated with a combination of double lumen drainage and fibrinolysis: If 2
tubes were used (Gr4) the treatment lasted 20.6 days, using one double-lumen tube
(Gr5) it took 19.8 days. There is a proof of significance at comparison of Gr4
with Gr1 (p = 0.005). Gr5 with Gr1 (p < 0.001) and Gr5 with Gr2 (p = 0.014)
respectively. A significant longer duration of treatment (40.6 days, p < 0.001)
is found for the group of the pretreated patients, if compared with the
corresponding groups Gr4 or Gr5. CONCLUSION: Parapneumonic empyemas most often
can be cured by irrigation drainage. The mortality is comparatively low. The
shortest duration of treatment is needed using the combination of a double-lumen
tube with intrapleural instillation of a fibrinolytic agent (Varidase N).
Invasively pretreated patients need significantly longer durations at same form
of treatment.
PMID- 10684239
TI - [Alveolar proteinosis. Case report and review of a rare disease entity].
PMID- 10684240
TI - [Geographic and economic aspects of inhalation therapy].
PMID- 10684241
TI - [Pulmonary trichomoniasis: diagnosis based on identification of irritation in
bronchoalveolar lavage].
AB - Bronchopulmonary infections caused by trichomonads have been reported mainly in
patients with pre-existing pulmonary or debilitating disease (e.g. bronchial
carcinoma, lung abscess, bronchiectasis). Pulmonary trichomoniasis is most often
due to infection with Trichomonas tenax, usually regarded as a harmless commensal
of the human mouth, and may rarely be caused by other trichomonas species. A 45
year old female presented with a dry cough, exertional dyspnoea and malaise.
These symptoms persisted for 6 months regardless of anti-inflammatory and anti
obstructive inhalative therapy. Sarcoidosis of the lungs, diagnosed 20 years
prior, had been asymptomatic since and there was no coexistent disease.
Laboratory data revealed increased ACE-levels (90 IE/ml) and lung function showed
bronchial hyperreactivity on histamine challenge. No other abnormalities were
found (chest x-ray, bronchoscopy, lung function test, blood count and serum
calcium). The diagnosis was based on the cytological identification of numerous
trophozoites of T. tenax in the bronchoalveolar lavage. Therapy with oral
metronidazol for 40 days led to complete recovery from symptoms and normalisation
of ACE serum levels. The patient has remained well for 12 months since. The
pathogenicity of oral trichomonads in the non-immunocompromised host remains
uncertain. Our patient had no known medical risk factors by comparison with
published cases. The case illustrates the clinical relevance of pulmonary
trichomoniasis in an otherwise healthy person.
PMID- 10684242
TI - [Abscessed pneumonia caused by Pseudomonas aeruginosa as an occupational disease
in a metal driller].
AB - We report the case of a 29-year-old man without immunodeficiency who acquired
Pseudomonas aeruginosa pneumonia complicated by pulmonary abscess. The source of
infection could be identified as aerosolized metalworking fluid at his workplace
contaminated with Pseudomonas aeruginosa. A high titer of specific IgG antibodies
(type-III-sensitization, Gell & Coombs) against Pseudomonas aeruginosa has been
identified in the patients serum as an indicator for longstanding occupational
airborne exposure to contaminated metalworking fluid. This community-acquired
pneumonia has been reported to the industrial injuries insurance as an
occupational disease for discussion of legal consequences and development of
effective measures of prevention.
PMID- 10684243
TI - [Asthma self care according to the traffic light principle: which peak flow,
which guidelines?].
PMID- 10684244
TI - [Fast-acting combinations of inhalable corticoids and long-acting beta2
sympathomimetics as long-term therapy of bronchial asthma. Opinions of an expert
group. R. Buhl et al. Pneumology 53 (1999) 210-212].
PMID- 10684245
TI - Drosophila apoptosis and Bcl-2 genes: outliers fly in.
PMID- 10684246
TI - Spatial separation of parental genomes in preimplantation mouse embryos.
AB - We have used two different experimental approaches to demonstrate topological
separation of parental genomes in preimplantation mouse embryos: mouse eggs
fertilized with 5-bromodeoxyuridine (BrdU)-labeled sperm followed by detection of
BrdU in early diploid embryos, and differential heterochromatin staining in mouse
interspecific hybrid embryos. Separation of chromatin according to parental
origin was preserved up to the four-cell embryo stage and then gradually
disappeared. In F1 hybrid animals, genome separation was also observed in a
proportion of somatic cells. Separate nuclear compartments during preimplantation
development, when extreme chromatin remodelling occurs, and possibly in some
differentiated cell types, may be associated with epigenetic reprogramming.
PMID- 10684247
TI - The yeast nuclear pore complex: composition, architecture, and transport
mechanism.
AB - An understanding of how the nuclear pore complex (NPC) mediates nucleocytoplasmic
exchange requires a comprehensive inventory of the molecular components of the
NPC and a knowledge of how each component contributes to the overall structure of
this large molecular translocation machine. Therefore, we have taken a
comprehensive approach to classify all components of the yeast NPC
(nucleoporins). This involved identifying all the proteins present in a highly
enriched NPC fraction, determining which of these proteins were nucleoporins, and
localizing each nucleoporin within the NPC. Using these data, we present a map of
the molecular architecture of the yeast NPC and provide evidence for a Brownian
affinity gating mechanism for nucleocytoplasmic transport.
PMID- 10684248
TI - Assembly of smooth muscle myosin by the 38k protein, a homologue of a subunit of
pre-mRNA splicing factor-2.
AB - Smooth muscle myosin in the dephosphorylated state does not form filaments in
vitro. However, thick filaments, which are composed of myosin and myosin-binding
protein(s), persist in smooth muscle cells, even if myosin is subjected to the
phosphorylation- dephosphorylation cycle. The characterization of telokin as a
myosin-assembling protein successfully explained the discrepancy. However, smooth
muscle cells that are devoid of telokin have been observed. We expected to find
another ubiquitous protein with a similar role, and attempted to purify it from
chicken gizzard. The 38k protein bound to both phosphorylated and
dephosphorylated myosin to a similar extent. The effect of the myosin-binding
activity was to assemble dephosphorylated myosin into filaments, although it had
no effect on the phosphorylated myosin. The 38k protein bound to myosin with both
COOH-terminal 20 and NH(2)-terminal 28 residues of the 38k protein being
essential for myosin binding. The amino acid sequence of the 38k protein was not
homologous to telokin, but to human p32, which was originally found in nuclei as
a subunit of pre-mRNA splicing factor-2. Western blotting showed that the protein
was expressed in various smooth muscles. Immunofluorescence microscopy with
cultured smooth muscle cells revealed colocalization of the 38k protein with
myosin and with other cytoskeletal elements. The absence of nuclear
immunostaining was discussed in relation to smooth muscle differentiation.
PMID- 10684249
TI - Gelsolin deficiency blocks podosome assembly and produces increased bone mass and
strength.
AB - Osteoclasts are unique cells that utilize podosomes instead of focal adhesions
for matrix attachment and cytoskeletal remodeling during motility. We have shown
that osteopontin (OP) binding to the alpha(v)beta(3) integrin of osteoclast
podosomes stimulated cytoskeletal reorganization and bone resorption by
activating a heteromultimeric signaling complex that includes gelsolin, pp(60c
src), and phosphatidylinositol 3'-kinase. Here we demonstrate that gelsolin
deficiency blocks podosome assembly and alpha(v)beta(3)-stimulated signaling
related to motility in gelsolin-null mice. Gelsolin-deficient osteoclasts were
hypomotile due to retarded remodeling of the actin cytoskeleton. They failed to
respond to the autocrine factor, OP, with stimulation of motility and bone
resorption. Gelsolin deficiency was associated with normal skeletal development
and endochondral bone growth. However, gelsolin-null mice had mildly abnormal
epiphyseal structure, retained cartilage proteoglycans in metaphyseal trabeculae,
and increased trabecular thickness. With age, the gelsolin-deficient mice
expressed increased trabecular and cortical bone thickness producing mechanically
stronger bones. These observations demonstrate the critical role of gelsolin in
podosome assembly, rapid cell movements, and signal transduction through the
alpha(v)beta(3) integrin.
PMID- 10684250
TI - Regulation of skeletal progenitor differentiation by the BMP and retinoid
signaling pathways.
AB - The generation of the paraxial skeleton requires that commitment and
differentiation of skeletal progenitors is precisely coordinated during limb
outgrowth. Several signaling molecules have been identified that are important in
specifying the pattern of these skeletal primordia. Very little is known,
however, about the mechanisms regulating the differentiation of limb mesenchyme
into chondrocytes. Overexpression of RARalpha in transgenic animals interferes
with chondrogenesis and leads to appendicular skeletal defects (Cash, D.E., C.B.
Bock, K. Schughart, E. Linney, and T.M. Underhill. 1997. J. Cell Biol. 136:445
457). Further analysis of these animals shows that expression of the transgene in
chondroprogenitors maintains a prechondrogenic phenotype and prevents
chondroblast differentiation even in the presence of BMPs, which are known
stimulators of cartilage formation. Moreover, an RAR antagonist accelerates
chondroblast differentiation as demonstrated by the emergence of collagen type II
expressing cells much earlier than in control or BMP-treated cultures. Addition
of Noggin to limb mesenchyme cultures inhibits cartilage formation and the
appearance of precartilaginous condensations. In contrast, abrogation of retinoid
signaling is sufficient to induce the expression of the chondroblastic phenotype
in the presence of Noggin. These findings show that BMP and RAR-signaling
pathways appear to operate independently to coordinate skeletal development, and
that retinoid signaling can function in a BMP-independent manner to induce
cartilage formation. Thus, retinoid signaling appears to play a novel and
unexpected role in skeletogenesis by regulating the emergence of chondroblasts
from skeletal progenitors.
PMID- 10684251
TI - Interaction among GSK-3, GBP, axin, and APC in Xenopus axis specification.
AB - Glycogen synthase kinase 3 (GSK-3) is a constitutively active kinase that
negatively regulates its substrates, one of which is beta-catenin, a downstream
effector of the Wnt signaling pathway that is required for dorsal-ventral axis
specification in the Xenopus embryo. GSK-3 activity is regulated through the
opposing activities of multiple proteins. Axin, GSK-3, and beta-catenin form a
complex that promotes the GSK-3-mediated phosphorylation and subsequent
degradation of beta-catenin. Adenomatous polyposis coli (APC) joins the complex
and downregulates beta-catenin in mammalian cells, but its role in Xenopus is
less clear. In contrast, GBP, which is required for axis formation in Xenopus,
binds and inhibits GSK-3. We show here that GSK-3 binding protein (GBP) inhibits
GSK-3, in part, by preventing Axin from binding GSK-3. Similarly, we present
evidence that a dominant-negative GSK-3 mutant, which causes the same effects as
GBP, keeps endogenous GSK-3 from binding to Axin. We show that GBP also functions
by preventing the GSK-3-mediated phosphorylation of a protein substrate without
eliminating its catalytic activity. Finally, we show that the previously
demonstrated axis-inducing property of overexpressed APC is attributable to its
ability to stabilize cytoplasmic beta-catenin levels, demonstrating that APC is
impinging upon the canonical Wnt pathway in this model system. These results
contribute to our growing understanding of how GSK-3 regulation in the early
embryo leads to regional differences in beta-catenin levels and establishment of
the dorsal axis.
PMID- 10684252
TI - Debcl, a proapoptotic Bcl-2 homologue, is a component of the Drosophila
melanogaster cell death machinery.
AB - Bcl-2 family of proteins are key regulators of apoptosis. Both proapoptotic and
antiapoptotic members of this family are found in mammalian cells, but no such
proteins have been described in insects. Here, we report the identification and
characterization of Debcl, the first Bcl-2 homologue in Drosophila melanogaster.
Structurally, Debcl is similar to Bax-like proapoptotic Bcl-2 family members.
Ectopic expression of Debcl in cultured cells and in transgenic flies causes
apoptosis, which is inhibited by coexpression of the baculovirus caspase
inhibitor P35, indicating that Debcl is a proapoptotic protein that functions in
a caspase-dependent manner. debcl expression correlates with developmental cell
death in specific Drosophila tissues. We also show that debcl genetically
interacts with diap1 and dark, and that debcl-mediated apoptosis is not affected
by gene dosage of rpr, hid, and grim. Biochemically, Debcl can interact with
several mammalian and viral prosurvival Bcl-2 family members, but not with the
proapoptotic members, suggesting that it may regulate apoptosis by antagonizing
prosurvival Bcl-2 proteins. RNA interference studies indicate that Debcl is
required for developmental apoptosis in Drosophila embryos. These results suggest
that the main components of the mammalian apoptosis machinery are conserved in
insects.
PMID- 10684253
TI - Intracellular distribution of mammalian protein kinase A catalytic subunit
altered by conserved Asn2 deamidation.
AB - The catalytic (C) subunit of protein kinase A functions both in the cytoplasm and
the nucleus. A major charge variant representing about one third of the enzyme in
striated muscle results from deamidation in vivo of the Asn2 residue at the
conserved NH(2)-terminal sequence myrGly-Asn-Ala (Jedrzejewski, P.T., A. Girod,
A. Tholey, N. Konig, S. Thullner, V. Kinzel, and D. Bossemeyer. 1998. Protein
Sci. 7:457-469). Because of the increase of electronegativity by generation of
Asp2, it is reminiscent of a myristoyl-electrostatic switch. To compare the
intracellular distribution of the enzymes, both forms of porcine or bovine heart
enzyme were microinjected into the cytoplasm of mouse NIH 3T3 cells after
conjugation with fluorescein, rhodamine, or in unlabeled form. The
nuclear/cytoplasmic fluorescence ratio (N/C) was analyzed in the presence of cAMP
(in the case of unlabeled enzyme by antibodies). Under all circumstances, the N/C
ratio obtained with the encoded Asn2 form was significantly higher than that with
the deamidated, Asp2 form; i.e., the Asn2 form reached a larger nuclear
concentration than the Asp2 form. Comparable data were obtained with a human cell
line. The differential intracellular distribution of both enzyme forms is also
reflected by functional data. It correlates with the degree of phosphorylation of
the key serine in CREB family transcription factors in the nucleus.
Microinjection of myristoylated recombinant bovine Calpha and the Asn2 deletion
mutant of it yielded N/C ratios in the same range as encoded native enzymes.
Thus, Asn2 seems to serve as a potential site for modulating electronegativity.
The data indicate that the NH(2)-terminal domain of the PKA C-subunit contributes
to the intracellular distribution of free enzyme, which can be altered by site
specific in vivo deamidation. The model character for other signaling proteins
starting with myrGly-Asn is discussed.
PMID- 10684254
TI - Induction of caveolae in the apical plasma membrane of Madin-Darby canine kidney
cells.
AB - In this paper, we have analyzed the behavior of antibody cross-linked raft
associated proteins on the surface of MDCK cells. We observed that cross-linking
of membrane proteins gave different results depending on whether cross-linking
occurred on the apical or basolateral plasma membrane. Whereas antibody cross
linking induced the formation of large clusters on the basolateral membrane,
resembling those observed on the surface of fibroblasts (Harder, T., P.
Scheiffele, P. Verkade, and K. Simons. 1998. J. Cell Biol. 929-942), only small (
approximately 100 nm) clusters formed on the apical plasma membrane. Cross-linked
apical raft proteins e.g., GPI-anchored placental alkaline phosphatase (PLAP),
influenza hemagglutinin, and gp114 coclustered and were internalized slowly (
approximately 10% after 60 min). Endocytosis occurred through surface
invaginations that corresponded in size to caveolae and were labeled with
caveolin-1 antibodies. Upon cholesterol depletion the internalization of PLAP was
completely inhibited. In contrast, when a non-raft protein, the mutant LDL
receptor LDLR-CT22, was cross-linked, it was excluded from the clusters of raft
proteins and was rapidly internalized via clathrin-coated pits. Since caveolae
are normally present on the basolateral membrane but lacking from the apical
side, our data demonstrate that antibody cross-linking induced the formation of
caveolae, which slowly internalized cross-linked clusters of raft-associated
proteins.
PMID- 10684255
TI - Live Salmonella recruits N-ethylmaleimide-sensitive fusion protein on phagosomal
membrane and promotes fusion with early endosome.
AB - To understand intracellular trafficking modulations by live Salmonella, we
investigated the characteristics of in vitro fusion between endosomes and
phagosomes containing live (LSP) or dead Salmonella (DSP). We observed that
fusion of both DSP and LSP were time, temperature and cytosol dependent.
GTPgammaS and treatment of the phagosomes with Rab-GDI inhibited fusion,
indicating involvement of Rab-GTPases. LSP were rich in rab5, alpha-SNAP, and
NSF, while DSP mainly contained rab7. Fusion of endosomes with DSP was inhibited
by ATP depletion, N-ethylmaleimide (NEM) treatment, and in NEM-sensitive factor
(NSF)-depleted cytosol. In contrast, fusion of endosomes with LSP was not
inhibited by ATP depletion or NEM treatment, and occurred in NSF-depleted
cytosol. However, ATPgammaS inhibited both fusion events. Fusion of NEM-treated
LSP with endosomes was abrogated in NSF- depleted cytosol and was restored by
adding purified NSF, whereas no fusion occurred with NEM-treated DSP, indicating
that NSF recruitment is dependent on continuous signals from live Salmonella.
Binding of NSF with LSP required prior presence of rab5 on the phagosome. We have
also shown that rab5 specifically binds with Sop E, a protein from Salmonella.
Our results indicate that live Salmonella help binding of rab5 on the phagosomes,
possibly activate the SNARE which leads to further recruitment of alpha-SNAP for
subsequent binding with NSF to promote fusion of the LSP with early endosomes and
inhibition of their transport to lysosomes.
PMID- 10684256
TI - Exocytotic insertion of calcium channels constrains compensatory endocytosis to
sites of exocytosis.
AB - Proteins inserted into the cell surface by exocytosis are thought to be retrieved
by compensatory endocytosis, suggesting that retrieval requires granule proteins.
In sea urchin eggs, calcium influx through P-type calcium channels is required
for retrieval, and the large size of sea urchin secretory granules permits the
direct observation of retrieval. Here we demonstrate that retrieval is limited to
sites of prior exocytosis. We tested whether channel distribution can account for
the localization of retrieval at exocytotic sites. We find that P-channels reside
on secretory granules before fertilization, and are translocated to the egg
surface by exocytosis. Our study provides strong evidence that the transitory
insertion of P-type calcium channels in the surface membrane plays an obligatory
role in the mechanism coupling exocytosis and compensatory endocytosis.
PMID- 10684257
TI - A transmembrane segment determines the steady-state localization of an ion
transporting adenosine triphosphatase.
AB - The H,K-adenosine triphosphatase (ATPase) of gastric parietal cells is targeted
to a regulated membrane compartment that fuses with the apical plasma membrane in
response to secretagogue stimulation. Previous work has demonstrated that the
alpha subunit of the H, K-ATPase encodes localization information responsible for
this pump's apical distribution, whereas the beta subunit carries the signal
responsible for the cessation of acid secretion through the retrieval of the pump
from the surface to the regulated intracellular compartment. By analyzing the
sorting behaviors of a number of chimeric pumps composed of complementary
portions of the H, K-ATPase alpha subunit and the highly homologous Na,K-ATPase
alpha subunit, we have identified a portion of the gastric H,K-ATPase, which is
sufficient to redirect the normally basolateral Na,K-ATPase to the apical surface
in transfected epithelial cells. This motif resides within the fourth of the H,K
ATPase alpha subunit's ten predicted transmembrane domains. Although interactions
with glycosphingolipid-rich membrane domains have been proposed to play an
important role in the targeting of several apical membrane proteins, the apically
located chimeras are not found in detergent-insoluble complexes, which are
typically enriched in glycosphingolipids. Furthermore, a chimera incorporating
the Na, K-ATPase alpha subunit fourth transmembrane domain is apically targeted
when both of its flanking sequences derive from H,K-ATPase sequence. These
results provide the identification of a defined apical localization signal in a
polytopic membrane transport protein, and suggest that this signal functions
through conformational interactions between the fourth transmembrane spanning
segment and its surrounding sequence domains.
PMID- 10684258
TI - Exogenous expression of N-cadherin in breast cancer cells induces cell migration,
invasion, and metastasis.
AB - E- and N-cadherin are calcium-dependent cell adhesion molecules that mediate cell
cell adhesion and also modulate cell migration and tumor invasiveness. The loss
of E-cadherin-mediated adhesion has been shown to play an important role in the
transition of epithelial tumors from a benign to an invasive state. However,
recent evidence indicates that another member of the cadherin family, N-cadherin,
is expressed in highly invasive tumor cell lines that lacked E-cadherin
expression. These findings have raised the possibility that N-cadherin
contributes to the invasive phenotype. To determine whether N-cadherin promotes
invasion and metastasis, we transfected a weakly metastatic and E-cadherin
expressing breast cancer cell line, MCF-7, with N-cadherin and analyzed the
effects on cell migration, invasion, and metastasis. Transfected cells expressed
both E- and N-cadherin and exhibited homotypic cell adhesion from both molecules.
In vitro, N-cadherin-expressing cells migrated more efficiently, showed an
increased invasion of Matrigel, and adhered more efficiently to monolayers of
endothelial cells. All cells produced low levels of the matrix metalloproteinase
MMP-9, which was dramatically upregulated by treatment with FGF-2 only in N
cadherin-expressing cells. Migration and invasion of Matrigel were also greatly
enhanced by this treatment. When injected into the mammary fat pad of nude mice,
N-cadherin-expressing cells, but not control MCF-7 cells, metastasized widely to
the liver, pancreas, salivary gland, omentum, lung, lymph nodes, and lumbar
spinal muscle. The expression of both E- and N-cadherin was maintained both in
the primary tumors and metastatic lesions. These results demonstrate that N
cadherin promotes motility, invasion, and metastasis even in the presence of the
normally suppressive E-cadherin. The increase in MMP-9 production by N-cadherin
expressing cells in response to a growth factor may endow them with a greater
ability to penetrate matrix protein barriers, while the increase in their
adherence to endothelium may improve their ability to enter and exit the
vasculature, two properties that may be responsible for metastasis of N-cadherin
expressing cells.
PMID- 10684259
TI - Oncogenic Raf-1 disrupts epithelial tight junctions via downregulation of
occludin.
AB - Occludin is an integral membrane protein of the epithelial cell tight junction
(TJ). Its potential role in coordinating structural and functional events of TJ
formation has been suggested recently. Using a rat salivary gland epithelial cell
line (Pa-4) as a model system, we have demonstrated that occludin not only is a
critical component of functional TJs but also controls the phenotypic changes
associated with epithelium oncogenesis. Transfection of an oncogenic Raf-1 into
Pa-4 cells resulted in a complete loss of TJ function and the acquisition of a
stratified phenotype that lacked cell-cell contact growth control. The expression
of occludin and claudin-1 was downregulated, and the distribution patterns of ZO
1 and E-cadherin were altered. Introduction of the human occludin gene into Raf-1
activated Pa-4 cells resulted in reacquisition of a monolayer phenotype and the
formation of functionally intact TJs. In addition, the presence of exogenous
occludin protein led to a recovery in claudin-1 protein level, relocation of the
zonula occludens 1 protein (ZO-1) to the TJ, and redistribution of E-cadherin to
the lateral membrane. Furthermore, the expression of occludin inhibited anchorage
independent growth of Raf-1-activated Pa-4 cells in soft agarose. Thus, occludin
may act as a pivotal signaling molecule in oncogenic Raf- 1-induced disruption of
TJs, and regulates phenotypic changes associated with epithelial cell
transformation.
PMID- 10684260
TI - The small leucine-rich repeat proteoglycan biglycan binds to alpha-dystroglycan
and is upregulated in dystrophic muscle.
AB - The dystrophin-associated protein complex (DAPC) is necessary for maintaining the
integrity of the muscle cell plasma membrane and may also play a role in
coordinating signaling events at the cell surface. The alpha-/beta-dystroglycan
subcomplex of the DAPC forms a critical link between the cytoskeleton and the
extracellular matrix. A ligand blot overlay assay was used to search for novel
dystroglycan binding partners in postsynaptic membranes from Torpedo electric
organ. An approximately 125-kD dystroglycan-binding polypeptide was purified and
shown by peptide microsequencing to be the Torpedo ortholog of the small leucine
rich repeat chondroitin sulfate proteoglycan biglycan. Biglycan binding to alpha
dystroglycan was confirmed by coimmunoprecipitation with both native and
recombinant alpha-dystroglycan. The biglycan binding site was mapped to the COOH
terminal third of alpha-dystroglycan. Glycosylation of alpha-dystroglycan is not
necessary for this interaction, but binding is dependent upon the chondroitin
sulfate side chains of biglycan. In muscle, biglycan is detected at both synaptic
and nonsynaptic regions. Finally, biglycan expression is elevated in muscle from
the dystrophic mdx mouse. These findings reveal a novel binding partner for alpha
dystroglycan and demonstrate a novel avenue for interaction of the DAPC and the
extracellular matrix. These results also raise the possibility of a role for
biglycan in the pathogenesis, and perhaps the treatment, of muscular dystrophy.
PMID- 10684261
TI - Shedding of syndecan-1 and -4 ectodomains is regulated by multiple signaling
pathways and mediated by a TIMP-3-sensitive metalloproteinase.
AB - The syndecan family of four transmembrane heparan sulfate proteoglycans binds a
variety of soluble and insoluble extracellular effectors. Syndecan extracellular
domains (ectodomains) can be shed intact by proteolytic cleavage of their core
proteins, yielding soluble proteoglycans that retain the binding properties of
their cell surface precursors. Shedding is accelerated by PMA activation of
protein kinase C, and by ligand activation of the thrombin (G-protein-coupled)
and EGF (protein tyrosine kinase) receptors (Subramanian, S.V., M.L. Fitzgerald,
and M. Bernfield. 1997. J. Biol. Chem. 272:14713-14720). Syndecan-1 and -4
ectodomains are found in acute dermal wound fluids, where they regulate growth
factor activity (Kato, M., H. Wang, V. Kainulainen, M.L. Fitzgerald, S.
Ledbetter, D.M. Ornitz, and M. Bernfield. 1998. Nat. Med. 4:691-697) and
proteolytic balance (Kainulainen, V., H. Wang, C. Schick, and M. Bernfield. 1998.
J. Biol. Chem. 273:11563-11569). However, little is known about how syndecan
ectodomain shedding is regulated. To elucidate the mechanisms that regulate
syndecan shedding, we analyzed several features of the process that sheds the
syndecan-1 and -4 ectodomains. We find that shedding accelerated by various
physiologic agents involves activation of distinct intracellular signaling
pathways; and the proteolytic activity responsible for cleavage of syndecan core
proteins, which is associated with the cell surface, can act on unstimulated
adjacent cells, and is specifically inhibited by TIMP-3, a matrix-associated
metalloproteinase inhibitor. In addition, we find that the syndecan-1 core
protein is cleaved on the cell surface at a juxtamembrane site; and the
proteolytic activity responsible for accelerated shedding differs from that
involved in constitutive shedding of the syndecan ectodomains. These results
demonstrate the existence of highly regulated mechanisms that can rapidly convert
syndecans from cell surface receptors or coreceptors to soluble heparan sulfate
proteoglycan effectors. Because the shed ectodomains are found and function in
vivo, regulation of syndecan ectodomain shedding by physiological mediators
indicates that shedding is a response to specific developmental and
pathophysiological cues.
PMID- 10684262
TI - Tissue transglutaminase is an integrin-binding adhesion coreceptor for
fibronectin.
AB - The protein cross-linking enzyme tissue transglutaminase binds in vitro with high
affinity to fibronectin via its 42-kD gelatin-binding domain. Here we report that
cell surface transglutaminase mediates adhesion and spreading of cells on the 42
kD fibronectin fragment, which lacks integrin-binding motifs. Overexpression of
tissue transglutaminase increases its amount on the cell surface, enhances
adhesion and spreading on fibronectin and its 42-kD fragment, enlarges focal
adhesions, and amplifies adhesion-dependent phosphorylation of focal adhesion
kinase. These effects are specific for tissue transglutaminase and are not shared
by its functional homologue, a catalytic subunit of factor XIII. Adhesive
function of tissue transglutaminase does not require its cross-linking activity
but depends on its stable noncovalent association with integrins.
Transglutaminase interacts directly with multiple integrins of beta1 and beta3
subfamilies, but not with beta2 integrins. Complexes of transglutaminase with
integrins are formed inside the cell during biosynthesis and accumulate on the
surface and in focal adhesions. Together our results demonstrate that tissue
transglutaminase mediates the interaction of integrins with fibronectin, thereby
acting as an integrin-associated coreceptor to promote cell adhesion and
spreading.
PMID- 10684263
TI - Nuclear matrix attachment regions of human papillomavirus type 16 repress or
activate the E6 promoter, depending on the physical state of the viral DNA.
AB - Two nuclear matrix attachment regions (MARs) bracket a 550-bp segment of the long
control region (LCR) containing the epithelial cell-specific enhancer and the E6
promoter of human papillomavirus type 16 (HPV-16). One of these MARs is located
in the 5' third of the LCR (5'-LCR-MAR); the other lies within the E6 gene (E6
MAR). To study their function, we linked these MARs in various natural or
artificial permutations to a chimeric gene consisting of the HPV-16 enhancer
promoter segment and a reporter gene. In transient transfections of HeLa cells,
the presence of either of these two MARs strongly represses reporter gene
expression. In contrast to this, but similar to the published behavior of
cellular MARs, reporter gene expression is stimulated strongly by the E6-MAR and
moderately by the 5'-LCR-MAR in stable transfectants of HeLa or C33A cells. To
search for binding sites of soluble nuclear proteins which may be responsible for
repression during transient transfections, we performed electrophoretic mobility
shift assays (EMSAs) of overlapping oligonucleotides that represented all
sequences of these two MARs. Both MARs contain multiple sites for two strongly
binding proteins and weak binding sites for additional factors. The strongest
complex, with at least five binding sites in each MAR, is generated by the CCAAT
displacement factor (CDP)/Cut, as judged by biochemical purification, by EMSAs
with competing oligonucleotides and with anti-CDP/Cut oligonucleotides, and by
mutations. CDP/Cut, a repressor that is down-regulated during differentiation,
apparently represses HPV-16 transcription in undifferentiated epithelials cells
and in HeLa cells, which are rich in CDP/Cut. In analogy to poorly understood
mechanisms acting on cellular MARs, activation after physical linkage to
chromosomal DNA may result from competition between the nuclear matrix and
CDP/Cut. Our observations show that cis-responsive elements that regulate the HPV
16 E6 promoter are tightly clustered over at least 1.3 kb and occur throughout
the E6 gene. HPV-16 MARs are context dependent transcriptional enhancers, and
activated expression of HPV-16 oncogenes dependent on chromosomal integration may
positively select tumorigenic cells during the multistep etiology of cervical
cancer.
PMID- 10684264
TI - Immunization with a modified vaccinia virus expressing simian immunodeficiency
virus (SIV) Gag-Pol primes for an anamnestic Gag-specific cytotoxic T-lymphocyte
response and is associated with reduction of viremia after SIV challenge.
AB - The immunogenicity and protective efficacy of a modified vaccinia virus Ankara
(MVA) recombinant expressing the simian immunodeficiency virus (SIV) Gag-Pol
proteins (MVA-gag-pol) was explored in rhesus monkeys expressing the major
histocompatibility complex (MHC) class I allele, MamuA*01. Macaques received four
sequential intramuscular immunizations with the MVA-gag-pol recombinant virus or
nonrecombinant MVA as a control. Gag-specific cytotoxic T-lymphocyte (CTL)
responses were detected in all MVA-gag-pol-immunized macaques by both functional
assays and flow cytometric analyses of CD8(+) T cells that bound a specific MHC
complex class I-peptide tetramer, with levels peaking after the second
immunization. Following challenge with uncloned SIVsmE660, all macaques became
infected; however, viral load set points were lower in MVA-gag-pol-immunized
macaques than in the MVA-immunized control macaques. MVA-gag-pol-immunized
macaques exhibited a rapid and substantial anamnestic CTL response specific for
the p11C, C-M Gag epitope. The level at which CTL stabilized after resolution of
primary viremia correlated inversely with plasma viral load set point (P = 0.03).
Most importantly, the magnitude of reduction in viremia in the vaccinees was
predicted by the magnitude of the vaccine-elicited CTL response prior to SIV
challenge.
PMID- 10684265
TI - Covalent modification of the transactivator protein IE2-p86 of human
cytomegalovirus by conjugation to the ubiquitin-homologous proteins SUMO-1 and
hSMT3b.
AB - The 86-kDa IE2 protein (IE2-p86) of human cytomegalovirus (HCMV) is a potent
transactivator of viral as well as cellular promoters. Several lines of evidence
indicate that this broad transactivation spectrum is mediated by protein-protein
interactions. To identify novel cellular binding partners, we performed a yeast
two-hybrid screen using a N-terminal deletion mutant of IE2-p86 comprising amino
acids 135 to 579 as a bait. Here, we report the isolation of two ubiquitin
homologous proteins, SUMO-1 and hSMT3b, as well as their conjugating activity
hUBC9 (human ubiquitin-conjugating enzyme 9) as specific interaction partners of
HCMV IE2. The polypeptides SUMO-1 and hSMT3b have previously been shown to be
covalently coupled to a subset of nuclear proteins such as the nuclear domain 10
(ND10) proteins PML and Sp100 in a manner analogous to ubiquitinylation, which we
call SUMOylation. By Western blot analysis, we were able to show that the IE2-p86
protein can be partially converted to a 105-kDa isoform in a dose-dependent
manner after cotransfection of an epitope-tagged SUMO-1. Immunoprecipitation
experiments of the conjugated isoforms using denaturing conditions further
confirmed the covalent coupling of SUMO-1 or hSMT3b to IE2-p86 both after
transient transfection and after lytic infection of human primary fibroblasts.
Moreover, we defined two modification sites within IE2, located in an immediate
vicinity at amino acid positions 175 and 180, which appear to be used
alternatively for coupling. By using a SUMOylation-defective mutant, we showed
that the targeting of IE2-p86 to ND10 occurs independent of this modification.
However, a strong reduction of IE2-mediated transactivation of two viral early
promoters and a heterologous promoter was observed in cotransfection analysis
with the SUMOylation-defective mutant. This suggests a functional relevance of
covalent modification by ubiquitin-homologous proteins for IE2-mediated
transactivation, possibly by providing an additional interaction motif for
cellular cofactors.
PMID- 10684266
TI - Phylogenetic analyses indicate an atypical nurse-to-patient transmission of human
immunodeficiency virus type 1.
AB - A human immunodeficiency virus (HIV)-negative patient with no risk factor
experienced HIV type 1 (HIV-1) primary infection 4 weeks after being hospitalized
for surgery. Among the medical staff, only two night shift nurses were identified
as HIV-1 seropositive. No exposure to blood was evidenced. To test the hypothesis
of a possible nurse-to-patient transmission, phylogenetic analyses were conducted
using two HIV-1 genomic regions (pol reverse transcriptase [RT] and env C2C4),
each compared with reference strains and large local control sets (57 RT and 41
C2C4 local controls). Extensive analyses using multiple methodologies allowed us
to test the robustness of phylogeny inference and to assess transmission
hypotheses. Results allow us to unambiguously exclude one HIV-positive nurse and
strongly suggest the other HIV-positive nurse as the source of infection of the
patient.
PMID- 10684267
TI - Feline immunodeficiency virus Vif localizes to the nucleus.
AB - Monoclonal antibodies prepared against recombinant Vif derived from the 34TF10
strain of feline immunodeficiency virus (FIV) were used to assess the expression
and localization of Vif in virus-infected cells. Analyses by Western blotting and
by immunoprecipitation from cells infected with FIV-34TF10 revealed the presence
of a single 29-kDa species specific for virus-infected cells. Confirmation of
antibody specificity was also performed by specific immunoprecipitation of in
vitro-transcribed and -translated recombinant Vif. Localization experiments were
also performed on virus-infected cells, using different fixation procedures.
Results for methanol fixation protocols similar to those reported for
localization of human immunodeficiency virus (HIV) Vif showed a predominant
cytoplasmic localization for FIV Vif, very similar to localization of HIV type 1
Vif and virtually identical to the localization observed for the Gag antigens of
the virus. However, with milder fixation procedures that used 2% formaldehyde at
4 degrees C, FIV Vif was strongly evident in the nucleus. The localization was
distinct from the nuclear localization noted with Rev and did not involve the
nucleolus. Attempts to show colocalization or coprecipitation of Vif with Gag
antigens were unsuccessful. In addition, Vif was not detected in purified FIV
virions. The results are consistent with the notion that the primary role of Vif
in virus infection initiates in the nucleus.
PMID- 10684268
TI - Evolutionary rate and genetic drift of hepatitis C virus are not correlated with
the host immune response: studies of infected donor-recipient clusters.
AB - Six donor-recipient clusters of hepatitis C virus (HCV)-infected individuals were
studied. For five clusters the period of infection of the donor could be
estimated, and for all six clusters the time of infection of the recipients from
the donor via blood transfusion was also precisely known. Detailed phylogenetic
analyses were carried out to investigate the genomic evolution of the viral
quasispecies within infected individuals in each cluster. The molecular clock
analysis showed that HCV quasispecies within a patient are evolving at the same
rate and that donors that have been infected for longer time tend to have a lower
evolutionary rate. Phylogenetic analysis based on the split decomposition method
revealed different evolutionary patterns in different donor-recipient clusters.
Reactivity of antibody against the first hypervariable region (HVR1) of HCV in
donor and recipient sera was evaluated and correlated to the calculated
evolutionary rate. Results indicate that anti-HVR1 reactivity was related more to
the overall level of humoral immune response of the host than to the HVR1
sequence itself, suggesting that the particular sequence of the HVR1 peptides is
not the determinant of reactivity. Moreover, no correlation was found between the
evolutionary rate or the heterogeneity of the viral quasispecies in the patients
and the strength of the immune response to HVR1 epitopes. Rather, the results
seem to imply that genetic drift is less dependent on immune pressure than on the
rate of evolution and that the genetic drift of HCV is independent of the host
immune pressure.
PMID- 10684269
TI - The Epstein-Barr virus pol catalytic subunit physically interacts with the BBLF4
BSLF1-BBLF2/3 complex.
AB - The Epstein-Barr virus (EBV)-encoded replication proteins that account for the
basic reactions at the replication fork are thought to be the EBV Pol holoenzyme,
consisting of the BALF5 Pol catalytic and the BMRF1 Pol accessory subunits, the
putative helicase-primase complex, comprising the BBLF4, BSLF1, and BBLF2/3
proteins, and the BALF2 single-stranded DNA-binding protein. Immunoprecipitation
analyses using anti-BSLF1 or anti-BBLF2/3 protein-specific antibody with
clarified lysates of B95-8 cells in a viral productive cycle suggested that the
EBV Pol holoenzyme physically interacts with the BBLF4-BSLF1-BBLF2/3 complex to
form a large complex. Although the complex was stable in 500 mM NaCl and 1% NP
40, the BALF5 protein became dissociated in the presence of 0.1% sodium dodecyl
sulfate. Experiments using lysates from insect cells superinfected with
combinations of recombinant baculoviruses capable of expressing each of viral
replication proteins showed that not the BMRF1 Pol accessory subunit but rather
the BALF5 Pol catalytic subunit directly interacts with the BBLF4-BSLF1-BBLF2/3
complex. Furthermore, double infection with pairs of recombinant viruses revealed
that each component of the BBLF4-BSLF1-BBLF2/3 complex makes contact with the
BALF5 Pol catalytic subunit. The interactions of the EBV DNA polymerase with the
EBV putative helicase-primase complex warrant particular attention because they
are thought to coordinate leading- and lagging-strand DNA synthesis at the
replication fork.
PMID- 10684270
TI - Inhibition of CD3/CD28-mediated activation of the MEK/ERK signaling pathway
represses replication of X4 but not R5 human immunodeficiency virus type 1 in
peripheral blood CD4(+) T lymphocytes.
AB - Binding of human immunodeficiency virus type 1 (HIV-1) to CD4 receptors induces
multiple cellular signaling pathways, including the MEK/ERK cascade. While the
interaction of X4 HIV-1 with CXCR4 does not seem to activate this pathway,
viruses using CCR5 for entry efficiently activate MEK/ERK kinases (W. Popik, J.
E. Hesselgesser, and P. M. Pitha, J. Virol. 72:6406-6413, 1998; W. Popik and P.
M. Pitha, Virology 252:210-217, 1998). Since the importance of MEK/ERK in the
initial steps of viral replication is poorly understood, we have examined the
role of MEK/ERK signaling in the CD3- and CD28 (CD3/CD28)-mediated activation of
HIV-1 replication in resting peripheral blood CD4(+) T lymphocytes infected with
X4 or R5 HIV-1. We have found that the MEK/ERK inhibitor U0126 selectively
inhibited CD3/CD28-stimulated replication of X4 HIV-1, while it did not affect
the replication of R5 HIV-1. Inhibition of the CD3/CD28-stimulated MEK/ERK
pathway did not affect the formation of the early proviral transcripts in cells
infected with either X4 or R5 HIV-1, indicating that virus reverse transcription
is not affected in the absence of MEK/ERK signaling. In contrast, the levels of
nuclear provirus in cells infected with X4 HIV-1, detected by the formation of
circular proviral DNA, was significantly lower in cells stimulated in the
presence of MEK/ERK inhibitor than in the absence of the inhibitor. However, in
cells infected with R5 HIV-1, the inhibition of the MEK/ERK pathway did not
affect nuclear localization of the proviral DNA. These data suggest that the
nuclear import of X4, but not R5, HIV-1 is dependent on a CD3/CD28-stimulated
MEK/ERK pathway.
PMID- 10684271
TI - Efficient gene transfer into human CD34(+) cells by a retargeted adenovirus
vector.
AB - Efficient infection with adenovirus (Ad) vectors based on serotype 5 (Ad5)
requires the presence of coxsackievirus-adenovirus receptors (CAR) and alpha(v)
integrins on cells. The paucity of these cellular receptors is thought to be a
limiting factor for Ad gene transfer into hematopoietic stem cells. In a
systematic approach, we screened different Ad serotypes for interaction with
noncycling human CD34(+) cells and K562 cells on the level of virus attachment,
internalization, and replication. From these studies, serotype 35 emerged as the
variant with the highest tropism for CD34(+) cells. A chimeric vector
(Ad5GFP/F35) was generated which contained the short-shafted Ad35 fiber
incorporated into an Ad5 capsid. This substitution was sufficient to transplant
all infection properties from Ad35 to the chimeric vector. The retargeted,
chimeric vector attached to a receptor different from CAR and entered cells by an
alpha(v) integrin-independent pathway. In transduction studies, Ad5GFP/F35
expressed green fluorescent protein (GFP) in 54% of CD34(+) cells. In comparison,
the standard Ad5GFP vector conferred GFP expression to only 25% of CD34(+) cells.
Importantly, Ad5GFP transduction, but not Ad5GFP/F35, was restricted to a
specific subset of CD34(+) cells expressing alpha(v) integrins. The actual
transduction efficiency was even higher than 50% because Ad5GFP/F35 viral genomes
were found in GFP-negative CD34(+) cell fractions, indicating that the
cytomegalovirus promoter used for transgene expression was not active in all
transduced cells. The chimeric vector allowed for gene transfer into a broader
spectrum of CD34(+) cells, including subsets with potential stem cell capacity.
Fifty-five percent of CD34(+) c-Kit(+) cells expressed GFP after infection with
Ad5GFP/F35, whereas only 13% of CD34(+) c-Kit(+) cells were GFP positive after
infection with Ad5GFP. These findings represent the basis for studies aimed
toward stable gene transfer into hematopoietic stem cells.
PMID- 10684272
TI - Containment of simian immunodeficiency virus infection: cellular immune responses
and protection from rechallenge following transient postinoculation
antiretroviral treatment.
AB - To better understand the viral and host factors involved in the establishment of
persistent productive infection by primate lentiviruses, we varied the time of
initiation and duration of postinoculation antiretroviral treatment with
tenofovir (9-[2-(R)-(phosphonomethoxy)propyl]adenine) while performing intensive
virologic and immunologic monitoring in rhesus macaques, inoculated intravenously
with simian immunodeficiency virus SIVsmE660. Postinoculation treatment did not
block the initial infection, but we identified treatment regimens that prevented
the establishment of persistent productive infection, as judged by the absence of
measurable plasma viremia following drug discontinuation. While immune responses
were heterogeneous, animals in which treatment resulted in prevention of
persistent productive infection showed a higher frequency and higher levels of
SIV-specific lymphocyte proliferative responses during the treatment period
compared to control animals, despite the absence of either detectable plasma
viremia or seroconversion. Animals protected from the initial establishment of
persistent productive infection were also relatively or completely protected from
subsequent homologous rechallenge. Even postinoculation treatment regimens that
did not prevent establishment of persistent infection resulted in downmodulation
of the level of plasma viremia following treatment cessation, compared to the
viremia seen in untreated control animals, animals treated with regimens known to
be ineffective, or the cumulative experience with the natural history of plasma
viremia following infection with SIVsmE660. The results suggest that the host may
be able to effectively control SIV infection if the initial exposure occurs under
favorable conditions of low viral burden and in the absence of ongoing high level
cytopathic infection of responding cells. These findings may be particularly
important in relation to prospects for control of primate lentiviruses in the
settings of both prophylactic and therapeutic vaccination for prevention of AIDS.
PMID- 10684273
TI - Partial rescue of the Vif-negative phenotype of mutant human immunodeficiency
virus type 1 strains from nonpermissive cells by intravirion reverse
transcription.
AB - Virion infectivity factor (Vif) is a protein encoded by human immunodeficiency
virus type I (HIV-1) and is essential for viral replication. It appears that Vif
functions in the virus-producing cells and affects viral assembly. Viruses with
defects in the vif gene (vif-) generated from the "nonpermissive cells" are not
able to complete reverse transcription. In previous studies, it was demonstrated
that defects in the vif gene also affect endogenous reverse transcription (ERT)
when mild detergents were utilized to permeabilize the viral envelope. In this
report, we demonstrate that defects in the vif gene have much less of an effect
on ERT if detergent is not used. When ERT was driven by addition of
deoxyribonucleoside triphosphates (dNTPs) at high concentrations, certain levels
of plus-strand viral DNA could also be achieved. Interestingly, if vif- viruses,
generated from nonpermissive cells and harboring large quantities of viral DNA
generated by ERT, were allowed to infect permissive cells, they could partially
bypass the block at intracellular reverse transcription, through which vif-
viruses without dNTP treatment could not pass. Consequently, viral infectivity
can be partially rescued from the vif- phenotype. Based on our observations, we
suggest that vif defects may cause the reverse transcription complex (RT complex)
to become sensitive to mild detergent treatments within HIV-1 virions and become
unstable in the target cells, such that the process of reverse transcription
cannot be efficiently supported. Further dissection of RT complexes of vif-
viruses may be key to uncovering the molecular mechanism(s) of Vif in HIV-1
pathogenesis.
PMID- 10684274
TI - Rinderpest viruses lacking the C and V proteins show specific defects in growth
and transcription of viral RNAs.
AB - Rinderpest virus is a morbillivirus and the causative agent of an important
disease of cattle and wild bovids. The P genes of all morbilliviruses give rise
to two proteins in addition to the P protein itself: use of an alternate start
translation site, in a second open reading frame, gives rise to the C protein,
while cotranscriptional insertion of an extra base gives rise to the V protein, a
fusion of the amino-terminal half of P to a short, highly conserved, cysteine
rich zinc binding domain. Little is known about the function of either of these
two proteins in the rinderpest virus life cycle. We have constructed recombinant
rinderpest viruses in which the expression of these proteins has been suppressed,
individually and together, and studied the replication of these viruses in tissue
culture. We show that the absence of the V protein has little effect on the
replication rate of the virus but does lead to an increase in synthesis of genome
and antigenome RNAs and a change in cytopathic effect to a more syncytium-forming
phenotype. Virus that does not express the C protein, on the other hand, is
clearly defective in growth in all cell lines tested, and this defect appears to
be related to a decreased transcription of mRNA from viral genes. The phenotypes
of both individual mutant virus types are both expressed in the double mutant
expressing neither V nor C.
PMID- 10684275
TI - Infection of primary human monocytes by Epstein-Barr virus.
AB - Previous studies have reported that infection of monocytes by viruses such as
cytomegalovirus and human immunodeficiency virus weakens host natural immunity.
In the present study, we demonstrated the capability of Epstein-Barr virus (EBV)
to infect and replicate in freshly isolated human monocytes. Using electron
microscopy analysis, we observed the presence of EBV virions in the cytoplasm and
nuclei of approximately 20% of monocytes. This was confirmed by Southern blot
analysis of EBV genomic DNA sequences in isolated nuclei from monocytes.
Infection of monocytes by EBV leads to the activation of the replicative cycle.
This was supported by the detection of immediate-early lytic mRNA BZLF-1
transcripts, and by the presence of two early lytic transcripts (BALF-2, which
appears to function in DNA replication, and BHRF-1, also associated with the
replicative cycle). The late lytic BcLF-1 transcripts, which code for the major
nucleocapsid protein, were also detected, as well as EBNA-1 transcripts. However,
attempts to detect EBNA-2 transcripts have yielded negative results. Viral
replication was also confirmed by the release of newly synthesized infectious
viral particles in supernatants of EBV-infected monocytes. EBV-infected monocytes
were found to have significantly reduced phagocytic activity, as evaluated by the
quantification of ingested carboxylated fluoresceinated latex beads. Taken
together, our results suggest that EBV infection of monocytes and alteration of
their biological functions might represent a new mechanism to disrupt the immune
response and promote viral propagation during the early stages of infection.
PMID- 10684276
TI - Immune responses following neonatal DNA vaccination are long-lived, abundant, and
qualitatively similar to those induced by conventional immunization.
AB - Virus infections are devastating to neonates, and the induction of active
antiviral immunity in this age group is an important goal. Here, we show that a
single neonatal DNA vaccination induces cellular and humoral immune responses
which are maintained for a significant part of the animal's life span. We employ
a sensitive technique which permits the first demonstration and quantitation,
directly ex vivo, of virus-specific CD8(+) T cells induced by DNA immunization.
One year postvaccination, antigen-specific CD8(+) T cells were readily detectable
and constituted 0.5 to 1% of all CD8(+) T cells. By several criteria-including
cytokine production, perforin content, development of lytic ability, and
protective capacity-DNA vaccine-induced CD8(+) memory T cells were
indistinguishable from memory cells induced by immunization with a conventional
(live-virus) vaccine. Analyses of long-term humoral immune responses revealed
that, in contrast to the strong immunoglobulin G2a (IgG2a) skewing of the humoral
response seen after conventional vaccination, IgG1 and IgG2a levels were similar
in DNA-vaccinated neonatal and adult animals, indicating a balanced T helper
response. Collectively, these results show that a single DNA vaccination within
hours or days of birth can induce long-lasting CD8(+) T- and B-cell responses;
there is no need for secondary immunization (boosting). Furthermore, the observed
immune responses induced in neonates and in adults are indistinguishable by
several criteria, including protection against virus challenge.
PMID- 10684277
TI - Increased expression and immunogenicity of sequence-modified human
immunodeficiency virus type 1 gag gene.
AB - A major challenge for the next generation of human immunodeficiency virus (HIV)
vaccines is the induction of potent, broad, and durable cellular immune
responses. The structural protein Gag is highly conserved among the HIV type 1
(HIV-1) gene products and is believed to be an important target for the host cell
mediated immune control of the virus during natural infection. Expression of Gag
proteins for vaccines has been hampered by the fact that its expression is
dependent on the HIV Rev protein and the Rev-responsive element, the latter
located on the env transcript. Moreover, the HIV genome employs suboptimal codon
usage, which further contributes to the low expression efficiency of viral
proteins. In order to achieve high-level Rev-independent expression of the Gag
protein, the sequences encoding HIV-1(SF2) p55(Gag) were modified extensively.
First, the viral codons were changed to conform to the codon usage of highly
expressed human genes, and second, the residual inhibitory sequences were
removed. The resulting modified gag gene showed increases in p55(Gag) protein
expression to levels that ranged from 322- to 966-fold greater than that for the
native gene after transient expression of 293 cells. Additional constructs that
contained the modified gag in combination with modified protease coding sequences
were made, and these showed high-level Rev-independent expression of p55(Gag) and
its cleavage products. Density gradient analysis and electron microscopy further
demonstrated that the modified gag and gag protease genes efficiently expressed
particles with the density and morphology expected for HIV virus-like particles.
Mice immunized with DNA plasmids containing the modified gag showed Gag-specific
antibody and CD8(+) cytotoxic T-lymphocyte (CTL) responses that were inducible at
doses of input DNA 100-fold lower than those associated with plasmids containing
the native gag gene. Most importantly, four of four rhesus monkeys that received
two or three immunizations with modified gag plasmid DNA demonstrated substantial
Gag-specific CTL responses. These results highlight the useful application of
modified gag expression cassettes for increasing the potency of DNA and other
gene delivery vaccine approaches against HIV.
PMID- 10684278
TI - Genetic studies with the fission yeast Schizosaccharomyces pombe suggest
involvement of wee1, ppa2, and rad24 in induction of cell cycle arrest by human
immunodeficiency virus type 1 Vpr.
AB - Accessory protein Vpr of human immunodeficiency virus type 1 (HIV-1) arrests cell
cycling at G(2)/M phase in human and simian cells. Recently, it has been shown
that Vpr also causes cell cycle arrest in the fission yeast Schizosaccharomyces
pombe, which shares the cell cycle regulatory mechanisms with higher eukaryotes
including humans. In this study, in order to identify host cellular factors
involved in Vpr-induced cell cycle arrest, the ability of Vpr to cause elongated
cellular morphology (cdc phenotype) typical of G(2)/M cell cycle arrest in wild
type and various mutant strains of S. pombe was examined. Our results indicated
that Vpr caused the cdc phenotype in wild-type S. pombe as well as in strains
carrying mutations, such as the cdc2-3w, Deltacdc25, rad1-1, Deltachk1,
Deltamik1, and Deltappa1 strains. However, other mutants, such as the cdc2-1w,
Deltawee1, Deltappa2, and Deltarad24 strains, failed to show a distinct cdc
phenotype in response to Vpr expression. Results of these genetic studies
suggested that Wee1, Ppa2, and Rad24 might be required for induction of cell
cycle arrest by HIV-1 Vpr. Cell proliferation was inhibited by Vpr expression in
all of the strains examined including the ones that did not show the cdc
phenotype. The results supported the previously suggested possibility that Vpr
affects the cell cycle and cell proliferation through different pathways.
PMID- 10684279
TI - Mapping in solution shows the peach latent mosaic viroid to possess a new
pseudoknot in a complex, branched secondary structure.
AB - We have investigated the secondary structure of peach latent mosaic viroid
(PLMVd) in solution, and we present here the first description of the structure
of a branched viroid in solution. Different PLMVd transcripts of plus polarity
were produced by using the circularly permuted RNA method and the exploitation of
RNA internal secondary structure to position the 5' and 3' termini and studied by
nuclease mapping and binding shift assays using DNA and RNA oligonucleotides. We
show that PLMVd folds into a complex, branched secondary structure. In general,
this structure is similar to that reported previously, which was based on
sequence comparison and computer modelling. The structural microheterogeneity is
apparently limited to only some small domains. More importantly, this structure
includes a novel pseudoknot that is conserved in all PLMVd isolates and seems to
allow folding into a very compact form. This pseudoknot is also found in
chrysanthemum chlorotic mottle viroid, suggesting that it is a unique feature of
the viroid members of the PLMVd subgroup.
PMID- 10684280
TI - Human T-cell leukemia virus type 2 tax mutants that selectively abrogate NFkappaB
or CREB/ATF activation fail to transform primary human T cells.
AB - Human T-cell leukemia virus (HTLV) Tax protein has been implicated in the HTLV
oncogenic process, primarily due to its pleiotropic effects on cellular genes
involved in growth regulation and cell cycle control. To date, several approaches
attempting to correlate Tax activation of the CREB/activating transcription
factor (ATF) or NFkappaB/Rel transcriptional activation pathway to cellular
transformation have yielded conflicting results. In this study, we use a unique
HTLV-2 provirus (HTLV(c-enh)) that replicates by a Tax-independent mechanism to
directly assess the role of Tax transactivation in HTLV-mediated T-lymphocyte
transformation. A panel of well-characterized tax-2 mutations is utilized to
correlate the respective roles of the CREB/ATF or NFkappaB/Rel signaling pathway.
Our results demonstrate that viruses expressing tax-2 mutations that selectively
abrogate NFkappaB/Rel or CREB/ATF activation display distinct phenotypes but
ultimately fail to transform primary human T lymphocytes. One conclusion
consistent with our results is that the activation of NFkappaB/Rel provides a
critical proliferative signal early in the cellular transformation process,
whereas CREB/ATF activation is required to promote the fully transformed state.
However, complete understanding will require correlation of Tax domains important
in cellular transformation to those Tax domains important in the modulation of
gene transcription, cell cycle control, induction of DNA damage, and other
undefined activities.
PMID- 10684281
TI - Adaptive mutations in Sindbis virus E2 and Ross River virus E1 that allow
efficient budding of chimeric viruses.
AB - Alphavirus glycoproteins E2 and E1 form a heterodimer that is required for virus
assembly. We have studied adaptive mutations in E2 of Sindbis virus (SIN) and E1
of Ross River virus (RR) that allow these two glycoproteins to interact more
efficiently in a chimeric virus that has SIN E2 but RR E1. These mutations
include K129E, K131E, and V237F in SIN E2 and S310F and C433R in RR E1. Although
RR E1 and SIN E2 will form a chimeric heterodimer, the chimeric virus is almost
nonviable, producing about 10(-7) as much virus as SIN at 24 h and 10(-5) as much
after 48 h. Chimeras containing one adaptive change produced 3 to 20 times more
virus than did the parental chimera, whereas chimeras with two changes produced
10 to 100 times more virus and chimeras containing three mutations produced
yields that were 180 to 250 times better. None of the mutations had significant
effects upon the parental wild-type viruses, however. Passage of the triple
variants eight or nine times resulted in variants that produced virus rapidly and
were capable of producing >10(8) PFU/ml of culture fluid within 24 h. These
further-adapted variants possessed one or two additional mutations, including E2
V116K, E2-S110N, or E1-T65S. The RR E1-C433R mutation was studied in more detail.
This Cys is located in the putative transmembrane domain of E1 and was shown to
be palmitoylated. Mutation to Arg-433 resulted in loss of palmitoylation of E1.
The positively charged arginine residue within the putative transmembrane domain
of E1 would be expected to alter the conformation of this domain. These results
suggest that interactions within the transmembrane region are important for the
assembly of the E1/E2 heterodimer, as are regions of the ectodomains possibly
identified by the locations of adaptive mutations in these regions. Further, the
finding that four or five changes in the chimera allow virus production that
approaches the levels seen with the parental SIN and exceeds that of the parental
RR illustrates that the structure and function of SIN and RR E1s have been
conserved during the 50% divergence in sequence that has occurred.
PMID- 10684282
TI - Human beta interferon scaffold attachment region inhibits de novo methylation and
confers long-term, copy number-dependent expression to a retroviral vector.
AB - Moloney murine leukemia virus-based retroviral vector expression is gradually
lost during prolonged in vitro culture of CEMSS T cells. However, when the human
beta interferon scaffold attachment region (IFN-SAR) was inserted into the vector
immediately upstream of the 3' long terminal repeat (LTR), expression was
maintained for the length of the study (4 months). Clonal analysis of the
retrovirus vector-infected CEMSS cells showed that SAR-containing retroviral
vector expression levels were positively correlated with the proviral copy
numbers (P < 0.0001), while there was no correlation between the proviral copy
numbers and expression levels in control vector-infected clones. Thirty-three
percent of the CEMSS cell clones infected with the control vector showed evidence
of partial or complete methylation in the 5' LTR region. In sharp contrast, we
detected no methylation in the clones infected with the SAR-containing vector. To
demonstrate a direct inhibitory effect of methylation on retroviral vector
expression, we have transfected 293 cells with in vitro-methylated proviral DNA.
In transiently transfected cells, expression of methylated LTR was reduced but
not completely inhibited, irrespective of the presence of the IFN-SAR sequence.
In stably transfected cells, however, methylation completely abolished expression
of the control vector but not of the SAR-containing vector. Furthermore, the
expression of the SAR-containing vector was stable over time, indicating the
ability of the SAR sequence to alleviate methylation-mediated transcriptional
repression of a vector. This study extends our understanding of the mechanisms of
retroviral vector inactivation by methylation and provides insight into a
functional role for the SAR elements.
PMID- 10684283
TI - Repression of the integrated papillomavirus E6/E7 promoter is required for growth
suppression of cervical cancer cells.
AB - The human papillomavirus (HPV) E2 protein is an important regulator of viral E6
and E7 gene expression. E2 can repress the viral promoter for E6 and E7
expression as well as block progression of the cell cycle in cancer cells
harboring the DNA of "high-risk" HPV types. Although the phenomenon of E2
mediated growth arrest of HeLa cells and other HPV-positive cancer cells has been
well documented, the specific mechanism by which E2 affects cellular
proliferation has not yet been elucidated. Here, we show that bovine
papillomavirus (BPV) E2-induced growth arrest of HeLa cells requires the
repression of the E6 and E7 promoter. This repression is specific for E2TA and
not E2TR, a BPV E2 variant that lacks the N-terminal transactivation domain. We
demonstrate that expression of HPV16 E6 and E7 from a heterologous promoter that
is not regulated by E2 rescues HeLa cells from E2-mediated growth arrest. Our
data indicate that the pathway of E2-mediated growth arrest of HeLa cells
requires repression of E6 and E7 expression through an activity specified by the
transactivation domain of E2TA.
PMID- 10684284
TI - Interaction of the adenovirus IVa2 protein with viral packaging sequences.
AB - We have demonstrated previously that the adenovirus L1 52/55-kDa protein binds to
the viral IVa2 protein in infected cells. The significance of this interaction
was unclear, however, based on the known functions of these two proteins: the
52/55-kDa protein is required for viral DNA packaging, while the IVa2 protein is
a transactivator of the major late promoter (MLP). In this report, we have
attempted to elucidate a role for each of the two proteins in the other's known
function. There is no apparent effect of the 52/55-kDa protein on the interaction
of the IVa2 protein with the MLP. Surprisingly, however, we found that the IVa2
protein can interact with the adenoviral packaging signal and that this
interaction involves DNA sequences that have previously been demonstrated to be
required for packaging.
PMID- 10684285
TI - Replication of lengthened Moloney murine leukemia virus genomes is impaired at
multiple stages.
AB - It has been assumed that RNA packaging constraints limit the size of retroviral
genomes. This notion of a retroviral "headful" was tested by examining the
ability of Moloney murine leukemia virus genomes lengthened by 4, 8, or 11 kb to
participate in a single replication cycle. Overall, replication of these
lengthened genomes was 5- to 10-fold less efficient than that of native-length
genomes. When RNA expression and virion formation, RNA packaging, and early
stages of replication were compared, long genomes were found to complete each
step less efficiently than did normal-length genomes. To test whether short RNAs
might facilitate the packaging of lengthy RNAs by heterodimerization, some
experiments involved coexpression of a short packageable RNA. However,
enhancement of neither long vector RNA packaging nor long vector DNA synthesis
was observed in the presence of the short RNA. Most of the proviruses templated
by 12 and 16 kb vectors appeared to be full length. Most products of a 19. 2-kb
vector contained deletions, but some integrated proviruses were around twice the
native genome length. These results demonstrate that lengthy retroviral genomes
can be packaged and that genome length is not strictly limited at any individual
replication step. These observations also suggest that the lengthy read-through
RNAs postulated to be intermediates in retroviral transduction can be packaged
directly without further processing.
PMID- 10684286
TI - Jembrana disease virus Tat can regulate human immunodeficiency virus (HIV) long
terminal repeat-directed gene expression and can substitute for HIV Tat in viral
replication.
AB - Jembrana disease virus (JDV) is a bovine lentivirus genetically similar to bovine
immunodeficiency virus; it causes an acute and sometimes fatal disease in
infected animals. This virus carries a very potent Tat that can strongly activate
not only its own long terminal repeat (LTR) but also the human immunodeficiency
virus (HIV) LTR. In contrast, HIV Tat cannot reciprocally activate the JDV LTR
(H. Chen, G. E. Wilcox, G. Kertayadnya, and C. Wood, J. Virol. 73:658-666, 1999).
This indicates that in transactivation JDV Tat may utilize a mechanism similar to
but not the same as that of the HIV Tat. To further study the similarity of JDV
and HIV tat in transactivation, we first tested the responses of a series of HIV
LTR mutants to the JDV Tat. Cross-transactivation of HIV LTR by JDV Tat was
impaired by mutations that disrupted the HIV type 1 transactivation response
element (TAR) RNA stem-loop structure. Our results demonstrated that JDV Tat,
like HIV Tat, transactivated the HIV LTR at least partially in a TAR-dependent
manner. However, the sequence in the loop region of TAR was not as critical for
the function of JDV Tat as it was for HIV Tat. The competitive inhibition of Tat
induced transactivation by the truncated JDV or HIV Tat, which consisted only of
the activation domain, suggested that similar cellular factors were involved in
both JDV and HIV Tat-induced transactivation. Based on the one-round transfection
assay with HIV tat mutant proviruses, the cotransfected JDV tat plasmid can
functionally complement the HIV tat defect. To further characterize the effect of
JDV Tat on HIV, a stable chimeric HIV carrying the JDV tat gene was generated.
This chimeric HIV replicated in a T-cell line, C8166, and in peripheral blood
mononuclear cells, which suggested that JDV Tat can functionally substitute for
HIV Tat. Further characterization of this chimeric virus will help to elucidate
how JDV Tat functions and to explain the differences between HIV and JDV Tat
transactivation.
PMID- 10684287
TI - Role of hemagglutinin surface density in the initial stages of influenza virus
fusion: lack of evidence for cooperativity.
AB - Membrane fusion mediated by influenza virus hemagglutinin (HA) is believed to
proceed via the cooperative action of multiple HA trimers. To determine the
minimal number of HA trimers required to trigger fusion, and to assess the
importance of cooperativity between these HA trimers, we have generated virosomes
containing coreconstituted HAs derived from two strains of virus with different
pH dependencies for fusion, X-47 (optimal fusion at pH 5.1; threshold at pH 5.6)
and A/Shangdong (optimal fusion at pH 5.6; threshold at pH 6.0), and measured
fusion of these virosomes with erythrocyte ghosts by a fluorescence lipid mixing
assay. Virosomes with different X-47-to-A/Shangdong HA ratios, at a constant HA
to-lipid ratio, showed comparable ghost-binding activities, and the low-pH
induced conformational change of A/Shangdong HA did not affect the fusion
activity of X-47 HA. The initial rate of fusion of these virosomes at pH 5.7
increased directly proportional to the surface density of A/Shangdong HA, and a
single A/Shangdong trimer per virosome appeared to suffice to induce fusion. The
reciprocal of the lag time before the onset of fusion was directly proportional
to the surface density of fusion-competent HA. These results support the notion
that there is no cooperativity between HA trimers during influenza virus fusion.
PMID- 10684288
TI - Activation of lymphocyte signaling by the R1 protein of rhesus monkey
rhadinovirus.
AB - Rhesus monkey rhadinovirus (RRV) is a gamma-2 herpesvirus that exhibits a
considerable degree of similarity to the human Kaposi's sarcoma-associated
herpesvirus (KSHV). The R1 protein of RRV is distantly related to the K1 protein
of KSHV, and R1, like K1, can contribute to cell growth transformation. In this
study we analyzed the ability of the cytoplasmic tail of R1 to function as a
signal transducer. The cytoplasmic domain of the R1 protein contains several
tyrosine residues whose phosphorylation is induced in cells expressing Syk
kinase. Expression of a CD8 chimera protein containing the extracellular and
transmembrane domains of CD8 fused to the cytoplasmic domain of R1 mobilized
intracellular calcium and induced cellular tyrosine phosphorylation in B cells
upon stimulation with anti-CD8 antibody. None of the CD8-R1 cytoplasmic deletion
mutants tested were able to mobilize intracellular calcium or to induce tyrosine
phosphorylation to a significant extent upon addition of anti-CD8 antibody.
Expression of wild-type R1 protein activated nuclear factor of activated T
lymphocytes (NFAT) eightfold in B cells in the absence of antibody stimulation;
expression of the CD8-R1C chimera strongly induced NFAT activity (60-fold) but
only upon the addition of anti-CD8 antibody. We conclude that the cytoplasmic
domain of R1 is capable of transducing signals that elicit B-lymphocyte
activation events. The signal-inducing properties of R1 appear to be similar to
those of K1 but differ in that the required sequences are distributed over a much
longer stretch of the cytoplasmic domain (>150 amino acids). In addition, the
induction of calcium mobilization was considerably longer in duration and
stronger with R1 than with K1.
PMID- 10684289
TI - Regulation of adenovirus membrane penetration by the cytoplasmic tail of integrin
beta5.
AB - Adenovirus (Ad) cell entry involves sequential interactions with host cell
receptors that mediate attachment (CAR), internalization (alphavbeta3 and
alphavbeta5), and penetration (alphavbeta5) of the endosomal membrane. These
events allow the virus to deliver its genome to the nucleus. While integrins
alphavbeta3 and alphavbeta5 both promote Ad internalization into cells, integrin
alphavbeta5 selectively facilitates Ad-mediated membrane permeabilization and
endosome rupture. In the experiments reported herein, we demonstrate that the
intracellular domain of the integrin beta5 subunit specifically regulates Ad
mediated membrane permeabilization and gene delivery. CS-1 melanoma cells
expressing a truncated integrin beta5 or a chimeric (beta5-beta3) cytoplasmic
tail (CT) supported normal levels of Ad endocytosis but had reduced Ad-mediated
gene delivery and membrane permeabilization relative to cells expressing a wild
type integrin beta5. Thin-section electron microscopy revealed that virion
particles were capable of being endocytosed into cells expressing a truncated
beta5CT, but they failed to escape cytoplasmic vesicles and translocate to the
nucleus. Site-specific mutagenesis studies suggest that a C-terminal TVD motif in
the beta5CT plays a major role in Ad membrane penetration.
PMID- 10684290
TI - Comparative efficacy of recombinant modified vaccinia virus Ankara expressing
simian immunodeficiency virus (SIV) Gag-Pol and/or Env in macaques challenged
with pathogenic SIV.
AB - Prior studies demonstrated that immunization of macaques with simian
immunodeficiency virus (SIV) Gag-Pol and Env recombinants of the attenuated
poxvirus modified vaccinia virus Ankara (MVA) provided protection from high
levels of viremia and AIDS following challenge with a pathogenic strain of SIV
(V. M. Hirsch et al., J. Virol. 70:3741-3752, 1996). This MVA-SIV recombinant
expressed relatively low levels of the Gag-Pol portion of the vaccine. To
optimize protection, second-generation recombinant MVAs that expressed high
levels of either Gag-Pol (MVA-gag-pol) or Env (MVA-env), alone or in combination
(MVA-gag-pol-env), were generated. A cohort of 24 macaques was immunized with
recombinant or nonrecombinant MVA (four groups of six animals) and was challenged
with 50 times the dose at which 50% of macaques are infected with uncloned
pathogenic SIVsmE660. Although all animals became infected postchallenge, plasma
viremia was significantly reduced in animals that received the MVA-SIV
recombinant vaccines as compared with animals that received nonrecombinant MVA (P
= 0.0011 by repeated-measures analysis of variance). The differences in the
degree of virus suppression achieved by the three MVA-SIV vaccines were not
significant. Most importantly, the reduction in levels of viremia resulted in a
significant increase in median (P < 0.05 by Student's t test) and cumulative (P =
0.010 by log rank test) survival. These results suggest that recombinant MVA has
considerable potential as a vaccine vector for human AIDS.
PMID- 10684291
TI - A novel mechanism of resistance to mouse mammary tumor virus infection.
AB - Exogenous mouse mammary tumor virus (MMTV) is carried from the gut of suckling
pups to the mammary glands by lymphocytes and induces mammary gland tumors. MMTV
induced tumor incidence in inbred mice of different strains ranges from 0 to as
high as 100%. For example, mice of the C3H/HeN strain are highly susceptible,
whereas mice of the I/LnJ strain are highly resistant. Of the different factors
that together determine the susceptibility of mice to development of MMTV-induced
mammary tumors, genetic elements play a major role, although very few genes that
determine a susceptibility-resistance phenotype have been identified so far. Our
data indicate that MMTV fails to infect mammary glands in I/LnJ mice foster
nursed on viremic C3H/HeN females, even though the I/LnJ mammary tissue is not
refractory to MMTV infection. Lymphocytes from fostered I/LnJ mice contained
integrated MMTV proviruses and shed virus but failed to establish infection in
the mammary glands of susceptible syngeneic (I x C3H.JK)F(1) females. Based on
the susceptible-resistant phenotype distribution in N(2) females, both MMTV
mammary gland infection and mammary gland tumor development in I/LnJ mice are
controlled by a single locus.
PMID- 10684292
TI - Functional characterization of the human immunodeficiency virus type 1 genome by
genetic footprinting.
AB - We present a detailed and quantitative analysis of the functional characteristics
of the 1,000-nucleotide segment at the 5' end of the human immunodeficiency virus
type 1 (HIV-1) RNA genome. This segment of the viral genome contains several
important cis-acting sequences, including the TAR, polyadenylation, viral att
site, minus-strand primer-binding site, and 5' splice donor sequences, as well as
coding sequences for the matrix protein and the N-terminal half of the capsid
protein. The genetic footprinting technique was used to determine quantitatively
the abilities of 134 independent insertion mutations to (i) make stable viral
RNA, (ii) assemble and release viral RNA-containing viral particles, and (iii)
enter host cells, complete reverse transcription, enter the nuclei of host cells,
and generate proviruses in the host genome by integration. All of the mutants
were constructed and analyzed en masse, greatly decreasing the labor typically
involved in mutagenesis studies. The results confirmed the presence of several
previously known functional features in this region of the HIV genome and
provided evidence for several novel features, including newly identified cis
acting sequences that appeared to contribute to (i) the formation of stable viral
transcripts, (ii) viral RNA packaging, and (iii) an early step in viral
replication. The results also pointed to an unanticipated trans-acting role for
the N-terminal portion of matrix in the formation of stable viral RNA
transcripts. Finally, in contrast to previous reports, the results of this study
suggested that detrimental mutations in the matrix and capsid proteins
principally interfered with viral assembly.
PMID- 10684293
TI - The kinetics of VP5 mRNA expression is not critical for viral replication in
cultured cells.
AB - We generated recombinant viruses in which the kinetics of expression of the leaky
late VP5 mRNA was altered. We then analyzed the effect of such alterations on
viral replication in cultured cells. The VP5 promoter and leader sequences from
positions -36 to +20, containing the TATA box and an initiator element, were
deleted and replaced with a strong early (dUTPase), an equal-strength leaky-late
(VP16), or a strict-late (U(L)38) promoter. We found that recombinant viruses
containing the dUTPase promoter inserted in the VP5 locus expressed VP5-encoding
mRNA with early kinetics, while virus with the U(L)38 promoter inserted expressed
such mRNA with strict-late kinetics. Further, in spite of differences in its
functional architecture, the VP16 promoter fully substituted for the VP5
promoter. Western blot analysis demonstrated that the amounts of VP5 capsid
protein produced by the recombinant viruses differed somewhat; however, on
complementing C32 and noncomplementing Vero cells, such viruses replicated to
titers equivalent to those of the rescued wild-type virus controls. Multistep
virus growth in mouse embryo fibroblasts, rabbit skin cells, and Vero cells also
demonstrated equivalent replication efficiencies for both recombinant and wild
type viruses. Further, recombinant viruses did not show any impairment in their
ability to replicate on serum-starved or quiescent human lung fibroblasts. We
conclude that the kinetics of the essential VP5 mRNA expression is not critical
for viral replication in cultured cells.
PMID- 10684294
TI - Infectious entry pathway of adeno-associated virus and adeno-associated virus
vectors.
AB - We have investigated the infectious entry pathway of adeno-associated virus (AAV)
and recombinant AAV vectors by assessing AAV-mediated gene transfer and by
covalently conjugating fluorophores to AAV and monitoring entry by fluorescence
microscopy. We examined AAV entry in HeLa cells and in HeLa cell lines which
inducibly expressed a dominant interfering mutant of dynamin. The data
demonstrate that AAV internalizes rapidly by standard receptor-mediated
endocytosis from clathrin-coated pits (half-time <10 min). The lysosomotropic
agents ammonium chloride and bafilomycin A(1) prevent AAV-mediated gene transfer
when present during the first 30 min after the onset of endocytosis, indicating
that AAV escapes from early endosomes yet requires an acidic environment for
penetration into the cytosol. Following release from the endosome, AAV rapidly
moves to the cell nucleus and accumulates perinuclearly beginning within 30 min
after the onset of endocytosis. We present data indicating that escape of AAV
from the endosome and trafficking of viral particles to the nucleus are
unaffected by the presence of adenovirus, the primary helper virus for a
productive AAV infection. Within 2 h, viral particles could be detected within
the cell nucleus, suggesting that AAV enters the nucleus prior to uncoating.
Interestingly, the majority of the intracellular virus particles remain in a
stable perinuclear compartment even though gene expression from nuclear AAV
genomes can be detected. This suggests that the process of nuclear entry is rate
limiting or that AAV entry involves multiple pathways. Nevertheless, these data
establish specific points in the AAV infectious entry process and have allowed
the generation of a model for future expansion to specific cell types and AAV
vector analysis in vivo.
PMID- 10684295
TI - Lymphotoxin-alpha-deficient mice can clear a productive infection with murine
gammaherpesvirus 68 but fail to develop splenomegaly or lymphocytosis.
AB - Respiratory challenge with murine gammaherpesvirus 68 (MHV-68) leads to an acute
productive infection of the lung and a persistent latent infection in B
lymphocytes, epithelia, and macrophages. The virus also induces splenomegaly and
an increase in the number of activated CD8 T cells in the circulation.
Lymphotoxin- alpha-deficient (LTalpha(-/-)) mice have no lymph nodes and have
disrupted splenic architecture. Surprisingly, in spite of the severe defect in
secondary lymphoid tissue, LTalpha(-/-) mice could clear a productive MHV-68
infection, although with delayed kinetics compared to wild-type mice, and could
control latent infection. Cytotoxic T-cell activity was comparable in the lungs
and spleens of LTalpha(-/-) and wild-type mice. However, splenic gamma interferon
responses were substantially reduced in LTalpha(-/-) mice. Furthermore, LTalpha(
/-) mice failed to develop splenomegaly or lymphocytosis. Although germinal
centers were absent, LTalpha(-/-) mice were able to class switch and showed
significant virus-specific antibody titers. This work demonstrates that organized
secondary lymphoid tissue is not an absolute requirement for the generation of
immune responses to viral infections.
PMID- 10684296
TI - Expression of two related viral early genes in Epstein-Barr virus-associated
tumors.
AB - The transcription of two early "leftwardly" expressed genes carrying repetitive
sequences, IR2 and IR4, has been studied for Epstein-Barr virus-associated
tumors, and for established B-cell lines, using sequence-specific probes
generated for this purpose. Whereas the IR4 transcript was identified in every
tumor and cell line assessed (except B95-8, with a deletion that removes the
gene), expression of the IR2 gene was restricted to B lymphocytes. Though the
promoters for both transcripts lie within homologous regions (D(L) and D(R)) in
the viral genome, the IR2 promoter appears more tightly regulated. Detailed
characterization of the IR4 transcript from a nasopharyngeal carcinoma tumor,
C15, identifies a sequence variant of this gene that differs from those reported
for B cells; in situ hybridization methods show transcription to be restricted to
a subset of cells, with the strongest signals seen adjacent to host stroma. As
with B cells in culture (Y. Gao, P. R. Smith, L. Karran, Q. L. Lu, and B. E.
Griffin, J. Virol. 71:84-94, 1997), chemical induction enhanced transcriptional
expression of the IR4 gene in the C15 tumor, although staining for both the IR4
antigen and that of the virus lytic switch, Zta, gave negative results. In a
Burkitt's lymphoma biopsy specimen, however, both proteins were found expressed,
notably in the same subset of cells. The data here and elsewhere (Gao et al., J.
Virol., 1997) are consistent with a block to intracellular transport of the
transcript(s) and suggest nuclear roles for it in tumors, possibly in RNA
processing and viral lytic replication. Both roles could be fulfilled in the
absence of translation.
PMID- 10684297
TI - Identification of contact residues and definition of the CAR-binding site of
adenovirus type 5 fiber protein.
AB - The binding of adenovirus (Ad) fiber knob to its cellular receptor, the
coxsackievirus and Ad receptor (CAR), promotes virus attachment to cells and is a
major determinant of Ad tropism. Analysis of the kinetics of binding of Ad type 5
(Ad5) fiber knob to the soluble extracellular domains of CAR together (sCAR) and
each immunoglobulin (Ig) domain (IgV and IgC2) independently by surface plasmon
resonance demonstrated that the IgV domain is necessary and sufficient for
binding, and no additional membrane components are required to confer high
affinity binding to Ad5 fiber knob. Four Ad5 fiber knob mutations, Ser408Glu and
Pro409Lys in the AB loop, Tyr477Ala in the DG loop, and Leu485Lys in beta strand
F, effectively abolished high-affinity binding to CAR, while Ala406Lys and
Arg412Asp in the AB loop and Arg481Glu in beta strand E significantly reduced the
level of binding. Circular dichroism spectroscopy showed that these mutations do
not disorder the secondary structure of the protein, implicating Ser408, Pro409,
Tyr477, and Leu485 as contact residues, with Ala406, Arg412, and Arg481 being
peripherally or indirectly involved in CAR binding. The critical residues have
exposed side chains that form a patch on the surface, which thus defines the high
affinity interface for CAR. Additional site-directed mutagenesis of Ad5 fiber
knob suggests that the binding site does not extend to the adjacent subunit or
toward the edge of the R sheet. These findings have implications for our
understanding of the biology of Ad infection, the development of novel Ad vectors
for targeted gene therapy, and the construction of peptide inhibitors of Ad
infection.
PMID- 10684298
TI - Herpesvirus mRNAs are sorted for export via Crm1-dependent and -independent
pathways.
AB - Cellular pre-mRNA splicing is inhibited by ICP27, a herpes simplex virus
regulatory protein, resulting in the shutoff of host protein synthesis. Here we
reveal that ICP27 also mediates the export of some virus RNAs via a Crm1
dependent pathway and present evidence that independent domains are required for
these functions. Sorting of some viral mRNAs for nuclear export requires Crm1,
while other virus mRNAs are exported via another pathway.
PMID- 10684299
TI - Identification of a boundary domain adjacent to the potent human cytomegalovirus
enhancer that represses transcription of the divergent UL127 promoter.
AB - Transcriptional repression within a complex modular promoter may play a key role
in determining the action of enhancer elements. In human cytomegalovirus, the
major immediate-early promoter (MIEP) locus contains a highly potent and complex
modular enhancer. Evidence is presented suggesting that sequences of the MIEP
between nucleotide positions -556 and -673 function to prevent transcription
activation by enhancer elements from the UL127 open reading frame divergent
promoter. Transient transfection assays of reporter plasmids revealed repressor
sequences located between nucleotides -556 and -638. The ability of these
sequences to confer repression in the context of an infection was shown using
recombinant viruses generated from a bacterial artificial chromosome containing
an infectious human cytomegalovirus genome. In addition to repressor sequences
between -556 and -638, infection experiments using recombinant virus mutants
indicated that sequences between -638 and -673 also contribute to repression of
the UL127 promoter. On the basis of in vitro transcription and transient
transfection assays, we further show that interposed viral repressor sequences
completely inhibit enhancer-mediated activation of not only the homologous but
also heterologous promoters. These and other experiments suggest that repression
involves an interaction of host-encoded regulatory factors with defined promoter
sequences that have the property of proximally interfering with upstream enhancer
elements in a chromatin-independent manner. Altogether, our findings establish
the presence of a boundary domain that efficiently blocks enhancer-promoter
interactions, thus explaining how the enhancer can work to selectively activate
the MIEP.
PMID- 10684300
TI - Hepatitis B virus X protein colocalizes to mitochondria with a human voltage
dependent anion channel, HVDAC3, and alters its transmembrane potential.
AB - Understanding the mechanism(s) of action of the hepatitis B virus (HBV)-encoded
protein HBx is fundamental to elucidating the underlying mechanisms of chronic
liver disease and hepatocellular carcinoma caused by HBV infection. In our
continued attempts to identify cellular targets of HBx, we have previously
reported the identification of a novel cellular protein with the aid of a yeast
two-hybrid assay. This cellular gene was identified as a third member of the
family of human genes that encode the voltage-dependent anion channel (HVDAC3).
In the present study, physical interaction between HBx and HVDAC3 was established
by standard in vitro and in vivo methods. Confocal laser microscopy of
transfected cells with respective expression vectors colocalized HVDAC3 and HBx
to mitochondria. This novel, heretofore unreported subcellular distribution of
HBx in mitochondria implies a functional role of HBx in functions associated with
mitochondria. Using a stable cationic fluorophore dye, CMXRos, we show that HBx
expression in cultured human hepatoma cells leads to alteration of mitochondrial
transmembrane potential. Such functional roles of HBx in affecting mitochondrial
physiology have implications for HBV-induced liver injury and the development of
hepatocellular carcinoma.
PMID- 10684301
TI - Subcellular redistribution of Pit-2 P(i) transporter/amphotropic leukemia virus
(A-MuLV) receptor in A-MuLV-infected NIH 3T3 fibroblasts: involvement in
superinfection interference.
AB - Amphotropic murine leukemia virus (A-MuLV) utilizes the Pit-2 sodium-dependent
phosphate transporter as a cell surface receptor to infect mammalian cells.
Previous studies established that infection of cells with A-MuLV resulted in the
specific down-modulation of phosphate uptake mediated by Pit-2 and in resistance
to superinfection with A-MuLV. To study the mechanisms underlying these
phenomena, we constructed plasmids capable of efficiently expressing epsilon
epitope- and green fluorescent protein (GFP)-tagged human Pit-2 proteins in
mammalian cells. Overexpression of epsilon-epitope-tagged Pit-2 transporters in
NIH 3T3 cells resulted in a marked increase in sodium-dependent P(i) uptake. This
increase in P(i) uptake was specifically blocked by A-MuLV infection but not by
infection with ecotropic MuLV (E-MuLV) (which utilizes a cationic amino acid
transporter, not Pit-2, as a cell surface receptor). These data, together with
the finding that the tagged Pit-2 transporters retained their A-MuLV receptor
function, indicate that the insertion of epitope tags does not affect either
retrovirus receptor or P(i) transporter function. The overexpressed epitope
tagged transporters were detected in cell lysates, by Western blot analysis using
both epsilon-epitope- and GFP-specific antibodies as well as with Pit-2
antiserum. Both the epitope- and GFP-tagged transporters showed almost exclusive
plasma membrane localization when expressed in NIH 3T3 cells, as determined by
laser scanning confocal microscopy. Importantly, when NIH 3T3 cells expressing
these proteins were productively infected with A-MuLV, the tagged transporters
and receptors were no longer detected in the plasma membrane but rather were
localized to a punctate structure within the cytosolic compartment distinct from
Golgi, endoplasmic reticulum, endosomes, lysosomes, and mitochondria. The
intracellular Pit-2 pool colocalized with the virus in A-MuLV-infected cells. A
similar redistribution of the tagged Pit-2 proteins was not observed following
infection with E-MuLV, indicating that the redistribution of Pit-2 is not
directly attributable to general effects associated with retroviral infection but
rather is a specific consequence of A-MuLV-Pit-2 interactions.
PMID- 10684302
TI - Role of the Gag matrix domain in targeting human immunodeficiency virus type 1
assembly.
AB - Human immunodeficiency virus type 1 (HIV-1) particle formation and the subsequent
initiation of protease-mediated maturation occur predominantly on the plasma
membrane. However, the mechanism by which HIV-1 assembly is targeted specifically
to the plasma membrane versus intracellular membranes is largely unknown.
Previously, we observed that mutations between residues 84 and 88 of the matrix
(MA) domain of HIV-1 Gag cause a retargeting of virus particle formation to an
intracellular site. In this study, we demonstrate that the mutant virus assembly
occurs in the Golgi or in post-Golgi vesicles. These particles undergo core
condensation in a protease-dependent manner, indicating that virus maturation can
occur not only on the plasma membrane but also in the Golgi or post-Golgi
vesicles. The intracellular assembly of mutant particles is dependent on Gag
myristylation but is not influenced by p6(Gag) or envelope glycoprotein
expression. Previous characterization of viral revertants suggested a functional
relationship between the highly basic domain of MA (amino acids 17 to 31) and
residues 84 to 88. We now demonstrate that mutations in the highly basic domain
also retarget virus particle formation to the Golgi or post-Golgi vesicles.
Although the basic domain has been implicated in Gag membrane binding, no
correlation was observed between the impact of mutations on membrane binding and
Gag targeting, indicating that these two functions of MA are genetically
separable. Plasma membrane targeting of Gag proteins with mutations in either the
basic domain or between residues 84 and 88 was rescued by coexpression with wild
type Gag; however, the two groups of MA mutants could not rescue each other. We
propose that the highly basic domain of MA contains a major determinant of HIV-1
Gag plasma membrane targeting and that mutations between residues 84 and 88
disrupt plasma membrane targeting through an effect on the basic domain.
PMID- 10684303
TI - Identification and analysis of the K5 gene of Kaposi's sarcoma-associated
herpesvirus.
AB - Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8 (HHV-8),
belongs to the gammaherpesvirus subfamily and encodes approximately 80 open
reading frames (ORFs). Among them are a few candidates for immediate-early genes
(e.g., K5). We developed a monoclonal antibody (MAb), 328C7, against the K5
antigen. This MAb reacted with the K5 gene product by immunoscreening of a cDNA
library from BCBL-1 cells, and this result was confirmed by transfection of the
K5 ORF into Cos-7 cells. After induction of lytic infection by treatment with 12
O-tetradecanoylphorbol-13-acetate, MAb 328C7 reacted with an antigen in the
cytoplasm of BCBL-1 and BC-3 cells as early as after 4 h of induction.
Immunoelectron microscopy showed that the K5 antigen was situated mainly in the
endoplasmic reticulum but was not present on the virion or in the nucleus.
Northern blotting with a K5-specific probe revealed a single transcript of 1.2
kb, while Western blotting showed the antigen to be a 36-kDa polypeptide. The 5'
and 3' ends were then determined by rapid amplification of cDNA, followed by
sequencing of RACE products, and a splice was revealed upstream of the K5 ORF. K5
expression was unaffected by the respective DNA and protein synthesis inhibitors
phosphonoformic acid and cycloheximide plus actinomycin D, confirming its
immediate-early nature. Transient-transfection assays showed that the K5 promoter
was transactivated by ORF 50 (KSHV Rta), a homolog of Epstein-Barr virus Rta, but
the K5 gene product exhibited no transregulation of its own promoter or those of
DNA polymerase and the human immunodeficiency virus type 1 long terminal repeat.
This is the first such analysis of an immediate-early gene product; determination
of its specific biological function requires further investigation.
PMID- 10684304
TI - Bovine herpesvirus 1 U(L)3.5 interacts with bovine herpesvirus 1 alpha
transinducing factor.
AB - The bovine herpesvirus 1 (BHV-1) U(L)3.5 gene encodes a 126-amino-acid tegument
protein. Homologs of U(L)3.5 are present in some alphaherpesviruses and have 20
to 30% overall amino acid homology that is concentrated in the N-terminal 50
amino acids. Mutant pseudorabies virus lacking U(L)3.5 is deficient in viral
egress but can be complemented by BHV-1 U(L)3.5 (W. Fuchs, H. Granzow, and T. C.
Mettenleiter, J. Virol. 71:8886-8892, 1997). The function of BHV-1 U(L)3.5 in BHV
1 replication is not known. To get a better understanding of its function, we
sought to identify the proteins that interact with the BHV-1 U(L)3.5 protein. By
using an in vitro pull-down assay and matrix-assisted laser desorption ionization
mass spectrometry analysis, we identified BHV-1 alpha-transinducing factor
(alphaBTIF) as a BHV-1 U(L)3. 5-interacting protein. The interaction was verified
by coimmunoprecipitation from virus-infected cells using an antibody to either
protein, by indirect immunofluorescence colocalization in both virus-infected and
transfected cells, and by the binding of in vitro-translated proteins. In virus
infected cells, U(L)3.5 and alphaBTIF colocalized in a Golgi-like subcellular
compartment late in infection. In transfected cells, they colocalized in the
nucleus. Deletion of 20 amino acids from the N terminus of U(L)3.5, but not 40
amino acids from the C terminus, abolished the U(L)3.5-alphaBTIF interaction both
in vitro and in vivo. The interaction between U(L)3. 5 and alphaBTIF may be
important for BHV-1 maturation and regulation of alphaBTIF transactivation
activity.
PMID- 10684305
TI - The intact retroviral Env glycoprotein of human foamy virus is a trimer.
AB - Electron microscopy of negatively stained human foamy virus particles provides
direct evidence for the trimeric nature of intact Env surface glycoproteins.
Three-dimensional image reconstruction reveals that the Env trimer is a tapering
spike 14 nm in length. The spikes were often arranged in hexagonal rings which
shared adjacent Env trimers.
PMID- 10684306
TI - Recombinant adeno-associated virus expressing human papillomavirus type 16 E7
peptide DNA fused with heat shock protein DNA as a potential vaccine for cervical
cancer.
AB - In this study, we explore a potential vaccine for human papillomavirus (HPV)
induced tumors, using heat shock protein as an adjuvant, a peptide vaccine for
safety, and adeno-associated virus (AAV) as a gene delivery vector. The tumor
vaccine was devised by constructing a chimeric gene which contained HPV type 16
E7 cytotoxic T-lymphocyte (CTL) epitope DNA (M. C. Feltkamp, H. L. Smits, M. P.
Vierboom, R. P. Minnaar, B. M. de Jongh, J. W. Drijfhout, J. ter Schegget, C. J.
Melief, and W. M. Kast, Eur. J. Immunol. 23:2242-2249, 1993) fused with the heat
shock protein gene as a tumor vaccine delivered via AAV. Our results demonstrate
that this vaccine can eliminate tumor cells in syngeneic animals and induce CD4-
and CD8-dependent CTL activity in vitro. Moreover, studies with knockout mice
with distinct T-cell deficiencies confirm that CTL-induced tumor protection is
CD4 and CD8 dependent. Taken together, the evidence indicates that this chimeric
gene delivered by AAV has potential as a cervical cancer vaccine.
PMID- 10684308
TI - Superantigen expression is driven by both mouse mammary tumor virus long terminal
repeat-associated promoters in transgenic mice.
AB - In addition to the usual retroviral promoter, the mouse mammary tumor virus
(MMTV) long terminal repeat carries a second promoter located in the U3 region.
Here we show that both of these promoters are independently able to give rise to
superantigen activity in transgenic mice. The ability of multiple MMTV promoters
to drive superantigen expression underscores its importance in the virus life
cycle.
PMID- 10684307
TI - Productive replication of human adenoviruses in mouse epidermal cells.
AB - In contrast to most cells of mouse origin, cell lines derived from mouse
epidermis are permissive for replication of human adenovirus type 5. The extent
of epidermal cell differentiation correlated with the level of E1A expression and
virus replication. Mouse epidermal cells may provide useful models for cancer
therapy using replication-competent human adenoviruses.
PMID- 10684309
TI - Interaction of yellow fever virus French neurotropic vaccine strain with monkey
brain: characterization of monkey brain membrane receptor escape variants.
AB - Binding of yellow fever virus wild-type strains Asibi and French viscerotropic
virus and vaccine strains 17D and FNV to monkey brain and monkey liver cell
membrane receptor preparations (MRPs) was investigated. Only FNV bound to monkey
brain MRPs, while French viscerotropic virus, Asibi, and FNV all bound to monkey
liver MRPs. Four monkey brain and two mouse brain MRP escape (MRP(R)) variants of
FNV were selected at pH 7.6 and 6.0. Three monkey brain MRP(R) variants selected
at pH 7.6 each had only one amino acid substitution in the envelope (E) protein
in domain II (E-237, E-260, or E274) and were significantly attenuated in mice
following intracerebral inoculation. Two of the variants were tested in monkeys
and retained parental neurotropism following intracerebral inoculation at the
dose tested. We speculate that this region of domain II is involved in binding of
FNV E protein to monkey brain and is, in part, responsible for the enhanced
neurotropism of FNV for monkeys. A monkey brain MRP(R) variant selected at pH 6.0
and two mouse brain MRP(R) variants selected at pH 7.6 were less attenuated in
mice, and each had an amino acid substitution in the transmembrane region of the
E protein (E-457 or E-458).
PMID- 10684310
TI - Nef-induced major histocompatibility complex class I down-regulation is
functionally dissociated from its virion incorporation, enhancement of viral
infectivity, and CD4 down-regulation.
AB - The N-terminal alpha-helix domain of the human immunodeficiency virus type 1 (HIV
1) Nef protein plays important roles in enhancement of viral infectivity, virion
incorporation of Nef, and the down-regulation of major histocompatibility complex
class I (MHC-I) expression on cell surfaces. In this study, we demonstrated that
Met 20 in the alpha-helix domain was indispensable for the ability of Nef to
modulate MHC-I expression but not for other events. We also showed that Met 20
was unnecessary for the down-regulation of CD4. These findings indicate that the
region governing MHC-I down-regulation is proximate in the alpha-helix domain but
is dissociated functionally from that determining enhancement of viral
infectivity, virion incorporation of Nef, and CD4 down-regulation.
PMID- 10684311
TI - Herpes simplex virus ICP27 induces cytoplasmic accumulation of unspliced
polyadenylated alpha-globin pre-mRNA in infected HeLa cells.
AB - Transcripts of most intron-bearing cellular genes must be processed by the
splicing machinery in order to efficiently accumulate and gain access to the
cytoplasm. However, we found that herpes simplex virus induces cytoplasmic
accumulation of both spliced and unspliced polyadenylated alpha-globin RNAs in
infected HeLa cells. Accumulation of the unspliced RNA required the immediate
early protein ICP27, and ICP27 was sufficient (in combination with ICP4) to
produce this effect in a transient-transfection assay. However, expression of
ICP27 did not markedly alter the levels of fully spliced alpha-globin transcripts
in infected cells. These data demonstrate that the previously documented effects
of ICP27 on the cellular splicing apparatus do not greatly inhibit splicing of
alpha-globin RNA and argue that ICP27 induces a splicing-independent pathway for
alpha-globin RNA accumulation and nuclear export.
PMID- 10684312
TI - Enhancement of immunoglobulin G2a and cytotoxic T-lymphocyte responses by a
booster immunization with recombinant hepatitis C virus E2 protein in E2 DNA
primed mice.
AB - The induction of strong cytotoxic T-lymphocyte (CTL) and humoral responses appear
to be essential for the elimination of persistently infecting viruses, such as
hepatitis C virus (HCV). Here, we tested several vaccine regimens and demonstrate
that a combined vaccine regimen, consisting of HCV E2 DNA priming and boosting
with recombinant E2 protein, induces the strongest immune responses to HCV E2
protein. This combined vaccine regimen augments E2-specific immunoglobulin G2a
(IgG2a) and CD8(+) CTL responses to a greater extent than immunizations with
recombinant E2 protein and E2 DNA alone, respectively. In addition, the data
showed that a protein boost following one DNA priming was also effective, but
much less so than those following two DNA primings. These data indicate that
sufficient DNA priming is essential for the enhancement of DNA encoded antigen
specific immunity by a booster immunization with recombinant E2 protein.
Furthermore, the enhanced CD8(+) CTL and IgG2a responses induced by our combined
vaccine regimens are closely associated with the protection of BALB/c mice from
challenge with modified CT26 tumor cells expressing HCV E2 protein. Together, our
results provide important implications for vaccine development for many
pathogens, including HCV, which require strong antibody and CTL responses.
PMID- 10684313
TI - A 13-amino-acid Pit1-specific loop 4 sequence confers feline leukemia virus
subgroup B receptor function upon Pit2.
AB - Feline leukemia virus subgroup B (FeLV-B) and gibbon ape leukemia virus (GALV)
utilize the human protein Pit1 but not the related protein, Pit2, as receptor. A
stretch of 9 amino acids, named region A, was identified in the putative fourth
extracellular loop of Pit1 (residues 550 through 558) as critical for FeLV-B and
GALV receptor function. However, the presence of Pit1 region A did not confer
receptor function for FeLV-B upon Pit2, while it did so for GALV. We have here
shown that the presence of two Pit1-specific loop 4 residues (tyrosine 546 and
valine 548) in addition to Pit1 region A is sufficient to make Pit2 an efficient
FeLV-B receptor; that is, a stretch of 13 amino acids encompassing all loop 4
amino acid differences between Pit1 and Pit2 comprises a C-terminal determinant
for FeLV-B receptor function. Thus, the same limited receptor region is
sufficient to confer receptor function for both viruses upon Pit2.
PMID- 10684314
TI - The SU and TM envelope protein subunits of bovine leukemia virus are linked by
disulfide bonds, both in cells and in virions.
AB - After the polyprotein precursor of retroviral envelope proteins is
proteolytically cleaved, the surface (SU) and transmembrane (TM) subunits remain
associated with each other by noncovalent interactions or by disulfide bonds.
Disulfide linkages confer a relatively stable association between the SU and TM
envelope protein subunits of Rous sarcoma virus and murine leukemia virus. In
contrast, the noncovalent association between SU and TM of human immunodeficiency
virus leads to significant shedding of SU from the surface of infected cells. The
SU and TM proteins of bovine leukemia virus (BLV) initially were reported to be
disulfide linked but later were concluded not to be, since TM is often lost
during purification of SU protein. Here, we show that SU and TM of BLV do,
indeed, associate through disulfide bonds, whether the envelope proteins are
overexpressed in transfected cells, are produced in virus-infected cells, or are
present in newly produced virions.
PMID- 10684315
TI - Mutational analysis of adeno-associated virus type 2 Rep68 protein endonuclease
activity on partially single-stranded substrates.
AB - The endonuclease activity of the Rep68 and Rep78 proteins (Rep68/78) of adeno
associated virus type 2 (AAV) cuts at the terminal resolution site (trs) within
the hairpin structure formed by the AAV inverted terminal repeats. Recent studies
suggest that a DNA unwinding function of Rep68/78 may be required for
endonuclease activity. We demonstrate that several mutant proteins which are
endonuclease negative on a fully duplex hairpin substrate are endonuclease
positive on a partially single-stranded hairpin substrate. Truncation analysis
revealed that the endonuclease function is contained within the first 200 amino
acids of Rep68/78. This endonucleolytic cleavage is believed to involve the
covalent attachment of Rep68/78 to the trs via a phosphate-tyrosine linkage. A
previous report (S. L. Walker, R. S. Wonderling, and R. A. Owens, J. Virol.
71:2722-2730, 1997) suggested that tyrosine 152 was part of the active site. We
individually mutated each tyrosine within the first 200 amino acids of the Rep68
moiety of a maltose binding protein-Rep68/78 fusion protein to phenylalanine.
Only mutation of tyrosine 156 resulted in a protein incapable of covalent
attachment to a partially single-stranded hairpin substrate, suggesting that
tyrosine 156 is part of the endonuclease active site.
PMID- 10684316
TI - Functional reconstitution of thymopoiesis after human immunodeficiency virus
infection.
AB - We have utilized combination antiretroviral therapy following human
immunodeficiency virus type 1-induced human CD4(+) thymocyte depletion in the
SCID-hu mouse to examine the immune competence of reconstituting thymocytes which
appear following administration of combination therapy. These cells express a
normal distribution of T-cell receptor variable gene families and are responsive
to costimulatory signals. These results suggest that normal thymic function may
be restored following antiretroviral treatment.
PMID- 10684317
TI - Characterization of the R572T point mutant of a putative cleavage site in human
foamy virus Env.
AB - A putative cleavage site of the human foamy virus (HFV) envelope glycoprotein
(Env) was altered. Transient env expression revealed that the R572T mutant Env
was normally expressed and modified by asparagine-linked oligosaccharide chains.
However, this single-amino-acid substitution was sufficient to abolish all
detectable cleavage of the gp130 precursor polyprotein. Cell surface
biotinylation demonstrated that the uncleaved mutant gp130 was transported to the
plasma membrane. The uncleaved mutant protein was incapable of syncytium
formation. Glycoprotein-driven virion budding, a unique aspect of HFV assembly,
occurred despite the absence of Env cleavage. We then substituted the R572T
mutant env into a replication-competent HFV molecular clone. Transfection of the
mutant viral DNA into BHK-21 cells followed by viral titration with the FAB
(foamy virus-activated beta-galactosidase expression) assay revealed that
proteolysis of the HFV Env was essential for viral infectivity. Wild-type HFV Env
partially complemented the defective virus phenotype. Taken together, these
experimental results established the location of the HFV Env proteolytic site;
the effects of cleavage on Env transport, processing, and function; and the
importance of Env proteolysis for virus maturation and infectivity.
PMID- 10684318
TI - Hepadnavirus infection in captive gibbons.
AB - The recent isolation of a nonhuman primate hepadnavirus from woolly monkeys
prompted an examination of other primates for potentially new hepadnaviruses. A
serological analysis of 30 captive gibbons revealed that 47% were positive for at
least one marker of ongoing or previous infection with a hepatitis B virus (HBV).
The amino acid sequences of the core and surface genes of human and gibbon virus
isolates were very similar. Phylogenetic analysis indicated that the gibbon
isolates lie within the human HBV family, indicating that these HBV isolates most
likely stem from infection of gibbons from a human source.
PMID- 10684319
TI - Recombinant modified vaccinia virus ankara expressing the surface gp120 of simian
immunodeficiency virus (SIV) primes for a rapid neutralizing antibody response to
SIV infection in macaques.
AB - Neutralizing antibodies were assessed before and after intravenous challenge with
pathogenic SIVsmE660 in rhesus macaques that had been immunized with recombinant
modified vaccinia virus Ankara expressing one or more simian immunodeficiency
virus gene products (MVA-SIV). Animals received either MVA-gag-pol, MVA-env, MVA
gag-pol-env, or nonrecombinant MVA. Although no animals were completely protected
from infection with SIV, animals immunized with recombinant MVA-SIV vaccines had
lower virus loads and prolonged survival relative to control animals that
received nonrecombinant MVA (I. Ourmanov et al., J. Virol. 74:2740-2751, 2000).
Titers of neutralizing antibodies measured with the vaccine strain SIVsmH-4 were
low in the MVA-env and MVA-gag-pol-env groups of animals and were undetectable in
the MVA-gag-pol and nonrecombinant MVA groups of animals on the day of challenge
(4 weeks after final immunization). Titers of SIVsmH-4-neutralizing antibodies
remained unchanged 1 week later but increased approximately 100-fold 2 weeks
postchallenge in the MVA-env and MVA-gag-pol-env groups while the titers remained
low or undetectable in the MVA-gag-pol and nonrecombinant MVA groups. This
anamnestic neutralizing antibody response was also detected with T-cell-line
adapted stocks of SIVmac251 and SIV/DeltaB670 but not with SIVmac239, as this
latter virus resisted neutralization. Most animals in each group had high titers
of SIVsmH-4-neutralizing antibodies 8 weeks postchallenge. Titers of neutralizing
antibodies were low or undetectable until about 12 weeks of infection in all
groups of animals and showed little or no evidence of an anamnestic response when
measured with SIVsmE660. The results indicate that recombinant MVA is a promising
vector to use to prime for an anamnestic neutralizing antibody response following
infection with primate lentiviruses that cause AIDS. However, the Env component
of the present vaccine needs improvement in order to target a broad spectrum of
viral variants, including those that resemble primary isolates.
PMID- 10684320
TI - Pitfalls in the interpretation of common biochemical tests.
AB - This review considers some of the more common problems in the interpretation of
the results of biochemical tests and, where possible, highlights ways in which
errors can be identified or avoided.
PMID- 10684321
TI - Amiodarone-induced thyroid disorders: a clinical review.
AB - Although amiodarone is regarded as a highly effective anti-arrhythmic agent, its
use may lead to alterations in thyroid gland function and/or thyroid hormone
metabolism, partly because of its rich iodine content. Patients treated with
amiodarone may manifest altered thyroid hormone profile without thyroid
dysfunction, or they may present with clinically significant amiodarone-induced
hypothyroidism or amiodarone-induced thyrotoxicosis. The former results from the
inability of the thyroid to escape from the Wolff-Chaikoff effect. It prevails in
areas with high dietary iodine intake, and it is readily managed by
discontinuation of amiodarone or thyroid hormone replacement. Amiodarone-induced
thyrotoxicosis occurs more frequently in areas with low iodine intake; it may
arise from iodine-induced excessive thyroid hormone synthesis (type I) or
destructive thyroiditis with release of preformed hormones (type II). Type I
should be treated with thionamides alone or in combination with potassium
perchlorate, whereas type II benefits from treatment with glucocorticoids.
Surgery may be a feasible option for patients who require long-term amiodarone
treatment.
PMID- 10684322
TI - Helicobacter pylori.
AB - Helicobacter pylori infection is a major cause of peptic ulcer disease, and its
detection and eradication are now an important part of gastroenterology.
Effective regimes are available which will eliminate the organism in about 90% of
cases in developed countries.
PMID- 10684323
TI - Carbohydrate-deficient glycoprotein syndromes.
AB - Four types of carbohydrate-deficient glycoprotein syndrome have been described,
and the cause of two of them has been found. The symptoms and signs of these
syndromes are described, with variations that occur at different ages. The
commonest is type Ia with an autosomal recessive form of inheritance, and the
gene responsible has been mapped to 16p. The typical pathology is atrophy of the
cerebellum and brainstem, sometimes also involving the cortex, although both the
pathology and the biochemical deficiencies vary between different types of
syndrome. The diagnosis depends firstly on recognising the clinical features,
including the presence of complications such as thyroid disorders. Then
biochemical tests can be carried out, especially chromatographic carbohydrate
deficient transferrin assay and isoelectric focusing of serum transferrin. The
prognosis depends on the complications, renal, hepatic, and cardiac, but affected
children will be severely handicapped. Therefore treatment consists mainly of
coping with the complications, and supporting the child and the family. Oral
infusion of mannose can be effective in type Ib disease.
PMID- 10684324
TI - Evaluation of patients admitted with hypoglycaemia to a teaching hospital in
Central Anatolia.
AB - Hypoglycaemia is one of the most common endocrine emergencies in practice. We
analysed retrospectively the incidence and causes of hypoglycaemia in patients
admitted to Erciyes University Medical School in Turkey between January 1991 and
June 1998 because of hypoglycaemia. Charts were reviewed according to multiple
variables including age, sex, blood glucose levels, renal and liver functions,
diagnoses, symptoms, drugs, complications, sequelae, and survival status. During
this period, 13 500 patients were hospitalised and hypoglycaemia was reported in
126 (0.9%) patients. The most common causes were diabetic treatments in 54 cases
(42%), endocrine deficiencies in 25 cases (20%), and malignancy in 15 cases
(12%), respectively. The leading endocrine deficiency was panhypopituitarism.
Sheehan's syndrome was the most common cause of panhypopituitarism (44%). No
underlying cause was diagnosed in seven cases. Nine patients died (7%) and
neurological sequelae were observed in one patient with diabetes mellitus. We
conclude that hypoglycaemia accounts for about 1% of hospital admissions.
Although the hypoglycaemia could be attributed to hypoglycaemic agents in the
treatment of diabetes mellitus in the majority of cases, Sheehan's syndrome was
also found to be an important cause of hypoglycaemia in our hospital.
PMID- 10684325
TI - Prevalence of mental illness in a rehabilitation unit for older adults.
AB - The prevalence of psychiatric disorders was studied in 78 elderly people in a
rehabilitation unit for older adults. The patients were assessed using the Evans
Liverpool depression rating scale, Hospital Anxiety and Depression scale and Mini
Mental State Examination. Twenty-eight (35.9%) patients were found to be
depressed, 15 of these also had raised anxiety. Thirty-one (41.0%) patients had
significant cognitive impairment and 14 of these had associated depression. Only
33 (42%) had no evidence of either cognitive impairment or mood disorder. On
discharge, 20 (25.6%) patients were on antidepressant treatment but only 50% of
those had this diagnosis recorded on the discharge summary. Our results showed
higher prevalence of depression in this situation compared with the reported
prevalence of 20-30% in the acute hospital setting. We recommend that all
patients undergoing rehabilitation should be routinely screened for depression as
it is common and treatment will improve the overall outcome.
PMID- 10684326
TI - Day-case percutaneous endoscopic gastrostomy: a viable proposition?
AB - The aim of our study was to evaluate the success rate, complications, and long
term outcomes following day-case percutaneous endoscopic gastrostomy (PEG). This
retrospective study was carried out in a 650-bed District General hospital in
Northamptonshire, UK. Thirty-six patients, aged 28-90 years, were included in the
study, 21 males (58%) and 15 females (42%). Indications for PEG insertion
included head and neck cancer, dysphagia as a result of primary disease, and AIDS
related malnutrition. Data were collected from the medical and dietetic records.
The PEG procedure was successful in 33 patients (92%). In 32 cases (97%) the
patient was discharged home. Twenty five of the patients (76%) suffered no
complications whilst seven (21%) suffered complications within a month of the
procedure. No patient required further surgical intervention. Five patients (15%)
died of their primary disease within a month of the procedure. Patients had had
their PEG tubes in situ for up to 2.5 years at the end of data collection. We
conclude that PEG can be performed as a day-case procedure in stable patients
with no increase in complication rate, morbidity, or mortality.
PMID- 10684327
TI - Recurrence of adrenal aldosterone-producing adenoma.
AB - Conn's syndrome (adrenal aldosterone-producing adenoma) and bilateral adrenal
hyperplasia are the most common causes of primary aldosteronism. The treatment of
choice for patients with aldosterone-producing adenoma is unilateral total
adrenalectomy. Recurrence after adequate surgery is exceptional. We present a
patient with recurrence of an aldosterone-producing adenoma in the right adrenal
gland 9 years after adenomectomy of a aldosterone-producing adenoma in the same
adrenal gland. We conclude that adenomectomy is not an adequate therapy for
patients with adrenal aldosterone-producing adenoma.
PMID- 10684328
TI - Can myasthenia gravis be diagnosed with the 'ice pack test'? A cautionary note.
AB - The ice pack test may be helpful in establishing that ptosis is due to ocular
myasthenia gravis, since cold improves neuromuscular transmission. However, the
role of the test in determining whether diplopia is of myasthenic origin has yet
to be established.
PMID- 10684329
TI - Syncope after effort.
AB - A 29-year-old man developed recurrent syncope following exertion. Cardiac
investigations revealed no evidence of structural heart disease, but during
exercise testing, in the recovery phase, he sustained a bradycardia and then
asystole for a prolonged period. Before cardiac massage could be instituted a
tonic-clonic fit occurred, and this initiated a return to sinus rhythm. His
symptoms were abolished following the implantation of a dual-chamber pacemaker.
PMID- 10684330
TI - Brittle Addison's disease: a new variation on a familiar theme.
AB - Unstable and unpredictable disease control in diabetes or asthma, with frequent
hospitalisations, is frequently referred to as 'brittle'. We describe two cases
of Addison's disease with recurrent hospitalisations in hypo-adrenal crises. Both
patients had significant psychosocial disruption, and failure to take
hydrocortisone replacement therapy was admitted in one and biochemically proven
in the other. We propose that 'brittle' Addison's disease in these cases was due
to poor treatment compliance related to psychosocial factors. These features have
particular similarities with the syndrome of brittle diabetes.
PMID- 10684331
TI - Chest pain, enzymes and hypothyroidism.
AB - Hypothyroidism is a common disorder and when presenting with classical symptoms
and signs is easy to recognise. However, hypothyroidism may present in a manner
suggestive of an acute myocardial infarction with an elevated creatine kinase and
electrocardiographic abnormalities. We report a case of severe hypothyroidism
presenting as a cardiac event whose symptoms and signs dispersed following
treatment with thyroxine.
PMID- 10684332
TI - Rapidly progressing tetraparesis in a young male patient with pyrexia.
PMID- 10684333
TI - Hyperthyroidism in an elderly patient.
PMID- 10684335
TI - Isosexual precocity: uncommon presentation of a common disorder.
PMID- 10684334
TI - A case of intestinal obstruction.
PMID- 10684336
TI - Calf hypertrophy following paralytic poliomyelitis.
PMID- 10684337
TI - A healthy patient who suddenly developed a foot-drop.
PMID- 10684338
TI - An unusual cause of bowel obstruction.
PMID- 10684339
TI - Disseminated intravascular coagulation and vasculitis during propylthiouracil
therapy.
PMID- 10684341
TI - A colour handbook of dermatology
PMID- 10684340
TI - Virtual endoscopy of the upper airway--a diagnostic tool.
PMID- 10684342
TI - Sigmundoscopy. medical-psychiatric consultation-liaison. The bases
PMID- 10684343
TI - Guidelines in clinical practice
PMID- 10684344
TI - Molecular evolution of the GATA family of transcription factors: conservation
within the DNA-binding domain.
AB - The GATA-binding transcription factors comprise a protein family whose members
contain either one or two highly conserved zinc finger DNA-binding domains.
Members of this group have been identified in organisms ranging from cellular
slime mold to vertebrates, including plants, fungi, nematodes, insects, and
echinoderms. While much work has been done describing the expression patterns,
functional aspects, and target genes for many of these proteins, an evolutionary
analysis of the entire family has been lacking. Herein we show that only the C
terminal zinc finger (Cf) and basic domain, which together constitute the GATA
binding domain, are conserved throughout this protein family. Phylogenetic
analyses of amino acid sequences demonstrate distinct evolutionary pathways.
Analysis of GATA factors isolated from vertebrates suggests that the six distinct
vertebrate GATAs are descended from a common ancestral sequence, while those
isolated from nonvertebrates (with the exception of the fungal AREA orthologues
and Arabidopsis paralogues) appear to be related only within the DNA-binding
domain and otherwise provide little insight into their evolutionary history.
These results suggest multiple modes of evolution, including gene duplication and
modular evolution of GATA factors based upon inclusion of a class IV zinc finger
motif. As such, GATA transcription factors represent a group of proteins related
solely by their homologous DNA-binding domains. Further analysis of this domain
examines the degree of conservation at each amino acid site using the Boltzmann
entropy measure, thereby identifying residues critical to preservation of
structure and function. Finally, we construct a predictive motif that can
accurately identify potential GATA proteins.
PMID- 10684345
TI - The presence of GSI-like genes in higher plants: support for the paralogous
evolution of GSI and GSII genes.
AB - Glutamine synthetase type I (GSI) genes have previously been described only in
prokaryotes except that the fungus Emericella nidulans contains a gene (fluG)
which encodes a protein with a large N-terminal domain linked to a C-terminal GSI
like domain. Eukaryotes generally contain the type II (GSII) genes which have
been shown to occur also in some prokaryotes. The question of whether GSI and
GSII genes are orthologues or paralogues remains a point of controversy. In this
article we show that GSI-like genes are widespread in higher plants and have
characterized one of the genes from the legume Medicago truncatula. This gene is
part of a small gene family and is expressed in many organs of the plant. It
encodes a protein similar in size and with between 36 and 46% amino acid sequence
similarity to prokaryotic GS proteins used in the analyses, whereas it is larger
and with less than 25% similarity to GSII proteins, including those from the same
plant species. Phylogenetic analyses suggest that this protein is most similar to
putative proteins encoded by expressed sequence tags of other higher plant
species (including dicots and a monocot) and forms a cluster with FluG as the
most divergent of the GSI sequences. The discovery of GSI-like genes in higher
plants supports the paralogous evolution of GSI and GSII genes, which has
implications for the use of GS in molecular studies on evolution.
PMID- 10684346
TI - Disparate evolution of paralogous introns in the Xdh gene of Drosophila.
AB - Drosophila nuclear introns are commonly assumed to change according to a single
rate of substitution, yet little is known about the evolution of these non-coding
sequences. The hypothesis of a uniform substitution rate for introns seems to be
at odds with recent findings that the nucleotide composition of introns varies at
a scale unknown before, and that their base content variation is correlated with
that of the adjacent exons. However, no direct attempt at comparing substitution
rates in introns seems to have been addressed so far. We have studied the rate of
nucleotide substitution over a region of the Xdh gene containing two adjacent
short, constitutively spliced introns, in several species of Drosophila and
related genera. The two introns differ significantly in base composition and
substitution rate, with one intron evolving at least twice as fast as the other.
In addition, the substitution pattern of the introns is positively associated
with that of the surrounding coding regions, evidencing that the molecular
evolution of these introns is impacted by the region in which they are embedded.
The observed differences cannot be attributed to selection acting differently at
the level of the secondary structure of the pre-mRNA. Rather, they are better
accounted for by locally heterogeneous patterns of mutation.
PMID- 10684347
TI - The codon-degeneracy model of molecular evolution.
AB - Mitochondrial genetic codons can be categorized by four patterns of nucleotide
site degeneracy based on varying combinations of twofold- or nondegenerate sites
at first codon positions and twofold- or fourfold-degenerate sites at third codon
positions. Herein, a model of molecular evolution is introduced that uses these
patterns to calculate expected substitution frequencies for each codon position
and substitution type relative to overall number of synonymous or nonsynonymous
substitutions. Regions of the pocket gopher cytochrome oxidase subunit I (COI)
and cytochrome b (cyt-b) genes are analyzed using this model. Chi-square
distributions are used to produce relative goodness-of-fit (GF) scores for
measuring the difference between substitution frequencies predicted by the codon
degeneracy model (CDM), and frequencies inferred using a well-supported
phylogenetic tree of closely related species. The GF scores for expected and
observed synonymous (GF(syn) = 0.429, p = 0.807) and nonsynonymous (GF(ns) =
2.309, p = 0.679) substitution frequencies resulted in a failure to reject the
CDM as a null hypothesis for the molecular evolution of COI and cyt-b in pocket
gophers. Alternative tree topologies and calculations of transition bias for
these data result in higher GF scores.
PMID- 10684348
TI - Neutral and nonneutral mitochondrial genetic variation in deep-sea clams from the
family vesicomyidae.
AB - Nucleotide sequences at two mitochondrial genes from 57 individuals representing
eight species of deep-sea clams (Vesicomyidae) were examined for variation
consistent with the neutral model of molecular evolution. One gene, cytochrome
oxidase subunit I (COI), deviated from the expectations of neutrality by
containing an excess of intraspecific nonsynonymous polymorphism. Additionally,
one species, Calyptogena kilmeri, showed a significant excess of rare
polymorphism specifically at the COI locus. In contrast, a second mitochondrial
gene, the large-subunit 16S ribosomal RNA gene (16S), showed little deviation
from neutrality either between or within species. Together, COI and 16S show no
deviation from neutral expectations by the HKA test, produce congruent
phylogenetic relationships between species, and show correlated numbers of fixed
differences between species and polymorphism within species. These patterns of
both neutral and nonneutral evolution within the mitochondrial genome are most
consistent with a model where intraspecific nonsynonymous polymorphism at COI is
near neutrality. In addition to examining the forces of molecular evolution, we
extend hypotheses about interspecific relationships within this family for
geographical locations previously unexamined by molecular methods including
habitats near the Middle Atlantic, the Aleutian Trench, and Costa Rica.
PMID- 10684349
TI - Concerted evolution of a highly repetitive DNA family in eptatretidae
(Cyclostomata, agnatha) implies specifically differential homogenization and
amplification events in their germ cells.
AB - In eight hagfish species, it is known that chromosome elimination occurs during
early embryogenesis, and some highly repetitive DNA families, restricted to germ
cells, have been isolated. One of these families, "EEEo2," has been isolated as
DNA fragments by restriction enzyme analyses from Eptatretus okinoseanus and E.
cirrhatus. In this study, EEEo2 sequences were isolated from germline DNA in E.
burgeri, Paramyxine sheni, and P. atami using PCR methods. Sequence analysis
revealed that these sequences are intraspecifically homogeneous, except in E.
burgeri, and are interspecifically conserved with heterogeneity. The
intraspecific sequence variability tends to decrease as the copy number
increases. These results indicate that EEEo2 has evolved in a concerted manner.
Moreover, an ancestral repeating motif consisting of triplicate subrepeats was
deduced. These results suggest that EEEo2 arose as an initial amplification of
this subrepeat and has evolved by saltatory replication. Phylogenetic analyses
suggested the possibility that EEEo2 in E. okinoseanus and E. cirrhatus has been
subjected to strong homogenizing forces for concerted evolution, whereas the
force is weak in E. burgeri. In addition, EEEo2 in P. sheni and P. atami appear
to have been incompletely subjected to these forces. Chromosomal in situ
hybridization experiments revealed that EEEo2 sequences were located along almost
their entire length of several heterochromatic chromosomes that are restricted to
germ cells. These chromosomes are disposed to form a secondary association during
the first meiotic metaphases, except in P. sheni. This chromosomal distribution
may promote a concerted mode of sequence evolution in both nonhomologous
chromosomes and homologous chromosomes and reflect the differential driving
forces between species.
PMID- 10684350
TI - Gene conversions may obscure actin gene family relationships.
AB - Phylogenetic hypotheses of muscle actin evolution are significantly different
when a sea urchin is used as a representative echinoderm than when a sea star is
used. While sea urchin muscle actins support an echinoderm-chordate sister
relationship, sea star sequences suggest that echinoderm muscle actins are
convergent with chordate muscle actins. Our results suggest that gene conversion
in the sea star muscle actin may be responsible for these discordant results.
PMID- 10684351
TI - Do pheromone binding proteins converge in amino acid sequence when pheromones
converge?
AB - Convergence in amino acid sequences between proteins can be strong evidence for
selection. Here, I look for evidence of convergence in the amino acid sequences
of pheromone binding protein (PBP) in response to convergence in pheromones. PBPs
are involved in sex pheromone reception by the antennae of male moths. In this
role PBPs may selectively bind pheromone components and experience convergent
selection in response to convergence in pheromone components. However,
examination of the PBPs of the taxa that have converged upon the use of (E)- or
(Z)-11-tetradecenyl acetate as their major pheromone component reveals little
evidence for convergence in the PBPs identified from these taxa. A few sites show
a pattern consistent with convergence or parallelism; however, it cannot be ruled
out that these sites share the ancestral state. Two of these sites fall within
the proposed binding region of PBPs. These results suggest that PBPs either have
not converged in sequence or have converged at very few sites in response to
convergence on the same pheromone component.
PMID- 10684352
TI - Codon usage in plastid genes is correlated with context, position within the
gene, and amino acid content.
AB - Highly expressed plastid genes display codon adaptation, which is defined as a
bias toward a set of codons which are complementary to abundant tRNAs. This type
of adaptation is similar to what is observed in highly expressed Escherichia coli
genes and is probably the result of selection to increase translation efficiency.
In the current work, the codon adaptation of plastid genes is studied with regard
to three specific features that have been observed in E. coli and which may
influence translation efficiency. These features are (1) a relatively low codon
adaptation at the 5' end of highly expressed genes, (2) an influence of
neighboring codons on codon usage at a particular site (codon context), and (3) a
correlation between the level of codon adaptation of a gene and its amino acid
content. All three features are found in plastid genes. First, highly expressed
plastid genes have a noticeable decrease in codon adaptation over the first 10-20
codons. Second, for the twofold degenerate NNY codon groups, highly expressed
genes have an overall bias toward the NNC codon, but this is not observed when
the 3' neighboring base is a G. At these sites highly expressed genes are biased
toward NNT instead of NNC. Third, plastid genes that have higher codon
adaptations also tend to have an increased usage of amino acids with a high G + C
content at the first two codon positions and GNN codons in particular. The
correlation between codon adaptation and amino acid content exists separately for
both cytosolic and membrane proteins and is not related to any obvious functional
property. It is suggested that at certain sites selection discriminates between
nonsynonymous codons based on translational, not functional, differences, with
the result that the amino acid sequence of highly expressed proteins is partially
influenced by selection for increased translation efficiency.
PMID- 10684353
TI - Lack of evidence for cospeciation between retroelements and their hosts.
AB - Some literature is available on cospeciation and on reconstructing the
phylogenetic relationships of retroelements, but relatively little consideration
has been given to whether there is cospeciation between retroelements and their
hosts. Here we address this problem in detail. We conclude that there is no
significant evidence for cospeciation between retroelements and their hosts. This
conclusion was reached by noting that the branching order of the two phylogenies
was no more similar than would be expected by chance.
PMID- 10684354
TI - A probable mixed-function supraoperon in pseudomonas exhibits gene organization
features of both intergenomic conservation and gene shuffling
PMID- 10684355
TI - Pharmacokinetics and tolerance of mycophenolate mofetil in renal transplant
children.
AB - Mycophenolate mofetil (MMF) is a prodrug that is hydrolyzed to the active
immunosuppressant mycophenolic acid (MPA). The drug is now widely prescribed for
adult renal transplant recipients and its use has been extended to pediatric
patients, although pharmacological data in this age group are limited. Nine
pediatric renal transplant recipients received MMF with corticosteroids and
either cyclosporine or tacrolimus a median of 55 months (range 7.5-124 months)
months after transplantation. The pharmacokinetic parameters of MPA and MPA
glucuronide (MPAG) were determined at steady state by high-performance liquid
chromatography after administration of MMF at the oral dose of 494+/-142 mg/m(2)
twice daily. MPA was rapidly absorbed, with a peak concentration at 1.4 h. The
mean plasma concentration of MPA at steady state was 4.7+/-1.3 microg/ml. The
areas under the plasma concentration-time curves (AUCs) over 12 h (between two
administrations) were 57.0+/-15.3 microg.h/ml for MPA and 1,515+/-722 microg.h/ml
for MPAG, and the apparent oral clearance was 11.7+/-7.0 and 0.5+/-0.4 l/h for
MPA and MPAG, respectively. Assuming that the pharmacokinetics of MPA was dose
dependent, the mean concentration at steady state and the AUC for MPA were
calculated for the recommended dosage schedule of 600 mg/m(2) every 12 h and were
6.3+/-2.7 microg/ml and 75.2+/-32.9 microg.h/ml, respectively. The tolerance of
MMF was studied prospectively with a follow-up of 1.1+/-0.2 years.
Gastrointestinal disorders requiring dosage reduction or discontinuation of
therapy, observed in five of nine patients, occurred at an incidence higher than
expected from adult data. Our results suggest that the dose of 600 mg/m(2) every
12 h extrapolated from adult data for use in pediatric patients would be
associated with plasma levels and AUCs higher than expected and may be associated
with a higher incidence of side-effects, primarily gastrointestinal.
PMID- 10684356
TI - Pharmacokinetics of mycophenolate mofetil are influenced by concomitant
immunosuppression.
AB - The recommended dosage for mycophenolate mofetil (MMF) in combination with
cyclosporin (CyA) for pediatric kidney transplant recipients is 600 mg/m(2) twice
daily (b.i.d.). We recently published pharmacokinetic (PK) profiles of MMF in
combination with tacrolimus (FK506): in order to keep the mycophenolic acid (MPA)
pre-dose trough concentration between 2 and 5 microg/ml and to avoid side
effects, mean MMF doses were reduced to 300 mg/m(2) b.i.d. In order to
investigate whether this striking difference was due to alterations of MPA
clearance by CyA or FK506, we analyzed PK profiles from 13 patients who received
MMF without CyA or FK506, and compared these data with 14 patients who received a
combination of MMF and FK506 and 15 patients who received MMF and CyA. Mean area
under the curve (AUC) in all PK profiles was 61.9+/-23.8 microgxh/ml. Although
the AUCs did not differ between the groups, the dose per square meter was
significantly lower in patients receiving concomitant FK506 compared with CyA,
and the dose-normalized AUC was significantly higher. The MMF doses were 1,158+/
301 mg/m(2) per day in the CyA group, 555+/-289 mg/m(2) per day in the tacrolimus
group, and 866+/-401 mg/m(2) per day in the group without concomitant calcineurin
inhibitor treatment. The apparent clearance of MPA is reduced in combination with
tacrolimus. The reason for this remains unknown. There was a trend towards lower
dose-normalized AUCs in the CyA group compared with the group without calcineurin
inhibitor treatment. We conclude that concomitant medication alters the clearance
of MPA. It is noteworthy that there was substantial interindividual variation,
despite the rather marked differences between the groups, and therefore we
recommend starting MMF in combination with CyA at a dose of 600 mg/m(2) b.i.d.,
in combination with tacrolimus at a dose of 300 mg/m(2) b.i.d., and without a
calcineurin inhibitor at a dose of 500 mg/m(2) b.i.d., and adjusting doses using
therapeutic drug monitoring of MPA.
PMID- 10684357
TI - Risk factors for hyperlipidemia in long-term pediatric renal transplant
recipients.
AB - Hyperlipidemia (HL) is a common problem in adult renal transplant (TP)
recipients, contributing to an increased risk of cardiovascular disease and
chronic TP nephropathy. There are multiple causes of HL post renal TP in adult
patients, including pre TP HL, immunosuppressive agents, renal dysfunction,
hypoalbuminemia secondary to nephrotic syndrome, obesity, and conditions that
lead to end-stage renal disease (ESRD). We evaluated the incidence and risk
factors of HL in 62 pediatric renal TP recipients (15.4+/-4.2 years, range-3.0
22.3 years) with long-term (6.7+/-3.1 years) functioning [glomerular filtration
rate (GFR) 66.7+/-23.2 ml/min per 1.73 m(2)] allografts. The mean serum
cholesterol (C) level was 205. 5+/-43.6 mg/dl. Thirty-two patients (51.6%)
exhibited elevated serum C levels. The mean serum triglyceride (TG) level was
157.3+/-88.4 mg/dl. Serum TG levels were elevated in 32 patients (51.6%). In
patients with elevated serum levels of either C or TG, the mean low-density
lipoprotein level (LDL) was 138.6+/-44.1 mg/dl (normal <130 mg/dl) and the high
density lipoprotein (HDL) level 54.6+/-15.9 mg/dl (normal>34 mg/dl). Of those
patients studied, 45.5% had high LDL levels, whereas 9.1% exhibited low HDL
levels. The two risk factors for elevated serum C levels in our patient
population were pre-TP HL and increased years since TP. The only risk factor for
elevated serum TG levels was reduced GFR. A family history of HL had a
significant deleterious impact upon serum levels of C (P=0.01), but did not
affect serum TG levels (P=0.7). Years on dialysis prior to TP, history of prior
TP, gender, body mass index, and disease leading to ESRD had no influence upon
the development of post-TP HL. We conclude that post-renal TP HL is a significant
problem in pediatric renal TP recipients.
PMID- 10684358
TI - Fatal disseminated Nocardia farcinica infection in a renal transplant recipient.
AB - Six years after a renal cadaver transplant, a 20-year-old girl developed multiple
painful cutaneous abscesses and bilateral pneumonia secondary to Nocardia
farcinica infection. Despite broad in vitro sensitivity to several antibiotic
agents and aggressive medical treatment, the patient failed to respond and died
after 10 weeks of therapy. We conclude that Nocardia farcinica is a very
aggressive organism in immunocompromised patients and is often resistant to
antimicrobial agents.
PMID- 10684359
TI - Reduction of peritonitis with the rectus abdominis muscle flap in a CAPD patient.
AB - An adolescent maintained on continuous ambulatory peritoneal dialysis (CAPD) for
8 years had relapsing peritonitis involving peritoneal catheter tunnel
infections. We attempted catheter removal and replacement simultaneously, with
the catheter covered cylindrically by a rectus abdominis muscle flap to prevent
recurrent tunnel infections. During 3 years of follow-up, there have been no
episodes of peritonitis involving tunnel infection. Our modified insertion
technique can eradicate tunnel infection, thus reducing peritonitis.
PMID- 10684360
TI - Mutational analysis of COL4A5 gene in Korean Alport syndrome.
AB - Mutational analysis of the COL4A5 gene in X-linked Alport syndrome (AS) requires
an expensive and time-consuming procedure with a detection rate of 50%, at best.
There have been three multicenter collaborative studies of mutation analysis in
the COL4A5 gene using systematic screening of entire coding regions of the gene.
This is a similar study executed in a single center in Korea. Twenty-five
unrelated Korean patients with AS in whom the diagnosis was confirmed
pathologically were included in the study. By systematic screening of all 51
exons of the gene using polymerase chain reaction/single-strand conformation
polymorphism analysis, ten mutations were detected in 10 unrelated patients.
These included one medium-sized deletion involving exon 49-51, one single base
pair deletion, one nonsense point mutation, one splice site mutation, and six
missense point mutations. Of the six missense mutations, four involved a glycine
residue and disrupted the Gly-X-Y repeats in the collagenous domain. The overall
detection rate of mutations was 40%. Although DNA analysis in AS is currently not
applicable to routine clinical diagnosis due to several practical and technical
problems, it is likely to replace morphological diagnosis in the near future.
PMID- 10684361
TI - Acidosis and weight loss are induced by cyclosporin A in uninephrectomized rats.
AB - The effects of cyclosporin A (CyA, 50 mg/kg body weight) or its commercial
vehicle (cremophor) on the acid-base regulation of uninephrectomized rats were
assessed for 7 days and in non-nephrectomized rats for 15 days. CyA induced a
marked systemic acidosis, accompanied by decreases in blood PCO(2) and plasma
bicarbonate. Untreated uninephrectomized rats did not show the acidosis. In CyA
treated rats the urine pH decreased (control 6. 65+/-0.06 vs. CyA 6.18+/-0.08;
P<0.01) as well as urinary bicarbonate (non-nephrectomized rats 7.50+/-1.88 mM
vs. uninephrectomy plus CyA 0.75+/- 0.06 mM; P<0.01), suggesting partial renal
compensation of systemic acidosis. Titratable acidity increased in CyA-treated
rats (control 21.6+/-1.2 vs. CyA 63.3+/-12.0 microEq/l; P<0.001). Phosphate,
glucose, and osmolar clearances were not significantly altered in non
nephrectomized rats treated with CyA for 15 days. There was a striking decrease
in body weight in CyA-treated rats (control 274.0+/-3.8 vs. CyA 225.0+/-5.1 g;
P<0. 01), but compensatory growth of the remaining kidney was not prevented by
this drug or by its vehicle. In summary, CyA induced a severe metabolic acidosis
in uninephrectomized rats that was not compensated by the remaining kidney, in
spite of the well-preserved compensatory weight gain of this organ. Loss of body
weight was significant in CyA-treated animals.
PMID- 10684362
TI - Phospholipase A(2) activity, heat shock protein, and superoxide dismutase in rat
remnant kidney.
AB - Male Sprague-Dawley rats (150-200 g) were randomly assigned to sham operation
(n=6) or 5/6 nephrectomy (n=12) procedures. Two weeks after the completion of the
5/6 nephrectomy, these animals were again randomly assigned to two groups: non
treatment or treatment with vitamin E supplementation at 200 IU/kg chow. Two
weeks later, all animals were sacrificed and the kidneys harvested. The secretory
phospholipase A(2) (PLA(2)) activity was elevated (150%) in the untreated remnant
kidney but returned to sham values in the vitamin E-treated kidneys. The
cytoprotective heat shock protein (HSP70) and the intracellular antioxidant
superoxide dismutase (MnSOD, Cu/ZnSOD) were similar in sham, remnant, and vitamin
E-treated remnant kidneys. We conclude that the sudden reduction of renal mass
secondary to the 5/6 nephrectomy procedure stimulates PLA(2) activity but not
HSP70, MnSOD, or Cu/ZnSOD. This increased activity of PLA(2) in the remnant
kidney returned to sham values after vitamin E treatment. The intrinsic cellular
antioxidant enzymes, MnSOD, Cu/ZnSOD, as well as the cytoprotective heat shock
protein HSP70, showed no significant changes in either vitamin E-treated or
untreated kidneys compared with sham. These data are suggestive that the
elevation of PLA(2) is a specific and localized response to the sudden reduction
of renal mass.
PMID- 10684363
TI - Idiopathic collapsing glomerulopathy in children.
AB - Idiopathic collapsing glomerulopathy (ICG) is a clinically and pathologically
distinct variant of focal segmental glomerulosclerosis, characterized clinically
by rapid progression of renal insufficiency, a male and African-American racial
predominance, and pathologically by segmental glomerular collapse, visceral
epithelial cell hypertrophy and hyperplasia, and the absence of endothelial
tubuloreticular inclusions. Pathologically similar lesions have been reported in
adult and pediatric patients with human immunodeficiency virus (HIV) infection
and/or intravenous (IV) drug abuse. Most patients with ICG who have been reported
in the literature are adults. Six children with ICG were retrospectively
identified (two from East Carolina University, four from University of North
Carolina-Chapel Hill). Clinical data and renal biopsy findings were reviewed for
all patients. All six patients were male; five African-American and one Hispanic.
Ages ranged from 2 to 17 years (mean 12 years). Steroid-resistant nephrotic
syndrome was the presenting clinical finding. Average 24-h urine protein
excretion was 6.3 g (range 3.2-15 g). Five patients were serologically negative
for HIV infection (one patient not tested) and none had a history of IV drug
abuse or known HIV risk factors. Progression to end-stage renal insufficiency in
two patients within 1 year of biopsy required renal transplantation, and within 1
month of biopsy one patient required dialysis. We report a series of pediatric
patients with ICG, an aggressive variant of focal segmental glomerulosclerosis.
ICG in children is similar clinically and pathologically to this disease in adult
patients.
PMID- 10684365
TI - Bartter syndrome in a neonate: early treatment with indomethacin.
AB - The neonatal form of Bartter syndrome is characterized by intrauterine onset of
polyuria leading to severe polyhydramnios. We report a patient with the early
onset of the syndrome and a similar history in a previous sibling who died in
early neonatal life. The patient is a female product of 33 weeks of gestation
complicated by severe polyhydramnios. Her birth weight was 2,100 g. Polyuria led
to severe dehydration on the 3rd day of life. Laboratory studies showed
hypokalemia, hyponatremia, and elevated plasma levels of renin and aldosterone.
Hypercalciuria was associated with echographic evidence of nephrocalcinosis.
Indomethacin therapy resulted in a significant reduction in urine volume and
correction of biochemical abnormalities. Growth and development are satisfactory
after 4 years of indomethacin therapy, but nephrocalcinosis remains unchanged.
PMID- 10684364
TI - Hemostatic problems and thromboembolic complications in nephrotic children.
AB - A hypercoagulable state and the risk of thromboembolism in both arterial and
venous circulation is a relatively frequent and serious feature of nephrotic
syndrome (NS) in children and adults. The aim of this study was to evaluate the
coagulation states of children with NS before and after corticosteroid (CS)
therapy and to compare the results with a healthy control group. The first group
consisted of 49 nephrotic children (30 boys and 19 girls) with a mean age of 6.
5+/-4.9 years (range 1-16 years). The control group included 17 healthy children
(9 boys and 8 girls). At the time of admission, all patients were evaluated for
the presence of clinical thromboembolism, hematological and biochemical
indicators of a hypercoagulative state, and renal disease. This was repeated
after CS treatment. Deep vein thrombosis was observed in 2 nephrotic patients who
had very low plasma antithrombin III (AT III) levels and fibrinogen levels above
750 mg/dl. Thus, the prevalence of thromboembolism was 4% in our pediatric
nephrotic population. The mean AT III level of the study group was 68.2+/-23.4%
at the onset of the disease, which was significantly lower than the level of the
control group (84.0+/-7. 6%). Plasma AT III levels increased to 74.4+/-15.3%
after CS treatment, which correlated with the serum albumin levels. However,
there was no correlation with urinary protein excretion. Protein C levels were
higher than controls during all stages of the disease in both steroid-responsive
and -unresponsive patients. The mean protein S level was similar in both groups.
Plasma fibrinogen and cholesterol levels were significantly higher in the study
group but decreased to within normal limits with remission. Our study suggests
that thromboembolic complications are not infrequent in children with NS, and may
be related to low plasma AT III and albumin and high fibrinogen and cholesterol
levels.
PMID- 10684366
TI - Vesicoureteric reflux associated with renal dysplasia in the Wolf-Hirschhorn
syndrome.
AB - Wolf-Hirschhorn syndrome (WHS) is caused by a partial deletion of the short arm
of chromosome 4 (4p16.3) and is characterized by severe pre- and postnatal growth
retardation, developmental delay, and multiple congenital anomalies, including
malformations of the urogenital system. We describe the renal and urinary tract
phenotype in a series of six children with WHS. Vesicoureteric reflux was present
in four of our six patients (5 of 10 ureters), an abnormality not previously
reported in WHS.
PMID- 10684367
TI - A new variant of apolipoprotein E (apo E Maebashi) in lipoprotein glomerulopathy.
AB - We have previously reported an 8-year-old girl with lipoprotein glomerulopathy.
Assessment of serum apolipoprotein E (apo E) in this patient showed a discrepancy
between phenotype and genotype, suggesting that she may have a variant of apo E.
The present report concerns our analysis of DNA sequences of the apo E gene in
the patient: nine base pairs were found to be deleted from exon 4. This mutation
would appear to encode a new apo E variant lacking three amino acids. This
variant may be associated with the pathogenesis of lipoprotein glomerulopathy.
PMID- 10684368
TI - Gene expression after intrarenal injection of plasmid DNA in the rat.
AB - Effective gene therapy requires efficient delivery and expression of the
necessary genetic information to the target tissue. We demonstrate here that
plasmid DNA, injected as naked, uncomplexed DNA into the cortical region of rat
kidney, or intravenously, is localized and expressed in the kidney. The plasmid
pRSVZ contained the Rous sarcoma virus promoter and a reporter gene, the beta
galactosidase gene, derived from bacteria. The beta-galactosidase gene hydrolyzes
the artificial substrate X-gal to produce an intense blue color in cells that
have taken up and expressed the plasmid genes. We have used X-gal staining and
Western blotting to study plasmid gene expression 1, 4, and 8 days and 6 months
after intrarenal injection of 50 microg of plasmid DNA and at 1 and 4 days after
intravenous injection. Expression was apparent in the kidneys and several other
tissues 24 h after injection and persisted for at least 8 days; expressed
proteins could still be detected in the injected kidney 6 months later. These
observations were corroborated by use of a plasmid, pEGFP-Puro, harboring the
cytomegalovirus promoter in conjunction with a different reporter gene, the green
fluorescent protein (GFP). Histological localization and Western blotting
analysis of GFP expression after intrarenal injection of pEGFP-Puro paralleled
results obtained with the plasmid pRSVZ. Our findings support the suggestion that
intrarenal or intravenous injection of naked plasmid DNA may be an effective
means of delivering therapeutic genes to the kidney and several other tissues.
PMID- 10684369
TI - Treatment of lupus nephritis in children.
AB - In children, systemic lupus erythematosus (SLE) is often more severe than in
adults. Renal disease is very common in SLE, with clinical symptoms of renal
involvement occurring in 30%-70% of patients. In the absence of appropriate
treatment the child may die from the disease or progress rapidly to renal
failure. However, aggressive treatment regimens, in particular corticosteroids,
carry the risk of growth retardation, accelerated atherosclerosis, and severe
infectious complications. Lupus nephritis is classified into six groups depending
on the severity of the histological lesions. The most-appropriate treatment for
optimal efficacy with minimal side-effects depends on the disease severity. Mild
lesions (class I or II) require only careful follow-up to identify any disease
progression. Patients with class III nephropathy (focal and segmental
glomerulonephritis) may have mild clinical symptoms, in which case no specific
therapy is indicated, or more-severe symptoms of the nephrotic syndrome,
hypertension, and sometimes moderate renal insufficiency. These patients require
the same aggressive therapy as those with class IV disease (diffuse proliferative
glomerulonephritis). Our current protocol starts with three methylprednisolone
pulses followed by 1.5 mg/kg per day oral prednisone and six monthly pulses of
cyclophosphamide. After a second renal biopsy the patient may be maintained on
azathioprine while the prednisone dosage is slowly tapered. In children with
milder disease we use lower doses of oral prednisone (1-1.5 mg/kg per day).
Patients with membranous glomerulonephritis (class V) require no specific therapy
if they have pure membranous nephropathy, but require aggressive therapy if they
have the nephrotic syndrome. In those patients who progress to end-stage renal
disease, clinical and serological remission is common and renal transplantation
can be performed, as recurrence in the transplant is very rare.
PMID- 10684370
TI - Fetal therapy for obstructive uropathy: past, present.future?
AB - Antenatal treatment of obstructive uropathy, although widely performed, remains
controversial. An overview of prenatal therapy for obstructive uropathy, the
limitations of the early published experience, advances of recent years, and
future directions for treatment are reviewed. The clinical approach and outcomes
of the Fetal Treatment Program of Hutzel Hospital and Wayne State University are
presented. Patient selection for antenatal treatment is based on the existence of
a significant threat of neonatal death due to pulmonary hypoplasia, pending
exclusion criteria such as anatomical structural anomalies and chromosomal
defects. Ultrasonography, karyotyping, and sequential urinary electrolyte
analysis are essential. Current treatment involves the placement under ultrasonic
guidance of a Rodeck vesicoamniotic shunt. Recent technical advances include the
use of amnioinfusion for fetal visualization, temporary fetal paralysis, routine
antibiotics, and more-precise catheter placement. The establishment of
standardized short- and long-term outcome measures and the documentation of fetal
and maternal complications are in progress. Procedural refinement, development of
fetoscopic techniques and equipment, identification of urinary markers to aid
patient selection, and the collection of multicenter outcome data will assist the
future management of prenatally detected obstructive uropathy.
PMID- 10684371
TI - Ask the expert.
PMID- 10684372
TI - IPNA newsletter
PMID- 10684373
TI - Histologic examination of bone marrow core biopsy specimens has limited value in
the diagnosis of mycobacterial and fungal infections in patients with the
acquired immunodeficiency syndrome.
AB - Bone marrow cultures and biopsy specimens are commonly obtained to rule out
disseminated infections, especially in persons with the acquired immunodeficiency
syndrome (AIDS) and cytopenias. Using culture as the gold standard, we reviewed
130 consecutive bone marrow cores obtained from 114 AIDS patients along with
results of concurrent blood and/or bone marrow aspirate cultures to determine the
usefulness of histologic examination for diagnosis of mycobacterial and fungal
infections. We also compared the ability of Ziehl-Neelsen, auramine-rhodamine
(AR), polyclonal antibody to Mycobacterium bovis (Ab), and Gomori's methenamine
silver staining to detect infections. Twenty-seven patients had mycobacterial
infection (25 Mycobacterium avium-intracellulare complex cases and two
Mycobacterium tuberculosis cases) detected by blood and/or bone marrow cultures.
The maximum sensitivity of histology was 50% when the auramine-rhodamine stain
and the polyclonal antibody to M bovis were used in combination. The single best
stain was auramine-rhodamine, with a sensitivity of 44%, followed by the
polyclonal antibody to M bovis (35%). Granulomas were observed in nine cases of
mycobacterial infection and did not correlate with the presence of stainable
organisms. Of seven patients with positive fungal cultures of bone marrow, four
had granulomas and a positive Gomori's methenamine silver stain, one had only a
positive stain, and two had neither granulomas nor a diagnostic stain. Overall,
granulomas were not sensitive for the detection of infections when culture-proven
mycobacterial and fungal cases were evaluated together. We conclude that bone
marrow examination has a limited value in the routine evaluation of common
opportunistic infections in AIDS patients and recommend that less-invasive tests,
such as blood cultures, be obtained initially in most circumstances.
PMID- 10684374
TI - Epstein-Barr virus in squamous carcinoma of the anterior nasal cavity.
AB - Squamous carcinoma is the most common malignancy of the head and neck, but it
rarely occurs in the nasal vestibule. Epstein-Barr virus (EBV) has been detected
in and is causally linked to various head and neck tumors, particularly
nasopharyngeal carcinoma. The possible role of EBV in squamous carcinoma of the
anterior nasal cavity, particularly of the nasal vestibule, has not been
previously investigated. Histologic sections from 17 patients with nasal
vestibular squamous carcinoma were examined. Material for EBV detection by
immunohistochemistry and by in situ hybridization was available in 15 of the 17
cases. The study group consisted of eight men and nine women ranging in age from
40 to 82 years (mean age, 64 years). None of the patients was of Asian descent.
The squamous carcinomas were graded as well differentiated (one case), moderately
differentiated (11 cases), and poorly differentiated (five cases). Fourteen
patients were smokers; the history of smoking ranged from 20 to 60 pack-years.
Treatment modalities included surgical resection, radiation, chemotherapy, or a
combined approach. The clinical follow-up periods ranged from 7 months to 16
years. Three patients developed metastases, one of whom died of disease after 1
year. Epstein-Barr virus was not detected in any of the 15 of 17 cases tested by
either immunohistochemistry or by in situ hybridization. Squamous carcinoma of
the nasal vestibule is an uncommon cancer that is not causally related to EBV.
PMID- 10684375
TI - Prognostic significance of nuclear DNA content in chondrosarcoma.
AB - Chondrosarcoma is the second most frequent primary malignant tumor of bone. Many
of these tumors represent histopathologic borderline cases. In this study, DNA
ploidy status, 2c deviation index (2cDI), and DNA malignancy grade (DNA-MG; based
on the variation of nuclear DNA content of tumor cells around the normal DNA [2c]
peak) were examined for their diagnostic and prognostic value in comparison with
conventional histopathologic grading. Twenty-two paraffin-embedded samples were
available for histopathologic investigation and for quantitative cytophotometric
DNA determination of Feulgen-stained nuclei. Clinicopathologic parameters and
prognosis were analyzed over a maximum follow-up period of 252 months. Nineteen
of 22 (86%) chondrosarcomas showed aneuploid DNA content. 2cDI (r =.58, P <.01)
and DNA-MG (r =.58; P <.01) correlate with the histopathologic grading.
Significant correlation between the 2cDI (P <.01) and DNA-MG (P <.025) and the
overall survival was found. Ploidy did not influence the overall survival rate.
In metastasis-free patients, the 2cDI and DNA-MG gave better prognostic
information than conventional histopathologic grading. When patients developed
metastasis, however, histopathologic grading was the prognostic parameter of
choice. Cytometric DNA measurement provide additional objective information
regarding the diagnosis and prognosis of chondrosarcomas, even more than that
obtained by conventional histopathologic grading, and may be helpful in planning
the treatment.
PMID- 10684376
TI - Fine-needle aspiration of granulocytic sarcomas: a morphologic and
immunophenotypic study of seven cases.
AB - Granulocytic sarcoma is an uncommon extramedullary, solid tumor of myeloid cells.
Only rarely has this entity been diagnosed by fine-needle aspiration (FNA)
cytology. This report encompasses the cytologic findings of FNAs from seven
patients with granulocytic sarcomas, including four male and three female
patients with a mean age of 52 years (range, 12 to 77 years). The aspirates were
obtained from skin or subcutaneous tissue (four cases), testis (one case),
posterior ileum (one case), lymph node (one case), and abdominal washing (one
case). Morphology of the aspirates varied from well-differentiated to poorly
differentiated cells showing little or no evidence of myeloid differentiation.
Thorough search for evidence of myeloid differentiation and a high index of
suspicion of granulocytic sarcoma are of paramount importance. In three cases,
flow cytometric and immunocytochemical studies were applied to the FNA materials
to confirm the myeloid lineage of the cells and the diagnosis. In the other four
cases more than one site was involved by the tumor; once the diagnosis of
granulocytic sarcoma was established with a biopsy, the FNA sufficed to confirm
the diagnosis at another location. This study demonstrates that FNA cytology in
conjunction with appropriate immunophenotyping can provide an accurate diagnosis
of granulocytic sarcoma. Fine-needle aspiration can reduce the need for surgical
intervention when combined with immunophenotypic studies and when additional
anatomic sites are involved.
PMID- 10684377
TI - Isolated Langerhans cell histiocytosis of the thyroid: a report of two cases with
nuclear imaging-pathologic correlation.
AB - We describe two cases of isolated langerhans cell histiocytosis (LCH) of the
thyroid gland, one of which was found in conjunction with an incidental papillary
carcinoma. The first case was that of a 43-year-old man who presented with a 1-
to 2-cm nodule within the left lobe of the thyroid. Fine-needle aspiration
cytology revealed atypical cells with convoluted nuclei in a background of
eosinophils and lymphocytes. The findings prompted a recommendation for excision
secondary to the high suspicion of a hematologic malignancy. Histologic sections
demonstrated LCH in association with a small focus of papillary carcinoma. The
second case involved a 43-year-old woman who presented with a 1.8-cm nodule
within the right lobe of the thyroid. Fine-needle aspiration in this case
demonstrated abundant hemosiderin-laden macrophages, occasional lymphocytes, and
a single benign sheet of follicular cells. No eosinophils were seen; however, a
single group of atypical histiocytic cells with cleaved nuclei was noted. The
nodule was subsequently resected. Histologic examination demonstrated LCH in
association with follicular nodular hyperplasia with cystic degeneration.
Immunohistochemical studies were performed in both cases, revealing CD1a and S100
immunoreactivity in the Langerhans' cells. Although LCH may occur as a
manifestation of systemic disease, its occurrence as an isolated finding in the
thyroid is rare. Its occurrence in association with papillary carcinoma of the
thyroid is even more uncommon. We present two cases of isolated LCH of the
thyroid, one of which was found in association with papillary carcinoma of the
thyroid. The cytologic, histologic, immunohistochemical, and radiologic features
are described in each case. The ultrastructural findings from the first case are
also presented.
PMID- 10684379
TI - Ossifying well-differentiated Sertoli-Leydig cell tumor of the ovary.
AB - A unique case of an ovarian sex cord-stromal tumor occurring in a pregnant 20
year-old is described. The tumor showed central ossification on macroscopic
examination. Microscopically, cords and nests of Sertoli cells were identified,
mostly away from the abundant central hyalinization, calcification, and
ossification. A small number of Leydig cells were present, with isolated Reinke
crystals. The presence of these cells could reflect luteinized stromal cells
secondary to pregnancy. The Sertoli cells were dominant and the
calcified/ossified areas were at the center of a dominant Sertoli nodule. This
degree of ossification has never been reported in either ovarian Sertoli tumors
or well-differentiated Sertoli-Leydig tumors. Calcifying Sertoli cells neoplasms
have been described in the testis, but this case appears to be the first
description of a case with similar features in the ovary.
PMID- 10684378
TI - Endometrioid carcinoma arising in pericecal endometriosis clinically mimicking
Crohn's disease.
AB - A case of endometrioid carcinoma arising in pericecal endometriosis that
clinically and radiologically mimicked Crohn's disease is presented. After
developing several complications of steroid therapy for presumed Crohn's disease,
a 48-year-old woman developed intestinal obstruction and underwent a right
hemicolectomy. A pericecal mass composed of endometriosis and endometrioid
carcinoma and a locally metastatic ileal carcinoid tumor were resected. The
patient recovered fully and is clinically free of tumor at 36 months. The
pertinent literature is reviewed and the etiologic, therapeutic, and prognostic
implications of this case are discussed.
PMID- 10684380
TI - A report of mesothelial/monocytic incidental cardiac excrescences and a
literature review.
AB - We report the case of a rare cardiac lesion, mesothelial/monocytic incidental
cardiac excrescences, and also provide a review of the literature. Diagnosis of
this entity was based on both its unique morphologic features and
imunohistochemical stains. Cytokeratin positivity confirmed the epithelial
component, mesothelial cells, in the lesion. Positive staining of CD68 in the
monocytic-appearing cells revealed the histiocytic nature of the second component
of this lesion. Differential diagnoses are discussed. This report emphasizes the
diagnostic dilemma encountered with this unusual entity and the possibility of
misdiagnosing the epithelial portion as a metastatic lesion or vice versa.
PMID- 10684381
TI - A simple yet effective technique to improve laboratory safety for the grossing of
large surgical specimens.
AB - In this article we describe a simple technique to avoid accidential needle stick
injuries while grossing large specimens. Rubber bands instead of needles and
Plexiglas instead of wax board is used to eliminate needle stick injuries. This
method is quite simple and imprints of rubber bands do not interfere with gross
anatomy of the specimen.
PMID- 10684382
TI - The pathology of acute appendicitis.
AB - Although acute appendicitis is frequent, it is subject to common misconceptions.
Furthermore, there is little good evidence to support some of our beliefs. This
report reviews the role of the anatomic pathologist in diagnosis when acute
appendicitis is suspected clinically and discusses what is known of its
pathology. The conclusions that can be legitimately drawn from the literature are
emphasized. A classification is proposed that incorporates intraluminal
inflammation, acute mucosal inflammation, acute mucosal and submucosal
inflammation, suppurative (phlegmonous) appendicitis, gangrenous appendicitis,
and periappendicitis, and the significance of each of these diagnoses is
discussed. The etiology and pathogenesis of acute appendicitis is reviewed.
Contrary to popular belief, the best evidence indicates that obstruction is
unlikely to be the primary cause, at least in the majority of cases. Ancillary
techniques in the diagnosis of appendicitis, including laparoscopy and peritoneal
aspiration cytology, are discussed.
PMID- 10684384
TI - Local lymph node assay: validation assessment for regulatory purposes.
AB - For the prediction of skin sensitization potential of substances, the murine
local lymph node assay (LLNA) is an alternative to the widely used guinea pig
tests. For more than 10 years, this method has undergone extensive development,
evaluation, and validation. In this review, the validation status of the LLNA is
considered, specifically with regard to its use for regulatory identification of
skin sensitization hazards. The LLNA is a method for the predictive
identification of chemicals that have a potential to cause skin sensitization.
Activity is measured as a function of lymph node cell proliferative responses
stimulated by topical application of test chemicals. The LLNA has successfully
passed all reasonable validation stages. It provides a reliable and relevant
source of predictive skin sensitization data, which unlike results from guinea
pig tests, are reproducible from laboratory to laboratory. In summary, the LLNA
is now ready for acceptance as a viable and complete alternative to traditional
methods, offering a substantial reduction in animal numbers and refinement
opportunities without compromising the standards for the identification of
important skin sensitizers.
PMID- 10684385
TI - Skin aging and photoaging: the role of DNA damage and repair.
AB - Both genetic (intrinsic) and environmental (extrinsic) factors contribute to the
phenotypic changes in cutaneous aging. However, only recently have the underlying
molecular mechanisms involved in these changes been elucidated. DNA damage to
both genomic and mitochondrial DNA and subsequent DNA repair contribute greatly
to age-associated skin changes and carcinogenesis. Better understanding of these
intricate, interwoven mechanisms involved in DNA damage and repair might help to
develop new strategies in preventing and treating changes of intrinsic skin aging
and photoaging, improving skin appearance and reducing the risk of skin cancer.
PMID- 10684386
TI - Textile dermatitis in Israel: a retrospective study.
AB - BACKGROUND: The diagnosis of contact dermatitis caused by clothing may be
difficult because of its clinical polymorphism. Data in the literature suggest
that textile dermatitis is more common than previously thought. OBJECTIVE: Our
purpose was to study our patients suspected of having textile contact dermatitis
from 1991 to 1997. METHODS: The records of the patients with positive reactions
to allergens from the Textile Colors and Finish series in 3 contact dermatitis
clinics were reviewed. All the patients were clinically evaluated and patch
tested with the European Standard series and the Textile Colors and Finish series
(Chemotechnique Diagnostics, Malmo, Sweden). RESULTS: Twenty-two of the 55
patients (40%) had positive patch tests to the textile dye allergens. Four of
them had occupationally related textile dermatitis. The most frequent allergens
were Disperse Blue 124, Disperse Blue 85, Disperse Red 17, and Disperse Blue 106.
Erythematosquamous lesions were the most common forms of textile dermatitis
(56%), followed by pustular lesion (16%) and hyperpigmented patches (8%).
CONCLUSIONS: The relatively high percentage of positive results (40%) was
attributable to the selected cohort of patients. In our series, positive
reactions to the allergens Disperse Blue 124, 85, and 106 were common findings.
Clinically, pustular allergic contact dermatitis, triggered by textile dyes was
observed along with the more frequent erythematosquamous clinical form.
PMID- 10684387
TI - Disperse blue dyes 106 and 124 are common causes of textile dermatitis and should
serve as screening allergens for this condition.
AB - BACKGROUND: Textile dye dermatitis is frequently undiagnosed because clinical
awareness is low and because of the absence of good screening allergens in
standard patch test series for this type of contact dermatitis. OBJECTIVES: To
determine the incidence of textile dye allergy in patients with problematic
eczemas evaluated at a contact dermatitis clinic, and to determine the incidence
of allergic contact dermatitis to diperse blue dyes in these patients. METHODS:
We conducted a retrospective study of 788 patients who were patch tested to
either the North American Contact Dermatitis Group (NACDG) Standard Series or the
European Standard Series, in addition to other relevant series. The
Chemotechnique textile series was utilized in 271 patients (28%). RESULTS: Forty
patients reacted positively to 1 or more textile dyes, the majority reacting
positively to Disperse Blue 106 (33 of 40; 82.5%) and to Disperse Blue 124 (32 of
40; 80%). Ten of 11 tested patients reacted to their own clothing, 9 of whom
reacted to the blue/black 100% acetate or 100% polyester liners in their
garments. CONCLUSIONS: Textile dye allergy is more common than previously
reported. It can cause marked dermatitis and widespread autoeczematization
reactions. The most frequent allergens are Disperse Blue 106 and 124, which are
frequently found in the 100% acetate and 100% polyester liners of women's
clothing. We recommend that Disperse Blue 106 or 124 serve as the screening
allergen for textile dye dermatitis.
PMID- 10684388
TI - Cross-reactivity patterns of cobalt and nickel studied with repeated open
applications (ROATS) to the skin of guinea pigs.
AB - BACKGROUND: The relevance of patch-test reactivity to chemicals on cross
challenge is hard to state, but it is generally assumed that the patient might
risk a relapse of contact dermatitis when exposed to the cross-reacting
compound(s). OBJECTIVE: To study relevance by using the repeated open application
test (ROAT) and applying the inducing allergen cobalt chloride (CoCl(2)) or
nickel sulfate (NiSO(4)) as well as the possibly cross-reacting compound (NiSO(4)
or CoCl(2)) topically to guinea pigs. METHOD: Animals were induced according to
the guinea pig maximization test (GPMT) method, patch tested and then treated for
10 days using ROATs. Sensitivity thresholds were determined with serial dilution
tests. RESULTS: Guinea pigs induced with CoCl(2) reacted in patch testing (100%)
and in ROATs to CoCl(2) (93%) but not to NiSO(4). Animals induced with NiSO(4)
reacted in patch testing to NiSO(4) (100%) but not to CoCl(2), and in the ROATs
to NiSO(4) (41%) and less to CoCl(2). CONCLUSIONS: Our results support the
assumption that the concomitant patch test reactivity is due to multiple
sensitizations rather than cross-reactivity. We previously found that animals
induced with palladium chloride (PdCl(2)) also reacted to NiSO(4) on patch
testing but not in the ROATs, indicating that the results from patch testing
might overestimate the risk of a relapse. ROATs in patients with solitary and/or
concomitant sensitivity to CoCl(2), NiSO(4) or PdCl(2) are desirable.
PMID- 10684389
TI - Symptoms and signs reported during patch testing.
AB - BACKGROUND: In a pilot questionnaire study, there was a high frequency of
subjective complaints and distant skin reactions during patch testing as reported
at the day of test reading, particularly in female patients. OBJECTIVE: To
document in a controlled study possible side-effects of a generalized nature
occurring during the test procedure. METHODS: A questionnaire study on symptoms
and signs reported at application and at reading of standard patch tests was
conducted with 401 patients, with the patients serving as their own controls.
RESULTS: An eczematous flare-up during patch testing was observed in 3.7% of the
patients. There were plenty of different symptoms of malaise but, with one
exception (itch on the back), the number of symptoms tended to be less on the day
of reading than on the day of application of the tests. This held true also for
itch occurring in the patients' dermatitis. There was no statistical correlation
between symptoms and signs on the one hand and positive patch tests on the other.
CONCLUSION: Distant skin reactions and impairment of general health occurring
during patch testing are often reported at the time of test reading. However,
with the exception of itch on the back, symptoms and signs are rather less common
after the application of patch tests than before.
PMID- 10684390
TI - Allergic contact dermatitis caused by parabens: 2 case reports and a review.
AB - Parabens, methyl, ethyl, propyl, benzyl, and butyl, are the most common
preservatives in use today. They are the alkyl esters of p-hydroxybenzoic acid
and are used extensively because they are relatively nonirritating and nontoxic
and offer good antimicrobial coverage. Testing for paraben allergen can be done
by patch testing. Two cases of allergic contact dermatitis (ACD) to parabens are
used to discuss the background of parabens, their allergenicity, patch testing
issues, and several "paraben paradoxes." Although ACD to parabens has been
reported, given the widespread use, it is relatively uncommon. Because of their
low rate of allergenicity and their favorable preservative profile and efficacy,
parabens remain the number one preservative in use.
PMID- 10684391
TI - Phototesting and photopatch testing: when to do it and when not to do it.
AB - Phototesting and photopatch testing are among the most important tests in the
evaluation of photodermatoses, yet their use has been restricted to specialized
centers. To assist clinicians interested in conducting these procedures and in
updating their techniques, we asked 4 experts to comment on these tests in the
context of diagnostic approach to the photosensitive patient. A list of
photoallergens and a protocol for their use is provided.
PMID- 10684392
TI - Why a New Journal in Cardiovascular Pharmacology and Therapeutics?
PMID- 10684393
TI - Antiarrhythmic Therapy of Ventricular Arrhythmias: The Contemporary Dilemma.
PMID- 10684394
TI - Effects of Sotalol on His-Purkinje Conduction and Refractoriness in Humans.
AB - BACKGROUND: The effects of sotalol on refractoriness in human ventricular and
atrial muscles have been well established, but the drug's effect on the
electrical properties of the His-Purkinje system in humans is not known,
especially whether sotalol's effect is due solely to its action on prolonging
repolarization or in combination with its beta-blocking properties. We studied
the electrophysiologic effects of intravenous sotalol and propranolol in patients
undergoing electrophysiologic studies of cardiac arrhythmias. METHODS AND
RESULTS: We studied 22 patients (19 men, 3 women; mean age, 60 +/- 6 years) who
had coronary artery disease and assessable anterograde, retrograde, or both, His
Purkinje system function. Fifteen patients underwent electrophysiologic studies
before and after intravenous sotalol (1.5 mg/kg), and 7 patients underwent
electrophysiologic studies before and after intravenous propranolol (0.15 mg/kg).
Both sotalol and propranolol had no significant effect on the H-V interval, but
sotalol significantly increased ventricular refractoriness and His-Purkinje
refractoriness, both in anterograde and retrograde conduction, whereas
propranolol did not, Sotalol's effect on His-Purkinge refractoriness also caused
atrioventricular block distal to the His bundle during atrial pacing at a
moderately fast rate. Sotalol was not effective in preventing bundle branch re
entry tachycardia, nevertheless, it increased cycle length of bundle branch re
entry tachycardia by increasing refractoriness. CONCLUSIONS: Sotalol increased
His-Purkinje refractoriness in humans but had no effect on His-Purkinje
conduction. The drug must be used judiciously in patients with a diseased His
Purkinje system because it may cause atrioventricular block distal to His at fast
heart rates. Sotalol had no effect on macrore-entry utilizing bundle branches.
PMID- 10684395
TI - Investigative Concerns in Demonstrating Reduced Risk From Reversing Left
Ventricular Hypertrophy.
AB - BACKGROUND: To demonstrate reduced risk from reversing left ventricular
hypertrophy (LVH) in hypertension, one must show that it is independent of blood
pressure reduction. METHODS AND RESULTS: A feasibility study was conducted with
15 patients. The study employed 48-hour Holter recording, exercise treadmill (for
ST-segment changes) and, as necessary, thallium scintigraphy and coronary
angiography. All patients were treated for 3 months with quinapril (10 mg) and
demonstrated decreased mean arterial pressure (125 +/- 3.1 vs 103 +/- 1.9 mmHg; P
<.01) and left ventricular mass index (125 +/- 6.4 vs 104 +/- 4.9; P <.02) with
preserved left ventricular function. There were no significant changes in these
patients with moderate LVH in the incidence of arrhythmias; however, 4 of the 15
patients developed ST-segment changes prior to LVH reversal, and these changes
did not recur in 3 patients following reversal of LVH or when pressure was
allowed to rise. CONCLUSIONS: Ischemic changes, rather than development of
arrhythmias, may be of greater value in demonstrating risk reduction with LVH
reversal. Moreover, these preliminary data suggest pitfalls in demonstrating risk
reduction after LVH reversal, indicating that more sensitive and adequate
techniques are necessary to show risk reduction from LVH.
PMID- 10684396
TI - A Randomized Multicenter Trial Comparing and Efficacy of Simvastatin and
Fluvastatin.
AB - BACKGROUND: Inhibitors of hydroxymethylglutaryl co-enzyme A reductase are widely
used for the treatment of hypercholesterolemia. Physicians and third-party payers
need an accurate measure of their relative potency and hypolipidemic efficacy. We
have therefore compared simvastatin against fluvastatin, the newest member of
this class. METHODS AND RESULTS: One hundred fifty-eight hypercholesterolemic
patients in seven United States lipid clinics participated in this balanced
double-blind incomplete block study. After a placebo-diet run-in period, patients
received treatment with active drug for three consecutive 5-week periods, with
measurement of lipids in a NHLBI-CDC standardized central laboratory at the end
of each period. Each patient was randomly assigned to three of the following five
treatments: simvastatin 5 mg, 10 mg, and 20 mg and fluvastatin 20 mg and 40 mg.
The mean percent reductions in low density lipoprotein cholesterol from baseline
were 21, 27, 32, 16, and 23 respectively. The simvastatin/fluvastatin milligram
potency ratio was 6.8 (95% CI, 5.3-9.3). At the same 20 mg dose, simvastatin
produced an effect on LDL cholesterol approximately double that of fluvastatin
and resulted in 46% of patients achieving their National Cholesterol Education
Program low density lipoprotein cholesterol target levels, compared to 12% for
fluvastatin. CONCLUSIONS: Fluvastatin at its maximal dose of 40 mg daily is
approximately equivalent to simvastatin 5 mg daily. Higher doses of simvastatin
are considerably more effective in the treatment of primary hypercholesterolemia.
PMID- 10684397
TI - Protective Effect of Elastase Inhibition Against Myocardial Dysfunction and
Injury Induced by Ischemia and Reperfusion in Isolated Rat Hearts.
AB - BACKGROUND: Elastase release has been incriminated in the genesis of reperfusion
induced myocardial dysfunction and injury, and elastase inhibitors have been
reported to reduce myocardial dysfunction in dogs subjected to coronary artery
occlusion and reperfusion. METHODS AND RESULTS: To examine if elastase inhibition
will modify myocardial dysfunction and injured induced by ischemia and
reperfusion in isolated hearts, hearts from male Sprague Dawley rats were
subjected to 30 minutes of total ischemia followed by 30 minutes of reperfusion.
Ischemia-reperfusion resulted in myocardial dysfunction (increase in coronary
perfusion pressure and decrease in myocardial contraction), injury (measured as
creatine kinase release), and lipid peroxidation (myocardial malondialdehyde).
Perfusion of hearts with an elastase inhibitor, ICI200,880, protected against
myocardial dysfunction, injury and lipid peroxidation following ischemia
reperfusion. As expected, perfusion with superoxide dismutase protected the
hearts against hemodynamic deterioration following ischemia-reperfusion. In in
vitro studies, there was no direct effect of ICI200,880 on superoxide anion
generation. CONCLUSIONS: ICI200,880 seems to exert cardioprotective effects
against ischemia-reperfusion-induced injury and myocardial dysfunction in
isolated buffer-perfused hearts, most likely by an elastase-like protease
inhibitory activity.
PMID- 10684398
TI - Electrophysiologic Effects of Beta-blocking Agent, Tilisolol, on Isolated Guinea
Pig Ventricular Myocytes.
AB - BACKGROUND: Electrophysiologic effects of a beta-blocking agent, tilisolol, were
studied with isolated guinea pig ventricular myocytes using the whole cell patch
clamp technique. METHODS AND RESULTS: Tilisolol at 10 uM or higher concentrations
prolonged action potential duration (APD) at 90% repolarization (APD(90)) and at
100 uM or higher concentrations shortened APD at 20% repolarization (APD(20))
without changes in resting membrane potential. At 10 uM concentration tilisolol
prolonged APD(90) from 236.6 +/- 55.3 ms in the control to 253.4 +/- 52.4 ms (n =
16; P <.01), while APD(20) was unaffected. At 100 uM tilisolol, APD(20) was
shortened from 143.6 +/- 15.7 ms in the control to 133.7 +/- 22.6 ms (n = 8; P
<.05). Under voltage clamp, tilisolol decreased the delayed rectifier K(+)
current (I(K1)). Applications of 10 uM and 100 uM tilisolol reduced the maximal
conductance of I(K) by 35.7 +/- 3.5% and 47.4 +/- 3.5% of the control,
respectively, without changes in voltage dependence (n = 10). Tilisolol at 100 uM
decreased the L-type Ca(2+) current (I(Ca.L)) by 22.0 +/- 9.8% (n = 6) of the
control, and the inactivation curve was shifted to a hyperpolarizing direction.
CONCLUSIONS: Tilisolol has a direct membrane action to depress I(K) and I(Ca.L),
in addition to its beta-receptor blocking action.
PMID- 10684399
TI - Reduction of Myocardial Infarct Size in the Rabbit by a Carbohydrate Analog of
Sialyl Lewis(x).
AB - BACKGROUND: Available data suggest that the accumulation of neutrophils within
the myocardium following an ischemic event plays an important role in the
pathogenesis of myocardial ischemia/reperfusion injury. It is of interest,
therefore, to develop pharmacologic agents designed to inhibit neutrophil
adhesion to the endothelium. METHODS AND RESULTS: A synthetic carbohydrate analog
to the P-selectin ligand sialyl Lewis(x) (sLe(x)) was evaluated for its ability
to protect the myocardium from ischemia/reperfusion injury. Open chest
anesthetized rabbits were subjected to 30 minutes occlusion of the left
circumflex artery followed by 5 hours of reperfusion. Vehicle or sLe(x) analog
(10 mg/kg) was administered intravenously before the onset of reperfusion and
every hour during the reperfusion period. Myocardial infarct size in rabbits
treated with the sLe(x) analog (10 mg/kg) was administered intravenously before
the onset of reperfusion and every hour during the reperfusion period. Myocardial
infarct size in rabbits treated with the sLe(x) analog was significantly reduced
when compared to rabbits treated with vehicle (28 +/- 9% vs 57 +/- 10% of the
area at risk, p <.05). The compound did not alter circulating neutrophil counts
or myocardial oxygen demand as determined by the rate-pressure product.
Furthermore, neutrophil accumulation within the ischemic region was decreased by
44% (P <.05) in the hearts of animals receiving sLe(x) analog as compared to
vehicle. CONCLUSIONS: Carbohydrate derivatives of sLe(x) may be effective in
reducing the degree of myocardial injury after ischemia/reperfusion.
PMID- 10684400
TI - Hydrochlorothiazide Increases Efferent Glomerular Arteriolar Resistance in
Spontaneously Hypertensive Rats.
AB - BACKGROUND: Micropuncture studies were performed to determine the intrarenal
hemodynamic effects of two conventional antihypertensive agents,
hydrochlorothiazide (HCTZ) and hydralazine (HYDR) alone and in combination.
METHODS AND RESULTS: Male spontaneously hypertensive and normotensive Wistar
Kyoto rats (19 weeks old) were treated for 3 weeks with vehicle (control), HCTZ
(80 mg/kg/d), HYDR (5 mg/kg/d), or combined therapy (HCTZ 30 mg/kg/d and HYDR 2
mg/kg/d). Each treatment significantly reduced arterial pressure while effective
renal plasma flow, glomerular filtration rate and single nephron glomerular
filtration rate were unaffected by any treatment in either strain. In
spontaneously hypertensive rats HCTZ decreased single nephron plasma flow (111 +/
8 to 84 +/- 4 nL/min; P <.05) but, despite this reduction, glomerular pressure
remained unchanged (51.4 +/- 0.7 to 52.1 +/- 0.8 mmHg) attributable to increased
efferent glomerular resistance (1.58 +/- 0.14 to 2.11 +/- 0.12 10 U; P <.05). By
contrast, HYDR increased single nephron plasma flow (to 147 +/- 8 nL/min; P <.01)
and decreased efferent glomerular resistance (to 1.09 +/- 0.09 U; P <.05).
Combined treatment produced responses similar to HCTZ when used alone, thereby
nullifying the beneficial efferent glomerular resistance effects: single nephron
plasma flow +/- fell (to 89 +/- 7 nL/min; P <.05) and efferent glomerular
resistance increased (to 2.05 +/- 0.17 U; P <.05). In Wistar Kyoto rats, HCTZ and
combined treatment had no effect. HCTZ alone induced glomerular ischemia that was
associated with efferent glomerular arteriolar constriction in these
spontaneously hypertensive rats. CONCLUSIONS: These findings provide a possible
explanation for the lack of improved renal target-organ damage in controlled
multicenter trials employing thiazide diuretics.
PMID- 10684401
TI - Differences in the Effects of d- and dl-Sotalol on Isolated Human Ventricular
Muscle: Electromechanical Activity After Beta-Adrenoceptor Stimulation.
AB - BACKGROUND: The racemate of sotalol (dl-sotalol) and its dextrorotatory isomer (d
sotalol) are equally effective in increasing isolated cardiac action potential
durations. dl-Sotalol, however, is reported to be more effective than d-sotalol
in increasing ventricular effective refractoriness following coronary artery
occlusion. These differences are attributed to the beta-adrenergic blocking
properties of dl-sotalol. We wished to determine if in isolated human ventricular
muscle preparations the effects of 30 uM d0 and dl-sotalol could be modified by
preexposure to 1 uM isoproterenol. METHODS AND RESULTS: Microelectrodes were used
to record action potential duration (APD) in the presence and absence of
isoproterenol during continuous pacing. Preparations were obtained from explanted
hears of transplant recipients suffering idiopathic cardiomyopathies. Without
isoproterenol, APD measured at 90% of repolarization (APD(90)) was significantly
increased by both d- and dl-sotalol (352.0 +/- 17.7 to 418.0 +/- 23.8 ms, P <.05;
and 339.2 +/- 17.0 to 405.0 +/- 25.3 ms, P <.05; respectively). Isoproterenol
alone, prior to sotalol exposure, tended to shorten APD(90) in the two groups
first exposed to this beta-adenoceptor agonist and subsequently exposed to either
d-sotalol or dl-sotalol (317.5 +/- 16.5 to 286.3 +/- 28.8 ms and 288.0 +/- 16.2
to 254.0 +/- 15.0 ms, respectively). dl-Sotalol significantly increased APD(90)
from its baseline value after isoproterenol (288.0 +/- 16.2 to 359.0 +/- 25.1 ms,
P <.005) while d-sotalol did not (317.5 +/- 16.5 to 316.2 +/- 28.5 ms, NS).
CONCLUSIONS: The beta-adrenergic blocking properties of dl-sotalol may be
important in determining antiarrhythmic efficacy when tonic sympathetic nervous
activity is high.
PMID- 10684402
TI - Amiodarone Therapy After Previous Sotalol-induced Torsade de Pointes: Analysis of
AT Dispersion to Predict Proarrhythmia.
AB - BACKGROUND: Polymorphic ventricular tachycardia of the torsade de pointes type
represents, potentially, the most dangerous side effect of antiarrhythmic drugs
that prolong ventricular repolarization. Much effort has been devoted to the
identification of the degree of drug-associated QT prolongation that might
predict the occurrence of torsade de pointes. However, there is still no general
agreement as to which level of QT prolongation might be the harbinger of torsade
and which may simply represent the manifestation of the class III antiarrhythmic
effect of a given compound. METHODS AND RESULTS: A 70-year-old woman who had
survived an episode of cardiac arrest outside of a hospital was treated with dl
sotalol (320 mg/d). After 8 days of therapy, she developed two episodes of
hemodynamically unstable torsade de pointes. Sotalol was withdrawn and after
extensive diagnostic work, therapy with amiodarone therapy was comparable to that
observed during sotalol exposure, the patient tolerated amiodarone and is now
free of recurrent ventricular tachyarrhythmias over a follow-up period of 1 year.
Analysis of QT dispersion in the surface electrocardiograph revealed a marked
increase during sotalol therapy but not during amiodarone administration (77 vs
47 ms). During drug-free control, QT dispersion was 43 ms. CONCLUSIONS: These
findings emphasize the potential usefulness of determination of QT dispersion
from the surface ECG to assess disparity in ventricular recovery, which is known
to favor the occurrence of torsade de pointes. These observations need to be
corroborated in large prospective trials. Finally, this case report further
emphasizes the low arrhythmogenic potential of amiodarone-an unexplained paradox,
the understanding of which might provide insights for the development of newer
antifibrillatory compounds.
PMID- 10684403
TI - Data-driven Decisions: The Importance of Clinical Trials in Arrhythmia
Management.
AB - As a result of clinical trials, the measurement of arrhythmias has evolved over
the past three decades. In the late 1960s, customary teaching was that
ventricular premature depolarizations were dangerous and antiarrhythmic therapy,
in hopes of reducing fatal consequences, became common place; however, following
clinical trials such as CAST, IMPACT, and SWORD, we learned that, at least in
postinfarct patients, arrhythmia suppression may lead to increased rather than
reduced mortality. Such trials have led to a marked reduction in therapy of
indiscriminate ventricular ectopy and have led to ongoing testing of specific
subgroups identified as having particularly higher adverse prognostic risk. With
the advent of cardiac monitoring and the confirmation that ventricular
tachyarrhythmias are the most common cause for sudden death, their therapy, too,
has evolved and matured, again aided by clinical trials. The ESVEM study
prospectively examined the role of monitor-guided versus electrophysiologically
guided drug therapy of ventricular tachyarrhythmias and confirmed that both
approaches may have a role in reducing arrhythmic deaths-though the specific
benefits of each technique remain somewhat unsettled. Both the ESVEM and CASCADE
studies suggested that the most effective drugs for ventricular tachyarrhythmias
are the class II/III drugs, sotalol and amiodarone, both appearing more effective
than our older class I agents. These should now be viewed as the first-line drugs
for these arrhythmias. The relative benefits of these two agents with respect to
each other and to implantable cardioverter defibrillators, however, remains to be
determined by further clinical trials, such as AVID and CIDS. The therapy of
atrial tachyarrhythmias has similarly evolved with the aid of clinical
observations. While rate control is required in all patients with atrial
fibrillation, we have come to realize that the applications of antiarrhythmic
drugs for the purpose of maintaining sinus rhythm must be used only selectively
rather than uniformly. Both a meta-analysis by Coplen and colleagues and a report
by the SPAF investigators suggested that with atrial arrhythmias, too,
antiarrhythmic drug therapy may result in enhanced rather than reduced mortality
in some circumstances. Additional clinical trials are needed to further elucidate
the role of antiarrhythmic therapy of atrial fibrillation.
PMID- 10684404
TI - Rise and Fall of Guided Antiarrhythmic Therapy for Ventricular Tachycardia and
Fibrillation.
PMID- 10684405
TI - The Effects of Amlodipine on Left Ventricular Mass and Diastolic Function in
Concentric and Eccentric Left Ventricular Hypertrophy.
AB - BACKGROUND: The effects of the antihypertensive therapy with amlodipine (5-10
mg/day) on left ventricular mass and diastolic function were examined in 30 mild
to moderate essential hypertensive patients who have left ventricular hypertrophy
(LVH) and diastolic dysfunction. METHODS AND RESULTS: Each patient's left
ventricular mass was measured, and left ventricular diastolic function was
assessed by echocardiographic Doppler examination at entry, and at 3 and 6 months
after the initiation of the treatment. Amlodipine reduced both blood pressure
(from 164 +/- 14/104 +/- 6 mmHg to 134 +/- 9/83 +/- 4 mmHg) and left ventricular
mass index (from 160 +/- 30 g/m(2) to 137 +/- 26 g/m(2)) significantly at 3
months and both parameters maintained at these levels for 6 months. When the
patients were classified according to the type of the LVH, a significant
regression in left ventricular mass index was seen only in the patients who had
concentric LVH was a relative wall thickness >/=0.44 (n = 16), but not in the
eccentric LVH group (n = 14), although both groups were not significantly
different from each other regarding the basal hemodynamic parameters, baseline
left ventricular mass index and the decrease in blood pressure in response to
amlodipine treatment. The mitral inflow E/A ratio did not show any significant
change in either group. CONCLUSIONS: Amlodipine produced significant regression
in LVH only in the patients with concentric LVH, but not those with eccentric
LVH, while it did not change the diastolic dysfunction. Therefore, the type of
LVH seems to be an important feature in determining the effects of
antihypertensive treatment on left ventricular mass index.
PMID- 10684406
TI - A Comparison of the Tolerability and Efficacy of Lovastatin 20 mg and Fluvastatin
20 mg in the Treatment of Primary Hypercholesterolemia.
AB - BACKGROUND: To compare the cholesterol-lowering potency of fluvastatin and
lovastatin, a randomized, prospective, open-label parallel study was conducted in
patients eligible for drug therapy by National Cholesterol Education Program
guidelines. The study was conducted at eight centers in the United States.
METHODS AND RESULTS: Patients were required to follow a cholesterol-lowering diet
and were withdrawn from all lipid-lowering agents for 4 seeks prior to study
entry. Patients were randomized to receive lovastatin 20 mg of fluvastatin 20 mg
daily for 6 weeks. The two treatment groups were comparable with respect to
demographic and clinical characteristics. Baseline lipid levels in the two groups
were comparable. Lovastatin was significantly more effective than fluvastatin in
lowering total cholesterol (-;19.5% vs -12.8%, P <.001) and low-density
lipoprotein cholesterol (-27.6% vs -18.2%, P <.001). Changes in high-density
lipoprotein and triglyceride levels were comparable in the two groups. The
differences in cholesterol lowering were similar in the three strata of coronary
heart disease risk factor status as defined by the second NCEP Adult Treatment
Panel. Both treatments were well tolerated. CONCLUSIONS: Across the three chronic
heart disease risk strata, lovastatin appears to be significantly more potent
than fluvastatin, on a per milligram basis, in lowering cholesterol levels.
PMID- 10684407
TI - Efficacy and Tolerability of Low-dose Simvastatin and Niacin, Alone and in
Combination, in Patients With Combined Hyperlipidemia: A Prospective Trial.
AB - BACKGROUND: Combination lipid-lowering therapy may be desirable in patients with
elevated low-density lipoprotein cholesterol, high triglycerides, and low high
density lipoprotein cholesterol. This study was conducted to determine the lipid
lowering efficacy of the combination of low-dose simvastatin and niacin in
patients with combined hyperlipidemia and low high-density lipoprotein
cholesterol. METHODS AND RESULTS: In this multicenter, prospective, randomized
trial, 180 patients with hypercholesterolemia and hypertriglyceridemia and/or low
high-density lipoprotein cholesterol were randomized to combination simvastatin
(10 mg/day) and niacin (0.75 g/day) or to either drug alone for 9 weeks. The dose
of niacin was doubled (from 0.75 g/day to 1.5 g/day) in both the combination and
niacin arms for the remaining 8 weeks. The combination of simvastatin, 10 mg/day,
and niacin, 1.5 g/day, reduced total, low-density lipoprotein, and very low
density lipoprotein cholesterol and triglycerides by 24%, 29%, 45%, and 31%,
respectively, while increasing high-density lipoprotein cholesterol by 31%. The
addition of niacin to simvastatin did not enhance the low-density lipoprotein
cholesterol by 31%. The addition of niacin to simvastatin did not enhance the low
density lipoprotein cholesterol-lowering effect of simvastatin; however, the
combination was more effective than either monotherapy at raising high-density
lipoprotein cholesterol and lowering very low-density lipoprotein cholesterol (P
<.05). More patients discontinued treatment because of an adverse event in the
niacin (P <.03) and combination groups (P =.06) than the simvastatin group.
CONCLUSIONS: Treatment of patients with combined hyperlipidemia and/or low high
density lipoprotein with combination low-dose simvastatin and niacin resulted in
large reductions in total, low-density lipoprotein, and very low-density
lipoprotein cholesterol and increases in HDL cholesterol. Although the
combination was well tolerated in the current trial, its safety needs to be
evaluated in larger trials of longer duration.
PMID- 10684408
TI - Atorvastatin, a New HMG-CoA Reductase Inhibitor as Monotherapy and Combined With
Colestipol.
AB - BACKGROUND: Atorvastatin, a new HMG-CoA reductase inhibitor in clinical
development has demonstrated an acceptable safety profile and marked cholesterol
and triglyceride reduction at doses ranging from 10-80 mg/day. Since bile acid
sequestering resins are often used in combination with HMGRIs to enhance
cholesterol reduction, this trial was conducted to explore the use of
atorvastatin alone and combined with colestipol in patients with primary
hyperlipidemia. METHODS AND RESULTS: One hundred six patients with low-density
lipoprotein (LDL) cholesterol >4.1 mM/L (160 mg/dL) and plasma triglycerides <3.9
mM/L (350 mg/dL) were randomized to treatment consisting of 20 g/day colestipol,
10 mg/day atorvastatin, or 10 mg/day atorvastatin plus 20 g/day colestipol for 12
weeks. Percent change from baseline in lipid variables were measured. The
atorvastatin group showed a significant reduction in LDL cholesterol of 35% after
12 weeks. Combination therapy provided an additional 10% reduction in LDL
cholesterol over that observed for atorvastatin alone. Twenty-one percent of all
patients in the atorvastatin monotherapy group experienced associated adverse
events compared with 60% in the combination therapy group. Ninety percent of
atorvastatin monotherapy patients were compliant at every visit compared with 75%
receiving combination therapy. CONCLUSIONS: Although the combination of
atorvastatin plus colestipol was more effective in lowering LDL cholesterol than
atorvastatin alone, atorvastatin 10 mg/day monotherapy provided a better safety
profile and improved patient compliance, which may result in improved long-term
cholesterol control.
PMID- 10684409
TI - Therapy of Sustained Ventricular Arrhythmias With Amiodarone: Prediction of
Efficacy With Serial Electrophysiologic Studies.
AB - BACKGROUND: Programmed electrical stimulation early during amiodarone therapy has
poor prognostic capabilities; and persistent inducibility has been associated
with a favorable outcome in a majority of patients. These observations result
from studies that differed significantly in methodology. METHODS AND RESULTS: The
authors prospectively enrolled 121 patients in a standardized amiodarone dosing
protocol in which amiodarone was the only antiarrhythmic agent.
Electrophysiologic testing was done after 2 and 6 weeks to determine
noninducibility, predictive value, and the significance of drug-induced
prolongation of tachycardia cycle length. The mean age of the patients in the
study was 63.2 +/- 11.5 years, and their ejection fraction was 32.8 +/- 11.9%.
Coronary artery disease was present in 103 (85%). At 2 weeks 17 patients (14%)
were no longer inducible, whereas 104 patients (86%) remained inducible. Patients
in these groups were similar in age and ejection fraction. During follow-up
evaluation, recurrences (35% vs 24%; P =.44) and sudden death (12% vs 13.5%) were
similar in the two groups. Thirty-five of 95 patients (32%) with sustained
monomorphic ventricular tachycardia had more than 100 ms prolongation of their
cycle length, which was hemodynamically well tolerated (partial response), but 60
did not (nonresponse). Patients with a partial response were older (66.5 vs 61.1
years; P =.02) and had longer QRS durations (143.2 vs 129.4 ms; P =.03). They
also had increased recurrences (37% vs 17%; P =.01) and more sudden deaths (23%
vs 8%; P =.02). At 6 weeks 11 of 76 patients studied were noninducible. They had
a lower recurrence rate than those who remained inducible (8% vs 27%; P =.02) but
a similar number of sudden deaths (8% vs 16%; P =.27). Thirty-two patients
partially responded, and 31 patients did not respond. During follow-up
examination these two groups had a similar number of recurrences (25% vs 29%; P
=.76) and sudden deaths (16% vs 16%). CONCLUSIONS: Noninducibility at 2 or 6
weeks of amiodarone therapy did not identify patients at low risk of sudden
death. In inducible patients, tachycardia cycle length prolongation, even when
well tolerated, was not a marker for favorable outcome. Electrophysiologically
guided therapy, therefore, offers little benefit over empiric amiodarone.
PMID- 10684410
TI - Comparison of the Electromechanical Effects of Vesnarinone and Amrinone in
Isolated Dog Purkinje Strands and Ventricular Trabeculae.
AB - BACKGROUND: Conventional microelectrode techniques were used to compare the
concentration-dependent effects of vesnarinone (0.1-100 uM) and amrinone (1 uM-1
mM) on action potential duration (APD) and developed force in both isolated dog
ventricular trabeculae and Purkinje strands. METHODS AND RESULTS: Both drugs
increased contractility of trabecular muscle preparations, while, in Purkinje
strands, vesnarinone failed to increase developed force during continuous pacing
at 2 Hz. Vesnarinone lengthened APD in both preparations; although this effect
was more marked in Purkinje strands. Ventricular muscle APD was not affected by
amrinone (1 uM to 1 mM), while, in Purkinje strands, amrinone produced a biphasic
effect on APD. Low concentrations (1-100 uM) of amrinone shortened Purkinje fiber
APD, while only the highest concentration (1 mM) used lengthened APD. In
addition, in Purkinje strand preparations the effects of vesnarinone (10 uM) on
APD and developed force were proportional to pacing cycle length at frequencies
slower than 2 Hz; however, at frequencies faster than 2 Hz vesnarinone decreased
developed force while APD was lengthened. In ventricular trabecular muscle
preparations, the effects of vesnarinone were not affected by frequency.
CONCLUSIONS: These results indicate clear differences between the effects of
vesnarinone and amrinone in isolated cardiac preparations. These differences in
experimental effects in isolated cardiac preparations may help provide an
explanation for the disappointing clinical response of patients in heart failure
to amrinone, while vesnarinone has appeared to be beneficial.
PMID- 10684411
TI - Protective Effects of Ranolazine on Ventricular Fibrillation Induced by
Activation of the ATP-Dependent Potassium Channel in the Rabbit Heart.
AB - BACKGROUND: The authors studied the antifibrillatory effects of the adenosine
triphosphate (ATP)-sparing metabolic modulator ranolazine in a rabbit isolated
heart model in which ventricular fibrillation occurs under conditions of
hypoxia/reoxygenation in the presence of the ATP-dependent potassium channel
opener pinacidil. METHODS AND RESULTS: Ten minutes after ranolazine or vehicle
administration, addition of pinacidil (1.25 uM) to the buffer was followed by a
12-minute hypoxic period and 40 minutes of reoxygenation. At a reduced
concentration of ranolazine (10 uM), ventricular fibrillation occurred in 60% of
the hearts, compared to 89% in the control group (P = NS). In contrast, only
three of nine hearts (33%) treated with 20 uM ranolazine developed ventricular
fibrillation (P <.05 vs vehicle). Hemodynamic parameters including coronary
perfusion pressure, left ventricular developed pressure, and +/-dP/dt were not
affected by the presence of ranolazine in the perfusion medium. Ranolazine did
not prevent or modify the negative inotropic or coronary vasodilator actions of
pinacidil, suggesting a mechanism of action independent of potassium channel
antagonism. CONCLUSIONS: Ranolazine significantly reduced the incidence of
ventricular fibrillation in the hypoxic/reoxygenated heart exposed to the ATP
dependent potassium channel opener, pinacidil. The reported ability of ranolazine
to prevent the decrease in cellular ATP during periods of a reduced oxygen supply
may account for its observed antifibrillatory action. By maintaining
intracellular ATP, ranolazine may modulate or prevent further opening of the ATP
dependent potassium channel in response to hypoxia and/or pinacidil.
PMID- 10684412
TI - Evidence of Na Current Contribution to the Transient Outward Current in Cardiac
Ventricular Myocytes.
AB - BACKGROUND: To study the transient outward current (I(to)) investigators often
use sodium-free external solution to minimize the possible contamination of I(to)
by sodium current. Removal of extracellular sodium creates reversal of sodium
gradient and thus possibly contributing to I(to) mainly at positive potentials.
METHODS AND RESULTS: To address this issue, whole-cell I(to) was recorded in
sodium-free choline chloride and cobalt solutions, from rat ventricular myocytes
known to exhibit a prominent I(to). Depolarizing pulse to 40 mV from -100 mV
holding potential every 10 seconds elicited a fast activating and time-dependent
inactivating components. The activation of I(to) was fast and complete within 10
ms at 40 mV, and the decay was rapid over the first 100 ms of the pulse and
slower thereafter. External superfusion of the cell with 50 uM tetrodotoxin
reversibly reduced I(to) amplitude by 25% from 1.47 +/- 0.2 to 1.1 +/- 0.3 nA (P
<.04, n = 9). When sea anemone toxin (ATXII), known to selectively enhanced I(Na)
by causing a delay in the inactivation gate, is applied to the cell, I(to)
amplitude increased in a time- and dose-dependent manner (EC(50) =.86.4 nM).
ATXII (100 nM) dramatically increased I(to) amplitude at all voltages between -20
and 60 mV (from 1.51 +/- 0.4 to 3.35 +/- 0.8 nA at 40 mV, P <.003, n = 12).
Superfusion of cells with 5 mM 4-AP resulted in 82% reduction in I(to) amplitude
at 40 mV (from 1.95 +/- 0.5 to 0.37 +/- 0.2 nA, P <.02, n = 8). Addition of ATXII
to 4-AP containing solution increased peak I(to) by 965% (from 0.37+/-0.2 to 3.95
+/- 0.9, n = 8, P <.0003). However, in 11 other cells, addition of tetrodotoxin
(50 uM) to the ATXII-containing solution blocked ATXII-induced outward current
(from 3.51 +/- 0.64 nA to 1.60 +/- 0.17 nA, P <.05). The conductance (G(Ito)) was
calculated by dividing peak I(to) by (Vm-E(K)), with an E(K) of -75 mV. G(Ito)
was increased at all voltages (greater than -40 mV). Normalized G(Ito) was fitted
by Boltzmann equation and ATXII did not significantly modify V(0.5) and k (from
20.5 +/- 3.9 to -17.0 +/- 3.5 mV for V(0.5), and 12.2 +/- 2.6 to 13.4 +/- 2.1 mV
for k, n = 4). Also, atropine (1 uM) did not have any significant effect on I(to)
(from 1.92 +/- 0.15 nA to 1.85 +/- 0.25 nA, n = 5). CONCLUSIONS: The results
showed that, in sodium-free external solution I(to) is tetrodotoxin but not
atropine sensitive. ATXII-induced I(to) increase is 4-aminopyridine insensitive
but tetrodotoxin sensitive. These data suggest that outward Na current due to
reversal of Na gradient in the absence of external Na contributes to I(to).
Caution must be taken when studying kinetics and pharmacology of I(to) in
external sodium-free solutions.
PMID- 10684413
TI - Sudden Death During Flecainide Therapy for Atrial Fibrillation Complicating Wolff
Parkinson-White Syndrome.
AB - The Wolff-Parkinson-White syndrome can be complicated by atrial fibrillation that
may increase morbidity and mortality. Different pharmacologic therapy, includes
class IA, IC, and III agents, has been used in such cases with variable success.
We now use less pharmacologic intervention with development of an electrode
catheter ablation for accessory pathways. However, antiarrhythmic agents are
still being used, especially when an electrode catheter ablation is unavailable
or if a patient refuses such a procedure. Therefore, it is prudent that one
understands each antiarrhythmic agents' electropharmacologic properties as well
as its potential proarrhythmic effect in order to accurately assess each drug's
risk-benefit ratio. We present a case that illustrates electropharmacologic
properties of quinidine, flecainide, sotalol, and amiodarone on various cardiac
tissues, as well as possible proarrhythmic effect of flecainide on a structurally
normal heart.
PMID- 10684414
TI - New Antithrombotic Drugs of Coronary Artery Disease.
PMID- 10684415
TI - Prevention of Restenosis by Local Drug Delivery.
AB - Local drug therapy for preventing restenosis after angioplasty has been
investigated for over a decade. Biologically active agents ranging from drugs to
genes can be delivered locally using a wide variety of catheters. Microspheres,
liposomes, and polymers have been used to enhance drug retention at the delivery
site. More recently stents have been investigated as devices to attain local drug
delivery, either by coating with polymers, seeding with genetically modified
cells or by using them as a source of local radiation. Though the best method of
delivering agents locally remains undefined, this approach is likely to emerge as
an essential mode of therapy in the near future.
PMID- 10684416
TI - Influencing Mortality in Cardiac Disorders by Controlling Arrhythmias or by
Cardioprotection: Whither Magnesium?
PMID- 10684417
TI - Treatment Effect of Niaspan, a Controlled-release Niacin, in Patients With
Hypercholesterolemia: A Placebo-controlled Trial.
AB - BACKGROUND: The present study was designed to determine the efficacy and safety
of Niaspan (Kos Pharmaceuticals, Inc, Hollywood, FL), a new controlled-release
formulation of niacin, in the treatment of primary hyperlipidemia, the occurrence
and severity of flushing events, and potential adverse effects, particularly
hepatotoxicity. METHODS AND RESULTS: The study was conducted as a multicenter,
randomized, double-blind, placebo-controlled, parallel comparison of Niaspan in
doses of 1000 mg/day and 2000 mg/day, administered once a day at bedtime. One
hundred twenty-two patients with low-density lipoprotein cholesterol levels >4.14
mM/L (160 mg/dL) with dietary intervention and high-density lipoprotein
cholesterol =1.81 mM/L (70 mg/dL) were randomized to one of three treatment
groups: placebo, and 1000 mg/day or 2000 mg/day of Niaspan. Safety and efficacy
measures included 12-hour serum fasting lipid and lipoprotein concentrations,
serum analyte levels for major organ function, flushing diaries, and adverse
event records. The placebo group demonstrated no significant changes in serum
lipoprotein concentrations over the treatment period of 12 weeks, except for a
slight 4% increase in high-density lipoprotein cholesterol. Niaspan significantly
lowered low-density lipoprotein cholesterol levels by 6% and 14% for the 1000
mg/day and 2000 mg/day doses, respectively. High-density lipoprotein cholesterol
levels rose significantly, with a 17% increase occurring at the 1000 mg/day dose
and a 23% increase occurring at the 2000 mg/day doses, respectively. High-density
lipoprotein cholesterol levels rose significantly, with a 17% increase occurring
at the 1000 mg/day dose and a 23% increase occurring at the 2000 mg/day dose.
Niaspan (2000 mg/day) produced significant decreases of 27% and 29%,
respectively, for serum lipoprotein(a) and triglyceride concentration. Although
the incidence of flushing was significant, these episodes were generally well
tolerated. CONCLUSION: Niaspan administered in doses of 1000 mg/day and 2000
mg/day at bedtime were well tolerated with few side effects and produced
favorable effects on the major circulating lipoproteins of patients with primary
dyslipidemias as specified by the enrollment criteria.
PMID- 10684418
TI - Dipyridamole Potentiates the Endothelium-Dependent and -Independent Vasomotion in
Isolated Human Small Arteries.
AB - BACKGROUND: To investigate the effects of dipyridamole, a drug with
phosphodiesterase-, adenosine reuptake-inhibiting, and prostacyclin-stimulating
activity on the biological actions of nitric oxide, 30 norepinephrine
precontracted subcutaneous arterioles were prepared from specimens removed during
surgery. METHODS AND RESULTS: Specimens were mounted on a myograph and relaxes
through either acetylcholine, a muscarinic agonist that stimulates endothelial
nitric oxide production, or sodium nitroprusside, an endothelium-independent
vasodilator. Studies were performed under control conditions and after
dipyridamole which potentiated in a concentration-dependent manner the
vasorelaxation induced both by acetylcholine and sodium nitroprusside, indicating
an endothelium-independent mechanism of action. The contribution of nitric oxide
to the relaxation produced by acetylcholine was confirmed by N-monomethyl-L
arginine, a nitric oxide synthase inhibitor. In contrast, indomethacin, a cyclo
oxygenase inhibitor, was ineffective, indicating that prostacyclin stimulation
could not explain the effect of dipyridamole. CGS 21680 C, an A(2)-selective
adenosine receptor agonist insensitive to tissue deaminase, did not influence the
relaxations induced by acetylcholine, suggesting that interference with adenosine
metabolism was not implicated in the potentiating action of dipyridamole.
CONCLUSIONS: Dipyridamole potentiated the vasorelaxing effect of acetylcholine
and sodium nitroprusside in human subcutaneous arterioles; neither prostacyclin
stimulation nor A(2) adenosine receptor stimulation could explain this effect.
The data are consistent with an increase in intracellular cyclic 3' 5'-guanosine
monophosphate levels secondary to the phosphodiesterase-inhibiting properties of
the drug.
PMID- 10684419
TI - Effect of Oxygen Free Radicals on Cardiac Contractile Activity and Sarcolemmal
Na(+)-Ca(2+) Exchange.
AB - BACKGROUND: Although oxygen free radicals have been shown to induce myocardial
cell damage and cardiac dysfunction, the exact mechanism by which these radicals
affect the heart function is not clear. Since the occurrence of intracellular
Ca(2+) overload is critical in the genesis of cellular damage and cardiac
dysfunction, and since the sarcolemmal Na(+)-Ca(2+) exchange is intimately
involved in Ca(2+) movements in myocardium, this study was undertaken to examine
the effects of oxygen free radicals on the relationship between changes in
cardiac contractile force development and sarcolemmal Na(+)-Ca(2+) exchange
activity. METHODS AND RESULTS: Isolated rat hearts were perfused with a medium
containing xanthine plus xanthine oxidase for different times, and changes in
contractile force as well as sarcolemmal Na(+)-(2+) exchange activity were
monitored. Perfusion of the heart with xanthine plus xanthine oxidase resulted in
a transient increase followed by a marked decrease in contractile activity; the
resting tension was markedly increased. The xanthine plus xanthine oxidase
induced depression in developed tension, rate of contraction, and rate of
relaxation, except the transient increase in contractile activity, was prevented
by the addition of catalase, but not by superoxide dismutase, in the perfusion
medium. A time-dependent depression in sarcolemmal Na(+)-Ca(2+) was also evident
upon perfusing the heart with xanthine plus xanthine oxidase. This depression in
Na(+)-dependent Ca(2+) uptake was associated with a decrease in the maximal
velocity of reaction without any changes in the affinity of Na(+)-Ca(2+)
exchanger for Ca(2+). The presence of catalase, unlike superoxide dismutase,
prevented the decrease in sarcolemmal Na(+)-Ca(2+) exchange activity in hearts
perfused with xanthine plus xanthine oxidase. CONCLUSIONS: The results support
the view that a depression in the sarcolemmal Na(+)-Ca(2+) exchange activity may
contribute to the occurrence of intracellular Ca(2+) overload and subsequent
decrease in contractile activity. Furthermore, these actions of xanthine plus
xanthine oxidase in the whole heart appear to be a consequence of H(2)O(2)
production rather than the generation of superoxide radicals.
PMID- 10684420
TI - Reduction of Myocardial Necrosis After Glycosaminoglycan Administration: Effects
of a Single Intravenous Administration of Heparin or N-Acetylheparin 2 Hours
Before Regional Ischemia and Reperfusion.
AB - BACKGROUND: We determined if a single administration of heparin or
nonanticoagulant N-acetylheparin could reduce myocardial injury resulting from a
90-minute occlusion of the left circumflex coronary artery (LCX) and 6 hours of
reperfusion in the anesthetized canine. METHODS AND RESULTS: Heparin (2 mg/kg), N
acetylheparin (2 mg/kg), or vehicle, 0.9% sodium chloride (control), was
administered intravenously to separate groups of animals 2 hours before LCX
occlusion. To ensure parity of LCX ischemia, only animals with ischemic zone
regional blood flow < 0.16 mL/min/g tissue were included in the final analysis.
Hemodynamics did not differ among the three study groups. Infarct size as a
percentage of the left ventricular area at risk was obtained for each group.
Myocardial infarct size was 43.0 +/- 3.9% in the vehicle, 28.8 +/- 5.8% in the
heparin (P <.05 vs vehicle) and 24.7 +/- 4.6% (P <.05 vs vehicle) in the N
acetylheparin-treated animals. CONCLUSIONS: Pretreatment with heparin or its
nonanticoagulant derivative, N-acetylheparin, provides significant protection to
the regionally ischemic and reperfused canine myocardium independent of either
plasma glycosaminoglycan concentration or alterations in the coagulation system.
PMID- 10684421
TI - Class III Antiarrhythmic Effects of Dofetilide in Rabbit Atrial Myocardium.
AB - BACKGROUND: Dofetilide is a new class III antiarrhythmic agent with demonstrated
efficacy in ventricular and atrial tachyarrhythmias. We investigated its class
III actions and their modulation by stimulation rate in rabbit atrial myocardium.
METHODS AND RESULTS: Standard microelectrode techniques were used to record
action potentials from rabbit atrial tissue at varying stimulation rates.
Dofetilide produced a dose-dependent prolongation of action potential duration at
concentrations from 1 nM to 1 uM at an interstimulus interval of 1000 ms. Action
potential duration at 90% repolarization (action potential duration) was
prolonged from 116 +/- 11.7 ms in control solutions to 13.9 ms at 1 nM dofetilide
and 186 +/- 49.3 ms at 1 uM dofetilide (P <.05 for 1 nM vs control; P <.01 for 1
uM vs control). Reduction of interstimulus interval to 500 ms has no significant
effect on action potential duration prolongation by dofetilide (P <.05 for 1 nM
vs control; P <.01 for 1 uM vs control). Reduction of interstimulus interval to
500 ms had no significant effect on action potential duration prolongation by
dofetilide. At faster rates than this, and particularly at an interstimulus
interval less than 330 ms, a marked "reverse rate dependence" of the class III
effect was observed. Specifically, the high therapeutic concentration of 10 nM
showed no effect on action potential duration at interstimulus interval of 250 ms
or 200 ms, and even at a concentration of 30 nM, the small class III effect was
no longer statistically significant at these rates. CONCLUSIONS: Dofetilide
prolongs action potential duration in rabbit atrial myocardium, but this effect
is significantly attenuated at stimulation rates above 2 Hz.
PMID- 10684422
TI - Reduction of Carnitine Content by Inhibition of Its Biosynthesis Results in
Protection of Isolated Guinea Pig Hearts Against Hypoxic Damage.
AB - BACKGROUND: 3-(2,2,2-trimethylhydrazinium) propionate (THP or mildronate) is an
inhibitor of carnitine biosynthesis. This study was carried out to determine
whether feeding of guinea pigs with THP results in decreased myocardial-free
carnitine content and, as a result, attenuates hypoxic damage in isolated and
paced work-performing hearts. METHODS AND RESULTS: Guinea pigs were administered
either distilled water of 100 mg THP/kg/day orally for 10 days. The treatment
resulted in about a 50% decline in myocardial-free carnitine content, from 11.1
+/- 0.2 (n = 5) to 5.6 +/- 0.2 (n = 5) uM/g dry weight of the heart. The left
ventricular contractile function of the hearts was measured during normoxic
perfusion (PO(2) = 590 mmHg), hypoxic perfusion (PO(2) = 149 mmHg), and
reperfusion (PO(2) = 590 mmHg). In both untreated and THP-treated groups, the
rate of development of intraventricular pressure (+dP/dt) under normoxic
perfusion was similar; however, +dP/dt declined to about 10% of the initial rate
within 20 minutes of hypoxic perfusion. In the THP-treated group of hearts, the
initial decline was slower than that of the untreated animal hearts. After 20
minutes of normoxic reperfusion following 60 minutes of hypoxic perfusion, the
recovery of +dP/dt and -dP/dt was greater in the THP-treated group than in the
untreated group. The elevation of end-diastolic pressure during hypoxia was
completely reversed by normoxic reperfusion of the THP-treated group but not in
the untreated group. Mitochondria isolated from hearts from the THP-treated group
after normoxic reperfusion following hypoxic perfusion exhibited better
respiratory function than those from untreated hearts. CONCLUSIONS: The data
suggest that feeding guinea pigs with THP results in reduced myocardial-free
carnitine content and attenuation of hypoxic and reperfusion injury in isolated
hearts.
PMID- 10684423
TI - Characterization of Magnesium Sulfate as an Antiarrhythmic Agent.
AB - BACKGROUND: Recently, intravenous magnesium therapy has been used for the
treatment of ventricular arrhythmias, but data to establish a causal link between
the electrophysiological properties and the antiarrhythmic actions are lacking.
METHODS AND RESULTS: The acute antiarrhythmic effect of magnesium sulfate was
assessed using epinephrine-, digitalis-, and coronary ligation-induced canine
ventricular arrhythmia models. The intravenous administration of magnesium
sulfate (100 mg/kg) reduced the incidence of the ventricular arrhythmias of all
models. The antiarrhythmic effect on the epinephrine-induced arrhythmia was
potent and long-lasting, while those on the other arrhythmia models were weak and
transient. The direct cardiovascular effects were assessed using the canine
isolated, blood-perfused sinus node, papillary muscle, and atrioventricular node
preparations. The intracoronary administration of magnesium sulfate (0.1-30 mg)
suppressed sinoatrial automaticity and ventricular contraction, while it
increased atrio-His and His-ventricular conduction time, coronary blood flow, and
the duration of monophasic action potential in a dose-dependent manner. The
effects on His-ventricular conduction and monophasic action potential duration
were less potent compared with the other cardiovascular effects. CONCLUSIONS:
These results suggest that magnesium sulfate possesses multiple
electrophysiological properties and that the effects related to the calcium
channel inhibition may be the most relevant for the antiarrhythmic actions.
PMID- 10684424
TI - Cardiac Arrest Associated With Combination Cisapride and Itraconazole Therapy.
AB - We report a case of cardiac arrest associated with cisapride in combination with
itraconazole and provide a brief review of pertinent literature. Cisapride
(Propulsid; Janssen Pharmaceuticals, Titusville, NJ), a gastrointestinal
prokinetic drug, has recently been reported to prolong the QT interval.
Itraconazole, an oral antifungal agent, is an inhibitor of cytochrome P450
(CYP3A4) metabolism and may elevate serum drug levels of compounds metabolized by
this pathway. A 31-year-old woman had a witnessed cardiac arrest while taking the
combination of cisapride and itraconazole. Following resucitation, the prolonged
QT interval returned to normal after withdrawal of both agents. Echocardiography
and cardiac catheterization were within normal limits; electrophysiologic testing
failed to induce ventricular tachycardia/ventricular fibrillation. She has had no
documented arrhythmias since the arrest. This combination can now be added to a
growing list of drugs that may cause torsades de pointes and sudden cardiac
death.
PMID- 10684425
TI - The Role of Digoxin in the Treatment of Chronic Congestive Heart Failure.
AB - It is now well established that digoxin is an effective drug for the treatment of
heart failure. Since treatment with angiotensin-converting enzyme (ACE)
inhibitors reduces mortality in congestive heart failure, digoxin should be added
to ACE inhibitors in patients with moderate or severe heart failure. The
beneficial effects of digoxin may be due, in part, to its well-documented
sympathoinhibitory effects that can avert the adverse effects of long-term
excessive sympathetic adrenergic stimulation in heart failure.
PMID- 10684426
TI - Amiodarone and Homogeneity of Ventricular Repolarization and Refractoriness.
PMID- 10684427
TI - Effects of Various Modalities of Oral Furosemide Administration in Mild or Severe
Congestive Heart Failure.
AB - BACKGROUND: This study evaluated the optimal formulation (tablet vs solution) and
frequency (once vs twice daily) of maintenance oral furosemide in compensated
congestive heart failure (CHF). METHODS AND RESULTS: Eighteen patients with mild
(group 1) and 18 with severe (group 2) CHF were studied. On 2 consecutive days
each patient's individual fixed oral furosemide daily dosage was administered in
tablet or solution in a crossover design. In an additional study, 14 patients
with severe CHF received the daily dosage in tablet or solution form in two
divided doses. Pharmacokinetic data were obtained in six randomly allocated
patients of each group, during the once daily administration periods of either
formulation. Twenty-four-hour urinary sodium and 12-hour volume were
significantly greater in group 1 following furosemide solution versus tablets. In
group 2, all parameters were comparable in response to single identical doses in
tablets or solution, as well as to once versus twice daily administration of
either formulation. These results coincided with a higher C(max) and a shorter
t(max) following solution. CONCLUSIONS: A once-daily oral furosemide solution is
more effective than the same dosage in tablet form in patients with mild, but not
those with severe, CHF. In patients with severe CHF, the natriuretic and diuretic
effects are similar whether oral furosemide in tablet or solution is administered
in a once or twice daily schedule.
PMID- 10684428
TI - Influence of ACE Inhibition on Fluid Metabolism in Chronic Heart Failure and Its
Pathophysiologic Relevance.
AB - BACKGROUND: In congestive heart failure with water retention, subtraction of body
fluid by ultrafiltration causes greater diuresis and clinical improvement in
patients who are angiotensin-converting enzyme (ACE)-inhibited, suggesting an
influence of ACE inhibitors on fluid metabolism. METHODS AND RESULTS: Patients
with moderate congestive heart failure were subjected to ultrafiltration (around
2000 mL) and followed up for 3 months. Usual outpatient therapy, consisting of
digoxin, furosemide, and ACE inhibitors (18 patients, group A) and of digoxin and
furosemide only (18 patients, group B), was continued throughout the trial.
Hemodynamics, renal function, body fluid and electrolytes, plasma norepinephrine,
renin activity, aldosterone, and plasma volume were monitored. At 30 and 90 days
after ultrafiltration, hormones, renal function, functional capacity (based on
cardiopulmonary tests), and extravascular lung water (chest radiograph score)
were determined. Soon after ultrafiltration, body weight, plasma volume, and
diuresis were reduced (hypovolemia) and hormones were raised (reaction to
hypovolemia). In the next 4 days, all these variables reverted to the pre
ultrafiltration values in group B; in group A diuresis and plasma volume
recovered, body weight was still reduced, and hormones became lower than
baseline. These changes persisted in the next 3 months. An early reduction of
extravascular lung water continued long term in group A only, associated with
increase of exercise tolerance time and oxygen uptake and decrease of the dead
space/tidal volume ratio. CONCLUSIONS: In congestive heart failure, ACE
inhibition persistently prevented fluid accumulation once the excess of body
fluid had been withdrawn with a nonpharmacologic method, resulting in sustained
improvement in functional capacity. Reduction in circulating norepinephrine,
aldosterone, and renin did not seem to be the cause but the consequence of this
action, whose mechanisms remain undefined.
PMID- 10684429
TI - Differential Electrophysiologic Effects of Chronically Administered Amiodarone on
Canine Purkinje Fibers versus Ventricular Muscle.
AB - BACKGROUND: Acute and chronic treatment with amiodarone has been reported to
cause different electrocardiographic changes in patients. The cellular
electrophysiologic effects of chronic administration (50 mg/kg/day orally for 6
weeks) and acute superfusion (5 uM in the tissue bath) of amiodarone were
therefore studied in dog cardiac ventricular muscle and Purkinje fibers using
conventional microelectrode techniques. METHODS AND RESULTS: During stimulation
at 1 Hz, chronic amiodarone treatment lengthened the ventricular muscle action
potential duration (APD) from 227.8 +/- 6.3 ms (n = 20) to 262.3 +/- 5.2 ms (n =
21; P <.01), but shortened that of Purkinje fibers from 337.6 +/- 9.2 (n = 21) to
308.3 +/- 7.1 (n = 19; P <.05). Acute superfusion of 5 uM amiodarone in cardiac
tissue obtained from chronically treated dogs did not change ventricular muscle
APD but shortened Purkinje fiber AP from 309.7 +/- 13.6 ms to 281.9 +/- 11.9 ms
(n = 8; P <.05). Neither the chronic nor the acute amiodarone exposure prevented
the APD shortening in ventricular muscle evoked by 10 uM pinacidil, suggesting
that amiodarone does not interfere with the ATP-dependent potassium channels. The
normal difference in APD between ventricular muscle and Purkinje fibers in
untreated, control preparations was 110 ms but decreased to 46 ms in fibers
obtained from dogs chronically treated with amiodarone and increased to 185 ms in
fibers obtained from dogs chronically treated with amiodarone and increased to
185 ms in the presence of 30 uM sotalol, a class III antiarrhythmic drug used for
comparison. Amiodarone (5 uM) applied directly abolished early
afterdepolarizations (EADs) (induced by 1 uM dofetilide + 20 uM BaCl(2) + 2 mM
CsCl) in 5 of 6 experiments and caused strong use-dependent V(max) block with
relatively fast onset kinetics (rate constant = 1.23 +/- 0.13 AP(-1), n = 5) and
offset (time constant = 364 +/- 62.5 ms, n = 5). After chronic amiodarone
treatment, in contrast with acute sotalol application (30 uM), no reverse use
dependent effect was observed on the APD in Purkinje fibers. CONCLUSIONS: These
results provide further evidence that amiodarone differs from other recognized
class III antiarrhythmic drugs (ie, it is a mixed type agent with acute fast
kinetic class I [type B] and a unique class III antiarrhythmic action
characterized by decreased dispersion of APDs between ventricular muscle and
Purkinje fibers). Amiodarone can abolish EADs unlike other class III agents that
are usually associated to induction of EADs. These features might be responsible
not only for the antiarrhythmic efficacy, but also for the relative safety (low
incidence of torsade de pointes) of amiodarone in clinical settings.
PMID- 10684430
TI - Cardioprotective Effects of Red Blood Cells on Ischemia and Reperfusion Injury in
Isolated Rat Heart: Release of Nitric Oxide as a Potential Mechanism.
AB - BACKGROUND: Circulating cells influence myocardial function during ischemia and
reperfusion, (eg, neutrophils exacerbate, and platelets protect the myocardium
from deterioration). This study was designed to determine the role of red blood
cells on myocardial function following ischemia and reperfusion in isolated rat
hearts. METHODS AND RESULTS: Exposure of buffer-perfused hearts to 40 minutes of
total ischemia followed by 30 minutes of reperfusion resulted in myocardial
dysfunction and injury, indicated by decrease in the force of cardiac contraction
(FCC, -25 +/- 4%), increase in the coronary perfusion pressure (CPP, +20 +/- 3%)
and decrease in myocardial superoxide dismutase (SOD, 2.5 +/- 0.2 vs 3.5 +/- 0.4
U/mg protein in sham ischemic hearts, P <.05). Perfusion of the hearts with
washed rat red blood cells showed significant protective effects against ischemia
and reperfusion, indicated by minimal change in FCC (-10 +/- 4%) and CPP (+3 +/-
3%) (both P <.01 vs buffer alone perfused hearts) and preservation of myocardial
SOD activity (2.8 +/- 0.4 U/mg protein, P <.05 vs buffer alone perfused hearts).
The cardioprotective effects of red blood cells were attenuated when the red
blood cells were preincubated with the nitric oxide blood cells were attenuated
when the red blood cells were preincubated with the nitric oxide blood cells were
attenuated when the red blood cells were preincubated with the nitric oxide
synthase inhibitors N(omicron)-nitro-l-arginine (l-NNA, 5 x 10(-4)M) or
N(omicron)-nitro-l-arginine methyl ester (l-NAME, 5 x 10(-4)M) at 37 degrees C
for 60 minutes before perfusion of the heart. Perfusion of hearts with the nitric
oxide precursor l-arginine (2 x 10(-4)M) also exerted significant protective
effects on FCC ( - 14 +/- 4%), CPP (+12 +/- 3%) and myocardial SOD activity (2.9
+/- 0.2 U/mg protein) following ischemia and reperfusion. In other studies,
washed rat red blood cells expressed nitric oxide synthetase activity which was
inhibited by both l-NNA and l-NAME. CONCLUSIONS: These results suggest that red
blood cells exert cardioprotective effects against ischemia and reperfusion at
least in part by the l-arginine-nitric oxide pathway in isolated rat hearts.
PMID- 10684431
TI - Effect of Dofetilide and d-Sotalol on the ATP-Sensitive Potassium Channel of
Rabbit Ventricular Myocytes.
AB - BACKGROUND: The ability of dofetilide and d-sotalol to maintain their class III
action during ischemia is uncertain. We investigated the effect of these two
drugs on the ATP-sensitive potassium channel (I(KATP)), which plays a major role
in ischemia-induced action potential duration shortening. METHODS AND RESULTS:
The activity of I(KATP) channels was studied in excised membrane patches of
single ventricular myocytes, obtained by standard enzymatic dissociation
techniques from New Zealand white rabbits. Dofetilide demonstrated a dose
dependent block of I(KATP) with an EC(50) of 51 +/- 1 uM in inside-out patches,
Its ability to block the channel was substantially less when applied to the
external membrane surface. d-Sotalol significantly blocked I(KATP) (42%
reduction) at a concentration of 10 uM but not at 1 uM. As with dofetilide, its
ability to block I(KATP) was reduced when applied externally. CONCLUSIONS: We
conclude that dofetilide and d-sotalol block the ATP-sensitive potassium channel,
but dofetilide does so only at concentrations much greater than those required
for block of the delayed rectifier potassium channel. d-Sotalol in contrast shows
modest blockade of I(KATP) at concentrations in the upper range of those seen
during its clinical use.
PMID- 10684432
TI - Tedisamil Attenuates Ventricular Fibrillation in a Conscious Canine Model of
Sudden Cardiac Death.
AB - BACKGROUND: The electrophysiologic and antifibrillatory properties of tedisamil
(KC-8857;3,7-di-(cyclopropylmethyl)-9,9-tetramethylene-3,7-diazabicyclo[3.3.1]
nonane dihydrochloride) were studied in a conscious canine model of sudden
cardiac death. METHODS AND RESULTS: Three to five days after surgically induced
myocardial infarction (2-hour occlusion of the left anterior descending coronary
artery), animals were subjected to programmed electrical stimulation to identify
those at risk for ischemia-induced ventricular fibrillation. Sixty minutes after
tedisamil (10 mg/kg, administered orally) PES was repeated. Tedisamil increased
the ventricular effective refractory period from 106 +/- 6 to 134 +/- 7 ms (P
<.05) compared to placebo treatment, which did not alter the ERP (123 +/- 6 to
116 +/- 5 ms). Tedisamil prolonged the QTc interval, from a predrug value of 308
+/- 14 to 327 +/- 14 ms, postdrug. The extent of the surgically induced anterior
wall myocardial infarct did not differ between groups, tedisamil, 29 +/- 2%, and
placebo, 28 +/- 2% of the left ventricle. CONCLUSIONS: Tedisamil conferred
protection against ischemia induced ventricular fibrillation; 7 of 10 tedisamil
treated dogs survived, compared to 4 of 14 surviving in the vehicle treated group
(P <.05). Although we observed instances of vomiting and/or diarrhea in several
dogs after a single oral administration of tedisamil, the data indicate that oral
administration of tedisamil provides protection from ischemia-induced ventricular
fibrillation in the postinfarcted conscious canine. The mechanism by which
tedisamil achieves its antifibrillatory effect may be related to its ability to
prolong the ERP of the ventricular myocardium without altering ventricular
conduction velocity.
PMID- 10684433
TI - Vasodilation Effects and Action Mechanisms of TMB-8 on Basilar Artery in Rabbits.
AB - BACKGROUND: 8-(N,N'-diethylamino)-n-octyl-3,4,5-trimethoxybenzoate (TMB-8) is a
potent Ca(2+)-antagonist that can prevent/treat ischemic stroke and inhibit the
contractility of smooth, skeletal, and cardiac muscles. Further studies are
warranted to elucidate the efficacy of TMB-8 on rabbit basilar artery preparation
and its action mechanisms on vascular smooth muscle cell cultures. METHODS AND
RESULTS: Effects of TMB-8 on the contractility of rabbit's basilar artery in
vitro and those on intracellular free Ca(2+) concentrations, [Ca(2+)](i), were
studies with isolated organ bath and Fura-2 methods. Histamine-induced
concentration-response curves were shifted by TMB-8 in a mixed manner whereas
those of norepinephrine and KCl were shifted in a non-competitive manner. In the
presence of nifedipine or in a Ca(2+)-free medium, 2,5-di(tert-butyl)-1,4
benzohydroquinone (BHQ) (10 uM) induced an immediate transient contraction in
rabbit basilar artery, whereas ryanodine showed a slow, weak, sustained
contraction, followed by a weak, sustained relaxation. TMB-8 (30 uM)
significantly inhibited these contractions of BHQ and ryanodine. Further,
aminophylline enhanced the inhibitory action of TMB-8 on vasocontractions,
suggesting that TMB-8's inhibitory actions may be related to the increase of cAMP
level. The muscle contraction induced by BHQ was enhanced by pretreatment of the
artery ring with TMB-8 for 15 minutes and then TMB-8 was rinsed out. These
results indicate that TMB-8 pretreatment can increase Ca(2+) sequestration into
sarcoplasmic reticulum, which leads to a larger subsequent Ca(2+) release by BHQ.
KCl-induced increase of [Ca(2+)](i) in vascular smooth muscle cells was reduced
when the cells were bathed in the medium containing nifedipine. TMB-8 made
further reduction on KCl-induced [Ca(2+)](i) increase in nifedipine-containing
solution, which had already blocked the voltage-operated Ca(2+) entry.
CONCLUSION: These results indicate that (a) TMB-8 can enhance Ca(2+)
sequestration into sarcoplasmic reticulum, which leads to a larger amount of
Ca(2+) that can be released by BHQ; (b) TMB-8 can inhibit KCl-induced muscle
contraction caused by the reduction of [Ca(2+)](i) through saturation of Ca(2+)
inside the sarcoplasmic reticulum rather than a direct blockade of Ca(2+)-influx
at cell membrane site; and (c) TMB-8 increases cAMP, which enhances Ca(2+) uptake
into the sarcoplasmic reticulum.
PMID- 10684434
TI - Controlling Paroxysmal Atrial Fibrillation by a Combination of Amiodarone and
Flecainide: Description of a Case With 15-Year Follow-up.
AB - A 77-year-old man with no known cardiac disease has had paroxysmal atrial
fibrillation for 35 years with disabling symptoms and poor exercise tolerance
when not in sinus rhythm, and he did not respond to conventional therapy. Fifteen
years ago he was placed on amiodarone. His arrhythmia converted to atrial flutter
with a flutter rate below 200 beats/min; DC cardioversion at 3 months led to
transient sinus rhythm. At 5 months he converted spontaneously to sinus rhythm
and had very few recurrences until 4 years later when he began to experience
further frequent recurrences when the dose was reduced from 400 mg/day to 200
mg/day. Redosing at the higher dose led to skin discoloration; amiodarone was
then replaced with sotalol, which the patient did not tolerate. After 9 months
with efforts to rate control with various agents, amiodarone was reintroduced at
400 mg/day, which achieved full control, but to obviate the development of skin
changes, flecainide was added at a dose of 100 mg twice a day, and the dose of
amiodarone was gradually reduced to 200 mg/day. This combination regimen has
produced no side effects or organ toxicity, although a degree of hypogonadism
developed. It responded well to testosterone replacement. On the combination
regimen, there have been no symptomatic arrhythmia recurrences over 8 years.
Amiodarone and flecainide may have additive or synergistic effects in maintaining
sinus rhythm in atrial fibrillation; the antiarrhythmic property of amiodarone is
likely to minimize or nullify the proarryhthmic reactions of flecainide during
combination therapy. This combination regimen may allow the extension of the use
of flecainide in controlling refractory atrial flutter and fibrillation in
patients with structural cardiac disease. The efficacy and safety of the
combination regimen of the two drugs should be addressed in controlled clinical
trials.
PMID- 10684436
TI - Class III Antiarrhythmic Drugs: Simple versus Complex Molecules for Controlling
Cardiac Arrhythmias.
PMID- 10684435
TI - Time Frame of Ischemic Preconditioning: Is It Clinically Relevant?
PMID- 10684437
TI - Cerivastatin, a New Potent Synthetic HMG Co-A Reductase Inhibitor: Effect of 0.2
mg Daily in Subjects With Primary Hypercholesterolemia.
AB - BACKGROUND: Reduction of serum cholesterol, most notably low-density lipoprotein
cholesterol is associated with reductions in cardiovascular morbidity and
mortality. Statins have been shown to effectively reduce low-density lipoprotein
cholesterol via inhibition of the hydroxymethyl-coenzyme A (HMG-CoA) reductase.
Cerivastatin is the most potent HMG-CoA reductase inhibitor currently under study
in the United States. METHODS AND RESULTS: A parallel group, randomized, placebo
controlled, double-blind, multicenter study was conducted to compare the efficacy
and safety of three different dosing regimens of 0.2 mg/day of cerivastatin, a
new HMG-CoA reductase inhibitor, in patients with hypercholesterolemia. After a
10-week diet-placebo lead-in period, 319 patients with low-density lipoprotein
cholesterol >160 mg/dL were randomized to 4 weeks of treatment with one of the
following regimens: cervastatin 0.1 mg twice daily, cerivastatin 0.2 mg once
daily with the evening meal, cerivastatin 0.2 mg once daily at bedtime or
placebo. All three active treatment groups produced statistically significant (P
<.05) changes compared to aseline and placebo in total cholesterol (0.1 mg twice
daily ?_18.9%; 0.2 mg once daily with the evening meal: ?_21.9%; 0.2 mg once
daily at bedtime: ?_22.1%; placebo: 0.0%), low-density lipoprotein cholesterol
(0.1 mg twice daily: ?_25.7%; 0.2 mg once daily with the evening meal: ?_29.4%;
0.2 mg once daily at bedtime: ?_30.4%; placebo: 1.4%) and high-density
lipoprotein cholesterol (0.1 mg twice daily: 5.3%; 0.2 mg once daily with the
evening meal: baseline and placebo, were also reduced by all active treatments
(0.1 mg twice daily: ?_11.6% [P =.05]; 0.2 mg once daily with the evening meal:
?_11.6% [P =.05]; and 0.2 mg at bedtime: ?_10.9% [P =.07]). The percentage change
in total cholesterol and low-density lipoprotein cholesterol after 4 weeks of
therapy for the once-daily cerivastatin groups was statistically significantly
greater (P <.05) than the cerivastatin twice daily regimen. A treatment responser
was seen by 1 week of therapy and was maximal by 3 weeks. The drug was well
tolerated in all three dosing regimens and resulted in no significant increase in
biochemical or clinical side effects compared to placebo. CONCLUSION:
Cerivastatin is a novel, highly potent, well-tolerated HMG-CoA reductase
inhibitor that produces low-density lipoprotein cholesterol reductions of
approximately 30% when administered at 0.2 mg once a day in the evenings.
PMID- 10684438
TI - Long-term Treatment With Pravastatin Alone and in Combination With Gemfibrozil in
Familial Type IIB Hyperlipoproteinemia or Combined Hyperlipidemia.
AB - BACKGROUND: Pravastatin inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase.
It prevents mevalonate synthesis, reducing endogenous cholesterol production, and
reduces cholesterol content in the liver, thus resulting in a down-regulation of
low-density lipoprotein receptor production. Gemfibrozil reduces very low-density
lipoprotein production and low-density lipoprotein-cholesterol level and
increases very low-density lipoprotein catabolism. Therefore, it was suggested
that combination therapy with both drugs could effect greater reduction of
cholesterol levels as compared to pravastatin alone. The present study was
carried out to evaluate the efficacy and safety of pravastatin as a monotherapy
or in combination with gemfibrozil in the treatment of patients with familial
type IIb hyperlipoproteinemia or familial combined hyperlipidemia. METHODS AND
RESULTS: Forty-one patients were included in the study. All patients initially
followed 6 weeks of hypolipidemic diet; subsequently they were randomized and
received either 20 mg once daily of pravastatin alone (n = 13) or 20 mg of
pravastatin together with 600 mg of gemfibrozil twice daily (n = 14). As a
control, 14 patients were treated with diet only. The treatment lasted 24 months
and clinical evaluation and laboratory tests were done at given time points. Both
groups of treated patients showed an early reduction (3 months) of total (about
30% P <.01 vs controls), low-density lipoprotein (about 35%, P <.01 vs controls)
and very low-density lipoprotein cholesterol levels (about 18%, P = NS). In
contrast, high-density lipoprotein cholesterol levels increased significantly in
patients treated with pravastatin and gemfibrozil (about 20%, P <.05 vs
controls). Pravastatin treatment alone reduced the level of serum triglycerides
as efficiently as in combination with gemfibrozil. Data showed a sustained
normalization of lipid profile until 24 months. However, this effect was achieved
in patients that had rather low levels of triglycerides. During the treatment we
did not observe any difference in the incidence of possible drug-related side
effects. Severe myopathy or rhabdomyolysis was not observed at the doses of the
drugs used in our study. CONCLUSIONS: Therapy with pravastatin and in combination
with gemfibrozil resulted in significant and sustained normalization of lipid
profile in high-risk patients with familial type IIb hyperlipoproteinemia or
familial combined hyperlipidemia.
PMID- 10684439
TI - d-Sotalol Induces Marked Action Potential Prolongation and Early
Afterdepolarizations in M but Not Empirical or Endocardial Cells of the Canine
Ventricle.
AB - BACKGROUND: Despite its class III antiarrhythmic actions, experimental and
clinical studies have shown that d-sotalol can also be proarrhythmic; a recent
clinical trial that evaluated d-sotalol in postmyocardial patients (SWORD) had to
be prematurely interrupted because of the excess mortality in the treated group.
Previous studies have demonstrated the existence of a marked heterogeneity across
the ventricular wall; epicardial, endocardial, and M cells have been shown to
display distinct electrophysiologic characteristics and pharmacologic behavior.
The present study was designed to test the hypothesis that M cells are the
primary target for the class III actions of d-sotalol in canine ventricular
myocardium and may contribute to its proarrhythmic effects. METHODS AND RESULTS:
We used standard microelectrode techniques to record transmembrane activity from
endocardial, epicardial, midmyocardial, and transmural strips, isolated from the
canine left ventricle. d-Sotalol (100 uM, 60 minutes of exposure, [K(+)]o = 4 mM)
prolongs the action potential in the three cell types, but more so in M than
epicardial or endocardial cells, especially at the slower rates. At a basic cycle
length of 2000 ms, action potential duration after 90% repolarization increases
from 199 +/- 20 to 247.5 +/- 28 ms in epicardium (n = 10), from 212 +/- 26 to 274
+/- 27 ms in endocardium (n = 11), and from 309 +/- 65 to 533 +/- 207 ms in M
cells (n = 13). d-Sotalol produces a marked steepening of action potential
duration-rate relationships of M cells and an upward shift of restitution of
action potential duration curves, more accentuated in M cells. Early
afterdepolarizations were observed at slow rates (basic cycle lengths > 1000 ms)
in 7 of 13 M cell preparation s(54%) but not in endocardial or epicardial
preparations. A sudden acceleration of the rate could also induce a transient
prolongation of the action potential and early afterdepolarization activity.
CONCLUSION: In canine ventricular tissues, d-sotalol manifests its class III
effects preferentially in the M cells, leading to the development of early
afterdepolarizations and a marked increase in transmural dispersion of
repolarization. The data suggest an important role of M cells in the
proarrhythmic effects of the drug.
PMID- 10684440
TI - The Novel Class III Antiarrhythmic Agent MS-551 Blocks the Cardiac Inward
Rectifier With Greater Potency Than Sotalol or E-4031: Possible Relevance to
Reverse Use Dependence.
AB - BACKGROUND: The tendency for the electrophysiologic effect of class III
antiarrhythmic agents (action potential prolongation) to be diminished at faster
heart rates represents a major drawback of this class of drug and is usually
referred to as "reverse use dependence." A novel class III agent, MS-551, has
recently been reported to exhibit less reverse use dependence than E-4031. We set
out to investigate whether this observation may be due to differential blockade
of the inward rectifier current (i(K1)) by these drugs. METHODS AND RESULTS: We
recorded i(K1) using single channel methods and cell attached patch
configurations, with standard patch clamp technology. Neither E-4031 nor racemic
sotalol in concentrations up to 100 uM had any significant effect on the open
probability or kinetics of i(K1) without altering the single-channel conductance.
Openings to subconductance levels were abolished in three of six patches in which
they had been frequently present in the absence of drug. MS-551 had no effect on
mean channel open time but increased the slower component of the closed time.
CONCLUSIONS: MS-551, unlike E-4031 and sotalol, appears to produce significant
blockade of the inwardly rectifying potassium channel at clinically relevant
concentrations. We propose that this might provide a partial explanation for the
observed differences in their response to rate changes.
PMID- 10684441
TI - Estradiol, Administered Acutely, Protects Ischemic Myocardium in Both Female and
Male Rabbits.
AB - BACKGROUND: The benefits of chronic administration of estrogen to postmenopausal
women are well documented; however, the acute effects of exogenous estradiol on
myocardium after coronary artery occlusion and reperfusion in male and female
animal models are unknown. We tested the influence of acute pretreatment with
estradiol on the development of myocardial necrosis in two protocols, studying
intact anesthetized female and male rabbits. METHODS AND RESULTS: 17beta
estradiol (1 mg) was given 15 minutes before coronary artery occlusion in the
treated groups (n = 10 females, 10 males); control rabbits (n = 11 females, 10
males) received water. All rabbits underwent 30 minutes of coronary artery
occlusion and 4 hours of reperfusion. Myocardial blood flow was similar between
groups at 10 minutes after treatment and during coronary artery occlusion and
reperfusion. Thus estradiol did not increase blood flow. Heart rate and systemic
pressure were also similar between groups. Estradiol levels during coronary
artery occlusion were 1-8 pg/mL in untreated female and male rabbits and 66 +/-
28 (male) and 352 +/- 273 (female) in treated rabbits. Although the size of the
ischemic risk zones was similar in both groups in both protocols, estradiol
treated rabbits of both sexes developed significantly less necrosis. Infarct size
as a percent of the risk region was 10 +/- 1% in female estradiol-treated rabbits
compared with 23 +/- 5% in controls (P <.03) and 16 +/- 4% in estradiol-treated
male rabbits compared with 31 +/- 5% in control males (P =.03). Although male
rabbits had larger infarcts than female rabbits, sex was not a significant
covariate for infarct size. CONCLUSIONS: Estradiol exerts a protective effect on
ischemic myocardium that is not associated with an increase in myocardial blood
flow or alteration in hemodynamics. This study shows that acute administration of
estrogen before coronary artery occlusion reduces infarct size in both male and
female rabbits.
PMID- 10684442
TI - Role of Oxidative Stress in Amiodarone-induced Toxicity.
AB - BACKGROUND: The clinical usefulness of amiodarone for the treatment of cardiac
arrhythmias is limited by multiorgan toxicity, especially pulmonary and hepatic.
There are conflicting reports in the literature regarding the role of free
radicals in the initiation of amiodarone-induced toxicity. We evaluated the
possible oxidative stress in a chronic model that is known to manifest pulmonary
toxicity. METHODS AND RESULTS: A group of 20 Fischer-344 rats were injected with
60 mg/kg/day of amiodarone for 21 days. A control group of 20 animals received
only saline injections. The alveolar macrophages obtained by lung lavage were
incubated with hydroethidine and opsonized green fluorescent zymosan particles to
measure oxidative and phagocytic activities by flow cytometry. Malondialdehyde
levels were measured to assess the extent of lipid peroxidation in lung, liver,
spleen, kidney, and heart. Total phospholipid levels in all the collected tissues
and distribution of phospholipid classes in the lung and the liver were measured.
The levels of amiodarone and its metabolite desethylamiodarone in serum and all
collected tissues were measured by high-performance liquid chromatography. The
phagocytic activity of th emacrophages from treated animals was decreased by 18
22% (P <.03) compared to controls; however, the oxidative activities of control
and treated groups were not significantly different. The tissue malondialdehyde
levels were not significantly different except in the spleen where they increased
after amiodarone treatment (18.2 +/- 1.1 vs 23.7 +/- 2.8 uM/g tissue, P <.0001).
Malondyaldehyde levels were not significantly different when normalized to lipid
phosphorous content. Lung, liver, and spleen showed significantly higher
phospholipid levels in the treated group. The tissue amiodarone and
desethylamiodarone levels in the treated group were highest in spleen followed by
lung, liver, kidney, and heart. CONCLUSIONS: The results show that amiodarone
induced pulmonary and hepatic toxicity is not directly mediated by oxidative
stress; however, increased lipid peroxidation in the spleen, although secondary
to phospholipidosis, may be physiologically significant.
PMID- 10684443
TI - Electrophysiology of Myocardial Cells in the Epicardial, Midmyocardial, and
Endocardial Layers of the Ventricle.
AB - The recent discovery of multiple myocardial cell types in the ventricular wall of
most species has prompted a reevaluation of several electrophysiologic and
electrocardiographic findings. This review briefly presents the salient
electrophysiologic features of myocardial cells in the epicardial, midmyocardial
and endocardial regions of the ventricle. The epicardial action potential
exhibits a prominent notch between phase 1 and phase 2 that results in a spike
and dome configuration. The notch is smaller in midmyocardial cells and absent in
endocardial cells. The action potential notch is due to the presence of a
transient outward current (I(to)), which diminishes in amplitude from the
epicardial to endocardial surfaces. Midmyocardial or "M cells" exhibit
electrophysiologic features intermediate between those of myocardial and
conducting cells. M cells differ from epicardial and endocardial cells primarily
in their response to slowing of the stimulation rate. These cells display an
exaggerated prolongation of action potential duration at moderate to slow rates
of stimulation. The atypical response in M cells reflects decreased levels of the
delayed rectifier K(+) current (I(K)) in this cell type (dV/dt) compared to
epicardial or endocardial cells. These electrophysiologic distinctions contribute
to differences in the responsiveness of the various cell types to pharmacologic
agents and disease. Also, the dispersion of repolarization created between
epicardium and endocardium in the early phases of the action potential, and
between M cells and other ventricular layers during late repolarization, may
explain the J wave and U wave of the electrocardiogram, respectively.
PMID- 10684444
TI - The M Cell.
PMID- 10684445
TI - Efficacy and Safety of Nifedipine Coat-Core versus Amlodipine in Patients With
Mild to Moderate Essential Hypertension: Comparison of 24-Hour Mean Ambulatory
Diastolic Blood Pressure.
AB - BACKGROUND: Calcium channel blockers have been successfully used for the
treatment of hypertension. In this study, the antihypertensive efficacy and
safety of the dihydropyridine calcium channel blockers nifedipine coat-core 30 mg
and amlodipine 5 mg were evaluated. METHODS: This multicenter, double-blind,
prospective, randomized, parallel-arm study compared once daily administration of
nifedipine coat-core 30 mg with once daily amlodipine 5 mg in subjects with mild
to-moderate essential hypertension. A 4-week placebo run-in period was followed
by an 8-week active treatment period. Blood pressure reduction was measured by
ambulatory blood pressure monitoring and casual office blood pressure measured by
mercury sphygmomanometer. RESULTS: Nifedipine coat-core and amlodipine produced
equivalent reductions in mean diastolic blood pressure, as determined by 24-hour
ambulatory blood pressure monitoring. Mean reduction in diastolic blood pressure
was 5.4 mmHg and 5.8 mmHg for nifedipine coat-core and amlodipine, respectively.
Both drugs were well tolerated and neither treatment resulted in a significant
change in heart rate. CONCLUSIONS: Nifedipine coat-core 30 mg once-daily is
comparable to amlodipine 5 mg once-daily for blood pressure reduction.
PMID- 10684446
TI - Urinary NItrotyrosine Content as a Marker of Peroxynitrite-induced Tolerance to
Organic NItrates.
AB - BACKGROUND: Anti-ischemic therapy with nitrovaasodilators as NO-donors is
complicated by the induction of tolerance. When nitrovasodilators are metabolized
to release NO there is a considerable coproduction of oxygen-derived radicals
leading to a diminished cyclic GMP production and to impaired vasomotory
responses. We analyzed in vivo the glyceroltrinitrate-induced generation of
strong oxidative/nitrating compounds contributing to development of tolerance.
METHODS AND RESULTS: In 16 patients we studied the urinary nitrotyrosine
excretion during either (1) placebo control conditions, (2) 2-day nonintermittent
transdermal nitroglycerin administration (0.4 mg/h), (3) 2-day nonintermittent
glyceroltrinitrate administration (0.4 mg/h) along with a continuous infusion of
vitamin C (55 ug/kg/min) as an antioxidant, or (4) with vitamin C but without
glyceroltrinitrate (diminished urinary nitrotyrosine content of 34 +/- 18 ug/day
observed). Glyceroltrinitrate administration augmented urinary nitrotyrosine from
56 +/- 24 (basal) to 186 +/- 32 ug/day (glyceroltrinitrate tolerance).
Coadministration of vitamin C caused complete elimination of tolerance and a
decrease in urinary nitrotyrosine to 130 +/- 28 ug/day. Glyceroltrinitrate
induced formation of oxidants was confirmed in vitro comparing glyceroltrinitrate
induced and peroxynitrite-induced tachyphylaxis in isolated perfused rabbit
hearts and analyzing tolerance-induced inactivation of solbule guanylyl cyclase
in cultured aortic smooth muscle cells. CONCLUSIONS: Augmented urinary
nitrotyrosine excretion during glyceroltrinitrate administration reflects
enhanced formation of peroxynitrite and of nitrotyrosine. Glyceroltrinitrate
induced tolerance is the result of oxidative stress and can be suppressed by
additional antioxidant therapy aimed to prevent glyceroltrinitrate-induced
formation and/or actions of peroxynitrite.
PMID- 10684447
TI - Digoxin's Minimal Inotropic Effect Is Not Limited by Sodium-Calcium Exchange in
the Intact Immature Rabbit Heart.
AB - BACKGROUND: In the intact immature heart, how much digoxin can drive sodium
calcium exchange has not been studied in the context of sodium-calcium exchanger
abundance. METHODS AND RESULTS: The effects of digoxin and low potassium on
contractility in the intact, paced and isovolumically contracting immature rabbit
heart were studied in both the absence and presence of L-type calcium channel
blockade. Without calcium channel blockade, digoxin increased contractility
minimally and only at 10(_6) M/L. In contrast, low potassium (2.2 mM/L)
substantially increased contractility in all experiments, a result indicating
abundant sodium-calcium exchanger activity. During nifedipine-induced calcium
channel blockade, digoxin (10(_6) M/L) allowed modest recovery of contractility,
whereas digoxin and low potassium together allowed complete recovery as assessed
by dP/dt(max); however, all hearts so perfused subsequently developed ventricular
fibrillation, presumably because of calcium overload. CONCLUSIONS: In intact
immature rabbit heart, digoxin can drive sodium-calcium exchange and thus
increase contractility to only a minimal extent. This effect does not appear to
be limited by intrinsic exchanger activity, which appears abundant in this
preparation. Rather, digoxin's inability to drive the sodium-calcium exchanger
may be due to developmental differences in binding to the sodium pump. The sodium
calcium exchanger itself seems capable not only of providing enough intracellular
calcium for normal contraction, but also of overloading the myocardium with
calcium, despite L-type calcium channel blockade.
PMID- 10684448
TI - Nitric Oxide Synthesis Inhibition and Role of P-selectin in Leukocyte Adhesion to
Vascular Tissues.
AB - BACKGROUND: This study was designed to examine the role of P-selectin expression
in leukocyte adhesion to endothelium caused by inhibition of nitric oxide
synthesis. METHODS AND RESULTS: Rat aortic rings were treated with the nitric
oxide synthesis inhibitor N(omicron)-nitro-l-arginine methyl ester (l-NAME) for 2
hours. Parallel sets of aortic rings were pretreated with the nitric oxide
precursor l-arginine or posttreated with a specific monoclonal antibody against P
selectin. Some rings were used for determination of vasoreactivity in response to
norepinephrine and acetylcholine, while other rings were incubated with
autologous unlabeled leukocytes or Biotin-FITC labeled leukocytes for 30 minutes.
Leukocyte adhesion to vascular endothelium was determined by scanning electron
microscopy. l-NAME enhanced the contractile response in response to
norepinephrine, suppressed the relaxant response to acetyleholine, promoted
leukocyte adherence to the endothelium and resulted in P-selectin expression on
the aortic endothelium. Pretreatment of aortic rings with l-arginine reversed the
l-NAME-mediated changes in vasoreactivity in response to norepinephrine and
acetyleholine and attenuated the l-NAME-enhanced leukocyte adhesion to
endothelial intima. P-selectin treatment, on the other hand, had no effect on l
NAME-mediated changes. Intraperitoneal administration of l-NAME resulted in a
significant decrease in plasma nitrite level, a small, but significant, increase
in lung and spleen myeloperoxidase activity, and a significant increase in
leukocyte deposition in lung and spleen. The l-NAME-mediated increase in
myeloperoxidase activity and leukocyte deposition in the spleen, but not in the
lungs, was abolished by treatment of rats with the P-selectin antagonist CY1503
administered 30 minutes prior to l-NAME. CONCLUSIONS: These observations indicate
that a reduction in nitric oxide synthesis enhances leukocyte adhesion to aortic
endothelium and in visceral tissues. While P-selectin expression is evident in
some of the experimental models of leukocyte adhesion to endothelium under
conditions of nitric oxide inhibition, the role of P-selectin expression remains
unclear.
PMID- 10684449
TI - Alternations in beta-Adrenoceptor Mechanisms in Hearts Perfused With Xanthine
Plus Xanthine Oxidase.
AB - BACKGROUND: Although beta-adrenoceptors and adenylyl cyclase are known to be
affected upon exposing cardiac membranes to some oxyradical generating systems,
the results are conflicting. Furthermore, functional significance of alterations
in the beta-adrenoceptor-adenylyl cyclase systems in terms of changes in the
inotropic responses to catecholamines is not clear. METHODS AND RESULTS: The
positive inotropic effect of isoproterenol was augmented on perfusing the
isolated rat hearts with xanthine (X) plus xanthine oxidase (XO) for 5 minutes
but was attenuated by perfusion for 15 minutes. The isoproterenol-stimulated
adenylyl cyclase activity in cardiac membranes showed an increase at 10 minutes
and a decrease at 30 minutes perfusion of hearts with X plus XO. The density of
beta-adrenoceptors in cardiac membraners was reduced after 10 minutes and 30
minutes of perfusion with X plus XO, whereas the affinity of beta-adrenoceptors
was increased after 10 minutes and reduced after 30 minutes. Although beta
adrenoceptors was increased after 10 minutes and reduced after 30 minutes.
Although beta-adrenoceptors were unaltered by 10 minutes of perfusion with X plus
XO, their affinity was increased and density was decreased by 30 minutes of
perfusion. The agonist competition curves using isoproterenol indicated an
increase in the number of coupled receptors in the high affinity state on 10
minutes of perfusion and an increase in the low affinity state of coupled
receptor due to 30 minutes of perfusion with X plus XO. The basal as well as
forskolin-, NaF- and Gpp(NH)p-stimulated adenylyl cyclase activities in cardiac
membranes exhibited an increase after 10 minutes and decrease after 30 minutes of
perfusion with X plus XO. Although the presence of superoxide dismutase plus
catalase in the perfusion medium prevented most of the alterations due to X plus
XO, it did not alter the increased affinity of the beta-adrenoceptor upon
perfusing hearts for 10 minutes with X plus XO. CONCLUSIONS: The results in this
study suggest the biphasic nature of the oxyradical-induced alterations in both
the inotropic responses to catecholamines and the beta-adrenoceptor-mediated
signal transduction mechanism in the heart.
PMID- 10684450
TI - Antiarrhythmic and Arrhythmogenic Actions of Varying Levels of Extracellular
Magnesium: Possible Cellular Basis for the Differences in the Efficacy of
magnesium and Lidocaine in Torsade de Pointes.
AB - BACKGROUND: In recent years, there has been an increasing use of antiarrhythmic
drugs that act predominantly by prolonging myocardial repolarization. An
inevitable electrophysiologic consequence of these drugs is the development of
torsade de pointes as a proarrhythmic reaction. Both intravenous lidocaine and
magnesium sulphate have been used in the acute control of such a proarrhythmia.
Their electrophysiologic mechanisms in this setting are not well defined. METHODS
AND RESULTS: Using the standard microelectrode techniques, the effects of
magnesium (Mg) and lidocaine on action potential duration (APD), and on barium
induced spontaneous action potentials, were studied in canine Purkinje fiber
preparations. The objective was to clarify the direct and indirect effects of
magnesium on triggered activities due to early afterdepolarizations. Superfusion
in media with 0.1 mM Mg and 2.5 mM K produced more pronounced increases in APD
measured at -20mV repolarization time [APD(20)] than those in a solution with 5
mM K. This effect was further enhanced at lower stimulation frequencies. The
striking prolongation of APD(20) by solutions with low potassium concentrations
diminished as the Mg concentration was increased. In solutions with 2.5 mM K, Mg
produced concentration-dependent decreases in APD(20). This effect was greater at
lower stimulation frequencies. Lidocaine at 4.0 x 10(_5) M produced a marked
shortening of the APD in the entire firing frequency of the abnormal automaticity
in a concentration-dependent manner. With 10 mM Mg, such action potentials
appeared only sporadically. Magnesium also decreased the amplitude and the
maximum upstroke velocity of these action potentials. In contrast, lidocaine at
4.0 x 10(-5) M exhibited no significant effects on action potentials due to
barium-induced abnormal automaticity, or on additional depolarizations developing
from the repolarization phase of these action potentials. CONCLUSIONS: The data
indicate that (i) hypomagnesemia may be arrhythmogenic when combined with
hypokalemia and bradycardia leading to a prolongation of the plateau phase of the
action potential, (ii) magnesium administration may suppress triggered activities
mainly by a direct inhibition of the development of triggered potentials, and
(iii) lidocaine may suppress triggered potentials only indirectly by preventing
the development of early afterdepolarizations due to the shortening effect on the
APD. These findings are consistent with the clinical observation of a high
incidence of torsade de pointes in the setting of hypokalemia and hypomagnesemia
introduced by a chronic diuretic therapy. They are also consistent with the
marked effectiveness of intravenous Mg relative to the inconsistent clinical
effects of lidocaine in controlling torsade de pointes.
PMID- 10684451
TI - Restoring Sinus Rhythm in Patients With Atrial Flutter and Fibrillation:
Pharmacologic or Electrical Cardioversion?
AB - Atrial fibrillation and atrial flutter, the most frequently encountered
tachyarrhythmias requiring treatment, have become a major focus for clinical and
basic research in recent years. Restoration and maintenance of sinus rhythmn,
having been shown to improve exercise capacity, alleviate symptoms, and reduce
the incidence of thromboembolic events, may be the optimal management strategy.
Identification of the safest, most efficacious and cost-effective means of
restoring sinus rhythm is necessary prior to the institution of optimal
antiarrhythmic therapy to maintain sinus rhythm. Potential advantages of
pharmacologic compared with electrical cardioversion include lack of need for
general anesthesia and likely lower cost. Pharmacologic conversion include lack
of need for general anesthesia and likely lower cost. Pharmacologic conversion
has been accomplished with drugs that prolong atrial refractorinerss, including
class Ia (quinidine, procainamide, disopyramide), class Ic (flecainide,
propafenone), and class II (sotalol, amiodarone) compounds. The so-called pure
class III agents were created to overcome the blocker side effects of sotalol and
the complex pharmacodynamic profile of amiodarone. Two such agents are
dofetilide, which selectively blocks the rapid component of the delayed rectifier
current (Ikr) and ibutilide, which augments the slow inward sodium current, with
a smaller component of action mediated by the block of Ikr. Reported overall
conversion rates for recent onset atrial fibrillation and atrial flutter were 31%
and 54% for difetilide, respectively, and 29-31% and 38-63%, respectively, for
ibutilide. Proarrhythmia, manifested as polymorphic ventricular tachycardia
requiring cardioversion, was a significant early side effect of both agents. Data
from clinical trtials with these new agents, combined with increasing nowledge of
the electrophysiologic substrate for these arrhythmias, has renewed initerest in
the development of safer, more efficacious class IIIdrugs for atrial fibrillation
and atrial flutter conversion.
PMID- 10684453
TI - Reflections on Recent Clinical Trials in Patients With Heart Failure and Those
With Reduced Ventricular Function.
PMID- 10684452
TI - Increase in AT1 Receptors as a Mechanism of ACE Inhibition-induced Cough.
PMID- 10684454
TI - Effects of Phentolamine on Responses to PAMP in the Hindquarters Vascular Bed of
the Rat.
AB - BACKGROUND: Responses to proadrenomedullin NH(2)-terminal 20 peptide (PAMP), a
novel hypotensive peptide formed from preproadrenomedullin, and the effects of
inhibition of adrenergic vasomotor tone with the alpha-receptor antagonist,
phenolamine, on responses to PAMP were investigated in the systemic and
hindquarters vascular bed of the rat. METHODS AND RESULTS: Intravenous injections
of PAMP decreased systemic arterial pressure and in the hindquarters vascular bed
of the rat under conditions of controlled hindquarters blood flow, intra-arterial
injections of PAMP decreased perfusion pressure in a dose-related manner.
Following administration of the alpha receptor blocking agent, phenotlamine,
systemic depressor and hindquarters vasodilator responses to PAMP were not
significantly decreased, whereas phentolamine significantly decreased systemic
and hindquarters pressor responses to norepinephrine. Phentolamine had no
significant effect on vasodilator responses to bradykinin, albuterol, or to
nitroglycerin. CONCLUSIONS: The present data show that PAMP has significant
systemic vasodepressor and vasodilator activity in the hindquarters vascular bed
of the rat and suggest that vasodepressor and hindquarters vasodilator responses
to PAMP are not dependent upon the presence of adrenergic vasomotor tone.
PMID- 10684455
TI - Differential Effects of Protein Kinase C Activators and Inhibitors on alpha- and
beta-Adrenoceptor-mediated Positive Inotropic Effect in Isolated Rabbit Papillary
Muscle.
AB - BACKGROUND: A number of novel agents that activate or inhibit protein kinase C
(PKC) in vitro have been developed to evaluate the physiologic role of PKC in
regulation of cellular function. However, most of the PKC inhibitors also affect
the protein kinase A, and the effects of these agents in intact myocardium remain
still controversial. The present study was carried out to examine the effects of
these agents on the positive inotropic effect (PIE) medicated by alpha- and beta
adrenoceptors in isolated rabbit papillary muscle. METHODS AND RESULTS: A potent
PKC activator, phorbol 12, 13-dibutyrate (PDBu) at 10 and 30 nM, induced a
significant PIE. PDBu at 3 nM and higher inhibited the alpha-mediated PIE and
abolished it at 100 nM without affecting the beta-mediated PIE. Phorbol 12
myrisate 13-acetate (PMA) and 1-oleyl-2-acetyl-sn-glycerol (OAG) elicited a
similar selective inhibitory action on the alpha-mediated PIE. The PIE of PDBu
was abolished by chelerythrine and partially inhibited by staurosporine, but H-7
or calphostin-C did not affect the PIE. These PKC inhibitors consistently
inhibited the alpha-mediated PIE by 20-30% at concentrations that they did not
affect the beta-mediated PIE. None of the PKC inhibitors influence the PDBu
induced inhibitory action on the alpha-mediated PIE, an indication that they
failed to reach the site of the inhibitory action of PDBu. CONCLUSION: Selective
modulation by the PKC activators and inhibitors of the alpha-mediated PIE with
little effect on the beta-mediated PIE implies that the activation of PKC has a
physiological relevance to the alpha-mediated PIE. However, the externally
administered PKC activators do not mimic the effect of diacylglycerol that is
generated endogenously by alpha-stimulation. By contrast, externally applied PKC
inhibitors selectively antagonize the alpha-adrenoreceptor-mediated PIE in rabbit
ventricular myocardium.
PMID- 10684456
TI - Pinacidil's Effects on Defibrillation Outcomes: Role of Increased Potassium
Conductance Via the K(ATP) Channel.
AB - BACKGROUND: It has been shown that the inhibition of potassium ion conductance
decreases defibrillation threshold. We postulated that if potassium conductance
is a primary mechanism affecting defibrillation threshold values, then increasing
potassium ion conductance will increase defibrillation values. The primary
objective of this study was to determine if the ATP-dependent potassium (K(ATP))
channel opener pinacidil would increase defibrillation threshold values. The
second objective was to prove that the observed changes were due to potassium
conductance by using the K(ATP) inhibitor, glyburide, to reverse the
electrophysiologic actions of pinacidil. The third objective was to determine if
the electrophysiology action sof pinacidil correlate with changes in
defibrillation threshold value. METHODS AND RESULTS: Domestic farm swine (n = 14)
were anesthetized and intubated. Subsequently, they were instrumented with
monophasic action potential catheters and epicardial defibrillation patches.
Defibrillation threshold values, action potential duration, effective refractory
period, and ventricular fibrillation cycle length were determined at baseline and
during treatment phase 1 and treatment phase 2. Pigs were randomized into 2
groups: group 1 (n = 6) received D(5)W in treatment phase one followed by D(5)W
in treatment phase 2 and group 2 (n = 8) received pinacidil in treatment phase
one followed by the addition of glyburide in treatment phase two. DFT(ED50) did
not change at baseline, treatment phase one or treatment phase two for group 1
(10.5 +/- 2, 11.1 +/- 1.7, 10.5 +/- 1.0 J) or for group 2 (10.1 +/- 2.2, 11.4 +/-
4.2, 11.4 +/- 3.0 J). Electrophysiologic parameters )QRS, effective refractory
period, action potential duration(90), and ventricular fibrillation cycle length)
were not significantly changed from baseline in group 1. In contrast, effective
refractory period, action potential duration(90), and ventricular fibrillation
cycle length significantly decreased at all recorded sites after the
administration of pinacidil in group 2 (range of 7-13%, 6-9%, and 12-17%,
respectively). However, pinacidil did not change the basal level of dispersion in
effective refractory period, action potential duration, and ventricular
fibrillation cycle length during paced rhythm or ventricular fibrillation.
Glyburide reversed pinacidil's electrophysiologic actions. CONCLUSIONS: Pinacidil
does not alter defibrillation threshold, but it reduces effective refractory
period, action potential duration, and ventricular fibrillation cycle length and
does not increase electrical heterogeneity. Therefore, changes in potassium
channel conductance as well as shortening repolarization are unlikely primary
mechanisms for elevating defibrillation threshold.
PMID- 10684457
TI - Local Delivery of an Ultra-short-acting Nitric Oxide-releasing Compound, DMHD/NO,
Is Highly Effective in Inhibiting Acute Platelet-Thrombus Formation on Injured
Arterial Strips.
AB - BACKGROUND: Nitric oxide (NO) plays an important role in modulating platelet
vessel wall interaction following vascular injury. We exampled the effects of
local infusion of an ultra-short-acting NO-releasing compound: NO adduct of N, N'
dimethylhexanediamine (DMHD/NO), sodium nitroprusside, intravenous nitroglycerin,
and aspirin on acute platelet-thrombus formation under conditions of high-shear
blood flow in a rabbit extracorporeal perfusion model. MATERIALS AND METHODS:
Strips of porcine aortic media were perfused in a Badimon chamber with arterial
blood from 20 New Zealand White rabbits for 10 minutes at a shear rate of 1700 s(
1). Thrombus formation was quantified by morphometric analysis of thrombus area.
Effects on collagen-induced platelet aggregation, blood pressure, bleeding time,
and activated clotting time were also examined. RESULTS: DMHD/NO inhibited
thrombus area and platelet aggregation in a dose-dependent manner with a 90%
reduction in thrombus area (0.018 +/- 0.039 vs 0.215 +/- 0.085 mm(2)/mm control,
P <.001) and a 50% reduction in platelet aggregation (4.8 +/- 4.4 vs 9.9 +/- 4.1
Omicron control, P =.04) at the highest dose of 1.0 nM/kg and 100 uM/L,
respectively, without any effects on blood pressure, bleeding time, or activated
clotting time. In contrast, equimolar concentrations of sodium nitroprusside and
intravenous nitroglycerin had significantly reduced effects on thrombus area
compared to DMHD/NO and were associated with significant reductions in blood
pressure and prolongation of bleeding time. Aspirin had no effect on thrombus
area at 1 uM/kg but reduced thrombus area and prolonged bleeding time at 2 and 5
uM/kg. CONCLUSIONS: Local delivery of DMHD/NO produced a 90% inhibition of
experimental acute platelet-thrombosis under high-shear flow conditions without
producing adverse systemic hemodynamic or hemostatic effects. Thus, inhibition of
thrombus formation by local delivery of a rapidly acting NO donor may be an
effective strategy for prevention of arterial injury-induced thrombosis.
PMID- 10684458
TI - Electrophysiologic Effects of the New Class III Antiarrhythmic Drug Dofetilide in
an Experimental Canine Model of Pacing-induced Atrial Fibrillation.
AB - BACKGROUND: Dofetilide is a new class III antiarrhythmic drug currently under
investigation for the treatment of supraventricular arrhythmias in humans.
Dofetilide have been previously shown to be highly effective in terminating and
suppressing reentrant atrial flutter in the experimental canine crush-injury
model, in which its antiarrhythmic efficacy was correlated with prolongation of
wavelength and reduction in dispersion of refractoriness, effects not produced by
the class IA antiarrhythmic drug quinidine. The purpose of this study was to
evaluate the antiarrhythmic efficacy and mechanisms of action of dofetilide in an
experimental model of atrial fibrillation. METHODS AND RESULTS: Dofetilide was
administered intravenously to seven open-chest dogs with acute sustained atrial
fibrillation induced by rapid atrial pacing for up to 4 hours. Mean atrial
effective refractory period (ERP), dispersion of ERP, conduction velocity and
wave-length were determined by multipoint right atrial programmed stimulation and
activation mappin gusing a 56-electrode mapping plaque on the right atrial free
wall. Dofetilide prolonged average ERP by 22% from 104 +/- 13 to 127 +/- 15 ms (P
<.001), prolonged maximum ERP by 11% from 129 +/- 7 to 143 +/- 10 (P <.003), had
no effect on conduction velocity at 200 ms pacing cycle length, slowed conduction
velocity by 16% from 0.89 +/- 12 to 0.75 +/-.17 ms at 150 ms pacing cycle length,
slowed conduction velocity by 16% from 0.89 +/- 12 to 0.75 +/-.17 ms at 150 ms
pacing cycle length (P <.001), increased wavelength by 20% from 93 +/- 7 to 112
+/- 9 mm (P <.01), reduced dispersion of ERP by 24% from 11.4 +/- 2.9 to 8.7 +/-
2.3 (P =.016), and reduced the number of adjacent electrodes with ERP difference
>/=20 ms by 67% from 18.4 +/- 7.1 to 6.1 +/- 4.2 (P <.001). Dofetilide reduced
the number of excitation wavelets (total over three beats) entering the region of
the mapping plaque by 38% from 5.0 +/-.8 to 3.1 +/-.4 (P <.002). Dofetilide
terminated atrial fibrillation in all seven dogs at a mean of 3.4 +/- 2.2 minutes
into the loading infusion and prevented reinduction of atrial fibrillation in all
seven dogs after completion of the loading infusion, while on maintenance
infusion. Time to termination of atrial fibrillation correlated closely with
change in ERP (r = 0.78, P =.036). CONCLUSIONS: Dofetilide was highly effective
in terminating and suppressing sustained pacing induced atrial fibrillation in
this canine model. Time to termination of atrial fibrillation correlated with the
degree of change in ERP produced by dofetilide. The mechanism of termination of
atrial fibrillation by dofetilide appeared to be a progressive reduction and
eventual extinction of re-entrant wavelets. The predominant electrophysiologic
effects of dofetilide were prolongation of ERP and wavelength and a reduction in
dispersion of refractoriness. Dofetilide had little effect on conduction velocity
in this model, except at very short pacing cycle lengths.
PMID- 10684459
TI - Modulation of the Electrophysiologic Actions of E-4031 and Dofetilide by
Hyperkalemia and Acidosis in Rabbit Ventricular Myocytes.
AB - BACKGROUND: E-4031 and dofetilide are new class III antiarrhythmic agents that
inhibit the rapid component of the delayed rectifier potassium channel (I(Kr));
however, the effectiveness of many antiarrhythmic drugs in ischemic conditions is
uncertain. METHODS AND RESULTS: We modeled two components of ischemia,
hyperkalemia (9.6 mM) and acidosis (pH 6.8), in voltage-clamped single rabbit
ventricular myocytes to help determine the effect of ischemia on the action of
these two drugs. In physiologic solution both E-4031 and dofetilide blocked I(Kr)
and significantly reduced total outward current. In hyperkalemic solution, both E
4031 and dofetilide showed significantly reduced blockade of I(Kr), while in
acidotic solution dofetilide showed significantly reduced blockade of I(Kr) and E
4031 showed a trend to reduced blockade. Neither drug significantly reduced total
outward current in hyperkalemic or acidotic solutions. CONCLUSIONS: In these
conditions, E-4031 and dofetilide demonstrate reduced blockade of I(Kr),
resulting in loss of class III effect. Furthermore, the complete loss of blocking
effect on total outward current during simulated ischemia suggests increases of
other repolarizing currents also contribute to loss of class III effect.
PMID- 10684460
TI - Molecular Delivery System for Antisense Oligonucleotides: Enhanced Effectiveness
of Antisense Oligonucleotides by HVJ-liposome Mediated Transfer.
AB - BACKGROUND: The effectiveness of antisense oligodeoxynucleotides for in vitro and
in vivo studies is limited by a low efficiency of cellular uptake and instability
due to degradation by nucleases. To overcome some of these problems, we recently
developed a transfer method that utilizes inactivated Sendai virus
(hemagglutinating virus of Japan [HVJ]) complexed with liposomes to deliver
antisense oligodeoxynucleotides. In this study, we compared the effectiveness of
the HVJ-liposome method versus a cationic liposome method versus passive uptake
to deliver antisense oligodeoxynucleotides against basic fibroblast growth factor
on angiotensin (Ang) II-induced rat vascular smooth muscle cell growth. METHODS
AND RESULTS: Twenty to twenty-eight hours after transfection, antisense
fibroblast growth factor oligodeoxynucleotides introduced by passive uptake and
HVJ-liposome method decreased basal DNA synthesis significantly as compared to
the sense, control, and scrambled oligodeoxynucleotides groups; however, 60-68
hours after transfection, only antisense fibroblast growth factor
oligodeoxynucleotides transduced by the HVJ-liposome method resulted in a
significant inhibition of DNA synthesis under basal and Ang II-(10(-;6)M)
stimulated conditions. The IC(25) of oligodeoxynucleotides assessed by the
inhibition of thymidine incorporation was significantly lower using the HVJ
liposome method than those using the other transfer methods. To clarify the
mechanisms of cellular uptake of oligodeoxynucleotides with the HVJ-liposome
method, we studied the cellular fate of fluorescein isothiocyanate (FITC)-labeled
oligodeoxynucleotides FITC-oligodeoxynucleotides was localized in nuclei at 5
minutes after transfection with the HVJ-liposome method. In contrast, FITC
oligodeoxynucleotides introduced by passive uptake was detected in nonnuclear
cellular compartments, possibly endosomes, but not the nuclei. Cellular
fluorescence of oligodeoxynucleotides introduced by passive uptake disappeared
within 24 hours, while that introduced by the HVJ-liposome method could be
observed up to 72 hours. CONCLUSION: These results demonstrate that the HVJ
liposome transfer enhanced the effectiveness of AS-fibroblast growth factor via
its specific molecular mechanisms of transfer.
PMID- 10684461
TI - Mechanical Ablation of Concealed Left Lateral Bypass Tract.
AB - A 50-yaer-old man with hypertension had been treated for supraventricular
tachycardia with several medications for nine years. In 1990, he was started on
amiodarone but a year later he developed side effects causing discontinuation of
amiodarone. Because of his recurrent episodes of palpitations associated with
near syncope, chest pain and shortness of breath, he underwent an
electrophysiology study in 1992 that showed orthodromic AVRT with the presence of
a concealed left-sided accessory bypass tract. Scheduled for radiofrequency
ablation the following day, after catheters were placed and during mapping of the
lateralmitral annulus, his tachycardia stopped abruptly without further
inducability. Isoproterenol infusion during atrial and ventricular stimulation
also failed to induce his original tachycardia. A year later, the patient
presented with palpitations that felt different than his previous experiences.
Work-up at that point only revealed a parasystolic focus on a 24-hour ECG
monitoring without any form of supraventricular tachycardia. This represents a
very unusual case by which the left lateral accessory pathway was mechanically
ablated with catheter manipulation. This led to the disappearance of the
orthodromic tachycardia that was easily induced before due to the activity of his
parasytolic focus. The latter continued for the following four years but the
patient has had no recurrences of his tachycardia.
PMID- 10684463
TI - The Multicenter Automatic Defibrillator Implantation Trial.
PMID- 10684462
TI - The Multicenter Automatic Defibrillator Implantation Trial.
PMID- 10684464
TI - Searching for the Ideal Class III Antiarrhythmic Agent: How Pure Should they Be?
PMID- 10684465
TI - Atorvastatin, a New HMG-CoA Reductase Inhibitor, Does Not Affect Glucocorticoid
Hormones in Patients With Hypercholesterolemia.
AB - BACKGROUND: Atorvastatin calcium (Lipitor) is a new 3-hydroxy-3-methylglutaryl
coenzyme A (HMG-CoA) reductase inhibitor. The present study was conducted to
examine the effect of pronounced cholesterol lowering on adrenal function in
patients with severe hypercholesterolemia. METHODS AND RESULTS: Adrenal function
was examined under basal conditions and following adrenal corticotropin hormone
stimulation in 40 patients (36 with heterogeneous familial and 4 with polygenic
hypercholesterolemia). The study was part of a larger study comparing the
efficacy and safety of atorvastatin, colestipol, atorvastatin + colestipol, and
simvastatin + colestipol treatment over a 1-year period. Maximum doses of all
agents were studied: 80 mg atorvastatin once daily, 40 mg simvastatin once daily,
and 20 g/day colestipol. At the end of the 1-year treatment period, reductions in
low-density lipoprotein cholesterol were 57%, 54%, and 49% for the atorvastatin,
colestipol + atorvastatin, and colestipol + simvastatin groups, respectively. No
clinically significant changes in basal serum cortisol levels were seen in any
treatment group during the 1-year treatment period. Mean serum cortisol
concentrations and area under the curve for cortisol concentration versus time
data following adrenal corticotropin hormone stimulation were not clinically
different during treatment compared with values obtained at baseline for any of
the treatment groups. CONCLUSIONS: Treatment with maximum doses of atorvastatin
for 1-year did not have any adverse effects on adrenal function under basal
conditions or during maximum stimulation. Similarly, colestipol therapy alone and
in combination with either atorvastatin or simvastatin did not appear to affect
adrenal function.
PMID- 10684466
TI - Intravenous Propafenone for Conversion of Atrial Fibrillation or Flutter to Sinus
Rhythm: A Randomized, Placebo-controlled, Crossover Study.
AB - BACKGROUND: Propafenone has been claimed to be effective in converting atrial
fibrillation and flutter to sinus rhythm; however, controlled clinical trials
have reported variable results, and data about the safety of propafenone in the
setting of heart failure are lacking. The aim of the present study was to
evaluate the efficacy and safety of intravenous propafenone in converting atrial
fibrillation and flutter to sinus rhythm. METHODS: Sixty patients with acute (<72
h) or chronic atrial fibrillation or flutter were included in a randomized,
placebo-controlled, conditional cross-over study. Twenty eight patients, of whom
12 were in New York Heart Association class III and IV, had heart failure.
Patients received intravenous propafenone (2 mg/kg in 10 minutes) and placebo
subsequently at 1 hour intervals if sinus rhythm was not achieved. The patients'
rhythms were continuously monitored for 1 hour and a 12-lead electrocardiogram, a
1-minute continuous rhythm strip and vital signs were recorded at baseline and at
15, 30, 45, and 60 minutes after the administration of each drug. RESULTS: Twenty
of teh 59 patients (34%) treated with propafenone converted to sinus rhythm,
while only 4 of the 50 patients (8%) treated with placebo converted (P <.001).
Propafenone was more effective in patients with acute (<72 h) atrial fibrillation
(64.5%). The conversion rate with propafenone was not significantly different
from placebo in patients with atrial flutter and chronic atrial fibrillation (>72
h). Propafenone significantly decreased (P <.005 vs placebo) mean ventricular
rate in nonresponders with a baseline heart rate of more than 100 beats/min. No
clinically significant adverse effect occurred. CONCLUSIONS: We conclude that
intravenous propafenone treatment is effective for converting acute atrial
fibrillation; however, it seems unlikely to be beneficial in atrial flutter and
chronic atrial fibrillation. Propafenone decreases ventricular rate in
nonresponders, and a single dose of propafenone is relatively safe even in
moderate-to-severe heart failure.
PMID- 10684467
TI - Sotalol Is More Powerful Than Propranolol in Suppressing Complex Ventricular
Arrhythmias.
AB - BACKGROUND: Sotalol has combined type II and type III antiarrhythmic properties.
Although the beta-blocking action of sotalol is thought to contribute to its
antiarrhythmic actions, few data are available from direct comparative clinical
trials with pure beta-blocking drugs. METHODS AND RESULTS: In this double-blind,
randomized, multicenter, placebo-controlled, parallel study, we have compared the
antiarrhythmic efficacy and safety of treatment with sotalol vs propranolol in
181 patients with organic heart disease and frequent (>30 ventricular premature
complexes [VPCs]/h) repetitive ventricular premature complexes. Eighty-seven were
randomized to receive sotalol and 94 received propranolol. The demographic and
clinical characteristics of the two groups were identical, and the majority of
patients had coronary artery disease or hypertensive heart disease. Most patients
had a long-standing history (>5 years) of ventricular arrhythmias and, in a
significant proportion, antiarrhythmic therapy with other drugs had failed in the
past. After withdrawal of all antiarrhythmic drugs and 1 week of placebo,
qualified patients were randomized to sotalol (320 mg/day) or propranolol (120
mg/day). patients not achieving adequate response were given higher doses of
sotalol (640 mg/day) or propranolol (240 mg/day)At baseline, both groups had
comparable frequency of total VPCs/hour (274/h and 255/h for sotalol and
propranolol groups, respectively) which was reduced to 71 VPCs/h and 109/VPCs/h,
respectively, at the end of phase 1. At final evaluation there was a
significantly greater response to sotalol as demonstrated by 80% reduction in
VPCs/hour with sotalol compared with only 50% reduction noted in the propranolol
group. Adequate therapeutic response was also achieved in a significantly greater
percentage of patients on sotalol compared with propranolol (56% vs 29%, P =.02).
Sotalol was also superior to propranolol in suppressing the VT events/day during
phase 1 (89% vs 78% reduction in VT events/day, P <.05). Sotalol was more
effective than propranolol in all subgroups and in patients with heart rate <75
beats per minute. CONCLUSIONS: Sotalol is more powerful than propranolol in
suppressing ventricular arrhythmias documented on Holter recordings. The
superiority of sotalol appears to be related to its combined class II and class
III antiarrhythmic actions.
PMID- 10684468
TI - Frequency-dependent Cardiac Electrophysiologic Effects of Tedisamil: Comparison
With Quinidine and Sotalol.
AB - BACKGROUND: Tedisamil is a potent bradycardiac/antiischemic drug known to
lengthen cadiac repolarization by blocking various potassium channels. Recent in
vivo experiments revealed that it is an antiarrhythmic agent. It was therefore of
interest to compare the cellular electrophysiologic effects of tedisamil with
those of quinidine and sotalol in isolated cardiac preparations. METHODS AND
RESULTS: The conventional microelectrode technique was applied in isolated dog
cardiac Purkinje and ventricular muscle fibers and in rabbit left atrial muscle.
Tedisamil (1 uM) and sotalol (30 uM) lengthened, while quinidine (10 uM)
shortened action potential duration in dog Purkinje fibers. The phase 1
repolarization was delayed by tedisamil and quinidine and not changed by sotalol.
In dog ventricular muscle and in rabbit atrial muscle, all three drugs studied
lengthened repolarization. In dog Purkinje fiber, tedisamil and sotalol
lengthened action potential duration more at slow than at high stimulation
frequency (reverse use-dependence). In dog ventricular muscle fibers, the effect
of the drugs was not clearly frequency dependent. In rabbit atrial muscle fibers,
the quinidine-evoked repolarization lengthening was most pronounced at
intermediate cycle lengths (500-1000 ms). Tedisamil and quinidine but not sotalol
depressed the maximal rate of depolarization (V(max)), which depended on the
stimulation frequency (use-dependence). The nature of the use-dependent V(max)
block differed between quinidine and tedisamil. Quinidine decreased V(max) at a
relatively wide range of stimulation frequencies whle tedisamil. Quinidine
decreased V(max) at a relatively wide range of stimulation frequencies while
tedisamil decreased V(max) largely at high rate of stimulation. Tedisamil and
quiinidine prevented or decreased the pinacidil-evoked action potential
shortening in dog ventricular muscle, suggesting block of the ATP-dependent
potassium channels (I(KATP)), while with sotalol such effect was not observed.
CONCLUSIONS: Although tedisamil, quinidine, and sotalol are known to lengthen the
QT interval, their cellular electrophysiologic effects substantially differ.
Tedisamil lengthens repolarization and prevents pinacidil-evoked action potential
duration shortening, suggesting I(K(ATP)) blockade. Its effect on the V(max) is
limited mostly to fast heart rate. These electrophysiologic effects of tedisamil
resemble those of chronic amiodarone treatment.
PMID- 10684469
TI - Nisoldipine Cardioplegia in the Isolated Rabbit Heart.
AB - BACKGROUND: The metabolic and hemodynamic effects of nisoldipine supplementation
in cardioplegia after ischemic injury were investigated in 13 isolated rabbit
hearts. Group 1 consisted of 6 hearts, which received St. Thomas II cardioplegic
solution. In group 2, nisoldipine was added to the cardioplegic solution at a
concentration of 0.1 mg/kg in 7 hearts. METHODS: The explanted hearts were
suspended from Langendorff apparatus and were perfused with Krebs-Henseleit
solution. Left ventricular pressure, heart rate, malondialdehyde, glutathione
peroxidase, glutathione reductase, reduced glutathione, oxidized glutathione,
creatine kinase MB, (CK-MB), aspartate transaminase, and lactate dehydrogenase
(LDH) were measured before and after 60 minutes of ischemia. Peak generated
pressure after ischemia was significantly higher in group 2 versus group 1 while
end-diastolic pressure was significantly lower in group 2 after ischemic arrest
(P <.05). RESULTS: Malondialdehyde levels were lower in group 2 (P <.05).
Glutathione peroxidase and glutathione reductase levels were significantly higher
in group 2 (P <.05). The only enzymatic significant difference was observed
between the preischemic and postischemic levels of aspartate transaminase in
group 2 (P <.05). CONCLUSIONS: These findings show beneficial effects of
nisoldipine cardioplegia, although its use as a cardioplegic additive is not yet
possible. We believe, however, the effects of oral nisoldipine before cardiac
surgery can be studied in a clinical setting.
PMID- 10684470
TI - Cardiac Arrhythmias Following Intravenous Nicotine: Experimental Study in Dogs.
AB - BACKGROUND: Nicotine, the active agent in tobacco, is released into the
circulation during cigarette smoking. It elevates plasma catecholamines, heart
rate, and arterial blood pressure; produces coronary spasm; and increases
myocardial work and oxygen demand with concomitant reduction in oxygen supply.
This may generate cardiac arrhythmias that might contribute to an increased
incidence of sudden death due to smoking. It is hypothesized that acute
administration of nicotine will induce cardiac arrhythmias, and this experimental
study was planned with an aim to assess arrhythmogenic activity as a result of
acute administration of nicotine. METHODS: Nicotine was administered in different
doses intravenously in 16 anesthesized dogs, and 52 experiments were carried out
at weekly intervals. In each experiment, continuing anesthesia and after nicotine
administration. They were scrutinized by two experienced electrocardiographers at
intervals of 1, 2, 3, 4, 5, 10, 15, and 30 minutes. RESULTS: Data revealed
nonsignificant arrhythmias with doses of 2.5, 5.0, and 10.0 mg/kg of intravenous
nicotine. The dose of 50 ug/kg induced supraventricular arrhythmias,
atrioventricular junctional arrhythmias, and ventricular arrhythmias.
Supraventricular bradycardia in 30 (83%; P <.0001), supraventricular arrhythmia
in 30 (83%; P <.0001), sinus arrest in 18 (50%; P <.003), atrial ectopics in 24
(67%; P <.0004), and atrial tachycardia in 98 experiments (25%; P <.021). These
results were statistically significant. In 18 experiments, sinus arrest was
observed to be missing P waves and QRS complexes for a period corresponding to
4:1-10:1 SA block, lasting 2-6 seconds, within 3 seconds of injection. Occurrence
of wandering pacemaker was observed in 6 experiments, atrial flutter in 2, and
atrial fibrillation in 2, but these incidents were not significant.
Atrioventricular junctional arrhythmias consisted of escape beats in 9 subjects
(25%; P <.02), premature contractions in 12 (33%; P <.005), first-degree heart
block in 9 (25%; P <.02), second degree heart block in 9 (25%; P <.02) and
atrioventricular dissociation in 9 (25%; P <.02). All arrhythmias in this
category were significant. Ventricular arrhythmias consisted of ventricular
premature contractions that were unifocal in 32 subjects (89%; P <.0001),
multifocal in 30 (83%; P <.0001), bigeminy in 28 salvos in 18 (50%; P <.003).
Sustained ventricular tachycardia (> 30 beats) in 12 experiments (33%; P <.005)
proved significant. The dose of 100 ug/kg induced fatal ventricular flutter and
ventricular fibrillation. The dog expired and experiments with that dose were not
repeated. CONCLUSION: Data reveal dose-dependent arrhythmogenecity of nicotine in
dogs. Smaller doses of nicotine did not produce significant arrhythmias. Higher
doses, bioequivalent to smoking two standard cigarettes, may generate cardiac
arrhythmias of simple to severe nature. Further work in human beings may confirm
whether nicotine in cigarette smoke will generate similar cardiac arrhythmias
especially in patients with autonomic imbalance and/or compromised and ischemic
myocardium.
PMID- 10684471
TI - Adrenergic-dependent Effect of Adenosine-induced Ventricular Fibrillation in the
Isolated Rabbit Heart.
AB - BACKGROUND: The present study examined the contributory role of endogenous
catecholamines in adenosine-induced ventricular fibrillation in isolation rabbit
hearts. METHODS AND RESULTS: Cardiac catecholamine depletion was induced in
eleven rabbits by the administration of 6-hydroxydopamine (2 x 30 mg/kg, every 12
hours intramuscularly). Hearts were removed 24 hours later, and subjected to 12
minutes of hypoxic perfusion followed by 40 minutes of reoxygenation while heart
rate was maintained with atrial pacing. One of six, and one of five hearts from 6
hydroxydopamine treated rabbits developed ventricular fibrillation during hypoxia
reoxygenation when exposed to 3,7-dimethyl-1-propargylzanthine (DMPX) (10 uM) +
adenosine (ADO) (1 uM) and DMPX (10 uM) + ADO (10 uM), respectively. In hearts
from a control group, not exposed to 6-hydroxydopamine, ventricular fibrillation
developed in each of five (100% incidence) hearts when perfused in the presence
of DMPX (10 uM) + ADO (10 uM) (P <.05). Nadolol (1 uM), a beta-adrenoceptor DMPX
(10 uM) + ADO (10 uM) treated hearts (n = 6, P <.05 vs DMPX + ADO treated
hearts). To ensure catecholamine depletion, spontaneously beating isolated hearts
from vehicle and 6-hydroxydopamine treated rabbits were perfused under normoxic
conditions while exposed to increasing concentrations of tyramine (1, 3, 10 mM)
and the change in heart rate was determined. A concentration-related, positive
chronotorpic response to tyramine was obtained in hearts from the vehicle treated
group that was absent in hearts from 6-hydroxy-dopamine treated rabbits or hearts
perfused in the presence of nadolol. CONCLUSIONS: The results demonstrate that
inhibition of the cardiac adenosine A(2) receptor, unmasks an adenosine A(1)
receptor profibrillatory effect that is dependent upon endogenous cardiac
catecholamines and beta-adrenoreceptor activation during myocardial hypoxia
reoxygenation.
PMID- 10684472
TI - Prevention of Hypercholesterolemic Atherosclerosis by Garlic, an Antixoidant.
AB - BACKGROUND: Investigations of the effects of high cholesterol diet in the
presence and absence of garlic on the genesis of atherosclerosis, the blood lipid
profile, aortic tissue lipid peroxidation product malondialdehyde,
chemiluminescence, a marker for antioxidant reserve and activity of antioxidant
enzymes (superoxide dismutase, catalase, and glutathione peroxidase were made in
rabbits. METHODS AND RESULTS: Four groups of 10 rabbits each were studied: group
1 was given regular rabbit chow, group 2 was given rabbit chow diet supplemented
with garlic powder (300 mg twice daily orally), group 3 was given 1% cholesterol
diet, group 4 was given 1% cholesterol diet supplemented with garlic powder (300
mg twice daily orally). Blood concentration of triglyceride, total cholesterol,
high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and
very low-density lipoprotein cholesterol were measured before and after 4 and 10
weeks of experimental diets. The aorta was removed at the end of protocol (10
weeks) for assessment of atherosclerotic changes (gross and microscopic),
malondialdehyde concentration, chemiluminescence, and activity of antioxidant
enzymes. Total cholesterol, low density-lipoprotein cholesterol and ratio of low
density lipoprotein cholesterol/high-density lipoprotein cholesterol and ratio of
low-density lipoprotein cholesterol/high-density lipoprotein cholesterol
increaserd in group 3 and 4; the increase was smaller in group 4 than in in group
3 although not significant. Serum high-density lipoprotein cholesterol decreased
to a similar extent in groups 3 and 4. Serum triglyceride and very low-density
lipoprotein cholesterol remained unchanged in group 3 but increased in group 4.
These values were significantly higher than those in group 1. Garlic in rabbits
with control diet decreased the levels of triglyceride and very low density
lipoprotein but did not affect the levels of total cholesterol, low-density
lipoprotein cholesterol, and high-density lipoprotein cholesterol and the ratio
of low-density lipoprotein cholesterol/high-density lipoprotein cholesterol.
There was an increase in aortic tissue malondialdehyde, chemiluminescence, and
activities of catalase and glutathione peroxidase in group 3 compared with those
in group 1. Levels of aortic malondialdehyde, chemiluminescence, catalase, and
glutathione peroxidase were lower in group 4 compared with group 3; however,
values for malondialdehyde and chemiluminescence were lower and that of catalase
and glutathione peroxidase were higher in group 4 compared with group 1.
Superoxide dismutase activity was similar in all the four groups.
Malondialdehyde, chemiluminescence, and activity of catalase of aortic tissue
decreased while activity of glutathione peroxidase increased in group 2.
Atherosclerotic changes were lower in group 4 compared with group 3. Histologic
changes were practically similar in groups 3 and 4. CONCLUSIONS: Increased levels
of malondialdehyde, chemiluminescence, and antioxidant enzymes associated with
development of atherosclerosis suggests a role for oxygen free radicals in the
pathogenesis of hypercholesterolemic atherosclerosis. The protection afforded by
garlic was associated with decrease in aortic malondialdehyde and
chemiluminescence inspite of no change in serum cholesterol. These findings
suggest that oxygen free radicals are involved in the genesis and maintenance of
hypercholesterolemic atherosclerosis and that use of garlic can be useful in
preventing the development of hypercholesterolemic atherosclerosis.
PMID- 10684473
TI - Mibefradil: A New Selective T-Channel Calcium Antagonist for Hypertension and
Angina Pectoris.
AB - Calcium antagonists are an established therapy for patients with hypertension and
angina pectoris, but their current usage is often limited by their pharmacologic
profilers and side effects. Mibefradil is a recently developed calcium antagonist
with a unique chemical structure, site of action, and set of pharmacologic
effects. Unlike currently available calcium channels as well as L-type channels.
It is further distinguished from the other calcium antagonists in that it is the
first member of a new class of calcium antagonists, the tetralol derivatives.
With chronic oral dosing, mibefradil attains steady-state plasma concentrations
within 3-4 days, has a bioavailability of approximately 90%, and a plasma half
life of 17-25 hours. It has a gradual onset of action and can be administered
once daily without regard to food intake. It increases coronary blood flow and
lowers peripheral vascular resistance. The vasodilatory effects of mibefradil are
associated with a lack of inotropic effect on myocardium, lack of neurohormonal
activation, and a reduction in heart rate. In clinical trials it has been
demonstrated to be an effective agent in the treatment of patients with
hypertension and angina pectoris, with a good safety and tolerability profile
regardless of age, gender, or race.
PMID- 10684474
TI - A Therapeutic Commentary.
AB - ABSTRACT: Thirty-one million patients in the United States undergo surgical
procedures every year. Approximately 10%-the majority of these with hypertension
are at an increased risk for perioperative and postoperative cardiovascular
morbidity and mortality. Thus, hypertensive patients requiring surgery,
especially the 2.1 million undergoing noncardiac procedures, should be evaluated
carefully for the magnitude, and if severe, the cause of the hypertension.
Additionally, their associated metabolic and cardiovascular status should be
characterized and corrected with aggressive therapy. Hypertensive patients with
known ischemic heart disease, those with multiple risk factors for ischemic heart
disease (IHD), some with valvular heart disease, and those with congestive heart
failure should be evaluated for their ability to perform the physical and social
activities of everyday life, and, when necessary, have formal stress testing.
Most studies suggest that blood pressures of 180/110 mm Hg or greater are
associated with a greater risk for perioperative ischemic events. Therefore, the
goals of blood pressure control should be to reduce the blood pressure without
jeopardizing organ function. Antihypertensive medication should be administered
until the time of surgery. beta-Receptor blockers should be instituted or
continued in patients with angina and in some patients with congestive heart
failure. Those without prior antihypertensive therapy might be best treated with
beta-blocker therapy perioperatively as evidenced by the Multicenter Study of
Perioperative Research Group with atenolol and those earlier studies with
metoprolol. The risks of the surgery should be discussed with the patient so the
risks can be weighed against the expected benefit. Studies suggest that
perioperative risk for any patient, and especially patients with hypertension,
are in part related to the adrenergic arousal before, during, and after the
procedure as evidenced by the rise in heart rate and blood pressure, along with
the liberation of clotting facators and increased risk for plaque rupture,
coronary vasoplasm, and consequent myocardial infarction and fibrosis.
PMID- 10684475
TI - Angiotensin II Receptor Regulates Ionic Currents in Guinea Pig Ventricular
Myocytes.
AB - BACKGROUND: Previous studies have shown that angiotensin II (Ang II) receptors
are preset in a wide variety of target tissues and that Ang II regulates the
target tissue functions through Ang II receptors. However, the action of Ang II
receptors on transsarcolemmal currents in ventricular myocytes has not been
elucidated. METHODS AND RESULTS: We performed whole-cell voltage clamp and patch
clamp experiments to determine the effects of Ang II-receptor agonists and
antagonists on ionic currents in single isolated guinea pig ventricular myocytes.
We found that extracellular perfusion of Ang II (30 nM) increased the L-type
Ca(2+) current from 581 +/- 27 to 837 +/- 42 pA (n = 5, P <.01). Ang II also
prolonged the Ca(2+) current activation and inactivation time constants. These
were reversible by losartan (100 nM), a type 1 Ang II receptor (AT(1)) blockade.
On the other hand, perfusion of 30 nM Ang II decreased K(+) current (I(K)) from
1543 +/- 28 to 1194 +/- 50 pA (n = 5, P <.05) and K(+) tail current (I(K-tail))
from 275 +/- 24 to 206 +/- 29 pA (n = 5, P <.05). These effects were also
abolished by perfusion of losartan. However, perfusion of Ang II resulted in an
increase of inward rectified K(+) current (I(K1)) in whole-cell recordings.
Single channel recordings showed that the increase in I(K1) was attributed to a
burst opening current with a larger unit of amplitude. These effects were
reversed by saralasin but not losartan, indicating possible type 2 Ang II
receptor (AT(2)) involvement. CONCLUSIONS: Our results provide evidence that Ang
II receptors regulate the transsarcolemmal currents in single guinea pig
ventricular myocytes. Therefore, Ang II regulation of ionic currents is mediated
through the different subtypes of Ang II receptors.
PMID- 10684476
TI - Electrocardiographic Changes and Mortality Due to Myocardial Infarction in Rats
With or Without Imidapril Treatment.
AB - BACKGROUND: Various angiotensin-converting enzyme inhibitors are known to improve
heart function and prolong survival in patients and animals after myocardial
infarction. Because myocardial infarction is known to induce arrhythmias, this
study tested the hypothesis that early treatment with the angiotensin converting
enzyme inhibitor imidapril reduces mortality during acute myocardial infarction
because of protective effects against arrhythmogenesis. METHODS AND RESULTS: Rats
were randomly divided into four groups: sham control, myocardial infarction, sham
plus imidapril, and myocardial infarction plus imidapril. Myocardial infarction
was produced by ligation of the left anterior descending coronary artery. Treated
rats received imidapril (1 mg/kg/day) through a gastric tube beginning 1 hour
after coronary occlusion; control rats received tap water. Electrocardiogram
(ECGs) were recorded 1, 3, 7, and 21 days postocclusion. Infarct size and scar
weight were determined at 21 days in the myocardial infarction groups with and
without imidapril treatment. ECGs of untreated rats showed ST-segment changes,
abnormal Q waves, premature ventricular complexes, and QT(c) prolongation 1-21
days after coronary occlusion. Total mortality in 21 days averaged 35% in
untreated rats; mortality within 48 hours was 30%. On the other hand, imidapril
treated rats showed fewer ST-segment changes, fewer abnormal Q waves, and a
decreased incidence of premature ventricular complexes after coronary occlusion;
the ST-segment and QT(c) interval returned to basal values within 1 week after
occlusion. Imidapril treatment did not affect the ECG pattern in sham-treated
control animals. Total mortality in the imidapril-treated group in 21 days after
infarction was 22.5%; mortality within 48 hours was 20% (P <.05 compared with the
untreated infarction group). Infarct size and scar weight caused by coronary
occlusion did not differ in the untreated and imidapril-treated groups.
CONCLUSIONS: Early treatment with imidapril markedly decreases mortality in rats
after acute myocardial infarction. The lower mortality is not associated with a
decrease in infarct size but is consistent with a protective effect of the drug
against arrhythmogenesis.
PMID- 10684477
TI - Platelet-Mediated Cardioprotective Effect Against Ischemia-Reperfusion Injury in
Isolated Rat Hearts: Role of Platelet Number and Contribution of Supernatant of
Aggregated Platelets.
AB - BACKGROUND: Previous studies have documented cardioprotective effects of
circulating platelets after reperfusion injury. The present study was designed to
examine the role of platelet number and contribution of platelet-released
mediators in the platelet supernatant in cardioprotection against ischemia
reperfusion-induced myocardial dysfunction. METHODS AND RESULTS: Isolated buffer
perfused (constant volume) Sprage-Dawley rat hearts were subjected to 25 minutes
of global ischemia followed by 30 minutes of reperfusion. Ischemia-reperfusion
resulted in myocardial dysfunction, indicated by an increase in coronary
perfusion pressure and left ventricular end-diastolic pressure, and a decrease in
developed left ventricular pressure. Perfusion of hearts with washed rat
platelets (10(3)-2.2 x 10(7) cells/mL) significantly (P <.01) attenuated these
indices of myocardial dysfunction upon ischemia-reperfusion in a concentration
dependent manner. A cardioprotective effect of platelets was observed at a
concentration as low as 10(5) platelets/mL. Similar cardioprotection was seen in
hearts perfused with the supernatant of aggregated platelets. CONCLUSIONS: These
observations indicate that the platelet-mediated cardioprotective effect against
ischemia-reperfusion in vitro is concentration dependent, and platelet-released
mediators in the platelet supernatant are protective against ischemia-reperfusion
injury.
PMID- 10684478
TI - Comparative Study of the Effects of Erythromycin and Roxithromycin on Action
Potential Duration and Potassium Currents in Canine Purkinje Fibers and Rabbit
Myocardium.
AB - BACKGROUND: Erythromycin and roxithromycin are macrolide antibiotics in common
clinical use. Erythromycin occasionally produces life-threatening arrhythmias
(torsades de pointes) by blocking the outward potassium current responsible for
repolarization of the cardiac action potential. METHODS AND RESULTS: We used
standard cellular electrophysiological and whole-cell patch-clamping techniques
to compare the relative efficacy of erythromycin and roxithromycin in prolonging
cardiac action potential in canine Purkinje fibers and in blocking individual
outward potassium currents in isolated rabbit ventricular myocytes. We
demonstrated significant prolongation of action potential duration in canine
Purkinje fibers by erythromycin but not roxithromycin at a concentration of 100
uM. The delayed rectifier, the outward potassium current thought to be most
sensitive to modulation by drugs, was significantly depressed by both agents at
concentrations of >/=30 uM in isolated rabbit ventricular myocytes. Both drugs
had similar potencies (26% and 21% reduction by 30 uM erythromycin and
roxithromycin, respectively, and 50% and 36% reduction by 100 uM erythromycin and
roxithromycin). Neither agent significantly blocked other potassium currents
(including the transient outward current). CONCLUSIONS: Taking into account
normally observed peak blood concentrations of these agents in clinical use and
the fact that roxithromycin is not normally administered intravenously, we
conclude that the risk of proarrhythmia during normal clinical use of oral
roxithromycin is extremely remote.
PMID- 10684479
TI - Lysophosphatidylcholine and Cellular Potassium Loss in Isolated Rabbit Ventricle.
AB - BACKGROUND: Lysophospholipids such as lysophosphatidylcholine (LPC) have many
direct electrophysiological effects on cardiac muscle and have been implicated as
a cause of lethal ventricular arrhythmias during acute myocardial ischemia.
Because extracellular K(+) accumulation is also a key arrhythmogenic factor
during acute ischemia, we examined the effects of LPC on cellular K(+) balance,
including its interaction with adenosine triphosphate-sensitive K(+) (K(ATP))
channels. METHODS AND RESULTS: Isolated rabbit interventricular septa paced at 75
beats/min were loaded with (42)K(+) to measure unidirectional K(+) efflux rate
(in (42)K(+) washout experiments) or tissue K(+) content ((42)K(+) uptake
experiments) and action potential duration (APD) during exposure to 20 uM LPC for
30 minutes. LPC caused tissue K(+) content to decrease by 15 +/- 2% (n = 4) at a
steady rate over 30 minutes, associated with gradual APD shortening and a delayed
increase in unidirectional K(+) efflux rate. Pretreatment with 12 uM cromakalim
to selectively activate K(ATP) channels shortened APD by 44 +/- 66% and had no
effect on net tissue K(+) content during control aerobic perfusion. However,
cromakalim increased net K(+) loss during exposure to LPC to 22 +/- 4%, a 47%
increase. CONCLUSIONS: LPC induced net K(+) loss in heart, which was potentiated
by the K(ATP) channel agonist cromakalim. This ATP finding suggests that if LPC
accumulates to similar levels during myocardial ischemia and hypoxia, it may be
an important mechanism in net K(+) loss.
PMID- 10684480
TI - Prolonged Captopril Therapy in Murine Viral Myocarditis.
AB - BACKGROUND: Acute myocarditis can progress to chronic heart muscle disease and
cardiomyopathy. In the coxsackievirus B(3) (CB(3)) mouse model of myocarditis,
early administration of captopril, an angiotensin-converting enzyme (ACE)
inhibitor, ameliorated histopathological changes in inflammation, necrosis, and
calcification and reduced heart weight. Late administration of captopril reduced
heart weight but did not affect the histological findings. In this study, we
investigated the effects of prolonged captopril treatment in the chronic phase of
this model. METHODS AND RESULTS: Three-week-old male CD(1) mice were infected
with CB(3) and then randomized to receive placebo or captopril starting on day 7
of infection. Captopril, 2 g/L, was given as the drinking water daily for up to 6
months. Autopsies were performed at 6 and 10 months. Heart-to-body weight ratios
were obtained, and deaths were tallied. Myocardial fibrosis was graded according
to a score system. In addition, picrosirius red stain (PSR) also was used for
assessment of collagen deposition. Mean heart weights were similar in both
groups. Mean body weight was significantly lower in captopril-treated mice (40.7
g) than in the untreated group (43.6 g) at 6 months (P =.0155), and mortality was
higher (8.7 vs 0.87%; P =.009). At 6 months, the mean myocardial fibrosis score
in treated mice (0.12) was significantly less than in untreated animals (0.35; P
=.035). With PSR, the mean myocardial fibrosis score in the captopril group
(1.20) was also significantly less than in the untreated group (1.58; P =.045).
At 10 months, fibrosis scores were similar in both groups. CONCLUSIONS: Chronic
captopril treatment in CB(3) myocarditis reduces myocardial fibrosis.
PMID- 10684481
TI - Formation of Reactive Oxygen Species in Various Vascular Cells During
Glyceryltrinitrate Metabolism.
AB - BACKGROUND: Anti-ischemic therapy with organic nitrates as nitric oxide (NO)
donors is complicated by the induction of tolerance. When nitrates are
metabolized to release NO, there is a considerable coproduction of reactive
oxygen species (superoxide radical and peroxynitrite) in vessels leading to
inactivation of NO, to diminished cyclic quanosine monophosphate production in
smooth muscle cells (SMC), to impaired vasomotor responses to the endothelium
derived relaxation factor (EDRF), and to formation of nitrotyrosine as a marker
of glyceryltrinitrate (GTN)-induced formation of peroxynitrite. The aim of the
study was to analyze in vitro the formation of superoxide radicals and of
peroxynitrite in GTN-treated endothelial and smooth muscle cells and in washed ex
vivo platelets using electron spin resonance and spin-trapping techniques.
METHODS AND RESULTS: Using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin
trap, it was shown that in platelets, smooth muscle, and endothelial cells
incubated acutely for 15 minutes with 0.5 mM GTN, the rate of generation of
reactive oxygen species (ROS) was twice as high as under control conditions.
Using the new spin-trap 2H-imidazole-1-oxide (TMIO), a GTN-induced peroxynitrite
formation was detected in SMC and in platelets incubated with 0.5 mM GTN for 15
minutes. Spin-trap 1-hydroxy-3-carboxy-pyrrolidine (CP-H) was used to estimate
the rate of ROS formation in platelets incubated for 15 minutes with 0.5 mM GTN;
the rate amounted to 14.6 +/- 1.1 nM/min/mg protein compared with 4.0 +/- 0.4
nM/min/mg protein in controls. The rate of ROS formation in SMCs was
substantially increased (240 +/- 16%) after initiation of GTN tolerance by
treatment of the cells in culture with 100 uM GTN for 24 hours. CONCLUSIONS: GTN
increases the formation of superoxide radicals in endothelial cells, SMCs, and
platelets. Peroxynitrite is formed during GTN metabolism in vascular cells and
may contribute to the development of tolerance. A decrease in the nitrate-induced
inhibition of platelet aggregation during GTN tolerance is associated with
oxidative actions of ROS formed in platelets during GTN metabolism.
PMID- 10684482
TI - Infarct Size Reduction by Ischemic Preconditioning Is a Monophasic, Short-Lived
Phenomenon in Anesthetized Pigs.
AB - BACKGROUND: Controversy exists concerning the duration of infarct size reduction
with ischemic preconditioning in different species. In the present study, we (a)
evaluated the time course of protection with preconditioning and (b) sought to
determine whether late protection (the "second window") after 24 hours is
manifest in the open-chest pig model. METHODS AND RESULTS: Six groups of
pentobarbital-anesthetized pigs underwent 1 hour of left anterior descending
coronary artery occlusion and 2 hours of reperfusion. Group 1 served as control,
and pigs in group 2 received two 10-minute episodes of preconditioning ischemia
followed by 30 minutes of reperfusion before the sustained 1-hour occlusion. In
groups 3-6, the period of intervening reperfusion between the preconditioning
stimulus and the index ischemia was extended to 60, 90, and 300 minutes and 24
hours, respectively. The area at risk was determined by fluorescein dye
injection, and infarct size was measured by incubation in p-nitrobluetetrazolium
and expressed as percent of the risk area. Infarct size in preconditioned pigs
(group 2) was significantly reduced compared with controls (25.6 +/- 3.9% v 71.3
+/- 5.9%, P <.001). Extension of the intervening reperfusion to 60, 90, and 300
minutes and 24 hours resulted in infarct sizes of 64.5 +/- 5.5%, 67.2 +/- 8%,
62.6 +/- 6.1%, and 75.3 +/- 7%, respectively (P = NS v control). CONCLUSIONS: The
infarct size-limiting effects of ischemic preconditioning last less than 1 hour
in the pig model. Moreover, in contrast to other species, a late protection at 24
hours after the preconditioning stimulus was not detected. These results indicate
that precondition-induced reduction of infarct size is monophasic in anesthetized
pigs.
PMID- 10684483
TI - The Effect of Atorvastatin on the Human Lens After 52 Weeks of Treatment.
AB - BACKGROUND: The effect of atorvastatin calcium (Lipitor, Parke-Davis, Morris
Plains, NJ) on the crystalline lenses of hypercholesterolemic patients was
evaluated and compared with that of lovastatin after 52 weeks of treatment to
reduce cholesterol levels. METHODS AND RESULTS: Six hundred ninety-six
atorvastatin-treated and 235 lovastatin-treated patients completed a large safety
study that included an ophthalmologic examination. Efficacy was evaluated as mean
percent change from baseline in low-density lipoprotein (LDL) cholesterol.
Patients received atorvastatin, 10 or 20 mg, or lovastatin, 20 or 40 mg, once
daily for either 36 or 52 weeks. Patients were evaluated by slit-lamp
examination, and a standardized format was used to describe the findings. Best
corrected visual acuity was measured using the Snellen chart. Patients treated
with atorvastatin had significantly (P =.05) greater decreases in LDL
cholesterol than those treated with lovastatin (37% vs 29%). Although some
patients in both groups experienced various lenticular opacities, none were
considered unexpected. In addition, there were no significant (P =.05)
differences in the distribution of cortical opacities and spokes right eye (OD)
and left eye (OS) and posterior subcapsular opacity (OS) between the atorvastatin
and lovastatin groups. In general, the percent deterioration in best corrected
visual acuity was similar in both groups. Overall, there were no clinically
significant differences in the development of lenticular opacity between patients
treated with atorvastatin and those treated with lovastatin. CONCLUSIONS:
Treatment with atorvastatin, 10 or 20 mg, significantly reduced LDL-cholesterol
(P <.05) and was not associated with an increased risk of lenticular opacity
development compared with lovastatin, a widely prescribed compound in the same
class of drugs.
PMID- 10684484
TI - Recent Advances in the Prevention of Coronary Artery Diseases: Focus on Primary
Prevention.
AB - BACKGROUND: Several new strategies for prevention of coronary artery disease have
emerged. This review examines the various approaches to primary prevention, and
some aspects of secondary prevention. METHODS AND RESULTS: The role of aspirin,
beta-blockers, exercise, diets, fish intake, vitamin E, and folic acid are
discussed. The potential role of chlamydia in atherosclerosis, the protective
effect of alcohol consumption, and the benefits of female sex hormones are also
examined. An update on lipid-lowering therapy, and a summary of the recent major
clinical trials establishing the use of 3-hydroxy-3-methylglutaryl-coenzyme A
reductase inhibitors in primary and secondary prevention of coronary artery
disease, are provided. CONCLUSIONS: An aggressive approach to medical management
of coronary artery disease a substantial reduction in risk.
PMID- 10684485
TI - Stroke Prevention in Patients With Atrial Fibrillation: What Have We Learned?
PMID- 10684486
TI - Therapeutic Concentrations of Heparin Augment Platelet Activation at the Time of
Coronary Angiography.
AB - Background: Besides its anticoagulant effects, heparin is known to alter platelet
(PLT) function. We examined the effects of unfractionated heparin on PLT function
in patients with stable coronary artery disease (CAD). Methods and Results: PLT
function was evaluated by whole-blood flow cytometry to detect PLT CD62
expression and by impedance aggregometry to assess the platelet aggregation (PA)
before and after bolus intravenous administration of low-dose heparin (2713 +/-
1231 U) in 16 patients undergoing coronary angiography (group 1) and high-dose
heparin (7937 +/- 2414 U) in 16 patients undergoing coronary angioplasty (group
2). Activated clotting time (ACT) and plasma antifactor-Xa heparin levels also
were measured. Heparin increased PLT CD62 expression, which was significantly
more pronounced in group 1 patients with plasma heparin levels less than 0.7 U/mL
and ACT of 222 +/- 52 seconds compared with group 2 patients with heparin levels
greater than 0.7 U/mL and ACT of 365 +/- 86 seconds (8 +/- 9 v -1 +/- 4% change
in resulting PLTs, P =.01, and 11 +/- 12 v 1 +/- 6% increase in adenosine
diphosphate (ADP) [5 uM]-stimulated PLTs, P =.02). Heparin produced a slight
increase in PA in group 1 patients (1.4 +/- 5.3 ohms) as compared with the group
2 patients, where it significantly suppressed PA (-3.0 +/- 5.3 ohms, P.05 v group
1). A strong and statistically significant negative correlation between change in
platelet CD62 expression and heparin concentration was observed in group 1
patients (r = -.5, P =.05, -ADP; r = -.65, P =.006, +ADP), whereas this
relationship was weak and did not reach statistical significance in group 2
patients (r = -0.4, P =.2, -ADP; r =.11, P = 0.9; +ADP). Conclusion: Bolus
administration of intravenous heparin augmented PLT activation in patients at
clinically relevant anticoagulant concentrations (<0.7 U/mL). These findings may
have implications for optimal dosing strategy for heparin as an antithrombotic
agent in clinical situations characterized by platelet-dependent thrombotic
events.
PMID- 10684487
TI - Double-Blind Comparison of Apolipoprotein and Lipoprotein Particle Lowering
Effects of Atorvastatin and Pravastatin Monotherapy in Patients With Primary
Hypercholesterolemia.
AB - METHODS AND RESULTS: A total of 305 subjects with primary hypercholesterolemia
were randomized in a 3:1 ratio to receive either atorvastatin 10 mg daily or
pravastatin 20 mg daily according to a 16-week double-blind comparative study of
the effect on apolipoprotein and lipoprotein particle levels. All patients had
low-density lipoprotein (LDL)-cholesterol levels between 4.2 and 6.6 mM and
triglyceride concentrations below 4.5 mM at baseline. After 16 weeks of
treatment, apoB (-27% and -16%; P <.001), apoE (-13.3% and -5.6%; P <.05) and the
triglyceride-rich LpC-III:B particle (-33% and -26%; P <.05) levels were reduced
to a significantly greater extent in the atorvastatin than in the pravastatin
treatment group. Both atorvastatin and pravastatin increased apoA-I levels, an
effect that was more pronounced in the pravastatin group (+7% and +11%; P <.002).
The increased apoA-I levels predominated on LpA-I in the atorvastatin group
(+11%) and on LpA-I:A-II in the pravastatin group (+13%). ApoA-II levels were
decreased with atorvastatin to a greater extent than with pravastatin (-1% and
+2.8%; P <.05). CONCLUSIONS: Although atorvastatin and pravastatin belong to the
same therapeutic family, they produce different effects in apoliprotein
concentrations in hypercholesterolemic patients. Atorvastatin, an agent of the
new generation, appears to efficiently reduce apoB-containing lipoprotein
particles containing apoC-III.
PMID- 10684488
TI - Effect of Nifedipine on the Steady-State Pharmacokinetics and Pharmacodynamics of
Irbesartan in Healthy Subjects.
AB - BACKGROUND: In clinical practice, nifedipine has the potential to alter the
pharmacokinetics, and therefore possibly the pharmacodynamics and efficacy or
safety, of irbesartan. The objectives of the current study were to determine the
effects of concomitant administration of nifedipine on the steady-state
pharmacokinetics and pharmacodynamics of irbesartan in 12 healthy subjects.
METHODS AND RESULTS: This was an open-label, randomized, crossover study. Each
subject received irbesartan 300 mg once daily for 4 days in one period and
irbesartan 300 mg once daily plus long-acting nifedipine (Procardia XL, Pratt
Pharmaceuticals, New York, NY) 30 mg once daily for 4 days in the other period.
The order of treatment periods was randomized, and a minimum 7-day washout phase
separated the two periods. Steady state was achieved by day 3. On day 4, no
significant differences were observed between the two treatments with respect to
maximum concentration of irbesartan at the end of the dosing interval (C(max)) or
the area under the plasma concentration versus time curve during a dosing
interval (AUC(tau)) of irbesartan. Steady-state C(max) and AUC(tau) met the
criteria for bioequivalence when irbesartan was administered alone or with
nifedipine. On day 4, mean plasma renin activity was somewhat higher at every
point but one when irbesartan was administered with nifedipine; however, no
significant difference was observed between the two treatments in mean 24-hour
AUC values. On day 4, there was a modest overall decrease from baseline in mean
blood pressure for both treatments. No significant differences were observed
between the two treatments in mean 24-hour AUC values for seated diastolic or
systolic blood pressure. No serious adverse events were reported. CONCLUSIONS:
Concomitant administration of nifedipine 30 mg with irbesartan 300 mg for 4 days
in healthy subjects (1) does not alter the steady-state pharmacokinetic
parameters of irbesartan, (2) results in C(max) and AUC(tau) values for
irbesartan that meet the criteria for bioequivalence, and (3) is well tolerated.
PMID- 10684489
TI - A Multicenter, Placebo-Controlled, Dose-Ranging Study of Atorvastatin.
AB - BACKGROUND: Coronary heart disease (CHD) is the number one cause of death in
Western societies. Elevated levels of plasma low-density lipoprotein (LDL)
cholesterol and triglycerides (TG) increase the risk for CHD. 3-Hydroxy-3
methylglutaryl conenzyme A (HMG-CoA) reductase inhibitors effectively reduce
plasma cholesterol levels in patients with hypercholesterolemia. This study
assesses the safety and dose-related effects of atorvastatin calcium on
lipoprotein fractions in patients with LDL cholesterol levels between 160 mg/dL
(4.1 mM) and 250 mg/dL (6.5 mM) or less and TG levels of 400 mg/dL (4.5 mM) or
less. METHODS AND RESULTS: Sixty-five patients were enrolled in a 6-week,
randomized, placebo-controlled, parallel-group study. Patients received placebo
or atorvastatin 10, 20, 40, 60, or 80 mg once daily. Adjusted mean decreases in
LDL cholesterol for patients receiving atorvastatin 10, 20, 40, 60, and 80 mg
were 37%, 42%, 50%, 52%, and 59%, respectively, compared with a mean increase of
0.3% for patients receiving placebo; the differences between each of the
atorvastatin dose groups and placebo were statistically significant (P =.0001).
Total cholesterol, triglycerides, and apolipoprotein B were significantly reduced
in atorvastatin groups (P =.0001). Adverse events were similar in the placebo and
atorvastatin treatment groups. No patient had a serious adverse event or withdrew
because of an adverse event during this study. CONCLUSIONS: Atorvastatin
effectively lowered plasma LDL cholesterol, triglycerides, and apoB levels in a
dose-related manner. Atorvastatin was well tolerated in hyperlipidemic patients
over a 6-week period.
PMID- 10684490
TI - Mechanisms of Impaired Endothelial Function Associated With Insulin Resistance.
AB - BACKGROUND: The insulin-resistant (IR) syndrome is causally related to
hypertension and cardiovascular events; however, the underlying mechanism remains
elusive. The current study was designed to determine (1) whether the IR syndrome
causes vascular dysfunction and (2) whether insulin resistance alters the
activity of the individual endothelium-derived relaxing factors. METHODS AND
RESULTS: Insulin resistance was induced in Sprague-Dawley rats by a 4-week
fructose-rich diet. Subsequently, mesenteric arteries ( approximately 250 uM)
were removed from control and IR rats, and intraluminal diameter was used to
assess vascular response to pharmacological probes. Studies with sodium
nitroprusside showed that vascular relaxation did not differ between IR and
control groups. In contrast, maximal vascular relaxation to acetylcholine (10(-9)
to 10(-4) mol/L) in phenylephrine preconstricted arteries was decreased in the IR
group (44 +/- 4%) versus control (89 +/- 5%) (P <.01). N-nitro-L-arginine (LNNA)
pretreatment further impaired acetylcholine-induced maximal relaxation in the IR
group from 44 +/- 4% to 12 +/- 3%; P <.01. In control rats, maximal relaxation
was only slightly impaired by the addition of LNNA (89 +/- 5% to 68 +/- 6%; P
<.05). The addition of indomethacin to acetylcholine did not affect maximal
relaxation in either group. When potassium chloride (KCl) was used fro
preconstriction, relaxation to acetylcholine in the IR group was similar to that
found with phenylephrine preconstriction (41 +/- 4% v 44 +/- 4%, respectively);
however, KCl preconstriction significantly decreased acetyolcholine-induced
relaxation in control rats (89 +/- 5% to 43 +/- 5%; P >.01). CONCLUSION: Insulin
resistance impairs endothelium-dependent relaxation in small mesenteric arteries.
It appears that insulin resistance transforms the primary relaxant factor from
endothelial-derived hyperpolarizing factor to nitric oxide. These findings
suggest that hypertension and atherosclerosis associated with the IR syndrome are
caused, at least in part, by endothelial dysfunction.
PMID- 10684491
TI - Nitric Oxide Alters Human Microvascular Endothelial Cell Response to Cyclic
Strain.
AB - BACKGROUND: Nitric oxide (NO), a potent vasodilator and inhibitor of platelet
function, is elaborated constitutively by endothelial cells through the oxidation
of l-arginine by endothelial NO synthase. Although several biochemical agonists,
such as bradykinin, have been shown to stimulate NO production by the
endothelium, the effects of physical factors have been less well characterized.
We have previously examined the shear-stress-dependent induction of NO production
by the endothelium, and others have examined the effects of transmural pressure
on NO production. In the current study, we analyzed the effects of cyclic strain
or load in the presence and absence of an NO agonist on endothelial cell
proliferation. METHODS AND RESULTS: Subconfluent human microvascular endothelial
cells were grown on deformable culture plates in media containing 10% fetal
bovine serum and 1 mM l-arginine, and then subjects to either 0, 11, 18, or 27%
cyclic strain at a frequency of 1 Hz. Nitrogen oxides (S-nitrosothiols and free
NO) in media were measured by photolysis-chemiluminescence at the end of 24
hours, as were cell number, [(3)H]thymidine incorporation, and total cell
protein. In the absence of an NO agonist, 11% cyclic strain produced a 73 +/- 17%
increase in nitrogen oxides compared with control (P <.05), whereas 18 and 27
cyclic strain produced no significant increase in nitrogen oxides compared with
control. However, cells subjected to 27% strain increased cell number (by 98 +/-
17%) and [(3)H]thymidine incorporation (by 16 +/- 4%, P <.05) compared with
control. In an attempt to examine further the effects of endogenous NO on the
cells' proliferation response to increasing levels of cyclic strain, we incubated
human microvascular endothelial cells with 1 uM bradykinin and subjected them to
27% cyclic strain. In the presence of bradykinin and 27% cyclic strain,
production of nitrogen oxides and endothelial NO synthase activity were increased
by 110 +/- 37% and 135 +/- 7%, respectively (P <.05 compared with control);
however, we observed no significant increase in cell number (5 +/- 5%), despite
an 86 +/- 7% increase in [(3)H]thymidine incorporation (P <.05). CONCLUSION:
These results suggest that endogenous NO production by human microvascular
endothelial cells regulates their growth response to cyclic strain. Modulation of
NO production in vivo in areas of the vasculature that are subjected to increased
levels of strain may represent one potential mechanism by which to alter
endothelial cell proliferation.
PMID- 10684492
TI - Protective Effects of Iganidipine on Morphological and Functional Changes of
Arteries in Hypertensive Dahl Rats.
AB - BACKGROUND: This study was performed to examine the protective effects of
iganidipine, a new water-soluble calcium antagonist, on the morphological and
functional changes of arteries in Dahl salt-sensitive (Dahl-S) rats. METHODS AND
RESULTS: Vehicle and iganidipine were administered orally to Dahl-S rats fed a
high-salt diet (HSD) for 8 weeks. Aorta, superior mesenteric arteries (SMA), and
peripheral mesenteric arteries (PMA) were examined light-microscopically or
electon-microscopically. Relaxant responses of isolated aorta and SMA were
recorded isometrically. In rats fed HSD, blood pressure was markedly increased.
Light microscopy showed intimal and medial hypertrophy, periarteritis, and
narrowed arterial lumen in the PMA. Transmission and scanning electron microscopy
or light microscopy showed medical thickness in the aorta and SMA and hypertrophy
of endothelial cells and dilatation of the subendothelial space only in the
aorta. In the SMA, both endothelium-dependent relaxation (EDR) and endothelium
independent relaxations (EIR) were reduced to a similar extent. In the aorta, the
EDR was more markedly attenuated than the EIR. Iganidipine at 3 mg/kg/day showed
a 24-h sustained hypotensive effect and completely prevented the morphological
and functional changes in both arteries. Iganidipine at 1 mg/kg/day, which
lowered blood pressure only for several hours, decreased the injuries in PMA and
aortic endothelium and moderately restored the EDR in the aorta. Iganidipine at
0.3 mg/kg/day had no effects. CONCLUSIONS: In Dahl-S rats fed an HSD, iganidipine
completely prevented all the changes at a sustained-hypotensive dose and
prevented the injuries of PMA and aortic endothelium and the reduction of EDR in
the aorta at a nonsustained hypotensive dose. Nonhemodynamic effects of
iganidipine may be partly involved in its protective effects against arterial
injuries.
PMID- 10684493
TI - The Effect of Melatonin on Hemodynamics, Blood Flow, and Myocardial Infarct Size
in a Rabbit Model of Ischemia-Reperfusion.
AB - BACKGROUND: Melatonin, a hormone, has gained popularity and is being used by
millions for a variety of indications. There are few data on its safety or its
effects on hemodynamics and coronary blood flow. Also, studies have confirmed
that melatonin is a potent antioxidant. Therefore, it may be capable of
scavenging free radicals during the reperfusion phase after a heart attack. This
study evaluates the safety of melatonin with regard to its cardiovascular effects
and tests the hypothesis that melatonin might be protective in the setting of
ischemia-reperfusion and reduce myocardial infarct size. METHODS AND RESULTS:
Anesthetized rabbits were treated with melatonin (n = 8, 10 mg/kg, intravenously)
10 minutes before coronary artery occlusion (CAO) and again 15 minutes before
reperfusion. Control rabbits received vehicle (n = 8). All rabbits underwent 30
minutes of occlusion and 3 hour reperfusion. Both before and during CAO,
melatonin did not alter heart rate compared with control (185 +/- 7 beats/min v
181 +/- 7 before; and 179 +/- 5 v 181 +/- 9 during, respectively, P = NS) or
blood pressure (70 +/- 4 mmHg v 66 +/- 6 before and 59 +/- 4 v 58 +/- 5 during,
respectively, P = NS). Regional myocardial blood flow (RMBF) was similar before
CAO in the melatonin group (1.18 +/- 0.17 mL/min/g) versus the control group
(1.15 +/- 0.10 mL/min/g). Infarct size, expressed as a fraction of ischemic risk
zone, was similar in the melatonin (0.29 +/- 0.03) and control groups (0.29 +/-
0.06, P = NS). At a higher dose of 50 mg/kg in treated (n = 7) versus control (n
= 7) rabbits, melatonin treatment did not alter heart rate (204 +/- 14 in
melatonin group v 181 +/- 5 in controls, P = NS) or blood pressure (80 +/- 11 in
melatonin v 66 +/- 7 in controls, P = NS) when compared with control. Melatonin
at this dose also did not affect infarct size, 0.38 +/- 0.06, when compared with
control, 0.34 +/- 0.07, P = NS. CONCLUSION: Melatonin's effects on hemodynamics
and coronary blood flow were neutral, and it did not exacerbate myocardial
ischemia or necrosis in this model. Melatonin appears to be a safe drug with no
apparent effects on the cardiovascular system in this model.
PMID- 10684494
TI - ACE Inhibitors and Renal Vascular Responses in the Spontaneously Hypertensive
Rat.
AB - BACKGROUND: Substantial evidence has accumulated for the intrarenal generation of
functionally important quantities of angiotensin II (Ang II). To assess the
possibility that Ang II generation occurs beyond a barrier to diffusion from the
vascular compartment, six angiotensin-converting enzyme (ACE) inhibitors varying
widely in their lipid solubility were employed in the spontaneously hypertensive
rat (SHR) and their normotensive controls (WKY). The biological end points were
renal blood flow and its response to Ang II. RESULTS: Two ACE inhibitors,
ramipril and captopril, induced a larger increase in renal blood flow and
enhanced the renal vascular response to Ang II substantially more than did
enalapril and lisinopril. The two prodrugs, enalapril and ramipril, which are
substantially more lipophilic than the respective active drugs, enalaprilat and
ramiprilat, showed equivalent responses. The partial agonist saralasin virtually
abolished the renal vasodilator response to ramipril. The pattern of response was
similar in WKY, but the responses were substantially smaller. CONCLUSIONS: The
results support the concept that a functionally important compartment for
intrarenal Ang II formation exists in the healthy rat and that this process is
amplified in the SHR.
PMID- 10684495
TI - Clonidine-Induced Heat-Shock Protein Expression in Rat Aorta.
AB - BACKGROUND: Restraint-stress and administration of drugs that precipitate
hypertension induce heat-shock protein (HSP) expression in the aorta. The exact
mechanism supporting this hypertension-related HSP response is unclear because
HSP induction is blocked by receptor-selective and nonselective antihypertensive
agents. METHODS AND RESULTS: To identify mechanisms contributing to the
pharmacological/physiological regulation of the HSP response in cardiovascular
tissues, we administered clonidine to awake and freely moving animals to
determine its effect on HSP expression in vivo. Inconsistent with previous work,
we found that clonidine produced a dose-dependent and transient increase in HSP70
mRNA levels in the aorta. No other tissue examined displayed an HSP response
after clonidine administration. Clonidine-induced HSP expression was not
restricted to the HSP70 family; HSP89alpha, HSP89beta, and HSP60 were also
induced. Interestingly, no heat-shock element-binding activity was observed after
clonidine administration, suggesting that unusual transcriptional regulatory
mechanisms mediate this response. Yohimbine and nifedipine blocked HSP70 mRNA
expression, whereas isoproterenol, mecamylamine, and reserpine had no effect.
CONCLUSIONS: The functional consequence of HSP expression in cardiovascular
tissues may be to alter the responsiveness of cells in these tissues to
subsequent drug or stress exposures, thereby implicating the HSP response as an
important component of cardiovascular homeostasis. If so, treatment of mammalian
organisms with drugs capable of inducting selective HSP expression in vascular
tissue may alter the progression of cardiovascular disease processes.
PMID- 10684496
TI - Update on Atrial Fibrillation: Restoration of Sinus Rhythm or Ventricular Rate
Control?
AB - In patients with persistent atrial fibrillation, two therapeutic alternatives
exist, namely restoration and maintenance of sinus rhythm versus ventricular rate
control combined with anticoagulation. Currently, the selection of the best
therapeutic strategy in an individual patient relies for the most part on
clinical judgement and personal experience. At present, there are no prospective
scientific data to support the superiority of one treatment over the other with
respect to overall survival or quality of life. This review summarizes the
present knowledge on this important clinical problem with particular emphasis on
issues such as efficacy of antiarrhythmic drugs to prevent recurrent atrial
fibrillation, proarrhythmic hazards of these compounds, or efficacy and safety of
anticoagulation in nonrheumatic atrial fibrillation. These data serve as the
basis of ongoing clinical trials prospectively comparing the merits and demerits
of the two therapeutic strategies in the most common arrhythmia encountered in
clinical practice.
PMID- 10684497
TI - Atrial Fibrillation: Defining Some Unanswered Questions.
PMID- 10684498
TI - Different Effects of Amiodarone and Quinidine on the Homogeneity of Myocardial
Refractoriness in Patients With Intraventricular Conduction Delay.
AB - BACKGROUND: Increases in QT and JT dispersion have been suggested as indicative
of a proarrhythmic potential as a result of heterogeneity in myocardial
refractoriness, the reduction of which by antiarrhythmic agents might be
associated with a beneficial effect on the development of serious ventricular
arrhythmias. METHODS: To test the hypothesis that amiodarone reduces the heter
ogeneity of ventricular refractoriness to a significantly greater extent than
quinidine in patients with intraventricular conduction defects under treatment
for ventricular arrhythmias, the corrected and uncorrected QT and JT intervals
and dispersions from 12-lead surface electrocardiograms were determined in 120
patients with intraventricular conduction defects with cardiac arrhythmias before
and during treatment with amiodarone (n = 60) and quinidine (n = 60). RESULTS:
Amiodarone increased QT from 403 +/- 50 ms to 459 +/- 47 ms (P <.001), with a
similar increase in the corrected QT interval (QTc) (P <.001). Amiodarone reduced
QT dispersion by 40% (P <.001), whereas quinidine increased by 18% (P <.001). The
net effects of both drugs were similar for OTc. Amiodarone, but not quinidine,
reduced heart rate significantly; amiodarone had no effect on the QRS; but
quinidine increased if (P <.001). Quinidine as well as amiodarone increased the
JT and JTc intervals significantly, but the effect of quinidine was qualitatively
less striking. Amiodarone decreased the JT dispersion by 33% (P <.001) and JTc
dispersion by 37% (P <.001). On the other hand, quinidine increased the
corresponding values for JT and JTc by 18% (P <.001) and 21% (P <.001),
respectively. The overall data on QT and JT dispersion indicate an improvement in
the homogeneity of myocardial refractoriness with amiodarone treatment and the
converse with quinidine treatment; this observation is consistent with a lower
proarrhythmic propensity and mortality with amiodarone than with quinidine.
Quinidine increased the QRS interval more than amiodarone, and the data indicate
that in patients with intraventricular conduction defects, the monitoring of the
JT interval might more accurately reflect changes in myocardial repolarization.
CONCLUSIONS: Amiodarone and quinidine both increased the corrected and
uncorrected QT and JT intervals; amiodarone decreased and quinidine increased the
dispersion of these intervals, and these results suggested an improvement in the
homogeneity of myocardial refractoriness as a result of amiodarone treatment and
the converse as a result of quinidine treatment. Quinidine increased the QTS
interval more than amiodarone, and the data indicate that in patients with
intraventricular conduction defects, the monitoring of the JT interval might more
accurately reflect changes in myocardial repolarization.
PMID- 10684499
TI - Significance of Supraventricular Tachyarrhythmias After Coronary Artery Bypass
Graft Surgery and Their Prevention by Low-Dose Sotalol: A Prospective Double
Blind Randomized Placebo-Controlled Study.
AB - BACKGROUND: The single most frequent complication after coronary artery bypass
graft surgery is the occurrence of supraventricular tachyarrhythmias leading to a
prolonged hospital stay. Although several drugs have been used to treat these
arrhythmias, effective prevention was only possible with beta-blocking drugs in
selected patients. It was, therefore, the aim of the present study to evaluate
the significance of supraventricular tachyarrhythmias in presence of today's
cardioprotective management in a broad spectrum of patients and to assess the
possible preventive effect and safety of low-dose sotalol after coronary artery
bypass graft surgery. METHODS AND RESULTS: In a prospective randomized double
blind placebo-controlled trial, 220 consecutive patients referred for elective
coronary artery bypass graft surgery were randomized to 80 mg sotalol twice daily
(n = 110) or matching placebo (n = 110) for 3 months with the first dose given 2
hours before surgery. There were no significant differences in baseline
characteristics between the two groups. Low-dose sotalol reduced the rate of
supraventricular arrhythmias from 43% (placebo) to 25% (sotalol, P <.01), which
was atrial fibrillation in 83%, flutter in 7%, and other supraventricular
arrhythmias in 10%. Only 7% of all arrhythmias were observed after day 9.
Hospital stay was 11 +/- 4 days in patients with supraventricular arrhythmias
versus 9 +/- 2 days (P <.001) in patients without. On the fourth postoperative
day, heart rate was lower in the sotalol group (75 +/- 12 versus 86 +/- 14 beats
per min; P <.0001), but QTc was not significantly prolonged (sotalol, 0.44 +/-
0.03; placebo, 0.43 +/- 0.03; P, ns). Study medication had to be discontinued due
to side effects in 6.4% of sotalol and 3.6% of placebo patients (P, ns), but
relevant side effects occurred only in two sotalol patients late after surgery.
CONCLUSIONS: These data show that without antiarrhythmic therapy the incidence of
supraventricular arrhythmias after coronary artery bypass graft surgery is high
(43%) and that supraventricular arrhythmias were associated with a prolonged
hospital stay (+/-2 days). Prophylactic treatment with low-dose sotalol reduced
the incidence of supraventricular arrhythmias significantly (by 40%), thereby
reducing overall hospital stay in treated patients. Because more than 90% of all
supraventricular arrhythmic episodes occurred within 10 days after surgery and
considering the small proarrhythmic effect of sotalol late after surgery,
prophylactic treatment with sotalol may be recommended for the first 10
postoperative days to safely reduce supraventricular tachyarrhythmias.
PMID- 10684500
TI - Use of Lipid Drugs With Acute Myocardial Infarction Patients: An Examination of
Physician Prescribing Behaviors.
AB - BACKGROUND: Clinical trials have shown that the use of lipid-lowering agents in
postmyocardial infarction (MI) patients reduces rates of subsequent coronary
events, reduces coronary artery bypass surgery rates, and improves survival.
Physician decisions to prescribe lipid-lowering drugs is influenced by a number
of patient factors, including age, medical history, and serum cholesterol levels.
The purpose of this study was to examine physician behaviors in prescribing lipid
lowering therapy in patients after acute MI. METHODS AND RESULTS: A retrospective
study was conducted at a local community-based hospital. A total of 129 patients
with validated acute MI, hospitalized between January 1996 and December 1996, was
included in the study sample. Variables abstracted included patient age, sex,
race, primary diagnosis, medical history, lipid-lowering interventions of the
discharge plan, and other discharge instructions regarding smoking cessation,
activity, and dietary modification. Descriptive analysis was performed. The study
showed that only 7 subjects (8.8%) were discharged on lipid-lowering drugs.
Several patients who did not undergo therapy had either a low-density lipoprotein
concentration of <130 (n = 13), a high-density lipoprotein concentration of >50
(n = 6), or were on hormone replacement therapy (n = 3). Dietary modification was
advised in 100% of subjects (n = 54) for whom the data were included in the
charts. CONCLUSIONS: The results of this descriptive study suggests that lipid
lowering drugs are being utilized at low rates in the secondary prevention of
acute MI. However, additional risk-lowering factors may play a role in the
decision to discharge without drugs. Because of potential side effects associated
with their use, a prudent path appears to be the norm in prescription of lipid
lowering drug therapy for MI patients.
PMID- 10684501
TI - Adrenomedullin Does Not Inhibit Human Platelet Aggregation.
AB - BACKGROUND: Adrenomedullin (ADM) is a hypotensive peptide isolated from human
pheochromocytoma extracts discovered in 1993 using an assay system designed to
monitor its ability to increase rat platelet adenosine 3',5'-cyclic monophosphate
(cAMP) levels. Physiological mediators that elevate cAMP levels, such as
prostaglandin (PG)E(1) and PGI(2), have also been shown to inhibit platelet
aggregation. Therefore, we have chosen to investigate the effect of ADM, a
peptide shown to increase platelet cAMP levels, on human platelet aggregation.
METHODS AND RESULTS: Platelet-rich plasma prepared from blood donors was
incubated with ADM (10(-9)-10(-6) M) for 1 min at 37 degrees C before the
addition of a submaximal dose of adenosine 5'-diphosphate (ADP). ADM did not
alter the platelet aggregatory response to ADP. PGE(1), a substance known to
inhibit ADP-induced platelet aggregation (10(-6) M), however, inhibited ADP
induced platelet aggregation. In addition, the ADM induced a dose-dependent
relation in rings of human chorionic arteries. CONCLUSIONS: These data may be
interpreted to suggest that human platelets do not possess a functional ADM
receptor couple with adenylate cyclase.
PMID- 10684502
TI - A Multicenter Study Evaluating the Effects of Sevoflurane on Renal Function in
Patients With Renal Insufficiency.
AB - BACKGROUND: This multicenter study was undertaken to compare the effect of
sevoflurane with that of isoflurane on renal function in 26 patients with pre
existing renal insufficiency. Sevoflurane undergoes hepatic metabolism, with
release of inorganic fluoride. Elevated fluoride levels have been associated with
renal impairment in patients undergoing methoxyflurane anesthesia raising
concerns about the nephrotoxic potential of sevoflurane. METHODS: Patients were
ASA II or III class, with renal insufficiency defined by a preoperative serum
creatinine concentration of 1.5-3.0 mg/dl. A standardized anesthetic regimen was
used consisting of intravenous induction with propofol, vecuronium for muscle
relaxation, and fentanyl for analgesia. Patients were randomized to receive
either isoflurane or sevoflurane with 100% oxygen. Blood samples were obtained
preoperatively and at 24, 48, and 72 h postoperatively for renal/electrolyte
determinations. Blood samples for plasma fluoride measurement were obtained
preoperatively. RESULTS: Plasma fluoride levels were significantly higher in
patients receiving sevoflurane at all measurement points from 0 to 72 h
postanesthesia. Mean peak fluoride concentration was 33.4 uM. The maximum
fluoride value measured was 51.2 uM. There were no significant differences in
postoperative serum creatinine values at any time between patients receiving
sevoflurane or isoflurane. CONCLUSIONS: Sevoflurane metabolism produces
elevations in plasma fluoride concentrations relative to isoflurane. Despite the
increase in plasma fluoride levels, the administration of sevoflurane to patients
with renal insufficiency did not produce any adverse effects on renal function as
measured by serum creatinine concentration when compared with isoflurane.
PMID- 10684503
TI - Pharmacokinetics of Catecholamines During Hemofiltration in Pediatric Patients.
AB - BACKGROUND: Continuous hemofiltration is used in pediatric patients with acute
renal failure. Many of these patients are treated with catecholamines for
hemodynamic instability. The authors studied the pharmacokinetics of dopamine and
dobutamine on patients undergoing continuous venovenous hemofiltration. METHODS
AND RESULTS: Three critically ill pediatric patients with acute renal failure and
cardiovascular instability treated with hemofiltration and intravenous infusion
of dopamine and/or dobutamine were entered into the study. Blood samples were
drawn at steady-state levels from the arterial port (inflow) of the hemofilter,
from the venous port (outflow) of the hemofilter, and from the ultrafilter.
Sixteen (n = 16) pharmacokinetic measurements were made, six (n = 6) for dopamine
and 10 (n = 10) for dobutamine. The clearance of dopamine by the hemofilter was
0.078 +/- 0.011 mL/kg/min, and for dobutamine it was 0.036 +/- 0.008 mL/kg/min.
On the average, 0.56% of the dopamine dose and 0.13% of the dobutamine dose was
removed by the hemofilter. CONCLUSIONS: The pharmacokinetics of dopamine and
dobutamine at the dosage range of 5-25 ug/kg/min are not altered by continuous
hemofiltration. Relative to total plasma clearance, negligible amounts of the
drug were removed. The dosage of these catecholamines need not be adjusted during
continuous hemofiltration.
PMID- 10684504
TI - Effect of beta-Adrenoceptor Antagonists on Phospholipid N-Methylation Activities
of Cardiac Sarcolemma.
AB - BACKGROUND: Some beta-adrenoceptor antagonists exert a negative inotropic action
by affecting Ca(2+) fluxes in the myocardial cell as a consequence of their
interaction with sarcolemmal and sarcoplasmic reticular membranes. This action
may be caused by their effects on the chemicophysical properties of membranes
phospholipids. Because phosphatidylethanolamine (PE) N-methylation can influence
the chemicophysical properties of membranes, these agents may affect PE N
methylation. This study was undertaken to examine the effects of propranolol,
acebutolol, and atenolol on PE-N-methylation in rat heart sarcolemma (SL).
METHODS AND RESULTS: Sarcolemmal membrane was isolated from rat hearts by the
hypotonic shock LiBr method. Incorporation of radiolabeled methyl groups from S
adenosyl-l-methionine was assayed at three catalytic sites involved in the PE N
methylation reaction in the presence and absence of these drugs. A biphasic
effect of propranolol at site I was noted; low concentrations (10(-8) M) were
inhibitor. Acebutolol (10(-9)-10(-3) M) depressed methyl group incorporation in
SL at site II in a dose-dependent manner, whereas atenolol showed no effect.
Propranolol also exerted a biphasic effect on sarcoplasmic reticular (SR)
methylation at site I, whereas acebutolol depressed the SR enzyme activity at
site II and atenolol had no effect. The mitochondrial methyltransferase
activities at sites I, II, and III were unaltered by any of these drugs.
CONCLUSIONS: It is suggested that propranolol and acebutolol alter SL and SR PE N
methyltransferase activity at site I and site II, respectively, either by
affecting the enzyme directly or by changing the physiochemical properties of the
membrane.
PMID- 10684505
TI - Analysis of Vasodepressor Responses to Nociceptin and Nociceptin Analogs in the
Systemic Vascular Bed of the Anesthetized Rabbit In Vivo.
AB - Background: The heptadecapeptide nociceptin, also known as Orphanin FQ, is a
recently discovered endogenous ligand for the opioid-like G-protein-coupled
receptor ORL(1). Methods and Results: In the present study, responses to
nociceptin, [Tyr(1)]-nociceptin, nociceptin-(2-17), nociceptin-(1-11), and
nociceptin-(1-7) were compared in the systemic vascular bed of the rabbit.
Nociceptin and [Tyr(1)]-nociceptin induced dose related decreases in systemic
arterial pressure (SAP) when injected in doses of 1-30 nmol/kg intravenous (IV);
in terms of relative vasodepressor activity, [Tyr(1)]-nociceptin and nocicpetin
were similar in potency. However, nocicpetin-(2-17), nocicpetin-(1-11), and
nociceptin-(1-7) had no effect on SAP when injected in doses up to 30 nmol/kg IV.
The decreases in SAP in response to nociceptin and [Tyr(1)]-nociceptin were not
altered by the opioid receptor antagonist naloxone at a time when depressor
responses to methionine-enkephalin were reduced significantly. Conclusions: The
results of the present study show that vasodepressor responses to nociceptin and
[Tyr(1)]-nocicpetin are mediated by the activation of a naloxene-insensitive
opioid receptor and are not dependent on the presence of Phe at the N-terminus of
the nociceptin sequence. Moreover, the present results show that nociceptin-(2
17), nociceptin-(1-11), and nociceptin-(1-7) do not alter SAP in the rabbit,
indicating that peptide chain length is important for the expression of
vasodepressor activity.
PMID- 10684506
TI - Nociceptin Has Vasodilator Activity in the Pulmonary Vascular Bed of the Rat.
AB - BACKGROUND: Recent studies have shown that the newly discovered endogenous opioid
like peptide, nociceptin, has vasodilator activity in the peripheral vascular
bed. However, little if anything is known about the effects of the peptide in the
pulmonary vascular bed. Therefore, responses to nociceptin in the pulmonary
vascular bed were investigated and compared with responses in the hindlimb and
systemic vascular beds of the rat. METHODS AND RESULTS: Responses to nociceptin
were investigated in the pulmonary and hindquarters vascular beds in the rat
under constant flow conditions and were compared with decreases in systemic
vascular resistance. Under conditions of constant flow, injections of nociceptin
in doses of 3-30 nM induced dose-related decreases in pulmonary arterial
perfusion pressure when baseline tone was increased to a high steady level with
U46619. Pulmonary vasodilator responses to nociceptin were not modified by the
opioid receptor antagonist naloxone, and the newly discovered ligand was 10-fold
less potent than adrenomedullin in decreasing pulmonary vascular resistance when
decreases in pulmonary hind quarters and systemic vascular resistances were
compared, nociceptin was significantly more potent in decreasing hindquarters and
systemic vascular resistance than in reducing pulmonary vascular resistance.
CONCLUSIONS: The results of the present study indicate that nociceptin decreases
pulmonary vascular resistance by a naloxone-insensitive mechanism, and that the
peptide is less potent in decreasing pulmonary vascular resistance than in
decreasing systemic vascular resistance in the rat.
PMID- 10684507
TI - Significance and Prevention of Atrial Fibrillation Occurring After Cardiac
Surgery: A Time for Fundamental Change in Strategy?
PMID- 10684508
TI - Risk Factors for Tachycardia Events Caused by Antiarrhythmic Drugs: Experience
From the ESVEM Trial.
AB - BACKGROUND: In the Electrophysiology Study versus Electrocardiographic Monitoring
(ESVEM) trial, up to seven antiarrhythmic drugs were randomly assigned to 486
patients with a history of sustained ventricular arrhythmia. At baseline, all the
patients had inducible sustained ventricular tachycardia (VT) and had >/=10
premature ventricular beats (PVBs) per hour on 48-hour Holter monitoring. A total
of 1,229 drug trials were performed. Antiarrhythmic drugs were discontinued
during hospitalization because of ventricular tachyarrhythmias thought to be a
proarrhythmic effect of the antiarrhythmic drugs in 96 of 479 patients (20%) who
received drugs. Proarrhythmic effects were defined as sustained VT, ventricular
fibrillation or arrhythmic death, torsade de pointes, or distinct intolerable
worsening of the baseline arrhythmia after at least three doses of the drug.
METHODS AND RESULTS: Eighteen baseline characteristics were analyzed for factors
that would predict a higher incidence of proarrhythmia. These included type of
heart disease, previous myocardial infarction, symptom activity scale, gender,
type of arrhythmia, VT/ventricular fibrillation, age, left ventricular ejection
fraction (LVEF), PVB frequency, heart rate, QRS duration, and QT interval.
Multiple logistic regression analysis identified increased mean PVB frequency (P
=.003) and increased heart rate (P =.026) as significant predictors of
proarrhythmia. Decreased LVEF (<25%) exhibited only a trend toward significance
(P =.073). When proarrhythmia was redefined as sustained VT, cardiac arrest of
arrhythmic death, or torsade de pointes (n = 59), PVB frequency (P =.003) and
heart rate (P =.034) were still the only significant baseline predictors.
CONCLUSIONS: In the ESVEM study, higher PVB frequency and higher heart rate were
significant predictors of drug-induced proarrhythmia.
PMID- 10684509
TI - Efficacy of Nicardipine for Long-Term Therapy of Chronic Stable Angina.
AB - BACKGROUND: Although angina is a chronic disease, most clinical trials evaluating
antianginal therapy are of a few weeks or months in duration. METHODS AND
RESULTS: To evaluate the effects of nicardipine, a second-generation dihydro
pyridine calcium channel blocker, as long-term therapy, patients with chronic
stable angina were treated for 1 year with open-label nicardipine. Anginal
symptoms were controlled with 20 mg tid in 24%, 30 mg tid in 34%, and 40 mg tid
in 42%. Of 72 patients completing the 1-year trial, only 14 (19%) had required
the addition of long-acting nitrates for control of symptoms. The remaining 57
patients, who had anginal symptoms controlled with nicardipine alone, were
continued into the 3-week, double-blind period and were randomized to continue
their usual dose of nicardipine or placebo. Throughout the 1-year, open-label
treatment period, the number of anginal episodes and exercise parameters of
angina were significantly reduced with nicardipine. CONCLUSIONS: During the
double-blind period, the patients who continued on nicardipine had significantly
greater exercise time and time to onset of angina than patients who were
randomized to placebo. The exercise parameters in the patients randomized to
placebo were improved over baseline after 1 year of therapy; however, the
improvement with nicardipine was significantly greater.
PMID- 10684510
TI - Effect of Digoxin on Ventricular Remodeling and Responsiveness of beta
Adrenoceptors in Chronic Volume Overload.
AB - BACKGROUND: Digoxin improves baroreflex function and reduces neurohumoral
activation in severe heart failure, but it is uncertain how digoxin affects
ventricular remodeling and progression to left ventricular dysfunction. In
addition, the effect of digoxin in in vitro beta-adrenoceptor density and
function, and contractile reserve in vivo is not well understood. METHODS AND
RESULTS: To study this, we compared digoxin with placebo treatment in rats with
chronic volume overload induced by aortocaval fistula and in sham-operated
control animals. Left ventricular end-diastolic cavity dimensions (LVDd) and wall
thickness were measured weekly by in vivo transthoracic echocardiography, and
left ventricular mass (LVM) and percent fractional shortening (%FS) were
calculated. Six weeks after fistula creation, simultaneous echocardiographic and
invasive hemodynamic evaluation at rest and in response to incremental dobutamine
(1-10 ug/kg/min intravenously) were measured. Myocardial plasma membrane beta
adrenoceptor density and maximal adenylate cyclase responses (V(max)) to
isoproterenol, 5'-guanylylimi dodiphosphate, and forskolin were measured in
vitro. Volume overload induced progressive increases in LVDd and LVM over the 6
week study period. Percent fractional shortening at rest, and the change in %FS
in response to dobutamine stress were dramatically reduced 6 weeks after fistula
creation. Although 6-week fistula animals had unchanged beta-adrenoceptor density
(B(max)) and binding affinity (K(d)) as compared with controls, maximal adenylate
cyclase responses to stimulation in vitro (V(max)) were markedly reduced. Digoxin
treatment prevented this loss of responsiveness of adenylate cyclase but did not
affect beta-adrenoceptor density or affinity in vitro. Digoxin had no effect on
LVDd, LVM, %FS, or the response to dobutamine infusion in vivo. CONCLUSIONS:
Although digoxin prevented beta-adrenoceptor desensitization and improved in
vitro myocardial adenylate cyclase response, the cardiac response to adrenergic
stimulation in vivo was not significantly improved. These results suggest that
the role of beta-adrenoceptor desensitization in the progression from volume
overload hypertrophy to left ventricular dysfunction and heart failure may be
less important than previously thought. Furthermore, although digoxin treatment
did produce modest hemodynamic benefits, it did not prevent progressive
remodeling in this model.
PMID- 10684511
TI - Modification of the ATP-Induced Increase in
AB - BACKGROUND: It is generally accepted that the plasma membrane of mammalian
ventricular myocytes regulates the cytosolic concentration of Ca(2+). In this
study we investigated the effects of some P2-purinoceptor antagonists and metals
such as copper and zinc on the adenosine triphosphate (ATP)-induced increase in
intracellular concentration of free Ca(2+) ([Ca(2+)](i)). METHODS AND RESULTS:
Cardiomyocytes were isolated from adult male Sprague-Dawley rats loaded with Fura
2, and fluorescence measurements were performed by employing stirred cell
suspensions at room temperature. ATP (50 uM) increased [Ca(2+)](i) over the basal
value, and 10 uM cibacron blue or verapamil virtually abolished it. The ATP
induced increase in [Ca(2+)](i) was not observed in Ca(2+)- or Mg(2+)-free
buffers. Incubation of cells with ZnCl(2) produced a significant depression of
the ATP-induced increase in [Ca(2+)](i); 25 uM Zn(2+) decreased the peak response
to approximately 50% of the control value. The ATP-induced increase in
[Ca(2+)](i), was inhibited by low concentrations (1-5 uM) of Cu(2+) but was
markedly augmented by high concentrations (25 uM) of Cu(2+). The increase in the
[Ca(2+)](i) response to cron blue, and Zn(2+), but not by ryanodine or caffeine
pretreatment. CONCLUSIONS: The ATP-induced increase in [Ca(2+)](i) is dependent
on the extracellular concentrations of Ca(2+) as well as Mg(2+) and is
antagonized by cibacron blue and Zn(2+). On the other hand, Cu(2+) produced a
biphasic response to the ATP-induced increase in [Ca(2+)](i) in cardiomyocytes.
PMID- 10684512
TI - Effects of Intracellular Calcium Reduction by Dantrolene on Prevention/Treatment
of Ischemic Stroke.
AB - BACKGROUND: It has been suggested that cerebral blood vessels and brain cells
might depend more on intracellular calcium than extracellular calcium to modulate
intracellular free calcium concentrations, [Ca(2+)](i). METHODS AND RESULTS: A
potent intracellular calcium antagonist, dantrolene, was used to prevent the
ischemic stroke induced in the rat model. It was found that treatment of rats
with dantrolene at -1 hour and +1 hour after 60 minutes of ischemic insult
prevented by the formation of cortical necrosis 98% and 85%, respectively.
Further, the [Ca(2+)](i) of embryonic aorta cells was markedly reduced, and cAMP
of the same cultured cells were significantly increased by dantrolene treatment.
CONCLUSIONS: These results indicate that ischemic stroke is preventable by
dantrolene through reduction of [Ca(2+)](i) and increase of cAMP.
PMID- 10684513
TI - Oxygen Free Radicals and Endotoxic Shock: Effect of Flaxseed.
AB - BACKGROUND: Cardiac dysfunction and tissue injury during endotoxemia may be
caused by increased levels of oxygen free radicals. METHODS AND RESULTS: We
therefore investigated the effects of endotoxic shock on cardiac function and
contractility, plasma creatine kinase (CK) activity and lactate concentration,
oxyradical-producing activity of polymorphonuclear leukocytes (PMNL-CL) and white
blood corpuscles, antioxidant reserve (cardiac chemiluminescence [LV-CL]),
antioxidant enzyme activity (superoxide dismutase, catalase, glutathione
peroxidase), cardiac malondialdehyde (MDA) concentration, a lipid peroxidation
product, and hemodynamics in the absence or presence of flaxseed treatment in
anesthetized dogs. Flaxseed contains lignans that have antioxidant activites and
inhibit platelet-activating factor (PAF). The dogs were assigned to three groups:
group I, sham control; group II, endotoxin (ET) treated (5 mg/kg intravenously);
group III, ET + flaxseed (2 gm/kg/day orally) for 6 days. ET produced a decrease
in cardiac function and contractility and antioxidant enzyme levels, and an
increase in cardiac MDA and LV-CL, PMNL-CL, and plasma CK and lactate.
Pretreatment with flaxseed attenuated the ET-induced cardiac dysfunction and
cellular damage. Protection was incomplete for cardiovascular function, plasma
CK, and lactate. CONCLUSIONS: These results suggest that oxyradicals and/or PAF
may be involved in the deterioration of cardiovascular function and cellular
integrity during ET shock and that antioxidant and anti-PAF agents may be
effective in the treatment of ET shock.
PMID- 10684514
TI - Effects of Metformin on Collagen Glycation and Diastolic Dysfunction in Diabetic
Myocardium.
AB - BACKGROUND: Collagen accumulation in the myocardial interstitium of diabetic
animals is considered to promote diastolic stiffness through advanced
glycosylation. Because in vitro data suggest that metformin can modify
glycosylation, this study was undertaken in a canine diabetic model 4 months in
duration. METHODS AND RESULTS: Untreated diabetics (group II) and diabetics
treated with metformin alone (group III) or with insulin (group IV) were compared
in the basal state and during volume infusion. Basal hemoglobin A(1c), heart
rate, aortic pressure, and ejection fraction were comparable. Left ventricular
end-diastolic pressure was significantly increased in the untreated diabetics of
group II, associated with a reduced end-diastolic volume. By contrast these
parameters in the metformin-treated diabetics of group III were comparable with
those in the normals of group I. Similarly in group IV end-diastolic volume was
higher than that in group II, but filling pressure, although lower, was not
significantly so. Calculation of left ventricular chamber stiffness in the basal
state indicated a higher level for group II compared with controls and the
treatment groups. During the systemic infusion of dextran, the untreated
diabetics of group II had the largest end-diastolic pressure increase and the
smallest rise of end-diastolic volume of the treatment groups, consistent with a
significantly greater chamber stiffness. Myocardial collagen concentration was
increased in group II with an interstitial distribution on morphological exam.
Levels of collagen-linked advanced glycosylation end products isolated from the
left ventricular were significantly greater in group II than in group I.
Treatment with metformin prevented the increment observed in the untreated
diabetic but had no effect on the elevated collagen concentration. CONCLUSIONS:
Untreated diabetics exhibited increased diastolic chamber stiffness associated
with collagen-linked glycation in myocardium compared with control animals.
Chronic metformin use prevented the abnormalities of function and composition.
PMID- 10684516
TI - Controlling Cardiac Arrhythmias: New Drugs in Development and Insights From
Molecular Biology.
PMID- 10684515
TI - Angiotensin-Converting Enzyme Inhibition Delays Onset of Glucosuria With
Regression of Renal Injuries in Genetic Rat Model of Non-Insulin-Dependent
Diabetes Mellitus.
AB - BACKGROUND: The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is a new genetic
model of non-insulin-dependent diabetes mellitus (NIDDM). We investigated whether
angiotensin inhibition influences the onset of NIDDM and brings about a
regression of renal injury in diabetes mellitus. METHODS AND RESULTS: Six-week
old OLETF rats were treated with the angiotensin-converting enzyme (ACE)
inhibitors imidapril or enalapril for 16 weeks. Systolic blood pressure is
increased in an age-dependent manner in OLETF rats. In this study, the elevation
in systolic blood pressure was dose-dependently reduced by ACE inhibitor
treatment. In OLETF rats, plasma concentrations of insulin and glucose increased
and the glucosuria occurred at the age of 22 weeks. Simultaneously, OLETF rats
exhibited proteinuria and nodular lesions in glomeruli. The ACE inhibitor
treatment almost completely reduced glucosuria, and also decreased plasma
concentrations of insulin and glucose in OLETF rats. ACE inhibitor treatment
lessened the proteinuria and attenuated morphologically the severity of nodular
lesions in OLETF rats. Moreover, increases in plasminogen activator inhibitor 1
(PAI-1) in OLETF rats were reduced by the ACE inhibitor treatment, and the
improvement of glomerular lesions was related to decreases of PAI-1 and
angiotensin II levels in plasma but not to improvement of glucose metabolism.
CONCLUSIONS: ACE inhibitors delay onset of NIDDM with attenuation of kidney
injury. The regression of kidney lesions is probably due to angiotensin
reductions but not to glucose metabolism per se. ACE inhibitor drug therapy may
be useful in preventing NIDDM and the subsequent renal injury in patients with
NIDDM.
PMID- 10684517
TI - Editorial Page.
PMID- 10684518
TI - Initiating and Maintaining Patients on Warfarin Anticoagulation: The Importance
of Monitoring.
AB - BACKGROUND: The VA Stroke Prevention in Nonrheumatic Atrial Fibrillation study
was a prospective, randomized, double-blind study comparing low-dose warfarin
with placebo in patients with nonrheumatic atrial fibrillation. The trial showed
a 79% reduction in stroke rate in warfarin randomized patients without an
increase in bleeding complications. We examined the need for frequent prothrombin
time monitoring (international normalized ratios [INR] were not measured
directly) in patients receiving warfarin.
.05). Irbesartan significantly lowered BP without clinically important
changes in renal function. Irbesartan had no effect on 24-hour urinary TXA(2)-M
excretion, but significantly increased 24-hour PGI(2)-M excretion versus placebo
on day B29 (20.7 +/- 23 pg/mg creatinine vs _2.3 +/- 43 pg/mg creatinine; P
<.05). Pharmacokinetics were comparable to those from previous studies. The
hourly relationship between plasma irbesartan concentration and antihypertensive
effect indicated a broad, clockwise hysteresis, with peak concentration occurring
at 1.5 hours, whereas peak antihypertensive effect occurred at 4 hours.
CONCLUSIONS: Irbesartan increases plasma AII and PRA and lowers BP consistent
with AT(1) receptor blockade, without clinically important effects on renal
function.
PMID- 10684526
TI - Prevention of Vascular Apoptosis in Myocardial Infarction by Losartan.
AB - BACKGROUND: Previous studies have demonstrated the occurrence of apoptosis in
cardiomyocytes in different types of cardiovascular diseases. This report
provides the first evidence for the presence of vascular apoptosis in myocardial
infarction induced in rats by occluding the coronary artery for 7 weeks. METHODS
AND RESULTS: Apoptosis was characterized by DNA fragmentation, upregulation of
caspase-3, downregulation of poly (ADP-ribose) polymerase (PARP), increased c-fos
mRNA expression and caspase-3/PARP ratio in aortic vascular smooth muscle cells.
The results show apoptotic changes in 10-25% of the aortic vascular cells after
myocardial infarction; these alterations were prevented after treating the 3-week
operated animals with an angiotensin II receptor antagonist, losartan (25
mg/kg/day; intraperitoneal) for 4 weeks. Cultured rat aortic smooth muscle cells
exposed to 10 nmol/L angiotensin II for 48 hours also exhibited apoptotic
changes, which were inhibited by 10 nmol/L losartan. CONCLUSIONS: These results
suggest that vascular apoptosis occurs in myocardial infarction, and this may be
due to an increase in the circulating levels of angiotensin II.
PMID- 10684527
TI - Effects of Palmitoyl Carnitine on Perfused Heart and Papillary Muscle.
AB - BACKGROUND: Palmitoyl carnitine accumulation during ischemia causes profound
electrophysiological changes, resulting in arrhythmias. We studied the
electrophysiological and contractile effects of palmitoyl carnitine. METHODS AND
RESULTS: Extracellular recordings made by using the endocardial unipolar paced
evoked response (PER) in isolated perfused rabbit hearts were compared with
action potentials (AP) recorded from septal artery perfused rabbit papillary
muscle. Left ventricular pressure was monitored in isolated hearts. In perfused
hearts palmitoyl carnitine (30 umol/L, 30 minutes) significantly (P <.001)
increased the latency of activation (St-R interval) by 58% +/- 8% and reduced
repolarization time (R-E interval) by 39% +/- 4%. PER duration (St-E interval),
was reduced by 30% +/- 3%. Palmitoyl carnitine (30 umol/L) significantly (P
<.001) decreased resting membrane potential (19 +/- 2 mV) of AP, reduced peak
amplitude (33.5 +/- 8 mV) and rate of rise of phase 0 (41 +/- 8 V/s). Significant
reductions (P <.001) in the action potential duration 50% (129.4 +/- 28 ms) and
90% (139.8 +/- 32 ms) were also observed. An initial positive inotropic effect,
which declined as irreversible contracture developed, was also observed.
Verapamil (1 umol/L), nifedipine (1 umol/L), and caffeine (10 mmol/L) failed to
abolish the positive inotropy. CONCLUSIONS: We suggest that palmitoyl carnitine
disrupts intracellular calcium homeostasis leading to disturbances in electrical
and contractile activity. Its accumulation during myocardial ischemia could
contribute to calcium overloading and initiate lethal arrhythmias.
PMID- 10684528
TI - The Effect of Chloroquine on Circulating Platelet Survival in the Rat.
AB - BACKGROUND: Chloroquine inhibits platelet aggregation. Because platelet
aggregation may lead to the lysis of platelets, the effect of chloroquine
administration on circulating platelet survival was studied. METHODS AND RESULTS:
Platelets harvested from the blood of male inbred (WAG) rats were labeled with
(111)Indium oxine and returned to other inbred rats. At timed intervals, blood
samples were drawn from the rats and taken for radioactivity estimation. In some
experiments, the rats (n = 10) received chloroquine (10 mg/kg) intraperitoneally
daily for 3 days. Control rats (n = 10) received chloroquine (10 mg/kg)
intraperitoneally daily for 3 days. Control rats (n = 10) received normal saline.
Indium-labeled platelets disappeared exponentially in control and test rats. The
fraction of indium disappearing/h was significantly less in chloroquine-treated
rats than in control rats (0.0368 +/- 0.0016 vs 0.0520 +/- 0.0016, mean +/- SEM;
P <.001). In all, 99% of the labeled platelets disappeared in 5.3 days in
chloroquine-treated rats and 3.7 days in control rats. CONCLUSIONS: Chloroquine
administration increases the life span of circulating platelets in rats. If the
results are confirmed in humans, chloroquine may prevent the shortened platelet
survival and thrombocytopenia common in malarial infection and other thrombotic
disorders.
PMID- 10684529
TI - Increased Intramural Retention After Local Delivery of Molecules with Increased
Binding Properties: Implications for Regional Delivery of Pharmacologic Agents.
AB - BACKGROUND: Catheter-based local vascular delivery results in concentrated
qualtities of pharmaceutical agents or genes into focal areas of the arterial
wall. However, intramural retention is short and has reduced the potential
efficacy of this approach. It was postulated that agents that possess increased
intramural binding would show increased intramural retention. Platelet-derived
growth factor (PDGF) and basic fibroblast growth factor (bFGF) were models of
agents with increased cellular and extracellular matrix binding properties.
METHODS AND RESULTS: The delivery efficiency and intramural retention of 2 mL of
saline containing I(125) labeled PDGF (n = 35 arteries) and bFGF (n = 24) were
compared with albumin (n = 21) after local delivery into porcine coronary
arteries. Animals were sacrificed at three or more prespecified timepoints:
immediately after delivery, 1 day, or 3 days after delivery and if necessary at 5
or 7 days to document prolonged retention. Autoradiograms of the arterial
sections were evaluated for the extent of delivery. Delivery efficiency, defined
as the amount leaving the catheter and retrieved from the arterial wall, was
0.60% +/- 0.42% for albumin, 1.98% +/- 0.88% for PDGF (P =.001), and 0.31% +/-
0.11% for bFGF. The calculated intramural half-life of albumin was 7.4 hours,
56.2 hours for PDGF, and 14.9 hours for bFGF (P =.0001 for PDGF). Infusate
covering >50% of the medial area was observed in 85% of arteries immediately
after delivery. Although myocardial delivery was similar for albumin, PDGF, and
bFGF, myocardial retention was significantlylonger for bFGF (P <.001).
CONCLUSIONS: Molecules that exhibit preferential intramural binding show a longer
intramural residence duration than solutes without such binding properties. In
addition, delivery and subsequent prolonged retention in the myocardium can be
obtained by local delivery via the arterial lumen of solutions with preferential
binding properties.
PMID- 10684530
TI - Persistence of Atrial Fibrillation After Its Induction-Importance of the Duration
and Dispersion of Atrial Refractoriness and Electrical Remodeling.
AB - BACKGROUND: The electrophysiologic mechanisms of the persistence of atrial
fibrillation (AF) after its initiation are not well understood. Therefore, the
electrophysiologic characteristics of the right atrium were evaluated in an
acute, pacing-induced model of AF in the pig in order to identify parameters
associated with persistence of AF. METHODS AND RESULTS: AF was induced by rapid
atrial pacing in 30 anesthetized, open-chest, juvenile pigs. Sustained (S) AF was
defined as that lasting >10 minutes, nonsustained (NS) AF <10 minutes but >30
seconds, and no (N) AF <30 seconds. Activation mapping and programmed stimulation
(S1S1 = 200 ms) was performed at 56 electrodes on the right atrial free wall, to
determine ERP (mean and minimum), dispersion of refractoriness (ERPdisp,
ELEdisp), conduction velocity (CV), wavelength, AF cycle length (mean of 10
beats), and AF cycle length/time (electrical remodeling). SAF was induced in 10
pigs, NSAF in 9, and NAF in 11. AF cycle length was shorter in SAF and/vs NS vs
NAF (P <.001). Mean ERP (107 +/- 9 and/vs 122 +/- 5 vs 142 +/- 9, p <.001) and
wavelength (7 +/- 1 and/vs 9 +/- 1 vs 11 +/- 1, P <.001) were shorter in SAF
and/vs NSAF vs NAF. Minimum ERP was shorter in SAF and NSAF vs NAF (P <.001). CV
at cycle lengths of 200 and 150 msec was not different between groups. Dispersion
of ERP was greater in SAF and/vs NSAF vs NAF (8 +/- 1 and/vs 11 +/- 1 vs 19 +/-
4, P <.001). CONCLUSIONS: Persistence of AF correlated with shorter ERP and
wavelength, and greater dispersion of ERP and electrical remodeling. There was no
correlation with CV.
PMID- 10684531
TI - Nicotine Increases Spatiotemporal Complexity of Ventricular Fibrillation
Wavefront on the Epicardial Border Zone of Healed Canine Infarcts.
AB - BACKGROUND: The influence of a pharmacologic agent on wavefront dynamics during
ventricular fibrillation (VF) in a setting of remodeled and healed myocardial
infarction (MI) remains poor explored. We hypothesized that nicotine, by virtue
of its complex direct and indirect cardiovascular effects, increases wavefront
complexity during VF. Specifically, we sought to determine whether nicotine
increases the number and complexity (approximate entropy) of wavelets during
stage II VF in hearts with healed MI. METHODS AND RESULTS: The left anterior
descending coronary artery was permanently occluded in five mongrel dogs and
wavefront dynamics during VF studied 5 to 6 weeks after occlusion in the open
chest anesthetized state. VF was induced by rapid pacing and the activation
pattern mapped on the surviving epicardial border zone (EBZ) of the left
ventricle with a plaque (3.2 x 3.8 cm) having 477 bipolar electrodes 1.6 mm
apart. VF was mapped before and 20 minutes after 5 ug/kg/min nicotine infusion.
Nicotine with a mean arterial plasma concentration of 127 +/- 76 ng/mL (range 57
to 240 ng/mL) significantly (P <.01) increased the number of wavelents from 3.8
+/- 0.4 to 5 +/- 0.41. The increased number of wavelets was caused by an increase
(P <.01) in the spontaneous breakup of wavefronts from 4.1 +/- 0.9 times/s to 6.9
+/- 1.1 times/s. Wavebreak over the EBZ was functional in nature as no breakup
occurred during normal sinus rhythm. Approximate entropy, a measure of
complexity, significantly (P <.01) increased after nicotine administration from
0.23 +/- 0.02 to 0.28 +/- 0.01. CONCLUSIONS: Nicotine increases the number of
wavelets and their complexity during VF by promoting spontaneous wavebreak over
the EBZ of healed MI.
PMID- 10684532
TI - Recurrent Torsades de Pointes After Sotalol Therapy for Symptomatic Paroxysmal
Atrial Fibrillation in a Patient with End-Stage Renal Disease.
AB - BACKGROUND: In recent years there has been ain increase in the use of class III
antiarrhythmic drugs such as sotalol, amiodarone, and the so-called pure class
III compound for the control of cardiac arrhythmias. It appears there has been a
corresponding increase in the frequency of torsades de pointes (TdP). METHODS AND
RESULTS: The case reported here, a patient on daily renal dialysis for end-stage
renal disease, has important implications for class III agents, which are
excreted largely by the kidneys. A relatively low dose of sotalol administered
for the prevention of recurrences of atrial fabrillation, with a fast ventricular
response producing angina, led to modest increases in the QT interval and
moderate bradycardia. This culminated in the development of TdP, which
deteriorated into ventricular fibrillation, from which the patient could be
resuscitated with considerable difficulty. Dialysis after the occurrence of TdP
led to further and striking prolongation of the QT interval associated with
numerous episodes of TdP for several days before control was achieved. The atrial
fibrillation and recurrences of TdP were eventually controlled with oral
amiodarone. CONCLUSIONS: This case emphasizes that in the absence of significant
renal function, use of sotalol may not be safe because drug accumulation may not
be controlled adequately with renal dialysis. In view of this, in patients with
end-stage renal disease, the use of sotalol for arrhythmia control appears
contraindicated and alternative agents, the excretion of which does not occur by
the renal route, should be used.
PMID- 10684533
TI - Increase in Plasma Angiotensin II Levels After Chemical Blockade of AT1 Receptor
Blockers, But Not With Antisense Oligodeoxynucleotide Directed at AT1 Receptor
mRNA: A Major Benefit of Gene Therapy.
PMID- 10684534
TI - Protamine Reversal of Heparin After Cardiopulmonary Bypass Increases Lung
Resistance, Not Elastance.
AB - BACKGROUND: Protamine, an immunologically active, cationic amine, has been
suspected of impairing lung mechanics when administered after cardiopulmonary
bypass (CPB) to reverse heparin. Whether such adverse changes are an effect of
protamine itself, the formation of heparin-protamine complexes, the extent of
heparin anticoagulation, or its chemical reversal is not known. METHODS AND
RESULTS: Using a computer-controlled, forced-ventilation method over a variety of
physiological tidal volume (V(T)) and frequency (f) combinations, we
prospectively studied 18 adult, elective patients before systemic heparinization
and after protamine reversal to confirm and, possibly, elucidate an etiology for
any adverse pulmonary effects. Protamine and heparin doses, their sum (Sigma
dose) and differential (Delta-dose) doses, and activated clotting times were
tabulated. In all patients, lung resistance (R(L)) and, to a lesser extent,
elastance (E(L)) increased after CPB, compared with pre-CPB values (P <.05).
However, R(L) particularly increased after CPB with increases correlated to the
Delta-dose, where R(LPRE-->POST) = -0.037 [Delta-dose] - 0.56f ?_ 0.019V(T) +
36.1 (r =.652, P <.05). No other significant correlations were found among the
remaining clinical parameters and changes in either R(L) or E(L), or any chest
wall component (all P >.05). CONCLUSIONS: The changes seen in R(L) after CPB were
greatest in those patients receiving the most nearly balanced doses of heparin
and protamine, and were not related significantly to the total heparin or
protamine doses, or their sum. These suggests that the extent of anticoagulation
reversal or formation of heparin-protamine complexes, and not protamine itself,
are more responsible for changes seen in lung mechanics. The changes seen were
limited solely to R(L), and not in either E(L) nor the chest wall mechanical
properties.
PMID- 10684535
TI - Concomitant Block of the Rapid (I(Kr)) and Slow (I(Ks)) Components of the Delayed
Rectifier Potassium Current is Associated With Additional Drug Effects on
Lengthening of Cardiac Repolarization.
AB - BACKGROUND: The delayed rectifier potassium current, which comprises both a rapid
(I(Kr)) and as slow (I(Ks)) component, is a major outward current involved in
repolarization of cardiac myocytes. I(Kr) is the target of most drugs that
prolong repolarization, whereas electrophysiological effects resulting from
combined block of I(Kr) and I(Ks) still need to be characterized. METHODS AND
RESULTS: Studies in isolated, buffer-perfused guinea pig hearts were undertaken
to compare lengthening of cardiac repolarization under conditions of I(Kr) block
alone, I(Ks) Block alone, or combined block of I(Kr) and I(Ks). In protocol A,
isolated perfusion with N-acetylprocainamide (NAPA) (I(Kr) block), indapamide
(I(Ks) block), or combined NAPA/indapamide was performed at a pacing cycle length
of 250 msec. Increases in monophasic action potential duration measured at 90%
polarization (MAPD(90)) from baseline after perfusion with NAPA 100 umol/L
(IC(50) for block of I(Kr)) was 19 +/- 6 msed (P <.05), after indapamide 100
umol/L (EC(50) for block of I(Ks)) 13 +/- 2 msec (P <.05), but 42 +/- 5 msec
after combined NAPA 100 umol/L and indapamide 100 umol/L (P <.05 vs. baseline and
isolated administrations), suggesting the possibility of excessive lengthening of
cardiac repolarization by blocking both I(Kr) and I(Ks). As well, in protocol B
where sequential perfusions with dofetilide (I(Kr) blocker),
dofetilide/indapamide, and indapamide in the same hearts were used, combined
dofetilide/indapamide infusion showed a greater increase in MAPD(90) during all
pacing cycles studied (250 to 150 msec). CONCLUSIONS: Combined I(Kr) and I(Ks)
block may lead to excessive lengthening of cardiac repolarization. This may
predispose patients to proarrhythmia during coadministration of drugs.
PMID- 10684536
TI - The Effect of Agmatine on Ischemic and Nonischemic Isolated Rat Heart.
AB - OBJECTIVE: the natural polyamines play a protective role during ischemic injury.
We studied the effects of agmatine on ischemic and nonischemic isolated rat
hearts. METHODS: Thirty-one rats were randomly assigned to one of four
experimental groups. Sixteen rats were injected with saline (group 1, n = 9;
group 3, n = 7), and 15 rats were injected with 100 mg/kg of agmatine (group 2, n
= 8; group 4, n = 7). Injections were given twice: 24 hours and 1 hour before the
experiment. Using the modified Langendorf model, rat hearts were perfused with
Krebs-Henseleit solution for 105 minutes during phase 1 of the experiment (groups
1 and 2). During phase 2, hearts were exposed to 45 minutes of global ischemia
(groups 3 and 4). RESULTS: During phase 1, no statistically significant
differences were observed between the agmatine and the control groups. During
phase 2, agmatine caused a significant increase in left ventricular pressure (P
<.003). At the end of reperfusion, P(max) was 111% +/- 10% from the baseline
levels versus only 82% +/- 5% in the control group. After 20 minutes of
reperfusion, dP/dt (first-time derivative of the ventricular pressure) in the
agmatine group reached full recovery of 106% +/- 12% versus only 64% +/- 14% in
the saline group (P =.059). Agmatine also caused a significant increase in
coronary flow rate (P <.004) throughout the reperfusion period. Quantitative
immunohistochemical staining disclosed reduced cell damage in the agmatine
treated hearts (P <.02) versus the control group. CONCLUSION: Agmatine injection
given before induced ischemia improves hemodynamic recovery by mechanisms that
may be attributed to its vasodilatory properties.
PMID- 10684537
TI - Domoic Acid Attenuates the Adenosine-5'-Triphosphate-Induced Increase in
AB - BACKGROUND: Although domoic acid (DA), a shellfish neurotoxin, carries a negative
surface charge at physiological pH like that of adenosine-5'-triphosphate (ATP),
very little is known about its cellular effects. In view of the potentially
significant role of extracellular ATP as a signaling molecule for increasing the
intracellular concentration of Ca(2+) ([Ca(2+)](i)), we examined the possibility
that DA may interfere with this signal transduction mechanism in the myocardium.
METHODS AND RESULTS: Cardiomyocytes were isolated from rat heart and loaded with
Fura-2 to measure the [Ca(2+)](i). ATP produced a gradual rise in [Ca(2+)](i),
reaching a peak level in 25-30 seconds and declining thereafter. DA did not
affect the [Ca(2+)](i) in cardiomyocytes; however, it diminished the ATP-induced
elevation in [Ca(2+)](i) in the concentration-dependent manner. Kainic acid, an
analogue of DA, had a similar effect but at a 25-fold higher concentration,
whereas glutamate and aspartate did not modify the action of ATP. Well-known
inhibitors of L-type voltage-sensitive Ca(2+) channels, nifedipine and
nicardipine, depressed the ATP-induced increase in [Ca(2+)](i), but DA did not
produce additive effects with either of these agents. On the other hand, DA
potentiated the KCl-induced increase in [Ca(2+)](i) in quiescent cardiomyocytes
and augmented the nicardipine-sensitive Ca(2+) transients in electrically
stimulated cardiomyocytes. CONCLUSIONS: These results suggest that DA may
diminish the ATP-induced increase in [Ca(2+)](i) by inhibiting the ATP
interaction with cardiomyocytes in a specific manner.
PMID- 10684538
TI - Sustained Intramural Retention and Regional Redistribution Following Local
Vascular Delivery of Polylactic-Coglycolic Acid and Liposomal Nanoparticulate
Formulations Containing Probucol.
AB - BACKGROUND: Probucol reduces restenosis after angioplasty, provided oral
administration is begun 1 month before the procedure. Local vascular delivery of
a nonoparticulate formulation of probucol may obviate the need for drug loading
by acutely raising arterial intramural concentration while providing sustained
intramural retention. To test this hypothesis, we compared the retention and
redistribution of (35)S-probucol encapsulated in either liposomal or polylactic
coglycolic acid (PLGA) nanoparticles after local vascular delivery. METHODS:
Nanoparticles were delivered using a Crescendo microporous infusion catheter
(Cordis, Warren, NJ) after balloon angioplasty of rabbit iliac arteries (n = 12
18 arteries per formulation per time point). Animals were euthanized on day 0, 3,
or 7 after delivery. Iliac arteries, perivascular fat, and downstream tissues
were harvested and the radioactivity disintegrations per minute was measured.
Autoradiographic and confocal microscopic analyses of tissue sections were
performed to evaluate intramural distribution of probucol. RESULTS: Immediately
after delivery, radioactivity in the iliac arteries (log[dpm/mg], mean +/- SEM)
was greater with PLGA (2.72 +/- 0.08) than with liposomal encapsulation (2.10 +/-
0.08, P = 0.001). Intramural retention of probucol was 23% at 7 days using
liposomes and 10% using PLGA, corresponding to a probucol concentration of 0.1
ng/mg tissue for both formulations. By the third day after delivery,
radioactivity in peri-iliac fat, femoral arteries, and hindlimb muscle increased
by 88%, 29%, and 154%, respectively. Thereafter, radioactivity decreased to 56%,
43%, and 134% of initial dpm respectively, by day 7. CONCLUSIONS: although
delivery efficiency was superior with PLGA encapsulation, intramural probucol
concentrations were similar on day 7 using both formulations. Radial and axial
redistribution of probucol was observed, indicating that this technique can be
exploited to increase adjacent tissue delivery.
PMID- 10684539
TI - Nifedipine and Bay K 8644 Induce an increase of
AB - BACKGROUND: The dihydropyridine-induced vasorelaxation is partly dependent on the
endothelium, which does not express L-type calcium channels. Because nitric oxide
(NO) is one of the most important endothelium-derived vasorelaxing factors, we
investigated how the calcium antagonist nifedipine and the calcium agonist Bay K
8644 modulate intracellular calcium and NO formation in porcine endothelial
cells. METHODS AND RESULTS: NO formation of porcine aortic endothelial cell
cultures and of native endothelium of intact porcine coronary arteries was
measured with an electrochemical electrode, and the intracellular concentration
of Ca(2+) [Ca(2+)](i) was evaluated using the Fura-2 technique. Nifedipine
induced a concentration-dependent [0,01-1 umol/L] increase in [Ca(2+)](i) and NO
formation in cultured porcine aortic endothelial cells, and moreover a dose
dependent NO formation in native endothelial cells from intact porcine coronary
arteires, which was higher than in cultured cells. This effect was inhibited by N
nitro-l-arginine, a specific NO synthase inhibitor. Bay K 8644 caused a
[Ca(2+)](i) increase and NO release in cultured cells, too, although to a lesser
extent. Nifedipine-induced and Bay K 8644-induced [Ca(2+)](i) rise could be
blocked by removal of extracellular calcium, indicating that a calcium influx may
be involved. CONCLUSIONS: The calcium antagonist nifedipine as well as the
calcium agonist Bay K 8644 cause an increase of [Ca(2+)](i) and NO in porcine
endothelium. Therefore, these effects seem to be related to the dihydropyridines
as a substance class, which may explain the endothelial component in
dihydropyridine-induced vasorelaxation.
PMID- 10684540
TI - Electrophysiologic and Antiarrhythmic Effects of Propafenone: Focus on Atrial
Fibrillation.
PMID- 10684541
TI - Intravenous Amiodarone in the Management of Atrial Fibrillation.
AB - BACKGROUND: Although approved only for therapy of life-threatening ventricular
tachyarrhythmias, intravenous amiodarone is also being used for the treatment of
atrial fibrillation (AF), generally in the intensive care unit setting and most
often after cardiac surgery. When used for AF, dosing regimens and clinical
experience have varied. METHODS AND RESULTS: This article summarizes
representative reports in hopes of clarifying the role of intravenous amiodarone
for practitioners who prescribe it for the management of AF. The most immediate
and most predictable response is reduction of the ventricular rate, which
generally is noted after the first 300-400 mg. Restoration of sinus rhythm
(cardioversion) may occur, but the precise incidence in a placebo-controlled,
blinded study has not been determined. When present, it often takes 24 hours, and
a total dose of 1,000 mg or more. Least certain is the efficacy of the drug in
preventing the appearance (when used prophylactically) or reappearance of AF.
CONCLUSIONS: More data are required with regard to patient characterization,
electrical system status, and dosing regimen to better characterize intravenous
amiodarone for this role.
PMID- 10684542
TI - Clinical Pharmacology of Carvedilol.
AB - BACKGROUND: There is now a wealth of data supporting the use of beta-blockers in
heart failure and the additional pharmacological properties of carvedilol are
thought to play an important role in the therapeutic efficacy of carvedilol in
this disease. METHODS AND RESULTS: Carvedilol is licensed for the treatment of
essential hypertension, chronic stable angina, and mild to moderate chronic heart
failure. This article provides an up-to-date review of the clinical pharmacology
of carvedilol, with particular emphasis on its clinical effects in heart failure.
CONCLUSION: Carvedilol is a multiple-action neurohormonal antagonist that offers
nonselective beta-blockade, alpha-1 blockade, antioxidant, anti-ischemic
mortality, and anti-proliferative properties. In addition to reductions in
hospitalization and mortality rates, benefits of carvedilol in heart failure
include dramatic improvements in left ventricular function and other parameters
of cardiac remodeling.
PMID- 10684543
TI - Relative Effects of alpha- and gamma-Tocopherol on Low-Density Lipoprotein
Oxidation and Superoxide Dismutase and Nitric Oxide Synthase Activity and Protein
Expression in Rats.
AB - BACKGROUND: Increasing evidence suggests that vitamin E prevents the progression
of atherosclerosis by inhibiting platelet aggregation, monocyte adhesion, and
improving plaque stability and vasomotor function. Recently, controversy has
arisen as to the relative effects of alpha- and gamma-tocopherol in modulating
some mediators of atherosclerosis. METHODS AND RESULTS: We examined the effects
of alpha- and gamma-tocopherol on constitutive nitric oxide synthase (cNOS) and
superoxide dismutase (SOD) activity and protein expression in rats. Sprague
Dawley rats were fed regular chow or chow mixed with alpha- or gamma-tocopherol
(100 mg/kg/day) for 7 to 10 days. Plasma alpha- and gamma-tocopherol levels, low
density lipoprotein (LDL) oxidation, and cNOS and SOD activity and protein
expression were measured. Plasma alpha-tocopherol levels were significantly
increased (eP <.01 vs control), but gamma-tocopherol levels fell (P <.01 vs
control) in rats fed alpha-tocopherol. Plasma gamma-tocopherol levels were
increased (P <.01 vs control), and alpha-tocopherol levels did not change in rats
fed gamma-tocopherol. Both alpha- and gamma-tocopherol feeding decreased the rate
of LDL oxidation induced by phorbol 12-myristate 13-acetate (PMA)-stimulated
leukocytes (P <.01 vs control). Both alpha- and gamma-tocopherol increased SOD
activity in plasma and arterial tissues as well as Mn SOD and Cu/Zn SOD protein
expression in arterial tissues (all P <.01 vs control). gamma-Tocopherol was more
potent than alpha-tocopherol in all these effects (P <.05). Both a- and gamma
tocopherol increased NO generation and cNOS activity (all P <.05 vs control).
However, only gamma-tocopherol increased cNOS protein expression. CONCLUSIONS:
These observations indicate that whereas both alpha- and gamma-tocopherol exert
important effects on determinants of oxidationand vasomotor function, effects of
dietary gamma-tocopherol supplementation in vivo are less pronounced than those
of gamma-tocopherol supplementation.
PMID- 10684544
TI - Endothelium-Independent Relaxation of Vascular Smooth Muscle by 17beta-Estradiol.
AB - BACKGROUND: Estrogens directly dilate arteries, and this acute relaxation of
vascular smooth muscle (VSM) may contribute to the cardioprotective effect of
this important hormone. However, the mechanism by which estrogens relax VSM is
not clear. METHODS AND RESULTS: Based on observations in isolated smooth muscle
cells, we hypothesized that 17beta-estradiol (E(2)) causes dilation through
receptor-mediated activation of K(+) channels in VSM cells. To test this
hypothesis, E(2)-relaxation was studied in arteries from male Sprague-Dawley
rats. We observed that the estrogen receptor antagonist, tamoxifen (3 umol)
attenuated E(2) relaxation, suggesting that at least a portion of the relaxation
depends on activation of E(2) receptors. The nitric oxide synthase inhibitor,
Nomega-nitro-larginine (100 umol) did not affect E(2) relaxation in either
denuded or endothelium-intact arterial strips. Furthermore, inhibition of
guanylyl cyclase with LY83583 (10 umol) had no effect on the relaxation,
suggesting that nitric oxide does not contribute to this relaxation. Vascular
segments contracted with 90 mmol KCl to disrupt the K(+) gradient had a similar
E(2) relaxation does not require K(+)-channel activation. Finally, E(2)
pretreatment inhibited contraction of arterial segments depleted of intracellular
calcium but in the presence of extracellular calcium. However, E(2) did not
affect contraction of strips in calcium-free solution. CONCLUSIONS: These final
experiments suggest that E(2) inhibits Ca(2+) influx but not intracellular
calcium release. Together, these studies establish that E(2) causes receptor
mediated relaxation of peripheral resistance arteries through inhibition of
calcium entry independent of nitric oxide production, guanylyl cyclase
stimulation, and K(+)-channel activation.
PMID- 10684545
TI - Hypoxic Hypoperfusion Fails to Induce Myocardial Hibernation in Anesthetized
Swine.
AB - BACKGROUND: Congenital origin of the left coronary artery from the pulmonary
artery (ALCAPA) results in chronically dysfunctional myocardium with the partial
ability to recover after revascularization. We attempted to establish an ALCAPA
syndrome in anesthetized pigs for 24 hours and to compare it with stunned and
infarcted myocardium. METHODS AND RESULTS: In group 1 (n = 12), a bypass graft
was interposed between the pulmonary artery and the left anterior descending
coronary artery (LAD). Reduction of flow in the LAD with gradual increases in
flow from the pulmonary artery resulted in an incremental reduction of segment
shortening (8.9 +/- 5.3% at 24 hours vs 26.6 +/- 10% at baseline, P <.005). In
group 3 (n = 5), 2 cycles of 10-minute LAD occlusion resulted in decreased
segment shortening with slow recovery (at 24 hours 18.7 +/- 1.3% vs 24.2 +/- 4%
at baseline, segment shortening with slow recovery (at 24 hours 18.7 +/- 1.3% vs
24.2 +/- 4% at baseline, P <.05). In group 3 (n = 6), 1-hour LAD occlusion
reduced segment shortening at 24 hours to 4.7 +/- 5.2% (P <.005 vs baseline).
Histological analysis of the LAD territory revealed severe degeneration,
myolysis, and alteration of the chromatin structure in group 1 comparable to
ischemic cell death in group 3, whereas control areas and the LAD area in group 2
showed only minor structural alterations. Infarct size/risk area, as measured by
tetrazolium staining, was 49.8 +/- 11.2% in group 1, 9.3 +/- 8.1% in group 2 (P
<.005), and 60.3 +/- 9% in group 3. CONCLUSION: Hypoxic myocardial hypoperfusion
from the pulmonary artery results in myocardial necrosis in anesthetized pigs.
These findings are in contrast to the concept of myocardial hibernation in the
ALCAPA syndrome because in this model, hypoxic hypoperfusion failed to induce
adaptation to preserve myocardial structure.
PMID- 10684546
TI - Superoxide Anion Generation, Superoxide Dismutase Activity, and Nitric Oxide
Release in Human Internal Mammary Artery and Saphenous Vein Segments.
AB - BACKGROUND: Internal mammary artery (IMA) as conduit for a coronary artery bypass
graft (CABG) stays patent longer and more often than saphenous vein (SV).
However, the precise differences in the biology of IMA and SV are unclear.
METHODS AND RESULTS: To examine inherent difference in superoxide anion,
superoxide dismutase (SOD) and nitric oxide (NO) formation in IMA and SV as a
basis for differences in patency rates, we measured these parameters in vascular
segments of patients undergoing CABG. Superoxide anion generation was measured by
lucigenin chemiluminescence and reduction of cytochrome c, SOD by inhibition of
pyrogallol auto-oxidation, and No as nitrite/nitrate fluorometrically using 2-3
diaminonaphthalene as a probe. Generation of superoxide anion, SOD activity, and
No formation were all greater in the IMA than in the SV segments (IMA:SV = 2.6:1,
2.9:1, 1, and 3.0:1, respectively, all P <.010. There was a positive correlation
between superoxide anion generation and SOD activity (r = 0.65, P <.05; r = 0.70,
P <.05 in IMA and SV, respectively) and NO release (r = 0.68, P <.05; r = 0.75, P
<.03 in IMA and SV, respectively). Western blot analysis showed no differences in
SOD and NO synthase protein expression in IMA and SV segment homogenates. To
examine whether greater superoxide anion generation, SOD activity, and NO
formation are unique to IMA, we studied pulmonary artery (PA) and pulmonary vein
(PV) segments taken from patients undergoing lung resection. Superoxide anion
generation, SOD activity, and NO formation were also found to be greater in PA
than in PV segments. CONCLUSIONS: Inherently greater superoxide anion generation
and subsequently increased formation of SOD and NO release in IMA (vs SV) may be
a factor in the greater patency of the former as CABG conduit. Because both IMA
and PA are exposed to pulsatile stretch and cary blood at higher pressure than
the SV and PV, it is likely that these 2 factorsd account for the observed
differences.
PMID- 10684547
TI - Viagra and Cardiovascular Disease.
AB - BACKGROUND: The introduction of the drug sildenafil (Viagra; Pfizer, New York,
NY) into the armamentarium for treatment of erectile dysfunction is a major
advance. Many of the patients who will benefit from its use have cardiovascular
disease. Erectile dysfunction and cardiovascular disease share common risk
factors. Although the metabolic demands of sexual activity are modest and the
associated risk for coronary events is low, the clinician caring for cardiac
patients needs to be aware of the pharmacology and hemodynamic profile of
sildenafil in those with heart disease who use cardioactive drugs. METHODS AND
RESULTS: We reviewed the current literature relating to the pharmacology,
hemodynamic profile, efficacy, safety, and clinical application of sildenafil in
patients with cardiovascular disease. Sildenafil is highly effective in the
treatment of erectile dysfunction. The overall incidence of cardiovascular
adverse events is low and similar to placebo. Current postmarketing data do not
suggest an increase in cardiovascular death in sildenafil users. The drug is
contraindicated in those taking organic nitrates. It should be used with caution
and on an individual basis in patients who have active coronary ischemia and
heart failure with tenous blood pressure and volume status. CONCLUSIONS: When
used with discretion, sildenafil is safe, effective, and has the potential to
greatly enhance quality of life in the relatively large proportion of the
population with heart disease.
PMID- 10684548
TI - Primary Hyperparathyroidism and Polymorphic Ventricular Tachycardia.
AB - BACKGROUND: Primary hyperparathyroidism is a rare but important cause of
ventricular arrhythmias. METHODS AND RESULTS: The medical records of a patient
with primary hyperparathyroidism and polymorphic ventricular tachycardia was
reviewed. The patient was serially interviewed and examined before and after
parathyroidectomy. A literature search was performed. The association of primary
hyperparathyroidism and polymorphic ventricular tachycardia is rare. Hypokalemia
and hypomagnesemia occur infrequently in primary hyperparathyroidism.
CONCLUSIONS: The potential for malignant ventricular arrhythmias in the setting
of primary hyperparathyroidism must be recognized.
PMID- 10684549
TI - Preface
PMID- 10684550
TI - Endoscopic treatments for Zenker's diverticulum.
PMID- 10684551
TI - Cardiomyotomy.
AB - During the last decade, minimally invasive surgery has replaced open surgery in
the treatment of esophageal achalasia. This new approach, in fact, determines
results similar to the open approach, but is associated to a shorter hospital
stay, minimal postoperative discomfort, and faster return to regular activity.
Between 1991 and 1998, 168 patients underwent a cardiomyotomy by minimally
invasive techniques. Good or excellent results were obtained in 85% of patients
after thoracoscopic myotomy, and 93% of patients after laparoscopic myotomy and
partial fundoplication. The latter procedure was followed by a lower incidence of
postoperative gastroesophageal reflux (60% versus 17%). Laparoscopic Heller
myotomy and partial fundoplication has emerged as the procedure of choice for
esophageal achalasia, and it should be considered today the primary form of
treatment for this disease.
PMID- 10684552
TI - Current state, techniques, and results of laparoscopic antireflux surgery.
AB - The introduction of laparoscopic fundoplication has dramatically changed the face
of antireflux surgery. Central to the success of laparoscopic fundoplication is
careful preoperative patient evaluation and attention to surgical technique.
Emerging evidence has questioned the long-term durability of laparoscopic partial
fundoplications underscoring the place of laparoscopic Nissen fundoplication as
the procedure of choice for most patients. The technique of laparoscopic Nissen
fundoplication should incorporate crural closure, complete fundic mobilization by
short gastric vessel division, and the creation of a short, loose fundoplication
by enveloping the anterior and posterior fundic walls around the esophagus.
Relief of typical reflux symptoms can be anticipated in over 90% of patients. The
outcome of atypical reflux symptoms is less predictable, on average two thirds of
patients benefiting. The cost of laparoscopic fundoplication compares favorably
to long-term medical therapy and open fundoplication. Current trends indicate
that laparoscopic fundoplication is being used increasingly as an alternative to
long-term medical therapy.
PMID- 10684553
TI - Laparoscopic treatment of large hiatal hernias.
AB - Large hiatal or paraesophageal hernias constitute between 5% and 10% of all
hiatal hernias. This hernia is a potential threatening complication, and a timely
operative correction should be performed in all patients with an acceptable risk.
Based on the lessons learned from conventional approach, laparoscopic treatment
has confirmed the initial good results with all advantages of laparoscopic
surgery. Reduction of the hernia, excision of the sac, and approximation of the
hiatus followed by selective use of an antireflux procedure and some form of
gastropexy constitute the operative steps to obtain optimal postoperative
results.
PMID- 10684554
TI - Laparoscopic gastric drainage procedures.
AB - Gastric outlet obstruction continues to be an indication for drainage despite the
common use of powerful proton pump inhibitors. Minimal invasive surgery
techniques now play a significant role in the treatment of this pathology.
Complicated peptic ulcer disease and cancer are the two most common causes. To
accomplish drainage, advanced laparoscopic techniques are required. A variety of
procedures are possible, and these are discussed in detail in this report. The
advantages of the laparoscopic approach have been realized in this group of
patients.
PMID- 10684555
TI - Ultrasonic dissectors and minimally invasive surgery.
AB - As increasingly complex operations are performed laparoscopically, new problems
arise regarding basic tasks such as dissection and retraction. Emerging
technologies continue to reduce the technical demands of minimally invasive
surgery. Recent studies have shown that ultrasonic devices have the potential to
replace electrocautery without compromising safety in minimally invasive
operations. With the combination of several functions into a single instrument,
significant reductions in operative time and expense are possible and should
increase the acceptance of this new technology.
PMID- 10684556
TI - Immunocytochemical localization of actin and tubulin in the integument of land
crab (Gecarcinus lateralis) and lobster (Homarus americanus).
AB - The crustacean integument consists of the exoskeleton and underlying epithelium
and associated tissues. The epithelium, which is composed of a single layer of
cells, is responsible for the cyclical breakdown and synthesis of the exoskeleton
associated with molting (ecdysis). During premolt (proecdysis) the epithelial
cells lengthen and secrete the two outermost layers (epicuticle and exocuticle)
of the new exoskeleton while partially degrading the two innermost layers
(endocuticle and membranous layer) of the overlying old exoskeleton. This
increased cellular activity is associated with increased protein synthesis and a
change in cell shape from cuboidal to columnar. The cytoskeleton, composed of
microfilaments (actin) and microtubules (tubulin), plays important roles in the
intracellular organization and motility of eukaryotic cells. Immunoblot analysis
shows that the land crab exoskeleton contains actin, tubulin, and actin-related
proteins (Varadaraj et al. 1996. Gene 171:177-184). In the present study,
immunocytochemistry of land crab and lobster integument showed that both proteins
were localized in various cell types, including epithelia, connective tissue,
tendinal cells, and blood vessels. Muscle immunostained for actin and myosin, but
not for tubulin. The membranous layer of land crab (the other layers of the
exoskeleton were not examined) and membranous layer and endocuticle of lobster
also reacted specifically with anti-beta-actin and anti-alpha-tubulin monoclonal
antibodies, but not with an anti-myosin heavy chain antibody. During proecdysis
immunolabeling of the membranous layer decreased probably due to protein
degradation. The staining intensity for actin and tubulin in the proecdysial
epithelium was similar to that in the intermolt (anecdysial) epithelium,
suggesting that there was a net accumulation of both proteins proportional to the
increase in cellular volume. These results support the previous biochemical
analyses and, more specifically, localize actin and tubulin in exoskeletal
structures, suggesting that they may serve both intracellular and extracellular
functions in crustaceans. J. Exp. Zool. 286:329-342, 2000.
PMID- 10684557
TI - Intra- and extracellular dehydration has no effect on plasma levels of
angiotensin II in an amphibian.
AB - Previous studies have demonstrated that both dehydration (intra and
extracellular) and treatment with angiotensin II (A-II) induce changes in thirst
related behavior in the spadefoot toad, Scaphiopus couchii. One of the steps in
determining a causal relationship between a hormone and a behavior is to
determine that there is association between an animal's performance of the
behavior and changes in endogenous hormonal concentrations. The hypothesis tested
that plasma levels of the peptide hormone A-II would change as a result of
dehydration known to induce water absorption response (WR) behavior in the
spadefoot toad. Plasma samples were taken from toads dehydrated intracellularly
by injection of hypertonic solutions of NaCl or sucrose at levels known to induce
WR behavior. As an osmotic control, a group of animals was injected with urea,
which has been demonstrated to not induce WR behavior. In order to determine the
effects of extracellular dehydration on plasma, A-II levels in toads dehydrated
by plasma volume depletion via cardiac puncture were compared to sham-punctured
controls. None of the treatments in any experiment resulted in significant
differences in plasma levels of angiotensin II among groups sampled at the time
when WR behavior occurs. These results do not support the hypothesis that
dehydration-induced thirst is stimulated by changes in plasma A-II concentrations
at the onset of WR behavior. J. Exp. Zool. 286:343-349, 2000.
PMID- 10684558
TI - Anatomy and physiology of neurons composing the commissural ring nerve of the
cricket, Acheta domesticus.
AB - The commissural ring nerve (RN) of the cricket Acheta domesticus links together
the two cercal motor nerves of the terminal abdominal ganglion. It contains the
axons of almost 100 neurons including two bilateral clusters of eight to 13
ventrolateral neurons and approximately 75 neurons with midline somata within the
terminal abdominal ganglion. The ventrolateral neurons have an ipsilateral
dendritic arborization within the dorsal neuropil of the ganglion and their axons
use the RN as a commissure in order to enter the contralateral nerves of the
tenth ganglionic neuromere. In contrast, most midline neurons have bifurcating
axons projecting bilaterally into the neuropil of the ganglion as well as into
the RN where they often branch extensively before entering the contralateral
tenth nerves. Most RN neurons have small, non-spiking somata with spike
initiation zones distant from the soma. Many midline neurons also produce double
peaked spikes in their somata, indicative of multiple spike initiation zones.
Spontaneous neuronal activity recorded extracellularly from the RN reveals
several units, some with variable firing patterns, but none responding to sensory
stimuli. The RN is primarily composed of small (50 nm diameter) axon profiles
with a few large (0.5-1 microm diameter) profiles. Occasionally, profiles of
nerve terminals containing primarily small clear vesicles and a few large dense
vesicles are observed. These vesicles can sometimes be clustered about an active
zone. We conclude that the primary function of the RN is to serve as a peripheral
nerve commissure and that its role as a neurohemal organ is negligible. J. Exp.
Zool. 286:350-366, 2000.
PMID- 10684559
TI - Triggering of cryoprotectant synthesis in the woolly bear caterpillar
(Pyrrharctia isabella Lepidoptera: Arctiidae).
AB - Isabella tiger moths (Pyrrharctia isabella) overwinter as caterpillars (i.e.,
woolly bears) that can survive freezing at moderate subzero temperatures. We
observed an increase in hemolymph osmolality for field-collected woolly bears
during October (325 +/- 47 to 445 +/- 27 mOsmol/liter) and tested the influence
of temperature and moisture levels on cryoprotectant production. Laboratory
acclimation was done at 5 degrees C in moist conditions and at 25 degrees C
acclimation in both dry and moist conditions. Body water contents were diminished
by dehydration at 25 degrees C for 4 days (57 +/- 4%). Caterpillars collected in
early October did not alter their hemolymph osmolality during cold acclimation,
but caterpillars increased by 45% (to 647 +/- 90 mOsmol/liter) after 4 days at 5
degrees C following their collection in late October. Hemolymph composition was
markedly changed in caterpillars experiencing dehydration at 25 degrees C (1042
+/- 200 mOsmol/liter; 507 +/- 225 mmol glycerol/liter), whereas caterpillars
showed no change in their hemolymph composition when kept moist at 25 degrees C.
Our experiments reveal that both dehydration and cold acclimation rapidly induce
cryoprotectant synthesis in P. isabella caterpillars. J. Exp. Zool. 286:367-371,
2000.
PMID- 10684560
TI - Food chemical discriminations by an herbivorous lizard, Corucia zebrata.
AB - Adjustment of chemosensory response to diet should be apparent in evolutionary
changes corresponding to dietary shifts. Because most lizards are generalist
predators of small animals, relationships between chemosensory behavior and diet
are difficult to detect. Nevertheless, the evolution of herbivory by a small
number of lizards provides an opportunity to detect any corresponding change in
response to plant chemicals. I studied tongue-flicking and biting by the large,
herbivorous scincid lizard Corucia zebrata in response to chemical cues from
crickets, romaine lettuce, and control stimuli presented on cotton swabs. The
skinks exhibited significantly stronger response to plant and animal chemicals
than to controls for several variables: greater number of individuals that bit
swabs, shorter latency to bite, greater rate of tongue-flicks, and greater tongue
flick attack score. The clearest differences were observed for tongue-flick
attack score, a composite variable that combines the effects of tongue-flicking
and biting. An insectivorous member of the same subfamily, Scincella lateralis,
shows strong tongue-flicking and biting response to chemical prey cues, but not
to plant chemicals. This suggests that response to plant chemicals by C. zebrata
may have evolved in tandem with the incorporation of plants into the diet and
that response to cricket chemicals has been retained, perhaps due to similarities
between plant and animal food. The findings support the hypothesis that dietary
shifts induce corresponding changes in chemosensory response, but provide only a
single independent contrast for a study of correlated evolution between plant
diet and chemosensory response to plants. J. Exp. Zool. 286:372-378, 2000.
PMID- 10684561
TI - Embryonic muscle development in rainbow trout (Oncorhynchus mykiss): a scanning
electron microscopy and immunohistological study.
AB - Embryonic muscle development was studied in rainbow trout (Oncorhynchus mykiss)
at low and high temperature using scanning electron microscopy (SEM) and
immunohistology. Somite development was described starting at stage 16 (Vernier
JM. 1969. Ann Embryol Morphogen 4:495-520) for both temperatures, with special
interest in their shape and size. Muscle differentiation, associated with somite
growth, is characterized by a larger increase in height compared to width and by
acquisition of a chevron shape. Thin structures such as striation, sarcomeres,
and myofibrils within muscle cells and myotubes were observed starting at the
eyed stage (stage 24). Immunohistological analyses showed appearance of embryonic
fast myosin at stage 20 in the deep part of the somite. The area where myosin was
expressed extended in the somite throughout embryonic development and the
presence of myosin was observed in the entire somite at hatching (stage 30). Slow
myosin was expressed in a monolayer of superficial cells at the eyed stage and
during the entire embryonic development. Then it was expressed in a few layers of
cells located in the red muscle area. These results suggest that muscle
differentiation, characterized by myosin expression, is engaged at stage 20.
Myogenesis starts in the deep part of the somite, near the notochord and
progresses laterally to cover the complete somite at hatching when the somite is
composed of muscle fibres exhibiting a high degree of maturity. No significant
difference was observed in terms of muscular development between low- and high
temperature conditions. J. Exp. Zool. 286:379-389, 2000.
PMID- 10684562
TI - Contrasting stress response of male arctic ground squirrels and red squirrels.
AB - A hormonal-challenge protocol was used to compare the stress response of males of
Arctic ground squirrels and red squirrels during the breeding season (May). These
squirrels live in the same boreal forest of the Yukon, but have very different
life histories and utilize the forest in markedly different ways. Red squirrels
had levels of total cortisol, maximum corticosteroid-binding capacity, and free
cortisol that were 5, 7, and 2 times, respectively, those of Arctic ground
squirrels. Red squirrels were resistant to suppression by an artificial
glucocorticoid, dexamethasone (DEX); Arctic ground squirrels were not. Cortisol
levels in red squirrels responded slowly but continuously to the ACTH injection;
Arctic ground squirrels responded rapidly and then stabilized. Testosterone
levels in red squirrels were extremely sensitive to the challenge, being
suppressed by both DEX and ACTH; levels in Arctic ground squirrels were resistant
to the challenge, being modestly suppressed by DEX and stimulated by ACTH. Energy
mobilization, as measured by glucose and free fatty acid responses, was not
affected. Red squirrels had four times the levels of white blood cells and higher
proportions of lymphocytes and lower proportions of eosinophils than Arctic
ground squirrels, indicating that the latter were in worse condition
immunologically. Our evidence suggests that the functions associated with the
hypothalamic-pituitary-adrenal axis are compromised in breeding male Arctic
ground squirrels, but not in red squirrels. We propose that in male red squirrels
this axis has evolved in the context of a stable social system based on long
lived animals with individual territories which are needed to deal with
unpredictable winter food supplies. In contrast, Arctic ground squirrels escape
the rigors of winter by hibernation and this hormonal axis has evolved in short
lived males in the context of intense intra-sexual competition in a social system
based on female kin groups and regular male dispersal to avoid inbreeding. J.
Exp. Zool. 286:390-404, 2000.
PMID- 10684563
TI - Changes along the pituitary-gonadal axis during maturation of the black carp,
Mylopharyngodon piceus.
AB - The black carp, Mylopharyngodon piceus, is a late-maturing cyprinid reaching
sexual maturity at the age of 6-7 years. The present work attempted to define
nonfunctional sites along the pituitary-gonadal axis in immature fish utilizing
in vivo and in vitro challenge experiments. Two- and 3-year old fish injected
with salmon gonadotropin-releasing hormone analog (sGnRHa; 10 microg/kg) and
metoclopramide (20 mg/kg) did not reveal any increase in circulating gonadotropin
(cGtH) or estradiol (E(2)) level. Furthermore, cGtH release from cultured
pituitary cells of fish at these ages did not increase in response to sGnRH (0.1
nM - 1 microM) but was augmented when exposed to TPA (12.5 nM). However, 4-year
old female fish did respond to the above treatments both in vivo and in vitro.
These results suggest the existence of nonfunctional site(s) proximal to the
activation of PKC in the immature black carp gonadotrophs, probably at the level
of GnRH receptors. These site(s) start to become functional in 4-year old fish.
Two- and 3-year old fish injected with common carp pituitary extract (CPE)
containing 350 microg cGtH/kg did not show any increase in circulating E(2). In
addition, the estrogen secretion from fragments of the rudimentary gonads did not
increase after exposure to CPE containing cGtH (0.5-4 microg/ml) but was elevated
dose-dependently by exposure to dbcAMP (0.3-3 mM). However, the ovaries of 4-year
old fish did respond to the gonadotropic stimulation, both in vivo and in vitro.
These results suggest the existence of other non-functional site(s) in the
immature black carp, proximal to the formation of cAMP in the gonads, probably at
the level of GtH receptors. These site(s) start to become functional in 4-year
old females. Another source of E(2) was discovered in the immature black carp:
namely, the fat pad adjacent to the gonads. In contrast to the visceral adipose
tissue, the fat pad secretes estrogen in response to cAMP elevation in 2- and 3
year old fish while in 4-year old fish it also responds to gonadotropic
stimulation. Due to its large mass and high steroidogenic potency, it is assumed
that the gonadal fat pad is involved in the process of puberty in the black carp.
J. Exp. Zool. 286:405-413, 2000.
PMID- 10684564
TI - Cilia-driven rotational behavior in gastropod (Physa elliptica) embryos induced
by serotonin and putative serotonin reuptake inhibitors (SSRIs).
AB - We characterized the serotonin (5-hydroxytryptamine; 5-HT) receptor mediating
cilia-driven rotational movement in embryos of the freshwater gastropod Physa
elliptica. In addition, putative serotonin reuptake inhibitors (SSRIs),
previously shown to induce other 5-HT-mediated processes in molluscs, were tested
for their ability to induce rotation. As in previous studies with other
freshwater gastropods, 5-HT induced a significant dose-dependent increase in
rotation from 10(-6) to 10(-4) M. The 5-HT(1A) agonist 8-OH-DPAT produced a
similar dose-dependent increase in rotation. However, the 5-HT(2) agonist alpha
CH3-serotonin evoked a significant rotational response only at the highest
concentration of 10(-4) M. The 5-HT(2) receptor antagonist mianserin not only
blocked 5-HT-induced rotation, it reduced rotation rate below that of baseline.
However, two other antagonists, cyproheptadine (5-HT(2)) and propranolol (5
HT(1)), caused similar responses that consisted of an initial rotational surge
followed by reduced rotation. Thus, these drugs appear to act as partial
agonists. The putative SSRI fluvoxamine exhibited a significant dose-dependent
increase in positive rotation as that seen with 5-HT. The SSRIs paroxetine and
fluoxetine both caused an increase in rotation at 10(-6) and 10(-5) M but reduced
rotation rate below that of baseline at 10(-4) M. These results agree with other
studies on aquatic molluscs, suggest a 5-HT receptor with a mixed 5-HT(1)/5-HT(2)
pharmacological profile and add to a now growing body of literature on the
pharmacology of molluscan 5-HT receptors. In addition, all the tested putative
SSRIs induced cilia-driven rotation in Physa embryos, indicating either the
presence of 5-HT reuptake transporters or that these compounds act as 5-HT
receptor ligands. J. Exp. Zool. 286:414-421, 2000.
PMID- 10684565
TI - Influence of incubation temperature on morphology, locomotor performance, and
early growth of hatchling wall lizards (Podarcis muralis).
AB - Eggs of wall lizards (Podarcis muralis) were incubated at three temperatures
approaching the upper limit of viability for embryonic development in this
species (26, 29, and 32 degrees C) to assess the influence of temperature on
various aspects of hatchling phenotype likely affecting fitness. The thermal
environment affected size and several morphometric characteristics of hatchling
lizards. Hatchlings from eggs incubated at 32 degrees C were smaller (snout-vent
length, SVL) than those from 26 and 29 degrees C and had smaller mass residuals
(from the regression on SVL) as well as shorter tail, head, and femur relative to
SVL. Variation in the level of fluctuating asymmetry in meristic and morphometric
traits associated with incubation temperatures was quite high but not clearly
consistent with the prediction that environmental stress associated with the
highest incubation temperatures might produce the highest level of asymmetry.
When tested for locomotor capacity in trials developed at body temperatures of 32
and 35 degrees C, hatchlings from the 32 degrees C incubation treatment exhibited
the worst performance in any aspect considered (burst speed, maximal length, and
number of stops in the complete run). Repeated measures ANCOVAs (with initial egg
mass as covariate) of snout-vent length and mass of lizards at days 0 and 20
revealed significant effects of incubation temperature only for mass, being again
the hatchlings from eggs incubated at 32 degrees C those exhibiting the smallest
final size. All together, our results evidenced a pervasive effect of thermal
regime during incubation (and hence of nest site selection) on hatchling
phenotypes. However, incubation temperature does not affect hatchling phenotypes
in a continuous way; for most of the analysed traits a critical threshold seems
to exist between 29 and 32 degrees C, so that hatchlings incubated at 32 degrees
C exhibited major detrimental effects. J. Exp. Zool. 286:422-433, 2000.
PMID- 10684566
TI - Novel aspects of the activities and subcellular distribution of enzymes of ketone
body metabolism in the liver and kidney of the goldfish, Carassius auratus.
AB - The metabolic organization of ketone body metabolism of liver and kidney of the
goldfish Carassius auratus was assessed by measuring maximal activities,
subcellular distribution, and stereoisomer preference of ketone body enzymes.
These determinations indicate that the organization of ketone body metabolism in
liver and kidney of goldfish differs from that of mammals in some respects. All
the enzymes of ketone body metabolism were present in liver and kidney of
goldfish, with the exception of hydroxymethylglutaryl-CoA (HMG-CoA) synthetase,
which was not detected in liver. Two forms of beta-hydroxybutyrate dehydrogenase
(betaHBDH) with different stereospecificity for beta-hydroxybutyrate (D- and L
beta-hydroxybutyrate) were detectable in liver and kidney. All of the ketone body
enzymes measured in liver were mainly in the mitochondrial fraction, with the
exception of D- and L-betaHBDH, which were cytosolic. In kidney, HMG-CoA
synthase, together with HMG-CoA lyase and acetoacetyl CoA thiolase (AcoAT), were
found mainly in the mitochondrial fraction. L-betaHBDH was mainly cytosolic in
kidney, but by contrast with liver, D-betaHBDH was mainly found in the
mitochondria, and SKT was distributed in both the mitochondrial and cytosolic
compartments. J. Exp. Zool. 286:434-439, 2000.
PMID- 10684567
TI - Disrupting the geranylgeranylation at the C-termini of the shrimp Ras by
depriving guanine nucleotide binding at the N-terminal.
AB - In order to assess the effects of guanine nucleotide binding on the
geranylgeranylation at the CAAX box of the shrimp Ras, we experimented with the
shrimp Penaeus japonicus Ras (S-Ras) which is geranylgeranylated at the C
termini, shares 85% homology with mammalian K(B)-Ras protein and demonstrates
identity in the guanine nucleotide binding domains (Huang C-F, Chuang N-N. 1999.
J Exp Zool 283:510-521). Several point mutations in the S-ras gene were generated
at codons 12 (G12V), 61 (Q61K), and 116 (N116I). The bacterially expressed mutant
S-Ras proteins, G12V and Q61K, were bound with GTP without hydrolysis. In
contrast, the mutant S-Ras N116I was defective in its ability to bind any guanine
nucleotides. Autoradiography studies showed that the purified shrimp protein
geranylgeranyltransferase I (Lin R-S, Chuang N-N. 1998. J Exp Zool 281:565-573)
was unable to catalyze the transfer of [(3)H]-geranylgeranylpyrophosphate to this
mutant N116I but very competently caused the geranylgeranylation of GTP-locked
mutants, G12V and Q61K. These results demonstrate that the geranylgeranylation at
the CAAX box of the shrimp Ras protein requires the proper binding of guanine
nucleotide at its N-terminal region. J. Exp. Zool. 286:441-449, 2000.
PMID- 10684568
TI - Lack of physiological plasticity in the early chicken embryo exposed to acute
hypoxia.
AB - By exposing chicken embryos to hypoxia (10%) acutely (2, 4, and 6 hr) during
early development (2, 3, and 4 days) we tested the hypothesis that hypoxia has an
impact on embryonic growth and impairs cardiac development at the time cardiac
morphogenesis is taking place. After the hypoxic perturbation, the embryos were
allowed to develop until day 9, when embryo mass, heart mass, and rate of oxygen
consumption were recorded. Four-day-old embryos exposed to 6 hr of hypoxia showed
an increased mortality (38.9% versus 18% for controls), indicating the immediate
effect of hypoxia on survivability. While only 8% of the controls displayed
morphological abnormalities, 3- and 4-day-old embryos exposed for 6 hr showed
more frequent developmental abnormalities (25% and 30% respectively). No
significant differences in embryo or heart mass were found except in 4-day-old
embryos exposed for 2 hr. Mass-specific oxygen consumption was not different
between controls and embryos exposed to hypoxia at 2 or 3 days of development,
but it was increased in 4-day-old embryos exposed for 4 hr (P < 0.05). These
results suggest that an acute hypoxic episode does not have an impact when
occurring very early in development (days 2 or 3). However, when the hypoxic
episode occurs on day 4, survivability is largely decreased. Considering the lack
of permanent effects on the surviving embryos, we suggest that the early embryo
resorts to a simple strategy of death or survival, and the individual capacity
for survival must be based on interindividual differences rather than the
existence of compensatory mechanisms. J. Exp. Zool. 286:450-456, 2000.
PMID- 10684569
TI - Participation of the GM1 ganglioside in the gastrulation of anuran amphibian Bufo
arenarum.
AB - In the present paper we established the ganglioside composition of the blastula
and gastrula stages of the anuran amphibian Bufo arenarum, two relevant stages
characterized by dynamic changes in morphology and cellular rearrangements.
Densitometric studies evidenced that GD1a and GT1b were the more abundant
gangliosides of the blastula embryos whereas GM1 and GM2 were the predominant
species in gastrula embryos. Analysis of ganglioside abundance indicates that the
"a" and "b" synthesis pathways perform similar biosynthetic activities in the
blastula stage, in contrast to the gastrula stage in which a marked predominance
of the "a" pathway occurred. The spatio-temporal expression of GM1 and of
polygangliotetraosyl ceramides (pGTC) was investigated by wholemount
immunocytochemistry using cholera toxin B subunit (CTB) and an affinity purified
human anti-GM1 antibody. The pGTC were detected as GM1 after treatment with
neuraminidase. Blastomeres from the inner surface of the blastocoelic roof (BCR)
of blastula embryos were GM1 and pGTC positive. At midgastrula stage, embryos
showed an increased labeling on the inner surface of BCR. To establish whether
the GM1 ganglioside was involved in the gastrulation processes, CTB, anti-GM1
antibodies and anti-GM1 Fab' fragments were microinjected into the blastocoel
cavity of blastula embryos. Treatment with the probes blocked gastrulation.
Scanning electron microscopy analysis of blocked embryos revealed that mesodermal
cell migration, radial interdigitation, and convergent extension movements were
affected. The blocking of gastrulation was correlated with the absence of
fibronectin and EP3/EP4 on the inner surface of blastocoelic roof of CTB- or anti
GM1 treated embryos. Results show that the GM1 ganglioside is differentially
expressed by embryonic cells and participates in the morphogenetic processes of
amphibian gastrulation. J. Exp. Zool. 286:457-472, 2000.
PMID- 10684570
TI - Corticotropin-releasing factor accelerates metamorphosis in Bufo arenarum: effect
on pituitary ACTH and TSH cells.
AB - The actions of several neuropeptides as hypothalamic mediators in the regulation
of Bufo arenarum metamorphosis were investigated. Prometamorphic larvae were
injected with 1.5 microg thyrotropin-releasing hormone (TRH), 2 microg ovine
corticotropin-releasing factor (oCRF), 2 microg mammalian gonadotropin-releasing
hormone (mGnRH), 2 microg human growth hormone-releasing hormone (hGHRH), or
Holtfreter solution (control group). Larvae received two injections with the same
dose: one at the beginning of the experiment and the other 7 days later. Several
morphologic parameters (total length, tail length, wet weight, hind limb length,
and metamorphic stages) were measured as indicators of growth and metamorphic
development. These measurements were taken in 20 larvae per treatment or control
group at the beginning of the experiment, at day 7 and at day 14 when the
experiment ended. We observed that only the administration of exogenous CRF
stimulated resorption of the tail and accelerated the rate of metamorphosis. In
the pituitary of CRF-treated larvae we observed that thyrotropin (TSH) and
adrenocorticotropic hormone (ACTH) producing cells showed a weaker
immunoreactivity, a decrease in cell number and a reduction of volume density
when compared with normal larvae. In conclusion, the results obtained indicate a
possible role for CRF in Bufo arenarum metamorphosis. CRF may regulate interrenal
and thyroid activity by acting directly upon TSH and ACTH cells. On the other
hand, TRH, GnRH and GHRH were inactive in stimulating growth or metamorphosis of
Bufo arenarum. J. Exp. Zool. 286:473-480, 2000.
PMID- 10684571
TI - Regulation of opioid peptides on the release of arginine vasotocin in the hen.
AB - Arginine vasotocin (AVT), an avian neurohypophysial hormone, is released during
osmotic stimulation and oviposition. In the present study, the role of opioid
peptides on AVT release was studied by examining the effects of an opioid agonist
and antagonist on osmotic- and oviposition-induced secretion of AVT. The
administration of hypertonic saline (1.5 M NaCl) induced an increase in the
plasma levels of AVT. The simultaneous administration of morphine, an opioid
receptor agonist, inhibited the osmotically induced increase in plasma levels of
AVT in a dose-dependent manner. On the other hand, the co-administration of
morphine with naloxone, an opioid receptor antagonist, attenuated the inhibitory
effect of morphine. Moreover, injection of naloxone alone enhanced the
osmotically induced increase in plasma levels of AVT. However, the administration
of morphine did not inhibit the oviposition-induced increase in plasma levels of
AVT. These results suggest that osmotic-induced release of AVT may be under
opioid regulation, while oviposition-induced release of AVT may be controlled by
a different mechanism. J. Exp. Zool. 286:481-486, 2000.
PMID- 10684572
TI - Interrelationship between food availability, fat body, and ovarian cycles in the
frog, Rana tigrina, with a discussion on the role of fat body in anuran
reproduction.
AB - Long-term experiments were conducted to study the progression of vitellogenic
cycles in Rana tigrina (an annual breeder) having different foraging backgrounds
and held under conditions of weekly or daily food supply and in presence or
absence of abdominal fat bodies. They were autopsied in June to assess fecundity.
In nature an adult R. tigrina produces on an average 4,000 eggs/100 g body mass
(b.m.) And spawns in June-July following monsoon rains. Weekly feeding from July
to next breeding season, June resulted in a significant decrease in both
fecundity (1700 eggs/100 g body b.m.) And mean size of eggs, compared to well-fed
or wild-caught frogs. The abdominal fat bodies were barely seen in frogs fed
weekly throughout, whereas in frogs fed weekly from July-December but daily from
January onwards, the fat bodies became noticeable (1% of b.m.) And number and
mean size of eggs increased significantly over those fed weekly throughout. Frogs
captured in January possessed enlarged fat bodies (5% of b.m.), depicting a good
foraging history. Maintenance of these frogs on a weekly feeding regimen led to
an exhaustion of fat stores. They produced less number of eggs (2, 000/100 g
b.m.) As compared to wild frogs but of normal size, whereas daily feeding slowed
down a depletion of fat body mass and also significantly increased fecundity
(3,000/100 g b.m.) Over the weekly fed individuals. Sham operation or fat body
ablation in October or February had no significant effect on total fecundity per
se (3,000-3,500 eggs/100 g b.m.) Compared to that of wild-caught frogs. However,
eggs were significantly smaller due to fat body ablation despite daily feeding.
The study shows that food abundance/fat bodies influence egg size and number in
R. tigrina and that a direct or indirect functional relationship exists between
fat body and ovarian cycles that are characteristically inverse to each other. J.
Exp. Zool. 286:487-493, 2000.
PMID- 10684573
TI - Visual and nutritional food cues fine-tune timing of reproduction in a
neotropical rainforest bird.
AB - Food may act as a proximate factor in the regulation of avian seasonal breeding.
Food cues could provide particularly important seasonal information to birds
living in variable tropical environments, but this has not yet been tested.
Spotted antbirds (Hylophylax n. naevioides) inhabiting a humid forest in central
Panama (9 degrees N) likely use changes in the tropical photoperiod to time
reproduction on a long-term, seasonal basis. We predicted that these
insectivorous birds also adjust reproduction to short-term cues such as food
availability because the onset of the rainy season and the resulting increase in
insect abundance varies considerably between years. To test this prediction,
prior to their breeding season (when they had half-maximal gonads), we either
exposed captive male spotted antbirds to an ad libitum standard diet only or
added live crickets to this diet. Males that received live crickets significantly
increased gonad sizes within 3 weeks over controls on the standard diet.
Moreover, in six additional experiments cricket availability always increased
song rate, usually within a few days. The stimulatory effect of live crickets on
song activity may function independent of nutritional aspects: Freshly killed
crickets, providing similar nutritional content as live crickets, did not
stimulate the birds' song activity. However, song activity increased to
intermediate levels when live crickets were shown under a clear plastic wrap,
i.e., when birds could see but not eat crickets. We hypothesize that the
opportunity to see and handle live insects stimulates song and reproductive
activity in these birds. Our data indicate for the first time that a tropical
rainforest bird can use food cues to evaluate the suitability of local
environmental conditions for breeding. J. Exp. Zool. 286:494-504, 2000.
PMID- 10684574
TI - Gonadal morphology of female diploid gynogenetic and triploid rainbow trout.
AB - Chromosome sets of fishes can be manipulated; this practice includes the
production of triploid and gynogenetic salmonids. Such chromosomal modifications
often result in abnormal ovarian development. In rainbow trout (RBT), triploid
females have string-like gonads lacking significant developing oocytes and are
suggested to be sterile due to the odd set of chromosomes disrupting oogenesis.
Aberrant ovarian development is reported to occur in about 30% of gynogenetic
females. It has been suggested that gynogenetic fish are more prone to expressing
developmental abnormalities due to either increased homozygosity or to incomplete
inactivation of the paternal chromatin. This investigation was done to compare
the ovarian morphology of female triploid and induced gynogenetic diploid RBT.
The objective was to determine whether the presence of supernumerary chromosomal
fragments, potentially generated during the process of sperm genome inactivation,
would result in abnormal gonadal development in gynogens comparable to that
observed in triploid females. Gonadal morphology was observed and karyotypical
analysis was completed on 21 gynogenetic fish. In 90% of the fish examined, the
presence of chromosomal fragments was positively correlated with irregular
ovarian development. The atypical gonadal morphology observed in the gynogens
resembled triploid RBT ovarian morphology. The results of this investigation
support the hypothesis that disruption of the normal diploid chromosomal
complement alters germ cell development in gynogenetic female RBT due to the
unbalanced nature of the genome. J. Exp. Zool. 286:505-512, 2000.
PMID- 10684576
TI - Fundamental cryobiology of rat immature and mature oocytes: hydraulic
conductivity in the presence of Me(2)SO, Me(2)SO permeability, and their
activation energies.
AB - The hydraulic conductivity in the presence of dimethyl sulfoxide Me(2)SO
(L(p)(Me(2)SO)), Me(2)SO (P(Me(2)SO)) permeability and reflection coefficient
(sigma) of immature (germinal vesicle; GV) and mature (metaphase II; MII) rat
oocytes were determined at various temperatures. A temperature controlled
micropipette perfusion technique was used to conduct experiments at five
different temperatures (30, 20, 10, 4, and -3 degrees C). Kedem and Katchalsky
membrane transport theory was used to describe the cell volume kinetics. The cell
volumetric changes of oocytes were calculated from the measurement of two oocyte
diameters, assuming a spherical shape. The activation energies (E(a)) of
L(p)(Me(2)SO) and P(Me(2)SO) were calculated using the Arrhenius equation.
Activation energies of L(p)(Me(2)SO) for GV and MII oocytes were 34.30 Kcal/mol
and 16.29 Kcal/mol, respectively; while the corresponding E(a)s of P(Me(2)SO)
were 19.87 Kcal/mol and 21.85 Kcal/mol, respectively. These permeability
parameters were then used to calculate cell water loss in rat oocytes during
cooling at subzero temperatures. Based on these values, the predicted optimal
cooling rate required to maintain extra- and intracellular water in near
equilibrium for rat GV stage oocytes was found to be between 0.05 degrees C/min
and 0. 025; while for rat MII oocytes, the corresponding cooling rate was 1
degrees C/min. These data suggest that standard cooling rates used for mouse
oocytes (e.g., 0.5-1 degrees C/min) can also be employed to cryopreserve rat MII
oocytes. However, the corresponding cooling rate required to avoid damage must be
significantly slower for the GV stage rat oocyte. J. Exp. Zool. 286:523-533,
2000.
PMID- 10684575
TI - 1H-NMR and (31)P-NMR analysis of energy metabolism of quiescent and motile turbot
(Psetta maxima) spermatozoa.
AB - 31P-NMR and (1)H-NMR were used to monitor changes of several compounds with high
energy bonds and metabolites prior to and after the initiation of motility of
turbot spermatozoa (Psetta maxima). The obtained (31)P-NMR spectra revealed the
presence of phosphomonoesters, phosphodiester, intracellular inorganic phosphate
(Pi), phosphocreatine (PCr), and free nucleotide triphosphate. Following the
activation of motility, the di- and tri-phosphate nucleotides, PCr,
phosphomonoesters levels dropped while Pi levels increased. A significant
increase of lactate was also seen at the end of the swimming phase. The
compositions of seminal fluid and urine were also determined. Lipoproteins,
formic acid, amino acid, and citric acid were detected in seminal fluid. Dimethyl
amine, trimethylamine, and trimethylamine oxyde were found in urine. These data
suggest that at least a part of the energy required during the swimming phase
results from anaerobic fermentation and oxidative phosphorylation. J. Exp. Zool.
286:513-522, 2000.
PMID- 10684577
TI - Effects of temperature on the deformity and sex differentiation of tilapia,
Oreochromis mossambicus.
AB - The effects of temperature on the deformity and sex differentiation of tilapia,
Oreochromis mossambicus, were investigated. Zero- (the hatching day), 5-, and 10
day-old tilapia were respectively divided into 4 groups that were reared at 20,
24, 28, and 32 degrees C for 5 days. Percentages of deformity were significantly
increased when tilapia were kept in the elevated temperatures (28 and 32 degrees
C) before 5 days old during this experiment, whereas the lower temperature (20
degrees C) had no effect on the development of morphology. On the other hand,
exposure to the lower temperature before 10 days old induced a high proportion of
females whereas a high proportion of males was induced by the elevated
temperature after 10 days old during this experiment. These results indicate that
morphological development is influenced by temperature, particularly by the
elevated temperature during a restricted developmental period. Both lower and
elevated temperatures induce the gonadal feminization and masculinization,
respectively, during its restricted developmental period. J. Exp. Zool. 286:534
537, 2000.
PMID- 10684578
TI - Lethal and non-lethal responses of spermatozoa from a wide variety of vertebrates
and invertebrates to lysenin, a protein from the coelomic fluid of the earthworm
Eisenia foetida.
AB - Lysenin, a novel protein that we isolated from the coelomic fluid of the
earthworm Eisenia foetida, binds specifically to sphingomyelin (SM) among various
phospholipids found in cell membranes, and causes cytolysis. The plasma membrane
of mammalian spermatozoa is known to contain SM at relatively high levels and we
therefore examined the effects of lysenin on the spermatozoa of various animals.
Lysenin had lethal effects on spermatozoa of 5 of 33 species of invertebrates
tested and on spermatozoa of 30 of 39 species of vertebrates. We postulated that
plasma membranes of the spermatozoa of most invertebrates might not contain SM
whereas those of most vertebrate species might contain SM. These possibilities
were supported by our failure to detect SM chemically in the testes of three
species of invertebrates, in none of which spermatozoa responded to lysenin. In
contrast, we detected SM in the testes of all 25 vertebrate species examined,
irrespective of a negative or positive response of spermatozoa to lysenin. None
of the six species of Protista examined was affected by lysenin. Our survey
suggests that, in general, the spermatozoa of animals can be grouped into two
categories, invertebrate and vertebrate, depending on the absence or presence of
SM in their plasma membrane. The incorporation of SM into spermatozoa seems first
to have occurred in protochordates during the course of evolution. Discussions
about the exceptional responses to lysenin observed in the spermatozoa of five
species of invertebrates and of nine species of vertebrates are made from
phylogenetic and reproductive viewpoints. J. Exp. Zool. 286:538-549, 2000.
PMID- 10684579
TI - Evolutionary developmental genetics of floral symmetry: the revealing power of
Linnaeus' monstrous flower.
AB - Actinomorphic flowers have several planes of reflectional symmetry while
zygomorphic flowers have just one. In a number of independent cases,
actinomorphic flowers have arisen from zygomorphic ones during evolution. A
famous example, studied by Linnaeus, is an actinomorphic variety of the common
toadflax Linaria vulgaris. It has been shown now that this mutant carries a
defect in LCYC, a homolog of the CYC gene, which controls zygomorphy in
Antirrhinum majus.((1)) Interestingly, the mutant phenotype is not due to changes
in the LCYC nucleotide sequence but rather to an extensive, heritable methylation
of the gene.((1)) A second gene controlling zygomorphy in snapdragon, DICH, has
recently also been shown to be a CYC homolog and both genes share significant
sequence similarity with TB1, one of the key genes of maize domestication. The
respective family of genes, probably encoding transcription factors, might thus
become both a useful instrument and a target of future plant evolutionary
developmental genetics.
PMID- 10684580
TI - AML1 haploinsufficiency, gene dosage, and the predisposition to acute leukemia.
AB - Hematopoiesis is the complex developmental process through which
undifferentiated, pluripotent, hematopoietic stem cells come to generate mature,
functional blood cells. This process is regulated in large part by specific
transcription factors that control expression of genes necessary for the
developmental sequence. Leukemias represent one form of disruption of this normal
developmental process, and studies over the past few years have shown that many
of the genes that underlay leukemogenesis are also essential for normal
hematopoiesis. In an interesting recent example, Song et al.((1)) demonstrate
that haploinsufficiency of the AML1 gene is the genetic basis of a form of
familial thrombocytopenia which predisposes the affected individuals to the
development of acute myeloid leukemia. Here we summarize Song's paper and current
information describing the interesting dosage effects of this gene and other
members of its gene family.
PMID- 10684581
TI - Cell fate choices in Drosophila tracheal morphogenesis.
AB - The Drosophila tracheal system is a branched tubular structure that supplies air
to target tissues. The elaborate tracheal morphology is shaped by two linked
inductive processes, one involving the choice of cell fates, and the other a
guided cell migration. We will describe the molecular basis for these processes,
and the allocation of cell fate decisions to four temporal hierarchies. First,
tracheal placodes are specified within the embryonic ectoderm. Subsequently,
branch fates are allocated within the tracheal placodes, prior to migration.
Localized presentation of the FGF ligand, Branchless, to tracheal cells that
express the FGF receptor, Breathless, guides migration. Once cell migration is
initiated, distinct cell fates are determined within each migrating branch.
Finally, inhibitory feedback mechanisms ensure the correct assignment of these
fates. Tracheal cell fate choices are determined by signaling cascades triggered
by signals emanating from the tracheal cells, as well as by ligands produced by
adjacent tissues.
PMID- 10684582
TI - Common structural features in gramicidin and other ion channels.
AB - This review compares and contrasts the structures of several different types of
ion channels with known three-dimensional structures, including gramicidin and
the family of peptaibol channels, as well as the Streptomyces lividans potassium
channel, to reveal common features in their structures that relate to their
functional roles in ion binding and transport across membranes. Specifically, the
locations of aromatic amino acids, the dimensions of the molecules, the
multimeric nature of the channels and the roles of hydrogen bonds in stabilising
such structures, the means by which the channels open and close, and the chemical
nature of the groups which make up the channel lumen are discussed. The emphasis
is on the commonality of features found in model channels, which may ultimately
be found in other biological channel structures.
PMID- 10684583
TI - Degradation of mRNA in bacteria: emergence of ubiquitous features.
AB - The amount of a messenger RNA available for protein synthesis depends on the
efficiency of its transcription and stability. The mechanisms of degradation that
determine the stability of mRNAs in bacteria have been investigated extensively
during the last decade and have begun to be better understood. Several endo- and
exoribonucleases involved in the mRNA metabolism have been characterized as well
as structural features of mRNA which account for its stability have been
determined. The most important recent developments have been the discovery that
the degradosome-a multiprotein complex containing an endoribonuclease (RNase E),
an exoribonuclease (polynucleotide phosphorylase), and a DEAD box helicase (RhlB)
has a central role in mRNA degradation and that oligo(A) tails synthesized by
poly(A) polymerase facilitate the degradation of mRNAs and RNA fragments.
Moreover, the phosphorylation status and the base pairing of 5' extremities,
together with 3' secondary structures of transcriptional terminators, contribute
to the stability of primary transcripts. Degradation of mRNAs can follow several
independent pathways. Interestingly, poly(A) tails and multienzyme complexes also
control the stability and the degradation of eukaryotic mRNAs. These discoveries
have led to the development of refined models of mRNA degradation.
PMID- 10684584
TI - Protein kinase C binding partners.
AB - Members of the protein kinase C family respond to second messengers and are
involved in controlling a broad array of cellular functions. The overlapping
specificity and promiscuity of these proteins has promoted the view that specific
binding proteins constrain individual family members to create the appropriate
specificity of action. It is speculated that such protein kinase C-regulator
protein interactions affect substrate availability as well as exposure to
allosteric activator(s) and that consequent interactions specify cellular
location and impose integration with other signaling systems. These predicted
features have been realized in the identification of many protein kinase C
interacting proteins and examples of these are discussed.
PMID- 10684585
TI - Phagosome dynamics and function.
AB - Phagocytosis of microorganisms and other particles is mediated most efficiently
by receptors such as Fc-receptors (FcR) and complement-receptors (C3R).
Interaction between these receptors and ligands on the particle results in signal
transduction events that lead to actin polymerisation and phagosome formation.
The phagosome then undergoes a maturation process whereby it transforms into a
phagolysosome. Phagosome maturation depends on interactions (fusion events) with
early and late endosomes as well as with lysosomes. The fusion processes are
regulated by small GTP-binding proteins and other proteins that are also involved
in fusion processes in the endocytic pathway. Although most phagocytosed
microorganisms are killed in the lysosome, some pathogens have developed survival
strategies and are able to live in the harsh conditions in the phagolysosome or
interfere with the maturation process and thereby evade destruction by acid
hydrolases.
PMID- 10684586
TI - Notch signaling in the nervous system. Pieces still missing from the puzzle.
AB - Notch has been known for many years as a receptor for inhibitory signals that
shapes the pattern of the nervous system during its development. Genes in the
Notch pathway function to prevent neural determination so that only a subset of
the available ectodermal cells become neural precursors. The localization of
Notch signaling is crucial for determining where neural precursor cells arise on
a cell-by-cell basis. The unresolved problem is that studies of the expression of
Notch protein and its ligands are inconsistent with the pattern of neurogenesis.
During neural cell fate specification, distributions of Notch protein and of its
ligand Delta appear uniform. Under the reigning paradigm, such widespread
expression should lead to N signal transduction in all cells and thereby prevent
any neural specification. Yet, contrary to this expectation, neural elements
still form, in characteristic patterns, hence, Notch signal transduction must
have been inactive in the precursor cells. The mechanism preventing Notch
signaling in certain cells must be posttranslational but it has not yet been
identified. This review will outline the experimental evidence supporting this
view of Notch signaling, and briefly evaluate some of the possible mechanisms
that have been suggested.
PMID- 10684587
TI - A new functional classification of tumor-suppressing genes and its therapeutic
implications.
AB - Cell fusion studies have demonstrated that malignancy can be suppressed by a
single dose of malignancy suppressor genes (MSGs), indicating that malignancy is
a recessive phenotype. Correspondingly, it is widely believed that mutational
inactivation of both alleles of tumor suppressor genes (TSGs), in familial and
sporadic tumors, is the formal proof of the recessive nature of malignancy.
Evidence presented here, however, shows that unlike MSGs, identified solely
through cell fusion studies with no gene of this class yet cloned, many well
known TSGs have gene dosage effects and inhibit cellular growth in vitro.
Moreover, homozygous inactivation of a growth-inhibitory TSG (GITSG) is not
directly correlated with malignancy. An alternative interpretation is provided
for the loss of wild-type alleles of these genes in the tumors. It is concluded
that the MSGs and the GITSGs do not belong to the same class of genes. The
functional classification of tumor-suppressing genes has important implications
for developing effective cancer therapies.
PMID- 10684588
TI - Bystander effects: a concept in need of clarification.
AB - An increasing body of evidence indicates that the response to genotoxic agents
such as radiation or drugs is a group phenomenon, rather than the summed response
of individual independent cells to injury. Thus, a complex contagion-like
response may spread beyond the initial impact of an agent to enlarge its effect.
This indirect effect, termed "Bystander Effect," is multifaceted and may play a
significant role in the therapy of tumors and in carcinogenesis. A better
understanding of this phenomenon is needed in order to modulate treatment
protocols to therapeutic advantage and to provide more rational guidelines for
the evaluation of environmental hazards.
PMID- 10684589
TI - The coral Acropora: what it can contribute to our knowledge of metazoan evolution
and the evolution of developmental processes.
AB - The diploblastic Cnidaria form one of the most ancient metazoan phyla and thus
provide a useful outgroup for comparative studies of the molecular control of
development in the more complex, and more often studied, triploblasts. Among
cnidarians, the reef building coral Acropora is a particularly appropriate choice
for study. Acropora belongs to the Anthozoa, which several lines of evidence now
indicate is the basal class within the phylum Cnidaria, and has the practical
advantages that its reproduction is predictable, external and accessible and that
the base content of its genome is not strongly biased. The Acropora system has
already provided insights into ancestral linkages of homeobox genes and the
evolution of the Pax genes, and has the potential to provide further new
perspectives on the age, role in development, and evolution of these and other
gene families.
PMID- 10684590
TI - What transgenic mice tell us about neurodegenerative disease.
AB - The recent broad advance in our understanding of human neurodegenerative diseases
is based on the application of a new molecular approach. Through linkage
analysis, the genes responsible for Huntington's disease, the spinocerebellar
ataxias, and familial forms of Alzheimer's disease and amyotrophic lateral
sclerosis (ALS) have been identified and cloned. The characterization of
pathogenic mutations in such genes allows the creation of informative transgenic
mouse models as, without exception, the genetic forms of adult neurodegenerative
disease are due to toxicity of the mutant protein. Transgenic models provide
insight into the oxidative mechanisms in ALS pathogenesis, the pathogenicity of
expanded polyglutamine tracts in CAG triplet repeat disorders, and
amyloidogenesis in Alzheimer's disease. Although such models have their
limitations, they currently provide the best entry point for the study of human
neurodegenerative diseases.
PMID- 10684591
TI - Drosophila: flying high in Zurich.
PMID- 10684592
TI - Popper.
PMID- 10684593
TI - The utility of Popper's philosophy in biology.
PMID- 10684594
TI - Don't belittle Popper. Refutation cannot be refuted in biology, either.
PMID- 10684595
TI - Kinetic studies of the mechanism of carbon-hydrogen bond breakage by the
heterotetrameric sarcosine oxidase of Arthrobacter sp. 1-IN.
AB - The reaction of heterotetrameric sarcosine oxidase (TSOX) of Arthrobactor sp. 1
IN has been studied by stopped-flow spectroscopy, with particular emphasis on the
reduction of the enzyme by sarcosine. Expression of the cloned gene encoding TSOX
in Escherichia coli enables the production of TSOX on a scale suitable for
stopped-flow studies. Treatment of the enzyme with sulfite provides the means for
selective formation of a flavin-sulfite adduct with the covalent 8alpha-(N(3)
histidyl)-FMN. Formation of the sulfite-flavin adduct suppresses internal
electron transfer between the noncovalent FAD (site of sarcosine oxidation) and
the covalent FMN (site of enzyme oxidation) and thus enables detailed
characterization of the kinetics of FAD reduction by sarcosine using stopped-flow
methods. The rate of FAD reduction displays a simple hyperbolic dependence on
sarcosine concentration. Studies in the pH range 6.5-10 indicate there are no
kinetically influential ionizations in the enzyme-substrate complex. A plot of
the limiting rate of flavin reduction/the enzyme-substrate dissociation constant
(k(lim)/K(d)) versus pH is bell-shaped and characterized by two macroscopic pK(a)
values of 7.4 +/- 0.1 and 10.4 +/- 0.2: potential candidates for the two
ionizable groups are discussed with reference to the structure of monomeric
sarcosine oxidase (MSOX). The kinetic data are discussed with reference to
potential mechanisms for the oxidation of amine molecules by flavoenzymes.
Additionally, kinetic isotope effect studies of the rate of C-H bond breakage
suggest that a ground-state quantum tunneling mechanism for H-transfer,
facilitated by the low-frequency thermal motions of the protein molecule,
accounts for C-H bond cleavage by TSOX. TSOX thus provides another example of C-H
bond breakage by ground-state quantum tunneling, driven by protein dynamics
[vibrationally enhanced ground-state quantum tunneling (VEGST)], for the
oxidation of amines by enzymes.
PMID- 10684596
TI - Reactions of Pseudomonas 7A glutaminase-asparaginase with diazo analogues of
glutamine and asparagine result in unexpected covalent inhibitions and suggests
an unusual catalytic triad Thr-Tyr-Glu.
AB - Pseudomonas 7A glutaminase-asparaginase (PGA) catalyzes the hydrolysis of D and L
isomers of glutamine and asparagine. Crystals of PGA were reacted with diazo
analogues of glutamine (6-diazo-5-oxo-L-norleucine, DON) and asparagine (5-diazo
4-oxo-L-norvaline, DONV), which are known inhibitors of the enzyme. The
derivatized crystals remained isomorphous to native PGA crystals. Their
structures were refined to crystallographic R = 0.20 and R(free) = 0.24 for PGA
DON and R = 0.19 and R = 0.23 for PGA-DONV. Difference Fourier electron density
maps clearly showed that both DON and DONV inactivate PGA through covalent
inhibition. Continuous electron density connecting the inhibitor to both Thr20
and Tyr34 of the flexible loop was observed providing strong evidence that Thr20
is the primary catalytic nucleophile and that Tyr34 plays an important role in
catalysis as well. The unexpected covalent binding observed in the PGA-DON and
PGA-DONV complexes shows that a secondary reaction involving the formation of a
Tyr34-inhibitor bond takes place with concomitant inactivation of PGA. The
predicted covalent linkage is not seen, however, suggesting an alternative method
of inhibition not yet seen for these diazo analogues. These surprising results
give insight as to the role of the flexible loop Thr and Tyr in the catalytic
mechanism.
PMID- 10684597
TI - Mutations at the histidine 249 ligand profoundly alter the spectral and iron
binding properties of human serum transferrin N-lobe.
AB - Human serum transferrin is an iron-binding and -transport protein which carries
iron from the blood stream into various cells. Iron is held in two deep clefts
located in the N- and C-lobes by coordinating to four amino acid ligands, Asp 63,
Tyr 95, Tyr 188, and His 249 (N-lobe numbering), and to two oxygens from
carbonate. We have previously reported the effect on the iron-binding properties
of the N-lobe following mutation of the ligands Asp 63, Tyr 95, and Tyr 188. Here
we report the profound functional changes which result from mutating His 249 to
Ala, Glu, or Gln. The results are consistent with studies done in lactoferrin
which showed that the histidine ligand is critical for the stability of the iron
binding site [H. Nicholson, B. F. Anderson, T. Bland, S. C. Shewry, J. W.
Tweedie, and E. N. Baker (1997) Biochemistry 36, 341-346]. In the mutant H249A,
the histidine ligand is disabled, resulting in a dramatic reduction in the
kinetic stability of the protein toward loss of iron. The H249E mutant releases
iron three times faster than wild-type protein but shows significant changes in
both EPR spectra and the binding of anion. This appears to be the net effect of
the metal ligand substitution from a neutral histidine residue to a negative
glutamate residue and the disruption of the "dilysine trigger" [MacGillivray, R.
T. A., Bewley, M. C., Smith, C. A., He, Q.-Y., Mason, A. B., Woodworth, R. C.,
and Baker, E. N. (2000) Biochemistry 39, 1211-1216]. In the H249Q mutant, Gln 249
appears not to directly contact the iron, given the similarity in the
spectroscopic properties and the lability of iron release of this mutant to the
H249A mutant. Further evidence for this idea is provided by the preference of
both the H249A and H249Q mutants for nitrilotriacetate rather than carbonate in
binding iron, probably because NTA is able to provide a third ligation partner.
An intermediate species has been identified during the kinetic interconversion
between the NTA and carbonate complexes of the H249A mutant. Thus, mutation of
the His 249 residue does not abolish iron binding to the transferrin N-lobe but
leads to the appearance of novel iron-binding sites of varying structure and
stability.
PMID- 10684598
TI - Mutation of the iron ligand His 249 to Glu in the N-lobe of human transferrin
abolishes the dilysine "trigger" but does not significantly affect iron release.
AB - Serum transferrin is the major iron transport protein in humans. Its function
depends on its ability to bind iron with very high affinity, yet to release this
bound iron at the lower intracellular pH. Possible explanations for the release
of iron from transferrin at low pH include protonation of a histidine ligand and
the existence of a pH-sensitive "trigger" involving a hydrogen-bonded pair of
lysines in the N-lobe of transferrin. We have determined the crystal structure of
the His249Glu mutant of the N-lobe half-molecule of human transferrin and
compared its iron-binding properties with those of the wild-type protein and
other mutants. The crystal structure, determined at 2.4 A resolution (R-factor
19.8%, R(free) 29.4%), shows that Glu 249 is directly bound to iron, in place of
the His ligand, and that a local movement of Lys 296 has broken the dilysine
interaction. Despite the loss of this potentially pH-sensitive interaction, the
H249E mutant is only slightly more acid-stable than wild-type and releases iron
slightly faster. We conclude that the loss of the dilysine interaction does make
the protein more acid stable but that this is counterbalanced by the replacement
of a neutral ligand (His) by a negatively charged one (Glu), thus disrupting the
electroneutrality of the binding site.
PMID- 10684599
TI - Camelid heavy-chain variable domains provide efficient combining sites to
haptens.
AB - Camelids can produce antibodies devoid of light chains and CH1 domains (Hamers
Casterman, C. et al. (1993) Nature 363, 446-448). Camelid heavy-chain variable
domains (VHH) have high affinities for protein antigens and the structures of two
of these complexes have been determined (Desmyter, A. et al. (1996) Nature Struc.
Biol. 3, 803-811; Decanniere, K. et al. (1999) Structure 7, 361-370). However,
the small size of these VHHs and their monomeric nature bring into question their
capacity to bind haptens. Here, we have successfully raised llama antibodies
against the hapten azo-dye Reactive Red (RR6) and determined the crystal
structure of the complex between a dimer of this hapten and a VHH fragment. The
surface of interaction between the VHH and the dimeric hapten is large, with an
area of ca. 300 A(2); this correlates well with the low-dissociation constant of
22 nM measured for the monomer. The VHH fragment provides an efficient combining
site to the RR6, using its three CDR loops. In particular, CDR1 provides a strong
interaction to the hapten through two histidine residues bound to its copper
atoms. VHH fragments might, therefore, prove to be valuable tools for selecting,
removing, or capturing haptens. They are likely to play a role in biotechnology
extending beyond protein recognition alone.
PMID- 10684600
TI - Mutagenesis of E477 or K505 in the B' domain of human topoisomerase II beta
increases the requirement for magnesium ions during strand passage.
AB - A type II topoisomerase is essential for decatenating DNA replication products,
and it accomplishes this task by passing one DNA duplex through a transient break
in a second duplex. The B' domain of topoisomerase II contains three highly
conserved motifs, EGDSA, PL(R/K)GK(I/L/M)LNVR, and IMTD(Q/A)DXD. We have
investigated these motifs in topoisomerase II beta by mutagenesis, and report
that they play a critical role in establishing the DNA cleavage-religation
equilibrium. In addition, the mutations E477Q (EGDSA) and K505E (PLRGKILNVR)
increase the optimal magnesium ion concentration for strand passage, without
affecting the Mg(2+) dependence of ATP hydrolysis. It is likely that the binding
affinity of the magnesium ion(s) specifically required for DNA cleavage has been
reduced by these mutations. The crystal structure of yeast topo II indicates that
residues E477 and K505 may help to position the three aspartate residues of the
IMTD(Q/A)DXD motif for magnesium ion coordination, and we propose two possible
locations for the magnesium ion binding site(s). These observations are
consistent with a previous model in which the B' domain is positioned such that
these acidic residues lie next to the active site tyrosine residue. A magnesium
ion bound by these aspartate residues could therefore mediate the DNA cleavage
religation reaction.
PMID- 10684601
TI - Structural and mechanistic basis for the activation of a low-molecular weight
protein tyrosine phosphatase by adenine.
AB - Although the activation of low-molecular weight protein tyrosine phosphatases by
certain purines and purine derivatives was first described three decades ago, the
mechanism of this rate enhancement was unknown. As an example, adenine activates
the yeast low-molecular weight protein tyrosine phosphatase LTP1 more than 30
fold. To examine the structural and mechanistic basis of this phenomenon, we have
determined the crystal structure of yeast LTP1 complexed with adenine. In the
crystal structure, an adenine molecule is found bound in the active site cavity,
sandwiched between the side chains of two large hydrophobic residues at the
active site. Hydrogen bonding to the side chains of other active site residues,
as well as some water-mediated hydrogen bonds, also helps to fix the position of
the bound adenine molecule. An ordered water was found in proximity to the bound
phosphate ion present in the active site, held by hydrogen bonding to N3 of
adenine and Odelta1 of Asp-132. On the basis of the crystal structure, we propose
that this water molecule is the nucleophile that participates in the
dephosphorylation of the phosphoenzyme intermediate. Solvent isotope effect
studies show that there is no rate-determining transfer of a solvent-derived
proton in the transition state for the dephosphorylation of the phosphoenzyme
intermediate. Such an absence of general base catalysis of water attack is
consistent with the stability of the leaving group, namely, the thiolate anion of
Cys-13. Consequently, adenine activates the enzyme by binding and orienting a
water nucleophile in proximity to the phosphoryl group of the phosphoenzyme
intermediate, thus increasing the rate of the dephosphorylation step, a step that
is normally the rate-limiting step of this enzymatic reaction.
PMID- 10684602
TI - Residues in Cdc42 that specify binding to individual CRIB effector proteins.
AB - Cdc42 is a member of the Rho family of small G proteins. Signal transduction
events emanating from Cdc42 lead to cytoskeletal rearrangements, cell
proliferation, and cell differentiation. Many effector proteins have been
identified for Cdc42; however, it is not clear how certain effectors specifically
recognize and bind to Cdc42, as opposed to Rac or Rho, or in many cases, which
effector controls what cellular events. Mutations were introduced into Cdc42 at
residues: Met1, Val8, Phe28, Tyr32, Val33, Thr35, Val36, Phe37, Asp38, Tyr40,
Val42, Met45, Ile46, Glu127, Ala130, Asn132, Gln134, Lys135, and Leu174.
Measurements were made of their equilibrium binding constants to the Cdc42
binding domains of the CRIB effectors ACK, PAK, and WASP and to the GTPase
activating protein Rho GAP. Generally, mutations in the effector loop have an
equally deleterious effect on binding to all CRIB proteins tested, though the
F37A mutation resulted in significant selectivity. Residues outside the effector
loop were found to be important for binding of Cdc42 to CRIB containing proteins
and also to contribute to selectivity. Mutations such as V42A and L174A resulted
in large, selective changes in binding to specific CRIB effectors. Neither
mutation resulted in alteration in PAK binding, whereas both severely disrupt
binding to ACK and only L174A disrupted binding to WASP. These mutations are
interpreted using the structures of the Cdc42/ACK and Cdc42/WASP complexes to
give insight into how effectors can specifically recognize Cdc42. Those mutations
in Cdc42 that inhibit certain interactions, while retaining others, should aid
investigations of the role of specific effectors in Cdc42 signaling in vivo.
PMID- 10684603
TI - Contribution of surface salt bridges to protein stability.
AB - The role of surface salt bridges in protein stabilization has been a source of
controversy. Here we present the NMR structure of a hyperthermophilic rubredoxin
variant (PFRD-XC4) and the thermodynamic analysis of two surface salt bridges by
double mutant cycles. This analysis shows that the surface side chain to side
chain salt bridge between Lys 6 and Glu 49 does not stabilize PFRD-XC4. The main
chain to side chain salt bridge between the N-terminus and Glu 14 was, however,
found to stabilize PFRD-XC4 by 1. 5 kcal mol(-)(1). The entropic cost of making a
surface salt bridge involving the protein's backbone is reduced, since the
backbone has already been immobilized upon protein folding.
PMID- 10684604
TI - Actinonin, a naturally occurring antibacterial agent, is a potent deformylase
inhibitor.
AB - Peptide deformylase (PDF) is essential in prokaryotes and absent in mammalian
cells, thus making it an attractive target for the discovery of novel
antibiotics. We have identified actinonin, a naturally occurring antibacterial
agent, as a potent PDF inhibitor. The dissociation constant for this compound was
0.3 x 10(-)(9) M against Ni-PDF from Escherichia coli; the PDF from
Staphylococcus aureus gave a similar value. Microbiological evaluation revealed
that actinonin is a bacteriostatic agent with activity against Gram-positive and
fastidious Gram-negative microorganisms. The PDF gene, def, was placed under
control of P(BAD) in E. coli tolC, permitting regulation of PDF expression levels
in the cell by varying the external arabinose concentration. The susceptibility
of this strain to actinonin increases with decreased levels of PDF expression,
indicating that actinonin inhibits bacterial growth by targeting this enzyme.
Actinonin provides an excellent starting point from which to derive a more potent
PDF inhibitor that has a broader spectrum of antibacterial activity.
PMID- 10684605
TI - Structure of a NifS homologue: X-ray structure analysis of CsdB, an Escherichia
coli counterpart of mammalian selenocysteine lyase.
AB - Escherichia coli CsdB, a NifS homologue with a high specificity for L
selenocysteine, is a pyridoxal 5'-phosphate (PLP)-dependent dimeric enzyme that
belongs to aminotransferases class V in fold-type I of PLP enzymes and catalyzes
the decomposition of L-selenocysteine into selenium and L-alanine. The crystal
structure of the enzyme has been determined by the X-ray crystallographic method
of multiple isomorphous replacement and refined to an R-factor of 18.7% at 2.8 A
resolution. The subunit structure consists of three parts: a large domain of an
alpha/beta-fold containing a seven-stranded beta-sheet flanked by seven helices,
a small domain containing a four-stranded antiparallel beta-sheet flanked by
three alpha-helices, and an N-terminal segment containing two alpha-helices. The
overall fold of the subunit is similar to those of the enzymes belonging to the
fold-type I family represented by aspartate aminotransferase. However, CsdB has
several structural features that are not observed in other families of the
enzymes. A remarkable feature is that an alpha-helix in the lobe extending from
the small domain to the large domain in one subunit of the dimer interacts with a
beta-hairpin loop protruding from the large domain of the other subunit. The
extended lobe and the protruded beta-hairpin loop form one side of a limb of each
active site in the enzyme. The most striking structural feature of CsdB lies in
the location of a putative catalytic residue; the side chain of Cys364 on the
extended lobe of one subunit is close enough to interact with the gamma-atom of a
modeled substrate in the active site of the subunit. Moreover, His55 from the
other subunit is positioned so that it interacts with the gamma- or beta-atom of
the substrate and may be involved in the catalytic reaction. This is the first
report on three-dimensional structures of NifS homologues.
PMID- 10684606
TI - Channeling of carbon monoxide during anaerobic carbon dioxide fixation.
AB - Carbon monoxide is an intermediate in carbon dioxide fixation by diverse microbes
that inhabit anaerobic environments including the human colon. These organisms
fix CO(2) by the Wood-Ljungdahl pathway of acetyl-CoA biosynthesis. The
bifunctional CO dehydrogenase/acetyl-CoA synthase (CODH/ACS) catalyzes several
key steps in this pathway. CO(2) is reduced to CO at a nickel iron-sulfur cluster
called cluster C located in the CODH subunit. Then, CO is condensed with a methyl
group and coenzyme A at cluster A, another nickel iron-sulfur cluster in the ACS
subunit. Spectroscopic studies indicate that clusters A and C are at least 10-15
A apart. To gain a better understanding of how CO production and utilization are
coordinated, we have studied an isotopic exchange reaction between labeled CO(2)
and the carbonyl group of acetyl-CoA with the CODH/ACS from Clostridium
thermoaceticum. When solution CO is provided at saturating levels, only CO(2)
derived CO is incorporated into the carbonyl group of acetyl-CoA. Furthermore,
when high levels of hemoglobin or myoglobin are added to remove CO from solution,
there is only partial inhibition of the incorporation of CO(2)-derived CO into
acetyl-CoA. These results provide strong evidence for the existence of a CO
channel between cluster C in the CODH subunit and cluster A in the ACS subunit.
The existence of such a channel would tightly couple CO production and
utilization and help explain why high levels of this toxic gas do not escape into
the environment. Instead, microbes sequester this energy-rich carbon source for
metabolic reactions.
PMID- 10684607
TI - Probes of a role for remote binding interactions on hydrogen tunneling in the
horse liver alcohol dehydrogenase reaction.
AB - A tunneling contribution to hydride transfer has been demonstrated previously in
the oxidation of benzyl alcohol catalyzed by an active-site mutant (F93W) of
horse liver alcohol dehydrogenase (LADH) [Bahnson, B. J., et al. (1993)
Biochemistry 32, 5503-5507]. Mutation of a residue that lies directly behind the
nicotinamide ring of the bound cofactor has further shown that side-chain bulk
can contribute to catalytic efficiency and tunneling in a correlated fashion
[Bahnson, B. J., et al. (1997) Proc. Natl. Acad. Sci. U.S.A. 94, 12797-12802].
Second site mutations of F93W have now been made at positions more remote from
the active site. In particular, we have focused on an isoleucine residue that
interacts with the adenine moiety of the NAD(+) cofactor, 20 A from the
nicotinamide ring. Replacement of this remote residue with glycine (F93W:I224G),
alanine (F93W:I224A), valine (F93W:I224V), and leucine (F93W:I224L) is concluded
to destabilize the binding of NAD(+). All double mutants exhibited a K(M) for
NAD(+) that is 2-25 times higher than that for the F93W enzyme. However, neither
the catalytic efficiency for turnover of benzyl alcohol [k(cat)/K(M(benzyl
alcohol))] nor the relationship between the secondary k(H)/k(T) and k(D)/k(T)
isotope effects for benzyl alcohol oxidation was significantly affected. The lack
of differences observed in the isotope effects indicates that these mutations
have little effect on the extent of hydrogen tunneling in the reaction. The
complete removal of the side chain at position 224 in the F93W:I224G enzyme
resulted in a less than 5% decrease in the ratio of the secondary isotope
effects, maintaining the ratio above the semiclassical limit for the indication
of tunneling in the reaction. By contrast, K(i) for NAD(+) increased 60-fold for
this mutant. The results obtained with F93W:I224G are consistent with remote
interactions that affect the association and binding of cofactor in a reactive
conformation. However, once this conformation is achieved, hydride transfer and
its tunneling component proceed as with the single F93W mutant enzyme,
uninfluenced by the remote mutation. Replacement of other side chains, with alpha
carbon positions from about 8 to over 20 A from the C4 position of the
nicotinamide ring, demonstrated a similar insensitivity of k(cat)/K(M(benzyl
alcohol)) to protein modification. Comparison to earlier studies with active-site
mutants of LADH implicates a role for proximal, but not distal, side chains in
the modulation of hydrogen tunneling for this enzyme.
PMID- 10684608
TI - Mechanistic analysis of the argE-encoded N-acetylornithine deacetylase.
AB - The E. coli argE-encoded N-acetyl-L-ornithine deacetylase has been cloned,
expressed, and purified in high yield. The substrate specificity of the enzyme is
relatively broad, with a number of alpha-N-acyl-L-amino acids exhibiting
activity, including both alpha-N-acetyl- and alpha-N-formylmethionine that
exhibit higher activity than alpha-N-acetyl-L-ornithine. Sequence homolgy
suggests that the enzyme is a member of the metal-dependent aminoacylase family,
and the purified enzyme contains a single atom of zinc per monomer. The activity
of this enzyme can be increased greater than 2-fold by the addition of zinc, or 8
fold by the addition of cobalt. This suggests that the enzyme can accommodate two
metal ions at the active site. The pH dependence of the kinetic parameters has
been determined and revealed the presence of two enzymic groups, one functioning
as a general base and one functioning as a general acid. Solvent kinetic isotope
effects on the hydrolysis of N-acetylornithine have been determined, and a linear
proton inventory suggests that a single proton transfer occurs in a partially
rate-limiting step. A chemical mechanism is proposed and compared with other
mechanisms determined for other members of the aminoacylase family.
PMID- 10684609
TI - Characterization of five catalytic activities associated with the NADPH:2
ketopropyl-coenzyme M [2-(2-ketopropylthio)ethanesulfonate]
oxidoreductase/carboxylase of the Xanthobacter strain Py2 epoxide carboxylase
system.
AB - The bacterial metabolism of propylene proceeds by epoxidation to epoxypropane
followed by carboxylation to acetoacetate. Epoxypropane carboxylation is a
minimetabolic pathway that requires four enzymes, NADPH, NAD(+), and coenzyme M
(CoM; 2-mercaptoethanesulfonate) and occurs with the overall reaction
stoichiometry: epoxypropane + CO(2) + NADPH + NAD(+) + CoM --> acetoacetate +
H(+) + NADP(+) + NADH + CoM. The terminal enzyme of the pathway is NADPH:2
ketopropyl-CoM [2-(2-ketopropylthio)ethanesulfonate] oxidoreductase/carboxylase
(2-KPCC), an FAD-containing enzyme that is a member of the NADPH:disulfide
oxidoreductase family of enzymes and that catalyzes the reductive cleavage and
carboxylation of 2-ketopropyl-CoM to form acetoacetate and CoM according to the
reaction: 2-ketopropyl-CoM + NADPH + CO(2) --> acetoacetate + NADP(+) + CoM. In
the present work, 2-KPCC has been characterized with respect to the above
reaction and four newly discovered partial reactions of relevance to the
catalytic mechanism, and each of which requires the formation of a stabilized
enolacetone intermediate. These four reactions are (1) NADPH-dependent cleavage
and protonation of 2-ketopropyl-CoM to form NADP(+), CoM, and acetone, a reaction
analogous to the physiological reaction but in which H(+) is the electrophile;
(2) NADP(+)-dependent synthesis of 2-ketopropyl-CoM from CoM and acetoacetate,
the reverse of the physiologically important forward reaction; (3) acetoacetate
decarboxylation to form acetone and CO(2); and (4) acetoacetate/(14)CO(2)
exchange to form (14)C(1)-acetoacetate and CO(2). Acetoacetate decarboxylation
and (14)CO(2) exchange occurred independent of NADP(H) and CoM, demonstrating
that these substrates are not central to the mechanism of enolate generation and
stabilization. 2-KPCC did not uncouple NADPH oxidation or NADP(+) reduction from
the reactions involving cleavage or formation of 2-ketopropyl-CoM. N
Ethylmaleimide inactivated the reactions forming/using 2-ketopropyl-CoM but did
not inactivate acetoacetate decarboxylation or (14)CO(2) exchange reactions. The
biochemical characterization of 2-KPCC and the associated five catalytic
activities has allowed the formulation of an unprecedented mechanism of substrate
activation and carboxylation that involves NADPH oxidation, a redox active
disulfide, thiol-mediated reductive cleavage of a C-S thioether bond, the
formation of a CoM:cysteine mixed disulfide, and enolacetone stabilization.
PMID- 10684610
TI - Stepwise modulation of ATPase activity, nucleotide trapping, and sliding motility
of myosin S1 by modification of the thiol region with residues of increasing
size.
AB - Rabbit muscle myosin S1 was modified either at SH1 alone or at both SH1 and SH2,
using a series of alkylthiolating reagents of increasing size, designed for
correlating gradually changing structural disturbances in the thiol region with
functional impairments in the myosin head. The reagents were of the type
H(CH(2))(n)()-S-NTB, (NTB = 2-nitro-5-thiobenzoate) (n = 1, 2, 5, 8, 9, 10, 11,
and 12). Modification of only SH1 led to the expected activation of the Ca(2+)
ATPase, but only with small reagents, while reagents with n > or = 10 caused
inhibition of the Ca(2+)-ATPase. Modification of both SH1 and SH2 showed the
expected inhibition of Ca(2+)-ATPase but likewise allowed considerable residual
Ca(2+)-ATPase activity if the residues were small. Trapping of the nucleotide,
known to occur with cross-linking reagents, was seen also with monovalent
reagents, provided their length exceeded n = 9 or 10. All S1 derivatives prepared
in this study possessed an affinity for actin comparable to native S1 but lacked
sliding motility in in vitro motility assays. The biochemical data of this study
can be related to existing models of myosin S1 and recent structural data
[Houdusse, A., Kalabokis, V. N., Himmel, D., Szent-Gyorgyi, A. G., and Cohen, C.
(1999) Cell 97, 459-470] by making the assumptions that modification at SH1
prevents the formation of the SH1 helix mandatory for the transmission of
conformational energy and that mobility of the thiol region is a prerequisite for
ATPase activity. Immobilization of the thiol region by residues of increasing
size apparently leads to lower enzyme activity and, finally, to inhibition of
nucleotide exchange.
PMID- 10684611
TI - Novel interaction of the voltage-dependent sodium channel (VDSC) with calmodulin:
does VDSC acquire calmodulin-mediated Ca2+-sensitivity?
AB - The voltage-dependent sodium channel (VDSC) interacts with intracellular
molecules to modulate channel properties and localizations in neuronal cells. To
study protein interactions, we applied yeast two-hybrid screening to the
cytoplasmic C-terminal domain of the main pore-forming alpha-subunit. We found a
novel interaction between the C-terminal domain and calmodulin (CaM). By two
hybrid interaction assays, we specified the interaction site of VDSC in a C
terminal region, which is composed of 38 amino acid residues and contains both IQ
like and Baa motifs. Using a fusion protein of the C-terminal domain, we showed
that interaction with CaM occurred in the presence and absence of Ca(2+). Two
synthetic peptides, each covering the IQ-like (NaIQ) or the Baa motifs (NaBaa),
were used to examine the binding property by a gel mobility shift assay. Although
the NaIQ and NaBaa sequences are overlapped, NaBaa binds only to Ca(2+)-bound
Ca(2+)CaM, whereas NaIQ binds to both Ca(2+)CaM and Ca(2+)-free apoCaM.
Fluorescence spectroscopy of dansylated CaM showed Ca(2+)-dependent spectral
changes not only for NaBaa.CaM but also for NaIQ.CaM. The results, taken together
with other results, indicate that whereas the NaBaa.CaM complex is formed in a
Ca(2+)-dependent manner, the NaIQ.CaM complex has two conformational states,
distinct with respect to the peptide binding site and the CaM conformation,
depending on the Ca(2+) concentration. These observations suggest the possibility
that VDSC is functionally modulated through the direct CaM interaction and the
Ca(2+)-dependent conformational transition of the complex.
PMID- 10684612
TI - A230Y mutation of actin on subdomain 4 is sufficient for higher calcium
activation of actin-activated myosin adenosinetriphosphatase in the presence of
tropomyosin-troponin.
AB - To probe the mechanism by which Ca(2+) activates muscle contraction through
tropomyosin and troponin, we have produced mutant actins using Dictyostelium
discoideum. We focused on the sequence 228-232 (QTAAS) that is located in
subdomain 4 of actin, because the chimera actin in which this sequence was
replaced by KAYKE showed not only poorer tropomyosin binding but also the
unexpected "higher Ca(2+) activation" [Saeki, K., et al. (1996) Biochemistry 35,
14465-14472]. We found that this higher Ca(2+) activation is solely due to the
A230Y mutagenesis. Because A230Y mutant actin showed normal tropomyosin binding,
the higher Ca(2+) activation is not the consequence of poorer tropomyosin
binding. The significance of these results is discussed in view of a three-state
model [McKillop, D. F., Geeves, M. A. (1993) Biophys. J. 65, 693-701].
PMID- 10684613
TI - The carbonyl group of glutamic acid-795 is essential for gastric H+,K+-ATPase
activity.
AB - To study the role of Glu795offresent in the fifth transmembrane domain of the
alpha-subunit of gastric H+,K+-ATPase, several mutants were generated and
expressed in Sf9 insect cells. The E795Q mutant had rather similar properties as
the wild-type enzyme. The apparent affinity for K+ in both the ATPase reaction
and the dephosphorylation of the phosphorylated intermediate was even slightly
enhanced. This indicates that the carbonyl group of Glu795 is sufficient for
enzymatic activity. This carbonyl group, however, has to be at a particular
position with respect to the other liganding groups, since the E795D and E795N
mutants showed a strongly reduced ATPase activity, a lowered apparent K+
affinity, and a decreased steady-state phosphorylation level. In the absence of a
carbonyl residue at position 795, the K+ sensitivity was either strongly
decreased (E795A) or completely absent (E795L). The mutant E795L, however, showed
a SCH 28080 sensitive ATPase activity in the absence of K+, as well as an
enhanced spontaneous dephosphorylation rate, that could not be further enhanced
by K+, suggesting that this mutant mimicks the filled K+ binding pocket. The
results indicate that the Glu795 residue is involved in K+-stimulated ATPase
activity and K+-induced dephosphorylation of the phosphorylated intermediate.
Glu795 might also be involved in H+ binding during the phosphorylation step,
since the mutants E795N, E795D, and E795A showed a decrease in the
phosphorylation rate as well as in the apparent ATP affinity in the
phosphorylation reaction. This indicates that Glu795 is not only involved in K+
but might also play a role in H+ binding.
PMID- 10684614
TI - Active-site-directed photolabeling of the melibiose permease of Escherichia coli.
AB - Covalent photolabeling of the melibiose permease (MelB) of Escherichia coli has
been undertaken with the sugar analogue [(3)H]-p-azidophenyl alpha-D
galactopyranoside ([(3)H]-alpha-PAPG) with the purpose of identifying the domains
forming the MelB sugar-binding site. We show that alpha-PAPG is a high-affinity
substrate of MelB (K(d) = 1 x 10(-)(6) M). Its binding to or transport by MelB is
Na-dependent and is competitively prevented by melibiose or by the high-affinity
ligand p-nitrophenyl alpha-D-galactopyranoside (alpha-NPG). Membrane vesicles
containing overexpressed histidine-tagged recombinant MelB were photolabeled in
the presence of [(3)H]-alpha-PAPG by irradiation with UV light (lambda = 250 nm).
Eighty-five percent of the radioactivity covalently associated with the vesicles
was incorporated in a polypeptide corresponding to MelB monomer. MelB labeling
was completely prevented by an excess of melibiose or alpha-NPG during the assay.
Radioactivity analysis of CNBr cleavage or limited proteolysis products of the
purified [(3)H]-alpha-PAPG-labeled transporter suggests that several domains of
MelB are targets for labeling. One of the labeled CNBr cleavage products is a
peptide with an apparent molecular mass of 5.5 kDa. It is shown that (i) its
amino acid sequence is that of the Asp124-Met181 domain of MelB (7.5 kDa), which
includes the cytoplasmic loop 4-5 connecting helices IV and V, the hydrophobic
helix V, and the outer loop connecting helices V-VI, and (ii) that Arg141 in loop
4-5 is the only labeled amino acid of this peptide. Labeling of loop 4-5 provides
independent evidence that this specific domain plays a significant role in MelB
transport. Comparison with the well-characterized equivalent domain of LacY
suggests that sugar transporters with similar structure and substrate specificity
may have conserved domains involved in sugar recognition.
PMID- 10684615
TI - Moving a microtubule may require two heads: a kinetic investigation of monomeric
Ncd.
AB - Ncd is a minus-end-directed microtubule motor and a member of the kinesin
superfamily. The Ncd dimer contains two motor domains, and cooperative
interactions between the heads influence the interactions of each respective
motor domain with the microtubule. The approach we have taken to understand the
cooperativity between the two motor domains is to analyze the ATPase cycle of
dimeric MC1 and monomeric MC6. The steps in the ATPase cycle where cooperativity
occurs can be identified by comparing the two mechanisms. The rate-limiting step
in the MC6 mechanism is ADP release at 3.4 s(-)(1). The observed rate constant
for ATP-induced dissociation from the microtubule is 14 s(-)(1). However, the
relative amplitude associated with MC6 dissociation is extremely small in
comparison to the amplitude associated with dimeric MC1 dissociation kinetics.
The amplitude data indicate that monomeric MC6 does not detach from the
microtubule during the initial turnovers of ATP, and ATP hydrolysis is uncoupled
from movement. The results show that cooperative interactions between the motor
domains of the dimer are required for ATP-dependent dissociation; therefore, one
function of the partner motor domain may be to weaken the interaction of the
adjacent head with the microtubule.
PMID- 10684616
TI - Functional properties of the heme propionates in cytochrome c oxidase from
Paracoccus denitrificans. Evidence from FTIR difference spectroscopy and site
directed mutagenesis.
AB - By specific (13)C labeling of the heme propionates, four bands in the reduced
minus-oxidized FTIR difference spectrum of cytochrome c oxidase from Paracoccus
denitrificans have been assigned to the heme propionates [Behr, J., Hellwig, P.,
Mantele, W., and Michel, H. (1998) Biochemistry 37, 7400-7406]. To attribute
these signals to the individual propionates, we have constructed seven cytochrome
coxidase variants using site-directed mutagenesis of subunit I. The mutant
enzymes W87Y, W87F, W164F, H403A, Y406F, R473K, and R474K were characterized by
measurement of enzymatic turnover, proton pumping activity, and Vis and FTIR
spectroscopy. Whereas the mutant enzymes W164F and Y406F were found to be
structurally altered, the other cytochrome c oxidase variants were suitable for
band assignment in the infrared. Reduced-minus-oxidized FTIR difference spectra
of the mutant enzymes were used to identify the ring D propionate of heme a as a
likely proton acceptor upon reduction of cytochromic oxidase. The ring D
propionate of heme a(3) might undergo conformational changes or, less likely, act
as a proton donor.
PMID- 10684617
TI - pH-dependent unfolding of aspergillopepsin II studied by small-angle X-ray
scattering.
AB - Aspergillopepsin II (EC 3.4.23.6) secreted from the fungus Aspergillus niger var.
macrosporus is a non-pepsin-type acid proteinase. It consists of two polypeptide
chains (i.e., a heavy chain and a light chain), which are bound noncovalently to
each other. The pH titration analysis using small-angle X-ray scattering (SAXS)
as well as circular dichroism (CD) and gel filtration indicated that the enzyme
was unfolded around a neutral pH with concomitant dissociation of the two chains.
Detailed analyses showed that the midpoint pH values for the unfolding are not
coincident with one another (pH 6.1 in circular dichroism and gel filtration, pH
6.4 in zero-angle intensity of SAXS, pH 6.8 in radius of gyration). The
difference between these values suggested the existence of an intermediate state
during the unfolding. Further analyses of the SAXS data showed that the heavy
chain just after the dissociation still kept molecular compactness and that it
gradually increased its dimensions as the pH was further raised. Noncoincidence
of the two phenomena (i.e., chain dissociation and swelling) led to elucidation
of a novel intermediate state during unfolding, which was confirmed by the
subsequent singular value decomposition (SVD) analysis.
PMID- 10684618
TI - Characterization of the second metal site on avian phosphoenolpyruvate
carboxykinase.
AB - Chicken liver phosphoenolpyruvate carboxykinase (PEPCK) requires two divalent
cations for activity. One cation activates the enzyme through a direct
interaction with the protein at site n(1). The second cation, at site n(2), acts
in the cation-nucleotide complex that serves as a substrate. The Co(3+)(n(1))
PEPCK and Cr(3+)(n(1))-PEPCK complexes were used to examine the kinetic,
mechanistic, and binding properties of the n(2) metal. EPR studies performed on
the Co(3+)(n(1))-PEPCK-GTP complex yielded a stoichiometry of 1 mol of Mn(2+)
bound per mole of Co(3+)(n(1))-PEPCK-GTP with a K(D) of 5 microM. PRR studies
show a significant enhancement for the Co(3+)(n(1))-PEPCK-Mn(2+)(n(2))-GDP
complex. A change in enhancement in the presence of PEP suggests that PEP
interacts with the second metal ion. The distance between Mn(2+) at site n(2) on
PEPCK and the cis and trans protons and the (31)P of PEP are 7.0, 7.5, and 4.8 A,
respectively, as measured by high-resolution NMR. PRR studies of the Co(3+)(n(1))
PEPCK-Mn(2+)(n(2))-GTP and Co(3+)(n(1))-PEPCK-Mn(2+)(n(2))-GDP complexes as a
function of frequency (omega(I)) were used to estimate the hydration number of
the n(2) metal to be between 0.5 and 0.7. The metal-metal distance for the
M(n(1))-PEPCK-M(n(2))-GTP complex is approximately 8.3 A, and the distance for
the M(n(1))-PEPCK-M(n(2))-GDP complex is 9.2 A. The change in the metal-metal
distance suggests a conformational change at the active site of PEPCK occurs
during catalysis. The Co(3+)(n(1))-PEPCK complex was incubated with Co(2+), GTP,
and H(2)O(2) to create a doubly labeled and inactive Co(3+)(n(1))-PEPCK
Co(3+)(n(2))-GTP complex. The Co(3+)(n(1))-PEPCK-Co(3+)(n(2))-GTP complex was
digested by LysC, and two cobalt-containing peptides were purified using RP-HPLC.
Amino acid sequencing of the second cobalt-containing peptide points to the
region of Tyr57-Lys76 of PEPCK. Asp66, Asp69, and Glu74 are all feasible ligands
to the site n(2) metal.
PMID- 10684619
TI - Solution 1H NMR study of the heme cavity and folding topology of the abbreviated
chain 118-residue globin from the cyanobacterium Nostoc commune.
AB - The globin from the cyanobacterium Nostoc commune, abbreviated GlbN, which
appears to serve as a part of a terminal oxidase rather than as a respiratory
pigment, displays relatively normal O2 binding properties, despite the highly
abbreviated polypeptide chain, (118 residues) relative to more conventional
globins [Thorsteinsson, M. V. , Bevan, D. R., Potts, M., Dou, Y., Eich, R. F.,
Hargrove, M. S., Gibson, Q. H., and Olson, J. S. (1999) Biochemistry 38, 2117
2126]. The nature of the heme cavity and the general folding topology of this
cyanoglobin were investigated by solution 1H NMR to establish the extent to
which, and the manner in which, this compact globin adheres to the standard
globin fold. This represents by far the smallest globin subjected to structural
analysis. The paramagnetic cyanomet derivative was selected because its
characteristically large magnetic anisotropy imparts significant dipolar shifts
which both improve resolution to greatly facilitate assignments and serve as
indicators of the folding topology of the globin. Identification of the axial His
70 and highly conserved Phe 35 (CD1) determined the absolute orientation of the
heme and proximal His. Sequential assignments of four helical and one loop
segments, which exhibit dipolar contacts to the heme and among each other,
confirm the presence of well-conserved F, G, and H helices and the FG corner. The
majority of the abbreviation of the chain relative to the more conventional
length globins is accommodated in the A-D helices, of which the last is
completely missing. The distal residue which provides a H-bond to bound ligand is
identified as Gln 43, but the expected helical position E7 could not be
confirmed. His 46, placed at position E10, is found to adopt alternate
orientations into, and out of, the heme cavity depending on protonation state,
suggesting the presence of a Bohr effect at low pH. It is shown that the dipolar
shifts exhibited by backbone protons for the assigned residues conform well to
those observed for other cyanomet globins and further support a conserved Mb
fold. Perturbed medium-range dipolar contacts and the pH-independent backbone
proton lability of the F helix are interpreted in terms of a holoprotein which is
less stable than a conventional length globin.
PMID- 10684620
TI - Iso-mechanism of nitroalkane oxidase: 1. Inhibition studies and activation by
imidazole.
AB - The flavoprotein nitroalkane oxidase catalyzes the oxidation of primary and
secondary nitroalkanes to aldehydes and ketones, respectively, transferring
electrons to oxygen to form hydrogen peroxide. The steady-state kinetic mechanism
of the active flavin adenine dinucleotide-(FAD-) containing form of the enzyme
has been determined with nitroethane at pH 7 to be bi-ter ping-pong, with oxygen
reacting with the free reduced enzyme after release of the aldehyde product. The
V(max) value is 5.5 +/- 0.3 s(-)(1) and the K(m) values for nitroethane and
oxygen are 3.3 +/- 0.6 and 0.023 +/- 0.007 mM, respectively. The free reduced
enzyme forms a dead-end complex with nitroethane, with a K(ai) value of 30 +/- 6
mM. Acetaldehyde and butyraldehyde are noncompetitive inhibitors versus
nitroethane due to formation of a dead-end complex between the oxidized enzyme
and the product. Acetaldehyde is an uncompetitive inhibitor versus oxygen,
indicating that an irreversible isomerization of the free reduced enzyme occurs
before the reaction with oxygen. Addition of unprotonated imidazole results in a
5-fold increase in the V(max) value, while the V/K values for nitroethane and
oxygen are unaffected. A 5-fold increase in the K(ai) value for nitroethane and a
6.5-fold increase in the K(ii) value for butyraldehyde are observed in the
presence of imidazole. These results are consistent with the isomerization of the
free reduced enzyme being about 80% rate-limiting for catalysis and with a model
in which unprotonated imidazole accelerates the rate of isomerization.
PMID- 10684621
TI - Mechanism of nitroalkane oxidase: 2. pH and kinetic isotope effects.
AB - Nitroalkane oxidase catalyzes the oxidation of nitroalkanes to aldehydes or
ketones with production of nitrite and hydrogen peroxide. pH and kinetic isotope
effects with [1, 1-(2)H(2)]nitroethane have been used to study the mechanism of
this enzyme. The V/K(ne) pH profile is bell-shaped. A group with a pK(a) value of
about 7 must be unprotonated and one with a pK(a) value of 9.5 must be protonated
for catalysis. The lower pK(a) value is seen also in the pK(is) profile for the
competitive inhibitor valerate, indicating that nitroethane has no significant
external commitments to catalysis. The (D)(V/K)(ne) value is pH-independent with
a value of 7.5, whereas the (D)V(max) value increases from 1.4 at pH 8.2 to a
limiting value of 7.4 below pH 5. The V(max) pH profile decreases at low and high
pH, with pK(a) values of 6.6 and 9.5, respectively. Imidazole, which activates
the enzyme, affects the V(max) but not the V/K(ne) pH profile. In the presence of
imidazole at pH 7 the (D)V(max) value increases to a value close to the intrinsic
value, consistent with cleavage of the carbon-hydrogen bond of the substrate
being fully rate-limiting for catalysis in the presence of imidazole.
PMID- 10684622
TI - pH-dependent changes in the in vitro ligand-binding properties and structure of
human clusterin.
AB - Clusterin is a glycoprotein which is locally overexpressed at sites of tissue
damage or stress, leading to the proposal that it may be a cytoprotective
protein. It has been shown that clusterin has chaperone-like activity, being able
to protect proteins against precipitation under stress conditions. It has also
been shown that local acidosis is common at sites of tissue damage or stress. We
asked whether acidic pH induces structural changes in clusterin and enhances its
ability to bind to other proteins. We found by affinity chromatography and ELISA
that the binding of clusterin to glutathione-S-transferase, IgG, apolipoprotein A
I, and complement protein C9 was enhanced at mildly acidic compared to
physiological pH. Analytical ultracentrifugation and gel filtration studies
revealed that clusterin exists in different polymerization states with monomer
occurring preferentially at pH 5.5 and multimeric species at pH 7.5. Although
circular dichroism showed little difference in the alpha-helical and beta-sheet
contents of clusterin at pH 5 compared to pH 7.5, evidence for pH-dependent
structural changes in clusterin was obtained from fluorescence experiments. pH
titrations showed reversible changes in the fluorescence of tryptophan residues
in clusterin. There was a reversible 2-fold increase in the fluorescence of the
extrinsic probe 4, 4'-bis(1-anilinonaphthalene-8-sulfonate) bound to clusterin at
pH 5. 5 compared to pH 7.5. There was also a 3.5-fold increase in fluorescence
resonance energy transfer from tryptophan residues in clusterin to 4,4'-bis(1
anilinonaphthalene-8-sulfonate) at pH 5.5 compared to pH 7.5. These data suggest
that pH-induced changes in the structure of clusterin are responsible for its
enhanced ability to bind protein ligands at mildly acidic pH.
PMID- 10684623
TI - Mutation of R116C results in highly oligomerized alpha A-crystallin with modified
structure and defective chaperone-like function.
AB - An autosomal dominant congenital cataract in human is associated with mutation of
Arg-116 to Cys (R116C) in alpha A-crystallin. To investigate the molecular basis
of cataract formation, rat alpha A-crystallin cDNA was cloned into pET-23d(+),
and the site-directed mutants S142C (similar to wild-type human alpha A) and
R116C/S142C or R116C (similar to human R116C variant) were generated. These were
expressed in E. coli and the recombinant alpha A-crystallins purified by
Sephacryl size-exclusion chromatography. The chaperone-like function of mutant
R116C determined at 37 degrees C with insulin and alcohol dehydrogenase as target
proteins was about 40% lower than those of wild-type and mutant S142C. Based on
size-exclusion chromatography data, the oligomeric size of the R116C mutant was
about 2000 kDa at 25 degrees C, 1400 kDa at 37 degrees C, and 900 kDa at 45
degrees C. In comparison, alpha A-wild-type and alpha A-S142C ranged from 477 to
581 kDa. Heat stability studies corroborated the effect of temperature on the
dynamic quaternary structure of the R116C mutant. Circular dichroism spectra
showed secondary and tertiary structural changes, and ANS fluorescence spectra
showed loss of surface hydrophobicity in the R116C mutant. These findings suggest
that the molecular basis for the congenital cataract with the alpha A-R116C
mutation is due to the generation of a highly oligomerized alpha A-crystallin
having a modified structure and decreased chaperone-like function.
PMID- 10684624
TI - Human immunodeficiency virus type 1 reverse transcriptase dimer destabilization
by 1-[Spiro[4"-amino-2",2" -dioxo-1",2" -oxathiole-5",3'-[2', 5'-bis-O-(tert
butyldimethylsilyl)-beta-D-ribofuranosyl]]]-3-ethylthy mine.
AB - The nonnucleoside inhibitor binding pocket is a well-defined region in the p66
palm domain of the human immunodeficiency virus type-1 reverse transcriptase (HIV
1 RT). This binding pocket opens toward the interface of the p66/p51 heterodimer
and we have investigated whether ligand binding at or near this site induces
structural changes that have an impact on the dimeric structure of HIV-1 RT. 1
[2',5'-bis-O-(tert-butyldimethylsilyl]-3'-spiro-5' '-(4' '-amino-1' ',2' '
oxathiole-2' ',2' '-dioxide)-3-ethylthymine (TSAOe(3)T) was found to destabilize
the subunit interactions of both the p66/p51 heterodimer and p66/p66 homodimer
enzymes. The Gibbs free energy of dimer dissociation (DeltaG(D)(H)2(O)) is
decreased with increasing concentrations of TSAOe(3)T, resulting in a loss in
dimer stability of 4.0 and 3.2 kcal/mol for the p66/p51 and p66/p66 HIV-1 RT
enzymes, respectively. This loss of energy is not sufficient to induce the
dissociation of the subunits in the absence of denaturant. This destabilizing
effect seems to be unique for TSAOe(3)T, since neither the tight-binding
inhibitor UC781 nor nevirapine showed any effects on the stability of HIV-1 RT
dimers. TSAOe(3)T was unable to destabilize the subunit interactions of the E138K
mutant enzyme, which exhibits significant resistance to TSAOe(3)T inhibition.
Molecular modeling of TSAOm(3)T into the nonnucleoside inhibitor binding pocket
of wild-type RT suggests that it makes significant interactions with the p51
subunit of the enzyme, a feature that has not been observed with other types of
nonnucleoside inhibitors. The observed destabilization of the dimeric HIV-1 RT
may result from structural/conformational perturbations at the reverse
transcriptase subunit interface.
PMID- 10684625
TI - Potentiation and inhibition of bFGF binding by heparin: a model for regulation of
cellular response.
AB - Basic fibroblast growth factor (bFGF) binds to cell surface tyrosine kinase
receptor proteins and to heparan sulfate proteoglycans. The interaction of bFGF
with heparan sulfate on the cell surface has been demonstrated to impact receptor
binding and biological activity. bFGF receptor binding affinity is reduced on
cells that do not express heparan sulfate. The addition of soluble heparin or
heparan sulfate has been demonstrated to rescue the bFGF receptor binding
affinity on heparan sulfate deficient cells yet has also been shown to inhibit
binding under some conditions. While the chemical requirements of the heparin
bFGF-receptor interactions have been studied in detail, the possibility that
heparin enhances bFGF binding in part by physically associating with the cell
surface has not been fully evaluated. In the study presented here, we have
investigated the possibility that heparin binding to the cell surface might play
a role in modulating bFGF receptor binding and activity. Balb/c3T3 cells were
treated with various concentrations of sodium chlorate, so as to express a range
of endogenous heparan sulfate sites, and [(125)I]bFGF binding was assessed in the
presence of a range of heparin concentrations. Low concentrations of heparin (0.1
30 nM) enhanced bFGF receptor binding to an extent that was inversely
proportional to the amount of endogenous heparan sulfate sites present. At high
concentrations (10 microM), heparin inhibited bFGF receptor binding in cells
under all conditions. The ability of heparin to stimulate and inhibit bFGF
receptor binding correlated with altered bFGF-stimulated tyrosine kinase activity
and cell proliferation. Under control and chlorate-treated conditions, [(125)
I]heparin was observed to bind with a high affinity to a large number of binding
sites on the cells (K(d) = 57 and 50 nM with 3.5 x 10(6) and 3.6 x 10(6)
sites/cell for control and chlorate-treated cells, respectively). A mathematical
model of this process revealed that the dual functions of heparin in bFGF binding
were accurately represented by heparin cell binding-mediated stimulation and
soluble heparin-mediated inhibition of bFGF receptor binding.
PMID- 10684626
TI - Investigations of the myoglobin cavity mutant H93G with unnatural imidazole
proximal ligands as a modular peroxide O-O bond cleavage model system.
AB - A general inability to elucidate extensive variations in the electronic
characteristics of proximal heme iron ligands in heme proteins has hampered
efforts to obtain a clear understanding of the role of the proximal heme iron
ligand in the activation of oxygen and peroxide. The disadvantage of the
frequently applied site-directed mutagenesis technique is that it is limited by
the range of natural ligands available within the genetic code. The myoglobin
cavity mutant H93G [Barrick, D. (1994) Biochemistry 33, 6546-6554] has its
proximal histidine ligand replaced with glycine, a mutation which leaves an open
cavity capable of accommodating a variety of unnatural potential proximal
ligands. We have carried out investigations of the effect of changing the
electron donor characteristics of a variety of substituted imidazole proximal
ligands on the rate of formation of myoglobin compound II and identified a
correlation between the substituted imidazole N-3 pK(a) (which provides a measure
of the electron donor ability of N-3) and the apparent rate of formation of
compound II. A similar rate dependence correlation is not observed upon binding
of azide. This finding indicates that O-O bond cleavage and not the preceding
peroxide binding step is being influenced by the electron donor characteristics
of the substituted imidazole ligands. The proximal ligand effects are clearly
visible, but their overall magnitude is quite low (1.7-fold increase in the O-O
bond cleavage rate per pK(a) unit). This appears to provide support for recent
commentaries which concluded that the partial ionization of the proximal
histidine ligand in typical heme peroxidases may not be enough of an influence to
provide a mechanistically critical push effect [Poulos, T. L. (1996) JBIC, J.
Biol. Inorg. Chem. 1, 356-359]. Further attempts were made to define the
mechanism of the influence of N-3 pK(a) on O-O bond cleavage by using peracetic
acid and cumene hydroperoxide as mechanistic probes. The observation of heme
destruction in these reactions indicates that displacement of the proximal
imidazole ligands by peracetic acid or cumene hydroperoxide has occurred. A
combination mutation (H64D/H93G) was prepared with the objective of observing
compound I of H64D/H93G with substituted imidazoles as proximal ligands upon
reaction with H(2)O(2). This double mutant was found to simultaneously bind
imidazole to both axial positions, an arrangement which prevents a reaction with
H(2)O(2).
PMID- 10684627
TI - Hydrogen exchange at the core of Escherichia coli alkaline phosphatase studied by
room-temperature tryptophan phosphorescence.
AB - The room-temperature tryptophan (Trp) phosphorescence lifetime is sensitive to
details of the local environment and has been shown to increase significantly in
some proteins following H-D exchange. Careful analysis of the phosphorescence
lifetime distribution of Trp 109 in Escherichia coli alkaline phosphatase (AP) in
solution as a function of time during the H-D exchange shows that this process
corresponds to a two-state reaction resulting from the deuteration of a single,
specific hydrogen in the core of the protein. The absence of a pH dependence of
the exchange rate suggests that the exchange is not an EX2 process, and
therefore, a certain degree of unfolding is required for exchange to occur. This
discovery opens up the use of phosphorescence-detected hydrogen exchange as a
sensitive tool for monitoring the local susceptibility and activation energy for
exchange in proteins having a phosphorescent Trp and, for example, for studying
the effects of local mutations upon that susceptibility.
PMID- 10684628
TI - Effect of loop sequence and size on DNA aptamer stability.
AB - The thrombin aptamer is a 15-mer oligodeoxyribonucleotide that folds into a
unimolecular quadruplex consisting of a stack of two guanine quartets connected
by two external loops and one central loop and possesses a high affinity for
thrombin. We have undertaken a systematic examination, in KCl, of the
thermodynamic stability of thrombin aptamer analogues containing sequence
modifications in one or more of the loops, as well as in the number of quartets.
UV melting studies have been carried out to obtain the relevant thermodynamic
parameters for these aptamers. van't Hoff analysis of these data, with a two
state model for unimolecular denaturation, gave excellent fits to the
experimental observations. Thermodynamic analysis indicates that the central loop
sequence in the parent aptamer is optimal for stability. Modifications in this or
other loops can effect either DeltaH degrees, DeltaS degrees, or both. Addition
of a single G at the 5'-end decreases stability while addition of a G at the 3'
end increases stability. Differential scanning calorimetry experiments on the
thrombin aptamer reveal that a heat capacity change, not detected by UV
measurements, accompanies the unfolding of the aptamer.
PMID- 10684629
TI - Binding of fatty acids and peroxisome proliferators to orthologous fatty acid
binding proteins from human, murine, and bovine liver.
AB - Liver-type fatty acid binding protein (L-FABP) has been proposed to be involved
in the transport of fatty acids and peroxisome proliferators from the cytosol
into the nucleus for interaction with the peroxisome proliferator-activated
receptors (PPARs). On the basis of this premise, we investigated by isothermal
titration calorimetry the binding of myristic, stearic, oleic, and
docosahexaenoic acids to three orthologous L-FABPs and compared these results to
those obtained for several xenobiotics [Wy14,643, bezafibrate, 5,8,11,14
eicosatetraynoic acid (ETYA), and BRL48,482] known for their peroxisome
proliferating activity in rodents. Recombinant human, murine, and bovine L-FABPs
were analyzed and the thermodynamic data were obtained. Our studies showed that
fatty acids bound with a stoichiometry of 2:1, fatty acid to protein, with
dissociation constants for the first binding site in the nanomolar range. With
dissociation constants above 1 microM the drug peroxisome proliferators showed
weaker binding, with the exception of arachidonate analogue ETYA, which bound
with a similar affinity as the natural fatty acid. Some of the thermodynamic data
obtained for fatty acid binding could be explained by differences in protein
structure. Moreover, our results revealed that binding affinities were not
determined by ligand solubility in the aqueous phase.
PMID- 10684630
TI - Insulin-like signaling in yeast: modulation of protein phosphatase 2A, protein
kinase A, cAMP-specific phosphodiesterase, and glycosyl-phosphatidylinositol
specific phospholipase C activities.
AB - Previously, we have described significant effects of human insulin on glucose
metabolism in the yeast Saccharomyces cerevisiae under conditions of growth
limitation. These regulations apparently rely on a transmembrane receptor capable
of binding human insulin and responding by tyrosine/serine phosphorylation of a
specific set of polypeptides [Muller, G., Rouveyre, N., Crecelius, A., and
Bandlow, W. (1998) Biochemistry 37, 8683-8695; Muller, G., Rouveyre, N., Upshon,
C., Gross, E., and Bandlow, W. (1998) Biochemistry 37, 8696-8704; Muller, G.,
Rouveyre, N., Upshon, C., and Bandlow, W. (1998) Biochemistry 37, 8705-8713]. To
characterize the molecular link between the initial steps in insulin-like
signaling in yeast and the changes in the activities of glycogen synthase and
glycogen phosphorylase, we examined here the effects of human insulin on a set of
key regulatory enzymes of glycogen metabolism, protein phosphatase 2A (PP2A),
cAMP-specific phosphodiesterase (cAMP-PDE), and protein kinase A (PKA). PP2A was
activated about 2-fold by insulin in spheroplasts and in intact cells, whereas
the fraction of active PKA was significantly reduced in a cAMP-independent manner
as well as through a subsequent up to 3-fold increase in particulate cAMP-PDE
activity accompanied by a 50% decrease in cytosolic cAMP levels. In addition,
glycosyl-phosphatidylinositol-specific phospholipase C (GPI-PLC), which in
isolated rat adipocytes is activated by insulin, was stimulated to up to 5-fold
by glucose and 10-fold by glucose plus insulin in both yeast spheroplasts and
intact cells leading to a concentration-dependent leftward shift of the glucose
response curve for activation of the GPI-PLC. GPI-PLC was most pronouncedly
stimulated by authentic human insulin compared to various insulin analogues and
insulin-like growth factor I. In addition to lipolytic cleavage by GPI-PLC, the
GPI anchor of the cAMP-binding ectoprotein, Gce1p, was secondarily processed by a
rapid proteolytic event. As the GPI-PLC reaction is rate limiting, the efficiency
of the two-step anchor cleavage was significantly increased when insulin was
present together with glucose as compared to glucose alone. The insulin
concentrations effective in modulating PP2A, PKA, cAMP-PDE, and GPI-PLC
activities correlate well with those required for half-saturation of the specific
binding sites as well as for stimulation of protein phosphorylation and glycogen
accumulation. The data suggest that mammalian insulin-sensitive cells and yeast
share (part of) the key regulatory mechanism (consisting of PP2A, PKA, cAMP-PDE,
and GPI-PLC) involved in the transduction of the insulin signal from the
respective receptor systems to glycogen synthase and phosphorylase.
PMID- 10684631
TI - Excitation dynamics and heterogeneity of energy equilibration in the core antenna
of photosystem I from the cyanobacterium Synechocystis sp. PCC 6803.
AB - Energy equilibration in the photosystem I core antenna from the cyanobacterium
Synechocystis sp. PCC 6803 was studied using femtosecond transient absorption
spectroscopy at 298 K. The photosystem I core particles were excited at 660, 693,
and 710 nm with 150 fs spectrally narrow laser pulses (fwhm = 5 nm). Global
analysis revealed three kinetic processes in the core antenna with lifetimes of
250-500 fs, 1.5-2.5 ps, and 20-30 ps. The first two components represent strongly
excitation wavelength-dependent energy equilibration processes while the 20-30 ps
phase reflects the trapping of energy by the reaction center. Excitation into the
blue and red edge of the absorption band induces downhill and uphill energy
flows, respectively, between different chlorophyll a spectral forms of the core.
Excitation at 660 nm induces a 500 fs downhill equilibration process within the
bulk of antenna while the selective excitation of long-wavelength-absorbing
chlorophylls at 710 nm results in a 380 fs uphill energy transfer to the
chlorophylls absorbing around 695-700 nm, presumably reaction center pigments.
The 1.5-2.5 ps phases of downhill and uphill energy transfer are largely
equivalent but opposite in direction, indicating energy equilibration between
bulk antenna chlorophylls at 685 nm and spectral forms absorbing below 700 nm.
Transient absorption spectra with excitation at 693 nm exhibit spectral evolution
within approximately 2 ps of uphill energy transfer to major spectral forms at
680 nm and downhill energy transfer to red pigments at 705 nm. The 20-30 ps
trapping component and P(700) photooxidation spectra derived from data on the 100
ps scale are largely excitation wavelength independent. An additional decay
component of red pigments at 710 nm can be induced either by selective excitation
of red pigments or by decreasing the temperature to 264 K. This component may
represent one of the phases of energy transfer from inhomogeneously broadened red
pigments to P(700). The data are discussed based on the available structural
model of the photosystem I reaction center and its core antenna.
PMID- 10684632
TI - Structural consequences of b- to c-type heme conversion in oxidized Escherichia
coli cytochrome b562.
AB - An NMR characterization of the 98Arg --> Cys variant of iron (III)-containing
cytochrome b562 from Escherichia coli has been performed and the solution
structure obtained. This variant has a covalent bond between the heme and Cys 98,
thus mimicking the heme binding in cytochrome c. The R98C cytochrome is shown to
have a significantly increased stability, compared to that of wild type, toward
thermal and chemical denaturation. In water at 20 degrees C it is 5.60 kJ mol-1
more stable than the WT protein, measured by equilibrium guanidine hydrochloride
denaturation. The structure has been obtained through two-dimensional total
correlation spectroscopy (TOCSY) and nuclear Overhauser effect spectroscopy
(NOESY) experiments and through three-dimensional NOESY-15N heteronuclear
multiple quantum coherence (HMQC). By these methods, 85% of protons and 100% of
backbone nitrogens were assigned. 2145 meaningful nuclear Overhauser effects
(NOEs) (20 NOEs per residue), 45 backbone 3J values, and 397 pseudocontact shifts
were used to obtain a family of 35 members, which were then energy-minimized. The
root-mean-square deviation (RMSD) with respect to the average structure is 0.50
+/- 0.07 for the backbone and 1.01 +/- 0.08 for the heavy atoms. The magnetic
anisotropy resulting from analysis of the pseudocontact shifts indicates an
anisotropy that is an intermediate between that of the wild-type, which is the
smallest, and cytochrome c. The g values confirm a higher anisotropy of the
variant with respect to the wild-type protein. The chirality of the heme 2 alpha
carbon is the same as that in all naturally occurring cytochromes c. The overall
secondary structure and tertiary structure are very similar to the wild type. The
removal of Arg 98 causes a change in the pH-dependent properties. The pKa,
proposed to be due to deprotonation of the coordinated histidine, is 1.5 units
higher than in the wild type, consistent with the lack of the positive charge of
Arg 98 close to the ionizable group. This is further support for the coordinated
histidine being the titratable group with an alkaline pKa in the wild-type
protein. The pattern of the shifts of the heme methyl groups is different than in
the wild-type protein, presumably due to alteration of the electronic structure
by the presence of the covalent bond between the protein and the heme. The
difference in stability between the variant and wild-type protein is discussed in
terms of the structural information.
PMID- 10684633
TI - Cloning of amadoriase I isoenzyme from Aspergillus sp.: evidence of FAD
covalently linked to Cys342.
AB - Amadoriases are a novel class of FAD enzymes which catalyze the oxidative
deglycation of glycated amino acids to yield corresponding amino acids,
glucosone, and H(2)O(2). We previously reported the purification and
characterization of two amadoriase isoenzymes from Aspergillus fumigatus and the
molecular cloning of amadoriase II. To identify the primary structure of
amadoriase I, we prepared a cDNA library from Aspergillus fumigatus and isolated
a clone using a probe amplified by polymerase chain reaction with primers
designed according to the partial amino acid sequences from peptide mapping. The
primary structure of the enzyme deduced from the nucleotide sequence comprises
445 amino acid residues. The enzyme contains 1 mol of FAD as a cofactor, which is
covalently linked to Cys342, as determined by mutagenesis analysis, matrix
assisted laser desorption/ionization time-of-flight mass spectrometry, and
electrospray ionization-collisional-activated dissociation tandem mass
spectrometry. Sequence alignment studies show that amadoriase I has 22% homology
with monomeric sarcosine oxidase in which FAD is also linked to a homologous Cys
residue. Amadoriases are of potential importance as tools for uncoupling
hyperglycemia and glycation reactions that are thought to play a role in diabetic
complications.
PMID- 10684634
TI - Catalytic mechanism of a C-C hydrolase enzyme: evidence for a gem-diol
intermediate, not an acyl enzyme.
AB - 2-Hydroxy-6-keto-nona-2,4-diene 1,9-dioic acid 5,6-hydrolase (MhpC) from
Escherichia coli catalyses the hydrolytic cleavage of the extradiol ring fission
product on the phenylpropionate catabolic pathway and is a member of the
alpha/beta hydrolase family. The catalytic mechanism of this enzyme has
previously been shown to proceed via initial ketonization of the dienol substrate
(Henderson, I. M. J., and Bugg, T. D. H. (1997) Biochemistry 36, 12252-12258),
followed by stereospecific fragmentation. Despite the implication of an active
site serine residue in the alpha/beta hydrolase family, attempts to verify a
putative acyl enzyme intermediate by radiochemical trapping methods using a (14)C
labeled substrate yielded a stoichiometry of <1% covalent intermediate, which
could be accounted for by nonenzymatic processes. In contrast, incorporation of 5
6% of two atoms of (18)O from H(2)(18)O into succinic acid was observed using the
natural substrate, consistent with the reversible formation of a gem-diol
intermediate. Furthermore, time-dependent incorporation of (18)O from H(2)(18)O
into the carbonyl group of a nonhydrolysable analogue 4-keto-nona-1,9-dioic acid
was observed in the presence of MhpC, consistent with enzyme-catalyzed attack of
water at the ketone carbonyl. These results favor a catalytic mechanism involving
base-catalyzed attack of water, rather than nucleophilic attack of an active site
serine. The implication of this work is that the putative active site serine in
this enzyme may have an alternative function, for example, as a base.
PMID- 10684635
TI - Superinduction of cyclooxygenase-2 by NO(*) and agonist challenge involves
transcriptional regulation mediated by AP-1 activation.
AB - Superinduction of cyclooxygenase-2, in murine RAW 264.7 macrophages as well as
human pulmonary type II A549 epithelial cells, is achieved by the simultaneous
addition of agonists such as lipopolysaccharide or interleukin-1beta and the
NO(*) donor S-nitrosoglutathione. NO(*)-evoked superinduction of cyclooxygenase-2
in the presence of agonists was dose-dependent and required transcriptional as
well as translational regulation. We sought to further analyze NO(*)-elicited
superinduction at the level of the transcription factor NF-kappaB that is
obligatory for cyclooxygenase-2 expression. NO(*)-mediated NF-kappaB activation
was restricted to low concentrations of S-nitrosoglutathione (50-200 microM),
while a higher dose of S-nitrosoglutathione (1 mM) was ineffective. Not observing
a correlation between NF-kappaB activation and cyclooxygenase-2 expression under
NO(*)-delivery stimulated our interest in analyzing AP-1. NO(*) efficiently
activated AP-1 at all concentrations tested. The involvement of AP-1 in promoting
cyclooxygenase-2 superinduction was established in cells transfected with the
dominant-negative c-Jun mutant, TAM-67. Enhanced expression of cyclooxygenase-2
by lipopolysaccharide/S-nitrosoglutathione-treatment was attenuated in TAM-67
transfectants, while the response to lipopolysaccharide alone remained
unaffected. We conclude that AP-1 activation exclusively conveys the NO(*) signal
that is required for superinduction of cyclooxygenase-2. Superinduction of
cyclooxygenase-2 is restricted to a situation where both, NF-kappaB and AP-1 are
activated. Under inflammatory conditions this might be achieved by the
costimulatory signals provided by agonist challenge and NO(*).
PMID- 10684636
TI - Characterization of the binding interface between the E-domain of staphylococcal
protein A and an antibody Fv-fragment
PMID- 10684637
TI - Abstracts, division of biological chemistry, 219th national meeting of the
american chemical society, march 26-30, 2000
PMID- 10684638
TI - Structure of sterol carrier protein 2 at 1.8 A resolution reveals a hydrophobic
tunnel suitable for lipid binding.
AB - Sterol carrier protein 2, also known as nonspecific lipid transfer protein is a
ubiquitous, small, basic protein of 13 kDa found in animals. Its primary
structure is highly conserved between different species, and it has been
implicated in the intracellular transport of lipids and in a wide range of other
in vitro functions related to sterol and fatty acid metabolism. Sterol carrier
protein 2 deficiency in mice leads to elevated concentrations of phytanic acid in
the serum and causes hepatocarcinogenesis. However, its actual physiological role
is still unknown. Although sterol carrier protein 2 has been studied extensively
in the past 20 years, very little is known concerning its three-dimensional
structure. The crystal structure of rabbit sterol carrier protein 2, determined
at 1.8 A resolution with the MIRAS method, shows a unique alpha/beta-fold. The
core of this protein forms a five-stranded antiparallel beta-sheet flanked by
five helices. A C-terminal segment (residues 114-123), together with part of the
beta-sheet and four alpha-helices, form a hydrophobic tunnel providing the
environment for apolar ligands such as fatty acids and fatty acyl-coenzyme As.
Structurally well-characterized nonspecific lipid transfer proteins from plants
have hydrophobic tunnel-like cavities, which were identified as the binding site
for fatty acids and related apolar ligands. Despite the fact that plant
nonspecific lipid transfer proteins are smaller proteins than sterol carrier
protein 2, show no sequence homology to sterol carrier protein 2, and are
structurally unrelated, the cavities of these two classes of proteins are very
similar with respect to size, shape, and hydrophobicity, suggesting a common
functional role.
PMID- 10684639
TI - Crystal structures of a low-molecular weight protein tyrosine phosphatase from
Saccharomyces cerevisiae and its complex with the substrate p-nitrophenyl
phosphate.
AB - Low-molecular weight protein tyrosine phosphatases are virtually ubiquitous,
which implies that they have important cellular functions. We present here the
2.2 A resolution X-ray crystallographic structure of wild-type LTP1, a low
molecular weight protein tyrosine phosphatase from Saccharomyces cerevisiae. We
also present the structure of an inactive mutant substrate complex of LTP1 with p
nitrophenyl phosphate (pNPP) at a resolution of 1.7 A. The crystal structures of
the wild-type protein and of the inactive mutant both have two molecules per
asymmetric unit. The wild-type protein crystal was grown in HEPES buffer, a
sulfonate anion that resembles the phosphate substrate, and a HEPES molecule was
found with nearly full occupancy in the active site. Although the fold of LTP1
resembles that of its bovine counterpart BPTP, there are significant changes
around the active site that explain differences in their kinetic behavior. In the
crystal of the inactive mutant of LTP1, one molecule has a pNPP in the active
site, while the other has a phosphate ion. The aromatic residues lining the walls
of the active site cavity exhibit large relative movements between the two
molecules. The phosphate groups present in the structures of the mutant protein
bind more deeply in the active site (that is, closer to the position of
nucleophilic cysteine side chain) than does the sulfonate group of the HEPES
molecule in the wild-type structure. This further confirms the important role of
the phosphate-binding loop in stabilizing the deep binding position of the
phosphate group, thus helping to bring the phosphate close to the thiolate anion
of nucleophilic cysteine, and facilitating the formation of the phosphoenzyme
intermediate.
PMID- 10684640
TI - Crystal structure of flavocetin-A, a platelet glycoprotein Ib-binding protein,
reveals a novel cyclic tetramer of C-type lectin-like heterodimers.
AB - Snake venom contains a number of the hemostatically active C-type lectin-like
proteins, which affect the interaction between von Willebrand factor (vWF) and
the platelet glycoprotein (GP) Ib or platelet receptor to inhibit/induce platelet
activation. Flavocetin-A (FL-A) is a high-molecular mass C-type lectin-like
protein (149 kDa) isolated from the habu snake venom. FL-A binds with high
affinity to the platelet GP Ibalpha-subunit and functions as a strong inhibitor
of vWF-dependent platelet aggregation. We have determined the X-ray crystal
structure of FL-A and refined to 2.5 A resolution. This is a first elucidation of
a three-dimensional structure of the platelet GP Ib-binding protein. The overall
structure reveals that the molecule is a novel cyclic tetramer (alphabeta)(4)
made up of four alphabeta-heterodimers related by a crystallographic 4-fold
symmetry. The tetramerization is mediated by an interchain disulfide bridge
between cysteine residues at the C-terminus of the alpha-subunit and at the N
terminus of the beta-subunit in the neighboring alphabeta-heterodimer. The high
affinity of FL-A for the platelet GP Ib alpha-subunit could be explained by a
cooperative-binding action through the multiple binding sites of the tetramer.
PMID- 10684641
TI - Crystallographic studies of the interactions of Escherichia coli lytic
transglycosylase Slt35 with peptidoglycan.
AB - Lytic transglycosylases catalyze the cleavage of the beta-1, 4-glycosidic bond
between N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) in
peptidoglycan with concomitant formation of a 1,6-anhydro bond in the MurNAc
residue. To understand the reaction mechanism of Escherichia coli lytic
transglycosylase Slt35, three crystal structures have been determined of Slt35 in
complex with two different peptidoglycan fragments and with the lytic
transglycosylase inhibitor bulgecin A. The complexes define four sugar-binding
subsites (-2, -1, +1, and +2) and two peptide-binding sites in a large cleft
close to Glu162. The Glu162 side chain is between the -1 and +1 sugar-binding
sites, in agreement with a function as catalytic acid/base. The complexes suggest
additional contributions to catalysis from Ser216 and Asn339, residues which are
conserved among the MltB/Slt35 lytic transglycosylases.
PMID- 10684642
TI - Ligand preference inferred from the structure of neutrophil gelatinase associated
lipocalin.
AB - Neutrophil gelatinase associated lipocalin (NGAL), a constituent of neutrophil
granules, is a member of the lipocalin family of binding proteins. NGAL can also
be highly induced in epithelial cells in both inflammatory and neoplastic
colorectal disease. NGAL is proposed to mediate inflammatory responses by
sequestering neutrophil chemoattractants, particularly N-formylated tripeptides
and possibly leukotriene B(4) and platelet activating factor. The crystal
structures of NGAL display a typical lipocalin fold, albeit with an unusually
large and atypically polar binding site, or calyx. The fold of NGAL is most
similar to the epididymal retinoic acid-binding protein, another lipocalin,
though the overall architecture of the calyces are very different. The crystal
structures also reveal either sulfate ions or an adventitiously copurified fatty
acid bound in the binding site. Neither ligand is displaced by added N-formylated
tripeptides. The size, shape, and character of the NGAL calyx, as well as the low
relative affinity for N-formylated tripeptides, suggest that neither the
copurified fatty acid nor any of the proposed ligands are likely to be the
preferred ligand of this protein. Comparisons between the crystal structures and
the recently reported solution structure of NGAL reveal significant differences,
in terms of both the details of the structure and the overall flexibility of the
fold.
PMID- 10684643
TI - The single mutation Phe173 --> Ala induces a molten globule-like state in murine
interleukin-6.
AB - A series of three aromatic to alanine mutants of recombinant murine interleukin-6
lacking the 22 N-terminal residues (DeltaN22mIL-6) were constructed to
investigate the role of these residues in the structure and function of mIL-6.
While Y78A and Y97A have activities similar to that of DeltaN22mIL-6, F173A lacks
biological activity. F173A retains high levels of secondary structure, as
determined by far-UV circular dichroism (CD), but has substantially reduced
levels of tertiary structure, as determined by near-UV CD and (1)H NMR
spectroscopy. F173A also binds the hydrophobic dye 1-anilino-8
naphthalenesulfonic acid (ANS) over a range of pH values and exhibits
noncooperative equilibrium unfolding (as judged by the noncoincidence of
monophasic unfolding transitions monitored by far-UV CD and lambda(max), with
midpoints of unfolding at 2.6 +/- 0. 1 and 3.5 +/- 0.3 M urea, respectively, and
the lack of an observable thermal unfolding transition). These are all properties
of molten globule states, suggesting that the loss of activity of F173A results
from the disruption of the fine structure of the protein, rather than from the
loss of a side chain that is important for ligand-receptor interactions.
Surprisingly, under some conditions, this loosened conformation is no more
susceptible to proteolytic attack than the parent protein. By analogy with human
IL-6, Phe173 in DeltaN22mIL-6 makes multiple interhelical interactions, the
removal of which appear to be sufficient to induce a molten globule-like
conformation.
PMID- 10684644
TI - Identification of functionally important amino acid residues within the C2-domain
of human factor V using alanine-scanning mutagenesis.
AB - We have previously determined that the C2-domain of human factor V (residues 2037
2196) is required for expression of cofactor activity and binding to
phosphatidylserine (PS)-containing membranes. Naturally occurring factor V
inhibitors and a monoclonal antibody (HV-1) recognized epitopes in the amino
terminus of the C2-domain (residues 2037-2087) and blocked PS binding. We have
now investigated the function of individual amino acids within the C2-domain
using charge to alanine mutagenesis. Charged residues located within the C2
domain were changed to alanine in clusters of 1-3 mutations per construct. In
addition, mutants W2063A, W2064A, (W2063, W2064)A, and L2116A were constructed as
well. The resultant 30 mutants were expressed in COS cells using a B-domain
deleted factor V construct (rHFV des B). All mutants were expressed efficiently
based on the polyclonal antibody ELISA. The charged residues, Arg(2074),
Asp(2098), Arg(2171), Arg(2174), and Glu(2189) are required for maintaining the
structural integrity of the C2-domain of factor V. Four of these residues
(Arg(2074), Asp(2098), Arg(2171), and Arg(2174)) correspond to positions in the
factor VIII C-type domains that have been identified as point mutations in
patients with hemophilia A. The epitope for the inhibitory monoclonal antibody HV
1 has been localized to Lys(2060) through Glu(2069) in the factor V C2-domain.
The epitope for the inhibitory monoclonal antibody 6A5 is composed of amino acids
His(2128) through Lys(2137). The PS-binding site in the factor V C2-domain
includes amino acid residues Trp(2063) and Trp(2064). This site overlaps with the
epitope for monoclonal antibody HV-1. These factor V C2-domain mutants should
provide valuable tools for further defining the molecular interactions
responsible for factor V binding to phospholipid membranes.
PMID- 10684645
TI - Substrate specificity of human methylpurine DNA N-glycosylase.
AB - The activity of human methylpurine DNA N-glycosylase (hMPG) for major substrates
was directly compared using two types of substrates, i.e., natural DNA and
synthetic oligonucleotides. By the use of ARP assay detecting abasic sites in
DNA, we first investigated the activity on the natural DNA substrates containing
methylpurines, ethenopurines, or hypoxanthine (Hx) prepared by the conventional
methods. After the treatment with hMPG, the amount of AP sites in methylated DNA
was much higher than that in DNA containing ethenopurines or Hx. The
oligodeoxynucleotide having a single 7-methylguanine (7-mG) was newly synthesized
in addition to 1, N(6)-ethenoadenine (epsilonA)-, Hx-, and 8-oxoguanine
containing oligonucleotides. 7-mG was effectively excised by hMPG, though it
might be less toxic than the other methylated bases with respect to mutagenesis
and cell killing. The kinetic study demonstrated that k(cat)/K(m) ratios of the
enzyme for epsilonA, Hx, and 7-mG were 2.5 x 10(-3), 1.4 x 10(-3), and 4 x 10(-4)
min(-1) nM(-1), respectively. The oligonucleotides containing epsilonA
effectively competed against 7-mG, while Hx substrates showed unexpectedly low
competition. Concerning the effect of the base opposite damage, hMPG much
preferred Hx.T to other Hx pairs, and epsilonA.C and epsilonA.A pairs were better
substrates than epsilonA.T.
PMID- 10684646
TI - p53 regulates caveolin gene transcription, cell cholesterol, and growth by a
novel mechanism.
AB - Transcription of the human caveolin gene, directed by a TATA-less promoter, is
downregulated in actively dividing cells during S-phase, together with free
cholesterol (FC) efflux. It is upregulated by medium low density lipoprotein FC
levels in quiescent cells. In this study, a common mechanism has been identified
to coordinate the growth- and FC-dependent expression of caveolin. In human skin
fibroblasts, transcription factors E2F/DP-1 and Sp1 bound to adjacent consensus
sites at -151 to -138 bp of the caveolin promoter DNA sequence in a complex
stabilized by tumor suppressor protein p53. Wild-type p53 also bound directly to
DNA to a caveolin promoter sequence containing two consensus half-sites (-292 to
283 bp and -273 to -264 bp) for this transcription factor. SREBP-1, previously
identified as a transcriptional regulator of caveolin expression in response to
FC, mediated its effect via the same E2F/Sp1 site. Overexpression of E2F or p53
increased E2F binding to the -148 to -141 bp site, increased FC efflux, and
inhibited cell division. The mutant protein p53(143V-->A) was inactive. Okadaic
acid, previously shown to inhibit growth, FC efflux, and caveolin expression,
inhibited E2F/Sp1 binding, while higher concentrations of extracellular FC
increased it. The present findings provide a molecular link between the cell
cycle and FC homeostatic effects of caveolin. These results also describe a novel
mechanism of action for p53 in a TATA-less gene promoter and provide further
evidence for a significant regulatory role for FC in cell cycle progression.
PMID- 10684647
TI - ATP-dependent dissociation of non-disulfide-linked aggregates of coagulation
factor VIII is a rate-limiting step for secretion.
AB - Deficiency in coagulation factor VIII leads to the bleeding disorder hemophilia
A. Previous studies demonstrated that factor VIII secretion is limited due to an
ATP-requiring step early in the secretory pathway. In this report, we identified
that this ATP-dependent rate-limiting step involves the dissociation of non
disulfide-linked aggregates within the endoplasmic reticulum (ER). In contrast to
the numerous examples of interchain disulfide-linked aggregates, factor VIII is
the first protein characterized to form non-disulfide-linked high molecular
weight aggregates within the ER. Approximately a third of newly synthesized
factor VIII was detected in high molecular weight aggregates. These aggregates
disappeared over time as functional factor VIII appeared in the medium. The
aggregated complexes did not require proteasomal degradation for clearance.
Aggregate formation was enhanced by ATP depletion, and upon restoration of
metabolic energy, these aggregates were dissociated and secreted. With the
coexpression of von Willebrand factor (vWF), a small portion of vWF coaggregated
with factor VIII. However, vWF dissociated from the aggregates more rapidly than
factor VIII, supporting that these aggregates are dynamic. An increase in the
factor VIII expression level elicited a corresponding increase in the fraction of
factor VIII that was aggregated. In addition, a 110 amino acid sequence
containing a hydrophobic beta-sheet within factor VIII was identified that may
predispose factor VIII to aggregation. These data show that formation and ATP
dependent dissolution of nondisulfide-linked factor VIII aggregates is a dynamic,
rate-limiting step during the folding process in the early secretory pathway. In
summary, we have identified an unprecedented requirement for protein transport
out of the ER that involves an ATP-dependent dissociation of non-disulfide-linked
aggregates within the ER.
PMID- 10684648
TI - Competition of annexin V and anticardiolipin antibodies for binding to
phosphatidylserine containing membranes.
AB - Annexin V, an intracellular protein with a calcium-dependent high affinity for
anionic phospholipid membranes, acts as an inhibitor of lipid-dependent reactions
of the blood coagulation. Antiphospholipid antibodies found in the plasma of
patients with antiphospholipid syndrome generally do not interact with
phospholipid membranes directly, but recognize (plasma) proteins associated with
lipid membranes, mostly prothrombin or beta(2)-glycoprotein I (beta(2)GPI).
Previously, it has been proposed that antiphospholipid antibodies may cause
thrombosis by displacing annexin V from procoagulant cell surfaces. We used
ellipsometry to study the binding of annexin V and of complexes of beta(2)GPI
with patient-derived IgG antibodies to beta(2)GPI, commonly referred to as
anticardiolipin antibodies (ACA), to phospholipid bilayers composed of
phosphatidylcholine (PC) and 20% phosphatidylserine (PS). More specifically, we
investigated the competition of these proteins for the binding sites at these
bilayers. We show that ACA-beta(2)GPI complexes, adsorbed to PSPC bilayers, are
displaced for more than 70% by annexin V and that annexin V binding is unaffected
by the presence of ACA-beta(2)GPI complexes. Conversely, annexin V preadsorbed to
these bilayers completely prevents adsorption of ACA-beta(2)GPI complexes, and
none of the preadsorbed annexin V is displaced by ACA-beta(2)GPI complexes. Using
ellipsometry, we also studied the effect of ACA-beta(2)GPI complexes on the
interaction of annexin V with the membranes of ionophore-activated blood
platelets as a more physiological relevant model of cell membranes. The
experiments with blood platelets confirm the high-affinity binding of annexin V
to these membranes and unequivocally show that annexin V binding is unaffected by
the presence of ACA-beta(2)GPI. In conclusion, our data unambiguously show that
ACA-beta(2)GPI complexes are unable to displace annexin V from procoagulant
membranes to any significant extent, whereas annexin V does displace the majority
of preadsorbed ACA-beta(2)GPI complexes from these membranes.
PMID- 10684649
TI - C-terminal domains of Na(+)/H(+) exchanger isoform 3 are involved in the basal
and serum-stimulated membrane trafficking of the exchanger.
AB - When expressed either in polarized epithelial cells or in fibroblasts, two
Na(+)/H(+) exchanger isoforms, NHE1 and NHE3, have different subcellular
distributions. Using a quantitative cell surface biotinylation technique, we
found PS120 cells target approximately 90% of mature NHE1 but only 14% of NHE3 to
the cell surface, and this pattern occurs irrespective of NHE protein expression
levels. In this study, we examined surface fractions of NHE3 C-terminal
truncation mutants to identify domains involved in the targeting of NHE3.
Removing the C-terminal 76 amino acids doubled surface fractions to 30% of total
and doubled the V(max) from 1300 to 2432 microM H(+)/s. Removal of another 66
amino acids increased surface levels to 55% of total with an increase in the
V(max) to 5794 microM H(+)/s. Surface fractions did not change with a further 105
amino acid truncation. We postulated that inhibition of the basal recycling of
NHE3 could result in the surface accumulation of the NHE3 truncations.
Accordingly, we found that, unlike wild-type NHE3, the truncations were shown to
internalize poorly and were not affected by PI3 kinase inhibition. However, while
the truncations demonstrated reduced basal recycling, they retained the same
serum response as full-length NHE3, with a mobilization of approximately 10% of
total NHE to the surface. We conclude that basal recycling of NHE3 is controlled
by endocytic determinants contained within its C-terminal 142 amino acids and
that serum-mediated exocytosis is independently regulated through a different
part of the protein.
PMID- 10684650
TI - Structure-activity relationships for the interaction of bovine pancreatic trypsin
inhibitor with an intracellular site on a large conductance Ca(2+)-activated K(+)
channel.
AB - Large conductance Ca(2+)-activated K(+) channels (BK(Ca)) contain an
intracellular binding site for bovine pancreatic trypsin inhibitor (BPTI), a well
known inhibitor of various serine proteinase (SerP) enzymes. To investigate the
structural basis of this interaction, we examined the activity of 11 BPTI mutants
using single BK(Ca) channels from rat skeletal muscle incorporated into planar
lipid bilayers. All of the mutants induced discrete substate events at the single
channel level. The dwell time of the substate, which is inversely related to the
dissociation rate constant of BPTI, exhibited relatively small changes (<9-fold)
for the various mutants. However, the apparent association rate constant varied
up to 190-fold and exhibited a positive correlation with the net charge of the
molecule, suggesting the presence of a negative electrostatic surface potential
in the vicinity of the binding site. The substate current level was unaffected by
most of the mutations except for substitutions of Lys15. Different residues at
this position were found to modulate the apparent conductance of the BPTI-induced
substate to 0% (K15G), 10% (K15F), 30% (K15 wild-type), and 55% (K15V) of the
open state at +20 mV. Lys15 is located on a loop of BPTI that forms the primary
contact region for binding to many SerPs such as trypsin, chymotrypsin, and
elastase. The finding that Lys15 is a determinant of the conductance behavior of
the BK(Ca) channel when BPTI is bound implies that the same inhibitory loop that
contacts SerP's is located close to the protein interface in the BK(Ca) channel
complex. This supports the hypothesis that the C-terminal region of the BK(Ca)
channel protein contains a domain homologous to SerP's. We propose a domain
interaction model for the mechanism of substate production by Kunitz inhibitors
based on current ideas for allosteric activation of BK(Ca) channels by voltage
and Ca(2+).
PMID- 10684651
TI - The Leishmania GDP-mannose transporter is an autonomous, multi-specific,
hexameric complex of LPG2 subunits.
AB - LPG2 (a gene involved in lipophosphoglycan assembly) encodes the Golgi GDP-Man
transporter of the protozoan parasite Leishmania and is a defining member of a
new family of eukaryotic nucleotide-sugar transporters (NSTs). Although NST
activities are widespread, mammalian cells lack a GDP-Man NST, thereby providing
an ideal heterologous system for probing the LPG2 structure and activity. LPG2
expression constructs introduced into either mammalian cells or a Leishmania
lpg2(-) mutant conferred GDP-Man, GDP-Ara, and GDP-Fuc (in Leishmania only)
uptake in isolated microsomes. LPG2 is the first NST to be associated with
multiple substrate specificities. Uptake activity showed latency, exhibited an
antiport mechanism of transport with GMP, and was susceptible to the anion
transport inhibitor DIDS. The apparent K(m) for GDP-Man uptake was similar in
transfected mammalian cells (12.2 microM) or Leishmania (6.9 microM). Given the
evolutionary distance between protozoans and vertebrates, these data suggest that
LPG2 functions autonomously to provide transporter activity. Using epitope-tagged
LPG2 proteins, we showed the existence of hexameric LPG2 complexes by
immunoprecipitation experiments, glycerol gradient centrifugation, pore-limited
native gel electrophoresis, and cross-linking experiments. This provides strong
biochemical evidence for a multimeric complex of NSTs, a finding with important
implications to the structure and specificity of NSTs in both Leishmania and
other organisms. Inhibition of essential GDP-Man uptake in fungal and protozoan
systems offers an attractive target for potential chemotherapy.
PMID- 10684652
TI - Cellular phosphorylation of an acidic proline-rich protein, PRP1, a secreted
salivary phosphoprotein.
AB - Phosphorylation of many secreted salivary proteins is necessary for their
biological functions. Identification of the kinase, which is responsible for in
vivo phosphorylation, is complicated, because several of the protein
phosphorylation sites conform both to the recognition sequence of casein kinase 2
(CK2) and Golgi kinase (G-CK), which both are found in the secretory pathway.
This study was undertaken to determine the kinase recognition sequence in a
secreted proline-rich salivary protein, PRP1, and thereby identify the
responsible kinase. This was done by transfecting a human submandibular cell
line, HSG, and a kidney cell line, HEK293, with expression vectors encoding wild
type or mutated PRP1. It was shown that phosphorylation occurred only at the same
sites, Ser8 and 22, as in PRP1 purified from saliva. Phosphorylation at either
site did not depend on the other site being phosphorylated. The sequence
surrounding Ser8 has characteristics of both CK2 and G-CK recognition sequences,
but destruction of the CK2 recognition site had no effect on phosphorylation,
whereas no phosphorylation occurred if the G-CK recognition sequence was altered.
The sequence surrounding Ser22 did not conform to any known kinase recognition
sites. If Ser22 was mutated to Thr, no phosphorylation was seen, and a cluster of
negatively charged residues at positions 27-29 was identified as part of the
enzyme recognition site. Ser22 may be phosphorylated by a G-CK that recognizes an
atypical substrate sequence or by a novel kinase. No difference in
phosphorylation was seen between undifferentiated and differentiated HSG cells.
PMID- 10684653
TI - Recovery of photosystem II activity in photoinhibited synechocystis cells: light
dependent translation activity is required besides light-independent synthesis of
the D1 protein.
AB - Irreversible photoinactivation of photosystem II (PSII) results in the
degradation of the reaction center II D1 protein. In Synechocystis PCC 6714
cells, recovery of PSII activity requires illumination. The rates of
photoinactivation and recovery of PSII activity in the light are similar in cells
grown in minimal (MM) or glucose-containing medium (GM). Reassembly of PSII with
newly synthesized proteins requires degradation of the D1 protein of the
photoinactivated PSII. This process may occur in darkness in both types of cells.
The degraded D1 protein is, however, only partially replaced by newly synthesized
protein in MM cells in darkness while a high level of D1 protein synthesis occurs
in darkness in the GM cells. The newly synthesized D1 protein in darkness appears
to be assembled with other PSII proteins. However, PSII activity is not recovered
in such cells. Illumination of the cells in absence but not in the presence of
protein synthesis inhibitors allows recovery of PSII activity.
PMID- 10684654
TI - Rebinding of IgE Fabs at haptenated planar membranes: measurement by total
internal reflection with fluorescence photobleaching recovery.
AB - In previous work, a general analytical theory for ligand rebinding at cell
surfaces was developed for a reversible bimolecular reaction between ligands in
solution and receptors on a membrane surface [Lagerholm, B. C., and Thompson, N.
L. (1998) Biophys. J. 74, 1215-1228]. This theory can be used to predict
theoretical forms for data obtained by using total internal reflection with
fluorescence photobleaching recovery (TIR-FPR) [Thompson, N. L., Burghardt, T.
P., and Axelrod, D. (1981) Biophys. J. 33, 435-454]. Thus, one method by which
the rebinding theory can be tested is to use TIR-FPR. In the work described
herein, the reversible kinetics of mouse monoclonal anti-dinitrophenyl (DNP) IgE
Fabs at substrate-supported planar membranes composed of 25 mol % DNP-conjugated
phosphatidylethanolamine and 75 mol % dipalmitoylphosphatidylcholine have been
examined by using TIR-FPR. Data were obtained as a function of the Fab solution
concentration. Higher Fab concentrations reduce rebinding (and increase the
fluorescence recovery rate) because different Fab molecules compete for the same
surface-binding sites. Data were also obtained for solutions containing different
volume fractions of glycerol. In these measurements, higher glycerol
concentrations increase rebinding (and decrease the fluorescence recovery rate)
because the solution viscosity is increased and the Fab diffusion coefficient in
solution is decreased. The TIR-FPR data were quantitatively compared with
theoretical predictions which follow from the general theory for rebinding at the
membrane surface. The data were consistent with the theoretical predictions and,
therefore, provide experimental verification of the previously developed theory.
PMID- 10684655
TI - From redox flow to gene regulation: role of the PrrC protein of Rhodobacter
sphaeroides 2.4.1.
AB - Activation of photosynthesis (PS) gene expression by the PrrBA two-component
activation system in Rhodobacter sphaeroides 2.4.1 results from the interruption
of an inhibitory signal originating from the cbb(3) cytochrome c oxidase via its
interaction with oxygen, in conjunction with the Rdx redox proteins. The CcoQ
protein, encoded by the ccoNOQP operon, which encodes the cbb(3) cytochrome c
oxidase, was shown to act as a "transponder" that conveys the signal derived from
reductant flow through cbb(3) to oxygen, to the Prr system. To further define the
elements comprising this signal transduction pathway we considered the prrC gene
product, which to date possessed no definable role in this signal transduction
pathway despite its being part of the prrBCA gene cluster. Similar to mutations
in cbb(3) and rdx, suitably constructed prrC deletion mutations lead to PS gene
expression in the presence of high oxygen. Unlike mutations that remove cbb(3)
terminal oxidase activity or Rdx function, the PrrC deletion mutant shows no
effect upon cbb(3) activity, nor does it affect the ratio of the carotenoid (Crt)
spheroidene (SE) to spheroidenone (SO). Thus, the PrrC deletion mutant behaves
identically to the CcoQ deletion mutant. Taking these and previous results
together, we suggest that PrrC is located upstream of the two-component PrrBA
activation system in the signal transduction pathway but downstream of the cbb(3)
cytochrome c oxidase and its "transponder" CcoQ. The PrrC deletion mutant was
also shown to lead to an increase in the DorA protein under aerobic conditions as
was shown earlier for the cbb(3) mutant. Finally, PrrC is a member of a highly
conserved family of proteins found in both prokaryotes and eukaryotes, and this
appears to be the first instance in which a direct regulatory role has been
ascribed to a member of this protein family.
PMID- 10684656
TI - A new photolabile precursor of glycine with improved properties: A tool for
chemical kinetic investigations of the glycine receptor.
AB - The synthesis and characterization of a new photolabile precursor of glycine
(caged glycine) is described. The alpha-carboxyl group of glycine is covalently
coupled to the alpha-carboxy-2-nitrobenzyl (alphaCNB) protecting group.
Photolysis of the caged glycine with UV light produces free glycine. At 308 nm,
the compound photolyzes with a quantum yield of 0.38. The absorption spectrum and
the pH dependence of a transient absorption produced after laser-flash
illumination are typical for aci-nitro intermediates of alphaCNB-protected
compounds. The time constant for the major component of the aci-nitro
intermediate decay ( approximately 84% of the total aci-nitro absorbance) was
determined to be 7 micros at physiological pH. A minor component ( approximately
16%) decays with a rate constant of 170 micros. The compound does not activate or
inhibit the alpha(1)-homomeric glycine receptor transiently expressed in HEK293
cells. After photolysis with a 10 ns pulse of 325 nm laser light, the glycine
released from the caged compound activates glycine-mediated whole-cell currents
in the same cells. The rise of these currents can be measured in a time-resolved
fashion and occurs on a millisecond to sub-millisecond time scale. It can be
described with a single-exponential function over >85% of the total current. The
rate constant of the current rise is about 2 orders of magnitude slower than the
rate constant of caged glycine photolysis. Thermal hydrolysis of the alphaCNB
caged glycine takes place with a half-life of 15.6 h at physiological pH. The new
caged glycine is the first in a series of photoprotected glycine derivatives that
has the required properties for use with chemical kinetic methods for
investigation of glycine-activated cell surface receptors. Photolysis is rapid
and efficient with respect to the receptor reactions to be studied; hydrolysis in
aqueous solution is sufficiently slow, and the compound is biologically inert. It
will, therefore, be a useful tool for investigation of the processes leading to
channel opening of glycine receptor channels and the effects of mutations of the
glycine receptor and of inhibitors on these processes.
PMID- 10684657
TI - Effects of aromatic residues at the ends of transmembrane alpha-helices on helix
interactions with lipid bilayers.
AB - We have studied the effects of aromatic residues at the ends of peptides of the
type Ac-KKGL(n)()WL(m)()KKA-amide on their interactions with lipid bilayers as a
function of lipid fatty acyl chain length, physical phase, and charge. Peptide Ac
KKGFL(6)WL(8)FKKA-amide (F(2)L(14)) incorporated into bilayers of
phosphatidylcholines containing monounsaturated fatty acyl chains of lengths C14
C24 at a peptide:lipid molar ratio of 1:100 in contrast to Ac-KKGL(7)WL(9)KKA
amide (L(16)) which did not incorporate at all into dierucoylphosphatidylcholine
[di(C24:1)PC]; Ac-KKGYL(6)WL(8)YKKA-amide (Y(2)L(14)) incorporated partly into
di(C24:1)PC. Lipid-binding constants relative to that for
dioleoylphosphatidylcholine (C18:1)PC were obtained using a fluorescence
quenching method. For Y(2)L(14) and F(2)L(14), relative lipid-binding constants
increased with increasing fatty acyl chain length from C14 to C24; strongest
binding did not occur at the point where the hydrophobic length of the peptide
equalled the hydrophobic thickness of the bilayer. For Ac-KKGYL(9)WL(11)YKKA
amide (Y(2)L(20)), increasing chain length from C18 to C24 had little effect on
relative binding constants. Anionic phospholipids bound more strongly than
zwitterionic phospholipids to Y(2)L(14) and Y(2)L(20) but effects of charge were
relatively small. In two phase (gel and liquid crystalline) mixtures, all the
peptides partitioned more strongly into liquid crystalline than gel phase;
effects were independent of the structure of the peptide or of the lipid
(dipalmitoylphosphatidylcholine or bovine brain sphingomyelin). Addition of
cholesterol had little effect on incorporation of the peptides into lipid
bilayers. It is concluded that the presence of aromatic residues at the ends of
transmembrane alpha-helices effectively buffers them against changes in bilayer
thickness caused either by an increase in the chain length of the phospholipid or
by the presence of cholesterol.
PMID- 10684658
TI - Kinetic mechanism of the p38-alpha MAP kinase: phosphoryl transfer to synthetic
peptides.
AB - p38 is a member of the mitogen-activated protein (MAP) kinase family. Activation
(phosphorylation) of p38 acts as a switch for the transcriptional and
translational regulation of a number of proteins, including the proinflammatory
cytokines. Investigation of a set of small peptides revealed that, as with
protein substrates, p38-alpha behaves as a proline-directed Ser/Thr MAP kinase
for a peptide substrate, peptide 4 (IPTSPITTTYFFFKKK). We investigated the steady
state kinetic mechanism of the p38-alpha-catalyzed kinase reaction with EGF
receptor peptide, peptide 1, as a substrate. Lineweaver-Burk analysis of the
substrate kinetics yielded a family of lines intersecting to the left of the
ordinate, with either ATP or peptide 1 as the varied substrate. Kinetic analysis
in the presence of ADP yielded a competitive inhibition pattern when ATP was the
varied substrate and a noncompetitive pattern if peptide 1 was the varied
substrate. At saturating peptide substrate concentrations, inhibition by
phosphopeptide product yielded an uncompetitive pattern when ATP was the varied
substrate. These data are consistent with ordered binding with ATP as the initial
substrate. We provide further evidence of the existence of a productive p38.ATP
binary complex in that (a) activated p38-alpha has intrinsic ATPase activity, (b)
ATPase and kinase activities are coupled, and (c) inhibitors of ATPase activity
also inhibit the kinase activity with a similar inhibition constant. The k(cat)
for the kinase reaction was lowered by 1.8-fold when ATP-gamma-S was used.
Microviscosity linearly affected the k(cat) values of both the ATP and ATP-gamma
S reactions with a slope of about 0.8. These observations were interpreted to
mean that the phosphoryl transfer step is not rate-limiting and that the release
of product and/or enzyme isomerization is a possible rate-limiting step(s).
PMID- 10684659
TI - Mechanistic analysis of a type II polyketide synthase. Role of conserved residues
in the beta-ketoacyl synthase-chain length factor heterodimer.
AB - Type II polyketide synthases (PKSs) are a family of multienzyme systems that
catalyze the biosynthesis of polyfunctional aromatic natural products such as
actinorhodin, frenolicin, tetracenomycin, and doxorubicin. A central component in
each of these systems is the beta-ketoacyl synthase-chain length factor (KS-CLF)
heterodimer. In the presence of an acyl carrier protein (ACP) and a malonyl
CoA:ACP malonyl transferase (MAT), this enzyme synthesizes a polyketide chain of
defined length from malonyl-CoA. We have investigated the role of the
actinorhodin KS-CLF in priming, elongation, and termination of its octaketide
product by subjecting the wild-type enzyme and selected mutants to assays that
probe key steps in the overall catalytic cycle. Under conditions reflecting
steady-state turnover of the PKS, a unique acyl-ACP intermediate is detected that
carries a long, possibly full-length, acyl chain. This species cannot be
synthesized by the C169S, H309A, K341A, and H346A mutants of the KS, all of which
are blocked in early steps in the PKS catalytic cycle. These four residues are
universally conserved in all known KSs. Malonyl-ACP alone is sufficient for
kinetically and stoichiometrically efficient synthesis of polyketides by the wild
type KS-CLF, but not by heterodimers that carry the mutations listed above. Among
these mutants, C169S is an efficient decarboxylase of malonyl-ACP, but the H309A,
K341A, and H346A mutants are unable to catalyze decarboxylation. Transfer of
label from [(14)C]malonyl-ACP to the nucleophile at position 169 in the KS can be
detected for the wild-type enzyme and for the C169S and K341A mutants, but not
for the H309A mutant and only very weakly for the H346A mutant. A model is
proposed for decarboxylative priming and extension of a polyketide chain by the
KS, where C169 and H346 form a catalytic dyad for acyl chain attachment, H309
positions the malonyl-ACP in the active site and supports carbanion formation by
interacting with the thioester carbonyl, and K341 enhances the rate of malonyl
ACP decarboxylation via electrostatic interaction. Our data also suggest that the
ACP and the KS dissociate after each C-C bond forming event, and that the newly
extended acyl chain is transferred back from the ACP pantetheine to the KS
cysteine before dissociation can occur. Chain termination is most likely the rate
limiting step in polyketide biosynthesis. Within the act CLF, neither the
universally conserved S145 residue nor Q171, which aligns with the active site
cysteine of the ketosynthase, is essential for PKS activity. The results
described here provide a basis for a better understanding of the catalytic cycle
of type II PKSs and fatty acid synthases.
PMID- 10684660
TI - tRNA 3' processing in plants: nuclear and mitochondrial activities differ.
AB - The nuclear tRNA 3' processing activity from wheat has been characterized and
partially purified. Several characteristics of the wheat nuclear 3' processing
enzyme now allow this activity to be distinguished from its mitochondrial
counterpart. The nuclear enzyme is an endonuclease, which we termed nuclear RNase
Z. The enzyme cleaves at the discriminator base and seems to consist only of
protein subunits, since essential RNA subunits could not be detected. RNase Z
leaves 5' terminal phosphoryl and 3' terminal hydroxyl groups at the processing
products. It is a stable enzyme being active over broad temperature and pH
ranges, with the highest activity at 35 degrees C and pH 8.4. The apparent
molecular mass according to gel filtration chromatography is 122 kDa. The nuclear
RNase Z does process 5' extended pretRNAs but with a much lower efficiency than
5' matured pretRNAs. Nuclear intron-containing precursor tRNAs as well as
mitochondrial precursor tRNAs are efficiently cleaved by the nuclear RNase Z.
Mitochondrial pretRNA(His) is processed by the nuclear RNase Z, generating a
mature tRNA(His) containing an 8 base pair acceptor stem. The edited
mitochondrial pretRNA(Phe) is cleaved easily, while the unedited version having a
mismatch in the acceptor stem is not cleaved. Thus, an intact acceptor stem seems
to be required for processing. Experiments with precursors containing mutated
tRNAs showed that a completely intact anticodon arm is not necessary for
processing by RNase Z. Comparison of the plant nuclear tRNA 3' processing enzyme
with the plant mitochondrial one suggests that both activities are different
enzymes.
PMID- 10684661
TI - Kinetic mechanism of nucleotide cofactor binding to Escherichia coli replicative
helicase DnaB protein. stopped-flow kinetic studies using fluorescent, ribose-,
and base-modified nucleotide analogues.
AB - The kinetic mechanism of binding nucleotide cofactors to the Escherichia coli
primary replicative helicase DnaB protein has been studied, using the
fluorescence stopped-flow technique. The experiments have been performed with
fluorescent ATP and ADP analogues bearing the modification on the ribose, MANT
AMP-PNP and MANT-ADP, and on the base, epsilonAMP-PNP and epsilonADP. Association
of the DnaB helicase with nucleotide cofactors is characterized by four
relaxation times that indicate that the binding occurs by a minimum of four
steps. The simplest mechanism which can describe the data is a four-step
sequential process where the bimolecular binding step is followed by three
isomerization steps. This mechanism is described by the following equation:
[equation in text]. The binding mechanism is independent of the location of the
nucleotide cofactor modification and is an intrinsic property of the DnaB
helicase-nucleotide system. Quantitative amplitude analyses, using the matrix
projection operator technique, allowed us to determine specific fluorescence
changes accompanying the formation of all intermediates relative to the
fluorescence of the free nucleotide. It shows that the major conformational
change of the DnaB helicase-nucleotide complex occurs in the formation of the (H
N)(1). Moreover, the value of the bimolecular rate constant, k(1), is 3-4 orders
of magnitude lower than the value expected for the diffusion-controlled reaction.
These results indicate that the determined first step includes formation of the
collision and an additional transition of the enzyme-nucleotide complex. The
obtained results provide evidence of profoundly different conformational states
of the ribose and base regions of the nucleotide-binding site in different
intermediates. The sequential nature of the mechanism of the nucleotide binding
to the DnaB helicase indicates the lack of the existence of a kinetically
significant conformational equilibrium of the helicase protomer and the DnaB
hexamer prior to the binding. The significance of these results for the
functioning of the DnaB helicase is discussed.
PMID- 10684663
TI - A cyclophilin-regulated PP2A-like protein phosphatase in thylakoid membranes of
plant chloroplasts
PMID- 10684664
TI - Electroviscous Forces on a Charged Cylinder Moving Near a Charged Wall.
AB - The refined theory of the electroviscous lift forces is presented for the case
when the separation distance between the particle and the wall is larger than the
double-layer thickness. The theory is based on the lubrication approximation for
motion of a long cylinder near a solid wall in creeping flow. The approximate
analytical formula for the lift force valid for Pe=1 is derived and compared
with the results of numerical calculations performed for an arbitrary Peclet
number. The resulting electrokinetic lift force exceeds by several orders of
magnitude one predicted by the previously developed theories of the lift force.
The results for the electroviscous drag force indicate that when the double layer
is thin compared with the particle size, the electroviscous drag is only a small
correction (at most 10%) to the hydrodynamic drag force acting on a neutral
particle moving near the wall. Copyright 2000 Academic Press.
PMID- 10684662
TI - Metabolism of 1alpha,25-dihydroxyvitamin D(3) in vitamin D receptor-ablated mice
in vivo.
AB - The metabolism of 1alpha,25-dihydroxyvitamin D(3) was studied in vitamin D
receptor-ablated mice following the administration of a physiological dose of
1alpha,25-dihydroxy-[26,27-(3)H]vitamin D(3). The degradation of 1alpha,25
dihydroxy-[26,27-(3)H]vitamin D(3) in the vitamin D receptor null mutant mice was
substantially reduced compared to the wild-type control mice. At 24 h
postadministration of radiolabeled 1alpha,25-dihydroxyvitamin D(3) more than 50%
of the radioactivity was recovered unmetabolized, whereas in wild-type mice
nearly all of the 1alpha,25-dihydroxy-[26,27-(3)H]vitamin D(3) was degraded. In
wild-type mice three polar metabolites other than 1alpha,25-dihydroxyvitamin D(3)
were detected and identified on straight-phase and reverse-phase high-performance
liquid chromatography as 1alpha,24(R),25-trihydroxy-[26,27-(3)H]vitamin D(3),
1alpha,25(S),26-trihydroxy-[26,27-(3)H]vitamin D(3), and (23S, 25R)-1alpha,25
dihydroxy-[(3)H]vitamin D(3)-26,23-lactone. Only one metabolite was detected in
the plasma and kidneys of vitamin D receptor null mutant mice at 3 h following an
intrajugular dose of 1alpha,25-dihydroxy-[26,27-(3)H]vitamin D(3). This
metabolite was clearly identified as 1alpha,25(S),26-trihydroxy-[26,27
(3)H]vitamin D(3) by comigration on two HPLC systems and periodate cleavage
reaction. At 6, 12, and 24 h postinjection 1alpha,24(R), 25-trihydroxy-[26,27
(3)H]vitamin D(3) was also detected at low levels in plasma, kidneys, and liver
of some but not all mutant mice. The presence of 25-hydroxyvitamin D(3)-24
hydroxylase mRNA in the kidneys of these vitamin D receptor null mutant mice was
confirmed by ribonuclease protection assay.
PMID- 10684665
TI - Anatase-Rutile Transition of Precipitated Titanium Oxide with Alcohol Rinsing.
AB - The effect of alcohol washing on the anatase-rutile transition of precipitated
titanium oxide was investigated using X-ray powder diffraction, Fourier-transform
IR spectroscopy, and thermogravimetry. Alcohol (butanol) rinsing accelerated the
anatase-rutile transition of precipitated titanium oxide powder so that the onset
temperature of transition decreased drastically from 800 degrees C for water
washed powder to 550 degrees C for alcohol-rinsed powder. Alternation of
transition kinetics and mechanisms by rinsing media could be confirmed from the
analysis of temperature and time dependence of rutile content. The
attributability of the chemical state of anatase after crystallization, which
contained H(2)O, OH, and organic residues, to the change of transition kinetics
with alcohol rinsing will be discussed. Two mechanisms, the effect of residual
organics and/or H(2)O(OH), could be suggested on the basis of analysis of the
difference between chemical states of water-washed anatase and alcohol-rinsed
powder. Copyright 2000 Academic Press.
PMID- 10684666
TI - Dynamic Mobility of Two Spherical Particles with Thick Double Layers.
AB - The dynamic electrophoretic mobility of a pair of nearby spherical particles is
analyzed in the case when the thickness of the electrical double layer around
each particle is comparable to the particle radius. By means of an integral
reciprocal relation, a formal expression is obtained for the force and torque on
N spheres subject to an oscillating electric field which may be spatially
varying. Upon linearizing in the surface potential, this expression is shown to
depend upon a set of purely hydrodynamic problems involving N neutral spheres,
the calculation of the electric field around N neutral spheres, and the
equilibrium charge distribution around N charged spheres. In the case of a single
particle, the known analytic formula for the dynamic mobility is recovered. For a
pair of identical particles, the dynamic mobility is calculated numerically,
using known solutions to the required subproblems. An analytical expression for
the mobility of a pair of widely separated spheres is also obtained by a method
of reflections, and this is in excellent agreement with the numerical results
outside the range of double layer overlap. Copyright 2000 Academic Press.
PMID- 10684667
TI - Dynamic Mobility of Particles with Thick Double Layers in a Nondilute Suspension.
AB - The dynamic mobility of a nondilute suspension of spherical particles is
investigated in the case where the thickness of the electrical double layer
around each particle is comparable to the particle radius. A formula is obtained
for the O(φ) correction in a random suspension of particles with volume
fraction φ, involving an integral over the dynamic mobility of a pair of
spheres. This formula is then evaluated using both analytical approximations and
numerical results previously obtained for the pair mobilities and valid for low
surface potentials. The effect of double-layer thickness on the O(φ)
coefficient is most pronounced at low frequencies, and lessens once the
hydrodynamic penetration depth is smaller than the particle radius. Various
approximations are considered that use the O(φ) result to predict the dynamic
mobility in concentrated suspensions, and at high frequencies these
approximations are shown to give results qualitatively different from those of
recent cell models. Copyright 2000 Academic Press.
PMID- 10684668
TI - Nonequilibrium Statistical Thermodynamics of Interfaces.
AB - Using Zubarev's theory of the operator, nonequilibrium linear quasithermodynamics
is presented. Laws connecting generalized fluxes with generalized forces are
formulated. The components of the kinetic transfer coefficients are determined.
These are rank 0-4 tensors. Copyright 2000 Academic Press.
PMID- 10684669
TI - Analysis of Thermally Stimulated Depolarization Currents (TSDC) Measured on
Exchanged Clays.
AB - This work shows that hydration of clays can be studied by means of a new
interpretation of thermally stimulated depolarization currents technique. These
measurements have been performed on four exchanged natural clays: Na
montmorillonite, Ca-montmorillonite, kaolinite, and illite. The results are
analyzed using both the recently developed analysis of relaxation times
distribution and the electronegativity equalization method. They provide evidence
of the surface heterogeneity of clays. It is established that sites, identical
from a crystallographic point of view, are different when the energy of the
phenomenon is considered. The main interest of this work is to give for the first
time a value of the hydration energy of cation onto clay surfaces. Copyright 2000
Academic Press.
PMID- 10684670
TI - Investigation of Structure and Growth of Self-Assembled Polyelectrolyte Layers by
X-ray and Neutron Scattering under Grazing Angles.
AB - The structure of self-assembled polyelectrolyte thin films on float glass has
been investigated by interface sensitive X-ray and neutron scattering methods.
Special emphazis was given to the adsorption process of poly (ethylene imine) and
polystyrole sulfonate as an important model system which is often used as a basis
for subsequent multilayer buildup. From complementary X-ray and neutron
reflectivity data, the vertical film density profile was derived for various
growth parameters, including kinetic effects of different adsorption times. In
addition to specular reflectivity, we have for the first time employed
nonspecular X-ray scattering to study lateral structure parameters in self
assembled polyelectrolyte films. Furthermore, the technique of time-resolved in
situ X-ray reflectivity during film growth has been demonstrated and is discussed
in view of its future potential. Copyright 2000 Academic Press.
PMID- 10684671
TI - Sorption of Cs(I) on Magnetite in the Presence of Silicates.
AB - The sorption of H(4)SiO(4) on magnetite has been qualified and quantified using
three different surface complexation models, CCM, DLM, and NEM. The three tested
models can account for the sorption of silicates using the same stoichiometry,
one neutral species binding on a neutral surface, and the same constant, error
aside. Experiments have also been performed to demonstrate that the sorption of
dissolved silicates has a nonnegligible effect on the behavior of the surface of
magnetite. Then, the sorption of cesium is insignificant on the neat surface of
magnetite and is increased up to 10-20% when silicates are present in solution. A
theoretical model, where the rule of electrostatics is pointed out, has been
developed to account for the experimental observations. This model allows the
reproduction of the sorption of cesium in the presence of dissolved silicates for
the following four cases: -concentration of silicates under solubility limit
concentration of silicates over solubility limit -binary mixtures of silica and
magnetite -natural magnetite with silica as impurity. The reaction given in the
model to account for the experimental observations proposes that silicates may
act as a "bridge" between the surface of magnetite and cesium. Copyright 2000
Academic Press.
PMID- 10684672
TI - Adsorption-Desorption Flow of Condensable Vapors through Mesoporous Media:
Network Modeling and Percolation Theory.
AB - Flow of condensable vapors in mesoporous media is investigated theoretically and
experimentally during adsorption and desorption processes. A typical permeability
curve of a condensable vapor is strongly enhanced in the capillary condensation
region. This is because additional capillary pressure gradients are imposed on
the capillary-condensed pores, which act as "good" conductors compared to the
noncondensed pores, which are considered "poor" conductors. The percolation
scaling properties that hold for a system of "good" and "poor" conductors are
confirmed for the cases examined. As the ratio of gas flow/capillary-enhanced
flow decreases, the rise of permeability with pressure becomes sharper. The
network connectivity has a strong impact on the maximum permeability value and on
the width of the scaling law regions. The contribution of surface flow does not
affect the permeability in the peak region, but results in a shrinkage of the
scaling law regions. During desorption, a marked hysteresis in the permeability
curves is found and it is attributed only to thermodynamic hysteresis. The
maximum permeability values in this case are higher and shifted to lower relative
pressures. Copyright 2000 Academic Press.
PMID- 10684673
TI - Stabilization of High Ionic Strength Slurries Using the Synergistic Effects of a
Mixed Surfactant System.
AB - The stability of colloidal slurries is an important parameter in many industries
due to problems that can arise as a result of particle settling. Particle
settling is often caused by the shielding of surface charges on the particles
which otherwise would prevent coagulation and subsequent settling. This is
particularly a problem in high ionic strength slurries, where large amounts of
ions serve to enhance the charge shielding and compression of the electrical
double layer around the particles. This phenomenon has been investigated for
industrially significant slurries used for tungsten and copper chemical
mechanical polishing (CMP). It has been found that the effects of addition of
conventional stabilizing agents (e.g., ionic surfactants, polymers) to these high
ionic strength slurries are neutralized by the electrolytes in solution. However,
the synergistic combination of a properly chosen ionic and nonionic surfactant
has been found to be a suitable stabilizing agent for this type of system. For
the CMP slurries investigated, the synergistic effect has been shown to be
maximum for combinations of sodium dodecyl sulfate anionic surfactant and a
variety of polymeric nonionic surfactants. The stabilization observed for these
mixed surfactant systems has been explained in terms of adsorption of ionic
surfactant on particle surfaces and nonionic surfactant molecules penetrating the
film of the ionic surfactant due to hydrocarbon chain interactions. This brings
about the steric stabilization of the slurry. Copyright 2000 Academic Press.
PMID- 10684674
TI - Surface Properties of Mesoporous Carbon-Silica Gel Adsorbents.
AB - Carbon/silica (carbosil) samples prepared utilizing mesoporous silica gel (Si-60)
modified by methylene chloride pyrolysis were studied by nitrogen adsorption,
quasi-isothermal thermogravimetry, p-nitrophenol adsorption from aqueous
solution, and (1)H NMR methods. The structural characteristics and other
properties of carbosils depend markedly on the synthetic conditions and the
amount of carbon deposited. The changes in the pore size distribution with
increasing carbon concentration suggest grafting of carbon mainly in pores,
leading to diminution of the mesopore radii. However, heating pure silica gel at
the pyrolysis temperature of 550 degrees C leads to an increase in the pore
radii. The quasi-isothermal thermogravimetry and (1)H NMR spectroscopy methods
used to investigate the water layers on carbosils showed a significant capability
of carbosils to adsorb water despite a relatively large content of the
hydrophobic carbon deposit, which represents a nonuniform layer incompletely
covering the oxide surface. Copyright 2000 Academic Press.
PMID- 10684675
TI - An Experimental Study of the Influence of Weak Convection on Perikinetic
Coagulation.
AB - A remarkably increased coagulation rate for 2-um PS spheres was previously
reported for a perikinetic coagulation experiment performed under microgravity
conditions (1998, R. Folkersma, A. J. G. van Diemen, and H. N. Stein, J. Colloid
Interface Sci. 206, 482); from this experiment, it was assumed that the leading
factor slowing the coagulation process under normal gravitation was free
convection due to gravity (1998, R. Folkersma, and H. N. Stein, J. Colloid
Interface Sci. 206, 494). To test the influence of free convection as a single
effect factor on the coagulation process, a ground-based experiment was
constructed. The coagulation rate of 2-um PS spheres dispersed in water was
determined by measuring the turbidity of the dispersion solution while convection
driven flows in the solution were checked with a visual magnification system. We
found that it was possible to cease free convection-driven particle flows on the
ground, as long as the experiments were carefully operated. The strength of
convection was controlled by changing the temperature gradient applied to the
sample cell. By monitoring both the coagulation rate and convection-driven flows
simultaneously, our experiments showed that weak free convection (maximum speed
<150 um/s) actually has negligible effects on the coagulation rate. Copyright
2000 Academic Press.
PMID- 10684676
TI - A Simple Model Incorporating the Effects of Deformation and Asperities into the
van der Waals Force for Macroscopic Spherical Solid Particles.
AB - The van der Waals interaction between perfectly spherical, infinitely hard
spheres is well understood. Unfortunately, real powder particles are not
infinitely hard and rarely spherical. Those particles that are approximately
spherical are often covered in small asperities. It is often believed that the
size of these asperities dominates the cohesive force between powder particles.
This paper rigorously examines this phenomenon and demonstrates the regimes over
which the asperities dominate the cohesive force and when the particle size
dominates. Deformation of particles is also investigated with a simple model and
is shown to produce a significant increase in cohesive force. We demonstrate that
previous simple models for calculating the effect of deformation are inadequate,
as they ignore effects that can be as large as the correction they suggest. This
can lead to an underestimation of the cohesive force by a factor of approximately
2. Copyright 2000 Academic Press.
PMID- 10684677
TI - Small-Angle X-Ray Scattering Studies on Nucleation Formation of Dextran
Precipitation in the Presence of Boron.
AB - In the present study, the nucleation formation process of dextran precipitation
in the presence of boron was investigated by small-angle X-ray scattering (SAXS)
techniques. The formation mechanism of aggregates or nuclei is very important in
the initial step of crystallization. SAXS measurement is an excellent technique
for observing these processes. The results of SAXS measurement suggest that
boron, as a trace impurity, induces the aggregating of dextran molecules
intermolecularly as a process in the nucleation formation of dextran precipitate
nuclei and causes precipitation of dextran through an elongation process. These
reactions occur readily at low boron concentrations. In fact, boron, which was
detected at low levels in dextran solutions, was concentrated in the
precipitates. Therefore, an aqueous solution of boron-free dextran should be
resistant to precipitation. Copyright 2000 Academic Press.
PMID- 10684678
TI - Proliferative enteropathy.
PMID- 10684679
TI - Study of the virulence of five strains of amyxomatous myxoma virus in crossbred
New Zealand White/Californian conventional rabbits, with evidence of long-term
testicular infection in recovered animals.
AB - The virulence of five amyxomatous myxoma virus (MV) strains, the clinical and
pathogenetic effects of which had been studied previously in specific pathogen
free (SPF) rabbits, was determined by inoculation of five groups of 10 crossbred
New Zealand White/Californian conventional rabbits. A much more acute myxomatosis
syndrome was produced in conventional rabbits than that reproduced previously in
SPF animals. However, the main clinical signs were of the respiratory type. The
MV strains MYX 254/95 and 801 appeared very virulent, killing all the inoculated
animals. The strains MYX 217/95, MYX 555/94 and Saint Benoist were somewhat
attenuated, killing only seven, six and six rabbits, respectively. Extensive lung
lesions due to supervening bacterial infections were observed in 36 of the 39
rabbits that died. Lethality was found to be a better estimate of virulence than
mean survival time. By 98 days after viral inoculation, all the surviving animals
had completely recovered. At that time, they were immunosuppressed by treatment
with adrenocorticotrophic hormone (ACTH) for 10 days to determine whether they
still harboured the virus. After the ACTH treatment, eight of the 11 surviving
rabbits showed clinical signs that resembled amyxomatous myxomatosis. All the
virological examinations performed on naso-conjunctival exudate, on mononuclear
cells, on eyelids and on ovaries remained negative but infectious virus was
isolated from the testes of three of six surviving male rabbits.
PMID- 10684680
TI - The efficacy of two vaccination schemes against experimental infection with a
virulent amyxomatous or a virulent nodular myxoma virus strain.
AB - Two types of myxomatosis vaccine are available commercially, namely, vaccine
prepared from the Shope fibroma virus (SFV) and that prepared from an attenuated
myxoma virus (MV) strain, e.gSG33. An experiment was designed to compare two
vaccination schemes for their ability to protect rabbits against challenge with
either a virulent amyxomatous MV strain or a virulent nodular MV strain. Apart
from a difference in the cutaneous expression of the disease, the two challenge
strains resembled each other in respect of mortality rate, naso-conjunctival
shedding of virus, and tissue infection. Vaccination with SFV alone failed to
prevent clinical signs, naso-conjunctival shedding or tissue infection.
Vaccination with SFV followed by a booster inoculation with SG33 protected
rabbits against the development of clinical signs and significantly reduced both
viral shedding in naso-conjunctival exudates and viral infection of eyelids,
lungs and testes; virus was, however, isolated from testes of some surviving
animals.
PMID- 10684681
TI - Characteristics of prion protein (PrP(Sc)) in the brains of hamsters inoculated
serially with a mouse-passaged scrapie strain.
AB - Syrian hamsters were inoculated intracerebrally with a mouse-passaged scrapie
strain. After serial passage, the incubation period decreased, but the vacuolar
lesion profiles remained unchanged. In immunoblot analysis, accumulated prion
protein (PrP) showed hamster PrP characteristics from the first passage. However,
immunohistochemical examination revealed a changing pattern of accumulated PrP
with each passage. In particular, there were many PrP plaques in the subpial and
subependymal region at the third passage, no such plaques having been observed in
the same region at the first passage. These results suggest that the species
barrier influences not only the incubation period but also the pattern of
accumulation of PrP in affected brains.
PMID- 10684682
TI - The neuropathology of experimental bovine spongiform encephalopathy in the pig.
AB - In an experimental study of the transmissibility of BSE to the pig, seven of 10
pigs, infected at 1-2 weeks of age by multiple-route parenteral inoculation with
a homogenate of bovine brain from natural BSE cases developed lesions typical of
spongiform encephalopathy. The lesions consisted principally of severe neuropil
vacuolation affecting most areas of the brain, but mainly the forebrain. In
addition, some vacuolar change was identified in the rostral colliculi and
hypothalamic areas of normal control pigs. PrP accumulations were detected
immunocytochemically in the brains of BSE-infected animals. PrP accumulation was
sparse in many areas and its density was not obviously related to the degree of
vacuolation. The patterns of PrP immunolabelling in control pigs differed
strikingly from those in the infected animals.
PMID- 10684683
TI - Equine macrophage identification with an antibody (Ki-M6) to human CD68 and a new
monoclonal antibody (JB10).
AB - Monoclonal antibodies (mAbs) recognizing equine macrophages are scarce. The
present study compared the immunocytochemical staining of various equine tissues
(lymphoid tissue, lung, liver, small intestine, skin and blood leucocytes) by an
antibody, Ki-M6, which detects CD68 in human macrophages and dendritic cells, and
by a new anti-equine mAb, JB10, with staining produced by two previously
described anti-equine macrophage mAbs, CZ2.2 and CZ3.3. Ki-M6 was shown to
identify equine macrophages, which had a distribution different from those
identified by CZ2.2 and CZ3.3. JB10 identified equine macrophages with a
distribution similar to those identified by Ki-M6, but additionally bound to
polymorphonuclear leucocytes. Flow cytometry of peripheral blood leucocyte
subpopulations and tissue immunocytochemistry were used to compare staining by
JB10 with that of CZ2.2 and CVS19; the latter identifies the myeloid antigen,
EqCD13, found on polymorphonuclear leucocytes. The staining by JB10 differed from
that of both CZ2.2 and CVS19, suggesting that JB10 detects a different molecule.
These additional mAbs should prove useful for the future study of new, defined,
populations of macrophages in equine immune responses and pathology, and, in the
case of Ki-M6 antibody, may make possible an analysis of the structure,
distribution and function of the CD68 molecule in the horse.
PMID- 10684684
TI - Enzyme-histochemical detection of a chymase-like proteinase within bovine mucosal
and connective tissue mast cells.
AB - The presence of chymase-like proteinase in bovine mast cells was investigated by
an enzyme-histochemical technique (naphthol-AS-D-chloroacetate as substrate) in
normal skin, primary bronchus, lung and duodenum. The counts and distribution of
chymase-positive and toluidine blue-positive mast cells were compared by means of
successive staining. Mast cells with chymase-like activity were detected in all
areas, but their proportion was greater in connective than mucosal tissues, with
the exception of the skin. These results contrast with those obtained in rodents,
in which chymase-like proteinases are detected in all tissues and also in all
mast cells. Bovine mast cells are closer to those of human beings, in which
chymase-containing mast cells predominate in connective tissues, including skin.
The results suggest that more than one chymase subset is present, at least in
duodenum. The possible occurrence of dual-specific chymase mast cells, as in
other ruminants, is discussed.
PMID- 10684685
TI - An immunohistochemical study of histiocytic ulcerative colitis in boxer dogs.
AB - Histiocytic ulcerative colitis (HUC) is an inflammatory bowel disease (IBD) that
occurs predominantly in dogs of the boxer breed. The lesions are characterized by
mucosal ulceration and mixed inflammatory cell infiltrate that includes the
presence of periodic acid-Schiff (PAS)-positive macrophages. However, the
phenotype of the inflammatory cells has not been characterized further. In the
present study, immunohistochemistry and computer-aided morphometric analysis were
used to define populations of leucocyte subsets in the colon of 14 boxer dogs
with HUC. Biopsies from six of these dogs included both lesional and non-lesional
regions. Colonic tissue from 11 dogs of various breeds without evidence of
gastrointestinal disease served as controls. In HUC lesions there were
significantly more IgG(+), IgG3(+), IgG4(+)plasma cells, CD3(+)T cells, MHC class
II(+)cells, L1(+)cells and PAS(+)cells in the lamina propria than in both control
colon and non-lesional colonic regions of affected dogs. In the epithelial
compartment, goblet cells were significantly decreased in HUC lesions compared to
both control and non-lesional HUC colon, and intensity of enterocyte MHC class II
expression was significantly increased. These observations are similar to those
documented in human IBD, especially ulcerative colitis, and suggest an important
role for the mucosal immune system in the pathogenesis of canine HUC.
PMID- 10684686
TI - Leucocyte entry and endothelial E-selectin expression following intradermal
Propionibacterium acnes administration.
AB - Immune responses in porcine skin to intradermal inoculation of heat-killed
Propionibacterium acnes (HKPA), the major bacterial agent associated with human
inflammatory acne, were studied. Pigs were chosen as experimental animals because
their skin is similar in structure and composition to that of man and because the
use of genetically inbred pigs enables leucocytes to be transferred between
animals without eliciting rejection responses. Two pigs were sensitized
intradermally with 10 mg of HKPA and were challenged 2 weeks later with doses
ranging from 1-100 microg of HKPA in various intradermal sites on the ventral
aspect of the abdomen. Four further pigs, previously sensitized with Bacillus
Calmette-Guerin (BCG) but not HKPA, were challenged with purified protein
derivative (PPD) of bovine tuberculin and HKPA. Entry of(51)Cr-labelled
peripheral blood lymphocytes (PBLs) over 48 h was studied in all the challenge
sites. Peak PBL entry occurred at 4 h, remaining sustained up to 24 h. There was
a dose-dependent effect of HKPA on the level of PBL entry, which was antigen
specific, as few leucocytes were seen in PPD-challenge sites in HKPA-sensitized
pigs or in HKPA-challenged sites in BCG-sensitized pigs. There was also a
substantial influx of(111)Indium-labelled neutrophils into the lesions.
Lymphocytes present were predominantly of the CD3(+)CD2(+)T-cell subset, although
gammadelta TCR(+)cells were present also, particularly after 24 h. E-selectin was
markedly upregulated on dermal endothelium in the P. acnes sites. The
histological infiltration and kinetics were similar to those reported in human
inflammatory acne.
PMID- 10684687
TI - Pneumonia induced byEndobronchial inoculation of calves with bovine herpesvirus
1.
AB - Each of six calves inoculated endobronchially with bovine herpesvirus 1 (BHV-1)
by means of a bronchoscope developed viral pneumonia. Gross and histopathological
lesions were mainly localized to the right diaphragmatic lobe (middle to caudal
region) of the lung and were closely associated with the site of the deposition
of the inoculum. The lesions were characterized by intranuclear inclusion bodies
associated with focal necrosis of the epithelium in the lower respiratory tract.
BHV-1 antigen and BHV particles were detected in the degenerating bronchial,
bronchiolar and alveolar epithelial cells. After infection, the total cell count
in the broncho-alveolar lavage (BAL) fluid increased. In addition, BHV-1 antigen
and virus were detected in the desquamated cells and macrophages of BAL fluid
from the right diaphragmatic lobe, but not from the left diaphragmatic lobe. It
is concluded that examination of BAL fluid is valuable for
immunohistopathological and virological confirmation of BHV-1 infection.
PMID- 10684688
TI - Sarcina -like bacteria, Clostridium fallax and Clostridium sordellii in lambs
with abomasal bloat, haemorrhage and ulcers.
AB - A study of abomasal disease in lambs aged 2-5 weeks, made during the period 1993
1998, included 67 cases and 45 non-affected controls. Gross pathological findings
included various combinations of bloat, haemorrhage and ulcers in the abomasum.
Sarcina -like bacteria were found in sections and smears from the abomasum of 79%
(53/67) of the cases. From one case, a lamb with abomasal bloat, the anaerobic
"packet"-forming Sarcina ventriculi was cultivated from the abomasal contents and
identified by biochemical reactions and sequencing of the 16S rRNA gene. Sarcina
like bacteria were observed microscopically in specimens from 94% (44/47) of the
lambs with abomasal gas and in 45% (9/20) of those with ulcers or haemorrhage or
both but little gas. On culture, abomasal contents from 41 cases yielded
Clostridium fallax from 16 (39%) and Clostridium sordellii from eight (20%);
abomasal cultures from 30 control lambs were negative for the three bacterial
species. Quantitative cultivation, carried out on abomasal contents from live
lambs and lambs dead =3 h, showed that Clostridium perfringens, Escherichia
coli and Lactobacillus spp. were present in the majority of both cases and
controls, with no significant differences in the mean numbers.
PMID- 10684689
TI - Experimental hendra virus infectionin pregnant guinea-pigs and fruit Bats
(Pteropus poliocephalus).
AB - Antibodies to Hendra virus (HeV) have been found in a high percentage of fruit
bats (Pteropus spp.) in Australia, indicating a possible reservoir for the virus.
The aim of the experiments reported here was to investigate transplacental
infection as a possible mode of transmission of the virus in fruit bats and other
animals. In a first experiment, 18 pregnant guinea-pigs in the mid-stage of
gestation were inoculated with HeV, as an experimental model in a conventional
laboratory animal. Nine developed HeV disease as confirmed by viral isolation,
histopathology and immunohistochemistry. In five of the nine clinically affected
guinea-pigs there was necrosis and strong positive immunostaining in the
placentas in an indirect immunoperoxidase (IPX) test for HeV antigen. One of
these five guinea-pigs aborted and HeV was isolated from its three fetuses, one
of which was also positive to the IPX test. In three other sick guinea-pig dams,
virus was isolated from fetuses, and there was positive immunostaining in two of
the latter. In a second experiment, four fruit bats were inoculated with a
similar dose of HeV. (A further four guinea-pigs inoculated at the same time
developed severe disease, indicating adequate virulence.) Two bats were killed at
10 days post-inoculation and two were killed at 21 days. In these bats, no overt
clinical disease was observed, but subclinical disease occurred, as indicated by
viral isolation, seroconversion, vascular lesions and positive immunostaining.
Transplacental transmission was indicated by positive immunostaining in two
placentas and confirmed by isolation of virus from one of the associated fetuses.
PMID- 10684690
TI - Fibrillary glomerulonephritis and pulmonary haemorrhage in a Woolly monkey
(Lagothrix lagotricha).
AB - Fibrillar deposits, distinct from amyloid deposits, were demonstrated by electron
microscopy in the glomeruli and lung of an Amazonian Woolly monkey (Lagothrix
lagotricha) which had died with extensive pulmonary haemorrhage. The renal
lesions were typical of fibrillary glomerulonephritis in man, and IgG deposition
was also demonstrated in the kidney. The association of renal and pulmonary
lesions has been reported previously in man, but this is the first report of
fibrillary glomerulonephritis, and a pulmonary-renal syndrome, in non-human
animals.
PMID- 10684691
TI - Decreased lipid fluidity of the erythrocyte membrane in dogs with leishmaniasis
associated anaemia.
AB - In both man and the dog, anaemia resulting from natural leishmaniasis is often
severe and mainly associated with a shortened life span of erythrocytes. Lipid
fluidity of erythrocyte membranes from 17 dogs with anaemia caused by visceral
leishmaniasis was investigated by means of fluorescence polarization. Results
were compared with those from three groups of control animals (10 healthy dogs,
seven dogs with visceral leishmaniasis but no anaemia, and 10 dogs with anaemia
unrelated to leishmaniasis). Fluorescence polarization values recorded for
animals with leishmaniasis-associated anaemia were elevated-indicating reduced
erythrocyte membrane fluidity-and significantly higher than in the control
groups. Mechanical sequestration by the spleen due to increased cell rigidity, or
alterations in receptor/ligand erythrocyte cytoadherence mechanisms, or both, may
result from decreased membrane fluidity and hence contribute to the anaemia of
Leishmania -infected dogs.
PMID- 10684692
TI - Isolation of Actinobacillus seminis from the genital tract of rams in spain.
AB - Actinobacillus seminis isolates were cultured from the semen (two isolates) and
the left testis (one isolate) of two one-year-old rams in Leon, Spain. One animal
showed lesions of chronic unilateral orchitis and epididymitis while the other
appeared to suffer a subclinical infection and only a moderate number of
pleomorphic rods and inflammatory cells were present in its semen. The isolates
were biochemically similar to the A. seminis type strain NCTC 10851 and two other
European A. seminis isolates, except that they produced acid from sorbitol; their
identity was confirmed by arbitrarily primed polymerase chain reaction. The
isolates were also tested against 30 antimicrobial agents, and only marbofloxacin
was found active against all of them. As far as is known, this is the first
report of A. seminis isolation from rams in southern Europe.
PMID- 10684693
TI - Bilateral deafness in a maltese terrier and a great pyrenean puppy: inner ear
morphology.
AB - Two puppies, a 4-month-old female Maltese terrier and a 6-week-old male Great
Pyrenean, were presented for confirmation of bilateral deafness by
electrophysiological testing. In both puppies, brainstem auditory potentials were
not evoked by 90 dB NHL click stimulation of each ear. Examination of the inner
ear revealed a bilateral cochleo-saccular degeneration in both animals. The
lesions were characterized by generalized atrophy of the stria vascularis,
collapse of the cochlear duct, degeneration of the organ of Corti, an abnormal
tectorial membrane, and saccular collapse, with a normal spiral ganglion. The
cochlear duct was entirely obliterated throughout the cochleae in the Maltese
terrier puppy, but was locally and asymmetrically affected in the Great Pyrenean.
The abnormalities observed in the Maltese terrier puppy were identical with those
previously described in deaf Dalmatian puppies; the lesions observed in the Great
Pyrenean, however, were less typical. This is the first histopathological
description of cochleo-saccular degeneration in the Maltese terrier and Great
Pyrenean breeds. In both puppies the defect was probably congenital.
PMID- 10684695
TI - Reply.
PMID- 10684694
TI - Natural infection with schistosomes of the Schistosoma haematobium group in a dog
in Zambia.
AB - Post-mortem examination of an adult male Jack Russell dog from Zambia revealed
that it was heavily infected with schistosomes. The dog had been admitted, with a
history of retching, 4 days before its death. At necropsy, the liver was found to
be enlarged, with multiple pin-point yellowish-white foci scattered diffusely
throughout the organ. Multiple pin-point recent and old haemorrhages were seen on
the mucosal surface of the gastrointestinal tract, particularly in the stomach
and proximal duodenum. Large numbers of schistosome worm pairs and eggs were
found in all mesenteric, gastric and hepatic veins. Histological examination of
the intestines, mesenteric lymph nodes, liver, spleen, pancreas, stomach and
lungs revealed numerous strongly fibrotic, encapsulated, epithelioid-giant cell
granulomata containing dead, degenerating and viable eggs. A few examples of the
Splendore-Hoeppli phenomenon were also detected. The eggs collected at necropsy
had a terminal spine and an average length and breadth of 187.6+/-14.1 microm and
57. 3+/-4.1 microm, respectively. DNA analysis of female worms indicated that the
schistosomes were either Schistosoma haematobium or a hybrid of Schistosoma
mattheei and S. haematobium.
PMID- 10684696
TI - Ecotoxicology and Environmental Safety Environmental Research, Section B.
PMID- 10684697
TI - Endometrial intraepithelial neoplasia (EIN): will it bring order to chaos? The
Endometrial Collaborative Group.
AB - The diagnosis of precancerous lesions of the endometrium remains unstandardized
because existing World Health Organization classification categories do not
correspond to distinctive biologic groups and are inadequately supported by
reproducible histopathologic criteria. A group of gynecologic pathologists was
convened to consider revised diagnostic classification and criteria based on
newly available information. We propose the terms endometrial hyperplasia (EH),
endometrial intraepithelial neoplasia (EIN), and adenocarcinoma to define
distinctive subgroups that are functionally relevant to clinical management of
patients with endometrial disease. Endometrial precancers are collectively
designated EIN in recognition of their monoclonal growth. At present there is no
effective strategy for constructive subdivision of EIN lesions into grades or
subgroups. EIN is to be distinguished from adenocarcinoma and the diffuse
hormonal changes of EH seen in anovulation. An archive of genetically and
morphologically classified endometrial precancers at www.endometrium.org provides
a resource for centralized review of the histopathology of EIN lesions. A new
architectural criterion for EIN diagnosis, diminution of stromal volume to less
than approximately half of the total sample volume, will also assist in
discriminating between EH and EIN. Implementation of this proposal will bring
diagnostic terminology into agreement with current concepts of premalignant
endometrial disease and facilitate more uniform patient management.
PMID- 10684698
TI - BRCA1: what do we know? What do we think we know? What do we really need to know?
PMID- 10684699
TI - Reduction of BRCA1 expression in sporadic ovarian cancer.
AB - OBJECTIVE: The purpose of this study was to examine BRCA1 expression and its
relationship to cell proliferation in sporadic ovarian epithelial tumors (OETs).
METHODS: We investigated BRCA1 expression and cell proliferative activity in 72
unselected OETs. They comprised 16 benign cystadenomas, 18 borderline (low
malignant potential) tumors, and 38 carcinomas (OECs). These patients had no
known family history of breast and/or ovarian cancer. BRCA1 and the cell
proliferation marker, MIB-1, expressions in fixed tissue were investigated in all
72 cases by immunohistochemistry (IHC). BRCA1 mRNA in fresh frozen tissue samples
from 20 of these cases was measured by a semi-quantitative reverse transcription
polymerase chain reaction (RT-PCR) method. RESULTS: The average percentage of
BRCA1-positive cells was 5.6% in cystadenomas, 29.7% in borderline tumors, and
6.6% in OECs. The average decreased steadily with increasing grade of OECs: grade
1 (21.4%), grade 2 (1.1%), and grade 3 (0%). The average percentage of MIB-1
positive cells increased steadily from cystadenomas (7.5%) to borderline tumors
(22.6%) to carcinomas (41.2%). BRCA1 expression was highly correlated with MIB-1
expression in cystadenomas and borderline tumors. Six of seven OECs negative for
BRCA1 by IHC showed low levels of BRCA1 mRNA by RT-PCR. CONCLUSIONS: BRCA1
expression paralleled cell proliferation in benign and borderline OETs, but not
in OECs. Sporadic OECs showed significantly reduced levels, rather than complete
loss, of BRCA1 expression. The reduction was closely related to tumor grade.
Reduction of BRCA1 expression may be of etiologic significance in the occurrence
and progression of sporadic ovarian cancer.
PMID- 10684700
TI - The balanced life: a discussion of stress in gynecologic oncology.
PMID- 10684701
TI - Gene therapy for endometrial carcinoma with the herpes simplex thymidine kinase
gene.
AB - We investigated whether retrovirus-mediated transfer of the herpes simplex
thymidine kinase gene into a human endometrial carcinoma (EC4) cell line can
sensitize these cells to the prodrug ganciclovir (GCV) and thereby provide a
therapeutic option for this cancer. A retrovirus encoding for the herpes simplex
virus tip-1 (HSV) thymidine kinase (tk) gene was generated in which expression of
tk is under control of the myeloproliferative sarcoma virus (MPSV)
promoter/enhancer. We used human mutated dihydrofolate reductase (DHFR) cDNA as a
selectable marker. Expression of tk was confirmed by Northern blot analysis and
reverse transcription polymerase chain reaction. We demonstrated that the
combination of retrovirally mediated tk gene transfer and GCV treatment
effectively inhibits proliferation and causes death of EC4 cells in vitro. A
bystander killing effect was observed when 90% of uninfected tumor cells were
mixed with only 10% of HSVtk-infected cells. We suggest that a gene therapy
approach to endometrial carcinoma can be established using retroviral transfer of
HSVtk to tumor cells and subsequent administration of GCV.
PMID- 10684702
TI - Positive margins after conization and risk of persistent lesion.
AB - OBJECTIVE: The aim of this study was to investigate a method to reduce the
frequency of uterine reoperation with no persistent lesion and to identify
factors predictive of persistent or recurrent lesions. MATERIALS AND METHODS: Of
505 conizations performed by the same surgeon, 71 had positive margins (average
patient age = 35.7 +/- 7.7 years). The patients underwent either immediate
reoperation or monitoring with a Pap smear and colposcopy. RESULTS: Histologic
assessment of the cervical cone after conization showed positive margins in 14.1%
of cases [endocervical and exocervical margins affected in 50 of 505 (9.9%) and
21 of 505 (4.2%) cases, respectively]. Of 59 of these patients (83.1%) who
underwent follow-up monitoring over an average of 35.2 months (range: 2.6-180.
8), 12 patients (average age: 40.8 +/- 6.4 years) underwent immediate
hysterectomy and 47 (average age 34.0 +/- 7.4 years) benefited from monitoring
first [secondary discovery of 19 persistent lesions within 6 months and 9
recurrences within 18 months on average (range: 8.8-48 months)]. Of the 9
patients with recurrent lesions, 7 underwent reintervention and 2 monitoring. Of
the 19 patients with persistent lesions, 18 underwent reintervention and 1
monitoring. Normal histology was observed in 29.4% of patients undergoing
secondary reoperation for an abnormal smear compared with 66.7% of patients
undergoing immediate reoperation (P = 0.04). Severity of lesion and age of
patients could not be used to predict the incidence of a persistent or recurring
lesion. Seventy-nine percent of conizations had positive endocervical margins in
patients with a recurring or persistent lesion compared with 48% in patients with
normal follow-up (P = 0.03). CONCLUSION: Cytology and colposcopy follow-up in
cases of positive conization margins may help to establish justification for the
choice of reoperation, thereby limiting morbidity following repeated surgery.
PMID- 10684703
TI - HIV+ patients have increased lymphocyte infiltrates in CIN lesions.
AB - OBJECTIVE: The objective of our study was to analyze immunocyte infiltrates in
CIN lesions from HIV+ patients to assess whether local immunosuppression, defined
as a decrease in T cell infiltrates, could explain the aggressive nature of CIN
in HIV-infected patients. MATERIALS AND METHODS: Cervical tissue was obtained
from 6 HIV+ CIN patients, 6 HIV- CIN patients, who underwent LLETZ (large loop
excision of the transformation zone) for CIN, and 17 normal patients who
underwent hysterectomy for benign indications. The following cell surface markers
were analyzed: CD20 (B cells), CD4 (T helper cells), and CD8 (T
suppressor/cytotoxic cells). Each tissue section was visualized with a Leica
microscope at 400x and the image was captured for analysis by Harmony Group image
analysis software. RESULTS: A significantly higher number of lymphocytes (both B
and T cells) was detected in the stroma of HIV+/CIN tissue compared to either HIV
/CIN or normal tissue. There was also a significant increase in CD8+ cells in the
HIV+/CIN group compared to HIV-/CIN or normal tissue. There was a trend toward a
decreased CD4+/CD8+ ratio in the HIV+/CIN compared to the other two groups;
however, this did not reach statistical significance. CONCLUSIONS: This study
indicates that HIV+/CIN cervical tissue has a greater number of tissue
lymphocytes recruited to the neoplastic site compared to HIV- individuals. In
addition, HIV+ patients may have a decreased CD4/CD8 ratio in locally
infiltrating immunocytes in CIN lesions. The local immunomodulatory effects of
HIV may be detectable early in infection and therefore may explain the aggressive
nature of CIN in the HIV+ patient.
PMID- 10684704
TI - High cyclooxygenase-2 expression in stage IB cervical cancer with lymph node
metastasis or parametrial invasion.
AB - OBJECTIVE: The enzymes cyclooxygenase (COX)-1 and -2 are necessary for the
synthesis of prostaglandins. COX-2 is usually absent in normal cells and is
upregulated and expressed as a product of the "immediate early" gene during
inflammatory processes. In previous studies, the expression of COX-2 has been
shown to be induced by proinflammatory cytokines, and suggestions have been made
that overexpression of COX-2 suppresses apoptosis and is directly related to
tumor growth. We have attempted to determine a relationship between tumor
invasion and metastasis of uterine cervical cancer and COX and apoptosis by
comparing the protein expression of apoptosis, COX-1, and COX-2 in tumor tissues.
METHODS: The subjects were 36 patients who were FIGO stage IB uterine cervical
cancer patients who underwent surgery at Ajou University Hospital. There were 12
cases with lymph node or parametrial involvement. All tissues were subjected to
immunohistochemical staining for COX-1, -2, and TUNEL method for apoptosis
detection, and the following results were obtained. RESULTS: Tumor tissues
confirmed by cytokeratin were separated into tumor surface, tumor stroma, and
invasion site portions, in which decreased apoptosis was observed in the invasion
sites. COX-2 expression was observed in all tumor tissues and was especially
strong in the tumor invasion site. Therefore, it is suggested that COX-2
expression may suppress cell apoptosis at the tumor invasion site. When COX-2
expression was investigated according to the groups with regard to the presence
of lymph node or parametrial involvement, there was a statistically significant
(Mann-Whitney U test) COX-2 expression difference in the tumor invasion site (P
value = 0.040) and the tumor stroma (P value = 0. 028). CONCLUSIONS: In
surgically treated stage IB cervical cancer patients, COX-2 was significantly
expressed when lymph node or parametrial involvement was present. These results
suggest that the expression of COX-2 in stage IB cervical cancer may downregulate
apoptotic processes and thus enhance tumor invasion and metastasis.
PMID- 10684705
TI - Effects of paclitaxel on CA-125 serum levels in ovarian cancer patients.
AB - OBJECTIVE: As in vitro activation of ovarian carcinoma cells in terms of CA-125
secretion by taxanes has been demonstrated, we were interested in whether taxanes
also modulate CA-125 expression in vivo. METHODS: Serum CA-125 was determined
immediately before and 24 h after paclitaxel-containing chemotherapy in 53
ovarian carcinoma patients. To test the quality of the analysis methods and the
biological variation of untreated patients, serum CA-125 levels of two control
groups were analyzed. RESULTS: Median CA-125 concentration was 107 kU/liter 24 h
after chemotherapy treatment compared with 99 kU/liter the day before paclitaxel
treatment. Changes in CA-125 serum levels observed immediately after paclitaxel
treatment were not correlated to treatment response. However, overall change in
CA-125 serum concentration was a good predictor of response to paclitaxel
containing treatment. Patients achieving a complete or partial response had a
significant reduction of median CA-125 levels, whereas tumor progression was
associated with increased CA-125 levels. Only for the group of patients obtaining
a complete response was a decrease in the median relative CA-125 value observed.
CONCLUSION: Paclitaxel-induced modulation of CA-125 expression could not be
confirmed in vivo.
PMID- 10684706
TI - Clear cell carcinoma of the uterine cervix: pathology and prognosis in surgically
treated stage IB-IIB disease in women not exposed in utero to diethylstilbestrol.
AB - OBJECTIVE: The purpose of this research was to compare the clinical behavior,
pathology findings, and prognosis of surgically treated FIGO stage IB-IIB clear
cell carcinomas of the cervix with those of squamous cell carcinomas and non
clear cell adenocarcinomas. METHODS: Fifteen patients with clear cell
adenocarcinomas of the cervix (8 FIGO stage IB, 7 FIGO stage IIB) were reviewed.
The control group consisted of 444 squamous cell carcinomas and 59 non-clear cell
adenocarcinomas. None of the patients had a history of in utero exposure to
diethylstilbestrol. All patients underwent radical abdominal hysterectomy with
systematic pelvic lymphadenectomy. All specimens were processed as serial giant
frontal sections. The mean follow-up in the clear cell group was 83 (13-182)
months. Statistical analysis was done with contingency tables, chi(2) tests, and
Fisher's exact test. RESULTS: Twelve of the fifteen clear cell carcinomas (80%)
were endophytic and tended toward deep cervical infiltration. Clear cell
carcinomas extended to the uterine corpus significantly more often than squamous
cell and non-clear cell adenocarcarcinomas (P < 0.001). The rates of parametrial
involvement and pelvic lymph node involvement were 40 and 47%, respectively. Four
patients (27%), all with positive pelvic nodes, developed recurrences an average
of 14 (4-48) months after initial therapy. The extrapelvic sites of relapse were
the lung, liver, and bone. Clear cell carcinomas had a worse 5-year survival rate
(67%) than squamous cell carcinomas (80%) and non-clear cell adenocarcinomas
(77%) but this was not statistically significant (P = 0.6). No significant
differences were seen for age, growth pattern, parametrial and vaginal
involvement, parametrial and pelvic lymph node metastases, frequency of recurrent
disease, and time to first recurrence. CONCLUSION: The clinicopathologic findings
and prognosis of surgically treated patients with stage IB-IIB clear cell
carcinomas without exposure to diethylstilbestrol in utero are similar to those
of patients with squamous cell carcinomas and non-clear cell adenocarcinomas.
PMID- 10684707
TI - Serum MAGE-4 protein in ovarian cancer patients.
AB - OBJECTIVE: We measured serum levels of MAGE-4 protein in patients with ovarian
cancer to investigate the relationship between serum MAGE-4 positivity and
prognosis. METHODS: Serum levels of MAGE-4 protein were measured with an ELISA
system. RESULTS: Serum levels of MAGE-4 in patients with ovarian cancer were
significantly higher than levels in patients with benign diseases. Serum MAGE-4
protein was considered positive in 22% of primary ovarian cancer patients. The
positive rate was the highest in sera of patients with surface epithelial-stromal
tumors, particularly serous adenocarcinomas (24%). The survival time after a
primary surgical operation in ovarian cancer patients with serum MAGE-4
positivity was significantly shorter than that of MAGE-4-negative cases.
CONCLUSION: These results suggest that serum MAGE-4 protein is a potential
prognostic factor of reduced survival in ovarian cancer patients.
PMID- 10684708
TI - Expression and clinical significance of apolipoprotein D in epithelial ovarian
carcinomas.
AB - OBJECTIVE: Apolipoprotein D is a protein component of the human plasma lipid
transport system but is also associated with a more favorable prognosis in women
with breast cancer. This retrospective study was undertaken to examine the
tumoral expression of apolipoprotein D in epithelial ovarian cancer and to
analyze the possible correlation with tumor and patient characteristics as well
as androgen receptors and their prognostic significance. METHODS:
Immunohistochemical evaluation was used to examine apolipoprotein D expression in
paraffin blocks from 68 epithelial ovarian carcinomas. RESULTS: A total of 18
(26.4%) tumors stained positively. No significant correlation was found between
apolipoprotein D expression and patient or tumor characteristics and androgen
receptor status. However, apolipoprotein D expression was significantly
associated with prognosis in patients with residual tumor greater than 1 cm.
Thus, patients with apolipoprotein-D-negative tumors had a poorer overall
survival than those with apolipoprotein-D-positive tumors (P = 0.039). In
addition, multivariate analysis demonstrated that apolipoprotein D expression was
an independent prognostic factor with initial tumor size in this group of
patients (P = 0.005). CONCLUSIONS: Our results led us to consider the existence
of apolipoprotein D expression by a significative percentage of ovarian
carcinomas, and this protein expression might be of clinical usefulness for
identifying lesions with different evolution.
PMID- 10684709
TI - Potential therapeutic role of para-aortic lymphadenectomy in node-positive
endometrial cancer.
AB - OBJECTIVE: The aim of this study was to assess the potential therapeutic role of
para-aortic lymphadenectomy (PAL) in high-risk patients with endometrial cancer.
METHODS: We studied two groups of patients with endometrial cancer who underwent
operation at Mayo Clinic (Rochester, MN) during the interval 1984 to 1993: (1)
137 patients at high risk for para-aortic lymph node involvement (myometrial
invasion >50%, palpable positive pelvic nodes, or positive adnexae), excluding
stage IV disease, and (2) 51 patients with positive nodes (pelvic or para
aortic), excluding stage IV disease. By our definition, PAL required removal of
five or more para-aortic nodes. RESULTS: In both groups, no significant
difference existed between patients who had PAL (PAL+) and those who did not (PAL
) in regard to clinical or pathologic variables, percentage irradiated, or
surgical or radiation complications. Among the 137 high-risk patients, the 5-year
progression-free survival was 62% and the 5-year overall survival was 71% for the
PAL- group compared with 77 and 85%, respectively, for the PAL+ group (P = 0.12
and 0.06, respectively). For the 51 patients with positive nodes, the 5-year
progression-free survival and 5-year overall survival for the PAL- group were 36
and 42% compared with 76 and 77% for the PAL+ group (P = 0.02 and 0.05,
respectively). Lymph node recurrences were detected in 37% of the PAL- patients
but in none of the PAL+ patients (P = 0.01). Multivariate analysis suggested that
submission to PAL was a cogent predictor of progression-free survival (odds ratio
= 0.25; P = 0.01) and overall survival (odds ratio = 0.23; P = 0.006).
CONCLUSIONS: These results suggest a potential therapeutic role for formal PAL in
endometrial cancer.
PMID- 10684710
TI - Clinical value of intraoperative gross examination in endometrial cancer.
AB - We present the largest multicenter study evaluating whether intraoperative visual
estimation can accurately assess the depth of myometrial invasion in patients
with endometrial cancer. The study population consisted of 403 consecutive women
who underwent total hysterectomy for endometrial cancer. After the uterus was
removed, a visual estimate of depth of gross myometrial invasion was recorded.
The uterus was opened, the endometrial cavity was inspected, and one or more full
thickness incisions were made through the tumor, myometrium, and serosa. An
intraoperative estimation of gross myometrial invasion was made and classified as
more or less than 50% of the uterine wall. Gross visual estimation accurately
identified the microscopic myometrial invasion in 85.3% (344/403) of cases.
Sensitivity, specificity, and positive and negative predictive values of gross
estimation in determining a microscopic myometrial invasion greater than 50% were
73.0, 92.5, 85.0, and 85.5%, respectively. Among patients in whom the myometrial
invasion was underestimated at gross examination the tumoral invasion was limited
to the inner two thirds of the myometrium in 45% (18/40) of cases and the
distance from the tumor-myometrial junction to the uterine serosa was greater
than 3 mm in 65% (26/40) of cases. We conclude that gross estimation of
myometrial invasion is a reliable and inexpensive method for evaluating the
invasiveness of uterine carcinomas and that deciding to perform an extensive
surgical staging upon gross estimation will be in accordance with the final
histopathologic report in about 9 of 10 cases.
PMID- 10684711
TI - Development of a panel of 15 human ovarian cancer xenografts for drug screening
and determination of the role of the glutathione detoxification system.
AB - OBJECTIVES: We have established a panel of 15 human ovarian cancer xenografts
grown subcutaneously in the flank of the nude mouse. Similar to the clinic, the
xenografts show differences in histological subtype and volume doubling time. We
determined whether the panel is useful for drug screening by testing the
sensitivity to six conventional anticancer agents. In addition, we investigated
whether the glutathione detoxification system affects sensitivity to cisplatin
and cyclophosphamide, major drugs in the treatment of ovarian cancer. METHODS:
Mice bearing well-established tumors were treated at maximum tolerated doses as
defined by a reversible weight loss up to 15% of their initial weight: cisplatin
5 mg/kg iv weekly x2, cyclophosphamide 150 mg/kg ip 2-weekly x2, doxorubicin 8
mg/kg iv weekly x2, hexamethylmelamine ip 150 mg/kg every other day x4,
methotrexate ip 150 mg/kg weekly x2, and 5-fluorouracil 60 mg/kg ip weekly x4.
Glutathione levels and the activities of three different glutathione-dependent
enzymes were measured in untreated xenograft tissues. RESULTS: Growth inhibition
>75% was reached for cisplatin in 40%, for cyclophosphamide in 27%, and for
doxorubicin in 20% of the xenografts. Methotrexate and 5-fluorouracil did not
induce growth inhibition of importance. Hexamethylmelamine showed >75% growth
inhibition in 53% of the xenografts, which may have been caused by the favorable
metabolism of the drug in mice when compared with that in patients. Glutathione
levels varied 3.6-fold in the xenografts and did not show a relation with
sensitivity to cisplatin, cyclophosphamide, or doxorubicin. No relation was found
between the activities of glutathione S-transferase and glutathione peroxidase
and the sensitivities to the three anticancer agents. Glutathione reductase
activity, however, showed a weak, inverse relation with the efficacy of cisplatin
and cyclophosphamide (r values of -0.55 and -0.58, respectively). CONCLUSIONS:
The sensitivity to the six anticancer agents of our panel of 15 human ovarian
cancer xenografts reflects the response rates known for similar drugs in ovarian
cancer patients. In that respect, the panel may be useful for drug screening as
well as studies on the relevance of drug resistance features in vivo. The various
components of the glutathione detoxification system did not predict for primary
drug resistance which confirms clinical data in ovarian cancer.
PMID- 10684712
TI - Genetic alterations of the WT1 gene in papillary serous carcinoma of the
peritoneum.
AB - OBJECTIVE: The Wilms' tumor (WT1) gene product is consistently detectable in both
normal ovarian germinal epithelium and human mesothelium. Ovarian carcinomas
frequently exhibit alterations in WT1 function. Papillary serous carcinoma of the
peritoneum (PSCP) is believed to develop de novo from the peritoneal lining
(mesothelium) of the pelvis and abdomen. The purpose of this study was to
determine if genetic alterations of the WT1 gene are associated with the
development of PSCP. METHODS: Normal and tumor tissue specimens were retrieved
from patients with stage III and IV PSCP (n = 38) and serous epithelial ovarian
carcinoma (n = 38). Immunohistochemistry was performed using the anti-WT1 (C-19)
antibody. Loss of heterozygosity (LOH) was performed at the WT1 locus. Clinical
data were obtained and correlated with molecular findings. RESULTS: Loss of
normal WT1 expression was detected in 18 (51%) of 35 PSCP specimens and 18 (53%)
of 34 ovarian carcinoma specimens. Six (27%) of 22 PSCP specimens and 3 (13%) of
24 ovarian carcinoma specimens had LOH at the WT1 locus (P = 0.27). Normal WT1
gene expression was maintained in 86% of tumors exhibiting LOH. Genetic
alterations of the WT1 gene were not predictive of survival, nor were they
associated with other clinical or molecular factors. CONCLUSIONS: Genetic
alterations of the WT1 gene are associated with the development of PSCP. The loss
of normal WT1 gene expression is a common event in both PSCP and advanced ovarian
carcinoma, likely resulting from down-regulation by other regulatory factors-not
from inactivating gene mutation and subsequent allelic loss.
PMID- 10684713
TI - The prognostic significance of radiation dose and residual tumor in the treatment
of barrel-shaped endophytic cervical carcinoma.
AB - OBJECTIVE: The aim of this study was to evaluate the impact of total radiation
dose on residual tumor and the prognostic significance of persistent disease in
women with bulky, barrel-shaped cervical carcinoma who received definitive
radiation followed by adjuvant hysterectomy. METHODS: The medical records of 57
patients with bulky endophytic cervical carcinoma treated at the University of
Washington between 1976 and 1997 were reviewed. All patients received external
beam pelvic radiotherapy supplemented by intracavitary brachytherapy, followed by
extrafascial hysterectomy 6 to 8 weeks later. RESULTS: The mean pretreatment
tumor diameter was 5.9 cm, with a range of 4-9 cm. Total radiation dose to point
A ranged from 5040 to 9700 cGy, and the mean for the group was 7966 cGy. Residual
disease was present in 35 (61%) of the hysterectomy specimens. The frequency of
cervical tumor sterilization correlated significantly with the mean radiation
dose to point A (P = 0.016). Patients without histologic residual disease had a
significantly improved outcome, with 95% of patients remaining clinically free of
disease at last follow-up, versus 31% of those with residual disease (P < 0.001).
As expected, the pelvic control rate was excellent (100%) in patients with
complete tumor eradication compared to the group with residual tumor (44%). Those
with no residual disease enjoyed a significantly improved survival compared to
those with residual tumor (P < 0.001). Furthermore, a statistically significant
higher survival was realized in patients harboring only microscopic residual
compared to those with either macroscopically evident tumor residuum and/or
positive surgical margins (P = 0.036). CONCLUSIONS: Higher radiation doses are
associated with an improved likelihood of tumor eradication in the treatment of
bulky, endophytic cervical cancer and complete tumor sterilization at adjuvant
hysterectomy is predictive of significantly enhanced survival and pelvic control.
The high rate of histologic tumor persistence in our series emphasizes the need
for more efficacious therapies in patients with bulky endophytic cervical cancer
and argues for escalation of radiation dose even when adjuvant hysterectomy is
planned.
PMID- 10684714
TI - Laparoscopic loop colostomy for advanced ovarian cancer, rectal cancer, and
rectovaginal fistulas.
AB - OBJECTIVES: The objectives of this study were to present a minimal invasive
technique of intestinal diversion for selected cases of advanced inoperable
ovarian cancer, rectal cancer, and rectovaginal fistulas, and to discuss
indications, pitfalls, and potential complications. METHODS: The technical
features of laparoscopic colostomy are described. RESULTS: Between August 1995
and July 1997 laparoscopic colostomy was successfully carried out in 12 patients
with advanced ovarian cancer, inoperable carcinoma of the rectum, or rectovaginal
fistulas. There were no intraoperative or postoperative complications and
postoperative recovery was rapid, with all patients having function of the
colostomy within 24 h and regaining their preoperative state of mobility on the
second postoperative day. CONCLUSION: The laparoscopic approach allows careful
selection of the colostomy site and easy mobilization of the colon, causing only
little disruption to intestinal function and, hence, improving postoperative
recovery. From our experience, laparoscopic colostomy is in most cases a simple
and safe operation and can be used as the preferred technique of intestinal
diversion.
PMID- 10684715
TI - Assessing disease extent in women with bulky or clinically evident metastatic
cervical cancer: yield of pretreatment studies.
AB - OBJECTIVE: The objective of this study was to determine the impact of
pretreatment tests on staging and management for women with bulky or clinically
evident metastatic cervical cancer. METHODS: Demographics and findings of clinic
pelvic examination (PE), examination under anesthesia (EUA), chest x ray (CXR),
abdominopelvic computed tomography (CT), and intravenous urography (IVU) were
reviewed for women with primary, untreated cervical cancers either > or =4 cm or
with extracervical disease apparent on PE or CXR evaluated between July 1, 1994,
and March 31, 1999. Stage was assigned according to standards of the
International Federation of Gynecology and Obstetrics. RESULTS: In 133 women
studied, tumor diameter averaged 4. 9 cm on PE and 5.7 cm at EUA (P = 0.0005). Of
92 women undergoing both PE and EUA, 30 (33%) had size discrepancies of more than
1 cm. Compared with EUA, PE had sensitivity, specificity, and positive and
negative predictive values, respectively, of 65, 89, 79, and 81% for vaginal
disease, 74, 91, 95, and 63% for parametrial disease, and 57, 90, 60, and 89% for
sidewall fixation. CXR was abnormal in 5 (4%). IVU showed ureteral dilation in 20
(22%) of 90 women, while CT showed dilation in 34 (28%) of 123 women. CT also
showed pelvic lymphadenopathy in 22 (18%) women and paraaortic lymphadenopathy in
12 (10%). Bladder biopsies showed malignancy in 8 (8%), including one
transitional cell carcinoma of the bladder. Proctoscopy failed to reveal
metastatic cervical cancer. CONCLUSIONS: CXR and EUA with cystoscopy are
important to the accurate staging and treatment of bulky or clinically metastatic
cervical cancers, while proctoscopy is rarely useful. CT predicts ureteral
obstruction well, and its greater information yield may justify its higher cost
compared with IVU.
PMID- 10684716
TI - Expression of fos and jun proto-oncogenes in benign versus malignant human
uterine tissue.
AB - OBJECTIVE: The objective of this study was to evaluate expression of fos and jun
proto-oncogenes in benign human uterine tissue compared with malignant uterine
tissue. METHODS: Forty-two endometrial tissue specimens were obtained at the time
of hysterectomy. Tissue samples from different phases of the menstrual cycle and
from postmenopausal patients were stained using immunohistochemical methods to
detect Fos and Jun proteins, estrogen and progesterone receptor status, and Ki67
(detects a nuclear antigen associated with proliferating cells). Tissue was
examined microscopically for nuclear staining in endometrial epithelium and
stroma. The endometrium was based on the patient's last menstrual period,
pathologic dating, and proliferative versus nonproliferative status as determined
by Ki67. Benign and malignant specimens were subjected to Northern blot analysis
to evaluate levels of expression of c-fos, c-jun, and jun-B mRNA. The pattern of
c-fos mRNA expression in malignant samples was further evaluated using in situ
hybridization. RESULTS: In proliferative, secretory, postmenopausal, and
progesterone-influenced, uterine specimens immunohistochemically stained and
examined, the endometrial and stromal nuclei stained for both Fos and Jun in
varying intensities. However, no pattern was found in the variation of intensity
according to the phase of the endometrium. Similarly, in malignant and benign
endometrial tissue examined by Northern blot and in situ hybridization analyses,
expression of proto-oncogene mRNAs was readily detectable, but no statistical
correlation between type of tissue examined, grade of adenocarcinoma, and stage
of endometrial cancer was found in this study. CONCLUSIONS: In rodent models,
control of uterine cell proliferation is related to change in expression of fos
and jun proto-oncogenes. Our results indicate that hormonal control is likely to
be different in human endometrium and probably involves genes other than the
proto-oncogenes under study. Expression of Fos and Jun do not correlate with
endometrial cancer stage and grade.
PMID- 10684717
TI - Intraperitoneal photoimmunotherapy of ovarian carcinoma xenografts in nude mice
using charged photoimmunoconjugates.
AB - OBJECTIVE: The objective of this study was to compare the efficacy of
photoimmunoconjugates with cationic and anionic molecular charges on
intraperitoneal photoimmunotherapy of ovarian cancer xenografts in nude mice.
METHODS: The photosensitizer chlorin(e6) (c(e6)) was conjugated via a poly-l
lysine linker to the F(ab')(2) fragment of the murine anti-ovarian cancer
monoclonal antibody OC125, resulting in a photoimmunoconjugate with a pronounced
cationic charge. Alternatively, by succinylating the poly-l-lysine conjugate, a
photoimmunoconjugate with a pronounced anionic charge was obtained. A murine
model of ovarian cancer derived from intraperitoneal inoculation of NIH:OVCAR-5
cells was employed. The conjugate was injected intraperitoneally followed after 3
h by red light delivered through a fiber into the peritoneal cavity. These
photoimmunotherapy treatments were repeated three times, and the results obtained
with the anionic and cationic photoimmunoconjugates were compared with those
obtained with free c(e6) and control. The extent of residual macroscopic disease
and death from disease were the evaluable outcomes for tumoricidal and survival
studies, respectively. RESULTS: In contrast to other intraperitoneal
photosensitizers, mice showed no systemic toxicity or morbidity from the
treatment. In this initial study the mean residual tumor weights in all treatment
groups ranged from 33 to 73 mg, as compared with 330 mg in untreated controls (P
< 0.0001), and the response to the cationic conjugate was significantly better
than that to the anionic conjugate or free c(e6) (P < 0.005). The median survival
for mice treated with cationic photoimmunoconjugate was 41 days, compared with 35
days in controls (P = 0.009). CONCLUSION: Photoimmunotherapy with a cationic
photoimmunoconjugate produces results superior to those obtained with an anionic
conjugate, and further optimization of the treatment regimen may lead to a
potential treatment for advanced ovarian cancer.
PMID- 10684718
TI - Clinical applicability of the ATP cell viability assay as a predictor of
chemoresponse in platinum-resistant epithelial ovarian cancer using nonsurgical
tumor cell samples.
AB - OBJECTIVES: There is no basis for choosing one chemotherapy over another in
platinum-resistant epithelial ovarian cancer based on published response rates.
This study explores the feasibility and accuracy of the ATP cell viability assay
(ATP-CVA) in predicting chemoresponse in these difficult situations to choose the
most appropriate drug for treatment. METHODS: Predominantly nonsurgical tumor
samples for histological proof of recurrence were tested against a panel of drugs
for salvage chemotherapy. Clinicians were blinded to the test results. Patient
responses were evaluated after a minimum of three cycles of single-agent
chemotherapy and correlated with test results. RESULTS: The evaluability rate was
85% (5 of 33 contaminated). The majority (24) were obtained by abdominal
paracentesis and trucut biopsy. Of the 28 successful assays, 8 were excluded from
analysis because four chose not to have chemotherapy and four withdrew after
fewer than three cycles because of unacceptable side effects. The overall
response rate to salvage chemotherapy was 15%. The sensitivity was 100% and
specificity 82%. Resistance was correctly predicted in 100% and response
correctly predicted in 50%. The outcomes of 17 of 20 patients were predicted
correctly, giving an accuracy of 85%. CONCLUSIONS: It is feasible to test
nonsurgical tumor specimens in recurrent cancer. The ATP-CVA correctly identified
a group of patients with a 50% chance of response to salvage chemotherapy. This
information may be useful in the decision-making process. A prospective,
randomized study will be done to confirm these results.
PMID- 10684719
TI - Unusual recurrence of cervical adenosquamous carcinoma after conservative
surgery.
AB - The use of less radical procedures for the treatment of early cervical cancers is
gaining interest among physicians and young patients. Some authors have described
surgical procedures aimed at reducing the surgical aggressiveness but the safety
of such procedures remains debated. After a polypectomy, a young patient had a
diagnosis of stage Ia(2) cervical adenosquamous carcinoma in 1995. As she wished
to preserve her fertility, she underwent a cone biopsy and pelvic
lymphadenectomy, without evidence of tumor spread. In 1998, at the 13th week of
gestation, she had a diagnosis of a pelvic mass. The mass was a recurrence of
carcinoma involving the myometrium, just underneath the peritoneum. She underwent
a radical hysterectomy with bilateral oophorectomy. An ovarian metastasis was
also detected at pathological exam. She received chemotherapy postoperatively and
remains alive without evidence of disease. The recurrence of cervical cancer is
traditionally regarded as an issue concerning the cervix, the parametria, or the
lymph nodes. When the uterus is preserved we must also consider the possibility
of a recurrence involving the corpus. With wider acceptance of limited
therapeutic approaches we must be prepared for the detection of previously
unknown patterns of recurrence and the follow-up modalities must be consequently
adapted.
PMID- 10684720
TI - Ovarian cancer in female-to-male transsexuals: report of two cases.
AB - BACKGROUND: Ovarium cancer is the fifth most common cause of cancer-related death
in women and is the most common fatal gynecologic malignancy. So far, ovarium
carcinoma has not been reported to have occurred in female-to-male transsexuals.
OBJECTIVE AND METHOD: We report on two such cases. Long-term exposure to
increased levels of endogenous and exogenous androgens is hypothesized to
constitute an additional risk factor in transsexuals as it has been associated
with ovarian epithelian cancer. CONCLUSION: Simultaneous salpingo-oophorectomy
should be performed in any female-to-male transsexual undergoing hysterectomy in
the course of gender-confirming therapy.
PMID- 10684721
TI - Hematogenous skin metastases from cervical cancer at primary presentation.
AB - OBJECTIVE: Cutaneous metastasis from carcinoma of the uterine cervix is an
uncommon occurrence. The majority of cases are diagnosed as recurrent carcinoma.
This is believed to be the first report of hematogenous skin metastases present
at the diagnosis of cervical carcinoma. METHODS: A case of a patient with
cutaneous manifestations at the time of cervical carcinoma diagnosis is
presented. RESULTS: Two lesions on the patient's hand occurred at points of
recent skin puncture. These were biopsy-proven metastases from her primary
cervical carcinoma. CONCLUSION: Skin metastases from cervical carcinoma are rare
and represent a poor prognostic sign.
PMID- 10684722
TI - Xp22.2-3 loss of heterozygosity is associated with germline BRCA1 mutation in
ovarian cancer.
AB - OBJECTIVE: X-Chromosome loss of heterozygosity (LOH) occurs in approximately 40%
of ovarian cancers. We have previously demonstrated an association between
nonrandom X-chromosome inactivation and germline BRCA1 mutation. The current
study examines the association between X-chromosome LOH and BRCA1 mutation.
METHODS: Ninety tumor DNA (81 ovary, 5 fallopian tube, 4 primary peritoneal) and
matched peripheral blood mononuclear cell DNA samples were examined for LOH with
11 X-chromosome microsatellite DNA markers. RESULTS: Tumor DNA demonstrated
frequent LOH at the Xp22.2-3 region (37.7% at DXS6807). Loss of heterozygosity on
Xp was twice as common in tumor DNA from germline BRCA1 mutation carriers (9/14
vs 19/67, P = 0.02). In four evaluable samples, Xp22.2-3 LOH preferentially
occurred from the active X allele. CONCLUSIONS: Our data support the hypothesis
that an Xp22.2-3 gene product interacts with or modifies the expression of BRCA1
in some hereditary ovarian cancers.
PMID- 10684723
TI - Sonographic follow-up in tamoxifene patients.
PMID- 10684724
TI - Letters to the editor
PMID- 10684725
TI - Restrictive endothelial barrier function during normal angiogenesis in vivo:
partial dependence on tyrosine dephosphorylation of beta-catenin.
AB - Differentiation of a restrictive endothelial barrier in the chick chorioallantoic
membrane (CAM) occurs between Day 4.5 and Day 5.0 of the normal 21-day gestation.
Whether molecular changes in the endothelial cell-cell junctional protein complex
contribute to the ontogeny of barrier function represents the principal focus of
this study. VE-cadherin has been shown to contribute to the regulation of
endothelial cell monolayer permeability in vitro. Accordingly, VE-cadherin is
complexed to the cytosolic catenins, and changes in monolayer permeability have
been linked to alterations of the cadherin/catenin complex. Currently, a CAM
endothelial VE-cadherin/beta-catenin complex was identified, and phosphotyrosine
labeling of beta-catenin was decreased concurrently with the abrupt increase in
CAM endothelial selectivity between Day 4.5 and Day 5.0. Further, inhibition of
protein tyrosine phosphatases impeded regular tyrosine dephosphorylation of beta
catenin at Day 5.0 and this served to partially restore macromolecular
extravasation to elevated levels normally present at Day 4.5. Thus,
differentiation of selective barrier function in the angiogenic CAM endothelium
in vivo is dependent, in part, on tyrosine dephosphorylation of beta-catenin.
PMID- 10684726
TI - Endothelin antagonists diminish postischemic microvascular incompetence and
necrosis in the heart.
AB - The endothelin receptor antagonists BQ-610 and BQ-123 were used to clarify the
role of endothelin in the pathogenesis of postischemic microvascular incompetence
in the myocardium. Forty-five isolated rat hearts were perfused with Krebs
Henseleit buffer (KHB) for 15 min and then subjected to 0, 15, or 60 min of
ischemia followed by 5 min of reperfusion with KHB, KHB + BQ-610, or KHB + BQ
123. They were fixed by perfusion with 2.5% glutaraldehyde and then perfused with
nuclear track emulsion as an indicator of vascular flow. Transmural sections of
resin-embedded myocardium were examined by scanning and transmission electron
microscopy. Following 60 min of ischemia, the subendocardial third of the LV wall
of hearts treated with BQ-123 showed nearly three times the proportion (P <
0.001) of competent capillaries in untreated hearts. Reperfusion after 15 min of
ischemia of hearts treated with BQ-123 showed a 30% increase in the proportion of
competent capillaries compared to controls (P < 0. 002). Treatment of
corresponding groups with BQ-610 increased the proportion of competent
capillaries but these differences were not statistically significant. In
addition, both ET-I antagonists dramatically reduced the amount of
ultrastructural change evident in myocardium reperfused after 60 min of ischemia.
Thus endothelin plays a significant role in the pathogenesis of postischemic
microvascular incompetence in the myocardium and, probably by its effects on
Ca(2+) uptake, contributes also to the ultrastructural damage to the myocytes and
endothelium which follows postischemic reperfusion of irreversibly injured
myocardium.
PMID- 10684727
TI - A novel model for the in vivo monitoring of uterine microcirculation and
intracellular free calcium changes in rat.
AB - The aim of this work was to develop a model to study the microcirculation and
relative levels of intracellular free calcium in the myometrium of pregnant rats.
On Day 21 of gestation a lobe of uterus was prepared free, flipped over, and
mounted in a superfusion chamber leaving the radix and thereby the innervation
and circulation intact. RBC velocity and arteriolar diameters were determined by
means of intravital video microscopy before and after stimulation
(norepinephrine). To study intracellular free calcium changes, the fluorescent
dye Indo-1 AM was added to the superfusate in the chamber. Fluorescence images
were recorded and ratios of the images collected at 400 and 506 nm were
calculated and changes thereof were assumed to represent intracellular free
calcium changes. RBC velocity and arteriolar diameter did not change for at least
1 h, while the response to norepinephrine was similar at the beginning of the
experiment and after 120 min. In four separate interventions, the uterus was
challenged with 5 x 10(-4) IU/ml oxytocin, 4.5 mM calcium, 5 x 10(-4) IU/ml
oxytocin with 4.5 mM calcium, and 5 microM ionomycin, resulting in an increase of
the 400/506 nm ratio of 27, 31, 76, and 103%, respectively, representing a
relative increase in intracellular free calcium. This novel in vivo model is
suitable for monitoring intracellular free calcium changes and to record RBC
velocities and blood vessel diameters in the myometrium of pregnant rats.
PMID- 10684728
TI - Generational analysis reveals that TGF-beta1 inhibits the rate of angiogenesis in
vivo by selective decrease in the number of new vessels.
AB - Quantitative analysis of vascular generational branching demonstrated that
transforming growth factor-beta1 (TGF-beta1), a multifunctional cytokine and
angiogenic regulator, strongly inhibited angiogenesis in the arterial tree of the
developing quail chorioallantoic membrane (CAM) by inhibition of the normal
increase in the number of new, small vessels. The cytokine was applied uniformly
in solution at embryonic day 7 (E7) to the CAMs of quail embryos cultured in
petri dishes. After 24 h the rate of arterial growth was inhibited by as much as
105% as a function of increasing TGF-beta1 concentration. Inhibition of the rate
of angiogenesis in the arterial tree by TGF-beta1 relative to controls was
measured in digital images by three well-correlated, computerized methods. The
first computerized method, direct measurement by the computer code VESGEN of
vascular morphological parameters according to branching generations G(1) through
G(>/=5), revealed that TGF-beta1 selectively inhibited the increase in the number
density of small vessels, N(v>/=5) (382 +/- 85 cm(-2) for specimens treated with
1 microg TGF-beta1/CAM for 24 h, compared to 583 +/- 99 cm(-2) for controls), but
did not significantly affect other parameters such as average vessel length or
vessel diameter. The second and third methods, the fractal dimension (D(f)) and
grid intersection (rho(v)), are statistical descriptors of spatial pattern and
density. According to D(f) and rho(v), arterial density increased in control
specimens from 1.382 +/- 0.007 and 662 +/- 52 cm(-2) at E7 (0 h) to 1.439 +/-
0.013 and 884 +/- 55 cm(-2) at E8 (24 h), compared to 1. 379 +/- 0.039 and 650 +/
111 cm(-2) for specimens treated with 1 microg TGF-beta1/CAM for 24 h. TGF-beta1
therefore regulates vascular pattern and the rate of angiogenesis in a unique
"fingerprint" manner, as do other major angiogenic regulators that include VEGF,
FGF-2 (bFGF), and angiostatin. TGF-beta1 did not stimulate angiogenesis
significantly at low cytokine concentrations, which suggests that this quail CAM
model of angiogenesis is not associated with an inflammatory response.
PMID- 10684729
TI - Heterogeneity in cytosolic calcium regulation among different microvascular
smooth muscle cells of the rat retina.
AB - Rat retinae were dissociated to yield intact microvessels 7 to 42 microm in
diameter. These were loaded with fura-2 AM and single fragments anchored down in
a recording bath. Intracellular Ca(2+) levels from 20- to 30-microm sections of
vessel were estimated by microfluorimetry. The vessels studied were identified as
metarterioles and arterioles. Only the microvascular smooth muscle cells loaded
with fura-2 AM and changes in the fluorescence signal were confined to these
cells: Endothelial cells did not make any contribution to the fluorescence signal
nor did they contribute to the actions of the drugs. Caffeine (10 mM) or elevated
K(+) (100 mM) produced a transient rise in cell Ca(2+) in the larger vessels
(diameters >18 microm) but had no effect on smaller vessels (diameters <18
microm). Rises in cell Ca(2+) were accompanied by a rapid ( approximately 2 s to
peak) contraction followed by relaxation. Caffeine and K(+) responses were
blocked by ryanodine (10 microM) and nifedipine (1 microM), respectively. In all
the vessels tested, vasopressin (arginine, 10 nM) elicited a transient increase
in cell Ca(2+) and a constriction, irrespective of the diameter of the vessel.
All vessels tested also responded to endothelin-1 (1-10 nM) through an Et(A)
receptor to produce a transient rise in cell Ca(2+) followed by a plateau phase
of elevated Ca(2+) and a constriction. In contrast to the transient effects of
vasopressin, caffeine, and K(+), the cell Ca(2+) remained elevated (>30 min) on
washing out the endothelin and the vessel failed to relax. These results
demonstrate heterogeneity between smaller and larger retinal vessels with regard
to Ca(2+) mobilisation and homogeneity with respect to the actions of vasoactive
peptides.
PMID- 10684730
TI - The effect of treatment with low dose ACE inhibitor and/or diuretic on coronary
microvasculature in stroke-prone spontaneously hypertensive rats.
AB - Angiotensin II is considered to have angiogenic properties. Nevertheless, several
authors reported an increase in coronary capillary density after treatment with
ACE inhibitors. The aim of the present study was to evaluate the effect of
treatment with low doses of ACE inhibitor perindopril, low doses of the diuretic
indapamide, or a combination of the two on microvascular structure in hearts from
stroke-prone spontaneously hypertensive rats (SHR-sp). Young adult male SHR
treated with indapamide (0.24 mg/kg/day), perindopril (0.76 mg/kg/day), or both
were compared with untreated animals after 8 or 14 weeks of treatment. Survival
of SHR-sp was significantly increased after treatment. Only perindopril alone or
in combination with indapamide significantly decreased blood pressure and cardiac
mass. Treatment also significantly increased capillary and myocyte densities but
arteriolar density tended to decrease. External and internal diameters
significantly increased in treated animals while arteriolar thickness remained
the same. Thus, thickness in vessels of the same size was the greatest in
untreated animals, followed by indapamide- and perindopril-treated rats with the
thinnest walls in rats with combined treatment, and the treatment resulted in a
significant increase in the lumen to wall ratio. Capillary and arteriolar growth
responses in treated animals seem to indicate that the two are independently
regulated processes. Treatment with indapamide alone at this dosage did not
significantly influence most responses but in combination with perindopril it
strengthened the effect of perindopril.
PMID- 10684731
TI - Reduced renal mass hypertension, but not high salt diet, alters skeletal muscle
arteriolar distensibility and myogenic responses.
AB - The effects of high salt diet and reduced renal mass hypertension (RRM-HT) on
skeletal muscle arteriolar distensibility and myogenic responses were
investigated in male Sprague-Dawley rats. Rats were enclosed in an air-tight box
with the in situ cremaster muscle exteriorized and viewed via television
microscopy. Normotensive rats were fed low salt (0.4% NaCl) or high salt (4.0%
NaCl) diet and RRM-HT rats were fed high salt diet for 4-6 weeks. With the
cremaster muscle superfused with either physiological salt solution (for myogenic
responses) or Ca(2+)-free physiological salt solution (for arteriolar
distensibility), box pressure (and therefore, intravascular pressure) was
increased in 5 mm Hg increments to a maximum of +30 mm Hg. The myogenic responses
of arterioles were not altered by high salt diet, but were enhanced with RRM-HT.
Arteriolar distensibility was not affected by high salt diet, but was reduced in
RRM-HT rats compared to either normotensive rat group. These data suggest that
high salt diet does not significantly alter either myogenic responses or the
distensibility of rat cremasteric arterioles. However, RRM-HT enhances myogenic
responses of these vessels while reducing arteriolar distensibility. The impact
of these effects must be taken into account when interpreting data describing
alterations in skeletal muscle microvessel reactivity for animals on high salt
diet or with RRM hypertension.
PMID- 10684732
TI - Effect of vascular endothelial growth factor on cultured endothelial cell
monolayer transport properties.
AB - Vascular endothelial growth factor (VEGF) is a potent enhancer of microvascular
permeability in vivo. To date, its effects on hydraulic conductivity (L(p)) and
diffusive albumin permeability (P(e)) of endothelial monolayers have not been
thoroughly assessed in vitro. We hypothesized that VEGF affects endothelial
transport properties differently depending on vessel location and endothelial
phenotype. Using three well-established endothelial cell culture models-human
umbilical vein endothelial cells (HUVECs), bovine aortic endothelial cells
(BAECs), and bovine retinal microvascular cells (BRECs)-grown on porous,
polycarbonate filters we were able to produce baseline transport properties
characteristic of restrictive barriers. Our results show 3.1-fold and 5.7-fold
increases in endothelial L(p) for BAEC and BREC monolayers, respectively, at the
end of 3 h of VEGF (100 ng/ml) exposure. HUVECs, however, showed no significant
alteration in L(p) after 3 h (100 ng/ml) or 24 h (25 ng/ml) of incubation with
VEGF even though they were responsive to the inflammatory mediators, thrombin (1
U/ml; 27-fold increase in L(p) in 25 min) and bradykinin (10 microM; 4-fold
increase in L(p) in 20 min). Protein kinase C (PKC) and nitric oxide (NO) are
downstream effectors of VEGF signaling. BAEC L(p) was responsive to activation of
NO (SNAP) and PKC (PMA), whereas these agents had no effect in altering HUVEC
L(p). Moreover, BAECs exposed to the PKC inhibitor, staurosporine (50 ng/ml),
exhibited significant attenuation of VEGF-induced increase in L(p), but
inhibition of nitric oxide synthase (NOS) with L-NMMA (100 microM) had no effect
in altering the VEGF-induced increase in L(p). These data provide strong evidence
that in BAECs, the VEGF-induced increase in L(p) is mediated by a PKC-dependent
mechanism. Regarding diffusive albumin P(e), at the end of 3 h, BAECs and BRECs
showed 6.0-fold and 9. 9-fold increases in P(e) in response to VEGF (100 ng/ml),
whereas VEGF had no significant effect after 3 h (100 ng/ml) or 24 h (25 ng/ml)
in changing HUVEC P(e). In summary, these data indicate that VEGF affects
endothelial transport properties differently depending on the vessel type and
that differences in cell signaling pathways underlie the differences in VEGF
responsiveness.
PMID- 10684733
TI - Assessment of angiogenesis and tumor growth in conscious mice by a fluorimetric
method.
AB - Angiogenesis and tumor growth in conscious mice have been determined using the
kinetics of appearance of a fluorescent tracer in the bloodstream after
application to subcutaneously implanted sponges bearing tumor cells. The
functional parameter expressed in terms of half-time (t(1/2); time taken for the
fluorescence to reach 50% of the peak in the systemic circulation), which is
inversely proportional to blood flow, showed that in the tumor-free implants
t(1/2) values decreased from 11.55 +/- 1 min at day 1 to 5.7 +/- 0. 44 min by day
14. In the tumor-bearing implants, this process was accelerated and maximum
vascularization was achieved by day 7 (3 days after tumor cell inoculation).
Increases in t(1/2) values were observed at days 10 and 14, which paralleled the
tumor growth as indicated by wet weight. The hemoglobin content (microg Hb/mg wet
weight) in the tumor-free group increased during the 14-day period. In contrast,
in the tumor-bearing implants. Hb concentration decreased per unit of tissue
weight. Dexamethasone treatment for 13 days prevented fibrovascular tissue
infiltration in tumor-free implants, but was unable to delay tumor growth,
indicating that this procedure can be used to exclude the inflammatory reaction
induced by the implantation technique, thus allowing tumor angiogenesis to be
studied without the confounding influence of the host inflammatory cells. The
results of our experimental observation indicate the suitability of this
combination of techniques for analyzing angiogenesis induced by tumor cells and
several hemodynamic features of Ehrlich tumor growth in awake animals.
PMID- 10684734
TI - Vascular endothelial growth factor regulates both apoptosis and angiogenesis of
choriocapillaris endothelial cells.
PMID- 10684735
TI - A histomorphometric observation of flows in cortical bone under dynamic loading.
AB - Ferritin was used as a histological marker for interstitial fluid flows in four
goats. Two transcortical pins were inserted into each tibia mediolaterally-one at
the proximal side and one at the distal side of the diaphysis. For the
experimental limb, dynamic loading was applied to the pins on the lateral side.
The contralateral limb was used as control. Ferritin was injected into the
nutrient arteries feeding the two tibiae. The goat was then euthanized
immediately. Undecalcified slides of the tibial cortical bone from both the
experimental and the control limbs were studied histologically. Percentages of
Haversian systems marked with ferritin halos and the average radial distance of
ferritin transudation away from the Haversian canals were assessed. Results for
the medial and lateral sides of both the experimental and control tibiae were
reported. Significant differences in the ferritin transudation distance were
found between the experimental and the control tibia (P < 0.005) and between the
medial and the lateral sectors (P < 0.05). The approach documented in this paper
could be used to address systematically how external loading might affect the
transport phenomena in cortical bone.
PMID- 10684736
TI - Assessment of continuous skeletal muscle blood flow during exercise in humans.
AB - The ability to measure regional blood flow from exercising skeletal muscles is of
great interest. However, noninvasive techniques such as venous occlusion
plethysmography and pulsed Doppler duplex ultrasonography only allow
determination of blood flow at rest. The aim of our study was to investigate the
influence of position on continuous measured skeletal muscle blood flow response
in the upright and supine positions during graded maximal exercise by means of
the local (133)Xenon washout technique with portable CdTe(Cl) detectors. Fifteen
healthy subjects (8 women and 7 men, mean age 46 +/- 11 years) performed graded
maximal bicycle exercise in both supine and upright positions in random order on
2 subsequent days. Blood flow in the musculus tibialis anterior was measured
using the local (133)Xenon washout technique. A total of 55-110 MBq of (133)Xenon
dissolved in isotonic saline was injected intramuscularly and the gamma emission
was registered by light-weight portable CdTe(Cl) detectors. During supine
exercise skeletal muscle blood flow increased continuously with increasing work
load. However, during upright exercise blood flow increased only at the initial
three work loads, then it decreased gradually. Immediately after exercise blood
flow returned to preexercise values for both positions. The skeletal muscle blood
flow at maximum work load for each subject was 74% (relative flow values) (P <
0.05) higher in the supine compared with the upright position. There was no
significant difference in absolute or relative blood flow values at similar time
points. Exercise time was longer in the supine (1345 +/- 548 s) compared with the
upright position (1148 +/- 453 s) (P < 0.005). The local (133)Xenon washout
technique with portable CdTe(Cl) detectors allows continuous determination of
skeletal muscle blood flow during graded bicycle exercise in supine and upright
positions. Furthermore, blood flow at maximum work load and exercise time was
increased in supine compared with upright exercise.
PMID- 10684737
TI - Patterns of conducted vasomotor response in the mouse.
PMID- 10684738
TI - Erythrocytes enhance lymphocyte rolling and arrest in vivo.
PMID- 10684739
TI - Altered structure and mechanics of skeletal muscle arteries with high-salt diet
and reduced renal mass hypertension.
PMID- 10684740
TI - Child pedestrian injury prevention project: student results.
AB - BACKGROUND: Few comprehensive pedestrian safety interventions for primary-school
age children have been developed and evaluated. This paper reports the impact of
the 3-year (1995-1997) Child Pedestrian In jury Prevention Project (CPIPP) on a
cohort of 1603 children followed from age 6 to 9 years. This multicomponent
project comprised an educational intervention for students, their parents and
teachers, and the local community, as well as several environmental
interventions. The primary aim of CPIPP was to improve children's road-related
behavior and to enhance the safety of their road environment. METHODS: Three
communities were assigned to the treatment conditions: (1) high-education,
community, and environmental interventions; (2) moderate-education intervention
only; and (3) comparison (usual road safety education). Children's pedestrian
knowledge and road crossing and playing behaviors were assessed using a pre- and
posttest self-report questionnaire. Their self-reported road crossing behaviors
were validated using an observational schedule and brief interview. RESULTS:
Children in the high and moderate intervention groups were significantly more
likely to cross the road with adult supervision (P = 0.013) and play away from
the road (P = 0.000) than the comparison group. No differences were detected in
children's pedestrian safety knowledge between the intervention and comparison
groups. CONCLUSIONS: While several methodological limitations may have influenced
the study outcomes, these data nonetheless indicate that in the study sample the
CPIPP educational intervention deaccelerated the natural increase in children's
pedestrian-related risk behavior.
PMID- 10684741
TI - Carpal tunnel syndrome. A message from preventive medicine and your physician
PMID- 10684742
TI - Leisure-time, occupational, and household physical activity among professional,
skilled, and less-skilled workers and homemakers.
AB - BACKGROUND: Adults in lower status occupations are at higher risk of premature
cardiovascular disease, for which physical inactivity is a major risk factor.
While lower rates of leisure-time physical activity have been found to be
associated consistently with lower income and education levels, the association
between occupational and home-based physical activity with membership of
different occupational categories is not well understood. METHODS: An urban
representative population data set derived from a self-completion questionnaire
was used to examine both self-reported leisure-time physical activity and a
combined measure of occupational/home-based physical activity of adult less
skilled, skilled, and professional workers and homemakers (3795 males; 4140
females). chi(2) analyses, ANOVA, and logistic regressions were used to examine
the associations between occupational group membership and physical activity.
RESULTS: After adjustment for age, body mass index, education, country of birth,
marital status, and smoking, less-skilled workers were less likely to report any
form of leisure-time physical activity. However, occupational category was not a
strong predictor of participation in combined vigorous occupational/home physical
activity. Homemakers and those in lower status occupations were less likely to
report participation in vigorous leisure-time physical activity sufficient for
cardiorespiratory fitness. With the inclusion of time spent in combined vigorous
occupational/home physical activity, there was no longer an association of
activity with occupational status for males. However, for females the association
remained. CONCLUSIONS: The assessment of occupational and household physical
activity in addition to leisure-time activity may be important for understanding
associations between occupational categories, physical activity, and increased
levels of health risk and for the development of physical activity promotion
strategies.
PMID- 10684743
TI - A cross-cultural consumer-based decision aid for screening mammography.
AB - BACKGROUND: "Women should have mammograms" is the usual perspective of
educational interventions about screening. The perspective that "women should be
informed" about potential risks and benefits so they can make value- and evidence
integrated personal decisions has recently been advocated. However, this
perspective has not previously been operationalized. We developed an evidence
based cross-cultural mammography decision aid (MDA), for European American and
Mexican American women who are 50-70 years old, at average risk of breast cancer,
of varying educational levels, and English- or Spanish-speaking. METHODS: MDA
development included: (1) content development by a multidisciplinary team and lay
women and (2) testing for validity and reliability. Four parts include: (1)
introduction; (2) information about logistics (cost, time, discomfort) and risks
(sequelae of false-positive or negative results; (3) probability of developing
breast cancer; and (4) benefit of mammography regarding breast cancer outcomes
(e.g., death and recurrence). We assessed reliability (stability of decisions
with the same information) after 1-2 weeks. We assessed validity (comprehension
of information) quantitatively (probabilities were changed to see whether
preferences changed predictably) and qualitatively (focus groups, standardized
probes for comprehension). Subjects were a convenience sample of 49 European
American (50-81 years old) and 54 Mexican American (49-89 years old) women from
administrative staff at a medical school, the waiting room of an indigent primary
care clinic, and a community center. RESULTS: Reliability was 100%. In
quantitative validity testing, 22 of 28 women (89%) changed preference as
predicted with changed probabilities. Comprehension was confirmed qualitatively
in all phases of testing with both Spanish and English versions. CONCLUSION: The
decision aid is valid and reliable in English and Spanish for southwestern
Mexican American and European American women at average risk of breast cancer,
including those of low educational levels.
PMID- 10684744
TI - Cost-benefit analysis of sustained-release bupropion, nicotine patch, or both for
smoking cessation.
AB - BACKGROUND: The nicotine transdermal patch (NTP) has been shown previously to be
a cost-effective smoking cessation intervention. This is the first economic
analysis comparing the NTP with the only non-nicotine-containing pharmacological
intervention, bupropion HCl. METHODS: Decision-tree analysis, based on a
previously published cost-benefit smoking-cessation model, was used to determine
the optimal treatment from the standpoint of costs versus benefits, from the
employer's perspective. Base-case probabilities of successful quitting in our
model came from clinical trial point-prevalence data at the end of a 1-year
follow-up study (N = 893) comparing placebo, bupropion, NTP, and bupropion/NTP in
combination, administered along with minimal counseling. Sensitivity analyses
were performed to determine the effects of variations in base-case assumptions
regarding the monetary benefits that would accrue if an intervention were
successful, probabilities of quitting, drug costs, cost of lost work time for a
health care provider visit, and cost of the visit itself. RESULTS: The analysis
showed that bupropion is more cost-beneficial than either NTP or bupropion/NTP,
with a net benefit in the first post-quit year of up to $338 per employee who
attempts to quit compared with $26 for NTP, $178 for the two in combination, and
$258 for placebo. These results were robust to most plausible variations in the
assumptions used in the model. One exception was the monetary benefit of
successful intervention (assumed in the base-case to be $1,654). If this benefit
were actually less than $1, 112, placebo (i.e., minimal counseling with no
pharmacological intervention) would be more cost-beneficial than any of the
active treatments. CONCLUSION: From an employer's perspective, bupropion 300
mg/day for 9 weeks is a more cost-beneficial smoking cessation intervention than
the nicotine patch, and under most scenarios, bupropion is also more cost
beneficial than placebo.
PMID- 10684745
TI - Associations between exercise and health behaviors in a community sample of
working adults.
AB - BACKGROUND: The present study examined the associations between leisure-time
exercise and a range of health behaviors and reports of illness and injury in a
sample of community working adults. METHODS: The study population included 4907
women and 4136 men who completed surveys in 24 worksites in the Minneapolis-St.
Paul metropolitan area. RESULTS: Participants in the study were ranked by gender
according to their exercise score and grouped into quartiles. Women and men in
the highest activity quartiles were more highly educated and were younger. High
activity men were more likely to be unmarried. Higher levels of leisure-time
exercise were positively associated with seat belt use and inversely related to
smoking, dietary fat intake, reported stress, and obesity. In men only, leisure
time exercise was related to greater reports of injuries resulting in restriction
of usual activities. In women only, leisure-time exercise was positively
associated with daily alcohol use. Most of the significant associations were seen
in the two highest quartiles of exercise. CONCLUSIONS: These findings suggest
that associations between leisure-time exercise and health behaviors occur at the
higher levels of exercise and interventions may need to promote this higher level
of leisure-time exercise to impact overall public health.
PMID- 10684746
TI - Vegan diet-based lifestyle program rapidly lowers homocysteine levels.
AB - BACKGROUND: Plasma homocysteine levels have been directly associated with cardiac
disease risk. Current research raises concerns as to whether comprehensive
lifestyle approaches including a plant-based diet may interact with other known
modulators of homocysteine levels. METHODS: We report our observations of
homocysteine levels in 40 self-selected subjects who participated in a vegan diet
based lifestyle program. Each subject attended a residential lifestyle change
program at the Lifestyle Center of America in Sulphur, Oklahoma and had fasting
plasma total homocysteine measured on enrollment and then after 1 week of
lifestyle intervention. The intervention included a vegan diet, moderate physical
exercise, stress management and spirituality enhancement sessions, group support,
and exclusion of tobacco, alcohol, and caffeine. B vitamin supplements known to
reduce blood homocysteine levels were not provided. RESULTS: Subjects' mean
homocysteine levels fell 13%: from 8.66 micromol/L (SD 2.7 micromol/L) to 7.53
micromol/L (SD 2.12 micromol/L; P < 0.0001). Subgroup analysis showed that
homocysteine decreased across a range of demographic and diagnostic categories.
Conclusions. Our results suggest that broad-based lifestyle interventions
favorably impact homocysteine levels. Furthermore, analysis of Lifestyle Center
of America program components suggests that other factors in addition to B
vitamin intake may be involved in the observed homocysteine lowering.
PMID- 10684747
TI - Black/white differences in relative weight and obesity among girls: the Bogalusa
Heart Study.
AB - BACKGROUND AND OBJECTIVE: Although black women have a higher prevalence of
overweight and obesity than do white women, it is unclear if a similar pattern
exists among youths. We therefore examined the development of black/white
differences in relative weight and adiposity among 5 to 17-year-old girls.
METHODS: Cross-sectional analyses of 4542 black and 4542 white girls who were
examined between 1973 and 1994. Quetelet Index (kg/m(2)), Rohrer Index
(kg/m;s(3)), and height-adjusted weight were used as measures of relative weight,
and subscapular and triceps skinfolds as measures of adiposity. Breast
development was used as an index of sexual maturation. RESULTS: On average, black
girls were 1 to 3 kg heavier than were similarly aged white girls, and before
adolescence, they were 2 to 3 cm taller. After adjusting for differences in
height, the mean relative weight of black girls was consistently greater than
that of white girls only after age 13; furthermore, sexual maturation was a
stronger correlate of relative weight among black girls than among white girls.
Comparable differences were seen for the subscapular skinfold thickness, but
white girls consistently had a thicker mean triceps skinfold than did black
girls. CONCLUSION: Sexual maturation should be considered in comparisons of
relative weight and obesity among youths, and as compared with white girls, black
girls do not have a higher mean relative weight until adolescence. The use of
different indices of overweight and adiposity can lead to contrasting results,
with simple comparisons of Quetelet Index tending to overstate the relative
weights of taller children.
PMID- 10684748
TI - A randomized controlled trial of a clinic-based support staff intervention to
increase the rate of fecal occult blood test ordering.
AB - BACKGROUND: Colorectal cancer is the second most common fatal malignancy in the
United States. Early detection using fecal occult blood tests has been shown to
reduce mortality, but these tests are underutilized among those eligible for this
screening. Attempts to increase use of fecal occult blood tests in eligible
populations have focused on the provider, patient, or system. But none have
examined whether a support-staff intervention is effective in achieving this aim.
We therefore conducted a randomized controlled trial to test the impact of
authorizing support staff to order fecal occult blood tests in a general internal
medicine clinic organized into four teams. METHODS: A total of 1,109 patients
were included in the study, 545 of whom were in the two teams randomized to
treatment. Univariate and multivariate regression analyses were used to evaluate
the impact of the intervention. RESULTS: The intervention resulted in
significantly more fecal occult blood test ordering in the treatment group than
in the control group for all patients (52% vs 15%, P < 0.001). Treatment fecal
occult blood test cards were returned as frequently as the control cards for all
patients (44% vs 48%, P = 0.571). CONCLUSION: Delegation of selected screening
tasks to support staff can enhance patient access to preventive care.
PMID- 10684750
TI - Publishers announcement.
PMID- 10684749
TI - Trends in plasma cholesterol levels in the atherosclerosis risk in communities
(ARIC) study.
AB - BACKGROUND: Data from the Atherosclerosis Risk in Communities (ARIC) cohort study
were examined both cross-sectionally and intraindividually to confirm recent
findings from population-based studies showing a decline in total cholesterol
(TC) levels in the United States. METHODS: For the cross-sectional analysis, mean
plasma TC levels from 15,792 participants aged 45-64 at baseline visit, and who
were selected randomly from four U.S. communities, were examined for each year
covered by the first cohort visit (1987, 1988, and 1989). Ninety-three percent of
the cohort participants returned for the follow-up visit (1990, 1991, and 1992),
and were included in the assessment of intraindividual TC trends. RESULTS: Both
mean TC and prevalence of hypercholesterolemia (defined as plasma cholesterol
concentration >/=240 mg/dl) consistently declined over the 3 years covered by
visit 1 for all age-gender-race groups. For 1987, 1988, and 1989, mean TC values
(mg/dl) were, respectively, 220.3, 216.7, and 214.1 (annual average change,
1.4%, P < 0.001). For these same years, hypercholesterolemia prevalence rates
were 30. 0, 27.8, and 25.3% (annual average change, -7.8%, P < 0.001). The mean
plasma TC also decreased within individuals between the two visits across race,
gender, and age decade categories. With the exception of black men, this decline
was more marked for older than younger subjects, but no consistent differences
were seen between the racial groups. However, in whites, decreases were greater
for men than for women. Expected results were seen when these changes were
correlated with changes in cardiovascular risk factors between the two visits.
CONCLUSION: The current study results are consistent with those of previous
studies, and confirm the notion that preventive programs appear to be effective
in reducing mean population TC levels.
PMID- 10684751
TI - Sialography of sheep parotid and mandibular salivary glands.
AB - The anatomy of ovine salivary glands was studied on cadaver heads. The mandibular
duct enters the oral cavity on the ventral surface of sublingual caruncles, which
are located medial to the orifice of the ventral sublingual gland duct. The
parotid gland duct enters the oral cavity on the cheek opposite the upper 2nd
molar. Prior to applying sialography to live animals, the procedure was carried
out on cadaver heads then the live animals were sedated, the mandibular and
parotid ducts catheterized and contrast medium was injected into each gland.
Lateral radiographs were made immediately after the injection. The normal sheep
mandibular and parotid salivary glands have a multilobular appearance in cadaver
heads, but in live animal only the ducts and their smaller branches could be
identified. The mean diameter of mandibular and parotid duct were 1.4+/-0.3 mm
and 3. 1+/-1.0 mm respectively. The monostomatic sublingular gland had a slender
shape in the sialogram. In conclusion sialography of mandibular, parotid and
sublingual salivary glands in sheep is practical and can be helpful in diagnosis
of pathological conditions of these glands.
PMID- 10684752
TI - Simultaneous serological evidence of Actinobacillus pleuropneumoniae, PRRS,
Aujeszky's disease and influenza viruses in Spanish finishing pigs.
AB - A total of 198 pigs with tachypnoea and temperature >/= 40 degrees C were
selected on a Spanish finishing unit, and their sera were examined for antibodies
to Actinobacillus pleuropneumoniae (App), porcine reproductive and respiratory
syndrome virus (PRRSV), Aujeszky' disease virus (ADV), and swine influenza virus
(SIV). Eighty-nine point nine per cent of the pigs were seropositive to App, 88.6
per cent to PRRS, 73.0 per cent to ADV, and 30.6 per cent to SIV. Thirty-one pigs
(15.6 per cent) were seropositive for App, PRRSV, ADV and SIV, and only one (0.5
per cent) was seronegative for all. Statistical association was assessed for dual
infections but it was not found in any case (P > 0.05). Other parameters
(dyspnoea, nasal discharge and coughing) were also recorded, and no significant
associations between them and the presence of antibodies against any of the four
infections was found.
PMID- 10684754
TI - Detection of Lawsonia intracellularis in the tonsils of pigs with proliferative
enteropathy.
AB - The presence of Lawsonia intracellularis, the obligate intracellular bacterium
causing proliferative enteropathy (PE), in the tonsils of pigs as a locus for
infection or extraintestinal occurrence of the bacterium was investigated by PCR
and immunohistochemistry. Tonsillar occurrence of L. intracellularis could be
part of the pathogenesis of PE and an important risk factor in the spread of the
disease. L. intracellularis was detected by only PCR in the tonsils of 2/32 pigs
without PE at necropsy but with a clinical history of diarrhoea and detection of
the bacterium in faeces 1 to 3 weeks prior to necropsy but not in four pigs with
moderate PE lesions. However, L. intracellularis was detected in the tonsils of
4/9 pigs with PE complicated with necroses and in 4/4 pigs with proliferative
haemorrhagic enteropathy in which L. intracellularis antigen also was
demonstrated in tonsillar macrophages and as intact bacteria in the lumen of the
crypts. The results show that L. intracellularis is detectable in the tonsils of
pigs and that the tonsillar presence of L. intracellularis appears to be
correlated to the severity of the intestinal lesions possibly as a result of
local retention and not as part of the pathogenesis of PE.
PMID- 10684753
TI - Oestrogen and progesterone receptors in feline fibroadenomatous change: an
immunohistochemical study.
AB - The distribution of oestrogen and progesterone receptors was analysed in 18 cases
of feline fibroadenomatous change (FFAC) using commercially available specific
monoclonal antibodies and the Avidin-biotin peroxidase complex technique on
formalin-fixed, paraffin-embedded tissue. In all cases of FFAC, progesterone
receptors were detected either in epithelial cells (mostly suprabasal) or in
epithelial and stromal cells. Oestrogen receptors were detected in approximately
half of these cases, in suprabasal or luminal epithelial cells exclusively.
Myoepithelial cells lacked both oestrogen and progesterone receptors. The
techniques used have identified the specific cellular distribution of steroid
hormones receptors in this hormone-dependent lesion of the feline mammary gland.
The results confirm those of previous biochemical analyses with respect to
progesterone receptors and add new data concerning the possible involvement of
oestrogen receptors and stromal fibroblasts in the hormonal control and
development of the lesion.
PMID- 10684755
TI - Optimal conditions for simultaneous measurement of platelet aggregation and ATP
secretion in canine whole blood.
AB - This paper describes the optimal conditions for simultaneous evaluation of
platelet aggregation and secretion capacity in canine whole blood using a Whole
Blood Lumi-Aggregometer (Chrono-Log Corporation, Havertown, Pensylvania). For
this purpose, the potential influence of several parameters was investigated
using collagen, adenosinediphosphate (ADP), arachidonic acid (AA) and thrombin as
platelet agonists. Results indicate that optimal experimental conditions to
obtain reliable results include: allowing blood samples to stand at room
temperature 60 minutes after blood collection, analysing samples within 3 hours
from time of collection, adjusting platelet numbers to a final concentration of
150 000 microl(-1)and mixing the sample with isotonic saline (1:1) before adding
the platelet agonist. The use of different platelet agonists offers variable
results: collagen (0.5, 1 and 5 microg ml(-1)) is suitable for simultaneous
platelet aggregation and adenosintriphosphate (ATP) secretion measurements; 1 UI
ml(-1)of thrombin induced maximum ATP secretion;AA (0.5 and 1 mM) and ADP (5, 10
and 25 microM) did not give consistent results. The method described in this
study has important clinical applications since it allows easy and quick platelet
function evaluation in pathologic states.
PMID- 10684756
TI - Determination of intraspecies variations of the V2 region of the 16S rRNA gene of
Streptococcus equi subsp. zooepidemicus.
AB - The 16S rRNA gene of 39 S. equi subsp. zooepidemicus strains and two S. equi
subsp. equi strains was amplified by polymerase chain reaction and subsequently
digested with the restriction enzyme Hinc II. A restriction profile with two
fragments with sizes of 1250 bp and 200 bp could be observed for both S. equi
subsp. equi strains and for 30 of the 39 S. equi subsp. zooepidemicus strains
indicating a sequence variation within the V2 region of the 16S rRNA gene of the
remaining nine S. equi subsp. zooepidemicus isolates. A segment of the 16S rRNA
gene including the hypervariable V2 region of 11 S. equi subsp. zooepidemicus and
two S. equi subsp. equi could be amplified by PCR and sequenced. The sequence of
the V2 region of eight S. equi subsp. zooepidemicus strains appeared to be
identical or almost identical to the sequence of the two S. equi subsp. equi
strains. The sequence of the remaining three S equi subsp. zooepidemicus strains
differed significantly from the sequence of S. equi subsp. equi. These
differences allowed a division of S. equi subsp. zooepidemicus strains into two
16S rRNA types and might possibly have consequences for the taxonomic position of
these phenotypically indistinguishable strains of one subspecies. A molecular
typing could additionally be performed by amplification of the gene encoding the
16S-23S rRNA spacer region. A single amplicon of the spacer gene of 1100 bp could
be observed for one S. equi subsp. zooepidemicus, an amplicon of 950 bp for two
S. equi subsp. equi strains and 10 S. equi subsp. zooepidemicus strains, a
amplicon of 780 bp for 27 S. equi subsp. zooepidemicus strains and a single
amplicon of 600 bp for one S. equi subsp. zooepidemicus strain. The variations of
the V2 region of the 16S rRNA gene and the size variations of the 16S-23S rRNA
spacer gene were not related to each other. Both variations could be used for
molecular typing of this species, possibly useful in epidemiological aspects.
PMID- 10684757
TI - An interobserver and intraobserver study of buccal mucosal bleeding time in
Greyhounds.
AB - Two observers experienced with the buccal mucosal bleeding-time technique using a
standardised device (Surgicutt) performed the test on 20 Greyhounds, to evaluate
interobserver and intraobserver repeatability. The interobserver and
intraobserver repeatability were both about 2 minutes. The results indicated
that, for any two readings within a dog, the buccal mucosal bleeding time may
differ by up to +/- 2 minutes. A single reading was accurate to within +/- 80
seconds. Sixty-one Greyhounds were used to establish a reference interval for the
buccal mucosal bleeding time, and to assess the relationship between the buccal
mucosal bleeding time and plasma von Willebrand factor concentration. The mean
was 129.5 (SD 44.2) seconds. The reference interval was 53 to 235 seconds, which
was slightly lower than non-greyhounds. No significant correlation (r=-0. 18,
P=0.17) between the buccal mucosal bleeding time and plasma von Willebrand factor
concentration was found in the 61 Greyhounds, where plasma von Willebrand factor
concentration was in the range 29 to 160 Canine Units dL(-1).
PMID- 10684758
TI - Mechanics of the respiratory system in healthy newborn calves using impulse
oscillometry.
AB - Arterial blood gases, acid-base balance and respiratory function tests using
impulse oscillometry (IOS) were performed on 40 clinically healthy newborn calves
during the first 24 hours of life to evaluate their respiratory adaptation to
extrauterine life. Gas exchange efficiency of the lung was significantly improved
with time and was accompanied by the correction of the mixed acidosis observed at
birth and by significant changes in respiratory mechanics. Major changes were
detected within the first 6 hours. The significant decrease in resistance (R) and
the increase in reactance (X) with time, demonstrate the improvement in
respiratory mechanics of both upper and lower airways, and reflect the increase
in lung volume, the improved lung tissue elasticity and/or distribution of the
ventilation. Respiratory mechanical, arterial blood gases and acid-base balance
data provided in this study describe a successful respiratory adaptation to
extrauterine life in healthy newborn calves.
PMID- 10684759
TI - Differentiation induction of canine osteosarcoma cell lines by retinoids.
AB - The effect of two retinoids, all- trans and 9- cis retinoic acid, on the
differentiation of three canine osteosarcoma cells (OOS, HOS, and POS) was
examined using markers specifically expressed by phenotypic osteoblasts. Both
retinoids induced morphologic differentiation in all the canine osteosarcoma
cells. Retinoids enhanced cell flattening and spreading, as well as reduction in
cell overlapping. Alkaline phosphatase (ALP) activity and ALP staining was
enhanced in OOS, and HOS cells, but decreased in POS cells. These results may
suggest that OOS and HOS cells have immature osteoblastic properties and POS
cells have mature osteoblastic properties. Retinoids decreased osteocalcin
production in all the osteosarcoma cells. They induced an increase in production
of type I collagen in HOS and POS cells, but a decrease in OOS cells. These
results indicate that retinoids induce differentiation of canine osteosarcoma
cells, resulting in an altered expression of their malignant phenotype.
PMID- 10684760
TI - Presence of p53 mutations in feline neoplasms.
AB - A region from exon 4 to 8 of the tumour suppressor gene p53 was analysed in 60
feline tumours (30 fibrosarcomas, seven malignant histiocytomas, three
lymphosarcomas, five basal cell tumours, five squamous cell carcinomas, two
adenocarcinomas of tubular skin glands, one undifferentiated carcinoma of the
skin, seven mammary carcinomas). Missense mutations were detected in two
fibrosarcomas, one malignant fibrous histiocytoma, the undifferentiated carcinoma
of the skin and one mammary carcinoma. One nonsense mutation was detected in one
fibrosarcoma and one deletion/frameshift-mutation was observed in one squamous
cell carcinoma.
PMID- 10684762
TI - Enteric colonisation following natural exposure to Campylobacter in pigs.
AB - A survey was conducted to establish the prevalence of Campylobacter in pigs from
an integrated commercial hog farm. This study was carried out in four different
groups of pigs: 1) adult gilts (50); 2) pregnant sows (9); 3) piglets at day-of
birth (73); 4) weaned piglets (20). Rectal and/or caecal samples were collected
from each pig. Campylobacter was cultured and enumerated from such samples using
Bolton enrichment broth and Campy-Cephex agar plates. Both biochemical and
serological tests were used to determine Campylobacter species. Gilts had a 76
per cent incidence of Campylobacter with a mean of 76.3 per cent for C. jejuni,
21 per cent for C. coli and 2.6 per cent for C. lari. Pregnant sows had a 100 per
cent incidence of Campylobacter with a mean of 87 per cent for C. jejuni and 13
per cent for C. coli. Newborn piglets had a 57. 8 per cent incidence of
Campylobacter, rising to 100 per cent by the time of weaning. Thus it appears
that pigs, from the day of birth, are highly susceptible to colonisation by
Campylobacter.
PMID- 10684761
TI - Effect of lead on erythrocytic antioxidant defence, lipid peroxide level and
thiol groups in calves.
AB - Fifteen crossbred male calves were exposed to lead for a period of 28 days orally
at the dose rate of 7.5 mg of lead acetate as 0.75 per cent solution kg(-1)body
weight to study its effect on erythrocytic antioxidant defense, lipid peroxide
level and thiol groups. Five calves were given no treatment and served as
unexposed controls. Blood samples were collected before exposure to lead and
thereafter at weekly intervals (ie. on day 7, 14, 21 and 28). Erythrocyte
haemolysate (10 per cent) was prepared and analysed for lipid peroxide level,
activity of Superoxide dismutase (SOD) and catalase. Total, protein-bound and non
protein-bound thiol groups were also measured. Exposure to lead significantly (P
< 0.05) reduced the erythrocytic SOD activity by day 7 and it remained lower
until day 21 followed by a marginal increase on day 28. Catalase activity
declined after an initial compensatory rise on day 7. Erythrocytic lipid peroxide
level was recorded to be significantly (P < 0.05) higher by day 21 and 28 of
exposure. Total, protein-bound and non protein-bound -SH content of erythrocytes
declined. It was concluded that oral exposure of lead reduced the erythrocytic
thiol content and antioxidant defence indicating possible role of free radicals
in pathogenesis of lead toxicity.
PMID- 10684763
TI - Inhibitory effects of 22-oxa-calcitriol and all- trans retinoic acid on the
growth of a canine osteosarcoma derived cell-line in vivo and its pulmonary
metastasis in vivo.
AB - Pulmonary metastasis is a major cause of death and a major obstacle to the
successful treatment of canine osteosarcoma. However, the residual capacity of
the neoplasia for differentiation and its susceptibility to undergo apoptosis may
be used to suppress its growth and metastatic properties. The highly
metastasizing POS (HMPOS) canine osteosarcoma cell line which preferentially
metastasize to the lungs was used to test the possible efficacy of 22-oxa
calcitriol (OCT) and all- trans retinoic acid (ATRA) to inhibit growth and
pulmonary metastasis of the subcutaneously grown osteosarcoma in nude mice.
Treatments in vitro, morphologically elongated and increased alkaline phosphatase
activity and staining of cells. Tumour growth in vivo was inhibited significantly
and the combination treatment of OCT and ATRA (OCT + ATRA) exerted a synergistic
and stronger suppression at concentration of 1.0 microg kg(-1)body weight when
given subcutaneously three times a week for 5 weeks. The subcutaneous tumours of
the control mice consisted of osteoblast-like cells and isolated chondroblast
like cells, but formed several areas of osteoid and increased amount of collagen
tissue in all treated mice. Pinpoint macrometastatic nodules developed only in
all control mice. Micrometastatic nodule developed only in two of six mice
treated with ATRA. However, nodule size and number, and lung wet weight were all
reduced significantly. Metastasis were not seen in the mice treated with OCT or
OCT + ATRA. This study demonstrated that inhibition of growth and pulmonary
metastasis was induced by subcutaneous treatment with these drugs and suggest
that both its differentiating and apoptotic inducing activities may be
responsible for the antitumour effects. These drugs may be useful in the clinic
as an adjunct for the treatment of canine osteosarcoma.
PMID- 10684764
TI - Tissue sources of serum alkaline phosphatase in 34 hyperthyroid cats: a
qualitative and quantitative study.
AB - The concentration of serum alkaline phosphatase (SALP) is commonly elevated in
hyperthyroid cats. Agarose gel electrophoresis, in tris -barbital-sodium barbital
buffer, with and without the separation enhancer neuraminidase, was used to
investigate the sources of the constituent isoenzymes of SALP in serum samples
from 34 hyperthyroid cats, comparing them to sera from five healthy cats and to
tissue homogenates from liver, kidney, bone and duodenum. Contrary to previous
reports, treatment of serum with neuraminidase made differentiation of the
various isoenzymes more difficult to achieve. A single band corresponding to the
liver isoenzyme (LALP) was found in 100 per cent of healthy cats. Eighty-eight
per cent of the hyperthyroid cats showed two bands, corresponding to the liver
and bone (BALP) isoenzymes while 12 per cent showed a LALP band alone. In
hyperthyroid cats, there was a significant correlation between the serum L
thyroxine concentrations and the SALP concentrations. These findings suggest
pathological changes in both bone and liver in most cases of feline
thyrotoxicosis.
PMID- 10684765
TI - Cell mediated and humoral immune responses of white-tailed deer experimentally
infected with Mycobacterium bovis.
AB - The objective of this study was to improve the understanding of immune responses
of whitetailed deer (Odocoileus virginianus) infected with Mycobacterium bovis.
Ten mature, female, white-tailed deer were inoculated by intratonsilar
instillation of 2 x 10(3)or 2 x 10(5)colony-forming units of M. bovis. Lymphocyte
proliferation and humoral response to M. bovis PPD and the M. bovis protein,
MPB70 were measured. Deer were tested for exposure to M. bovis by the comparative
cervical skin test. Biopsy specimens of skin test sites were examined
microscopically and immunohistochemically. The comparative cervical skin test
correctly identified all M. bovis -inoculated deer as exposed to M. bovis.
Lymphocyte proliferative responses to MPB70 were more consistent than responses
to M. bovisPPD in M. bovis -inoculated deer. Antibody responses were more
prominent in deer with disseminated disease than in deer with localised disease.
The cellular components of delayed-type hypersensitivity reactions at skin test
sites were similar to tuberculin reactions in other species. T lymphocytes of the
gamma/delta phenotype were seen in increased numbers in M. bovisPPD injection
sites.
PMID- 10684766
TI - Tissue print hybridisation and reverse transcriptase PCR in the detection of
infectious bursal disease viruses in bursal tissues.
AB - The genome segments of infectious bursal disease viruses (IBDV) in the bursa of
Fabricius from experimently infected chickens or field samples were detected by
tissue print hybridization (TPH) with subsequent reverse transcriptase (RT)-
polymerase chain reaction (PCR). Bursae were imprinted onto nylon membrane and
then hybridized with a cloned digoxigenin (DIG)-labeled cDNA probe. Tissue prints
on nylon membrane were readily distinguished from control prints by color
development and differences in signal intensity. In order to verify the TPH test,
RT - PCR was used to amplify a 643-base pair fragment on the VP 2 gene of IBDV in
the bursa of Fabricius. With all isolates, a c DNA fragment of 643 bp long was
generated as expected and further confirmed the specificity of TPH. Our results
suggest that a large number of field samples or selected tissues can be rapidly
examined by TPH technique when combined with a cloned DIG -labeled c DNA probe.
PMID- 10684767
TI - A tribute to the medical council on alcoholism, its journal and their supporters
as we enter the new millennium
PMID- 10684768
TI - The Medical Council on Alcoholism (MCA) and its journal Alcohol and Alcoholism.
PMID- 10684769
TI - ESBRA: passport for the development of biological research on alcoholism in
Europe.
PMID- 10684770
TI - One hundred years of alcoholism: the Twentieth Century.
AB - The past 100 years witnessed the formation of a disease concept of alcoholism and
a rapid increase in the knowledge of its aetiopathology and treatment options. In
the first half of the century, public sanctions aimed at the abolition of
alcoholism. In the United States, alcohol prohibition was revoked in the economic
turmoil of the Great Depression. In Germany, proposed medical procedures to
reduce the fertility of alcoholics had catastrophic consequences during the
fascist dictatorship. A revived focus on alcoholics as patients with a right to
medical treatment came out of self-organized groups, such as Alcoholics
Anonymous. The current disease concept includes the psychosocial and
neurobiological foundations and consequences of alcoholism. Neurobiological
research points to the dispositional factor of monoaminergic dysfunction and
indicates that neuroadaptation and sensitization may play a role in the
maintenance of addictive behaviour. New treatment options include pharmacological
approaches and indicate that behaviour and motivational therapy and the
attendance of patient groups may equally reduce the relapse risk. The task of the
future will be to apply scientific discoveries in the best interest of the
patients and to support their efforts to be respected like subjects suffering
from other diseases.
PMID- 10684771
TI - Science, practice and patient needs: the work of the Plinius Maior Society.
AB - The Plinius Maior Society is a European multinational, multidisciplinary group of
clinicians and researchers in the alcoholism field, which strives for a
comprehensive care concept in the management of alcoholism and alcohol-related
problems. The Society, using evidence-based medicine, has developed a set of
protocols, in the forms of guidelines, flow-charts, leaflets and booklets, for
use as tools in research on and treatment of alcohol dependence, with a view to
standardize clinical research procedures and to bridge the gap between the
alcoholism researcher, practitioner and patient. These protocols or tools have
been subjected to a review process during their preparation, and further comments
on their validity will be integrated in their updates. Seven protocols have so
far been developed, two of which, 'Guidelines on Evaluation of Treatment of
Alcohol Dependence' and 'Detection and Management of Patients with Psychiatric
and Alcohol Use Disorders', are aimed at the clinical researcher and specialists,
whereas three others [in the form of decision trees (flow-charts)] are aimed at
the general practitioner and other primary health care providers. These are
entitled 'Alcohol Risk Assessment and Intervention in Primary Care', 'Withdrawal
from Alcohol at Home' and 'Brief Intervention in Patients with Alcohol-Related
Problems'. The remaining two tools are booklets aimed at the patient, one to
support initiatives for detection of drinking problems and primary intervention,
namely 'Do you have this Problem? Discuss it with your Doctor!', and the other to
assist the patient in relapse prevention after the early stages of treatment,
namely 'On the Way to Recovery'. The protocols for the general practitioners and
patients have so far been produced in seven European languages, and, as with the
Guidelines, feedback from target users will be collected and incorporated in
future updates. The Society continually seeks to consider areas of clinical
importance for its work and, as it enters the new millennium, it hopes to address
and make a significant contribution to the most pressing problem in the
management of alcohol dependence, namely relapse.
PMID- 10684772
TI - Developmental aspects of intestinal intraepithelial and lamina propria
lymphocytes in the rat following placental and lactational exposure to ethanol.
AB - Fetal and lactational exposure to alcohol can induce impairments to the immune
system and lead to decreased resistance to certain infectious agents.
Morphometric procedures were used to quantify changes induced by maternal ethanol
consumption in the gut-associated lymphoid tissue of rat pups. Rats were pair-fed
with ethanol-containing or isocaloric control liquid diets formulated for
pregnant and lactating animals from day 1 of pregnancy and throughout the
lactation periods. Pups were weaned and placed on control liquid diet on post
natal day 21. Intraepithelial and lamina propria lymphocytes and macrophages were
evaluated on post-natal days 14, 18, and 25. Lower thymus weights were observed
in the ethanol-exposed pups on post-natal days 14 and 18 and lower total
thymocyte counts on post-natal day 14. On post-natal day 14, T cells, T cytotoxic
cells, IgA plasma cells, and macrophages were decreased in the ileal epithelial
and lamina propria areas in the ethanol-exposed, compared to the pair-fed, pups.
No differences for any of the above cell counts were found in the jejunum on post
natal day 14. On post-natal day 18, macrophages were still decreased in the ileum
in the ethanol-treated pups, compared to pair-fed animals. No differences were
found in T cells, T cytotoxic cells, and IgA lymphocytes between groups in either
the jejunum or ileum on post-natal days 18 and 25. This study suggests that fetal
and lactational exposure to ethanol has some effects on the development or influx
of intraepithelial and lamina propria leukocytes and that the changes are most
pronounced in early neonatal life.
PMID- 10684773
TI - Role of Kupffer cells in the release of nitric oxide and change of portal
pressure after ethanol perfusion in the rat liver.
AB - The objective of this study was to elucidate the role of Kupffer cells during the
increase of portal vein pressure caused by ethanol. We measured nitric oxide (NO)
in the perfused rat liver using a commercial NO meter. Ethanol perfusion
increased NO release and portal vein pressure. Gadolinium chloride pretreatment
reduced the increase in portal vein pressure during the early phase of ethanol
perfusion, but did not affect the release of NO after ethanol infusion. These
findings suggest that Kupffer cells play an important role in liver
microcirculation during the early stage of ethanol intake, but that the mechanism
may not be regulated by NO.
PMID- 10684774
TI - Cerebellar Purkinje neurons with altered terminal dendritic segments are present
in all lobules of the cerebellar vermis of ageing, ethanol-treated F344 rats.
AB - Previous studies from this Laboratory have shown that cerebellar Purkinje neurons
(PN) in ageing, ethanol-fed Fischer 344 rats may have terminal dendritic segments
that are longer than in control rats. They also showed that the longer terminal
segments represented a toxic effect of ethanol on PN, because their increase in
length resulted from an ethanol-induced deletion of other terminal dendritic
segments and not from dendritic growth. The purpose of the present study was to
determine whether this effect of ethanol was localized to specific lobules or was
widely distributed within all lobules of the cerebellar vermis. Twelve-month-old
male Fischer 344 rats were treated with a liquid ethanol diet for 48 weeks. Age-
and weight-matched controls were pair-fed with an isocaloric control diet.
Terminal dendritic segments in Golgi-Cox-stained PN in four groups of lobules in
the cerebellar vermis of control and ethanol-fed rats were measured for treatment
related changes in length. Results from these measurements showed that ethanol
exposed PN with significantly longer terminal segments were present in all groups
of lobules, i.e. they were widely distributed and not confined to specific
lobules. Results from these measurements also confirmed in a large sample of
neurons (40 neurons per rat) that the topologically distinct unpaired terminal
segments were characteristically longer than the paired terminal segments in PN
of control and ethanol-fed rats and that both types of terminal segments were
longer in the ethanol-fed rats than in the controls.
PMID- 10684775
TI - Effects of carnosine and related compounds on the stability and morphology of
erythrocytes from alcoholics.
AB - The effects of carnosine and related compounds on erythrocytes from alcoholics
were studied. In their presence, erythrocytes showed an increased ability to
resist haemolysis and showed a more normal morphology, with carnosine and N
acetyl-carnosine being the most effective compounds. These beneficial properties
of the dipeptides do not appear to be directly related to their antioxidant or
buffering properties.
PMID- 10684776
TI - A pilot investigation of the effect of tryptophan manipulation on the affective
state of male chronic alcoholics.
AB - A pilot study was conducted to investigate the hypothesis that dietary tryptophan
manipulation would influence self-report affective status in alcoholic males. No
significant effect of dietary manipulation was observed on the tryptophan/large
neutral amino acids ratio or psychological indices of affect. The notion that
dietary manipulation may be utilized in improving mood state in alcoholic males
was not supported.
PMID- 10684777
TI - Dissociable cognitive impairments in problem drinkers.
AB - Patients in a treatment programme for severe alcohol dependence were tested on a
battery of tests designed to examine organizational and visuo-spatial abilities.
Analysis using a case-study approach indicated independent organizational and
visuo-spatial impairments. An understanding of aetiological factors underlying
these cognitive deficits and implications for treatment are discussed.
PMID- 10684778
TI - Application of cross-impact analysis to the relationship between aldehyde
dehydrogenase 2 allele and the flushing syndrome.
AB - The experimental approach has been used to study successfully the relationship
between the polymorphism of aldehyde dehydrogenase 2 and the flushing syndrome.
In the present study, a probabilistic approach was used to analyse this
relationship. Using cross-impact analysis and experimental data, the probability
of the occurrence of flushing, the extent by which ALDH2*2/*2 enhances flushing
more than ALDH2*1/*2, the extent by which ALDH2*1/*1 enhances non-flushing more
than ALDH2*1/*2, etc. can be calculated. Two examples are given to show the
potential use of cross-impact analysis.
PMID- 10684779
TI - A comparison of substance use between female inmates and female substance
misusers in treatment.
AB - Recent literature documents extensive substance misuse histories among US female
prison inmates. The primary purpose of the present study was to determine whether
histories of personal and familial substance misuse distinguished female inmates
from substance misusers in treatment. After accounting for drug-related offences,
we hypothesized that the inmates would have more extensive histories of personal
and familial substance misuse and that they would have initiated substance use at
an earlier age. Contrary to our expectations, the two samples were similar on
many measures of alcohol and drug use. Similarly, differences in family histories
of substance misuse were not in the predicted direction. As hypothesized,
however, the inmates did report earlier age at onset of drinking. Of particular
clinical relevance was the finding that, despite similar alcohol consumption
levels, inmates reported fewer alcohol-related adverse medical, legal, and
psychosocial consequences than did the treatment sample.
PMID- 10684780
TI - Detoxification from alcohol: a comparison of home detoxification and hospital
based day patient care.
AB - An uncontrolled study was carried out to examine two types of ambulatory care for
patients undergoing detoxification from alcohol. The safety, efficacy, and
acceptability of home detoxification was compared to detoxification within a day
hospital setting. Seventy-nine per cent of home detoxification patients, many of
whom had major alcohol-related problems and were severely dependent on alcohol,
were successfully detoxified at 10 days. The day hospital group overlapped in
severity with the home group and 78% completed detoxification. At 60 days, 45% of
home detoxification patients and 31% of the day hospital group showed significant
improvements in a range of alcohol-related difficulties. Improved outcome was
associated with attendance for further treatment for both groups. Both home and
day hospital detoxifications were viable alternatives to in-patient
detoxification for selected groups of patients.
PMID- 10684781
TI - Suicides of alcohol misusers and non-misusers in a nationwide population.
AB - Alcohol dependence is a risk factor for suicide, and in the general population
alcohol consumption and suicide rates are known to be associated. We investigated
victims with and without alcohol misuse among unselected completed suicides to
explore the role of alcohol misuse in the suicidal process and final act. In a
total 1-year (1987-1988) population of suicides in the National Suicide
Prevention Project in Finland, alcohol-misusing and -non-misusing victims were
compared. On the basis of informant interviews, 35% (n = 349) of included victims
were classified as alcohol misusers and 65% (n = 648) as non-misusers. The
misusers were more often younger, male, divorced or separated and had more often
worked, but were recently unemployed. They had experienced more often recent
adverse life events possibly dependent on their own behaviour, were far more
likely to be alcohol-intoxicated at the time of suicide, and tended to die from
drug overdose. Several characteristics of these predominantly male alcohol
misusers indicated better earlier lifetime psychosocial adjustment compared to
the non-misusers, but more adverse life events close to suicide. Alcohol misuse
is likely to have a deteriorating influence on the life course of those who
eventually succumb to suicide, and its adverse consequences are common in
misusers during the final months.
PMID- 10684782
TI - Combination pharmacotherapy: a mixture of small doses of naltrexone, fluoxetine,
and a thyrotropin-releasing hormone analogue reduces alcohol intake in three
strains of alcohol-preferring rats.
AB - It is common to treat some diseases with more than one medication simultaneously.
Since more than one neurotransmitter system is involved in alcohol-seeking
behaviour, then a therapeutic approach that targets more than one system should
be more effective in reducing alcohol intake than one addressing a single system.
To test this hypothesis, we compared the efficacy of low doses of individual
drugs reported to reduce voluntary alcohol drinking to the efficacy of a mixture
of these agents at the same low doses in reducing alcohol intake in three strains
of alcohol-preferring rats (P, HAD, and Fawn-Hooded). After establishment of a
stable baseline for alcohol intake in a continuous access paradigm, each rat
received separate single i.p. injections of relatively low doses of either
naltrexone (2.0 mg/kg), fluoxetine (1.0 mg/kg), the thyrotropin-releasing hormone
analogue TA-0910 (0.2 mg/kg), a mixture of all three drugs, or the vehicle at
09:30. Each rat received all treatments, with an inter-injection washout period
of at least 3 days. Alcohol and water intakes were measured at 6 and 24 h, and
food intake was measured at 24 h, after the injection. Our results show that
individual drugs did not significantly affect food, water, or alcohol intake.
However, the mixture significantly reduced alcohol intake in all three strains,
but had no effect on food intake. Similar results were obtained when the HAD rats
received an oral dose of the individual drugs or the mixture. When P rats were
given an i.p. injection of the mixture for 10 consecutive days, there was a
continued suppressing effect. These findings show that a combination treatment
designed to target simultaneously serotonergic, dopaminergic, and opioidergic
systems can reduce alcohol intake, even though the doses of the individual drugs
in the mixture are relatively low and ineffective when given singly.
PMID- 10684783
TI - Acute effect of alcohol on androgens in premenopausal women.
AB - The aim of the present study was to investigate the effect of alcohol on androgen
levels among premenopausal women. Eighty-seven women in the mid-cycle phase of
the menstrual cycle, 47 of whom used oral contraceptives (OC+), were included in
the study. The range for reported alcohol consumption was 0-4 drinks/day. The
total testosterone levels were significantly higher after alcohol intake (0.5
g/kg) than after placebo at 45 min and 90 min from the start of drinking among
both OC- and OC+ subjects. This effect was also seen in the free testosterone
fraction. The effect on testosterone was more prominent among OC+ subjects.
Androstenedione levels were significantly lowered and the
testosterone:androstenedione ratio significantly elevated by alcohol among both
OC- and OC+ subjects. No effect of alcohol on dehydroepiandrosterone or
dihydrotestosterone levels was observed. A positive correlation was observed
between the change in testosterone levels and the change in androstenedione
levels during placebo conditions. The correlation was significantly reduced
during alcohol conditions among OC+ subjects, indicating an increased
androstenedione to testosterone conversion. No significant dose (0.34, 0.68 and
1.02 g/kg) or time (45, 90 and 150 min) effects on total testosterone were
observed in a substudy involving 10 OC+ subjects. The present results suggest
that the testosterone effect is related to the zero-order mechanism of ethanol
oxidation. The observed testosterone and androstenedione effects are suggested to
be the result of an increased androstenedione to testosterone conversion in the
liver caused by the alcohol-mediated elevation in the [NADH]:[NAD(+)] ratio. The
present findings may be relevant in the development of hyperandrogenism and loss
of female sexual characteristics associated with heavy alcohol consumption.
PMID- 10684784
TI - Naltrexone exerts a favourable effect on plasma lipids in abstinent patients with
alcohol dependence.
AB - Epidemiological studies suggest that abstinence periods in some patients with
alcohol dependence may increase their cardiovascular risk via proatherogenic
changes in plasma lipid levels. Because of this, drugs administered in withdrawal
therapy should not exacerbate these effects. The aim of this study was to
estimate the influence of naltrexone, carbamazepine, and lithium carbonate on
plasma lipid levels in 160 alcohol-dependent males during withdrawal therapy.
Plasma concentrations of total cholesterol (TC), HDL cholesterol (HDL-C), LDL
cholesterol (LDL-C), and triglycerides (TGL) were determined every 2 weeks for 20
weeks. Pharmacotherapy (naltrexone 50 mg, carbamazepine 600-800 mg, lithium
carbonate 500-1000 mg once per day or placebo) was given within the framework of
a double-blind study between the fourth and twentieth weeks of the study. The
results of 116 patients who maintained abstinence during the whole 20-week
observation period were analysed. In patients treated with naltrexone significant
decreases in TC (239 +/- 58 vs 216 +/- 52 mg/dl; P < 0.01) and TGL (125 +/- 68 vs
86 +/- 33 mg/dl; P < 0.02) concentrations after 16 weeks of pharmacotherapy were
observed. In patients treated with carbamazepine, significant increases in TC
(224 +/- 39 vs 243 +/- 54 mg/dl, P < 0.04) and HDL (40 +/- 10 vs 44 +/- 8 mg/dl,
P < 0.01) after 16 weeks of pharmacotherapy were observed. After 16 weeks of
pharmacotherapy, patients treated with naltrexone had lower mean TC (P < 0.03)
and LDL-C (P < 0.01) concentrations than patients treated with carbamazepine,
lower mean LDL-C levels than patients treated with lithium carbonate (149 +/- 54
vs 164 +/- 57 mg/dl, P < 0.01), and lower TGL concentrations than patients of the
remaining pharmacotherapy groups. We conclude that naltrexone, by its
hypolipaemic effect, could be useful for withdrawal therapy in alcoholic
patients, because it may decrease the cardiovascular risk in abstinent patients
with alcohol dependence by lipid mechanisms.
PMID- 10684785
TI - Cytochrome P-450 2E1 activity and oxidative stress in alcoholic patients.
AB - As cytochrome P-450 2E1 (CYP2E1) induction was related to oxidative stress in
experimental models, the aim of this study was to investigate the relationship
between CYP2E1 activity and markers of oxidative stress in 40 alcoholic patients
entering a rehabilitation programme. Plasma oxidized proteins, lipid peroxides
(LPO) and antibodies against hydroxyethyl radical (HER) or malondialdehyde (MDA)
adducts were assessed as markers of the production of free radicals, whereas
vitamin E levels were evaluated as a marker of the antioxidant defence. CYP2E1
activity was determined by using the 6-hydroxychlorzoxazone:chlorzoxazone blood
metabolic ratio, 2 h after drug intake. This ratio was increased by 4-fold in
alcoholics, compared to non-alcoholic patients, and was correlated with daily
intake of ethanol, carbohydrate-deficient transferrin, and blood alcohol level at
the time of admission to hospital. Plasma levels of LPO and oxidized proteins
were slightly increased (20%) in alcoholic patients when compared with the
control group, whereas those of vitamin E were found to be slightly decreased (by
18%). Antibodies against HER or MDA adducts showed a very significant increase.
However, when alcoholic patients were divided into two groups according to low or
high CYP2E1 induction, no significant difference was observed in the variation of
these parameters, except for anti-HER adducts antibodies. Therefore, our study
confirms the main involvement of CYP2E1 in HER production. By contrast, CYP2E1
does not appear to be the main factor responsible for the oxidative stress
occurring during human chronic alcoholism. Free radicals from other sources may
therefore contribute significantly to the generation of this oxidative stress.
PMID- 10684786
TI - Self-estimates of blood-alcohol concentration and ability to drive in a
population of soldiers.
PMID- 10684787
TI - Role of transforming growth factor-alpha and the epidermal growth factor receptor
in embryonic rat testis development.
AB - Embryonic testis development requires the morphogenesis of cords and growth of
all cell populations to allow organ formation. It is anticipated that
coordination of the growth and differentiation of various cell types involves
locally produced growth factors. The current study was an investigation of the
hypothesis that transforming growth factor-alpha (TGF-alpha) is involved in
regulating embryonic testis growth. TGF-alpha has previously been shown to
function in the postnatal testis. TGF-alpha and other members of the epidermal
growth factor (EGF) family act through the epidermal growth factor receptor
(EGFR) to stimulate cell proliferation and tissue morphogenesis. To understand
the potential actions of TGF-alpha in the embryonic testis, general cell
proliferation was investigated. Characterization of cell proliferation in the rat
testis throughout embryonic and postnatal development indicated that each cell
type has a distinct pattern of proliferation. Germ cell growth was transiently
suppressed around birth. Interstitial cell growth was high embryonically and
decreased to low levels around birth. A low level of Sertoli cell proliferation
was observed at the onset of testis cord formation. Sertoli cell proliferation in
early embryonic development was low; the levels were high later in embryonic
development and remained high until the onset of puberty. Both TGF-alpha and the
EGFR were shown to be expressed in the embryonic and postnatal rat and mouse
testis. Perturbation of TGF-alpha function using neutralizing antibodies to TGF
alpha on testis organ cultures dramatically inhibited the growth of both
embryonic and neonatal testis. TGF-alpha antibodies had no effect on cord
formation. The TGF-alpha antibody was found to be specific for TGF-alpha in
Western blots when compared to EGF and heregulin. Testis growth was also
inhibited by perturbation of EGFR signaling using an EGFR kinase inhibitor.
Therefore, TGF-alpha appears to influence embryonic testis growth but not
morphogenesis (i.e., cord formation). Treatment of embryonic testis organ
cultures with exogenous TGF-alpha also perturbed development, leading to an
increased proliferation of unorganized cells. Testis from EGFR and TGF-alpha
knockout mice were analyzed for testis morphology. TGF-alpha knockout mice had no
alterations in testis phenotype, while EGFR knockout mice had a transient
decrease in the relative amount of interstitial cells before birth. Observations
suggest that there may be alternate or compensatory factors that allow testis
growth to occur in the apparent absence of TGF-alpha actions in the mutant mice.
In summary, the results obtained suggest that TGF-alpha is an important factor in
the regulation of embryonic testis growth, but other factors will also be
involved in the process.
PMID- 10684788
TI - Expression and action of hepatocyte growth factor in human and bovine normal
ovarian surface epithelium and ovarian cancer.
AB - More than 95% of ovarian cancers originate from the epithelial cells on the
surface of the ovary, which are termed ovarian surface epithelium (OSE). These
OSE cells are modified peritoneal mesothelial cells separated from underlying
ovarian surface stromal tissue by a basal lamina of dense collagenous connective
tissue. Mesenchymal-epithelial cell interactions between stromal cells and OSE
cells are postulated to be important for normal OSE biology and for the onset of
ovarian cancer. Hepatocyte growth factor (HGF) is a mesenchymal-derived growth
factor that mediates mesenchymal-epithelial cell interactions in a number of
different tissues. The current study was an investigation of the expression and
actions of HGF in normal OSE and ovarian cancer. Human epithelial cells from
borderline and stage III ovarian cancer cases were found to express HGF protein
in the epithelial cell component by immunocytochemistry analysis. The stromal
cell component of human ovarian tumors contained little or no HGF immunostaining.
Normal bovine ovaries have a similar physiology and endocrinology to human
ovaries and are used as a model system to investigate normal OSE functions. HGF
protein was detected in the OSE from both normal human and bovine ovaries.
Adjacent ovarian stromal tissue contained light but positive HGF immunostaining.
RNA was collected from normal bovine ovarian stromal cells to examine HGF gene
expression. HGF transcripts were detected in cultured OSE and stromal cells by
Northern blot analysis. Using a quantitative reverse transcription-polymerase
chain reaction procedure, HGF gene expression was found to be high in freshly
isolated OSE but low in freshly isolated stroma. Levels of HGF gene expression
after culture of stroma increased. Observations indicate that normal OSE express
high levels of HGF in vivo and in vitro. Expression of HGF by normal epithelial
cells versus stromal cells was unexpected and suggests that HGF may be important
in an autocrine regulation of OSE. HGF actions on normal OSE cells and ovarian
cancer cells were investigated. HGF was found to stimulate the growth of normal
OSE cells in a manner similar to such growth stimulated by epidermal growth
factor. Two ovarian cancer cell lines, SKOV3 and OCC1, were also stimulated to
grow in response to HGF. This observation suggests that HGF may be involved in
sustaining growth of ovarian tumors. These results are the first to demonstrate
the production and action of HGF in normal OSE cells and ovarian cancer cells.
This appears to be an example of HGF production by an epithelial cell, such that
a mesenchymal-epithelial mixed phenotype is present. The autocrine stimulation of
OSE growth by the local production and action of HGF provides insight into how
the OSE may develop abnormal growth characteristics involved in the onset and
progression of ovarian cancer.
PMID- 10684789
TI - Identification and localization of plasminogen activator inhibitor-1 within the
porcine oviduct.
AB - The porcine oviduct synthesizes de novo and secretes a number of proteins into
culture medium, many of which are unidentified. The objectives of the present
study were to 1) semipurify and identify a M(r) 45 000 secreted protein of the
oviduct, 2) examine its synthesis within the three functional segments
(infundibulum, ampulla, and isthmus), and 3) evaluate its distribution throughout
the oviduct. Oviductal tissue was collected during early pregnancy, divided into
functional segments, and subsequently cultured. Medium was collected, and the
M(r) 45 000 protein was concentrated by gel-filtration chromatography. The
semipurified protein was transferred onto a polyvinylidene fluoride membrane and
subjected to N-terminal amino acid analysis. The 26-amino acid sequence was 96%
identical to that of pig plasminogen activator inhibitor (PAI)-1. Analysis by 1
dimensional SDS-PAGE and fluorography of rabbit anti-human PAI-1
immunoprecipitated product confirmed PAI-1. Subsequent 2-dimensional SDS-PAGE and
fluorographic analyses of media revealed greater PAI-1 synthesis by the isthmus
than by the ampulla or infundibulum. PAI-1 was immunolocalized throughout the
oviduct and was heavily concentrated in the apical region of epithelial cells.
Immunogold electron microscopy localized PAI-1 within putative secretory granules
in the epithelial apical region and also associated with cilia in the isthmus.
Isthmic PAI expression suggests a crucial role in protecting the preimplantation
embryo from proteolytic degradation as well as in regulation of extracellular
matrix turnover and remodeling.
PMID- 10684790
TI - Sperm antigen 6 is the murine homologue of the Chlamydomonas reinhardtii central
apparatus protein encoded by the PF16 locus.
AB - A cDNA encoding sperm antigen 6 (Spag6), the murine homologue of the
Chlamydomonas reinhardtii PF16 protein-a component of the flagella central
apparatus-was isolated from a mouse testis cDNA library. The cDNA sequence
predicted a 55.3-kDa polypeptide containing 8 contiguous armadillo repeats with
65% amino acid sequence identity and 81% similarity to the Chlamydomonas PF1
protein. An antipeptide antibody generated against a C-terminal sequence
recognized a 55-kDa protein in sperm extracts and localized Spag6 to the
principal piece of permeabilized mouse sperm tails. When expressed in COS-1
cells, Spag6 colocalized with microtubules. The Spag6 gene was found to be highly
expressed in testis and was mapped using the T31 radiation hybrid panel to mouse
chromosome 16. Mutations in the Chlamydomonas PF16 gene cause flagellar
paralysis. The presence of a highly conserved mammalian PF16 homologue (Spag6)
raises the possibility that Spag6 plays an important role in sperm flagellar
function.
PMID- 10684791
TI - Selective requirement for Cdc25C protein synthesis during meiotic progression in
porcine oocytes.
AB - Fundamental differences between meiosis and mitosis suggest that the shared
central cell cycle machinery may be regulated differently during the two division
cycles. This paper focuses on unique features of Cdc25C protein function during
meiotic progression. We report on the existence of oocyte-specific CDC25C
transcripts that differ from their somatic counterparts in the 3' untranslated
region. While CDC25C mRNA levels remain constant in fully-grown oocytes,
corresponding protein levels increase progressively during maturation to a
maximum at metaphase II. Elevation of Cdc25C protein levels in G2-oocytes by mRNA
injection failed to increase MPF-kinase levels or to induce premature entry into
M-phase. Likewise, antisense-induced arrest of translation (translational arrest)
had no effect on chromosome condensation, nucleolar disassembly, or nuclear
membrane contraction. By contrast, translational arrest inhibited subsequent
events including membrane disassembly and spindle formation. Neither up- nor down
regulation of Cdc25C synthesis after metaphase I plate formation influenced
progression to metaphase II. However, translational arrest during metaphase
resulted in incomplete chromosome decondensation and abnormal pronuclear membrane
assembly after activation. We conclude that Cdc25 protein, translated from unique
transcripts, is preferentially located in the oocyte nucleus and is essential for
progress through late diakinesis. Subsequently, new synthesis of Cdc25C protein
is required for the orderly transition from meiotic to mitotic cell division.
PMID- 10684792
TI - Pregnancy and exogenous steroid treatments modulate the expression of relaxant
EP(2) and contractile FP receptors in the rat uterus.
AB - Prostaglandins (PGs) interact with specific receptors on plasma membranes to
regulate myometrial activity in many species. The present study examined whether
the expression of relaxant prostaglandin E receptor subtype two (EP(2)) and
contractile prostaglandin F receptor (FP) mRNA in the rat uterus is changed
during various states of pregnancy and regulated by steroid hormones. Expression
of mRNA for EP(2) and FP receptors in the full-thickness uteri was analyzed by
reverse transcription-polymerase chain reaction using specific primers. Abundance
of receptor mRNA was expressed relative to beta-actin mRNA. Results showed that
1) mRNA for EP(2) receptors in the rat uterus was substantially increased during
pregnancy (320%) compared with the nonpregnant state (100%, P < 0.01), and
declined during labor at term (36% vs. 100% in control, P < 0.01); 2) mRNA
expression for FP receptors in rat uterus was increased during pregnancy (333%
vs. 100% in nonpregnant rats, P < 0. 01) and reached maximal levels during labor
(515% vs. 100% in control, P < 0.01); 3) upon RU-486 treatment on Day 19 of
pregnancy, uterine EP(2) receptor mRNA levels were decreased (18% vs. 100% in
control, P < 0.01), and FP mRNA levels were increased (357% vs. 100% in control,
P < 0.01); 4) with ICI 164384 (an antiestrogen) treatment on Day 19 of gestation,
uterine FP receptor mRNA levels were decreased without effects on EP(2)
receptors; 5) in ovariectomized (ovx) rats, progesterone increased EP(2) (163%
vs. 100% in control, P < 0.01) and had no effects on FP receptor mRNA expression
in the rat uterus; 6) estradiol increased FP receptor mRNA levels (358% vs. 100%
in control, P < 0.01) and had no effects on EP(2) mRNA in the ovx rat uterus.
Therefore, we conclude that steroid hormones modulate the mRNA for relaxant EP(2)
and contractile FP receptors for PGs in the uterus and thus regulate uterine
activity during pregnancy and labor.
PMID- 10684793
TI - Platelet-activating factor induces an imbalance between matrix metalloproteinase
1 and tissue inhibitor of metalloproteinases-1 expression in human uterine
cervical fibroblasts.
AB - Platelet-activating factor (PAF) is involved in such reproductive processes as
parturition. We investigated the effect of PAF on the expression of matrix
metalloproteinase-1 (MMP-1) and that of tissue inhibitor of metalloproteinases-1
(TIMP-1) in human uterine cervical fibroblasts. Uterine cervical tissue was
obtained from patients who underwent cesarean section at term. Collagenase
dispersed fibroblasts were cultured and used in the experiments. PAF receptor was
identified in the uterine cervical fibroblasts by use of reverse transcription
polymerase chain reaction and Southern blot analysis. Northern blot analysis
showed that PAF increased the expression of MMP-1 mRNA in a time-dependent
manner, whereas expression of TIMP-1 mRNA was not affected by PAF. Concentration
of MMP-1 protein in the PAF-treated culture media significantly exceeded that in
control cultures. The PAF-induced production of MMP-1 protein was abolished by
treatment with WEB 2170, a specific PAF receptor antagonist. Results suggest that
PAF may accelerate collagenolysis in the human uterine cervix by inducing an
imbalance in the activity between MMP-1 and TIMP-1, thus contributing to the
cervical ripening during parturition.
PMID- 10684794
TI - Immunocytochemical localization of lipocalin-type prostaglandin D synthase in the
bull testis and epididymis and on ejaculated sperm.
AB - Previously, we identified a 26-kDa fertility-associated protein in bull seminal
plasma as lipocalin-type prostaglandin D synthase. The objective of the present
study was to immunohistochemically localize this enzyme to the various cell types
within the bull testis and seven subsegments of the epididymis, and on ejaculated
sperm in order to gain further insight into its potential function in male
reproduction. In the testis, immunoperoxidase staining was localized within the
elongating spermatids and Sertoli cells of the seminiferous tubules, varying with
the stage of the spermatogenic cycle. The highest level of staining occurred
during stages III-VII. The cuboidal epithelial cells of the rete testis and
efferent ducts were also immunoreactive. Expression of lipocalin-type
prostaglandin D synthase was not uniform in the seven epididymal subsegments,
suggesting a possible role in sperm maturation. In all epididymal regions,
expression was limited to the epithelial principal cells; no immunoreactivity was
apparent in other cell types. Lipocalin-type prostaglandin D synthase was
strikingly localized in the caput epididymidis, while moderate to weak staining
was observed in the remainder of the epididymis. Droplets of reaction product
observed within the lumen increased progressively from the caput to cauda. Using
fluorescence microscopy, we also localized lipocalin-type prostaglandin D
synthase to the apical ridge of the acrosome on ejaculated sperm.
PMID- 10684795
TI - Sperm aster formation and pronuclear decondensation during rabbit fertilization
and development of a functional assay for human sperm.
AB - Microtubule organization and chromatin configurations in rabbit eggs after in
vivo rabbit fertilization and after intracytoplasmic injection with human sperm
were characterized. In unfertilized eggs, an anastral barrel-shaped meiotic
spindle, oriented radially to the cortex, was observed. After rabbit sperm
incorporation, microtubules were organized into a radial aster from the sperm
head, and cytoplasmic microtubules were organized around the male and female
pronuclei. The microtubules extending from the decondensed sperm head
participated in pronuclear migration, and organization around the female
pronucleus may also be important for pronuclear centration. Support for these
observations was found in parthenogenetically activated eggs, in which
microtubule arrays were organized around the single female pronucleus that formed
after artificial activation. These observations support a biparental centrosomal
contribution during rabbit fertilization as opposed to a strictly paternal
inheritance pattern suggested from previous studies. In rabbit eggs that received
injected human donor sperm, an astral array of microtubules radiated from the
sperm neck and enlarged as the sperm head underwent pronuclear decondensation.
gamma-Tubulin was observed in the center of the sperm aster. We conclude that the
rabbit egg exhibits a blended centrosomal contribution necessary for completion
of fertilization and that the rabbit egg may be a novel animal model for
assessing centrosomal function in human sperm and spermatogenic cells following
intracytoplasmic injection.
PMID- 10684796
TI - Birth of piglets after transfer of embryos cryopreserved by cytoskeletal
stabilization and vitrification.
AB - Pig embryos suffer severe sensitivity to hypothermic conditions, which limits
their ability to withstand conventional cryopreservation. Research has focused on
high lipid content of pig embryos and its role in hypothermic sensitivity, while
little research has been conducted on structural damage. Documenting cytoskeletal
disruption provides information on embryonic sensitivity and cellular response to
cryopreservation. The objectives of this study were to document microfilament
(MF) alterations during swine embryo vitrification, to utilize an MF inhibitor
during cryopreservation to stabilize MF, and to determine the developmental
competence of cytoskeletal-stabilized and vitrified pig embryos. Vitrified
morulae/early blastocysts displayed MF disruptions and lacked developmental
competence after cryopreservation; hatched blastocysts displayed variable MF
disruption and developmental competence. Cytochalasin-b did not improve
morula/early blastocyst viability after vitrification; however, it significantly
(P < 0.05) improved survival and development of expanded and hatched blastocysts.
After embryo transfer, we achieved pregnancy rates of almost 60%, and litter
sizes improved from 5 to 7.25 piglets per litter. This study shows that the pig
embryo cytoskeleton can be affected by vitrification and that MF depolymerization
prior to vitrification improves blastocyst developmental competence after
cryopreservation. After transfer, vitrified embryos can produce live, healthy
piglets that grow normally and when mature are of excellent fecundity.
PMID- 10684797
TI - A metabolite of methoxychlor, 2,2-bis(p-hydroxyphenyl)-1,1, 1-trichloroethane,
reduces testosterone biosynthesis in rat leydig cells through suppression of
steady-state messenger ribonucleic acid levels of the cholesterol side-chain
cleavage enzyme.
AB - Postnatal development of Leydig cells involves transformation through three
stages: progenitor, immature, and adult Leydig cells. The process of
differentiation is accompanied by a progressive increase in the capacity of
Leydig cells to produce testosterone (T). T promotes the male phenotype in the
prepubertal period and maintains sexual function in adulthood; therefore,
disruption of T biosynthesis in Leydig cells can adversely affect male fertility.
The present study was designed to evaluate the ability of a xenoestrogen,
methoxychlor (the methoxylated isomer of DDT [1,1, 1-trichloro-2,2-bis(p
chlorophenyl)ethane]), to alter Leydig cell steroidogenic function. Purified
progenitor, immature, and adult Leydig cells were obtained from, respectively, 21
, 35-, and 90-day-old Sprague-Dawley rats treated with graded concentrations of
the biologically active metabolite of methoxychlor, 2, 2-bis(p-hydroxyphenyl)
1,1,1-trichloroethane (HPTE), and assessed for T production. HPTE caused a dose
dependent inhibition of basal and LH-stimulated T production by Leydig cells.
Compared to the control value, reduced T production by progenitor and immature
Leydig cells was apparent after 10 h of HPTE treatment in culture; the equivalent
time for adult Leydig cells was 18 h. The reversibility of HPTE-induced
inhibition was evaluated by incubating Leydig cells for 3, 6, 10, 14, or 18 h and
measuring T production after allowing time for recovery. After treatment with
HPTE for 3 h, T production by immature and adult Leydig cells for the 18-h
posttreatment period was similar to the control value, but that of progenitor
Leydig cells was significantly lower. The onset of HPTE action and the
reversibility of its effect showed that Leydig cells are more sensitive to this
compound during pubertal differentiation than in adulthood. T production was
comparable when control and HPTE-treated immature Leydig cells were incubated
with pregnenolone, progesterone, and androstenedione, but HPTE-treated Leydig
cells produced significantly reduced amounts of T when incubations were conducted
with 22R-hydroxycholesterol (P < 0.01). This finding suggested that HPTE-induced
inhibition of T production is related to a decrease in the activity of cytochrome
P450 cholesterol side-chain cleavage enzyme (P450(scc)) and cholesterol
utilization. The reduced steady-state mRNA level for P450(scc) in HPTE-treated
Leydig cells was demonstrated by reverse transcription-polymerase chain reaction
and densitometry. In conclusion, this study showed that HPTE causes a direct
inhibition of T biosynthesis by Leydig cells at all stages of development. This
effect suggests that reduced T production could be a contributory factor in male
infertility associated with methoxychlor and, possibly, other DDT-related
compounds.
PMID- 10684798
TI - Assay and importance of adhesive interaction between hamster (Mesocricetus
auratus) oocyte-cumulus complexes and the oviductal epithelium.
AB - Adhesion between the oocyte-cumulus complex and infundibulum plays an important,
but poorly understood, role in oocyte pick-up. The purposes of this study were to
determine which components of the oocyte-cumulus complex and oviductal epithelium
function in adhesion, to measure adhesion under physiological conditions, and to
examine the effect of modulation of adhesion on oocyte-cumulus complex pick-up
rate. Oocyte-cumulus complexes containing an expanded matrix were readily
transported into the oviduct, while unexpanded complexes lacking an extracellular
matrix were not picked up, indicating that the matrix is necessary for pick-up.
Transmission electron microscopy revealed that during pick-up, adhesion occurred
specifically between the ciliary crowns of the oviduct and the granules and
filaments of the cumulus matrix. An assay was developed using vacuum from a low
flow peristaltic precision pump, modified for bi-directional flow, to measure the
strength of adhesion between the oocyte-cumulus complex and the oviductal
epithelium, and adhesion was measured during physiological conditions. The lectin
wheat germ agglutinin and the polycation poly-L-lysine were then used to modulate
adhesion, and the effects of increasing or decreasing adhesion on oocyte pick-up
rate and ciliary beat frequency were examined. The data show that 1) the matrix
of the oocyte-cumulus complex and the ciliary crowns of the oviduct function in
adhesion during pick-up and that adhesion is necessary for pick-up, 2) adhesion
can be assayed quantitatively and is very uniform among control infundibula, and
3) decreasing or increasing adhesion decreases oocyte pick-up rate and in some
cases prevents pick-up without affecting ciliary beat frequency.
PMID- 10684799
TI - Caspase-3 and -6 expression and enzyme activity in hen granulosa cells.
AB - We have cloned and sequenced cDNAs corresponding to the complete coding regions
of the chicken homologues to mammalian caspase-3 and caspase-6. Both caspases are
included among members of the cysteine protease (caspase) family that are most
closely identified with mediating apoptosis. The deduced amino acid sequences for
chicken caspase-3 and -6 show 65% and 68% identity with the respective human
sequences, with complete conservation found within the QACRG active peptide
region. Both caspase-3 and -6 are widely expressed within various tissues from
the hen. Within the ovary, levels of caspase-3 and caspase-6 mRNA and protein do
not change significantly in theca tissue during follicle development. On the
other hand, procaspase-3 and -6 protein levels are elevated by 2- to 5-fold in
preovulatory, compared to prehierarchal (6- to 8-mm diameter), follicle granulosa
cells. Nevertheless, the function of this family of cell death-inducing proteins
requires activation of the proenzyme caspase, which occurs after cleavage at
predictable sites within the N-terminal domain. Accordingly, it was determined
that okadaic acid, a pharmacologic inducer of apoptotic cell death in cultured
apoptosis-resistant, preovulatory follicle granulosa cells, induced both caspase
3- and caspase-6-like activity within 8-16 h of treatment. By comparison,
spontaneous apoptotic cell death that occurs in apoptosis-sensitive,
prehierarchal follicle granulosa cells after short-term suspension culture is
accompanied by a more rapid increase (within 2 h) in both caspase-3- and -6-like
activity. Treatment with 8-bromo-cAMP, which has previously been shown to
attenuate, or at least slow, the onset of apoptosis in prehierarchal follicle
granulosa cells, mitigates this suspension culture-induced increase in caspase
activity. While the present results provide further support for the relationship
between caspase activation and apoptotic cell death in hen granulosa cells, the
molecular ordering of enzymatic events and the caspase-specific substrates remain
to be elucidated.
PMID- 10684800
TI - Gonadotropin induction of ovulation and corpus luteum formation in young estrogen
receptor-alpha knockout mice.
AB - Estrogen receptor-alpha (ERalpha) knockout (ERalphaKO) female mice are infertile.
Initially, they exhibit normal follicular development, but by 4-5 wk of age, they
begin to develop hemorrhagic ovarian cysts. Follicles in adult ERalphaKO female
mice progress to the graafian stage, but there are no corpora lutea (CL). To test
whether ERalpha is required for ovarian folliculogenesis, ovulation, and CL
formation, eCG and hCG were used to ovulate 3- to 5-wk-old ERalphaKO and wild
type (WT) sibling mice. Gonadotropin administration resulted in ovulation in both
ERalphaKO and WT mice. Gonadotropin-treated ERalphaKO females that ovulated
produced 7.09 +/- 0.77 oocytes per mouse, whereas gonadotropin-treated WT female
mice had 16.17 +/- 0.84 oocytes. Surprisingly, ruptured ERalphaKO ovarian
follicles developed into CL that had normal morphology. Gonadotropin-treated
ERalphaKO mice had 3-fold higher concentrations of serum progesterone than did
control ERalphaKO mice that had been administered saline rather than
gonadotropins. Thus, the CL in gonadotropin-treated ERalphaKO mice appeared to be
steroidogenically functional. On the basis of these findings, ovarian
folliculogenesis, ovulation, and CL formation can occur in the absence of
ERalpha, although to a lesser extent than in WT mice.
PMID- 10684801
TI - Expression of human proacrosin in Escherichia coli and binding to zona pellucida.
AB - Proacrosin is a multifunctional protein present in the sperm acrosome. This study
characterizes the expression of human proacrosin in bacteria and assesses zona
pellucida binding activity. The cDNA encoding human proacrosin was subcloned in
pGEX-3X and pET-22b vectors. In the pGEX system, expression of the full-length
fusion protein was not detected. In the pET system, an expression product with an
apparent molecular size similar to that expected for the proenzyme (Rec-40, 42-44
kDa) was recognized by a monoclonal antibody to human acrosin, AcrC5F10. A 32-34
kDa protein (Rec-30), not recognized by AcrC5F10 on Western blots, was the major
expression product. Proteins of 21 (Rec-20) and 18 (Rec-10) kDa were recovered as
insoluble expression products as were Rec-40 and Rec-30, and truncated products
from the C terminus were detected in the soluble fraction. Rec-40 and Rec-30
coexisted at any culture time tested. Immune serum raised against Rec-30 (AntiRec
30) stained the acrosomal region of permeabilized human spermatozoa and
recognized the recombinant proteins and proacrosin from human sperm extracts.
Amino acid sequence analysis indicated that Rec-30, Rec-20, and Rec-10 are N
terminal fragments of proacrosin. The recombinant proteins Rec-40, -30, -20, and
10 were found to interact with homologous (125)I-zona pellucida glycoproteins.
PMID- 10684802
TI - Epigenetic modifications necessary for normal development are established during
oocyte growth in mice.
AB - The ability of maternal chromatin to support full-term development is attained
during oocyte growth. The aim of this study was to identify when during the
growth phase the maternal chromatin developed the capacity to support term
development. Mature metaphase II-arrested oocytes that contained chromatin from
oocytes at different stages of oocyte growth were constructed by
micromanipulation. The oocytes were fertilized in vitro, developed to the
blastocyst stage in vitro, and transferred to recipients to assay developmental
potential. The results demonstrate, firstly, that the origin of the maternal
chromatin has no effect on the rate of oocyte maturation, fertilization, or
development to the blastocyst in vitro. Secondly we demonstrate that maternal
chromatin is first competent to support development to term during the latter
half of oocyte growth when oocytes are 60-69 microm in diameter in juvenile mice
or 50-59 microm in diameter in adult mice. These data show that epigenetic
modifications necessary for postimplantation development occur during a specific
phase of oocyte growth.
PMID- 10684803
TI - Interferon-tau and progesterone regulate ubiquitin cross-reactive protein
expression in the ovine uterus.
AB - Ubiquitin cross-reactive protein (UCRP) is a functional ubiquitin homolog
synthesized by the ruminant endometrium in response to conceptus-derived
interferon-tau (IFNtau). Progesterone is required for IFNtau to exert
antiluteolytic actions on the endometrium. Therefore, this study was designed to
determine whether progesterone is requisite for IFNtau induction of UCRP
expression within the ovine uterus. Cyclic ewes were ovariectomized and fitted
with intrauterine (i.u.) catheters on Day 5 and treated daily with steroids
(i.m.) and protein (i.u.) as follows: 1) progesterone (P, Days 5-24) and control
serum proteins (CX, Days 11-24); 2) P and ZK 137.316 (ZK; progesterone receptor
antagonist, Days 11-24) and CX proteins; 3) P and recombinant ovine IFNtau
(roIFNtau, Days 11-24); or 4) P and ZK and roIFNtau. All ewes were
hysterectomized on Day 25. In P-treated ewes, roIFNtau increased endometrial UCRP
mRNA and protein levels. However, administration of ZK to ewes ablated roIFNtau
induction of UCRP. Recombinant ovine IFNtau induced expression of UCRP mRNA in
progestinized endometrial luminal (LE) and glandular (GE) epithelium as well as
in both stratum compactum and spongiosum layers of the stroma (ST). Progesterone
receptor protein was located in endometrial ST, but not in LE and GE from these
ewes. Results support the hypothesis that progesterone is required for IFNtau
induction of type I IFN-responsive genes, such as UCRP, in the ruminant uterus.
PMID- 10684804
TI - Assessing chromosomal abnormalities in two-cell bovine in vitro-fertilized
embryos by using fluorescent in situ hybridization with three different cloned
probes.
AB - The aim of this study was to assess the efficiency of fluorescent in situ
hybridization (FISH) for detecting chromosomal abnormalities in in vitro
fertilized (IVF) bovine embryos as early as the 2-cell stage. Three different
cloned probes were used, two derived from a unique sequence specific to the
subtelomeric (D1S48) or subcentromeric regions (19C10) of chromosome 1 and the
third (H1A clone) derived from a repetitive sequence that hybridizes to the
subcentromeric regions of three other chromosomes (14, 20, 25). Our results show
that the incidence of chromosomal abnormalities in 2-cell bovine IVF embryos
varied from 28% to 44% according to the probes used for the analysis. Whereas the
efficiency of FISH was high with somatic nuclei, it appeared to be highly
variable with the 2-cell embryos. FISH efficiency depended firstly on the probe
sequence (repetitive or unique sequence), secondly on the chromosomal target
region (centromeric or telomeric regions), and thirdly on the embryo cell cycle
phase. With a unique sequence probe (19C10) specific to the subcentromeric
regions, FISH efficiency was better on nuclei in the S-phase cycle than on those
in the G-phase. In S-phase 2-cell embryos, the overall incidence of chromosomal
abnormalities was more accurately assessed. It reached 13% and was represented by
1n/2n mixoploidies.
PMID- 10684805
TI - Follistatin suppresses steroid-enhanced follicle-stimulating hormone release in
vitro in rats.
AB - Previous in vitro and in vivo studies from our laboratory showed that
progesterone (P(4)), corticosterone (B), and testosterone (T) increase
intracellular content and release of FSH in the anterior pituitary. Activin (Act)
and inhibin (Inh) are structurally related proteins with antagonistic actions, as
Act stimulates and Inh inhibits FSH secretion from the anterior pituitary.
Together with follistatin (FS), a protein that bioneutralizes Act, they form an
autocrine-paracrine loop in the anterior pituitary that tightly regulates FSH
secretion. The objective of the present study was to test the hypothesis that
P(4), B, and T modulate this autocrine-paracrine loop to favor increased FSH
secretion. If Act were to mediate steroid-induced FSH release, FS would be
expected to block these effects. To test this interaction, cell cultures were
prepared from anterior pituitaries of male and female rats, and treated with Act,
B, P(4), or T in the absence or presence of FS. Act, B, P(4), and T increased FSH
release; FS suppressed both basal and Act- and steroid-stimulated FSH release to
approximately 50% below basal levels. Cell cultures from anterior pituitary of
female rats were used to compare the interaction of incremental concentrations of
FS on dose-related Act- and P(4)-stimulated FSH release. With increasing
concentrations of Act, the FS-induced suppression of FSH release was attenuated
and eventually abolished; in contrast, maximally stimulatory concentrations of
P(4) did not fully overcome the FS-induced suppression of FSH release. The
effects of P(4), B, and Act in the presence and absence of estradiol on steady
state mRNA levels of FSHbeta, Actbeta(B), and FS were determined in primary
pituitary cell cultures from metestrous female rats by reverse transcription
polymerase chain reaction. Whereas Act, P(4), B increased FSHbeta mRNA levels,
only Act raised the level of FS mRNA, and neither steroid increased Actbeta(B)
mRNA. The results support the hypothesis that endogenous Act is a common mediator
of the action of P(4), B, and T in the rat primary anterior pituitary cell
culture. We conclude that the stimulation of FSH release and intracellular
content in the gonadotroph by P(4), B, and T is mediated, in part, by Act and
involves modulation of a tightly regulated Act/FS autocrine-paracrine loop.
PMID- 10684806
TI - Vacuolar system-associated protein-60: a protein characterized from bovine
granulosa and luteal cells that is associated with intracellular vesicles and
related to human 80K-H and murine beta-glucosidase II.
AB - It has been suggested that proteins of molecular size 56-58 kDa play an important
role in bovine ovarian follicular development and oocyte maturation. A polyclonal
antibody was raised against a 56- to 58-kDa protein band purified from bovine
granulosa cells and was used to screen granulosa or luteal cell cDNA expression
libraries. This work resulted in the identification of a cDNA encoding for a
protein of 60.1 kDa with a signal peptide of 13 residues. The bovine 60.1-kDa
protein shared an overall 86.7% and 81.8% identity with, respectively, the human
80K-H protein and the mouse putative beta subunit of glucosidase II (beta-GII),
and was named vacuolar system-associated protein-60 (VASAP-60). Marked
differences in sequence identity were noted in a putative molecular adapter
domain containing a tandem D and E amino acid stretch flanked by proline-rich
sequences presenting the minimal PXXP SH3 motif. VASAP-60 was shown to be
unglycosylated using endoglycosidase H treatment and was found mainly in a
cellular membrane fraction of bovine corpus luteum. VASAP-60 was localized in a
rat hepatic Golgi/endosome fraction and in wheat germ agglutinin (WGA) affinity
chromatographic eluates, thereby suggesting the presence of interactions with
membrane glycoproteins. A polyclonal antibody was raised against the putative
adapter domain of the recombinant VASAP-60; this was shown to recognize a major
88-kDa and two minor 58-kDa and 50-kDa proteins, suggesting that the major 88-kDa
protein band represents the complete VASAP-60 protein whereas the 58-kDa and the
50-kDa bands represent its proteolytic fragments. Northern blot analysis
demonstrated the presence of a single 2.3-kilobase transcript in all the bovine
tissues analyzed with variation in the steady state level between tissues.
Immunohistochemical observations showed that VASAP-60 was widely distributed in
bovine tissues and was localized in pericytoplasmic and perinuclear membranes. In
epithelial cells, the staining presented a basolateral or apical polarity
associated with intracellular vacuoles. In conclusion, we have characterized a
novel acidic membrane protein, associated with organelles of the vacuolar system,
that is widely and histospecifically expressed in bovine tissues. VASAP-60
represents either the bovine ortholog or a new family member of the previously
characterized human 80K-H and murine beta-GII proteins. Our results suggest that
VASAP-60 presents characteristics of a molecular adaptor protein with functions
in membrane-trafficking events.
PMID- 10684807
TI - A putative stimulatory role of progesterone acting via progesterone receptors in
the steroidogenic cells of the human corpus luteum.
AB - To further explore the proposed auto-regulatory role of progesterone action in
the human corpus luteum (CL), the expression and functional roles of progesterone
receptor (PR) isoforms A and B during the luteal phase (LP) of the menstrual
cycle were investigated. A total of 27 otherwise healthy patients previously
scheduled for surgery were recruited after informed consent. An LH rise was
detected, and CL were grouped according to age (Days 2-5 post-LH-rise, early LP;
Days 6-10, mid LP; Days 11-14, late LP). Using a semiquantitative reverse
transcription-polymerase chain reaction assay, the PR-B mRNA levels, which were
100- to 1000-fold lower than PR-A/B mRNA, were 46% lower (P < 0.05, n = 24) in
mid LP, compared to early and late LP. CL tissue levels of progesterone and PR
A/B protein levels were inversely correlated to increasing CL age; i.e.,
significantly reduced levels were observed in the late LP (r(2) = 0.34, P < 0.01,
n = 23). Expression of PR-A/B mRNA as well as PR-A/B protein were detected by in
situ hybridization and immunohistochemistry, respectively. Both methods revealed
a clear and distinct localization to cells in the steroidogenic layer of the CL.
Freshly obtained mid-luteal CL cells were cultured in vitro, and media were
analyzed for progesterone concentrations after treatment by incremental doses of
hCG and the stable PR antagonist mifepristone, alone or in combination.
Mifepristone did not per se alter progesterone synthesis, but when it was added
in conjunction with hCG, a dose-related inhibitory response was seen, with a
maximal 47% reduction in progesterone output at a 10 microM addition (P < 0.05, n
= 3). Collectively, these data implicate a stimulatory role of progesterone
receptor-mediated action in the steroidogenic cells of the human CL, which may
serve as an important pathway for maintaining functional homeostasis during early
pregnancy.
PMID- 10684808
TI - Developmental expression of thyroid hormone receptors in the rat testis.
AB - Sertoli cell proliferation in the rat is completed by Days 15-20 postnatally.
Thyroid hormones appear to regulate the duration of Sertoli cell proliferation,
affecting adult Sertoli cell number and hence the capacity of the testis to
produce sperm. In the present study, a combination of immunohistochemistry,
immunoblot analysis, and reverse transcription-polymerase chain reaction was used
to demonstrate the expression pattern of thyroid hormone receptors (TR) in the
juvenile and adult rat testis. The results indicated that TRalpha1 was expressed
in proliferating Sertoli cell nuclei, its expression decreasing coincident with
the cessation of proliferation. TRalpha2, TRalpha3, and TRbeta1 mRNAs were
expressed at low levels during development; however, the corresponding protein
was not detected by immunoblot analysis. In addition, TRalpha1 was found to be
expressed in germ cells from intermediate spermatogonia to mid-cycle pachytene
spermatocytes. Immunohistochemistry also demonstrated TR expression in a subset
of interstitial cells. The demonstration of TR expression in germ cells
undergoing spermatogenic differentiation suggests a possible role for thyroid
hormones in the adult testis.
PMID- 10684809
TI - Expression of steroidogenic factor 1 in the testis requires an E box and CCAAT
box in its promoter proximal region.
AB - Steroidogenic factor 1 (SF-1), also known as adrenal 4-binding protein, is a
member of the nuclear hormone receptor family that regulates transcription of
genes encoding hormones and steroidogenic enzymes important to the function of
the hypothalamic-pituitary-gonadal axis. The mammalian Ftz-F1 gene encodes SF-1
and is required for development of adrenal glands and gonads. To better
understand the mechanisms regulating this gene in the gonads, we have examined
its expression in the testis and characterized the promoter region for SF-1 in
two testicular cell types. SF-1 promoter activity was examined in primary
cultures of Sertoli cells and cell lines representative of Sertoli and Leydig
cells. Deletion mutagenesis of the promoter identified several regions: both 5'
and 3' to the transcriptional start sites that are important for transcriptional
activity. Two elements, an E box and a CCAAT box, were found to be important for
SF-1 transcription in the testis. An oligodeoxynucleotide containing both of
these elements bound three specific protein complexes. The binding of one complex
required only sequences within the E box and cross-reacted with antibodies
against the basic helix-loop-helix ZIP proteins USF1 and USF2. A second specific
complex required sequences within both the E box and CCAAT box for efficient
binding, while a third complex predominantly interacted with sequences within the
CCAAT motif. The presence of multiple protein complexes binding these sites
suggests that regulation through these elements may involve interactions with
different factors that depend on the state of the cell and its environment.
PMID- 10684810
TI - Changes in the testis interstitium of Sprague Dawley rats from birth to sexual
maturity.
AB - Changes in the rat testis interstitium from birth to adulthood were studied using
Sprague Dawley rats of 1, 7, 14, 21, 28, 40, 60, and 90 days of age. Our
objectives were 1) to understand the fate of the fetal Leydig cells (FLC) in the
postnatal rat testis, 2) to determine the volume changes in testicular
interstitial components and testicular steroidogenic capacity in vitro with age,
3) to differentially quantify FLC, adult Leydig cells (ALC), and different
connective tissue cell types by number and average volume, and 4) to investigate
the relationship between mesenchymal and ALC numbers during testicular
development. FLC were present in rat testes from birth to 90 days, and they were
the only steroidogenic cells in the testis interstitium at Days 1 and 7. Except
for FLC, all other interstitial cell numbers and volumes increased from birth to
90 days. The average volume of an FLC and the absolute volume of FLC per testis
were similar at all ages except at Day 21, when lower values were observed for
both parameters. FLC number per testis remained constant from birth through 90
days. The observations suggested that the significance of FLC in the neonatal
prepubertal rat testis is to produce testosterone to activate the hypothalamo
hypophyseal-testicular axis for the continued development of the male
reproductive system. ALC were the abundant Leydig cell type by number and
absolute volume per testis from Day 14 onwards. The absolute numbers of ALC and
mesenchymal cells per testis increased linearly from birth to 90 days, with a
slope ratio of 2:1, respectively, indicating that the rate of production of
Leydig cells is 2-fold greater than that of mesenchymal cells in the postnatal
rat testis through 90 days. In addition, this study showed that the mesenchymal
cells are an active cell population during testis development and that their
numbers do not decrease but increase with Leydig cell differentiation and
testicular growth up to sexual maturity (90 days).
PMID- 10684811
TI - Human endometrial endothelial cells: isolation, characterization, and
inflammatory-mediated expression of tissue factor and type 1 plasminogen
activator inhibitor.
AB - Binding of Ulex europaeus lectin to microvessels was used to isolate endothelial
cells from cycling human endometrium. Cultured human endometrial endothelial
cells (HEECs) exhibited endothelial cell-specific characteristics such as tube
formation on a basement membrane matrix and sequestration of acetylated low
density lipoprotein. Markers for potentially contaminating epithelial, stromal,
smooth muscle, and bone marrow-derived cells were not detected in the HEEC
cultures. Basal and proinflammatory-stimulated immunostaining profiles for
endothelial cell-specific adhesion markers, as exemplified by Von Willebrand's
factor and E-selectin, were similar for cultured HEECs and human umbilical venous
cord endothelial cells (HUVECs). However, HUVECs expressed several extracellular
matrix proteins that were absent from cultured HEECs. In the latter, the protein
kinase C agonist phorbol myristate acetate transiently enhanced tissue factor
(TF) mRNA levels and elicited a more prolonged elevation in TF protein levels,
but did not affect plasminogen activator inhibitor-1 (PAI-1) mRNA and protein
levels. Inappropriate expression of TF, which initiates hemostasis by generating
thrombin, and of PAI-1, which regulates hemostasis by acting as the primary
inhibitor of fibrinolysis, can each lead to thrombosis. The differential
regulation of TF and PAI-1 expression revealed in the current study emphasizes
the importance of using HEECs to evaluate mechanisms regulating the
hemostatic/thrombotic balance in human endometrium.
PMID- 10684812
TI - Gestational profile of leptin messenger ribonucleic acid (mRNA) content in the
placenta and adipose tissue in the rat, and regulation of the mRNA levels of the
leptin receptor subtypes in the hypothalamus during pregnancy and lactation.
AB - Serum leptin levels were significantly increased during rat gestation. Our data
showed that leptin mRNA levels in both the adipose tissue and placenta were
higher as pregnancy progressed, suggesting a role for both tissues in the
hyperproduction of leptin. This paradoxical increase in leptin concentration
during gestation suggests that a physiological state of leptin resistance may
exist at the hypothalamic level that may explain the hyperphagia observed in
pregnant rats. In order to study this issue further, levels of the mRNA encoding
the different leptin receptor isoforms were determined in the hypothalamus of
pregnant and nonpregnant rats. We found a specific reduction of the mRNA levels
encoding the leptin receptor isoform Ob-Rb in the hypothalamus of pregnant rats
compared to nonpregnant animals, suggesting that during pregnancy the
hypothalamus shows a physiological resistance to the high levels of leptin due,
at least in part, to a decrease in the expression of the long, biologically
active form of the leptin receptor (Ob-Rb). During lactation, serum leptin levels
returned to values observed in nonpregnant rats. In the hypothalami of these
animals, Ob-Rb mRNA content was similar to that observed in nonpregnant rats, but
we found an increased expression of some of the short forms of the leptin
receptor (Ob-Re and Ob-Rf). This could contribute to induction of the hyperphagia
present during lactation. These data provide new insights into the adaptive
mechanisms that take place during pregnancy and lactation in order to meet
increased metabolic requirements.
PMID- 10684813
TI - Characterization of ovarian function in granulocyte-macrophage colony-stimulating
factor-deficient mice.
AB - During the estrous cycle and early pregnancy, lymphohemopoietic cytokines and
chemokines contribute to the regulation of ovarian function by orchestrating the
recruitment and activation of leukocytes associated with the ovulatory follicle
and corpus luteum. The purpose of this study was to investigate the physiological
role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the ovary,
utilizing mice genetically deficient in GM-CSF. Our results show that the mean
duration of the estrous cycle in GM-CSF-deficient (GM-/-) mice was extended by
1.5 days (mean +/- SE, 4.9 +/- 0.3 vs. 6.5 +/- 0.5 days for GM+/+ and GM-/- mice,
respectively). Similar ovulation rates were observed in immature superovulated
mice (31.8 +/- 7.7 vs. 28.9 +/- 6.4 oocytes per mouse) and adult naturally
cycling mice (10.4 +/- 0.8 vs. 10.3 +/- 0.8 oocytes per mouse). Furthermore,
comparable numbers of oocytes were released from GM+/+ and GM-/- ovaries in an in
vitro perfusion model. However, ovaries in pregnant GM-/- mice were found to
comprise fewer cells and synthesize less progesterone (141.6 +/- 10.3 vs. 116.5
+/- 6 nM plasma), although the duration of pseudopregnancy was unaltered by GM
CSF deficiency (11.0 +/- 0.2 vs. 11.0 +/- 0.5 days). Immunohistochemical staining
of leukocytes in the ovary during the periovulatory period indicated that the
size and composition of ovarian leukocyte populations were unaltered in the
absence of GM-CSF. However, an effect of GM-CSF deficiency on the activation
phenotype of ovarian leukocytes was indicated by a 57% increase in mean secretion
of nitric oxide in in vitro-perfused GM-/- ovaries, and diminished major
histocompability complex (MHC) class II (Ia) expression in ovarian macrophages
and/or dendritic cells (30.5 +/- 7. 2% vs. 9.1 +/- 1.8% positive stain in GM+/+
and GM-/- ovaries, respectively). Furthermore, ovarian macrophages and
neutrophils were diminished in number after parturition, with significantly
decreased CD11b+ (Mac-1) staining in the stromal region of postpartum GM-/-
ovaries (6.7 +/- 0.6 vs. 3.6 +/- 0.7% positive stain). In summary, GM-CSF does
not appear to be essential for ovarian function but may play a role in fine
tuning the activation status and adhesive properties of ovarian myeloid
leukocytes. Aberrant activation of these cells appears to compromise the
luteinization process and the steroidogenic capacity of the corpus luteum during
early pregnancy in GM-CSF-deficient mice.
PMID- 10684814
TI - Ontogeny of angiotensin II type 1 receptor and cytochrome P450(c11) in the sheep
adrenal gland.
AB - In the present study we investigated the ontogeny of the expression of the type 1
angiotensin receptor (AT(1)R mRNA) and the zonal localization of AT(1)R
immunoreactivity (AT(1)R-ir) and cytochrome P450(c11) (CYP11B-ir) in the sheep
adrenal gland. In the adult sheep and in the fetus from as early as 90 days
gestation, intense AT(1)R-ir was observed predominantly in the zona glomerulosa
and to a lesser extent in the zona fasciculata, and it was not detectable in the
adrenal medulla. AT(1)R mRNA decreased 4-fold between 105 days and 120 days,
whereas AT(1)R mRNA levels remained relatively constant between 120 days and the
newborn period. In contrast, both in the adult sheep and in the fetal sheep from
as early as 90 days gestation, intense CYP11B-ir was consistently detected
throughout the adrenal cortex and in steroidogenic cells that surround the
central adrenal vein. In conclusion, we speculate that the presence of AT(1)R in
the zona fasciculata, and the higher levels of expression of AT(1)R at around 100
days gestation, may suggest that suppression of CYP17 is mediated via AT(1)R at
this time. The abundant expression of AT(1)R-ir and CYP11B-ir in the zona
glomerulosa of the fetal sheep adrenal gland would also suggest that lack of
angiotensin II stimulation of aldosterone secretion is not due to an absence of
AT(1)R or CYP11B in the zona glomerulosa.
PMID- 10684815
TI - Mouse testis brain ribonucleic acid-binding protein/translin colocalizes with
microtubules and is immunoprecipitated with messenger ribonucleic acids encoding
myelin basic protein, alpha calmodulin kinase II, and protamines 1 and 2.
AB - Testis brain RNA-binding protein (TB-RBP) is a sequence-dependent RNA-binding
protein that binds to conserved Y and H sequence elements present in many brain
and testis mRNAs. Using recombinant TB-RBP and a highly enriched tubulin
fraction, we demonstrate here that recombinant TB-RBP binds to microtubules
assembled in vitro. The interaction between recombinant TB-RBP and microtubules
was inhibited by high salt and by the microtubule disassembling agents colcemid
and calcium, but not by the microfilament-disassembling agent cytochalasin D.
Confocal microscopy confirmed colocalization of TB-RBP and tubulin in the
cytoplasm of male germ cells. An affinity-purified antibody prepared against
recombinant TB-RBP specifically precipitated mRNAs encoding myelin basic protein
and alpha calmodulin-dependent kinase II-two transported mRNAs, and protamines 1
and 2-two translationally regulated testicular mRNAs. These data indicate an
intracellular association between TB-RBP and specific target mRNAs and suggest an
involvement of TB-RBP in microtubule-dependent mRNA transport in the cytoplasm of
cells.
PMID- 10684816
TI - In vivo oxytocin release from microdialyzed bovine corpora lutea during
spontaneous and prostaglandin-induced regression.
AB - The release of luteal oxytocin during spontaneous and prostaglandin-induced
luteolysis was investigated in cows. A continuous-flow microdialysis system was
used in 11 cows to collect dialysates of the luteal extracellular space between
Days 12 and 24 postestrus. Seven cows were untreated and were expected to exhibit
spontaneous luteolysis during sampling, whereas 4 cows received prostaglandin
F(2alpha) (PGF(2alpha)) systemically between Days 13 and 15 to induce luteolysis
during sampling. Oxytocin was detectable in the dialysate of all cows before Day
16 postestrus and occurred as 2 or 3 discrete pulses per 12-h sampling period.
For non-PGF(2alpha)-treated cows, dialysate oxytocin content began to decline
spontaneously on Day 15 postestrus and was undetectable by Day 17 postestrus.
Oxytocin decay curves preceded onset of serum progesterone decline by at least 72
h and were not related temporally with onset of progesterone decline within cow.
Exogenous PGF(2alpha) (25 mg, i.m.) produced a 10-fold increase in dialysate
oxytocin within 1 h (1.9 +/- 0.3 pg/ml to 20.8 +/- 3.0 pg/ml; P < 0. 01).
Dialysate oxytocin then declined to pretreatment concentrations within 2 h and
was undetectable within 8 h posttreatment. A second PGF(2alpha) injection given
20 h after the first did not result in a measurable increase in dialysate
oxytocin, probably because luteolysis was underway. Although robust luteal
oxytocin release was observed after treatment with a pharmacological dose of
PGF(2alpha), the lack of detectable oxytocin secretion during spontaneous
luteolysis suggests that the contribution of luteal oxytocin in the cow may be
less than that proposed for the ewe.
PMID- 10684817
TI - Inhibitory and stimulatory interactions between endogenous gonadotropin-releasing
hormones in the African catfish (Clarias gariepinus).
AB - In the brain of all vertebrate classes, chicken (c) GnRH-II ([His(5),
Trp(7),Tyr(8)]GnRH, cGnRH-II) is expressed in the mesencephalon. In addition, at
least one other form of GnRH is expressed in the preoptical area/hypothalamus. In
the human pituitary stalk and the mouse median eminence, cGnRH-II is present
together with mammalian GnRH. Similarly, in the pituitary of several teleost fish
(e.g., goldfish and eel, but not salmon or trout), a teleost GnRH is found
together with cGnRH-II. These GnRHs are not colocalized in the same cells. Hence,
these GnRH peptides may differentially regulate gonadotropin secretion and, in
addition, may exert their effects simultaneously. The current study therefore
investigated the effects of combinations of the two forms of GnRH present in the
African catfish (Clarias gariepinus) pituitary-cGnRH-II and catfish GnRH
([His(5),Asn(8)]GnRH, cfGnRH)-on the cytosolic free calcium concentration
([Ca(2+)](i)) in single, Fura-2-loaded catfish gonadotrophs, as well as their
effects on both in vitro and in vivo LH secretion. Both inhibitory and
stimulatory effects of combinations of cfGnRH and cGnRH-II on [Ca(2+)](i) were
observed, which were mirrored by their effects on both in vitro and in vivo LH
secretion. The following pattern became apparent. The effect of intermediate or
maximal effective cfGnRH doses was inhibited by the simultaneous presence of
subthreshold or borderline effective cGnRH-II doses. Conversely, subthreshold or
borderline effective concentrations of cfGnRH enhanced the effects of
intermediate and maximal concentrations of cGnRH-II. In addition, combinations of
cfGnRH and cGnRH-II concentrations that were equally active when tested
separately showed an additive effect. The observed interactions between the two
GnRHs may be of particular physiological relevance in the control of seasonal LH
levels in the African catfish, as well as in other teleost species. Moreover, the
occurrence of mutual inhibitory and stimulatory interactions between endogenous
GnRHs may be a widespread aspect of GnRH action in vertebrates.
PMID- 10684818
TI - Extracellular matrix composition and hypoxia regulate the expression of HLA-G and
integrins in a human trophoblast cell line.
AB - During human placentation, extravillous cytotrophoblast cells emerge from
chorionic villi contacting the decidua to invade the uterine wall. When isolated
from first-trimester placentae, cytotrophoblast cells undergo step-wise
differentiation in vitro that recapitulates the phenotypic heterogeneity observed
in vivo. We examined a cell line, HTR-8/SVneo, that has been established from
human first-trimester cytotrophoblast to determine whether these cells possess
some of the unique cytotrophoblast characteristics that have been described
previously. Exposure during serum-free culture to hypoxic conditions (2% oxygen
concentration) increased HTR-8/SVneo cell proliferation and reduced invasion of a
three-dimensional basement membrane (Matrigel). During culture on surfaces coated
with individual extracellular matrix proteins, HTR-8/SVneo cells expressed
cytokeratin but not the trophoblast-specific major histocompatibility protein,
HLA-G. However, HLA-G expression was induced in HTR-8/SVneo cells that contacted
Matrigel. Expression of the alpha5 integrin subunit was relatively unaffected by
matrix composition, whereas alpha1 was up-regulated and alpha6 was down-regulated
after transferring cells to Matrigel. Hypoxia increased alpha6 and decreased both
alpha1 and HLA-G expression on Matrigel. HTR-8/SVneo cells retain several
important characteristics associated with primary cultures of first-trimester
human cytotrophoblast cells, including their altered behavior in response to a
changing maternal environment.
PMID- 10684819
TI - Connexin gene expression in seminiferous tubules of the Sprague-Dawley rat.
AB - Sertoli and spermatogenic cells establish germ cell- and epithelial stage
dependent networks of cell-cell communication thought to be important for the
initiation and maintenance of spermatogenesis. Since gap junctions assemble
between Sertoli cells and between Sertoli and spermatogenic cells, it was
hypothesized that multiple, unique routes of cell-cell communication may be
established, in part, by the assembly of structurally diverse gap junctions from
the connexin (Cx) multigene family. Differences in channel structure may support
differences in ion or second messenger permeability between cell types. Reverse
transcription-polymerase chain reaction (RT-PCR) analyses showed that 11 Cx mRNAs
were present in total RNA from seminiferous tubules and that 10 of the Cx mRNAs
were present in polysomes and presumably translated. RT-PCR analyses also showed
that the Cx mRNA population varied between different seminiferous tubule cell
types. There were 9 Cx mRNAs in germ cells, 8 in Sertoli cells, and 5 in
peritubular cells. One of the Cx mRNAs, Cx-50, was detected only in pachytene
spermatocytes and round spermatids. Comparisons of the Cx mRNAs present in
tubules at different postnatal ages showed that at least 2 Cxs (Cx-33 and Cx-50)
accumulated when leptotene-zygotene stages developed. The multiple Cx genes and
proteins produced in spermatogenesis may support the assembly of structurally
diverse gap junctions.
PMID- 10684820
TI - Polarized distribution of NHE1 and NHE2 in the rat epididymis.
AB - Previous studies from our laboratory have provided evidence that the rat
epididymis utilizes the Na(+)/H(+) exchanger to transport acid and base. The
present study was undertaken to use immunohistochemistry for investigating the
localization (apical versus basolateral) and distribution of NHE1 and NHE2
proteins along intact rat epididymis. Both proteins were found to be exclusively
localized within the epithelium. Immunoreactivity for NHE1 was detected on the
basolateral surface, whereas NHE2 immunoreactivity was detected on the apical
side of the epithelium. Interestingly, NHE1 was found along the entire length of
the epididymal tubule whereas NHE2 was absent in the initial segment but present
in the caput, corpus, and cauda regions. These results, when interpreted along
with those of previous functional studies, may suggest that the apical NHE2 is
involved in Na(+) reabsorption and the basolateral NHE1 in HCO(3)(-) secretion in
the rat epididymis.
PMID- 10684821
TI - Evidence for progesterone receptors in the human fetoplacental vascular tree.
AB - The presence of progesterone receptors (PR) throughout the human term
fetoplacental vascular tree was investigated. By reverse transcription-polymerase
chain reaction (RT-PCR), we showed expression of PR mRNAs in stem villi vessels,
chorionic arteries and veins, and umbilical arteries and veins. Binding studies
and Scatchard analysis revealed a single class of high-affinity binding sites for
(3)H-R5020 (promegestone) in cytosolic extracts of all placental vessels, with
K(d) values in the range of 2.5-4 nM. High levels of PR were detected in
placental vessels compared to other vascular tissues. Thus, maximum binding
capacities of stem villi vessels, chorionic arteries and veins, and umbilical
arteries and veins were 247 +/- 25, 377 +/- 58, 295 +/- 40, 371 +/- 118, and 672
+/- 144 fmol/mg protein, respectively. Endothelial cell elimination in chorionic
arteries did not significantly modify the number of PR. RT-PCR and binding
studies also assessed PR expression in cultured placental vascular smooth muscle
cells isolated from stem villi vessels. All these data suggested that most of the
PR of fetoplacental vessels were from the media. In conclusion, we report here
the first evidence of the presence of PR in the muscular layer of human term
fetoplacental vessels. This finding, together with the high progesterone
concentrations in cord blood, suggests that the interactions between the PR and
its ligand may play a role in the physiology and physiopathology of human
fetoplacental vascularization.
PMID- 10684822
TI - Independent and hetero-oligomeric-dependent sperm binding to egg envelope
glycoprotein ZPC in Xenopus laevis.
AB - Vitelline envelopes are composed of glycoproteins that participate in sperm-egg
interactions during the initial stages of fertilization. In Xenopus laevis, the
vitelline envelope is composed of at least 4 glycoproteins (ZPA, ZPB, ZPC, and
ZPX). A sperm binding assay involving the covalent coupling of envelope
glycoproteins to silanized glass slides was developed. In our assay, sperm bound
to the egg envelopes derived from oviposited eggs but not activated eggs. The
majority of the egg envelope ligand activity for sperm binding was derived from
the complex N-linked oligosaccharides of ZPC. This sperm binding involved N
acetylglucosamine and fucose residues, as binding was abolished after treatment
with cortical granule beta-N-acetylglucosaminidase and commercial beta-N
acetylglucosaminidases and was reduced by 44% after treatment with alpha
fucosidase. Although both the envelope glycoproteins ZPA and ZPC possessed
independent ligand activity, ZPC was the major ligand for sperm binding (75%).
Mixing of isolated ZPA, ZPB, and ZPC in a ratio of 1:4:4 (equal to that in the
egg envelope) resulted in sperm binding that was greater than that of the sum of
the separate components. The egg glycoproteins acted in synergy to increase sperm
binding. Thus, ZPC possessed both independent and hetero-oligomeric-dependent
ligand activities for sperm binding.
PMID- 10684823
TI - Meiosis-activating sterol-mediated resumption of meiosis in mouse oocytes in
vitro is influenced by protein synthesis inhibition and cholera toxin.
AB - To explore the possible signaling pathways of meiosis-activating sterol (MAS)
induced oocyte maturation and to elucidate whether the MAS pathway involves
transcription or translation, arrested immature mouse oocytes were cultured with
either the protein synthesis inhibitor cycloheximide or the heteronuclear RNA
inhibitors alpha-amanitin or actinomycin D, respectively. Moreover, the possible
involvement of a G protein-coupled receptor mechanism in MAS-mediated oocyte
maturation was explored by influencing oocyte maturation with cholera toxin (CT).
MAS-induced oocyte maturation was completely blocked by the addition of 50
microg/ml cycloheximide 4 h before the addition of MAS. Simultaneous addition of
MAS and the protein synthesis inhibitor also significantly reduced the meiotic
resumption compared to that in MAS-treated controls. In contrast, neither of the
treatment regimens to inhibit transcription of DNA to RNA was observed to have
any effect on the MAS-induced resumption of meiosis. CT was observed to inhibit
MAS-induced, but not spontaneous, oocyte maturation in vitro, suggesting a
putative involvement of G protein-coupled receptor mechanism in the MAS mode of
action. In conclusion, protein synthesis was found to be an essential requirement
for maintaining the oocytes' responsiveness to MAS-induced resumption of meiosis,
in contrast to transcription.
PMID- 10684824
TI - Endothelial vasodilator production by uterine and systemic arteries. IV.
Cyclooxygenase isoform expression during the ovarian cycle and pregnancy in
sheep.
AB - Uterine artery endothelial production of the potent vasodilator, prostacyclin, is
greater in pregnant versus nonpregnant sheep and in whole uterine artery from
intact versus ovariectomized ewes. We hypothesized that uterine artery
cyclooxygenase (COX)-1 and/or COX-2 expression would be elevated during pregnancy
(high estrogen and progesterone) and the follicular phase of the ovarian cycle
(high estrogen/low progesterone) as compared to that in luteal phase (low
estrogen/high progesterone) or in ovariectomized (low estrogen and progesterone)
ewes. Uterine and systemic (omental) arteries were obtained from nonpregnant
luteal-phase (LUT; n = 10), follicular-phase (FOL; n = 11), and ovariectomized
(OVEX; n = 10) sheep, as well as from pregnant sheep (110-130 days gestation;
term = 145 +/- 3 days; n = 12). Endothelial and vascular smooth muscle (VSM) COX
1 protein levels and uterine artery endothelial cell COX-1 mRNA levels were
compared. Using immunohistochemistry and Western analysis, the primary location
of COX-1 protein was the endothelium; that is, we observed 2.2-fold higher COX-1
protein levels in intact versus endothelium-denuded uterine artery and a 6.1-fold
higher expression in the endothelium versus VSM (P < 0.05). COX-2 protein
expression was not detectable in either uterine artery endothelium or VSM. COX-1
protein levels were observed to be higher (1.5-fold those of LUT) in uterine
artery endothelium from FOL versus either OVEX or LUT nonpregnant ewes (P <
0.05), with substantially higher COX-1 levels seen in pregnancy (4.8-fold those
of LUT). Increases in uterine artery endothelial COX-1 protein were highly
correlated to increases in the level of COX-1 mRNA (r(2) = 0.66; P < 0.01) for
all treatment groups (n = 6-8 per group), suggesting that increased COX-1 protein
levels are regulated at the level of increased COX-1 mRNA. No change in COX-1
expression was observed between groups in a systemic (omental) artery. In
conclusion, COX-1 expression is specifically up-regulated in the uterine artery
endothelium during high uterine blood flow states such as the follicular phase
and, in particular, pregnancy.
PMID- 10684825
TI - Expression of deoxyribonucleic acid repair enzymes during spermatogenesis in
mice.
AB - Meiotic recombination during gametogenesis is critical for proper chromosome
segregation. However, the participating proteins and mechanics of recombination
are not well understood in mammals. DNA repair enzymes play an essential role in
both mitosis and meiosis in yeast. The mammalian mismatch repair system consists
of homologues of the bacterial MutH, MutL, and MutS proteins. As part of our goal
of understanding the function of enzymes that mediate meiotic recombination, we
used a reverse transcription-polymerase chain reaction approach to identify germ
cell transcripts for the MutL homologue, Pms2, and two members of the MutS
family, Msh2 and Msh3. Both the Pms2 and the Msh2 genes were highly expressed in
mitotically proliferating spermatogonia, and early in meiotic prophase in the
leptotene and zygotene spermatocytes. Thereafter, expression declined in early
and mid pachytene spermatocytes, and was negligible in postmeiotic spermatids. In
contrast, expression of Msh3 was at its highest level in pachytene spermatocytes.
Protein levels were similar to gene expression patterns, and both PMS2 and MSH2
were localized in spermatogonia and spermatocytes. These patterns of expression
for genes encoding mismatch repair enzymes are consistent with the proposed roles
of the gene products in mismatch repair during both DNA replication and
recombination.
PMID- 10684826
TI - Fetal-to-maternal progression of prostaglandin H(2) synthase-2 expression in
ovine intrauterine tissues during the course of labor.
AB - We examined whether spontaneous parturition in sheep was associated with tissue
specific changes in prostaglandin H(2) synthase-2 (PGHS-2) expression and/or with
altered expression of myometrial EP and FP receptors. Placental and uterine
tissues were collected from three groups of chronically catheterized sheep in
relation to term spontaneous labor: late pregnancy, not in labor; early labor;
and active labor. Expression of PGHS-2 mRNA and protein was determined by in situ
hybridization, Western blotting, and immunohistochemistry. Semiquantitative
reverse transcription-polymerase chain reaction was used to assess the presence
of and changes in prostaglandin (PG) receptor subtypes. In placenta, PGHS-2 mRNA
and protein localized to trophoblast uninucleate cells and tended to increase
with early labor. PGHS-2 mRNA and protein localized to endometrial epithelium and
to myometrium, where PGHS-2 protein levels rose in active labor tissues.
Concentrations of PGE(2) in fetal plasma rose progressively with labor, whereas
13,14-dihydro-15-keto-PGF(2alpha) in maternal plasma increased significantly only
in active labor. Messenger RNA encoding four EP receptor subtypes and FP receptor
were present in myometrium, but levels did not change with labor. We suggest that
spontaneous labor in sheep is associated with a progressive increase in PGHS-2
expression in a temporal and tissue-specific manner from trophoblast to maternal
tissues, rather than alteration in PG receptor gene expression.
PMID- 10684827
TI - Testosterone-dependent primer pheromone production in the sebaceous gland of male
goat.
AB - To test the hypothesis that the primer pheromone responsible for inducing the
"male effect" is produced in the sebaceous gland androgen dependently, we
examined the correlation between morphological changes of sebaceous glands and
the pheromone activity in skin samples taken from castrated goats that had been
treated with testosterone. Five castrated goats were implanted s.c. with
testosterone capsules to maintain physiological levels of plasma testosterone for
four weeks. Skin samples were obtained from the head region on Day 0 (the day of
testosterone implant), Day 7, Day 14, Day 28 (the day of testosterone removal),
Day 36, Day 42, and Day 56. Matched blood samples were also collected for
measurement of testosterone concentration. The pheromone activity of the ether
extracts of the upper dermal layer containing sebaceous glands was assessed by
its stimulatory effect on the hypothalamic GnRH pulse generator, which was
monitored for changes of specific multiple unit activity (MUA) in ovariectomized
estradiol-primed goats as described previously. The sebaceous gland enlarged
during the testosterone treatment but reduced in size after testosterone removal.
The pheromone activity first appeared in 2 out of 5 goats on Day 7 and in all the
5 goats by Day 28. Fourteen days after testosterone removal (Day 42), the
pheromone activity was no longer detectable in any of the 5 goats. In short, the
sebaceous gland size and the pheromone activity shifted almost in parallel. The
present results provide strong support for the view that the primer pheromone is
produced testosterone dependently in the sebaceous gland of the male goat.
PMID- 10684828
TI - Involvement of protein kinase A and A kinase anchoring protein in the
progesterone-initiated human sperm acrosome reaction.
AB - The signal transduction pathways involved in the progesterone (P(4))-initiated
mammalian sperm acrosome reaction (AR) are not fully understood. To investigate
the role of the protein kinase A (PKA) pathway in the P(4)-initiated AR, we
probed this pathway by pretreating capacitated human sperm with reagents designed
to either inhibit PKA activation or disrupt PKA/A kinase anchoring protein (AKAP)
interactions. Preincubation with the stearated (membrane permeable) PKA
inhibitor, PKI alpha 5-24 (S-PKI alpha 5-24), significantly inhibited the P(4)
initiated AR at 10 microM as compared to stearated control peptide. In contrast,
preincubation with 100 microM nonstearated PKI alpha 5-24 did not significantly
inhibit versus solvent control. Preincubation with the PKA inhibitor Rp-8-Br-cAMP
at 500 microM and 150 microM significantly inhibited the P(4)-initiated AR versus
8-Br-cAMP and versus solvent. Preincubation with the anchoring inhibitory peptide
S-Ht-31 significantly stimulated the P(4)-initiated AR at 10, 3, and 1 microM
versus inactive control peptide. The stimulation of the P(4)-initiated AR by 3
microM S-Ht31 was significantly inhibited by the addition of 30 microM S-PKI
alpha 5-24 prior to the addition of S-Ht31. Preincubation with S-PKI alpha 5-24
(30 microM) partially inhibited the ionomycin (50 microM)-initiated AR. A role
for PKA in the P(4)-initiated AR may exist both upstream and downstream of Ca(2+)
entry. Our studies present the first evidence for the participation of PKA in the
P(4)-initiated AR and also suggest that AKAPs are involved in the PKA-mediated
events.
PMID- 10684829
TI - Uveitis in HIV positive patients.
PMID- 10684830
TI - Open invitation from the International Poverty and Health Network to all health
professionals.
PMID- 10684831
TI - Clinicopathological correlation in exudative age related macular degeneration:
histological differentiation between classic and occult choroidal
neovascularisation.
AB - AIMS: To analyse the histopathology of classic and occult choroidal neovascular
membrane surgical specimens in age related macular degeneration. METHODS: 35
membranes, from a consecutive series of surgically removed choroidal neovascular
membranes in age related macular degeneration, were classified as classic or
occult following the guidelines of the Macular Photocoagulation Study. Membranes
with classic as well as occult components were considered as mixed membranes. The
membranes were serially sectioned and stained with haematoxylin and eosin, Masson
trichrome, periodic acid-Schiff, and phosphotungstic acid haematoxylin stain. The
correlation has been made in a masked fashion. RESULTS: 31 membranes (19 classic,
10 occult, and two mixed membranes) could be analysed histologically. 18 classic
choroidal neovascular membranes had a major subretinal fibrovascular component
and 10 of these had an additional, minor fibrovascular component under the
retinal pigment epithelium. The 10 occult membranes contained a fibrovascular
component under the retinal pigment epithelium and the two mixed membranes
contained fibrovascular tissue on both sides of the retinal pigment epithelium.
Fibrin and remains of outer segments tended to occur at the lateral edges of
classic membranes and to cover the inner surface of occult membranes. CONCLUSION:
Classic choroidal neovascularisation in age related macular degeneration is
predominantly composed of subretinal fibrovascular tissue while occult choroidal
neovascularisation is composed of fibrovascular tissue at the choroidal side of
the retinal pigment epithelium.
PMID- 10684832
TI - Macular degeneration: do conventional measurements of impaired visual function
equate with visual disability?
AB - AIMS: To examine the relation between measures of vision and ability to perform
daily living tasks in those visually impaired with macular degeneration. METHODS:
A visual functioning index (daily living tasks dependent on vision: DLTV) was
used to evaluate patients' perception of their ability to perform vision
dependent tasks. Distance visual acuity, near visual acuity, reading speed, and
contrast sensitivity were measured in all patients. In addition, a new measure of
reading ability was derived, designated the reading index. This takes into
account both the size of the text read and the time to read it and is equivalent
to the reading speed in words per minute divided by text size in M. RESULTS: The
reading index was found to show best associations with the majority of items
within the DLTV. Stepwise regression identified the combination of reading index
and distance visual acuity as having the best associations with DLTV items. The
present study also demonstrated that specific levels of vision as measured by
acuity, reading index, and contrast sensitivity corresponded with different
perceived amounts of difficulty in the performance of daily living tasks.
CONCLUSIONS: This study showed that reading index is valuable in predicting the
ability to perform daily living tasks and therefore may be useful in the visual
assessment of the visually impaired individual. In addition, this study
identified specific levels of vision at which individuals reported different
degrees of difficulty in performing daily living tasks.
PMID- 10684833
TI - Radiological and clinicopathological features of orbital xanthogranuloma.
AB - BACKGROUND: Orbital xanthogranuloma, a diagnosis confirmed histologically, occurs
rarely in adults and children. With its characteristic macroscopic appearance the
adult form may be associated with a spectrum of biochemical and haematological
abnormalities including lymphoproliferative malignancies. METHOD: The
clinicopathological features and imaging appearances on computed tomography and
magnetic resonance imaging of this condition are described in eight adults and a
child. RESULTS: Radiological evidence of proptosis was present in seven patients.
In all nine patients an abnormal infiltrative soft tissue mass was seen, with
increased fat in six cases. All patients had associated enlargement of
extraocular muscles suggestive of infiltration and five had lacrimal gland
involvement. Encasement of the optic nerve, bone destruction, and intracranial
extension was present only in the child with juvenile xanthogranuloma.
Haematological and/or biochemical abnormalities were detected in seven patients
and seven patients had other systemic diseases which were considered to have an
immune basis. One patient subsequently developed non-Hodgkin's lymphoma.
CONCLUSION: The investigation and management of orbital xanthogranulomas requires
a multidisciplinary approach even though the diagnosis may be suspected
clinically. Imaging delineates the extent of disease and involvement of local
structures and may influence the differential diagnosis. The juvenile form may be
more locally aggressive, causing bone destruction with consequent intracranial
extension.
PMID- 10684834
TI - Prospective surveillance of sympathetic ophthalmia in the UK and Republic of
Ireland.
AB - AIMS: To establish current epidemiological data, risks, and interventional
outcomes of newly diagnosed sympathetic ophthalmia (SO). METHODS: Prospective
surveillance took place of all permanently employed ophthalmologists in the UK
and Republic of Ireland by a monthly reporting card through the British
Ophthalmological Surveillance Unit. Case ascertainment was made of newly
diagnosed SO from July 1997 and questionnaire data were returned at baseline, 6
months, and 1 year after diagnosis. RESULTS: 23 patients with newly diagnosed SO
were recruited over 15 months, corresponding to a minimum estimated incidence of
0.03/100 000. Baseline data were available on 18 patients, in whom SO occurred
after surgery in 11 patients, after retinal surgery alone in six patients, and
after accidental trauma in seven patients. 12 of the 16 patients with 1 year
follow up had a visual acuity of 6/12 or better. Good visual outcome was related
to prompt and adequate systemic immunosuppressive therapy. CONCLUSIONS: The
incidence of sympathetic ophthalmia is very low. The main current risk is
surgery, particularly retinal surgery, but visual prognosis is good if early
diagnosis is made and rapid, adequate immunotherapy is commenced.
PMID- 10684835
TI - Scanning laser polarimetry in normal subjects and patients with myopia.
AB - AIMS: To examine the changes in the retinal nerve fibre layer (NFL) thickness
with age and myopia in normal population. METHODS: Retinal nerve fibre layer
thickness was measured with a scanning laser polarimeter (NFA-I) in 180 normal
subjects of varying age (range 7-83 years) and in 110 eyes of 85 patients with
myopia of varying degrees (range -1.00 to -15.00D). They were all voluntary
Anatolian people. Superior to nasal (S/N), inferior to nasal (I/N), and the
superior to inferior (S/I) ratios were used for the assessment of retinal NFL
thickness. RESULTS: The mean superior NFL ratio was 2.96 and the mean inferior
NFL ratio was 2.93 in normal subjects. There was a gradual decrease in NFL ratio
with increasing age (simple regression analysis, p<0.05). The mean S/I ratio was
1.01 with a large variation. In patients with myopia, the mean superior NFL ratio
was 2.60 and the mean inferior NFL ratio was 2.72. Superior and inferior NFL
retardations, and S/I ratio in myopic patients were significantly (15.5%, 10.8%,
and 4.9% respectively) lower than that of age matched normals (t test, p<0.05).
There was also a gradual decrease in NFL thickness with increasing degree of
myopia (simple regression analysis, p<0.05). CONCLUSIONS: Nomograms we obtained
for retinal NFL thickness may serve as reference points for the assessment of
normal Anatolian people and myopic patients in future studies. NFL thicknesses
gradually decreased with increasing age. Patients with myopia had significantly
lower NFL thicknesses than normal subjects and, although weakened by wide age
range of myopic group, there is a linear relation between severity of myopia and
NFL thickness in myopic patients.
PMID- 10684836
TI - Treatment of conjunctival squamous cell carcinoma with topical 5-fluorouracil.
AB - AIM: To evaluate the efficacy of topical 5-fluorouracil (5-FU) alone, without
concurrent surgery or radiotherapy, for the treatment of conjunctival squamous
cell carcinoma. METHODS: Eight patients affected by conjunctival squamous cell
carcinoma (three recurrent cases, three incompletely excised, and two untreated
cases) were treated with 1% 5-FU eye drops. Topical 1% 5-FU was administered four
times daily for 4 weeks (one course). Clinical examination (biomicroscopy and
photography) and morphological evaluation of conjunctival cytological specimens
were used to monitor the efficacy of local chemotherapy, side effects, and
recurrences. RESULTS: All patients showed clinical regression of conjunctival
carcinoma after topical 1% 5-FU treatment. Neoplastic conjunctiva was completely
replaced by normal epithelium within 3 months. Mean follow up was 27 months. One
patient needed two courses of local chemotherapy for recurrent disease. An acute
transient toxic keratoconjunctivitis was observed in all treated cases; it was
easily controlled with topical therapy. No long term side effects were found.
CONCLUSIONS: Topical 1% 5-FU is effective in the treatment of recurrent,
incompletely excised, and selected untreated conjunctival squamous cell
carcinomas. Topical 1% 5-FU has no major complications. This study suggests that
topical conjunctival chemotherapy with 1% 5-FU may be useful, at least as
adjunctive therapy, in the treatment of conjunctival squamous cell carcinoma.
PMID- 10684837
TI - Autologous limbal transplantation in patients with unilateral corneal stem cell
deficiency.
AB - AIM: To describe a surgical technique for autologous limbal stem cell
transplantation and the outcome of a series of patients with unilateral stem cell
deficiency. METHODS: A report of six consecutive patients who underwent
autologous limbal stem cell transplantation is presented. The primary diagnosis
included alkali burn (n=3), conjunctival intraepithelial neoplasia (CIN) (n=1),
recurrent pterygium (n=1), and contact lens induced keratopathy (n=1). The
autologous transplanted tissue consisted of peripheral cornea, limbus, and
conjunctiva obtained from the contralateral eye. Three of the above patients
underwent penetrating keratoplasty in association with auto-limbal
transplantation. A significant modification to established techniques was the
close monitoring of conjunctival epithelial migration in the immediate
postoperative period. If conjunctival epithelium threatened to migrate on to the
corneal surface, it was mechanically removed at the slit lamp and prevented from
crossing the limbus. This was required in three patients. RESULTS: The mean
follow up was 18.8 months. The outcome was satisfactory in all cases: a stable
corneal surface was restored and there was a substantial improvement in vision
and symptoms. One patient had a primary failure of the corneal allograft
associated with glaucoma, and 6 months later developed a retinal detachment. No
complications were noted in the donor eye with the exception of one patient who
developed filamentary keratitis along the edge of the donor site. CONCLUSION:
Autologous limbal transplantation with corneal, limbal, and conjunctival carriers
was found to be useful for ocular surface reconstruction, over a mid-term follow
up, in patients with unilateral stem cell deficiency. Close monitoring of the
migration of conjunctival epithelium in the immediate postoperative period, and
preventing it from crossing the limbus, ensured that the corneal surface was re
epithelialised exclusively from epithelial cells derived from the transplanted
limbal tissue. This approach should improve the success of this procedure.
PMID- 10684838
TI - Long term results after autologous nasal mucosal transplantation in severe mucus
deficiency syndromes.
AB - AIM: Severe mucus deficiency syndromes may require substitution of mucous
membrane for re-establishment of the ocular surfaces. The long term results after
autologous nasal mucosal transplantation were investigated. METHODS: 55 eyes of
50 patients with severe mucus deficiency syndromes were followed retrospectively
after free autologous nasal mucosal transplantation-group A: patients after
severe lye, acid, heat burns, or radiation (n=38 eyes), group B: patients with
systemic mucosal disease (n=17 eyes). The results of routine clinical examination
were recorded and patients were followed for a median of 37 months. 17 biopsies
of transplanted nasal mucosa were studied by light microscopy and 22 patients by
impression cytology before and at several intervals after mucosal
transplantation. RESULTS: All nasal mucosal grafts healed well and no
intraoperative complications occurred. During follow up 107 additional surgical
procedures were performed including 16 lamellar and 21 penetrating
keratoplasties. Subjective complaints improved in 44/47 patients with
preoperative symptoms. Best corrected visual acuity at the end of follow up was
increased in 23 eyes, 10 eyes (18. 2%) reached a final visual acuity equal to or
greater than 20/200. Histopathologically, all (n=17) biopsies showed vital
intraepithelial mucin producing goblet cells in the nasal mucosal graft (median
25 cells/field (400x magnification)). The mean density of goblet cells before
transplantation was 48/mm(2) and after nasal mucosal grafting 432/mm(2) measured
by impression cytology (p<0. 0001). CONCLUSIONS: Functional goblet cells persist
in autologous nasal mucosa for up to 10 years after transplantation. In patients
with severe mucus deficiency syndromes of different origin nasal mucosal
transplantation can re-establish the ocular surface, substitute the mucus
components of the tear film, improve symptoms of the patients, and facilitate a
moderate increase in visual acuity.
PMID- 10684839
TI - Clinical course of hurricane keratopathy.
AB - BACKGROUND/AIMS: "Hurricane keratopathy" is the name given to the whorl pattern,
highlighted with fluorescein, seen in situations where corneal epithelial cell
turnover is exaggerated. Although the condition is well described, follow up data
on patients with this condition and its sequelae have only been reported in
corneal graft patients. The aim was to study the clinical course of hurricane
keratopathy in corneal graft patients and contact lens wearers, and to document
any sequelae of this condition. METHODS: Hurricane keratopathy, occurring in 20
eyes with corneal grafts and 16 eyes (six bilateral) wearing rigid gas permeable
contact lenses, was studied and followed. The occurrence, pattern, progress,
resolution, and residual effects of the whorls were noted. RESULTS: Hurricane
keratopathy was noted to occur in grafts as previously reported and also in
contact lens wearers, which has hitherto not been reported. The whorls usually
appeared within the first 3 weeks postoperatively and persisted up to 4 months. A
small epithelial defect (11.1%), heaped epithelial cells (5.6%), and a nebular
grade opacity (2.8%), were the only significant sequelae noted at the epicentre
of the whorls. Resolution occurred from the periphery towards the centre of the
cornea. CONCLUSIONS: The whorl pattern is sustained as long as the stimulus for
increased cell turnover is maintained. Once this stimulus is eliminated, the
pattern tends to resolve spontaneously.
PMID- 10684840
TI - Epidemiology of pterygium in Victoria, Australia.
AB - AIM: To describe the prevalence of and risk factors for pterygium in a population
based sample of residents of the Australian state of Victoria who were aged 40
years and older. METHODS: The strata comprised nine randomly selected clusters
from the Melbourne statistical division, 14 nursing homes randomly selected from
the nursing homes within a 5 kilometre radius of the nine Melbourne clusters, and
four randomly selected clusters from rural Victoria. Pterygium was measured in
millimetres from the tip to the middle of the base. During an interview, people
were queried about previous ocular surgery, including surgical removal of
pterygium, and their lifetime exposure to sunlight. RESULTS: 5147 people
participated. They ranged in age from 40 to 101 years and 2850 (55.4%) were
female. Only one person in the Melbourne cohort reported previous pterygium
surgery, and seven rural residents reported previous surgery; this information
was unavailable for the nursing home residents. Pterygium was present upon
clinical examination in 39 (1.2%) of the 3229 Melbourne residents who had the
clinical examination, six (1. 7%) of the nursing home residents, and 96 (6.7%) of
the rural residents. The overall weighted population rate in the population was
2.83% (95% CL 2.35, 3.31). The independent risk factors for pterygium were found
to be age (OR=1.23, 95% CL=1.06, 1.44), male sex (OR=2.02, 95% CL=1.35, 3.03),
rural residence (OR=5.28, 95% CL=3. 56, 7.84), and lifetime ocular sun exposure
(OR=1.63, 95% CL=1.18, 2. 25). The attributable risk of sunlight and pterygium
was 43.6% (95% CL=42.7, 44.6). The result was the same when ocular UV-B exposure
was substituted in the model for broad band sun exposure. CONCLUSION: Pterygium
is a significant public health problem in rural areas, primarily as a result of
ocular sun exposure.
PMID- 10684841
TI - Effects of topical nipradilol, a beta blocking agent with alpha blocking and
nitroglycerin-like activities, on intraocular pressure and aqueous dynamics in
humans.
AB - AIMS: To study the effects of topical nipradilol, a non-selective beta blocker
with alpha blocking and nitroglycerin-like activities, on intraocular pressure
(IOP) and aqueous humour dynamics in normal humans and in patients with ocular
hypertension. METHODS: Nipradilol (0.06%, 0.125%, 0.25%, 0.5%) was applied to
normal volunteers (n = 12) to test for IOP lowering effects. In a second group of
normal volunteers (n = 11), nipradilol (0.125% and 0.25%) and timolol (0. 5%)
were compared for IOP lowering effects. After a single administration of 0.25%
nipradilol, IOP, flare intensity in the anterior chamber, aqueous flow,
uveoscleral outflow, tonographic outflow facility, and episcleral venous pressure
were either directly measured or mathematically calculated. Topical nipradilol
(0.25%) was administered to 24 patients with ocular hypertension twice daily for
8 weeks. RESULTS: Administration of 0.25% nipradilol decreased IOP with a maximum
reduction of 4.2 mm Hg lasting 12 hours. A single instillation of both 0.25%
nipradilol and 0.5% timolol reduced the IOP in normotensive human subjects to the
same degree. A single instillation of 0.25% nipradilol decreased the aqueous flow
rate in the treated eye by 20%. Nipradilol produced no significant effect in
tonographic outflow facility or episcleral venous pressure, but uveoscleral
outflow was increased. In patients with ocular hypertension, twice daily
instillation of 0.25% nipradilol decreased IOP without tachyphylaxis for the 8
week test period. CONCLUSION: Topical nipradilol (0.25%) reduced IOP by
decreasing the aqueous flow rate and probably also by increasing uveoscleral
outflow. Nipradilol should be further investigated as a new antiglaucoma drug.
PMID- 10684842
TI - Intraocular penetration of vancomycin eye drops after application to the medial
canthus with closed lids.
AB - AIMS: To investigate the intraocular penetration of vancomycin eye drops and to
compare the conventional method of drop instillation to the lower cul de sac with
applying drops to the medial canthus with closed lids. METHODS: This prospective
randomised trial evaluated 53 eyes of 53 patients who had undergone extracapsular
cataract extraction (ECCE) with intraocular lens implantation. Vancomycin (50
mg/ml) eye drops were applied to either the lower cul de sac with open lids
(conventional method), or to the medial canthus with the patient in a supine
position and with closed lids. After paracentesis performed during ECCE, an
aqueous humour sample was taken and vancomycin concentration was measured using
the TDX vancomycin assay (fluorescence polarisation immunoassay). RESULTS:
Vancomycin concentration in the anterior chamber were above the minimal
inhibitory concentration for Gram positive bacteria in the two methods of drop
instillation examined (2.04 (SD 1.9) microg/ml and 1.49 (1.1) microg/ml in the
open and closed methods, respectively (p =0.202)). CONCLUSIONS: Vancomycin (50
mg/ml) reaches therapeutic concentration in the anterior chamber after topical
drop application. Comparable concentrations were reached when drops were applied
in either the lower cul de sac or to the medial canthus with closed lids. The
latter method is proposed as likely to improve patient compliance.
PMID- 10684843
TI - Retinal ganglion cell death in experimental glaucoma.
AB - AIMS: To determine whether parasol retinal ganglion cells (magnocellular pathway)
are selectively lost in the primate model of glaucoma. METHODS: Ocular
hypertension was induced in one eye of six Macaca fascicularis monkeys for 6-14
weeks. The retinal ganglion cells in these eyes were labelled retrogradely with
the tracer horseradish peroxidase (HRP) implanted into the optic nerve and
subsequently examined in retinal whole mount preparations. The degree of retinal
ganglion cell loss was estimated from Nissl stained tissue by comparison with the
contralateral untreated control eye. RESULTS: In the three glaucomatous retinas
with the best labelling 1282 cells could be classified, of which 182 were parasol
cells and 1100 were midget cells. Linear regression analysis did not demonstrate
a significant reduction in the proportion of parasol to midget cells with
increasing cell loss (regression slope 0.023, 95% CI -0.7 to 0.11). Compared with
the control eye the cell soma of the remaining retinal ganglion cells in
glaucomatous eyes were reduced in size by 20% for parasol cells (p=0.003) and by
16% for midget cells (p <0.001). CONCLUSION: The results of this study do not
support the hypothesis that selective loss of parasol retinal ganglion cells
occurs in experimental glaucoma. In addition, the change in cell soma size
distributions following ocular hypertension suggests that both parasol and midget
retinal ganglion cells undergo shrinkage before cell death.
PMID- 10684844
TI - Age related changes in the non-collagenous components of the extracellular matrix
of the human lamina cribrosa.
AB - AIMS: To investigate age related alterations in the non-collagenous components of
the human lamina cribrosa. METHODS: Fibronectin, elastin, and glial fibrillary
acidic protein (GFAP) staining were assessed in young and old laminae cribrosae.
An age range (7 days to 96 years) of human laminae cribrosae were analysed for
lipid content (n=9), cellularity (n=28), total sulphated glycosaminoglycans
(n=28), elastin content (n=9), and water content (n=56), using chloroform
methanol extraction, fluorimetry, the dimethylmethylene blue assay, and ion
exchange chromatography, respectively. RESULTS: Qualitatively, an increase in
elastin and a decrease in fibronectin and GFAP were demonstrated when young
tissue was compared with the elderly. Biochemical analysis of the ageing human
lamina cribrosa demonstrated that elastin content increased from 8% to 28% dry
tissue weight, total sulphated glycosaminoglycans decreased, and lipid content
decreased from 45% to 25%. There were no significant changes in total cellularity
or water content. CONCLUSION: These alterations in composition may be indicative
of the metabolic state of the lamina cribrosa as it ages, and may contribute to
changes in mechanical integrity. Such changes may be implicated in the
susceptibility of the elderly lamina cribrosa and also its response to
glaucomatous optic neuropathy.
PMID- 10684845
TI - Age related compliance of the lamina cribrosa in human eyes.
AB - AIMS: To investigate changes in the mechanical compliance of ex vivo human lamina
cribrosa with age. METHODS: A laser scanning confocal microscope was used to
image the surface of the fluorescently labelled lamina cribrosa in cadaver eyes.
A method was developed to determine changes in the volume and strain of the
lamina cribrosa created by increases in pressure. The ability of the lamina
cribrosa to reverse its deformation on removal of pressure was also measured.
RESULTS: Volume and strain measurements both demonstrated that the lamina
cribrosa increased in stiffness with age and the level of pressure applied. The
ability of the lamina cribrosa to regain its original shape and size on removal
of pressure appeared to decrease with age, demonstrating an age related decrease
in resilience of the lamina cribrosa. CONCLUSIONS: The mechanical compliance of
the human lamina cribrosa decreased with age. Misalignment of compliant
cribriform plates in a young eye may exert a lesser stress on nerve axons, than
that exerted by the rigid plates of an elderly lamina cribrosa. The resilience of
the lamina cribrosa also decreased with age, suggesting an increased
susceptibility to plastic flow and permanent deformation. Such changes may be of
importance in the explanation of age related optic neuropathy in primary open
angle glaucoma.
PMID- 10684846
TI - Effect of spectacles on changes of spherical hypermetropia in infants who did,
and did not, have strabismus.
AB - AIM: To explore why emmetropisation fails in children who have strabismus.
METHODS: 289 hypermetropic infants were randomly allocated spectacles and
followed. Changes in spherical hypermetropia were compared in those who had
strabismus and those who did not. The effect of wearing glasses on these changes
was assessed using t tests and regression analysis. RESULTS: Mean spherical
hypermetropia decreased in both eyes of "normal" children (p<0.001). The
consistent wearing of glasses impeded this process in both eyes (p<0.007). In the
children with strabismus, there were no significant changes in either eye,
irrespective of treatment (p>0. 05). CONCLUSIONS: In contrast with normal
infants, neither eye of those who had strabismus emmetropised, irrespective of
whether the incoming vision was clear or blurred. It is suggested that these eyes
did not "recognise" the signal of blurred vision, and that they remained long
sighted because they were destined to squint. Hence, the children did not squint
because they were long sighted, and glasses did not prevent them squinting.
PMID- 10684847
TI - Extended wear contact lens related bacterial keratitis.
AB - AIMS: To report the clinical findings and visual outcome of patients with
extended wear contact lens (EWCL) related bacterial keratitis. METHODS: 11 cases
with EWCL related bacterial keratitis were included. Corneal scrapings were
obtained for cytology and cultures. RESULTS: Nine patients had unilateral
bacterial keratitis and two patients showed bilateral involvement. Corneal
scrapings revealed Pseudomonas aeruginosa in seven patients, Staphylococcus
aureus coagulase positive in one patient, and Staphylococcus epidermidis in three
patients. CONCLUSION: EWCLs may be associated with bacterial keratitis and may
result in visual loss. Dispensing contact lenses by optometrists should be
performed in consultation with ophthalmologists.
PMID- 10684848
TI - Lacrimal drainage surgery in Wegener's granulomatosis.
AB - AIM: To examine the results of open lacrimal surgery in patients with Wegener's
granulomatosis. METHODS: A retrospective review of patients with Wegener's
granulomatosis who underwent lacrimal surgery over a 17 year period. RESULTS: 11
patients were identified and a total of 14 primary dacryocystorhinostomies (DCR)
and one revisional DCR were performed; symptomatic relief was achieved in 13/14
operations and one patient required revisional surgery for persistent symptoms.
There were no intraoperative and few postoperative complications. CONCLUSIONS: In
contrast with some previous reports, open DCR appears to be a safe procedure and
it is recommended as a treatment for lacrimal obstruction in patients with
Wegener's granulomatosis, but an increase of perioperative immunosuppression is
recommended in certain cases.
PMID- 10684849
TI - Role of cytokines in the pathogenesis of posterior capsule opacification.
PMID- 10684850
TI - Tyrosine-phosphorylated bacterial proteins: Trojan horses for the host cell.
PMID- 10684851
TI - Helicobacter pylori CagA protein can be tyrosine phosphorylated in gastric
epithelial cells.
AB - Attachment of Helicobacter pylori to gastric epithelial cells induces various
cellular responses, including the tyrosine phosphorylation of an unknown 145-kD
protein and interleukin 8 production. Here we show that this 145-kD protein is
the cagA product of H. pylori, an immunodominant, cytotoxin-associated antigen.
Epithelial cells infected with various H. pylori clinical isolates resulted in
generation of tyrosine-phosphorylated proteins ranging from 130 to 145 kD in size
that were also induced in vitro by mixing host cell lysate with bacterial lysate.
When epithelial cells were infected with [(35)S]methionine-labeled H. pylori, a
radioactive 145-kD protein was detected in the immunoprecipitates with
antiphosphotyrosine antibody or anti-CagA (cytotoxin-associated gene A) antibody.
Consistently, the 145-kD protein recognized by the anti-CagA and
antiphosphotyrosine antibodies was induced in epithelial cells after infection of
wild-type H. pylori but not the cagA::Km mutant. Furthermore, the amino acid
sequence of the phosphorylated 145-kD protein induced by H. pylori infection was
identical to the H. pylori CagA sequence. These results reveal that the tyrosine
phosphorylated 145-kD protein is H. pylori CagA protein, which may be delivered
from attached bacteria into the host cytoplasm. The identification of the
tyrosine-phosphorylated protein will thus provide further insights into
understanding the precise roles of CagA protein in H. pylori pathogenesis.
PMID- 10684852
TI - The intestinal T cell response to alpha-gliadin in adult celiac disease is
focused on a single deamidated glutamine targeted by tissue transglutaminase.
AB - The great majority of patients that are intolerant of wheat gluten protein due to
celiac disease (CD) are human histocompatibility leukocyte antigen (HLA)-DQ2(+),
and the remaining few normally express HLA-DQ8. These two class II molecules are
chiefly responsible for the presentation of gluten peptides to the gluten
specific T cells that are found only in the gut of CD patients but not of
controls. Interestingly, tissue transglutaminase (tTG)-mediated deamidation of
gliadin plays an important role in recognition of this food antigen by intestinal
T cells. Here we have used recombinant antigens to demonstrate that the
intestinal T cell response to alpha-gliadin in adult CD is focused on two
immunodominant, DQ2-restricted peptides that overlap by a seven-residue fragment
of gliadin. We show that tTG converts a glutamine residue within this fragment
into glutamic acid and that this process is critical for T cell recognition.
Gluten-specific T cell lines from 16 different adult patients all responded to
one or both of these deamidated peptides, indicating that these epitopes are
highly relevant to disease pathology. Binding studies showed that the deamidated
peptides displayed an increased affinity for DQ2, a molecule known to
preferentially bind peptides containing negatively charged residues.
Interestingly, the modified glutamine is accommodated in different pockets of DQ2
for the different epitopes. These results suggest modifications of anchor
residues that lead to an improved affinity for major histocompatibility complex
(MHC), and altered conformation of the peptide-MHC complex may be a critical
factor leading to T cell responses to gliadin and the oral intolerance of gluten
found in CD.
PMID- 10684853
TI - Salmonella-induced apoptosis of infected macrophages results in presentation of a
bacteria-encoded antigen after uptake by bystander dendritic cells.
AB - Salmonella typhimurium is a gram-negative bacterium that survives and replicates
inside vacuolar compartments of macrophages. Infection of macrophages with S.
typhimurium grown under conditions allowing expression of the type III secretion
system results in apoptotic death of the infected cells. Here, we show that
infection of bone marrow-derived macrophages (MPhi) with wild-type S. typhimurium
14028 results in presentation of epitopes derived from a bacteria-encoded antigen
on major histocompatibility complex (MHC) class I and MHC class II molecules
after internalization of apoptotic MPhi by bystander dendritic cells (DCs). In
contrast, infection of MPhi with the phoP constitutive mutant strain CS022, which
does not induce apoptosis in infected MPhi, does not result in presentation of a
bacteria-derived antigen by bystander DCs unless the infected MPhi are induced to
undergo apoptosis by treatment with lipopolysaccharide and ATP. DCs appear to be
unique in their ability to present antigens derived from MPhi induced to undergo
apoptosis by Salmonella, as bystander MPhi are not capable of presenting the
bacteria-derived antigen despite the fact that they efficiently internalize the
apoptotic cells. These data suggest that apoptosis induction by bacterial
infection of MPhi may not be a quiescent death that allows the bacteria to escape
recognition by the immune system, but rather may contribute to an antimicrobial
immune response upon engulfment by bystander DCs.
PMID- 10684854
TI - Identification of NY-ESO-1 epitopes presented by human histocompatibility antigen
(HLA)-DRB4*0101-0103 and recognized by CD4(+) T lymphocytes of patients with NY
ESO-1-expressing melanoma.
AB - NY-ESO-1 is a member of the cancer-testis family of tumor antigens that elicits
strong humoral and cellular immune responses in patients with NY-ESO-1-expressing
cancers. Since CD4(+) T lymphocytes play a critical role in generating antigen
specific cytotoxic T lymphocyte and antibody responses, we searched for NY-ESO-1
epitopes presented by histocompatibility leukocyte antigen (HLA) class II
molecules. Autologous monocyte-derived dendritic cells of cancer patients were
incubated with recombinant NY-ESO-1 protein and used in enzyme-linked immunospot
(ELISPOT) assays to detect NY-ESO-1-specific CD4(+) T lymphocyte responses. To
identify possible epitopes presented by distinct HLA class II alleles,
overlapping 18-mer peptides derived from NY-ESO-1 were synthetized and tested for
recognition by CD4(+) T lymphocytes in autologous settings. We identified three
NY-ESO-1-derived peptides presented by DRB4*0101-0103 and recognized by CD4(+) T
lymphocytes of two melanoma patients sharing these HLA class II alleles.
Specificity of recognition was confirmed by proliferation assays. The
characterization of HLA class II-restricted epitopes will be useful for the
assessment of spontaneous and vaccine-induced immune responses of cancer patients
against defined tumor antigens. Further, the therapeutic efficacy of active
immunization using antigenic HLA class I-restricted peptides may be improved by
adding HLA class II-presented epitopes.
PMID- 10684855
TI - Promyelocytic leukemia protein (PML) and Daxx participate in a novel nuclear
pathway for apoptosis.
AB - The promyelocytic leukemia protein (PML) gene of acute promyelocytic leukemia
(APL) encodes a cell growth and tumor suppressor essential for multiple apoptotic
signals. Daxx was identified as a molecule important for the cytoplasmic
transduction of the Fas proapoptotic stimulus. Here, we show that upon mitogenic
activation of mature splenic lymphocytes, Daxx is dramatically upregulated and
accumulates in the PML nuclear body (NB) where PML and Daxx physically interact.
In the absence of PML, Daxx acquires a dispersed nuclear pattern, and activation
induced cell death of splenocytes is profoundly impaired. PML inactivation
results in the complete abrogation of the Daxx proapoptotic ability. In APL
cells, Daxx is delocalized from the NB. Upon retinoic acid treatment, which
induces disease remission in APL, Daxx relocalizes to the PML NBs. These results
indicate that PML and Daxx cooperate in a novel NB-dependent pathway for
apoptosis and shed new light in the role of PML in tumor suppression.
PMID- 10684856
TI - Cbl suppresses B cell receptor-mediated phospholipase C (PLC)-gamma2 activation
by regulating B cell linker protein-PLC-gamma2 binding.
AB - Accumulating evidence indicates that the Cbl protein plays a negative role in
immune receptor signaling; however, the mode of Cbl action in B cell receptor
(BCR) signaling still remains unclear. DT40 B cells deficient in Cbl showed
enhanced BCR-mediated phospholipase C (PLC)-gamma2 activation, thereby leading to
increased apoptosis. A possible explanation for the involvement of Cbl in PLC
gamma2 activation was provided by findings that Cbl interacts via its Src
homology 2 (SH2) domain with B cell linker protein (BLNK) after BCR ligation.
BLNK is a critical adaptor molecule for PLC-gamma2 tyrosine phosphorylation
through its binding to the PLC-gamma2 SH2 domains. As a consequence of the
interaction between Cbl and BLNK, the BCR-induced recruitment of PLC-gamma2 to
BLNK and the subsequent PLC-gamma2 tyrosine phosphorylation were inhibited. Thus,
our data suggest that Cbl negatively regulates the PLC-gamma2 pathway by
inhibiting the association of PLC-gamma2 with BLNK.
PMID- 10684857
TI - CD40 ligand (CD154) triggers a short-term CD4(+) T cell activation response that
results in secretion of immunomodulatory cytokines and apoptosis.
AB - Signals generated through CD28-B7 and CD40 ligand (CD40L)-CD40 interactions have
been shown to be crucial for the induction of long-term allograft survivability.
We have recently demonstrated that humanized anti-CD40L (hu5C8) prevents
rejection of mismatched renal allografts in primates. To investigate potential
mechanisms of CD40L-induced allograft acceptance, we coimmobilized hu5C8 with
suboptimal amounts of anti-CD3 to stimulate CD4(+) T cells. We now report that
anti-CD3/CD40L costimulation results in CD28-independent activation and
subsequent deletion of resting T cells. Coligation of CD3 and CD40L increased
expression of CD69, CD25, and CD54 on CD4(+) T cells. We also found that
costimulation with anti-CD3/CD40L resulted in enhanced production of interleukin
(IL)-10, interferon gamma, and tumor necrosis factor alpha but not IL-2 or IL-6.
Interestingly, after several days, anti-CD3/CD40L-mediated activation was
followed by apoptosis in a significant population of cells. Consistent with that
observation, anti-CD3/CD40L did not enhance the antiapoptotic proteins Bcl-2 and
Bcl-xL. Further, the addition of CD28 at 24 h failed to rescue those cells
induced to die after costimulation with anti-CD3/CD40L. Together, these data
suggest that the graft-sparing effect of hu5C8 in vivo may result in part from
early and direct effects on CD4(+) T cells, including a vigorous induction of
immunomodulatory cytokines and/or apoptosis of allograft-specific T cells.
PMID- 10684858
TI - Differential tumor surveillance by natural killer (NK) and NKT cells.
AB - Natural tumor surveillance capabilities of the host were investigated in six
different mouse tumor models where endogenous interleukin (IL)-12 does or does
not dictate the efficiency of the innate immune response. Gene-targeted and
lymphocyte subset-depleted mice were used to establish the relative importance of
natural killer (NK) and NK1.1(+) T (NKT) cells in protection from tumor
initiation and metastasis. In the models examined, CD3(-) NK cells were
responsible for tumor rejection and protection from metastasis in models where
control of major histocompatibility complex class I-deficient tumors was
independent of IL-12. A protective role for NKT cells was only observed when
tumor rejection required endogenous IL-12 activity. In particular, T cell
receptor Jalpha281 gene-targeted mice confirmed a critical function for NKT cells
in protection from spontaneous tumors initiated by the chemical carcinogen,
methylcholanthrene. This is the first description of an antitumor function for
NKT cells in the absence of exogenously administered potent stimulators such as
IL-12 or alpha-galactosylceramide.
PMID- 10684859
TI - Fcgamma receptor-mediated phagocytosis in macrophages lacking the Src family
tyrosine kinases Hck, Fgr, and Lyn.
AB - Macrophage Fcgamma receptors (FcgammaRs) mediate the uptake and destruction of
antibody-coated viruses, bacteria, and parasites. We examined FcgammaR signaling
and phagocytic function in bone marrow-derived macrophages from mutant mice
lacking the major Src family kinases expressed in these cells, Hck, Fgr, and Lyn.
Many FcgammaR-induced functional responses and signaling events were diminished
or delayed in these macrophages, including immunoglobulin (Ig)G-coated
erythrocyte phagocytosis, respiratory burst, actin cup formation, and activation
of Syk, phosphatidylinositol 3-kinase, and extracellular signal-regulated kinases
1 and 2. Significant reduction of IgG-dependent phagocytosis was not seen in hck(
)(/)-fgr(-)(/)- or lyn(-)(/)- cells, although the single mutant lyn(-)(/)-
macrophages did manifest signaling defects. Thus, Src family kinases clearly have
roles in two events leading to FcgammaR-mediated phagocytosis, one involving
initiation of actin polymerization and the second involving activation of Syk and
subsequent internalization. Since FcgammaR-mediated phagocytosis did occur at
modest levels in a delayed fashion in triple mutant macrophages, these Src family
kinases are not absolutely required for uptake of IgG-opsonized particles.
PMID- 10684860
TI - Interleukin 4-producing CD4 T cells arise from different precursors depending on
the conditions of antigen exposure in vivo.
AB - The precursor origin of T helper (Th) cell subsets in vivo has been difficult to
study and remains poorly investigated. We have previously shown that chronic
administration of soluble protein antigen induces selective development of
antigen-specific CD4 Th2 cells in genetically predisposed mouse strains. To
analyze the origin of effector T cells in this model, we designed a competitive
polymerase chain reaction-based approach to track public BV-J rearrangement
expressed by CD4 T cells specific for hen egg white lysozyme (HEL) in BALB/c
mice. We show that public T cell clones are predominantly associated with type 1
or 2 effector Th cells recovered after primary immunization in complete or
incomplete Freund's adjuvant, respectively. Conversely, continuous administration
of soluble antigen, which induces strong memory Th2 response, is associated with
a dose-dependent reduction of public clone size by a mechanism resembling clonal
anergy. Thus, soluble HEL-induced Th2 cells do not express the public
complementarity determining region 3 motifs characteristic of immunogenic
challenge in the presence of adjuvant. These results demonstrate that there are
multiple pathways of induction of Th2 responses depending on the condition of
antigen exposure in vivo, i.e., clonal immune deviation versus recruitment of a
different pool of precursor cells.
PMID- 10684861
TI - T cell receptor complementarity determining region 3 length analysis reveals the
absence of a characteristic public T cell repertoire in neonatal tolerance. The
response in the "tolerant" mouse within the residual repertoire is quantitatively
similar but qualitatively different.
AB - All adult BALB/c mice immunized with hen egg white lysozyme (HEL) or its dominant
determinant, peptide (p)106-116, mount a T cell response using a "public"
Vbeta8.2Jbeta1.5 T cell clone. Neonatal exposure to tolerance-inducing doses of
antigen can drastically diminish responsiveness in the draining lymph nodes but
not in the spleens of animals challenged as adults with the cognate antigen. To
determine the role of T cell deletion or anergy within the mechanisms of observed
neonatal "tolerance," we treated neonatal BALB/c mice with HEL and directly
followed the characteristic public clone using complementarity determining region
3 length T cell repertoire analysis. Our results confirm that despite
intraperitoneal injection of neonates with a high dose of HEL emulsified in
incomplete Freund's adjuvant, a strong splenic proliferative response to HEL was
observed upon recall. However, the adult splenic T cell response of these
neonatally treated mice lacked the usual Vbeta8.2Jbeta1.5 public clone
characteristic of HEL-primed BALB/c mice. After challenge with HEL-complete
Freund's adjuvant as adults, immunoglobulin (Ig)G2a isotype antibody was
drastically reduced, and IgG1 was found to be the predominant anti-HEL IgG
isotype expressed, indicating a deviation of cytokine response toward T helper
type 2. 5-wk-old mice, nasally instilled with tolerogenic doses of HEL p106-116,
also showed significant inhibition of this public T cell expansion. These results
demonstrate that during neonatal and adult nasal tolerance induction,
deletion/anergy removes the public clone, exposing a response of similar
specificity but that is characterized by the T helper type 2 phenotype and a
splenic residence.
PMID- 10684862
TI - Lck domains differentially contribute to pre-T cell receptor (TCR)- and TCR
alpha/beta-regulated developmental transitions.
AB - Maturational changes at the CD4(-)CD8(-) double negative (DN) to CD4(+)CD8(+)
double positive (DP) transition are dependent on signals generated via the pre-T
cell receptor (TCR) and the nonreceptor protein tyrosine kinase p56(lck) (Lck).
How Lck activities are stimulated or relayed after pre-TCR formation remains
obscure. Our structure-function mapping of Lck thymopoietic properties reveals
that the noncatalytic domains of Lck are specialized to signal efficient cellular
expansion at DN to DP transition. Moreover, although substitution of the Lck
catalytic domain with FynT sequences minimally impacts DP development, single
positive thymocytes are most efficiently produced in the presence of kinases
containing both the NH(2)-terminal and catalytic regions of Lck. These findings
demonstrate that the Lck structure is uniquely adapted to mediate signals at both
major transitions in thymopoiesis.
PMID- 10684863
TI - Induction and suppression of an autoimmune disease by oligomerized T cell
epitopes: enhanced in vivo potency of encephalitogenic peptides.
AB - T cell epitope peptides derived from proteolipid protein (PLP139-151) or myelin
basic protein (MBP86-100) induce experimental autoimmune encephalomyelitis (EAE)
in "susceptible" strains of mice (e.g., SJL/J). In this study, we show that the
encephalitogenic effect of these epitopes when injected subcutaneously in
complete Freund's adjuvant was significantly enhanced if administered to the
animal in a multimerized form as a T cell epitope oligomer (i.e., as multiple
repeats of the peptide epitope, such as 16-mers). Oligomer-treated SJL/J mice
developed EAE faster and showed a more severe progression of the disease than
animals treated with peptide alone. In addition, haplotype-matched B10.S mice,
"resistant" to EAE induction by peptide, on injection of 16-mers developed a
severe form of EAE. Even more striking, however, was the dramatic suppression of
incidence and severity of the disease, seen after single intravenous injections
of only 50 microg of the PLP139-151 16-mer, administered to SJL/J mice 7 d after
the induction of the disease. Although relapse occurred at about day 45, an
additional injection several days before that maintained the suppression.
Importantly, the specific suppressive effect of oligomer treatment was also
evident if EAE was induced with spinal cord homogenate instead of the single
peptide antigen. By contrast, the PLP139-151 peptide accelerated rather than
retarded the progression of disease.
PMID- 10684864
TI - B1 B lymphocytes play a critical role in host protection against lymphatic
filarial parasites.
AB - Host defense against multicellular, extracellular pathogens such as nematode
parasites is believed to be mediated largely, if not exclusively, by T
lymphocytes. During our investigations into the course of Brugia malayi and
Brugia pahangi infections in immunodeficient mouse models, we found that mice
lacking B lymphocytes were permissive for Brugian infections, whereas
immunocompetent mice were uniformly resistant. Mice bearing the Btk(xid) mutation
were as permissive as those lacking all B cells, suggesting that the B1 subset
may be responsible for host protection. Reconstitution of immunodeficient
recombination activating gene (Rag)-1(-/)- mice with B1 B cells conferred
resistance, even in the absence of conventional B2 lymphocytes and most T cells.
These results suggest that B1 B cells are necessary to mediate host resistance to
Brugian infection. Our data are consistent with a model wherein early resistance
to B. malayi is mediated by humoral immune response, with a significant attrition
of the incoming infectious larval load. Sterile clearance of the remaining
parasite burden appears to require cell-mediated immunity. These data raise the
possibility that the identification of molecule(s) recognized by humoral immune
mechanisms might help generate prophylactic vaccines.
PMID- 10684865
TI - Inhibition of interleukin 7 receptor signaling by antigen receptor assembly.
AB - After the productive rearrangement of immunoglobulin (Ig) heavy chain genes,
precursor (pre-)B lymphocytes undergo a limited number of cell divisions in
response to interleukin (IL)-7. Here, we present evidence that this phase of IL-7
dependent expansion is constrained by an inhibitory signal initiated by antigen
receptor assembly. A line of pre-B cells from normal murine bone marrow that
expresses a mu heavy chain with a D-proximal V(H)7183.2 region divides
continuously in IL-7. IL-7 responsiveness ceases upon differentiation to the
mu(1), kappa(1) stage, despite continuing expression of the IL-7 receptor (IL
7R), suggesting that antigen receptor assembly inhibits IL-7 responsiveness. This
is confirmed by introduction of a rearranged lambda light chain gene, which
inhibits proliferative signaling through the IL-7R. Inhibition is specific to the
IL-7R, because it is overcome by replacement of the IL-7R cytoplasmic domain with
corresponding sequences from the closely related IL-2Rbeta chain. Alteration of a
single tyrosine residue, Tyr410, in the IL-7R cytoplasmic domain to phenylalanine
also prevents the inhibition of proliferation after antigen receptor assembly.
Thus, the loss of IL-7 responsiveness after antigen receptor assembly may be
mediated through the recruitment of an inhibitory molecule to this residue. Our
findings identify a novel mechanism that limits cytokine-dependent proliferation
during B lymphopoiesis. This mechanism may be essential for the proper regulation
of peripheral B lymphocyte numbers.
PMID- 10684866
TI - The role of aquaporins in dendritic cell macropinocytosis.
AB - Immature dendritic cells (DCs) constitutively take up large volumes of fluid by
macropinocytosis and concentrate the macrosolutes in the endocytic compartment.
This concentration mechanism that is the basis of their high capacity to present
soluble antigens requires that DCs be capable of rapidly exchanging water across
their membranes. We report that two members of the aquaporin family, AQP3 and
AQP7, are expressed in immature DCs and are downregulated after maturation.
Treatment of DCs with p-chloromercuribenzenesulphonate (pCMBS), a mercuric drug
that blocks aquaporins, inhibited uptake and concentration of macrosolutes taken
up by fluid phase endocytosis and led to dramatic cell swelling. In contrast,
pCMBS did not affect receptor-mediated endocytosis via the mannose receptor.
These findings indicate that aquaporins represent essential elements of a volume
control mechanism that allows DCs to concentrate macrosolutes taken up via
macropinocytosis.
PMID- 10684867
TI - Neurons regulate extracellular levels of amyloid beta-protein via proteolysis by
insulin-degrading enzyme.
AB - Progressive cerebral accumulation of amyloid beta-protein (Abeta) is an early and
invariant feature of Alzheimer's disease. Little is known about how Abeta, after
being secreted, is degraded and cleared from the extracellular space of the
brain. Defective Abeta degradation could be a risk factor for the development of
Alzheimer's disease in some subjects. We reported previously that microglial
cells release substantial amounts of an Abeta-degrading protease that, after
purification, is indistinguishable from insulin-degrading enzyme (IDE). Here we
searched for and characterized a role for IDE in Abeta degradation by neurons,
the principal cell type that produces Abeta. Whole cultures of differentiated
pheochromocytoma (PC12) cells and primary rat cortical neurons actively degraded
endogenously secreted Abeta via IDE. However, unlike that in microglia, IDE in
differentiated neurons was not released but localized to the cell surface, as
demonstrated by biotinylation. Undifferentiated PC12 cells released IDE into
their medium, whereas after differentiation, IDE was cell associated but still
degraded Abeta in the medium. Overexpression of IDE in mammalian cells markedly
reduced the steady-state levels of extracellular Abeta(40) and Abeta(42), and the
catalytic site mutation (E111Q) abolished this effect. We observed a novel
membrane-associated form of IDE that is approximately 5 kDa larger than the known
cytosolic form in a variety of cells, including differentiated PC12 cells. Our
results support a principal role for membrane-associated and secreted IDE
isoforms in the degradation and clearance of naturally secreted Abeta by neurons
and microglia.
PMID- 10684868
TI - Declines in mRNA expression of different subunits may account for differential
effects of aging on agonist and antagonist binding to the NMDA receptor.
AB - The purpose of the present study was to determine whether some of the age-related
changes that occur in binding to the NMDA receptor complex can be accounted for
by changes in subunit expression during the aging process. In situ hybridization
for the NMDA subunits zeta1, epsilon1, and epsilon2, and receptor
autoradiography, using the agonist glutamate and the competitive antagonist [(+/
)-2-carboxypiperazin-4-yl] propyl-1-phosphonic acid (CPP), were performed on
sections from C57Bl/6 mice representing three different age groups (3, 10, and 30
months of age). There was a significant overall decrease between 3 and 30 month
olds in the density of mRNA for the zeta1 subunit in the cortex and hippocampus,
but only a few individual brain regions exhibited significant declines. The mRNA
for the epsilon2 subunit was significantly decreased in a majority of cortical
regions and in the dentate granule cells. Emulsion analysis indicated that the
change in the density of epsilon2 subunit mRNA in the inner frontal cortex was
primarily attributable to a decrease in the amount of messages per cell. Age
related changes in mRNA density of the epsilon2 subunit correlated with changes
in NMDA-displaceable [(3)H]glutamate binding, and mRNA density changes in the
zeta1 subunit showed a significant relationship with changes in [(3)H]CPP binding
in the 30-month-old mice. These results suggest that changes during aging in the
expression of different subunits of the NMDA receptor may account for the
differential effects of aging on agonist versus antagonist binding to the NMDA
binding site.
PMID- 10684869
TI - beta subunits modulate alternatively spliced, large conductance, calcium
activated potassium channels of avian hair cells.
AB - Electrical tuning confers frequency selectivity onto sensory hair cells in the
auditory periphery of frogs, turtles, and chicks. The resonant frequency is
determined in large part by the number and kinetics of large conductance, calcium
activated potassium (BK) channels. BK channels in hair cells are encoded by the
alternatively spliced slo gene and may include an accessory beta subunit. Here we
examine the origins of kinetic variability among BK channels by heterologous
expression of avian cochlear slo cDNAs. Four alternatively spliced forms of the
slo-alpha gene from chick hair cells were co-expressed with accessory beta
subunits (from quail cochlea) by transient transfection of human embryonic kidney
293 cells. Addition of the beta subunit increased steady-state calcium affinity,
raised the Hill coefficient for calcium binding, and slowed channel deactivation
rates, resulting in eight functionally distinct channels. For example, a
naturally occurring splice variant containing three additional exons deactivated
20-fold more slowly when combined with beta. Deactivation kinetics were used to
predict tuning frequencies and thus tonotopic location if hair cells were endowed
with each of the expressed channels. All beta-containing channels were predicted
to lie within the apical (low-frequency) 30% of the epithelium, consistent with
previous in situ hybridization studies. Individual slo-alpha exons would be found
anywhere within the apical 70%, depending on the presence of beta, and other
alternative exons. Alternative splicing of the slo-alpha channel message provides
intrinsic variability in gating kinetics that is expanded to a wider range of
tuning by modulation with beta subunits.
PMID- 10684870
TI - Coexpression of cloned alpha(1B), beta(2a), and alpha(2)/delta subunits produces
non-inactivating calcium currents similar to those found in bovine chromaffin
cells.
AB - Chromaffin cells express N-type calcium channels identified on the basis of their
high sensitivity to block by omega-conotoxin GVIA (omega-CgTx GVIA). In contrast
to neuronal N-type calcium currents that inactivate during long depolarizations
and that require negative holding potentials to remove inactivation, many
chromaffin cells exhibit N-type calcium channel currents that show little
inactivation during maintained depolarizations and that exhibit no decrease in
channel availability at depolarized holding potentials. N-type calcium channels
are thought to be produced by combination of the pore-forming alpha(1B) subunit
and accessory beta and alpha(2)/delta subunits. To examine the molecular
composition of the non-inactivating N-type calcium channel, we cloned the
alpha(1B) and accessory beta (beta(1b), beta(1c,) beta(2a), beta(2b), and
beta(3a)) subunits found in bovine chromaffin cells. Expression of the subunits
in either Xenopus oocytes or human embryonic kidney 293 cells produced high
threshold calcium currents that were blocked by omega-CgTx GVIA. Coexpression of
bovine alpha(1B) with beta(1b), beta(1c), beta(2b), or beta(3a) produced currents
that were holding potential dependent. In contrast, coexpression of bovine
alpha(1B) with beta(2a) produced holding potential-independent calcium currents
that closely mimicked native non-inactivating currents, suggesting that non
inactivating N-type channels consist of bovine alpha(1B), alpha(2)/delta, and
beta(2a).
PMID- 10684871
TI - Estrogen-induced activation of the mitogen-activated protein kinase cascade in
the cerebral cortex of estrogen receptor-alpha knock-out mice.
AB - We have shown previously in the developing cerebral cortex that estrogen elicits
the rapid and sustained activation of multiple signaling proteins within the
mitogen-activated protein (MAP) kinase cascade, including B-Raf and extracellular
signal-regulated kinase (ERK). Using estrogen receptor (ER)-alpha gene-disrupted
(ERKO) mice, we addressed the role of ER-alpha in mediating this action of
estrogen in the brain. 17beta-Estradiol increased B-Raf activity and MEK (MAP
kinase/ERK kinase)-dependent ERK phosphorylation in cerebral cortical explants
derived from both ERKO and their wild-type littermates. The ERK response was
stronger in ERKO-derived cultures but, unlike that of wild-type cultures, was not
blocked by the estrogen receptor antagonist ICI 182,780. Surprisingly, both the
ER-alpha selective ligand 16alpha-iodo-17beta-estradiol and the ER-beta selective
ligand genistein failed to elicit ERK phosphorylation, suggesting that a
different mechanism or receptor may mediate estrogen-induced ERK phosphorylation
in the cerebral cortex. Interestingly, the transcriptionally inactive
stereoisomer 17alpha-estradiol did elicit a strong induction of ERK
phosphorylation, which, together with the inability of the ER-alpha- and ER-beta
selective ligands to elicit ERK phosphorylation, and of ICI 182,780 to block the
actions of estradiol in ERKO cultures, supports the hypothesis that a novel,
estradiol-sensitive and ICI-insensitive estrogen receptor may mediate 17beta
estradiol-induced activation of ERK in the brain.
PMID- 10684872
TI - Calcium transients in the rhabdomeres of dark- and light-adapted fly
photoreceptor cells.
AB - The light response of fly photoreceptor cells is modulated by changes in free
Ca(2+) concentration. Fly phototransduction and most processes regulating it take
place in or very close to the rhabdomere. We therefore measured the kinetics and
the absolute values of the free Ca(2+) concentration in the rhabdomere of fly
photoreceptor cells in vivo by making use of the natural optics of the fly's eye.
We show that Ca(2+) flowing into the rhabdomere after light stimulation of dark
adapted cells causes fast Ca(2+) transients that reach peak values higher than
200 microM in <20 msec. Approximately 500 msec later, the free Ca(2+)
concentration has declined again to approximately 20 microM. The duration of the
Ca(2+) transients becomes still shorter, and their size reduced, when the
photoreceptor cell is light-adapted. This reduction in duration and size of the
Ca(2+) transients is graded with the intensity of the adapting light. The
kinetics and absolute values of the free calcium concentration found to occur in
the rhabdomere are suitable to mediate the fast feedback signals known to act on
the fly phototransduction cascade.
PMID- 10684873
TI - Reconstitution of muscarinic modulation of the KCNQ2/KCNQ3 K(+) channels that
underlie the neuronal M current.
AB - Channels from KCNQ2 and KCNQ3 genes have been suggested to underlie the neuronal
M-type K(+) current. The M current is modulated by muscarinic agonists via G
proteins and an unidentified diffusible cytoplasmic messenger. Using whole-cell
clamp, we studied tsA-201 cells in which cloned KCNQ2/KCNQ3 channels were
coexpressed with M(1) muscarinic receptors. Heteromeric KCNQ2/KCNQ3 currents were
modulated by the muscarinic agonist oxotremorine-M (oxo-M) in a manner having all
of the characteristics of modulation of native M current in sympathetic neurons.
Oxo-M also produced obvious intracellular Ca(2+) transients, observed by using
indo-1 fluorescence. However, modulation of the current remained strong even when
Ca(2+) signals were abolished by the combined use of strong intracellular Ca(2+)
buffers, an inhibitor of IP(3) receptors, and thapsigargin to deplete Ca(2+)
stores. Muscarinic modulation was not blocked by staurosporine, a broad-spectrum
protein kinase inhibitor, arguing against involvement of protein kinases. The
modulation was not associated with a shift in the voltage dependence of channel
activation. Homomeric KCNQ2 and KCNQ3 channels also expressed well and were
modulated individually by oxo-M, suggesting that the motifs for modulation are
present on both channel subtypes. Homomeric KCNQ2 and KCNQ3 currents were
blocked, respectively, at very low and at high concentrations of
tetraethylammonium ion. Finally, when KCNQ2 subunits were overexpressed by
intranuclear DNA injection in sympathetic neurons, total M current was fully
modulated by the endogenous neuronal muscarinic signaling mechanism. Our data
further rule out Ca(2+) as the diffusible messenger. The reconstitution of
muscarinic modulation of the M current that uses cloned components should
facilitate the elucidation of the muscarinic signaling mechanism.
PMID- 10684874
TI - Mechanisms of calcium decay kinetics in hippocampal spines: role of spine calcium
pumps and calcium diffusion through the spine neck in biochemical
compartmentalization.
AB - Dendritic spines receive most excitatory inputs in the CNS and compartmentalize
calcium. Although the mechanisms of calcium influx into spines have been
explored, it is unknown what determines the calcium decay kinetics in spines.
With two-photon microscopy we investigate action potential-induced calcium
dynamics in spines from rat CA1 pyramidal neurons in slices. The [Ca(2+)](i) in
most spines shows two decay kinetics: an initial fast component, during which
[Ca(2+)](i) in spines decays to dendritic levels, followed by a slower decay
phase in which the spine follows dendritic kinetics. The correlation between
[Ca(2+)](i) in spine and dendrite at the breakpoint of the decay kinetics
demonstrates diffusional equilibration between spine and dendrite during the
slower component. To explain the faster initial decay, we rule out saturation or
kinetic effects of endogenous or exogenous buffers and focus instead on (1)
active calcium extrusion and (2) buffered diffusion of calcium from spine to
dendrite. The presence of an undershoot in most spines indicates that extrusion
mechanisms can be intrinsic to the spine. Supporting the two mechanisms,
pharmacological blockade of smooth endoplasmic reticulum calcium (SERCA) pumps
and the length of the spine neck affect spine decay kinetics. Using a
mathematical model, we find that the contribution of calcium pumps and diffusion
varies from spine to spine. We conclude that dendritic spines have calcium pumps
and that their density and kinetics, together with the morphology of the spine
neck, determine the time during which the spine compartmentalizes calcium.
PMID- 10684875
TI - Reciprocal inhibitory connections regulate the spatiotemporal properties of
intrathalamic oscillations.
AB - Mice with an inactivated GABA(A) receptor beta(3) subunit gene have features of
Angelman syndrome, including absence-like seizures. This suggests the occurrence
of abnormal hypersynchrony in the thalamocortical system. Within the thalamus,
the efficacy of inhibitory synapses between thalamic reticular (RE) neurons is
selectively compromised, and thalamic oscillations in vitro are prolonged and
lack spatial phase gradients (). Here we used computational models to examine how
intra-RE inhibition regulates intrathalamic oscillations. A major effect is an
abbreviation of network responses, which is caused by long-lasting intra-RE
inhibition that shunts recurrent excitatory input. In addition, differential
activation of RE cells desynchronizes network activity. Near the slice center,
where many cells are initially activated, there is a resultant high level of
intra-RE inhibition. This leads to RE cell burst truncation in the central region
and a gradient in the timing of thalamocortical cell activity similar to that
observed in vitro. Although RE cell burst durations were shortened by this
mechanism, there was very little effect on the times at which RE cells began to
burst. The above results depended on widespread stimuli that activated RE cells
in regions larger than the diameter of intra-RE connections. By contrast, more
focal stimuli could elicit oscillations that lasted several cycles and remained
confined to a small region. These results suggest that intra-RE inhibition
restricts intrathalamic activity to particular spatiotemporal patterns to allow
focal recurrent activity that may be relevant for normal thalamocortical function
while preventing widespread synchronization as occurs in seizures.
PMID- 10684876
TI - dCLOCK is present in limiting amounts and likely mediates daily interactions
between the dCLOCK-CYC transcription factor and the PER-TIM complex.
AB - In Drosophila melanogaster four circadian clock proteins termed PERIOD (PER),
TIMELESS (TIM), dCLOCK (dCLK), and CYCLE (CYC/dBMAL1) function in a
transcriptional feedback loop that is a core element of the oscillator mechanism.
dCLK and CYC are members of the basic helix-loop-helix (bHLH)/PAS (PER-ARNT-SIM)
superfamily of transcription factors and are required for high-level expression
of per and tim and repression of dClk, whereas PER and TIM inhibit dCLK-CYC
mediated transcription and lead to the activation of dClk. To understand further
the dynamic regulation within the circadian oscillator mechanism, we
biochemically characterized in vivo-produced CYC, determined the interactions of
the four clock proteins, and calculated their absolute levels as a function of
time. Our results indicate that throughout a daily cycle the majority of the dCLK
present in adult heads stably interacts with CYC, indicating that CYC is the
primary in vivo partner of dCLK. dCLK-CYC dimers are bound by PER and TIM during
the late evening and early morning, suggesting the formation of a tetrameric
complex with impaired transcriptional activity. Although dCLK is present in
limiting amounts and CYC is by far the most abundant of the four clock proteins
that have been examined, PER and TIM appear to interact preferentially with dCLK.
Our results suggest that dCLK is the main component regulating the daily
abundance of transcriptionally active dCLK-CYC complexes.
PMID- 10684877
TI - Activity and calcium-dependent mechanisms maintain reliable interneuron synaptic
transmission in a rhythmic neural network.
AB - Inputs from glutamatergic excitatory interneurons (EIN) to motor neurons in the
lamprey spinal cord locomotor network exhibit activity-dependent depression
during spike trains. The mechanism underlying this depression has been examined
here, and its relevance to transmitter release during rhythmic activity has been
investigated. The depression of EIN inputs was greater after larger initial EPSPs
and reduced in low-calcium Ringer's solution, effects that are consistent with
depression caused by depletion of releasable transmitter stores. However, the
depression was greater at lower stimulation frequencies and could be reversed by
increasing the stimulation frequency. In addition, high-calcium Ringer's solution
and the slow intracellular calcium chelator EGTA-AM, which both failed to affect
the amplitude of low frequency-evoked EPSPs, reduced and increased the
depression, respectively. These results are inconsistent with a simple depletion
mechanism but suggest that ongoing activity and calcium-dependent mechanisms
oppose depletion. The network relevance of this mechanism was examined using
physiologically relevant bursts to simulate EIN spiking during rhythmic activity.
Although considerably more EPSPs were evoked than during spike trains, burst
evoked EPSPs did not depress. However, single EPSPs evoked at the interburst
interval depressed, and burst transmission was disrupted by EGTA-AM, again
suggesting the involvement of activity and calcium-dependent mechanisms. By
responding to the calcium changes evoked by increased interneuron activity, this
mechanism can monitor transmitter requirements caused by EIN spiking, allowing
reliable transmission across different patterns of network activity. However, not
all types of spinal interneurons exhibit reliable burst transmission, suggesting
specificity of this mechanism to a subset of neurons.
PMID- 10684878
TI - A fundamental role for the nitric oxide-G-kinase signaling pathway in mediating
intercellular Ca(2+) waves in glia.
AB - In this study, we highlight a role for the nitric oxide-cGMP-dependent protein
kinase (NO-G-kinase) signaling pathway in glial intercellular Ca(2+) wave
initiation and propagation. Addition of the NO donor molsidomine (100-500 microM)
or puffing aqueous NO onto primary glial cell cultures evoked an increase in
[Ca(2+)](i) in individual cells and also local intercellular Ca(2+) waves, which
persisted after removal of extracellular Ca(2+). High concentrations of ryanodine
(100-200 microM) and antagonists of the NO-G-kinase signaling pathway essentially
abrogated the NO-induced increase in [Ca(2+)](i), indicating that NO mobilizes
Ca(2+) from a ryanodine receptor-linked store, via the NO-G-kinase signaling
pathway. Addition of 10 microM nicardipine to cells resulted in a slowing of the
molsidomine-induced rise in [Ca(2+)](i), and inhibition of Mn(2+) quench of
cytosolic fura-2 fluorescence mediated by a bolus application of 2 microM aqueous
NO to cells, indicating that NO also induces Ca(2+) influx in glia. Mechanical
stress of individual glial cells resulted in an increase in intracellular NO in
target and neighboring cells and intercellular Ca(2+) waves, which were NO, cGMP,
and G-kinase dependent, because incubating cells with nitric oxide synthase,
guanylate cyclase, and G-kinase inhibitors, or NO scavengers, reduced
Delta[Ca(2+)](i) and the rate of Ca(2+) wave propagation in these cultures.
Results from this study suggest that NO-G-kinase signaling is coupled to Ca(2+)
mobilization and influx in glial cells and that this pathway plays a fundamental
role in the generation and propagation of intercellular Ca(2+) waves in glia.
PMID- 10684879
TI - Tachykinin-related peptide and GABA-mediated presynaptic inhibition of crayfish
photoreceptors.
AB - Off-axis illumination elicits lateral inhibition at the primary visual synapse in
crustacea and insects. The evidence suggests that the inhibitory action is
presynaptic (i.e., on the photoreceptor terminal) and that the amacrine neurons
of the lamina ganglionaris (the first synaptic layer) may be part of the
inhibitory pathway. The neurotransmitters and the synaptic mechanisms are
unknown. We show by immunocytochemistry that GABA and a tachykinin-related
peptide (TRP) are localized in the amacrine neurons of the crayfish lamina
ganglionaris. Indirect evidence suggests that GABA and TRP may be colocalized in
these neurons. The extensive processes of the amacrine neurons occupy lamina
layers containing the terminals of photoreceptors. Application of exogenous GABA
and TRP to photoreceptor terminals produces a short-latency, dose-dependent
hyperpolarization with a decay time constant on the order of a few seconds. TRP
also exhibits actions that evolve over several minutes. These include a reduction
of the receptor potential (and the light-elicited current) by approximately 40%
and potentiation of the action of GABA by approximately 100%. The mechanisms of
TRP action in crayfish are not known, but a plausible pathway is a TRP-dependent
elevation of intracellular Ca(2+) that reduces photoreceptor sensitivity in
arthropods. Although the mechanisms are not established, the results indicate
that in crayfish photoreceptors TRP displays actions on two time scales and can
exert profound modulatory control over cell function.
PMID- 10684880
TI - NMDA receptor-mediated subthreshold Ca(2+) signals in spines of hippocampal
neurons.
AB - We have used rapid confocal microscopy to investigate the mechanism of Ca(2+)
signals in individual dendritic spines of hippocampal CA1 pyramidal cells. The
experiments focused on the signals that occur during single weak synaptic
responses that were subthreshold for triggering postsynaptic action potentials.
These Ca(2+) signals were not strongly affected by blocking the EPSPs with the
AMPA receptor antagonist CNQX. The signals were also not strongly reduced by
blocking T-type voltage-gated Ca(2+) channels (VGCCs) with Ni(2+) or by blocking
a broad range of VGCCs with intracellular D890. The spine Ca(2+) signals were
blocked by NMDA receptor channel (NMDAR) antagonist and had the voltage
dependence characteristic of these channels. Neither ryanodine nor cyclopiazonic
acid (CPA), substances known to deplete intracellular Ca(2+) stores,
substantially reduced the amplitude of synaptically evoked Ca(2+) signals. CPA
slowed the recovery phase of Ca(2+) signals in spines produced by synaptic
stimulation or by backpropagating action potentials, suggesting a role of
intracellular stores in Ca(2+) reuptake. Thus, we find that Ca(2+) release from
intracellular stores is not required to produce spine Ca(2+) signals. We conclude
that synaptic Ca(2+) signals in spines are primarily caused by Ca(2+) entry
through NMDARs. Although these channels are largely blocked by Mg(2+) at voltages
near the resting potential, they can nevertheless produce significant Ca(2+)
elevation. The resulting Ca(2+) signals are an integral component of individual
evoked or spontaneous synaptic events and may be important in the maintenance of
synaptic function.
PMID- 10684881
TI - Imaging extracellular waves of glutamate during calcium signaling in cultured
astrocytes.
AB - A growing body of evidence proposes that glial cells have the potential to play a
role as modulators of neuronal activity and synaptic transmission by releasing
the neurotransmitter glutamate (Arague et al., 1999). We explore the spatial
nature of glutamate release from astrocytes with an enzyme-linked assay system
and CCD imaging technology. In the presence of glutamate, L-glutamic
dehydrogenase (GDH) reduces NAD(+) to NADH, a product that fluoresces when
excited with UV light. Theoretically, provided that GDH and NAD(+) are present in
the bathing saline, the release of glutamate from stimulated astrocytes can be
optically detected by monitoring the accumulation of NADH. Indeed, stimuli that
induce a wave of elevated calcium among astrocytes produced a corresponding
spread of extracellular NADH fluorescence. Treatment of cultures either with
thapsigargin, to deplete internal calcium stores, or with the membrane-permeant
calcium chelator BAPTA AM significantly decreased the accumulation of NADH,
demonstrating that this fluorometric assay effectively monitors calcium-dependent
glutamate release. With a temporal resolution of 500 msec and spatial resolution
of approximately 20 micrometer, discrete regions of glutamate release were not
reliably resolved. The wave of glutamate release that underlies the NADH
fluorescence propagated at an average speed of approximately 26 micrometer/sec,
correlating with the rate of calcium wave progression (10-30 micrometer/sec), and
caused a localized accumulation of glutamate in the range of 1-100 microM.
Further analysis of the fluorescence accumulation clearly demonstrated that
glutamate is released in a regenerative manner, with subsequent cells that are
involved in the calcium wave releasing additional glutamate.
PMID- 10684882
TI - Mechanisms of glutamate metabolic signaling in retinal glial (Muller) cells.
AB - Retinal Muller (glial) cells metabolize glucose to lactate, which is
preferentially taken up by photoreceptor neurons as fuel for their oxidative
metabolism. We explored whether lactate supply to neurons is a glial function
controlled by neuronal signals. For this, we used subcellular fluorescence
imaging and either amperometric or optical biosensors to monitor metabolic
responses simultaneously from mitochondrial and cytosolic compartments of
individual Muller cells from salamander retina. Our results demonstrate that
lactate production and release is controlled by the combined action of glutamate
and NH(4)(+), both at micromolar concentrations. Transport of glutamate by a high
affinity carrier can produce in Muller cells a rapid rise of glutamate
concentration. In our isolated Muller cells, glutamine synthetase (GS) converted
transported glutamate to glutamine that was released. This reaction, predominant
when enough NH(4)(+) is available, was limited at micromolar concentrations of
NH(4)(+), and more glutamate entered then as substrate into the mitochondrial
tricarboxylic acid cycle (TCA). Increased production of glutamine by GS leads to
increased utilization of ATP, some of which is generated glycolytically.
Methionine sulfoximine, a specific inhibitor of GS, suppressed the stimulatory
effect of glutamate and NH(4)(+) on glycolysis and induced massive entry of
glutamate into the TCA cycle. The rate of glutamine production also determined
the amount of pyruvate transaminated by glutamate to alanine. Lactate, alanine,
and glutamine can be taken up and metabolized by photoreceptor neurons. We
conclude that a major function of Muller glial cells is to nourish retinal
neurons and to metabolize the neurotoxic ammonia and glutamate.
PMID- 10684883
TI - Impaired axonal regeneration in alpha7 integrin-deficient mice.
AB - The interplay between growing axons and the extracellular substrate is pivotal
for directing axonal outgrowth during development and regeneration. Here we show
an important role for the neuronal cell adhesion molecule alpha7beta1 integrin
during peripheral nerve regeneration. Axotomy led to a strong increase of this
integrin on regenerating motor and sensory neurons, but not on the normally
nonregenerating CNS neurons. alpha7 and beta1 subunits were present on the axons
and their growth cones in the regenerating facial nerve. Transgenic deletion of
the alpha7 subunit caused a significant reduction of axonal elongation. The
associated delay in the reinnervation of the whiskerpad, a peripheral target of
the facial motor neurons, points to an important role for this integrin in the
successful execution of axonal regeneration.
PMID- 10684884
TI - Surviving granule cells of the sclerotic human hippocampus have reduced Ca(2+)
influx because of a loss of calbindin-D(28k) in temporal lobe epilepsy.
AB - In mesial temporal lobe epilepsy (mTLE), the predominant form of epilepsy in
adults, and in animal models of the disease, there is a conspicuous loss of the
intracellular Ca(2+)-binding protein calbindin-D(28k) (CB) from granule cells
(GCs) of the dentate gyrus. The role of this protein in nerve cell function is
controversial, but here we provide evidence for its role in controlling Ca(2+)
influx into human neurons. In patients with Ammon's horn sclerosis (AHS), the
loss of CB from GCs markedly increased the Ca(2+)-dependent inactivation of
voltage-dependent Ca(2+) currents (I(Ca)), thereby diminishing Ca(2+) influx
during repetitive neuronal firing. Introducing purified CB into GCs restored
Ca(2+) current inactivation to levels observed in cells with normal CB content
harvested from mTLE patients without AHS. Our data are consistent with the
possibility of neuroprotection secondary to the CB loss. By limiting Ca(2+)
influx through an enhanced Ca(2+)-dependent inactivation of voltage-dependent
Ca(2+) channels during prolonged neuronal discharges, the loss of CB may
contribute to the resistance of surviving human granule cells in AHS.
PMID- 10684885
TI - Serotonin-driven long-range inhibitory connections in the cerebellar cortex.
AB - Disturbances of the serotoninergic neuromodulation in the cerebellar cortex have
been involved in several types of ataxia, but the physiological action of
serotonin in this structure remains poorly understood. We report that in slices
of the rat cerebellar vermis, serotonin triggers the firing of an inhibitory
interneuron presynaptic to Golgi cells. The Lugaro cell, a neglected
interneuronal type, satisfies the expected criteria for this input, whereas
basket cells, stellate cells, or Golgi cells do not. Lugaro cells are selectively
excited by serotonin, and their firing behavior (sustained steady frequency in
the 5-15 Hz range) resembles the pattern of occurrence of serotonin-evoked IPSCs
in Golgi cells. Immunohistochemical stainings and single cell reconstructions
show that Lugaro cell axons form a parasagittal plexus but also extend long
transverse branches that run parallel to the parallel fibers and are partly
myelinated. Electrophysiological data suggest that these transverse axons
participate in synaptic contacts of the Lugaro cells with Golgi cells, and we
calculated that in the intact cerebellum a given Lugaro cell contacts >100 Golgi
cells. Serotonin modulation of Lugaro cells may constitute an intracortical
switch involved in information patterning at the level of Golgi cells and granule
cells populations, and particularly in synchronizations recorded along the
transverse axis in vivo.
PMID- 10684886
TI - Activation of extracellular signal-regulated protein kinases is associated with a
sensitized locomotor response to D(2) dopamine receptor stimulation in unilateral
6-hydroxydopamine-lesioned rats.
AB - Evidence indicates that mitogen-activated protein kinase (MAPK) pathways play a
crucial role in the neurobiology of the nervous system. In the present study,
dopamine receptor-mediated regulation of extracellular signal-regulated kinases
(ERKs) was examined in rats in which the nigrostriatal dopaminergic pathway was
unilaterally lesioned by 6-hydroxydopamine (6-OHDA). Subcutaneous injections of
the D(2) receptor agonist quinpirole significantly increased tyrosine
phosphorylated ERK1/2 in lesioned striatum, whereas the D(1) receptor agonist
SKF38393 failed to activate ERKs. Quinpirole-induced phosphorylation of ERK1/2
was seen as early as 3 min and peaked at 15 min after the challenge. In parallel,
striatal ERK kinase activity, measured by the in vitro kinase assay, was
increased 2.5-fold on the lesioned side after the administration of quinpirole.
Immunohistochemical examination of brain sections after quinpirole administration
revealed significant increases in ERK1/2 immunostaining in perinuclear and
intranuclear areas of striatal neurons. This increase was much more pronounced on
the lesioned than the intact side. Furthermore, quinpirole-induced contralateral
rotation was decreased by 48.7 and 50.7%, respectively, when the striatal ERK
pathway was selectively inhibited by a single intrastriatal injection of the
MAPK/ERK kinase inhibitor PD098059 or after a continuous 7 d intrastriatal
infusion of ERK1/2 antisense oligodeoxynucleotide. The results demonstrate, for
the first time, that the ERK signaling pathway is activated in denervated
striatum in response to stimulation of D(2) dopamine receptors and that the
resulting imbalance in striatal ERK activity contributes, at least in part, to
neuronal plasticity that underlies D(2) dopamine receptor-mediated contralateral
rotation in unilateral 6-OHDA denervated rats.
PMID- 10684887
TI - Embryonic and early fetal development of the human neocortex.
AB - Early corticogenesis was studied in human embryos and early fetuses from Carnegie
stages 16 to 22 (5-8 gestational weeks) by using immunohistochemistry for Reelin
(Reln), calretinin (CR), and glutamic acid decarboxylase (GAD). A first
population of Reln-positive cells appears in the neocortical anlage at stage 16
and increases in number at stages 17-18. At stages 19-20, a monolayer of
horizontal CR- and GAD-positive, Reln-negative neurons forms in the preplate,
whereas Reln-positive cells shift into a subpial position. Another cell class,
the pioneer projection neuron, is CR-positive but GAD- and Reln-negative; pioneer
cells contribute early corticofugal axons. Pioneer cells first appear below the
monolayer at stage 20 and form a pioneer plate at stage 21. The cortical plate
(CP) proper emerges at stage 21 and inserts itself within the pioneer plate,
which is thus split into a minor superficial component and a larger deep
component that presumably corresponds to the subplate. Initial CP neurons are
radially organized and mostly CR-negative. Reln-positive cells remain
consistently segregated from the pioneer cells and are thus not directly involved
in preplate partition. Our data indicate that the neuronal composition of the
human neocortical preplate is more complex than generally described and that
various neurons participate in a sequence of events that precede the emergence of
the CP.
PMID- 10684888
TI - Expression of Kv1 potassium channels in mouse hippocampal primary cultures:
development and activity-dependent regulation.
AB - Excitability and discharge behavior of neurons depends on the highly variable
expression pattern of voltage-dependent potassium (Kv) channels throughout the
nervous system. To learn more about distribution, development, and activity
dependent regulation of Kv channel subunit expression in the rodent hippocampus,
we studied the protein expression of members of the Kv1 subfamily in mouse
hippocampus in situ and in primary cultures. In adult hippocampus, Kv1 (1-6)
channel alpha-subunits were present, whereas at postnatal day 2, none of these
proteins could be detected in CA1-CA3 and dentate gyrus. Kv1.1 was the first
channel to be observed at postnatal day 6. The delayed postnatal expression and
most of the subcellular distribution observed in hippocampal sections were
mimicked by cultured hippocampal neurons in which Kv channels appeared only after
10 days in vitro. This developmental upregulation was paralleled by a dramatic
increase in total K(+) current, as well as an elevated GABA release in the
presence of 4-aminopyridine. Thus, the developmental profile, subcellular
localization, and functionality of Kv1 channels in primary culture of hippocampus
closely resembles the in situ situation. Impairing secretion by clostridial
neurotoxins or blocking activity by tetrodotoxin inhibited the expression of
Kv1.1, Kv1.2, and Kv1.4, whereas the other Kv1 channels still appeared. This
activity-dependent depression was only observed before the initial appearance of
the respective channels and lost after they had been expressed. Our data show
that hippocampal neurons in culture are a convenient model to study the
developmental expression and regulation of Kv1 channels. The ontogenetic
regulation and the activity-dependent expression of Kv1.1, Kv1.2, and Kv1.4
indicate that neuronal activity plays a crucial role for the development of the
mature Kv channel pattern in hippocampal neurons.
PMID- 10684889
TI - Disruption of the olfactoretinal centrifugal pathway may relate to the visual
system defect in night blindness b mutant zebrafish.
AB - We describe here a dominant mutation, night blindness b (nbb), which causes an
age-related visual system defect in zebrafish. At 4-5 months of age, dark-adapted
nbb(+/-) mutants show abnormal visual threshold fluctuations when measured
behaviorally. Light sensitizes the animals; thus early dark adaptation of nbb(+/
) fish is normal. After 2 hr of dark adaptation, however, visual thresholds of
nbb(+/-) mutants are raised on average 2-3 log units, and rod system function is
not detectable. Electroretinograms recorded from nbb(+/-) mutants are normal, but
ganglion cell thresholds are raised in prolonged darkness, suggesting an inner
retinal defect. The visual defect of nbb(+/-) mutants may be likely caused by an
abnormal olfactoretinal centrifugal innervation; in nbb(+/-) mutants, the
olfactoretinal centrifugal projection to the retina is disrupted, and the number
of retinal dopaminergic interplexiform cells is reduced. A similar visual defect
as shown by nbb(+/-) mutants is observed in zebrafish in which the olfactory
epithelium and olfactory bulb have been excised. Homozygous nbb fish display an
early onset neural degeneration throughout the CNS and die by 7-8 d of age.
PMID- 10684890
TI - Effects of dopamine depletion on visual sensitivity of zebrafish.
AB - The visual sensitivity of zebrafish in which the retinal dopaminergic
interplexiform cells (DA-IPCs) were destroyed by 6-hydroxydopamine was measured
behaviorally. During the first 6-8 min of dark adaptation, visual thresholds of
DA-IPC-depleted animals were similar to those of control animals. Thereafter,
their visual thresholds were elevated so that by 14-18 min of dark adaptation,
they were 2-3 log units above those of control animals. In DA-IPC-depleted
animals, the electroretinogram was normal in terms of light sensitivity and
waveform, but the light threshold for eliciting a ganglion cell discharge was
raised by 1.8 log units as compared with control animals. No obvious rod system
function was detected in DA-IPC-depleted animals as measured behaviorally.
Partial rescue of the behavioral visual sensitivity loss in DA-IPC-depleted
animals occurred when dopamine or a long-acting dopamine agonist (2-amino-6, 7
dihydroxy-1, 2, 3, 4-tetrahydronaphthalene hydrobromide) were injected
intraocularly. Our data suggest that the principal visual defect shown by DA-IPC
depleted animals is attributable to effects occurring in the inner retina, mainly
on rod signals. We also show that dopamine is involved in mediating the effect of
the circadian clock on visual sensitivity.
PMID- 10684891
TI - Brain-derived neurotrophic factor acutely inhibits AMPA-mediated currents in
developing sensory relay neurons.
AB - Brain-derived neurotrophic factor (BDNF) is expressed by many primary sensory
neurons that no longer require neurotrophins for survival, indicating that BDNF
may be used as a signaling molecule by the afferents themselves. Because many
primary afferents also express glutamate, we investigated the possibility that
BDNF modulates glutamatergic AMPA responses of newborn second-order sensory relay
neurons. Perforated-patch, voltage-clamp recordings were made from dissociated
neurons of the brainstem nucleus tractus solitarius (nTS), a region that receives
massive primary afferent input from BDNF-containing neurons in the nodose and
petrosal cranial sensory ganglia. Electrophysiological analysis was combined in
some experiments with anterograde labeling of primary afferent terminals to
specifically analyze responses of identified second-order neurons. Our data
demonstrate that BDNF strongly inhibits AMPA-mediated currents in a large subset
of nTS cells. Specifically, AMPA responses were either completely abolished or
markedly inhibited by BDNF in 73% of postnatal day (P0) cells and in 82% of
identified P5 second-order sensory relay neurons. This effect of BDNF is mimicked
by NT-4, but not NGF, and blocked by the Trk tyrosine kinase inhibitor K252a,
consistent with a requirement for TrkB receptor activation. Moreover, analysis of
TrkB expression in culture revealed a close correlation between the percentage of
nTS neurons in which BDNF inhibits AMPA currents and the percentage of neurons
that exhibit TrkB immunoreactivity. These data document a previously undefined
mechanism of acute modulation of AMPA responses by BDNF and indicate that BDNF
may regulate glutamatergic transmission at primary afferent synapses.
PMID- 10684892
TI - Afferent regulation of inhibitory synaptic transmission in the developing
auditory midbrain.
AB - To determine whether afferent innervation regulates the strength of inhibitory
connections in the gerbil auditory midbrain, both cochleas were surgically
removed in postnatal day 7 animals, before sound-driven activity is first
observed. Inhibitory synaptic currents were measured in a brain slice preparation
1-7 d after the ablations. Whole-cell and gramicidin-perforated patch recordings
were obtained from inferior colliculus neurons, and IPSCs were evoked by
stimulation of the commissure of the inferior colliculus (CIC) or the ipsilateral
lateral lemniscus (LL) in the presence of kynurenic acid. Deafferentation led to
a 24 mV depolarizing shift in the IPSC equilibrium potential within 1 d of
deafferentation. As a consequence, there was a large reduction of IPSC amplitude
at a holding potential of -20 mV in neurons from bilaterally ablated animals.
Furthermore, both afferent pathways displayed a 50% reduction of the inhibitory
synaptic conductance after deafferentation, indicating that driving force was not
solely responsible for the decline in IPSC amplitude. When paired pulses were
delivered to the LL or CIC pathway in control neurons, the evoked IPSCs exhibited
facilitation. However, paired pulse facilitation was nearly eliminated after
deafferentation. Thus, normal innervation affects inhibitory synaptic strength by
regulating postsynaptic chloride homeostasis and presynaptic transmitter release
properties.
PMID- 10684893
TI - Cortical cell orientation selectivity fails to develop in the absence of ON
center retinal ganglion cell activity.
AB - Neuronal activity is necessary for the normal development of visual cortical cell
receptive fields. When neuronal activity is blocked, cortical cells fail to
develop normal ocular dominance and orientation selectivity. Patterned activity
has been shown to play an instructive, rather than merely permissive, role in the
segregation of geniculocortical afferents into ocular dominance columns. To test
whether normal patterns of activity are necessary to instruct the development of
cortical orientation selectivity, we studied ferrets raised without ON-center
retinal ganglion cell activity. The ON-center blockade was produced by daily
intravitreal injections of DL-2-amino-4-phosphonobutyric acid (APB). Effects of
this treatment on the development of orientation selectivity in primary visual
cortex were assessed using extracellular electrode recordings and optical
imaging. In animals raised with an ON-center blockade starting after visual
cortical cells are visually driven but still poorly tuned for orientation,
cortical cell responsivity was maintained, but no maturation of orientation
selectivity was seen. No recovery of orientation tuning was seen in animals
treated with APB during the normal period of orientation development and then
allowed several months of development without treatment. These results suggest
that patterns of neuronal activity carried in the separate ON- and OFF-center
visual pathways are necessary for the development of orientation selectivity in
visual cortical neurons of the ferret and that there is a critical period for
this development.
PMID- 10684894
TI - Properties of horizontal and vertical inputs to pyramidal cells in the
superficial layers of the cat visual cortex.
AB - The purpose of this study is to elucidate the integrative input mechanisms of
pyramidal cells receiving horizontally projecting axon collaterals (horizontal
projection) and vertical input from layer IV. We performed whole-cell recordings
from pyramidal cells in layer II/III and focally activated other single pyramidal
cells monosynaptically connected via long-distance horizontal (LH) projections
(the distance between presynaptic and postsynaptic cells was 350-1200 micrometer)
in slice preparations of the kitten primary visual cortex. In addition,
presynaptic single fibers in layer IV (vertical input) and/or short-distance
horizontal (SH) inputs from neighboring single pyramidal cells (distance within
100 micrometer) in layer II/III were activated. Unitary EPSPs evoked by the
activation of LH and SH connections had smaller amplitude and larger coefficient
of variation than those evoked by stimulating the vertical input. Paired-pulse
stimulation of the LH and SH inputs caused the depression of the second EPSP,
whereas that of vertical inputs caused either facilitation or depression of the
second EPSP. The EPSPs evoked by simultaneous activation of LH and vertical
inputs summated linearly at the resting membrane potential. However, the EPSPs
evoked by stimulation of the two inputs were nonlinearly (supralinearly) summated
when the postsynaptic membrane was depolarized to a certain level. Similar EPSP
interaction was observed in response to simultaneous activation of the LH and SH
inputs.
PMID- 10684895
TI - Three levels of lateral inhibition: A space-time study of the retina of the tiger
salamander.
AB - The space-time patterns of activity generated across arrays of retinal neurons
can provide a sensitive measurement of the effects of neural interactions
underlying retinal activity. We measured the excitatory and inhibitory components
associated with these patterns at each cellular level in the retina and further
dissected inhibitory components pharmacologically. Using perforated and loose
patch recording, we measured the voltages, currents, or spiking at 91 lateral
positions covering approximately 2 mm in response to a flashed 300-microm-wide
bar. First, we showed how the effect of well known lateral inhibition at the
outer retina, mediated by horizontal cells, evolved in time to compress the
spatial representation of the stimulus bar at ON and OFF bipolar cell bodies as
well as horizontal cells. Second, we showed, for the first time, how GABA(C)
receptor mediated amacrine cell feedback to bipolar terminals compresses the
spatial representation of the stimulus bar at ON bipolar terminals over time.
Third, we showed that a third spatiotemporal compression exists at the ganglion
cell layer that is mediated by feedforward amacrine cells via GABA(A) receptors.
These three inhibitory mechanisms, via three different receptor types, appear to
compensate for the effects of lateral diffusion of activity attributable to
dendritic spread and electrical coupling between retinal neurons. As a
consequence, the width of the final representation at the ganglion cell level
approximates the dimensions of the original stimulus bar.
PMID- 10684896
TI - Dual serotonin (5-HT) projections to the nucleus accumbens core and shell:
relation of the 5-HT transporter to amphetamine-induced neurotoxicity.
AB - Dopamine release in the nucleus accumbens (NAc) has been implicated as mediating
the rewarding effects of stimulant drugs; however, recent studies suggest that 5
HT release may also contribute. In an effort to assess the role of 5-HT in drug
mediated reward, this study analyzed the serotonergic innervation of NAc using
immunocytochemistry for 5-HT and the 5-HT transporter (SERT). We report that in
control rats the NAc receives two distinct types of 5-HT axons that differ in
regional distribution, morphology, and SERT expression. Most regions of the NAc
are innervated by thin 5-HT axons that express SERT, but in the caudal NAc shell
nearly all 5-HT axons lack SERT and have large spherical varicosities. Two weeks
after methamphetamine or p-chloroamphetamine (PCA) treatment, most 5-HT axons in
dorsal striatum and NAc have degenerated; however, the varicose axons in the
shell appear intact. These drug-resistant 5-HT axons that lack SERT densely
innervate the caudal one-third of the accumbens shell, the same location where
dopamine axons are spared after methamphetamine. Moreover, 4 hr after PCA, the
varicose axons in the caudal shell retain prominent stores of 5-HT, whereas 5-HT
axons in the rest of the NAc are depleted of neurotransmitter. The results
demonstrate that two functionally different 5-HT projections innervate separate
regions of the NAc and that selective vulnerability to amphetamines may result
from differential expression of SERT. We postulate that action potentials
conducted from the raphe nuclei can release 5-HT throughout the NAc, whereas
transporter-mediated release induced by stimulant drugs is more restricted and
unlikely to occur in the caudal NAc shell.
PMID- 10684897
TI - Interspike intervals, receptive fields, and information encoding in primary
visual cortex.
AB - In the primate primary visual cortex (V1), the significance of individual action
potentials has been difficult to determine, particularly in light of the
considerable trial-to-trial variability of responses to visual stimuli. We show
here that the information conveyed by an action potential depends on the duration
of the immediately preceding interspike interval (ISI). The interspike intervals
can be grouped into several different classes on the basis of reproducible
features in the interspike interval histograms. Spikes in different classes bear
different relationships to the visual stimulus, both qualitatively (in terms of
the average stimulus preceding each spike) and quantitatively (in terms of the
amount of information encoded per spike and per second). Spikes preceded by very
short intervals (3 msec or less) convey information most efficiently and
contribute disproportionately to the overall receptive-field properties of the
neuron. Overall, V1 neurons can transmit between 5 and 30 bits of information per
second in response to rapidly varying, pseudorandom stimuli, with an efficiency
of approximately 25%. Although some (but not all) of our results would be
expected from neurons that use a firing-rate code to transmit information, the
evidence suggests that visual neurons are well equipped to decode stimulus
related information on the basis of relative spike timing and ISI duration.
PMID- 10684898
TI - Conscious and unconscious processing of nonverbal predictability in Wernicke's
area.
AB - The association of nonverbal predictability and brain activation was examined
using functional magnetic resonance imaging in humans. Participants regarded four
squares displayed horizontally across a screen and counted the incidence of a
particular color. A repeating spatial sequence with varying levels of
predictability was embedded within a random color presentation. Both Wernicke's
area and its right homolog displayed a negative correlation with temporal
predictability, and this effect was independent of individuals' conscious
awareness of the sequence. When individuals were made aware of the underlying
sequential predictability, a widespread network of cortical regions displayed
activity that correlated with the predictability. Conscious processing of
predictability resulted in a positive correlation to activity in right prefrontal
cortex but a negative correlation in posterior parietal cortex. These results
suggest that conscious processing of predictability invokes a large-scale
cortical network, but independently of awareness, Wernicke's area processes
predictive events in time and may not be exclusively associated with language.
PMID- 10684899
TI - Neuroactive steroid 3alpha-hydroxy-5alpha-pregnan-20-one modulates
electrophysiological and behavioral actions of ethanol.
AB - Neuroactive steroids are synthesized de novo in brain, yet their physiological
significance remains elusive. We provide biochemical, electrophysiological, and
behavioral evidence that several specific actions of alcohol (ethanol) are
mediated by the neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha
THP; allopregnanolone). Systemic alcohol administration elevates 3alpha, 5alpha
THP levels in the cerebral cortex to pharmacologically relevant concentrations.
The elevation of 3alpha,5alpha-THP is dose- and time-dependent. Furthermore,
there is a significant correlation between 3alpha,5alpha-THP levels in cerebral
cortex and the hypnotic effect of ethanol. Blockade of de novo biosynthesis of
5alpha-reduced steroids using the 5alpha-reductase inhibitor finasteride prevents
several effects of ethanol. Pretreatment with finasteride causes no changes in
baseline bicuculline-induced seizure threshold but reverses the anticonvulsant
effect of ethanol. Finasteride pretreatment also reverses ethanol inhibition of
spontaneous neural activity in medial septal/diagonal band of Broca neurons while
having no direct effect on spontaneous firing rates. Thus, elevation of
3alpha,5alpha-THP levels by acute ethanol administration represents a novel
mechanism of ethanol action as well as an important modulatory role for
neurosteroids in the CNS.
PMID- 10684900
TI - A proprioceptive role for an exteroceptive mechanoafferent neuron in Aplysia.
AB - Afferent regulation of centrally generated activity is likely to be more complex
than has been established. We show that a neuron that is an exteroceptor can also
function as a proprioceptor. We study the Aplysia neuron B21. Previous data
suggest that B21 functions as an exteroceptor during the radula
closing/retraction phase of ingestive feeding. We show that the tissue innervated
by B21, the subradula tissue (SRT), is innervated by a motor neuron (B66) and
that B66-induced SRT contractions trigger centripetal spikes in B21. Thus, B21 is
also a proprioceptor. To determine whether exteroceptive and proprioceptive
activities occur during the same phase of ingestive feeding, we further
characterize B66. We show that B66 stimulation does not close or retract the
radula. Instead it opens it. Moreover, B66 is electrically coupled to other
opening/protraction neurons. Finally, we elicit motor programs in semi-intact
preparations and show that during radula opening/protraction we observe B66
activity, SRT contractions, and spikes in B21 that can be eliminated if B66 is
indirectly hyperpolarized. B21 is, therefore, likely to act as an exteroceptor
during one phase of ingestive feeding and as a proprioceptor during the
antagonistic phase. Previous experiments have shown that centripetal spikes in
B21 are only transmitted to one follower if they are "gated in" by
depolarization. During ingestive programs B21 is centrally depolarized during
closing/retraction, but it is not depolarized during opening/protraction. We
sought to determine whether there are other followers that receive B21 input when
it is not centrally depolarized. We found one such cell. Moreover, we found that
stimulation of B21 during radula opening/protraction significantly decreases the
duration of this phase of behavior. Thus, proprioceptive activity in B21 is
likely to have an impact on motor programs.
PMID- 10684901
TI - Laminin degradation by plasmin regulates long-term potentiation.
AB - Plasmin is converted from its zymogen plasminogen by tissue type or urokinase
type plasminogen activator (PA) and degrades many components of the extracellular
matrix (ECM). To explore the possibility that the PA-plasmin system regulates
synaptic plasticity, we investigated the effect of plasmin on degradation of ECM
and synaptic plasticity by using organotypic hippocampal cultures. High-frequency
stimulation produced long-term potentiation (LTP) in control slices, whereas the
potentiation was induced but not maintained in slices pretreated with 100 nM
plasmin for 6 hr. The baseline synaptic responses were not affected by
pretreatment with plasmin. The impairment of LTP maintenance was not observed in
slices pretreated with 100 nM plasmin for 6 hr, washed, and then cultured for 24
48 hr in the absence of plasmin. To identify substrates of plasmin, the
expression of three major components of ECM, laminin, fibronectin, and type IV
collagen, was investigated by immunofluorescence imaging. The three ECM
components were widely distributed in the hippocampus, and only laminin was
degraded by plasmin pretreatment. The expression level of laminin returned to
normal levels when the slices were cultured for 24-48 hr after washout of
plasmin. Furthermore, preincubation with anti-laminin antibodies prevented both
the degradation of laminin and the impairment of LTP maintenance by plasmin.
These results suggest that the laminin-mediated cell-ECM interaction may be
necessary for the maintenance of LTP.
PMID- 10684902
TI - Long-lasting depolarizations in mitral cells of the rat olfactory bulb.
AB - We investigated the mechanisms of long-lasting depolarizing potentials (LLDs)
generated in mitral cells with whole-cell patch recordings in the rat olfactory
bulb slice. LLDs occur spontaneously and are evoked by either orthodromic
stimulation of the olfactory nerve or antidromic stimulation of mitral and tufted
(M/T) cells. LLDs are followed by a long refractory period, limiting LLD
generation to approximately 1 Hz. LLD production does not appear to involve
either intrinsic voltage-activated or metabotropic mechanisms. The initiation of
LLDs requires activation of non-NMDA but not NMDA receptors. Dual recordings from
the apical dendrites and somata of mitral cells show that LLDs are generated in
the distal portion of the apical dendrite, most likely in the glomerulus. The
rising phase of LLDs shows characteristics of polyneuronal input, including a
high variability and sensitivity to charge screening. Paired recordings from
adjacent mitral cells suggest that LLDs occur synchronously only in cells whose
apical dendrites ramify in the same glomerulus. These findings suggest that LLDs
involve recurrent, intraglomerular dendrodendritic interactions among M/T cells.
PMID- 10684903
TI - Modulation of presynaptic action potential kinetics underlies synaptic
facilitation of type B photoreceptors after associative conditioning in
Hermissenda.
AB - Descriptions of conditioned response generation in Hermissenda stipulate that the
synaptic interaction between type B and A photoreceptors should be enhanced after
associative pairings of light and rotation. Although evidence from several
laboratories has confirmed this assumption, the mechanism underlying this
synaptic facilitation has not been elucidated. Here we report that in vitro
conditioning (i.e., light paired with stimulation of vestibular hair cells)
modifies the kinetics of presynaptic action potentials in the B photoreceptor in
a manner sufficient to account for this synaptic facilitation. After paired
training, we observed an increase in the duration of evoked action potentials and
a decrease in the amplitude of the spike afterhyperpolarization in the B-cell. As
previously reported, paired training also enhanced the excitability (i.e., input
resistance and evoked spike rate) of the B photoreceptor. In a second experiment,
simultaneous recordings were made in type B and A photoreceptors, and paired
training was found to produce an increase in the amplitude of the IPSP in the A
photoreceptor in response to an evoked spike in the B-cell. Importantly, there
was no change in the initial slope of the postsynaptic IPSP in the A
photoreceptor, suggesting that spike duration-independent mechanisms of
neurotransmitter exocytosis or postsynaptic receptor sensitivity did not
contribute to the observed synaptic facilitation. Perfusion of 4-aminopyridine (4
AP) mimicked a known effect of behavioral conditioning in that it specifically
reduced the amplitude of the transient voltage-dependent K(+) current (I(A)) in
the B-cell, but in addition, produced action potential broadening and synaptic
facilitation that was analogous to that observed after in vitro conditioning.
Finally, the effect of 4-AP on B-cell action potentials and on the postsynaptic
IPSP in the A-cell was occluded by previous paired (but not unpaired) training,
suggesting that the prolongation of the B-cell action potential by a reduction of
I(A) was sufficient to account for the observed synaptic facilitation. The
occlusion of the effects of 4-AP by paired training was not attributable to a
saturation of the capacity of the B-cell for transmitter exocytosis, because it
was observed that tetraethylammonium (TEA)-induced inhibition of the delayed
voltage-dependent K(+) current induced both spike broadening and synaptic
facilitation regardless of training history. Collectively, these results
demonstrate that training-induced facilitation at B-cell synapses is attributable
to the effects of a reduction of a presynaptic K(+) conductance on action
potential kinetics and suggest another critical similarity between the cellular
basis for learning in Hermissenda and other invertebrate systems.
PMID- 10684904
TI - Peptide cotransmitter release from motorneuron B16 in aplysia californica:
costorage, corelease, and functional implications.
AB - Many neurons contain multiple peptide cotransmitters in addition to their
classical transmitters. We are using the accessory radula closer neuromuscular
system of Aplysia, which participates in feeding in these animals, to define the
possible consequences of multiple modulators converging on single targets. How
these modulators are released onto their targets is of critical importance in
understanding the outcomes of their modulatory actions and their physiological
role. Here we provide direct evidence that the partially antagonistic families of
modulatory peptides, the myomodulins and buccalins, synthesized by motorneuron
B16 are costored and coreleased in fixed ratios. We show that this release is
calcium-dependent and independent of muscle contraction. Furthermore, we show
that peptide release is initiated at the low end of the physiological range of
motorneuron firing frequency and that it increases with increasing motorneuron
firing frequency. The coordination of peptide release with the normal operating
range of a neuron may be a general phenomenon and suggests that the release of
peptide cotransmitters may exhibit similar types of regulation and plasticity as
have been observed for classical transmitters. Stimulation paradigms that
increase muscle contraction amplitude or frequency also increase peptide release
from motor neuron B16. The net effect of the modulatory peptide cotransmitters
released from motorneuron B16 would be to increase relaxation rate and therefore
allow more frequent and/or larger contractions to occur without increased
resistance to antagonist muscles. The end result of this modulation could be to
maximize the efficiency of feeding.
PMID- 10684905
TI - Fine structure of parvocellular receptive fields in the primate fovea revealed by
laser interferometry.
AB - Optical blurring in the eye prevents conventional physiological techniques from
revealing the fine structure of the small parvocellular receptive fields in the
primate fovea in vivo. We explored the organization of receptive fields in
macaque parvocellular lateral geniculate nucleus cells by using sinusoidal
interference fringes formed directly on the retina to measure spatial frequency
tuning at different orientations. Most parvocellular cells in and near the fovea
respond reliably to spatial frequencies up to and beyond 100 cycles/ degrees of
visual angle, implying center input arising mainly from a single cone. Temporal
frequency and contrast response characteristics were also measured at spatial
frequencies up to 130 cycles/degrees. We compared our spatial frequency data with
the frequency responses of model receptive fields that estimate the number,
configuration, and weights of cones that feed the center and surround. On the
basis of these comparisons, we infer possible underlying circuits. Most cells had
irregular spatial frequency-response curves that imply center input from more
than one cone. The measured responses are consistent with a single cone center
together with weak input from nearby cones. By exposing a fine structure that
cannot be discerned by conventional techniques, interferometry allows functional
measurements of the early neural mechanisms in spatial vision.
PMID- 10684906
TI - Control of synaptic depression by glutamate transporters.
AB - The role of glutamate transporters in the regulation of synaptic depression was
examined in the avian nucleus magnocellularis. Repetitive stimulation of
presynaptic auditory nerve fibers resulted in acute depression of EPSCs.
Pharmacological blockade of glutamate transport in glial cells enhanced residual
glutamate in the synaptic cleft and markedly increased the extent of depression
at stimulus frequencies above 20 Hz via a postsynaptic mechanism. Glutamate
pyruvate transaminase, a glutamate scavenger, accelerated the decay of the EPSC
and reduced synaptic depression, indicating that transporters are not completely
effective in rapid removal of glutamate. Regulation of residual transmitter by
glia may thus serve to control synaptic strength in a frequency-dependent manner.
PMID- 10684907
TI - Hypothalamic-pituitary-adrenal dysfunction in Apoe(-/-) mice: possible role in
behavioral and metabolic alterations.
AB - Several neurological diseases are frequently accompanied by dysregulation of the
hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates the secretion
of glucocorticoids (GCs), which play important roles in diverse brain functions,
including cognition, emotion, and feeding. Under physiological conditions, GCs
are adaptive and beneficial; however, prolonged elevations in GC levels may
contribute to neurodegeneration and brain dysfunction. In the current study, we
demonstrate that apolipoprotein E (apoE) deficiency results in age-dependent
dysregulation of the HPA axis through a mechanism affecting primarily the adrenal
gland. Apoe(-/-) mice, which develop neurodegenerative alterations as they age,
had an age-dependent increase in basal adrenal corticosterone content and
abnormally increased plasma corticosterone levels after restraint stress, whereas
their plasma and pituitary adrenocorticotropin levels were either unchanged or
lower than those in controls. HPA axis dysregulation was associated with
behavioral and metabolic alterations. When anxiety levels were assessed in the
elevated plus maze, Apoe(-/-) mice showed more anxiety than wild-type controls.
Apoe(-/-) mice also showed reduced activity in the open field. Finally, Apoe(-/-)
mice showed age-dependent increases in food and water intake, stomach and body
weights, and decreases in brown and white adipose tissues. These results support
a key role for apoE in the tonic inhibition of steroidogenesis and HPA axis
activity and have important implications for the behavioral analysis of Apoe(-/-)
mice.
PMID- 10684908
TI - Selectivity for complex shapes in primate visual area V2.
AB - To explore the role of visual area V2 in shape analysis, we studied the responses
of neurons in area V2 of the alert macaque using a set of 128 grating and
geometric line stimuli that varied in their shape characteristics and geometric
complexity. Simple stimuli included oriented bars and sinusoidal gratings;
complex stimuli included angles, arcs, circles, and intersecting lines, plus
hyperbolic and polar gratings. We found that most V2 cells responded well to at
least some of the complex stimuli, and in many V2 cells the most effective
complex stimulus elicited a significantly larger response than the most effective
bar or sinusoid. Approximately one-third of the V2 cells showed significant
differential responsiveness to various complex shape characteristics, and many
were also selective for the orientation, size, and/or spatial frequency of the
preferred shape. These results indicate that V2 cells explicitly represent
complex shape information and suggest specific types of higher order visual
information that V2 cells extract from visual scenes.
PMID- 10684909
TI - Distinct sites of opiate reward and aversion within the midbrain identified using
a herpes simplex virus vector expressing GluR1.
AB - Repeated administration of morphine increases expression of GluR1 (an AMPA
glutamate receptor subunit) in the ventral tegmental area (VTA) of the midbrain,
an important neural substrate for the rewarding actions of morphine.
Microinjections of a herpes simplex virus (HSV) vector that causes local
overexpression of GluR1 (HSV-GluR1) into the VTA can enhance the ability of
morphine to establish conditioned place preferences, suggesting that altered
GluR1 expression in this region is directly associated with changes in the
rewarding efficacy of morphine. We now report that in rats given HSV-GluR1
directly into the VTA, morphine is most rewarding when maximal transgene
expression is in the rostral VTA, whereas morphine is aversive when maximal
transgene expression is in the caudal VTA. Dual-labeling immunohistochemistry
shows that this difference cannot be explained by a different fraction of
dopaminergic neurons infected in the rostral versus caudal VTA. No such
anatomical specificity is seen in rats given VTA microinjections of HSV-LacZ, a
vector expressing a control protein (-galactosidase). These results suggest that
distinct substrates within the VTA itself differentially contribute to the
rewarding and aversive properties of opiates.
PMID- 10684910
TI - Cytokeratin-positive cells in the bone marrow and survival of patients with stage
I, II, or III breast cancer.
AB - BACKGROUND: Cytokeratins are specific markers of epithelial cancer cells in bone
marrow. We assessed the influence of cytokeratin-positive micrometastases in the
bone marrow on the prognosis of women with breast cancer. METHODS: We obtained
bone marrow aspirates from both upper iliac crests of 552 patients with stage I,
II, or III breast cancer who underwent complete resection of the tumor and 191
patients with nonmalignant disease. The specimens were stained with the
monoclonal antibody A45-B/B3, which binds to an antigen on cytokeratins. The
median follow-up was 38 months (range, 10 to 70). The primary end point was
survival. RESULTS: Cytokeratin-positive cells were detected in the bone marrow
specimens of 2 of the 191 control patients with nonmalignant conditions (1
percent) and 199 of the 552 patients with breast cancer (36 percent). The
presence of occult metastatic cells in bone marrow was unrelated to the presence
or absence of lymph-node metastasis (P=0.13). After four years of follow-up, the
presence of micrometastases in bone marrow was associated with the occurrence of
clinically overt distant metastasis and death from cancer-related causes
(P<0.001), but not with locoregional relapse (P=0.77). Of 199 patients with
occult metastatic cells, 49 died of cancer, whereas of 353 patients without such
cells, 22 died of cancer-related causes (P<0.001). Among the 301 women without
lymph-node metastases, 14 of the 100 with bone marrow micrometastases died of
cancer-related causes, as did 2 of the 201 without bone marrow micrometastases
(P<0.001). The presence of occult metastatic cells in bone marrow, as compared
with their absence, was an independent prognostic indicator of the risk of death
from cancer (relative risk, 4.17; 95 percent confidence interval, 2.51 to 6.94;
P<0.001), after adjustment for the use of systemic adjuvant chemotherapy.
CONCLUSIONS: The presence of occult cytokeratin-positive metastatic cells in bone
marrow increases the risk of relapse in patients with stage I, II, or III breast
cancer.
PMID- 10684911
TI - Metronidazole to prevent preterm delivery in pregnant women with asymptomatic
bacterial vaginosis. National Institute of Child Health and Human Development
Network of Maternal-Fetal Medicine Units.
AB - BACKGROUND: Bacterial vaginosis has been associated with preterm birth. In
clinical trials, the treatment of bacterial vaginosis in pregnant women who
previously had a preterm delivery reduced the risk of recurrence. METHODS: To
determine whether treating women in a general obstetrical population who have
asymptomatic bacterial vaginosis (as diagnosed on the basis of vaginal Gram's
staining and pH) prevents preterm delivery, we randomly assigned 1953 women who
were 16 to less than 24 weeks pregnant to receive two 2-g doses of metronidazole
or placebo. The diagnostic studies were repeated and a second treatment was
administered to all the women at 24 to less than 30 weeks' gestation. The primary
outcome was the rate of delivery before 37 weeks' gestation. RESULTS: Bacterial
vaginosis resolved in 657 of 845 women who had follow-up Gram's staining in the
metronidazole group (77.8 percent) and 321 of 859 women in the placebo group
(37.4 percent). Data on the time and characteristics of delivery were available
for 953 women in the metronidazole group and 966 in the placebo group. Preterm
delivery occurred in 116 women in the metronidazole group (12.2 percent) and 121
women in the placebo group (12.5 percent) (relative risk, 1.0; 95 percent
confidence interval, 0.8 to 1.2). Treatment did not prevent preterm deliveries
that resulted from spontaneous labor (5.1 percent in the metronidazole group vs.
5.7 percent in the placebo group) or spontaneous rupture of the membranes (4.2
percent vs. 3.7 percent), nor did it prevent delivery before 32 weeks (2.3
percent vs. 2.7 percent). Treatment with metronidazole did not reduce the
occurrence of preterm labor, intraamniotic or postpartum infections, neonatal
sepsis, or admission of the infant to the neonatal intensive care unit.
CONCLUSIONS: The treatment of asymptomatic bacterial vaginosis in pregnant women
does not reduce the occurrence of preterm delivery or other adverse perinatal
outcomes.
PMID- 10684912
TI - Orthostatic intolerance and tachycardia associated with norepinephrine
transporter deficiency.
AB - BACKGROUND: Orthostatic intolerance is a syndrome characterized by
lightheadedness, fatigue, altered mentation, and syncope and associated with
postural tachycardia and plasma norepinephrine concentrations that are
disproportionately high in relation to sympathetic outflow. We tested the
hypothesis that impaired functioning of the norepinephrine transporter
contributes to the pathophysiologic mechanism of orthostatic intolerance.
METHODS: In a patient with orthostatic intolerance and her relatives, we measured
postural blood pressure, heart rate, plasma catecholamines, and systemic
norepinephrine spillover and clearance, and we sequenced the norepinephrine
transporter gene and evaluated its function. RESULTS: The patient had a high mean
plasma norepinephrine concentration while standing, as compared with the mean (+/
SD) concentration in normal subjects (923 vs. 439+/-129 pg per milliliter [5.46
vs. 2.59+/-0.76 nmol per liter]), reduced systemic norepinephrine clearance (1.56
vs. 2.42+/-0.71 liters per minute), impairment in the increase in the plasma
norepinephrine concentration after the administration of tyramine (12 vs. 56+/-63
pg per milliliter [0.07 vs. 0.33+/-0.37 pmol per liter]), and a disproportionate
increase in the concentration of plasma norepinephrine relative to that of
dihydroxyphenylglycol. Analysis of the norepinephrine-transporter gene revealed
that the proband was heterozygous for a mutation in exon 9 (encoding a change
from guanine to cytosine at position 237) that resulted in more than a 98 percent
loss of function as compared with that of the wild-type gene. Impairment of
synaptic norepinephrine clearance may result in a syndrome characterized by
excessive sympathetic activation in response to physiologic stimuli. The mutant
allele in the proband's family segregated with the postural heart rate and
abnormal plasma catecholamine homeostasis. CONCLUSIONS: Genetic or acquired
deficits in norepinephrine inactivation may underlie hyperadrenergic states that
lead to orthostatic intolerance.
PMID- 10684913
TI - Images in clinical medicine. Pituitary apoplexy.
PMID- 10684914
TI - Clinical problems with the performance of euthanasia and physician-assisted
suicide in The Netherlands.
AB - BACKGROUND AND METHODS: The characteristics and frequency of clinical problems
with the performance of euthanasia and physician-assisted suicide are uncertain.
We analyzed data from two studies of euthanasia and physician-assisted suicide in
The Netherlands (one conducted in 1990 and 1991 and the other in 1995 and 1996),
with a total of 649 cases. We categorized clinical problems as technical
problems, such as difficulty inserting an intravenous line; complications, such
as myoclonus or vomiting; or problems with completion, such as a longer-than
expected interval between the administration of medications and death. RESULTS:
In 114 cases, the physician's intention was to provide assistance with suicide,
and in 535, the intention was to perform euthanasia. Problems of any type were
more frequent in cases of assisted suicide than in cases of euthanasia.
Complications occurred in 7 percent of cases of assisted suicide, and problems
with completion (a longer-than-expected time to death, failure to induce coma, or
induction of coma followed by awakening of the patient) occurred in 16 percent of
the cases; complications and problems with completion occurred in 3 percent and 6
percent of cases of euthanasia, respectively. The physician decided to administer
a lethal medication in 21 of the cases of assisted suicide (18 percent), which
thus became cases of euthanasia. The reasons for this decision included problems
with completion (in 12 cases) and the inability of the patient to take all the
medications (in 5). CONCLUSIONS: There may be clinical problems with the
performance of euthanasia and physician-assisted suicide. In The Netherlands,
physicians who intend to provide assistance with suicide sometimes end up
administering a lethal medication themselves because of the patient's inability
to take the medication or because of problems with the completion of physician
assisted suicide.
PMID- 10684915
TI - Physicians' experiences with the Oregon Death with Dignity Act.
AB - BACKGROUND: Physician-assisted suicide was legalized in Oregon in October 1997.
There are data on patients who have received prescriptions for lethal medications
and died after taking the medications. There is little information, however, on
physicians' experiences with requests for assistance with suicide. METHODS:
Between February and August 1999, we mailed a questionnaire to physicians who
were eligible to prescribe lethal medications under the Oregon Death with Dignity
Act. RESULTS: Of 4053 eligible physicians, 2649 (65 percent) returned the survey.
Of the respondents, 144 (5 percent) had received a total of 221 requests for
prescriptions for lethal medications since October 1997. We received information
on the outcome in 165 patients (complete information for 143 patients and partial
for on an additional 22). The mean age of the patients was 68 years; 76 percent
had an estimated life expectancy of less than six months. Thirty-five percent
requested a prescription from another physician. Twenty-nine patients (18
percent) received prescriptions, and 17 (10 percent) died from administering the
prescribed medication. Twenty percent of the patients had symptoms of depression;
none of these patients received a prescription for a lethal medication. In the
case of 68 patients, including 11 who received prescriptions and 8 who died by
taking the prescribed medication, the physician implemented at least one
substantive palliative intervention, such as control of pain or other symptoms,
referral to a hospice program, a consultation, or a trial of antidepressant
medication. Forty-six percent of the patients for whom substantive interventions
were made changed their minds about assisted suicide, as compared with 15 percent
of those for whom no substantive interventions were made (P<0.001). CONCLUSIONS:
Our data indicate that in Oregon, physicians grant about 1 in 6 requests for a
prescription for a lethal medication and that 1 in 10 requests actually result in
suicide. Substantive palliative interventions lead some--but not all--patients to
change their minds about assisted suicide.
PMID- 10684916
TI - Assessing the risk of breast cancer.
PMID- 10684917
TI - Case Records of the Massachusetts General Hospital. Weekly clinicopathological
exercises. Case 6-2000. Hemoptysis in a 20-year-old man with multiple pulmonary
nodules.
PMID- 10684918
TI - Approaches to breast-cancer staging.
PMID- 10684919
TI - Antibiotics for the prevention of preterm birth.
PMID- 10684920
TI - Physician-assisted suicide and euthanasia in practice.
PMID- 10684921
TI - Legalized physician-assisted suicide in Oregon--the second year.
AB - BACKGROUND AND METHODS: In 1997, Oregon legalized physician-assisted suicide. We
have previously reported data on terminally ill Oregon residents who received
prescriptions for lethal medications under the Oregon Death with Dignity Act and
who died in 1998. We now report similar data for 1999, obtained from physicians'
reports, death certificates, and interviews with physicians. We also report data
from interviews with family members. RESULTS: Information on 33 persons who
received prescriptions for lethal medications in 1999 was reported to the Oregon
Health Division; 26 died after taking the lethal medications, 5 died from their
underlying illnesses, and 2 were alive as of January 1, 2000. One additional
patient, who received a prescription in 1998, died after taking the medication in
1999. Thus, 27 patients died after ingesting lethal medications in 1999 (9 per
10,000 deaths in Oregon), as compared with 16 patients in 1998 (6 per 10,000).
The median age of the 27 patients who died in 1999 after taking lethal
medications was 71 years. The most frequent underlying illnesses were cancer (in
17 patients), amyotrophic lateral sclerosis (in 4), and chronic obstructive
pulmonary disease (in 4). All 27 patients had health insurance, 21 were receiving
hospice care, and 13 were college graduates. According to both physicians and
family members, patients requested assistance with suicide for several reasons,
including loss of autonomy, loss of control of bodily functions, an inability to
participate in activities that make life enjoyable, and a determination to
control the manner of death. CONCLUSIONS: In the second as compared with the
first year of legalized physician-assisted suicide in Oregon, the number of
patients who died after ingesting lethal medications increased, but it remained
small in relation to the total number of persons in Oregon who died. Patients who
request assistance with suicide appear to be motivated by several factors,
including loss of autonomy and a determination to control the way in which they
die.
PMID- 10684923
TI - Intronic GIY-YIG endonuclease gene in the mitochondrial genome of Podospora
curvicolla: evidence for mobility.
AB - Endonuclease genes encoded in invasive introns are themselves supposed to be
mobile elements which, during evolution, have colonized pre-existing introns
converting them into invasive elements. This hypothesis is supported by numerous
data concerning the LAGLI-DADG subclass of intronic endonucleases. Less is known
about the GIY-YIG ORFs which constitute another family of endonucleases. In this
paper we describe the presence of one optional GIY-YIG ORF in the second intron
of the mitochondrial cytochrome b gene in the fungus Podospora curvicolla. We
show that this GIY-YIG ORF is efficiently transferred from an ORF-containing
intron to an ORF-less allele. We also show that the products of both the GIY-YIG
ORF and the non-canonical LAGLI-DADG-GIY-YIG ORF, which is generated by its
integration, have endonuclease activities which recognize and cut the insertion
site of the optional sequence. This constitutes the first direct evidence for
potential mobility of an intronic GIY-YIG endonuclease. We discuss the role that
such a mobile sequence could have played during evolution.
PMID- 10684924
TI - Cold shock induces the insertion of a cryptic exon in the neurofibromatosis type
1 (NF1) mRNA.
AB - Alternative splicing is a regulatory process of gene expression based on the
flexibility in the selection of splice sites. In this manuscript we present the
characterisation of an alternative splicing of the NF1 pre-mRNA induced by cold
shock conditions. We demonstrate that the accuracy of the splicing mechanism was
perturbed after keeping samples for a short period of time at room temperature,
resulting in the insertion of a 31-bp cryptic exon between exons 4a and 4b of the
NF1 mRNA. This alternative splicing is not cell type specific and is not induced
by other stress conditions such as heat shock or hyper-osmolarity. The
alternative spliced mRNA is efficiently transported to the cytoplasm and it is
proven to belong to the poly A(+)mRNA fraction. Previous misleading
interpretations about this transcript, together with our finding relating its
presence to cold shock and not to the NF1 disease, strongly indicate that this
phenomenon should be taken into account in genetic testing when RNA methodology
is used for mutation detection. This is the first description of an alternative
splicing induced by cold shock in a human pre-mRNA and should provide further
insights into the factors that control alternative splicing.
PMID- 10684925
TI - Interaction of the yeast DExH-box RNA helicase prp22p with the 3' splice site
during the second step of nuclear pre-mRNA splicing.
AB - Using site-specific incorporation of the photo-chemical cross-linking reagent 4
thiouridine, we demonstrate the previously unknown association of two proteins
with yeast 3' splice sites. One of these is an unidentified approximately 122 kDa
protein that cross-links to 3' splice sites during formation of the pre-
spliceosome. The other factor is the DExH-box RNA helicase, Prp22p. With
substrates functional in the second step of splicing, only very weak cross
linking of Prp22p to intron sequences at the 3' splice site is observed. In
contrast, substrates blocked at the second step exhibit strong cross-linking of
Prp22 to intron sequences at the 3' splice site, but not to adjacent exon
sequences. In vitro reconstitution experiments also show that the association of
Prp22p with intron sequences at the 3' splice site is dependent on Prp16p and
does not persist when release of mature mRNA from the spliceosome is blocked.
Taken together, these results suggest that the 3' splice site of yeast introns is
contacted much earlier than previously envisioned by a protein of approximately
120 kDa, and that a transient association of Prp22p with the 3' splice site
occurs between the first and second catalytic steps.
PMID- 10684926
TI - The solution structure of [d(CGC)r(aaa)d(TTTGCG)](2): hybrid junctions flanked by
DNA duplexes.
AB - The solution structure and hydration of the chimeric duplex
[d(CGC)r(aaa)d(TTTGCG)](2), in which the central hybrid segment is flanked by DNA
duplexes at both ends, was determined using two-dimensional NMR, simulated
annealing and restrained molecular dynamics. The solution structure of this
chimeric duplex differs from the previously determined X-ray structure of the
analogous B-DNA duplex [d(CGCAAATTTGCG)](2)as well as NMR structure of the
analogous A-RNA duplex [r(cgcaaauuugcg)](2). Long-lived water molecules with
correlation time tau(c)longer than 0.3 ns were found close to the RNA adenine H2
and H1' protons in the hybrid segment. A possible long-lived water molecule was
also detected close to the methyl group of 7T in the RNA-DNA junction but not
with the other two thymines (8T and 9T). This result correlates with the
structural studies that only DNA residue 7T in the RNA-DNA junction adopts an O4'
endo sugar conformation, while the other DNA residues including 3C in the DNA-RNA
junction, adopt C1'-exo or C2'-endo conformations. The exchange rates for RNA C2'
OH were found to be approximately 5-20 s(-1). This slow exchange rate may be due
to the narrow minor groove width of [d(CGC)r(aaa)d(TTTGCG)](2), which may trap
the water molecules and restrict the dynamic motion of hydroxyl protons. The
minor groove width of [d(CGC)r(aaa)d(TTTGCG)](2)is wider than its B-DNA analog
but narrower than that of the A-RNA analog. It was further confirmed by its
titration with the minor groove binding drug distamycin. A possible 2:1 binding
mode was found by the titration experiments, suggesting that this chimeric duplex
contains a wider minor groove than its B-DNA analog but still narrow enough to
hold two distamycin molecules. These distinct structural features and hydration
patterns of this chimeric duplex provide a molecular basis for further
understanding the structure and recognition of DNA. RNA hybrid and chimeric
duplexes.
PMID- 10684922
TI - Survey and summary: transcription by RNA polymerases I and III.
AB - The task of transcribing nuclear genes is shared between three RNA polymerases in
eukaryotes: RNA polymerase (pol) I synthesizes the large rRNA, pol II synthesizes
mRNA and pol III synthesizes tRNA and 5S rRNA. Although pol II has received most
attention, pol I and pol III are together responsible for the bulk of
transcriptional activity. This survey will summarise what is known about the
process of transcription by pol I and pol III, how it happens and the proteins
involved. Attention will be drawn to the similarities between the three nuclear
RNA polymerase systems and also to their differences.
PMID- 10684927
TI - Interactions of the human, rat, Saccharomyces cerevisiae and Escherichia coli 3
methyladenine-DNA glycosylases with DNA containing dIMP residues.
AB - In DNA, the deamination of dAMP generates 2'-deoxy-inosine 5'-monophosphate
(dIMP). Hypoxanthine (HX) residues are mutagenic since they give rise to A.T-
>G.C transition. They are excised, although with different efficiencies, by an
activity of the 3-methyl-adenine (3-meAde)-DNA glycosylases from Escherichia coli
(AlkA protein), human cells (ANPG protein), rat cells (APDG protein) and yeast
(MAG protein). Comparison of the kinetic constants for the excision of HX
residues by the four enzymes shows that the E.coli and yeast enzymes are quite
inefficient, whereas for the ANPG and the APDG proteins they repair the HX
residues with an efficiency comparable to that of alkylated bases, which are
believed to be the primary substrates of these DNA glycosylases. Since the use of
various substrates to monitor the activity of HX-DNA glycosylases has generated
conflicting results, the efficacy of the four 3-meAde-DNA glycosylases of
different origin was compared using three different substrates. Moreover, using
oligo-nucleotides containing a single dIMP residue, we investigated a putative
sequence specificity of the enzymes involving the bases next to the HX residue.
We found up to 2-5-fold difference in the rates of HX excision between the
various sequences of the oligonucleotides studied. When the dIMP residue was
placed opposite to each of the four bases, a preferential recognition of dI:T
over dI:dG, dI:dC and dI:dA mismatches was observed for both human (ANPG) and
E.coli (AlkA) proteins. At variance, the yeast MAG protein removed more
efficiently HX from a dI:dG over dI:dC, dI:T and dI:dA mismatches.
PMID- 10684928
TI - Effects of RNA secondary structure on cellular antisense activity.
AB - The secondary and tertiary structures of a mRNA are known to effect hybridization
efficiency and potency of antisense oligonucleotides in vitro. Additional factors
including oligonucleotide stability and cellular uptake are also thought to
contribute to antisense potency in vivo. Each of these factors can be affected by
the sequence of the oligonucleotide. Although mRNA structure is presumed to be a
critical determinant of antisense activity in cells, to date little direct
experimental evidence has addressed the significance of structure. In order to
determine the importance of mRNA structure on antisense activity, oligonucleotide
target sites were cloned into a luciferase reporter gene along with adjoining
sequence to form known structures. This allowed us to study the effect of target
secondary structure on oligonucleotide binding in the cellular environment
without changing the sequence of the oligonucleotide. Our results show that
structure does play a significant role in determining oligonucleotide efficacy in
vivo. We also show that potency of oligonucleotides can be improved by altering
chemistry to increase affinity for the mRNA target even in a region that is
highly structured.
PMID- 10684929
TI - Characterisation of the U83 and U84 small nucleolar RNAs: two novel 2'-O-ribose
methylation guide RNAs that lack complementarities to ribosomal RNAs.
AB - In eukaryotic cells, the site-specific 2'- O -ribose methylation of ribosomal
RNAs (rRNAs) and the U6 spliceosomal small nuclear RNA (snRNA) is directed by
small nucleolar RNAs (snoRNAs). The C and D box-containing 2'- O -methylation
guide snoRNAs select the correct substrate nucleotide through formation of a long
10-21 bp interaction with the target rRNA and U6 snRNA sequences. Here, we report
on the characterisation of two novel mammalian C/D box snoRNAs, called U83 and
U84, that contain all the elements that are essential for accumulation and
function of 2'- O -methylation guide snoRNAs. However, in contrast to all of the
known 2'- O -methylation guide RNAs, the human, mouse and pig U83 and U84 snoRNAs
feature no antisense elements complementary to rRNA or U6 snRNA sequences. The
human U83 and U84 snoRNAs are not associated with maturing nucleolar pre
ribosomal particles, suggesting that they do not function in rRNA biogenesis.
Since artificial substrate RNAs complementary to the evolutionarily conserved
putative substrate recognition motifs of the U83 and U84 snoRNAs were correctly
2'- O -methylated in the nucleolus of mouse cells, we suggest that the new
snoRNAs act as 2'- O -methylation guides for cellular RNAs other then rRNAs and
the U6 snRNA.
PMID- 10684930
TI - Identification of human MutY homolog (hMYH) as a repair enzyme for 2
hydroxyadenine in DNA and detection of multiple forms of hMYH located in nuclei
and mitochondria.
AB - An enzyme activity introducing an alkali-labile site at 2-hydroxyadenine (2-OH-A)
in double-stranded oligonucleotides was detected in nuclear extracts of Jurkat
cells. This activity co-eluted with activities toward adenine paired with guanine
and 8-oxo-7,8-dihydroguanine (8-oxoG) as a single peak corresponding to a 55 kDa
molecular mass on gel filtration chromatography. Further co-purification was then
done. Western blotting revealed that these activities also co-purified with a 52
kDa polypeptide which reacted with antibodies against human MYH (anti-hMYH).
Recombinant hMYH has essentially similar activities to the partially purified
enzyme. Thus, hMYH is likely to possess both adenine and 2-OH-A DNA glycosylase
activities. In nuclear extracts from Jurkat cells, a 52 kDa polypeptide was
detected with a small amount of 53 kDa polypeptide, while in mitochondrial
extracts a 57 kDa polypeptide was detected using anti-hMYH. With amplification of
the 5'-regions of the hMYH cDNA, 10 forms of hMYH transcripts were identified and
subgrouped into three types, each with a unique 5' sequence. These hMYH
transcripts are likely to encode multiple authentic hMYH polypeptides including
the 52, 53 and 57 kDa polypeptides detected in Jurkat cells.
PMID- 10684931
TI - Assembly of archaeal signal recognition particle from recombinant components.
AB - Signal recognition particle (SRP) takes part in protein targeting and secretion
in all organisms. Searches for components of archaeal SRP in primary databases
and completed genomes indicated that archaea possess only homologs of SRP RNA,
and proteins SRP19 and SRP54. A recombinant SRP was assembled from cloned,
expressed and purified components of the hyperthermophilic archaeon Archaeoglobus
fulgidus. Recombinant Af-SRP54 associated with the signal peptide of bovine pre
prolactin translated in vitro. As in mammalian SRP, Af-SRP54 binding to Af-SRP
RNA required protein Af-SRP19, although notable amounts bound in absence of Af
SRP19. Archaeoglobus fulgidus SRP proteins also bound to full-length SRP RNA of
the archaeon Methanococcus jannaschii, to eukaryotic human SRP RNA, and to
truncated versions which corresponded to the large domain of SRP. Dependence on
SRP19 was most pronounced with components from the same species. Reconstitutions
with heterologous components revealed a significant potential of human SRP
proteins to bind to archaeal SRP RNAs. Surprisingly, M.jannaschii SRP RNA bound
to human SRP54M quantitatively in the absence of SRP19. This is the first report
of reconstitution of an archaeal SRP from recombinantly expressed purified
components. The results highlight structural and functional conservation of SRP
assembly between archaea and eucarya.
PMID- 10684932
TI - Modified constructs of the tRNA TPsiC domain to probe substrate conformational
requirements of m(1)A(58) and m(5)U(54) tRNA methyltransferases.
AB - The TPsiC stem and loop (TSL) of tRNA contains highly conserved nucleoside
modifications, m(5)C(49), T(54), Psi(55)and m(1)A(58). U(54)is methylated to
m(5)U (T) by m(5)U(54)methyltransferase (RUMT); A(58)is methylated to m(1)A by
m(1)A(58)tRNA methyltransferase (RAMT). RUMT recognizes and methylates a minimal
TSL heptadecamer and RAMT has previously been reported to recognize and methylate
the 3'-half of the tRNA molecule. We report that RAMT can recognize and methylate
a TSL heptadecamer. To better understand the sensitivity of RAMT and RUMT to TSL
conformation, we have designed and synthesized variously modified TSL constructs
with altered local conformations and stabilities. TSLs were synthesized with
natural modifications (T(54)and Psi(55)), naturally occurring modifications at
unnatural positions (m(5)C(60)), altered sugar puckers (dU(54)and/or dU(55)) or
with disrupted U-turn interactions (m(1)Psi(55)or m(1)m(3)Psi(55)). The
unmodified heptadecamer TSL was a substrate of both RAMT and RUMT. The presence
of T(54)increased thermal stability of the TSL and dramatically reduced RAMT
activity toward the substrate. Local conformation around U(54)was found to be an
important determinant for the activities of both RAMT and RUMT.
PMID- 10684933
TI - Characterization of a cis-acting regulatory element in the protein coding region
of thymidylate synthase mRNA.
AB - Thymidylate synthase (TS) functions as an RNA-binding protein by interacting with
two different sequences on its own mRNA. One site is located in the 5'-upstream
region of human TS mRNA while the second site is located within the protein
coding region corresponding to nt 434-634. In this paper, a 70 nt RNA sequence,
corresponding to nt 480-550, was identified that binds TS protein with an
affinity similar to that of full-length TS mRNA and TS434-634 RNA. In vitro
translation studies confirmed that this sequence is critical for the
translational autoregulatory effects of TS. To document in vivo biological
significance, TS sequences contained within this region were cloned onto the 5'
end of a luciferase reporter plasmid and transient transfection experiments were
performed using H630 human colon cancer cells. In cells transfected with
p644/TS434-634 or p644/TS480-550, luciferase activity was decreased 2.5-fold when
compared to cells transfected with p644 plasmid alone. Luciferase mRNA levels
were identical for each of these conditions as determined by RNase protection and
RT-PCR analysis. Immunoprecipitation of TS ribonucleoprotein complexes revealed a
direct interaction between TS protein and TS480-550 RNA in transfected H630
cells. Treatment with 5-fluorouridine resulted in a nearly 2-fold increase in
luciferase activity only in cells transfected with p644/TS434-634 and p644/TS480
550. This study identifies a 70 nt TS response element in the protein coding
region of TS mRNA with in vitro and in vivo translational regulatory activity.
PMID- 10684934
TI - Different roles for abf1p and a T-rich promoter element in nucleosome
organization of the yeast RPS28A gene.
AB - In vivo mutational analysis of the yeast RPS28A ribosomal protein (rp-)gene
promoter demonstrated that both the Abf1p binding site and the adjacent T-rich
element are essential for efficient transcription. In vivo Mnase and DNaseI
digestion showed that the RPS28A promoter contains a 50-60 bp long nucleosome
free region directly downstream from the Abf1p binding site, followed by an
ordered array of nucleosomes. Mutating either the Abf1p binding site or the T
rich element has dramatic, but different, effects on the local chromatin
structure. Failure to bind Abf1p appears to cause nucleosome positioning to
become disorganized as concluded from the complete disappearance of Mnase
hypersensitive sites. On the other hand, mutation of the T-rich element causes
the downstream nucleosomal array to shift by approximately 50 bp towards the
Abf1p site, resulting in loss of the nucleosome-free region downstream of Abf1p.
We conclude that Abf1p is a strong organizer of local chromatin structure that
appears to act as a nucleosomal boundary factor requiring the downstream T-rich
element to create a nucleosome-free region.
PMID- 10684935
TI - Genome sequences of Chlamydia trachomatis MoPn and Chlamydia pneumoniae AR39.
AB - The genome sequences of Chlamydia trachomatis mouse pneumonitis (MoPn) strain
Nigg (1 069 412 nt) and Chlamydia pneumoniae strain AR39 (1 229 853 nt) were
determined using a random shotgun strategy. The MoPn genome exhibited a general
conservation of gene order and content with the previously sequenced
C.trachomatis serovar D. Differences between C.trachomatis strains were focused
on an approximately 50 kb 'plasticity zone' near the termination origins. In this
region MoPn contained three copies of a novel gene encoding a >3000 amino acid
toxin homologous to a predicted toxin from Escherichia coli O157:H7 but had
apparently lost the tryptophan biosyntheis genes found in serovar D in this
region. The C. pneumoniae AR39 chromosome was >99.9% identical to the previously
sequenced C.pneumoniae CWL029 genome, however, comparative analysis identified an
invertible DNA segment upstream of the uridine kinase gene which was in different
orientations in the two genomes. AR39 also contained a novel 4524 nt circular
single-stranded (ss)DNA bacteriophage, the first time a virus has been reported
infecting C. pneumoniae. Although the chlamydial genomes were highly conserved,
there were intriguing differences in key nucleotide salvage pathways:
C.pneumoniae has a uridine kinase gene for dUTP production, MoPn has a uracil
phosphororibosyl transferase, while C.trachomatis serovar D contains neither
gene. Chromosomal comparison revealed that there had been multiple large
inversion events since the species divergence of C.trachomatis and C.pneumoniae,
apparently oriented around the axis of the origin of replication and the
termination region. The striking synteny of the Chlamydia genomes and prevalence
of tandemly duplicated genes are evidence of minimal chromosome rearrangement and
foreign gene uptake, presumably owing to the ecological isolation of the obligate
intracellular parasites. In the absence of genetic analysis, comparative genomics
will continue to provide insight into the virulence mechanisms of these important
human pathogens.
PMID- 10684936
TI - A new double-stranded RNA-binding protein that interacts with PKR.
AB - We have identified a 74 kDa double-stranded (ds)RNA-binding protein that shares
extensive homology with the mouse spermatid perinuclear RNA-binding (Spnr)
protein. p74 contains two dsRNA-binding motifs (dsRBMs) that are essential for
preferential binding to dsRNA. Previously, dsRNA-binding proteins were shown to
undergo homo- and heterodimerization, raising the possibility that regulation of
activity could be controlled by interactions between different family members.
Homodimerization is required to activate the dsRNA-dependent protein kinase PKR,
whereas hetero-dimerization between PKR and other dsRNA-binding proteins can
inhibit kinase activity. We have found that p74 also interacts with PKR, both the
wild-type enzyme and a catalytically defective mutant (K296R). While co
expression of p74 and wild-type PKR in the yeast Saccharomyces cerevisiae did not
alter PKR activity, co-expression of p74 and the catalytically defective K296R
mutant surprisingly resulted in abnormal morphology and cell death in
transformants that maintained a high level of p74 expression. These transformants
could be rescued by overexpression of the alpha-subunit of wild-type eukaryotic
translation initiation factor 2 (eIF2alpha), one of the known substrates for PKR.
We hypothesize that competing heterodimers between p74-K296R PKR and eIF2alpha
K296R PKR may control cell growth such that stabilization of the p74-K296R PKR
heterodimer induces abnormal morphology and cell death.
PMID- 10684937
TI - Determination of L1 retrotransposition kinetics in cultured cells.
AB - L1 retrotransposons are autonomous retroelements that are active in the human and
mouse genomes. Previously, we developed a cultured cell assay that uses a
neomycin phosphotransferase ( neo ) retrotransposition cassette to determine
relative retrotransposition frequencies among various L1 elements. Here, we
describe a new retrotransposition assay that uses an enhanced green fluorescent
protein (EGFP) retrotransposition cassette to determine retrotransposition
kinetics in cultured cells. We show that retrotransposition is not detected in
cultured cells during the first 48 h post-transfection, but then proceeds at a
continuous high rate for at least 16 days. We also determine the relative
retrotransposition rates of two similar human L1 retrotransposons, L1(RP)and
L1.3. L1(RP)retrotransposed in the EGFP assay at a rate of approximately 0.5% of
transfected cells/day, approximately 3-fold higher than the rate measured for
L1.3. We conclude that the new assay detects near real time retrotransposition in
a single cell and is sufficiently sensitive to differentiate retrotransposition
rates among similar L1 elements. The EGFP assay exhibits improved speed and
accuracy compared to the previous assay when used to determine relative
retrotransposition frequencies. Furthermore, the EGFP cassette has an expanded
range of experimental applications.
PMID- 10684938
TI - Requirement for PCNA and RPA in interstrand crosslink-induced DNA synthesis.
AB - Proliferating nuclear cell antigen (PCNA) and replication protein A (RPA) have
proven to be essential elements in many aspects of DNA metabolism including
replication, repair and recombination. We have developed an in vitro assay in
which the presence of an interstrand crosslink stimulates the incorporation of
radiolabeled nucleotides into both damaged and undamaged plasmid DNAs. Using this
assay we have investigated the roles of PCNA and RPA in crosslink-induced DNA
synthesis. p21, a potent inhibitor of PCNA, was found to strongly inhibit
crosslink-induced incorporation. Addition of exogenous PCNA partially restored
the resynthesis activity. Likewise, neutralization of RPA by monoclonal
antibodies also inhibited incorporation, but the effect was somewhat more
pronounced on the undamaged plasmid than the damaged plasmid. Addition of excess
RPA also partially reversed antibody inhibition. These results indicate that both
PCNA and RPA are required for efficient in vitro DNA resynthesis induced by
interstrand crosslinks.
PMID- 10684939
TI - Functional alpha-fragment of beta-galactosidase can be expressed from the mobile
group I intron PpLSU3 embedded in yeast pre-ribosomal RNA derived from the
chromosomal rDNA locus.
AB - PpLSU3, a mobile group I intron found in the ribo-somal RNA genes of Physarum
polycephalum, encodes the I-PpoI homing endonuclease. This enzyme represents one
of the rare cases in nature where a protein is expressed from an RNA polymerase I
transcript. Our previous results showed that the full length intron, but not a
further processed species, is the messenger for I-PpoI, implying a role of the
untranslated region (UTR) in gene expression. To study the function of the 3'-UTR
in expression of the endonuclease and in splicing of the intron, we replaced the
I-PpoI gene in PpLSU3 with the gene for the alpha-fragment of Escherichia coli
beta-galactosidase, and then integrated this chimeric intron into all the
chromosomal rDNA repeats of yeast. The resulting cells synthesized functional
alpha-fragment, as evidenced by a complementation assay analogous to that used in
E.coli. The beta-galactosidase activity thus provides an unusual and potentially
valuable readout for Pol I transcription from chromosomal rDNA. This is the first
example in which a eucaryotic homing endonuclease gene has been successfully
replaced by a heterologous gene. Using deletion mutagenesis and a novel
randomization approach with the alpha-fragment as a reporter, we found that a
small segment of the 3'-UTR dramatically influences both splicing and protein
expression.
PMID- 10684940
TI - The initiator element of the Drosophila beta2 tubulin gene core promoter
contributes to gene expression in vivo but is not required for male germ-cell
specific expression.
AB - The tissue-specific expression of the Drosophila beta 2 tubulin gene ( B2t ) is
accomplished by the action of a 14-bp activator element (beta2UE1) in combination
with certain regulatory elements of the TATA-less, Inr-containing B2t core
promoter. We performed an in vivo analysis of the Inr element function in the B2t
core promoter using a transgenic approach. Our experiments demonstrate that the
Inr element acts as a functional cis -regulatory element in vivo and
quantitatively regulates tissue-specific reporter expression in transgenic
animals. However, our mutational analysis of the Inr element demonstrates no
essential role of the Inr in mediating tissue specificity of the B2t promoter. In
addition, a downstream element seems to affect promoter activity in combination
with the Inr. In summary, our data show for the first time the functionality of
the Inr element in an in vivo background situation in Drosophila.
PMID- 10684941
TI - Ligation reaction specificities of an NAD(+)-dependent DNA ligase from the
hyperthermophile Aquifex aeolicus.
AB - An NAD(+)-dependent DNA ligase from the hyperthermophilic bacterium Aquifex
aeolicus was cloned, expressed in Escherichia coli and purified to homogeneity.
The enzyme is most active in slightly alkaline pH conditions with either Mg(2+)or
Mn(2+)as the metal cofactor. Ca(2+)and Ni(2+)mainly support formation of DNA
adenylate intermediates. The catalytic cycle is characterized by a low k
(cat)value of 2 min(-1)with concomitant accumulation of the DNA - adenylate
intermediate when Mg(2+)is used as the metal cofactor. The ligation rates of
matched substrates vary by up to 4-fold, but exhibit a general trend of T/A < or
= G/C < C/G < A/T on both the 3'- and 5'-side of the nick. Consistent with
previous studies on Thermus ligases, this Aquifex ligase exhibits greater
discrimination against a mismatched base pair on the 3'-side of the nick
junction. The requirement of 3' complementarity for a ligation reaction is
reaffirmed by results from 1 nt insertions on either the 3'- or 5'-side of the
nick. Furthermore, most of the unligatable 3' mismatched base pairs prohibit
formation of the DNA-adenylate intermediate, indicating that the substrate
adenylation step is also a control point for ligation fidelity. Unlike previously
studied ATP ligases, gapped substrates cannot be ligated and intermediate
accumulation is minimal, suggesting that complete elimination of base pair
complementarity on one side of the nick affects substrate adenylation on the 5'
side of the nick junction. Relationships among metal cofactors, ligation products
and intermediate, and ligation fidelity are discussed.
PMID- 10684942
TI - Pre-selection of integration sites imparts repeatable transgene expression.
AB - Variable gene expression amongst transgenic lines occurs due to copy number and
to random associations of incoming DNA with chromosomal elements at the site of
integration. Here we describe a method of identifying sites permissive for
transgene expression and their use for efficient introduction of single copy
transgenes by homologous recombination. ES clones were selected in HAT medium for
expression of a randomly integrated HPRT marker lying 5' to an Oct4/ lacZ
transgene. 794 clones were assessed in vitro for appropriate down-regulation of
lacZ following differentiation. Two clones were chosen for further analysis which
displayed appropriate and inappropriate gene regulation (clones 710 and 91,
respectively). Three developmental promoters (thyroglobulin, Hox2.6 and Myf5)
were then sequentially introduced into the original insertion sites in each clone
(710 and 91) by homologous recombination, to drive expression of lacZ. Transgenic
embryos were assessed for their ability to direct lacZ expression to tissues in
which the respective promoter sequences are normally active. The site which
appropriately down-regulated lacZ in vitro (710) also showed appropriate in vivo
regulation of lacZ from the three developmental promoters. Site 91, however,
directed an additional pattern of ectopic expression, which was common to all
four promoters. Pre-selection of genomic sites for the introduction of transgenes
by gene targeting improves the repeatability of transgene expression and provides
an efficient means of single copy transgene introduction by homologous
recombination.
PMID- 10684943
TI - A developmentally regulated deletion element with long terminal repeats has cis
acting sequences in the flanking DNA.
AB - Approximately 6000 specific DNA deletion events occur during development of the
somatic macro-nucleus of the ciliate Tetrahymena. The eliminated Tlr1 element is
13 kb or more in length and has an 825 bp inverted repeat near the rearrangement
junctions. A functional analysis of the cis -acting sequences required for Tlr1
rearrangement was performed. A construct consisting of the entire inverted repeat
and several hundred base pairs of flanking DNA on each side was rearranged
accurately in vivo and displayed junctional variability similar to the
chromosomal Tlr1 rearrangement. Thus, 11 kb or more of internal element DNA is
not required in cis for DNA rearrangement. A second construct with only 51 bp of
Tetra-hymena DNA flanking the right junction underwent aberrant rearrangement.
Thus, a signal for determination of the Tlr1 junction is located in the flanking
DNA, 51 bp or more from the right junction. Within the Tlr1 inverted repeat are
19 bp tandem repeats. A construct with the 19mer repeat region deleted from the
right half of the inverted repeat utilized normal rearrangement junctions. Thus,
despite its transposon-like structure, Tlr1 is similar to other DNA
rearrangements in Tetrahymena in possessing cis -acting sequences outside the
deleted DNA.
PMID- 10684944
TI - Cloning and characterisation of the Sry-related transcription factor gene Sox8.
AB - SOX proteins form a large family of transcription factors related by a DNA
binding domain known as the HMG box. Some 30 Sox genes have been identified in
mammals and orthologues have been found in a wide range of other metazoans. Sox
genes are highly conserved and are known to play important roles in embryonic
development, including roles in gonadal, central nervous system, neural crest and
skeletal development. Several SOX genes have been implicated in human congenital
diseases. We report here the isolation of Sox8 and its characterisation in mice
and humans. This gene has a remarkably similar primary structure and genomic
organisation to the campomelic dysplasia gene SOX9 and the Waardenburg-Shah
syndrome gene SOX10. SOX8 protein is able to bind to canonical SOX target DNA
sequences and activate transcription in vitro through two separate trans
activation regions. Further, Sox8 is expressed in the central nervous system,
limbs, kidneys, gonads and craniofacial structures during mouse embryo
development. Sox8 maps to the t complex on mouse chromosome 17 and to human
chromosome 16p13.3, a region associated with the microphthalmia-cataract syndrome
CATM and the alpha-thalassemia/mental retardation syndrome ATR-16.
PMID- 10684945
TI - Analysis of the yeast transcriptome with structural and functional categories:
characterizing highly expressed proteins.
AB - We analyzed 10 genome expression data sets by large-scale cross-referencing
against broad structural and functional categories. The data sets, generated by
different techniques (e.g. SAGE and gene chips), provide various representations
of the yeast transcriptome (the set of all yeast genes, weighted by transcript
abundance). Our analysis enabled us to determine features more prevalent in the
transcriptome than the genome: i.e. those that are common to highly expressed
proteins. Starting with simplest categories, we find that, relative to the
genome, the transcriptome is enriched in Ala and Gly and depleted in Asn and very
long proteins. We find, furthermore, that protein length and maximum expression
level have a roughly inverse relationship. To relate expression level and protein
structure, we assigned transmembrane helices and known folds (using PSI-blast) to
each protein in the genome; this allowed us to determine that the transcriptome
is enriched in mixed alpha-beta structures and depleted in membrane proteins
relative to the genome. In particular, some enzymatic folds, such as the TIM
barrel and the G3P dehydrogenase fold, are much more prevalent in the
transcriptome than the genome, whereas others, such as the protein-kinase and
leucine-zipper folds, are depleted. The TIM barrel, in fact, is overwhelmingly
the 'top fold' in the transcriptome, while it only ranks fifth in the genome. The
most highly enriched functional categories in the transcriptome (based on the
MIPS system) are energy production and protein synthesis, while categories such
as transcription, transport and signaling are depleted. Furthermore, for a given
functional category, transcriptome enrichment varies quite substantially between
the different expression data sets, with a variation an order of magnitude larger
than for the other categories cross-referenced (e.g. amino acids). One can
readily see how the enrichment and depletion of the various functional categories
relates directly to that of particular folds.
PMID- 10684946
TI - Species-specific regulation of alternative splicing in the C-terminal region of
the p53 tumor suppressor gene.
AB - Alternative splicing occurs in the C-terminal region of the p53 tumor suppressor
gene between two alternative 3' splice sites in intron 10. This alternative
splicing event has been detected in murine cells, but not in rat or human
tissues. In this paper, we have characterized the pattern of p53 alternative
splicing in cell lines from five different species. Our results confirm that p53
alternative splicing is species-specific, being detected only in cell lines of
rodent origin. Using transient transfection assays, we have established that the
rat p53 gene undergoes efficient alternative splicing in both mouse and rat cell
lines, thus demonstrating that it has all the necessary cis -acting sequences to
be alternatively spliced. In contrast, we were unable to detect any usage of the
human alternative 3' splice site under the same experimental conditions. Thus,
the low levels or absence of alternatively spliced p53 mRNA in rat and human cell
lines seems to be the result of different mechanisms. Our results support the
hypothesis that there are species-specific mechanisms implicated in the
regulation of p53 activity.
PMID- 10684947
TI - A rapid genetic screening system for identifying gene-specific suppression
constructs for use in human cells.
AB - We describe a rapid cell-based genetic screen using fission yeast for identifying
efficient gene suppression constructs (GSCs) from large libraries (10(5)) for any
target sequence for use in human cells. In this system, target sequences are
fused to the 5' end of the lacZ reporter gene and expressed in yeast. Random
fragment expression libraries derived from the target sequence are screened in
the fusion gene-expressing strain using the lacZ gene-encoded colony color
phenotype. We demonstrate the utility of this screening assay by identifying a
range of different GSCs for the fission yeast ura4 gene and human c-myc and Chk1
sequences, including rare efficient suppressors. GSCs specific for c-myc were
shown to regulate expression of both a c-myc-lacZ fusion gene and the endogenous
c-myc gene in human cells.
PMID- 10684949
TI - Editorial
PMID- 10684948
TI - Endogenous oxidative DNA base modifications analysed with repair enzymes and
GC/MS technique.
AB - GC/MS technique was used to identify endogenous levels of oxidatively modified
DNA bases. To avoid possible artefact formation we used Fpg and Endo III
endonucleases instead of acid hydrolysis to liberate the base products from
unmodified DNA samples. Several different DNA preparations were used: (i)
commercial calf thymus DNA, (ii) DNA isolated from rat liver, (iii) DNA isolated
from human lymphocytes and (iv) nuclei isolated from rat liver. In all DNA
samples used in our assays the most efficiently removed bases by Fpg protein are
FapyG and FapyA although 8-oxoG was also detected in all preparations. The amount
of 8-oxoG in human lymphocytes and in rat liver DNA was 3 and 2 per 10(7)bases,
respectively. It is reasonable to postulate that the presented method is one of
the techniques which should be used to reveal the enigma of endogenous, oxidative
DNA damage.
PMID- 10684950
TI - Stress, burnout and locus of control in German nurses.
AB - The aim of this study was to evaluate the effects of locus of control and work
related stress on burnout in hospital staff nurses. A convenience sample of 361
staff nurses from nine units in five German hospitals were surveyed using the
Maslach Burnout Inventory, the Locus of Control Questionnaire and a Work-Related
Stress Inventory. Causal modeling was used to explore the moderating effect of
locus of control on burnout. Results support the hypothesized model and suggest
that greater work-related stress and burnout would be associated with poorer
locus of control in nurses. The findings supported the notion that perceived
degree of control is instrumental in enabling nurses to cope with stress and
burnout.
PMID- 10684951
TI - Frequency of intravenous medication administration to hospitalised patients:
secondary data-analysis of the Belgian nursing minimum data set.
AB - The purpose of this study was to investigate the frequency of intravenous
medication administration with Belgian hospitalised patients. Factors, which
might influence this frequency of administration, were also studied. Research
questions were investigated by secondary data-analysis of the Belgian Nursing
Minimum Data Set. The randomised sample consisted of 1,035,681 observations on
421,530 patients. Results of this study demonstrate that one out of three (34%)
hospitalised patients received intravenous medication. Medical diagnoses, for
which most intravenous medications were administered, were oncological diseases:
myeloid (77.9%) and lymphoid (69.4%) leukaemia. Elderly (6.7%) and female (31.2%)
patients received significantly less intravenous medication than respectively
young (32.9%) (chi(2) = 98411, df = 1, p<0.001) and male (38%) (chi(2) = 2033, df
= 1, p<0.001) patients. Patients with intravenous medication administration were
labour intensive for nursing staff.
PMID- 10684952
TI - Living a restricted life with Ehlers-Danlos syndrome (EDS).
AB - Ehlers-Danlos syndrome (EDS) is an inherited connective tissue disorder,
primarily affecting the skin, ligaments, joints and blood vessels. The symptoms
can vary from undiagnosed cases with mild symptoms to more severe forms. A
qualitative study was conducted with the purpose of exploring how individuals
with different symptoms of EDS describe their symptoms and perceive their daily
life. Eleven interviewees were recruited via a support group in Sweden. The main
strategies of the grounded theory method were used in collection and analysis of
data. The identified main theme, "Living a restricted life", seemed to explain
the way in which fears, pain, stigmatisation and experiences of non-affirmation
in health-care limited the possibility of self-actualisation in daily living and
social life. This study provides a conceptual framework for future research and
an understanding of the type of professional support individuals with EDS
require.
PMID- 10684953
TI - Exercise participation decisions of Jordanian myocardial infarction patients:
application of the decisional conflict theory.
AB - This study examined the utility of Janis and Mann's [Janis, I. L. & Mann, L.
(1977). Decision making: a psychological analysis conflict, choice and
commitment. New York, NY: Free press.] decisional conflict theory (DCT) in
predicting decisions to exercise following hospitalization for a myocardial
infarction (MI). A structured interview of operationalized DCT variables was
conducted with 88 MI patients attending cardiology clinics in two Jordanian
military hospitals. Stress was viewed as an indicator of exercise benefits
barriers decisional conflict. The findings revealed that the benefits-barriers
interaction significantly predicted stress for the 48 patients who did not
exercise. Rehospitalization for cardiac events was a significant predictor of
stress for the 40 exercisers. Preinfarction exercise behavior, stress and gender
were significant predictors of MI patients' decisions to exercise. Results of
this study indicated that decisional conflict and stress were characteristics of
MI patients who delayed or avoided exercising.
PMID- 10684954
TI - Measurement of fatigue in chronic obstructive pulmonary disease and in asthma.
AB - Despite recognition of a high prevalence of fatigue in individuals with chronic
airflow obstruction conditions, including chronic obstructive pulmonary disease
and asthma, and its importance from a quality of life perspective, no research
was found in which fatigue was measured directly in these populations. This may
be due to a seeming lack of appropriate instruments for measuring fatigue in
these populations. The purpose of this study, therefore, was to pretest an
instrument, the Piper Fatigue Scale, which was developed to measure chronic
fatigue in clinical populations. The outpatient sample consisted of 17 persons
with chronic obstructive pulmonary disease and 19 with asthma. Findings revealed
that the visual analogue scale version of the Piper Fatigue Scale may not be
appropriate for measuring fatigue in these populations. Instruments with validity
and reliability for fatigue in chronic obstructive pulmonary disease and asthma
need to be developed.
PMID- 10684955
TI - Problem-solving skills of senior student nurses: an exploratory study using
simulation.
AB - The Stages Model of problem-solving as evidenced in the use of the nursing
process is the key vehicle for the operationalisation of problem-solving in
current nursing practice. An expanded variant of the model formed the theoretical
framework for this study which aimed to explore and compare the problem-solving
skills of senior student nurses (n=253) from three pre-registration nurse
education programmes (RGN, diploma RN, integrated degree). Students' care
planning skills were explored using a video-tape simulation exercise and data
were subjected to statistical testing. Findings indicated a large range in the
global care plan scores and while performance was similar in a number of areas
independent of programme type, certain key differences also emerged. The findings
are discussed in the wider context of professional education and practice and the
potential for further development of problem-solving skills in pre-registration
nurse education is explored.
PMID- 10684956
TI - The art and science of predicting patient readiness for weaning from mechanical
ventilation.
AB - Weaning from mechanical ventilation is attempted when the patient's underlying
condition has resolved and when the patient is able to maintain cardiovascular
and respiratory stability within normal parameters. From a medical perspective,
when to wean is based on patient readiness determined by objective, physiological
criteria. Psychological readiness is equally important, yet criteria determining
psychological readiness is generally omitted from the list of ready to wean
parameters. Reasons for this may be that psychological readiness is difficult to
measure and is based upon subjective opinions. Nursing research exploring
critical care nurses' and patients' experiences of weaning has extended knowledge
concerning patients' psychological readiness to wean. From examination of this
research, three important criteria emerge. It is recommended that the addition of
these criteria to the list of physiological criteria will not only achieve a
holistic assessment of patients' readiness to wean, but will also acknowledge the
important and complementary role of the nurse in the weaning process.
PMID- 10684957
TI - The effectiveness of intermediate care in a nursing-led in-patient unit.
AB - In order to assess the potential for a nursing-led in-patient unit (NLIU) to
substitute for a period of care in the acute hospital environment and promote
recovery before discharge, a randomised controlled trial was conducted. The
setting was an acute inner London hospital trust, part of the UK's national
health service. Of patients referred to a NLIU from acute wards, 80 were randomly
assigned to usual care (remain in normal hospital system) and 97 to the NLIU
(nursing-led care with no routine medical involvement). Patients were identified
as medically stable but in need of additional nursing intervention by referring
medical staff prior to full nursing assessment of suitability. Outcomes compared
included functional dependence (Barthel Index), discharge destination and length
of hospital stay. Inputs from nursing, paramedical and medical staff were
measured. There was no significant difference in functional independence at
discharge (p0.05). Patients undergoing usual care stayed in hospital for less
time (mean difference 18 days, p<0.01) but the same number of patients were in
hospital 90 days after recruitment (23% NLIU, 24% usual care p0.05) due to re
admissions. The model of care implemented differed considerably from that
described in the literature with the NLIU having significantly fewer qualified
nurses (RNs). Although the anticipated benefits of the NLIU were not
demonstrated, the study does not conclude that the model should be rejected.
Factors driving length of stay need to be further investigated, as does the
possibility of post-discharge benefits. The NLIU does offer some potential to
substitute for acute care but also appears to substitute for a period of primary
care.
PMID- 10684958
TI - Effects of hospital restructuring on full time and part time nursing staff in
Ontario.
AB - This study examined the effects of hospital restructuring and downsizing on full
time and part-time nursing staff. Data were collected from 1362 nursing staff, a
35% response rate, using anonymous questionnaires. Measures included personal and
situational characteristics, hospital restructuring and downsizing variables,
work outcomes and psychological well-being indicators, and work-family
experiences. Although full and part-time nurses were significantly different on
most personal and demographic characteristics, both groups experienced and
described hospital restructuring and downsizing similarly. Full-time nurses
reported greater emotional exhaustion and poorer health and indicated greater
absenteeism and lower intention to quit.
PMID- 10684959
TI - Why nurses smoke: a review of the literature.
AB - The smoking behaviour of nurses has been widely debated in the context of their
professional role and responsibilities. There has been much speculation about why
nurses smoke and possible explanations include a stressful nursing environment,
peer pressure and socio economic status and education. This paper provides an
overview of the literature which offers insights into the reasons why nurses
smoke and compares the findings from this literature with those studies examining
the smoking behaviour of women in general and young women in particular. This
review reveals that many students take up smoking before commencing their
training and the factors which influence nurses smoking are similar to those that
influence similar groups of females in the general population.
PMID- 10684960
TI - Requirement of MEF2D in the induced differentiation of HL60 promyeloid cells.
AB - The regulatory role of MEF2 (myocyte enhancer binding factor 2) proteins in
nonmuscle tissues has not been well characterized. We examined the expression of
MEF2 family members, namely, MEF2A, -B, -C, and -D, in the differentiation of
HL60 promyeloid cells and observed the remarkable increase in the expressions of
MEF2A and MEF2D proteins during the differentiation process into monocytes. To
examine the role of MEF2, we expressed a dominant-negative form of MEF2D, without
its transactivation domain, in HL60 cells. When the HL60 cell line expressing the
mutant MEF2D was induced to differentiate by VitD(3) treatment, cell surface
expression of CD14 and the ability to reduce NBT, which are important
characteristics of differentiated monocytes, were significantly decreased
compared with control HL60 cells. These results show that MEF2D is required in
the differentiation process along the monocyte/macrophage lineage,
PMID- 10684961
TI - Innate antibody catalysis.
AB - Catalysis by antibodies is often assumed to require immunization with artificial
haptens, which are proposed to stimulate adaptive immune processes and enable the
development of catalytic sites with the ability to bind the transition state.
Contrary to this assumption, we describe here a serine protease-like catalytic
triad in an antibody light chain raised by immunization with vasoactive
intestinal peptide (VIP), the structure and function of which is inherited via a
germline V(L) gene. The serine protease mechanism was evident from loss of the
catalytic activity by site directed mutagenesis at a framework region residue
Asp1 (present study) and at two complementarity determining region residues
Ser27a and His 93 (Gao, Q-S., Sun, M., Rees, A., Paul, S., 1995. Site-directed
mutagenesis of proteolytic antibody light chain. J. Mol. Biol. 253, 658-664). All
three catalytic residues (Ser27a, His93, Asp1) are also present in the germline
counterpart of the mature V(L) gene, but the mature and germline sequences differ
by four amino acids remote from the catalytic site. Reversion mutations were
introduced at these amino acids in the mature light chain (His27 d:Asp,
Thr28e:Ser, Ile34:Asn, Gln96:Trp; Kabat numbering, germline encoded residues
shown second), generating the germline configuration of the protein. The germline
light chain expressed peptidase activity, determined by assaying the cleavage of
VIP and a synthetic protease substrate, Pro-Phe-Arg-Methylcoumarinamide.
Differences between the kinetic constants for the mature and germline light
chains were marginal. Diisopropylfluorophosphate, a serine protease inhibitor,
blocked the peptidase activity of the germline light chain, suggesting the
presence of the catalytic triad in a functional state. Like the mature light
chain, the germline protein preferentially cleaves peptide bonds on the C
terminal side of basic residues. We conclude that the catalytic activity of
certain antibodies is an innate function, originating over the course of
phylogenetic evolution of the V(L) genes, as opposed to somatic processes.
PMID- 10684962
TI - Characterization of novel FcepsilonRII/CD23 isoforms lacking the transmembrane
(TM) segment in human cell lines.
AB - Human FcepsilonRII/CD23 is an approximately 45 kDa type II transmembrane
glycoprotein belonging to the C-type animal-lectin family, and has two isoforms
(a and b) that only differ in their intracytoplasmic tails. We previously found
that in several human and mouse cell lines there were two additional CD23
transcripts (a' and b') lacking the exon 3 that encodes the entire transmembrane
segment and a part of cytoplasmic tails. In this study, we analyzed the putative
CD23a' and CD23b' products at protein levels and characterized with rabbit
polyclonal antibodies against novel amino-acid sequences of the putative CD23a'
and CD23b' molecules (anti-CD23a' Ab, anti-CD23b' Ab). Western blots in COS cells
transfected with CD23a' or CD23b' cDNA as well as in vitro translation assays
showed that the a' and b' CD23 transcripts were translated to about 40 kDa
molecules. These 40 kDa molecules were also recognized by a polyclonal antibody
against 25 kDa soluble fragment of human CD23. We also found that human cells
having mRNAs for CD23a' and CD23b' expressed protein products recognized
specifically by anti-CD23a' or anti-CD23b' Ab, respectively. In addition, the
CD23a' and CD23b' molecules in transfected COS cells were resistant to Endo H(f)
and PNGase F, although these truncated forms as well as the membrane-associated
forms had an asparagine residue responsible for the N-linked glycosylation. Taken
together, our results show that the a' and b' CD23 transcripts are expressed and
translated in human lymphoid cells and that their translated products are
retained in the cytoplasm where they might play an unique regulatory role in the
expression of the full-length CD23 on the cell surface.
PMID- 10684963
TI - Selection of phage-displayed anti-guinea pig C5 or C5a antibodies and their
application in xenotransplantation.
AB - Xenogeneic liver transplantation in the discordant guinea pig (gp) to rat model
results in hyperacute rejection within a few minutes, which is due to activation
of the complement system. Currently no antibodies against gp complement factors
are available, which allow activation of the gp complement system in serum or
complement deposition in tissue to be detected. To close this gap, we started
developing single chain Fvs (scFvs) against gpC5 and gpC5a. We generated a
combinatorial library of scFv antibodies comprising the variable heavy and light
chain repertoire from mice immunized with gpC5. Out of this library we selected
several antibodies against gpC5 and C5a after four and six rounds of biopanning,
respectively. Selected gpC5-specific scFvs were purified by metal affinity
chromatography followed by size exclusion chromatography or by affinity
chromatography using Protein L. Purified scFvs were able to inhibit gp complement
system in a hemolytic assay and to detect gpC5 deposition in tissue. A surface
plasmon resonance based assay on BIAcore was established, with which the C5
concentration in gp serum was determined to 240 microg/ml. As at least 0.04% of
the normal gpC5 concentration can be detected, the test provides a powerful tool
to investigate the development and the consequence of a hybrid complement system
after liver xenotransplantation from gp to rat.
PMID- 10684964
TI - Inhibition of M-tropic HIV-1 infection by the fd phage-gene 3 protein with MIP
1alpha-binding activity.
AB - CCR5 is a chemokine receptor with seven transmembrane-domains. It is expressed on
T cells and macrophages and functions as the principal co-receptor for macrophage
(M)-tropic strains of HIV-1. The anti-CCR5 monoclonal antibody (mAb) 2D7 inhibits
the binding and chemotaxis of the three natural beta-chemokine ligands of CCR5,
macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES, to CCR5(+)
cells. The mAb also efficiently blocks the infectivity of several M-tropic and
dual-tropic HIV-1 strains in vitro. In this study, we attempted to determine the
peptide motif recognized with the 2D7 mAb. We isolated phage clones by panning a
phage display library using 2D7 and identified three peptide motifs. One of these
phage clones (M23) showed a marked inhibitory activity on HIV-1 infection. The
unique sequence of 15 amino acids with an internal disulfide bond was inserted in
the g3p of the M23 phage clone (M23-g3p). The M23-g3p was purified by fast
performance liquid chromatography (FPLC). We show here that (1) M23-g3p was
specifically recognized with anti-CCR5 mAb; (2) M23-g3p showed inhibitory
activity on the infectivity of M-tropic but not T-tropic HIV-1 strains; (3) M23
g3p bound to MIP-1alpha, MIP-1beta, and RANTES but not MCP-1. These results
suggested that the M23-g3p might mimic the CCR5-binding domain shared by beta
chemokines, MIP-1alpha, MIP-1beta, and RANTES as well as the HIV-1 infection.
PMID- 10684965
TI - Molecular cloning of the brushtail possum (Trichosurus vulpecula) immunglobulin E
heavy chain constant region.
AB - The immunobiology of marsupial IgE is poorly understood. As a first step towards
the development of immunological reagents for marsupials and to obtain a further
understanding of immunoglobulin evolution, a brushtail possum (Trichosurus
vulpecula) mesenteric lymph node cDNA library was screened for the heavy chain
constant region of IgE (Cepsilon), using a partial Cepsilon probe from the
American marsupial, Monodelphis domestica. The cDNA sequence for T. vulpecula
Cepsilon was determined and found to be most similar to the M. domestica Cepsilon
sequence [(76%) at the amino acid level]. T. vulpecula Cepsilon has amino acid
sequence similarities ranging from 43-52% with various eutherian Cepsilon
sequences. The secondary structure of T. vulpecula Cepsilon, based on loops
formed by internal disulfide bonds, more closely resembles rodent Cepsilon than
the American marsupial sequence.
PMID- 10684966
TI - V(D)J recombination catalyzed by mutant RAG proteins lacking consensus DNA-PK
phosphorylation sites.
AB - The process of antigen receptor gene rearrangement, V(D)J recombination, involves
DNA cleavage by the RAG-1 and RAG-2 proteins. Cleavage generates covalently
sealed (hairpin) DNA ends, termed coding ends, which must be opened by an
endonuclease prior to joining. Resolution of these hairpin ends requires the
activity of the DNA-dependent protein kinase (DNA-PK), a protein kinase whose
specific role is yet undetermined. It has been suggested that phosphorylation of
one or both RAG proteins by DNA-PK is required to activate or recruit the hairpin
opening nuclease. Furthermore, very recent work has shown that RAG proteins
themselves can open hairpins. These data raise the possibility that DNA-PK
mediated phosphorylation of the RAG proteins could regulate the hairpin opening
reaction. To test this hypothesis, we constructed mutant versions of RAG-1 and
RAG-2 in which all four DNA-PK consensus phosphorylation sites were removed by
site-directed mutagenesis. Our data provide conclusive evidence that
phosphorylation of these conserved serine/threonine residues is not required for
hairpin opening or joining of V(D)J recombination intermediates.
PMID- 10684967
TI - A novel DNA element mediates transcription of Nkx2.1 by Sp1 and Sp3 in pulmonary
epithelial cells.
AB - NKX2.1 is a member of the NK2 family of homeodomain-containing transcription
factors whose targeted disruption in mouse results in the absence of thyroid
tissue and a severely abnormal lung phenotype. Little is known regarding the
mechanisms that control tissue and temporal specificity of Nkx2.1 gene
expression. The Nkx2.1 gene has been cloned from a number of species and it is
composed of three exons and two introns. Two distinct DNA domains located 5' of
exon I and within intron I have been found to exhibit promoter activity in lung
and thyroid cells. In the current study we used deletional analysis of the 5'
flanking region of exon I and identified a 300 bp TATA-less region that exhibits
significant promoter activity in H441 cells. The DNA sequence of this region
contains multiple palindromes, composed of G/C-rich elements. DNase I
footprinting demonstrates that this promoter region interacts with nuclear
factors present in H441 cells. In particular electrophoretic mobility shift assay
using antibodies against the Sp family members show that both Sp1 and Sp3 as well
as an as yet unknown H441-specific factor interact with the palindromic structure
within this promoter region. Co-transfection studies show that this promoter
region responds to Sp1 and Sp3 and mutations therein result in a significantly
diminished response to these transcriptional factors. Therefore, we have
identified a novel DNA structure on the Nkx2.1 gene which participates in
transcription of this gene in pulmonary epithelial cells by Sp1 and Sp3
transcription factors.
PMID- 10684968
TI - The intron-containing L3 ribosomal protein gene (RPL3): sequence analysis and
identification of U43 and of two novel intronic small nucleolar RNAs.
AB - Isolation and sequencing of bovine and human intron-containing L3 ribosomal
protein genes are here reported. They exhibit very similar organisation, both
comprising 10 exons and nine introns. A polymorphic locus, involving a 19-bp
deletion, was found in intron 6 of the human gene. The frequency of the two
alleles has been estimated in 200 haploid genomes. In bovine and human genes
intron sequences are rather different, except for limited regions, located in
corresponding positions, which show a surprisingly high degree of identity. All
these regions contain conserved features defining the box C/D class of small
nucleolar RNAs. Demonstration is given that U43 small nucleolar RNA is encoded
within the first intron of both bovine and human genes. Single nucleotide
sequences, encoding two novel species of small nucleolar RNAs (U82, U83a and
U83b), are located in introns 3, 5 and 7. Their expression has been investigated
and a possible role of these molecules in 2'-O-ribose methylation of rRNAs is
discussed.
PMID- 10684969
TI - Molecular characterization of ubiquitin genes from Aspergillus nidulans: mRNA
expression on different stress and growth conditions.
AB - We are interested in studying the ubiquitin (UBI) gene expression during
different stress and growth conditions in the filamentous fungus Aspergillus
nidulans. Here, we report the cloning of a cDNA clone that corresponds to a gene,
ubi1, that encodes a carboxyl extension protein from A. nidulans. This cDNA
corresponds to a gene that encodes a protein that showed high homology to other
polyubiquitin and CEP-80 genes at the N- and C-terminus, respectively. We
characterize the mRNA expression of the CEP and polyubiquitin genes during
several growth and stress conditions. Expression of the ubi1 and ubi4 genes was
correlated with cell growth in most of the carbon sources used, except maltose.
Both ubi1 and ubi4 genes were induced upon heat-shock, although the levels of
expression were raised quicker for ubi4 than for ubi1. The ubi1 and ubi4 genes
displayed a very complex expression pattern in presence of drugs with a different
mechanism of action suggesting that the regulatory processes controlling UBI gene
expression discriminate between different stresses and can affect individually
each UBI gene. The ubi1 gene was highly expressed in presence of hydrogen
peroxide while the ubi4 mRNA level was not affected; several metals in our
experimental conditions were not able to induce either ubi1 nor ubi4 genes.
PMID- 10684970
TI - Expression and characterization of the human mitochondrial leucyl-tRNA
synthetase.
AB - A cDNA clone encoding the human mitochondrial leucyl-tRNA synthetase (mtLeuRS)
has been identified from the EST databases. Analysis of the protein encoded by
this cDNA indicates that the protein is 903 amino acids in length and contains a
mitochondrial signal sequence that is predicted to encompass the first 21 amino
acids. Sequence analysis shows that this protein contains the characteristic
motifs of class I aminoacyl-tRNA synthetases and regions of high homology to
other mitochondrial and bacterial LeuRS proteins. The mature form of this protein
has been cloned and expressed in Escherichia coli. Gel filtration indicates that
human mtLeuRS is active in a monomeric state, with an apparent molecular mass of
101 kDa. The human mtLeuRS is capable of aminoacylating E. coli tRNA(Leu). Its
activity is inhibited at high levels of either monovalent or divalent cations.
K(M) and k(cat) values for ATP:PP(i) exchange and for the aminoacylation reaction
have been determined.
PMID- 10684971
TI - Transforming growth factor beta inhibitory element in the rabbit matrix
metalloproteinase-1 (collagenase-1) gene functions as a repressor of constitutive
transcription.
AB - Transforming growth factor beta (TGF-beta) is a potent modulator of the
extracellular matrix, enhancing collagen synthesis and regulating expression of
several genes that encode the matrix metalloproteinases (MMPs), enzymes that
degrade the extracellular matrix. In this study, we explored the mechanisms
whereby TGF-beta inhibits expression of the MMP-1 (collagenase 1) gene. We used
transient transfection and gel mobility shift assays to characterize a TGF beta
inhibitory element (TIE) at -249 bp in the rabbit MMP-1 promoter, which is also
conserved at -246 bp in the human gene. This sequence shares homology to a
previously identified TIE in the rat stromelysin-1 (MMP-3) promoter, where it is
located at -709 bp. Mutational analyses and transient transfections indicate that
MMP-1 TIE functions both as a constitutive repressor of MMP-1 gene expression
and, in the presence of TGF-beta, as an antagonist of transcriptional induction
by phorbol esters. c-Fos binds to the TIE in the rabbit MMP-1 promoter, along
with other nuclear proteins, even in the absence of treatment with TGF-beta.
However, the pattern of proteins binding to the TIE is altered in the presence of
nuclear extracts from TGF-beta-treated cells, suggesting that TGF-beta leads to
an alteration in protein/DNA interaction, with subsequent modulation of MMP-1
gene expression. We conclude that in the rabbit MMP-1 promoter, the TIE has dual
functions as a repressor of basal transcription and as a mediator of the biologic
effects of TGF-beta. Furthermore, these dual functions provide additional and
subtle mechanisms for regulating MMP-1 gene expression under a variety of
biological and pathological conditions.
PMID- 10684972
TI - Heterologous expression of clostridial hydrogenase in the Cyanobacterium
synechococcus PCC7942.
AB - The Clostridium pasteurianum hydrogenase I has been expressed in the
cyanobacterium Synechococcus PCC7942. The Shine-Dalgarno sequence of the
structural gene encoding hydrogenase I from C. pasteurianum was changed to that
of the cat (chloramphenicol acetyltransferase) gene. The hydrogenase gene was
cloned downstream of a strong promoter, isolated from Synechococcus PCC7942, with
the cat gene as a reporter gene. Expression of clostridial hydrogenase was
confirmed by Western and Northern blot analyses in Synechococcus and Escherichia
coli, whereas in vivo/in vitro measurements and activity staining of soluble
proteins separated on non-denaturing polyacrylamide gels revealed functional
expression of hydrogenase only in cyanobacterial cells. The changed Shine
Dalgarno sequence appeared to be essential for the functional expression of
clostridial hydrogenase in Synechococcus, but had no influence on the expression
and activity of clostridial hydrogenase expressed in E. coli.
PMID- 10684973
TI - Cloning and expression of the genes involved in the production of and immunity
against the bacteriocin lacticin RM.
AB - The production of lacticin RM, a novel bacteriocin produced by Lactococcus lactis
subsp. lactis EZ26, is associated with the presence of a 6-kb plasmid, pHU1. The
information necessary for lacticin RM production and immunity was localized to a
2.5-kb SalI-Eco47III fragment. Sequencing analysis of this fragment revealed the
presence of six open reading frames (ORFs). Deletion and mutation analyses showed
that orfX and orfY are not required for lacticin RM production or immunity,
whereas the other ORFs (lacA, lacF, lacG and lacI) are necessary for the
bacteriocin's production. Transcription analysis indicated that lacA, lacF and
lacG are organized in an operon. lacA is probably the lacticin RM structural
gene. It putatively encodes a 134-amino acid peptide, and it does not share
homology with known bacteriocins. The deduced LacG protein is hydrophobic and
consists of six potential trans-membrane helices. lacF encodes a conserved ATP
binding domain homologous to ABC transporters known in bacteriocin immunity
systems. LacF and LacG may form an active ABC transporter. Gene-disruption
mutations indicated that both are required for immunity against lacticin RM. lacI
encodes a small cationic protein, which is required for the production of and
immunity to lacticin RM. Protection was obtained only when lacF, lacG and lacI
were present together.
PMID- 10684974
TI - Molecular characterization of the mouse Fas ligand promoter in airway epithelial
cells.
AB - Constitutively expressed Fas ligand in several distinct epithelial cell types
appears to protect tissues by inducing apoptosis of Fas(+) immune cells during
inflammatory reactions. To study the transcriptional regulation of Fas ligand
gene in airway epithelial cells, a 618-bp 5'-flanking region of mouse Fas ligand
gene was cloned, sequenced, and the transcriptional start site was determined by
using 5'-RACE. Deletion analysis, gel mobility shift assays and site-directed
mutagenesis indicated that a CCAAT box located -214 bp upstream from the
transcription start site served as a major positive regulatory cis-element in an
airway epithelial cell line. This element was not required for constitutive Fas
ligand expression in Sertoli cells. Furthermore, the activity of the site did not
involve the NF-Y protein complex or c/EBP protein family. UV-cross linking
proteins to this element indicated that a approximately 23-kDa transcription
factor bound to the Fas ligand promoter CCAAT box and, thus, likely plays an
important role in the regulation of Fas ligand expression in airway epithelial
cells.
PMID- 10684975
TI - Sp1 mediates constitutive and transforming growth factor beta-inducible
expression of urokinase type plasminogen activator receptor gene in human
monocyte-like U937 cells.
AB - Urokinase type plasminogen activator receptor (uPAR) is known to be involved in
conversion of plasminogen into plasmin and its expression can be regulated by a
variety of biological agents including transforming growth factor beta (TGF
beta). In the present study, we cloned the promoter region of the human uPAR
(huPAR) gene (-653 to +61) and investigated the transcription regulatory
mechanism of the expression of the huPAR gene upon treatment with TGF-beta in
human monocyte-like U937 cells. By deletion and point mutational analysis of the
huPAR gene promoter, it was found that the sequence positioned at -70 is required
for both constitutive and TGF-beta-inducible expression of the huPAR gene in U937
cells. Using electrophoretic mobility shift assay, we could observe that Sp1
formed a DNA-protein complex at the -70 sequence. In addition, antisense
oligonucleotide against human Sp1 blocked both constitutive and TGF-beta
inducible expression of the luciferase reporter gene driven by the huPAR gene
promoter in U937 cells. These results led us to conclude that Sp1 transcription
factor mediates constitutive and TGF-beta-inducible expression of the huPAR gene
in U937 cells through binding to the sequence located at -70.
PMID- 10684976
TI - Cloning and characterization of additional members of the G protein-coupled
receptor family.
AB - A search of the expressed sequence tag (EST) database retrieved a human cDNA
sequence which partially encoded a novel G protein-coupled receptor (GPCR) GPR26.
A human genomic DNA fragment encoding a partial open reading frame (ORF) and a
rat cDNA encoding the full length ORF of GPR26 were obtained by library
screening. The rat GPR26 cDNA encoded a protein of 317 amino acids, most similar
(albeit distantly related) to the serotonin 5-HT(5A) and gastrin releasing
hormone BB2 receptors. GPR26 mRNA expression analysis revealed signals in the
striatum, pons, cerebellum and cortex. HEK293 and Rh7777 cells transfected with
GPR26 cDNA displayed high basal cAMP levels, slow growth rate of clonal
populations and derangements of normal cell shape. We also used a sequence
reported only in the patent literature encoding GPR57 (a.k.a. HNHCI32) to PCR
amplify a DNA fragment which was used to screen a human genomic library. This
resulted in the cloning of a genomic fragment containing a pseudogene, psiGPR57,
with a 99.6% nucleotide identity to GPR57. Based on shared sequence identities,
the receptor encoded by GPR57 was predicted to belong to a novel subfamily of
GPCRs together with GPR58 (a.k.a. phBL5, reported only in the patent literature),
putative neurotransmitter receptor (PNR) and a 5-HT(4) pseudogene. Analysis of
this subfamily revealed greatest identities (approximately 56%) between the
receptors encoded by GPR57 and GPR58, each with shared identities of
approximately 40% with PNR. Furthermore, psiGPR57, GPR58, PNR and the 5-HT(4)
pseudogene were mapped in a cluster localized to chromosome 6q22-24. PNR and
GPR58 were expressed in COS cells, however no specific binding was observed for
various serotonin receptor-specific ligands.
PMID- 10684977
TI - Transcription factor GATA-6 activates expression of gastroprotective trefoil
genes TFF1 and TFF2.
AB - One of the early events in inflammation and epithelial restitution of the
gastrointestinal tract is the up-regulation of secretory peptides belonging to
the trefoil factor family (TFF) that promote cell migration, protect and heal the
mucosa. Their major expression site is stomach (TFF1, TFF2) and intestine (TFF3).
Located in the 5'-flanking region of the genes are several consensus sites for
members of the GATA transcription factors known to control gut-specific gene
expression. By reverse transcription-PCR (RT-PCR), GATA-6 was shown to be
expressed in a variety of tumor cell lines of gastric, intestinal and pancreatic
origin. In MKN45, KATOIII and LS174T, cotransfection with TFF reporter genes and
GATA-6 expression vectors revealed that GATA-6 activates TFF1 and TFF2 4-6-fold,
without an effect on TFF3. The functional contribution of GATA binding sequences
in the reverse orientation was further characterized by reporter gene assays
using TFF2 deletion constructs and by gel shift experiments.
PMID- 10684978
TI - Complete sequence and characterization of chick ventricular myosin heavy chain in
the developing atria.
AB - We isolated five complementary DNA (cDNA) clones, encoding the chick ventricular
myosin heavy chain (MyHC) by reverse transcription polymerase chain reaction (RT
PCR). The entire cDNA consists of 5995 nucleotides with the 52 bp 5'-untranslated
region and the 129 bp 3'-untranslated region. The complete cDNA encodes 1937
amino acids. Expression of the chick ventricular MyHC gene was also studied by
Northern blot analysis. This gene continued to be strongly expressed in the
ventricle during cardiac development. On the other hand, its expression was
moderate in the early embryonic atria, and was down-regulated during development.
In the adult atria, this gene was expressed at very low levels. To determine the
localization of the ventricular MyHC protein, an immunohistochemical study was
performed. The ventricular MyHC was present in early embryonic atrial myocytes.
During development, the expression of this protein in the atrial myocytes was
down-regulated, but continued to be present in the atrial conduction system. Our
results indicate that the ventricular MyHC appears in the primary atrial
myocardium and is then localized in the conduction cells of the atria.
PMID- 10684979
TI - Expression of CD80 promoter in transgenic mice.
AB - CD80 is a very potent co-stimulatory factor which is required for complete T-cell
activation. Here, we use transgenic mice as a tool to map the promoter of the
CD80 gene. We engineered three different CD80 promoter driven luciferase
transgenes: -3084, -1073 and -215. With these transgenes, we have generated three
groups of transgenic mice. Our results showed that the -3084 CD80
promoter/luciferase transgene was sufficient to confer tissue-specific expression
of the CD80 gene. When the promoter sequence was deleted to -1073, the normal
tissue-specific expression was lost. A brain-specific element was mapped between
1073 nt and -215 nt. This element caused up to ninefold higher expression of the
CD80 promoter/luciferase in brain tissue of -1073 CD80 promoter/luciferase
transgenic animals as compared to -3084 CD80 promoter/luciferase transgenic
animals. In contrast to results with a cell culture system, little luciferase
activity was detected in -215 CD80 promoter/luciferase transgenic animals.
PMID- 10684980
TI - Transcriptional regulation involving the intronic heat shock element of the rat
hsp27 gene.
AB - While sequencing the first intron of the rat heat shock protein 27 gene (hsp27),
we identified a consensus heat shock regulatory element (HSE). This intronic HSE
(i-HSE) is conserved among mammalian hsp27 genes. The aim of this study was to
investigate possible effects of this intronic HSE (i-HSE) on transcription from
the rat hsp27 promoter. Gel mobility shift assays indicated that the i-HSE bound
heat shock transcription factor 1 (HSF1) in a manner equivalent to that of HSE
present in hsp27 promoter (p-HSE). The effect of i-HSE on transcription from the
hsp27 promoter was evaluated using reporter constructs transiently transfected in
the osteosarcoma cell line ROS17/2.8. When inserted 5' to a 145 bp fragment of
the hsp27 promoter not containing p-HSE, a 215 bp fragment of hsp27 intron 1
containing i-HSE enhanced CAT activity and conferred heat shock-inducible
activity to the construct. This intronic fragment containing i-HSE also enhanced
CAT activity in either normal or heat-shocked culture conditions when inserted 3'
to the CAT open reading frame. However, in chimeric reporter constructs with a
273 bp hsp27 promoter containing p-HSE directly 5' to CAT reporter, and with a
215 bp fragment containing i-HSE inserted 3' to the CAT open reading frame,
transcription from hsp27 promoter was reduced under normal and heat-stressed
culture conditions. Mutation of the i-HSE reversed this effect. Further study is
required to define the mechanism by which the i-HSE-containing region of the
hsp27 promoter may mediate negative regulation of hsp27 transcription.
PMID- 10684981
TI - A gene cluster encoding plantaricin 1.25beta and other bacteriocin-like peptides
in Lactobacillus plantarum TMW1.25.
AB - Plantaricin 1.25beta is a thermostable class two bacteriocin produced by
Lactobacillus plantarum TMW1.25 isolated from sausage fermentation. It is co
produced with several other bacteriocin-like peptides. Using oligonucleotides
derived from previously determined peptide sequences, a 3.8 kb DNA fragment could
be amplified. A neighboring 1.8 kb fragment was amplified using ligation-anchored
single-specific-primer PCR. Sequencing of the complete 5.6 kb stretch revealed
that the structural gene for plantaricin 1.25beta, plnB, was located downstream
of another bacteriocin gene, plnC. Seven other open reading frames were detected,
including plnK encoding a bacteriocin-like peptide, but not including any
putative immunity genes. Interestingly, the gene cluster contained an IS30-like
insertion sequence, designated IS125, as well as an ISS1 homolog.
PMID- 10684982
TI - Structural conservation and variation among U5 small nuclear RNAs from
trypanosomatid protozoa.
AB - U5 snRNAs in trypanosomatid protozoa do not contain the trimethylguanosine cap
structures that are often targeted in snRNA isolation procedures. As a result,
the trypanosomatids are not well represented in the database of available U5
snRNA sequences. We have isolated and determined the sequence of the U5 snRNA
from Crithidia fasciculata. Comparison with previously published trypanosomatid
U5 snRNA sequences allows us to deduce the pattern of structural conservation and
variation among these very divergent snRNA molecules.
PMID- 10684983
TI - Corrigendum to 'Molecular cloning and expression of human neurochondrin-1 and
2'(1).
PMID- 10684984
TI - Androstenediol stimulates myelopoiesis and enhances resistance to infection in
gamma-irradiated mice.
AB - The ionizing radiation-induced hemopoietic syndrome is characterized by defects
in immune function and increased mortality due to infections and hemorrhage.
Since the steroid 5-androstene-3beta, 17beta-diol (5-androstenediol, AED)
modulates cytokine expression and increases resistance to bacterial and viral
infections in rodents, we tested its ability to promote survival after whole-body
ionizing radiation in mice. In unirradiated female B6D2F1 mice, sc AED elevated
numbers of circulating neutrophils and platelets and induced proliferation of
neutrophil progenitors in bone marrow. In mice exposed to whole-body (60)Co gamma
radiation (3 Gy), AED injected 1 h later ameliorated radiation-induced decreases
in circulating neutrophils and platelets and marrow granulocyte-macrophage colony
forming cells, but had no effect on total numbers of circulating lymphocytes or
erythrocytes. In mice irradiated (0, 1 or 3 Gy) and inoculated four days later
with Klebsiella pneumoniae, AED injected 2 h after irradiation enhanced 30-d
survival. Injecting AED 24 h before irradiation or 2 h after irradiation
increased survival to approximately the same extent. In K. pneumoniae-inoculated
mice (irradiated at 3-7 Gy) and uninoculated mice (irradiated at 8-12 Gy), AED
(160 mg/kg) injected 24 h before irradiation significantly promoted survival with
dose reduction factors (DRFs) of 1.18 and 1.26, respectively. 5-Androstene-3beta
ol-17-one (dehydroepiandrosterone, DHEA) was markedly less efficacious than AED
in augmenting survival, indicating specificity. These results demonstrate for the
first time that a DHEA-related steroid stimulates myelopoiesis, and ameliorates
neutropenia and thrombocytopenia and enhances resistance to infection after
exposure of animals to ionizing radiation.
PMID- 10684985
TI - Preliminary studies on the immunomodulatory effect of the C3 binding glycoprotein
isolated from Cuscuta europea.
AB - This study investigates the immunomodulatory effect of a C3 binding glycoprotein
(C3bgp), isolated from the parasitic plant Cuscuta europea. When BALB/c mice,
immunized with sheep red blood cells (SRBC), were given a single intraperitoneal
injection of C3bgp a dose-dependent immunostimulation was observed. The
stimulation was assessed by an increase in the number of haemolytic plaque
forming cells (PFC) and haemaglutination titres. The induction was time dependent
in respect to the administration of both the C3bgp and SRBC. When C3bgp was
applied 24 h before SRBC at a dose of 30 microg per mouse (1.2 mg/kg), a well
expressed immunostimulation was found. It was also found that giving C3bgp to
mice, which had previously been treated with the immunosuppressive drug
cyclophosphamide (CY), produced an increase in PFC. The immune response was also
restored in vitro experiments were performed using human whole blood cultures
stimulated with 30 microg/ml C3bgp in the presence or absence of egg albumin
(OVA) as antigen for 72 to 168 h. In C3bgp stimulated cultures it was found that
after 120 h there was a high expression of the CD 19+ subset of the activation
antigen CD25 (IL-2R) as assessed by flow cytometric phenotype analysis.
Supernatants from cultures with different stimuli were assayed by a solid phase
ELISA for the determination of OVA-specific IgM at 120, 144 and 168 h. It was
found that C3bgp application alone, failed to enhance OVA specific IgM, but
significantly high levels of IgM in cultures containing C3bgp and OVA, were
detected. Overall it has been shown that the C3 binding glycoprotein, as obtained
from the parasitic plant Cuscuta europea, has strong immunostimulatory properties
both in vivo and in vitro.
PMID- 10684986
TI - The effect of the antithyroid drug propylthiouracil on the alternative pathway of
complement in rats.
AB - The effect of propylthiouracil (PTU) on the lytic activity of complement in rat
serum was investigated in vivo. Rats (180+/-10 g) were treated daily by gavage
with PTU doses of 1-50 mg/200 g body weight for time intervals ranging from 1 to
30 days. Serum classical pathway (CP) and alternative pathway (AP) activities
were determined 24 h after the last dose. A single dose of 50 mg/200 g body
weight was administered to additional groups and the animals were sacrificed
after periods of 1-48 h. The results showed a relatively small reduction (
approximately 30%) in CP activity, evident only in animals treated with 50 mg of
PTU for three weeks. However, a clear and opposite effect of PTU, an increase in
lytic activity reaching values up to 180% of controls, was observed on AP
activity. This effect was seen at all PTU doses used, and occurred within 4 days
of treatment with the highest dose. Maximum activity was observed at intermediate
intervals, depending on the PTU dose, with a return to control levels occurring
after the longer periods of treatment. The lytic activity of serum from animals
treated with a single PTU dose of 50 mg/200 g body weight and sacrificed 1-48 h
after dosing did not differ from controls. Serum levels of thyroid hormone
(triiodo L-thyronine, T3, and thyroxine, T4) were determined in representative
groups of treated animals (injected with 5 mg of PTU/200 g body weight/day).
These were either undetectable or considerably lower than those of controls. The
serum PTU levels of these rats increased for up to 22 days, reaching values of 2
4 microg/ml.PTU is described in the literature as a modulator of both cellular
immune responses and antibody production. Upon complement activation fragments of
complement components bind to immune complexes and to specific receptors on cells
of the immune system. Thus, alteration in AP activity caused by PTU treatment
suggests a possible mechanism by which the drug exerts its modulatory effect.
Increased complement AP activity might affect events as antigen presentation and
hence the onset and course of the immune response.
PMID- 10684987
TI - Augmentation by interleukin-18 of MHC-nonrestricted killer activity of human
peripheral blood mononuclear cells in response to interleukin-12.
AB - Interleukin (IL)-18 is a novel cytokine with pleiotropic functions. In the
present study, we examined the induction of the killer activity of peripheral
blood mononuclear cells (MNC) against lung cancer cell lines upon treatment with
IL-18 in combination with IL-12. Cytotoxic activity was measured by standard
(51)Cr release assay. IL-18 (100 ng/ml) was found to significantly augment IL-12
induced killer activity in a MHC-nonrestricted manner against allogeneic NK
resistant Daudi cells and lung cancer cell lines: SBC-3, RERF-LC-AI and A549. IL
18 could augment IL-12-induced killer activity both at the optimal as well as
suboptimal doses of the latter. However, IL-18 was found to have little effect on
the killer activity of MNC induced by optimal or suboptimal dose of IL-2 or IL
15. Treatment of MNC with IL-18 in combination with IL-12 for a period of more
than 4 days was observed to optimally induce the killer activity. As for
induction of IFN-gamma production by MNC, IL-18 augmented that induced by IL-2
and IL-15, as well as that induced by IL-12. These results show the potential of
IL-18 in combination with IL-12 for clinical application in treatment of cancer.
PMID- 10684988
TI - Protected Trypanosoma cruzi infection in rats born to mothers receiving
interferon-gamma during gestation is associated with a decreased intramacrophage
parasite growth and preferential synthesis of specific IgG2b antibodies.
AB - We demonstrated that administration of interferon gamma (IFN-gamma) to pregnant
rats conferred partial resistance in their offspring to further challenge with
Trypanosoma cruzi. Because of the effects of IFN-gamma on macrophage activation
and immunoglobulin isotype selection, offspring were now studied to ascertain
whether this intervention modifies the in vitro replication of T. cruzi and
nitric oxide (NO) production by peritoneal macrophages (PE), together with the
anti-T. cruzi IgG isotypes. To evaluate the possibility of a detrimental effect
of IFN-gamma, serum levels of anti-sulphatide autoantibodies were also
investigated. Offspring were born to mothers undergoing one of the following
procedures during gestation: treatment with recombinant rat IFN-gamma, 50,000
IU/rat, five times/week for 3 weeks, which was started on the day of mating;
infection with 10(6) trypomastigotes of T. cruzi at 7, 14, and 21 days after
mating plus IFN-gamma treatment as given to the former group; the same protocol
except that physiological saline was injected instead of IFN-gamma; injection of
physiological saline only. Offspring were challenged at weaning with a similar
dose of T. cruzi, to constitute four groups of infected young, plus an additional
group of age-matched uninfected rats born to control mothers. PE were harvested
at day 7 postinfection (pi), exposed to parasites and further investigated for
the replication of T. cruzi and NO production, whereas ELISA studies for
measuring serum anti-T. cruzi IgG subclasses and anti-sulphatide autoantibodies
were performed at day 30 pi. The number of intracellular parasites in PE was
markedly decreased in young born to IFN-gamma-treated mothers, this not being
accompanied by higher nitrite levels in culture supernatants. Offspring delivered
by IFN-gamma-treated mothers showed no higher serum concentrations of anti
sulphatide autoantibodies, but exhibited a preferential synthesis of anti-T.
cruzi IgG2b antibodies. This rat isotype is known to fix complement and
constitutes the rat counterpart of IgG2a mouse immunoglobulins whose synthesis is
favoured by IFN-gamma.
PMID- 10684989
TI - Immunogenicity of an E. coli extract after oral or intraperitoneal
administration: induction of antibodies against pathogenic bacterial strains.
AB - For the treatment of recurrent infections of the urinary tract, a bacterial
extract (OM-89) consisting of immunostimulating components derived from 18
Escherichia coli strains is orally applied to patients. We investigated in a
mouse model the immunogenicity of the bacterial extract after intraperitoneal or
oral administration. After repeated administration of the extract, serum IgG and
IgA responses against the E. coli strains used for the preparation of OM-89 were
obtained. This antisera also recognized a number of bacterial strains isolated
from patients with urinary tract and enterohemorrhagic E. coli infections, and
bound to a variety of other pathogenic strains. Moreover, the supernatants of
cell cultures prepared from the urogenital tract of mice immunized with OM-89
contained increased levels of strain specific and of total IgG and IgA. Our
findings may contribute to explain the therapeutic effect of OM-89 demonstrated
in clinical studies.
PMID- 10684990
TI - Effects of imipenem and cilastatin on human T-lymphocytes derived from acute
leukemia patients with chemotherapy-induced leucopenia: studies of T-lymphocyte
responses in the presence of acute myelogenous leukemia (AML) blast accessory
cells.
AB - The effects of imipenem and cilastatin on human T-lymphocytes were studied in
vitro. As responder T-cells were used T-lymphocyte clones derived from acute
leukemia patients with chemotherapy-induced cytopenia, and the accessory cells
were highly enriched acute myelogenous leukemia (AML) blasts. The effects of
imipenem and cilastatin on phytohemagglutinin (PHA), anti-CD3 and anti-CD3+anti
CD28 stimulated activation were assayed, and in addition drug effects on cytokine
dependent proliferation of activated T-lymphocytes were investigated. Imipenem
inhibited IL2-dependent proliferation of activated CD4(+) and CD8(+) T-cell
clones, and an inhibition was also detected for IL7-, IL12-, IL15-, IL16- and
IL17-dependent clonal proliferation. Imipenem caused a weak inhibition of anti
CD3- and PHA-stimulated T-cell proliferation when using 50 Gy irradiated AML
blast accessory cells derived from various patients, whereas no effect was
observed for anti-CD3+anti-CD28 stimulated and allostimulated activation.
Imipenem decreased the release of IL4 and Interferon-gamma by T-cell clones
stimulated with anti-CD3 and PHA in the presence of native (nonirradiated) AML
blasts. The imipenem effects were observed at concentrations corresponding to
levels reached in vivo, whereas even high concentrations of cilastatin did not
alter T-cell responses. The T-lymphocyte inhibition is probably caused by a
direct effect of imipenem on the T-cells.
PMID- 10684991
TI - Influence of pyrrolidine dithiocarbamate on the inflammatory response in
macrophages and mouse endotoxin shock.
AB - To analyze the immunomodulatory effect of pyrrolidine dithiocarbamate (PDTC) on
the endotoxin (LPS) stimulated inflammatory response, we measured the LPS
stimulated cytokine and NO production in murine peritoneal macrophages, J774A.1
cells and human whole blood in the presence of PDTC (60 microM). PDTC
significantly inhibited the production of nitrite, IL-1beta and IL-6 in these
cells. TNFalpha release was stimulated in murine cells, but suppressed in human
whole blood. We further investigated the influence of PDTC on mortality and
cytokine release in mouse endotoxin shock. PDTC was i.p. injected 30 min prior to
the induction of endotoxin shock in female NMRI-mice and survival was
significantly improved as compared to controls (48% vs 20%, n=25 per group).
Plasma concentrations of TNFalpha were slightly augmented while IL-6 levels were
decreased in PDTC-treated animals as compared to controls, however, without
reaching significance. We conclude that PDTC is a potent immunomodulatory
substance that modulates the inflammatory response in vitro and reduces mortality
in mouse endotoxin shock. The pathophysiological mechanisms of the protective
effect of PDTC in vivo, however, appears to be pluripotent, comprising both
antioxidative properties and the inhibition of NF-kB.
PMID- 10684992
TI - Adamantylamide dipeptide stimulates hematopoiesis and increases survival in
irradiated mice.
AB - It has been demonstrated that the synthetic immunostimulatory compound,
adamantylamide dipeptide (AdDP) produces hematopoiesis-stimulating effects in
mice exposed to sublethal doses of ionizing radiation and increases survival in
experimental animals irradiated with a lethal dose. These findings might suggest
contingent extension of clinical indications for the administration of AdDP for
the conditions of hematopoietic suppression, especially in oncology.
PMID- 10684993
TI - Editorial
PMID- 10684994
TI - Inhibition of influenza virus replication by cocaine.
AB - Cocaine has been shown to have a number of diverse effects on the immune system.
The current investigators have previously demonstrated an inhibitory effect of
cocaine on murine hepatitis virus replication in peritoneal macrophages in vitro.
The present study was undertaken to examine the effects of cocaine on influenza
virus replication and to further characterize that effect in an animal model.
Cocaine was capable of inducing a dose-dependent reduction in influenza PR-8
replication using MDCK cells in vitro. Concentrations of 100 microg/ml caused a
50% reduction of virus. To further characterize the effect in vivo, C57Bl/6 mice
infected with influenza PR-8 by intranasal instillation were given daily ip
injections of 10 mg/kg cocaine just prior to and for 4 days after exposure to
influenza. Lungs from mice exposed to cocaine had viral titers that were reduced
approximately 50% compared to controls as demonstrated by hemagglutination
titers. Additional studies suggest that this reduction appears to be caused by an
increase of cocaine-induced interferon.
PMID- 10684995
TI - B cell stimulating activity of metallothionein in vitro.
AB - The effect of metallothionein (MT) on lymphocytes was studied in vitro. Rabbit MT
induced the proliferative responses of mouse splenocytes at concentrations of 1
25 microg/ml. MT synergistically enhanced Con A- or LPS-induced proliferative
response of splenocytes. A similar effect was also observed for rabbit
splenocytes at a similar concentration. Free heavy metals such as Cd and Zn only
weakly stimulated splenocytes. 2-mercaptoethanol (2-Me) abrogated the effect of
MT, suggesting that thiols in MT play an important role for splenocyte response.
MT stimulated splenocytes from MT-knockout mice as well as those from normal
control mouse. The responder cells for MT stimulation were B cells and MT also
induced B cell differentiation to produce Ig. MT induced the calcium influx of B
cells, but not T cells. These results indicate that MT has a potent
immunomodulating activity, especially on B cells.
PMID- 10684996
TI - Inhibitory effect of TMK-688 on late asthmatic responses as well as T-cell and
eosinophilic infiltration in guinea pigs with asthmatic reactions.
AB - The effects of an oral anti-allergic agent, TMK-688, which inhibits 5
lipoxygenase, at doses of 3.2 and 10 mg/kg were studied in guinea pigs with dual
phase asthmatic response. We previously observed that pretreatment with TMK-688
inhibited the late asthmatic response (LAR) induced by ovalbumin inhalation
exposure. The present study focused on the effect of TMK-688 on infiltration by T
cells and eosinophils. TMK-688 inhibited both T-cell and eosinophilic
infiltration. These findings suggest that TMK-688 is effective in inhibiting
infiltration of T-cells and eosinophilic chemotaxis, and thereby suppresses LAR.
PMID- 10684997
TI - In vitro IgE inhibition in B cells by anti-CD23 monoclonal antibodies is
functionally dependent on the immunoglobulin Fc domain.
AB - CD23, the low affinity receptor for IgE (FcvarepsilonRII), is involved in
regulation of IgE synthesis by B-lymphocytes. Five monoclonal antibodies to human
CD23 were generated from cynomolgus macaques immunized with purified soluble CD23
(sCD23). Four of the five primate antibodies blocked the binding of IgE complexes
to CD23 positive cells and also inhibited the production of IgE in vitro by IL-4
induced human peripheral blood mononuclear cells (PBMC). The variable domains of
several primate antibodies were utilized to construct chimeric macaque/human
(PRIMATIZED((R))) monoclonal antibodies. PRIMATIZED((R)) p5E8G1, containing human
gamma 1 constant region, inhibited IgE production in vitro as efficiently as the
parent primate antibody, but the human gamma 4 constant version, PRIMATIZED((R))
p5E8G4, was not as effective in IgE inhibition. An F(ab')(2) of p5E8G1 did not
inhibit IgE production but did interfere with IgE inhibition by the intact anti
CD23 antibody in a dose dependent fashion. The murine monoclonal antibody MHM6
recognizes human CD23 at a different epitope than primate antibody 5E8, and
inhibits IgE production by IL-4 induced PBMC. As with the F(ab')(2) of p5E8G1,
the F(ab')(2) of MHM6 also failed to inhibit IgE production. These data imply
that the mechanism by which anti-CD23 antibodies inhibit IgE production requires
cross-linking of CD23 to an IgG receptor. These data also imply that neither
bivalent cross-linking of CD23 alone or inhibition of CD23 binding to its natural
ligands is sufficient to inhibit IgE production.
PMID- 10684998
TI - Phenytoin and electric shock-induced apoptosis in rat peripheral blood
lymphocytes.
AB - The apoptotic index (AI) of peripheral blood lymphocytes (PBL) and plasma
corticosterone (CS) levels were determined in Wistar rats treated with phenytoin
(PHT) at therapeutic and toxic doses (100 or 200 mg/kg/day, respectively, over a
period of 7 days) and stressed by bifrontal electric shock (60 Hz/40 mA/0.2 seg).
The values of CS and AI were found to be significantly higher in rats submitted
to electric shock (ES) and in rats treated with therapeutic and toxic doses of
PHT plus ES, than in rats treated only with PHT (P<0.001). The plasma
concentrations of PHT were found to be significantly higher in rats treated with
toxic doses than in those treated with therapeutic doses (P<0.001), while the
control group (without treatment) and vehicle group (propilenglycol-ethanol
water, 40:10:50), showed low levels of CS, and less than 1% of AI. The DNA
analysis by electrophoresis in agarose in all the groups was positive, displaying
the ladder pattern characteristic of apoptotic process (200 bp), except in the
control groups (no treatment and vehicle treated). Our results demonstrate that
chronic stress, caused by ES, produces an elevation of CS. The values of
apoptosis were correlated with the CS levels, suggesting that the apoptotic
inductor process is a consequence of an increase in the concentration of
corticosterone in plasma, in response to the hypothalamic-pituitary-adrenals
(HPA) axis activation, while phenytoin at therapeutic doses is only a moderate
apoptosis inductor.
PMID- 10684999
TI - Nitrite inhalants spontaneously liberate nitric oxide, which is not responsible
for the immunotoxicity in C57BL/6 mice.
AB - Nitrite inhalant abuse has been correlated epidemiologically with HIV
seropositivity and with Kaposi's sarcoma. Using a mouse model, we have shown that
inhaled isobutyl nitrite caused anemia and severely depressed immunity. In the
present study, we showed that both isobutyl and cyclohexyl nitrites in air
liberated nitric oxide (NO). An immunotoxic dose of 900 ppm isobutyl nitrite
liberated 115 ppm NO. Mice were exposed in an inhalation chamber to 115 ppm NO,
900 ppm isobutyl nitrite, or 900 ppm cyclohexyl nitrite for 45 min/day. Following
a single exposure, NO did not affect peripheral blood cell counts, while isobutyl
and cyclohexyl nitrites reduced cell numbers. After 14 daily exposures, isobutyl
nitrite, but not cyclohexyl nitrite or NO, reduced peritoneal macrophage
tumoricidal activity. The nitrite esters likely caused immunotoxicity by
mechanisms other than NO release.
PMID- 10685000
TI - Gestational nicotine exposure alone or in combination with ethanol down-modulates
offspring immune function.
AB - Prenatal nicotine exposure has been shown to disrupt the development of a number
of peripheral organs. In the current study, we examined the effects of
gestational nicotine exposure, alone or in combination with ethanol exposure, on
offspring immune function. Timed pregnant rats were treated with either nicotine
(6 mg/kg/day) from gestation day 4-20 using subcutaneously implanted osmotic mini
pumps or ethanol administered in the drinking water (15% w/v) from gestation day
10-20. The combined exposure group received both treatments. The ability of
offspring T and B cells to proliferate in response to nonspecific stimulation by
Concanavalin A or lipopolysaccharide, respectively, was determined on postnatal
days 9, 15, 22, 29, 64, and 86. Offspring splenocyte beta(2)-adrenoceptor binding
was also measured. Nicotine or nicotine+ethanol suppressed splenocyte
responsiveness to Concanavalin A or lipopolysaccharide which was similar in
timing and magnitude to that seen with ethanol alone. Splenocytes from these
groups remained subresponsive to stimulation well into adulthood. The combined
drug treatment caused an overall reduction in spleen beta-adrenergic receptor
binding whereas the individual drug treatments did not alter the development of
spleen beta-adrenergic receptors.Our results indicate that prenatal nicotine
exposure can cause long-term suppression of the proliferative response of
offspring immune cells. Moreover, the effects of nicotine+ethanol may cause more
severe deficits in adulthood.
PMID- 10685002
TI - FK506 inhibition of histamine release and cytokine production by mast cells and
basophils.
AB - Histamine release and cytokine production by mast cells and basophils are thought
to be closely involved in the pathogenesis of allergic diseases. Some reports
show that FK506 (tacrolimus hydrate) inhibited histamine release and cytokine
production by mast cells and basophils. However, as the effects of FK506 has not
been compared with those of clinically used drugs in those reports, the clinical
relevancy of FK506 inhibition remained unclear. In this paper, we compared the
actions of FK506 with those of steroids or disodium cromoglycate (DSCG) which has
been clinically used. FK506 inhibited histamine release by Brown-Norway rat
peritoneal mast cells more potently than steroids and especially DSCG. FK506 also
inhibited histamine release by a mast rat basophilic leukemia (RBL)-1 cell line
and human peripheral blood basophils, whereas steroids failed to inhibit
histamine release by human basophils. FK506 as well as steroids inhibited TNF
alpha and IL-4 production by RBL-1 cells. FK506 was therefore more effective than
steroids and DSCG in inhibiting histamine release, and it also had the ability of
inhibiting cytokine production by mast cells as steroids do. We concluded that
FK506 might regulate allergic diseases via these actions, judging from the
viewpoint of clinical relevancy.
PMID- 10685001
TI - Cytokines potentiate human eosinophil superoxide generation in the presence of
N(omega)-nitro-L-arginine methyl ester.
AB - The eosinophilic (EOS) leukocyte has been implicated as a primary effector cell
in inflammatory and allergic diseases. Cytokines are among the mediators of
inflammatory and allergic diseases which modulate the effector functions of EOS.
Certain cytokines, elevated in patients with various allergies, are thought to
modulate EOS reactive oxygen species superoxide anion and nitric oxide (NO)
responses. Though EOS transcribe and translate mRNA for inducible NO synthase,
the effects of cytokines on NO generation remain largely unknown. Thus, we have
investigated effects of IL-3, IL-5, GM-CSF, IL-8, RANTES and the proinflammatory
cytokines TNF-alpha and IFN-gamma, on superoxide anion and NO generation by clone
15 HL-60 human eosinophilic cells. Cytokine treatments (3 and 18 h) resulted in
production of small amounts of superoxide anion which were enhanced by the NO
inhibitor L-NAME. In the presence of L-NAME, PMA (1 nM) stimulation significantly
increased superoxide anion generation following 3 h treatments with IL-3, TNF
alpha or IFN-gamma. Eighteen hour cytokine treatments with GM-CSF, IL-8, RANTES,
IFN-gamma or TNF-alpha primed the cells for enhanced reactive oxygen species
following exposure to an EOS stimulant. Inhibition of NO synthesis resulted in
increased levels of superoxide anion. Collectively, these results suggest that an
environment of proinflammatory cytokines may potentiate the generation of
reactive oxygen species by EOS. These results further suggest that at an
inflammatory site or during an allergic response, EOS may concomitantly
synthesize NO and generate superoxide anion, fractions of which may rapidly react
to form the potent oxidant peroxynitrite.
PMID- 10685003
TI - Modulatory effect of 7-thia-8-oxoguanosine on proliferation of rat thymocytes in
vitro stimulated with concanavalin A.
AB - 7-thia-8-oxoguanosine (immunosine) is a guanosine analogue showing
immunostimulatory activity on different components of the immune system,
including B lymphocytes, natural killer cells and macrophages. However, little is
known about its effect on T-cell functions. In this work it was demonstrated that
immunosine at concentrations between 10 microM and 1 mM stimulated proliferation
of rat thymocytes in vitro triggered by suboptimal concentrations of concanavalin
A (Con A). The effect correlated with increased interleukin 2 (IL-2) production,
upregulation of the IL-2 receptor alpha (IL-2Ralpha) expression and decreased
apoptosis of thymocytes in comparison to the effect of Con A alone.
PMID- 10685004
TI - Increased T cell cytotoxicity by Betathine-induced upregulation of TNFalpha.
AB - Betathine (BT) is a low molecular weight disulfide that has previously been shown
to exhibit in vivo antitumor activity in murine myeloma and melanoma models. We
have shown that BT treatment of both human T cells and monocytes is associated
with an increase in surface tumor necrosis alpha (TNFalpha) expression. Further,
in T cells and monocytes that have been stimulated with PMA and ionomycin, the
addition of BT results in a dose and time dependent increase in the percentage of
high TNFalpha-expressing cells. Unlike TNFalpha upregulation produced by the
commonly used thiol antioxidant N-acetyl-L-cysteine (NAC), the BT-induced
increase in TNFalpha is observed consistently in different donors. This increase
in surface TNFalpha is associated with elevated levels of TNFalpha mRNA. In
addition, expression of TNFalpha receptor I is also significantly enhanced by BT
treatment. The upregulation of surface TNFalpha by BT has functional
consequences, in that, BT-treated T cells exhibit enhanced cytotoxic activity.
Thus, increased TNFalpha expression may be one mechanism responsible for the
antineoplastic activity of BT.
PMID- 10685005
TI - Evidence for immunotoxic effects of crude Ginkgo biloba L. leaf extracts using
the popliteal lymph node assay in the mouse.
AB - Allergic reactions due to contact with different parts of the ancient tree Ginkgo
biloba L. have repeatedly been reported. Provocation tests in patients and animal
experiments have identified alkylphenols such as ginkgolic acids as causative
constituents. Leaf extracts from Ginkgo are widely used to treat peripheral or
cerebral circulatory disorders and Alzheimer's disease. Since alkylphenols are
also present in leaves, potential allergic and other immunological hazards of
such preparations have to be carefully controlled. Thus, we have evaluated if the
popliteal lymph node assay (PLNA) in the mouse may represent a suitable model for
the detection of constituents with immunotoxic properties in a complex mixture of
biologically active agents such as plant extracts. Subplantar injection (2 mg) of
a crude aqueous-ethanolic extract from Ginkgo leaves caused a significant
lymphoproliferative reaction (LPR) in the ipsilateral popliteal lymph node. PLNA
active compounds in this extract could be enriched in the lipophilic phase by
liquid-liquid partition between heptane and water. Chemical analysis of the
heptane extract revealed the presence of a high concentration of alkylphenols
(approx. 30%) and further subfractionation indicated that the enlargement of the
popliteal lymph node was mainly due to the content of ginkgolic acids. This
presumption was corroborated by observing a similar LPR following injection of a
purified mixture of ginkgolic or hydroginkgolic acids. Thus, our experiments
confirm that Ginkgo leaf extracts may contain constituents with immunotoxic
properties, underlining the need to apply adequate production procedures to
guarantee the completest possible removal of these compounds. The PLNA appears to
represent a simple test model for the detection, characterisation and control of
ingredients with potential immunotoxic side effects in complex herbal drugs.
PMID- 10685006
TI - Aflatoxin B(1) inhibits CD14-mediated nitric oxide production in murine
peritoneal macrophages.
AB - Aflatoxin B(1) (AFB(1)), a potent hepatocarcinogen, has been known to impair non
specific and specific immunity. Macrophages play an important role in host
defense against tumors and microorganisms and a number of compounds are
implicated in macrophage cytotoxicity. Since activated by the reaction of LPS
with CD14, macrophages produce nitric oxide (NO) that is a cytotoxic effector
molecule in cell killing. In the present study, we investigated whether the
alteration of CD14 level on macrophages by AFB(1) affects NO production in murine
peritoneal macrophages. When macrophages were stimulated with LPS after AFB(1)
pretreatment, or they were co-treated with LPS and AFB(1), the NO production
decreased in a dose-dependent manner. In contrast, when macrophages were post
treated with AFB(1) after LPS-stimulation, NO production was unchanged. DNA, RNA,
and protein synthesis were reduced by AFB(1)-pretreatment of macrophages. The
addition of anti-CD14 antibodies to the cultures decreased NO production further.
FACS analysis showed that the binding of anti-CD14 antibodies to the macrophages
was suppressed by AFB(1)-pretreatment followed by LPS-stimulation. However,
AFB(1) does not alter the binding anti-CD14 antibodies to the macrophages without
LPS-stimulation. In contrast, AFB(1) pretreatment increased an amount of CD14
released in culture medium. Taken together, these data indicate that the reduced
NO production in murine peritoneal macrophages by AFB(1)-pretreatment is related
to the suppressed expression of CD14 on macrophage membrane and to the increased
secretion of it to culture medium after LPS-stimulation.
PMID- 10685007
TI - Strain differences in binding properties of estrogen receptors in immature and
adult BALB/c and MRL/MP-lpr/lpr mice, a model of systemic lupus erythematosus.
AB - The aim was to compare binding properties of estrogen receptors in brain,
reproductive and immune tissues of immature and adult female BALB/c mice, and in
the same tissues of MRL/MP-lpr/lpr mice. The latter strain spontaneously develops
an autoimmune disease resembling human systemic lupus erythematosus (lupus; SLE).
It is hypothesized that estradiol, through its receptors, mediates the
progression of murine SLE. High-speed cytosols were prepared from hypothalamus,
spleen, thymus and uterus of both strains, and incubated with the synthetic
estrogen (3)H-moxestrol (NEN). Scatchard plots were derived from binding
isotherms obtained after in vitro incubation. In addition, cervical lymph nodes
from MRL mice could be used, but were too small in BALB/c mice. There was a
significant increase in the affinity of the binding reaction i.e. a decrease in
the apparent molar dissociation constant (Kd), in immune tissues and uterus with
maturation in MRL but not BALB/c mice, whose tissues had, overall, a lower
affinity for (3)H-moxestrol. Receptor concentrations were significantly higher in
spleen and cervical lymph nodes of adult compared with immature MRL mice, but the
opposite pattern was observed in BALB/c mouse spleen on maturation. These
properties of estrogen receptors in MRL mice may underlie estrogen-mediated
exacerbation of murine SLE.
PMID- 10685008
TI - Mutagenicity and antimutagenicity studies of tannic acid and its related
compounds.
AB - Tannic acid and its hydrolysed products such as ellagic acid, gallic acid and
propyl gallate were tested for mutagenicities using Ames Salmonella tester
strains TA98 and TA100. Also, the antimutagenic activities of these compounds
against a number of direct mutagens including 2-nitrofluorene (2-NF), 4,4'
dinitro-2-biphenylamine, 1-nitropyrene, 1,3-dinitropyrene, 2-nitro-p
phenylenediamine, 3-nitro-o-phenylenediamine, 4-nitro-o-phenylenediamine were
tested. None of these tannic acid compounds was mutagenic. They also failed to
show antimutagenic activity towards the tested direct mutagens. However, tannic
acid at non-growth inhibitory concentrations reduced the revertant numbers of
TA98 in the presence of S9 mix when benzidine, 3,3'-4,4'-tetraminobiphenyl, 4
aminobiphenyl, and N,N-N', N'-tetramethylbenzidine were used as the mutagens.
These results suggest that tannic acid, but not its hydrolytic products, affects
the metabolic activation of these mutagens.
PMID- 10685009
TI - Inhibitory effects of tea extracts on the mutagenicity of 1-methyl-1, 2,3,4
tetrahydro-beta-carboline-3-carboxylic acid on treatment with nitrite in the
presence of ethanol.
AB - It has been shown that the mutagenicity of 1-methyl-1,2,3, 4-tetrahydro-beta
carboline-3-carboxylic acid (MTCCA), a major mutagen precursor in soy sauce on
treatment with nitrite and ethanol, was strongly decreased by the addition of hot
water extracts of green, black and oolong teas in the reaction mixture when it
was treated with 50mM nitrite at pH3.0, 37 degrees C for 60min in the presence of
7.5% ethanol. The mutagenicity-decreasing activity of the teas was scarcely
decreased by washing the teas with chloroform and benzene and was partly
decreased by butanol and ethyl acetate. Typical polyphenols such as catechins
were shown to have the antimutagenicity dose dependently. The antimutagenicity
and the reducing power of tea extracts gave a positive good correlation. The
results suggest that the mutagenicity of MTCCA on treatment with nitrite in the
presence of ethanol may be decreased by the mixed fractions of lyophilic
components such as polyphenols, which have high reducing power such as catechins
and the other compounds which have little reducing power including the
derivatives of the catechins and so on. Although the antimutagenicity of teas and
catechins was also considerably effective when they were added after the
nitrosation, that of black tea and some catechins was less effective.
PMID- 10685010
TI - Indole-3-carbinol as a chemopreventive agent in 2-amino-1-methyl-6
phenylimidazo[4,5-b]pyridine (PhIP) carcinogenesis: inhibition of PhIP-DNA adduct
formation, acceleration of PhIP metabolism, and induction of cytochrome P450 in
female F344 rats.
AB - The chemopreventive properties of dietary indole-3-carbinol (I3C) were evaluated
by assessing its effect on DNA adduct formation and metabolism of the dietary
carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and the
induction of cytochromes P450 1A1 and -1A2 in female F344 rats. In experiment 1,
animals on I3C diets (0, 0.02% or 0.1%, w/w) were treated by gavage with
1mg/kg/day of PhIP for 23 days. On days 2, 9, 16 and 23, their 24-hr urine was
collected and unmetabolized PhIP was measured by GC/MS. On day 24, the animals
were sacrificed, and DNA from pancreas, spleen, white blood cells (WBCs), lung,
colon, kidney, mammary epithelial cells, caecum, heart, small intestine, liver
and stomach was isolated for determination of PhIP-DNA adduct levels by (32)P
postlabelling assays. Except in the mammary gland, I3C diets significantly
inhibited PhIP-DNA adduct formation in WBCs and in all organs, ranging from 34.7
to 67.7% with the 0.02% I3C diet to 68.4 to 95.3% with the 0.1% I3C diet. I3C
diets also significantly decreased the concentration of urinary unmetabolized
PhIP to 29.5-38.4% (0.02% I3C) and 12.8-17.8% (0.1% I3C) of values obtained with
the I3C-free diet. In experiment 2, animals were either treated by intubation of
I3C at 100 or 200mg/kg for 2 consecutive days or given an I3C-containing diet
(0.02% or 0.1%, w/w) for 2 weeks. The expression and activity of cytochromes P450
1A1 and -1A2 were studied by Northern blots, Western blots, and in vitro enzyme
determinations. Both the expression and activity of these cytochromes were
induced by all of the I3C treatments. It is concluded that, in the female F344
rat, dietary I3C inhibits PhIP-DNA adduct formation and accelerates PhIP
metabolism, probably through induction of cytochromes P450 1A1 and -1A2. The
chemopreventive properties of I3C in PhIP-induced carcinogenesis are probably
mediated through enhancement of PhIP detoxification pathways.
PMID- 10685011
TI - Effects of toxaphene on the immune system of cynomolgus (Macaca fascicularis)
monkeys. A pilot study.
AB - Toxaphene in glycerol/corn oil was administered at 1mg/kg body weight/day, 7
days/week in gelatin capsules to four healthy young adult cynomolgus (Macaca
fascicularis) (two male and two female) monkeys for 52 weeks. Control monkeys
ingested glycerol/corn oil only. Testing for immune effects was initiated at 34
weeks of treatment. Results included: reduced anti-sheep red blood cell (SRBC)
titres for immunoglobulins (Ig) M and G; increased IgG titres to pneumococcal
antigens, but not to the tetanus toxoid antigen; reduced T-helper/inducer mean
lymphocyte numbers and the mean T-helper/inducer:T-suppressor/cytotoxic cell
ratio and reduced respiratory burst activity in peripheral blood monocytes and
granulocytes, albeit no changes on the phagocytic activity of these cells were
detected. The above noted effects although not statistically significant (P0.05)
suggest that chronic exposure to low levels of toxaphene may be immunosuppressive
in cynomolgus monkeys and may pose a hazard to human health. To advance our
understanding of the degree of hazard that toxaphene may pose to human health, we
have undertaken additional chronic studies with a larger number of animals.
Particular attention is focused on determining the potential immunotoxic effects
of toxaphene in offspring following in utero exposure.
PMID- 10685012
TI - A combined subchronic (90-day) toxicity and neurotoxicity study of a single-cell
source of docosahexaenoic acid triglyceride (DHASCO oil).
AB - Docosahexaenoic acid (DHA), a 22-carbon long-chain polyunsaturated fatty acid of
the omega-3 family, is a major structural component of neural membranes and is a
particularly important nutrient during infant development. New safe and well
defined sources of DHA are required for infant formula fortification and dietary
supplementation. DHASCO oil is an algal-derived triglyceride containing 40-50%
DHA. Previous studies have shown that DHASCO oil is neither mutagenic nor toxic
in acute or 28-day subchronic tests. To further establish the safety of this oil,
a 90-day subchronic toxicity study in rats which included haematology, clinical
chemistry, pathology and ophthalmologic, neurobehavioural and neuropathological
assessments, using doses of 0.5 and 1.25g/kg body weight/day was performed. There
were no treatment-related adverse effects in any of the parameters measured at
either dose. Based on these results, the no-adverse-effect level (NOAEL) for
DHASCO oil under the conditions of this study corresponds to the highest dose
level. The DHA in the DHASCO oil was bioavailable, resulting in significant
elevations in the levels of this fatty acid in liver, heart and brain after 90
days of administration. In conclusion, this 90-day subchronic toxicity study
provides additional evidence that DHASCO oil is a safe and bioavailable source of
dietary DHA.
PMID- 10685013
TI - Effect of chronic cyanide intoxication on memory in albino rats.
AB - Cyanide is a chemical widely used in industry, and is a major environmental
pollutant. Its toxicity is caused by inhibition of cytochrome oxidase resulting
in histotoxic hypoxia. The effect of sublethal doses of cyanide on memory and
hippocampal neurotransmitters was studied in male Wistar strain albino rats.
Cyanide reduced the memory along with reduction in the levels of dopamine and 5
hydroxytryptamine in the hippocampus. Pre-existing malnutrition in the animals
exaggerated these effects.
PMID- 10685014
TI - Developmental toxicity of 2-ethylhexyl stearate.
AB - 2-Ethylhexyl stearate was investigated in an embryo-/foetotoxicity and
teratogenicity study on rats according to OECD guidelines for the testing of
chemicals (No. 414). Dose levels of 0 (arachidis oil), 100, 300 and 1000mg/kg
body weight/day were administered by gavage. Dams tolerated the applied dose
levels without any toxic effects. Pre- and post-implantation loss and mean
numbers of resorptions were unaffected by treatment. All parameters were
comparable with the animals of the control group. Skeletal and visceral
investigations revealed no treatment-related malformations. For embryo
/foetotoxicity, teratogenicity and maternal toxicity a NOAEL of 1000mg/kg was
deduced.
PMID- 10685015
TI - Clinical, biochemical and neurobehavioural studies of workers engaged in the
manufacture of quinalphos.
AB - 59 workers exposed to different chemicals during the manufacture of quinalphos,
an organophosphate pesticide (OP) and 17 control subjects were studied. Despite
similar blood acetylcholinestarase (AChE) levels in both the exposed and control
subjects, a significant number of exposed subjects had altered plantar and ankle
reflexes. Higher nervous functions such as memory, learning and vigilance were
also found to be affected in these subjects. These findings were attributed to
chronic low dose combined exposure to different chemicals used/formed in the
manufacture of quinalphos. The study raises the doubt that monitoring of AChE
alone among subjects engaged in the manufacture of OP pesticides may not be an
adequate safeguard as regards to their health.
PMID- 10685016
TI - Developmental toxicity study of Aquacoat ECD ethylcellulose aqueous dispersion
administered orally to rats.
AB - A developmental rat toxicity study of Aquacoat((R)) ECD was performed as part of
a program to evaluate the safety of the product. Groups of 25 presumed-pregnant
Charles River Sprague-Dawley CD rats received doses of 0, 903, 2709 and
4515mg/kg/day (dry weight basis) of Aquacoat ECD administered undiluted once
daily via oral gavage on days 6-15 of gestation. All surviving dams underwent
caesarean sectioning on day 20 of gestation. Foetuses were weighed, sacrificed
and subject to external, visceral and skeletal evaluations. No test material
related maternal deaths occurred; one high-dose female died on day 14 due to
gavage error. The only treatment-related clinical sign noted among dams receiving
2709mg/kg/day and greater was pale faeces which was attributed to the presence of
the test material in the faeces. No statistically significant differences were
noted among the measured maternal parameters. Foetal sex ratios and body weights
were similar in all groups. The results of external and visceral foetal
evaluations revealed no treatment-related alterations. The only statistically
significant findings noted during the skeletal evaluation were increased litter
incidences of incompletely ossified or wavy ribs noted among foetuses receiving
4515mg/kg/day, and a significant increase in the litter incidence of thickened
ribs at doses of 2709 and 4515mg/kg/day. Given the nature of these findings and
the lack of effects on any other parameter measured in this study, they were not
considered adverse effects of treatment. Under the conditions of this study, the
maternal and foetal no-observed-adverse-effect level (NOAEL) is in excess of
4515mg/mg/day.
PMID- 10685017
TI - In vivo cytogenetic studies on blends of aspartame and acesulfame-K.
AB - Aspartame and acesulfame-K, non-nutritive sweeteners, are permitted individually
in diets and beverages. These sweeteners of different classes, used in
combination, have been found to possess a synergistic sweetening effect. Whether
they also have a synergistic genotoxic effect is unknown. Swiss Albino male mice
were exposed to blends of aspartame (3.5, 35, 350mg/kg body weight) and
acesulfame-K (1.5, 15 and 150mg/kg body weight) by gavage. Bone marrow cells
isolated from femora were analysed for chromosome aberrations. Statistical
analysis of the results show that aspartame in combination with acesulfame-K is
not significantly genotoxic.
PMID- 10685018
TI - Review of the toxicologic properties of medium-chain triglycerides.
AB - Medium chain triglycerides (MCTs) are a family of triglycerides, containing
predominantly, caprylic (C(8)) and capric (C(10)) fatty acids with lesser amounts
of caproic (C(6)) and lauric (C(12)) fatty acids. MCTs are widely used for
parenteral nutrition in individuals requiring supplemental nutrition and are
being more widely used in foods, drugs and cosmetics. MCTs are essentially non
toxic in acute toxicity tests conducted in several species of animals. In ocular
and dermal irritation testing MCTs exhibit virtually no potential as ocular or
dermal irritants, even with prolonged eye or skin exposure. MCTs exhibit no
capacity for induction of hypersensitivity. Ninety-day toxicity tests did not
result in notable toxicity, whether the product was administered in the diet up
to 9375mg/kg body weight/day or by intramuscular (im) injection (up to 0.
5ml/kg/day, rabbits). There was no evidence that intravenous (iv) or dietary
administration of MCTs adversely affected the reproductive performance of rats or
resulted in maternal toxicity, foetal toxicity or teratogenic effects at doses up
to 4.28g/kg body weight/day (iv) or 12,500mg/kg body weight/day (dietary). There
was no evidence that dietary administration of MCTs adversely affected the
reproductive performance of pigs or resulted in maternal toxicity, foetal
toxicity or teratogenic effects at doses up to 4000mg/kg body weight/day in the
diet. In rabbits, following iv administration, the maternal and foetal no
observed-adverse-effect levels (NOAELs) were between 1.0 and 4.28g/kg body
weight/ day. A 2-year study in rats, conducted with a closely related compound
(tricaprylin, a triglyceride with C(8) fatty acids), provided no evidence of a
carcinogenic effect when the material was administered by oral gavage at levels
up to 10ml/kg (9.54g/kg) per day. Although tricaprylin was found to be positive
in one of five strains of Salmonella typhimurium in the presence of metabolic
activation in an Ames mutagenicity assay, the results of the carcinogenicity test
with tricaprylin and mutagenicity tests with caprylic acid indicate that MCTs do
not have the potential to be carcinogenic or mutagenic. The safety of human
dietary consumption of MCTs, up to levels of 1g/kg, has been confirmed in several
clinical trials.
PMID- 10685019
TI - Safety assessment of iron EDTA [sodium iron (Fe(3+)) ethylenediaminetetraacetic
acid]: summary of toxicological, fortification and exposure data.
AB - Iron EDTA [sodium iron (Fe(3+)) ethylenediaminetetraacetic acid (EDTA)], shown to
have a significant beneficial effect on iron status by increasing iron
bioavailability in human diets, has been proposed for use as a fortificant in
certain grain-based products including breakfast cereals and cereal bars. This
paper presents an assessment of the safety of iron EDTA for its intended uses in
these products. Iron EDTA, like other EDTA-metal complexes, dissociates in the
gastrointestinal tract to form iron, which is bioavailable, and an EDTA salt;
absorption of the metal ion and EDTA are independent. Because of this
dissociation, consideration of information on EDTA compounds other than iron EDTA
is relevant to this safety assessment. EDTA compounds are poorly absorbed in the
gastrointestinal tract and do not undergo significant metabolic conversion. They
have a low degree of acute oral toxicity. EDTA compounds are not reproductive or
developmental toxicants when fed with a nutrient-sufficient diet or minimal diets
supplemented with zinc. In chronic toxicity studies, diets containing as much as
5% EDTA were without adverse effects. EDTA compounds were not carcinogenic in
experimental animal bioassays and are not directly genotoxic. This lack of
significant toxicity is consistent with a history of safe use of other EDTA
compounds (CaNa(2)EDTA and Na(2)EDTA) approved by the FDA for use as direct food
additives. An upper-bound estimated daily intake (EDI) of EDTA from iron EDTA
(1.15mg/kg bw/day for the US population) is less than half the acceptable daily
intake (ADI) for EDTA of 2. 5mg/kg bw/day established by JECFA. The data
collected and published over the past 20 to 30 years demonstrate that iron EDTA
is safe and effective for iron fortification of food products and meets the
standard of "reasonable certainty of no harm". Based on the published record,
iron EDTA may be regarded as generally recognized as safe (GRAS) for the intended
food uses and maximum use levels.
PMID- 10685020
TI - The 'considerate' smoker in public space: the micro-politics and political
economy of 'doing the right thing'.
AB - This paper examines the discourse of 'interactions' as applied to the
interpersonal management of smoking in public places (and to accounts thereof).
Empirical data from a qualitative study of smokers and non-smokers in
metropolitan Toronto, Ontario (Canada) are used to illustrate how smokers and non
smokers define and claim to operationalize 'consideration' in their daily lives.
Drawing on the work of Foucault, Rose, Castel, and Bourdieu, the paper explores
the possible significance of 'consideration' as a discourse of risk management
masked as 'common sense', as a marker of social competence. In particular,
parallels with emergent forms of governmentality embedded in community
participation and individual self-monitoring and self-restraint are noted.
Further, the social control implications of 'consideration' as moral discourse
are examined with respect to Bourdieu's analysis of class struggles for (social)
distinction. In this light, it is suggested that legitimate health concerns
raised by tobacco control advocates cannot be divorced from other implicit social
agendas which also fuel the drive for the 'purification of public space'.
PMID- 10685021
TI - Efficiency of care at the primary-secondary interface: variations with GP
fundholding.
AB - The aim of the study was to investigate the processes of referral for out
patients care and the interface with general practice, from the perspective of
the patient, the patient's general practitioner and hospital specialist. The
analyses reported here present variations with fundholding and non-fundholding
general practice. The design was a questionnaire survey of out-patients, their
hospital specialists and general practitioners, in six, randomly sampled district
health authorities in the North Thames Region, with stratification by area. The
measures included validated items and scales on process, quality and patient
satisfaction with services. Fundholders were more likely to have technical
equipment and services available within the practice. There were no differences
between fundholders and non-fundholders and the number of out-patient attendances
made by their patients, hospital out-patient waiting list times, patients'
waiting times in hospital clinics, nor in patients' satisfaction with out
patients and other process indicators. Fundholding is currently being replaced
with the proposed wider locality commissioning schemes, with GPs, health
authorities and other purchasing bodies acting in partnership. Health authority
commissioning will be required to reflect the preferences of GPs. Participants in
these schemes will need to pay particular attention to the areas where research
indicates that fundholding GPs made little difference to increasing the
efficiency and effectiveness of health care both in their own practices and at
the primary-secondary care interface.
PMID- 10685022
TI - Health and hygiene knowledge, attitudes and behaviour.
AB - The aim of this study was to develop and test measures of health and hygiene
knowledge, attitudes and behaviour. A questionnaire was administered to 240
women: 80 from a squatter camp, 80 from an informal settlement and 80 from a
formal township. Reliability of the knowledge scale was 0.73. Coefficient alpha
was 0.87 for the attitude and behaviour scales. The knowledge, attitude and
behaviour scales were significantly related (P<0.001). Factor analysis confirmed
that domestic and personal hygiene were core components of the attitude scale,
whereas the emphasis for behaviour was on personal hygiene. Stepwise regression
showed that age explained 23% of the variance in knowledge and 18% in behaviour.
Waste management significantly affected knowledge, attitudes and behaviour,
suggesting that dustbin ownership was an important public health measure. It was
concluded that these scales were useful measures of health and hygiene knowledge,
attitudes and behaviour; provided baseline information for planning health
promotion programmes; and could be used to evaluate the effectiveness of such
programmes.
PMID- 10685023
TI - Determinants of geographic mobility among participants in a population-based
HIV/AIDS drug treatment program.
AB - This study was undertaken to determine the geographic distribution and patterns
of migration of persons with HIV in British Columbia. Our analysis was restricted
to all HIV-positive men and women aged 18 years and over who had completed a
participant survey and were enrolled in the HIV/AIDS Drug Treatment Program
between September 1992 and September 1997. Patterns of migration were determined
by examining participants whose postal code changed between July 1995 and
September 1997. Statistical analysis were carried out using both parametric and
non-parametric methodologies. Stepwise logistic regression was used to determine
baseline predictors of migration. The final multivariate model revealed that
residing in a census subdivision with a population less than 100,000, being
heterosexual, acquiring HIV through intravenous drug use, and the absence of AIDS
at baseline were all independently associated with moving census subdivisions
during the period of observation. In summary, our analyses demonstrate the need
for the continued study of the evolving geography and migration patterns of
persons with HIV.
PMID- 10685024
TI - Urbanization and the urban mortality change in Imperial Germany.
AB - This analysis assesses urban mortality change in Imperial Germany, when the
country was going through a process of accelerated industrialization and
urbanization. Urban mortality reached its peak after the middle of the century,
thereafter urban mortality improved substantially. The largest cities,
particularly in the highly industrialized western parts of the country,
registered the strongest decline. A key element in this process was the reduction
of mortality from gastrointestinal disorders, affecting almost exclusively
infants. Therefore this analysis discusses the impact of selected public health
strategies designed to fight high infant mortality rates. Special emphasis is
placed on municipal milk supply and infant welfare centres.
PMID- 10685025
TI - Health, place and British prisons.
AB - This short communication considers people's health care needs in prison. It shows
that people have a wide range of health care needs that are not always met when
they spend time in prison. To locate these issues the paper draws on the "patient
or prisoner" debate to understand the challenges that face future policies.
PMID- 10685026
TI - Biochemical and compositional analyses of recombinant lecithin:cholesterol
acyltransferase (LCAT) obtained from a hepatic source.
AB - Lecithin:cholesterol acyltransferase (LCAT) is an important plasma glycoprotein
which plays a central role in lipid metabolism. This protein is responsible for
generation of cholesteryl esters in plasma and it has been proposed to play a
pivotal role in the reverse cholesterol transport pathway. Structural and
functional studies of LCAT have employed various expression systems for
production of recombinant LCAT (rLCAT). However, recent studies have shown some
differences in the oligosaccharide structure and composition of rLCAT. In this
study, we have generated a new hepatic based expression system using McArdle
RH7777 (Mc-7777) cells to produce a recombinant protein most similar to human
plasma LCAT. The expressed glycoprotein was compared to the LCAT expressed in
previously characterized baby hamster kidney (BHK) cells. Both proteins were
compared on the basis of their carbohydrate structure and composition as well as
their functional properties. Although the functional properties of both
glycoproteins were similar, the carbohydrate structure was significantly
different. While BHK-LCAT contained bi-, tri-, and tetraantennary structures, Mc
7777 LCAT presented only biantennary oligosaccharide structures. The difference
in glycosylation pattern of rLCAT from Mc-7777 and BHK cells underlines the
importance of appropriate expression system, both in vivo and in vitro.
PMID- 10685027
TI - Conformation of apolipoprotein E both in free and in lipid-bound form may
determine the avidity of triglyceride-rich lipoproteins to the LDL receptor:
structural and kinetic study.
AB - Slow refolding of human apolipoprotein E (apoE) in solution after guanidine- or
cholate-induced denaturation followed by dialysis under controlled conditions was
investigated using various spectroscopic properties of fluorescein- and dansyl
labeled apolipoprotein molecules. The results suggest that the last phase(s) of
apoE refolding in solution include a slow (several hours at 24 degrees C)
interconversion of a self-associated 'open' conformer into a more dense 'closed'
conformer. The hydrophobic interactions are primarily responsible for the
formation of this more compact apoE structure. To visualize the contribution of
apolipoprotein conformation and/or the number of 'active' lipid-bound apoE
molecules in the reaction of binding to the low density lipoprotein receptor
(LDLr) by solid-phase binding assay, the complexes of human plasma apolipoprotein
or recombinant (rec) apoE3 with dipalmitoylphosphatidylcholine (DPPC) or
palmitoyloleoylphosphatidylcholine (POPC) varying in size were used. For seven
complexes with plasma protein (four DPPC and three POPC complexes), the final
phosphatidylcholine (PC)/protein mole ratio ranged from 117 to 279; affinity
constant K(a) averaged for both PCs and plotted against this ratio abruptly
increased from 3.8 x 10(7) to 3.8 x 10(8) M(-1) with a transition midpoint of 150
180 PC/apoE, mole ratio. Two DPPC complexes with rec protein bind much more
efficiently. Complexes with both plasma and rec apoE were able to compete with
very low density lipoproteins (VLDL) or low density lipoproteins (LDL) isolated
from patients with E3/3 phenotype, for binding to the LDLr. Again, the
competition efficiency abruptly increased at the increase in PC content with a
transition midpoint of 130 PC/apoE, mole ratio. The transitions observed both in
direct and competitive binding assay probably correspond to the abrupt increase
in the number of 'active' apoE molecules on the complex surface accompanying the
change in the size and/or in the shape of the complexes. The efficiency of apoE
and apoB as the corresponding major ligands in the binding reaction of VLDL and
LDL to the LDL receptor was compared. VLDL bind to LDLr following a simple
encounter complex model, while LDL binding was characterized by a more complex
two-step model with an additional isomerization step. The analysis of the binding
data led us to suggest the existence of the continuum from several (2-3) apoE
molecules on the surface of TG-rich particles that resulted in the increased
binding affinity, on average 3.5-fold higher, compared to LDL. The existence of a
complex equilibrium between aqueous and different lipid-bound forms of apoE is
proposed, in particular, the formation of a transient disc-lipoprotein particle
structure during the interaction with LDLr in vivo as well as in LPL-stimulated
lipolysis of the lipid phase of the particle.
PMID- 10685028
TI - Structural peculiarities of the binding of very low density lipoproteins and low
density lipoproteins to the LDL receptor in hypertriglyceridemia: role of
apolipoprotein E.
AB - Very low (VLDL) and low density lipoproteins (LDL) were isolated from plasma of
patients with the E3/3 phenotype which were divided into three groups based on
their plasma triglyceride content: low (TG<200 mg/dl, TG(l)), intermediate
(200<300 mg/dl, TG(i)300 mg/dl, TG(h)). The protein density (PD) on the VLDL and
LDL surface was calculated from lipoprotein composition and protein location was
studied by tryptophan fluorescence quenching by I(-) anions at 25 degrees C and
40 degrees C. A comparison of the TG(h) with the TG(l) group revealed a
significant (<0.05) increase of the PD parameter as much as 21% for VLDL, but not
for LDL where this parameter did not change for any group; generally, PD(LDL)
values were 3.2-3.8-fold lower than PD(VLDL). In accordance with this difference,
the tryptophan accessibility f in VLDL vs. LDL was lower at both temperatures.
There were temperature-induced changes of the f parameter in opposite directions
for these lipoproteins. The difference in f value gradually decreased for VLDL in
the direction TG(l)TG(i)TG(h) while for LDL there was a U-shaped dependence for
these groups. The Stern-Volmer quenching constant K(S-V) which is sensitive to
both temperature and viscosity, did not change for VLDL, but K(S-V)(LDL) was 2-3
fold higher for the TG(i) group compared to the other two. The efficiencies of
VLDL and LDL binding to the LDL receptor (LDLr) in vitro were compared by solid
phase assay free of steric hindrance observed in cell binding. The maximal number
of binding sites did not change for either type of particles and between groups.
The association constant K(a) and apolipoprotein (apo) E/apoB mole ratio values
all increased significantly for VLDL, but not for LDL, in comparison of the
TG(i+h) with the TG(l) group. Based on VLDL and LDL concentrations in serum and
on the affinity constant values obtained in an in vitro assay, VLDL
concentrations corresponding to 50% inhibition of LDL binding (IC(50)) were
calculated in an assumption of the competition of both ligands for LDLr in vivo;
the mean values of IC(50) decreased 2-fold when plasma TG exceeded 200 mg/dl. The
functional dependences of K(a)(VLDL), IC(50) and apoE content in VLDL (both
fractional and absolute) and in serum on TG content in the whole concentration
range studied were fitted to a saturation model. For all five parameters, the
mean half-maximum values TG(1/2) were in the range 52-103 mg/dl. The efficiency
of protein-protein interactions is suggested to differ in normolipidemic vs. HTG
VLDL and apoE content and/or protein density on VLDL surface may be the primary
determinant(s) of the increased binding of HTG-VLDL to the LDL receptor. ApoCs
may compete with apoE for the binding to the VLDL lipid surface as plasma
triglyceride content increases. The possible competition of VLDL with LDL for the
catabolism site(s) in vivo, when plasma TG increases, could explain the
atherogenic action of TG-rich lipoproteins. Moreover, the 'dual action'
hypothesis on anti-atherogenic action of apoE-containing high density
lipoproteins (HDL) in vivo is suggested: besides the well-known effect of HDL as
cholesteryl ester catabolic outway, the formation of a transient complex of apoE
containing discs appearing at the site of VLDL TG hydrolysis by lipoprotein
lipase with VLDL particles proposed in our preceding paper promotes the efficient
uptake of TG-rich particles; in hypertriglyceridemia due to the diminished HDL
content this uptake seems to be impaired which results in the increased
accumulation of the remnants of TG-rich particles. This explains the observed
increase in cholesterol and triglyceride content in VLDL and LDL, respectively,
due to the CETP-mediated exchange of cholesteryl ester and triglyceride molecules
between these particles.
PMID- 10685029
TI - Upregulation of uncoupling protein 2 mRNA in genetic obesity: lack of an
essential role for leptin, hyperphagia, increased tissue lipid content, and TNF
alpha.
AB - Uncoupling protein 2 (UCP2) has been proposed to play a prominent role in the
regulation of energy balance. UCP2 mRNA expression is upregulated in white
adipose tissue (WAT) and liver, but is not altered in skeletal muscle in
genetically obese ob/ob mice. The mechanisms involved in the upregulation of UCP2
in obesity have not been investigated. We have now examined the potential role of
leptin, hyperphagia, increased tissue lipid content, and overexpression of tumor
necrosis factor (TNF)-alpha in the upregulation of UCP2 mRNA expression in the
liver and WAT in ob/ob mice. Treatment of ob/ob mice with leptin for 3 days
significantly reduced their food intake but had no effect on the upregulation of
UCP2 mRNA levels in the liver or WAT. To investigate the effect of feeding and
higher tissue lipid content on the upregulation of UCP2 in liver and WAT, we
compared UCP2 mRNA levels in ad-libitum fed and 72-h fasted control and ob/ob
mice. In controls, fasting had no effect on UCP2 mRNA levels in liver, but
increased UCP2 mRNA in WAT suggesting that the effects of fasting on UCP2 mRNA
levels are tissue-specific. In ob/ob mice, fasting did not lower UCP2 mRNA levels
in liver or WAT suggesting that the upregulation of UCP2 in ob/ob mice is not
merely a direct consequence of increased food intake. 72-h fasting lowered
hepatic total lipid content by 34% and 36% in control and ob/ob mice,
respectively, without any corresponding decrease in hepatic UCP2 mRNA levels,
suggesting that the enhanced UCP2 expression in the liver of ob/ob mice is not
secondary to lipid accumulation in their livers. Although TNF-alpha has been
shown to acutely increase UCP2 mRNA levels in liver and WAT, and is overexpressed
in adipose tissue in obesity, deletion of the genes for both TNF receptors in
ob/ob mice produces a further increase in UCP2 mRNA expression in liver and
adipose tissue indicating a paradoxical inhibitory role. Taken together, these
results suggest that the upregulation of UCP2 mRNA levels in the liver and WAT of
ob/ob mice is not due to the lack of leptin, hyperphagia, increased tissue lipid
content, or over-expression of TNF-alpha.
PMID- 10685030
TI - LTA(4)-derived 5-oxo-eicosatetraenoic acid: pH-dependent formation and
interaction with the LTB(4) receptor of human polymorphonuclear leukocytes.
AB - 5-oxo-(7E,9E,11Z,14Z)-eicosatetraenoic acid (5-oxo-ETE) has been identified as a
non-enzymatic hydrolysis product of leukotriene A(4) (LTA(4)) in addition to 5,12
dihydroxy-(6E,8E,10E, 14Z)-eicosatetraenoic acids (5,12-diHETEs) and 5,6
dihydroxy-(7E,9E, 11Z,14Z)-eicosatetraenoic acids (5,6-diHETEs). The amount of 5
oxo-ETE detected in the mixture of the hydrolysis products of LTA(4) was found to
be pH-dependent. After incubation of LTA(4) in aqueous medium, the ratio of 5-oxo
ETE to 5,12-diHETE was 1:6 at pH 7.5, and 1:1 at pH 9.5. 5-Oxo-ETE was isolated
from the alkaline hydrolysis products of LTA(4) in order to evaluate its effects
on human polymorphonuclear (PMN) leukocytes. 5-Oxo-ETE induced a rapid and dose
dependent mobilization of calcium in PMN leukocytes with an EC(50) of 250 nM, as
compared to values of 3.5 nM for leukotriene B(4) (LTB(4)500 nM for 5(S)-hydroxy
(6E,8Z,11Z,14Z)-eicosatetraenoic acid (5-HETE). Pretreatment of the cells with
LTB(4) totally abolished the calcium response induced by 5-oxo-ETE. In contrast,
the preincubation with 5-oxo-ETE did not affect the calcium mobilization induced
by LTB(4). The calcium response induced by 5-oxo-ETE was totally inhibited by the
specific LTB(4) receptor antagonist LY223982. These data demonstrate that 5-oxo
ETE can induce calcium mobilization in PMN leukocyte via the LTB(4) receptor in
contrast to the closely related analog 5-oxo-(6E,8Z,11Z, 14Z)-eicosatetraenoic
acid which is known to activate human neutrophils by a mechanism independent of
the receptor for LTB(4).
PMID- 10685031
TI - Analysis of sulfatide from rat cerebellum and multiple sclerosis white matter by
negative ion electrospray mass spectrometry.
AB - The accumulation of sulfatide (sulfatogalactosyl cerebroside) and changes in the
sulfatide species present have been examined in the cerebellum of day 6-32 aged
rats and in multiple sclerosis (MS) tissue samples. Negative ion electrospray
mass spectrometry with daughter and parent ion analyses were used to distinguish
the fatty acyl character in the amide linkage of sulfatide; measurement was done
by selected ion and multiple reaction monitoring of individually identified
sulfatide molecules. Sulfatide accumulation in rat cerebellum shows that 18:0-
and hydroxylated 18:0-sulfatide are the first sulfatide molecules detectable.
Very long fatty acyl chain sulfatide molecules (>20:0) are present at day 7 and
the ratio of non-hydroxylated compared to hydroxylated sulfatide rises as the
amount of non-hydroxylated sulfatide increases. 24:1-sulfatide accumulates at a
ratio of about 3:1 over 24:0-sulfatide during active myelination. Analyses of the
sulfatide in human tissue have shown differences between MS plaque tissues,
normal appearing adjacent white matter and control tissues. The findings show
that total sulfatide is reduced by 60% in the plaque matter and decreased 25% in
adjacent normal appearing white matter. There are significant increases (P=0.05)
in the amount of hydroxylation of sulfatide, demonstrated by an increase in the
percentage of hydroxylated h24:0-sulfatide (hydroxy-lignoceroyl sulfatide).
PMID- 10685032
TI - Enzymological properties of the LPP1-encoded lipid phosphatase from Saccharomyces
cerevisiae.
AB - The product of the LPP1 gene in Saccharomyces cerevisiae is a membrane-associated
enzyme that catalyzes the Mg(2+)-independent dephosphorylation of phosphatidate
(PA), diacylglycerol pyrophosphate (DGPP), and lysophosphatidate (LPA). The LPP1
encoded lipid phosphatase was overexpressed 681-fold in Sf-9 insect cells and
used to examine the enzymological properties of the enzyme using PA, DGPP, and
LPA as substrates. The optimum pH values for PA phosphatase, DGPP phosphatase,
and LPA phosphatase activities were 7. 5, 7.0, and 7.0, respectively. Divalent
cations (Mn(2+), Co(2+), and Ca(2+)), NaF, heavy metals, propranolol,
phenylglyoxal, and N-ethylmaleimide inhibited the PA phosphatase, DGPP
phosphatase, and LPA phosphatase activities of the enzyme. The inhibitory effects
of N-ethylmaleimide and phenylglyoxal on the LPP1-encoded enzyme were novel
properties when compared with other Mg(2+)-independent lipid phosphate
phosphatases from S. cerevisiae and mammalian cells. The LPP1-encoded enzyme
exhibited saturation kinetics with respect to the surface concentrations of PA
(K(m)=0.05 mol%), DGPP (K(m)=0.07 mol%), and LPA (K(m)=0.08 mol%). Based on
specificity constants (V(max)/K(m)LPA (1.3 units/mg/mol%). DGPP (K(i)=0.12 mol%)
was a competitive inhibitor with respect to PA, and PA (K(i)=0.12 mol%) was a
competitive inhibitor with respect to DGPP. This suggested that the binding sites
for these substrates were the same. The enzymological properties of the LPP1
encoded enzyme differed significantly from those of the S. cerevisiae DPP1
encoded lipid phosphatase, a related enzyme that also utilizes PA, DGPP, and LPA
as substrates.
PMID- 10685033
TI - A view on the science: physical anthropology at the millennium.
PMID- 10685034
TI - Maxillary sinusitis as an indicator of respiratory health in past populations.
AB - Chronic infectious respiratory disease in a past human population is investigated
through the quantification of maxillary sinusitis among Iroquoian
horticulturists. Three hundred forty-eight right and left maxillae of a Southern
Ontario Iroquoian skeletal sample, Uxbridge Ossuary, ca. AD 1440, were examined
for evidence of chronic infection (minimum number of individuals = 207: 114
adults, 22 adolescents, 38 juveniles and 33 infants). Modern clinical criteria
were applied to differentiate lesions of respiratory and dental origin. Osseous
lesions of the maxillary sinuses were observed in 50% of the individuals
examined. These lesions are morphologically consistent with nonspecific lesions
observed in other past populations that have been attributed to the presence of
pathogens. The prevalence of maxillary sinusitis increases with age. Osseous
changes suggestive of maxillary sinusitis of respiratory origin are at a maximum
prevalence in juveniles and adolescents. In adults, infection of dental origin
becomes a confounding factor in the identification of sinusitis of respiratory
origin. Fifteenth century Iroquoians were experiencing high airborne pathogen
levels and poor indoor air quality. The prevalence of maxillary sinusitis and the
exploration of the origin of tissue injury may contribute to our reconstruction
of the quality of life and the respiratory health status of past human
populations.
PMID- 10685035
TI - Cribra orbitalia in two temporally disjunct population samples from the Dakhleh
Oasis, Egypt.
AB - Cribra orbitalia (CO), an osseous sign of anemic stress, occurs in 67% (n = 296)
of the pre-Roman (n = 153) and Roman (n = 143) period crania from the Dakhleh
Oasis, Egypt. CO is primarily a childhood condition in these samples, and its
prevalence is significantly higher in virtually all cohorts in the pre-Roman
group, including among females, who display higher rates of active lesions. This
temporal trend suggests that the underlying causative factors (i.e., synergism
between disease and nutrition) were less pervasive in the Roman period. In both
population samples, anemic stress develops in some perinates prior to the
expected minimum age for the development of iron deficiency anemia. This suggests
additional causes of anemic stress in the Dakhleh population. A strong candidate
is folic acid deficiency and its concomitant, megaloblastic anemia, which results
from weaning of infants on goat's milk, a known practice in ancient Egypt. The
putative incorporation of other food items in the weanling diet, particularly
honey, a confirmed source of C. botulinum, represents yet another retrospective
data source to help understand the epidemiological profile of cribra orbitalia in
this population. Comparative data from other Egyptian populations, though
limited, show similar patterns, however, they display a lower prevalence than the
data from Dakhleh.
PMID- 10685036
TI - Sex differences in activity-related osseous change in the spine and the gendered
division of labor at Ensay and Wharram Percy, UK.
AB - Sex differences in the distribution of vertebral degenerative and plastic change
were examined and compared within and between samples of 51 individuals from the
historically and ethnographically documented 16th-19th century site of Ensay, the
Outer Hebrides, and 59 individuals from the medieval site of Wharram Percy, the
Yorkshire Wolds. Both populations have a known gendered division of labor between
males and females and known activity-related stresses on the spine. Osseous
changes normally associated with degenerative joint disease (osteoarthritis) of
the apophyseal facets and osteophytosis of the vertebral bodies were scored and
reported separately. Inter- and intrasite differences were found in the frequency
and distribution of osseous change down the spine. Overall, the Ensay sample was
more highly stressed than that from Wharram Percy. Furthermore, differences
between males and females at Ensay could be identified as relating to different
types of activities. Distinctions between males and females at Wharram Percy were
less marked, suggesting broadly similar lifestyles. These results accorded with
expectations regarding contrasting levels of activity-related stress at the two
sites and the division of labor between males and females. In particular, the
prevalence and distribution of facet remodeling, facet sclerosis/eburnation, and
osteophytosis in Ensay females could be related to load-bearing using creels (a
form of basket), which disrupted "normal" patterns of osseous change along the
spine. Importantly, morphologically distinct osseous modifications recorded on
the apophyseal facets produced dissimilar distributions, suggesting that they may
have different etiologies. These results highlight the need for a high degree of
discrimination in recording, analyzing, and exploring activity-related osseous
change.
PMID- 10685037
TI - A sequential developmental field defect of the vertebrae, ribs, and sternum, in a
young woman of the 12th century AD.
AB - Changes in the vertebral column are often noted in skeletal material.
Descriptions of these anomalies are often lacking, and their developmental
origins are not often discussed. The skeleton of a young woman from the medieval
cemetery of Tirup, in Denmark, has multiple defects of the axial skeleton,
including extra thoracic and lumbar vertebrae, border shifting, extra ribs, block
vertebra, and deformed sternum. This case study is particularly interesting
because of the number and diversity of anomalies seen; the rarity of these
defects, even in living populations; and her survival to adult age. Careful
analysis of the bones and use of the morphogenetic method of determining
development stages has led to the conclusion that the initial defect probably
occurred very early in development, during blastogenesis, with the initial
development of at least two extra somitomeres in the paraxial mesoderm. These
extra elements in turn led to problems in union and differentiation, and later
chondrification and ossification of the vertebra. The malformations of the
vertebrae also induced changes in the ribs and sternum. The initial error of
segmentation is identified as a developmental field defect, and the cascade of
anomalies seen is a developmental sequence caused by the initial field defect.
The genetic and environmental causes of developmental field defects are reviewed.
PMID- 10685038
TI - Tooth wear and compensatory modification of the anterior dentoalveolar complex in
humans.
AB - In populations living in environments where teeth wear severely, some
compensatory modification of the dentoalveolar complex is thought to occur during
life whereby functional occlusion is maintained as tooth substance is lost by
wear. This study investigates one aspect of this modification process: Changes in
the anterior dentoalveolar complex that are accompanied with wear were examined
in a series of Japanese skeletal samples. In the prehistoric Japanese hunter
gatherer population heavy wear occurs over the entire dentition. The following
changes were demonstrated to have occurred in the anterior segment of the
dentition accompanied by wear on the anterior teeth: The anterior teeth tip
lingually with wear up to a nearly upright position to fill in interproximal
spaces that would have been generated by wear, and to maintain contact relations
between adjacent teeth. At the same time, the anterior surface of the maxillary
alveolar process also inclines lingually to a certain extent. The amount of
lingual tipping is greater in the maxillary anterior teeth than in their
mandibular antagonists. It is because of this discrepancy that, with age, the
horizontal component of the overlap between maxillary and mandibular anterior
teeth decreases, and their bite form changes from scissor bite to edge-to-edge
bite. Lesser degrees of lingual tipping of the anterior teeth were also detected
in the prehistoric agriculturists and historic Japanese populations. The
variation in the degree of lingual tipping observed among the samples is
explained by inter-population variation in severity and pattern of tooth wear.
This and other evidence suggests that mechanisms that compensate for wear in the
anterior dentition may be characteristic of all living human populations,
independently of the degree of wear severity endured in their environments.
PMID- 10685039
TI - Krapina 1: a juvenile Neandertal from the early late Pleistocene of Croatia.
AB - The juvenile A Skull from Krapina, Croatia (Krapina 1) has been the subject of
considerable debate since B. Skerlj first suggested that it might not be a
Neandertal. Although widely known by its original designation, the Krapina A
Skull was recatalogued, along with all of the Krapina hominids, in the 1980's
(Radovcic, et al., [1988]. The Krapina Hominids: An Illustrated Catalog of
Skeletal Collection. Zagreb; Mladost). It is now catalogued as Krapina 1 in the
archives of the Hrvatski Prirodoslovni Muzej, Zagreb, Croatia. We present a
detailed, morphometric analysis of this specimen, comparing it to other Krapina
specimens, juvenile late Pleistocene hominids (including Neandertals), and
subadult recent humans. This analysis demonstrates that Krapina 1 possesses
morphological features that are primitive retentions; others that represent
derived Neandertal specializations; and still others that are typical for all
European late Pleistocene humans. Morphological features associated with the
browridges are intermediate between Neandertal and early modern European form.
Nevertheless, a thorough analysis of the morphology of this specimen, in
ontogenetic and regional contexts, leads to the conclusion that it cannot be
excluded from the Neandertal range of variation. We conclude that the most
parsimonious explanation for this 130 ka specimen is that it should be regarded
as a Neandertal.
PMID- 10685040
TI - Technical note: Stafne static mandibular bone defect-further expression on the
buccal aspect of the ramus.
AB - The anatomic distribution of the Stafne static mandibular bone defect (SSBD) is
extended with a description of a cavitation defect on the buccal ramus of the
mandible. The anatomical placement of SSBD thus correlates precisely with the
submandibular and parotid salivary glands, and gives further evidence that an
increase in major salivary gland size is associated with the defect. The global
latitudinal variation in the population prevalence of SSBD ranges from 10% in the
tropics to virtually 0% in most of the arctic. Globally the defect directly
correlates with parasite load and diversity, and may be a marker for of a history
of an environment with high levels of enteric macroparasite infestation.
PMID- 10685041
TI - Brief communication: a study of the predictive accuracy of mandibular ramus
flexure as a singular morphologic indicator of sex in an archaeological sample.
AB - Loth and Henneberg ([1996] Am J Phys Anthropol 99:473-485) assert that they have
discovered a single morphologic indicator of sexual dimorphism in the human
mandible that rivals the predictive accuracy of the complete pelvis at 94.2% for
all samples (99% for healthy samples). To test the accuracy of their method,
mandibles (n = 150) from the Tepe Hissar collection were assessed for the
presence or absence of mandibular ramus flexure. These results were then compared
to a separate sex assessment based on morphologic indicators from the
corresponding skull and innominates (where possible) to yield an overall accuracy
of only 78.2%. As a means of independent assessment, the mandibular results were
also compared with Krogman's ([1940] Racial Types from Tepe Hessar, Iran, from
late fifth to early second millennium, BC. Amsterdam: Koninkliijke Nederlandsche
Akademie van Wetenschappen) assessment of sex based on craniofacial measurements
and morphologic indicators from the skull. This comparison produced an even lower
accuracy of 67.2%. Such results question the predictive potential of mandibular
ramus flexure as a single indicator of sexual dimorphism and suggest caution when
applying this method, especially in the case of fragmentary forensic and fossil
remains.
PMID- 10685042
TI - Ligation and splicing of peptides and proteins.
PMID- 10685043
TI - Orthogonal ligation strategies for peptide and protein.
AB - This review focuses on the concept, criteria, and methods of an orthogonal amide
ligating strategy suitable for syntheses of peptides, peptide mimetics, and
proteins. Utilizing unprotected peptides or proteins derived from chemical or
biosynthetic sources, this ligation strategy has been shown to be general and
exceptionally mild. Its orthogonality in ligating two unprotected segments with
free N-terminal (NT)-amines at a specific NT-amine is achieved through a
chemoselective capture step and then an intramolecular acyl transfer reaction.
Both coupling reagents for enthalpic activation and protection schemes therefore
become unnecessary. More than a dozen orthogonal ligation methods based on either
imine or thioester captures have been developed to afford native and unusual
amino acids at ligation sites of linear, branched, or cyclic peptides. Because
unprotected peptides and proteins of different sizes and forms can be obtained
from either chemical or recombinant sources, orthogonal ligation removes the size
limitation imposed on the chemical synthesis of a protein with a native or non
native structure. Furthermore, by using building blocks from biosynthetic
sources, orthogonal ligation provides a unifying operational concept for both
total and semisynthesis of peptides and proteins.
PMID- 10685044
TI - Intein-mediated protein ligation: harnessing nature's escape artists.
AB - Inteins are naturally occurring proteins that are involved in the precise
cleavage and formation of peptide bonds in a process known as protein splicing.
Genetic engineering has allowed the controllable cleavage of peptide bonds at
either the N- or C-terminus of the intein. Inteins displaying controllable
cleavage have been used in the isolation of bacterially expressed proteins
possessing either a C-terminal thioester or an N-terminal cysteine. The specific
placement of these reactive groups has allowed either protein-protein or protein
peptide condensation through a native peptide bond. This review describes the
methods used to specifically generate these reactive groups on bacterially
expressed proteins and some applications of this technique, known as intein
mediated protein ligation. Furthermore, a versatile two intein (TWIN) system will
be described which enables the circularization and polymerization of bacterially
expressed proteins or peptides.
PMID- 10685045
TI - Introduction of unnatural amino acids into proteins using expressed protein
ligation.
AB - Here we describe the results of studies designed to explore the scope and
limitations of expressed protein ligation (EPL), a protein semisynthesis approach
that allows unnatural amino acids to be site specifically introduced into large
proteins. Using Src homology 3 domains from the proteins c-Abl and c-Crk as model
systems, we show here that EPL can be performed in the presence of moderate
concentrations of the chemical denaturant, guanidine hydrochloride, and the
organic solvent dimethylsulfoxide. Use of these solubilizing agents allowed the
successful preparation of two semisynthetic proteins, 10 and 12, both of which
could not be prepared using standard procedures due to the low solubility of the
synthetic peptide reactants in aqueous buffers. We also report the results of
thiolysis and kinetic studies which indicate that stable alkyl thioester
derivatives of recombinant proteins can be generated for storage and purification
purposes, and that 2-mercaptoethanesulfonic acid compares favorably with
thiophenol as the thiol cofactor for EPL reactions, while having superior
handling properties. Finally, we describe the semisynthesis of the
fluorescein/rhodamine-containing construct (12) and the ketone-containing
construct (14). The efficiency of these two syntheses indicates that EPL offers a
facile way of incorporating these important types of biophysical and biochemical
probes into proteins.
PMID- 10685046
TI - Characteristics of protein splicing in trans mediated by a semisynthetic split
intein.
AB - Protein splicing in trans results in the ligation of two protein or peptide
segments linked to appropriate intein fragments. We have characterized the trans
splicing reaction mediated by a naturally expressed, approximately 100-residue N
terminal fragment of the Mycobacterium tuberculosis intein and a synthetic
peptide containing the 38 C-terminal intein residues, and found that the splicing
reaction was very versatile and robust. The efficiency of splicing was nearly
independent of temperature between 4 and 37 degrees C and pH between 6.0 and 7.5,
with only a slight decline at pH values as high as 8.5. In addition, there was
considerable flexibility in the choice of the C-terminal intein fragment, no
significant difference in protein ligation efficiency being observed between
reactions utilizing the N-terminal fragment and either the naturally expressed
107-residue C-terminal portion of the intein, much smaller synthetic peptides, or
the 107-residue C-terminal intein fragment modified by fusion of a maltose
binding protein domain to its N-terminus. The ability to use different types of
the C-terminal intein fragments and a broad range of reaction conditions make
protein splicing in trans a versatile tool for protein ligation.
PMID- 10685047
TI - Synthesis of a three zinc finger protein, Zif268, by native chemical ligation.
AB - Protein synthesis by native chemical ligation has been an effective approach for
the synthesis of proteins of moderate size. The utility of this approach for
protein synthesis is demonstrated by the synthesis of a transcription factor, Zif
268 that contains three zinc finger domains. This synthesis highlights the
modular nature of the chemical ligation approach and the ability to synthesize,
handle and fold multiple domain proteins.
PMID- 10685048
TI - A pH-tunable peptide ligase.
AB - A chemical ligation system is reported, in which a highly acidic coiled-coil
peptide was used to template two basic peptide fragments and catalyze their
condensation, in a pH-tunable fashion, to generate a coiled-coil product. This
template showed a high catalytic efficiency (with single turnover) under neutral
conditions. Under acidic conditions, however, its catalytic efficiency was
reduced by approximately 4500-fold.
PMID- 10685049
TI - Synthesis, microbicidal activity, and solution structure of the dodecapeptide
from bovine neutrophils.
AB - The dodecapepetide sequence R-L-C-R-I-V-V-I-R-V-C-R with a disulfide bridge
between the cysteine residues found in bovine neutrophils was synthesized by
solid-phase procedures. Its antimicrobial activity against oral microorganisms
such as Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis,
Streptococcus mutans, and Streptococcus gordonii was examined, and its structural
features were examined by CD and determined by two-dimensional (2D) nmr. The
strains P. gingivalis (W50 and 381), A. actinomycetemcomitans (Y4 and 67), S.
gordonii (DL1), and S. mutans (GS5) are found to be highly sensitive to this
peptide at 2-2.5 microM concentrations, suggesting that the dodecapeptide is a
potent antibiotic for oral pathogens. The weak negative n-sigma* band observed at
approximately 265-270 nm in the CD spectra of this peptide provides evidence for
the presence of a disulfide bridge. The negative n-pi* band at approximately 200
nm and the positive pi-pi* band at 185 nm suggest a folded structure for this
peptide. The negative n-pi* shifts from 200 to 206 nm with an increase in
intensity in dipalmitoylphosphotidylcholine vesicles, suggesting that the peptide
might associate to form higher order aggregates in lipid medium. The assignment
of backbone and side-chain proton resonances has been accomplished by the
combined analysis of 2D total correlated and nuclear Overhauser effect
spectroscopy. The temperature dependence of amide NH chemical shifts and (1)H
(2)H exchange effect on amide NH resonances indicate the involvement of amide NH
groups of Cys3, Ile5, Ile8, Val10, and Arg12 in intramolecular hydrogen bonding.
The coupling constant (J(NH-C(alpha)H)) values, the set of medium-, short-, and
long-range nuclear Overhauser effects, and the results of restrained structure
calculation using the distance geometry algorithm for nmr applications provide
evidence for a folded, loop-like structure with a type I (III) beta-turn
involving Ile5, Val6, Val7, and Ile8, and two antiparallel beta-strands involving
the N-terminal Arg1, Leu2, Cys3, and Val4 and the C-terminal Arg9, Val10, Cys11,
and Arg12 residues. The structure of the dodecapeptide mimics the amphiphilic
structure of large 30-35 residue defensins and the peptide appears to exhibit
similar antimicrobial potency.
PMID- 10685050
TI - Osmolyte-induced changes in protein conformational equilibria.
AB - Examining solute-induced changes in protein conformational equilibria is a long
standing method for probing the role of water in maintaining protein stability.
Interpreting the molecular details governing the solute-induced effects, however,
remains controversial. We present experimental and theoretical data for osmolyte
induced changes in the stabilities of the A and N states of yeast iso-1
ferricytochrome c. Using polyol osmolytes of increasing size, we observe that
osmolytes alone induce A-state formation from acid-denatured cytochrome c and N
state formation from the thermally denatured protein. The stabilities of the A
and N states increase linearly with osmolyte concentration. Interestingly,
osmolytes stabilize the A state to a greater degree than the N state. To
interpret the data, we divide the free energy for the reaction into contributions
from nonspecific steric repulsions (excluded volume effects) and from binding
interactions. We use scaled particle theory (SPT) to estimate the free energy
contributions from steric repulsions, and we estimate the contributions from
water-protein and osmolyte-protein binding interactions by comparing the SPT
calculations to experimental data. We conclude that excluded volume effects are
the primary stabilizing force, with changes in water-protein and solute-protein
binding interactions making favorable contributions to stability of the A state
and unfavorable contributions to the stability of the N state. The validity of
our interpretation is strengthened by analysis of data on osmolyte-induced
protein stabilization from the literature, and by comparison with other analyses
of solute-induced changes in conformational equilibria.
PMID- 10685051
TI - Similarities in the HIV-1 and ASV integrase active sites upon metal cofactor
binding.
AB - The HIV-1 integrase, which is essential for viral replication, catalyzes the
insertion of viral DNA into the host chromosome thereby recruiting host cell
machinery into making viral proteins. It represents the third main HIV enzyme
target for inhibitor design, the first two being the reverse transcriptase and
the protease. We report here a fully hydrated 2 ns molecular dynamics simulation
performed using parallel NWChem3.2.1 with the AMBER95 force field. The HIV-1
integrase catalytic domain previously determined by crystallography (1B9D) and
modeling including two Mg(2+) ions placed into the active site based on an
alignment against an ASV integrase structure containing two divalent metals
(1VSH), was used as the starting structure. The simulation reveals a high degree
of flexibility in the region of residues 140-149 even in the presence of a second
divalent metal ion and a dramatic conformational change of the side chain of E152
when the second metal ion is present. This study shows similarities in the
behavior of the catalytic residues in the HIV-1 and ASV integrases upon metal
binding. The present simulation also provides support to the hypothesis that the
second metal ion is likely to be carried into the HIV-1 integrase active site by
the substrate, a strand of DNA.
PMID- 10685052
TI - Physicochemical characterization of generation 5 polyamidoamine dendrimers.
AB - The dispersity, size, and self-interaction of generation 5 polyamidoamine
dendrimeric polymers with different terminal groups (surfaces) were characterized
using several physicochemical techniques. Amino-surface dendrimers form
oligomeric aggregates in aqueous solution, even in the presence of high salt
concentrations (0.6M sodium phosphate). In contrast, the hydroxyl-surface polymer
G5-OH behaves as a single homogeneous (or paucidisperse) species at low
concentration. Measurements of density increment and the sedimentation and
diffusion coefficients of G5-OH suggest a more swollen, porous structure than a
globular protein of comparable mass. Measurements of the concentration dependence
of sedimentation equilibrium of G5-OH in pH 7.2 phosphate buffer indicate the
presence of significant electrostatic repulsion overlaid on weakly attractive
interactions, leading to the formation of nonspecific aggregates at sufficiently
high dendrimer concentration.
PMID- 10685053
TI - Condensation of DNA by multivalent cations: experimental studies of condensation
kinetics.
AB - DNA in viruses and cells exists in highly condensed, tightly packaged states. We
have undertaken an in vitro study of the kinetics of DNA condensation by the
trivalent cation hexaammine cobalt (III) with the aim of formulating a
quantitative, mechanistic model of the condensation process. Experimental
approaches included total intensity and dynamic light scattering, electron
microscopy, and differential sedimentation. We determined the average degree of
condensation, the distribution of condensate sizes, and the fraction of
uncondensed DNA as a function of reaction time for a range of [DNA] and
[Co(NH(3))(3+)(6)]. We find the following: (1) DNA condensation occurs only above
a critical [Co(NH(3))(3+)(6)] for a given DNA and salt concentration. At the
onset of condensation, [Co(NH(3))(3+)(6)]/[DNA-phosphate] is close to the average
value of 0.54, which reflects the 89-90% charge neutralization criterion for
condensation. (2) The equilibrium weight average hydrodynamic radius of
the condensates first decreases, then increases with increasing
[Co(NH(3))(3+)(6)] as they undergo a transition from intramolecular
(monomolecular) to intermolecular (multimolecular) condensation. However,
is insensitive to [DNA]. (3) The uncondensed DNA fraction decays approximately
exponentially with time. The equilibrium uncondensed DNA fraction and relaxation
time decrease with increasing [Co(NH(3))(3+)(6)] but are insensitive to [DNA].
(4) The condensation rate in its early stages is insensitive to [DNA] but
proportional to [Co(NH(3))(3+)(6)](xs) = [Co(NH(3))(3+)(6)] -
[Co(NH(3))(3+)(6)](crit). (5) Data for low [DNA] and low [Co(NH(3))(3+)(6)] at
early stages of condensation are most reliable for kinetic modeling since under
these conditions there is minimal clumping and network formation among separate
condensates. A mechanism with initial monomolecular nucleation and subsequent
bimolecular association and unimolecular dissociation steps with rate constants
that depend on the number of DNA molecules in the condensate, accounts reasonably
well for these observations.
PMID- 10685054
TI - Low frequency vibrations and structural characterization of a murine IgG2a
monoclonal antibody studied by raman and IR spectroscopies.
AB - The Raman and ir spectra of a murine IgG2a monoclonal antibody molecule are
reported. In accordance with previous studies on immunoglobulins, the secondary
structure is predominantly of the beta-sheet type. The low frequency region of
the Raman spectrum was also analyzed in detail. A structured band with two maxima
near 43 and 94 cm(-1) was observed. This band has been attributed to vibrations
of elastic body. The results are interpreted using a simple elastic model.
PMID- 10685055
TI - Sequence-specific liquid crystallinity of collagen model peptides. I.
Transmission electron microscopy studies of interfacial collagen gels.
AB - The conformation, crystal structure and self-assembly behavior of three peptides
with collagen-like repetitive sequences [(1) peptide GAPGPP: (Glu)(5)(Gly-Ala-Pro
Gly-Pro-Pro)(6)(Glu)(5); (2) peptide GVPGPP: (Glu)(5)(Gly-Val-Pro-Gly-Pro
Pro)(6)(Glu)(5); and (3) peptide GAPGPA: (Glu)(5)(Gly-Ala-Pro-Gly-Pro
Ala)(6)(Glu)(5)] were compared. The peptides were characterized using
transmission electron microscopy, electron diffraction, environmental scanning
electron microscopy, and Fourier transform ir spectroscopy in order to determine
how the molecular geometry dictated by each sequence affects the spontaneous
generation of long-range ordered structures. Samples of each peptide, at ambient
temperature and at 5 degrees C, were examined as films dried from aqueous
solution, air-water interfacial films, and chloroform-water interfacial films.
Peptide GAPGPP prepared at 5 degrees C and dried from bulk solution was found to
have a collagen-like triple-helical structure. A sinusoidally textured gel,
suggestive of cholesteric behavior was observed for peptides GAPGPP and GVPGPP at
the aqueous chloroform interface at 5 degrees C. Peptide GAPGPA also formed a
gel, but less reproducibly and the sinusoidal texture was not as well defined.
The periodicities of the sinusoidal textures were reproducibly 10 microm for
peptide GAPGPP, 7 microm for peptide GVPGPP, and 6 microm for peptide GAPGPA. The
differences in the periodicity of the banded structure and in the crystallization
behavior of the three peptides is attributed to differences in the symmetry of
the preferred packing arrangement for each peptide, as evidenced by electron
diffraction from crystallites that coexist with the sinusoidal gel. These
differences are believed to be a measure of the effective symmetry and shape of
the molecular cross section.
PMID- 10685056
TI - Foreword
PMID- 10685057
TI - Vascular pathology: a pathogenetic challenge for a new millennium.
PMID- 10685058
TI - Atherosclerosis, inflammation, and infection.
AB - In recent years, it has been shown that inflammation plays an important role in
the pathogenesis of atherosclerosis. Activated macrophages, T lymphocytes, and
mast cells are present in atherosclerotic plaques, which has led to the notion
that the inflammatory response is an immune-mediated process. Complicated
lesions, moreover, appear to be associated with an increase in the amount of the
inflammatory response and in these patients, increased levels of acute phase
proteins are present. The appreciation that atherosclerosis is an immune-mediated
inflammatory disease has also led to renewed interest in the potential role of
infectious agents in initiating or modulating atherosclerosis.
Seroepidemiological studies have shown raised antibody titres against several
micro-organisms. However, as yet, there are hardly any data available that
provide a sound scientific basis for an infectious origin. Of all potential
candidate organisms, Chlamydia pneumoniae appears as the one most likely involved
in atherogenesis. C. pneumoniae has been retrieved from atherosclerotic tissues;
the level of raised plasma titres correlates with the severity of symptomatic
atherosclerotic disease; and the incidence of C. pneumoniae-responsive T cells in
peripheral blood is increased in patients with coronary heart disease. It also
appears that in some patients T cells generated from atherosclerotic plaques
respond to C. pneumoniae. At the present state of knowledge, however, it is fair
to state that the relationship between infection, intraplaque inflammation, and
atherosclerosis still remains hypothetical, despite the increasing evidence that
such a relationship could exist.
PMID- 10685059
TI - Nitric oxide in the pathogenesis of vascular disease.
AB - Nitric oxide (NO) is synthesized by at least three distinct isoforms of NO
synthase (NOS). Their substrate and cofactor requirements are very similar. All
three isoforms have some implications, physiological or pathophysiological, in
the cardiovascular system. The endothelial NOS III is physiologically important
for vascular homeostasis, keeping the vasculature dilated, protecting the intima
from platelet aggregates and leukocyte adhesion, and preventing smooth muscle
proliferation. Central and peripheral neuronal NOS I may also contribute to blood
pressure regulation. Vascular disease associated with hypercholesterolaemia,
diabetes, and hypertension is characterized by endothelial dysfunction and
reduced endothelium-mediated vasodilation. Oxidative stress and the inactivation
of NO by superoxide anions play an important role in these disease states.
Supplementation of the NOS substrate L-arginine can improve endothelial
dysfunction in animals and man. Also, the addition of the NOS cofactor (6R)
5,6,7, 8-tetrahydrobiopterin improves endothelium-mediated vasodilation in
certain disease states. In cerebrovascular stroke, neuronal NOS I and cytokine
inducible NOS II play a key role in neurodegeneration, whereas endothelial NOS
III is important for maintaining cerebral blood flow and preventing neuronal
injury. In sepsis, NOS II is induced in the vascular wall by bacterial endotoxin
and/or cytokines. NOS II produces large amounts of NO, which is an important
mediator of endotoxin-induced arteriolar vasodilatation, hypotension, and shock.
PMID- 10685060
TI - Pathophysiology of ischaemia-reperfusion injury.
AB - Reperfusion of ischaemic tissues is often associated with microvascular
dysfunction that is manifested as impaired endothelium-dependent dilation in
arterioles, enhanced fluid filtration and leukocyte plugging in capillaries, and
the trafficking of leukocytes and plasma protein extravasation in postcapillary
venules. Activated endothelial cells in all segments of the microcirculation
produce more oxygen radicals, but less nitric oxide, in the initial period
following reperfusion. The resulting imbalance between superoxide and nitric
oxide in endothelial cells leads to the production and release of inflammatory
mediators (e.g. platelet-activating factor, tumour necrosis factor) and enhances
the biosynthesis of adhesion molecules that mediate leukocyte-endothelial cell
adhesion. Some of the known risk factors for cardiovascular disease
(hypercholesterolaemia, hypertension, and diabetes) appear to exaggerate many of
the microvascular alterations elicited by ischaemia and reperfusion (I/R). The
inflammatory mediators released as a consequence of reperfusion also appear to
activate endothelial cells in remote organs that are not exposed to the initial
ischaemic insult. This distant response to I/R can result in leukocyte-dependent
microvascular injury that is characteristic of the multiple organ dysfunction
syndrome. Adaptational responses to I/R injury have been demonstrated that allow
for protection of briefly ischaemic tissues against the harmful effects of
subsequent, prolonged ischaemia, a phenomenon called ischaemic preconditioning.
There are two temporally and mechanistically distinct types of protection
afforded by this adaptational response, i.e. acute and delayed preconditioning.
The factors (e.g. protein kinase C activation) that initiate the acute and
delayed preconditioning responses appear to be similar; however the protective
effects of acute preconditioning are protein synthesis-independent, while the
effects of delayed preconditioning require protein synthesis. The published
literature in this field of investigation suggests that there are several
potential targets for therapeutic intervention against I/R-induced microvascular
injury.
PMID- 10685061
TI - The role of apoptosis in vascular disease.
AB - Normal arteries are characterized by a low turnover of endothelial (EC) and
smooth muscle cells (SMC). Different mechanisms protect the EC and SMC against
apoptosis in the normal artery. In hypertension, SMC replication is increased but
this is not counterbalanced by increased apoptosis, resulting in thickening of
the media of arteries and arterioles. The significance of apoptosis in
atherosclerosis depends on the stage of the plaque, localization and the cell
types involved. Both macrophages and SMC undergo apoptosis in atherosclerotic
plaques. Apoptosis of macrophages is mainly present in regions showing signs of
DNA synthesis/repair. SMC apoptosis is mainly present in less cellular regions
and is not associated with DNA synthesis/repair. Even in the early stages of
atherosclerosis SMC become susceptible to apoptosis since they increase different
pro-apoptotic factors. Moreover, recent data indicate that SMC may be killed by
activated macrophages. The loss of the SMC can be detrimental for plaque
stability since most of the interstitial collagen fibres, which are important for
the tensile strength of the fibrous cap, are produced by SMC. Apoptosis of
macrophages could be beneficial for plaque stability if apoptotic bodies were
removed. Apoptotic cells that are not scavenged in the plaque activate thrombin,
which could further induce intraplaque thrombosis. It can be concluded that
apoptosis in primary atherosclerosis is detrimental since it could lead to plaque
rupture and thrombosis. Recent data of our group indicate that apoptosis
decreased after lipid lowering which could be important in the understanding of
the cell biology of plaque stabilization.
PMID- 10685062
TI - Molecular mechanisms that control endothelial cell contacts.
AB - Endothelial cell contacts control the permeability of the blood vessel wall. This
allows the endothelium to form a barrier for solutes, macromolecules, and
leukocytes between the vessel lumen and the interstitial space. Loss of this
barrier function in pathophysiological situations can lead to extracellular
oedema. The ability of leukocytes to enter tissue at sites of inflammation is
dependent on molecular mechanisms that allow leukocytes to adhere to the
endothelium and to migrate through the endothelial cell layer and the underlying
basal lamina. It is a commonly accepted working hypothesis that inter-endothelial
cell contacts are actively opened and closed during this process. Angiogenesis is
another important process that requires well-controlled regulation of inter
endothelial cell contacts. The formation of new blood vessels by sprouting from
pre-existing vessels depends on the loosening of established endothelial cell
contacts and the migration of endothelial cells that form the outgrowing sprouts.
This review focuses on the molecular composition of endothelial cell surface
proteins and proteins of the cytoskeletal undercoat of the plasma membrane at
sites of inter-endothelial cell contacts and discusses the current knowledge
about the potential role of such molecules in the regulation of endothelial cell
contacts.
PMID- 10685063
TI - Improving vascular grafts: the importance of mechanical and haemodynamic
properties.
AB - In the last 40 years, as techniques and materials have improved, the success rate
of vascular prostheses with a diameter greater than 6mm has risen steadily, 5
year survival rates exceeding 95% in most centres. With smaller grafts no
comparable improvement has occurred, the majority failing within 5 years, usually
as a result of intimal hyperplasia and, ultimately atherosclerosis, in and around
the downstream anastomosis. Clinical evidence suggests that the patency rates of
small grafts are improved by matching the elastic properties of the graft to that
of the artery into which it is placed. Although there is little reliable evidence
that 'elastic mismatch' per se is the cause of intimal hyperplasia, it is
generally accepted that mechanical factors are important in its genesis. These
include disturbed flow at the anastomosis leading to fluctuations in shear stress
at the endothelium (a known cause of intimal hyperplasia in normal arteries),
injury due to suturing and stress concentration at the anastomosis. Few suitable
materials or techniques have yet been developed to improve the long-term survival
rates of small grafts. Recent advances in tissue engineering in which prostheses
are manufactured by culturing vascular smooth muscle cells on a tubular scaffold
of biodegradable polymer may ultimately make it possible to manufacture
biologically and haemodynamically compatible grafts with diameters as small as
1mm.
PMID- 10685064
TI - Molecular mechanisms in intimal hyperplasia.
AB - Intimal hyperplasia is the process by which the cell population increases within
the innermost layer of the arterial wall, such as occurs physiologically during
closure of the ductus arteriosus and during involution of the uterus. It also
occurs pathologically in pulmonary hypertension, atherosclerosis, after
angioplasty, in transplanted organs, and in vein grafts. The underlying causes of
intimal hyperplasia are migration and proliferation of vascular smooth muscle
cells provoked by injury, inflammation, and stretch. This review discusses, at a
molecular level, both the final common pathways leading to smooth muscle
migration and proliferation and their (patho)-physiological triggers. It
emphasizes the key roles played by growth factors and extracellular matrix
degrading metalloproteinases, which act in concert to remodel the extracellular
matrix and permit cell migration and proliferation.
PMID- 10685065
TI - Interactions between cancer cells and the endothelium in metastasis.
AB - The haematogenous phase of cancer metastasis facilitates the transport of
metastatic cells within the blood and incorporates a sequence of interactions
between circulating intravascular cancer cells and the endothelium of blood
vessels at the sites of tumour cell arrest. Initial interactions involve
mechanical contact and transient adhesion, mediated by endothelial selectins and
their ligands on the neoplastic cells. This contact initiates a sequence of
activation pathways that involves cytokines, growth factors, bioactive lipids,
and reactive oxygen species produced by either the cancer cell or the
endothelium. These molecules elicit expression of integrin adhesion molecules in
cancer cells and the endothelium, matrix metalloproteinases, and chemotactic
factors that promote the attachment of tumour cells to the vessel wall and/or
transvascular penetration. Induction of endothelial free radicals can be
cytotoxic to cancer cells. Collectively, the sum of these interactions
constitutes an interdependent relationship, the outcome of which determines the
fate of the metastatic process.
PMID- 10685066
TI - The clinical manipulation of angiogenesis: pathology, side-effects, surprises,
and opportunities with novel human therapies.
AB - The first phase of angiogenesis research has provided knowledge of the basic
pathobiology of angiogenesis and its manipulation in models, mouse, and man. The
first line of therapeutic substances has been devised and is now in clinical
trials. New lessons are being learned from clinical observations. Unexpected side
effects are being noted, particularly affecting the nervous system. Other side
effects may be anticipated from a sound knowledge of clinical pathology and
recognition of the commonality of angiogenesis to multiple disease mechanisms,
but these may be tolerable or avoidable. Angiogenesis researchers await further
feedback and ideas from the clinic to stimulate the next phase of basic and
applied research.
PMID- 10685067
TI - The pathophysiology of the collateral circulation (arteriogenesis).
AB - Since the mid 1980s a new strategy is coming from bench to bedside termed
angiogenesis. This process involves sprouting of capillaries and finally results
in newly developed microvessels which belong to the capillary level. Importantly
these newly formed capillary tubes lack vascular smooth muscle cells, they are
not surrounded by mural cells and are fragile and prone to rupture. Therefore
these networks remain susceptible to hypoxic regulation, fail to become
remodelled and are unable to sustain proper circulation: they cannot adapt to
changes in physiological demands of blood supply. Since atherosclerosis affects
large conductance arteries, capillary sprouting from compromised vessels cannot
provide an adequate supply of blood flow to the endangered tissue. However, the
body provides a natural system of pre-existing collateral arteries, which may
bypass sites of arterial occlusion. These vessels can dramatically increase their
lumen by growth so as to provide enhanced perfusion to the jeopardized ischaemic
regions. This process - termed arteriogenesis - finally results in fully
functional and structurally normal arteries which can ameliorate the ensuing
detrimental effects of vessel obstruction in many regions of the body. Hallmarks
of arteriogenesis are increased levels of shear forces (rather than ischaemia),
the invasion of circulating monocytes (and their pluripotent precursors), and the
substrates of arteriogenesis are pre-existing collateral arterioles.
PMID- 10685068
TI - Regulation of inflammatory vascular damage.
AB - The acute inflammatory response is comprised of an elaborate cascade of mediators
that control an ordered sequence of events resulting in the recruitment of
neutrophils to the site of infection or injury. Microvascular injury occurring
during acute inflammation often results in increased vascular permeability and
microvascular haemorrhage. Damage to vascular endothelial cells, basement
membrane, and matrix components results from both neutrophil-dependent and
neutrophil-independent mechanisms and is also dependent on the organ/tissue
source of the endothelial cells. Neutrophil-mediated injury of endothelial cells
involves a complex cascade in which products from both cell types affect the
cytotoxic outcome. It is also clear that the acute inflammatory response is
carefully regulated by the endogenous gene expression of both pro-inflammatory
and anti-inflammatory mediators. Control of acute inflammation seems to relate to
activation of the transcription factor NFkappaB. To appreciate the
interrelationship between multiple contributing factors of inflammatory vascular
injury, one must first have an understanding of the inflammatory mediator
cascades which bring about the recruitment of neutrophils to the site of
inflammation. In this review it is discussed how inflammatory mediators, as well
as the products of activated neutrophils, affect the outcome of the acute
inflammatory response.
PMID- 10685069
TI - Pathogenesis of ANCA-associated systemic vasculitis.
AB - The aetiology of primary systemic vasculitides remains unknown. Recent advances
have been made in the understanding of relevant mechanisms of inflammation,
particularly the role of the endothelium and interactions with inflammatory
mediators and immune effector cells. In Wegener's granulomatosis and microscopic
polyangiitis the evidence suggests an autoimmune inflammatory process,
characterized by an early lesion involving neutrophils and endothelial cells as
both targets and active participants; priming of neutrophils and endothelial
cells allows ANCA to activate neutrophils with damage localized to the
endothelium. In the absence of immune complex deposition, the role of the ANCA is
particularly intriguing. Endothelial cell damage and activation produces pro
inflammatory mediators with influx monocytes and T cells intensifying damage.
Increased understanding of the pathogenesis of systemic vasculitis is likely to
provide the basis for the use of more selective immunomodulatory therapies in the
future.
PMID- 10685070
TI - Vascular protease receptors: integrating haemostasis and endothelial cell
functions.
AB - The endothelium plays a crucial dynamic role as a protective interface between
blood and the underlying tissues during the haemostatic process, which maintains
blood flow in the circulation and prevents life-threatening blood loss. Following
vessel wall injury with initial platelet adhesion and aggregation to exposed
subendothelial extracellular matrix, the initiation, amplification, and control
of haemostasis depend on structurally unrelated membrane-associated receptors for
blood coagulation proteases including tissue factor, G-protein-coupled protease
activatable receptors, thrombomodulin, and protein C receptor, respectively. In
addition to their regulatory role in haemostasis, the respective (pro-)enzyme
ligands such as Factors VIIa and Xa, thrombin or protein C mediate specific
signalling pathways in vascular cells related to migration, proliferation or
adhesion. The functional importance of these receptors beyond haemostasis has
been manifested by various lethal and pathological phenotypes in knock-out mice.
These protease receptors thereby provide important molecular links in the
vascular system and serve to integrate haemostasis with endothelial cell
functions which are relevant for the (patho-)physiological responses to injury or
inflammatory challenges.
PMID- 10685071
TI - Microcirculatory dysfunction in sepsis: a pathogenetic basis for therapy?
AB - Sepsis is a frequent complication of multiple organ dysfunction syndrome and
remains a major problem of intensive care medicine. It is also a common factor in
the final cause of death in hospital populations. Clinical observations, assisted
by invasive monitoring techniques as well as pathological-anatomical studies,
clearly indicate that microcirculatory dysfunction lies at the centre of sepsis
pathogenesis. Numerous animal models, from rodents to primates, many of which
employ bacteria or their toxins, especially endotoxins, have helped to shed light
on the pathomechanisms leading to this dysregulation in the peripheral
circulation. Among these are activation of humoral and cellular inflammatory
mediator systems, with special emphasis on neutrophil-endothelial interactions,
affecting endothelial barrier function and vasoregulation and ultimately leading
to severely perturbed oxygen transport and utilization. In vitro studies have
provided more insight into the molecular mechanisms involved in this
microcirculatory dysfunction, although much more attention must be directed
towards microvascular endothelial cells and the role of heterogeneity of response
in various vascular beds. These experimental data must in turn be validated by
comparing with the human in situ situation, both clinical and morphological. This
review aims at a critical appraisal of the clinical and experimental evidence for
sepsis-induced dysregulation of the microcirculation and how knowledge of the
underlying cellular and molecular pathology could be used to make therapy more
rational and effective. To date, therapeutic approaches, such as anti-cytokine
and anti-oxidant regimens, which have been highly successful in experimental
models, have failed to demonstrate clinical efficacy. Newer approaches, such as
targeting the coagulation system, nitric oxide synthesis or intracellular signal
transduction, are also discussed. The necessity to focus on the role of anti
inflammatory mediators, as well as the pathogenetic significance of important
molecular groups, such as the heat shock proteins, which until now have been
given scant attention, will be stressed.
PMID- 10685072
TI - Transgenic mouse models in angiogenesis and cardiovascular disease.
AB - Novel gene technologies have allowed us to manipulate the genetic balance of
candidate molecules in mice in a controllable manner. Homologous or site-specific
recombination in embryonic stem cells allows us to study the consequences of
deficiencies, mutations, and conditional or tissue-specific expression of gene
products in transgenic mice. These technological breakthroughs have significantly
advanced biomedical research and broadened our understanding of the
pathophysiological role of candidate disease genes. In addition, gene transfer
allows us to test the possible therapeutic use of gene products for gene therapy.
A variety of assays have been miniaturized, allowing analysis of cardiovascular
physiology in the mouse. With the advent of genome sequencing programmes, these
gene technologies provide means of studying gene function in a conclusive manner.
Furthermore, disease models can be generated which can be used as test models for
(gene) therapy or for the discovery of novel genes using differential gene
profiling techniques. The present review will focus on the molecular basis of how
blood vessels form (angiogenesis and arteriogenesis) and how they become
diseased. A selected number of molecules that have been studied in the authors'
laboratory will be reviewed in more detail.
PMID- 10685073
TI - Cytometric quantification of nitrate reductase by immunolabeling in the marine
diatom Skeletonema costatum.
AB - BACKGROUND: The uptake of nitrate by phytoplankton is a central issue in
biological oceanography due to its importance to primary production and vertical
flux of biogenic carbon. Nitrate reductase catalyzes the first step of nitrate
assimilation, the reduction of NO(3) to NO(2). A cytometric protocol to detect
and quantify relative changes in nitrate reductase (NR) protein content of the
marine centric diatom Skeletonema costatum is presented. METHODS: Immunolabeling
of NR protein was achieved with polyclonal antibodies raised against S.costatum
NR. Antisera specific to a NR protein subunit and to a NR polypeptide sequence
were compared, and cytometric results of NR protein abundance were related to
Western analyses. Changes in cellular NR abundance and activity were followed
during an upwelling simulation experiment in which S. costatum was exposed to a
shift from ammonia to nitrate as major nitrogen source. RESULTS: NR protein could
be detected in NO(3)-grown cells and at extremely low levels hardly discernible
by Western Blot densiometry in NH(4)-grown cells. The protocol allowed
observation of early stages of NR induction during an upwelling simulation. NR
abundance increased after the nutrient shift to reach a new physiological "steady
state" 96 hrs later. NR activity exhibited diel variation with maxima at mid-day.
NR abundance as estimated by both flow cytometry and Western analysis exhibited a
hyperbolic relationship to NR activity. This pattern suggests post-translational
activation of NR protein. CONCLUSIONS: The presented protocol allows the
differentiation of NH(4)- versus NO(3)-grown algae as well as the monitoring of
early stages in the induction of nitrate assimilatory capacities.
PMID- 10685074
TI - On the use of the Kolmogorov-Smirnov statistical test for immunofluorescence
histogram comparison.
AB - BACKGROUND: The problem considered is the quantitative comparison of
immunofluorescence frequency distributions in order to detect their differences
of biological significance, i.e., to evaluate the potential positivity of a cell
sample with respect to negative control cells. The Kolmogorov-Smirnov (KS)
statistical test, proposed in the literature for this purpose, is examined and
discussed through its application to a set of experimental measurements. It is
shown that even differences due to the stain procedure or to instrumental biases
may be considered significant by the test implemented in the standard form.
METHODS: In order to ensure valid results, it is necessary to take into account
the various sources of variation in the specific experimental context. A
procedure is proposed that uses the KS statistics as a reference for determining
an appropriate estimate of the overall variability in the control data. This
estimate is derived from the comparisons of the cumulative distributions
associated with repeated measurements of the negative cell sample. RESULTS AND
CONCLUSIONS: The KS-related index thus defined provides a tool for assessing the
potential positivity of a cell sample, since it allows to distinguish between
statistical and biological significance of the difference between the histogram
to be tested and the set of control data. In particular, if a cell sample is not
included in the control variability, either a positive cell subpopulation is
present, or all cells are positive. Instead, for a sample included in the control
variability, the difference will be not biologically meaningful, even if
statistically significant. Moreover, when a purely positive control sample is
also available, it is possible to derive a measure of the precision at which a
true biological positivity can be detected. Finally, since the index is not
absolute, but relative to the features of the instrumentation, of the antibodies
and of the fluorochromes used, it represents a quantitative measure of the
stability and reproducibility of the measurement process and could be used for
quality control of flow cytometric experiments in immunofluorescence.
PMID- 10685075
TI - Differential production of IFN-gamma, analyzed at the single-cell level, by
specific subsets of human NK and T cells from healthy and HIV(+) subjects.
AB - BACKGROUND: Interferon gamma is a cytokine that plays a central role in immunity,
and is physiologically secreted by T and NK cells under appropriate stimuli
during the immune response. By means of flow cytometry, we performed a single
cell analysis of interferon gamma producing NK cells and their surface phenotype
in normal and HIV(+) individuals that show several defects of cytokine production
and cellular immunity. METHODS: PBMC or purified NK cells were stimulated for 1
12 h with PMA/ionomycin in the presence of monensin, subsequently stained for
surface CD56 and CD3 or CD8, and for intracytoplasmic IFN-gamma, and analysed by
flow cytometry. RESULTS: Our results show that CD56(+) NK cells are more
efficient interferon gamma producers than T cells. Moreover, within the CD56(+)
NK cell population, those that co-express low density CD8 are the best producers.
Finally, we show that NK cells during HIV infection are more massively recruited
to interferon gamma production than those from normal subjects. CONCLUSIONS: Both
in the normal and HIV(+) subjects, a higher percentage of NK cells than T cells
can produce IFN-gamma although differences can be identified within the NK cells
subset in terms of IFN-gamma production. The production of IFN-gamma is fully
achievable in the HIV(+) subjects, which is consistent with their elevated
plasmatic levels of the cytokine. The possibility that NK cells that produce
interferon gamma could represent a functionally distinct population committed to
the production of this cytokine, is discussed.
PMID- 10685076
TI - Flow cytometric evaluation of fas expression in relation to response and
resistance to anthracyclines in leukemic cells.
AB - BACKGROUND: Cell chemosensitivity to cytotoxic drugs has been attributed to their
ability to trigger apoptosis. The emergence of resistance in drug-exposed cells
is often characterized by the appearance of drug efflux mechanisms including P-gp
transport. Nevertheless, mdr1 expression may coexist with other resistance
features, in particular those interfering with apoptotic signaling pathways.
METHODS: Leukemic cell lines cultured in a progressively toxic environment were
analyzed for Fas and P-gp expression by immunostaining and flow cytometry. Their
mdr1 mRNA expression level was determined by reverse transcriptase-polymerase
chain reaction (RT-PCR), and their apoptotic response was microscopically
evaluated. Activation of the Fas pathway was obtained by cross-linking the Fas
receptor with the 7C11 anti-Fas agonist. RESULTS: We demonstrate a dose-dependent
Fas overexpression after short-term (18 h) incubation with daunorubicin. The
subsequent sensitization to Fas activators led to a significant increase in the
apoptotic response induced by 7C11. After long-term exposure to daunorubicin and
acquisition of drug resistance, expression of P-gp was accompanied by a decrease
in the number of Fas sites at the cell surface with a correlated desensitization
to Fas-induced apoptosis. Additional alterations in the Fas signaling pathway can
also be hypothesized in the most resistant Jurkat cell line. CONCLUSIONS: The
induction of Fas expression could be one of the mechanisms of action of
chemotoxic drugs and thus might enhance the cell susceptibility to Fas-mediated
apoptosis. On the contrary, the emergence of the multidrug resistance phenotype
is associated with a down-regulation of Fas expression and possible defects in
the Fas signaling pathway.
PMID- 10685078
TI - KRN5500, a novel antitumor agent, induces apoptosis or cell differentiation in HL
60 cells.
AB - BACKGROUND: KRN5500, a derivative of spicamycin, shows antitumor activity against
a variety of tumor cell lines. However, the mechanism of cytotoxic action has
remained unclear. METHODS: The viability of HL-60 human leukemic cells treated
with KRN5500 was studied by the dye exclusion assay. Induction of apoptosis and
effects on the cell cycle were investigated by flow cytometry: We measured
cellular DNA content after extraction of fragmented DNA, and apoptosis-induced
DNA strand breaks. Cell morphology was observed by light microscopy. DNA strand
breaks at a nucleosomal unit were analyzed by electrophoresis. RESULTS: Our data
demonstrated that KRN5500 caused inhibition of cell growth, and that apoptosis
was the mode of cell death. G(1) phase cells were more susceptible to KRN5500
induced apoptosis. In addition, KRN5500 induced cell differentiation at lower
concentration. CONCLUSIONS: It is anticipated that KRN5500 will be used
clinically as an anti-leukemic agent. Its mechanism of antitumor action is to
induce apoptosis or cell differentiation.
PMID- 10685077
TI - Staining of mitochondrial membranes with 10-nonyl acridine orange, MitoFluor
Green, and MitoTracker Green is affected by mitochondrial membrane potential
altering drugs.
AB - BACKGROUND: We set out to develop an assay for the simultaneous analysis of
mitochondrial membrane potential and mass using the probes 10-nonyl acridine
orange (NAO), MitoFluor Green (MFG), and MitoTracker Green (MTG) in HL60 cells.
However, in experiments in which NAO and MFG were combined with orange emitting
mitochondrial membrane potential (DeltaPsi(m)) probes, we found clear responses
to DeltaPsi(m) altering drugs for both probes. METHODS: The three probes were
titrated to determine whether saturation played a role in the response to drugs.
The effects of a variety of DeltaPsi(m) altering drugs were tested for MFG and
MTG at probe concentrations of 20 nM and 200 nM and for NAO at 0.1 microM and 5
microM, using rhodamine 123 at 0.1 microM as a reference probe. RESULTS:
Incubation of GM130, HL60, and U937 cells with 2,3-butanedione monoxime (BDM),
nigericin, carbonyl cyanide 3-chlorophenylhydrazone (CCCP), carbonyl cyanide p
(trifluoromethoxy)phenylhydrazone (FCCP), 2,4-dinitrophenol (DNP), gramicidin,
ouabain, and valinomycin resulted in increases of the fluorescence intensity for
MFG or MTG with only a few exceptions. The fluorescence intensity of cells
stained with 0.1 microM NAO increased following incubation with BDM, nigericin,
and decreased for FCCP, CCCP, DNP, gramicidin, and valinomycin. The results with
5 microM NAO were similar. CONCLUSIONS: MFG, MTG, and NAO appeared poor choices
for the membrane potential independent analysis of mitochondrial membrane mass.
Considering the molecular structure of these probes that favor accumulation in
the mitochondrial membrane because of a positive charge, our results are not
surprising. Cytometry 39:203-210, 2000. Published 2000 Wiley-Liss, Inc.
PMID- 10685079
TI - A novel deep red/low infrared fluorescent flow cytometric probe, DRAQ5NO, for the
discrimination of intact nucleated cells in apoptotic cell populations.
AB - BACKGROUND: The linking of intracellular metabolism of anticancer drugs with
cellular response is problematic. We describe a new probe for cellular integrity,
based upon a structure which has the additional potential to act as a substrate
for cytochrome P450-dependent bioreductive metabolism. DRAQ5NO is an N-oxide
modified anthraquinone with optimal fluorescence excitation maxima compatible
with He-Ne (633 nm) and Kr-Ar (647 nm) lasers. METHODS: DRAQ5NO-loading and
Annexin V binding was monitored using dual-laser flow cytometry (488 nm/633 nm
wavelengths) in human lymphoma cultures undergoing anticancer drug- (etoposide;
VP-16) induced apoptosis. RESULTS: DRAQ5NO gave an Em(lambdamax) of 700.5 nm but
retains DNA binding potential with an emission wavelength red-shift of
approximately 12 nm. The agent showed reduced cytotoxicity and a limited capacity
to accumulate within cells compared with the non-N-oxide form that shows a high
nuclear targeting capacity in intact cells. DRAQ5NO/Annexin V provides for a
positive discrimination between intact cells, membrane-compromised cells,
cellular debris, and early stage apoptotic cells. CONCLUSIONS: The spectral
properties of DRAQ5NO allow for the use of visible range fluorochromes and
differential excitation in multilaser systems for tracking apoptotic populations
with implications for the measurement of bioreductive potential in complex tumour
populations simultaneously undergoing physiologically or drug-induced apoptosis.
PMID- 10685081
TI - Purification of human tonsil plasma cells: pre-enrichment step by immunomagnetic
selection of CD31(+) cells.
AB - BACKGROUND: The advancement of knowledge about the biology of human normal plasma
cells (PC) is hampered by their low frequency and difficult isolation. The aim of
this study is to design a way of purifying these cells. METHODS: To this end,
advantage was taken of the fact that human tonsil PC expressed surface CD31 at
higher levels than the rest of tonsil B cells. RESULTS: The immunomagnetic
selection of CD31(+) cells from tonsil B cells increased by a factor of 12 the
proportion of PC, determined as CD38(high) cells. This method recovered half of
the initial number of PC, and did not alter the PC functions, because IgG
secretion was similar in control B cell cultures as well as in cultures of B
cells obtained at successive steps of the selection procedure. In addition,
CD38(high) cells pre-enriched by this technique were readily isolated by FACS
sorting and clearly identified as PC. CONCLUSIONS: Therefore, immunomagnetic pre
enrichment of CD31(+) cells is an efficient method that allows the complete
purification of human functional PC.
PMID- 10685080
TI - Fetal nucleated erythrocyte recovery: fluorescence activated cell sorting-based
positive selection using anti-gamma globin versus magnetic activated cell sorting
using anti-CD45 depletion and anti-gamma globin positive selection.
AB - BACKGROUND: Fluorescence activated cell sorting (FACS)-based anti-gamma (gamma)
positive selection and magnetic activated cell sorting (MACS)-based anti-CD45
depletion followed by anti-gamma positive staining have been two of the most
frequently used methods to isolate fetal cells from maternal blood. To date,
there has been no direct comparison of fetal cell recovery by these two methods.
This study was designed to address this issue. METHODS: Fluorescence in situ
hybridization (FISH) was performed on nucleated anti-gamma positive cells using X
and Y probes. Twenty-four maternal blood samples were obtained immediately after
elective termination of pregnancy to ensure a detectable number of fetal cells.
RESULTS: The yield and purity of fetal nucleated erythrocytes (FNRBCs) was
statistically higher in FACS sorted samples (P < 0.01). The specificity of
staining for FNRBCs was statistically higher in MACS sorted samples (P < 0.01).
CONCLUSIONS: The data from this study demonstrate that both techniques have
benefits and limitations. FACS has the advantage of having higher yield, higher
purity, higher FISH efficiency and ease in microscope analysis, and MACS has the
advantage of having higher specificity and less cell loss during FISH.
PMID- 10685082
TI - Accurate quantitation of Leishmania infection in cultured cells by flow
cytometry.
AB - BACKGROUND: Leishmaniases are major parasitic diseases caused by protozoans that
are obligate intracellular parasites during the mammalian phase of their life
cycle. Quantitation of experimental mammalian cell infections is usually
performed by time-consuming microscopic examination. In this report a flow
cytometry (FCM)-based assay suitable for studying in vitro infections by
L.amazonensis is presented. METHODS: Intense fluorescence staining of the
amastigote forms with a stage- and species-specific monoclonal antibody was
obtained after permeabilization of both the host-cell cytoplasmic membrane and
the parasitophorous vacuole membrane by saponin treatment. RESULTS: Upon flow
cytometry (FCM) analysis, parasitized cells separated sharply from the auto
fluorescence of the mammalian host cells, giving the assay a high degree of
sensitivity and specificity. Ninety to 98% of cells in the more fluorescent
population harbored parasites visible by phase-contrast and UV-light microscopy,
while no parasites were observed in more than 95% of the cells in the population
with background fluorescence. Comparisons of the FCM results with those from
microscope counting and analysis of various dilutions of parasitized cells
confirmed the reliability of the method. CONCLUSIONS: The FCM assay provided
rapid quantitation of Leishmania infection either in mouse macrophages, the
natural host cell in murine leishmaniasis, or in Chinese hamster ovary (CHO)
cells, a non-macrophage cell line proposed as an in vitro model for studying host
parasite interactions. The protocol described here should be adaptable to studies
involving other parasites residing in nucleated cells.
PMID- 10685083
TI - In this issue. Dermatologic laser surgery.
PMID- 10685084
TI - Recent developments in cutaneous lasers.
PMID- 10685085
TI - Imaging superficial tissues with polarized light.
AB - OBJECTIVE: Polarized light can be used to obtain images of superficial tissue
layers such as skin, and some example images are presented. This study presents a
study of the transition of linearly polarized light into randomly polarized light
during light propagation through tissues. STUDY DESIGN/MATERIALS AND METHODS: The
transition of polarization was studied in polystyrene microsphere solutions, in
chicken muscle (breast) and liver, and in porcine muscle and skin. The transition
is discussed in terms of a diffusion process characterized by an angular
diffusivity (radians(2)/mean free path) for the change in angular orientation of
linearly polarized light per unit optical path traveled by the light. RESULTS:
Microsphere diffusivity increased from 0.031 to 0.800 for diameters decreasing
from 6.04 microm to 0.306 microm, respectively. Tissue diffusivity varied from a
very low value (0.0004) for chicken liver to an intermediate value (0.055) for
chicken and porcine muscle to a very high value (0.78) for pig skin. CONCLUSION:
The results are consistent with the hypothesis that birefringent tissues
randomize linearly polarized light more rapidly than nonbirefringent tissues. The
results suggest that polarized light imaging of skin yields images based only on
photons backscattered from the superficial epidermal and initial papillary dermis
because the birefringent dermal collagen rapidly randomizes polarized light. This
anatomic region of the skin is where cancer commonly arises.
PMID- 10685086
TI - Evaluation of cooling methods for laser dermatology.
AB - BACKGROUND AND OBJECTIVE: Skin cooling is used to protect the epidermis in a
variety of laser dermatology procedures, including leg vein treatment, hair
removal, and port wine stain removal. Spray and contact cooling are the two most
popular methods, but similarities and differences of these techniques are not
well understood. STUDY DESIGN/MATERIALS AND METHODS: A theoretical model of skin
cooling is presented for two different regimens: "soft" cooling in which freezing
of the skin is not permitted and "hard" cooling in which the skin can be frozen
to a given depth. Spray and contact cooling were also compared experimentally
using an in vitro model. RESULTS: For a fixed skin surface temperature, spray and
contact cooling theoretically produce the same cooling profile in the skin.
Anatomic depth of cooling depends on the time for which either the spray or
contact is applied. In vitro experiments caused temperature at the simulated
basal layer to be between -5 and +5 degrees C for both spray (tetrafluoroethane,
boiling point -26 degrees C) and contact (-27 degrees C sapphire plate) cooling.
The theoretical precooling analysis shows hard mode to be faster and more
selective than soft mode; however, cooling time for hard mode must be carefully
controlled to prevent irreversible epidermal damage caused by freezing.
CONCLUSIONS: Both spray and contact cooling provide efficient skin cooling. The
choice of cooling method depends on other factors such as the target depth, cost,
safety, and ergonomic factors.
PMID- 10685087
TI - Bioheat transfer analysis of cryogen spray cooling during laser treatment of port
wine stains.
AB - BACKGROUND AND OBJECTIVE: The thermal response of port wine stain (PWS) skin to a
combined treatment of pulsed laser irradiation and cryogen spray cooling (CSC)
was analyzed through a series of simulations performed with a novel optical
thermal model that incorporates realistic tissue morphology. STUDY
DESIGN/MATERIALS AND METHODS: The model consisted of (1) a three-dimensional
reconstruction of a PWS biopsy, (2) a Monte Carlo optical model, (3) a finite
difference heat transfer model, and (4) an Arrhenius thermal damage calculation.
Simulations were performed for laser pulses of 0.5, 2, and 10 ms and a wavelength
of 585 nm. Simulated cryogen precooling spurts had durations of 0, 20, or 60 ms
and terminated at laser onset. Continuous spray cooling, which commenced 60 ms
before laser onset and continued through the heating and relaxation phases, was
also investigated. RESULTS: The predicted response to CSC included maximal pre
irradiation temperature reductions of 27 degrees C at the superficial surface and
12 degrees C at the dermoepidermal junction. For shorter laser pulses (0.5, 2
ms), precooling significantly reduced temperatures in superficial regions, yet
did not effect superficial vessel coagulation. Continuous cooling was required to
reduce significantly thermal effects for the 10-ms laser pulse. CONCLUSIONS: For
the PWS morphology and treatment parameters studied, optimal damage distributions
were obtained for a 2-ms laser pulse with a 60-ms precooling spurt. Epidermal and
vascular morphology as well as laser pulse duration should be taken into account
when planning CSC/laser treatment of PWS. Our novel, realistic-morphology
modeling technique has significant potential as a tool for optimizing PWS
treatment parameters.
PMID- 10685088
TI - New approaches to the treatment of vascular lesions.
AB - BACKGROUND AND OBJECTIVE: The pulsed dye laser was developed based on the concept
of selective photothermolysis. By using a wavelength of light well absorbed by
the target and pulse duration short enough to spatially confine thermal injury,
specific vascular injury could be produced. STUDY DESIGN/MATERIALS AND METHODS:
Although the pulsed dye laser revolutionized the treatment of port wine stains
(PWS) and a variety of other vascular lesions, the ideal thermal relaxation time
for the vessels in PWS is actually 1-10 ms, not 450 micros of the original pulsed
dye laser machines. These original theoretical calculations recently have been
proven correct in a study that used both an animal vessel model and in human PWS.
RESULTS: Longer wavelengths of light, within the visible spectrum, penetrate more
deeply into the skin and are more suitable for deeper vessels, whereas longer
pulse durations are required for larger caliber vessels. CONCLUSION: A variety of
lasers recently have been developed for the treatment of vascular lesions which
incorporate these concepts into their design, including pulsed dye lasers at 1.5
ms, a filtered flash-lamp pulsed light source with pulse durations of 1-20 ms,
several 532-nm pulsed lasers with pulse durations of 1 ms to as high as 100 ms,
long pulsed alexandrite lasers at 755 nm with pulse durations up to 20 ms, pulsed
diode lasers in the 800 to 900 nm range, and long pulsed 1064 Nd:YAG sources.
PMID- 10685089
TI - Mathematical modeling for the prediction and optimization of laser hair removal.
AB - BACKGROUND AND OBJECTIVE: The study of hair removal is a slow, tedious process.
Efficacy evaluations require test-site observation for at least one complete hair
cycle, a minimum of 6-8 months. In addition, tracking and counting individual
hairs is extremely labor intensive. The objective of this study was to develop
and evaluate a mathematical model for hair removal that could significantly speed
the entire process. STUDY DESIGN/MATERIALS AND METHODS: Generally accepted
kinetic and statistical modeling methods were used to develop a mathematical
description of hair growth. The anagen and telogen percentages and decay times
were the variables used to predict the kinetics of untreated hair. In the case
that the follicles were treated, it was necessary to additionally consider the
possible outcomes after treatment, making the calculations much too complicated
for simple mathematical formulations. Therefore, a computerized statistical model
was developed that considered the probabilities of no, partial, or complete
follicular damage in addition to the untreated model variables. These models were
then evaluated by comparing them to data derived from the literature and a study
center. RESULTS: Values derived from the mathematical model were capable of
closely approximating the experimental results of untreated (shaving) and treated
(plucking, electrolysis, ruby laser, Q-switched Nd:YAG laser) hair growth
kinetics. The model was also shown to be useful for optimizing the number and
interval of Q-switched Nd:YAG laser treatments. CONCLUSIONS: A mathematical model
can be used to reliably predict results from a variety of hair removal
techniques. It also appears to be useful for optimizing a particular treatment
protocol. In addition, the development of new hair removal products may be aided
by using this method.
PMID- 10685090
TI - Ruby laser hair removal: evaluation of long-term efficacy and side effects.
AB - BACKGROUND AND OBJECTIVE: Although several studies on laser-assisted hair removal
have been published, data on long-term follow-up are few. The present study
investigated the long-term efficacy and safety of normal-mode ruby laser pulses
on hair removal. STUDY DESIGN/MATERIALS AND METHODS: The normal-mode ruby laser
(Epilaser; 694 nm, 3 msec) was used to treat a wide range of body sites in 51
volunteers. The mean follow-up after the last treatment was 8.37 months. RESULTS:
Sixty-three percent of the patients had sparse regrowth. The mean fluence used
was 46.5 J/cm(2) in patients who had sparse hair regrowth and 39.3 J/cm(2) in
patients who had moderate hair regrowth (P = 0.0127). Transient pigmentary
changes occurred most frequently in patients with skin type 4. CONCLUSION: The
normal-mode ruby laser is an efficient and safe method for long-term hair
reduction, especially in fair-skinned individuals with dark hair. Higher fluences
produce greater long-term efficacy. Adverse effects are minimal and transient.
PMID- 10685091
TI - Nonablative skin remodeling: selective dermal heating with a mid-infrared laser
and contact cooling combination.
AB - BACKGROUND AND OBJECTIVE: Many of the microscopic changes associated with
photodamage reside in the dermis. It follows that subsurface heating of the skin
might allow for cosmetic enhancement without loss of the epidermis. Accordingly,
we investigated the clinical and microscopic changes produced by a mid-infrared
laser coupled with a contact cooling device. STUDY DESIGN/MATERIALS AND METHODS:
Nine patients were treated with an erbium glass laser and sapphire cooling
handpiece in contact with the skin. Postauricular sites were irradiated with
pulse energies varying from 400-1,200 mJ and numbers of pulses from 4 to 40.
Outcome measures included pain, edema, and erythema at predetermined
postoperative intervals. Biopsies were performed just after treatment and 2
months postoperatively for selected pulse energy-pulse number combinations.
RESULTS: Erythema, edema, and pain increased with pulse energy and number of
pulses. Likewise, immediate epidermal necrosis and subsequent scarring were
observed for larger pulse energy-pulse number combinations. At sites with
epidermal preservation, on biopsy, immediate dermal thermal damage was observed
in a band-like pattern. The deep boundaries of this band were dependent on pulse
energy and pulse number. After 8 weeks, biopsies showed dermal fibroplasia
roughly correlating to the band of immediate dermal thermal damage. CONCLUSION:
Selective dermal heating can be achieved with a mid-infrared laser coupled to a
contact surface cooling device. In this study, the range of fibroplasia and lack
of clinically substantial cosmetic enhancement suggest that the dermal thermal
damage achieved may be too deep and that the injury should be confined to more
superficial levels to alter the most severely photodamaged dermis. Lasers Surg.
Med. 26:186-195, 2000. Published 2000 Wiley-Liss, Inc.
PMID- 10685092
TI - Nonablative treatment of rhytids with intense pulsed light.
AB - BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the efficacy and
complication rate of a nonablative nonlaser light source in the treatment of
rhytids. Laser resurfacing, in the treatment of facial rhytids, has involved
ablative methods, with their associated complications and limitations. Rhytid
improvement requires dermal collagen remodeling. Interest has begun to focus on
the use of wavelengths that preserve the epidermis but deliver enough energy to
promote rhytid improvement. STUDY DESIGN/MATERIALS AND METHODS: Thirty subjects
with class I-II rhytids and Fitzpatrick skin types I-II were treated with up to
four treatments with an intense pulsed light source. Subjects were evaluated 6
months after the final treatment. RESULTS: Twenty-five subjects showed some
improvement in the quality of skin. No subjects were found to have total
resolution of rhytids. CONCLUSION: Nonlaser intense pulsed light may effectively
improve some facial rhytids. Such improvement can occur without epidermal
ablation.
PMID- 10685093
TI - Prophylactic fluconazole promotes reepithelialization in full-face carbon dioxide
laser skin resurfacing.
AB - BACKGROUND AND OBJECTIVE: Laser skin resurfacing is used to treat photodamaged
skin, rhytids, and acne scarring. Many patients are placed on antibiotics and
antivirals pre- and postoperatively. The purpose of this study was to determine
whether prophylactic fluconazole increased the rate of reepithelialization in
patients undergoing full-face CO(2) laser skin resurfacing. STUDY
DESIGN/MATERIALS AND METHODS: Ninety-one patients underwent full-face CO(2) laser
skin resurfacing with the Coherent Ultrapulse 5000C. At least two passes of 300
mJ, density 5, were used except periocularly. Study group I consisted of 48
consecutive patients who received either cephalexin or ciprofloxacin for 7 days
postoperatively. Study group II consisted of 43 patients who received 300 mg of
fluconazole on postoperative days 3-8, in addition to ciprofloxacin. Both groups
received acyclovir 400 mg t.i.d. pre- and postoperatively. RESULTS: Time to
complete reepithelialization was compared between the groups by t-test. Group II
reepithelialized significantly faster than group I (7.65 +/- 1.20 days vs. 10.27
+/- 2.94 days; P < 0.0001). Ninety-five percent of patients receiving fluconazole
(group II) healed completely by day 9 versus only 53% of patients in group I.
CONCLUSION: Fluconazole administered postoperatively between days 3 and 8
significantly promotes reepithelialization in patients undergoing full-face CO(2)
laser skin resurfacing.
PMID- 10685094
TI - Variable pulse erbium:YAG laser skin resurfacing of perioral rhytides and side-by
side comparison with carbon dioxide laser.
AB - BACKGROUND AND OBJECTIVE: Laser resurfacing of facial rhytides has become a
popular treatment option for many patients with wrinkles, photoaging, and acne
scarring. Laser wavelength/pulse duration options and new techniques continue to
shorten the healing phase associated with laser skin resurfacing while
maintaining clinical efficacy. Variable pulse erbium:YAG (Er:YAG) laser systems
are now available that offer the surgeon the ability to vary the Er:YAG pulse
duration from a pulse that is primarily ablative to one that is more thermal. The
objective of this study was to evaluate the histologic effects created with a
variable pulse Er:YAG laser. To study prospectively the clinical effects on upper
lip rhytides with a variable pulse Er:YAG laser when compared side by side with
pulsed carbon dioxide (CO(2)) laser resurfacing. STUDY DESIGN/MATERIALS AND
METHODS: Forty-two treatment sites on 21 patients were randomized and evaluated
after treatment of the upper lip region with CO(2) laser resurfacing on one side
and a variable pulse Er:YAG laser on the other. Patient diaries were maintained
to assess erythema, crusting, pain, and pigmentary changes. Blinded objective
grading of improvement was performed. Chromometer measurements were obtained to
analyze erythema. RESULTS: The variable pulse Er:YAG laser treatment reduced the
duration of crusting on average from 7.7 days with CO(2) to 3.4 days. Chromometer
measurements noted decreased postoperative erythema. Grading by physicians in a
blinded manner showed 63% improvement for the CO(2) treatment site and 48%
improvement in the variable pulse Er:YAG site. No cases of permanent
hyperpigmentation, hypopigmentation, or scarring occurred. CONCLUSION: The
variable pulse Er:YAG laser resurfacing is a safe and effective resurfacing tool,
which combines ablative and thermal modalities. The protocol used in this study
approaches but does not equal the results we have traditionally seen with CO(2)
laser resurfacing.
PMID- 10685095
TI - Deep coagulation of dermal collagen with repetitive Er:YAG laser irradiation.
AB - BACKGROUND AND OBJECTIVE: Er:YAG lasers are known to effectively ablate human
skin with minimal thermal damage to subjacent dermal tissue. We have investigated
whether deep coagulation of dermal collagen, similar to that observed with the
CO(2) laser, could be achieved with repetitive Er:YAG laser exposures. STUDY
DESIGN/MATERIALS AND METHODS: Skin on the back of a Sprague-Dawley rat in vivo
was irradiated with sequences of 1-10 Er:YAG laser pulses at a repetition rate of
10 or 33 Hz and single-pulse fluences from 0.8 to 1.4 J/cm(2). The resulting
lesions were biopsied within 1 hour after laser exposure, and the histologic
sections were examined by using optical microscopy. RESULTS: The depth of dermal
collagen denaturation increases dramatically when 3-10 low-fluence Er:YAG laser
pulses are stacked at a repetition rate of 10 or 33 Hz. CONCLUSION: Coagulation
of dermal collagen deeper than 200 microm below the epidermal-dermal junction is
feasible by using the appropriate settings of a repetitive Er:YAG laser.
PMID- 10685096
TI - Modulating the Er:YAG laser.
AB - BACKGROUND AND OBJECTIVES: In the past 2 years, there has been some controversy
about the optimal laser system, or combination of systems, for cutaneous
resurfacing. Initially, it seemed that the Er:YAG laser would have significant
advantages over the CO(2) laser. In practice, some of those who jumped early onto
the Er:YAG bandwagon have been unimpressed with the degree of skin tightening
that can be achieved with this system. Also, the excessive bleeding induced by
the Er:YAG lasers prevented deeper vaporization. During the past 18 months, three
new "modulated" Er:YAG lasers have been produced that are said to be able to
achieve CO(2) laser-like effects, while maintaining the Er:YAG laser advantages.
The purpose of this article is to examine these new systems and to discuss their
potential benefits, if any, over the "conventional" Er:YAG lasers, and the CO(2)
lasers. STUDY DESIGN/MATERIALS AND METHODS: The author has collected data from
his own experience and that of his colleagues in the department of dermatology at
University of California at San Francisco. The author has used all three types of
modulated Er:YAG laser on patients presenting for cosmetic laser resurfacing and
the treatment of many benign conditions over an 18-month period. RESULTS: All
three modulated forms of Er:YAG lasers have been demonstrated to provide better
coagulation than the conventional Er:YAG lasers. The Derma-K and the Contour
Er:YAG lasers were able to induce tissue contraction/desiccation similar to the
CO(2) laser. The author and his colleagues have induced only two cases of
permanent hypopigmentation in over 50 cases during the past 18 months while using
the Er:YAG laser, significantly less than might be expected with the CO(2)
lasers. CONCLUSIONS: If a laser surgeon is happy with the results obtained with a
high-energy, short-pulse CO(2) laser, then there seems little reason to consider
changing to an Er:YAG laser. The modulated Er:YAG lasers have definite advantages
over the conventional Er:YAG lasers. They exhibit better control of hemostasis
and can ablate tissue to a greater depth than the conventional Er:YAG lasers. The
Er:YAG lasers might induce less permanent hypopigmentation than the CO(2) lasers.
PMID- 10685097
TI - Fatty acid incorporation by Rhodnius prolixus midgut.
AB - [(14)C]Oleic acid injected into the hemocoel of Rhodnius prolixus females was
shown to rapidly associate with lipophorin particles. Half of the lipophorin
associated [(14)C]oleic acid was transferred in about 5 min to different organs,
but the midgut was the main organ to take it up on day 10 after a blood meal. The
rate of [(14)C]oleic acid incorporation by the midgut was high up to 15 min after
injection and then declined. The [(14)C]oleic acid incorporated by the midgut was
found in phospholipids (58.6%) and neutral lipids (37.4%). The midgut capacity to
incorporate [(14)C]oleic acid varied on different days after a meal: it increased
up to day 10 and then decreased. The fate of the [(14)C]lipids synthesized by the
midgut was followed and it was observed that 10 days after feeding diacylglycerol
was the main lipid released to hemolymph and that most of phospholipids and
triacylglycerols remained associated with the midgut. The metabolism of free
fatty acids in Rhodnius prolixus females is discussed in the context of major
biological events that follow a blood meal such as digestion and oogenesis.
PMID- 10685098
TI - Identification of cuticular hydrocarbons and the alkene precursor to the
pheromone in hemolymph of the female gypsy moth, Lymantria dispar.
AB - Hydrocarbons were extracted from the surface of the cuticle and from the
hemolymph of adult female gypsy moths. GC and GC/MS analysis indicated that the
cuticular hydrocarbons with chain lengths >21 carbons were the same as those
found in the hemolymph. These consisted of mostly saturated straight chain
hydrocarbons with heptacosane the major component. Methyl branched hydrocarbons
were also identified including a series of tetramethylalkanes with chain lengths
of 30, 32, and 34 carbons. In addition to those found on the cuticle surface, the
hemolymph contained the alkene pheromone precursor, 2-methyl-Z7-octadecene and
two saturated analogues, 2-methyl-octadecane and 2-methyl-hexadecane. No evidence
was obtained for the presence of the pheromone 2-methyl-7, 8-epoxy-octadecane in
the hemolymph. Pheromone gland extracts indicated that small amounts (<1 ng) of
the alkene precursor were also present in the gland. Relatively larger amounts of
the alkene precursor were found in the hemolymph at the time when pheromone
titers were higher on the gland. The presence of the hydrocarbon pheromone
precursor in the hemolymph is discussed in relation to possible biosynthetic
pathways for producing the gypsy moth pheromone.
PMID- 10685099
TI - Characterization of proteases from a stored product mite, Tyrophagus
putrescentiae.
AB - Extracts of Tyrophagus putrescentiae feces exhibited higher (>50-fold) specific
protease activity rates than those measured using mite body extracts for the
substrates azocasein, BApNa, SA(2)PPpNa, HA, and HPA. This suggests that trypsin,
chymotrypsin, and carboxypeptidases A and B are involved in mite digestion.
Hydrolysis of the substrates ZAA(2)MNA and LpNa was only 3 times higher in fecal
extracts, suggesting that levels of cathepsin B and aminopeptidases in the lumen
of the digestive tract are low compared to the other enzymes. The hydrolysis of
hemoglobin was only detected in body extracts indicating that cathepsin D is not
a digestive protease in this species. Protease inhibitors of different
specificity were tested invivo to establish their potential as control agents. We
found that development from larvae to adult was significantly retarded in larvae
fed on brewers' yeast containing inhibitors of serine proteases, whereas no such
effect was found with inhibitors of cysteine and aspartyl proteases.
Interestingly, when dietary mixtures of serine protease, aminopeptidase and
carboxypeptidase inhibitors were fed to T.putrescentiae, a synergistic effect was
observed that retarded development. Several plant lectins were also tested, but
none affected development.
PMID- 10685100
TI - Periodicity of sex pheromone biosynthesis, release and degradation in the
lightbrown apple moth, Epiphyas postvittana (Walker).
AB - Pheromone titer in moths is a product of three processes occurring in or at the
surface of the pheromone gland: biosynthesis, release, and intraglandular
degradation, of pheromone. Changes in titers of sex pheromone, the fatty acyl
pheromone analog (FAPA), and tetradecanoate, a pheromone biosynthetic
intermediate, were studied in detail in the lightbrown apple moth, Epiphyas
postvittana (Walker). Although changes in the pheromone titers in a day were
relatively small, with the peak titer being 2-3 times greater than that at the
trough, pheromone titer did show a distinct diel periodicity. Titer of the FAPA
showed a similar, but less variable, diel pattern, but tetradecanoate titer
showed little or no diel pattern. The pattern of pheromone titer suggested that
females biosynthesize pheromone at two different rates during the photoperiod: a
high rate during the latter half of the photophase and most of the scotophase,
which is associated with a high pheromone titer, and a low rate throughout the
first half of the photophase, which is associated with a low titer. Consistent
with data on commencement of copulation, pheromone was released from the second
hour of the scotophase through to the eighth hour. Pheromone release rate during
this period appeared to be similar to the rate of pheromone biosynthesis. In
contrast to the other two processes, pheromone degradation did not appear to have
a diel pattern. Females decapitated at different times of the photoperiod showed
a similar decline in pheromone titer, consistent with the reaction kinetics being
first order in pheromone titer.
PMID- 10685101
TI - Artificial reproduction in a hymenopteran insect, Athalia rosae, using eggs
matured with heterospecific yolk proteins and fertilized with cryopreserved
sperm.
AB - Previtellogenic ovaries of Athalia rosae (Hymenoptera, Symphyta, Tenthredinidae)
were transplanted into the adult female abdominal hemocoel of Athalia infumata
(Symphyta, Tenthredinidae), Arge nigrinodosa (Symphyta, Argidae), and Pimpla
nipponica (Apocrita, Ichneumonidae). The donor oocytes accumulated heterospecific
yolk proteins and matured in the A. infumata host. On average, six mature oocytes
were obtained per transplanted ovary. In contrast, the donor oocytes accumulated
a limited amount of yolk but did not mature in the Ar. nigrinodosa host and did
not even accumulate yolk in the P. nipponica host. The eggs that matured in the
A. infumata host were injected with cryopreserved A. rosae sperm that had been
taken from adult male seminal vesicles and stored at -80 degrees C.
Fertilization, as confirmed by the use of visible marker mutations, was achieved
and a fraction of the injected eggs developed into fertile female adults.
PMID- 10685102
TI - Pesticide residues in medicinal plants and phytomedicines.
AB - Pesticides, which are mainly applied on crops for the protection of plants
against a range of pests, have been found in crude medicinal plants as well as in
infusions, decoctions, tinctures and essential oils. This fact has caused concern
in various segments of society and scientific investigation has been demanded to
assess the health hazards more accurately. The present review covers more than 30
years (1963-1998) of published methods of analysing pesticide residues in
medicinal plants, with special emphasis on the relevance of these matrices, the
legislation, the risks involved in using material containing uncontrolled amounts
of residues and the possible effects of technological factors on the proportion
of pesticide transferred from the raw material to the end product.
PMID- 10685103
TI - Antiviral effect of flavonoids on the dengue virus.
AB - In the present study we analysed the possible antiviral effect on dengue viruses
of different flavonoids extracted and identified at the Chemistry Institute,
UNAM, from the Mexican plants Tephrosia madrensis, Tephrosia viridiflora and
Tephrosia crassifolia. The flavonoids glabranine and 7-O-methyl-glabranine
presented 70% inhibition on the dengue virus at a concentration of 25 microM,
while methyl-hildgardtol A, hildgardtol A and elongatine had no effect on viral
growth. Our results show that glabranine and 7-O-methyl-glabranine isolated from
Tephrosia s.p. exert a dose-dependent inhibitory effect in vitro on the dengue
virus.
PMID- 10685104
TI - Phenylpropanoids from Ballota nigra L. inhibit in vitro LDL peroxidation.
AB - From the European plant Ballota nigra L. various polyphenols including
phenylpropanoid derivatives were isolated. There is increasing evidence that
oxidized low-density lipoproteins (Ox-LDL) might be involved in the pathogenesis
of atherosclerosis and it has been reported that polyphenols inhibit LDL
peroxidation and atherogenesis. The goal of this study was to test whether the
major polyphenolic compounds extracted from Ballota nigra, four phenylpropanoid
glycosides, verbascoside, forsythoside B, arenarioside, and ballotetroside and
one non-glycosidic phenylpropanoid, caffeoyl-L-malic acid, inhibit Cu(2+)-induced
LDL peroxidation. The effectiveness of these compounds was compared to the
activity of quercetin, a well-known polyphenol inhibitor of Cu(2+)-induced LDL
oxidation. Antioxidant efficacious doses (ED 50) of arenarioside and
ballotetroside were 1.8 microM and 7.5 microM respectively, while in the same
conditions, the ED 50 of forsythoside B and verbascoside were similar (1 microM)
and those of quercetin and of caffeoyl-L-malic acid were 2.3 microM and 9.5
microM respectively. Spectrophotometric studies show that quercetin is a Cu(2+)
chelator while phenylpropanoid glycosides and caffeoyl-L-malic acid are not
Cu(2+) chelators. Therefore, phenylpropanoid glycosides are strong inhibitors of
Cu(2+)-induced LDL oxidation, independent of any capacity to act as Cu(2+)
chelators.
PMID- 10685105
TI - Toxicological evaluation of the hydro-alcohol extract of the dry leaves of Peumus
boldus and boldine in rats.
AB - The hydro-alcohol extract of the dry leaves of Peumus boldus and boldine, showed
abortive and teratogenic action and changes in the blood levels of bilirubin,
cholesterol, glucose, alanine aminotransferase (ALT), aspartate aminotransferase
(AST) and urea in rats. The long term administration of the extract and boldine
did not cause histological modification during a period of 90 days.
PMID- 10685106
TI - Hypoglycaemic action of the flavonoid fraction of Cuminum nigrum seeds.
AB - The seeds of Cuminum nigrum were screened phytochemically and were found to
contain 8% flavonoids and 0.01% alkaloids. When studied for their effect on blood
glucose levels, oral administration of the flavonoid contents of the plant caused
a hypoglycaemic effect at a dose range of 0.5 to 1.5 g/kg, both in normal and
alloxan-diabetic rabbits. The hypoglycaemic effect started 2 h after drug
administration, reaching a maximum within 4-8 h and the blood glucose levels
returned close to normal within 24 h of drug administration. The glibenclamide (5
mg/kg), produced a hypoglycaemic effect in the normal rabbits, whereas it had no
effect on the blood glucose levels of alloxan-diabetic rabbits. The alkaloids
isolated from C. nigrum seeds, however, failed to exert any significant
hypoglycaemic effect in either the normal or diabetic rabbits. A 7 day acute
toxicity study in rabbits did not produce any apparent adverse effect at doses as
high as 5 g/kg orally. These data indicate that the total flavonoid contents of
C. nigrum seeds exhibited considerable hypoglycaemic activity in rabbits and may
therefore be responsible for the previously reported antidiabetic activity of the
seeds. Furthermore, it is conceivable that the C. nigrum flavonoids possess
insulin triggering and/or insulin-like properties.
PMID- 10685107
TI - Effect of Psidium guajava leaves on some aspects of the central nervous system in
mice.
AB - The present work examines the effects of hexane, ethyl acetate and methanol
extracts of Psidium guajava leaves (20,100,500 and 1250 mg/kg) on the central
nervous system in mice. The three extracts exhibited mostly dose-dependent
antinociceptive effects in chemical and thermal tests of analgesia. The extracts
also produced dose-dependent prolongation of pentobarbitone-induced sleeping
time. However, they had variable and mostly non-significant effects on locomotor
coordination, locomotor activity or exploration. In the pharmacological tests
used, the ethyl acetate extract seemed to be the most active, followed by the
hexane and then the methanol extracts.
PMID- 10685108
TI - Antibacterial activity of diospyrin, isodiospyrin and bisisodiospyrin from the
root of Diospyros piscatoria (Gurke) (Ebenaceae).
AB - Two dimeric naphthoquinones, diospyrin and isodiospyrin, isolated from the root
of Diospyros piscatoria (Gurke), a common ingredient in several folk medicines,
have been shown to have a broad spectrum of antibacterial activity. The minimum
inhibitory concentrations (MICs) of diospyrin against Streptococcus pyogenes ATCC
12344 and Streptococcus pneumoniae ATCC 33400 ranged from 1.56 to 50 microg/mL.
While those against Salmonella choleraesuis serotype typhi (S. typhi), ATCC 6539
and Mycobacterium chelonae ATCC 19977 were between 25 and 100 microg/mL.
Isodiospyrin was more active than its racemic isomer diospyrin. The MICs against
Gram-positive bacteria ranged from 0.78 to 50 microg/mL. While those against
Pseudomonas aeruginosa ATCC 15443 and S. typhi ranged from 50 to 100 microg/mL.
The MIC for M. chelonae was between 6.25 and 25 microg/mL. MICs were found to
increase with the concentration of cells used for the inoculum. The MICs for
Bacillus subtilis ATCC 6633 increased up to the highest concentration of cells
tested. The same phenomenon was observed on M. chelonae, but with better effect
in the latter. The kinetics of bacteria studies against both B. subtilis and M.
chelonae increases with increasing concentration of isodiospyrin tested. Two
tetrameric forms of plumbagin were isolated. The naphthoquinone bisisodiospyrin,
gave MIC values between 300 and 400 micro g/mL. The second, as yet unidentified
tetramer, was not active at 500 micro g/mL.
PMID- 10685109
TI - Evaluation of antibacterial activity of Asparagus racemosus willd. root.
AB - Different concentrations (50, 100, 150 microg/mL) of the methanol extract of the
roots of Asparagus racemosus Willd. showed considerable in vitro antibacterial
efficacy against Escherichia coli, Shigella dysenteriae, Shigella sonnei,
Shigella flexneri, Vibrio cholerae, Salmonella typhi, Salmonella typhimurium,
Pseudomonas putida, Bacillus subtilis and Staphylococcus aureus. The effects
produced by the methanol extract were compared with chloramphenicol.
PMID- 10685111
TI - Adrenocorticosterone alterations in male, albino mice treated with Trichopus
zeylanicus, Withania somnifera and Panax ginseng preparations.
AB - The levels of corticosterone were estimated by the HPLC method in the adrenal
glands of stressed (5 h constant swimming) male albino mice treated with
Trichopus zeylanicus, Withania somnifera and Panax ginseng preparations and
compared with non-treated stressed and normal controls. The treatments increased
the corticosterone levels in all the groups. The physical endurance (increased
survival time) of swimming mice also increased in all the treated groups, except
in the group treated with Withania somnifera powder (500 mg/kg, p.o.).
PMID- 10685110
TI - Effect of Ocimum sanctum roots extract on swimming performance in mice.
AB - The effect of a methanol extract, obtained from the roots of Ocimum sanctum, on
mouse swimming performance were studied using three different doses. On the basis
of our findings, a high dose (400 mg/kg, i.p.) of the extracts of Ocimum sanctum
increased the swimming time suggesting a central nervous system stimulant and/or
antistress activity. The effect produced by the extract was comparable to that of
desipramine, an antidepressant drug.
PMID- 10685112
TI - Screening of Mediterranean Rosaceae plants for their molluscicidal and piscicidal
activities.
AB - Extracts of increasing polarity of 13 plants belonging to Mediterranean Rosaceae
were tested for possible lethal toxicity against Biomphalaria glabrata Say, a
snail intermediate host of Schistosoma mansoni Sambon. Due to the search for
compounds without toxicity in nontarget organisms, principally fish and humans,
the piscicidal toxicity of the active extracts was also evaluated.
PMID- 10685113
TI - Effects of the water soluble fraction from leaves of Ageratum conyzoides on
smooth muscle.
AB - The water soluble fraction of Ageratum conyzoides L. (WSF) was studied in
isolated rat uterus and intestinal smooth muscles in order to evaluate its
popular use as a spasmolytic. WSF (0.2 and 0.4 mg/mL) increased EC(50) values and
decreased maximum responses to acetylcholine and calcium chloride. WSF (0.5-3.3
mg/mL) also produced direct myorelaxant effect on smooth muscle preparations.
Theophylline (10(-3) M) potentiated the relaxant action of WSF. Theophylline also
prevented the decrease in maximum response promoted by WSF in acetylcholine
concentration-effect curves. These results seem to be partially linked to calcium
mobilization. The data also suggest that WSF could act synergistically with
theophylline in the inhibition of cyclic AMP phosphodiesterase. The results give
support to the popular medicinal indications of the plant.
PMID- 10685114
TI - Toxicological studies on stem bark, leaf and seed kernel of yellow oleander
(Thevetia peruviana).
AB - A comparative study of the toxic effects of extracts from stem bark, leaf and
seed kernel of yellow oleander (Thevetia peruviana) in albino rats was carried
out. Male and female albino rats weighing 150-200 g were administered crude
aqueous extracts of stem bark, leaf and seed kernel of the plant by
intraperitoneal injection or exposed to baits prepared with the dry extracts of
the plant parts. The control groups either received distilled water by injection,
or were fed non-poisoned baits. Extracts from all the plant parts were toxic, and
produced marked poisoning symptoms that culminated in death. Poisoning symptoms
manifested earlier (10 min after treatment) in rats administered aqueous kernel
extracts intraperitoneally as against 45 min to several hours in rats poisoned by
ingestion of toxicant. Poisoning symptoms indicated serious cardiac, neuromotor
and mental malfunctioning, and manifested as tachycardia, arrhythmia, paralysis,
ataxia and disorientation. The lethal dose was lowest (507 mg/kg) with the
concentrated aqueous kernel extract (CAKE), and highest (5700 mg/kg) with the
bait formulated using 40% of the kernel meal - FKM(B). Rats treated by injection
with aqueous kernel extract (AKE) died faster within 10 h, than those with the
aqueous leaf or stem bark extracts that died after 260 h. No mortality or
abnormal behavioural changes were observed among animals in the control groups.
PMID- 10685115
TI - Antihyperglycaemic activity of Musa sapientum flowers: effect on lipid
peroxidation in alloxan diabetic rats.
AB - Musa sapientum commonly known as 'banana' is widely used in Indian folk medicine
for the treatment of diabetes mellitus. Oral administration of 0.15, 0.20 and
0.25 g/kg body weight of the chloroform extract of the flowers for 30 days
resulted in a significant reduction in blood glucose and glycosylated haemoglobin
and an increase in total haemoglobin. The extract prevented a decrease in body
weight, and also resulted in a decrease in free radical formation in the tissues.
Thus the study shows that banana flower extract (BFEt) has an antihyperglycaemic
action. The decrease in thiobarbituric acid reactive substances (TBARS) and the
increase in reduced glutathione (GSH), glutathione peroxidase (GSH-Px),
superoxide dismutase (SOD) and catalase (CAT) clearly shows the antioxidant
property of BFEt. The effect of BFEt was more prominently seen in the case of
animals given 0.25 g/kg body weight. BFEt was more effective than glibenclamide.
PMID- 10685117
TI - Patents alert
PMID- 10685116
TI - The effect of reserpine, a modulator of multidrug efflux pumps, on the in vitro
activity of tetracycline against clinical isolates of methicillin resistant
Staphylococcus aureus (MRSA) possessing the tet(K) determinant.
AB - As part of a screening programme to identify modulators of multidrug efflux in
methicillin resistant Staphyloccocus aureus (MRSA), we have validated our assays
using the antihypertensive plant alkaloid reserpine. Clinical isolates of MRSA
were resistant to tetracycline and shown to possess the tet(K) determinant which
encodes for the Tet(K) efflux protein, which conferred high level resistance to
tetracycline (MIC = 128 microg/mL). In the presence of reserpine, a known
inhibitor of multidrug resistance (mdr) efflux pumps, this MIC was significantly
reduced (MIC = 32 microg/mL).
PMID- 10685118
TI - Selected bibliography
PMID- 10685119
TI - Evidence-based art of the clinical examination
PMID- 10685120
TI - Effect of hormone replacement therapy on the bone mass and urinary excretion of
pyridinium cross-links.
AB - CONTEXT: The menopause accelerates bone loss and is associated with an increased
bone turnover. Bone formation may be evaluated by several biochemical markers.
However, the establishment of an accurate marker for bone resorption has been
more difficult to achieve. OBJECTIVE: To study the effect of hormone replacement
therapy (HRT) on bone mass and on the markers of bone resorption: urinary
excretion of pyridinoline and deoxypyridinoline. DESIGN: Cohort correlational
study. SETTING: Academic referral center. SAMPLE: 53 post-menopausal women, aged
48-58 years. MAIN MEASUREMENTS: Urinary pyr and d-pyr were measured in fasting
urine samples by spectrofluorometry after high performance liquid chromatography
and corrected for creatinine excretion measured before treatment and after 1, 2,
4 and 12 months. Bone mineral density (BMD) was measured by dual energy X-ray
absorptiometry (DEXA) before treatment and after 12 months of HRT. RESULTS: The
BMD after HRT was about 4.7% (P < 0.0004); 2% (P < 0.002); and 3% (P < 0. 01)
higher than the basal values in lumbar spine, neck and trochanter respectively.
There were no significant correlations between pyridinium cross-links and age,
weight, menopause duration and BMD. The decrease in pyr and d-pyr was progressive
after HRT, reaching 28.9% (P < 0.0002), and 42% (P < 0.0002) respectively after 1
year. CONCLUSIONS: Urinary pyridinoline and deoxypyridinoline excretion decreases
early in hormone replacement therapy, reflecting a decrease in the bone
resorption rate, and no correlation was observed with the bone mass evaluated by
densitometry.
PMID- 10685121
TI - Prognostic factors in non-Hodgkin lymphomas.
AB - CONTEXT: In Hodgkin's disease, each clinical or pathologic stage can be related
to the extent of the area involved and predicts the next anatomical region at
risk for tumor dissemination. OBJECTIVE: To determine the best prognostic factors
that could predict survival in non-Hodgkin lymphoma cases. DESIGN: A
retrospective study. LOCATION: Department of Hematology and Transfusion Medicine,
Universidade Federal de Sao Paulo - Escola Paulista de Medicina. PARTICIPANTS:
142 patients with non-Hodgkin lymphoma diagnosed between February 1988 and March
1993. MAIN MEASUREMENTS: Histological subset, Sex, Age, Race, B symptoms,
Performance status, Stage, Extranodal disease, Bulk disease, Mediastinal disease,
CNS involvement, BM infiltration, Level of DHL, Immunophenotype. RESULTS: In the
first study (113 patients), the following variables had a worse influence on
survival: yellow race (P<0.1); ECOG II, III e IV (P<0.1) and extranodal disease
(P<0.1) for high grade lymphomas; constitutional symptoms (P<0.1), ECOG II, III e
IV (P<0.1) and involvement of CNS (P<0.1) for intermediate grade and the subtype
lymphoplasmocytoid (P=0.0186) for low grade lymphomas. In the second survey (93
patients), when treatment was included, the variables related to NHL survival
were: CNS involvement (P<0.1) for high grade lymphomas, constitutional symptoms
(P<0.1), ECOG II, III, IV (P=0.0185) and also CNS involvement (P<0.1) for the
intermediate group. There were no variables related to the survival for low-grade
lymphomas. CONCLUSIONS: The intermediate grade lymphomas were more compatible
with data found in the literature, probably because of the larger number of
patients. In this specific case, the treatment did not have an influence on the
survival.
PMID- 10685122
TI - Bilateral carotid body paraganglioma: case report.
AB - CONTEXT: Surgical treatment of carotid body paragangliomas is a challenge to the
surgeon because of the large vascularization of the tumor, involvement of the
carotid vessels and the close anatomical relationship with the cranial nerves.
CASE REPORT: A 63-year-old patient was submitted to resection of two carotid body
paraganglioma tumors found in the right-side and left-side carotid bodies at the
bifurcation of the common carotid arteries. Two surgeries were performed at
different times and neither of them presented any morbidity. Arteriography was
fundamental for diagnosis of the small, asymptomatic tumor on the right side.
DESIGN: Case Report
PMID- 10685123
TI - Cystic struma ovarii: a rare presentation of an infrequent tumor.
AB - CONTEXT: Struma ovarii, a rare neoplasm, is a monophyletic teratoma composed of
thyroid tissue. It is generally considered to account for less than 5% of mature
teratomas. CASE REPORT: A diagnosis of struma ovarii may be the source of many
diagnostic problems. It may be cystic and microscopic examination may only reveal
a few typical thyroid follicles, resulting in confusion with other cystic ovarian
tumors. Extensive sampling should be undertaken and immunohistochemistry may be
decisive in establishing the thyroid nature of the epithelial lining. The authors
report two cases of cystic struma ovarii, and discuss diagnostic criteria and the
limitations of frozen biopsies in these tumors.
PMID- 10685124
TI - The gut at war: the consequences of enteropathogenic Escherichia coli infection
as a factor of diarrhea and malnutrition.
AB - Diarrheal disease is still the most prevalent and important public health problem
in developing countries, despite advances in knowledge, understanding, and
management that have occurred over recent years. Diarrhea is the leading cause of
death in children under 5 years of age. The impact of diarrheal diseases is more
severe in the earliest periods of life, when taking into account both the numbers
of episodes per year and hospital admission rates. This narrative review focuses
on one of the major driving forces that attack the host, namely the
enteropathogenic Escherichia coli (EPEC) and the consequences that generate
malnutrition in an early phase of life. EPEC serotypes form dense microcolonies
on the surface of tissue-culture cells in a pattern known as localized adherence
(LA). When EPEC strains adhere to epithelial cells in vitro or in vivo they cause
characteristic changes known as Attaching and Effacement (A/E) lesions. Surface
abnormalities of the small intestinal mucosa shown by scanning electron
microscopy in infants with persistent diarrhea, although non-specific, are
intense enough to justify the severity of the clinical aspects displayed in a
very young phase in life. Decrease in number and height of microvilli, blunting
of borders of enterocytes, loss of the glycocalyx, shortening of villi and
presence of a mucus pseudomembrane coating the mucosal surface were the
abnormalities observed in the majority of patients. These ultrastructural
derangements may be due to an association of the enteric enteropathogenic agent
that triggers the diarrheic process and the onset of food intolerance responsible
for perpetuation of diarrhea. An aggressive therapeutic approach based on
appropriate nutritional support, especially the utilization of human milk and/or
lactose-free protein hydrolyzate-based formulas and the adequate correction of
the fecal losses, is required to allow complete recovery from the damage caused
by this devastating enteropathogenic agent.
PMID- 10685125
TI - Modification of high blood pressure after myocardial infarction.
AB - The treatment of high blood pressure (BP) after myocardial infarction is
extremely important to decrease reinfarction and mortality. BP should be
controlled more strictly in this high-risk hypertensive population. Recently,
many clinical trials have demonstrated the benefits of lifestyle modification and
antihypertensive agents, particularly beta-blockers and angiotensin-converting
enzyme inhibitors for the treatment of acute myocardial infarction. Treatment
with these agents that modify BP may benefit even normotensive patients after a
myocardial infarction, although the benefit is greater in hypertensives.
PMID- 10685126
TI - Management of hypercholesterolemia.
AB - Benefit from the treatment of hyperlipidemia has now been conclusively
documented, and this article has focused on the clinical trial data supporting
diet and drug therapy in adult patients with different lipoprotein disorders and
discussed therapeutic approaches with a focus on reducing plasma concentrations
of LDL cholesterol. National guidelines for the use of hypolipidemic drugs are
strongly supported by the clinical trials and have appropriately set lower target
concentrations of LDL cholesterol for patients with established atherosclerosis
or diabetic patients as compared with patients with more than two cardiovascular
risk factors or, the lowest risk group, patients without evidence of
atherosclerosis and fewer than two known cardiovascular risk factors. The goals
of therapy in patients with established atherosclerosis are to prevent further
progression and potentially induce regression, whereas in high-risk patients
(e.g., those with heterozygous familial hypercholesterolemia) without evidence of
atherosclerosis, the aims of therapy are to reduce LDL cholesterol to a
concentration at which subclinical atherosclerosis and xanthomas regress and the
patient does not develop premature cardiovascular disease. Evidence-based
medicine strongly supports clinical benefit from the treatment of
hypercholesterolemia in men and women with and without known coronary artery
disease, and the main goal should be ensure that patients who could benefit from
lipid-lowering therapy are effectively treated and followed to ensure long-term
compliance, efficacy, and safety.
PMID- 10685127
TI - Management of selected lipid abnormalities. Hypertriglyceridemia, low HDL
cholesterol, lipoprotein(a), in thyroid and renal diseases, and post
transplantation.
AB - Although the focus in treating lipid disorders is on reducing LDL cholesterol
levels, triglycerides, HDL cholesterol, and Lp(a) are all independent risk
factors that can be used clinically to assess cardiovascular risk. Decisions to
initiate drug therapy for LDL cholesterol reduction may be influenced by levels
of these other lipoprotein fractions. Data supporting intervention to modify
these factors is less abundant than for LDL cholesterol reduction, but in certain
circumstances drug therapy targeted at triglycerides or HDL cholesterol may be
appropriate. Patients with nephrotic syndrome and end-stage renal disease are at
particularly high risk for the development of cardiovascular disease and should
be treated aggressively for lipid disorders. Finally, solid organ transplant
recipients are almost always hyperlipidemic, and appropriate therapy could reduce
cardiovascular events.
PMID- 10685128
TI - Methods to enhance smoking cessation after myocardial infarction.
AB - The evidence linking smoking and coronary artery disease is quite strong, and
there is also a positive relationship between smoking cessation and reduction in
cardiovascular disease risk. Nicotine replacement therapy and bupropion are
effective treatments for smoking cessation and are most effective when combined
with behavioral counseling. Intensive multicomponent interventions that include a
case-management component have produced the highest smoking cessation rates for
patients who suffer a myocardial infarction.
PMID- 10685129
TI - Cardiovascular disease in diabetic patients.
AB - Cardiovascular disease is the most frequent cause of morbidity and mortality in
patients with diabetes. This article evaluates the results of clinical
interventions that have been tested for their ability to ameliorate
cardiovascular disease through identification and management of cardiovascular
risk factors. These include hyperglycemia, insulin resistance, dyslipidemia,
hypertension, cigarette smoking, and a procoagulant state. Attention to all
cardiovascular risk factors is necessary if physicians are to reduce the burden
of these complications in diabetic patients.
PMID- 10685130
TI - Effects of dietary modification and treatment of obesity. Emphasis on improving
vascular outcomes.
AB - This article has considered a vast literature attesting to the efficacy of
dietary intervention on risk factors and on vascular outcomes. Rather than rely
solely on pharmacotherapy to improve risk factors and vascular outcomes,
physicians, nurses, dietitians, pharmacists, and medical providers should
emphasize the benefits of a well-balanced, nutritionally sound dietary program.
It should be low in SFA; controlled in calories to avoid (or reduce) obesity; and
rich in fruits, vegetables, whole-grain products, and good sources of protein.
Emphasis on foods rich in n-3 fatty acids shows promise for reducing
cardiovascular outcomes. Further studies using these and antioxidants are eagerly
awaited.
PMID- 10685131
TI - Chronic infection and coronary artery disease.
AB - On a variety of fronts, chronic infection has been found to be significantly
associated with the development of atherosclerosis and the clinical complications
of unstable angina, myocardial infarction, and stroke. For the most part, these
are still just associations. Specific causative relationships on par with that
determined between H. pylori and peptic ulcer disease have not yet been
established. Potential mechanisms whereby chronic infections may play a role in
atherogenesis are myriad. In the case of C. pneumoniae, the effect may result
from direct vessel wall colonization, which may damage the vessel directly or
indirectly by initiating immunologic responses. In other cases, the effect may
simply be that of enhancing the preexisting chronic inflammatory response of the
body to standard risk factors, such as hyperlipidemia. Even though the infectious
agent may not directly infect the vessel wall, it may perform its critical role
from afar. Chronic infection might also influence preexisting plaque by enhancing
T cell activation or other inflammatory responses that may participate in the
destabilization of the intimal cap. Chronic infection may play a role in the
initiation, progression, or destabilization of atherosclerotic plaques. The
infectious agents with the most evidence to support a causative role in
atherosclerosis include C. pneumoniae and cytomegalovirus. Evidence is mounting
for a variety of other potential agents, including H. pylori, various periodontal
agents, and even hepatitis A. Future studies are expected to elucidate further
the pathophysiologic relationship between chronic infection and atherosclerosis
and to evaluate the potential of a variety of treatment approaches, including
antibiotics.
PMID- 10685132
TI - C-reactive protein, inflammation, and coronary risk.
AB - Data have revealed interactions between baseline concentration of hs-CRP and the
efficacy of common pharmacologic therapies in primary and secondary prevention,
suggesting not only that it may be possible to modify the increased risk
associated with elevated hs-CRP, but also that inflammatory markers may be useful
in targeting preventive therapies. Inflammatory markers may become a valuable
component of routine cardiovascular risk assessment.
PMID- 10685133
TI - Antiplatelet and anticoagulant therapy in the secondary prevention of ischemic
heart disease.
AB - Antiplatelet and anticoagulant medications play a major role in the secondary
prevention of ischemic heart disease. Numerous trials have demonstrated their
clinical benefits. Newer agents, such as clopidogrel, have challenged aspirin's
role as the premier medication for secondary prevention. Much remains to be
learned, however, about the merits of these different drug classes, relative to
one another and in combination.
PMID- 10685134
TI - Hormone replacement therapy and coronary heart disease. A new debate.
AB - Hormone replacement therapy is extensively used in the United States, especially
for the possible prevention of heart disease, osteoporotic fractures, and, more
recently, dementia. The results of recent clinical trials have raised new
questions about the risk and benefits of estrogen or estrogen/progesterone
therapy to prevent heart attacks, the choice of specific drug therapy such as
specialized estrogen receptor modulation (SERM). The change in risk factors,
especially weight gain or obesity, may determine the risks and benefits of
hormone replacement therapy.
PMID- 10685135
TI - Prospects for genetic therapy of cardiovascular disease.
AB - Significant progress has been made in cardiovascular gene therapy. Further
investigations are required to understand the basic science of vectors,
mechanisms of gene delivery, vector-associated immunogenicity, and
pathophysiology of vascular and myocardial diseases. In addition, catheter and
stent devices will be required to deliver vectors to the vasculature and
myocardium (Fig. 3). Despite these scientific challenges, molecular therapies for
cardiovascular diseases are being implemented into clinical practice.
PMID- 10685136
TI - Homocysteine, B vitamins, and coronary artery disease.
AB - This article discusses the metabolism of homocysteine, factors affecting its
plasma level, and the evidence for its role in the pathogenesis of vascular
disease. The treatment of hyperhomocysteinemia and its possible impact on
vascular disease prevention and progression are described also.
PMID- 10685137
TI - Antioxidants for vascular disease.
AB - The epidemiologic data do not support a strong role for vitamin C in reducing
risk of coronary disease. The evidence supporting a protective effect for the
family of dietary carotenoids is stronger, but any important protective effect
attributable to the specific supplementation of beta-carotene can be excluded.
Conversely, results from observational and experimental studies consistently
support an effect of vitamin E supplementation on reducing risk of coronary heart
disease. The evidence suggests that the major effect, if any, is found at
supplemental intake levels at or greater than 100 IU/d. If confirmed in further
trials, the net benefit of vitamin E supplementation among populations with
existing coronary disease may be substantial, although the current available
evidence is insufficient to warrant a change in public policy recommendations.
PMID- 10685138
TI - Effects of exercise and cardiac rehabilitation on cardiovascular outcomes.
AB - Comprehensive cardiac rehabilitation for coronary patients includes a systematic
approach to the measurement and treatment of coronary risk factors, along with
the better-known exercise training component. Studies of exercise and nutritional
interventions in patients with coronary heart disease have documented improved
primary outcomes of decreased morbidity and mortality, decreased symptoms, and
fewer cardiac rehospitalizations. Quality of life, depression scores, and
physical functioning are improved after rehabilitation.
PMID- 10685139
TI - Putting prevention into daily practice.
AB - The future holds promise for expanding preventive therapies to reduce
cardiovascular risk. These preventive concepts are supported by sound science and
strong evidence from multiple randomized clinical trials. To be successful, the
health care system must continue to provide financial resources to support
physicians and other health care providers in preventive cardiovascular efforts.
In the long run, this support should result in a decrease in the need for
expensive high-technology, acute-care interventions. Health care provider teams
involving physicians, nurses, and other providers will be necessary to ensure the
success of these measures, and they must be integrated into the expanding network
of inpatient and outpatient delivery systems. Finally, programs to train fellows,
residents, and medical students in preventive skills will provide the basis for
expanded application of cardiovascular risk therapies and contribute to the
ultimate widespread success in decreasing the morbidity and mortality from
cardiovascular disease.
PMID- 10685140
TI - A concise review of the cost-effectiveness of coronary heart disease prevention.
AB - Coronary heart disease is one of the largest sources of morbidity, mortality, and
health care expenditure in the United States. This article reviews a number of
studies that estimate the cost per unit of health benefits associated with
different primary and secondary prevention strategies for coronary heart disease.
Although prevention does not provide a panacea for rising health care spending,
many preventive strategies are cost-effective when compared to other common
clinical interventions. Prevention should be incorporated into regular clinical
practice.
PMID- 10685141
TI - Embryology, anatomy, and surgical applications of the preperitoneal space.
AB - The preperitoneal space is presented from an embryologic, anatomic, and surgical
standpoint in detail. Because this space is one of the most used areas for the
repair of groin hernias, knowledge of its embryology and anatomy is essential.
PMID- 10685142
TI - Transversalis fascia rediscovered.
AB - The transversalis fascia is a layer in the make-up of the posterior inguinal
wall. It is the deepest, thinnest, and least important layer in terms of the
prevention of herniation. It is a segment of the wider endoabdominal fascia. The
true posterior wall of the inguinal canal is formed, in varying degrees, by the
muscles or aponeuroses of the internal oblique and transversus abdominis.
Plainly, Daedalus was not needed to show surgeons and anatomists how to make a
labyrinth out of a rabbit hole!
PMID- 10685143
TI - The inguinofemoral area from a laparoscopic standpoint. History, anatomy, and
surgical applications.
AB - No significant difference has been found between early and new diagrams of the
posterior anatomy of the inguinofemoral area from a laparoscopic standpoint
because anatomy is unique to each individual. But new dangers can arise from new
approaches, even if the anatomic structures are well known, so anatomic research
is still useful. It provides, relative to new surgical techniques, new vision of
structures known for centuries.
PMID- 10685144
TI - The inguinal rings.
AB - The inguinofemoral area constitutes the frontier between the abdomen and the
lower limb. Because of the human standing position, the inguinal region is a zone
supporting the abdominal thrust, and is weakened by the orifice of the inguinal
and femoral passages. Peritoneal diverticula may externalize into these orifices,
leading to the formation of hernias. This article reviews the anatomic
constituents of the inguinofemoral region and the anatomic basis for the
treatment of hernias.
PMID- 10685145
TI - Obturator hernia. Embryology, anatomy, and surgical applications.
AB - Obturator hernia is a rare clinical entity. In most cases, it produces small
bowel obstruction with high morbidity and mortality. The embryology, anatomy,
clinical picture, diagnosis, and surgery are presented in detail.
PMID- 10685146
TI - Embryologic and anatomic basis of esophageal surgery.
AB - The embryogenesis, congenital anomalies, and surgical anatomy and applications of
the esophagus for benign and malignant processes are detailed in this article.
Emphasis is placed on the role of embryology and the anatomy involved in surgical
decisions.
PMID- 10685147
TI - Embryology and surgical anatomy of the mediastinum with clinical implications.
AB - This article discusses general mediastinal embryology, and provides anatomy and
algorithms for the investigation of mediastinal masses. The superior, anterior,
middle, and posterior mediastina also are detailed.
PMID- 10685148
TI - Embryologic and anatomic basis of duodenal surgery.
AB - The following points should be remembered by surgeons (Table 1). In writing about
the head of the pancreas, the common bile duct, and the duodenum in 1979, the
authors stated that Embryologically, anatomically and surgically these three
entities form an inseparable unit. Their relations and blood supply make it
impossible for the surgeon to remove completely the head of the pancreas without
removing the duodenum and the distal part of the common bile duct. Here
embryology and anatomy conspire to produce some of the most difficult surgery of
the abdominal cavity. The only alternative procedure, the so-called 95%
pancreatectomy, leaves a rim of pancreas along the medial border of the duodenum
to preserve the duodenal blood supply. The authors had several conversations with
Child, one of the pioneers of this procedure, whose constant message was to
always be careful with the blood supply of the duodenum (personal communication,
1970). Beger et al popularized duodenum-preserving resection of the pancreatic
head, emphasizing preservation of endocrine pancreatic function. They reported
that ampullectomy (removal of the papilla and ampulla of Vater) carries a
mortality rate of less than 0.4% and a morbidity rate of less than 10.0%.
Surgeons should not ligate the superior and inferior pancreaticoduodenal arteries
because such ligation may cause necrosis of the head of the pancreas and of much
of the duodenum. The accessory pancreatic duct of Santorini passes under the
gastrointestinal artery. For safety, surgeons should ligate the artery away from
the anterior medial duodenal wall, where the papilla is located, thereby avoiding
injury to or ligation of the duct. "Water under the bridge" applies not only to
the relationship of the uterine artery and ureter but also to the gastroduodenal
artery and the accessory pancreatic duct. In 10% of cases, the duct of Santorini
is the only duct draining the pancreas, so ligation of the gastroduodenal artery
with accidental inclusion of the duct is catastrophic. With the Kocher maneuver,
surgeons reconstruct the primitive mesoduodenum and achieve mobilization of the
duodenum, which is useful for some surgical procedures. Surgeons should not
skeletonize more than 2 cm of the first part of the duodenum. If more than 2 cm
of skeletonization is done, a duodenostomy using a Foley catheter may be
necessary to avoid blow-up of the stump secondary to poor blood supply. Proximal
duodenojejunostomy is advised for the safe management of patients with difficult
duodenal stumps. Roux-en-Y choledochojejunostomy and duodenojejunostomy divert
bile and food in the treatment of the complicated duodenal diverticulum. The
suspensory ligament may be transected with impunity. It should be ligated before
being sectioned so that bleeding from small vessels contained within can be
avoided. Failure to sever the suspensory muscle completely, which is possible if
the insertion is multiple, fails to relieve the symptoms of vascular compression
of the duodenum (Fig. 18). Mobilization, resection, and end-to-end anastomosis of
the duodenal flexure have been performed as a uniform surgical procedure,
avoiding the conventional gastrojejunostomy. With a large, penetrating posterior
duodenal or pyloric ulcer, surgeons should remember that The proximal duodenum
shortens because of the inflammatory process (duodenal shortening) The anatomic
topography of the distal common bile duct and the opening of the duct of
Santorini and the ampulla of Vater is distorted Leaving the ulcer in situ is wise
Careful palpation for or visualization of the location of the ampulla of Vater or
common bile duct exploration with a catheter insertion into the common bile duct
and the duodenum are useful procedures In most cases, the common bile duct is
located to the right of the gastroduodenal artery at the posterior wall of the
first part of the duodenum. (ABSTRACT TRUNCATED)
PMID- 10685149
TI - Ampulla of Vater. Anatomic, embryologic, and surgical aspects.
AB - The region of the ampulla of Vater constitutes a complex anatomic and functional
entity, the biliopancreaticoduodenal confluence, of which the essentials of this
rapid review are the: Variation in site of implantation of the greater duodenal
papilla, whereas the relations between the common bile duct and the main
pancreatic duct are relatively constant Presence at this site of a weak point in
the duodenal wall, commonly the site of mucosal diverticula Interdependence of
the parietal duodenal mucosa and the sphincteric system of Oddi Existence of an
extramural zone of this sphincter, which should be the only one involved in
sphincterotomy Danger of wide excisions of the papilla, which, apart from the
risk for hemorrhage, cause a breach of the digestive barrier The ampulla of Vater
corresponds to the dilated junction of the common bile duct and main pancreatic
duct, if present. The ampulla is an extensive anatomic and functional region that
includes not only the choledochopancreatic junction but also the sphincter of
Oddi, the whole traversing the duodenal wall to open at the greater duodenal
papilla. The chief anatomic features of this biliopancreaticoduodenal junction
have been reviewed, forming the basis of techniques of surgical or endoscopic
sphincterotomies and localized excisions of vaterian tumors.
PMID- 10685150
TI - Surgical embryology and anatomy of the diaphragm with surgical applications.
AB - This article reviews the development, surgical anatomy, and teratology of the
diaphragm, and discusses the diagnostic procedures, surgical therapy, and
prognosis of congenital disturbances. Special attention is paid to the traumatic
rupture of the diaphragm, concerning incidence, cause, diagnosis, prognosis, and
surgical repair.
PMID- 10685151
TI - Functional anatomy of the gastroesophageal junction.
AB - The study of the functional anatomy of the gastroesophageal junction allows for
the demonstration of a double mechanism that combats the conflict of pressures
that tends to lead to gastroesophageal reflux. On one hand, the LES, an intrinsic
structure, is directly related to the muscle fibers of the organ and responds to
a neurohormonal physiologic command. On the other hand is an anatomic entity,
centered by the crura of the diaphragm, closely related to the movements of
respiration. These structures constitute a second, extrinsic sphincter that gives
rise to the zone of high pressure in the terminal esophagus. This role is
difficult to assess, and its importance is underestimated. The proper functioning
of these two mechanisms implies that the gastroesophageal junction remains in
place within the diaphragmatic channel of the esophagus. Also important are the
postural phenomena associated with the sloping position of the fundus. In
patients with gastroesophageal reflux, the decrease of the pressure measured in
the terminal esophagus accounts for the occurrence of reflux. Investigators
concede that, under the influence of abdominal straining, the gastroesophageal
junction tends to ascend into the diaphragmatic channel. The results are twofold:
(1) the muscle fibers of the lower esophagus relax, explaining the incompetence
of the intrinsic sphincter, and (2) the sphincteric zone is withdrawn from its
muscular diaphragmatic environment. Physicians should consider these structures
as a whole in approaching the surgical treatment of reflux. The construction of a
periesophageal valve has no anatomophysiologic basis. A gastropexy procedure must
be added to replace the gastroesophageal junction in its anatomic setting and
keep it there. This procedure also allows retightening of the muscle fibers of
the esophageal wall, which is essential in long-term surgical correction.
PMID- 10685152
TI - The salivary glands. Embryology, anatomy, and surgical applications.
AB - This article discusses the embryology and surgical treatment of diseases of the
salivary glands, which require precise knowledge of anatomy. Knowledge of the
course of the facial nerve enables safe removal of parotid tumors. The
submandibular gland is associated intimately with the lingual and hypoglossal
nerves.
PMID- 10685153
TI - The greater omentum. Anatomy, embryology, and surgical applications.
AB - The significance of the greater omentum has been discovered recently by surgeons
of various disciplines because it provides an excellent plastic material against
inflammation and irradiation and for repair of defects that can be applied in the
abdominal cavity; or it can be exteriorized and lengthened at a vascular pedicle
and detached using microvascular anastomoses. Anatomic features, such as the
volume of the omentum and the arrangement of the blood vessels, determine the
lines of dissection. The eminent omental potential and the different biochemical
and immunologic functions are unique, and can be related to specific anatomic
structures, some of which may be drawn back to its embryologic sources. The
ability of absorption and adhesion formation, neovascularization, and infection
defense by the omentum protects against irradiation damage, accelerates healing
of dead space, and improves the complication rate and quality of life after
application to a wound bed.
PMID- 10685154
TI - Appendix and cecum. Embryology, anatomy, and surgical applications.
AB - Surgeons should be familiar with surgery of the cecum and appendix because the
diseases of this region, especially appendicitis, are the most common indications
for surgical exploration. Usually, diagnosis of appendicitis and appendectomy are
not difficult, but atypical location of the appendix or other anatomic anomalies
can make the diagnosis of appendicitis and appendectomy difficult. In cases of
atypical anatomy or diffuse clinical picture, especially in young adults or
elderly patients, the spectrum of embryologic and anatomic anomalies must be kept
in mind to make the correct treatment decision for individual patients. If doubt
persists, explorative laparotomy must be performed to avoid overlooking rare,
acute, intra-abdominal abnormalities.
PMID- 10685155
TI - Embryology and anatomy of the anorectum. Basis of surgery.
AB - The rectum is a pelvic organ, complex in its morphology and its topographic
relationships. Its double embryologic origin explains the two types of tumors
that develop in the rectum: (1) lieberkuhnian adenocarcinoma in the pelvic rectum
and (2) squamous epithelioma in the anal canal. Its venous and lymphatic supply,
intensively developed, realizes early pathway of tumoral dissemination. The
pelvic relationships of the rectum and anus explain the technical difficulty of
rectal surgery, especially when subperitoneal resection and anastomosis are
concerned. Imaging of this area permits an early diagnosis of rectal tumors and
allows a less invasive surgery with a carcinologic precision.
PMID- 10685156
TI - Anatomic basis of hepatic surgery.
AB - Modern hepatic surgery is based on precise anatomic foundations. The importance
of this information applies to all levels of the diagnostic and therapeutic
chain. Modern methods of imaging--CT scanning, MR imaging, and preoperative
sonography--help physicians to detect variations and plan surgical excision.
PMID- 10685157
TI - Embryology, anatomy, and surgical applications of the extrahepatic biliary
system.
AB - As technology has improved and the ability to apply this technology in the
surgical arena has grown, surgeons have been able to perform more sophisticated
operative procedures. Hepatobiliary surgeons are now able to use laparoscopy,
immunosuppressive drugs, and technical advances in cryosurgery to accomplish
magnificent results. The success and safety of laparoscopic cholecystectomy,
orthotopic liver transplantation, and trisegmentectomy for hepatic tumors depend
on a high regard for and an accurate knowledge of the anatomy and some of the
common embryologic anomalies of the biliary tree. The blood supply, ductal
variations, and gallbladder anatomy of this area are often the source of major
challenge to unprepared and unaware surgeons. The authors have attempted to
stimulate an interest in, a respect for, and perhaps some desire to learn more
about the important and fascinating anatomy of this region.
PMID- 10685158
TI - Embryology, anatomy, and surgical applications of the kidney and ureter.
AB - This article discusses the embryology and anatomy of the kidney and ureter.
Surgical approaches, such as the lumbar and thoracoabdominal, are provided.
Operations for kidney (i.e., radical nephrectomy, nephroureterectomy, and partial
nephrectomy) and ureteric tumors also are discussed.
PMID- 10685159
TI - Surgical anatomy and embryology of the adrenal glands.
AB - Gross anatomy explains the different surgical approaches to adrenalectomy and the
difficulties encountered by surgeons during this procedure. Development of the
adrenal glands explains the location of the ectopic sites and excess hormone
production by adrenal tumors. The choice of a surgical approach is sometimes
difficult and is dependent on (1) the morphology of the body; (2) the volume of
the tumor, which necessitates immediate vascular control; and (3) the type of
disease, which may necessitate a complete exploration of the abdominal cavity.
PMID- 10685160
TI - Embryology, anatomy, and surgical exposure of the great abdominal vessels.
AB - This article describes the embryology of the abdominal aorta and the anatomic
features of its major visceral branches, including the celiac, superior
mesenteric, and inferior mesenteric arteries. The common anatomic variants of
these visceral vessels also are reviewed. Various operative techniques to gain
surgical exposure to these vessels are described.
PMID- 10685161
TI - Veterinary surgeon's guide to Australian bat lyssavirus.
AB - Veterinary surgeons in Australia must be aware of the emerging viral diseases and
their potential effects on public health generally and, more specifically, on the
veterinary profession. Australian bat lyssavirus was identified in 1996 and
causes rabies-like disease in bats and humans. Two humans from Queensland have
died of Australian bat lyssavirus encephalitis. Surveillance has shown that all
Australian bats must be considered carriers of this new virus, therefore
protective apparel should be used when handling bats. The pre-exposure regimen of
inactivated rabies vaccine (Pasteur Merieux) provides protection against
infection. As part of the preventive regimen, at risk groups, such as veterinary
surgeons, should seriously consider pre-exposure rabies vaccination. The post
exposure protocol involves administration of human rabies immunoglobulins and
five intramuscular injections of the inactivated rabies vaccine.
PMID- 10685162
TI - Postoperative performance of racing horses with tearing of the medial palmar
intercarpal ligament.
AB - OBJECTIVE: To examine the relationship between medial palmar intercarpal ligament
(MPICL) tearing and postoperative performance in racing horses. MATERIALS AND
METHODS: The postoperative performance of 42 horses in which the midcarpal joint
was examined arthroscopically was followed prospectively. Intra-articular
variables examined were the severity of MPICL tearing, subchondral bone damage
and articular cartilage damage. Using a scoring system based on the class of race
and the position in the race, a mean score was calculated for up to five races
before and after surgery. The preoperative score was subtracted from the
postoperative score to give a net score. Statistical analysis was by a Mann
Whitney U test and multiple linear regression. RESULTS: Thirty-two (76%) raced
postoperatively, 23 (55%) won at least one race and 12 of 26 (46%) performed at
the same or higher level. Horses with grades 2 to 4 MPICL tearing had
significantly lower net scores than those with grade 1 or no tearing. The
severity of subchondral bone damage was the only variable on its own that was
significantly correlated with net score (r2 = 0.23, P < 0.05). The addition of
the grade of MPICL tearing to bone damage significantly improved the prediction
of postoperative performance (P < 0.05). The inclusion of articular cartilage
damage had no effect on the prediction of postoperative performance. CONCLUSION:
Tears involving more than one third of the MPICL as observed arthroscopically
have a significant detrimental affect on postoperative performance of racing
horses.
PMID- 10685163
TI - Fungal pneumonia in a captive black rhinoceros.
AB - A captive black rhinoceros (Diceros bicornis) with a hoof abscess was treated
with long-term antibiotic therapy. After 9 months of treatment, there was rapid
deterioration, marked weight loss and reluctance to stand. Profuse, bilateral
epistaxis developed accompanied by collapse and the animal was euthanased.
Necropsy revealed pulmonary aspergillosis with concurrent Pseudomonas aeruginosa
infection. Though a well-recognized disease of black rhinoceros, fungal pneumonia
has not been reported in this species in Australia. The cost and efficacy of
treatment have been questioned, however, prophylactic antifungal drug
administration will be considered in any further cases of chronic, debilitating
illness in black rhinoceros at Western Plains Zoo.
PMID- 10685164
TI - Advantages and disadvantages of using alpha-2 agonists in veterinary practice.
PMID- 10685165
TI - Xylazine and medetomidine in small animals: these drugs should be used carefully.
PMID- 10685166
TI - Kinetics for clinicians.
PMID- 10685167
TI - Babesia and Ehrlichia seropositive horses temporarily imported into Australia.
PMID- 10685168
TI - Mortality of sheep exported by sea: evidence of similarity by farm group and of
regional differences.
AB - OBJECTIVE: To determine whether mortality of sheep exported by sea is similar for
sheep from the same farm exported in different years or is associated with the
region of origin. DESIGN: Mortalities were monitored in farm groups of sheep
exported from the southwest of Western Australia under normal commercial
conditions. PROCEDURE: Mortalities were monitored on commercial shipments from
1985 to 1996. For each consignment, the mortality rate was assigned its
percentile ranking within the month and year of loading of the ship. A mortality
rate was high if its percentile ranking was above a selected cut-off value. Five
cut-off values were used in separate analyses. The spatial distribution of farms
with high mortality was compared between and within zones of rainfall and length
of pasture-growing season. RESULTS: A total of 479 groups of sheep from 405 farms
was monitored. Mortality rates ranged from nil to 28.2%. Half of all deaths were
from 14.2% of the consignments. There was a significant association (P < 0.05)
between the category of mortality (high or low) in the first and second years of
monitoring for four of the five cut-off values. The spatial analyses indicated
that there were more high-mortality groups, and the average mortality was higher,
in the zones of higher rainfall and longer pasture-growing season (P < 0.001).
CONCLUSION: Mortality data can be used to identify regions and groups of sheep
that are at risk of suffering high death rates when exported by sea.
PMID- 10685169
TI - Effect of topical rh-TGF-beta 1 on second intention wound healing in horses.
AB - OBJECTIVE: To investigate the effects on wound healing of transforming growth
factor-beta 1 as a topical treatment to full-thickness, excisional wounds of the
distal limb of horses. DESIGN: A randomised block study using four horses, each
with wounds assigned to four treatment groups. ANIMALS: Four adult Standardbred
geldings. PROCEDURE: Four, 4 cm2, full-thickness wounds were created on the
dorsomedial and dorsolateral aspect of the metacarpus or metatarsus of each limb
of four horses, giving a total of 64 wounds. For each limb, wounds were randomly
assigned to four treatment groups: no treatment (control), carrier (Methyl
Cellulose gel), 50 ng/wound rhTGF-beta 1 in carrier, and 500 ng/wound rhTGF-beta
1 in carrier. Wounds were treated on day 0 and day 8. Effects of treatment were
evaluated on the basis of the presence of exuberant granulation tissue requiring
excision, number of times excision was required, total wound area, area of
epithelialisation, area of granulation, and histological evaluation of biopsy
samples of wounds on day 8 and excised wounds on day 21. RESULTS: Topical
application of TGF-beta 1 at the two concentrations studied had no significant
effect on the total area of wounds (P = 0.7), the area of granulation tissue (P =
0.78), the area of epithelialisation (P = 0.92), histological assessment or
subjective clinical assessment of wounds. CONCLUSION: TGF-beta 1 had no
beneficial effects on wound healing. Additional trials are needed to test if it
has value for wound treatment in horses.
PMID- 10685170
TI - Acute cortisol responses of lambs to ring castration and docking after the
injection of lignocaine into the scrotal neck or testes at the time of ring
application.
AB - OBJECTIVE: To test whether injecting lignocaine into the scrotal neck 5 to 10 s
before or into both testes immediately after ring castration and docking wound
significantly reduce the plasma cortisol response to castration and docking.
DESIGN: A physiological study with controls. PROCEDURE: Lambs were given one of
six treatments: control handling, injection of lignocaine into scrotal neck,
injection of lignocaine into both testes, ring castration and docking, ring
castration and docking after lignocaine was injected into the scrotal neck, and
ring castration and docking before lignocaine was injected into both testes.
Blood samples were taken before and regularly after treatment and analysed for
plasma cortisol concentrations. RESULTS: The plasma cortisol concentrations of
lambs castrated and docked after lignocaine had been injected into the scrotal
neck were significantly lower between 20 and 60 min after treatment than in lambs
castrated and docked without local anaesthesia. Injecting lignocaine into the
testes after ring application did not significantly reduce the cortisol response
to ring castration and docking. CONCLUSIONS: Lignocaine injected into the scrotal
neck 5 to 10 s before ring castration will reduce the cortisol response and by
inference the pain associated with ring castration.
PMID- 10685171
TI - Tail docking and beliefs about the practice in the Victorian dairy industry.
AB - OBJECTIVE: To determine the occurrence of tail docking and beliefs about the
practice in the Victorian dairy industry. DESIGN: Survey responses were analysed
using chi-square tests and by correlation and regression analyses to determine
associations between husbandry practices and beliefs and to identify possible
predictive variables in relation to docking. PROCEDURE: A survey of the
occurrence of docking and beliefs about the practice was conducted in 1997 using
face-to-face interviews of 313 respondents at 234 Victorian dairy farms. RESULTS:
On average, 35% of dairy farms routinely docked cattle. The practice varied from
11 to 63% in different regions and 12% of stud farms docked their cows. Rubber
rings were used on 75% of farms and the average age of the cow at docking was 18
months. Twenty-two percent of cows were docked at a level above the top of the
udder and 54% were docked level with the top of the udder. Respondents that
docked believed that milking was finished quicker, the risks of leptospirosis for
the operator and mastitis for the cow were reduced, the cows were easier to
handle, fly numbers were reduced and milk quality was improved. There was a
general belief that intact tails could cause significant discomfort to the
operator and that docking resulted in acute but not chronic pain. CONCLUSIONS:
Docking is an entrenched practice in the Victorian dairy industry. Those farmers
who docked generally believed that it was a highly desirable farming practice
with particular benefits for the operator.
PMID- 10685172
TI - Effect of breed of cattle on innate resistance to infection with Anaplasma
marginale transmitted by Boophilus microplus.
AB - OBJECTIVE: To assess the innate resistance of and transmission in naive Bos
taurus cross Bos indicus and purebred Bos indicus cattle when placed in a paddock
with cattle infected with Anaplasma marginale and carrying Boophilus microplus
ticks. DESIGN: A group of 49 purebred B indicus, and 48 B indicus cross B taurus
(50%, F1 generation) 24-month-old steers were kept in the same paddock with
cattle artificially infected with a virulent isolate of A marginale and Boophilus
microplus. The cattle were seronegative for A marginale at the start of the trial
but had previously been exposed to Babesia bovis and B bigemina. PROCEDURE:
Cattle were inspected twice weekly for 118 days. Whole blood, blood smears and
serum samples were collected from the cattle on day 37 after exposure and then at
regular intervals to day 83 after exposure to measure packed-cell volumes,
parasitaemias and antibody titres to A marginale. Any animals that met preset
criteria were treated for anaplasmosis. On day 83 all cattle were treated with an
acaricide and cattle infected with A marginale were removed from the rest of the
group. RESULTS: A marginale was detected in blood smears from 14 crossbred and 9
B indicus steers between days 56 and 72 after exposure. Five and two of the
infected crossbred and B indicus steers required treatment, respectively. One of
the Bos indicus cattle died as a result of the A marginale infection despite
treatment. Antibodies to A marginale were detected in the 23 infected cattle. The
mean packed-cell volume depression was 40 and 37% in the affected crossbred and
Bos indicus groups, respectively. There was no significant difference detected in
susceptibility between these two groups. CONCLUSIONS: Innate resistance of
purebred B indicus and crossbred cattle was not significantly different. The
results confirm that purebred B indicus and crossbred cattle are sufficiently
susceptible to warrant the use of vaccination against Anaplasma infections.
PMID- 10685173
TI - Maxillary deformity in a wild platypus (Ornithorhynchus anatinus).
PMID- 10685174
TI - Courts ignore reality.
PMID- 10685175
TI - Tail docking lies.
PMID- 10685176
TI - Microchipping--why worry?
PMID- 10685177
TI - EU beef wars expose sewage sludge scandal.
PMID- 10685178
TI - Cutaneous phycomycosis in two horses.
PMID- 10685179
TI - Anorexia and an abdominal mass in a cat.
PMID- 10685180
TI - Ulceration and stricture of the right dorsal colon after phenylbutazone
administration in four horses.
AB - Four cases of ulceration and stricture of the right dorsal colon were
encountered. Ulceration of the right dorsal colon is generally associated with
nonsteroidal anti-inflammatory drug (NSAID) toxicosis but there are few reports
of stricture following ulceration. All four horses had recent phenylbutazone use:
three had been given doses well in excess of the recommended dose and in one the
dose was marginally above those recommended but was combined with administration
of other NSAIDs. All four horses presented with intermittent low-grade colic,
weight loss and ventral oedema. Diarrhoea was also seen in three of them. All had
hypoproteinaemia due to severe hypoalbuminaemia, and hyperfibrinogenaemia.
Hypoalbuminaemia was less severe in one horse and this horse was successfully
managed medically. Two cases were definitively diagnosed at exploratory celiotomy
and two at necropsy. Exploratory celiotomy was performed in two horses: one was
euthanased at surgery and one was managed successfully with medical treatment and
remained normal 1 year after surgery. Medical management included feeding of a
low-roughage pelleted ration, corn oil, psyllium mucilloid, and discontinuation
of NSAID administration.
PMID- 10685181
TI - The distribution and identification of dangerously venomous Australian
terrestrial snakes.
AB - The identification of dangerous Australian snakes is important in instituting
therapy for envenomation. Despite the availability of a number of identification
guides with varying degrees of generality, identification can be problematic for
several reasons. These include a diversity of common names, many of which are
inappropriate or regionally applied to different species, identification keys
that focus on variable features, intraspecific variation and interspecific
convergence in colouration, and recent changes in scientific nomenclature of
species and genera. Geographic distribution of the dangerously venomous species
can be a useful aid to identification, by limiting the range of options in a
region. However, delineation of the limits of distribution relies on fine scale
mapping beyond the resolution of most identification guides. This article
provides a summary of the geographic limits of the dangerously venomous
Australian snakes, with particular emphasis on major population centres, and
clarifies some problems in identification, particularly among brown-coloured
snakes.
PMID- 10685182
TI - Cytology and histopathology of canine leproid granuloma syndrome.
AB - OBJECTIVE: To describe the histopathology of canine leproid granuloma syndrome.
DESIGN: Histological examination of biopsy specimens taken from dogs with leproid
granuloma syndrome. Biopsies were acquired from four veterinary pathology
practices after initial examination showed acid-fast bacilli or lesions
suggestive of a mycobacterial aetiology. Tissue from 30 cases formed part of a
retrospective survey while a further 7 cases were obtained prospectively.
PROCEDURE: Tissue samples were fixed in formalin and paraffin embedded. Sections
were stained with haematoxylin and eosin and Ziehl-Neelsen stains. Slides were
evaluated for the type of inflammatory response and the number of bacteria. In a
few cases smears made from crush preparations and needle aspirates were stained
with DiffQuik and acid-fast stains. RESULTS: The common cytological feature seen
in DiffQuik stained smears was numerous, often spindle-shaped, macrophages with
variable numbers of lymphocytes and plasma cells and lower numbers of
neutrophils. Usually few to moderate numbers of medium length bacilli were
detected within macrophages or extracellularly. Histologically, lesions were
chiefly pyogranulomatous within the subcutis and dermis. Pyogranulomas were
composed chiefly of epithelioid macrophages and neutrophils but plasma cells and
small lymphocytes were scattered throughout the lesions in which giant cells were
seen. Lesions were pyogranulomatous in 36 cases and granulomatous with small
suppurative foci in one. The numbers of acid-fast bacilli present were very low
to low in 22 cases, moderate in 6 and regionally numerous to numerous in 9.
Bacteria were pleomorphic, ranging from long, slender filaments in parallel
sheaves to short and variably-beaded bacilli or highly beaded to coccoid
organisms. The morphology was more uniform in DiffQuik stained smears than in
fixed tissue sections. CONCLUSION: The pathology of canine leproid granuloma
syndrome is highly uniform and is suggestive of saprophytic mycobacterial
involvement. The morphological diversity of acid-fast bacilli probably results
from differences in staining characteristics rather than indicating different
species of Mycobacterium. While approximately half of the cases had only few
organisms present, the veterinary practitioner using a Romanovsky stain such as
DiffQuik on aspirated material might expect to obtain a rapid diagnosis in many
cases. This would allow differentiation of the syndrome from neoplastic and other
diseases of the skin and direct appropriate treatment at the initial
presentation.
PMID- 10685183
TI - Extent and economic effect of heat loads on dairy cattle production in Australia.
AB - OBJECTIVE: To investigate the extent of heat load problems, caused by the
combination of excessive temperature and humidity, in Holstein-Friesian cows in
Australia. Also, to outline how milk production losses and consequent costs from
this can be estimated and minimised. PROCEDURES: Long-term meteorological data
for Australia were analysed to determine the distribution of hot conditions over
space and time. Fifteen dairy production regions were identified for higher
resolution data analysis. Both the raw meteorological data and their integration
into a temperature-humidity thermal index were compiled onto a computer program.
This mapping software displays the distribution of climatic patterns, both
Australia-wide and within the selected dairying regions. Graphical displays of
the variation in historical records for 200 locations in the 15 dairying regions
are also available. As a separate study, production data from research stations,
on-farm trials and milk factory records were statistically analysed and
correlated with the climatic indices, to estimate production losses due to hot
conditions. RESULTS: Both milk yields and milk constituents declined with
increases in the temperature-humidity index. The onset and rate of this decline
are dependent on a number of factors, including location, level of production,
adaptation, and management regime. These results have been integrated into a farm
level economic analysis for managers of dairy properties. CONCLUSION: By
considering the historical patterns of hot conditions over time and space, along
with expected production losses, managers of dairy farms can now conduct an
economic evaluation of investment strategies to alleviate heat loads. These
strategies include the provision of sprinklers, shade structures, or combinations
of these.
PMID- 10685184
TI - Haematological, serum biochemical and serological features of platypuses with and
without mycotic granulomatous dermatitis.
AB - OBJECTIVE: To determine whether there are haematological, serum biochemical and
serological differences between platypuses (Ornithorhynchus anatinus) with and
without granulomatous dermatitis due to Mucor amphibiorum infection. An
additional objective was to establish reference haematological and serum
biochemical ranges for the species in Tasmania. DESIGN: A clinicopathological and
serological study. ANIMALS: A total of 37 free-living adult platypuses captured
from streams and dams in Northern Tasmania were used in the clinicopathological
study. Twenty-seven were clinically normal and 10 had mycotic granulomatous
dermatitis. A total of 22 platypuses (20 adult and 2 juvenile) were used for the
serosurvey. Eighteen were captured from streams in Northern Tasmania, and four
were submitted for necropsy. RESULTS: Platypuses with mycotic ulcerative
dermatitis had significantly smaller packed red cell volumes, haemoglobin
concentrations, lymphocyte counts, serum cholesterol and calcium concentrations,
and higher serum globulin and potassium concentrations than clinically normal
animals. The lymphopenia and hyperkalaemia were thought to be clinically
significant. Numbers of Trypanosoma binneyi in blood smears were similar between
the two groups. Diseased platypuses had higher concentrations of serum antibody
against Mucor amphibiorum as determined by ELISA compared to clinically normal
platypuses. CONCLUSION: Platypuses affected by mycotic granulomatous dermatitis
showed haematological and serum biochemical changes when compared to clinically
normal animals from the same Tasmanian sites. A serological survey may be a
useful method for detecting the prevalence of exposure to Mucor amphibiorum and
humoral immunity in platypus populations both in Tasmania and the mainland of
Australia.
PMID- 10685185
TI - Presence of cervical vertebral malformation in Dobermann puppies and the effects
of diet and growth rate.
AB - OBJECTIVE: To investigate the relationship between diet, growth rate and the
presence of caudal cervical malformation in Doberman puppies. DESIGN: A
prospective study of 15 Dobermann puppies from three unrelated litters, aged from
0 to 16 weeks. PROCEDURE: The growth rate in terms of body weight gain and
increase in ulna length were measured weekly for all puppies. In addition the
nutritional quality of the diets was assessed. Radiographs of the cervical spine
were taken at 6 and between 12 and 16 weeks of age and examined for the presence
of caudal cervical vertebral malformation. A mixed model for repeated measures
data was used to investigate the relationship between the growth rate of the
puppies and the fixed effects age, dam, diet, gender and presence of caudal
cervical malformation. RESULTS: Five of the puppies had changes consistent with
caudal cervical malformation. The diets fed were either balanced or transiently
deficient in protein, calcium, phosphorus and/or magnesium. There was no
significant association between growth rate and the variables dam, gender and the
presence of caudal cervical vertebral malformation. There was no significant
association between diet and increase in ulna length, but a trend existed between
body weight gain and the feeding of a balanced diet (P = 0.0672). CONCLUSION:
Caudal cervical vertebral changes can be detected radiographically as early as 6
weeks of age in some Dobermann puppies. A balanced diet and growth rate are not
significant factors in its initial development.
PMID- 10685186
TI - Listeria in zoo animals and rivers.
PMID- 10685187
TI - Osmotic fragility of erythrocytes in periparturient yaks.
PMID- 10685188
TI - Food safety a major AFFA priority.
PMID- 10685189
TI - Giving evidence in court appearances.
PMID- 10685190
TI - Draft statement on registration to practise as a veterinarian.
PMID- 10685191
TI - Take a stand AVA.
PMID- 10685192
TI - Hounding PetPEP.
PMID- 10685193
TI - Comprehensive perinatal centers in the era of managed care.
PMID- 10685195
TI - Serum cortisol levels in very low birth weight infants of substance-abusing
mothers.
AB - OBJECTIVE: Recently, hypoadrenalism was described in extremely low birth weight
infants. We have been measuring serum cortisol levels in very low birth weight
(VLBW) infants to assess their adrenal function. It was noticed that infants of
substance-abusing mothers (ISAM) had unusually high serum cortisol levels. To our
knowledge, there are no data regarding serum cortisol levels in VLBW ISAM. The
objective of our study was to determine if serum cortisol levels of VLBW ISAM are
different from serum cortisol levels in VLBW infants without a history of
maternal substance abuse. METHODS: We reviewed medical records of infants with
birth weight between 400 and 1300 gm who were born between July 1994 and June
1995. Seven ISAM who had serum cortisol levels drawn before 48 hours of life were
identified. Seven infants matched for gestational age, antenatal steroid
exposure, and birth weight served as control infants. Clinical characteristics,
serum cortisol levels, and clinical outcome were compared between the two groups.
Serum cortisol levels of all infants were measured by radioimmunoassay. RESULTS:
The mean birth weight of the ISAM group was 834 gm (range 480 to 1175 gm), and
the mean gestational age was 27.4 weeks. The mean birth weight of the control
group was 921 gm (range 525 to 1230 gm) with a mean gestational age of 27.8
weeks. The mean serum cortisol level of the ISAM group was 65.3 micrograms/dl
(range 11.9 to 144 micrograms/dl); it was significantly higher than that of the
control group (mean cortisol level of 20.5 micrograms/dl; range 4.9 to 62.7
micrograms/dl) (p = 0.01, two-tailed). CONCLUSION: Our data suggest that maternal
substance abuse significantly increases serum cortisol levels in VLBW infants.
Studies in larger scale are needed to confirm our findings and to correlate
cortisol levels in this group of patients with clinical outcome.
PMID- 10685194
TI - The New Hampshire Perinatal Program: twenty years of perinatal outreach
education.
AB - OBJECTIVE: To describe 20 years of regional outreach education by the New
Hampshire Perinatal Program, its interaction with all 26 community hospitals in
the state with maternity services and an additional four in adjoining Vermont.
STUDY DESIGN: This paper describes educational initiatives responsive to the
needs of perinatal physicians and nurses. The core of the program is the
transport conference held annually at each referring hospital in which maternal
fetal and infant referrals are discussed. There are additional community hospital
based programs, programs at convenient locations in the region and medical center
conferences and skills programs. RESULTS: The program annually awards 10,000
continuing medical education credits (CME) and nursing contact hours. Evaluation
and feedback from all participants is encouraged. New Hampshire has one of the
lowest perinatal mortality rates in the county, which reflects in part the
accomplishments of the program. CONCLUSION: Perinatal outreach education is a
shared responsibility of providers in both the academic center and community
hospitals and is necessary to ensure optimal care for mothers and infants.
PMID- 10685196
TI - Rates of successful vaginal delivery after cesarean for patients with private
versus public insurance.
AB - OBJECTIVE: To examine the effect of insurance status on method of delivery while
controlling for clinical and sociodemographic characteristics of women delivering
at a single medical center. STUDY DESIGN: Sociodemographic and clinical
characteristics of 878 women, who delivered their infants between 1985 and 1991
at a university hospital, were analyzed. Women were included if their previous
infant was delivered by cesarean section and if the current pregnancy was > or =
37 weeks' gestation at nonemergent delivery with insurance status clearly
specified. The outcome of interest was the rate of successful vaginal births
after cesarean (VBAC) delivery by insurance status. RESULTS: The trial of labor
rate for the cohort, defined as the rate of VBAC or cesarean deliveries following
labor, was 55%; 61% were vaginal deliveries. Significant differences with regard
to insurance status and several maternal factors were noted between trial of
labor and cesarean section--no labor groups. After controlling for potentially
confounding variables, the Medicaid/indigent group was more likely than the
privately insured group to undergo a trial of labor (odds ratio, 1.5; 95%
confidence interval, 1.1 to 2.4). Of women who underwent a trial of labor, after
controlling for other characteristics, the Medicaid/indigent group was more
likely than the privately insured group to deliver vaginally (odds ratio, 1.9;
95% confidence interval, 1.1 to 3.2). CONCLUSION: After controlling for other
covariables, women with a history of a prior cesarean section with
Medicaid/indigent insurance were more likely than privately insured women to
attempt a trial of labor, and subsequently, to deliver vaginally, given that a
trial of labor was attempted.
PMID- 10685197
TI - Readmission for group B streptococci or Escherichia coli infection among full
term, singleton, vaginally delivered neonates after early discharge from Florida
hospitals for births from 1992 through 1994.
AB - BACKGROUND: In Florida during the period 1992 through 1994, there was a major
drop in the length of stay for full-term, singleton, vaginally delivered newborn
babies in the hospital. A major concern on the part of clinicians has been the
potential of an increased risk of sepsis (manifesting itself after discharge)
associated with earlier newborn discharge from the hospital. We used the Florida
hospital discharge dataset to study the frequency of readmission with sepsis
after early newborn discharge to home. METHODS: Using the Florida Agency for
Health-Care Administration Acute Care Hospital Discharge Dataset, we used a
multivariate, probabilistic matching algorithm to merge newborn discharge records
for births from 1992 through 1994 with readmission discharge records (including
hospital-to-hospital transfers and multiple readmissions) during the first 28
days of life. We used the resulting merged dataset to study bacterial infection
diagnoses on newborn and readmission records and to examine relationships between
readmission diagnoses and timing of newborn discharge among the 364,528 full
term, singleton, vaginally delivered babies (FTSVDBs) without congenital
anomalies from 1992 through 1994 in Florida acute-care hospitals. RESULTS:
Overall, 86.3% of all FTSVDBs born in Florida acute-care hospitals were
discharged between day of life (DOL) 0 (born and discharged the same day) and DOL
2 (discharged two calendar days after birth). The group B streptococci (GBS)
infection code was found on the newborn discharge records of 9.2 per 10,000
FTSVDBs over the 3-year period, 5.9% of which involved hospital-to-hospital
transfer of the baby. Escherichia coli infection codes were found on the records
of 3.4 per 10,000 FTSVDBs over the 3-year period, 2.3% of which involved hospital
to-hospital transfer of the baby. Of those FTSVDBs discharged to home without
infection codes during DOL 1 to 2, 0.8 per 10,000 were readmitted within 7 days
(inclusive) with GBS infection, and 2.0 per 10,000 with E. coli infection. When
the data for readmitted babies were pooled for 1992 through 1994, the odds ratio
for probability of readmission comparing discharges on DOL 1 to DOL 2 for GBS was
2.27 (95% confidence interval, 1.83 to 2.70), and for E. coli 2.16 (95%
confidence interval, 1.46 to 2.85). Over this 3-year period, for babies
discharged on DOL 1, there was a 115% increase in the rate of readmission for GBS
from 1992 through 1994 (p < 0.01) and a 36.5% increase in the rate of readmission
for E. coli (p < 0.05). However, among FTSVDBs discharged on DOL 2, the rate of
readmission for both GBS and E. coli did not change during the period 1992
through 1994. There were no deaths among FTSVDBs as either newborns, transfers,
or readmissions within 7 days of discharge, with either GBS or E. coli infection
codes on their discharge record. CONCLUSION: From 1992 through 1994, the
increased number of babies discharged early in Florida was temporally associated
with an increased rate of readmission during the week after discharge for both
GBS and E. coli infection among babies discharged on the calendar day after
birth. With an increase in both the number of babies exposed to the risks of
early discharge, and an increased rate of these serious infections during the
week after discharge from the hospital, the number of these babies grew to
exceed, by several fold, the number of babies with inborn errors of metabolism
picked up by state screening programs.
PMID- 10685198
TI - Use of delayed pushing with epidural anesthesia: findings from a randomized,
controlled trial.
AB - OBJECTIVE: To compare outcomes between women receiving epidural anesthesia
assigned to a group following either a 1-hour "delayed" pushing protocol or
directed to initiate pushing at full cervical dilation. STUDY DESIGN: Using a
randomized, controlled design, multivariate analyses were used to evaluate second
stage labor duration and Apgar scores. An estimated odds ratio equation evaluated
fetal descent progress. RESULTS: A 13.68-minute difference occurred in second
stage labor length (p = 0.225). No differences were found in Apgar scores (p >
0.09). An estimated odds ratio, that progress in terms of one fetal station unit
would occur for control group subjects as compared with subjects with similar
progress in the experimental group, was 1.51 (95% confidence interval: 1.16,
1.95). CONCLUSION: Second stage labor was not significantly lengthened, and a
similar rate of fetal descent occurred in the absence of directed pushing.
Findings support further research on the potential advantages of minimizing the
duration of pushing in labor.
PMID- 10685199
TI - Skin care practices in the neonatal nursery: a clinical survey.
AB - OBJECTIVE: To survey the details of skin care practices in a sample of level I,
II, and III nurseries in the United States. DESIGN: A survey conducted by written
questionnaire, personal inspection, and phone contact. PARTICIPANTS: Information
was obtained from staff physicians and nurses about routine neonatal skin care
practices, including bathing, cord care, emollient use, diapering, use of
antimicrobial skin preparations, management of intravenous infiltration, approach
to diaper rash, and methods used to minimize transcutaneous water loss. SETTING:
Fifteen nurseries from twelve hospitals in four states were surveyed. RESULTS:
Among the nurseries surveyed, we found no uniform approach to skin care. Only two
individual maneuvers were consistently performed in all the nurseries: criteria
for bathing and skin antisepsis with povidone-iodine. Other than these, a wide
range of practices and products were used, some with a high ratio of risk and/or
cost to benefit. CONCLUSION: A better understanding of the principles of infant
skin care and a more uniform approach to skin care in the neonatal nursery can
minimize risks and costs to this special population of patients.
PMID- 10685200
TI - Neonatal seizures: incidence, onset, and etiology by gestational age.
AB - OBJECTIVE: To examine the influence of gestational age on seizures in the
neonatal intensive care unit. STUDY DESIGN: A cohort of 4165 neonates admitted to
a university intensive care unit between 1986 and 1995. The incidence, time of
onset, and etiology of neonatal seizures in the cohort were distributed by
gestational age. Logistic regression and t test were used to examine the
relationship between gestational age and seizures in the neonatal intensive care
unit. RESULTS: Seizures occurred in 356 (8.6%) infants. The seizure rate was
parabolically related to gestational age, such that infants at 30 to 36 weeks'
gestation had a 4.8% rate compared with 11.9% and 14.1% rates for infants < 30
and > 36 weeks, respectively (p < 0.001). Seizures manifested earlier in infants
< 30 weeks (2.3 +/- 5.6 days of life) and > 36 weeks (3.7 +/- 8.7 days)
gestational age compared with neonates 30 to 36 weeks (10.4 +/- 14.5 days) (p <
0.001). Intraventricular hemorrhage was the principal etiology underlying the
higher seizure rate for infants < 30 weeks (p < 0.001). Hypoxic-ischemic
encephalopathy and congenital malformations were primary factors for infants > 36
weeks (p < 0.01). Nervous system infections were evenly distributed across
gestational age. CONCLUSION: Gestational age exerts a considerable influence on
the incidence, onset, and etiology of neonatal seizures.
PMID- 10685201
TI - Heart rate and oxygen saturation correlates of infant apnea.
AB - OBJECTIVE: To analyze the effects of apnea duration on changes in heart rate and
oxygen saturation and to examine the temporal relationships among these
variables. STUDY DESIGN: An event analysis sheet was designed to analyze numerous
variables reflecting changes in heart rate and oxygen saturation associated with
infant apnea. From July 1, 1991 through June 30, 1992 we identified 32 infants
enrolled in The Infant Apnea Program at St. Peter's Medical Center, New
Brunswick, NJ who had apnea > or = 15 seconds in duration on consecutive 12-hour
multichannel recordings of heart rate, thoracic impedance, nasal thermistry, and
oxygen saturation. The apnea epochs of these patients were subdivided into apnea
of short (10 to 14 seconds), medium (15 to 19 seconds), and long (> or = 20
seconds) duration, and a total of 236 apnea epochs were analyzed. The
significance of differences was assessed by analysis of variance and Newman-Keuls
multiple comparisons. RESULTS: We found that the duration of apnea has
significant effects on perturbations in both heart rate and oxygen saturation,
however, the degree of oxygen desaturation can not be predicted by the
perturbation in heart rate. Analysis of the temporal relationship of apnea,
bradycardia, and oxygen desaturation reveals that, although apnea precedes both
heart rate and oxygen saturation drops in most infants as the length of apneic
interval increases, the interval between apnea onset and associated drops in
heart rate and/or oxygen saturation also increases. CONCLUSION: Oxygen saturation
monitoring may provide important physiologic data that can not be assessed by
cardiorespiratory monitoring alone.
PMID- 10685202
TI - Developmental care teams in the neonatal intensive care unit: survey on current
status.
AB - Developmental Care Teams (DCT) have evolved in Neonatal Intensive Care Units
(NICUs) in response to mounting evidence that developmental care is cost
effective and improves outcomes of critically ill newborns. Lack of national
practice guidelines and standardized roles for DCT members prompted formulation
and distribution of a questionnaire to obtain information regarding staff
membership of DCTs, budgeting for DCTs, utilization of developmental care in
practice, and education and developmental training of NICU staff. Questionnaires
were sent to 50 NICUs in 30 states, with a return rate of 62% (31 of 50),
representing 18 different states. Of those who responded, 64% had a DCT, and an
additional 24% were in various phases of starting a team. Forty-three percent of
the teams meeting on a regular basis did so monthly. Only 30% of those with a DCT
had a dedicated budget to cover operating costs of their developmental program.
Fifty-two percent of respondents had Neonatal Individualized Developmental Care
and Assessment Program (NIDCAP)-certified staff at their institutions; however,
nine other types of developmental specialists were also listed. Only four
respondents indicated utilization of set criteria for initiation of a DCT
consult, and 74% of those with DCTs initiated consults "when the need arises."
NIDCAP assessments were used for parent teaching (54%), care plans (69%), care
recommendations (46%), and at caregiver "discretion" (39%). The results of the
survey validated an intense interest in developmental care. Approach to
developmental care is variable between NICUs and implementation as outlined by
NIDCAP is unusual. Practical guidelines for utilization and funding of DCTs are
needed.
PMID- 10685203
TI - The impact of personal problems on accessing prenatal care in low-income urban
African American women.
AB - OBJECTIVE: The purpose of this study was to investigate the nature and
contribution of personal factors related to the use of prenatal care in a sample
of high-risk women residing in an urban environment where care was accessible and
free. STUDY DESIGN: The sample consisted of 297 African American women with low
socioeconomic status and a high school education or less who were newly delivered
of neonates. The level of prenatal care was classified according to the Kessner 3
Parameter Index (adequate, intermediate, inadequate). Women who received no
prenatal care made up a fourth group. Subjects responded to the "Ten-Item
Checklist" of Richwald. Rhodes, and Kersey and an in-person interview that
queried their reasons for obtaining different levels of prenatal care. RESULTS:
Both personal and structural reasons were described by women for not obtaining
care earlier in pregnancy or at all. The mean number of personal and structural
problems reported per subject was inversely correlated to the level of prenatal
care obtained. However, personal problems were the single most important reason
cited by these women. Personal problems that were statistically significant
different among the groups were drug use and desire for an abortion. The
structural barriers that exhibited statistically significant differences among
the groups were trouble scheduling an appointment, access totransportation,
dislike of health care professionals and institutions, access to child care, and
not knowing where to go. CONCLUSION: Both personal and structural problems were
cited as reasons for not obtaining adequate prenatal care. Structural barriers to
prenatal care have been identified and extensively studied. These barriers to
care continue to persist, despite innovations in program delivery and access.
This study demonstrates that the significance of personal problems has not been
adequately considered as a major factor associated with insufficient prenatal
care.
PMID- 10685204
TI - Disseminated coagulopathy associated with transtorcular embolization of vein of
Galen aneurysm in a neonate.
AB - We describe in this report the development of disseminated intravascular
coagulopathy in a neonate after transtorcular embolization of an unusual vein of
Galen aneurysm. This rare but potentially fatal complication associated with
transtorcular embolization should be considered in decision-making and prognostic
evaluation processes, especially in neonates with severe heart failure.
PMID- 10685205
TI - Persistent pulmonary hypertension in a neonate with cystic adenomatoid
malformation of the lung following lobectomy: survival with prolonged
extracorporeal membrane oxygenation therapy.
AB - A full-term neonate is reported with congenital cystic adenomatoid malformation
of the lung treated by lobectomy with development of pulmonary hypertension. The
infant was successfully treated with extracorporeal membrane oxygenation (ECMO)
for persistent pulmonary hypertension, which developed postoperatively. An 18-day
course of venovenous ECMO was necessary to effectively reverse the severe
pulmonary hypertension. This was probably a result of significant pulmonary
hypoplasia of the compressed lung. Although not all congenital cystic adenomatoid
malformations of the lung are associated with pulmonary hypoplasia and persistent
pulmonary hypertension, this is one case where severe pulmonary hypertension
developed secondary to a mass effect by a large lesion in the chest.
PMID- 10685206
TI - Congenital chylothorax in neonatal thyrotoxicosis.
AB - We report a patient with congenital chylothorax who also had neonatal
thyrotoxicosis secondary to maternal Graves' disease. Fetal tachycardia with
hydrops was detected at 28 weeks' gestational age. The fetus responded to
antithyroid medication in utero but had persistent bilateral pleural effusion. At
birth, he had respiratory distress due to massive pleural effusion. Cytologic
studies of pleural fluid were consistent with chylothorax. To the best of our
knowledge, the association of congenital chylothorax with fetal (neonatal)
thyrotoxicosis, has not been reported previously.
PMID- 10685207
TI - Genetics casebook. Pyloric atresia.
PMID- 10685208
TI - Special imaging casebook. Neonatal Bardet-Biedl syndrome with renal anomalies and
hydrocolpos with vesicovaginal fistula.
PMID- 10685209
TI - Neonatal apnea casebook. Gastroesophageal reflux (GER)-associated apnea.
PMID- 10685211
TI - Sedation administered to very low birth weight premature infants
PMID- 10685210
TI - Developmentally based care reduces stress levels in severely ill, very low birth
weight (VLBW) infants, and thus decreases sedation requirements.
PMID- 10685212
TI - Joe Butterfield's panache.
PMID- 10685213
TI - An open letter to the Butterfields.
PMID- 10685214
TI - L. Joseph Butterfield, MD: a man for all seasons.
PMID- 10685215
TI - L. Joseph Butterfield, MD: personal reflections.
PMID- 10685216
TI - Newborn country, USA.
PMID- 10685217
TI - Reflections about a friend.
PMID- 10685218
TI - In honor of Dr. Joseph Butterfield.
PMID- 10685219
TI - Personal reflection on Joe Butterfield.
PMID- 10685220
TI - The good doctor: a neonatologist's perspective.
PMID- 10685221
TI - Parental dreams, dilemmas, and decision-making in cinema verite.
AB - Our film Dreams and Dilemmas: Parents and the Practice of Neonatal Care is on its
way to meeting its goal of furthering the "Principles for Family Centered
Neonatal Care" (Harrison H. Pediatrics 1993;92:643-50) through cinema verite
depiction of parental involvement in decision-making. Reality-based filmmaking
can provide valuable and successful educational material that advances care and
understanding. However, there are real practical and ethical concerns such as
privacy, consent, and uncertain or unknown future impact on participants.
Successful reality-based filmmaking in a complex medical environment such as a
neonatal intensive care unit requires careful attention to ways of ensuring full
communication between all those involved and efforts to allay participants'
anxiety about being portrayed unfavorably. The most important ingredient,
however, is the skill and ability of the filmmaker to engender trust.
PMID- 10685222
TI - Very low birth weight births at non-NICU hospitals: the role of sociodemographic,
perinatal, and geographic factors.
AB - PURPOSE: The purpose of this study was to assess the extent of variation in the
percentage of very low birth weight (VLBW) infants born at perinatal Level 1
hospitals (no Neonatal Intensive Care Unit [NICU]) across California's nine
geographic Perinatal regions. The role of sociodemographic, perinatal, and
geographic factors was also assessed. METHODS: Multivariate analysis of
California birth certificate files between 1989 and 1993, for 24,094 live-born
infants weighing between 500 and 1499 gm, was conducted to identify factors
associated with delivery at a Level 1 hospital. Analyses specific for race and
ethnicity were also conducted for Hispanic, African American, and white cohorts.
RESULTS: In the 5-year study period, 1989 through 1993, 10.5% (24,094) of all
live-born VLBW infants were delivered in Level 1 hospitals. Significant variation
across regions was evident, ranging from a regional low of 3.1% to a high of
24.3%. After controlling for multiple factors, the odds of delivering at a Level
1 hospital were decreased for African Americans and South East Asians and
increased in Hispanic women as compared with white non-Hispanic women. For all
women, less then adequate prenatal care, living in a 50% to 75% urban zip code,
and living greater then 25 miles from the nearest NICU significantly increased
the odds of VLBW delivery at a Level 1 hospital. For Hispanics, teen pregnancy
and having two or more prior infant deaths increased the odds, whereas Medi-Cal
as the payer source for delivery and two or more pregnancy complications
decreased the odds of a Level 1 VLBW delivery. After taking these factors into
account, when compared with Los Angeles, the odds of inappropriate delivery site
ranged from 0.37 to 2.75 across California's nine geographic perinatal regions.
Of this variation, 78% could be accounted for by the percentage of total births
that delivered at a region's Level 1 hospitals. CONCLUSION: The overall state
average of 10.5% deliveries of VLBW at Level 1 hospitals, although close to the
10% national objective for the year 2000, did not indicate the wide variation
seen across California's nine geographic regions. Risk-adjusted regional
differences in the likelihood of inappropriate delivery site for the high-risk
VLBW infants suggest that reaching the Healthy People 2000 objective will require
further strengthening of California's perinatal regional networks, especially in
those regions where a high percentage of total births deliver at Level 1
hospitals.
PMID- 10685223
TI - Bilirubin toxicity and differentiation of cultured astrocytes.
AB - OBJECTIVE: To study the toxicity of bilirubin in primary cultures of newborn rat
cerebral cortical astrocytes. STUDY DESIGN: Primary cultures of newborn rat
astrocytes were incubated at bilirubin concentrations of 0, 1, 5, 10, 25, 50,
100, 200, and 2000 microM, at a bilirubin:albumin molar ratio of 1.7. Bilirubin
toxicity was determined by changes in cellular morphology, trypan blue staining,
and lactate dehydrogenase (LDH) release into the culture medium at various times
of incubation. To determine if differentiation of astrocytes affects bilirubin
toxicity, cultures were treated with dibutyryl cyclic adenosine monophosphate.
RESULTS: All three indices of toxicity showed a bilirubin concentration
dependence. LDH release in experimental cultures was significantly elevated (p <
0.05) above that of control cultures by 24 hours at bilirubin concentrations of >
or = 100 microM. The absolute amount of LDH release differed significantly
between the 200 and 2000 microM cultures from 1.5 to 24 hours, after which
duration of exposure appeared to take over and all cultures approached maximum.
LDH release for the lower concentrations all reached maximum by 120 hours, except
for the 1 microM cultures, which showed no significant elevation above control
throughout the study period. At 100 and 200 microM bilirubin, LDH release by
untreated cells was significantly higher (p < 0.05) than release by treated cells
by 36 hours. CONCLUSION: Undifferentiated astrocytes appeared to be more
sensitive to bilirubin toxicity, which may correlate with the greater
susceptibility of newborns to kernicteric injury. Studies with primary astrocyte
culture may provide insight into how bilirubin sensitivity changes with brain
development as well as the cellular and biochemical mechanisms of bilirubin
encephalopathy.
PMID- 10685224
TI - Outcomes and resource utilization for newborns with major congenital
malformations: the initial NICU admission.
AB - HYPOTHESIS: Newborns with major congenital malformations (MCM) have contributed
to a significant proportion of resource utilization in a regional referral
neonatal intensive care unit (NICU). SETTING: The Children's Hospital Medical
Center NICU, Cincinnati, OH. SUBJECTS: Newborns with and without MCM admitted
from August 1, 1993 through July 31, 1994. Total patients studied were 572; 147
with and 385 without MCM. No intervention was performed in this observational
study. STATISTICS: Statistics were t test, chi-squared, and rank sum analysis.
RESULTS: MCM accounted for 27.6% of NICU referrals, 32.4% of total NICU days, and
39.6% of NICU costs. Both median cost per patient and length of stay were
significantly (p < 0.01) higher for patients with MCM than those without MCM.
Surgery was more frequent in MCM than non-MCM cases. Thirty-three percent of the
newborns with MCM received ongoing medical support at discharge. CONCLUSION:
Patients with MCM remain as one of the largest and costliest groups hospitalized
in a referral NICU.
PMID- 10685225
TI - Obesity and related pregnancy complications in an inner-city clinic.
AB - OBJECTIVE: The study was designed to determine the prevalence of obesity and
related pregnancy complications in an inner-city prenatal clinic. STUDY DESIGN: A
retrospective review was conducted of the medical records of 281 women with no
chronic diseases and who delivered singleton term babies during a 1-year period.
The frequencies of various pregnancy complications, including pregnancy-induced
hypertension, preeclampsia, gestational diabetes, shoulder dystocia, postpartum
hemorrhage, fourth degree laceration, intrauterine growth restriction, and
macrosomia, were compared among groups of patients stratified by body mass index
(BMI). RESULTS: Thirty-four percent of patients had a reported prepregnancy BMI
of > 26 kg/m2. Fifty-two percent of patients were obese (BMI > 26 kg/m2) when
they registered for prenatal care, and 82% of patients had a BMI > 26 kg/m2 at
the time of delivery. The incidence of birth weights of > 4 kg was significantly
higher in women with a registration BMI > 26 kg/m2 (p = 0.026). Most of these
macrosomic babies had mothers with a BMI > 29 kg/m2. Patients who required
cesarean delivery had significantly higher BMI than those who were delivered
vaginally (p < 0.001). CONCLUSION: Obesity was more common in our inner-city
population than has previously been reported and was associated with an increased
risk of fetal macrosomia and operative delivery.
PMID- 10685226
TI - Pulmonary hypertension in children following extracorporeal membrane oxygenation
therapy and repair of congenital diaphragmatic hernia.
AB - OBJECTIVE: Pulmonary hypertension (PHT) is present in all children at birth, but
its degree and rate of resolution in infants diagnosed with congenital
diaphragmatic hernia (CDH) requiring extracorporeal membrane oxygenation (ECMO)
need to be established. STUDY DESIGN: Twenty-one ECMO/CDH survivors (aged 3.2 +/-
1.4 years) were prospectively evaluated by Doppler echocardiography (ECHO) to
determine the presence of PHT. Twenty children without structural heart disease
were used as controls. Study patients received a physical examination and an
electrocardiograph examination, and their charts were reviewed for neonatal
course data. Patients found to have PHT by ECHO received a complete history and
exercise treadmill/oxygen desaturation study. RESULTS: Eight of the 21 patients
(38%) met echocardiographic criteria for PHT. No neonatal course data were found
to be predictive of eventual PHT status. There was no correlation between
physical examination or electrocardiographic findings and PHT. Complete histories
showed five of the eight patients with PHT had some degree of exercise
intolerance and seven had wheezing. Two of the seven patients studied on the
treadmill desaturated 5% or greater from baseline. CONCLUSION: There is evidence
that PHT either persists or recurs in a significant portion of the ECMO/CDH
population and may remain symptomatic well beyond the neonatal period.
PMID- 10685227
TI - Massive fetomaternal hemorrhage and fetal death: are they predictable?
AB - OBJECTIVE: To report the incidence of massive fetomaternal hemorrhage (FMH)
associated with fetal death and to test the hypothesis that FMH is more likely to
occur in those with risk factors for FMH. STUDY DESIGN: All cases of fetal death
of infants weighing > 500 gm between January 1, 1990 and December 31, 1994 were
reviewed for evidence of massive FMH (> or = 2% fetal cells in the maternal
circulation as measured by the Betke-Kleihauer test). Women with risk factors
were compared with those without risk factors with respect to the occurrence of
massive FMH. RESULTS: The prevalence of massive FMH was 14 of 319 (4.4%) cases,
occurring in 4 of 102 (3.9%) of those with risk factors and 10 of 217 (4.6%) of
patients without risk factors (p = 0.78). Otherwise unexplained fetal death was
associated with massive FMH in 5 of 141 (3.5%). Major fetal anomalies were
present in 5 of 14 (35.7%) cases of massive FMH. CONCLUSION: Clinical risk
factors do not predict an increased likelihood of massive FMH. Massive FMH is
associated with fetal anomalies. Betke-Kleihauer testing should be performed in
all cases of fetal death, including those with anomalies regardless of the
presence or absence of risk factors for FMH.
PMID- 10685228
TI - Chemotherapy during pregnancy and its effects on the fetus--neonatal
myelosuppression: two case reports.
AB - Cancer during pregnancy is infrequent. It presents an ethical dilemma--remission
may be obtained with chemotherapy, but it has potential harmful effects to the
fetus. We report a case of a very low birth weight preterm female infant born to
a 21-year-old mother diagnosed with leukemia and given chemotherapy up to 1 week
before delivery. In the laboratory, initial findings included severe
pancytopenia, and bone marrow aspiration demonstrated complete aplasia. She was
given blood product transfusions, erythropoietin, and granulocyte colony
stimulating factor. The hematologic derangement was resolved without documented
infections. The second case is a preterm male infant whose 30-year-old mother was
diagnosed with lymphoma and had received chemotherapy during the third trimester.
The infant presented with moderate leukopenia. He had an uneventful course
without documented infection. Exposure of the fetus to transplacental
chemotherapy must be considered when evaluating therapy options and timing of
delivery in hematologic malignancies diagnosed during pregnancy.
PMID- 10685229
TI - Resuscitation of the meconium-stained infant and prevention of meconium
aspiration syndrome.
PMID- 10685230
TI - Radiology casebook. Gastric perforation with subserosal dissection of air.
PMID- 10685231
TI - Asymptomatic intraplacental choriocarcinoma diagnosed on routine placental
examination.
AB - Asymptomatic intraplacental choriocarcinoma is a rare event with only a few case
reports in the literature. The recognition of such a lesion on routine placental
examination is important and prompts rapid clinical evaluation for identifying
residual and/or metastatic disease followed by institution of chemotherapy.
Failure to recognize such a lesion on gross inspection of the placenta can result
in disseminated disease, which can be lethal. The following report describes the
placental findings and clinical outcome in a recent case with a review of the
relevant literature.
PMID- 10685232
TI - The California Perinatal Quality Care Collaborative: a model for national
perinatal care.
PMID- 10685233
TI - Percutaneous central catheters and peripheral intravenous catheters have similar
infection rates in very low birth weight infants.
AB - OBJECTIVE: We performed this study to determine if percutaneous central lines
(PCLs) were associated with infection more often than peripherally placed
intravenous catheters (PIVs). STUDY DESIGN: We conducted a retrospective, cohort
study of 53 infants with PCLs inserted from March 1993 to February 1995 for
evidence of catheter-related bloodstream infection and 97 cohorts with PIVs who
were matched to the infants with PCLs by admission date and birth weight. We
considered an infant to have catheter-related bloodstream infection if bacteremia
occurred while the PCL or PIV was in place with no other identifiable infection
focus. Statistical analyses were performed by using either Student's t test or
the Mann-Whitney U test where appropriate. RESULTS: There were eight infections
per 1000 catheter days of PCL use and nine infections per 1000 catheter days of
PIV use. CONCLUSION: PCLs do not become infected more often than PIVs.
PMID- 10685234
TI - Fetal erythropoietin levels in growth-restricted and appropriately grown neonates
with and without abnormal fetal heart rate tracings: a comparison with cord blood
gases and Apgar scores.
AB - OBJECTIVE: To determine if umbilical cord plasma erythropoietin (EPO) levels in
combination with cord blood gases and Apgar scores can distinguish between
subacute and chronic uteroplacental insufficiency. METHODS: A total of 184
neonates delivered between 1993 and 1997 at Tampa General Hospital were studied.
Cord plasma EPO levels, cord blood gases, and Apgar scores were determined
prospectively and compared in four subgroups that were defined based on the
presence or absence of fetal growth restriction (FGR; chronic fetal hypoxia),
abnormal fetal heart rate tracings during labor (FHR; subacute/acute fetal
hypoxia), or both. RESULTS: Both growth-restricted and appropriately grown
newborns with abnormal intrapartum FHR tracing had elevated umbilical cord plasma
EPO (183.5 and 135.2 mIU/ml, respectively; normal = 20.7 mIU/ml) and base
deficit, whereas pH, Po2, and 1-minute and 5-minute Apgar scores were
significantly lower, compared with appropriately grown newborns with a normal
intrapartum course. Among newborns with normal heart rate tracings and FGR, the
mean plasma EPO levels were elevated (89.5 mIU/ml), whereas the other parameters
were not different from normal. CONCLUSION: Our findings suggest that, although
cord blood gases and Apgar scores may reflect subacute and acute events, they are
not good predictors of chronic uteroplacental insufficiency. The supplemental use
of umbilical cord plasma EPO levels may improve our ability to identify chronic
uteroplacental insufficiency.
PMID- 10685235
TI - Release of superoxide dismutase activity from human umbilical veins by heparin.
AB - OBJECTIVE: This study evaluated superoxide dismutase activity released from human
umbilical veins incubated with different doses of heparin and examined at
different time points. STUDY DESIGN: Umbilical veins of fresh cords from full
term babies were incubated with 175 or 1 U/ml of heparin at one end while the
other end was incubated without heparin as control. Specimens were obtained at 10
minutes and 24 hours (high-dose) or at 10 minutes and 60 minutes (low-dose).
Superoxide dismutase activity was measured by the cytochrome c method. Results
were analyzed using Student's paired t test. RESULTS: A time-dependent release of
superoxide dismutase activity into the buffer was observed in both heparin
specimens as well as in control specimens. The difference in release in the
presence of heparin was of statistical significance, compared with the controls.
CONCLUSION: Because heparin is routinely used as an anticoagulant to maintain the
patency of umbilical catheters, we conclude that this usage may alter a newborn's
response to oxygen free radical damage by changes in superoxide dismutase
activity.
PMID- 10685236
TI - Preterm infant thermal care: differing thermal environments produced by air
versus skin servo-control incubators.
AB - OBJECTIVE: Incubator thermal environments produced by skin versus air servo
control were compared. STUDY DESIGN: Infant abdominal skin and incubator air
temperatures were recorded from 18 infants in skin servo-control and 14 infants
in air servo-control (26- to 29-week gestational age, 14 +/- 2 days postnatal
age) for 24 hours. Differences in incubator and infant temperature, neutral
thermal environment (NTE) maintenance, and infant and incubator circadian rhythm
were examined using analysis of variance and scatterplots. RESULTS: Skin servo
control resulted in more variable air temperature, yet more stable infant
temperature, and more time within the NTE. Circadian rhythm of both infant and
incubator temperature differed by control mode and the relationship between
incubator and infant temperature rhythms was a function of control mode.
CONCLUSION: The differences between incubator control modes extend beyond
temperature stability and maintenance of NTE. Circadian rhythm of incubator and
infant temperatures is influenced by incubator control.
PMID- 10685237
TI - Phototherapy increases hemoglobin degradation and bilirubin production in preterm
infants.
AB - OBJECTIVE: To compare hemoglobin degradation and bilirubin production before and
during phototherapy in preterm infants. BACKGROUND: Hemoglobin is catabolized
into globin and heme, which is degraded by microsomal heme oxygenase into
equimolar carbon monoxide and biliverdin. Biliverdin is then reduced into
bilirubin. CO is excreted exclusively by the lungs; therefore, end-tidal carbon
monoxide, corrected for inhaled CO (ETCOc), reflects hemoglobin degradation and
total bilirubin production. METHOD: A prospective study design was used,
including a study group of 24 preterm infants requiring phototherapy. Infants
with hemolytic diseases, sepsis, recent blood transfusion, and infants on
mechanical ventilation were excluded. ETCOc was measured in preterm infants
before and during phototherapy. Hemoglobin degradation and bilirubin production
were calculated by measuring ETCOc. RESULTS: The (mean +/- SD) birth weight of 24
preterm neonates was 1975 +/- 613 gm, gestational age was 32.7 +/- 2.3 weeks,
hematocrit was 47.5 +/- 6.2 volume%, and peak bilirubin was 13.1 +/- 3.2 mg/dl.
First ETCOc measurements were done at 59.6 +/- 22.2 hours of age immediately
before starting phototherapy. The second ETCOc measurements were taken at 13.7 +/
7.9 hours after starting phototherapy. The second measurement of 2.6 +/- 0.6 ppm
(mean +/- SD) was significantly higher than the first ETCOc of 2.1 +/- 0.6 ppm (p
< 0.05). CONCLUSION: Phototherapy increases hemoglobin degradation and bilirubin
production in preterm infants.
PMID- 10685238
TI - Ureaplasma/Mycoplasma-infected amniotic fluid: pregnancy outcome in treated and
nontreated patients.
AB - OBJECTIVE: To determine if treatment of a positive amniotic fluid culture for
mycoplasmal colonization obtained at genetic amniocentesis is associated with
improved pregnancy outcome. STUDY DESIGN: A retrospective analysis of 2718
genetic amniocentesis specimens cultured for Ureaplasma/Mycoplasma was
undertaken. Specimens were obtained between March 1993 and January 1997. The
Irvine culture kit was used to culture all specimens. Data collected included
indication for amniocentesis, gestational age at amniocentesis, karyotype,
gestational age at delivery, pregnancy outcome, and any antimicrobial treatment.
RESULTS: During this time period 44 patients were found to be culture-positive
for Ureaplasma/Mycoplasma. Thirty-five were treated with oral erythromycin. Mid
trimester loss was 11.4% and 44.4% (p = 0.04) in the treated and untreated
groups, respectively. Preterm delivery was similar in the two groups, 19.4% and
20% (p = NS). CONCLUSION: Treatment of an amniotic mycoplasmal colonization with
erythromycin was associated with fewer mid-trimester losses after genetic
amniocentesis. Preterm delivery rates between the two groups were similar, which
may indicate recolonization.
PMID- 10685239
TI - The effect of application of aquaphor on skin condition, fluid requirements, and
bacterial colonization in very low birth weight infants.
AB - OBJECTIVE: To determine the effects of repeated application of an occlusive
ointment on the skin of very low birth weight infants. STUDY DESIGN: Nineteen
neonates of 26 to 30 weeks gestational age were randomly assigned to receive
topical Aquaphor ointment twice daily for 2 weeks or to receive standard skin
care. Skin quality, fluid requirements, and skin bacterial colonization counts
were assessed. RESULTS: Infants treated with Aquaphor had significantly improved
skin condition scores versus controls (p = 0.002). Aquaphor improved skin scores
over time (p = 0.012) in treated infants, whereas skin scores of untreated
infants worsened before eventually healing. There were no significant differences
in total fluid requirements, urine output, serum sodium concentrations, skin
bacterial counts, fungal counts, or colonization patterns between treated and
control infants in either gestational age cohort. CONCLUSION: Aquaphor ointment,
used during the first two postnatal weeks, improved skin condition in infants of
26 to 30 weeks' gestation without changing skin bacterial flora. We speculate
that improved skin condition may limit transepidermal water loss and decrease
portals of entry for pathogens, thereby potentially decreasing fluid and
electrolyte imbalances and sepsis in very low birth weight infants.
PMID- 10685240
TI - Predictors of development in premature infants from low-income families: African
Americans and Hispanics.
AB - OBJECTIVE: The goal of the study was to determine the factors that affect the
motor and mental development of premature Latino and African American infants
from low socioeconomic backgrounds. STUDY DESIGN: A prospective study of 41 low
birth weight (LBW) African American infants along with 82 LBW Hispanic infants
examined the factors that influence mental and motor development at 8 months of
age. Multiple regression analysis was performed to correlate perinatal,
environmental, and demographic variables with mental and motor development using
the Bayley scales of infant development. The perinatal variables included birth
weight, gestational age, and days of hospitalization. The demographic and
environmental variables chosen were: income, education, the home environment,
social support, mother-infant interaction, and maternal confidence. RESULTS: The
results indicated that, for African American infants, motor development was
correlated with the mother's education and the number of days the infant spent in
the hospital Mental development for African American infants was predicted by the
home environment. For Hispanic infants, the home environment predicted motor
scores while the mother-infant interaction was correlated with the mental scores.
CONCLUSION: Factors contributing to the development of premature infants vary
according to ethnicity, and social variables may be more predictive of
development than medical factors.
PMID- 10685241
TI - Comparison of DNA probe technology and automated continuous-monitoring blood
culture systems in the detection of neonatal bacteremia.
AB - OBJECTIVE: The present study assessed the ability of a rapid chemiluminescent DNA
probe assay to detect bacterial growth in blood culture specimens before their
detection by continuous-monitoring blood culture (CMBC) systems. STUDY DESIGN:
Three newborn intensive care units, which are members of the National Institute
of Child Health and Human Development Neonatal Research Network, participated in
this study. Each center employs an automated CMBC system against which the DNA
probe was compared. A total of 1700 blood cultures were analyzed. A 3-ml aliquot
of culture medium was removed from each culture during early incubation,
processed, and analyzed by the DNA probe. RESULTS: Of 1700 blood cultures, 130
(7.6%) were detected positive by a CMBC system. Coagulase-negative staphylococci
(CNS) were present in 90 (69%) of the positive cultures, and 26 (29%) were
detected by the DNA probe. Other organisms accounted for the remaining 40
positive cultures, and 31 (78%) of these were detected by the probe assay.
Seventy-six percent of all positive cultures were detected by a CMBC system
within 24 hours. Ninety-eight percent of all positive cultures were detected by a
CMBC system within 48 hours. Of the two organisms that grew in a CMBC system
beyond 48 hours, both were CNS and one of these was considered a contaminant.
Therefore, 99% of clinically significant organisms were detected by a CMBC system
within 48 hours. CONCLUSION: This DNA probe is not sufficiently sensitive to be
clinically useful; however, automated CMBC systems are sufficiently sensitive to
aid in clinical decision-making regarding the continuance or discontinuance of
antibiotic therapy following 48 hours of culture incubation.
PMID- 10685242
TI - Sudden deterioration of the newborn infant: II. Diagnosis-based approach in the
intensive care unit.
PMID- 10685243
TI - Balloon dilatation of the pulmonary valve in a 690-gm neonate with tetralogy of
Fallot.
PMID- 10685244
TI - Ignac Semmelweis and the etiology of fetal and neonatal sepsis.
AB - It is well-known that Ignac Semmelweis discovered the etiology and prophylaxis of
puerperal sepsis. However, few historians have focused on his understanding of
the pathophysiology of fetal and neonatal sepsis. Based on several key
observations, Semmelweis realized that puerperal fever (also known as "childbed
fever") could be transmitted to the fetus, especially when the first stage of
labor was prolonged and multiple examiners performed vaginal examinations while
their fingers were contaminated. This insight was particularly valuable in that
it helped him decipher the mystery of puerperal sepsis. This paper presents some
of these concepts and supporting evidence.
PMID- 10685245
TI - Successful treatment of late-onset infection due to resistant Klebsiella
pneumoniae in an extremely low birth weight infant using ciprofloxacin.
AB - OBJECTIVE: This paper presents a case in which an extremely low birth weight
infant with multidrug-resistant Klebsiella pneumoniae infection was successfully
treated with ciprofloxacin and gentamicin. STUDY DESIGN: A clinical case report
of a neonate who received broad spectrum antibiotics for possible infection
despite negative cultures. The infant developed sepsis and meningitis resulting
from multidrug-resistant K. pneumoniae, which was treated with ciprofloxacin and
gentamicin. The literature for the use of ciprofloxacin in pediatric patients was
reviewed. RESULTS: The infant responded to the antibiotic regimen with
sterilization of blood and cerebrospinal fluid; no adverse effects were
attributable to the ciprofloxacin. Although ciprofloxacin has been found to cause
irreversible injury to cartilage in juvenile laboratory animals, a review of the
literature found that this complication occurs rarely if at all in pediatric
patients. Ciprofloxacin has been found to be effective in the treatment of
multidrug-resistant Gram-negative infections in pediatric patients, including
premature infants. CONCLUSION: Ciprofloxacin should be considered in the
treatment of neonatal infection caused by multidrug-resistant Gram-negative
organisms. Although the published experience with this drug suggests that it is
effective and that significant toxicity is not common, its use should be
restricted to the treatment of serious infections for which an alternative
antibiotics is not available.
PMID- 10685246
TI - Haemophilus parainfluenzae sepsis in a very low birth weight premature infant: a
case report and review of the literature.
AB - Haemophilus parainfluenzae is an unusual cause of invasive bacterial disease and
is particularly uncommon as a reported etiology of neonatal sepsis in current
large published series. We describe a seriously ill, very low birth weight (VLBW)
infant with documented early onset sepsis caused by H. parainfluenzae. We compare
our case with those published previously and contrast the clinical presentation
of infection in our patient to that of common bacterial pathogens causing
neonatal sepsis. Our review suggests many common factors in the pathogenesis of
early onset infection by H. parainfluenzae.
PMID- 10685247
TI - Testicular torsion in a pre-term neonate.
PMID- 10685248
TI - Ventilatory management casebook: recurrent diaphragmatic hernia.
PMID- 10685249
TI - Special imaging casebook. Congenital neuroblastoma and cyanotic heart disease.
PMID- 10685251
TI - Challenges for neonatology and neonatologists.
PMID- 10685250
TI - Necrotizing funisitis with intrapartum umbilical cord rupture.
PMID- 10685252
TI - Ultrasonographic differential diagnosis and neurodevelopmental outcome of
cerebral white matter lesions in premature infants.
AB - OBJECTIVE: To determine the clinical usefulness of recently published
ultrasonographic criteria for the differential diagnosis of periventricular
hemorrhagic venous infarction (PHVI) versus periventricular leukomalacia (PVL),
and its relevance to neurodevelopmental outcome. STUDY DESIGN: From 1992 to 1995,
we evaluated 998 very low birth weight infants of which 111 developed cerebral
white matter lesions on cranial ultrasonogram examination. An attempt was made to
differentiate the lesions into either PHVI or PVL using specific ultrasonographic
criteria (Volpe JJ. Brain inury in the premature infant: is it preventable?
Pediatr Res 1990; 6:S28-33). Seventy-six patients who survived to discharge
constituted the study group. Survivors were followed prospectively with
neurologic examinations, visual and auditory screening, and developmental
testing. RESULTS: PHVI was diagnosed in 23 patients (30%), PVL in 36 (47%),
characteristics of both PHVI and PVL (mixed lesions) in 8 (11%), and persistent
periventricular echodensity without cystic change in 9 (12%). Two-year follow-up
data were obtained on 57 of 76 (75%) patients. Neurodevelopmental deficits were
common in all groups; however, infants with localized PHVI had a mean
developmental quotient in the normal range. CONCLUSION: The majority of white
matter lesions (77%) can be differentiated as either PHVI or PVL by
ultrasonographic criteria, with coexisting features in only 11% of patients. In
addition to these lesions, persistent periventricular echodensity was also
associated with a high risk of subsequent neurodevelopmental deficit. However,
normal development was seen in a subgroup of patients with localized
periventricular hemorrhagic venous infarction.
PMID- 10685253
TI - Group B streptococcus: to culture or not to culture?
AB - OBJECTIVE: To determine if universal Group B Streptococcus (GBS) culturing and
antibiotic prophylaxis of obstetric patients decreased the incidence of neonatal
early-onset GBS sepsis and mortality and maternal chorioamnionitis. STUDY DESIGN:
A time series observational study was conducted to compare the cohort of all
obstetric patients delivering at the University of Chicago neonatal center from
January 1989 through December 1993, before a GBS surveillance policy existed,
with the cohort delivering January 1994 through December 1996, after initiation
of a GBS policy. Included in the policy were universal GBS cultures at 28 weeks'
gestation, antibiotic prophylaxis at the time of labor for all those with
positive cultures and for all with risk factors of preterm delivery, preterm
premature rupture of membranes, prolonged rupture of membranes greater than 18
hours, and a previous child affected by GBS or maternal fever in labor. Predictor
variables were GBS culturing and antibiotic usage; outcome variables were
incidence of GBS sepsis and mortality in the neonates and maternal
chorioamnionitis. chi-squared and Fisher exact analyses were used with p < 0.05
being significant. RESULTS: Before the GBS policy, there were 16,272 deliveries
with a 2.24/1000 deliveries rate of early-onset GBS sepsis (n = 35); after
initiating the GBS policy, 9130 deliveries occurred with an early-onset GBS
sepsis rate of 2.29/1000 (n = 20). Early-onset GBS sepsis case fatality rates
before and after initiation of the policy were 14.3% and 0%, respectively (p =
0.09). Antibiotic use almost doubled (relative risk = 1.84; confidence interval,
1.74 to 1.93, p < 0.001) over the two time periods, and the relative risk of
chorioamnionitis decreased to 0.95 (confidence interval, 0.73 to 0.99, p = 0.04).
CONCLUSION: Despite universal GBS culturing and very liberal use of antibiotics
in labor, we were unable to effect a statistically significant change in the rate
of early-onset GBS sepsis or mortality, and there was only a slightly decreased
chorioamnionitis rate.
PMID- 10685254
TI - Creamatocrit and the nutrient composition of human milk.
AB - OBJECTIVE: We tested the hypothesis that creamatocrit, the length of the cream
column separated from milk by centrifugation and expressed as a percentage of the
length of the total milk column, is a useful measure of the lipid concentration
and the energy content of human milk. STUDY DESIGN: Milk samples from 17 mothers
of preterm infants were analyzed prospectively, fresh as well as frozen and
thawed, for creamatocrit measurement and nutrient composition. RESULTS:
Creamatocrit correlated strongly with lipid concentration and energy content of
human milk, fresh or frozen and thawed. The energy content can be calculated from
the regression equation: Energy (kcal/dl) = 5.99 x creamatocrit(%) + 32.5 for a
fresh sample, and energy (kcal/dl) = 6.20 x creamatocrit(%) + 35.1 for a frozen
sample. CONCLUSION: Calculations of energy content from the creamatocrit
measurement may be useful for an accurate assessment of energy intake in preterm
infants fed human milk.
PMID- 10685255
TI - Effect of dexamethasone on lymphocyte subpopulations in premature infants with
bronchopulmonary dysplasia.
AB - OBJECTIVE: This study was designed to determine the effect of dexamethasone
treatment on peripheral blood lymphocyte counts and subpopulations in premature
infants with bronchopulmonary dysplasia (BPD). STUDY DESIGN: Peripheral blood
lymphocyte subpopulations in 12 premature infants with BPD were analyzed before
treatment with a 6-week course of dexamethasone (day 0), on days 3 and 10 of
treatment, and 2 weeks after discontinuing dexamethasone therapy (day 56).
Lymphocyte immunophenotypes were determined using direct two-color
immunofluorescent staining followed by flow cytometry. RESULTS: The percentage of
lymphocytes was significantly lower on days 3 (17.55 +/- 2.55) and 10 (20 +/-
11.8) of dexamethasone therapy compared with before (30.36 +/- 6.41) or after
treatment. The percentage of T cells was significantly lower on days 3 and 10 of
dexamethasone therapy (mean +/- SEM; 58.09 +/- 1.93 and 60.09 +/- 2.47,
respectively) compared with before (67.09 +/- 4.24) or after treatment. The
absolute number of T cells was significantly lower on day 10 of therapy. The
percentage of CD4+ cells was significantly lower on days 3 (38.91 +/- 2.49) and
10 (40.45 +/- 2.24) of therapy, and this decrease persisted after dexamethasone
was stopped (36.73 +/- 3.41). The absolute number of CD4 cells was significantly
lower on day 10 (1328 +/- 216) of therapy and reached a nadir on day 56 (1143 +/-
106). Similarly, the CD4/CD8 ratio was also significantly lower on days 3 and 10
of treatment (1.56 +/- 0.18 and 1.64 +/- 0.14, respectively) and reached a nadir
on day 56 (1.04 +/- 0.13). CONCLUSION: Dexamethasone significantly reduced the
percentage and absolute number of lymphocytes, T cells, and CD4 cells, as well as
the CD4/CD8 ratio. A reduction in CD4 cells and in the CD4/CD8 ratio persisted 2
weeks after dexamethasone therapy was stopped. In contrast, the absolute number
of B cells increased transiently, and CD8 cells were unaffected by dexamethasone.
This alteration in lymphocyte subpopulations may help account for the clinically
beneficial anti-inflammatory effect of dexamethasone in the treatment of BPD
complicated by respiratory failure. The dexamethasone-induced decrease in CD4
cells may also increase the susceptibility of these infants to infection.
PMID- 10685256
TI - Low serum cortisol in term newborns with refractory hypotension.
AB - OBJECTIVES: The aim of this study is to measure baseline serum cortisol levels
and clinical response to glucocorticoid therapy in a group of term infants with
refractory hypotension. STUDY DESIGN: Seven term newborns with refractory
hypotension were included. Serum cortisol levels were drawn before initiation of
glucocorticoid therapy and measured by either fluorescence polarization
immunoassay or radioimmunoassay. Baseline blood pressures, heart rate, and
inotropes doses were recorded at baseline, then 4, 8, 12, 24, 48, 72, and 96
hours after glucocorticoid therapy. Urine output and volume expanders the infants
received were recorded 24 hours before and after glucocorticoid therapy.
Dexamethasone was used at a starting dose of 0.2 mg/kg per day divided every 12
hours. The statistical analysis was done using analysis of variance with repeated
measures and paired t-test. RESULTS: Serum cortisol levels of the infants ranged
from 2.0 to 15.4 micrograms/dl. After initiation of glucocorticoid therapy, there
was significant improvement of blood pressure. Vasopressors were rapidly weaned
and discontinued within 72 hours. In three of seven infants, no volume expanders
were required after initiation of steroids, and none needed volume expanders
after 2 days. Urine output increased significantly within 24 hours. All infants
survived. CONCLUSIONS: Glucocorticoids improved pressure and stabilized clinical
conditions of a group of term newborns with refractory hypotension. Serum
cortisol levels of these infants were relatively low. We speculate that a subset
of critically ill term infants has relative adrenal insufficiency and
glucocorticoid therapy may be essential.
PMID- 10685257
TI - Noninvasive validation of tobacco smoke exposure in late pregnancy using end
tidal carbon monoxide measurements.
AB - OBJECTIVE: To determine whether exposure to tobacco smoke in late pregnancy can
be reliably estimated by measuring carbon monoxide (CO) in the mother and newborn
breath. STUDY DESIGN: Sixty-eight mothers and their healthy term singleton
newborns, delivered at a university-affiliated community hospital in Jerusalem,
were enrolled. End-tidal CO (corrected for inhaled air [ETCOc] was measured with
a portable automated bedside CO analyzer. ETCOc, cotinine, and carboxyhemoglobin
(COHb) levels were compared in 17 smoking, 31 passively exposed, and 20
nonsmoking mothers and their offspring. RESULTS: The mean +/- SD ETCOc was
significantly higher in women who smoked than in passively exposed and nonsmoking
mothers (8.42 +/- 5.65 vs 1.95 +/- 0.98 vs 1.33 +/- 0.84 ppm. p < 0.0001,
respectively). Newborns whose mothers smoked had higher ETCOc levels than those
of infants of passively exposed and nonsmoking mothers (10.0 +/- 7.7 vs 2.51 +/-
1.4 vs 1.74 +/- 0.98 ppm, p < 0.0001, respectively). The number of cigarettes
smoked by the mother was significantly correlated with maternal ETCOc (r = 0.755,
p < 0.00001), and neonatal ETCOc (r = 0.805, p < 0.00001). Maternal ETCOc was
highly correlated with neonatal ETCOc (r = 0.857, p < 0.00001), cotinine (r =
0.645, p < 0.00001), and COHb (r = 0.9, p < 0.00001) levels. Birth weight was
significantly associated with neonatal ETCOc (p < 0.006) and maternal ETCOc (p <
0.007). CONCLUSION: ETCOc levels in the newborn are well correlated with maternal
smoking. Measurements of newborn ETCOc may be used as a noninvasive means to
estimate exposure to maternal tobacco smoke immediately before delivery. These
measurements will be useful for patient education and research.
PMID- 10685258
TI - Contribution of heating, ventilation, and air conditioning airflow and
conversation to the ambient sound in a neonatal intensive care unit.
AB - Sound reduction strategies in the neonatal intensive care unit (NICU) must focus
on the sources of excessive sound. We studied the relative contribution of
personnel conversation and heating, ventilation, and air conditioning (HVAC)
airflow by measuring several parameters of sound during four environmental
conditions: unaltered ambient sound, HVAC airflow off, HVAC airflow and
conversation off, and conversation off. All measurements were decreased by
interrupting HVAC airflow and conversation. The reduction was greater when
conversation was stopped. The method of sound reduction did not change the
frequency distribution of sound. Attention to personnel conversation may be
effective in lowering sound exposure in the NICU. The contribution of HVAC
airflow should be measured in new constructions and renovations.
PMID- 10685259
TI - Identifying at risk infants following neonatal extracorporeal membrane
oxygenation.
AB - OBJECTIVE: To identify infants at risk of death and abnormal neurodevelopmental
outcome following extracorporeal membrane oxygenation (ECMO) in the neonatal
period. METHODS: The medical records of 82 neonates treated with ECMO were
reviewed to evaluate risk of death. All survivors were followed by neurologic
examinations and tested using the Bayley Scales of Infant Development or McCarthy
Scale of Children's Abilities, and risk for abnormal neurodevelopmental outcome
was assessed. RESULTS: The overall survival was 91% (75 of 82). The mean
gestational age and birth weight of nonsurvivors were lower than those of
survivors (37 +/- 1 weeks vs 40 +/- 0 weeks; 2734 +/- 230 vs 3325 +/- 69 gm, p <
0.05). Infants who were lost to follow-up (16%) did not differ from those with
follow-up in demographic variables or clinical indicators of illness severity.
Thirty-five of 63 infants (56%) with follow-up had normal neurodevelopmental
outcome. Risk of abnormal outcome was higher in infants requiring assisted
ventilation for > or = 15 days (relative risk [RR] 5.5; 95% confidence interval
[CI] 2.0 to 14.8), supplemental oxygenation for > or = 22 days (RR 3.1; 95% CI
1.3 to 7.6), and black race (RR 8.9; 95% CI 1.3 to 62.9). None of the
neuroimaging studies accurately predicted the neurodevelopmental outcome of these
infants. CONCLUSION: We conclude that ECMO in critically ill infants is
associated with good survival. The need for prolonged respiratory support may
help in identifying infants at risk for abnormal neurodevelopmental outcome.
PMID- 10685260
TI - Impact of pediatric ethics consultations on patients, families, social workers,
and physicians.
AB - OBJECTIVE: To evaluate whether health providers and families find ethics
consultations helpful in identifying, analyzing, and resolving ethical problems.
STUDY DESIGN: Forty consecutive pediatric ethics consultations at the San Diego
Children's Hospital and Health Center were evaluated retrospectively through
chart reviews and structured interviews with physicians, social workers, and
family members. RESULTS: In 23 of 40 cases, physicians or social workers were
successfully interviewed. Of these 23 cases, four family interviews were
completed. Over 90% of physicians and social workers found the ethics
consultation to be helpful and would recommend an ethics consultation to others
in the same circumstances. Two of the four families were strongly dissatisfied
with the consultation and identified miscommunication of the ethics consultant's
role as a major problem. CONCLUSION: The disparity observed in this study between
satisfaction levels of health providers and families raises concerns. More
studies that evaluate ethics consultations are needed, especially those that are
designed prospectively and explore both these perspectives.
PMID- 10685261
TI - Maternal hypoglycemia: is it associated with adverse perinatal outcome?
AB - OBJECTIVE: To determine if maternal hypoglycemia is associated with adverse
perinatal outcome, particularly low birth weight. STUDY DESIGN: In this
prospective study, all patients after 24 weeks' gestation were screened for
gestational diabetes using 50 gm of glucola (oral) followed by a 1-hour plasma
glucose measurement and hypoglycemia was defined as < or = 88 mg/dl. RESULTS: In
these 426 women the mean (+/- SD) 1-hour plasma glucose value was 99.8 +/- 22.7
mg/dl. Of these, 16 were diagnosed with gestational diabetes and 46 were lost to
follow-up leaving 364 patients; 116 with hypoglycemia and 248 with euglycemia.
Women with hypoglycemia weighed less at the beginning of pregnancy and at
delivery, but total weight gain during pregnancy was similar between both groups.
There was no difference between groups in maternal symptomatology, birth weight,
or the rate of fetal growth restriction. CONCLUSION: Hypoglycemia on the 1-hour
glucola screen is not predictive of fetal growth restriction or other adverse
perinatal consequence.
PMID- 10685262
TI - Unilateral do-not-resuscitate order in the neonatal intensive care unit.
PMID- 10685263
TI - Treatment of neonatal infection caused by coxsackievirus B3.
AB - Four male infants with early neonatal infection caused by coxsackievirus B3
(presumed in one case) exhibited severe thrombocytopenia and liver dysfunction at
presentation. The three infants who were administered human normal immunoglobulin
within 3 days of disease onset survived, while the fourth infant, who received
the preparation 6 days after disease onset, died.
PMID- 10685264
TI - Curling's ulcer in association with staphylococcal scalded skin syndrome in the
neonate.
PMID- 10685265
TI - Placental pathology casebook. Chorangiosis of the placenta increases the
probability of perinatal mortality.
AB - Two apparent acute problems that may occur in labor, nuchal cord and placental
abruption, were associated with chorangiosis of the placenta. The importance of
complete placental examination in perinatal mortality is re-emphasized. The
association of apparent acute obstetrical conditions, e.g., nuchal cord and
placental abruption with chorangiosis of the placenta, may be the cause of fetal
newborn deaths that were previously assumed to be issues of labor management.
PMID- 10685267
TI - Informed consent: are we there?
PMID- 10685266
TI - Perinatal/neonatal transport casebook. A 3-week-old female infant with a cough
and limp spells.
PMID- 10685268
TI - Neurodevelopmental outcome of prematurely born children treated with recombinant
human erythropoietin in infancy.
AB - OBJECTIVE: To compare the neurodevelopmental outcome of premature infants treated
with recombinant human erythropoietin with that of control infants. STUDY DESIGN:
A total of 20 treated infants and 20 control infants who had completed
randomized, double-blind, placebo-controlled studies of recombinant human
erythropoietin as treatment for anemia of prematurity were followed for growth
and developmental outcome in an intensive care nursery follow-up program. Infants
were assessed by standard developmental tests. RESULTS: No differences were found
between groups for neurologic outcome, cognitive outcome, or growth patterns. All
infants treated with recombinant human erythropoietin were neurologically normal.
The rate of cognitive deficits was similar in the two groups. CONCLUSION: In this
small sample we did not see differences in neurodevelopmental outcome between
infants treated with recombinant human erythropoietin and control infants.
PMID- 10685269
TI - Relationship of amniotic fluid markers of intra-amniotic infection with
histopathology in cases of preterm labor with intact membranes.
AB - OBJECTIVE: To evaluate the correlation of amniotic fluid (AF) markers (AFMs) of
intra-amniotic infection with histopathologic findings in cases of preterm labor
with intact membranes, between 22 and 36 weeks' gestation. STUDY DESIGN: We
reviewed the charts of patients admitted in preterm labor with intact membranes
between January 1993 and December 1996. Those having amniocentesis were
identified, and AFMs were compared with histopathology in patients who delivered
within 48 hours of the amniocentesis. The AFMs evaluated were glucose,
polymorphonuclear leukocytes, Gram stain, and culture. All placentae were
reviewed by a single pathologist blinded to the AF findings. Histologic evidence
of acute inflammation was defined by findings of both subchorial intervillositis
and marginating choriodeciduitis. The sensitivities, specificities, and positive
and negative predictive values of the various AFMs were calculated. RESULTS: Of
556 women with intact membranes presenting in preterm labor, 181 (32.6%) had
amniocentesis and 88 delivered within 48 hours of the amniocentesis.
Histopathologic chorioamnionitis was seen in 53 patients (60.2%). The findings
(with their sensitivity, specificity, and positive and negative predictive
values) were: polymorphonuclear leukocytes at > 10/high-power field (22.6%,
97.2%, 92.3%, and 46.1%), positive Gram stain (26.4%, 94.6%, 87.5%, and 47.3%),
culture (28.3%, 92.1%, 83.3%, and 47.9%), and glucose of < 15 mg/dl (28.3%,
94.6%, 88.2%, and 47.9%), respectively. Using a receiver-operator characteristic
curve for different level of AF glucose, a glucose level of < 20 mg/dl was the
most sensitive AF predictor of histologic chorioamnionitis. CONCLUSION:
Histopathologic evidence of chorioamnionitis was present in 60.2% of cases of
preterm births due to preterm labor in women who at our institution were offered
and accepted amniocentesis and subsequently delivered within 48 hours. AFMs may
be useful predictors of histologic chorioamnionitis. The most efficient AFM for
chorioamnionitis in this group of patients was glucose at < 20 mg/dl.
PMID- 10685270
TI - A randomized trial of nasopharyngeal-synchronized intermittent mandatory
ventilation versus nasopharyngeal continuous positive airway pressure in very low
birth weight infants after extubation.
AB - OBJECTIVE: To prospectively compare the incidence of respiratory failure in
premature infants randomized to receive either nasopharyngeal continuous positive
airway pressure (NPCPAP) or nasopharyngeal-synchronized intermittent mandatory
ventilation (NP-SIMV) in the immediate postextubation period. STUDY DESIGN: This
is a prospective study of very low birth weight (VLBW) infants randomized at the
time of extubation to receive either NPCPAP or NP-SIMV in a university-based
level III neonatal intensive care unit. Statistical analysis were performed with
the Mann-Whitney U test for continuous and ordinal variables, and with the chi
squared test or Fisher's exact test for categorical variables. RESULTS: A total
of 41 VLBW infants were studied; 19 were in the NPCPAP group, and 22 were in the
NP-SIMV group. Respiratory failure after extubation in the NP-SIMV group was
significantly lower that in the NPCPAP group (5% vs 37%, respectively (p =
0.016). No statistically significant differences between groups with regard to
demographics, severity of initial illness and associated complications, time to
extubation, ventilatory management before extubation, weight, age, or nutritional
status at the time of extubation were noted.
PMID- 10685271
TI - Effects of antenatal corticosteroids on blood pressure in very low birth weight
infants during the first 24 hours of life.
AB - OBJECTIVE: We tested the hypothesis that prenatal glucocorticoids significantly
increase mean arterial blood pressure in very low birth weight preterm infants
during the first 24 hours after birth. STUDY DESIGN: Prospectively collected data
from 178 inborn infants with birth weights between 500 and 1499 gm were examined.
A total of 80 infants were born to mothers treated with corticosteroids (birth
weight: 1057 +/- 271 gm, gestational age: 28.0 +/- 2.6 weeks), and 98 infants
were untreated controls (birth weight: 1030 +/- 280 gm, gestational age: 28.0 +/-
2.8 weeks). The study setting was a university-based tertiary care center for
newborn intensive care. RESULTS: Mean blood pressures on admission and at 3, 6,
12, 18, and 24 hours were significantly higher in steroid-treated infants.
Steroid-treated infants received significantly less volume expansion (3.8 +/- 8.5
ml/kg versus 14.4 +/- 20.7 ml/kg; p < 0.001) than controls. Vasopressor support
was also reduced in the steroid group (2.5% versus 11.5%; p < 0.05). CONCLUSION:
Antenatal steroids are associated with both a higher mean systemic blood pressure
and a decreased use of vasopressors and plasma expanders in very low birth weight
infants during the first 24 hours after birth. This effect is not limited to
infants of < 1000 gm; it is also significant in infants with a birth weight
between 1000 and 1499 gm, and is already detectable in the first hours of life.
We speculate that this finding may contribute to the mechanism of steroid
protection against conditions such as intraventricular hemorrhage.
PMID- 10685272
TI - Skin care management practices for premature infants.
AB - OBJECTIVE: To describe current skin care practices for preterm infants in
neonatal intensive care units in the United States. We hypothesized that there
would be little consensus among facilities. STUDY DESIGN: Neonatal intensive care
units (n = 823) listed in the 1996 United States Neonatologists Directory
(American Academy of Pediatrics, Section on Perinatal Pediatrics) were sent a 28
question survey dealing with many aspects of neonatal skin care along with
descriptive data about their neonatal intensive care unit. Descriptive data
analysis was performed. RESULTS: A total of 305 surveys were returned (37% return
rate); of these, 241 of the respondents reported admitting infants weighing < or
= 1000 gm. Some neonatal skin care practices showed wide consensus (> 70%) (e.g.,
scrub procedure for staff; use of a skin barrier under tapes/adhesives), whereas
other practices showed little consensus (< 30%) (e.g., routine surveillance
cultures; use of Aquaphor). CONCLUSION: Consensus on skin care practices was not
found among neonatal intensive care units. Data from this survey can be used to
develop studies to examine whether certain skin care management practices can
improve neonatal outcomes.
PMID- 10685273
TI - Effect of the maternal care manual of the perinatal education programme on the
ability of midwives to interpret antenatal cards and partograms.
AB - OBJECTIVE: To assess the ability of midwives to interpret antenatal cards and
partograms correctly following completion of the Maternal Care Manual of the
Perinatal Education Programme. STUDY DESIGN: We conducted a prospective,
controlled trial in a study town and two control towns in the Eastern Cape
Province of South Africa. All 93 midwives caring for pregnant women in the three
towns were included in the study. Samples were compared using the two-tailed
Student's t-test. RESULTS: The marks achieved by the study group for questions
from the antenatal card and the partogram improved by 33.0% (p < 0.001) and 17.5%
(p = 0.001), respectively. No changes were observed in the control group.
CONCLUSION: Midwives that studied the Maternal Care Manual significantly improved
their ability to interpret clinical information and apply knowledge. If this
ability is applied in clinical practice, a reduction in maternal and perinatal
deaths is possible.
PMID- 10685274
TI - Survival, intracranial lesions, and neurodevelopmental outcome in infants with
congenital diaphragmatic hernia treated with extracorporeal membrane oxygenation.
AB - OBJECTIVE: Before the use of extracorporeal membrane oxygenation (ECMO), infants
with a severe form of congenital diaphragmatic hernia (CDH) had a high mortality
and morbidity. Recent studies have shown an improvement in the survival of these
infants after ECMO treatment; however, the existing data do not provide
sufficient informations regarding the quality of survival and developmental
outcome of these infants. The objective of this study was to evaluate survival,
intracranial lesions, and the neurodevelopmental outcome of infants with CDH
treated with ECMO. METHODS: We retrieved data for 51 (n = 51) infants with CDH
who were treated with ECMO at Huntington Memorial Hospital between 1985 and 1994.
Their mean gestational age was 38.5 +/- 2.4 weeks (mean +/- SD); their mean birth
weight was 3170 +/- 620 gm. Vital signs, arterial blood gases, chest radiographs,
cranial and cardiac ultrasonography were routinely obtained before ECMO
treatment. Cranial ultrasounds were performed daily on all infants while on ECMO;
computerized tomography scans were obtained on all infants after completion of
ECMO treatment. The surviving infants were followed at our neonatal follow-up
clinic for neurodevelopmental assessment. RESULTS: A total of 39 infants were
placed on venoarterial ECMO and 12 infants were placed on venovenous ECMO; a
total of 35 infants had CDH repair before ECMO, whereas 16 infants had delayed
surgery. A total of 31 infants (61%) survived. The infants who survived had a
mean pH of 7.33 +/- 0.20, mean airway pressure of 19.6 +/- 5.8 cm H2O, and an
oxygenation index (OI) of 87 +/- 55 before ECMO intervention. The infants who
expired (n = 20) had a mean pH of 7.31 +/- 0.15, mean airway pressure of 23.1 +/-
5.5 cm H2O, and a mean oxygenation index of 127 +/- 56 before ECMO treatment.
Before ECMO, survivors had a significantly lower oxygenation index and a higher
Pao2 compared with nonsurvivors (p < 0.01). A total of 18 infants (35%) had
abnormal central nervous system findings. Of the 51 infants, 10 had ventricular
dilatation, 6 had intracranial hemorrhage, and 11 had focal or diffuse cerebral
atrophy diagnosed by computerized tomography scan or at autopsy (1 patient had an
infarct). Eight infants had more than one central nervous system abnormality. A
total of 16 survivors had a neurodevelopmental evaluation at 12 months, and 11 of
these survivors were evaluated at 24 months of age (Bayley Scales of Infant
Development). The developmental progress of these infants falls within the low
average range of cognitive and motor abilities. Their mean Bayley Mental
Developmental Index was 85 +/- 25 (50 to 145) at 24 months; their Psychomotor
Developmental Index was 89 +/- 21 (50 to 113) at 24 months of age. Follow-up at 4
and 6 years of age is in progress. CONCLUSION: Our preliminary findings indicate
that 35% of infants with severe CDH requiring ECMO had central nervous system
abnormalities (intracranial lesions, including ventricular dilatation). The
survival rate in our study population is consistent with recent reports. As a
group, infants with severe CDH display mild neuromotor and cognitive delay in
development at 24 months of age.
PMID- 10685275
TI - Alveolar capillary dysplasia: diagnostic potential for cardiac catheterization.
AB - OBJECTIVE: Alveolar capillary dysplasia is a rare cause of persistent pulmonary
hypertension of the newborn. Infants with this condition die despite maximal
medical intervention including inhaled nitric oxide therapy and extracorporeal
membrane oxygenation. To date, diagnosis of this lethal condition was made by
open lung biopsy or during postmortem examination. We examined the possibility
that distinct cardiac catheterization findings could be used in the diagnosis of
this lethal disorder. STUDY DESIGN: We present three infants with fatal
persistent pulmonary hypertension of the newborn refractory to extracorporeal
membrane oxygenation and inhaled nitric oxide therapy, two with postmortem
autopsy confirmation of alveolar capillary dysplasia. Each infant underwent
cardiac catheterization to complete the diagnostic evaluations. RESULTS:
Significant right ventricular hypertension and normal pulmonary venous return
were demonstrated, but a markedly diminished or absent capillary blush phase was
noted in each infant. This finding is distinct from the normal capillary blush
seen in infants with persistent pulmonary hypertension of the newborn of other
etiologies. CONCLUSION: Cardiac catheterization may provide a useful alternative
to tissue examination in the diagnosis of alveolar capillary dysplasia.
PMID- 10685276
TI - Focal neurological manifestations following aberrant central venous catheter
placement.
AB - An infant developed focal tonic clonic movements of both lower limbs while
receiving total parenteral nutrition through a left saphenous percutaneous
central venous catheter. Radiographic studies using a contrast confirmed that the
catheter tip was located in the ascending lumbar vein in close proximity to the
epidural space. Withdrawal of the catheter abated all clinical symptoms. This
case emphasizes the need to confirm central venous catheter placement and
illustrates yet another risk associated with the infusion of parenteral
alimentation.
PMID- 10685277
TI - Dissemination of the kangaroo method in Germany.
PMID- 10685278
TI - Gestation versus outcome table for parents of extremely premature infants.
AB - Parents of extremely premature babies may have problems understanding and
remembering information on likely outcome. We have constructed a simplified
evidence-based "gestation versus outcome" table that could be offered to the
parents. Such a table may promote consistency in the information given to parents
by different members of the perinatal team.
PMID- 10685279
TI - Lethal pulmonary hypoplasia and hydrocolpos with transverse vaginal septum in a
newborn: a case report and review of the literature.
AB - This is a case report of an unusual cause of Potter sequence. Autopsy showed
lethal pulmonary hypoplasia in association with a transverse vaginal septum,
hydrocolpos, and a secondary obstructive uropathy.
PMID- 10685280
TI - Association of maternal sertraline (Zoloft) therapy and transient neonatal
nystagmus.
PMID- 10685281
TI - Bacteremia, meningitis, and brain abscesses in a hospitalized infant:
complications of Pseudomonas aeruginosa conjunctivitis.
AB - This report describes a preterm infant hospitalized in a neonatal intensive care
unit who developed Pseudomonas aeruginosa conjunctivitis associated with
bacteremia, meningitis, and multiple brain abscesses. P. aeruginosa
conjunctivitis can rapidly progress to an invasive eye infection, such as corneal
ulceration or endophthalmitis, leading to poor vision or blindness. Progression
of this infection may lead to systemic disease. However, as illustrated in this
report, P. aeruginosa conjunctivitis may be associated with the development of
systemic complications such as bacteremia and meningitis in the absence of
invasive eye disease. P. aeruginosa is a relatively common cause of
conjunctivitis in hospitalized preterm and low birth weight infants. Given the
severity of the ocular and systemic complications of Pseudomonas conjunctivitis,
clinicians are reminded that prompt detection and treatment of neonatal
conjunctivitis is critical.
PMID- 10685282
TI - Umbilical cord blood gases casebook. Interpreting umbilical cord blood gases, V.
PMID- 10685283
TI - Special imaging casebook. Congenital adrenal neuroblastoma with renovascular
hypertension.
PMID- 10685284
TI - Radiology casebook. Intussusception in a premature infant: a case report.
PMID- 10685285
TI - Is community important for health?: examining the biopsychosocial interface.
AB - The United States has created the most expensive, technologically advanced
medical system in the world. Health outcomes, however, fail to achieve results
commensurate with investment. After identifying the scope of population health
concerns untreated by the current U.S. healthcare system, an explanatory model
suggests that the relational basis of health and adaptation has been neglected by
providers and policymakers. Finding root sources of health in the strength of
relationships between individuals and within communities, recommendations are
made for applying an integrated model of personal, community, and national
health.
PMID- 10685286
TI - How to help parents of young children: the touchpoints model.
PMID- 10685287
TI - Community efforts to improve perinatal care: a clinical pathologic conference.
PMID- 10685288
TI - National Perinatal Association (NPA) debate: should the legislature regulate
perinatal practice?
PMID- 10685289
TI - Two tools for well-being: health systems and communities.
AB - Medical systems are tools of limited power to improve health status in modern
societies. The associational tools of local communities are now the most
important health-giving resources. Health professionals must learn the nature of
these tools and understand their relation to and support of them.
PMID- 10685290
TI - From public health to population health: epidemiological yardsticks for perinatal
care.
AB - Perinatal epidemiology and health services research have focused on specific
health outcomes or disease states ("key" indicators and/or sentinel events),
clients of public programs, and clinical service populations. In this paper, the
concept of "population health" is defined and operationalized for the broad
perinatal healthcare context within the framework of population health
informatics. Traditional indicators and outcome measures for perinatal health are
compared with some newer measures and assessed for their relevance to population
health. A hypothetical model for the implementation of population health
informatics for maternal and child health is described; in addition, and some
obstacles to the practice of population health are identified, with strategies to
overcome these obstacles.
PMID- 10685291
TI - The relational basis of health: woman's voice.
AB - Using voice as a metaphor, this paper will speak to the necessity of health care
providers to "hear" the language of women, promote validity to their experiences,
and facilitate their relational connections in their evolving roles as mothers.
PMID- 10685292
TI - Efficacy and justice: the importance of medical research and tertiary care to
social disparities in infant mortality.
PMID- 10685293
TI - Communication gap.
PMID- 10685294
TI - Influence of postdatism and meconium on fetal erythropoietin.
AB - OBJECTIVE: To determine whether fetal erythropoietin (Epo) concentrations are
increased in pregnancies extending beyond 41 weeks' gestation and whether this is
influenced by the presence of meconium-stained amniotic fluid. METHODS: Epo
concentrations were measured in 116 fetal umbilical cord blood samples from
otherwise uncomplicated pregnancies between 37 to 43 weeks' gestation during the
period of October 1996 to October 1997. An enzyme-linked immunosorbent assay kit
was used to measure Epo. Maternal demographics and birth outcomes including Apgar
score, cord blood pH, and base deficit were obtained. Fetuses born between 41 and
43 weeks' gestation (post-term) were compared with matched controls born between
37 and 40 weeks' gestation (term). In addition, both post-term and term fetuses
with meconium-stained amniotic fluid were compared with matched controls without
meconium. RESULTS: Post-term fetuses without meconium had significantly higher
Epo levels compared with term fetuses (mean +/- SEM: 50.6 +/- 6.5 versus 29.5 +/-
3.3 mIU/ml, p = 0.002). When matched for gestational age, fetuses with meconium
stained amniotic fluid had significantly greater Epo concentrations compared with
controls without meconium (post-term, 80.7 versus 50.6 mIU/ml; term, 61.4 versus
29.5 mIU/ml; p < 0.05). However, no significant difference in Epo levels was
found between post-term fetuses with meconium and term fetuses with meconium
(80.7 +/- 15.7 mIU/ml versus 61.4 +/- 12.8 mIU/ml, respectively). Mean cord blood
pH and base deficit values for all groups were within normal clinical range.
CONCLUSION: Cord blood Epo concentrations were significantly increased in
pregnancies extending beyond 41 weeks. Irrespective of gestational age, meconium
stained amniotic fluid was associated with a significant rise in Epo. High Epo
levels in these pregnancies imply subacute or chronic fetal hypoxia. Close
clinical monitoring of post-term fetuses and those with meconium-stained amniotic
fluid is warranted.
PMID- 10685295
TI - Human immunodeficiency virus (HIV)-related risk-taking behaviors in women
attending inner-city prenatal clinics in the mid-west.
AB - OBJECTIVE: Federal guidelines recommend the provision of human immunodeficiency
virus education to all attendees of prenatal clinics. The current study was
conducted to assess risk-taking behaviors among urban women voluntarily pursuing
prenatal care. DESIGN AND SETTING: African American women attending urban
prenatal clinics in Cleveland, Ohio were subjected to an extensive interview
before receiving an experimental AIDS education curriculum. The interview sought
detailed information regarding demographics, lifetime and recent sexual activity,
condom use, and lifetime and recent illicit drug use. RESULTS: A total of 1017
women were interviewed; of those women, approximately 73% were single. The
majority had a monthly income of less than $500. A total of 66% had only one
partner in the past year, and almost 90% had < or = 1 partner in the past 6
months. A total of 98% identified a main partner. Nearly all subjects were at
least fairly certain that this partner did not use intravenous drugs, and 71%
were at least fairly certain that he was monogamous. Only 19% used condoms most
or all the time. Intravenous drug use among study subjects was very infrequent.
CONCLUSION: These data indicate that inner-city Cleveland women seeking prenatal
care are largely monogamous around the time of their gestation, and that a
history of intravenous drug use is infrequent. They suggest that prenatal
counseling in urban clinics will need to address women who largely are engaged in
single-partner relationships at the time of the intervention.
PMID- 10685296
TI - Predictors of symptomatic urinary tract infection after 20 weeks' gestation.
AB - OBJECTIVE: To identify predictors of symptomatic urinary tract infection (UTI)
after 20 weeks' gestation. STUDY DESIGN: A retrospective cohort analysis was
conducted of all deliveries at three North Carolina hospitals between 1990 and
1993. A total of 7403 deliveries remained after exclusions (pre-pregnancy
diabetes, HIV-positive, structural urologic abnormalities, no prenatal care) and
restrictions (black or white race, county of residence). Cystitis and
pyelonephritis were identified by clinician diagnosis. Multiple logistic
regression was conducted. RESULTS: Prior UTIs (both before and earlier in
pregnancy), nonprivate clinics, and a history of chlamydia (white women only)
doubled the risk of symptomatic UTIs after 20 weeks' gestation. The strongest
predictor of pyelonephritis was prior antenatal UTIs (adjusted incidence odds
ratio = 5.3, 95% confidence interval of 2.6-11.0), followed by less education (<
12 years), a history of chlamydia, nonprivate clinics, illicit drug use, sickle
cell hemoglobinopathy, and being unmarried. CONCLUSION: Medical history and
demographic factors predict cystitis and pyelonephritis after 20 weeks'
gestation. Prospective studies of pyelonephritis predictors and screening
strategies are warranted.
PMID- 10685297
TI - Sound transmission into incubators in the neonatal intensive care unit.
AB - OBJECTIVE: To measure the attenuation of sound by modern incubators. STUDY
DESIGN: LEQ, LMAX, LPEAK, and frequency distribution were measured simultaneously
inside and outside two recent model incubators. RESULTS: The attenuation of sound
(outside minus inside) was 15 to 18 dBA with the motor off and 4 to 8 dBA with
the motor on. There was a significant difference between incubators in their
attenuation of sound. Octave band analysis showed attenuation in frequency bands
of > 31.5 Hz with the motor off. With the motor on, the sound level inside the
incubator was higher than outside at frequency bands of < 250 Hz. CONCLUSION:
Caring for infants inside modern incubators reduces "averaged" sound exposure to
levels near those recommended for the neonatal intensive care unit. Lower
frequency sounds are louder inside the incubator and arise from the incubator
motor.
PMID- 10685298
TI - Nephrocalcinosis in premature infants: variability in ultrasound detection.
AB - OBJECTIVE: To measure variability among radiologists in the ultrasound diagnosis
of nephrocalcinosis in premature infants. METHODOLOGY: In this prospective
multicenter study, renal ultrasounds were performed on 54 very low birth weight
infants using a 5.0- and 7.5-MHz transducer, and these ultrasounds were read
independently by three radiologists. kappa coefficients were calculated to assess
variability in identification of nephrocalcinosis among the radiologists.
RESULTS: The kappa coefficient (+/- confidence intervals) using a 5.0-MHz
transducer was 0.143 (0.108, 0.178); using the 7.5-MHz transducer, the kappa
coefficient was 0.268 (0.243, 0.293). All three radiologists agreed in their
identification of nephrocalcinosis on 3 of 54 ultrasounds using a 5.0-MHz
transducer; a total of 6 of 54 ultrasounds obtained using a 7.5-MHz transducer
were read as positive by all three radiologists. CONCLUSION: There is significant
variability among radiologists in the ultrasound identification of
nephrocalcinosis in premature infants; a 7.5-MHz ultrasound transducer is
associated with less variability in recognizing this lesion.
PMID- 10685299
TI - Relationship between perinatal counseling and incidence of breastfeeding in an
inner-city population.
AB - OBJECTIVE: We hypothesized that the cost of a lactation program can be reduced
without significantly affecting the incidence of breastfeeding. STUDY DESIGN: We
conducted a retrospective analysis of breastfeeding among all 7942 mothers whose
neonates were admitted to the well baby nursery at Jacobi Medical Center (JMC)
over a 44-month period. We used multiway frequency analysis to compare the
incidence of breastfeeding in three successive models of counseling: (1) full
time lactation coordinator, (2) obstetric personnel trained in breastfeeding
counseling and full-time lactation coordinator, and (3) obstetric personnel and
half-time lactation coordinator. Mothers were further classified into three
groups according to location of prenatal care and attendance at breastfeeding
education sessions. RESULTS: Breastfeeding increased with the initiation of
education and the involvement of obstetric personnel and did not significantly
decrease when the lactation coordinator became half-time. The transition to model
3 resulted in decreased costs without significantly affecting the incidence of
breastfeeding. Breastfeeding was significantly associated with counseling by
obstetric personnel, with prenatal care at JMC, and with breastfeeding education
sessions. CONCLUSION: Involving obstetric personnel in breastfeeding counseling
may enhance the effectiveness of a lactation program. In our population, the most
cost-conscious model included counseling by trained obstetric personnel and a
half-time lactation coordinator.
PMID- 10685300
TI - Weekly telephone contact does not enhance the compliance of home apnea
monitoring.
AB - OBJECTIVE: To evaluate the effect of weekly telephone contact with families in
enhancing the use of home apnea monitors. STUDY DESIGN: This was a prospective,
randomized, single-blinded study of 65 infants who were prescribed home apnea
monitoring at the time of initial discharge from the hospital. Exclusion criteria
included participation in any other study involving home monitoring or
nonavailability of home telephone. Infants were randomized either to the
"standard" or "telephone" group by a stratified balanced block technique. All
families were instructed to use the monitor during the first 4-week period at all
times except during bathing and during the second 4-week period at all unattended
times and at night. The families in the telephone group were contacted weekly for
8 weeks. The telephone interview reviewed the events of the previous week but did
not include specific encouragement to use the monitor. Both groups received
routine pediatric care and follow-up at our high-risk premature clinic. The
primary outcome measure was compliance measured as the percentage of time as well
as the hours per day that the infant spent on the monitor as recorded by the
documented monitor. RESULTS: The telephone (n = 30) and standard (n = 32) groups
were similar (p > 0.10) with respect to birth weight (1567 +/- 778 versus 1710 +/
777 gm), gestational age (30.9 +/- 4.2 versus 31.1 +/- 4.6 weeks), maternal age
(24.9 +/- 6.0 versus 25.3 +/- 5.4 years), and commercial insurance (46.7% versus
46.9%), a marker of higher socioeconomic status. Compliance of the telephone
versus the standard group was similar during the first 4-week period (74.7 +/-
24.9 versus 75 +/- 27.8%, p = 0.85) (17.9 +/- 5.9 versus 18.2 +/- 6.6 hours/day),
the second 4 week period (63.4 +/- 29.1 versus 58.9 +/- 30.9%, p = 0.59) (15.2 +/
7.0 versus 14.1 +/- 7.4 hours/day) and the entire 8-week period (69.3 +/- 24.7
versus 67.7 +/- 26.2%, p = 0.82, Mann-Whitney U-test) (16.7 +/- 6.0 versus 16.1
+/- 6.5 hours/day), respectively. An abnormal pneumocardiogram at the time of
discharge was the only identified factor that improved the compliance for the
entire 8-week period (73.1 +/- 22 versus 52.1 +/- 28.5%, p = 0.02) (17.5 +/- 5.2
versus 12.5 +/- 6.8 hours/day) and the first 4-week period of monitoring (81.7 +/
22.9 versus 59.5 +/- 31.3%, p = 0.01) (19.6 +/- 5.5 versus 14.2 +/- 7.5
hours/day). CONCLUSION: Weekly telephone contact, without specific encouragement
to use the monitor, did not improve compliance. Compliance was greater in
subjects who had abnormal pneumocardiogram results at the time of discharge from
hospital regardless of their telephone/standard group assignment. We speculate
that in this already compliant population, more targeted advice is necessary to
increase compliance.
PMID- 10685301
TI - Use of positioning to reduce the severity of neonatal narcotic withdrawal
syndrome.
AB - OBJECTIVE: This study tested the hypothesis that highly fretful, narcotic
withdrawing neonates experience less distress in a prone-lying position than
comparable, supine-lying neonates. STUDY DESIGN: Equivalent numbers of randomly
assigned, narcotic-withdrawing newborns were assigned to prone-lying (n = 25) or
supine-lying (n = 23) conditions. Subjects in the two groups were similar with
regard to gestational age, birth weight, and clinical presentation. Peak and mean
withdrawal severity, as measured by Neonatal Abstinence Scoring System (NASS)
scores and daily caloric intake, were compared between supine and prone groups by
Wilcoxon's two-sample test. RESULTS: The prone-lying neonates had lower peak NASS
scores (p < 0.0001), lower mean NASS scores (p < 0.0001), and lower caloric
intake (p < 0.001) than supine-lying, narcotic-withdrawing newborns. CONCLUSION:
The fretfulness associated with neonatal withdrawal and other stressful
conditions can be moderated by laying the affected infant prone. The pronate
quieting response is a significant, endogenous source of neonatal pacification.
PMID- 10685302
TI - Maternal and fetal factors related to abnormal amniotic fluid.
AB - OBJECTIVE: The objective of this study was to identify maternal and infant
characteristics related to alteration of amniotic fluid volume at birth. STUDY
DESIGN: A series of 27,145 consecutive malformed newborn infants from the Spanish
Collaborative Study of Congenital Malformations (ECEMC) was analyzed. From this
total, 3.01% were found to have oligohydramnios and 3.69% were found to have
polyhydramnios. RESULTS: As expected, renal/urinary tract and lung defects were
associated with oligohydramnios, whereas esophageal and intestinal atresias,
neural tube defects, and other central nervous system malformations were
associated with polyhydramnios. In addition, other defects such as cardiovascular
anomalies, hydrocephaly, and microcephaly were also related to abnormalities of
amniotic fluid volume. After excluding the defects whose association to oligo- or
polyhydramnios is well recognized, we compared the frequency of different
variables among them and with infants with a normal volume of amniotic fluid. In
comparison with infants with normal amniotic fluid volume, the groups with oligo-
and polyhydramnios had lower birth weight, shorter gestational age and umbilical
cord, higher parental ages, and a greater frequency of spontaneous abortions. The
differences were more marked for weight in newborn infants with oligohydramnios,
and for gestational age, umbilical cord length, number of previous pregnancies,
and spontaneous abortions in polyhydramnios cases. Placental weight was lower in
oligohydramnios cases than in infants with normal amniotic fluid, and higher in
polyhydramnios cases. Parental consanguinity and twinning were more frequent in
polyhydramnios. Maternal morbidity was higher in both groups with abnormal
amniotic fluid volume, especially for acute diseases such as hypertension,
diabetes mellitus, and gestational diabetes. Chromosomal aberrations were more
frequent in the oligo- and polyhydramnios groups than in cases with a normal
volume of amniotic fluid, which supports the suggestion of performing prenatal
cytogenetic analysis in any pregnancy complicated by an abnormal volume of
amniotic fluid. CONCLUSION: The fact that all of these results are similar in the
control group of healthy infants suggests that at least some of the variables
associated with abnormal amniotic volume could be considered as causal factors
altering the production of fluid.
PMID- 10685303
TI - The fetus with gastroschisis managed by a trial of labor: antepartum and
intrapartum complications.
AB - OBJECTIVE: To assess the rate of antepartum and intrapartum complications of
fetuses with antenatally diagnosed gastroschisis managed in a center that
advocates a trial of labor. STUDY DESIGN: A retrospective review. The medical
records of 49 fetuses (1988 to 1997) who were prenatally diagnosed with
gastroschisis by a sonologist in the Ultrasound Genetic Unit, Department of
Obstetrics and Gynecology at Washington University, were reviewed. RESULTS:
Oligohydramnios and intrauterine growth restriction were diagnosed in 23% and 49%
of the pregnancies, respectively. A total of 22 women underwent induction of
labor nine for nonreassuring fetal testing, four for premature rupture of
membranes, five for marked bowel dilatation, one for preeclampsia, and three for
other reasons. Cesarean section (CS) was performed in 16 of 43 (37%) of women.
The indications for CS were fetal distress (9 of 16 women), chorioamnionitis (2
of 16 women), breech presentation (3 of 16 women), and physician discretion (2 of
16 women). No significant differences in Apgar scores were observed between the
fetuses. Fetuses who were delivered by CS for fetal distress were more likely to
have undergone an induction of labor (91% versus 44%), and they were smaller than
fetuses with no evidence of fetal distress (2220 +/- 105 gm versus 2613 +/- 80
gm, p < 0.05). CONCLUSION: The incidence of antepartum and intrapartum
complications in fetuses with gastroschisis is high. The rate of CS can reach
37%. These data may aid clinicians in counseling patients with gastroschisis.
PMID- 10685304
TI - Parent's grand rounds speech on neonatal intensive care unit experience.
PMID- 10685305
TI - Neonatal myiasis: a case report and a role of the Internet.
AB - Maggot infestation (myiasis) can occur in the newborn baby. However, neonatal
myiasis is rare, and there is no published literature on this subject. Rapid
useful information on such an esoteric clinical case can be obtained by searching
the Internet. Effective medical management includes complete removal of the
maggots and offering reassurance to the distraught parents.
PMID- 10685306
TI - "Bloodless" treatment of a Jehovah's Witness infant with ABO hemolytic disease.
AB - An ABO-incompatible term infant girl born to parents who are Jehovah's Witnesses
was admitted to our neonatal unit with a high serum bilirubin level necessitating
exchange transfusion. The parents signed a request that blood should not be
administered under any circumstances. However, they authorized us to apply the
possible alternative treatments of orally administered D-penicillamine (300 mg/kg
per day divided in three doses for 3 days), phototherapy, intravenous fluids, and
recombinant human erythropoietin (200 U/kg subcutaneously on every second day for
2 weeks). Herein, we report the outcome of this baby, who was discharged from the
our unit in good condition after treatment. Her physical growth and motor
milestones at 14 months of age revealed no red flags for neurodevelopmental
maturation. To our knowledge, this is the first case of an infant who received
such a combined alternative (and "bloodless") treatment of serious ABO hemolytic
disease of the newborn.
PMID- 10685307
TI - Fatal early onset infection in an extremely low birth weight infant due to
Morganella morganii.
AB - OBJECTIVE: This paper reports a case of chorioamnionitis due to Morganella
morganii in a mother who presented with ruptured membranes at 24 weeks' gestation
and was treated with dexamethasone and prophylactic ampicillin. Her premature
infant developed severe early onset infection due to the same organism and
expired. STUDY DESIGN: A clinical case report of M. morganii infection
complicating preterm rupture of membranes is presented. Possible risk factors for
maternal and neonatal infection with this organism as well as the therapy of
neonatal M. morganii infection are discussed. RESULTS: Risk factors in the mother
included having a cervical cerclage in place and treatment with dexamethasone and
prophylactic ampicillin. The major risk factors in the infant were maternal
chorioamnionitis and extreme prematurity. The mother responded to treatment with
ampicillin, metronidazole, and gentamicin following delivery and had an
uncomplicated recovery. Her infant developed severe early onset M. morganii
infection complicated by neutropenia, thrombocytopenia, and severe acidosis and
expired. Postmortem cultures of pleural fluid, peritoneal fluid, and blood were
positive despite treatment with gentamicin, an antibiotic to which the organism
was sensitive. CONCLUSION: M. morganii may cause serious infection in pregnancy
and in the neonatal period. The use of dexamethasone and prophylactic ampicillin
may have increased the risk of infection with this ampicillin-resistant organism.
The failure of gentamicin to sterilize the infant's blood and body fluids
emphasizes the necessity of treating such infections with a combination of an
aminoglycoside and a third-generation cephalosporin, such as cefotaxime.
PMID- 10685308
TI - Neonatal pyoscrotum and perforated appendicitis.
AB - Neonatal appendicitis is so unusual that is has been considered nonexistent. We
present the case of a 6 day old male with acute scrotal swelling who was found to
have a perforated appendicitis inside a hernia sac. A literature review supports
the impression that neonatal appendicitis is rare; however, when it occurs inside
a hernia sac, it has a good prognosis.
PMID- 10685309
TI - Progressive tumor necrosis and lethal hyperkalemia in a neonate with
sacrococcygeal teratoma (SCT).
AB - Tumor lysis syndrome is known among patients undergoing induction therapy for
lymphocytic malignancies. Spontaneous tumor lysis in patients with solid tumors
is distinctly rare. To our knowledge, the phenomenon of spontaneous tumor lysis
has been described only once in infancy, in association with the surgical
manipulation of a hepatoblastoma. This is the first report of a newborn with
sacrococcygeal teratoma who experienced spontaneous tumor lysis-induced
hyperkalemia. Because cardiac arrest may be among the leading causes of operative
mortality in babies with sacrococcygeal teratoma, intraoperative monitoring of
serum K+ should be conducted frequently.
PMID- 10685310
TI - Fetal heart rate monitoring casebook. Checkmark fetal heart rate pattern and
normal neonatal outcome.
AB - BACKGROUND: A checkmark pattern of the fetal heart rate (FHR) had been seen in
association with hypoxia in human and animal fetuses. CASE: We report a checkmark
pattern in a fetus of a 26-year-old primigravida who underwent induction of labor
at term. Scalp pH was 7.32. Comprehensive ultrasound examination revealed normal
results. The neonate was born in satisfactory condition. Apgar scores were 7 and
10 at 1 at 5 minutes of life, respectively. CONCLUSION: Checkmark FHR pattern may
be a benign finding; however, if it is detected, it should be closely monitored.
PMID- 10685311
TI - Special imaging casebook. Neonate with osteogenesis imperfecta and asplenia
syndrome with horseshoe adrenal.
PMID- 10685312
TI - Recommended standards for newborn ICU design. Committee to establish recommended
standards for newborn ICU design.
PMID- 10685313
TI - Condoms.
PMID- 10685314
TI - Breakage and slippage of condoms among users in north Gondar Province, Ethiopia.
AB - OBJECTIVE: To determine the frequency of condom breakage and slippage among male
condom users and to analyse some factors affecting condom breakage. DESIGN:
Prospective study undertaken from March to June 1996. SETTING: Gondar, Teda and
Aykel health centres in north Gondar province. PARTICIPANTS: One hundred and
seventy literate male condom users who volunteered to participate in the study
were enrolled, but data were collected and analysed for 143 persons. MAIN OUTCOME
MEASURES: Condom breakage was measured as the number of condom broken while
opening the package, putting on, during intercourse or withdrawal; and condom
slippage was measured as the number of condoms slipped off the penis during
intercourse or withdrawal. RESULTS: Of 143 participants, 26.6% broke condoms.
Total condom breakage rate was 4.6% and slippage rate was 0.1%; half of the
condom breakage occurred at the tip. Condom breakage was more observed in less
educated (p < 0.05). Breakage rate and experience of condom use were negatively
correlated (r = -0.214, P < 0.05). CONCLUSION: User's knowledge and experience
reduce the breakage of condom.
PMID- 10685315
TI - Predictors of women's decision to ask new partners to use condoms to avoid
HIV/AIDS in South Africa.
AB - OBJECTIVES: (i) to identify the key determinants of women's decision to ask a new
partner to use condoms during sexual intercourse in order to reduce the
probability of HIV infection. (ii) to estimate the impact of social, economic and
educational factors identified above on the likelihood of a positive decision
and; (iii) to explore the policy implications of the analysis. DESIGN: Cross
sectional national household sample survey. SETTING: South African Health
Inequalities Survey, 1994. SUBJECTS OR PARTICIPANTS: Three thousand three hundred
and thirty three South African women aged between 16 and 64 years. INTERVENTIONS:
Descriptive/inferential non-intervention study. MAIN OUTCOME MEASURES:
Respondent's decision to ask one's new partner to use a condom during sexual
intercourse. RESULTS: The study revealed that condoms have a contraceptive
benefit; AIDS epidemic is spreading rapidly across South Africa; people in ones
own community are using condoms to avoid getting AIDS; and AIDS can be
transmitted by having sexual intercourse with someone without using a condom were
positive and statistically significant at p < or = 0.05. CONCLUSION: Equipping
women with above mentioned forms of knowledge would go a long way in empowering
them to exercise their rights to uncoerced choice to have safe sexual
relationships.
PMID- 10685316
TI - Pregnancy outcome in primigravidae with late onset hypertensive disease.
AB - BACKGROUND: The perinatal mortality associated with pre-eclampsia is extremely
high and it is mainly associated with early onset disease in multiparous women.
Hypertension without proteinuria in late pregnancy may not be associated with
high perinatal mortality rates. OBJECTIVE: To establish the perinatal outcome in
primigravidae women with hypertension occurring in late pregnancy, that is, at
thirty fourth week or later. DESIGN: Prospective case-control study. SETTING:
Labour ward of King Edward VIII Hospital, Durban, South Africa. PATIENTS: Three
hundred and twenty two primigravidae consisting of 161 hypertensives and 161
controls. MAIN OUTCOME MEASURES: Maternal and foetal morbidity and mortality.
RESULTS: The hypertensive group was divided into those with proteinuria (group a)
and without proteinuria (group b). The mean birthweight of babies born to
proteinuric hypertensives was significantly lower than that of hypertensives
without proteinuria and the normotensive group (2.4 kg (a) versus 2.8 kg (b)
versus 3.02 kg (c) respectively--a versus b, p = 0.0001; a versus c, p = 0.001; b
versus c, p = 0.009). There were nine perinatal deaths and all occurred in the
proteinuric hypertension group. CONCLUSION: Primigravidae with late onset
proteinuric hypertension had smaller babies and higher perinatal mortality than
their aproteinuric hypertensive and normotensive controls.
PMID- 10685317
TI - Demographic and socio-economic factors with implications for the control of
lymphatic filariasis in Kwale District, Kenya.
AB - OBJECTIVE: To examine demographic and socio-economic factors with regard to
control of lymphatic filariasis. DESIGN: A cross sectional data collection
approach using a questionnaire. SETTING: Three adjacent villages, namely
Lutsangani, Dzivani and Gandini in Kwale district. This was the study site for a
larger KEMRI-JICA lymphatic filariasis control project. Findings from the larger
project showed filariasis prevalence rates of 22.6%, 12.1% and 11.9% in the three
villages respectively. SUBJECTS: All 891 household-heads in the three villages.
MAIN OUTCOME MEASURES: Relationship between selected factors (age, sex,
education, employment status, availability of latrine and permanent roofing for
the main dwelling) and current use of protection against mosquito bites. RESULTS:
Use of mosquito-bed nets, mosquito repellents and insecticides was found in 13.8%
of the households. Education and employment status of the household-heads were
positively associated with protection against man-vector contact (p < 0.001). Non
availability of latrines and lack of permanent roofing (tiles or corrugated iron
sheets) for the main dwellings in 80% and 95% households, respectively, were
additional clear indicators of low socio-economic development. CONCLUSION: Given
the inter-village variations in the prevalence of the filariasis, wide scale
diagnosis for treatment control approach could be prohibitively expensive.
Effective control of filariasis in this and similar communities may be by mass
treatment with either diethylcarbamazine (DEC) or ivermectin combined with
albendazole.
PMID- 10685319
TI - Re: Cutaneous leishmaniasis in BALB/c mice caused by a sauroleishmania species
isolated from a plated lizard, gerrhosaurus major (squamata cordylidae)
PMID- 10685318
TI - Incarcerated and strangulated inguinal hernias in children in Zaria, Nigeria.
AB - OBJECTIVE: To reappraise the problem of incarcerated and strangulated inguinal
hernias in children in Zaria, Nigeria. DESIGN: A retrospective study. SETTING:
Ahmadu Bello University Teaching Hospital, Zaria, Nigeria. PATIENTS: Eighteen
children aged below two years with incarcerated and strangulated inguinal hernias
managed over a 10 year period. MAIN OUTCOME MEASURES: Incarceration and
strangulation rate, resection rate, testicular infarction, wound infection.
RESULTS: The overall incarceration and strangulation rate was 4.8%. The rate in
neonates was 80%, 33% in those less than six months and 21% in those below one
year. There was no incarceration or strangulations after two years of age. The
intestinal resection rate for gangrene was 11% (two neonates) and ipsilateral
orchidectomy was necessary for testicular infarction in two neonates (11%). Wound
infection occurred in three patients (17%) and there were no deaths. Overall,
there has been an improvement in the incarceration and strangulation rate,
resection rate and wound infection rate over earlier years (5.7%, 28% and 50%
respectively for earlier years) due largely to early presentation. Testicular
infarction, however, remains a major risk particularly in neonates. CONCLUSION:
The policy of early repair of inguinal hernias in children especially below two
years and particularly in neonates should be continuously emphasised to avoid
morbidity.
PMID- 10685320
TI - Correlates of psychiatric morbidity and case identification in Ibadan, Nigeria.
AB - OBJECTIVE: To determine the correlates of psychiatric morbidity and the factors
that may influence the recognition of psychiatric cases in primary care. DESIGN:
In the cross-sectional survey, the sample was selected by systematic sampling
technique. Each subject was interviewed in sequence by a research nurse, a
psychiatrist and a general practitioner (GP). SETTING: The primary care facility
at the University College Hospital, Ibadan. SUBJECTS: Eight GPs and 414 (44%
males, 56% females) patients were selected. INTERVENTION: A socio-demographic
questionnaire, the present state examination (PSE), and clinical interview were
administered to the subjects. Eysench personality questionnaire (EPQ) was
completed by GPs. The research nurses scored each GP on an enthusiasm scale. MAIN
OUTCOME MEASURES: The diagnosis by psychiatrist and GPs recorded on doctors'
information sheet: the PSE scores of subjects, the EPQ scores of GPs and their
observed enthusiasm ratings among others were the main measures. RESULTS: The
psychiatric morbidity rate was 43.4% in the centre. GPs accuracy was 0.7 and
Kappa score was 0.44. EPQ Neuroticism and Psychoticism scores correlated
negatively with GPs ability to recognise cases, whereas enthusiasm correlated
positively. GPs had difficulty in recognising minor psychiatric disorders
accounting for 94.4% of morbidity in the primary care. Morbidity was
significantly associated with female sex, age 45-54 years, self-employment, low
level of education and being currently married. Females and the self-employed
were over-represented among GPs' cases. CONCLUSION: More data from similar
studies across cultures would provide useful insight into strategies that could
bring about early recognition and treatment of minor psychiatric disorders in the
primary health care.
PMID- 10685321
TI - Nutrition in the management of acquired immunodeficiency syndrome.
AB - OBJECTIVE: To highlight the influence of nutrition on the progress of HIV/AIDS
and the role and importance of good nutrition in the management of the disease.
STUDY SELECTION: The subject was selected because it is now recognised that
nutritional care and support is an essential component of the health care plan
and management for people with HIV/AIDS. The subject is especially relevant since
few studies have been conducted locally on the effects of nutritional status on
the progression of HIV/AIDS. DATA RESOURCES AND DATA SYNTHESIS: A review of
current literature selected from local and international scientific journals and
books on the subject of nutrition and HIV/AIDS. DATA EXTRACTION AND SYNTHESIS:
Data were developed from the reviewed information extracted from the contribution
of different authors who are interested in nutritional management of people with
HIV/AIDS. It was then analysed and synthesised into the current article.
CONCLUSION: On the basis of the reviewed information, it is recommended that
individuals with HIV/AIDS be given nutrition counselling and support to enable
them achieve an adequate nutrient and energy intake for as long as possible. This
would enhance the quality of their lives and minimise disease symptoms.
PMID- 10685322
TI - Nutritional status and nutrient intake of preschool children in northern Ghana.
AB - OBJECTIVE: To determine the nutritional status and nutrient intake of preschool
children in a sub-Sahelian setting so as to ascertain whether they meet the
acceptable standards. DESIGN: Prospective/investigative study. SETTING: The study
was carried out in Saboba, a rural sub-Sahelian village in northern Ghana.
SUBJECTS: Five hundred and eighteen preschool children (2.5-6 years) drawn from
three kindergartens and five other localities were used. INTERVENTION:
Anthropometric measures of age, weight, and height were assessed. Blood and stool
samples were taken for analyses. RESULTS: The nutritional status was generally
poor, with 27% (140/519) stunted, 4.4% (23/519) wasted and 1.9% (10/519) wasted
and stunted. Majority of the children (92%) were anaemic and 16.3% had deficient
level of vitamin A (< 10 micrograms/dL). Total caloric intake was low (only 26.5%
met RDA values) and apart from protein and iron whose RDA were met by the
majority of the children (> 90%), the intake of other nutrients-calcium, vitamin
C, vitamin A and provitamin A, were low and unacceptable, compared to their
respective RDA values. In the case of iron, even though intake was adequate, the
high anaemic rate of 92% was due to high incidence of malaria (32%), hookworm
infestation, low intake of vitamin C and low bioavailability of iron from the
mainly cereal diet. CONCLUSION: The poor nutritional status of the children was
largely due to the low intake of essential nutrients.
PMID- 10685323
TI - Magnitude and determinants of bottle feeding in rural communities.
AB - BACKGROUND: Though bottle feeding is known to be hazardous either due to over
dilution of the supplement or faulty hygienic techniques during its preparation,
especially in areas where general sanitation is poor, very little attention has
been paid to it in developing countries. OBJECTIVE: To determine the extent of
bottle use in child feeding and the factors associated with its use in rural
communities. DESIGN: Community based cross-sectional study. PATIENTS: One
thousand five hundred and thirty six children, aged 0-23 months and their mothers
were included in the study. RESULTS: The overall prevalence of bottle feeding was
11.3%. Out of the 174 children who were bottle fed, only 11(6.3%) were
exclusively on it. Residence, maternal education and occupation were
significantly associated with the practice of bottle feeding in the crude
analysis and after adjusting for parental and child characteristics (p < 0.05).
CONCLUSION: The extent of bottle feeding in the studied communities is generally
high, with a higher rate among town women, a trend which was seen in the
developed world at the beginning of the century. Improvement in maternal and
child health services including education on child feeding are recommended.
PMID- 10685324
TI - Iron deficiency anaemia in children of a peri-urban health facility.
AB - OBJECTIVE: To ascertain the prevalence of iron deficiency anaemia(IDA) and its
risk factors. DESIGN: A cross-sectional survey. SETTING: A peri-urban health
centre in Nairobi, Kenya. SUBJECTS: Four hundred and three children, aged six
months to six years. INTERVENTION: Demographic data were obtained and each child
examined for signs of iron deficiency anaemia. Blood was drawn for haemoglobin
determination. MAIN OUTCOME MEASURE: The diagnosis of iron deficiency anaemia was
made using a pre-defined criteria. RESULTS: Iron deficiency anaemia had a
prevalence of 7.4% (95% CI = 4.8-10.0) and was predominantly mild (93.6%). Age
was found to be significantly associated with iron deficiency anaemia with a
prevalence of (14.6%) in infants. No association was found between IDA and sex,
birthweight, weaning age and weaning diet, sanitation, water source or mother's
education. CONCLUSION: The prevalence of iron deficiency anaemia in this health
facility was relatively low and was predominantly mild.
PMID- 10685325
TI - Serum eosinophil cationic protein as a predictor of disease activity in acute and
chronic asthma.
AB - BACKGROUND: Eosinophils may contribute to airway hyper responsiveness in asthma
through the effects of eosinophil derived granular proteins in the bronchial
epithelium. Increased concentration of eosinophil cationic protein (ECP) has been
reported in patients with acute and chronic asthma. OBJECTIVE: To examine if ECP
can serve as a marker of disease activity in acute and chronic asthma patients.
DESIGN: Prospective case control study. PATIENTS: Sixteen non smoking asthmatics
in exacerbation (group 1); twenty two in relatively stable state (group 2); and
sixteen normal control subjects (group 3) were recruited into the study. SETTING:
Casuality and outpatients departments, Mubarak hospital, Kuwait between August
1997 and July 1998. MAIN OUTCOME MEASURES: The mean serum ECP, blood eosinophil
count and peak expiratory flow rate (PEFR). RESULTS: There was a statistically
significant difference between the groups in blood eosinophil count (p < 0.01)
and in PEFR (p < 0.0001). At week four, the mean ECP and blood eosinophil count
fell as a result of therapy in group 1. The difference in PEFR values between
week 0 and 4 in group 1 reached statistical significance (p < 0.05). In group 2
patients, the mean serum ECP, blood eosinophil count and PFER values between week
0 and 4 did not show any significant difference. A correlation was observed
between ECP and PEFR in group 1 (p < 0.05) and between ECP and eosinophil count
in group 2 (p < 0.01). CONCLUSION: Serum ECP has the potential to serve as a
marker for predicting and monitoring the clinical course of asthma. Further
studies are required to verify these baseline findings in our environment.
PMID- 10685326
TI - KEMRI Hep-cell II hepatitis B surface antigen screening kit.
AB - BACKGROUND: Kenya is a high hepatitis B virus (HBV) endemic zone. Prevention of
HBV transmission by transfusing safe blood is necessary. Kits for screening
hepatitis B surface antigen (HBsAg) are usually imported and are expensive. Hence
it has been difficult to screen donated and patient blood samples all over Kenya.
OBJECTIVE: To produce a HBsAg screening kit locally in order to be able to screen
donated and patient blood samples all over Kenya. DESIGN: A laboratory based
study. SETTING: Centre for Virus Research (CVR), Kenya Medical Research Institute
(KEMRI), Nairobi. METHOD: Purified HBsAg from plasma of carriers obtained from
National Public Health Laboratories Services (NPHLS) was used to minimise guinea
pigs to produce antihepatitis B (anti HBs) antibody. The anti HBs was then used
to sensitise sheep red blood cells (SRBC). The final product was freeze dried
(lyophilised) and its sensitivity and specificity was compared with other
commercial kits. RESULTS: The sensitivity and specificity of KEMRI Hep-cell II
was found to be 98% and 99%, respectively. The kit was found to be stable and
potent for one year whether kept 4 degrees C, 37 degrees C or room temperature.
CONCLUSION: KEMRI Hep-cell II was successfully produced locally. The sensitivity
and specificity were comparable to other commercial kits. The kit was stable and
potent for one year between temperature of 4 degrees C and 37 degrees C. The kit
required only simple apparatus to carry out the test hence it can be used
anywhere in Kenya. It was also cheap and affordable.
PMID- 10685327
TI - Small bowel and mesenteric injury following traditional treatment and self
inflicted trauma to inguinal hernia.
AB - Inguinal hernia is a common indication for emergency surgery in our environment
after intestinal obstruction. Occasionally other rare indications may be seen.
Recently, two patients with such unusual presentation were managed in this
institution. One had his hernia incised, by a traditional barber with
evisceration and the other incised his hernia himself with evisceration and
laceration of the small bowel. Both patients were successfully managed. The
menace of traditional barbers and medical ignorance in tropical Africa are
reported.
PMID- 10685328
TI - Hypertrophic cardiomyopathy: case report.
AB - A case report of a 19 year old young adult male who died suddenly without any
apparent clinical cause is presented. Autopsy examination revealed hypertrophied
interventricular septum and left ventricle suggestive of a hypertrophic
cardiomyopathy (HCM). About 50% of hypertrophic cardiomyopathies are inherited as
autosomal dominant disorder, sometimes associated with neuroectodermal syndromes,
such as neurofibromatosis and pheochromocytoma. HCM is one of the common causes
of severe arrhythmias and sudden death.
PMID- 10685329
TI - Does female age affect embryo morphology?
AB - Deteriorating oocyte quality is commonly believed to be the primary determinant
of the decreased implantation potential in older women. We assessed the influence
of age on embryo morphology in standard in vitro fertilization (IVF) and
intracytoplasmic sperm injection (ICSI) modalities. All 6350 consecutive embryos
(2990 IVF, 3360 ICSI) obtained in our Assisted Reproductive Technology Unit from
January 1996 through June 1997 were included. High quality embryos were defined
as those with equal-sized blastomeres and < 10% fragmentations and a cleavage
rate of four cells on day 2 or eight cells on day 3 transfers. The results were
analyzed for the standard IVF group, the ICSI group, and the ICSI subgroup with
severe male factor infertility (< or = 1 x 10(6) total motile spermatozoa in the
ejaculate). For standard IVF, a positive association was observed between female
age and increased proportion of good quality embryos. No such association was
detected for the ICSI cycles (whole group or subgroup). We conclude that in
standard IVF, embryo quality, as reflected by embryo morphology, does not
deteriorate with increased maternal age.
PMID- 10685330
TI - Follow-up of 32 hypothalamo-hypopituitary patients treated with pulsatile
gonadotropin-releasing hormone or human menopausal gonadotropin.
AB - In a clinical retrospective study, a follow-up of hypothalamo-amenorrheic
patients treated firstly with gonadotropin-releasing hormone (GnRH) pump
stimulation and secondly with human menopausal gonadotropin (hMG) was performed.
Thirty-two hypothalamo-amenorrheic patients, 24-38 years old, were submitted to
103 GnRH stimulation cycles. Seven, with polycystic ovaries (PCO) on ultrasound,
were stimulated with hMG after one or several unsuccessful pump cycles. Ovulation
was confirmed by a luteinizing hormone (LH) surge or triggered by human chorionic
gonadotropin in 80 out of 103 cycles (77.7%/cycle) leading to 62 timed sexual
intercourses and 17 intrauterine inseminations (IUI). Twenty-one pregnancies
(26.3%/cycle) terminated in eight abortions (38.1%/pregnancy) and 13 deliveries
(40.6%/patient). hMG stimulation, in the seven PCO patients (six IVF, one IUI),
led to four additional deliveries in three patients. Five patients became
pregnant spontaneously after pump failure (n = 2) or unsuccessful IVF (n = 3).
Combining all cycles, 17 deliveries were obtained in 16 patients. No case of
ovarian hyperstimulation syndrome (OHSS) was observed. GnRH is an efficient and
safe treatment of hypothalamo-amenorrheic-induced anovulation. Following GnRH or
hMG ovarian stimulation, spontaneous ovulation and conception may be restored in
certain hypothalamo-amenorrheic patients.
PMID- 10685331
TI - Estriol add-back therapy in the long-acting gonadotropin-releasing hormone
agonist treatment of uterine leiomyomata.
AB - The hypoestrogenic state induced by gonadotropin-releasing hormone agonists
(GnRHa) has been shown to be effective in the treatment of uterine leiomyomas but
to induce bone loss. Estriol has been described to be a weak and short-acting
estrogen without an increased risk of endometrial proliferation and hyperplasia.
The purpose of this study was to evaluate whether treatment of uterine
leiomyomata with GnRHa plus oral estriol add-back therapy could prevent bone
loss, without deteriorating the therapeutic effect of GnRHa. Twelve premenopausal
women with symptomatic uterine leiomyomas were randomized to receive either
leuprolide acetate depot alone at a dose of 3.75 mg s.c. every month for 6 months
(non add-back group; n = 6), or GnRHa for 6 months plus oral estriol 4 mg/day for
4 months commencing with the third GnRHa injection (add-back group; n = 6). In
the add-back group, leiomyoma volume, as measured by transvaginal ultrasound,
decreased to 59.1% of baseline at 2 months of GnRHa therapy with no significant
change in size during the remaining treatment period. In contrast, it decreased
to 31.3% of pretreatment size at the end of treatment in the non add-back group.
The levels of bone metabolic markers such as CrossLaps, deoxypyridinoline,
osteocalcin and bone-specific alkaline phosphatase, increased significantly
throughout the treatment in the non add-back group, whereas they were suppressed
by the add-back therapy. The bone mineral density of lumbar spine (L2-L4) as
measured by dual-energy X-ray absorptiometry decreased significantly by 7.5% at
the end of treatment in the non add-back group, but did not change significantly
in the add-back group. In conclusion, GnRHa plus estriol add-back therapy might
be considered for long-term treatment of uterine leiomyomata.
PMID- 10685332
TI - Prevalence of a positive family history of type 2 diabetes in women with
polycystic ovarian disease.
AB - The known association between insulin resistance and polycystic ovarian disease
(PCOD) has been studied by determination of the prevalence of a positive family
history of diabetes in a consecutive series of oligomenorrheic women with
polycystic ovaries and eumenorrheic women with normal ovaries who served as
controls. A significantly greater proportion of the families of the patients with
PCOD had at least one member affected by type 2 diabetes (39.1% of the PCOD group
and 7.6% of the controls; p < 0.001). Both obese (54.8%) and non-obese women
(24.2%) with PCOD had an increased prevalence of type 2 diabetes within their
families. Paternal and maternal family members affected were in similar
proportions, there being no evidence of preferential transmission through the
female line in this study. The increased prevalence of type 2 diabetes in the
families of women with polycystic ovaries is further evidence for the association
between PCOD and insulin resistance, and provides a possible explanation for the
familial nature of the ovarian disorder.
PMID- 10685333
TI - Total testosterone and DHEAS levels as predictors of androgen-secreting
neoplasms: a populational study.
AB - Androgen excess affects between 2% and 10% of women. While the majority of these
patients suffer from polycystic ovary syndrome, a few present with an androgen
secreting neoplasm. An elevated circulating total testosterone level and
dehydroepiandiosterone sulfate (DHEAS) level have been proposed as screening
methods for detecting ovarian and adrenal androgen-secreting neoplasms,
respectively. To determine the predictive value of these tests for androgen
secreting tumors in a population of consecutive hyperandrogenic patients, we
studied 478 consecutive untreated hyperandrogenic patients presenting over a ten
year period (1987-97). All had at least two of the following features: (1)
oligomenorrhea (i.e. cycles > 35 days or < 8 cycles/year), (2) hyperandrogenemia
(i.e. a total or free testosterone, or DHEAS > 95th percentile of controls), or
(3) hirsutism (i.e. a modified Ferriman-Gallwey score > or = 6). None of these
patients had a prior diagnosis of an androgen-secreting neoplasm. Basal levels of
testosterone and DHEAS were determined in all patients, with transvaginal
sonography and an adrenal computed tomography scan in select individuals. Of the
478 patients included, 65% had hirsutism and oligomenorrhea; 20% had
hyperandrogenic oligomenorrhea; and 15% had hirsutism and hyperandrogenemia,
without overt oligomenorrhea. Overall, 11 (2.3%) patients had a total
testosterone > 8.7 nmol/l (250 ng/dl), of which one actually had an androgen
secreting neoplasm (i.e. true-positive). This postmenopausal patient presented
with rapidly progressive virilization, and demonstrated an ovarian hilar cell
tumor at surgery. The calculated sensitivity of an elevated testosterone level (>
8.67 nmol/l) for a neoplasm was 100% (1/1), the specificity was 98% (467/477),
and the negative predictive value was 100% (467/467), but the positive predictive
value was only 9% (1/11). Ten subjects had DHEAS levels > 16.3 mumol/l (6000
ng/ml), and none was diagnosed with an adrenocortical tumor. Although the
sensitivity and positive predictive value of a high DHEAS for a neoplasm could
not be calculated due to the absence of a test case, the specificity was 98%
(468/478) and the negative predictive value was 100% (468/468). These data
suggest that the measurement of testosterone and DHEAS is not a cost-effective
method of screening for these tumors, due to the low frequency of the disorder
and the fact that clinical evaluation alone is often sufficient screening.
PMID- 10685334
TI - LH-RH analogues: I. Their impact on reproductive medicine.
AB - In the 28 years that have passed since the elucidation of the structure of
luteinizing hormone-releasing hormone (LH-RH), diverse clinical applications in
the field of reproductive medicine and related fields have been established for
agonists of LH-RH, based on inhibition of the pituitary-gonadal axis. Various
clinical investigations with agonists of LH-RH in benign gynecologic disorders,
polycystic ovary disease (PCOD), in vitro fertilization-embryo transfer (IVF-ET),
benign prostatic hypertrophy (BPH), precocious puberty and contraception were
reviewed. LH-RH antagonists inhibit LH, follicle-stimulating hormone (FSH), and
sex steroid secretion immediately after their administration and thus achieve
rapid therapeutic effects. LH-RH antagonists should find applications in the
treatment of uterine leiomyomas, endometriosis, and in controlled ovarian
stimulation-assisted reproductive techniques (COS-ART), which have been already
established for the agonists. Modern LH-RH antagonists such as cetrorelix may
prove superior to the agonists in COS-ART and also in the treatment of BPH, but
additional studies in these and other areas are needed.
PMID- 10685335
TI - Regulation of granulosa cell proliferation and apoptosis during follicular
development.
PMID- 10685336
TI - A historical perspective of the clinical evolution of the assisted reproductive
technologies.
AB - The practice of assisted reproduction technology today is the result of the
dedicated patient care, observation, research, and experimentation undertaken by
previous generations of physicians. The building blocks of progress have been
assembled over past decades, by scientists whose primary objective has been to
push forward the frontiers of knowledge, in order to offer more effective methods
of infertility treatment. And fortunately that process continues today. Amongst
the many scientific developments that have led to the modern practice in assisted
reproductive technology, a small number stand out as having had a unique
importance. This historical review redraws the path through which in vitro
fertilization went from an experimental to an accepted infertility treatment.
PMID- 10685337
TI - Endocrine therapy for gynecological cancer.
PMID- 10685339
TI - Multiple-quantum HCN-CCH-TOCSY experiment for 13C/15N labeled RNA
oligonucleotides.
AB - A multiple-quantum 3D HCN-CCH-TOCSY experiment is presented for the assignment of
RNA ribose resonances. The experiment makes use of the chemical shift dispersion
of N1 of pyrimidine and N9 of purine to distinguish the ribose spin systems. It
provides an alternative approach for the assignment of ribose resonances to the
currently used COSY- and TOCSY-type experiments in which either 13C or 1H is
utilized to distinguish the different spin systems. Compared to the single
quantum version, the sensitivity of the multiple-quantum HCN-CCH-TOCSY experiment
is enhanced on average by a factor of 2 for a 23-mer RNA aptamer complexed with
neomycin.
PMID- 10685338
TI - Refined solution structure and backbone dynamics of 15N-labeled C12A-p8MTCP1
studied by NMR relaxation.
AB - MTCP1 (for Mature-T-Cell Proliferation) was the first gene unequivocally
identified in the group of uncommon leukemias with a mature phenotype. The three
dimensional solution structure of the human p8MTCP1 protein encoded by the MTCP1
oncogene has been previously determined by homonuclear proton two-dimensional NMR
methods at 600 MHz: it consists of an original scaffold comprising three alpha
helices, associated with a new cysteine motif. Two of the helices are covalently
paired by two disulfide bridges, forming an alpha-hairpin which resembles an
antiparallel coiled-coil. The third helix is orientated roughly parallel to the
plane defined by the alpha-antiparallel motif and appears less well defined. In
order to gain more insight into the details of this new scaffold, we uniformly
labeled with nitrogen-15 a mutant of this protein (C12A-p8MTCP1) in which the
unbound cysteine at position 12 has been replaced by an alanine residue, thus
allowing reproducibly high yields of recombinant protein. The refined structure
benefits from 211 additional NOEs, extracted from 15N-edited 3D experiments, and
from a nearly complete set of phi angular restraints allowing the estimation of
the helical content of the structured part of the protein. Moreover, measurements
of 15N spin relaxation times and heteronuclear 15N?1H?NOEs provided additional
insights into the dynamics of the protein backbone. The analysis of the linear
correlation between J(0) and J(omega) was used to interpret relaxation
parameters. It appears that the apparent relative disorder seen in helix III is
not simply due to a lack of experimental constraints, but associated with
substantial contributions of sub-nanosecond motions in this segment.
PMID- 10685340
TI - Maximum entropy approach to the determination of solution conformation of
flexible polypeptides by global conformational analysis and NMR spectroscopy-
application to DNS1-c-[D-A2,bu2,Trp4,Leu5]enkephalin and DNS1-c-[D-A2bu2,Trp4,D
Leu5]enkephalin.
AB - A method is proposed to determine the conformational equilibrium of flexible
polypeptides in solution, using the data provided by NMR spectroscopy and
theoretical conformational calculations. The algorithm consists of the following
three steps: (i) search of the conformational space in order to find
conformations with reasonably low energy; (ii) simulation of the NOE spectrum and
vicinal coupling constants for each of the low energy conformations; and (iii)
determining the statistical weights of the conformations, by means of the maximum
entropy method, in order to obtain the best fit of the averaged NOE intensities
and coupling constants to the experimental quantities. The method has been
applied to two cyclic enkephalin analogs: DNS1-c-[D-A2bu2,Trp4,Leu5]enkephalin
(ENKL) and DNS1-c-[D-A2bu2,Trp4,D-Leu5]enkephalin (ENKD). NMR measurements were
carried out in deuterated dimethyl sulfoxide. Two techniques were used in
conformational search: the electrostatically driven Monte Carlo method (EDMC),
which results in extensive search of the conformational space, but gives only
energy minima, and the molecular dynamics method (MD), which results in a more
accurate, but also more confined search. In the case of EDMC calculations,
conformational energy was evaluated using the ECEPP/3 force field augmented with
the SRFOPT solvation-shell model, while in the case of MD the AMBER force field
was used with explicit solvent molecules. Both searches and subsequent fitting of
conformational weights to NMR data resulted in similar conformations of the
cyclic part of the peptides studied. For both ENKL and ENKD a common feature of
the low-energy solution conformations is the presence of a type II' or type IV
beta-turn at residues 3 and 4; the ECEPP/3 force field also gives a remarkable
content of type III beta-turn. These beta-turns are tighter in the case of ENKL,
which is reflected in different distributions of the D-A2bu(N gamma H)...D
A2bu(CO) and D-A2bu(N gamma H)...Gly3(CO) hydrogen-bonding distances, indicating
that the D-A2bu(N gamma H) amide proton is more shielded from the solvent than in
the case of ENKD. This finding conforms with the results of temperature
coefficient data of the D-A2bu(N gamma H) proton. It has also been found that
direct (MD) or Boltzmann (EDMC) averages of the observables do not exactly
conform with the measured values, even when explicit solvent molecules are
included. This suggests that improving force-field parameters might be necessary
in order to obtain reliable conformational ensembles in computer simulations,
without the aid of experimental data.
PMID- 10685342
TI - 1H, 15N, 13C, and 13CO assignments and secondary structure determination of RGS4.
PMID- 10685341
TI - Line narrowing in spectra of proteins dissolved in a dilute liquid crystalline
phase by band-selective adiabatic decoupling: application to 1HN-15N residual
dipolar coupling measurements.
AB - Residual heteronuclear dipolar couplings obtained from partially oriented protein
samples can provide unique NMR constraints for protein structure determination.
However, partial orientation of protein samples also causes severe 1H line
broadening resulting from residual 1H-1H dipolar couplings. In this communication
we show that band-selective 1H homonuclear decoupling during data acquisition is
an efficient way to suppress residual 1H-1H dipolar couplings, resulting in
spectra that are still amenable to solution NMR analysis, even with high degrees
of alignment. As an example, we present a novel experiment with improved
sensitivity for the measurement of one-bond 1HN-15N residual dipolar couplings in
a protein sample dissolved in magnetically aligned liquid crystalline bicelles.
PMID- 10685343
TI - Backbone NMR assignment and secondary structure of ribosome recycling factor
(RRF) from Pseudomonas aeruginosa.
PMID- 10685344
TI - Sequence-specific 1H, 13C and 15N resonance assignments of recombinant onconase/P
30 protein.
PMID- 10685345
TI - 1H, 15N, and 13C NMR backbone assignments of the N-terminal region of human
erythrocyte alpha spectrin including one structural domain.
PMID- 10685346
TI - Toward progress research: closing the gap between family therapy practice and
research.
PMID- 10685347
TI - A content analysis of research in family therapy journals.
AB - In order to assess trends in family therapy research, empirical articles (N =
195) from three family therapy journals over a 5-year period were coded for
several variables: authorship, external funding, methodology, sample, purpose,
cost effectiveness, use of therapeutic model, and topic. Results indicated that a
large pecentage of research in these journals focused on nonclinical issues and
used nonclinical samples. Authors were affiliated with a wide variety of
disciplines and reported low levels of external funding for their research. While
a majority of the studies used quantitative methods, there appeared to be a
growing number of studies using qualitative methods. Implications of these
findngs are discussed in light of research reviews over the past two decades.
PMID- 10685348
TI - The use of theory in family therapy research: a content analysis of family
therapy journals.
AB - Ninety-five studies from Family Process and Journal of Marital and Family Therapy
were evaluated with regard to their use of theory. While a majority of the
articles were judged to use theory in either an explicit or an implicit manner,
42% did not appear to draw on theory in either the introductory or discussion
sections. Studies that used qualitative methods appeared to use theory more
frequently and explicitly than those using quantitative methods alone. Systems
theory was found to be the most common conceptual framework, followed by
feminism. We conclude that the link between theory and research in family therapy
needs strengthening and suggest that the role of theory in family therapy be
reexamined.
PMID- 10685349
TI - The "coming of age" of couple therapy: a decade review.
AB - This article overviews significant developments in couple therapy over the last
decade. Key trends include: (1) couple therapy becoming firmly established as the
accepted treatment of choice for couple problems, (2) the blossoming of the
science of relationships, (3) strong evidence supporting the effectiveness of
couple therapy both for relationship problems and DSM disorders, (4) greater
understanding of the ramifications of gender, (5) new respect for the diversity
of family forms, (6) increased accent on the role of emotion, (7) the influence
of postmodernism, (8) greater recognition of couple violence, and (9) the move
toward integration across models of treatment.
PMID- 10685350
TI - Qualitative evaluation of family therapy programs: a participatory approach.
AB - In this article, we provide examples of participatory qualitative evaluation
methods that can be used within family therapy training programs. These methods
can elicit useful feedback to improve programs and, at the same time, empower
trainees to become partners in the evaluation process.
PMID- 10685351
TI - Recruiting the next generation of marriage and family therapists through
undergraduate internships.
PMID- 10685352
TI - The intertwined relationship between depression and marital distress: elements of
marital therapy conductive to effective treatment outcome.
AB - Within the framework of the interpersonal view of depression, this article
examines the linkage between depression and four aspects of marital relationship:
stress, support, role expectations, and interactional dynamics. Acknowledging the
intertwined relationship between depression and marital adjustment, existing
models of martial therapy for married depressed patients are examined for the
extent to which they address these four aspects. The empirical evidence for the
efficacy of these models is also reviewed, suggesting elements of marital therapy
that are conducive to effective treatment outcome.
PMID- 10685353
TI - A randomized trial of emotion-focused therapy for couples in a training clinic.
AB - Forty married couples participated in a randomized trial comparing 8 weekly
sessions of emotion-focused therapy (EFT) for couples to a group of couples who
were placed on an 8-week waiting list. A composite marital satisfaction score was
created from scores on the Dyadic Adjustment Scale, Positive Feelings
Questionnaire, and Personal Assessment of Intimacy in Relationships scale.
Controlling for pretest scores, participants in the treatment group had
significantly higher levels of marital satisfaction after 8 weeks than wait-list
participants. Supplementary analyses identified variables associated with gains
in therapy and with dropping out of the study.
PMID- 10685354
TI - Family therapy trainees' evaluations of their best and worst supervision
experiences.
AB - Supervisees in Commission on Accreditation for Marriage and Family Therapy
Education-(COAMFTE) accredited and candidacy training programs were asked to
describe their best and worst supervision experiences in terms of the context of
training and supervision, the perceived personal attributes of the supervisor,
and specific behaviors perceived to be enacted by the supervisor during
supervision. Contextual factors such as supervision modality, frequency and
duration of supervisory contacts, and sources of supervisory data appeared to
distinguish between supervisees' perceptions of their best and worst experiences.
These experiences were further distinguished by the supervisees' perceptions
regarding the supervisor's level of interpersonal attractiveness,
trustworthiness, and expertise. Key behaviors perceived to be enacted by
supervisors during best and worst experiences clustered into several dimensions
that included creating an open supervisory environment, communication and
encouragement, attending to personal growth, and providing conceptual and
technical guidance and direction.
PMID- 10685355
TI - Promoting reconciliation through psychoeducational and therapeutic interventions.
AB - This article presents a conceptualization of reconciliation as an interpersonal
process that can mend relationships in which trust has been violated. We define
reconciliation and describe a six-step program for promoting explicit
reconciliation in couples. Psychoeducational groups of couples and couple therapy
are often the contexts for promoting reconciliation. We discuss some theoretical
support for each step, techniques used to promote progress through the step, and
differential considerations in psychoeducation and therapy.
PMID- 10685356
TI - Training issues for supervisors of marriage and family therapists working with
persons living with HIV.
AB - The purpose of this article is to address the special issues and considerations
Martial and Family Therapy (MFT) supervisors might face with the increasing
HIV/AIDS epidemic. Three primary issues will be addressed in this article. First,
the importance of educating therapists regarding various aspects of the disease
process and its transmission will be discussed, followed by educational
strategies programs might adopt. Second, we will discuss the ethical and legal
considerations that may need monitoring by supervisors and trainees. Third,
special therapeutic considerations will be provided to supervisors of therapists
working with stigmatized populations.
PMID- 10685357
TI - Milestones in periodontal research and the remaining critical issues.
AB - A significant recent development in periodontal research has been the convergence
of basic and clinical research resulting in a logarithmic increase in the rate of
progress. Scientific consensus has been reached in many areas. In most
populations, moderate to severe periodontitis affects a relatively small segment
of adults who are at high risk. The microbial etiology is accepted and the
identity of the major pathogenic bacterial species is known. The mechanisms
through which resistant individuals successfully fend off the microbial challenge
are known, and the immuno-inflammatory pathways activated by bacteria that
underlie destruction of the alveolar bone and the connective tissues of the
periodontium are reasonably well understood. The evidence shows that these
pathways are held in common by all forms of periodontitis. Therapeutic modulation
of these pathways is now possible, and new treatments based on such modulation
are now becoming available. Although bacteria are essential for disease to occur,
they are insufficient; a susceptible host is also necessary. Host susceptibility,
disease progression and response to treatment are determined predominantly by
heredity and environmental and acquired risk factors. Some of these can be
changed while others are immutable. Concepts and procedures for treatment are
generally scientifically based and appropriately applied. Preventive measures are
largely successful and widely practiced in industrialized countries. Clearly,
control of these ancient chronic diseases is now within our reach. In spite of
the tremendous progress, many unresolved issues remain. The purpose of this paper
is to summarize some of the major accomplishments of periodontal research, and
identify and discuss some of the more important critical issues that still need
to be addressed.
PMID- 10685358
TI - Association of periodontal infections with atherosclerotic and pulmonary
diseases.
AB - Chronic infections may influence the severity and/or course of a number of
systemic diseases. Periodontal diseases are localized chronic inflammatory
conditions of the gingiva and underlying bone and connective tissues induced by
bacteria and bacterial products of dental plaque. This paper will discuss the
evidence for the role of periodontal disease in the pathogenesis of 2 important
systemic diseases, atherosclerosis and pulmonary infections. Both epidemiological
and laboratory studies are reviewed to assess the biological basis for the
association of periodontal infections and these important diseases. Several
potential mechanisms by which periodontal diseases may influence these conditions
are also discussed.
PMID- 10685359
TI - Periodontitis-atherosclerosis syndrome: an expanded model of pathogenesis.
AB - The early reports of a linkage between periodontitis and atherosclerosis have
garnered further support by additional data generated by several investigative
teams in many different countries. The evidence continues to suggest that
periodontitis may be an important risk factor or risk indicator for
cardiovascular pathology for some individuals. The term periodontitis
atherosclerosis syndrome (PAS) is proposed as a new diagnostic term to describe
this condition in these individuals. Current evidence, albeit preliminary in
nature, which describes a cluster of clinical signs and symptoms that are
associated with this condition, is presented. It is clear that this syndrome will
require considerable study and refinement before a definitive diagnosis and
treatment plan can be formulated. Potential mechanisms by which systemic
inflammation and infectious challenge of periodontal origin may serve as a
potential modifier of cardiovascular disease are discussed in the context of a
detailed working model of pathogenesis. This hypothetical model embraces many
cellular and molecular components of atherogenesis and thromboembolic diseases
from the perspective of periodontitis pathogenesis. Many aspects of the
hypothetical model remain unproved; however, it is our opinion that only through
the clarification of the mechanisms of pathogenesis can we ultimately construct a
knowledge framework for accurate diagnoses and successful therapies. The concept
of diagnosing and treating a periodontal patient to minimize the deleterious
effects of this chronic infectious and inflammatory condition on the
cardiovascular system represents an unprecedented challenge to our profession.
PMID- 10685360
TI - Interleukin-1 genotypes and the association between periodontitis and
cardiovascular disease.
AB - An epidemiological association between periodontitis and cardiovascular disease
has been reported in multiple studies. Various mechanisms have been proposed as
potential explanations for this association, including a common factor that
predisposes certain individuals to a hyper-responsive inflammatory response.
Variations in the genes that regulate the interleukin-1 (IL-1) response have been
associated with both periodontal disease and cardiovascular disease. New data
indicate that one pattern of IL-1 genetic polymorphisms, characterized by the IL
1A (+4845) and IL-1B (+3954) markers, is associated with periodontitis but not
certain measures of atherosclerosis. Another IL-1 genetic pattern, characterized
by the IL-1B (-511) and IL-1RN (+2018) markers, is associated with
atherosclerotic plaque formation, as measured by angiography and arterial wall
thickness, but not periodontitis. These two patterns also have different
functional implications relative to IL-1 biological activity. Studies of IL-1
gene polymorphisms, atherosclerotic plaque instability and cardiovascular
clinical events are in progress. Hypothetical models are presented to explain how
IL-1 genetic factors may be involved in cardiovascular disease.
PMID- 10685361
TI - Systemic manifestations of periodontitis in the non-human primate.
AB - This report describes our findings regarding the potential contribution of
periodontitis to atherosclerotic processes using a nonhuman primate model. The
goal of the investigations was to target general mechanisms which could describe
the association of these disease processes, including: (i) systemic translocation
of bacteria/products during periodontitis; (ii) alterations in systemic
inflammatory biomarkers during periodontitis; and (iii) the relationship of
periodontitis to serum lipids/lipoproteins. Increases in serum endotoxin (e.g.
LPS) during ligature-induced periodontitis were observed in these animals. We
determined serum levels of various acute phase reactants and chemokines (e.g.
CRP, alpha 1-antitrypsin, haptoglobin, fibrinogen, IL-8). A number of these host
factors were significantly increased during gingivitis and/or periodontitis.
Finally, we observed specific changes in serum lipid levels (cholesterol,
triglycerides, HDL, LDL) and lipoproteins (apoA-I) during periodontitis, which
were exacerbated by exposure of the animals to a diet with elevated fat content.
Thus, we have described systemic manifestations of periodontitis that include
detection of bacterial products, inflammatory biomarkers, and dyslipoproteinemia
consistent with an increased atherogenic risk.
PMID- 10685362
TI - Potential mechanisms of susceptibility to periodontitis in tobacco smokers.
AB - Tobacco smoking is probably the most important, controllable environmental risk
factor in periodontitis. It results in changes in the vascular, inflammatory,
immune and healing responses. The degree of exposure to tobacco smoking can be
measured in pack years or by measuring serum cotinine and nicotine levels. In a
previous paper we reported elevated levels of serum soluble intercellular
adhesion molecule-1 (sICAM-1) in smokers, regardless of periodontal status.
Elevated sICAM-1 has been found to be a risk marker for cardiovascular disease.
In the present paper we report the short-term effects of an episode of smoking on
blood flow and levels of sICAM-1. Human volunteers included non-smokers, light
smokers and heavy smokers. Relative blood flow was monitored in the gingivae and
forehead skin using a laser Doppler flowmeter and serum levels of sICAM-1,
cotinine and nicotine measured before during and up to 60 min following an
episode of smoking. We could not provide evidence to support the theory that
there is localized vasoconstriction within the gingival tissues. In contrast,
there was a significant increase in blood flow in the forehead skin of light
smokers which was not observed in non-smoking controls or in heavy smokers,
suggesting a long-term tolerance in this latter group. The level of sICAM-1
remained unchanged during this episode, further suggesting a long-term effect. In
a parallel group of subjects, we were able to demonstrate a direct significant
correlation between sICAM and serum cotinine levels. These observations may be
relevant to aetiological mechanisms in periodontitis and other smoking-associated
diseases.
PMID- 10685363
TI - Lipoxin A4 and aspirin-triggered 15-epi-LXA4 inhibit tumor necrosis factor-alpha
initiated neutrophil responses and trafficking: novel regulators of a cytokine
chemokine axis relevant to periodontal diseases.
AB - The impact of lipoxin A4 (LXA4) and aspirin-triggered-lipoxins (ATL) was
investigated in tumor necrosis factor (TNF alpha)-initiated neutrophil (PMN)
responses in vitro and in vivo using LX analogs that are metabolically more
stable. At nanomolar levels, the LXA4 and ATL analog 15 R/S-methyl-LXA4 each
blocked TNF alpha-stimulated IL-1 beta release by isolated human PMN in vitro.
These LXA4-ATL actions were time- and concentration-dependent. The TNF alpha
induced IL-1 beta gene expression was also regulated by 15 R/S-methyl-LXA4. In
addition, 15 R/S-methyl-LXA4 added to murine air pouches dramatically inhibited
TNF alpha-stimulated leukocyte trafficking in vivo, as well as altered the
appearance of both macrophage inflammatory peptide-2 and IL-1 beta and
concomitantly stimulated IL-4 in pouch exudates. These findings from in vitro and
in vivo experiments indicate that both LXA4 and ATL are regulators of TNF alpha
directed neutrophil actions and stimulate IL-4 in exudates and thus regulate
mediators that are held to play an important role in the pathogenesis of
periodontal disease.
PMID- 10685364
TI - HLA genetics for diagnosis of susceptibility to early-onset periodontitis.
AB - Human leukocyte antigens (HLA) are essential in the recognition of foreign
antigens in humoral immune response, which is genetically predetermined.
Susceptibility to certain diseases that involve the immune response has been
studied in relation to distinct HLA types. Although some diseases have been found
to correlate to specific HLA loci positively, it has been difficult to isolate
HLA types that predispose patients to periodontal destruction. Here, we review
the current knowledge and recent advances in HLA genetics and its biology, which
determine susceptibility to early-onset periodontitis (EOP). The HLA-DRB1*1501
DQB1*0602 genotype has been found with increasing frequency in EOP patients. This
HLA genotype expresses aspartic acid at position 57 and glycine at position 70 on
the DQ beta chain, suggesting a capability to bind certain bacterial antigens.
The T cell response against the outer membrane protein (Ag53) of Porphyromonas
gingivalis was examined via this HLA genotype. Strong T cell response against
Ag53 p141-161 was inhibited partially by anti-DR antibody, but not by anti-DQ
antibody. Possible host and bacterial peptides capable of binding DRB1*1501 were
elucidated when the peptide sequence was compared to gene and protein databases.
These results suggest that patients who have the HLA-DRB1*1501-DQB1*0602 genotype
may have an accelerated T cell response to certain periodontopathic bacteria such
as P. gingivalis in hyperimmune reactions and thus increased susceptibility to
EOP.
PMID- 10685365
TI - Analysis of genetic polymorphisms at the interleukin-10 and tumour necrosis
factor loci in early-onset periodontitis.
AB - Early onset periodontitis (EOP) is considered to have a substantial genetic
basis, although the gene or genes involved have not been elucidated. The aim of
the present study was to investigate possible links between generalized EOP
(GEOP) and genes regulating expression of the cytokines tumour necrosis factor
(TNF) and interleukin-10 (IL-10). Microsatellite marker DNA sequences
corresponding to phenotypic variations in cytokine response were analysed.
Genotypic variations in cytokine response have been shown in vitro for TNF and IL
10, and specific alleles are implicated in diseases such as systemic lupus
erythmatosus (SLE) and rheumatoid arthritis (RA). Two microsatellites at the IL
10 locus, IL10.R and IL10.G, and 1 microsatellite at the TNF locus, TNFa, were
typed for 77 GEOP patients in the West of Scotland. Due to the highly polymorphic
nature of the microsatellite loci, a statistical comparison with ethnically
matched healthy controls (TNFa, n = 91, IL10.R, n = 94, IL10.G, n = 102) was
conducted using a Monte Carlo simulation for each marker. No significant
differences were observed for any of the 3 markers, although there were possible
indications of trends similar to those observed in SLE for the IL10.G marker. In
conclusion, no links were found between GEOP and microsatellites at TNFa, IL10.R
or IL10.G loci.
PMID- 10685366
TI - Staphylococcus aureus-induced inflammation and bone destruction in experimental
models of septic arthritis.
AB - Staphylococcus aureus is the most common cause of septic arthritis. This disease
often leads to severe joint destruction and high mortality. An experimental model
of S. aureus arthritis has been developed to study the course of inflammation and
joint destruction, to elucidate the role of bacterial and host factors for joint
pathology and mortality, and to develop therapeutical and preventive devices
against septic arthritis and sepsis. Results show that the innate immune system
is crucial in defending the host against staphylococcal infection while
components of the specific immune system, T and B lymphocytes and their products,
are detrimental to the host, mediating joint destruction and increasing mortality
rates. Staphylococcal capsule polysaccharides, toxins, cell wall-attached
adhesins and possibly also the chromosomal DNA are virulence determinants in S.
aureus arthritis. Several vaccine candidates have recently been described which
protects against staphylococcal infections, e.g. staphylococcal surface
polysaccharides, enterotoxins devoid of their superantigenic properties and
collagen adhesin. There are also new approaches suggested for treatment of
ongoing infections, such as the combined use of antibiotics and corticosteroids.
PMID- 10685367
TI - Porphyromonas gingivalis virulence factors and invasion of cells of the
cardiovascular system.
AB - Our laboratory is interested in the genes and gene products involved in the
interactions between Porphyromonas gingivalis (Pg) and the host. These
interactions may occur in either the periodontal tissues or other non-oral host
tissues such as those of the cardiovascular system. We have previously reported
the cloning of several genes encoding hemagglutinins, surface proteins that
interact with the host tissues, and are investigating their roles in the disease
process. Primary among these is HagA, a very large protein with multiple
functional groups that have significant sequence homology to protease genes of
this species. Preliminary evidence indicates that an avirulent Salmonella
typhimurium strain containing hagA is virulent in mice. These data indicate that
HagA may be a key virulence factor of Pg. Additionally, we are investigating the
invasion of primary human coronary artery endothelial cells (HCAEC) by Pg because
of the recent epidemiological studies indicating a correlation between
periodontal disease (PD) and coronary heart disease (CHD). We found that some,
but not all, strains of Pg are able to invade these cells. Scanning electron
microsopy of the infected HCAEC demonstrated that the invading organisms
initially attached to the host cell surface as aggregates and by a "pedestal"
like structure. By transmission electronmicroscopy it could be seen that
internalized bacteria were present within multimembranous compartments localized
with rough endoplasmic reticulum. In addition, invasion of the HCAEC by Pg
resulted in an increase in the degradation of long-lived cellular proteins. These
data indicate that Pg are present within autophagosomes and may use components of
the autophagic pathway as a means to survive intracellularly. However, Pg
presence within autophagosomes in KB cells could not be observed or detected. It
is therefore likely that Pg uses different invasive mechanisms for different host
cells. This and the role of HagA in invasion is currently being investigated
further.
PMID- 10685368
TI - The rag locus of Porphyromonas gingivalis: a novel pathogenicity island.
AB - Previous studies in our laboratories of the serum IgG antibody response of
periodontal patients have demonstrated the presence of an immunodominant surface
antigen (Mr 55 kDa) in the outer membrane of Porphyromonas gingivalis W50.
Genetic analysis of this antigen revealed that the corresponding gene forms part
of a small operon which may have arisen via horizontal gene transfer into the
genome of this strain. On the basis of sequence homology, the 55 kDa antigen
(RagB) and the product of a cotranscribed gene (RagA) may act in concert at the
surface of the bacterium to facilitate active transport, mediated through the
periplasmic spanning protein, TonB, or form part of a signal transduction system
in this organism. The rag locus is present in only a proportion of P. gingivalis
laboratory strains and clinical isolates. Analysis of the distribution of ragB in
subgingival samples by PCR demonstrated that rag+ P. gingivalis are more
frequently detected in deep periodontal pockets than shallow sites in periodontal
patients. These findings indicate that the rag genes may influence the virulence
potential of P. gingivalis strains which harbour this locus and may thus be
considered a novel pathogenicity island. Furthermore, horizontal gene transfer
between organisms in subgingival plaque may represent a significant force in the
evolution of these bacteria with ramifications for both diagnosis and targeted
treatment of periodontal disease.
PMID- 10685369
TI - Evidence and a novel hypothesis for the role of dendritic cells and Porphyromonas
gingivalis in adult periodontitis.
AB - We have proposed a novel overall hypothesis and approach to understanding the
pathophysiology of adult periodontitis, one of the most common diseases that
afflicts the US population. While mortality of the dentition is the most familiar
outcome of adult periodontitis, its links with other more severe diseases,
including coronary artery disease, respiratory diseases and pre-term labor,
cannot be ignored. We have called attention to the many intriguing parallels
between adult periodontitis and contact hypersensitivity (CHS). CHS is among the
most common of dermatoses that afflicts mankind and one of the most intensively
studied of in vivo immune responses. Both adult periodontitis and CHS target the
host integument (gingiva or skin) and appear to involve the activation and
sensitization of similar subsets of antigen capture and presenting cells, the
dendritic cells (DCs), as well as similar T cell subsets. DCs have been termed
"nature's adjuvant", being more efficient at antigen-presentation than
macrophages or B cells and the only antigen-presenting cells that can stimulate
naive T cells to proliferate. This immunostimulatory capacity can also have
detrimental effects for the host, as typified by graft-vs.-host disease and CHS
responses. Both AP and CHS involve a predominantly destructive T cell response
mediated by both regulatory and effector T cells. In the present paper, we show
intriguing evidence that Porphyromonas gingivalis is a unique pathogen in this
regard, able to infect, sensitize and activate DCs in vitro and, probably, in
situ. Many questions about the role of P. gingivalis-sensitized DCs in adult
periodontitis, and of the parallels between adult periodontitis and CHS, however,
remain to be answered.
PMID- 10685370
TI - Controlled delivery of inductive proteins, plasmid DNA and cells from tissue
engineering matrices.
AB - It has been estimated that half the annual health care budget in the United
States is spent on patients suffering from tissue loss and late stage organ
failure. Critical limitations inherent in traditional therapies call for novel
tissue and organ replacement strategies. This paper discusses development of
biomaterials for conductive, inductive and cell-based tissue replacement
strategies. Biodegradable polymer scaffolds can be used as space-filling matrices
for tissue development and barriers to migration of epithelial cells in tissue
conductive approaches. Inductive approaches involve sustained delivery of
bioactive factors, such as protein growth factors and DNA, to alter cell function
in localized regions. Factors can be released from highly porous polymer
scaffolds to allow factor delivery and tissue development to occur in concert.
Cell-based approaches involve seeding of cells onto polymeric scaffolds in vitro
and subsequent transplantation of the scaffold. New scaffold materials are being
developed that address specific tissue engineering design requirements, and in
some cases attempt to mimic natural extracellular matrices. These strategies
together offer the possibility of predictably forming specific tissue structures,
and may provide solutions to problems such as periodontal ligament detachment,
alveolar bone resorption and furcation defects.
PMID- 10685371
TI - Evolution of periodontal regeneration: from the roots' point of view.
AB - Tissues lost as a consequence of periodontal diseases, i.e. bone, cementum and a
functional periodontal ligament (PDL), can be restored to some degree.
Nevertheless, results are often disappointing. There is a need to develop new
paradigms for regenerating periodontal tissues that are based on an understanding
of the cellular and molecular mechanisms regulating the development and
regeneration of periodontal tissues. As one approach we have developed strategies
for maintaining cementoblasts in culture by first determining the gene profile
for these cells in situ. Next, cells were immortalized in vitro using SV 40 large
T antigen (SV40 Tag) or by using mice containing transgenes enabling cellular
immortality in vitro. Cementoblasts in vitro retained expression of genes
associated with mineralized tissues, bone sialoprotein and osteocalcin, that were
not linked with periodontal fibroblasts either in situ or in vitro. Further,
cementoblasts promoted mineralization in vitro as measured by von Kossa and ex
vivo using a severely compromised immunodeficient (SCID) mouse model. These cells
responded to growth factors by eliciting changes in gene profile and mitogenesis
and to osteotropic hormones by evoking changes in gene profile and ability to
induce mineral nodule formation in vitro. The ultimate goal of these studies is
to provide the knowledge base required for designing improved modalities for use
in periodontal regenerative therapies.
PMID- 10685372
TI - Regeneration of periodontal tissues by basic fibroblast growth factor.
AB - Several growth factors (or cytokines) have recently received attention because of
their ability to actively regulate various cellular functions of periodontal
ligament (PDL) cells and the effects of topical application of such factor(s) on
periodontal tissue regeneration has been evaluated. In this study, we examined
the role of basic fibroblast growth factor (bFGF) in the wound healing and
regeneration of periodontal tissues. Alveolar bone defects (such as 2-wall, 3
wall and furcation class II bone defects) were created surgically in beagle dogs
and primates. Recombinant bFGF was topically applied to the artificial bony
defects. Six or 8 wk after application, the periodontal regeneration was
morphologically and histomorphometrically analyzed. In all sites where bFGF was
applied, significant periodontal ligament formation with new cementum deposits
and new bone formation was observed in amounts greater than in the control sites.
We found it noteworthy that no instances of epithelial down growth, ankylosis or
root resorption were observed in the bFGF sites. In vitro studies demonstrated
that bFGF enhances the proliferative responses of human PDL cells, which express
FGF receptor-1 and -2, but inhibits the induction of alkaline phosphatase
activity and mineralized nodule formation by PDL cells. Interestingly, we
observed that the mRNA level of laminin in PDL cells, which plays an important
role in angiogenesis, was specifically upregulated by bFGF stimulation, but that
of type I collagen was downregulated. The present study demonstrates that bFGF
can be applied as one of the therapeutic modalities which actively induce
periodontal tissue regeneration. The results of in vitro studies suggest that by
suppressing the cytodifferentiation of PDL cells into mineralized tissue forming
cells, bFGF may play important roles in wound healing by promoting angiogenesis
and inducing the growth of immature PDL cells, and may in turn accelerate
periodontal regeneration.
PMID- 10685374
TI - Initial results from the European Network of Health Promoting Schools program on
development of health education in Finland.
AB - The European Network of Health Promoting School (ENHPS) program aims to foster
healthy lifestyles for school populations by developing supportive teaching and
learning environments conducive to promotion of health. Most European countries
have joined the network since its organization in 1993. This paper describes how
the European, national, and local aims of the ENHPS program have been realized in
Finnish schools during the first year of the second triennium (1997-1999).
Substantial development related to health promotion has occurred in the Finnish
ENHPS schools. A safe school environment was emphasized, and networking with
other schools was encouraged at the international and national levels. Attitudes
toward the ENHPS program generally were positive. However, Finnish schools have
emphasized developing "structures" for health promotion. In the future, efforts
should concentrate on students' active participation in the activities of health
promotion in everyday teaching and learning situations.
PMID- 10685373
TI - Effect of prostaglandin E2 on recombinant human bone morphogenetic protein-2
stimulated osteoblastic differentiation in human periodontal ligament cells.
AB - Recombinant human (rh) bone morphogenetic protein-2 (BMP-2) stimulates
osteoblastic differentiation in cells isolated from human periodontal ligament
(HPLC), and this action of rhBMP-2 may be modulated by prostaglandins (PGs),
which are local regulatory factors in the bone metabolism. In the present study,
we investigated the effect of prostaglandin E2 (PGE2) on rhBMP-2-stimulated
osteoblastic differentiation in cultured HPLC. rhBMP-2 (500 ng/ml)-stimulated
alkaline phosphatase (ALPase) activity was enhanced by simultaneous treatment
with low concentrations (10(-10)-10(-8) M) of PGE2, whereas a high concentration
(10(-6) M) of PGE2 suppressed it. rhBMP-2 did not induce cyclo-oxygenase-2 (COX
2) mRNA expression or subsequent PGE2 production, whereas it remarkably
suppressed rhIL-1 beta-induced COX-2 mRNA expression and PGE2 production. The
rhBMP-2 action on osteoblastic differentiation in HPLC was also enhanced by co
treatment with 0.25 to 25 ng/ml of rh interleukin-1 beta (IL-1 beta). The ALPase
activity stimulated by simultaneous treatment with rhBMP-2 and rhIL-1 beta was
partially inhibited by addition of 10(-6) M of indomethacin, which completely
inhibited rhIL-1 beta-induced PGE2 production. These results reveal that PGE2 at
different concentrations exerts a biphasic effect on BMP-2-stimulated
osteoblastic differentiation in HPLC, BMP-2 inhibits IL-1 beta-induced PGE2
production through suppressing COX-2 expression, and the BMP-2-stimulated
osteoblastic differentiation may be enhanced by the endogenous PGE2 induced by
BMP-2 and IL-1 beta. These suggest that BMP-2 action on osteoblastic
differentiation in HPLC may be modulated by PGE2 in autocrine and paracrine
fashions.
PMID- 10685375
TI - Identifying the educational implications of chronic illness in school children.
AB - Children and adolescents with chronic illness such as asthma, diabetes, and
cancer are at the intersection of the health and education systems. At school,
their health needs may be attended to by a school nurse, while their educational
needs may be overlooked. This article helps school personnel become more
proactive in identifying the educational implications of chronic illness in
school children. The confusing array of terms used to refer to this population by
health professionals and educators are clarified, and estimates of the size of
the population are provided. The potential impact of some common disease
processes, treatments, and medications are reviewed, as are the risks of chronic
absenteeism. Suggestions for how school and health professionals can identify and
work with this group of children are offered.
PMID- 10685376
TI - Age of first use of cigarettes among rural and small town elementary school
children in Illinois.
AB - This study determined age of first use of cigarettes among rural and small town
elementary school students. Data were collected from 1,950 elementary school
students, grades kindergarten through sixth, attending seven different schools in
southern Illinois. Bivariate odds ratios and multivariate logistic regression
procedures identified risk factors of cigarette use among this elementary school
population. A Duncan multiple-range test revealed no significant difference in
cigarette use between grades kindergarten through fifth (average percentage of
use for those grades was 4.7%), but use increased significantly to 17.4% in the
sixth grade. Predictor variables with the greatest odds ratios were having tried
alcohol (OR = 8), having tried chewing tobacco or snuff (OR = 4.4), and being in
the sixth grade (OR = 2.2). Healthy People 2010 draft objectives emphasize
prevention and reduction of tobacco use among youth. To be effective, tobacco
prevention programs must begin in the elementary school years.
PMID- 10685377
TI - Outcomes from a school-based nutrition education program alternating special
resource teachers and classroom teachers.
AB - This study modified a successful nutrition program to improve its transferability
and potential for institutionalization. Specific aims were to determine: 1) if 16
nutrition lessons taught alternately by special resource teachers (SRT) and
classroom teachers, could produce outcomes equivalent to 24 SRT lessons; and 2)
teachers' reactions to the program. The quasi-experimental design used classrooms
(19 treatment and 19 comparison) in matched schools. Surveys and plate waste
measured children's outcomes, and classroom teachers were observed and
interviewed. Treatment students showed greater knowledge and self-efficacy scores
and consumed 0.36 more servings of fruits and vegetables at lunch. Behavioral
differences between groups were greater when SRTs provided all instruction.
Teachers supported the program and anticipated teaching more nutrition on their
own, but noted serious structural barriers. Findings support the need for long
term contact to induce behavior change and the advantage of using teachers
specifically trained in nutrition and experiential education.
PMID- 10685378
TI - Epidemiology of school injuries in Utah: a population-based study.
PMID- 10685379
TI - Indications for a home standing program for individuals with spinal cord injury.
AB - Additional analyses were conducted on a recently published survey of persons with
spinal cord injury (SCI) who used standing mobility devices. Frequency and
duration of standing were examined in relation to outcomes using chi square
analyses. Respondents (n = 99) who stood 30 minutes or more per day had
significantly improved quality of life, fewer bed sores, fewer bladder
infections, improved bowel regularity, and improved ability to straighten their
legs compared with those who stood less time. Compliance with regular home
standing (at least once per week) was high (74%). The data also suggest that
individuals with SCI could benefit from standing even if they were to begin
several years after injury. The observation of patient benefits and high
compliance rates suggest that mobile standing devices should be more strongly
considered as a major intervention for relief from secondary medical
complications and improvement in overall quality of life of individuals with SCI.
PMID- 10685381
TI - Preliminary electrophysiological characterization of functionally vestigial
muscles of the head: potential for command signaling.
AB - In devastating neurological disorders, such as quadriplegia resulting from high
level spinal cord injury, it is essential to focus on functions that have been
spared and optimally exploit them to enhance the individual's quality of life. It
follows that certain muscles, which prior to the paralysis of much of the rest of
the body seemed to have no useful function, might be used to provide unique
signals to control assistive devices. This report presents preliminary
electrophysiological data demonstrating potentially useful myoelectrical signals
from 3 functionally vestigial muscles in humans; the posterior, anterior, and
superior auricular muscles. In phylogenetically lower species, these muscles
serve to position the ear to enhance hearing. The auricular muscles receive their
major innervation from cranial nerve VII and should not be compromised by even
high-level spinal cord lesions. In this study, it was found that the muscles
could be voluntarily activated and, by standard surface-electrode recording, had
potentials ranging to 680 microV in amplitude. Posterior auricular muscle
potentials were used to command a paddle in a computer ping-pong task that
employed a CyberLink interface. The t values for accuracy scores and ball hits
were both significant at the p = .0001 level. These facts indicate that the
auricular muscles may be useful for controlling assistive devices.
PMID- 10685380
TI - A comparison of FES with KAFO for providing ambulation and upright mobility in a
child with a complete thoracic spinal cord injury.
AB - This study compared functional and physiologic measures of ambulation and upright
mobility with functional electrical stimulation (FES) versus knee-ankle-foot
orthoses (KAFO) in an 11-year-old boy with a T-10 level spinal cord injury. The
child was a limited community ambulator with bilateral KAFO and loftstrand
crutches. The FES system consisted of percutaneous intramuscular electrodes
controlled by a portable stimulator and thumbswitch, an AFO for ankle and foot
support, and loftstrand crutches. The subject used a swing-through gait pattern
with both modes of mobility. The Functional Independence Measure scoring system
and time to completion were used to compare performance in 6 standardized
activities: donning, high transfer, inaccessible toilet transfer, ascend/descend
stairs, and floor-to-standing transfer. Ten repeated measures were performed for
each mode. Physiologic measures included energy expenditure, postural stability
using forceplates, and a Functional Standing Test (FST). The subject performed
all 6 mobility activities independently with FES and KAFO. In 4 of 6 activities,
there was a trend toward faster times with FES, but this was not statistically
significant. Toilet transfers and stair descent were performed significantly
faster with KAFO. There was no difference in completion times on the activities
of the FST. Measures of postural sway suggested that the subject was more stable
with KAFO during quiet standing, while the modes were equal during a dynamic
activity (raising arm for functional use). Energy expenditure results revealed no
significant difference in oxygen cost per meter but a significantly higher oxygen
consumption rate per minute for FES. Ambulation with both modes was performed at
levels consistent with strenuous exercise. Maximum ambulation distances were
relatively equal while the subject's velocity was significantly faster with FES.
Of note, the subject reported ceasing ambulation during maximum distance trials
due to general fatigue when using FES and due to shoulder pain with KAFO
ambulation. For this subject, FES provided a means of performing upright mobility
tasks independently, comparable with that of KAFO, while providing a faster
ambulation velocity and a potential means of cardiovascular training.
PMID- 10685382
TI - Surgical treatment of posttraumatic cystic and tethered spinal cords.
AB - Posttraumatic syringomyelia as a cause of progressive neurologic deterioration
has been well described. More recently, the noncystic posttraumatic tethered cord
has been associated with identical progressive neurologic deterioration. A
retrospective analysis of patients treated surgically with spinal cord
untethering and/or cyst shunting to arrest a progressive myelopathy from a
posttraumatic tethered and/or cystic cord was performed. Emphasis was on outcome
using the American Spinal Injury Association (ASIA) sensory and motor scoring
systems. During an 18-month period from May 1993 to December 1994, 70 patients
with spinal cord injury were operated upon for tethered and/or cystic spinal
cords because of a progressive myelopathy and deteriorating ASIA sensory/motor
scores. Fifty-nine patients had follow-up data 1 year postoperatively. At the 1
year follow-up, there was small improvement in light touch sensory scores (0.67
points), pinprick scores (1.3 points), and motor scores (0.41 points)
demonstrating that the progression of the myelopathic process was arrested.
Thirty-four of these 59 patients had no previous surgery to their spinal cords.
At 1 year follow-up, light touch scores improved on average 2.38 points, pinprick
scores 3.88 points (p < 0.05), and motor scores 1.47 points, suggesting better
outcome with first-time surgery. Of this latter group, 64.3% regained a lost
function, 62.5% saw improvement in spasticity, 55.6% had substantial improvement
in neurogenic pain, and 95.8% felt that surgery prevented further neurologic
deterioration.
PMID- 10685383
TI - Prevention of venous thromboembolism in patients with spinal cord injury: effects
of sequential pneumatic compression and heparin.
AB - OBJECTIVE: To estimate the incidence of and risk factors for venous
thromboembolism in patients with acute traumatic spinal cord injury (SCI) and
evaluate the effectiveness of sequential pneumatic compression devices (SCD),
gradient elastic stockings (GES), and heparin in preventing thromboembolism.
DESIGN: Prentice's case-cohort design. SETTING: All patients admitted to our
hospital between 1976 and 1995 with acute traumatic SCI. MAIN OUTCOME MEASURES:
Demographic characteristics, venous thromboembolism risk factors, methods of
surveillance and prophylaxis, and thromboembolic events during the first 6 weeks
following injury. RESULTS: Venous thromboembolism occurred in 84 of 428 patients
(19.6%). Venous thromboembolism increased from 21% between 1976 and 1979 to 31%
between 1980 and 1984, then decreased to 16% between 1985 and 1989 and to 8%
between 1990 and 1995. Routine surveillance for venous thromboembolism increased
through 1983, and SCD/GES use increased after 1983, with a concurrent decline in
incidence of thromboembolism. Multivariate analysis showed that SCD/GES reduced
the risk of deep venous thrombosis (DVT) or pulmonary embolism (relative risk,
0.5; 95% CI, 0.28 to 0.90). Multivariate analysis suggested a reduced risk of DVT
in patients receiving heparin therapy within the first 14 to 42 days after
injury, but estimates of reduced risk were not statistically significant (p =
.064 for first 14 days, p = .13 for heparin anytime). CONCLUSION: The SCD/GES
combination and heparin are each effective in preventing venous thromboembolism
in individuals' acute traumatic SCI. Effectiveness of heparin prophylaxis may be
greatest during the first 14 days after injury, whereas benefit from SCD
continues to 6 weeks after injury.
PMID- 10685384
TI - Effect of oral ciprofloxacin on bacterial flora of perineum, urethra, and lower
urinary tract in men with spinal cord injury.
AB - A study was performed in 25 men with spinal cord injuries undergoing intermittent
catheterization whose urine had > or = 10(5) bacterial colonies/ml to determine
efficacy of ciprofloxacin in eradicating susceptible organisms from urine,
urethra, and perineum. Cultures were obtained prior to, during, and 5 to 7 days
after administration of 500 mg twice daily for 10 days. Organisms in urine were
also present in the urethra and/or perineum in 20 cases. Susceptible bacteria
disappeared from urine in all subjects; but at follow-up 12 had cultures positive
for ciprofloxacin-resistant Gram-positive cocci, including 1 with methicillin
resistant Staphylococcus aureus (MRSA), and 2 with ciprofloxacin-resistant
Acinetobacter sp. Treatment significantly reduced Gram-negative bacilli in
perinea and urethras, but ciprofloxacin-susceptible organisms were replaced by
resistant staphylococci, including MRSA, enterococci, and Acinetobacter sp. We
support use of ciprofloxacin for treatment of urinary tract infections in persons
with spinal cord injury, but in view of supercolonization with resistant
organisms, the drug should be reserved for symptomatic persons not likely to
respond to other oral agents.
PMID- 10685385
TI - Treatment alternatives for spinal cord injury related spasticity.
AB - Spasticity is a disorder of the motor system that occurs after injury to the
central nervous system, which may increase the disability of an individual with
spinal cord injury (SCI). Treatment options detailed in this review include
rehabilitation techniques and modalities, pharmacological options, injection
techniques, intrathecal baclofen, and surgery. This review will hopefully help
health professionals to be aware of the treatment alternatives available for
patients with SCI related spasticity.
PMID- 10685386
TI - Subspecialty certification in spinal cord injury medicine: past, present, and
future.
PMID- 10685387
TI - Ultrastructure of Pasteurella haemolytica-induced changes in gnotobiotic calf
lung.
AB - Gnotobiotic calves born and maintained in a germ-free environment until
inoculated with a pathogen are model animals for studying the progression of a
specific disease, such as pneumonic pasteurellosis. To investigate early
progression of pneumonic pasteurellosis, we compared the ultrastructure of
regions of gas-exchange in the lungs of three challenge-exposed and three
uninoculated control gnotobiotic calves. Three calves were inoculated
endobronchially with a bolus of 7.9 x 10(10) CFU of Pasteurella haemolytica A1
and studied in a specific pathogen-free environment until severe respiratory
distress occurred, at which time they were euthanized. Slices of lung tissue from
the midregion of the right dorsal caudal lobe (area of lesion) of infected and
control calves were fixed in glutaraldehyde and prepared for scanning (SEM) and
transmission (TEM) electron microscopy. SEM revealed bacteria among long tangled
strands of fibrin in pulmonary alveoli that became obliterated with cellular
debris. TEM revealed areas of encapsulated and/or nonencapsulated bacteria among
the cellular debris and patches of fibrin. Many neutrophils and macrophages that
infiltrated the alveoli had phagocytosed bacteria and undergone degradation. Less
cellular damage was present when encapsulated bacteria bordered the interalveolar
septa than when nonencapsulated lysed bacteria were present. Where lysed bacteria
were present, the pulmonary capillaries were dilated because of swollen,
degranulated neutrophils, fibrin clots, and cellular necrosis. Both encapsulated
and nonencapsulated bacteria were present in the lung tissue of gnotobiotic
calves within the first 24 h after endobronchial inoculation of early log phase
P. haemolytica. Loss of capsular material around individual and divided pairs of
bacteria led to their consequential aggregation, lysing, and severe damage to the
adjacent pulmonary capillaries and interalveolar septa.
PMID- 10685388
TI - Morphometric analysis of the endometrial epithelium of rats (Rattus norvegicus
albinus) submitted to chronic experimental alcoholism.
AB - The effects of alcohol ingestion on the epithelial layer of the uterine
endometrium of rats submitted to experimental chronic alcoholism were observed by
morphometric methods. Sixty adult rats (Rattus norvegicus albinus) of the same
age (3 months) and weighing on average 228 g were divided into two groups. The
control group received solid diet, rat chow, and tap water ad libitum. The
experimental group received the same solid diet and was allowed to drink only
sugar cane brandy dissolved in 30 degrees Gay Lussac (v/v). At the end of 90, 180
and 270 days of treatment, the animals at estro were anaesthetized with ethyl
ether, weighed and sacrificed. The internal reproductive organs were dissected,
weighed and fixed. The final mean body weights were similar in the control and
alcoholic groups. The histological results showed intense atrophy of the lining
epithelium of the endometrium of uterine horns in the alcoholic group.
Morphometric analysis confirmed the endometrial epithelial atrophy, showing that
the alcoholic group had small cytoplasmic and nuclear areas and small cytoplasmic
and nuclear perimeter compared to the control group. Scanning electron
microscopic images showed intense lipid droplets accumulation in the epithelial
cells from alcoholic group. Therefore, we concluded that alcohol acts as a toxin
on the epithelial layer of the rat endometrium.
PMID- 10685389
TI - Effect of low temperature on mast cell exocytosis. Early cytoplasmic vesicle
formation and the role of cytoskeleton.
AB - Mast cells stimulated with adriamycin at 4 degrees C underwent a unique
exocytotic reaction. Rat peritoneal cells including mast cells were stimulated in
vitro with adriamycin (100 micrograms/ml) for 0, 10, 30 or 60 sec and observed by
transmission electron microscopy. Early changes could be observed after 10 sec
stimulation and consisted in an approximately 5-fold increase (p < 0.001) of 0.05
0.2 micron diameter cytoplasmic vesicles. The Golgi apparatus showed signs of
activation and vacuolization. From 10 to 30 sec, cytoplasmic vesicles fused with
the perigranular membranes and with the membranes of developing secretory
channels. At 60 sec, the number of vesicles and vacuoles diminished to nearly two
fold starting levels. The exocytotic reaction characteristically resulted in the
formation of enormously dilated granular cavities. The secretory process appeared
incomplete; after 60 sec, in fact, maximal histamine release was 20% and
exocytosis could be found in approximately 30% of mast cells. Pre-incubation with
vinblastine followed by adriamycin stimulation at 37 degrees C determined a dose
dependent inhibition of histamine release which was accompanied by the
ultrastructural appearance of numerous 0.05-0.5 micron cytoplasmic vesicles and
by signs of inhibited exocytosis. Our results support the concept that
hyperstability of the cortical cytoskeleton coupled with microtubule perturbation
would be responsible for the depressed pattern of mast cell exocytosis observed
at 4 degrees C. Although stimulation at 4 degrees C induces a paradoxal secretory
process, we believe that this approach may represent a useful model for
understanding some basic mechanisms of exocytosis in mast cells.
PMID- 10685390
TI - Morphological features of regeneration of rabbit aortic endothelium after
cryoinduced vascular damage.
AB - Regeneration of endothelium after damage is an important factor, which limits the
development of atherogenesis. This study examines the topographical
characteristics of regenerating endothelial cells (EC) in rabbit aorta after de
endothelialization by cryodestruction. The effects of cloricromene on these
processes were also studied. Vessels were harvested from 6-month-old NZW rabbits,
1 and 3 days after cryodestruction. The vessels were evaluated using scanning
electron microscopy (SEM). One day after cryodestruction, there were defects in
the endothelial monolayer in the zone of injury in saline treated animals. Large
numbers of platelets and monocytes were observed in association with endothelium
in the damaged zone. Three days after de-endothelialization the size of the area
of the damage had decreased. On the surface of the new endothelial layer and
below this defect, the number of adhering monocytes was increased, and many
microdefects between endothelium could be seen. Administration of cloricromene
for 1 or 3 days after damage reduced the number of endothelium-adherent platelets
and monocytes, and microdefects in endothelium. The feature of endothelial repair
in rabbits is a relatively large involvement of monocytes and platelets, which
are visible below regenerated endothelium. Administration of cloricromene
essentially restored re-endothelialization and significantly decreased the number
of adherent monocytes and microdefects in the new endothelium.
PMID- 10685391
TI - Ultrastructural alterations in the adrenal gland cortex of mice experimentally
infected with a Venezuelan isolate of Trypanosoma evansi.
AB - The ultrastructural study of adrenal gland from mice experimentally infected with
Trypanosoma evansi, in addition to intravascular and intracellular trypanosomes,
showed different degrees of cortical cell alterations and capillary wall
modifications. Beside its biological scope, these results suggest a role for the
adrenal cortex to partake in Surra's etiopathogenesis and describe for the very
first time a T. evansi intracellular stage.
PMID- 10685392
TI - Lymphatic vessels of the human heart: precollectors and collecting vessels. A
morpho-structural study.
AB - Only topographic and distributional data are available on the lymphatic outflow
vessels of the human heart. Here we describe their structural and ultrastructural
features. Fragments of the atria, ventricles and fat surrounding the major
coronary branches were obtained from hearts of dilated cardiomyopathy patients.
Serial semithin sections were observed under light microscopy and used for
tridimensional reconstructions. Ultrathin sections were observed by transmission
electron microscopy. Precollectors, the initial lymphatic outflow routes of the
heart, are small valved vessels with irregular, discontinuous musculature. They
originate in the subepicardial region from a network of epicardial, and from
scattered myocardial absorbing lymphatic vessels and drain into the collecting
vessels accompanying the major coronary branches. Collecting vessels are larger
but structurally similar to precollectors. Wall musculature is independent of the
size of the vessel. Their ultrastructure is the same as that of precollectors.
Endothelial cells have many Weibel-Palade bodies, cytoplasmic filaments and focal
adhesions. The basement membrane is discontinuous and anchoring filaments are
frequent and conspicuous. The subendothelial layer contains much elastin. Human
heart collecting vessels and precollectors may only be distinguished by their
size. The scarcity of musculature suggests that lymph progression in this
district is mainly ensured by cardiac revolutions. Their ultrastructural features
are determined by adaptation to dynamic forces. The architecture of these vessels
(random, disorderly, discontinuous, lacking any exact plan) and their large
variations in caliber are in line with the ontogenetic hypothesis that peripheral
lymphatic vessels originate from the coalescence of mesenchymal lacunae.
PMID- 10685393
TI - Ultrastructural identification of cells with dendritic cell appearance in
atherosclerotic aorta of apolipoprotein E deficient mice.
AB - The present electron microscopic study was undertaken to see whether cells with a
dendritic cell appearance accumulate in atherosclerotic lesions of apolipoprotein
E (apoE) deficient mice. Atherosclerotic aortas from 7 eight-month old apoE
deficient mice were examined. In atherosclerotic plaques as well as in the
underlying media and adventitia, cells with a dendritic cell appearance including
the presence of a unique tubulovesicular system were detected. The
tubulovesicular system was most hypertrophied in their cellular processes where
the continuous cisterns sometimes formed circular structures. The cells
containing the tubulovesicular system lacked lysosomes and phagolysosomes and
their cytoplasm was free of lipid inclusions. The present observations suggest
that dendritic cells are involved in apoE deficient mouse atherosclerosis. ApoE
deficient mice might be a useful model for investigating functions of dendritic
cells in atherogenesis.
PMID- 10685394
TI - Cytotoxic effects of eosinophils on renal proximal tubular epithelial cells:
implications for renal allograft rejection.
AB - Eosinophils are inflammatory cells that actively participate in the defense
against large, multicellular parasites. Eosinophils are also a prominent
component in the inflammatory infiltrates seen in acute allograft rejection.
Their role in that process, however, remains obscure. In this study we examined
in vitro the direct cytotoxicity of eosinophils against renal proximal tubular
epithelial cells (PTEC) in the presence or absence of antibody and complement.
Eosinophils were able to attach to the PTEC surface in both circumstances, i.e.,
irrespective of opsonization, or other mediation by humoral factors. The release
of eosinophil granule contents (including their characteristic crystalloids) on
the target cell surface and resulting PTEC injury occurred also irrespective of
the presence or absence of opsonization. Thus, based on these results, the
potential of direct cytotoxicity of eosinophils for PTEC exists, particularly in
situations where both of these cell types are 'activated'.
PMID- 10685395
TI - Ultrastructural pathology in skeletal muscle of mice envenomed with Crotalus
vegrandis venom.
AB - In this ultrastructural study we examined skeletal muscle fibres from mice
intraperitoneally inoculated with a sublethal dose of Crotalus vegrandis
(rattlesnake) venom. The group of mice inoculated presented neurological symptoms
characterised by respiratory failure and hind limbs paralysis. Skeletal muscle
fibres showed different degrees of alterations. Most of them presented the
characteristic pattern of necrosis in progress. Atrophied and hypercontracted
fibres were frequently seen. Some atrophied and necrotic fibres showed several
nucleoli-like bodies in the nucleus. In the atrophic and hypercontracted fibres,
sarcoplasmic vacuolation and abnormal mitochondria with stacked cristae were
observed. Areas of segmental necrosis were also frequently found. In connection
with these altered muscle fibres, capillary abnormalities were detected. This
study suggests that in envenomed mice respiratory failure symptoms may be related
with muscle damage caused by Crotalus vegrandis venom components.
PMID- 10685396
TI - A quick molecular method for the simultaneous detection in spermatozoa of
nuclear, acrosomal and axonemal structure by fluorescent microscopy.
AB - Ejaculated spermatozoa from infertile men presenting to our laboratory for semen
analysis were processed with a new molecular method which reveals simultaneously,
in the same sperm cell, the status of the acrosome, by testing the hyaluronidase
content, the texture of the nucleus, by checking the DNA strands breaks, and the
structure of the axoneme, revealing the tubulin content. The presence of
hyaluronidase and tubulin is essential for the sperm function, and the analysis
of the DNA status reveals the eventual apoptotic process. Using this method in
normal spermatozoa, the staining of the acrosomal hyaluronidase reveals, by
yellow-green fluorescence, the shape of the acrosomal complex and its texture. At
the same time, in the same sperm cell, the staining of the axonemal tubulin
demonstrates, by a red labeling, the presence of the protein and therefore the
consistence of the axonemal structure. Simultaneously, at the head level, the
absence of red labeling from nuclear DNA indicates that the apoptotic process is
not present. This protocol allows quantification of the frequency of the presence
of normal or abnormal spermatozoa, by an easy scoring and calculation of the
apoptotic sperm or of the sperm with generic defects at acrosomal or flagellar
level. The percentage of normal spermatozoa evaluated by the triple staining
method has been compared with the results of the PAP staining and of the
ultrastructural analysis, statistically elaborated. Triple staining results more
severe than the PAP method, but TEM analysis is the finest technique to detect
sperm abnormality because it considers the entire panel of sperm defects.
PMID- 10685397
TI - Estrogen protects peripheral and cerebral blood vessels from toxicity of
Alzheimer peptide amyloid-beta and inflammatory reaction.
AB - Due to increases in life expectancy, women are living 30 years or more beyond
menopause. This has led to an increasing interest in the association between
postmenopausal estrogen deficiency and degenerative diseases associated with
aging such as cardiovascular disease, osteoporosis and dementia. Women are two
times more likely to develop late-onset Alzheimer's disease (AD) than age-matched
men. A large number of observational reports and a few randomized clinical trials
have indicated that estrogen replacement therapy (ERT) may retard the development
and severity of dementia in postmenopausal women. The mechanism underlying the
protective action of estrogen in AD is under active investigation. A chronic
inflammatory reaction mediated by abnormal deposition of proteins such as amyloid
beta (A beta) is central to the pathology of AD. We investigated the effect of
low doses of conjugated estrogen (Premarin) in an animal model of A beta-induced
vascular disruption and inflammatory reaction. This rodent model allows live
videomicroscopic recording and electron microscopic analysis of peripheral
vascular disruption and inflammatory reaction triggered by A beta. Estrogen
prevented vascular deposition of A beta, endothelial and vessel wall disruption
with plasma leakage, platelet and mast cell activation, and characteristic
features of an inflammatory reaction: adhesion and transmigration of leukocytes.
The beneficial effect was lost when estrogen treatment was discontinued. Estrogen
also protected the cerebral blood vessels from endothelial dysfunction induced by
A beta. This novel protective effect of estrogen against A beta cytotoxicity in
peripheral and cerebral vasculature may contribute to the therapeutic efficacy of
estrogen in AD and coronary vascular disease.
PMID- 10685398
TI - Alteration of the follicular basement membrane in non-obese diabetic mice with
spontaneous autoimmune thyroiditis.
AB - The follicular basement membrane (FBM) prevents thyroglobulin from escaping to
the peri-follicular space, where it can act as an antigen to induce experimental
thyroiditis. Laminin, a component of the FBM, is responsible for directing cell
migration and stimulates greater adhesion of activated T lymphocytes. Our purpose
was to study the expression of laminin in the thyroid of NOD mice, which have a
propensity for autoimmune diseases, including thyroiditis. Thirty NOD mice
between 3 and 42 weeks old were studied. Eight had thyroiditis and 22 showed no
inflammatory infiltration. An immunohistochemical examination using the
streptavidin-biotin-peroxidase technique was conducted on paraffin-embedded
tissue sections, with a polyclonal antilaminin antibody. Antigen retrieval was
achieved through pepsin digestion and microwave irradiation in citrate buffer.
Staining for laminin was restricted to the basement membrane. In thyroids with no
infiltration, laminin was shown as a fine, continuous brown line in the basement
membrane. In 6 out of the 8 cases of thyroiditis, clearcut interruption and
destruction of the FBM was observed, particularly when the follicles were located
in lymphocyte infiltrated areas or when there was fibrosis. There were
significant alterations in the pattern of the FBM with extensive areas of
discontinuity in the distribution of laminin. Such discontinuities could
facilitate antigen exposure, especially thyroglobulin, which may contribute to
autoimmune thyroiditis in NOD mice.
PMID- 10685399
TI - Amorphous matrices in pathology: their definition and place in the spectrum of
morphological variations in the vessel-stroma interface. (Re: Lugassy et al.,
1998. Angio-tumoral laminin in murine tumors derived from human melanoma cell
lines. Immunohistochemical and ultrastructural observations. J. Submicrosc.
Cytol. Pathol., 30, 231-237)
PMID- 10685400
TI - Construction of libraries for isolation of adrenergic receptor genes.
PMID- 10685401
TI - Isolation of adrenergic receptor genes.
PMID- 10685402
TI - Analyses of adrenergic receptor sequences.
PMID- 10685403
TI - Polymerase chain reaction screening of genomic libraries for adrenergic receptor
genes.
PMID- 10685404
TI - Solution-phase library screening for identification of rare adrenergic receptor
clones.
PMID- 10685405
TI - Genetic polymorphisms of adrenergic receptors.
PMID- 10685406
TI - Northern blot analyses detecting adrenergic receptor mRNAs.
PMID- 10685407
TI - Ribonuclease protection assay for the detection of beta 1-adrenergic receptor
RNA.
PMID- 10685408
TI - Determination of adrenergic receptor mRNAs by quantitative reverse transcriptase
polymerase chain reactions.
PMID- 10685409
TI - Nuclear run-on assays for measurement of adrenergic receptor transcription rate.
PMID- 10685410
TI - Primer extension methods for determination of beta 1-adrenergic receptor mRNA
start sites.
PMID- 10685411
TI - Use of eukaryotic vectors for the expression of adrenergic receptors.
PMID- 10685412
TI - Expression of beta-adrenergic receptors in recombinant baculovirus-infected
insect cells.
PMID- 10685413
TI - Expression of beta-adrenergic receptors in E. coli.
PMID- 10685414
TI - Use and pharmacological analysis of established and transfected cell lines
expressing adrenergic receptors.
PMID- 10685415
TI - Transient transfection and adrenergic receptor promoter analysis.
PMID- 10685416
TI - Antisense RNA/DNA-based techniques to probe adrenergic receptor function.
PMID- 10685417
TI - Targeted disruption of adrenergic receptor genes.
PMID- 10685418
TI - Development of antibodies to adrenergic receptors.
PMID- 10685419
TI - Western blot detection of adrenergic receptors.
PMID- 10685420
TI - UV crosslinking of adrenergic receptors and ligands. Detection by SDS-PAGE.
PMID- 10685421
TI - Detection of beta-adrenergic receptors by radioligand binding.
PMID- 10685422
TI - Assessing adrenergic receptor conformation using chemically reactive fluorescent
probes.
PMID- 10685423
TI - Biochemical methods for detection and measurement of cyclic AMP and adenylyl
cyclase activity.
PMID- 10685424
TI - Assay of arachidonic acid release coupled to alpha 1- and alpha 2-adrenergic
receptors.
PMID- 10685425
TI - Patch-clamp recording methods for examining adrenergic regulation of potassium
currents in ocular epithelial cells.
PMID- 10685426
TI - Southwestern blots for detection of a DNA binding protein recognizing the alpha
1B-adrenergic receptor gene promoter.
PMID- 10685427
TI - DNase I footprinting analysis of transcription factors recognizing adrenergic
receptor gene promoter sequences.
PMID- 10685428
TI - Electrophoretic mobility shift assay for detection of DNA binding proteins
recognizing beta-adrenergic receptor gene sequences.
PMID- 10685429
TI - Determination of mRNA stability and characterization of proteins interacting with
adrenergic receptor mRNAs.
PMID- 10685430
TI - Use of immunohistochemistry and confocal microscopy in the detection of
adrenergic receptors.
PMID- 10685431
TI - Distribution of alpha 2A- and alpha 2C-adrenergic receptor immunoreactivity in
the central nervous system.
PMID- 10685432
TI - Quantitative light microscopic autoradiography of alpha 2-adrenergic radioligand
binding sites.
PMID- 10685433
TI - In situ hybridization of adrenergic receptor mRNA in brain.
PMID- 10685434
TI - Use of electron microscopy in the detection of adrenergic receptors.
PMID- 10685435
TI - Family functioning and the adjustment of adolescent siblings in diverse types of
families.
PMID- 10685437
TI - Adolescent siblings in stepfamilies: functioning and adolescent adjustment.
Marital satisfaction, relationships, and roles.
AB - The current study is one of the few attempts to examine the quality of marital
relations in long-remarried families in diverse types of stepfamilies and compare
them to long-established marriages in never-divorced families using a
multimeasure, multirespondent design, which included observations. Early in a
remarriage the new stepparent is often in a position of greater marginality than
the biological parent is, and the marital relationship may be less central than
in nonstepfamilies. Thus, the important differences between first marriages and
remarriages may be in the salience rather than in the quality of the marital
relationship. This will be explored as relations among family subsystems and
child adjustment are examined in subsequent chapters.
PMID- 10685436
TI - Adolescent siblings in stepfamilies: family functioning and adolescent
adjustment.
PMID- 10685438
TI - Parent-adolescent relationships in nonstep-, simple step-, and complex
stepfamilies.
PMID- 10685439
TI - Sibling, half sibling, and stepsibling relationships in remarried families.
PMID- 10685440
TI - Adolescent adjustment in nonstepfamilies and stepfamilies.
PMID- 10685441
TI - Relations among relationships: a family systems perspective.
PMID- 10685442
TI - Family functioning in nonstepfamilies and different kinds of stepfamilies: an
integration.
PMID- 10685443
TI - Stepfamilies: the intersection of culture, context, and biology.
PMID- 10685444
TI - Microbiological characteristics and susceptibility patterns of strains of
Rhodotorula isolated from clinical samples.
AB - The members of the genus Rhodotorula show a marked ubiquity. In man, they have
been isolated from faeces, nails, skin, sputum, digestive tract and adenoids,
forming part of the normal human flora, although in recent years cases have been
reported of both local and systemic infection by this yeast. There are virtually
no studies in the literature on the sensitivity of this genus to the antifungal
agents in common clinical use. Therefore, it is considered of interest to study
the microbiological characteristics and the susceptibility patterns of
Rhodotorula isolated from clinical samples. A total of 35 different strains of
Rhodotorula were studied. In vitro susceptibility testing to 5-fluorocytosine,
amphotericin B, ketoconazole, fluconazole and itraconazole was performed. All the
strains were considered sensitive to 5-fluorocytosine, amphotericin B,
ketoconazole and itraconazole and resistant to fluconazole. As a conclusion, we
can state that all the antifungal agents tested, except fluconazole, are useful
medicaments for the treatment of infections by the Rhodotorula genus.
PMID- 10685445
TI - Purification of the endospores and sporangia of Rhinosporidium seeberi on Percoll
columns.
AB - Human rhinosporidial tissue was used as the source of the various developmental
stages of Rhinosporidium seeberi--endospores with electron dense bodies,
juvenile, and immature sporangia. After homogenisation in phosphate buffered
saline (PBS) and removal of tissue fragments by centrifugation, the
rhinosporidial bodies were isolated on centrifuged Percoll columns with gradients
of densities or on triple-layered columns of varying density. The separated
bands, after repeated washing in PBS gave bodies free from human tissue as shown
on Leishman and PAS staining and indirect immunofluorescence with rabbit and
human patients' anti-rhinosporidial sera. Sonicates of these bodies were tested
on agarose gel for precipitation with antisera, and on SDS-PAG electrophoresis
and Coomassie Blue staining. Percoll columns were shown to be capable of
isolating these stages of R. seeberi, free from human tissue and contaminating
bacteria.
PMID- 10685446
TI - Female genital coccidioidomycosis (FGC), Addison's disease and sigmoid loop
abscess due to Coccidioides immites; case report and review of literature on FGC.
AB - We describe a woman with unusual complications of infection with Coccidioides
immitis--infection of the genital tract and adrenal insufficiency. The patient
also had intestinal coccidioidomycosis (cocci) in conjunction with presumed
pulmonary, and asymptomatic central nervous system cocci. To our knowledge,
concurrent FGC, intestinal and adrenal cocci have not been reported previously. A
MEDLINE review from 1966-1997 revealed only 1 case of adrenal insufficiency due
to cocci. FGC is rare; we identified 12 reported cases since 1929. No combination
of investigations or clinical features is sensitive enough to predict FGC.
Diagnosis is usually made after microscopy of surgical specimens. FGC presents
either as tubo-ovarian disease or endometritis. Treatment generally involves
surgical excision and antifungal agents. We hypothesize that an initial trial of
antifungals may obviate the need for surgery.
PMID- 10685447
TI - Endocarditis by Aspergillus fumigatus in a renal transplant.
PMID- 10685448
TI - Comparative study of agar diffusion test and the NCCLS macrobroth method for in
vitro susceptibility testing of Candida spp.
AB - We performed a prospective double-blind study to evaluate the correlation between
inhibition zones obtained by a disk-diffusion test, using Neo-sensitabs of
fluconazole (Rosco Diagnostica), and the MICs generated by the NCCLS macrobroth
dilution assay. Eighty clinical isolates, representing 5 of the clinically
relevant species of Candida, were tested simultaneously by both methods. A clear
inverse correlation was found between the results obtained by both tests (r =
0.69). In addition, there was high degree of agreement between methods in the
identification of susceptible isolates. However, the resistance definition by
disk-diffusion test had a positive predictive value of only 17%. Our data support
the hypothesis that Rosco Fluconazole Neo-sensitabs have potential as a screening
test for the identification of Candida isolates susceptible to fluconazole.
Resistant isolates should be further investigated by standardized broth
procedures.
PMID- 10685449
TI - Prevalence of dermatophytoses in the Zarqa district of Jordan.
AB - A total of 350 clinically suspected cases of dermatomycoses were examined for
causative fungi during July 1997 to September 1998. Mycotic infection was
demonstrable by microscopy and culture in 199 (56.8%) cases. The most common
superficial mycotic infections were tinea pedis (35.2%) followed by tinea capitis
(23.1%), tinea unguium (21.6%) and tinea corporis (10.6%). Most of the infected
patients were 1-9, 20-29 and 30-39 years old. Men were mainly infected with tinea
cruris and tinea pedis, while women were infected with tinea pedis, tinea unguium
and tinea capitis. The frequencies of etiological agents isolated from patients
were as follows: Trichophyton mentagrophytes var. interdigitale (32.7%), T.
rubrum (28.6%), Epidermophyton floccosum (20.1%), Microsporum canis (11.1%), T.
schoenleinii (4%), T. verrucosum (2%), T. violaceum (1%), and M. gypseum (0.5%).
The number of infections varied with the seasons. The highest number of cases of
tinea pedis and tinea cruris occurred in the summer months, while tinea capitis,
tinea corporis and tinea unguium occurred in the spring and winter months.
PMID- 10685450
TI - [Evidence-based medicine: from concept to practice].
PMID- 10685451
TI - [Analysis of hospitalization of adult sickle-cell patients in Guadeloupe].
AB - PURPOSE: To determine the characteristics of acute hospitalizations in adult
patient with sickle-cell disease in Guadeloupe. METHODS: We retrospectively
studied clinical features of adult patients followed up by the "Centre Caribeen
de la Drepanocytose" (CCD) in 1996. Data were collected from the medical records
of the hospitalized patients and the longitudinal records of the CCD. RESULTS:
Sixty-three (25%) of the 251 patients who were followed up by the CCD required
hospitalization in 87 cases (1.38 hospitalizations/patient). Mean age of the
hospitalized patients was 27.5 years (range 17 to 71 years). Most
hospitalizations involved men (29 [31%] vs 34 [22%] for women, P < 0.05), and
most were for homozygous patients with sickle-cell anemia: 39 (31%) SS, 19
(18.55%) SC and five (21.75%) S beta thal. A painful vaso-occlusive crisis was
noted in 67 episodes. There were nine acute chest syndromes (ACS), six of them
occurred following a vaso-occlusive crisis. We noted 39 infectious episodes. The
increase in C-reactive protein (> 100 mg/L) was associated with ACS or urinary
infection. A patient with renal failure died during septicemia. CONCLUSION: This
study confirms the need for prevention of painful crises and other severe
complications in patients with sickle-cell disease.
PMID- 10685452
TI - [Secondary cutaneous effects of hydroxyurea: prospective study of 26 patients
from a dermatologic consultation].
AB - PURPOSE: Hydroxyurea is a treatment of myeloproliferative syndromes. Its
cutaneous side-effects are underestimated, because they are usually benign. We
undertook a prospective study to evaluate their frequency. METHODS: During a 2
year period, all patients taking hydroxyurea for more than 6 months who had
consultations at the dermatology department were systematically examined,
regarding cutaneous side effects. RESULTS: Twenty-six patients were examined. All
but one had cutaneous side-effects, including dryness (n = 16), moderate alopecia
(n = 2), increased skin pigmentation (n = 5), melanonychia, single (n = 1) or
multiple (n = 7), cutaneous atrophy (n = 4), leg ulcers (n = 8), plantar
keratoderma (n = 3), pseudodermatomyositis (n = 1), lichen planus-like eruption
on the dorsum of the hands (n = 2), actinic keratosis (n = 8), squamous cell
carcinomas (n = 2), and mouth ulcerations (n = 1). CONCLUSION: This study shows
that the frequency of hydroxyurea cutaneous side-effects diagnosed in 95% of
studied patients is underestimated. They are usually benign, but some of them, in
particular leg ulcers and squamous cell carcinomas, lead to modification of the
treatment (39% of studied patients).
PMID- 10685453
TI - [Mechanisms of amyloidosis and the proteins involved].
AB - INTRODUCTION: Recent data in amyloid research have shed light on the amyloid
substance and have broadened our knowledge on the mechanism of amyloid
deposition. CURRENT KNOWLEDGE AND KEY POINTS: Despite uniform physical properties
relating to the presence of beta-pleates, amyloid deposits are chemically
heterogeneous and have different origins; additional types will probably be
described in the future. Immunohistochemical techniques using specific antisera
for each of the major protein present in fibrils could help greatly to
subclassify these disorders. In most circumstances, a circulating precursor
protein may result from overproduction of either intact or aberrant molecule, a
reduction in its degradation or excretion, or genetic abnormalities associated
with variant proteins. The cleavage of protein precursor molecules of the protein
component of amyloid fibrils characterizes amyloidogenesis, though it is not
necessary for some amyloidosis forms. This review summarizes advances in the
understanding of the nature of amyloid substances, the mechanism of amyloid
deposition and the principal pathogenic hypothesis. FUTURE PROSPECTS AND
PROJECTS: SAP component is common in all amyloidosis and may be the target for
future therapy.
PMID- 10685454
TI - [Clinical forms of hepatitis A].
AB - INTRODUCTION: Although its incidence has decreased during the last 20 years,
hepatitis A is still the most common hepatitis. In most cases, hepatitis A is
asymptomatic. When it is symptomatic, the course is benign in most cases. The aim
of this review is to summarize current data regarding unusual clinical forms of
hepatitis A. CURRENT KNOWLEDGE AND KEY POINTS: Hepatic insufficiency is the most
severe complication of hepatitis A. It is more commonly observed in adult
patients. In most cases, the outcome of hepatic insufficiency is rapidly
favorable. In rare cases, hepatic insufficiency progresses and encephalopathy
subsequently occurs. At this stage, emergency liver transplantation may be
necessary. Apart from hepatic insufficiency, the course of hepatitis A may be
characterized by a relapse following initial improvement (relapsing hepatitis A)
and prolonged cholestasis. FUTURE PROSPECTS AND PROJECTS: In regard to patients
with liver insufficiency, physicians should be educated about the need to prevent
all iatrogenic factors which could impair the outcome and to maintain a situation
propitious to rapid liver regeneration, a necessary condition for recovery. When
this prevention fails and liver transplantation has to be considered, auxiliary
transplantation should always be considered because this procedure preserves the
possibility of a delayed regeneration. The justification of systematic
vaccination of patients with chronic hepatitis B, who could be at higher risk for
hepatic insufficiency during hepatitis A, is controversial.
PMID- 10685455
TI - [Non-surgical treatments of esophageal cancers].
AB - INTRODUCTION: Despite improvements in surgical techniques and perioperative
mortality, only slight improvements in the 5-year survival of patients with
esophageal cancer have been observed in the last 20 years. Many patients with
apparently localized cancer will have recurrences or metastatic disease despite
surgery with curative resection. Consequently, multimodal therapies, including
chemotherapy and radiotherapy, were introduced. This review outlines and
critically analyzes current non-surgical treatments, including palliative care.
CURRENT KNOWLEDGE AND KEY POINTS: Esophageal cancers appear to be chemosensitive
but the median duration of response is short and toxicity consistent, especially
in metastatic disease. Consequently, palliative chemotherapy should be offered
preferably within a clinical trial. Chemotherapy as the only adjuvant treatment
cannot be recommended outside clinical trials. Radiotherapy alone as a curative
treatment has been proven to be inferior to chemoradiotherapy in inoperable
tumors. Some data support the use of preoperative chemoradiotherapy, but
randomized trials are conflicting. A pathological complete response has been
identified as a favorable prognostic factor for survival. Self-expanding
esophageal metal stents are a simple and effective palliative treatment of
malignant dysphagia and can be considered as the reference treatment in patients
with obstruction of the lower esophagus or with fistula. FUTURE PROSPECTS AND
PROJECTS: Taxanes should be evaluated in randomized studies using chemotherapy or
chemo-radiotherapy. Progress in radiotherapy, such as accelerated fractionation,
greater radiation dose, and the addition of brachytherapy, will increase
locoregional control and probably survival. The role of secondary surgery in
patients responding to chemoradiotherapy still needs to be answered.
PMID- 10685456
TI - [Bronchiolitis obliterans with organized pneumonia: a rare complication of
primary Gougerot-Sjogren syndrome].
AB - INTRODUCTION: Bronchiolitis obliterans organizing pneumonia (BOOP) is
characterized by plugs of granulation tissue in bronchioles, alveolar ducts and
alveoli. This pulmonary disorder has been reported in some cases in relation to
drug consumption (D-penicillamine, amiodarone), with bacterial or viral
infections (Mycoplasma pneumoniae, HIV), and with systemic diseases, such as
rheumatoid arthritis. To our knowledge, only three cases of association BOOP
Sjogren's syndrome have been reported. EXEGESIS: We report three new cases of
BOOP. These patients presented a primary Sjogren's syndrome without clinical or
biological abnormalities suggestive of other autoimmune diseases. Initial
presentation was an acute pulmonary disorder mimicking a bacterial pneumonia. Two
patients had cutaneous vasculitis and the third vasculitic neuropathy.
Corticosteroid therapy was begun and was quickly successful. None of the patients
presented a relapse of BOOP. CONCLUSION: The incidence of BOOP is probably
underestimated in patients with primary Sjogren's syndrome without cutaneous
vasculitis. In case of pneumonia with antibiotic resistance, an immunological
mechanism should be considered.
PMID- 10685457
TI - [Rheumatoid arthritis preceding microscopic polyangitis. Report of two cases].
AB - INTRODUCTION: Although joint manifestations are common in microscopic
polyangiitis (MPA), including arthralgia reported in 15-65% of cases and
arthritis in 6-17%, there have been only two published cases of polyarthritis as
the first manifestation of the disease. We report on two new cases. EXEGESIS: A
71-year-old woman had symmetric polyarthritis of the hands which initially
suggested the existence of seronegative rheumatoid arthritis. A 52-year-old woman
had seropositive asymmetric oligoarthritis. The diagnosis was not established
until renal insufficiency appeared, prompting a renal biopsy which showed in both
cases an extra-capillary glomerulonephritis and an anti-myeloperoxydase (p-ANCA)
assay which was postive in both patients. The incidence and specificity of
antineutrophil cytoplasmic antibodies (ANCA), including MPA, in rheumatoid
arthritis are reviewed. CONCLUSION: Our two observations show that in cases of
polyarthritis or oligoarthritis with renal involvement, testing for and typing of
ANCA should be performed so as not to misdiagnose vasculitis.
PMID- 10685458
TI - [Cryptococcal meningitis associated with chronic lymphocytic leukemia: a case
report. Review of the literature].
AB - INTRODUCTION: The authors report the occurrence of a cryptococcal meningitis in a
patient treated by corticosteroids and polychemotherapy for a chronic lymphocytic
leukemia. EXEGESIS: A 63-year-old man with chronic lymphocytic leukemia was sent
to hospital because of impaired condition with fever. Neurological disorders
appeared. Cryptococcal meningitis was diagnosed. Under treatment, the outcome was
favorable. CONCLUSION: This paper highlights the feature of this infection most
likely underestimated in HIV-seronegative patients and the need to a priori
consider this diagnosis.
PMID- 10685459
TI - [Hepatocellular carcinoma: a case revealed by metastatic orbital tumor].
AB - INTRODUCTION: We report a case of metastatic orbital tumor revealing
hepatocellular carcinoma. EXEGESIS: Metastatic orbital tumors of hepatocarcinoma
are rare. Only six cases have been reported. We compare these cases to our
observation. Treatment of the orbital metastasis is important to decrease pain,
ophthalmological symptoms and to improve the quality of survival. Radiotherapy
and/or surgery can be used. Prognosis for life depends on liver involvement: the
modalities of treatment of the hepatocarcinoma have to be discussed for each
patient. CONCLUSION: Seven cases of orbital metastasis revealing a
hepatocarcinoma have been documented. Effectiveness of radiotherapy makes the
local prognosis good, but prognosis depends on liver involvement, since prognosis
of hepatocellular carcinoma is poor.
PMID- 10685460
TI - [Lung neoplasms revealing a rare cutaneous tumor: eccrine porocarcinoma].
AB - INTRODUCTION: Eccrine sweat gland carcinoma, which belongs to the eccrine sweat
gland carcinoma family, is a rare malignancy of the skin with a potential
aggressive growth and metastatic spread. EXEGESIS: We report here a case of
malignant eccrine poroma arising on the upper leg, with widespread pulmonary
metastases. CONCLUSION: A brief synopsis of the pathological and clinical aspects
of eccrine sweat gland carcinoma is presented with the currently available
therapies.
PMID- 10685461
TI - [Olfactory disorders and general pathology. Analysis and review of the
literature].
AB - INTRODUCTION: Disturbances of the sense of smell have been documented in many
general pathologies. The actual etiology of such impairments is often difficult
to determine. The aim of the authors is to review the literature on olfactory
disorders in general diseases. CURRENT KNOWLEDGE AND KEY POINTS: Acute and
chronic liver disorders are frequently associated with hyposmia, which can be
improved by vitamin A intake. Renal insufficiency could induce hyposmia according
to the severity of the renal disease. Olfactory disorders seem to regress after
transplantation but not after dialysis. Patients with AIDS--especially
neurological forms--often present with taste and smell impairments. Smell
alteration can also be noted in hypothyroidism and pseudohypoparathyroidism. In
addition, taste and smell impairments have been described in patients with
adrenal insufficiency or Cushing's disease. Subsequent to glucocorticoid therapy,
adrenal insufficiency can induce regressive olfactory hypersensitivity. Olfactory
impairments in diabetic patients can be associated with diabetic macrovascular
manifestations due to ischemic alterations in the olfactory neuroepithelium.
Impairment of the sense of smell has been described in many systemic diseases
such as Horton's arteritis and Sjogren's syndrome. FUTURE PROSPECTS AND PROJECTS:
Olfactory disorders should be investigated in patients presenting one of the
above-mentioned diseases.
PMID- 10685462
TI - [From knowledge to clinical practice: the introduction of evidence-based
medicine].
AB - INTRODUCTION: The paper presents the new paradigm for medical practice which has
been emerging for a decade: evidence-based medicine. CURRENT KNOWLEDGE AND KEY
POINTS: The paradigm proposes new skills for the physicians, de-emphasizing
intuition and empiricism in medical practice, and proposes the intensive use of
medical literature for the medical practice. FUTURE PROSPECTS AND PROJECTS: The
article presents the main characteristics of the approach which is raising new
important questions about the evolution of medical practice and the validity of
the paradigm.
PMID- 10685463
TI - [An acute ossification of the hip].
PMID- 10685464
TI - [Lymphatic duct compression by an endothoracic goiter: an exceptional
observation].
PMID- 10685465
TI - [Polymyositis: a rare complication of interferon alpha therapy].
PMID- 10685466
TI - [Aortic Salmonella infection. A new observation].
PMID- 10685467
TI - [Mycobacterium avium-positive pulmonary sample and CD4+ lymphopenia not related
to human HIV].
PMID- 10685468
TI - [Comparing two groups of patients].
AB - In medical research, comparing two groups of patients occurs frequently. The
basic principles of comparison and the usual statistical tests--according to the
types of variables and the choices of sampling methods--are presented. Elements
needed for the computation of the size of a comparative study are given.
PMID- 10685469
TI - [Candida pneumopathy: fact or fiction?].
PMID- 10685470
TI - [Patient knowledge of asthma: results of a national survey in pneumology].
AB - Knowledge of asthma and its treatment were evaluated in a survey of 1,000
asthmatics using a self-questionnaire with closed questions. As far as the
disease was concerned, 87.4% of patients knew that the bronchi were the
pathological organ and 70.6% that the disease persisted between attacks. Overall
knowledge of the disease (pathological organ, persistence of the disease between
attacks, chronic inflammation associated with acute bronchoconstriction) was
adequate in only 25.6% of patients. It was associated with the educational level
[higher > primary; p = 0.001], the grade of asthma [severe > mild; p = 0.007] and
the number of medicines inhaled [(n > 3) > (N < 2); p = 0.001)]. As far as
medicines were concerned, knowledge of their mechanisms of action varied
according to therapeutic groups: antiallergics [78.6%], antibiotics [77.7%],
antihistamines [74.5%], LA beta2-mimetics [45.9%], theophylline [31.9%],
corticosteroids [31.7%], beta2-mimetics [24.8%]. No factor was statistically
correlated with greater familiarity. However, only 7.2% of patients treated with
metered-dose aerosols expressed handling problems and 78.8% of asthmatics
questioned felt that they were sufficiently informed about their disease and its
treatment. Information and education thus remain a priority in the management of
asthma.
PMID- 10685471
TI - [Serum procalcitonin and respiratory tract infections].
AB - The aim of our study was to evaluate the prognostic value of serum procalcitonine
(PCT) assay in adult respiratory infections. Forty-nine patients admitted with
pleurisy, community-acquired pneumonia, tuberculosis, infection were included in
this prospective study. PCT was assayed on admission and discharge. Biological
and clinical parameters of gravity were also evaluated. Twenty patients had
elevated PCT of more than 0.50 ng/ml. In 29 patients, PCT was undetectable. The
serum PCT level was normal in the patients with tuberculosis, infection,
pneumocytosis. PCT did not correlate with the biological and clinical markers of
the disease severity but the evolution of PCT correlated with the evolution of C
reactive-protein (r = 0.58, p < 0.05). PCT seems to be an early marker of the
evolution of respiratory infections, but it does not help to establish prognosis.
Further studies are necessary to assess the potential value of PCT in more severe
respiratory infections requiring assisted ventilation.
PMID- 10685472
TI - [Diffuse interstitial pulmonary fibrosis and bronchial cancer].
AB - Mortality due to lung cancer was 25% (7/28) in this study of patients with
diffuse interstitial pulmonary fibrosis. Opacities on the chest x-ray suggestive
of lung cancer were observed in 5 of the 7 cases. All 7 had squamous cell
carcinoma. The percentage of smokers was significantly higher in patients with
pulmonary fibrosis who developed lung cancer than in those with fibrosis who did
not develop lung cancer (p = 0.016). These 7 cases of lung cancer with pulmonary
fibrosis were compared with 174 cases of lung cancer without associated fibrosis.
Peripheral localizations and lower lobe involvement were higher in cases of lung
cancer with pulmonary fibrosis.
PMID- 10685473
TI - [Role of thoracic radiography in the management of community-acquired pneumonia].
AB - In patients presenting with a lower respiratory tract infection, it is generally
recommended to order a chest X-ray in two circumstances: when the clinical signs
suggest the diagnosis of pneumonia or in case of rather atypical symptoms
suggesting a potential risk of complications. Indeed, the presence of one or more
recent opacities, and more specifically, homogeneous alveolar infiltration(s)
remains the gold standard criterion for the diagnosis of pneumonia. One must not
however let this rule overshadow certain limitations of the chest X-ray reported
in the literature: 1. the misdiagnosis of certain cases of pneumonia or
bronchopneumonia seen early; 2. the extent of the infiltration gives only a very
relative assessment of severity; 3. the characteristics of the infiltration are
only relatively specific for etiological diagnosis. In patients with community
acquired pneumonia diagnosed on the basis of clinical signs and radiographic
findings, systematically performed series of follow-up X-rays have shown that the
initial extension of the infiltration and the rate of its resolution contribute
quite variably to the diagnosis of complications. The best indication for
ordering a follow-up X-ray before 6 weeks remains an unfavorable clinical course.
PMID- 10685474
TI - [Thyroid manifestations of sarcoidosis: a case report].
AB - Sarcoidosis is a systemic disease with many localizations. Thyroid involvement
has been often described but rarely confirmed histologically. A common immune
mechanism appears to be the cause. Thyroid sarcoidosis should be envisaged in
patients with a thyroid nodule and mediastino-pulmonary involvement. We report
the case of a 63-year-old woman with no past history who was hospitalized for
dyspnea. Explorations evidenced a cold thyroid nodule associated with diffuse
interstitial lung disease and mediastinal node enlargement. Pathology examination
disclosed the sarcoid nature of the thyroid nodule and the lung lesions.
PMID- 10685475
TI - [Hydatid thymic cyst. A case report].
AB - Hydatid thymic cyst is exceptional. The diagnosis is suspected by radiology and
epidemiology. Serology tests provide variable results and surgery is the only
treatment. We report a case of thymic hydatid cyst in a 20-year-old man who had
no other localizations. Diagnosis was confirmed at surgery and by histology.
PMID- 10685476
TI - [Bacteremia and Pasteurella multocida pneumonia revealing HIV infection].
AB - Pasteurella multocida is a major pathogen in local wound infections due to animal
bites. Pneumonia and bacteremia are less frequent and usually associated with
local or general impairment of host defenses. Scarce reports exist about
Pasteurella multocida infections in HIV infected patients. We report here a case
of hypoxemic pneumonia and bacteremia due to Pasteurella multocida revealing an
HIV infection in a young man.
PMID- 10685477
TI - Prognostic factors for time receiving workers' compensation benefits in a cohort
of patients with low back pain.
AB - STUDY DESIGN: Prospective inception cohort study. OBJECTIVE: To develop a
prognostic model that predicts time receiving workers' compensation benefits for
low back pain claimants. SUMMARY OF BACKGROUND DATA: As the cost and difficulty
of managing low back pain escalate, any predictor of outcome is advantageous.
METHODS: To obtain the outcome and predictor variables, patient data from two
separate databases were linked: a clinical database and an administrative
(Ontario workers' compensation) database. Claimants injured between January 1 and
December 31, 1994, were included and observed for 1 year from the date of
accident. The outcome variable was cumulative number of calendar days receiving
benefits. RESULTS: Multivariable Cox proportional hazards regression (forward
stepwise) showed eight significant predictors; five were associated with
increased time receiving benefits compared with their reference groups: 1)
working in the construction industry, 2) older age, 3) lag time from injury to
treatment, 4) pain referred into the leg, and 5) three or more positive Waddell
nonorganic signs. Three predictors were associated with reduced time receiving
benefits: 1) higher values of questionnaire score, 2) intermittent pain, and 3) a
previous episode of back pain. A predictive score was calculated to categorize
claimants as at high or low risk for chronicity. When an arbitrary cutoff point
was set at the 75th percentile of predictive score, negative predictive value was
94%. CONCLUSION: This research identified eight factors for time receiving
workers' compensation benefits among claimants with low back pain. This model
discriminates between high- and low-risk claimants. Few low-risk claimants
continued to receive benefits for more than 3 months.
PMID- 10685478
TI - Effect of augmentation on the mechanics of vertebral wedge fractures.
AB - STUDY DESIGN: The effect of cement augmentation of wedge-fractured vertebral
bodies on spine segment compliance was studied in 16 cadaver specimens.
OBJECTIVES: 1) To assess the mechanical effects of cement augmentation of
vertebral wedge fractures. 2) To determine whether a new reduction/injection
procedure has the same mechanical effects as the established direct injection
procedure. SUMMARY OF BACKGROUND DATA: Although wedge fractures cause pain and
disability in hundreds of thousands of people, few effective treatments are
available. Clinical studies have shown that cement augmentation, a new procedure,
effectively relieves pain and restores mobility in patients suffering from weak
or fractured vertebrae. However, only a few studies have examined the mechanics
of vertebral augmentation. METHODS: A wedge fracture was created in the middle
vertebra of 16 three-vertebra cadaver spine segments. Neutral and full-load
compliance of each fractured spine segment in flexion/extension and lateral
bending were assessed by measuring the relative rotation of the vertebral bodies
in response to applied moments. Eight of the fractured vertebral bodies were then
augmented using direct injection, while the remaining eight fractured vertebral
bodies were augmented using a combined reduction/injection procedure. Compliance
of the augmented segments was then assessed. RESULTS: Augmentation significantly
reduced the neutral compliance (reduction of 25% +/- 23%) (mean +/- standard
deviation) and the full-load compliance (reduction of 23% +/- 20%) in
flexion/extension (P < 0.005). Augmentation also significantly reduced the
neutral compliance (reduction of 34% +/- 20%) and the full-load compliance
(reduction of 26% +/- 17%) in lateral bending (P < 0.0001). No significant
difference was found between the two procedures for compliance reduction.
CONCLUSIONS: Augmentation of wedge fractures using both direct injection and
reduction/injection reduces spine segment compliance significantly.
PMID- 10685479
TI - Changes with age in proteoglycan synthesis in cells cultured in vitro from the
inner and outer rabbit annulus fibrosus. Responses to interleukin-1 and
interleukin-1 receptor antagonist protein.
AB - STUDY DESIGN: Proteoglycan synthesis was examined in cells isolated from the
inner and outer annulus fibrosus of young and old rabbits. Their responses to
interleukin-1 alpha and interleukin-1 receptor antagonist protein were
investigated. OBJECTIVES: To evaluate the age-related changes and the
anatomically related differences in the function of intervertebral disc cells.
SUMMARY OF BACKGROUND DATA: Proteoglycan content in the human intervertebral disc
decreases with age. Age-related changes in intervertebral disc cell function,
however, have not been fully investigated. METHODS: Japanese white rabbits aged 2
months (young group) and 3 years (old group) were used. The inner and outer layer
of the annulus fibrosus were separated. The proteoglycan synthesis and release
were measured in cells cultured with or without human recombinant interleukin-1
alpha and interleukin-1 receptor antagonist protein. RESULTS: The proteoglycan
synthesis significantly decreased and the release rate significantly increased in
the old rabbits, compared with the young ones. In the inner annulus, the
inhibition of proteoglycan synthesis due to interleukin-1 alpha was greater in
the old rabbits than in the young ones. In the old rabbits, interleukin-1-induced
inhibition was more pronounced in the inner annulus than in the outer annulus.
Interleukin-1 receptor antagonist protein suppressed inhibition of proteoglycan
synthesis by interleukin-1 alpha in the two layers in both age groups.
CONCLUSIONS: Both the decline in proteoglycan synthesis and the increased cell
sensitivity to interleukin-1 alpha with age may contribute to the degradation of
discs. The increase in cell response to interleukin-1 alpha in the inner annulus
of rabbits may explain why the inner annulus and nucleus pulposus degrade earlier
than the outer annulus in human discs. Interleukin-1 receptor antagonist protein
could be useful in inhibiting the degradation of the disc.
PMID- 10685480
TI - Load-sharing characteristics of stabilized lumbar spine segments.
AB - STUDY DESIGN: Load sharing in stabilized spinal segments was evaluated using
sequential injury and stabilization with a posterior instrumentation system under
an in vitro flexibility protocol. OBJECTIVE: To analyze the partitioning of
applied loads between anatomic and implanted structures of lumbar functional
spinal units stabilized with a posterior instrumentation system. To identify
surgical indications for which the risk of fixator breakage in vivo is high.
SUMMARY OF BACKGROUND DATA: Relatively few groups have experimentally measured
the in vitro and in vivo forces and/or moments supported by posterior
instrumentation systems, and no analysis, of the load sharing in these systems
has been performed. This information will provide novel insight into implant
fatigue life, and the degree to which the spinal anatomy is shielded from the
applied load and will allow the verification of mathematical models for new
injury scenarios. METHODS: Specimen kinematics were determined using an
optoelectronic tracking system. Intradiscal pressure and the forces and moments
supported by the implants were measured using, respectively, a needle-mounted
pressure sensor and strain gauges mounted on the spinal implants. RESULTS: A
large majority of the applied moments were supported by an equal and opposite
force pair between the intervertebral disc and fixator rods in flexion and
extension and an equal and opposite force pair between the left and right fixator
rods in lateral bending. Torsional moments were shared approximately equally
between the posterior elements, intervertebral disc, an equal and opposite shear
force pair in the transverse plane between the right and left fixators and
internal fixator moments. CONCLUSIONS: When posterior instrumentation devices are
used to stabilize severe anterior column injuries, they are at risk of fracture
secondary to reversed bending moments.
PMID- 10685481
TI - Transverse-contour modeling of trunk muscle-distributed forces and spinal loads
during lifting and twisting.
AB - STUDY DESIGN: An electromyography-assisted biomechanical model was developed
using electromyographic (surface and in-dwelling) data collected during
asymmetric lifting and twisting activities. OBJECTIVES: To develop a
biomechanical model of the lumbar region that considers the ability of the broad,
flat muscles of the trunk (external obliques, internal obliques and latissimus
dorsi) to activate different anatomic regions at different intensity levels and
then uses this information to describe the spine reaction forces that result
during lifting and twisting tasks. SUMMARY OF BACKGROUND DATA: Many biomechanical
models of the lumbar region use single-vector representations for the external
oblique, internal oblique, and latissimus dorsi muscles. This simplification
limits the description of the complexity of the resultant forces produced by
these muscles and does not consider their differential activation capacity.
METHODS: Human subjects performed lifting and twisting exertions while muscle
electromyographic activities were sampled at one location on the rectus abdominis
and erector spinae muscles and at multiple locations on the latissimus dorsi,
external oblique, and internal oblique muscles. These data were used in
conjunction with in vivo digitized muscle origin and insertion points to predict
muscle forces and spine loads through the use of the electromyography-assisted
modeling method. RESULTS: The measures of model performance such as percentage of
error (6-21%) in the prediction of the external torques, correlations (0.83-0.98)
between internal and external torques and the values of predicted muscle force
capacity were all similar to data collected in previous electromyography-assisted
models, but the predictions of spinal loading, particularly shear forces, were
quite different. The results have shown that by modeling the broad, flat muscles
of the torso using multiple-force vectors, the calculated shear forces in the
spine were reduced. CONCLUSIONS: The multivector, transverse-contour model
developed in this research illustrates the importance of realistic multiple
vector modeling and the importance of considering the selective-activation
capacity of the abdominal oblique musculature.
PMID- 10685482
TI - Clinicoradiologic study of cervical laminoplasty with posterolateral fusion or
bone graft.
AB - STUDY DESIGN: A retrospective study of cervical expansive laminoplasty for
cervical myelopathy from a clinicoradiologic perspective. OBJECTIVE: To clarify
the correlation among sagittal curvature of the cervical spine, cervical range of
motion, sagittal plane translation, spinal cord atrophy, and myelopathic symptoms
in patients who have undergone laminoplasty. SUMMARY OF BACKGROUND DATA:
Laminoplasties were developed to diminish the undesirable effects of laminectomy,
which include postoperative kyphotic changes and instability. However, the
superiority of laminoplasty over laminectomy remains controversial. METHODS:
Fifty-one patients with cervical spondylotic myelopathy or ossification of the
cervical posterior longitudinal ligament who underwent laminoplasty were
radiologically assessed before and after surgery. The index of the sagittal
curvature, intervertebral range of motion, listhesis, and the transverse area of
the spinal cord at the site of maximal compression were measured to evaluate
interrelations among those parameters and myelopathic symptoms. RESULTS: There
were no patients with kyphotic curvature before surgery. The postoperative
curvature tended to be less lordotic. This tendency did not adversely affect
postoperative symptoms. The intervertebral range of motion was significantly
decreased except at C1-C2. The final C4-C5 range of motion and the postoperative
myelopathic symptoms were negatively correlated. A significant correlation was
observed between the postoperative spinal cord atrophy and the final myelopathic
symptoms. CONCLUSIONS: The decrease in the lordotic curvature index and the
decrease in the intervertebral range of motion after laminoplasty did not cause
neurologic deterioration. In the C4-C5 intervertebral segment with a high
incidence of listhesis, the restriction of the C4-C5 range of motion improved the
clinical myelopathic symptoms. The radiologic prognostic factors were the
postoperative restriction of intervertebral range of motion in preoperatively
unstable segments and the anatomic reversibility of spinal cord insult.
PMID- 10685483
TI - Nonoperative treatment for lumbar spinal stenosis. Clinical and outcome results
and a 3-year survivorship analysis.
AB - STUDY DESIGN: A cohort study of nonoperatively treated patients with lumbar
spinal stenosis. OBJECTIVE: To assess the effectiveness of aggressive nonsurgical
treatment for lumbar spinal stenosis. BACKGROUND DATA: While surgical treatment
of lumbar spinal stenosis has been widely accepted, the natural history of this
condition is poorly documented. Moreover, the effect of other available therapies
is unclear. METHODS: Forty-nine patients meeting radiographic and clinical
criteria for spinal stenosis underwent nonsurgical intervention consisting of
therapeutic exercises, analgesics, and epidural steroid injections. Patients were
followed for an average of 33 months. Outcome was assessed using a recently
developed patient questionnaire for assessment of patients with lumbar spinal
stenosis. Survival analysis was used to assess the probability of surgical
intervention over the follow-up period. RESULTS: At 3 years following treatment,
9 of the 49 patients had undergone surgical intervention. Of the remaining 40
unoperated patients, it is reported that two suffered significant motor
deterioration, one of whom still reported overall symptoms as mild improvement,
and the other as definite worsening. Five of the 40 unoperated patients reported
feeling overall symptoms as probably or definitely worse, 12 reported no change,
11 reported only mild improvement, and 12 reported sustained improvement. Twelve
of the 40 unoperated patients also had none or only mild pain. CONCLUSIONS: The
authors conclude that aggressive nonoperative treatment for spinal stenosis
remains a reasonable option.
PMID- 10685484
TI - A three-dimensional radiographic comparison of Cotrel-Dubousset and Colorado
instrumentations for the correction of idiopathic scoliosis.
AB - STUDY DESIGN: A prospective clinical study comparing two instrumentation systems
for the correction of idiopathic scoliosis. OBJECTIVES: To measure the short-term
three-dimensional changes in the shape of the spine after corrective surgery and
compare the Cotrel-Dubousset instrumentation to the more recent Colorado
instrumentation to determine whether one system provides better three-dimensional
correction. SUMMARY OF BACKGROUND DATA: Adequate three-dimensional correction of
scoliotic deformities has been reported with the Cortrel-Dubousset
instrumentation system. During the past decade, a new generation of more
versatile and user-friendly spinal implants has appeared, but there are no
reports available to indicate whether similar or better correction can be
obtained with these newer systems. METHODS: The three-dimensional geometry of the
thoracic and lumbar spine was documented in the standing position using a three
dimensional reconstruction technique based on multiplanar radiography in 67
adolescents with idiopathic scoliosis undergoing correction by a posterior
approach. Changes in spinal shape were measured 3 days before and 1 month after
the surgery in 31 patients with Cotrel-Dubousset instrumentation and 36 patients
with Colorado instrumentation. RESULTS: In both groups, adequate three
dimensional correction of the scoliotic deformities was documented for thoracic
and lumbar curves, with significant changes in the frontal plane, in the plane of
maximum curvature, and in its orientation. When comparing both groups, better
correction was obtained in the frontal plane with the Colorado instrumentation
(65% vs. 48% with Cotrel-Dubousset), a finding that may be explained by the
significantly greater proportion of pedicle screws used in this group.
CONCLUSION: Both instrumentation techniques achieve an effective and comparable
three-dimensional correction of the scoliotic deformities.
PMID- 10685485
TI - The relationship between tight hamstrings and lumbar hypolordosis in children
with cerebral palsy.
AB - STUDY DESIGN: Retrospective clinical and radiographic review. OBJECTIVE: To
assess the influence of tight hamstrings on the sagittal alignment of the
thoracic and lumbar spine in children with cerebral palsy. SUMMARY OF BACKGROUND
DATA: It is postulated that tight hamstrings may produce a hypolordosis of the
lumbar spine. The abnormal sagittal contour of the spine may lead to increased
stresses in the lumbar spine and subsequent pain and disability. This is of
special concern in children with cerebral palsy who often have shortened spastic
hamstring muscles. METHODS: Twenty-one patients were evaluated, with a mean age
of 9.4 years. Standing and sitting lateral spine films were obtained and the
lumbar lordosis and thoracic kyphosis were measured using the Cobb method. The
popliteal angle was measured to assess hamstring tightness, such that a large
popliteal angle indicates tight hamstrings. RESULTS: We found a statistically
significant correlation between the sitting lumbar curve and popliteal angle
(Pearson correlation value -0.77, P < 0.01). As the popliteal angle increased,
the amount of lumbar lordosis decreased. This correlation was less significant
when the patient was standing (Pearson correlation value -0.59). CONCLUSION: This
study demonstrates that there is a correlation between tight hamstrings, as
measured by the popliteal angle, and decreasing lumbar lordosis, especially when
sitting.
PMID- 10685486
TI - A radiostereometric analysis of the movements of the sacroiliac joints in the
reciprocal straddle position.
AB - STUDY DESIGN: A Radiostereometric analysis of the reciprocal straddle position.
OBJECTIVES: To evaluate the magnitude of rotation in the sacroiliac joints in the
reciprocal straddle position. SUMMARY OF BACKGROUND DATA: The reciprocal straddle
position has been objectified in different studies, using different techniques,
to show a sacroiliac motion between 5 degrees and 36 degrees. Previous studies
with radiostereometric analysis during different provocations reported much
smaller movements. METHODS: Six women with posterior pelvic pain of long duration
after pregnancy (n = 5) and sacroiliitis (n = 1) underwent radiostereometric
analysis in the sustained reciprocal straddle position. RESULTS: A reciprocal
movement could be demonstrated in the sacroiliac joints in the reciprocal
straddle position. However, the movements were 10 times smaller than reported in
earlier studies of the reciprocal straddle position. CONCLUSIONS: It was possible
to demonstrate reciprocal movements of the sacroiliac joints in the straddle
position. However, the radiostereometric analysis technique showed the movements
to be small, as reported in other mobility studies.
PMID- 10685487
TI - A cross-sectional study correlating lumbar spine degeneration with disability and
pain.
AB - STUDY DESIGN: Cross-sectional design. OBJECTIVES: To investigate the correlation
between degeneration in the lumbar spine and self-reported disability and pain
levels in patients with and without a history of trauma. SUMMARY OF BACKGROUND
DATA: The link between lumbar spine degeneration and low back pain remains
controversial, as does the correlation between trauma and spinal degeneration.
METHODS: Radiographic and questionnaire data were collected from 172 consecutive
patients with low back pain. Back pain severity was measured using two scales:
one for pain over the entire episode and one for pain during the previous week.
All patients also completed the Revised Oswestry Disability Questionnaire before
radiography was performed. Further questions concerning the chronicity of
symptoms and trauma were included. RESULTS: Controlling for age, patients with
low back pain with a history of trauma had a statistically significant increase
in the severity of facet degeneration (P < 0.02) compared with nontrauma patients
with low back pain. However, there was no difference in disability and pain
scores between the trauma and nontrauma patients or between the genders. A weak
correlation between pain severity ratings and the number of levels of
degeneration and the severity of the degeneration at the disc and facets was
noted. CONCLUSIONS: Patients with low back pain with a history of trauma had more
severe facet arthrosis than do nontrauma patients with low back pain, but there
were no differences in pain and disability. There was a weak correlation between
the quantity and severity of lumbar degeneration with pain levels, but not with
disability scores. These findings are discussed in the light of recent reports
regarding the cervical spine.
PMID- 10685488
TI - Body weight and low back pain. A systematic literature review of 56 journal
articles reporting on 65 epidemiologic studies.
AB - STUDY DESIGN: A systematic review of the epidemiologic literature. OBJECTIVE: To
establish if body weight is truly associated with low back pain (LBP) and whether
the link may be causal. SUMMARY OF BACKGROUND DATA: Because obesity and LBP are
prevalent in western society, it is of interest to establish whether obesity can
induce LBP. METHODS: Fifty-six original research reports, reporting on 65 studies
published between 1965 and 1997, were systematically reviewed for the frequency
of positive associations between body weight and LBP. In addition, the presence
of positive findings was examined in relation to several study characteristics.
Based on these results, only studies emanating from the general population with a
sample size exceeding 3000 were included in the additional search for causality
using some of the classical Bradford-Hill criteria. The review was carried out by
the author, blindly at 2 months' interval. RESULTS: Thirty-two percent of all the
studies report a statistically significant positive weak association between body
weight and LBP. Studies that fulfilled the post hoc criteria never report a rate
ratio above 2, but there is possibly a positive biological gradient. These
studies had no information on temporality or reversibility and there was no
obvious consistency of findings. CONCLUSIONS: Due to lack of evidence, body
weight should be considered a possible weak risk indicator, but there is
insufficient data to assess if it is a true cause of LBP.
PMID- 10685489
TI - Results of a multimodal treatment program for patients with chronic symptoms
after a whiplash injury of the neck.
AB - STUDY DESIGN: A descriptive case series pre- and post-treatment design, including
a 6-month follow-up. OBJECTIVES: The objective of this study was to document the
improvements of patients with chronic symptoms after a "whiplash" injury of the
neck, who attended a 4-week multimodal treatment program at the Rug AdviesCentra
Nederland. SUMMARY OF BACKGROUND DATA: To the authors' knowledge, no studies have
been conducted on the effectiveness of multidisciplinary treatment of chronic
symptoms after whiplash injury. METHODS: Twenty-six patients who experienced
Quebec type 1 or 2 lesions of the neck (whiplash) with persisting symptoms of
longer than 6 months' duration participated in the study. The measures included
were pain intensity (according to the visual analog scale), number of painful
sites (determined by pain drawing), self-reported disability Quebec Back Pain
Disability Scale; and symptoms of somatic and psychological distress and
cognitive symptoms (according to selected Minnesota Multiphasic Personality
Inventory-2 scales). Furthermore, objective outcome criteria were used regarding
return to work, medication, and medical and paramedical treatment. Statistical
and clinical significance of treatment results were both assessed. RESULTS: The
patients' symptoms improved significantly on nearly all self-report measures.
Their scores for objective outcome criteria reported during the 6-month follow-up
evaluation were: complete return to work (65%); complete or partial return to
work (92%); no use of analgesics in the past 6 months (58%); and no medical or
paramedical treatments in the past 6 months (81%). CONCLUSION: These early
results indicate that a multimodal treatment program has the potential to be an
effective treatment for patients with chronic symptoms after a whiplash injury of
the neck--a group of patients who have in the past been considered intractable
or, at the very least, puzzling.
PMID- 10685490
TI - Repositioning error in low back pain. Comparing trunk repositioning error in
subjects with chronic low back pain and control subjects.
AB - STUDY DESIGN: Repositioning error of the trunk was tested in 20 subjects with
chronic low back pain and in 20 control subjects. The 3Space Tracker (Polhemus,
Colchester, VT), a device that measures three-dimensional position in space, was
used to determine the subject's trunk position. OBJECTIVES: To determine whether
repositioning error is different in subjects with chronic low back pain than in
control subjects. SUMMARY OF BACKGROUND DATA: Proprioception allows the body to
maintain proper orientation during static and dynamic activities. In peripheral
joint injuries, researchers have demonstrated a loss of some aspects of
proprioception and improvement in outcome with retraining. Although the
components of proprioception in subjects with low back pain have not been well
studied, it is thought that these persons lose some elements of proprioception
that can be measured in a quantifiable way. If so, then rehabilitation to improve
these deficits is important. In this pilot study, one aspect of proprioception,
repositioning error, was examined. METHODS: The subjects attempted to replicate
target positions of the trunk in flexion, extension, lateral bending, and lateral
rotation. Repositioning error was calculated as the absolute difference between
the actual and the subject-replicated target positions. RESULTS: No significant
difference was found in repositioning error between the control subjects and the
persons with chronic low back pain. CONCLUSIONS: Because proprioception is
complex and entails the use of many afferent receptors, it is difficult to
measure any one afferent deficiency discretely. The authors believe that this
study, in which one aspect of proprioception was measured in an indirect manner,
provides important background information on low back position sense. Further
studies analyzing aspects of proprioception in subjects with low back pain are
recommended.
PMID- 10685491
TI - Coordination of primary health care for back pain. A randomized controlled trial.
AB - STUDY DESIGN: A randomized controlled trial comparing usual care with a program
for the coordination of primary health care (CORE) for the treatment of subacute
low-back pain patients. OBJECTIVES: To measure the effectiveness of the CORE
program as a mean for implementing clinical practice guidelines for low-back pain
in an urban community. SUMMARY OF BACKGROUND DATA: Clinical practice guidelines
have been developed for primary care physicians and patients on the clinical
management of low-back pain. The implementation of the guidelines in a large
community is difficult with the multiplicity of medical and nonmedical back care
providers and products. The CORE program was designed to make the guidelines fit
in this complex environment. METHODS: One hundred ten workers compensated for low
back pain for 4 to 8 weeks in metropolitan Montreal were randomized in two
groups: usual care (N = 56) and the CORE program (N = 54). Coordination of
primary health care was performed by two primary care physicians and a nurse in
liaison with the treating physicians, and included a complete examination,
recommendations for the clinical management, and support to carry out the
recommendations. All workers were followed for 6 months. Back pain and functional
status were assessed at baseline, 3 months, and 6 months. RESULTS: In the 6-month
follow-up, the CORE group returned to work 6.6 days (standard error = 8.9)
quicker than the control group, a difference that was not statistically
significant. However, the CORE group showed a sustained improvement in pain and
functional status with two-fold differences at the end of the 6 months of follow
up. This represented nine points on the Oswestry scale (P = 0.02) and 12 points
on the Quebec Back Pain Disability Scale (P = 0.01). The CORE group also used
three times less specialized imaging tests of the spine at 3 months (P < 0.01)
and exercised twice as much at 6 months (P < 0.05) than the controls.
CONCLUSIONS: The therapeutic results for workers with low-back pain could be
improved by implementing the clinical practice guidelines with primary care
physicians in a large community, without delaying the return to work. The CORE
intervention for back pain patients is highly relevant to primary care practice.
It is simple in its application, flexible to accommodate physicians' and-
patients' preferences in health care, and it is effective on patients' clinical
outcome.
PMID- 10685492
TI - Endoscopic foraminotomy using MED system in cadaveric specimens.
AB - STUDY DESIGN: Four cadavers had cervical foraminotomies performed at
noncontiguous levels using either the standard open technique or the
microendoscopic technique. OBJECTIVES: To evaluate the feasibility of using a
minimally invasive technique for posterior decompression of cervical disc
disease. SUMMARY OF BACKGROUND DATA: Even though the anterior approach is more
commonly performed for the treatment of cervical disc disease, the posterior
approach has distinct advantages in selected cases of foraminal stenosis and
posterolateral disc herniation. Current technique, however, requires extensive
muscle dissection, and is, therefore, subject to significant morbidity. METHODS:
Each of four cadavers had posterior cervical foraminotomies performed using
either the MICROENDOSCOPIC (MED) technique, or the standard open technique. Three
noncontiguous levels were decompressed using one technique, and the other
technique was used for the adjacent contralateral decompression. Each specimen
was then evaluated with postoperative myelogram/CT and open dissection.
Laminotomy size, length of root decompressed, and percentage of facet removed
were measured. RESULTS: Average vertical diameter decompression and percentage of
facet removed were significantly greater for the MED technique than for the open
technique. Transverse diameter of the laminotomy area and the average length of
decompressed root were not significantly different between the techniques.
CONCLUSION: Posterior cervical foraminotomy, using the microendoscopic technique,
is technically feasible and may be applicable to the treatment of foraminal
stenosis and laterally located cervical disc herniation. Studies in live animals
are currently examining techniques for hemostasis.
PMID- 10685493
TI - Posterior spinal instrumentation and fusion of a neuromuscular scoliosis in a
patient with autosomal dominant osteopetrosis.
AB - STUDY DESIGN: A case report of a patient with autosomal dominant osteopetrosis
and neuromuscular scoliosis who required surgical instrumentation and fusion of
her spine. OBJECTIVE: To illustrate the surgical technique and long-term outcome
in this rare form of spinal deformity. SUMMARY OF BACKGROUND DATA: Osteopetrosis
is a group of rare skeletal dysplasias characterized clinically by skeletal
osteosclerosis that is classically described in appearance as "marble bone."
Despite the ubiquitous involvement of the vertebra, clinical manifestations of
spinal involvement are uncommon. We present the case of an osteopetrotic patient
with neuromuscular scoliosis who required surgical correction of her progressive
deformity. There are no prior reports in the literature concerning operative or
nonoperative management of scoliosis in this patient population. METHODS: The
surgical technique utilized as well as the patient's response to surgical
management of her scoliosis is presented with 5 year follow-up. RESULTS: The
patient underwent a successful T4 to L1 posterior spine fusion and
instrumentation using Luque rods, sublaminar wires and allograft bone
augmentation. At 5 years following her index procedure, she is clinically and
radiographically fused. CONCLUSION: Patients with osteopetrosis present unique
surgical challenges during surgical correction of spinal deformities. The use of
segmental sublaminar wires with 1/4-inch rods and crosslinks afforded stable
fixation despite poor bone quality. Allograft bone combined with postoperative
bracing resulted in a well-maintained correction and a solid fusion. Five year
follow-up and continued radiographic evidence of stable fusion indicate that the
presented approach can lead to a successful outcome in the osteopetrotic patient
population.
PMID- 10685494
TI - Giant cauda equina schwannoma. A case report.
AB - STUDY DESIGN: Case report. OBJECTIVES: To present a rare case of a giant
schwannoma of the cauda equina. SUMMARY OF BACKGROUND DATA: Giant spinal
schwannoma of the cauda equina, which involves many nerve roots, is rare and
there is usually no ossification in the schwannoma. It is unknown whether or not
complete excision is preferable if the tumor is located in the lumbar lesion.
METHODS: A 57-year-old woman had a 10-year history of low back pain. Scalloping
of the posterior surface of the vertebral bodies from L3 to the sacrum was found.
Magnetic resonance imaging disclosed a giant cauda equina tumor with multiple
cysts. Central ossification revealed by computed tomography and an unusual
myelogram made the preoperative diagnosis difficult. RESULTS: The patient
underwent incomplete removal of the tumor, decompression of cysts, and spinal
reconstruction. The tumor was proved to be a schwannoma. The postoperative course
was uneventful and she has been almost free from low back pain for 3 years and 4
months. CONCLUSIONS: Giant schwannoma in the lumbar spine region is usually
excised incompletely, because complete removal had the risk of sacrificing many
nerve roots. In spite of the incomplete removal of the tumor, the risk of
recurrence is low.
PMID- 10685495
TI - Persistent osteopenia in adolescent idiopathic scoliosis: a longitudinal follow
up study.
PMID- 10685496
TI - Re: The graf ligamentoplasty procedure. Comparison with posterolateral fusion in
the management of low-back pain.
PMID- 10685497
TI - Synthesis of 6-aryloxy- and 6-arylalkoxy-2-chloropurines and their interactions
with purine nucleoside phosphorylase from Escherichia coli.
AB - The phase transfer method was applied to perform the nucleophilic substitution of
2,6-dichloropurines by modified arylalkyl alcohol or phenols. Since under these
conditions only the 6-halogen is exchanged, this method gives 2-chloro-6-aryloxy-
and 2-chloro-6-arylalkoxy-purines. 2-Chloro-6-benzylthiopurine was synthesized by
alkylation of 2-chloro-6-thiopurine with benzyl bromide. The stereoisomers of 2
chloro-6-(1-phenyl-1-ethoxy)purine were obtained from R- and S-enantiomers of
sec.-phenylethylalcohol and 2,6-dichloropurine. All derivatives were tested for
inhibition with purified hexameric E. coli purine nucleoside phosphorylase (PNP).
For analogues showing IC50 < 10 microM, the type of inhibition and inhibition
constants were determined. In all cases the experimental data were best described
by the mixed-type inhibition model and the uncompetitive inhibition constant,
Kiu, was found to be several-fold lower than the competitive inhibition constant,
Kic. This effect seems to be due to the 6-aryloxy- or 6-arylalkoxy substituent,
because a natural PNP substrate adenine, as well as 2-chloroadenine, show mixed
type inhibition with almost the same inhibition constants Kiu and Kic. The most
potent inhibition was observed for 6-benzylthio-2-chloro-, 6-benzyloxy-2-chloro-,
2-chloro-6-(2-phenyl-1-ethoxy), 2-chloro-6-(3-phenyl-1-propoxy)- and 2-chloro-6
ethoxypurines (Kiu = 0.4, 0.6, 1.4, 1.4 and 2.2 microM, respectively). The R
stereoisomer of 2-chloro-6-(1-pheny-1-ethoxy)purine has Kiu = 2.0 microM, whereas
inhibition of its S counterpart is rather weak (IC50 > 12 microM). More rigid
(e.g. phenoxy-), non-planar (cyclohexyloxy-), or more bulky (2,4,6
trimethylphenoxy-) substituents at position 6 of the purine base gave less potent
inhibitors (IC50 = 26, 56 and > 100 microM, respectively). The derivatives are
selective inhibitors of hexameric "high-molecular mass" PNPs because no
inhibitory activity vs. trimeric Cellulomonas sp. PNP was detected. By
establishing the ligand-dependent stabilization pattern of the E. coli PNP it was
shown that the new derivatives, similarly as the natural purine bases, are able
to form a dead-end ternary complex with the enzyme and orthophosphate. It was
also shown that the derivatives are substrates in the reverse synthetic direction
catalyzed by E. coli PNP.
PMID- 10685498
TI - Bleomycin-induced DNA damage and DNA repair in chicken embryo cells as compared
to X-irradiation.
AB - Following in vitro- and in ovo-exposure of chicken embryo cells, the level of
bleomycin (BM)-induced damage was evaluated by using DNA synthesis, nucleoid
sedimentation (SED), and viscometry of alkaline cell lysates (VISC). This damage
was compared to X-irradiation, using 5.9-378 nM BM in vitro, 1.5-116 micrograms
BM/egg in ovo, and 2-32 Gy, respectively, in vitro as well as in ovo. With
respect to BM, the most notable result is the increase in DNA synthesis and VISC
at the lowest concentrations of the drug. A decrease in both parameters was
observed at high BM concentrations and following exposure to X-rays,
concomitantly with an increase in SED. Regarding the radiomimetic drug BM and X
rays, different modes of DNA damage and DNA repair are suggested by previous
investigations and the present results. Therefore, further evidence is presented,
that the chicken embryo can act as a simple, rapid and inexpensive test system to
characterize the biological effects of many nucleo- and/or cytotoxic agents.
PMID- 10685499
TI - 1H-cyclopenta[b]benzofuran lignans from Aglaia species inhibit cell proliferation
and alter cell cycle distribution in human monocytic leukemia cell lines.
AB - Thirteen naturally occurring 1H-cyclopenta[b]benzofuran lignans of the
rocaglamide type as well as one naturally occurring aglain congener all of them
isolated from three Aglaia species (Aglaia duperreana, A. oligophylla and A.
spectabilis) collected in Vietnam were studied for their antiproliferative
effects using the human monocytic leukemia cell lines MONO-MAC-1 and MONO-MAC-6.
Only rocaglamide type compounds showed significant inhibition of [3H-]thymidine
incorporation and the most active compound didesmethylrocaglamide inhibited cell
growth in a similar concentration range as the well-known anticancer drug
vinblastine sulfate. Detailed structure-activity analysis indicated that the OH
group at C-8b which is a common structural feature of most naturally occurring
rocaglamide compounds is essential for the described antiproliferative activity
since replacement of this group by methylation led to a complete loss of the
inhibitory activity for the resulting derivative. Rocaglamide derivatives rapidly
inhibited DNA as well as protein biosynthesis of MONO-MAC-6 cells at
concentrations well below those of actinomycin D or cycloheximide which were used
as positive controls in the respective experiments. Didesmethylrocaglamide was
furthermore able to induce growth arrest of MONO-MAC-1 cells in the G2/M and
probably G0/G1-phase of the cell cycle with no morphological indication of
cellular damage. Our data suggests that 1H-cyclopenta[b]benzofuran lignans of the
rocaglamide type act primarily by a cytostatic mechanism.
PMID- 10685500
TI - Carboxymethylated glucan inhibits lipid peroxidation in liposomes.
AB - Protective capabilities were studied of carboxymethylated (1-->3)-beta-D-glucan
from Saccharomyces cerevisiae cell wall against lipid peroxidation in
phosphatidylcholine liposomes induced by OH radicals produced with Fenton's
reagent (H2O2/Fe2+) and also by microwave radiation using absorption UV-VIS
spectrophotometry. A significant decrease in the conjugated diene production,
quantified as Klein oxidation index, was observed in the presence of a moderate
amount of added glucan. Increase of the oxidation index was accompanied with
enhanced carboxyfluorescein leakage as a result of liposome membrane
destabilization. This process was markedly suppressed with glucan present in the
liposome suspension. Therefore, glucan may be considered as a potent protector
against microwave radiation-induced cell damage.
PMID- 10685501
TI - The anticancer drug chlorambucil interacts with the human erythrocyte membrane
and model phospholipid bilayers.
AB - The plasma membrane has gained increasing attention as a possible target of
antitumor drugs. It has been reported that they act as growth factor antagonists,
growth factor receptor blockers, interfere with mitogenic signal transduction or
exert direct cytotoxic effects. Chlorambucil (4-[p-(bis[2
chloroethyl]amino)phenyl]butyric acid) is an alkylating agent widely used in the
treatment of chronic lymphocytic leukaemia. Contradictory reports have been
published concerning its interaction with cell membranes. Whereas a decrease in
the fluidity of Ehrlich ascite tumor cells has been adduced, no evidences were
found that chlorambucil changes membrane lipid fluidity and alkylating agents had
effects in these systems even at highly toxic concentrations. Our results showed
that chlorambucil at a dose equivalent to its therapeutical concentration in the
plasma (3.6 microM) caused the human erythrocyte membrane to develop cup-shaped
forms (stomatocytes). Accordingly to the bilayer couple hypothesis, this means
that the drug is inserted into the inner monolayer of the erythrocyte membrane, a
conclusion supported by X-ray diffraction performed on multilayers of
dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine
(DMPE), representative of phospholipid classes located in the outer and inner
monolayers of the erythrocyte membrane, respectively. It is concluded that the
cytotoxic effect of chlorambucil might be due to alteration of the structure and
therefore of the physiological properties of cell membranes such as fluidity,
permeability, receptor and channel functions.
PMID- 10685502
TI - The activity of thymidine phosphorylase correlates with tumor size and lymph
nodes status in breast carcinoma.
AB - The platelet-derived endothelial cell growth factor (PD-ECGF) is one of the
potent angiogenic factors. Recently, its homology with thymidine phosphorylase
(dThdPase), an enzyme involved in pyrimidine nucleoside metabolism, has been
shown. In the present study, dThdPase activity was evaluated
spectrophotometrically in 43 breast carcinomas and in 19 cases of non-neoplastic
breast tissues. The mean dThdPase activity in breast cancer was almost six fold
higher than in normal, non-neoplastic breast tissues (1.92 and 0.29 mumol thymine
(T) x mg prot.-1 x h-1 respectively). The enzyme activity significantly
correlated with axillary lymph node status (p = 0.0076) and with tumor size (p =
0.0099). Besides, the intratumoral microvessel density (MD) was evaluated using
the CD 31 mouse anti-human monoclonal antibody, and there was no correlation
between the level of enzymatic activity and a number of microvessels. The
positive significant correlation of thymidine phosphorylase activity with
prognostic factors in breast cancer patients with no relation to the number of
microvessels needs further examination to confirm the prognostic significance of
the level of dThdPase.
PMID- 10685503
TI - Scaling of some metabolic enzymes in liver of a freshwater teleost: an adaptive
mechanism.
AB - The activities of mitochondrial malate dehydrogenase (mMDH) and the total
mitochondrial proteins increase as a function of body mass in the freshwater
catfish, Clarias batrachus. It clearly indicates an increase in energy production
in larger-sized individuals for various purposes including prey-predator
interactions. The higher activity of lactate dehydrogenase (LDH) in larger fish
may indicate more production of lactate for gluconeogenesis in the liver to meet
emergency requirements of increased energy demand. However, the activity of
cytoplasmic malate dehydrogenase (cMDH) decreases with the increasing body mass
of the fish which reflects reduction in NADPH production and, in turn, reduced
lipogenesis in liver of larger individuals. Thus, the present observations
suggest an adaptive mechanism dealing with the higher energy budget, and reduced
synthetic activities (lipogenesis) in the liver of larger-sized freshwater
catfish. This type of biochemical scaling might be also supporting other
metabolic pathways in order to adjust some physiological functions for survival
in the aquatic environment.
PMID- 10685504
TI - Contribution of a metal-peroxide adduct to neurodegeneration is due to its
oxidative protease activity.
AB - Many hypotheses have been developed to explain aging and age-related
neurodegenerative disorders; one of the most compelling is the role of oxidative
stress to induce changes in protease activity in brains of patients of
Alzheimer's disease and prion disease. At the moment however, there is no clear
answer how protein degradation may be achieved in the brain. We have observed
that several metal compounds can degrade proteins in the presence of hydrogen
peroxide, and elucidated the reaction scheme based on the new theoretical point
for the reactivity of a metal-peroxide adduct with eta 1-coordination mode. In
this article we would like to point out the importance of a copper(II)-peroxide
adduct to promote neurodegenerative diseases such as prion disease and
amyotrophic lateral sclerosis through its oxidative protease function.
PMID- 10685505
TI - Androconial hairbrushes of the Syntomis (Amata) phegea (L.) group (Lepidoptera,
Ctenuchinae): a synapomorphic character supported by sequence data of the
mitochondrial 16S rRNA gene.
AB - Males of several palaearctic Syntomis/Amata species (Lepidoptera: Arctiidae)
possess androconial hairbrushes in connection with the foreleg coxa. The
cuticular structure of these potentially behaviour-related and pheromone
dissipating brushes is described. Such male-specific organs and signals play a
crucial role in the female choice procedure. The presence of hairbrushes was
found in 17 out of 28 inspected species of the tribe Syntomini. All members of
the Syntomis phegea group (Europe to Central Asia, as well as Caspian, Caucasian
and near-middle East species) have these structures, and only three oriental and
south Asian, but none of three African species, carry this trait. The common
genetic base of this morphological character is supported by an analysis of
mitochondrial 16S rRNA from 19 representative taxa; species with hairbrushes form
a monophyletic clade and the brushes are a synapomorphic character. This genetic
finding corroborates the ethological significance of these organs. Phylogenetic
data show a substantial genetic divergence between the tribe Ctenuchini (New
World species) and the Old World Syntomini. Furthermore, DNA sequence data
suggest a split of the genus Amata (sensu Obraztsov, 1966) in two distinct
genera, Amata (without hairbrushes) and Syntomis (with hairbrushes).
PMID- 10685506
TI - Flavonoids and terpenoids from Luma gayana (Barn.) Burret.
AB - The flavonoids 5-hydroxy-7-methoxyflavanone, 6,8-dimethyl-5,7-dihydroxyflavanone
and 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone, a mixture of alkyl esters
of p-coumaric acid, the triterpenoids oleanolic acid and maslinic acid, the
monoterpenoid 1 alpha,2 beta,4 beta-trihydroxy-p-menthane, the sesquiterpenoid
clovandiol and beta-sitosterol were isolated from the aerial parts of Luma gayana
(Barn.) Burret. This is the first report on the chemistry of this species.
PMID- 10685507
TI - Possible involvement of beta-adrenergic receptors in the enhancement of nocturnal
pineal N-acetyltransferase activity due to parathion administration.
AB - The purpose of the present study was to examine the effects of administration of
sublethal doses of O,O-diethyl-O-p-nitrophenyl phosphorothioate (parathion) on
serum epinephrine (EPI) and norepinephrine (NE), as well as on night-time rat
pineal melatonin synthesis, both in the presence and absence of propranolol, a
beta-adrenergic receptor antagonist. In the first experiment, two groups of adult
albino rats were administered parathion orally (1.08 and 2.17 mg/kg/day; the
total received by each animal was 6.5 and 13.0 mg/kg body weight over 6 days);
another two groups received corn oil only. Animals were killed at 23:00 and 01:00
h by decapitation. Serum EPI was augmented at 01:00 h, but NE was increased at
01:00 and 23:00 h due to administration of the high dose of parathion (13 mg/kg).
In the second experiment, two groups of adult male albino rats were administered
parathion orally (13 mg/kg); another two groups received an intraperitoneal
injection of propranolol (20 mg/kg body weight, 1 h before the lights were turned
off). In addition, two groups were given a saline injection. Four hours after
darkness onset, pineal N-acetyltransferase (NAT) activity as well as pineal and
serum melatonin levels were measured. Parathion by itself significantly augmented
nocturnal pineal NAT activity and serum melatonin levels in otherwise untreated
rats; the insecticide was ineffective in reference to this enzyme when it was
given in conjunction with the beta-adrenergic receptor antagonist propranolol.
The augmentation of NAT activity by parathion also caused significant reduction
in pineal serotonin (5-HT); again, this response was blocked by propranolol
treatment. The results are consistent with the idea that parathion influences
pineal 5-HT metabolism either at the level of the beta-adrenergic receptor or via
the sympathetic innervation to the pineal gland.
PMID- 10685508
TI - Hepatotoxicity of tetrabromobisphenol-A: effects of repeated dosage in rats.
AB - Tetrabromobisphenol-A (TBBP-A) is used as a reactive flame retardant and as an
intermediate in the production of other flame-retardants. In our study, TBBP-A
was administered intragastrically, daily for 7 or 7-28 days at three dose levels.
Significant changes of biochemical indicators were noted with regard to
glutathione (GSH), malondialdehyde (MDA) and 5-aminolevulinate dehydratase (ALA
D). The level of GSH was lowered by the two higher doses (female rats only) and
MDA was elevated by the highest dose (male rats only). The ALA-D activity reacted
in opposite directions for both sexes. Other indicators did not yield any
conclusive results. The 28-day study was performed on female rats. For GSH and
MDA the medium dose resulted in a systematic increase. Insignificant changes in
ALA-D activity in the liver were observed throughout the experiment. The activity
of 5-aminolevulinate synthase had a decreasing tendency at 250 mg/kg of TBBP-A
during the whole time of observation. Other general indices such as the activity
of gamma-glutamyltransferase, concentration of microsomal proteins and the level
of cytochrome P-450 did not show any significant changes. The most pronounced
changes were noted with regard to indicators of porphyrogenic action. The results
suggest that TBBP-A is capable of disturbing the heme metabolism in rats.
PMID- 10685509
TI - Effect of dietary aluminum on tissue nonheme iron and ferritin levels in the
chick.
AB - Aluminum toxicity is well documented but the mechanism of action is poorly
understood. In renal failure patients with aluminum overload, disturbances in
iron metabolism leading to anemia are apparent. Few animal models, however, have
been used to study the effects of dietary aluminum on iron metabolism. The
purpose of this study was to determine if dietary aluminum exposure alters tissue
iron and ferritin concentrations in the chick, as has been found in cultured
human cells exposed to aluminum. Groups of day-old chicks were fed purified diets
containing one of two levels of iron (control or high iron), and one of three
levels of aluminum chloride in a 2 x 3 factorial design. Diets were consumed ad
libitum for 1 week, then pair-feeding was initiated for 2 more weeks. A seventh
group consumed a low iron diet ad libitum for comparative purposes. After the 3
week feeding period, samples of kidney, liver, and intestinal mucosa were
analyzed for nonheme iron and ferritin concentrations by a colorimetric assay and
SDS-PAGE, respectively. Results showed that dietary aluminum intake reduced iron
stores in liver and intestine, but had no effect on nonheme iron levels in the
kidney. Ferritin levels were reduced by aluminum intake in all tissues studied.
The decreases in tissue ferritin levels were proportionately more than the
decreases in tissue nonheme iron levels. This resulted in increased nonheme iron
to ferritin ratios that amounted to as much as 140 and 525% in kidney and
intestine, respectively. These findings are consistent with the interpretation
that, in the growing chick, dietary aluminum can inhibit iron absorption, disrupt
the regulation of tissue ferritin levels by iron, and potentially alter the
compartmentalization and protective sequestration of iron within cells.
PMID- 10685510
TI - Chromium increases pancreatic metallothionein in the rat.
AB - The ability of chromium (Cr) salts to increase metallothionein (MT) levels in rat
liver, kidney and pancreas, and its relationship with the presence of toxic
effects are reported here. Rats were injected subcutaneously with 0, 10, 20, 30,
40, or 50 mg K2Cr2O7/kg and sacrificed 24 h later. Total Cr accumulation followed
a dose-dependent pattern, levels in kidney being higher than those in liver or
pancreas, suggesting different tissue bioavailabilities and accumulation
patterns. Cr(IV) administration resulted in a tissue-specific MT induction:
pancreas and liver showed five- and 3.5-fold MT increases, respectively; no
increase was observed in the kidney. A positive correlation was observed between
zinc and MT concentrations in liver, and between total Cr and MT concentrations
in pancreas. Serum alpha-amylase activity showed a dose-dependent increase
starting from 20 mg/kg, whereas serum glucose levels increased at doses higher
than 30 mg/kg. Serum aspartate aminotransferase and alanine aminotransferase
activities were increased in a dose-dependent manner, from 20 and 30 mg/kg,
respectively. Our results showed that treatment with Cr(VI) can induce MT
synthesis in pancreas and suggests a subsequent binding of Cr to MT. Also,
pancreas is a target organ for Cr toxicity, and the usefulness of alpha-amylase
activity as a sensitive biomarker of Cr toxicity in human exposed populations
merits further study.
PMID- 10685511
TI - The effect of vitamin E exposure on cadmium toxicity in mouse embryo cells in
vitro.
AB - Heavy metals such as cadmium pose a number of environmental problems in addition
to being detrimental to human health. Cadmium is known to be embryotoxic in
animal models and to cause brain, limb and craniofacial malformations. Among
numerous mechanisms proposed for cadmium toxicity are oxidative stress and lipid
peroxidation. Vitamin E has been found to have antioxidant and cytoprotective
properties in cultured cells but its effect on cadmium embryonic toxicity has not
yet been determined. Epithelial-like cells derived from day-8 whole-mouse embryos
were used as a model embryonic tissue. Cadmium toxicity in these cultured cells
was found to be both time and concentration dependent. Prior exposure to 50
microM alpha-tocopherol or 25 or 50 microM alpha-tocopherol acetate resulted in a
marked reduction in the toxicity of 5 microM CdCl2. The apparent cytoprotective
effects may be partly non-specific, however, as a general growth enhancement was
observed after vitamin E exposure in the absence of cadmium.
PMID- 10685512
TI - Differential sensitivities of MRP1-overexpressing lung tumor cells to cytotoxic
metals.
AB - The human multidrug-resistance protein (MRP1), known to mediate cellular efflux
of a wide range of xenobiotics, including anticancer drugs, has also been shown
to transport antimony, thereby conferring resistance to this heavy metal. The aim
of the present study was to investigate whether other cytotoxic metals could be
handled by MRPI using MRP1-overexpressing lung tumor GLC4/Sb30 cells. Such cells
were found to be 3.4-, 12.7- and 16.3-fold more resistant than parental GLC4
cells to mercuric ion, arsenite and arsenate, respectively, whereas they remained
sensitive to other cytotoxic metals tested such as copper, chromium, cobalt or
aluminium. MK571, a potent inhibitor of MRP1 activity, almost totally reversed
resistance of GLC4/Sb30 cells to mercuric ions and arsenic while it did not
significantly alter sensitivity of GLC4 cells to metals. Arsenate-treated
GLC4/Sb30 cells were found to poorly accumulate arsenic through increased MK571
inhibitable efflux of the metal. Arsenate, however, failed to alter MRP1-mediated
transport of known MRP1 substrates such as calcein and vincristine. In
conclusion, these findings demonstrated that MRP1 likely handled some, but not
all, cytotoxic metals such as arsenic and mercuric ions in addition to antimony,
therefore resulting in reduced toxicity of these compounds towards MRP1
overexpressing cells.
PMID- 10685513
TI - Early hepatic changes in rats induced by permethrin in comparison with DDT.
AB - In this study permethrin [(3-phenoxyphenyl)-methyl-3-(2,2-dichloroethenyl)-2,2
dim ethylcyclopropanecarboxylate] and DDT [1,1-(2,2,2 trichloroethylidene)-bis-(4
chlorobenzene)] were compared in rats for their effects on early hepatic changes,
proposed in the literature to be useful endpoints in screening for non-genotoxic
hepatocarcinogenesis and/or liver tumour promotion. We compared the effects of
both insecticides on the following endpoints: hepatomegaly, mitogenesis (DNA
synthesis, mitotic activity, percentage of binuclear cells) and liver pathology.
Male Wistar rats received permethrin (PERM) or DDT in one, three, five and 14
daily oral doses (at 24-h intervals) equivalent to 1/10 LD50. Distinct
differences in early liver response between PERM and DDT were observed. DDT
stimulated the early effect consisting of hepatomegaly accompanied by an increase
in hepatocellular proliferation with signs of cell necrosis. Thus, it might be
concluded, that the mitogenic effect of DDT was at least partly related to a
regenerative liver response. Although PERM significantly affected DNA synthesis
and increased binuclear hepatocytes, this compound did not increase the number of
mitotic figures. These results suggest that PERM may inhibit of phase G2 in the
cell cycle and consequently it may suppress the cell entering into the stage of
mitosis (M-phase). In addition, the present findings provide evidence for the
occurrence of abnormal mitoses in the hepatocytes of rats treated with DDT.
PMID- 10685514
TI - Flow cytometry as a tool to monitor the disturbance of phagocytosis in the clam
Mya arenaria hemocytes following in vitro exposure to heavy metals.
AB - The effectiveness of toxicology biomonitoring programs could be improved by the
addition of sensitive biomarkers. In this study the cell viability and
sensitivity of phagocytic function of phagocytes from bivalves (Mya arenaria) to
selected heavy metals were measured by flow cytometry, a novel approach.
Hemocytes (phagocytes) collected from bivalves by puncture of the posterior
adductor muscle were incubated in vitro for 18 h in hemolymph containing 10(-9)
10(-3)M of cadmium chloride, zinc chloride, mercuric chloride, methylmercury
chloride or silver nitrate, before determining their capacity to phagocytose
fluorescent latex beads by flow cytometry. Heterogeneity of the hemocyte cell
population was determined by forward scatter (FSC) and side scatter (SSC)
cytometric profile which showed two distinct cell populations. At low doses (10(
9), 10(-8) M), all the metal compounds studied stimulated phagocytic activity
except silver nitrate. At higher levels of exposure (10(-6), 10(7) M), all metals
caused a significant concentration-related decrease in hemocyte phagocytosis
activity. From the concentration of each metal inducing 50% suppression (IC50) of
the phagocytic activity, the immunotoxic potential of metals with respect to
phagocytic function can be ranked in the following increasing order: ZnCl2 <
CdCl2 < AgNO3 < HgCl2 < CH3HgCl. Parallel analysis of hemocyte viability showed
that suppression of phagocytosis by heavy metals was not solely related to a
decreased cell viability. These results reveal the high but different degree of
sensitivity of the phagocytosis activity of bivalves with respect to heavy
metals, as measured by flow cytometry, and demonstrate that flow cytometry is a
potentially useful tool in ecotoxicological monitoring.
PMID- 10685515
TI - Role of vaginal sonography and hysterosonography in the endoscopic treatment of
uterine myomas.
AB - OBJECTIVE: To summarize the advantages and disadvantages of the various imaging
techniques used to evaluate uterine leiomyomas preoperatively and to propose a
classification system for intramural and subserosal leiomyomas that may better
serve the endoscopist in surgical treatment. DESIGN: A MEDLINE search of the
available literature was performed. CONCLUSION(S): Selective use of the various
imaging techniques is required based on the clinical situation. Classification
systems that describe the degree of myometrial involvement are needed for
appropriate case selection and counseling by the endoscopist.
PMID- 10685516
TI - Altered gene expression and secretion of interleukin-6 in stromal cells derived
from endometriotic tissues.
AB - OBJECTIVE: To compare the expression of interleukin-6 (IL-6) in endometrial and
endometriotic cells. DESIGN: Prospective study. SETTING: Department of Obstetrics
and Gynecology, Tottori University Hospital, Yonago, Japan. PATIENT(S): Twenty
patients who underwent either hysterectomy or laparoscopic surgery.
INTERVENTION(S): Endometrial and endometriotic stromal cells were obtained from
normal endometrium and from chocolate cyst linings of the ovary. Peritoneal
macrophages were isolated from peritoneal fluids. Cells were cultured in the
presence or absence of tumor necrosis factor-alpha. MAIN OUTCOME MEASURE(S): Gene
expression of IL-6 was examined by Northern blot analysis. Interleukin-6 protein
production was examined by immunocytochemical staining and ELISA. RESULT(S): A
single IL-6 messenger RNA band of approximately 1.3 kilobases was detected in
endometriotic stromal cells. Tumor necrosis factor-alpha increased the expression
of IL-6 messenger RNA in endometriotic cells in a dose-dependent manner. In
endometrial stromal cells, IL-6 messenger RNA signals were much weaker.
Endometriotic stromal cells produced significantly larger amounts of IL-6
compared with endometrial stromal cells under basal conditions and after
stimulation with tumor necrosis factor-alpha. Interleukin-6 protein was detected
in cells isolated from endometriotic tissues by immunocytochemical staining.
Interleukin-6 production by cultured macrophages from patients with endometriosis
and endometriotic stromal cells was comparable. CONCLUSION(S): Altered gene
expression and protein secretion of IL-6 in patients with endometriosis may
contribute to the pathogenesis of the disease and/or to endometriosis-associated
infertility.
PMID- 10685517
TI - Interleukin-6: another piece of the endometriosis-cytokine puzzle.
PMID- 10685518
TI - Embryo donation programs and policies in North America: survey results and
implications for health and mental health professionals.
AB - OBJECTIVE: To use survey results from Society of Assisted Reproductive Technology
to describe program policies regarding embryo donation, report protocols used for
the disposition of cryopreserved embryos, and discuss clarification of guidelines
governing ethical and psychosocially informed embryo donation. METHOD(S): A 66
item questionnaire was sent to the 312 Society of Assisted Reproductive
Technology programs, generating 108 responses. RESULT(S): Seventy-eight (72%) of
108 programs offer embryo donation. Forty (37%) have actually performed donation,
with 246 cycles completed and 53 "take-home babies." Disposition agreements for
donors address divorce (92%) and death (90%). Only 28% require that potential
donors undergo psychologic evaluation. Ninety-five percent of programs do not
compensate donors. Seventy-one percent require a complete medical and psychologic
history and 10% require genetic karyotyping. Three percent limit the number of
donations. Eligible recipients include married couples (100%), unmarried couples
(61%), lesbian couples (55%), and single women (59%). Sixty-four percent of
programs require psychologic screening. Storage limits range from 2-10 years.
Forty-nine percent of programs have unclaimed embryos in storage. CONCLUSION(S):
Embryo donation is more often contemplated than performed. Variability in program
procedures and policies suggests that guidelines need to be clarified. The
complexity of the psychosocial and ethical issues underscores the importance of a
routine, comprehensive psychologic assessment.
PMID- 10685519
TI - Semen quality of workers occupationally exposed to hydrocarbons.
AB - OBJECTIVE: To determine whether occupational exposure of men to hydrocarbons has
adverse effects on the quality of their semen. DESIGN: Comparative study.
SETTING: The rubber industry in Mexico City. PATIENT(S): Forty-eight workers who
were exposed to hydrocarbons for 2-24 years and 42 unexposed workers.
INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Environmental hydrocarbon
concentrations were determined by continuous air monitoring in all areas of the
factory. Analyses of semen samples were performed in accordance with World Health
Organization criteria. RESULT(S): Hydrocarbon concentrations were as follows:
ethylbenzene, 220.7-234 mg/m3; benzene, 31.9-47.8 mg/m3; toluene, 189.7-212.5
mg/m3; and xylene, 47-56.4 mg/m3. The number of subjects with ejaculates that had
normal characteristics was greater in the unexposed group (76%) than in the
exposed group (17%). More abnormal characteristics were found in the semen of
exposed workers than unexposed workers, including alterations in viscosity,
liquefaction capacity, sperm count, sperm motility, and the proportion of sperm
with normal morphology. Some abnormal characteristics correlated with the number
of years of exposure to the hydrocarbons. CONCLUSION(S): Damage to the
spermatogenic process resulting from hydrocarbon exposure was demonstrated by an
increased rate of abnormalities in the semen of exposed workers compared with
unexposed workers. This information may be useful for conducting future analyses
of reproductive risks related to exposure to high concentrations of hydrocarbons.
PMID- 10685520
TI - Antisperm autoantibody response is reduced by early repair of a severed vas
deferens in the juvenile rat.
AB - OBJECTIVE: To determine whether antisperm autoantibody production after
prepubertal vas injury is influenced by immediate repair of the vas compared to
delay of the reanastomosis until sexual maturity. DESIGN: Animal study comparing
early repair, late repair, and sham-operated groups. SETTING: Research laboratory
in a medical school. PATIENT(S): Lewis rats. INTERVENTION(S): After division of
the vas deferens in juvenile rats, animals in an early repair group had the vasa
repaired immediately by using an absorbable intraluminal stent. Animals in a late
repair group had vasa obstructed by ligation until after puberty, when they
underwent microsurgical vasovasostomy (age 60 days). MAIN OUTCOME MEASURE(S):
Antisperm antibodies were assayed by ELISA. The weights of reproductive organs
were determined, and samples of testis were studied by light microscopy.
RESULT(S): The antisperm antibody response was less when the vas was repaired
immediately than if the repair was delayed until after puberty. There was a low
incidence of testicular alteration in the repair groups and none in sham-operated
animals. CONCLUSION(S): If the vas deferens is injured or obstructed
prepubertally, there may be a benefit to considering immediate repair to reduce
the likelihood of developing antisperm autoantibodies, which have been associated
with reduced fertility.
PMID- 10685521
TI - Effect of vasovasostomy on contralateral testicular damage associated with
unilateral vasectomy in mature and immature Lewis rats.
AB - OBJECTIVE: We sought to determine if laser-assisted vasovasostomy could reverse
the contralateral histologic testicular changes associated with unilateral
vasectomy. DESIGN: A prospective, randomized, blinded, controlled study. SETTING:
Animal microsurgical laboratory, St. John's Mercy Medical Center, St. Louis,
Missouri. PATIENT(S): Twenty mature and 20 immature male Lewis rats.
INTERVENTION(S): Ten mature and 10 immature male Lewis rats underwent unilateral
vasectomy. At 5 months, testicular biopsy and laser-assisted vasovasostomies were
performed followed 2 months later by evaluation of vas patency and repeat
testicular biopsy. Control animals consisted of 10 rats in each group, 5 that
underwent sham operations and 5 that had halothane anesthesia alone. RESULT(S):
In the immature and mature groups unilateral vasectomy resulted in marked
contralateral testicular damage in 30% (3 of 10) and 50% (5 of 10), respectively.
Vas patency determined 2 months after vasovasostomy was 80% (8 of 10) in the
mature group and 89% (8 of 9) in the immature group. No animal that had
contralateral testicular changes after vasectomy and a patent vas after
vasovasostomy showed improvement in testicular histology. CONCLUSION(S): It
appears that contralateral testicular damage associated with unilateral vasectomy
is not improved 2 months after successful vasovasostomy in mature or immature
Lewis rats.
PMID- 10685522
TI - A novel, rapid, and accurate method for detecting microdeletion involving the DAZ
gene in infertile men.
AB - OBJECTIVE: To report on a novel, accurate method for detecting microdeletion
involving the DAZ gene in infertile men. DESIGN: Retrospective clinical study.
SETTING: University Infertility Center of Cochin Hospital, Paris, France.
PATIENT(S): Infertile patients (n = 25) consulting our infertility department
during 1998. The patient cohort included subjects with nonobstructive azoospermia
and oligoasthenospermia. INTERVENTION(S): Blood samples were collected from each
subject. MAIN OUTCOME MEASURE(S): DNA analysis using polymerase chain reaction
(PCR)-denaturing gradient gel electrophoresis (DGGE). RESULT(S): We used a new
molecular genetic strategy to rapidly identify deletions of the Y chromosome that
include the DAZ locus. The experiment consists of amplifying simultaneously exon
4 of the DAZ and DAZLA genes with the use of specific primers that are
complementary to intronic sequences of these genes. DGGE was used to separate the
two PCR products, with good resolution. In infertile men with a microdeletion of
the DAZ gene, this method allows amplification of an internal control when a
deletion of that portion of the Yq chromosome is observed on a single
amplification. CONCLUSION(S): This PCR-DGGE method for detection of DAZ gene
deletion is simple and fast and does not require the use of radioactive elements.
Compared with the classic PCR approach, this new method allows the amplification
of the DAZLA copy to be used as an effective internal control in infertile men
with microdeletion of the DAZ locus. This procedure could be particularly useful
in screening for the DAZ locus in the diagnostic workup of nonobstructive
azoospermia and severe oligoasthenoteratozoospermia.
PMID- 10685523
TI - Herpes simplex virus infection of the uterine cervix--relationship with a
cervical factor?
AB - OBJECTIVE: To determine the prevalence of genital herpes simplex virus (HSV) in
women of reproductive age and to evaluate a potential relation of asymptomatic
HSV shedding with a cervical factor. DESIGN: Prospective study. SETTING:
Outpatient infertility clinic of a university hospital. PATIENT(S): Randomly
chosen asymptomatic women (n = 1,262) with a median age of 30 years.
INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Prevalence of cervical HSV,
cervical index parameters, and other variables of CM quality, including CM
penetrability in vivo and in vitro. RESULT(S): The prevalence of HSV infection of
the uterine cervix was 5.2% (identified with cell culture). There was a tendency
toward increased viscosity of the CM in HSV-positive women, but no significant
relation with the other variables of CM quality (amount, spinnbarkeit, ferning,
cervical appearance, and cellularity of the CM), or with the summarized Insler
score or the cervical index according to World Health Organization guidelines.
Postcoital testing and the in vitro penetration test, using either partners' or
donors' semen, showed that the penetrability of the CM did not differ
significantly between women with and without cervical HSV shedding. Asymptomatic
cervical HSV infection was not significantly associated with bacterial
colonization of the lower genital tract, with leukocyte counts in cervical
secretions, with the pH of the CM or the vaginal fluid, or with antisperm
antibodies in the CM. CONCLUSION(S): The results suggest that in asymptomatic
women under controlled endocrine conditions, cervical HSV infection is not a
significant cause of impaired quality and penetrability of the CM.
PMID- 10685524
TI - Secondary amenorrhea and infertility caused by an inhibin-B-producing ovarian
fibrothecoma.
AB - OBJECTIVE: To report a case of secondary amenorrhea and infertility caused by an
inhibin-B-producing ovarian fibrothecoma. DESIGN: Case report. SETTING: Academic
medical center. PATIENT: A 37-year-old woman with a 2-year history of secondary
amenorrhea and infertility. INTERVENTION(S): Operative removal of a 5-cm ovarian
fibrothecoma. MAIN OUTCOME MEASURE(S): Luteinizing hormone, FSH, E2, inhibin-B,
TSH, and prolactin measured preoperatively and postoperatively. Immunostaining of
tumor cells for inhibin and LH. RESULT(S): Preoperative hormone levels were as
follows: FSH, 1.7 mIU/mL; LH, 23.4 mIU/mL; E2, 31 pg/mL; and inhibin B, 1,154
pg/mL. Three weeks postoperatively, the FSH was 1.5 mIU/mL, LH decreased to 7.1
mIU/mL, E2 increased to 276 pg/mL, and inhibin-B decreased to 17 pg/mL. The
fibrothecoma did not stain for LH but was strongly positive for inhibin. Regular
menstrual cycles resumed 28 days postoperatively. CONCLUSION(S): Inhibin-B
produced by an ovarian tumor profoundly suppressed FSH levels and resulted in
secondary amenorrhea and infertility. Use of sensitive and specific immunoassays
for inhibin-A and -B may aid in the differential diagnosis of hormonally active
ovarian tumors.
PMID- 10685525
TI - Influence of insulin resistance on total renin level in normotensive women with
polycystic ovary syndrome.
AB - OBJECTIVE: To evaluate the influence of insulin resistance on the plasma total
renin level in normotensive women with polycystic ovary syndrome (PCOS). DESIGN:
Prospective, controlled study. SETTING: University hospital. PATIENT(S): Twenty
five normotensive women with PCOS were compared with 11 normotensive control
women with regular cycles and no features of PCOS. INTERVENTION(S): Clinical,
ultrasonographic, and hormonal findings were used to define PCOS. Insulin
resistance was estimated by continuous infusion of glucose with model assessment
in the early follicular phase. MAIN OUTCOME MEASURE(S): Plasma levels of total
renin and angiotensin II and serum levels of gonadotropins, DHEAS, total T, free
T, 17 alpha-hydroxyprogesterone, and PRL were determined. RESULT(S): Plasma
concentrations of angiotensin II were similar in the PCOS group and the control
group. The concentration of total renin in plasma was higher in women with PCOS
than in healthy women independent of insulin resistance. The sensitivity and
specificity of the plasma total renin level to diagnose women with PCOS were
calculated as 80% and 71.4%, respectively. CONCLUSION(S): The plasma total renin
level is higher in normotensive women with PCOS than in healthy women independent
of insulin resistance.
PMID- 10685526
TI - Laparoscopic treatment of polycystic ovaries with insulated needle cautery: a
reappraisal.
AB - OBJECTIVE: To evaluate the reproductive outcome and adhesion formation after a
standardized laparoscopic treatment of polycystic ovary syndrome (PCOS) in
clomiphene-resistant infertile women. DESIGN: Retrospective study. SETTING:
University teaching hospital. PATIENT(S): One hundred twelve clomiphene-resistant
anovulatory women with PCOS. INTERVENTION(S): Laparoscopic ovarian drilling using
an insulated needle cautery. MAIN OUTCOME MEASURE(S): Ovulatory rate, pregnancy
rate, and adhesion formation. RESULT(S): After surgery, ovulation occurred
spontaneously in 73.2% of patients. The cumulative probability of conception at
12, 18, and 24 months after surgery was 54%, 68%, and 72%, respectively. With use
of Cox's proportional hazards model, the effects of age, body mass index, and
duration of infertility were evaluated. These factors were not associated with
the pregnancy rate. Of 15 women who underwent a second-look laparoscopy, 11 women
were found to be free of adhesions. Four women had periadnexal adhesions that
were filmy, minimal, and found on the ovarian surface only. CONCLUSION(S):
Laparoscopic ovarian drilling is an effective alternative treatment in clomiphene
resistant anovulatory women with PCOS. The use of an insulated needle cautery is
associated with a minimal amount of adhesion formation.
PMID- 10685527
TI - Human chorionic gonadotropin as a predictor of outcome in assisted reproductive
technology pregnancies.
AB - OBJECTIVE: To determine whether serum hCG and progesterone levels obtained 16
days after ovulation are reliable predictors of pregnancy outcome. DESIGN: A
retrospective study. SETTING: The data were obtained from two integrated Adelaide
based clinics: the Queen Elizabeth Hospital and Wakefield Clinic. PATIENT(S):
Women who have achieved a pregnancy through ART treatment. MAIN OUTCOME
MEASURE(S): Analysis of data using logistic regression (STATA v.5.0) to predict a
binary outcome: ongoing pregnancy or miscarriage. Ongoing pregnancy was defined
as progression to >20 weeks' gestation. Miscarriage included spontaneous
abortion, biochemical and ectopic pregnancies, and blighted ovum. RESULT(S):
Human chorionic gonadotropin was found to be the main determinant of ongoing
pregnancy. Age and progesterone had minor effects, whereas stimulation, luteal
support, and treatment types were nonpredictive. Low hCG levels between 25 and 50
IU/L are associated with a low probability of ongoing pregnancy (<35%), whereas
levels of >500 IU/L predict a >95% chance of ongoing pregnancy. CONCLUSION(S): A
single serum hCG level 16 days after ovulation provides a useful predictor of
pregnancy outcome.
PMID- 10685528
TI - Human chorionic gonadotropin administration does not increase plasma androgen
levels in patients undergoing controlled ovarian hyperstimulation.
AB - OBJECTIVE: To investigate the effects of hCG administered to patients undergoing
controlled ovarian hyperstimulation on levels of ovarian hormones, including
androgens. DESIGN: Prospective analysis. SETTING: Assisted Reproduction Unit,
Hopital Antoine Beclere, Clamart, France. PATIENT(S): Six infertile, normally
ovulating volunteers. INTERVENTION(S): The women underwent controlled ovarian
hyperstimulation with a GnRH agonist and hMG for IVF-ET. After the i.m.
administration of hCG (10,000 IU), blood samples were drawn every 6 hours for 4
days. MAIN OUTCOME MEASURE(S): Plasma androstenedione, testosterone,
progesterone, and E2 profiles. RESULT(S): Treatment with hMG increased plasma
androstenedione and testosterone levels 1.4-fold and 2.6-fold, respectively. The
administration of hCG did not increase plasma androstenedione and testosterone
levels any further; mean daily levels remained at 2.3 ng/mL and 0.64 ng/mL,
respectively. Circadian changes in androstenedione levels were evident after hCG
administration. Plasma progesterone levels neared 10 ng/mL 19 hours after hCG
administration, plateaued for 24 hours, and increased again thereafter. Plasma E2
levels declined during the first 2 days after hCG administration and then
increased, concomitant with the second phase of progesterone elevation.
CONCLUSION(S): In patients undergoing controlled ovarian hyperstimulation,
androgen levels increased in response to hMG treatment, but no further elevation
occurred after hCG administration. The rate of elevation of progesterone levels
and the absolute levels achieved were 3-fold and 10-fold higher, respectively,
than those observed during spontaneous menstrual cycles.
PMID- 10685529
TI - Mutation analysis of the follicle-stimulating hormone receptor gene in girls with
gonadotropin-independent precocious puberty resulting from autonomous cystic
ovaries.
AB - OBJECTIVE: To search for germline activating mutations of the FSH receptor in
girls with gonadotropin-independent precocious puberty. DESIGN: Molecular studies
in human tissue. SETTING: Four girls with polycystic ovaries and gonadotropin
independent isosexual precocious puberty without clinical and molecular features
of McCune-Albright syndrome. INTERVENTION(S): Peripheral blood was used for DNA
extraction. The alpha-subunit of the Gs gene and the entire exon 10 of FSH
receptor gene were amplified by polymerase chain reaction (PCR). Gs-alpha
mutations characteristic of McCune-Albright syndrome were excluded by
denaturating gradient gel electrophoresis (DGGE) and allele-specific PCR. Exon 10
of the FSH receptor gene was analyzed by DGGE and direct sequencing. MAIN OUTCOME
MEASURE(S): Results of DGGE and direct sequencing. RESULT(S): No germline
activating mutations were detected in exon 10 of our patients. Instead, two
previously described polymorphisms were found, leading to the substitution of
alanine for threonine at position 307 and of serine for asparagine at position
680 of the FSH receptor molecule. CONCLUSION(S): Germline activating mutations
were not found in exon 10 of the FSHR gene in any of our patients. Further
studies, preferably in ovarian tissue, will be required to exclude the presence
of somatic activating mutations of the FSH receptor in these patients.
PMID- 10685530
TI - Successful induction of ovulation using highly purified follicle-stimulating
hormone in a woman with Kallmann's syndrome.
AB - OBJECTIVE: To describe a woman with Kallmann's syndrome who was treated
successfully with highly purified FSH to achieve ovulation induction and
pregnancy. DESIGN: Case report. SETTING: University hospital. PATIENT(S): A 32
year-old woman with Kallmann's syndrome who had been treated with oral
contraceptives to prime secondary sex characteristics and genital organs since
the age of 16 years. INTERVENTION(S): Highly purified FSH was administered
intramuscularly for a total dose of 3,825 IU. MAIN OUTCOME MEASURE(S): Follicle
number and diameter. RESULT(S): Three follicles with a diameter of > 1.7 cm and
an endometrial thickness of 8 mm were observed. A clinical pregnancy, which
subsequently was spontaneously aborted, was obtained. CONCLUSION(S): In primed
patients with Kallmann's syndrome, highly purified FSH may be a useful
alternative to pulsatile GnRH or menopausal gonadotropins to achieve ovulation
induction and pregnancy.
PMID- 10685531
TI - Effects of clomiphene citrate on the endometrium of regularly cycling women.
AB - OBJECTIVE: To study the effects of clomiphene citrate (CC) on the endometrium of
regularly cycling women. DESIGN: Prospective, controlled study. SETTING:
Department of Obstetrics and Gynaecology, Faculty of Medicine, Chulalongkorn
University, Bangkok, Thailand. PATIENT(S): Thirty healthy, regularly cycling,
female volunteers. INTERVENTION(S): All volunteers were studied for two
consecutive cycles, one control cycle and one CC-treated cycle. Clomiphene
citrate (100 mg/d) was given on days 3-7 of the CC-treated cycles.
Ultrasonography was performed daily to assess ovulation. Ultrasonography and
endometrial biopsy were performed, and blood samples were obtained for
determination of E2 and progesterone levels 7 days after ovulation in both the
control and CC-treated cycles. MAIN OUTCOME MEASURE(S): Histologic dating,
morphometric analysis, and ultrasonographic appearance and thickness of the
endometrium. RESULT(S): Histologic dating and ultrasonographic appearance and
thickness of the endometrium were similar in the control and CC-treated cycles,
but morphometric parameters were different. The number of glands per square
millimeter and the mean diameter of the glands were lower in the CC-treated
cycles than in the control cycles, but the number of vacuolated cells per 1,000
glandular cells was higher. CONCLUSION(S): Clomiphene citrate has effects on the
endometrium of regularly cycling women, as demonstrated by a reduction in
glandular density and an increase in the number of vacuolated cells.
PMID- 10685532
TI - Are randomized trials of hormone replacement therapy in symptomatic women with
breast cancer feasible?
AB - OBJECTIVE: To evaluate the feasibility of conducting a large randomized trial of
HRT in symptomatic women with early-stage breast cancer. DESIGN: Open randomized
study. SETTING: Outpatient clinics at The Royal Marsden and St. George's
Hospitals, London. PATIENT(S): One hundred postmenopausal women with early-stage
breast cancer, experiencing vasomotor symptoms and/or vaginal dryness.
INTERVENTION(S): Randomization (1:1) to HRT or no HRT for 6 months. MAIN OUTCOME
MEASURE(S): Acceptance, continuance rates, and the reasons eligible women
declined study entry. RESULT(S): Acceptance (38.8%) and continuance rates (>80%)
were encouraging. The efficacy of HRT did not appear to be antagonized with
concomitant tamoxifen. Seventy-five percent of women continued HRT after the
study ended. Three women developed metastatic disease. Two used HRT.
CONCLUSION(S): Despite informed consent, a national UK randomized trial of HRT
should be feasible and has now been planned. Successful implementation
necessitates the provision of information about HRT and the estrogen deficiency
side effects of breast cancer therapy to health professionals and women with
breast cancer.
PMID- 10685533
TI - Embryonic karyotype of abortuses in relation to the number of previous
miscarriages.
AB - OBJECTIVE: To examine the frequency of chromosomal abnormalities in products of
conception from patients with recurrent miscarriages in relation to the number of
previous miscarriages. DESIGN: Retrospective analysis. SETTING: Nagoya City
University Medical Hospital. PATIENT(S): A total of 1,309 women with a history of
2-20 consecutive first-trimester abortions. INTERVENTION(S): Chromosomal analysis
performed on products of conception with use of a standard G-banding technique.
MAIN OUTCOME MEASURE(S): The frequencies of abnormal and normal embryonic
karyotypes for each number of previous abortions were studied. The subsequent
pregnancy outcome of patients whose previous miscarriages were karyotyped were
studied along with the predictive value of karyotyping of previous miscarriages
for subsequent miscarriages. RESULT(S): The miscarriage rate increased with the
number of previous spontaneous abortions. The frequency of abnormal embryonic
karyotypes significantly decreased and that of normal embryonic karyotypes
significantly increased with the number of previous abortions. Among 71 patients
whose embryonic karyotypes were normal, 44 aborted subsequently, and 23 of 60
patients whose embryonic karyotypes were abnormal aborted subsequently. Patients
with a previous normal embryonic karyotype aborted more frequently than those
with an abnormal karyotype. CONCLUSION(S): The frequency of normal embryonic
karyotypes significantly increases with the number of previous abortions, and a
normal karyotype in a previous pregnancy is a predictor of subsequent
miscarriage.
PMID- 10685534
TI - Alterations in humoral immune responses associated with recurrent pregnancy loss.
AB - OBJECTIVE: To investigate the reactivity of maternal antibodies with endometrium
derived antigens and to correlate their association with recurrent pregnancy loss
(RPL). DESIGN: Prevalence study. SETTING: Academic research center. PATIENT(S):
Nulliparous women (n = 10), women with RPL (n = 15), pregnant women (n = 8), and
multiparous women with a normal obstetric history (n = 20). INTERVENTION(S):
None. MAIN OUTCOME MEASURE(S): Reactive antibodies were analyzed by Western
immunoblot techniques and quantitated by densitometry. RESULT(S): Antibodies from
women with RPL and multiparous women recognized antigens ranging from 10-120 kd
on normal endometrium and endometrial tumors. Antibodies from most women with RPL
(10/15) and from multiparous women (15/20) recognized 65-kd and 80-kd proteins in
normal endometrium. Antibodies from women with RPL recognized 21-kd and 28-kd
antigens (12/15 and 13/15, respectively) in endometrial tumors at a significantly
greater rate (than did antibodies from multiparous women (5/20 and 8/20,
respectively). Women with RPL had significantly lower levels of asymmetric IgG
compared with controls. CONCLUSION(S): Recurrent pregnancy loss may be linked
with the failure to elicit asymmetric IgG and a unique immunologic recognition of
endometrial antigens.
PMID- 10685535
TI - Prospective, randomized, controlled study of in vitro fertilization-embryo
transfer with a single dose of a luteinizing hormone-releasing hormone (LH-RH)
antagonist (cetrorelix) or a depot formula of an LH-RH agonist (triptorelin).
AB - OBJECTIVE: To confirm the value of a single dose of 3 mg of cetrorelix in
preventing the occurrence of premature LH surges. DESIGN: Multicenter randomized,
prospective study. SETTING: Reproductive medicine units. PATIENT(S): Infertile
patients undergoing ovarian stimulation for IVF-ET. INTERVENTION(S): A single
dose of 3 mg of cetrorelix (Cetrotide; ASTA Medica, Frankfurt, Germany) (115
patients) was administered in the late follicular phase. A depot preparation of
triptorelin (Decapeptyl; Ipsen-Biotech, Paris, France) was chosen as a control
agent (39 patients). Ovarian stimulation was conducted with hMG (Menogon;
Ferring, Kiel, Germany). MAIN OUTCOME MEASURE(S): Premature LH surges (LH level
>10 IU/L), progesterone level greater than 1 ng/L, and IVF results. RESULT(S): No
LH surge occurred after cetrorelix administration. The patients in the cetrorelix
group had a lower number of oocytes and embryos. The percentage of mature oocytes
and fertilization rates were similar in both groups, and the pregnancy rates were
not statistically different. The length of stimulation, number of hMG ampules
administered, and occurrence of the ovarian hyperstimulation syndrome were lower
in the cetrorelix group. Tolerance of cetrorelix was excellent. CONCLUSION(S): A
cetrorelix single-dose protocol prevented LH surges in all patients studied. It
compares favorably to the "long protocol" and could be a protocol of choice in
IVF-ET.
PMID- 10685536
TI - Preferred treatment of infertile women older than 37 years of age who demonstrate
premature luteinization in the first evaluation cycle.
AB - OBJECTIVE: To evaluate the efficacy of various treatments in abolishing premature
luteinization in infertile women over 37 years old who are undergoing ovulation
induction. DESIGN: Prospective, nonrandomized study. SETTING: Tertiary care
medical clinic. PATIENT(S): Seventeen infertile women >37 years old in whom
premature luteinization was detected during their evaluation (pretreatment)
cycle. INTERVENTION(S): The patients underwent three consecutive treatment cycles
with clomiphene citrate (group A), hMG (group B), and a GnRH agonist plus hMG
(group C). MAIN OUTCOME MEASURE(S): Premature luteinization, defined as a
progesterone/E2 ratio of >1 on the day of hCG administration. RESULT(S): Fifteen
(88%) of the 17 patients in group A and 13 (76%) of the 17 patients in group B
demonstrated premature luteinization. In contrast, only 1 (6%) of the 17 patients
in group C had a progesterone/E2 ratio of >1 on the day of hCG administration.
The mean (+/-SD) E2 level on the day of hCG administration was significantly
higher in group C (1.236 +/- 772.7 pg/mL) than in group A (214.02 +/- 104.46
pg/mL) or group B (412.5 +/- 337 pg/mL). CONCLUSION(S): Pituitary desensitization
with a GnRH agonist in conjunction with hMG may be of benefit for older infertile
women who demonstrate early luteinization in their first evaluation cycle.
PMID- 10685538
TI - Antiphospholipid antibodies and in vitro fertilization success: a meta-analysis.
AB - OBJECTIVE: To evaluate whether the presence of antiphospholipid antibodies among
women undergoing IVF affects the likelihood of IVF success. DESIGN: A meta
analysis of seven eligible studies on antiphospholipid antibodies and IVF
outcome. MAIN OUTCOME MEASURE(S): Odds ratios (ORs) and 95% confidence intervals
(CIs) of an association between the presence of antiphospholipid antibodies and
both clinical pregnancy and live birth from IVF. RESULT(S): There was no
significant association between antiphospholipid abnormalities and either
clinical pregnancy (OR 0.99; 95% CI 0.64-1.53) or live birth (OR 1.07; 95% CI
0.66-1.75) in IVF patients. CONCLUSION(S): The measurement of antiphospholipid
antibodies is not warranted in patients undergoing IVF.
PMID- 10685537
TI - The significance of delayed suppression using buserelin acetate and recombinant
follicle-stimulating hormone in a long protocol in vitro fertilization program.
AB - OBJECTIVE: To determine whether the time taken to achieve ovarian suppression has
an impact on ovarian responsiveness and the outcome of IVF-ET. DESIGN:
Retrospective analysis. SETTING: An assisted reproduction unit at a university
center. PATIENT(S): Patients undergoing a long protocol of IVF-ET that included
buserelin acetate therapy initiated on day 2 of the cycle and recombinant FSH.
INTERVENTION(S): Patients were divided into two groups according to the duration
of buserelin acetate therapy required to achieve pituitary and ovarian
suppression (group 1 = 2 weeks, n = 172; group 2 = > or =3 weeks, n = 337). MAIN
OUTCOME MEASURE(S): Number of recombinant FSH ampules administered, duration of
ovarian stimulation (days), ovarian response, and IVF outcome. RESULT(S): The
patients in group 2 had lower mean E2 levels after 5 days and 9 days of
stimulation than the patients in group 1. The number of recombinant FSH ampules
administered and the number of days of stimulation required were higher in group
2 than in group 1. These differences were prominent in the subgroups of older
patients (> or =36 years) and patients who had no evidence of polycystic ovaries
on ultrasound examination. The number of oocytes retrieved and fertilized, the
cancelation rate, and the pregnancy rate were similar in the two groups.
CONCLUSION(S): Prolonged administration of a GnRH agonist to achieve suppression
leads to a reduced ovarian response, particularly in women > or =36 years of age,
but does not affect the success rate of IVF-ET.
PMID- 10685539
TI - Treatment of patients with long-standing unexplained subfertility with in vitro
fertilization.
AB - OBJECTIVE: To evaluate whether IVF is an effective treatment for long-standing
unexplained subfertility. DESIGN: Retrospective cohort study. SETTING: Tertiary
care infertility center in a university hospital. PATIENT(S): Two hundred two
couples with unexplained subfertility of 2 years' duration or more who attended
the center for their first IVF attempt. INTERVENTION(S): Couples were placed on a
waiting list for IVF. They received no treatment until IVF was started. MAIN
OUTCOME MEASURE(S): Pregnancy rate (PR) while on the waiting list and PR after
IVF treatment. RESULT(S): Complete data sets were available for 131 couples.
Seventeen of 131 women became pregnant while waiting for IVF treatment (PR 0.9%
per exposure cycle), whereas 45 of 119 receiving IVF treatment became pregnant
(PR 17% per IVF attempt). CONCLUSION(S): IVF treatment has substantial added
value over waiting and is an efficient treatment for long-standing unexplained
subfertility.
PMID- 10685540
TI - Follicle-stimulating hormone or human menopausal gonadotropin for ovarian
stimulation in in vitro fertilization cycles: a meta-analysis.
AB - OBJECTIVE: To reanalyze the results of using FSH alone and hMG during IVF
treatment, taking into account the different protocols of administration of
superactive GnRH agonist analogs. DESIGN: Meta-analysis. SETTING: The London
Women's Clinic. PATIENT(S): Women undergoing IVF treatment. INTERVENTION(S): A
meta-analysis of published randomized controlled trials from 1985 to 1999 of the
use of FSH versus hMG for ovarian stimulation during IVF treatment. The common
Peto odds ratio was calculated with use of a fixed effect model. The overall log
odds ratio was estimated after demonstrating the consistency or homogeneity of
the study results. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate per cycle of
IVF. RESULT(S): The results suggested that in the "long and short GnRH agonists
protocol" of IVF, FSH, and hMG were equally effective in achieving ovarian
stimulation, and there were no differences in the clinical pregnancy rates per
cycle of IVF. However, in protocols where no pituitary desensitization was used,
FSH alone was more efficacious. CONCLUSION(S): The optimum choice of gonadotropin
preparation for ovarian stimulation during IVF treatment is influenced by the
regimen of pituitary desensitization used. The optimum gonadotropin to be used
when GnRH antagonists are used has yet to be determined.
PMID- 10685541
TI - Moderate and severe endometriosis is associated with alterations in the cell
cycle of granulosa cells in patients undergoing in vitro fertilization and embryo
transfer.
AB - OBJECTIVE: To determine whether folliculogenesis is impaired in patients with
endometriosis. DESIGN: Prospective study. SETTING: Yamagata University School of
Medicine, Yamagata, Japan. PATIENT(S): Thirty women participating in an IVF
program. INTERVENTION(S): The patients were divided into four groups according to
the cause of their infertility: tubal factor (T), n = 7; male factor (M), n = 7;
idiopathic (I), n = 7; and endometriosis (E), n = 9. Granulosa cells were
obtained from the follicular fluid of each patient and analyzed by flow
cytometry. MAIN OUTCOME MEASURE(S): The percentage of granulosa cells in each
cell-cycle stage. RESULT(S): The mean (+/- SD) rate of apoptosis in the granulosa
cells obtained from the patients with endometriosis was the highest among the
four groups (T = 11.7% +/- 3.3%; M = 5.6% +/- 3.8%; I = 9.6% +/- 5.1%; and E =
18.6% +/- 9.6%). The percentage of S-phase granulosa cells was significantly
higher in the patients with endometriosis than in all the other patients combined
(E = 12.5% +/- 6%; T + M + I = 9.3% +/- 2.9%). The percentage of G2/M-phase
granulosa cells was significantly lower in the endometriosis group than in the
other three groups combined (E = 2.3% +/- 2.5%; T + M + I = 4.6% +/- 2.1%).
CONCLUSION(S): Endometriosis impairs the cell cycle in granulosa cells. This
phenomenon may have a detrimental effect on folliculogenesis.
PMID- 10685542
TI - Images in reproductive medicine. Ultrastructural defects in acquired immotile
sperm flagellae.
PMID- 10685543
TI - Evaluation of the antifertility effect of magainin-A in rabbits: in vitro and in
vivo studies.
AB - OBJECTIVE: To evaluate the safety and contraceptive potential of magainin-A in
rabbits. DESIGN: Controlled laboratory study. SETTING: Department of Immunology,
Institute for Research in Reproduction, Mumbai, Parel, India. ANIMAL(S): Forty
eight female New Zealand white rabbits. INTERVENTION(S): The effect of magainin-A
on sperm motility (in vitro and in vivo studies) and on vaginal epithelium
(histologic study) was assessed along with serum and liver biochemical profiles.
MAIN OUTCOME MEASURE(S): Suitability of magainin-A for contraceptive use.
RESULT(S): Magainin-A arrested sperm motility, and 1 mg of magainin-A
administered intravaginally blocked conception. No histopathologic abnormalities
in the vaginal tissue or any changes in serum biochemical profiles were observed.
CONCLUSION(S): Magainin-A may be used as an effective and safe intravaginal
contraceptive compound that also has antibacterial properties.
PMID- 10685544
TI - Phase-dependent influence of nonsteroidogenic cells on steroidogenesis and
prostaglandin production by the human corpus luteum.
AB - OBJECTIVE: To test the hypothesis that paraluteal cells in the human corpus
luteum (CL) modulate steroidogenesis and prostaglandin production by the CL.
DESIGN: In vitro cell culture study using human luteal cells. SETTING AND
PATIENT(S): Women (n = 7) with normal menstrual cycles who were undergoing
operations for benign, nonovarian conditions during the midluteal phase (5-9 days
after ovulation) or the late luteal phase (10-14 days after ovulation) at a
university hospital. INTERVENTION(S): Steroidogenic and nonsteroidogenic human CL
cells were isolated by mechanical and enzymatic digestion and density
sedimentation. The cells were cultured (75,000 cells per well) for 24 hours
either as a crude sample of all CL cells or as an enriched fraction of
steroidogenic CL cells. MAIN OUTCOME MEASURE(S): Levels of progesterone, E2,
prostaglandins F2alpha, E2, and I2 in conditioned medium. RESULT(S): Higher
concentrations of progesterone, E2, and prostaglandins F2alpha, E2, and I2 were
released into the media of the crude sample of all CL cells than into the
enriched fraction of steroidogenic CL cells from the midluteal phase. No such
difference was noted in CL cells from the late luteal phase. CONCLUSION(S): The
paraluteal cells in the human CL stimulated progesterone and E2 synthesis. This
may be mediated by an increase in prostaglandin production in the midluteal
phase.
PMID- 10685545
TI - Nucleoli in a pronuclei-stage mouse embryo are represented by major satellite DNA
of interconnecting chromosomes.
AB - OBJECTIVE: To investigate the arrangement of chromosomes within pronuclei-stage
mouse zygotes. DESIGN: In vitro study. SETTING: Academic medical center.
PATIENT(S): None. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Location of
major alpha-satellite DNA, centromeres, and telomeres, and relative location of
chromosomes. RESULT(S): Chromosomes appeared to be oriented inward by centromeres
and to be interconnected by major alpha-satellite DNA, which appeared to be the
sole DNA component of the nucleoli. This chromosomal arrangement persisted
throughout interphase. Chromosomal painting failed to identify chromosomal
ordering within pronuclei. CONCLUSION(S): Pronuclear nucleoli are represented by
alpha-satellite sequences of interconnecting chromosomes that hold all
chromosomes together during interphase. Chromosomes within the pronucleus are
randomly positioned relative to each other.
PMID- 10685546
TI - Effects of recombinant human FSH (rhFSH), urinary purified FSH (uFSH), and hMG on
small preantral follicles and tertiary follicles from normal adult and androgen
sterilized female mice.
AB - OBJECTIVE: To examine the stage-specific follicular response to recombinant human
FSH (rhFSH), urinary FSH (uFSH), and hMG preparations. SETTING: In vitro follicle
culture. INTERVENTION(S): Small preantral and tertiary follicles isolated from
adult normal BDF-1 mice and androgen-sterilized mice were cultured with rhFSH,
uFSH, and hMG for 4 days. MAIN OUTCOME MEASURE(S): Follicular diameter.
Immunoreactive inhibin, E2, and progesterone concentrations in cultured medium.
RESULT(S): The minimal effective dose of rhFSH, uFSH, and hMG for the follicular
growth of small preantral follicles from normal mice was 10 mIU/mL, 1 mIU/mL, and
0.1 mIU/mL, respectively. For tertiary follicles from normal mice, the minimal
effective dose of rhFSH, uFSH, and hMG was 10 mIU/mL, 10 mIU/mL, and 1 mIU/mL,
respectively. The minimal effective dose of hMG for the follicular growth of
small preantral follicles from androgen-sterilized mice was 0.01 mIU/mL, and that
of rhFSH and uFSH on tertiary follicles from androgen-sterilized mice was 1
mIU/mL and 10 mIU/mL, respectively. No significant increase was found in the
follicular diameter of the tertiary follicles from androgen-sterilized mice as a
result of stimulation by hMG, but an hMG dose of >10 mIU/mL produced a
significant increase in progesterone secretion. CONCLUSION(S): Human menopausal
gonadotropin preparation acts detrimentally on follicles from androgen-sterilized
mice by increasing the sensitivity of small preantral follicles to FSH and by
inducing the luteinization of tertiary follicles.
PMID- 10685547
TI - Temporal analysis of connexin43 protein and gene expression throughout the
menstrual cycle in human endometrium.
AB - OBJECTIVE: To analyze the pattern of connexin43 gene and protein expression in
human endometrium throughout the menstrual cycle. DESIGN: Controlled clinical
study. SETTING: An academic research center. PATIENT(S): Women with 28-day
menstrual cycles who had mechanical infertility and failed to conceive after IVF
treatment. INTERVENTION(S): Endometrial and blood samples were collected on days
8, 12, 14, 21, and 25 of spontaneous menstrual cycles. MAIN OUTCOME MEASURE(S):
Endometrial expression of connexin43 protein and messenger RNA, endometrial
thickness, and serum concentrations of gonadotropins and steroids. RESULT(S): The
expression of connexin43 gene and protein decreased on day 12 and day 14 of the
menstrual cycle and then increased on day 21 and day 25, respectively. A serum LH
surge accompanied by a peak in the FSH concentration was observed on days 12-14.
The progesterone concentration increased on days 21-25, but there was no
significant change in the E2 concentration. The thickness of the endometrium
increased between days 8 and 12 and did not change further between days 21 and
25. CONCLUSION(S): The expression of connexin43 gene and protein in human
endometrium changes during the menstrual cycle in a pattern that is associated
with the secretion of LH, FSH, and progesterone. This pattern may serve as a
marker for implantation competence.
PMID- 10685548
TI - Comparative effects of quinacrine and erythromycin in adult female rats: a
nonsurgical sterilization study.
AB - OBJECTIVE: To compare the efficacies of erythromycin and quinacrine for
nonsurgical sterilization in rats. Quinacrine used for nonsurgical sterilization
in women is mutagenic, and most clinical regimens have had a higher failure rate
than surgical sterilization. DESIGN: This acute mammal study included five groups
of rats assigned randomly and evaluated at two times after treatment. ANIMAL(S):
Adult female Sprague-Dawley rats. INTERVENTION(S): Five groups of female Sprague
Dawley rats (20 per group) were given 70 or 280 mg/kg of erythromycin
lactobionate, 350 mg/kg of quinacrine hydrochloride, or vehicle control
administered transcervically. Rats were mated 21 days later. Additional groups (n
= 4 per group) were treated and killed 21 days later without mating. MAIN OUTCOME
MEASURE(S): Fourteen days after mating, numbers of ovarian corpora lutea, total
uterine implants, and embryos were evaluated. For unmated animals, uterine
sections were examined for fibrosis and lumen closure. RESULT(S): Neither drug
altered numbers of corpora lutea. Erythromycin decreased pregnancy rate and
number of implantations (increased preimplantation loss) in a dose-related
fashion. Quinacrine increased resorptions. Uterine pathology was more extensive
and frequent in erythromycin-treated animals, with extent and severity increasing
from 21 to 35+ days. CONCLUSION(S): Erythromycin was more effective than
quinacrine in preventing pregnancy.
PMID- 10685549
TI - Human sperm microinjection into hamster oocytes: a new tool for training and
evaluation of the technical proficiency of intracytoplasmic sperm injection.
AB - OBJECTIVE: To design a system for teaching intracytoplasmic sperm injection
(ICSI) and to provide a standardized method to assess technical competency.
SETTING: University andrology laboratory. DESIGN: Prospective study of method for
training ICSI and prediction of ICSI outcome. PATIENT(S): Male infertility
candidates for ICSI and fertile donors. INTERVENTION(S): Sperm from 14 fertile
donors and 21 oligospermic patients were microinjected into hamster ova. Sperm
head decondensation rates (SHD) and oocyte damage rates were measured. Hamster
ICSI (HICSI) was used to train technicians, to assess competency, for quality
control, and to predict ICSI fertilization. Sperm fertilization potential
measured by HICSI was compared with the outcome of ICSI. MAIN OUTCOME MEASURE(S):
Sperm head decondensation or fertilization. RESULT(S): Sperm head decondensation
was observed in 425 of 773 hamster oocytes with a mean (+/- SD) rate of 60.9 +/-
15.5. Consistency was shown by repetitive testing of the same donor, comparing
fresh and frozen semen, and testing of the multiple frozen aliquots of the same
ejaculate. Technicians have been trained with this protocol. Excellent initial
ICSI success rates for new technicians were demonstrated. Oligospermic semen
samples (21 men, 251 hamster ova) tested in the HICSI test exhibited SHD rates
from 12% to 100%. The poor outcome of ICSI in clinical cases was predicted by
HICSI. CONCLUSION(S): The HICSI provides a method for determining the competency
for the ICSI technician and interlaboratory comparison, for the prediction of
success of sperm for ICSI.
PMID- 10685550
TI - Transcervical placement of a Malecot catheter after hysteroscopic evaluation
provides for easier entry into the endometrial cavity for women with histories of
difficult intrauterine inseminations and/or embryo transfers: a prospective case
series.
AB - OBJECTIVE: To evaluate a new technique designed to improve access to the
endometrial cavity through tortuous and/or stenotic endocervical canals in women
with histories of difficult IUIs, ETs, or endometrial biopsies. DESIGN:
Prospective case series. SETTING: Tertiary care center. PATIENT(S): Women with
histories of difficult intrauterine procedures because of tortuous and/or
stenotic endocervical canals who continued to undergo treatment. INTERVENTION(S):
Hysteroscopic evaluation and/or correction of the endocervix, followed by
transcervical placement of a Malecot catheter (CR Bard Inc., Covington, GA) for
an average of 10 days. MAIN OUTCOME MEASURE(S): Improvement in the ease of access
to the endometrial cavity during IUIs or ETs. RESULT(S): Thirty-two of 36
patients had significantly easier procedures after the placement and removal of a
Malecot catheter. CONCLUSION(S): Hysteroscopic evaluation and placement of a
Malecot catheter is a useful technique that allows easier entry through the
cervical canal in patients in whom previous IUIs, ETs, and endometrial biopsies
have been difficult. This procedure may lead to improved pregnancy rates,
particularly with IVF-ET, as the ease of ET has been correlated with improved
implantation rates.
PMID- 10685551
TI - Diagnostic accuracy of sonohysterography, transvaginal sonography, and
hysterosalpingography in patients with uterine cavity diseases.
AB - OBJECTIVE: To evaluate the diagnostic accuracy of sonohysterography (SHG) in
uterine cavity diseases in infertile patients, comparing its results with those
of hysterosalpingography (HSG) and transvaginal sonography (TVS). Hysteroscopy
was the gold standard. DESIGN: Descriptive, prospective study. SETTING: A
tertiary university referral center. PATIENT(S): Sixty-five infertile women 19 to
43 years of age. INTERVENTION(S): Patients underwent SHG, conventional TVS, HSG,
and hysteroscopy. MAIN OUTCOME MEASURE(S): The results of each examination were
compared with those obtained by the gold standard. The following diagnoses were
considered separately: polypoid lesions, uterine malformations, intrauterine
adhesions, and endometrial hyperplasia (EH). Sensitivity, specificity, positive
and negative predictive values (PPV and NPV, respectively), and 95% confidence
intervals were calculated. RESULT(S): Sonohysterography had the same diagnostic
accuracy as the gold standard for polypoid lesions and EH, with no equivocal
diagnosis. Hysterosalpingography showed a sensitivity of 50% and a PPV of 28.6%
for polypoid lesions and a sensitivity of 0% for EH. Transvaginal sonography had
both sensitivity and PPV of 75% for polypoid lesions and EH. For uterine
malformations, SHG had a sensitivity of 77.8%, whereas TVS and HSG both had a
sensitivity of 44.4%. Sonohysterography and HSG had a sensitivity of 75% in the
detection of intrauterine adhesions and respective PPVs of 42.9% and 50%.
Transvaginal sonography showed sensitivity and PPV of 0% for this diagnosis.
CONCLUSION(S): Sonohysterography was in general the most accurate test. Its
diagnostic accuracy was markedly superior for polypoid lesions and EH, with total
agreement with the gold standard. In diagnosis of intrauterine adhesions, SHG had
limited accuracy, similar to that obtained by HSG, with a high false-positive
diagnosis rate.
PMID- 10685552
TI - Predictive value of transvaginal sonography performed before routine diagnostic
hysteroscopy for evaluation of infertility.
AB - OBJECTIVE: To compare transvaginal sonography with hysteroscopy for the
evaluation of intrauterine disorders. DESIGN: Clinical study. SETTING: Academic
research environment. PATIENT(S): Patients who were undergoing initial evaluation
for primary or secondary infertility or investigation after three failed IVF
attempts. INTERVENTION(S): Transvaginal sonography was performed, followed by
hysteroscopy, between January 1998 and April 1999. The endometrial findings at
sonography were compared with those at hysteroscopy, which served as the gold
standard. The characteristic sonographic features of intrauterine adhesions were
defined. MAIN OUTCOME MEASURE(S): Intrauterine adhesions, endometrial polyps.
RESULT(S): The sensitivity, specificity, and positive and negative predictive
values for transvaginal sonography in detecting abnormal uterine cavities were
100%, 96.3%, 91.3%, and 100%, respectively. The corresponding values for the
specific diagnoses of intrauterine adhesions and endometrial polyps were 80%,
100%, 100%, and 97%, and 71.4%, 100%, 100%, and 97.1%, respectively. On
transvaginal sonography, intrauterine adhesions appeared as hyperechoic
endometrial foci and were differentiated from endometrial polyps by their
irregular shape and more precise localization. The performance of transvaginal
sonography at midcycle (three-layer endometrium) rather than after menstrual
cessation (endometrial thickness <3 mm) enabled better imaging of small
intrauterine adhesions. CONCLUSION(S): A regular myometrial-endometrial interface
and homogeneous endometrial structure on transvaginal sonography congruent with
the phase of the menstrual cycle indicated a normal endometrium and precluded the
need for diagnostic hysteroscopy. Transvaginal sonography may be used as the
initial diagnostic procedure to select patients for hysteroscopy.
PMID- 10685553
TI - The need for more CEPHS.
PMID- 10685554
TI - The need for more CEPHS.
PMID- 10685555
TI - Predictive value of ovarian endometriosis?
PMID- 10685556
TI - The value of day 3 follicle-stimulating hormone levels.
PMID- 10685557
TI - Concluding letter from Robert F. Harrison on the predictive value of serum FSH
levels.
PMID- 10685558
TI - Declining human fertility?
PMID- 10685559
TI - Craniofacial ballpoint pen injury: endoscopic management.
AB - Penetrating facial injuries are not infrequent. There have been isolated case
reports of unusual penetrating craniofacial trauma. We describe an unusual case
of a 22-month-old child who suffered an external orbital injury from a ballpoint
pen that penetrated the orbit, lamina papyracea, posterior ethmoid sinuses, and
sphenoid sinus. Endoscopic sinus surgery was performed to extract the ballpoint
pen nib after localization with computed tomography. Careful pediatric endoscopic
sinus surgery techniques permitted safe foreign body extraction with minimal
morbidity.
PMID- 10685560
TI - Preliminary clinical results of window partial laryngectomy: a combined
endoscopic and open technique.
AB - Endoscopic laser resection for anterior commissure glottic carcinoma is
difficult, because of inadequate exposure and close proximity to the underlying
cartilage. A technique combining endoscopic carbon dioxide laser incision and an
external approach creating a window in the thyroid cartilage was initially tested
in a canine study and then performed in 5 patients. All patients were men, with
T1 or T2 glottic or supraglottic cancer involving the anterior commissure, and
had failed radiation treatment. The true or false vocal fold tumors were excised
along with the paraglottic space and adjacent cartilage, with preservation of the
remaining thyroid framework. The reconstruction was accomplished with placement
of a sternohyoid muscle flap, by use of either a bipedicled muscle flap with
overlying skin or a unipedicled muscle flap with a graft of free mucosa. The
graft was secured in place with fibrin glue and laser soldering. Follow-up ranged
from 11 months to 4 years and included biopsies. All patients had voice
recordings before and after surgery. A tracheostomy was avoided in all patients.
The hospital stays were 4 to 13 days. The voice quality was good after surgery.
One patient died of unrelated causes 18 months after his surgery without evidence
of recurrence. The other patients are still alive with no evidence of disease.
The only complication was subcutaneous neck emphysema in 1 patient that
spontaneously resolved. The results showed a satisfactory anatomic reconstruction
and acceptable functions. We believe that this new combined technique is
oncologically sound, may overcome the limited access seen with the endoscopic
technique and the excessive cartilage resection seen with external partial
laryngectomy, avoids a tracheostomy, and shortens hospital stays.
PMID- 10685561
TI - Quantitative endoscopy: initial accuracy measurements.
AB - The geometric optics of an endoscope can be used to determine the absolute size
of an object in an endoscopic field without knowing the actual distance from the
object. This study explores the accuracy of a technique that estimates absolute
object size from endoscopic images. Quantitative endoscopy involves calibrating a
rigid endoscope to produce size estimates from 2 images taken with a known
traveled distance between the images. The heights of 12 samples, ranging in size
from 0.78 to 11.80 mm, were estimated with this calibrated endoscope. Backup
distances of 5 mm and 10 mm were used for comparison. The mean percent error for
all estimated measurements when compared with the actual object sizes was 1.12%.
The mean errors for 5-mm and 10-mm backup distances were 0.76% and 1.65%,
respectively. The mean errors for objects <2 mm and > or =2 mm were 0.94% and
1.18%, respectively. Quantitative endoscopy estimates endoscopic image size to
within 5% of the actual object size. This method remains promising for
quantitatively evaluating object size from endoscopic images. It does not require
knowledge of the absolute distance of the endoscope from the object, rather, only
the distance traveled by the endoscope between images.
PMID- 10685562
TI - Involvement of carbon monoxide in the innervation of the canine cervical
esophagus and trachea.
AB - We investigated the involvement of carbon monoxide (CO) in the innervation of the
canine cervical esophagus and trachea by means of immunohistochemistry using an
antiserum against heme oxygenase-2 (HO-2). We detected HO-2-immunoreactive nerve
fibers around the blood vessels and submucosal glands of the esophagus and
trachea. We found HO-2-immunoreactive neurons in ganglia in the trachea and in
the myenteric plexus of the esophagus. These results suggest that CO is involved
as a neurotransmitter in the innervation of the canine esophagus and trachea.
PMID- 10685563
TI - Comparative histology of the maculae flavae of the vocal folds.
AB - A light and electron microscopic comparative investigation of the maculae flavae
of the vocal folds was carried out on excised human and canine adult larynges.
The structure and functions of human adult maculae flavae (HMF) were found to
differ from those of canine adult maculae flavae (CMF). The maculae flavae were
composed of fibroblasts, elastic and collagenous fibers, and ground substance in
humans and canines. The density of fibroblasts in HMF was found to exceed that in
CMF. Fibroblasts in HMF were stellate with processes or spindle-shaped, and the
nucleus-cytoplasm (N/C) ratio was small. Rough endoplasmic reticulum and Golgi
apparatus were well developed in the cytoplasm. Fibroblasts in CMF were oval, and
the N/C ratio was large. Endoplasmic organs were poorly developed in the
cytoplasm. Synthesized elastic and collagenous fibers were more numerous in HMF
than CMF, and the density of both in HMF was much greater than that in CMF.
Ground substance was more abundant in CMF than HMF. Apparently, CMF did not
produce elastic and collagenous fibers in amounts sufficient to develop vocal
ligaments. The HMF contributes to the formation of the vocal ligaments and the
layered structure of human vocal folds.
PMID- 10685564
TI - Microsurgery of sulcus vergeture with carbon dioxide laser and injectable
collagen.
AB - Between January 1989 and June 1998, we operated on 45 patients for sulcus
vergeture. The studied population encompassed 38 women (84%) and 7 men (16%). The
median age was 36 (range 12 to 71 years). The surgical technique is based on a
concept of Cornut and Bouchayer according to which the dissection of the
epithelium adherent to the deep subepithelial plane improves the vocal fold
vibration. Dissection is performed with a single-pulsed carbon dioxide laser at 2
to 3 W with a pulse duration of 0.1 second. We use the Super-pulse microwave. The
Acuspot micromanipulator provides a spot size of 250 microm at 350-mm focal
length. When the vocal fold is atrophic, surgery is completed with a bovine or
autologous collagen injection; the median injected quantity is 0.3 mL (range 0.1
to 0.4 mL). The epithelial microflap is redraped with fibrin glue. Voice therapy
is indispensable for correcting the associated hyperkinetic dysphonia. The median
postoperative follow-up period is 5 months (range 1 to 18 months). In terms of
median values, the maximum phonation time improved from 9 to 13 seconds, the
phonation quotient improved from 296.5 to 228.5 mL/s, and the spectral analysis
distribution improved by 1 class. Stroboscopic examination reveals an improvement
of the vibratory symmetry, amplitude, and wave. Subjectively, the patients
describe an improved ability for vocal effort and the regression or disappearance
of vocal fatigue. Although the timbre is improved, the voice often remains
breathy and hoarse.
PMID- 10685565
TI - Videoendoscopic laryngeal surgery.
AB - This paper introduces videoendoscope-assisted laryngeal surgery with office-based
equipment. With this technique, a patient is seated and the nose, pharynx, and
larynx are topically anesthetized. A flexible videoendoscope with a light
sensitive charge-coupled device chip built into the tip is transnasally inserted
by an assistant. Specially designed fine-tipped forceps and scalpels were
developed for removal of laryngeal lesions. Videoendoscopic laryngeal surgery was
undertaken in 114 cases of laryngeal lesions such as polyps, granuloma, and
cancer. For benign vocal fold lesions, postoperative vocal function was shown to
be improved on aerodynamic and perceptual analyses. For laryngeal tumors, biopsy
of the lesion was easily undertaken. Videoendoscopic laryngeal surgery presents
the following advantages. It is applicable to outpatients not requiring general
anesthesia, it enables functional monitoring of the patient's voice and vocal
fold during phonation, it allows for delicate manipulations with both hands, and
it gives high-resolution images in comparison to conventional fiberscopy.
PMID- 10685566
TI - Curative radiotherapy for anterior commissure laryngeal carcinoma.
AB - There is continuing controversy surrounding the most effective treatment of
glottic carcinoma involving the anterior commissure (AC). Surgery has been the
preferred method of treatment, since studies previously indicated early tumor
invasion of the thyroid cartilage at the AC, thereby assuming less curability by
radiotherapy (RT). Subsequent laryngeal anatomic studies and refinement of RT
techniques have brought into question the ineffectiveness of curative
irradiation. A retrospective review of 174 patients with early-stage glottic
carcinoma treated with standard fractionation curative RT revealed 34 patients
with T1 and T2 lesions involving the AC. Allowing for a follow-up of at least 3
years, we observed only a 12% (4 of 34 patients) local recurrence rate after RT
alone, with excellent voice quality and no major complications related to the
irradiation. The 4 local recurrences were controlled by total laryngectomy,
although 2 patients developed distant metastatic disease. Radiotherapy represents
an effective method of treating T1 squamous cell carcinoma of the glottis with AC
involvement. The small number of T2 glottic carcinomas in this study prevents a
meaningful conclusion concerning treatment of these lesions.
PMID- 10685567
TI - Cochlear implantation for auditory rehabilitation in Camurati-Engelmann disease.
AB - Camurati-Engelmann disease (progressive hereditary diaphyseal dysplasia) is a
rare sclerotic bone disease involving the diaphyses of the long bones, skull
base, and clavicles. Progressive sclerosis of cranial nerve foramina has been
implicated in cranial nerve deficits. including facial nerve palsy, vestibular
disturbances, and hearing loss. Two patients with Camurati-Engelmann disease and
concomitant sensorineural hearing loss are presented. Both patients were
evaluated for cochlear implantation. One patient was successfully implanted after
preoperative imaging revealed no involvement of the internal auditory canals. The
porous nature of the affected bone, however. necessitated the inactivation of 1
electrode to prevent facial nerve stimulation. A second patient was rejected as a
potential implant recipient due, in part, to narrow internal auditory canals and
rapidly progressive disease. The otologic manifestations of Camurati-Engelmann
disease are reviewed, and issues related to cochlear implantation in this rare
disease are discussed.
PMID- 10685568
TI - Experimental study following inactive implantation of an auditory brain stem
implant in nonhuman primates.
AB - We report changes in the cochlear nuclei (CNs) after 3 months of bilateral
auditory deafferentation and simultaneous unilateral implantation of a dummy
auditory brain stem implant (ABI) in 6 nonhuman primates (Macaca fascicularis).
These specimens were compared to CNs of 9 controls and 7 bilaterally deafferented
animals without implantation. The ABI array consists of 3 platinum electrodes
mounted on a silicone pad with the back side covered with Dacron. No migration of
the ABI was observed. All deafferented animals showed astrocytic reorganization
in the CNs. Histologic changes consisted of superficial reactions around the
implant, with formation of fibrillar bundles of fusiform cells, and the presence
of giant cells close to the Dacron. Other findings were related to surgical
trauma. The dummy ABI did not itself provoke serious adverse reactions in the
CNs. Our observations support the possibility of ABI reimplantation surgery.
PMID- 10685569
TI - Production of diagnostic rules from a neurotologic database with decision trees.
AB - A decision tree is an artificial intelligence program that is adaptive and is
closely related to a neural network, but can handle missing or nondecisive data
in decision-making. Data on patients with Meniere's disease, vestibular
schwannoma, traumatic vertigo, sudden deafness, benign paroxysmal positional
vertigo, and vestibular neuritis were retrieved from the database of the
otoneurologic expert system ONE for the development and testing of the accuracy
of decision trees in the diagnostic workup. Decision trees were constructed
separately for each disease. The accuracies of the best decision trees were 94%,
95%, 99%, 99%, 100%, and 100% for the respective diseases. The most important
questions concerned the presence of vertigo, hearing loss, and tinnitus; duration
of vertigo; frequency of vertigo attacks; severity of rotational vertigo; onset
and type of hearing loss; and occurrence of head injury in relation to the timing
of onset of vertigo. Meniere's disease was the most difficult to classify
correctly. The validity and structure of the decision trees are easily
comprehended and can be used outside the expert system.
PMID- 10685570
TI - Rheumatoid arthritis of the temporomandibular joint with herniation into the
external auditory canal.
AB - Previous authors have shown that soft tissue can present in the external auditory
canal via a patent foramen of Huschke. One case represented a patient with
psoriatic arthritis and a polyp in the external auditory canal. Typically,
neoplastic, inflammatory, or degenerative lesions of the temporomandibular joint
do not present in the external auditory canal. We present a patient with
rheumatoid arthritis of the temporomandibular joint and soft tissue herniation
into the external auditory canal. The case, and a discussion of possible causes,
are presented.
PMID- 10685571
TI - Immunohistochemical localization of collagen types I, III, and IV, laminin,
fibronectin, and keratin in the endolymphatic sac.
AB - We have employed immunohistochemistry to obtain baseline information on the
molecular constituents of the extracellular matrix (ECM) of the endolymphatic
duct (ED) and endolymphatic sac (ES) of the chinchilla. The results demonstrated
that collagen types I and III were distributed in the subepithelial layer in the
ED and ES, type IV collagen and laminin in the basement membranes, and
fibronectin in the subepithelial layer and partly in the conglomerated cells in
the ES. Collagen type III was diffusely distributed in the whole subepithelial
layer of the ES, whereas collagen type I was concentrated densely in the deep
layer of the interstitium, although gradually, the cuboidal epithelium in the ES
was transformed into a flatter type in the ED. The epithelial cells of the ED and
ES were clearly positive for keratin. This study deals, in particular, with the
normal distribution of ECM components of the ED and ES of the chinchilla.
PMID- 10685572
TI - Midline lateralization thyroplasty for adductor spasmodic dysphonia.
AB - Midline lateralization thyroplasty was successfully performed on a patient with
adductor spasmodic dysphonia. The thyroid cartilage was incised at the midline,
and a 3 x 2-mm perforation was made at the anterior commissure to widen it. The
perforation was closed with a free composite graft taken from the upper edge of
the thyroid ala, and the incised thyroid cartilage edges were kept separated 4 mm
apart with silicone wedges. A part of the sternohyoid muscle was rotated to seal
any leak from the perforation. The postoperative course was uneventful. The voice
has been restored to normal, and there is no sign of recurrence of the symptom so
far, as of 1 year 5 months postoperative. Although a longer follow-up is needed,
this case indicates that midline type II thyroplasty could be a useful treatment
for adductor spasmodic dysphonia.
PMID- 10685573
TI - Effects of botulinum toxin on pathophysiology in spasmodic dysphonia.
AB - To determine the mechanism of symptom relief with treatment by botulinum toxin
injection in persons with adductor spasmodic dysphonia (ADSD), we evaluated the
effects of unilateral thyroarytenoid muscle injections on both injected and
noninjected muscles in 10 subjects with ADSD, using electromyography on both
sides of the larynx before and after treatment. The subjects' speech symptoms
were reduced (p = .005) 2 weeks following injection, when the electromyographic
study occurred. Muscle activation levels and the numbers of spasmodic muscle
bursts decreased significantly (p < or = .03) postinjection in both the injected
and noninjected muscles. The reductions in laryngeal muscle bursts correlated
with symptom reduction (r > or = .7) in all muscles. Reductions in laryngeal
muscle bursts did not relate to either absolute or normalized levels of muscle
activity before or after botulinum toxin injection. The results suggest that
changes in the central pathophysiology are responsible for changes in speech
symptoms following treatment.
PMID- 10685574
TI - Botulinum toxin injections for essential voice tremor.
AB - Fifteen patients, 13 women and 2 men, with a mean age of 72.7 years (56 to 86
years) and a clinical diagnosis of essential voice tremor, were treated with
botulinum injections to the thyroarytenoid muscles, and in some cases, to the
cricothyroid or thyrohyoid muscles. Evaluations were based on subjective
judgments by the patients, and on perceptual and acoustic analysis of voice
recordings. Subjective evaluations indicated that the treatment had a beneficial
effect in 67% of the patients. Perceptual evaluations showed a significant
decrease in voice tremor during connected speech (p < .05). Acoustic analysis
showed a nearly significant decrease in the fundamental frequency variations (p =
.06) and a significant decrease in fundamental frequency during sustained vowel
phonation (p < .01 ). The results of perceptual evaluation coincided most closely
with the subjective judgments. It was concluded that the treatment was successful
in 50% to 65% of the patients, depending on the method of evaluation.
PMID- 10685575
TI - Mucociliary transport pathway on laryngotracheal tract and stented glottis in
guinea pigs.
AB - We investigated the laryngotracheal mucociliary transport pathway of guinea pigs
in vivo and immediately postmortem. Only intraperitoneal anesthesia was used
during the procedure to avoid the disturbance of mucociliary function. Resin
particles were used as the marking substance. A microcolpohysteroscope was placed
at different levels in the laryngotracheal region for observing the marking
particles and recording the transport pattern. The tracheal mucociliary transport
flow primarily moved along the posterior wall and both lateral walls in a zigzag
trace. Upon reaching the subglottis, the resin particles stayed underneath the
vocal cords, and a whirlpool phenomenon developed. The majority of the particles
were shifted and directed onto the posterior glottic area. With a short delay,
some resin particles crossed over the free edge of the vocal cords and turned
posteriorly along the medial upper cordal margin. No mucociliary transport could
be observed on the entire upper surface of the true vocal cords, which is covered
by squamous epithelium. Occasionally, a few resin particles in the vicinity of
the epiglottic root traveled along the aryepiglottic folds toward the posterior
commissure. All streams of mucociliary transport finally joined together in the
interarytenoid area. After leaving the glottis, the resin particles traveled to
the hypopharynx and entered the esophagus through the motion of deglutition. The
pattern of mucociliary clearance in the laryngotracheal region was not delayed by
stenting.
PMID- 10685576
TI - Myosin heavy chain expression in human laryngeal muscle fibers. A biochemical
study.
AB - Since the intrinsic laryngeal muscles in humans are involved in specialized
functions, one may suppose that this would be associated with the expression of
specific myosin heavy chain (MHC) isoforms, as has been reported for the rat,
dog, and rabbit. In order to determine which MHCs are expressed in the human
laryngeal muscles, biochemical analysis using sodium dodecyl sulfate
polyacrylamide gel electrophoresis was performed. Thyroarytenoid and posterior
cricoarytenoid muscles were obtained from a 7-month-old infant and 4 adults. In
the adult human laryngeal muscles, 3 bands were resolved identical to those
previously described in the human limb muscles (I, IIA, and IIB MHCs). In
contrast, muscles from the infant also expressed fetal MHC and a novel MHC not
observed in other human skeletal muscles. This novel band migrated at the same
level as the laryngeal MHC previously described in the rat. Since these 2
isoforms disappear in the adult, the persistence in the infant could be
correlated with the immature development of laryngeal functions and, in
particular, phonation.
PMID- 10685577
TI - Histopathologic study of alternative substances for vocal fold medialization.
AB - This research investigated the histopathologic and migratory properties of
injectable alternatives for vocal fold medialization. Thirteen dogs underwent
sectioning of the recurrent laryngeal nerve followed by vocal fold injection with
1 of 4 substances: Teflon, autologous fat, silicone suspension, or hydroxyapatite
cement. Six months later, the animals were painlessly sacrificed and
histopathologic analysis of the larynx and regional lymph nodes was performed.
Although regional lymph node migration was noted, Teflon injection resulted in
minimal vocal fold inflammatory reaction. Vocal folds injected with autologous
fat exhibited persistence of fat at the injection site without significant
inflammation or migration. Silicone suspension caused a localized giant cell
reaction without regional lymph node migration, and 1 study subject died
secondary to acute inflammation with critical respiratory compromise.
Hydroxyapatite cement was well tolerated without inflammation or migration. This
pilot study indicates that a wide range of possible substances for vocal fold
medialization exist. Many of these may produce results superior to those obtained
with Teflon and are thus far untested.
PMID- 10685578
TI - Sinusitis and carotid artery stroke.
AB - The relationship between sinusitis and ischemic stroke is unexplored. The
anatomic proximity between the paranasal sinuses and the internal carotid artery
suggests that inflammation of the sinuses could easily extend to the intracranial
vasculature. We report 4 patients with acute ischemic stroke and extensive
disease of the paranasal sinuses. All patients had large vessel stroke involving
the internal carotid artery territory. All patients had extensive disease of the
sphenoid and other sinuses. The sinus disease was demonstrated by magnetic
resonance imaging. These case report observations suggest a relationship between
inflammation of the paranasal sinuses, particularly sphenoid sinusitis, and
ischemic stroke.
PMID- 10685579
TI - Aneurysm of an aberrant right subclavian artery presenting as dysphagia lusoria.
PMID- 10685580
TI - Hyalinizing trabecular adenoma of the thyroid diagnosed by fine-needle aspiration
biopsy.
PMID- 10685581
TI - A trial to determine the risk of decompression sickness after a 40 feet of sea
water for 200 minute no-stop air dive.
AB - BACKGROUND: The USN93 probabilistic model of decompression sickness (DCS)
predicts a DCS risk of 3.9% after a 40 ft of seawater (fsw) for 200 min no-stop
air dive, although little data is available to evaluate the accuracy of this
prediction. Based on an analysis of Navy Safety Center data from diving on U.S.
Navy standard air decompression tables, the observed incidence of DCS for this
type of dive is 0.11%. Knowing the true incidence of the dive is important for
deciding whether or not to adopt proposed probability based decompression
procedures for U.S. Navy diving. HYPOTHESIS: The risk of DCS after a 40 fsw for
200 min no-stop air dive is 3.9%. METHODS: We conducted a closed sequential trial
to determine the DCS incidence on this dive. RESULTS: Of 30 military divers who
completed 91 dives, there were 2 cases of DCS (2.2%, 95% CI: 0.27 7.7%). The
study was terminated early after the second DCS case because of the presence of
neurological symptoms and signs. CONCLUSIONS: This study demonstrates that the
incidence of DCS in a laboratory setting is higher than observed in fleet diving.
Use of the 40 fsw for 200 min schedule in a decompression computer is likely to
result in DCS incidence 2.5- to 70-fold greater than that observed in U.S. Navy
diving using table-based procedures.
PMID- 10685582
TI - Escape from a disabled submarine: decompression sickness risk estimation.
AB - Individual crewmember escape from a disabled U.S. Navy nuclear submarine has
never been necessary, but remains an important contingency. Decompression
sickness (DCS) is one of the foreseeable risks and a robust mathematical model of
DCS incidence has been used to estimate the magnitude of this risk under a
variety of escape scenarios. The model was calibrated with over 3000 well
controlled human pressure exposures, less than 2% of which simulated pressure
profiles of submarine escape. For disabled submarine depths < 300 ft of sea water
(fsw) and internal submarine pressures of <11 fsw (arguably the most likely
conditions), the DCS risks are comparable to those routinely undertaken by U.S.
Navy divers--less than 5%. For progressively deeper depths and especially for
higher submarine internal pressures, the risk of DCS becomes much greater,
including unknown chances of permanent injury and death. Variations from the
baseline escape procedure are explored, including equipment differences, delays
in exiting the submarine and changes in the oxygen content of the breathing mix.
PMID- 10685583
TI - The effectiveness of ground level oxygen treatment for altitude decompression
sickness in human research subjects.
AB - BACKGROUND: Current therapy for altitude decompression sickness (DCS) includes
hyperbaric oxygen therapy and ground-level oxygen (GLO). The purpose of this
paper is to describe the Air Force Research Laboratory experience in the
extensive use of GLO for the treatment of altitude DCS in research subjects.
METHODS: Data were collected from 2001 altitude chamber subject-exposures. These
data, describing DCS symptoms, circulating intracardiac venous gas emboli, and
treatment procedures used were collected for each subject exposure and stored in
an altitude DCS database. RESULTS: In the database of 2001 subject exposures, 801
subjects (40.0%) were diagnosed with altitude DCS. Subjects reporting DCS
symptoms were immediately recompressed to ground level. Of the 749 subjects who
received 2 h GLO, 739 (98.7%) resolved completely and required no further
treatment. CONCLUSIONS: Although not an operational study, these data provide
indirect support for the current USAF guidelines for the treatment of altitude
DCS with GLO.
PMID- 10685584
TI - Complications and side effects of hyperbaric oxygen therapy.
AB - BACKGROUND: Despite ongoing controversy, hyperbaric oxygen (HBO) therapy is
frequently administered in various clinical situations. Probably because of the
unique atmospheric conditions to which the patient is exposed, there are concerns
about the safety aspects of this therapy. Possible complications during HBO
therapy include barotraumatic lesions (middle ear, nasal sinuses, inner ear,
lung, teeth), oxygen toxicity (central nervous system, lung), confinement
anxiety, and ocular effects (myopia, cataract growth). METHODS: To analyze the
medical safety of HBO therapy, this report reviewed complications and side
effects of 782 patients treated for various indications with a total of 11,376
HBO therapy sessions within a multiplace chamber. The absolute treatment pressure
was 240 or 250 kPa 114 or 15 msw). The compression was performed in a linear
manner with 14 to 15 kPa (1.4 to 1.5 msw) x min(-1). All data were gathered
prospectively within a special database. RESULTS: More than 17% of all patients
experienced ear pain or discomfort as an expression of problems in equalizing the
middle ear pressure. Most episodes were not related to a persistent eustachian
tube dysfunction since they only occurred once. Barotraumatic lesions on visual
otological examinations (ear microscopy) were verified in 3.8% of all patients.
Patients with sensory deficits involving the ear region need special attention,
because they seem to be at risk for rupture of the tympanic membrane (three cases
documented). A barotrauma of the nasal sinuses occurred rarely and no
barotraumatic lesions of the inner ear, lung, or teeth were noted. Oxygen
toxicity of the CNS manifested by generalized seizures affected four patients
without any recognizable risk factors or prodromes. None of the patients suffered
recurrences or sequelae. Regular checks of the blood glucose in diabetics failed
to reveal episodes of hypoglycemia as a cause for seizures. Lung function tests
of patients undergoing prolonged treatment (average 52.8 sessions) did not
deteriorate. CONCLUSION: Patients scheduled for HBO therapy need a careful pre
examination and monitoring. If safety guidelines are strictly followed, HBO
therapy is a modality with an acceptable rate of complications. The predominant
complication is represented by pressure equalization problems within the middle
ear. Serious complications rarely occur.
PMID- 10685585
TI - Intermittent hypobaric hypoxia induces altitude acclimation and improves the
lactate threshold.
AB - The physiological responses to short-term intermittent exposure to hypoxia in a
hypobaric chamber were evaluated. The exposure to hypoxia was compatible with
normal daily activity. The ability of the hypoxia program to induce hematological
and ventilatory adaptations leading to altitude acclimation and to improve
physical performance capacity was tested. Six members of a high-altitude
expedition were exposed to intermittent hypoxia and low-intensity exercise (in
cycle-ergometer) in the INEFC-UB hypobaric chamber over 17 d, 3-5 h x d(-1), at
simulated altitude of 4,000 m to 5,500 m. Following this hypoxia exposure
program, significant increases were found in packed cell volume (41 to 44.6%;
p<0.05), red blood cells count (4.607 to 4.968 10(6) cells x microL(-1); p<0.05),
and hemoglobin concentration (14.8 to 16.4 g x dL(-1); p<0.05), thus implying an
increase in the blood oxygen transport capacity. Significant differences in
exercise blood lactate kinetics and heart rate were also observed. The lactate
vs. exercise load curve shifted to the right and heart rate decreased, thus
indicating an improvement of aerobic endurance. These results were associated
with a significant increase in the ventilatory anaerobic threshold (p<0.05).
Significant increases (p<0.05) in pulmonary ventilation, tidal volume,
respiratory frequency, O2 uptake, CO2 output and ventilatory equivalents to
oxygen (VE/Vo2) and carbon dioxide (VE/co2) were observed at the ventilatory
threshold and within the transitional zone of the curves. We conclude that short
term intermittent exposure to moderate hypoxia, in combination with low-intensity
exercise in a hypobaric chamber, is sufficient to improve aerobic capacity and to
induce altitude acclimation.
PMID- 10685586
TI - Urinary continence in women during centrifuge exposure to high +Gz.
AB - BACKGROUND: One earlier study and anecdotal evidence suggest a possible
association between exposure to high +Gz forces and urinary incontinence in
women. High +Gz could possibly contributes to the prolapse of the bladder neck,
moving it into a position which decreases the leak point pressure resulting in
urinary incontinence. HYPOTHESIS: We tested the hypothesis that increased urinary
incontinence is associated with high +Gz. METHODS: 25 females were exposed to a
high +Gz profile. Following the exposure they were asked to answer a
questionnaire grading their urinary continence under high +Gz, and to provide a
baseline grading of their urinary continence at +1.0 Gz and under increased
abdominal stress at +1.0 Gz. Demographic data included parity and previous
urogenital surgery. Graded responses were dichotomized and data was analyzed
using Fischer's Exact Test for 2x2 tables with significance set at alpha = 0.05.
RESULTS: At high +Gz no significant association was found between reported urine
incontinence and a history of urogenital surgery or parity. Only one of twenty
five subjects had any symptoms at high +Gz despite the fact that five had a
predisposition. As expected, at +1.0 Gz and under increased abdominal stress at
+1.0 Gz a significant association was found between reported urine incontinence
and a history of urogenital surgery, while no significant association was found
for parity. CONCLUSIONS: In this simple first look there was no increase in
urinary incontinence at high +Gz even among those who reported a predisposition.
PMID- 10685587
TI - Heart rate and blood pressure responses to +Gz following varied-duration -Gz.
AB - BACKGROUND: The push-pull effect has been defined previously as decreased +Gz
tolerance caused by previous baseline zero or -Gz exposure. Earlier work
indicates that the delay in BP (BP) recovery during +Gz is a function of time at
G7, and is due to the lengthened time-course of sympathetically mediated
peripheral vasoconstriction. HYPOTHESIS: The purpose of this study was to
retrospectively determine whether heart rate (HR) varies with BP as duration at
preceding -Gz increased. METHODS: Continuous ECG R-R interval data from 15 s of
+2.25Gz after preceding 2, 5, 10, or 15 s at 2Gz obtained from previous
experiments were analyzed and compared with the previously reported BP data.
Repeated measures ANOVA and regression analyses were used to compare +2.25Gz HR
responses after the four -Gz conditions and one control +2.25Gz condition.
RESULTS: An initial rapid rise in HR was observed for all conditions with a
consistent steady-state plateau achieved after the first 7 s of +2.25Gz. However,
there were significant differences in mean HR attained during the +2.25Gz plateau
for preceding 15 s -2.0 Gz vs. the control, 2, 5, and 10s -Gz conditions (109+/
1.1 vs. 102+/-1.8, 100+/-2.0, 97+/-1.1 and 101+/-1.1, bpm, respectively; p<0.05).
CONCLUSIONS: HR, unlike BP, increases briskly across all preceding -Gz time
conditions, adapting within the initial baroreflex-compensatory time frame
typically expected for +Gz exposures. These results suggest there may be a
threshold effect for HR response. Consequently, vasoconstrictor response is a
critical adaptive mechanism during +Gz when preceded by long (>10 s) -Gz
exposures.
PMID- 10685588
TI - Vasomotor sympathetic nerve activity in men during bed rest and on orthostasis
after bed rest.
AB - BACKGROUND: Alterations in autonomic function are commonly seen during and after
spaceflight, and its ground-based analog, 6 degrees head-down bed rest (HDBR).
They may include peripheral vascular regulation, but vasomotor sympathetic
efferent nerve discharges to peripheral vasculatures have not been examined. The
aim of our study was to examine changes in vasomotor sympathetic nerve activity
during HDBR and under orthostasis after HDBR. METHODS: We performed 6 d of HDBR
on six male subjects, and measured muscle sympathetic nerve activity (MSNA)
together with plasma norepinephrine concentrations in the supine position before
HDBR and in 6 degrees head-down position on the sixth day (HDBR6) of HDBR. We
also measured MSNA in head-up tilt (HUT) test before and after HDBR. RESULTS: On
HDBR6, MSNA burst rate was the same (17+/-4 bursts x min(-1)) as that in supine
position before HDBR (15+/-2 bursts min(-1)), but plasma norepinephrine
concentrations were decreased to 1.14+/-0.10 pmol x ml(-1) compared with the
supine value before HDBR (1.56+/-0.20 pmol x ml(-1), p<0.05). After HDBR, supine
MSNA burst rate significantly increased by 58% to 24+/-4 bursts x min(-1). MSNA
increment in response to HUT was similar between before (34+/-3 bursts min(-1) x
sin HUT(-1)) and after (40+/-6 bursts x min(-1) x sin HUT(-1)) HDBR. CONCLUSIONS:
Our findings suggest that: a) the relationship between MSNA and plasma
norepinephrine concentrations was altered on the sixth day during HDBR; b) the
vasomotor sympathetic nerve activity was enhanced after HDBR; and c) the
augmentation of vasomotor sympathetic outflow to muscles under orthostasis was
preserved after HDBR.
PMID- 10685589
TI - Exercise thermoregulation in men after 1 and 24-hours of 6 degrees head-down
tilt.
AB - BACKGROUND: Exercise thermoregulation is dependent on heat loss by increased skin
blood flow (convective and conductive heat loss) and through enhanced sweating
(evaporative heat loss). Reduction of plasma volume (PV), increased plasma
osmolality, physical deconditioning, and duration of exposure to simulated and
actual microgravity reduces the ability to thermoregulate during exercise.
HYPOTHESIS: We hypothesized that 24 h of head down tilt (HDT24) would alter
thermoregulatory responses to a submaximal exercise test and result in a higher
exercise rectal temperature (Tre) when compared with exercise Tre after 1 h of
head down tilt (HDT1). METHODS: Seven men (31+/-SD 6 yr, peak oxygen uptake
(VpO2peak) of 44+/-6 ml x kg(-1) x min(-1)) were studied during 70 min of supine
cycling at 58+/-SE 1.5% VO2peak at 22.0 degrees C Tdb and 47% rh. RESULTS:
Relative to pre-tilt sitting chair rest data, HDT1 resulted in a 6.1+/-0.9%
increase and HDT24 in a 4.3+/-2.3% decrease in PV (delta = 10.4% between
experiments, p<0.05) while plasma osmolality remained unchanged (NS). Pre
exercise Tre was elevated after HDT24 (36.71 degrees C +/-0.06 HDT1 vs. 36.93
degrees C+/-0.11 HDT24, p<0.05). The 70 min of exercise did not alter this
relationship (p<0.05) with respective end exercise increases in Tre to 38.01
degrees C and 38.26 degrees C (degrees = 1.30 degrees C (HDT1) and 1.33 degrees C
(HDT24)). While there were no pre-exercise differences in mean skin temperature
(Tsk), a significant (p<0.05) time x treatment interaction occurred during
exercise: after min 30 in HDT24 the Tsk leveled off at 31.1 degrees C, while it
continued to increase reaching 31.5 degrees C at min 70 in HDT1. A similar
response (NS) occurred in skin blood velocity. Neither local sweating rates nor
changes in body weight during exercise of -1.63+/-0.24 kg (HDT1) or - 1.33+/-0.09
kg (HDT24) were different (NS) between experiments. CONCLUSION: While HDT24
resulted in elevated pre-exercise Tre, reduced PV, attenuation of Tsk and skin
blood velocity during exercise, the absolute increase in exercise Tre was not
altered. But if sweat rate and cutaneous vascular responses were similar at
different core temperatures (unchanged thermoregulation), the Tre offset could
have been caused by the HDT-induced hypovolemia.
PMID- 10685590
TI - Stretch- and H-reflexes of the lower leg during whole body cooling and local
warming.
AB - BACKGROUND: This study was undertaken to evaluate if possible changes in stretch-
and H-reflexes could be related to the changes in the EMG activity of the cooled
lower leg muscles observed during a stretch-shortening cycle exercise. METHODS:
Eight subjects wearing shorts and jogging shoes were exposed once to 27 degrees C
and twice to 10 degrees C for 60 min each. During the second exposure to 10
degrees C, the subject's lower legs were kept warm (10 degrees Clw) with
electrical pillows. After the exposures Achilles tendon reflex (stretch reflex)
was induced and the EMG activity of the triceps surae was measured. Immediately
after reflex measurements the EMG activity of the triceps surae and tibialis
anterior during a drop-jump (stretch-shortening cycle) was measured. After
similar thermal exposures electrically induced H-reflex from the calf was
measured. RESULTS: During the preactivity and stretch phases the EMG activity of
the triceps surae increased after the exposure to 10 degrees C, whereas during
the shortening phase it decreased. During the shortening phase cooling, on the
contrary, increased the activity of tibialis surae anterior. These changes
disappeared at 10 degrees Clw. At 10 degrees C the maximum EMG-amplitude of
triceps surae during stretch reflex decreased (p<0.05), reflecting suppressed
muscle spindle activity. Suppressed spindle activity causes the agonist to be
unfacilitated and the antagonist muscle contraction to be uninhibited, which was
seen in the present study as decreased agonist and increased antagonist EMG
activity during the shortening phase at 10 degrees C. The Hmax/Mmax-ratio, H
reflex latency and amplitude increased at 10 degrees C (p<0.05), reflecting
increased motoneuron pool excitability. This in part may explain the increased
EMG activity during the preactivity and stretch phases. CONCLUSION: Cooling
induced increase in the excitability of the motoneuron pool and suppression of
muscle spindle activity seem to be responsible of the EMG activity changes during
the stretch-shortening cycle, consequently decreasing muscular performance.
PMID- 10685591
TI - Improving athletic performance: is altitude residence or altitude training
helpful?
AB - Exercise training studies conducted at different altitudes (1250-5700 m) of
varying durations (30 min to 19 wk) are critically reviewed to determine the
efficacy of using altitude as a training stimulus to enhance sea level and
altitude exercise performance. Four strategies are discussed: a) exercise
training while residing at the same altitude; b) exercise training at altitude
but residing at sea level; c) exercise training at low altitude but residing at a
higher altitude; and d) exercise training under sea level and altitude conditions
but only after altitude acclimatization has occurred. Residing at altitude causes
a multitude of potentially beneficial physiological, ventilatory, hematological
and metabolic changes that theoretically should induce a potentiating effect on
endurance exercise performance. While it is accepted that endurance performance
is greatly enhanced at altitude, there is less support for the view that altitude
training while residing at altitude improves subsequent sea level endurance
performance. There is some evidence, though also not universally accepted, that
training at altitude but residing at sea level may benefit sea level endurance
performance. Most recently, the combination of "living high" (e.g., at 2500 m) to
obtain beneficial physiological changes associated with altitude acclimatization
and "training low" (e.g., at 1250 m) to allow maintenance of high-intensity
training is accumulating scientific and popular support as the most advantageous
strategy to improve subsequent sea level exercise performance in well-trained,
competitive runners.
PMID- 10685592
TI - Pulmonary cyst and cerebral arterial gas embolism in a hypobaric chamber: a case
report.
AB - This is a report of an aircrew member who suffered a serious physiological
incident in the form of pulmonary barotrauma and cerebral arterial gas embolism
during hypobaric chamber training, and who subsequently was shown to have a cyst
in the upper lobe of the left lung. The likely origin of the cyst is discussed,
as well as the aeromedical disposition following thoracotomy and apical
segmentectomy to remove the cyst.
PMID- 10685593
TI - In-flight cerebral oxygen status: continuous monitoring by near-infrared
spectroscopy.
AB - BACKGROUND: Little is known about the in-flight cerebral oxygen status (COS) of
fighter pilots. The purpose of this study was to evaluate the COS of fighter
pilots during an F-15DJ flight. METHODS: Three male F-15DJ fighter pilots
volunteered to serve as test subjects during aerial gunnery training (AGT)
missions. During the flight, the pilots' COS was continuously monitored from the
right forehead using a NIRO-300G near-infrared spectrophotometer. This new
instrument is capable of measuring the concentration changes in the brain of
oxygenated hemoglobin (O2Hb), reduced hemoglobin (HHb), total hemoglobin (cHb,
O2Hb + HHb), and the tissue oxygenation index (TOI, O2Hb/cHb). RESULTS:
Continuous changes of COS within the brain were clearly demonstrated using NIRO
300G, the changes included reductions in O2Hb, cHb, and TOI with increased +Gz,
in a mirror image fashion. The maximum decreased concentration of hemoglobin
during flight ranged from 12.8 to 25.6 micromol x L(-1) (of brain tissue).
CONCLUSIONS: We believe this study is the first monitoring of COS during F-15
actual flight. The monitoring of COS during F-15 flight showed that the effect of
+Gz was to simultaneously lower blood flow in a mirror image fashion. Our results
demonstrated that near-infrared spectroscopy (NIRO-300G) provides a reliable and
sensitive method for the monitoring of pilots' COS during flight.
PMID- 10685594
TI - Physiological problems associated with wearing NBC protective clothing during
cold weather.
AB - This report considers how thermal balance of soldiers wearing nuclear, biological
and chemical (NBC) protective clothing in combination with the Extreme Cold
Weather Clothing System (ECWCS) is affected during work in cold weather. A review
of published reports concerning physiological consequences of wearing NBC
protective clothing during cold exposure was completed. The findings reported in
the experimental literature were too limited to adequately forecast the effects
of adding NBC clothing to ECWCS. To remedy the information gap, simulation
modeling was employed to predict body temperature changes during alternating
bouts of exercise and rest throughout 8 h of exposure to three different severely
cold conditions. Published findings indicate that NBC protective clothing may
inadequately protect against hand and finger cooling, especially during rest
following strenuous activity. No evidence substantiates suggestions that wearing
NBC protective masks increases susceptibility to facial frostbite. Collectively,
the limited experimental work and the results of simulation modeling argue
against any increased risk of hypothermia associated with wearing NBC protective
clothing while working in the cold. However, wearing NBC protective clothing
during strenuous activity in cold weather may increase the risk of hyperthermia,
and cause sweat accumulation in clothing which may compromise insulation and
increase the risk of hypothermia during subsequent periods of inactivity.
PMID- 10685595
TI - Complementary medicine and aviation medicine.
PMID- 10685596
TI - NASA opens new virtual airport control tower at Ames.
PMID- 10685597
TI - Reports propose ways to better protect military troops from exposure to hazardous
agents.
PMID- 10685598
TI - Tubulin-tyrosine ligase, a long-lasting enigma.
AB - Tubulins and microtubules are subjected to several post-translational
modifications of which the reversible detyrosination/tyrosination of the carboxy
terminal end of most alpha-tubulins has been extensively analysed. This
modification cycle involves a specific carboxypeptidase and the activity of the
tubulin-tyrosine ligase (TTL). The true physiological function of TTL has so far
not been established. This review describes the purification of TTL to
homogeneity by biochemical methods, its in vitro properties and the generation of
monoclonal antibodies. These mabs not only enabled a very convenient and rapid
purification of TTL by immunoaffinity chromatography but also its extensive
characterization by protein sequencing, which led to the isolation of the full
length cDNA. With this information, gene disruption should be feasible in order
to determine the physiological significance of the tyrosination cycle.
PMID- 10685599
TI - The third tubulin pool.
AB - Tubulin normally undergoes a cycle of detyrosination/tyrosination on the carboxy
terminus of its alpha-subunit and this results in subpopulations of tyrosinated
tubulin and detyrosinated tubulin. Brain tubulin preparations also contain a
third major tubulin subpopulation which is non-tyrosinatable. This review
describes the purification and the structural characterization of non
tyrosinatable tubulin. This tubulin variant lacks a carboxyterminal glutamyl
tyrosine group on its alpha-subunit (delta2-tubulin). Delta2-tubulin is generated
from detyrosinated tubulin through an irreversible reaction. Delta2-tubulin
accumulates in neurons and in stable microtubule assemblies. It also accumulates
in some tumor cells due to the frequent loss of tubulin tyrosine ligase in such
cells. Delta2-tubulin may be a useful marker of malignancy in human tumors.
PMID- 10685600
TI - Interactions of bovine brain tubulin with pyridostigmine bromide and N,N'-diethyl
m-toluamide.
AB - Pyridostigmine bromide (PB), an inhibitor of acetylcholinesterase, has been used
as a prophylactic for nerve gas poisoning. N,N'-diethyl-m-toluamide (DEET) is the
active ingredient in most insect repellents and is thought to interact
synergistically with PB. Since PB can inhibit the binding of organophosphates to
tubulin and since organophosphates inhibit microtubule assembly, we decided to
examine the effects of PB and DEET on microtubule assembly as well as their
interactions with tubulin, the subunit protein of microtubules. We found that PB
binds to tubulin with an apparent Kd of about 60 microM. PB also inhibits
microtubule assembly in vitro, although at higher concentrations PB induces
formation of tubulin aggregates of high absorbance. Like PB, DEET is a weak
inhibitor of microtubule assembly and also induces formation of tubulin
aggregates. Many tubulin ligands stabilize the conformation of tubulin as
measured by exposure of sulfhydryl groups and hydrophobic areas and stabilization
of colchicine binding. PB appears to have very little effect on tubulin
conformation, and DEET appears to have no effect. Neither compound interferes
with colchicine binding to tubulin. Our results raise the possibility that PB and
DEET may exert some of their effects in vivo by interfering with microtubule
assembly or function, although high intracellular levels of these compounds would
be required.
PMID- 10685601
TI - Tubulin carboxypeptidase/microtubules association can be detected in the distal
region of neural processes.
AB - The association of tubulin carboxypeptidase with microtubules has been
demonstrated in crude brain extracts and in living non-nervous cells. Here, we
studied this phenomenon in cultured brain cells. To determine the association of
the enzyme with neural microtubules we isolated the cytoskeletons (detergent
extraction under microtubule-stabilizing conditions) and measured the content of
Tyr, Glu, and delta2 tubulin as a function of the in vitro incubation time of the
cytoskeletons. The carboxypeptidase was found associated with microtubules in 2
days-cultured cells but not in 7 days-cultured cells. Quantitative analysis of
digitized images after immunofluorescent staining revealed that detyrosination
during the incubation of the cytoskeletons occurred preferentially in the distal
regions of the neural processes. Prolonged taxol-treatment of the cells promoted
higher detyrosination but Tyr tubulin was not depleted suggesting the existence
of a subset of microtubules that has not associated carboxypeptidase and
therefore cannot be detyrosinated even after prolonged taxol-treatment. This
hypothesis was supported, although not conclusively, by additional experiments.
PMID- 10685602
TI - Tau protein function in axonal formation.
AB - Tau protein is a predominantly neuronal microtubule-associated protein that is
enriched in axons and is capable of promoting microtubule assembly and
stabilization. In the present article we review some of the key experiments
directed to obtain insights about tau protein function in developing neurons.
Aspects related to whether or not tau has essential, unique, or complementary
functions during axonal formation are discussed.
PMID- 10685603
TI - Tau dephosphorylation at tau-1 site correlates with its association to cell
membrane.
AB - It has been considered that tau protein is mainly a cytoplasmic protein since it
is a microtubule associated protein. However, it has also been suggested that tau
could be located in the cell nucleus and membrane. In our work, the cellular
distribution of tau has been studied by immunofluorescence and western blot
analysis, after subcellular fractionation in neuroblastoma cells and in tau
transfected non neural cells using, mainly, two types of tau antibodies; antibody
7.51 (that recognizes tau independent of its phosphorylation level); and antibody
Tau-1 (that recognizes tau only in its dephosphorylated form). Also, tau was
expressed in COS-1 cells to test for the features involved in the sorting of tau
to different cell localizations. Our results show that tau associated to cell
membrane has a lower phosphorylation level in its proline-rich region.
Additionally, in differentiated neuroblastoma cells, tau phosphorylation, at that
region, decreases and the amount of tau associated to cell membrane increases.
PMID- 10685604
TI - What is the signal for the posttranslational arginylation of proteins?
AB - The N-terminal, posttranslational arginylation of proteins is ubiquitous in
eukaryotic cells. Previous experiments, using purified components of the reaction
incubated in the presence of exogenous substrates, have shown that only those
proteins containing acidic residues at their N-terminals are arginylation
substrates. However, data from experiments that used crude extracts of brain and
nerve as the source of the arginylating molecules, suggest that the in vivo
targets for arginylation are more complex than those demonstrated using purified
components. One of the proposed functions for arginylation is as a signal for
protein degradation and proteins that have undergone oxidative damage have been
shown to be rapidly degraded. In the present experiments we have tested the
hypothesis that the presence of an oxidatively damaged residue in a protein is a
signal for its arginylation. These experiments have been performed by adding
synthetic oxidized peptides to crude extracts of rat brain, incubating them with
[3H]Arg and ATP and assaying for arginylated peptides using RP-HPLC. Results
showed that while the oxidized A-chain of insulin was arginylated in this system,
confirming previous experiments, other peptides containing oxidized residues were
not. When a peptide containing Glu in the N-terminus was incubated under the same
conditions it too was not a substrate for arginylation. These findings show that
neither the presence of an N-terminal acidic residue nor an oxidized residue
alone are sufficient to signal arginylation. Thus, another feature of the
oxidized A-chain of insulin is required for arginylation. That feature remains to
be identified.
PMID- 10685605
TI - Differential association of tau with subsets of microtubules containing
posttranslationally-modified tubulin variants in neuroblastoma cells.
AB - Neuronal cells display different subsets of dynamic microtubules. In axons and
extending neurites, this intrinsic dynamics is modulated by the microtubule
associated protein tau. Moreover, posttranslational modifications of tubulin,
namely acetylation, tyrosination or glutamylation are directly involved in
determining the stability of neuronal microtubules. Studies were carried out to
analyze the interaction patterns of tau with subsets of microtubules in N2A
neuroblastoma cells, which can differentiate in the presence of dibutyryl cAMP.
Double labeling studies showed a differential pattern of tau association with
microtubules containing acetylated and tyrosinated tubulin. Furthermore, studies
using depolymerizing drugs revealed a selectivity in the association of tau with
microtubular polymers and microfilaments, within the organization of the neuronal
cytoskeleton. In order to study the association of specific tau isoforms with
microtubules containing modified tubulin variants, immunoprecipitation studies
were carried out. The coimmunoprecipitation data indicated a selective binding of
specific tau isoforms to either modified tubulin variant. To assess the
hypothesis on the roles of tau isoforms in the stabilization of microtubules
containing modified tubulins, the association of those variants with tau isoforms
was analyzed in overlay experiments. A preferential binding of acetylated tubulin
from undifferentiated N2A cell extracts, to at least one slow-migrating tau
isoform was revealed. However, acetylated tubulin from N2A cells containing long
neurites displayed a preferential association with two isoforms of tau. On the
other hand, tyrosinated tubulin from N2A extracts bound to the entire set of
neuronal tau isoforms. These studies, along with the tau association with
microtubules with different stability, indicate that tau segregates into subsets
of microtubules in the axonal processes. The studies also suggest that these
interactions may respond to a functional versatility of these polymers in
differentiating neurons.
PMID- 10685606
TI - Post-translational arginylation of proteins in cultured cells.
AB - The aim of this study was to analyze the N-terminal post-translational
incorporation of arginine into cytosolic proteins from cultured cells and the in
vitro incorporation of arginine into soluble proteins of PC12 cells after serum
deprivation. Arginine incorporation was measured in the presence of protein
synthesis inhibitors. None of the inhibitors used affected significantly the
arginylation reaction while the novo synthesis of protein was reduced by 98%.
Under these conditions, we found that of the total [14C]arginine incorporated
into the proteins, around 20% to 40% was incorporated into the N-terminal
position of soluble proteins by a post-translational mechanism. These results
suggest that this post-translational aminoacylation may be a widespread reaction
in neuronal and non-neuronal cells. We also found that in PC12 cells, the in
vitro post-translational arginylation was 60% higher in apoptotic cells with
respect to control cells. These findings suggest that the post-translational
arginylation of proteins may be involved in programmed cell death.
PMID- 10685607
TI - Epifluorescence microscopy of surface domain microheterogeneity in myelin
monolayers at the air-water interface.
AB - Myelin lipids form liquid-expanded monolayers at the air-water interface, with no
evidence of surface pressure-induced two-dimensional phase transition. However,
the film doped with 2 mole % of the fluorescent probe N-(7-nitro-2-1,3
benzoxadiazol-4-yl) Diacyl Phosphatidyl-ethanolamine (NBD-PE) shows an irregular
pattern of coexisting laterally segregated surface domains with diffuse
boundaries that change from smooth patterns to fractal-like structures depending
on surface pressure. Successive expansion-recompression cycles lead to more
defined domains, with a general reorganization occurring at surface pressures of
about 20 mN/m. At least two coexisting phases occur over almost all the
compression isotherms. The presence of proteins in whole myelin monolayers
induces defined domain textures with relatively sharp boundaries. The patterns
during compression and expansion are quite similar and, after the first cycle,
little changes occur under recompression. The patterns observed provide
topographical evidence for the existence of dynamic domain microheterogeneity in
the surface of myelin interfaces.
PMID- 10685608
TI - Myelin membranes isolated from rats intracranially injected with apotransferrin
are more susceptible to in vitro peroxidation.
AB - Purified myelin obtained from 17 day old rats intracranially injected with aTf at
3 days of age was submitted to in vitro peroxidation using Fe + ascorbic acid
(FeA) or Cu + H2O2 (CuH), to investigate the susceptibility of this membrane to
in vitro metal catalyzed peroxidation. There was an increase in thiobarbituric
acid-reactive-substances (TBARS) (60%) and in protein-associated carbonyls (PAC)
(20%) in the myelin from aTf injected rats in comparison to myelin from controls,
indicating a higher susceptibility to peroxidation. Desferoxamine (DFX) injected
simultaneously with aTf did not change the response of myelin to aTf. CNS myelin
is highly vulnerable to oxidative stress, and its susceptibility to peroxidation
increases in myelin isolated from aTf injected rats. This increased liability to
peroxidation as well as the previously reported aTf-dependent increment in
certain myelin proteins and lipids and in the expression of specific myelin
mRNAS, does not appear to be due to an increased amount of iron bound to the
injected aTf. The changes in composition that we have previously reported could
result in an abnormal myelin, allowing the peroxidative system to act upon the
membrane more easily than in normal circumstances.
PMID- 10685609
TI - Regulation of signaling by protein-tyrosine phosphatases: potential roles in the
nervous system.
AB - During neuronal development, cells respond to a variety of environmental cues
through cell surface receptors that are coupled to a signaling transduction
machinery based on protein tyrosine phosphorylation and dephosphorylation.
Receptor and non-receptor tyrosine kinases have received a great deal of
attention; however, in the last few years, receptor (plasma membrane associated)
and non-receptor protein-tyrosine phosphatases (PTPs) have also been shown to
play important roles in development of the nervous system. In many cases PTPs
have provocative distribution patterns or have been shown to be associated with
specific cell adhesion and growth factor receptors. Additionally, altering PTP
expression levels or activity impairs neuronal behavior. In this review we
outline what is currently known about the role of PTPs in development,
differentiation and neuronal physiology.
PMID- 10685610
TI - Multiple forms of phosphatase from human brain: isolation and partial
characterization of affi-gel blue binding phosphatases.
AB - Implication of protein phosphatases in Alzheimer disease led us to a systemic
investigation of the identification of these enzyme activities in human brain.
Human brain phosphatases eluted from DEAE-Sephacel with 0.22 M NaCl were resolved
into two main groups by affi-gel blue chromatography, namely affi-gel blue
binding phosphatases and affi-gel blue-nonbinding phosphatases. Affi-gel blue
binding phosphatases were further separated into four different phosphatases,
designated P1, P2, P3, and P4 by calmodulin-Sepharose 4B and poly-(L-lysine)
agarose chromatographies. These four phosphatases exhibited activities towards
nonprotein phosphoester and two of them, P1 and P4, could dephosphorylate
phosphoproteins. The activities of the four phosphatases differed in pH optimum,
divalent metal ion requirements, sensitivities to various inhibitors and
substrate affinities. The apparent molecular masses as estimated by gel
filtration for P1, P2, P3, and P4 were 97, 45, 42, and 125 kDa, respectively. P1
is markedly similar to PP2B from bovine brain and rabbit skeletal muscle. P4 was
labeled with anti-PP2A antibody and may represent a new subtype of PP2A. P1 and
P4 were also effective in dephosphorylating Alzheimer disease abnormally
hyperphosphorylated tau (AD P-tau). The resulting dephosphorylated AD P-tau had
its activity restored in promoting assembly of microtubules in vitro. These
results suggest that P1 and P4 might be involved in the regulation of
phosphorylation of tau in human brain, especially in neurodegenerative conditions
like Alzheimer's disease which are characterized by the abnormal
hyperphosphorylation of this protein.
PMID- 10685611
TI - Kinetics of Na+, K+-ATPase inhibition by an endogenous modulator (II-A).
AB - We have previously reported the isolation by gel filtration and anionic exchange
HPLC of two brain Na+, K+-ATPase inhibitors, II-A and II-E, and kinetics of
enzyme interaction with the latter. In the present study we evaluated the
kinetics of synaptosomal membrane Na+, K+-ATPase with II-A and found that
inhibitory activity was independent of ATP (2-8 mM), Na+ (3.1-100 mM), or K+ (2.5
40 mM) concentration. Hanes-Woolf plots showed that II-A decreases Vmax in all
cases; KM value decreased for ATP but remained unaltered for Na+ and K+,
indicating respectively uncompetitive and noncompetitive interaction. However, II
A became a stimulator at 0.3 mM K+ concentration. It is postulated that brain
endogenous factor II-A may behave as a sodium pump modulator at the synaptic
region, an action which depends on K+ concentration.
PMID- 10685612
TI - Two glycogen synthase activities associated with proteoglycogen in retina.
AB - Glycogen synthase of bovine retina was found associated with the acid-insoluble
and acid-soluble proteoglycogen fractions. The synthase associated with the acid
insoluble proteoglycogen precursor showed an 8-fold lower Km for UDP-glucose than
the synthase associated with the acid-soluble fraction, and was inhibited by
detergent. A short digestion with pronase resulted in conversion of the acid
insoluble fraction into acid-soluble. The results lead us to postulate that the
acid-insolubility of the proteoglycogen fraction and the association with retina
membrane proposed before, is caused by glycogen synthase strongly associated to
its polysaccharide moiety. The enlargement of the polysaccharide moiety during
proteoglycogen biosynthesis, from glycogenin linked to a few 11 to 12 glucose
units to the acid-insoluble proteoglycogen precursor (Mr 470,000) would be
carried out, together with the branching enzyme, by the glycogen synthase showing
a low Km for UDP-glucose. The glycogen synthase with the highest Km for UDP
glucose would participate in conversion of the precursor into mature acid-soluble
proteoglycogen.
PMID- 10685613
TI - Scinderin, a Ca2+-dependent actin filament severing protein that controls
cortical actin network dynamics during secretion.
AB - Secretory vesicles are localized in specific compartments within neurosecretory
cells. These are different pools in which vesicles are in various states of
releasability. The transit of vesicles between compartments is controlled and
regulated by Ca2+, scinderin and the cortical F-actin network. Cortical F-actin
disassembly is produced by the filament severing activity of scinderin. This Ca2+
dependent activity of scinderin together with its Ca2+-independent actin
nucleating activity, control cortical F-actin dynamics during the secretory
cycle. A good understanding of the interaction of actin with scinderin and of the
role of this protein in secretion has been provided by the analysis of the
molecular structure of scinderin together with the use of recombinant proteins
corresponding to its different domains.
PMID- 10685614
TI - Glucosylceramide synthesized in vitro from endogenous ceramide is uncoupled from
synthesis of lactosylceramide in Golgi membranes from chicken embryo neural
retina cells.
AB - It is known that ceramide (Cer), the precursor of sphingoglycolipids and of
sphingomyelin, participates in events leading to activation of the apoptotic
pathway, and per se or through conversion to glucosylceramide (GlcCer) modulates
formation of neuritic processes in developing neurons. To learn about the fate of
de novo synthesized Cer and GlcCer we examined, in Golgi membranes from chicken
embryo neural retina cells, the metabolic relationships of endogenous Cer, GlcCer
and lactosylceramide (LacCer). Incubation of the membranes with UDP-[3H]Glc
revealed a pool of endogenous Cer useful for synthesis of GlcCer. Most of the
GlcCer synthesized, however, was not used for synthesis of LacCer, indicating
that it was functionally uncoupled from LacCer synthase. On the other hand,
incubation with UDP-[3H]Gal revealed a pool of endogenous GlcCer that depending
of the integrity of the membranes was functionally coupled to LacCer and
ganglioside synthesis. These results indicate that most GlcCer formed in vitro
from Cer is topologically segregated from the synthesis of LacCer. However,
subfractionation in sucrose gradients of Golgi membranes labeled with both
precursors failed to separate membranes enriched in [3H]GlcCer from those
enriched in [3H]Gal-labeled LacCer. It is concluded that despite both transfer
steps co-localize in the Golgi membranes, coupling of GlcCer synthesis to LacCer
synthesis requires conditions not present in our in vitro assay. This suggests
that a coupling activity exists that could be relevant for regulation of the
cytoplasmic levels of Cer and GlcCer.
PMID- 10685616
TI - Ganglioside expression during differentiation of chick retinal cells in vitro.
AB - The neural retina has been widely used to study the developmental patterns of
ganglioside metabolism. Recent findings about in vitro differentiating chick
embryo retina cells showed that: a) GD3 and GD1a ganglioside patterns undergo the
most dramatic changes; b) when the cells emit neurites, GD3 ganglioside and a
group of complex gangliotetraosylgangliosides (GTOG) are transiently coexpressed;
c) synchronized developmental phenomena are dissociated by anti-GM1 antibodies;
d) GD3 remains as a major ganglioside in differentiated neurons, though it is
almost not immunoexpressed; e) GTOG affect antibody binding to GD3; f) the
content of gangliosides involved in neural differentiation modifies their
immunostain localization on cell membrane; g) after exogenous GTOG uptake,
immature neurons mimic GD3 immunofluorescent localization of mature cells; h) a
subset of purified retinal ganglion cells express GTOG characteristic of mature
neurons.
PMID- 10685615
TI - Immediate early gene expression within the visual system: light and circadian
regulation in the retina and the suprachiasmatic nucleus.
AB - Immediate early genes are a family of genes that share the characteristic of
having their expression rapidly and transiently induced upon stimulation of
neuronal and non-neuronal cells. In this review, first a short description of the
IEGs is given, then it is discussed the stimulus-induced and circadian-induced
variations in the expression of IEGs in the visual system, mainly in the retina
and the suprachiasmatic nucleus. The possible physiological consequences of these
variations in IEG expression are also considered. Finally, we refer to two
aspects of our recent studies and those of other laboratories involving light
driven IEG expression. The first is the finding that in the chick retina, the
expression of c-fos is differentially modulated in the different cell types and
that c-fos regulates the synthesis of the quantitatively most important lipids of
all cells, the phospholipids, by a non-genomic mechanism. The second is the
occurrence of differential waves of IEG expression in the mammalian
suprachiasmatic nucleus regarding light induction or spontaneous oscillations.
PMID- 10685618
TI - The effectiveness of rehabilitation: a critical review of the evidence.
Introduction.
PMID- 10685617
TI - Expression of a neuronal nicotinic acetylcholine receptor in insect and mammalian
host cell systems.
AB - Different mammalian and insect somatic host cell systems were tested in their
ability to express, fold, and assemble alpha7-type neuronal acetylcholine
receptor (AChR) both at the transcriptional and translational level. For this
purpose we employed clonal cell lines derived from the neural crest, such as PC12
cells from a rat adrenal pheochromocytoma, and GH3 cells isolated from a rat
pituitary tumor, as well as non-neuronal cells such as NIH-3T3 fibroblasts from
embryonic NIH Swiss mouse and Sf9 cells from ovary tissue of the Spodoptera
frugiperda butterfly. Total RNA, isolated from either transfected or non
transfected PC12, GH3 or 3T3 cells, or recombinant AcNPV-infected and mock
infected Sf9 cells was analyzed by Northern blot. PC12 cells, which endogenously
express alpha7 AChR, and all its heterologous alpha7-transfectant clones,
exhibited variable but generally high amounts of a single transcript. GH3 and NIH
3T3 transfectant clones and recombinant AcNPV-infected Sf9 cells expressed
variable levels of alpha7-mRNA, with a single transcript that co-migrated with
the 28S rat rRNA. Only the neural crest-derived cell lines appeared to
functionally express the alpha7 AChR, as measured by their [125I]alpha
bungarotoxin binding ability. The results suggest that heterologous expression of
alpha7 is regulated not at the transcriptional, but at the postranslational level
and that not all host cell systems appear to express the cellular factors needed
for the correct postranslational modifications leading to mature and functional
alpha7 AChR. Furthermore, the results suggest that tightly controlled expression
mechanisms have evolved in parallel with this ancient cholinergic sequence.
PMID- 10685619
TI - Effectiveness of brain injury rehabilitation.
AB - Despite the problems posed by diversity of condition and the lack of agreement
among researchers over what outcome to measure, there is now increasingly robust
evidence for the effectiveness of rehabilitation in brain-injured populations.
Meta-analysis has demonstrated clearly that stroke units provide a better outcome
than management on a general medical ward, at the level of survival, discharge
destination and dependency. The extent of this advantage may be summarized in the
following terms. For every 100 patients treated in a stroke unit, four deaths and
two institutional admissions are avoided, and five patients are discharged home.
This benefit appears to arise from a combination of good-quality acute management
and the coordinated input of a multidisciplinary team. Therapy programmes are
shown to be of benefit and intensive therapy programmes of somewhat greater
benefit. Smaller numbers and heterogeneity among the head-injured population tend
to confound randomized controlled trial designs, but there is no good reason to
suppose that brain injury resulting from trauma should be less responsive to
similar good management principles than that arising from stroke. In any event,
we have progressed to a stage where the weight of evidence supports the notion
that rehabilitation is effective, and nontreatment controls are ethically no
longer acceptable. It is time now to unravel the threads of rehabilitation and
consider which are the critical components. There are still many opportunities
for comparison of different models for delivery of care, and the existing
evidence for these is discussed.
PMID- 10685620
TI - Effectiveness of spinal cord injury rehabilitation.
AB - As in other areas of rehabilitation, relatively small numbers and diversity--both
of condition and of patients' goals--hinder the assimilation of robust evidence
for the effectiveness of rehabilitation. Patients with spinal cord injury (SCI)
tend to be gathered together in a small number of regional services, each with
their own philosophy and each with different attitudes to outcome measurement,
and thus collection of the existing trials for meta-analysis is problematic. The
marked improvement in outcome from SCI that has occurred with the development of
specialist rehabilitation programmes argues strongly for the effectiveness of
rehabilitation, and we have progressed beyond the point where randomized
controlled trials that deny a group such intervention could be considered
ethical. Current research is aimed at teasing apart the aspects of different care
models that are most effective, or the evidence for the usefulness of
interventions for control of symptoms such as spasticity and pain. This evidence
is reviewed and discussed.
PMID- 10685621
TI - Effectiveness of rehabilitation for multiple sclerosis.
AB - Unlike other areas of rehabilitation, which typically follow a single incident
such as trauma or stroke and are followed by improvement (or at least an
expectation of stable impairment), multiple sclerosis (MS) presents the problem
of progressive impairment and disability. In addition the nature and course of
this progression are variable, so that the population is heterogeneous.
Expectations for outcome must be modest, and measurement should be focused on
quality on life issues. On a background of pre-existing complex disability,
multiple single-case (before and after) study designs often present the best
evidence for effectiveness of the team approach and for specific interventions.
This evidence is presented and reviewed.
PMID- 10685622
TI - Effectiveness of rehabilitation following amputation.
AB - For many patients, the outcome of rehabilitation following amputation depends
substantially on comorbidity. This is particularly so where amputation is
performed because of peripheral vascular disease which may involve other end
organs, but also applies in trauma where loss of limb may not be the only injury.
In evaluating outcome, measures must take account of the very different goals for
rehabilitation. These may range from cosmesis or the simple ability to transfer
from bed to chair, to successful competition in the Para-Olympics. Rehabilitation
programmes for amputees are not simply prosthetic services, but must take account
of the whole patient, their goals and ambitions. Research to date has made a
contribution in identifying prognostic factors for prosthetic rehabilitation,
thus helping to target limited resources. Controlled studies are still required,
however, to establish the optimum services to offer to different groups of
patients.
PMID- 10685623
TI - Effectiveness of rehabilitation in arthritis.
AB - If rehabilitation aims to improve function, the demonstration of its
effectiveness requires functional assessment, rather than the standard clinical
and laboratory tests beloved of many rheumatologists. Medical interventions are
not often evaluated for their contribution to improved function, and this
omission must be addressed in the future. The evidence, where it is available,
supports a multidisciplinary approach, but increasingly stresses the importance
of partnership with the patient, passing back to them the responsibility for
maintaining their own exercise programmes and involvement in activities. However,
the provision of background support appears to be essential to continued
independence. Evidence for the various interventions is reviewed.
PMID- 10685625
TI - The effectiveness of rehabilitation: a critical review of the evidence. Closing
remarks
PMID- 10685624
TI - Effectiveness of rehabilitation for spinal pain.
AB - The evidence for effectiveness of different approaches is often diluted by the
inclusion of heterogeneous groups and, in this case, lack of agreement over what
constitutes 'acute' and 'chronic' back pain is a clear confounding factor.
Although there are undoubtedly common issues in the approach to these problems,
there are also clear differences. Closer definition of the problem and the
development of specific and targeted outcome measures is required. In common with
other areas of musculoskeletal rehabilitation, the evidence strongly supports
exercise (except possibly in the rare case of true radicular back pain) and a
cognitive behavioural approach to pain management. The variability of evidence in
support of manipulation suggests that patient selection is important, but as yet
those selection criteria are not clear. As is often the case, medical
interventions are rarely submitted to evaluation in terms of functional outcome
so, for procedures such as epidurals and facet joint injections, the jury is
still out at the current time.
PMID- 10685626
TI - The Consensus Conference on the treatment of in situ ductal carcinoma of the
breast, April 22-25, 1999.
PMID- 10685627
TI - Intramucosal cysts in the gastric body of patients with Zollinger-Ellison
syndrome.
AB - To ascertain the frequency and the clinico-functional correlations of
intramucosal cysts in the gastric body of patients with the Zollinger-Ellison
syndrome (ZES) and to clarify the relevant mechanism of development, a total of
106 consecutive ZES patients (58 M, 48 F; mean age: 53 yrs, range 19-93 yrs) were
investigated with a mean of 7.2 biopsy specimens of the body mucosa per patient
proved to be suitable for the study. Biopsies of endoscopically detectable
polypoid lesions were not considered. Cystic changes were evaluated with respect
to their severity by assessing the cyst grade (0, absent, 1; <30%, 2; 30-60%; 3
>60% of the mucosal area of the biopsy specimen of individual patients showing
the most pronounced finding, respectively) and to their intragastric distribution
by assessing the ratio of biopsy specimens showing cystic changes over the total
number of biopsies examined in each patient. Intramucosal cysts were found in
biopsies of non-polypoid gastric body mucosa in 71.7% of 106 patients with
Zollinger-Ellison syndrome (ZES) and showed grade 2 and 3 severity in 22 and 8
cases, respectively. The severity of cystic changes correlated with the gastrin
levels (p = 0.0005) and was more advanced in patients with active than in those
with cured disease (p = 0.037). In the former group, furthermore, advanced cystic
changes correlated with age (p = 0.03), male gender (p = 0.014), years of disease
from onset (p < 0.02), years of omeprazole treatment (p = 0.033), basal acid
output (p < 0.02), severity of ECL cell proliferative changes (p = 0.028), and
absence of previous gastrinoma resection (p = 0.039) whereas they did not
correlate with MEN-1 status, gastritis, maximal acid output, total duration of
any antisecretory drug treatment, daily doses of omeprazole (> 20 mg vs 20 mg),
years from surgery, duodenal localization of gastrinoma(s), presence of gastric
carcinoid tumor(s) and of liver metastases. In groups of patients subdivided
according to three levels of serum gastrin, the duration of omeprazole treatment
was not related to the severity of cystic changes. It is concluded that
intramucosal cysts in non polypoid gastric body mucosa of ZES patients are by far
more common than the already reported fundic gland polyps, to which they likely
give raise. Circulating levels of gastrin have an important independent role in
their development.
PMID- 10685628
TI - Cells producing cathepsins D, B, and L in human breast carcinoma and their
association with prognosis.
AB - Lysosomal proteinases, cathepsins D, B, and L have been associated with malignant
tumor progression and with prognosis in various human carcinomas. In the current
study, the immunohistochemical localization of cathepsins in tumor cells was
correlated with cathepsin protein concentration in breast carcinoma cytosols from
77 patients. Significant correlation was found for cathepsin D (P < .041) and
borderline correlation for cathepsin B (P < .055) but not for cathepsin L. We
hypothesize that the poor correlation of cysteine cathepsins was attributable to
the fact that they were present not only in malignant epithelial cells, but also
in infiltrating macrophages and stromal fibroblasts. In addition, tumor
surrounding myoepithelial cells (42% of tumors) and myofibroblasts (26% of
tumors) as well as endothelial cells of neovasculature (10% of tumors) all
stained specifically for cathepsin B. Two thirds of tumors co-expressed
cathepsins B and L in tumor cells, whereas only 17% of tumors co-expressed all 3
cathepsins. Intense immunostaining for cathepsin D of tumor cells was observed in
tumors at high TNM stage and tumors having positive lymph nodes. The expression
of cathepsin B was independent of established prognostic factors, whereas intense
cathepsin L staining in tumor cells was associated with high histological grade.
With respect to prognosis of patient survival, only tumor cell-associated
cathepsin D (P = .042) and myoepithelial cell-associated cathepsin B (P = .061)
showed borderline significance. Cathepsins B and L immunostaining in tumor cells
was not prognostic. In contrast, cytosolic levels of cathepsin B correlated with
higher rate of relapse. Taken together, these results show the diversity in the
cellular distribution of cathepsins in human breast carcinoma, presumably
reflecting specific regulation and function of each of the cathepsins during
tumor progression.
PMID- 10685629
TI - Unusual bone marrow manifestations of parvovirus B19 infection in
immunocompromised patients.
AB - Parvovirus B19 is responsible for a spectrum of disease in humans. The usual bone
marrow findings in acute parvovirus infections are marked erythroid hypoplasia
and occasional giant erythroblasts. Intranuclear inclusions in developing
erythroid precursors are rarely described in children or adults with parvovirus
infection, although abundant intranuclear inclusions are commonly observed in the
placenta and other tissues in infected fetuses. In this study, 8 patients are
reported in whom the first evidence of parvovirus infection was the recognition
of numerous intranuclear inclusions in erythroid precursors on bone marrow biopsy
sections. Six of the 8 patients had documented immunodeficiencies; 4 had acquired
immune deficiency syndrome (AIDS), and 2 were on chemotherapy. Five of 7 patients
were negative for immunoglobulin G (IgG) antiparvovirus antibodies, including all
4 with AIDS. Unlike the typical pattern in parvovirus infection, the bone marrow
was hypercellular in most of the patients, and erythroid precursors were usually
increased with the entire spectrum of normoblast maturation represented; abundant
intranuclear inclusions were observed similar to the finding in fetuses. The
inclusions were variably eosinophilic and compressed the chromatin against the
nuclear membrane. In situ hybridization showed parvovirus B19 DNA in numerous
erythroid precursors in all cases. The findings of erythroid maturation and
abundant viral inclusions in these immunocompromised patients is consistent with
the hypothesis that failure to produce effective IgG parvovirus neutralizing
antibodies may lead to persistent infection through viral tolerance that allows
erythroid development of infected cells past the pronormoblast stage.
Identification of parvovirus inclusions in marrow biopsies and subsequent
confirmation of infection by in situ hybridization can be important in the
assessment of anemia in immunodeficient patients because serological studies for
parvovirus B19 are frequently negative.
PMID- 10685630
TI - Frequent c-myc and Int-2 overrepresentations in nasopharyngeal carcinoma.
AB - Nasopharyngeal carcinoma (NPC) is a commonly occurring tumor in southern China.
Although several causative factors have now been recognized, the genetic basis
underlying its tumorigenesis is still unclear. To identify potential chromosomal
aberrations for further investigations, comparative genomic hybridization (CGH)
analysis was applied to the study of genomic imbalances in 10 NPC biopsy
specimens. Before CGH analysis, the tumor cell content within the biopsy
specimens was enriched by tissue microdissection, and universal genome
amplification was performed on the recovered DNA. Recurrent chromosomal gains
were detected on 1q (6 of 10 cases), 2q (5 of 10 cases), 3q (7 of 10 cases), 6p
(8 of 10 cases), 6q (5 of 10 cases), 7q11.2 (4 of 10 cases), 8q (6 of 10 cases),
11q13, 12, and 15q (8 of 10 cases each), 17q (6 of 10 cases), and 20q (5 of 10
cases). Common losses were identified on 3p (5 of 10 cases), 9p (5 of 10 cases),
11q14-qter (8 of 10 cases), and 14q (5 of 10 cases). Among these aberrations, 7,
8, and 11 gains were further investigated on a series of NPC tissue samples, by
interphase fluorescent in situ hybridization (FISH), for the incidence of alpha
satellites: 7, 8, and 11 c-myc and Int-2. Low-level increases of alpha-satellite
7 (9 of 34 cases; 26.5%), alpha-satellite 8 (15 of 34 cases; 44%), and alpha
satellite 11 (8 of 32 cases; 25%) were detected, whereas high-level copy gains of
c-myc (21 of 34 cases; 62%) and Int-2 (26 of 34 cases; 76.5%) were more
frequently found. Our series is the first to identify genomic overrepresentations
of c-myc and Int-2 in NPC. The high incidence of Int-2 amplifications strongly
suggests a role of this proto-oncogene in the pathogenesis of NPC.
PMID- 10685631
TI - Expression of Bcl-2 familial proteins is reduced in small bile duct lesions of
primary biliary cirrhosis.
AB - In primary biliary cirrhosis, biliary epithelial cell death by apoptosis results
in progressive bile duct loss. We examined immunohistochemically 4 apoptosis
regulating bcl-2 familial proteins (bcl-2, mcl-1, bcl-X, and bax) in the biliary
epithelium in 19 cases of primary biliary cirrhosis. Ten cases of chronic
hepatitis C, 9 cases of extrahepatic biliary obstruction, and 10 cases of normal
liver were used as a control. Bcl-2 and mcl-1 are inhibitors of apoptosis, bcl-X,
probably bcl-XL in biliary epithelial cells, an inhibitor, and bax, a promoter of
apoptosis. First, we clarified the distribution of bcl-2 familial proteins on the
intrahepatic biliary tree in normal livers. Bcl-2 was detected in the
interlobular bile ducts and bile ductules, but not in the large and septal bile
ducts in all cases examined. Mcl-1, bcl-X, and bax were diffusely detectable at
the any level of the intrahepatic biliary tree, with a staining pattern that was
diffuse and cytoplasmic. This distribution pattern was preserved in extrahepatic
biliary obstruction. Bcl-2 expression was lost or markedly reduced in the damaged
interlobular bile ducts in primary biliary cirrhosis, whereas the reduction was
only focal or mild in the bile ducts with hepatitis-associated damage in chronic
hepatitis C. Expression levels of mcl-1, bcl-X, and bax were similarly reduced to
that of bcl-2 in these 2 diseases. These findings suggest that bax is not
important as a proapoptotic factor in the damaged bile ducts and that
downregulation of bcl-2 and mcl-1, and probably that of bcl-XL, leads to a
decrease in the threshold of apoptosis and increase in the vulnerability to
apoptotic stimuli in these bile ducts, followed by the progressive apoptotic loss
of interlobular bile ducts, in primary biliary cirrhosis.
PMID- 10685632
TI - Expression of hepatocyte growth factor (HGF)/scatter factor and its receptor c
MET correlates with poor prognosis in synovial sarcoma.
AB - The hepatocyte growth factor (HGF)/c-MET signaling system plays an important role
in the carcinogenesis of various organs. We investigated the expression of HGF
and its receptor c-MET by immunohistochemistry (IHC) in 69 cases of synovial
sarcoma and compared the findings with clinicopathologic parameters,
proliferating activities evaluated by MIB-1 labeling index (MIB-1 LI), and
patients' prognosis. Furthermore, mRNA analysis of HGF, c-MET, and SYT-SSX fusion
gene was performed by reverse transcriptase-polymerase chain reaction (RT-PCR) in
22 concordant frozen materials. Twenty-one of 69 (30.4%) tumors showed positive
reaction for c-MET, whereas 22 tumors (31.9%) were positive for HGF. In 10 cases,
co-expression of HGF and c-MET was observed; however, there was no significant
correlation between HGF and c-MET expression. HGF expression was correlated with
female patients, large tumors (more than 5 cm), the presence of rhabdoid cells,
low frequency of mast cells (<20/10 HPF), high nuclear grade (grade III), and
high American Joint Committee (AJC) stage (III and IV). Conversely, c-MET
expression was only correlated with large tumors. However, the coexpression of
HGF and c-MET was significantly correlated with large tumor size, the existence
of rhabdoid cells, and high AJC stage. Both the expression of HGF and the co
expression of HGF and c-MET showed a significantly high MIB-1 LI and were
correlated with poor prognosis according to univariate analysis. Multivariate Cox
analysis showed that high AJC stage, the expression of HGF, and a high MIB-1 LI
(12.0>) independently had a negative impact on overall survival. In 22 frozen
material cases evaluated by both IHC and RT-PCR, a statistically significant
correlation was found between the 2 techniques. SYT-SSX fusion transcripts were
detected in all 22 cases. Three tumors had SYT-SSX2 fusion transcripts, whereas
19 had SYT-SSX1 phenotype. Our results suggest that HGF/c-MET paracrine signaling
may contribute to tumorigenesis and progression in synovial sarcoma.
PMID- 10685633
TI - Expression of matrix metalloproteinase-2 (MMP-2) and of membrane-type-1-matrix
metalloproteinase (MT1-MMP) in transitional cell carcinoma of the upper urinary
tract.
AB - Tumor cell invasion and metastasis are biologically dependent on the proteolytic
destruction of surrounding matrix components. Matrix metalloproteinase-2 (MMP-2)
is able to cleave type IV collagen, and membrane-type-1-matrix metalloproteinase
(MT1-MMP) induces activation of proMMP-2. We investigated the expression of MMP-2
and MT1-MMP using in situ hybridization and immunohistochemistry in 102 cases of
transitional cell carcinoma of the upper urinary tract (TCC-UUT). A positive
expression of each metalloproteinase was recognized in all samples and was
apparent within the cytoplasm of tumor epithelial cells and/or stromal cells
situated at the interface between tumor and stroma. Our analysis of
clinicopathologic findings showed a relationship between MMP-2 and MT1-MMP
expression and stage. The correlation between the MMP-2 protein staining score
for tumor epithelial cells and overall survival rate reached significance in the
univariate analysis. However, only stage was associated with disease-free and
overall survivals in the multivariate analysis. In conclusion, the detection of
MMP-2 and MT1-MMP would appear to be of limited value in informing the prognosis
of TCC-UUT.
PMID- 10685634
TI - Histopathologic analysis of chromosome aneuploidy in ductal carcinoma in situ.
AB - Formalin-fixed, paraffin-embedded sections from 28 cases of ductal carcinoma in
situ (DCIS; 12 with coexisting invasive neoplasm) were analyzed for numerical
alterations of chromosomes 7, 8, 16, and 17 by performing fluorescence in situ
hybridization (FISH) using centromeric (alpha-satellite) probes. Based on signal
counts in 200 to 300 nuclei, each hybridization was classified as disomic (copy
loss in <40%, copy gain in < 10%), monosomic (copy loss in at least 50% of
nuclei, partial if 40% to 49%) or trisomic/polysomic (copy gain in at least 20%
of nuclei, partial if 10% to 19%). Grade I lesions were characterized by complete
lack of significant chromosome gain, but 29% showed partial (focal) monosomy.
Grade III lesions, in contrast, showed partial or complete trisomy/polysomy in
88% of hybridizations versus monosomy in only 4%. Grade II DCIS exhibited a mixed
pattern of chromosome aneuploidy: 38% hybridizations were disomic, 36%
trisomic/polysomic, and 26% monosomic (8 of 10 hybridizations showing complete
monosomy occurred in grade II lesions). Disomic hybridizations exhibiting rare
cells (5% to 10%) with copy gain were more frequent in tumors with coexisting
invasive neoplasm (5 of 17 v 2 of 33, P = .02). In morphologically heterogeneous
lesions, higher-grade foci were characterized by chromosome copy gain relative to
corresponding lower-grade areas in 17 of 22 (77%) hybridizations. These results
show the presence of multiple (at least 3) distinct chromosome aneuploidy
patterns in DCIS, in keeping with divergent mechanisms of genetic alteration.
Degree of chromosomal instability, moreover, may correlate with progression of
DCIS to invasive growth, implying that genetic instability is a parameter that
impacts the likelihood of early breast carcinoma progression.
PMID- 10685635
TI - Sarcomatoid salivary duct carcinoma of the parotid gland.
AB - Salivary duct carcinoma (SDC) is a high-grade neoplasm known to histologically
resemble high-grade ductal carcinoma in situ of the breast. We describe 3 cases
of sarcomatoid salivary duct carcinoma, a heretofore unreported variant of SDC.
Each case was a composite of SDC and sarcomatoid carcinoma and histologically
similar to reported cases arising in the breast. The clinicopathologic features,
including immunohistochemistry, of 3 cases were investigated. In the 3 men, ages
56, 68, and 70 years, the resected parotid tumors measured 1.5, 3.5, and 1.5 cm,
respectively. Only the 3.5-cm tumor extended beyond the parotid gland into soft
tissue. This patient died at 3 years with pulmonary metastases. The other
patients were free of disease at 6 and 12 months. Histologically, each case was a
composite of usual-type SDC and sarcomatoid carcinoma. SDC showed typical
cribriform architecture, whereas anaplastic, spindled cells constituted the
sarcomatoid areas. Immunohistochemically, epithelial elements stained as follows:
cytokeratin (AE1/AE3 & CAM 5.2) positive in 3 of 3 cases, EMA positive in 3 of 3
cases, vimentin negative in 3 of 3 cases, desmin negative in 3 of 3 cases, c-erbB
2 positive in 1 of 2 cases. Sarcomatoid elements stained as follows: AE1/AE3
negative in 3 of 3 cases, CAM 5.2 rare positive cell in 1 of 3 cases, EMA focally
positive in 3 of 3 cases, vimentin positive in 3 of 3 cases, desmin negative in 3
of 3 cases, c-erbB-2 negative in 2 of 2 cases. Electron microscopy, performed in
one case, showed scattered junctional complexes congruent with epithelial
differentiation. Immunohistochemical results, EMA and CAM 5.2 positivity, and
ultrastructural findings supported our belief that these unique biphasic tumors
represented SDC with sarcomatoid carcinoma. We conclude an element of sarcomatoid
carcinoma rarely may arise in association with SDC, and it is erroneous to
diagnose such tumors as "carcinosarcoma."
PMID- 10685636
TI - Expression of DNA topoisomerase I in neoplasms of the kidney: correlation with
histological grade, proliferation, and patient survival.
AB - Renal cell carcinoma is an inherently chemotherapeutically resistant neoplasm.
Because of this, new drugs targeting this tumor are needed. One class of new
anticancer drug targets the enzyme DNA topoisomerase I. Laboratory data indicate
that cells sensitive to topo I targeting drugs contain high topo I levels. To
determine whether some renal cell carcinomas contain elevated topo I and might
therefore be targets of topo I active antitumor agents, we used a new
immunohistochemical stain for topo I to determine the expression of the enzyme in
51 tumors of the kidney. Increased topo I expression was found in 4 of 11 (36%)
grade 3 renal cell carcinomas and in 8 of 8 (100%) grade 4 renal cell carcinomas.
Normal topo I expression was observed in all adenomas, oncocytomas, and grade 1
and grade 2 renal cell carcinomas. Because topo I targeted anticancer drugs are S
phase specific, topo II-alpha and MIB-1 proliferation indices also were
performed. Topo II-alpha correlates well with MIB-1 (correlation coefficient =
0.96). Of the 12 tumors with elevated topo I, only 3 had topo II-alpha
proliferation indices greater than 40, indicating a tumor with elevated topo I
expression and a large growth fraction. We hypothesize that these tumors might be
susceptible to topo I anticancer drug therapy. In addition, we found that the
average topo II-alpha proliferation index of tumors from patients who died of
disease was 27.4 +/- 19.8, which was statistically different from the average
topo II-alpha index of 5.8 +/- 6.5 observed in tumors from patients who remained
alive during our follow-up.
PMID- 10685637
TI - Lack of CD 29 (beta1 integrin) and CD 54 (ICAM-1) adhesion molecules in
intravascular lymphomatosis.
AB - Intravascular Lymphomatosis (IL) is a rare and usually aggressive form of non
Hodgkin's lymphoma characterized by the growth of neoplastic cells within
vascular lumina that usually presents with skin or central nervous system (CNS)
involvement. The mechanism(s) for the selective intravascular growth of this
neoplasm remain(s) unexplained. We now report clinical and immunohistologic data
on surgical material from 6 cases of IL; in 4 of 6 cases, autopsies were
performed. Our IL cases shared the following features: (1) B-cell lineage; (2)
lack of skin involvement at presentation; (3) aggressive behavior; and (4) lack
of extravascular lymphomatous masses; in addition, 1 case had an associated
gastric low-grade MALT lymphoma. We studied by immunohistochemistry formalin
fixed, paraffin-embedded sections with monoclonal antibodies to molecules known
to be involved in lymphocyte and endothelial adhesion phenomena, that is, CD29
(beta1 integrin subunit), CD43 (leukosialin), CD44 (H-CAM), CD54 (ICAM-1),
embryonal N-CAM (e-NCAM), and EMA (episialin). In all cases, the surfaces of IL
aggregates reacted for CD44 but were consistently negative for CD29; also absent
was CD54. Conversely, the integrity of the endothelial cells was underscored by
their even reactivity for CD29, CD44, and CD54. Given that CD29 is currently
regarded as critical for lymphocyte trafficking in general and for transvascular
migration in particular, and CD54 is also involved in transvascular lymphocyte
migration, we conclude that their consistent absence in IL may contribute to its
intravascular and disseminated distribution pattern. The rather frequent
association of IL with various conventional lymphomas is known; yet, one of our
cases appears to be the first report of IL associated with a low-grade MALT
lymphoma.
PMID- 10685638
TI - Second primary epithelial malignancy of nasopharynx and nasal cavity after
successful curative radiation therapy of nasopharyngeal carcinoma.
AB - Patients with head and neck cancer are at high risk of developing additional
second primary tumors in the aerodigestive tract as a result of the field
cancerization phenomenon. In this context, the appearance of a new neoplasm often
poses a problem in differential diagnosis between recurrence and new primary
tumor. Twelve patients with nasopharyngeal carcinoma (NPC) who received radiation
therapy for the primary tumor and developed a second epithelial malignancy in the
nasal cavity or nasopharynx during the follow-up period are presented in this
report. The differentiation between the 2 entities based on the spatiotemporal
relations, histological features, and the status of Epstein-Barr virus in tumor
lesions are also presented. Our study showed that the epithelial malignancy after
NPC having late-onset or prolonged interval (range, 5 to 18 years), different
histological patterns (keratinizing squamous cell carcinoma, neuroendocrine
carcinoma, or small cell carcinoma) distinct from the primary NPC (differentiated
or undifferentiated nonkeratinizing carcinoma), and absence of Epstein-Barr
virus, indicate a newly developed tumor rather than recurrent NPC. Our
observations showed for the first time that second primary epithelial malignancy
developed in the nasal cavity or nasopharynx years after curative therapy for NPC
with a prevalence of 0.4% (12/2,794). Wild-type p53 protein was expressed more
often in the original NPC (9 of 12) than in the second tumors (4 of 10), but the
significance was not statistically significant (P = .2048). Genomic analysis for
p53 mutation and in situ hybridization for human papillomavirus showed negative
results, indicating that both important molecular events in NPC or head and neck
cancer play a small role in this particular type of newly developed second
malignant tumor. More studies are warranted for further clarification for the
development of second epithelial malignancies in treated NPC patients.
PMID- 10685639
TI - Loss of heterozygosity in P53, BRCA1, and estrogen receptor genes and correlation
to expression of p53 protein in ovarian epithelial tumors of different cell types
and biological behavior.
AB - Loss of heterozygosity (LOH) of tumor suppressor genes (TSGs) in ovarian
epithelial tumors of differing cell types and biological behavior has not been
thoroughly investigated. Moreover, there have been conflicting reports
correlating LOH of the p53 gene to overexpression of p53 protein. This study
evaluated 34 formalin-fixed, paraffin-embedded ovarian epithelial tumors for LOH
by polymerase chain reaction (PCR) for the following microsatellite markers:
TP53(17p13.1/p53 gene), D17S579(17q/BRCA1 gene), and ESR (6q24-27/estrogen
receptor gene). LOH of the TP53 marker was detected in 4 (44%) of 9 informative
serous cystadenocarcinomas (SCa) but in 0 of 4 informative clear cell carcinomas
(CCa) and 0 of 5 informative serous tumors of low malignant potential (SLMP). LOH
of the BRCA1 marker was detected in 5 (83%) of 6 informative SCa, but in 1 (13%)
of 8 informative CCa and 1 (14%) of 7 informative SLMP. LOH of the ESR marker was
detected in 4 (50%) of 8 informative SCa, but in 0 of 4 informative CCa and 1
(16%) of 6 informative SLMP. p53 protein overexpression was present in 8 of 12
SCa but did not correlate to TP53 LOH. LOH for TP53, D17S579/ BRCA1, and ESR is
common in ovarian SCa, and is observed in primary tumors as well as metastases.
In contrast, these genetic alterations are less common in CCa and in the
biologically less aggressive SLMP tumors. These data suggest different mechanisms
of oncogenesis in ovarian epithelial tumors of different cell types and
biological behavior.
PMID- 10685640
TI - Reactive vascular lesion of nasal septum simulating angiosarcoma in a cocaine
abuser.
AB - We report the case of an exuberant ulcerative angiomatoid nasal lesion in a
cocaine abuser. The lesion was made up of polymorphous endothelial cells with
occasional mitoses, arranged in a lobular pattern with infiltrative-looking
areas. There were extensive areas of thrombosis with focal recanalization.
Intravascular proliferation was not observed. The clinical, radiological, and
histological features suggested hemangiosarcoma as the main differential
diagnosis, but the lobular architecture of the lesion and the widespread
thrombosis favoured the diagnosis of a benign reactive process.
PMID- 10685641
TI - The ciliated hepatic foregut cyst, an unusual bronchiolar foregut malformation: a
histological, histochemical, and immunohistochemical study of 7 cases.
AB - The ciliated hepatic foregut cyst is an unusual solitary cystic lesion of the
liver. In a series of 7 cases of hepatic ciliated cysts, we performed a
histological, histochemical, and immunohistochemical study to better define the
histogenesis of this rare entity. The patients were 4 women and 3 men, aged 39 to
75 years. Four patients presented with abdominal pain. In 3 cases the cyst was
discovered incidentally on ultrasonography. The cysts measured from 1 to 4 cm in
diameter. Microscopically, the lining of the columnar epithelium was composed of
ciliated cells and mucin secreting goblet cells. The wall was composed of bands
of smooth-muscle fibers surrounded by an outer fibrous capsule. The goblet cells
stained with PAS, alcian blue, and high-iron diamine. The immunohistochemical
study showed that endocrine cells were present within the cyst epithelium,
positive for chromogranin, synaptophysin, bombesin, and calcitonin, and negative
for serotonin, somatostatin, glucagon, insulin, gastrin, and pancreatic
polypeptide. In all the cases, immunoreactivity of some cells for CC10 strongly
suggested the presence of Clara cells. Our study shows that the epithelium lining
ciliated hepatic foregut cysts has histological, histochemical, and
immunohistochemical features similar to those observed in the bronchiolar
epithelium. This lesion is a developmental ventral foregut abnormality that could
arise from a bronchiolar bud of the tracheobronchial diverticulum.
PMID- 10685642
TI - Molecularly confirmed primary prostatic synovial sarcoma.
AB - We report the second molecularly-confirmed primary prostatic synovial sarcoma.
The diagnosis was particularly elusive at the light microscopic level in that the
tumor failed to show epithelial differentiation, but it did show combined spindle
cell and poorly differentiated (round-cell) morphologies. The immunohistochemical
staining profile was nonspecific and potentially misleading. Only by
demonstration of the characteristic SYT-SSX gene fusion of synovial sarcoma by
reverse transcriptase polymerase chain reaction (RT-PCR) analysis of RNA
extracted from archival material could the diagnosis be confirmed. This case
further illustrates the use of this technique in diagnostic pathology.
PMID- 10685643
TI - Subacute hepatic failure associated with a new antidiabetic agent, troglitazone:
a case report with autopsy examination.
AB - An autopsy case of fatal subacute hepatic failure after administration of
troglitazone is described. The liver dysfunction developed about five months
after the patient, a sixty-three-year-old woman, had been initially treated with
troglitazone. The patient developed hepatic failure and died despite various
hepatic auxiliary treatments such as plasmapheresis. Autopsy findings revealed
focal liver cell necrosis, cholestasis and steatosis with infiltration of
lymphocytes and neutrophils and lack of regenerative activity. The causative
mechanism of liver dysfunction may be metabolite aberration, as a result of
accumulation of hepatotoxic metabolite(s), in a category of idiosyncratic liver
injury. It is proposed to monitor liver function strictly and periodically for
the diabetic patients prescribed troglitazone.
PMID- 10685644
TI - Epstein-Barr virus-associated Hodgkin's lymphoma and legionella pneumophila
infection complicating treatment of juvenile rheumatoid arthritis with
methotrexate and cyclosporine A.
AB - We describe the case of a 53-month-old girl with juvenile rheumatoid arthritis
(JRA), complicated by the occurrence of Hodgkin's lymphoma and Legionella
pneumophila infection during immunosuppressive treatment with methotrexate (MTX)
and cyclosporine A (CSA). The girl had received variable anti-inflammatory
combination therapy, including MTX for 28 months and CSA for 3 months. Thirty-six
months after the onset of arthritis, the girl presented with an enlargement of
the lymph nodes of the mediastinum, the hilum of the lungs, and the abdomen.
Concomitantly, a diagnosis of Legionella pneumonia was rendered. Autopsy showed
Epstein-Barr virus (EBV)-associated nodular sclerosing Hodgkin's lymphoma. The
neoplastic cells were positive for CD15, CD 30, and latent membrane protein 1
(LMP 1). The present case is the second reported to occur in a child, and it
lends support to the hypothesis that immunosuppressive treatment may contribute
to an increased risk of the development of EBV-associated lymphoproliferative
disorders (LPD) in pediatric patients suffering from JRA.
PMID- 10685645
TI - Low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of thymus.
AB - This report describes a low-grade B-cell lymphoma of mucosa associated lymphoid
tissue (MALT) involving the thymus of a 63-year-old woman with features
suggestive of a connective tissue disease. Sections of the thymic lesion and of a
lung biopsy performed at the same operation were examined histologically and by
immunohistochemistry using the monoclonal antibodies CD45, CD20, CD79a, CD3,
CD45RO, and AE1/AE3. Polymerase chain reaction (PCR) for immunoglobulin heavy
chain gene rearrangement was also performed. The dense infiltrate of small
lymphoid cells intimately admixed with ramifying epithelial elements, some of
which had undergone cystic change, closely resembled a thymoma. The lymphoid
infiltrate comprised centrocyte-like cells, small lymphocytes, plasma cells, and
blasts. Most of the lymphoid cells were immunoreactive with the B-cell markers
CD20 and CD79a, and PCR showed clonal immunoglobulin heavy chain gene
rearrangement. The lung biopsy showed dense infiltration by small lymphoid cells,
morphologically suggestive of lymphoid interstitial pneumonia. However, PCR
showed a weak band in the amplification for immunoglobulin heavy chain gene
rearrangement, identical to that within the thymus and suggesting either
recirculation of cells to accumulated MALT or subhistological lymphoma. MALT
lymphoma may rarely involve the thymus, and pathologists should be aware of this
to avoid misdiagnosis as a thymoma. Immunohistochemical and/or molecular studies
are of value in this regard. MALT lymphomas of the thymus, common with those
arising in other organs, may develop in the setting of a connective tissue
disease.
PMID- 10685646
TI - Congenital primitive epithelial tumor of the liver showing focal rhabdoid
features, placental involvement, and clinical features mimicking multifocal
hemangioma or stage 4S neuroblastoma.
AB - We describe an unusual case of congenital primitive epithelial tumor of the liver
with focal rhabdoid features. The present case is unique and informative in the
following aspects: (1) a first case of congenital epithelial tumor of the liver
with no hepatocytic differentiation but focal rhabdoid features, (2) clinical
similarities to multicentric hemangioma or stage 4S neuroblastoma, (3) diagnosis
obtained from histological examination of the placenta immediately after birth.
PMID- 10685647
TI - Eradication of Borrelia burgdorferi infection in primary marginal zone B-cell
lymphoma of the skin.
AB - Primary cutaneous B-cell lymphomas have been associated with Borrelia
burgdorferi, the spirochete responsible for Lyme disease. Recently, cutaneous
marginal zone B-cell lymphoma has been proposed as a distinct clinical
pathological entity. We report a case of primary cutaneous marginal zone
lymphoma, associated with B burgdorferi infection. Polymerase chain reaction
(PCR) amplification of the third complementarity determining region (CDR3) of the
immunoglobulin heavy chain gene showed the presence of a monoclonal
lymphoproliferation, therefore strengthening the histological diagnosis of a
malignant process. B burgdorfer-specific hbb gene sequences were detected by PCR
in the lymphoma tissue at diagnosis but not after antibiotic treatment. A nearly
complete clinical and histological regression was observed after B burgdorferi
eradication, with immunohistochemistry studies showing disappearance of plasma
cell differentiation and a marked decline in the number of CD3+ T cells and Ki
67+ cells. Our case confirms the link between B burgdorferi and some cutaneous
lymphomas. The disappearance of the microorganism accompanied by the unequivocal
decrease of most indicators of active T- and B-cell immune response strongly
supported a pathogenetic role for B burgdorferi in sustaining an antigen-driven
development and growth of this cutaneous marginal zone lymphoma. Antibiotic
therapy (analogous to Helicobacter pylori infection in gastric MALT lymphoma)
might be helpful with the aim of averting or at least deferring the indication
for more aggressive treatment.
PMID- 10685648
TI - Molecular evidence of field cancerization in a patient with 7 tumors of the
aerodigestive tract.
AB - Exposure of the mucosa of the upper aerodigestive tract to carcinogens can induce
genetic changes resulting in various independent clones of neoplastic growth, a
concept defined as "field cancerization." The risk of developing multiple tumors
in this compartment of the body is well established. We studied 6 distinct tumors
of the upper aerodigestive tract of a single patient for loss of heterozygosity
(LOH), microsatellite instability (MSI), p53 mutations, and K-ras codon 12 point
mutations. We detected a unique pattern of LOH and p53 mutations in all 6 tumors.
No tumor showed a K-ras mutation or MSI. The results support the mechanism of
"field cancerization" and illustrate the potential power of molecular techniques
to elucidate pathogenesis.
PMID- 10685649
TI - Primary signet-ring cell carcinomas of the lung.
PMID- 10685650
TI - Interleukin-2 and the development of immunotherapy for the treatment of patients
with cancer.
PMID- 10685651
TI - Interleukin-2 in metastatic melanoma: what is the current role?
PMID- 10685652
TI - High-dose recombinant interleukin-2 therapy in patients with metastatic melanoma:
long-term survival update.
AB - PURPOSE: To update response duration and survival data for patients with
metastatic melanoma receiving the high-dose IV bolus recombinant interleukin (IL)
2 regimen. PATIENTS AND METHODS: Two hundred seventy assessable patients were
entered into eight clinical trials conducted between 1985 and 1993. IL-2 600,000
or 720,000 IU/kg was administered by 15-minute intravenous infusion every 8 hours
for up to 14 consecutive doses over 5 days as clinically tolerated with maximum
support, including pressors. A second, identical cycle of treatment was scheduled
following 6 to 9 days of rest, and courses could be repeated every 6 to 12 weeks
in stable or responding patients. Responding patients received up to five courses
(two cycles/course) of treatment. All data were updated through December 1998
using report forms completed by the clinical investigators. RESULTS: The
objective overall response rate was unchanged from the previous report. Tumor
responses were seen in 16% of patients, with complete responses in 17 (6%) and
partial responses in 26 (10%). Median survival for the group as a whole is now 12
months. Median follow-up time for surviving patients exceeds 7 years. Median
duration of response for the 43 responding patients and the 26 patients with
partial responses remained unchanged at 8.9 and 5.9 months, respectively.
Response durations ranged from 1.5 to > 122 months. The median duration of
complete responses has yet to be reached, but is at least 59 months. Thirty-one
patients (11%) were alive as of last contact; 28 were confirmed, including 18
responding patients. Three patients were lost to follow-up at > 1, > 13, and >
104 months. Twelve responding patients remained continually disease- or
progression-free from > 70 to > 150 months following initiation of therapy.
Disease progression was not observed in any patient who was responding as of the
last report or in any patient responding for longer than 30 months. CONCLUSION:
These data continue to support the notion that high-dose IL-2 produces durable
responses in some patients with metastatic melanoma and should be considered a
therapeutic option for appropriately selected patients with this disease.
PMID- 10685653
TI - Rationale for intergroup trial E-3695 comparing concurrent biochemotherapy with
cisplatin, vinblastine, and DTIC alone in patients with metastatic melanoma.
AB - PURPOSE: The modest activity of chemotherapy and biologic agents in the treatment
of advanced metastatic melanoma has prompted investigators to consider
combinations of chemotherapy and biologic agents (i.e., biochemotherapy) as a way
of improving response rates and survival. Although biochemotherapy has generated
a great deal of interest over the last several years, and these regimens have
produced high response rates in single-institution phase II trials, they have yet
to demonstrate a significant survival benefit in randomized trials compared with
either chemotherapy or biotherapy alone. METHODS: The available literature
regarding the clinical experience with single- and multiagent chemotherapy,
immunotherapy, and biochemotherapy was reviewed. RESULTS: Treatment of metastatic
melanoma with either single-agent or combination chemotherapy regimens is clearly
suboptimal; the majority of responses are partial and of short duration. In
contrast, interleukin (IL)-2 produces long-term durable complete remission in a
subset of patients. Over 1,000 patients have been treated with IL-2-based
biochemotherapy regimens in single-institution phase II trials, and response
rates have ranged from 40% to 60%. Most encouraging have been the durable
responses observed in 10% to 20% of patients in most of these trials. Large
databases, including two meta-analyses, have confirmed the substantial
improvement in response rate associated with biochemotherapy regimens that
include both IL-2 and interferon alfa (IFN-alpha) compared with chemotherapy or
biotherapy alone. Biochemotherapy is currently being evaluated in randomized
controlled trials to determine if this treatment strategy can provide a survival
benefit compared with current standard treatments. A pilot study at Beth Israel
Deaconess Medical Center has demonstrated the feasibility of administering a
modification of a concurrent biochemotherapy regimen, initially described by
Legha et al, consisting of cisplatin, vinblastine, and dacarbazine (CVD) plus IL
2 and IFN-alpha in the cooperative group setting. CONCLUSION: These studies
provided the rationale for intergroup trial E-3695, which is currently
randomizing patients to concurrent biochemotherapy with CVD plus IL-2 and IFN
alpha versus CVD alone.
PMID- 10685654
TI - Strategies to reduce side effects of interleukin-2: evaluation of the
antihypotensive agent NG-monomethyl-L-arginine.
AB - PURPOSE: The clinical utility of high-dose intravenous recombinant interleukin
(IL)-2 therapy is limited by severe toxicity including hypotension, fever,
chills, pulmonary edema, and oliguria Hypotension has been previously shown to
result from excessive vascular relaxation due to overproduction of the endogenous
vasodilator nitric oxide. Nitric oxide production can be decreased by
administration of the competitive enzyme inhibitor NG-monomethyl-L-arginine
(NMA). A clinical trial to investigate the dose-dependent effects of NMA on blood
pressure was undertaken in patients with metastatic renal cell carcinoma.
PATIENTS AND METHODS: Patients with metastatic renal cell carcinoma receiving a 5
day continuous infusion of IL-2 (18 million IU/m2/d) who developed hypotension
were treated with increasing doses of NMA, ranging from 3 to 36 mg/kg. RESULTS:
Twenty-three patients received a total of 61 courses of IL-2; 18 of these
patients developed hypotension and received NMA. Antihypotensive activity was
observed at all dose levels, and the duration of the effect varied directly with
the dose of NMA. At the higher dose levels tested (12 to 36 mg/kg), increased
pulmonary vascular resistance and decreased cardiac output were observed.
Patients experiencing a significant decrease in cardiac output received
dobutamine (2.5 to 10 microg/kg/min). Pulmonary capillary wedge pressure was
unaffected by administration of NMA. One patient treated at 24 mg/kg (bolus)
experienced a major motor seizure, but no neurologic disorders were observed in
other patients treated with NMA doses of 24 to 36 mg/kg. No other adverse events
involving hepatic, renal, or hematologic systems were attributed to NMA. Three
patients received NMA by an initial bolus followed by a continuous infusion.
Similar antihypotensive effects were noted, and these patients were able to
complete a full 5-day course of IL-2. CONCLUSION: The antihypotensive effects of
NMA appear to be optimal at a dose of 24 mg/kg, with maintenance doses of 8 mg/kg
every 4 to 6 hours. At this dose level, blood pressure was restored, and IL-2
associated vasodilatation was fully reversed. Coincident with the reversal of
hypotension, the state of high cardiac output was also reversed by NMA
administration. These results suggest that NMA may be effective for alleviating
the hypotensive effects of high-dose IL-2 therapy in cancer patients.
PMID- 10685655
TI - Interleukin-2 in the treatment of hematologic malignancies.
PMID- 10685656
TI - Immunotherapy with interleukin-2 after hematopoietic cell transplantation for
hematologic malignancy.
AB - PURPOSE: The results of trials using interleukin (IL)-2-based therapy in leukemia
and after hematopoietic stem cell transplant suggest that such therapy could have
an impact on preventing disease relapse in patients with hematologic malignancy
who achieve a minimal disease state. The use of immunotherapy in the autologous
transplant setting is modeled in part on the well-characterized immunotherapeutic
effect of the graft-versus-tumor response in patients undergoing allogeneic
transplantation. The graft-versus-tumor response, mediated by donor cells,
contributes to the higher cure rates seen in patients undergoing allogeneic
transplant for the treatment of a variety of hematologic malignancies, including
acute and chronic myelogenous and lymphoblastic leukemia, myeloma, and lymphoma
PATIENTS AND METHODS: The literature was reviewed, and we relate our own clinical
experience with IL-2 therapy in this setting. RESULTS: Preclinical in vitro and
animal data show a variety of leukemia cells are sensitive to autologous IL-2
activated effector cells. In addition, laboratory studies show that IL-2 can be
used to activate antitumor cellular responses from bone marrow and peripheral
blood without compromising hematopoiesis. Most importantly, in vitro studies show
that chemoresistant malignant hematopoietic cells are sensitive to IL-2-induced
cell death, thus emphasizing the lack of cross resistance to immunologic-based
therapeutics. The results of phase I and II studies conducted in patients with
acute myelogenous leukemia in first or subsequent remission suggest that
autologous IL-2-activated cells may mediate an antitumor response and aid in
preventing relapse after autologous transplantation. Clinical trials to determine
the role of IL-2 after transplantation for the treatment of acute and chronic
myelogenous leukemia, multiple myeloma, and lymphoma are ongoing. CONCLUSION:
These studies will help define the optimal dose and schedule of IL-2 and its role
in augmenting therapeutic immune-mediated autologous responses.
PMID- 10685657
TI - Children's cancer group trials of interleukin-2 therapy to prevent relapse of
acute myelogenous leukemia.
AB - PURPOSE: Up to 80% of children with acute myelogenous leukemia treated with
intensive chemotherapy achieve remission; however, a large proportion of patients
develops recurrent disease. Because interleukin (IL)-2 can induce remission in
patients with overt evidence of acute myelogenous leukemia, we hypothesized that
it might prevent relapse when administered to patients in first remission after
intensive consolidation chemotherapy. A pilot Children's Cancer Group (CCG) trial
(CCG-0941) demonstrated the feasibility of this approach, and we initiated a
prospective randomized trial (CCG-2961) to further evaluate the safety and
potential efficacy of IL-2 therapy in preventing relapse of acute myelogenous
leukemia. PATIENTS AND METHODS: In trial CCG-0941, 21 pediatric patients in
complete remission following induction and consolidation chemotherapy on protocol
CCG-2941 received IL-2 therapy. In CCG-2961, 79 patients in complete remission
were randomized as of February 1999 to receive either IL-2 (n = 39) or no further
therapy. In both trials, recombinant IL-2 was given at a dose of 9 million
IU/m2/d by continuous intravenous infusion for 4 days. After 4 days of rest, IL-2
was resumed at a dose of 1.6 million IU/m2/d for 10 days by continuous infusion.
We monitored patients for toxicity and relapse. RESULTS: The majority of patients
treated with IL-2 in these two trials experienced some degree of fever. Seven of
60 patients (12%) had clinically significant rashes, and grade 3 vascular leak
syndrome and hypotension have each been observed in five patients (8%).
Hypotension resolved promptly after treatment with intravenous fluids. No
patients have experienced renal toxicity or required cardiac vasopressors or
transfer to an intensive care unit; there have been no treatment-related deaths.
Overall, the incidence and severity of adverse events remain similar in the two
trials. Total projected accrual to the IL-2 randomization is anticipated to be
326 patients, and relapse and survival data remain blinded. CONCLUSION: The dose
and schedule of IL-2 used in these two trials continue to be reasonably well
tolerated by children with acute myelogenous leukemia in first remission. Any
conclusions with regard to efficacy must await completion of the randomized
trial.
PMID- 10685658
TI - Cytokine replacement in patients with HIV-1 non-Hodgkin's lymphoma: the rationale
for low-dose interleukin-2 therapy.
AB - PURPOSE: The drastic increase in the incidence of non-Hodgkin's lymphoma in
patients infected with HIV-1 is testimony to the fact that our immune system is
critical for the prevention of certain malignancies. Preclinical and clinical
studies were conducted to (1) gain further insight into defects in immunity that
can lead to malignant transformation and (2) determine if certain immune
deficiencies could be corrected by cytokines delivered at doses that result in
near-physiologic concentrations in vivo. METHODS: We have used the severe
combined immune deficient mouse engrafted with human peripheral blood leukocytes
from healthy individuals who are seropositive for the Epstein-Barr virus to study
the spontaneous development of malignant Epstein-Barr virus-positive human B-cell
lymphoproliferative disorder. RESULTS: We have demonstrated in this model that,
in the absence of CD4+ T cells, cytokine replacement with low-dose interleukin
(IL)-2 therapy can prevent Epstein-Barr virus-positive human B-cell
lymphoproliferative disorder by interacting with mouse natural killer and human
CD8+ T cells. We review our clinical experience with administration of low-dose
IL-2 therapy in patients with HIV-1-related cancer, noting minimal toxicity and
significant immune modulation. We provide evidence that this therapy can
favorably alter the type 1 cytokine profile in vivo in these patients, and
improve the cellular response to infectious insults in vitro. CONCLUSION: Early
clinical studies with low-dose IL-2 therapy in patients with HIV-1-related
lymphoma suggest that this therapy may have a role in the prevention and
treatment of this disease.
PMID- 10685659
TI - Renal cell carcinoma: current status and future plans.
PMID- 10685660
TI - Long-term survival update for high-dose recombinant interleukin-2 in patients
with renal cell carcinoma.
AB - PURPOSE: To update response duration and survival data for patients with
metastatic renal cell carcinoma treated with high-dose interleukin (IL)-2.
PATIENTS AND METHODS: Two hundred fifty-five assessable patients were entered
onto seven phase II clinical trials. Recombinant IL-2 600,000 or 720,000 IU/kg
was administered by 15-minute intravenous infusion every 8 hours for up to 14
consecutive doses over 5 days as clinically tolerated with maximal support. A
second, identical cycle of treatment was scheduled following 5 to 9 days of rest,
and courses could be repeated every 6 to 12 weeks in stable or responding
patients. All data were updated as of December 1998, with report forms completed
by the clinical investigators. These data had last been updated as part of the
Food and Drug Administration reporting requirements in 1996. RESULTS: Objective
responses previously have been reported in 37 of 255 patients (15%) with 17
complete responses (7%) and 20 partial responses (8%). These data remain
unchanged from previous reports. Median response duration for all objective
responders remains unchanged at 54 months, but the range now extends from 3 to >
131 months. Median duration for all complete responses has not yet been reached,
but was at least 80 months (range, 7- > 131 mo) at the time of this analysis.
Median duration for all partial responses remains 20 months (range, 3- > 126 mo).
Median survival time for all 255 patients remains 16.3 months, with 10% to 20% of
patients estimated to be alive 5 to 10 years after treatment with high-dose IL-2.
CONCLUSION: With prolonged follow-up, treatment with high-dose recombinant IL-2
remains extremely effective for a subset of patients with metastatic renal cell
carcinoma.
PMID- 10685661
TI - The future role of interleukin-2 in cancer therapy.
PMID- 10685662
TI - Interleukin-2: developing additional cytokine gene therapies using fibroblasts or
dendritic cells to enhance tumor immunity.
AB - PURPOSE: Recombinant interleukin (IL)-2 administration can mediate regression of
solid tumors in patients with melanoma and renal cell carcinoma. A better
understanding of the mechanisms of IL-2-mediated antitumor effects has led to the
investigation of novel immunotherapeutic approaches. The rationale for these
immunotherapeutic approaches and the results of preliminary clinical studies are
presented. PATIENTS AND METHODS: The therapeutic potential of dendritic cells and
the role of FLT3 ligand, a potent hematopoietic growth factor, was investigated
in a variety of preclinical models. In addition, a clinical study with autologous
dendritic cells pulsed with synthetic melanoma peptides derived from the MART1/
Melan A, gp100, and tyrosinase proteins was conducted. Twenty-eight human
leukocyte antigen (HLA)-A2+ melanoma patients received an average of 106
dendritic cells a week for 4 weeks. RESULTS: In a murine liver metastases model,
FLT3 ligand administration alone or in combination with IL-12 or IL-2 had
significant antitumor effects and resulted in significant infiltration of the
tumor border by lymphocytes and dendritic cells, which was associated with an
increased number of apoptotic figures. Administration of melanoma peptide-pulsed
dendritic cells to 28 patients with advanced metastatic melanoma produced a
complete response in two patients and a partial response in one. Significant
infiltration of T cells and dendritic cells into melanoma lesions was observed.
CONCLUSION: These studies confirm the feasibility of immunotherapeutic approaches
using dendritic cells and FLT3 ligand and demonstrate their potential antitumor
activity. These approaches may be effective for patients with metastatic melanoma
and other solid tumors and will likely be used to improve the efficacy of IL-2
based immunotherapy.
PMID- 10685663
TI - Potentiation of immunologic responsiveness to dendritic cell-based tumor vaccines
by recombinant interleukin-2.
AB - PURPOSE: Dendritic cells (DC) can elicit potent immune responses to tumors
through their capacity to efficiently process and present tumor-associated
antigens. In a variety of animal tumor models, vaccines based on tumor lysate
pulsed DC (TP-DC) have been shown to effectively immunize against lethal tumor
challenges as well as to treat established growing tumors at skin and organ
sites. The antitumor effects elicited by TP-DC-based vaccines in vivo have been
shown to be mediated by tumor-specific proliferative, cytotoxic, and cytokine
secreting host-derived T cells. Because of the critical involvement of T cells in
the antitumor immune response, we have been investigating whether the systemic
administration of recombinant interleukin (IL)-2 can enhance the therapeutic
efficacy of TP-DC-based tumor vaccines. MATERIALS AND METHODS: Immunization with
TP-DC plus IL-2 administration was evaluated to determine if this combination
could enhance protective immunity toward a weakly immunogenic sarcoma (MCA-207)
and a poorly immunogenic subline (D5) of the B16 melanoma and mediate therapeutic
rejection of established tumors in C57BL/6 (B6) mouse models. RESULTS: We have
demonstrated in our murine models that the addition of IL-2 at relatively
nontoxic doses can markedly augment the antitumor activity of TP-DC-based tumor
vaccine therapies against both a weakly immunogenic sarcoma and a poorly
immunogenic melanoma. Animals treated with the combination exhibited
significantly greater protection from tumor-cell challenge, significantly greater
regression of established tumors, and significantly longer mean survival time
than with either TP-DC or IL-2 therapy alone. The mechanism operative in vivo
appears to involve the enhancement of immune T-cell function. CONCLUSION: These
preclinical studies demonstrate the potential of this novel treatment strategy
and support the rationale for planned phase I/II clinical trials of TP-DC-based
vaccines plus IL-2 in patients with advanced melanoma and colorectal cancer.
PMID- 10685664
TI - The future of interleukin-2: enhancing therapeutic anticancer vaccines.
AB - PURPOSE: The purpose of our efforts is to trigger the immune destruction of
established cancer. Interleukin (IL)-2 can mediate the regression of tumors in
patients with melanoma and renal cell carcinoma. In animal models, the antitumor
effects of IL-2 are mediated by T lymphocytes. Stimulation with specific antigen
can enhance the ability of T cells to respond to IL-2 by triggering the rapid
upregulation of the high-affinity IL-2 receptor. We are seeking to design
recombinant and synthetic vaccines capable of preferentially priming T cells with
specificity for tumor cells. METHODS: The antitumor activity of experimental
vaccines is being studied preclinically using recently developed murine models
that employ the mouse homologues of human tumor-associated antigens. Once the
most effective experimental vaccines are optimized in experimental animals,
clinical trials can be conducted. Vaccines are being evaluated for their ability
to mediate the regression of established tumors, and a variety of immunologic
correlates are being measured. RESULTS: In animal models, vaccines based on
molecularly defined tumor-associated antigens expressed in viral vectors or
delivered as "naked" DNA stimulate the expansion of CD4+ and CD8+ tumor-specific
T lymphocytes. Coadministration of IL-2 with these vaccines dramatically enhances
their ability to mediate the regression of established cancer. In the clinic,
treatment of melanoma patients with peptide vaccine and IL-2 resulted in
objective responses in approximately 40% of patients, a response rate more than
twice that typically achieved with IL-2 alone. Paradoxically, tumor-specific CD8+
T-cell levels were not increased in these patients. CONCLUSION: The addition of
recombinant and synthetic cancer vaccines to a regimen of IL-2 can result in
improved antitumor responses in both animal models and melanoma patients. Vaccine
primed, tumor-specific T cells may preferentially proliferate upon administration
of IL-2. The apparent lack of increase in CD8+ T-cell numbers in this setting
suggests that the vaccine-primed T cells functionally disappear after a transient
period of activation. Preventing the disappearance of activated T cells upon IL-2
administration-for example, by blocking proapoptotic signals-may enhance the
therapeutic effectiveness of anticancer vaccines.
PMID- 10685665
TI - Tumor-induced dysfunction in interleukin-2 production and interleukin-2 receptor
signaling: a mechanism of immune escape.
AB - PURPOSE: The development of an effective antitumor immune response is compromised
in patients with renal cell carcinoma. Despite significant infiltration by T
lymphocytes into renal tumors, no detectable induction of gene expression is
associated with the generation of an antitumor immune response. Tumor-induced
down-regulation of interleukin (IL)-2 expression may contribute to the impaired
development of the T cell-mediated antitumor immune response. Within renal
tumors, there is no detectable expression of IL-2 or the IL-2 receptor alpha
chain, and only low levels of interferon gamma (IFN-gamma) mRNA are detected.
Products in the tumor environment may suppress the expression of these genes,
thus inhibiting production of type 1 helper T cell cytokines. METHODS: Peripheral
blood lymphocytes obtained from healthy volunteers were exposed to supernatants
from renal cell carcinoma explants, and the immunologic consequences of this were
assessed using a variety of molecular assays. RESULTS: Soluble products from
renal tumor explants can inhibit the production of IL-2 and IFN-gamma by
peripheral blood lymphocytes and can suppress T-cell proliferation. Soluble
products from renal cell carcinoma explants appear to block the nuclear
translocation of nuclear factor kappa B (NFkappaB) proteins p50 and RelA without
affecting cytoplasmic levels of these proteins. In some experiments, a reduction
in the nuclear translocation of other transcription factors involved in IL-2 gene
expression, including nuclear factor of activated T cells and accessory protein
1, was observed. Gangliosides isolated from tumor supernatants blocked the
production of IL-2 and IFN-gamma in response to ionomycin plus phorbol myristate
acetate stimulation. These gangliosides also inhibited stimulus-dependent
activation and nuclear accumulation of NFkappaB. Coculture experiments
demonstrated that renal cell carcinoma lines known to express gangliosides could
inhibit the activation of NFkappaB in normal T cells and the Jurkat T-cell line.
Supernatants from renal cell carcinoma explants and renal cell carcinoma cell
lines can also suppress the proliferation of normal T cells, thus reproducing
another defect observed in tumor-infiltrating lymphocytes. Supernatants from
renal cell carcinoma tumors also appear to inhibit signaling through the IL-2
receptor. Although tumor supernatants had little effect on IL-2 receptor (alpha,
beta or gamma) expression, they did block expression of JAK3, a key kinase
involved in signaling through the IL-2 receptor pathway. Moreover, downstream
events in IL-2 receptor signaling linked to JAK3 were impaired in T cells treated
with tumor supernatants. CONCLUSION: These findings suggest that soluble products
from renal tumors may suppress T-cell responses by blocking both IL-2 production
and normal IL-2 receptor signaling.
PMID- 10685666
TI - Expanding the indications for surgery and adjuvant interleukin-2-based
immunotherapy in patients with advanced renal cell carcinoma.
AB - PURPOSE: To determine the role of surgery and adjuvant interleukin (IL)-2-based
immunotherapy in the treatment of patients with advanced metastatic renal cell
carcinoma PATIENTS AND METHODS: The survival of 354 consecutive patients with
metastatic renal cell carcinoma treated with IL-2-based immunotherapy through the
UCLA Medical Center Kidney Cancer Program was analyzed There were five groups of
patients. Patients who initially presented with metastatic disease received
either (1) IL-2 therapy with primary tumor in place; (2) nephrectomy followed by
IL-2 therapy, or (3) nephrectomy followed by immunotherapy with IL-2 plus tumor
infiltrating lymphocytes. Patients who underwent nephrectomy for localized
disease were divided into two groups: (4) those who developed metastatic disease
> or = 6 months after nephrectomy and then received IL-2 therapy; and (5) those
who developed metastatic disease < 6 months after nephrectomy and then received
IL-2 therapy. Kaplan-Meier survival curves were generated for all patient groups.
RESULTS: Among patients who received IL-2-based immunotherapy with their primary
tumor in place (group 1; n = 36), 1- and 2-year survival rates were 29% and 4%,
respectively, compared with 1- and 2-year survival rates of 67% and 44%,
respectively, for all similar patients who underwent nephrectomy prior to IL-2
therapy (n = 235). Among patients initially presenting with metastatic disease
who underwent nephrectomy followed by IL-2 therapy without tumor-infiltrating
lymphocytes (group 2; n = 69), the 1- and 2-year survival rates were 53% and 25%,
respectively. The best survival was observed in patients treated with nephrectomy
followed by IL-2 plus tumor-infiltrating lymphocyte therapy (group 3; n = 102),
which yielded 1- and 2-year survival rates of 73% and 55%, respectively. Among
patients initially undergoing nephrectomy for localized disease, patients
receiving IL-2-based therapy for subsequent metastasis > or = 6 months following
nephrectomy (group 4; n = 128) had 1- and 2-year survival rates of 64% and 40%,
respectively, compared with 45% and 15%, respectively, for patients developing
metastasis < 6 months after nephrectomy (group 5; n = 19). CONCLUSION: The role
of surgery prior to IL-2-based immunotherapy remains controversial Our data
demonstrate that aggressive surgery is safe, causing minimal morbidity despite
extensive tumor involvement, and significantly improves survival outcomes in
patients with metastatic renal cell carcinoma when carried out in conjunction
with an IL2-based immunotherapy regimen.
PMID- 10685667
TI - Long-term follow-up of patients with metastatic renal cell carcinoma treated with
intravenous recombinant interleukin-2 in Europe.
AB - PURPOSE: The median survival for patients with metastatic renal cell carcinoma
(mRCC) is generally < 1 year. Immunotherapy with high-dose recombinant
interleukin (IL)-2 has been reported to produce objective responses in
approximately 15% of treated patients and is associated with durable complete
responses and prolonged survival in responding patients. The impact of IL-2
therapy on survival of metastatic renal cell carcinoma patients has begun to
emerge, based on long-term follow-up data from large databases. Combinations of
IL-2 and interferon alfa (IFN-alpha) have also been intensively investigated in
mRCC. PATIENTS AND METHODS: Between 1987 and 1990, 281 mRCC patients were treated
with continuous infusion IL-2 in three European multinational, single-arm phase
II trials. Long-term treatment outcomes for these patients were analyzed, and the
results are presented here. The results of a large, randomized French cooperative
group trial (the Cancer Renal Cytokine [CRECY] study) that enrolled 425 patients
between 1991 and 1995 are also summarized. Patients on this trial were randomized
to treatment with IL-2 alone, IFN-alpha alone, or the combination. RESULTS: Among
patients included in the 281-patient database, the objective response rate was
15%. Median survival was 10 months; 41% of patients were alive at 1 year, 22%
were alive at 2 years, and 8% were alive at 5 years. Among patients with a
complete or partial response, 60% and 18% were alive at 5 years, respectively. No
clinical factors were predictive for response or survival; however, no patient
with a high endogenous IL-6 level at diagnosis responded to IL-2 therapy. The
CRECY trial demonstrated that the combination of IL-2 and IFN-alpha induced a
significantly higher response rate (P < 0.01) and significantly improved 1-year
event-free survival (P = 0.01) compared with either agent alone, but overall
survival was not significantly different between the three treatment groups.
CONCLUSION: The European experience suggests that the 5-year survival rate for
metastatic renal cell carcinoma patients treated with high-dose continuous
infusion IL-2 therapy is approximately 8% and that the majority of the
therapeutic benefit is restricted to patients achieving a complete response.
Therefore, given the toxicity, candidates for IL-2 therapy should be carefully
selected. The combination of IL-2 and IFN-alpha does not appear to provide
additional survival benefit. Efforts to further improve therapeutic outcome for
patients with metastatic renal cell carcinoma should focus on understanding the
underlying mechanisms of cytokine-induced tumor regression.
PMID- 10685668
TI - The role of interleukin-2 in the management of stage IV melanoma: the EORTC
melanoma cooperative group program.
AB - PURPOSE: To review the current information available from the European
Organization for Research and Treatment of Cancer (EORTC) programs on the use of
interleukin (IL)-2 in stage IV melanoma patients. PATIENTS AND METHODS: A
database from 631 patients treated within 27 trials with high-dose IL-2-based
regimens was compiled to develop hypotheses and valid stratification factors for
randomized trials. Subsequently, 126 patients were enrolled in a trial evaluating
interferon alfa (IFN-alpha) and IL-2 with or without cisplatin, and 325 patients
were enrolled in an ongoing EORTC trial (18951) to evaluate dacarbazine,
cisplatin, and IFN-alpha, with or without IL-2. RESULTS: The database suggests
long-term survival rates of 23% and a 5-year survival rate of 13% for patients
receiving a combination of IFN-alpha and IL-2 with or without chemotherapy. The
addition of chemotherapy improved response rate but not survival. The first
randomized trial testing the role of cisplatin in a chemoimmunotherapy regimen
for advanced melanoma revealed a palliative effect for cisplatin but no survival
benefit. The current trial (EORTC 18951), which is testing the impact of IL-2 on
survival, is still immature. In the translational research program, we have
evidence that patients in continuous complete remission after IL-2-based
treatment have evidence of residual disease by polymerase chain reaction assay
and, at the same time, melanoma-reactive T cells are present in the peripheral
blood. CONCLUSION: Mature results defining the role and, to some extent, the
mechanism of IL-2 in advanced melanoma are emerging.
PMID- 10685669
TI - Overview of interleukin-2 inhalation therapy.
AB - PURPOSE: Locoregional administration of interleukin (IL)-2, which acts
physiologically as a local hormone, is an effective therapeutic modality. Diverse
preclinical and clinical models have described methods of administration that
expose tumor tissues to continuously high levels of cytokines. Regional
administration of IL-2 that does not raise intravascular IL-2 levels induces
local and systemic immunomodulation and produces objective local tumor responses.
Most importantly, regional therapy is much less toxic than systemic IL-2 therapy.
PATIENTS AND METHODS: We review clinical experiences using inhaled IL-2 therapy
for the treatment of pulmonary metastases in roughly 300 patients with a variety
of primary tumors. This includes our own 10-year single-institution experience
with inhaled IL-2 therapy in the treatment of 188 metastatic renal cell carcinoma
patients with progressive pulmonary metastases. Patients in our clinic are
treated with 18 to 36 million IU of recombinant IL-2, administered 90% by
inhalation and 10% subcutaneously, until disease progression. A variety of doses
and schedules of inhaled IL-2 have been investigated alone and in combination
with systemic therapies. RESULTS: Inhalation of IL-2 has been reported to prevent
progression of pulmonary and mediastinal metastases of metastatic renal cell
carcinoma, breast and ovarian carcinoma, and melanoma. Inhaled IL-2 alone is well
tolerated; a dose-dependent cough is the major adverse event. A significant dose
dependent increase in lymphocytes and eosinophils has been observed in
bronchoalveolar lavage in patients and animals. Dose and schedule can influence
outcome. In a phase I trial using inhaled IL-2 alone in patients with a variety
of primary malignancies, once-daily inhalation of IL-2 at doses up to 15 million
IU/m2 was well tolerated but did not result in prolonged stabilization of
pulmonary disease. In a multidose phase I trial, using 5-times-daily inhalation
of natural IL-2, pulmonary lesions in three of 14 (21%) metastatic renal cell
carcinoma patients responded, and a similar multicenter trial demonstrated a 29%
response rate. Among 188 metastatic renal cell carcinoma patients treated with
inhaled recombinant IL-2 at the Clinic Eppendorf, progression of pulmonary
metastases was prevented in 68% of patients for a median duration of 7 months,
and overall survival was significantly improved compared with expected survival
(Elson's risk analysis; 17.2 vs 5.3 mo). All patients, including high-risk
patients, appeared to benefit. Encouraging results have also been reported in
patients with metastatic melanoma and gynecologic tumors when inhaled IL-2 was
used as second-line therapy to treat pulmonary metastases. CONCLUSIONS: The
efficacy of inhaled IL-2, alone or in combination with systemic immunotherapy,
immunochemotherapy, or chemotherapy, has been documented in a variety of
malignancies. All reports confirm low toxicity, thus providing important quality
of-life benefits. Moreover, patients not eligible for systemic IL-2 therapy may
be treated with inhalation therapy.
PMID- 10685670
TI - Central auditory processing disorders and reduced motivation: three case studies.
AB - The central auditory test results for three normal-hearing children who were
initially diagnosed as having a central auditory processing disorder and learning
disability are presented. They were referred to the authors for second-opinion
consultations. Central auditory processing retesting was performed by the authors
under the condition of no reinforcement and then the condition of reinforcement
with the child's favorite food, hobby, or toy. For all three cases, the central
auditory test scores improved markedly bilaterally under the condition of
reinforcement as compared with the condition of no reinforcement. We hypothesize
that the improvement was related to increased motivation associated with the
reinforcement and that these children represented false-positive results on the
central auditory test battery. Large-sample studies are needed to investigate the
effect of reinforcement on test performance in children with reduced central
auditory test scores.
PMID- 10685671
TI - Reconsidering the limits of normal hearing.
AB - A proposal is made that 15 dB HL, rather than 25 dB HL, be considered the upper
limit of normal hearing sensitivity. This recommendation is based on an
explanation of the change from an earlier philosophy and the fact that so many
people with hearing levels that average less than 25 dB HL consider themselves to
have hearing difficulty. Such reclassification of people with slight to mild
hearing losses would dignify their clinical complaints and aid in counseling that
would assist them with their hearing difficulties.
PMID- 10685672
TI - Self-reported hearing handicap and audiometric measures in older adults.
AB - As part of an epidemiologic study of hearing disorders in older adults,
audiometric thresholds (250-20,000 Hz), word recognition performance
(Northwestern University Auditory Test No. 6 word lists in quiet and in competing
message), and Hearing Handicap Inventory for the Elderly-Screening (HHIE-S)
scores were evaluated for 3178 adults ranging in age from 48 to 92 years.
Overall, higher HHIE-S scores were more prevalent for older age groups and for
greater degrees of hearing loss. After adjusting for the degree of hearing loss,
the probability of reporting a hearing disability (handicap) decreased with age.
PMID- 10685673
TI - Self-perceived balance disability/handicap in the presence of bilateral
peripheral vestibular system impairment.
AB - The purpose of this report was to characterize the self-perceived balance
disability/handicap of patients with bilateral reductions and bilateral complete
losses of peripheral vestibular system function. Data from 72 patients whose
electronystagmography and rotational examinations suggested normal, unilateral,
or bilateral reductions in peripheral vestibular system function were used in the
first investigation. Patients also completed a Dizziness Handicap Inventory
(DHI). Results demonstrated significant group differences for DHI total and
physical subscale scores. There were significant differences between normal and
bilateral weakness groups for the total DHI score and between normal and
unilateral and normal and bilateral weakness groups for the physical subscale
score. In a second investigation, an item analysis of the DHI is presented for
five patients with bilateral complete losses of peripheral vestibular system
function. Results show that, predictably, these patients have difficulty engaging
in activities requiring an intact vestibulocular reflex (e.g., physical
activities such as sports, household chores).
PMID- 10685674
TI - Acquiring counseling skills in mid-career: outcomes of a distance education
course for practicing audiologists.
AB - Although considered an essential component of audiology service delivery,
counseling skills often are not adequately addressed in graduate training
programs. One of the many goals of the audiology doctorate is to address this
deficit by providing formal course work in counseling for both traditional
graduate students and practitioners. This study describes the outcomes of a
counseling class taught via distance education to mid-career audiologists, who
initially were found to provide informational or technical responses to affective
patient comments (a so-called "communication mismatch"). In spite of inherent
limitations in electronic instruction, students demonstrated learning outcomes
comparable to those obtained from conventional classroom instruction, including
an improvement in their ability to respond to the affective nature of patient
comments.
PMID- 10685675
TI - Interlist equivalency of the Northwestern University Auditory Test No. 6 in quiet
and noise with adult hearing-impaired individuals.
AB - The purpose of the study was to determine the influence of sensorineural hearing
loss and broadband noise on the interlist equivalency of the Northwestern
University Auditory Test No. 6 (NU-6). There were two groups of participants: the
first group consisted of 14 adults with mild-to-moderate hearing loss (mean age =
56 years; SD = 4.83); the second group consisted of 11 age-matched, normal
hearing individuals (mean age = 55 years; SD = 4.69). Each group heard the four
lists of the NU-6 in quiet and in broadband noise at four signal-to-noise ratios
(-10 dB, -5 dB, 0 dB, and +5 dB). The NU-6 stimuli were presented at 35-dB
sensation level relative to each listener's speech reception threshold. Results
indicated that, for both groups, there was a significant main effect for NU-6
list. Post hoc single degree of freedom contrasts revealed that this main effect
was due to significant differences between some of the lists when presented in
background noise. There were no differences between the lists in quiet. Because
of the findings of differences between some of the lists in noise, the authors
suggested that clinicians or researchers use caution when comparing scores
obtained from two different NU-6 lists over time. That is, if scores from two
lists are different, it is important for the clinician to determine whether this
disparity is due to a change in word recognition ability or simply due to a
difference between the lists.
PMID- 10685676
TI - Developmental changes in aural acoustic admittance measurements.
AB - Tympanometry is a clinical measurement routinely included in the assessment of
middle ear function. Despite its widespread use, however, fundamental questions
remain regarding the need for age-dependent normative data. This study examines
normal developmental changes associated with four tympanometric measurements: (1)
ear canal volume, (2) peak compensated acoustic admittance, (3) tympanometric
width, and (4) tympanometric peak pressure. Of 221 infants and children, aged 6
months to 5 years, enrolled in this study, 99 met the criteria for normal middle
ear function as determined via pneumatic tympanoscopy by an experienced pediatric
otolaryngologist, and data analysis was confined to those 99 volunteers. Analysis
of variance revealed statistically significant main effects showing increases in
ear canal volume and peak compensated acoustic admittance and decreases in
tympanometric width as age increased. Statistically significant differences were
not achieved for tympanometric peak pressure. Although statistically significant
differences were found, the differences were small and of questionable clinical
significance.
PMID- 10685677
TI - Twenty-stimulus train for rapid acquisition of auditory brainstem responses in
humans.
AB - This study addressed the clinical need to obtain frequency-specific auditory
brainstem responses (ABRs) more rapidly than is currently possible. ABRs were
obtained from 20 subjects using two different methods: a conventional method with
tone bursts presented singly and a multiple-stimulus method using a train of 20
tone bursts. For both methods, tone bursts were presented at frequencies 1, 2, 4,
and 8 kHz, shaped with a Blackman-Harris window and having intensity levels up to
105 dB peak equivalent sound pressure level (peSPL). The single tone bursts were
presented at a 17.2/sec repetition rate. The 20 tone-burst train used the four
frequencies at five intensities each and a repetition rate of 3.7/sec
(separations between tone bursts of 9-12 msec, with 77 msec off-time between
trains). Mean latencies and mean amplitudes for wave V were compared using t
tests for each of 12 conditions (four frequencies, each at the three highest
output levels). For latency, only one comparison was significantly different (2
kHz, 77 dB peSPL). Similarly, only one comparison was significant for amplitude
(2 kHz, 97 dB peSPL). There was, however, a trend for the tone bursts presented
in trains to have longer latencies and reduced amplitudes compared to the
respective responses for the single tone-burst condition. These results indicate
the presence of some response adaptation when tone bursts are presented in a
train. The use of a properly designed stimulus train can result in a significant
time savings for obtaining frequency-specific ABRs as compared with single tone
burst presentations.
PMID- 10685678
TI - Identification of matrix metalloproteinases in canine neoplastic tissue.
AB - OBJECTIVE: To identify matrix metalloproteinases (MMP) 2 and 9 in canine tumor
tissue and to compare the amount of activity to that in unaffected stromal
tissue. ANIMALS: 30 dogs with spontaneously developing, high-grade osteosarcoma.
PROCEDURE: Tumor and nearby stromal tissue (muscle) were obtained at the time of
surgery. Specimens were homogenized, and supernatants were assayed, using gelatin
zymography. Human derived standards were run concurrently. Densitometry was done
to obtain a semiquantitative arbitrary unit value for each specimen. The amount
of activity in tumor tissue was compared with the amount in stromal tissue.
RESULTS: Gelatinolytic bands were observed from the analysis of all tumor tissues
and in most stromal tissues. These bands migrated in the same molecular weight
area as the human MMP 2 and 9 standards. Gelatinolytic activity could be quenched
by the addition of 50 mM EDTA and 1 microg of synthetic tissue inhibitor of
metalloproteinase (TIMP) 2 per 100 ml. There was significantly more gelatinolytic
activity in tumor tissue than in stromal tissue. CONCLUSIONS AND CLINICAL
RELEVANCE: MMP 2 and 9 are detectable in canine neoplastic tissue. Matrix
metalloproteinases activity in tumor tissue is higher than in unaffected stromal
tissue, indicating that canine MMP may be involved in the pathogenesis of tumor
growth and metastasis.
PMID- 10685679
TI - Inheritance of von Willebrand's disease in a colony of Doberman Pinschers.
AB - OBJECTIVE: To determine the mode of inheritance of von Willebrand's disease (vWD)
and perform linkage analysis between vWD and coat color or narcolepsy in a colony
of Doberman Pinschers. ANIMALS: 159 Doberman Pinschers. PROCEDURE: von Willebrand
factor antigen (vWF:Ag) concentration was measured by use of ELISA, and results
were used to classify dogs as having low (< 20%), intermediate (20 to 65%), or
high (> 65%) vWF:Ag concentration, compared with results of analysis of standard
pooled plasma. Buccal bleeding time was measured, and mode of inheritance of vWD
was assessed by pedigree analysis. RESULTS: von Willebrand's disease was
transmitted as a single autosomal gene defect. Results suggested that 27.04% of
dogs were homozygous for vWD, 62.26% were heterozygous, and 10.69% did not have
the defect. Most homozygous and some heterozygous dogs had prolonged bleeding
times. Dogs with diluted coat colors (blue and fawn) were significantly
overrepresented in the homozygous group, compared with black and red dogs, but a
significant link between vWD and coat color was not detected. CONCLUSIONS AND
CLINICAL RELEVANCE: von Willebrand's disease is transmitted as an autosomal
dominant trait with variable penetrance; most dogs in this colony (89.3%) were
carriers of vWD. Homozygosity for vWD is not likely to be lethal. Some
heterozygous dogs have prolonged bleeding times. An association between diluted
coat colors and vWD may exist.
PMID- 10685680
TI - Effects of general anesthesia and surgery on renal function in healthy dogs.
AB - OBJECTIVES: To evaluate renal function in healthy dogs undergoing general
anesthesia and ovariohysterectomy without concurrent IV administration of fluids.
ANIMALS: 35 healthy client-owned dogs. PROCEDURE: Dogs were medicated with
promazine hydrochloride (0.05 mg/kg of body weight, SC) approximately 45 minutes
before induction of anesthesia with thiopental sodium (10 to 15 mg/kg, IV).
Anesthesia was maintained with 2% halothane in oxygen. Ovariohysterectomies were
performed by senior veterinary students under the direct supervision of a
veterinary surgeon. Renal function was assessed (serum urea and creatinine
concentrations, fractional clearance of sodium, urine alkaline phosphatase [ALP]
and gamma-glutamyltransferase [GGT] activities, urine specific gravity, and
enumeration of renal tubular epithelial cells in urine sediment) prior to and 24
and 48 hours after surgery. RESULTS: Duration of general anesthesia ranged from
80 to 310 minutes. Urine specific gravity and ALP activity and serum urea and
creatinine concentrations did not change over time. Fractional clearance of
sodium decreased 24 and 48 hours after surgery, whereas urine GGT activity and
the ratio of urine GGT activity to urine creatinine concentration increased 24
hours after surgery, compared with presurgery values. Renal tubular epithelial
cells increased in number in urine sediment from 11 of 35 (31.4%) dogs and 5 of
35 (14.3%) dogs 24 and 48 hours after surgery, respectively. However, this
increase was not clinically relevant. CONCLUSIONS AND CLINICAL RELEVANCE:
Intravenous administration of fluids to healthy dogs undergoing general
anesthesia and elective surgery may not be necessary for maintenance of renal
homeostasis.
PMID- 10685681
TI - Transformation and transposition of the genome of Mycobacterium marinum.
AB - OBJECTIVE: To develop and evaluate protocols for genetic manipulations
(transformation and transposition) of the fish pathogen, Mycobacterium marinum.
SAMPLE POPULATION: Isolates of M. marinum obtained from fish and humans.
PROCEDURE: Electrocompetent cells were prepared from isolates of M. marinum grown
to various growth phases at several temperatures and with or without the addition
of ethionamide or cycloheximide. Mycobacterial cells were transformed by
electroporation with a replicative Escherichia coli-mycobacteria shuttle vector
(pYUB18) as well as suicide vectors (pYUB285 and pUS252) that carried
transposable elements (IS1096 and IS6110, respectively). Mutants from both
isolates of M. marinum were recovered on 7H10 agar plates supplemented with
kanamycin. Transformation and transposition efficiencies for various protocols
were compared. Southern hybridization analysis was performed on mycobacterial
mutants to confirm transposition events. RESULTS: Competent cells prepared at
room temperature (23-25 C) from organisms in late-exponential growth phase
yielded higher transposition efficiency, compared with cells prepared at 4 C or
from organisms in early- or mid-exponential growth phase. Naturally developing
kanamycin-resistant colonies of M. marinum were not detected. Only the IS1096
derived transposition was able to efficiently mutate M. marinum. Southern
hybridization of M. marinum mutants revealed random integration of IS 1096 into
the M. marinum genome. CONCLUSIONS: Transposition and transformation efficiencies
were comparable, suggesting that the limiting factor in transposition is the
transformation step. Most of the experiments resulted in transposition of IS1096;
however, better approaches are needed to improve transposition efficiency.
PMID- 10685682
TI - Development of an in vitro fluorometric assay to study adherence of Pasteurella
haemolytica to bovine cells.
AB - OBJECTIVE: To develop an in vitro fluorometric assay to assess Pasteurella
haemolytica adherence to bovine respiratory and epithelial cells and compare
adherence of single strains of P. haemolytica serovars A1 and A2 (PhA1 and PhA2,
respectively). SAMPLE POPULATION: Monolayers of bovine turbinate and Madin Darby
bovine kidney (MDBK) cells. PROCEDURE: To determine optimal inoculum
concentration and incubation time, various concentrations of P. haemolytica were
labeled with fluorescein isothiocyanate and incubated with monolayers of bovine
cells for various times. Bovine cells were washed to remove nonadherent bacteria,
and percentage of bacteria adhered (percentage of adherence) was estimated
fluorometrically. Percentage of adherence of PhA1 was compared with that of PhA2.
RESULTS: The optimal inoculum concentration that resulted in measurable
fluorescence of adherent bacteria was 1 x 10(8) colony-forming units/ml, and the
optimal incubation time was 45 minutes. Percentage of adherence of PhA1 to MDBK
and turbinate cells was significantly greater than that determined for PhA2.
CONCLUSIONS: The in vitro fluorometric assay is a time-efficient, inexpensive,
and labor-saving method for evaluation of P. haemolytica adherence to bovine
cells. The concentration of bacteria used to inoculate bovine cells in this assay
is similar to that typically used in other types of in vitro adherence assays.
The predominance of PhA1 over PhA2 during the early stages of bovine respiratory
disease may be attributable to the ability of PhA1 to adhere more avidly to
nasopharyngeal tissue.
PMID- 10685683
TI - Comparison of sensitivity of sodium currents to tetrodotoxin in equine muscle
specimens with that in murine and human muscle specimens.
AB - OBJECTIVE: To determine sensitivity of equine skeletal muscle to tetrodotoxin and
compare that with sensitivity of murine and human skeletal muscles. SAMPLE
POPULATION: Semimembranosus, vastus lateralis, triceps brachii, and masseter
muscle specimens from 22 euthanatized horses, vastus lateralis muscle biopsy
specimens from 25 clinically normal humans, and diaphragmatic muscle specimens
from 6 mice. PROCEDURE: Electrically elicited twitch responses were measured in
muscle specimens incubated in medium alone and with tetrodotoxin (100 nM, 400 nM,
1.6 microM for equine specimens and 100 nM, 200 nM, 400 nM, 800 nM, 1.6 microM
for murine and human specimens). Percentages of tetrodotoxin-sensitive and
resistant sodium channels were determined and compared among muscles and species.
RESULTS: 2 sodium channels with different sensitivities to tetrodotoxin were
identified in equine muscle. One was blocked with 100 nM tetrodotoxin and the
other was unaffected by tetrodotoxin at concentrations up to 1.6 microM. The only
difference detected among the 4 equine muscles was that masseter muscle specimens
had a higher percentage of tetrodotoxin-sensitive channels than triceps brachii
muscle specimens. Tetrodotoxin-resistant sodium channels constituted 31 to 66% of
the equine muscle twitch response, which was greater than that determined for
normal human and murine muscle (< 5%). CONCLUSION AND CLINICAL RELEVANCE: Equine
skeletal muscle contains a high percentage of tetrodotoxin-resistant sodium
channels. The 4 equine muscles evaluated were more similar to each other than to
murine and human muscles. Shifts in expression of sodium channel subtypes may
play a role in the manifestation of certain myopathies.
PMID- 10685684
TI - Histologic and immunohistochemical characterization of lens capsular plaques in
dogs with cataracts.
AB - OBJECTIVE: To determine histologic and immunohistochemical characteristics of the
multifocal adherent plaques that commonly develop on the internal surfaces of the
anterior and posterior lens capsules in dogs with cataracts. SAMPLE POPULATION:
31 anterior and 4 posterior capsular specimens collected during lens extraction
surgery in dogs with cataracts. PROCEDURE: Specimens were evaluated, using light
and transmission electron microscopy. Immunohistochemical techniques were used to
localize cytokeratin, vimentin, alpha-smooth muscle-specific actin, fibronectin,
tenascin, and transforming growth factor-beta (TGF-beta) within plaques. RESULTS:
Histologically, plaques comprised elongated spindle-shaped cells that formed a
placoid mass. Cells were embedded in an extracellular matrix containing collagen
fibrils, often with duplicated or split basement membranes.
Immunohistochemically, normal lens epithelial cells and cells within plaques
stained for vimentin. Most cells and some areas of the extracellular matrix
within plaques stained for TGF-beta and alpha-smooth muscle-specific actin.
Fibronectin and tenascin were also detected in the extracellular matrix.
CONCLUSIONS AND CLINICAL RELEVANCE: Canine lens capsular plaques are
histologically and immunohistochemically similar to posterior capsule
opacification and subcapsular cataracts in humans, which suggests that the canine
condition, like the human conditions, is associated with fibrous metaplasia of
lens epithelial cells. Transforming growth factor-beta may play a role in the
genesis of capsular plaques. Because severity of plaques was correlated with
stage of cataract development, earlier surgical removal of cataracts may be
useful to avoid complications associated with plaque formation.
PMID- 10685685
TI - Determination of the lactate breakpoint during incremental exercise in horses
adapted to dietary corn oil.
AB - OBJECTIVE: To determine lactate breakpoint of horses and test for effects of
training and dietary supplementation with corn oil on that breakpoint. ANIMALS: 7
healthy Arabian horses. PROCEDURES: Horses received a control diet (n = 4) or a
diet supplemented with 10% corn oil (4). A training program, which comprised two
5-week conditioning periods with 1 week of rest, was initiated. Submaximal
incremental exercise tests (IET) were conducted before the first and after both
conditioning periods. Blood samples for determination of blood lactate and plasma
glucose concentrations were collected 1 minute before IET and during the 15
seconds immediately preceding each speed change. Data collected were fit to one-
and two-slope broken-line models and an exponential model. RESULTS: Good fits
were obtained by application of the broken-line models (adjusted R2 > 0.92) to
blood lactate concentration versus speed curves. Lactate breakpoints increased
41% after training. After training, slope 2 and peak blood lactate concentrations
were greater in the corn oil group, compared with controls. Mean blood lactate
concentration at the breakpoint was not affected by training or diet. Plasma
glucose concentration versus speed curves also fit the broken-line models, and
glucose breakpoints preceded lactate breakpoints by approximately 1 m/s in the
second and third IET. CONCLUSIONS AND CLINICAL RELEVANCE: Lactate breakpoints can
be determined for horses, using blood lactate concentration versus speed curves
generated during submaximal IET and may be useful for assessing fitness and
monitoring training programs in equine athletes.
PMID- 10685686
TI - Hepatic and pulmonary enzyme activities in horses.
AB - OBJECTIVE: To determine hepatic and pulmonary phase-I and phase-II enzyme
activities in horses. SAMPLE POPULATION: Pulmonary and hepatic tissues from 22
horses that were 4 months to 32 years old. PROCEDURE: Pulmonary and hepatic
tissues from horses were used to prepare cytosolic (glutathione S-transferase and
soluble epoxide hydrolase) and microsomal (cytochrome P450 monooxygenases)
enzymes. Rates of microsomal metabolism of ethoxyresorufin, pentoxyresorufin, and
naphthalene were determined by high-performance liquid chromatography. Activities
of glutathione S-transferase and soluble epoxide hydrolase were determined
spectrophotometrically. Cytochrome P450 content was determined by carbon monoxide
bound-difference spectrum of dithionite-reduced microsomes. Activity was
expressed relative to total protein concentration. RESULTS: Microsomal protein
and cytochromeP450 contents were detectable in all horses and did not vary with
age. Hepatic ethoxyresorufin metabolism was detected in all horses; by
comparison, pulmonary metabolism of ethoxyresorufin and hepatic and pulmonary
metabolism of pentoxyresorufin were detected at lower rates. Rate of hepatic
naphthalene metabolism remained constant with increasing age, whereas rate of
pulmonary naphthalene metabolism was significantly lower in weanlings (ie, horses
4 to 6 months old), compared with adult horses. Hepatic glutathione S-transferase
activity (cytosol) increased with age; however, these changes were not
significant. Pulmonary glutathione S-transferase activity (cytosol) was
significantly lower in weanlings than adult horses. Hepatic and pulmonary soluble
epoxide hydrolase did not vary with age of horses. CONCLUSIONS AND CLINICAL
RELEVANCE: Activity of cytochrome P450 isoforms that metabolize naphthalene and
glutathione S-transferases in lungs are significantly lower in weanlings than
adult horses, which suggests reduced ability of young horses to metabolize
xenobiotics by this organ.
PMID- 10685687
TI - Fungal flora on cutaneous and mucosal surfaces of cats infected with feline
immunodeficiency virus or feline leukemia virus.
AB - OBJECTIVE: To compare cutaneous and mucosal mycoflora in cats infected with FIV
or FeLV with that in noninfected cats. ANIMALS: 85 client-owned cats; 24
seropositive for FIV, 10 seropositive for FeLV, 1 seropositive for both viruses,
and 50 seronegative for both viruses. PROCEDURE: Cutaneous specimens were
obtained from the coat and external acoustic meatus (ear canal) and mucosal
specimens from the oropharynx and rectum. Fungi were isolated from specimens,
using Sabouraud dextrose agar incubated at 27 or 37 C for cutaneous and mucosal
specimens, respectively. RESULTS: Fungal colonies were cultured from at least 1
specimen from 83 of 85 (97.6%) cats. The most common fungal isolates were
Aspergillus spp (cultured from 59.3% of all specimens), Penicillium spp (50.0%),
Cladosporium spp (44.2%), Scopulariopsis spp (41.8%), and lipophilic yeasts of
the genus Malassezia (31.4%). A greater diversity of fungal genera was isolated
from retrovirus-infected cats, and Malassezia spp were more commonly recovered
from these cats, compared with noninfected cats. Candida albicans, Cryptococcus
neoformans, and dermatophytes (eg, Microsporum canis) were rarely isolated from
any cat. Significant differences in frequency of isolation of C. neoformans and
dermatophytes were not found between infected and noninfected cats. CONCLUSIONS
AND CLINICAL RELEVANCE: Cats infected with FIV or FeLV may have a greater
diversity of cutaneous and mucosal mycoflora than noninfected cats. However,
infected cats may be no more likely than noninfected cats to expose humans to
zoonotic fungi such as C. albicans, C. neoformans, and M. canis.
PMID- 10685688
TI - Comparison of the phenotypes of Streptococcus zooepidemicus isolated from tonsils
of healthy horses and specimens obtained from foals and donkeys with pneumonia.
AB - OBJECTIVE: To determine whether streptococcal pneumonia is caused by strains of
Streptococcus zooepidemicus similar to those obtained from the tonsils of healthy
horses. SAMPLE POPULATION: 5 tonsils from healthy horses, 8 tracheal washes and 6
lung specimens from foals with pneumonia, and 5 nasopharyngeal swab specimens
from donkeys with acute bronchopneumonia. PROCEDURE: Variable M-like protectively
immunogenic SzP proteins of 5 isolates of S. zooepidemicus from each tonsil and
clinical specimen were compared, using immunoblots. The SzP gene of 13 isolates
representative of various SzP immunoblot phenotypes from 1 healthy horse and 9
horses and donkeys with pneumonia were sequenced and compared. Cell-associated
hyaluronic acid concentration and resistance to phagocytosis of some isolates
were measured. RESULTS: Tonsils of each healthy horse were colonized by several
SzP phenotypes similar to those of foals or donkeys with pneumonia. In contrast,
multiple isolates from animals with pneumonia had the same SzP phenotype,
indicating infection by a single strain or clone. Analysis of the SzP sequence
confirmed that differences in immunoblot phenotype were associated with sequence
differences and that several SzP genotypes were in healthy horses and animals
with pneumonia. Isolates with high concentrations of cell-associated hyaluronic
acid were more resistant to phagocytosis. CONCLUSIONS AND CLINICAL RELEVANCE: An
SzP-specific immunoblot is a useful, sensitive measure of diversity among strains
of S. zooepidemicus. Single strains with SzP phenotypes similar to those found in
tonsils of healthy horses cause pneumonia. Because of the diversity of SzP
phenotype and genotype among isolates from animals with pneumonia, SzP phenotype
is not an important determinant of invasiveness or epizootic capabilities.
PMID- 10685689
TI - Correlation of clinical score, intrapleural pressure, cytologic findings of
bronchoalveolar fluid, and histopathologic lesions of pulmonary tissue in horses
with summer pasture-associated obstructive pulmonary disease.
AB - OBJECTIVE: To correlate clinical score, intrapleural pressure, cytologic findings
of bronchoalveolar lavage fluid (BALF), and histologic lesions of pulmonary
tissue in horses affected with summer pasture-associated obstructive pulmonary
disease (SPAOPD). ANIMALS: 8 adult horses affected with SPAOPD and 6 adult horses
without evidence of respiratory tract disease. PROCEDURE: Clinical score, change
in intrapleural pressure (deltaPpl) during tidal breathing, results of cytologic
examination and bacteriologic culture of BALF, and results of histologic
examination of pulmonary parenchyma were evaluated. RESULTS: Clinical scores for
SPAOPD-affected horses (median, 5.75; range, 4.0 to 7.5) were significantly
greater, compared with clinically normal horses (median, 2.0; range, 2.0 to 3.0).
Cytologic examination of BALF from SPAOPD-affected horses revealed predominantly
nondegenerate neutrophils. Histologic lesions were identified throughout
pulmonary tissue and included severe accumulation of mucus and neutrophils within
the small airways, metaplasia of bronchiolar goblet cells, and mild peribronchial
infiltrate. Histologic examination of specimens collected via percutaneous biopsy
was predictive of disease and corresponded to findings at postmortem examination.
Clinical score and deltaPpl were highly correlated with mucus accumulation in the
airways of affected horses. Peribronchial inflammatory infiltrate correlated with
percentage of neutrophils in BALF of affected horses. CONCLUSIONS AND CLINICAL
RELEVANCE: Clinical scoring and deltaPpl provided valid estimates of disease
severity. Findings from cytologic examination of BALF of SPAOPD-affected horses
varied, although, in most instances, it was diagnostically useful. Severe mucus
accumulation in the airways was the most remarkable histopathologic finding in
SPAOPD-affected horses. Examination of biopsy specimens collected from pulmonary
parenchyma was consistently useful in diagnosing SPAOPD.
PMID- 10685690
TI - Ultrastructural changes in follicles of small-intestinal aggregated lymphoid
nodules in early and advanced phases of experimentally induced mucosal diseases
in calves.
AB - OBJECTIVE: To investigate ultrastructural changes in follicles of small
intestinal aggregated lymphoid nodules (Peyer's patches) of calves with early and
advanced phases of experimentally induced mucosal disease (MD). ANIMALS: Twenty
2.5- to 7-month-old Holstein-Friesian calves (11 females, 9 males). PROCEDURE: MD
was induced in 13 of 18 calves that were persistently viremic with bovine viral
diarrhea virus (BVDV). Eight of the 13 calves were euthanatized before the onset
of clinical signs of MD, and 5 were euthanatized after becoming moribund with MD.
Five persistently viremic calves and 2 calves without BVDV served as controls.
Specimens of small-intestinal aggregated lymphoid nodules were prepared for
transmission electron microscopy. RESULTS: The ultrastructure of follicles of
small-intestinal aggregated lymphoid nodules from healthy calves was consistent
with that in sheep. In the early phase of MD, changes were characterized by
numerous apoptotic lymphocytes and macrophages with apoptotic bodies. In more
advanced lesions, affected lymphoid follicles consisted of macrophages and
variable numbers of follicular dendritic cells (FDC), whereas others did not
contain FDC. In moribund calves, small follicles consisting predominantly of FDC
and follicles with central cavities surrounded by macrophages, and few
neutrophils were observed. CONCLUSIONS AND CLINICAL RELEVANCE: The
ultrastructural changes in lymphoid follicles of small-intestinal aggregated
lymphoid nodules indicate apoptosis of lymphocytes as an initial event. The
development of small follicles consisting predominantly of FDC or the complete
loss of follicular architecture in advanced phases of MD is determined by the
intensity of apoptosis of lymphocytes, the capacity of the macrophages for
uptake, and the reorganization of a stromal network.
PMID- 10685691
TI - Doppler ultrasonographic features of thoracic limb arteries in clinically normal
horses.
AB - OBJECTIVES: To determine blood flow velocities and indices from spectral
waveforms obtained by use of Doppler ultrasonography of thoracic limb arteries of
horses and to assess interobserver and patient variability associated with the
technique. ANIMALS: 9 clinically normal adult horses. PROCEDURE: Left thoracic
limb arteries of 8 nonsedated horses were examined at 5 sites by use of pulsed
wave Doppler ultrasonography to determine a range of values for peak systolic,
end diastolic, and mean velocities and resistive and pulsatility indices.
Interobserver and patient variabilities were determined by 2 operators repeating
similar measurements on 1 horse 8 times at weekly intervals. RESULTS: A range of
values for each variable measured at the 5 selected sites was obtained. For each
variable, strong positive correlations (R > or = 0.7) were detected for > 70% of
the site-to-site comparisons made (excluding the coronary band). Among horses,
resistive index varied least, whereas over time, mean velocity varied least.
Waveform characteristics were consistent with resistive (n = 5) or nonresistive
(4) patterns. In the single-horse experiment, waveform characteristics were
consistent throughout the 8 weeks, and operator effects were not detected.
CONCLUSIONS AND CLINICAL RELEVANCE: Doppler ultrasonography of no one site
resulted in more reliable measurements of blood flow characteristics in thoracic
limb arteries of horses. Mean velocity and resistive index were the least
variable measurements made. Pulsed-wave Doppler ultrasonography may be a useful
technique for evaluating diseases that alter normal thoracic limb arterial blood
flow in horses.
PMID- 10685692
TI - Kinematics and ground reaction forces in horses with superficial digital flexor
tendinitis.
AB - OBJECTIVE: To measure and correlate kinematic and ground reaction force (GRF)
data in horses with superficial digital flexor tendinitis. ANIMALS: 6 sound
horses. PROCEDURE: Horses were evaluated before (sound evaluation) and after
(lame evaluation) induction of superficial digital flexor tendinitis in 1
forelimb (randomized) by injection of collagenase. As each horse trotted,
kinematic data were collected by use of an optoelectronic system, and GRF data
were measured by use of a force plate. Three-dimensional kinematic and GRF data
were projected onto a 2-dimensional sagittal plane. RESULTS: Lame limbs had
significantly lower peak vertical GRF, less flexion of the distal interphalangeal
joint, and less extension of the metacarpophalangeal joint, compared with
compensating limbs. Carpal joint kinematics did not change. Compensating limbs
had a more protracted orientation throughout the stance phase and higher braking
longitudinal force and impulse; however, total range of rotation from ground
contact to lift off did not change. Transfer of body weight from lame to
compensating limbs was smooth, without elevation of the body mass into a
suspension phase. Propulsive components of longitudinal GRF did not differ
between limbs. CONCLUSIONS AND CLINICAL RELEVANCE: In horses with experimentally
induced superficial digital flexor tendinitis, changes in vertical GRF were
reflected in angular excursions of the distal interphalangeal and
metacarpophalangeal joints, whereas changes in longitudinal GRF were associated
with alterations in the protraction-retraction angle of the entire limb.
PMID- 10685693
TI - Net joint moments and joint powers in horses with superficial digital flexor
tendinitis.
AB - OBJECTIVE: To determine whether analysis of net joint moments and joint powers is
a suitable technique for evaluation of mechanics and energetics of lameness in
horses and to measure effects of superficial digital flexor tendinitis. ANIMALS:
6 sound horses. PROCEDURE: Horses were evaluated before (sound evaluation) and
after (lame evaluation) induction of superficial digital flexor tendinitis in 1
forelimb by injection of collagenase. Recordings were made with an optoelectronic
system and a force plate as horses trotted. Net joint moments and joint powers in
the sagittal plane at each joint in the forelimbs during the stance phase were
determined. Peak values were determined, and mechanical energy absorbed and
generated at each joint was calculated. Comparisons were made between
contralateral limbs during sound and lame evaluations. RESULTS: Lame limbs had
significant reductions in peak values for net joint moments on the palmar aspect
of metacarpophalangeal (fetlock), carpal, and humeroulnar joints. Total energy
absorbed was significantly lower at every joint in lame limbs, compared with
compensating limbs. CONCLUSIONS AND CLINICAL RELEVANCE: Horses with superficial
digital flexor tendinitis had significant differences between lame and
compensating limbs for net joint moments and joint powers at all joints,
indicating that the gait of horses with superficial digital flexor tendinitis is
energetically inefficient. Assessment of net joint moments and joint powers is a
useful tool in evaluating equine lameness.
PMID- 10685694
TI - Structure-related echoes in ultrasonographic images of equine superficial digital
flexor tendons.
AB - OBJECTIVE: To develop a method to discriminate between structure-related echoes
and echoes resulting from interference, as observed in transverse
ultrasonographic images of equine superficial digital flexor (SDF) tendons.
SAMPLE POPULATION: 2 normal (injury-free) SDF tendons obtained from a 3-year-old
Thoroughbred and a 9-year-old Dutch Warmblood horse. PROCEDURE: Tendons were
mounted in a custom-made device that permitted exact transverse and perpendicular
sequential scanning with precise steps of 0.5 mm along the long axis of the
tendon. Photographs of transverse tendon sections at the exact scanning locations
were obtained. Propagation, reflection, and refraction artifacts were quantified,
and an image rectification procedure was developed, allowing exact matching of
each photograph with the corresponding ultrasonographic image. A correlation
routine was developed that departed from this transverse ultrasonographic image
(position 0); this routine added information from images collected at precise
distances of 0.5 and 1 mm on both sides of the actual scan location (positions
2, -1, +1, +2). RESULTS: By use of the correlation routine, echoes that remained
steady over all 5 images were enhanced and resolved, and constantly changing
echoes were multiplicatively reduced and faded. This correlated image could be
projected over the rectified photograph, and the resolved echoes matched
perfectly with the endotendon septa surrounding fibers and fasciculi. CONCLUSIONS
AND CLINICAL RELEVANCE: The correlation routine permits exclusive resolution of
structure-related echoes, as echoes resulting from interference are faded. The
technique described can produce images that depict only the essential structure
related information. In this way, the clinical assessment of tendon integrity is
greatly facilitated.
PMID- 10685695
TI - Ultrasonographic tissue characterization of equine superficial digital flexor
tendons by means of gray level statistics.
AB - OBJECTIVE: To correlate quantitative analysis of ultrasonographic images of
normal (injury-free) equine superficial digital flexor (SDF) tendons and equine
SFD tendons that have pathologic changes with corresponding histologic sections.
SAMPLE POPULATION: 4 SDF tendons, 2 of which had various stages of tissue
integrity. The 2 ipsilateral tendons were used as points of reference. PROCEDURE:
Tendons were mounted in a custom-made device that permitted sequential scanning,
transversely and perpendicular to the tendon long axis. At precise steps of 0.5
mm, transverse ultrasonographic images were collected. Subsequently, tendons were
fixed and prepared for histologic examination. The following 8 tissue types were
discerned: normal young, normal old, necrotic, early granulation, late
granulation, early fibrotic, late fibrotic, and scar tissues. In areas of
interest, the corresponding ultrasonographic images were selected for gray level
statistical analysis. RESULTS: Compared with other tissue types, early-stage
granulation tissue was characterized by substantially lower mean gray level and a
clearly different histogram. Necrotic tissue had a higher mean gray level, with a
virtually normal histogram. In late granulation and early fibrotic tissues, the
mean gray level and the histogram could not be discerned from those of normal
tendon tissue. The same applied to late fibrotic and scar tissues; mean gray
levels were fractionally lower than those of normal tendon tissue with a
completely normal histogram. CONCLUSIONS: Although quantification of the
transverse ultrasonographic image by use of first-order gray level statistics may
be helpful, the method is not sufficiently sensitive to accurately and
unequivocally determine the type of tendon tissue. Quantitative analysis should
incorporate transverse and longitudinal information.
PMID- 10685696
TI - Indications for emergent MRI of the central nervous system.
PMID- 10685698
TI - Implant recommendations.
PMID- 10685697
TI - Innovation and service traditional at University of Michigan Medical School.
PMID- 10685699
TI - Stem cell transplants found superior.
PMID- 10685700
TI - From the Centers for Disease Control and Prevention. Recommended childhood
immunization schedule--United States, 2000.
PMID- 10685701
TI - From the Centers for Disease Control and Prevention. Hypothermia-related deaths-
Alaska, October 1998-April 1999, and trends in the United States, 1979-1996.
PMID- 10685702
TI - From the Centers for Disease Control and Prevention. Update: influenza activity-
United States, 1999-2000 season.
PMID- 10685703
TI - Brain injury in amateur soccer players.
PMID- 10685704
TI - Brain injury in amateur soccer players.
PMID- 10685705
TI - Access to antiretroviral therapy.
PMID- 10685706
TI - Access to antiretroviral therapy.
PMID- 10685707
TI - The herbal history of Digitalis: lessons for alternative medicine.
PMID- 10685708
TI - The National Practitioner Data Bank and the quality of peer review.
PMID- 10685709
TI - The National Practitioner Data Bank and the quality of peer review.
PMID- 10685710
TI - The National Practitioner Data Bank and the quality of peer review.
PMID- 10685711
TI - Does prenatal famine cause later antisocial behaviors?
PMID- 10685712
TI - Does prenatal famine cause later antisocial behaviors?
PMID- 10685713
TI - Cost-utility analysis of screening intervals for diabetic retinopathy in patients
with type 2 diabetes mellitus.
AB - CONTEXT: Annual eye screening for patients with diabetes mellitus is frequently
proposed as a measure of quality of care. However, the benefit of annual vs less
frequent screening intervals has not been well evaluated, especially for low-risk
patients. OBJECTIVE: To examine the marginal cost-effectiveness of various
screening intervals for eye disease in patients with type 2 diabetes, stratified
by age and level of glycemic control. DESIGN: Markov cost-effectiveness model.
SETTING AND PARTICIPANTS: Hypothetical patients based on the US population of
diabetic patients older than 40 years from the Third National Health and
Nutrition Examination Survey. MAIN OUTCOME MEASURES: Patient time spent blind,
quality-adjusted life-years (QALYs), and costs of annual vs less frequent
screening compared by age and level of hemoglobin A1c. RESULTS: Retinal screening
in patients with type 2 diabetes is an effective intervention; however, the risk
reduction varies dramatically by age and level of glycemic control. On average, a
high-risk patient who is aged 45 years and has a hemoglobin A1c level of 11%
gains 21 days of sight when screened annually as opposed to every third year,
while a low-risk patient who is aged 65 years and has a hemoglobin A1c level of
7% gains an average of 3 days of sight. The marginal cost-effectiveness of
screening annually vs every other year also varies; patients in the high-risk
group cost an additional $40530 per QALY gained, while those in the low-risk
group cost an additional $211570 per QALY gained. In the US population, retinal
screening annually vs every other year for patients with type 2 diabetes costs
$107510 per QALY gained, while screening every other year vs every third year
costs $49760 per QALY gained. CONCLUSIONS: Annual retinal screening for all
patients with type 2 diabetes without previously detected retinopathy may not be
warranted on the basis of cost-effectiveness, and tailoring recommendations to
individual circumstances may be preferable. Organizations evaluating quality of
care should consider costs and benefits carefully before setting universal
standards.
PMID- 10685714
TI - The International Registry of Acute Aortic Dissection (IRAD): new insights into
an old disease.
AB - CONTEXT: Acute aortic dissection is a life-threatening medical emergency
associated with high rates of morbidity and mortality. Data are limited regarding
the effect of recent imaging and therapeutic advances on patient care and
outcomes in this setting. OBJECTIVE: To assess the presentation, management, and
outcomes of acute aortic dissection. DESIGN: Case series with patients enrolled
between January 1996 and December 1998. Data were collected at presentation and
by physician review of hospital records. SETTING: The International Registry of
Acute Aortic Dissection, consisting of 12 international referral centers.
PARTICIPANTS: A total of 464 patients (mean age, 63 years; 65.3% male), 62.3% of
whom had type A dissection. MAIN OUTCOME MEASURES: Presenting history, physical
findings, management, and mortality, as assessed by history and physician review
of hospital records. RESULTS: While sudden onset of severe sharp pain was the
single most common presenting complaint, the clinical presentation was diverse.
Classic physical findings such as aortic regurgitation and pulse deficit were
noted in only 31.6% and 15.1% of patients, respectively, and initial chest
radiograph and electrocardiogram were frequently not helpful (no abnormalities
were noted in 12.4% and 31.3% of patients, respectively). Computed tomography was
the initial imaging modality used in 61.1%. Overall in-hospital mortality was
27.4%. Mortality of patients with type A dissection managed surgically was 26%;
among those not receiving surgery (typically because of advanced age and
comorbidity), mortality was 58%. Mortality of patients with type B dissection
treated medically was 10.7%. Surgery was performed in 20% of patients with type B
dissection; mortality in this group was 31.4%. CONCLUSIONS: Acute aortic
dissection presents with a wide range of manifestations, and classic findings are
often absent. A high clinical index of suspicion is necessary. Despite recent
advances, in-hospital mortality rates remain high. Our data support the need for
continued improvement in prevention, diagnosis, and management of acute aortic
dissection.
PMID- 10685715
TI - Extracorporeal life support: the University of Michigan experience.
AB - The University of Michigan experience with extracorporeal life support (ECLS) in
1000 consecutive patients between 1980 and 1998 is the largest series at one
institution in the world. Among this patient population, survival to hospital
discharge in moribund patients with respiratory failure was 88% in 586 neonates,
70% in 132 children, and 56% in 146 adults. Survival in moribund patients with
cardiac failure was 48% in 105 children and 33% in 31 adults. This article
describes the University of Michigan's overall ECLS patient experience, the
progression of ECLS from laboratory experiments to clinical application at the
bedside, the expansion of the technology to other centers, and current ECLS
technology and outcomes. Despite the challenges faced in clinical research in
this field, our experience and that of others has shown that ECLS saves lives of
patients with acute cardiac or pulmonary failure in a variety of clinical
settings.
PMID- 10685716
TI - Conflicts regarding decisions to limit treatment: a differential diagnosis.
AB - Conflicts between physicians and families about end-of-life decisions create
challenging and emotionally difficult situations. In this article, we propose a
"differential diagnosis" of such conflicts, distinguishing and describing the
characteristics of families, physicians, and organizations and society that
contribute to the "etiology" of the situation, as well as strategies for
"diagnosing" the dominant factors. As a medical model, the differential diagnosis
can be a useful tool to help physicians understand and manage conflicts about end
of-life care.
PMID- 10685717
TI - The University of Michigan Medical School, 1850-2000: "an example worthy of
imitation".
AB - The 150th anniversary of the University of Michigan Medical School affords
occasion for both celebration and reflection, not just in Ann Arbor but
throughout the world, as we consider its contributions to medical education,
research, and health care over the past century and a half. This article explores
the medical school's origins as a frontier medical outpost and describes the
vital reforms in medical education implemented in Ann Arbor long before the
landmark Flexner Report on Medical Education of 1910. It also depicts how and why
the medical school developed as it did and what features are distinctive or
typical about the school during this period.
PMID- 10685718
TI - ERISA litigation and physician autonomy.
AB - The Employee Retirement Income Security Act (ERISA), enacted in 1974 to regulate
pension and health benefit plans, is a complex statute that dominates the managed
care environment. Physicians must understand ERISA's role in the relationship
between themselves and managed care organizations (MCOs), including how it can
influence clinical decision making and physician autonomy. This article describes
ERISA's central provisions and how ERISA influences health care delivery in MCOs.
We analyze ERISA litigation trends in 4 areas: professional liability,
utilization management, state legislative initiatives, and compensation
arrangements. This analysis demonstrates how courts have interpreted ERISA to
limit physician autonomy and subordinate clinical decision making to MCOs' cost
containment decisions. Physicians should support efforts to amend ERISA, thus
allowing greater state regulatory oversight of MCOs and permitting courts to hold
MCOs accountable for their role in medical decision making.
PMID- 10685720
TI - JAMA Patient Page: eye health.
PMID- 10685719
TI - Shaping a positive future for academic medicine at Michigan.
PMID- 10685721
TI - Role of cardiovascular reactivity to mental stress in predicting future
hypertension.
AB - Hypertension (HT) has been known since times immemorial to be one of the major
causes of morbidity and mortality. It contributes to atherosclerotic
cardiovascular disease, increasing its risk 2-3 times and is also associated with
dyslipidemia, insulin resistance, glucose intolerance and obesity (1). The age of
onset of hypertension is now earlier than before, making it essential that early
detection of people who could be future hypertensives is done. Therefore,
cardiovascular reactivity to stress in predicting future hypertension becomes
important. In this fast paced age most people are exposed to mental stress which
is the most common and prevalent form of stress. Increase in blood pressure (BP)
in response to emotional arousal is well known, but support for this hypothesis
of reactivity in predicting future hypertension is limited. We are attempting
here to put forth a review of the various endeavours done so far to support this
hypothesis.
PMID- 10685722
TI - Efficacy and safety of a fixed low-dose perindopril/indapamide combination in
essential hypertension. A randomised controlled study.
AB - This multicenter, double-blind, parallel-group study was designed to assess the
efficacy and the safety of fixed low dose combination perindopril 2 mg/indapamide
0.625 mg (Per/Ind) versus atenolol 50 mg (Ate). After a 4-week placebo run-in,
446 hypertensive patients (mean age : 55.8 +/- 11.0 years) were randomised to
receive Per/Ind or Ate for 12 weeks. The primary outcome measures were the
changes in trough supine systolic and diastolic blood pressure (sSBP, sDBP)
between baseline and the last observation. Equivalence was assessed in an
intention-to-treat analysis using a two one-sided tests procedure. Per/Ind and
Ate decreased sSBP by -20.5 mmHg and -20.1 mmHg, respectively; the 90% confidence
interval [-2.3; 1.5] of the intertreatment difference (-0.4 mmHg) fell within the
predefined equivalence interval [-8; +8 mmHg]. Similarly, the sDBP decreased by
15.1 mmHg (Per/Ind) and -16.2 mmHg (Ate) with an intertreatment difference of 1.1
mmHg whose 90% confidence interval [-0.1; 2.2 mmHg] fell within the predefined
equivalence interval [-4; +4 mmHg]; thus antihypertensive efficacy of Per/Ind and
Ate were equivalent (P <0.001). In patients older than 65, Per/Ind induces a
statistically greater decrease in sSBP than Ate (P <0.05). Per/Ind was well
tolerated. Further controlled studies are needed to confirm these results on a
long-term period.
PMID- 10685723
TI - Gender differences in growth of vascular smooth muscle cells isolated from
hypertensive and normotensive rats.
AB - Higher male sensitivity to atherosclerotic and hypertensive events was a reason
to study sex differences in migration and proliferation of vascular smooth muscle
cells (VSMC) isolated from male and female spontaneously hypertensive rats (SHR)
and Wistar-Kyoto (WKY) controls. Outgrowth of cells from explants, doubling time,
curves of cumulative labeling and the length of cell cycle were measured in
aortic VSMC. Systolic and mean arterial pressures were higher in males than in
females of the two strains. The migration of cells from male explants was
significantly faster than those from female aortas in both strains. The doubling
time was always shorter in male VSMC than in those from females and this was more
apparent in the late exponential phase of growth. The thymidine incorporation
into newly synthesized DNA, which was enhanced in SHR compared to WKY cells, was
also higher in male cells compared to female ones. Cell cycle was always shorter
in male than in female VSMC due to the shorter G1 phase. In contrast, shorter S
phase caused shorter cell cycle in SHR compared to WKY VSMC. Consequently, the
shortest cell cycle was found in VSMC from SHR males with the highest blood
pressure. It can be concluded that gender and genotype are two independent
factors participating in the control of migration and proliferation of VSMC.
PMID- 10685724
TI - Effects of a neutral endoprotease enzyme inhibitor, thiorphan, on hemodynamics
and renal excretory function in four models of experimental hypertension.
AB - Thiorphan, a neutral endoprotease (NEP) enzyme inhibitor, has been shown to
enhance the effects of atrial natriuretic peptide (ANP) in vivo. In this study,
we examined the effects of an intravenous (iv) infusion of thiorphan on
cardiovascular hemodynamics and excretion of urine volume (UV), sodium (U(Na)V)
and potassium (UKV) in four different models of experimental hypertension,
namely: 1) SHR, 2) two-kidney, one clip (2K1C),3) one-kidney, 1 clip (1K1C) and.
4) 70% reduced renal mass-salt (RRM-S) hypertensive rats. SHR has normal plasma
renin activity, 2K1C is renin dependent, and 1K1C and RRM-S are low renin volume
dependent models of hypertension. Rats were divided into experimental and control
groups. Under inactin (120 mg/kg, body weight) anesthesia, rats were instrumented
to record blood pressure and dP/dt (Millar catheter) and urine was collected
through a suprapubic urinary bladder catheter. Experimental animals received an
iv infusion of thiorphan, 0.5 mg/kg/min for 120 minutes. Control animals received
vehicle only. In some animals, vascular smooth muscle cell membrane potentials
(Em) was measured in vivo. In another series of experiments, using the identical
protocol, cardiac output was recorded. The thiorphan infusion produced a similar
progressive decrease in blood pressure in all models of hypertension. Cardiac
output did not change relative to vehicle infused control animals. Thus pressure
decreased because of a decrease in total peripheral resistance. The contractility
index (dP/dt/P, where P = left ventricular pressure) did not change but vascular
smooth muscle cells in tail arteries hyperpolarized in all four models. In spite
of a significant decrease in blood pressure, thiorphan infusion either increased
or produced no change in urinary volume (UV) and sodium (U(Na)V) excretion. These
data show that thiorphan, an NEP inhibitor, decreases the blood pressure of
hypertensive rats due to a decrease in total peripheral resistance, perhaps by
hyperpolarizing vascular smooth muscle cells. These effects are independent of
the mechanism of the hypertension. Increased UV and U(Na)V in the face of
decreased pressure suggests a direct renal effect.
PMID- 10685725
TI - Pressor responses to serotonin injected into the nucleus tractus solitarius of
Sprague-Dawley rats and spontaneously hypertensive rats.
AB - Previous studies in rats have shown that injection of nanomoles of serotonin (5
hydroxytryptamine; 5HT) into the nucleus tractus solitarius (NTS) acts on 5HT3
receptors to increase arterial pressure (AP). We investigated the effect of 5HT
in Sprague-Dawley (SD) rats and in spontaneously hypertensive rats (SHR).
Injection of nanomoles of 5HT into the NTS of chloralose-anesthetized SD rats
increased AP. This effect was inhibited by prior injection of 5HT3 receptor
antagonist ondansetron. The GABA(A) receptor antagonist bicuculline did not
inhibit the effect of 5HT. Bilateral injection of 5HT or ondansetron did not
affect the baroreflex sensitivity. Bilateral injection of ondansetron did not
alter AP. The pressor effect of 5HT was exaggerated in SHR. These results suggest
that stimulation of 5HT3 receptors in the NTS increases AP independently of
activation of GABAA receptors and the baroreflex sensitivity. Furthermore, this
serotonergic system is supersensitive in the NTS of SHR.
PMID- 10685726
TI - Increased arginase activity in aorta of mineralocorticoid-salt hypertensive rats.
AB - The present study was designed, first to investigate aortic arginase activity
during the development and the establishment of mineralocorticoid-salt (DOCA
salt) hypertension, and second, to determine the relationship between arginase
activity and blood pressure by giving a protein-supplemented diet (50% casein)
known to increase hepatic arginase activity. Our results showed that aortic
arginase activity in established hypertension of DOCA-salt rats was higher than
in normotensive rats. The protein-supplemented diet (50% casein) accelerated the
development of DOCA-salt hypertension. There was a positive correlation between
arginase activity and the level of blood pressure in these DOCA-salt hypertensive
rats fed 50% casein but not in DOCA-salt hypertensive rats on a normal (20%
casein) diet. In normotensive rats, the protein-supplemented diet decreased
aortic arginase activity and produced no change in systolic blood pressure. Our
data suggest that aortic arginase activity is modified in established DOCA-salt
hypertension and could participate in the physiopathology of arterial
hypertension.
PMID- 10685727
TI - Renin-angiotensin-aldosterone system gene polymorphisms and hypertension in Hong
Kong Chinese.
AB - In Chinese populations, hypertension is common and is a major risk factor for
cerebrovascular and coronary heart disease. The renin-angiotensin-aldosterone
system (RAAS) helps maintain blood pressure and salt homeostasis and appears
important in the pathogenesis of hypertension and some forms of vascular disease.
We investigated three RAAS gene polymorphisms, the angiotensin-converting enzyme
(ACE) insertion/deletion, angiotensinogen (AGT) M235T and angiotensin II type 1
receptor A1166C polymorphisms in 232 hypertensive and 178 normotensive Chinese
subjects. The hypertensives were generally more obese and dyslipidaemic. No
significant differences in genotype or allele frequencies for any of the
polymorphisms were identified between the groups, nor was there any interactive
contribution to blood pressure by the ACE and AGT polymorphisms. However, there
were large differences in genotype and allele frequencies between the healthy
Chinese and published data for equivalent Caucasian populations. These findings
suggest these polymorphisms are unlikely to be involved in the pathogenesis of
hypertension in Chinese.
PMID- 10685728
TI - Possible relationship between altered fatty acid composition of serum, platelets,
and aorta and hypertension induced by sugar feeding in rats.
AB - To establish a relationship between alterations in fatty acid metabolism, induced
by sugar ingestion, and hypertension, we analyzed fatty acid composition of
serum, platelets and aorta in rats which had 30% of sugar in their drinking water
for 18-20 weeks, and became hypertensive, hypertriglyceridemic and
hyperinsulinemic. The fatty acid composition in sugar-fed as compared with that
from control rats was as follows: in serum phospholipids, triglycerides and
cholesterol ester fractions, palmitic, palmitoleic, oleic and cis-11
eicosadecaenoic acids were present in a higher proportion. In serum phospholipid
fraction linoleic and arachidonic acids were decreased and a significant increase
was observed in the proportion of dihomo-gamma-linolenic acid. In the membrane
phospholipids of platelets and aorta, higher proportions of palmitoleic and of
oleic acids were observed. Differences in fatty acid composition of phospholipids
between sugar-fed and control rats are consistent with altered membrane fluidity.
Altered membrane function is a potential mechanism involved hypertension in rats
in sugar-induced.
PMID- 10685729
TI - Ovariectomy alters the chronic hemodynamic and sympathetic effects of ethanol in
radiotelemetered female rats.
AB - This study determined the chronic hemodynamic effects of ethanol in telemetered
freely moving female Sprague-Dawley rats. The role of ovarian hormones and
sympathetic activity in the modulation of ethanol responses was also
investigated. Changes in blood pressure (BP), heart rate (HR), and plasma
estrogen and norepinephrine (NE, as index of sympathetic activity) were evaluated
in pair-fed sham-operated (SO) and ovariectomized (OVX) rats receiving liquid
diet with or without ethanol (5%, w/v) for 12 weeks. OVX caused a significant
increase (about 40 g) in body weight, compared with the sham operation, which was
apparent after two weeks and remained so for the duration of the study. The body
weight showed gradual and similar increases in both ethanol and control groups.
Ethanol feeding had no effect on the plasma estrogen level in SO or OVX rats.
Daily ethanol intake was significantly (P < 0.05) less in OVX compared with SO
rats whereas the blood ethanol concentration were similar in the two groups
except for a significantly (P < 0.05) higher level in OVX rats at weeks 8, 10,
and 11. Ethanol feeding caused significant (P < 0.05) decreases in BP in SO rats
that started at week land reached maximal response (approximately 10 mmHg) at
week 6 and remained at that level till the end of week 12. In OVX rats, ethanol
had no effect on BPduring the first 5 weeks of the study. A slight but
significant reduction in BP (about 5 mmHg) by ethanol in OVX rats started to
appear at week 6 and remained for the following 5 weeks. The reduced hypotensive
effect of ethanol in OVX rats was associated with an increase in the sympathetic
activity as indicated by the significant (P < 0.05) increases in plasma NE
levels. This sympathoexcitatory effect of ethanol was not demonstrated in SO
rats. The HR was not affected by ethanol in the two groups of rats except for
significant (P < 0.05) increases at weeks 1 through 3 in SO rats. The present
findings suggest that the ovarian hormones modulate, at least partly, the
hemodynamic and neurohumoral effects of chronic ethanol feeding in female rats.
Ethanol lowers BP in female rats and this effect was delayed and diminished in
OVX rats due possibly to the associated increase in sympathetic activity.
PMID- 10685730
TI - Reflux esophagitis: healed! Now what?
PMID- 10685731
TI - Public and physician education improves participation in colorectal cancer
screening.
PMID- 10685732
TI - Irritable bowel syndrome and health care seeking: do we pass our bad habits onto
our children?
PMID- 10685733
TI - A new weapon for the arsenal in the war against constipation?
PMID- 10685734
TI - Scopes, hopes, and learning the ropes.
PMID- 10685735
TI - Helping patients with Crohn's disease quit smoking.
AB - Smoking is not only a risk factor for Crohn's disease, but ongoing smoking is
associated with a poorer disease course. Therefore, smoking cessation should be
an important treatment strategy for Crohn's disease patients who smoke tobacco.
Recent improvements in understanding how people quit smoking and the development
of pharmacological interventions, such as nicotine patches and bupropion, have
improved cessation rates. In this article, we first briefly review the evidence
supporting the adverse effects of smoking on the disease course. We next review
the current understanding of how people change addictive behaviors, such as
smoking. We then describe how the gastroenterologist can aid the patient with
Crohn's disease to quit smoking, including appropriate and brief counseling
strategies and the use of adjunctive treatments. Given the improvements in
smoking cessation strategies, all patients with Crohn's disease should be
strongly advised to quit smoking and be aided in doing so.
PMID- 10685736
TI - Established and emerging biological activity markers of inflammatory bowel
disease.
AB - Assessment of disease activity in inflammatory bowel disease (IBD), i.e.,
ulcerative colitis (UC) and Crohn's disease (CD), is done using clinical
parameters and various biological disease markers. Ideally, a disease marker
must: be able to identify individuals at risk of a given disorder, be disease
specific, mirror the disease activity and, finally, be easily applicable for
routine clinical purposes. However, no such disease markers have yet been
identified for IBD. In this article, classical disease markers including
erythrocyte sedimentation rate, acute phase proteins (especially orosomucoid and
CRP), leukocyte and platelet counts, albumin, neopterin, and beta2-microglobulin
will be reviewed together with emerging disease markers such as antibodies of the
ANCA/ASCA type, cytokines (e.g., IL-1, IL-2Ralpha, IL-6, IL-8, TNF-alpha, and TNF
alpha receptors) and with various adhesion molecules. It is concluded that none
of the pertinent laboratory surrogate markers of disease activity in IBD are
specific or sensitive enough to replace basic clinical observation such as the
number of daily bowel movements, general well-being, and other parameters in
parallel. Further studies are highly warranted to identify and assess the
clinical importance and applicability of new laboratory markers for the diagnosis
or the disease activity of IBD.
PMID- 10685737
TI - Gastroesophageal reflux disease in the older patient: presentation, treatment,
and complications.
AB - Gastroesophageal reflux disease (GERD) is common in the elderly. Patients often
complain of less severe or frequent heartburn than their younger cohorts, but
because of prolonged acid exposure over many years, the elderly have more
complicated reflux disease including esophagitis, peptic strictures, and
Barrett's esophagus. Potential factors aggravating GERD in the elderly include
medications, which reduce lower esophageal sphincter pressure, higher frequency
of hiatal hernia, impaired motility, and decreased saliva volume and bicarbonate
concentration. Early endoscopy is indicated in all elderly patients with GERD,
regardless of symptom severity. The medical and surgical treatment of GERD in the
elderly generally follows the same principles as for any adult patient.
PMID- 10685738
TI - Selection of patients for successful maintenance treatment of esophagitis with
low-dose omeprazole: use of 24-hour gastric pH monitoring.
AB - OBJECTIVE: Treating patients with erosive esophagitis and maintaining remission
in a cost-effective fashion is a desirable goal in clinical practice. There are
no established criteria to identify patients with healed esophagitis who will
subsequently remain in remission with low-dose omeprazole therapy. We
investigated whether 24-h esophageal-gastric pH monitoring could provide criteria
to select patients for low-dose omeprazole maintenance therapy. METHODS: Seventy
consecutive symptomatic outpatients with grade 2-3 reflux esophagitis were
prospectively investigated. They were treated with 20 mg/day omeprazole for 2
months. Those with healed esophagitis were given alternate-evening 20-mg
omeprazole maintenance therapy for 6 months. Clinical evaluation, endoscopy, and
24-h esophageal-gastric pH were done at the end of each treatment period. Results
of pH studies of patients in remission were compared with those with
endoscopically documented relapse of esophagitis. RESULTS: In 63/70 patient
(intention-to-treat, 90%; 95% confidence interval [CI], 83-97%) esophagitis was
healed at 2 months. During the 6-month maintenance period esophagitis remain
healed in 28 (G1) (40%; 95% CI, 29-52%), but recurred in 32 patients (G2). During
healing with omeprazole 20 mg/day the 24-h gastric pH was below 4 for <10% of the
time in 96% of the patients, who subsequently remained in long-term remission
with low-dose maintenance therapy (G1), but not in any patient with recurrence of
esophagitis (G2). The 10% threshold value has a specificity of 1.00 and
sensitivity of 0.96. CONCLUSIONS: The 24-h intragastric pH monitoring during 20
mg/day omeprazole therapy provides criteria by which to preselect patients with
reflux esophagitis who will remain in remission with low-dose omeprazole therapy.
PMID- 10685739
TI - Ultrasonographic evaluation of lansoprazole-induced improvement of submucosal
injury in patients with gastroesophageal reflux.
AB - OBJECTIVE: Endoscopic ultrasonographic (EUS) changes in gastroesophageal reflux
disease (GERD) after treatment with proton pump inhibitor have been poorly
evaluated. We conducted a randomized, double-blind 12-wk clinical trial to
compare the EUS effects of lansoprazole to histamine H2-receptor antagonist
therapy in GERD. METHODS: Seventeen patients with reflux-related symptoms
received 40 mg of famotidine for 6 wk or 30 mg of lansoprazole for 6 wk followed
by 40 mg of famotidine or 30 mg of lansoprazole for another 6 wk, respectively.
Patients underwent EUS before and at 6 and 12 wk after treatment. RESULTS: Before
treatment, a variable degree of wall thickening was noted on EUS in the lower
esophagus, compared with 20 normal subjects. After 6 wk of therapy, esophageal
wall was significantly thicker in the famotidine group compared with the
lansoprazole group (p<0.01). Surprisingly, thickening of esophageal wall and
abnormal architecture were also detected in endoscopically negative reflux
disease. Lansoprazole was superior to famotidine in reducing the thickness of
esophageal wall. CONCLUSIONS: EUS was very useful for evaluation of submucosal
injury in patients with GERD. EUS showed that a 6-wk course of lansoprazole
therapy reduced thickening of esophageal wall, which was resistant to histamine
H2-receptor antagonist therapy. Our results also suggest that inflammatory damage
to the submucosal and muscle layers of the lower esophagus is the underlying
mechanism of heartburn and associated symptoms in patients with endoscopically
negative reflux disease.
PMID- 10685740
TI - Prospective evaluation of the prevalence of gastric Helicobacter pylori infection
in patients with GERD, Barrett's esophagus, Barrett's dysplasia, and Barrett's
adenocarcinoma.
AB - OBJECTIVE: This study was undertaken to prospectively determine the prevalence of
gastric H. pylori infection in Barrett's esophagus and Barrett's complicated by
dysplasia or adenocarcinoma. METHODS: The prevalence of H. pylori was determined
in Barrett's esophagus patients compared to a control population of patients with
gastroesophageal reflux disease (GERD) only. All patients had a minimum of 10
gastric surveillance biopsies obtained. H. pylori colonization was determined
upon the basis of hematoxylin and eosin and use of a modified Giemsa and or
Steiner's silver stain of all gastric biopsy specimens. RESULTS: Two hundred and
eighty-nine Barrett's patients and 217 GERD control patients were included in the
study. H. pylori was found in 95/289 (32.9%) of the Barrett's patients, compared
with 96/217 (44.2%) of the GERD controls (NS). Forty-seven of the Barrett's
patients had low-grade dysplasia/indefinite dysplasia, 14 high-grade dysplasia,
and 20 Barrett's adenocarcinoma. When Barrett's was subgrouped according to
absence of dysplasia, and presence of low-grade dysplasia, high-grade dysplasia,
or adenocarcinoma, H. pylori prevalence was found to be significantly less for
patients with Barrett's high-grade dysplasia (14.3%) and adenocarcinoma (15.0%)
versus patients with GERD alone (44.2%), Barrett's alone (35.1%), or Barrett's
with low-grade dysplasia (36.2%) (p = 0.016). This difference could not be
explained by differences between Barrett's esophagus patients infected with H.
pylori and those who were not with respect to gender, smoking history, alcohol
consumption, use of proton pump inhibitor, or length of Barrett's mucosa.
CONCLUSIONS: Barrett's high-grade dysplasia and adenocarcinoma are significantly
more prevalent in patients who are not infected with H. pylori. H. pylori appears
to have a protective effect against the development of Barrett's adenocarcinoma.
PMID- 10685741
TI - A cost-effectiveness analysis of prescribing strategies in the management of
gastroesophageal reflux disease.
AB - OBJECTIVE: Patients who have uncomplicated gastroesophageal-reflux disease (GERD)
typically present with heartburn and acid regurgitation. We sought to determine
the cost-effectiveness of H2-receptor antagonists (H2RAs) and proton-pump
inhibitors (PPIs) as first-line empiric therapy for patients with typical
symptoms of GERD. METHODS: Decision analysis comparing costs and benefits of
empirical treatment with H2RAs and PPIs for patients presenting with typical GERD
was employed. The six treatment arms in the model were: 1) Lifestyle therapy,
including antacids; 2) H2RA therapy, with endoscopy performed if no response to
H2RAs; 3) Step up (H2RA-PPI) Arm: H2RA followed by PPI therapy in the case of
symptomatic failure; 4) Step down arm: PPI therapy followed by H2RA if
symptomatic response to PPI, and antacid therapy if response to H2RA therapy; 5)
PPI-on-demand therapy: 8 wk of treatment for symptomatic recurrence, with no more
than three courses per year; and 6) PPI-continuous therapy. Measurements were
lifetime costs, quality-adjusted life years (QALYs) gained, and incremental cost
effectiveness. RESULTS: Initial therapy with PPIs followed by on-demand therapy
was the most cost-effective approach, with a cost-effectiveness ratio of $20,934
per QALY gained for patients with moderate to severe GERD symptoms, and $37,923
for patients with mild GERD symptoms. This therapy was also associated with the
greatest gain in discounted QALYs. The PPI-on-demand strategy was more effective
and less costly than the H2RA followed by PPI strategy or the other treatment
arms. The results were not highly sensitive to cost of therapy, QALY adjustment
from GERD symptoms, or the success rate of the lifestyle arm. However, when the
success rate of the PPI-on-demand arm was < or =59%, the H2RA-PPI arm was the
preferred strategy. CONCLUSION: For patients with moderate to severe symptoms of
GERD, initial treatment with PPIs followed by on-demand therapy is a cost
effective approach.
PMID- 10685742
TI - Predictability of dysphagia after laparoscopic nissen fundoplication.
AB - OBJECTIVE: Dysphagia is the most common complication of antireflux surgery.
Temporary dysphagia occurs in addition to persistent dysphagia because of
technical or physiological problems. Temporary dysphagia may be due to the
patient's personal perception or faulty eating habits. The aim of this study was
to investigate the impact of the patient's personality as it relates to temporary
dysphagia and individual impairment. METHODS: Several studies have used the
construct of personality known as "health locus of control" to predict health
related behavior and convalescence after medical or surgical treatments. This
study investigates the predictability of the subjective degree of dysphagia and
its perceived degree of impairment in relation to the health locus of control
after laparoscopic so-called "floppy" Nissen fundoplication in 90 patients.
Several questionnaires and single-item questions were given to the patients
preoperatively, and 1 wk, 6 wk, and 3 months after surgery. The answers to the
questions provided the data for this study. RESULTS: Preoperatively, 92% of the
patients had no dysphagia and 8% had a mild subjective degree of dysphagia.
Temporary postoperative dysphagia was found in approximately 50% of the patients
1 wk after surgery. The intensity of the dysphagia ranged among mild (18%),
moderate (15%), and severe (16%). Three months postoperatively about 80% had no
dysphagia and only 2% severe dysphagia. Correlations between the construct of
personality and the intensity of postoperative dysphagia and its impairment
revealed a significant relationship at all times. Patients with high expectations
for their own health-related abilities (internal control) had less dysphagia (r =
-0.78 after 1 wk [p<0.001], r = -0.71 after 6 wk [p<0.001], and r = -0.64 after 3
months [p<0.001]), compared with patients who believed that their convalescence
depended more on luck, chance, or fate (external control) (r = 0.67 after 1 wk
[p<0.01], r = 0.72 after 6 wk [p<0.001], and r = 0.63 after 3 months [p<0.01]).
These results are highly significant. The correlation between health locus of
control the degree of a subjective impairment from perceived dysphagia showed
similar results (p<0.01). CONCLUSIONS: The subjective degree of dysphagia and the
perceived impairment as a result of laparoscopic antireflux surgery can be
predicted according to the personality of the patient. Those patients with low
expectations for their own abilities can be identified before surgery, thereby
allowing adaptation techniques to be applied that could improve the results and
well-being of patients after antireflux surgery.
PMID- 10685743
TI - Gastrointestinal bleeding in patients with hereditary hemorrhagic telangiectasia.
AB - OBJECTIVE: Gastrointestinal bleeding occurs in a number of patients with
hereditary hemorrhagic telangiectasia (HHT) and may lead to a high transfusion
need. The aim of this study was to estimate the occurrence and severity of
gastrointestinal bleeding in a geographically well defined HHT population.
METHODS: All HHT families in the county of Fyn, Denmark, (470,000 population)
have been identified. Probands and their first degree relatives, and all
descendants from probands for whom one parent had HHT were eligible for inclusion
in the study. A total of 77 patients with HHT were identified; of these, 76
patients (mean age: 52 yr) were evaluated and interviewed with regard to
gastrointestinal bleeding, that is, a history of either hematemesis or melena.
Patients charts were reviewed. RESULTS: A total of 25 HHT patients (33%) had a
history of either hematemesis or melena. Of these, 12 (48%) had received blood
transfusions. Seven patients had severe bleeding (that is, > or =6 units of blood
within 6 months before inclusion in the study). Endoscopy had been performed in
16 of the 25 (64%) patients. Telangiectatic lesions were documented in nine at
upper endoscopy and in one at sigmoidoscopy. Telangiectatic lesions were observed
in all patients with severe bleeding, but in two patients epistaxis is likely to
have contributed to the anemia. Among 51 HHT patients without a history of
gastrointestinal bleeding, only five (10%) had previously received blood
transfusions; however, none fulfilled the definition of severe bleeding. In the
HHT population 29 patients were > or =60 yr old, but all patients with severe
bleeding were > or =60 yr. CONCLUSIONS: A history of gastrointestinal bleeding is
common in patients with HHT (33%). This study documents that 25% of HHT patients
> or =60 yr suffer from severe gastrointestinal bleeding.
PMID- 10685744
TI - Effects of postprandial walking on delayed gastric emptying and intragastric meal
distribution in longstanding diabetics.
AB - OBJECTIVE: We investigated the influence of standardized postprandial walking on
the rates of gastric emptying and of intragastric meal distribution in 50
consecutive patients with longstanding insulin-dependent diabetes mellitus.
METHODS: Gastric emptying of a semisolid meal labeled with 99mTc was continuously
recorded with a dual-head gamma camera with patients in the supine position for
90 min before and 20 min after a 30-min postprandial walk. Regions of interest
enclosing total stomach, and proximal and distal gastric compartments were
calculated to determine gastric emptying rates and intragastric meal
distribution. RESULTS: The evaluation of gastric emptying rates before and after
postprandial walking demonstrated two variants of delayed gastric emptying: one
variant that was counteracted by postprandial walking in seven patients (14%,
Group I) and another variant that was not influenced by postprandial walking in
11 patients (22%, Group II). In addition, the emptying rates of 28 patients (56%)
were within the range of controls and in four patients the emptying was
accelerated (8%). The filling of the proximal gastric compartment was predominant
and remained dominant after walking in Groups I and II. In controls and in
diabetics with normal gastric emptying, the preliminary predominant filling of
the proximal compartment was equalized after walking and the proximal compartment
regained predominance thereafter. The changes in gastric emptying characteristics
from delayed to accelerated gastric emptying may be related to the duration of
diabetes (r = -0.47, p<0.03) and were not indicated by symptoms of upper GI
discomfort or by secondary diabetic manifestations. CONCLUSION: Postprandial
walking may improve gastric emptying in 14% of patients with longstanding insulin
dependent diabetes mellitus.
PMID- 10685745
TI - Enhanced postprandial gastric myoelectrical activity after moderate-intensity
exercise.
AB - OBJECTIVE: The aim of this study was to investigate the change of postprandial
gastric myoelectrical activity and its relation with vagal activity after
exercise. METHODS: Nine subjects were studied in two sessions. In the control
session, gastric myoelectrical activity was recorded using electrogastrography
(EGG) for 30 min in the fasting state and 60 min after a test meal. In the
exercise session, after the baseline recording of both the EGG and
electrocardiogram (ECG), the subject was put on a cycle ergometer for exercise
until reaching 50% of the maximum age-predicted heart rate for 10 min. The test
meal was then given and the recording was resumed for 60 more minutes. Spectral
analyses were performed on both the EGG and the heart rate variability derived
from the ECG. RESULTS: The postprandial increment of the dominant power (p<0.05)
and the percentage of the 2-4 cpm slow waves (p = 0.01) were significantly higher
with exercise. The standard deviation of the postprandial dominant frequency was
significantly decreased (more stable slow waves) with exercise (p<0.04). While
cardiac vagal activity was significantly decreased after the meal, exercise did
not significantly affect the postprandial change. CONCLUSIONS: Gastric slow waves
become more regular, more stable, and of higher amplitude after exercise, and
this enhancement is probably not mediated via the vagal pathway.
PMID- 10685746
TI - Malignant perihilar biliary obstruction: magnetic resonance
cholangiopancreatographic findings.
AB - OBJECTIVE: We studied the efficacy of magnetic resonance cholangiopancreatography
(MRCP) in the evaluation of malignant perihilar biliary obstructions, with
reference to endoscopic retrograde cholangiopancreatography (ERCP). METHODS: A
total of 40 patients with malignant perihilar biliary obstructions, who underwent
both MRCP (Magnetom Vision; Siemens, Erlangen, Germany; projection technique and
multislice plus maximum intensity projection) and ERCP examinations, were
studied. The study group included hilar cholangiocarcinoma (Klatskin tumor) in 26
patients, icteric hepatocellular carcinoma in four patients, gallbladder
carcinoma in five patients, and metastasis from other than hepatobiliary origin
in five patients. Axial and coronal magnetic resonance (MR) images were added
simultaneously to the MRCP. The mean serum bilirubin level on admission was 11.5
mg/ml (range, 2.8-28.5 mg/ml). The presence and extent of malignant biliary
obstruction were determined with both MRCP and ERCP following the known criteria:
an abrupt and irregular character of a distal narrow segment, a proportionally
dilated biliary tree proximally, and an irregularly shaped intraluminal filling
defect. The efficacy of the MRCP examination in detecting the presence of biliary
obstruction, its anatomical extent, and the underlying cause, respectively, was
compared to that of ERCP. RESULTS: MRCP examination was successfully performed on
all patients, whereas ERCP examination was unsuccessful in two patients. Both
MRCP and ERCP were very effective in detecting the presence of biliary
obstructions (40 of 40 vs. 38 of 38, p = 1.0). MRCP was superior in its
investigation of anatomical extent (34 of 40 vs. 24 of 38, p = 0.015) and the
cause of the jaundice (31 of 40 vs. 22 of 38, p = 0.023) compared to ERCP.
Specifically, the performance of MRCP is promising for the interpretation of
cholangiocarcinoma (22 of 26) and gallbladder carcinoma (five of five), but is
relatively ineffective for the interpretation of icteric HCC (two of four) and
metastasis (two of five). CONCLUSION: MRCP represented an ideal noninvasive
diagnostic tool for the evaluation of malignant perihilar biliary obstructions
with reference to ERCP.
PMID- 10685747
TI - Outcome after surgical resection of intraductal papillary and mucinous tumors of
the pancreas.
AB - OBJECTIVE: Treatment of intraductal papillary and mucinous tumors of pancreas
(IPMT) usually requires surgery. The objective of this study was to evaluate the
risk of recurrence in patients after surgery according to the histological nature
of the neoplasm and the type of surgery. METHODS: The outcome of 45 patients who
underwent partial pancreatectomy (n = 35) or total pancreatectomy (n = 10) for
IPMT was studied according to the nature of the neoplasm (invasive carcinoma or
noninvasive neoplasm), type of surgery (partial or total pancreatectomy), and
lymph nodes status. RESULTS: The overall 3-yr actuarial survival rate was 83%.
Death occurred in seven of 20 (35%) patients with invasive carcinoma and in one
of 26 (4%) patients with noninvasive tumors (p<0.05). There were two recurrences
in the seven patients with noninvasive neoplasm who underwent partial
pancreatectomy with involved resection margins, and none in the 13 patients with
disease-free margins. In patients with invasive carcinoma, there was one
recurrence after total pancreatectomy, six after partial pancreatectomy with
disease-free margins and six after partial pancreatectomy with involved margins.
In patients with invasive carcinoma, total pancreatectomy and the absence of
lymph nodes involvement were independently associated with a low risk of
recurrence. CONCLUSIONS: IPMT may be managed as follows: 1) in patients with
noninvasive neoplasms, partial pancreatic resection should be guided by frozen
section examination until disease-free margins are obtained; and 2) in patients
with invasive carcinoma, total pancreatectomy seems most likely to cure the
patient, but should be discussed according to the general status and the age.
PMID- 10685748
TI - A randomized, placebo-controlled, multicenter study of the safety and efficacy of
a new polyethylene glycol laxative.
AB - OBJECTIVE: This study was designed to determine the efficacy and safety of a new
laxative, Braintree polyethylene glycol (PEG) laxative (Miralax, Braintree
Laboratories, Braintree, MA). METHODS: This investigation was designed as a
placebo-controlled, blinded, randomized, multicenter parallel trial. Study
subjects were constipated but otherwise healthy outpatients who had < or =2
stools during a 7-day qualification period. Braintree PEG laxative 17 g or
dextrose placebo p.o. in 8 oz of water for a 14-day treatment period. A diary
recorded each bowel movement and subjective symptoms of stool consistency, ease
of passage, cramps, and flatus. CBC, blood chemistries and urinalysis were
performed before and after the treatment period. RESULTS: There were 151
randomized subjects, 131 female and 20 male. An increase in bowel movement
frequency was observed with the PEG laxative as compared to placebo (p<0.001),
with the greatest difference in efficacy in wk 2 of treatment (p<0.001). By wk 2
of treatment, on average, placebo subjects had 2.7 bowel movements/wk and PEG
treated study subjects had 4.5 movements/wk (p<0.01), or more than one bowel
movement every 2 days. Investigator (p<0.005) and patient (p<0.001) subjective
assessment of perception of treatment effectiveness, and patient evaluations of
stool consistency and passage showed significant improvement in the active
treatment group (p<0.001). There were no significant differences in laboratory
changes or adverse experiences recorded between groups. CONCLUSION: Braintree PEG
laxative is safe and effective in the short term for the treatment of
constipation.
PMID- 10685749
TI - Intergenerational transmission of gastrointestinal illness behavior.
AB - OBJECTIVE: Previous research, based on retrospective reporting, suggests that
parental reinforcement and modeling may be important mechanisms in the
development of gastrointestinal illness behavior in children and adults. The aim
of this study was to determine the relationship between the illness behavior of
parents, in the form of health care use for irritable bowel symptoms, and the
illness behavior of their children, without relying on retrospective recall.
METHODS: A comparison of two matched groups was made. Groups included 631
children of parents who were diagnosed with irritable bowel syndrome during 1
calendar yr and 646 children of parents matched by parental age, gender, and
number of children in the family who did not receive an IBS diagnosis during the
same 1 yr. Health care use and costs over a 3-yr calendar period for all children
and their parents collected from the health care database of a large health
maintenance organization were evaluated. RESULTS: Case children had significantly
more ambulatory care visits for all causes (mean 12.26 vs. 9.81, p = 0.0001) and
more ambulatory visits for gastrointestinal symptoms (0.35 vs. 0.18, p = 0.0001).
Outpatient health care costs over the 3-yr period were also significantly higher
for case than control children ($1979 vs. $1546, p = 0.0001). Controlling for the
total number of ambulatory visits of the parents, excluding gastrointestinal
visits, did not alter the findings. Gender of the IBS parent was not related to
children's gastrointestinal visits. CONCLUSION: This study extends previous
research by showing that specific types of illness behavior may be learned
through modeling.
PMID- 10685750
TI - Declining prevalence of opportunistic gastrointestinal disease in the era of
combination antiretroviral therapy.
AB - OBJECTIVE: Opportunistic disorders (OD) are the most frequent GI manifestations
of the acquired immunodeficiency syndrome (AIDS). Since the introduction of
highly active antiretroviral therapy (HAART), there appears to be have been a
reduction in the incidence of many of these OD; however, the effect of HAART on
the prevalence of GI OD has not been well studied. METHODS: From 4/95 through
3/98, all HIV (HIV)-infected patients undergoing GI endoscopy were prospectively
identified; mucosal biopsies were obtained in a standardized fashion and
histological specimens were examined by a single GI pathologist. Patients were
divided into three groups based on the time of evaluation: group I: 4/95 to 3/96;
group II: 4/96 to 3/97; and group III: 4/97 to 3/98. RESULTS: A total of 166
patients (90% men; mean age 36+/-10 yr; median CD4 lymphocyte count 62
cells/microl, range 2-884, median viral RNA level 1,357 copies/ml, range
undetectable to 7,721,715) underwent 279 upper and/or lower endoscopies during
the study period. There were no statistical differences in patients' demographics
and indications for endoscopy although the CD 4 lymphocyte count was higher in
group III. The percentage of patients receiving HAART at the time of endoscopy
increased from 0% to 57% over the three periods (p<0.01), and the percentage of
patient receiving combination antiretroviral therapy increased from 37% to 82%
over the study period (p<0.01). In contrast, the prevalence of OD decreased from
69% (group I) to 13% (group III) (p<0.01), whereas the prevalence of non-OD,
including a normal endoscopy increased from 31% to 87% (p<0.01). CONCLUSIONS: GI
OD now seem to be an uncommon problem in HIV-infected patients undergoing
endoscopy despite a low CD4 lymphocyte count, and this reduction of OD was
associated with the use of HAART.
PMID- 10685751
TI - The natural history of gluten sensitivity: report of two new celiac disease
patients resulting from a long-term follow-up of nonatrophic, first-degree
relatives.
AB - OBJECTIVE: Early studies revealed that up to 50% of non-atrophic, first-degree
relatives of celiac disease patients exhibit features of gluten sensitivity.
However, whether these features progress to a fully expressed celiac disease
remain partially known. Our aim was to report two new patients resulting from a
prospective, long-term surveillance of relatives who were nonatrophic at initial
assessment. METHODS: After a median time of 86 months (range: 42-102 months) from
the baseline assessment, we re-evaluated 44 first-degree relatives of propositi
who had taken part in family studies and in whom baseline small intestinal
biopsies were normal. At the baseline screening, 21 relatives had positive serum
antigliadin antibodies and/or increased intraepithelial lymphocyte infiltration,
and 23 did not. In addition, 11 of 18 had a celiac-like response to rectal gluten
challenge and 16 of 34 possessed the characteristic HLA DQ2 haplotype (DQA1 0501
DQB1 0201). Re-evaluation was based on celiac-related serology antigliadin (AGA)
and endomysial (EmA) antibodies. EmA-positive subjects underwent intestinal
biopsy. RESULTS: At the end of the study, EmA was positive in only two subjects.
Histological examination revealed flat small bowel mucosa in both. At baseline,
both cases were EmA-negative and no minor histological changes were observed. One
was a woman with positive baseline IgA and IgG AGA and a rectal gluten challenge
with a celiac-like response; the other patient has presented only with a positive
IgG AGA. In both cases, progression was detected in a clinically silent context.
Both new patients had the characteristic HLA DQ2 haplotype. CONCLUSIONS: Our data
suggest the need to re-evaluate relatives who have been negative on initial
screening for celiac disease. Up to now, the progression to severe enteropathy
was only observed in relatives who had presented some evidence of gluten
sensitivity and the characteristic HLA DQ2 haplotype. Longer longitudinal studies
are necessary to obtain definitive conclusions.
PMID- 10685752
TI - The natural history of ulcerative proctitis: a multicenter, retrospective study.
Gruppo di Studio per le Malattie Infiammatorie Intestinali (GSMII).
AB - OBJECTIVE: The aim of this study was to evaluate the clinical features and the
long term evolution of patients with a well defined initial diagnosis of
ulcerative proctitis. METHODS: Patients with an original diagnosis of ulcerative
proctitis who had been seen at any of 13 institutions from 1989 to 1994 were
identified. Data on disease onset and subsequent evolution were recorded. In
addition, 575 patients with more extensive disease, treated in the same centers,
were used as controls. RESULTS: A total of 341 patients satisfied the inclusion
criteria. The percentage of smokers in these patients was slightly lower than in
controls; no differences were found in the other clinical/demographic variables
evaluated. A total of 273 patients entered long term follow-up (mean, 52 months).
Proximal extension of the disease occurred in 74 of them (27.1%). The cumulative
rate of proximal extension and of extension beyond the splenic flexure was 20%
and 4% at 5 yr and 54% and 10% at 10 yr, respectively. The risk of proximal
extension was higher in nonsmokers, in patients with >3 relapses/yr, and in
patients needing systemic steroid or immunosuppressive treatment. Refractory
disease was confirmed as an independent prognostic factor at multivariate
analysis. CONCLUSIONS: Proximal extension of ulcerative proctitis is frequent and
may occur even late after the original diagnosis. However, the risk of extension
beyond the splenic flexure appears to be quite low. Smoking seems to be a
protective factor against proximal extension, whereas refractoriness is a risk
factor for proximal extension of the disease.
PMID- 10685753
TI - Lack of association between smoking and Crohn's disease but the usual association
with ulcerative colitis in Jewish patients in Israel: a multicenter study.
AB - OBJECTIVE: The association between smoking and inflammatory bowel disease (IBD)
is well established, but data in Jewish patients in Israel were discrepant. The
aim of this study was to examine the smoking habits of Jewish IBD patients in
Israel in a large scale, multicenter study. METHODS: Patients with established
IBD aged 18-70 yr were interviewed in relation to smoking and other habits. Two
controls (one clinic and one neighborhood control matched by age, sex, community
group, and education) were sought for each subject. RESULTS: A total of 534
patients (273 ulcerative colitis [UC], and 261 Crohn's disease [CD]), along with
478 clinic controls and 430 neighborhood controls, were interviewed. There was no
significant difference in the smoking habits between CD patients and their
controls. Of patients with CD, 24.5% were current smokers, as compared to 19.9%
of clinic controls and 25.2% of neighborhood controls (NS). The odds ratio for CD
in current smokers was 1.30 (95% confidence interval 0.85-1.99) versus clinic
controls, and 0.96 (0.63-1.46) versus neighborhood controls. There were also no
significant differences in the proportion of ex-smokers between the groups. Only
12.9% of UC patients were current smokers versus 21.9. % Clinic controls, and
26.4% community controls (p<0.005). The proportions of ex-smokers were higher in
UC patients 29.7% versus 25.9%, and 19.5% in their respective controls (p<0.001
vs. community controls). No significant differences were found in the proportions
of never-smokers between IBD patients and controls. All the above trends were
similar in four different parts of the country. The proportion of current smokers
in UC decreased with the extent of disease (19.7% in proctitis, 13.6% in left
sided, and 4.5% in total colitis) (p<0.05). Patients with UC were more likely to
be light smokers(1-10 cigarettes/day), whereas patients with CD were more likely
to be moderate smokers (11-20 cigarettes/day) in comparison to their controls.
CONCLUSIONS: The lack of association between smoking and CD has now been
established in Jewish patients in Israel. The association was found in UC. The
stronger genetic tendency in CD may contribute to this discrepancy.
PMID- 10685754
TI - Crohn's disease: does race matter? The Mid-Atlantic Crohn's Disease Study Group.
AB - OBJECTIVE: The severity of Crohn's disease (CD) has been reported to be greater
in blacks than in whites. This possible disparity may be due, in part, to
differences between these groups in health care utilization and accessibility. To
explore these issues, we conducted a multicenter survey of patients with CD.
METHODS: One-hundred and forty-five blacks with CD, recruited from four teaching
hospitals and five private practices, and identified by medical record review or
ICD-9 code, were enrolled and matched to 407 whites with CD (by age, gender, and
practice type [teaching vs. private practice setting]). Participants were
interviewed regarding medical history, health status, personal health care
practices during the preceding 5 yr, and beliefs regarding health care in the
general population. RESULTS: Blacks and whites were similar with respect to age
of CD onset, lag in time to diagnosis, and number of gastrointestinal (GI)
related hospitalizations and surgeries. Medication usage patterns were also
similar in the two groups. Quality of life, measured by SF-36, was lower in all
categories for blacks, compared with whites. Blacks were more likely to have had
to stop work (p<0.01) and have lost more work days (p<0.01) than were whites.
Whites were more likely to have health insurance and be able to identify a
regular provider than were blacks. Blacks were more likely to report the
following: receiving Medicaid; difficulty affording health care; delaying
appointments due to financial concerns; difficulty traveling to their provider's
office; and experiencing unreasonable delays at their provider's office. After
adjusting for potential confounding variables, we found no differences between
the groups, except for the number of days of work lost because of CD.
CONCLUSIONS: These data suggest that black and white patients have similar
reported disease presentations and course, and contrast with prior reports
suggesting a more severe disease course among black patients. Although the
disease itself appears similar, there were numerous reported differences between
the races in health care utilization practices and in disease impact upon daily
activities. We suggest that apparent disparities in CD according to race are
actually due to social and economic factors, and not to the disease itself.
PMID- 10685755
TI - Upper gastrointestinal bleeding in patients with hepatic cirrhosis: clinical
course and mortality prediction.
AB - OBJECTIVE: We conducted this study to describe the complications and validate the
accuracy of previously reported prognostic indices in predicting the mortality of
cirrhotic patients hospitalized for upper GI bleeding. METHODS: This prospective,
observational study included 111 consecutive hospitalizations of 85 cirrhotic
patients admitted for GI bleeding. Data obtained included intensive care unit
(ICU) admission status, Child-Pugh score, the development of systemic
inflammatory response syndrome (SIRS), organ failure, and inhospital mortality.
The performances of Garden's, Gatta's, and Acute Physiology and Chronic Health
Evaluation (APACHE) II prognostic systems in predicting mortality were assessed.
RESULTS: Patients' mean age was 48.7 yr, and the median APACHE II and Child-Pugh
scores were 17 and 9, respectively. Their ICU admission rate was 71%. Organ
failure developed in 57%, and SIRS in 46% of the patients. Nine patients had
acute respiratory distress syndrome, and three patients had hepatorenal syndrome.
The inhospital mortality was 21%. The APACHE II, Garden's, and Gatta' s predicted
mortality rates were 39%, 24%, and 20%, respectively, and their areas under the
receiver operating characteristic curve (AUC) were 0.78, 0.70, and 0.71,
respectively. The AUC for Child-Pugh score was 0.76. CONCLUSIONS: SIRS and organ
failure develop in many patients with hepatic cirrhosis hospitalized for upper GI
bleeding, and are associated with increased mortality. Although the APACHE II
prognostic system overestimated the mortality of these patients, the receiver
operating characteristic curves did not show significant differences between the
various prognostic systems.
PMID- 10685756
TI - Maintenance hemodialysis decreases serum hepatitis C virus (HCV) RNA levels in
hemodialysis patients with chronic HCV infection.
AB - OBJECTIVE: Hepatitis C virus (HCV) infection is a major complication among
hemodialysis patients the world over. To determine the natural course of HCV
viremic levels in patients on maintenance hemodialysis, we prospectively
quantified the HCV RNA levels in serial blood samples from hemodialysis patients
and compared them with those in nonuremic subjects. METHODS: The population
studied included 98 hemodialysis patients and 228 nonuremic subjects with chronic
HCV infection. HCV RNA was detected by polymerase chain reaction (PCR) and the
levels were determined by branched DNA probe assay. HCV RNA genotypes were
determined by PCR using type-specific primers. RESULTS: HCV RNA levels were
significantly lower in hemodialysis patients (median, 0.4x10(6) genome equivalent
[Meq]/ml) than in nonuremic subjects (median, 3.0 Meq/ml) (p<0.05). HCV of
genotype 1b was prevalent in the hemodialysis patients (81.6%) and nonuremic
subjects (88.6%). HCV RNA levels in 20 hemodialysis patients with genotype 1b
were significantly reduced after each hemodialysis procedure (p<0.05). The 3-yr
prospective observation from 1995 to 1998 showed a significant decrease of HCV
RNA levels in 47 hemodialysis patients with genotype 1b (median, 1.9-0.9 Meq/ml,
p<0.05), whereas levels in 155 nonuremic subjects with genotype 1b did not
decrease (median, 2.6-3.0 Meq/ml). There were no patients or nonuremic subjects
with undetectable HCV RNA by a PCR assay during the observation period.
CONCLUSIONS: These observations suggest that maintenance hemodialysis decreases
the HCV RNA levels in hemodialysis patients with chronic HCV infection, but does
not produce clearance of the viremia.
PMID- 10685757
TI - Cholestatic liver diseases and health-related quality of life.
AB - OBJECTIVE: Symptoms associated with primary biliary cirrhosis (PBC) and primary
sclerosing cholangitis (PSC) negatively affect health-related quality of life
(HRQL). The aim of this study was to measure HRQL in patients with chronic
cholestatic liver diseases and to determine factors associated with more severe
impairment. METHODS: We conducted a cross-sectional study in which we documented
patients' demographic and clinical characteristics, and measured their HRQL using
the Short Form-36 and Chronic Liver Disease Questionnaire. We assessed the
association of HRQL impairment with disease severity (Child's-Pugh class and Mayo
PBC Risk Score) and compared patients' HRQL with those of a healthy population,
and patients with congestive heart failure, chronic obstructive pulmonary
disease, and diabetes. RESULTS: One hundred and four patients with PBC and PSC
participated, of whom 73% were women, with an average age of 55+/-12 yr. Of these
patients, 61% had cirrhosis (37% Child's A, 23% Child's B, and 2% Child's C).
Patients with cholestatic liver disease showed more HRQL impairment than the
healthy population and were similar to patients with other chronic conditions.
Additionally, patients who experienced severe itching showed profound HRQL
impairment. In patients with PBC, Physical Component Summary (PCS) scores of the
SF-36 and Chronic Liver Disease Questionnaire (CLDQ) scores fell from
noncirrhotic to Child's A to Child's B/C and with worsening Mayo PBC Risk Scores.
No other clinicodemographic data were associated with patients' well-being.
CONCLUSIONS: Patients with cholestatic liver disease (PBC and PSC) showed
substantial impairment of HRQL, which is further affected by worsening disease
severity. Disease-specific measures were better able to discriminate patients
with varying severities.
PMID- 10685758
TI - Natural history of cirrhotic patients with small esophageal varices: a
prospective study.
AB - OBJECTIVE: Contrasting data are available on the natural history and bleeding
risk of small esophageal varices. The aim of this prospective study was to
evaluate a large series of consecutive cirrhotics with a first endoscopic
diagnosis of small varices. METHODS: Between 1987 and 1992, 258 patients with
small varices and no previous bleeding were enrolled. Patients were clinically
examined every 6 months and were followed until a first episode of bleeding
and/or death, or until June 1998. None received any treatment to prevent
bleeding. Endoscopies were planned at 18-month intervals. RESULTS: The cumulative
risk of bleeding was low (3% at 2 yr and 8% at 4 yr) and remained low in patients
in whom varices remained small at 2nd endoscopy, whereas it increased
significantly when varices enlarged. The increase of varices appeared to be
rather linear in time: at the 2nd endoscopy varices remained small in 79% of
patients and increased in 21%; at the 3rd endoscopy varices remained small in
55%, whereas at the 4th 33% of patients still had small varices. Clinical and
biochemical data at the 1st and 2nd endoscopy were included in a multiple
logistic regression analysis. Only the increase in Child-Pugh score appeared to
be a significant predictor of enlarged varices; the risk of aggravation increased
by 37.5% for every unit of impairment of the score. CONCLUSIONS: The present
study shows that patients with small varices have a low bleeding risk. An
increase in Child-Pugh score during follow-up suggests enlargement of varices,
thus an increase in bleeding risk. In these patients closer endoscopic
surveillance is recommended.
PMID- 10685759
TI - Education improves colorectal cancer screening by flexible sigmoidoscopy in an
inner city population.
AB - OBJECTIVE: The District of Columbia General Hospital has a flexible sigmoidoscopy
(FS) colorectal cancer screening program. We noted that this program was
underused. The aim of this study was to determine whether education could improve
use of a flexible sigmoidoscopy screening program in an inner city population.
METHODS: Patients undergoing screening FS 5 months before our educational
initiative were compared to patients undergoing screening FS 5 months after
implementation. A 1-month period was allowed for implementation. Procedure logs
and GI charts were reviewed. RESULTS: A total of 121 patients underwent FS
screening during our study period. Of the patients, 97% were African-American;
58% were female; and the average age was 61 yr. A total of 50 patients underwent
FS in the pre-education group, and 71 patients underwent FS after implementation
of our educational initiative. CONCLUSIONS: Education resulted in a 42% increase
in FS screening in this inner city, predominantly African-American population.
Larger scale educational initiatives should be conducted to determine whether
these benefits can persist and can be improved upon.
PMID- 10685760
TI - Study of outcome after targeted intervention for peptic ulcer resistant to acid
suppression therapy.
AB - OBJECTIVE: Different factors might affect outcome in ulcers resistant to
antisecretory therapy. The aim of the study was to define the odds of resistant
ulcers being associated with NSAID use, and/or Helicobacter pylori (H. pylori)
infection, or neither. METHODS: A total of 80 patients with resistant peptic
ulcers were prospectively followed after targeted intervention for a mean follow
up of 39.5+/-6.9 months. RESULTS: NSAID use was involved in 24 cases (14 with and
10 without concomitant H. pylori infection), H. pylori alone was involved in 44,
and 12 patients had neither factor present. Of the NSAID group, resistant ulcers
healed in patients who stopped taking NSAIDs. Those continuing to use NSAIDs (10
of 24; 41.6%) had either persistent ulceration or ulcer complications despite H.
pylori eradication and omeprazole therapy. Of the H. pylori group, infection
eradication induced ulcer remission in most patients, but those with persistent
infection and a small subset of H. pylori eradicated patients (16.6%) had
persistent/recurrent ulceration. Of the 12 refractory patients with neither NSAID
use nor H. pylori infection, three had persistent ulceration but nine were
controlled with antisecretory agents. Other factors (e.g., smoking or acid
hypersecretion) were not associated with final outcome after targeted
intervention of H. pylori infection and NSAID use. CONCLUSIONS: With current
antiulcer therapies, NSAID use is the main, but not the exclusive, factor leading
to intractability and complications in refractory ulcers. In a subset of
resistant ulcers, neither the presence of H. pylori nor use of NSAIDs are
involved. In this study, despite specific therapeutic intervention, 22.5% of
patients with resistant ulcers had continuing ulcer problems.
PMID- 10685761
TI - Stromal eosinophilia in colonic epithelial neoplasms.
AB - OBJECTIVE: The purpose of this retrospective study was to determine the frequency
and intensity of eosinophilic infiltration (or tissue eosinophilia) in the stroma
of colonic adenomas, hyperplastic polyps, and colorectal adenocarcinomas.
Eosinophilic infiltration in various malignancies has been reported but has not
been evaluated in benign colorectal adenomas and hyperplastic polyps. METHODS: We
analyzed 488 colonic neoplasms: 176 tubular adenomas, 55 tubulovillous adenomas,
82 villous adenomas, 15 early carcinomas in polyps, 95 invasive adenocarcinomas,
and 65 hyperplastic polyps for the presence of eosinophilic infiltration. The
eosinophilic infiltration was graded as negative (< or =5%), mild to moderate (>5
40%), or marked (>40%), depending on the percentage of eosinophils relative to
total inflammatory cells in the stroma. RESULTS: Mild to moderate eosinophilia
was noted in 75% of all adenomas. The transitional zone in all cases of invasive
adenocarcinoma (zone between normal tissue and adenocarcinoma) revealed a high
percentage of tissue eosinophilia. There was a striking absence of TE in the
stroma of invasive adenocarcinomas. Only 5% of hyperplastic polyps had any
eosinophilic infiltration. CONCLUSIONS: These data suggest that, in the spectrum
of colonic neoplasms, stromal eosinophilia is most prominent in adenomas and
seems to decrease with progression through the adenoma-carcinoma sequence. The
ramifications of this study may alter management plans and provide some
prognostic information for clinical evaluation.
PMID- 10685762
TI - The cost of hospitalization in Crohn's disease.
AB - OBJECTIVE: The aim of this study was to evaluate the demographics, resource use,
and costs associated with hospitalization of Crohn's disease patients. METHODS:
All patients hospitalized at our institution from 7/1/96 to 6/30/97 with a
primary diagnosis of "Crohn's Disease" were analyzed using a computerized
database. Data are presented "per hospitalization." RESULTS: A total of 175
hospitalizations (147 patients) were identified. Mean patient age was 36.5 yr;
61% were female; 82% Caucasian. Payer mix was most commonly contracted (57%),
commercial (21%), or Medicare (13%). 57% of hospitalizations had a primary
surgical procedure; the remainder were medical. Average length of stay was 8.7
days (surgical, 9.6 days; medical, 7.5 days). The average cost of
hospitalization, excluding physician fees, was $12,528 (surgical, $14,409;
medical, $10,020), whereas average charges were $35,378 (surgical, $46,354;
medical, $20,744), including physician fees, which averaged $7,249 (surgical,
$11,217; medical, $1,959). Mean reimbursements were $21,968 (surgical, $28,946;
medical, $12,666) with average weighted reimbursement rates of 60.17% of hospital
charges, 69.57% of physician fees. The distribution of costs across subcategories
was: Surgery (39.6%), Pharmacy (18.6%), Laboratory (3.8%), Radiology (2.1%),
Pathology (0.8%), Endoscopy (0.3%), and Other Hospital Costs (34.9%). Of the
hospitalizations, 87% included treatment with steroids, 23% with
immunomodulators, and 14% with aminosalicylates; 27% included the administration
of total parenteral nutrition, which accounted for 63% of the total pharmacy
costs. CONCLUSIONS: Surgery accounts for the majority of hospitalizations, nearly
40% of their total costs, and 75% of overall charges and reimbursements. Therapy
that decreases the number of surgical hospitalizations should substantially
reduce inpatient Crohn's disease costs, as well as overall costs.
PMID- 10685763
TI - Trazodone-induced hepatotoxicity: a case report with comments on drug-induced
hepatotoxicity.
AB - Trazodone (Desyrel) is a second-generation, nontricyclic antidepressant that has
been in use in North America since the early 1980s. It has the advantage of being
more sedating and having less anticholinergic side effects than other secondary
amines in the piperazine class, namely, desipramine and nortriptyline. Five
previous cases of trazodone hepatotoxicity have been reported in the literature,
one describing chronic damage and the others, more acute cellular and cholestatic
injury. We describe a case of acute reversible liver injury with the use of
trazodone. This case is unique in that injury occurred after protracted (18
months) drug use and while the patient was on corticosteroids. Moreover, the
diagnosis was confirmed by an inadvertent challenge with trazodone. This case
reports not only a well documented instance of trazodone-induced liver injury,
but also serves as a basis for a brief discussion of mechanisms, clinical
monitoring, and therapy in drug-induced hepatotoxicity.
PMID- 10685764
TI - Duodenal mucosa-associated lymphoid tissue lymphoma: treatment with oral
cyclophosphamide.
AB - Small cell mucosa-associated lymphoid tissue (MALT) lymphomas rarely affect the
duodenum, and optimal treatment has not been defined. The aim of this case series
was to determine the clinical features and outcome of duodenal MALT lymphoma in
four patients (three men, one woman; median age 52 yr) treated with
cyclophosphamide p.o. Initial manifestations were abdominal pain (n = 4),
vomiting (n = 2), and an obstructive syndrome (n = 1). MALT lymphoma was
diagnosed on the basis of endoscopic biopsies. It was localized in the duodenum
in three cases and involved the entire small bowel in one case. Tumor
infiltration was limited to the duodenal wall in one case and was associated with
locoregional lymphadenopathy in three cases. The patients were graded EI (n = 1)
and EII1 (n = 3), respectively, according to the Ann Arbor classification revised
by Musshof. Cyclophosphamide, 100 mg daily, was administered p.o. for 18 months.
Gastroscopy with biopsies, radiography of the small intestine and abdominal CT
(CT) were performed every 6 months. Complete remission was defined by
morphological and histological normalization, and partial remission as
morphological normalization only. Follow-up lasted from 9 to 65 months. Three
patients were in complete remission at 18 months: two relapsed after 2 yr and one
was still in complete remission at 65 months. The patient with 9 months of follow
up was in complete remission at 6 months. The two patients who relapsed did not
complain of symptoms, and no morphological abnormalities were seen. Relapse was
diagnosed on histological grounds. Cyclophosphamide monotherapy p.o. thus seems
well adapted to this slowly progressive disease, but it is unclear whether it
should be resumed in the case of histological relapse or only in the case of
symptomatic relapse. (Am J Gastroenterol 2000;95:536-539. (O 2000 by Am. Coll. of
Gastroenterology)
PMID- 10685765
TI - An endoscopic injection with N-butyl-2-cyanoacrylate used for colonic variceal
bleeding: a case report and review of the literature.
AB - We report a 64-yr-old patient with liver cirrhosis and bleeding esophageal
varices that were obliterated by repeated endoscopic sclerotherapy. Eleven years
later, he developed a massive, life-threatening rectosigmoid variceal hemorrhage.
An endoscopic injection with N-butyl-2-cyanoacrylate (Histoacryl), performed over
the rectosigmoid varices, achieved temporary hemostasis. The etiology,
prevalence, relationship with portal hypertension, diagnosis, and treatment of
colorectal varices are discussed.
PMID- 10685766
TI - Life-threatening gastrointestinal hemorrhage due to juvenile polyposis.
AB - A 14-yr-old, previously healthy boy presented with massive lower GI hemorrhage.
After the routine endoscopic and radiological evaluation, laparotomy and
intraoperative colonoscopy revealed multiple polyps in the colon. A hemicolectomy
was performed because of the severity of hemorrhage. A diagnosis of juvenile
polyposis was made based upon histological findings and the family history. This
is an extremely unusual presentation of juvenile polyposis and has been reported
only once before. The clinical features, diagnosis, and therapeutic options for
juvenile polyposis are discussed. Juvenile polyposis, although a rare condition
in the pediatric population, should be considered in the differential diagnosis
of life-threatening GI hemorrhage.
PMID- 10685767
TI - Stool testing for Helicobacter pylori infection: yet another noninvasive
alternative.
AB - A prospective, multicenter study was performed in 11 European centers to evaluate
the accuracy of stool testing for active Helicobacter pylori (H. pylori)
infection, using the HpSA ELISA antigen assay. The accuracy of this test was
assessed in a large number of patients both before and after treatment by
comparing results with a rigidly defined gold standard consisting of gastric
antral and body biopsies with normal and special stains, as well as culture and
rapid urease testing. The accuracy of the stool test was also compared with the
currently accepted best noninvasive test, the carbon-13 urea breath test. Five
hundred and one treatment naive patients (276 men, mean age 52 yr) were tested
after endoscopy (491 patients had evaluable results). The sensitivity and
specificity of the stool test were 94.1% (the 95% confidence interval was 90.6
96.6%) and 91.8% (87.3-95.1%), respectively. Pretreatment sensitivity and
specificity for breath testing were similar (95.3% [92.2-97.5%] and 97.7% [94.8
99.3%], respectively). One hundred and seven infected patients were reassessed 4
wk after undergoing therapy for H. pylori infection. The posttreatment
sensitivity and specificity of the HpSA assay was also excellent, although the
confidence intervals were significantly wider because of the smaller number of
patients (90% [68.3-98.9%], and 95.3% [88.5-98.7%], respectively). Posttreatment
sensitivity and specificity for urea breath testing were also similar (90% [68.3
98.8%] and 98.9% [93.8-100%], respectively). Intercenter variability of test
results did not reach statistical significance with either testing method. The
authors concluded that HpSA stool testing is a reliable and easy-to-use method
for diagnosing H. pylori infection in both treatment naive and posttreatment
patients that compares well with carbon-13 urea breath testing. They site
specific advantages of the HpSA assay to include: 1) a more simple sampling
method (only one stool specimen is required); 2) the lack of a requirement for
trained personnel at the testing site; and 3) there is no need for expensive
equipment.
PMID- 10685768
TI - The diagnosis of malign biliary obstruction with cholangiography-guided brush
cytology.
PMID- 10685769
TI - Mycophenolate mofetil, Crohn's disease, measles?
PMID- 10685770
TI - Hyperdynamic circulation in liver cirrhosis: no evidence for peripheral
vasodilation detected by ultrasound of the brachial artery.
PMID- 10685771
TI - Effect of cisapride on gastroesophageal reflux disease of children.
PMID- 10685772
TI - Asymptomatic retroperitoneal air after endoscopic sphincterotomy.
PMID- 10685773
TI - Which scope and which technique will enhance the success rate in ERCP for the
Billroth II patient?
PMID- 10685774
TI - Rectus sheath hematoma clinically masquerading as sigmoid diverticulitis.
PMID- 10685775
TI - Breast cancer developed in a male patient with liver cirrhosis bearing
hepatocellular carcinoma.
PMID- 10685776
TI - Troglitazone-associated hepatic failure.
PMID- 10685777
TI - Endoscopic ultrasound and the community hospital.
PMID- 10685778
TI - Fatal hepatitis associated with ranitidine.
PMID- 10685779
TI - Minocycline and fulminant hepatic failure necessitating liver transplantation.
PMID- 10685780
TI - Prevention of hemorrhage from intradiverticular ulcer in the duodenum by
Helicobacter pylori eradication.
PMID- 10685781
TI - Primary hepatic lymphoma and primary biliary cirrhosis.
PMID- 10685782
TI - Garlic oil and Helicobacter pylori infection.
PMID- 10685783
TI - Unsuccessful treatment results in survival of less virulent genotypes of
Helicobacter pylori in Colombian patients.
PMID- 10685784
TI - Parietal cell hyperplasia with deep cystic dilations: a lesion closely mimicking
fundic gland polyps.
PMID- 10685785
TI - Do I need an ANA? Some thoughts about man's best friend and the transmissibility
of lupus.
PMID- 10685786
TI - Does occupational lifting cause hip osteoarthritis?
PMID- 10685787
TI - Yet another linkage reported--what does it mean?
PMID- 10685788
TI - Abnormal fatty acid pattern in rheumatoid arthritis. A rationale for treatment
with marine and botanical lipids.
AB - OBJECTIVE: To assess the fatty acid pattern in plasma and synovial fluid (SF) in
rheumatoid arthritis (RA) and to determine clinical factors related to possible
abnormalities. METHODS: Thirty-nine patients with RA were included. SF samples
were obtained from 9 patients. Disease activity was assessed using the Ritchie
Articular Index and erythrocyte sedimentation rate. Fatty acids were assayed with
gas liquid chromatography. RESULT: Decreased levels of eicosapentaenoic acid (p <
0.0001) and total n3 polyunsaturated fatty acids (p < 0.05) were observed in
plasma and in joint fluid, respectively. An increase of the substrates of delta-5
desaturase (C20:3n6 and C20:2n6) and decrease of their products (C20:4n6 and
C22:4n6) was observed in plasma total lipids and phospholipids. The long chain
mono-unsaturated fatty acids (C20: 1n9, C22: 1n9, C24: ln9) were increased in the
joint fluid and in plasma phospholipids. Patients with active disease showed a
mild decrease of several saturated fatty acids, n3, and n6 polyunsaturated fatty
acids. Minor abnormalities or no changes in fatty acid profile were found related
to use of steroids, nonsteroidal antiinflammatory drugs, and gold salts, or
malnutrition. CONCLUSION: The fatty acid pattern found in RA (decreased levels of
n3 polyunsaturated fatty acids) may explain the beneficial effect of fish oil.
Changes in n6 polyunsaturated fatty acids suggest that delta-5 desaturation is
decreased and this might facilitate the antiinflammatory effect of botanical
lipids in RA.
PMID- 10685789
TI - In vivo blockade of tumor necrosis factor-alpha in patients with rheumatoid
arthritis: longterm effects after repeated infusion of chimeric monoclonal
antibody cA2.
AB - OBJECTIVE: To investigate the longterm consequences of tumor necrosis factor
alpha (TNF-alpha) blockade in patients with rheumatoid arthritis (RA), to compare
changes after repeated infusion of cA2 monoclonal antibody with those occurring
after the initial treatment, and to investigate significant correlations of
cellular or serological changes to the duration of clinical benefit for each
patient. METHODS: A clinical trial testing TNF-alpha monoclonal antibody cA2 in
treatment of RA showed this therapeutic agent is highly effective. A dosage of 1
mg/kg or 10 mg/kg cA2, given in a single infusion, was compared to placebo. After
clinical relapse all patients were (re)treated with 3 or 10 mg/kg cA2. In
parallel to this clinical study, we investigated cellular and molecular changes
induced by in vivo blockade of TNF-alpha. RESULTS: After an initial transient
increase, T lymphocyte counts were not significantly different from starting
values throughout the observation period. Monocyte counts as well as serum
interleukin 6 (IL-6) and soluble intercellular adhesion molecule 1 (sICAM-1)
concentrations remained decreased for several weeks after infusion. After a
repeated infusion, increases in numbers of T cells and decreases in monocytes and
IL-6 and sICAM-1 concentrations were evident again. Changes in cell counts,
however, were smaller, especially in the group initially treated with the low
dose (1 mg/kg), despite a higher retreatment dosage of 3 or 10 mg/kg cA2.
Similarly, in this group decrease of IL-6 and sICAM-1 concentrations was less
pronounced, was delayed to Day 7 after infusion, and lasted for a shorter period
than seen after initial treatment. CONCLUSION: We conclude that in vivo TNF-alpha
blockade leads to prolonged cellular and serological changes. This effect appears
to be less pronounced after repeated infusion of cA2 compared to the initial
treatment, mainly in the low dose group.
PMID- 10685790
TI - A single cell analysis of Fas ligand positive T cells in rheumatoid synovial
fluid.
AB - OBJECTIVE: To investigate the function of Fas ligand (Fas-L) positive T cells in
rheumatoid synovium, we analyzed the T cell receptor (TCR) CDR3 region and
examined the expression of cytokines in both Fas-L+ and Fas-L- single T cells.
METHODS: Synovial fluid (SF) samples were collected from 2 patients with
rheumatoid arthritis. TCR BV8+ T cells were sorted into a 96 well plate at a
density of one cell per well. Expression of Fas-L, interferon-gamma, interleukin
2 (IL-2), IL-4, IL-6, and IL-10 was analyzed by reverse transcription-polymerase
chain reaction and Southern blot and the TCR BV8 junctional region was sequenced.
RESULTS: Twenty-two of 30 TCR BV8+ T cells from Patient 1 and 20 of 43 TCR BV8+ T
cells from Patient 2 were Fas-L+ T cells, while the others were Fas-L-.
Junctional sequence analysis showed the presence of some conserved amino acid
motifs in the CDR3 region (SRQ, GFG, SSG, SGS, LGTSGTL, TLSS) in 13 clones of Fas
L+ T cells from Patient 1, whereas no conserved amino acid motif in Fas-L-T cells
was found. In Patient 2, conserved amino acid motifs (PGQ, GQG, TTWGA) in the
CDR3 region were found in 6 clones of Fas-L+ T cells, while only one was found in
2 clones of Fas-L-cells. In Fas-L+ T cells, 90-93% expressed both IL-2 and IL-10
mRNA. CONCLUSION: Fas-L+ TCR BV8+ T cells revealed the conserved amino acids
motif in the CDR3 region, suggesting that Fas-L+ T cells might expand by antigen
stimulation and play a crucial role as Th0-type T cells in triggering
autoimmunity in rheumatoid synovium.
PMID- 10685791
TI - Association between IgM response to IgG damaged by glyoxidation and disease
activity in rheumatoid arthritis.
AB - OBJECTIVE: To determine the association of serum IgG advanced glycation
endproducts (AGE) and IgM anti-IgG-AGE antibodies with clinical measurements of
rheumatoid arthritis (RA) disease activity. METHODS: The study group consisted of
62 patients with RA and 16 control patients with osteoarthritis. Patient derived
variables included perceived disease activity (10 cm visual analog scale, VAS)
and Health Assessment Questionnaire (HAQ) results. Clinical measures of RA
activity consisted of tender and swollen joint counts and a physician evaluation
of disease activity (by VAS) as well as history of nodules, bone erosions,
Sjogren's syndrome, and vasculitis documented by chart review. Patient sera were
evaluated for glucose, glycosylated hemoglobin, and presence of RF, IgG-AGE and
IgM anti-IgG-AGE. The nitroblue tetrazolium colorimetric and aminophenyl boronic
acid methods were used for measurement of IgG-AGE, along with an ELISA for
measurement of IgM anti-IgG-AGE. RESULTS: Significant correlations were found
between the presence of IgM anti-IgG-AGE and clinical measurements of swollen
joint count and physician VAS. CONCLUSION: IgM anti-IgG-AGE appears to be
associated with clinical measurements of RA activity and represents a new marker
of more active disease in RA.
PMID- 10685792
TI - Divergent effect of cyclosporine on Th1/Th2 type cytokines in patients with
severe, refractory rheumatoid arthritis.
AB - OBJECTIVE: To investigate the effect of cyclosporine on cytokine production,
especially on T helper 1 (Th1) and T helper 2 (Th2) type cytokines, in patients
with rheumatoid arthritis (RA). METHODS: A 16 week randomized, double blind,
placebo controlled study of cyclosporine (2.5 to 4 mg/kg/day) was conducted in 40
patients with severe, refractory RA who had residual inflammation and disability
despite partial responses to prior maximal tolerated dose of methotrexate (MTX; <
15 mg/week) and low dose prednisone (< 10 mg/day). Clinical and laboratory
variables, and circulating levels of interleukin 2 (IL-2), IL-4, IL-10, IL-12,
tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma)
measured by ELISA were compared between patients (cyclosporine group) treated
with cyclosporine plus MTX and those (placebo group) treated with placebo plus
MTX at entry and at 16 weeks. RESULTS: At 16 weeks, the cyclosporine group (n =
17), compared with the placebo group (n = 17), had greater decreases in tender
joints, swollen joints, patient global assessment, patient self-assessed
disability, and C-reactive protein, as well as having more patients with > 20%
improvement. Comparison of circulating cytokines at entry and at 16 weeks showed
significant decreases of IL-2 (median -61 vs 7 pg/ml; p = 0.004) ("+" denotes
increase, "-" denotes decrease), IL-12 (median -313 vs -14 pg/ml; p = 0.002), TNF
alpha (median -55 vs 5 pg/ml; p < 0.001), and IFN-gamma (median -21 vs 5 pg/ml; p
= 0.003), and a significant increase of IL-10 (median 55 vs -12 pg/ml; p < 0.001)
in the cyclosporine group compared with the placebo group. The degree of IL-10
increases correlated strongly with the degree of IL-12 decreases in the
cyclosporine group (r = 0.572, p = 0.016). However, there was no change in
circulating IL-4 between the 2 groups. Within the cyclosporine group, the
improved patients (n = 10) compared to the non-improved patients (n = 7) had a
greater increase in circulating IL-10 (median 172.0 vs 85.2%; p = 0.01). The rate
of increase of IL-10 strongly correlated with the rate of improvement of joint
scores (r = 0.718, p = 0.001) after administration of cyclosporine. CONCLUSION:
Our results suggest that the therapeutic effect of cyclosporine is achieved by
correcting a Th1/Th2 imbalance (a shift of Th1 type to Th2 type), which may be
involved in the pathogenesis of RA; and that circulating IL-10 is useful to
assess the clinical improvements in patients with RA after administration of
cyclosporine.
PMID- 10685793
TI - Rheumatoid synovial fluid contains bioactive leukemia inhibitory factor with
cartilage degrading activity--another target for chondroprotective intervention.
AB - OBJECTIVE: To determine if the procatabolic activity of inflammatory synovial
fluids (SF) from patients with rheumatoid arthritis (RA) could be attenuated by
the cytokine antagonists murine leukemia inhibitory factor (LIF) binding protein
(mLBP) and interleukin 1 receptor antagonist (IL-1ra). METHODS: Pig articular
cartilage explants were cultured in the presence of either 20% v/v rheumatoid
(RA) or osteoarthritic (OA) SF and varying concentrations of either mLBP and/or
IL-1ra. The catabolic activity of the SF and the relative effects of mLBP and/or
IL-1ra were assessed by determining the percentage release of sulfated
glycosaminoglycans from cartilage explants. LIF concentrations were measured by
ELISA. RESULTS: RA SF but not OA SF stimulated release of proteoglycans from pig
cartilage explants in vitro (47.3 +/- 2.2% vs 24.6 +/- 2.0%; p < 0.0001). Murine
LBP at 100 ng/ml and recombinant human (rh) IL-1ra at 5000 ng/ml produced a dose
dependent inhibition of this proteoglycan release (p < 0.0067 and p < 0.0111,
respectively). The RA SF stimulated proteoglycan release was attenuated by mLBP
and rhIL-1ra independently. No additive effect of this attenuation was observed
when maximal inhibitory doses were used in combination. The decrease in
proteoglycan release produced by mLBP correlated significantly with LIF
concentrations in RA SF. CONCLUSION: These findings are consistent with the
concept that IL-1 stimulates cartilage proteoglycan resorption in RA. They also
support the hypothesis that LIF, too, contributes to cartilage proteoglycan
resorption in RA. The residual stimulation not accounted for by IL-1 or LIF
suggests other cytokines may contribute. The role of LIF and related or unrelated
cytokines may need to be taken into account to optimize chondroprotection in RA
and other rheumatic diseases.
PMID- 10685794
TI - Cells expressing dendritic cell markers are present in the rheumatoid nodule.
AB - OBJECTIVE: To determine if dendritic antigen-presenting cells (DC) are present in
rheumatoid nodules, as has been reported in the synovial lesions of rheumatoid
arthritis. METHODS: Nodules (n = 14) were examined with monoclonal antibodies
(Mab) recognizing the DC differentiation/activation markers CD83, CMRF44, and
CMRF56 and an antibody recognizing the CD1a antigen present on epithelial tissue
associated DC. Results. Cells expressing CMRF44 were common in rheumatoid
nodules, comprising 22% of nucleated cells versus 13% in synovial membranes (n =
10). Cells positive for CD1a (5%) and CD83 (2%) were less common. A majority
(86%) of CMRF44 positive cells were also positive for the macrophage marker CD14.
This left a significant minority of putative DC that were single stained with
CMRF44. CONCLUSION: Cells bearing DC markers are as frequent in the rheumatoid
nodule as in the synovial lesions. A majority are "indeterminate" cells that are
CD14 positive but a proportion are single stained putative DC. The lack of
lymphoid collections containing DC and T and B lymphocytes in the nodule suggests
that local presentation of antigen may not occur in the rheumatoid nodule, as is
thought to be the case in synovial membranes containing lymphoid follicles. This
difference could potentially be explained by different states of activation, and
differentiation of DC within the 2 lesions.
PMID- 10685795
TI - Incidence of glenohumeral joint involvement in seropositive rheumatoid arthritis.
A 15 year endpoint study.
AB - OBJECTIVE: To evaluate the incidence of involvement and nature of destruction of
glenohumeral (GH) joints in a prospectively followed cohort of 74 patients with
seropositive and erosive rheumatoid arthritis (RA). METHODS: At the 15 year
followup radiographs of 148 GH joints were evaluated, and the grade of
destruction was assessed by the Larsen method. RESULTS: Erosive involvement
(Larsen grade 2) was observed in 71/148 (48%) GH joints in 41/74 (55%) patients;
30 patients had bilateral and 11 unilateral involvement. The incidence of mild
erosions (Larsen grade 2) was 401148 (27%), and of severe (Larsen 3-5) 31/148
(21%). The 11 most severely involved (Larsen grade 5) joints were seen in 6 (8%)
patients. Erosions were most often (61/71 joints) observed on the superolateral
articular surface of the humerus. Glenoidal involvement was less common (28/71
joints). The Larsen score (0-100) for peripheral joints correlated significantly
with the GH joint Larsen grade on both sides (p < 0.001). CONCLUSION: After 15
years more than half the patients with RA showed definite involvement and 1 in 4
had severe destruction of the GH joint. The greatest destruction was almost
always bilateral.
PMID- 10685796
TI - Synovial adhesions are more important than pannus proliferation in the
pathogenesis of knee joint contracture after immobilization: an experimental
investigation in the rat.
AB - OBJECTIVE: To measure intraarticular pannus proliferation after early and
prolonged joint immobility using an animal model. METHODS: Forty rats underwent
unilateral immobilization of a knee joint with an internal fixator for periods of
2, 4, 8, 16, and 32 weeks. Twenty rats received sham surgery. The knee joints
were harvested and processed for histological examination. The synovial intima
length and the subintimal area were measured on standardized sagittal sections
with image analysis software. The measurements were recorded with regard to their
location (anterior or posterior; superior or inferior). RESULTS: Intra and
interrater reliabilities for all measurements were > 87.9%. The synovial intima
length was smaller in immobilized knees than in controls at all time points. At 4
and 32 weeks, the difference was statistically significant (p < 0.05). The
differences were marked in the posterior synovium, where the intima length of
immobilized knees was significantly smaller than in controls after 4, 8, 16, and
32 weeks of immobilization (p < 0.05). The subintimal area was comparable in
immobilized and control knees at all time points. CONCLUSION: We standardized the
quantification of intraarticular pannus in a joint contracture model after
immobility of up to 32 weeks' duration. This study revealed a significant
decrease in synovial intima length but no change in the subintimal area of
immobilized knees compared with controls. The decrease in synovial intima length
with immobility suggests that adhesions of synovium villi rather than pannus
proliferation are the major pathophysiological changes leading to contracture
after immobility.
PMID- 10685797
TI - Anti-MAM antibodies in rheumatic disease: evidence for a MAM-like superantigen in
rheumatoid arthritis?
AB - OBJECTIVE: Superantigens (SAg) are potent immunomodulatory microbial proteins
that can activate T cells, B cells, natural killer cells, and monocytes and are
known to trigger experimental autoimmune disease. We investigated whether sera
from patients with rheumatic diseases contained elevated antibodies to Mycoplasma
arthritidis mitogen (MAM) or staphylococcal enterotoxins A and B (SEA and SEB).
METHODS: Standard ELISA were used to measure IgG responses to SAg and IgM and IgG
rheumatoid factors and total IgM and IgG levels. Modifications of standard
lymphocyte proliferation assays were used to determine functional consequences of
the observed antibodies. RESULTS: Antibodies to MAM were elevated in sera from
patients with rheumatoid arthritis (RA) compared to sera from patients with
systemic lupus erythematosus, ankylosing spondylitis, psoriatic arthritis,
Reiter's syndrome, or healthy controls. Responses to other SAg were also elevated
in rheumatic disease sera, but the levels were not specific for a given rheumatic
disease. Anti-superantigen antibody levels did not correlate with the presence of
rheumatoid factor. CONCLUSION: The selected elevation of antibodies to MAM in RA
sera suggests that MAM or a MAM-like molecule might be associated with RA,
whereas elevation of antibodies to SEA and SEB in sera from patients with
rheumatic diseases was less specific.
PMID- 10685798
TI - Determinants of health status in fibromyalgia: a comparative study with systemic
lupus erythematosus.
AB - OBJECTIVE: To compare perceived health status in women with fibromyalgia (FM) and
systemic lupus erythematosus (SLE) using the Medical Outcomes Study (MOS) Short
Form Health Survey (SF-36); and to identify determinants of physical and mental
health in each patient group. METHODS: A cross sectional study of 46 women with
FM (mean age 48.13 yrs, SD 9.40) and 59 women with SLE (mean age 42.36 yrs, SD
11.31). Patients with FM were recruited from a rheumatology clinic and a
rheumatology practice, while patients with SLE were recruited from 4 rheumatology
clinics. Clinical examination determined disease activity (by Systemic Lupus
Activity Measure) in SLE and a tender point count was used for FM. Patients
completed questionnaires assessing health status (SF-36), stress (Hassles),
social support (Social Support Questionnaire 6), and coping (Coping Inventory for
Stressful Situations). RESULTS: Patients with FM reported more impairment on the
following SF-36 subscales: physical function (p < 0.001), role physical (p <
0.001), bodily pain (p < 0.001), and vitality (p < 0.001). Physical component
summary scores were also significantly lower (p < 0.001) for the FM group. Four
hierarchical regression analyses were computed to determine factors related to
physical and mental health in each patient group, with the following variables in
the equation: age, income, disease activity (Step 1), hassles (Step 2), emotional
and task coping, and social support (Step 3). Better physical health in FM was
related to higher income (R2 = 0.17, p < 0.05). In the SLE group, better physical
health was associated with younger age, less disease activity, and lower hassles
(R2 = 0.37, p < 0.0001). Worse mental health among women with FM was associated
with more hassles, more emotional coping, and less satisfaction with social
support (R2 = 0.64, p < 0.0001), while lower income, higher hassles, and more
emotional coping were linked to worse mental health in SLE (R2 = 0.46, p <
0.0001). CONCLUSION: Health related quality of life (HRQL) is impaired among
women with FM and SLE, with FM patients reporting greater impairment along
several dimensions. Enhancing the HRQL of patients with FM and SLE requires
targeting specific modifiable psychosocial factors.
PMID- 10685799
TI - The Systemic Lupus International Collaborating Clinics/American College of
Rheumatology (SLICC/ACR) Damage Index for Systemic Lupus Erythematosus
International Comparison.
AB - OBJECTIVE: To compare patients with systemic lupus erythematosus (SLE) from
different centers with respect to demographics and Systemic Lupus International
Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR
DI) scores, and to assess whether the SLICC/ACR DI changed over time, and whether
initial DI scores were related to outcome. METHODS: Members of SLICC completed DI
scores and patient demographics on patients followed in their centers.
Information was provided at 2, 5-10, and > 10 years of followup. Data were
entered on computer and analyzed on SPSS/PC+ and SAS using descriptive statistics
and analysis of variance. RESULTS: Information for 1297 patients within 2 years
of first clinic visit was submitted from 8 centers. There were 1187 women and 110
men with a mean age at diagnosis of SLE of 32 years. Seven hundred sixty-two were
Caucasian, 423 were black, and the remainder were of other races. There were more
blacks in the American centers than in Canadian or European centers. Five centers
provided information for the 3 time periods. The DI increased over time. Ninety
nine patients had died. Higher SLICC/ACR DI scores were documented in patients
who went on to die. CONCLUSION: The SLICC/ACR DI is a valid measure for damage in
SLE.
PMID- 10685800
TI - Accurately describing changes in disease activity in Systemic Lupus
Erythematosus.
AB - OBJECTIVE: To determine whether Systemic Lupus Erythematosus Disease Activity
Index (SLEDAI) scores correlate with the clinician's impression of level of
disease activity. METHODS: In total, 230 patients with SLE followed at the
University of Toronto Lupus Clinic who had 5 visits 3 months apart in 1992-93
were studied. At each visit a standard protocol was completed. A clinician who
did not know the patients or their SLEDAI scores evaluated each patient record
and assigned a clinical activity level. "Flare" was defined by new or increased
therapy for active disease, an expression of concern, or use of the term "flare"
in the physician's notes. The SLEDAI score was calculated from the database.
RESULTS: SLEDAI scores described a range of clinical activity as recognized by
the clinician. Median SLEDAI scores ranged from 2 (inactive disease) to 8
(persistently active or flare). When the clinician assessed the patient to be
improved, the median SLEDAI score decreased by 2. When the clinician assessed
that the patient was experiencing a flare, the SLEDAI score increased by a median
of 4. CONCLUSION: Based on our data we propose the following outcomes for
patients with SLE: flare, an increase in SLEDAI > 3; improvement is a reduction
in SLEDAI of > 3; persistently active disease is change in SLEDAI +/- 3; and
remission a SLEDAI of 0. These outcomes will allow a more complete description of
a patient's response to therapeutic intervention in a responder index.
PMID- 10685801
TI - Complement degradation product C3d in urine: marker of lupus nephritis.
AB - OBJECTIVE: To examine whether serum and urine C3d, a degradation product of C3,
correlate with renal and extrarenal lupus activity. METHODS: Serum and urinary
C3d levels were measured by ELISA in 15 healthy individuals and 24 patients with
systemic lupus erythematosus (SLE) (8 with inactive disease, 7 with active but
nonrenal disease, 9 with active lupus nephritis). Disease activity variables like
serum C3, C4, and anti-dsDNA antibodies were also measured. RESULTS: The median
serum C3d levels were significantly higher (p < 0.01) in patients with active (26
arbitrary units/ml; AU/ml) and inactive SLE (27 AU/ml) compared to healthy
controls (11.25 AU/ml); levels were comparable in patients with active renal and
extrarenal SLE. On the other hand, urine C3d was elevated only in patients with
active SLE; its level was highest in patients with active lupus nephritis (0.87
AU/ml) compared to patients with active extrarenal diseases (0.31 AU/ml; p <
0.05), to patients with inactive lupus nephritis (0.06 AU/ml; p < 0.001), or to
levels in healthy individuals (0.06; p < 0.001). Urine C3d showed stronger
correlation with disease activity score (SLE Disease Activity Index) than serum
C3, C4, anti-dsDNA antibodies, and serum C3d. CONCLUSION: Urine C3d is a good
index of active lupus, particularly lupus nephritis.
PMID- 10685802
TI - Antibodies to thrombomodulin are found in patients with lupus anticoagulant and
unexplained thrombosis.
AB - OBJECTIVE: To test the hypothesis that thrombomodulin (TM) may be a target for
lupus anticoagulant (LAC) antibodies. METHODS: A recombinant soluble form of TM
was produced and used as an antigen for an ELISA to detect antibodies to TM
(TMAB). Sixty-one samples from 58 patients identified by the coagulation
laboratory as having a LAC and 200 patients with unexplained thrombosis were
evaluated along with 201 healthy controls. RESULTS: Eighteen (30%) of the 58
patients with a LAC and 20 (10%) of 200 patients with unexplained thrombosis had
antibodies to TM. Similar antibodies were found in only 4 (2%) of 201 normal
controls. TMAB show selectivity for TM lacking chondroitin sulfate, but do not
otherwise have an immunodominant region. The IgG from 6 patients with TMAB was
purified, and it bound TM in our ELISA. Three of the 6 IgG fractions inhibited
protein C activation 40% to 70% compared to no inhibition in 7 healthy controls.
CONCLUSION: Some patients with LAC and unexplained thrombosis have antibodies to
TM that may arise in response to TM that has been altered and lost its
chondroitin sulfate attachment. Antibodies to TM may be an important risk factor
for inflammation and thrombosis in these patients.
PMID- 10685803
TI - Heterogeneous behavior of anti-beta2-glycoprotein I antibodies on various
commercially available enzyme immunoassay plates coated with beta2-glycoprotein
I.
AB - OBJECTIVE: To evaluate commercially available enzyme immunoassay (EIA) plates for
the measurement of anti-beta2-glycoprotein I autoantibody (anti-beta2-GPI).
METHODS: Sera from 10 patients with the antiphospholipid syndrome, and 3
monoclonal anti-beta2-GPI antibodies established from patients with
antiphospholipid syndrome, were assayed for binding to solid phase beta2-GPI on
20 commercially available plates. RESULTS: Several commercially available EIA
plates were found to be of potential value for the measurement of anti-beta2-GPI
autoantibody. Some plates were unsuitable for anti-beta2-GPI detection, possibly
due to less beta2-GPI on the plates, or to differences in the nature of
conformational changes of beta2-GPI induced by the plates. CONCLUSION:
Differences among EIA plates need to be considered when measuring beta2-GPI
antibodies.
PMID- 10685804
TI - Polymorphisms in CTLA-4 but not tumor necrosis factor-alpha or interleukin 1beta
genes are associated with Wegener's granulomatosis.
AB - OBJECTIVE: The genetic factors predisposing to Wegener's granulomatosis (WG) are
largely unknown. T cells are clearly involved in the disease, as are the
proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin
1beta (IL-1beta). The cytotoxic T lymphocyte associated antigen-4 (CTLA-4)
suppresses antigen-specific immune responses by opposing the CD28 pathway, and is
crucial for a balanced T cell activation. Genetic variations in the TNF-alpha, IL
1beta, and CTLA-4 genes could thus be important in WG. METHODS: Polymorphisms in
the genes coding for TNF-alpha, IL-1beta, and CTLA-4 were analyzed in 32 Swedish
Caucasian patients and 109 ethnically matched controls. Results. A strong
association of Ctla-4 (AT)n microsatellite to WG contrasts to the negative
finding of associations between TNF-alpha NcoI, IL-1beta TaqI restriction
fragment length polymorphism, and WG. The prevalence of the shortest Ctla-4
allele was decreased in patients with WG compared with healthy individuals (p <
0.0001, pc < 0.0016). CONCLUSIONS: This is the first report of a T cell related
gene in association with WG. The Ctla-4 itself, or a gene close to Ctla-4, may
thus contribute to the pathogenesis of WG by allowing an increased T cell
activation by antigen.
PMID- 10685805
TI - Detection of activated complement complex C5b-9 and complement receptor C5a in
skin biopsies of patients with systemic sclerosis (scleroderma).
AB - OBJECTIVE: Upregulated matrix synthesis is a hallmark of systemic sclerosis
(SSc). There are indications that growth factors such as platelet derived growth
factor (PDGF) are involved in proliferative pathways in SSc lesions. As activated
complement releases PDGF from endothelial cells, we searched for activated
complement and the complement receptor for C5a (C5aR) in skin biopsies of
patients with SSc. METHODS: Snap frozen sections of 8 patients with early SSc and
5 patients with longterm SSc were examined. Using monoclonal antibodies against
activated complement complex C5b-9 and the C5aR, skin biopsies derived from both
clinically involved and non-involved skin were examined by APAAP
immunohistochemistry. RESULTS: A pattern of activated complement C5b-9 and the
CSaR could be detected in SSc microvasculature. Eleven of the 13 patients (7/8
patients with early SSc) showed positive staining for C5b-9. The CSaR was
detected in 6 of the 8 patients with early SSc. In 3 patients with longterm
disease, C5aR expression could also be detected in non-involved skin. CONCLUSION:
Activated complement and complement receptors could be detected in early and late
stages of SSc skin lesions. The presence of complement receptors in non-involved
skin may indicate preclinical activation of pathways resulting in growth factor
dependent matrix synthesis.
PMID- 10685806
TI - Urinary mercury levels in patients with autoantibodies to U3-RNP (fibrillarin).
AB - OBJECTIVE: Autoantibodies to the U3 nucleolar ribonucleoprotein (RNP) fibrillarin
occur in some patients with systemic sclerosis (SSc) or other connective tissue
diseases and can be induced in certain mouse strains by injections of mercuric
chloride, perhaps due to antigenic alteration of fibrillarin by mercury (Hg).
Thus, potential occult exposure to Hg was explored in patients with SSc. METHODS:
Urinary Hg levels were measured by cold vapor atomic absorption in 13 patients
with antifibrillarin antibodies (11 with SSc), 39 SSc patients without
antifibrillarin antibodies, and 32 healthy controls. RESULTS: Mean urinary Hg
levels were significantly elevated in the antifibrillarin antibody positive
patients compared to those in other patients with SSc and controls. After
correction for urinary creatinine levels, mean urinary Hg levels remained
significantly different than in the other 2 groups, although Hg levels in all
were still within the normal or "unexposed" range. When patients and controls
with low urinary creatinine levels were excluded from analysis, there were no
significant differences in mean urinary Hg levels among the 3 groups. CONCLUSION:
These findings suggest that further epidemiological and basic research studies of
mercury are warranted in patients with SSc, especially those expressing
antifibrillarin antibodies.
PMID- 10685807
TI - Impaired expression of IgA Fc receptors (CD89) by blood phagocytic cells in
ankylosing spondylitis.
AB - OBJECTIVE: Expression of IgA Fc receptors (CD89, FcalphaR) and their occupancy by
endogenous IgA were studied on blood monocytes and neutrophits to determine if
FcalphaR defects could account for enhanced serum IgA and IgA-IC commonly found
in patients with ankylosing spondylitis (AS). METHODS: Peripheral blood samples
were obtained from 34 patients with AS, 15 patients with rheumatoid arthritis,
and 34 healthy individuals. Cell surface FcalphaR was analyzed using a
quantitative flow cytometry method in which blood cells were stained with anti
FcalphaR monoclonal antibodies recognizing epitopes outside the IgA binding site
and with F(ab')2 fragments of anti-IgA antibodies. Modulation of cell surface
FcalphaR was evaluated after incubation of blood cells at 37 degrees C in absence
of plasma. Biochemical characterization of iodinated FcalphaR molecules was
determined by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel
electrophoresis (SDS-PAGE). RESULTS: FcaR expression was significantly decreased
on monocytes and neutrophils in patients with AS compared to control groups.
FcalphaR levels were inversely correlated with serum IgA, suggesting its negative
regulatory role. Modulation experiments resulted in rapid and higher FcalphaR
upregulation in AS than in controls, indicating that these molecules were
downregulated only at the cell surface. Moreover, analysis of the surface
iodinated FcalphaR molecules by SDS-PAGE revealed higher Mr (60-90 kDa) in AS
than controls (55-75 kDa), also suggesting an altered glycosylation. Analysis of
receptor occupancy revealed high levels of endogenous IgA bound to monocytes and
neutrophils in patients with AS, pointing to a saturation of IgA Fc receptors.
CONCLUSION: We observed impaired expression of FcalphaR in patients with AS that
is characterized by a downregulation process associated with post-translational
alterations and enhanced binding of endogenous IgA. These alterations might lead
to a defective blood clearance by FcalphaR resulting in the enhancement of IgA
and IgA-IC in AS patients. Decreased FcalphaR expression represents a new marker
for this disease.
PMID- 10685808
TI - Rubella virus vaccine associated arthropathy in postpartum immunized women:
influence of preimmunization serologic status on development of joint
manifestations.
AB - OBJECTIVE: To measure preimmunization rubella virus (RV)-specific IgG levels and
to relate these to the development of acute and chronic (persistent or recurrent)
joint manifestations following rubella vaccination. METHODS: Specific IgG was
determined by whole RV enzyme immunoassays (EIA) (Abbott Rubazyme and M33, an in
house method), immunoblot, neutralization domain peptide (BCH-178c) EIA, and
neutralization bioassay in prevaccine samples of 268 RV seronegative women
(Abbott absorbance < 0.999 units) who had received monovalent live attenuated
RA27/3 strain RV vaccine in a clinical trial that recorded joint manifestations.
RESULTS: Of rubella vaccinated women tested for prevaccine antibodies, 21.7% were
actually positive (> or = 10 IU/ml) by M33 EIA, 33.2% had Abbott values > or =
0.250 units, and 47.6% had RV protein-specific antibody (immunoblot), while only
17.6% were positive (> or = 10 IU/ml) by neutralization domain peptide EIA and
12.7% had neutralization titers > or = 1:8. Seropositivity by the various methods
was compared to recorded occurrence of acute and chronic arthropathy (arthralgia
and/or arthritis) after RV vaccination. Relative to women who had no joint
manifestations, prevaccine seropositivity rates for subjects with acute
arthropathy were significantly (p < 0.05) lower in the Abbott test (< 0.250
units), BCH-178c peptide EIA, and neutralization bioassay, while those who also
developed chronic arthropathy had significantly lower prevaccine seropositivity
rates for the Abbott (< 0.250 units) and M33 EIA and neutralization bioassay.
CONCLUSION: Results suggest that risk for arthropathy following RA27/3 rubella
vaccination may be higher in women who have very low prevaccine levels of
antibody, particularly in assays measuring functional (neutralizing) antibodies.
PMID- 10685809
TI - Magnetic resonance imaging guided corticosteroid injection of the sacroiliac
joints in patients with therapy resistant spondyloarthropathy: a pilot study.
AB - OBJECTIVE: To evaluate magnetic resonance imaging (MRI) guided corticosteroid
injections of inflamed sacroiliac (SI) joints in patients with
spondyloarthropathy with therapy resistant sacroiliitis. METHODS: We performed 16
injections in 9 patients on an outpatient basis (6 men, 3 women, mean age at
onset 24.7 +/- 7.5 yrs). All patients had MRI guided injection of 40 mg
triamcinolone acetonide into SI joints using an open 0.2 Tesla unit. Before and 3
months after corticosteroid injection they underwent an MRI examination with a
closed 1.5 Tesla unit. RESULTS: Seven of 9 patients reported subjective
improvement that lasted at least a mean of 10.8 +/- 5.6 months. Subchondral bone
marrow edema on fat suppressed images resolved in 8 patients after corticosteroid
injection. CONCLUSION: MRI guided corticosteroid injection of SI joints appears
to be an effective and safe procedure without exposure to radiation. It is a
useful therapeutic modality, especially in young patients with severe isolated
sacroiliitis.
PMID- 10685810
TI - Epidemiology of chronic disc degeneration and osteoarthritis of the lumbar spine
in Britain and Japan: a comparative study.
AB - OBJECTIVE: To compare the prevalence of spinal osteoarthritis (OA) in Britain and
Japan. METHODS: A total of 206 men and 188 women living in Hertfordshire, UK, and
a total of 100 men and 100 women living in Miyama, Japan, aged 60-79 years were
studied. Participants completed a lifestyle questionnaire, and anteroposterior
and lateral radiographs of the thoracic and lumbar spine were obtained under
standardized conditions. Each lumbar radiograph was graded for osteoarthritic
changes according to the overall Kellgren-Lawrence (K-L) score. Gradings were
also recorded separately for disc narrowing and osteophyte formation. RESULTS:
British subjects were much more likely to have lumbar spine radiographs graded as
K-L grade 4 severity (p = 0.05 in men, p < 0.001 in women). British men displayed
a greater prevalence of disc narrowing (p = 0.08), but less severe osteophytosis
(p = 0.06) than their Japanese counterparts. British women displayed more severe
disc narrowing (p < 0.001) and osteophyte formation (p < 0.001). On multiple
regression analysis, a higher body mass index (BMI) was associated with excess
risk in the British population (OR 1.84, 95% CI 1.12-3.02), but not in the
Japanese population. Differences between countries in K-L severity persisted
after allowing for age and BMI, suggesting that differences in body build could
not fully explain differences in lumbar spine OA in the 2 countries. CONCLUSION:
We found that severe lumbar degenerative disease is more common in the UK than in
a mountain village in Japan, and that differences exist in the prevalence of both
osteophytosis and disc degeneration between the 2 countries.
PMID- 10685811
TI - Occupational lifting is associated with hip osteoarthritis: a Japanese case
control study.
AB - OBJECTIVE: Hip osteoarthritis (OA) is a frequent cause of pain and disability in
Western countries, but the disorder is less common in Japan. A case-control study
in Britain found obesity, hip injury, and occupational lifting to be associated
with hip OA among men and women. However, there are few epidemiological studies
concerning factors associated with hip OA in Japan. We performed a comparable
case-control study of the disorder in Japan, and contrasted the findings with
those from Britain. METHODS: The study was carried out in 2 health districts in
Wakayama Prefecture, Japan. Cases were men and women aged > or = 45 years listed
for total hip arthroplasty due to OA over one year, and who did not have an
established cause of secondary OA (e.g., rheumatoid arthritis, ankylosing
spondylitis). For each case, a control was selected randomly from the general
population and was individually matched to the case for age, sex, and district of
residence. Cases and controls were interviewed with a structured questionnaire
about medical history, physical activity, socioeconomic factors, and occupation.
Measurements were made of height and weight. RESULTS: One hundred fourteen cases
(103 women, 11 men) were compared with 114 controls. We found no relationship
between obesity and hip OA (OR = 1.0, 95% CI 0.5-1.9; highest vs lowest thirds of
distribution of body mass index). There was, however, a statistically significant
association between occupational lifting and hip OA, such that regular lifting of
25 kg in the individual's first job (OR = 3.6, 95% CI 1.3-9.7) or of 50 kg in
their main job (OR = 4.0, 95% CI 1.1-14.2) was associated with increased risk of
hip OA. These associations remained after adjustment for potential confounding
variables. In contrast, those subjects who spent > 2 h each day sitting during
their first job were significantly less likely to have the disorder (crude OR =
0.5, 95% CI 0.3-0.9). This association also remained statistically significant
after adjustment for potential risk factors. CONCLUSION: Our findings support the
hypothesis that occupational physical activity, particularly the lifting of very
heavy loads in the workplace at regular intervals, predisposes to hip OA in both
Britain and Japan. The lack of association between obesity or hand involvement
and hip OA in Japan suggests that the contribution of constitutional and
mechanical risk factors to this disorder might differ in different populations.
However, attention to manual handling in the workplace would appear an important
aspect of preventive strategies against hip OA in Western and Oriental
populations.
PMID- 10685812
TI - Pain and hyperalgesia in osteoarthritis of the hands.
AB - OBJECTIVE: Tissue damage and pain can lead to a change in the stimulus/response
characteristics of the nociceptive system. Hyperalgesia has been described in
experimental pain states and some clinical conditions, but has not been
investigated in osteoarthritis (OA). We sought to establish the presence of
hyperalgesia at the thumb in subjects with OA of the hand and to explore any
relationship between sensitivity to extrinsic stimuli and the experience of
clinical pain. METHODS: Subjects with OA of the hand were divided into groups
according to their pain profile. The sample also included pain-free OA cases and
pain-free controls. Intensity ratings were obtained for each of 3 types of pain:
continuous pain, incident pain, and movement pain. Thermal and mechanical
detection and pain thresholds were measured over the forearm and the
carpometacarpal joint of the thumb. RESULTS: Lower thermal and mechanical pain
thresholds were evident over the thumb relative to forearm in the groups with
persistent pain. Subjects complaining only of incident pain, pain-free OA cases,
and pain-free controls did not exhibit regional differences in sensitivity to
thermal and mechanical stimuli. Increased ratings of continuous pain were
associated with lower thermal and mechanical pain thresholds. Variance in
movement pain ratings was predicted by mechanical forearm pain thresholds.
CONCLUSION: OA in the hands is associated with cutaneous and deep hyperalgesia to
thermal and mechanical stimuli. Increased levels of continuous pain are
associated with more pronounced hyperalgesia. The associations of movement pain
suggest the contribution of central mechanisms in the stimulus/response changes
accompanying movement pain.
PMID- 10685813
TI - Immunomodulatory properties of rumalon, a glycosaminoglycan peptide complex, in
patients with osteoarthritis: activation of T helper cell type 2 cytokines and
antigen-specific IgG4 antigen-specific igG4 antibodies.
AB - OBJECTIVE: To assess the immunogenic properties of the glycosaminoglycan peptide
complex Rumalon, an aqueous extract of bovine cartilage and bone marrow
frequently used in patients with osteoarthritis (OA). METHODS: Sera from 31
patients with OA who had received several series of Rumalon injections (Group 1,
n = 17: before therapy and after one injection series; Group 2, n = 6: after 2-3
injection series; Group 3, n = 4: after 4-8 injection series; Group 4, n = 4:
after 9-18 injection series) were tested by ELISA for antibodies against Rumalon
and its components as well as by a double sandwich ELISA for type 1 [interferon
gamma, interleukin 2 (IL-2)] and type 2 cytokines (IL-4, IL-5, IL-10, IL-13).
RESULTS: After the first injection series antibodies to Rumalon were induced in 7
of the 17 patients that were all negative before therapy. The antibodies were
preferentially of the IgG4 type. IgG4 levels were increased during therapy (ELISA
optical density x 1000 in Group 1: 73.9 +/- 209.5; Group 4: 1354.5 +/- 307.6),
and in Group 4 all patients had developed these antibodies. Upon analysis of
cytokine levels, there was a significant increase in IL-5 (Group 1 before therapy
407.4 +/- 257.1 pg/ml, Groups 3 and 4: 1409.4 +/- 963.1 pg/ml; p < 0.001) and to
a lesser extent of IL-10 during therapy (Group 1 before therapy 950.2 +/- 867.8
pg/ml, Groups 3 and 4: 2817.8 +/- 3127.3 pg/ml; p < 0.05), while type 1 cytokines
were not affected. CONCLUSION: Rumalon appears to have immunomodulatory
properties and preferentially stimulates IgG4 antibodies via the activation of
type 2 cytokines in vivo. Whether these phenomena can be correlated with the
postulated therapeutic effect of Rumalon in patients with OA remains to be seen,
but pain relief via release of endorphins by Th2 cells could be one explanation.
PMID- 10685814
TI - Apoptotic chondrocyte death in human osteoarthritis.
AB - OBJECTIVE: To define apoptotic chondrocyte death and the expression of Bcl-2,
Bax, and Fas in human osteoarthritis (OA) cartilage. METHODS: Cartilage samples
were obtained from patients with knee OA at the time of joint replacement surgery
and from normal autopsy cases. In OA, sections were obtained both from the
lesional area, usually within 1 cm of bony exposure, and from the non-lesional
area, which had macroscopically normal appearance or only mild surface
irregularities. Apoptosis was verified by microscopic examination of hematoxylin
and eosin stained specimens, TUNEL staining, electron microscopy, and DNA ladder
analysis by electrophoresis. Immunohistochemistry was done to study the
expression of Bcl-2, Bax, and Fas. Apoptotic cells and Bcl-2, Bax, and Fas
positive cells were counted within defined microscopic fields. Expression of Bcl
2 and Bax was verified by Western blot. RESULTS: The percentage of apoptotic
cells in the lesional area was significantly higher than in the non-lesional area
in cartilage from the same patient with OA, while apoptotic cells were rarely
seen in normal cartilage. This result was confirmed by TUNEL stain. Many
chondrocytes with chromatin condensation were verified in electron microscopy,
and DNA from OA lesional cartilage revealed a DNA ladder on electrophoresis. Bcl
2 and Fas expressions were significantly higher in the OA lesional area than in
the non-lesional area. On the other hand, Bcl-2 expression in normal cartilage
was significantly higher than in OA cartilage. There was no significant
difference in Bax expression among normal, OA lesional, and OA non-lesional
cartilage. CONCLUSION: These results show that apoptotic chondrocyte death occurs
more frequently in OA compared to normal cartilage and in OA lesional compared to
OA non-lesional cartilage. The different expression patterns of Bcl-2 and Fas in
OA lesional and non-lesional cartilage suggest that they might be involved in the
pathogenesis of OA.
PMID- 10685815
TI - Cell populations involved in pigmented villonodular synovitis of the knee.
AB - OBJECTIVE: Pigmented villonodular synovitis (PVNS) of the knee is a tumor-like
process of uncertain nature. We analyzed the involved cell populations, iron
deposition, and cell proliferation in PVNS to propose a pathogenetic concept of
this still elusive disease entity. METHODS: The study was performed on a series
of 14 cases of localized PVNS of the knee. Histology and histochemistry were used
to evaluate basic morphology and iron deposit distribution. Immunohistochemistry
was performed to characterize the inflammatory cell infiltrate and to identify
the proliferating cell compartments. In situ hybridization analysis using a cDNA
probe against type I collagen was utilized to further characterize the
mononuclear cell infiltrate. RESULTS: In addition to the classic features
(mononuclear cell infiltrate, multinuclear giant cells, iron deposits, and
stromal fibrosis) we observed a chronic inflammatory cell infiltrate in all PVNS
samples, in which CD8 positive T cells were conspicuous. A high portion of non
phagocytotic cells resorbed iron and became CD68 positive. A proportion of
mononuclear cells expressed type I collagen, thus resembling B synoviocytes.
CONCLUSION: Our results suggest that preexisting chronic inflammation plays an
important pathogenetic role in the PVNS disease process. Chronic inflammation
increases the risk of articular bleeding and probably deranges the iron
processing capacity of local synovial macrophages. The resulting iron overload
could lead to a shift of iron storing cells from synovial macrophages to B
synoviocytes and fibroblasts. A perpetuated proliferation and activation of these
cells can explain why PVNS behaves like a neoplastic process.
PMID- 10685816
TI - Familial osteoarthritis and Milwaukee shoulder associated with calcium
pyrophosphate and apatite crystal deposition.
AB - OBJECTIVE: To characterize and define the phenotypes observed in a large Italo
Argentinean kindred with osteoarthritis, chondrocalcinosis, and Milwaukee
shoulder (MS). METHODS: Seventy-five members were evaluated with a history,
examination, and radiographs of shoulders, spine, hands, and knees. Superior
subluxation of the glenohumeral joint was graded using shoulder radiographs and
tomography and nuclear magnetic resonance imaging and 3 dimensional computed
tomography was performed on selected members. In 31 family members peripheral
blood DNA was utilized for genetic linkage analysis of several candidate gene
loci previously linked to chondrocalcinosis phenotypes, as well as those
implicated in the proper patterning of skeletal elements and cartilage
differentiation. In addition, direct sequence analysis of type II collagen gene
(COL2A1), the gene that codes for the major structural protein of cartilage, was
undertaken in 3 affected and 3 unaffected members of the family. RESULTS: MS was
seen in one member of the first generation and 6 members of the 2nd generation,
while 8 members of the 3rd generation showed an incomplete form of MS. Isolated
superior subluxation of the shoulder was seen in 16 other family members of the
3rd and 4th generations. Osteoarthritis of the spine and peripheral joints was
seen in 31 affected members, while chondrocalcinosis was observed in 6 members of
the first generation. Shoulder synovial fluid from 2 patients showed the presence
of both apatite and calcium pyrophosphate dihydrate crystals. Direct analysis of
the COL2A1 gene indicated no known disease determining mutations in affected
members, thus excluding this gene as a candidate gene in this family. Genetic
linkage to several candidate loci, including the chondrocalcinosis loci on
chromosomes 5p and 8q, as well as loci for HOX A and C were also excluded.
Linkage analyses of other loci for the HOX B and D genes and the PAX 1 and 9
genes were uninformative in this kindred. CONCLUSION: This kindred illustrates an
unusual type of osteoarthritis with secondary intraarticular and periarticular
calcification and MS in the most severely affected elderly members. A search for
linkage to some potential candidate genes was either excluded or uninformative.
Further linkage analysis to identify potential candidate genes is in progress.
PMID- 10685817
TI - Treatment of whiplash associated neck pain [corrected] with botulinum toxin-A: a
pilot study.
AB - OBJECTIVE: Up to 87% of patients with whiplash associated disorder (WAD) have
some degree of muscle spasm that is contributory to both pain and dysfunction.
Botulinum toxin A (BTX-A) produces prolonged muscle relaxation that is dose
dependent and can be easily targeted to affected muscles. BTX-A therapy may be an
effective form of therapy offering an alternative or adjunct to conventional
modalities. We investigated BTX-A as therapy in patients with WAD. METHODS: This
randomized, double blind, placebo controlled study compares outcome measures in
26 patients with chronic neck pain (WAD-II chronic) subsequent to a motor vehicle
accident. One-half of the patients received 100 units BTX-A, diluted in 1 ml
saline, while the other half received just saline (1 ml). Five trigger points
received 0.2 ml each of injectant via a 30 gauge needle. Outcome measures
included total subjective neck, shoulder, and head pain based on visual analog
scales; objective total range of neck motion (ROM), and the Vernon-Mior
subjective function index. Followup assessments were carried out at 2 and 4 weeks
post-treatment. RESULTS: Fourteen subjects receiving BTX-A and 12 receiving
saline completed the study. The treatment group showed a trend toward improvement
in ROM and reduction in pain at 2 weeks post-injection. At 4 weeks post-injection
the treatment group was significantly improved from preinjection levels (p <
0.01). The placebo group showed no statistically significant changes at any post
treatment time. The Vernon-Mior scale revealed a trend to improvement for both
groups. CONCLUSION: BTX-A treatment of subjects with chronic WAD II neck pain
resulted in a significant (p < 0.01) improvement in ROM and subjective pain
compared to a placebo group, but only a trend to improvement in subjective
functioning.
PMID- 10685818
TI - Fibromyalgia in men: comparison of clinical features with women.
AB - OBJECTIVE: To describe possible differences between male and female patients with
fibromyalgia syndrome (FM) in their clinical manifestations. METHODS: Five
hundred thirty-six consecutive patients with FM (469 women, 67 men) seen in a
university rheumatology clinic and 36 healthy men without significant pain seen
in the same clinic were included in the study. Data on demographic and clinical
features were gathered by a standard protocol. Tender point examination was
performed by the same physician. Level of significance was set at p < or = 0.01.
RESULTS: Several features were significantly (p < or = 0.01) milder or less
common among men than women, including number of tender points (TP), TP score,
"hurt all over," fatigue, morning fatigue, and irritable bowel syndrome (IBS).
The total number of symptoms was also fewer among men and approached significance
(p = 0.02) by parametric test, but reached significance (p = 0.001) by
nonparametric analysis. All clinical and psychological symptoms as well as TP
were significantly (p < 0.01) more common or greater in male patients with FM
than healthy male controls, with the exception of IBS (p = 0.03). Patient
assessed global severity of illness, Health Assessment Questionnaire disability
score, and pain severity were similar in both sexes. CONCLUSION: Male patients
with FM had fever symptoms and fewer TP, and less common "hurt all over,"
fatigue, morning fatigue, and IBS, compared with female patients. Stepwise
logistic regression showed significant differences between men and women in
number of TP (p < 0.001).
PMID- 10685819
TI - Systemic onset juvenile idiopathic arthritis: a retrospective study of 80
consecutive patients followed for 10 years.
AB - OBJECTIVE: To investigate the relationships between systemic onset juvenile
idiopathic arthritis disease activity, course of the disease, and functional
class according to Steinbrocker. METHODS: The records of all children with
systemic onset juvenile arthritis (JA) according to the American College of
Rheumatology criteria attending our center since 1971 with a minimum followup
period of 3 years were reviewed. A cohort of 80 consecutive patients entered the
study: 42 males, 38 females, mean age at onset 6.3 years (range 0.7-16), mean
followup period 10.7 years (range 3-33). The cumulative duration of the active
periods (CDAP) in months was calculated for every patient. RESULTS: Three
patterns of disease course were apparent: monocyclic (subtype I), intermittent
(subtype II), and persistent (subtype III). At the last control the functional
class and disease activity status were evaluated. In all subtype I patients (9
cases) the disease was in remission and no patient was in class II, III, or IV.
In subtype II patients (27 cases), 16 were inactive or in remission and 6 in
class III. In subtype III (44 cases) 21 were inactive or in remission and 17 were
in class III or IV. The equation relating the Steinbrocker class to the CDAP was
calculated considering the functional outcome as the dependent variable. The
linear regression equation y = 0.0083 x + 1.266 was found with a correlation
coefficient r = 0.586 (p < 0.0001). The majority of our patients were treated
with disease modifying antirheumatic drugs, which in many cases were effective in
reducing the duration of the active phases of disease. CONCLUSION: Systemic onset
JA may present with different clinical courses; the functional outcome is always
good in subtype I (monocyclic), but can be poor in subtypes II and III. The
severity of disability evaluated according to Steinbrocker classes is dependent
on the cumulative duration of the active periods of the disease.
PMID- 10685820
TI - Prominent expression of mRNA for proinflammatory cytokines in synovium in
patients with juvenile rheumatoid arthritis or chronic Lyme arthritis.
AB - OBJECTIVE: To examine the cytokine profiles in synovium of patients with juvenile
rheumatoid arthritis (JRA) or Lyme arthritis, 2 chronic inflammatory arthritides
that affect children. METHODS: We used in situ hybridization with specific
riboprobes to determine the expression of mRNA for proinflammatory or
antiinflammatory cytokines in synovial samples from 5 patients with early,
untreated JRA, 15 patients with late, treated JRA, and 9 patients with chronic
Lyme arthritis. For comparison, synovia were examined from 6 patients with
rheumatoid or psoriatic arthritis, and from 9 patients with various orthopedic
conditions. RESULTS: Among the children with early, untreated JRA, a median of 3
to 8% of inflammatory cells in synovial samples expressed mRNA for the
proinflammatory cytokines interleukin 1beta (IL-1beta), tumor necrosis factor
alpha(TNF-alpha), or interferon-gamma (IFN-gamma). Although a median of 3.9% of
the cells expressed mRNA for the antiinflammatory cytokine IL-10, none had IL-4
mRNA. Most of the patients with late, treated JRA, chronic Lyme arthritis,
rheumatoid, or psoriatic arthritis had mRNA for each of these proinflammatory
cytokines in about 1% of the cells, whereas mRNA for the antiinflammatory
cytokines was less frequent. The inflammatory cell density was much less in the
synovium of patients with various orthopedic conditions, but about 1% of the
infiltrating cells expressed mRNA for at least one of the proinflammatory
cytokines. CONCLUSION: Patients with early or late JRA or chronic Lyme arthritis
have expression of mRNA in synovial tissue primarily for proinflammatory
cytokines, with less expression of antiinflammatory cytokines.
PMID- 10685821
TI - Lipophagic granulomatous panniculitis with lipoatrophy mimicking arthritis with
pitting edema.
AB - We describe a preadolescent girl with intense ankle synovitis and pitting edema
that obscured the subcutaneous origin of the inflammation. Typical nodular
disease emerged after corticosteroid tapering when regional atrophy developed.
PMID- 10685822
TI - A 30 year history of panniculitis.
AB - The differential diagnosis of panniculitis may be challenging due to the uniform
clinical presentation of different panniculitis subsets. We describe a 45-year
old woman with a 30 year history of panniculitis, who had repeatedly failed to
fulfill diagnostic criteria for various panniculitis subsets. Finally, erythema
induratum was diagnosed and she was successfully treated with antituberculous
chemotherapy. The wide spectrum of histological alterations of chronic erythema
induratum as well as the sensitivity of polymerase chain reaction for
Mycobacterium tuberculosis in erythema induratum lesions is discussed.
PMID- 10685823
TI - Acute adrenal crisis in a patient treated with intraarticular steroid therapy.
AB - Intraarticular therapy with corticosteroids can cause systemic effects such as
decreased concentration of plasma cortisol, but whether this might place a
patient at risk from stress induced acute adrenal failure is not known. We
describe a patient who presented with lethargy, hyponatremia, and then with acute
abdomen. The diagnosis of acute adrenal crisis was related to suppression of the
hypothalamic-pituitary-adrenal axis by intraarticular use of corticosteroid. This
was confirmed by a low basal cortisol concentration and by a short Synacthen test
that elicited an increase in plasma cortisol concentration from 36 to 481 nmol/l.
Within 24 h of receiving 37.5 mg of hydrocortisone, the patient rapidly improved.
PMID- 10685824
TI - Sarcoidosis presenting as necrotizing sinus destruction mimicking Wegener's
granulomatosis.
AB - We describe a 26-year-old man who developed nasal stuffiness and palatal
destruction. Biopsy of a mass in the ethmoid sinus confirmed sarcoidosis.
Treatment was initiated with oral steroid and methotrexate, with marked
improvement in his symptoms. Although paranasal sinus involvement in sarcoidosis
is rare it should be considered in differential diagnosis of diseases causing
palatal or paranasal sinus destruction.
PMID- 10685825
TI - Thrombosis associated with the prothrombin G-->A20210 mutation in Behcet's
disease.
AB - We describe 2 cases of Behcet's disease (BD) and thrombosis who were heterozygous
for the prothrombin G-->A20210 mutation. In one case, progressive uncontrolled
thromboses led to death. Case-control studies are needed to support the
hypothesis of the role of the prothrombin A20210 allele as a risk factor for
venous thrombosis in some patients with BD.
PMID- 10685826
TI - The Dunlop-Dottridge Lecture: The pathogenesis of giant cell arteritis.
PMID- 10685827
TI - A review of controlled clinical trials examining the effects of antimalarial
compounds and gold compounds on radiographic progression in rheumatoid arthritis.
AB - At least 8 randomized controlled clinical trials have examined the effects of
chloroquine or hydroxychloroquine on radiographic progression in rheumatoid
arthritis (RA). At least 12 randomized controlled trials have examined the
effects of either intramuscular or oral gold on radiographic progression. A
review of these studies shows that hydroxychloroquine and chloroquine have
minimal, if any, inhibitory effects on radiographically documented progression of
bone erosions and joint destruction when used to treat RA. Intramuscular gold
(with most of the data from studies of sodium aurothiomalate) appears to be
better than placebo, about equal to intramuscular methotrexate (MTX), but
probably not as effective as cyclophosphamide or azathioprine in its effects on
radiographic progression. Auranofin appears to be better than placebo, comparable
to or perhaps moderately less effective than intramuscular gold, comparable to
lower dose oral MTX (7.5 mg/week), and not as effective as higher dose oral MTX
(7.5-15 mg/wk) in inhibiting radiographic progression in RA. The inhibitory
effects of gold compounds on proinflammatory cytokine synthesis (especially
interleukin 1) offer a plausible mechanism for their inhibitory effects on bone
erosion and joint destruction in RA.
PMID- 10685828
TI - Radiographic assessment of disease progression in rheumatoid arthritis patients
treated with methotrexate or minocycline.
AB - Radiographic studies of methotrexate (MTX) treated and minocycline treated
patients with rheumatoid arthritis (RA) are reviewed. A formal metaanalysis of
publications of RA treated with MTX was undertaken at the time when MTX was used
for patients with established RA. Thus the conclusions of that metaanalysis may
not be applicable to patients treated with MTX earlier in the course of their
disease. On the other hand, there are no sufficient data to conduct a formal
metaanalysis of patients with RA treated with minocycline.
PMID- 10685829
TI - Alternative methods for analysis of radiographic damage in a randomized, double
blind, parallel group clinical trial comparing hydroxychloroquine and
sulfasalazine.
AB - Radiographic data of a 48-week double-blind, randomized, parallel trial comparing
hydroxychloroquine (HCQ) and sulfasalazine (SASP) and its open label extension to
3 years of follow-up are analyzed in various ways. The focus of the paper is the
methodological issues involved in analyses of radiographic data in a trial. Both
the traditional method of increase in erosions and total score calculated on a
group level, as well as individual progression on a patient level are presented.
Regardless of which method is used, there is a statistically significant
reduction in radiographic progression in the SASP group compared to the HCQ
group.
PMID- 10685830
TI - On variability of effects for a metaanalysis of rheumatoid arthritis radiographic
progression.
AB - Variance of an outcome that is the topic of a metaanalysis may be estimated in a
variety of ways. Variances are also not used in the same way in every
metaanalysis. The metaanalysis may be of a single measure expressed in its
original units, or of several such measures simultaneously, or it may be done
using unitless effect sizes. We present some observations and practical
recommendations on the estimation and use of variances relating to these several
approaches to metaanalysis, as they may apply in a metaanalysis of radiographic
progression in rheumatoid arthritis.
PMID- 10685831
TI - Issues involved in a metaanalysis of rheumatoid arthritis radiographic
progression. Analysis issues.
AB - Missing data in controlled clinical trials may create uncertainty in the results
of a study based on non-missing data. We used 4 approaches of sensitivity
analysis to address this problem. Radiographic progression data were used from a
randomized controlled trial of patients with rheumatoid arthritis treated with
leflunomide, methotrexate, or placebo for 12 months as an example. The mean
change from baseline of the Sharp total radiographic score was the primary
efficacy variable for the evaluation of leflunomide in comparison with placebo in
the retardation of radiographic progression. Computer simulations were used in
some of these approaches. The proportion of missing radiographic data was 26.4%.
Result from the non-missing data showed that leflunomide was highly statistically
significantly better than placebo in the retardation of radiographic progression.
Results from the sensitivity analysis showed that radiographic data are
sufficiently robust that it is unlikely that the missing data would have changed
the conclusions from the analysis based on non-missing data. The potential effect
of missing data in the results of a clinical trial may be addressed by various
methods of sensitivity analysis. Computer simulation can be a useful tool in some
of these approaches.
PMID- 10685832
TI - Evidence from rheumatoid arthritis trials for approval: what does it mean? With
special reference to using radiographic endpoints.
AB - Since medicine remains largely empirical, clinical knowledge about therapy is
derived primarily from experiments designed to control confounders that use
inferential techniques applied to the null hypothesis model. On a public health
scale, health agencies need to assess the evidentiary weight supplied for new
therapies to make approval decisions. In the field of rheumatoid arthritis (RA),
there are additional analytic challenges such as designation of endpoints or
missing data. The intellectual architecture that underpins these exercises
continues to evolve, and recently the US Food and Drug Administration released an
RA Guidance Document to describe some aspects of these exercises. This article
focuses on the use of measurements of radiographic endpoints in particular as an
element in the evidentiary portrayal of therapeutic efficacy in RA.
PMID- 10685833
TI - Influenza may influence rheumatoid arthritis.
PMID- 10685834
TI - Interleukin 6 reduces serum urate concentrations.
PMID- 10685835
TI - Childhood polyarteritis nodosa presenting as a relapsing movement disorder.
PMID- 10685836
TI - Cyclosporine as a treatment for multicentric reticulohistiocytosis.
PMID- 10685837
TI - Androgen levels of patients with ankylosing spondylitis.
PMID- 10685838
TI - Ultrastructure studies of preadult Proteocephalus longicollis (Cestoda,
Proteocephalidea): transmission electron microscopy of scolex sensory receptors.
AB - The ultrastructure of five types of presumed sensory receptors in the scolex of
preadults of Proteocephalus longicollis is described. Two types of nonciliate
sensory receptors are situated on the inner surface of the lateral sucker. They
differ from each other in the shape, presence, or absence of a large rootlet,
electron-dense collars, desmosomes, microtubules, and/or vesicles. In addition,
three types of ciliate sensory receptors are found along the edges of the lateral
suckers. They can be differentiated by the length of the cilium, by the number of
electron-dense collars (one or two), and by types of vesicles. Four types of
vesicles were found inside the ciliate sensory receptors. One type of ciliate
sensory receptor occurring in preadults differs markedly from any of the sensory
receptors previously described in adult P. longicollis.
PMID- 10685839
TI - Changes in Trypanosoma cruzi phospholipid turnover induced by parasite contact
with cell membranes.
AB - To investigate the possibility that cell contact could initiate a series of
signals in both the host cell and the flagellate protozoan Trypanosoma cruzi, we
studied [32P]-phospholipid turnover during parasite interaction with cellular
membranes in vitro. Lipid alterations were produced in the parasite during the
initial period of contact with the plasma membranes of human erythrocytes. In the
presence of calcium an increment in phosphatidylethanolamine was observed with a
concomitant decrease in phosphatidic acid fractions, whereas these modifications
were not observed in the absence of calcium. There was an evident decrease in
phosphatidylcholine and a shift in the
phosphatidylinositol/lysophosphatidylethanolamine fraction among the
phospholipids of major turnover in the absence or presence of calcium. Among the
minor labeled species, lysophosphatidylcholine reached levels that duplicated
control values, whereas the amounts of lysophosphatidylinositol,
phosphatidylinositol 4-phosphate, and phosphatidylinositol 4,5-bisphosphate
diminished by over 50%. All of these variations indicate that the parasite's
contact with plasma membranes induces changes involving T. cruzi phospholipids
and suggest the participation of these compounds in the activation of
intracellular mechanisms that might be important during the life cycle of this
parasite.
PMID- 10685840
TI - Immunomodulatory effects in Litomosoides sigmodontis-infected Mastomys coucha.
AB - The levels of parasite-specific IgG1 and IgG2 antibodies and mitogen-induced and
parasite-specific proliferative T-cell responses were determined in Litomosoides
sigmodontis-infected Mastomys coucha throughout an observation period of 400 days
post infection (p.i.). These were compared with the respective reactions in
animals that had been immunized with intrauterine stages/microfilariae of the
parasite and in animals that had been challenged after immunization as determined
at up to 60 days after challenge. IgG1 antibodies to adult antigen developed
early and reached a plateau at 120 days p.i., whereas IgG2 antibodies were not
found before day 60 p.i., increased with rising parasitemia, reached a plateau at
200 days p.i., and, in some animals, even became the predominant IgG subclass.
Proliferative responses of spleen lymphocytes to concanavalin A (Con A) and
lipopolysaccharides (LPS), but not Con-A-induced interleukin 2 (IL-2) production,
were found to be suppressed in infected animals during patency as compared with
uninfected controls. Spleen cells of infected animals showed a weak proliferative
reaction to male antigen but were unresponsive to female and microfilarial
antigen during prepatency and early patency. Subsequently, when microfilaremia
decreased (200 days p.i.), continuously increasing responses to all antigens were
observed. Immunized M. coucha developed specific IgG1 and IgG2 antibodies, and
their spleen cells showed strong proliferative responses to the three L.
sigmodontis antigens. Challenge infections down-regulated the proliferative
responses of spleen cells to filarial antigens as early as during the prepatent
phase of the challenge infection but supported existing IgG1 and IgG2 responses.
PMID- 10685841
TI - A trypanosomatid protein specifically interacts with a mammalian iron-responsive
element.
AB - Intracellular iron homeostasis of vertebrates and invertebrates is mediated
through the interaction of iron-regulatory proteins (IRPs) with mRNAs containing
a bulged hairpin-loop structure termed the iron-responsive element (IRE). We
detected a protein within extracts prepared from Leishmania tarentolae that
specifically interacts with a mammalian IRE; mutations to the IRE that inhibit
the interaction with the mammalian protein have a corresponding effect on the
interaction with the L. tarentolae protein. The disassociation constant noted for
the interaction of the mammalian IRE with the L. tarentolae protein was 0.7+/-0.3
microM, whereas that recorded for the interaction with the mammalian IRP under
these conditions was 5+/-2 nM. The interacting L. tarentolae protein potentially
places the RNA-binding site of the IRP near the root of the eukaryotic
evolutionary tree. However, unlike that of the mammalian IRPs, the L. tarentolae
IRE-binding activity was not induced by growth in iron-depleted media.
PMID- 10685842
TI - Antigenicity of Trichomonas vaginalis heat-shock proteins in human infections.
AB - Patients infected with Trichomonas vaginalis mount humoral and cellular immune
responses that often do not protect against reinfection. The oxidative stressors
produced by leukocytes may trigger a heat-shock-like response in T. vaginalis
trophozoites, helping the parasite to survive host immune defenses. The
antigenicity of T. vaginalis heat-shock proteins (HSPs) was examined by
immunoprecipitation of T. vaginalis heat-induced proteins with sera from infected
patients and controls. When T. vaginalis was heat-shocked, HSPs of 169-167 and
140-137 kDa were specifically recognized by sera from infected male and female
patients. However, the majority of T. vaginalis HSPs were also immunoprecipitated
by control sera; all sera recognized 72- to 71-kDa, 47- to 45-kDa, 38- to 37-kDa,
35-kDa, and 31-kDa heat-induced proteins. At least 15 proteins from non-heat
shocked T. vaginalis were immunoprecipitated by sera from infected patients and
controls, indicating that natural or cross-reacting antibodies could participate
in host responses to trichomoniasis. Molecules of 158, 135, 89, and 74-72 kDa
were immunoprecipitated from some non-heat-shocked parasites only by patients'
sera. A 38-kDa T. vaginalis protein was immunoprecipitated only by sera from
infected females and may be specific for infection in women.
PMID- 10685843
TI - Up-regulation of tumor necrosis factor-alpha and interferon-gamma expression in
the spleen and lungs of mice infected with the human Babesia isolate WA1.
AB - We analyzed cytokine expression in mice infected with the intraerythrocytic
parasites Babesia microti and WA1. In C3H/HeN mice, WA1 infections were fatal,
whereas B. microti infections were resolved. We propose that the proinflammatory
cytokines tumor necrosis factor-alpha (TNFalpha) and interferon-gamma (IFNgamma)
contribute to the WA1-associated disease. WA1 infection was characterized by up
regulation of TNFalpha and IFNgamma mRNA in the spleen. Previous studies in WA1
infected mice showed that pathologic lesions occurred primarily in the lungs,
including pulmonary edema and intravascular margination of leukocytes. Analysis
of cytokine expression in the lungs is important for an understanding of the
disease process in WA1-infected mice. Expression of both TNFalpha and IFNgamma
mRNA was increased in the lungs of WA1-infected mice. Immunohistochemical
staining confirmed the upregulation of these proinflammatory cytokines in the
lungs. Expression of TNFalpha and IFNgamma was not up-regulated in the lungs of
B. microti-infected mice. The results implicate TNFalpha and IFNgamma in the
pathogenesis of WA1-associated disease.
PMID- 10685844
TI - Ultrastructure of the surface structures and haptor of Empleurosoma pyriforme
(Ancyrocephalinae; Monopisthocotylea: Monogenea) from the gills of the teleost
fish Therapon jarbua.
AB - Infections with Empleurosoma pyriforme occur between successive secondary gill
lamellae on both sides of the primary lamella of Therapon jarbua. The haptoral
disc bears two pairs of anchors and a pair of connecting transverse bars. The
attachment of the parasite to the host gill causes inflammation, erosion and
degeneration of the gill epithelia. The ventral anchors consist of an inner core
of irregularly arranged, electron-dense fibrils and a smooth outer core of
electron-lucent fibrils, whereas the surface of the dorsal anchors is ridged.
Both the dorsal and the ventral anchors may be extended or withdrawn. The
connecting transverse bars consist of longitudinally arranged fibrils in an
electron-dense matrix, whereas the tendons consist of fibrils, supported in a
less electron-dense matrix, which interconnect the anchor erector-protractor
muscles and the haptor muscles. Two types of perikarya are present. The less
common type contain large multivesicular bodies and small electron-dense granules
and are located only in the haptor region. The second and more common perikarya
are present throughout the body surface. The cytoplasmic syncytium contains
numerous electron-dense granules and electron-lucent vesicles. Beneath the
syncytium, unicellular epidermal gland cells contain electron-dense granules.
Neurones containing numerous electron-dense vesicles are present in the haptor
region. Uniciliate presumed sensory receptors are distributed over the body
surface. Groups of ciliated sensory structures are present in the forebody.
Ciliated and non-ciliated presumed sensory receptors are present in the sleeve
cavity of the anchors, on the haptor and in the vicinity of the oral apertures.
PMID- 10685845
TI - Isolation and analysis of a new developmentally regulated gene from amastigotes
of Leishmania mexicana mexicana.
AB - Leishmania differentiates from the promastigote to the amastigote stage during
its digenetic life cycle. Characterization of the developmentally regulated genes
during that process would help to elucidate the mechanisms of gene regulation. In
this study, specific fragments of mRNAs from the amastigote stage of L. mexicana
mexicana were discriminated from those of the promastigote and metacyclic stages
by differential display. This technique combined with spliced-leader polymerase
chain reaction allowed isolation of the complete gene VG7A5. The sequence of this
gene did not align with any published L. mexicana sequence. More than one copy of
this gene was identified in the genome by Southern-blot analysis and was
transcribed exclusively in the amastigote stage. At 20 bp upstream from the
splice AG site it has a trans-splicing polypyrimidine tract. The gene encodes the
subcellular localization motifs 5'-GGACT and AAGCT-3' in the 3' untranslated
region of the mRNA. The open reading frame of the gene VG7A5 predicts a
polypeptide of 587 amino acid residues that has a KGRR amidation motif near its
carboxyl terminus, suggesting that in the mammalian host this protein may be
involved in the process of acute inflammation.
PMID- 10685846
TI - Inhibitory activity of anti-interleukin-4 and anti-interleukin-10 antibodies on
Toxoplasma gondii proliferation in mouse peritoneal macrophages cocultured with
splenocytes from infected mice.
AB - Cocultures of splenocytes from Toxoplasma gondii-immunized mice or from naive
mice, separated by a transwell membrane from naive macrophage layers, induced a
decrease in T. gondii proliferation in macrophages in comparison with cultures
without splenocytes or cocultures with splenocytes from infected mice.
Interleukin 4 (IL-4) and IL-10 levels increased in cocultures of splenocytes from
infected mice with naive macrophages. In contrast, the levels of these cytokines
decreased in cocultures with splenocytes from immunized mice. No correlation was
found between the release of interferon-gamma (IFN-gamma) and the inhibition of
parasite multiplication. Cocultures with splenocytes from immunized mice induced
an increase in tumor necrosis factor-alpha (TNF-alpha) levels. In contrast, in
cocultures with splenocytes from infected mice, TNF-alpha production decreased.
In cocultures with splenocytes from infected mice, T. gondii proliferation in
macrophages was neutralized by anti-IL4 or anti-IL10 antibodies and was
associated with increased TNF-alpha production. Moreover, this study demonstrates
the significant combined effect of IL-4 and IL-10 on the down-regulation of
macrophage-effector functions. A soluble positive signal was given by splenocytes
to induce the production of TNF-alpha by macrophages. This signal was inhibited
by IL4 and IL10. This process is biologically relevant in the regulation of T.
gondii proliferation.
PMID- 10685847
TI - First record of Cycloposthium edentatum Strelkow, 1928 from the black-striped
wallaby, Macropus dorsalis.
AB - The cycloposthiid ciliate Cycloposthium edentatum Strelkow 1928 is redescribed
from the stomach content of the black-striped wallaby, Macropus dorsalis (Gray)
following protargol staining and light and electron microscopy. This is the first
record of a cycloposthiid ciliate occurring in a marsupial, as all previous
records have been restricted to eutherian herbivores, especially equids. C.
edentatum was found in 7 (39%) of 18 black-striped wallabies examined, but not in
any of 263 animals belonging to another 20 macropodid species examined. C.
edentatum is distinguished by the form of the macronucleus, the presence of a
longitudinal pellicular groove, a broad posterior tail and pellicular patterning.
C. edentatum specimens recovered from M. dorsalis were smaller than those
reported from horses, being up to 50% shorter and 42% thinner.
PMID- 10685848
TI - Helminth fauna of the wolf (Canis lupus Linnaeus, 1758) in Belorussian Polesie.
PMID- 10685849
TI - Gerbils (Meriones unguiculatus) are highly susceptible to oral infection with
Neospora caninum oocysts.
AB - Laboratory-reared gerbils (Meriones unguiculatus) were found to be highly
susceptible to oral infection with Neospora caninum (NC-Liv strain) oocysts.
Gerbils fed approximately 1000 oocysts became sick or died at 6-13 days post
feeding of oocysts (PFO). N. caninum was isolated in cell culture and from gamma
interferon-knockout mice inoculated with homogenates of mesenteric lymph nodes of
gerbils examined as early as 1 day PFO. Numerous N. caninum tachyzoites were
found in ulcerative lesions in the intestines of gerbils examined at 7-9 days
PFO. In a gerbil fed 10 oocysts, N. caninum tachyzoites were found in lesions in
the brain. Gerbils fed 10 oocysts developed antibodies to N. caninum by 18 days
PFO as determined by the Neospora agglutination test (titers > or =1:500). All
gerbils remained negative for antibodies to Toxoplasma gondii as determined by
the Toxoplasma agglutination test.
PMID- 10685850
TI - Neospora caninum: is it really different from Hammondia heydorni or is it a
strain of Toxoplasma gondii? An opinion.
AB - The published data concerning Toxoplasma gondii, Hammondia hammondi, H. heydorni
and Neospora caninum on one side and between T. gondii on the other were
neglected by most authors. As conclusion we are convinced that there are only two
valid species: Isospora (Toxoplasma) gondii and Hammondia heydorni. The first
includes as a strain H. hammondi and the latter N. caninum. In any case there is
absolutely no reason (with respect to general Zoological nomenclature) to create
new genera!
PMID- 10685851
TI - Motor and cognitive functions in newly diagnosed adult seizure patients before
antiepileptic medication.
AB - OBJECTIVE: Motor and cognitive functions in patients with partial or generalized
onset of seizures were evaluated prior to the administration of antiepileptic
medication. MATERIAL AND METHODS: Motor function, attention and memory of 52
consecutive newly diagnosed adult patients with partial or generalized seizures
were assessed with neuropsychological tests. RESULTS: Patients with partial onset
of seizures did not differ from patients with generalized seizures in tests of
motor function or attention, nor in tests of learning and memory. Compared to
controls patients with epilepsy performed significantly worse on visual motor
tasks, mental flexibility and in delayed visual memory. Within the patient group
as a whole lower education, higher age and symptomatic epilepsy with more
abnormal CT scan findings tended to associate with worse performance in tests of
concentration and mental flexibility and tests of memory. CONCLUSION: These
findings indicate that newly diagnosed adult patients with partial or generalized
onset of seizures prior to treatment with antiepileptic medication experience
some problems in visual motor tasks, mental flexibility and memory even without
the numerous risk factors for cognitive deficits in epilepsy. In newly diagnosed
patients with epilepsy as a whole symptomatic etiology was associated with
somewhat more pronounced cognitive problems.
PMID- 10685852
TI - Weight gain following unilateral pallidotomy in Parkinson's disease.
AB - OBJECTIVE: To determine the clinical correlates and infer pathogenesis of weight
gain following pallidotomy in patients with Parkinson's disease (PD). BACKGROUND:
Surgical ablation of the globus pallidus internus (GPi) improves levodopa induced
dyskinesias, moderately improves most other "cardinal" manifestations of PD, and
has been noted to result in increased weight. METHODS: We incorporated Unified
Parkinson's Disease Rating Scales (UPDRS) subscales, the Beck depression
inventory and feeding questionnaire data into a linear regression model in order
to determine which post-surgical change(s) may lead to weight gain over the first
year following pallidotomy, n = 60. RESULTS: The mean weight gain 1 year after
pallidotomy was 4.0 +/- 4.1 kg. Improvement in "off" motor scores (P < 0.005),
especially gait subscores (P<0.0001), and to a lesser extent improvement in "on"
motor scores (P<0.05) predicted weight gain. Changes in dyskinesia ratings, mood,
food intake, dysphagia, levodopa dose, weight loss in the year prior to
pallidotomy, age, and duration of PD did not correlate with subsequent weight
gain. CONCLUSION: The high correlation between post-pallidotomy weight gain and
"off" motor scores, suggests that this phenomenon is related to some change in
underlying homeostasis associated with changes in the cardinal manifestations of
PD itself, rather than secondary changes resultant from the surgery.
PMID- 10685853
TI - Cardiovascular dysfunction in multiple sclerosis.
AB - Cardiovascular dysfunction (CD) in multiple sclerosis (MS) is related to
involvement of reflex pathways in the brainstem. The battery of CD tests was
applied to a group of 40 healthy subjects and 40 patients with MS, divided in 2
subgroups according to the expanded disability status scale (EDSS). The tests
included: 1) postural blood pressure changes, 2) postural heart rate changes, 3)
heart rate changes on inspiration/forced expiration and 4) ECG R-R interval
measurement on the Valsalva maneuver. Both groups were subjected to the
functional independence scale (FIM). Imaging studies were reviewed and autonomic
dysfunction at other levels was explored. The results showed a statistically
significant difference (P < 0.05) in all tests when comparing patients to
controls. Tests 1 and 4 had the highest significance, with findings of more
severe involvement in patients with a higher EDSS and lower FIM. A correlation
was also found between CD and brainstem lesions on MRI (P < 0.01). A significant
number of MS patients had evidence of CD. Test 1 may be considered a simple
marker, in daily clinical practice, to detect subclinical CD. Subclinical CD is a
cause of disability in this group of patients.
PMID- 10685854
TI - Transferrin in patients with multiple sclerosis: a comparison among various
subgroups of multiple sclerosis patients.
AB - OBJECTIVES: To compare cerebrospinal fluid (CSF) and serum transferrin (Tf)
concentrations, transferrin quotient and index in various subgroups of MS
patients. MATERIAL AND METHODS: CSF and serum transferrin concentrations,
transferrin quotient QTf (i.e. CSF transferrin/serum transferrin x 10(3)) and
index (QTf/Qalbumin) were determined in a group of 51 patients with clinically
definite or probable multiple sclerosis (MS). Patients were subdivided according
to the disease form (relapsing-remitting = RR, secondary progressive = SP,
primary progressive = PP; patients with RR form were further subdivided into
those in the attack and those in remission), disease severity (EDSS 0-5.5, EDSS
6.0-10.0), its treatment (non-treated - including patients treated with vitamins
and/ or vasodilators only, treated - i.e. glucocorticoids and/or
immunosuppressants and/or (exceptionally) beta-interferon), disease duration (0-2
years, >2-10 years, > 10 years) and sex. Correlation of transferrin values with
age was also performed. RESULTS: Serum transferrin was somewhat lower and
significantly more frequently subnormal in PP patients in comparison with the SP
form and the RR form in remission. Transferrin index was significantly higher in
the PP form than in the RR as well as the SP form. Transferrin quotient was
significantly more frequently subnormal in patients in remission compared to
those in the attack of the RR disease. CSF transferrin as well as transferrin
quotient were more frequently subnormal in patients with short disease duration
(0-2 years) than in patients with longer disease duration; these parameters,
however, correlated also significantly with age. CSF transferrin and transferrin
quotient were higher in male than in female patients. CONCLUSION: The authors
conclude that evaluation of transferrin in MS patients - along with albumin - may
help to differentiate among various MS subgroups, since there are significant
differences among RR, SP and PP forms. For this purpose, however, other CSF
protein fractions should be evaluated in parallel in order to obtain more complex
information and to establish a panel of examinations enabling multiple
statistical analyses. Transferrin evaluation in MS may also be of significant
theoretical interest, since transferrin is known to be involved in the regulation
of iron metabolism and it may have a protective role against the oxidative
stress. Moreover, transferrin is a growth factor important for proliferation of
activated T lymphocytes. By means of the use of transferrin quotient and
especially transferrin index, it may be possible to estimate the proportion of
intra-CNS-synthesized transferrin and/or rate of specific transferrin transport
across the blood-CSF barrier. Further studies are, however, needed for such an
evaluation.
PMID- 10685855
TI - IL-1ra serum levels in disease stages of MS--a marker for progression?
AB - Interleukin-1 (IL-1) is one of the major proinflammatory cytokines expressed
consistently in multiple sclerosis (MS) lesions. Interleukin-1 receptor
antagonist (IL-1ra) is the only known naturally occurring specific antagonistic
cytokine counteracting IL-1. Thus IL-1ra may have a downregulating potential in
the disease course of MS. We analysed if circulating IL-1ra could be associated
with different disease stages of MS in sera of 84 MS patients and 18 controls. IL
1ra showed considerable variations in MS patients and controls. Nevertheless we
found significantly elevated serum levels in active as well as in stable disease
stages compared to controls. IL-1ra levels were higher in progressive disease
courses compared to relapsing-remitting MS, but not statistically significant
(median: 516 versus 434 pg/ml). Further analysis with larger groups of patients
and longitudinal studies will clarify if IL-1ra is useful as a prognostic serum
marker in MS.
PMID- 10685856
TI - Cerebellar deficit and respiratory impairment: a strong association in multiple
sclerosis?
AB - The aim of the study was to analyse pulmonary function and to identify reliable
prognostic factors associated with respiratory abnormalities in a consecutive
series of patients with multiple sclerosis (MS). Pulmonary function was evaluated
by means of a battery of measures, including maximal voluntary ventilation,
forced vital capacity, forced expiratory volume, in 71 consecutive patients with
primary and secondary progressive MS. Respiratory impairment was common in MS
patients, occurring in 63.4% of all patients, ranging from 82.9% in non
ambulatory patients (with EDSS score >6.5) to 35.7% in ambulatory patients (with
EDSS score <6). Severity of illness and cerebellar and mental impairment were
significantly negatively associated with basal pulmonary function. Coordination
plays an important role in determining respiratory abnormalities: respiratory
abnormalities were found in 27 out of 32 patients (84.4%) with severe cerebellar
impairment. The presence of severe cerebellar signs was associated with a very
high risk of occurrence of respiratory impairment (O.R. = 6.24; 95% C.I. 1.71
22.82). Other significant variables were severity of illness (EDSS score > 6.5)
(O.R. =4.71; 95% C.I. 1.42-15.66) and long disease duration (> 15 years) (O.R. =
3.39; 95% C.I. 1.01-11.42).
PMID- 10685857
TI - Epidemiological surveillance of Guillain-Barre syndrome in Sweden, 1996-1997.
Network members of the Swedish GBS Epidemiology Study Group.
AB - OBJECTIVES: To set up an epidemiological surveillance system of Guillain-Barre
syndrome (GBS) in Sweden and to evaluate the pilot practice of the system for 2
years. MATERIAL AND METHODS: A network of neurologists reported incident patients
with a GBS diagnosis among a general population of 4.5 million inhabitants in
Sweden during 1996 1997. Historical GBS data from the national hospital in
patient registry were used for predicting incidences and controlling under
reporting. RESULTS: One hundred and seventeen cases were reported. No alarm
signals were identified during the study period. A re-analysis of data in 1996
revealed: 1) a higher than expected incidence in the population aged below 40
years in January, and 2) 27% under-reporting mainly associated to one hospital
and to GBS patients hospitalized outside neurological departments. Threshold
values for GBS incidences among the general and selected populations were
obtained from corrected data. CONCLUSION: - The Swedish Network for GBS
Surveillance can provide immediate support for epidemiological evaluation of
suspected outbreaks or increased GBS incidence.
PMID- 10685858
TI - Evoked potentials in multiple system atrophy (MSA).
AB - OBJECTIVES: To study the involvement of pyramidal tracts and sensory pathways in
multiple system atrophy (MSA). MATERIALS AND METHODS: Evoked potential studies
were performed in 45 MSA patients suffering from either MSA of cerebellar type
(MSA-C) or MSA of parkinsonian type (MSA-P). RESULTS: Motor evoked potentials
were normal in all MSA patients, whereas visual and somatosensory evoked
potential abnormalities were found in about 40% of the MSA patients with no
significant difference between the cerebellar (MSA-C) and parkinsonian (MSA-P)
subgroup. Abnormal latencies of wave III in brainstem auditory evoked potentials
were significantly more frequent in MSA-C. CONCLUSIONS: Abnormalities of
somatosensory, visual and auditory evoked potentials are frequent findings in
MSA, whereas abnormal motor evoked potentials are not a characteristic feature of
the disease.
PMID- 10685859
TI - Cerebrospinal fluid C3 and C4 indexes in immunological disorders of the central
nervous system.
AB - OBJECTIVES: Validation of cerebrospinal fluid (CSF) indexes as a measure for
intrathecal C3 and C4 production. Examination of their role in differential
diagnosis of immunological disorders of the central nervous system (CNS).
MATERIAL AND METHODS: Correlative study in controls (low back pain without disk
herniation) between the CSF/serum ratio (Q) for albumin, and Q C3 and Q C4.
Comparative study of C3 and C4 indexes in patients with CNS dysfunction due to
relapsing-remitting (RR) multiple sclerosis (MS), secondary progressive (SP) MS,
systemic lupus erythematosus (SLE), and human immunodeficiency virus (HIV)
infection. RESULTS: Strong and statistically highly significant correlations
between Q albumin and Q C3 (r=0.89, P=0.0001), and Q C4 (r=0.68, P= 0.0001). In
MS patients decreased mean values for serum (RR, SP) and CSF (RR) C3, and
increased C3 index mean value (RR, SP). In CNS SLE increase of mean C3 and C4
index values. In CNS HIV increase of mean C3 and C4 index values, and CSF C3 and
C4 concentrations. Most individual index values were within the reference range.
CONCLUSION: CSF index is a valid tool to detect intrathecal C3 or C4 production.
C3 or C4 index contributes little to the differential diagnosis of immunological
CNS disorders. C3 might play a pathogenic role in various immunological CNS
disorders.
PMID- 10685860
TI - Distribution of cerebral microembolism in the anterior and middle cerebral
arteries.
AB - BACKGROUND AND PURPOSE: Cerebral infarcts occur more frequently along the middle
(MCA) than the anterior cerebral artery (ACA) territory. The reason(s) for this
difference remains speculative. The objective of this study was to investigate
the distribution of cerebral microemboli as detected by transcranial Doppler
ultrasound (TCD) along the MCA and ACA territories. METHODS: Records of
consecutive patients examined for the presence of cerebral microembolism during a
32-month period at the Neurovascular Laboratory were reviewed. Of the original
375 TCD studies in 268 patients, 28 studies in 24 patients demonstrated
microembolic signals (MES) and monitored the MCA and ACA on the same side. TCD
studies were performed on TC-2000 or TC-2020 instruments. MES positive studies
were saved and off-line reviewed. MES satisfied previously established criteria.
RESULTS: MES were more frequent in the MCA than the ACA in 85.7% (24/28) of
studies (P < 0.01). Of the total number of MES (n = 979), 29.6% (n = 290) were
detected in the ACA and 70.4% (n=689) in the MCA (P<0.01). The mean (+/- SD)
intensity of MCA MES of 12.2 (+/- 2.4) dB was significantly lower than that of
ACA MES of 14.8 (+/-3.2) dB (P=0.05). The mean (+/-SD) duration of MCA MES of
38.1 (+/- 45.3) ms was longer than that of ACA MES of 30.7 (+/-34.0) ms (P=0.05).
CONCLUSIONS: Cerebral microembolism occurs more frequently in the MCA than the
ACA, which may explain the uneven distribution of cerebral infarcts along these
arterial territories. Furthermore, there are significant differences in the
characteristics of ACA and MCA MES.
PMID- 10685861
TI - Clinical lacunar syndromes as predictors of lacunar infarcts. A comparison of
acute clinical lacunar syndromes and findings on diffusion-weighted MRI.
AB - OBJECTIVES: To evaluate if patients with acute lacunar syndromes have acute
lacunar infarcts or other types of cerebral lesions on diffusion-weighted MRI.
METHODS: Patients with acute lacunar syndromes underwent echo-planar diffusion
MRI of the brain within 3 days after stroke onset. Localization and size of
lesions with hyperintense signal were determined, compared with clinical
characteristics and with findings on follow-up T2-weighted MRI. RESULTS: Twenty
three patients participated in the study. Thirteen patients had pure motor
stroke, 1 pure sensory stroke, 8 sensorimotor stroke, and 1 ataxic hemiparesis.
Twenty-two patients had at least one lesion with increased signal on diffusion
weighted MR images. These acute lesions were in the internal capsule/ basal
ganglia/thalamus in 13 patients, subcortical white matter in 5 patients,
brainstem in 2 patients, cortex (multiple small lesions) in 1 patient, and cortex
+ basal ganglia in 1 patient. The median volume of the lesions was 0.6 ml on the
initial examination and on follow-up, of 17 patients after 1 to 5 months, 0.5 ml.
CONCLUSIONS: Almost all patients with acute ischemic lacunar syndromes have acute
lesions on echo-planar diffusion-weighted MRI within 3 days after stroke onset.
These lesions are mostly small and subcortical, compatible with lacunar infarcts
caused by single penetrating artery occlusion, but in a minor proportion of
patients (2 of 23 in our study) a cortical involvement is found.
PMID- 10685862
TI - Soluble and cell surface ICAM-3 in blood and cerebrospinal fluid of patients with
multiple sclerosis: influence of methylprednisolone treatment and relevance as
markers for disease activity.
AB - OBJECTIVE: The expression of intercellular adhesion molecule-3 (ICAM-3), a member
of the Ig supergene family, is restricted to immune competent cells. Expression
of soluble and cell surface ICAM-3 (s- and c-ICAM-3) is preferentially seen in
the state of low activation of the immune system. We studied the relevance of the
expression levels of s- and c-ICAM-3 in cerebrospinal fluid (CSF) and blood as
markers for disease activity as well as the influence of high-dose
methylprednisolone (MP) treatment upon the expression of s- and c-ICAM-3 in blood
of patients with multiple sclerosis (MS). MATERIALS AND METHODS: A total of 33
patients (relapses n = 25, remission n = 8) with relapsing-remitting MS were
included into the study. CSF and blood were acquired from all of them. Of the
patients 24 were treated with high-dose MP. In those, blood was additionally
collected at the 10th day of the therapy and after 3 months. Expression of c-ICAM
3 was determined by two colour FACS analysis, whereas the concentration levels of
s-ICAM-3 were measured by ELISA. RESULTS: In CSF we detected a significant
decrease of the expression levels of c-ICAM-3 on CD3+ T cells in 25 patients
suffering from an acute relapse in contrast to 8 patients with remission (P=
0.04). In comparison to the levels before treatment and after 3 months, at the
10th day of MP treatment we obtained highly significant changes of the expression
values of c-ICAM-3 both on CD3+ T cells (P = 0.0004; P= 0.005) and CD14+
monocytes/macrophages (P =0.0006; P=0.008) on the 10th day of high-dose MP
treatment from 24 MS patients. CONCLUSION: The increase of ICAM-3 levels might
indicate the anti-inflammatory effect of the MP treatment. It could be
interesting to search for similar effects investigating the new immune
modulatoring therapy forms of MS.
PMID- 10685863
TI - Occult vascular malformations of the spinal cord: report of four cases not
detected by angiography.
AB - Angiographically occult vascular malformations (AOVMs) are reported. Although
cavernous malformations, the most common type among the spinal intramedullary
AOVMs, have been well documented, the natural history and clinical features of
non-cavernous type AOVMs of the spinal cord remain obscure. We have evaluated
four cases of non-cavernous AOVMs in the past 9 years. Although the clinical
features and magnetic-resonance imaging (MRI) of three cases were similar to
those previously reported, the other one had unusual features of insidious onset
with limb asymmetry. The natural history of intramedullary occult AVMs remains
enigmatic. One speculation for the neurological deterioration is that it results
from repeated hemorrhages around the vessels or from intralumenal thrombosis.
PMID- 10685864
TI - Testing the specificity of allosteric modulators of muscarinic receptors in
phylogenetically closely related histamine H1-receptors.
AB - Gallamine, alcuronium and W84 (hexane-1,6-bis[dimethyl-3'-phthalimidopropyl
ammonium bromide]) are prototype allosteric modulators of the G-protein coupled
muscarinic acetylcholine receptor family, especially of the M2-subtype. In order
to probe the specificity of muscarinic allosteric modulation, we checked whether
these agents interact with histamine H1-receptors which have a high homology with
muscarinic receptors. Binding experiments (38 mM Na2HPO4, 12 mM KH2PO4, pH 7.5)
were performed with the H1-receptor antagonist [3H]mepyramine ([3H]MEP) in guinea
pig cerebellar homogenates. For the sake of comparison, binding of [3H]N
methylscopolamine ([3H]NMS) at muscarinic M2-receptors was measured in porcine
cardiac homogenates under identical conditions. The modulators retarded [3H]NMS
dissociation (t1/2 control=1.3 min) concentration-dependently indicating their
allosteric action with half-maximum effects for gallamine at EC50,discs=27
microM, for alcuronium at EC50,diss=53 nM, and for W84 at EC50,diss=170 nM. In
contrast, [3H]MEP dissociation from H1-receptors (t1/2,control=2.6 min) remained
unchanged up to concentrations of 1 mM of the modulators. Equilibrium binding of
[3H]NMS (KD=0.46 nM, Bmax=98 fmol/mg protein) was inhibited by gallamine,
elevated by alcuronium and left almost unchanged by W84, indicating negative,
positive and nearly neutral cooperativity, respectively, with the radioligand.
The ternary complex model of allosteric actions yielded the equilibrium
dissociation constants K(A) for the binding of the allosteric modulators to free
M2-receptors: K(A,gallamine)=100 nM, K(A,alcuronium)=450 nM, K(A,W84)=69 nM. In
H1-receptors, more than 1,000-fold higher concentrations than in M2-receptors
were required to elicit an effect on the binding of [3H]MEP (KD=1.2 nM, Bmax=205
fmol/mg protein). Half-maximal reduction was observed at 10 mM for gallamine, 1
mM for alcuronium and 92 microM for W84. In conclusion, the muscarinic modulators
have little effect on the histamine H1-receptors.
PMID- 10685865
TI - Caffeine inhibits a low affinity but not a high affinity mechanism for
cholecystokinin-evoked Ca2+ signalling and amylase release from guinea pig
pancreatic acini.
AB - Caffeine has been found to inhibit the formation and action of Ca2+-mobilizing
inositol 1,4,5-trisphosphate (IP3) in pancreatic acinar cells. The aim of the
present study was to investigate the effects of caffeine on cytoplasmic Ca2+
concentrations ([Ca2+]i) and amylase release in response to different agonists.
[Ca2+]i was determined by cytofluorometry using fura-2 as indicator and amylase
release with a substrate reagent. Stimulation with low concentrations of
carbachol or cholecystokinin octapeptide (CCK-8) induces [Ca2+]i oscillations
whereas higher concentrations cause sustained elevation of [Ca2+]i. The less
efficacious agonists pilocarpine and CCK-JMV-180 evoke oscillations only.
Caffeine inhibited carbachol-induced elevation of [Ca2+]i and amylase responses
in a competitive manner, abolishing the responses to low and incompletely
inhibiting the responses to high concentrations of the agonist. Also, the [Ca2+]i
elevations by pilocarpine were abolished by caffeine. The effects on CCK-8
induced elevation of [Ca2+]i and amylase secretion were paradoxical, the caffeine
inhibition being more pronounced at high than at low concentrations of CCK-8.
This enigma was further emphasized by moderate effects of caffeine on the
responses to CCK-JMV-180. The results indicate that carbachol, pilocarpine and
high concentrations of CCK-8 elicit IP3-mediated responses and that CCK-JMV-180
and low concentrations of CCK-8 elevate [Ca2+]i and stimulate amylase release by
another signal transduction mechanism.
PMID- 10685866
TI - Ca2+ entry but not Ca2+ release is necessary for desensitization of
ET(A)receptors in airway apithelial cells.
AB - Ca2+ transients evoked by endothelin-1 (ET-1) were measured in single cells of a
human tracheal epithelial cell line using the fluorescent Ca2+ indicator fura-2.
In line with a previous study, a single exposure to ET-1 (10 nM) for 10-20 s
resulted in a long-lasting desensitization to a subsequent challenge by the
peptide, without affecting sensitivity to agonists for other Ca2+-mobilizing
receptors such as P2y or H1, respectively. In the absence of extracellular Ca2+
ET-1 elicited a Ca2+ signal of comparable amplitude as in the presence of
extracellular Ca2+ but of shorter duration. Exposure to ET-1 in the absence of
Ca2+ caused significantly less desensitization. Inhibition of the Ca2+ entry
component of the Ca2+ transient by means of SK&F 96365, an inhibitor of Ca2+
entry, had effects comparable to Ca2+ removal. The Ca2+ transient was shortened
but not significantly reduced in amplitude, and desensitization was reduced in
the presence of the compound. These data demonstrate that desensitization of
ET(A) receptors (ET(A)R) is promoted by transmembrane Ca2+ entry but not by Ca2+
release.
PMID- 10685867
TI - Reactive oxygen species-induced aortic vasoconstriction and deterioration of
functional integrity.
AB - Oxygen derived free radicals and other reactive oxygen species (ROS) are involved
in a variety of disease states, which can have cardiac and vascular implications.
The present study was performed to investigate the mechanism of ROS-induced
vasoconstriction and the influence of ROS on the functional integrity of isolated
rat thoracic aorta. ROS were generated by means of electrolysis (30 mA, during
0.5, 1, 2 or 3 min) of the organ bath fluid. ROS induced a transient
(approximately 60 min) vasoconstriction and the maximally induced contraction was
dependent on the duration of electrolysis. Dimethyl sulfoxide (DMSO) diminished
the ROS-induced vasoconstriction almost completely, indicating a major influence
of hydroxyl radicals on contractility. The dual cyclooxygenase/lipoxygenase
inhibitor, meclofenamate, completely prevented the ROS-induced vasoconstriction.
The phospholipase A2 (PLA2) inhibitor, oleyloxyethyl phosphorylcholine, was able
to reduce the vasoconstriction elicited by ROS by approximately 70%. Conversely,
the specific cytoplasmic PLA2 inhibitor arachidonyl trifluoromethylketone proved
ineffective in this respect. By using the specific mitogen-activated protein
kinase (MAPkinase) kinase inhibitor PD98059, it was shown that the activation of
extracellular-regulated kinase (ERK) MAPkinase contributes to the ROS-induced
vasoconstriction. The effects of ROS on the functional integrity of the aortae
were investigated, in particular with respect to receptor (alpha1-adrenoceptor)
and non-receptor-mediated contractile responses (high potassium solution). In
addition, both the endothelium dependent (methacholine) and endothelium
independent (sodium nitroprusside) vasorelaxation were investigated before and
after ROS exposure. Electrolysis periods of 0.5 and 1 min induced a modest
leftward shift of the concentration response curves for the alpha1-adrenoceptor
agonist methoxamine. Longer electrolysis periods of 2 and 3 min additionally
decreased the maximal response to (alpha1-adrenoceptor stimulation. Methacholine
induced vasorelaxation proved diminished in aortae subjected to electrolysis
(0.5, 1, 2 and 3 min), whereas relaxation to sodium nitroprusside was nearly
complete in all groups. KCl-induced contractions proved attenuated only after
longer electrolysis periods of 2 and 3 min. This ROS-induced deterioration of
functional integrity was almost completely prevented by 0.6% DMSO. From these
results we may conclude that ROS induce an eicosanoid and ERK MAPkinase-mediated
vasoconstriction in isolated rat thoracic aorta. In addition, exposure to ROS
leads to a deterioration of functional integrity characterized by endothelial
dysfunction and decreased contractile function.
PMID- 10685868
TI - Pertussis toxin suppresses carbachol-evoked cardiodepression but does not modify
cardiostimulation mediated through beta1- and putative beta4-adrenoceptors in
mouse left atria: no evidence for beta2- and beta3-adrenoreceptor function.
AB - Activation of beta1-, beta2-, beta 3- and putative beta4-adrenoceptors modifies
cardiac function. These receptors are usually coupled to Gs protein, but beta2-
and beta3-adrenoceptors could also couple to Gi/o proteins. The mouse heart is
used increasingly for studies of genetically disrupted or overexpressed proteins,
including beta-adrenoceptor subtypes. We therefore investigated in contracting
mouse left atria (2 Hz, 37 degrees C) if inactivation of Gi/o proteins with
pertussis toxin modifies or uncovers effects mediated through beta-adrenoceptor
subtypes. The negative inotropic effects of carbachol in atria exposed to
catecholamine or high calcium (6.8 mmol/l) were assumed to be mediated through
activation of muscarinic receptors coupled to Gi/o. We report conditions under
which incubation of left atria with 200 ng/ml pertussis toxin for 24 h nearly
abolished the carbachol responses. Although it has been reported that muscarinic
receptor-mediated cardiodepression has an obligatory contribution of nitric
oxide, the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine (0.1-1
mmol/l) did not modify the negative inotropic effects of carbachol, inconsistent
with an involvement of nitric oxide. The positive inotropic effects of (-)
noradrenaline and (-)-adrenaline, mediated through beta1-adrenoceptors, were not
affected by pertussis toxin. (-)-Adrenaline did not cause positive inotropic
effects attributable to beta2-adrenoceptor-mediation, in the presence of CGP
20712A (300 nmol/l) to block beta1-adrenoceptors, in control atria or atria
pretreated with pertussis toxin. The positive inotropic effects of (-)-CGP 12177
(1 micromol/l), a compound with agonist activity at the putative beta4
adrenoceptor, were unaffected by pertussis toxin. The beta3-adrenoceptor
selective agonist BRL 37344 (1 micromol/l), in the presence of (-)-propranolol
(200 nmol/l), did not cause positive or negative inotropic effects in control and
pertussis toxin-treated atria. In left atria obtained from mice injected with 150
microg/kg i.p. pertussis toxin which abolished carbachol-evoked cardiode
pression, the positive inotropic effects of (-)-adrenaline were antagonised by
CGP 20712A. The beta2-adrenoceptor-selective antagonist ICI 118551 (50 nmol/l)
did not cause additional blockade of the effects of high (-)-adrenaline
concentrations in the presence of CGP 20712A, ruling out the involvement of beta2
adrenoceptors. The results with intraparenteral PTX validate our in vitro PTX
method. We conclude that inhibition of murine Gi/o proteins does not alter atrial
positive inotropic effects mediated through beta1- and putative beta4
adrenoceptors and does not reveal functional beta2- and beta3-adrenoceptors.
PMID- 10685870
TI - K(ATP) channel blocker HMR 1883 reduces monophasic action potential shortening
during coronary ischemia in anesthetised pigs.
AB - ATP-sensitive potassium channels (KATP) open during myocardial ischemia. The
ensuing repolarising potassium efflux shortens the action potential. Accumulation
of extracellular potassium is able to partially depolarise the membrane, reducing
the upstroke velocity of the action potential and thereby impairing impulse
conduction. Both mechanisms are believed to be involved in the development of
reentrant arrhythmias during cardiac ischemia. The sulfonylthiourea HMR 1883 (1
[[5-[2-(5-chloro-O-anisamido)ethyl]-methoxyphenyl]sulfonyl]-3-m ethylthiourea)
was designed as a cardioselective KATP channel blocker for the prevention of
arrhythmic sudden death in patients with ischemic heart disease. The aim of this
study was to show that this compound, which has already shown antifibrillatory
efficacy in dogs and rats, is able to inhibit ischemic changes of the action
potential induced by coronary artery occlusion in anesthetised pigs. Action
potentials were taken in situ with the technique of monophasic action potential
(MAP) recording. In a control group (n=7), three consecutive occlusions of a
small branch of the left circumflex coronary artery resulted in reproducible
reductions in MAP duration and a decrease in upstroke velocity. In a separate
group (n=7), HMR 1883 (3 mg/kg i.v.) significantly (P<0.05) reduced the ischemia
induced shortening of the MAP: during the first and second control occlusion of
the coronary artery in the HMR 1883-group, MAP50 duration shortened from 218.5 +/
3.0 ms to 166.7 +/- 3.3 ms and from 219.7 +/- 4.5 ms to 164.9 +/- 1.8 ms,
respectively. After HMR 1883, during the third occlusion, MAP duration decreased
from 226.9 +/- 3.6 ms to 205.3 +/- 4.3 ms only corresponding to 59% inhibition.
HMR 1883 also improved the upstroke velocity of the MAP, which was depressed by
ischemia: in the two preceding control occlusions ischemia prolonged the time to
peak of the MAP, an index for upstroke velocity, from 10.83 +/- 0.43 ms to 39.42
+/- 1.60 ms and from 12.97 +/- 0.40 ms to 37.17 +/- 2.98 ms, respectively. With
HMR 1883, time to peak during ischemia rose from 12.42 +/- 0.51 ms to 25.53+/
2.51 ms only, corresponding to an average inhibitory effect of 53.4%. The
irregular repolarisation contour of the ischemic MAP was also improved. In
conclusion, the present results indicate that HMR 1883 effectively blocks
myocardial KATP channels during coronary ischemia in anesthetised pigs,
preventing an excessive shortening of the action potential and improving
excitation propagation.
PMID- 10685869
TI - Effects of imidazoline binding site ligands on the growth and viability of clonal
pancreatic beta-cells.
AB - Pancreatic beta-cells express imidazoline binding sites which play a role in the
regulation of insulin secretion, but it is not known whether ligands for these
sites also affect other aspects of beta-cell physiology. In the present study, we
have investigated the effects of a range of imidazoline reagents on the growth
and viability of clonal pancreatic beta-cells (RINm5F and HIT-T15). Three
imidazoline compounds (idazoxan, phentolamine and antazoline) were found to cause
marked inhibition of beta-cell growth in a time and concentration dependent
manner. Idazoxan was the most potent of these with as little as 0.5 microM
causing a significant decrease in beta-cell viability (EC50 approximately 10
microM). All three imidazolines also decreased the viability of clonal beta-cells
in parallel with their inhibitory effects on cell growth. These effects were not
reproduced by any of a wide-range of other imidazoline compounds, including
effective insulin secretagogues such as efaroxan and RX821002. The effects of the
three ligands did not correlate with their relative potencies for binding to any
of the well-characterised imidazoline binding sites nor to alpha2-adrenoceptors.
In addition, the inhibitory responses were not antagonised by other imidazoline
binding site ligands. The inhibitory effects of idazoxan on the growth of RINm5F
and HIT-T15 beta-cells required as little as 3-h exposure to the imidazoline and
were not readily reversible when the reagent was removed. Reductions in growth
rate were accompanied by marked alterations in the morphology of the cells, which
could be detected before loss of viability. Cells exposed to phentolamine showed
the characteristic features of apoptosis in that the nuclei were condensed (as
judged by acridine orange staining) and electrophoresis of DNA revealed the
presence of oligonucleosomal fragmentation. These changes could not be detected
in cells exposed to idazoxan despite the more profound reduction in viability
induced by this agent. We conclude that a sub-group of imidazoline compounds can
exert profoundly detrimental effects on the growth and viability of clonal beta
cells but that these effects do not correlate with their binding affinity at
imidazoline binding sites or alpha2-adrenoceptors.
PMID- 10685871
TI - Protective effects of calcitonin gene-related peptide on guinea-pig cardiac
anaphylaxis.
AB - Anaphylactic events occurring in cardiac tissues can result in cardiac
dysfunction via vasoconstriction and arrhythmias. Calcitonin gene-related peptide
(CGRP) is the most potent vasodilator and possesses anti-arrhythmic action. We
examined the influence of CGRP on cardiac anaphylaxis in guinea-pigs. In the
Langendorff-perfused heart of passively sensitized guinea-pigs, antigen challenge
evoked a decrease in coronary flow, left ventricular pressure and its maximum
first derivatives (+/-dP/dtmax) and an increased heart rate. Antigen challenge
also induced atrioventricular conduction block. Treatment with CGRP (1 or 3 nM)
significantly improved the recovery of cardiac function and reduced the incidence
and duration of atrioventricular block without influencing the increased heart
rate. Pretreatment with capsaicin caused effects similar to those of CGRP and
markedly elevated the content of CGRP in coronary effluent. Ischaemic
preconditioning, induced by two cycles each of 5 min global ischaemia and 5 min
reperfusion, also improved cardiac function and raised the level of CGRP in
coronary effluent. The protective effects of ischaemic preconditioning were
abolished in the presence of the CGRP receptor antagonist CGRP8-37. Histamine
release did not differ significantly during any of the interventions. The
findings of the present study indicate that, in guinea-pig hearts, CGRP protects
against cardiac anaphylaxis and that the cardioprotection by CGRP is independent
of histamine release.
PMID- 10685872
TI - Androgen deprivation, estrogen treatment and vascular function in male rat aorta.
AB - The beneficial effects of estrogen on arterial function in women are well
established, whereas studies concerning the vascular role of androgens have
produced conflicting results. In the present study, we examined the effects of
androgen deprivation and of estrogen treatment on vascular responses in male
rats. Vascular reactivity was studied in aortic rings excised from intact and
castrated rats, which had been implanted with capsules containing either 17beta
estradiol (E2) or its vehicle for 5 days. Contractile responses to noradrenaline
were potentiated by castration and by E2 treatment. Concentration-response curves
for N-methyl-L-arginine and superoxide dismutase indicated that the tone-related
release of NO increased in tissues from castrated, compared with intact rats, but
was not affected by E2 treatment. Endothelium-dependent relaxation elicited by
carbachol and histamine were not altered by castration and were attenuated by E2
in preparations from intact, but not from castrated rats. Moreover, aortic
prostacyclin release dropped by about 40% after E2 treatment in tissues from both
intact and castrated animals. Similarly, smooth muscle sensitivity to NO
significantly decreased following castration and E2 treatment, as assessed by
responses to sodium nitroprusside. Finally, no differences among groups were
detected in platelet thromboxane A2 production. Thus, vascular responses in male
rats were not improved by androgen deprivation alone or by E2 treatment, whose
effects differed in the presence or absence of androgens. These findings provide
evidence for the gender specificity of the vascular effects of estrogen and may
be consistent with a beneficial role of physiologic levels of male sex hormones
in arterial function.
PMID- 10685873
TI - Gender and hypertension interact to regulate neuropeptide Y receptor
responsiveness.
AB - We have compared the interaction between gender and strain (normotensive Wistar
Kyoto vs. spontaneously hypertensive rats) in the regulation of cardiovascular
and renal Y1 and Y5-receptor-mediated responses to neuropeptide Y. Anaesthetized
rats received intravenous infusions of 0.3-10 microg/kg per min neuropeptide Y
(45 min each) or vehicle. Enhancements of mean arterial pressure, renovascular
resistance, diuresis and natriuresis were measured. Parallel group comparisons
were performed on male normotensive, female normotensive, male hypertensive and
female hypertensive rats. Gender and strain significantly affected the
cardiovascular and renal neuropeptide Y responses. While neuropeptide Y elevated
mean arterial pressure and renovascular resistance in all four groups, the extent
of the alterations differed up to two- to threefold between genders and/or
strains. Neuropeptide Y-induced diuresis and natriuresis were similar in male and
female normotensive rats, desensitized in male but augmented in female
hypertensive rats. We conclude that previously reported cardiovascular and renal
neuropeptide Y responses are regulated by gender and the presence of
hypertension. However, at least for renal function alterations in female
hypertensive vs. male normotensive rats cannot be predicted from those in male
hypertensive and female normotensive rats.
PMID- 10685874
TI - Noradrenoceptor antagonism with idazoxan improves L-dopa-induced dyskinesias in
MPTP monkeys.
AB - Treatment of Parkinson's disease with L-dopa is plagued in a majority of patients
by dyskinesias. Noradrenaline/dopamine interactions are proposed on behavioral,
biochemical, physiological and anatomical grounds. The aim of the study was to
test the potential antidyskinetic effect of the alpha2-adrenoceptor antagonist,
idazoxan, in a primate model of Parkinson's disease. Six female cynomolgus
monkeys previously rendered parkinsonian by the toxin 1-methyl-4-phenyl-1,2,3,6
tetrahydropyridine (MPTP) and presenting an unchanged syndrome for several months
were used. All responded readily to L-dopa but had developed dyskinesias which
were manifested with each dose. In the first part of the study, seven doses of
idazoxan (ranging from 0.25 mg/kg to 10 mg/kg, p.o.) were administered together
with the vehicle or in combination with a fixed dose of L-dopa/benserazide
(100/25 mg, p.o.). In the second part of the study, a fixed dose of idazoxan (7.5
mg/kg) was administered daily for 10 days and L-dopa was added to idazoxan on
days 1, 4, 7 and 10. Vehicle (empty capsule) was used as control. Idazoxan, by
itself (ranging from 5 mg/kg to 10 mg/kg), increased locomotor activity and
improved the disability score with virtually no dyskinesias in three animals. In
combination with L-dopa, idazoxan did not impair the antiparkinsonian response
but significantly reduced dyskinesias in all six animals up to 65% at doses of
7.5 mg/kg and 10 mg/kg and delayed their onset, so that the "ON" state without
dyskinesias was prolonged. The antidyskinetic effect of idazoxan was maintained
when repeatedly administered for 10 days. On day 10, the locomotor response to L
dopa was significantly potentiated by chronic administration of idazoxan. Our
results indicate that idazoxan has some antiparkinsonian effect of its own and
may constitute a useful adjunct to L-dopa as it can reduce dyskinesias without
impairing the relief of symptoms, this effect being maintained over time in this
model.
PMID- 10685875
TI - A comparison of the acute effects of zotepine and other antipsychotics on rat
cortical dopamine release, in vivo.
AB - The acute effects of systemic administration of the antipsychotic drug, zotepine,
on extracellular dopamine (DA) in the frontal cortex of freely-moving rats were
studied using in vivo microdialysis and compared with the actions of clozapine,
olanzapine and haloperidol. Treatment with zotepine (1.0 mg/kg, i.p.) resulted in
a prolonged elevation of cortical DA levels for up to 180 min post-drug. A
maximal rise of +333% was observed at 120 min post-zotepine treatment. Clozapine
(10.0 mg/kg, i.p.) also evoked a rise in extracellular DA which was similar in
duration (200 min) to that resulting from treatment with zotepine. A maximal rise
of +223% was observed at 100 min post-clozapine treatment. Olanzapine (1.0 mg/kg,
i.p.) resulted in an immediate increase in DA levels which was maximal 40 min
post-treatment (+280%) with levels returning to pre-injection values by 100 min
after dosing. In contrast, haloperidol (0.1 mg/kg, i.p.) had no measurable
influence on cortical DA levels. Local perfusion with the NA uptake inhibitor,
nisoxetine (10 microM), resulted in an increase in cortical DA levels which was
maximal at 100 min post-onset of perfusion (+257% above baseline). Administration
of zotepine (1.0 mg/kg, i.p.) during nisoxetine perfusion elevated DA levels to a
maximum of +301% above baseline, 60 min post-zotepine. These results show that
acute administration of each of three drugs with an atypical antipsychotic
profile causes an elevation of cortical DA in freely-moving rats at doses
relevant to those derived from animal models which predict antipsychotic
activity. As a dysfunction in cortical DA is thought to be involved in both the
negative symptoms of schizophrenia and cognitive deficits in schizophrenic
patients, it is possible that zotepine's ability to elevate cortical DA levels
may underlie its effectiveness in successfully treating these components of
schizophrenia. Furthermore, the ability of zotepine to elevate cortical DA is
more likely to derive from its inhibition of the NA transporter rather than DA
receptor blockade in this region.
PMID- 10685876
TI - Effects of inescapable shock and conditioned fear on the release of excitatory
and inhibitory amino acids in the locus coeruleus.
AB - We investigated the importance of endogenous amino acids in the locus coeruleus
in inescapable electric shock and conditioned fear. In naive rats and in rats
exposed to noise (N), light (L) and electric shock (S) or to N + L only, the
locus coeruleus was superfused with artificial cerebrospinal fluid through a push
pull cannula and the release of GABA, taurine, glutamate, aspartate, serine and
glutamine was determined in the superfusate by HPLC after derivatization with o
phthaldialdehyde. Locomotor activity, arterial blood pressure and heart rate were
telemetrically monitored. The placement of naive rats or conditioned rats from
their home cage to a chamber provided with a grid-floor for shock virtually did
not change the release rates of the amino acids in the locus coeruleus. Motility
was enhanced in naive and conditioned rats to a similar extent. Blood pressure
and heart rate were enhanced in conditioned rats only. Exposure to N + L + S for
5 min greatly enhanced the release rates of all determined amino acids in the
locus coeruleus. In conditioned rats the increase in release of most amino acids
lasted longer than in naive rats. Electric shock also enhanced motility, blood
pressure and heart rate. In conditioned rats, motility and cardiovascular changes
were more pronounced and/or lasted longer than in naive rats. Exposure of
conditioned rats to the conditioned stimuli N + L for 5 min led to an increased
release of taurine and aspartate. The enhanced release of taurine lasted 30 min.
Exposure to N + L did not affect the release rates of amino acids in naive rats.
N + L did not influence motility but arterial blood pressure and heart rate were
elevated in conditioned rats. The findings show that inescapable electric shock
enhances the release of several amino acids in the locus coeruleus, while
conditioned fear selectively increases the outflow of taurine and aspartate.
Moreover, conditioned fear prolongs the response of excitatory and inhibitory
amino acids to electric shock. The results suggest that an excitatory amino acid
(aspartate) and an inhibitory amino acid (taurine) of the locus coeruleus are
implicated in conditioned fear.
PMID- 10685877
TI - Gabapentin-lactam, a close analogue of the anticonvulsant gabapentin, exerts
convulsant activity in amygdala kindled rats.
AB - The cyclic GABA analogue gabapentin (GBP), which recently has been marketed for
treatment of epilepsy, is particularly effective against complex-partial seizures
as occurring in temporal lobe epilepsy. In the present study, we compared the
effects of GBP and its lactam analogue (GBP-L) in the amygdala kindling model of
temporal lobe epilepsy. In fully kindled rats, GBP (50 mg/kg and 100 mg/kg i.p.)
dose-dependently increased the threshold for focal seizures and inhibited the
progression from focal to generalized seizures. This effect was not associated
with any marked adverse effects. In contrast, GBP-L (10-50 mg/kg) induced
myoclonic activity and generalized clonic seizures in kindled rats, demonstrating
a striking qualitative difference between the two compounds. By comparison with
non-kindled rats it was shown that kindling markedly enhanced the sensitivity of
rats to the convulsant activity of GBP-L. The finding that the anticonvulsant
efficacy of GBP is lost by lactam formation indicates that GBP and GBP-L differ
in their mechanism(s) of action.
PMID- 10685878
TI - Changes in NMDA receptor subunit gene expression in the rat brain following
withdrawal from forced long-term ethanol intake.
AB - Changes in mRNA levels of N-methyl-D-aspartate receptor (NR) subunits were
studied in a rat model of withdrawal from forced ethanol ingestion over a period
of 8 days. In part, this model may reflect the epsilon-type of human alcoholism
according to Jellinek (College University Press, New Haven; 1972). The epsilon
type is characterized by dipsomania over a period of several days, recurring
every few months and often followed by ethanol-induced seizures. Seizures may be
modulated by an increased glutamatergic neurotransmission to excitatory or
inhibitory neurons on the basis of a changed gene expression of NR subunits. This
hypothesis promoted the present study. Film autoradiograms and emulsion-coated
brain sections following labeling of cholinergic and GABAergic neuron populations
were evaluated. NR subunit 1 (NR1) expression, studied with a probe recognizing
all NR1 transcripts, was unchanged after withdrawal from chronic ethanol
treatment compared to control animals. Using probes specific for different splice
segments of NR1, however, we found that, in ethanol-treated rats, the expression
of NR1-2 was decreased in all, and that of NR1-4 in all but one, areas
investigated (only single label experiments were performed with NR1 splice
variants). Withdrawing rats revealed a higher expression of NR subunit 2A (NR2A)
mRNA in GABAergic neurons. No changes could be observed at the regional level.
Conversely, NR2B mRNA was not substantially altered in cholinergic and GABAergic
neurons, but showed a decrease over brain areas. For both, NR2C and NR2D, no
ethanol-related changes of mRNA expression were observed. A link between such
differential alterations in NR mRNA subunit expression and ethanol-induced
seizures in withdrawing alcoholics of the epsilon-type seems possible.
PMID- 10685879
TI - Selective inhibition of monoamine neurotransmitter transporters by synthetic
local anesthetics.
AB - Synthetic local anesthetics (LAs) have been found to have cocaine-like
characteristics with some psychotomimetic action, possibly through monoaminergic
neurotransmission. To gain insight into the relation between LA action and
monoamine transporters, we investigated the effect of synthetic LAs on
neurotransmitter transporters, including monoamine transporters. We used cloned
transporter cDNAs and examined transient functional expression in COS cells and
stable expression in HeLa cells. Among the LAs tested, procaine and other ester
type LAs inhibited [3H]DA uptake and binding of [3H]2-beta-carbomethoxy-3-beta-(4
fluorophenyl)tropane (CFT), a cocaine analogue, in COS cells expressing rat
dopamine transporter (DAT). The inhibition was concentration-dependent. The
inhibitory effect on [3H]DA uptake was reversible and not dependent on pH, as
observed in HeLa cells stably expressing DAT. Procaine also inhibited uptake of
norepinephrine (NE) and serotonin (5-HT) by the norepinephrine transporter (NET)
or serotonin transporter (SERT) expressed in COS cells. On the other hand,
procaine and other LAs had little or no effect on [3H]GABA and [3H]glutamate
uptake in COS cells expressing mouse GABA or rat glutamate/aspartate transporter.
IC50 values for [3H]DA uptake inhibition correlated well with those for [3H]CFT
binding inhibition, but not with intrinsic anesthetic potency. Kinetic analysis
of monoamine uptake inhibition by procaine in COS cells expressing rat DAT, NET
or SERT revealed a competitive action similar to that of cocaine. These results
demonstrate that certain LAs selectively inhibit monoamine transporters. This
might contribute to the cocaine-like psychotomimetic action of certain LAs.
PMID- 10685880
TI - An innovative method for rapid characterisation of phospholipase C activity:
SB242,084 competitively antagonises 5-HT2C receptor-mediated
[3H]phosphatidylinositol depletion.
AB - 6-chloro-5-methyl-1-[6-(2-methylpyridin-3-yloxy) pyridin-3-ylcarbamoyl] indoline
(SB242,084) is a novel, selective 5-HT(2C) receptor antagonist, but its actions
at these sites have been little characterised at the cellular level. We employed
a rapid and innovative approach to investigate its functional activity at
phospholipase C (PLC)-coupled human 5-HT(2C) receptors expressed in CHO cells.
PLC activity was determined as a decrease in the [3H]phosphatidylinositol
([3H]PI) content of cell membranes. Serotonin (5-HT) stimulated [3H]PI depletion
(pEC50=8.74), and SB242,084, like mesulergine, completely reversed this action of
5-HT (pK(B)=9.25 and 9.01, respectively). Further, in Schild analysis, SB242,084
behaved as a high affinity competitive antagonist, inducing a parallel, rightward
displacement of the 5-HT stimulation isotherm without loss of maximum efficacy.
The pA2 of 9.50 was similar to its binding affinity (pKi=9.38). SB242,084 also
displayed antagonist properties when PLC activity was examined by conventional
determination of [3H]inositol phosphate generation. Employing this parameter, the
potency of SB242,084 (pK(B)=9.21) and that of mesulergine (pK(B)=9.06) closely
resembled those determined by [3H]PI depletion. In conclusion, determination of
[3H]PI depletion constitutes a useful and novel technique to characterise agonist
and antagonist properties of ligands at PLC-coupled receptors.
PMID- 10685881
TI - Efficacy of synthetic zeolite to reduce the toxicity of aflatoxin in broiler
chicks.
AB - Synthetic zeolites (NaX, NaY, NaA, and CaA) were evaluated in vitro for their
ability to sorb aflatoxin (AF) B1 from an aqueous solution. Zeolite NaA (ZN) was
selected to be tested in vivo because of its high affinity and its stable
association with AFB1. This sorbent was incorporated into diets (1%) containing
2.5 mg/kg AFB1. Male broiler chicks from 21 to 42 d of age received ad libitum
access to their respective diets and water. When compared with controls, BW gains
were lower (P < 0.05) for broilers that were fed AF in their diets. No
differences were found between the BW gains of chicks fed diets without AF and
those of chicks fed AF + ZN, indicating almost total protection against the
effects caused by AF. Liver weights were considerably higher in chicks fed a diet
containing AF, compared with those of controls, nevertheless, no significant
differences were found in feed:gain ratio among the groups. The findings of this
research suggest that ZN can counteract some of the toxic effects of AF in
growing broiler chicks.
PMID- 10685882
TI - Lactobacillus flora in the cloaca and vagina of hens and its inhibitory activity
against Salmonella enteritidis in vitro.
AB - Lactobacilli in the cloaca and vagina of 40 normal laying hens were investigated
quantitatively and qualitatively, and their ability to inhibit growth of
Salmonella enteritidis (SE) was examined using a spot-the-lawn technique. All
samples of cloacal contents and half the samples of vaginal mucus were positive
for lactobacilli. The means +/- SD of total Lactobacillus counts in the cloaca
and those in the vagina were log10 5.5 +/- 1.1 and 2.5 +/- 2.6 cfu/g,
respectively. In the cloaca, Lactobacillus acidophilus was isolated from 92.5% of
hens, and Lactobacillus salivarius was isolated from 85.0% of hens, whereas
Lactobacillus fermentum was isolated from only one hen. In the vagina, L.
acidophilus and L. salivarius were isolated from 42.5% of hens. In the inhibition
assay in vitro, all strains of Lactobacillus from cloacal contents and vaginal
mucus inhibited growth of SE. There was a wide range of the inhibitory activity
even in the same species. No difference of the growth inhibition zone was
observed between lactobacilli from cloaca and those from vagina. The present
study suggested that lactobacilli in the cloaca and vagina of hens might have a
protective effect against SE colonization.
PMID- 10685883
TI - Efficacy of neomycin sulfate water medication on the control of mortality
associated with colibacillosis in growing turkeys.
AB - The objective of this investigation was to evaluate the efficacy, safety, and
toxicity of neomycin sulfate (Neomix 325) water medication to control mortality
associated with colibacillosis (Escherichia coli) in growing turkeys. One
efficacy trial was conducted at five locations; each location included 2,880
sexed 21-d-old turkey poults that were naturally challenged with litter from
turkey flocks that had colibacillosis. Between 5 and 7 d after challenge, and
when mortality had reached 0.5%, poults were randomized within sex into three
treatment groups of 0, 11, or 22 mg neomycin sulfate/kg body weight. In each
location, each treatment was replicated 12 times with 40 poults per sex per
replicate. All treatments were administered in the drinking water for 5 d. The
pivotal decision criterion was mortality. Mortality was defined as 1) supported
mortality (SM): positive microbial culture for E. coli and gross lesions, 2)
diagnosed mortality (DM): diagnosed as associated with E. coli but not supported
by lesions or positive microbiological cultures, 3) overall mortality (OM):
mortality associated with E. coli or other microorganisms and miscellaneous
reasons such as accidents (trampling or suffocations). Performance data (growth
and feed utilization) also were measured and are reported without statistical
analysis. Results from this efficacy study clearly demonstrated the effectiveness
of neomycin sulfate against E. coli as measured by a reduction in mortality. In
the target animal safety and toxicity study (done in conjunction with the
efficacy study), neomycin sulfate in the drinking water at 66, 110, or 220 mg/kg
per d for 15 d had no observable adverse effects on poult performance, as
measured by feed or water consumption, body weight, gross pathology, or
mortality.
PMID- 10685884
TI - Effects of photoperiod and melatonin on lymphocyte activities in male broiler
chickens.
AB - Understanding the role of the pineal gland in regulating the immune response and
the role of photoperiod in influencing pineal gland secretions are becoming
increasingly important. The purposes of the present experiments were to
investigate the effects of different photoperiod regimens on T- and B-lymphocyte
activities in broiler chickens. Next, the influence of different photoperiod
regimens on the responsiveness of lymphocytes to melatonin in vitro was examined.
The effect of melatonin in vitro on lymphocyte activities was also studied,
regardless of the photoperiod received. Finally, the effects of photoperiod on
the profiles of different splenocyte cell types were investigated. To study the
effect of photoperiod on lymphocyte activities, different photoperiod regimens
were used. These were: constant lighting, 23 h light:1 h darkness; intermediate
lighting, 12 h light:12 h darkness; and intermittent lighting, 1 h light:3 h
darkness. Peripheral blood and splenic lymphocyte activities were tested at 3 and
6 wk of age by performing a mitogen cell-proliferation assay with a polyclonal T
cell mitogen, concanavalin A (Con A), and T-dependent B-cell mitogen, pokeweed
mitogen (PWM). To study the effect of photoperiod on the responsiveness of
lymphocytes to melatonin in vitro or the effect of melatonin in vitro on
lymphocyte activities regardless of photoperiod received, lymphocytes from the
chickens that were exposed to the different photoperiod regimens were incubated
with mitogen and different concentrations of melatonin. To study the effect of
photoperiod on profiles of different cell types, the percentages of splenocyte
subpopulations from birds exposed to different photo-periods were determined
using flow cytometry with CD4+, CD8+, CD3+, and B-cell markers. The results of
these studies indicate that splenic T and B lymphocytes from 6-wk-old chickens
grown in intermittent lighting had higher activities than those from chickens
grown in constant lighting. Peripheral blood and splenic lymphocytes from
chickens raised under constant lighting were more responsive to melatonin in
vitro than those from chickens raised under intermittent lighting. This
difference in response may be due to lower levels of melatonin in birds receiving
constant lighting, making them more sensitive to melatonin in vitro. Melatonin in
vitro enhanced the mitogenic response of peripheral blood T lymphocytes from 6-wk
old chickens, splenic T lymphocytes from 3-wk-old chickens, and splenic T and
possibly B lymphocytes from 6-wk-old chickens. Finally, intermittent lighting
increased the percentages of splenic CD4+, CD8+, and CD3+ cells but not B-cell
subpopulations at 6 wk of age, presumably because of increased levels of
melatonin in birds receiving intermittent lighting. Our results re-emphasize the
importance of melatonin in regulating host immune response; this regulation could
be accomplished through exposing broiler chicks to intermittent lighting.
PMID- 10685885
TI - Effects of moniliformin on performance and immune function of broiler chicks.
AB - Three trials were conducted to evaluate the effect of moniliformin (M) on
performance and immune function in chicks. Day-old chicks were randomly assigned
to four dietary treatments (0, 50, 75, or 100 mg M/kg diet). In Trial 1, chicks
were placed on treatments for 3 wk and were injected intravenously with 4.6 x
10(6) Escherichia coli on Day 21. Blood samples were collected at 60, 120, and
180 min after inoculation, and liver, spleen, and lung were collected at 180 min
postinjection. Compared with control chicks, chicks fed 75 and 100 mg M/ kg diet
had higher (P < 0.05) numbers of E. coli colonies in the circulation, liver, and
spleen. In Trial 2, chicks were placed on diets for 4 wk and were injected with
0.5 mL Newcastle disease virus (NDV) vaccine intramuscularly on Weeks 2 and 3 of
the experiment. The primary and secondary anti-NDV antibody titers were measured
7 d after each injection. Chicks fed 100 mg M/kg diet had lower (P < 0.05)
secondary antibody titers than did control chicks. In Trial 3, lymphocyte
proliferation in chicks exposed to M in vivo and in vitro was determined. Results
of the in vivo study showed that cell proliferation in response to mitogens from
control- and M-fed chicks did not differ (P > 0.05). For the in vitro study,
lymphocyte proliferation decreased linearly (P < 0.01) with increased
concentrations of M. In all three trials, chicks fed 100 mg M/kg diet had lower
(P < 0.05) feed intake and weight gain than did control chicks. Data from the
current study suggested that M decreased performance and immune response in
chicks at the level of 75 mg/kg diet.
PMID- 10685886
TI - Effects of Salmonella typhimurium lipopolysaccharide on broiler chickens.
AB - The effects of Salmonella typhimurium lipopolysaccharide (LPS) on the physiology
of 3-wk-old broiler chickens were studied at 12, 24, and 48 h after a single
intravenous injection of saline or LPS. Lipopolysaccharide elevated cloacal
temperature by 3 h after injection, induced a diuretic response, and decreased BW
gain. An increase in the relative liver weight was evident in LPS-treated birds
at all time intervals, whereas a decrease in the relative weight of bursa of
Fabricius was observed only at the 48-h time point. The plasma interleukin (IL)-6
and the blood heterophil concentrations were elevated at 12 and 24 h following
LPS administration. These changes were not observed in control chickens or in LPS
treated chickens at 48 h. A decrease in the blood glucose concentration in LPS
treated birds at 12 h was accompanied by an elevation in the blood phosphate
level. An increase in total plasma protein concentration was observed only at 24
and 48 h after LPS treatment. Comparative SDS-PAGE analysis of plasma proteins
from these birds under nonreducing conditions showed some quantitative
differences in four bands of proteins between saline and LPS-treated chickens. A
protein corresponding to an approximate molecular weight (MW) of 65 kDa increased
in LPS-treated chickens, and three other proteins with MW of approximately 39,
49, and 56 kDa showed reductions in concentration compared with saline-treated
controls. These results show that LPS induces a number of physiological changes
that may be responsible for the regulation of the acute phase response in
chickens.
PMID- 10685887
TI - Chicken intestinal aminopeptidase: partial sequence of the gene, expression and
activity.
AB - Aminopeptidases are members of a membrane-bound metallopeptidase family that are
expressed at a high level on the brush-border membrane of enterocytes. Because
the rapid growth of meat-type chickens depends on the dietary supply of amino
acids, a study of intestinal aminopeptidases, which play a central role in
protein digestion, is important. This study is the first reported isolation of
the partial cDNA of chicken intestinal aminopeptidase and sequencing of a 1.7-kb
cDNA fragment. The gene was isolated by reverse transcriptase polymerase chain
reaction using six primers chosen from conserved regions of the aminopeptidase
genes. Amplified fragments were extracted from the gel, purified, and sequenced.
By using this chicken cDNA as a probe, northern blot analysis revealed a
transcript of approximately 3.5 kb in the chicken duodenum, jejunum, and ileum
tissues. Higher RNA expression and activity of aminopeptidase were found in the
ileum tissue compared with the duodenum and jejunum segments.
PMID- 10685888
TI - Autosomal albino chicken mutation (ca/ca) deletes hexanucleotide (
deltaGACTGG817) at a copper-binding site of the tyrosinase gene.
AB - We compared tyrosinase cDNA sequences from a line of autosomal albino and Black
Silky chickens isolated from cultured melanocytes by reverse transcription
polymerase chain reaction (RT-PCR). Both sources produce a single DNA fragment of
predicted normal tyrosinase size. Direct sequencing of the PCR product showed
three mutated sites in the tyrosinase gene of the albino chicken. Two silent
point mutations and a deletion of six nucleotides (-deltaGACTGG) at 817 bp in the
tyrosinase cDNA sequence were observed when compared with the White Leghorn and
Black Silky cDNA sequences. The deduced albino chicken tyrosinase protein lacks
two amino acids, aspartic acid and tryptophan. The position of these amino acids
is consistent with one of the potential copper-binding sites that should be
indispensable for function of the enzyme. We speculate that the six-base deletion
is responsible for the inactive tyrosinase in this line of albino chickens.
PMID- 10685889
TI - Incorporation of different polyunsaturated fatty acids into eggs.
AB - An experiment was carried out to examine thoroughly the relationships among
different n-3 and n-6 polyunsaturated fatty acids (PUFA) in the diet, their
deposition into the eggs' fat, and their effect on hens' laying performance. A
diet enriched with 4% fish oil (FO) was fed to the birds throughout the 14-wk
laying period (Treatment 1; T1); this was the same oil source that was replaced
in proportions of 25, 50, 75, or 100% with four different fat sources, resulting
in 17 isocaloric dietary treatments: linseed oil (LO; T2 to T5), rapeseed oil
(RO; T6 to T9), sunflower oil (SO; T10 to T13), and tallow (T; T14 to T17).
Performance parameters were recorded weekly and analyzed on the basis of the
replacing fat source. At the end of the 14-wk experimental period, eggs were
collected, and their fatty acid (FA) profile was determined. Performance
parameters were not significantly different among grouped treatments. Smaller
proportions of FO in diets resulted in lower values of saturated and higher
values of n-6 FA contents, regardless of the fat source used when replacing FO.
The n-6 content increased mostly because of the rise in linoleic acid (LA),
although the level of arachidonic acid (AA) was always higher when FO was
completely suppressed. The amount of the different n-3 long-chain PUFA was lower
(P < 0.001) when FO was present in lesser proportions in the diet. However, the
slope of the decline of these FA changed according to the included fat. Replacing
FO with LO resulted in the lowest decline of its derivatives by elongation and
desaturation and an increase in the total n-3 FA in the form of linolenic acid
(LNA).
PMID- 10685890
TI - The effect of dietary betaine in Eimeria acervulina-infected chicks.
AB - Two experiments were conducted to evaluate the effect of dietary betaine in
broiler chicks with either chronic (CHR; 2.5 x 10(5) sporulated oocysts on Day 1,
4, 7, and 10) or acute (ACT; 1.0 x 10(6) sporulated oocysts on Day 1) Eimeria
acervulina infections. Three hundred (Experiment 1) or 600 (Experiment 2), 4-d
old male chicks were used in the 14-d experiments. In both experiments, a 2 x 3
factorial arrangement of treatments was used: two levels of betaine (0 or 0.075%)
and three levels of coccidiosis infection (uninfected, CHR, or ACT). Each
treatment was replicated five (Experiment 1) or 10 (Experiment 2) times with 10
chicks per replicate. In Experiment 1, the ACT infection decreased (P < 0.01)
average daily gain and gain:feed, and the CHR infection decreased (P < 0.02)
average daily gain. The ACT and CHR infections decreased (P < 0.06) Day 7 plasma
carotenoids and Day 14 plasma total protein, and the ACT infection also decreased
(P < 0.06) Day 7 plasma total protein. Average daily gain and Day 7 plasma total
protein were increased in CHR chicks fed betaine but were decreased in uninfected
chicks fed betaine (CHR x betaine; P < 0.09). Chicks fed betaine had decreased (P
< 0.06) Day 7 plasma carotenoids. In Experiment 2 the CHR and ACT infections
decreased (P < 0.01) average daily gain, average daily feed intake, grain:feed
ratio, Days 7 and 14 plasma carotenoids, and Day 7 plasma total protein. Chicks
fed betaine had increased (P < 0.07) average daily gains, gain:feed ratios, and
lesion scores. Day 14 plasma carotenoids and plasma total protein were decreased
in uninfected chicks fed betaine but were increased in CHR chicks fed betaine
(CHR x betaine; P < 0.04); plasma carotenoids also were increased in ACT chicks
fed betaine (ACT x betaine; P < 0.05). Betaine did not consistently affect growth
performance, plasma constituents, or lesion score in CHR or ACT coccidiosis
infected chicks.
PMID- 10685891
TI - Effects of phosphorolytic and cell wall-degrading enzymes on the performance of
growing broilers fed wheat-based diets containing different calcium levels.
AB - A study was conducted to determine the cumulative effects of phosphorolytic
enzymes, cell wall-degrading enzymes, and citric acid and Ca levels on feed
intake, BW gain (BWG), feed conversion, intestinal viscosity, and toe ash of
broilers (d 1 to 21) fed wheat-based diets. Broilers were fed the following six
diets at either 0.59, 0.69, or 0.79% Ca: 1) a negative control (NC) diet, 0.17%
available P; 2) NC + 750 phytase units/kg diet; (3) phytase + 3,156 units of acid
phosphatase/kg diet; 4) phytase + acid phosphatase + 1,900 units of pectinase/g
diet; 5) phytase + acid phosphatase + pectinase + 3% citric acid; and (6) NC plus
0.24% available P. The 18 dietary treatments were fed to four pen replicates of
eight birds each. Phytase addition at the low Ca level increased BWG, improved
feed intake and conversion and toe ash, and reduced intestinal viscosity and
ileal length. Subsequent addition of acid phosphatase, at 0.69% Ca, resulted in
increases in BWG, 42%; feed intake 32%; feed conversion 7.5%; and toe ash, 63%
over the NC diet. Pectinase addition produced further improvements in 21-d BWG
and feed intake at 0.59 and 0.79% Ca, increased toe ash in chicks fed 0.79% Ca,
and reduced intestinal viscosity. Supplementation of wheat-based 0.17% available
P diets with phytase and acid phosphatase and with appropriate concentrations of
pectinase, citric acid, and Ca significantly improved BWG, feed intake and
conversion and intestinal viscosity over the 0.41% available P diets. Bone
mineralization of chicks fed phytase + acid phosphatase and 0.69% Ca and those
fed phytase + acid phosphatase + pectinase + citric acid and 0.59% Ca was similar
to that of chicks fed the 0.41% available P diets.
PMID- 10685892
TI - Research notes: The effect of different levels of palm kernel meal in layer
diets.
AB - Palm kernel meal (PKM), a by-product from the African Palm oil industry that is
extensively cultivated in tropical countries, is an interesting feed ingredient
for poultry due to its availability and low cost. The objective of this study was
to evaluate the use of different levels of PKM in layer diets. This particular
PKM contained 9.70% crude protein, 0.20% methionine, 0.36% lysine, and a TMEn
value of 2,254 kcal/kg. A control diet based on corn and soybean meal and five
different levels of PKM added to it were fed to Single Comb White Leghorn hens
from 18 to 38 wk of age. The PKM levels were 0, 10, 20, 30, 40, and 50%. The hens
were housed three per cage (30.5 cm wide x 45.7 cm deep). The six treatments were
assigned randomly to three contiguous cages in each of eight rows in a randomized
complete block design. Egg production was recorded daily, and feed consumption
for an entire week was recorded every 21 d. Egg weight and specific gravity were
recorded for 3 consecutive d every 21 d. Mortality was recorded daily. Results
show that egg production was significantly decreased (P < 0.05) only with 50% PKM
in the diet. Feed conversion was not affected by any level of PKM. Specific
gravity was slightly but significantly (P < 0.05) decreased by all levels of
added PKM. Feed consumption, mortality, and egg weight did not differ
significantly among the treatments. We concluded that this particular PKM may be
used up to 40% in the diet, taking into account that specific gravity may be
slightly decreased.
PMID- 10685893
TI - Soluble factors and the emergence of chick primordial germ cells in vitro.
AB - Previous observations obtained from a culture of blastodermal cells on a mouse
fibroblast feeder layer (STO) suggested that STO cells provide a factor or
factors that facilitate development of avian primordial germ cells (PGC) from
dispersed embryo cells. The purpose of the current study was to test the
hypothesis that soluble factors produced by STO cells are responsible, at least
in part, in supporting the development of PGC in culture and to examine the
effect of stem cell factor (SCF), ciliary neurotrophic factor (CNTF), and basic
fibroblast growth factor (bFGF) in the development of PGC in culture.
Blastodermal cells on gelatin-coated plastic or on feeder layers of CV-1 cells
yielded a small number of PGC. When blastodermal cells were cultured on STO
cells, a marked increase in PGC was observed. The addition of STO cell
conditioned medium (STO-CM) to blastodermal cells cultured on gelatin-coated
plastic and on feeder layers of CV-1 cells resulted in a significant increase in
the number of PGC, indicating that soluble factors produced by STO cells can
enhance the development of chicken PGC in culture. Supplementation of
blastodermal cells with SCF (100 ng/mL) or CNTF (2 ng/mL) or with CNTF and SCF
together resulted in a significant increase in the number of PGC after 48 h of
culture on feeder layers of CV-1 cells. However, addition of bFGF (100 ng/mL) did
not increase PGC. We concluded from these observations that the culture of
blastodermal cells on feeder layers of STO and CV-1 cells can be used as a useful
biological system in examining the regulatory factors that govern the ontogeny of
the germ cell lineage in the avian embryo.
PMID- 10685894
TI - Ultrastructure of spermatozoa from Japanese quail.
AB - A monoclonal antibody (mAb) to epitopes on mitochondria from turkey spermatozoa
cross-reacted with Japanese quail spermatozoal mitochondria. However, the pattern
of binding was different from that observed for turkey sperm. The ultrastructure
of quail spermatozoa was examined to determine the reason for this difference in
antibody binding pattern. Light microscopy, as well as scanning (SEM) and
transmission (TEM) electron microscopy, were used to study the morphology of
spermatozoa from Japanese quail. Japanese quail had a sauropsid type of sperm
cell, which is typical of nonpasserine birds. The spermatozoa were vermiform in
shape, with a maximum width of 0.6 microm and an overall length between 230 and
250 microm. An acrosome (3.7 to 4.5 microm), nucleus (20.8 to 23.8 microm),
midpiece (160 to 170 micro/m), and tail (40 to 60 microm) were observed. The TEM
showed an acrosomal cap surrounding a perforatorium that inserted into the
nucleus at the posterior end. Only a distal centriole was observed, which gave
rise to a central axoneme with a 9+2 microtubular structure. The axoneme was
encased by a spiraled mitochondrial sheath in the midpiece region (64 to 74% of
the overall length of the sperm), and mitochondria numbers were estimated to be
greater than 1,400 per sperm. In contrast, turkey sperm contain short midpieces
with only 20 to 30 mitochondria per sperm. Differences in binding patterns of the
mAb to turkey mitochondria between quail and turkey sperm were due to the
presence of mitochondria on the exceptionally long midpieces of quail sperm.
PMID- 10685895
TI - Immunolocalization of progesterone and estrogen receptors in the sperm storage
tubules of laying and diethylstilbestrol-injected immature hens.
AB - The goal of this study was to determine whether sperm storage tubules (SST) in
the uterovaginal junction (UVJ) contain receptors for progesterone and estrogen
(PR and ER) and whether estrogenic stimulation induces activation of these
receptors in the SST. Frozen sections of UVJ obtained from immature chicks
treated with or without diethylstilbestrol (DES), which is an estrogenic
substance, and those from laying hens were immunostained for PR and ER. In laying
hens, immunoreactions for PR were observed in the SST cells and on the surface
epithelium of UVJ; the strongest reactions appeared in the SST cells. In
contrast, ER immunoreactions were localized in the SST cells but not in the other
cells. Immunoreactions for PR and ER were negligible in the UVJ of control
immature birds that received only the oil vehicle. However, in the DES-treated
birds, PR immunoprecipitates were localized in the surface epithelium and SST
cells, and there were ER in the SST cells. These results suggest that the SST
cells in the UVJ contain PR and ER, and estrogenic stimulation may play a
significant role in inducing activation of these receptors.
PMID- 10685896
TI - Effect of meat temperature on proteins, texture, and cook loss for ground chicken
breast patties.
AB - Soluble proteins, myofibrillar proteins, collagen, texture, and cook loss were
evaluated at different meat temperatures by heating ground and formed chicken
breast meat in brass containers in a water bath to temperatures of 40, 50, 60,
70, or 80 C. The soluble proteins decreased by approximately 90% as meat
temperature increased from 23 to 80 C. The myofibrillar protein subunits of
molecular weight greater than 43 kDa decreased with increasing temperature from
23 to 80 C as analyzed via SDS-PAGE. Amount of soluble collagen more than doubled
when meat temperature was increased from 50 to 70 C. The maximum peak shear force
was obtained, via Warner-Bratzler shear test, at 60 C for ground chicken breast
patties. The weight of patties decreased approximately 10.3% when meat
temperatures were increased from 23 to 80 C. Overall, heating temperature
affected the texture of the meat and caused changes in proteins and cook loss.
PMID- 10685897
TI - Denaturation of myofibrillar proteins from chickens as affected by pH,
temperature, and adenosine triphosphate concentration.
AB - The susceptibility to denaturation of myofibrillar protein from chicken muscles
was investigated and compared with denaturation of myofibrillar protein from
pork. Immediately postmortem, the Pectoralis profundus (white muscle) and the
Pubo-ishio femorale (red muscle) of six Arbor Acres chickens were collected. The
Semimembranosus (white muscle) and Psoas major (red muscle) of three Yorkshire x
Landrace and three Yorkshire x Landrace x Duroc pigs were collected at 45 min
postmortem. Protein denaturation was prevented by keeping the muscles at 0 to 2 C
in a buffer (pH 7.2) containing ethylene glycol-bis (beta-aminoethyl ether)
N,N,N',N'-tetraacetic acid (EGTA) (to sequester Ca ions). After purification,
myofibrils were incubated at 25 or 40 C, pH 5.4 or 6.5, with 0, 0.68, or 3.4 mM
adenosine triphosphate (ATP). Protein solubility, an indicator of denaturation,
was assessed after 0, 10, 20, and 60 min incubation. Protein solubility of
chicken pectoralis myofibrils was not affected by any of the conditions. In the
other myofibrils, pH 5.4 caused significantly (P < 0.05) more protein
denaturation than pH 6.5, and incubation at 40 C resulted in significantly more
protein denaturation than incubation at 25 C. The presence of ATP (tested at pH
6.5) affected denaturation; higher ATP concentrations resulted in increased loss
of solubility. We concluded that chicken red myofibrillar proteins are equally
susceptible to denaturation as are pork red and white myofibrils. Chicken
pectoralis (white) muscle fibers are least susceptible to denaturation. The
results of this study indicate that factors other than protein denaturation are
responsible for the low water-holding capacity of pale, soft, exudative chicken
breast muscle.
PMID- 10685898
TI - Histological characterization of hemorrhages in muscles of broiler chickens.
AB - Hemorrhages in meat of broiler chickens are major quality defects. The objective
of our study was to characterize the various types of hemorrhages in thigh and
breast muscles with respect to their morphological appearance, location, and
origin. Chickens were stunned using a water-bath stunner and were either
exsanguinated and fixed or perfused with fixative. The morphological appearance
of the hemorrhages was determined by the type of tissue in which they were found
and by the amount of extravasating blood. Origins of hemorrhages were found only
at sites of rupture of venous structures, such as postcapillary venules and small
collecting veins. The absence of significant leukocyte infiltration strongly
indicated that muscle tissue damage and hemorrhage occurred within the 24 h
preceding stunning and slaughter. The locations and types of hemorrhages indicate
different underlying mechanisms.
PMID- 10685899
TI - Thermal gelation properties of spent hen mince and surimi.
AB - Thermal gelation properties of spent hen mince and surimi were investigated. The
mince from 98-wk-old spent hens was washed two times with 0.1% NaCl. A portion of
unwashed and washed mince was mixed with 4% sugar, 4% sorbitol, and 0.2% Na
tripolyphosphate to produce surimi and was kept frozen at -20 C. The mince and
surimi were ground with 3% NaCl and a small amount of water to adjust the final
moisture content to 80%. A 6 to 8% potato starch was mixed with some pastes. The
pastes were stuffed into sausage casings and heated by one-step and two-step
heating. The effects of washing, heating, and addition of ingredients on the
color, composition, and functional properties of the mince and gel were compared.
Washed, spent hen mince was lighter and less red in color and higher in collagen,
gel strength, water-holding ability, and cooking yield than unwashed mince. The
best temperature and time schedule for the gelation of spent hen mince was 90 C
for 15 min in one-step heating. Heating at 100 C for 5 min after preheating at 60
to 70 C for 30 min resulted a gel with distinctly improved gel strength. Sucrose
(4%), sorbitol (4%), and Na-tripolyphosphate (0.2%) improved the gel quality of
nonfrozen mince but showed little cryoprotective effect against the degradation
of frozen-stored product. A 6% potato starch improved the gel texture, cooking
yield, and water-holding ability compared with 8% starch.
PMID- 10685900
TI - Quality and sensory characteristics of selected post-rigor, early deboned broiler
breast meat tenderized using hydrodynamic shock waves.
AB - Our first objective was to determine the effects of explosive amount and distance
of the explosive to the meat surface in the Hydrodyne process on broiler breast
tenderness. Early deboned (EB) breasts were removed immediately after initial
chill (45 min postmortem), stored for 24 h (4 C), and subjected to one of four
Hydrodyne treatments (200 g at 20 cm, 350 g at 23 cm, 275 g at 20 cm, or 350 g at
20 cm). Breasts were water-cooked (78 C internal). Hydrodyne treatment (HYD) of
350 g at 20 cm produced the greatest reduction (28.3%) in Warner-Bratzler shear
(WBS, 1.9-cm wide strips). This combination was the only treatment to improve
tenderness (peak force 4.3 kg) to a level equivalent (P > 0.05) to aged controls
(CA; peak force 3.1 kg). The second objective was to determine the quality and
sensory characteristics of Hydrodyne-treated (350 g explosive at 20 cm) broiler
breasts as compared with CA and EB. The WBS values (1.0-cm wide and thick strips)
for CA (1.56 kg) were different from both HYD (3.7 kg) and EB breasts (4.7 kg).
The CA resulted in more tender, flavorful, and juicer breasts than EB and HYD.
The EB was higher in initial moisture release than HYD. The EB breasts with
tenderness problems can be tenderized by the Hydrodyne process based on WBS
results. However, higher levels of explosive may be required to optimize the
tenderness improvement of EB breasts that vary significantly in initial
tenderness.
PMID- 10685901
TI - Cardiac natriuretic peptides: a physiological lineage of cardioprotective
hormones?
AB - Vertebrate hearts from fish to mammals secrete peptide hormones with profound
natriuretic, diuretic, and vasodilatory activity; however, the specific role of
these cardiac natriuretic peptides (NPs) in homeostasis is unclear. NPs have been
suggested to be involved in salt excretion in saltwater teleosts, whereas they
are proposed to be more important in volume regulation in mammals. In this
review, we consider an alternative (or perhaps complementary) function of NPs to
protect the heart. This hypothesis is based on a number of observations. First,
evidence for NPs, or NP-like activity has been found in all vertebrate hearts
thus far examined, from osmoconforming saltwater hagfish to euryhaline freshwater
and saltwater teleosts to terrestrial mammals. Thus the presence of cardiac NPs
appears to be independent of environmental conditions that may variously affect
salt and water balance. Second, cardiac stretch is a universal, and one of the
most powerful, NP secretagogues. Furthermore, stretch-induced NP release in
euryhaline teleosts appears relatively independent of ambient salinity. Third,
excessive cardiac stretch that increases end-diastolic volume (EDV) can
compromise the mechanical ability of the heart by decreasing actin-myosin
interaction (length-tension) or through Laplace effects whereby as EDV increases,
the wall tension necessary to maintain a constant pressure must also increase.
Excessive cardiac stretch can be produced by factors that decrease cardiac
emptying (i.e., increased arterial pressure), or by factors that increase cardiac
filling (i.e., increased blood volume, increased venous tone, or decreased venous
compliance). Fourth, the major physiological actions of cardiac NPs enhance
cardiac emptying and decrease cardiac filling. In fish, NPs promote cardiac
emptying by decreasing gill vascular resistance, thereby lowering ventral aortic
pressure. In mammals a similar effect is achieved through pulmonary vasodilation.
NPs also decrease cardiac filling by decreasing blood volume and increasing
venous compliance, the latter producing a rapid fall in central venous pressure.
Fifth, the presence of NP clearance receptors in the gill and lung (between the
heart and systemic circulation) suggest that these tissues may be exposed to
considerably higher NP titers than are systemic tissues. Thus, a decrease in
outflow resistance immediately downstream from the heart may be the first
response to increased cardiac distension. Because the physiology of cardiac NPs
is basically the same in fish and mammals, we propose that the cardioprotective
effects of NPs have been well preserved throughout the course of vertebrate
evolution. It is also likely that the cardioprotective role of NPs was one of the
most primordial homeostatic activities of these peptides in the earliest
vertebrates.
PMID- 10685902
TI - Fecal glucocorticoids: a noninvasive method of measuring adrenal activity in wild
and captive rodents.
AB - To determine the utility of fecal corticosteroid concentration as a measure of
chronic stress under laboratory and field conditions, we biochemically and
physiologically validated a radioimmunoassay for corticosteroids in three rodent
species, house mice (Mus musculus), deer mice (Peromyscus maniculatus), and red
back voles (Clethrionomys gapperi). The biochemical validations demonstrated that
the assay accurately and precisely measured corticosteroid concentration in the
feces. The physiological validation indicated that the assay was sensitive enough
to detect the stress associated with (a) brief handling and bleeding of animals,
(b) chronic caloric restriction, (c) exposure to a novel environment, and (d)
exposure to a novel cold environment. Our results suggest that fecal measurements
reflect stress levels experienced by these animals approximately 6-12 h before
defecation. Therefore, given a judicious trapping and trap-monitoring protocol,
this assay has considerable utility for measuring the stress levels at which
animals actually exist in the field.
PMID- 10685903
TI - The ventilatory responses of the caecilian Typhlonectes natans to hypoxia and
hypercapnia.
AB - Typhlonectes natans empty their lungs in a single extended exhalation and
subsequently fill their lungs by using a series of 10-20 inspiratory buccal
oscillations. These animals always use this breathing pattern, which effectively
separates inspiratory and expiratory airflows, unlike most urodele and anuran
amphibians that may use one to many buccal oscillations for lung inflation and
typically mix expired and inspired gases. Aquatic hypoxia had no significant
effect on the breathing pattern or mechanics in these animals. Aerial hypoxia
stimulated ventilatory frequency and increased the number of inspiratory
oscillations but had little effect on inspiratory and expiratory tidal volume.
Aquatic hypercapnia elicited a large significant increase in air-breathing
frequency and minute ventilation compared to the small stimulation of minute
ventilation seen during aerial hypercapnia. Some animals responded to aquatic
hypercapnia with a series of three or four closely spaced breaths separated by
long nonventilatory periods. Overall, T. natans showed little capacity to
modulate expiratory or inspiratory tidal volumes and depended heavily on changing
air-breathing frequency to meet hypoxic and hypercapnic challenges. These
responses are different from those of anurans or urodeles studied to date, which
modulate both the number of ventilatory oscillations in lung-inflation cycles and
the degree of lung inflation when challenged with peripheral or central
chemoreceptor stimulation.
PMID- 10685904
TI - Maximum daily energy intake: it takes time to lift the metabolic ceiling.
AB - Conventionally, maximum capacities for energy assimilation are presented as daily
averages. However, maximum daily energy intake is determined by the maximum
metabolizable energy intake rate and the time available for assimilation of food
energy. Thrush nightingales (Luscinia luscinia) in migratory disposition were
given limited food rations for 3 d to reduce their energy stores. Subsequently,
groups of birds were fed ad lib. during fixed time periods varying between 7 and
23 h per day. Metabolizable energy intake rate, averaged over the available
feeding time, was 1.9 W and showed no difference between groups on the first day
of refueling. Total daily metabolizable energy intake increased linearly with
available feeding time, and for the 23-h group, it was well above suggested
maximum levels for animals. We conclude that both intake rate and available
feeding time must be taken into account when interpreting potential constraints
acting on animals' energy budgets. In the 7-h group, energy intake rates
increased from 1.9 W on the first day to 3.1 W on the seventh day. This supports
the idea that small birds can adaptively increase their energy intake rates on a
short timescale.
PMID- 10685905
TI - Seasonal thermogenic acclimation of diurnally and nocturnally active desert spiny
mice.
AB - Diurnally active golden spiny mice (Acomys russatus) and nocturnal common spiny
mice (Acomys cahirinus) coexist in hot rocky deserts of Israel. Diurnal and
nocturnal activities expose these species to different climatic conditions.
Nonshivering thermogenesis (NST) capacity of individuals of both species
immediately upon removal from the field exhibited seasonal changes, with no
significant interspecific difference. Colony-reared mice of either species
transferred in the laboratory from long to short photoperiod increased NST
capacity, though to a lesser extent than observed in the seasonal
acclimatization. The underlying biochemical mechanisms of short photoperiod
acclimation differed between the species. In both Cytochrome-c oxidase (Cox)
activity was higher in short as compared to long photoperiod. In short
photoperiod-acclimated A. cahirinus uncoupling protein (UCP) content in brown
adipose tissue (BAT) was significantly higher than in long photoperiod, while in
A. russatus there was no significant change. In A. russatus there was a
significant increase in lipoprotein lipase (LPL) activity in BAT in short
photoperiod-acclimated individuals, while in A. cahirinus LPL activity was high
under both acclimations. The low LPL activity in brown adipose tissue of desert
adapted A. russatus may facilitate lipid uptake in white adipose tissue, an
advantage in desert conditions where food is scarce and irregularly distributed
in space and time.
PMID- 10685906
TI - Effect of a low-Fat diet on body composition and blubber fatty acids of captive
juvenile harp seals (Phoca groenlandica).
AB - We investigated the effects of a change from a high-fat diet to a low-fat diet of
differing fatty acid (FA) composition on the body composition and blubber FA of
five captive juvenile harp seals. Seals that had been maintained for 1 yr on a
diet of Atlantic herring (>/=9% fat) were switched to a diet of Atlantic pollock
(1. 7% fat) for 30 d. On days 0, 14, and 30, mass and body composition (using
isotope dilution) were measured, and blubber biopsies (5 cmx6 mm) were taken for
FA analysis. Fat accounted for 38%-49% of body mass at the start of the
experiment. When switched to the pollock diet, and despite food intakes averaging
6.5 kg/d (32.3 MJ/d), body fat declined by an average of 6.4 kg or by 32% over
the 30-d experiment. In contrast, body protein increased in direct relation to
protein intake (r2=0.836, P=0.030). Despite substantial loss of body fat, blubber
FA signature changed significantly to reflect the changes in dietary intake of
FA, and the deposition of FA was quantifiably predictable. Our results suggest
that young growing phocids are unable to maintain body fat stores on low-fat
diets even when protein intakes are high. This may have significant implications
for juvenile pinniped survival in the wild. In addition, turnover and deposition
of dietary FA in blubber takes place in nonfattening seals.
PMID- 10685907
TI - Effects of electromagnetic fields on the reproductive success of American
kestrels.
AB - Reduced reproductive success of birds nesting near power lines has been
documented but never directly attributed to electromagnetic fields (EMFs).
Laboratory studies have identified EMF effects on embryonic development, but
reproductive success of wild birds is dependent on additional factors, including
fertility, egg size, hatching, and fledging success. We tested whether EMFs
affect reproductive success of birds. Captive American kestrels (Falco
sparverius) were bred for one season per year for 2 yr under either controlled or
EMF conditions. EMF exposure was equivalent to that experienced by wild
reproducing kestrels and was weakly associated with reduced egg laying in 1 yr
only. In both years fertility was higher, but hatching success was lower in EMF
pairs than control pairs. Fledging success was higher in EMF pairs than control
pairs in 1995 only. Egg composition and embryonic development were examined in 1
yr only, but hatchlings were measured in both years. EMF eggs were larger, with
more yolk, albumen, and water, but had thinner egg shells than control eggs. Late
term EMF embryos were larger and longer than control embryos, although hatchlings
were similar in body mass and size. EMF exposure affected reproductive success of
kestrels, increasing fertility, egg size, embryonic development, and fledging
success but reducing hatching success.
PMID- 10685908
TI - Effects of diet on titratable acid-base excretion in grasshoppers.
AB - Despite the potential for diet to affect organismal acid-base status, especially
in herbivores, little is known about the effects of diet on acid-base loading and
excretion. We tested the effects of diet on acid-base loading and excretion in
grasshoppers by (a) comparing the fecal acid-base content of 15 grasshopper
species collected from the field and (b) comparing fecal acid-base excretion
rates of Schistocerca americana grasshoppers fed vegetable diets that differed in
their ashed and raw acid-base contents. The field experiments indicated that
grass-feeding species excrete fairly neutral fecal pellets, while forb/mixed
feeding species vary widely in their fecal acid-base contents. In the laboratory
experiment, acid-base excretion rates were positively correlated with dietary
ashed base intake rates but were not correlated with the acid-base content of
raw, unashed diet or feeding rate. These experiments suggest that some diets
could strongly challenge the acid-base homeostasis of herbivores; in some
grasshoppers, dietary acid-base loads could produce certainly lethal 1-unit
changes in average body pH within 6 h if they were not excreted.
PMID- 10685909
TI - Respiratory adaptations to running-water microhabitats in mayfly larvae Epeorus
sylvicola and Ecdyonurus torrentis, Ephemeroptera.
AB - The mayfly larvae Epeorus sylvicola and Ecdyonurus torrentis inhabit either fast
flowing or, for the latter species, calm zones of running water. We studied (1)
mechanisms and limitations of oxygen transport in single individuals (oxygen
consumption rate, occurrence and rate of gill movements, and heartbeats) in
running water of different oxygen concentrations and (2) capacities for
anaerobiosis (L-lactate production). Our aim was to look for specific adaptations
in the two species to slightly different microhabitats. Epeorus sylvicola, whose
immovable gills are not able to generate ventilatory convection, proved to be an
oxyconformer at both test temperatures (11 degrees and 15 degrees C). Ecdyonurus
torrentis showed a progressively stronger oxyregulatory behavior at higher
temperatures. In this species an onset of gill beating was found at moderate
hypoxia (below 16 kPa). Ventilating individuals reached maximum rates (300 min-1)
of 5-14 kPa. In the case of a further reduction of oxygen partial pressure, the
ventilatory rate started to decrease. Ventilatory activity, however, was
maintained down to very low oxygen concentrations. Neither in E. sylvicola nor in
E. torrentis was experimental evidence found to confirm the hypothesis of a
respiratory function of hindgut movements. During hypoxia, the heart rate was
constant in both species (E. sylvicola: 80 min-1; E. torrentis: 60 min-1):
bradycardia occurred either below 1.5 kPa or below 4 kPa. Anaerobiosis, that is,
lactate production, was not detected in either species.
PMID- 10685910
TI - Evolutionary history and adaptive significance of respiratory structures on the
legs of intertidal porcelain crabs, genus Petrolisthes.
AB - Semiterrestrial and terrestrial crabs have evolved multiple strategies for aerial
respiration. An uncommon strategy for aerial respiration is seen in porcelain
crabs, genus Petrolisthes, where decalcified areas on the meral segments of the
walking legs are used as respiratory structures. Here, the evolutionary history
and adaptive significance of these structures in porcelain crabs is examined.
Interspecific variation in leg membrane size is from 0% to 60% of the surface
area of the meral segment. Leg membrane relative size is positively correlated
with body size across species but not within one species, Petrolisthes cinctipes.
Phylogenetic analyses suggest that leg membranes are ancestral to one of two
eastern Pacific Petrolisthes clades. Comparative analyses using phylogenetic
independent contrasts indicate a relationship between leg membrane relative size
and body size that is phylogenetically independent. In large-bodied intertidal
species, whole-animal lactate accumulation during aerial incubation is 200%-300%
higher when the leg membranes are obscured, indicating that the leg membranes are
functional respiratory structures in these species. Thus, it is possible that leg
membranes have facilitated the evolution of larger body sizes by providing
additional respiratory surfaces to accommodate the associated higher metabolic
demands.
PMID- 10685911
TI - Diet explains interpopulation variation of plasma carotenoids and skin
pigmentation in nestling white storks.
AB - Carotenoids have a dietary origin in birds, but mechanisms by which they are
absorbed in the gut, transported in the blood, metabolized at various sites, and
deposited in the integument remain poorly understood. Variation in both plasma
carotenoid levels and external color may reflect different access to dietary
carotenoids or individual physiological differences in the uptake and deposition
of carotenoids. We compared total plasma carotenoid concentration in nestling
white storks (Ciconia ciconia) from 11 Spanish colonies in two consecutive years.
The main food item in one of the colonies was the red swamp crayfish (Procambarus
clarkii), a recently introduced species. Storks in the remaining colonies ate a
variety of foods but no crayfish. Total plasma carotenoid levels in the colony
where crayfish were consumed were about five times higher than in any other
colony. These differences were maintained after controlling for the significant
interyear variability, as well as for sex, age, and body mass of birds. Skin
pigmentation also differed, being intensely orange in storks that consumed
crayfish but white (unpigmented) in the remaining individuals. With thin-layer
chromatography (TLC) and electronic absorption spectroscopy, astaxanthin was
confirmed as the major carotenoid in crayfish as well as in the plasma, skin, and
body fat of crayfish-eating storks, whereas lutein was the main carotenoid in
plasma samples from the other colonies. These results indicate that a newly
available carotenoid in the environment, astaxanthin, can be absorbed in large
quantities from the gut and be transported in the blood before deposition in
different tissues.
PMID- 10685912
TI - The energy metabolism of common carp (Cyprinus carpio) when exposed to salt
stress: an increase in energy expenditure or effects of starvation?
AB - Stenohaline common carp (Cyprinus carpio) were chronically exposed to the two
main osmoregulatory ions, Na+ and Cl-, at levels close to their isoosmotic value
for 28 d (171 mM NaCl; 324 mosm kg-1; 10 per thousand). The aim of this study was
to assess whether or not the disturbed ion and osmoregulation affected the energy
demand and the energy stores of the exposed fish. Salt exposure reduced food
intake by 70% and had adverse effects on growth and survival. Although food
consumption decreased and growth was seriously affected, routine oxygen
consumption of the exposed fish did not drop, indicating a reallocation of energy
expenditure from growth toward other processes. A stress-induced increase in
plasma glucose was observed. As a result of low food intake, lower levels of
protein were used for fuel. Protein use itself was probably replaced by the use
of carbohydrates. These effects were confirmed by the depletion of both muscle
and liver glycogen stores during the experimental period. We conclude that,
besides the effects of reduced feeding, stress induced extra energy requirements
leading to the depletion of energy stores.
PMID- 10685913
TI - Effects of body mass and reproduction on the basal metabolic rate of brown long
eared bats (Plecotus auritus).
AB - We measured basal metabolic rate (BMR) of nonreproductive and of breeding
(pregnant and lactating) female brown long-eared bats (Plecotus auritus) to
investigate the effects of intra- and interindividual variation in body mass and
of reproduction on metabolism. The BMR of six nonreproductive females was
measured between five and seven times at approximately 2-wk intervals over a
period of 2.5 mo. There was a highly significant effect (P<0.001) of body mass on
BMR of these nonreproductive females. The pooled within-individual scaling
exponent (1.88) significantly exceeded the established mammalian interspecific
exponent (0.75). In addition, we made single observations on 14 nonreproductive
females to establish the effects of differences in mass between individuals. The
mean BMR across all 14 individuals was 82 mW (+/-24 SD). There was a significant
positive relationship between BMR and body mass across these individuals
(r2=0.39), with a between-individual scaling exponent of 0.75. Inter- and
intraindividual effects of mass on BMR were combined in a regression analysis
that included mean body mass and deviation from mean mass on any given day as
predictors. This regression model explained 55% of the variation in BMR. We made
longitudinal measurements of BMR throughout reproduction and compared these with
the predicted BMR of nonreproductive bats of the same body mass. Reproductive
females exhibited temporal flexibility in BMR. BMR during pregnancy increased on
a whole-animal basis but was significantly lower (by, on average, 15%) than BMR
predicted for nonreproductive females of the same mass. Over a period of 1-75 d
following birth, whole-animal BMR was greater than that during pregnancy, even
though body mass declined after parturition. Hence, postbirth BMR was greater
than the level predicted for nonreproductive females of the same mass. This study
indicates that the scaling of BMR with body mass differs significantly within and
between individuals and that there is a reduction of BMR in pregnancy and an
elevation of BMR during lactation.
PMID- 10685914
TI - How to choose delivery devices for asthma.
PMID- 10685915
TI - Pectus excavatum: studiously ignored in the United Kingdom?
PMID- 10685916
TI - Public health: Establishing an interagency equipment fund for children with
disabilities.
PMID- 10685917
TI - Stamps in pediatrics: Thalassaemia.
PMID- 10685918
TI - Controversy: Is the Children Act failing severely abused and neglected children?
PMID- 10685919
TI - Is routine growth monitoring effective? A systematic review of trials.
AB - BACKGROUND: Growth monitoring consists of routine measurements to detect abnormal
growth, combined with some action when this is detected. It aims to improve
nutrition, reduce the risk of death or inadequate nutrition, help educate carers,
and lead to early referral for conditions manifest by growth disorders. As
primary care workers world wide invest time in this activity, evidence for its
benefits and harms was sort. INCLUSION CRITERIA: STUDIES: randomised or quasi
randomised controlled trials of growth monitoring. INTERVENTIONS: regular growth
monitoring, combined with some intervention targeted at abnormal growth, compared
with controls. OUTCOMES: anthropometric measures; referrals to primary and
specialist care, or community services; maternal knowledge, anxiety, and
satisfaction; child morbidity and mortality. COMPARISONS: Routine growth
monitoring compared with no routine growth monitoring; routine growth monitoring
by plotting onto a standard chart compared with monitoring with no chart. SEARCH
STRATEGY: Cochrane controlled trials register; World Health Organisation and
World Bank publications; contact with specialist community paediatricians working
in the field. RESULTS: Two trials met the inclusion criteria. One compared growth
monitoring with no growth monitoring, in a cluster randomised trial nested in a
nutritional intervention programme, and detected no difference in nutritional
outcomes between the two groups. Another trial compared growth monitoring with
and without a standard chart, measuring maternal knowledge of women about
nutrition. It showed small numerical differences in test scores. DISCUSSION AND
IMPLICATIONS: Current policies appear to be based on the opinion that investment
in the activity has worthwhile health benefits, and does no harm. No reliable
evidence was found to support or refute this.
PMID- 10685920
TI - Parental recall of birth weight: how accurate is it?
AB - OBJECTIVE: To assess the accuracy of parental recall of birth weight in a British
population and to investigate whether social class and age of the child
significantly influence the accuracy of recalled birth weight. METHODS: A
questionnaire was given to parents whose children were participating in a blood
pressure study and the hospital records were retrieved to check the birth weight
data. RESULTS: At the time of the study, the children (n = 649) ranged in age
from 6 to 15 years. Seventy five per cent of the recalled birth weights were
within 50 g of that recorded in the hospital records. No significant associations
were found between the difference in birth weights (recalled birth weight minus
hospital record) and social class of the parents or age of the child at time of
data collection. CONCLUSION: This large study shows that parental recall of birth
weight is good across the social classes and up to 16 years after delivery. There
was no evidence of systematic bias, which would prejudice results of studies on
the relation of birth weight to adult hypertension.
PMID- 10685921
TI - Height and weight reference curves for homozygous sickle cell disease.
AB - OBJECTIVE: To derive height and weight growth reference curves for children with
homozygous sickle cell disease. STUDY DESIGN: Subjects (n = 315) were
participants in a population based, longitudinal cohort study of sickle cell
disease in Kingston, Jamaica. Regular measurements of height and weight were made
from enrollment into the study at birth up to 22 years of age. RESULTS: Sex
specific growth reference curves for height for age and weight for age covering
the age range 0-18 years are presented. CONCLUSION: These growth reference curves
are suitable for identifying coincidental growth problems in children with
homozygous sickle cell disease.
PMID- 10685922
TI - Wechsler subscale IQ and subtest profile in early treated phenylketonuria.
AB - AIM: Mildly depressed IQ is common in treated phenylketonuria. This study
explored whether a particular intellectual ability profile typifies early and
continuously treated phenylketonuria and whether component skills comprising the
IQ relate to socioeconomic and treatment factors. METHODS: IQ scores were
collected retrospectively from variants of the "Wechsler intelligence scale for
children" performed at age 8 on 57 children with early treated, classic
phenylketonuria. The mental ability pattern underlying IQ was investigated by
analysing subscale and subtest scores and dietary factors, such as historical
phenylalanine blood concentrations. RESULTS: The children's mean full scale IQ of
91.11 was significantly below the healthy population norm. There was a
significant discrepancy between their mean verbal IQ (94.65) and mean performance
IQ (89.42), suggestive of a spatial deficit, but the data did not support a
biochemical or sociological explanation. Individual Wechsler subtests had no
distinctive pattern. Phenylalanine control at age 2 was predictive of overall IQ.
At this age, children with annual median phenylalanine < 360 micromol/litre
(recommended UK upper limit) had a mean IQ 10 points higher than those above.
CONCLUSIONS: Early and continuous treatment of phenylketonuria does not
necessarily lead to normalisation of overall IQ. Verbal intelligence in the
primary school years appears to normalise if blood phenylalanine is maintained
below 360 micromol/litre in infancy, but spatial intelligence may remain poor.
However, the discrepancy in skill development is not the result of social status
or treatment variables. Perhaps weak spatial intelligence is an ancillary effect
of a protective rearing style occasioned by the dietary treatment regimen.
PMID- 10685923
TI - The limping child.
PMID- 10685924
TI - Effect of genotype on changes in intelligence quotient after dietary relaxation
in phenylketonuria and hyperphenylalaninaemia.
AB - BACKGROUND: Associations between genotype and intellectual outcome in patients
with phenylketonuria are complicated because intelligence is influenced by many
variables, including environmental factors and other genetic determinants.
Intellectual changes with age, both on and after relaxation of diet, vary within
the patient population. This study aims to determine whether a significant
association exists between genotype and change in intelligence after relaxation
of diet. METHODS: 125 patients with hyperphenylalaninaemia and phenylketonuria
whose diet was relaxed after 8 years of age. Verbal, performance, and full scale
intelligence quotients at 8, 14, and 18 years were expressed as standard
deviation scores (IQ-SDS), and genotype as predicted residual enzyme activity
(PRA) of phenylalanine hydroxylase. RESULTS: IQ-SDS at 8, 14, and 18 years were
significantly below normal; no association was found between PRA and IQ-SDS.
Significant reductions in verbal and full scale IQ-SDS occurred between 8 and 14
years and 8 and 18 years. There was a significant association between PRA and the
reduction in verbal, performance, and full scale IQ between these years. Multiple
regression analysis of 18 year results, using 8 year results as covariates,
supported the association between PRA and IQ-SDS; after adjustment for
phenylalanine control, both up to and after the age of 8 years, the full scale IQ
SDS at 14 and 18 years was 0.15 higher for each 10% increase in PRA. CONCLUSIONS:
Genotype might be useful in predicting the likelihood of intellectual change in
patients with hyperphenylalaninaemia and phenylketonuria whose diet is relaxed
after the age of 8 years.
PMID- 10685925
TI - Behavioural phenotypes: what do they teach us?
PMID- 10685926
TI - Diagnosing idiopathic/cryptogenic epilepsy syndromes in infancy.
AB - PURPOSE: To determine the characteristics that permit diagnosis of the type of
epilepsy beginning in the 1st year of life, and to determine from what age such
characteristics are recognisable. PATIENTS: From 430 non-selected patients who
began having seizures in the 1st year of life and were referred to the
neuropaediatric department of Saint Vincent de Paul Hospital, those with
epileptic spasms as the first seizure type, those with recognisable aetiology,
and those for whom early history was not reliable were excluded. METHODS: For the
remaining 140 patients, the age at which clinical and electroencephalogram (EEG)
characteristics met those of recognisable epilepsy syndromes according to the
ILAE classification was studied. RESULTS: In most epilepsy syndromes, the
diagnosis could be made within three months of onset of the disorder. The most
difficult was to distinguish cryptogenic localisation related epilepsy from
severe myoclonic epilepsy in infancy. Repeat focal seizures and persisting spike
focus were the earliest and most reliable signs of localisation related epilepsy,
whereas alternating focal seizures, generalised myoclonus, and/or spike waves
appeared before the end of the 1st year in most infants with severe myoclonic
epilepsy. However, for 39 patients it was not possible to reach the diagnosis of
a precise syndrome. CONCLUSION: For over three quarters of infants with
cryptogenic/idiopathic epilepsy, it is possible to reach a syndromic diagnosis
within the first months of the disease, based on clinical and EEG
characteristics. However, for one quarter, no diagnosis is possible based on the
currently available classification.
PMID- 10685927
TI - Morbidity in reflex sympathetic dystrophy.
AB - Reflex sympathetic dystrophy (RSD), an unusual diagnosis in general paediatrics,
is well recognised by paediatric rheumatologists. This study reports the
presentation and the clinical course of 46 patients (35 female, age range 8-15.2)
with RSD. The patients saw professionals from an average of 2.3 specialties
(range 1-5). Twenty five (54%) had a history of trauma. Median time to diagnosis
was 12 weeks (range 1-130). Many children had multiple investigations and
treatments. Once diagnosis was made, treatment followed with physiotherapy and
analgesics. Median time to recovery was seven weeks (range 1-140), with 27.5%
relapsing. Nine children required assessment by the child and adolescent
psychiatry team. This disease, though rare, has significant morbidity and it is
therefore important to raise clinicians' awareness of RSD in childhood. Children
with the condition may then be recognised and referred for appropriate management
earlier, and spared unnecessary investigations and treatments which may
exacerbate the condition.
PMID- 10685928
TI - Proteus syndrome and immunodeficiency.
AB - A 10 year old boy with Proteus syndrome presented with a pericardial effusion of
unknown aetiology. Immunological investigation revealed low serum IgG and IgA,
accompanied by low levels of specific antibodies to pneumococcal and haemophilus
type B polysaccharides. Circulating lymphocyte surface marker profile revealed T
and B cell lymphopenia. This is the first report of hypogammaglobulinaemia
occurring in the Proteus syndrome.
PMID- 10685929
TI - Fits, pyridoxine, and hyperprolinaemia type II.
AB - The rare inherited disorder hyperprolinaemia type II presents with fits in
childhood, usually precipitated by infection. A diagnosis of hyperprolinaemia
type II and vitamin B(6) deficiency was made in a well nourished child with fits.
It is thought that pyridoxine deficiency was implicated in her fits and was the
result of inactivation of the vitamin by the proline metabolite, pyrroline-5
carboxylate.
PMID- 10685930
TI - Physical treatment of fever.
AB - Fever is a common symptom of childhood illness, and much time and effort is spent
in the pursuit of reducing high temperature. Although antipyretic drugs are the
main form of treatment, this report considers the part that physical treatments
might play in reducing the temperature of febrile children. Such treatments
include tepid sponging, removing clothing, and cooling the environment. Of these
treatments, tepid sponging has been studied most extensively, as an addition to
paracetamol, but seems to offer little advantage over paracetamol alone. It is
likely that other methods might be equally ineffective because they all rely on
similar methods of heat loss.
PMID- 10685931
TI - Laparoscopic surgery in children.
PMID- 10685932
TI - Concentrations of antimony in infants dying from SIDS and infants dying from
other causes.
AB - OBJECTIVES: Raised concentrations of antimony have been found in infants dying of
sudden infant death syndrome (SIDS). The presumed source of this antimony is
toxic gases generated from fire retardants that are present in cot mattresses.
The aim of this study was to determine the role of antimony in SIDS. DESIGN:
Samples of liver, brain, serum, and urine were collected from all patients dying
from SIDS and a group of aged matched control infants who had died of other
causes. SETTING: Nationwide study in Ireland. SUBJECTS: 52 infants dying from
SIDS and 19 control infants aged > 7 days and < 1 year. RESULTS: The median
concentration of antimony in the liver and brain of infants dying of SIDS was < 1
ng/g, with no difference detected between the infants dying from SIDS and the
control infants. The range of antimony in the serum of infants dying of SIDS was
0.09-0.71 microg/litre (median, 0.26). Although no difference was found between
infants dying from SIDS and control infants, SIDS infants were found to have
higher concentrations when compared with healthy infants in the 1st year of life,
probably as a result of release of antimony into serum after death. Urine
antimony concentrations in infants dying from SIDS were < 3.91 ng/mg (corrected
for creatinine) and similar to values found both in control infants and healthy
infants. CONCLUSION: There is no evidence to support a causal role for antimony
in SIDS.
PMID- 10685933
TI - Infant feeding and adult glucose tolerance, lipid profile, blood pressure, and
obesity.
AB - BACKGROUND: It is generally accepted that breast feeding has a beneficial effect
on the health of infants and young children. Recently, a few studies have shown
that the method of infant feeding is also associated with cardiovascular disease
and its risk factors in adult life. AIMS: To examine the association between the
method of infant feeding in the first weeks after birth and glucose tolerance,
plasma lipid profile, blood pressure, and body mass in adults aged 48-53 years.
METHODS: Subjects born at term between 1 November 1943 and 28 February 1947 in
the Wilhelmina Gasthuis in Amsterdam around the time of a severe period of famine
(late November 1944 to early May 1945). For 625 subjects, information was
available about infant feeding at the time of discharge from hospital (on average
10.4 days after birth), and at least one blood sample after an overnight fast.
RESULTS: Subjects who were bottle fed had a higher mean 120 minute plasma glucose
concentration after a standard oral glucose tolerance test than those who were
exclusively breast fed. They also had a higher plasma low density lipoprotein
(LDL) cholesterol concentration, a lower high density lipoprotein (HDL)
cholesterol concentration, and a higher LDL/HDL ratio. Systolic blood pressure
and body mass index were not affected by the method of infant feeding.
CONCLUSIONS: Exclusive breast feeding seems to have a protective effect against
some risk factors for cardiovascular disease in later life.
PMID- 10685934
TI - Effect of prone sleeping on circulatory control in infants.
AB - BACKGROUND: The mechanism of death in sudden infant death syndrome (SIDS) remains
unclear. Progressive bradycardia is the pre-eminent terminal event, suggesting
that circulatory failure might be a crucial factor. Vasomotor tone regulates the
circulatory system by controlling blood volume distribution while maintaining
venous return and blood pressure. AIM: To examine whether prone sleeping, the
most consistently identified risk factor for SIDS, has a measurable influence on
vasomotor/circulatory control. METHODS: 44 full term infants (mean age, 7.9
weeks) were studied during an overnight sleep. Recordings were made while the
infants were horizontal and asleep in the supine and prone positions, and
repeated after a head up tilt to 60 degrees, maintained for 30 minutes, while in
both sleep positions. Blood pressure, heart rate, anterior shin, and anterior
abdominal wall skin temperatures were measured. RESULTS: Systolic blood pressure
was lower, but peripheral skin temperature and heart rate were higher during
sleep, while horizontal, in the prone rather than the supine position. After
tilting, there was a greater reduction in blood pressure and a greater increase
in peripheral skin temperature and heart rate when in the prone position.
Anterior abdominal wall skin temperature did not vary in either sleeping
positions while horizontal or tilted. CONCLUSION: Prone sleeping has a measurable
effect on circulatory control, with a reduction in vasomotor tone resulting in
peripheral vasodilatation, a higher peripheral skin temperature, a lower blood
pressure, and a higher resting heart rate. Because vasomotor tone is crucially
important in circulatory control this could be a factor in increasing the risk of
SIDS.
PMID- 10685935
TI - Temporal bone computed tomography findings in bilateral sensorineural hearing
loss.
AB - AIM: To examine the yield of computed tomography (CT) of the temporal bones when
investigating sensorineural hearing loss (SNHL) and to identify factors
associated with CT findings. METHODS: Retrospective analysis of 116 consecutively
investigated children with bilateral SNHL at the audiology department of Great
Ormond Street Hospital, London. Main outcome measures were CT results, hearing
loss parameters, history, and clinical examination. RESULTS: A total of 33
(28.4%) CT scans were identified as abnormal. Children with profound and/or
progressive hearing loss and/or craniofacial abnormalities were more likely to
have an abnormal CT scan and together accounted for 25 abnormal CT scans. Sex,
consanguineous parents, or family history of SNHL were not associated with CT
findings. Dilated vestibular aqueduct was significantly correlated with the
presence of progressive SNHL. CONCLUSIONS: All children with SNHL should undergo
radiological investigation of the petrous bones/inner ear; abnormalities are more
likely to be found in cases with craniofacial abnormalities, or profound or
progressive hearing loss. The decision whether to perform a CT or magnetic
resonance imaging will depend on scanner availability, expertise, and management
considerations, but cochlear implant candidates will require both.
PMID- 10685936
TI - Measurement and interpretation of blood pressure.
PMID- 10685937
TI - FETAL AND NEONATAL EDITION march 2000 issue
PMID- 10685979
TI - Genetics of neonatal hyperinsulinism.
AB - Congenital hyperinsulinism (HI) is a clinically and genetically heterogeneous
entity. The clinical heterogeneity is manifested by severity ranging from
extremely severe, life threatening disease to very mild clinical symptoms, which
may even be difficult to identify. Furthermore, clinical responsiveness to
medical and surgical management is extremely variable. Recent discoveries have
begun to clarify the molecular aetiology of this disease and thus the mechanisms
responsible for this clinical heterogeneity are becoming more clear. Mutations in
4 different genes have been identified in patients with this clinical syndrome.
Most cases are caused by mutations in either of the 2 subunits of the beta cell
ATP sensitive K(+) channel (K(ATP)), whereas others are caused by mutations in
the beta cell enzymes glucokinase and glutamate dehydrogenase. However, for as
many as 50% of the cases, no genetic aetiology has yet been determined. The study
of the genetics of this disease has provided important new information about beta
cell physiology. Although the clinical ramifications of these findings are still
limited, in some situations genetic studies might greatly aid in patient
management.
PMID- 10685980
TI - Hyperinsulinism of infancy: towards an understanding of unregulated insulin
release. European Network for Research into Hyperinsulinism in Infancy.
AB - Insulin is synthesised, stored, and secreted from pancreatic beta cells. These
are located within the islets of Langerhans, which are distributed throughout the
pancreas. Less than 2% of the total pancreas is devoted to an endocrine function.
When the mechanisms that control insulin release are compromised, potentially
lethal diseases such as diabetes and neonatal hypoglycaemia are manifest. This
article reviews the physiology of insulin release and illustrates how defects in
these processes will result in the pathophysiology of hyperinsulinism of infancy.
PMID- 10685981
TI - Practical management of hyperinsulinism in infancy.
AB - Hyperinsulinism in infancy is one of the most difficult problems to manage in
contemporary paediatric endocrinology. Although the diagnosis can usually be
achieved without difficulty, it presents the paediatrician with formidable day to
day management problems. Despite recent advances in understanding the
pathophysiology of hyperinsulinism, the neurological outcome remains poor, and
there is often a choice of unsatisfactory treatments, with life long sequelae for
the child and his or her family. This paper presents a state of the art overview
on management derived from a consensus workshop held by the European network for
research into hyperinsulinism (ENRHI). The consensus is presented as an
educational aid for paediatricians and children's nurses. It offers a practical
guide to management based on the most up to date knowledge. It presents a
proposed management cascade and focuses on the clinical recognition of the
disease, the immediate steps that should be taken to stabilise the infant during
diagnostic investigations, and the principles of definitive treatment.
PMID- 10685982
TI - Persistent hyperinsulinaemic hypoglycaemia of infancy: a heterogeneous syndrome
unrelated to nesidioblastosis.
PMID- 10685983
TI - Maternal insulin-like growth factor binding protein-1, body mass index, and fetal
growth.
AB - AIM: To examine the hypothesis that the maternal insulin-like growth factor
system may constrain fetal growth. METHODS: A prospective observational study of
maternal serum insulin-like growth factor binding protein-1 (IGFBP-1) and fetal
growth was undertaken in neonates with birthweights below the 5th centile. They
had been classified either as having fetal growth restriction (FGR) due to
placental dysfunction (increased umbilical artery Doppler pulsatility index (PI);
n = 25) or as being small for gestational age (SGA; normal umbilical artery PI,
growth velocity and amniotic fluid; n = 27). Eighty nine controls had normal
birthweights (5th-95th centile), umbilical artery PI, growth velocity, and
amniotic fluid. IGFBP-1 was measured by radioimmunoassay. RESULTS: Among the
controls, there was no significant correlation between IGFBP-1 and birthweight
after allowing for body mass index (BMI). Maternal BMI was high in FGR and after
adjusting for this, IGFBP-1 was increased (109 ng/ml) compared with SGA babies
(69 ng/ml) and controls (57 ng/ml) and correlated with the umbilical artery PI.
CONCLUSIONS: Maternal IGFBP-1 is probably not part of normal placental function.
Its increase in FGR could be the cause or consequence of impaired placental
perfusion, but high IGFBP-1 concentrations might further reduce the availability
of maternal IGF-I to the placenta. This could worsen placental function and so
adversely affect fetal growth.
PMID- 10685984
TI - Risk adjusted and population based studies of the outcome for high risk infants
in Scotland and Australia. International Neonatal Network, Scottish Neonatal
Consultants, Nurses Collaborative Study Group.
AB - OBJECTIVES: To compare outcomes of care in selected neonatal intensive care units
(NICUs) for very low birthweight (VLBW) or preterm infants in Scotland and
Australia (study 1) and perinatal care for all VLBW infants in both countries
(study 2). DESIGN: Study 1: risk adjusted cohort study; study 2: population based
cohort study. SUBJECTS: Study 1: all 2621 infants of < 1500 g birth weight or <
31 weeks' gestation admitted to a volunteer sample of hospitals comprising eight
of all 17 Scottish NICUs and six of all 12 tertiary NICUs in New South Wales and
Queensland in 1993-1994; study 2: all 5986 infants of 500-1499 g birth weight
registered as live born in Scotland and Australia in 1993-1994. MAIN OUTCOMES:
Study 1: (a) hospital death; (b) death or cerebral damage, each adjusted for
gestation and CRIB (clinical risk index for babies); study 2: neonatal (28 day)
mortality. RESULTS: Study 1. Data were obtained for 1628 admissions in six
Australian NICUs, 775 in five Scottish tertiary NICUs, and 148 in three Scottish
non-tertiary NICUs. Crude hospital death rates were 13%, 22%, and 22%
respectively. Risk adjusted hospital mortality was about 50% higher in Scottish
than in Australian NICUs (adjusted mortality ratio 1.46, 95% confidence interval
(CI) 1.29 to 1.63, p < 0.001). There was no difference in risk adjusted outcomes
between Scottish tertiary and non-tertiary NICUs. After risk adjustment, death or
cerebral damage was more common in Scottish than Australian NICUs (odds ratio
1.9, 95% CI 1.5 to 2.5). Both these risk adjusted adverse outcomes remained more
common in Scottish than Australian NICUs after excluding all infants < 28 weeks'
gestation from the comparison. Study 2. Population based neonatal mortality in
infants of 500-1499 g was higher in Scotland (20.3%) than Australia (16.6%)
(relative risk 1.22, 95% CI 1.08 to 1. 39, p = 0.002). In a post hoc analysis,
neonatal mortality was also higher in England and Wales than in Australia.
CONCLUSIONS: Study 1: outcome was better in the Australian NICUs. Study 2:
perinatal outcome was better in Australia. Both results may be consistent, at
least in part, with differences in the organisation and implementation of
neonatal care.
PMID- 10685985
TI - Reproductive decisions after neonatal screening identifies cystic fibrosis.
AB - AIMS: To document the reproductive choices made by women in New South Wales,
Australia, after neonatal screening has identified cystic fibrosis (CF). METHODS:
A sample of women attending cystic fibrosis clinics in New South Wales who had a
child (or children) diagnosed by neonatal screening between 1981 and 1996 were
interviewed. RESULTS: Two thirds of the women chose to avoid having another child
with CF. The uptake of prenatal diagnosis was 66% in women who had a subsequent
pregnancy; of these 69% terminated or would have terminated an affected fetus.
Fifty nine per cent of the women who decided against a further pregnancy made
this decision in order to avoid having another child with CF. CONCLUSIONS: These
data show that having a child with CF influenced subsequent reproductive choices.
In addition to the medical advantages of an early diagnosis offered by neonatal
screening, this also allows informed future reproductive decisions.
PMID- 10685986
TI - Cranial ultrasound abnormalities in full term infants in a postnatal ward:
outcome at 12 and 18 months.
AB - OBJECTIVE: To investigate whether cranial ultrasound abnormalities found in low
risk full term infants had any influence on neurodevelopmental outcome. METHODS:
For 103 infants who had a neurological assessment, a cranial ultrasound
examination, and for whom antenatal and perinatal data were collected within 48
hours of delivery, neurodevelopmental status was evaluated at 12 and 18 months.
The results of a scored neurological examination and the Griffiths mental
developmental scale were correlated with the presence and type of ultrasound
abnormality found in the neonatal period. RESULTS: None of the infants with
ultrasound abnormalities showed any signs of cerebral palsy or severe
developmental delay. There was also no significant difference between the overall
neurological and neurodevelopmental scores of the infants with normal and
abnormal ultrasound findings. However, when the individual subscales of the
Griffiths test were analysed, all infants with bulky choroid or intraventricular
haemorrhage had normal scores in all subscales, four of eight with
periventricular white matter lesions had low scores on the locomotor subscale,
and three of five with asymmetrical ventricles had low scores on the performance
subscale. The presence of adverse antenatal and perinatal factors did not affect
the outcome in this group. CONCLUSION: Incidental ultrasound abnormality in full
term neonates, in particular intraventricular haemorrhage, although common,
appear to have a good prognosis. Longer follow up studies are needed to see
whether some of these infants, in particular those with white matter lesions,
develop dyspraxia or other minor neurological impairments at school age.
PMID- 10685987
TI - Correlation between visual function, neurodevelopmental outcome, and magnetic
resonance imaging findings in infants with periventricular leucomalacia.
AB - AIM: To evaluate the correlation between visual function and neurodevelopmental
outcome in children with periventricular leucomalacia at 1 and 3 years. METHOD:
Visual acuity, visual field, ocular motility, and optokinetic nystagmus were
tested in 29 infants with periventricular leucomalacia by brain magnetic
resonance imaging. All infants also had a structured neurological examination and
a Griffiths developmental assessment. RESULTS: 21 of the infants showed at least
one abnormality of visual function. The degree of visual impairment-that is, the
number of visual tests showing abnormal results-correlated well with the results
on developmental assessment at both ages. CONCLUSION: Multivariate analysis
showed that visual impairment was the most important variable in determining the
neurodevelopmental scores of these infants, more than their motor disability and
the extent of their lesions on magnetic resonance imaging.
PMID- 10685988
TI - Sensorineural hearing loss and prematurity.
AB - OBJECTIVE: To elucidate clinical antecedents of sensorineural hearing loss (SNHL)
in very preterm infants. DESIGN: Case-control study. SUBJECTS: Fifteen children <
33 weeks' gestation with significant SNHL born between 1 January 1990 and 31
December 1994, detected within 9 months of birth, and 30 matched control
children. METHODOLOGY: Perinatal variables in the two groups were compared using
non-parametric tests and conditional logistic regression (EGRET). RESULTS: Median
birth weight for the index group was 960 g (range 600-2914 g) compared with 1026
g (range 410-2814 g) for controls. Children with SNHL had longer periods of
intubation, ventilation, oxygen treatment, and acidosis, and more frequent
treatment with dopamine or frusemide. Neither peak nor trough aminoglycoside
levels, nor duration of jaundice or level of bilirubin varied between groups.
However, SNHL was more likely if peak bilirubin levels coexisted with netilmicin
use (odds ratio (95% confidence interval) 14.2 (1.8 to 113.6)) or if acidosis
occurred when bilirubin levels were over 200 micromol/l (OR 8.0 (0.9 to 71.6).
Frusemide use in the face of high serum creatinine levels (OR 8.9 (1.1 to 74.5))
or netilmicin treatment (OR 5.0 (0.99 to 24.8)) was also associated with SNHL. At
12 months of age, seven of 15 children with SNHL had evidence of cerebral palsy
compared with two of 30 controls (OR 12.3 (2.1 to 71)). CONCLUSIONS: Preterm
children with SNHL required more intensive care in the perinatal period and
developed more neurological complications than controls. Among very preterm
babies, the coexistence of risk factors for hearing loss may be more important
than the individual factors themselves.
PMID- 10685989
TI - Severe retinopathy of prematurity and its association with different rates of
survival in infants of less than 1251 g birth weight.
AB - BACKGROUND: There is controversy over whether improved survival of preterm
infants has resulted in a higher incidence of severe (grade 3 or greater)
retinopathy of prematurity (ROP). AIM: To compare survival rates and rates of >
or = stage 3 ROP-that is, with a high risk of sequelae-in preterm infants in five
English cities where, anecdotally, the incidence of ROP is reported to show
considerable variation. METHODS: All infants of birth weight < 1500 g and or
gestational age < 32 weeks, born in 1994 in one of the cities or transferred in
within 48 hours, were studied. The populations were adjusted for case mix
variation using CRIB (clinical risk index for babies, a disease severity scoring
system). The incidence of severe ROP, the actual death rate, and that adjusted
for disease severity were determined. RESULTS: The rate of severe ROP per 1000
births was higher in city 1 than in all the other cities. This increase in
comparison with city 2 and city 4 was significant (city 1, 167 (95% confidence
interval (CI) 96 to 260); city 2, 24 (6 to 59); city 4, 16 (1 to 84)). A
significant difference was not seen between city 1 and cities 3 (23 (1 to 120))
and 5 (74 (21 to 79)). The relative risk of developing severe ROP in city 1
compared with all the other cities was 5.5 (2.5 to 11.9). The actual death rate
per 1000 births in city 1 was significantly lower than that predicted by
modelling death against CRIB score (city 1: actual 270; predicted 385 (95% CI 339
to 431)). In contrast, the other cities had actual death rates as predicted, or
worse than predicted, by CRIB. INTERPRETATION: A significantly higher incidence
of severe ROP was identified in one of the five cities studied. Variation in
survival rates among high risk infants may explain this observation.
PMID- 10685990
TI - Haematocrit and red blood cell transport in preterm infants: an observational
study.
AB - AIMS: To test whether cardiac output acts as a compensatory response to changes
in haematocrit. METHODS: A cohort of 38 preterm infants (27-31 weeks' gestation)
was studied with repeated Doppler measurements of left ventricular output during
the 1st month of life. Red blood cell transport was calculated when the duct was
closed. RESULTS: Multiple regression analysis showed that left ventricular output
correlated negatively with haematocrit when the duct was closed (n = 84) and when
it was open (n = 59). The influence of an increase of 10% in haematocrit absolute
value on mean (SD) left ventricular output was estimated at -55 (11) ml/kg/min.
Mean (SD) red blood cell transport was 132 (30) ml/kg/min with a mean (SD) intra
individual variability of 20% (8.8%). Red blood cell transport was increased more
frequently by left ventricular output than by haematocrit. Haematocrit and left
ventricular output but not red blood cell transport were dependent on postnatal
age. CONCLUSION: These results suggest that in preterm infants cardiac output
adaptation is effective in attenuating the effects of red blood cell mass
variations on systemic oxygen carrying capacity.
PMID- 10685991
TI - Measurement of interleukin 10 in bronchoalveolar lavage from preterm ventilated
infants.
AB - BACKGROUND: Interleukin 10 (IL-10) is a cytokine that downregulates inflammation,
in part by reducing the production of the proinflammatory cytokines IL-1beta and
IL-8. It has been suggested that an inability to produce IL-10 might predispose
preterm infants to develop chronic lung disease. AIM: To measure IL-10, IL-1beta,
and IL-8 in bronchoalveolar lavage fluid from ventilated preterm infants in a
prospective cohort study. PATIENTS: 17 consecutive newborn infants < or = 29
weeks' gestational age (median, 25; 9 boys) who were ventilated from birth
underwent daily bronchoalveolar lavage sampling. RESULTS: 102 samples were
collected, of which 57 contained IL-10 in amounts that were comparable with those
found previously in ventilated term infants with respiratory failure. Chronic
lung disease developed in 9 of the 11 survivors and all 9 infants had produced IL
10. IL-1beta and IL-8 were detected in nearly all samples and were raised
throughout the course of sample collection. CONCLUSION: IL-10 is readily
detectable in early bronchoalveolar lavage samples from ventilated preterm
infants, although it remains unclear whether this cytokine has any influence on
the development of chronic lung disease.
PMID- 10685992
TI - A randomised control study of partial liquid ventilation after airway lavage with
exogenous surfactant in a meconium aspiration syndrome animal model.
AB - AIMS: To test the hypothesis that lavage with exogenous surfactant before partial
liquid ventilation in meconium aspiration syndrome (MAS) would improve debris
removal, and therefore the effectiveness of partial liquid ventilation. METHODS:
12 newborn piglets were randomised into 4 groups, partial liquid ventilation or
gas ventilation, with and without surfactant lavage. Physiological and blood gas
data were compared between groups by analysis of variance. RESULTS: Arterial
oxygen pressure (PaO(2)) was improved in the group treated with surfactant lavage
when compared with the group not receiving surfactant. PaO(2) in the group
receiving surfactant lavage followed by partial liquid ventilation was further
improved when compared with the group treated with surfactant lavage followed by
gas ventilation and the group receiving partial liquid ventilation alone.
CONCLUSION: The effectiveness of partial liquid ventilation in MAS might be
enhanced by pretreatment with exogenous surfactant bronchial lavage.
PMID- 10685993
TI - Type 2 Gaucher disease: the collodion baby phenotype revisited.
AB - The association of Gaucher disease, the inherited deficiency of lysosomal
glucocerebrosidase (EC 3.2.1.45), and congenital ichthyosis was first noted a
decade ago. Subsequently, a null allele type 2 Gaucher mouse was generated that
also exhibited ichthyotic skin, confirming that the skin disorder and enzyme
deficiency were directly related. This paper details the clinical and molecular
characterisation of 6 cases of type 2 Gaucher disease presenting with the
collodion baby phenotype. The identified mutant glucocerebrosidase alleles
include two novel mutations (S196P and R131L) and two rare point mutations (R120W
and R257Q), as well as alleles resulting from recombination with the nearby
glucocerebrosidase pseudogene. There is significant genotypic heterogeneity in
this rare subset of patients with type 2 Gaucher disease. Gaucher disease should
be considered in the differential diagnosis of congenital ichthyosis in the
newborn period.
PMID- 10685994
TI - Proximity to maternity services and stillbirth risk.
AB - A study of all 77 995 live births and 1234 stillbirths to mothers living in West
Cumbria from 1950 to 1989 found no significant increase in stillbirth risk with
distance of mother's residence from the first or second nearest maternity
services, after allowing for year of birth, father's social class, and birth
order.
PMID- 10685995
TI - Dr Edward Rigby of Norwich (1747-1821) and antepartum haemorrhage.
PMID- 10685996
TI - Apoptosis in transfusion medicine: of death and dying--is that all there is?
PMID- 10685997
TI - Blocking T-cell costimulation in transplantation: opportunities and challenges.
PMID- 10685998
TI - Committee report. Nucleic acid amplification testing of blood donors for
transfusion-transmitted infectious diseases: Report of the Interorganizational
Task Force on Nucleic Acid Amplification Testing of Blood Donors.
PMID- 10685999
TI - White cell apoptosis in platelet concentrates.
AB - BACKGROUND: The aim of the present study was the evaluation of the apoptosis in
residual white cells (WBCs) contained in platelet concentrates (PCs) and of the
relationship of this apoptosis with the concentration of inflammatory cytokines
in the medium and with platelet activation. STUDY DESIGN AND METHODS: Three
independent methods were used to evaluated apoptosis in WBCs present in 9 PCs,
either from single donors by apheresis (SD-PCs) or from pooled buffy coats (BC
PCs). All PCs were divided in two parts, one of which was irradiated. PCs were
stored up to 4 days at room temperature, and samples were withdrawn daily for
analysis of apoptosis, of platelet activation (surface and soluble CD62P), and of
cytokine concentration (interleukin [IL]-1alpha, IL-1beta, IL-6, IL-8, and tumor
necrosis factor alpha). RESULTS: Apoptosis was found to occur with storage in
both irradiated and nonirradiated units. Platelet activation increased with
storage time and was higher in BC-PCs. The amount of released cytokines was
rather variable among PC units. Only IL-8 was consistently found to increase with
storage time. CONCLUSIONS: Apoptosis of residual WBCs occurred in PC units as a
function of storage time. The amount and the time course of apoptosis seem to
correlate with IL-8 release rather than with platelet activation or with the
occurrence of febrile nonhemolytic transfusion reactions.
PMID- 10686000
TI - Nuclear matrix protein is released from apoptotic white cells during cold (1-6
degrees C) storage of concentrated red cell units and might induce antibody
response in multiply transfused patients.
AB - BACKGROUND: A previous study showed that white cells in blood units undergo
apoptosis during storage. STUDY DESIGN AND METHODS: The present study attempts to
show the release of nuclear matrix protein (NMP) in the supernatants of red cell
units and to determine whether antibodies against nuclear components may be
present in multiply transfused patients; the methods employed were enzyme-linked
immunosorbent assay, flow cytometry, microscopy, immunoblotting,
immunofluorescence, and confocal laser-scanning microscopy. RESULTS: NMP is
released from white cells in the supernatant of packed red cell units upon cold
storage (1-6 degrees C). The concentration of NMP correlates well with the degree
of apoptosis, as analyzed by flow cytometry, nuclear dye staining, and DNA gel
electrophoresis. Immunofluorescence also shows that white cells undergoing
apoptosis (pre-G(1) peak, as seen by propidium iodide staining and flow
cytometry) have an NMP content lower than control cells, which confirms an actual
release of NMP. Moreover, immunoblotting analysis and immunofluorescent staining
showed that, in 4 of 38 multiply transfused patients, autoantibodies against NMPs
were present without any clinical or laboratory sign of autoimmune disease. One
of the sera, recognizing a 64-kDa NMP, immunostained nuclear dots that were
identified as coiled bodies because of their colocalization with p 80 coilin.
CONCLUSION: NMP is released in the supernatant of red cell units. The results
obtained from patients suggest that nuclear proteins released during apoptosis,
once transfused, may induce an immune response in multiply transfused patients.
PMID- 10686001
TI - High platelet contamination in progenitor cell concentrates results in
significantly lower CD34+ yield after immunoselection.
AB - BACKGROUND: Selection of CD34+ cells by specific immunoselection leads to a
significant loss of those cells. The factors influencing the yield and purity are
not well identified. The results of CD34+ selection from peripheral blood
progenitor cells (PBPCs) with high and low platelet contamination that are
harvested with two different cell separators are reported. STUDY DESIGN AND
METHODS: A progenitor cell concentrator (Ceprate SC, CellPro) was used to select
CD34+ cells from 41 PBPC concentrates from 23 consecutive patients with relapsed
non-Hodgkin's lymphoma (n = 3), breast cancer (n = 17), and multiple myeloma (n =
3). PBPC collection was performed by using two cell separators (CS3000 Plus,
Fenwal: Group A, n = 11; and Spectra, COBE: Group B, n = 9). To reduce platelet
contamination in the Spectra PBPC concentrates, an additional low-speed
centrifugation was performed before CD34+ cell selection (Group C, n = 3).
Leukapheresis components were stored overnight at 4 degrees C and combined with
the next day's collection before the CD34+ selection procedure in 19 patients.
RESULTS: A median of 1.5 leukapheresis procedures per patient were performed.
Pooled PBPC concentrates showed no statistical difference in median numbers of
white cells and CD34+ cells in Groups A and B: 3.2 (0.8-9.2) versus 4.4 (1.6-8.
3) x 10(10) white cells per kg and 15.0 (4.7-24.0) versus 12.0 (5. 6-34.0) x
10(6) CD34+ cells per kg. Platelet contamination was significantly higher in
Group B: 0.67 (0.15-2.4) versus 2.3 (0.5-7. 1) x 10(11) (p = 0.0273). After the
selection process, there was a significantly greater loss of CD34+ cells in Group
B than in Group A: 39.1 versus 63.2 percent (p = 0.0070), with a median purity of
78. 0 percent versus 81.0 percent. An additional low-speed centrifugation before
CD34+ cell selection seemed to reduce CD34+ cell loss in Group C with 16.9, 31.9,
and 37.5 percent, respectively. CONCLUSION: CD34+ cell selection from PBPC
concentrates resulted in an increased loss of CD34+ cells in concentrates with a
higher platelet content. To improve CD34+ yield, PBPC concentrates with an
initially low platelet contamination should be used, or additional low-speed
centrifugation should be performed.
PMID- 10686002
TI - Apheresis-induced platelet activation:comparison of three types of cell
separators.
AB - BACKGROUND: Platelet-harvesting technology differs in various cell separators.
Alteration in shear stress and biocompatibility of surfaces may give variable
platelet activation and thereby affect the quality of the component. STUDY DESIGN
AND METHODS: Four groups (n = 10) of single-needle apheresis procedures using
three cell separators, were compared: 1) Spectra LRS, 90-minute harvesting time;
2) MCS+, 90-minute harvest; 3) Amicus, 90-minute; and 4) Amicus, 45-minute. Whole
blood samples were collected from the donors as were samples from the final
components at intervals during the first 4 hours after cessation of the
apheresis. Platelet activation status and platelet activation capacity after
agonist stimulation were assessed by flow cytometry. RESULTS: No activated
platelets were found in preapheresis and postapheresis samples from the donors.
The platelets in the components from the Amicus (90-min) were significantly more
activated than those in the other groups of components: that is, there was
increased size of platelet aggregates, increased fraction of microparticles,
increased degranulation, increased fibrinogen receptor activation, and decreased
von Willebrand factor receptor expression. Moreover, the response of these
platelets to agonist stimulation was reduced for all activation variables.
CONCLUSIONS: After 90 minutes' processing time, platelets obtained with the
Amicus cell separator were significantly more activated than platelets harvested
with the Spectra and the MCS+.
PMID- 10686003
TI - Pressure cycling technology: a novel approach to virus inactivation in plasma.
AB - BACKGROUND: Hydrostatic-pressure virus inactivation is a novel approach to the
inactivation of pathogens in plasma and blood-derived components, that retains
the therapeutic properties of these products. STUDY DESIGN AND METHODS: A custom
built apparatus was used to pressurize human plasma samples spiked with lambda
phage. Phage titer and plasma protein activities were monitored after pressure
treatment. RESULTS: Pressure-mediated inactivation of lambda phage was found to
be an effective means for virus inactivation, particularly when performed at near
zero (0 degrees C) temperatures, rather than at temperatures above 20 degrees C
and below -40 degrees C. The efficiency of inactivation was improved by an
increase in applied pressure and repeated cycling from atmospheric to high
pressure. In contrast, activities of plasma proteins alkaline phosphatase and
total amylase did not vary with temperature and remained within 29 percent and 6
percent, respectively, of starting values after the same pressure treatments. By
combining cycling, near-zero temperatures, and high pressure, phage titers in
serum were reduced approximately 6 log after 10 to 20 minutes of treatment.
Activities of plasma proteins IgG, IgM, and factor X were at 104 percent, 89
percent, and 80 percent, respectively, of starting values after 20 minutes of the
same temperature and pressure treatment. CONCLUSION: High-pressure procedures may
be useful for the inactivation of viruses in blood and other protein-containing
components.
PMID- 10686004
TI - A fully automated blood typing system for hospital transfusion services. ABS2000
Study Group.
AB - BACKGROUND: The results of routine blood bank testing by a fully automated blood
typing system (ABS2000) were compared with those obtained by standard manual
methods in six hospital transfusion services. STUDY DESIGN AND METHODS: The
ABS2000 system uses microtiter plates for determining ABO and D types, solid
phase red cell adherence (SPRCA) assays for antibody detection, and modified
SPRCA plates for IgG crossmatches. The transfusion services used their standard
manual test tube methods. RESULTS: Of 3779 donors' samples tested for ABO types
(red cell typings only), 3.0 percent could not be interpreted by the ABS2000
system's neural network, because of clots, hemolysis, or lipemic samples. The
results for ABO types were concordant for 99.8 percent of the remaining samples.
Of 3779 donors' samples tested for D types, the results were concordant for 98.7
percent. Of 7580 patients' samples tested for ABO types (red cell and plasma
typings), 5.8 percent could not be interpreted by the ABS2000 system. There was
100-percent concordance of ABO typing results for the remaining 7140 samples.
There was 99. 7-percent concordance of results for patients' D types. The results
of 96.7 percent of antibody detection tests and 98.8 percent of crossmatches were
concordant. Neither method failed to detect a serologically incompatible
crossmatch that was associated with a specific, clinically significant
alloantibody. The ABS2000 system performed 45 confirmatory donor ABO and D types
in 115 minutes, 22 antibody detection tests in 116 minutes, 16 patients' ABO/D
types in 149 minutes, and 40 crossmatches in 140 minutes. CONCLUSION: The ABS2000
blood typing system automates routine blood bank tests with accuracy comparable
to that of hospital transfusion services' standard manual methods.
PMID- 10686005
TI - Molecular basis of Cromer blood group antigens.
AB - BACKGROUND: The Cromer blood group system consists of 10 antigens located on
decay-accelerating factor (DAF). Previous molecular genetic analysis has
determined the basis for four of these antigens. The present study was undertaken
to identify the mutations that determine the remaining antigens. STUDY DESIGN AND
METHOD: Existing or new data were used to localize each Cromer system antigen to
a specific short consensus repeat (SCR) domain of DAF. The exon encoding that SCR
domain was amplified by using the polymerase chain reaction (PCR) on genomic DNA
obtained from individuals of that Cromer phenotype, and the DNA product was
subjected to DNA sequence analysis. RESULTS: The Tc(a)/Tc(c) polymorphism is due
to an R18P amino acid substitution in SCR1 of DAF. The Es(a+)/Es(a-) polymorphism
is due to an I46N mutation in SCR1 of DAF. The WES(b)/WES(a) polymorphism is due
to an L48R mutation in SCR1 of DAF. The UMC+/UMC- polymorphism is due to a T216M
substitution in SCR4 of DAF. CONCLUSIONS: With information from previous reports
and the findings of this study, the molecular genetic basis of all known alleles
of the Cromer blood group system has been elucidated. Single amino acid
substitutions are responsible for 9 of the 10 antigens (all except the multiple
epitope antigen IFC).
PMID- 10686006
TI - Expression of Rh30 and Rh-related glycoproteins during erythroid differentiation
in a two-phase liquid culture system.
AB - BACKGROUND: To gain insight into the formation of the Rh complex during erythroid
differentiation, the ways in which Rh30 and Rh-related glycoproteins, especially
Rh50, were produced in a modified two-phase liquid culture system were studied.
STUDY DESIGN AND METHODS: A mononuclear cell fraction from fresh peripheral blood
was first cultured in a medium supplemented with conditioned medium collected
from the culture of a bladder carcinoma cell line (5637) for 7 days. Nonadherent
cells were then collected for culture in a secondary medium containing 2 U per mL
of erythropoietin to initiate erythroid differentiation. The expression of Rh30
and Rh50 during secondary culture (16 days) was monitored by flow cytometry.
RESULTS: D+ cells appeared after Day 4 and increased to 70 percent by Day 8. On
Day 12, 90 percent of the total cells became D+ and remained so until the end of
the culture. A similar expression profile was obtained for Rh50. As determined
from mean fluorescence intensities recorded in flow cytometry, the number of both
D and Rh50 antigenic sites per cell increased as the differentiation progressed.
Rh-related glycoprotein, CD47, had expression patterns significantly different
from those of Rh30 and Rh50. In addition, the cultured cells produced partially
glycosylated protein (approx. 32 kDa) in Rh50. CONCLUSION: Expressions of Rh30
and Rh50 occur simultaneously during erythroid differentiation, and both proteins
are most actively synthesized at the last stage of the differentiation. In
contrast, CD47 may be involved in expression of Rh30 in a different manner from
Rh50. The two-phase liquid culture system will be an excellent model for studying
the interaction among the components of the Rh complex during protein synthesis
and complex assembly on the cell membrane.
PMID- 10686007
TI - Neutrophil antigen 5b is carried by a protein, migrating from 70 to 95 kDa, and
may be involved in neonatal alloimmune neutropenia.
AB - BACKGROUND: Neutrophil antigen 5b has been described as involved in transfusion
reactions and not in neonatal alloimmune neutropenia. CASE REPORT: Anti-5b was
found in the serum of a mother of a persistently neutropenic newborn, who had
several bacterial infections. The neutropenia responded to treatment with
recombinant human granulocyte-colony-stimulating factor. Immunoprecipitation
experiments performed with this and three other 5b antisera identified a protein,
migrating from 70 to 95 kDa, as carrier of 5b. The observed pattern of migration
may point to heavy glycosylation of this protein. RESULTS: Six 5b-negative donors
were identified among 54 screened white donors, for a 5b gene frequency of 0.66.
CONCLUSION: Alloimmunization to 5b in pregnancy is rare. In the patients with
neonatal neutropenia analyzed in the last decade, this was the first case
discovered.
PMID- 10686008
TI - Comparison of flow cytometric assays with isotopic assays of (51)chromium-labeled
cells for estimation of red cell clearance or survival in vivo.
AB - BACKGROUND: A comparison was made between flow cytometric and conventional
radioisotopic assays in the determination of the clearance or survival of small
volumes of (51)chromium-labeled D+ red cells after injection into volunteers.
STUDY DESIGN AND METHODS: Four clearance studies were performed using 4 mL of
autologous D+ cells coated with anti-D at two concentrations (5 or 10 microg anti
D/mL red cells) transfused to two subjects at separate times. Five survival
studies were carried out using 5 mL of frozen-thawed D+ cells transfused to five
D- subjects with no detectable anti-D. Sequential blood samples were taken for
gamma counting and flow cytometry. Several methods were used to stain the
transfused red cells, and the data were analyzed by using three flow cytometers.
RESULTS: The determination of red cell clearance or survival by radioactivity
measurements gave results consistent with published data. However, none of the
flow cytometric assays exhibited the necessary sensitivity or accuracy in
quantitation of the rare events to provide reliable data for the calculation of
the initial clearance rate, the red cell half-life, or the mean cell lifespan,
although rough estimates of red cell clearance were obtained in some subjects.
This inability to accurately enumerate rare fluorescence-labeled cells was due
mainly to the presence of "background" events, which were a considerable problem
in some samples, when the coating level of anti-D was less than 3000 molecules of
IgG per cell. CONCLUSION: Flow cytometry may enable the crude estimation of the
percentage of small volumes (<5 mL) of transfused D+ red cells, but in this study
it was found that this method was not sufficiently accurate to determine the
initial clearance rate, red cell half-life, or mean cell lifespan. If the
proportion of transfused cells in the recipient is about 0.2 percent or less, the
use of radioisotopes for labeling cells for quantitative in vivo red cell
clearance or survival data should remain the method of choice.
PMID- 10686009
TI - DNA analysis in a paternity case involving a triploid fetus.
AB - BACKGROUND: A parentage testing laboratory was asked to perform testing in a case
of sexual assault that resulted in the conception of a child. Samples submitted
to the laboratory included blood from the mother, the alleged father, and the
fetus. CASE REPORT: DNA typing was used to determine if the suspect in this
sexual assault was the father of the expected child. DNA extracted from these
samples was subjected to both restriction fragment length polymorphism and
polymerase chain reaction/short-tandem repeat analysis at a total of 13 genetic
loci. Examination of DNA profiles for selected markers suggested that the fetus
was triploid. Triploidy was confirmed through the use of fluorescent in situ
hybridization of chromosomes, employing three chromosome-specific alpha satellite
probes and fetal trophoblast nuclei. Statistical interpretation of the test
results required identifying a method for calculation that would consider two
transmitted paternal genes. Attempts to modify the standard method of calculating
a paternity index were unsuccessful, because it was not possible to distinguish
between dispermy and diandry as the mechanism of conception. Therefore, the
likelihood ratio was calculated as the reciprocal of the random men not excluded
value or the proportion of the population that possesses all of the paternal
markers observed in the triploid fetus. CONCLUSION: Calculation of a likelihood
ratio employing the exclusionary power of a collection of DNA markers appears to
be the only method suitable for assigning weight to the significance of DNA
matches between an alleged father and a child who is triploid.
PMID- 10686010
TI - Prevalence of the newly described human circovirus, TTV, in United States blood
donors.
AB - BACKGROUND: A novel nonenveloped single-stranded circular DNA virus (TTV) was
recently identified. The prevalence of TTV in blood donors in the United States
is, however, still unclear. STUDY DESIGN AND METHODS: Viral DNA was detected in
US blood donors from five cities by using two sets of TTV primers:
NG059/NG061/NG063 primers, which amplified the conserved region of strains 1 and
2, and T801/T935 primers, which amplified the 5' end region of the TTV sequence.
A TTV antibody assay system was based on the detection of the truncated open
reading frame (ORF)-1 (amino acids 1-411) from type 1b. The truncated ORF-1 was
expressed as a fusion protein in Escherichia coli, and the fusion protein was
used as the antigen in the antibody assay system. RESULTS: Viremia was detected
in 21 (8. 4%) of 250 donors by use of NG059/NG061/NG063 primers and 104 (41. 6%)
of 250 by use of T801/T935 primers. There was little correlation among the
assays, which suggests the preferential detection of different strains with the
different primers. TTV antibody was detected in 38 of 100 donors: 32 (84%) of 38
with concurrent TTV viremia and 6 (16%) of 38 without TTV viremia. TTV viremia
and/or TTV antibody-positive samples were detected in 52 (52%) of 100 of US blood
donors. CONCLUSION: Evidence of infection or exposure to TTV appears to be common
among blood donors in United States.
PMID- 10686011
TI - Passive transfer of HIV-1 antibodies and absence of HIV infection after the
transfusion of HIV-1-seropositive red cells.
PMID- 10686012
TI - Blood component recalls in the United States, 1998.
PMID- 10686013
TI - Putting the cart before the horse.
PMID- 10686014
TI - Detection of Rh23 in the partial D phenotype associated with the D(Va) category.
PMID- 10686016
TI - Notice of duplicate publication
PMID- 10686015
TI - Do intravenous immunoglobulin products manufactured from plasma collected in
Italy place immunocompromised patients at risk of contracting human herpesvirus
8?
PMID- 10686017
TI - A large percentage of the Spanish population under 30 years of age is not
protected against hepatitis A.
AB - A seroepidemiological study was conducted to assess the seroprevalence of
hepatitis A (HAV) antibodies in the Spanish general population in 1992-93. A
total of 2744 subjects (1337 men and 1437 women) in the 5-59 years age range were
stratified by gender and age (5-12, 13-19, 20-29, 30-39, 40-49, 50-59 years). The
presence of total anti-HAV antibodies was investigated using a commercial enzyme
immunoassay. Fifty-five percent (95% CI: 53.5-57. 2%) of the subjects were
positive for anti-HAV antibodies, the age-standardized anti-HAV prevalence being
65.4%. Prevalence of seropositive subjects increased with increasing age (chi(2)
= 996, 17; P < 0.0001), being 11%, 25% and 54% for the 5-12, 13-19 and 20-29 age
groups respectively. The results from this study showed a remarkable decline in
seroprevalence rates among children, adolescents and young adults. The large
number of susceptible subjects in these groups of the population has public
health implications in a country with intermediate HAV prevalence.
PMID- 10686018
TI - The NS5a gene of hepatitis C virus in patients treated with interferon-alpha.
AB - Patients infected with hepatitis C virus (HCV) genotype 3 have a better response
to interferon-alpha (IFN-alpha) therapy than those infected with genotype 1.
There are extensive sequence differences between genotypes in the 3' half of the
NS5a gene. An association between IFN-alpha response and the interferon
sensitivity-determining region (ISDR) (amino acids 2209-2248) of HCV genotype 1b
has been described [Enomoto et al. (1996) New England Journal of Medicine 334:771
776]. A prospective study was conducted to determine whether the derived NS5A
amino acid sequence or quasi-species diversity could predict response to IFN
alpha therapy. Serum samples were obtained before, during, and after treatment
from 35 IFN-alpha-treated patients chronically infected with HCV (eight with
type1b,13 with type1a, and 14 with type3a). Nucleotide sequences were determined,
and amino acid sequences corresponding to residues 2178-2390 of the polyprotein
were derived. Quasi-species complexity was analysed by amplification of the ISDR
region (2270-2403), followed by single-stranded conformation polymorphism (SSCP).
No amino acid sequence that could be used to predict response to treatment was
found, and there was no selection of specific amino acid residues during
treatment. A striking lack of variability was seen in HCV genotype 3a, but the
small degree of variation could suggest an effect on response. SSCP showed that
variation in the predominant NS5a sequence occurred in the presence and absence
of therapeutically administered IFN-alpha. HCV quasi-species diversity
pretreatment did not predict IFN-alpha treatment outcome. The conclusion of the
study is that the amino acid sequence of NS5a cannot be used to predict the
efficacy of treatment with IFN-alpha in HCV-infected patients in Scotland. No
evidence was found to support the selection of IFN-alpha-resistant strains in the
NS5a gene.
PMID- 10686019
TI - Recombinant subunit ORF2.1 antigen and induction of antibody against
immunodominant epitopes in the hepatitis E virus capsid protein.
AB - A recombinant subunit antigen (ORF2.1), representing the carboxy-terminal 267
amino acids of the 660-amino-acid hepatitis E virus (HEV) capsid protein, was
expressed in Escherichia coli and used for the immunisation of rats. Purified
antigen formulated with either Aluminium Hydroxide Gel Adjuvant (Alum) or
Titermax gave high and equivalent levels of antibody after three doses. Responses
to two doses of 15, 75, or 150 microg antigen, formulated with Alum and given at
0 and 4 weeks, were also equivalent by 17 weeks after immunisation. Rats
initially developed antibody to a wide range of linear epitopes in the ORF2.1
region, but by 27 weeks the predominant response detected by Western
immunoblotting was restricted to the conformational epitope unique to ORF2.1 [Li
et al. (1997) Journal of Medical Virology 52:289-300], a pattern that was also
observed when comparing acute-phase patient serum samples with serum samples from
convalescing patients. Antibody from immunised rats blocked the majority of
patients' serum reactivity in enzyme-linked immunosorbent assay against both
ORF2.1 (57-92% inhibition) and virus-like particles of HEV produced using the
baculovirus system (74-97% inhibition). Together, these results suggest that the
ORF2.1 subunit vaccine induces an antibody response against immunodominant,
conformational epitopes in the viral capsid, which largely mimics that seen in
convalescent patients, who are presumed to be immune to HEV infection.
PMID- 10686020
TI - TT virus infection in patients with chronic hepatitis B or C: influence on
clinical, histological and virological features.
AB - Concomitant infection with TT virus and hepatitis B virus (HBV) or hepatitis C
virus (HCV) is common. However, the effect of TTV infection on chronic hepatitis
B or C is unknown. The prevalence of TTV infection, the effect of TTV infection
on the clinical, histological and virological features of patients with chronic
hepatitis B or C, and the influence of TTV infection on the HCV response to
interferon alfa therapy were studied. A total of 100 asymptomatic hepatitis B
surface antigen carriers, 220 patients with HBV-related chronic liver diseases,
and 110 patients with chronic hepatitis C treated with interferon alfa (3 million
units subcutaneously three times a week for 24 weeks) were enrolled. Serum HCV
RNA and serum TTV DNA were detected by the polymerase chain reaction (PCR). Serum
HBV DNA and serum HCV RNA level were quantified by branched DNA assays. Infection
with TTV was detected in 21.5% of HBV carriers and 37% of HCV carriers. TTV
infection had little effect on the clinicopathological course of chronic HBV
infection. In chronic hepatitis C, clinical features, histological severity,
serum HCV RNA levels, and the response to interferon alfa therapy did not differ
between those with and without TTV infection. The loss of serum TTV DNA did not
correlate with the biochemical response as did in the loss of serum HCV RNA. In
conclusion, TTV infection is found frequently in patients with chronic hepatitis
B or C in Taiwan; however, coinfection with TTV does not affect the
clinicopathological course of chronic hepatitis B or C and the response to
interferon alfa therapy.
PMID- 10686021
TI - Prevalence and risk factor analysis of TTV infection in prostitutes.
AB - TTV, a DNA virus, has been isolated from patients with non-A to non-E post
transfusion hepatitis. In the past it was assumed that TTV was transmitted
parenterally. It is unclear whether sexual contact leads to transmission of this
virus. In this study, two sets of TTV-specific polymerase chain reaction primers
were used to detect serum TTV DNA in 140 prostitutes and 136 controls. The
prevalence of TTV DNA in prostitutes was significantly higher than in the control
group (46/140 [32.9%] vs. 29/136 [21.3%]; P = 0.043). There was no significant
difference in the prevalence of positive antibody to hepatitis A virus (anti-HAV)
in either group (87.8% for prostitutes, 85.3% for controls). No particular risk
factor was significantly associated with positive TTV DNA in prostitutes. In
summary, TTV is highly prevalent in prostitutes. Transmission of TTV via sexual
contact is not as efficient as transmission of hepatitis C and D viruses and GB
virus-C hepatitis G virus. The high prevalence of TTV in controls indicates that
there are diverse routes of transmission of this virus.
PMID- 10686022
TI - Physical state and expression of human papillomavirus in laryngeal carcinoma and
surrounding normal mucosa.
AB - Epidemiologic and biomolecular evidence suggests that human papillomavirus (HPV)
infection may be associated with the development of head and neck cancers. To
clarify the role of HPV in larynx carcinoma, 25 patients were studied for the
presence of viral DNA, possible virus integration into the cellular genome, and
viral expression both in neoplastic tissues and in neighbouring normal mucosa.
Twelve of 25 patients with neoplasia (48%) showed negative results for HPV
sequences, and 13 (52%) showed positive results. Among the latter group of
patients, seven were HPV-16 positive, five were HPV-6, and one was HPV-45. No
multiple infections were detected. The physical status of the HPV genome was
analysed by three methods: polymerase chain reaction (PCR), bidimensional agarose
gel electrophoresis, and in situ hybridisation. Viral integration into the host
genome occurred in 43% of cases of HPV-16 and in 20% of cases of HPV-6. Viral RNA
expression was detected by reverse transcription-PCR only in HPV-16-positive
tumours. The pattern of expression was consistent with an active role of HPV in
cellular transformation. In conclusion, the present work suggests that HPV
infection may be involved in some cases of laryngeal carcinoma. However, the
transformation mechanisms might be different from those currently accepted for
anogenital cancers.
PMID- 10686023
TI - Seroresponses to human papillomavirus types 16, 18, 31, 33, and 45 virus-like
particles in South African women with cervical cancer and cervical
intraepithelial neoplasia.
AB - The aim of the study was to determine the prevalence of antibodies to human
papillomavirus (HPV) types 16, 18, 31, 33, and 45 in woman in Cape Town with
cervical intraepithelial neoplasia (CIN) (n = 95), cervical cancer (n = 40),
female blood donors (n = 95) and children (n = 110). The enzyme-linked
immunosorbent assay (ELISA) made use of baculovirus synthesised HPV virus like
particles (VLPs) as antigen. Antibodies to at least one HPV type were detected in
sera from 75% of cancer patients, 71.6% of CIN patients, 44.2% of blood donors
and 27.3% of children. Sera from 95 women with CIN were compared with age-matched
female blood donors. There was a significant association of seropositivity to VLP
16 (P = 0.006) and VLP-45 (P = 0.008) with CIN compared with the blood donors.
There was also a significant difference in the seropositivity of women with CIN
to any of the five virus-like particle (VLP) types compared to the blood donors
(P = 0.0002: OR = 3.2). Thirty-nine of sixty-nine (56.5%) women with CIN were
found to be HPV-16 DNA positive. The average age of women in this group that were
VLP-16 seropositive was 34 years and those found to be VLP-16 seronegative was 52
years of age. Antibodies to all five VLP types were detected in these
populations, thus an ideal vaccine should induce protection from infection by a
wide range of HPV types.
PMID- 10686024
TI - Epstein-Barr virus-specific antibodies in Epstein-Barr virus-positive and
negative gastric carcinoma cases in Japan.
AB - We examined Epstein-Barr virus (EBV)-specific antibodies in serum samples from 64
and 59 patients with EBV-positive and -negative gastric carcinomas, respectively,
and 73 healthy controls using immunofluorescence assays. EBV capsid antigen (VCA)
IgG and EBV-determined nuclear antigen (EBNA) IgG were detected in all 196
subjects. The geometric mean titer (GMT) of VCA-IgG, but not EBNA-IgG, was higher
in EBV-positive carcinoma cases than in EBV-negative carcinoma cases (P < 0.001).
The seroprevalence rates of VCA-IgA and EBV early antigen (EA) IgG were higher in
EBV-positive carcinoma cases than in EBV-negative carcinoma cases. Odds ratios
(ORs) comparing seroprevalence rates between EBV-positive and -negative carcinoma
cases were 3.4 (95% confidence interval [CI] = 1.3-8.8) and 6.6 (95% CI = 2.7
16.3) for VCA-IgA and EA-IgG, respectively. These results suggest that EBV
reactivation occurs in vivo, since more than 90% of Japanese are infected with
EBV in early childhood. The GMT of VCA-IgG in EBV-negative carcinoma cases was
higher than that of healthy controls (P = 0.028). The seroprevalence rates of EA
IgG were greater in EBV-negative carcinoma cases than in healthy controls (OR =
4.9, 95% CI = 1.2-19. 7). VCA-IgA was the only antibody that showed a
significantly high seroprevalence and GMT in EBV-positive carcinoma cases, but
not in EBV-negative carcinoma cases. Thus, VCA-IgA can be a marker of immune
response to EBV in EBV-positive carcinoma cases. Our findings support the
hypothesis that if EBV is involved in the development of EBV-positive gastric
carcinoma, the EBV reactivation occurs in vivo.
PMID- 10686025
TI - Augmentation of leukocyte infiltration in murine tumors expressing B-cell derived
but not nasopharyngeal carcinoma derived EBV membrane protein LMP1.
AB - The Epstein-Barr virus (EBV) encoded latent membrane protein of B cell origin, B
LMP1 (B95-8 prototype) and nasopharyngeal carcinoma (NPC) derived C-LMP1 (CAO
prototype) were transfected individually in S6C adenocarcinoma cells of ACA (H
2f) origin. We have shown previously that inoculation of B-LMP1 expressing S6C
cells led to tumor rejection in pre-immunized, immunocompetent syngeneic ACA
mice, whereas the C-LMP1 transfectants were not immunogenic. Furthermore, B-LMP1
but not C-LMP1 expressing S6C cells grew with necrosis and extensive skin damage
in non-immunized mice. A study was carried out to determine whether the in vivo
growth pattern of S6C cells expressing two different LMP1 isolates could be
correlated to any immunomodulatory mechanism. An increased infiltration of CD45+
leukocytes was found in B-LMP1 expressing S6C tumors originating in non
immunized, syngeneic ACA mice. The C-LMP1 expressors, vector transfectants and
untransfected parental tumors had significantly lower number of infiltrating
leukocytes. The immunoaccessory molecules ICAM-1, B7-1 and MHC Class I and II
expression was unaltered in both B- and C-LMP1 transfectants. The data suggest
that B-LMP1 but not C-LMP1 induce anti-tumor immune response.
PMID- 10686026
TI - Infection of five human liver cell lines by dengue-2 virus.
AB - Elevated serum transaminase levels of dengue patients indicate the possible
impact of dengue virus infection on liver function. To elucidate the action of
dengue virus infection in liver cells, an in vitro cell line system was
established that mimicked the liver status of diverse clinical patients. Briefly,
four hepatoma cell lines (HA22T, Huh7, Hep3B, and PLC) and one nonmalignant
hepatocyte cell line (Chang liver) were included, representing various levels of
tumorigenicity and differentiation. Our data showed that in these five cell
lines, dengue-2 virus attached to each cell type equally well; however, this
virus had higher replication rates and levels of virion production in
differentiated Huh7, PLC, Hep3B, and Chang liver cells. Likewise, a lower
replication rate was observed in the de-differentiated HA22T cells.
Differentiation-related factors seem to play an important role in dengue virus
replication. Further study showed that sodium butyrate (NaB, a differentiation
inducer) treatment enhanced dengue virus replication in HA22T cells. Moreover, we
found that the severity of morphologic aberration and the increase in aspartate
aminotransferase (AST) levels correlated with the virus replication rate in the
four infected hepatoma cells. In conclusion, we showed that dengue virus can
infect diverse liver cells with differing replication efficiency, which causes
cytopathic effects (CPEs) of diverse severity. Among the CPEs, the increased AST
levels correlated with the clinical results from 24 dengue fever patients, who
showed increased AST levels at the onset of fever. In summary, we find that
dengue-2 virus replicates actively and causes severe CPEs in differentiated
hepatoma cells. Factors related to differentiation as well as tumorigenicity seem
to play critical roles, though the mechanisms of action remain unclear.
PMID- 10686027
TI - Prospective study of the duration and magnitude of viraemia in children
hospitalised during the 1996-1997 dengue-2 outbreak in French Polynesia.
AB - The magnitude and duration of viraemia in children admitted to the hospital with
dengue was studied during a dengue 2 outbreak in French Polynesia in 1996-1997.
Forty-nine patients from whom at least 3 plasma samples were available were
included in the study. Based on analysis of IgG-ELISA and haemagglutination
inhibition assay, 21 of these were primary and 28 were secondary infections.
According to World Health Organization criteria, 42 were dengue fever and 7 were
dengue haemorrhagic fever. Virus was detectable by reverse transcription-PCR in
all patients for at least the first 3 days of the onset of fever, but was never
detected after the 6th day (mean duration = 4.4 days). Plasma virus titers ranged
from 1.7-5.6 Log(10) TCID(50)/ml. A significant difference was not observed in
the magnitude and duration of viraemia in patients with primary versus secondary
infections. The severity of the illness, however, was correlated with both
criteria.
PMID- 10686028
TI - A new enzyme immunoassay for the detection of enteroviruses in faecal specimens.
AB - A new enzyme immunoassay (EIA) for direct detection of enteroviruses based on a
group-specific monoclonal antibody was evaluated using stool samples from
patients with suspected enteroviral infection. The EIA was compared with
polymerase chain reaction (PCR) and virus isolation in cell culture. Of 204
samples tested, 20 were positive by EIA, 34 by PCR, and 18 by cell culture.
Compared with PCR, the most sensitive method, the sensitivity of EIA was 58%
(20/34); the sensitivity of cell culture isolation was 52% (18/34). The results
of both assays correlated in only 60% of cases. The combination of EIA and cell
culture isolation detected 76% of PCR-positive stool samples. Enterovirus EIA
provides results within 3-4 hr and requires only standard EIA equipment. It
represents a rapid, reliable, and cost-effective diagnostic tool for enterovirus
diagnosis from faecal samples. Negative results must be confirmed by other
techniques, such as PCR or virus isolation in cell culture.
PMID- 10686029
TI - A neutralizing recombinant human antibody Fab fragment against Puumala
hantavirus.
AB - A combinatorial human antibody Fab pComb3H library, generated from splenic
lymphocytes of a Puumala hantavirus (PUUV) immune individual, was selected
against PUUV using the phage display technique. Panning was carried out with
antigens immobilized by MAbs directed to the two PUUV envelope glycoproteins G1
and G2. Thirteen Fabs, with reactivity directed to PUUV and specifically the G2
protein, as assessed by immunofluorescence and ELISA respectively, were isolated
in crude preparations. By a focus reduction neutralization test (FRNT), four of
the 13 crude Fab preparations exhibited type-specific neutralization of PUUV
(strain Sotkamo) with 44-54% reduction in the number of foci. After affinity
purification, the four Fab clones exhibited 50% focus reduction of PUUV at
concentrations below 2 microg/ml. Sequencing of the heavy and light chain
complementarity determining regions (CDR) 1-3 showed that the four selected
clones were identical within the antibody binding regions. In inhibition tests
with the PUUV G2-specific MAbs, 4G2 and 1C9, a new epitope important for
neutralization, designated as G2-a3, was defined. This epitope, overlapping
partially the neutralizing epitope recognized by the human MAb 1C9, seems to be
unique for the PUUV serotype since none of the Fab clones neutralized any of the
other hantaviruses tested.
PMID- 10686030
TI - Quantitative analysis of cytomegalovirus load using a real-time PCR assay.
AB - A novel real-time PCR assay system was developed to quantify the cytomegalovirus
(CMV) genome load. The real-time PCR assay could detect from 6 to over 10(6)
copies of CMV-DNA with a wide linear range. The virus load of immunocompromised
patients with symptomatic CMV infections was quantified and compared to that of
asymptomatic ones. In symptomatic patients, all 17 peripheral blood leukocytes
were positive for CMV DNA, and its mean value was 10(3.3) copies/10(6) cells. On
the other hand, only 9 of 38 samples (24%) were positive in the asymptomatic
patients, and its mean titer was lower (10(2.0) copies/10(6) cells) than that of
the symptomatic group (P = 0.002). In plasma, the virus genome was detected in 13
out of 17 samples from symptomatic patients (76%), and its mean value was 10(4.0)
copies/ml. In contrast, for the asymptomatic group, only one out of 36 samples
were positive (3%). Finally, this system was used to monitor two patients with
CMV infections serially. The CMV DNA copy number changed with their clinical
symptoms and anti-CMV therapy, and virtually paralleled the result of the pp65
antigenemia assay in both cases. In one patient with the cord blood
transplantation, however, the CMV DNA became positive faster than the antigenemia
assay. These results indicate that this assay is sensitive and useful for
estimating the CMV genome load not only in peripheral blood leukocytes but also
in plasma. It can be very helpful for diagnosing CMV-related diseases and
monitoring the virus load in patients with CMV infections.
PMID- 10686031
TI - Diagnosis of Ebola haemorrhagic fever by RT-PCR in an epidemic setting.
AB - This study reports the first field evaluation of a new diagnostic technique for
Ebola virus disease with sensitivity and specificity. Ebola virus causes rare but
fulminating outbreaks in Equatorial Africa. Rapid differentiation from other
infections is critical for timely implementation of public health measures.
Patients usually die before developing antibodies, necessitating rapid virus
detection. A reverse transcriptase-polymerase chain reaction (RT-PCR) assay was
developed, implemented and evaluated at Centre International de Recherches
Medicales de Franceville (CIRMF) in Gabon, to detect Ebola viral RNA in
peripheral blood mononuclear cells (PBMC). Twenty-six laboratory-confirmed
patients during and 5 after the acute phase of Ebola haemorrhagic fever, 15
healthy controls and 20 febrile patients not infected with Ebola virus were
studied. RT-PCR results were compared with ELISA antigen capture, and Ebola
specific IgM and IgG antibody detection. Ebola virus RNA was amplified from 26/26
specimens from the acute phase, 3/5 during recovery, 0/20 febrile patients and
1/15 negative controls. Sensitivity of RT-PCR in identifying acute infection and
early convalescence compared with antigen or IgM detection was 100% and 91%
respectively, and specificity compared with antigen detection and IgM assay
combined was 97%. Antigen capture detected only 83% of those identified by PCR,
and IgM only 67%. Ebola virus RNA was detected in all 13 fatalities, only 5 of
whom had IgM and none IgG. RT-PCR detected Ebola RNA in PBMC one to three weeks
after disappearance of symptoms when antigen was undetectable. RT-PCR was the
most sensitive method and able to detect virus from early acute disease
throughout early recovery.
PMID- 10686032
TI - Evaluation of the antibody specificities of human convalescent-phase sera against
the attachment (G) protein of human respiratory syncytial virus: influence of
strain variation and carbohydrate side chains.
AB - The C-terminal third of the attachment protein (G) of several human respiratory
syncytial virus isolates was obtained as either a glycosylated protease-resistant
fragment of the purified protein or a nonglycosylated GST fusion protein
expressed in bacteria. The reactivity of human convalescent-phase sera with both
forms of the protein segment was evaluated in immunoblots. While all serum
samples reacted with the mature intact protein of the different isolates, only
certain samples reacted with the nonglycosylated C-terminal segment of some viral
isolates. The number of human serum samples reacting with the glycosylated C
terminal fragment was even more limited. These results highlight the
heterogeneity of the human antibody response against epitopes located in the C
terminal hypervariable region of the G molecule and the influence of carbohydrate
side chains for expression of these epitopes. We also have analysed the
specificities of human sera by competitive enzyme-linked immunosorbent assay with
murine monoclonal antibodies (MAbs). Most human serum samples inhibited virus
binding of MAbs that recognised conserved or group-specific epitopes of the G
protein, while only a limited fraction of those samples inhibited binding of MAbs
that recognised strain-specific epitopes. These results are discussed in terms of
the antibody repertoire induced after human respiratory syncytial virus infection
and the relevance of escape mechanisms to preexisting antibodies for the
evolution of this virus.
PMID- 10686033
TI - Expression of recombinant Norwalk-like virus capsid proteins using a bacterial
system and the development of its immunologic detection.
AB - The capsid protein of Norwalk-like virus (NLV) isolates NLV-36 (Mexico virus
type, genogroup II [GII]), NLV-21 (Lordsdale virus type, GII), NLV-114 (untyped
GII virus), and NLV-96-908 (KY89 virus type, GI) have been expressed in an
Escherichia coli system. The expressed recombinant NLV capsid proteins, fused
with maltose binding protein (MBP-rV) and thioredoxin (TRX-rV) in E. coli lysate,
were analyzed using sodium dodecyl sulfate-polyacrylamide gel eletrophoresis.
Rabbit IgG (R-IgG) in hyperimmune serum has been raised against MBP-rV-36 capsid
protein and was purified before further study. Detection of TRX-rVs using an
enzyme-linked immunosorbent assay (ELISA) showed that R-IgG had immunologic
reactivity to GII as well as to the GI rV capsid proteins TRX-rV-36, TRX-rV-21,
TRX-rV-114, and TRX-rV-96-908. Results of Western immunoblot (WB) analysis showed
the same broad recognition of R-IgG when using the same samples. The results of
the ELISA tests on serum samples obtained from patients involved in confirmed
outbreaks of NLV proved that expressed NLV capsid proteins in E. coli can be
detected by NLV-infected human serum. In addition, purified NLVs (LD virus types)
derived from patients' stool could be detected using anti-NLV R-IgG, whereas
normal R-IgG did not react when using WB. Our results strongly suggest that the
immunologic detection of NLV antigens using anti-rV R-IgG is possible and seems a
significant step toward simplification of an NLV detection test.
PMID- 10686034
TI - Evidence for the diagnosis of pancreatic insufficiency.
PMID- 10686035
TI - Long-acting beta(2)-agonists in childhood asthma: Don't change a winning team
(yet)
PMID- 10686036
TI - Evaluation of fecal pancreatic elastase-1 as a measure of pancreatic exocrine
function in children with cystic fibrosis.
AB - Pancreatic elastase-1 (EL-1) is a specific human protease synthesised by the
acinar cells. It is stable, unaffected by exogenous pancreatic enzyme treatment,
and correlates well with stimulated pancreatic function tests. We report our
experience of EL-1 measurements in 142 patients from a large cystic fibrosis (CF)
clinic. The median patient age was 7.7 years (range, 0.1-20.8 years), 93 were
homozygous and 38 heterozygous for DeltaF508, and 11 had other or unidentified
mutations. There were 85 non-CF control subjects. Seven were pancreatic
sufficient (PS). The median (quartile 1-quartile 3) fecal EL-1 of the 135
pancreatic insufficient (PI) patients was 10 microg/g stool (2.5-33); of the 7 PS
patients, 698 microg/g stool (400.5-824.5), and of the non-CF controls, 615
microg/g stool (420-773). Using the Mann-Whitney U test, there was a
statistically significant difference for fecal EL-1 activity between the PS and
PI patients (P = 0.0001) and the PI and control group (P < 0.0001), but not
between the control and PS groups (P = 0.63). Median (quartile 1-quartile 3)
fecal EL-1 in the pancreatic insufficient DeltaF508 homozygotes was 10 microg/g
stool (2-33), and in the heterozygotes 12 microg/g stool (4-39) (not significant,
P = 0.62). We now use fecal EL-1 as evidence of PI in screened CF infants
(reliable over the age of 2 weeks); in older CF patients at diagnosis; for
confirming the need for pancreatic enzymes in patients referred to the clinic
already taking enzymes; for annual monitoring of PS patients to detect the onset
of PI; and as supporting evidence when excluding the diagnosis of CF in patients
attending the pediatric gastroenterology clinic. The low values in the first 2
weeks in some normal and premature infants, and the persisting normal values in
PS infants, make the fecal EL-1 test unsuitable for neonatal CF screening.
PMID- 10686037
TI - Pseudomonas aeruginosa cross-infection among patients with cystic fibrosis during
a winter camp.
AB - Twenty-seven patients with cystic fibrosis from our Danish Cystic Fibrosis Center
went to a winter camp for 1 week in November of 1990. This study is based on 22
of these patients. Prior to attending camp, 17 out of 22 patients harbored
Pseudomonas aeruginosa in their sputum, but 5 patients did not. After returning
from camp, all 22 patients harbored P. aeruginosa in the sputum, including the 5
patients whose sputum was free of P. aeruginosa before they went. Epidemiological
typing used pulsed-field gel electrophoresis of the P. aeruginosa isolates was
performed. The typing results showed that the 5 cystic fibrosis patients who were
free of P. aeruginosa in their sputum prior to the winter camp had acquired P.
aeruginosa isolates identical to the P. aeruginosa strains isolated from the
other 17 cystic fibrosis patients. This constitutes a cross-colonization rate of
100%, the highest rate ever detected among patients with cystic fibrosis. We
conclude that separate holiday camps based on the infection status of the
patients with cystic fibrosis are necessary to avoid cross-infection of patients
not infected with P. aeruginosa.
PMID- 10686038
TI - Bronchiectasis in Alaska Native children: causes and clinical courses.
AB - Although bronchiectasis has become a rare condition in U.S. children, it is still
commonly diagnosed in Alaska Native children in the Yukon Kuskokwim Delta. The
prevalence of bronchiectasis has not decreased in persons born during the 1980s
as compared with those born in the 1940s. We reviewed case histories of 46
children with bronchiectasis. We observed that recurrent pneumonia was the major
preceding medical condition in 85% of patients. There was an association between
the lobes affected by pneumonia and the lobes affected by bronchiectasis. Eight
(17%) patients had surgical resection of involved lobes. We conclude that the
continued high prevalence of bronchiectasis appears to be related to extremely
high rates of infant and childhood pneumonia. Pediatr Pulmonol. 2000;29:182-187.
Published 2000 Wiley-Liss, Inc.
PMID- 10686039
TI - Effects of high-dose inhaled corticosteroids on bone metabolism in prepubertal
children with asthma.
AB - We studied the effect of inhaled corticosteroids on the increase in bone mineral
content in prepubertal children with asthma. Forty-eight asthmatic, prepubertal
children receiving either inhaled beclomethasone dipropionate or budesonide were
evaluated. Nine children of similar age not receiving inhaled steroids served as
controls. The average age of corticosteroid-treated children was 7.8 +/- 2.4
years, and of control children, 8.4 +/- 2.1 years (NS). The average dose of
inhaled corticosteroids in the treated children was 0.67 +/- 0.48 mg/m(2)/day,
and they were followed over a 9-20-month period. Total bone mineral content
(TBMC) was measured at baseline and after 9-20 months. A derived value for 12
months' TBMC was calculated, assuming that changes in TBMC were linear with the
passage of time. The change in TBMC over a 12-month period was 264 +/- 68 mg for
the corticosteroid-treated children and 330 +/- 84 mg for control children (P <
0.025). In a multiple regression analysis in which adjustments were made for the
effects of age, height, and weight, the change in TBMC in corticosteroid-treated
children was inversely related to the inhaled steroid dose/m(2)/day (P = 0.016).
The increase in the lumbar vertebral bone mineral density in control children was
also significantly greater than in the corticosteroid-treated children (P <
0.025). We conclude that inhaled steroids, at an average dose of 0.67
mg/m(2)/day, when used in the treatment of asthma reduce the acquisition of bone
mineral in prepubertal children.
PMID- 10686040
TI - Comparative study using oral solutions of bambuterol once daily or terbutaline
three times daily in 2-5-year-old children with asthma. Bambuterol Multicentre
Study Group.
AB - The aim of this study was to compare safety and efficacy of bambuterol
hydrochloride (10 mg) oral solution administered once daily in the evening with
terbutaline sulphate (0.075 mg/kg body weight) oral solution administered three
times daily in 2-5-year-old children with asthma. There were two treatment
groups: (2/3) of the patients received bambuterol and (1/3) received terbutaline.
The study was double-blind, randomized, and of a parallel group design, and it
lasted for 3 months after a 2-week run-in period. The primary objective was to
evaluate safety (adverse events, and changes in blood pressure, pulse rate,
hematology, and clinical chemistry parameters). Plasma concentrations of
terbutaline and/or bambuterol were also measured. Evaluation of efficacy (diary
card data) was a secondary objective. A total of 155 patients (range, 2-6 years;
3 patients were 6 years old at randomization) were treated with the study drugs;
104 patients received bambuterol and 51 patients received terbutaline. Both
treatments showed a good safety profile with respect to clinical and laboratory
tests, and they were generally well tolerated. Reported adverse events were mild
to moderate. There were no statistically significant differences between
treatment groups in any of the efficacy variables (diary variables: peak
expiratory flow (PEF), asthma symptoms, restlessness, other reported symptoms,
use of inhaled bronchodilators, and nighttime awakenings). For morning PEF, the
mean increase from run-in to treatment was 16.9 L/min in the terbutaline group
and 23.3 L/min in the bambuterol group. For evening PEF, the mean increase was
20.2 L/min in the terbutaline group and 20.6 L/min in the bambuterol group. In
conclusion, once-daily bambuterol is as safe and effective as terbutaline given
three times daily. The study also confirmed that bambuterol has a 24-hr duration
of action, and therefore its once daily administration, makes it a preferred
bronchodilator agent. Pediatr Pulmonol. 2000:29:194-201.
PMID- 10686041
TI - Effects of inhaled nitric oxide and surfactant treatment on lung function and
pulmonary hemodynamics in bronchoalveolar-lavage-induced respiratory failure.
AB - Our aim was to study whether inhaled nitric oxide (iNO) moderates respiratory
failure induced by bronchoalveolar lavage (BAL) without severe pulmonary
hypertension. The following successive treatments, interrupted by 20-30-min rest
periods, were given to piglets: iNO (20 ppm for 20 min), exogenous surfactant,
iNO, Nomega-nitro-L-arginine methyl ester (L-NAME), and iNO. The controls inhaled
NO first after L-NAME. Lung mechanics and hemodynamics were measured serially.
The pulmonary to systemic arterial pressure ratio decreased during iNO and tended
to increase after its discontinuation. In contrast, the iNO-induced decreases in
severity of respiratory failure were not reversible during the rest periods. In a
second experiment, iNO/placebo and surfactant containing (3)H-labeled dipalmitoyl
phosphatidylcholine were given to rabbits. The surfactant aggregates and the
surface activity from postmortem BAL, and extravascular lung water, were studied.
Inhaled NO improved the surface activity and increased the large surfactant
aggregates. There was no detectable decrease in extravascular lung water. The
results suggest that a low dose of iNO has a beneficial effect on the gas
exchange that is in part unrelated to its effect on the pulmonary vasculature.
PMID- 10686042
TI - In vitro activity of minocycline against respiratory pathogens from patients with
cystic fibrosis.
AB - Our objective was to determine the in vitro activity of minocycline against
isolates of Burkholderia cepacia (BC), Stenotrophomonas maltophilia (SM), and
Pseudomonas aeruginosa (PA) cultured from the respiratory tract of patients with
cystic fibrosis (CF). Cultures of BC, SM, and PA were isolated in a hospital
bacteriology laboratory from the sputum or oropharyngeal cultures obtained from
patients attending a Cystic Fibrosis Center, and were prospectively tested for in
vitro sensitivity to minocycline by Kirby-Bauer disk diffusion. From January 1994
to July 1995, 116 cultures from 61 patients had at least one of the three
pathogens; 9/61 (15%) patients had an isolate of BC, and 7/9 (78%) had an initial
isolate sensitive to minocycline, of which 3 were sensitive only to minocycline;
2 cultures were resistant to all antibiotics. Four of 7 patients with BC were
treated with minocycline; 3 patients developed resistant isolates 3-13 months
after therapy. Five of 61 patients (8%) had an isolate of SM: 4/5 (80%) of these
isolates were sensitive to minocycline, of which 1 was sensitive only to
minocycline. Fifty-five of 61 patients (90%) had at least one PA isolate, with
112 morphotypes recovered from 90 cultures: 40/112 morphotypes (36%) were
sensitive to minocycline, 65 (58%) were resistant, and 7 (6%) were intermediate
in sensitivity. We conclude that the marked in vitro activity of minocycline
against BC and SM isolated from patients with CF suggests that minocycline may
have an adjunct role in the antimicrobial therapy of multidrug resistant,
respiratory pathogens in CF.
PMID- 10686043
TI - Interrupter technique versus plethysmography for measurement of respiratory
resistance in children with asthma or cystic fibrosis.
AB - The purpose of the present study was to compare measurements of respiratory
system resistance by the interrupter method (Rrsint) with those of airway
resistance by plethysmography (Raw) in nonobstructed children with asthma or
cystic fibrosis (ratio of forced expiratory volume in 1 sec to vital capacity,
FEV(1)/VC >/=80% with a forced expiratory flow rate between 25-75% of forced
vital capacity, FEF(25-75) >/=75% of normal values) and in obstructed children
with the same diseases (FEV(1)/VC <80% and/or FEF(25-75) <75% of normal values).
Eighty-one children (47 asthmatics and 34 suffering from cystic fibrosis) aged 5
18 years (mean 11.2 +/- SD 3.4 years) were included in the study. For the overall
group, we observed generally lower values for Raw (4.7 +/- 2. 8 cmH(2)O.L(-).s)
than for Rrsint20 (extrapolation of the mouth pressure during occlusion to 40 ms
after interruption) (5.6 +/- 1.7 cmH(2)O.L(-1).s) (P < 0.02), or for Rrsint40
(extrapolation of the mouth pressure during occlusion to 60 ms after
interruption) (6.6 +/- 2.2 cmH(2)O.L(-1).s) (P < 0.001), but there was no
difference between Rrsint20 and Raw in the obstructed subgroup. Moreover, we
observed a correlation between the difference (Rrsint20 - Raw) expressed in
percentage of predicted values and the degree of obstruction estimated by
FEV(1)/VC (r = 0.56, P < 0.001). The differences between the specific resistances
(sRrsint20 - sRaw, sRrsint40 - sRaw) were also correlated with the severity of
the obstruction (r = 0.65, P < 0.001 and r = 0.57, P < 0.001, respectively). We
observed also that the tendency to underestimate resistance by Rrsint in
obstructed children was not the same in children with asthma and cystic fibrosis.
We conclude that the tendency of Rrsint, as measured with our method, to
underestimate airway obstruction appears to increase in proportion to the
severity of the airway obstruction.
PMID- 10686044
TI - Long-acting beta(2)-agonists in management of childhood asthma: A critical review
of the literature.
AB - This review assesses the evidence regarding the use of long-acting beta(2)
agonists in the management of pediatric asthma. Thirty double-blind, randomized,
controlled trials on the effects of formoterol and salmeterol on lung function in
asthmatic children were identified. Single doses of inhaled salmeterol or
formoterol cause prolonged bronchodilatation (>12 h) and extended
bronchoprotection against exercise-induced bronchoconstriction in children, some
children achieving full protection for more than 12 h. Heterogeneity in
bronchoprotection has been observed, and individual dose-titration may be
attempted. The onset of action of formoterol is comparable to salbutamol, while
salmeterol has a slower onset of action. Partial tolerance develops when long
acting beta(2)-agonists are used as regular treatment, including cross-tolerance
to short-acting beta(2)-agonists. Regular treatment with salmeterol in children
with or without corticosteroids provides statistically significant
bronchodilatation, but the degree of improvement in lung function or
bronchoprotection against exercise and nonspecific irritants is small with
regular use. There is no evidence of anti-inflammatory effects from inhaled long
acting beta(2)-agonists, which is reflected by unchanged or increased bronchial
hyperreactivity and no reduction of exacerbation rates. The evidence does not
support a recommendation for long-acting beta(2)-agonists as monotherapy, nor
does it support their general use as regular add-on therapy. In conclusion, long
acting beta(2)-agonists provide effective bronchodilatation and bronchoprotection
when used as intermittent, single-dose treatment of asthma in children, but not
when used as regular treatment. Future studies should examine the positioning of
long-acting beta(2)-agonists as an "as needed" rescue medication instead of short
acting beta(2)-agonists for pediatric asthma management.
PMID- 10686045
TI - Pneumocystis carinii isolated from lung lavage fluid in an infant with cystic
fibrosis.
AB - Pneumocystis carinii (P. carinii) cysts were identified in bronchoalveolar lavage
fluid from a 15-week-old child newly diagnosed with cystic fibrosis who presented
with bronchitis, pneumonia, and weight loss. The child was not infected with
human immunodeficiency virus (HIV), and there was no evidence of impaired
immunity or exposure to individuals with known or suspected P. carinii disease.
Culture of the lavage fluid also revealed pathogens typical of lung disease
associated with cystic fibrosis. It is suspected that the presence of P. carinii
in this patient represented a new acquisition, as has been described in
immunocompetent infants and children. Whether P. carinii infection complicated
cystic fibrosis-associated lung disease in this patient is unknown.
PMID- 10686046
TI - Right lung agenesis with left pulmonary artery sling.
AB - We report on a 2-month-old infant girl who had right pulmonary agenesis and an
unusual course of the left pulmonary artery. Computed tomography and cardiac
catheterization showed that the left pulmonary artery arose from the main
pulmonary artery, crossing the midline, and reaching the left lung via an
aberrant course between the esophagus and trachea. The coexistence of right
pulmonary agenesis and left pulmonary sling is extremely rare. Unlike in other
reports, our patient remained symptom-free and in good health, with normal growth
and development until age 2 years, when she died from complications during an
attack of bronchiolitis caused by respiratory syncytial virus.
PMID- 10686047
TI - Re: Rost et al. describing the effects of neck position on endotracheal tube
(ETT) location in low birth weight infants.
PMID- 10686048
TI - The authors respond.
PMID- 10686049
TI - Role of progestational agents in the treatment of undernourished patients with
cystic fibrosis.
PMID- 10686050
TI - Ibuprofen therapy in cystic fibrosis.
PMID- 10686051
TI - Response by author.
PMID- 10686052
TI - Editorial
PMID- 10686053
TI - Experiences in HCV-NAT screening prior to releasing cellular components by the
German Red Cross Blood Transfusion Service of Baden-Wurttemberg.
AB - In this report we present the accumulated data on nucleic acid testing (NAT) for
hepatitis C virus (HCV) RNA of blood donations by the Blood Transfusion Service
of Baden-Wurttemberg in the period between March 1997 and March 1999. An extra
barcoded blood sample was collected from each donor. Samples were tested by NAT
in mini-pools of maximally 96 samples. First-time and repeat donors were tested
separately. RT/HCV-PCR was performed with the COBAS HCV Amplicortrade mark,
versions 1.0 and 2.0 from Roche Diagnostic Systems. Many modifications have been
introduced to the original protocol since the implementation of NAT screening
aiming at an increase in the sensitivity and specificity of the assay. NAT
positive pools containing serologically positive samples were detected.
Initially, reactive pools were identified that could not be confirmed by
secondary pooling and single testing procedures. So far, no serologically
negative but NAT positive sample has been found.
PMID- 10686054
TI - Standardization: a progress report.
AB - The introduction of nucleic acid amplification technology (NAT) assays for the
detection of viral contamination of blood and blood products requires the
availability of well-characterized reference reagents. Working reagents for
hepatitis C virus RNA, hepatitis B virus DNA, HIV-1 RNA and human parvovirus B19
DNA have been established at NIBSC and at many other laboratories (both official
medicinal control laboratories and commercial laboratories). However, as these
reagents have been characterised independently, it is difficult to compare
results from assays using different working reagents. Recently, a WHO
International Standard was established for HCV RNA NAT assays. This standard has
been calibrated in International Units (IU) and provides a common standard
against which all working reagents can be calibrated. Collaborative studies to
characterise two further candidate International Standards for HBV DNA and HIV-1
RNA NAT assays have been completed.
PMID- 10686055
TI - Validation of HCV-NAT assays and experience with NAT application for blood
screening in Germany.
AB - Validation of HCV-NAT assays is an important prerequisite for the use of NAT for
screening plasma or blood donations. The main NAT features to be validated are
specificity, detection limit and robustness. Preliminary experience in Germany
obtained with different methodical and logistic approaches shows the feasibility
of HCV-NAT as a screening test for blood donations.
PMID- 10686056
TI - Assessment of validation studies from a fractionator's point of view.
AB - NAT testing has become an integral part in the safety programs of both plasma
fractionators and transfusion services. NAT testing for HCV RNA is now mandatory
for plasma fractionators in Europe and for transfusion services in Germany and
Austria. Before NAT testing of plasma could become mandatory, a defined
environment had to be created to allow comparison of different NAT procedures. To
create such an environment, international virus standards, as well as guidelines
for validation, assessment of robustness, and quality assurance of NAT have been
released. This paper is a critical review of currently available standards and
national reference preparations, detection limits, and national regulations of
NAT in view of the specific nature of NAT.
PMID- 10686057
TI - European multi-centre validation study of NucliSens Extractor in combination with
HCV Amplicor 2.0 assay for HCV-NAT screening of plasma pools.
AB - The NucliSens Extractor in combination with the 2.0 version of the Roche Cobas
HCV Amplicor test has been validated by five European blood screening
laboratories in a multi-centre study. For testing the performance characteristics
of this HCV-NAT method, the European Pharmacopoeia validation guidelines were
followed. The CLB VQC reference reagents were used for testing robustness and
sensitivity. After a technical improvement in the extraction stations, the
NucliSens Extractor appeared to be contamination-free as was proved by testing
negative controls alternating with samples containing a high HCV-RNA
concentration. The Pelicheck HCV-RNA genotype 1 dilution panel was tested 74
times in the five laboratories and an overall 95% detection limit of 80 genome
equivalents (geq)/ml was found. In one laboratory the Pelicheck panel was tested
in 25 runs and here a 95% detection limit of 32 geq/ml was achieved. In this
laboratory the Pelispy HCV-RNA run control samples of 140 geq/ml were
consistently picked up in all extractor stations. In addition the laboratories
have tested a WHO HCV-RNA genotype 1 standard dilution series 39 times and a
Pelicheck HCV-RNA genotype 3 reference panel in 32 test runs. The limiting
dilution analysis enabled us to compare the detection efficiency of the NucliSens
Amplicor method for the genoype 1 and genotype 3 isolates and to calibrate the
reference reagents against each other. The combined Nuclisens-Amplicor method was
found to detect the genotype 3 isolate in the Pelicheck HCV-RNA panels with 2-3
fold lower efficiency than the genotype 1 standard (assuming that the historical
calibration of the genotype 3 against the genotype 1 standard is correct). In
this study of a single method 1 IU of the WHO HCV-RNA standard was found to be
equivalent to 5.1 geq of the VQC HCV-RNA standard (95% confidence intervals 3.1
9.1 geq). To avoid confusion with the use of the CLB VQC reagents we accept the
NIBSC collaborative study in which calibration by a variety of methods showed
that the Pelispy 380 geq/ml run control is equivalent to 100 IU/ml of the WHO
standard. This multi-centre validation study demonstrates that the 95% detection
limit of the NucliSens HCV Amplicor method lies far below the detection limits
required by the international regulatory bodies.
PMID- 10686058
TI - Performance characteristics of the AmpliScreen HIV-1 test, an assay designed for
screening plasma mini-pools.
AB - This study evaluated the performance characteristics of the AmpliScreen(TM)Human
Immunodeficiency Virus-Type 1 (HIV-1) Test, Version 1.5, a test designed for
screening pools composed of samples from individual units of blood or plasma. HIV
1, hepatitis C (HCV) and hepatitis B (HBV) virus particles were simultaneously
extracted and concentrated from plasma by a multi-prep sample processing
procedure. An HIV-1 Internal Control (IC) RNA was added to each sample to serve
as an extraction and amplification control. Processed samples were amplified by
RT-PCR using HIV-1-specific complementary primers and detected by hybridization
of the amplified products to HIV-1- and IC-specific oligonucleotide probes. The
analytical sensitivity of the test (concentration that yields >/=95% positive
results in a set of replicate tests) was 25 copies of HIV-1 RNA per mL of pooled
plasma. Representative strains from all HIV-1 group M subtypes were reproducibly
detected (>95% positive results among 22 replicate tests) at concentrations of 30
to 75 viral particles per ml. The test exhibited excellent specificity; it did
not cross-react with a set of 30 viral and five bacterial isolates and yielded
negative results on a panel of 500 blood samples from HIV-1 seronegative donors.
Samples containing abnormally high levels of haemoglobin, albumin, triglycerides
or bilirubin in plasma samples did not interfere with the detection of HIV-1 RNA
at a concentration of 100 copies of per ml. The test detected HIV-1 RNA 7-17 days
prior to anti-HIV-1 antibody seroconversion for all 10 seroconversion panels
tested. A fully automated COBAS AmpliScreen(TM)version of this test is being
validated. COBAS AmpliScreen tests for HCV and HBV also incorporate the multi
prep specimen processing method, thereby making it possible to use a single
processed specimen to screen for all three viruses.
PMID- 10686059
TI - Safety issues for plasma derivatives and benefit from NAT testing.
AB - Manufacturing processes for plasma derivatives are in general highly effective
for removal or inactivation of enveloped viruses and the products are safe with
regard to the clinically important viruses HIV, HCV and HBV. They are not so
effective for the elimination for non-enveloped viruses, especially Parvovirus
B19 (B19). A certain risk remains of B19 contamination for some plasma
derivatives that is caused, firstly, by the occurrence of highly contaminated
donations (up to 10(14)genomes/ml) and secondly, by the extreme heat resistance
and small size of B19 which makes it difficult to remove or inactivate. NAT is a
beneficial tool for detection of virus contamination. It is routinely used for
the detection of HCV-RNA in plasma pools, thereby preventing the processing of
HCV-RNA positive material. NAT assays may also be valuable for testing the
removal of viruses during manufacturing. This may be especially important if a
virus cannot be tested by infectivity assays.
PMID- 10686060
TI - NAT: perspectives for cellular components.
AB - The introduction of routine testing to detect viral genomes in donated blood was
originally driven by requirements for plasma fractionation in relation to
exclusion of hepatitis C virus (HCV) RNA. Nevertheless, it was obvious from the
outset that a dual standard for fractionated products and individual blood
components would be untenable. In many countries therefore, planning for
introduction of nucleic acid testing (NAT) of blood incorporated progression to
release of HCV RNA tested components. HCV was singled out because of its long
seronegative 'window period', relatively high prevalence and incidence in blood
donors, rapid burst time and high genome copy number during seroconversion. The
latter properties made HCV particularly suitable for detection in pools of
samples. If HCV RNA testing is required for release of labile components such as
platelets, rapid provision of NAT results is vital because of short shelf life of
platelets and the problems of delays when resolving the infectious unit in a
reactive pool. For NAT release of labile components smaller sample pool sizes
allow faster resolution of RNA positive units. Smaller pools involve high test
throughput, the likely need for more testing laboratories and ensuing increased
costs. Single sample testing is the ultimate extrapolation of reducing sample
pool size. With reduced pool sizes or single sample testing, the option of
testing for other viruses (e.g. HIV or HBV) singly or in multiplex also arises.
The cost-benefit and incremental yield of such strategies in the light of 'combo'
assays for HIV Ag/Ab and the recently described HCV Ag assay will require careful
and objective assessment, together with re-appraisal of anti-HBc screening for
detection of HBV infected donors at the "tail-end" of carriage.
PMID- 10686061
TI - Assessment of needs for plasma for fractionation in Europe.
AB - In the early 1990s, a series of outbreaks of hepatitis C (HCV) infections
clustering among recipients of certain lots of plasma-derived medicinal products
(PDMP) alarmed regulatory authorities, manufacturers and the public alike. Also,
a few episodes of Hepatitis A (HAV) infections occurred in haemophiliacs
receiving solvent-detergent-treated factor VIII concentrates. Thus, several
measures were brought into effect to reestablish the safety of the incriminated
products and to further increase the margin of safety of PDMP in general.
Therefore, intramuscular immunoglobulins had to be free of HCV RNA as shown by
nucleic acid amplification technology (NAT) in the final products. Furthermore,
the manufacturing process of PDMP had to be validated for both viral inactivation
and elimination. Finally, HCV-NAT was to be standardised and implemented as a
validated test of plasma pool samples. In 1994, a joint meeting of EPFA, EAPPI
and Regulatory Authorities was held in Brussels to outline the state of the art
and to delineate the actions to be taken. Five years later, in 1999, the
incidence rates of HIV, HBV and HCV in unpaid blood donors have been minimized,
especially in European countries. With probabilities for window period donations
as low as 0.6 in 1 million for both HIV and HCV and 2.1 in 1 million for HBV in
Switzerland, labile blood products have reached extreme, but not absolute safety.
The introduction of HCV-NAT roughly doubles this safety resulting in a 1 in 3
million probability of a window donation.Concomittantly, extensive viral
validation studies document effective inactivation and removal of viruses in
PDMP. The demonstrated margins of safety, expressed as logarithmical reduction
factors (LRF), range from 4 to over 20 log(10), depending on product, virus, and
inactivation procedure used. Further progress to even safer PDMP shall be
acomplished by consolidating the GMP processes, abandoning of obsolete
requirements and harmonising national regulations within Europe. Before
introducing new measures for additional agents such as HAV or Parvovirus B 19,
gains and risks and even potential new threats have to be carefully assessed.
Alternative efforts for the safeguard of patients, e.g. vaccination for HAV, need
to be balanced against the risks of changing established and validated
manufacturing procedures of PDMP with long-lasting safety records.
PMID- 10686062
TI - Risk-benefit analysis of nucleic acid testing: the French experience.
PMID- 10686063
TI - Sixth EPFA/NIBSC workshop on NAT in rome 1999: outcome of discussions.
AB - The sixth international workshop on "Nucleic Acid Amplification Technology for
the Detection of Blood Borne Viruses" was held on 5-6 May 1999 at the Istituto
Superiore di Sanita in Rome, Italy. The purpose of the workshop was to bring
together regulators, blood and plasma product manufacturers, national control
agencies, test kits manufacturers and scientists to discuss recent experience as
well as regulatory topics related to the use of NAT for the detection of blood
borne viruses. Various papers were presented and discussed in 6 sessions.
PMID- 10686064
TI - Contents and index to vol. 27
PMID- 10686065
TI - Induction by synaptic zinc of heat shock protein-70 in hippocampus after kainate
seizures.
AB - Following seizures, heat shock protein (HSP)-70 is induced in various brain
regions. Since zinc that can induce HSP-70 in various cell systems is enriched in
certain glutamatergic terminals and translocates to postsynaptic neurons with
seizures, we examined the possibility that HSP-70 induction in the epileptic
brain is mediated by synaptic zinc. Adult rats were injected intraperitoneally
with kainate to induce seizures. Seizures were halted 3 h after the kainate
administration by the injection of phenytoin. Staining of brain sections with
zinc-specific fluorescent dye TFL at 24 h after the kainate injection revealed a
one-to-one correlation between dense TFL fluorescence and acidophilic neuronal
degeneration in the hippocampus. Subsequent staining with anti-HSP-70 antibody,
however, revealed that more numerous neurons than degenerating neurons exhibited
HSP-70 immunoreactivity. Most of the HSP-70(+) neurons were not stained with acid
fuchsin but exhibited mild zinc fluorescence in the cytoplasm. Intraventricular
injection of CaEDTA attenuated neuronal death as well as the HSP-70 induction in
a dose-dependent manner. Supporting the specificity of zinc rather than calcium
as the inducer of HSP-70 in neurons, exposure to zinc but not to a calcium
ionophore or excitotoxins increased expression of HSP-70 mRNA and protein in
cultured cortical neurons. The present results suggest that not only selective
neuronal death, but also HSP-70 induction in neurons after seizures, is mediated
by the translocation of endogenous synaptic zinc.
PMID- 10686066
TI - Differential effects of BDNF, ADNF9, and TNFalpha on levels of NMDA receptor
subunits, calcium homeostasis, and neuronal vulnerability to excitotoxicity.
AB - Calcium influx through N-methyl-d-aspartate (NMDA) receptors can result in
neuronal apoptosis or necrosis and may play a pivotal role in neuronal death in
many different neurodegenerative diseases. In the present study we employed
primary neuronal cultures and three different excitoprotective factors, brain
derived neurotrophic factor (BDNF), activity-dependent neurotrophic factor
(ADNF9), and tumor necrosis factor alpha (TNFalpha), to elucidate the mechanisms
whereby trophic factors modify the excitotoxic process. Neurons pretreated with
BDNF exhibited increased levels of the NMDA receptor subunits NR1 and NR2A, which
was associated with increased calcium responses to NMDA and vulnerability to
excitotoxic necrosis and reduced vulnerability to apoptosis. ADNF9 and TNFalpha
suppressed calcium responses to glutamate and protected neurons against both
excitotoxic necrosis and apoptosis, but had no effect on levels of NMDA receptor
subunits. Inhibition of phosphorylation and DNA binding of NF-kappaB, by H7 and
kappaB decoy DNA, respectively, suggest that the excitotoxic-modulating actions
of BDNF are mediated by kinases, while those of ADNF9 and TNFalpha are mediated
by both kinases and the transcription factor NF-kappaB. Our data show that,
whereas BDNF increases neuronal responses to glutamate while ADNF9 and TNFalpha
decrease the same, all three protect against excitotoxic apoptosis.
PMID- 10686067
TI - Transduction of human GAD67 cDNA into immortalized striatal cell lines using an
Epstein-Barr virus-based plasmid vector increases GABA content.
AB - The M213-20 and M213-1L cell lines were immortalized from rat striatum using the
tsA58 allele of the SV40 large T antigen, contain the GAD enzyme, and produce
GABA (Giordano et al., 1994, Exp. Neurol. 124:395-400). Cell lines that produce
large amounts of GABA may be useful for transplantation into the brain in
conditions such as Huntington's disease or epilepsy, where localized application
of GABA may be of therapeutic value. We have explored the potential use of the
pREP10 plasmid vector, which replicates episomally, to increase GAD expression
and GABA production in M213-20 and M213-1L cells. Human GAD(67) cDNA was
transfected into M213-20 and M213-1L, and subclones were isolated with hygromycin
selection. Immunochemical studies showed increased GAD(67) expression compared to
the parent M213-20 and M213-1L cell lines. Staining for the EBNA antigen and
Southern blots demonstrated that the pREP10 plasmid was stably maintained in the
cells for at least 12-15 months in culture. Several clones were isolated in which
GABA concentrations were increased by as much as 4-fold (M213-1L) or 44-fold
(M213-20) compared to the parent cell lines or 12-fold (M213-1L) and 94-fold
(M213-20) greater than rat striatal tissue (1.678 +/- 0.4 micromol/g prot). The
ability of these cells to continue to produce large amounts of GABA while being
maintained in culture for extended periods suggests that similar methods might be
used with human cell lines to produce cells that can be transplanted into the
brain to deliver GABA for therapeutic purposes.
PMID- 10686068
TI - Persistent CREB phosphorylation with protection of hippocampal CA1 pyramidal
neurons following temporary occlusion of the middle cerebral artery in the rat.
AB - Phosphorylation of the DNA-binding transcription factor, cyclic AMP response
element binding protein (CREB), was immunohistochemically examined in rat brain
hippocampal CA1 in order to examine the ischemic vulnerability of this region
from the viewpoint of CREB activation. The rat brain had been subjected to 90-min
focal ischemia followed by various periods of recirculation. Focal ischemia was
induced by occlusion of the middle cerebral artery using the intraluminal suture
method. CA1 pyramidal neurons in the sham animals showed definite
immunoreactivity with anti-CREB antibody, which binds to both unphosphorylated
and phosphorylated CREB, while reactivity with anti-phosphorylated CREB antibody
was barely detectable in these neurons. In contrast, at 3.5 h of recirculation, a
significant increase in the number of phosphorylated CREB-positive neurons was
noted in the CA1 on both sides, and the increase continued until 48 h of
recirculation with a tendency for gradual decline. At each period, the ischemic
side showed a more marked increase in the number of immunoreactive cells as
compared to the nonischemic side. Cresyl violet staining revealed CA1 pyramidal
neurons to be maintained intact until 14 day of recirculation, at which time CREB
phosphorylation has returned to the control level. Transient global ischemia is
known to induce only mild CREB phosphorylation in the CA1 followed by a frank
neuronal loss in this region. These data suggest that CREB phosphorylation can be
persistently activated in CA1 neurons after focal ischemia and that this
phenomenon may be closely associated with protection of these neurons.
PMID- 10686069
TI - Neuroprotective and neurodestructive functions of nitric oxide after spinal cord
hemisection.
AB - Nitric oxide (NO) may subserve different functions in different central neurons
subjected to axotomy. The difference may depend on whether the neurons basally
express neuronal nitric oxide synthase (nNOS), a biosynthetic enzyme of NO. This
is supported by our previous finding that suggests the differential role of NO in
neurons of nucleus dorsalis (ND) and red nucleus (RN) which have different basal
expression of nNOS. This study aimed to establish firmly the functions of NO, as
revealed by nNOS immunoreactivity and nicotinamide adenine dinucleotide phosphate
diaphorase (NADPH-d) histochemistry, by the administration of endogenous NO
donor, l-arginine (l-arg), and NOS inhibitor, l-N(G)-nitroarginine methyl ester
(l-NAME). To relate the role of NO to glutamate receptors (GluR), the
distributions of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
receptor (AMPAR) and N-methyl-d-aspartate receptor (NMDAR) in the two nuclei were
revealed by immunohistochemical techniques. nNOS immunoreactivity was void in ND
neurons, but expressed weakly in the RN normally. It was induced in ipsilateral
ND neurons and upregulated on both sides of RN after spinal cord hemisection.
Neuronal loss in the ipsilateral ND was augmented by l-arg, but reduced by l
NAME. In the contralateral RN, l-arg attenuated neuronal loss. NMDAR1 was present
in most neurons in ND. After axotomy, some NMDAR1 immunoreactive neurons of the
ipsilateral ND were induced to express NOS, whereas RN neurons showed strong
staining for NMDAR1 and all the AMPA subunits. Most of the NOS-positive neurons
in the RN were coexistent with GluR2 in normal rats and those subjected to
axotomy. The present data demonstrated that NO exerted neurodestructive function
in the non-NOS-containing ND neurons characterized by NMDAR as the predominant
glutamate receptor. NO might be beneficial to the NOS-containing RN neurons. This
could be attributed to the presence of GluR2. Possible diverse synthesizing
pathways of NO in two different central nuclei were suggested from the
observation that NOS was colocalized with NADPH-d in ND neurons, but not in RN
neurons.
PMID- 10686070
TI - Conditionally immortalized cell lines, engineered to produce and release GABA,
modulate the development of behavioral seizures.
AB - Transplantation of genetically engineered cells can provide sustained focal
delivery of naturally occurring molecules, including neurotransmitters and growth
factors. We have engineered immortalized mouse cortical neurons and glia to
deliver GABA by driving GAD(65) expression. Engineered cell lines showed GAD(65)
mRNA expression, enzymatic activity, and GABA release. In vitro, basal flux of
GABA was approximately 20% of total cellular GABA. We transplanted these GABA
producing cells bilaterally into either the anterior or the posterior substantia
nigra of 43 rats. The rats were subsequently kindled through an electrode placed
in the entorhinal cortex. GABA-producing cells, but not beta-galactosidase
producing cells, affected kindling rates. The number of stimulations needed to
reach the first stage-5 seizure and to achieve full kindling differed
significantly between the anterior and posterior transplantation sites when
GAD(65)-producing cells were transplanted but not when beta-galactosidase
producing cells were transplanted. Our data show that transplanted engineered
cells can make and release GABA at physiologically meaningful concentrations.
PMID- 10686071
TI - An in vivo quantifiable model of cochlear neuronal degeneration induced by
central process injury.
AB - In the available in vivo experimental models for cochlear neuronal degeneration,
the peripheral (hair cell side) process of the cochlear nerve has been injured in
order to induce neuronal degeneration. However, there has been no dependable
experimental model in which cochlear neuronal degeneration begins from the
central (brain stem side) process. This lack of a central process injury model
has probably been due to the experimental difficulties that had to be overcome in
order to reproducibly and selectively injure the central process of the cochlear
neurons while maintaining the patency of the internal auditory artery in small
experimental animals such as rats. Using rats, we first developed a central
process injury model in which the reduction of the spiral ganglion cells due to
retrograde degeneration of cochlear neurons can be quantitatively evaluated. In
our experimental model, the cochlear nerve was compressed and injured by a
compression-recording (CR) electrode placed at the internal auditory meatus.
First, the cochlear nerve was compressed until the compound action potentials of
the cochlear nerve became flat, and then the CR electrode was advanced by various
compression speeds (5, 10, or 200 micrometer/s) to reach the same depth (400
micrometer). In our model, therefore, the reduction of the spiral ganglion cells
was caused compression speed dependently. This method made it possible to produce
compression injury to the cochlear nerve without evidence of damage to the blood
supply to the cochlea via the internal auditory artery. This model gives us the
means to obtain knowledge that was previously impossible to derive from the
peripheral process injury models.
PMID- 10686072
TI - Sequential administration of GDNF into the substantia nigra and striatum promotes
dopamine neuron survival and axonal sprouting but not striatal reinnervation or
functional recovery in the partial 6-OHDA lesion model.
AB - Glial cell line-derived neurotrophic factor (GDNF) has prominent survival
promoting effects on lesioned nigrostriatal dopamine neurons, but understanding
of the conditions under which functional recovery can be obtained remains to be
acquired. We report here the time course of nigrostriatal axon degeneration in
the partial lesion model of Parkinson's disease and the morphological and
functional effects of sequential administration of GDNF in the substantia nigra
(SN) and striatum during the first 5 weeks postlesion. By 1 day postlesion, the
nigrostriatal axons had retracted back to the level of the caudal globus
pallidus. Over the next 6 days axonal retraction progressed down to the SN, and
during the following 7 weeks 74% of tyrosine hydroxylase-positive (TH(+)) and 84%
of retrogradely labeled nigral neurons were lost, with a more pronounced loss in
the rostral part of the SN. GDNF administration protected 70 and 72% of the
nigral TH(+) and retrogradely labeled cell bodies, respectively, but did not
prevent the die-back of the lesioned nigrostriatal axons. Although clear signs of
sprouting were observed close to the injection site in the striatum as well as in
the globus pallidus, the overall DA innervation of the striatum [as measured by
[(3)H]-N-[1-(2-benzo(b)thiopenyl)cyclohexyl]piperidine-binding autoradiography]
was not improved by the GDNF treatment. Moreover, the lesion-induced deficits in
forelimb akinesia and drug-induced rotation were not attenuated. We conclude that
functional recovery in the partial lesion model depends not only on preservation
of the nigral cell bodies, but more critically on the ability of GDNF to promote
significant reinnervation of the denervated striatum.
PMID- 10686073
TI - The neurotoxicity of the venom phospholipases A(2), notexin and taipoxin.
AB - The presynaptically active, toxic phospholipases known as notexin and taipoxin
are principal components of the venom of the Australian tiger snake and the
Australian taipan respectively. The inoculation of the toxins into one hind limb
of rats caused, within 1 h, the depletion of transmitter from the motor nerve
terminals of the soleus muscle. This was followed by the degeneration of the
motor nerve terminals and of the axonal cytoskeleton. By 24 h 70% of muscle
fibers were completely denervated. Regeneration and functional reinnervation were
almost fully restored by 5 days, but collateral innervation was common in the
regenerated muscles, and this abnormality persisted for at least 9 months. The
data provide an explanation for both the severity of neuromuscular paralysis that
can accompany envenoming bites by tiger snakes and taipans and the difficulty
experienced by physicians in managing the envenomed subjects.
PMID- 10686074
TI - Abeta42-carboxy-terminal-like immunoreactivity is associated with intracellular
neurofibrillary tangles and pick bodies.
AB - Co-occurrence of neurofibrillary tangles (NFTs) and beta-amyloid (Abeta)
containing plaques is the pathological hallmark of Alzheimer's disease (AD). Much
research has been carried out to elucidate the possible interactions of these two
characteristic lesions. Here we show by immunohistochemistry that an Abeta42
carboxy-terminal-like epitope (tAbeta42) is associated with NFTs at an early,
intraneuronal stage. The NFTs immunoreactive for tAbeta42 were also positive for
tau2. tAbeta42 NFTs occurred even in cases without plaques or any other form of
extracellular Abeta deposits. NFTs were tAbeta42 immunoreactive under all tangle
forming conditions studied: AD, the parkinsonism dementia complex of Guam,
progressive supranuclear palsy, and elderly controls. In Pick disease, which is
another "tauopathy" Pick bodies and ballooned neurons were found to be
immunoreactive for tAbeta42. Appearance of an epitope of Abeta in neurons at such
an early stage of tangle formation and in Pick bodies may indicate a direct
connection of Abeta42 and cytoskeletal disarrangement, although cross-reactivity
with other epitopes cannot be ruled out.
PMID- 10686075
TI - Survival of grafted fetal neural cells in kainic acid lesioned CA3 region of
adult hippocampus depends upon cell specificity.
AB - We hypothesize that the degree of graft cell survival within the damaged CNS
correlates with the specificity of donor cells to the region of grafting. We
investigated graft cell survival following transplantation of fetal micrografts
into the CA3 region of the adult rat hippocampus at a time-point of 4 days after
an intracerebroventricular administration of kainic acid (KA). Grafts consisted
of 5'-bromodeoxyuridine (BrdU) labeled embryonic day (E) 19 cells from
hippocampal fields CA3 and CA1 and E15 and E19 cells from the striatum. Absolute
cell survival in these grafts was quantitatively analyzed at 1 month
postgrafting, using BrdU immunostaining of serial sections and three-dimensional
reconstruction of grafts. Absolute graft cell survival in lesioned CA3 was
dramatically greater for cells having hippocampal origin (CA3 cells, 69% cell
survival; CA1 cells, 42% cell survival) than those having nonhippocampal origin,
such as striatal cells (E15 cells, 12% cell survival; E19 cells, 4% cell
survival). This difference is in sharp contrast to survival of these cells in
culture, where E19 cells from both hippocampal and nonhippocampal origins
exhibited similar survival. Comparison of survival among hippocampal cell types
indicated significantly greater survival for cells that are specific to the
lesioned area (i.e., CA3 cells) than for those that are nonspecific to the
lesioned area (i.e., CA1 cells). Graft cell survival in the intact CA3 region
(contralateral to KA administration), however, did not differ either between
cells having hippocampal and nonhippocampal origins or between CA3 and CA1 cells
(CA3 cells, 26% cell survival; CA1 cells, 33% cell survival; and E15 striatal
cells, 20% cell survival). These results underscore the finding that enhanced
survival of fetal cell grafts in the lesioned CNS is critically dependent upon
the specificity of donor fetal cells to the region of transplantation. Thus,
grafting of cells that are specific to the lesioned area is a prerequisite for
achieving maximal graft cell survival and integration in the lesioned host CNS.
PMID- 10686076
TI - Netrin-1 and peripheral nerve regeneration in the adult rat.
AB - Axonal guidance during development of the nervous system is thought to be highly
regulated through interactions of axons with attractive, repulsive, and trophic
cues. Similar mechanisms regulate axonal regeneration after injury. The netrins
have been shown to influence the guidance of several classes of developing axons.
Although netrins have been implicated as axonal guidance cues in the developing
peripheral nervous system, there has been no direct evidence of netrin-1
expression in either developing or adult peripheral nerve. The present study
utilized competitive PCR and immunohistochemistry to demonstrate the localization
of netrin-1 within adult rat sciatic nerve. The expression of netrin-1 mRNA and
protein was compared for normal or regenerated sciatic nerve 2 weeks following
either a crush or a transection and repair injury. The PCR data show that netrin
1 mRNA is normally expressed at low levels in peripheral nerve, and similar low
levels are found 2 weeks following a crush injury. However, 2 weeks following
nerve transection and repair there is approximately a 40-fold increase in netrin
1 mRNA levels. Immunohistochemistry data show that Schwann cells are the major
source of netrin-1 protein in peripheral nerve. Our results suggest that netrin-1
mRNA levels are profoundly affected during peripheral nerve injury and
regeneration. The localization of netrin-1 to Schwann cells suggests that this
protein is strategically situated to influence axon regeneration in adult
peripheral nerve.
PMID- 10686077
TI - Nerve guides seeded with autologous schwann cells improve nerve regeneration.
AB - This study evaluates the ability of Schwann cells (SCs) transplanted into a nerve
guide to improve regeneration and reinnervation after sciatic nerve resection and
repair, leaving a 6-mm gap, in the mouse. SCs were isolated from predegenerated
adult sciatic nerves and expanded in culture using a chemically defined medium.
Syngeneic, isogeneic, and autologous SCs were suspended in Matrigel and seeded in
resorbable, permeable poly(l-lactide-co-epsilon-caprolactone) guides at 150,000
cells/tube. Guides containing SCs were compared to guides filled with Matrigel
alone and with peroneal nerve autografts. Functional reinnervation was assessed
by noninvasive methods to determine recovery of sweating, nociceptive, sensory,
and motor functions in the hindpaw during 4 months postoperation. Morphological
analysis of the regenerated nerves was performed at the end of follow-up. The
group with an autograft achieved faster and higher levels of reinnervation and
higher number of regenerated myelinated fibers than groups repaired by
tubulization. The immunogenicity of transplanted SCs influenced the outcome of
nerve regeneration. Transplants of autologous SCs resulted in slightly lower
levels of reinnervation than autografts, but higher recovery and number of
regenerated fibers reaching the distal nerve than transplants of isologous and
syngeneic SCs, although most of the differences were not statistically
significant. Syngeneic SCs did not improve regeneration with respect to acellular
guides. Prelabeled transplanted SCs were found to survive into the guide 1-3
months after implantation, to a larger number when they were autologous than
syngeneic. Cellular prostheses composed of a resorbable guide seeded with
autologous SCs appear as an alternative for repairing long gaps in injured
nerves, approaching the success of autografts.
PMID- 10686078
TI - Coexpression of nestin in neural and glial cells in the developing human CNS
defined by a human-specific anti-nestin antibody.
AB - The presence of the intermediate filament protein nestin has been the predominant
marker used to describe stem and progenitor cells in the mammalian CNS. In this
study, a 998-bp fragment in the 3' region of the nestin mRNA was cloned from
human fetal brain cells (HFBC). The nucleotide sequence of the cloned cDNA
revealed 21 differences with the previously published human nestin sequence,
resulting in 17 amino acid changes. A 150-amino-acid fragment derived from the
cloned nestin cDNA was coupled to glutathione S-transferase and used as an
immunogen to generate a rabbit polyclonal antiserum that selectively detects
human nestin. HFBC that proliferated in response to basic fibroblast growth
factor incorporated 5-bromo-2'-deoxyuridine into their nuclei and immunostained
for nestin, indicating nestin expression in proliferating CNS progenitor cells.
In all cell cultures, nestin costained with the neuroepithelial cell marker
vimentin. A small subset of nestin-stained cells (1-2%) immunostained with
neuronal marker MAP-2 during the first week and after 4 weeks in culture.
However, during the first week in culture, approximately 10-30% of the total cell
population of HFBC stained for the glial cell marker GFAP, and nearly all
coimmunostained for nestin. After 4 weeks in culture, a subset of GFAP-positive
cells emerged that no longer costained with nestin. These results describe nestin
expression not only in CNS progenitor cells but also in the cells which were in
transition from a progenitor stage to glial differentiation. Collectively, these
data suggest a differential temporal regulation of nestin expression during glial
and neuronal cell differentiation.
PMID- 10686079
TI - Contraction-induced muscle fiber damage is increased in soleus muscle of
streptozotocin-diabetic rats and is associated with elevated expression of brain
derived neurotrophic factor mRNA in muscle fibers and activated satellite cells.
AB - The expression of brain-derived neurotrophic factor (BDNF) is elevated in the
soleus muscle of streptozotocin-diabetic rats. To determine whether this diabetes
induced elevation was associated with or enhanced by muscle activity we have
induced high-intensity muscle contraction by electrically stimulating the sciatic
nerve. In 6-week diabetic rats, intense contraction of the soleus muscle resulted
in a two- to four-fold elevation of BDNF mRNA and increased plasma levels of
creatine kinase that were associated with severe focal muscle fiber damage and
concomitant satellite cell activation. Focal muscle fiber damage and concomitant
satellite cell activation were also observed in the soleus muscle of
nonstimulated diabetic rats, but to a much lesser extent. No effects of muscle
contraction, i.e., experimentally induced or during normal daily activity, on
muscle fiber structure or BDNF mRNA expression were seen in diabetic extensor
digitorum longus (EDL) muscle. Using a nonradioactive in situ hybridization
technique for electron microscopy, the elevated expression of BDNF mRNA in the
diabetic soleus muscle was localized within muscle fibers as well as activated
satellite cells. This study shows that diabetic soleus muscle, in contrast to
diabetic EDL and to soleus and EDL muscle of normal animals, is highly
susceptible to contraction-induced damage. Intense contraction and the associated
muscle fiber damage in the diabetic soleus muscle result in an upregulation of
BDNF mRNA in muscle fibers and activated satellite cells, which may be involved
in the restoration and/or maintenance of nerve/muscle integrity.
PMID- 10686080
TI - Nicotine attenuates arachidonic acid-induced overexpression of nitric oxide
synthase in cultured spinal cord neurons.
AB - Primary spinal cord trauma can initiate a cascade of pathophysiologic events
which markedly contribute to the expansion and amplification of the primary
insult. The detailed mechanisms of these secondary neurochemical reactions are
largely unknown; however, they involve membrane lipid derangements with the
release of free fatty acids, in particular, arachidonic acid (AA). AA can induce
several injury effects on spinal cord neurons. We hypothesize that upregulation
of nitric oxide synthase (NOS) is among the most important mechanisms of
arachidonic-acid-induced neuronal dysfunction and that nicotine can attenuate
this effect. To study these hypotheses, spinal cord neurons were exposed to AA
and/or nicotine, and several markers of neuronal nitric oxide synthase (nNOS)
metabolism were measured. In addition, cotreatments with either inhibitors of
nicotinic receptors or inhibitors of specific NOS isoforms were employed.
Treatment with AA markedly increased activity of nNOS, as well as mRNA and
protein levels of this enzyme. Changes in nNOS expression were accompanied by an
increase in cellular cGMP and medium nitrite levels. Pretreatment with nicotine
decreased AA-induced overexpression of nNOS and elevation of nitrite levels. In
addition, it appeared that these nicotine effects could be partially modulated
both by the alpha7 nicotinic receptors or by nonreceptor mechanisms.
Alternatively, the observed changes could also be mediated by an alternate
nicotinic receptor mechanism which is not blocked by alpha-bungarotoxin or
mecamylamine. Results of the present study indicate that exposure to AA can lead
to induction of nNOS in cultured spinal cord neurons. In addition, nicotine can
exert a neuroprotective effect by attenuation of AA-induced upregulation of nNOS
metabolism. These data may have therapeutic implications for the treatment of
acute spinal cord trauma.
PMID- 10686081
TI - Oxidized high-density lipoprotein induces neuron death.
AB - High-density lipoprotein (HDL) exists within the brain and is highly vulnerable
to oxidative modifications. The focus of the present study was to determine the
effect of HDL and oxidized HDL (oxHDL) upon neurons, astrocytes, and microglia.
Administration of highly oxidized HDL, but not native, minimally, or moderately
modified HDL resulted in a dose- and time-dependent increase in oxidative stress
and death of cultured rat embryonic neurons. Astrocyte and microglia cultures
treated with highly oxidized HDL displayed increased reactive oxygen species
formation but no toxicity. Application of oxHDL exacerbated oxidative stress and
neuron death induced by beta-amyloid peptide. Studies using pharmacological
inhibitors implicate the involvement of calcium and reactive oxygen species in
oxHDL-induced neuronal loss. Neural cells expressing increased levels of BCL-2
had decreased levels of oxidative stress and neuron death following exposure to
oxHDL. Together, these data demonstrate that oxHDL increases oxidative stress in
neurons, astrocytes, and microglia which ultimately culminate in neuron death.
PMID- 10686082
TI - Continuous infusion of cyclosporin A postinjury significantly ameliorates
cortical damage following traumatic brain injury.
AB - Traumatic brain injury (TBI) results in the rapid necrosis of cortical tissue at
the site of injury. In the ensuing hours and days, secondary injury exacerbates
the original damage resulting in significant neurological dysfunction. Recent
reports from our lab demonstrate that a bolus injection of the immunosuppressant
cyclosporin A (CsA) is neuroprotective following TBI. CsA transiently inhibits
the opening of the mitochondrial permeability transition pore and maintains
calcium homeostasis in isolated mitochondria. The present study utilized a
unilateral controlled cortical impact model of TBI to assess whether the
neuroprotective effects of CsA could be extended by chronic infusion. Adult rats
were subjected to a moderate (2 mm) cortical deformation and the extent of
cortical damage was assessed using modern stereological techniques. Animals were
administrated a 20 mg/kg intraperitoneal bolus of CsA or vehicle 15 min
postinjury and osmotic minipumps were implanted subcutaneously to deliver CsA
(4.5 or 10 mg/kg/day) or vehicle. All animals receiving CsA demonstrated a
significant reduction in lesion volume, with the highest dose offering the most
neuroprotection (74% reduction in lesion volume). These results extend our
previous findings and demonstrate that chronic infusion of CsA is neuroprotective
following TBI. These findings also suggest that the mechanisms responsible for
tissue necrosis following TBI are amenable to manipulation.
PMID- 10686083
TI - NMDA receptors modulate dopamine loss due to energy impairment in the substantia
nigra but not striatum.
AB - Defects in energy metabolism have been detected in patients with Parkinson's
disease and have been proposed as a contributing factor in the disease. Previous
in vitro studies showed that NMDA receptors contribute to the loss of dopamine
neurons caused by the metabolic inhibitor malonate. In vivo, it is not known
whether this interaction occurs through a postsynaptic action on the cell body in
the substantia nigra or through a presynaptic action at the dopamine terminal in
the striatum. So we could discern the anatomical level of NMDA receptor
involvement, rats were infused with malonate, either into the left striatum or
into the left substantia nigra. NMDA receptors were locally blocked by an
intranigral or intrastriatal coinfusion of malonate plus MK-801 followed by a
second infusion of MK-801 3 h later. Animals were examined at 1 week for striatal
and nigral dopamine and GABA levels. Intranigral infusion of malonate (0.5
micromol) produced an approximate 50% loss of both nigral dopamine and GABA. MK
801 (0.1 micromol) provided significant protection against both nigral dopamine
and GABA loss and against anterograde damage to dopamine terminals in the
striatum. Intrastriatal administration of malonate (2 micromol) produced a 68 and
35% loss of striatal dopamine and GABA, respectively. In contrast to intranigral
administration, intrastriatal blockade of NMDA receptors did not protect against
striatal dopamine loss, although GABA loss was significantly attenuated. Core
body temperature monitored several hours throughout the experiment was unchanged.
Consistent with a lack of effect of NMDA antagonists on malonate-induced toxicity
to dopamine neurons in striatum, intrastriatal infusion of NMDA had a pronounced
effect on long-term GABA toxicity with little effect of dopamine loss. These
findings are consistent with a postsynaptic action of NMDA receptors on mediating
toxicity to dopamine neurons during impaired energy metabolism.
PMID- 10686084
TI - Loss of cholinergic phenotype in basal forebrain coincides with cognitive decline
in a mouse model of Down's syndrome.
AB - Mice with segmental trisomy of chromosome 16 (Ts65Dn) have been used as a model
for Down's syndrome. These mice are born with a normal density of basal forebrain
cholinergic neurons but, like patients with Down's syndrome, undergo a
significant deterioration of these neurons later in life. The time course for
this degeneration of cholinergic neurons has not been studied, nor is it known if
it correlates with the progressive memory and learning deficits described. Ts65Dn
mice that were 4, 6, 8, and 10 months old were sacrificed for evaluation of basal
forebrain morphology. Separate groups of mice were tested on visual or spatial
discrimination learning and reversal. We found no alterations in cholinergic
markers in 4-month-old Ts65Dn mice, but thereafter a progressive decline in
density of cholinergic neurons, as well as significant shrinkage of cell body
size, was seen. A parallel loss of staining for the high-affinity nerve growth
factor receptor, trkA, was observed at all time points, suggesting a biological
mechanism for the cell loss involving this growth factor. Other than transient
difficulty in learning the task requirements, there was no impairment of trisomic
mice on visual discrimination learning and reversal, whereas spatial learning and
reversal showed significant deficits, particularly in the mice over 6 months of
age. Thus, the loss of ChAT-immunoreactive neurons in the basal forebrain was
coupled with simultaneous deficits in behavioral flexibility on a spatial task
occurring for the first time around 6 months of age. These findings suggest that
the loss of cholinergic function and the simultaneous decrease in trkA
immunoreactivity in basal forebrain may directly correlate with cognitive
impairment in the Ts65Dn mouse
PMID- 10686086
TI - Growth factors in combination, but not individually, rescue rd mouse
photoreceptors in organ culture.
AB - The rd mouse retina is an animal model for human retinal dystrophy in which the
rod photoreceptors undergo apoptosis during the first 4 weeks in vivo or in organ
culture. We have examined the effect of different families of trophic factors on
the survival of rd mouse photoreceptors in organ culture. Retinas were harvested
from rd mice at postnatal day 2 and grown in organ culture for 27 days in vitro
(DIV) in DMEM with 10% fetal calf serum. Ciliary neurotrophic factor (CNTF),
brain-derived neurotrophic factor (BDNF), fibroblast growth factor-2 (FGF2),
glial cell line-derived neurotrophic factor (GDNF), neurturin, and persephon were
added individually or in combination to the medium at a dose of 50 ng/ml or less.
CNTF + BDNF in combination resulted in photoreceptor survival comparable to wild
type retinas after 27 DIV. CNTF + FGF2 or CNTF + GDNF produced a partial
prevention of photoreceptor death. Photoreceptor degeneration was not blocked by
any of the trophic factors added individually. A significant increase in
photoreceptor survival was seen with forskolin added to CNTF, but not to BDNF,
FGF2, or GDNF. These results demonstrate that trophic factors promote
photoreceptor survival through a synergistic interaction. Increased understanding
of receptor interactions and signaling pathways may lead to a potential
therapeutic role for combinatorial trophic factors in treatment of photoreceptor
dystrophies.
PMID- 10686085
TI - TGFbeta trophic factors differentially modulate motor axon outgrowth and
protection from excitotoxicity.
AB - Transforming growth factor (TGF) beta-like trophic factors have been shown to be
protective in acute neuronal injury paradigms. In the current study, we analyzed
and compared members of this growing family, including glial cell line-derived
neurotrophic factor (GDNF), neurturin, nodal, persephin, and TGFbeta1, for
protection against chronic glutamate toxicity. In parallel, we developed a
organotypic spinal cord culture system to study the ability of these factors to
promote motor axon outgrowth across white matter. Using these systems, we were
able to differentiate the neuroprotective effect of the TGFbeta-like factors from
their motor axon outgrowth-promoting activity. GDNF, neurturin, persephin, nodal,
and TGFbeta1 all protected against excitotoxic motor neuron degeneration. Low
amounts of GDNF (1 ng/ml) and high concentrations of neurturin induced vigorous
motor axon outgrowth. In contrast, nodal, persephin, and TGFbeta1 did not induce
motor axon outgrowth. Both GDNF and neurturin bind to Ret receptor complexes and
were capable of activating the MAP kinase pathway. A specific inhibitor of MAP
kinase kinase, PD98059, inhibited the motor axon outgrowth-promoting activity of
the GDNF but not the neuroprotective activity. Similarly, the specific PI3K
inhibitors, LY294002 and wortmannin, were able to inhibit the promotion of motor
axon outgrowth by GDNF, but did not affect neuroprotective activity. Our results
suggest that the neurite outgrowth-promoting effect of GDNF is mediated through
the PI3K and MAP kinase pathways. The neuroprotective effect of GDNF appears to
be through a separate pathway.
PMID- 10686087
TI - Differential vulnerability of hippocampus, basal ganglia, and prefrontal cortex
to long-term NMDA excitotoxicity.
AB - In human brain, nonartherosclerotic calcification is associated with normal aging
and several pathological conditions without any clear significance. In all
situations, calcification appears predominantly in the basal ganglia, but is also
frequent in the hippocampus and cerebral cortex. alpha-Amino-(3-hydroxi-5-methyl
4-isoxazol-4-il)-propionic acid-induced lesion of the globus pallidus is
associated in rats with the formation of calcium deposits similar to those
observed in the human brain. To determine whether direct neuronal activation may
induce calcification, N-methyl-d-aspartate (NMDA) was microinjected in rat
hippocampus, globus pallidus, and lateral prefrontal cortex. Two months later,
neuronal death was associated with calcium deposits that were characterized in
terms of distribution and size. A unique population of deposits was present in
the hippocampus and prefrontal cortex, whereas in the globus pallidus two main
groups could be differentiated. Calcification was always associated with a
significant microglial reaction as shown by the peripheral benzodiazepine
receptor autoradiography. Monoamine oxidase B autoradiography, reflecting the
astroglial reaction, was also significantly increased. Our results provide
evidence that acute NMDA neuronal activation leads with time to calcification
associated with a glial reaction and indicate that nonartherosclerotic
calcification in the human brain may develop from an acute NMDA receptor
activation. A key role of the metabotropic mGluR1 receptor is also suggested.
PMID- 10686088
TI - The MCT ketogenic diet: effects on animal seizure models.
AB - Male Wistar rat pups were weaned at 20 days of age and placed on either a control
diet or a ketogenic diet containing medium-chain triglyceride (MCT) oil. After 10
days on the diets, they were subjected to one of four seizure tests-maximal
electric shock, threshold electroconvulsive shock, threshold pentylenetetrazol,
or maximal pentylenetetrazol. After testing, subjects were sacrificed and blood
samples were analyzed for beta-hydroxybutyrate concentration. It was found that
the MCT diet produced blood levels of beta-hydroxybutyrate that were comparable
to or higher than those commonly reported in clinical studies. However, no
anticonvulsant effects were seen in any of the seizure tests. In fact, the tests
involving maximal seizures actually showed proconvulsant effects. It appears that
clinical levels of ketones may be present in the bloodstream without suppressing
seizures.
PMID- 10686089
TI - Chronic moderate hyperammonemia impairs active and passive avoidance behavior and
conditional discrimination learning in rats.
AB - The cerebral dysfunction associated with hepatic encephalopathy is generally
considered to have hyperammonemia as one of its main causes. Hyperammonemia
impairs the neuronal glutamate-nitric oxide-cyclic GMP pathway and the induction
of NMDA receptor-dependent long-term potentiation in the hippocampus. We studied
the performance of pre/neonatally and postnatally exposed rats to hyperammonemia
on active avoidance, passive avoidance, and conditional discrimination tasks.
Pre/neonatal hyperammonemia slowed learning of active avoidance behaviors and
impaired memory for the passive avoidance task while postnatal hyperammonemia
impaired learning on the conditional discrimination task. Hyperammonemia thus may
produce cognitive disturbances that relate to the effects of ammonia on the
neuronal glutamate-nitric oxide-cyclic GMP pathway.
PMID- 10686090
TI - Selective susceptibility to inhibitors of GABA synthesis and antagonists of
GABA(A) receptor in rats with genetic absence epilepsy.
AB - Thalamocortical spike-and-wave discharges characterize the nonconvulsive absence
seizures that occur spontaneously in genetic absence epilepsy rats from
Strasbourg (GAERS), a selected strain of Wistar rats. GABA is crucial in the
generation of absence seizures. The susceptibility to convulsions induced by
threshold doses of various GABA receptor antagonists and inhibitors of GABA
synthesis, kainic acid and strychnine, was compared in GAERS and in nonepileptic
rats from a selected control strain (NE). The brain structures involved in the
drug-elicited convulsive seizures were mapped by c-Fos immunohistochemistry.
Injection of various antagonists of the GABA(A) receptor, bicuculline and
picrotoxin, and inverse agonists of the benzodiazepine site (FG 7142 and DMCM)
induced myoclonic spike-and-wave discharges followed by clonic or tonic-clonic
seizures with high paroxysmal activity on the cortical EEG. The incidence of the
convulsions was dose-dependent and was higher in GAERS than in NE rats. Mapping
of c-Fos expression showed that the frontoparietal cortex was constantly involved
in the convulsive seizures elicited by a threshold convulsant dose, whereas
limbic participation was variable. In contrast, GAERS were less susceptible than
NE rats to the tonic-clonic convulsions induced by the inhibitors of glutamate
decarboxylase, isoniazide and 3-mercaptopropionic acid. The GABA(B) receptor
antagonist CGP 56999 and kainic acid induced a similar incidence of seizures in
GAERS and NE rats and predominantly activated the hippocampus. No difference in
the tonic seizures elicited by strychnine could be evidenced between the strains.
These results suggest that an abnormal cortical GABAergic activity may underlie
absence seizures in GAERS.
PMID- 10686091
TI - Effects of pertussis toxin and galpha-protein-specific antibodies on
phosphoinositide hydrolysis in rat brain membranes after cholinergic denervation
and hippocampal sympathetic ingrowth.
AB - Cholinergic denervation of the hippocampal formation, via medial septal lesions,
induces peripheral noradrenergic fibers, originating from the superior cervical
ganglion, to grow into the hippocampus. We have previously reported that
cholinergic denervation and hippocampal sympathetic ingrowth differentially
affect guanosine-5'-O-(3-thiotriphosphate)- as well as guanosine-5'-O-(3
thiotriphosphate) + carbachol-stimulated polyphosphoinositide hydrolysis,
suggesting an alteration in G proteins and/or the entire receptor complex. To
examine the type of G protein which may be involved in these effects, rat dorsal
hippocampal membranes were preincubated with pertussis toxin in the presence of
guanosine-5'-O-(3-thiotriphosphate) and guanosine-5'-O-(3-thiotriphosphate) +
carbachol. Pertussis toxin reduced guanosine-5'-O-(3-thiotriphosphate) in all
groups, while guanosine-5'-O-(3-thiotriphosphate) + carbachol-stimulated
phosphoinositide hydrolysis was reduced in controls and animals without
sympathetic ingrowth but not in animals with hippocampal sympathetic ingrowth.
This suggests that pertussis toxin-sensitive G proteins may be involved in the
mediation of phosphoinositide hydrolysis. To confirm this hypothesis, membranes
were preincubated with antibodies to Galphao and Gq/11. The Go antibody
significantly decreased guanosine-5'-O-(3-thiotriphosphate) in all groups, while
guanosine-5'-O-(3-thiotriphosphate) +carbachol-stimulated phosphoinositide
hydrolysis was reduced only in hippocampal sympathetic ingrowth. Impairment of
guanosine-5'-O-(3-thiotriphosphate) and carbachol-stimulated phosphoinositide
hydrolysis was also decreased in all groups when preincubated with Gq/11
antibody. To determine whether hippocampal sympathetic ingrowth or cholinergic
denervation altered the concentration of various G proteins, immunoblotting
methodology was utilized. Gq/11 concentrations were found to be equivalent among
groups. The density of Go1, Go2, and Go3 isoforms was significantly increased in
the cholinergic denervation, while in the hippocampal sympathetic ingrowth only
group Go3 was significantly increased. When assessed as total Go protein, density
was increased significantly only in the cholinergic denervation group. Overall,
these results suggest that hippocampal sympathetic ingrowth and cholinergic
denervation induce alterations in phosphoinositide hydrolysis through both the
Gq/11 and the Go proteins and that the coupling between muscarinic receptor and G
protein is the possible site which affects changes in phosphoinositide turnover.
Our results also suggest that cholinergic denervation and hippocampal sympathetic
ingrowth may mediate phosphoinositide hydrolysis through an effect on different
isoforms of the same G protein.
PMID- 10686092
TI - Evaluating the efficacy of citicoline in embolic ischemic stroke in rats:
neuroprotective effects when used alone or in combination with urokinase.
AB - The combination of thrombolysis with neuroprotection, because of different
mechanisms, would be expected to show better results when used after onset of
focal ischemia. In this study we report our experience with the neuronal
protective effects of citicoline alone and in combination with urokinase in a
model of focal ischemia. Both medications were injected 2 h after onset of a
focal occlusion of the middle cerebral artery (MCA) in rats. Focal ischemia was
produced with embolization of a clot into the origin of the MCA. This produces a
large infarction involving the cortex and the basal ganglia. Animals were
observed for neuronal deficts at 2 and 24 h after surgery and were sacrificed 72
h after onset of ischemia. Saline-treated animals showed a large infarction
involving the cerebral cortex and basal ganglion in most animals (volume 33.1 +/-
9.7%). Animals treated with citicoline alone were divided in two groups. The
first group of animals were treated with a single injection (300 mg/kg, ip) of
the medication 2 h after the arterial occlusion. The second group was treated
with the active medication intermittently (3 x 300 mg/kg, ip) over a 72-h period.
There was a significant decrease in the neuronal damage in the cortex in the
animals treated with citicoline (single dose, 20.9 +/- 9.7%, P = 0.01;
intermittent injection, 18.9 +/- 11.4%, P < 0.008). The last experiment evaluated
the usefulness of the combination of citicoline with intraarterial urokinase. The
combination showed significantly more protection than with urokinase or
citicoline alone (volume 13.6 +/- 9.1%, P < 0.001). We conclude from our
experiments that citicoline may offer significant neuronal protection that may be
further enhanced with the addition of a thrombolytic agent.
PMID- 10686093
TI - Cold exposure enhances tactile allodynia transiently in mononeuropathic rats.
AB - A laser and erythrosin-B-induced sciatic nerve injury decreases thresholds of a
mechanically induced paw withdrawal reflex and enhances cold-induced withdrawal
behavior of the affected limb. Exposure of the affected paw to a normally
innocuous cold stimulus results in a transient decrease in the threshold of the
mechanically evoked paw withdrawal reflex in neuropathic but not in intact rats.
The present data suggest that in an experimental neuropathic state a normally
innocuous cold stimulus may further sensitize spinally mediated withdrawal
reflexes to stimuli of another stimulus modality, in this case, to innocuous
tactile stimuli. Therefore, testing mechanical allodynia in neuropathic rats
immediately after testing cold allodynia may produce artifactual results.
PMID- 10686094
TI - Cryo-trapping the six-coordinate, distorted-octahedral active site of manganese
superoxide dismutase.
AB - Superoxide dismutase protects organisms from potentially damaging oxygen radicals
by catalyzing the disproportionation of superoxide to oxygen and hydrogen
peroxide. We report the use of cryogenic temperatures to kinetically capture the
sixth ligand bound to the active site of manganese superoxide dismutase (MnSOD).
Synchrotron X-ray diffraction data was collected from Escherichia coli MnSOD
crystals grown at pH 8.5 and cryocooled to 100 K. Structural refinement to 1.55 A
resolution and close inspection of the active site revealed electron density for
a sixth ligand that was interpreted to be a hydroxide ligand. The six-coordinate,
distorted-octahedral geometry assumed during inhibition by hydroxide is compared
to the room temperature, five-coordinate, trigonal bipyramidal active site
determined with crystals grown from practically identical conditions. The gateway
residues Tyr34, His30 and a tightly bound water molecule are implicated in
closing-off the active site and blocking the escape route of the sixth ligand.
PMID- 10686095
TI - Nature disfavors sequences of alternating polar and non-polar amino acids:
implications for amyloidogenesis.
AB - Recent experiments with combinatorial libraries of de novo proteins have
demonstrated that sequences designed to contain polar and non-polar amino acid
residues arranged in an alternating pattern form fibrillar structures resembling
beta-amyloid. This finding prompted us to probe the distribution of alternating
patterns in the sequences of natural proteins. Analysis of a database of 250,514
protein sequences (79,708,024 residues) for all possible binary patterns of polar
and non-polar amino acid residues revealed that alternating patterns occur
significantly less often than other patterns with similar compositions. The under
representation of alternating binary patterns in natural protein sequences,
coupled with the observation that such patterns promote amyloid-like structures
in de novo proteins, suggests that sequences of alternating polar and non-polar
amino acids are inherently amyloidogenic and consequently have been disfavored by
evolutionary selection.
PMID- 10686096
TI - Antirestriction protein Ard (Type C) encoded by IncW plasmid pSa has a high
similarity to the "protein transport" domain of TraC1 primase of promiscuous
plasmid RP4.
AB - The IncW plasmid pSa contains the gene ard encoding an antirestriction function
that is specific for type I restriction and modification systems. The nucleotide
sequence of ard was determined and an appropriate polypeptide of about 33 kDa was
identified in Escherichia coli T7 expression system. Analysis of deduced amino
acid sequence of Ard encoded by pSa revealed that this protein has no significant
similarities with the known Ard proteins (ArdA and ArdB types) except the
"antirestriction" motif (14 amino acid residues in length) conserved for all
known Ard proteins. This finding suggests that pSa Ard may be classified as a new
type of Ard proteins which we designated ArdC. The remarkable feature of ArdC is
that it has a high degree of similarity (about 38 % identity) to the N-terminal
region of RP4 TraC1 primase which includes about 300 amino acid residues and
seems to be essential for binding to the single-stranded DNA and TraC1 protein
transport to the recipient cells during the conjugal transfer of plasmid DNA.
ArdC also binds to single-stranded DNA. In addition, this protein is able in
vitro to protect the single-stranded but not double-stranded plasmid DNA against
the activity of type II restriction endonuclease HhaI that cleaves both single
and double-stranded DNA. We suggest that like TraC1, ArdC would be transported as
a result of their interaction with the single-stranded DNA of transferred plasmid
strand during conjugative passage through the cell envelope to the recipient
bacterium. Such properties of ArdC protein might be useful to protect immediately
the incoming single-stranded DNA from the host endonucleases.
PMID- 10686097
TI - Sequence and position-dependence of the equilibrium accessibility of nucleosomal
DNA target sites.
AB - We have previously shown that nucleosomes are conformationally dynamic: DNA
sequences that in the time-average are buried inside nucleosomes are nevertheless
transiently accessible, even to large proteins (or any other macromolecule). We
refer to this dynamic behavior as "site exposure". Here we show that: (i) the
equilibrium constants describing this dynamic site exposure decrease
progressively from either end of the nucleosomal DNA in toward the middle; and
(ii) these position-dependent equilibrium constants are strongly dependent on the
nucleosomal DNA sequence. The progressive decrease in equilibrium constant with
distance inside the nucleosome supports the hypothesis that access to sites
internal to a nucleosome is provided by progressive (transient) release of DNA
from the octamer surface, starting from one end of the nucleosomal DNA. The
dependence on genomic DNA sequence implies that a specific genomic DNA sequence
could be a major determinant of target site occupancies achieved by regulatory
proteins in vivo, by either governing the time-averaged accessibility for a given
nucleosome position, or biasing the time-averaged positioning (of mobile
nucleosomes), which in turn is a major determinant of site accessibility.
PMID- 10686098
TI - Structural and functional comparative study of the complexes formed by viral o29,
Nf and GA-1 SSB proteins with DNA.
AB - Single-stranded DNA-binding proteins have in common their crucial roles in DNA
metabolism, although they exhibit significant differences in their single
stranded DNA binding properties. To evaluate the correlation between the
structure of different nucleoprotein complexes and their function, we have
carried out a comparative study of the complexes that the single-stranded DNA
binding proteins of three related bacteriophages, o29, Nf and GA-1, form with
single-stranded DNA. Under the experimental conditions used, o29 and Nf single
stranded DNA-binding proteins are stable monomers in solution, while GA-1 single
stranded DNA-binding protein presents a hexameric state, as determined in
glycerol gradients. The thermodynamic parameters derived from quenching
measurements of the intrinsic protein fluorescence upon single-stranded DNA
binding revealed (i) that GA-1 single-stranded DNA-binding protein occludes a
larger binding site (n=51 nt/oligomer) than o29 and Nf SSBs (n=3.4 and 4.7
nt/monomer, respectively); and (ii) that it shows a higher global affinity for
single-stranded DNA (GA-1 SSB, K(eff)=18.6 x 10(5) M(-1); o29 SSB, K(eff)=2.2 x
10(5) M(-1); Nf SSB, K(eff)=2.9 x 10(5) M(-1)). Altogether, these parameters
justify the differences displayed by the GA-1 single-stranded DNA-binding protein
and single-stranded DNA complex under the electron microscope, and the
requirement of higher amounts of o29 and Nf single-stranded DNA-binding proteins
than of GA-1 SSB in gel mobility shift assays to produce a similar effect. The
structural differences of the nucleoprotein complexes formed by the three single
stranded DNA-binding proteins with single-stranded DNA correlate with their
different functional stimulatory effects in o29 DNA amplification.
PMID- 10686099
TI - Crystal structures of mutant monomeric hexokinase I reveal multiple ADP binding
sites and conformational changes relevant to allosteric regulation.
AB - Hexokinase I, the pacemaker of glycolysis in brain tissue, is composed of two
structurally similar halves connected by an alpha-helix. The enzyme dimerizes at
elevated protein concentrations in solution and in crystal structures; however,
almost all published data reflect the properties of a hexokinase I monomer in
solution. Crystal structures of mutant forms of recombinant human hexokinase I,
presented here, reveal the enzyme monomer for the first time. The mutant
hexokinases bind both glucose 6-phosphate and glucose with high affinity to their
N and C-terminal halves, and ADP, also with high affinity, to a site near the N
terminus of the polypeptide chain. Exposure of the monomer crystals to ADP in the
complete absence of glucose 6-phosphate reveals a second binding site for adenine
nucleotides at the putative active site (C-half), with conformational changes
extending 15 A to the contact interface between the N and C-halves. The
structures reveal distinct conformational states for the C-half and a rigid-body
rotation of the N-half, as possible elements of a structure-based mechanism for
allosteric regulation of catalysis.
PMID- 10686100
TI - Stability of a structural scaffold upon activity transfer: X-ray structure of a
three fingers chimeric protein.
AB - Fasciculin 2 and toxin alpha proteins belong to the same structural family of
three-fingered snake toxins. They act on different targets, but in each case the
binding region involves residues from loops I and II. The superimposition of the
two structures suggests that these functional regions correspond to structurally
distinct zones. Loop I, half of loop II and the C-terminal residue of fasciculin
2 were therefore transferred into the toxin alpha. The inhibition constant of the
resulting chimera is only 15-fold lower than that of fasciculin 2, and as
expected the potency of binding to the toxin alpha target has been lost. In order
to understand the structure-function relationship between the chimera and its
"parent" molecules, we solved its structure by X-ray crystallography. The protein
crystallized in space group P3(1)21 with a=b=58.5 A, and c=62.3 A. The crystal
structure was solved by molecular replacement and refined to 2.1 A resolution.
The structure belongs to the three-fingered snake toxin family with a core of
four disulphide bridges from which emerge the three loops I, II and III.
Superimposition of the chimera on fasciculin 2 or toxin alpha revealed an overall
fold intermediate between those of the two parent molecules. The regions
corresponding to toxin alpha and to fasciculin 2 retained their respective
geometries. In addition, the chimera protein displayed a structural behaviour
similar to that of fasciculin 2, i.e. dimerization in the crystal structure of
fasciculin 2, and the geometry of the region that binds to acetylcholinesterase.
In conclusion, this structure shows that the chimera retains the general
structural characteristics of three-fingered toxins, and the structural
specificity of the transferred function.
PMID- 10686101
TI - Rational design of cyclodextrin glycosyltransferase from Bacillus circulans
strain 251 to increase alpha-cyclodextrin production.
AB - Cyclodextrin glycosyltransferases (CGTase) (EC 2.4.1.19) are extracellular
bacterial enzymes that generate cyclodextrins from starch. All known CGTases
produce mixtures of alpha, beta, and gamma-cyclodextrins. A maltononaose
inhibitor bound to the active site of the CGTase from Bacillus circulans strain
251 revealed sugar binding subsites, distant from the catalytic residues, which
have been proposed to be involved in the cyclodextrin size specificity of these
enzymes. To probe the importance of these distant substrate binding subsites for
the alpha, beta, and gamma-cyclodextrin product ratios of the various CGTases, we
have constructed three single and one double mutant, Y89G, Y89D, S146P and
Y89D/S146P, using site-directed mutagenesis. The mutations affected the
cyclization, coupling; disproportionation and hydrolyzing reactions of the
enzyme. The double mutant Y89D/S146P showed a twofold increase in the production
of alpha-cyclodextrin from starch. This mutant protein was crystallized and its X
ray structure, in a complex with a maltohexaose inhibitor, was determined at 2.4
A resolution. The bound maltohexaose molecule displayed a binding different from
the maltononaose inhibitor, allowing rationalization of the observed change in
product specificity. Hydrogen bonds (S146) and hydrophobic contacts (Y89) appear
to contribute strongly to the size of cyclodextrin products formed and thus to
CGTase product specificity. Changes in sugar binding subsites -3 and -7 thus
result in mutant proteins with changed cyclodextrin production specificity.
PMID- 10686102
TI - Is folding of beta-lactoglobulin non-hierarchic? Intermediate with native-like
beta-sheet and non-native alpha-helix.
AB - The refolding of beta-lactoglobulin, a beta-barrel protein consisting of beta
strands betaA-betaI and one major helix, is unusual because non-native alpha
helices are formed at the beginning of the process. We studied the refolding
kinetics of bovine beta-lactoglobulin A at pH 3 using the stopped-flow circular
dichroism and manual H/(2)H exchange pulse labeling coupled with heteronuclear
NMR. The protection pattern from the H/(2)H exchange of the native state
indicated the presence of a stable hydrophobic core consisting of betaF, betaG
and betaH strands. The protection pattern of the kinetic intermediate obtained
about one second after initiating the reaction was compared with that of the
native state. In this relatively late kinetic intermediate, which still contains
some non-native helical structure, the disulfide-bonded beta-hairpin made up of
betaG and betaH strands was formed, but the rest of the molecule was fluctuating,
where the non-native alpha-helices may reside. Subsequently, the core beta-sheet
extends, accompanied by a further alpha-helix to beta-sheet transition. Thus, the
refolding of beta-lactoglobulin exhibits two elements: the critical role of the
core beta-sheet is consistent with the hierarchic mechanism, whereas the alpha
helix to beta-sheet transition suggests the non-hierarchic mechanism.
PMID- 10686103
TI - Thermodynamics of DNA binding and condensation: isothermal titration calorimetry
and electrostatic mechanism.
AB - The thermodynamics of binding of the trivalent cations cobalt hexammine and
spermidine to plasmid DNA was studied by isothermal titration calorimetry. Two
stages were observed in the course of titration, the first attributed to cation
binding and the second to DNA condensation. A standard calorimetric data analysis
was extended by applying an electrostatic binding model, which accounted for most
of the observed data. Both the binding and condensation reactions were
entropically driven (TDeltaS approximately +10 kcal/mol cation) and enthalpically
opposed (DeltaH approximately +1 kcal/mol cation). As predicted from their
relative sizes, the binding constants of the cations were indistinguishable, but
cobalt hexammine had a much greater DNA condensing capacity because it is more
compact than spermidine. The dependence of both the free energy of cobalt
hexammine binding and the critical cobalt hexammine concentration for DNA
condensation on temperature and monovalent cation concentration followed the
electrostatic model quite precisely. The heat capacity changes of both stages
were positive, perhaps reflecting both the temperature dependence of the
dielectric constant of water and the burial of polar surfaces. DNA condensation
occurred when about 67 % of the DNA phosphate charge was neutralized by cobalt
hexammine and 87 % by spermidine. During condensation, the remaining DNA charge
was neutralized.
PMID- 10686104
TI - Backbone dynamics of a cbEGF domain pair in the presence of calcium.
AB - Calcium binding (cb) epidermal growth factor-like (EGF) domains are found in a
wide variety of extracellular proteins with diverse functions. In several
proteins, including the fibrillins (1 and 2), the low-density lipoprotein
receptor, the Notch receptor and related molecules, these domains are organised
as multiple tandem repeats. The functional importance of calcium-binding by EGF
domains has been underscored by the identification of missense mutations
associated with defective calcium-binding, which have been linked to human
diseases. Here, we present (15)N backbone relaxation data for a pair of cbEGF
domains from fibrillin-1, the defective protein in the Marfan syndrome. The data
were best fit using a symmetric top model, confirming the extended conformation
of the cbEGF domain pair. Our data demonstrate that calcium plays a key role in
stabilising the rigidity of the domain pair on the pico- to millisecond time
scale. Strikingly, the most dynamically stable region of the construct is centred
about the domain interface. These results provide important insight into the
properties of intact fibrillin-1, the consequences of Marfan syndrome causing
mutations, and the ultrastructure of fibrillins and other extracellular matrix
proteins.
PMID- 10686105
TI - The structural basis for enhanced stability and reduced DNA binding seen in
engineered second-generation Cro monomers and dimers.
AB - It was previously shown that the Cro repressor from phage lambda, which is a
dimer, can be converted into a stable monomer by a five-amino acid insertion.
Phe58 is the key residue involved in this transition, switching from interactions
which stabilize the dimer to those which stabilize the monomer. Structural
studies, however, suggested that Phe58 did not penetrate into the core of the
monomer as well as it did into the native dimer. This was strongly supported by
the finding that certain core-repacking mutations, including in particular, Phe58
->Trp, increased the stability of the monomer. Unexpectedly, the same
substitution also increased the stability of the native dimer. At the same time
it decreased the affinity of the dimer for operator DNA. Here we describe the
crystal structures of the Cro F58W mutant, both as the monomer and as the dimer.
The F58W monomer crystallized in a form different from that of the original
monomer. In contrast to that structure, which resembled the DNA-bound form of
Cro, the F58W monomer is closer in structure to wild-type (i.e. non-bound) Cro.
The F58W dimer also crystallizes in a form different from the native dimer but
has a remarkably similar overall structure which tends to confirm the large
changes in conformation of Cro on binding DNA. Introduction of Trp58 perturbs the
position occupied by the side-chain of Arg38, a DNA-contact residue, providing a
structural explanation for the reduction in DNA-binding affinity. The improved
thermal stability is seen to be due to the enhanced solvent transfer free energy
of Trp58 relative to Phe58, supplemented in the dimer structure, although not the
monomer, by a reduction in volume of internal cavities.
PMID- 10686106
TI - Molecular dynamics simulations of a beta-hairpin fragment of protein G: balance
between side-chain and backbone forces.
AB - How is the native structure encoded in the amino acid sequence? For the
traditional backbone centric view, the dominant forces are hydrogen bonds
(backbone) and phi-psi propensity. The role of hydrophobicity is non-specific.
For the side-chain centric view, the dominant force of protein folding is
hydrophobicity. In order to understand the balance between backbone and side
chain forces, we have studied the contributions of three components of a beta
hairpin peptide: turn, backbone hydrogen bonding and side-chain interactions, of
a 16-residue fragment of protein G. The peptide folds rapidly and cooperatively
to a conformation with a defined secondary structure and a packed hydrophobic
cluster of aromatic side-chains. Our strategy is to observe the structural
stability of the beta-hairpin under systematic perturbations of the turn region,
backbone hydrogen bonds and the hydrophobic core formed by the side-chains,
respectively. In our molecular dynamics simulations, the peptides are solvated.
with explicit water molecules, and an all-atom force field (CFF91) is used.
Starting from the original peptide (G41EWTYDDATKTFTVTE56), we carried out the
following MD simulations. (1) unfolding at 350 K; (2) forcing the distance
between the C(alpha) atoms of ASP47 and LYS50 to be 8 A; (3) deleting two turn
residues (Ala48 and Thr49) to form a beta-sheet complex of two short peptides,
GEWTYDD and KTFTVTE; (4) four hydrophobic residues (W43, Y45, F52 and T53) are
replaced by a glycine residue step-by-step; and (5) most importantly, four amide
hydrogen atoms (T44, D46, T53, and T55, which are crucial for backbone hydrogen
bonding), are substituted by fluorine atoms. The fluorination not only makes it
impossible to form attractive hydrogen bonding between the two beta-hairpin
strands, but also introduces a repulsive force between the two strands due to the
negative charges on the fluorine and oxygen atoms. Throughout all simulations, we
observe that backbone hydrogen bonds are very sensitive to the perturbations and
are easily broken. In contrast, the hydrophobic core survives most perturbations.
In the decisive test of fluorination, the fluorinated peptide remains folded
under our simulation conditions (5 ns, 278 K). Hydrophobic interactions keep the
peptide folded, even with a repulsive force between the beta-strands. Thus, our
results strongly support a side-chain centric view for protein folding.
PMID- 10686107
TI - Preformed secondary structure drives the association reaction of GCN4-p1, a model
coiled-coil system.
AB - The structure of the transition state for the rate-limiting step in the folding
and association of the homodimeric coiled-coil peptide GCN4-p1, was probed by
mutational analysis. A series of quadruple amino acid replacements that spanned
the helix propensity scale were made at the four external f positions in the
heptad repeat. Equilibrium and kinetic circular dichroism studies demonstrate
that both the stability and the unfolding and refolding rate constants vary with
helix propensity but also reflect interactions of the altered side-chains with
their local environments. Pairwise replacements and fragment studies show that
the two C-terminal heptads are the likely source of the nucleating helices. Helix
helix recognition between preformed elements of secondary structure plays an
important role in this fundamental folding reaction.
PMID- 10686108
TI - Three-dimensional structure of a presynaptic neurotoxic phospholipase A2 from
Daboia russelli pulchella at 2.4 A resolution.
AB - The phospholipase A(2 )from Daboia russelli pulchella (DPLA(2)) is the only known
member of subclass II of group IIA. The three-dimensional structure of this
presynaptic neurotoxic DPLA(2) enzyme has been determined at 2.4 A resolution.
The structure was determined by the molecular replacement method using the model
Crotalus atrox, and refined using X-PLOR to a final R-factor of 18.8 % for all
data in the resolution range 20.0 A-2.4 A. The final refined model comprises 1888
atoms from two crystallographically independent protein molecules and 160 water
oxygen atoms. The overall folding of DPLA(2), with three long helices and two
short antiparallel beta-strands is grossly similar to those observed for other
PLA(2)s. In the present structure, the calcium binding site is empty but the
conformation of the calcium binding loop is similar to those observed in the
calcium bound states. Two spatially adjacent regions of residues 55-61 (a typical
beta-turn I) and 83-94 (a well defined loop) are remarkably different in
conformation, electrostatic characteristics and inter-segmental interactions from
those found in non-neurotoxic PLA(2)s. Yet another striking structural feature in
DPLA(2 )pertains to the stretch of residues 53-77, which has a series of
positively charged residues protruding outwardly. The above segment is presumed
to be involved in the anticoagulant activity. A unique hydrophobic patch
including residues Leu17, Ala18, Ile19, Pro20, Phe106 and Leu110 is found on the
surface together with an equally emphatic region of -OH groups containing
residues such as Ser21, Tyr22, Ser23, Ser24, Tyr25 and Tyr28. The interactions
between two molecules of DPLA(2) in the asymmetric unit are remarkably different
from those observed in the standard dimers and trimers of PLA(2)s, leaving the
enzyme's active site fully exposed for enzyme-substrate reactions, it makes this
structure one of the most favourable examples for structure-based drug design
through soaking experiments.
PMID- 10686109
TI - Luminescence control in the marine bacterium Vibrio fischeri: An analysis of the
dynamics of lux regulation.
AB - A mathematical model has been developed based on the fundamental properties of
the control system formed by the lux genes and their products in Vibrio fischeri.
The model clearly demonstrates how the components of this system work together to
create two, stable metabolic states corresponding to the expression of the
luminescent and non-luminescent phenotypes. It is demonstrated how the cell can
"switch" between these steady states due to changes in parameters describing
metabolic processes and the extracellular concentration of the signal molecule N
3-oxohexanoyl-l-homoserine lactone. In addition, it is shown how these parameters
influence how sensitive the switch mechanism is to cellular LuxR and N-3
oxohexanoyl-l-homoserine lactone and complex concentration. While these
properties could lead to the collective phenomenon known as quorum sensing, the
model also predicts that under certain metabolic circumstances, basal expression
of the lux genes could cause a cell to luminesce in the absence of extracellular
signal molecule. Finally, the model developed in this study provides a basis for
analysing the impact of other levels of control upon lux regulation.
PMID- 10686110
TI - Characterization of novel proteins based on known protein structures.
AB - The genome sciences face the challenge to characterize structure and function of
a vast number of novel genes. Sequence search techniques are used to infer
functional and structural information from similarities to experimentally
characterized genes or proteins. The persistent goal is to refine these
techniques and to develop alternative and complementary methods to increase the
range of reliable inference.Here, we focus on the structural and functional
assignments that can be inferred from the known three-dimensional structures of
proteins. The study uses all structures in the Protein Data Bank that were known
by the end of 1997. The protein structures released in 1998 were then
characterized in terms of functional and structural similarity to the previously
known structures, yielding an estimate of the maximum amount of information on
novel protein sequences that can be obtained from inference techniques. The 147
globular proteins corresponding to 196 domains released in 1998 have no clear
sequence similarity to previously known structures. However, 75 % of the domains
have extensive structure similarity to previously known folds, and most
importantly, in two out of three cases similarity in structure coincides with
related function. In view of this analysis, full utilization of existing
structure data bases would provide information for many new targets even if the
relationship is not accessible from sequence information alone. Currently, the
most sophisticated techniques detect of the order of one-third of these
relationships.
PMID- 10686111
TI - A motif for quinone binding sites in respiratory and photosynthetic systems.
AB - Many of the membrane-bound protein complexes of respiratory and photosynthetic
systems are reactive with quinones. To date, no clear structural relationship
between sites that bind quinone has been defined, apart from that in the
homologous family of "type II" photosynthetic reaction centres. We show here that
a structural element containing a weak sequence motif is common to the Q(A) and
Q(B) sites of bacterial reaction centres and the Q(i) site of the mitochondrial
bc(1) complex. Analyses of sequence databases indicate that this element may also
be present in the PsaA/B subunits of photosystem I, in the ND4 and ND5 subunits
of complex I and, possibly, in the mitochondrial alternative quinol oxidase. This
represents a first step in the structural classification of quinone binding
sites.
PMID- 10686112
TI - Time perception and motor timing: a common cortical and subcortical basis
revealed by fMRI.
AB - Though it is well known that humans perceive the temporal features of the
environment incessantly, the brain mechanisms underlying temporal processing are
relatively unexplored. Functional magnetic resonance imaging was used in this
study to identify brain activations during sustained perceptual analysis of
auditorally and visually presented temporal patterns (rhythms). Our findings show
that the neural network supporting time perception involves the same brain areas
that are responsible for the temporal planning and coordination of movements.
These results indicate that time perception and motor timing rely on similar
cerebral structures.
PMID- 10686113
TI - Cocaine activation discriminates dopaminergic projections by temporal response:
an fMRI study in Rat.
AB - We applied a sensitive new functional magnetic resonance imaging technique to
identify the pattern and determinants of cocaine-induced brain activation in drug
naive rats. At doses greater than 0.1 mg/kg iv, cocaine produced robust
activation throughout cortex with the largest magnitude increase in frontal
neocortex. Additionally, we detected selective activation within dopamine
innervated subcortical regions including dorsomedial and ventrolateral striatum,
nucleus accumbens region, and dorsal thalamus. Although dose response was similar
among activated regions, temporal response differentiated regions along distinct
anatomical boundaries with basal ganglia and limbic cortical structures, reaching
maximum activation later than frontal neocortex. Pharmacological specificity was
demonstrated by blocking cocaine-induced activation with SCH-23390, a selective
D1 antagonist. Our data demonstrate the utility of fMRI to identify
spatiotemporal patterns of cocaine-induced brain activation and implicate D1
dopaminergic mechanisms in acute cocaine action.
PMID- 10686114
TI - Detection of consistently task-related activations in fMRI data with hybrid
independent component analysis.
AB - fMRI data are commonly analyzed by testing the time course from each voxel
against specific hypothesized waveforms, despite the fact that many components of
fMRI signals are difficult to specify explicitly. In contrast, purely data-driven
techniques, by focusing on the intrinsic structure of the data, lack a direct
means to test hypotheses of interest to the examiner. Between these two extremes,
there is a role for hybrid methods that use powerful data-driven techniques to
fully characterize the data, but also use some a priori hypotheses to guide the
analysis. Here we describe such a hybrid technique, HYBICA, which uses the
initial characterization of the fMRI data from Independent Component Analysis and
allows the experimenter to sequentially combine assumed task-related components
so that one can gracefully navigate from a fully data-derived approach to a fully
hypothesis-driven approach. We describe the results of testing the method with
two artificial and two real data sets. A metric based on the diagnostic Predicted
Sum of Squares statistic was used to select the best number of spatially
independent components to combine and utilize in a standard regressional
framework. The proposed metric provided an objective method to determine whether
a more data-driven or a more hypothesis-driven approach was appropriate,
depending on the degree of mismatch between the hypothesized reference function
and the features in the data. HYBICA provides a robust way to combine the data
derived independent components into a data-derived activation waveform and
suitable confounds so that standard statistical analysis can be performed.
PMID- 10686115
TI - Passive and active recognition of one's own face.
AB - Facial identity recognition has been studied mainly with explicit discrimination
requirement and faces of social figures in previous human brain imaging studies.
We performed a PET activation study with normal volunteers in facial identity
recognition tasks using the subject's own face as visual stimulus. Three tasks
were designed so that the activation of the visual representation of the face and
the effect of sustained attention to the representation could be separately
examined: a control-face recognition task (C), a passive own-face recognition
task (no explicit discrimination was required) (P), and an active own-face
recognition task (explicit discrimination was required) (A). Increased skin
conductance responses during recognition of own face were seen in both task P and
task A, suggesting the occurrence of psychophysiological changes during
recognition of one's own face. The left fusiform gyrus, the right supramarginal
gyrus, the left putamen, and the right hypothalamus were activated in tasks P and
A compared with task C. The left fusiform gyrus and the right supramarginal gyrus
are considered to be involved in the representation of one's own face. The
activation in the right supramarginal gyrus may be associated with the
representation of one's own face as a part of one's own body. The prefrontal
cortices, the right anterior cingulate, the right presupplementary motor area,
and the left insula were specifically activated during task A compared with tasks
C and P, indicating that these regions may be involved in the sustained attention
to the representation of one's own face.
PMID- 10686116
TI - Characterization and correction of interpolation effects in the realignment of
fMRI time series.
AB - Subject motion in functional magnetic resonance imaging (fMRI) studies can be
accurately estimated using realignment algorithms. However, residual changes in
signal intensity arising from motion have been identified in the data even after
realignment of the image time series. The nature of these artifacts is
characterized using simulated displacements of an fMRI image and is attributed to
interpolation errors introduced by the resampling inherent within realignment. A
correction scheme that uses a periodic function of the estimated displacements to
remove interpolation errors from the image time series on a voxel-by-voxel basis
is proposed. The artifacts are investigated using a brain phantom to avoid
physiological confounds. Small- and large-scale systematic displacements show
that the artifacts have the same form as revealed by the simulated displacements.
A randomly displaced phantom and a human subject are used to demonstrate that
interpolation errors are minimized using the correction.
PMID- 10686117
TI - Real-time monitoring of eye movements using infrared video-oculography during
functional magnetic resonance imaging of the frontal eye fields.
AB - Monitoring eye movements is a critical aspect of experimental design for studies
of spatial attention and visual perception. However, obtaining online eye
movement recordings has been technologically difficult during functional magnetic
resonance (MR) imaging studies. Previous approaches to monitoring eye movements
either have distorted the MR images or have shown MR-related interference in the
recordings. We report a technique using long-range infrared video-oculography to
record eye movements without causing artifacts in the MR images. Analysis of the
MR signal from a phantom obtained with the eye-movement equipment turned on or
off confirmed the absence of significant additional noise in the MR time series.
Eye movements of three subjects were monitored while they performed tasks of
covert and overt shifts of spatial attention. Activation of the frontal eye
fields during the covert task was seen even when the eye-movement recordings
demonstrated no significant difference in saccadic eye movements between the
baseline and the active conditions.
PMID- 10686118
TI - Brodmann's areas 17 and 18 brought into stereotaxic space-where and how variable?
AB - Studies on structural-functional associations in the visual system require
precise information on the location and variability of Brodmann's areas 17 and
18. Usually, these studies are based on the Talairach atlas, which does not rely
on cytoarchitectonic observations, but on comparisons of macroscopic features in
the Talairach brain and Brodmann's drawing. In addition, in this atlas are found
only the approximate positions of cytoarchitectonic areas and not the exact
borders. We have cytoarchitectonically mapped both areas in 10 human brains and
marked their borders in corresponding computerized images. Borders were defined
on the basis of quantitative cytoarchitecture and multivariate statistics. In
addition to borders of areas 17 and 18, subparcellations within both areas were
found. The cytoarchitectonically defined areas were 3-D reconstructed and
transferred into the stereotaxic space of the standard reference brain. Surface
rendering of the brains revealed high individual variability in size and shape of
the areas and in the relationship to the free surface and sulci. Ranges and
centers of gravity of both areas were calculated in Talairach coordinates. The
positions of areas 17 and 18 in the stereotaxic space differed between the
hemispheres. Both areas reached significantly more caudal and medial positions on
the left than on the right. Probability maps were created in which the degree of
overlap in each stereotaxic position was quantified. These maps of areas 17 and
18 are the first of their kind and contain precise stereotaxic information on
both interhemispheric and interindividual differences.
PMID- 10686119
TI - Effects of environmental enrichment on rate of contextual processing and
discriminative ability in adult rats.
AB - The effect of environmental enrichment on conditioned freezing to contextual cues
in adult Sprague-Dawley rats was examined. The freezing of both enriched-and
standard-reared rats increased with the time spent in the chamber prior to shock.
Both groups of rats showed equally low levels of contextual conditioning
following a preshock period of 4 s and equally high levels following a 120-s
preshock period. However, following a preshock period of 16 s enriched rats
displayed more contextual conditioning than standard rats. That is, enriched rats
appeared to process contextual information faster than their standard-reared
counterparts. Enriched- reared rats also showed a greater ability to discriminate
between the conditioning context and a similar but distinctive context. Hence, in
addition to forming a representation of the context in memory more rapidly than
standard-reared rats, enriched-reared rats also appear to form a more complex
representation.
PMID- 10686120
TI - Time-dependent impairment of inhibitory avoidance retention in rats by
posttraining infusion of a mitogen-activated protein kinase kinase inhibitor into
cortical and limbic structures.
AB - Mitogen-activated protein kinase (MAPK) is abundantly expressed in postmitotic
neurons of the developed nervous system. MAPK is activated and required for
induction of long-term potentiation (LTP) in the CA1 area of the hippocampus,
which is blocked by the specific inhibitor of the MAPK kinase, PD 098059.
Recently it was demonstrated that MAPK is activated in the hippocampus after
training and is necessary for contextual fear conditioning learning. The present
work tests the role of the MAPK cascade in step-down inhibitory avoidance (IA)
retention. PD 098059 (50 microM) was bilaterally injected (0.5 microl/side) into
the CA1 region of the dorsal hippocampus or entorhinal cortex at 0, 90, 180, or
360 min, or into the amygdala or parietal cortex at 0, 180, or 360 min after IA
training in rats using a 0.4-mA foot shock. Retention testing was carried out 24
h after training. PD 098059 impaired retention when injected into the dorsal
hippocampus at 180 min, but not 0, 90, and 360 min after training. When infused
into the entorhinal cortex, PD 098059 was amnestic at 0 and 180 min, but not at
90 and 360 min after training. The MAPKK inhibitor also impairs IA retention when
infused into the parietal cortex immediately after training, but not at 180 or
360 min. Infusions performed into amygdala were amnestic at 180 min, but not at 0
and 360 min after training. Our results suggest a time-dependent involvement of
the MAPK cascade in the posttraining memory processing of IA; the time dependency
is different in the hippocampus, amygdala, entorhinal cortex, or parietal cortex
of rats.
PMID- 10686121
TI - Injections of tacrine and scopolamine into the nucleus accumbens: opposing
effects of immediate vs delayed posttrial treatment on memory of an open field.
AB - Using the paradigm of habituation learning in the open field, we tested the
effects of microinjections of the nonspecific acetylcholine-esterase inhibitor
tacrine (0.1, 1.0, 10.0 micrograms), and the muscarinic receptor antagonist
scopolamine (0.1, 1.0, 10.0 micrograms) into the core of the nucleus accumbens.
When injected immediately after the first exposure to the open field (posttrial),
tacrine dose-dependently enhanced habituation of rearing behavior during the test
on the following day, indicating a facilitation of memory. In contrast,
scopolamine impaired habituation of rearing behavior at the two lower doses, but
not at the highest dose. When scopolamine or tacrine (10.0 micrograms) was
injected with a delay of 5 h after the learning trial, both drugs impaired
habituation of rearing on the following day. The effects on locomotor activity
differed from those on rearing behavior. Here, habituation on Day 2 was observed
only in those animals which had received posttrial injections of vehicle or 10
micrograms of tacrine on the day before, whereas in animals which had received
the two lower doses of tacrine, locomotor activity on Day 2 was not significantly
decreased. In animals with posttrial treatment of scopolamine, locomotor activity
on Day 2 was even enhanced, especially with the lower doses. No such effects were
observed when scopolamine or tacrine (10.0 micrograms each) was injected with a
delay of 5 h after the learning trial. These results show that cholinergic
manipulations aimed at the nucleus accumbens can have substantial effects in this
posttrial memory paradigm, which depend on drug, dose, and time of injection, and
the specific kind of behavioral measure analyzed. Among others, the findings are
discussed with respect to the role of muscarinic and nicotinergic cholinergic
mechanisms in the nucleus accumbens on cognitive functions. They may be relevant,
for example, for understanding the psychopathology of Alzheimer's disease, since
the nucleus accumbens is one of the sites where cholinergic neurons are lost in
this neurodegenerative disease.
PMID- 10686122
TI - Genetic differences in response to novelty and spatial memory using a two-trial
recognition task in mice.
AB - A two-trial memory task, based on a free-choice exploration paradigm in a Y-maze,
was previously developed to study recognition processes in Sprague-Dawley rats.
Because this paradigm avoids the use of electric shock or deprivation that may
have nonspecific effects and does not require learning of a rule, it may be
particularly useful for studying memory in mice. Four inbred strains (Balb/cByJ,
DBA/2J, C57BL/6J, and SJL/J), an F1 hybrid (C57BL/6 x SJL/J), and one outbred
strain (CD1) were used to validate this task in mice and to characterize a strain
distribution in response to novelty and working memory. Exploration was measured
with a short (2 min) intertrial interval (ITI) between acquisition and retrieval,
while memory was examined with longer intervals (30 min, 1 h, and 2 h). A study
of the time course of the response to novelty revealed varying degrees of
preference and/or habituation to novelty among the different strains, with CD1
exhibiting a very high response to novelty and others showing lower (C57 x SJL
hybrids) to complete absence (SJL) of exploration of novelty. Memory span,
assessed with increasing ITIs, varied widely among strains from 30 min (C57 x SJL
hybrids) to at least 2 h (C57 and BALB). Such demonstrated sensitivity to a wide
range of behavioral phenotypes supports the use of this spatial memory task as an
effective tool for the study of genetic influences on the response to novelty and
recognition processes in mice.
PMID- 10686123
TI - Enhanced visuospatial memory following intracerebroventricular administration of
nerve growth factor.
AB - The present work assessed the effects of intracerebroventricular injections of rh
recombined human nerve growth factor (rh NGF) (5 micrograms/2.5 microl) at
postnatal days 12 and 13 upon the development of spatial learning capacities. The
treated rats were trained at the age of 22 days to escape onto an invisible
platform at a fixed position in space in a Morris navigation task. For half of
the subjects, the training position was also cued, a procedure aimed at
facilitating escape and at reducing attention to the distant spatial cues. Later,
at the age of 6 months, all the rats were trained in a radial-arm maze task.
Treatment effects were found in both immature and adult rats. The injection of
NGF improved the performance in the Morris navigation task in both training
conditions. There was a significant reduction in the escape latency and an
increased bias toward the training platform quadrant during probe trials. The
most consistent effect was the precocious development of an adult-like spatial
memory. In the radial-arm maze, the NGF-treated rats made significantly fewer
reentries than vehicle rats and this effect was particularly marked in the
treated female rats. Taken together, these experiments reveal that the
development and the maintenance of an accurate spatial representation are tightly
related to the development of brain structures facilitated by the action of NGF.
Moreover, these experiments demonstrate that an acute pharmacological treatment
that leads to a transient modification in the choline acetyltransferase activity
can induce a behavioral change long after the treatment.
PMID- 10686124
TI - Effects of selective perirhinal and postrhinal lesions on acquisition and
retention of a visual discrimination task in rats.
AB - The hippocampal region along with rhinal structures seems to support learning and
memory in an important manner. Structures adjacent to the rhinal fissure in the
rat have recently been suggested to be divided into the perirhinal and postrhinal
cortices. Some effects of perirhinal lesions on cognitive processing are known,
whereas effects of postrhinal lesions appear to be unknown. The purpose of the
present study was to examine the relative effects of perirhinal and postrhinal
lesions in a three-choice visual discrimination test. The results show that both
types of lesions impaired acquisition of the task, but only perirhinal lesions
impeded subsequent retention. Because the initial phase of acquisition was
unaffected by both lesions, it is suggested that the deficits observed may be of
mnemonic nature. The apparent differential involvement of the perirhinal cortex
and postrhinal cortex in cognition may be associated with differences in
anatomical connectivity among these structures.
PMID- 10686125
TI - Epinephrine fails to enhance performance of food-deprived rats on a delayed
spontaneous alternation task.
AB - Increases in blood glucose levels after epinephrine injection appear to
contribute to the hormone's effects on learning and memory. The present
experiment evaluated whether epinephrine-induced enhancement of spontaneous
alternation performance would be attenuated in fasted rats that had blunted
increases in circulating glucose levels after injections of epinephrine. Rats
deprived of food for 24 h prior to injection of epinephrine exhibited significant
attenuation of the increase in blood glucose levels seen in fed rats. When the
rats were tested on a delayed spontaneous alternation task, epinephrine enhanced
performance in fed rats but not in rats deprived of food for 24 h. These findings
are consistent with the view that hyperglycemia subsequent to epinephrine
injections contributes to the memory-enhancing effects of epinephrine.
PMID- 10686126
TI - Evidence for altered Fragile-X mental retardation protein expression in response
to behavioral stimulation.
AB - The Fragile-X mental retardation protein, the protein absent in Fragile-X
syndrome, is synthesized near synapses upon neurotransmitter activation. Humans
and mice lacking this protein exhibit abnormal dendritic spine lengths and
numbers. Here we investigated Fragile-X protein levels in animals exposed to
behavioral paradigms that induce neuronal morphological change. Fragile-X protein
immunoreactivity was examined in visual cortices of rats reared in a complex
environment for 10 or 20 days, motor cortices of rats trained on motor-skill
tasks for 3 or 7 days, and either visual or motor cortices of inactive controls.
Rats exposed to a complex environment for 20 days or trained for 7 days on motor
skill tasks exhibited increased Fragile-X protein immunoreactivity in visual or
motor cortices, respectively. These results provide the first evidence for a
behaviorally induced alteration of Fragile-X protein expression and are
compatible with previous findings suggesting synaptic regulation of its
expression. These results also strengthen the association of Fragile-X mental
retardation protein expression with the alteration of synaptic structure.
PMID- 10686127
TI - Shuttle-box avoidance learning in mice: improvement by glucose combined with
stimulant drugs.
AB - Glucose was tested alone or in combination with two stimulant drugs, amphetamine
and nicotine, in mice of the CD-1 strain subjected to five daily shuttle-box
training sessions. Pretraining intraperitoneal administration of glucose (50 or
100 mg/kg) had no effect, while amphetamine and nicotine, given alone,
significantly improved avoidance acquisition at a dose of 0.5 mg/kg, but not
0.025 mg/kg. Significant improvement of avoidance learning was also produced by a
combination of glucose with the lower dose of amphetamine or nicotine. This
enhancing action, produced by a combination of glucose and stimulant drugs, at
doses ineffective by themselves, might be due to a concomitant cholinergic and
dopaminergic activation, induced by glucose and stimulant drugs, respectively.
PMID- 10686128
TI - The genes for benzene catabolism in Pseudomonas putida ML2 are flanked by two
copies of the insertion element IS1489, forming a class-I-type catabolic
transposon, Tn5542.
AB - Two directly repeated sequences of the IS elements IS1489v1 and IS1489v2 flank
the benzene dioxygenase (bedC1C2BA) and the cis-benzene dihydrodiol dehydrogenase
(bedD) genes on the catabolic plasmid pHMT112 in Pseudomonas putida ML2, forming
a Class-I-type composite transposon, Tn5542. Both IS1489v1 and IS1489v2 contain
an identical 1371-bp open reading frame, tnpA, that is preceded by a possible
ribosome binding site. The tnpA gene of IS1489v1 is bound by a pair of 40-bp
imperfect inverted repeats while that of IS1489v2 is flanked only by the left
inverted repeat. The tnpA gene codes for a putative 53-kDa polypeptide of 456
amino acids bearing similarity to transposases encoded on IS elements of P.
alcaligenes, P. aeruginosa, P. stutzeri, and Serratia marcescens. The basic
nature of the putative TnpA protein with a deduced pI of 8.93 is typical of IS
encoded transposases. Similar to other IS elements, an outward facing promoter
was detected at the right end of IS1489v1. Experiments involving the suicide
vector, pKNG101, failed to show transposition of Tn5542.
PMID- 10686129
TI - Nucleotide sequence and analysis of plasmid pMD136 from Pediococcus pentosaceus
FBB61 (ATCC43200) involved in pediocin A production.
AB - The complete sequence of the 19515-bp plasmid pMD136 from Pediococcus pentosaceus
FBB61 (ATCC43200) has been determined. This plasmid is involved in Pediocin A
production, a bacteriocin active against a wide range of gram-positive bacteria.
It appears to replicate via a theta mechanism, with structures closely related to
those of many lactococcal plasmids. Genes homologous to mobilization functions
are also present, which are similar in sequence and arrangement to mobA, mobB,
and mobC of some staphylococcal plasmids, although the last one contains a
deletion in its central part. The region involved in bacteriocin activity has
been limited to a 9.4-kb fragment, containing 10 open reading frames organized in
a single operon. Since Pediocin A has a molecular weight of about 80 kDa (Piva
and Headon, Microbiology, 140, 697-702, 1994), and a gene long enough to encode
it is not present in pMD136, it is proposed that genes residing on the plasmid
are responsible for the regulation of bacteriocinogenic activity. Gene
arrangement and sequence homologies suggest the presence of a two-component-like
regulatory mechanism.
PMID- 10686131
TI - Nucleotide sequence analysis of the lactococcal EPS plasmid pNZ4000.
AB - The complete 42180-bp nucleotide sequence of the mobilization plasmid pNZ4000,
coding for exopolysaccharide (EPS) production in Lactococcus lactis, was
determined. This plasmid contains a region involved in EPS biosynthesis, four
functional replicons, a region containing mobilization genes, and three origin of
transfer (oriT) sequences. Sequences identical to these oriT sequences were also
found on two other lactococcal plasmids and a plasmid from Lactobacillus
helveticus. Several complete and partial IS elements were identified on pNZ4000,
including iso-ISS1, iso-IS946, and iso-IS982 sequences. Furthermore, pNZ4000
contains a gene cluster that may encode a cobalt transport system and a gene that
encodes a CorA homologue which may function as a magnesium transporter.
PMID- 10686130
TI - Coupling sequences flanking Tn916 do not determine the affinity of binding of
integrase to the transposon ends and adjacent bacterial DNA.
AB - Coupling sequences are the 6 bp flanking the conjugative transposon Tn916 and are
thought to play a role in determining the frequency of conjugative transposition.
The affinity of binding of a chimeric protein, which consisted of maltose binding
protein fused to the carboxy-terminal DNA binding domain of Tn916 integrase
(Int), to different double-stranded oligonucleotide substrates containing
coupling sequences associated with high- and low-frequency conjugative
transposition was measured using a competition binding assay. The relative
affinity of the chimeric protein was unaffected by the nature of the coupling
sequences tested. The same results were obtained when the coupling sequences were
placed in a different surrounding sequence context. It therefore appears that the
effects of different coupling sequences on the frequency of conjugative
transposition are not due simply to differences in Int binding.
PMID- 10686132
TI - Telomere sequences attached to nuclearly migrated yeast linear plasmid.
AB - The yeast linear plasmid pCLU1, derived from pGKL1, has terminal proteins (TPs)
covalently attached at the 5' ends of inverted terminal repeats (ITRs) and
replicates in the cytoplasm, presumably using the TP as a primer for DNA
synthesis. In Saccharomyces cerevisiae, under certain conditions, pCLU1 migrated
into the nucleus and replicated in either linear or circular form. The linear
form plasmid lacked TPs; instead it carried host-telomere repeats at the ITR
ends. The present study showed that (1) the added telomere was primarily composed
of the repeated tracts of TGTGTGGGTGTGG, which was complementary to the RNA
template of yeast telomerase, (2) the telomeric addition occurred at the very end
of the ITRs, and (3) the sequence composition of the added telomeres was diverse
among individual plasmids, but symmetrically identical at both ends of each
plasmid. A similar mode of telomere addition was also observed in cells defective
in the RAD52 gene.
PMID- 10686133
TI - Complete DNA sequence and analysis of an emerging cryptic plasmid isolated from
Yersinia pestis.
AB - A 6-kb cryptic plasmid (pYC; 5919 bp) has been recovered from Yersinia pestis
isolates originating from regions of Yunnan province in China. The sequence of
pYC was determined, and analysis of the sequence has revealed that two of the
plasmid DNA regions (ORFs 10 and 11) are similar to the DinJ1 and DinJ2 gene
products encoded by Escherichia coli chromosomal DNA. This plasmid is
increasingly harbored by Y. pestis isolates recovered from a domestic rodent
cycle in the southern regions of the province. Further studies will determine the
origin and function of pYC.
PMID- 10686134
TI - The pilL and pilN genes of IncI1 plasmids R64 and ColIb-P9 encode outer membrane
lipoproteins responsible for thin pilus biogenesis.
AB - The predicted amino acid sequences of the pilL and pilN genes, required for the
thin pilus formation of IncI1 plasmids R64 and ColIb-P9, contain N-terminal
lipoprotein signal peptide motifs. The pilL and pilN products were labeled with
[(3)H]palmitic acid as 38- and 57-kDa proteins, respectively, indicating that
they are lipoproteins. Both PilL and PilN were localized to the outer membrane.
PMID- 10686135
TI - Detection, cloning, and sequence analysis of an indigenous plasmid from
cellulolytic clostridial strain MCF1.
AB - Nucleotide sequence analysis of a 2451-bp plasmid (pMCF1) from a cellulolytic
Clostridium revealed that the protein specified by the largest open reading frame
(ORF1) was homologous to RepB of Clostridium butyricum plasmid pCB101. The data
suggest that pMCF1 belongs to the pC194 family of rolling-circle replicating
plasmids and the ORF1 protein functions as its replication protein.
PMID- 10686136
TI - Complete nucleotide sequence and characterization of pSNA1 from pimaricin
producing Streptomyces natalensis that replicates by a rolling circle mechanism.
AB - A cryptic plasmid, pSNA1, has been identified in the pimaricin-producing
Streptomyces natalensis strain ATCC 27448. pSNA1 has been mapped with restriction
endonucleases and its complete nucleotide sequence was determined. The circular
DNA molecule is 9367 bp in length and has a 71.3% G+C content. Its estimated copy
number is 30. Analysis of the sequence and codon preferences indicated that pSNA1
contains seven open reading frames [encoding peptides larger than 90 amino acid
(aa) residues], ORF 1 to ORF 7, located on both strands of pSNA1. ORF 3 codes for
a protein (476 aa) that shows high sequence similarity to replication-associated
proteins in Streptomyces plasmids known to replicate via the rolling circle
mechanism. Accumulation of single-strand intermediates further indicates that
pSNA1 replicates via the rolling circle replication model. ORF 1 encodes a
polypeptide of 246 aa that shares homology with KorA proteins encoded by other
streptomycete plasmids. ORF 4 (SpdA) codes for a protein (161 aa) possibly
involved in intramycelial plasmid transfer. Protein encoded by ORF 2 (309 aa)
shares homology with a Streptomyces protein (SpdB2) also involved in plasmid
spreading.
PMID- 10686137
TI - Strand switching during rolling circle replication of plasmid-like DNA circles in
the mitochondria of the higher plant Chenopodium album (L.).
AB - The structure of sigma-like mitochondrial DNA molecules prepared from suspension
cultured cells of Chenopodium album (L.) was studied by electron microscopy.
These molecules were highly variable in size, ranging from about 1 to 104 kb, and
had single- and double-stranded regions typical for rolling circle replicating
intermediates. Partial denaturation studies confirmed that these structures
constitute rolling circles. Close inspection of the circle-tail junctions of the
replication fork at high magnification suggests that in circles with a double
stranded tail, both strands of the tail seem to be covalently attached to the
circle in about 27% of the molecules. This observation can be explained by a
phenomenon called strand switching or strand splippage during rolling circle
replication, similar to a mechanism proposed for bacterial replicons or in vitro
replicating constructs harboring bacteriophage T4 replication origins.
PMID- 10686138
TI - Transfer of conjugative plasmids and bacteriophage lambda occurs in the presence
of antibiotics that prevent de novo gene expression.
AB - Plasmids transferred between bacteria prevented from expressing genes by the
presence of bacteriostatic antibiotics. Whereas it has long been known that de
novo gene expression is not required in donor cells for conjugation, the
observations reported here extend the autonomy of plasmid transfer to the early
events of establishment in recipients. In addition, this phenomenon was extended
to bacteriophage lambda.
PMID- 10686139
TI - Possible benefits of kalilo plasmids to their Neurospora hosts.
AB - Neurospora mitochondrial plasmids are ubiquitous in natural populations, yet many
of them are lethal to their host strains or seem to impose a molecular genetic
load. Five pairs of strains of Neurospora tetrasperma and N. crassa with and
without kalilo-like plasmids were tested under a variety of situations. The
purpose was to find possible beneficial effects of plasmids that might offset
their disadvantages. We found that, in all cases tested, plasmids conferred an
advantage to growth at temperatures close to the top of the range for this
fungus. Also, the plasmids improved fertility, as measured by perithecial
production. Negative results were obtained for heavy metal resistance and
ascospore germination. The results generate the hypothesis that plasmids may have
adaptive significance to their hosts.
PMID- 10686140
TI - Search for a novel killer toxin in yeast Pichia pastoris.
AB - Certain yeast strains secrete a protein toxin, which inhibits the growth of
sensitive pathogens and yeasts. Studies have shown that production of the toxin
is dependent on presence of linear, double-stranded DNA plasmids in the killer
yeasts. In the yeast Pichia pastoris, two linear double-stranded DNA plasmids
have been identified. In the present study, the search for toxin-producing
capability in P. pastoris has been conducted. No killer activity could be
detected when 14 different indicator strains were tested.
PMID- 10686141
TI - Single-step purification of recombinant human growth hormone (hGH) directly from
bacterial osmotic shock fluids, for the purpose of (125)I-hGH preparation.
AB - A good quality tracer, to be used in the radioimmunoassay of human growth
hormone, was prepared by applying the chloramine-T iodination technique to the
recombinant product obtained after a single-step high-performance size-exclusion
chromatography purification of a bacterial osmotic shock fluid. The labeling
reaction presented a yield of about 65% and the purified tracer exhibited an
antibody binding of approximately 50% (NIDDK reference antiserum diluted
1:600,000). These values are very similar to those obtained by radioiodinating
highly purified clinical-grade recombinant human growth hormone obtained from the
same periplasmic extract after the regular six-step purification process. Both
tracers provided the same accuracy, when evaluated with the use of commercial
quality control samples in a classical radioimmunoassay methodology, their
stability being practically identical: about 18% decrease in antibody binding
after 2 months of storage at -20 degrees C. The novel approach permits the
utilization of transformed Escherichia coli strains as a source of freshly
prepared, radioiodination-grade recombinant proteins, capable of providing better
reproducibility and reagent continuity.
PMID- 10686142
TI - Production of fluorescent single-chain antibody fragments in Escherichia coli.
AB - We describe a novel vector-host system suitable for the efficient preparation of
fluorescent single-chain antibody Fv fragments (scFv) in Escherichia coli. The
previously described pscFv1F4 vector used for the bacterial expression of
functional scFv to the E6 protein of human papillomavirus type 16 was modified by
appending to its C-terminus the green fluorescent protein (GFP). The expression
of the scFv1F4-GFP fusion proteins was monitored by analyzing of the typical GFP
fluorescence of the transformed cells under UV illumination. The brightest signal
was obtained when scFv1F4 was linked to the cycle 3 GFP variant (GFPuv) and
expressed in the cytoplasm of AD494(DE3) bacteria under control of the arabinose
promoter. Although the scFv1F4 expressed under these conditions did not contain
disulfide bridges, about 1% of the molecules were able to bind antigen.
Fluorescence analysis of antigen-coated agarose beads incubated with the
cytoplasmic scFv-GFP complexes showed that a similar proportion of fusions
retained both E6-binding and green-light-emitting activities. The scFv1F4-GFPuv
molecules were purified by affinity chromatography and successfully used to
detect viral E6 protein in transfected COS cells by fluorescence microscopy. When
an anti-beta-galactosidase scFv, which had previously been adapted to cytoplasmic
expression at high levels, was used in this system, it was possible to produce
large amounts of functional fluorescent antibody fragments. This indicates that
these labeled scFvs may have many applications in fluorescence-based single-step
immunoassays.
PMID- 10686143
TI - Purification and characterization of macrodontain I, a cysteine peptidase from
unripe fruits of Pseudananas macrodontes (Morr.) harms (Bromeliaceae).
AB - A new papain-like cysteine peptidase isolated from fruits of Pseudananas
macrodontes (Morr.) Harms, a species closely related to pineapple (Ananas comosus
L.), has been purified and characterized. The enzyme, named macrodontain I, is
the main proteolytic component present in fruit extracts and was purified by
acetone fractionation followed by anion-exchange chromatography. Separation was
improved by selecting both an adequate pH value and a narrow saline gradient.
Optimum pH range (more than 90% of maximum activity with casein) was achieved at
pH 6.1-8.5. Homogeneity of the enzyme was confirmed by bidimensional
electrophoresis and mass spectroscopy (MS). Molecular mass of the enzyme was
23,459 (MS) and its isoelectric point was 6.1. The alanine, glutamine, and
tyrosine derivatives were strongly preferred when the enzyme was assayed on N
alpha-CBZ-l-amino acid p-nitrophenyl esters. The N-terminal sequence of
macrodontain (by comparison with the N-terminus of 30 plant proteases with more
than 50% homology) showed a great deal of sequence similarity to the other
pineapple-stem-derived cysteine endopeptidases, being 85.7, 85. 2, and 77.8%
identical to comosain, stem bromelain, and ananain, respectively. It seems clear
that the Bromeliaceae endopeptidases are more closely related to each other than
to other members of the papain family, suggesting relatively recent divergence.
PMID- 10686144
TI - Production, purification, and properties of an extracellular laccase from
Rigidoporus lignosus.
AB - Laccase from Rigidoporus lignosus, a white-rot basidiomycete, has been isolated
from culture filtrates. The enzyme was purified to homogeneity and some of its
structural and kinetic parameters have been determined. The effects of pH,
temperature, and organic solvents on the activity and stability of the enzyme,
under different conditions, were also assayed. The results we have obtained,
including the rather broad substrate specificity of enzyme, combined with their
relatively easy production and purification, suggest that laccase may be
efficiently employed in a variety of biotechnology applications.
PMID- 10686145
TI - Replication-associated activities of purified human papillomavirus type 11 E1
helicase.
AB - Replication of human papillomavirus type11 (HPV11) requires both the E1 and the
E2 proteins. E1 is structurally and functionally similar to SV40 large T-antigen
and is a DNA helicase/NTPase that binds to the origin of replication and
initiates viral DNA replication. The biochemical characterization of HPV E1 is
incompletely documented in the literature in part because of difficulties in
expressing and purifying the protein. Herein, we report a method for the
overexpression of full-length, untagged E1 (73.5 kDa) in baculovirus-infected
Trichoplusia ni insect cells and the purification to homogeneity using a two-step
procedure. The purified protein is a nonspecific NTPase that hydrolyzes ATP,
dATP, UTP, or GTP equally well. Point mutations were made in the putative NTPase
domain to verify that the activities observed were encoded by E1. Purified mutant
D523N had negligible ATPase and helicase activities but retained DNA-binding
activity. Sedimentation equilibrium ultracentrifugation and glycerol gradient
centrifugation demonstrated that the wild-type protein is primarily a hexamer in
its purified form. Secondary structure determination by circular dichroism
revealed a large percentage of alpha-helical structure consistent with secondary
structure predictions. These data define a fundamental set of biochemical and
kinetic parameters for HPV E1 which are a critical prerequisite to future
mechanistic studies of the enzyme.
PMID- 10686146
TI - Isolation and characterization of bovine thymus multicatalytic proteinase
complex.
AB - The multicatalytic proteinase complex (MPC or proteasome) from bovine thymus was
isolated and purified to homogeneity applying a protocol utilizing ion exchange
and gel permeation chromatography as major purification tools. The purified
complex shows molecular properties that are common for proteasomal molecules
(high molecular mass, multisubunit organization, and multiple proteolytic
activities) even though a peculiar subunit composition and the presence of
specific regulatory mechanisms affecting the assembled proteolytic activities
suggest a specialized function for this complex. Thymus proteasome is
characterized by the presence of LMP2, LMP7, and LMP10 (MECL1) subunits, which
replace the X, Y, and Z subunits. Since a similar complex was previously isolated
in bovine spleen, it appears that the proteasomal population containing the LMP
subunits is characteristic for organs involved in immune response. Both the
thymus and spleen proteasomes are characterized by a marked efficiency in
cleaving peptide bonds after branched-chain and aromatic amino acids, indicating
that this proteasomal population is most likely involved in intracellular
processing of class I antigenic peptides and is an example of an "in vivo"
functioning immunoproteasome. However, in spite of several similarities, the
complexes isolated from the two lymphoid organs do not show superimposable
functional properties, which suggests the presence of organ-specific regulatory
mechanisms affecting each of the proteolytic components assembled in the complex.
PMID- 10686147
TI - Membrane-bound human 3beta-hydroxysteroid dehydrogenase: overexpression with His
tag using a baculovirus system and single-step purification.
AB - The membrane-bound human 3beta-hydroxysteroid dehydrogenase type 1 (3beta-HSD1)
was overexpressed with His(6)-tag, using a baculovirus expression system, and
then purified by nickel-chelated affinity chromatography. Overexpression of 3beta
HSD1 was confirmed by enzyme assay and Western blot analysis. The protein was
purified to more than 95% homogeneity by a single-step Ni(2+)-chelated affinity
chromatography after solubilization of the membrane-bound protein with the
detergent C(12)E(8). High yield was repeatedly obtained, with 3-4 mg of
homogeneous and active 3beta-HSD1 from 1 x 10(9) of infected Sf9 cells. The
kinetic study showed a K(m) of 1.7 microM and a V(max) of 50 nmol/min/mg of
purified protein using dehydroepiandrosterone as the substrate. The above
preparation will facilitate the structure-function study of this important
enzyme.
PMID- 10686148
TI - Extracellular expression, purification, and characterization of a winter flounder
antifreeze polypeptide from Escherichia coli.
AB - HPLC6 is the major component of liver-type antifreeze polypeptides (AFPs) from
the winter flounder, Pleuronectes americanus. To facilitate mutagenesis studies
of this protein, a gene encoding the 37-amino acid mature polypeptide was
chemically synthesized and cloned into the Tac cassette immediately after the
bacterial ompA leader sequence for direct excretion of the AFP into the culture
medium. Escherichia coli transformant with the construct placIQpar8AF was
cultured in M9 medium. The recombinant AFP (rAFP) was detected by a competitive
enzyme-linked immunosorbent assay (ELISA). After IPTG induction, a biologically
active rAFP was expressed. The majority of the rAFP was excreted into the culture
medium with only trace amounts trapped in the periplasmic space and cytoplasm.
After 18 h of induction, the accumulated rAFP in the culture medium amounted to
about 16 mg/L. The excreted AFP was purified from the culture medium by a single
step reverse-phase HPLC. Mass spectrometric and amino acid composition analyses
confirmed the identity of the purified product. The rAFP, which lacked amidation
at the C-terminal, was about 70% active when compared to the amidated wild-type
protein, thus confirming the importance of C-terminal cap structure in protein
stability and function.
PMID- 10686149
TI - Optimization of inclusion body solubilization and renaturation of recombinant
human growth hormone from Escherichia coli.
AB - Recombinant human growth hormone (r-hGH) was expressed in Escherichia coli as
inclusion bodies. In 10 h of fed-batch fermentation, 1.6 g/L of r-hGH was
produced at a cell concentration of 25 g dry cell weight/L. Inclusion bodies from
the cells were isolated and purified to homogeneity. Various buffers with and
without reducing agents were used to solubilize r-hGH from the inclusion bodies
and the extent of solubility was compared with that of 8 M urea as well as 6 M
Gdn-HCl. Hydrophobic interactions as well as ionic interactions were found to be
the dominant forces responsible for the formation of r-hGH inclusion bodies
during its high-level expression in E. coli. Complete solubilization of r-hGH
inclusion bodies was observed in 100 mM Tris buffer at pH 12.5 containing 2 M
urea. Solubilization of r-hGH inclusion bodies in the presence of low
concentrations of urea helped in retaining the existing native-like secondary
structures of r-hGH, thus improving the yield of bioactive protein during
refolding. Solubilized r-hGH in Tris buffer containing 2 M urea was found to be
less susceptible to aggregation during buffer exchange and thus was refolded by
simple dilution. The r-hGH was purified by use of DEAE-Sepharose ion-exchange
chromatography and the pure monomeric r-hGH was finally obtained by using size
exclusion chromatography. The overall yield of the purified monomeric r-hGH was
approximately 50% of the initial inclusion body proteins and was found to be
biologically active in promoting growth of rat Nb2 lymphoma cell lines.
PMID- 10686150
TI - Expression of biologically active recombinant pokeweed antiviral protein in
methylotrophic yeast Pichia pastoris.
AB - Pokeweed antiviral protein (PAP)-I from the spring leaves of Phytolacca americana
is a naturally occurring RNA-depurinating enzyme with broad-spectrum antiviral
activity. Interest in PAP is growing due to its use as a potential anti-HIV
agent. However, the clinical use of native PAP is limited due to inherent
difficulties in obtaining sufficient quantities of homogeneously pure active PAP
without batch-to-batch variation from its natural resource. Here, we report the
expression of mature PAP (residues 23 to 284) with a C-terminal hexahistidine tag
in the methylotrophic yeast Pichia pastoris, as a secreted soluble protein. The
final yield of the secreted PAP is greater than 10 mg/L culture in shaker flasks.
The secreted recombinant protein is not toxic to the yeast cells and has an
apparent molecular mass of 33-kDa on SDS-PAGE gels. The in vitro enzymatic
activity and cellular anti-HIV activity of recombinant PAP were of the same
magnitude as those of the native PAP purified from P. americana. To our
knowledge, this is the first large-scale expression and purification of soluble
and biologically active recombinant mature PAP from yeast.
PMID- 10686151
TI - Vectors allowing amplified expression of the Saccharomyces cerevisiae Gal3p
Gal80p-Gal4p transcription switch: applications to galactose-regulated high-level
production of proteins.
AB - The Gal4, Gal80, and Gal3 proteins of Saccharomyces cerevisiae constitute a
galactose-responsive regulatory switch for GAL gene promoters. The low cellular
levels of these proteins have hampered mechanistic studies and limit the utility
of the GAL gene promoters for high-yield production of endogenous and exogenous
proteins. We have constructed two new vectors, pMEGA2 and pMEGA2-DeltaURA3, that
increase the level of the Gal4p-Gal80p-Gal3p switch proteins under conditions
that preserve the Gal3p-Gal80p-Gal4p stoichiometries required for normal switch
function. Cells carrying pMEGA2 show 15- to 20-fold more Gal4p and 30- to 40-fold
more Gal3p and Gal80p than cells lacking pMEGA2. These high levels of Gal4p,
Gal80p, and Gal3p do not perturb the integrity of galactose-inducible regulation.
Cells that carry pMEGA2 exhibit normal galactose-induction kinetics for the
chromosomal MEL1 gene expression and normal, albeit slower, log-phase growth.
Insertion of the MEL1 gene into pMEGA2 provides a 24- to 30-fold increase in the
Mel1 protein. Cells carrying a 2-microm-based URA3-selectable plasmid containing
a GAL1pro:lacZ reporter gene and a second plasmid, pMEGA2-DeltaURA3, produce 12
fold more beta-galactosidase than cells carrying only the GAL1pro:lacZ reporter
plasmid. The performance of the MEGA plasmids in providing amplified production
of the Gal3, Gal80, and Gal4 proteins should prove useful in investigations of
the mechanistic aspects of these transcription switch proteins and in work aimed
at achieving high-level, galactose-regulatable production of proteins in yeast.
PMID- 10686152
TI - Expression, purification, and characterization of human recombinant
thrombopoietin in Chinese hamster ovary cells.
AB - Thrombopoietin (TPO) is a primary regulator of megakaryocytopoiesis, a process
through which megakaryocytes proliferate and mature into platelets. Recombinant
human TPO (rhTPO) was expressed in Chinese hamster ovary (CHO) cells and purified
from the culture medium. The cDNA encoding full-length TPO, including the native
signal peptide sequence, was amplified by PCR from a human fetal liver cDNA
library. The product was cloned into a mammalian expression vector under the
control of the SV40 early promoter and enhancer. Secreted rhTPO was purified in
three conventional chromatography steps. It migrates on SDS-PAGE as a broad band,
characteristic of a heavily glycosylated protein, with an average molecular mass
of 85 kDa. rhTPO expressed in CHO cells is biologically active in vitro as
demonstrated by its ability to stimulate the proliferation of a megakaryocytic
cell line and to trigger the JAK/STAT signal transduction pathway. rhTPO also
shows activity in vivo as judged by the elevation of platelet count in treated
mice.
PMID- 10686153
TI - Expression of functional recombinant antibody molecules in insect cell expression
systems.
AB - Recombinant single-chain variable-fragment molecules (scFv) were constructed from
a cell line expressing a monoclonal antibody against African cassava mosaic virus
(ACMV) and expressed in Escherichia coli. DNA sequences that encoded the scFv
were manipulated to allow scFv expression in insect cell lines. A recombinant
baculovirus containing the scFv cDNA was constructed and large amounts of scFv
were produced in each of three insect cell lines infected with the baculovirus.
However, the scFv were not secreted into the medium by any of the cell lines
despite the scFv having been linked to a honeybee melittin leader sequence. The
same scFv cDNA construct was introduced into Drosophila DS2 cells and a stable
recombinant cell line was obtained that produced scFv that was secreted into the
medium. Culture medium containing the scFv was used directly in enzyme-linked
immunosorbent assay (ELISA) tests to detect ACMV in plant tissues. Another
construct that encoded the Ckappa domain of human IgG was fused to the C-terminus
of the scFv that was produced and expressed in Drosophila cells. This scFv
derivative also accumulated in the medium and was more active in ELISA than scFv
lacking the Ckappa domain.
PMID- 10686154
TI - Purification of myelin basic protein from bovine brain.
AB - Myelin basic protein (MBP) is a commonly used substrate for in vitro
determination of numerous protein kinase activities. Herein we describe a rapid
method for isolating relatively large amounts of MBP from bovine brain with a
purity greater than that currently available from commercial sources. Lipids were
first extracted from the CNS tissue by homogenization in sec-butanol. Washes
under neutral and mildly basic conditions were employed to remove neutral and
acidic proteins from the defatted residue. MBP was subsequently extracted under
acidic conditions and further purified by chromatography on CM Sephadex C-25.
Potential contaminating enzyme activities were destroyed by heart treatment. This
method typically yields a recovery of 1.0-1.5 mg MBP per gram of starting
material with a purity of greater than 95%. The MBP prepared in this manner was
suitable for determination of kinase activities by both solution and the "in gel"
kinase assay systems.
PMID- 10686155
TI - Reconstitution of bacterial expressed human CD94: the importance of the stem
region for dimer formation.
AB - Human CD94 is a subunit of the disulfide-linked, heterodimeric natural killer
(NK) cell surface receptor CD94/NKG2. This receptor, a member of the C-type
lectin superfamily, participates in regulating NK cell directed lysis through
interaction with the major histocompatibility antigen HLA-E. Two forms of CD94
were expressed using a bacterial expression system and refolded in vitro. One
form, residues 34-179, designated S34, corresponds to the entire extracellular
region of the receptor, including a 23-residue stem region, and the other,
residues 51-179, designated E51, corresponds only to the putative carbohydrate
recognition domain of the receptor. The refolded full-length S34 protein existed
as a noncovalent dimer initially but formed an interchain disulfide bond upon
storage for several months. In contrast, the stemless construct, E51, existed
largely as a monomeric form. The stem region of S34, residues 34-56, is sensitive
to proteolysis and its absence results in dissociation of the dimer. This
suggests that the residues in the stem region of CD94 help to stabilize the
dimeric conformation.
PMID- 10686156
TI - Staphylococcal protein A as a fusion partner directs secretion of the e1alpha and
e1beta subunits of pea mitochondrial pyruvate dehydrogenase by Bacillus subtilis.
AB - Staphylococcal protein A (SPA)-based vectors were constructed to direct secretion
of the E1alpha and E1beta subunits of Pisum sativum mitochondrial pyruvate
dehydrogenase from Bacillus subtilis. These proteins were not exported when the
signal peptide from levansucrase (SacBSP) was fused to their N-termini. Both
SacBSP-E1alpha and SacBSP-E1beta fusion proteins were insoluble in the cytoplasm.
However, when the SPA open-reading frame was inserted between SacBSP and E1alpha
or E1beta, corresponding fusion proteins were secreted from the cells. The first
(E) IgG-binding domain of SPA was sufficient to direct low level secretion of
both fusion proteins (SacBSP-E-E1alpha and SacBSP-E-E1beta). Adding the second
(D) IgG-binding domain improved extracellular protein yields 3- to 4-fold over E
alone, but was not as efficient as secretion of the full-length (EDABC) SPA
fusion proteins. All constructs were based on the pUB110-derived multicopy
plasmid pWB705. Separate B. subtilis strains transformed with SacBSP-E-E1alpha
His(6) or SacBSP-E1beta were cocultivated in the presence of Ni-NTA agarose. The
native pyruvate dehydrogenase alpha2beta2 structure was bound to the affinity
matrix, demonstrating assembly after secretion. The use of SPA as a fusion
partner during expression of heterologous proteins by B. subtilis provides the
basis of a versatile system that can be used to study both secretion and
protein:protein interactions.
PMID- 10686157
TI - Trophic Cascades in Terrestrial Systems: A Review of the Effects of Carnivore
Removals on Plants.
AB - We present a quantitative synthesis of trophic cascades in terrestrial systems
using data from 41 studies, reporting 60 independent tests. The studies covered a
wide range of taxa in various terrestrial systems with varying degrees of species
diversity. We quantified the average magnitude of direct effects of carnivores on
herbivore prey and indirect effects of carnivores on plants. We examined how the
effect magnitudes varied with type of carnivores in the study system, food web
diversity, and experimental protocol. A metaanalysis of the data revealed that
trophic cascades were common among the studies. Exceptions to this general trend
did arise. In some cases, trophic cascades were expected not to occur, and they
did not. In other cases, the direct effects of carnivores on herbivores were
stronger than the indirect effects of carnivores on plants, indicating that top
down effects attenuated. Top-down effects usually attenuated whenever plants
contained antiherbivore defenses or when herbivore species diversity was high.
Conclusions about the strength of top-down effects of carnivores varied with the
type of carnivore and with the plant-response variable measured. Vertebrate
carnivores generally had stronger effects than invertebrate carnivores.
Carnivores, in general, had stronger effects when the response was measured as
plant damage rather than as plant biomass or plant reproductive output. We
caution, therefore, that conclusions about the strength of top-down effects could
be an artifact of the plant-response variable measured. We also found that
mesocosm experiments generally had weaker effect magnitudes than open-plot field
experiments or observational experiments. Trophic cascades in terrestrial
systems, although not a universal phenomenon, are a consistent response
throughout the published studies reviewed here. Our analysis thus suggests that
they occur more frequently in terrestrial systems than currently believed.
Moreover, the mechanisms and strengths of top-down effects of carnivores are
equivalent to those found in other types of systems (e.g., aquatic environments).
PMID- 10686158
TI - The Effects of a Bottleneck on Inbreeding Depression and the Genetic Load.
AB - We study the effects of a population bottleneck on the inbreeding depression and
genetic load caused by deleterious mutations in an outcrossing population. The
calculations assume that loci have multiplicative fitness effects and that
linkage disequilibrium is negligible. Inbreeding depression decreases immediately
after a sudden reduction of population size, but the drop is at most only several
percentage points, even for severe bottlenecks. Highly recessive mutations
experience a purging process that causes inbreeding depression to decline for a
number of additional generations. On the basis of available parameter estimates,
the absolute fall in inbreeding depression may often be only a few percentage
points for bottlenecks of 10 or more individuals. With a very high lethal
mutation rate and a very slow population growth, however, the decline may be on
the order of 25%. We examine when purging might favor a switch from outbreeding
to selfing and find it occurs only under very limited conditions unless
population growth is very slow. In contrast to inbreeding depression, a
bottleneck causes an immediate increase in the genetic load. Purging causes the
load to decline and then overshoot its equilibrium value. The changes are
typically modest: the absolute increase in the total genetic load will be at most
a few percentage points for bottlenecks of size 10 or more unless the lethal
mutation rate is very high and the population growth rate very slow.
PMID- 10686159
TI - Seed Germination in Desert Annuals: An Empirical Test of Adaptive Bet Hedging.
AB - Temporal variability in survivorship and reproduction is predicted to affect the
evolution of life-history characters. Desert annual plants experience temporal
variation in reproductive success that is largely caused by precipitation
variability. We studied several populations of the desert annual Plantago
insularis along a precipitation gradient. Whereas models of bet hedging in
unpredictable environments generally predict one optimal germination fraction for
a population, empirical studies have shown that environmental conditions during
germination can cause a range of germination fractions to be expressed. In a 4-yr
field study, we found that populations in historically more xeric environments
had lower mean germination fractions, as is predicted by bet-hedging models.
However, populations exhibited significant variation in germination among years.
Two experimental studies measuring germination under several environment
conditions were conducted to elucidate the source of this in situ variation.
Germination fractions exhibited phenotypic plasticity in response to water
availability and date within the season. Populations differed in their norms of
reaction such that seeds from more xeric populations germinated under less
restrictive conditions. A pattern of delayed germination consistent with among
year bet-hedging predictions arose in the field through the interaction of seed
germinability and the distribution of environmental conditions during
germination.
PMID- 10686160
TI - Resource Allocation and the Evolution of Self-Fertilization in Plants.
AB - This article develops a simple evolutionarily stable strategy (ESS) model of
resource allocation in partially selfing plants, which incorporates reproductive
and sex allocation into a single framework. The analysis shows that, if female
fitness gain increases linearly with resource investment, total reproductive
allocation is not affected by sex allocation, defined as the fraction of
reproductive resources allocated to male function. All else being equal, the ESS
total reproductive allocation increases with increasing selfing rate if the
fitness of selfed progeny is more than half that of outcrossed progeny, while the
ESS sex allocation is always a decreasing function of the selfing rate. Self
fertilization is much more common in annual than in perennial plants, and this
association has been commonly interpreted in terms of an effect of life history
on mating system. The model in this article shows that self-fertilization can
itself cause the evolution of the annual habit. Incorporating the effects of
pollen discounting may not have any influence on total reproductive allocation if
female fitness gain is a linear function of resource investment, although the
evolutionarily stable sex allocation is altered. Evolution of the selfing rate is
found to be independent of reproductive and sex allocation under the mass-action
assumption that self- and outcross pollen are deposited simultaneously on
receptive stigmas and compete for access to ovules.
PMID- 10686161
TI - Effects of Enrichment on Three-Level Food Chains with Omnivory.
AB - Although omnivory (the consumption of resources from more than one trophic level)
is widespread, this fundamental limitation to the applicability of food chain
theory to real communities has received only limited treatment. We investigated
effects of enrichment (increasing carrying capacity, K, of the resource) on a
system consisting of a resource (R), an intermediate consumer (N), and an
omnivore (P) using a general mathematical model and tested the relevance of some
of its predictions to a laboratory system of mixed bacteria (=R) and the ciliates
Tetrahymena (=N) and Blepharisma (=P). The model produced six major predictions.
First, N may facilitate or inhibit P. Enrichment may revert the net effect of N
on P from facilitation to inhibition. Second, along a gradient of K, up to four
regions of invasibility and stable coexistence of N and P may exist. At the
lowest K, only R is present. At somewhat higher K, N can coexist with R. At
intermediate K, either N and P coexist, or either consumer excludes the other
depending on initial conditions. At the highest K, N may be excluded through
apparent competition and only R and P can coexist. The pattern of persistence of
Tetrahymena and Blepharisma along an enrichment gradient conformed fairly well to
the scenario allowing coexistence at intermediate K. Third, for stable equilibria
of the omnivory system, R always increases and N always decreases with K. The
abundances of bacteria and Tetrahymena were suggestive of such a pattern but did
not allow a strict test because coexistence occurred at only one level of
enrichment. Fourth, an omnivore can invade an R-N system at a lower K than an
otherwise identical specialist predator of N. Fifth, an omnivore can always
invade a food chain with such a specialist predator. Sixth, over ranges of K
where both omnivory systems and otherwise identical three-level food chains are
feasible, N is always less abundant in the omnivory system, whereas the relative
abundances of R and P in omnivory systems compared to food chains may change with
K. It is thus possible that total community biomass at a given K is lower in an
omnivory system than in a food chain. Both the model and the experimental results
caution that patterns of trophic-level abundances in response to enrichment
predicted by food chain theory are not to be expected in systems with significant
omnivory.
PMID- 10686162
TI - Dwarfs and Giants: Cannibalism and Competition in Size-Structured Populations.
AB - Cannibals and their victims often share common resources and thus potentially
compete. Smaller individuals are often competitively superior to larger ones
because of size-dependent scaling of foraging and metabolic rates, while larger
ones may use cannibalism to counter this competition. We study the interplay
between cannibalism and competition using a size-structured population model in
which all individuals consume a shared resource but in which larger ones may
cannibalize smaller conspecifics. In this model, intercohort competition causes
single-cohort cycles when cannibalism is absent. Moderate levels of cannibalism
reduce intercohort competition, enabling coexistence of many cohorts. More
voracious cannibalism, in combination with competition, produces large-amplitude
cycles and a bimodal population size distribution with many small and few giant
individuals. These coexisting ''dwarfs'' and ''giants'' have very different life
histories, resulting from a reversal in importance of cannibalism and
competition. The population structure at time of birth determines whether
individuals suffer severe cannibalism, with the few survivors reaching giant
sizes, or whether they suffer intense intracohort competition, with all
individuals remaining small. These model results agree remarkably well with
empirical data on perch population dynamics. We argue that the induction of
cannibalistic giants in piscivorous fish is a population-dynamic emergent
phenomenon that requires a combination of size-dependent cannibalism and
competition.
PMID- 10686163
TI - Trophic Interactions during Primary Succession: Herbivores Slow a Plant
Reinvasion at Mount St. Helens.
AB - Lupines (Lupinus lepidus var. lobbii), the earliest plant colonists of primary
successional habitats at Mount St. Helens, were expected to strongly affect
successional trajectories through facilitative effects. However, their effects
remain localized because initially high rates of reinvasive spread were short
lived, despite widespread habitat availability. We experimentally tested whether
insect herbivores, by reducing plant growth and fecundity at the edge of the
expanding lupine population, could curtail the rate of reinvasion and whether
those herbivores had comparable impacts in the older, more successionally
advanced core region. We found that removing insect herbivores increased both the
areal growth of individual lupine plants and the production of new plants in the
edge region, thereby accelerating the lupine's intrinsic rate of increase at the
front of the lupine reinvasion. We found no such impacts of herbivory in the core
region, where low plant quality or a complex of recently arrived natural enemies
may hold herbivores in check. In the context of invasion theory, herbivore
mediated decreases in lupine population growth rate in the edge region translate
into decreased rates of lupine spread, which we quantify here using diffusion
models. In the Mount St. Helens system, decreased rate of lupine reinvasion will
result in reductions in rates of soil formation, nitrogen input, and entrapment
of seeds and detritus that are likely to postpone or alter trajectories of
primary succession. If the type of spatial subtleties in herbivore effects we
found here are common, with herbivory focused on the edge of an expanding plant
population and suppressed or ineffective in the larger, denser central region
(where the plants might be more readily noticed and studied), then insect
herbivores may have stronger impacts on the dynamics of primary succession and
plant invasions than previously recognized.
PMID- 10686164
TI - Population Dynamic and Genetic Consequences of Spatial Density-Dependent
Dispersal in Patchy Populations.
AB - Predictions about sex-specific, spatial density-dependent dispersal and their
demographic and genetic consequences were tested in experimental populations of
root voles (Microtus oeconomus). Each population consisted of two demes
inhabiting equal-sized habitat patches imbedded in a barren matrix area. We used
a neutral two-allele allozyme marker to monitor gene flow. Initially, the two
demes were genetically distinct and had different densities so that the size of a
high-density deme (genotype bb) was four times larger than that of a low-density
deme (genotype aa). The sex-specific dispersal pattern was in accordance with our
prediction. Male dispersal was unconditional on deme-specific densities, and the
majority of the first-generation males became dispersed from both demes, whereas
female dispersal was strongly density dependent, so that dispersal took place
exclusively from the high-density to the low-density deme. The demographic
implication of this dispersal pattern was that the initial density difference
between the demes was quickly canceled out. We built a mathematical model that
predicted that the initially rare allele (a) would increase in frequency given
the dispersal pattern, and this was supported by our experimental data. This
result relies mostly on the density-independent male-dispersal strategy, which
presumably stems from inbreeding avoidance. Our study highlights the importance
of incorporating sex-specific dispersal strategies in population genetic models.
Sex-biased dispersal may act as a deterministic force counteracting the tendency
for stochastic loss of alleles in small and fragmented populations.
PMID- 10686165
TI - Grazers and Diggers: Exploitation Competition and Coexistence among Foragers with
Different Feeding Strategies on a Single Resource.
AB - A mathematical model is presented that describes a system where two consumer
species compete exploitatively for a single renewable resource. The resource is
distributed in a patchy but homogeneous environment; that is, all patches are
intrinsically identical. The two consumer species are referred to as diggers and
grazers, where diggers deplete the resource within a patch to lower densities
than grazers. We show that the two distinct feeding strategies can produce a
heterogeneous resource distribution that enables their coexistence. Coexistence
requires that grazers must either move faster than diggers between patches or
convert the resources to population growth much more efficiently than diggers.
The model shows that the functional form of resource renewal within a patch is
also important for coexistence. These results contrast with theory that considers
exploitation competition for a single resource when the resource is assumed to be
well mixed throughout the system.
PMID- 10686166
TI - Energy, Density, and Constraints to Species Richness: Ant Assemblages along a
Productivity Gradient.
AB - Species richness describes the number of species of a given taxon in a given time
and space. The energy limitation hypothesis links the species richness of
consumer taxa to net primary productivity (NPP) through two relationships: NPP
limits a taxon's density, and taxon density limits species richness. We study
both relationships with a survey of 15 ground ant assemblages, along a
productivity gradient from deserts to rain forests. Ant density (colonies m-2)
was a positive, decelerating function of net aboveground productivity (NAP). A
stepwise regression suggests that the efficiency with which NAP is converted to
ant colonies increases with maximum summer temperature and decreases with
precipitation. Ant species richness was a positive decelerating function of
density at three spatial scales. This supports the energy limitation hypothesis'
assumption that average population densities are higher in environments that are
more productive. These two nonlinear functions (NAP-density and density-species
richness) combine to create, at a variety of scales, positive, decelerating,
productivity-diversity curves for a common, ecologically dominant taxon across
the terrestrial productivity gradient. However, variance in the density and
diversity explained by NAP decreases with scale, suggesting that energy
limitation of diversity predominates at small spatial scales (<1 ha).
PMID- 10686167
TI - Nonlinear Dynamics and the Evolution of Semelparous and Iteroparous Reproductive
Strategies.
PMID- 10686168
TI - Unravelling the pathophysiology of calcium channel mutations causing neurological
disorders.
PMID- 10686169
TI - Tourette syndrome, associated conditions and the complexities of treatment.
AB - Tourette syndrome (TS) is characterized by multiple motor tics plus one or more
vocal (phonic) tics, which characteristically wax and wane. It can no longer be
considered the rare and bizarre syndrome that it was once thought to be. The
concepts surrounding TS, and our understanding of it, are also becoming
increasingly complex and, in some individuals, TS is now recognized to be
associated with a wide variety of associated behaviours and psychopathologies. It
is suggested that TS is heterogeneous from a variety of standpoints including
clinical presentation and psychopathology, and thus neuropharmacological
responses and possibly even aetiological and genetic mechanisms. In this paper,
mention is made of recent findings in epidemiology and genetics, highlighting the
complexities of the disorder; these have been chosen because findings in both
areas have clinical and management implications. The literature on the clinical
manifestations, associated behaviours, psychopathology (and/or comorbid
conditions) and management, in particular, is reviewed in detail.
PMID- 10686170
TI - Abnormal transmitter release at neuromuscular junctions of mice carrying the
tottering alpha(1A) Ca(2+) channel mutation.
AB - Neurotransmitter release at many synapses is regulated by P/Q-type Ca(2+)
channels containing the alpha(1A) pore-forming subunit. Mutations in alpha(1A)
cause cerebral disorders including familial hemiplegic migraine (FHM) and ataxia
in humans. Tottering (tg) alpha(1A) mutant mice display ataxia and epilepsy. It
is not known whether alpha(1A) mutations induce impairment of synaptic function,
which could underlie the symptoms of these cerebral disorders. To assess whether
alpha(1A) mutations influence neurotransmitter release, we studied P-type Ca(2+)
channel-mediated acetylcholine (ACh) release at tg neuromuscular junctions (NMJs)
with micro-electrode measurements of synaptic potentials. We found a Ca(2+)-,
Mg(2+)- and K(+)-dependent increase of spontaneous ACh release at both homo- and
heterozygote tg NMJs. Furthermore, there was increased run-down of high-rate
evoked release at homozygous tg NMJs. In isotonic contraction experiments this
led to block of synaptic transmission at lower concentrations of the ACh
antagonist tubocurarine than were needed in wild-type muscles. Our results
suggest that in tg motor nerve terminals there is increased influx of Ca(2+)
under resting conditions. This study shows that functional consequences of
alpha(1A) mutations causing cerebral disorders can be characterized at the NMJ.
PMID- 10686171
TI - Accelerated forgetting in patients with epilepsy: evidence for an impairment in
memory consolidation.
AB - Patients with epilepsy frequently complain of memory difficulties yet perform
normally on standard neuropsychological tests of memory. It has been suggested
that this may be due to an impairment of very long-term memory consolidation
processes, beyond those normally assessed in the neuropsychological clinic. We
carried out a prospective study of verbal memory over a long-term retention
interval of 8 weeks in patients with epilepsy and in controls. Results were
compared with performance on conventional tests of memory. Despite normal
learning and retention over 30 min, patients with epileptic foci in the left
temporal lobe performed disproportionately poorly on the long-term test compared
with both patients with epileptic foci in the right temporal lobe and controls.
Our findings provide evidence for an extended period of memory consolidation and
point to the critical region for this process, at least for verbal material, in
the left temporal lobe. The implications of our findings for clinical assessment
and therapeutic management of patients with epilepsy are discussed.
PMID- 10686172
TI - Atypical and typical presentations of Alzheimer's disease: a clinical,
neuropsychological, neuroimaging and pathological study of 13 cases.
AB - There has been increasing awareness that some slowly progressive focal cortical
syndromes can be the presenting features of Alzheimer's disease, but pathological
evidence has been sparse. This clinico-pathological series presents our
experience with pathologically proven atypical as well as typical Alzheimer's
disease presentations. We report and compare four patterns of presentation: a
typical pattern with initial amnesic syndrome (n = 4 cases), progressive visual
dysfunction (n = 1), progressive biparietal syndrome (n = 2) and progressive
aphasia (n = 6). The aphasic presentations include both fluent and non-fluent
aphasic syndromes. The neuropsychological profiles and neuroimaging clearly
reflect the presenting clinical features, and show a close relationship to the
distribution of pathology in these cases. Of note was the sparing of medial
temporal structures (hippocampus and/or entorhinal cortex) in several aphasic
cases and the severe occipito-parietal involvement in those with prominent
visuospatial disorders at presentation. Our data demonstrate the wide spectrum of
Alzheimer's disease presentations. The recognition of atypical presentations of
Alzheimer's disease is important when attempting to make an early accurate pre
morbid diagnosis of neurodegenerative disease.
PMID- 10686173
TI - Developmental amnesia associated with early hypoxic-ischaemic injury.
AB - We recently reported on three young patients with severe impairments of episodic
memory resulting from brain injury sustained early in life. These findings have
led us to hypothesize that such impairments might be a previously unrecognized
consequence of perinatal hypoxic-ischaemic injury. Neuropsychological and
quantitative magnetic resonance investigations were carried out on five young
patients, all of whom had suffered hypoxic-ischaemic episodes at or shortly after
birth. All five patients showed severe impairments of episodic memory (memory for
events), with relative preservation of semantic memory (memory for facts).
However, none had any of the major neurological deficits that are typically
associated with hypoxic-ischaemic injury, and all attended mainstream schools.
Quantitative magnetic resonance investigations revealed severe bilateral
hippocampal atrophy in all cases. As a group, the patients also showed bilateral
reductions in grey matter in the regions of the putamen and the ventral part of
the thalamus. On the basis of their clinical histories and the pattern of
magnetic resonance findings, we attribute the patients' pathology and associated
memory impairments primarily to hypoxic-ischaemic episodes sustained very early
in life. We suggest that the degree of hypoxia-ischaemia was sufficient to
produce selective damage to particularly vulnerable regions of the brain, notably
the hippocampi, but was not sufficient to result in the more severe neurological
and cognitive deficits that can follow hypoxic-ischaemic injury. The impairments
in episodic memory may be difficult to recognize, particularly in early
childhood, but this developmental amnesia can have debilitating consequences,
both at home and at school, and may preclude independent life in adulthood.
PMID- 10686174
TI - Repertoire dynamics of autoreactive T cells in multiple sclerosis patients and
healthy subjects: epitope spreading versus clonal persistence.
AB - Autoantigen-specific T-lymphocytes are present in patients with autoimmune
disease and in normal subjects. Little is currently known about the temporal
variation (dynamics) of the immune repertoire of these autoreactive T cells. We
analysed the long-term variation of the immune repertoire of T cells specific for
myelin basic protein (MBP) in five untreated patients with multiple sclerosis and
four normal control subjects over a mean observation period of 6 years. MBP
specific CD4(+) T-cell lines were selected with purified human MBP, and their
epitope specificity was mapped with overlapping synthetic peptides. Three
distinct patterns of repertoire development were observed. (i) Two patients and
three control subjects maintained a broad epitope response with fluctuations over
time. (ii) Two patients initially showed a focused response that broadened over
the course of 6 years; this finding could be described as intramolecular epitope
spreading. (iii) In one patient and one control subject, a strikingly focused
response, which was directed to a cluster of nested epitopes in the MBP region 83
102, persisted over time. T-cell receptor Vbeta sequence analysis allowed us to
trace individual clones of MBP-specific T cells for up to 7 years in the
peripheral circulation in four of the five patients and three of the four
controls, suggesting that the long-term persistence of MBP-specific T-cell clones
is a common feature of the T-cell repertoire not unique to multiple sclerosis.
The persisting MBP-specific T-cell clones were not detectable in the blood of one
of the patients by complementarity-determining region (CDR)-3 spectratyping,
indicating that their frequency does not exceed 1 in 5000 T cells. The temporal
characteristics of the MBP-specific T-cell repertoire described here are relevant
to therapeutic strategies targeting autoantigen-specific T cells in multiple
sclerosis and other autoimmune diseases.
PMID- 10686176
TI - The neural correlates of 'deaf-hearing' in man: conscious sensory awareness
enabled by attentional modulation.
AB - Attentional modulation of normal sensory processing has a two-fold impact on
human brain activity: activation of a network of localized brain regions is
associated with paying attention, and activation of specific sensory regions is
enhanced relative to passive stimulation. The mechanisms underlying attentional
modulation of perception in patients with lesions of sensory cortices are less
well understood. Here we report a unique patient suffering from extensive
bilateral destruction of the auditory cortices (including the primary auditory
fields) who demonstrated conscious perception of the onset and offset of sounds
only when selectively attending to the auditory modality. This is the first
description of such an attentively modulated 'deaf-hearing' phenomenon and its
neural correlates, using H(2)(15)O-PET. Increases in cerebral blood flow
associated with conscious awareness of sound that was achieved by listening
attentively (compared with identical auditory stimulation presented when the
patient was inattentive) were found bilaterally in the lateral (pre)frontal
cortices, the spared middle temporal cortices and the cerebellar hemispheres. We
conclude that conscious awareness of sounds may be achieved in the absence of the
primary auditory cortex, and that selective, 'top-down' attention, associated
with prefrontal systems, exerts a crucial modulatory effect on auditory
perception within the remaining auditory system.
PMID- 10686175
TI - Axonal loss results in spinal cord atrophy, electrophysiological abnormalities
and neurological deficits following demyelination in a chronic inflammatory model
of multiple sclerosis.
AB - Recent pathological studies have re-emphasized that axonal injury is present in
patients with multiple sclerosis, the most common demyelinating disease of the
CNS in humans. However, the temporal profile of demyelination and axonal loss in
multiple sclerosis patients and their independent contributions to clinical and
electrophysiological abnormalities are not completely understood. In this study,
we used the Theiler's murine encephalomyelitis virus model of progressive CNS
inflammatory demyelination to demonstrate that demyelination in the spinal cord
is followed by a loss of medium to large myelinated fibres. By measuring spinal
cord areas, motor-evoked potentials, and motor coordination and balance, we
determined that axonal loss following demyelination was associated with
electrophysiological abnormalities and correlated strongly with reduced motor
coordination and spinal cord atrophy. These findings demonstrate that axonal loss
can follow primary, immune-mediated demyelination in the CNS and that the
severity of axonal loss correlates almost perfectly with the degree of spinal
cord atrophy and neurological deficits.
PMID- 10686177
TI - Receptive amusia: evidence for cross-hemispheric neural networks underlying music
processing strategies.
AB - Perceptual musical functions were investigated in patients suffering from
unilateral cerebrovascular cortical lesions. Using MIDI (Musical Instrument
Digital Interface) technique, a standardized short test battery was established
that covers local (analytical) as well as global perceptual mechanisms. These
represent the principal cognitive strategies in melodic and temporal musical
information processing (local, interval and rhythm; global, contour and metre).
Of the participating brain-damaged patients, a total of 69% presented with post
lesional impairments in music perception. Left-hemisphere-damaged patients showed
significant deficits in the discrimination of local as well as global structures
in both melodic and temporal information processing. Right-hemisphere-damaged
patients also revealed an overall impairment of music perception, reaching
significance in the temporal conditions. Detailed analysis outlined a
hierarchical organization, with an initial right-hemisphere recognition of
contour and metre followed by identification of interval and rhythm via left
hemisphere subsystems. Patterns of dissociated and associated melodic and
temporal deficits indicate autonomous, yet partially integrated neural subsystems
underlying the processing of melodic and temporal stimuli. In conclusion, these
data contradict a strong hemispheric specificity for music perception, but
indicate cross-hemisphere, fragmented neural substrates underlying local and
global musical information processing in the melodic and temporal dimensions. Due
to the diverse profiles of neuropsychological deficits revealed in earlier
investigations as well as in this study, individual aspects of musicality and
musical behaviour very likely contribute to the definite formation of these
widely distributed neural networks.
PMID- 10686178
TI - Encoding of burning pain from capsaicin-treated human skin in two categories of
unmyelinated nerve fibres.
AB - Burning pain was induced in healthy human subjects by intracutaneous injections
of capsaicin (20 microl, 0.1%) in the innervation territory of the cutaneous
branch of the peroneal nerve and the pain responses were compared with the
activation patterns of afferent C-fibres recorded by microneurography.
Responsiveness of single units to mechanical or heat stimuli or to sympathetic
reflex provocation tests was determined by transient slowing of conduction
velocity following activation (marking technique). Capsaicin activated each of 12
mechano-responsive and 17 of 20 mechano-insensitive C-units. However, the
duration of the responses to capsaicin was significantly longer in mechano
insensitive C-units (median 170 s; quartiles 80-390) compared with mechano
responsive C-units (8 s; 4-10). The activation times of mechano-insensitive C
units closely matched the duration of capsaicin-induced pain responses, whereas
activation of mechano-responsive C-units was too short to account for the
duration of the burning pain. The latter generally were desensitized to
mechanical stimulation at the injection site, whereas 8 of 17 of the originally
mechano-insensitive C-units became responsive to mechanical probing at the
injection site after capsaicin. Responses typically started several seconds after
the onset of the mechanical stimulus in parallel with pain sensations. We did not
observe sensitization to brushing or to punctate stimuli in uninjured parts of
the innervation territory. Differential capsaicin sensitivity adds to the
cumulating evidence for the existence of two categories of functionally different
nociceptors in human skin, with a special role for mechano-insensitive fibres in
sensitization and hyperalgesia. Possible structural differences between these two
categories are discussed, including the role of tetrodotoxin-resistant sodium
channels.
PMID- 10686179
TI - Induction of plasticity in the human motor cortex by paired associative
stimulation.
AB - Current models of motor cortical plasticity, developed in studies on experimental
animals, emphasize the importance of the conjoint activity of somatosensory
afferents and intrinsic motor cortical circuits. The hypothesis that an enduring
change in excitability in the cortical output circuitry can be induced in the
human motor cortex by a paired-stimulation protocol was tested. Low-frequency
median nerve stimulation was paired with transcranial magnetic stimulation (TMS)
over the optimal cranial site for stimulating the abductor pollicis brevis muscle
(APB). This protocol induced an increase in the amplitudes of the motor evoked
potentials (MEPs) in the resting APB as well as a prolongation of the silent
period measured in the precontracted APB following TMS; amplitudes of MEPs
measured in voluntary contraction remained unchanged. Experiments testing the
excitability of spinal motoneurons using F-wave studies and electrical
stimulation of the brainstem suggested that the site of the plastic changes was
within the motor cortex. The increases in resting amplitudes and silent period
duration were conditionally dependent on the timing between the afferent and the
magnetic stimulation in that they were present when events elicited by afferent
and magnetic stimulation were synchronous at the level of the motor cortex.
Plasticity induced by paired stimulation evolved rapidly (within 30 min), was
persistent (minimum duration 30-60 min) yet reversible, and was topographically
specific. This combination of features and the similarity to properties of
induced enduring changes in synaptic efficacy, as elucidated in animal studies,
leads us to propose that the induced plasticity may represent a signature of
associative long-term potentiation of cortical synapses or closely related
neuronal mechanisms in the human cortex.
PMID- 10686180
TI - The impact of apolipoprotein E genotypes on age at onset of symptoms and
phenotypic expression in Wilson's disease.
AB - Wilson's disease is a disorder of biliary copper excretion that may result in
severe neurological symptoms and advanced liver disease. The wide variation of
phenotypic disease expression cannot be fully explained by the different
mutations of the Wilson disease gene. In neurological disorders, such as
Alzheimer's disease, temporal lobe epilepsy and cerebral trauma, the presence of
the apolipoprotein E (ApoE) allele epsilon4 is associated with an increased
vulnerability of the brain to the effects of the disease, whereas the presence of
the ApoE genotype epsilon3/3 appears to provide moderate neuroprotection. We
examined whether this hypothesis holds true for the development of neurological
symptoms in patients with Wilson's disease. The ApoE genotype and the H1069Q
mutation (the most common in Wilson's disease) status were determined by
polymerase chain reaction-based mutation assays in 121 well-characterized,
symptomatic index patients with Wilson's disease. An investigation profile was
established in which the patients were grouped according to the clinical symptoms
at presentation, the ApoE genotypes and the status of the H1069Q mutation. Fifty
nine per cent of the 121 patients had the allele combination ApoE epsilon3/3 (21%
ApoE epsilon3/4, 19% ApoE epsilon3/2, 1% ApoE epsilon4/2). The distribution of
ApoE genotypes did not deviate from known distributions in healthy European
subjects. Within the group of 40 H1069Q-homozygous patients, the onset of
symptoms was significantly delayed in patients with the ApoE epsilon3/3 genotype
(25 +/- 6 years at presentation) compared with patients with the ApoE epsilon3/4
genotype (20 +/- 3 years at presentation). In this study, the ApoE genotype was
established as an important factor delaying the onset of neurological and hepatic
symptoms, but not modifying phenotypic disease expression in a homogeneous group
of patients with Wilson's disease (all H1069Q-homozygotes, similar genetic
background). The presence of ApoE epsilon3/3 attenuates clinical manifestations
in Wilson's disease by mechanisms which might involve the antioxidant and
membrane-stabilizing properties of the ApoE 3 protein.
PMID- 10686181
TI - Cytochrome oxidase immunohistochemistry: clues for genetic mechanisms.
AB - Cytochrome c oxidase (COX) is encoded by three mitochondrial and nine nuclear
genes. COX deficiency is genetically heterogeneous but current diagnostic methods
cannot easily distinguish between mitochondrial and nuclear defects. We
hypothesized that there may be differential expression of COX subunits depending
on the underlying mutation. COX subunit expression was investigated in five
patients with known mtDNA mutations. Severe and selective reduction of mtDNA
encoded COX subunits I and II was consistently observed in all these patients and
was restricted to COX-deficient fibres. Immunostaining of nuclear-encoded
subunits COX IV and Va was normal, whilst subunit VIc, also nuclear-encoded, was
decreased. Twelve of 36 additional patients with histochemically defined COX
deficiency also had this pattern of staining, suggesting that they had mtDNA
defects. Clinical features in this group were heterogeneous, including infantile
encephalopathy, multisystem disease, cardiomyopathy and childhood-onset isolated
myopathy. The remaining patients did not have the same pattern of immunostaining.
Fourteen had reduced staining of all subunits, whilst 10 had normal staining of
all subunits despite reduced enzyme activity. Patients with COX deficiency
secondary to mtDNA mutations have a specific pattern of subunit loss, but the
majority of children with COX deficiency do not have this pattern of subunit loss
and are likely to have nuclear gene defects.
PMID- 10686182
TI - Cytoarchitectonic and immunohistochemical characterization of a specific pain and
temperature relay, the posterior portion of the ventral medial nucleus, in the
human thalamus.
AB - Previous studies in the macaque monkey have identified a thalamic nucleus, the
posterior portion of the ventral medial nucleus (VMpo), as a dedicated lamina I
spinothalamocortical relay for pain and temperature sensation. The dense plexus
of calbindin-immunoreactive fibres that characterizes VMpo in primates enables
its homologue to be identified in the human thalamus by immunohistochemical
labelling for calbindin. We have now analysed in detail the cytoarchitectonic
characteristics of VMpo and its relationship with immunoreactivity for calbindin,
substance P and calcitonin gene-related peptide (CGRP) in the human thalamus. The
area in the posterolateral thalamus in which dense calbindin-immunoreactive fibre
terminations are present coincides nearly completely with a distinct region that
contains small to medium-sized cells with round or oval shapes that are
aggregated in clusters separated by cell sparse areas. This region, which we
identify as VMpo, is located posteromedial to the ventral posterior lateral (VPL)
and ventral posterior medial (VPM) nuclei, ventral to the anterior pulvinar and
centre median nuclei, lateral to the limitans and parafascicular nuclei and
dorsal to the medial geniculate nucleus. Calbindin-immunoreactive fibres enter
VMpo from the spinal lemniscus and form large patches of dense terminal-like
staining over clusters of VMpo neurons. A few of these clusters also display
terminal-like substance P labelling. Small bursts of CGRP staining are
intercalated between the calbindin-labelled clusters, but there is little or no
overlap between these two markers. CGRP immunoreactivity is also present over
small, non-clustered neurons in the calbindin-negative area that separates VMpo
from the VPL and VPM nuclei, which we denote as the posterior nucleus (Po). These
observations provide a concise description of VMpo in the human thalamus.
Further, they suggest that the lamina I spinothalamic tract fibres (represented
by calbindin and probably also substance P immunoreactivity) and vagal-solitary
parabrachial afferents (represented by CGRP immunoreactivity) form closely
related, but separate, termination fields that can be considered to represent
different aspects of enteroceptive information regarding the physiological status
of the tissues and organs of the body. The location of VMpo and the adjacent Po
fits with clinical descriptions of the thalamic area from which pain, temperature
and visceral sensations can be evoked by microstimulation, and where nociceptive
and thermoreceptive neurons have been recorded in humans. It also corresponds to
the area in which infarcts cause analgesia and thermoanaesthesia and can lead to
the paradoxical development of central pain.
PMID- 10686183
TI - Functional MRI evidence for a role of frontal and inferior temporal cortex in
amodal components of priming.
AB - Changes in human brain activity associated with repetition priming during word
generation were characterized across a series of neuroimaging and behavioural
studies. Repetition priming was consistently observed behaviourally as a decrease
in response latency for repeated items, and was found for both visually and
aurally cued word-generation tasks. Brain imaging using whole-brain functional
MRI identified neural correlates of these effects. The principal effect of
priming was to reduce neural activity within regions that were already being used
to perform the word-generation tasks. Repeated word generation in response to
visual cues was correlated with anatomically selective reductions in activity
within the left frontal cortex along the inferior frontal gyrus and inferior
temporal regions and, to a lesser degree, in specific earlier visual regions.
These reductions were reversed when new items were presented, indicating that
they were item-specific. Repeated word generation in response to aural cues also
showed anatomically selective activity reductions within the left frontal and
inferior temporal regions, indicating that these activity reductions were not
dependent on the perceptual modality of the cue. The auditory cortex showed
minimal repetition-related reductions. The presence of activity within left
frontal regions that decreases as a function of item repetition for both visual
and auditory cues suggests that these reductions may underlie an amodal
repetition-priming effect existing at processing stages involving
lexical/semantic search and access. The surprising finding that activity
reductions in the inferior temporal cortex can be linked to repetition of either
visual or auditory cues further suggests that these regions may be modulated in a
top-down fashion during repetition priming, independent of (or in parallel with)
stimulus-driven perceptual processes. Taken collectively, the data converge on a
neural correlate of lexical/semantic priming. Amodal lexical/semantic processes,
which may be triggered initially by modality-specific cues, proceed via an
interaction between frontal and posterior brain regions. These interdependent
regions show activity reductions that correlate with facilitated task performance
when items are repeated.
PMID- 10686184
TI - The natural history of multiple sclerosis: a geographically based study: 8:
familial multiple sclerosis.
AB - We have examined the demographics and long-term outcome of 1044 patients with
sporadic and familial multiple sclerosis in a population-based cohort from
London, Ontario. The mean follow-up was 25 years in duration, and by this time
most patients had reached the unambiguous endpoint scores of the Kurtzke
disability status scale (DSS), DSS 6, 8 or 10. An affected family member was
identified in 19.8% of the total population, and this subgroup was further
divided arbitrarily into the following three groups by the type and number of
relatives affected: (i) first degree only; (ii) first degree plus others; (iii)
second or third degree. The outcome in these groups was compared with that for
those patients who, at a mean 25 year follow-up, had no relatives known to be
affected. Familial cases closely resembled those remaining sporadic in both
demographics and outcome, although onset in the most heavily loaded families was
earlier and male/female ratio was greater. The times to DSS 6, 8 and 10 did not
differ significantly when sporadic, familial and familial subgroups were
compared. These results provide no clinical support for viewing familial multiple
sclerosis as distinct from the sporadic form. The observed recurrence rate for
siblings in a strictly defined epidemiological sample was 3.5%, much as
projected. These results validate the recurrence risks which have previously been
derived from age-corrected data for these first-degree relatives.
PMID- 10686185
TI - Uses of embryo duplication in humans: embryology and ethics.
PMID- 10686186
TI - The welfare of the child: problems of indeterminacy and deontology.
PMID- 10686187
TI - Can GnRH agonists act directly on the ovary and contribute to cyst formation?
PMID- 10686188
TI - The right to choose your donor: a step towards commercialization or a step
towards empowering the patient?
PMID- 10686189
TI - Gamete donation: when does consent become irrevocable?
PMID- 10686190
TI - A double-blind, randomized study to compare recombinant human follicle
stimulating hormone (FSH; Gonal-F) with highly purified urinary FSH (Metrodin)
HP) in women undergoing assisted reproductive techniques including
intracytoplasmic sperm injection. The French Multicentre Trialists.
AB - This prospective, double-blind, randomized, multicentre study compared the
efficacy and safety of recombinant human follicle stimulating hormone (r-hFSH;
Gonal-F((R))) versus highly purified urinary FSH (u-hFSH HP; Metrodin((R)) HP) in
women undergoing ovarian stimulation for in-vitro fertilization, including
intracytoplasmic sperm injection. A total of 278 patients began a long
gonadotrophin-releasing hormone agonist protocol, then 139 received r-hFSH and
139 u-hFSH HP, 150 IU/day administered s.c., for the first 6 days of treatment.
On day 7, the dose was adjusted, if necessary, according to ovarian response.
Human chorionic gonadotrophin (HCG, 10 000 IU, s.c.) was administered once there
was more than one follicle 18 mm in diameter and two others >/=16 mm. Oocyte
retrieval was performed 36-38 h after HCG injection: 128 patients (92%) receiving
r-hFSH and 113 (81%) receiving u-hFSH HP had at least one oocyte retrieved. Among
patients receiving r-hFSH, there was a significantly higher mean (+/- SD) number
of oocytes retrieved (11.0 +/- 5.9 versus 8.8 +/- 4.8 with u-hFSH HP; P = 0. 002)
and mean number of embryos obtained (5.1 +/- 3.7 versus 3.5 +/- 2.9 with u-hFSH
HP; P = 0.0001). With r-hFSH, significantly fewer FSH treatment days (11.7 +/-
1.9 versus 14.5 +/- 3.3) and 75 IU ampoules (27.6 +/- 10.2 versus 40.7 +/- 13.6)
were required than with u-hFSH HP (P = 0.0001). Embryo replacement on day 2-3
after oocyte retrieval resulted in 36 liveborn children in the Gonal-F((R)) group
and 33 in the Metrodin HP((R)) group (not significant). There were seven cases
(5.0%) of ovarian hyperstimulation syndrome in the r-hFSH group and three (2.2%),
in the u-hFSH HP group (not significant). It is concluded that r-hFSH is more
effective than u-hFSH in inducing multiple follicular development.
PMID- 10686191
TI - Ovarian stimulation with HMG: results of a prospective randomized phase III
European study comparing the luteinizing hormone-releasing hormone (LHRH)
antagonist cetrorelix and the LHRH-agonist buserelin. European Cetrorelix Study
Group.
AB - In this prospective and randomized study, 188 patients received the luteinizing
hormone-releasing hormone (LHRH) antagonist cetrorelix, and 85 patients the LHRH
agonist buserelin to prevent endogenous luteinizing hormone (LH) surges during
ovarian stimulation in in-vitro fertilization (IVF)/intracytoplasmic sperm
injection (ICSI) cycles. Ultimately, 181 patients (96.3%) in the cetrorelix
group, and 77 (90.6%) in the buserelin group, reached the day of the human
chorionic gonadotrophin (HCG) injection. The mean number of human menopausal
gonadotrophin (HMG) ampoules administered and the mean number of stimulation days
with HMG were significantly less in the cetrorelix group than in the buserelin
group (P < 0.01). A rise in LH and progesterone concentrations was observed in
three of the 188 patients (1.6%) who received cetrorelix. On the day of the HCG
administration, more follicles of a small diameter (11-14 mm) were observed in
the buserelin group than in the cetrorelix group (P = 0. 02) and the mean serum
oestradiol concentration was significantly higher in patients who received
buserelin than in those who received cetrorelix (P < 0.01). Similar results were
observed in fertilization, cleavage and pregnancy rates in the two groups. In
conclusion, the use of the LHRH antagonists might be considered more advantageous
because of the short-term application needed to inhibit gonadotrophin secretion,
so allowing a reduction in the treatment time in a clinically significant manner.
PMID- 10686192
TI - Peripheral blood concentrations of inhibin B are elevated during gonadotrophin
stimulation in patients who later develop ovarian OHSS and inhibin A
concentrations are elevated after OHSS onset.
AB - Ovarian hyperstimulation syndrome (OHSS) is a serious side-effect of controlled
ovarian stimulation. Inhibin A and inhibin B, as putative predictors of OHSS
development in the same stimulation cycle, were evaluated. A cohort of 428 in
vitro fertilization (IVF) patients was followed. Fifteen patients with severe
OHSS were compared with matched (age, follicle number) controls. Serum samples
were obtained at five time points from the start of ovarian stimulation until >/=
3 days post-embryo transfer and analysed with specific enzyme-linked
immunosorbent assays. Inhibin A in the OHSS group showed a continuous increase
with a significant elevation 3 days prior to oocyte aspiration (ASP-3) and
onwards. Maximal concentrations were detected at embryo transfer and the
concentrations remained high at >/= 3 days post-embryo transfer. Inhibin A
concentrations in the control group showed a transient elevation (significant
increase at ASP and embryo transfer). Inhibin A in the OHSS group was
significantly higher than in controls only at the time point where OHSS had
developed (>/= 3 days post-embryo transfer), and declined during OHSS treatment.
Overall, there was a positive correlation between the number of follicles and
inhibin A concentrations at ASP-3 until embryo transfer in the control group but
not in the OHSS group. The concentrations of inhibin B in both groups increased
from the start of ovarian stimulation, with peak values at ASP-3, and then a
decline. Inhibin B was significantly higher in OHSS patients at ASP-3 and at ASP.
Inhibin B at ASP-3 was correlated with the total number of follicles in both the
OHSS group and the control group.
PMID- 10686193
TI - Predictive value of serum and follicular fluid leptin concentrations during
assisted reproductive cycles in normal women and in women with the polycystic
ovarian syndrome.
AB - Leptin is an adipocyte-derived hormone which plays a central role in the
regulation of body weight and energy homeostasis and in signalling to the brain
that adequate energy stores are available for reproduction. Although leptin may
affect reproduction by regulating the hypothalamic-pituitary-gonadal axis, recent
in-vitro observations indicate that leptin may also have direct intra-ovarian
actions. Leptin concentrations were measured in women who succeeded in becoming
pregnant within three cycles of in-vitro fertilization (IVF) or gamete intra
fallopian transfer (n = 53), in women who failed to become pregnant within three
cycles (n = 50), and in women with polycystic ovarian syndrome (PCOS) (n = 22).
It was found that lower follicular fluid leptin concentrations were a marker of
assisted reproduction treatment success in normal women. Women with PCOS had
higher leptin concentrations than women without such a diagnosis, but this was
due to their higher body mass index (BMI). After adjustment for age and BMI,
women with PCOS who became pregnant tended to have lower mean follicular fluid
leptin concentrations than women with PCOS who did not succeed at becoming
pregnant. Further studies exploiting the strengths of the IVF model are needed to
assess whether the prognostic role for follicular fluid leptin in human
reproduction is independent of other factors, and to elucidate the underlying
mechanisms.
PMID- 10686194
TI - Increased prevalence of thyroid antibodies in euthyroid women with a history of
recurrent in-vitro fertilization failure.
AB - This study was undertaken to evaluate whether the presence of thyroid antibodies
in euthyroid women is associated with an adverse outcome in an in-vitro
fertilization (IVF)-embryo transfer programme. In 24 women (study group: mean age
+/- SD: 31.5 +/- 4.4 years) who failed to conceive after having three or more
cycles of IVF and embryo transfer, serum concentrations of thyroglobulin (TG),
thyroid peroxidase antibodies (TPO) and anticardiolipin antibodies (IgG and IgM)
were measured using commercially available kits. The control group comprised 24
consecutive patients without endocrine dysfunction (mean age +/- SD: 30.3 +/- 4.1
years) seeking infertility treatment in our department of assisted reproduction.
All patients in both the study and the control groups were determined to be
euthyroid by demonstrating normal concentrations of thyroid-stimulating hormone
(TSH). In the study and control groups respectively, 13 and two patients
demonstrated positive titres of TG, TPO or both thyroid antibodies (Fisher's
exact test: P = 0.002). Mean serum concentrations of TG were significantly
increased in the study group compared to the control subjects (156 +/- 167 IU/ml
versus 33.5 +/- 32.0 IU/ml; U-test: P = 0.009). Serum concentrations of TPO and
anticardiolipin antibodies were similar in both groups. Our investigations
revealed that thyroid antibodies might be independent markers for reproductive
failure in an IVF-embryo transfer programme.
PMID- 10686195
TI - Serum concentrations of dimeric inhibins, activin A, gonadotrophins and ovarian
steroids during the menstrual cycle in older women.
AB - The transition from regular ovarian cyclicity to menopause is associated with a
rise in the circulating concentrations of follicle stimulating hormone (FSH),
despite the maintenance of serum oestradiol concentrations during the
perimenopause. The aim of this study was to compare the pattern of secretion of
dimeric inhibins, activin A, gonadotrophins and steroids in regularly cycling
women of 40-50 years with normal and raised early follicular phase serum FSH
concentrations and young women (25-33 years) during the menstrual cycle. Blood
samples were taken prospectively almost daily throughout the menstrual cycle.
Women recruited were classified into three groups: (i) older women with normal
FSH [(ON-FSH), day 3 FSH <8 mIU/ml, n = 10]; (ii) older women with raised FSH [(R
FSH), day 3 FSH >8 mIU/ml, n = 6] and (iii) young normal FSH (YN-FSH) women, age
25-32 years (n = 6). Cyclic patterns of serum inhibins and activin A were similar
in the ON-FSH and YN-FSH groups. The R-FSH group had significantly lower
concentrations of inhibin A prior to the luteinizing hormone (LH) surge and in
the mid-luteal phase and lower concentrations of inhibin B in the early
follicular phase compared with the ON-FSH group. Serum concentrations of activin
A, progesterone and oestradiol were similar in all three groups. It is concluded
from this study that the rise in early follicular phase serum FSH in older women
is associated with a decrease in circulating concentrations of inhibin B in the
early follicular phase. However, lower circulating concentrations of inhibin A in
the luteal phase of the R-FSH group may also contribute to the rise in early
follicular phase FSH concentrations during the menstrual cycle, although further
studies with larger numbers are required to confirm this observation.
PMID- 10686196
TI - Cell proliferation and vascular morphology in the marmoset corpus luteum.
AB - Luteal formation is associated with angiogenesis and low progesterone production.
Maximal mid-luteal phase progesterone production is concurrent with extensive
vascularization, and luteolysis occurs when steroidogenesis decreases. Angiogenic
cell proliferation and vascular changes have not been examined in the marmoset.
The aim of this study was to examine vascular morphology throughout the luteal
phase by identifying: (i) von Willebrand factor VIII antigen (vW)-immunopositive
endothelial cells; (ii) Ki67-positive proliferating cells; and (iii)
bromodeoxyuridine-positive proliferating cells. Marmoset corpora lutea were
examined throughout the cycle, and natural regression was compared with induced
luteolysis after administration of a prostaglandin F(2alpha) analogue or
gonadotrophin-releasing hormone (GnRH) antagonist. Steroidogenic and endothelial
cells were positive for proliferation markers. Endothelial cell proliferation was
highest during luteal formation, then decreased and remained low during the
luteal phase and functional regression, however endothelial cell proliferation
increased during structural regression. Endothelial cell proliferation was
unchanged by induced regression. The area of vW immunostaining was highest during
luteal formation, decreased thereafter and remained constant during the luteal
phase and regression. Distribution of immunostaining indicated the presence of an
extensive capillary network, but during structural regression the numbers of
capillaries decreased and numbers of microvessels increased. These results
suggest that vascular changes are concurrent with changes in the functional
status of the marmoset corpus luteum.
PMID- 10686197
TI - Rescue of oocytes from antral follicles of cryopreserved mouse ovaries:
competence to undergo maturation, embryogenesis, and development to term.
AB - Only primordial and primary follicles of frozen-thawed mouse ovaries survive
after grafting to the ovarian bursa; large secondary follicles and antral
follicles together with the oocytes contained in them degenerate. This study was
undertaken to determine whether fully grown oocytes isolated from the antral
follicles of frozen-thawed mouse ovaries are viable and can be rescued to undergo
maturation, fertilization, and embryo development in vitro. Ovaries were
cryopreserved after removal from 22-day-old (C57BL/6J x SJL/J)F(1) mice, with or
without prior priming with equine chorionic gonadotrophin, and fresh non-frozen
ovaries were used as controls. Only cumulus cell-denuded oocytes were recovered
from frozen unprimed ovaries while both cumulus cell-enclosed and denuded oocytes
were retrieved from frozen primed ovaries. Oocytes from both groups of frozen
thawed ovaries were able to undergo maturation, fertilization, and development to
the blastocyst stage in vitro, though at lower percentages than oocytes from
control unfrozen ovaries. Moreover, 19% of 2-cell stage embryos derived from
frozen-thawed primed ovaries, compared with 42% of embryos derived from control
primed ovaries, developed to term after transfer to pseudopregnant foster mothers
(not significantly different). Therefore, fully grown oocytes in antral follicles
survive the cryopreservation protocol, as demonstrated by maturation,
fertilization and embryo development in vitro, and development to term after
embryo transfer.
PMID- 10686198
TI - Transplantation of cultured explants of human endometrium into nude mice.
AB - The objective of this study was to analyse the histological and
immunohistochemical characteristics of cultured explants of human endometrium
transplanted into nude mice. Biopsies of eutopic endometrium were taken from six
patients during laparoscopic surgery and classified according to the phase of the
cycle. All the explants were cultured with oestrogen and progesterone for 24 h
before transplantation into 15 mice. Four mice were grafted with explants of
menstrual endometrium, four with explants of late proliferative endometrium, and
seven with explants of late secretory-premenstrual endometrium. Typical
endometrial glands and stroma were observed in 87% of cases 3 weeks after the
transplantation. All the grafts revealed histological characteristics of the
proliferative phase, even when the endometrial biopsy was taken during the late
secretory phase. Immunohistochemical studies revealed that the proliferation
index was high, whatever the menstrual phase of the endometrial biopsy. An
extensive vascular network developed at the interface between the graft and the
surrounding tissue. Vascular endothelial growth factor (VEGF) positive stained
cells were observed in all grafts, the VEGF score being significantly higher in
epithelial cells than in stromal cells. In conclusion, human endometrial
explants, cultured for 24 h, could be successfully transplanted into nude mice.
Immunohistochemical studies proved that human cultured endometrial tissue could
not only survive in nude mice but could also become very active and develop
characteristics different from the tissue of origin. An active vascular network
is a necessary condition for the survival of the graft and may be explained by
the high VEGF content.
PMID- 10686199
TI - Production of inhibin forms by the fetal membranes, decidua, placenta and fetus
at parturition.
AB - Inhibins are regulators of paracrine and endocrine function during pregnancy, but
their intrauterine sites of secretion are not well established. In amniotic
fluid, inhibin A-, inhibin B- and inhibin pro-alphaC-containing isoforms were
present in high concentrations, whereas in maternal serum, inhibin A and pro
alphaC forms were present in high amounts, with low concentrations of inhibin B.
In fetal cord serum, inhibin pro-alphaC was present in all samples, inhibin B was
detectable in male but not female fetuses, with no detectable inhibin A in either
sex. From cultured explants, both inhibin A and B were secreted by chorion laeve,
whereas only inhibin A was secreted by placenta, with both tissues secreting
inhibin pro-alphaC. Only low concentrations of both dimeric inhibins and pro
alphaC forms were secreted by decidua parietalis and amnion. The dual perfused
placental cotyledon secreted both inhibin A and pro-alphaC into maternal
perfusate, but only inhibin pro-alphaC into the fetal circulation and less than
to the maternal side. We conclude that trophoblast is the predominant source of
dimeric inhibins, but with markedly different secretion depending on its
intrauterine location. There was a significant decrease in inhibin A and pro
alphaC in amniotic fluid collected at term active labour compared to elective
Caesarean section (P < 0.001). This may reflect a local change in inhibin/activin
processing at labour, likely in chorion laeve trophoblast cells, which may be
important in the paracrine control of the feto-maternal communication required to
maintain pregnancy and initiate labour.
PMID- 10686200
TI - Fluorescence diagnosis of endometriosis on the chorioallantoic membrane using 5
aminolaevulinic acid.
AB - The chorioallantoic membrane (CAM) is a useful model for the fluorescence
diagnosis of experimentally induced endometriosis. In our experimental setup
75.7% of the histologically examined tissue preparations were viable and only
24.3% showed signs of necrosis on the CAM after various periods of incubation.
Best results were obtained when grafting to the CAM was performed between days 7
and 9 and when implants were left on the CAM for 3-5 days (P < 0.05). We were
able to demonstrate that 5-aminolaevulinic acid (ALA) is stored selectively in
ectopic endometrium. The subsequent fluorescence of the endometrium shows a rapid
increase that reaches a peak after 10-14 h which can be clearly differentiated
from the weaker fluorescence of grafted normal peritoneum and fimbriae (P <
0.01).
PMID- 10686201
TI - Reproductive features in women developing ovarian granulosa cell tumour at a
fertile age.
AB - Ovarian granulosa cell tumour (GCT) is a rare malignancy, which has been linked
to both infertility and infertility treatment with ovulation inducers. The
reproductive features were analysed of 146 women with GCT diagnosed between 1956
and 1996. During the study period no changes were found in the mean age (53
years), menopausal status (59% postmenopausal), parity (32% nulliparous) or
tumour size or stage at diagnosis. The clinical features in women with GCT at
fertile age were compared with GCT diagnosed later in life and to population
based data. Nulliparity (50%) and history of infertility (22%) were more frequent
if the tumour occurred at fertile age (n = 50). Of the 12 infertile cases, seven
had anovulatory infertility (58%); 11 occurred during the era of ovulation
inducers, but only five had used these drugs (clomiphene citrate in five
patients, gonadotrophins in two, and tamoxifen in one patient) and no patient had
undergone in-vitro fertilization. Endometrial hyperplasia was associated with GCT
at all ages, while endometrial cancer was found solely after the age of 45 years.
In conclusion, GCT at fertile age is associated with nulliparity and with a
clinical presentation of anovulatory infertility, while GCT later in life is
associated with a more normal average fertility pattern and with occurrence of
endometrial cancer.
PMID- 10686202
TI - Repetitive complete hydatidiform mole can be biparental in origin and either male
or female.
AB - Complete hydatidiform mole (CHM) is an abnormality in pregnancy due to a diploid
conception which is generally androgenetic in origin, i. e. all 46 chromosomes
are paternally derived. We have examined the genetic origin of repetitive
hydatidiform moles in a patient having three CHM by two different partners, and
no normal pregnancies. Using fluorescent microsatellite genotyping, we have shown
all three CHM to be biparental, rather than androgenetic, in origin. Examination
of informative markers for each homologous pair of chromosomes, in two of the
CHM, failed to reveal any evidence of unipaternal disomy, suggesting that the
molar phenotype might result from disruption of normal imprinting patterns due to
a defect in the maternal genome. It has been suggested that intracytoplasmic
sperm injection (ICSI), followed by selection of male embryos, can prevent
repetitive CHM; but examination of sex chromosome-specific sequences in the three
CHM described here, showed that, while two were female, the first CHM was male.
Selection of male embryos is therefore unlikely to prevent repetitive CHM in this
patient. Our results suggest that the genetic origin of repetitive CHM should be
determined prior to in-vitro fertilization (IVF) and that current strategies for
the prevention of repetitive CHM may not be appropriate where the CHM are of
biparental origin.
PMID- 10686203
TI - Menopause and risk of non-fatal acute myocardial infarction: an Italian case
control study and a review of the literature.
AB - The relationship between menopause and non-fatal acute myocardial infarction
(AMI) was considered by analysing data from a case-control study conducted in
Italy between 1983 and 1992. Cases were 429 women, below age 75 years, with a
first episode of non-fatal AMI, admitted to 30 coronary care units; controls were
863 women admitted to the same network of hospitals for acute diseases other than
cardiovascular, neoplastic, or hormone-related. Postmenopausal women were not at
higher risk of AMI than pre/perimenopausal women, after adjustment for age and
other selected covariates [multivariate odds ratio (OR) 0.99]. With reference to
age at menopause, compared with women reporting menopause when <45 years, the
multivariate OR were 1.54 for those aged 45-49 at menopause, 1.36 for those aged
50-52 years, and 0.97 for those aged >/=53, in the absence of any trend in risk.
No meaningful relationship emerged with time since menopause (OR 0.85 for <10
years since menopause). The results were similar in women aged <60 and >/=60
years at AMI. Although the present study does not support a substantial
relationship between menopause and non-fatal AMI, the overall epidemiological
evidence is compatible with a moderate association.
PMID- 10686204
TI - Incidence of cancer in children born after in-vitro fertilization.
AB - Evaluation of the long-term health of children born using in-vitro fertilization
(IVF) provides important information to clinicians and consumers. Until very
recently, there have been no published data on the incidence of cancer in
children conceived as a result of IVF, despite a number of case reports of
neuroblastoma in children conceived using fertility drugs. This study used a
record-linkage cohort design to investigate the incidence of cancer in children
born after IVF. The study included all conceptions using assisted reproductive
technologies between 1979 and 1995 at two clinics in Victoria, Australia that
resulted in a live birth. Data on births were linked with a population-based
cancer registry to determine the number of cases of cancer that occurred. The
standardized incidence ratio (SIR) was calculated by comparing the observed
number of cases to the expected number of cases. The final cohort included 5249
births. The median length of follow-up was 3 years, 9 months (range 0-15 years).
In all, 4.33 cases of cancer were expected and six were observed, giving a SIR of
1.39 (95% CI 0.62-3.09). This study found that children conceived using IVF and
related procedures did not have a significantly increased incidence of cancer in
comparison to the general population.
PMID- 10686205
TI - Hydatidiform mole coexistent with a twin live fetus: a national collaborative
study in Japan.
AB - A national collaborative study was conducted in Japan to evaluate the clinical
course and the sequelae of patients with hydatidiform mole coexistent with twin
live fetus (HMTF). Seventy-two cases of HMTF were diagnosed based on gross
appearance and histopathological criteria. In 18 cases, the molar parts were
cytogenetically confirmed to be of androgenetic origin (complete mole). The
overall incidence of persistent trophoblastic tumour (PTT) in patients with HMTF
was 30.6%, and it increased to 50.0% in the 18 patients with proven androgenetic
complete mole coexistent with twin live fetus (CHMTF). Among these patients, the
mean gestational age at termination of pregnancy or delivery in those who
developed PTT (n = 9) and those who did not (n = 9) were 20.6 and 19.4 weeks
respectively. The incidence of severe maternal complications was significantly
higher in patients who subsequently developed PTT (P < 0.05). The rate of
subsequent development of PTT in patients with CHMTF was found to be considerably
higher than in a previous study of patients with single complete mole (50 and
12.5% respectively). However, since the risk of malignancy is unchanged with
advancement of gestational age, continued pregnancy may be allowed in patients
with HMTF provided that severe maternal complications are controlled and fetal
karyotype and development are normal.
PMID- 10686206
TI - Polycystic ovaries and recurrent miscarriage--a reappraisal.
AB - The prevalence of polycystic ovaries (PCO) was established amongst 2199
consecutive women (median age 33 years; range 19-46) with a history of recurrent
miscarriage (median 3; 3-14). A diagnosis of PCO was made if the ovarian volume
was enlarged (>9 ml), there were >/=10 cysts of 2-8 mm in diameter in one plane
and there was increased density of the stroma. In a cohort study, the prospective
pregnancy outcome of 486 of the women scanned who were antiphospholipid antibody
negative and who received no pharmacological treatment during their next
pregnancy was studied. The prevalence of PCO was 40.7% (895/2199). The livebirth
rate was similar amongst women with PCO (60.9%; 142/233) compared to that amongst
women with normal ovarian morphology (58.5%; 148/253; not significant). Neither
an elevated serum luteinizing hormone concentration (>10 IU/l) nor an elevated
serum testosterone concentration (>3 nmol/l) was associated with an increased
miscarriage rate. Polycystic ovarian morphology is not predictive of pregnancy
loss amongst ovulatory women with recurrent miscarriage conceiving spontaneously.
The search for a specific endocrine abnormality that can divide women with PCO
into those with a good and those with a poorer prognosis for a future successful
pregnancy continues.
PMID- 10686207
TI - Embryo transfer under ultrasound guidance improves pregnancy rates after in-vitro
fertilization.
AB - Between October 1998 and January 1999, we examined the influence of ultrasound
guidance in embryo transfer on pregnancy rate in 362 patients from our in-vitro
fertilization (IVF)-embryo transfer programme. These patients were prospectively
randomized into two groups: 182 had ultrasound-guided embryo replacement, and 180
had clinical touch embryo transfer. There were no statistically significant
differences between the two groups with respect to age, cause of infertility and
in the characteristics of the IVF cycle. The pregnancy rate was significantly
higher among the ultrasound-guided embryo transfer group (50%) compared with the
clinical touch group (33.7%) (P < 0.002). Furthermore, there was also a
significant increase in the implantation rate: 25.3% in the ultrasound group
compared with 18.1% in the clinical touch group (P < 0.05). In conclusion,
ultrasound assistance in embryo transfer significantly improved pregnancy and
implantation rates in IVF.
PMID- 10686208
TI - Intrauterine donor insemination in single women and lesbian couples: a
comparative study of pregnancy rates.
AB - The outcome of intrauterine donor insemination (IUI-DI) with frozen spermatozoa
was analysed retrospectively in 675 cycles in single women (n = 122; 536 cycles)
and lesbian (n = 35; 139 cycles) couples. The lesbian patients were younger at
the initiation of treatment (mean 34.5 years; range 26-44) than the single women
(mean 38.5; range 29-47) (P = 0.005). Clinical pregnancy rate was 36% in single
women and 57% in lesbians (P < 0.05), the cumulative pregnancy rate after six
cycles being 47% and 70% respectively, although the outcome was similar when
related to age. The miscarriage rate was higher (35%) in single women than in
lesbians (15%; P < 0.05), the rate being independent of maternal age. There were
no apparent differences seen between the two groups with respect to the possible
effect of parity, duration of infertility, causes of infertility and type of
treatment at initiation of treatment; the sole exception was that the age of
lesbian women was statistically significantly younger than that of single women
(P < 0.005). When corrected for age, the pregnancy rates and complications were
lower and higher respectively in single women but these differences did not reach
statistical significance. However, the disparity between the treatment outcomes
of single women and lesbian patients of similar ages may also reflect the fact
that single women are likely to have failed to conceive for a period of time
prior to referral to a specialist centre for treatment.
PMID- 10686209
TI - Successful twin pregnancy in a dual-transplant couple resulting from in-vitro
fertilization and intracytoplasmic sperm injection: case report.
AB - There are numerous reports of successful pregnancy following liver
transplantation. Little information is available regarding the incidence and
management of infertility in transplant recipients, particularly the use of
artificial reproductive technologies. We present a case of a successful twin
pregnancy resulting from in-vitro fertilization with intracytoplasmic sperm
injection (IVF/ICSI) in a liver transplant recipient, whose partner was a renal
transplant recipient with severe oligozoospermia. With careful evaluation and
monitoring, and the involvement of appropriate consultants, artificial
reproductive technologies can be safely used in transplant recipient couples
experiencing infertility.
PMID- 10686210
TI - Single monthly administration of the anti-progestagen Org 31710 in users of the
75 microg desogestrel progestagen-only pill: effects on pituitary-ovarian
activity.
AB - Endocrine and ultrasound effects were studied of an intermittent (every 28 days)
oral administration of 150 mg of the anti-progestagen Org 31710 during the
continued daily use of 75 microg desogestrel (DSG) for progestagen-only
contraception. A randomized, double-blind, placebo-controlled two-centre study
was conducted in 50 healthy volunteers. Serum luteinizing hormone (LH), follicle
stimulating hormone (FSH), oestradiol and progesterone concentrations, and
follicle number and size were studied, as well as endometrial thickness, which
was assessed by transvaginal sonography at least twice weekly during a single
medication cycle (cycle 3-5). Forty-eight women were evaluated (Org 31710, n =
25; placebo, n = 23). Seven ovulations were observed in the treated group versus
none in the placebo group. LH concentrations were higher on days 9 and 11 and
oestradiol concentrations lower on day 3 in the treated group, irrespective of
whether ovulation occurred. No parameter could predict ovulation. Endometrial
thickness was greater on cycle days 7-13 and 19 in the treated group. However,
within the Org 31710 group, no significant differences were found in volunteers
who did or did not ovulate. Observed differences may be attributed to a
competitive effect of Org 31710 with progestagen-induced suppression of the
pituitary-ovarian axis, altered oestradiol feedback mechanisms, and/or altered
receptor availability.
PMID- 10686211
TI - Potential impact of hormonal male contraception: cross-cultural implications for
development of novel preparations.
AB - The prospect of a hormonal male contraceptive is no longer distant. Data on the
potential impact of this improvement in contraceptive provision, however, is
limited, particularly between different cultures. We have therefore carried out a
multi-centre study to assess men's attitudes to proposed novel hormonal methods.
Questionnaire-based structured interviews were administered to men in Edinburgh,
Cape Town, Shanghai and Hong Kong. Approximately 450 men were interviewed in
Edinburgh, Shanghai and Hong Kong, and a slightly larger group (n = 493) in Cape
Town to give samples (n > 150) of black, coloured and white men. Knowledge of
existing male and female methods of contraception was high in all centres and
groups. The majority of men welcomed a new hormonal method of contraception, 44
83% stating that they would use a male contraceptive pill. Overall, a pill was
more acceptable than an injectable form (most popularly given at 3-6 month
intervals); long-acting implants were least so except in Shanghai. Familiarity
with comparable female methods appeared to influence acceptability, for both oral
and injectable methods. Hong Kong was the only centre where a male method
(condom) was currently the most commonly used; men there appeared to rate the
convenience of condoms highly while being least likely to think that they
provided effective protection against pregnancy compared to other centres, and
were least enthusiastic about novel male methods. The acceptability of potential
male hormonal methods of contraception was high in some groups but showed wide
variability, determining factors including cultural background and current
contraceptive usage. These results suggest that the emerging emphasis that men
should have greater involvement in family planning will be substantiated when
appropriate contraceptive methods become available.
PMID- 10686212
TI - Would women trust their partners to use a male pill?
AB - Despite a renewed interest in the development of hormonal contraceptives for men,
many discussions about the potential acceptability of a 'male pill' end by
speculating whether women would trust their partners to use the method reliably.
To determine the views of women, we undertook a survey of 1894 women attending
family planning clinics in Scotland (450), China (900) and South Africa (544). In
all centres over 65% of women thought that the responsibility for contraception
falls too much on women. More than 90% in South Africa and Scotland thought that
a 'male pill' was a good idea, with Chinese women (71% in Hong Kong and 87% in
Shanghai) only slightly less positive. Only 13% of the total sample did not think
that hormonal male contraception was a good idea and only 36 women (2% of the
total) said that they would not trust their partner to use it. 78% of Scottish
women, 71% of Shanghai women, and 78% of white women and 40% of black and
coloured women in Cape Town thought that they would use the method. This survey
should dispel the myth that women would not trust their partners to use a 'male
pill' reliably and illustrates the potential market for the method.
PMID- 10686213
TI - Intrauterine polyps--a cause of unscheduled bleeding in women using the
levonorgestrel intrauterine system: case report.
AB - The levonorgestrel intrauterine releasing system is a contraceptive that has been
shown to reduce menstrual blood loss dramatically. Breakthrough bleeding,
however, is a relatively common occurrence as with all methods of progestogen
only contraception and this limits its acceptability for women. Amenorrhoea can
be achieved in the majority of women within 12 months of insertion. Any new
pattern of bleeding after amenorrhoea or a persistence of heavy bleeding may be
due to co-existing intrauterine pathology such as endometrial polyps. The use of
out-patient techniques such as hysteroscopy and saline infusion sonography are
indicated in these instances to exclude other intrauterine pathology.
PMID- 10686214
TI - Prospective comparative study between microsurgical and conventional testicular
sperm extraction in non-obstructive azoospermia: follow-up by serial ultrasound
examinations.
AB - The value of testicular sperm extraction (TESE) by microdissection was evaluated
according to its physiological consequences compared with open, classic surgical
biopsy in the same patient. A total of 100 patients with non-obstructive
azoospermia and bilateral identical testicular histology underwent bilateral
diagnostic TESE via the conventional method on one side and the microsurgical
method on the other side. The spermatozoa recovery rate by microdissection TESE
was significantly higher than by conventional TESE (47 and 30% respectively; P <
0.05). In order to assess the safety of this new procedure, 60 patients were
followed-up ultrasonographically for 1, 3 and 6 months. Acute and chronic
complications were significantly lower in the microsurgical side compared with
the conventional side (15 and 58.3% respectively and 3 and 30% respectively; P <
0.05). Segmental devascularization was detected in seven testes operated on
conventionally, and in two testes operated on microsurgically. However, permanent
devascularization could not be detected in any patient after 6 months. These
findings suggest that microdissection TESE is not devoid of complications, but
that it is relatively safer than the conventional technique and improves sperm
yield significantly in patients with non-obstructive azoospermia.
PMID- 10686215
TI - Sperm chromatin packaging as an indicator of in-vitro fertilization rates.
AB - The development of a sequential diagnostic schedule for patients consulting for
infertility disturbances would be an ideal method of approach for clinicians in
the absence of an aetiological or pathophysiological diagnosis. Since sperm
morphology recorded by strict criteria has often been correlated with
fertilization failure, the present study aimed to evaluate the relationship
between normal morphology as well as in-vitro fertilization (IVF) rates, with
chromatin staining among fertile and subfertile men. Two semen smears were
prepared from each specimen obtained from 72 men to record normal morphology and
chromatin packaging as recorded by chromomycin A(3) (CMA(3)) staining. Following
the semen analyses, the 72 men were divided into the two morphological groups,
namely <4% and >4% normal forms. Significantly different percentages of CMA(3)
staining (mean +/- SE) were recorded between the two morphological groups, namely
65.9% +/- 3.5 and 44.5% +/- 1.7 (P +/- 0.001). A highly negative significant
correlation existed between percentage of normal morphology as recorded by strict
criteria and CMA(3) staining. A highly significant and positive correlation was
recorded for normal morphology and IVF rates (r +/- 0.45, P +/- 0.0001). A
significant negative correlation (r +/- -0.51, P +/- 0.0001) existed between
CMA(3) values and IVF rates. The discriminating power of nuclear maturity, as
recorded by CMA(3) staining, to identify abnormal morphology values and poor IVF
rates was calculated with receiver operator characteristic (ROC) analyses. The
areas under the ROC curves were 0.86 for sperm morphology and 0. 74 for IVF
rates. The calculated threshold values for CMA(3) staining to distinguish between
morphology groups were 48 and 50% for IVF. Chromatin packaging assessment is a
valuable addition to the sequential diagnostic programme in an assisted
reproductive arena.
PMID- 10686216
TI - Bacterial contamination and sperm recovery after semen preparation by density
gradient centrifugation using silane-coated silica particles at different g
forces.
AB - The effects of density gradient centrifugation through silane-coated silica
particles (PureSperm) using 100, 200, 300 and 500 g on bacterial contamination of
sperm samples and recovery of motile spermatozoa from sperm samples were
investigated with conventional culturing techniques and microscopic visual
assessment. The recovery of motile spermatozoa was variable and was not improved
using 500 g compared to the recommended 300 g. The bacterial contamination was
highly decreased by gradient centrifugation through PureSperm and was almost
abolished when strict aseptic techniques were used, with changes to sterile
Pasteur pipettes and tubes prior to washing procedures.
PMID- 10686217
TI - The development of a continuous quality control programme for strict sperm
morphology among sub-Saharan African laboratories.
AB - Inter-technician and between-laboratory differences, especially during the
evaluation of sperm morphology, have been a major cause of concern. The study
aimed to develop an intensive training programme with intervals of continuous
quality control assessments for sperm morphology. Twenty andrology laboratories
from sub-Saharan Africa were invited to participate in a World Health
Organization Special Programme of Research, Development and Research Training in
Human Reproduction semenology workshop. Following intensive training in strict
sperm morphololgy evaluation, a continuous quality control programme was
introduced on a quarterly basis. At baseline, the mean (+/- SD) percentage
difference reported between the participants and the reference laboratory reading
was 33.50 +/- 11%. After training, the mean percentage difference had decreased
to 14.32 +/- 5% at 3 months and to 5.00 +/- 5% at 6 months. Pairwise comparison
of the differences at each evaluation time revealed the following: Baseline
differences (pre-training) differed significantly from the differences at 3
months (P = 0.0002) as well as at 6 months after training (P = 0.007). The
differences at 6 months did not differ significantly from those at 3 months (P =
0.27). Training of andrology technicians as well as continuous proficiency
testing can be conducted on a national and international level with the support
of a referring laboratory. Global quality control measurements in andrology
laboratories should become mandatory, since these results indicate that
continuous quality control for laboratory technicians can be highly successful.
PMID- 10686218
TI - Oestradiol enhances testosterone-induced suppression of human spermatogenesis.
AB - The aim of this study was to determine for the first time in humans, the efficacy
of adding a low dose oestradiol to a suboptimally suppressive testosterone dose
in a depot hormonal regimen to suppress spermatogenesis in healthy eugonadal men.
Twenty-six healthy men were randomized into groups that were treated by a single
subdermal implantation of either 600 mg testosterone alone (T; n = 11) or
together with 10 mg (TE10, n = 7) or 20 mg (TE20, n = 8) oestradiol.
Administration of oestradiol produced a dose-dependent increase in peak plasma
oestradiol at 1 month and prolonged suppression of plasma LH and FSH leading to
significantly enhanced suppression of sperm output. Despite the augmented
spermatogenic suppression, there was no significant difference in the proportions
achieving azoospermia (6/26, 23%) or severe oligozoospermia (<1 or <3 x 10(6)
spermatozoa per ml, 7/26, 27%) and overall these proportions were inadequate to
provide reliable contraception according to the standards identified in World
Health Organization male contraceptive efficacy studies. Total and free
testosterone remained within the eugonadal reference range for young men
throughout the study. While the lower oestradiol dosage had minimal spermatogenic
suppression effects, the higher dose produced dose-limiting adverse effects of
androgen deficiency and/or oestrogen excess between the fourth and sixth month of
the study. This appeared to be due to the unexpectedly prolonged, low
concentration of oestradiol release from the oestradiol implants. There were no
significant treatment-related changes in body composition, lipids, prostate
specific antigen, haematological or biochemical variables. Thus oestradiol has a
low therapeutic window and dose-limiting side-effects at dosages that fail to
achieve the uniform azoospermia required of an effective male hormonal
contraceptive regimen.
PMID- 10686219
TI - Results of the American Association of Bioanalysts national proficiency testing
programme in andrology.
AB - Proficiency testing samples for antisperm antibodies (ASAB), sperm count,
morphology and vitality were mailed to participating laboratories. The majority
participating utilized Immunobead ASAB procedures (81 versus 14% mixed
antiglobulin reaction and 5% 'other'), and there was 95.6 +/- 1.2% agreement on
the presence or absence of ASAB. The majority of laboratories utilized manual
(79%) versus computer assisted semen analysis (CASA; 15%) methods. Approximately
64% used the haemocytometer and 26% used the Makler counting chambers for manual
counts. Coefficients of variation (CV) in sperm counts ranged from 24 to 138%,
with CASA displaying lower overall CV (53 +/- 8%) than manual methods (80 +/-
9%). A wide variation in the reports of percent normal morphology was noted (CVs
calculated from arc sin transformed means ranged from 15 to 93%). Participants
using American Society of Clinical Pathologists (ASCP) criteria reported sperm
morphology values that were clustered in the 'normal' range (11 out of 12
samples), while those using strict criteria were clustered in the 'abnormal'
range (10 out of 12 samples). Good agreement was observed in sperm vitality
(overall mean CV = 18%). These data highlight the urgent need for improvement in
overall quality of andrology testing and indicate that practical proficiency
testing programmes can be made available on a large scale.
PMID- 10686220
TI - Adhesion formation in intubated rabbits increases with high insufflation pressure
during endoscopic surgery.
AB - The aim of the study was to test the hypothesis that the increase in adhesion
formation by CO(2) pneumoperitoneum is caused by mesothelial hypoxaemia.
Therefore the effect of the intra-abdominal pressure together with the flow rate
upon adhesion formation was evaluated in rabbits following laser and bipolar
lesions during endoscopic surgery using humidified CO(2) at 35 +/- 1 degrees C.
The intra-abdominal pressure and flow rate were 5 mmHg and 1 l/min in group 1 (n
= 5), 5 mmHg and 10 l/min in group 2 (n = 4), 20 mmHg and 1 l/min in group 3 (n =
5) and 20 mmHg and 10 l/min in group 4 (n = 4) respectively. A rapid and reliable
intubation method for rabbits was developed to permit high insufflation pressure.
By two-way analysis of variance, total adhesion scores following a laser lesion
increased with flow rate (P = 0.0003) and insufflation pressure (P = 0.002).
Total adhesion scores of bipolar lesions increased with pressure (P = 0.02) but
not with flow rate (P = 0.1). The total adhesion scores of laser and bipolar
lesions together increased with flow rate (P = 0.005) and with insufflation
pressure (P = 0.004). There was no statistical interaction between flow rate and
insufflation pressure. In conclusion, the insufflation pressure in endoscopic
surgery with CO(2) pneumoperitoneum is a co-factor in adhesion formation,
together with desiccation.
PMID- 10686221
TI - Laparoscopic creation of a neovagina in a woman with a kidney transplant: case
report.
AB - The successful use of Vecchietti's technique for creating a neovagina in a case
of Rokitansky syndrome with an associated transplanted kidney is reported. The
technique is performed by means of a laparoscopic approach, adapted to the
special anatomical situation, in order to avoid renal injuries. The
accomplishment of a normally functioning neovagina, with no intra-operative or
post-operative complications, proves that this technique can also be applied
satisfactorily to this type of patient.
PMID- 10686222
TI - Flow of cells from polar to mural trophectoderm is polarized in the mouse
blastocyst.
AB - During growth of the blastocyst there is a net flow of cells from the polar to
the mural trophectoderm which is presumed to be radially symmetrical. However,
such a pattern of cell movement is inconsistent with findings from a recent
clonal analysis. To visualize the overall flow of cells directly, the polar
trophectoderm of expanding blastocysts was labelled globally with fluorescent
microspheres. Following further growth, the great majority of blastocysts that
remained labelled throughout the polar trophectoderm exhibited a polarized rather
than radial spread of label into the mural region. This was the case regardless
of the labelling technique, whether the blastocysts were grown in utero or in
vitro, or had the zona pellucida removed or left on. Intriguingly, where there
were two foci of spread of label into the mural trophectoderm rather than one,
these were diametrically opposite each other. In further experiments, fluorescent
lineage labels were used to distinguish junctional trophectoderm cells with and
without an extension onto the blastocoelic surface of the inner cell mass. The
location of clones formed following further blastocyst growth provided no
evidence that egress of cells from the polar trophectoderm is restricted
circumferentially by the presence of junctional cells having an extension.
PMID- 10686223
TI - Defective sperm-zona pellucida interaction: a major cause of failure of
fertilization in clinical in-vitro fertilization.
AB - Sperm-zona pellucida binding and penetration were assessed on the oocytes that
failed to fertilize from couples with >/=3 oocytes treated by standard in-vitro
fertilization (IVF). There were four groups: fertilization rate 0% (n = 369), 1
25% (n = 194), 26-50% (n = 81) and 51-95% (n = 100). Of the couples with zero
fertilization rate 70% had =5 spermatozoa bound per zona pellucida and 42% had
no spermatozoa penetrating the zona pellucida of any oocyte. In contrast, in the
51-95% fertilization rate group, only 17% had = 5 spermatozoa bound per zona
pellucida and 6% had no spermatozoa penetrating the zona pellucida. There was a
significantly higher frequency of poor sperm morphology (= 5% normal) in
couples with zero fertilization rate (36%) than in the fertilization rate group
51-95% (7%). Incubation of oocytes from 68 couples with zero fertilization rate
and low sperm-zonae pellucidae binding with fertile donor spermatozoa resulted in
normal sperm-zona pellucida binding and most zonae pellucidae being penetrated.
In conclusion, defective sperm-zona pellucida interaction was the major cause for
low fertilization rates in standard IVF. This was usually because of defects of
the spermatozoa rather than defects of the oocytes. Sperm defects likely to cause
failure of fertilization should be diagnosed before commencing IVF and the
patients directed to intracytoplasmic sperm injection.
PMID- 10686224
TI - A comparison of two regimens of intravaginal misoprostol for termination of
second trimester pregnancy: a randomized comparative trial.
AB - A prospective randomized trial was conducted in 148 women to compare the efficacy
of two regimens of vaginal misoprostol for termination of second trimester
pregnancy. Women aged 16-40 years requesting termination of second trimester
pregnancy were randomized into two groups. Women in group 1 were given vaginal
misoprostol 400 microg every 3 h for a maximum of five doses in 24 h. Women in
group 2 were given vaginal misoprostol 400 microg every 6 h for a maximum of
three doses in 24 h. If women did not abort in 24 h, the same regimen was
repeated. The median induction-abortion interval in group 1 (15.2 h) was
significantly shorter (P < 0.01) than that in the group 2 (19.0 h). The
percentage of women who achieved successful abortion within 48 h in group 1
(90.5%) was also significantly higher (P < 0.02) than that in group 2 (75.7%).
The incidence of fever was more common in group 1 (P = 0.01). It is concluded
that the regimen of vaginal misoprostol 400 microg every 3 h with maximum of five
doses in 24 h was more effective than the regimen of misoprostol every 6 h in
termination of second trimester pregnancy.
PMID- 10686225
TI - Cytokine production by maternal lymphocytes during normal human pregnancy and in
unexplained recurrent spontaneous abortion.
AB - It has been proposed that successful pregnancy is a T helper 2-type phenomenon,
and that T helper (Th)1-type reactivity is deleterious to pregnancy. The
objective of this study was to compare the concentrations of Th1 and Th2
cytokines produced by peripheral blood mononuclear cells from women undergoing
unexplained recurrent spontaneous abortion (RSA) with those produced during
normal pregnancy at a similar gestational stage. The control group consisted of
24 women with a history of successful pregnancies and the abortion group
comprised of 23 women with a history of unexplained RSA. Blood from the control
group was obtained at the end of the first trimester as gestational age controls
for the abortion group from whom blood was collected at the time of abortion.
Phytohaemagglutinin-stimulated peripheral blood cell culture supernatants were
analysed for concentrations of cytokines. Significantly higher concentrations of
Th2 cytokines were produced by the first trimester normal group than by the RSA
group, while significantly higher concentrations of Th1 cytokines were produced
by the abortion group as compared to first trimester normal pregnancy, indicating
a distinct Th2-bias in normal pregnancy and a Th1-bias in unexplained RSA.
PMID- 10686226
TI - Termination of pregnancy after conception with donor oocytes and donor
spermatozoa: case report.
AB - Two couples, each suffering from longstanding primary subfertility due to severe
oligoasthenoteratozoospermia in the male partner and perimenopause in the female,
were referred to Bourn Hall Clinic for assisted conception treatment. Both
couples received independent counselling prior to being accepted onto our
programme. Both women conceived following embryo transfer. The embryos were
created from (separate) donor oocytes and donor spermatozoa, and three and two
embryos were transferred respectively. The first recipient conceived a triplet
pregnancy, while the second conceived a twin pregnancy. Both felt unable to cope
with their multiple pregnancies and declined further counselling. Both were
offered elective fetal reduction; however, both declined and both decided to
terminate their pregnancies. Both patients underwent termination of pregnancy,
despite being advised against it. The reasons couples may opt for termination of
their much-wanted pregnancies, after a protracted period of infertility,
intensive and expensive infertility treatment and despite the counselling they
receive before, during and after their treatment, are discussed.
PMID- 10686227
TI - Optimal use of infertility diagnostic tests and treatments. The ESHRE Capri
Workshop Group.
AB - The general definition of infertility is a lesser capacity to conceive than the
mean capacity of the general population and infertile couples can be
characterized in two groups: those unable to conceive without therapy and those
who are hypofertile, but conceive without therapy. The initial diagnostic tests
for infertility should include a midluteal phase progesterone assay, a semen
analysis and a test for tubal patency such as a hysterosalpingogram. Measuring
progesterone is the best test for confirming ovulation. To predict ovulation,
evaluating the luteinizing hormone (LH) surge is the best single assay while
measurement of LH plus preovulatory oestrogen is the best prediction. Today
primary investigation of the morphology of the uterus and tubes should be by
hysterosalpingography. However, ultrasound, particularly with simple contrast
media, is likely to gain in importance. Laparoscopy should be reserved as a
further diagnostic procedure or in combination with endoscopic surgery. There are
situations in which semen analysis is of utmost importance and of absolute
predictive value, namely, in cases of azoospermia. In general semen analysis
remains a substantial part of the fertility workup, but any consideration of its
predictive value has to be cautious. Performing genetic tests before, during and
after assisted reproductive techniques (ART) is an intrinsic part of good
clinical practice. These tests allow one to reach a correct diagnosis, to give
adequate genetic counselling to the couple and their families in cases such as
(i) women with Turner syndrome; (ii) men with 47, XXY; (iii) men or women with
structural chromosomal aberration; (iv) men with Yq11 deletion or (v) men with
congenital bilateral absence of vas deferens. Patients should, of course, be made
aware of the occurrence of de-novo mutations taking place in the testis and in
the embryo. Treatment of some causes of infertility are of proven value. For
example induction of ovulation. Others are more controversial. Among the many
empirical treatments suggested for the treatment of the various form of
subfertility, surgical treatment of varicocele in the male, treatment of pelvic
endometriosis in the female and the efficacy of the ART strategies offered to the
subfertile couple are considered. Many varicocele studies are of poor quality. A
few are good, but small in size. They do not show an improvement in pregnancy
rates. Therefore, at the moment, there is insufficient scientific evidence for
recommending routinely surgical treatment in subfertile and/or oligozoospermic
men with a varicocele. Randomized, double-blind controlled trials demonstrated
the modest efficacy of endometriosis ablation in increasing the pregnancy rate in
infertile women while drugs suppressing ovulation are of no benefit to infertile
women with endometriosis. Although the largest body of evidence available
suggests that IVF success declines in repeated ART cycles, an accurate estimate
of the true success rate in the 'nth' cycle of IVF treatment is not possible.
Similarly little is still known of the reasons for the overall low continuation
rates with IVF treatment.
PMID- 10686228
TI - Ureteral injuries after laparoscopic hysterectomy.
PMID- 10686229
TI - The clinical benefits of recombinant gonadotrophins.
PMID- 10686231
TI - March 2000: this Month's highlights
PMID- 10686230
TI - The "new drugs" and the research we haven't done.
PMID- 10686232
TI - Emergency psychiatry: extrapyramidal side effects in the psychiatric emergency
service.
PMID- 10686233
TI - Datapoints: psychiatric care expenditures and length of stay: trends in
industrialized countries.
PMID- 10686234
TI - Practical geriatrics: directions for research and policy on schizophrenia and
older adults: summary of the GAP committee report.
PMID- 10686235
TI - Web sites worth watching
PMID- 10686236
TI - Rehab rounds: overcoming barriers to individualized psychosocial rehabilitation
in an acute treatment unit of a state hospital.
AB - Psychiatric rehabilitation begins during the acute stages of a psychiatric
disorder and continues throughout the person's lifetime, with the types of
services flexibly keyed to the person's phase of illness, needs, and personal
goals. During periods of relapse and exacerbation of symptoms, when
hospitalization is often required, psychiatric rehabilitation should include the
following five objectives: * Clarify how the person's own goals in life, such as
a desire for more self-control, freedom of choice, privacy, and time with friends
and family, can be served by inpatient treatment and symptom stabilization. *
Educate the patient about the nature of his or her illness and how medications
work to restore self-control. * Teach the patient about side effects and self
monitoring and negotiating about medication and its effects in a collaborative
way with the psychiatrist and other members of the treatment team. * Connect with
the family or other natural supports that the person has in the community. *
Enable the patient to make appropriate aftercare plans for residential and
continuing treatment needs after discharge. When rehabilitation is viewed from
the vantage point of these objectives, the inextricable interweaving of
"treatment" with "rehabilitation" becomes clear. Treatment and rehabilitation are
two sides of the same. It is much easier to integrate psychiatric rehabilitation
into more traditional methods of treatment than it is to reorganize a treatment
program or facility so that it blends rehabilitation with prevailing treatment
imperatives of pharmacotherapy, supervision, and security and safety. In previous
Rehab Rounds columns, we have described examples of creative methods for bringing
the principles and practices of psychiatric rehabilitation into the treatment
milieu (1,2,3). Faced with regulatory criticism from governmental agencies, Dr.
Dhillon and his colleagues at Eastern State Hospital in Williamsburg, Virginia,
launched a vigorous initiative to bring psychiatric rehabilitation into the
forefront of their clinical enterprise. To enable readers to learn from their
successful experience and adapt some of the administrative and clinical
procedures that worked in Virginia, Dr. Dhillon and Ms. Dollieslager describe the
operational details of their odyssey. We believe that their effectiveness in
changing a traditional institution can be duplicated in many other places-in
units within general hospitals or other community-based settings-as well as in
state psychiatric hospitals, where acute treatment has been limited to
pharmacotherapy and recreational and diversional activities.
PMID- 10686237
TI - The new drugs (chlorpromazine & reserpine): administrative aspects. 1956.
AB - The article on the new drugs reprinted below appeared in the February 1956 issue
of Mental Hospitals. It is based on a discussion held during the Seventh Mental
Hospital Institute in October 1955 in Washington, D.C. Chlorpromazine and
reserpine had been available in the United States less than two years when the
institute participants met to discuss how their hospitals were coping with the
demands of the new treatments. In a commentary and analysis beginning on page
333, Robert Cancro, M.D., considers the broader impact of the introduction of
neuroleptics and examines the concerns of the 1956 institute participants in the
context of today.
PMID- 10686238
TI - The release bandwagon.
AB - The essay below, published in the Dr. Whatsisname column in the June 1959 issue
of Mental Hospitals, takes a wry look at the wholesale discharge of patients from
mental hospitals following the introduction of the new drugs. (See "The New Drugs
(Chlorpromazine & Reserpine): Administrative Aspects" on page 327 and Dr. Robert
Cancro's commentary and analysis on page 333.) The Dr. Whatsisname column
appeared regularly in the journal for almost 14 years before it was discontinued
in 1970 and the identity of its author formally revealed: Henry A. Davidson,
M.D., a hospital administrator in New Jersey. Washington artist Ralph Robinson
drew the cartoons.
PMID- 10686239
TI - The introduction of neuroleptics: a psychiatric revolution.
AB - In the commentary below, Robert Cancro, M.D., discusses the article on page 327,
reprinted from the February 1956 issue of Mental Hospitals, describing how
hospitals were dealing with clinical and administrative issues surrounding the
use of neuroleptic drugs. Although Dr. Cancro considers the introduction of
neuroleptics one of the great psychiatric revolutions of the 20th century, he
believes that the changes in patient care and treatment following their
introduction have not always been positive.
PMID- 10686240
TI - Psychiatric practice variations in the diagnosis and treatment of major
depression.
AB - OBJECTIVE: Practice variations in the diagnosis, treatment, and outcomes of
patients with major depression were examined within six psychiatric practices
participating in a national outcomes-management project. METHODS: Six of 20
psychiatric clinics met selection criteria for this study and provided a database
of 5, 106 patients. Patients completed the BASIS-32, the Short-Form-36 Health
Survey, and a Beginning Services Survey. Treatment information was also obtained
directly from the clinician or through a medical record review. RESULTS: Although
73.1 to 77 percent of patients screened positive for a depressive disorder, only
18.5 to 36.8 percent were diagnosed with major depression (p<.001). Between 39
and 72 percent of patients received psychotropic medications, a significant
difference across sites (p<.001). In addition, the number of psychotherapy
sessions was significantly different across sites (p<.001). CONCLUSIONS: Patient
care varies considerably across psychiatric practices, a finding that is
particularly relevant for developers of performance indicators and risk
adjustment strategies for mental health.
PMID- 10686241
TI - Patient-based health status assessments in an outpatient psychiatry setting.
AB - OBJECTIVE: The reliability, validity, and feasibility of the routine use of a
generic health status instrument, the Short-Form-36 Health Survey (SF-36), were
examined in a psychiatric outpatient clinic of a general hospital. METHODS: The
sample comprised 411 patients referred to an outpatient psychiatry department
between April 1994 and March 1995. They filled out the SF-36 along with their
admission forms. Scores and reports were generated, and the results were returned
to the charts and used at weekly clinical conference discussions. Feasibility was
evaluated using subjective and objective data on administration of the
instrument, its psychometric properties, and costs. Results from the outpatient
psychiatry patients were compared with those from patients scheduled for elective
surgery and a healthy normative sample. RESULTS: Routine administration of the SF
36 was successfully achieved with minimal resistance from staff and patients. The
SF-36 provided reliable and valid data. As predicted, patients with emotional
disorders scored lower, indicating more impairment, on scales measuring mental
health than did the elective surgery patients and the normative sample. However,
the psychiatric patients' scores on the physical health scale were lower than
clinicians expected. Compared with the elective surgery patients, the psychiatric
patients were less impaired on only the physical functioning and bodily pain
scales; no difference was found between the two groups in role functioning due to
physical problems. CONCLUSIONS: Routine use of the SF-36 in a general hospital
psychiatric outpatient clinic was feasible, and the results were reliable, valid,
and helpful to clinicians. Psychiatric patients' significantly lower scores in
physical health and social and role functioning provided additional information
about their difficulties.
PMID- 10686242
TI - A self-report symptom and problem rating scale to increase inpatients'
involvement in treatment.
AB - OBJECTIVE: The study sought to determine whether psychiatric inpatients who
completed a self-report symptom and problem rating scale on admission and
reviewed the results with a clinician would perceive at discharge that they had
been more involved in their treatment than patients who did not complete the
scale. METHODS: In a quasiexperimental design, 109 inpatients were assigned to
one of three groups. Patients in one group met individually with a psychiatric
resident to review their responses to the Behavior and Symptom Identification
Scale (BASIS-32), a self-report outcome assessment tool. Patients' views of their
difficulties were then used by the treatment team to build a therapeutic alliance
and to inform treatment planning. The remaining two groups received treatment as
usual by either a psychiatric resident or an attending psychiatrist. Patients'
perceived involvement in decisions about their treatment, perceptions of other
aspects of care, and treatment outcome were compared. RESULTS: Patients in the
intervention group rated their involvement in decisions about their treatment
significantly higher than patients in either of the comparison groups. Patients
in the intervention group more frequently reported that they were treated with
respect and dignity by the staff than did patients in the comparison group
treated by attending psychiatrists. Compared with patients treated by attending
psychiatrists, patients treated by residents, whether they received the
intervention or not, were more likely to say that they would recommend the
hospital to others. Treatment outcome did not differ among the groups.
CONCLUSIONS: The results suggest that an outcome assessment tool can be used to
engage patients in the treatment process.
PMID- 10686243
TI - Use of nursing homes in the care of persons with severe mental illness: 1985 to
1995.
AB - OBJECTIVE: The study examined patterns of care for persons with mental illness in
nursing homes in the United States from 1985 to 1995. During that period resident
populations in public mental hospitals declined, and legislation aimed at
diverting psychiatric patients from nursing homes was enacted. METHODS: Estimates
of the number of current residents with a mental illness diagnosis and those with
a severe mental illness were derived from the 1985 and 1995 National Nursing Home
Surveys and the 1987 and 1996 Medical Expenditure Surveys. Trends by age group
and changes in the mentally ill population over this period were assessed.
RESULTS: The number of nursing home residents diagnosed with dementia-related
illnesses and depressive illnesses increased, but the number with schizophrenia
related diagnoses declined. The most substantial declines occurred among
residents under age 65; more than 60 percent fewer had any primary psychiatric
diagnosis or severe mental illness. CONCLUSIONS: These findings suggest a reduced
role for nursing homes in caring for persons with severe mental illness,
especially those who are young and do not have comorbid physical conditions.
Overall, it appears that nursing homes play a relatively minor role in the
present system of mental health services for all but elderly persons with
dementia.
PMID- 10686244
TI - Clinical and ethical implications of impaired executive control functions for
patient autonomy.
AB - The authors identify the clinical and ethical implications of impaired executive
control functions for patient autonomy. Executive control functions are processes
that orchestrate relatively simple ideas, movements, or actions into complex goal
directed behavior, and impairments in these functions are becoming more common as
the population ages. The authors examine difficulties that individuals with
impaired executive control functions may have in making treatment decisions and
describe a practical, ethically justified framework for making treatment
decisions for patients with impairments in these functions. Three components of
autonomy are identified-intentionality, understanding, and voluntariness.
Intentionality and voluntariness are especially affected by impaired executive
control functions. Impairments of these aspects of autonomy may often be
overlooked when only traditional mental status examinations are employed, with
adverse consequences for the health of patients wrongly thought to possess intact
ability to make and carry out plans of care. Two case vignettes illustrate the
complexities faced by clinicians intervening with patients who have deficits in
decision-making capacity caused by impaired executive control functions.
PMID- 10686245
TI - The impact of caseload on the personal efficacy of mental health case managers.
AB - OBJECTIVE: The relationship between caseload size and self-perceived clinical
effectiveness of mental health case managers was explored. METHODS: A 17-item
instrument developed for the study, the Case Manager Personal Efficacy Scale
(CMPES), was completed by 300 community mental health case managers in Australia.
Efficacy scores were examined in relation to caseload size and to respondents'
scores on the General Health Questionnaire. RESULTS: The CMPES was sensitive to
changes in caseload size. Case managers with larger caseloads reported lower
performance in a range of core role activities. Larger caseload had a weak but
significant negative association with general well-being as measured by the
General Health Questionnaire. CONCLUSIONS: Caseload size had a significant impact
on the self-perceived role performance of mental health case managers. The CMPES
is a reliable measure of case manager personal efficacy that is sensitive to
variation in work context.
PMID- 10686246
TI - Effects of an outreach intervention on use of mental health services by veterans
with posttraumatic stress disorder.
AB - OBJECTIVE: The study examined the effectiveness of an outreach intervention
designed to increase access to mental health treatment among veterans disabled by
chronic posttraumatic stress disorder (PTSD) and identified patient-reported
barriers to care associated with failure to seek the treatment offered. METHODS:
Participants were 594 male Vietnam veterans who were not enrolled in mental
health care at a Department of Veterans Affairs (VA) medical center but who were
receiving VA disability benefits for PTSD. Half the sample was randomly assigned
to an outreach intervention, and the other half was assigned to a control group.
Veterans in the intervention group received a mailing that included a brochure
describing PTSD treatment available at an urban VA medical center, along with a
letter informing them about how to access care. Participants in the intervention
group were subsequently telephoned by a study coordinator who encouraged them to
enroll in PTSD treatment and who administered a survey assessing barriers to
care. RESULTS: Veterans in the intervention group were significantly more likely
than those in the control group to schedule an intake appointment (28 percent
versus 7 percent), attend the intake (23 percent versus 7 percent), and enroll in
treatment (19 percent versus 6 percent). Several patient-identified barriers were
associated with failure to seek VA mental health care, such as personal
obligations that prevented clinic attendance, inconvenient clinic hours, and
current receipt of mental health treatment from a non-VA provider. CONCLUSIONS:
Utilization of mental health services among underserved veterans with PTSD can be
increased by an inexpensive outreach intervention, which may be useful with other
chronically mentally ill populations.
PMID- 10686247
TI - Burnout among relatives of psychiatric patients attending psychoeducational
support groups.
AB - OBJECTIVE: The effectiveness of family interventions may be improved by
concentrating on elements of objective burden that best predict subjective
burden. The relationship between subjective burden and objective burden was
investigated among caregivers of patients with serious mental illness in the
Netherlands who were attending psychoeducational support groups. METHODS: The
study used pretest data from an intervention study in which psychoeducational
family support groups in the Netherlands were evaluated. A total of 164
participants from 19 psychoeducational groups organized by nine community mental
health centers completed the Dutch translation of the Maslach Burnout Inventory
and the Involvement Evaluation Questionnaire. Regression analyses were conducted,
with elements of subjective burden as dependent variables and elements of
objective burden, demographic characteristics, and characteristics of the
patient's disorder as predictors. RESULTS: Burden in general and emotional
exhaustion were the aspects of subjective burden best predicted by objective
burden. In two regression models, objective burden together with the other
predictors explained 57 percent and 54 percent of the variance in subjective
burden. Two aspects of objective burden-strain on the relationship with the
patient and ability to cope with the patient's behavior-were related to almost
all the investigated aspects of subjective burden. CONCLUSIONS: Strong evidence
was found for the relationship between objective and subjective burden and for
the hypothesis that particular elements of objective burden contribute more to
subjective burden than others. The findings suggest that psychoeducation should
concentrate on helping relatives cope with the strain on the relationship with
the patient and on improving their ability to cope with the patient's behavior.
PMID- 10686248
TI - Use of health services by men with and without antisocial personality disorder
who are alcohol dependent.
AB - In a sample of 104 medically stable male veterans with alcohol dependence, rates
of health service utilization were compared for 48 patients with a primary
diagnosis of antisocial personality disorder and 56 patients without this
diagnosis. Patients were diagnosed using DSM-IV lifetime criteria; previous
utilization of health services was based on self-reports. Although a similar
proportion of both groups reported previous service use, patients with antisocial
personality disorder reported using more substance abuse treatment services than
those with a primary diagnosis of alcohol dependence. Between-group multiple
regression analysis showed that an earlier age at onset of alcoholism and a
history of a comorbid substance-induced mental disorder best predicted higher
rates of use of substance abuse treatment.
PMID- 10686249
TI - Community placement of long-stay psychiatric patients in northern Finland.
AB - Rapid deinstitutionalization occurred in Finland in the 1990s, a decade later
than in many other Western countries. A four-year follow-up study in northern
Finland examined community placements of 253 long-stay psychiatric inpatients
after deinstitutionalization in 1992 and at follow-up at the end of 1995. About
70 percent of the patients were discharged. Only 15 percent were able to live
outside the hospital without continuous support. No patient was homeless at
follow-up. Being unmarried, living in the city of Oulu, and having greater
severity of illness were associated with hospitalization at follow-up. The
results showed that long-stay patients are dependent on considerable support.
Alternative residential facilities have made deinstitutionalization possible.
PMID- 10686250
TI - Posttraumatic stress among young children after the death of a friend or
acquaintance in a terrorist bombing.
AB - The effects of traumatic loss on children who reported a friend or acquaintance
killed in the 1995 Oklahoma City bombing of a federal office building were
examined. Twenty-seven children who lost a friend or acquaintance and 27
demographically matched controls were assessed eight to ten months after the
bombing. All but three of the children continued to experience posttraumatic
stress symptoms. Those who lost a friend watched significantly more bombing
related television coverage than those without losses. Those who lost a friend
had significantly more posttraumatic stress symptoms at the time of the
assessment than those who lost an acquaintance. Parents and those working with
children should be alert to the impact of loss even when it involves
nonrelatives.
PMID- 10686251
TI - No forced drugging.
PMID- 10686252
TI - No forced drugging
PMID- 10686253
TI - Managing aggressive psychotic patients.
PMID- 10686255
TI - Managing aggressive psychotic patients
PMID- 10686254
TI - Managing aggressive psychotic patients.
PMID- 10686256
TI - Combating stigma by redefining it.
PMID- 10686257
TI - Managing aggressive psychotic patients.
PMID- 10686258
TI - Ethics and managed care.
PMID- 10686260
TI - Ethics and managed care
PMID- 10686259
TI - Combating stigma by redefining It
PMID- 10686261
TI - Vagus nerve stimulation for treatment-resistant depression.
PMID- 10686263
TI - Vagus nerve stimulation: a new tool for brain research and therapy.
AB - Biological psychiatry has a long history of using somatic therapies to treat
neuropsychiatric illnesses and to understand brain function. These methods have
included neurosurgery, electroconvulsive therapy, and, most recently,
transcranial magnetic stimulation. Fourteen years ago researchers discovered that
intermittent electrical stimulation of the vagus nerve produces inhibition of
neural processes, which can alter brain electrical activity and terminate
seizures in dogs. Since then, approximately 6000 people worldwide have received
vagus nerve stimulation for treatment-resistant epilepsy. We review the
neurobiology and anatomy of the vagus nerve and provide an overview of the vagus
nerve stimulation technique. We also describe the safety and potential utility of
vagus nerve stimulation as a neuroscience research tool and as a putative
treatment for psychiatric conditions. Vagus nerve stimulation appears to be a
promising new somatic intervention that may improve our understanding of brain
function and has promise in the treatment of neuropsychiatric disorders.
PMID- 10686262
TI - Vagus nerve stimulation (VNS) for treatment-resistant depressions: a multicenter
study.
AB - BACKGROUND: Vagus Nerve Stimulation (VNS) delivered by the NeuroCybernetic
Prosthesis (NCP) System was examined for its potential antidepressant effects.
METHODS: Adult outpatients (n = 30) with nonpsychotic, treatment-resistant major
depressive (n = 21) or bipolar I (n = 4) or II (n = 5; depressed phase) disorders
who had failed at least two robust medication trials in the current major
depressive episode (MDE) while on stable medication regimens completed a baseline
period followed by NCP System implantation. A 2-week, single-blind recovery
period (no stimulation) was followed by 10 weeks of VNS. RESULTS: In the current
MDE (median length = 4.7 years), patients had not adequately responded to two (n
= 9), three (n = 2), four (n = 6), or five or more (n = 13) robust antidepressant
medication trials or electroconvulsive therapy (n = 17). Baseline 28-item
Hamilton Depression Rating Scale (HDRS(28)) scores averaged 38.0. Response rates
(> or =50% reduction in baseline scores) were 40% for both the HDRS(28) and the
Clinical Global Impressions-Improvement index (score of 1 or 2) and 50% for the
Montgomery-Asberg Depression Rating Scale. Symptomatic responses (accompanied by
substantial functional improvement) have been largely sustained during long-term
follow-up to date. CONCLUSIONS: These open trial results suggest that VNS has
antidepressant effects in treatment-resistant depressions.
PMID- 10686264
TI - Neurobiology of the obsessive-compulsive spectrum disorders.
AB - Advances in obsessive-compulsive disorder (OCD) research have led to increased
attention to a range of disorders with possibly overlapping phenomenological and
neurobiological features; the so-called OCD spectrum disorders. This article
briefly reviews neurobiological data relevant to the construction of an OCD
spectrum, including neurochemical, neuroanatomic, genetic, neuroimmunology, and
animal studies. OCD and related disorders may be heterogenous conditions, and the
neurobiology of many putative OCD spectrum disorders has not been well studied.
Nevertheless, a gradual accumulation of neurobiological data has provided a
number of exciting, and partially overlapping, approaches to an hypothesized OCD
spectrum.
PMID- 10686265
TI - Reduced glutamate in the anterior cingulate cortex in depression: an in vivo
proton magnetic resonance spectroscopy study.
AB - BACKGROUND: Functional imaging studies suggest a specific role of the anterior
brain regions in the pathogenesis of major depression. The aim of this study was
to evaluate possible neurochemical alterations in the frontomesial cortex in
patients with major depressive episode using in vivo proton magnetic resonance
spectroscopy ((1)H-MRS). METHODS: Single voxel (1)H-MRS was performed in 19
patients with major depressive episodes and 18 age-matched healthy controls
within the anterior cingulate cortex and the parietal white matter. Absolute
concentrations were estimated for N-acetyl-aspartate, choline-containing
compounds, total creatine, myo-inositol, unresolved glutamate and glutamine (Glx)
and glutamate alone (Glu). Voxel composition was analyzed by image segmentation
into cerebrospinal fluid (CSF), grey and white matter. RESULTS: MANOVA test for
Glx and Glu using age, percent CSF and percent grey matter contribution as
covariates yielded a significant group effect within the anterior cingulate due
to decrease of Glx in patients (-10.4%, p =.013). Considering only severely
depressed patients, both Glx and Glu (-14.3%, p =.03) showed a significant
decrease. There was no significant group effect for the neuronal marker NAA,
creatine, choline or myo-inositol in either localization. CONCLUSIONS: This study
suggests a possible role of altered glutamatergic neurotransmission within the
anterior cingulate in the pathogenesis of mood disorders. The otherwise
unremarkable findings of major brain metabolites confirms lack of
neurodegenerative or membrane metabolic changes in major depression.
PMID- 10686266
TI - Repetitive transcranial magnetic stimulation is as effective as electroconvulsive
therapy in the treatment of nondelusional major depressive disorder: an open
study.
AB - BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS), a new method for
the stimulation of the central nervous system, is being proposed as a potential
new treatment in patients with major depressive disorder (MDD). We tested the
hypothesis that rTMS would be as effective as electroconvulsive therapy (ECT) in
patients with MDD. METHODS: Forty patients with MDD referred for ECT were
randomly assigned to either ECT or rTMS. Repetitive transcranial magnetic
stimulation was performed at 90% power of the motor threshold. The stimulation
frequency was 10 Hz for either 2 sec (first eight patients) or 6 sec (final 12
patients) for 20 trains. Patients were treated for up to 20 treatment days.
Electroconvulsive therapy was performed according to standard protocols. RESULTS:
Overall patients responded best to ECT (chi(2) = 3.8, p <.05). Patients with MDD
and psychosis responded significantly better to ECT (chi(2) = 9.2, p <. 01),
whereas MDD patients without psychosis responded similarly to both treatments
(chi(2) = 0.0, ns). The analysis of variance with repeated measures of clinical
variables for the whole sample revealed significant treatment effects for both
groups; however, interaction between group and treatment was seen only for the
Global Assessment of Function and the Sleep assessment. When the psychosis
nonpsychosis grouping was considered, patients with psychosis responded
dramatically better to ECT in all assessments, whereas those without psychosis
responded similarly to both treatments. CONCLUSIONS: Overall ECT was a more
potent treatment for patients with MDD, this being particularly evident in
patients with MDD and psychosis; however, in patients with MDD without psychosis
the effects of rTMS were similar to those of ECT. The results we report are
encouraging and support an important role for rTMS in the treatment of severe
MDD; however, additional blinded studies are needed to precisely define this
role.
PMID- 10686267
TI - Transcranial magnetic stimulation (TMS) in controlled treatment studies: are some
"sham" forms active?
AB - BACKGROUND: Carefully designed controlled studies are essential in further
evaluating the therapeutic efficacy of transcranial magnetic stimulation (TMS) in
psychiatric disorders. A major methodological concern is the design of the "sham"
control for TMS. An ideal sham would produce negligible cortical stimulation in
conjunction with a scalp sensation akin to real treatment. Strategies employed so
far include alterations in the position of the stimulating coil, but there has
been little systematic study of their validity. In this study, we investigated
the effects of different coil positions on cortical activation and scalp
sensation. METHODS: In nine normal subjects, single TMS pulses were administered
at a range of intensities with a "figure eight" coil held in various positions
over the left primary motor cortex. Responses were measured as motor-evoked
potentials in the right first dorsal interosseus muscle. Scalp sensation to TMS
with the coil in various positions over the prefrontal area was also assessed.
RESULTS: None of the coil positions studied met the criteria for an ideal sham.
Arrangements associated with a higher likelihood of scalp sensation were also
more likely to stimulate the cortex. CONCLUSIONS: The choice of a sham for TMS
involves a trade-off between effective blinding and truly inactive "stimulation."
Further research is needed to develop the best sham condition for a range of
applications.
PMID- 10686268
TI - A randomized clinical trial of repetitive transcranial magnetic stimulation in
the treatment of major depression.
AB - BACKGROUND: Multiple groups have reported on the use of repetitive transcranial
magnetic stimulation (rTMS) in treatment-resistant major depression. The purpose
of this study is to assess the efficacy of rTMS in unmedicated, treatment
resistant patients who meet criteria for major depression. METHODS: Depressed
subjects, who had failed to respond to a median of four treatment trials, were
assigned in a randomized double-blind manner to receive either active (n = 10; 20
2-sec trains of 20 Hz stimulation with 58-sec intervals; delivered at 80% motor
threshold with the figure-of-eight coil positioned over the left dorsolateral
prefrontal cortex) or sham (n = 10; similar conditions with the coil elevated and
angled 45 degrees tangentially to the scalp) rTMS. These sequences were applied
during 10 consecutive weekdays. Continuous electroencephalogram sampling and
daily motor threshold determinations were also obtained. RESULTS: The group mean
25-item Hamilton Depression Rating Scale (HDRS) score was 37.2 (+/- 2.0 SEM)
points. Adjusted mean decreases in HDRS scores were 14.0 (+/- 3.7) and 0.2 (+/-
4.1) points for the active and control groups, respectively (p <.05). One of 10
subjects receiving active treatment demonstrated a robust response (i.e., HDRS
decreased from 47 to 7 points); three other patients demonstrated 40-45%
decreases in HDRS scores. No patients receiving sham treatment demonstrated
partial or full responses. CONCLUSIONS: A 2-week course of active rTMS resulted
in statistically significant but clinically modest reductions of depressive
symptoms, as compared to sham rTMS in a population characterized by treatment
resistance.
PMID- 10686269
TI - Ultradian rhythms and temporal coherence in sleep EEG in depressed children and
adolescents.
AB - BACKGROUND: It has been suggested that a primary ultradian (80-120 minute) rhythm
disturbance in EEG underlies sleep abnormalities in adults with depression. The
present study evaluated ultradian rhythm disturbances in childhood and adolescent
depression. METHODS: Sleep macroarchitecture and temporal coherence in
quantitative EEG rhythms were investigated in 50 medication-free outpatients with
major depression (25 children and 25 adolescents) and 15 healthy normal controls
(5 children and 10 adolescents). RESULTS: Few of the macroarchitectural measures
showed significant group effects. In fact, age and sex effects were stronger than
disease-dependent components. Temporal coherence of EEG rhythms during sleep did
differentiate those with MDD from controls. Both depressed children and
adolescents had lower intrahemispheric coherence, whereas interhemispheric was
only lower in depressed adolescents in comparison with controls. Gender
differences were evident in adolescents, but not children, with MDD with lowest
interhemispheric coherence in adolescent girls. CONCLUSIONS: These findings are
in keeping with increased risk for depression in females beginning at adolescence
and extending throughout adulthood. It was suggested that low temporal coherence
in depression reflects a disruption in the fundamental basic rest-activity cycle
of arousal and organization in the brain that is strongly influenced by gender.
PMID- 10686270
TI - Antidepressant effects of ketamine in depressed patients.
AB - BACKGROUND: A growing body of preclinical research suggests that brain glutamate
systems may be involved in the pathophysiology of major depression and the
mechanism of action of antidepressants. This is the first placebo-controlled,
double-blinded trial to assess the treatment effects of a single dose of an N
methyl-D-aspartate (NMDA) receptor antagonist in patients with depression.
METHODS: Seven subjects with major depression completed 2 test days that involved
intravenous treatment with ketamine hydrochloride (.5 mg/kg) or saline solutions
under randomized, double-blind conditions. RESULTS: Subjects with depression
evidenced significant improvement in depressive symptoms within 72 hours after
ketamine but not placebo infusion (i.e., mean 25-item Hamilton Depression Rating
Scale scores decreased by 14 +/- SD 10 points vs. 0 +/- 12 points, respectively
during active and sham treatment). CONCLUSIONS: These results suggest a potential
role for NMDA receptor-modulating drugs in the treatment of depression.
PMID- 10686271
TI - Body temperature and mood variations during forced desynchronization in winter
depression: a preliminary report.
AB - BACKGROUND: It has been suggested that certain abnormalities (e.g., in phase or
amplitude) of the circadian pacemaker underlie seasonal affective disorder.
METHODS: One male seasonal affective disorder patient (blind to the study design)
participated in two 120-hour forced desynchrony experiments and was subjected to
six 20-hour days, once during a depressive episode and once after recovery. Core
body temperature was continuously measured. During wakefulness, the Adjective
Mood Scale was completed at 2-hour intervals. RESULTS: Sleep-wake as well as
pacemaker-related variations of mood were found, both when the subject was
depressed and when he was euthymic. Compared with recovery, during the depressive
episode the circadian temperature minimum and the circadian mood variation showed
phase delays of approximately 1 and 2 hours, respectively. CONCLUSIONS: The data
of this first seasonal affective disorder patient, participating in forced
desynchrony experiments, may indicate a phase delay of the circadian pacemaker
during a seasonal affective disorder episode.
PMID- 10686272
TI - Glutamine synthetase in experimental meningitis: increased ratio of the subunits
3 and 2 may indicate enhanced activity.
AB - Glutamine synthetase (GS) activity is higher in the neocortex but not in the
hippocampal formation of rabbit brain during Streptococcus pneumoniae meningitis
compared to the respective brain region of uninfected control animals. One
dimensional polyacrylamide gel electrophoresis (1D-SDS-PAGE) revealed an apparent
molecular mass (M(r)) of 44000 Dalton (Da) for GS from rabbit brain. After two
dimensional gel electrophoresis (2D-PAGE), followed by Coomassie-blue staining,
GS separated into three distinct spots (S1, S2, S3). One additional spot (S4)
occurred on the immunoblot. All four GS spots exhibited the same M(r) (44000 Da),
but differed in their isoelectric points. Densitometric evaluation of the two
dimensional maps revealed a strong increase of optical density (OD) of S3 in the
frontal cortex of infected animals. The calculated OD ratio S3/S2 in the frontal
cortex from rabbits with meningitis was 1.75+/-0.68 (mean+/-standard deviation).
Compared to controls (0. 85+/-0.39), this value was significantly increased
(p=0.0006). In the hippocampal formation, the ratio S3/S2 was nearly unchanged
during meningitis. It is suggested that the ratio S3/S2 may indicate a
neuroprotective feature of rabbit brain during meningitis since neuronal
apoptosis occurs only in the dentate gyrus and not in the frontal cortex.
PMID- 10686273
TI - Performance of the enhanced Abbott AxSYM cardiac troponin I reagent in patients
with heterophilic antibodies.
AB - The presence of heterophilic antibodies in the serum of a small subpopulation of
individuals continues to cause false results for modern-day immunoassays. In
order to determine the frequency of heterophilic antibody (HA)-related false
positives within our population of positive cardiac troponin I (cTnI) patients,
we assayed 200 samples using the original in-house cTnI assay (Abbott AxSYM) and
the Bayer ACS:180 cTnI, which we had previously observed to be more effective at
blocking HA interference. Four samples were identified as false positives based
on discordant results between the two assays, as well as the correction of the
false positives by treatment of the samples with heterophilic antibody blocking
reagent (HBR). An 'enhanced' version of the AxSYM cTnI reagent was designed to
greatly reduce or eliminate HA interference, and has now replaced the original
reagents. The present study shows that the enhanced reagent significantly reduced
or eliminated much of the HA interference. Comparative studies between the
enhanced cTnI reagent and the original Abbott AxSYM cTnI reagent showed excellent
correlation and equivalent diagnostic concordance, when HA samples were excluded
from the analysis.
PMID- 10686274
TI - Proteolytic activation of purified human procarboxypeptidase U.
AB - Carboxypeptidase U (CPU, EC 3.4.17.20) is a recently described basic
carboxypeptidase which circulates in plasma as an enzymatically inactive
precursor procarboxypeptidase U (proCPU), also known as plasma carboxypeptidase B
precursor or thrombin activatable fibrinolysis inhibitor (TAFI). The activation
of the zymogen proceeds through a proteolytic cleavage at Arg-92. The active form
- CPU - is able to retard the initial phase of fibrinolysis by cleaving C
terminal lysine residues exposed on fibrin partially degraded by the action of
plasmin. These C-terminal lysine residues are essential for the high affinity
binding of plasminogen to fibrin and the subsequent activation to plasmin. In
this report, the activation of purified human proCPU was studied using trypsin
and some key proteases of the coagulation and fibrinolytic cascade, i.e.,
kallikrein, plasmin and thrombin. The most efficient activation is obtained in
the presence of thrombin in complex with thrombomodulin. After in vitro
activation, CPU is unstable at 37 degrees C (T(1/2)=15 min). Its stability can be
improved dramatically using lower temperatures.
PMID- 10686275
TI - Improved assay for fecal calprotectin.
AB - Fecal calprotectin is a marker of inflammatory and neoplastic disease in the
lower gastrointestinal tract. A new fecal sample preparation procedure for the
measurement of calprotectin has been developed, with higher calprotectin yield
and lower contamination risk. Changes in the new method compared to the original
[Roseth AG, Fagerhol MK, Aadland E, Schonsby H. Assessment of the neutrophil
dominating protein calprotectin in feces. A methodologic study. Scand J
Gastroenterol 1992;27(9):793-798] are smaller sample size, higher dilution of the
sample, presence of dissociating agents in the extraction solution and procedure
performed in closed disposable tubes. The extraction yield was 78% (41-100%) of
total calprotectin, giving an overall five-fold increase compared to the original
method. Samples with high calprotectin values were increased to a slightly higher
degree, than low calprotectin samples, thus improving the separation between high
and low calprotectin levels. Median calprotectin level in healthy subjects was 26
microg/g. Pathological samples with pancolitis showed levels up to 30000
microg/g. The mean C.V. (coefficient of variation) in blended feces was lower
than that of unblended, suggesting uneven distribution of calprotectin. However,
no significant difference between spot measurements was found when five samples
from each of 47 stools were measured. Thus measurements of calprotectin in fecal
samples were accurate and reproducible. No interference with foods or relevant
oral pharmaceuticals or nutraceuticals was found.
PMID- 10686276
TI - Evaluation of intrinsic and routine quality of serum total magnesium measurement.
AB - We investigated the intrinsic (as delivered by the manufacturer) and routine
quality of four systems for measurement of serum total magnesium (t-Mg(2+)) by
method comparison with an ion chromatography reference method. The results of the
study were interpreted on the basis of analytical quality specifications derived
from the biological variation of t-Mg(2+), expanded by the analytical uncertainty
of the reference measurements. This resulted in limits for systematic error of
2.1% and for total error of 4.3%. The study demonstrated that those limits were
challenging for all routine systems. Most of them met the total error criterium
just borderline and one showed a considerable systematic error (-5.2%).
Concerning the measurement quality in the routine laboratories, the study showed
that many were unable to preserve the intrinsic quality of the respective
manufacturer. Consequently, loss of system performance in the routine laboratory
mostly led to violation of the analytical specifications. Most strikingly, the
study revealed enormous quality differences between routine laboratories. This
indicates that, still, many routine laboratories do not make adequate use of
currently available internal and external quality control tools. Moreover, some
laboratories considerably expanded the high end of the reference interval,
thereby reducing the diagnostic potential of t-Mg(2+).
PMID- 10686277
TI - Prebeta1-high-density lipoprotein (prebeta1-HDL) concentration can change with
low-density lipoprotein-cholesterol (LDL-C) concentration independent of
cholesteryl ester transfer protein (CETP).
AB - To clarify whether prebeta1-high-density lipoprotein (prebeta1-HDL) concentration
changes with low-density lipoprotein-cholesterol (LDL-C) concentration
independent of cholesteryl ester transfer protein (CETP), we determined prebeta1
HDL concentration by native two-dimensional gel electrophoresis in 58 subjects
with normal triglyceride and HDL-cholesterol concentrations. We also measured LDL
C and CETP concentrations. In 17 subjects, a second blood sample was taken 1-6
months after the first. We found that prebeta1-HDL concentration was positively
correlated with LDL-C concentration (r=0.529, P<0.0001) and with CETP mass
(r=0.398, P<0.01). In 17 patients, Deltaprebeta1-HDL was positively correlated
with DeltaLDL-C (r=0.635, P<0.01), but not with DeltaCETP mass (r=0.275). In
conclusion, prebeta1-HDL concentration changes with LDL-C concentration
independent of CETP. These results suggest that prebeta1-HDL concentration may
reflect the balance between several regulatory factors, including LDL-C and CETP
concentrations.
PMID- 10686278
TI - Plasma levels of coenzyme Q(10), vitamin E and lipids in uremic patients on
conservative therapy and hemodialysis treatment: some possible biochemical and
clinical implications.
AB - Coenzyme Q(10) (CoQ(10)), vitamin E, total cholesterol, HDL-cholesterol (HDLC)
and triglycerides were measured in the plasma of 62 patients with kidney failure,
46 under hemodialysis treatment and 16 under conservative therapy, and 95
controls. The sum of LDL-cholesterol (LDL-C) and VLDL-cholesterol (VLDL-C) was
also calculated for each patient. The ratio CoQ(10)/LDL-C+VLDL-C in both
conservative therapy and hemodialysis populations was significantly lower
(P<0.001) compared with normal controls and remained unchanged after the dialysis
treatment. On the contrary the ratio vitamin E/LDL-C+VLDL-C was normal but
decreased significantly (P<0.02) after each dialysis. Since coenzyme Q is the
main inhibitor of the prooxidant action of vitamin E, it was hypothesized that
its decrease in both the populations examined could make the lipoproteins of
these patients more vulnerable to a peroxidative attack.
PMID- 10686279
TI - Stereodifferentiation of 3-hydroxyisobutyric- and 3-aminoisobutyric acid in human
urine by enantioselective multidimensional capillary gas chromatography-mass
spectrometry.
AB - The chiral metabolites 3-hydroxyisobutyric acid (HIBA) and 3-aminoisobutyric acid
(AIBA) are intermediates in the pathways of L-valine and thymine and play an
important role in the diagnosis of the very rare inherited metabolic diseases 3
hydroxyisobutyric aciduria (McKusick 236975) and methylmalonic semialdehyde
dehydrogenase deficiency (McKusick 603178-MSDD). Until now only a few approaches
have been made in enantioselective analysis of HIBA and AIBA and for that reason
very little information is available on enantiomeric ratios of these metabolites
in man. This paper reports on the simultaneous stereodifferentiation of HIBA and
AIBA in human urine as corresponding N(O)-methoxycarbonyl methyl esters by
derivatization with methyl chloroformate (MCF) using enantioselective
multidimensional gas chromatography-mass spectrometry (enantio-MDGC/MS) with
heptakis-(2, 3-di-O-methyl-6-O-tert.-butyl-dimethylsilyl)-beta-cyclodextrin as
the chiral stationary phase. During this investigation urine samples from
different patients and healthy controls were analyzed in order to reveal
characteristic enantiomeric patterns of these metabolites. A trend of dominating
R-HIBA excretion in the control urine samples investigated was observed. An
excretion of more than 80% S-HIBA was found in the urines of two patients with
ketonemic vomiting. There are some clues indicating a possible renal reabsorbtion
of S-HIBA similar to those of S-AIBA. Furthermore, there was a significant
finding with regard to the enantiomeric distribution of AIBA in a patient with
MSDD - a markedly increased excretion of the S-enantiomer in contrast to the
other samples. Using the enantiomeric ratios of AIBA, a previously investigated
case of benign methylmalonic aciduria (bMMA) could be excluded from the diagnosis
of MSDD.
PMID- 10686280
TI - Determination of serum procarboxypeptidase A concentrations in healthy human
adults.
AB - Clostripain (EC 3.4.22.8) has been shown to be superior to trypsin as a means of
activating serum procarboxypeptidase A. With this activation and a previously
described assay for carboxypeptidase A it has been possible to determine the
concentration of procarboxypeptidase A in human serum. In order to establish a
baseline in the healthy adult a survey of the procarboxypeptidase A content of
the serum of 66 blood donors was carried out. An average value of 9.7 microg/l
was found for the proenzyme. This is in sharp contrast to a mean of 0.34 microg/l
for the free enzyme present in serum that was not treated with clostripain [1].
PMID- 10686281
TI - The effect of reaction temperature for nephelometric assays for rheumatoid
factor.
AB - Even using the same assay parameter, reagent and calibrator (N-latex RF kit II),
the results of the assay for serum rheumatoid factors (RFs) with the Behring
Nephelometer Analyzer (BNA) were higher than those with the Behring Nephelometer
II Analyzer (BNII) ([BNII]=0.76 [BNA]-5.7 kIU/l, r=0.997, Sy/x=60.73, n=99). The
mean bias (BNA minus BNII)+/-S.D. was 52.7+/-85.5 using the Bland and Altman plot
method, and the bias was not constant. The only difference in the assay condition
with the two methods was the reaction temperature with the BNA being performed at
room temperature (25+/-1 degrees C) and the BNII being performed at 37 degrees C.
The ratio of the results with the BNII to the BNA (BNII/BNA) ranged from 0.23 to
1.18. A significant difference was observed in the BNII/BNA ratio in patients
with high levels of C-reactive protein (CRP) over 2.0 mg/l (mean BNII/BNA ratio;
0.78) in comparison to patients with normal CRP levels under 2.0 mg/l (mean
BNII/BNA ratio; 0.65) (P<0.01). The RF concentrations with the BNA were reduced
by addition of urea, which has been used as a mild protein-denaturing agent, and
there was a significant correlation between the values calculated as (1-value
treated with urea/original value without urea)x100 and the BNII/BNA ratio
(r=0.652, P<0.01). These data suggested that the bias between the RF values
obtained by the BNA and BNII might be caused by the variation in the reactivity
of autoantibodies, which might be decreased in some inflammatory diseases.
PMID- 10686282
TI - Comparison of the percent free prostate-specific antigen levels in the serum of
healthy men and in men with recurrent prostate cancer after radical
prostatectomy.
AB - The percentage of free PSA in serum is currently used to better discriminate
between patients with prostate cancer and patients with benign prostatic
hyperplasia, in prostate cancer screening programs. We measured using non
competitive immunological techniques, the total PSA and free PSA in post-surgical
serum of prostate cancer patients who underwent radical prostatectomy and then
relapsed. We compared these data with those of a group of 40 age-matched men with
no evidence of prostatic disease. Although in general, patients with prostate
cancer had lower percentage of free PSA in serum in comparison to the controls, a
subset of these patients (approximately 20%) had percent free PSA significantly
higher than the levels considered as exclusive of prostate cancer in screening
programs. We also found that percent free PSA does not correlate significantly
with most of the standard clinical or pathological indicators of prostate cancer
aggressiveness. Only a weak negative association with Gleason Score was observed.
The percent free PSA in serum of relapsing prostate cancer patients varies within
a relatively wide range and does not correlate significantly with indicators of
cancer aggressiveness. The use of percent free PSA for excluding prostate cancer
in screening programs must be approached with caution until the mechanism of low
percent free PSA in the majority but not all prostate cancer patients is
elucidated.
PMID- 10686283
TI - Selection of an optimal combination of decision criteria for the internal quality
control in an automatic analyzer.
AB - After some years using an automatic analyser model Hitachi 705, we faced the task
of selecting a reasonable combination of statistical procedures for internal
quality control in order to use it in a computer program, by means of which, one
could apply all the decision criteria in a rapid and automatic manner. As a
result of the first 3 years of work, an algorithm was adopted that includes the
multirule procedure originally proposed by Westgard, but with three main
differences: (1) All the control rules are always applied; (2) the 4(1S) and 10x
control rules are used as criteria for warning or caution but not for run
rejection; and (3) the control limits are recalculated daily using all the
accumulated control results (just the accepted values). The 2(2S), 4(1S) and 10x
rules are applied first across materials (considering consecutive observations in
different control materials), and then within materials (for consecutive
observations on the same control material). The program not only has permitted us
to improve our capacity for error detection, but it has also permitted the
reduction of run rejections making an important decrease in costs possible and a
significant improvement in quality.
PMID- 10686284
TI - Mild renal dysfunction is sufficient to induce erythropoietin deficiency in
patients with unexplained anaemia.
AB - Current guidelines suggest that anaemia due to erythropoietin deficiency almost
exclusively occurs with creatinine concentrations of at least 177 micromol/l or
above. The aim of this prospective case control pilot study was to evaluate
whether borderline renal function or mild renal dysfunction with creatinine
concentrations well below 177 micromol/l is sufficient to induce inadequate
erythropoietin secretion. Patients referred for work-up of otherwise unexplained
anaemia with mildly abnormal creatinine concentrations (104-129 micromol/l; study
group: eight patients) and patients referred for work-up or therapy of other
diseases who also presented with anaemia but normal creatinine levels (<100
micromol/l; control group: nine patients matched for gender, age and degree of
anaemia) were included. All but two patients in the control group had bone marrow
biopsies to exclude other pathologies. Mild renal dysfunction (as evidenced by
creatinine concentrations between 100 and 140 micromol/l, median concentration
112 micromol/l) was found to be sufficient to induce inadequate erythropoietin
secretion. The physiologic hemoglobin-dependent erythropoietin regulation
demonstrated in the control group was abolished in the study group. Patients with
mild renal dysfunction and unexplained anaemia should be investigated for
erythropoietin concentration. If the erythropoietin concentration is found to be
inadequate for the degree of anaemia, substitution therapy should be considered.
PMID- 10686285
TI - Analysis of leukotrienes in cerebrospinal fluid of a reference population and
patients with inborn errors of metabolism: further evidence for a pathognomonic
profile in LTC(4)-synthesis deficiency.
AB - Cysteinyl leukotrienes (LTC(4), LTD(4), LTE(4)) are potent lipid mediators
derived from arachidonate in the 5-lipoxygenase pathway. Recently, the first
inborn error of leukotriene synthesis, LTC(4)-synthesis deficiency, has been
identified in association with a fatal developmental syndrome. The absence of
leukotrienes in cerebrospinal fluid was one of the most striking biochemical
findings in this disorder. We analysed leukotrienes in cerebrospinal fluid of
patients with a broad spectrum of other well-defined inborn errors of metabolism,
including glutathione synthetase deficiency (n=2), Zellweger syndrome (n=3),
mitochondrial disorders (n=8), fatty acid oxidation defects (n=7), organic
acidurias (n=7), neurotransmitter defects (n=5) and patients with non-specific
neurological symptoms, as a reference population (n=120). The concentrations of
leukotrienes were not related to age. Representative percentiles were calculated
as reference intervals of each leukotriene. In all patients with an inborn error
of metabolism concentration of cysteinyl leukotrienes and LTB(4) did not differ
from the reference group. Our results indicate that absence of cysteinyl
leukotrienes (<5 pg/ml) in association with normal or increased LTB(4) (50.0-67.3
pg/ml) is pathognomonic for LTC(4)-synthesis deficiency. The unique profile of
leukotrienes in cerebrospinal fluid in this new disorder is primarily related to
the defect and represents a new diagnostic approach.
PMID- 10686286
TI - Reference values for selected trace elements in serum of term newborns from the
urban area of Rome.
AB - Reference values for Al, Cd, Co, Cu, Li, Mn, Mo, Ni, Rb, Se and Zn, and
indicative intervals for Sb are proposed in serum from cord blood of 143 term
newborns of the urban area of Rome. On the basis of the eligibility criteria
adopted, only babies with gestational age > 37 weeks and body weight at the
delivery > 2500 g, i.e., "normal" term infants, were included in this study. With
the exception of Cd, Li, Ni and Sb, experimental data for each of the other
analytes were found to approach a normal distribution. The estimated references
values (in ng/ml) were the following: Al, 1. 12-6.79; Cd, 0.10-0.52; Co, 0.20
0.43; Cu, 140-691; Li, 0.31-2.23; Mn, 0.79-3.26; Mo, 0.36-1.56; Ni, 0.20-3.15;
Rb, 196-1302; Sb, 0. 10-1.48 (indicative range); Se, 20.2-69.7; and Zn, 318-1405.
For several elements, the information available in the relevant literature does
not allow adequate comparisons to be performed. This was actually possible only
for Cu, Se and Zn. The correlations between the weights at birth (BW),
gestational ages (GA) and elemental concentrations were elucidated. As expected,
significant positive correlations were found for Cu and Se with GA and BW,
respectively. Strong mutual associations were observed for several other
elements, but their interpretation is still debatable.
PMID- 10686287
TI - Correcting serum fructosamine concentration for total protein or albumin
concentration is not appropriate during Asian pregnancy.
PMID- 10686288
TI - Serum dipeptidylpeptidase activity and tissue polypeptide specific antigen in
patients with advanced cirrhosis: preliminary results.
PMID- 10686290
TI - Alpha 1-adrenoceptors: function and phosphorylation.
AB - This review focuses on alpha(1)-adrenoceptor phosphorylation and function. Most
of what is currently known is based on studies on the hamster alpha(1B)
adrenoceptor. It is known that agonist stimulation leads to homologous
desensitization of these receptors and current evidence indicates that such
decrease in receptor activity is associated with receptor phosphorylation. Such
receptor phosphorylation seems to involve G protein-receptor kinases and the
receptor phosphorylation sites have been located in the carboxyl tail (Ser(404),
Ser(408), and Ser(410)). There is also evidence showing that in addition to
desensitization, receptor phosphorylation is associated with internalization and
roles of beta-arrestins have been observed. Direct activation of protein kinase C
leads to receptor desensitization/internalization associated with
phosphorylation; the protein-kinase-C-catalyzed receptor phosphorylation sites
have been also located in the carboxyl tail (Ser(394) and Ser(400)). Activation
of G(q)-coupled receptors, such as the endothelin ET(A) receptor induces
alpha(1B)-adrenoceptor phosphorylation and desensitization. Such effect involves
protein kinase C and a yet unidentified tyrosine kinase. Activation of G(i)
coupled receptors, such as the lysophosphatidic acid receptor, also induces
alpha(1B)-adrenoceptor phosphorylation and desensitization. These effects involve
protein kinase C and phosphatidyl inositol 3-kinase. Interestingly, activation of
epidermal growth factor receptors also induces alpha(1B)-adrenoceptor
phosphorylation and desensitization involving protein kinase C and phosphatidyl
inositol 3-kinase. A pivotal role of these kinases in heterologous
desensitization is evidenced.
PMID- 10686291
TI - Proteolysis and phosphorylation-mediated regulation of thrombin receptor activity
in in situ endothelial cells.
AB - The regulatory mechanism of thrombin receptor responsiveness in in situ
endothelial cells was investigated by evaluating elevations of cytosolic Ca(2+)
concentration ([Ca(2+)](i)) in fura-2-loaded porcine aortic valvular strips. Once
stimulated with thrombin, endothelial cells did not respond to the second
thrombin stimulation within 90 min. However, applying thrombin receptor
activating peptide (TRAP7) at 15 min after the thrombin stimulation caused
[Ca(2+)](i) elevation, which was smaller than that seen without preceding
stimulation. After 90 min, response to TRAP7 recovered to the control level. When
stimulated with TRAP7, the subsequent responses to thrombin and TRAP7 were
attenuated at 15 min, and fully recovered after 90 min. Staurosporine partially
prevented the TRAP7-induced desensitization. The recovery of responsiveness was
inhibited completely by calyculin-A and partially by okadaic acid. Proteolysis
and phosphorylation thus play an important role in thrombin receptor
desensitization in in situ endothelial cells. Both cleaved and uncleaved
receptors were desensitized through phosphorylation in part by staurosporine
sensitive kinase, and restored the responsiveness through dephosphorylation by
type 1 phosphatase. The mechanism of regulation of thrombin receptor activity in
in situ endothelial cells differed from those reported in cultured endothelial
cells. We suggest that the cell-specific regulatory mechanism may be altered by
culture conditions.
PMID- 10686292
TI - Prostanoids regulate proliferation of vascular smooth muscle cells induced by
arginine vasopressin.
AB - The aim of the present study was to investigate the effect of arginine
[Arg(8)]vasopressin (vasopressin) on proliferation of vascular smooth muscle
cells and the mechanisms underlying the action of vasopressin. To clarify these
issues, we used two different types of vascular smooth muscle cells, cultured
adult rat aortic smooth muscle cells and A10 cells, a cell line derived from
fetal rat aorta. Vasopressin (10(-8) to 10(-6) M) significantly stimulated the
proliferation of rat aortic smooth muscle cells in a dose-dependent manner. In
contrast, vasopressin significantly inhibited the proliferation of A10 cells.
This inhibition was abolished when A10 cells were treated with indomethacin.
Vasopressin stimulated the production of prostanoids several-fold in A10 cells
but not in rat aortic smooth muscle cells. These effects were completely blocked
by the vasopressin V(1) receptor antagonist, 1-?1-[4-(3-acetylamino
propoxy)benzoyl]4-piperidyl?-3, 4-dihydro-2(1H)-quinolinone (OPC21268), but not
by the vasopressin V(2) receptor antagonist, (+/-)-5-dimethylamino-1-[4-(2
methylbenzoylamino)benzol]-2, 3,4,5-tetrahydro-1H-benzazepine hydrochloride
(OPC31260). These results indicate that vasopressin has diverse effect on
proliferation of vascular smooth muscle cells through the vasopressin V(1)
receptor, depending on the production of growth regulatory prostanoids.
PMID- 10686293
TI - Tyrosine kinase inhibitors and Ca2+ signaling: direct interactions with fura-2.
AB - Selective inhibitors were used to study the role of tyrosine kinases in alpha(1A)
adrenoceptor-mediated responses in transfected PC12 cells. Ca(2+) responses to
noradrenaline were measured using fura-2, and the effects of genistein,
tyrphostin A25, and herbimycin A were examined. Neither genistein nor herbimycin
A pretreatment altered noradrenaline-induced Ca(2+) responses, although
tyrphostin A25 pretreatment caused some reduction. However, acute addition of
genistein quickly reversed the apparent noradrenaline response, apparently,
through a direct interaction with cytoplasmic fura-2. Both genistein and
tyrphostin A25, at concentrations similar to those used to inhibit tyrosine
kinases, markedly reduced fluorescence of fura-2 excited by both 340 and 380 nm,
and genistein also reduced the 340/380 ratio. Tyrosine kinase inhibitors did not
alter noradrenaline stimulated inositol phosphate formation in alpha(1A)-PC12
cells. These results suggest that tyrosine kinases are not involved in second
messenger responses to alpha(1A)-adrenoceptors, but that tyrosine kinase
inhibitors can interact directly with fura-2.
PMID- 10686294
TI - Species selectivity of a small molecule antagonist for the CCR1 chemokine
receptor.
AB - The species specificity of a small molecule antagonist for the human CCR1
chemokine receptor, 2-2-diphenyl-5-(4-chlorophenyl)piperidin-1-yl)valeronitrile
(CCR1 antagonist 1), has been examined using cloned CCR1 receptors from various
species. The compound was able to bind to rabbit, marmoset, and human CCR1, and
was able to block the functional activation of these receptors. However, it
failed to significantly displace radiolabeled macrophage inflammatory protein
1alpha (MIP-1alpha) binding to mouse CCR1 at concentrations up to 10 microM.
These data suggested that the antagonist binding site is well-conserved in
rabbit, marmoset and human CCR1, but not in mouse CCR1. The functional
selectivity and mechanism of action for CCR1 antagonist 1 were further
characterized. CCR1 antagonist 1 blocked the increase in intracellular Ca(2+)
stimulated by CCR1 agonists, but had no effect on N-formyl-Met-Leu-Phe (FMLP),
monocyte chemotactic protein-1 (MCP-1) and stromal-derived factor 1alpha
(SDF1alpha)-induced Ca(2+) mobilization, demonstrating functional selectivity for
CCR1. Since CCR1 antagonist 1 is a functional antagonist of marmoset and rabbit
CCR1 receptors, it should be possible to test its efficacy in animal models of
disease.
PMID- 10686295
TI - Cromakalim-induced membrane current in guinea-pig tracheal smooth muscle cells.
AB - The characteristics of the cromakalim-induced membrane current were examined in
single tracheal myocytes of the guinea-pig under voltage-clamp conditions. When
K(+) concentrations in the pipette and bathing solutions were approximately 140
mM, cromakalim activated a membrane current (I(crom)) which was inward at -60 mV
and reversed at -2 mV. I(crom) was blocked by 10 microM glibenclamide and
potentiated when the ATP concentration in the pipette solution was decreased. The
K(d) and Hill coefficient of glibenclamide for I(crom) block were 200 nM and
1.05, respectively. Application of the tyrosine kinase inhibitors, genistein and
alpha-cyano-3-ethoxy-4-hydroxy-5-phenylthiomethylcinnamamid (ST638), reduced
I(crom) in a concentration-dependent manner. Daidzein, which does not inhibit
tyrosine kinase, was about 10 times less effective than genistein. Herbimycin A
had no effect on I(crom). Internal application of these inhibitors from the
pipette did not affect I(crom). In conclusion, cromakalim is a potent activator
of the ATP-sensitive K(+) channel (K(ATP) channel) in guinea-pig tracheal
myocytes. The inhibition of I(crom) by genistein and ST638 may be due to the
direct block of the channel from outside.
PMID- 10686296
TI - Dopamine transporter antagonists block phorbol ester-induced dopamine release and
dopamine transporter phosphorylation in striatal synaptosomes.
AB - We have reported that inhibition of protein kinase C blocks the Ca(2+)
independent reverse transport of dopamine mediated by amphetamine. In this study
we investigated whether activation of protein kinase C by 12-O-tetradecanoyl
phorbol-13-acetate (TPA) would mediate dopamine release through the plasmalemmal
dopamine transporter. TPA, at 250 nM, increased the release of dopamine from rat
striatal slices and synaptosomes while the inactive phorbol ester, 4alpha
phorbol, was ineffective. The TPA-mediated dopamine release was independent of
extracellular calcium and was blocked by a selective protein kinase C inhibitor,
Ro31-8220. The dopamine transporter antagonists, cocaine and GBR 12935 blocked
the TPA-mediated dopamine release. In addition, cocaine blocked TPA-mediated
phosphorylation of the plasmalemmal dopamine transporter. These results suggest
that activation of protein kinase C results in reverse transport of dopamine
through the plasmalemmal dopamine transporter and the phosphorylated substrate
could be the dopamine transporter.
PMID- 10686297
TI - Cyclooxygenase-independent inhibition of smooth muscle cell mitogenesis by
ibuprofen.
AB - The aryl-propionic acid derivative, ketoprofen, has been shown to inhibit
fibroblast growth by a cylooxygenase-dependent mechanism [Sanchez, T., Moreno,
J.J., 1999. S(+) enantiomer inhibits prostaglandin production and cell growth in
3T6 fibroblast cultures. Eur. J. Pharmacol. 370, 63-67]. The present study
demonstrates that ibuprofen, another aryl-propionic acid derivative, inhibited
platelet-derived growth factor-BB (20 ng/ml)-induced mitogenesis of cultured
bovine coronary artery smooth muscle cells in a stereo-independent manner. In
addition, pretreatment of the cells with indomethacin (3 microM) did not affect
the inhibitory effects of ibuprofen enantiomers on smooth muscle cell
mitogenesis. Thus, aryl-propionic acid-type cyclooxygenase inhibitors can inhibit
cell proliferation by both, cyclooxygenase-dependent and -independent ways.
PMID- 10686298
TI - Differential role of nitric oxide pathway and heat shock protein in
preconditioning and lipopolysaccharide-induced brain ischemic tolerance.
AB - The purposes of this study were to investigate the role of nitric oxide (NO),
nitric oxide synthase (NOS), and 70 kDa heat shock protein in brain ischemic
tolerance induced by ischemic preconditioning and lipopolysaccharide. Focal
cerebral ischemia was induced in rats by intraluminal middle cerebral artery
occlusion. Infarct volume was significantly reduced (1) in rats subjected to 3
min ischemia 72 h prior to 60 min ischemia; (2) in rats administered
lipopolysaccharide (0.5 mg/kg; i.p.) 72 h prior to 60 min ischemia compared with
controls. The beneficial effect of ischemic preconditioning was unchanged despite
prior administration of nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor.
Conversely, the protective effect of lipopolysaccharide was nullified by L-NAME.
Using immunohistochemical techniques, we observed that (1) ischemic
preconditioning but not lipopolysaccharide induces the expression of 70 kDa heat
shock protein in cerebral cortex and (2) lipopolysaccharide induces early
increased expression of endothelial NOS in cerebral blood vessels. The results
suggest that (1) endothelium-derived NO plays a role of a trigger in the brain
tolerance induced by lipopolysaccharide, and (2) 70 kDa heat shock protein is
involved in the protection afforded by ischemic preconditioning but not by
lipopolysaccharide.
PMID- 10686299
TI - Neuroprotection by LY341122, a novel inhibitor of lipid peroxidation, against
focal ischemic brain damage in rats.
AB - LY341122 (2-(3, 5-di-t-butyl-4-hydroxyphenyl)-4-(2-(4-methylethylaminomethyl-ph
enylox y)ethyl)oxazole) is a potent inhibitor of lipid peroxidation which has
been shown to protect against global ischemia and traumatic brain injury in rats.
The purpose of this study was to examine the effect of LY341122 on ischemic
injury in a highly reproducible model of focal cerebral ischemia in rats. Male
Sprague-Dawley rats were anesthetized with halothane and subjected to 120 min of
temporary middle cerebral artery occlusion by retrograde insertion of an
intraluminal nylon suture coated with poly-L-lysine. The drug (LY341122, n=19) or
vehicle (phosphate-buffered saline (PBS), n=10) was administered i.v. (as a 5 or
10 mg/kg bolus followed by a 5 or 10 mg/kg/h infusion for 20 h, respectively,
starting 1 or 2 h after the onset of middle cerebral artery occlusion).
Neurological status was evaluated during middle cerebral artery occlusion (60
min) and daily for 3 days thereafter. Three days after ischemia, brains were
perfusion-fixed and infarct volumes and brain edema were determined. LY341122
significantly improved the neurological score compared to vehicle at 24, 48 and
72 h after middle cerebral artery occlusion. Treatment with LY341122
significantly reduced total infarct volume in all treated groups compared to
vehicle rats. Cortical infarct volume was significantly reduced by LY341122
treatment in the 10 mg/kg (1 h) and LY341122 10 mg/kg (2 h) groups compared to
vehicle rats (14.7+/-9.5 vs. 106.8+/-20.9 mm(3), and 36.9+/-20.1 vs. 106. 8+/
20.9 mm(3), respectively (mean+/-S.E.M.)). Striatal infarct volume was also
significantly reduced by treatment with LY341122 in the 10 mg/kg (1 h) group
compared to vehicle (23.7+/-3.4 vs. 68. 2+/-6.7 mm(3)). These results demonstrate
the neuroprotective efficacy of LY341122 in focal cerebral ischemia.
PMID- 10686300
TI - Endogenous corticotropin-releasing hormone inhibits conditioned-fear-induced
vagal activation in the rat.
AB - The role of the endogenous corticotropin-releasing hormone (CRH) system in the
regulation of heart rate, PQ interval (a measure of vagal activity), gross
activity and release of adrenocorticotropic hormone (ACTH), noradrenaline and
adrenaline into the blood during conditioned fear was studied in freely moving
rats. Intracerebroventricular (i.c.v.) infusion of alpha-helical CRH-(9-41) (10
microgram/3 microliter), a non-selective CRH receptor antagonist, under resting
conditions had no significant effect on gross activity, heart rate and PQ
interval, indicating that alpha-helical CRH at this dose was devoid of agonist
effects. Conditioned fear was induced by 10 min forced exposure to a cage in
which the rat had experienced footshocks (5x0.5 mAx3 s) 1 day before. Conditioned
fear rats showed freezing behaviour, associated with an increase in heart rate,
PQ interval, noradrenaline and adrenaline, indicating that the conditioned-fear
induced cardiac effects were the result of coactivation of the sympathetic and
parasympathetic nervous system. The i.c.v. pre-treatment of rats with alpha
helical CRH significantly reduced the conditioned-fear-induced tachycardiac and
ACTH response, and enhanced the increase in PQ interval, without affecting the
noradrenaline and adrenaline response. These results suggest that endogenous CRH
reduces the vagal response to conditioned-fear stress in rats. To test this, rats
were pre-treated with atropine methyl nitrate (0.3 mg/kg, subcutaneously; s.c.),
a peripherally acting cholinergic receptor antagonist. This resulted in a
complete blockade of the alpha-helical CRH-induced decrease in heart rate
response and increase in PQ interval. From these findings, it is concluded that
endogenous CRH in the brain inhibits vagal outflow induced by emotional stress.
PMID- 10686301
TI - Tachykinin-mediated effect of nociceptin in the rat urinary bladder in vivo.
AB - The application of nociceptin (5-50 nmol/rat) onto the serosa in the urinary
bladder of urethane-anaesthetized rats, with the intravesical volume kept below
threshold for activation of the micturition reflex, induced a low amplitude tonic
contraction (local, i.e., resistant to ganglionectomy) with high amplitude phasic
contractions (reflex, i.e., abolished by ganglionectomy) superimposed. The
pharmacology of the local contraction was studied in animals with acute bilateral
ablation in the pelvic ganglia: the combined administration of tachykinin NK(1)
(S)1-?2-[3-(3, 4-dichlorophenyl)-1-(3-isopropoxyphenyl-acetyl)-piperidin-3-yl]eth
yl?-4-phenyl-1-azoniabicyclo[2.2.2.]octane chloride (SR 140333) and NK(2)
c?[(beta-D-GlcNAc)Asn-Asp-Trp-Phe-Dpr-Leu]c(2beta-5beta++ +)? (MEN 11420)
receptor antagonists (given at doses of 1+0.1 micromol/kg, intravenous (i.v.),
respectively) abolished the local bladder contraction induced by topical
nociceptin (50 nmol/rat). These results indicate that the topical application of
nociceptin onto the bladder evokes a tachykinin-mediated contraction.
PMID- 10686302
TI - Y-27632 potentiates relaxant effects of beta 2-adrenoceptor agonists in bovine
tracheal smooth muscle.
AB - We examined how (+)-(R)-trans-4-(1-aminoethyl)-N-(4
pyridyl)cyclohexanecarboxamide (Y-27632), an inhibitor of Rho-associated coiled
coil-forming protein kinase (ROCK I) and Rho kinase (ROCK II), affects the
relaxant responses to beta(2)-adrenoceptor agonists in bovine tracheal smooth
muscle preparations precontracted with methacholine. Y-27632 (0.3-30 microM)
caused a concentration-dependent attenuation of precontraction with methacholine
(0.3-3 microM). Pretreatment with Y-27632 (1 microM) significantly (P<0.05)
augmented salbutamol (0.3-100 nM) and terbutaline (0.3 nM-1 microM)-induced
relaxations. These results suggest that the ROCK inhibitor could become a new
type bronchodilator and its combination with beta(2)-adrenoceptor agonists may
become a novel strategy for the long-term treatment of asthma.
PMID- 10686303
TI - Paracelsus to parascience: the environmental cancer distraction.
AB - Entering a new millennium seems a good time to challenge some old ideas, which in
our view are implausible, have little supportive evidence, and might best be left
behind. In this essay, we summarize a decade of work, raising four issues that
involve toxicology, nutrition, public health, and government regulatory policy.
(a) Paracelsus or parascience: the dose (trace) makes the poison. Half of all
chemicals, whether natural or synthetic, are positive in high-dose rodent cancer
tests. These results are unlikely to be relevant at the low doses of human
exposure. (b) Even Rachel Carson was made of chemicals: natural vs. synthetic
chemicals. Human exposure to naturally occurring rodent carcinogens is
ubiquitous, and dwarfs the general public's exposure to synthetic rodent
carcinogens. (c) Errors of omission: micronutrient inadequacy is genotoxic. The
major causes of cancer (other than smoking) do not involve exogenous carcinogenic
chemicals: dietary imbalances, hormonal factors, infection and inflammation, and
genetic factors. Insufficiency of many micronutrients, which appears to mimic
radiation, is a preventable source of DNA damage. (d) Damage by distraction:
regulating low hypothetical risks. Putting huge amounts of money into minuscule
hypothetical risks damages public health by diverting resources and distracting
the public from major risks.
PMID- 10686304
TI - How we should deal with unavoidable exposure of man to environmental mutagens:
cooked food mutagen discovery, facts and lessons for cancer prevention.
PMID- 10686305
TI - Formation of DNA adducts and induction of mutagenic effects in rats following 4
weeks inhalation exposure to ethylene oxide as a basis for cancer risk
assessment.
AB - Ethylene oxide (EO) is mutagenic in various in vitro and in vivo test systems and
carcinogenic in rodents. EO forms different adducts upon reaction with DNA, N7-(2
hydroxyethyl)guanine (N7-HEG) being the main adduct. The major objectives of this
study were: (a) to determine the formation and persistence of N7-HEG adducts in
liver DNA of adult male rats exposed to 0, 50, 100 and 200 ppm by inhalation (4
weeks, 5 days/week, 6 h/day) and (b) to assess dose-response relationships for
Hprt gene mutations and various types of chromosomal changes in splenic
lymphocytes.N7-HEG adducts were measured 5, 21, 35 and 49 days after cessation of
exposure. By extrapolation, the mean concentrations of N7-HEG immediately after
cessation of exposure ('day 0') to 50, 100 and 200 ppm were calculated as 310,
558 and 1202 adducts/10(8) nucleotides, respectively, while the mean
concentration in control rats was 2.6 adducts/10(8) nucleotides. At 49 days, N7
HEG values had returned close to background levels. The mean levels of N-(2
hydroxyethylvaline) adducts in haemoglobin were also determined and amounted
61.7, 114 and 247 nmol/g globin, respectively. Statistically significant linear
relationships were found between mean N7-HEG levels ('day 0') and Hprt mutant
frequencies at expression times 21/22 and 49/50 days and between mean N7-HEG
('day 0') and sister-chromatid exchanges (SCEs) or high frequency cells (HFC)
measured 5 days post-exposure. At day 21 post-exposure, SCEs and HFCs in-part
persisted and were significantly correlated with persistent N7-HEG adducts. No
statistically significant dose effect relationships were observed for induction
of micronuclei, nor for chromosome breaks or translocations. In conclusion, this
study indicates that following sub-chronic exposure, EO is only weakly mutagenic
in adult rats. Using the data of this study to predict cancer risk in man
resulting from low level EO exposures in conjunction with other published data,
i.e., those on (a) genotoxic effects of EO in humans and rats, (b) DNA binding of
other carcinogens, (c) natural background DNA binding and (d) genotoxic potency
of low energy transfer (LET) radiation, it is not expected that long term
occupational exposure to airborne concentrations of EO at or below 1 ppm EO
produces an unacceptable increased risk in man.
PMID- 10686306
TI - DNA repair: models for damage and mismatch recognition.
AB - Maintaining the integrity of the genome is critical for the survival of any
organism. To achieve this, many families of enzymatic repair systems which
recognize and repair DNA damage have evolved. Perhaps most intriguing about the
workings of these repair systems is the actual damage recognition process. What
are the chemical characteristics which are common to sites of nucleic acid damage
that DNA repair proteins may exploit in targeting sites? Importantly,
thermodynamic and kinetic principles, as much as structural factors, make damage
sites distinct from the native DNA bases, and indeed, in many cases, these are
the features which are believed to be exploited by repair enzymes. Current
proposals for damage recognition may not fulfill all of the demands required of
enzymatic repair systems given the sheer size of many genomes, and the efficiency
with which the genome is screened for damage. Here we discuss current models for
how DNA damage recognition may occur and the chemical characteristics, shared by
damaged DNA sites, of which repair proteins may take advantage. These include
recognition based upon the thermodynamic and kinetic instabilities associated
with aberrant sites. Additionally, we describe how small changes in base pair
structure can alter also the unique electronic properties of the DNA base pair pi
stack. Further, we describe photophysical, electrochemical, and biochemical
experiments in which mismatches and other local perturbations in structure are
detected using DNA-mediated charge transport. Finally, we speculate as to how
this DNA electron transfer chemistry might be exploited by repair enzymes in
order to scan the genome for sites of damage.
PMID- 10686307
TI - Population risk and physiological rate parameters for colon cancer. The union of
an explicit model for carcinogenesis with the public health records of the United
States.
AB - The relationship between the molecular mechanisms of mutagenesis and the actual
processes by which most people get cancer is still poorly understood. One missing
link is a physiologically based but quantitative model uniting the processes of
mutation, cell growth and turnover. Any useful model must also account for human
heterogeneity for inherited traits and environmental experiences. Such a coherent
algebraic model for the age-specific incidence of cancer has been developing over
the past 50 years. This development has been spurred primarily by the efforts of
Nordling [N.O. Nordling, A new theory on the cancer-inducing mechanism, Br. J.
Cancer 7 (1953) 68-72], Armitage and Doll [P. Armitage, R. Doll, The age
distribution of cancer and a multi-stage theory of carcinogenesis, Br. J. Cancer
8 (1) (1954) 1-12; P. Armitage, R. Doll, A two-stage theory of carcinogenesis in
relation to the age distribution of human cancer, Br. J. Cancer 9 (2) (1957) 161
169], and Moolgavkar and Knudson [S.H. Moolgavkar, A.G. Knudson Jr., Mutation and
cancer: a model for human carcinogenesis. JNCI 66 (6) (1981) 1037-1052], whose
work defined two rate-limiting stages identified with initiation and promotion
stages in experimental carcinogenesis. Unfinished in these efforts was an
accounting of population heterogeneity and a complete description of growth and
genetic change during the growth of adenomas. In an attempt to complete a unified
model, we present herein the first means to explicitly compute the essential
parameters of the two-stage initiation-promotion model using colon cancer as an
example. With public records from the 1930s to the present day, we first
calculate the fraction at primary risk for each birth year cohort and note
historical changes. We then calculate the product of rates for n initiation
mutations, the product of rates for m promotion-mutations and the average growth
rate of the intermediate adenomatous colonies from which colon carcinomas arise.
We find that the population fraction at primary risk for colon cancer risk was
historically invariant at about 42% for the birth year cohorts from 1860 through
1930. This was true for each of the four cohorts we examined (European- and
African-Americans of each gender). Additionally, the data indicate an historical
increase in the initiation-mutation rates for the male cohorts and the promotion
mutation rates for the female cohorts. Interestingly, the calculated rates for
initiation-mutations are in accord with mutation rates derived from observations
of mutations in peripheral blood cells drawn from persons of different ages.
Adenoma growth rates differed significantly between genders but were essentially
historically invariant. In its present form, the model has also allowed us to
calculate the rate of loss of heterozygosity (LOH) or loss of genomic imprinting
(LOI) in adenomas to result in the high LOH/LOI fractions in tumors. But it has
not allowed us to specify the number of events m required during promotion.
PMID- 10686308
TI - Somatic mutations and aging: a re-evaluation.
AB - Aging has been explained in terms of an accumulation of mutations in the genome
of somatic cells, leading to tissue atrophy and neoplasms, as well as increased
loss of function. Recent advances in transgenic mouse modeling and genomics
technology have created, for the first time, the opportunity to begin testing
this theory. In this paper the existing evidence for a possible role of somatic
mutation accumulation in aging will be re-evaluated on the basis of the
evolutionary logic of aging and recent insights in genome structure and function.
New strategies for investigating the relationship between genome instability,
mutation accumulation and aging will be discussed.
PMID- 10686309
TI - Nephrotoxicity of calcineurin inhibitors: new therapeutic approaches.
PMID- 10686310
TI - Mycophenolate mofetil monotherapy: an example of a safe
nephrotoxicity/atherogenicity-free immunosuppressive maintenance regimen in a
selected group of kidney-transplanted patients.
PMID- 10686311
TI - Nephrotoxicity-free, mycophenolate mofetil-based induction/maintenance
immunosuppression in elderly recipients of renal allografts from elderly
cadaveric donors.
PMID- 10686312
TI - Protocol core biopsy (CADI): a surrogate marker for chronic rejection.
Mycophenolate Mofetil ICM 1866 and IICR 023 Study Groups.
PMID- 10686313
TI - Is tolerance a clinical reality?
PMID- 10686314
TI - Steroid withdrawal in renal transplant recipients.
PMID- 10686315
TI - The influence of environmental contaminants on lysosomal activity in the
digestive cells of mussels (Mytilus galloprovincialis) from the Venice Lagoon.
AB - Lysosomes are subcellular organelles bounded by a semipermeable lipoprotein
membrane that contain a battery of hydrolytic enzymes that are collectively
capable of degrading all classes of indogenous and exogenous macromolecules.
Lysosomes accumulate a diverse range of chemical contaminants which can lead to
membrane damage resulting in leakage of their contents into the cytosol and
damage to cells. Total lysosomal activity for two acid hydrolases, N-acetyl-beta
D-hexosaminidase and beta-glucuronidase, with different substrate specificities
was determined histochemically in digestive gland sections of mussels, Mytilus
galloprovincialis from a series of sites in the Venice Lagoon and the Adriatic
Sea and correlated, using multi-stepwise regression analysis, with tissue
contaminant burdens in order to explore causality. The results indicated that
whilst activity of N-acetyl-beta-D-hexosaminidase correlated with body burdens of
mercury, beta-glucuronidase, by contrast, correlated with DDT, Arochlor 1254 and
eight PCB congeners in combination with iron or zinc.
PMID- 10686316
TI - Estrogenic response of bisphenol A in rainbow trout (Oncorhynchus mykiss).
AB - Bisphenol A (BPA) previously shown to possess xenoestrogenic activities was
administered to rainbow trout (Oncorhynchus mykiss) through a continuos flow
system. The estrogenic response expressed as the induction of vitellogenin (VTG)
synthesis was measured during 12 days of exposure, using a direct sandwich ELISA.
Quantification of internal liver and muscle concentrations of non-metabolised BPA
was performed by LC-MS at the end of the exposure period. A significant induction
of the VTG synthesis was obtained at 500 ug BPA/l exposure, although an increase
in the ratio of responding animals was observed already between 40 and 70 ug
BPA/l. An increase in VTG levels was observed for the 500 ug BPA/l group over the
study period, whereas constant or decreasing levels could be detected in the low
exposure groups between days 6 and 12. Average internal liver concentrations of
BPA increased from 0.22 to 4.36 ug/g for the 10-500 ug BPA/l groups. However, BPA
could not be detected in muscle tissue below an exposure level of 70 ug BPA/l. A
dose response relationship was established between the internal liver
concentrations of BPA and the corresponding VTG responses, with a P<0.001 and a
correlation coefficient of 0.66.
PMID- 10686317
TI - Relationship between toxicant transfer kinetic processes and fish oxygen
consumption.
AB - Three organic compounds of different hydrophobicity, 1,2,4,5-tetrachlorobenzene
(TeCB), 3,4,5,6-tetrachloroguaiacol (TeCG) and 4,6-dichlorobenzenediol (DBD),
were chosen as the test chemicals to carry out a series of investigations to look
at the relationship between toxicant transfer and fish metabolic rate. A
significant correlation was found between the toxicant uptake rate constant
(k(1)) and fish oxygen consumption, regardless of fish size and species. This
correlation was improved when fish toxicant body load was expressed on a percent
body lipid basis. Similarly, there also existed a significant relationship
between the toxicant depuration rate constant (k(2)) and fish oxygen uptake for a
range of chemicals with different octanol/water partition coefficients (K(ow)).
PMID- 10686318
TI - A physiological model to predict xenobiotic concentration in fish.
AB - A physiological model was developed to estimate fish body toxicant load based on
information regarding the chemical exposure regime, fish body weight, lipid
content and oxygen uptake. The general model was tested in which an oxygen
database (OXYREF) was used to predict fish toxicant body burden. Based on the
quantitative analysis, it was shown that the model was reliable and accurate in
estimating fish body burden of a number of non-metabolized aquatic toxicants.
This modified model possesses some functional reality which enables more
realistic predictions, making it useful in the practice of aquatic environmental
risk assessment.
PMID- 10686319
TI - Down-regulation of fibronectin in rainbow trout gonadal cells exposed to retinoic
acid.
AB - Exposure of fish to some environmental contaminants results in alterations to the
levels of retinoid (Vitamin A) stores, which could result in an increase in
cellular concentrations of biologically active metabolites such as retinoic acid
(RA). However, a link has not been established between changes in retinoid
metabolism and impacts on the health of biota. In vitro studies with mammalian
cells have demonstrated a relationship between exposure to RA and expression of
the extracellular matrix protein, fibronectin (FN); a protein critical for cell
migration, adhesion, and transformation. In this study, in vitro exposures of
rainbow trout gonadal cells (RTG-2) to RA reduced levels of FN in culture medium;
as measured using SDS-PAGE and immunoblot analysis with antisera prepared against
RTG-2 cellular fibronectin. This apparent down-regulation of FN secretion
occurred in a dose-dependent manner over a range of RA concentrations (10(-10)
10(-6) M). FN down-regulation was not accompanied by changes in the morphology of
RTG-2. Future studies should be directed at determining the relationships between
retinoid metabolism and FN expression and the potential effects of contaminant
induced changes to vitamin A metabolism on the health of fish.
PMID- 10686320
TI - The sensitivity of grass shrimp, Palaemonetes pugio, embryos to organophosphate
pesticide induced acetylcholinesterase inhibition.
AB - Grass shrimp, Palaemonetes pugio, are common inhabitants of salt marshes along
the Atlantic and Gulf coasts of North America. Grass shrimp embryos are brooded
externally on the abdomen of adult females for about 2 weeks prior to hatching.
In South Carolina, the spring spawning period for grass shrimp coincides with the
period of peak pesticide application on crops grown along the South Carolina
coast. Thus, grass shrimp of all developmental stages are at risk of exposure to
pesticides present in nonpoint source agricultural runoff. Organophosphate (OP)
insecticides are commonly applied agricultural chemicals which produce toxicity
by inhibiting the nervous system enzyme, acetylcholinesterase (AChE). The purpose
of this study was to examine the development of AChE activity in grass shrimp
embryos and to assess their sensitivity to OP-induced AChE inhibition. Embryos
were exposed for 24 h to either chlorpyrifos or malathion. All exposure
concentrations were nominal and ranged from 0 to 2.00 ug l(-1) for chlorpyrifos
and from 0 to 120.00 ug l(-1) for malathion. Quantifiable levels of AChE activity
first appeared at Stage V of development and increased as embryonic development
progressed. AChE inhibition by the OPs was assessed in Stage VI and Stage VII
embryos. Both stages of embryos were more sensitive to chlorpyrifos than
malathion. The 24-h Effective Concentration (EC(50)) values for chlorpyrifos were
0.49 ug l(-1) (95% C.I.=0.33-0.77 ug l(-1)) and 0.36 ug l(-1) (95% C.I.=0.33-0.38
ug l(-1)) for Stage VI and Stage VII embryos, respectively. In comparison,
malathion 24-h EC(50) values were 55.53 ug l(-1) (95% C.I.=22.08-80.73 ug l(-1))
for Stage VI embryos and 29.93 ug l(-1) (95% C.I.=25.22-44.22 ug l(-1)) for Stage
VII embryos. For both OPs, there were no significant differences in the EC(50)
values calculated for Stage VI and Stage VII embryos; however, AChE inhibition
was significantly (P=0.05) greater in Stage VII embryos at the two highest
exposure concentrations for each insecticide. A comparison of the results of
these embryo tests with those found for adult and larval toxicity tests indicated
that embryos were at least as sensitive to both the OPs as larval and adult grass
shrimp. Embryo bioassays provide a number of important advantages over
traditional laboratory toxicity tests including reduced laboratory space
requirements, large numbers of embryos from a few ovigerous females, and small
volumes of waste.
PMID- 10686321
TI - Responses of aquatic communities to 25-6 alcohol ethoxylate in model stream
ecosystems.
AB - A model stream ecosystem evaluation of the non-commercial alcohol ethoxylate 25-6
alcohol ethoxylate (AE) was performed in 1994. Algal, heterotrophic microbial,
protozoan, and invertebrate communities were assessed over an 8-week exposure
period that followed an 8-week colonization period. Streams were exposed to
nominal concentrations of 0, 12, 37, 111, 333 and 1000 ug AE/l. Confirmed
concentrations (8-week means) were 7 (at the detection limit), 13, 36, 76, 259,
and 760 ug AE/l as measured at the head of streams on a weekly basis. Microbial
communities were initially enhanced by AE exposure (first 2 weeks of exposure),
but by the conclusion of the study autotrophic and heterotrophic microbial
communities were similar across treatments. In contrast, invertebrate populations
and communities responded strongly to AE exposure with adverse effects indicated
at 259-760 ug/l by 4 weeks and at 36-760 ug/l by 8 weeks. Key affected groups
were the sensitive mayfly, stonefly, and caddisfly fauna. Species richness and
abundance of selected populations such as Stenonema (mayfly), Chimarra
(caddisfly), and Corbicula (Asiatic clam) were affected. These data indicated a
model ecosystem no-observed effect concentration of 13 ug/l for 25-6 AE. In
contrast to other published AE model ecosystem studies, 25-6 appears more toxic.
Structure-activity-relationships at the model ecosystem level still demonstrate
good relationships across a range of surfactants with calculated K(ow)s of 3-6.
Importantly, the collective information on fate and effects measured in
laboratory and field systems confirms low risk to the environment.
PMID- 10686322
TI - Effects of cadmium exposure on volume regulation in the lugworm, Arenicola
marina.
AB - Effects of hypo-osmotic stress and Cd (cadmium) exposure, applied singly or in
combination, on volume regulation were investigated in Arenicola marina, the
common European lugworm. In short-term experiments, the combined exposure to Cd
and hypo-osmotic stress mainly affected the worm's capacity for regulating the
coelomic fluid volume without significantly affecting the regulation of
intracellular fluid volume. Exposure to Cd increased the worm's sensitivity to
hypo-osmotic stress noted as increased mortality compared to the mortality in
groups exposed only to Cd or hypo-osmotic stress. In long-term Cd exposure
experiments, the capacity for coelomic fluid volume regulation was affected even
at constant external osmolarity and the tissue water concentration decreased
slightly. The results could not be explained by changes in Apparent Water
Permeability (AWP) as Cd did not significantly affect this. The glycogen content
of the chloragogenous tissue did, however, increase during long-term Cd exposure
suggesting a metabolic effect. The results demonstrate that two stressors, each
without serious effects when applied alone, may have fatal effects when applied
in combination. The kind of osmotic stress applied in these experiments is common
in many biotopes inhabited by the lugworm. The severe effects of the combination
with Cd exposure indicate that classical ecotoxicology testing could conceivably
underestimate the toxicity of chemical compounds due to not considering combined
effects of natural and anthropogenic stressors.
PMID- 10686323
TI - Xenobiotic and steroid biotransformation activities in rainbow trout gill
epithelial cells in culture.
AB - The biotransformation of xenobiotics and steroids was investigated in cultured
respiratory epithelial cells from rainbow trout (Oncorhynchus mykiss) gills. As a
first approach, ethoxyresorufin-O-deethylase (EROD), chosen as a marker of CYP1A
activity, was measured in monolayers of adherent cells. The induction of this
enzyme was studied in cells exposed to beta-naphthoflavone (BNF) or 2,3,7,8
tetrachlorodibenzo-p-dioxin (TCDD) in concentrations ranging from 10(-6) to 10(
12) M. After 24 h, TCDD showed a maximal induction at a concentration of 10(-9) M
while BNF showed a maximal induction at a concentration of 10(-7) M.
Concurrently, a variety of substrates involved in cytochrome P450-dependent
metabolism as well as phase II reactions, namely ethoxycoumarin, aniline and
testosterone were incubated with cultured gill cells for 2 or 8 h and with
freshly isolated hepatocytes for comparison. Our results revealed a significant
cytochrome P450-dependent activity in gill cells with ethoxycoumarin and aniline,
but no hydroxylation was observed with testosterone as substrate. No trace of
sulfate conjugate was detected. With 2.5 uM aniline as substrate, 2
hydroxyaniline accounted for 32.1% of the radioactivity after 2 h incubation
whereas acetanilide amounted to 6.4%. Significant differences were found between
gill cells and isolated hepatocytes in the capacity of these systems to conduct
oxidative and conjugating metabolic pathways. Qualitatively, the main difference
was observed for testosterone which is hydroxylated in position 6beta and 16beta
and conjugated to glucuronic acid in liver cells, whereas reductive
biotransformation giving rise to dihydrotestosterone and androstanediol and
traces of androstenedione were observed in gill cells. Quantitatively, the
biotransformation activity in gill epithelial cells, expressed as pmol/h per mg
protein, was between 1.5 and 14% of the activity level observed in isolated
hepatocytes, depending on the substrate.
PMID- 10686324
TI - DNA adducts in liver and leukocytes of flounder (Platichthys flesus)
experimentally exposed to benzo
AB - In the present study the levels of hydrophobic DNA adducts detected by 32P
postlabelling were followed in liver and leukocytes of flounder (Platichthys
flesus) over 10 days following single i.p. injections of two doses of BaP (10 and
50 mg kg(-1) fish weight, respectively). DNA adducts were detected in both
tissues of exposed fish 2 days post injection and continued to rise on day 5 and
day 10. In flounder exposed to the lower dose of BaP, the levels of hepatic DNA
adducts reached higher values on the fifth day compared with flounder exposed to
the higher dose. However, at the end of the experiment, the DNA adduct level was
again higher in fish from the high dose group compared with the low dose group.
There was no substantial increase of DNA adducts in liver of flounder from the
low dose group after day 5, while the adduct levels in flounder liver from the
high dose group increased throughout the experiment. Earlier studies detecting
DNA adducts in BaP-exposed flatfish with the 32P-postlabelling technique have
reported declining adduct levels from about 2 days after the exposure, regardless
of exposure route. In contrast, the results from our study did not confirm a
rapid increase and successive decline of hydrophobic adducts in liver of BaP
exposed flounder.
PMID- 10686325
TI - Cadmium and copper display different responses towards oxidative stress in the
kidney of the sea bass Dicentrarchus labrax.
AB - Copper and cadmium were i.p. injected into the fish Dicentrarchus labrax. Cu as
Cd-treated fish showed an enlargement of the lysosomal membrane of the kidney
(pronephros), Cu being more toxic than Cd. Following injection, metal uptake,
measured in muscle, liver and kidney, was much higher with cadmium treatment than
with copper, the kidney being the main accumulating organ of cadmium in which
metal accumulation is correlated with increased zinc level, suggesting
metallothionein induction. In vivo exposure to metal decreases the lysosomal
membrane stability of pronephros with a half dose of 127 ng g(-1) Cu and 735 ng
g(-1) Cd. Lipid peroxidation, expressed as malondialdehyde equivalents (MDA), and
catalase activity were measured in kidney subcellular fractions. When added in
vitro, Cu significantly raises the MDA level (365% at 200 uM), Cd having a lower
effect (20% at 500 uM). Catalase activity is significantly reduced by Cd whereas
Cu does not produce any significant effect at the tested concentrations. Results
suggest that although both metals cause in vivo damage to pronephros lysosomal
membrane, Cu activates the redox process generating oxyradicals but does not
affect in vitro the protective catalase activity unlike Cd which appears to
weakly participate in oxyradical generation but alters in vitro protective
catalase activity.
PMID- 10686326
TI - Determining the ecotoxicological mode of action of chemicals from measurements
made on individuals: results from instar-based tests with Daphnia magna Straus.
AB - A short-term Daphnia toxicity test design was used to assess the ecotoxicological
mode of action of pollutants. It was demonstrated that by exposing Daphnia
females over a single instar to three toxic substances (3,4-dichloroaniline,
cadmium and fluoranthene) it was possible to successfully measure both lethal
effects on egg and adult stages and nonlethal effects on food acquisition and
production rates. Dichloroaniline exposure reduced egg survival during
development at concentrations below those which affected adult survival or
production rates. For cadmium, however, concentration effects on production were
almost an order of magnitude lower than those which affected adult survival, and
no reductions in egg survival were observed. Responses to fluoranthene showed a
different pattern again, with egg survival during development and production
equally affected at concentrations which affected adult survival. Thus the three
pollutants chosen showed contrasting dominant ecotoxicological modes of action,
in terms of the relative importance of production and mortality effects, and this
could be easily assessed using a novel toxicity test design. These results have
important implications for risk assessment since with a relatively short, and
thus cost-effective test, the functional relationship between effects on
lethality and production rates and concentration can be determined.
PMID- 10686327
TI - Lindane increases in vitro respiratory burst activity and intracellular calcium
levels in rainbow trout (Oncorhynchus mykiss) head kidney phagocytes.
AB - Phagocytic cells are the main actors of the fish immune system. They secrete
reactive oxygen species (ROS) involved in their bactericidal activity. The
effects of lindane on ROS production in rainbow trout phagocytes are
contradictory. Here, we study the effects of high concentrations of lindane on
ROS production (by chemiluminescence) and on intracellular calcium levels
([Ca(2+)](i)) (by spectrofluorimetry) in trout phagocytes. In these cells,
lindane from 2.5 to 10 uM, increases ROS production and has no effect on
[Ca(2+)](i). From 25 to 200 uM, lindane leads to a rise in ROS production
(maximal value measured: 41152+/-6253 RLU for 100 uM lindane) associated with an
increase in [Ca(2+)](i) (+3149+/-96 nM for 100 uM lindane) and with cytotoxicity
which appears 2 min after addition of 100 uM lindane (25.4+/-3.75%; P<0.05). In
the absence of extracellular calcium, ROS production of lindane-treated cells
remains significantly higher than in controls (maximal value measured: 1899+/-254
RLU for 25 uM lindane), a significant decrease in [Ca(2+)](i) is observed in
cells treated with 5 or 10 uM lindane (-54+/-35 nM for 10 uM lindane), and an
increase in [Ca(2+)](i) in cells treated with 100 uM lindane (330+/-33 nM). The
rise in [Ca(2+)](i) induced by lindane is inhibited when cells are preincubated
with thapsigargin (Thaps). We conclude that lindane induces an increase in
[Ca(2+)](i)50 uM) alter Ca(2+) homeostasis in the absence of extracellular
Ca(2+), confirming that lindane can affect other intracellular stores of Ca(2+).
At low concentrations (<25 uM), lindane stimulates ROS production by Ca(2+)
independant mechanisms without inducing cytotoxicity. From 25 uM, lindane
increases [Ca(2+)](i) and maximal cytotoxicity appears from 100 uM lindane.
Lindane toxicity in fish phagocytes may be associated with high [Ca(2+)](i) and
high ROS production. Thus, ROS are beneficial in protection of the organism but
when ROS are produced in excess, they can be toxic for cells and tissues.
PMID- 10686328
TI - Cadmium influx and efflux across perfused gills of the shore crab, Carcinus
maenas.
AB - Cadmium influx across perfused gills of the shore crab Carcinus maenas exposed to
9.0 uM cadmium in the external medium ranged from 0.6 to 2.0 nmol Cd(2+) g(-1)
gill wet wt. per h. Cadmium efflux across perfused gills exposed to 9.0 uM
cadmium in the internal medium ranged from 0.3 to 0.9 nmol Cd(2+) g(-1) gill wet
wt. per h. There was no significant difference between cadmium influx and efflux
across the gills. Cadmium influx across the gills was not detectable after
exposure to lanthanum in the external medium, whereas cadmium efflux was
unaffected by external as well as internal lanthanum. Cadmium influx was not
affected when the internal medium was changed to Na-free medium, whereas efflux
showed a fourfold increase when the gills were perfused with Na-free medium. Low
pH in the external medium did not exert any significant effect on cadmium influx
and efflux.
PMID- 10686329
TI - Impact of the fungicide carbendazim in freshwater microcosms. I. Water quality,
breakdown of particulate organic matter and responses of macroinvertebrates.
AB - Effects of chronic application of the fungicide Derosal(R) (active ingredient
carbendazim) were studied in indoor macrophyte-dominated freshwater microcosms.
The concentrations (0, 3.3, 33, 100, 330 and 1000 ug/l) were kept at a constant
level for 4 weeks. This paper is the first of a series of two, and describes the
fate of carbendazim and its effects on water quality parameters, breakdown of
POM, and responses of macroinvertebrates. Carbendazim proved very persistent in
the water layer. Values for t(12) varied between 6 and 25 weeks, and decreased
with the treatment level. Significant effects on water quality parameters (DO,
pH, alkalinity, conductivity) could not be demonstrated. After 4 weeks of
incubation, the breakdown of Populus leaves was significantly slower at the two
highest carbendazim concentrations. The macroinvertebrate community was seriously
affected by carbendazim application, with Oligochaeta, Turbellaria, Hirudinea and
some Crustacea as the most sensitive groups. The snail Bithynia decreased in
numbers, but other gastropods increased in numbers. Safety factors as proposed by
the Uniform Principles (European Union) for the risk assessment of pesticides, to
be multiplied with toxicity data of the standard test species (Daphnia, fish,
algae), appeared to ensure adequate protection of sensitive populations present
in the microcosms.
PMID- 10686330
TI - Impact of the fungicide carbendazim in freshwater microcosms. II. Zooplankton,
primary producers and final conclusions.
AB - Effects of chronic application of the fungicide Derosal(R) (active ingredient
carbendazim) were studied in indoor macrophyte-dominated freshwater microcosms.
The concentrations (0, 3.3, 33, 100, 330 and 1000 ug/l) were kept at a constant
level for 4 weeks. This paper is the second of a series of two; it describes the
effects on zooplankton and primary producers and presents an overall discussion.
The zooplankton community was negatively affected by the three highest treatment
levels (NOEC(community)=33 ug/l). At higher treatment levels Cladocera taxa were
completely eliminated, while Copepod numbers were reduced. Rotatoria taxa
decreased (Keratella quadrata and Lecane sp.) or increased in abundance
(Testudinella parva) at the highest treatment level only. Due to the reduced
grazing pressure, the abundance of some phytoplankton taxa and the chlorophyll-a
content of the phytoplankton increased at the three highest treatment levels
(NOEC(community)=33 ug/l). This effect was not observed for the periphyton, most
probably because the reduced grazing pressure was compensated by the increased
abundance of some snail species such as Lymnaea stagnalis and Physella acuta. At
the end of the experimental period the biomass of the macrophyte Elodea nuttallii
was significantly elevated at the two highest treatment levels. It is
hypothesised that carbendazim might have caused, directly or indirectly, the
removal of pathogene organisms from the macrophyte.
PMID- 10686331
TI - Effects of food deprivation and handling stress on head kidney 17alpha
hydroxyprogesterone 21-hydroxylase activity, plasma cortisol and the activities
of liver detoxification enzymes in rainbow trout.
AB - The 21-hydroxylation of 17alpha-hydroxyprogesterone is one step in the
biosynthesis of corticosteroids. Both 7 days of handling-induced stress and 7
weeks of food deprivation significantly elevated head kidney microsomal 17alpha
hydroxyprogesterone 21-hydroxylase activity in juvenile rainbow trout. The
increased 21-hydroxylase activity was not paralleled by changes in plasma
cortisol levels induced by handling stress whereas food deprivation for 3 and 7
weeks increased both 21-hydroxylase activity and plasma cortisol levels
significantly. Food deprivation in rainbow trout affected detoxification enzyme
activities, namely glutathione-S-transferase (GST), uridine-di-phosphate
glucuronosyltransferase (UGT) and glutathione reductase (GR) activities in the
liver. Together our observations suggest that experimental conditions can affect
experimental results, especially the values of parameters like GST, UGT and GR.
Furthermore, alterations in the metabolic state of the liver caused by stress or
food deprivation can alter the balance between detoxification enzymes in rainbow
trout liver.
PMID- 10686332
TI - pH-dependent toxicity of copper and uranium to a tropical freshwater alga
(Chlorella sp.).
AB - Copper (Cu) and uranium (U) are of potential ecotoxicological concern to tropical
freshwater organisms in northern Australia as a result of mining activity. No
local data on the toxicity of these metals to tropical freshwater algae are
currently available. The aim of this study was to investigate the effect of pH
(5.7 and 6.5) on the toxicity of Cu and U to the green alga Chlorella sp. in a
synthetic softwater representative of fresh surface waters in sandy-streams of
tropical northern Australia. The effects of Cu and U on algal growth (cell
division) rate after a 72-h exposure were determined. Intracellular and
extracellular (membrane-bound) metal concentrations at the two selected pH values
were also compared. Based on the 72-h minimum detectable effect concentrations
(MDEC), Chlorella sp. was approximately 20-fold more sensitive to Cu (0.7 and 1.4
ug l(-1) at pH 6.5 and 5.7, respectively) than U (13 and 34 ug l(-1) at pH 6.5
and 5.7, respectively), and more sensitive than other Australian tropical
freshwater organisms. The toxicity of Cu and U was highly pH-dependent. Copper
concentrations required to inhibit growth (cell division) rate by 50% (72-h
EC(50)) increased from 1.5 to 35 ug l(-1) as the pH decreased from 6.5 to 5.7.
Similarly, the 72-h EC(50) values for U increased from 44 to 78 ug l(-1) over the
same pH range. Calculation of Cu and U speciation using the geochemical model
HARPHRQ, showed that differences in the concentrations of the free metal ions
(Cu(2+) and UO(2)(2+)) were only minimal (<10%) between pH 5.7 and 6.5. The
decreased toxicity at pH 5.7 was due to lower concentrations of cell-bound and
intracellular Cu and U compared to those at pH 6.5. These results are explained
in terms of the possible mechanism of competition between H(+) and the metal ion
at the cell surface.
PMID- 10686333
TI - Variations of manganese in the eggs of the Norway lobster, Nephrops norvegicus
(L.).
AB - The Norway lobster, Nephrops norvegicus, lives on sediments rich in manganese
(Mn). Temporal fluctuations of Mn in the eggs of N. norvegicus was investigated,
both in the field and in laboratory experiments. Female gonads and external eggs
of different developmental stages were measured for Mn. The Mn concentration
during oocyte maturation and throughout most of the embryogenesis (after
fertilisation) remained stable around 5 ug Mn g(-1) dry wt. egg. At the end of
the embryonic development (about 6 months after fertilisation) the Mn
concentration of the egg started to increase and had at the time of hatching
reached concentrations of 120 ug Mn g(-1) dry wt. egg. The egg shell was at this
stage highly permeable and Mn was taken up by the embryo and egg shell in equal
amounts.
PMID- 10686334
TI - Temporal variations of manganese in the haemolymph and tissues of the Norway
lobster, Nephrops norvegicus (L.).
AB - The Norway lobster, Nephrops norvegicus, lives on sediments rich in manganese
(Mn) and any dissolved Mn(2+) can readily be taken up by the animal. To
investigate temporal fluctuations of bioavailable Mn, a N. norvegicus fishing
ground on the Swedish west coast was repeatedly sampled every 2 months from
September 1992 to November 1994. The lobsters collected contained on average 91.7
ug Mn g(-1) dry wt. (S.E. 4.2, n=156). The oxygen saturation of the bottom water
proved to be negatively correlated with both the temperature of the water and the
Mn (concentration and total content) of the animal's haemolymph. The temporal
fluctuations in animal Mn load were however, small compared to spatial
differences found in an earlier study. There was an increase in the Mn
concentration of the lobster exoskeleton (from 56 to 340 ug Mn g(-1) dry wt.
exoskeleton) and gills (from 34 to 160 ug Mn g(-1) dry wt. gill) in postmoult
animals compared to premoult. The Mn concentrations of the lobsters'
hepatopancreas and muscle tissue remained relatively constant throughout the
moult cycle and appear to be more conservative in their Mn concentration and less
affected by exposure to Mn.
PMID- 10686335
TI - Thiobencarb-induced embryotoxicity in medaka (Oryzias latipes): stage-specific
toxicity and the protective role of chorion.
AB - Thiobencarb (S-(4-chlorobenzyl)-N,N-diethyl thiol carbamate) has been one of the
herbicides previously associated with fish kills in agricultural drains near the
Sacramento/San Joaquin rivers and their Delta. This area is an important spawning
ground for fish, and thus there are concerns over possible toxic effects on early
life stages of fishes. To define targets of thiobencarb embryotoxicity and to
determine the degree of protection afforded by the chorion, medaka (Oryzias
latipes) embryos were exposed under static nonrenewal conditions. Responses to
exposures initiated at blastula or at initiation of heart beat (stages 10 and 23,
respectively) were assessed. In addition, enzymatically dechorionated embryos
(stage 13, gastrula) were exposed and compared to responses in embryos with
intact chorions. Embryos were observed daily for development and for gross
abnormalities including: bradycardia, pericardial edema, hemostasis, poor yolk
resorption, cephalic and spinal deformities, and abnormal hatching. A subset was
also evaluated for histologic alterations. Based on gross abnormalities, the
concentration of thiobencarb affecting 50% (EC(50)) of embryos exposed at
blastula was 3.6 mg/l, while the putative no observable effect concentration
(NOEC) was 1.0 mg/l. For embryos exposed at onset of heart beat (stage 23), these
values were 4.1 and 2.5 mg/l, respectively. Dechorionated embryos tended to be
more sensitive than their chorionated cohorts (LC(50)=2.5 vs. 1.0 mg/l). Liver
histologic alterations were seen in chorionated embryos at EC(50) levels and
higher. Stage-specific toxicity was evident; nevertheless, the EC(50) and NOEC
values for embryos treated at stage 10 and stage 23 were similar.
PMID- 10686336
TI - A nose-to-nose comparison of the physiological effects of exposure to ionic
silver versus silver chloride in the European eel (Anguilla anguilla) and the
rainbow trout (Oncorhynchus mykiss).
AB - Physiological mechanisms of silver toxicity (as silver nitrate) to the sensitive
rainbow trout (Oncorhynchus mykiss) (96 h LC50: 10.2 ug silver l(-1), in soft,
low chloride water) and the more tolerant European eel (Anguilla anguilla)(96 h
LC50: 34.4 ug silver l(-1), in the same water) were investigated during acute
exposure to silver, using concentrations varying from 3 to 22 ug silver l(-1).
Silver was present either predominantly in the form of ionic silver, or in the
form of silver chloride complexes (AgCl(aq)). Inhibition of the branchial
Na(+),K(+)-ATPase enzyme activity and the active influx of Na(+) leading to net
Na(+) loss were the key toxic effect in both species. In the rainbow trout, but
not in the European eel, Cl(-) influx was also impaired during silver exposure.
However, even under control conditions, Cl(-) influx was negligible in the eel.
Water Cl(-) clearly protected against the silver-induced physiological
disturbance in rainbow trout, presumably by changing the speciation of silver
from ionic silver to AgCl complexes. However, such a protective effect was not
observed in the European eel. Differences in whole body Na(+) turnover rates
between the two species (1.1% per day in the European eel versus 19% per day in
the rainbow trout) together with the lack of effect of silver exposure on Cl(-)
homeostasis in the European eel are hypothesized to be the main reasons for the
different silver tolerance observed in the two species.
PMID- 10686337
TI - The teratogenic effects of methylmercury on early development of the zebrafish,
Danio rerio.
AB - Chronic bioassays were used to evaluate the concentration and exposure duration
of methylmercury that resulted in specific teratogenic defects in Danio rerio
embryos exposed at different developmental stages. Embryos in different stages of
development (cleavage, blastula, gastrula, or segmentation) were exposed to 20 or
30 ug/l of methylmercuric chloride (CH(3)HgCl) for various exposure durations (8,
16, 32 h, or continuously to hatching). These exposures frequently caused two
morphological defects, tissue abnormality in the median finfold and a flexure of
the posterior tail region. The critical period of exposure for the production of
both effects begins around 18-20 h after fertilization, with increased exposure
resulting in more severe effects. These critical periods coincide with both tail
and median finfold formation.
PMID- 10686338
TI - Chronic morphine exposure and the expression of heme oxygenase type 2.
AB - Heme oxygenase (HO) catalyzes the formation of carbon monoxide (CO) and other
products from heme. The CO formed has been shown to function as a
neurotransmitter, and may be involved in nociceptive signaling. Heme oxygenase
type 2 (HO-2) is the predominant form of HO in the CNS. The expression of nitric
oxide synthase (NOS) which catalyzes the formation of a similar neurotransmitter
nitric oxide (NO) from arginine is increased in the spinal cords of animals
chronically exposed to morphine and other opioids. In these studies, we examined
changes in expression of HO-2 which occur in spinal cord tissue of morphine
tolerant mice. After 5 days of exposure to morphine, mice were observed to be
profoundly tolerant to the analgesic effects of morphine. In experiments using
Northern blotting we observed a 2.7-fold increase in HO-2 mRNA in homogenized
spinal cord tissue. Additional experiments revealed a 3.1-fold increase in HO-2
protein which seemed to result from the increased expression of HO-2 in neurons
in the dorsal horn region of the spinal cord. To complement our expression
studies measured HO enzymatic activity in spinal cord homogenates and found a 2.1
fold increase in the tolerant animals. The functional significance of this
increased expression and activity is as yet unclear, but may be involved in the
acquisition of analgesic tolerance to opioids, dependence on opioids, or perhaps
the hyperalgesia reported after chronic exposure to opioids.
PMID- 10686339
TI - Expression of rat insulin-like growth factor binding protein-6 in the brain,
spinal cord, and sensory ganglia.
AB - Insulin-like growth factors (IGFs) are important trophic factors during
development as well as in the adult or damaged nervous system. Their trophic
actions are modulated by interactions with six distinct IGF binding proteins. The
mRNA expression profiles of binding proteins 2, 4 and 5 in the normal developing
and adult CNS are well characterized and are shown to have distinctive, non
overlapping distributions. The IGF binding protein-6 (BP6) is also expressed in
the CNS, however, details regarding its mRNA expression distribution in the
developing and adult nervous system is limited. BP6 has the unique property of
preferentially binding the IGF-II ligand. Coupled with the fact that this ligand
is the most abundantly expressed IGF in the adult CNS, this suggests that the IGF
II/BP6 complex has a unique role in modulating IGF-II function in the adult
brain. In this report the anatomical distribution of BP6 messenger RNA in the
developing and adult rat nervous system is presented. In the embryonic animal the
CNS expression is tightly restricted to trigeminal ganglia and, relative to the
rest of the embryo, this structure has the highest expression. The expression in
the forebrain and cerebellum does not occur until after postnatal day 21 and then
is primarily associated with GABAergic interneurons. The highest levels of
expression in the adult animal are in the hindbrain, spinal cord, cranial
ganglia, and dorsal root ganglia. These nuclei in the hindbrain and periphery
that express BP6 are all associated with the coordination of sensorimotor
function in the cerebellum, which indicates an important role for the BP6/IGF-II
complex in the function and maintenance of these systems.
PMID- 10686340
TI - Identification of specific histidine residues and the carboxyl terminus are
essential for serotonin N-acetyltransferase enzymatic activity.
AB - Melatonin is synthesized in pinealocytes of the pineal gland and in
photoreceptors of the retina. Synthesis rate from serotonin to melatonin is
controlled by the rapid and dramatic enzymatic increase in darkness of serotonin
N-acetyltransferase (arylalkylamine N-acetyltransferase, AA-NAT, EC 2.3.1.87) and
hydroxyindole-O-methyltransferase (HIOMT, EC 2.1.1.4). The primary structure of
these critical indoleamine enzymes is now known and the regulation of the enzyme
catalysis can be examined. As a first step, the conserved cysteine (C) and
histidine (H) residues were targeted for site-directed mutagenesis as potential
amino acid residues involved in the N-acetylation reaction of AA-NAT. Our studies
concluded that among 6 histidine (H) to alanine (A) mutations, three residues
(H110A, H118A, H120A) within the AA-NAT protein showed little or no enzymatic
activity, whereas the others (H28A, H70A, H125A) retained enzymatic activity,
compared to the unaltered AA-NAT protein. Cysteine to alanine mutations, C37A and
C177A, had no significant effect on the AA-NAT enzymatic activity; however, C61A
had a four-fold increase in K(m) for acetyl CoA and an altered sensitivity to the
thiol modification chemical, N-ethylmaleimide (NEM), implying that C61 may
participate in the acetyl CoA binding. Further studies examined the AA-NAT enzyme
regulation of the highly conserved carboxyl terminus. When 12 terminal amino acid
residues were deleted systematically from the carboxyl terminus of the 205 amino
acid residue AA-NAT protein, enzyme activity was retained. However, further
residue deletion resulted in enzyme activity plummeting, implicating that the
essential information either for the correct structural folding into an active
enzyme form or for enzyme stability is in the 193 residues. To test the relative
importance of the AA-NAT carboxyl terminal region, a single leucine (L) was
altered to alanine (A) or proline (P). Both mutants, either L193A or L193P, had a
marked decrease in AA-NAT enzymatic activity and a decrease in thermal stability,
suggesting the leucine, in addition to the cysteine and histidine residues, is
involved in either enzyme catalysis or stability. In light of the recently
reported three-dimensional structure of AA-NAT (17,18), the site-directed
mutagenesis data demonstrate experimentally the importance of essential amino
acid residues for acetyl CoA binding and AA-NAT activation.
PMID- 10686341
TI - Differential effect of structural modification of human dopamine transporter on
the inward and outward transport of dopamine.
AB - The effect of structural modification of the human dopamine transporter protein
on bi-directional transport was explored using site-directed mutagenesis and
rotating disk electrode voltammetry. The substrate-induced DA efflux, as inferred
from the K(m) or K(i), was dependent on common structural features for uptake of
the substrate inducer: reduced by beta-hydroxylation, stereoselective to alpha
methylation, and relatively insensitive to a switch of a single phenolic hydroxyl
group between m- and p-positions. The potencies for substrates to compete with
external DA for uptake and to induce DA efflux were similar and highly
correlated. Despite these similarities, the efflux of internal DA was
substantially slower than the uptake of its inducers. Mutation of serine-528 of
the hDAT to alanine (S528A) did not change the structure-activity relationships,
maximal uptake rates, and the cation dependence for the uptake of external
substrates, although it modestly reduced K(m) or K(i) of most tested substrates.
In contrast, it substantially enhanced substrate-induced DA efflux, with maximal
efflux rates doubled for all tested inducers. Simultaneous monitoring of tyramine
uptake and resulting DA efflux revealed that S528A accelerated the DA efflux
relative to tyramine uptake. Saturation analysis suggested that the mutation
significantly enhanced the efflux kinetics of internal DA but it exerted little
effect on the uptake kinetics of external DA. These findings suggest that Ser-528
may play a role in stabilizing a hDAT conformation unfavorable for outward
transport of internal DA, thereby contributing to the efficiency of the
transporter.
PMID- 10686342
TI - Intracerebral injection of caspase-3 inhibitor prevents neuronal apoptosis after
kainic acid-evoked status epilepticus.
AB - In the aftermath of prolonged continuous seizure activity (status epilepticus,
SE), neuronal cell death occurs in the brain regions through which the seizure
propagates. Recent studies have implicated apoptotic processes in this seizure
related injury. Because activation of caspase-3-like cysteine proteases plays a
crucial role in mammalian neuronal apoptosis, we explored the possibility that
activation of caspase-3 is involved in the neuronal apoptotic cell death that
occurs in rat brain following SE induced by systemic kainic acid. Caspase-3
activity was determined immunocytochemically using CM1 antibodies specific for
catalytically active subunit (p17) of the enzyme. We found an induction of
caspase-3 activity in rhinal cortex and amygdala at 24 h after SE. To determine
whether activation of caspase-3-like proteases is a necessary component of the
injury process, we delivered a caspase-3 inhibitor, z-DEVD-fmk, into the lateral
ventricle prior to, and following SE. z-DEVD-fmk treatment substantially
attenuated apoptotic cell death after SE, both in hippocampus and rhinal cortex,
as evaluated by analysis of internucleosomal DNA fragmentation and neuronal
nuclear morphology. Our findings implicate caspase-3 cysteine protease in the
neurodegenerative response to SE and suggest that this degeneration can be
attenuated by inhibition of caspase-3-like enzyme activity.
PMID- 10686343
TI - The 5'2 promoter of the neuronal nitric oxide synthase dual promoter complex
mediates inducibility by nerve growth factor.
AB - Neuronal nitric oxide synthase (nNOS) is induced by nerve growth factor (NGF) in
pheochromocytoma PC12 cells. Previous studies from our laboratory identified two
closely linked promoters (designated 5'1 and 5'2) that mediate transcription of
the human nNOS gene in the brain [J. Xie, P. Roddy, T.K. Rife, F. Murad, A.P.
Young, Two closely linked but separable promoters for human neuronal nitric oxide
synthase gene transcription, Proc. Natl. Acad. Sci. U. S. A. 92 (1995) 1242
1246]. In this report, we demonstrate that luciferase fusion genes under
transcriptional control by the 5'1 and 5'2 dual promoter complex are inducible by
NGF in stably transformed PC12 cells. In sharp contrast, neither epidermal growth
factor (EGF) nor fibroblast growth factor 2 (FGF2) are able to significantly
enhance the expression of NOS-luciferase fusion genes. Deletion studies indicate
that the 5'2 promoter plays a major role in mediating NGF inducibility. The 5'2
promoter contains six potential Ets binding sites as well as four potential AP1
binding sites. Thus, it is possible that activation of Ets and/or AP1
transcription factors by the Ras-Raf-MAP kinase cascade contributes to the NGF
mediated induction of nNOS.
PMID- 10686344
TI - Identification of a brain specific protein that associates with a refsum disease
gene product, phytanoyl-CoA alpha-hydroxylase.
AB - Refsum disease is an autosomal recessive neurologic disorder of the lipid
metabolism. Major diagnostic clinical findings include retinitis pigmentosa,
peripheral polyneuropathy, cerebellar ataxia, increased cerebrospinal fluid
protein without pleocytosis, nerve deafness, and cardiac involvement. We have
identified a novel protein (PAHX-AP #1) associated with phytanoyl-CoA alpha
hydroxylase (PAHX), a Refsum disease gene product, using the yeast-based two
hybrid assay. The middle portion (amino acids 83-264) of PAHX was used as a bait
and a mouse brain cDNA library was searched. The ability of PAHX-AP #1 to
interact with PAHX was confirmed using immunoprecipitation and Western blot
studies in NIH3T3 cells which stably expressed both PAHX and PAHX-AP #1. Northern
and Western blot analyses demonstrated a unique pattern of developmental PAHX-AP
#1 expression which was targeted to the adult brain, but ubiquitous expressions
of PAHX were observed in all examined tissues. In situ hybridization analyses of
the brain showed specific localization of PAHX-AP #1 to the supragranular layer
in the cerebral cortex, dentate gyrus, hippocampus, Purkinje cell layer, deep
cerebellar nucleus, trigeminal nucleus, abducent nucleus, facial nucleus,
cochlear and vestibular nucleus, ganglion cell and nuclear layer of the retina.
These data indicate that localization of PAHX-AP #1 in the brain is correlated
with central neurologic symptoms of Refsum disease such as retinitis pigmentosa,
cerebellar ataxia, nerve deafness and suggest that PAHX-AP #1 may be involved in
the development of the central neurologic deficits of Refsum disease.
PMID- 10686345
TI - Kindling modulates the IL-1beta system, TNF-alpha, TGF-beta1, and neuropeptide
mRNAs in specific brain regions.
AB - Cytokines and neuropeptides may be involved in seizure-associated processes.
Following amygdala kindling in rats, we determined alterations of IL-1beta, IL-1
receptor antagonist (IL-1Ra), IL-1 receptor type I (IL-1RI), IL-1 receptor
accessory proteins (IL-1R AcPs) I and II, TNF-alpha, TGF-beta1, neuropeptide Y
(NPY), glycoprotein 130 (gp 130) and pro-opiomelanocortin (POMC) mRNA levels in
the parietal, prefrontal and piriform cortices, amygdala, hippocampus and
hypothalamus. Messenger RNAs expression in all brain regions was determined 2 h
or 3 weeks following the last generalized convulsive seizure triggered from the
ipsilateral kindled amygdala. The same brain region sample was used to assay for
changes of all mRNA components. The results show that the 2 h-kindled group
exhibited a significant up-regulation of IL-1beta, IL-1RI, TNF-alpha and TGF
beta1 mRNAs in all three cortical brain regions, amygdala and hippocampus. The
largest up-regulation occurred in the prefrontal cortex (about 30-fold induction
for IL-1beta and TNF-alpha mRNAs). IL-1R AcP I and II mRNA levels were also up
regulated in the cortical regions. No changes in IL-1beta, IL-1RI or TNF-alpha
mRNA levels occurred in the 3 week-kindled group. NPY mRNA levels increased in
the hippocampus, prefrontal and piriform cortices in the 2 h-kindled group, while
IL-1Ra, gp 130, or POMC mRNA levels did not change in any group. The overall
profile of mRNA changes shows specificity of transcriptional modulation induced
by amygdala kindling. The data support a role of cytokines and NPY in the
adaptive mechanisms associated with generalized seizure activity, with
implications for neuroprotection, neuronal dysfunction and vulnerability
associated with epileptic activity.
PMID- 10686346
TI - Central origin of IL-1beta produced during peripheral inflammation: role of
meninges.
AB - Brain expression of Interleukin-1beta (IL-1beta) and its modulation have been
extensively documented in different animal models. The majority of the studies
were based on techniques such as RT-PCR, RIA and ELISA using global extracts.
Meningeal tissue or choroid plexus both belong to the peripheral compartment.
Thus, their presence in nervous tissue extracts may lead to erroneous
interpretations. We measured IL-1beta mRNA in the cerebellum, hippocampus and
cerebral cortex collected with meninges and in the same structures collected
without meninges after a peripheral lipopolysaccharide (LPS) stimulation (0.5
microgram/g body weight), using RT-PCR. The presence of meninges in the extracts
dramatically increased IL-1beta mRNA levels after LPS treatment while basal
levels (before LPS injection) were not affected. Indeed, two-thirds of the
response originated from the meningeal tissue and choroid plexus.
Immunohistochemical studies showed that IL-1beta labelled cells, identified as
macrophages, were exclusively localized in the ventricular and meningeal spaces,
in our LPS condition treatment. These results point out the need of integrated
analyses of data obtained with different techniques to demonstrate the presence
in the nervous tissue of a molecule which is also widely expressed in the
peripheral compartment.
PMID- 10686347
TI - Time-dependent changes in dopamine D(2)-receptor mRNA in the arterial chemoreflex
pathway with chronic hypoxia.
AB - The hypoxic ventilatory response (HVR) can be modulated by dopamine D(2)
receptors (D(2)-R) in both the carotid body arterial chemoreceptors and the
nucleus tractus solitarius (NTS), the primary synapse site of carotid body
afferents. We hypothesized that chronic hypoxia alters D(2)-R gene expression to
initiate changes in D(2)-R modulation of the HVR and enhance ventilatory
acclimatization to hypoxia. Thus, we used a competitive reverse transcription
polymerase chain reaction (RT-PCR) method to quantify changes in D(2)-R mRNA
levels in the rat carotid body and NTS after 0, 6, 12, 24, 48, or 168 h of
hypobaric hypoxia (P(IO(2))=80 Torr). In the rostral NTS, hypoxia significantly
increased D(2)-R mRNA at all time points. In the caudal NTS, D(2)-R mRNA levels
initially increased in response to hypoxia and then significantly decreased to
71+/-5% and 71+/-6% of control after 48 and 168 h of hypoxia, respectively. In
the carotid body, D(2)-R mRNA levels significantly decreased to 59+/-2% of
control after 48 h of hypoxia; however, they significantly increased to 274+/-22%
of control after 168 h. These results suggest that changes in D(2)-R mRNA in the
arterial chemoreflex pathway and corresponding changes at the protein and
signaling levels may contribute to the time-dependent changes in ventilation
observed with chronic hypoxia. Specifically, decreased carotid body inhibition by
D(2)-R could increase the HVR after 2 days of hypoxia.
PMID- 10686348
TI - In vivo NMDA/dopamine interaction resulting in Fos production in the limbic
system and basal ganglia of the mouse brain.
AB - Glutamatergic and dopaminergic effects on molecular processes have been
extensively investigated in the basal ganglia. It has been demonstrated that NMDA
and dopamine D(1) and D(2) receptors interact in the regulation of signal
transduction and induction of transcription factors. In the present experiments,
NMDA/dopamine interactions were investigated in the normosensitive caudate
nucleus, hippocampus and amygdala by monitoring Fos production. We demonstrated
that NMDA and the D(1) receptor agonist SKF 38393 triggered Fos levels in a
distinct, non-overlapping and region-specific pattern. NMDA injected
intraperitoneally (i.p.) elevated Fos levels in all hippocampal subfields and the
central amygdala, whereas SKF 38393 triggered Fos production in basomedial,
cortical, medial amygdala and caudate nucleus. The NMDA receptor antagonist CGS
19755 prevented NMDA- and SKF 38393-triggered Fos production in all investigated
brain areas. Similarly, the D(1) receptor antagonist SCH 23390 inhibited the
effects produced by SKF 38393 or NMDA. The D(2) receptor antagonist sulpiride
exerted synergistic and antagonistic effects on NMDA- and SKF 38393-triggered Fos
production, in a region specific manner. These data suggest that NMDA and
dopamine receptors regulate Fos production within the limbic system and basal
ganglia through regionally differentiated but interdependent actions.
PMID- 10686349
TI - Upregulation of cytosolic branched chain aminotransferase in substantia nigra
following developmental striatal target injury.
AB - We have previously shown that apoptotic cell death can be induced in substantia
nigra (SN) by developmental striatal target lesion. In this model, only a portion
of nigral neurons dies, so it provides a paradigm to examine not only the
molecular basis of cell death, but also the cellular responses of adjacent
neurons which survive. Using a differential display approach, we have found that
cytosolic branched chain aminotransferase (BCATc) mRNA is upregulated in SN in
this model. This upregulation is associated with an increased number of BCATc
positive neuronal profiles, demonstrated by immunostaining. BCATc-positive
neurons show normal morphology and rarely contain apoptotic chromatin. We
conclude that BCATc is upregulated in neurons, which are likely to survive, and
plays a role in either maintenance of viability or restoration of normal
function.
PMID- 10686350
TI - Two molecular forms of gonadotropin-releasing hormone (GnRH-I and GnRH-II) are
expressed by two separate populations of cells in the rhesus macaque
hypothalamus.
AB - Gonadotropin-releasing hormone represents the primary neuroendocrine link between
the brain and the reproductive axis, and at least two distinct molecular forms of
this decapeptide (GnRH-I and GnRH-II) are known to be expressed in the forebrain
of rhesus macaques (Macaca mulatta). Although the distribution pattern of the two
corresponding mRNAs is largely dissimilar, their expression appears to show some
overlap in specific regions of the hypothalamus; this raises the possibility that
some cells express both molecular forms of GnRH. To resolve this issue, double
label histochemistry was performed on hypothalamic sections from six male rhesus
macaques, using a monoclonal antibody to GnRH-I and a riboprobe to monkey GnRH-II
mRNA. In total, more than 2000 GnRH neurons were examined but in no instance were
GnRH-I peptide and GnRH-II mRNA found to be coexpressed. This finding emphasizes
that GnRH-I and GnRH-II are synthesized by two distinct populations of
hypothalamic neurons, and suggests that they may be regulated by different
neuroendocrine pathways.
PMID- 10686351
TI - Multistep expression and assembly of neuronal nicotinic receptors is both host
cell- and receptor-subtype-dependent.
AB - We tested the hypothesis that the folding, assembly and insertion of neuronal
nicotinic receptors are critically dependent on the host cell line. We used
recombinant adenoviruses encoding either the rat alpha7, alpha4 or beta2 subunits
in which expression of the subunit is controlled by a tetracycline-dependent
promoter to screen five cell lines (GH4C1, SH-EP1, CV1, SN-56, and CHO-CAR). All
five lines do not express detectable nicotinic receptor but do express receptor
for human adenovirus, and all expressed mRNA for alpha7, alpha4 and beta2
subunits when infected with viruses. Each cell line expressed varying levels of
alpha4beta2 receptors that bound [3H]cytisine, but only the GH4C1 and SH-EP1 cell
lines expressed either surface or internal alpha7 receptors that bound
[125I]alpha-bungarotoxin ([125I]alpha-BGT). All five cell lines expressed a 60
kDa protein immunoblotted by anti-alpha7 antibodies when infected with the alpha7
virus, presumably representing unassembled alpha7 subunits. In addition, GH4C1
cells expressed over 10-fold more surface alpha7 receptor than SH-EP1 cells, even
though the total alpha7 receptor in the two cell lines was similar. Sedimentation
experiments indicate that SH-EP1 cells only partially assemble alpha7 receptors
compared with GH4C1 cells and control alpha7 from rat brain. These data suggest
that not only is surface alpha7 receptor expression a multistep process, but that
each step may involve cell-specific assembly factors.
PMID- 10686352
TI - The Xenopus clock gene is constitutively expressed in retinal photoreceptors.
AB - Many aspects of normal retinal physiology are controlled by a retinal circadian
clock. In Xenopus laevis, the photoreceptor cells within the retina contain a
circadian clock that controls melatonin release. In this report we present the
cloning and characterization of the Xenopus homolog of the Clock gene, known to
be critical for normal circadian behavioral rhythms in the mouse. The Xenopus
Clock gene is expressed primarily in photoreceptors within the eye and is
expressed at constant levels throughout the day. Analysis of other tissues
revealed that, as in other species, the Xenopus Clock gene is widely expressed.
This characterization of the Clock gene provides a useful tool for further
exploration of the role of the circadian clock in normal retinal function.
PMID- 10686353
TI - Heat shock proteins Hsp27 and Hsp32 localize to synaptic sites in the rat
cerebellum following hyperthermia.
AB - Stressful stimuli activate the heat shock (stress) response in which a set of
heat shock proteins (hsps) is induced, which play roles in cellular repair and
protective mechanisms. Most studies in the mammalian nervous system have focused
on Hsp70, however, the present investigation targets other members of the induced
set, namely Hsp27 and Hsp32. In response to hyperthermia, these hsps are strongly
induced in Bergmann glial cells in the rat brain and transported into their
radial fibers, which project into the 'synaptic-enriched' molecular layer of the
cerebellum. Using subcellular fractionation and immunoelectron microscopy,
hyperthermia-induced Hsp27 and Hsp32 were detected in synaptic elements and in
perisynaptic glial processes. These results suggest that stress-induced Hsp27 and
Hsp32 may contribute to repair and protective mechanisms at the synapse.
PMID- 10686354
TI - Guanylyl cyclase-B represents the predominant natriuretic peptide receptor
expressed at exceptionally high levels in the pineal gland.
AB - The generation and function(s) of the signalling molecule cyclic GMP (cGMP) in
brain are still poorly understood. One mechanism to raise intracellular cGMP
levels is binding of C-type natriuretic peptide (CNP) to a membrane guanylyl
cyclase (GC), termed GC-B. Here, we demonstrate an exceptionally strong
expression of GC-B in the pineal gland. Crosslinking experiments performed with
125I-Tyr(0)-CNP and membranes from various rat tissues identified the receptor as
a 130-kDa protein, expressed at highest levels in pineal membranes. Receptor
autoradiography on brain sections confirmed a striking density of CNP binding
sites in pineal tissue, whereas binding sites for the related atrial natriuretic
peptide (ANP) predominate in other regions of the brain. Incubations of freshly
dissected whole pineal glands in either the absence or presence of natriuretic
peptides followed by immunohistochemical analyses of cGMP revealed strong
accumulations of cGMP in response to CNP but not to ANP in the majority of
pinealocytes. Stimulation of soluble GC (sGC) activity by use of sodium
nitroprusside (SNP) resulted in a very similar pattern of cGMP immunostaining,
indicating a co-expression at high levels of particulate and soluble forms of GC.
These findings point to a major role of cGMP signalling in pinealocytes and
suggest an important regulatory function for CNP.
PMID- 10686355
TI - Age-dependent increase in C7-1 gene expression in rat frontal cortex.
AB - We have previously reported that a fragment of mRNA, denoted as C7-1, which
expression was significantly increased in the frontal cortex of aged rats. In the
present study, we have cloned and sequenced the full length cDNA of the C7-1
gene. We have found that the open reading frame of this gene encoded a 463-amino
acid protein, which shared 84% identity in amino acid sequence with a subunit of
vacuolar H(+)-ATPase (V-ATPase). Further Northern blot analysis revealed that
there was an age-dependent increase in C7-1 gene expression in rat frontal
cortex, but not in other brain areas. Moreover, application of C7-1 antisense
oligonucleotide to cortical neuronal cultures markedly inhibited cell survival.
These results together suggest that C7-1 is a marker for the aging process and
that upregulation of C7-1 may be important in maintaining the normal function of
V-ATPase during aging.
PMID- 10686356
TI - Fragile X (fmr1) mRNA expression is differentially regulated in two adult models
of activity-dependent gene expression.
AB - We sought to determine whether the fragile X mental retardation gene fmr1 is
regulated in long-term potentiation (LTP) and electroconvulsive shock (ECS). In
situ hybridization of fmr1 mRNA in hippocampus of rats given LTP in vivo showed
no change in fmr1 mRNA levels relative to control. However, ECS induced a
selective increase in fmr1 mRNA expression in the dentate gyrus (DG) granule cell
layer at 6 h post-ECS. The ECS paradigm may unmask relevant activity-dependent
regulatory mechanisms that modulate fmr1 gene transcription in vivo.
PMID- 10686357
TI - Circadian variation in BDNF mRNA expression in the rat hippocampus.
AB - BDNF mRNA levels in the hippocampus were studied during the circadian cycle by in
situ hybridization. These levels display a circadian pattern, which may be due to
regulation by corticosterone. This may have consequences for hippocampal
functioning at different time points of the circadian cycle.
PMID- 10686358
TI - Cloning and distribution of the rat parkin mRNA.
AB - We have isolated by RT-PCR and sequenced a partial cDNA coding for the rat
homolog of parkin, a gene mutated in autosomal recessive juvenile parkinsonism.
The 1.46 kb rat cDNA clone contains a 1376 bp coding sequence that shares strong
similarity with the human parkin cDNA. RT-PCR and in situ hybridization revealed
widespread expression of parkin in the rat brain and the periphery. The
availability of the rat parkin cDNA and the initial elucidation of its
distribution should facilitate further research on the pathophysiological role of
parkin in the nervous system.
PMID- 10686359
TI - Vzg-1/lysophosphatidic acid-receptor involved in peripheral pain transmission.
AB - The nociception by intraplantar (i.pl.) lysophosphatidic acid (LPA) injection was
significantly, but partially blocked when mice received intrathecal (i.t.)
antisense oligodeoxynucleotide treatment for the vzg-1 type LPA-receptor. The
residual LPA-nociception observed under the condition of pertussis toxin
treatment, which is expected to block presynaptic contribution, was abolished by
diphenhydramine (i.pl.), an H1-type histamine receptor antagonist. Taking into
account that vzg-1 mRNA was detected in the dorsal root ganglion by RT-PCR
method, these findings suggest that the LPA-induced nociception is attributed to
the mechanism through vzg-1 receptor on nociceptor endings, and to that through
unidentified LPA-receptor on peripheral, possibly mast cells.
PMID- 10686360
TI - To err is human.
PMID- 10686361
TI - ERP components on reaction errors and their functional significance: a tutorial.
AB - Some years ago we described a negative (Ne) and a later positive (Pe) deflection
in the event-related brain potentials (ERPs) of incorrect choice reactions
[Falkenstein, M., Hohnsbein, J., Hoormann, J., Blanke, L., 1990. In: Brunia,
C.H.M., Gaillard, A.W.K., Kok, A. (Eds.), Psychophysiological Brain Research.
Tilburg Univesity Press, Tilburg, pp. 192-195. Falkenstein, M., Hohnsbein, J.,
Hoormann, J., 1991. Electroencephalography and Clinical Neurophysiology, 78, 447
455]. Originally we assumed the Ne to represent a correlate of error detection in
the sense of a mismatch signal when representations of the actual response and
the required response are compared. This hypothesis was supported by the results
of a variety of experiments from our own laboratory and that of Coles [Gehring,
W. J., Goss, B., Coles, M.G.H., Meyer, D.E., Donchin, E., 1993. Psychological
Science 4, 385-390. Bernstein, P.S., Scheffers, M.K., Coles, M.G.H., 1995.
Journal of Experimental Psychology: Human Perception and Performance 21, 1312
1322. Scheffers, M.K., Coles, M. G.H., Bernstein, P., Gehring, W.J., Donchin, E.,
1996. Psychophysiology 33, 42-54]. However, new data from our laboratory and that
of Vidal et al. [Vidal, F., Hasbroucq, T., Bonnet, M., 1999. Biological
Psychology, 2000] revealed a small negativity similar to the Ne also after
correct responses. Since the above mentioned comparison process is also required
after correct responses it is conceivable that the Ne reflects this comparison
process itself rather than its outcome. As to the Pe, our results suggest that
this is a further error-specific component, which is independent of the Ne, and
hence associated with a later aspect of error processing or post-error
processing. Our new results with different age groups argue against the
hypotheses that the Pe reflects conscious error processing or the post-error
adjustment of response strategies. Further research is necessary to specify the
functional significance of the Pe.
PMID- 10686362
TI - Is the 'error negativity' specific to errors?
AB - When subjects make an erroneous response in a choice reaction time task, an error
negativity, or error-related negativity (N(E)/ERN), peaking at about 100 ms after
EMG onset, has been described. This wave is often considered to be absent on
correct response trials. We report a small N(E)/ERN wave on correct response
trials during a choice reaction time task in which surface Laplacians were
estimated by the source derivation method. This wave is well focused at FCz, and
its time course is the same for correct responses trials, incorrect sub-threshold
EMG activation trials, and error trials. Current source density maps, also
indicate a focus at FCz. A second experiment showed the existence of a N(E) at
FCz on correct trials during a simple RT task. Rather than an error detection
process per se, we propose that the N(E)/ERN reflects either a comparison process
leading secondarily to error detection, or an emotional reaction.
PMID- 10686363
TI - Different error types and error processing in spatial stimulus-response
compatibility tasks: behavioural and electrophysiological data.
AB - We tested the hypothesis that in spatial stimulus-response-compatibility (SRC)
tasks two different error types occur: A noise-induced 'general error'
independent of SRC and reaction time and a 'position driven error' in
incompatible trials with short RT being driven by the irrelevant stimulus
position. A second issue was whether error detection is different for these two
types of errors, which should be reflected by differences in the error negativity
(Ne), since the Ne is seen as a neural correlate of error detection. To study
these issues, we used a Simon- and a spatial Stroop-task. In incompatible (vs.
compatible) trials we found more errors and a below chance accuracy in fast
responses. Neither the amplitude nor the latency of the Ne were significantly
affected by the experimental factors. This pattern of behavioural results
supports the above hypothesis of two error types in such tasks. The Ne results
indicate that error detection is similar for both types of errors.
PMID- 10686364
TI - Error, stress and the role of neuromotor noise in space oriented behaviour.
AB - In this article both movement errors and successful movements are considered to
be the product of varying ratios of muscle force signals and the composite of
neuromotor noise in which the force signal is embedded. Based on earlier work we
derived four propositions, which together form a theoretical framework for
understanding the incidence of error in conditions of time pressure and mental
load. These propositions are: (1) motor behaviour is an inherently stochastic and
therefore noisy process; (2) biophysical, biomechanical and psychological factors
all contribute to the level of neuromotor noise in a movement signal; (3)
endpoint variability of movement is related to the signal-to-noise ratio of the
forces which drive the moving limb to the target; and (4) optimal signal-to-noise
ratios in motor output can be arrived at by adjusting limb stiffness. In an
experiment with a graphical aiming task in which subjects made pen movements to
targets varying in width and distance, we tested the prediction that time
pressure and dual task load would influence error rates and movement noisiness,
together resulting in biomechanical adaptations of pen pressure. The latter is
seen as a manifestation of a biomechanical filtering strategy to cope with
increased neuromotor noise levels. The results confirmed that especially under
time pressure error rates and movement noise were enhanced, while pen pressure
was higher in both conditions of stress.
PMID- 10686365
TI - Mechanisms of speed-accuracy tradeoff: evidence from covert motor processes.
AB - Speed-accuracy tradeoff (SAT) refers to the inverse relation between speed and
accuracy found in many tasks. The present study employed reaction times (RTs) and
movement-related brain potentials arising during the RT interval (lateralized
readiness potentials; LRPs) to examine the mechanisms by which people control
their position along an SAT continuum. Many models of SAT postulate that changes
in position across conditions (macro-tradeoffs) and trial-by-trial variations
within conditions (micro-tradeoffs) are mediated, at least in part, by the same
mechanisms. These include: (1) all models that postulate mixtures of guesses and
accurate responses and (2) some models postulating decision criterions applied to
accumulating evidence or response tendencies. Such models would seem to be
rejected for conditions under which macro- and micro-tradeoffs can be shown to
involve no stages of RT in common. Under the present conditions, the two types of
SAT produced additive effects on RT, with the macro-tradeoff involving only that
portion of the RT interval occurring after LRP onset and the micro-tradeoff
involving only that portion before LRP onset. These findings imply that the two
types of SAT arose during different serial stages of RT and that the macro
tradeoff involved only stages occurring after differential preparation of the two
hands had begun.
PMID- 10686366
TI - Age effects on response monitoring in a mental-rotation task.
AB - A mental-rotation task was presented to young (18-28 years) and old (60-76 years)
adults to simultaneously assess age-related changes in performance, response
monitoring and adaptive behavior. Relative to young participants, older adults
were less inclined to adjust their speed at the expense of accuracy. They
displayed a larger number of slow errors, smaller error potentials (Ne and Pe),
more immediate corrections of errors when detected, and a larger speed reduction
on trials following an error. The data suggest that for older adults an increase
of task complexity sometimes caused a radical failure in determining the correct
response, rather than a gradual reduction of efficiency.
PMID- 10686367
TI - Brain mechanisms of selective learning: event-related potentials provide evidence
for error-driven learning in humans.
AB - Selective learning has been observed in Pavlovian conditioning in animals and in
judgements of event contingencies in humans. This analogy led to the suggestion
that the formation of associations underlies both types of learning. An
alternative theory proposes that both tasks involve the computation of event
contingencies as prescribed by probability theory. Error-driven models of
learning incorporate trial-by-trial error-correction mechanisms during training
whereas probabilistic models view learning merely as the storage of frequency
information for later use during judgement of event contingencies. Competitive
interaction between cues was observed in a contingency judgement task. Event
related brain potentials (ERPs) provided evidence for brain events related to the
discrepancy between actual and expected outcomes during training thus supporting
error-driven accounts of selective learning.
PMID- 10686368
TI - Motor control and state regulation in children with ADHD: a cardiac response
study.
AB - The goal of the current study was to investigate whether poor motor control in
children with Attention-Deficit Hyperactivity Disorder (ADHD) was associated with
a state regulation deficit. For this purpose, 28 ADHD and 22 healthy children
carried out two Go No-Go tests: one with a fast stimulus presentation rate, and
the other with a slow stimulus presentation rate. Groups were compared on RT
performance and on specific cardiac measures, reflecting arousal, motor
activation/inhibition, and effort allocation. No group difference in the arousal
measure (mean heart rate) was found. Further, groups did not differ with respect
to response inhibition: in both the fast and slow condition, ADHD children made
comparable numbers of errors of commission to the control group, and the groups
did not differ with respect to the heart rate deceleration after the onset of the
No-Go signal, reflecting motor inhibition. Group differences were found with
respect to motor activation and effort allocation in the condition with a slow
presentation rate. In this condition: (1) ADHD children reacted more slowly to Go
signals than control children, suggesting poor motor activation; (2) the heart
rate deceleration before the onset of Go signals, which is believed to reflect
motor preparation, was less pronounced in the ADHD children; (3) after Go
signals, where a response was given, the cardiac shift from deceleration to
acceleration, indicating response initiation, was delayed in ADHD children; and
(4) ADHD children had greater heart rate variability (0.10 Hz component) than the
control group, indicating that less effort was allocated. No group differences in
motor activation and effort allocation were found in the condition with a fast
presentation rate of stimuli. We conclude, therefore, that a slow presentation
rate of stimuli brings the ADHD child in a non-optimal activation state.
PMID- 10686369
TI - Event-related potentials elicited by wrong terminal notes: effects of temporal
disruption.
AB - Wrong terminal notes of familiar musical phrases are known to elicit a large
positive deflection of the event-related potential (ERP). The present study
examined whether the effect of wrong terminal notes on ERP was modulated by the
timing of their occurrence. Sixteen non-musicians were asked to rate the
congruity of the endings of 50 well-known musical phrases. Four different types
of endings were made for each phrase by manipulating the timing (well-timed vs.
delayed for 750 ms) and pitch (correct vs. wrong) of the last note orthogonally.
These ending patterns were presented equiprobably in an unpredictable order.
Wrong notes elicited large late positive waves irrespective of the timing of
occurrence. When the notes were delayed, however, the positive waves were reduced
in amplitude to about 50% of those elicited by well-timed notes. These results
suggest that the temporal (rhythmic) structure of musical phrases strongly
influences the processing of melodic information.
PMID- 10686370
TI - Flavour conditioning and alcohol: a multilevel model of individual differences.
AB - Previous research shows that dependent drinkers respond more strongly to alcohol
related cues and suggests that alcohol cue-reactivity may be relevant to
understanding dependence liability. However, a significant weakness in many
studies is the fact that cue-reactivity is studied without actually conditioning
subjects; responses to alcohol-related cues are simply assumed to be conditioned
responses. The current report attempts to overcome this weakness by studying
alcohol cue-reactivity following a flavour-conditioning procedure. A statistical
model of individual differences in cue-reactivity was constructed using previous
alcohol exposure, alcohol tolerance, and personality as predictor variables.
Although there was no evidence for overall differences in subjective and
psychophysiological responses to alcohol and soft-drink paired flavours, there
were marked individual differences in responding to the different flavours. The
statistical model showed that reward sensitivity (high extroversion, high
neuroticism), heavier levels of drinking, and higher levels of tolerance to the
intoxicating effects of alcohol were associated with lower levels of skin
conductance in the presence of alcohol paired flavours.
PMID- 10686371
TI - Scopolamine impairs memory performance and reduces frontal but not parietal
visual P3 amplitude.
AB - It has been suggested that the P3 event-related potential (ERP) may mark the
operation of certain working or long-term memory processes. It has also been
reported that cholinergic blockade by scopolamine induces significant memory
impairment and is associated with an increased latency, as well as amplitude
reduction or abolition of the auditory P3, thus supporting hypothesised links
between P3 and long-term memory function. An intriguing anomaly is that, while
visual P3 latency is also increased by scopolamine, amplitude is not changed. The
aim of this study was to make a more detailed assessment of the effects of
scopolamine on the visual P3 at a drug dose known to induce memory impairment.
After drug administration, memory performance was significantly impaired and
visual P3 latency was significantly increased. There was little evidence of
parietal P3 amplitude reduction, but frontal P3 amplitude was significantly
reduced in both target and non-target conditions. These findings, when considered
in the light of a more recent study of the effects of scopolamine on auditory P3,
suggest that cholinergic blockade produces a common effect in both visual and
auditory modalities of significant frontal P3 amplitude reduction, but no
significant parietal P3 amplitude reduction. These results are consistent with
the view that there are modality-independent generators of the parietal and
frontal P3. The finding of drug-induced memory impairment and modulations of
frontal ERP deflections is also consistent with recent evidence of a significant
role for regions of the frontal lobe in encoding and retrieval of long-term
memories.
PMID- 10686372
TI - Behaviorally-evoked plasma catecholamine response and 24-hour excretion of
urinary catecholamines among cardiac and vascular reactors.
AB - Individuals differ in the cardiac and vascular processes that underlie blood
pressure elevations evoked by environmental stimuli; such differences may reflect
variability in sympathoadrenal response. We separated 108 healthy, young-adult
males into those with predominant elevations in either cardiac output or
peripheral resistance when exposed to psychological challenges. We then asked if
they differed on other measures of cardiovascular response, concomitant plasma
catecholamine reactions or 24-h urinary excretion of catecholamines. Cardiac
reactors, relative to vascular reactors, showed reduced cardiac pre-ejection
period, a smaller reduction in stroke volume, and elevated plasma epinephrine
response and 24-h urinary epinephrine excretion. Vascular reactors, relative to
cardiac reactors, responded to mental stress with more elevated diastolic blood
pressure, a rise in peripheral resistance and pulse wave velocity, and a greater
reduction in stroke volume. Vascular reactors, however, did not show plasma
norepinephrine response or 24-h urinary norepinephrine excretion that was greater
than cardiac reactors. The results provide partial support for the hypothesis
that variability in sympathoadrenal activity contributes to individual
differences in cardiac and vascular reactivity, and extend prior observations by
demonstrating covariation of behaviorally-elicited cardiac reactivity with the 24
h excretion of epinephrine.
PMID- 10686373
TI - An electrocortical comparison of executed and rejected shots in skilled marksmen.
AB - Electroencephalographic (EEG) activity during the preshot period was investigated
in seven skilled marksmen. Specifically, alpha and beta spectral power were
obtained for the 4-s period prior to the execution or rejection of shots.
Rejected shots were defined as those that resulted in the marksman's self
initiated decision to withdraw their rifle from the target rather than execute
the shot. EEG activity during the preparatory period was contrasted between the
executed and rejected shots to better understand the involved attentional
processes associated with the preshot state. Results for rejected compared with
executed shots revealed a progressive increase in alpha and beta power for
rejected compared with executed shots, which increased across the preparatory
period. Furthermore, increased spectral power was found in the left compared with
the right hemisphere for both executed and rejected shots, and in the different
regions of the scalp. Therefore, the decision to reject a shot seems to be
characterized by inappropriate allocation of the neural resources associated with
task execution.
PMID- 10686374
TI - Nonresponders among hyperhidrotics.
AB - In the context of our investigation on palmar sweating and hyperhidrosis we
subjected 40 individuals (20 hyperhidrotic and 20 normal) to noise stimulation.
The participants received ten startling auditory tones (square pulse of 400 ms
duration, 1000 Hz frequency and 105-dB intensity) at random intervals varying
from 15-55 s. Hyperhidrotic subjects, relative to controls, responded with
greater amplitude and habituated later, but a subset of these subjects failed to
respond at all to the tone. In this report, we focus on the finding that some
hyperhidrotics were nonresponders. We discuss the consequences of this finding,
both its implication for understanding hyperhidrosis and nonresponsiveness, as
well as the complexity of sympathetic nervous system activation.
PMID- 10686375
TI - One-dimensional solute transport in stratified sands at short travel distances.
AB - This paper presents laboratory-scale experimental observations on the migration
of a non-reactive pollutant, sodium chloride, through stratified sands at short
travel distances under one-dimensional flow conditions. Sand stratifications,
perpendicular, parallel and inclined to the main flow direction, were used and
contrary to most other published research work, flow was forced through the
stratifications at a constant mean pore water velocity. The paper therefore
examines the isolated effects of the different dispersion properties and particle
size distribution of the sands used on their dispersion behaviour in different
stratification configurations under the specified flow conditions. The initial
part of the work on homogeneous sands produced differences in the dispersion
which was found to be particle size distribution- and volume-dependent. For the
stratified configurations and for the same volume of soil, the results showed
different dispersion behaviour at the outflow position depending on the type of
stratification and the sequence of the sands within each stratification. The
paper presented a picture of the effect of various soils and flow conditions
imposed on the transport of the solute and provided useful data on the profile of
solute concentration for remediation purposes.
PMID- 10686376
TI - Treatment of hazardous sorbents generated from the adsorption of heavy metals
during incineration.
AB - The emission of heavy metals during waste incineration can be effectively reduced
through the practice of employing non-toxic sorbents. These sorbents can react
with toxic metals at high temperatures and create metal binding between them by
various physical and chemical mechanisms. After the adsorption process, the used
sorbents, which contain heavy metals, need to be desorbed to reduce their
potential environmental hazards or provide reusable sorbents for economical
aspect. The sorbent's adsorption efficiency is affected by different operating
conditions and waste elemental compositions during incineration, which, in turn,
affect their desorption characteristics. However, the effects of operating
condition and waste elemental composition on the stability of heavy metals in the
sorbents and the desorption efficiencies have been little studied. This study
investigates the desorption characteristics of heavy metals (Cr, Pb, Cu, and Cd)
from the hazardous sorbents with different extracting reagents (H(2)O, HCl, EDTA,
and Na(2)S(2)O(5)). The hazardous sorbents were generated under different
adsorption time and various input waste elemental compositions during
incineration process.
PMID- 10686377
TI - Effect of methanol-containing additive on the emission of carbonyl compounds from
a heavy-duty diesel engine.
AB - This study was aimed at determining the effect of methanol-containing additive
(MCA) on the emission of carbonyl compounds (CBCs) generated from the diesel
engine. For this experiment, a heavy-duty diesel engine was connected with a full
flow critical flow ventri (CFV) type dilution tunnel, a Schenck GS-350 DC
dynamometer, and a DC-IV control system in series. The operating conditions of
the heavy-duty diesel engine for both cold-start and hot-start Transient Cycle
tests and for both low-load and high-load steady-state tests were ascertained.
The exhaust of CBCs collected from a 2,4-dinitrophenylhydrazine (2,4-DNPH)-coated
cartridge were first converted to corresponding hydrazone derivatives, which were
then solvent-eluted and analyzed by a High Performance Liquid Chromatograph
(HPLC) with an ultraviolet-visible (UV) detector. When either 10% or 15% MCA was
used, the emission factors of the CBCs acrolein and isovaleraldehyde increased by
at least 91%. Accordingly, future studies must be done to cut down the emission
of CBCs when MCA and methanol alternative fuels are used.
PMID- 10686378
TI - H(2)O(2)/UV degradation kinetics of isoprene in aqueous solution.
AB - Hydrogen peroxide and UV radiation have been used in the photochemical
degradation of isoprene in aqueous solutions. A kinetic study is carried out
taking into account the contribution of the UV radiation reaction and the
combined reaction with hydrogen peroxide. An empirical reaction rate expression,
which considers the two reactions taking place in parallel, is suggested. Pseudo
first order rate constants are obtained from batch reactor data. As the molar
ratio of H(2)O(2):isoprene increases, the rate of reaction increases linearly
while the concentration of H(2)O(2) is observed to be nearly constant throughout
the reaction; suggesting that the H(2)O(2) acts as a pseudo-catalyst. Nearly
complete oxidation of isoprene is achieved. These results indicate that the
H(2)O(2)/UV process appears to be a competitive alternative destructive treatment
for removing isoprene from water present at low levels.
PMID- 10686379
TI - Comparative adsorption of metal and dye on flake- and bead-types of chitosans
prepared from fishery wastes.
AB - The adsorption capacities and rates of Cu(II) and a commercial reactive dye RR222
on flake- and bead-types of chitosans prepared from three fishery wastes (shrimp,
crab, and lobster shells) were compared at 30 degrees C. It was shown that all
equilibrium isotherms could be well fitted by the Langmuir equation. The
adsorption capacity of Cu(II) on flake- and bead-types of chitosans appeared to
be comparable, but the adsorption capacity of RR222 on bead type was much larger
than that on flake type by a factor of 2. 0-3.8. The rates of dye adsorption on
both types of chitosans indicated different controlling mechanisms. In addition,
the bead type of chitosans exhibited a greater rate compared to the flake type.
PMID- 10686380
TI - Soluble polycyclic aromatic hydrocarbons in raw coals.
AB - Polycyclic aromatic hydrocarbons (PAHs) are considered to be a group of compounds
that pose potential health hazards since some PAHs are known carcinogens. During
coal utilization processes, such as coal combustion and pyrolysis, PAHs released
may be divided into two categories according to their formation pathways. One
category is derived from complex chemical reactions and the other is from free
PAHs transferred from the original coals. PAHs released from complex chemical
reactions during combustion and pyrolysis have received considerable attention in
recent years. However, free PAHs contained in raw coals have not been seriously
considered as a source of these materials to be released during the utilization
of coal. The goal of this study was to observe the relation between the content
of PAHs in different coals and the elemental composition of the coals. In this
study, eight bituminous coals with dry, ash-free carbon values varying from 65%
to 90% were selected. Each coal was extracted with dichloromethane in a Soxhlet
extractor for 6 h. The extracts were quantitatively analyzed with a gas
chromatograph/mass spectrometer (GC-MS). More than 20 kinds of PAHs were
identified. The total amount of PAHs determined varied from 1.2 to 28.3 mg/kg
from the various coal types. The maximum total PAHs extracted was reached when
the carbon content exceeded 84% by weight.
PMID- 10686382
TI - Hypothyroidism prolongs mitotic activity in the post-natal mouse brain.
AB - Circulating T(4) and T(3) were measured during the first three post-natal weeks
in the mouse and found to increase in a triphasic manner. The first increase
occurred at post-natal day 6 and was simultaneous with a decrease in
bromodeoxyuridine incorporation in areas showing post-natal mitosis. We
investigated whether there was a causal relationship between increased thyroid
hormone levels and decreased proliferation by inducing hypothyroidism in dams and
progeny. Hypothyroidism prolonged mitotic activity in the olfactory bulb,
hippocampus, subventricular zone and the cerebellar cortex. This suggests that
the increase in T(3) at the end of the first postnatal week is implicated in
terminating progenitor proliferation in many parts of the mouse brain.
PMID- 10686383
TI - Expression of an array of photoreceptor genes in chick embryonic retinal pigment
epithelium cell cultures under the induction of neuroD.
AB - Coaxing plastic, non-neuronal cells to transdifferentiate into a particular type
of neurons might have clinical applications. Previously we reported that neuroD
induces transdifferentiation of retinal pigment epithelium (RPE) cells derived
from day-6 chick embryos into cells that resemble young photoreceptor cells.
These cells also express visinin, a gene expressed early during cone
photoreceptor differentiation. Further characterization showed that the
transdifferentiated cells express a number of photoreceptor genes, including
interphotoreceptor retinoid binding protein, the alpha-subunit of
phosphodiesterase, and opsin genes encoding rhodopsin, the red, the green, and
the blue visual pigments. Our data demonstrate that neuroD can reprogram RPE to
become photoreceptor cells with substantial differentiation, and suggest the
possibility of generating photoreceptor cells from RPE using neuroD as a
molecular trigger.
PMID- 10686384
TI - Human auditory-cortex mechanisms of preattentive sound discrimination.
AB - Intracranial event-related potentials (ERPs) were recorded in neurological
patients to infrequent higher-pitch 'deviant' tones and to frequent 'standard'
tones when they occurred, in random order in a mixed sequence of standard and
deviant tones and when they occurred in separate sequences, that is, infrequent
tones alone with intervals similar to inter-deviant intervals of the mixed
sequence and frequent tones alone with intervals similar to those between the
standard tones of the mixed sequence. When the tones were ignored, ERPs showed
three types of responses revealing three different processes involved in stimulus
discrimination in the superior temporal cortex: (1) a pitch-dependent response in
the primary auditory cortex; (2) an interstimulus-interval dependent response in
the secondary auditory cortex; and (3) a change-detection ('mismatch') response
in the auditory association cortex. When the tones were attended, ERPs to deviant
and standard tones showed differences also in the basal ganglia-thalamic circuits
and in the hippocampus, indicating their involvement in attentive processing of
auditory stimulus changes.
PMID- 10686385
TI - Effects of coupled perirhinal cortex and medial septal area, fimbria-fornix,
entorhinal cortex tetrodotoxin inactivations on passive avoidance consolidation
in the rat.
AB - In order to ascertain the rat perirhinal cortex (PC) function during early
consolidation of a passive avoidance response (PAR), and to ascertain whether
there are some functional interactions with the medial septal area (MSA), the
fimbria-fornix complex (FF) and the entorhinal cortex (EC), PC-MSA, PC-FF, and PC
EC coupled inactivations were performed immediately after the PAR acquisition
session. Anesthetized male adult Wistar rats aged 60 days were treated with
stereotaxical bilateral injections of TTX (5 ng in 0.5 microl saline) in the
appropriate sites. Retrieval testing was performed 48 h later. It was shown that
all three coupled inactivations were followed by significant PAR disruption. It
may be concluded that PC is somehow active even during the first mnemonic phase
following the acquisition session, thus better defining PC mnemonic involvement
chronology. These results may be taken as indicating that during initial
consolidation the engram is concurrently processed in more than one septal and
parahippocampal site, each of which by itself is not absolutely necessary for the
final engram formation.
PMID- 10686386
TI - Differential expression patterns of the basic helix-loop-helix transcription
factors during aging of the murine brain.
AB - In this study, we investigated the expression pattern of the basic Helix-Loop
Helix transcription factors during brain aging. We provide the first evidence
that NeuroD and ME2 are differentially expressed during brain aging. Modulation
of their expression is specific to distinct areas of the aging brain. NeuroD
expression is sustained at high levels in aging cerebellum, whereas it severely
declines in aging hippocampus. In contrast, the bHLH E-protein ME2 remains
expressed in both aged cerebellum and hippocampus, although at lower levels.
These observations support the idea that a shift in the transcriptional dynamics
controlling gene expression is associated with the progressive functional decline
observed during brain aging.
PMID- 10686387
TI - Differential expression of small heat shock protein 27 in the rat hippocampus and
septum after fimbria-fornix lesion.
AB - mRNA, Western analysis and immunohistochemistry were used to study the expression
of the small heat shock protein (HSP) 27 in the rat septum and hippocampus
following fimbria-fornix lesions, a model of neurodegeneration and regeneration.
(HSP) 27 mRNA level was increased 2.5-fold in the medial septum 3 days after
lesion and this increase persisted for 10 days. In the hippocampus, after an
initial 15-fold increase at 3 days post-injury, HSP27 mRNA returned to basal
levels 10 days after the lesion. Three and 10 days after lesion, HSP27 protein
levels were increased in the septum (4.5 and 5-fold, respectively) and
hippocampus (65 and 10-fold, respectively). The morphology of the HSP27 positive
cells was indistinguishable from that of GFAP-immunoreactive cells. In addition,
in the septum of injured rats, occasional neurons were heavily labelled with anti
HSP27 antibodies. Thus, up-regulation of HSP27, particularly in glial cells, may
be a component of glial input in the processes on degeneration/regeneration which
occur in this model.
PMID- 10686388
TI - Differences between cerebral and cerebellar autoregulation during progressive
hypotension in rats.
AB - Autoregulation in the brain is essential to the maintenance of perfusion and
hence to the normal functioning of the organism in the face of various
hemodynamic challenges. The existence of prodromal symptoms preceding fainting
suggests that cerebellar autoregulation could be altered earlier than cerebral
autoregulation during the development of hypotension. The purpose of this study
was to compare cerebral and cerebellar autoregulatory responses to hypotension
induced by two rates of hemorrhage 1.5 and 2.0 ml/min. Cortical blood flows were
measured simultaneously using laser Doppler flowmetry in rats. With increasing
rate of hemorrhage, the kinetics of autoregulation were maintained in the
cerebrum, whereas it caused a progressive loss in the efficacy of autoregulation
in the cerebellum.
PMID- 10686389
TI - Inhibition of K(+)-evoked glutamate release from rat neocortical and hippocampal
slices by gabapentin.
AB - Gabapentin (Neurontin((R))) has preclinical and clinical efficacy as an
anticonvulsant, antihyperalgesic, anxiolytic, and neuroprotective drug. Since L
glutamic acid (GLU) is involved in various CNS (central nervous system)
disorders, gabapentin may attenuate the release of this neurotransmitter possibly
by interacting with the auxiliary alpha(2)delta subunit of voltage-sensitive
calcium channels (VSCC). The effects of gabapentin, pregabalin (S-(+)-3
isobutylgaba) and its enantiomer R-(-)-3-isobutylgaba, and N- and P/Q-type VSCC
targeting peptide ligands (omega-conotoxin MVIIA, omega-conotoxin MVIIC, omega
agatoxin TK) were assessed in vitro on K(+)-evoked (endogenous) GLU release from
rat neocortical and hippocampal slices. Gabapentin and pregabalin decreased GLU
release by 11-26% with R-(-)-3-isobutylgaba being less effective than pregabalin.
The reference N- and P/Q-type VSCC-targeting ligands reduced GLU release by 19
55% to implicate these VSCC in this Ca(2+)-dependent process. The inhibitory
effect of gabapentin and related compounds on GLU release may reflect a subtle
modulation of VSCC function which normalizes pathological changes in
neurotransmitter release.
PMID- 10686390
TI - Connections between retrotrapezoid nucleus and nucleus tractus solitarii in cat.
AB - The retrotrapezoid nucleus (RTN), a part of the rostral ventrolateral medulla, is
involved in the control of breathing. The mechanisms by which the RTN modulate
the activity of respiratory neurons during chemoreceptor stimulation are not
fully understood. This electrophysiological study performed in the cat
demonstrates that 18 out of 22 RTN neurons receive inputs from the commissural
subnucleus of the solitary tract (cNTS), the peripheral chemoreceptor afferents
projection site. Moreover, six RTN neurons are found to present interconnection
between RTN and the ventrolateral subnucleus of the solitary tract, an area
containing mainly bulbo-spinal respiratory neurons. The present data suggest that
RTN play a key role by concomitantly integrating chemosensitive informations
relayed by the cNTS and providing an influence on the respiratory network.
PMID- 10686391
TI - Serotonin-immunoreactive axons in the cell column of sympathetic preganglionic
neurons in the spinal cord of the filefish Stephanolepis cirrhifer.
AB - Serotonin-immunoreactive axonal components were observed in the central autonomic
nucleus (CAN), a cell column of sympathetic preganglionic neurons in the rostral
spinal cord of the filefish Stephanolepis cirrhifer. Serotonin-positive axonal
varicosities were seen around neuronal perikarya through the whole rostrocaudal
extent of the CAN, although their distribution pattern in the rostral CAN was
different from that in the caudal CAN. Electron microscopically, serotonin
positive axonal varicosities were found to make axodendritic and axosomatic
synapses on CAN neurons. Many serotonin-positive neuronal cell bodies were seen
in the raphe nuclei in the lower brainstem, whereas only a few were found in the
spinal cord. Thus most of serotoninergic axons within the CAN were considered to
originate from the raphe nuclei in the lower brainstem.
PMID- 10686392
TI - Three-year follow-up of cerebrospinal fluid tau, beta-amyloid 42 and 40
concentrations in Alzheimer's disease.
AB - Earlier studies have shown elevated levels of tau protein and decreased levels of
amyloid beta42 in cerebrospinal fluid (CSF) from patients with Alzheimer's
disease (AD). We investigated the concentrations of Abeta42, Abeta40 and tau in
CSF from AD patients on the baseline and after follow-up period of 3 years using
ELISA assays. There was a significant decrease of Abeta42 (P<0.05) and Abeta40
(P<0.05) levels with time. AD patients with the duration of the disease 2 years
or less at baseline had more pronounced decrease of Abeta42 concentrations
compared to those with the duration of the disease more than 2 years at baseline
(P<0.05). CSF tau protein concentrations increased in 9/17 but decreased in 8/17
patients. These results suggest that Abeta42 and Abeta40 may be useful in
monitoring the long-term progression of AD particularly in the early stages of
the disease.
PMID- 10686393
TI - Transmitter profile and spinal inputs of pelvic ganglion cells projecting with
preganglionic axons along the hypogastric and pelvic nerves of the male rat.
AB - Pelvic autonomic ganglion cells receive spinal preganglionic inputs via the
hypogastric (lumbar) or pelvic (sacral) nerves. Damage to these nerves stimulates
axogenesis (sprouting) from pelvic ganglion cells and two possible triggers are
deafferentation (decentralisation) or, if some ganglion cells project centrally
in these nerves, axotomy. We have used a combination of retrograde tracing and
immunohistochemistry in male rats to identify the number of pelvic ganglion cells
that project centrally along these nerves, their transmitter type and the spinal
level of their preganglionic inputs. Only a small number (<1%) of pelvic ganglion
cells project along these nerves; 29-65 project in each hypogastric nerve and 41
71 in each pelvic nerve. These neurons comprise of both cholinergic and
noradrenergic classes and the majority receive preganglionic inputs from the
nerve in which they also project. These results suggest that damage of the
hypogastric and pelvic nerves close to the pelvic ganglion is unlikely to cause
axotomy of many pelvic ganglion cells. Therefore deafferentation rather than
axotomy is likely to be the primary trigger of axogenesis occurring in pelvic
ganglia after these lesions.
PMID- 10686394
TI - Gating of segmental and transcortical reflexes to human hand muscles depends on
the mode of innervation.
AB - We investigated the influence of the innervation pattern on the transmission of
reflexes to a hand muscle. Reflexes were elicited by repetitive median nerve
stimulation and recorded from the abductor pollicis brevis muscle. Both H and
long loop reflexes were exclusively attenuated by irregular isotonic thumb
abduction. In 10 of 15 experiments the long loop reflex was blocked completely.
Inhibition intercalated between the H and long loop reflexes also decreased
considerably. The observed attenuation of both spinal and supraspinal reflexes is
suspected to take place mainly at the spinal level. Among the possible
mechanisms, reciprocal inhibition is the most likely.
PMID- 10686395
TI - Heparin specifically inhibits binding of apolipoprotein E to amyloid beta
peptide.
AB - Apolipoprotein E (apoE) binds to non-fibrillar amyloid beta-peptide with high
affinity. We find here that heparin specifically inhibits apoE-amyloid beta
peptide (1-40) interaction. Low molecular weight heparins reduce the affinity of
this interaction 3-fold as it was estimated by surface plasmon resonance. The
binding is not affected by high salt concentration, which prevents heparin
induced changes of apoE conformation. We propose that rigid protein conformation,
induced by high affinity heparin binding to apoE, is unfavorable for its
interaction to amyloid beta-peptide. Using thioflavin T assay, we find that
heparin promotes fibrillogenesis of amyloid beta-peptide whereas apoE abolishes
this effect. The data suggests that the relationship between apoE and
glycosaminoglycans may be important for amyloid beta-peptide fibril formation.
PMID- 10686396
TI - Modulation of [(35)S]GTPgammaS binding to chinese hamster ovary cell membranes by
D(2(short)) dopamine receptors.
AB - Rat dopamine D(2short) expressed in Chinese hamster ovary (CHO) cells were
characterized by means of activation of [(35)S]-guanosine 5'-O-(gamma
thiotriphosphate) ([(35)S]GTPgammaS) binding and inhibition of [(3)H]raclopride
binding. Among 18 dopaminergic ligands studied dopamine, NPA, apomorphine and
quinpirole were full agonists in activation of [(35)S]GTPgammaS binding, while
seven ligands were partial agonists with efficacies from 16 to 69% of the effect
of dopamine and seven ligands were antagonists having no effect on the basal
level of [(35)S]GTPgammaS binding, but inhibited dopamine-dependent activation in
a dose-response manner. Despite the different efficacies, the potencies of all 18
ligands to modulate [(35)S]GTPgammaS binding revealed a good correlation with
their potencies to inhibit [(3)H]raclopride binding in the CHO cell membranes.
This indicates that the binding of the ligand to the receptor determines its
potency, but has no direct correlation with its intrinsic activity.
PMID- 10686397
TI - Expression of interleukin-6 in human dorsal root ganglion cells.
AB - The expression of Interleukin-6 (IL-6) was studied in normal dorsal root ganglia
(DRG) of juvenile and foetal humans, using immunohistochemistry and in situ
hybridization techniques. There was an expression of IL-6-like immunoreactivity
in more than 75% out of neuronal cells in the juvenile ganglia with a peripheral
localization, and also an expression in the foetal ganglion cells. There was a co
localization of IL-6 with substance P (SP) and calcitonin gene-related peptide
(CGRP) in more than 60% of the DRG cells, respectively. By in situ hybridization
0.9% of the cells in the juvenile ganglia and 1.1% of the cells in the foetal
ganglia showed a positive signal for IL-6. In addition, expression of IL-6 was
found in juvenile medulla spinalis, preferentially in the white matter.
PMID- 10686398
TI - Gate for photic resetting of intrinsic rhythmicity of the rat suprachiasmatic
nucleus under a long photoperiod.
AB - In rats maintained under a long photoperiod and then released into darkness, the
time interval enabling photic resetting of the intrinsic rhythmicity of the
suprachiasmatic nucleus (SCN), namely of the rhythm in the light-induced c-Fos
production, was similar to the previously reported time interval enabling high c
fos photoinduction in the SCN (Sumova, A., Travnickova, Z., Peters, R., Schwartz,
W.J. and Illnerova, H., The rat suprachiasmatic nucleus is a clock for all
seasons. Proc. Natl. Acad. Sci. USA, 92 (1995) 7754-7758). The data indicate that
both intervals may represent the same window for the photic sensitivity of the
SCN pacemaking program.
PMID- 10686399
TI - Immunohistochemical detection of vascular endothelial growth factor (VEGF) and
VEGF-receptors Flt-1 and KDR/Flk-1 in the vestibule of guinea pigs.
AB - Vascular endothelial growth factor (VEGF), known as an endothelial cell-specific
mitogen, has been reported to be linked also to the NO/cGMP-pathway, which has
been notified in the inner ear. Up to now, VEGF has not yet been described in the
inner ear. We performed immunohistochemical analysis using specific antibodies to
VEGF and to both known VEGF-receptors Flt-1 and KDR/Flk-1 on paraffin-sections of
temporal bones from guinea pigs (n=5). Immunoreactivity of VEGF, Flt-1 and
KDR/Flk-1 was detectable in a subpopulation of vestibular ganglion cells. VEGF
could be found also in the endothelium of blood vessels, in fibrocytes of the
lamina propria and in the neuroepithelium. Strong immuno-labelling to Flt-1 was
evident in nerve fibres, vascular endothelium and in the neuroepithelium.
Fibrocytes, endothelium of blood vessels, supporting cells and calyces in the
sensory epithelium revealed immunoreactivity to KDR/Flk-1. These findings give
evidence that VEGF, Flt-1 and KDR/Flk-1 are constitutively expressed in the
vestibule.
PMID- 10686400
TI - Subunit-dependent inhibition of recombinant rodent N-methyl-D-aspartate receptors
by a HIV-1 glycoprotein 120 derived peptide.
AB - Considerable evidence suggests that low (picomolar) concentrations of the HIV-1
envelope glycoprotein gp120 induce neuronal cell death by stimulating the release
of microglial toxins, which in turn activate N-methyl-D-aspartate (NMDA)
receptors. Conversely, high (micromolar) concentrations of gp120 have been
reported to directly inhibit NMDA receptor-mediated currents and do not induce
neurotoxicity. Here we show that micromolar concentrations of a synthetic peptide
corresponding to the V3-loop of gp120 (V3-pep) inhibited agonist responses of
recombinant heteromeric rodent NMDA receptors expressed in Xenopus laevis oocytes
by decreasing their apparent glycine affinity. Different combinations of NMDA
receptor subunits displayed differential sensitivities to inhibition by V3-pep,
with a potency rank order of NR1/2B > NR1/2D > NR1/2C > or = NR1/2A. Our
observations may provide an explanation for the reduced neurotoxicity of high
doses of gp120 in cell cultures and may be useful for the pharmacological
discrimination of NMDA receptor subtypes.
PMID- 10686401
TI - Effects of morphine glucuronides on the function of opioid receptors in human SK
N-SH cells.
AB - Morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) are active
metabolites of morphine. The effects of M3G and M6G on the opioid receptor
transduction system has not yet been fully elucidated. Formation of cAMP after
treatment with various doses of morphine, M3G, and M6G was studied. M6G and
morphine, but not M3G, showed a dose dependent inhibition of cAMP accumulation.
Naloxone blocked the inhibitory effect of M6G, M3G, and morphine. Pretreatment
with M3G did not change the effects of morphine and M6G. The G-protein inhibitor
PTX, prevented morphine, M3G, and M6G effects on cAMP. M3G and M6G vary in their
ability to interact with the opioid receptor effector system. Inhibition of cAMP
evoked by activation of opioid receptors and inhibitory G-proteins may play a
role in the actions of M6G and M3G.
PMID- 10686402
TI - Potassium currents in CA1 neurons of rat hippocampus increase shortly after
transient cerebral ischemia.
AB - Total potassium current in CA1 pyramidal neurons was studied using whole-cell
voltage-clamp recording technique in hippocampal slices prepared before and at 6
8 h after transient forebrain ischemia. The total potassium current significantly
increased from a control value of 2.17+/-0.17 to 2.96+/-0.31 nA (measured at +70
mV, P<0.05) after ischemia. The slope factor V(c) of activation curve
significantly decreased and the half-inactivation voltage V(h) shifted to more
depolarized potentials after ischemia. These results indicate that the increase
of potassium current might be responsible for the decreased excitability in CA1
neurons after severe ischemia and may be involved in postischemic cell death in
hippocampus.
PMID- 10686403
TI - Correlation between behavior and extracellular dopamine levels in rat striatum:
comparison of microdialysis and fast-scan cyclic voltammetry.
AB - Recently, fast-scan cyclic voltammetry (FSCV) has been adapted for real-time
measurements of evoked dopamine (DA) release and uptake in freely moving rats.
Using the advantages of this experimental design in combination with behavioral
measures, we examined the effect of GBR 12909 (20 mg/kg, i.p.), a selective DA
uptake inhibitor, on striatal extracellular DA dynamics and compared these data
to that obtained by microdialysis. These studies established that both techniques
report changes in DA that correlate with the kinetics of GBR 12909-induced
behavioral effects. However, the time course of changes in evoked DA levels
detected by FSCV was more closely linked with the changes in stereotypy than
microdialysis measurements.
PMID- 10686404
TI - Expression of insulin-like growth factor-I in rat glioma cells is associated with
change in both immunogenicity and apoptosis.
AB - Insulin-like growth factor I (IGF-I), has a role in cellular differentiation and
is also expressed in neoplastic transformation of glioma cells. We recently
demonstrated inhibition in expression of cellular IGF-I after transfection with
vectors that incodes a segment of the human IGF-I RNA in antisense orientation.
The transfected cells expressed increased levels of both MHC-I and B7 molecules.
In this paper we show that IGF-I antisense transfected cells also become
apoptotic. Moreover, the phenomenon of programmed cell death is related to the
phenomenon that results in increased expression of MHC-I and B7 molecules. Co
transfection of rat glioma cells with the vector expressing IGF-I antisense RNA
and with vectors encoding the expression of MHC-I and B7 antisense cDNA
suppressed the expression of both of these molecules and was associated with a
decrease in apoptosis.
PMID- 10686405
TI - Amphetamine-induced zif268 mRNA expression in the medial posterior nucleus
accumbens in cholecystokinin-A receptor mutant rats.
AB - Converging evidence supports a role for cholecystokinin (CCK) in modulating
dopamine (DA)-mediated activity in the rat mesolimbic system. In particular, CCK
co-localized with mesolimbic DA cells originating in the ventral tegmental area
potentiates DA function in the medial posterior nucleus accumbens (mpNA) through
CCK-A receptors. Recently, a strain of rats lacking the CCK-A receptor, Otsuka
Long Evans Tokushima Fatty (OLETF), has been discovered making it possible to
study the mesolimbic DA regulatory role of CCK-A receptors. Previous studies have
shown that OLETF rats are less sensitive to amphetamine (AMPH)-induced behavioral
effects compared to controls. To determine if this altered sensitivity is
associated with decreased AMPH-induced postsynaptic activation in the mpNA in
OLETF rats, we performed the following experiment. OLETF (CCK-A mutants) and Long
Evans Tokushima Otsuka (LETO) rats (controls) were given subcutaneous injections
of either saline or AMPH (5.0 mg/kg). One hour after injection all animals were
sacrificed and activation of the mpNA was assessed using in situ hybridization
with antisense probes for zif268 mRNA. AMPH treatment produced a significant up
regulation of zif268 mRNA expression in both OLETF and LETO rats (P=0.0002),
compared to saline treatment. However, AMPH had almost an identical effect on
zif268 mRNA expression in the mpNA in both rat strains suggesting similar
postsynaptic neural activation. The significance of this AMPH-induced zif268 mRNA
expression in these two rat strains and its relationship to CCK function in the
nucleus accumbens are discussed.
PMID- 10686406
TI - Increased vasomotor sympathetic nerve activity and decreased plasma nitric oxide
release after head-down bed rest in humans: disappearance of correlation between
vasoconstrictor and vasodilator.
AB - We hypothesized that the relationship between resting levels of sympathetic
vasoconstrictor nerve traffic and dilator substance nitric oxide (NO) release is
altered after exposure to microgravity, resulting in abnormal peripheral
resistance. To examine the hypothesis, we assessed muscle sympathetic nerve
activity (MSNA) (microneurography), an indicator of NO release (plasma
nitrite/nitrate concentrations) and leg vascular resistance (venous occlusion
plethysmography) in 20 healthy male volunteers before and after 14 days of 6
degrees head-down bed rest (HDBR), the ground-based analogue of microgravity.
MSNA increased, while plasma nitrite/nitrate concentrations decreased after HDBR.
A significant positive correlation observed between MSNA and plasma
nitrite/nitrate concentrations before HDBR disappeared after HDBR. Leg vascular
resistance increased after HDBR. In conclusion, an imbalance between sympathetic
vasoconstrictor traffic and NO release might contribute to elevated peripheral
vascular resistance following HDBR.
PMID- 10686407
TI - Absence of the GluR2 receptor sensitizes mouse sympathetic neurons to nerve
growth factor deprivation.
AB - Over-activation of glutamate receptors is implicated in neurodegeneration. Using
mice with a deletion in the GluR2 gene, we studied the sensitivity of sympathetic
neurons to reduced levels of nerve growth factor (NGF), which can cause neuronal
cell death. Under standard culture conditions of 50 ng/ml NGF, neurons from the
superior cervical ganglion survived and grew equally well compared with wild type
controls. However, the subsequent reduction of NGF levels caused significantly
poorer survival among mutant neurons by 48 h, at 44+/-13% of control at 10 ng/ml
NGF, and dropping further to 14+/-6% at 0.05 ng/ml NGF. These results suggest
that the absence of GluR2 impairs the ability of these NGF-sensitive neurons to
survive under limiting amounts of this neurotrophic factor.
PMID- 10686408
TI - Gonadectomy and persistent pain differently affect hippocampal c-Fos expression
in male and female rats.
AB - Hippocampal c-Fos expression was studied in male and female rats after
gonadectomy and persistent pain. Three weeks after surgery, animals were sham- or
formalin-injected (50 microl, 10%) and placed in a familiar testing apparatus.
The formalin-evoked licking, flexing and jerking of the injected paw were
recorded for 60 min, c-Fos was determined in the dorsal and ventral hippocampus:
dentate gyrus (DG), CA1 and CA3. Gonadectomy induced higher c-Fos in the dorsal
DG of both sexes, in all ventral subfields of males and in the ventral CA3 of
females. In normal males and females, formalin increased c-Fos in the dorsal DG
and in the male ventral subfields. In gonadectomized ones formalin decreased or
did not change c-Fos. Gonadectomy induced longer flexing in males and females.
These data indicate an important and sex-dependent interaction between gonadal
hormones, nociceptive input and neuronal activity in the hippocampus.
PMID- 10686409
TI - Hyperpolarization-activated cation currents in stellate and pyramidal neurons of
rat entorhinal cortex.
AB - Properties of hyperpolarization-activated cation currents (I(h)) were
investigated in neurons of juvenile rat entorhinal cortex using the patch-clamp
technique. A rat brain slice preparation containing the entorhinal cortex was
used for whole-cell recordings of I(h) in pyramidal cells from layer IV and in
stellate cells from layer II of the entorhinal cortex. In both stellate and
pyramidal cells, I(h) activated at potentials more negative than -60 mV and did
not show any time-dependent inactivation. Half-maximal activation of I(h) was
achieved at -95.3 mV in pyramidal cells and at -95.0 mV in stellate cells. The
channels were permeable for sodium and potassium ions. I(h) of pyramidal and
stellate neurons was reduced by about 50% in the presence of 100 microM ZD7288.
Extracellularly applied 1 mM Cs(+) decreased I(h) of pyramidal cells by 92%,
whereas I(h) of stellate cells was only reduced by 70%. In both pyramidal and
stellate neurons, I(h) was not significantly changed during the application of 1
mM Ba(2+). 8-Bromo-c-AMP increased amplitudes of I(h) in stellate cells, while
I(h) of pyramidal cells remained unchanged. It is suggested that different types
of hyperpolarization-activated cation channels are expressed in pyramidal and
stellate cells of the entorhinal cortex.
PMID- 10686410
TI - Regional and cellular distribution of bleomycin hydrolase mRNA in human brain:
comparison between Alzheimer's diseased and control brains.
AB - Genetic polymorphism of human bleomycin hydrolase (hBH) has been reported to be
associated with the risk of sporadic Alzheimer's disease (AD). The regional and
cellular distribution of mRNA encoding hBH in the brain from controls and
patients with AD was examined using in situ hybridization. A hybridization
signal, in the form of clusters of single cells, was observed in the white
matter. Our results indicate a predominantly astrocytic expression of hBH in the
investigated human brain regions. Although the signal intensity was generally
reduced in AD brains, the large variability among controls rendered this trend
statistically insignificant.
PMID- 10686411
TI - Alterations with age of the neurons expressing P(0) in the rat spinal cord.
AB - In mammals, P(0) expression is thought to be restricted to the peripheral nervous
system (PNS), whereas in some other vertebrates it is expressed not only in the
PNS but also in the central nervous system (CNS). Previously we reported that
P(0) is expressed in the rat spinal cord and that its glycosylation state changes
with age. In this report, we determine, by immunohistochemical and
immunocytochemical analyses, that the neurons in the spinal cord express P(0).
Furthermore, our data show that the number of neurons expressing P(0) decreases
and their sizes become smaller with age. Thus, the results emphasize the
importance of neurons expressing P(0) in the spinal cord in the formation and
maintenance of the neural network.
PMID- 10686412
TI - Immunocytochemical and ultrastructural study of the motor cortex in patients with
lower motor neuron disease.
AB - This report conveys the results of an immunocytochemical and ultrastructural
study of the motor cortices of six patients with clinically and pathologically
diagnosed lower motor neuron disease (LMND) such as progressive spinal muscular
atrophy, progressive bulbar palsy, or both. These patients showed neither upper
motor neuron signs nor upper motor neuron system involvement including the
corticospinal tract in postmortem tissues after conventional stainings. Specimens
from 12 age-matched normal individuals served as controls. All patients showed
loss of brainstem motor neurons and anterior horn cells. Betz cells in LMND
patients were significantly reduced in number as compared to controls (P<0.01).
However, there was no significant difference in the density of phosphorylated
neurofilament (PNF) (200 kDa)-positive Betz cells between LMND patients and
controls. The pyramidal cells of layer III were immunostained for PNF in four of
six LMND patients, but there was no significant difference in the density of PNF
positive pyramidal cells between LMND patients and controls. The number of
astrocytes immunostained for glial fibrillary acidic protein increased in layer
III and at the transition between white matter and motor cortex in three out of
six patients and one of 12 controls. Ultrastructural examination revealed that
the Betz cells of five of six LMND patients had Bunina bodies, Lewy body-like
inclusions or skein-like inclusions, all of which are characteristic of
amyotrophic lateral sclerosis (ALS). These findings suggest that most patients
with clinically and pathologically-diagnosed LMND should be classified into the
category of ALS.
PMID- 10686413
TI - Transient induction of neuronal nitric oxide synthase in neurons of rat cerebral
cortex after status epilepticus.
AB - The change in neuronal nitric oxide synthase (nNOS) expression after status
epilepticus induced by kainate was examined in the rat cerebral cortex.
Expressional change was assessed using nNOS immunohistochemistry and reverse
transcription-polymerase chain reaction for nNOS mRNA. Constitutive nNOS-positive
neurons was observed in the cerebral cortex of the control group. At 1 and 3 days
after status epilepticus, nNOS-positive neurons were present in a deep layer of
various cortical regions such as primary motor cortex, secondary motor cortex,
primary somatosensory cortex, secondary somatosensory cortex, parietal
association cortex, insular cortex, ectorhinal cortex, temporal association
cortex, auditory cortex and visual cortex. The level of nNOS mRNA increased at 1,
3, 6 and 12 days after status epilepticus compared to controls. This report
provides the first morphological evidence that nNOS are induced in neurons of the
cerebral cortex following seizure.
PMID- 10686414
TI - Pointing to a target from an upright position in human: tuning of postural
responses when there is target uncertainty.
AB - Human subjects performed, from a standing position, rapid hand pointings to
visual targets located within or beyond the prehension space. To examine the
interaction between posture and the goal-directed movement we introduced a visual
double-step perturbation requiring a reprogramming of the hand movement. Trials
directed towards the same spatial goal but differentiated only by the likeliness
of a visual double-step were compared. The hand kinematics was not affected by
the uncertainty of the visual perturbation; an increased trunk bending, however,
was observed. This suggests that uncertainty constraints are integrated in a
predictive manner for the optimal coordination of the hand and postural control
systems.
PMID- 10686415
TI - Testosterone and estrogen affect neuronal differentiation but not proliferation
in early embryonic cortex of the rat: the possible roles of androgen and estrogen
receptors.
AB - We examined the effect of testosterone (T) and 17 beta-estradiol (E) on
differentiation and proliferation of cultured neurons from the cortex of 14-day
rat embryos (E14) using immunocytochemistry. We found that the cultures receiving
E had significantly more neurons with longer neurites than the control cultures,
while both fewer and less differentiated neurons were seen after 24 h of
incubation with T. However, neither T nor E changed the number of cells positive
for BrdU, a proliferation marker. We also found that the androgen receptor (AR)
was markedly expressed in the neurons, whereas the expression of estrogen
(ER(alpha)) receptor was barely detectable. These results suggest that E and T
differ in effect on differentiation, while neither affect proliferation in early
developmental cortex. Furthermore, since the AR is expressed in the cortical
neurons by E14, the inhibitory effect of T on differentiation may be receptor
mediated, while the stimulatory effects of estrogen in the cortex do not appear
to involve nuclear ER(alpha) at this developmental stage.
PMID- 10686416
TI - Systemic lipopolysaccharide and interleukin-1beta activate the interleukin 6:
STAT intracellular signaling pathway in neurons of mouse trigeminal ganglion.
AB - We have studied the activation of signal transducers and activators of
transcription (STATs) in trigeminal ganglion after intraperitoneal injection of
lipopolysaccharide (LPS) and Interleukin-1beta (IL-1beta). Using electrophoretic
mobility shift assays we have shown that STAT1 and STAT3 are activated within 1
to 2 h. of injection of either LPS or IL-1beta. Eight hours after LPS injection
the DNA binding activity of these complexes is still elevated while induction by
IL-1beta returns to baseline levels within 4 h. By immunohistochemistry, using an
antibody specific for the tyrosine phosphorylated, activated form of STAT-1, we
show that this induction occurs in sensory neurons. IL-6 may be important in this
cascade since induction of STATs by IL-1beta is blocked in Interleukin-6 knock
out mice.
PMID- 10686417
TI - An immunocytochemical study of mitochondrial manganese-superoxide dismutase in
the rat hippocampus after kainate administration.
AB - We examined the immunocytochemical distribution of mitochondrial Mn-superoxide
dismutase (SOD-2) in the rat hippocampus after systemic injection of kainic acid
(KA), in order to understand SOD-2-responsible antioxidant defense mechanism
during the neurodegenerative process. SOD-2 immunostaining was more intense in
CA3 pyramidal neurons than in CA1 neurons in the normal hippocampus. The
immunoreactivity in region CA1 was reduced without significant neuronal losses
within 12 h of KA injection. The CA1 and CA3 neurons lost their immunoreactivity,
whereas SOD-2-positive glia-like cells proliferated, mainly throughout the CA1
sector, and had intense immunoreactivity 3 and 7 days after KA injection. This
immunocytochemical distribution of SOD-2-positive non-neuronal elements was
similar to that of glial fibrillary acidic protein (GFAP) and S-100 protein
positive cells. Activated microglial cells selectively marked with lectin
occurred in the areas affected by the KA-induced lesion. Double-labeling
immunocytochemistry showed the co-localization of SOD-2-positive non-neuronal
cells and GFAP or S-100 protein-like immunoreactivity in the same cells. This
suggests that astroglial cells mobilized to synthesize of SOD-2 protein in a
response to KA toxicity designed to reduce the oxidative damage.
PMID- 10686418
TI - Are there proliferating neuronal precursors in adult rat dorsal root ganglia?
AB - The origin of new neurons in dorsal root ganglia of adult rat was investigated
using an experimental model in which postnatal neurogenesis naturally occurring
is enhanced and restricted in a brief period of life. Possible mitotic origin of
new neurons was investigated by means of 5-bromo-2-deoxyuridine, anti-NF 200
antibody was used to detect if proliferated cells showed a neuronal phenotype.
The results suggest that postnatal neurogenesis in dorsal root ganglia could
depend only in part on precursor proliferation and that normally new neurons
derive from the late differentiation of postmitotic cells.
PMID- 10686419
TI - Overexpression of neurofilament subunit NF-L and NF-H extends survival of a mouse
model for amyotrophic lateral sclerosis.
AB - Mutations in superoxide dismutase 1 (SOD1) cause amyotrophic lateral sclerosis
(ALS) in a subset of patients. Neurofilaments (NFs), the most abundant protein in
motoneurons, may play a role in motoneuron degeneration. To investigate this
role, we crossed transgenic mice expressing SOD1 mutant G93A (G93A mice) with
mice overexpressing mouse neurofilament subunit H (H mice) or L (L mice). G93A
mice overexpressing either NF-L or NF-H developed ALS later and survived longer
than the G93A mice on a wild type background. These results illustrate a
beneficial role of neurofilaments in ALS and call into question of several
hypotheses regarding the role of neurofilaments in the development of ALS.
PMID- 10686420
TI - Nonsense mutations in the COL1A1 gene preferentially reduce nuclear levels of
mRNA but not hnRNA in osteogenesis imperfecta type I cell strains.
AB - Osteogenesis imperfecta (OI) is a heterogeneous disorder of type I collagen
resulting in varying degrees of severity. The mildest form of OI (Type I) is
associated with bone fragility, normal or near normal stature and blue sclerae.
All forms of OI are the result of mutations in COL1A1 or COL1A2, the genes that
encode the proalpha1(I) and proalpha2(I) chains of type I collagen, respectively.
Mutations identified in patients with OI type I lead to premature termination
codons and allele-specific reductions of nuclear mRNA (termed nonsense-mediated
mRNA decay or NMD), resulting in a COL1A1 null allele. In mammals, this process
primarily effects RNA that co-purifies with the nuclear fraction of the cell.
Using a semi-quantitative RT-PCR assay, we compare the relative amounts of normal
and mutant transcripts in unprocessed hnRNA and mature mRNA isolated from the
nuclear fraction of cells from 11 OI type I individuals with previously
identified mutations distributed throughout the COL1A1 gene. While we detect
about equal amounts of normal and mutant hnRNA from each cell strain, there is
preferential reduction in the relative amount of mutant mRNA when compared to
normal; only the cell strain with a mutation in the last exon escapes the major
effects of NMD. Our data indicate that NMD targets mRNA rather than hnRNA for
degradation, and that this occurs either during or after splicing but prior to
cytoplasmic translation.
PMID- 10686421
TI - Immediate cell signal induced by laminin in rat sertoli cells.
AB - Rat Sertoli cells in primary culture have been studied for their ability to
respond to extracellular matrix macromolecules by increases of [Ca(2+)](i). We
observed that cells seeded on glass coverslips, loaded with the intracellular
Ca(2+) indicator fura-2, responded to laminin, but not to fibronectin, with an
immediate [Ca(2+)](i) raise, with a peak followed by a prolonged plateau.
[Ca(2+)](i) increases were dependent upon Ca(2+) influx across the plasma
membrane and Ca(2+) release from intracellular Ca(2+) pools. Ca(2+) influx was
inhibited by extracellular Ca(2+) removal by EGTA, and by treatment with La(3+),
or with the L-type voltage operated Ca(2+) channel blocker, nifedipine. Ca(2+)
release from intracellular Ca(2+) storing organelles, was inhibited by the
microsomal Ca(2+)-ATPase blocker thapsigargin. Responses were mimicked by
synthetic peptides carrying the Arg-Gly-Asp adhesion sequence, but not by the
control Arg-Gly-Glu-containing peptide, in which aspartic acid was replaced by
glutamic acid. Laminin-dependent [Ca(2+)](i) increases were down-regulated by the
follicle-stimulating hormone. However, this occurred only when cells were not
subjected to homotypic cell-cell contact, and responded to the hormone with a
significant [Ca(2+)](i) elevation. These results indicate that laminin may
regulate Sertoli cells by intracellular signals that perturb Ca(2+) homeostasis.
This role may be related to an effect exerted by the seminiferous epithelium
basement membrane on the regulation of spermatogenesis.
PMID- 10686422
TI - The alpha1(VIII) and alpha2(VIII) collagen chains form two distinct homotrimeric
proteins in vivo.
AB - The short chain collagen variant, type VIII, is considered to be comprised of two
distinct gene products, the alpha1 and alpha2 polypeptide chains. However, recent
in vitro translation studies suggest that these chains can form homotrimers. We
report here data from biochemical, immunohistochemical and molecular biological
experiments, which together provide evidence that alpha1 and alpha2 polypeptides
of type VIII collagen exist as homotrimers in cells and tissues. High-performance
liquid chromatographic separation of type VIII collagen isolated from Descemet's
membrane consistently demonstrated equimolar quantities of the two chains
(alpha1:alpha2 1. 03+/-0.02 (S.E.M.); n=41). The availability of highly specific
antibodies for the two polypeptides has assisted the in vivo characterisation of
type VIII collagen. Immunoprecipitation of trimeric type VIII collagen from
Descemet's membrane with purified anti-alpha1(VIII) and anti-alpha2(VIII) yielded
fractions that contained only the alpha1(VIII) and alpha2(VIII) chains,
respectively. Cultured human mesangial cells synthesised both polypeptides, but
the alpha1(VIII) chain was found exclusively in the cell pellet, while the media
contained only the alpha2(VIII) chain. The RNA from human mesangial cells and
cornea showed message for both chains. However, in peritoneal fibroblast and
mesothelial cell RNA, only alpha1(VIII) mRNA was detectable, demonstrating that
the transcription of these two genes was not always co-ordinated.
Immunohistochemistry showed that both polypeptides were present in cornea, optic
nerve, aorta and umbilical cord but did not always co-localise. These results
indicate the alpha1(VIII) and alpha2(VIII) chains preferentially form pepsin
resistant, homotrimeric molecules and so can exist as two distinct proteins.
PMID- 10686423
TI - Accumulation of properly folded human type III procollagen molecules in specific
intracellular membranous compartments in the yeast Pichia pastoris.
AB - It was recently reported that co-expression of the proalpha1(III) chain of human
type III procollagen with the subunits of human prolyl 4-hydroxylase in Pichia
pastoris produces fully hydroxylated and properly folded recombinant type III
procollagen molecules (Vuorela, A., Myllyharju, J., Nissi, R., Pihlajaniemi, T.,
Kivirikko, K.I., 1997. Assembly of human prolyl 4-hydroxylase and type III
collagen in the yeast Pichia pastoris: formation of a stable enzyme tetramer
requires coexpression with collagen and assembly of a stable collagen requires
coexpression with prolyl 4-hydroxylase. EMBO J. 16, 6702-6712). These properly
folded molecules accumulated inside the yeast cell, however, only approximately
10% were found in the culture medium. We report here that replacement of the
authentic signal sequence of the human proalpha1(III) with the Saccharomyces
cerevisiae alpha mating factor prepro sequence led only to a minor increase in
the amount secreted. Immunoelectron microscopy studies indicated that the
procollagen molecules accumulate in specific membranous vesicular compartments
that are closely associated with the nuclear membrane. Prolyl 4-hydroxylase, an
endoplasmic reticulum (ER) lumenal enzyme, was found to be located in the same
compartments. Non-helical proalpha1(III) chains produced by expression without
recombinant prolyl 4-hydroxylase likewise accumulated within these compartments.
The data indicate that properly folded recombinant procollagen molecules
accumulate within the ER and do not proceed further in the secretory pathway.
This may be related to the large size of the procollagen molecule.
PMID- 10686424
TI - Deletion of cysteine 369 in lysyl hydroxylase 1 eliminates enzyme activity and
causes Ehlers-Danlos syndrome type VI.
AB - This study describes the relative contribution of the 10 cysteine residues in
lysyl hydroxylase 1 (LH1) to enzyme activity. We have identified a novel mutation
of a 15-bp deletion in exon 11 in one LH1 allele, that codes for amino acids 367
371 (DLCRQ), in two unrelated compound heterozygous patients with Ehlers-Danlos
type VI. The mutations in their other alleles were a C1119T change (exon 10) and
a predicted Q49X (exon 2). We confirmed that the loss of cysteine 369 in the
deleted sequence contributed to the diminished enzyme activity by
structure/function analysis of mutant LH1 constructs, in which C369 and the nine
other cysteines were individually mutated to serine by site-directed mutagenesis
of a normal pAcGP67/LH1cDNA construct. Following their expression in an Sf9
insect cell/baculovirus system, SDS-PAGE and Western analysis showed that
equivalent levels of correctly-sized (85-kDa) products were secreted. The
mutation of residues C369 and also C375, C552 and C687 virtually eliminated LH
activity, whereas mutations of C267, C270, and C680 had an intermediate effect.
In contrast, the C204S, C484S and C566S constructs had normal activity. Although
disulfide bond formation may affect the relative contribution of each cysteine to
LH activity, catalytic activity does not appear to be directly related to
dimerization of the enzyme.
PMID- 10686425
TI - Effects of epidermal growth factor on collagen expression by rat kidney mesangial
cells in culture.
AB - Increased collagen production by mesangial cells plays a key role in the
development and progression of glomerular sclerosis. These changes reflect in
part the impact of growth factors on mesangial cells. Since mesangial cells
possess receptors for epidermal growth factor (EGF) and since previous studies
have documented that EGF affects collagen synthesis in other cell types, we have
examined the effects of EGF on collagen biosynthesis by rat kidney mesangial
(RKM) cells in culture. Exposure for 24 h to EGF did not substantially affect the
growth rate of RKM cells. While the types of collagen produced by RKM cells
(types I, III, IV and V) were unaltered by exposure to EGF, total collagen
production was reduced ( approximately 50%). This decrease in collagen expression
was not uniform for each collagen type. Type I collagen production was inhibited
by approximately 50%, both type III and type IV expression were each reduced by
approximately 30%, but type V collagen production was suppressed by only
approximately 15%. The reduction in type I collagen synthesis was accounted for
mainly by a decrease in type I homotrimer production. Since type I molecules
represent approximately 95% of the total collagen produced, the decrease in
overall collagen expression reflects a specific suppression by EGF on type I
homotrimer production in mesangial cells. As EGF exposure resulted in a decrease
in collagen production, these results suggest that the increases in synthesis and
deposition of collagen observed in several glomerular diseases likely do not
reflect the short-term effects of EGF on mesangial cells. Rather, these findings
suggest the possibility that EGF or EGF-like growth factors may ameliorate the
effects of other soluble factors that cause enhanced matrix production and
deposition in renal diseases.
PMID- 10686426
TI - Selective adhesion of macrophages to denatured forms of type I collagen is
mediated by scavenger receptors.
AB - Macrophages (Mφs) are multifunctional immune cells which are involved in the
regulation of immune and inflammatory responses, as well as in tissue repair and
remodeling. In tissues, Mφs reside in areas which are rich in extracellular
matrix (ECM), the structural component which also plays an essential role in
regulating a variety of cellular functions. A major ECM protein encountered by
Mφs is type I collagen, the most abundant of the fibril-forming collagens. In
this study, the adhesion of RAW 264.7 murine Mphis to native fibrillar,
monomeric, and denatured type I collagen was investigated. Using atomic force
microscopy, structural differences between fibrillar and monomeric type I
collagen were clearly resolved. When cultured on fibrillar type I collagen, Mphis
adhered poorly. In contrast, they adhered significantly to monomeric, heat
denatured, or collagenase-modified type I collagen. Studies utilizing anti-beta1
and -beta2 integrin adhesion-blocking antibodies, RGD-containing peptides, or
divalent cation-free conditions did not inhibit Mphi; adhesion to monomeric or
denatured type I collagen. However, macrophage scavenger receptor (MSR) ligands
and anti-MSR antibodies significantly blocked Mphi; adhesion to denatured and
monomeric type I collagen strongly suggesting the involvement of the MSR as an
adhesion molecule for denatured type I collagen. Further analysis by Western blot
identified the MSR as the primary receptor for denatured type I collagen among
Mphi; proteins purified from a heat-denatured type I collagen affinity column.
These findings indicate that Mphis adhere selectively to denatured forms of type
I collagen, but not the native fibrillar conformation, via their scavenger
receptors.
PMID- 10686427
TI - Complete exon-intron organization of the gene for human lysyl hydroxylase 3
(LH3).
AB - Lysyl hydroxylase (LH) catalyzes the formation of hydroxylysine in collagens and
related proteins by the hydroxylation of lysine residues in peptide linkages.
Three isoenzymes of LH have so far been characterized. We report here that the
human LH3 gene is 11.6 kb in size and consists of 19 exons. Transcription is
initiated at one major site and several minor sites, the first exon containing
249-335 bp of untranslated sequences and 109 bp of a translated sequence. Exons 2
18 are similar in size to those of the human LH1 gene, whereas the introns are
markedly shorter. The LH3 gene contains a total of 15 full length Alu retroposons
or partial Alu fragments of more than 100 bp, in introns 5, 6, 12, 15 and 17.
These generate a potential for genomic rearrangements, as has been shown for the
LH1 gene in Ehlers-Danlos syndrome type VI. The 5'-flanking region of the LH3
gene was found to be entirely different from that of the LH1 gene, suggesting
different regulation of these two genes.
PMID- 10686428
TI - Aminoglycoside antibiotics.
AB - In the 50 years since their discovery, the aminoglycoside antibiotics have seen
unprecedented use. Discovered in the 1940s, they were the long-sought remedy for
tuberculosis and other serious bacterial infections. The side effects of renal
and auditory toxicity, however, led to a decline of their use in most countries
in the 1970s and 1980s. Nevertheless, today the aminoglycosides are still the
most commonly used antibiotics worldwide thanks to the combination of their high
efficacy with low cost. This review first summarizes the history, chemistry,
antibacterial actions and acute side effects of the drugs. It then details the
pathophysiology of aminoglycoside ototoxicity including experimental and clinical
observations, risk factors and incidence. Pharmacokinetics, cellular actions and
our current understanding of the underlying molecular mechanisms of ototoxicity
are discussed at length. The review concludes with recent advances towards
therapeutic intervention to prevent aminoglycoside ototoxicity.
PMID- 10686429
TI - Trained discrimination of temporal patterns: cochlear implants in gerbils.
AB - The purpose of this study was to establish an animal model for the discrimination
of temporal order cues contained in electrical stimuli to the cochlea. Gerbils
were deafened and implanted in the right cochlea with a single platinum
stimulating electrode. Two groups of animals were trained in a two-way active
avoidance shuttle box paradigm to discriminate downward from upward interval
modulated pulse trains (1-100 ms). One group consisted of naive animals. The
other group had previously been trained in the same shuttle box (same behavioral
meaning) to discriminate identical pulse trains presented acoustically.
Significant discrimination performance was found in the group of naive animals.
However, over the 6-day training period, animals with previous acoustic
experience achieved no significant discrimination performance. This suggests that
temporal order cues in pulse trains can be used in cochlear implants to transmit
behaviorally relevant information but that this may be in conflict with relevant
auditory preexperience.
PMID- 10686430
TI - Behavioral and neurophysiological thresholds for electrical cochlear stimulation
in the deaf cat.
AB - Psychophysical detection thresholds for unmodulated electrical pulse trains or
for sinusoidally amplitude-modulated (SAM) pulse trains were estimated in deaf
juvenile cats using a conditioned avoidance paradigm. Biphasic current pulses
(0.2 ms/phase) were delivered by scala tympani electrodes consisting of 4-8
electrode contacts driven as bipolar pairs. Electrical auditory brainstem
response (EABR) thresholds were obtained periodically, and at the conclusion of
behavioral training, response thresholds were obtained for neurons in the
inferior colliculus (IC) and the primary auditory cortex (A1) in acute
physiological experiments in the same animals. The results of the study include:
(1) detection thresholds for unmodulated pulse trains and for SAM pulse trains
were virtually identical; (2) EABR thresholds and behavioral thresholds were
significantly correlated, although EABR thresholds consistently overestimated
behavioral thresholds; (3) the lowest thresholds in the IC and the A1 were
significantly correlated with behavioral thresholds, and (4) mean lowest
thresholds in the IC and the A1 were essentially the same as the mean
psychophysical detection threshold in the trained deaf cats.
PMID- 10686431
TI - The acquisition of grammatical and lexical structures in children with cochlear
implants: a developmental psycholinguistic approach.
AB - The acquisition of grammatical and lexical structures was studied in a sample of
10 young German-speaking children with cochlear implants (mean implantation age 2
years 3 months). Spontaneous speech samples were collected covering the first 18
months after first tune-up. At the end of this period, 8 children were able to
produce two- or multi-word utterances. Furthermore, 8 children had acquired
plural inflections on nouns, and 5 children had acquired a substantial portion of
verb inflectional morphology. Children did less well acquiring case-marked
articles, forms of the copula and modal verbs. Articles were acquired better when
they functioned as pronouns. Children had good vocabularies (type/token ratios
>/=0.25), and all but one child started language with a preference for content
words as opposed to function words.
PMID- 10686432
TI - Pituitary prolactin-secreting tumor formation: recent developments.
AB - Prolactinoma is the most common type of primary pituitary tumors. It occurs more
frequently in women than in men. Dopaminergic agonists are effective in the
shrinkage of prolactin-secreting pituitary tumor and are preferred in some
patients. However, pituitary radiotherapy may enable the long-term removal of
prolactin-secreting tumor cells. Recent evidence suggests that prolactinoma is a
heterogeneous disorder with complicated and multifactorial etiology and
pathogenesis. Apparently, a thorough understanding of prolactinoma tumorigenesis
would be important. To facilitate investigations on tumorigenesis of
prolactinoma, animal models for prolactinomas have been developed. These models
have expedited our progress in the recent years. Many researchers consider the
F(344) rat to be the most sensitive strain of rats to estrogen (E(2))-induced
prolactinoma formation. Nonetheless, E(2) treatment for 60 days also induces the
formation of pituitary prolactin-secreting adenoma in male Sprague-Dawley (SD)
rats. Evidently, the SD rat is also a good animal for prolactinoma
investigations. Following E(2) implantation, prolactinomas developed in the
eutopic adenohypophysis in situ and/or ectopic pituitary grafted under the renal
capsule in SD rats. These observations favor the hypothesis that prolactinoma
growth is the result of pathological changes in the adenohypophysis and/or
hypothalamus. In the latter case, abnormal release of hypothalamic dopamine,
GABA, or brain-gut peptides (such as cholecystokinin, vasoactive intestinal
polypeptide, galanin, angiotensin, opioid peptide, gastrin, gastrin-releasing
peptide, pancreatic polypeptide, and adrenocorticotropic hormone) results in some
of the pathological changes that may lead to hyperprolactinemia and/or
prolactinoma development. Dysregulation of prolactin synthesis and secretion may
be the result of prolactin gene modulation. In E(2)-induced rat prolactinomas,
prolactin mRNA contents and the expression of some proto-oncogenes, e.g. c-myc
and c-ras, TGFalpha and TGFbeta1 mRNA were significantly changed. The above
findings are consistent with results in human prolactinoma development. In
addition, in rats abnormal expression of the prolactin gene was correlated with
hypomethylated status of CpG sites in exons 1, 2 and 4 of the prolactin gene, as
well as the increase in hypersensitive sites to DNase 1 in the encoding region of
the prolactin gene. In E(2)-treated rats, a point mutation with a base
substitution from cytidine (C) to adenine (A) was found at the -36-bp site of the
proximal promoter of the prolactin gene in eutopic pituitary prolactinomas, but
no change was observed in the same sequence of the prolactin gene in ectopic
prolactinoma. The association of a base substitution with the hyperexpression of
the prolactin gene in eutopic prolactinomas suggests that different mechanisms
may mediate the formation of eutopic and ectopic prolactin-secreting tumors.
Melatonin decreases the expression of the prolactin gene in vitro suggesting that
this pineal hormone may be a potential anticarcinogen in vivo. It has also been
shown that MT(2) (Mel(1b)) melatonin receptors are expressed in anterior
pituitary cells. The use of melatonin as a preventive or therapeutic drug for
prolactinomas should be further investigated. In summary, improved knowledge on
tumorigenesis of prolactinomas, especially in the rat model, was noted. These
E(2)-induced rat prolactinoma models would facilitate future investigations, and
expected results shall be fruitful and exciting for the development of future
drug designs for the prevention and/or treatment of prolactin-secreting pituitary
tumors.
PMID- 10686433
TI - The effect of protein kinase C activation on G(z)-mediated regulation of type 2
and 6 adenylyl cyclases.
AB - Three serine-to-alanine mutants of the alpha subunit of the heterotrimeric G
protein G(z) (alpha(z)) were examined for their signaling properties in the
presence of phorbol ester treatment. All three alpha(z) mutants resembled wild
type alpha(z) in their abilities to inhibit alpha(s)-stimulated type 6 adenylyl
cyclase (AC6) and phorbol ester treatment reduced their magnitudes of inhibition.
Depending on the permissive condition, the betagamma-mediated stimulation of type
2 adenylyl cyclase (AC2) was differentially regulated by alpha(z) and the three
mutants. Mutation of Ser(27) but not Ser(16) of alpha(z) affected the efficient
release of betagamma subunits upon receptor activation and abolished the
stimulation of phosphorylated but not alpha(s)-stimulated AC2.
PMID- 10686434
TI - Changes in leucine uptake in the retina of the hamster after traumatic
detachment.
AB - Protein metabolism was investigated in detached hamster retinas. By sucking off
0.2 ml of aqueous humor from the anterior chamber through limbic insertion of a
27-gauge needle, a tractional force pulled off the neural retina from the retinal
pigment epithelium and created a simple detachment without retinal breaks in the
right eyes of the hamsters. The left eyes were left untouched as normal controls
and sham controls were induced by simple limbic insertion without suction. The
animals were sacrificed at selected intervals of 1, 3, 6, 9, 16, 24, 32 days
after the operation. Subsequently, scintillation counting and autoradiography
were employed to study retinal protein metabolism using leucine uptake as an
index. After tritiated leucine uptake, scintillation counting of radioactive
substance indicated that detached retinas had taken in less tritiated leucine
than normal controls from day 1 to 6 after the operation, but this change had
normalized by day 9. For autoradiography, the change in leucine uptake rate was
shown to be different in different layers. All the retinal cells seemed to show a
decreased leucine uptake with the exception of the outer nuclear layer, in which
leucine appeared to be significantly upregulated. This paper illustrates the
patterns of protein metabolism and their change after traumatic detachment as
well as their possible recovery.
PMID- 10686435
TI - Projection linkage from spinal neurons to both lateral cervical nucleus and
solitary tract nucleus in the cat.
AB - Intracellular recordings from the lumbosacral dorsal horn were made to identify
the axonal projection and the afferent innervation of the lateral cervical
nucleus (LCN) and solitary tract nucleus (STN) on the spinal neurons of
chloralose-anesthetized cats. A total of 49 neurons from laminae III-V in the
spinal dorsal horn responded to stimulation of both the LCN and STN. Of these, 28
and 21 neurons responded antidromically and orthodromically to stimulation of the
LCN and STN, respectively. Seven of the 28 antidromically activated neurons were
followed by one or more responses synaptically driven from the LCN and/or STN.
The diameter of these ascending or descending fibers was in the range of A delta
fibers. The results indicate that (1) some spinal neurons, namely spinocervical
tract-spinosolitary tract (SCT-SST) neurons, issue branched axons of A delta
fibers and dually project to both LCN and STN; (2) some SCT-SST neurons receive
innervation from both the LCN and STN; (3) some spinal neurons and interneurons
are dually innervated by descending fibers originating from both the LCN and STN,
and (4) the convergence and integration between somatic and visceral sensory
inputs might occur in the SCT-SST neurons.
PMID- 10686436
TI - Purification of rat C6 glioma plasma membranes by affinity partitioning.
AB - We have studied the feasibility of purifying rat C6 glioma plasma membranes by a
phase partitioning approach. The purification procedure involves cell
homogenization and fractionation with an aqueous two-phase polymer system
followed by selective affinity purification of plasma membranes by a wheat germ
agglutinin-coupled polymer system. We demonstrate that the two-phase affinity
partitioning technique is a simple and efficient method of isolating cell plasma
membranes with high purity and yield. Furthermore, the isolated plasma membranes
retain their functional integrity, as shown by the high-affinity insulin-like
growth factor-I (IGF-I) binding capacity of IGF-I receptors.
PMID- 10686437
TI - The role of dialyzer biocompatibility in acute renal failure.
PMID- 10686438
TI - Impaired biological activity of erythropoietin by cyanate carbamylation.
AB - AIMS: During advanced renal failure, particularly in patients with end-stage
renal disease (ESRD), proteins are carbamylated as a result of a reaction with
cyanate. Some or all of the cyanate is derived from urea. If the carbamylation of
proteins adversely alters their biologic activities, then urea must be viewed as
an uremic toxin, rather than a surrogate. Therefore, we studied the effect of
cyanate carbamylation on the erythropoietic activity of erythropoietin (EPO) in a
rodent model. METHODS: EPO was carbamylated by incubation with cyanate at 37
degrees C. The extent of carbamylation was monitored using
trinitrobenzenesulfonic acid. In Sprague-Dawley rats the erythrocyte count,
hemoglobin concentration, and hematocrit were measured after the twice-weekly
subcutaneous injection of either EPO or carbamylated EPO for 3 weeks. Two
additional control groups received physiologic saline or 0.2 ml of 1 M cyanate.
RESULTS: The level of carbamylated EPO was increased as the time of exposure to
cyanate increased from 1 to 6 h, and as the cyanate concentration increased from
8 to 2,000 mM. EPO injections caused significantly large increases in all
erythropoietic measures. Physiologic saline or 1 M cyanate-injected controls and
the carbamylated EPO-injected animals demonstrated no change from baseline in
erythropoietic parameters. CONCLUSION: These results support that EPO exposed to
high levels of cyanate in vitro demonstrates diminished biologic activity in
healthy Sprague-Dawley rats. This effect may be manifested by the carbamylation
of EPO by the cyanate. Should this occur in ESRD patients, it may contribute to
the suboptimal erythropoietic response to EPO therapy associated with high urea
levels, especially related to inadequate dialysis. Targeting dialysis doses
specifically to urea concentrations may be more important than previously
considered.
PMID- 10686439
TI - Analysis of urea nitrogen and creatinine kinetics in hemodialysis: comparison of
a variable-volume two-compartment model with a regional blood flow model and
investigation of an appropriate solute kinetics model for clinical application.
AB - To investigate an appropriate solute kinetics model for clinical application, we
analyzed urea nitrogen (UN) and creatinine (Cr) kinetics by a variable-volume two
compartmental model (2CM) and a regional blood flow model (RBF) in 44
hemodialysis patients with varying proportions of first compartmental volume and
regional volume (p(1)). Solute kinetics could not be solved in some of the
patients with higher p(1) values, and there were more solution failures by the
RBF than by the 2CM. The solute generation rate (g) and solute distribution
volume in the dry state (V(D)) increased with increases in p(1) in both models,
but there were some differences between the two models. When g was normalized by
V(D), it became relatively constant, irrespective of the p(1) value or model used
(0.133 +/- 0.029 mg/min/l by the 2CM and 0.132 +/- 0.029 mg/min/l by the RBF for
UN; 0.0200 +/- 0.0049 mg/min/l by the 2CM and 0.0198 +/- 0.0048 mg/min/l by the
RBF for Cr). The intercompartmental mass transfer coefficient (K(c); liters/min)
calculated by the 2CM decreased as p(1) increased (K(c) = -1.77.p(1) + 1.16, p <
0.0001, R = 0.999 for UN; K(c) = -0.847.p(1) + 0.556, p < 0.0001, R = 1.000 for
Cr). The systemic blood flow (Q(sys); liters/min) calculated by the RBF also
decreased as p(1) increased (Q(sys) = -11.1.p(1) + 6.21, p < 0.0005, R = 1.000
for UN; Q(sys) = -5.22.p(1) + 2.90, p < 0.001, R = 0.999 for Cr). Since the RBF
more frequently failed to solve the solute kinetics and since there was a
difference in its Q(sys) values for UN and Cr, the 2CM was considered to be a
superior model. When p(1) was extremely low, the 2CM could be transformed into a
modified variable-volume one-compartment model (1CM) which presented a similar
g/V(D) (0.133 +/- 0.029 for UN; 0.0200 +/- 0.0048 for Cr). This modified 1CM was
considered to satisfy appropriate conditions for clinical application, since it
is simpler than the 2CM and provides useful information on the dialysis dose.
PMID- 10686440
TI - Plasma C-reactive protein in hemodialysis patients: a cross-sectional,
longitudinal clinical survey.
AB - In hemodialysis patients, C-reactive protein (CRP), an acute-phase reactant, is a
sensitive and independent marker of malnutrition, anemia, and amyloidosis. The
aim of the present studies was to evaluate CRP and interleukin 6 levels in plasma
samples from long-term hemodialysis patients on different extracorporeal
modalities associated with or without backfiltration. Two hundred and forty-seven
patients were recruited in eight hospital-based centers. All patients had been on
their dialytic modality for at least 6 months. At enrollment, 46 hemodialysis
patients out of 247 (18.6%) had clinical evidence of pathologies known to be
associated with high CRP values. The 201 remaining patients were defined as
clinically stable and were on conventional hemodialysis (34%), hemodiafiltration
with infusion volumes <10 liters/session (10%), hemodiafiltration with infusion
volumes <20 liters/session (32%), and double-chamber hemodiafiltration with
infusion volumes <10 liters/session (22%). Analysis of CRP values in the
clinically stable patients showed that an unexpectedly high proportion (47%) of
the patients had CRP values higher than 5 mg/l (taken as the upper limit in
normal human subjects). The values of CRP and interleukin 6 were significantly
higher in hemodiafiltration with infusion volumes <10 liters/session than in
hemodiafiltration with infusion volumes >20 liters/session, in hemodialysis and
in double-chamber hemodiafiltration. The same pattern occurred after 6 months of
follow-up in 171 out of 201 clinically stable patients. Hemodialytic conditions
that expose to the risk of backfiltration such as low exchange volume
hemodiafiltration may induce a chronic inflammatory state as reflected by
increased plasma values of both CRP and interleukin 6, thus suggesting the need
for hemodialytic strategies that reduce (hemodialysis with low-permeability
membranes or hemodiafiltration with infusion volumes >20 liters) or eliminate
(double-chamber hemodiafiltration) backfiltration of bacteria-derived
contaminants.
PMID- 10686441
TI - Evaluation of intradialytic solute and fluid kinetics. Setting Up a predictive
mathematical model.
AB - A mathematical model of solute kinetics for the improvement of hemodialysis
treatment is presented. It includes a two-compartment description of the main
solutes and a three-compartment model of body fluids (plasma, interstitial and
intracellular). The main model parameters can be individually assigned a priori,
on the basis of body weight and plasma concentration values measured before
beginning the session. Model predictions are compared with clinical data obtained
in vivo during 11 different hemodialysis sessions performed on 6 patients with a
profiled sodium concentration in the dialysate and a profiled ultrafiltration
rate. In all cases, the agreement between the time pattern of model solute
concentrations in plasma and the in vivo data proves fairly good as to urea,
sodium, chloride, potassium and bicarbonate kinetics. Only in two sessions was
blood volume directly measured in the patient, and in both cases the agreement
with model predictions was good. In conclusion, the model allows a priori
computation of the amount of sodium removed during hemodialysis, and makes it
possible to predict the plasma volume changes and plasma osmolarity changes
induced by a given sodium concentration profile in the dialysate and by a given
ultrafiltration profile. Hence, it can be used to improve clinical tolerance to
the dialysis session taking the characteristics of individual patients into
account, in order to minimize intradialytic hypotension.
PMID- 10686442
TI - Effect of plasma exchange on serum tissue inhibitor of metalloproteinase 1 and
cytokine concentrations in patients with fulminant hepatitis.
AB - AIMS: The present study assessed whether the serum concentrations of tissue
inhibitor of metalloproteinase 1 (TIMP-1) and cytokines are altered in patients
with fulminant hepatitis and whether plasma exchange affects these
concentrations. METHODS: Fifteen patients with fulminant hepatitis, 14 patients
with severe acute hepatitis, and 20 healthy controls were included in this study.
The serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin 1beta
(IL-1beta), interleukin 6 (IL-6), transforming growth factor beta (TGF-beta), and
TIMP-1 were determined in all patients upon hospital admission and before and
after a single course of plasma exchange in the patients with fulminant
hepatitis. RESULTS: Ten out of the 15 patients with fulminant hepatitis and all
patients with severe acute hepatitis survived. Serum TNF-alpha, IL-6, TGF-beta,
and TIMP-1 levels in patients with fulminant hepatitis were significantly higher
than the levels in patients with severe acute hepatitis (p < 0.01). IL-1beta was
not detectable in either group. Plasma exchange reduced the increased serum
concentrations of TNF-alpha, IL-6, TGF-beta, and TIMP-1 in patients with
fulminant hepatitis (p < 0.01). CONCLUSIONS: These data suggest that increased
serum levels of TIMP-1 and cytokines may reflect severe hepatic inflammation and
that plasma exchange is an effective therapy to reduce these levels.
PMID- 10686443
TI - Clinical pharmacokinetics and effects of an oral sustained-release preparation of
disopyramide prescribed for patients undergoing maintenance hemodialysis.
AB - AIMS: We evaluated the clinical pharmacokinetics of a sustained-release
preparation of disopyramide phosphate (DSR) and its effects on supraventricular
arrhythmias in hemodialysis patients. METHODS: Eight hemodialysis patients with
either paroxysmal supraventricular tachycardia (PSVT) or PSVT plus paroxysmal
atrial fibrillation (Paf) were given 150 mg of DSR 2 h before each hemodialysis.
The frequency of PSVT, the duration of Paf before and 2 weeks after starting DSR
and the blood concentration of the drug were evaluated. RESULTS: There was no
significant difference between serum levels of DSR before and after hemodialysis.
The frequency of PSVT and the duration of Paf were significantly reduced by the
therapy. Side effects and electrocardiographic abnormalities did not appear
during the period. CONCLUSION: We conclude that hemodialysis does not remove DSR,
and that a single dose of 150 mg of DSR given 2 h before hemodialysis is safe and
sufficient to reduce the incidence of supraventricular arrhythmias.
PMID- 10686444
TI - Salt and hypertension in end-stage renal disease.
PMID- 10686445
TI - Cholesterol reduction and stroke occurrence: an overview of randomized clinical
trials.
AB - We performed a meta-analysis of randomized clinical trials of more than 6 months
duration to describe how fatal and nonfatal strokes are related to cholesterol
lowering and to the type of intervention. A total of 41 individual trials
including approximately 80,000 subjects and followed for an average of about 4
years were included in the overview. There was a 16% (95% CI, 7-25%) reduction in
risk of stroke among treated patients compared to control patients (test for
heterogeneity, p = 0.76). When trials that used different interventions were
separately examined, a significant reduction in stroke occurrence was observed
only for those using statins as active treatment (risk reduction 23%; 95% CI 13
33%). A variance-weighted regression analysis of the logarithmic odds ratios for
stroke incidence against the percentage of cholesterol reduction indicated that a
reduction of fatal and nonfatal stroke can be obtained for a cholesterol
reduction of 9% (95% CI 6.8-13.6%). The combined data of primary and secondary
prevention trials indicate that a large reduction of blood cholesterol,
achievable with statin drugs, can reduce the incidence of stroke.
PMID- 10686446
TI - Clinician's biases toward surgery in cerebellar hematomas: an analysis of
decision-making in 94 patients.
AB - BACKGROUND AND PURPOSE: No studies have examined clinical decision-making in
cerebellar hemorrhages. Clinical and CT features may influence surgery in
patients with a spontaneous cerebellar hematoma. One commonly accepted adage is
to remove a clot when 3 cm or larger in axial diameter on presentation CT scan.
It is possible that certain preferences impact on outcome. METHODS: We analyzed
94 patients with spontaneous cerebellar hematomas between the years of 1973-1993.
Thirty-one patients underwent suboccipital craniectomy and clot removal with or
without ventriculostomy. Deterioration denoted worsening of consciousness, new
brainstem signs, or presentation in coma. Statistical analysis was performed
utilizing a tree-based model fitted by binary recursive partitioning. Ninety-five
percent confidence intervals (CI) were calculated. RESULTS: The overall
probability of surgical intervention was 33% (CI 23-43%). The chance of surgery
in stable patients was 7% (CI 2-20%). Neurologic deterioration was seen in 54
patients (57%) and increased the prospects of a surgical procedure (52%, CI 38
66%). Surgery was performed in all deteriorating patients with small hematomas
(size <3 cm), but large clots (size >3 cm) did not substantially influence
surgical decision-making (45%, CI 30-60%) except in patients younger than 70
years old (57%, CI 41-82%). CONCLUSIONS: Clinicians at our institution usually
wait for clinical deterioration to unfold prior to operating on patients with
cerebellar hematomas. After deterioration occurs, they prefer small hematomas but
will operate on large hematomas when patients are younger than 70, generally
withholding surgery from older patients. These attitudes may impact on outcome
and should be considered in future treatment trials.
PMID- 10686448
TI - Distribution, severity and risk factors for aortic atherosclerosis in cerebral
ischemia.
AB - Significant thoracic aortic plaques (>4 mm) are an independent risk factor for
ischemic stroke. Within 1 week of stroke/transient ischemic attack (TIA) onset,
105 consecutive patients underwent transesophageal echocardiography assessment of
aortic plaque thickness using the criteria of Amarenco et al. (N Engl J Med
1994;331:1474-1479). A proximo-distal gradient was found in the distribution of
aortic atheroma >4 mm (p = 0.04). Symptomatic coronary artery disease was
associated with plaque in the proximal aorta (p = 0.03); extracranial carotid
stenosis >70% was associated with plaque in the arch and descending aorta (p <
0.01). The severity of aortic plaque was associated with age on multivariable
analysis (p = 0.0003 to p < 0.01). Only smoking showed predictive regional
specificity (p = 0.03);no other risk factors were associated with aortic atheroma
in any segment. In stroke/TIA patients, carotid stenosis >70% predicts aortic
arch atheroma plaques >4 mm which may predispose to reinfarction after
endarterectomy. Atheroma of the ascending aorta is associated with ischemic heart
disease, and cardiac screening should be considered in asymptomatic patients.
PMID- 10686447
TI - Leukocyte activation: relation to cardiovascular mortality after cerebrovascular
ischemia.
AB - Activated leukocytes are believed to be involved in the pathogenesis and
progression of atherosclerotic vascular disease and its consequences. In a 4-year
observational follow-up study, we investigated whether markers for systemic
leukocyte activation (leukocyte-derived inflammatory mediators) were related to
cardiovascular mortality after cerebrovascular ischemia. Using enzyme-linked
immunosorbent assays, we measured the plasma levels of soluble tumor necrosis
factor receptor protein-1 (sTNFR-1), neutrophil gelatinase-associated lipocalin
(NGAL) and neutrophil protease-4 (NP4) in 144 patients (90 stroke, 54 transient
ischemic attack) 1-3 days after cerebral ischemia. During the 4 years of follow
up, 42 (29%) of the 144 patients died; 38 of cardiovascular causes and 4 of other
causes. Patients with evidence of higher leukocyte activation (n = 47) had a
higher 4-year cardiovascular mortality rate than those without evidence of
leukocyte activation (n = 97; p < 0.005). Logistic regression analysis with age,
sex and other significant predictors as covariates showed higher plasma levels of
sTNFR1 and NGAL both to be significant independent predictors of cardiovascular
mortality, the respective odds ratio, 95% confidence intervals, and p values
being 2.0, 1.2-3.4, p < 0.01, and 3.6, 1.2-10.5, p = 0.02, respectively. We
concluded that in patients with acute cerebral ischemia, plasma markers of
leukocyte activation were significant predictors of long-term cardiovascular
mortality. This may indicate an important role of activated leukocytes in the
progression of these diseases.
PMID- 10686449
TI - Lipoprotein(a), other lipoproteins and hemostatic profiles in patients with
ischemic stroke: the relation to cardiogenic embolism.
AB - Lipoprotein and hemostatic profiles including coagulation inhibitors were
determined in 136 patients with acute ischemic stroke. Based on clinical
examination, cerebral computed tomography, Doppler ultrasonography of precerebral
arteries and transthoracic echocardiography, the strokes were classified as
cardioembolic (n = 38), non-cardioembolic (n = 92), and mixed
cardioembolic/hypertensive (n = 6). Patients with cardioembolic stroke were older
than patients with non-cardioembolic stroke. Lipoprotein(a) was higher in the
cardioembolic than in the non-cardioembolic group. Lipoprotein(a) was not
significantly correlated to the other lipid levels and may represent an
independent lipid risk factor. The non-cardioembolic group had higher levels of
total cholesterol, triglycerides, total cholesterol/high-density lipoprotein
cholesterol ratio, low-density lipoprotein cholesterol, apolipoprotein A1, and
apolipoprotein B. The cardioembolic group had higher concentrations of fibrinogen
and D-dimer, and lower levels of antithrombin, protein C, protein S and heparin
cofactor 2 than the non-cardioembolic group. The differences in the hemostatic
profile are consistent with thrombosis due to activated coagulation being more
involved in the pathogenesis of cardioembolic than of non-cardioembolic stroke.
Lipoprotein(a) seems to be more associated with coagulation markers of thrombosis
than with atherosclerosis, whereas the other lipids mainly seem to be risk
factors for atherosclerosis.
PMID- 10686450
TI - Cross-validation of a model predicting discharge home after stroke
rehabilitation. Validating stroke discharge predictors.
AB - A new sample of 116 stroke patients was collected in order to validate a logistic
regression model, predicting the chances of severely affected stroke patients
being discharged home to independent living. The model was found to be accurate
in the new sample, especially for those patients who had a high estimated
probability of being discharged home. When the dividing line for the predicted
probability for discharge home was set at a value of >/=0.5, the positive and
negative predictive values were 74 and 73%, respectively. Further modelling
resulted in a new extended model including the variables postural stability on
admission, cohabiting, age and perceptual impairment on admission that formed the
basis for an index predicting discharge home. This index was then validated in
the sample of 93 patients that the first developed model was derived from and
showed positive and negative predictive values of 85 and 77%, respectively.
PMID- 10686451
TI - Dynamic but not static cerebral autoregulation is impaired in acute ischaemic
stroke.
AB - It remains unclear as to whether dynamic and static cerebral autoregulation (CA)
are impaired in acute ischaemic stroke, and whether these changes are related to
stroke subtype. This could have important implications with regard to post-stroke
prognosis and the management of blood pressure (BP) in the acute post-ictal
period. Using transcranial Doppler ultrasonography and non-invasive manipulation
of BP, we compared both mechanisms in 61 patients with ischaemic stroke within 96
h of ictus, and 54 age- and sex-matched controls. There was no difference in
static and dynamic CA indices between the various stroke subtypes. Combining all
stroke subtypes dynamic autoregulation, as measured using thigh cuff release, was
significantly impaired in both the affected and non-affected stroke hemispheres
compared to controls (mean autoregulation index 4.1 +/- 3.3, 4.8 +/- 3.1 and 6.2
+/- 2.3, respectively, p < 0.05). By comparison static autoregulation, assessed
using isometric hand grip and thigh cuff inflation, was not significantly
different. In conclusion, dynamic but not static CA appears to be globally
impaired in acute ischaemic stroke. This deserves further study and may identify
possibilities for therapeutic intervention.
PMID- 10686452
TI - The Athens stroke registry: results of a five-year hospital-based study.
AB - The advent and wide application of new technology, especially noninvasive
techniques, has enabled physicians to more completely investigate and clarify the
etiopathogenic mechanisms of stroke. Such data have not been available until
recently for Southeastern Europe. In addition, during the last decades,
strategies for the modification of risk factors and primary prevention may have
changed the prevalence of each subgroup of stroke as well. We investigated 1, 042
consecutive patients who had first strokes, during a period of 5 years (from June
1992 to May 1997) and classified them prospectively based on etiopathogenic
mechanisms. Patients with transient ischemic attacks and subarachnoid hemorrhage
were excluded. There were 613 male and 429 female patients, with a mean age of
70.2 +/- 11.9 years. Forty-six percent of the patients arrived within 3 h from
stroke onset. The probable mechanisms were: large-artery atherosclerosis, 156
(15%); lacunes, 177 (17%); cardioembolic, 335 (32.1%); infarct of unknown cause,
182 (17.5%); miscellaneous causes, 35 (3.3%), and intracerebral hemorrhage (ICH),
157 (15.1%). In the cardioembolic group, nonvalvular atrial fibrillation (NVAF)
was the probable cause in 225 patients, especially in patients older than 75
years (65%). The overall hospital mortality was 15.2% (from 0.6% for lacunar
stroke to 34% for ICH). In our population, cardioembolism is the most frequent
subtype of stroke. NVAF is the most likely source, especially in older patients.
PMID- 10686453
TI - Measurement of cerebral circulation time by contrast-enhanced Doppler sonography.
AB - We present a new, non-invasive ultrasound method for the measurement of cerebral
circulation time. After injection of a galactose-based echo-contrast agent
(Levovist) into an antecubital vein, cerebral circulation time is measured as the
interval between the beginning of a stable signal enhancement of at least 5 dB in
the internal carotid artery and in the ipsilateral internal jugular vein. Both
vessels are insonated simultaneously at the mandibular angle using a single 2-MHz
range-gated transducer. For this study, 25 healthy volunteers ranging in age from
23 to 55 years (30.1 +/- 7.5 years; mean +/- SD) were examined. Cerebral
circulation time was 5.6 +/- 1.7 s without significant side-to-side or sex
related differences. Measurement of circulation times offers a new possibility
for the employment of echo-contrast agents in functional ultrasound.
PMID- 10686454
TI - Design of ESPRIT: an international randomized trial for secondary prevention
after non-disabling cerebral ischaemia of arterial origin. European/Australian
Stroke Prevention in Reversible Ischaemia Trial (ESPRIT) group.
AB - The ESPRIT trial addresses the problem that aspirin, the standard therapy for
secondary prevention of vascular complications after a transient ischaemic attack
(TIA) or ischaemic stroke of arterial origin, reduces the risk of serious
vascular events by only about 13%. Anticoagulants may be an alternative, as these
have proved highly efficacious in trials after myocardial infarction and after
cerebral ischaemia with atrial fibrillation. After cerebral ischaemia of presumed
arterial origin, high-intensity anticoagulation (INR 3.0-4.5) is not safe, but
the value of anticoagulation with an INR between 2.0 and 3.0 is still unknown.
Secondly, a recent, large trial showed that the combination of aspirin and
dipyridamole prevents more major vascular events than aspirin alone, but several
earlier trials did not find such an advantage. In ESPRIT, patients with a TIA or
minor ischaemic stroke (Rankin grade =3) will be randomized between oral
anticoagulation (INR 2.0-3.0), the combination of dipyridamole (400 mg daily)
plus aspirin (in any dose between 30 and 325 mg daily) and aspirin only. Primary
outcome is the composite event 'death from all vascular causes, non-fatal stroke,
non-fatal myocardial infarction or major bleeding complication', whichever occurs
first. Outcome assessment will be blinded. The recruitment of a total of 4,500
patients from more than 10 countries is planned; the mean follow-up will be 3
years.
PMID- 10686455
TI - Cerebral artery thrombosis as a cause of striatocapsular infarction. a
histopathological case study.
AB - Striatocapsular infarction is a distinct form of stroke, but few
histopathological studies have been performed concerning acute lesions. We report
the postmortem findings of a patient with an infarct who died shortly after
onset. A 72-year-old man died of acute myocardial infarction 6 days after the
onset of left-sided striatocapsular infarction. Autopsy revealed thrombus
formation of the left middle cerebral artery (MCA) trunk. The lateral striate
arteries irrigating the area of the infarct branched off distal to the arterial
segment occluded with a thrombus. The cortical vessels were perfused by
leptomeningeal collaterals. This report histopathologically confirmed thrombus
formation of the MCA resulting in striatocapsular infarction.
PMID- 10686456
TI - Diffusion-weighted MRI in acute mutism.
AB - Mutism defined as a complete loss of speech may be related to psychiatric or
neurologic disorders. The ischemic stroke origins of mutism are often difficult
to assess at the acute stage. Accordingly, the search for the underlying
mechanism as the localization of the damages may be difficult by conventional
radiological techniques. Diffusion-weighted (DWI) MRI may accurately identify
patients with acute ischemic stroke and distinguish them from those who mimic
acute stroke better than clinical and conventional neuroradiological methods.
This report aims to demonstrate the utility of DWI-MRI in the diagnosis of acute
mutism.
PMID- 10686457
TI - Cervical artery dissections in the puerperium: pathogenic hypotheses concerning
seven observations.
PMID- 10686458
TI - Raeder's syndrome: a rare presentation of internal carotid artery dissection.
PMID- 10686459
TI - Hereditary thrombophilia in cerebral venous thrombosis.
PMID- 10686460
TI - The migraine-PFO connection is independent of sex.
PMID- 10686461
TI - Acute lethal stroke affecting all brain-supplying cerebral arteries due to
paradoxical embolism through a patent foramen ovale.
PMID- 10686462
TI - Critical illness polyneuropathy. A 2-year follow-up study in 19 severe cases.
AB - Critical illness polyneuropathy (CIP) is a reported cause of varying degrees of
neuromuscular weakness in patients with multiple organ failure. Little is known
concerning predictive factors of neurological recovery. The critical care
conditions, neurological explorations and 2-year clinical follow-up of 19
patients who suffered from severe forms (quadriplegia or quadriparesis) of CIP
were analyzed. Characteristics of patients who recovered clinically were compared
with those of patients who did not. Two patients died within 2 months, 11
recovered completely, 4 remained quadriplegic and 2 remained quadriparetic. All
patients suffered from sepsis, multiple organ dysfunction syndrome and a
catabolic state before the onset of CIP. Outcome appears difficult to predict
with clinical or electrophysiological data. Three parameters were significantly
correlated with poor recovery: longer length of stay in the critical care unit,
longer duration of sepsis and greater body weight loss. A relationship seems to
exist between the severity of CIP and that of sepsis and its associated
hypercatabolism. The favorable outcome usually attributed to CIP must be
reconsidered. The authors recommend aggressive measures against sepsis to limit
CIP and its sequelae.
PMID- 10686463
TI - A randomized, double-blind placebo-controlled trial of iron in restless legs
syndrome.
AB - BACKGROUND: Previous open-label trials have shown iron to be efficacious in the
treatment of restless legs syndrome. We performed a randomized, double-blind,
placebo-controlled trial of iron sulfate. METHODS: Twenty-eight patients were
randomized to receive either ferrous sulfate 325 mg b.i.d. or placebo for 12
weeks. The primary outcome measure was the dichotomous variable of improvement or
no improvement in average quality of sleep as recorded by a visual analog scale
nightly over a 2-week period, comparing a pretreatment 2-week baseline to weeks
13-14. Secondary outcome measures included a comparison of the quality of sleep
as measured by a visual analog scale, effect of restless legs syndrome on life as
a whole as measured by a different visual analog scale, and the percentage of
nights patients were symptomatic. RESULTS: No significant differences were noted
between iron and placebo groups for both primary and secondary outcome measures.
Responders taking iron did have a significant increase in their iron saturation
compared to nonresponders taking iron. CONCLUSIONS: Iron sulfate does not appear
to be an effective empiric treatment for restless legs syndrome.
PMID- 10686464
TI - Apraxia of single tool Use.
AB - We report a 72-year-old right-handed man who showed an 'apraxia of tool use'
after a cerebral infarct in the territory of the left middle cerebral artery. His
apraxia of tool use was characterized by a clear dissociation between the
inability to use a single tool and the ability to use plural tools. Most of the
errors occurred in selecting an appropriate target where a tool is expected to be
applied. Detailed examinations confirmed that his conceptual knowledge of tool
use was well preserved. Furthermore, when a target of a tool was provided as a
cue, he used a single tool correctly. These results suggest that his inability to
use a single tool originated from his inability to evoke a target image from an
actual tool.
PMID- 10686465
TI - Hereditary cerebellar ataxia with peripheral neuropathy and mental retardation.
AB - We present here 5 patients with hereditary cerebellar ataxia with peripheral
neuropathy and mental retardation as determined by clinical, pathological, and
molecular studies. The most characteristic features of this disorder, in contrast
to Friedreich's ataxia, were early onset of ataxic gait, mental retardation, and
a marked atrophy of the cerebellum. Sural nerve biopsy showed a reduction of
myelinated fibers. The expansion of a GAA triplet repeat within the first intron
of the frataxin gene, which causes Friedreich's ataxia, was not identified in any
of the patients. Hereditary cerebellar ataxia with peripheral neuropathy and
mental retardation represents a specific clinical entity that so far has only
been described in Japan.
PMID- 10686466
TI - Type I sialidosis: a clinical, biochemical and neuroradiological study.
AB - We report biochemical, morphological and neuroradiological findings in a 40-year
old woman affected with type I sialidosis. The clinical symptoms, consisting of a
cerebellar syndrome, were first noted at the age of 17 years. The macular cherry
red spot was first observed after 23 years of disease. A CT scan performed at 21
years of age showed enlargement of the fourth ventricle. Nuclear magnetic
resonance imaging of the brain performed at the age of 40 showed severe atrophy
of the cerebellum and pontine region; atrophy of cerebral hemispheres and of the
corpus callosum was also observed. We emphasize the prolonged course of illness
in this patient, observed over a long period of time. Of particular interest is
the neuroradiological study showing our findings both at the beginning of the
disease and after 20 years.
PMID- 10686467
TI - Acute challenge with apomorphine and levodopa in Parkinsonism.
AB - BACKGROUND: The diagnosis of different parkinsonian syndromes and the ability to
predict long-term drug efficacy constitute important clinical issues. DESIGN:
Motor responses to the acute administration of levodopa and apomorphine were
analyzed in a series of 134 parkinsonian patients, including 83 patients with a
clinical diagnosis of idiopathic Parkinson's disease (PD), 28 patients with
multiple-system atrophy (MSA), 6 with progressive supranuclear palsy, and 17 with
an unclassified parkinsonian syndrome. METHODS: The patients received oral
levodopa/carbidopa (250/25 mg) and subcutaneous apomorphine (1.5, 3 and 4.5 mg).
Clinical variations of the Unified Parkinson's Disease Rating Scale (UPDRS) motor
score were evaluated 1 h following levodopa administration or 20 min following
apomorphine. The motor improvement produced by each acute challenge was matched
with the clinical diagnosis and with the response to chronic levodopa treatment.
The diagnosis was verified by repeated clinical assessments or by autopsy in 2
cases. A receiver operating characteristics curve was plotted comparing PD vs.
non-PD, PD vs. MSA and chronic responders vs. nonresponders. Cutoff threshold
improvement was defined as the value closest to the crossing point for 80%
sensitivity and 80% specificity, corresponding to the best trade-off for a
predictive evaluation. RESULTS: UPDRS motor score improvement was on average
higher in PD than in non-PD patients (levodopa: 29.8 vs. 12.2%; apomorphine 1.5
mg: 27.1 vs. 10.5%; apomorphine 3 mg: 27.7 vs. 9.7%; apomorphine 4.5 mg: 28.8 vs.
11.8%; p < 0.01 with Student's t test). When PD patients were compared to non-PD
patients, levodopa challenge had the best diagnostic accuracy with a threshold
improvement of 16%. Apomorphine had the best diagnostic accuracy with a threshold
improvement of 13.5% for 1.5 mg, 13% for 3 mg, and 16% for 4.5 mg. This meant
that patients improving at least 16% in all tests had the highest probability of
having PD. When PD patients were compared to MSA patients, levodopa acute
challenge had the best diagnostic accuracy with a threshold improvement of 17%.
Apomorphine had the best diagnostic accuracy with an improvement of 13% for 1.5
mg, 15% for 3 mg, and 18% for 4.5 mg. This meant that patients improving at least
18% in all tests had the highest probability of having PD rather than MSA. When
patients who responded to chronic levodopa treatment were compared to those who
did not, acute challenge with levodopa had the best predictive accuracy with a
threshold improvement of 14.5%. Apomorphine had the best predictive accuracy with
an improvement of 13% for 1.5 mg, and 14% for 3 and 4.5 mg. This meant that
patients improving at least 14.5% in all tests had the highest probability of
responding to chronic treatment. CONCLUSION: A good agreement was found between
acute challenges with levodopa/carbidopa and apomorphine, and the use of both
improved the reliability of the test. Different threshold improvements after
acute challenges would support a diagnosis of PD or the exclusion of MSA, and
would have a predictive value for subsequent response to chronic levodopa
therapy.
PMID- 10686468
TI - An epidemiological study to assess migraine prevalence in a sample of Italian
population presenting to their GPs.
AB - This multicentre, observational, cross-sectional study was conducted to determine
migraine prevalence in a sample of population presenting to their GPs. The study
covered all the patients who visited the GPs practice, for any reason, on 5
consecutive days of 2 different weeks. A total of 71,588 patients were
interviewed by 902 GPs. The prevalence of migraine in this sample was 11.6%.
PMID- 10686469
TI - Chronic fatigue syndrome in patients with Lyme borreliosis.
AB - Several authors have reported a chronic fatigue-like syndrome in patients that
have suffered from Lyme borreliosis in the past. To further investigate this
suspicion of an association without sample bias, we carried out a prospective,
double-blind study and tested 1, 156 healthy young males for Borrelia antibodies.
Seropositive subjects who had never suffered from clinically manifest Lyme
borreliosis or neuroborreliosis showed significantly more often chronic fatigue
(p = 0.02) and malaise (p = 0.01) than seronegative recruits. Therefore we
believe it is worth examining whether an antibiotic therapy should be considered
in patients with chronic fatigue syndrome and positive Borrelia serology.
PMID- 10686470
TI - Quadriceps atrophy after knee traumatisms and immobilization:
electrophysiological assessment.
AB - Automatic analysis of EMG (T/A analysis) and invasive muscle fiber conduction
velocity in situ (MFCV) were performed in 15 patients after traumatic lesions of
the knee and immobilization with quadriceps atrophy. T/A analysis showed
transient reduced number of turns, consistent with inhibition of quadriceps
motoneurons, that recovered within the first 2 weeks after the plaster cast had
been removed. MFCV was significantly slowed and showed a gradual improvement,
reaching normal values after 6 weeks. These results suggest that decrement in
activated motor units may be the cause of the disproportionate weakness of the
quadriceps muscle on the first days after immobilization by the plaster cast. The
recovery of MFCV was related with functional improvement of strength after the
first weeks.
PMID- 10686471
TI - Multiple cognitive impairments associated with systemic lupus erythematosus and
antiphospholipid antibody syndrome: A form of progressive vascular dementia?
PMID- 10686472
TI - Mumps cerebellitis.
PMID- 10686473
TI - Epilepsia cursiva. The forgotten running fits.
PMID- 10686474
TI - An adult form of L-2-hydroxyglutaric aciduria revealed by tremor.
PMID- 10686475
TI - Acute isolated ophthalmoplegia associated with high levels of anti-GQ1b
antibodies.
PMID- 10686476
TI - Superficial siderosis of the central nervous system in a patient with
neurofibromatosis type I.
PMID- 10686477
TI - Eurojunction '99. The 5th European Conference on Myasthenia Gravis and Other
Disorders of the Neuromuscular Junction. Organised by Renato Mantegazza,
Ferdinando Cornelio and Klaus Toyka and their colleagues, held in Sportilia,
Italy, June 1999.
PMID- 10686478
TI - Organizations and gene duplications of the human and mouse MHC complement gene
clusters.
AB - The MHC complement gene cluster (MCGC) in most people contains thirteen
structural genes, pseudogenes and gene segments. Novel genes RD, SKI2W, DOM3Z and
RP1 are organized as two head-to-head gene pairs between complement gene Bf and
the first locus of C4. Southern blot analysis shows that single-copy genes for
DOM3Z are detectable in primates and other mammals. Sequence analyses revealed
that the exon- intron structures of human and mouse DOM3Z genes are identical.
Both human and mouse DOM3Z transcripts exhibit splice variants at the 5' regions,
although the open reading frames remain identical. Cloning and characterization
of the mouse RP1 cDNA revealed a reading frame for 254 amino acids with a
bipartite nuclear localization signal close to the amino terminus. The mouse RP1
gene consists of 7 exons and spans 12.9 kb. Located in intron 4 of mouse RP1 is
an endogenous retrovirus that probably confers the androgen-responsive expression
of the Slp protein in certain male mice. The availability of the complete human
and mouse MCGC genomic and cDNA sequences allows further deliberate analyses of
gene duplications and evolution. The intergenic region between mouse SLP and C4
genes is more than six times larger than the corresponding region in humans. It
contains the functional gene steroid CYP21A, long stretches of repetitive DNA
elements, and three partially duplicated gene segments TNXA, SKI2W2 and RP2. The
modular duplications of human and mouse RP-C4-CYP21-TNX (RCCX) are sharply
different as SKI2W2 is absent in the human MCGC, and TNXA and RP2 are smaller in
size but higher in sequence conservation in humans.
PMID- 10686479
TI - Novel polymorphism in the coding region of the IL-13 receptor alpha' gene:
association study with atopic asthma in the Japanese population.
AB - Interleukin (IL)-4 and IL-13 play key roles in the development of atopic asthma.
The IL-13 receptor (R) alpha' chain is a component of both IL-4R and IL-13R
complexes. By screening the whole coding region of the IL-13Ralpha' gene for
polymorphisms, we identified a new polymorphism at nucleotide position 1050 from
the ATG start codon. The allelic frequency of the C/T polymorphism in the
Japanese population was found to be 0.97:0.03. Because of the low frequency of
the T allele, the association study failed to indicate any significant
association between this polymorphism and atopic asthma in the Japanese
population. Further studies are required in other racial groups with higher
frequencies of this polymorphism to elucidate the association.
PMID- 10686480
TI - Complement component C6 polymorphism: novel protein-typing technique and
distribution of allotypes in Germany.
AB - The genetic polymorphism of human C6 was investigated in Germany using an
improved technique: polyacrylamide gel isoelectric focusing and subsequent direct
immunofixation with monospecific C6 antisera. Typing of C6 was performed on
native serum samples from 1,775 unrelated persons. The gene frequencies in the
population study were as follows: C6*A 0.6313, C6*B 0.3566 and the rare alleles
C6*R 0. 0121. In total, 8 rare allotypes were analysed. The gene frequencies
obtained are in good agreement with those previously published.
PMID- 10686481
TI - Two human gene families display preferences for different nucleotides and have
distinct codon usage patterns.
AB - Analysis of base composition has proven important for functional gene analysis.
By comparing base composition and codon usage between two specific human gene
families we were able to show a highly conserved nucleotide distribution among
the members of one gene family and a significant difference between the two
families. The two groups selected for analysis were the human factor H gene
family, which represents six secreted human plasma proteins with functions in
immune defense, and a class of four human zinc finger proteins, termed early
growth response (EGR) proteins, which represent DNA-binding transcription
factors. The nucleotide distribution of each gene family is distinct: members of
the factor H gene family represent AT-rich genes, displaying an overall AT
nucleotide content of 62.8% and a particular preference for A nucleotides
(33.9%). In contrast, the EGR genes are GC-rich (55.9%) and C nucleotides are
used in 31.2%. This nucleotide difference affects codon usage among synonymous
codons and is considered of biological significance, as it affects DNA stability.
The codon preference is particularly high at codon position 3, where each family
selects for codons which have the preferred nucleotide at this silent third
position. At position 3, A nucleotides are preferred by factor H genes in 36.3%
of the 2, 503 codons analyzed, compared to 10% of the 1,876 codons analyzed for
the EGR family. In contrast, C nucleotides are used by the EGR family in 48.1%,
compared to 16% of the triplets used by the factor H gene family. This comparison
of two human gene families shows that nucleotide distribution and codon usage is
not uniform within the human organism and the described differences most likely
represent selection constraints between the polymorphic factor H and highly
conserved EGR genes.
PMID- 10686482
TI - The human T cell receptor beta variable (TRBV) genes.
AB - 'Human T Cell Receptor Beta Variable (TRBV) Genes', the seventh report of the
'IMGT Locus on Focus' section, comprises four tables: (1) 'Number of human
germline TRBV genes at 7q35 and potential repertoire'; (2) 'Human germline TRBV
genes at 7q35'; (3) 'Human TRBV orphons on chromosome 9 (9p21)', and (4) 'Human
TRBV allele table'. These tables are available at the IMGT Marie-Paule page from
IMGT, the international ImMunoGeneTics database (http://imgt.cines. fr: 8104)
created by Marie-Paule Lefranc, Universite Montpellier II, CNRS, France.
PMID- 10686483
TI - Hormones associated with non-maternal infant care: a review of mammalian and
avian studies.
AB - Hormonal changes during non-maternal infant care have been demonstrated in many
cooperatively breeding bird species, some monogamous rodents and two species of
New World primates. Coevolution of hormones and social traits may have provided
for the different breeding systems that occur today. Several hormones have been
shown to covary with the breeding systems of vertebrates. Elevated levels of the
hormone prolactin with male parenting behaviours are common to many birds,
rodents and the callitrichid monkeys Callithrix jacchus and Saguinus oedipus. In
birds, prolactin may be elevated in both male and female breeders during various
stages of nest building, egg laying, incubating and feeding of young.
Testosterone levels appear to have an inverse relationship to prolactin levels
during infant care in birds and rodents, but this relationship has not been
examined for primates. In cooperatively breeding birds, helpers who remain at the
nest also have elevated levels of prolactin when displaying parental care
behaviours. Prolactin levels are elevated in helper callitrichid monkeys during
the postpartum period. Monogamous male rodents demonstrate elevated prolactin
levels with parental care behaviour but, in contrast to the birds, the mechanisms
mediating prolactin increase appear to differ for male and female rodents. Two
factors may influence male parental behaviours and hormonal changes: stimuli from
the pregnant female and stimuli from the newborn pups; whereas maternal
behaviours are influenced by the maternal hormones of the female and the pup
stimuli. An experiential factor may also influence male parental behaviours.
Neuropeptides such as oxytocin and vasopressin appear to be involved in male
rodent parental care and there may be an interaction between a series of hormones
and neurosecretions and stimuli from mates and pups. Studies of Saguinus oedipus,
the cotton-top tamarin, suggest that prolactin levels are responsive to stimuli
from contact with infants and the level of infant care experience influences the
levels of prolactin with male infant care. Father tamarins also have elevated
levels of prolactin before the birth of infants suggesting that cues from the
pregnant female are important. Prolactin's role in parental care may have evolved
from prolactin's role in other reproductive functions. Hormonal regulation of non
maternal care may occur due to a complex interaction of many hormones and
neurotransmitters. Studies described here should provide the impetus for further
work on parental care hormones in a wide variety of primates.
PMID- 10686484
TI - Prolactin levels of fathers and helpers related to alloparental care in common
marmosets, Callithrix jacchus.
AB - Previous studies have suggested that prolactin may play a role in regulating
allocare behaviour in cotton-top tamarins, Saguinus oedipus. In this study, we
investigate the prolactin profile of 3 groups of captive common marmosets,
Callithrix jacchus. Carrying behaviour in this species was observed after
parturition. Prolactin assays of blood samples of both fathers and helpers (sub
adult non-fathers) in 3 family groups were taken for 8 weeks before and after
birth of the infants. The after-birth condition was divided into 2 groups:
carrying and non-carrying animals. The results suggest a relationship between
prolactin levels and allocare behaviour, with carrying behaviour being associated
with increased prolactin in both fathers and helpers. This suggests that extra
prolactin is produced in response to physical contact, and may be associated with
carrying behaviour. Also, prolactin production may be related to learning
parental skills in Neotropical primates.
PMID- 10686485
TI - Effects of allocare-givers on fitness of infants and parents in callitrichid
primates.
AB - The effects of callitrichid primate helpers (allocare-givers other than an
infant's father) on the survival, reproduction or behavior of infants and parents
are reviewed, using both published studies and data from free-ranging golden lion
tamarins (Leontopithecus rosalia). Three lines of evidence suggest that helpers
may increase their own inclusive fitness: (1) The number of adult males acting as
helpers in free-ranging groups is correlated with the number of surviving infants
in 3 callitrichid species. However, the lack of a negative correlation with
number of infants dying suggests that activities other than direct infant care
(e.g. territory defense) may be more important, especially in newly formed
groups. (2) In 2 species, captive groups with helpers carry infants for longer
periods of time than do groups without helpers. Whether such differences would
translate into meaningful survival differences in free-ranging groups is unclear.
(3) Helpers reduce the energetic burden of parents by reducing the amount of time
they spend transporting or provisioning infants in at least 4 species.
Reproductive males are more likely than reproductive females to benefit from the
presence of helpers, reducing their investment in infant care activities as the
number of helpers in the group increases. In free-ranging golden lion tamarins,
the reproductive tenure of males, but not females, increases with the number of
helpers in the group, suggesting that a reduction in energetic investment may
translate into increased survival. 'Decisions' made by helpers to participate in
infant transport are weighed against competing needs for foraging, vigilance,
territory defense and, in some cases, prospecting for breeding opportunities.
Given this complexity, a sophisticated model may be required to answer the
question of how helpers 'decide' to participate in infant care versus other
activities.
PMID- 10686486
TI - Allocare in a nocturnal primate: data on the spectral tarsier, Tarsius spectrum.
AB - Non-maternal infant care in many of the small-bodied New World primate species
has been hypothesized by some researchers to be related to the high infant/adult
weight ratio found in these species. The spectral tarsier, Tarsius spectrum, an
Old World primate, has one of the highest infant/adult weight ratios of any
primate, with infants weighing between 20-33% of adult weight at birth. On the
basis of the hypothesized relationship between allocare and the infant/adult
weight ratio, it is predicted that the spectral tarsier will also exhibit
extensive allocaretaking behaviour. The results of this study indicate that
although spectral tarsiers show care by male and female subadults as well as
adult males, it is extremely limited compared to the extensive allocaretaking
behavior observed in New World primate species such as Aotus and Callicebus.
Spectral tarsier subadult females provide substantially more allocare to infants
than do subadult males or adult males. Female subadults were observed sharing
food, transporting, grooming, playing, alarm calling, baby-sitting and
maintaining physical contact with infants more than other age/sex classes.
Although the amount of allocare exhibited by adult males and subadult males was
much less than that exhibited by female subadults, the data suggest that adult
and subadult male spectral tarsiers do play a small part in the care and
socialization of the infant. Adult males and subadult males were both observed
occasionally engaging in allocaretaking behaviors such as grooming and playing,
as well as frequently patrolling and defending the territory's boundaries. The
results from this study suggest that although a high infant/adult weight ratio
may be a prerequisite for selection to favor extensive allocare, it is not a
causal factor. Additional research is needed in order to understand better the
selective pressures involved and the costs and benefits of providing allocare to
subadults and adult male spectral tarsiers.
PMID- 10686487
TI - Allocare patterns among cercopithecines.
AB - Cercopithecines show two general patterns of allocare. Many guenons permit
extensive contact with young infants, while most baboons and macaques restrict
early contact. Here social, ecological and life history variables among
cercopithecines are examined for evidence of relationships with allocare
patterns. This analysis suggests that in this group early allocare is most
extensive in species with relatively relaxed social relationships among females,
marked seasonal breeding and rapid rates of reproduction.
PMID- 10686488
TI - Allocare, predation risk, social structure and natal coat colour in anthropoid
primates.
AB - Many primate species have a natal coat coloured differently from the coat colour
of adults and, in some cases, the natal coat is very different from that of older
animals with the infant being conspicuous and/or brightly coloured. This study
uses data from 82 anthropoid species to investigate possible correlates of
conspicuous natal coat colour (CNC), using comparative, phylogenetically
controlled analyses. Five hypotheses were tested using statistical tests on both
species data and phylogenetically controlled data. The analyses show some support
for the hypothesis that CNCs have evolved to promote allocare but the degree of
CNC does not correlate with predation rates, arboreality, or relative testes
size.
PMID- 10686489
TI - A Prisoner's Dilemma model of the evolution of paternal care.
AB - The heavy energetic demands of gestation, lactation and rearing of offspring mean
that studies of paternal care in primates usually focus on female reproductive
effort. Here it is shown that both male and female reproductive effort must be
considered in order to understand how paternal care evolved. This is done using
the Prisoner's Dilemma, best known as a model of reciprocal altruism. It is found
that the relative cost of reproduction for males and females is crucially
important in determining co-operative and competitive strategies. In particular,
when male reproductive costs are less than female reproductive costs, males co
operate with females even when females do not reciprocate. This surprising
behaviour, termed non-reciprocal altruism, is comparable with male investment in
a female and her offspring.
PMID- 10686490
TI - The evolution of non-maternal care in anthropoid primates: a test of the
hypotheses.
AB - The amount of non-maternal care (allocare) found in primates varies greatly from
species to species. Our paper examines this variation and focuses on possible
reasons why mothers in some anthropoid primate species are prepared to relinquish
their infants to other carers whereas others are not. We use data collected from
the literature to test a number of hypotheses that attempt to explain the
observed variation in non-maternal care. Analyses were carried out using
comparative methods that control for the influence of both body size and
phylogeny on life-history and ecological variation. The results support previous
studies of both primates and other mammals in finding a clear link between the
amount of allocare provided and female reproductive rates. Species with high
allocare levels grow rapidly post-natally and wean their infants at a younger age
(but at the same relative size) than species of the same body size with lower
allocare levels. This early weaning allows high allocare species to support
higher birth rates than low allocare species but does not result in earlier
maturation. Our results, therefore, suggest that mothers allow non-maternal care
of their infants in order to increase their own reproductive output. It is not
clear whether such a strategy also benefits the infant, as we could find no link
between the presence of allocare and early maturation (which would increase the
infant's reproductive output) or between allocare levels and infant survival (as
measured by vulnerability to infanticide). This suggests that mothers and infants
might come into conflict over transfer to other carers, as the benefits to the
mother may not be accompanied by benefits to the infant. However, although
mothers may benefit from allocare in some circumstances, they will not be
expected to allow allocare if the costs are high (e.g. if there is a high risk to
the infant).
PMID- 10686491
TI - Physical and cDNA mapping in the DBH region of human chromosome 9q34.
AB - Chromosome 9q34 has been extensively studied and mapped due to the presence of
known disease genes, principally tuberous sclerosis 1 (TSC1), in this region.
During the course of our mapping of this region we constructed a 555-kb contig
beginning approximately 50 kb proximal to the dopamine-beta-hydroxylase (DBH)
gene and extending, with one small deletion, distal to the D9S114 marker. The
contig consists of 11 P1 clones, four PAC clones, one BAC clone and six cosmid
clones and contains 27 new nonpolymorphic STSs. We have found the region to be
unstable in P1, PAC and BAC cloning vehicles and have identified several deleted
genomic clones. In addition, we have isolated and mapped the 3' portions of three
putative genes located within or immediately distal to the DBH gene, including
one large gene that runs on the opposite strand to DBH and utilizes portions of
two DBH exons. The genomic clones of the contig, cDNAs and new STSs will be
useful reagents for the further study and mapping of this region.
PMID- 10686492
TI - Glucose-6-phosphate dehydrogenase deficiency in Kuwait, Syria, Egypt, Iran,
Jordan and Lebanon.
AB - A total of 3,501 male subjects from six Arab countries living in Kuwait were
investigated for quantitative and phenotypic distribution of red cell glucose-6
phosphate dehydrogenase (G6PD). The ethnic origins of those investigated were
Kuwait, Egypt, Iran, Syria, Lebanon and Jordan. The distribution of G6PD
deficiency among the different ethnic groups varied widely, ranging from 1.00%
for Egyptians to 11.55% for Iranians. The activity of the normal enzyme was
remarkably similar, with values ranging from 6.1 +/- 0.8 to 6.5 +/- 1.1 IU/g Hb.
A low frequency of the Gd(A) allele was found in two ethnic groups, Egyptians
(0.019) and Iranians (0.014). Gd(A-) was present at the very low frequency of
0.006 in another two ethnic groups, Kuwaitis and Jordanians.
PMID- 10686493
TI - Screening of deletions in SMN, NAIP and BTF2p44 genes in Turkish spinal muscular
atrophy patients.
AB - Deletions of the spinal muscular atrophy (SMA)-determining gene, SMN1, NAIP, and
a third multicopy gene, BTF2p44tel were investigated in 60 unrelated Turkish SMA
patients. SMN1 was deleted for at least exons 7 and 8 in 85% of the Turkish SMA
patients. The NAIP gene was deleted in 75 and 33% of type I and type II SMA
patients, respectively. Analysis of the 5'end of the BTF2p44tel gene indicated
the extension of deletion in 13.3% of the cases, mainly in type I patients.
Deletions of the NAIP and BTF2p44tel genes were detected in 1.3 and 3.9% of
carrriers, respectively, in Turkish SMA families. Two patients were detected to
harbor the hybrid SMN gene, one type II with deletion of the NAIP gene, and one
type III without deletion of the NAIP gene.
PMID- 10686494
TI - Linkage of hereditary distal myopathy with desmin accumulation to 2q.
AB - We are investigating the genetics of a large family with an autosomal dominant
form of hereditary distal myopathy. This slowly progressive myopathy begins
during early adulthood in the distal leg muscles, producing a gait disturbance.
Cardiomyopathy is also present in most affected family members, manifesting
itself as conduction block or congestive heart failure. Histologically, an
accumulation of the protein, desmin, occurs in the subsarcolemmal spaces of
myofibers. We have performed linkage analyses of this family, and have mapped the
location of the gene causing the myopathy to human chromosome 2q33. The gene is
within a 17-cM segment of chromosome 2q bounded by the DNA markers D2S2248 and
D2S401. The best candidate gene for this myopathy is desmin.
PMID- 10686495
TI - Analysis of the SMN and NAIP genes in slovak spinal muscular atrophy patients.
AB - We identified homozygous absence of exon 7 of the telomeric copy of the survival
motor neuron gene (telSMN) in 88.4% (38/43) of spinal muscular atrophy (SMA)
patients from Slovakia. Additional deletions within the neuronal apoptosis
inhibitory protein (NAIP) gene were found in 38.5% of type I, 12.5% of type II
and never in type III SMA patients. Neither the SMN nor the NAIP gene was deleted
in 81 healthy relatives and 25 controls tested. In one family, pseudodominant
inheritance was identified. Both the type III SMA father and type II SMA son
carried the homozygous deletion of the telSMN gene. One SMA I patient showed an
SMN hybrid gene, probably created by intrachromosomal deletion. In two
haploidentical type II SMA sibs, the telSMN exon 7 was absent on one chromosome,
while the other carried an A-->G transition 96 bp upstream of exon 7 of the
telSMN gene, a potential disease-causing mutation in these patients.
PMID- 10686496
TI - Allelic frequencies of FBN1 gene polymorphisms and genetic analysis of italian
families with Marfan syndrome.
AB - The fibrillin gene (FBN1) is the disease locus for Marfan syndrome. This disorder
shows a high degree of clinical and allelic heterogeneity. Direct mutation
screening has proven difficult and inefficient and at present cannot be utilized
for routine analysis. In familial cases linkage analysis represents a useful tool
for molecular diagnosis. We have determined the allelic frequencies of 5
polymorphic markers within the FBN1 locus in the Italian population and have
successfully employed them for prenatal diagnosis and resolution of clinically
equivocal cases.
PMID- 10686497
TI - Search for coeliac disease susceptibility loci on 7q11.23 candidate region:
absence of association with the ELN17 microsatellite marker.
AB - The involvement of HLA genes in the susceptibility to coeliac disease (CD) has
been well documented and represents the only consistently observed genetic
feature of this multifactorial disease. In the present study, the search for new
susceptibility genes has been devoted to a candidate region suggested by the
association of CD with Williams syndrome (WS). This genetic disorder is due to a
deletion in the 7q11.23 region that includes the elastin (ELN) gene. An increased
prevalence of CD in WS patients has been previously reported and a case of CD-WS
is also described in the present study. We used the ELN17 microsatellite marker
mapped within the ELN gene to look for a possible contribution of this region to
the susceptibility to CD. The analysis of 74 Italian CD families provided no
evidence of association with the ELN17 marker.
PMID- 10686498
TI - Testing mode of inheritance of a candidate mutation at a quantitative trait
locus.
AB - Here is presented an approach to testing whether the effect of a candidate gene
on a quantitative trait is dominant and for testing whether the effect is
recessive. The approach uses parental genotype information in nuclear families to
adjust for bias due to population admixture. The approach is applicable
regardless of the nature of the sampling. The results of an application of the
methods to a candidate mutation for diabetic nephropathy are used for
illustration.
PMID- 10686499
TI - Allelic affinities between the F13A common gene products inferred by the analysis
of an (AAAG)n STR polymorphism within the 5' untranslated region.
AB - Factor XIII a subunit (F13A) is the last enzyme in the blood coagulation cascade.
It is characterized by extensive genetic polymorphism defined by 4 common
alleles, F13A*1A, 1B, 2A and 2B and a few rare variants, some responsible for
severe coagulation deficiencies. In order to infer the evolutionary affinities
between the common F13A alleles we have applied PCR techniques to study, in a
Northern Portuguese sample, a short tandem repeat polymorphism located within the
5' untranslated region of the F13A gene. The analysis of the molecular
heterogeneity within the F13A gene products revealed that the four biochemical
variants shared very similar, truncated, distributions of STR alleles and showed
no signs of predominant haplotypic associations. These findings seem to support
both the inferences that intragenic recombination played an important role in the
generation of molecular diversity within each of the four main F13A alleles and
that all the four F13A alleles must be rather old. Molecular heterogeneity levels
allowed the identification of 1B as the oldest F13A allelic state, and 2A as the
most recently generated allele, but were not different enough to accurately track
the divergence of alleles 1A and 2B. However, additional analysis of linkage
disequilibrium patterns indicates that 1B-->2B-->1A-->2A is the most likely
evolutionary order of appearance of F13A main protein alleles, confirming and
extending a previous hypothetical model inferred from their molecular features.
PMID- 10686500
TI - A note on a conditional-likelihood approach for family-based association studies
of candidate genes.
AB - The family-based association study design is a variation of the case-control
study design, where unaffected family members instead of unrelated subjects are
sampled as controls. This variation is useful in assessing the effects of
candidate genes on disease, because it avoids false associations caused by
admixture of populations. A complication of this design is that because of an
inherited genotypic correlation among family members, the genotypic distributions
between cases and relative controls may be distorted by the ascertainment
criteria of families, which could involve not only cases and relative controls,
but also other relatives. Analyzing such data naively may lead to biased
estimates of relative risk. In this note, we will discuss the consistency of a
conditional-likelihood approach. We show analytically that maximum conditional
likelihood estimators are consistent for the true relative risks, if genotypes
for family members are exchangeable under the sampling process, for example,
sibling clusters. Besides being straightforward conceptually and computationally,
this approach is robust to ascertainment bias and naturally accommodates genetic
heterogeneity across families.
PMID- 10686501
TI - Prenatal determination of a variable number of tandem repeats in intron 40 of the
von Willebrand factor gene from maternal peripheral blood using the polymerase
chain reaction.
AB - To determine a fetal variable number of tandem repeats (VNTR) without using fetal
tissues, we amplified the whole VNTR region in intron 40 of the von Willebrand
factor gene from maternal peripheral blood by the polymerase chain reaction and
then separated the amplified fragments by a nonhydratable polyacrylamide gel with
an electrolyte gradient. After water elution from the gel, each preliminary
product was amplified for the second time and then digested by Alu I restriction
endonuclease. Then the VNTR was examined using a hydratable polyacrylamide gel
with an electrolyte gradient. We successfully identified the fetal VNTR from 6
cases of 10 maternal peripheral blood samples and 2 cases of 6 maternal blood
samples after parturition. This study might offer a theoretical basis for the
noninvasive diagnosis of genetic disorders and identification of disputed
paternity with common primers.
PMID- 10686502
TI - Linkage analysis for diseases with variable age of onset.
AB - We present a method for the multivariate linkage analysis of the age of onset of
a disease. The approach allows the incorporation of covariates for the study of
gene by environment interactions. It is applicable to general pedigrees. The
likelihood of the data is expressed as a function of the number of alleles
identical by descent at a marker, the censored ages of onset and disease status,
and environmental exposures. In a simulation study, we compare the power to
detect linkage under different sampling schemes for either a dominant or
recessive trait when approximately 10% of individuals are gene carriers. The
majority of the linkage information from a sample of randomly selected sib pairs
was retained when the analyses were limited to sibships with one sibling having
early-onset disease (<59 years old). Incorporating parental phenotypes could
improve the power to detect the gene. When the sample consists of affected sib
pairs (ASPs) having variable age of onset, the likelihood ratio (LR) test had
higher power than the means (t(2)) test for detecting a locus with a large
genetic relative risk (R(g) = 20). However, the power of the two tests was
similar when ASPs are selected so that the proband has an early onset of disease.
Lastly, the LR test had more power than the t(2) test to detect linkage in the
presence of gene by environment interactions.
PMID- 10686503
TI - Genetic and environmental factors contributing to the onset of allergic
disorders.
AB - Evidence has been accumulated to suggest that allergen-reactive Th2 cells play a
triggering role in the activation and/or recruitment of IgE antibody-producing B
cells, mast cells and eosinophils, the cellular triad involved in allergic
inflammation. Recently, chemokines and chemokine receptors involved in such Th2
type response have been also defined. Th2 cells represent the polarized arm of
the effector-specific responses that contribute to the protection against
gastrointestinal nematodes and act as regulatory cells for chronic and/or
excessive Th1-mediated responses. Th2 cells are generated from precursor naive Th
cells when they encounter the specific antigen in an IL-4-containing
microenvironment. The question of how these Th2 cells are selected in atopic
patients is also unclear. Both the nature of the T cell receptor signalling
provided by the allergen peptide ligand and a disregulation of IL-4 production
likely concur to determine the Th2 profile of allergen-specific Th cells, but the
genetic unbalanced IL-4 production is certainly overwhelming. Some gene products
selectively expressed in Th2 cells or selectively controlling the expression of
IL-4 have recently been described. These findings allow to suggest that the
upregulation of genes controlling IL-4 expression and/or abnormalities of
regulatory mechanisms of Th2 development and/or function may be responsible for
Th2 responses against allergens in atopic people. The increasing prevalence of
allergy in developed countries suggests that environmental factors acting either
before or after birth also contribute to regulate the development of Th2 cells
and/or their function. The reduction of infectious diseases in early life due to
increasing vaccinations, antimicrobial treatments as well as changed lifestyle
are certainly important in influencing the individual outcome in the Th response
to ubiquitous allergens. Moreover, the recent evidence that bacterial DNA or
oligodeoxynucleotides containing unmethylated 'CpG motifs' promote the
development of Th1 cells via the production of immunomodulatory cytokines (namely
IL-12, IL-18 and IFNs) by professional antigen-presenting cells confirms previous
epidemiological data. The new insight into the pathophysiology of T cell
responses in atopic diseases provides exciting opportunities for the development
of novel immunotherapeutic strategies.
PMID- 10686504
TI - Characterization of T cell subpopulations involved in the pathogenesis of asthma
and allergic diseases.
AB - Allergic asthma is a complex and heterogeneous disease which is characterized by
intermittent reversible airway obstruction, chronic inflammation of the airways,
bronchial hyperreactivity and an infiltration of lymphocytes and eosinophils into
the airway submucosa. Animal models and clinical studies in humans have indicated
an important role for T helper type 2 lymphocytes, producing IL-4, IL-5 and IL
13, in the pathogenesis of this disorder. However, although IL-4 and IL-13 have
strong anti-inflammatory properties, the physiologic anti-inflammatory Th2
response does not seem to be operational in allergic asthma. Moreover, the
induction of a Th1 response seems to aggravate, rather than ameliorate, its
inflammatory character. This article will focus on the involvement of T
lymphocyte subpopulations in the pathogenesis of allergic asthma and allergic
diseases. In addition, a potential role of the subpopulation(s) of T regulatory
cells in the induction and/or maintaince of the disease process will be
discussed.
PMID- 10686505
TI - Identification of sunflower seed IgE-binding proteins.
AB - BACKGROUND: Sunflower seed can cause severe anaphylactic reactions in some
susceptible individuals. It is conceivable that the 2S sunflower seed protein is
an allergen based on its high degree of homology (34%) with the allergenic mature
2S albumin protein of the Brazil nut. The first step in determining the
allergenicity of sunflower seed proteins is to identify IgE-binding proteins.
METHODS: Sera from sunflower seed-sensitive individuals were evaluated by
radioallergosorbent test (RAST), isoelectric focusing (IEF) and sodium dodecyl
sulfate-polyacrylamide gel electrophoresis immunoblotting with sunflower seed
proteins. RESULTS: Positive RAST scores (>2) were observed in 3 individuals and
immunoblotting demonstrated IgE-binding to 2-7 distinct proteins ranging in size
from 10 to 50 kD. Two out of 3 sera recognized two proteins between 16 and 17 kD.
The lower molecular weight protein (16 kD) approximates to the prepo region of
the precursor methionine-rich 2S albumin protein found in sunflower seed (SFA
8/SSA). IEF followed by immunoblotting demonstrated several IgE-binding proteins,
including two proteins with isoelectric points of 5.97 and 5.3, respectively,
which are consistent with the mature and immature forms of the SFA-8/SSA region.
CONCLUSIONS: Sunflower seed contains several IgE-binding proteins, including
regions of the high-methionine 2S albumin SFA-8/SSA.
PMID- 10686506
TI - The effect of antigen stimulation on alpha(4), beta(1) and beta(7) chain integrin
expression and function in CD4+ cells.
AB - BACKGROUND: The alpha(4) integrin, as alpha(4)beta(1) (VLA-4) or alpha(4)beta(7),
is critical for T cell migration and proliferation, although its functional
modulation remains poorly understood. We hypothesized that increased receptor
density, based on new receptor chain synthesis, was one such mechanism. We
examined the surface receptor density of the alpha(4) and beta(1) chains on
CD4+CD45RO+ cells, and the mRNA expression of these and the beta(7) chain in
response to allergen and nonallergen antigen stimulation. METHODS: Flow
cytometric analyses for CD49d, CD29, and CD45RO were performed on T cell lines
specific for timothy, tetanus, and Candida from atopic and nonatopic donors. RNA
was extracted from cells sorted to select CD4+/CD49d-positive cells before and
after stimulation. Equivalent amounts of cDNA for beta-actin, alpha(4), beta(1)
and beta(7) were used in PCR, and the products were quantified using
phosphoimaging. RESULTS: CD49d expression is heterogeneous on T cell lines and is
upregulated by antigen stimulation on CD4+ T cells. The surface expression on
CD4+CD45RO+ timothy allergen or tetanus toxoid T cell lines is at least double
that found on CD45RO- cells. Antigen stimulation upregulated CD49d expression on
the CD4+CD45RO+ subpopulation of both cell lines although it was not as
significant as in the case of all CD4+ T cells. CD29 surface expression behaves
similarly. Candida had no effect on CD49d or CD29. Messenger RNA expression for
the alpha(4) chain (CD49d) is significantly upregulated 48 h following the
addition of timothy or tetanus. beta(7) chain expression also rises significantly
on both cell lines. beta(1) chain expression increases, but not significantly.
CONCLUSIONS: The surface expression of the CD49d is heterogeneous and much higher
on CD4+CD45RO+ cells than on CD4+RO- T cells. The CD49d integrin chain on CD4+ T
cells is upregulated following antigen exposure. However, the CD4+CD45RO+
subpopulation is only partially responsible for this increase suggesting other T
cells to have this receptor expression upregulated. CD29 expression behaves
similarly. Messenger RNA expression increases coordinately for alpha(4), beta(7),
and not significantly for beta(1) in these cells. These observations provide a
potential mechanism for the selective accumulation of T cells at sites of
inflammation, and suggest an important point of intervention for allergic and
inflammatory disease.
PMID- 10686507
TI - Effect of Ca(2+) ATPase inhibitors on MCP-1 release from bone marrow-derived mast
cells and the involvement of p38 MAP kinase activation.
AB - The effect of two Ca(2+) ATPase inhibitors, cyclopiazonic acid (CPA) and 2,5-di
(tert-butyl)-1,4-hydroquinone (DTBHQ), on the release of MCP-1 from bone marrow
derived mast cells (BMMCs) were investigated. CPA and DTBHQ increased the
intracellular free Ca(2+) concentration ([Ca(2+)](i)) and induced MCP-1 release
in a dose-dependent manner. These Ca(2+) ATPase inhibitors induced MCP-1 release
in the absence of phorbol ester, in contrast to their induction of TNF-alpha. MCP
1 release reached a maximum at 6-9 h. It was inhibited by treatment with
actinomycin D, the immunosuppressant cyclosporin A, and the cytosolic Ca(2+)
chelator BAPTA-AM. Furthermore, RT-PCR showed a time-dependent increase of MCP-1
mRNA. Thus MCP-1 release seems to depend on Ca(2+)-dependent transcriptional
activation. MCP-1 release was dose-dependently inhibited by the p38 MAP kinase
inhibitor SB202190, but not by the p44/42 MAP kinase inhibitor PD98059.
Therefore, transcriptional activation of MCP-1 production and its release seem to
be dependent on the nuclear factor of activated T cells and p38 MAP kinase
activation. This is the first report to show the regulation of MCP-1 production
in BMMCs.
PMID- 10686508
TI - Sodium salicylate-induced apoptosis of human peripheral blood eosinophils is
independent of the activation of c-Jun N-terminal kinase and p38 mitogen
activated protein kinase.
AB - BACKGROUND: It has been shown that the inhibition of eosinophilic apoptosis is an
important mechanism for the development of blood and tissue eosinophilia in
allergic diseases. Considerable attention has recently been focused on the role
played by different intracellular kinase cascades in the control of apoptosis. In
the present study, we investigated the effect of sodium salicylate (NaSal), a
nonsteroidal anti-inflammatory drug, on mitogen-activated protein kinases (MAPK)
and apoptosis of human eosinophils. METHODS: Human blood eosinophils were
purified from buffy coat. NaSal-induced apoptosis of eosinophils was assessed by
morphological changes and Annexin-V binding assay. Changes of MAPK activity upon
treatment with NaSal were measured by kinase activity assay and Western blot.
RESULTS: NaSal could induce apoptosis of human blood eosinophils in a dose- and
time-dependent manner. It could also activate c-Jun N-terminal kinase (JNK) and
p38 MAPK but not extracellular signal-regulated protein kinase (ERK) activity
within 1 h. Pretreatment of eosinophils with p38 MAPK and JNK anti-sense (AS)
phosphorothioate oligodeoxynucleotides (ODN) or specific p38 MAPK inhibitor SB
203580 did not have any significant effect on NaSal-induced apoptosis. However,
ERK AS ODNs could trigger the apoptosis of normal eosinophils. CONCLUSION: There
is no direct relationship between the activation of JNK and p38 MAPK pathways and
NaSal-induced apoptosis in human peripheral blood eosinophils.
PMID- 10686509
TI - Neurokinin-1 receptor antagonist inhibits short-term sulfuric-acid-induced airway
hyperresponsiveness in sensitized guinea pigs.
AB - BACKGROUND: Tachykinins are involved in the development of bronchial inflammation
and airway hyperresponsiveness (AHR); however, the role of the neurokinin-1
(NK(1)) receptor in acid-aerosol-induced bronchial impairment in asthmatic
patients remains controversial. METHODS: To investigate the effects on the NK(1)
receptor antagonist FK888 the neurokinin-2 (NK(2)) receptor antagonist SR48968 on
sulfuric-acid (H(2)SO(4))-induced AHR in guinea pigs, specific airways resistance
(sRaw) and airways responsiveness to methacholine (MCh) were measured before and
after 6 h of exposure to H(2)SO(4) aerosol (pH 1.7, 82 mg/m(3)) in ovalbumin
sensitized guinea pigs. RESULTS: Airway responsiveness to MCh significantly
increased (p<0. 05) after the exposure, however sRaw did not. Treatment with
FK888 significantly inhibited (p<0.05) H(2)SO(4)-induced AHR in a dose-dependent
manner, as did SR48968. CONCLUSIONS: These results suggest that not only NK(2)
but also NK(1) receptors might have important roles in the development of acid
aerosol-induced AHR.
PMID- 10686510
TI - Sequential development of airway hyperresponsiveness and acute airway obstruction
in a mouse model of allergic inflammation.
AB - BACKGROUND: Mouse models have been established mirroring key features of human
bronchial asthma including airway hyperresponsiveness (AHR). Acute airway
obstruction in response to an allergen challenge, however, remains to be
demonstrated in these models. OBJECTIVE: A mouse model of allergic lung
inflammation was employed to analyze the development of specific (allergen
induced) and nonspecific (methacholine-induced) airway obstruction. METHODS: Mice
were sensitized to ovalbumin (OVA) and challenged with OVA aerosol twice each
week during four weeks. Changes in lung functions were determined by noninvasive
head-out body plethysmography. The development of acute airway obstruction after
OVA challenge and AHR after methacholine aerosol application were assessed by a
decrease in the mid-expiratory flow rate (EF(50)). RESULTS: Two airway challenges
were sufficient to induce AHR (5.7 vs. 15 mg/ml methacholine). Further OVA
challenges reduced the baseline EF(50) from 1.85 to 1.20 ml/s (4th week) and
induced acute airway obstruction. The OVA-induced obstruction was maximal in the
4th week (EF(50) = 0.91 ml/s). CONCLUSION: The development of acute airway
obstruction in allergen-sensitized mice was demonstrated by means of head-out
body plethysmography. In our model, AHR was observed before the development of
airway obstruction.
PMID- 10686511
TI - Characterization of tissue outgrowth developed in vitro in patients with
rheumatoid arthritis: involvement of T cells in the development of tissue
outgrowth.
AB - BACKGROUND: The aim of this study was to analyze cellular and cytokine
interactions governing the development of synovial tissue outgrowth in patients
with rheumatoid arthritis (RA). METHODS: A single-cell suspension of dissociated
synovial tissues of RA patients was cultured for a long period to develop tissue
outgrowth. The resulting tissue outgrowth was characterized by
immunohistochemical staining and ELISA. RESULTS: The tissue outgrowth developed
in vitro included various cell types, such as macrophage-like synovial cells,
fibroblast-like synovial cells and lymphocytes. Even after prolonged cultivation,
synovial cells devoid of infiltrating T lymphocytes did not form tissue
outgrowth. The outgrowth contained CD3+ cells, LeuM3 (CD14)+ cells and HLA-DR+
cells. The T cells expressed lymphocyte function-associated antigen (LFA)-1 and
CD2, and the synovial cells expressed intracellular adhesion molecule (ICAM)-1
and LFA-3, suggesting possible interactions via LFA-1/ICAM-1 and CD2/LFA-3.
Production of T-cell derived IFN-gamma and IL-17 and synovial-cell-derived
fibroblast growth factor (FGF)-1 and IL-15 was confirmed in the tissue outgrowth
as well as in RA synovial tissue. These cell types stimulate each other by
secreting cytokines, leading to the secretion of proinflammatory cytokines and
matrix metalloproteinase (MMP)-1 by the tissue outgrowth and proliferation of
both lymphocytes and synovial cells. CONCLUSION: This study emphasizes the
importance of cellular interactions between T cells and synovial cells, via
adhesion molecules and the secretion of cytokines with stimulatory activity
towards other cell types, for the hyperactivity of RA synovial cells.
PMID- 10686512
TI - Immunogenicity of neutralizing epitopes on multiple-epitope vaccines against HIV
1.
AB - Based on our hypothesis that epitope vaccine may be a new strategy to induce high
levels of neutralization antibodies against HIV-1, we prepared multiple-epitope
vaccines using three neutralizing epitopes (GPGRAFY, RILAVERYLKD and ELDKWA) of
HIV-1 gp160, and characterized their immunogenicity. Peptide 1 [C-G-(ELDKWA
GPGRAFY)(2)-K] and peptide 2 (CG-GPGRAFY-ELDKWA-G-RILAVERYLKD) were synthesized
and conjugated with carrier protein bovine serum albumin (BSA). After vaccination
antibody responses to these immunogens were induced and evaluated by ELISA. The C
G-(ELDKWA-GPGRAFY)(2)-K-BSA (BSA: carrier protein) multiple-epitope vaccine
induced a strong antibody response to the C-G-(ELDKWA-GPGRAFY)(2)-K peptide
(antibody titer: 1:25,600) and C-(ELDKWAG)(4) peptide (antibody titer: 1:12,800),
but a weak antibody response to the C-(GPCGRAFY)(4) peptide. The CG-GPGRAFY
ELDKWA-G-RILAVERYLKD-K-BSA (BSA: carrier protein) multiple-epitope vaccine also
induced strong antibody response to the CG-GPGRAFY-ELDKWA-G-RILAVERYLKD-K peptide
(antibody titer: 1:25, 600) and C-(ELLDKWAG)(4) peptide (antibody titer:
1:6,400), a very strong response to C-(RIVALVERYLKD-G)(2)-K peptide (dilution:
1:102, 400), and a very weak response to the C-(GPGRAFY)(4) peptide (dilution:
1:400) in mice. Both antisera induced by both multiple-epitope vaccines
interacted with the recombinant soluble gp41 (rgp41), but did not bind two
control peptides. In comparison with both epitope vaccines, the rgp160 subunit
vaccine could induce weak epitope-specific antibody response to these three
epitopes on the three epitope peptides and V3, N-domain and C-domain peptides
(dilution: 1:400-1:1,600). These results indicate that both multiple-epitope
vaccines could induce high levels of antibodies to both neutralizing epitopes
RILAVERYLKD and ELDKWA, while the GPGRAFY epitope on both vaccines appeared to
have weak immunogenicity. Both multiple-epitope vaccines showed significant
potency on inducing high levels of epitope-specific neutralization antibodies in
comparison with rgp160 subunit vaccine.
PMID- 10686513
TI - A simple advice for the prevention of pollen-induced allergic rhinitis.
PMID- 10686514
TI - Castration of sexually immature rats affects sympathetic innervation of the adult
thymus.
AB - It has been hypothesized that maturational processes within the hypothalamo
pituitary-gonadal (HPG) axis and thymus are reciprocally regulated via neural
pathways. To test this hypothesis, in the thymi of adult rats orchidectomized
(ORX) at age of 1 (ORX-1), 7 (ORX-7) and 30 days (ORX-30): (i) noradrenaline
(NA), dopamine (DA) and serotonin (5-HT) contents and acetylcholinesterase (AChE)
activity were measured and (ii) the distribution of monoamine- and AChE
containing nerves and cells was examined by a sucrose phosphate glyoxylic acid
(SPG) method and enzyme histochemistry, respectively. In all groups of ORX rats,
the thymus weight was significantly increased over that in sham-ORX control rats.
In the ORX-1 rats, the increase in the thymus weight was accompanied by a
proportional increase in the content of both catecholamines and 5-HT;
consequently the concentration of each of them remained unaltered. In these
animals, the density of both SPG-stained thymus nerve fibers and cells also
remained unchanged. In the ORX-7 rats, the rise in the thymus weight was followed
by a proportional increase in the content of all monoamines, except for NA which
was reduced. Therefore, in these rats neither the thymus concentrations of DA nor
that of 5-HT differed from controls, while the concentration of NA was
significantly decreased. The reduction in both NA content and concentration
reflected a diminished density of SPG-positive nerve profiles. In the ORX-30
rats, the increase in thymus weight was neither paralleled by a proportional
increase in the DA content nor in 5-HT, while the content of NA was decreased.
Thus, in their thymi the concentration of both NA and DA, as well as that of 5
HT, were significantly reduced. In parallel with these changes, a decreased
density of thymic SPG-positive nerve fibers and cells was found. In all ORX rats,
the pattern of intrathymic distribution of SPG-positive fibers and cells remained
unchanged. Orchidectomy affected neither the activity of AChE (expressed per gram
of tissue) nor the density of AChE-positive nerves and cells in the thymus. As
the changes in the density of adrenergic nerve fibers in the thymus from ORX rats
were not followed by similar alterations in the density of AChE-containing nerve
fibers, it does not seem likely that NA and AChE are colocalized in the thymus
nerve fibers. The results also suggest that there is a critical period during
ontogenesis when changes within the HPG axis evoked by orchidectomy can affect
the sympathetic nerve input to the rat thymus and therefore, most likely,
development and function of the organ.
PMID- 10686515
TI - Suppression of lymphocyte mitogenesis by tamoxifen: studies on protein kinase C,
calmodulin and calcium.
AB - The effect of tamoxifen (TX; 1.0 microM) on the mitogenic response of rat
lymphocytes was compared with the effect of drugs that are known to act on
protein kinase C (PKC), calmodulin (CM), and calcium (Ca(2+)). The calcium
ionophore A23187 (0.2 microM) was mitogenic on its own which was not influenced
by TX. The agents modulating PKC or CM (phorbol-myristate-13-acetate; R24571,
chlorpromazine) influenced mitogenesis differently than did TX. General
inhibition of lymphocyte proliferation was seen with the Ca(2+) antagonist agents
(EGTA, TMB-8) as with TX. The antiproliferative effect of TX was partially
reversed by the increase of Ca(2+) in the culture medium when T cell mitogens
were used, but not in the case of lipid A, a B lymphocyte mitogen. However, the
concanavalin A-induced Ca(2+) influx was further elevated by TX which differed
from the effect of the Ca(2+) channel-blocking agent verapamil. The results
suggest that TX resets the threshold stimulus necessary for mitogenesis and is
completely reversible.
PMID- 10686516
TI - Effect of interleukin-6 and tumor necrosis factor-alpha on GABA release from
mediobasal hypothalamus and posterior pituitary.
AB - The release of cytokines during infection, inflammation and stress induces brain
mediated responses, including alterations of neuroendocrine functions. We
examined the effect of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF
alpha) on release of gamma-aminobutyric acid (GABA) from mediobasal hypothalamic
(MBH) explants and posterior pituitaries (PP) of male rats. IL-6 (10 ng/ml) did
not modify basal GABA release from MBH and PP, but significantly increased GABA
release under depolarizing conditions (40 mM K(+)). This effect was abolished by
incubation of the tissue with indomethacin, an inhibitor of cyclooxygenase
activity, indicating that prostaglandins could mediate the stimulation of GABA
release induced by IL-6. On the contrary, TNF-alpha (50 ng/ml) significantly
decreased K(+)-evoked GABA release from both MBH and PP. This inhibitory effect
was not modified by indomethacin. Neither IL-6 nor TNF-alpha affected nitric
oxide synthesis, as measured by [(14)C]citrulline production. The current results
indicate that IL-6 stimulates GABA release from both hypothalamus and posterior
pituitary by a mechanism mediated by prostaglandins. On the contrary, TNF-alpha
inhibits GABA release from both tissues. These results suggest the possibility
that GABAergic activity in the hypothalamic-pituitary axis could be involved in
neuroendocrine responses to cytokines.
PMID- 10686517
TI - Time-dependent effect of cyclosporine on mitogenic responses and lymphocyte
subset populations in rat spleen and submaxillary lymph nodes.
AB - Lipopolysaccharide (LPS)- and concanavalin A (ConA)-induced proliferation and T
lymphocyte subsets were measured in spleen and submaxillary lymph nodes of male
rats injected with cyclosporine (5 mg/kg s.c. for 5 days, at 12.00 or 24.00 h;
animals kept under light from 08.00 to 20.00 h daily). One hour before the third
injection, Freund's complete adjuvant or its vehicle was administered. A
suppressive effect of cyclosporine on the mitogenic action of LPS was seen in the
spleen of rats injected with cyclosporine at noon whereas the effect of ConA
remained unaffected. CD4+, CD8+ and CD4+-CD8+ cells decreased in spleen and lymph
nodes of Freund's adjuvant-injected rats only with cyclosporine given at noon.
The results further support occurrence of time-of-day-dependent effects of
cyclosporine on lymphocyte subsets and proliferation.
PMID- 10686518
TI - Time of day-dependent effects of thyroliberin and thyrotropin on thymocyte
proliferation in rats.
AB - Our earlier studies have shown that thyroliberin (TRH) as well as thyrotropin
(TSH) enhanced thymus cell proliferation. The aim of the present study was to
investigate whether the effects of TRH and TSH on thymocyte proliferation depend
on time of day. A single subcutaneous injection of TRH (25 microgram/animal) or
TSH (3 IU/animal) was made at 9:00 h (1 h after light onset) or at 18:00 h (10 h
after light onset) in 3-month-old male Wistar rats. The animals were killed 24 h
later. The proliferation of thymocytes was assessed by incorporation of
bromodeoxyuridine into cell nuclei. Thymocyte proliferation was significantly
increased by TSH administration at 9:00 h, whereas treatment given at 18:00 h was
ineffective. TRH enhanced the proliferation when injected at 9:00 h, but had an
inhibitory effect when administered at 18:00 h. These data indicate that the
effects of TRH and TSH on thymocyte proliferation are dependent on time of day.
PMID- 10686519
TI - Metabolic, neuroendocrine and immune functions in basal conditions and during the
acute-phase response to endotoxic shock in undernourished rats.
AB - Chronic malnutrition is one of the most important causes of several metabolic,
immune and neuroendocrine dysfunctions. The aim of the present study was to
determine the influence of chronic food restriction on basal neuroendocrine,
immune and adipocyte functions and during the acute-phase response to endotoxic
shock in female rats. The effect of refeeding of undernourished rats on the above
mentioned functions was also investigated. For these purposes, plasma total
protein, glucose, triglycerides, ACTH, corticosterone, tumor necrosis factor
alpha (TNF) and leptin (LEP) levels were determined in basal condition and 2 h
after endotoxin (LPS; 180 microgram/kg body weight, i.p.) administration in 3
different groups: (1) well-nourished (WN) controls; (2) undernourished (UN) rats
as a consequence of chronic food restriction, and (3) UN rats re-fed to
restoration of their body weights in the WN rat range. The results indicate that
UN rats, in comparison with WN controls, developed an arrest in body weight gain
as well as in basal hypoglycemia, hypotriglyceridemia, hypoleptinemia,
hypercorticosteronemia and enhanced adrenal glucocorticoid content; however, no
changes in basal total protein, ACTH and TNF plasma levels and in anterior
pituitary ACTH concentrations were found. When endotoxic shock was induced, the
LPS-induced hypoglycemia developed in WN rats was abolished in UN animals, and
both ACTH and TNF plasma concentrations after endotoxin, albeit significantly (p
< 0.05) higher than the respective basal values, were significantly (p < 0.05)
lower in UN than in WN control rats. Despite the high basal plasma corticosterone
concentration in UN vs. WN rats, the LPS-induced glucocorticoid release was
similar in WN and UN rats. Additionally, LPS treatment did not modify basal
plasma LEP levels, regardless of the group. Interestingly, UN rats fed ad libitum
for 15 days restored their body weight to WN rat range values, and the various
metabolic dysfunctions seen in UN rats in both basal and post-LPS conditions were
fully normalized. Our results clearly indicate that chronic undernutrition not
only affects, as earlier described, reproductive function but also metabolic,
neuroendocrine, immune and adipocyte functions, and that the effects induced by
undernutrition can be fully reversed after recovery of normal body weight. The
present study strongly supports the involvement of the metabolic status in the
effectiveness of the defense mechanisms developed in patients in inflammatory
stress conditions.
PMID- 10686520
TI - Caffeic acid phenethyl ester induces leukocyte apoptosis, modulates nuclear
factor-kappa B and suppresses acute inflammation.
AB - Nuclear factor kappa-B (NF-kappaB) is a heterodimeric transcription factor with a
pivotal role in orchestrating immune and inflammatory processes. Inflammatory
cytokines and prostanoids activate NF-kappaB, which, in turn, stimulates
expression of cytokines, proteases, adhesion molecules and other inflammatory
mediators. Caffeic acid phenethyl ester (CAPE) is a compound that modulates
nuclear binding of the NF-kappaB p65 subunit (RelA). To determine whether CAPE
decreases the viability of cells participating in host defense, we first tested
its in vitro effect on a glucocorticoid-sensitive and -resistant cell line of
lymphoid origin. CAPE induced apoptotic cell death in a dose-dependent fashion
and to a similar extent in both cell lines. Furthermore, a low concentration of
CAPE decreased the LD(50) of dexamethasone by 3- to 5-fold. Since therapeutic
induction of apoptosis of activated inflammatory cells holds the attraction of
destroying effector cells safely without secondary tissue damage, we examined the
effects of CAPE in a rat model of carrageenin-induced subcutaneous inflammation.
Local administration of CAPE resulted in increased leukocyte apoptosis and marked
reduction in exudate leukocyte, neutrophil and monocyte concentrations at the
inflammatory site. CAPE decreased expression of cytosolic IkappaBalpha and
increased nuclear translocation of p65. These findings may suggest that novel
anti-inflammatory therapies can be based upon activation of NF-kappaB-mediated
transcription of genes curbing the inflammatory response and that CAPE or its
analogs hold therapeutic promise.
PMID- 10686521
TI - Conditioned alterations of specific blood leukocyte subsets are reconditionable.
AB - Behavioral conditioning has the ability to produce changes in immune function.
However, it is unknown whether conditioned changes of immune function can be
recalled on multiple occasions. To address this issue we paired a novel saccharin
drinking solution with intraperitoneal cyclosporin A (CsA) injection in rats.
Saccharin re-presentation produced a reduction in splenocyte proliferation that
mirrored the effect of CsA. Such functional changes were paralleled by a
significant conditioned leukopenia in peripheral blood, which opposed the
leukocytosis induced by CsA. Using the conditioned leukopenia in blood as a
'diagnostic window' of conditioned immunosuppression, the maintenance of CsA
induced changes was investigated by examining blood samples collected repeatedly.
Experiments on the same group of animals over a period of 1 year showed that the
conditioned leukopenia was reproducible on multiple occasions by reimplementing
either the whole conditioning paradigm or reexposure to the saccharin solution
only. These results demonstrate that behaviorally conditioned alterations of
immune parameters are maintained in subsequent trials, indicating the potential
clinical feasibility of behavioral conditioning procedures.
PMID- 10686522
TI - CRH deficiency impairs but does not block pituitary-adrenal responses to diverse
stressors.
AB - We have previously observed significant, albeit decreased, corticosterone
responses to restraint stress in corticotropin releasing hormone (CRH)-deficient
(knockout, CRH KO) mice. Because different stressors have been shown to engage
different populations of hypophysiotropic neurons, we have used hypoglycemia and
hypovolemia to test whether CRH-independent pituitary-adrenal activation is
evoked by stimuli other than restraint. Insulin injection in fasted CRH KO mice
elicited increases in corticosterone that were markedly lower than those in wild
type but marginally significant relative to corresponding KO controls. Consistent
with impaired adrenocortical function, hypoglycemia-induced epinephrine secretion
was reduced in female CRH KO mice. Hypovolemia produced by retro-orbital bleeding
also significantly elevated corticosterone in CRH KO mice. In contrast to
significant stress-induced increases in corticotropin (ACTH) in wild-type mice,
those in CRH KO mice were slight, transient and difficult to detect without
frequent sampling. Restraint-induced interleukin-6 (IL-6) levels were similar
between wild-type and CRH KO mice, arguing against compensatory changes in IL-6
responses to restraint due to CRH deficiency. CRH infusion enhanced
adrenocortical responses to restraint independently of effects on basal
corticosterone levels, suggesting that pituitary-adrenal activity is augmented by
factors besides CRH during stress. We conclude that although stress-induced
pituitary-adrenal activity does not require acute increases in CRH, CRH is
required to support the normal amplitude of adrenocortical axis responsiveness to
other endocrine or neural factors during stress.
PMID- 10686523
TI - Potentiated response of corticotropin (ACTH) to repeated moderate hemorrhage
requires amygdalar neuronal processing.
AB - We examined the role of the amygdala in the potentiation of the corticotropin
(ACTH) response to a 10 mg/kg hemorrhage by a 1-hour episode of equivalent
hypovolemia done 24 h earlier. Unanesthetized rats were studied on the fourth
(D1) and fifth (D2) day after chronic implantation of arterial and venous
catheters. Immunocytochemistry for Fos protein indicated that neurons in the
central and medial nuclei of the caudal amygdala were activated by hemorrhage. We
then tested the effect of excitotoxic destruction of the neurons in these areas
by bilateral injections of ibotenic acid 10 days prior to catheter placement. In
rats that were hemorrhaged on both D1 and D2, the responses of ACTH and
corticosterone increased significantly from the first (H1) to the second
hemorrhage (H2) in a control group injected with saline (p < 0.05) and in
lesioned groups without bilateral damage of the Fos-responsive areas (p < 0.01).
In the group with bilateral damage to these sites, the responses to H1 and H2 did
not differ. Additional rats had H1 on D2 to control for the long-term effects of
the chronic cannulation. The responses of ACTH to H1 on either D1 or D2 did not
differ between the saline-injected controls and any of the lesioned groups. In
contrast, the response of ACTH to H2 on D2 in rats with bilateral damage of the
caudal amygdala was not significant and was less than the response of ACTH to H2
in both rats with unilateral damage of this area (p < 0.05) and those injected
with saline (p < 0.05). We conclude that bilateral neuronal processing within the
caudal amygdala is required for the potentiation of the response of ACTH to H2 by
H1.
PMID- 10686524
TI - Monensin and hypo-osmolar medium cause calcium-independent beta-endorphin
secretion from melanotropes.
AB - Monensin has been shown to cause nonexocytotic release of catecholamines from
adrenal medullary and PC12 cells. We examined the effect of monensin on peptide
secretion with cultured melanotropes from the rat pituitary as a model. 1 microM
monensin caused an immediate, transient increase in beta-endorphin secretion. The
effect was still seen in a calcium-free medium, but was totally abolished in a
sodium-free medium. Intracellular calcium concentration was measured with Fura 2:
no increase was observed during monensin stimulation. Hypo-osmolar medium
mimicked the effect of monensin, causing a 12-fold transient increase in beta
endorphin secretion. This effect was not abolished in either calcium-free or
sodium-free medium. No increase in the number of exocytotic figures captured by
tannic acid incubation was observed during 5 min of incubation with 1 microM
monensin or hypo-somolar medium. We thus show that monensin causes beta-endorphin
secretion from the melanotrope and that this effect is due to sodium influx and
resultant cell swelling. The calcium independency and lack of increase of
exocytotic figures suggest that swelling-induced secretion is nonexocytotic,
possibly via transient exocytotic pore opening.
PMID- 10686525
TI - Hyperinnervation during adrenal regeneration influences the rate of functional
recovery.
AB - The rat adrenal cortex has the uncommon ability to demonstrate morphological and
functional regeneration after injury-induced loss of cortical tissue. Peripheral
nerves are involved in tissue regeneration and healing after injury, implying
that nerves may also be involved in modulating the regeneration of the adrenal
cortex. Studies were initiated to assess changes in adrenal innervation during
cortical tissue regeneration subsequent to adrenal enucleation. Innervation of
regenerating adrenals was assessed from 3 to 62 days postenucleation by
immunohistofluorescent detection of neuronal markers for primary afferent,
preganglionic sympathetic, and postganglionic sympathetic fibers. The
regenerating adrenal contained few nerves at 3 days postenucleation, but became
differentially innervated, with extensive innervation by nerve fibers positive
for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH),
neuropeptide Y (NPY), and neuronal nitric oxide synthase (nNOS). In contrast,
there was only minimal innervation by nerve fibers positive for vasoactive
intestinal peptide. By 14 days postenucleation, the CGRP-, TH-, and NPY-positive
innervation included areas of hyperinnervation in the capsule, cortex, and
central inflammatory site of the regenerating gland. In addition, many chromaffin
cells were present at all time points postenucleation. Quantification of the
regenerating gland content of CGRP, norepinephrine, epinephrine, and nNOS
verified the immunohistofluorescent observations. The period of extensive
innervation correlated temporally with the time (3-30 days) during which the
regenerating glands recovered steroidogenic function. Moreover, splanchnic nerve
transection at the time of adrenal enucleation decreased the innervation by CGRP
positive and vesicular acetylcholine transporter-positive fibers and delayed
regeneration. These results support the hypothesis that adrenal innervation
modulates tissue regeneration and functional recovery of the enucleated adrenal
gland.
PMID- 10686526
TI - Far upstream sequences regulate the human prolactin promoter transcription.
AB - The human prolactin gene is mainly expressed in pituitary lactotrope cells, but
transcription from an alternative, far upstream promoter was detected in
lymphoid, placental and mammary cells. We describe the transcriptional activity
in rat pituitary cells of the complete region separating the two promoters, using
transient transfection experiments. A far upstream activating region was only
functional in combination with the prolactin promoter. DNaseI protection
experiments revealed, in addition to binding sites for the pituitary-specific
factor Pit-1, sites (e.g. SD1) for several ubiquitous factors and one lymphoid
specific factor (SD4). A single copy of the ubiquitous site SD1 or the lymphoid
specific site SD4 was unable to activate transcription of a heterologous promoter
in pituitary cells. However, SD1 activated transcription in nonpituitary cells
and SD4 was functional specifically in lymphoid cells. Five copies of a distal
site (D8) activated transcription in each cell type tested. Gel retardation
experiments show that this site binds the specific factor C/EBP in liver and a
distinct factor in other cell types. Our results suggest that different elements
within this large region direct specific expression from each promoter via a
complex interplay between cell-specific and ubiquitous transcription factors.
PMID- 10686527
TI - Pulsatile gonadotropin-releasing hormone (GnRH) secretion is an inherent function
of GnRH neurons, as revealed by the culture of medial olfactory placode obtained
from embryonic rats.
AB - To determine whether gonadotropin-releasing hormone (GnRH) neurons in culture
without the hypothalamus secrete GnRH in a pulsatile fashion, the nasal placode
(NAP) was obtained at day 13.5 of gestation and cultured by a roller tube method.
If the GnRH release occurs in a pulsatile fashion, it can be said that the pulse
generator of GnRH exists inherently in each cell or community of cells in the
culture. The concentration of GnRH in the NAP culture medium collected at 8-min
intervals for 160 min after 2- to 4-week cultures showed that GnRH release
occurred in a pulsatile fashion with a mean interpulse interval of 29.8 +/- 2.3
min (n = 9). When the NAP was cultured with tissues of the forebrain vesicle (n =
3) or the hypothalamus (n = 4), GnRH was also released in a pulsatile fashion
with similar intervals (27.3 +/- 1.0 min for the NAP+forebrain vesicle culture
and 36.0 +/- 6.3 min for the NAP+hypothalamus culture) as those in cultures
without brain tissues. It is concluded that pulsatile GnRH release is an inherent
function of GnRH neurons.
PMID- 10686528
TI - Influence of different serotonin receptor subtypes on growth hormone secretion.
AB - The role of serotonin (5-HT) in the regulation of growth hormone (GH) secretion
remains unclear due to the existence of many different receptors that mediate the
5-HT actions, and the lack of suitable specific agonist and antagonist drugs. In
the present work we have taken advantage of the recent development of new
selective 5-HT drugs in order to clarify the role played by different 5-HT
receptor types and subtypes on GH secretion. The experiments were carried out on
beagle dogs. GH-releasing hormone (GHRH) increased basal canine GH (cGH) levels
from 0.8 +/- 0.2 to 8.8 +/- 1.7 microg/l at 15 min. Administration of 5-HT(1D)
receptor agonist sumatriptan (SUM) induced a cGH peak at 30 min of 12.9 +/- 2.7
microg/l. The combined administration of GHRH plus SUM strikingly potentiated cGH
release with a peak of 36.9 +/- 6 microg/l at 30 min (p < 0.05). Pretreatment
with the muscarinic receptor antagonist atropine completely abolished the cGH
response to SUM, while the cholinergic agonist pyridostigmine (PYR) did not
modify this response (15.3 +/- 5 microg/l PYR plus SUM vs. SUM alone 12.9 +/- 2.
7 microg/l). On the other hand, administration of drugs with activity at 5
HT(2A/C) receptors showed a stimulatory role for the 5-HT(2C) receptor subtype,
since LY-53857 (antagonist 5-HT(2A/C)) and DOI agonist (5-HT(2A/C)) both modified
the GH response stimulated by GHRH (AUC 88.5 +/- 30.4 and 400 +/- 64.6 vs. 267.3
+/- 52.6 respectively), while ketanserin (antagonist 5-HT(2A)) did not modify
this response. The 5-HT(3) antagonist ICS-205-930 failed to modify either basal
or GHRH induced GH responses. In conclusion, our data show that 5-HT(1D)
receptors play a stimulatory role on GH secretion in the dog, possibly by acting
through a decrease in hypothalamic somatostatin release. Similarly, the 5-HT(2C)
receptor subtypes also appear to play a stimulatory role. However, 5-HT(2A) and 5
HT(3) receptors do not appear to be involved in the control of basal and GHRH
induced GH secretion.
PMID- 10686529
TI - How is Creutzfeldt-Jakob disease acquired?
AB - Creutzfeldt-Jakob disease (CJD) is one of several related disorders collectively
called prion diseases. These disorders affect man and animals and are now known
to be caused by the abnormal configuration of a naturally occurring protein,
PrP(c). By mechanisms still not well understood, this natural protein is
converted into a pathologic variant, PrP(sc). The disease is 'acquired'
spontaneously perhaps by posttranslational conversion of a PrP(c) into a PrP(sc)
population. This sporadic form of CJD has been reported worldwide with a
frequency of 1/million. Other modes of acquisition include the following:
ingestion of brain tissue from deceased victims through ritual cannibalism at
burial ceremonies formerly (and no longer) practiced by New Guinea Highlanders;
iatrogenically, through corneal transplants from infected donors, inoculation of
human growth hormone and gonadotropin prepared from infected human pituitary
glands; from inadequately sterilized depth electrodes introduced neurosurgically
into the brain during workups of patients with epilepsy, and applications of
infected dura mater in neurosurgical procedures. Most recently, an infected
bovine source (bovine spongiform encephalopathy) has been implicated and produces
a new variant of CJD. Clusters of CJD in families in some populations have been
recognized which are inherited in Mendelian fashion. These clusters are related
to mutations of the PRNP gene in specific codons (e.g. codon 200). Homozygosity
for these mutations increases the chances of manifesting the disease. Other
potential methods of acquisition, such as by blood transfusion, surgical sutures,
tonometers, consumption of hog brain or other organs and tissue, remain unproven.
PMID- 10686530
TI - Creutzfeldt-Jakob disease in a recipient of a dura mater graft processed in the
US: cause or coincidence?
AB - Iatrogenic Creutzfeldt-Jakob disease (CJD) has never been reported among
recipients of dura mater grafts processed in the US. We recently investigated a
report of such a case in a 72-year-old man with a typical clinical presentation
of CJD. We found no evidence of CJD in either the 34-year-old donor or in other,
proximal patients undergoing craniotomies. Although the graft may have caused the
illness, sporadic CJD is a more likely explanation, with the graft being
coincidental.
PMID- 10686531
TI - Regional and temporal variation in the incidence of multiple sclerosis in Finland
1979-1993.
AB - Previous surveys in Finland from the 1960s have documented an uneven geographic
distribution of multiple sclerosis (MS). In the present study, the incidence of
MS was studied during 1979-1993 in the western Vaasa and Seinajoki regions and in
southern Uusimaa. The overall difference between the western and southern regions
persisted; 8.7 per 100,000 in the western, and 5.1 per 100,000 in the southern
region. The incidence of 11.6 per 100,000 in Seinajoki was more than twofold
greater than the 5.2 per 100,000 incidence found in neighboring Vaasa. An
increasing incidence trend was observed for men in Seinajoki, and a decrease for
both sexes in Vaasa, while in Uusimaa the incidence remained stable for both
sexes. The different incidence trends could not be readily explained by
differences in case ascertainment but suggest the effect of environmental factors
that have modulated the incidence of MS during the 15-year study period.
PMID- 10686532
TI - Relationship of family history scores for stroke and hypertension to quantitative
measures of white-matter hyperintensities and stroke volume in elderly males.
AB - White-matter hyperintensities (WMHI) are frequently associated with
cerebrovascular risk factors in the elderly, particularly hypertension, and have
been interpreted as a subclinical form of ischemic brain damage. WMHI, clinical
stroke and blood pressures show significant genetic influences. The objective of
this study was to determine whether a relationship exists between family history
of stroke and/or hypertension in first degree relatives and WMHI in the elderly.
WMHI and stroke (CVA) volumes were quantified from brain MRI performed on 414
white, male twins born between 1917 and 1927 (average age 72.3 +/- 2.9 years).
WMHI, adjusted for age and head size, was significantly correlated with the
family history score (r = 0.21, p < 0.001). Dividing the family history scores
into quintiles revealed significant differences in WMHI by quintile mean (p <
0.05). Subjects in the highest quintile of family history score had the highest
mean WMHI. Recalculation of the family history score, by only counting relatives
reported to have had a clinical stroke as a positive event, revealed a
nonsignificant correlation with WMHI, but the correlation of the family history
score with MRI CVA volume was significant (p < 0.05). Stepwise multivariate
analysis including ApoE status, current smoking status, smoking packyear history,
Doppler ankle/arm blood pressure ratios, current and long term hypertensive
status and current systolic and diastolic pressures indicated that the
stroke/hypertension family history score was the single best predictor (p < 0.01)
of WMHI volumes. Family history was not an independent predictor of CVA volume.
PMID- 10686533
TI - Cost of illness of epilepsy in the US: comparison of patient-based and population
based estimates.
AB - PURPOSE: To analyze the direct medical costs associated with epilepsy in the US
using a cost-of-illness analysis that incorporates both a patient-based approach
and a population-based approach. METHODS: Patient-based or 'bottom-up' analysis
relied on information provided by a panel of experienced epilepsy clinicians to
determine the number and type of medical resources used by individuals with
epilepsy. Population-based or 'top-down' analysis relied on cost estimates from a
nationally representative sample in the 1987 National Medical Expenditure Survey.
RESULTS: The average annual cost per individual in the patient-based analysis was
$1,490. The average annual cost per individual in the population-based analysis
was $1,510 with average yearly costs per adult of $1,480 and $1,740 per child.
New cases of epilepsy are associated with costs of $362 million for the first
year of treatment; existing cases of epilepsy are estimated to cost the US nearly
$2 billion. CONCLUSIONS: The results of this study indicate incident cases are
more than twice as expensive as prevalent cases, and the need to properly care
for epilepsy patients is increasingly important in today's health care
environment, where the emphasis is on providing effective treatments while
simultaneously lowering the costs.
PMID- 10686534
TI - Patterns of outcome measurement in Parkinson's disease clinical trials.
AB - The study examines the pattern of use and clinimetric properties of clinical
endpoints used in randomized trials for Parkinson's disease (PD). Randomized drug
trials for PD were identified through a Medline search conducted from January
1966 until August 1998. The endpoints used in these trials were abstracted.
Reports examining the clinimetric properties of the disease-specific scales used
in these trials were also abstracted. Data regarding the consistency, accuracy,
discrimination and feasibility of scales used in at least 10% of trials were
determined. One hundred and thirty-seven articles met the inclusion criteria;
70.8% of trials used some clinical scale for PD as an endpoint. The Unified
Parkinson's Disease Rating Scale (UPDRS) was the most commonly used scale
(32.8%). Factors independently associated with the use of the UPDRS included: the
study location in the US, mean age of subjects over 62.7 years and publication
after 1994. The UPDRS was more thoroughly studied and superior in most
clinimetric domains compared to scales developed earlier. Few studies included
generic health status (2.9%) or cognitive measures (16.8%) as secondary
endpoints. There have been definite improvements in the area of disease-specific
measurement in PD trials since the introduction of the UPDRS. The results of
studies that used instruments with poor or unreported clinimetric properties
should be critically interpreted.
PMID- 10686535
TI - The cladribine trial in secondary progressive multiple sclerosis: A reanalysis.
AB - In a recent communication, Goodin [1] analyzes several clinical trials to point
out serious flaws in both design and interpretation that may invalidate the
conclusions that are drawn. We agree with Goodin [1] that the design of clinical
studies, particularly of a disease as complex as multiple sclerosis, is extremely
difficult. Indeed, a perfectly designed and executed clinical study is a goal
that is never achieved because of the problems inherent in providing care to
patients while attempting to evaluate a therapeutic modality. Specifically, in
the study of multiple sclerosis, none of the clinical trials of the use of
interferons could be considered fully satisfactory: blinding is actually
impossible because of the symptoms that are experienced by patients when they
receive active drug but not when they receive placebo. It is quite fashionable
and not at all difficult to find problems in the conduct of clinical studies;
indeed, if all clinical studies with flaws were discarded, there would be no
acceptable clinical studies.
PMID- 10686536
TI - Evolution of the carcinoembryonic antigen family. structures of CGM9, CGM11 and
pregnancy-specific glycoprotein promoters.
AB - Earlier studies have demonstrated that the genes of the human carcinoembryonic
antigen (CEA) family can be divided into three subgroups, the CEA subgroup (n =
12), the pregnancy-specific glycoprotein (PSG) subgroup (n = 11), and a third
subgroup (n = 6). To further characterize the CEA gene family, we have determined
the genomic structures of CGM9 and CGM11, analyzed the promoter regions of all
eleven PSGs, studied the CGM15-PSG13 intergenic region and the evolutionary
relationships beween the CEA family genes. CGM9, a typical CEA subgroup member,
was a pseudogene with the exon structure [5'UTR-L-L/N-TM-Cyt-3'UTR]. CGM11
contained a mixture of exons derived from CEA and PSG subgroup genes. The formula
of the CGM11 pseudogene was [5'UTR-L-L/N-C-3'UTR]. Thus both genes lacked the
IgC2-like domains typically found in CEA subfamily members. The upstream promoter
regions of all eleven PSGs were characterized. All PSG promoters lacked the
classical TATA and CCAAT elements, but had putative PEA3 box(es), CACCC box(es),
a RARE box, and poly (dG-dT) repeats of different lengths. Five PSGs also had an
SP1 site. The complete 10-kb intergenic region between CGM15 and PSG13 was
sequenced. Clusters of different types of repetitive sequences were seen. The
time of divergence of the CEA and PSG subfamilies was estimated to be 107.7 +/-
17.1 million years, or at about the time of human-rodent divergence. Models for
the evolution of CEA and PSG and the third family subgroup genes are proposed.
PMID- 10686537
TI - Evaluation of serum alkaline DNase activity in treatment monitoring of head and
neck cancer patients.
AB - Our previously published data on breast cancer suggest that serum alkaline DNase,
a known circulating tumour marker, can be used for treatment monitoring of cancer
patients. Serum alkaline DNase activities were analyzed in 215 untreated head and
neck cancer patients. The enzyme activity ranged from 0.17 to 97.97 IKU/l in
untreated cancer patients. Responders (n = 314) showed significantly elevated
activity of alkaline DNase as compared to untreated cancer patients (p < 0.001).
While non-responders (n = 168) showed comparable activity with untreated cancer
patients. Serum alkaline DNase activities were significantly elevated in
responders as compared to non-responders (p < 0.001). Our clinical studies during
follow-up of patients indicated that the variations in serum alkaline DNase
activities in individual patients correlate closely with response to therapy.
Serum alkaline DNase also appeared to be useful in predicting treatment response
in the long-term follow-up of patients. Serum alkaline DNase was systematically
examined as a possible indicator for recurrence in patients under complete
remission. In conclusion, serum alkaline DNase may be useful as a treatment
monitoring in patients with head and neck malignancies.
PMID- 10686538
TI - Endothelial nitric oxide synthase: correlation with histologic grade, lymph node
status and estrogen receptor expression in human breast cancer.
AB - Nitric oxide is produced by several isoenzymes which are present in many
different tissues. We have recently reported the presence of inducible nitric
oxide synthase in a breast cancer cell line. The purpose of this study was to
examine the distribution of endothelial nitric oxide synthase (eNOS) in a series
of human breast tumours. Immunohistochemical investigations demonstrated
immunolabelling of tumour cells with the primary antibody, bovine endothelial
anti-nitric oxide synthase. Although there was no correlation between eNOS
staining and tumour size, there was a significant (p < 0.005) negative
correlation (rho = -0.65) between the percentage of tumour cells staining
positive for eNOS and the histologic grade of the tumour; there was also a
significant (p < 0.05) negative correlation (rho = -0.40) between the percentage
of tumour cells staining positive for eNOS and the number of positive lymph
nodes. A significant (p < 0.005) positive correlation (rho = 0.63) between the
percentage of tumour cells staining positive for eNOS and estrogen receptor (ER)
expression by the tumour was also observed. In conclusion, our results
demonstrate that eNOS is expressed by human breast tumours and that its presence
negatively correlates with histologic grade and lymph node status and positively
correlates with ER expression.
PMID- 10686539
TI - Serum concentrations of tissue polypeptide antigen in patients with vulvar
intraepithelial neoplasia and vulvar cancer.
AB - The aim of the present study was to evaluate the clinical usefulness of the
cytokeratin tumor marker tissue polypeptide antigen (TPA) in patients with vulvar
cancer. This retrospective study comprises 41 patients with vulvar cancer FIGO
stages I-III, 17 patients with vulvar intraepithelial neoplasia (VIN) III, and 40
healthy female controls. Serum concentrations of TPA were measured using a
microparticle enzyme immunoassay. Results were correlated to clinical data.
Median serum concentrations of TPA in healthy female controls, patients with VIN
III, and patients with vulvar cancer were 42 U/l (range 12-192), 53 U/l (range 17
127.9) and 57 U/l (range 4.2-423), respectively (Mann-Whitney U test, p = 0.8).
Serum concentrations of TPA were not associated with stage of disease,
histological grade, and age at the time of diagnosis. In vulvar cancer patients,
elevated serum concentrations of TPA prior to therapy were not associated with a
shortened disease-free or overall survival (log-rank test: p = 0.5 and p = 0.9,
respectively). In a multivariate Cox regression model comprising tumor stage and
TPA, tumor stage, but not TPA revealed a statistically significant influence on
disease-free (Cox proportional hazard regression model, p = 0.05 and p = 0.6,
respectively) and overall (Cox proportional hazard regression model, p = 0.04 and
p = 0.8, respectively) survival of patients with vulvar cancer. We conclude that
cytokeratin expression, as reflected by serum concentrations of TPA, does not
play a role in the natural history of vulvar cancer. The evaluation of serum
concentrations of TPA prior to therapy is not recommended.
PMID- 10686540
TI - Expression of the tyrosine kinase activity growth factor receptors (EGFR, ERB B2,
ERB B3) in colorectal adenocarcinomas and adenomas.
AB - The overexpression of three growth factor receptors: epidermal growth factor
receptor (EGFR), ERB B2 and ERB B3 was evaluated immunohistochemically in 77
malignant and 15 benign colorectal neoplasms considering clinicopathological
variables (histological structure, grade of differentiation, tumor localization,
clinical stage of the disease). The relationship between the coexpression of EGFR
related proteins in individual patients was also evaluated. EGFR expression was
revealed in comparable percentages of colorectal adenoma and in adenocarcinoma
cases (80% and 70%) while ERB B2 expression was detectable more frequently in
adenoma than in adenocarcinoma cases (87% and 54%). The presence of ERB B3 was
observed in a higher percentage of adenocarcinoma than adenoma cases (65% and
40%). There was no correlation between the expression of studied tyrosine kinase
receptors and histological grade or Dukes' clinical stage and localization
(proximal or distal) of colorectal adenocarcinoma. The incidence of EGFR and ERB
B2 expression was higher in tubulovillous (100% for both receptors) than in
tubular adenomas (63% and 75%), while the ERB B3 receptor was revealed more
frequently in tubular than in tubulovillous neoplasms (50% and 28%). These
differences appeared to be statistically nonsignificant. The concomitant
expression of two growth factor receptors was observed in a higher percentage of
colorectal adenomas than adenocarcinomas, and the coexistence of three growth
factors was revealed in comparable percentages in malignant and benign colorectal
tumors. Our results support the promotional rather than direct transformational
role for the EGFR supergene family in colorectal tumorigenesis. The frequently
observed coexpression of more than one EGFR-related protein in colorectal
neoplasms indicates the possible cooperation of these receptors in mitogenic
signaling transduction, facilitating the development and maintenance of the
malignant phenotype.
PMID- 10686541
TI - Occurrence of carcinoma-associated antigen 494 in colorectal cancer tissue and in
Patients' sera during metastatic disease.
AB - CA 494 is a new carbohydrate epitope on a high-molecular-weight mucin-type
glycoprotein which has been intensively investigated in pancreatic cancer. In
this study, the occurrence of CA 494 was characterized in colorectal cancer
tissue and in patients' sera during metastatic disease. CA 494 was detected in
cancer tissue from 82% of the 49 patients studied. Serum levels of CA 494 were
elevated (>40 U/ml) in 66% of the same patients during metastatic disease (n =
41). The well-established tumor markers carcinoembryonic antigen (CEA) and CA 19
9 were increased (CEA >5 ng/ml; CA 19-9 >37 U/ml) in about 79% of these patients.
The correlation of CA 494 with CA 19-9 levels was lower (r = 0.532) than
previously reported in pancreatic cancer.
PMID- 10686542
TI - Cross-cultural traits for personality of patients with Parkinson's disease in
Japan.
AB - Recent studies suggest that Parkinson's disease (PD) is associated with
particular personality traits. Using Cloningers's Tridimensional Personality
Questionnaire (TPQ), Menza and colleagues [1993: Neurology 43:505-508] reported a
possible association between PD and a reduced score in the novelty seeking (NS)
dimension of the TPQ. We sought to determine whether this association, which was
found in a study conducted in the United States, could also be found among
Japanese PD patients. We performed personality assessments of 67 Japanese PD
patients, using the TPQ test. The results suggest that Japanese PD patients have
significantly lower scores in the NS dimension of the TPQ, as well as
significantly higher harm avoidance (HA) scores, compared with matched control
subjects. Furthermore, the PD patients undergoing treatment for depression using
antidepressant drugs scored significantly higher in the HA dimension than PD
patients who did not receive antidepressant drug treatment. Our results suggest
that the high HA score, and the low NS score in the TPQ test observed in patients
with PD, is a cross-cultural phenomenon, although the influence of depression,
long-term treatment, and premorbid gene/environmental interactions may also
affect these personality traits. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:1
3, 2000.
PMID- 10686543
TI - Searching for a locus for schizophrenia within chromosome Xp11.
AB - Three gene-rich loci-HS212G6, HSU93305, and HS884M20-within the short arm of the
X chromosome have been examined for allelic association with schizophrenia by the
transmission disequilibrium test in 70 families of male individuals affected with
schizophrenia. Neither the HS212G6 nor HS884M20 was found to be associated with
schizophrenia. The HSU93305 locus, however, was significantly associated with
schizophrenia (X(2)=17.92, df=3, P<0.001). The HSU93305 locus contains four
distinct genes. They code, respectively, for A4 differentiation-dependent
protein, triple LIM domain protein, synaptophysin, and calcium channel alpha-1
subunit. It is possible that one of these genes or some loci near to it may
predispose a vulnerability to schizophrenia. Am. J. Med. Genet. (Neuropsychiatr.
Genet.) 96:4-7, 2000.
PMID- 10686544
TI - Mutation analysis of the inwardly rectifying K(+) channels KCNJ6 (GIRK2) and
KCNJ3 (GIRK1) in juvenile myoclonic epilepsy.
AB - Genetic factors play a major role in the etiology of idiopathic generalized
epilepsy. However, in most syndromes, especially the common ones, multiple
genetic factors seem to be involved. Mutations in K(+) channel genes have
previously found to be associated with epilepsy both in humans and in mice. The
weaver mice phenotype, characterized by ataxia, tremor, male infertility, and
tonic-clonic seizures, is caused by a point mutation in the inwardly rectifier
K(+) channel gene KCNJ6 (GIRK2). A knockout mouse model deprived of functional
KCNJ6 protein is susceptible to spontaneous and provoked seizures without showing
the histological signs of neuronal cell death found in the weaver mouse. Thus,
the KCNJ6 gene seems to play an important role in seizure control. We therefore
performed a mutation analysis of KCNJ6 and the related KCNJ3 gene in 38 patients
with juvenile myoclonic epilepsy (JME). Two novel same-sense nucleotide exchanges
were identified, but none of these changed the coding sequence. These results do
not support a major role for the KCNJ6/KCNJ3 heteromeric receptor in the etiology
of JME. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:8-11, 2000
PMID- 10686545
TI - Association analysis between mood disorder and monoamine oxidase gene.
AB - To ascertain whether mood disorders, including bipolar and unipolar, are
genetically associated with the monoamine oxidase A (MAOA) or monoamine oxidase B
(MAOB) gene in the Chinese population, 132 cases of mood disorder and 88 normal
controls were genotyped for the MAOA(CA)n, MAOB(GT)n, and MAOB(TG)n loci by the
method of amplification fragment length polymorphism. Among 132 cases with mood
disorder, eight alleles (size: 112-126 bp) of locus MAOA(CA)n, 12 alleles (size:
168-198 bp) of locus MAOB(GT)n, and nine alleles (size: 195-213 bp) of locus
MAOB(TG)n were observed. Comparison of the allele frequency of the three loci
showed no difference between mood disorder cases and normal controls on average.
When each group was stratified into several subgroups, significant differences
were found. On the MAOA(CA)n locus, the frequency of 116 bp allele was higher in
the female bipolar disorder cases (0.2581) compared with that in the female
unipolar disorder patients (0.1154) (Z=2.15, p<0. 05). On the MAOB(GT)n locus,
the frequency of 180 bp allele was higher in bipolar disorder patients (0.1579)
than that in normal controls (0.0678) (Z=2.05, p<0.05). The frequency of this
allele was even higher in female bipolar disorder patients (0.1719) than that in
female normal controls (0.0541). On the MAOB(TG)n locus, the frequency of 205 bp
allele was higher in female bipolar disorder patients (0.6406) than that in
female normal controls (0.4375) (Z=2. 17, p<0.05). For the unipolar disorder
patients, the frequency of this allele was higher in female cases (0.5222) than
that in male cases (0.1818) (Z=3.49, p<0.05). As for association studies,
significant association between bipolar disorder and MAOB gene was detected. For
the 180 bp allele of MAOB(GT)n, the relative risk (RR) of biploar versus normal
control was 2.58 (p<0.05), and the RR of female bipolar disorder versus female
normal control was 3.63 (p<0. 05). For the 205 bp allele of MAOB(TG)n, the RR of
female bipolar disorder versus female normal control was 2.29 (p<0.05). Am. J.
Med. Genet. (Neuropsychiatr. Genet.) 96:12-14, 2000.
PMID- 10686546
TI - Chromosome 22q11 deletions are not found in autistic patients identified using
strict diagnostic criteria. IMGSAC. International Molecular Genetics Study of
Autism Consortium.
AB - A group of 103 subjects with a strict diagnosis of autism were tested for
deletion of band q11.2 on the long arm of chromosome 22. No deletions were found,
indicating that when a patient has been diagnosed with autism using strict and
consistent criteria, in the absence of other indications, it is unlikely that
this individual will have a 22q11 deletion. Testing for 22q11 deletions is
therefore unlikely to be necessary in these patients. Am. J. Med. Genet.
(Neuropsychiatr. Genet.) 96:15-17, 2000.
PMID- 10686547
TI - Suggestive evidence of a locus on chromosome 10p using the NIMH genetics
initiative bipolar affective disorder pedigrees.
AB - As part of a four-center NIMH Genetics Initiative on Bipolar Disorder, a genome
screen using 365 markers was performed on 540 DNAs from 97 families, enriched for
affected relative pairs. This is the largest uniformly ascertained and assessed
linkage sample for this disease, and includes 232 subjects diagnosed with bipolar
I (BPI), 32 with schizo-affective, bipolar type (SABP), 72 with bipolar II
(BPII), and 88 with unipolar recurrent depression (UPR). A hierarchical set of
definitions of affected status was examined. Under Model I, affected individuals
were those with a diagnosis of BPI or SABP, Model II included as affected those
fitting Model I plus BPII, and Model III included those fitting Model II plus
UPR. This data set was previously analyzed using primarily affected sib pair
methods. We report the results of nonparametric linkage analyses of the extended
pedigree structure using the program Genehunter Plus. The strongest finding was a
lod score of 2.5 obtained on chromosome 10 near the marker D10S1423 with
diagnosis as defined under Model II. This region has been previously implicated
in genome-wide studies of schizophrenia and bipolar disorder. Other chromosomal
regions with lod scores over 1.50 for at least one Model Included chromosomes 8
(Model III), 16 (Model III), and 20 (Model I). Am. J. Med. Genet.
(Neuropsychiatr. Genet.) 96:18-23, 2000
PMID- 10686548
TI - Potential panic disorder syndrome: clinical and genetic linkage evidence.
AB - This paper reports evidence for a possible "chromosome 13 syndrome," which
includes panic disorder, kidney or bladder problems, serious headaches, thyroid
problems (usually hypothyroid), and/or mitral valve prolapse (MVP). In the course
of a genetic linkage study of panic disorder, we noted these medical conditions
in individual family members. (We were blind to family relationships and marker
data.) We hypothesized that there may exist a subgroup of panic families with
these medical conditions, which for simplicity we called it the "syndrome."
Subsequently we reclassified the families as with or without the "syndrome" and
extended the phenotype for analysis to include the above medical conditions. All
these classifications were also done before the analysis and blind to marker
data. We then examined our linkage results, looking for significant differences
between families with and without the "syndrome" (using several definitions of
the "syndrome")-i.e., testing for genetic heterogeneity. When the families with
and without bladder/kidney problems were separated from each other, one marker
D13S779 (ATA26D07)-yielded a lod score of over 3 in the families with
bladder/kidney problems. This lod score went up to 4.2 in these families when we
diagnosed any individual with any one of the "syndrome" conditions as affected.
These results were statistically significant even after applying an extremely
overconservative Bonferroni correction for multiple tests. We present these
results in order to alert other investigators working on panic disorder, for
replication. If replicated, one may hypothesize that a candidate gene for the
syndrome should be expressed in CNS, kidney, gut, thyroid, etc. We also noted
that two independent studies report recent linkage findings between schizophrenia
and the same region on chromosome 13. No connection between schizophrenia and
panic disorder has ever been reported. Finally, we suggest that genetic studies
of psychiatric disorders might prove more fruitful if phenotypes were expanded to
include possible manifestations of the disorder in medical (non-mental) symptoms.
Am. J. Med. Genet.(Neuropsychiatr. Genet.) 96:24-35, 2000.
PMID- 10686549
TI - Genetic associations with clinical characteristics in bipolar affective disorder
and recurrent unipolar depressive disorder.
AB - Genetic factors may be associated with disease subtype as well as susceptibility.
We have therefore typed polymorphisms at the serotonin transporter, dopamine
receptor, tryptophan hydroxylase, tyrosine hydoxylase, and monoamine oxidase A
(MAOA) loci in 139 unipolar and 131 bipolar patients and investigated
associations with gender, number of episodes, age of onset, history of psychotic
symptoms, history of suicidal behavior, and history of substance abuse. In
bipolar subjects, the promoter variable number tandem repeat (VNTR) allele 132 of
MAOA was associated with history of suicide attempts, P = 0.029, particularly in
females, P = 0.006. The Fnu4HI allele 1 of MAOA was also associated with history
of suicide attempts in females, P = 0.0162. The serotonin transporter promoter
allele 2 was associated with increasing number of manic episodes, P = 0.02, and
history of psychotic symptoms, P = 0.0243. One significant association was found
in the unipolar group: dopamine D2 receptor promoter allele 2 with history of
psychotic symptoms, P = 0. 0165. We have tested multiple loci for a variety of
different clinical variables and performed 228 tests of significance in total. It
is possible that these preliminary findings are type 1 errors, because one would
expect 11 of the 228 tests to reach a nominal significance level of P < 0.05 by
chance alone if all the tests were independent. The associations with the MAOA
and serotonin transporter loci are consistent with previous data suggesting
associations with susceptibility to bipolar affective disorder. Am. J. Med.
Genet. (Neuropsychiatr. Genet.) 96:36-42, 2000
PMID- 10686550
TI - Analysis of linkage disequilibrium in gamma-aminobutyric acid receptor subunit
genes in autistic disorder.
AB - Autistic disorder (AD) is a neurodevelopmental disorder characterized by
abnormalities in behavior, communication, and social interactions and
functioning. Recently, Cook et al. reported significant linkage disequilibrium
with an AD susceptibility locus and a marker, GABRB3 155CA-2, in the gamma
aminobutyric acid(A) (GABA(A)) receptor beta3-subunit gene on chromosome 15q11
q13. This linkage disequilibrium was detected using a multiallelic version of the
transmission/disequilibrium test (TDT) in a sample of nuclear families having at
least one child with autistic disorder. In an attempt to replicate this finding
we tested for linkage disequilibrium with this marker, as well as with three
additional markers in and around the GABA(A) receptor beta3-subunit gene, in an
independent, clinically comparable set of AD families. Unlike Cook et al., we
failed to detect significant linkage disequilibrium between GABRB3 155CA-2 and AD
in our sample. We did, however, find suggestive evidence for linkage
disequilibrium with a marker, GABRB3, approximately 60 kb beyond the 3' end of
beta3-subunit gene. This finding lends support for previous reports implicating
the involvement of genes in this region with AD. Am. J. Med. Genet.
(Neuropsychiatr. Genet.) 96:43-48, 2000
PMID- 10686551
TI - No evidence for a major susceptibility locus for juvenile myoclonic epilepsy on
chromosome 15q.
AB - Juvenile myoclonic epilepsy (JME) is a distinct epileptic syndrome with a complex
mode of inheritance. Several studies found evidence for a locus involved in JME
on chromosome 6 near the HLA region. Recently, Elmslie et al. [1997] reported
evidence of linkage in JME to chromosome 15q14 assuming a recessive mode of
inheritance with 50% penetrance and 65% linked families. The area on chromosome
15q14 encompasses the location of the gene for the alpha-7 subunit of the
nicotinic acetylcholine receptor. This could fit the hypothesis that there are
two interacting loci, one on chromosome 6 and on chromosome 15 or that there is
genetic heterogeneity in JME. In an independent dataset of JME families, we
tested for linkage to chromosome 15 but found little evidence for linkage.
Moreover, families with more than one family member affected with JME provide a
lodscore of 3.4 for the HLA-DR/DQ haplotype on chromosome 6. The lodscore for
these same families on chromosome 15q14 is <-2 assuming homogeneity and the
maximum lodscore is 0.2 assuming alpha =.25. Only one of these families has a
negative lodscore on chromosome 6 and a positive lodscore of 0.5 on chromosome
15q14. Our results indicate that this possible gene on chromosome 15 plays at
most a minor role in our JME families. Am. J. Med. Genet. (Neuropsychiatr.
Genet.) 96:49-52, 2000.
PMID- 10686552
TI - Analysis of the serotonin transporter gene linked polymorphism (5-HTTLPR) in
anorexia nervosa.
AB - Previous studies have demonstrated aberrant expression of serotonin in
individuals with an eating disorder. Given this the serotonin transporter gene (5
HTT) is a strong candidate to contribute to the genetic component of the
aetiology of eating disorders. To determine the role of this particular gene in
the susceptibility to anorexia nervosa (AN) we have examined a tandemly repeated
sequence close to the promotor region of the 5-HTT gene, which is represented by
a long (L) and short (S) variant. Previous studies have shown that the
transcriptional activity of the 5-HTT gene differs significantly between these
two alleles. A group of 138 Diagnostic and Statistical Manual of Mental Disorders
(DSM-IV) criteria AN patients and 90 controls were genotyped at the 5-HTT gene
linked polymorphism (5-HTTLPR). Statistical analysis showed no significant
difference in allele or genotype frequencies between the two groups. These data
suggest that there is no association between 5-HTTLPR genotype and susceptibility
to AN, in our population. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:53-55,
2000.
PMID- 10686553
TI - Association of polymorphism of serotonin 2A receptor gene with suicidal ideation
in major depressive disorder.
AB - There is evidence indicating that density of 5-HT2A receptors is altered in brain
regions of depressed suicide victims and in platelets of suicidal subjects with
major depression or schizophrenia. Recent studies have also shown an association
between the allele C of 102T/C polymorphism in the 5-HT2A receptor gene and
schizophrenia. The present investigation tested the hypothesis that the observed
changes in 5-HT2A receptor density in platelets of patients with major depression
are a trait rather than state phenomenon and are associated with the 102 C allele
in 5-HT2A receptor gene in a sample of 120 patients with major depression and a
group of 131 control subjects comparable with respect to age, sex, and ethnic
background. The allele and genotype frequencies of 102T/C polymorphism in 5-HT2A
receptor gene were compared between patients and control subjects and between
suicidal and non-suicidal patient groups. The major finding of this study was a
significant association between the 102 C allele in 5-HT2A receptor gene and
major depression, chi(2) = 4.5, df = 1, P = 0.03, particularly in patients with
suicidal ideation, chi(2) = 8.5, df = 1, P < 0.005. Furthermore, we found that
patients with a 102 C/C genotype had a significantly higher mean HAMD item 3
score (indication of suicidal ideation) than T/C or T/T genotype patients. Our
results suggest that the 102T/C polymorphism in 5-HT2A receptor gene is primarily
associated with suicidal ideation in patients with major depression. Am. J. Med.
Genet. (Neuropsychiatr. Genet.) 96:56-60, 2000.
PMID- 10686554
TI - Anticipation in schizophrenia and bipolar disorder controlling for an information
bias.
AB - Anticipation was investigated in schizophrenia (SZ) and bipolar disorder (BP)
while addressing several biases in 18 large families (154 subjects) from Eastern
Quebec densely affected by SZ, BP, or both over three generations. In particular,
we controlled for an information bias using a measure of quality and quantity of
clinical information (QOI) concerning the subjects' illness. Otherwise, spurious
anticipation could have arisen because we found that QOI varied with the
generations as well as with the severity of illness. Although anticipation was
investigated separately for SZ and BP, both disorders were also included in one
analysis that tested anticipation under the unitary hypothesis that the SZ and
the BP spectrums represent a continuum of severity of the same disease. Age of
onset (AOO) and five indices of severity were tested for anticipation. Two
statistics were used: the difference in the mean AOO or severity between two
successive generations, and the mean difference in parent-offspring pairs (POP).
The study led to four main findings: 1) the choice of the statistics greatly
influenced the results, POP yielding systematically greater biased estimates; 2)
for SZ and BP, the evidence for anticipation with the five severity indices
vanished after controlling for QOI; 3) as regards AOO a decrease of 8.6 years, p
= 0.0001, and 5.3 years, p = 0.009 in AOO was found for SZ between Generations 1
2, and 2-3, respectively, despite controlling for QOI and addressing all biases;
and 4) conversely for BP, anticipation with AOO may be due to censoring. Findings
suggest that future anticipation studies should also control for QOI. Am. J. Med.
Genet. (Neuropsychiatr. Genet.) 96:61-68, 2000.
PMID- 10686555
TI - Peek-a-boo fragile site at 16d associated with Tourette syndrome, bipolar
disorder, autistic disorder, and mental retardation.
AB - Five patients with a fragile site at 16q22-23 and neuropsychiatric disorders are
reported. Three of five had Tourette disorder, three had mental retardation, two
had bipolar disorder, and one had autistic disorder. During our attempts to study
the fragile sites in more detail we were unable to reproduce the fragile sites
found several years earlier. The potential relationship between the fragile sites
and the neuropsychiatric disorders in these patients is discussed. Am. J. Med.
Genet. (Neuropsychiatr. Genet.) 96:69-73, 2000.
PMID- 10686556
TI - Evaluation of linkage of markers on chromosome 6p with schizophrenia in Taiwanese
families.
AB - Previous studies have indicated possible linkage of schizophrenia with chromosome
6p21-24. In an attempt to replicate these findings, we studied the linkage of
schizophrenia with nine markers on chromosome 6p21-24 in 39 Taiwanese
schizophrenic nuclear families with at least two affected siblings. Two
diagnostic models (narrow: Diagnostic and Statistical Manual of Mental Disorders
IV schizophrenia only; and broad: including schizophrenia, schizoaffective, and
other nonaffective psychotic disorders) were used to define the disease
phenotypes. With the broad and narrow diagnostic models, the marker D6S296
produced maximum two-point lod scores of 1.46 (straight theta = 0.2) and 1.35
(straight theta = 0. 2), respectively, in the recessive inheritance model.
Assuming locus heterogeneity, a multipoint lod score of 0.85 was obtained between
markers D6S296 and D6S277 under the narrow/recessive model. Maximum nonparametric
lod scores of 1.25 ( p= 0.09) and 1.36 (p = 0.08) were observed, but still not
statistically significant, at D6S296 in the narrow and broad diagnostic models,
respectively. Both two-point analysis of the dominant model (lod score 0.85) and
nonparametric analysis (lod score 1.25) showed a mild peak lod score appeared at
marker D6S 285 as well. The results add some support to the suggestive linkage of
schizophrenia with markers in the regions of chromosome 6p22 and 6p24 in an
ethnically distinct Taiwanese sample. Am. J. Med. Genet. (Neuropsychiatr. Genet.)
96:74-78, 2000.
PMID- 10686557
TI - Lack of association between temporal lobe epilepsy and a novel polymorphism in
the alpha 2 subunit gene (ATP1A2) of the sodium potassium transporting ATPase.
AB - Genetic linkage studies in rodents and humans have identified specific
chromosomal regions harboring seizure susceptibility genes. We have identified a
novel polymorphism in the human alpha 2 subunit gene (ATP1A2) of the sodium
potassium transporting ATPase (NaK-pump), a candidate gene for human temporal
lobe epilepsy (TLE) based on its chromosomal location and function in ion
homeostasis. The polymorphism consists of a four base pair insertion 12 base
pairs upstream of the start of exon 2. We performed an association study between
this polymorphism and TLE. Our study did not find a significant difference in the
frequency of this polymorphism between TLE patients and controls, indicating that
this variation is not a major susceptibility factor. However, since the number of
patients studied so far is small and the functional consequence of the
polymorphism is unknown, the variation may yet be found to play a minor role in
increased risk for seizure susceptibility. In contrast to the findings in TLE
patients and controls, we did find a significant difference in the frequency of
the variation between African Americans and persons of European descent. This
finding demonstrates the potential effect of population stratification on studies
of this type and supports the growing use of parental and familial samples for
controls in association studies. Further study of this polymorphism is warranted
as it may be involved in other disease processes for which there are known ethnic
specific susceptibilities. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:79-83,
2000.
PMID- 10686558
TI - Serotonin-2A receptor gene is not associated with symptomatology of
schizophrenia.
AB - The serotonin receptor type 2A (5-HT2A) is a primary candidate for involvement in
major psychoses. Polymorphisms within the 5-HT2A gene have recently been reported
to be associated with a variety of psychopathological conditions. In the present
study, we investigated the potential influence of the T102C polymorphism on the
psychopathology of schizophrenia. One hundred eighty-eight inpatients affected by
schizophrenia (DSM-III-R) were assessed by the Operational Criteria checklist for
psychotic illness (OPCRIT) and were typed for their 5-HT2A variants by PCR
techniques. Mania, depression, delusion and disorganization were the four
symptomatologic factors previously derived from our psychotic population that
were used to define phenotype in our sample. Genetic variants of the polymorphism
under study were not associated with these symptomatologic factors, and
consideration of possible stratification effects such as sex and age of onset did
not reveal any association either. Our results do not, therefore, support the
hypothesis that the serotonin receptor 2A gene is a liability factor for the
symptomatology of schizophrenia as defined by the OPCRIT checklist. Am. J. Med.
Genet. (Neuropsychiatr. Genet.) 96:84-87, 2000.
PMID- 10686559
TI - Analysis of the polymorphic (GT)(n) repeat at the dopamine beta-hydroxylase gene
in Spanish patients affected by schizophrenia.
AB - The presence of a polymorphic (GT)(n) repeat, a microsatellite repeat, at the
human dopamine beta-hydroxylase (DBH) gene had been previously investigated in
healthy people and in schizophrenic patients. The different DBH genotypes had
been found to be associated to different DBH biochemical function, but no
differences were found in the allelic and genotype frequencies between
schizophrenic and control groups. To further clarify the potential involvement of
the variation at the DBH gene in schizophrenia we have studied the DBH (GT)(n)
repeat in a sample of 47 Spanish schizophrenic patients, in their healthy
relatives (n = 72), and in a control population (n = 74). We have been able to
identify five different variants of the DBH gene (A1, A2, A3, A4, A5) in the
different groups. Subsequent statistical analysis revealed that the genotypes as
well as the allele frequencies did not differ significantly among schizophrenic
patients and the control population. Interestingly, the allelic variant A2 and
the genotype A4/A2 were significantly more frequent in schizophrenic patients as
compared with their healthy relatives. However, the association of the A2 allele
with schizophrenia was not supported by the haplotype relative risk analysis of
transmitted versus nontransmitted alleles. Therefore, although it will be
important to extend the present analysis in a larger sample of schizophrenic
patients and controls, our results suggest that the (GT)(n) does not seem to play
a major role in the genetics of schizophrenia at least in this group of Spanish
schizophrenic patients. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:88-92,
2000.
PMID- 10686560
TI - Selecting early onset MDD probands for genetic studies: results from a
longitudinal high-risk study.
AB - Recent studies have found high rates of familial aggregation of major depression
(MDD) in relatives of depressed children coming for treatment, leading
investigators to suggest that probands for genetic studies of MDD should be
selected from samples of depressed children being brought for treatment. Implicit
in this recommendation is the assumption that childhood and adult depression are
similar disorders. This assumption in turn implies that children with prepubertal
or adolescent onset depression are at high risk for having recurrent episodes of
MDD that continue into adulthood. The data supporting this latter hypothesis,
however, is limited and contradictory. In this article we report results from a
high-risk longitudinal family study in which we explored the recurrence and
continuity into adulthood of prepubertal or adolescent onset MDD in offspring who
were at high or low risk for MDD, by virtue of their parental depression status.
One hundred eighteen offspring from 55 families in which one or more parents had
MDD and 50 offspring from 21 families in which neither parent had MDD were
followed for more than 10 years (all offspring were 20 years or older at the end
of follow-up time) and blindly reassessed using a semistructured diagnostic
instrument. Offspring with childhood/adolescent onset MDD were at significantly
greater risk for recurrence in adulthood (after age 25) as compared with
offspring without an onset of childhood/adolescent MDD, if they had a history of
parental MDD. In contrast, among offspring without a history of parental MDD,
those with childhood/adolescent onset MDD were at no greater risk for continuing
to have MDD in adulthood (after age 25) than those without childhood/adolescent
onset MDD. Moreover, there was a trend for offspring with childhood/adolescent
onset MDD to be at greater risk for recurrence after age 25 if they had a history
of parental MDD, as compared with offspring without a history of parental MDD (60
vs. 18%). We conclude that childhood/adolescent onset MDD is a heterogeneous
disorder, with family history of MDD appearing to define a subtype of
childhood/adolescent onset MDD that is recurrent and continues into adulthood.
Our findings suggest that caution should be exercised in selecting depressed
children and adolescents brought for treatment as probands in genetic studies of
early onset MDD. A conservative strategy would be to select only those depressed
children and adolescents with a family history of MDD and reassess the treated
sample as they mature, ensuring that they go on to have MDD in adulthood. Am. J.
Med. Genet. (Neuropsychiatr. Genet.) 96:93-101, 2000
PMID- 10686561
TI - COMT and DRD3 polymorphisms, environmental exposures, and personality traits
related to common mental disorders.
AB - In a community sample of 2,327 Caucasians, we tested the hypotheses that
polymorphisms in the COMT and DRD3 genes are associated with personality traits
conferring vulnerability to anxiety, depression, or alcohol misuse, or with
current symptoms of these; and that the association is stronger in persons who
also have been exposed to stressor experiences. To conserve resources and to
allow replication, the genetic analysis was undertaken in two stages. For the
COMT polymorphism, no statistically significant associations were found in the
first sample of 862 persons. The remainder of the sample was therefore not
analysed for that gene. For the DRD3 polymorphism, those in the first sample with
at least one of the Ser(9) alleles had significantly higher scores in neuroticism
(p=0.006) and behavioral inhibition (p=0.003). There was a trend, failing to meet
the 1% significance criterion, for those with this genotype also to have higher
depression and anxiety. The groups did not differ in alcohol use. In persons with
the Ser(9) allele who were also exposed to stressors, there was a higher level of
depression at the 5% level; and the depression level was higher in homozygotes.
But when the remainder of the sample (1,465) was analysed, none of the
associations reached statistical significance. We conclude that neither the COMT
nor DRD3 polymorphisms are associated with anxiety, depression, or alcohol abuse.
Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:102-107, 2000
PMID- 10686562
TI - Integration of genetic maps by polynomial transformations.
AB - Currently available genetic maps differ in a variety of basic features; in
particular, with respect to the total length of the genome. Consequently, the
question arises as to the extent to which genetic maps are compatible to each
other, as well as to the methods with which genetic maps can be transformed into
one another. We propose a set of nonlinear, polynomial transformations that
enable the integration of genetic maps at a sufficiently high overall precision.
Our analysis of six major, publicly available maps, and iteratively optimized
polynomials of up to degree 5, yielded differences of = +/-0.8 cM between
empirical and reconstructed marker locations for >90% of points. Similarly, we
determined, at a slightly worse overall fit, those polynomials that enabled the
reconstruction of sex-specific recombination estimates from sex-averaged data.
Our results suggest that polynominal transformations may become a valuable
extension of standard map construction methods due to a rapid integration of
newly developed markers into existing maps. Am. J. Med. Genet. (Neuropsychiatr.
Genet.) 96:108-113, 2000.
PMID- 10686563
TI - Linkage study of two polymorphisms at the dopamine D3 receptor gene and attention
deficit hyperactivity disorder.
AB - Data from animal studies suggest that the dopamine D3 receptor gene may have a
role in locomotion and behavioral regulation. Therefore, this gene has been
suggested as a candidate for attention-deficit hyperactivity disorder (ADHD). The
dopamine D3 receptor gene (DRD3) has two common polymorphisms, one in exon I that
changes a Serine to Glycine (Ser9Gly) and alters the recognition site for the
restriction enzyme MscI [Lannfelt et al., 1992]. The other common polymorphism is
located in intron 5 and results in the change of a restriction site for MspI
[Griffon et al., 1996]. We investigated the possibility of linkage of the
dopamine D3 receptor gene in 100 small, nuclear families consisting of a proband
with ADHD, their parents, and affected siblings. We examined the transmission of
the alleles of each of these polymorphisms and the haplotypes of both
polymorphisms using the transmission disequilibrium test [Spielman et al., 1993].
We did not observe biased transmission of the alleles at either polymorphism or
any haplotype. Our findings using this particular sample do not support the role
of the dopamine D3 gene in ADHD. Am. J. Med. Genet. (Neuropsychiatr. Genet.)
96:114-117, 2000.
PMID- 10686564
TI - Polymorphisms of the sigma(1) receptor gene in schizophrenia: An association
study.
AB - Possible involvement of sigma receptors in the pathogenesis of schizophrenia has
been suggested. In this study we searched systematically for polymorphisms in the
5'-franking region of the sigma(1) receptor. Genetic variation in this region
could reduce the expression of the gene, and this suggestion is compatible with
findings of reduced sigma binding sites in several cortical regions of
schizophrenia. We confirmed G-241T and G-240T polymorphisms; these two
consecutive polymorphisms were resolved to be in complete linkage disequilibrium
with each other by single-strand conformation polymorphism (SSCP) analysis. We
also identified the A61C (Gln2Pro) polymorphism, which was in almost complete
linkage disequilibrium with G-241T/G-240T. There was no significant difference in
the distribution of alleles or overall genotypes of the polymorphisms between
schizophrenic patients (n = 129) and controls (n = 140). We found slight
increased homozygosity for T-241/T-240 and C61 in patients compared with controls
using multiple comparison (p = 0. 045). However, the significance did not remain
when a Bonferroni correction was made (p = 0.135). These results do not support
that the sigma(1) receptor gene plays a major role in the pathogenesis of
schizophrenia. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:118-122, 2000.
PMID- 10686565
TI - Lack of association between serotonin transporter gene promoter variants and
autistic disorder in two ethnically distinct samples.
AB - Family-based studies performed to date provide conflicting evidence of
linkage/association between autistic disorder and either the "short" [Cook et
al., 1997: Mol Psychiatry 2:247-250] or the "long" [Klauck et al., 1997: Hum Mol
Genet 6:2233-2238] allele of a polymorphic repeat located in the serotonin
transporter (5-HTT) gene promoter region, affecting 5-HTT gene expression [Lesch
et al., 1996: Science 274:1527-1531]. The present study was designed to assess
linkage and linkage disequilibrium in two new ethnically distinct samples of
families with primary autistic probands. The 5-HTT promoter repeat was genotyped
in 54 singleton families collected in Italy and in 32 singleton and 5 multiplex
families collected in the U.S.A., yielding a total sample of 98 trios.
Linkage/association between 5-HTT gene promoter alleles and autistic disorder was
assessed using the transmission/disequilibrium test (TDT) and the haplotype-based
haplotype relative risk (HHRR). Both the Italian and the American samples, either
singly or combined, displayed no evidence of linkage/association between 5-HTT
gene promoter alleles and autistic disorder. Our findings do not support
prominent contributions of 5-HTT gene variants to the pathogenesis of idiopathic
infantile autism. Heterogeneity in pathogenetic mechanisms underlying the disease
may require that linkage/association studies be targeted toward patient subgroups
isolated on the basis of specific biochemical markers, such as serotonin (5-HT)
blood levels. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:123-127, 2000.
PMID- 10686566
TI - Autistic symptoms among children and young adults with isodicentric chromosome
15.
PMID- 10686567
TI - Shining a light on the black box of the review process at Research in Nursing &
Health.
PMID- 10686568
TI - Families and hospitalized elders: A typology of family care actions.
AB - The extensive care provided by families to their elderly relatives in the home is
well documented. Although family caregiving is likely to be continued during
hospitalization of elderly relatives, limited research has been conducted to
address the nature of family care for hospitalized elders. The main purpose of
this qualitative study was to refine the content domain of family care for
hospitalized elders. Altogether 25 interviews were done. Of the 16 participants,
6 were family members, 6 were patients, and 4 were nurses; 7 participants were
interviewed once and 9 participants were interviewed twice. Qualitative analysis
based on Lofland and Lofland's (1984, 1995) approach resulted in the
identification of three major content domains: family members providing care to
the patient, working together with the health care team, and taking care of
themselves. This typology suggests a shift of research in this area from its
current focus on family needs to a view of family caregivers as partners with the
health care team.
PMID- 10686569
TI - Positive and negative outcomes of anger in early adolescents.
AB - The purposes of this study were to examine symptom patterns and diminished
general well-being as negative outcomes and vigor and change as positive outcomes
of trait and state anger via two structural equation models. In a school
auditorium, a convenience sample of 141 boys and girls, ages 12-14 years,
responded to the Trait Anger Scale and the State Anger Scale and to instruments
measuring general well-being, symptom patterns, vigor, and change. In the
negative outcome model, results indicated that diminished general well-being and
increased symptom patterns were outcomes of trait anger and state anger in early
adolescents. In the positive outcome model, contrary to expectation, less vigor
and less inclination to change were outcomes of trait anger in early adolescents,
while state anger had no appreciable influence on the same variables. The
findings suggest that anger, particularly trait anger, had a negative influence
on the outcome variables studied.
PMID- 10686570
TI - Sense of coherence and illness appraisal in older women's quality of life.
AB - The purpose of this descriptive, correlational study was to test a conceptual
model of proposed relationships between physical health limitation, the sense of
coherence, illness appraisal, and quality of life in a sample of 137 older women.
The typical respondent was 76, widowed, with an income less than $12,000, and
several health problems. Hierarchical multiple regression analysis indicated that
physical health limitation, particularly symptom bother and functional health,
had a significant negative influence on quality of life. However this effect was
mediated by sense of coherence and illness appraisal. Regardless of the level of
symptoms or functional health, women with higher sense of coherence and more
positive illness appraisals had higher levels of quality of life. The findings
support the proposed model and further our understandings regarding the
protective role of personality resources in perceived quality of life in older
women with chronic illnesses.
PMID- 10686571
TI - Continuous handrail support, oxygen uptake, and heart rate in women during
submaximal step treadmill exercise.
AB - Past research suggests that continuous handrail support during exercise
attenuates physiologic responses to exercise and reduces aerobic benefits;
however, this phenomenon has not been systematically studied in women exercising
on the step treadmill. The effects of three levels of handrail support
(continuous light, continuous very light, or no handrail support) on oxygen
uptake and heart rate during step treadmill exercise were examined in 15 healthy
women. Measures were obtained during 6 bouts of exercise, 3 bouts at 25 steps/min
followed by 3 bouts at 33 steps/min. At both step rates, mean oxygen uptake was
significantly reduced during continuous light and continuous very light handrail
support as compared with no handrail support, and mean heart rate was
significantly reduced during continuous light versus no handrail support. At 25
steps/min only, mean heart rate was significantly reduced during continuous very
light versus no handrail support. Findings indicate that women who use even
continuous light or continuous very light handrail support attenuate physiologic
responses during step treadmill exercise, thereby reducing aerobic requirements
and gaining suboptimal benefits from exercise.
PMID- 10686572
TI - The reliability and validity of two health status measures for evaluating
outcomes of home care nursing.
AB - The reliability, validity, and sensitivity of the Medical Outcome Study Short
Form (SF-36) and the Quality of Life Profile: Senior Version (QOLPSV) for
measuring outcomes of home care nursing were evaluated. Data were collected from
50 clients receiving home care nursing services. Twenty-two registered nurses and
six registered practical nurses collected client and nursing data on each home
visit. Client baseline and outcome measures were collected by two independent
evaluators at admission and discharge from the home care service. Internal
consistency reliability ranged from.76 to.94 for the eight subscales of the SF
36. Internal consistency reliability ranged from.47 to.82 for the nine subscales
of the QOLPSV. The subscales of both instruments had minimal problems with
missing responses. The SF-36 was found to be more sensitive than the QOLPSV to
change over time. In addition, the subscales of the SF-36 were found to be more
sensitive than the subscales of the QOLPSV to several of the nursing variables,
such as intensity of the client's nursing condition and skill mix.
PMID- 10686573
TI - Test of a model of psychosocial resources, stress, and health among undereducated
adults.
AB - The purpose of this study was to test a model drawn from the modeling and role
modeling theory depicting relationships among psychosocial resources, perceived
stress, and health for undereducated adults. A purposive sample of 171 adults
enrolled at an urban adult education center completed several self-report
measures: Modified Erikson Psychological Stage Inventory, Basic Need Satisfaction
Inventory, Perceived Stress, and Positive Health Index. Based on a structural
equation modeling analysis, psychosocial development and basic need satisfaction
had significant direct effects on health, with the expected positive signs.
Psychosocial development had the strongest direct effect on health and also had a
strong direct effect on basic need satisfaction and an indirect effect on health.
Support for the hypothesized model has important implications for nursing and
other community-based care provider interventions regarding health, including
strengthening psychosocial resources.
PMID- 10686574
TI - Personal and social determinants of rural nurses' willingness to care for persons
with AIDS.
AB - The purpose of this study was to investigate the individual and social
determinants of rural nurses' willingness to care for people with AIDS (PWAs).
Willingness to care was viewed as a function of nurses' personal attitudes about
AIDS care and PWAs; the influence of normative (significant others), comparative
(the nursing profession), and generalized (the rural community) reference group
norms on these attitudes; and how much importance respondents placed on
membership in these reference groups. Responses to a mailed questionnaire from
615 rural nurses were analyzed. Individual determinants were nurses' feelings of
preparedness and favorable attitudes about their personal safety when
administering care. Social determinants were the degree of upset of respondents'
significant others about their caring for AIDS patients and favorable attitudes
of the respondents about professional and social concerns related to AIDS.
PMID- 10686575
TI - Threats to validity in randomized clinical trials.
AB - The purposes of this article are to present an overview of randomized clinical
trials (RCTs) and describe some of the methodological problems inherent in using
RCTs in nursing research. Many nursing intervention studies are fraught with
problems that defy the stringent control criteria required for RCTs, leading to
biased estimates of intervention efficacy. Five threats to validity in RCTs are
presented, including problems related to (a) differential dropout, (b) random
assignment, (c) identifying and maintaining an adequate control condition, (d)
nonadherence to research protocols, and (e) assessment of clinically meaningful
change. Three strategies are recommended for addressing some of the problems
posed by RCTs and improving inference.
PMID- 10686578
TI - Effects of pro-inflammatory cytokines on apolipoprotein E secretion by a human
astrocytoma cell line (CCF-STTG1).
AB - Apolipoprotein (apo) E has been implicated in Alzheimer's disease; however,
little is known about the regulation of its secretion in astrocytes. To
investigate the effects of pro-inflammatory cytokines such as interleukin-1beta
(IL-1beta), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN
gamma) on apoE secretion by CCF-STTG1 cells, a sensitive and specific double
sandwich Enzyme-Linked ImmunoSorbent Assay (ELISA) was developed. Using a
monoclonal anti-human apoE antibody as the capture antibody, this assay was
carried out with commercially available reagents. The assay had a sensitivity of
0.013 ng per well, within-run and between-run variation coefficients of 6.0 and
8.6 per cent respectively. There was no cross-reactions between antibodies used
and apoAI, apoAII, apoB, apoCI, apoCII and apoCIII. Low apoE concentrations were
assessed using a serum-free HepG2 culture medium as secondary calibrator,
containing 59 microg l(-1) of apoE. In serum-free medium, CCF-STTG1 cells
secreted apoE, the accumulation of which in the cell medium increased linearly
with time (27 microg per 48 h). After 48 h of incubation, apoE secretion was
inhibited by TNF-alpha but not affected by IL-1beta and IFN-gamma. However, the
effect of regulatory factors may depend upon culture conditions since in the
presence of 10 per cent fetal calf serum, IFN-gamma significantly inhibited apoE
secretion. Thus, apoE secretion by CCF-STTG1 cells is inhibited by specific pro
inflammatory cytokines. This new apoE ELISA presents the great advantage of using
commercially available reagents which permit inter-laboratory comparability of
results, involves relatively low cost and is adaptable for the measurement of low
levels of apoE.
PMID- 10686577
TI - Degradation of focal adhesion proteins during nocodazole-induced apoptosis in rat
1 cells.
AB - Nocodazole, a microtubule-disrupting agent, induced apoptosis in Rat-1 cells, as
indicated by changes in cell morphology, DNA fragmentation, and eventual cell
death. During nocodazole-induced apoptosis, normally flat cells became rounded in
shape and detached from the extracellular matrix. These morphological changes
appeared to be closely associated with degradation of focal adhesion proteins,
including p130cas, p125(FAK) and paxillin. p130cas was also degraded in cells
treated with staurosporine or etoposide, suggesting that degradation of focal
adhesion proteins is a characteristic feature of apoptosis. Nocodazole-induced
apoptosis was antagonized by Bcl-2: degradation of focal adhesion proteins was
suppressed and cell viability was enhanced in bcl-2 over-expressing cells, even
in the presence of nocodazole. Further study of the molecular mechanism of Bcl-2
activation should provide an understanding of the apoptosis induced by disruption
of the microtubule network.
PMID- 10686579
TI - Modulatory effects of garlic and neem leaf extracts on N-methyl-N'-nitro-N
nitrosoguanidine (MNNG)-induced oxidative stress in Wistar rats.
AB - The effects of garlic and neem leaf extracts on lipid peroxidation and
antioxidant status during administration of N-methyl-N'-nitro-N-nitrosoguanidine
(MNNG), a carcinogenic nitrosamine were evaluated in male Wistar rats. Extracts
of garlic and neem leaf were administered orally for five consecutive days before
intraperitoneal injection of MNNG. Enhanced lipid peroxidation in the stomach,
liver and circulation of MNNG-treated rats was accompanied by a significant
decrease in glutathione (GSH) and the activities of glutathione peroxidase (GPx),
glutathione-S-transferase (GST) and gamma glutamyl transpeptidase (GGT).
Administration of garlic and neem leaf extracts significantly decreased the
formation of lipid peroxides and enhanced the levels of antioxidants and
detoxifying enzymes in stomach, the primary target organ for MNNG, as well as in
the liver and circulation. The results of the present study suggest that garlic
and neem may exert their protective effects by modulating lipid peroxidation and
enhancing the levels of GSH and GSH-dependent enzymes.
PMID- 10686580
TI - Angiotensin converting enzyme (ACE) activity levels in insulin-independent
diabetes mellitus and effect of ACE levels on diabetic patients with nephropathy.
AB - Involvement of complications is considered to be one of the major factors in the
prognosis of diabetes mellitus (DM). Recent studies indicate that most diabetic
complications such as nephropathy and hypertension are vascular-originated. Renin
angiotensin involvement, especially changes in ACE activity level, is considered
to be a key factor since ACE converts angiotensin I to angiotensin II which is a
potent vasoconstrictor and plays a vital role in the regulation of blood
pressure. Our present study focused on ACE activity levels along with blood
glucose and HbA(1c) levels in diabetic patients with (n=18) or without (n=25)
nephropathy as compared to control subjects (n=25). Blood glucose levels were
significantly higher in both diabetic groups compared to controls (p<0.001). On
the other hand, compared to controls, blood HbA(1c) levels were slightly higher
in DM patients without complications whereas they were significantly increased in
nephropatic DM patients (p<0.001). There was a very strong increase (p<0.001) at
the level of ACE activity in both of the diabetic groups (with nephropathy:
47.11+/-3.70 U l(-1); without complications: 43.72+/-2.93 U l(-1); controls:
25.15+/-2.30 U l(-1)). ACE activity levels were also significantly higher in
diabetic patients with nephropathy than in type II DM patients without
complication (p<0.01). Our results demonstrate that ACE activity levels are
increased in diabetic patients. Additional significant increase in ACE activity
levels in diabetic patients with complications such as nephropathy supports the
hypothesis that ACE activity has an essential role in the development of
complications in diabetes.
PMID- 10686581
TI - Intracellular protein degradation and autophagy in isolated pancreatic acini of
the rat.
AB - Simultaneous investigation of protein degradation and autophagy of isolated
exocrine pancreatic cells is carried out here for the first time in a systematic
way by a complex biochemical, morphological and morphometrical approach. Protein
degradation proceeds with a decreasing rate of 4-1.5 per cent per h over a 4-h
period indicating a comparatively low degradation capacity. Cells in freshly
isolated acini do not contain autophagic vacuoles but the latter appear within an
hour in vitro and their quantity remains close to a steady state during the
subsequent 3 h. Both traditional inhibitors of the autophagic-lysosomal pathway,
e.g. vinblastine, leupeptin, and lysosomotropic amines together with the recently
introduced 3-methyladenine, inhibit degradation to a similar maximal extent,
offering the possibility of the estimation of the ratio of lysosomal/non
lysosomal degradation. In pancreatic acinar cells autophagic sequestration is
unaffected and protein degradation is inhibited inside secondary lysosomes by
leupeptin and lysosomotropic amines, while 3-methyladenine prevents the formation
of autophagosomes. Vinblastine seems to act by inhibiting the fusion of
autophagosomes with lysosomes and there is no evidence for the stimulation of
autophagic sequestration by vinblastine in the present system. The effect of
inhibitors of protein breakdown on protein synthesis is variable and does not
correlate with their influence on degradation. Amino acids strongly stimulate
protein synthesis, but in contrast to what is found in liver cells, they do not
seem to affect protein degradation or autophagy significantly, thus indicating
major regulatory differences of these processes between pancreatic acinar cells
and hepatocytes.
PMID- 10686582
TI - Age-related changes in GM1, GD1a, GT1b components of gangliosides in Wistar
albino rats.
AB - In this study, age-related changes of GM1, GD1a, GT1b fractions of gangliosides
were investigated in whole brain of male Wistar albino rats. Insignificant
increases were detected in GM1 values from the third to the 24th month, whereas
GD1a and GT1b concentrations of ganglioside in 24-month-old rats decreased
significantly as compared to 6-month-old rats. Although there were no significant
differences in the GD1a/GT1b ratio of any groups, GM1/GD1a and GM1/GT1b ratios
were significantly increased as compared to 6-month-old rats. The increase in the
ratios of gangliosides are not due to an increase of GM1 fractions; they result
from a decrease of GD1a and GT1b fractions of gangliosides. In conclusion, the
concentration of ganglioside decreased with ageing.
PMID- 10686583
TI - Extracellular release of free fatty acids by rat T lymphocytes is stimulus
dependent and is affected by dietary lipid manipulation.
AB - [(3)H]-Arachidonic acid-labelled rat T lymphocytes released radioactivity
extracellularly when stimulated by the calcium ionophore A23187 or by monoclonal
antibodies to some cell surface structures (CD2, CD5, CD11a, CD18, CD54, T-cell
receptor) but not to others (CD49d, CD62L); release was greater with the calcium
ionophore. Almost all of the radioactivity released from anti-CD2-stimulated
lymphocytes was recovered in the free fatty acid fraction, whereas only about 50
per cent of that released after A23187 stimulation was recovered in this
fraction. A23187 stimulation resulted in release of arachidonic acid from a
variety of phospholipids (phosphatidylinositol, phosphatidylcholine and perhaps
phosphatidylethanolamine), while the monoclonal antibody stimulation released
arachidonic acid from phosphatidylinositol and perhaps phosphatidylcholine.
Unstimulated lymphocytes released a range of fatty acids extracellularly, with
palmitic acid accounting for 35-40 per cent and arachidonic acid for 5 per cent
of released fatty acid. Stimulation of lymphocytes with either anti-CD2 or A23187
increased total fatty acid release 1.5- to 1.8-fold. In both cases palmitic acid
remained the most predominant fatty acid released but the contribution of
arachidonic acid increased. The type of lipid fed to the rats significantly
influenced the amount and type of fatty acid released. Fish oil feeding
significantly reduced extracellular fatty acid release by stimulated lymphocytes.
PMID- 10686584
TI - Elevated levels of Ca(II) modulate the activity and inhibition of serine
proteases: implication in the mechanism of apoptosis.
AB - Elevated levels of intracellular Ca(II) are a prominent feature of apoptosis, a
natural form of cell death involved in many physiological and pathological
processes. Serine proteases play crucial roles in apoptosis and have been
implicated in the genomic DNA degradation and the massive protein degradation
that occur during apoptosis. In this study, the effects of the elevated level of
Ca(II) on the activity and inhibition of serine proteases were examined by
spectrophotometric methods. The effects of the elevated levels of Ca(II), Mg(II),
K(I), and Na(I) on the activity and inactivation of three representative members
of serine proteases were determined. The level of serine protease activity in CEM
C7-14 leukemic cells was also evaluated in the presence and absence of
dexamethasone-induced apoptosis, and also in the presence of A23187, a Ca(II)
ionophore. Among the four metal-ions studied, only Ca(II) was found to
significantly enhance the activity of mammalian serine proteases. Ca(II) was also
found to significantly protect the enzymes from inhibition, while the other three
metal-ions showed no significant effect on the inactivation of the enzymes.
Compared to the control sample, the enzymic activity was found to be higher
during apoptosis, and in the presence of the Ca(II)-ionophore. Results of this
study indicate that Ca(II) can significantly enhance the catalytic efficiency of
serine proteases during apoptosis.
PMID- 10686585
TI - Extracellular Ca(2+) suppresses endotoxin-inducible tissue factor activation in
monocytic THP-1 cells.
AB - BACKGROUND: Monocytic tissue factor (TF), an initiator of extrinsic blood
coagulation, is often activated under various inflammatory conditions including
endotoxemia. This activation could be a contributing factor to the manifestation
of disseminated intravascular coagulation following septic shock. HYPOTHESIS: We
herein determine if extracellular Ca(2+) ([Ca(2+)](ex)) regulates bacterial
endotoxin (LPS)-inducible monocytic TF activation. METHODS: We have employed a
model monocytic cell line (THP-1) to explore the mode of action of [Ca(2+)](ex)
on the modulation of LPS-induced TF activation. TF activity was measured by a
single stage clotting assay, while TF expression as well as LPS recognition and
its receptor expression were studied in immunofluorescent approaches. RESULTS:
LPS-induced TF activation was inversely correlated to [Ca(2+)](ex). Upon exposure
of THP-1 cells to LPS (1.5 microg ml(-1)) for 6 h in the Hanks' medium without
CaCl(2), TF was activated by nearly 10-fold. TF activation appreciably decreased
with the increasing [Ca(2+)](ex). No more than 3.5-fold TF activation was
detected at 5 mM [Ca(2+)](ex). Consistent with the significantly lower degree of
TF activation, LPS-induced TF expression at 5 mM [Ca(2+)](ex) was 60 per cent
less than that without [Ca(2+)](ex). FACScan analysis showed that LPS recognition
was significantly blocked at 5 mM [Ca(2+)](ex) which however had no effect on the
expression of CD14 and CD11b, the proposed major LPS receptors. Moreover, LPS
binding in vitro was significantly inhibited by 5 mM CaCl(2). CONCLUSION: Our
results demonstrate that [Ca(2+)](ex) blocked LPS recognition without affecting
its receptor expression on THP-1 monocytes. This insensitivity to LPS thereby
resulted in the depressed inducible monocytic TF expression and activation.
PMID- 10686586
TI - Transient expression of the glial glutamate transporters GLAST and GLT in
hippocampal neurons in primary culture.
AB - The extracellular glutamate concentration is kept low by glutamate transporters
in the plasma membranes. Here we have studied the expression of the glutamate
transporters GLAST, GLT and EAAC during the in vitro development of embryonic
hippocampal neurons grown in a defined (serum free) medium. Immunochemistry
studies showed that both the GLAST and GLT proteins are expressed in a
subpopulation of neurons at the early, but not at the later stages of the
cultures. Glial cells expressing the GLAST and GLT proteins were found at all
stages. EAAC was only detected in neurons. This is one of the first evidence of a
neuronal ability to express GLAST.
PMID- 10686587
TI - Activation of CA(2+)/calmodulin-dependent protein kinase IV in cultured rat
hippocampal neurons.
AB - Ca(2+)/calmodulin-dependent protein kinase IV (CaM kinase IV) is a
multifunctional enzyme that is abundantly present in the nuclei of neurons. We
report the properties of phosphorylation and activation of CaM kinase IV in
comparison to CaM kinase II in cultured rat hippocampal neurons. Phosphorylation
and activity of CaM kinase IV as well as CaM kinase II were increased by
treatment of neurons either with glutamate or high K(+). Glutamate-induced
phosphorylation and activity of CaM kinase IV were blocked by N-methyl-D-asparate
(NMDA) antagonists, and NMDA application instead of glutamate did increase CaM
kinase IV phosphorylation. CaM kinase IV phosphorylation was also increased by
alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), and was blocked by
an inhibitor of NMDA receptor. The AMPA-induced phosphorylation was blocked by
tetrodotoxin, a Na(+) channel blocker, that was expected to block endogenous
glutamate transmission indirectly. On the other hand, high K(+)-induced
phosphorylation and activation were not blocked by inhibitors of glutamate
receptors, and effectively blocked by nifedipine, an L-type Ca(2+) channel
blocker. These properties were similar between CaM kinase IV and CaM kinase II.
PMID- 10686588
TI - Lactacystin, a specific inhibitor of the proteasome, induces apoptosis and
activates caspase-3 in cultured cerebellar granule cells.
AB - The multicatalytic protease complex or proteasome is a fundamental nonlysosomal
tool that the cell uses to process or degrade proteins at a fast rate through the
ubiquitin and ATP-dependent proteolytic pathway. Examples of these important
proteins include the tumor suppressor protein p53, various cyclins, the cyclin
dependent kinase inhibitor p27, NFkappaB, IkappaB, c-fos, and c-jun. The
activation of proteolytic enzymes, including certain cystein-proteases of the ced
3/ICE (interleukin-1beta-converting enzyme) family, is a characteristic feature
of the apoptotic program. However, the role of the multicatalytic protease
complex in apoptosis is not well known. In order to obtain further information
regarding the participation of the ubiquitin-mediated pathway in the decision of
the cell to execute the cell death program, we have used a specific inhibitor of
the multicatalytic protease complex, lactacystin, in cultured cerebellar granule
cells. Cells were obtained from the cerebellum of 6- to 8-day-old Wistar rats and
cultured in Neurobasal medium supplemented with B-27. Addition of lactacystin to
the cultures induced apoptosis of the granule cells in a time-dependent fashion.
The morphological changes produced by the proteasome inhibitor included nuclear
condensation and DNA fragmentation measured by the diphenylamine test, as well as
a positive labeling by the TUNEL (terminal deoxynucleotidyltransferase mediated
dUTP nick end labeling) assay, all of them typical features of apoptosis.
Concomitant with apoptosis, there were changes in the expression of the ubiquitin
mRNA, a progressive depletion in the free ubiquitin pool, and an increase in the
high molecular weight ubiquitin-protein conjugates. Caspase-3, a member of the
ced-3/ICE family of cystein-proteases, showed a marked increase in activity in
the lactacystin-treated cells. In flow cytometry studies, the amount of cells in
the S phase of the cell cycle was smaller in the lactacystin-treated cells than
in controls, suggesting that apoptosis could be due, in part, to an alteration of
the cell cycle.
PMID- 10686589
TI - Roles of neuregulin in synaptogenesis between mossy fibers and cerebellar granule
cells.
AB - Neuregulins (NRGs), a large group of structurally related signaling proteins, are
likely to have important roles in the development, maintenance and repair of the
nervous system and other selected tissues. We have demonstrated, by using the
major form of NRG cloned from the mouse cerebellum that both the soluble form and
the membrane anchored form of NRG may serve different functions in
synaptogenesis. The soluble form of NRG was produced by proteolytic cleavage of
the membrane anchored form of NRG. The proteolytic cleavage was promoted by
protein kinase activation. The cleaved form of NRG trans-synaptically regulated
the expression of the NMDA (N-methyl-D-aspartate) receptor subunit NR2C as
neurally-derived factors, whereas the membrane anchored form of NRG showed a
homophilic binding activity between NRGbeta1s. In adult mice the membrane
anchored form of NRG was concentrated in neuro-terminals of both granule cells
and pontocerebellar mossy fibers. The fact that NRG can be functionally viewed as
cell recognition molecules as well as neurotrophic agents suggests new
possibilities for the important class of molecules.
PMID- 10686590
TI - Cyclic AMP regulates substance P expression in developing and mature spinal
sensory neurons.
AB - The tachykinin, substance P, has long been associated with transmission of
noxious stimuli. However, relatively little is known about signal transduction
pathways subserving peptidergic regulation in sensory neurons. To investigate
whether cyclic AMP (cAMP) could be a potential second messenger subserving
substance P expression, dorsal root ganglion neurons were grown in culture in the
presence of agents that increase content of cAMP. In developing neurons,
forskolin increased substance P content and survival almost threefold. Anti-nerve
growth factor (NGF) blocked the effect of NGF but not forskolin, suggesting that
increased cAMP acts directly and not via increased secretion of NGF from Schwann
cells and fibroblasts. In adult neurons, which do not require supplemental
trophic factors for survival, NGF and forskolin had similar effects on substance
P levels. Neither agent had any effect on somatostatin content of either
developing or mature sensory neurons. 8-bromo cAMP and isobutyl methylxanthine
duplicated the action of forskolin. Further, all three agents increased
expression of preprotachykinin mRNA. Forskolin appeared to increase both total
and neuron-specific expression of message as well as the number of neurons
expressing mRNA. Our results suggest that cAMP directly regulates substance P
content in sensory neurons from adult and neonatal rats.
PMID- 10686591
TI - Balance of two secretion pathways of nerve growth factor in PC12 cells changes
during the progression of their differentiation, with a decrease in constitutive
secretion in more differentiated cells.
AB - Proteins are secreted from animal cells by either a constitutive or a regulated
pathway. When cDNA of nerve growth factor (NGF) was introduced into PC12 cells,
these cells produced and secreted active NGF, where NGF was secreted not only in
constitutive but also in activity-dependent regulated way according to the
results of pulse-chase and ELISA studies. The regulated secretion was caused by
depolarization, cyclic AMP analogue, or beta-adrenergic agonist but not by
glutamate or carbachol. Because these transfected cells differentiated into a
morphology indistinguishable from that incubated with NGF protein, we next
compared the secretion pathways of NGF from PC12 cells at different stages of the
differentiation. NGF was secreted in both constitutive and regulated way at 2 and
7 days after the transfection of NGF-cDNA, but the constitutive secretion of NGF
from the more differentiated cells of Day 7 was decreased and mature NGF tended
to accumulate in the cells. These results indicate that the neurotrophin
secretion mechanism is intimately regulated in the course of the differentiation
of PC12 cells. Such a change in the protein secretion pathway might have an
profound role in the development of neurons.
PMID- 10686592
TI - Meizothrombin, an intermediate of prothrombin activation, stimulates human
glioblastoma cells by interaction with PAR-1-type thrombin receptors.
AB - Thrombin induces well-characterized effects on normal and neoplastic brain cells
by interaction with protease-activated receptor (PAR)-type thrombin receptors.
However, nothing is known about the function of intermediate enzymes of
prothrombin activation recently shown to evoke PAR-1-mediated signaling in smooth
muscle cells. Therefore, we investigated the effect of recombinant human
meizothrombin (rMT), one of thrombin's catalytically active precursor enzymes in
the prothrombin cleavage cascade, on calcium mobilization in human SNB-19
glioblastoma cells. By using reverse-transcription polymerase chain reaction,
immunofluorescence studies with a monoclonal anti-PAR-1 antibody and calcium
measurements, SNB-19 cells were shown to express functional PAR-1-type thrombin
receptors. PAR-1 is not only a receptor for thrombin in SNB-19 cells but was also
activated by rMT very effectively. Under the conditions used in our experiments,
SNB-19 cells stimulated with thrombin after rMT challenge were unable to elicit a
new calcium response and vice versa. In addition, both rMT and thrombin induced
no further calcium signal after that observed with the PAR-1-activating peptide
SFLLRN. Therefore, rMT and thrombin seem to activate calcium signaling by similar
mechanisms including PAR-1. Our results demonstrate rMT as a potent activator of
PAR-1-type thrombin receptors in SNB-19 glioblastoma cells, suggesting a function
of catalytically active thrombin precursor enzymes in cells of glial origin.
PMID- 10686593
TI - Uptake of circulating insulin-like growth factor-I into the cerebrospinal fluid
of normal and diabetic rats and normalization of IGF-II mRNA content in diabetic
rat brain.
AB - Brain injury has been prevented recently by systemic administration of human
insulin-like growth factor-I (hIGF-I). It is widely believed that protein
neurotrophic factors do not enter the brain from blood, and the mechanism by
which circulating hIGF-I may be neuroprotective is uncertain. This investigation
tested the hypothesis that hIGF-I is taken up into cerebrospinal fluid (CSF) from
the circulation. (125)I-hIGF-I was injected subcutaneously into rats. The (125)I
IGF-I recovered from CSF and plasma were indistinguishable in size from authentic
(125)I-hIGF-I on SDS-PAGE. An ELISA was used that detected immunoreactive hIGF-I,
but not rat IGF-I, rat IGF-II, human IGF-II, or insulin. Osmotic minipumps were
implanted for constant subcutaneous infusion of various hIGF-I doses. Uptake into
CSF reached a plateau at plasma concentrations above approximately 150 ng/ml hIGF
I; the plateau was consistent with carrier-mediated uptake. The plasma, but not
CSF, hIGF-I level was significantly reduced in streptozotocin diabetic vs.
nondiabetic rats, and uptake of hIGF-I into CSF was nonlinear with respect to
plasma hIGF-I concentrations. Nonlinear uptake excluded leakage or transmembrane
diffusion of IGF-I from blood into CSF as a dominant route for entry, but the
site and mechanism of uptake remain to be established. The IGF-II mRNA content
per milligram brain (P < 0.02) as well as per poly(A)(+) RNA (P < 0.05) was
significantly increased towards normal in diabetic rats treated by subcutaneous
administration of hIGF-I vs. vehicle. This effect of circulating hIGF-I may have
been due to regulation of IGF-II gene expression in the choroid plexus and
leptomeninges, structures at least in part outside of the blood-central nervous
system barrier. These data support the hypothesis that circulating IGF-I supports
the brain indirectly through regulation of IGF-II gene expression as well as by
uptake into the CSF.
PMID- 10686595
TI - Fibroblast growth factor modulates HIV coreceptor CXCR4 expression by neural
cells. HNRC Group.
AB - Recent studies suggest that the chemokine receptor CXCR4 may be involved in
mediating the neurodegenerative process in the brains of patients with acquired
immunodeficiency disease (AIDS). In this context, we hypothesize that
neurotrophic factors, such as fibroblast growth factor (FGF), might protect
against human immunodeficiency virus (HIV)-mediated neurotoxicity via regulating
the expression of CXCR4 in neural cells. For this purpose, levels of CXCR4 were
determined in neuronal and glial cell lines after FGF1 and 2 treatment. In
addition, levels of CXCR4 immunoreactivity were associated with levels of FGF1
immunoreactivity in the brains of HIV-positive patients. These studies showed
that neuronal CXCR4 levels decreased in a dose-dependent manner after exposure to
FGF. Conversely, glial CXCR4 was increased in a dose-dependent manner after FGF2
treatment. These effects were dependent on the FGF receptor tyrosine kinase
signaling pathway, because FGF-induced effects on CXCR4 were blocked by the
tyrosine kinase inhibitor, 5'-deoxy-5'methylthioadenosine, or by anti-FGF
receptor antibody. Stromal cell-derived factor-1, the ligand for CXCR4, and HIV
gp120 neurotoxicity was attenuated by FGF1 in a dose-dependent manner in vitro,
further supporting physiological relevance. In the brains of AIDS patients, the
levels of neural CXCR4 immunoreactivity were inversely associated with FGF
levels. Taken together, these results support the possibility that the
neuroactive effects of FGF in HIV encephalitis might be mediated through
regulation of the expression of CXCR4.
PMID- 10686594
TI - Short-term treatment with interferon-alpha/beta promotes remyelination, whereas
long-term treatment aggravates demyelination in a murine model of multiple
sclerosis.
AB - The mechanisms by which type I interferons (IFN) reduce the rate and severity of
exacerbations in multiple sclerosis are unknown. We utilized a model of multiple
sclerosis to determine the extent of demyelination and remyelination in Theiler's
murine encephalomyelitis virus (TMEV)-infected SJL/J mice treated with mouse IFN
alpha/beta for a short (5 weeks) or a long (16 weeks) period. All mice were
chronically infected with TMEV to simulate the clinical situation in multiple
sclerosis. Short-term IFN-alpha/beta treatment increased the percent of
remyelinated spinal cord white matter by threefold when compared with phosphate
buffered saline (PBS) treatment (P < 0.02), but it did not affect the extent of
demyelination. In contrast, long-term IFN-alpha/beta treatment increased the
extent of demyelination by twofold (P < 0.03). Long-term treatment increased the
absolute area of remyelination, but the percent remyelination as a function of
area of demyelination was not changed because of increased demyelination. An
immunomodulatory mechanism may have contributed to the effect of IFN-alpha/beta
on white matter pathology because treated mice had higher anti-TMEV IgGs in serum
and demonstrated decreased numbers of B and T lymphocytes infiltrating the
central nervous system (CNS). There was no correlation between the level of anti-
IFN-alpha/beta antibodies and the extent of demyelination or remyelination. These
results indicate that the length of type I IFN treatment may have paradoxical
effects on demyelination and remyelination.
PMID- 10686596
TI - Altered cell-matrix associated ADAM proteins in Alzheimer disease.
AB - Alterations in cell-matrix 'contact' are often related to a disruption of cell
cycle regulation and, as such, occur variously in neoplasia. Given the recent
findings showing cell cycle alterations in Alzheimer disease, we undertook a
study of ADAM-1 and 2 (A Disintegrin And Metalloprotease), developmentally
regulated, integrin-binding, membrane-bound metalloproteases. Our results show
that whereas ADAM-1 and 2 are found in susceptible hippocampal neurons in
Alzheimer disease, these proteins were not generally increased in similar
neuronal populations in younger or age-matched controls except in association
with age-related neurofibrillary alterations. This increase in both ADAM-1 and 2
in cases of Alzheimer disease was verified by immunoblot analysis (P < 0.05). An
ADAM-induced loss of matrix integration would effectively "reset" the mitotic
clock and thereby stimulate re-entry into the cell cycle in neurons in Alzheimer
disease. Furthermore, given the importance of integrins in maintaining short-term
memory, alterations in ADAM proteins or their proteolytic activity could also
play a proximal role in the clinico-pathological manifestations of Alzheimer
disease.
PMID- 10686597
TI - L-lactate inhibits L-cystine/L-glutamate exchange transport and decreases
glutathione content in rat cultured astrocytes.
AB - In several brain pathologies, the level of brain L-lactate increases. The
stimulation of L-lactate production is a detrimental factor in promoting neuronal
cell damage and astrocytic dysfunction. Astrocytic glutathione metabolism has an
important role to protect brain cells against oxidative stress. In this study,
effects of L-lactate on L-cystine uptake and glutathione level in rat-cultured
astrocytes were examined. L-Lactate decreased the L-(35)S-cystine and Na(+)
independent L-(3)H-glutamate uptakes into astrocytes at the concentrations more
than 2.5 mM. The L-lactate-induced decrease in L-(35)S-cystine uptake was neither
affected by modification of extracellular pH nor mimicked by acetate, propionate
and butyrate. The apparent Km value of the L-(35)S-cystine uptake was increased
by L-lactate, while the Vmax was not changed. Astrocytic glutathione and
nonprotein thiol content was decreased by incubation with 20 mM L-lactate for 48
hours (65% and 75% of control values, respectively). The decreases in astrocytic
glutathione and nonprotein thiol content were restored to normal levels by
withdrawal of L-lactate. These results suggest that L-lactate inhibits astrocytic
L-cystine/L-glutamate exchangers and affects the glutathione contents.
PMID- 10686598
TI - Fiber types in the mouse levator auris longus muscle: a convenient preparation to
study muscle and nerve plasticity.
AB - The histochemical composition of the levator auris longus (LAL) muscle has been
investigated in adult NMRi mice. Histochemical reaction for myofibrillar
adenosine triphosphatase (ATPase) after preincubation in alkaline and acidic
media, nicotine amideadenine-dinucleotide dehidrogenase (NADH-dehydrogenase), and
alpha-glycerophosphate dehydrogenase were performed on cryosections of LAL
muscle. Expression of myosin heavy chain (MyHC) isoforms was detected with the
immunoperoxidase method applying monoclonal antibodies against MyHC isoforms -1,
2a, -2x/d, and -2b, as well as by sodium dodecylsulfate (SDS) glycerol gel
electrophoresis. The muscle was proven to be a pure fast-twitch muscle. The most
numerous fibers in LAL muscles contained MyHC-2b and some MyHC-2a.
Histochemically, pure IIA fibers with oxidative metabolism and pure IIB fibers
with glycolytic metabolism were detected. In contrast to the majority of mature
control muscles, numerous hybrid fibers coexpressing MyHC-2x/d with MyHC-2a or
MyHC-2b were present. Both hybrids were oxidative-glycolytic; additionally, some
hybrids containing MyHC-2a were oxidative. In one out of six muscles, traces of
MyHC-1 were detected both with immunoperoxidase staining and with SDS glycerol
gel electrophoresis. Rare fibers that exceptionally expressed small amounts of
MyHC-1 always coexpressed MyHC-2a, which is an additional proof that pure type I
fibers do not exist in LAL. Due to these histochemical characteristics and to its
previously described morphological features, the use of the LAL muscle as a model
for various studies, particularly muscle and nerve interactions, is emphasized.
PMID- 10686599
TI - Cre recombinase: the universal reagent for genome tailoring.
PMID- 10686600
TI - Expression of Cre recombinase in mouse oocytes: a means to study maternal effect
genes.
PMID- 10686601
TI - Epiblast-restricted Cre expression in MORE mice: a tool to distinguish embryonic
vs. extra-embryonic gene function.
PMID- 10686602
TI - Targeted insertion of Cre recombinase into the TNAP gene: excision in primordial
germ cells.
PMID- 10686603
TI - HoxB6-Cre transgenic mice express Cre recombinase in extra-embryonic mesoderm, in
lateral plate and limb mesoderm and at the midbrain/hindbrain junction.
PMID- 10686604
TI - Cre recombinase expression in the floorplate, notochord and gut epithelium in
transgenic embryos driven by the Hoxa-1 enhancer III.
PMID- 10686605
TI - Expression pattern of a Krox-20/Cre knock-in allele in the developing hindbrain,
bones, and peripheral nervous system.
PMID- 10686606
TI - Targeted expression of Cre recombinase to myelinating cells of the central
nervous system in transgenic mice.
PMID- 10686607
TI - Retina- and ventral forebrain-specific Cre recombinase activity in transgenic
mice.
PMID- 10686608
TI - CaMKIIalpha-Cre transgene expression and recombination patterns in the mouse
brain.
PMID- 10686609
TI - Muscle specific expression of Cre recombinase under two actin promoters in
transgenic mice.
PMID- 10686610
TI - Analysis of the Cre-mediated recombination driven by rat insulin promoter in
embryonic and adult mouse pancreas.
PMID- 10686611
TI - Mosaic Cre-mediated recombination in pancreas using the pdx-1 enhancer/promoter.
PMID- 10686612
TI - Col2a1-directed expression of Cre recombinase in differentiating chondrocytes in
transgenic mice.
PMID- 10686613
TI - Inducible site-specific somatic mutagenesis in mouse hepatocytes.
PMID- 10686614
TI - DNA excision in liver by an albumin-Cre transgene occurs progressively with age.
PMID- 10686615
TI - Hepatocyte-specific expression of Cre recombinase.
PMID- 10686616
TI - Prostate specific expression of Cre recombinase in transgenic mice.
PMID- 10686617
TI - Ubiquitous postnatal LoxP recombination using a doxycycline auto-inducible Cre
transgene (DAI-Cre).
PMID- 10686618
TI - Characterization of an inducible, epidermal-specific knockout system:
differential expression of lacZ in different Cre reporter mouse strains.
PMID- 10686619
TI - Neural crest expression of Cre recombinase directed by the proximal Pax3 promoter
in transgenic mice.
PMID- 10686620
TI - Selective expression of Cre recombinase in skeletal muscle fibers.
PMID- 10686621
TI - Grip form and graphomotor control in preschool children.
AB - OBJECTIVE: The purpose of this study was to examine the utility of the grip scale
presented by Schneck and Henderson, the effect of grip form on drawing accuracy,
and the effect of implement diameter on grip form and drawing accuracy. METHOD:
Sixty boys and girls who were 3, 4, and 5 years of age performed 20 trials of a
precision drawing task, 4 trials each with five implements of varying diameters
(4.7, 7.9, 11.1, 14.3, and 17.5 mm). RESULTS: First, all 1,200 grips could be
coded according to Schneck and Henderson's 10-grip whole-configuration assessment
system, but the interrater reliability was lower than expected (.67 proportion of
perfect agreement). Second, using Schneck's five-level scoring system, the level
of grip significantly affected drawing accuracy, with the highest grip level used
most often with the highest accuracy scores and the lowest observed grip level
used most often with the lowest accuracy scores. Third, increasing implement
diameter led to significantly lower level grips but did not significantly affect
accuracy. CONCLUSIONS: Therapists are recommended to use Schneck and Henderson's
10-grip scale only for documenting the persons' grips and changes in their grips,
but if comparisons between individual persons are desired, then Schneck's five
level scale, which affords greater generalizability, should be used. Further,
children with graphomotor performance deficits are not likely to benefit from
grip manipulations because such strategies were shown to make better only
performance that is already good.
PMID- 10686622
TI - Clinical interpretation of "grip form and graphomotor control in preschool
children".
PMID- 10686623
TI - Developing a context-based performance measure for persons with schizophrenia:
the test of grocery shopping skills.
AB - OBJECTIVE: This article describes how authenticity and directness, desired
characteristics of performance measures, were applied to the development of a
context-based Test of Grocery Shopping Skills (TOGSS) for persons with
schizophrenia. METHOD: The steps used in developing the measure included
interviewing consumers with schizophrenia to identify issues in grocery shopping,
conceptualizing how authenticity and directness could be applied to shopping
performance, and selecting grocery items to be used in the test. The two forms of
the TOGSS were administered to 26 persons with schizophrenia or schizoaffective
disorders to evaluate reliability (stability, equivalence, interrater) and
validity (convergent, generalizability) of the TOGSS. RESULTS: The correlations
between the two forms of the TOGSS over two different testing periods were
significant, ranging from .64 to .83. Subscale scores were moderately correlated
(R = .52 to .94) with a similarly constructed test of drugstore shopping.
CONCLUSION: A systematic method can be used to develop a context measure of
performance. The TOGSS has beginning evidence of reliability and validity. With
further study, the test will be useful in assessing the independent living skill
of grocery shopping in persons with psychiatric disorders.
PMID- 10686624
TI - Understanding the experience of noninclusive occupational therapy clinics:
lesbians' perspectives.
AB - This article presents understandings about how noninclusive occupational therapy
environments are developed and maintained. The data are drawn from a study that,
in part, explored the experiences of lesbian or bisexual occupational therapists
working in a health care system. Ten participants each engaged in two to five in
depth audiotaped interviews. The narrative data were analyzed with a modified
form of grounded theory. The data provide insight into how heterosexist
occupational therapy work climates are created and maintained through four
processes: heterosexual discourse, homophobic comments, assumed heterosexuality,
and perceived stereotypes. The way in which heterosexist occupational therapy
work climates may impede the professional growth of therapists also is presented.
The knowledge gained from this study can help practitioners, professors, and
students in their attempts to sustain an inclusive environment with respect to
persons who are lesbian, gay, and bisexual.
PMID- 10686625
TI - Parental hopes for therapy outcomes: children with sensory modulation disorders.
AB - OBJECTIVE: Understanding parents' hopes for therapy outcomes is essential to
family-centered care. This qualitative study explored parents' points of view
regarding their hopes for the outcomes of occupational therapy using a sensory
integration treatment approach. METHOD: Data were collected as part of a larger
research project on the effectiveness of rehabilitating children who have sensory
modulation disorders. Five interviews were randomly selected from 17 parent
interviews conducted in the larger study. Data were analyzed using grounded
theory methods. FINDINGS: Three themes pertinent to the occupations of children
and two themes related to the occupations of parenting and sustaining family life
emerged. Child-focused outcomes include social participation, self-regulation,
and perceived competence. Parent-focused outcomes include learning strategies to
support children and obtaining personal validation. DISCUSSION: Interventions are
proposed that relate to children's participation in contexts in which they live,
learn, and play, as well as the support of parents in the occupations of
parenting.
PMID- 10686626
TI - Assessing father-infant interactions using the NCAST teaching scale: a pilot
study.
AB - OBJECTIVE: The purpose of this pilot study was to gather preliminary data on
father-infant dyads using the Nursing Child Assessment Satellite Training (NCAST)
Teaching scale, a parent-infant interaction measure, to determine whether and how
fathers score differently than mothers from normative samples. METHOD:
Interactions between first-time father (N = 15) and their infants, 3 months to 6
months of age, during the instruction of an unfamiliar play activity were rated
using the NCAST Teaching scale. Scores were compared both with a normative
database (N = 2,123) of mother-infant dyads and with a subsample (n = 34) of the
normative database to control for demographic variables, including the age,
gender, and birth parity of the child and the age, education, marital status, and
ethnicity of the parent. RESULTS: The fathers scored significantly lower on items
related to fostering the infants' cognitive growth than the mothers in the
normative database. However, the infants in this study provided clearer
behavioral cues and were more responsive to their fathers than the infants in the
normative sample. These findings were also true for the subsample comparison. The
fathers also scored significantly lower than the normative subsample on items
measuring their ability to foster the social and emotional growth of their
infants. CONCLUSION: There may be important differences in the interactions of
father-infant dyads compared with mother-infant dyads, but further research with
a larger, more representative sample of fathers on this parent-infant interaction
measure is warranted to support this. The development of normative scores for
fathers and their infants is recommended to accurately interpret father-infant
interactions when administering the NCAST Teaching scale.
PMID- 10686627
TI - Mothers' perceptions of child care assistance: the impact of a child's
disability.
AB - OBJECTIVE: This study examined and compared mothers' perceptions of child care
assistance provided by fathers and other caregivers. Awareness of child care
division of labor will assist occupational therapists in addressing the needs of
children with disabilities within the family context. METHOD: One hundred and
thirty-five mothers living in two-parent households kept a time diary of their
daily activities for 7 consecutive days using the Caregiver's Activity and
Recording of Events Inventory and estimated the percentage of child care their
partners performed, the amount of child care their partners performed, and their
satisfaction with this division of labor. One third of the women had children
with multiple disabilities, one third had children with Down syndrome, and one
third had children who were typically developing. RESULTS: The majority of
mothers in all three groups perceived that they were responsible for the majority
of child care. There were no significant differences between groups in terms of
mothers' perceptions of the amount of child care provided by fathers and other
caregivers, including relatives, childsitters, nurses, school personnel, and
neighbors. However, there were wide variations among families concerning child
care arrangements and division of labor. Seventy-five percent of mothers
indicated that they were satisfied with the division of child care labor between
mothers and fathers, and no significant correlation was found between perceived
percentage of child care performed and satisfaction with the division of labor.
CONCLUSION: Mothers in this study were responsible for the majority of child care
whether their child had a disability. The variation in number of hours that
others spent performing child care activities within individual families suggests
that there is no "best" or typical pattern. Occupational therapists need to
collaborate with families to determine a system of accommodations to manage their
daily routine that most effectively meets the family's needs.
PMID- 10686628
TI - Current parent education on infant feeding in the neonatal intensive care unit:
the role of the occupational therapist.
AB - OBJECTIVES: The purpose of this study was to describe current trends in parent
education on infant feeding in the neonatal intensive care unit (NICU) and to
clarify the role of the occupational therapist in educating parents. METHOD:
Questionnaires were mailed to 190 neonatologists across the United States who
were asked to forward it to a NICU occupational therapist. The questionnaire
gathered descriptive information about the structure of parent education in the
NICU, the role of the occupational therapist in providing parent education, and
demographics about respondents and their NICUs. The response rate was 53% (n =
100). RESULTS: All 100 hospitals responding provided parent education in some
form, and most included a variety of topics and teaching methods. Occupational
therapists were on the NICU team at 74 of the hospitals and were identified third
most frequently as a provider of parent education. The occupational therapists
were most frequently identified as responsible for teaching about positioning,
infant development, and infant states and cues and were highly involved in
educating parents about feeding. CONCLUSION: Current parent education programs in
NICUs are comprehensive in scope. Occupational therapists' role in educating
parents about infant care and feeding consists of a focus on certain topics where
occupational therapists have specialized skills and education. Occupational
therapists are recognized by their NICU colleagues as providers of parent
education, but this study suggests that the occupational therapists' role may not
be clearly understood by other NICU professionals.
PMID- 10686629
TI - Dynamic performance analysis: a framework for understanding occupational
performance.
AB - Occupational therapy is now consistently described as a profession concerned with
enabling occupation. A crucial step in enabling occupation is understanding the
occupational performance of our clients. Dynamic Performance Analysis (DPA) is a
new approach to occupational analysis that focuses on the client's actual
performance. DPA, acknowledging that optimal performance is the product of the
interaction of person, environment, and occupation, and thus highly
individualistic, places the client and his or her occupation, in interaction with
the environment, at the center of the analysis process. Embedded in a top-down
framework, DPA is a dynamic, iterative process, carried out as the client
performs the occupation. The purpose of DPA is to identify where performance
breaks down and test out solutions. In this article, the rationale, origins, and
basic assumptions of DPA are discussed, and a detailed description of the DPA
process together with two clinical examples is presented.
PMID- 10686630
TI - Playfulness in children with and without disability: measurement and
intervention.
AB - OBJECTIVE: The differences in playfulness between young children with cerebral
palsy and developmental delays and children who are typically developing, and the
comparative effects of two interventions (one focused on improving mother-child
interaction patterns, the other a neurodevelopmental treatment [NDT] session) on
children's playfulness were examined in this study. Reliability and validity of
the Test of Playfulness (ToP) also were examined. METHOD: Three trained raters
used the ToP to score 38 children, half with cerebral palsy and developmental
delays and half typically developing, as they played with their mothers. Mental
ages of the children ranged from 3 to 18 months. The mother-child dyads in which
the children had cerebral palsy and developmental delays were then randomly
assigned to an intervention group. After a 1-hr intervention to improve mother
child interaction, the children were rescored on the ToP. RESULTS: After
examination of ToP reliability and validity, children with cerebral palsy and
developmental delays were found to score significantly lower on the ToP than
their peers who were typically developing. In addition, children whose mothers
received an intervention to improve mother-child interactions scored
significantly higher on the ToP after intervention than before intervention.
However, the gain scores of children whose mothers received the intervention were
not significantly higher than those of children who received direct NDT.
CONCLUSION: The results suggested that when the shared goal of parents and
therapists is to enable children to express their inherent playfulness,
intervention to improve parent-child interactions may be more potent than
intervention directed at improving the child's developmental skills.
PMID- 10686631
TI - Perceptual-motor function of school-age children with slow handwriting speed.
AB - OBJECTIVES: This study investigated differences in perceptual-motor measures and
sustained attention between children with slow and normal handwriting speed and
the relationship between these factors. METHOD: Thirty-four slow handwriters and
35 normal speed handwriters (7 to 11 years of age) attending elementary schools
in Taiwan were given three perceptual-motor tests and a vigilance task to assess
sustained attention. Performances on these measures were analyzed using
multivariate analysis of variance and regression analyses. RESULTS: A significant
difference was found between slow and normal handwriters in upper-limb
coordination, visual memory, spatial relation, form constancy, visual sequential
memory, figure ground, visual-motor integration, and sustained attention. The
three significant predictors of handwriting speed for the slow handwriters were
age, visual sequential memory, and visual-motor integration. For the normal speed
handwriters, age and upper-limb speed and dexterity were the only two significant
predictors. CONCLUSIONS: Slow and normal speed handwriters responded to
handwriting demands through different perceptual-motor systems. Whereas upper
limb speed and dexterity seems to play an important role in normal speed
handwriters, slow handwriters seem to rely more on visually directed processes,
including sequence memory and visual-motor integration.
PMID- 10686632
TI - Improving activities of daily living performance in an adult with ataxia.
PMID- 10686633
TI - Supervisory preparedness of occupational therapists.
PMID- 10686634
TI - Beyond the therapy model: building our future.
PMID- 10686635
TI - Gathering current research evidence to enhance clinical reasoning.
PMID- 10686636
TI - We cannot hang our hat on occupation alone.
PMID- 10686637
TI - Case management practice.
PMID- 10686638
TI - [Vena cava thrombosis in Behcet's disease. Analysis of a series of 10 cases].
AB - AIM: To study the clinical characteristics and the evolution of vena cava
thrombosis (VCT) in Behcet's disease (BD), as well as their association with
other severe symptoms. PATIENTS AND METHODS: Among 121 BD, we selected those with
VCT. All patients fulfilled the diagnostic criteria of the international study
group of Behcet's disease. Different clinical and paraclinical parameters were
determined and compared with the remaining group of patients (not having VCT)
with chi 2 test with Yates' correction. Protein C, protein S and antithrombin III
and anticardiolipin antibody (aCL) levels were measured in 9 patients; anti-beta
2-glycoprotein I antibodies (a beta 2GPI) were determined in 3 patients. RESULTS:
Ten patients had a vena cava thrombosis (8.2%). They were all male with an
average age of 35 years (range: 30-42). We had 3 cases of superior vena cava
thrombosis, 6 cases of inferior VCT, and one case of both. The average delay to
diagnosis of the VCT from the date of the BD diagnosis was 4.5 years (range: 6
months-14 years), and in one case the thrombosis revealed the disease. All
patients were clinically symptomatic and the installation of the symptoms were
progressive and insidious in all cases. Six patients had Budd-Chiari syndrome and
4 had a phlebitis of a lower limb. Among all the clinical characteristics
studied, only neurological manifestations was significantly higher in patients
with VCT (p = 0.001). Protein C, protein S and antithrombin III levels were
normal in all cases. One patients was positive for IgG aCL and no patient was
positive for a beta 2GPI. All our patients were treated by anticoagulation
therapy and high-dose prednisone combined with intravenous cyclophosphamide in 5
cases. One patient died due to liver failure. The 9 others are clinically
improved (6 cases) or stable (3 cases) after an average 2.5 year course.
PMID- 10686639
TI - [Motivations of requests for human immunodeficiency virus (HIV) infection
screening at the Centers of Information and Anonymous and Free-of-Charge
Screening. Study of 891 cases].
AB - In France, human immunodeficiency virus (HIV) testing is usually performed in
centers for information and anonymous cost-free detection (Centres d'Information
et de Depistage Anonyme et Gratuit, CIDAG). In this work, we studied the reasons
people ask for HIV testing at the CIDAG in Lyons. Eight hundred and ninety one
people were asked to give their reasons. The response ratio was 85% and the sex
ratio 1:1. Seventy-five percent of the people were single. The main motivation
was the desire to begin a relationship with another person without using condoms.
Nonetheless, we were impressed by the high level of high-risk behaviors. To our
knowledge, this is the first study about motivations of outpatients at the CIDAG.
PMID- 10686640
TI - [Neuromuscular complications of long-term treatment of inflammatory diseases. 3
cases].
AB - Chloroquine and colchicine, widely used in internal medicine practice for a
variety of inflammatory diseases including systemic lupus erythematosus,
rheumatoid arthritis, familial Mediterranean fever, and Behcet's disease, may
induce neuromuscular complications. Physicians must be familiar with this
diagnosis as this iatrogenic neuromuscular pathology may simulate polymyositis,
leading thus to inappropriate treatment with prednisone whereas the only
effective treatment is to discontinue the drug involved whenever possible. We
report three cases of toxic myopathy and/or neuropathy related to chronic
chloroquine or colchicine therapy for systemic diseases, and outline the main
points to be considered in this situation.
PMID- 10686641
TI - Central nervous system involvement in Sjogren's syndrome: evidence from
neuropsychological testing and HMPAO-SPECT.
AB - OBJECTIVE: To investigate the clinical, neuropsychological and imaging
manifestations of Sjogren's syndrome (SS), a chronic auto-immune disease with
peripheral and central nervous system (CNS) involvement. DESIGN/METHODS: Fourteen
female patients suffering from confirmed SS underwent within 2 weeks:
neurological examination, immunological staging, brain MRI, brain 99m Tc-HMPAO
SPECT, psychological evaluation and in-depth neuropsychological testing. RESULTS:
All patients showed neuropsychological abnormalities. The cognitive symptoms were
of the same type in all patients, mostly frontal lobe syndrome and memory
problems. The neuropsychological involvement was not associated with other kinds
of CNS involvement or MRI abnormalities, but accurately reflected HMPAO imaging
results. CONCLUSIONS: The results of this study indicate that cognitive
evaluation is the most sensitive clinical test to diagnose CNS involvement in
patients with SS, and that CNS involvement in SS seems to be more frequent when
systematically assessed by neuropsychological tests.
PMID- 10686642
TI - [Familial hypercholesterolemia].
AB - Familial hypercholesterolemia is characterized by a high plasma LDL-cholesterol
level. The low-density particles are the end-product of the triglyceride-rich
particles, i.e. VLDL, synthetized by the liver. These triglyceride-rich particles
are subsequently transformed into intermediate density lipoprotein by the
lipoprotein lipase and LDL after further triglyceride hydrolysis by the hepatic
lipase. The LDL particles are taken up in all cells by the mean of the LDL
receptor. A large body of evidence (including experimental, clinical,
epidemiological data as well as the results of large trial with lipid lowering
drugs) has accumulated to establish that these particles are one of the major
causative factor of atherosclerosis and its complications. Two different
mechanisms may be at work in the familial hypercholesterolemia: a mutation in the
LDL receptor or a single mutation in the apolipoprotein B100. Specific
therapeutic intervention should be undertaken to decrease the risk to develop
cardiovascular disease, mainly coronary heart disease. The therapeutic
intervention includes both a diet low in saturated fatty acids and cholesterol
and statins which are now the first line therapy. Fibrates are proposed to those
who do not tolerate statins and LDL-apheresis is associated to statin in the rare
homozygous familial hypercholesterolemia.
PMID- 10686643
TI - [Human immunodeficiency virus resistance to antiretroviral drugs].
AB - Antiretroviral compounds can select viral strains presenting mutations of the HIV
genome. Certain genotypic modifications are expressed by phenotypic resistance.
There is no cross resistance between different classes of compounds (nucleosides,
non nucleosides, antiproteases), but cross resistance is common within a given
therapeutic class. HIV resistance to antiretroviral compounds is one of the
principal causes of failure of antiretroviral treatments but cannot explain all
escapes. The number of resistance mutations is higher in patients with high viral
loads and in patients on multiple drug regimens. Currently resistance testing is
limited to clinical research protocols. The usefulness of resistance testing
remains to be validated. However the most eminent indications are epidemiological
surveillance of primary resistance in primary infections, therapeutic adaptation
after accidental exposure to HIV, and management of seropositive pregnant women.
Recent retrospective studies have shown that the genotype and the phenotype after
a first line treatment failure predict response to certain therapeutic
combinations. In the near future, resistance testing could be useful to adapt
antiviral strategies after earlier treatment failure.
PMID- 10686644
TI - [What present strategies are helpful in improving transfusion safety in France?].
AB - Transfusion safety rests on measures ensuring that patients are transfused in
accordance with the requirements of state-of-the-art scientific knowledge. This
strict attitude is part of a quality approach which now applies to all fields of
health. Transfusion is historically characterized by its ambivalence: it was the
first medical discipline which integrated Quality Assurance concepts, it was also
the first which proved unable to respond adequately in the face of uncontrolled
risks. Today transfusion must create a system to rapidly: identify any risk,
whether emergent or hypothetical; decide which action should be taken; monitor
and assess corrective action; study the medico-economic impact of the whole
approach. Quality assurance applies to every stage of the transfusion process,
from blood donor to labile blood component recipient. This includes blood donor
selection and biological control, labile blood component processing,
qualification, transport and conditioning, prescription and distribution of blood
components and transfused patient follow-up of. Quality controls, "safety locks",
must be implemented at every stage to allow early problem detection, thus
avoiding potentially dangerous attitudes and guaranteeing transfusion quality all
along the process. Medical prescriptions must follow similar rules and meet Good
Practice requirements defined by members of the medical and scientific community.
A transfusion should not be prescribed unless it is absolutely necessary. In
addition to sanitary surveillance, scientific surveillance must also be
implemented to help transferring the findings of fundamental research to
transfusion activities and continuously improve transfusion safety. INSERM is
initiating sociological studies to identify and better understand donors'
attitudes leading to risks. More sensitive tests based on nucleic acid
amplification should reduce the incidence of residual viral risks. Various viral
cell derivative inactivation techniques are being evaluated: the idea is to
remove antigens to suppress the risk of post-transfusion alloimmunization.
Numerous R&D; programs address substitution products. Transfusion safety requires
all actors in the field of health being equally involved. Putting together
experiences and know-how will continuously strengthen the quality approach
adopted in transfusion.
PMID- 10686645
TI - [Transfusion of platelet concentrates].
AB - Although a number of research have been realized in the aim of decreasing the use
of platelet concentrates, these blood products remain absolutely necessary for
patients with therapeutic aplasia and for some surgical patients. After the
description of the main rules of platelet transfusion procedures, we will discuss
some controversial issues: threshold value for platelet transfusion, platelet
doses, place of curative and prophylactic strategies, refractoriness to platelet
transfusion, HLA alloimmunization. Then we will focus our review on the future
alternatives for platelet transfusion.
PMID- 10686646
TI - Allogeneic hematopoietic stem cell transplantation: current issues and future
prospects.
AB - Major developments have occurred in the field of hematopoietic stem cell
transplantation since the first successful transplants from HLA-identical
siblings in the late 60's. The formally experimental procedure has become
established therapy for a number of congenital or acquired disorders of the
hematopoietic system and for chemotherapy-sensitive malignancies. Reduced
transplant-related mortality has led to a widening of indications. The present
review summarizes current issues and future prospects in allogeneic stem cell
transplantation. These issues and prospects will include; stem cell sources,
alternative donors, graft-versus-host disease, indications and long-term survival
following allogeneic stem cell transplantation.
PMID- 10686647
TI - [Behcet's disease: apropos of the article by N. Filali-Ansary et al].
PMID- 10686648
TI - Chronicles add value to practices and progress.
PMID- 10686649
TI - The first modern operating room in America.
AB - The modern OR was a vital addition to aseptic technique and essential to the
development of invasive surgery, and many people do not realize that it needed to
be "invented." Gustav Neuber, William S. Halsted, Charles McBurney, and others
pioneered the necessary changes in practices and the environment to protect the
patient from infection. This article presents the history behind the evolvement
of the modern OR and discusses changes in the structures of some facilities as
awareness increased about the principles of asepsis.
PMID- 10686650
TI - Pharmacotherapeutics of positive inotropes.
AB - Pharmacology is integrated in all areas of nursing practice. From the most basic
entry level to the most advanced clinical practice, nursing curriculums are not
complete without pharmacology. The word "pharmacology" often makes nurses and
other health care professionals feel uneasy. Pharmacology implies complicated
words and formulas that seem foreign, recalled only from one's most distant
recollections of college years. For many health care providers, courses in
pharmacology are taken before they care for patients, leaving them with little
practical experience from which to relate. Education involves not simply learning
and doing, but also applying knowledge. A basic understanding of pharmacology is
needed to break down the barriers of pharmacologic communication and put the
clinician at ease with terminology so often used by the medical community.
PMID- 10686651
TI - Nonmetallic fixation in elective maxillofacial surgery.
AB - Resorbable fixation technology offers several benefits, including easily cut and
shaped plates, strong and predictable resorption qualities, and improved patient
acceptance and expectations. Moreover, resorbable fixation implants can be
completely reabsorbed into the body, eliminating the need for subsequent removal.
This article describes the use of this innovative technology in orthognathic
surgery, including preoperative and postoperative patient needs, intraoperative
patient care, and potential complications.
PMID- 10686652
TI - Gastrointestinal surgical patients' outcomes influenced by nutrition.
AB - Nutritional support differs for patients electing to have gastrointestinal
surgical procedures and patients with abdominal trauma injuries. Trauma patients
can rehabilitate more quickly than patients undergoing gastrointestinal
surgeries, despite the traumatic injuries that require surgical intervention.
This literature review examines and evaluates the clinical practice and
management of these patients and the consequences of surgical nutritional
deprivation.
PMID- 10686653
TI - Effective pain management in older patients.
AB - Assessing and managing post-operative pain in older adult patients is complex. A
baseline preoperative pain assessment provides the necessary data that assist
appropriate and effective pain management. Careful monitoring and
individualization of patient dosages result in effective older adult patient pain
management.
PMID- 10686654
TI - Recommended practices for documentation of perioperative nursing care.
Association of periOperative Registered Nurses.
PMID- 10686655
TI - New information on the role of beta-blockers in cardiac therapy.
AB - Hypertension and ischemic heart disease are important precursors of heart
failure. The prevention of progression to heart failure is a prime objective when
treating patients with hypertension or ischemic heart disease. In patients with
hypertension, treatment with either diuretics or beta-blockers reduces the risk
of chronic heart failure. In patients with ischemic heart disease, beta-blocker
therapy reduces the risk of recurrent myocardial infarction and ensuing cardiac
dysfunction. The beneficial effects of beta-blocker therapy may be greater in
post-infarction patients who have impaired left ventricular function than in
those patients without such impairment. When considering heart failure itself,
the efficacy of angiotensin-converting enzyme (ACE) inhibitors has been
demonstrated in patients with mild-to-severe left ventricular dysfunction and
their use is indicated for all stages of heart failure to reduce symptoms and
retard further impairment of left ventricular function. Diuretics and digitalis
offer relief from the symptoms of the disease, while positive inotropes are
reserved for parenteral administration in end-stage heart failure, as a bridge to
transplantation, or in acute exacerbations of the disease. Added to standard
therapy, beta-blockade is of value in the treatment of heart failure, preventing
further deterioration and improving hemodynamics, exercise tolerance, quality of
life, and longterm prognosis.
PMID- 10686656
TI - Antithrombotic activity of the superoxide dismutase-chondroitin sulfate complexes
in a rat model of arterial injury.
AB - Individual antithrombotic activities of superoxide dismutase (SOD) and sodium
chondroitin sulfate (CHS) as well as the activities of covalent and noncovalent
complexes of SOD with CHS were compared in a rat model of arterial thrombosis
induced by ferrous chloride. Covalent conjugate of SOD with CHS exerted the most
potent antithrombotic effect, which was associated with adsorption of the
conjugate on the glycocalyx of the vascular wall cells and stability of the
covalent bond between CHS and SOD subunits. Theoretical and practical directions
in the investigation of SOD and CHS preparations are outlined.
PMID- 10686657
TI - Effect of low-dose aspirin on the markers of oxidative stress.
AB - The present study estimates effects of low-dose enteric coated aspirin (ECA) on
oxidative stress (OS) markers in a group of middle-aged men (mean age 51.2 +/-
6.9 years) free of pre-existing ischemic heart disease. METHODS: Serum products
of lipid peroxidation, and measures of antioxidative status were detected in 25
healthy men in baseline and after two-week treatment period. RESULTS: In respect
to serum products of lipid peroxidation and markers of antioxidant status, no
statistically significant differences between the pre- and after-treatment data
were observed for any measures, with the exception of values of serum
antioxidative capacity (39.0 +/- 2.5 and 42 +/- 4.6, respectively). CONCLUSIONS:
Administration of ECA does not initiate the OS in blood and improves the general
antioxidative potency of blood. This may imply towards certain antiatherogenic
influence of low-dose ECA, exhibited even with a short-term treatment period.
Regarding OS markers, a variety of individual responses observed in the selected
subgroups should be investigated and possibly taken into account while treatment
with ECA is initiated for primary prevention of cerebrovascular events.
PMID- 10686658
TI - Pharmacological modification of the dispersion of repolarization in the heart:
importance of the M cells.
AB - Several in vitro and in vivo investigations have provided data supporting the
existence of M cells in the deep subepicardial layers of the ventricles in a
number of species. Characterized by unique electrophysiological and
pharmacological features, this population of cells is regarded to have a
significant role in creating dispersion of repolarization in the ventricular wall
and thus contribute importantly to arrhythmogenesis, in particular to intramural
reentry and triggered activity. Focusing on M cells, the authors summarize recent
findings and concepts concerning the pharmacological heterogeneity of different
cell and tissue types found within the ventricles and explore how these
differences may contribute to electrocardiographic manifestations. On the basis
of literary data and of their own results they conclude that studying the
electrical and pharmacological inhomogeneity within the ventricular wall may
provide a better understanding of the pathophysiological processes that give rise
to cardiac rhythm disturbances and the mechanisms by which antiarrhythmic agents
act to suppress and in some cases aggravate arrhythmias.
PMID- 10686659
TI - Evaluation of atrial refractoriness and atrial fibrillation inducibility
immediately after internal cardioversion in patients with chronic persistent
atrial fibrillation.
AB - OBJECTIVE: To prospectively evaluate right atrial refractoriness and sustained
atrial fibrillation (AF) inducibility at programmed electrical stimulation in two
groups of patient: a series of patients with chronic persistent AF, studied
immediately after successful low energy internal atrial cardioversion, and a
group of control patients without history of supraventricular arrhythmias.
PATIENTS: Nineteen patients with chronic persistent AF (mean AF duration 11 +/-
10 months, range 2-61 months) submitted to successful internal low energy atrial
cardioversion in fully conscious state and 11 control patients without history of
supraventricular arrhythmias. METHODS: An electrophysiological evaluation was
performed to measure atrial refractoriness and AF inducibility, by delivering
single atrial extrastimuli in high right atrium, at decremental coupling, during
spontaneous sinus rhythm and after 8 beats at 600, 500, 400 and 330 ms cycle
length. If sustained AF was induced the protocol was terminated. RESULTS: During
programmed atrial stimulation sustained AF was induced in 8 out of 19 (42%) of
the AF patients but in none of the control group. Atrial effective refractory
period was significantly shorter in AF patients compared to controls both at
basic cycle length, at 600 ms, 500 ms and 400 ms cycle length, meanwhile no
statistically significant differences were found at 330 ms cycle length. An
altered relationship between atrial effective refractory period and cycle length
was found in AF patients compared to controls: the slope of linear correlation
slope was significantly lower in AF group than in controls (0.04 +/- 0.07 vs 0.17
+/- 0.10, p < 0.002). CONCLUSIONS: Marked abnormalities of atrial refractoriness
and of its heart rate relationship are observed after internal cardioversion of
chronic persistent AF in humans and these abnormalities are associated with an
high vulnerability to AF. These observations may explain the high risk of AF
recurrences in the early phases following successful cardioversion. In this
scenario antiarrhythmic drug therapy seems to be mandatory for reducing
arrhythmia relapses.
PMID- 10686660
TI - Amlodipine and physiological responses to brisk exercise in healthy subjects.
AB - Recent studies have questioned the safety of calcium antagonists in general, and
short-acting dihydropyridine derivatives in particular. Reasons include excessive
catecholamine stimulation after stress. We therefore wanted to assess whether
amlodipine, a second generation dihydropyridine with a prolonged plasma half
life, would show a more favourable haemodynamic and biochemical profile after
strenuous exercise. For this purpose, we studied 9 healthy volunteers in a double
blind, randomized, placebo-controlled trial. After 10 days of amlodipine, 5 mg
orally daily or placebo therapy, volunteers performed a treadmill effort test;
the sequence was repeated after a 2-week washout period. Amlodipine caused a
significant increase in mean resting heart rate (HR) (from 65 +/- 3 to 70 +/- 3
beats/min, p < 0.05), without changing systolic or diastolic blood pressure (SBP,
DBP). Post-exercise haemodynamic responses were similar while on amlodipine or
placebo therapy. Amlodipine did not alter the normal profile of resting or
exercise-induced metabolic [plasma glucose, serum K+, serum free fatty acid
(FFA)] and hormonal [plasma cortisol, growth hormone, prolactin, insulin,
epinephrine (EPI) and norepinephrine (NE)] responses--although plasma EPI
concentrations dropped significantly lower (p < 0.05) at 5 min and 15 min post
exercise while on the calcium antagonist. We conclude that amlodipine has a
largely neutral effect on the physiological profile after brisk exercise in
healthy young subjects and that this may prove to be a useful property for a
vasodilator drug.
PMID- 10686661
TI - Cilnidipine improves insulin sensitivity in the Otsuka Long-Evans Tokushima fatty
rat, a model of spontaneous NIDDM.
AB - Among the antihypertensive drugs, fast-acting Ca2+ antagonists have been reported
to worsen insulin sensitivity. This effect may be attributable to reflex
increases in sympathetic activity. On the other hand, however, it has been
reported that long-acting, dihydropiridine Ca2+ antagonists improve insulin
resistance. The purpose of this study was to investigate whether cilnidipine,
another long-acting dihydropidine Ca2+ antagonist, improves insulin sensitivity
in Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of spontaneous NIDDM.
25 weeks OLETF rats were divided into the following groups; normal-diet group,
cilnidipine-supplemented group (cilnidipine 3 mg/kg/day) and angiotensin II
receptor antagonist CS-866-supplemented group (CS-866 1 mg/kg/day). As a non
diabetic control, we used Long-Evans-Tokushima-Otsuka rats (non-diabetic rats).
Glucose infusion rate (GIR), an index of insulin resistance, as measured by the
hyperinsulinemic euglycemic clamp technique was significantly decreased in OLETF
rats. Cilnidipine-treatment partially but significantly improved insulin
sensitivity in addition to systolic blood pressure in OLETF rats at 30 weeks of
age, although it did not decrease accumulation of abdominal fat or serum levels
of glucose or insulin. CS-866, an angiotensin II receptor antagonist, which
lowers blood pressure through a different mechanism, did not improve insulin
resistant states in OLETF rats. These results suggest that cilnidipine has a
beneficial effect on insulin-resistance together with the antihypertensive
effect.
PMID- 10686662
TI - Cardioprotective efficacy of verapamil and mibefradil in young UM-X7.1
cardiomyopathic hamsters.
AB - Since calcium overload and increased in T-type calcium channel activity have been
observed in the cardiomyopathic (CM) hamster, we hypothesized that mibefradil (Ro
40-5967), a new T- and L-type calcium channel blocker, may exert significant
cardioprotection in the early phase of the disease. Young (30-day-old) CM
hamsters of the UM-X7.1 subline were treated with mibefradil or verapamil for 4
to 6 weeks. Mibefradil doses were in the range of 0.5 to 8 mg/kg/day while
verapamil was given at a dose of 5-10 mg/kg/day, both drugs being injected twice
daily (s.c. and i.p. alternatively). At the end of the treatment period,
myocardial and skeletal muscle (tongue) were harvested and processed for
assessment of necrotic changes and calcification. In hearts from control CM
hamsters, numerous necrotic and calcified foci were observed. These myocardial
necrosis markers were not attenuated by mibefradil in the dose range studied
whereas verapamil significantly reduced their severity. The dystrophic process in
skeletal muscle (tongue) was not inhibited by mibefradil or verapamil. These
results suggest that mechanisms other than inhibition of T- and L-type calcium
channels are related to the cardioprotection observed in the presence of
verapamil. A specific action on the sarcoplasmic reticulum (ryanodine-sensitive
calcium channel) or the mitochondria may explain the efficacy of
phenylalkylamines (verapamil) in this condition.
PMID- 10686663
TI - How long can an escalation of dose override tolerance to the hypotensive efficacy
of nitroglycerin infusion in coronary care patients.
AB - Tolerance to nitroglycerin infusion (NG) can be overridden by dose escalation.
The aim of this study was to define for how long it can be done for hypotensive
efficacy of NG, in a coronary care setting. A prospective trial with an intra
individual therapeutic comparison was performed in 60 patients with acute
myocardial infarction or unstable angina. Initial efficacy of NG was confirmed by
a 10% blood pressure decrease (measured by cuff). Seventy-two-hour NG infusion
was interrupted, for 30 minutes, every 12 hours. If blood pressure increased by
10% after infusion interruption, the infusion was continued at the previous rate.
If blood pressure did not increase (detected tolerance--weakened efficacy of NG),
the dose was increased until pressure decreased by 10% and the infusion was
continued at the new dose. Failure to achieve hypotensive response, despite a 5
fold dose increase, indicated onset of resistance--completely lost hypotensive
efficacy of NG. The majority of patients (49 out of 55) who developed tolerance,
developed it during the first 36 hours, while the majority of those who developed
resistance (33 out of 40), developed it within 60 hours of the infusion.
Tolerance was overridden by dose escalation in 41 out of 55 patients, which was
repeated in 31 patients. Complete restoration of NG action was possible over 24
hours in half the patients, and over 48 hours in one third of the patients. Three
out of 34 patients who developed tolerance before the 13th hour did not develop
resistance during the following 60 hours of dose up-titration. The conclusion is
that tolerance to NG can be overridden by dose escalation in the majority of
patients for a significant period of time, which is useful in clinical practice.
PMID- 10686664
TI - Prolonged oral L-carnitine substitution increases bicycle ergometer performance
in patients with severe, ischemically induced cardiac insufficiency.
AB - Acute and chronic L-carnitine application exerts protective effects in a number
of cardiac diseases. These favourable effects are attributed to improvements of
the energy metabolism and have been found both in animal experiments and in man.
In order to investigate the effect of long-time oral L-carnitine substitution on
physical performance, 41 patients suffering from class NYHA II or III cardiac
insufficiency were recruited for a clinical study. Following the double-blind,
randomized, placebo-controlled design of the study, 20 patients were given 3 x 1
g L-carnitine daily for 120 days whereas the control group (21 patients) received
placebo. Bicycle ergometer tests were used to determine maximum performance,
systolic and diastolic blood pressure, heart rate, and ST changes. Four series of
tests were carried out: on day 0 (before the first substrate application), on the
60th and the 120th day (during L-carnitine or placebo application), and on the
180th day (60 days after the end of substitution). A significant improvement in
performance (significantly higher maximum performance during bicycle ergometry)
could be found within the carnitine group on the 60th and 120th day of L
carnitine application; and haemodynamical parameters showed a tendency to
improve, too. These effects, which were attributed to L-carnitine, could be
detected even 60 days after the end of substitution. No corresponding changes
were found in the placebo group. The findings presented in this paper support
suggestions of other authors that L-carnitine in combination with the usual
medication (digitalis, beta-blockers, calcium antagonists, nitrates) improves
performance and effort tolerance in patients with cardiac insufficiency.
Moreover, the findings suggest a favourable long-term effect, which lasts beyond
the actual L-carnitine application, on the performance of patients with advanced
cardiac insufficiency.
PMID- 10686665
TI - Efficacy of rilmenidine versus captopril on microalbuminuria: a pilot study in
hypertensive type 2 diabetics.
PMID- 10686666
TI - The effect of nebivolol on left ventricular hypertrophy in hypertension.
PMID- 10686667
TI - Experimental susceptibility of turbot Scophthalmus maximus to viral haemorrhagic
septicaemia virus isolated from cultivated turbot.
AB - Juvenile pathogen-free turbot were infected with a viral haemorrhagic septicaemia
virus (VHSV) isolate recovered from turbot cultivated on the island of Gigha,
West Scotland. Mortality of 100% was recorded in fish infected via the intra
peritoneal (i.p.) route. Horizontal transmission of VHSV in sea water was
demonstrated by cohabitation of naive fish with i.p. infected fish at a ratio of
1:1. The total cumulative average mortality in cohabiting fish was 60% by 60 d
post-infection. Turbot infected via an immersion route exhibited a cumulative
average mortality of 71% by the end of the experiment. VHSV identified by enzyme
linked immunosorbent assay (ELISA) was recovered from both organ (kidney and
spleen) and brain samples of individual fish that died following infection by all
experimental routes. These findings pose significant implications regarding the
persistence of VHSV and its role in limiting natural populations of marine fish
species. In addition, the establishment of infection models for the transmission
of VHSV in sea water is of fundamental importance to the development of anti-VHSV
vaccines in important commercial species such as turbot.
PMID- 10686668
TI - Pathogenicity of nodavirus strains from striped jack Pseudocaranx dentex and
Atlantic halibut Hippoglossus hippoglossus, studied by waterborne challenge of
yolk-sac larvae of both teleost species.
AB - The present study shows that differences in pathogenicity exist among fish
nodavirus strains. In challenge trials, a Japanese strain (SJ93Nag) was highly
virulent to larvae of the striped jack Pseudocaranx dentex but replication was
not detected in larvae of Atlantic halibut Hippoglossus hippoglossus at 6 degrees
C. Conversely, a Norwegian nodavirus strain (AH95NorA) that was highly virulent
to the Atlantic halibut larvae did not replicate in striped jack larvae at 20
degrees C. Occurrence of the disease viral encephalopathy and retinopathy (VER)
and cumulative mortality were significantly different in the 2 species when
challenged with the 2 nodavirus strains. The presence of nodavirus in nervous
tissue was monitored by immunohistochemical methods. Our results support the view
that the genetic diversity among nodavirus strains reflects the existence of
different viral phenotypes which may be adapted to infect different host species
and/or for replicating at different temperatures. Fish nodaviruses represent
surveyable pathogens well suited for studying the relation between viral
genotypic and phenotypic properties such as host specificity, temperature optima,
neuroinvasiveness and neurovirulence.
PMID- 10686669
TI - Naked DNA vaccination of Atlantic salmon Salmo salar against IHNV.
AB - A naked plasmid DNA encoding the glycoprotein (pCMV4-G) of a 1976 isolate of
infectious hematopoietic necrosis virus (IHNV) obtained from steelhead
Oncorhynchus mykiss was used to vaccinate Atlantic salmon Salmo salar against
IHNV. Eight weeks post-vaccination the fish were challenged with a strain of IHNV
originally isolated from farmed Atlantic salmon undergoing an epizootic. Fish
injected with the glycoprotein-encoding plasmid were significantly (p < 0.05)
protected against IHNV by both immersion and cohabitation challenge. Survivors of
the first challenges were pooled and re-challenged by immersion 12 wk after the
initial challenge. Significant (p < 0.05) protection was observed in all of the
previously challenged groups including those receiving the complete vaccine. Fish
injected with the glycoprotein-encoding plasmid produced low levels of virus
neutralizing antibodies prior to the first challenge. Neutralizing antibodies
increased in all groups after exposure to the IHNV. Passive transfer of pooled
sera from pCMV4-G vaccinates and IHN survivors provided relative survivals of 40
to 100% compared to fish injected with sera collected from fish immunized with
control vaccines or left unhandled. In this study, DNA vaccination effectively
protected Atlantic salmon smolts against challenges with IHNV.
PMID- 10686670
TI - Comparative severity of experimentally induced mycobacteriosis in striped bass
Morone saxatilis and hybrid tilapia Oreochromis spp.
AB - Twenty striped bass Morone saxatilis and 20 hybrid tilapia Oreochromis niloticus
x O. mossambicus x O. aureus each received a single intramuscular injection of
1.6 x 10(6) colony forming units per gram body weight of Mycobacterium marinum.
Striped bass manifested significantly greater clinical and microscopic disease
compared to tilapia. Whereas all the striped bass had died or were clinically ill
by Day 8 post-infection, there was no apparent disruption of normal behaviour,
physical appearance, or growth in any of the sacrificed or surviving tilapia.
Histologically, granulomas in striped bass were generally larger and less
discrete, with a higher proportion of heavily vacuolated macrophages, and large
cores of necrotic cells. Visceral granulomas in tilapia were smaller, with a
higher proportion of epithelioid macrophages, more pigment-containing cells, more
peripheral lymphocytes, and virtually no central necrosis. Visceral granulomas
were 18-fold more numerous in striped bass than in tilapia. Based upon
histomorphometric data, mean proportions of acid-fast bacteria within pronephros
granulomas were 4-fold greater in striped bass than tilapia, and striped bass
granulomas averaged more than twice as large as tilapia granulomas. In the
anterior kidney of striped bass, a positive correlation existed between mean
mycobacterial proportions and mean necrosis scores. In tilapia, mean
mycobacterial proportions correlated negatively with mean granuloma numbers,
whereas there was no correlation between these parameters in striped bass.
Results suggest that intrinsic functional differences in the immunologic systems
of striped bass and hybrid tilapia may contribute to inter-species variation in
mycobacteriosis susceptibility.
PMID- 10686671
TI - Infectious necrotizing enteritis and mortality caused by Vibrio carchariae in
summer flounder Paralichthys dentatus during intensive culture.
AB - An epizootic causing mortality among cultured summer flounder Paralichthys
dentatus occurred in summer of 1998 at a land-based facility on Narragansett Bay,
Rhode Island, USA. The disease, flounder infectious necrotizing enteritis (FINE),
was characterized by reddening around the anal area, distended abdomens filled
with opaque serosanguineous fluid, enteritis and necrosis of the posterior
intestine. In extreme cases of the disease, the posterior intestine was detached
from the anus and was observed coming out the vent. The intestine of individuals
that recovered from the disease ended in a blind-sac; the abdomens of these fish
were distended, due to food and water inside the intestinal blind-sac. A
bacterium was isolated from ascites fluid and kidney of moribund flounder and
identified as the causative agent in challenge experiments. The pathogen was
identified as Vibrio carchariae by morphological and biochemical characteristics
and sequence of the 16S rRNA. The LD50 estimate was 5 x 10(5) colony-forming
units injected intraperitoneally into 100 to 200 g summer flounder.
PMID- 10686672
TI - Experimental detection of the actinospores of Myxobolus pseudodispar (Myxosporea:
Myxobolidae) in oligochaete alternate hosts.
AB - The development of Myxobolus pseudodispar Gorbunova, 1936, an intracellular
myxosporean muscle parasite of the roach Rutilus rutilus L., was studied in
experimentally infected oligochaetes. In one experiment, uninfected Tubifex
tubifex Muller and Limnodrilus hoffmeisteri (Claparede) were exposed to mature
spores of M. pseudodispar. Triactinomyxon spores developed both in T. tubifex and
L. hoffmeisteri specimens. Triactinospores were first released from the
oligochaetes 76 d after initial exposure. At that time, pansporocysts containing
8 triactinospores were located in the gut epithelium of experimentally infected
oligochaetes, but free actinosporean stages were also found in their gut lumen.
Each triactinospore had 3 pyriform polar capsules and an elongated cylindrical
sporoplasm with 8 secondary cells. The spore body joined the 3 caudal projections
with a relatively long style. One of the 3 caudal projections was shorter than
the other two. The total length of the triactinospore was on average 206.5
microns.
PMID- 10686673
TI - Henneguya ghaffari sp. n. (Myxozoa: Myxosporea), infecting the Nile perch Lates
niloticus (Teleostei: Centropomidae).
AB - Light microscopical description is presented for a new myxozoan species,
Henneguya ghaffari, which infects the Nile perch Lates niloticus (Linnaeus, 1758)
in Lake Wadi El-Raiyan in Egypt. The spore is characterized by a triangular
thickening at the base of the caudal processes. The relatively long caudal
processes run adherent to each other for two-thirds of their length, then
bifurcate to very fine processes. Prevalence of infection was 34.6% and peaked
during winter and early spring. The infection was concentrated along the
intestinal tract, and in severe cases gills and gill rakers were also infected.
Histology revealed that, in contrast to findings of previously published works on
related species, intralamellar plasmodia did not develop inside the blood
capillaries of the gills. Intestinal plasmodia were very pathogenic due to their
large number and size. These plasmodia caused atrophy of the muscularis layer,
and replaced and distended the submucosal and mucosal layers. The validity of
some Henneguya species in Africa is discussed.
PMID- 10686674
TI - Absence of vertical transmission of infectious salmon anemia virus (ISAV) from
individually infected Atlantic salmon Salmo salar.
AB - Atlantic salmon Salmo salar L. eggs were collected from grilse that were
individually identified as ISAV-positive based on the detection of pathogen in
ovarian fluid by RT-PCR. The eggs were fertilised, disinfected and reared under
quarantine conditions. To address the possibility of vertical transmission,
fertilised eggs, alevins and parr were screened for the virus by SHK-1 cell
culture and RT-PCR. In addition, ISAV-negative parr were injected with
homogenates of potentially infected eyed eggs. ISAV was not detected in eyed
eggs, alevins or parr. No mortalities occurred among fish injected with the egg
homogenates. These observations suggest the absence of a vertical transmission
route for ISAV infection.
PMID- 10686676
TI - [Multiple sclerosis--a disease that never sleeps. Satellite Symposium "Multiple
sclerosis must be treated: early start of interferon therapy" within the
framework of the 72nd Annual Meeting of the German Society for Neurology.
Magdeburg, 30 September 1999].
PMID- 10686675
TI - First record of Emetha audouini, a cymothoid isopod parasite, from cultured sea
bass Dicentrarchus labrax in Greece.
AB - For the first time, Emetha audouini (Milne Edwards, 1840), a cymothoid isopod, is
reported parasitising cage cultured sea bass Dicentrarchus labrax L., 1758 in
Greece. The specimens observed are larvae (Pulli II). They were found in great
numbers in the buccal and branchial cavity of young (3.5 m.o. old) sea bass, in
an intensive cage farm facility. This parasite is certainly transferred to sea
bass from wild populations of Sparidae or Centracanthidae. Serious lesions were
visible and typical of a crustacean infection, with extensive and deep skin
damage in the head area. The cumulative mortality, over a 2 wk period, was
10.75%. The parasitic problem was successfully dealt with by optimization of
management practices rather than use of costly and dangerous chemotherapeutants.
PMID- 10686677
TI - [Challenges in epilepsy therapy: start low, go slow. 72nd Congress of the German
Society for Neurology. Topiramate--a valuable new tool for the therapy of focal
epilepsy? 1 October 1999, Magdeburg].
PMID- 10686678
TI - [Alzheimer dementia and depression--a therapeutic challenge. In comorbidity they
burden the Alzheimer patient as well as his caretakers].
PMID- 10686679
TI - [The cardiologist and first aid: the situation in Italy].
PMID- 10686680
TI - The experience of chest pain units.
PMID- 10686681
TI - [Is it possible to reformulate the strategic approach to chest pain in Italy
today?].
PMID- 10686682
TI - [Organizational strategy for cardiac emergencies during the 2000 Jubilee].
PMID- 10686684
TI - Prehospital fibrinolysis.
PMID- 10686683
TI - [The avoidable delay].
PMID- 10686685
TI - [Hospital network for primary PTCA: the Italian situation].
PMID- 10686686
TI - Prehospital triage and reperfusion therapy for acute myocardial infarction.
PMID- 10686687
TI - [Prognostic stratification].
PMID- 10686688
TI - [Management of acute coronary syndrome. New pharmacologic approaches].
PMID- 10686689
TI - [Role of revascularization in acute coronary syndrome].
PMID- 10686690
TI - The management of cardiogenic shock.
PMID- 10686691
TI - [The first two links of the "survival chain": the 118 system and early emergency
care].
PMID- 10686692
TI - [The third and fourth link of the chain: defibrillation and advanced support].
PMID- 10686693
TI - [Is it possible to identify patients at risk of sudden cardiac death?].
PMID- 10686694
TI - [Intervention tools in patients at risk of fatal arrhythmia: medical treatment or
ICD. Indicators and results].
PMID- 10686695
TI - [Life Project: the first European project of early defibrillation with first
responders].
PMID- 10686696
TI - [Dimensions of the educational problem].
PMID- 10686697
TI - [Role of national health institutions and of professional societies].
PMID- 10686698
TI - [Medical-scientific information].
PMID- 10686699
TI - [Continuing education: legislative basis for a possible development].
PMID- 10686700
TI - [Cardiovascular treatment: point of view of the cardiologist and the controlling
body].
PMID- 10686701
TI - [Thrombolytic therapy in the year 2000].
PMID- 10686702
TI - [Fight against sudden death in Italy: what can be done and what should be done].
PMID- 10686703
TI - National Committee for the Coordination of Antibiotic Policy in Belgium: the next
step in the fight against antimicrobial resistance.
PMID- 10686704
TI - Prevention of pneumococcal disease: an update on the Belgian Consensus Report.
AB - An ad hoc working party on pneumococcal vaccine with representatives of the
Belgian Society for Infectiology and Clinical Microbiology, the Belgian Society
of Pulmonology and Scientific Societies of General Practitioners reviewed new
data on the epidemiology of S. pneumoniae infections in Belgium, on the efficacy
and the cost-effectiveness of the 23-valent capsular polysaccharide vaccine. We
discuss recent data on vaccination with a new conjugate pneumococcal vaccine,
shown to be highly effective in children. The Working Group of the Belgian
Scientific Societies endorses the recommendations issued by the Hoge
Gezondheidsraad in 1993 and described in a consensus report in 1996.
PMID- 10686705
TI - Glycaemic and blood pressure controls achieved in a cohort of 318 patients with
type 2 diabetes.
AB - The aim of the study was to evaluate the current antihyperglycaemic and
antihypertensive treatment schemes as well as the quality of metabolic control
and blood pressure in a population with type 2 diabetes, in view of the United
Kingdom Prospective Diabetes Study (UKPDS) data. 318 patients were included. 44%
were treated with metformin and/or sulfonylurea. 44% received insulin in
monotherapy or combined with oral drugs. HbA1c was 8.0 (7.9-9.4)% (median;
percentiles 25-75). Chronic neurological and vascular (micro- and
macroangiopathy) complications were present in 21-43% of patients and were
related to glycaemic control. (Un)treated hypertension was found in 59% of
patients. Main treatments were ACE-inhibitors (40%), calcium channel antagonists
and diuretics (20%) and/or beta-blockers (18%). Systolic and diastolic blood
pressure were 147 +/- 22 and 86 +/- 12 mm/Hg (mean +/- 1 SD). In conclusion,
overall glycaemic control of a type 2 diabetic population remains slightly
unsatisfactory in view of the UKPDS recommendations. In contrast, blood pressure
control was adequate.
PMID- 10686706
TI - [Endocrine complications of genetic hemochromatosis].
AB - The authors report the prevalence and severity of endocrine complications in a
cohort of 115 patients suffering form genetic hemochromatosis and followed since
two decades. Already 40% of them had developed diabetes at the time of diagnosis
of hemochromatosis, which was made at the age of 50 +/- 12 years (m +/- SD).
Hypogonadism was evidenced in 42% of the patients. In most of them, it was
considered as secondary to pituitary lesions as assessed by GnRH tests. No other
endocrine complications, in particular thyroid disease, were evidenced during
follow up. On the other hand, it was also of interest to note that liver
cirrhosis was observed in 52% of the patients at the time of hemochromatosis
diagnosis. A relationship between cirrhosis, diabetes and hypogonadism was also
assessed in these patients. We conclude to the still high prevalence of endocrine
complications in genetic hemochromatosis.
PMID- 10686707
TI - Persisting misconceptions of Belgian physicians and nurses about cancer pain
treatment.
AB - In Belgium palliative hospices, palliative support teams in hospitals and
palliative home care are well-developed. The author gave a lecture about pain
treatment in palliative care and inquired after the knowledge and attitudes of 28
nurses and 45 physicians. A questionnaire containing questions about morphine and
cancer pain treatment was completed by the attendees before and after the
session. In the initial questionnaire the care-providers' attitudes towards
palliative care and symptom control were included also. The Wilcoxon test
revealed a significant difference in knowledge between the physicians and nurses
before the session (p = 0.007). Afterwards knowledge had improved in both groups
(p = 0.007) but a difference still remained (p = 0.007). This study reveals that
continued education is mandatory. An oral presentation seems not ideal;
interactive training with practical exercises might be more appropriate.
PMID- 10686708
TI - Diagnosis and treatment of an unusual cause of metabolic acidosis: ethylene
glycol poisoning.
AB - Ethylene glycol intoxication is a rare but dangerous type of poisoning. It causes
a severe acidosis with high anion and osmolal gaps. Clinical manifestations of
the ethylene glycol intoxication can be divided in three phases: a neurologic
stage, with hallucinations, stupor and coma; the second stage is cardiovascular
with cardiac failure. Renal failure characterizes the third stage, due to acute
tubular necrosis. After aggressive gastric emptying, the main treatment is
ethanol or 4-methypyrazole, which can be given either orally or intravenous, with
supportive measures for all symptoms or diseased organ.
PMID- 10686709
TI - Acromegaly and Waldenstrom's macroglobulinaemia.
PMID- 10686710
TI - [Thrombocytopenia and lupus].
PMID- 10686711
TI - [Idiopathic thrombocytopenic purpura as first manifestation of systemic lupus
erythematosus lupus].
AB - OBJECTIVES: We studied SLE whose initial symptoms were related to idiopathic
thrombocytopenic purpura (ITP) in order to determine if they share clinical and
immunologic manifestations. METHODS: We reviewed the clinical backgrounds of 150
SLE (according to the ACR criteria) periodically followed from 1980 until 1998.
We found 12 patients with both these conditions. RESULTS: All patients were
female with a mean age of 32 at the time of ITP diagnosis and 36 at the time of
SLE diagnosis. The most usual clinical manifestations were: arthritis (92%),
cutaneous (58%) and hematologic involvement with lymphopenia (58%) and
thrombocytopenia again (33%) after the initial ITP episode, always together with
autoimmune hemolytic anemia (Evans syndrome). None of these patients presented
with neurologic involvement and only one presented with renal involvement. 50%
were positive for anti-DNA antibodies, 50% were Ro(+) and 16% were RNP (+). 66%
were positive for antiphospholipid antibodies and 33% for lupus anticoagulant.
Thrombocytopenia was controlled just with steroids in only 16% of the patients.
Splenectomy controlled thrombocytopenia with complete remission achieved in 80%
(4 from 5) of the patients and 20% (1 from 5) were refractory to this therapy
after a medium follow-up time of 6.5 years. CONCLUSIONS: 1) SLE whose initial
symptoms are related to ITP were characterized by joints, cutaneous and
hematologic involvement without renal and neurologic manifestations. 2)
Splenectomy was able to control refractory thrombocytopenia in the majority of
these patients.
PMID- 10686712
TI - [Secondary amyloidosis in rheumatoid arthritis. A clinical study of 29 patients].
AB - BACKGROUND: To study the clinical features, outcome and response to therapy in 29
cases of rheumatoid arthritis (RA) with secondary amyloidosis (AA). PATIENTS AND
METHOD: Twenty-nine patients with RA and AA who were diagnosed during 11 years.
RESULTS: The mean age and the mean duration of RA were 63 +/- 12 years and 15 +/-
7 years respectively. The most common initial clinical feature was renal
involvement (83%). Nineteen patients were treated with methotrexate. The mean
survival time was 42 +/- 8 months. Eleven patients (38%) have deceased.
CONCLUSION: Our data confirms that AA in RA is a serious complication with a
bleak prognosis. A normal renal function is a good prognosis indicator.
PMID- 10686714
TI - [Pernicious anemia and other megaloblastic anemias].
AB - OBJECTIVE: To describe the clinical and biological characteristics of a series of
patients with megaloblastic anemia (MA) and to identify potential differences
between patients with pernicious anemia (PA(+)) and patients with other MA (PA(
)). METHOD: Retrospective study of 50 patients with MA diagnosed in our service
between 1993 and 1998. RESULTS: MA was diagnosed in 50 patients. The median age
in the moment of diagnosis was 70.7 years. The causes of MA were: cobalamin
deficiency (CD) in 40 cases (80%), folate deficiency (FD) in 7 cases (14%) and
both deficiencies in 3 cases (6%). PA was diagnosed in 19 patients (38%). All
cases showed hyper-segmented neutrophils and 41 cases (81%) macroovalocytosis.
Hemoglobin level < 8 g/dl was present in 22 patients (44%). The median serum LDH
level was 2.059 +/- 1.739 U/l. There was a lower frequency of female sex and a
higher RDW in the group PA(+). There were no significant differences between both
groups in the rest of studied features, except for the presence of antiparietal
cell antibodies and anti-intrinsic factor antibodies in the group PA(+).
CONCLUSIONS: CD was the most frequent cause of MA in our series. PA was the most
frequent cause of CD. Most cases of MA corresponded to a severe macrocytic anemia
with hyper-segmented neutrophils, macroovalocytosis and very high serum LDH
level. We did not identify any clinical or biological characteristic, except for
the presence of antiparietal cell antibodies and anti-intrinsic factor antibodies
and a higher RDW in the group PA(+), to permit distinguish the groups PA(+) and
PA(-).
PMID- 10686713
TI - [Efficacy of hygienic and dietary therapy in coronary patients with isolated
hypoalphalipoproteinemia].
AB - OBJECTIVE: Hypoalphalipoproteinemia (HA) is a relatively frequent disorder found
in patients with coronary artery disease (CAD). It is associated to a greater
risk of suffering recurrent coronary episodes and of mortality caused by this
disease. METHODS: We selected 60 patients with previous CAD and isolated HA (HDLc
concentration < 0.9 mmol/L, and desirable lipidic profile) that were
consecutively seen in a specialized lipid clinic. Subjects were randomly included
in the two groups of cases (group of intervention) and controls. Cases were
treated with non-pharmacological measures which included changes in lifestyle and
dietary habits. Control subjects were referred to their general practitioners in
order to receive conventional medical care. RESULTS: It was demonstrated a
significant increase in the HDLc concentration in both groups, being greater the
improvement in the group of intervention, but the differences in the increase in
the HDLc between both groups were not significant. Fibrinogen was lower in the
patients of the group of intervention, especially in those patients that gave up
smoking. CONCLUSION: Changes in lifestyle and dietary habits are useful to
correct the low HDLc plasma levels and to reduce fibrinogen levels in those
patients with CAD and HA.
PMID- 10686715
TI - [Gronblad-Strandberg syndrome. Report of four cases in one family].
AB - The Gronblad-Strandberg syndrome is a rare congenital hereditary dysplasic
disorder of the connective tissue, characterized by a progressive abnormal
mineralization and dystrophic calcification of elastic tissue and collagen. This
process affects tissues rich in elastic fibers and multiple systems of the
organism, the cutaneous, ocular and vascular being the most common. These
findings progress through the life of the affected person. We present 4 cases in
the same family, with heterogeneous clinic pattern and evolution.
PMID- 10686716
TI - [Endocarditis caused by Actinobacillus actinomycetemcomitans].
AB - The HACEK group endocarditis are infrequent in general population. They usually
develop subacute endocarditis with large vegetations, peripheral emboli, heart
failure, requiring frequent valvular replacement. We report a clinical case of
endocarditis caused by Actinobacillus actinomycetemcomitans (AA), without the
typical findings of the HACEK group endocarditis and with a successful evolution
with medical treatment.
PMID- 10686717
TI - [Cellulitis caused by Aeromonas hydrophila].
AB - We report the case of a cirrhotic patient with leukocytoclastic vasculitis who
developed a rapid and progressive cellulitis with hemorrhagic bulla and sepsis
due to Aeromonas hydrophila, the portal of entry was the surgical leech of a
cutaneous biopsy.
PMID- 10686718
TI - [Pasteurella spp: a new microorganism to the cause of acute suppurative
thyroiditis].
AB - Acute suppurative thyroiditis is an uncommon disease due to local resistance of
the gland to infection. Preexisting gland pathology and local anatomic
abnormalities are predisposing factors. We present the first case described in
the medical literature caused by Pasteurella spp after upper respiratory
infection with insidious manifestations resembling subacute thyroiditis. The
course was benign after surgical drainage.
PMID- 10686719
TI - [Gronblad-Strandberg syndrome].
AB - The Gronblad-Strandberg syndrome, also known as pseudoxanthoma elasticum, is a
rare congenital dysplasic disorder of the connective tissue, characterized by a
progressive abnormal mineralization and dystrophic calcification of elastic
tissues and collagen (1). The mode of inheritance is uncertain, but autosomal
recessive inheritance can be assumed. This process affects tissues rich in
elastic fibres and multiple systems of the organism, being the most common the
cutaneous (pseudoxanthoma elasticum), ocular (angioid streaks), vascular
(occlusive vascular disease) and gastrointestinal manifestations. These findings
progress through the life of the affected person, with variable pattern clinic
and evolution.
PMID- 10686720
TI - [Prions: definition and diseases].
AB - In this article we review the concept and terminology of prions, their
replication and some current hypothesis on the nature of these infectious agents
causing neurodegenerative diseases. This revision also summarizes the
etiopathogenic, epidemiological, clinical and neuropathological features of the
prion diseases or human transmissible spongiform encephalopathies, and some
methods for their early diagnosis. Finally, we discuss the possible link between
the bovine spongiform encephalopathy and the new cases of Creutzfeldt-Jakob
disease identified in the United Kingdom.
PMID- 10686721
TI - [Itraconazole in the treatment of invasive aspergillosis. A case report].
PMID- 10686722
TI - [A new case of association of multiple myeloma and megaloblastic anemia].
PMID- 10686723
TI - [Multiple myeloma and megaloblastic anemia].
PMID- 10686724
TI - [Herpetic tracheobronchitis in a patient with the acquired immunodeficiency
syndrome].
PMID- 10686725
TI - [Mucinous cystadenocarcinoma of the recto-appendiceal fistula].
PMID- 10686726
TI - [Primary and secondary prophylaxis of venous thrombotic disease in neoplastic
patients].
PMID- 10686727
TI - [Umbilical metastasis of mucinous adenocarcinoma of the colon diagnosed by fine
needle aspiration cytology].
PMID- 10686728
TI - Poverty and inequity: a proper focus for the new century.
PMID- 10686729
TI - Health inequalities and the health of the poor: what do we know? What can we do?
AB - The contents of this theme section of the Bulletin of the World Health
Organization on "Inequalities in health" have two objectives: to present the
initial findings from a new generation of research that has been undertaken in
response to renewed concern for health inequalities; and to stimulate movement
for action in order to correct the problems identified by this research. The
research findings are presented in the five articles which follow. This Critical
Reflection proposes two initial steps for the action needed to alleviate the
problem; other suggestions are given by the participants in a Round Table
discussion which is published after these articles. The theme section concludes
with extracts from the classic writings of the nineteenth-century public health
pioneer, William Farr, who is widely credited as one of the founders of the
scientific study of health inequalities, together with a commentary. This
Critical Reflection contributes to the discussion of the action needed by
proposing two initial steps for action. That professionals who give very high
priority to the distinct but related objectives of poverty alleviation,
inequality reduction, and equity enhancement recognize that their shared concern
for the distributional aspects of health policy is far more important than any
differences that may divide them. That health policy goals, currently expressed
as societal averages, be reformulated so that they point specifically to
conditions among the poor and to poor-rich differences. For example, infant
mortality rates among the poor or the differences in infant mortality between
rich and poor sectors would be more useful indicators than the average infant
mortality rates for the whole population.
PMID- 10686730
TI - Socioeconomic inequalities in child mortality: comparisons across nine developing
countries.
AB - This paper generates and analyses survey data on inequalities in mortality among
infants and children aged under five years by consumption in Brazil, Cote
d'Ivoire, Ghana, Nepal, Nicaragua, Pakistan, the Philippines, South Africa, and
Viet Nam. The data were obtained from the Living Standards Measurement Study and
the Cebu Longitudinal Health and Nutrition Survey. Mortality rates were estimated
directly where complete fertility histories were available and indirectly
otherwise. Mortality distributions were compared between countries by means of
concentration curves and concentration indices: dominance checks were carried out
for all pairwise intercountry comparisons; standard errors were calculated for
the concentration indices; and tests of intercountry differences in inequality
were performed.
PMID- 10686731
TI - Inequality of child mortality among ethnic groups in sub-Saharan Africa.
AB - Accounts by journalists of wars in several countries of sub-Saharan Africa in the
1990s have raised concern that ethnic cleavages and overlapping religious and
racial affiliations may widen the inequalities in health and survival among
ethnic groups throughout the region, particularly among children. Paradoxically,
there has been no systematic examination of ethnic inequality in child survival
chances across countries in the region. This paper uses survey data collected in
the 1990s in 11 countries (Central African Republic, Cote d'Ivoire, Ghana, Kenya,
Mali, Namibia, Niger, Rwanda, Senegal, Uganda, and Zambia) to examine whether
ethnic inequality in child mortality has been present and spreading in sub
Saharan Africa since the 1980s. The focus was on one or two groups in each
country which may have experienced distinct child health and survival chances,
compared to the rest of the national population, as a result of their
geographical location. The factors examined to explain potential child survival
inequalities among ethnic groups included residence in the largest city,
household economic conditions, educational attainment and nutritional status of
the mothers, use of modern maternal and child health services including
immunization, and patterns of fertility and migration. The results show
remarkable consistency. In all 11 countries there were significant differentials
between ethnic groups in the odds of dying during infancy or before the age of 5
years. Multivariate analysis shows that ethnic child mortality differences are
closely linked with economic inequality in many countries, and perhaps with
differential use of child health services in countries of the Sahel region.
Strong and consistent results in this study support placing the notion of
ethnicity at the forefront of theories and analyses of child mortality in Africa
which incorporate social, and not purely epidemiological, considerations.
Moreover, the typical advantage of relatively small, clearly defined ethnic
groups, as compared to the majority in the national population, according to
fundamental indicators of wellbeing--child survival, education, housing, and so
forth--suggests that many countries in sub-Saharan Africa, despite their
widespread poverty, are as marked by social inequality as are countries in other
regions in the world.
PMID- 10686732
TI - Defining and measuring health inequality: an approach based on the distribution
of health expectancy.
AB - This paper proposes an approach to conceptualizing and operationalizing the
measurement of health inequality, defined as differences in health across
individuals in the population. We propose that health is an intrinsic component
of well-being and thus we should be concerned with inequality in health, whether
or not it is correlated with inequality in other dimensions of well-being. In the
measurement of health inequality, the complete range of fatal and non-fatal
health outcomes should be incorporated. This notion is operationalized through
the concept of healthy lifespan. Individual health expectancy is preferable, as a
measurement, to individual healthy lifespan, since health expectancy excludes
those differences in healthy lifespan that are simply due to chance. In other
words, the quantity of interest for studying health inequality is the
distribution of health expectancy across individuals in the population. The
inequality of the distribution of health expectancy can be summarized by measures
of individual/mean differences (differences between the individual and the mean
of the population) or inter-individual differences. The exact form of the measure
to summarize inequality depends on three normative choices. A firmer
understanding of people's views on these normative choices will provide a basis
for deliberating on a standard WHO measure of health inequality.
PMID- 10686733
TI - Inequalities in health care use and expenditures: empirical data from eight
developing countries and countries in transition.
AB - This paper summarizes eight country studies of inequality in the health sector.
The analyses use household data to examine the distribution of service use and
health expenditures. Each study divides the population into "income" quintiles,
estimated using consumption expenditures. The studies measure inequality in the
use of and spending on health services. Richer groups are found to have a higher
probability of obtaining care when sick, to be more likely to be seen by a
doctor, and to have a higher probability of receiving medicines when they are
ill, than the poorer groups. The richer also spend more in absolute terms on
care. In several instances there are unexpected findings. There is no consistent
pattern in the use of private providers. Richer households do not devote a
consistently higher percentage of their consumption expenditures to health care.
The analyses indicate that intuition concerning inequalities could result in
misguided decisions. It would thus be worthwhile to measure inequality to inform
policy-making. Additional research could be performed using a common methodology
for the collection of data and applying more sophisticated analytical techniques.
These analyses could be used to measure the impact of health policy changes on
inequality.
PMID- 10686734
TI - Public spending on health care in Africa: do the poor benefit?
AB - Health care is a basic service essential in any effort to combat poverty, and is
often subsidized with public funds to help achieve that aim. This paper examines
public spending on curative health care in several African countries and finds
that this spending favours mostly the better-off rather than the poor. It
concludes that this targeting problem cannot be solved simply by adjusting the
subsidy allocations. The constraints that prevent the poor from taking advantage
of these services must also be addressed if the public subsidies are to be
effective in reaching the poor.
PMID- 10686735
TI - Round table discussion. Health inequalities and the health of the poor.
PMID- 10686736
TI - Equality, equity: why bother?
PMID- 10686737
TI - Overcoming inequity means finding approaches that work
PMID- 10686738
TI - Combining forces against inequity and poverty rather than splitting hairs
PMID- 10686739
TI - Efficient equity-oriented strategies for health
PMID- 10686740
TI - Equity and gender
PMID- 10686741
TI - Understanding and setting up the process for health equity
PMID- 10686742
TI - The key to overcoming inequality is political commitment
PMID- 10686743
TI - William Farr's legacy to the study of inequalities in health.
AB - This section looks back to some of the ground-breaking contributions to public
health, reproducing them in their original form and adding a commentary on their
significance from a modern-day perspective. To complement this month's theme
issue of the Bulletin, Margaret Whitehead assesses the importance of William
Farr's contribution to the study of social inequalities in health.
PMID- 10686744
TI - Cost-effectiveness of iron supplementation and malaria chemoprophylaxis in the
prevention of anaemia and malaria among Tanzanian infants.
AB - Prerequisites for effective interventions against severe anaemia and malaria
among infants are economic evaluations to aid the setting of priorities and the
making of health policy. In the present study we analysed the cost and
effectiveness of three control strategies hypothetically delivered through the
Expanded Programme on Immunization (EPI). For the prevention of severe anaemia
and from the perspective of the health provider, the cost-effectiveness ratios
were, respectively, US$ 8, US$ 9, and US$ 21 per disability-adjusted life year
(DALY) for malaria chemoprophylaxis with Deltaprim (a combination of 3.125 mg
pyrimethamine and 25 mg dapsone) + iron, Deltaprim alone, or iron supplementation
alone. For malaria prevention, Deltaprim + iron cost US$ 9.7 per DALY and
Deltaprim alone cost US$ 10.2 per DALY. From a sociocultural perspective the cost
effectiveness ratios ranged from US$ 9 to US$ 26 for severe anaemia prevention
and from US$ 11 to US$ 12 for the prevention of clinical malaria. These ratios
were highly cost-effective, as defined by the World Bank's proposed threshold of
less than US$ 25 per DALY for comparative assessments. Furthermore, all the
preventive interventions were less costly than the current malaria and anaemia
control strategies that rely on clinical case management. This economic analysis
supports the inclusion of both malaria chemoprophylaxis and iron supplementation
delivered through EPI as part of the control strategies for these major killers
of infants in parts of sub-Saharan Africa.
PMID- 10686745
TI - Deterioration in the nutritional status of young children and their mothers in
Brazzaville, Congo, following the 1994 devaluation of the CFA franc.
AB - The effects of the January 1994 devaluation of the African Financial Community
(CFA) franc on the nutritional situation of the populations concerned has been
little documented. We report in this article on two nutritional cross-sectional
surveys that were conducted before and after this devaluation (1993 and 1996) in
two districts of Brazzaville, Congo. The surveys involved a representative sample
of 4206 households with a child aged 4-23 months. Complementary feeding practices
and the anthropometric indices of the children and their mothers were compared,
adjusting for changes in household socioeconomic characteristics. The results
show a decline in the quality of the first complementary foods offered to the
infants, i.e. less frequent use of special transitional foods and imported
complementary flours (of higher nutritional quality), and preparation of less
nutritious local gruels. Overall, the nutritional situation had deteriorated,
with greater levels of stunting and wasting among children, mothers with lower
body mass index, and infants with reduced birth weights. Increased food prices
would appear to be the direct cause of the decreased quality in complementary
feeding, but factors other than the devaluation have also had an impact on
household welfare. The influence of these factors on nutritional-status is
discussed.
PMID- 10686746
TI - Detection of trypanosomes in suspected sleeping sickness patients in Uganda using
the polymerase chain reaction.
AB - Diagnosis of sleeping sickness (trypanosomiasis) is difficult because of the
fluctuating levels of parasitaemia encountered in patients. In the present study
we found that the polymerase chain reaction (PCR) demonstrated trypanosome
infection in 20 out of 35 (57.1%) blood samples and in 21 out of 34 (61.7%)
cerebrospinal fluid (CSF) samples collected from an area endemic for sleeping
sickness in north-west Uganda. A total of 14 blood samples and 13 CSF samples
that were positive for trypanosomes by double centrifugation were also positive
by PCR, demonstrating good concordance between the two methods. However, 6
(28.6%) of the 21 blood samples that were parasitologically negative were
positive by PCR, while 8 (38.0%) out of 21 CSF samples that were negative by
double centrifugation were positive by PCR. These 14 negative samples could
therefore be from sleeping sickness cases even though a positive PCR test is not
evidence for the presence of trypanosomes. Furthermore, of these 8 CSF samples, 4
had been designated as early cases, based on the absence of trypanosomes and on a
count of < or = 5 white blood cells (WBC) per microliter. This suggests that some
late-stage cases could potentially be missed according to the present criteria,
and it is therefore important to perform clinical trials to determine whether
these cases could be treated successfully with the first-stage drug alone. The
remaining four CSF samples had been classified as late-stage cases, based on a
count of > 6 WBC per microliter, even though trypanosomes could not be detected
in these samples by either double centrifugation or PCR. A cut-off point of 5 WBC
per microliter, which is used as a rule of thumb to stage sleeping sickness
patients, seems to leave some late-stage cases undetected since trypanosomes were
detected in four CSF samples from suspected cases with < 5 WBC per microliter.
PMID- 10686747
TI - Health system reform and the role of field sites based upon demographic and
health surveillance.
AB - Field sites for demographic and health surveillance have made well-recognized
contributions to the evaluation of new or untested interventions, largely through
efficacy trials involving new technologies or the delivery of selected services,
e.g. vaccines, oral rehydration therapy and alternative contraceptive methods.
Their role in health system reform, whether national or international, has,
however, proved considerably more limited. The present article explores the
characteristics and defining features of such field sites in low-income and
middle-income countries and argues that many currently active sites have a
largely untapped potential for contributing substantially to national and
subnational health development. Since the populations covered by these sites
often correspond with the boundaries of districts or subdistricts, the strategic
use of information generated by demographic surveillance can inform the
decentralization efforts of national and provincial health authorities. Among the
areas of particular importance are the following: making population-based
information available and providing an information resource; evaluating
programmes and interventions; and developing applications to policy and practice.
The question is posed as to whether their potential contribution to health system
reform justifies arguing for adaptations to these field sites and expanded
investment in them.
PMID- 10686748
TI - Anthropological perspectives on injections: a review.
AB - Qualitative studies from developing countries have pointed to the widespread
popularity of injections. In addition to their use by formal and informal
providers and traditional healers, there is now increasing evidence of the use of
injections and injection equipment by lay people. Epidemiological research links
the large number of unsafe injections to serious bloodborne infections such as
viral hepatitis B and C and acquired immunodeficiency syndrome (AIDS). The
present article examines the reasons behind the demand for injections by
consumers and the administration of unnecessary or unsafe injections by different
types of provider. Interventions aimed at reducing the risk of unsafe injections
are discussed in relation to cultural and social factors as well as those factors
associated with health systems. Suggestions are made for approaches to the design
of such interventions.
PMID- 10686749
TI - A new paradox: drugs too cheap to stay available.
PMID- 10686750
TI - Unified terminology for pathology of the cervix.
PMID- 10686751
TI - Toward a lexicon of population health.
AB - Despite its undeniable currency in research and policy circles, there remains
considerable confusion about what 'population health' is. We propose a lexicon
for population health in the hope of clarifying issues and advancing this
important research emphasis and policy agenda. It distinguishes population health
in its literal meaning from a population health perspective, population health
research, a population health framework, and a population health approach to
policy. Population health is more than just thinking in aggregate terms or about
identifying vulnerable or at-risk subpopulations. A population health perspective
is fundamentally concerned with the social nature of health influences. The
social structures that shape health experiences transcend the characteristics or
actions of any one individual, providing population health with analytic
advantages over individualistic-oriented approaches to health and to health
policy.
PMID- 10686752
TI - Collective lifestyles as the target for health promotion.
AB - The last five years have witnessed intense debate among health researchers in
Canada regarding the overlap of the health promotion and population health
discourses. Meanwhile, strong currents within health promotion have attempted to
move the field beyond a focus on individual behaviour towards the influence of
social environments on health, although the tendency is often to fall back on
individual behaviour modification as the primary lever for change. The Population
Health research agenda bypasses behavioural determinants of health and explores
instead social determinants. This body of knowledge provides useful insight for
addressing some of the tensions in the health promotion discourse. This paper
explores two of these tensions: whether individuals at risk or general
populations should be targeted for change; and whether lifestyle is an individual
or a collective attribute. We propose the notion of collective lifestyles as a
heuristic for understanding the interaction between social conditions and
behaviour in shaping health.
PMID- 10686753
TI - Population health promotion: responsible sharing of future directions.
AB - Population health promotion illustrates most robustly that health is a shared
responsibility. Improving our understanding of the social production of health
and the purchase population health promotion has on shaping social welfare policy
presents a number of challenges to the future development of this discourse.
Three are briefly discussed in this paper. First is the matter of language we use
to describe our understanding of processes and influences. Second is the
conceptualization of the pathways that shape population health status. Finally,
cultural practices both extant and required to improve health status and reduce
inequalities are addressed.
PMID- 10686754
TI - Different wor(l)ds: three approaches to health research.
AB - This article describes three approaches to research in the social sciences:
positivist, interpretivist and critical social science. It uncovers some of the
philosophical assumptions these approaches adhere to and situates the discussion
in the population health arena with respect to these assumptions. The issues
under debate are as yet unsolved (and perhaps unsolvable), with long histories in
philosophy and sophisticated rationales on all sides. The article advocates
defining the underlying terms of discussion and making assumptions explicit to
facilitate dialogue, and also encourages exploration of and tolerance for other
approaches.
PMID- 10686755
TI - Indicators that count! Measuring population health at the community level.
AB - We begin with a discussion of some vitally important conceptual and
methodological issues. These issues concern our understanding of community, of
health, of population health and its determinants, of the concept of
'measurement' and the values that underlie it, and our reasons for wishing to
measure these constructs. We then present a framework for indicator categories,
propose some criteria for indicator selection and suggest an initial set of core
indicators. This indicator set reflects not simply health status--no matter how
broadly defined--but also the environmental, social and economic determinants of
health and the "healthfulness" of the community itself. Our most important
conclusion is that if the information that is contained in the data of the
indicator set is to be transformed into knowledge that can empower and emancipate
the community, it has to be developed in consultation with the local community
and local users of the information.
PMID- 10686756
TI - From concept to practice: including the social determinants of health in
environmental assessments.
AB - The present paper examines the historical evolution of health impact assessments
as part of the environmental assessment process. The development of a coherent
public health framework must be based on the model of determinants of health,
integrating toxic and infectious risks and social impacts of projects. The
integration of common concepts, processes and methodologies from the area of
public health and social impact assessment challenges the quantitative model
approach to risk assessment. The expert-driven risk assessment is transformed
into a social learning process where local knowledge and scientific input foster
a dialogue among stakeholders. The issue-oriented, iterative and participative
assessment process may be applied to the health impact assessment of public
policies. Sustainable development with its social objectives of empowerment,
participation, equity, poverty alleviation, social cohesion, population stability
and institutional development is an appropriate framework for conducting health
impact assessments.
PMID- 10686757
TI - Health, environmental assessments and population health: tools for a complex
process.
AB - Place is more than physical and natural environment. The role of biophysical
environment has still to be articulated in population health discourse and its
relations with human health are fraught with scientific uncertainty and
dissension. An environmental impact assessment (EA) evaluates the environmental
effects of a proposal--a rational and technical process. Sometimes health
assessments are included, usually by quantitative risk assessments which are
subject to the limits of scientific knowledge and bedevilled by data limitations.
The goal must be to add health to the process, yet the relevant features to
include are complex. Impacts are non-specific and they interact and have spatial
and temporal characteristics. To integrate environment into population health,
there is a need for a physical environment-health database and inter-sectorial
policy and action. There is also a need for different types of indicators to
measure process, impact and effectiveness, and for new tools (stories,
photography) to account for context and values.
PMID- 10686758
TI - British Columbia's health reform: "new directions" and accountability.
AB - The health policy New Directions committed the British Columbia government to a
population health perspective and extensive community involvement in the health
services reform process. The policy envisaged elected citizen boards with
authority to raise revenues and exercise a significant degree of local autonomy.
Academic and public attention has been paid to the decision in November 1996 to
collapse New Directions' two-tier governance structure into a single level. Less
attention has been paid to the profound changes that occurred prior to the
government's reversal on the question of governance. This paper focuses on those
changes. During the critical three years between the 1993 launch of the reform
and its formal revision in 1996, the government's positions on elections,
taxation power, local autonomy and scope of action for regional boards all
changed. Those changes marked a retreat from political accountability to the
community and an advance towards managerial accountability to the government.
PMID- 10686759
TI - Factors that facilitated and challenged the development of health goals and
targets: the British Columbia experience.
AB - Health promotion research and practice reveal that goal setting and monitoring
have gained increased acceptance at international, national, provincial/state,
regional and local levels. The global adoption of health goals as a strategy for
population health promotion has occurred even though few protocols or guidelines
to support the health goals development process have been published. Limited
study has occurred on the variation in approach to health goals planning, or on
the complex, multiple forces that influence the development process. This paper
describes conclusions drawn from an exploratory and descriptive case study that
tracked the pathways to health goals in British Columbia (BC) and uncovered
nearly 100 factors that influenced the final version of health goals adopted by
the government of BC. Influencing factors included: (a) positive perceptions of
the benefits of health goals, (b) the role of a trusted health goals champion,
(c) positioning of the goals as government rather than health ministry goals, (d)
the format and agenda of the health goals consulting process, and (e) political
reluctance toward highly specific or measurable goals with targets.
PMID- 10686760
TI - Achieving population health goals: perspectives on measurement and implementation
from Australia.
AB - Health goals and targets have been widely used to indicate strategic direction
and priority for health improvement on a population basis. This paper provides an
overview of Australia's experience in using health targets and considers the
relevance of this experience for Canada. It gives special attention to the
challenge of developing a broadly based set of targets that reflect the social,
economic and environmental determinants of health alongside more traditional
measures of health status. It examines how the technical challenge of
measurement, the bureaucratic barriers between government departments, and the
political conservatism inherent in federal systems of government present
formidable barriers to effective action on comprehensive national health targets.
The paper concludes with a reminder of the need for inter-sectorial action to
address the determinants of health. Based on the Australian experience, it
suggests for Canada an ideal combination of a national population health
framework to guide direction and priority, to be implemented through action at a
more local level, through well-defined partnerships.
PMID- 10686761
TI - Understanding the determinants of health: key decision makers in Saskatchewan
Health districts and Saskatchewan Health, 1998.
AB - This research inquiry used qualitative and quantitative methods to examine how
key decision makers from Saskatchewan health districts and Saskatchewan Health
understand the determinants of health. The inquiry was based on the premise that
key decision makers' understanding of the determinants of health, and the
consensus regarding these understandings, hinder or facilitate dialogue, choice
of effective strategies, and achievement of health promotion goals. Interviews
indicated variation in perspective and emphasis regarding how key decision makers
understand the determinants of health. A survey of key decision makers found: 1)
inconsistencies in respondents' understanding of the determinants of health,
particularly between stated beliefs and priorities for actions; and 2) that the
degree of consensus among decision makers was higher for stated beliefs and lower
for choices of action. Results indicate a need for clarification and consensus
building processes concerning the determinants of health, as well as for clear
policies that foster consistency between beliefs and actions and minimize
inappropriate or undesirable differences in interpretations.
PMID- 10686762
TI - The 'people assessing their health' (PATH) Project: tools for community health
impact assessment.
AB - The People Assessing Their Health (PATH) Project was designed to provide a means
for people in selected communities within Eastern Nova Scotia to become more
involved in decision making within the province's emerging decentralized health
system. Using community health impact assessment (CHIA) as a population health
strategy, community members were able to identify factors that determine their
health and to develop tools to help them assess the health impact of programs and
policies within their communities. The participatory process used throughout the
PATH Project enabled a wide range of people to generate information for designing
a community health impact assessment tool (CHIAT) unique to their community. It
also helped participants to broaden their understanding of the many factors
determining health of their community and of the region.
PMID- 10686763
TI - Health indicator development in Alberta health authorities: searching for common
ground.
AB - The ability to measure population health trends and improvements can be enhanced
through collaborative efforts to describe existing knowledge and via shared
development opportunities. This paper highlights a project undertaken in Alberta
which has created an inventory of health status indicators in use in the
province, and provides a framework for strategic progress in the development and
use of a common set of indicators across the province. The work may provide a
model for other regional health authorities interested in comparing the health of
their populations across time and across health regions.
PMID- 10686764
TI - Applying a population health approach.
AB - While concepts that underlie good public health and population approaches to
health go back a long way, renewed recognition that health is dependent on more
than the ability to treat has given new impetus to a more comprehensive approach
to thinking about and planning for health and human services. This paper offers a
reflection on how we conceptualize population approaches to health. Recognizing
our current understanding of health determinants and dynamics, the paper explores
moving from "avoiding disease" to to "pursuing health." It then examines the
pragmatic balancing act of science, art, beliefs and politics, with attendant
traps. It concludes with a way of framing action on population health and
translating theory into practice.
PMID- 10686765
TI - Shared responsibility for population health: a personal reflection.
PMID- 10686766
TI - Advancing the population health agenda: uniting altruism and self-interest.
PMID- 10686767
TI - Future directions in population health.
AB - The long-term health of the population will be influenced by a number of major
forces in the next century. In this brief review, particular emphasis is placed
on environmental and economic forces. Major global environmental changes include
climate change and global warming, resource depletion, ecotoxicity and reduced
biodiversity. We do not yet know the impact on longevity of lifetime exposure to
a mix of persistent toxic chemicals in our environment, since it has only been
widespread in the past 40-50 years. The health impacts of global warming are only
just beginning to be understood and could be profound. But perhaps the most
profound threat to population health is economic growth, to the extent that it
undermines environmental and social sustainability. We need a new form of
capitalism, one that simultaneously increases environmental, social, economic and
human capital, if population health is to be maintained in the 21st century.
PMID- 10686768
TI - Population health in Canada: issues and challenges for policy, practice and
research.
AB - The population health movement has gained prominence in Canada and elsewhere with
policy makers, program planners and researchers taking note that health is
strongly influenced by factors that lie largely beyond the health-care system.
The development of population health in Canada was the focus of the National
Conference on Shared Responsibility for Health & Social Impact Assessments:
Advancing the Agenda held May 2-3 1999 in Vancouver, Canada. A longer version of
this paper was distributed to conference participants to provide some common
knowledge and vocabulary. It also introduced and discussed definitional,
normative, logistical, political, methodological, structural and resource
considerations with respect to furthering the population health agenda in Canada.
PMID- 10686769
TI - Endovascular treatment of aortic aneurysms of the abdominal aorta with covered
stents.
AB - Abdominal aortic aneurysms are common in the aging population; their surgical
treatment is well established and allows good results in specialized centers.
Endovascular exclusion of abdominal aortic aneurysms has been shown to be
feasible since 1991 and nowadays commercially available bifurcated endografts
allow safe exclusion in selected cases. In the last year 22 patients with an
aorto-iliac aneurysm received endovascular treatment at our Institution. We
included patients with favorable anatomic characteristics (i.e. neck > 15 mm
length, and < 28 mm diameter, iliac neck < 12 mm diameter, absence of > 90
degrees iliac or aortic angulation) and, in particular, those with increased
surgical risk for systemic pathology (12 patients), or hostile abdomen (9
patients). We employed Vanguard II (Boston Scientific) endovascular grafts
introduced through a surgically exposed common femoral artery; the contralateral
limb of bifurcated grafts was inserted percutaneously. The endograft was
successfully implanted in all cases, requiring additional iliac cuffs for
complete aneurysm exclusion in 3 cases. Periprocedural morbidity included one
case of thrombosis and one case of pseudoaneurysm of the punctured femoral
artery, which required surgical treatment. In one case surgical exposure of the
iliac artery was required in order to advance the device into the aorta. In one
patient who previously underwent hemicolectomy, postoperative colonic ischemia
was observed, and pharmacological treatment was required. Moreover we also
observed one case of groin infection that was treated successfully with local
wound care and systemic antibiotics, and one late contralateral limb thrombosis
that was successfully treated with loco-regional thrombolysis. The mean follow-up
was 6.1 months: one patient died because of congestive heart failure. No further
morbidity was recorded. A type-II endoleak was observed in one patient,
originating from the inferior mesenteric artery with no sac enlargement; this
patient is still under observation. In conclusion, with proper clinical
selection, commercially available endovascular devices allow safe exclusion of
abdominal aortic aneurysms. Long-term follow-up is needed to ascertain the
durability of the procedure.
PMID- 10686770
TI - Cardiac risk stratification of patients undergoing peripheral vascular surgery.
AB - Approximately 50% of patients with peripheral vascular disease have severe
coronary artery disease. Several ways of predicting the postoperative risk of
major cardiac events in peripheral vascular patients have been suggested. Among
preoperative tests, echocardiography is now receiving greater favor for risk
stratification.
PMID- 10686771
TI - Preinfarction angina and myocardial preconditioning.
AB - In the current era of pharmacologic and mechanical reperfusion therapy, several
studies have consistently shown that patients with myocardial infarction preceded
by angina have smaller infarcts and a better in-hospital outcome after
thrombolytic therapy than patients without preinfarction angina. At least three
mechanisms may explain these differences between infarctions that are preceded by
angina and those that are not: coronary collaterals, reperfusion rate, and
ischemic preconditioning. Collaterals alone do not seem to explain the beneficial
effects of preinfarction angina, although it is difficult to completely rule out
their role in the clinical setting. The possibility that preinfarction angina is
not protective per se, but rather is a predictor of a more rapid coronary
reperfusion is attractive; however, it should be addressed by further clinical
studies. Finally, it is likely that the beneficial effects of preinfarction
angina are related to ischemic preconditioning. Although a direct demonstration
of this hypothesis is still lacking, clinical features of preinfarction angina,
which is characterized by anginal attacks preceding acute myocardial infarction,
are very similar to those of ischemic preconditioning, in which brief ischemic
episodes precede a prolonged ischemic period. Indeed, the demonstration of
ischemic preconditioning in different clinical models of ischemia and reperfusion
and the identification of some of its mediators suggest that in patients at high
risk of myocardial infarction drugs known to block this endogenous form of
protection should be used with caution, while drugs known to elicit
preconditioning might have a relevant therapeutic role. However, the optimal
timing, administration, and dosage for preconditioning-mimetic drugs in the
appropriate clinical setting are still under debate and warrant further
investigation.
PMID- 10686772
TI - Emerging antithrombotic treatments for acute coronary syndromes.
AB - In the last few years the hypothesis of coronary thrombosis, frequently triggered
by plaque ulceration or fissuration, has gained wide acceptance as one of the key
events in the pathophysiology of acute coronary syndromes. Plaque ulceration may
activate both platelets and the coagulation cascade via exposure of a variety of
substances, such as von Willebrand factor and tissue factor. It has been
demonstrated that aspirin reduces mortality and improves the prognosis of
patients with such syndromes. More recently, newer drugs have been identified for
the treatment of acute coronary syndromes; in particular, platelet glycoprotein
IIb/IIIa inhibitors have been found to be more effective than aspirin in a
variety of clinical conditions, such as unstable angina, acute myocardial
infarction, and coronary angioplasty. Other drugs with different mechanisms of
action will be soon available for large scale clinical trials.
PMID- 10686773
TI - Rescue coronary angioplasty: a crotch for limping thrombolysis?
AB - After failed thrombolysis, rescue coronary angioplasty is performed with the aim
of restoring complete flow in the infarct-related artery. The clinical benefit of
this strategy has been debated in few clinical trials during the early '90s, and
high procedure-related risks, low success and early reocclusion rates seemed to
outweigh the benefit of mechanical recanalization. The RESCUE trial and, more
recently, data from the GUSTO angiographic substudy supported the hypothesis of a
better outcome among patients aggressively managed after failed thrombolysis.
Noninvasive identification of such patients must be accomplished monitoring
electrocardiogram and biochemical markers of myocardial necrosis. Further
improvements in the management of candidates to rescue coronary angioplasty can
be obtained with a more liberal use of intra-aortic balloon pump among subjects
admitted in cardiogenic shock; stents and platelet aggregation inhibitors could
reduce early reocclusion, but randomized data are needed to test this hypothesis.
PMID- 10686774
TI - Oxygen consumption.
AB - It gets more and more frequent to use oxygen consumption (VO2) to evaluate
exercise capacity and response to treatment in heart failure patients. The amount
of VO2 is due to ventilation, oxygen transport and muscle activity. No one of
these single steps can define by itself VO2, but all these physiological
functions are integrated each other. In this paper we examine the modifications
of cardiac output, arteriovenous oxygen content difference, and the temporal
behavior of their variations during exercise in heart failure. We specifically
describe changes in VO2 during simulated altitude; we also contemplate mechanisms
governing oxygen diffusion from capillary bed to mitochondria and critical
capillary PO2 concept.
PMID- 10686775
TI - Short-term effect of exercise on platelet factor 4 in normal subjects and in
patients with coronary artery disease.
AB - BACKGROUND: The aim of this study was to evaluate the plasma concentration of a
platelet-derived protein, platelet factor 4 (PF4), before and after exercise in
coronary artery disease. METHODS: We enrolled 60 patients with documented
ischemic heart disease. The subjects were divided into two groups: Group 1
patients with previous myocardial infarction (n = 20, 13 males, 7 females, mean
age 51.6 +/- 7.5 years, range 38-62 years); Group 2 patients with exercise
induced angina (n = 40, 22 males, 18 females, mean age 52.6 +/- 8.0 years, range
38-65 years). Patients with hypertension, hyperlipidemia and diabetes were
excluded. Patients with angina or ST segment depression during the stress test
were included in a subgroup (n = 33, 21 males, 12 females, mean age 50.3 +/- 6.3
years, range 40-65 years). Twenty healthy subjects without coronary risk factors
(13 males, 7 females, mean age 53.2 +/- 7.1 years, range 38-65 years) served as
controls. PF4 was measured in all patients at baseline and 5 min after a bicycle
exercise test. Plasma PF4 levels were measured performed by radioimmunoassay
(ng/ml, normal range 0-10). RESULTS: Patients with ischemic heart disease showed
a high basal concentration of PF4 compared with controls. PF4 levels at baseline
vs after stress test were 4.1 +/- 2.5 vs 5.3 +/- 2.6 ng/ml in healthy subjects;
33.4 +/- 15.8 vs 56.2 +/- 28.2 ng/ml (p < 0.001) in Group 1; 22.4 +/- 15.8 vs
44.6 +/- 28.4 ng/ml (p < 0.001) in Group 2; 29.9 +/- 15.5 vs 67.7 +/- 26.1 ng/ml
in the subgroup with angina or ST segment depression (p < 0.001), and 23.1 +/-
16.5 vs 26.0 +/- 18.1 ng/ml in those without angina or ST segment depression
(NS). CONCLUSIONS: These findings support the hypothesis that a significant
increase in PF4 levels after exercise is associated with clinically significant
coronary artery disease.
PMID- 10686776
TI - Platelet activation with exercise in coronary disease. Is it ischemia or
atherosclerosis?
PMID- 10686777
TI - Left ventricular metastasis from uterine leiomyosarcoma.
AB - Cardiac metastases are uncommon but seem to be increasing in incidence, possibly
in relation to prolonged survival of cancer patients. Leiomyosarcoma metastatic
to the heart is extremely rare. We report the case of a 57-year-old woman
previously treated for uterine leiomyosarcoma who presented with dyspnea,
electrocardiographic changes mimicking myocardial infarction, and normal enzymes.
A left intraventricular mass, suspected as cardiac metastasis, was revealed by
echocardiography. The patient died 1 week later. At autopsy the mass proved to be
histologically a metastasis of the uterine tumor.
PMID- 10686778
TI - [50 years among the pioneers of a new medical specialty; the development of
modern traumatology].
AB - On the basis of his half a century medical experiences the author analyses how
the traumatology became an independent branch of medicine.--L. Markusovszky's
scientific achievements in the domain of the field surgery, organization,
education and professional policy considerably influenced the development of the
traumatology. Derived from the surgery, the present-day traumatology's basis
feature is to provide a high-level professional education and a well organised
continuing medical attendance.--The achievements of the last fifty years are now
disclosed to the readers on the strength of the experiences of the author and his
contemporary collegues. He breaks the national events into 10 years periods which
are in fact representing the efforts and the results of the European shools.
Finally in the approach of the second millennium he is looking toward the future.
With the full knowledge of the nowadays difficulties he is trying to answer how
will advance all that has been founded in the last fifty years. Especially as in
the next few decades the harmonization European, an internationally similar high
quality medical attendance will be a considerable task.
PMID- 10686779
TI - [The role of alpha-interferon therapy in chronic myeloid leukemia].
AB - Alpha-interferons are widely accepted and used in chronic myeloid leukaemia. The
standard indication is the chronic phase, and it seems to be clear, that by
prolonging the chronic phase interferon therapy results in better overall
survival than busulphan or hydroxyurea (this comparison needs metaanalysis)
monotherapy. A review and recommendation is given considering the indications
(with a special attention to stemcell transplantation), dosage, contraindications
and monitoring interferon treatment.
PMID- 10686780
TI - [Ovulation induction therapy and malignant ovarian cancer].
AB - In the authors' institute 1097 patients received treatment for ovarian cancer
between the 1st of January, 1960 and the 31st of December, 1997. 92 of them had
malignant granulosa cell tumor. In this study the link between ovulation
induction therapy and ovarian cancer was analyzed with retrospective
questionnaire. 236 questionnaires were shared out among patients with malignant
ovarian tumor, who were treated between 1990 and 1997. 7 of 113 patients, who
gave correct answers to the questions (6.2%) received ovulation induction
therapy. Epithelial ovarian cancer developed in 2 of the cases during, and in 5
cases just 6-16 years after the clomiphene-citrate treatment. None of the 45
patients with granulosa cell tumors received induction therapy. The number of
patients admitted because of malignant ovarian tumor before and after the
induction therapy was also compared. There was no significant increase in the
occurrence of the malignancy. Since 1986 in the in vitro fertilization program of
the clinic nearly 1,500 patients were treated with effected ovulation induction
drugs causing superovulation. The authors don't know of any development of
malignant ovarian tumor, and 732 woman have confirmed this fact. The number of
patients deceased in consequence of ovarian cancer in different age groups, and
the distribution of the women population in every age group in Hungary, from the
year of 1979 was also analyzed. There was no significant increase found in the
number of deceased among the studied age groups, moreover a significant decrease
among them could be observed. The link between ovulation induction therapy and
ovarian cancer can neither be strengthen, nor deny by the result of the study,
however the close relationship which seemed to be logical can be queried. To give
an exact answer for the question a vast, long-term, prospective of retrospective
follow-up case-control study is needed.
PMID- 10686781
TI - [Use of two teflon stents in malignant non-hilar biliary atresia].
AB - Insertion of biliary stents in cases of malignant biliary obstruction is a widely
accepted method to resolve jaundice. The authors applied two 10 French biliary
teflon stents to prolong the drain patency in 32 patients with distal malignant
obstruction, thought to be inoperable at the time of intervention. Among the
followed, inoperable 23 cases 14 patients died for the time of evaluation. The
median survival was 150 days, the median drain patency was 99 days. Cholangitis
was the cause of death in three patients. Repeated endoscopic interventions were:
transient nasobiliary drainage without drain replacement in two patients and four
changes of stents in three patients. In the 13 patients, surviving and wearing
their drains at least for 100 days the patency of the double drains was 157 days.
These results obtained in the long-time survivors support the comparability of
the patency of double teflon stent to that of metalstents. In majority of cases
the two teflon drains remained patent until the deaths of patients.
PMID- 10686782
TI - [Beginning of the cholera epidemic in 1848].
PMID- 10686783
TI - [Elections in Hungary--Physicians and pharmacists in the independent government
1861-1862].
PMID- 10686784
TI - [Commemorative coins for researchers in geriatrics and caregivers for the aged].
PMID- 10686785
TI - [Management of Lyme disease].
PMID- 10686786
TI - [Allergen immunotherapy--therapeutic vaccines for allergy and asthma].
PMID- 10686787
TI - [50 years PPmP--what lies ahead?].
PMID- 10686788
TI - [Using integrative approaches in psychotherapy].
AB - Surveys on both sides of the Atlantic show that eclecticism and integrative
approaches in psychotherapy enjoy growing popularity. At the same time the idea
of integration still meets with major resistance in schools of psychotherapy and
training institutions, as well as in clinics. Therefore it not seems the right
time to inquire into the usefulness of eclectic and integrative approaches. After
a conceptual clarification this paper looks for criteria for the usefulness of
such approaches and for empirical work establishing it, as well as for the
conditions needed for such approaches to be useful. It is concluded that there
are several reasons for, and hints at the usefulness of integrative approaches,
but not yet many empirical validations. Recent empirical research, however,
clearly shows that for certain patients and certain disorders and problems
combined treatments are the treatments of choice, and that further research as
well as better training in differential diagnostics and in combined treatments
are not only of major interest to the patient and the therapists but are also
feasible.
PMID- 10686789
TI - [First all-Germany standardization of the brief form of the Gissen Complaints
Questionnaire GBB-24].
AB - At the end of 1994 a shortened version of the Giessen Subjective Complaints List
(GBB-24), was standardised using a sample of 2182 subjects aged 18 to 60 years,
representative of the population of re-unified Germany (720 from East Germany,
1462 from West-Germany). The item norms are given for the whole group, while the
scale norms are also subdivided according to gender, age (18-30, 31-40, 41-50 and
51-60 years) and place of residence (East/West). The dependence of physical
complaints on age and gender has diminished significantly since 1975, whereas the
factor structure and the internal consistency of the scales have changed only
slightly. The relative influence of further socio-demographic variables
(education, income, partnership status, town/country, unemployment) and attitudes
health on the scale scores of the GBB-24 are described. The results were also
correlated with data from Giessen-Test (GT) and a questionnaire on life
satisfaction (Fragebogen zur Lebenszufriedenheit FLZ), collected at the same
time. As expected, significant relationships were found between Scale 4
(Depression) of the Giessen-Test and all scales of the GBB-24, particularly Scale
1 "Exhaustion". A significant relationship with life satisfaction was also found,
i.e. absence of complaints corresponded with greater life satisfaction. As
anticipated, this relationship became most evident in the area of physical
health.
PMID- 10686790
TI - [Recent developments in systematic evaluation of the therapeutic process. Scales
for the assessment of adherence and competence].
AB - The assessment of therapists' behaviour an essential part of psychotherapy
research, especially for controlling the validity of studies. In the last decade,
particularly in English-speaking countries, research has been developed that
studied two constructs important in this context: adherence and competence.
Adherence refers to the extent to which therapists use the strategies recommended
in a therapy manual; competence refers to the quality of the use of these
strategies. This article is a review of research associated with adherence and
competence scales and its relevance. First of all, definitions and examples of
use are presented and discussed. Secondly, some of the most important scales that
have been developed in this context are described. Thirdly, aspects of
realisation are presented. Finally, the pros and cons of this type of research
are discussed. It is argued that despite some problems adherence and competence
scales are a significant contribution to the systematic assessment of therapist
behaviour.
PMID- 10686791
TI - [Psychotherapists should at least be able to count to 3--or?].
PMID- 10686792
TI - [Methodological openness as the basis of integrative psychotherapy].
PMID- 10686793
TI - [Image of the month. Percutaneous closure of an interauricular communications].
PMID- 10686794
TI - [Pharma-clinics. How I treat ... HIV infection. III. Non-nucleoside reverse
transcriptase inhibitors].
AB - Non nucleoside reverse transcriptase inhibitors (NNRTI) are a new arm in the
treatment of the HIV infection. They inhibit the replication by direct non
competitive binding to the enzyme, and do not require phosphorylation. The fast
emergence of resistance in monotherapy obliges to use them in a triple
association. The 103 mutation confers a cross-resistance. The most common adverse
event is rash. Association with nucleoside analogues is additive or even
synergistic. They are metabolized by the cytochrome P450. Within a combined
therapy, their efficiency is comparable to protease inhibitors, notably in
patients with low viral load.
PMID- 10686795
TI - [Clinical case of the month. Mental confusion due to the administration of
tramadol in a patient treated with MOAI].
AB - However currently less used, MAOI (monoamine-oxidase inhibitor) antidepressants
have specific indications like refractory or atypical depressions. The main
difficulties related to MAOI therapy consist in their potentially very dangerous
interactions with certain foods on the one side, many medications on the other
side. For example, we report the case of a patient treated for a resistant
depression by phenelzine (Nardelzine) who presented a severe delirium after the
administration of tramadol (Contramal, Dolzam). This case shows the importance of
particular attention before the association of any drug in a patient treated by
MAOI.
PMID- 10686796
TI - [Therapeutic non-compliance: a major problem in the prevention of cardiovascular
diseases].
AB - The prevention of cardiovascular diseases relies upon the correction of risk
factors and, more particularly, the optimal management of various metabolic
abnormalities such as obesity, dyslipidaemias, diabetes mellitus and arterial
hypertension. Such an approach first requires the adherence to life-style habits
(healthy diet, physical activity and no smoking) and, in case of failure, the use
of lipid-lowering drugs, antidiabetic agents and/or antihypertensive medications.
Sometimes, a monotherapy may be sufficient but, in most cases, a drug combination
is mandatory because of the need to reach tight therapeutic targets and of the
presence of a polypathology, especially within the frame of the metabolic
syndrome. Unfortunately, all surveys indicate that therapeutic compliance to non
pharmacological advice and even to drug prescriptions is far from being
excellent. Such a non-compliance limits the efficacy of the prevention strategies
and contributes to markedly increase the cost of metabolic diseases and
associated complications.
PMID- 10686797
TI - [Polyarteritis nodosa related to hepatitis b virus infection].
AB - A 66-year-old man was hospitalized for asthenia, weight loss, fever and chills. A
polyarteritis nodosa associated with hepatitis B virus infection in a replicative
phase was diagnosed. Etiology, physiopathology, and clinical characteristics of
hepatitis B virus-related polyarteritis nodosa will be reviewed, as well as the
effectiveness of therapy combining corticosteroids, interferon alpha and plasma
exchanges.
PMID- 10686798
TI - [Role of positron emission tomography is the evaluation of digestive tract
tumors].
AB - Imaging and endoscopic techniques have taken an increasing part in the management
of gastroenterological disorders. Among these techniques, FDG-PET imaging has
emerged as a powerful tool in the management of several cancer diseases,
including tumors of the digestive tract. In particular, the role of PET for
diagnosing and staging recurrent colorectal cancers, and for differentiating mass
forming pancreatitis from carcinoma is now well established. In this review, we
will briefly discuss the place of PET imaging in the work-up of the tumors of the
digestive tract.
PMID- 10686799
TI - [Do you have a good nose? Small lexicon of bromhidroses and other body odors].
AB - Body odours have a semiological significance in dermatology and in internal
medicine and pediatrics as well. Most of them are brought by the eccrine or
apocrine sweat. The term bromhidrosis refers to such conditions. Body odours
originate from metabolic disorders, ingestion of food, toxic elements and drugs,
and from contact with various xenobiotics. Specific bacterial infections and
contaminations also release volatile smelling compounds without the intervention
of sweat.
PMID- 10686800
TI - [Fibromuscular dysplasia].
AB - Fibromuscular dysplasia is a rare non-atherosclerotic, non-inflammatory arterial
disease. It concerns less than 1% of all occlusive artery lesions, but is more
common in young female patients, with a prevalence of 3 to 5% of the arterial
lesions in that age group. It mainly attains renal and carotid arteries. The
authors discuss the etiopathogeny, the prevalence and treatment of fibromuscular
dysplasia. Their own surgical experience with 21 renal and 10 carotid lesions of
fibromuscular is exposed.
PMID- 10686801
TI - [How I investigate ... dyskalemia].
AB - Potassium is the most important intracellular cation, playing a role in
neuromuscular excitability. Dyskalemia is common. The consequence of this ionic
perturbation could be serious related to its magnitude. Thus a quick etiological
approach and a medical intervention are needed to rapidly correct this
potentially lethal ionic disturbance and prevent its recurrence.
PMID- 10686802
TI - [Pharma-clinics. The drug of the month. Nevirapine. Viramune].
AB - Nevirapine is the first non nucleoside reverse transcriptase inhibitor registered
in Belgium and indicated in the treatment of HIV-1 infection. In association with
2 nucleoside analogues, its efficiency is similar to a tritherapy with protease
inhibitor, particularly in naive patients with low viral load. It has a good
tolerance profile and is easy to take. Studies in progress should permit to widen
its indications.
PMID- 10686803
TI - [Clinical study of the month. The ATLAS study].
AB - The Atlas Study was set up to compare the efficacy and safety of low doses and
high doses of ACE inhibition by lisinopril on the risk of death and
hospitalization in chronic heart failure. Three thousand one hundred sixty-four
patients with class II to IV heart failure and an ejection fraction below 30%
were randomly assigned to double blind treatment with either low doses (2.5-5
mg/daily, n = 1596) or high doses (32.5-35 mg/daily, n = 1568) of the ACE
inhibitor lisinopril for 39 to 58 months while background therapy for heart
failure was continued. Patients in the high dose group had a non significant 8%
lower risk of death (p = 0.128), but a significant 12% lower risk of death or
hospitalizations for any reason (p = 0.002) and 24% fewer hospitalizations for
heart failure (p = 0.002). Side-effects such as dizziness and renal insufficiency
were more frequently encountered in the high dose group, but there was no
difference between the two groups in terms of number of patients requiring
discontinuation of study medication. These findings indicate that patients with
heart failure should not, as too frequently is, be maintained on very low dose of
an ACE inhibitor unless this is the only dose that can be tolerated. The patients
are expected to benefit more if they receive higher doses close to those used in
the large clinical trials which have demonstrated a reduction by ACE inhibition
in morbidity and mortality in heart failure.
PMID- 10686804
TI - [What is your diagnosis? Extragenital endometriosis in the left rectus abdominis
muscle].
PMID- 10686805
TI - [Emerging and re-emerging infectious diseases--a challenge for public health].
AB - We have recently seen a worldwide explosion of infectious diseases: emerging
diseases like the HIV/AIDS pandemic, or old diseases like cholera, tuberculosis,
diphteria, plague, yellow fever, dengue, or malaria. These reemerging diseases
are on the surge because of multiple factors: environmental changes,
transformation of ecosystems, ongoing socioeconomic degradation and deterioration
of public health systems in many countries. The increasing bacterial resistance
to antibiotics or virologic resistance to antiviral drugs are becoming a serious
problem today. This global danger needs a global response. There must be a
cooperation between the different actors in the field of public health. The
general practitioner should look for good therapeutic compliance, control
vaccinations, and give his patients health education, including prevention of HIV
and other sexually transmitted diseases.
PMID- 10686806
TI - [Differential diagnosis and therapy of secondary hypertension (with special
reference to renal artery stenosis) in general practice].
AB - Secondary hypertension is present in 3-5% of patients suffering from high blood
pressure. Some of the causes of secondary hypertension can be cured and all of
them need specific treatment. This can only be provided when an accurate
diagnosis is sought. On the other hand, adequate knowledge of the different
etiologies and their respective clinical presentation avoids unnecessary and
expensive laboratory and imaging investigations. Renal artery stenosis is
increasingly being recognised as a relevant and frequent cause of secondary
hypertension and renal insufficiency, this previously underdiagnosed entity is
thus covered in some detail. Endocrine causes of secondary hypertension are
discussed, their diagnosis and treatment should be discussed with an
endocrinologist. Before diagnosing hypertension as being refractory to therapy,
adequate treatment and patient-compliance have to be enforced. Some frequently
overseen but important causes of hypertension in daily practice are also
discussed (drug-induced, loss of vessel wall elasticity in old age, etc.).
PMID- 10686807
TI - [Differential malignant lymphoproliferative syndrome (LPS) diagnosis with flow
cytometry: a study of 100 patients].
AB - The clinical utility of flow cytometry in diagnosis of chronic
lymphoproliferative disorders (LPD) is well established. Accurate diagnosis of
related but still distinct entities is relevant to therapeutic decisions. We
report on the immunophenotypic findings of 100 patients with a new diagnosis of
LPD established by two-color flow cytometry. A panel of > 15 monoclonal
antibodies was regularly applied. The characteristic immunophenotype of B-cell
chronic lymphocytic leukemia (CD5+, CD23+, FMC7-) was found in 74 patients
including one with Richter's transformation. Hairy cell leukemia (CD5-, CD11c+,
CD103+) was diagnosed in 6, and B-cell Non-Hodgkin lymphoma (B-NHL) in 13
patients, respectively. 6 of the B-NHLs belonged to the entity of splenic
lymphoma with villous lymphocytes (CD5-, CD23-, FMC7+) and 6 were identified as
mantle cell lymphomas (CD5+, CD23-, FMC7+). One B-NHL was typed as follicular
center cell lymphoma (CD5-, CD10+, FMC7+). Three B-cell LPDs without a
characteristic marker profile were histologically further classifiable. With a
total of 4 patients T-cell LPDs were much less frequent. Sezary syndrome (CD4+,
CD8-, CD56-) and T gamma lymphoproliferation (CD4-, CD8+, CD16-, CD56-, CD57+)
were diagnosed twice. In 17 patients with a characteristic marker profile (1
Richter's transformation, 5 hairy cell leukemias, 3 splenic lymphomas with
villous lymphocytes, 4 mantle cell lymphomas, 4 T-cell proliferations) a further
histological or molecular investigation confirmed the immunophenotypic diagnosis
in all cases. Clinical presentation with lymphadenopathies and B-symptoms was
mainly associated with the diagnosis of mantle cell lymphoma, whereas
splenomegaly and infection were suggestive of hairy cell leukemia. 94% of the B
CLL patients were diagnosed at an early clinical stage with still conserved
hematopoiesis, 32% of the LPDs were diagnosed following a routine hematogramm.
PMID- 10686808
TI - [Treatment concept in glaucoma].
PMID- 10686809
TI - [What is your diagnosis? Adenoid cystic prostatic carcinoma].
PMID- 10686810
TI - [Prevalence of diagnoses in ambulatory and hospitalized patients].
AB - Prevalence and distribution of different clinical presentations were analyzed in
6000 hospitalized and ambulatory patients. One medical University clinic and
three further hospital units, two university outpatient clinics and four
practitioners participated. 6000 main diagnoses and 2560 additional diagnoses had
been recorded. The mean age was 64 for the hospitalized patients, 50 years for
the outpatient clinic and 47 years at the doctors' office. Cardiovascular
diseases were most common. This group of diagnoses was twice as common in
hospitalized patients (40.9%) than in the ambulatory group: 19.5% (outpatient
clinic) and 15.2% (private practice). In contrast, psychiatric diagnoses were 5
times more frequent in the practice than in the hospital (11.6% vs. 2.4%) and
musculoskeletal diseases were even 7 times more common in the practice (13.3% vs.
1.9). 93% of the hospitalized patients had one of the 25 most prevalent
diagnoses. This percentage was substantially lower in patients of the outpatient
clinic (73%) and of private practice (64%). An additional diagnosis was posed for
every other patient in the hospital or at the outpatient clinic, in the
practitioners office only for every fourth patient. The analysis shows that
hospitalized patients often have a different set of diagnoses than ambulatory
ones. To guarantee a broad internistic training outpatient clinics are of great
importance. A part of internistic education, however, can also be obtained by
cooperation with practitioners.
PMID- 10686811
TI - [Primary HIV infection, how to recognize it?].
AB - The primary HIV infection is the period of time following HIV inoculation. Its
manifestations are diverse. We present here some clinical cases: a mononucleosis
like syndrome with fever, angina, lymphadenopathy and skin rash, a frequent
picture, with among other signs, flu-like symptoms, lymphocytic meningitis and
facial paresis. In presence of those nonspecific clinical pictures, it is
important for the primary health care physician to consider primary HIV
infection, detect a history of exposure and order HIV-tests including p24
antigenemia. On one side, an early treatment blocks replication and dissemination
of HIV in the body and brings an amelioration of prognosis. On the other side,
the patient is particularly infectious during this phase and should take
appropriate preventive measures.
PMID- 10686812
TI - [Sarcoidosis: acute versus chronic--2 case reports].
AB - Sarcoidosis manifests itself with different symptoms and can thereby follow an
acute or chronic course. We will discuss one case each. Case 1 involves a 41-year
old patient with Loefgren's syndrome, showing the typical trias of erythema
nodosum, bilateral hilar lymphadenopathy and acute polyarthritis. With systemic
steroid treatment the symptoms disappeared rapidly. In case 2 we present a 39
year-old-man with chronic sarcoidosis for several years with no vital threat. His
organ involvement includes chronic dacryocystitis. Systemic steroids relieved his
symptoms and the dacryo-rhinostomy could perhaps have been prevented had the
therapy been started earlier. Evaluating the diagnostic and therapeutic procedure
can be difficult because there are no standard guidelines. A vital threat demands
rapid diagnosis and effective therapy. The chronic illness requires a thorough
evaluation of the appropriate therapy. We discuss the criteria for diagnosis,
therapy and follow up.
PMID- 10686813
TI - [Phantom limb after amputation--overview and new knowledge].
AB - Almost all patients who have an extremity amputated will experience a phantom
limb. Amputations of other parts of the body can also cause phantom sensations.
One fourth of all women who undergo mastectomy relates phantom breast sensations.
Phantoms are common following rectum amputation and may be significant as
indicators of rectal tumor relapse. Visual phantoms can appear in patients who
undergo eye amputation. Phantom phenomena occur after tooth extraction,
ureterocystectomy, penectomy, plexus avulsion or spinal cord injury. The causes
underlying phantom sensations are unknown. Sensory deprivation in animals causes
reorganization of the cortical and subcortical maps: the areas representing the
deprived input shrink and the neighbouring areas expand. The mapping allocates
areas to represent the most used peripheral inputs. Every level of the nervous
system seems to exhibit plasticity. The primary site seems to be the cortex. The
cellular basis of plasticity is unclear. Significant sensory and motor
reorganization was found in humans suffering phantom pain. There was a strong
relationship between the amount of cortical reorganization and the intensity of
phantom pain. These findings may influence the rehabilitation of the amputee. It
was shown that pain and cortical reorganization can be reduced or even prevented
by the active use of prostheses.
PMID- 10686814
TI - [Postoperative nausea and vomiting: what can be done?].
PMID- 10686815
TI - [Erythema nodosum in grade I sarcoidosis].
PMID- 10686816
TI - [Biomechanical significance of the acetabular roof and its reaction to mechanical
injury].
AB - INTRODUCTION: The introduction of morphometry into the quantitative analysis of
the bone system and functional adaptation of acetabulum to mechanical damages and
injuries enabled a relatively simple and acceptable examination of morphological
acetabular changes in patients with damaged hip joints. Measurements of the depth
and form of acetabulum can be done by radiological methods, computerized
tomography and ultrasound (1-9). AIM OF STUDY: The aim of the study was to obtain
data on the behaviour of acetabular roof, the so-called "eyebrow", by
morphometric analyses during different mechanical injuries. METHOD: Clinical
studies of the effect of different loads on acetabular roof were carried out in
741 patients. Radiographic findings of 400 men and 341 women were analysed. The
control group was composed of 148 patients with normal hip joints. Average age of
the patients was 54.7 years and that of control subjects 52.0 years. Data
processing was done for all examined patients. RESULTS: On the basis of our
measurements the average size of female "eyebrow" ranged from 24.8 mm to 31.5 mm
with standard deviation of 0.93 and in men from 29.4 mm to 40.3 mm with standard
deviation of 1.54. The average size in the whole population was 32.1 mm with
standard deviation of 15.61. Statistical analyses revealed high correlation
coefficients between the age and "eyebrow" size in men (r = 0.124; p < 0.05); it
was statically in inverse proportion (Graph 1). However, in female patients the
correlation coefficient was statistically significant (r = 0.060; p > 0.05). The
examination of the size of collodiaphysial angle and length of "eyebrow" revealed
that "eyebrow" length was in inverse proportion to the size of collodiaphysial
angle (r = 0.113; p < 0.05). The average "eyebrow" length in relation to the size
of collodiaphysial angle ranged from 21.3 mm to 35.2 mm with standard deviation
of 1.60. There was no statistically significant correlation between the "eyebrow"
size and Wiberg's angle in male (r = 0.049; p > 0.05) and female (r = 0.005; p >
0.05) patients. The "eyebrow" length was proportionally dependent on the size of
the shortened extremity in all examined subjects. This dependence was
statistically significant both in female (r = 0.208; p < 0.05) and male (r =
0.193; p < 0.05) patients. The study revealed that fossa acetabuli was forward
and downward laterally directed. The size, form and cross-section of acetabulum
changed during different loads. Dimensions and morphological changes in
acetabulum showed some but unimportant changes in comparison to that in the
control group. These findings are graphically presented in Figure 5 and
numerically in Tables 1 and 2. DISCUSSION: The study of spatial orientation among
hip joints revealed that fossa acetabuli was forward and downward laterally
directed; this was in accordance with results other authors (1, 7, 9, 15, 18).
There was a statistically significant difference in relation to the "eyebrow"
size between patients and normal subjects (t = 3.88; p < 0.05). The average
difference of "eyebrow" size was 6.892 mm. A larger "eyebrow" was found in
patients with normally loaded hip. There was also a significant difference in
"eyebrow" size between patients and healthy female subjects (t = 4.605; p <
0.05). A larger "eyebrow" of 8.79 mm was found in female subjects with normally
loaded hip. On the basis of our study it can be concluded that the findings
related to changes in acetabular roof, the so-called "eyebrow", are important in
diagnosis, follow-up and therapy of pathogenetic processes of these disorders.
PMID- 10686817
TI - [Long-term patency of reversed and in situ femoro-popliteal bypasses].
AB - INTRODUCTION: The small choice of graft materials is one of the greatest problems
in femoro-popliteal (F-P) bypass reconstructions. Besides all biosynthetics(2-5)
and synthetics(6) graft materials, there is no right alternative for autologous
saphenous vein graft in F-P reconstructions. There are two main techniques for F
P reconstructions: "reversed" and "in situ". The aim of this study is the
comparison of the long-term patency between "reversed" and "in situ" F-P
bypasses. PATIENTS AND METHODS: In the study were included 191 patients with
"reversed" and 99 patients with "in situ" F-P bypass grafts operated on between
1988 and 1994. There were 153 (80.10%) male and 38 (19.90%) female patients in
the group with "reversed" bypass, and 78 (78.78%) male and 21 (21.22%) female
patients in the group with "in situ" bypass. The average age of all patients was
59.04 (27-80) years. Eighty five (44.5%) patients in the group with "reversed" F
P bypass had diabetes mellitus and 43 (43.43%) in the group with "in situ"
bypass. One hundred and fifty two (79.68%) patients in the group with "reversed"
bypass were cigarette smokers and as 80 (80.8%) in the group with "in situ"
bypass. In Table 1 the Fontain classification of occlusive diseases in operated
patients is presented. The early proximal reconstructions were performed in 49
patients with "reversed" and 16 patients with "in situ" bypasses (Table 2). The
associated proximal reconstructions were performed in 21 patients with "reversed"
and in 14 patients with "in situ" bypasses (Table 3). All patients were
controlled by physical and Doppler ultrasonographic examination immediately after
the operation, after 1, 3, 6 months, and then every year postoperativelly. In
cases with suspected graft occlusion or any other complication, control
angiographic examinations was also performed. The statistical analysis of the
results was done using "Life table" analysis. RESULTS: The patients were followed
up from 3 to 10 years. The results of "life-table" analysis are presented in
Tables 4-8 and Graph 1. The "in situ" technique showed statistically significant
better long-term patency compared to "reversed" technique, after 2 and 10 years
(p < 0.05). The immediate patency in cases with "reversed" bypass was 98.96%,
while limb salvage was 97.91%. In the same group long-term patency was 72.8% and
limb salvage 73.9%. In the group with "in situ" bypasses the immediate patency as
well as limb salvage were 96.97%. In the same group long-term patency was 73.8%
and limb salvage 77.2%. In Table 5 potential advantages of the "in situ" F-P
bypass technique are shown (16-21). However, there are controversial data on
clinical results of both bypasses. Some authors described better long-term
results of the "in situ" F-P bypass technique (28-30), while according to other
data there are no significant differences between these two bypass groups (31
33). Most authors emphasized the two advantages of "in situ" bypasses in F-P
reconstructions: a small diameter of the saphenous vein; in cases with pure run
off (34-36).
PMID- 10686818
TI - [Descriptive and epidemiologic characteristics of patients with malignant upper
urothelial tumors in the endemic area of Lazarevac].
AB - Although there is permanent increase in incidence of malignant upper urothelial
tumours [1, 2], these malignancies are rare neoplasms in relation to both all
malignant tumours and urotract tumours. Upper urothelial tumours, i.e. tumours of
the renal pelvis and ureter are more frequent in the regions affected by endemic
nephropathy [3-5]. The aim of this paper was to describe the main epidemiological
characteristics in patients with upper urothelial tumours (UUT) in endemic
nephropathic (EN) foci in Lazarevac. We analyzed 73 patients treated at the
Institute of Endemic Nephropathy, Lazarevac and the Institute of Urology and
Nephrology, Belgrade, from January 1, 1992 to December 31, 1994. The descriptive
epidemiological methods was used. The characteristics in patients with
histopathologically confirmed upper urothelial tumours were examined. The
diagnosis was made on the basis of the clinical picture, echo-sonographic and
radioscopic examinations, intravenous and infusion urography and retrograde
pielography. With genealogic analysis, a genealogical tree as far as the fourth
degree of kinship for each patient, was made both for urothelial tumours and
endemic nephropathy. The average age of the patients at the time of diagnosis was
64.2 years, and the majority of the patients (59%) was in the seventh decade of
life (Figure 1). Our results are in accordance with the results of other authors
who examined the patients with upper urothelial tumours in the regions with
endemic nephropathy and out of them [7, 8, 12, 14]. Females were more affected
than males (1.4:1). These results are in accordance with the results of other
authors who studied the endemic regions [7, 11, 13]. Foreign authors found that
males were more affected by upper urothelial tumours [9, 10]. In view of anatomic
localization of tumours (Table 2) our results are in accordance with results of
the studies carried out in endemic [11, 12, 15, 19] and non-endemic regions [8].
The majority of patients were rural population and lived in villages known as
endemic foci (89%) (Table 1). Agriculture was their main or additional
occupation. A large number of UUT patients (67%) had endemic nephropathy as well.
The other authors from our country found that farmers were most affected [17,
18]. In foreign studies, there are no data on the fact that farming is risk for
the appearance of upper urothelial tumours. The family agglomeration of UUT and
EN in UUT patients has been observed in all degrees of relation, especially in
the second and third generations (Table 3). The obtained results are comparable
with hypotheses on a possible mutual or the same aetiological factor for both
diseases, which is in accordance with the results of other authors who studied
the endemic regions [6, 7, 12, 13].
PMID- 10686819
TI - [Angioblastic lymphadenopathy--its course and prognosis].
AB - INTRODUCTION: In recent years important advances have been made in the
understanding of angioimmunoblastic lymphadenopathy since substantial controversy
has been related to the name, course, prognosis and therapy of the disease. It
was first recognized in the Kil Classification as a low risk T-cell lymphoma [5],
and omitted from the most widely used Working Formulation for clinical purposes.
According to the criteria of REAL (Revised European American Lymphoma),
classification angioimmunoblastic lymphadenopathy (AILD) is one of peripheral
postthymic T cell lymphomas that are an immunologically defined category of non
Hodgkin's lymphomas originating from the peripheral lymphatic tissues.
Morphologically, AILD is characterized by partially or completely obliterated
sinuses and frequent infiltration of the pericapsular tissue and substantial
proliferation of epithelioid, postcapillary venules. Cytologically, polymorphous
cellular infiltration with immunoblasts, transformed lymphoid cells, polyclonal
plasma cells, eosinophils and epithelioid cells are found. Clinically, rapid
occurrence of systemic symptoms in elderly individuals (sixth and seventh decades
of life) with generalized lymphadenopathy, hepatosplenomegaly and cutaneous
maculo-papulous or erythematous rash is noted. The patients are characterized
with hyperimmune condition in the form of Coombs' positive haemolytic anaemia,
polyclonal hypergamma-globulinaemia and liability to infections [8, 9]. In spite
of numerous suggestions, therapeutic consensus has not been achieved, and the
reported survival ranges from 1 to 30 months [10, 11]. Therefore, this
information suggests an aggressive form of the disease with the 60% mortality
rate. METHODS: At the Institute of Haematology of the Clinical Centre of Serbia
in Belgrade in the last five years, from 1993 through August 1998, nine patients
were diagnosed with AILD according to the results of pathohistological
examination of the extirpated peripheral lymph nodes and the correlation with
clinical picture and relevant laboratory findings. RESULTS: Clinical
characteristics of nine patients in whom AILD was diagnosed after lymph node
biopsy are given in Table 1. The group consisted of 6 men and 3 women, mean age
53. Eight patients were in advanced stage of the disease at the time of the
diagnosis (III and IC CS), while the patient in II CS stage had a large tumorous
mass (M+). All patients had initial systemic symptoms. Five of them developed
fever with chills. Three patients had evidence of extranodal infiltration of the
bone marrow. Infiltration of the liver was suspected in two patients according to
aberrant hepatogram values, although pathohistological verification was not
obtained. In one patient lung infiltration was histologically verified in
addition to bone marrow and liver infiltration. All patients had peripheral
lymphadenopathy, and most of them hepatosplenomegaly, as well. Three patients had
the so called bulky form of the disease since the diameter of the largest tumour
exceeded 10 cm. On admission, most were in poor overall condition, and only two
were apparently healthy. Knowing that AILD is basically an immunoregulatory
disease and that the described cases of association with systemic diseases of the
connective tissue and some drugs were implied in the triggering of AILD, Table 2
shows important information obtained form histories of these patients. Namely, 7
of 9 patients had cutaneous changes suggestive of erythematous or maculopapular
rash, while three had received corticosteroid therapy for months before AILD was
diagnosed since toxoallergic exanthema had been incorrectly suspected. Three
patients received gold sodium thiosulfate therapy for rheumatoid arthritis, while
four had history of allergy to drugs and pollen. Table 3 shows laboratory
results: anaemia was present in 8 of 9 patients, it was severe in three with
haemoglobin values of 67 g/L, 72 g/L and 50 g/L, respectively. Five patients had
haemolysis. A
PMID- 10686820
TI - [Organization of the program for prevention and control of nosocomial infections
in France].
AB - Nosocomial infections (NI) are infections acquired in hospitals. The aim of this
paper is to describe the organization of NI control program in France. The
organization of this program started in 1988 by the formation of the Infection
Control Committees in hospitals. Their role has been to organize the surveillance
of NI, to verify basic measures of hygiene, safety of invasive procedures,
disinfection and sterilization procedures, occupational safety, and to organize
the continued education of health staff members. Operational teams have also been
established in hospitals. At the national and regional levels, the National and
Regional Infection Control Committees were established in 1992 in order to define
the national policy for the treatment of actual infection problems in hospitals
and to organize the co-operation between hospitals. In addition, many research
projects concerning NI have been conducted and a number of international
scientific meetings regarding this subject have taken place in France. According
to the two surveys conducted at the national level, in 1990 and 1996, the
prevalence rate of NI was found to be 7.4 and 7.6%, respectively. The infection
control program could probably be integrated, in the future, into the Hospital
Risk Management Program.
PMID- 10686821
TI - [Epidemiologic and epizootiologic significance of ticks (Acari: Ixodidae,
Argasidae)].
PMID- 10686822
TI - [Experimental models for studies of chronic renal insufficiency].
PMID- 10686823
TI - [Chemotherapy of small-cell carcinoma of the bronchi].
PMID- 10686824
TI - [Electrophysiologic variants in late infantile neuronal-ceroid lipofuscinosis].
PMID- 10686825
TI - [Heterotopic liver tissue in the fundus of the gallbladder].
PMID- 10686826
TI - [Peliosis of the spleen].
PMID- 10686827
TI - [Anaphylactic reaction caused by histamine H2 receptor antagonists in a patient
with bronchial asthma].
PMID- 10686829
TI - Hepatitis C--global prevalence (update).
PMID- 10686828
TI - Lassa fever, case imported to Germany.
PMID- 10686830
TI - Vaccines and biologicals. Report of the Strategic Advisory Group of Experts
(SAGE), November 1999.
PMID- 10686831
TI - Influenza.
PMID- 10686832
TI - Long-term cephalometric changes in untreated adults compared to those treated
with orthognathic surgery.
AB - A surprisingly large amount of long-term remodeling of facial structures has been
noted in the period between 1 and 5 years post-orthognathic surgery. To evaluate
whether these changes are greater than in patients with similar morphology who
did not have surgery, long-term changes in hard tissue landmarks were examined in
33 untreated adults and compared to long-term changes in skeletal Class II
surgery patients who underwent maxillary impaction, mandibular advancement, or
both. Although the changes were small in both groups, mean changes were greater
in the surgical patients; the surgical patients also showed a higher percentage
of significant changes. Horizontal changes were in a forward direction in the
untreated group and a backward direction in the surgical groups. We conclude that
normal adult growth cannot account for the long-term changes observed following
jaw surgery. In some instances, postsurgical changes leading to relapse continue
much longer than would have been expected.
PMID- 10686833
TI - Psychologic implications of surgical-orthodontic treatment in patients with
anterior open bite.
AB - Two hundred eighty-two patients who received surgical-orthodontic treatment to
correct anterior open bite were retrospectively evaluated by interview and
questionnaires to determine the motivation and expectations before treatment,
experience during treatment, psychosocial impact, functional and esthetic
results, and satisfaction. All patients underwent a Le Fort I osteotomy, and 126
patients also received a bilateral sagittal split advancement osteotomy. The mean
follow-up was 6 years. The most important reasons for treatment, as cited by the
patients, were biting and chewing problems (28%), dissatisfaction with facial
appearance (26%), and symptoms of temporomandibular joint (TMJ) dysfunction
(21%). Patients with anterior open bite had a critical attitude toward facial
appearance; therefore, esthetic aspects should be taken seriously. The
expectations on chewing ability, phonetics, nasal passage, and facial appearance
were met by the treatment; however, expectations on TMJ function, interincisal
relationship, and biting ability were not completely fulfilled. There was a
subjective improvement of TMJ sounds in 27% and a worsening in 14% of the
patients. Dysesthesia of the infraorbital nerve was noticed in 4% of patients and
of the mental or inferior alveolar nerve in 23% of the patients. Chewing and
biting abilities improved in 53% and 73%, respectively. Facial appearance, self
confidence, and social interaction had improved. Patients had expected more
information before and psychologic support after treatment. Despite the relapse
of open bite in 20% of the patients, 75% were satisfied with the dental and 85%
with the facial appearance.
PMID- 10686834
TI - Psychosocial predictors of high-risk patients undergoing orthognathic surgery.
AB - The purpose of this analysis was to identify a set of predictor variables that
are prospectively related to postsurgical outcomes. Specifically, psychosocial
characteristics were sought to predict postsurgical outcomes. The 5 Revised
Symptom Checklist-90 (SCL-90-R) scales, the neuroticism score of the Eysenck
Personality Inventory (EPI), the psychosocial domain score from the Sickness
Impact Profile (SIP), and 4 scales from the Oral Health Status Questionnaire
(OHSQ) were used as the predictors. A total of 31 male and 86 female subjects
participated in this multicenter randomized trial, which compared rigid and wire
fixation. Data were collected prior to placement of orthodontic appliances, 1 to
2 weeks presurgery, and at 1 week, 8 weeks, 6 months, and 2 years after surgery.
Baseline oral health was used as an indicator of postsurgical oral health
functioning. A path analytic model of influences on presurgical oral health was
estimated (R2 = 0.43). The results suggest that presurgical screening of
demographic characteristics (age, sex, and ethnicity), oral health (the OHSQ),
quality of life issues (SIP), and personality features (SCL-90-R), accounts for
23% to 39% of the variance in postsurgical oral health outcomes. The path
analysis conducted suggests that a patient's age, ethnicity, gender, and elevated
scores on the EPI have indirect effects on postsurgical health. As determined by
a 2-stage least squares regression model, 3 variables--the patient's presurgical
oral health (per the OHSQ), pre- and postsurgical Global Severity Index (GSI)
score from the SCL-90-R, and the psychosocial scale score from the SIP--were
found to have a statistically significant impact on postsurgical outcomes.
Additionally, the GSI, SIP, and OHSQ are reliable measures in predicting oral
health outcomes.
PMID- 10686835
TI - Computer-animated comparison of self-perception with actual profiles of
orthodontic and nonorthodontic subjects.
AB - To determine if motivation for adult orthodontic treatment is influenced by self
perception, a computer morphing program was developed to animate discrete
digitized photographs of facial profiles. It was hypothesized that orthodontic
patients are less tolerant of variations in their profiles than nonorthodontic
patients. Sixteen orthodontic and 14 nonorthodontic adult patients were presented
with animated distortions of 5 features of the lower third of their own profiles.
They were asked to identify the zone of acceptability in the changing profile and
to indicate the single most pleasing distortion and their perceived and preferred
profiles, for comparison with their actual profile. Although orthodontic subjects
did not differ from nonorthodontic subjects in the zone of acceptability of their
own profiles, they were less tolerant (smaller zone of acceptability) of
variation in features of a standard control face. Orthodontic subjects, however,
had a larger disparity between the most pleasing and at least one feature of
their actual profile than did the nonorthodontic subjects. Orthodontic and
nonorthodontic subjects were equally accurate in their ability to identify their
own profile features. This unique method of measuring self-perception offers the
clinician the advantage of providing a dynamic range rather than a single point
of acceptable change to the patient. Moreover, this interactive computer program
will enable patients to actively participate in treatment planning decisions by
communicating preferences for variations in facial profile distortions.
PMID- 10686836
TI - Patients' evaluation of the final result of sagittal split osteotomy: is it
influenced by impaired sensitivity of the lower lip and chin?
AB - The purpose of this article was to evaluate whether neurosensory disturbances
such as impaired sensitivity of the lower lip and chin influence patients' final
evaluation of the treatment result. Information about the patients' degree of
satisfaction and about lip and chin sensitivity were obtained from final follow
up documents of 215 patients. All patients had undergone sagittal split ramus
osteotomy for mandibular advancement. In patients with normal sensitivity on both
sides of the lower lip and chin, the degree of satisfaction was equally
distributed at a very high level through all age groups. Among those with some
degree of numbness on either or both sides of the lower lip and chin, patients in
the younger quarter and middle half of the group were as satisfied as those with
normal sensitivity, while those in the oldest quarter with impaired sensitivity
demonstrated a lower degree of satisfaction than the rest of the patients.
Although the difference was not statistically significant, the finding strongly
indicates that older patients seem to suffer more from neurosensory disturbances
than do younger patients with similar conditions.
PMID- 10686837
TI - Three-dimensional computer-assisted simulation combining facial skeleton with
facial morphology for orthognathic surgery.
AB - The purpose of this study was to use a 3-dimensional (3D) computer-aided design
(CAD) simulation system to plan surgical procedures and predict postoperative
changes in orthognathic surgery patients. A computer-generated imaging model was
developed by combining a 3D reconstructed cephalometric skeletal image and a
laser-scanned facial surface image. Moreover, postoperative data were studied and
linked to the simulator model for programming and executing simulated surgical
procedures. Interactive editing capabilities allow surgeons to operate CAD
surgical simulation, and predicted results can be presented graphically and
numerically. The results indicate that the integration of 3D images and CAD
techniques have a potential for simulating surgery and providing graphic
information to patients in obtaining an informed consent.
PMID- 10686838
TI - Duration of orthodontic treatment involving orthognathic surgery.
AB - The purpose of this study was to analyze factors influencing the duration of
treatment in a sample of patients treated by a combined orthodontic/orthognathic
surgery approach. Presurgical and postsurgical treatment times were assessed for
315 patients processed through an orthognathic team over a 7-year period. The
median total treatment duration for all patients was 21.9 months, the median
presurgical duration was 15.4 months, and the median postsurgical duration was
5.9 months. Treatment involving extractions resulted in significantly increased
presurgical and total treatment times. Treatments performed in the university
clinic showed reduced presurgical duration and increased postsurgical duration
compared to treatments carried out by specialists outside the university.
Presurgical, postsurgical, and total treatment times were significantly reduced
when the orthodontist had treated 10 or more patients during the period. An
earlier regimen of orthodontic treatment did not appear to have a significant
effect on treatment duration.
PMID- 10686839
TI - Dental arch size in healthy human permanent dentitions: ethnic differences as
assessed by discriminant analysis.
AB - Race and ethnicity variably influence the form of the human craniofacial complex.
In the present study, the effects of ethnicity and sex on the global size of
normal adult dental arches were analyzed. The dental arches of 47 northern
Chilean mestizos (25 men, 22 women) and 95 northern Italian Caucasians (50 men,
45 women) were cast in stone. All subjects had a complete dentition in both
arches. In all models the coordinates of dental cusp tips were digitized using an
image analyzer. The center of gravity of each tooth was computed and arches were
interpolated using a polynomial model (y = ax + bx2 + cx3 + dx4). In all arches,
the intercanine, intermolar, and mid-intercanine to mid-intermolar distances were
computed from the dental centers of gravity. These arch distances were entered in
a linear discriminant function analysis. The polynomial model accurately
interpolated data points in all instances, and most of the dental arch form was
determined by the first and second degree coefficients. On average, Italian
Caucasian arches were smaller than Chilean mestizo arches. Male mean distances
were larger than female distances regardless of ethnic group or arch. The linear
discriminant analysis performed between male and female arches within ethnic
groups was significant only for both Italian Caucasian arches, but the percentage
errors for the classification of a new individual were very high (about 30%).
Conversely, Italian Caucasian arches could always be discriminated from Chilean
mestizo arches of the same sex with a much smaller error.
PMID- 10686840
TI - An unusual treatment with sagittal split osteotomy: report of a case involving an
odontoma.
AB - Sagittal split osteotomy is one of the most commonly performed surgical
techniques in the world and has been modified by many authors. The efficacy of
this operation has been studied by many groups. When performing this surgery,
there should be adequate contact of wide, cancellous bone surfaces, which
guarantees excellent and rapid bony union in the desired position. In the present
article, treatment of mandibular prognathism with open bite by sagittal split
osteotomy with an odontoma in the third molar area is presented.
PMID- 10686841
TI - Geometric considerations when planning an asymmetric genioplasty.
AB - The sliding osteotomy of the inferior border of the mandible, otherwise known as
genioplasty, has often been described in the world literature with regard to
diagnosis and treatment planning. However, the treatment of the asymmetric chin
has received little attention. Moreover, diagnosis and treatment planning of
asymmetric chins with concomitant orthognathic surgery is completely lacking from
the literature. The complexity of surgically correcting asymmetric chins,
compounded with complex, bimaxillary orthognathic surgery, is an extremely
challenging task. This article looks at geometric considerations when planning
the surgical correction of an asymmetric chin following a protocol of data
collection, model surgery, diagnosis, and treatment planning. Clinical experience
in the form of a case presentation will demonstrate the millimetric precision
that can be achieved when planning corrective genioplasty in an asymmetric
patient undergoing concomitant orthognathic surgery.
PMID- 10686842
TI - Vertical chin augmentation with interpositional porous polyethylene implants: a
histologic study in monkeys.
AB - The objective of this paper was to evaluate histologically the tissue reaction in
the chin after a vertical augmentation using interpositional porous polyethylene
(PPE) implants in monkeys. Six monkeys (Cebus apella) underwent an anterior
horizontal mandibular osteotomy with implantation of an interpositional PPE
implant to increase the vertical height. The animals were sacrificed 5 months
postoperatively. Histologic preparations were stained with hematoxylin and eosin.
The perimeter of the interface between the implant and the bone, the implant and
the trabecular space, and the implant and the fibrous capsule were quantified
using the NIH Image Analysis System (Image 1.60/PPC). In addition, the Tukey test
was done. The study demonstrated that bone growth takes place within the pores of
the implant; a fibrous capsule exists in some animals, where the implant has
contact with the periosteum and mentalis muscle with few chronic inflammatory
cells; and the 3 different tissues responded in statistically different manners.
Perimeter analysis revealed 68.9% implant-bone contact, 22.9% implant-fibrous
tissue contact, and 8.2% implant-trabecular space contact.
PMID- 10686843
TI - Demineralized intramembranous bone matrix augments the healing of endochondral
bone graft.
AB - The aim of this study was to examine the osteogenic potential of demineralized
bone matrix prepared from intramembranous bone (DBMIM) and to examine its effects
on the healing of endochondral autogenous bone grafts. Twenty-four defects in 24
New Zealand white rabbits were used as experimental groups. Twelve defects were
grafted with endochondral bone, and the other 12 defects were grafted with
endochondral bone with DBMIM (EC-DBMIM). One rabbit from each group was
sacrificed on days 1, 2, 3, 4, 5, 6, and 7 postgrafting, and the remaining 5
rabbits from each group were sacrificed on day 14 postgrafting. Another 8 defects
in 4 rabbits were used as control groups: 4 defects were left empty (passive
control), and 4 defects were grafted with rabbit skin collagen (positive
control). They were all sacrificed at 14 days after grafting. Serial sections
were made across the whole defect. Quantitative analysis was performed on 100
sections of the 14-day experimental groups by image analysis. Four hundred
fourteen percent more new bone was formed in defects grafted with composite EC
DBMIM than in those grafted with endochondral bone alone (P < 0.0001). No bone
was formed in either passive or positive controls. Histologic examination of the
bone grafts revealed intermediate-stage cartilage, and immunohistochemical
examination revealed earlier vascularization in the composite EC-DBMIM groups. In
conclusion, DBMIM has extremely high osteoinductive properties and greatly
enhances the integration of endochondral bone with defects of intramembranous
bone in origin.
PMID- 10686844
TI - Soft tissue changes associated with incisor decompensation prior to orthognathic
surgery.
AB - A retrospective cephalometric study employing angular and linear measurements was
undertaken to examine soft tissue changes associated with incisor decompensation
prior to orthognathic surgery. Subjects were divided into 3 groups based on the
presenting malocclusion, and radiographs for each subject were traced and
subsequently digitized. The results showed that incisor decompensation was
achieved more markedly in Class II division 2 and Class III patients. In Class II
division 1 subjects, changes in the mandibular incisor inclination were contrary
to what was anticipated. The soft tissue change/dental change ratio following
incisor decompensation showed that the soft tissues were least affected in the
Class II division 2 group. This may be due to the increased tone of the soft
tissues in this group, which resisted the effects of the incisor change.
Alternatively, it may indicate that the soft tissue "drape" is not in close
approximation to the dentition and therefore dental changes are not transmitted
to the soft tissues.
PMID- 10686845
TI - Stability of Le Fort I osteotomy in maxillary advancement: review of the
literature.
AB - Stability of the skeletal segments repositioned during orthognathic surgery is
still a concern in maxillofacial surgery. In an attempt to establish a consensus
about one of the most frequently performed repositioning surgeries, the
literature from 1985 to 1999 concerning stability of Le Fort I osteotomy in
maxillary advancement was reviewed. There have been many problems in interpreting
the results of the analysis because of differences in the design of the studies
and the multifactorial nature of the disorder. For this reason each problem that
emerged in the literature is analyzed and discussed.
PMID- 10686846
TI - Obstructive sleep apnea: a principal component analysis.
AB - A principal component analysis was performed on the cephalometric variables of
100 male obstructive sleep apnea (OSA) patients. Thirty cephalometric variables
of cervicocraniofacial skeletal morphology were reduced to 8 principal components
(PCs), which described 83.2% of the total variance. Sixteen cephalometric
variables of hyoid bone position and head posture were reduced to 4 PCs, which
described 85.5% of the total variance. Twenty cephalometric variables of upper
airway soft tissue were reduced to 7 PCs, which described 83.7% of the total
variance. These PCs described the actual characteristics of the OSA patients
examined. For further analysis of PCs, stepwise multiple regression analysis was
chosen. Two dependent variables of interest are the minimal distance of posterior
pharyngeal airway space (PASmin) and the Apnea-Hypopnea Index (AHI). Seven PCs
accounted for 79.4% of the variance of PASmin and 3 PCs accounted for 37.6% of
the variance of AHI. Both principal component analysis and multiple regression
analysis provide multivariate data analysis that is very useful in sorting out
and clarifying the complexity of the interrelated cervicocraniofacial skeletal
morphology and upper airway soft tissue in OSA patients.
PMID- 10686847
TI - Morphometry of the mandible in prepubertal craniofacial microsomia patients
following an inverted L osteotomy.
AB - The aim of this study was to undertake finite element modeling of craniofacial
microsomia (CFM) patients who exhibited a unilateral mandibular deformity that
was surgically corrected by an inverted L osteotomy and autogenous bone graft.
Preoperative, 1-year, and 3-year postoperative anteroposterior cephalographs of
14 consecutive children (mean age, about 9 years) with CFM were employed. All
cephalographs were scanned, and 8 homologous mandibular landmarks were digitized
in triplicate (digitization error < 1%; P > 0.05). Average mandibular geometries,
scaled to an equivalent size, were generated using Procrustes superimposition and
subjected to analysis of variance. Results showed that while the mean pre- and
early postoperative mandibular configurations marginally failed to differ
statistically, finite element modeling of the affected mandibular ramus showed a
positive allometry (a lengthening by about 10% to 12%) and marked anisotropy,
presumably reflecting the surgical procedure carried out in that region. For the
preoperative and late postoperative means, the configurations were statistically
different (P < 0.002), showing a lengthening of the ramus (about 14%) while the
unoperated side had a high degree of isotropy. The early and late postoperative
configurations were also statistically different (P < 0.002). The operated ramus
showed an increase in length (about 15%), but the corpus showed a decrease in
size (about 10%) and marked anisotropy that reflected remodeling associated with
the surgical procedure. Although mandibular morphology is improved in CFM
patients who are surgically treated by an inverted L osteotomy, some relapse is
evident due to deficient growth, localized in the mandibular ramus and body of
the affected side.
PMID- 10686848
TI - Use of articulators in the United Kingdom by consultant orthodontists in planning
orthognathic surgery.
AB - This questionnaire survey aimed to investigate articulator use in orthognathic
surgical planning by consultant specialists in the United Kingdom (UK). A total
of 205 questionnaires was sent to all consultant orthodontists in the UK. One
hundred thirty questionnaires were completed, representing a 63.4% response rate.
Consultants had been in their post for a median of 10.5 years (range 0 to 30
years) with a mean of 11.3 (SD 8.4) surgical cases per year. When asked which
cases had been planned on a semiadjustable articulator, two thirds of consultants
(67.7%) planned maxillary single-jaw procedures, 45.4% planned mandibular single
jaw procedures, and 77.7% planned bimaxillary procedures. While 98.5% of
consultants reported access to at least one type of articulator, 14.6% of
maxillary single-jaw and 5.4% of bimaxillary surgery was not planned on any
articulator. Twice as many consultants who had been in their post fewer than 11
years had been trained on a semiadjustable articulator, compared to those who had
more than 11 years of experience. Semiadjustable articulators were the most
popular for planning orthognathic surgery. Consultants with less than 11 years of
experience completed more surgical cases each year and were more likely to have
been trained on a semiadjustable articulator than consultants with more than 11
years of experience. However, no link exists between the age of the consultant
and the type of articulator selected for planning; this suggests that more mature
consultants have received further training on contemporary articulator systems
since receiving their accreditation.
PMID- 10686849
TI - Condylar resorption 2 years following active orthodontic treatment: a case
report.
AB - We recently treated a patient with degenerative disease of the temporomandibular
joint. A healthy, 12-year-old female with bilateral high maxillary canines
presented for orthodontic treatment. Two years after active orthodontic
treatment, at age 17, symptoms in her temporomandibular joint manifested and
progressed. By the time she revisited our hospital at age 21, the patient had
developed an anterior open bite with a long, slender facial appearance.
Cephalometric analysis showed shortening of the ramus and backward and downward
rotation of the mandible. Imaging studies revealed severe deformity and
resorption of the bilateral condyles. Her occlusal and morphologic changes seemed
to be caused by degenerative disease of the temporomandibular joint.
PMID- 10686850
TI - Dental applications of amorphous calcium phosphates.
AB - Certain commercial materials and equipment are identified in this paper to
specify the experimental procedure. In no instance does such identification imply
recognition or endorsement by the National Institute of Standards and Technology
or the ADA Health Foundation, or that the material or equipment identified is
necessarily the best available for the purpose.
PMID- 10686851
TI - The origins of Enamelon remineralizing fluoride toothpaste.
PMID- 10686852
TI - Laboratory enamel solubility reduction and fluoride uptake from enamelon
dentifrice.
AB - The presence of calcium-releasing ingredients in toothpastes containing sodium
fluoride is usually avoided to prevent loss of active fluoride due to the
formation of the insoluble calcium salt. The purpose of this study was to
determine the bio-availability of fluoride from Enamelon Toothpaste (E), which
simultaneously supplies fluoride, calcium and phosphate salts from a dual
dispensing package. Fluoride uptake into artificially lesioned enamel cores due
to the use of the test dentifrice (E) diluted 1:3 in whole human saliva was
compared to that from a clinically proven effective sodium fluoride/silica USP
reference toothpaste (C) and a non-fluoride control (E-w/o F). Enamel solubility
reduction due to the use of E, C and E-w/o F was measured by determining the
quantity of phosphate released to lactic acid buffer before and after treatment
of the crowns of molars with 1:3 slurries of the dentifrices in water. Fluoride
uptakes and enamel solubility reductions were 5031 +/- 158 ppm and 21.6 +/- 2.2%
for E, 1915 +/- 39 ppm and 13.6 +/- 2.0% for C, and -3 +/- 2 ppm and 0.8 +/- 1.7%
for E-w/o F. The fluoride uptake and enamel solubility reductions from E were
significantly greater than from C (p < 0.001, Fisher LSD), and both fluoride
containing dentifrices significantly outperformed E-w/o F (p < 0.001). The
laboratory results indicate that the calcium and phosphate salts delivered by the
remineralizing Enamelon dentifrice increase the bioavailability of fluoride to
substantially exceed that of the clinically proven standard dentifrice.
PMID- 10686853
TI - Remineralization by fluoride enhanced with calcium and phosphate ingredients.
AB - The effectiveness of fluoride ions provided by toothpastes and mouthrinses in
promoting remineralization can be limited by the low concentrations of calcium
and phosphate ions in saliva. The purpose of this study was to determine whether
improved remineralization can be obtained from toothpastes or mouthrinses that
simultaneously deliver fluoride, calcium, and phosphate ions from dual-dispensing
systems. Enamel specimens with artificial lesions between 60 and 90 microns deep
were cycled 15 times through demineralization for 30 minutes, treated for 5
minutes with an experimental or control fluoride toothpaste or mouthrinse, and
remineralized for 60 minutes. In the toothpaste study, surface hardness increased
by 11.5 +/- 9.2 and 2.7 +/- 3.6 Vickers hardness units, and enamel fluoride
content was 5984 +/- 521 ppm and 3971 +/- 531 ppm for the experimental and
control fluoride toothpastes, respectively. Remineralization was confirmed by x
ray microradiography. In the mouthrinse study, surface hardness increased by 8.8
+/- 7.7 and 2.2 +/- 3.7 Vickers hardness units, and enamel fluoride content was
6111 +/- 1078 ppm and 3160 +/- 364 ppm for the experimental and control fluoride
mouthrinses, respectively. Use of a non-fluoride control mouthrinse led to a
decrease in surface hardness of 3.7 +/- 5.2 Vickers hardness units despite a
fluoride content of 402 ppm. The results demonstrate that calcium and phosphate
supplementation in a toothpaste or mouthrinse can improve remineralization and
increase fluoride uptake.
PMID- 10686854
TI - Strengthening of tooth enamel by a remineralizing toothpaste after exposure to an
acidic soft drink.
AB - The effect of remineralizing and conventional toothpaste treatments on the
hardness of intact and acid soft drink-etched enamel were assessed in a
laboratory study. The remineralizing toothpaste (Enamelon Toothpaste) used in the
study contains NaF, and simultaneously provides dissolved calcium, phosphate and
fluoride ions. The conventional toothpaste contains NaF in a silica base. Sound
extracted maxillary human incisors, mounted in epoxy resin with the facial
incisal two-thirds exposed, were polished with 0.3 mu alumina. Groups of ten
teeth were exposed to either twenty 5-minute treatments with an acid soft drink
(pH 2.4), remineralizing or conventional fluoride toothpaste, or to twenty
alternating cycles of a 5-minute protective treatment with either the
remineralizing or conventional toothpastes, followed by 5-minute exposures to the
acid soft drink, or to 20 five-minute exposures to the acid soft drink followed
by 20 five-minute restorative treatments with the remineralizing or conventional
toothpastes. Knoop Hardness measurements were made before and after treatment
using a 500 g load and 15-second dwell time. Acid soft drink exposure produced a
15.4% drop in hardness compared with 4.9% and 1.6% hardness increases due to
treatments of intact enamel with the remineralizing and conventional toothpastes,
respectively. Protective treatments using the remineralizing and conventional
toothpastes significantly reduced the drop in hardness due to acid soft drink
exposure to 3.3% and 6.2%, respectively. Restorative treatments by the
remineralizing and conventional toothpastes significantly increased the hardness
of the acid soft drink-weakened enamel by 12.1% and 7.3%, respectively. Both
toothpastes were effective in inhibiting damage due to acid soft drink exposure,
but the remineralizing toothpaste was more effective in hardening intact and
decalcified enamel than the conventional toothpaste (p < 0.05).
PMID- 10686855
TI - The in vitro demineralization potential of a sodium fluoride, calcium and
phosphate ion-containing dentifrice under various experimental conditions.
AB - While fluoride has had a dramatic effect in reducing the rate of caries, it has
failed to provide complete protection against caries development, and tooth decay
is still widely prevalent. The objective of this study was to determine the
demineralization prevention potential of a remineralizing dentifrice with
fluoride (Enamelon), and an assured supply of calcium and phosphate ions on
bovine enamel in a cyclic remin/demin regimen using various experimental
conditions. A conventional fluoride toothpaste, Crest, and a placebo dentifrice
were used as controls. One-hundred and forty-four ground and polished 4 mm bovine
enamel cores were prepared and assigned to various test treatments using six
specimens per treatment group. They were subjected to six cyclic treatments
consisting of one-minute exposures at room temperature to the test product
diluted 1:2 in water, remineralization for a specified time at 37 degrees C, and
demineralization for a specified time at 37 degrees C. The enamel specimens were
tested for micro-hardness initially, and after the first, third and sixth
treatment, remineralization and demineralization cycles using a Buehler Micro
hardness Tester with a 200 g load. Differences in micro-hardness between the test
groups were analyzed for significance by performing multiple pair-wise
comparisons using Bonferroni significance levels at the 95% confidence level. The
results of this study showed that Enamelon Toothpaste was generally more
effective in preventing demineralization of enamel than the fluoride dentifrice
at 0.5 and 1.5 hours, and the non-fluoride control dentifrice at all time
measurements. Prevention of enamel demineralization by the dentifrices was
affected by changes in demineralization time and pH, but not by changes in
remineralization time.
PMID- 10686856
TI - Cariostatic effect of a two-part fluoride dentifrice in rats.
AB - This study compared the cariostatic effect of a two-part, fluoride-calcium
phosphate-containing prototype dentifrice (containing 1100 ppm F) to a
conventional, clinically proven effective "gold standard" (1100 ppm F, USP
Standard) and an Enamelon placebo dentifrice (0 ppm F) using a rat model. Three
groups of 18 Crl:CDR(SD)BR rats were inoculated with S. sobrinus 27352 and fed
MIT-200 for 35 days in a programmed feeder. Double-deionized water (DDW) was
given ad libitum. The rats were treated twice daily with one two-part dentifrice.
Just prior to treatment, each of the two parts of dentifrice were mixed 1:1 and
applied undiluted. The rats were euthanized and their mandibular molars scored
for caries using the Keyes quantification method. Shrestha SNP caries scores were
then calculated. Non-parametric comparisons were done among treatments at the
0.05 level of significance using analyses based on ranks. The mean Shrestha SNP
Caries Scores +/- standard deviations for the prototype dentifrice, USP standard
and Enamelon placebo were 84.9 +/- 62.8, 101.3 +/- 66.3, and 181.2 +/- 100.1,
respectively. Scores for the 1100 ppm F prototype treatment were significantly
lower than the USP Standard and the Enamelon placebo. These results indicate that
the new prototype dentifrice, containing fluoride-calcium-phosphate, increased
the anti-caries efficacy in a rat model when compared with a fluoride-containing
USP Standard dentifrice.
PMID- 10686857
TI - Caries inhibition in rats by a remineralizing toothpaste.
AB - We tested the anti-caries properties of a prototype remineralizing toothpaste
containing sodium fluoride, soluble phosphate and soluble calcium, similar but
not identical to Enamelon Toothpaste in specific pathogen-free Osborne-Mendel
rats. A fluoride-free placebo and sodium fluoride-containing Crest Regular were
used as negative and positive control toothpastes, respectively. Sixty weanling
rats were randomly distributed into groups of 20, all were inoculated with S.
mutans 10449S, ate diet 2000, and drank demineralized water. Each toothpaste,
contained in coded tubes, was applied to the rats' teeth, once for one
minute/day, five days/week. There was no difference in bacterial recoveries from
tooth swabs among the groups at either the 22- or 37-day post-inoculation
recovery date. After rat sacrifice and defleshing, heads were randomly coded and
scored blindly for carious lesions according to Keyes/Larson methods. Only after
scoring was completed were the random codes broken and the treatment groups
identified. Both the Enamelon-like product and Crest Regular treatments resulted
in lower total enamel caries scores than the placebo (p < 0.001). The sum of
smooth surface scores was also lower for the fluoride-containing toothpastes than
for the placebo (p < 0.001). However, the Enamelon-like product had greater
caries inhibitory properties than Crest Regular on sulcal and approximal tooth
surface categories (p = 0.004 and p = 0.045, respectively). Therefore, the
Enamelon-like product had superior caries inhibiting properties compared to Crest
Regular at these tooth areas.
PMID- 10686858
TI - Model for assessment of carious lesion remineralization, and remineralization by
a novel toothpaste.
AB - This study is of a novel toothpaste which induced remineralization of carious
lesions in specific pathogen-free Osborne-Mendel rats. Randomly distributed
weanlings in 7 groups (n = 10) each were initially induced to develop carious
lesions as a result of a severe dietary and bacteriological challenge. Thus, all
were inoculated with S. mutans 10449S, ate diet 2000CS (containing 56%
cornstarch) ad libitum, and, upon weaning and for 10 additional days, drank
demineralized water supplemented to 10% (w/v) with sucrose (SW) ad libitum.
During these 10 days, 6 of the 7 groups of rats were topically treated with a
slurried F(-)-free placebo toothpaste. On the 10th day after initial inoculation,
two groups were sacrificed, one which had been treated with the placebo and the
one which had been untreated. The remaining groups were then provided
unsupplemented demineralized water (DW), fed diet 2000CS, and topically treated
with either of 5 coded toothpastes: a slurry of the F(-)-free placebo, a similar
slurry of a conventional sodium fluoride toothpaste (Crest Regular) containing
about 383 ppm F-, or one of three prototype toothpastes formulated by Enamelon,
Inc. containing soluble calcium and phosphate salts. Two of these contained 377
ppm F- after mixing their components, either as sodium monofluorophosphate (E
MFP) or as NaF (E-NaF). The third prototype contained 0 ppm F- (E-w/o F). Test
items were applied to the dentition for one minute/day, five days/week. These 5
remaining groups were sacrificed 13 days after the DW provision. After
defleshing, heads were coded randomly and scored blindly for carious lesions. The
exchange of DW for SW was associated with highly significant reductions of 10449S
recoveries (p < 0.001), but there were no differences in recoveries among the
groups as a function of toothpaste type. Total mandibular and maxillary sulcal
and smooth surface caries scores were statistically significantly lower for the E
NaF-treated group at 23 days than for the 23-day placebo-, E-w/o F(-)-, and
conventional NaF toothpaste-treated group. Reductions were most impressive
quantitatively on approximal tooth surfaces, where both the E-MFP and E-NaF
groups had the lowest scores, but were also statistically significant at sulcal
surfaces for the E-NaF group. Thus, this study model can be used to detect
significant remineralization effects, as occurred with the prototype toothpaste E
NaF.
PMID- 10686859
TI - An in vitro assessment and a pilot clinical study of electrical resistance of
demineralized enamel.
AB - Electrical resistance measurement was evaluated in vitro and in vivo as a method
for comparing the remineralizing performance of toothpastes. In the in vitro
study, areas of sound enamel on 12 unrestored, mature, extracted human molars and
bicuspids, with electrical resistance readings greater than 99.99 M omega, were
demineralized to an electrical resistance of 1 to 4 M omega. The teeth were
divided into three groups. The change in electrical resistance was measured
following a 15 cycle regimen of treatment, demineralization and salivary soaking.
Treatments were five-minute exposures to either a 1:2 slurry in saliva of
Enamelon (E), a remineralizing fluoride-toothpaste also containing soluble
calcium and phosphate ions, a 1:2 slurry in saliva of Crest (C), a conventional
fluoride toothpaste (P), or to saliva alone. Demineralization was performed with
a 30-minute exposure to 0.1 M lactic acid 50% saturated with calcium
hydroxyapatite. The salivary soaking was 1 hour in duration. The mean electrical
resistance of the E, C and the saliva treated sites was 63.9 +/- 4.3, 37.6 +/-
9.5 and 2.1 +/- 0.7 M omega, respectively. The final resistance was statistically
different for each group (p < 0.05). A pilot clinical study was then conducted to
assess the electrical resistance technology in vivo. Eighteen adult subjects with
at least one site of early enamel caries with an electrical resistance between
1.0 M omega and 20.00 M omega were randomly assigned to either Enamelon, Crest,
or a non-fluoride placebo toothpaste and asked to brush twice daily. After three
months, the mean resistance of the test sites was 23.57 M omega for E, 9.61 M
omega for C and 13.24 M omega for P. However, the mean resistance changes did not
proceed consistently over time. At the end of the study, the electrical
resistance measurements on four sites out of twelve in Group E were suggestive of
remineralization, whereas measurements on one site out of ten were suggestive of
remineralization in Group C and two or three sites out of twelve were suggestive
of remineralization in Group P. Progression of demineralization was possibly
indicated in only one site, which was in Group C. There were insufficient
subjects for statistical significance in the pilot clinical study. There were
apparent problems with the variability of some measurements between visits in the
in vivo study. Overall, however, the results of both studies indicate that with
modifications to the equipment, electrical resistance measurements may be a means
of comparing the remineralization performance of toothpastes.
PMID- 10686860
TI - Treatment of orthodontic white spot lesions with a remineralizing dentifrice
applied by toothbrushing or mouth trays.
AB - This pilot study investigated the effect of a remineralizing fluoride dentifrice
(Enamelon) on newly formed incipient carious lesions using two methods of
application. Teenage orthodontic patients with obvious white spot lesions on
their teeth were selected to begin treatment within 30 days after debanding. At
baseline, the surface enamel of the test teeth was cleaned by air etching with 50
microns alumina at 150 psi. Lesion size (mm2) was measured using a calibrated
periodontal probe and surface appearance was quantified as shiny (0), dull (1),
or chalky (2). Twice daily for 3 months, one group with a total of 27 lesions
brushed with the remineralizing dentifrice, while a second group with 41 total
lesions brushed and used a mouth tray to apply the paste directly to the lesions
for 5 min. In order to promote treatment compliance, test group assignment was
based on subject and parental preference. After 1, 2, and 3 months, lesion size
was reduced by 5% (ns), 10% (p < 0.05) and 22% (p < 0.01), respectively, for the
brushing group, and 16% (p < 0.05), 37% (p < 0.01) and 30% (p < 0.01) for the
combined brushing and tray group, respectively. The dull appearance of the
lesions treated by brushing improved slightly over 3 months. However, the lesions
receiving combined brushing and tray applications became significantly (p < 0.01)
less dull by 28%, 44% and 61% after 1, 2, and 3 months, respectively, indicating
the formation of a shiny, intact surface layer. In conclusion, brushing with a
remineralizing dentifrice significantly reduced the size of new orthodontic white
spots within 2 months, while brushing combined with topical tray applications
reduced lesion size within 1 month with concomitant formation of a shiny enamel
surface layer. Thus, the combined brushing and mouth tray treatment significantly
accelerated the remineralization process.
PMID- 10686861
TI - Clinical evaluation of the effect of a remineralizing toothpaste on dentinal
sensitivity.
AB - Dentinal hypersensitivity is a common dental problem without a satisfactory
solution. Most therapies have focused on either trying to block the stimulation
of dentinal nerves or on sealing open dentinal tubules. This study evaluated, in
a double blind clinical trial, the effect of Enamelon, a dentifrice containing
sodium fluoride, calcium salts and phosphate salts (calcium separated from the
phosphate and fluoride by a plastic divider in the tube to prevent interaction)
on dentinal hypersensitivity over an 8-week period. A conventional OTC dentifrice
containing NaF without calcium and phosphate enhancement served as the control. A
third dentifrice, containing sodium monofluorophosphate enhanced by calcium and
phosphate salts, was also tested. Based upon subjective anecdotal information,
net numbers of sensitive teeth which became non-sensitive, and a logit analysis
of the change in the proportion of sensitive teeth over the study time period,
Enamelon was the most effective product, and the OTC control the least effective.
PMID- 10686862
TI - Evaluation of blood pressure in children and adolescents: a review.
AB - Hypertension in children has received minimal attention in the dental literature;
this may be the result of comparatively low interest in the subject by the
medical community. It is now believed that the processes causing cardiovascular
disease morbidity and mortality begin early in life. The implication for
prevention is that screening and intervention should commence in childhood.
Although the prevalence is lower than in adults, elevated blood pressure during
childhood is not uncommon. Dentists may be uniquely positioned to screen children
for hypertension. Children from poor families may not use medical services except
in emergencies, but may visit a dentist as part of Head Start or through other
state or federal programs. By incorporating blood pressure screening for children
as well as for adults and with appropriate referral, dentists may contribute to
the reduction of cardiovascular disease. This review presents a discussion of
blood pressure in children and adolescents, the epidemiology and etiology of
elevated blood pressure, the problems associated with hypertension, and
recommended procedures for measuring blood pressure in children and young adult
patients.
PMID- 10686863
TI - Clinical and ultrastructural study of natal and neonatal teeth.
AB - The present study was undertaken to evaluate the surface topography of mandibular
natal and neonatal incisors at the ultrastructural level using the scanning
electron microscope (SEM). The enamel of the teeth exhibited hypoplastic,
depressed areas and the incisal edge of natal tooth lacked enamel. In addition,
root formation of the teeth was not completed, which correlated with findings
that teeth may erupt without root formation.
PMID- 10686864
TI - Severe hypodontia: diversities in manifestations.
AB - The material comprises 33 cases, 12 boys and 21 girls with 4 or more lacking
teeth in the permanent dentition, randomly collected among patients referred to
the Department of Pedodontics, University of Bergen. The total number of lacking
teeth were 332, mean number in boys was 11.4, in girls 9.3, ranging from 4 to 24
(third molars excluded). The most prevalently lacking teeth were second premolars
in both jaws, maxillary lateral incisors, mandibular central incisors and
maxillary first premolars. The maxillary central incisors were the most stable
teeth, lacking in only one patient. The female group was closest to this
"classical" scheme by lacking teeth mostly in posterior segments. In males the
anterior segments were most often afflicted. There was no significant difference
between right and left sides in both sexes, but in girls the maxillary jaw was
more afflicted than the mandibular jaw. The individual analyses of cases showed
great diversities in the manifestation of hypodontia. Eighteen of them behaved
fairly "balanced" with respect to lack of teeth in the different quadrants. Six
cases were lacking most of the teeth in the maxillary jaw (total 34 maxillary
teeth versus 11 mandibular). Five cases were lacking most of the teeth in the
mandibular jaw (total 30 mandibular teeth versus 14 maxillary). One patient was
lacking 10 of his 12 front teeth, but only 4 of his 20 posterior teeth, and one
patient was lacking 12 of his 16 posterior teeth, but none of his front teeth.
The author cannot offer any explanation for these strange and varying patterns of
manifestations.
PMID- 10686865
TI - Gingivitis in children with malnutrition.
AB - The purpose of the current study was to compare the prevalence and severity of
gingivitis and plaque among 291 well- and malnourished children between the ages
of 4 to 7 years. Using the National Center for Health Statistics criteria, the
children were identified as normal (well nourished), having a height-of-age > 95%
of standard. Selected primary teeth of each child were assessed using the Plaque
Index (PlI) and the Modified Gingival Index (MGI). The results demonstrated a
100% prevalence of plaque and gingivitis. Also, there was no significant
difference in the PlI and MGI in the well-nourished and malnourished groups, nor
between males and females. However, there was a trend in the well-nourished group
to less plaque and gingivitis when broken down into different stature-by-age
percentiles.
PMID- 10686866
TI - Orthodontic treatment of a patient with multiple supernumerary teeth and mental
retardation.
AB - Supernumerary teeth may lead to impaction or ectopic eruption of maxillary
incisors, crowding, oronasal fistula, follicular cyst, migration of adjacent
teeth and root resorption. In this presentation, an 11-year-old male patient with
4 supernumerary teeth in the maxillary anterior region and a slight mental
retardation problem will be presented. After extraction of the supernumerary
teeth, the large space created by distal migration of central incisors was closed
by orthodontic treatment. Although initial patient compliance was weak and caused
difficulties in the course of treatment, orthodontic treatment was completed
successfully.
PMID- 10686867
TI - Newer Class I cavity preparation for permanent teeth using air abrasion and
composite restoration.
AB - This study attempts to determine a more effective cavity preparation design,
material selection and preparation technique for reducing microleakage in
posterior Class I esthetic restorations. An in vitro study using four different
cavity designs, for Class I restorations on permanent molars, prepared with two
different methods, and restored with three different restorative materials
(hybrid composites) was done to evaluate marginal microleakage, and voids
occurrence. Two hundred and forty extracted permanent molars were chosen and
evaluated for caries, visually, with a dental explorer, and with caries detector
dye. The teeth were then randomly divided in two groups (n = 120). In the first
group, Class I cavity preparations were performed with air-abrasion. In the
second group Class I cavity preparations were performed with #330 bur. The
results revealed that cavity preparations prepared with air-abrasion with or
without chamfer, and for cavity preparations done with a #330 bur with chamfer
and restored with Tetric Flow, had zero microleakage. Cavity preparations done
with air-abrasion, without chamfer, and for cavity preparations prepared with
#330 bur with chamfer and restored with Tetric Ceram, had zero microleakage
score. Cavity preparations done with air-abrasion with chamfer and restored with
Herculite had one tooth out of twenty with microleakage, and for cavities without
chamfer two teeth had microleakage. Cavity preparations prepared with a #330 bur,
without chamfer, and restored with Herculite XRV had four teeth out of twenty
with microleakage, and with a chamfer, two teeth had microleakage. These
differences were not statistically significant. When comparing Tetric Flow versus
Herculite XRV for void formation in cavity preparations prepared with Air
abrasion and a chamfer, Tetric Flow had significantly less voids, p < 0.001. When
comparing Tetric Ceram versus Herculite XRV for cavity preparations prepared with
Air-abrasion and a chamfer, Tetric Ceram had significantly less void formation, p
< 0.01 > 0.001. When comparing Tetric Flow versus Herculite XRV for cavity
preparations prepared with #330 bur and without a chamfer, Tetric Flow had
significantly less void formation, p < 0.02 > 0.01. When comparing Tetric Flow
versus Herculite XRV for cavity preparations prepared with #330 bur and a
chamfer, Tetric Flow had significantly less void formation, p < 0.001 > 0.001.
Caries detection results revealed that the caries detector dye method had
significantly higher caries detection scores than explorer p < 001, and than
visual inspection p < 0.001. Also inspection with explorer had significantly
higher scores than visual inspection p < 0.001.
PMID- 10686868
TI - Four types of topical anaesthetic agents: evaluation of clinical effectiveness.
AB - In this study, four anesthetic agents of different forms and contents, namely:
EMLA 5% Cream (lidocaine 2.5 percent, prilocaine 2.5 percent), Vision-Gel
(benzocaine 20 percent), Anesthetic Tabs (tetracaine hydrochloride 0.68 mg,
cincocain hydrochloride 0.02 mg), Xylocaine 10% aerosol (lidocaine 10 percent)
were evaluated in terms of effectiveness in decreasing the intra-oral injection
pain. Six groups each consisting of 20 children were constituted from 120
children aged between 10-15 years. The responses of the patients to the pain were
evaluated using a visual analogue scale. Consequently, of all the other
anesthetic agents used in the present study, Vision Gel was observed to be the
most effective.
PMID- 10686869
TI - The effect of physiological root resorption on the histological structure of
primary tooth pulp.
AB - The aim of this study was to determine, the effect of physiological root
resorption on the histological structure of healthy primary tooth pulp. Fourteen
canine teeth, which needed to be extracted for orthodontic purposes and in which
resorption had just begun (1st group, resorption did not exceed 1/3 of root
length) or was in advanced resorption stage (2nd group, resorption was between
1/2 and 2/3 of root length), were used for this study. After the extraction of
the teeth, they were prepared for histological examination. Then the samples were
examined using light microscopy. The result no difference was found which could
be detected by polarized light microscope that was related to physiological
resorption and histological structure of primary teeth pulp.
PMID- 10686870
TI - The effect of physiological root resorption on repair potential of primary tooth
pulp.
AB - The aim of this study was to determine, the effects of root resorption on repair
potential of healthy deciduous tooth pulps. Fourteen canine teeth which needed to
be extracted for orthodontic purposes and in which resorption had just begun (1st
group, resorption did not exceed 1/3 of root length) or was in advanced
resorption stage (2nd group, resorption was between 1/3 and 2/3 of root length)
were used for this study. Direct pulp capping treatment was implemented in vivo,
to 7 teeth in each group. Reparative dentin formation was determined three months
later following extraction. The teeth were examined histopathologically under
light microscope. As a result, in the teeth with different resorption levels,
dentin bridge formation in the capping area was observed. Although maturation of
the thin dentin bridges was completed in all teeth, maturation of the thick
dentin bridges was still continuing at the 90th day.
PMID- 10686871
TI - Diagnosis of dental caries: a comparison of three radiograph viewing techniques.
AB - Interproximal caries scores for identical surfaces were compared across the three
visualization techniques. First, the scores obtained by the naked eye method were
compared to the scores obtained using the magnified view box. The second
comparison looked at difference in scores between the magnified view box
technique and the D.E.T.E.C.T. machine. A third comparison between the naked eye
technique scores and the D.E.T.E.C.T machine scores was also made for each of the
two operators. The comparison of caries score between the magnified view box and
the digital image enhancement D.E.T.E.C.T. machine showed a more homogenous
result. More caries was scored by both operators using the digital image
enhancement system than with the view box technique. The difference in caries
scores between the two techniques assigned for every surface by the two operators
were statistically significant (p < 0.05). It is clear from this study that image
enhanced interpretations of conventional radiographs is a necessary step to fine
tune the caries diagnosis process.
PMID- 10686872
TI - Combined effects of argon laser irradiation and fluoride treatments in prevention
of caries-like lesion formation in enamel: an in vitro study.
AB - The sample of this study consisted of 10 human permanent molars, which were
sectioned into tooth quarters using slow speed diamond saw (Isomet), then a
quarter from each tooth was assigned to one of four treatment groups: A) control
(no treatment); B) argon laser only; C) argon laser plus neutral sodium fluoride
for 4 minutes; D) argon laser with zinc fluoride for 4 minutes; each tooth
quarter was coated with acid resistant varnish, leaving a window of 2 mm x 3 mm
of sound enamel exposed. The results were that teeth treated with argon laser and
then with zinc fluoride for four minutes have significantly reduced white
spotting or etching. Zinc fluoride and argon laser combination are particularly
effective in compensating for carbonate inclusion. It has a property of
stabilizing hydroxyapetite crystal and restoring the structural defects of this
crystal. Caries detection dye is a reliable diagnostic tool for white spot
lesions. It reduces the false positive and false negative results by 60%, when
compared with visual 16x magnification.
PMID- 10686873
TI - The effect of thyroid hormone on orthodontic tooth movement in rats.
AB - The major goals of this study were to determine the effects of different doses of
thyroxin on the rate of orthodontic tooth movement and the force-induced root
resorption. In this study fifty male Sprague--Dawley rats were divided into five
groups: a normal group with no intervention; a control group in which appliances
were placed and 10 ml/kg i.p./day normal saline was injected; and three thyroxin
groups in which appliances were placed and 5, 10 and 20/microgram/kg i.p./day L
thyroxin were administered, respectively. A fixed orthodontic appliance
consisting of a 5 mm closed-coil spring was ligated between the maxillary incisor
and maxillary first molar to deliver an initial force of 60 gm. The results
showed that administration of 20/microgram/kg i.p./day L-thyroxin significantly
increased the amount of orthodontic tooth movement (p < 0.001). The extent of
root resorption as seen from scanning electron micrographs decreased with
thyroxin administration.
PMID- 10686874
TI - Transposition of mesial and distal aspects of maxillary first molars: case
report.
AB - Congenital absence of one or more teeth, hypodontia, is the most common
developmental anomaly and is often accompanied by the presence of other tooth
anomalies. In this case two Japanese sisters have several congenitally missing
primary and permanent teeth and morphological abnormalities of maxillary first
molars. One sister has transposition of mesial and distal aspects of a maxillary
first molar, whose cusps display a normal shape. Another sister has maxillary
first molars, which look like maxillary second molars. Mesio-distally shift of
teeth is a very rare anomaly making this particular case important to analyze the
teeth formation and development.
PMID- 10686875
TI - Macrodontia in association with a contrasting character microdontia.
AB - The dental, genetic, radiological and dermatoglyphic findings of a 19-year-old
girl showing macrodontia of maxillary permanent central incisors in association
with a contrasting character, microdontia of maxillary permanent lateral and
mandibular primary central incisors and bilateral absence of maxillary first
premolars and missing of the right mandibular second premolar and peg-shaped
mandibular primary lateral incisors and canines were presented.
PMID- 10686876
TI - Congenital lower lip pits: case report and review of literature.
AB - A case of congenital lower lip pits is presented. The main characteristics of
these malformations, the importance of the diagnosis and the surgical treatment
are discussed.
PMID- 10686877
TI - Extensive, traumatic fractures of the orbit in war and peace time.
AB - Traumatic fractures of the orbit are fairly frequent injuries both in wartime and
in peacetime. Most often they are part of facial injuries but they can also be
isolated. They are followed by numerous symptoms such as eye dislocation,
enophthalmos, double vision, and often by various injuries of eye accessory
organs. The conservative treatment of these injuries has been mostly abandoned.
Surgical therapy--that is, the reconstruction of the original orbital shape and
volume as well as repositioning of orbital contents to their previous position-
has to be performed as soon as possible. In cases of neglected fractures it is
necessary to refracture the bone, reposition and fix the broken orbital
fragments, and then, concomitantly, reconstruct the orbital shape and volume as
well as reposition the orbital contents in their original position. In patients
with neglected injuries, results of surgical treatment (i.e., correction of eye
position, enophthalmos, and double vision) are considerably poorer than those
achieved after the surgical treatment of fresh injuries.
PMID- 10686878
TI - Temporomandibular joint biomechanical restrictions: the fluid and synovial
membrane.
AB - The authors analyze the functions of the synovial membrane and the chemical
physical properties of synovial fluid. In particular they evaluate the role
played by synovial fluid in the complex mechanism of the temporomandibular joint.
Every single part that belongs to the temporomandibular joint, together with the
stomatognathic apparatus, plays a specific and particular role according to the
dynamics and to the preservation of the correct temporomandibular joint
physiology. The physiological postural and functional relationship between the
various parts of the temporomandibular joint is guaranteed by a number of
biomechanical restrictions that lead and influence the regular execution of the
articular movements. The most involved biomechanical restrictions in the
temporomandibular joint are the temporomandibular ligament, the lateral disc
ligament, the bilaminar zone or retrodiscal tissue, the synovial membrane, and
the synovial fluid.
PMID- 10686879
TI - Histological examination of regenerated bone through craniofacial bone
distraction in clinical studies.
AB - The process of bone formation by distraction osteogenesis of the craniofacial
bone has been studied in animals. To our knowledge there are no published
findings in which histological examination of craniofacial distraction in humans
has been reported. Specimens were obtained from 10 patients who underwent
craniofacial distraction: 2 patients who underwent mandibular distraction, 7
patients who underwent midface distraction, and 1 patient who underwent nasal
bone distraction. These specimens were examined histologically. The results
revealed that 8 of 10 patients exhibited new bone formation. No cartilaginous
callus formation was observed in any of the specimens, which strongly suggests
that new bone was produced by intramembranous ossification during human
craniofacial bone distraction.
PMID- 10686880
TI - Velopharyngeal changes after maxillary advancement in cleft patients with
distraction osteogenesis using a rigid external distraction device: a 1-year
cephalometric follow-up.
AB - The effect of maxillary advancement on speech may have benefits on articulation
improvement but compromises velopharyngeal (VP) closure by increasing the
nasopharyngeal distance. The purpose of this study was to evaluate the static VP
anatomic changes on lateral cephalograms in patients who underwent maxillary
advancement through distraction osteogenesis (DO) with a rigid external
distraction device and to correlate these changes with clinical speech data.
Twenty-two patients (5 female and 17 male) underwent maxillary advancement
through DO utilizing a rigid external distraction device (age, 5.2 to 25.7 years)
with various diagnoses, including 13 unilateral cleft lip and palate (CLP)
patients, 5 bilateral CLP patients, 1 isolated cleft palate patient, 2 facial
cleft patients, and 1 patient with craniosynostosis. Lateral cephalograms of
preoperative, immediate postdistraction, and 1-year postdistraction were obtained
for analysis. Speech evaluation was performed preoperatively, immediate
postdistraction, and then at 6-month intervals, and included assessment of air
pressure flow, hypernasality, and articulation. With an average amount of 8.9 mm
maxillary forward advancement, 14% of patients (3 of 21) presented deterioration
in hypernasality. However, 57% of patients (12 of 21) demonstrated improvement in
articulation. The cephalometric analysis demonstrated an increase in
nasopharyngeal depth by 8.5 mm (1:1 ratio with bony movement) and velar angle by
14.1 deg. The length of the soft palate remained unchanged. The need ratio
(intersection of palatal plane and posterior pharyngeal wall-posterior nasal
spine/posterior nasal spine--tip of uvula) worsens after distraction. The
deterioration of hypernasality was related to the amount of forward distraction,
especially in patients without a preexisting pharyngeal flap (PF). Speech
evaluation is an important aspect concerning treatment planning for maxillary
distraction. The increase in nasopharyngeal depth may compromise VP closure. The
increase in velar angle was considered to be part of the compensation in the VP
mechanism. An adverse effect of a preexisting PF on maxillary distraction was not
observed; however, it prevented postoperative hypernasality.
PMID- 10686881
TI - The effect on facial growth of pediatric mandibular fractures.
AB - The incidence of facial fractures in the pediatric population is between 1.4% and
15% of all maxillofacial traumas. Forty-one percent of pediatric facial fractures
involve the mandible. No study has commented on the incidence of mandibular
fractures that go on to develop growth disturbances leading to asymmetry and
malocclusion. A retrospective chart review was carried out that identified and
followed 88 children who sustained mandibular fractures and presented to The
Hospital for Sick Children in Toronto during the 13-year period from 1980 to
1993. Patient follow-up ranged from 2 to 15 years, and was performed via phone
survey and medical/orthodontic chart review. Patients who required orthodontics
and orthognathic surgery were identified. Results indicated that a pediatric
mandibular fracture does not lead to a higher incidence of orthodontic
intervention. Furthermore, children younger than 4 years or older than 12 years
rarely require orthognathic surgery to correct facial growth disturbances
following mandibular fractures. In contrast, 22% of children age 4 to 7 years,
and 17% of children age 8 to 11 years required orthognathic surgery to correct
facial growth disturbances following mandibular fractures. Condylar fractures
were the most common site of mandibular fracture, and led to facial asymmetry
most frequently.
PMID- 10686882
TI - Frontotemporal fasciocutaneous island flap for facial aesthetic subunit
reconstruction.
AB - The frontotemporal fasciocutaneous island flap is a useful source of tissue for
correcting aesthetic units of the face. The quality of the tissue may be
enhanced, and a successful color and texture match may be achieved. This flap is
based on the temporal vessel system and its own fascia. Its provides excellent
venous drainage and its pedicle length and arc of rotation may be increased. The
donor scar is hidden under the hair-bearing area. The frontotemporal
fasciocutaneous island flap was used in patients with inferior eyelid defects,
for cheek reconstruction, for providing coverage of superior and inferior lip
defects, for restoring the normal anatomy of columellar defects, and for
reestablishing the contour of menton defects. The frontotemporal fasciocutaneous
island flap was employed successfully in 9 patients at the Hospital Gea Gonzalez.
The wide treatment possibilities for the reconstruction of aesthetic units in the
face with the frontotemporal fasciocutaneous island flap are illustrated.
PMID- 10686883
TI - Effect of human bone morphogenetic protein 2 implant on tooth eruption in an
experimental design.
AB - This study evaluated the influence of recombinant human bone morphogenetic
protein 2 (rhBMP-2) on the development and eruption of the secondary dentition.
Primary premolar tooth extraction sockets in 12 16-week-old felines were
implanted with either rhBMP-2, in collagen sponge or with buffer/absorbable
collagen sponge (ACS). Unoperated jaw quadrants served as controls. Experimental
conditions were randomized between jaw quadrants in all animals. Two animals
receiving rhBMP-2/ACS and buffer/ACS in two quadrants per implant were sacrificed
at 4 weeks postsurgery. Ten animals receiving rhBMP-2/ACS (two quadrants),
buffer/ACS implants (one quadrant), and one quadrant serving as an unoperated
control were evaluated at 12 weeks postsurgery. Clinical assessments included
healing, eruption patterns, and crown development. Radiographic assessments
included tooth development, eruption patterns, and bone formation. Histological
observations were also made from the 4-week animals. The secondary dentition
remained unerupted at 4 weeks postsurgery. Histological analysis showed normal
alveolar bone coronal to the erupting teeth in rhBMP-2/ACS-implanted quadrants.
At 12 weeks postsurgery, all teeth were erupted without differences between
quadrants. Clinically, the crowns of all teeth were normal. Radiographs suggested
that teeth in rhBMP-2/ACS- and buffer/ACS-implanted jaw quadrants exhibited
similar tooth development and eruption patterns as the normal control. The
evidence from this study suggests that surgical implantation of rh-BMP-2/ACS in
the pathway of the developing and erupting secondary dentition does not interfere
with the normal development and eruption patterns of the teeth.
PMID- 10686884
TI - Attachment of the deep temporal fascia to the zygomatic arch: an anatomic study.
AB - It is generally acknowledged that the superficial layer of the deep temporal
fascia attaches to the lateral surface and its deep layer along the medial
surface of the zygomatic arch. However, Ramirez asserts that the superficial and
the deep layer of the deep temporal fascia fuse consistently approximately 1 cm
above the upper ridge of the arch and attach to the outer surface of the arch,
blending with the superficial fascia of the masseter muscle. In this study the
authors clarify the precise anatomic relations between the fascia and the
zygomatic arch. Coronal sections crossing the midpoint between the
zygomaticotemporal suture and the tubercle of zygoma were observed grossly and
histologically in 32 hemifaces from 16 Korean adult cadavers. This study
demonstrates that the superficial and the deep layers of the deep temporal
fascial fuse and insert onto the superior margin of the arch in 18 dissections
(56%) and insert onto the superolateral surface in 14 dissections (44%). The
contacting surface of the fused deep temporal fascia to the periosteum of the
zygomatic arch is less than 2 mm. The following route is safer and is recommended
for reaching the zygomatic arch region: Just above the split of the deep temporal
fascia, a dissection is carried through the deep temporal fasica, continuing
downward to the superior margin of the arch along the undersurface of the fascia.
At this spot the periosteum of the arch is dissected.
PMID- 10686885
TI - Correction of unilateral cleft lip nasal deformity using the sliding sulcus
procedure.
AB - The nose can be conceptualized as a soft-tissue structure, the orientation of
which depends externally on its osseous foundation and internally on the shape
and position of its cartilaginous struts. If the soft-tissue envelope of the
cleft nose can be given volumetric symmetry, if it can be positioned correctly in
space, and if physical forces imposed on it by cleft pathology (i.e., abnormal
muscle insertion), then the internal rearrangement or augmentation of the
cartilaginous components can await definitive operation later in childhood. The
sliding sulcus operation is a subperiosteal procedure designed to address the
problems of division, deficiency, displacement, and distortion, taking advantage
of its unique ability to mobilize tissues from the maxilla. Surgical techniques
are presented with clinical examples.
PMID- 10686886
TI - Congenital infiltrating lipomatosis of the face.
AB - Congenital infiltrating lipomatosis of the face is a rare clinical entity. Since
it was first described by Slavin and colleagues in 1989, only a few cases have
been reported in the literature. A 6-year-old girl with congenital infiltrating
lipomatosis of the right side of the face is presented, and treatment modalities
are discussed.
PMID- 10686887
TI - Transoral maxillary distraction osteogenesis of an unrepaired bilateral alveolar
cleft.
AB - Distraction osteogenesis has gained acceptance as a viable modality for
lengthening hypoplastic skeletal structures in the maxillofacial region. A case
of the application of this technique to advance the maxilla in an unrepaired
bilateral alveolar cleft via a transoral approach is presented. The distraction
devices were applied bilaterally to the zygomatic buttress region with the
activating arms protruding from the oral cavity. A high Le Fort I osteotomy was
performed under general anesthesia and, prior to distraction, the three maxillary
segments were unified with an occlusal acrylic splint. Activation was begun 6
days after placement, at a rate of 1 mm per day, until the planned maxillary
advancement had been achieved. An 8-week period of consolidation was allowed
prior to removal of the devices.
PMID- 10686888
TI - Congenital trismus secondary to masseteric fibrous bands: endoscopically assisted
exploration.
AB - The authors present an 18-month-old female infant with congenital trismus.
Computed tomography and magnetic resonance imaging were not helpful in
determining the cause. A surgical endoscope was used to explore her
temporomandibular joints and temporal fossae, thus avoiding the morbidity of a
bicoronal incision. The cause was bilateral fibrous bands on the anterior border
of the masseter muscles. Incision of these fibrous bands led to relief of the
trismus. This finding is consistent with a previously described variant of the
Hect-Beals-Wilson trismus-pseudocamptodactyly syndrome. This patient, however,
had no evidence of the autosomal dominant inheritance pattern nor did she exhibit
pseudocamptodactyly, both of which are generally ascribed to this syndrome.
Unfortunately the trismus recurred 3 months postoperatively.
PMID- 10686889
TI - Numb chin syndrome secondary to metastatic breast disease.
PMID- 10686891
TI - Dental group practice or 2 + 2 = synergy.
PMID- 10686890
TI - Orofacial pain update. 2.
AB - This article is the second of a two part series, intended to update dentists
regarding some of the current issues associated with pain management in the
facial region. Part One presented a look at what constitutes orofacial pain and
what should be included in a comprehensive evaluation prior to treating facial
pain. The second part of this article focuses on levels of education, standard of
care issues, specialty status and implications on how care is delivered.
PMID- 10686892
TI - Dental radiology for the new millennium.
PMID- 10686893
TI - The exceptional office vs. the perfect office.
PMID- 10686894
TI - Feel-based design: a reason to endorse ergonomic standards.
PMID- 10686895
TI - Treatment of periodontal diseases: what treatment works, and what's new.
PMID- 10686896
TI - Latex hypersensitivity and dentistry.
PMID- 10686897
TI - A case report: recognizing factitious injuries secondary to multiple eating
disorders.
AB - This report describes the uncommon problem of a female patient diagnosed with an
eating disorder, bulimia nervosa, who reported self-mutilating dental factitious
behavior. The case presents a serious diagnostic and management problem.
Notwithstanding the clinical appearance of the dentition, a thorough medical
dental history was essential for this uncommon diagnosis.
PMID- 10686898
TI - Clinical crown lengthening: restorative considerations.
PMID- 10686899
TI - Patient records: growing importance.
PMID- 10686900
TI - Periodontal disease and heart disease--a connection.
PMID- 10686901
TI - Oral bone loss associated with menopause.
PMID- 10686902
TI - Multiple supernumerary teeth: literature review and case report.
AB - This paper provided information regarding the classification, etiology,
prevalence, sequelae and treatment of supernumerary teeth. A case of multiple
supernumeraries in a healthy pediatric patient was presented.
PMID- 10686903
TI - Levi Spear Parmly: the apostle of dental hygiene.
AB - Dr. Levi Spear Parmly (1790-1859), an influential American figure in the field of
dental prevention, introduced flossing as the most efficient way to prevent
dental disease. Dr. Parmly practiced in the United States, England and France.
Many of his ideas about controlling dental diseases are still highly applicable
to modern clinical practice. In this century, Dr. Charles C. Bass (of New
Orleans) and Dr. Sumter S. Arnim (of Houston) rediscovered, expanded, and
publicized the principles, ideals and practices of Dr. Parmly. As a result,
Parmly's concepts relating to oral disease causation and control continue to
influence today's dental practitioners. His seminal work and thoughts concerning
preventive dentistry are presented in this biographical paper.
PMID- 10686904
TI - Doc Holliday's dental chair.
AB - John Henry Holliday, DDS, was one of the best-known dentists of the United
States. However, little is known about his actual practice of dentistry. This
article discusses a dental chair that was used by Doc and shows where it fits
into his dental life.
PMID- 10686905
TI - Toothaches and death.
AB - Deaths from dental abscesses today are so rare, that it is difficult to fathom
that only 200 years ago, this was a leading cause of death. When the London
(England) Bills of Mortality began listing the causes of death in the early
1600's, "teeth" were continually listed as the fifth or sixth leading cause of
death. (This does not include the category of "Teething" which was probably
erroneously blamed for many children's deaths. As we examine several historic
factors of this period, it is apparent that the number of deaths attributed to
"teeth" in the seventeenth and eighteenth centuries was probably fairly accurate,
and it was not antibiotics, nor the discovery of asepsis, that brought about the
dramatic reduction in these dental mortalities, but two much earlier dental
innovations.
PMID- 10686906
TI - Dentistry on stamps. Tiradentes.
PMID- 10686907
TI - Freud's cancer.
PMID- 10686908
TI - Dr. W. Harry Archer, DDS, MA, 1905-1980 a life of dedication to oral surgery.
AB - The life of the American oral surgeon Dr. W. Harry Archer was one that affected
and inspired, and sometimes incensed, those who knew him and those who would
follow him. His life long devotion to the dental specialty of oral surgery was a
driving force that caused dramatic changes in aspects of not only oral surgery
but of dentistry as a whole. His excellence in leadership, teaching, research,
and writing were among his many accomplishments that firmly place him among the
eternal giants of the dental community.
PMID- 10686909
TI - Thomas Lea Buckingham, MD, DDS, (1816-1883).
AB - Miller, farmer, mechanic, dry goods merchant, dentist, author, physician,
teacher, inventor, and fourteenth president of the American Dental Association,
take your pick, for Thomas Lea Buckingham without feigning, embraced that menu to
the brim--the verge beyond which, only a pittance of dentists might succeed.
Nevertheless, the facts lie untouched--a testament to one of dentistry's most
brilliant, unassuming, and dedicated disciples. Loved by his students and
respected by his peers, Thomas Lea Buckingham reached new heights in garnishing
respect from his colleagues. Sharing his knowledge, Dr. Buckingham profusely
wrote about his findings, being affirmed by at least 25 dental periodicals (many
with multiple contributions), over a period of thirty-four years, from 1850 to
1884. His principal writings appeared in Dental Cosmos, Johnston's Dental
Miscellany, New York Odontologic Society Transcripts, Odontologic Society of
Pennsylvania, American Dental Association Transactions, Dental Items of Interest,
Pennsylvania Journal of Dental Science, Dental News, Dental Jairus, Missouri
Dental Journal, Dental Registrar, New England Journal of Dentistry, and the
British Journal of Dental Science. Upon Buckingham's death, noted dentists of his
era spoke with love and respect of this exceptional dentist. This paper
highlights the maturation of a minimally educated miller, who, with determination
and purpose, rose to the pinnacle of his selected professions and garnered the
love and respect of his fellow men.
PMID- 10686910
TI - Memories of oral health and dentistry in the 19th century: advertising trade
cards.
PMID- 10686911
TI - The explorer.
PMID- 10686913
TI - Basil Manly Wilkerson: dental inventor extraordinaire.
PMID- 10686912
TI - Henry Daniel Cogswell, DDS (1819-1900): a temperance advocate, philanthropist and
builder of ice-water fountains.
AB - Henry Daniel Cogswell (Fig. 1), the second of five children, was born in Tolland,
Connecticut on March 3, 1819. His father, George Washington Cogswell, was a
general carpenter, architect and builder of moderate circumstances. In 1827, when
Henry was eight, his mother died. The following year, Henry's father moved to
Orwell, (Oswego County) New York, in hopes of improving his financial condition.
Henry was left behind in the care of his paternal grandfather, who died several
months later, leaving the 10-year old boy, stranded and forced to rely upon his
own resources. (In those times, when families were separated, individual members
had limited means of locating one another.)
PMID- 10686914
TI - Tobacco and oral health.
PMID- 10686915
TI - Gleanings about dentistry from the world of literature (eighteenth in a series).
PMID- 10686916
TI - Giuseppangelo Fonzi: industrial fabrication promoter of porcelain prosthetics.
PMID- 10686917
TI - Veterinary dentistry: its origin and recent history.
PMID- 10686918
TI - Obituary: Norman Harry Olsen, DDS, MSD.
PMID- 10686919
TI - Survival of the fittest.
PMID- 10686920
TI - Update in periodontology.
PMID- 10686921
TI - The periodontal aspect of anterior aesthetics.
PMID- 10686922
TI - Osseointegrated implant failures.
AB - This article discusses the criteria used for implant success and failure, the
classification of implant failures, the causative factors, and diagnosis of the
failing and failed implant. In spite of the impressive success rates of
osseointegrated dental implants, failures occur and in some studies the incidence
of failure is high. Many studies do not use objective criteria to define success
and confuse survival with success. The criteria used affect reported success
rates. Implant failures may occur early (primary) after implant placement or
after the implant is loaded (secondary). There is no single aetiological factor
and failures have been attributed to poor surgical technique, host factors that
impair healing, poor bone quality, peri-implant infections, poor prosthesis
design and traumatic loading conditions. Early diagnosis of problems is critical
and every effort should be made to treat the problem while the damage can still
be managed or even reversed.
PMID- 10686923
TI - Enhancement of bone ingrowth into collagen/HA composite implants using e-PTFE
membranes.
AB - The objective of this investigation was to study the effectiveness of expanded
polytetrafluoroethylene (e-PTFE) membranes for enhancement of bone ingrowth
through subperiosteally implanted collagen/HA composite blocks. Twelve rabbits
aged 12-15 months served as the experimental animals in this study. Two
compressed Collagen/HA composite blocks in the shape of two attached cylinders of
different diameters were inserted into two defects of each rabbit calvarium, the
smaller cylinder being intrabony, the larger subperiosteal in location. One of
the two implants was covered with non-resorbable e-PTFE membrane. The other
implant was left uncovered. Specimens were obtained at 4, 8, and 12 weeks. While
the implant specimens on the membrane side showed progressive bone formation
between and around HA particles at the subperiosteal extrabony locations, the HA
particles on the non-membrane side were surrounded and separated by dense fibrous
tissue. At intraosseous sites, HA particles were surrounded by new bone
throughout the defect on the membrane side, but new bone formation occurred only
along the periphery on the non-membrane side. It appears that guided tissue
regeneration may be used to enhance new bone formation around and between
subperiosteally implanted HA particles.
PMID- 10686924
TI - Core build-up materials and techniques.
PMID- 10686925
TI - Restoration of endodontically treated teeth with posts and cores.
AB - This article is a review of the current technique and materials used in the
restoration of endodontically treated teeth with post and core materials and
procedures. It is intended to aid clinicians in making selections which are
appropriate to their individual practices through the evaluation of relevant
literature about the restoration of endodontically treated teeth.
PMID- 10686926
TI - The Catholic University of Ireland (1854-1908).
PMID- 10686927
TI - Performance evaluations--three sides of the coin.
PMID- 10686928
TI - Mercury amalgam safety: a review.
PMID- 10686929
TI - Exposure incidents: protective measures and action strategies.
PMID- 10686930
TI - Prosthetically determined implant placement for the partially edentulous ridge: a
reality today.
PMID- 10686931
TI - Management of occupational exposures to bloodborne viruses: risk and risk factors
for disease transmission.
PMID- 10686932
TI - Are we meeting the oral health needs of our pediatric patients?
PMID- 10686933
TI - Changing perspectives in the management of the preschool child.
PMID- 10686934
TI - Advantages of new restorative materials in dental care for children.
PMID- 10686935
TI - The vital pulpotomy in primary molars.
AB - The vital formocresol pulpotomy is a useful technique to regain satisfactory oral
health. Proper evaluation and diagnosis is crucial in order for the dentist to
select the pulpal therapy that offers the best chance of long-term success with
the fewest complications.
PMID- 10686936
TI - Mutation analysis of BRCA1, TP53, and KRAS2 in ovarian and related pelvic tumors.
AB - Cancer may be viewed as a genetic disease resulting from critical mutations that
disrupt normal cell growth. To characterize the involvement of the BRCA1 and TP53
tumor suppressor genes and of the KRAS2 protooncogene in gynecologic cancer,
mutation analysis of these genes was conducted in pelvic tumors of 85 patients
that included 49 epithelial ovarian carcinoma cases. The 85 pelvic tumors
contained 5 tumors with BRCA1 mutations, 33 with TP53 mutations, and 1 with a
KRAS2 mutation. Each of the BRCA1 and KRAS2 mutations, and 25 of the TP53
mutations, were in ovarian carcinomas. Four of the BRCA1 mutations were germline
and 1 was somatic. The 4 patients with germline BRCA1 mutations had an early age
of disease onset (33-48 years) relative to the mean age of onset (58 years) of
all 49 ovarian carcinoma patients, and 3 of these 4 patients had a family history
of ovarian or breast cancer. None of the 4 tumors with germline BRCA1 mutations
had a KRAS2 mutation or a TP53 mutation, despite a 51% frequency of TP53
mutations in the 49 ovarian carcinomas. Three of the 4 tumors with germline BRCA1
mutations retained a wild-type BRCA1 allele. The tumor with the somatic BRCA1
mutation contained a TP53 mutation and had no evidence for wild-type BRCA1 and
TP53 alleles. These data suggest that both BRCA1 and TP53 were inactivated in 1
of 49 ovarian carcinomas. Moreover, mutational inactivation of both BRCA1 and
TP53 did not occur in 4 tumors with a germline BRCA1 mutation. It has been
proposed that tumorigenesis in cells with a heterozygous BRCA1 mutation requires
inactivation of the wild-type BRCA1 and TP53 alleles, which results in genomic
instability and acquisition of mutations in protooncogenes. Clearly, mutational
inactivation of TP53 and the wild-type BRCA1 allele in ovarian tumors with a
heterozygous, germline BRCA1 mutation is not an absolute requirement for tumor
formation. It is possible that these alleles may be inactivated by nonmutational
mechanisms or that other tumor formation pathways exist.
PMID- 10686937
TI - Coexistence of several unbalanced translocations in a case of neuroblastoma: the
contribution of multicolor spectral karyotyping.
AB - Spectral karyotyping (SKY) is based on the simultaneous hybridization of a set of
24 chromosome-specific DNA painting probes, each labeled with a different fluor
combination. Automatic classification, based on the measurement of the spectrum
for each chromosome, was applied to metaphases obtained from the affected bone
marrow of a neuroblastoma case. Spectral karyotyping allowed the identification
of chromosomal aberrations that could not be identified by the use of the G
banding technique, and revealed a number of gains and unbalanced translocations.
PMID- 10686938
TI - Phenotypic and genotypic diversity of human neuroblastoma studied in three IGR
cell line models derived from bone marrow metastases.
AB - Metastatic stage IV neuroblastoma tumors, as well as cell lines derived from
them, are highly malignant and rapidly fatal. To determine whether malignant
potential of these cells might be influenced by stromal tissue at sites
frequently involved in metastasis, we initiated primary cultures from bone marrow
of three patients (331, 337, and 91) with stage IV neuroblastoma. All three
explants contained two distinct cell populations, malignant neuroblasts (Nb-type)
and substrate adherent stromal-like (Str-type) cells. The cell types were
separated at the first passage and studied by cytogenetic, molecular, and
immunocytochemical methods. Karyotypic analyses after 3-6 passages in vitro
revealed the presence of unique chromosomal abnormalities in Nb-type cells of all
three lines: (1) der(1)t(1;7) (p32;q11) and der(5)t(5;17)(q35;q21) in
pseudodiploid IGR-N-331 neuroblasts; (2) der(1)t(1;17)(p35;q21-22) x 2 and
der(7)t(7;7)(p21;q21) in IGR-N-337 hyperdiploid neuroblasts; and (3) more than
six rearranged chromosomes in two related subpopulations of hypodiploid IGR-N-91
neuroblasts. Neuroblastic cells from all three tumors amplified MYCN 25- to 50
fold (with amplified genes visible as dmin or, in one IGR-N-91 subline, as an
hsr(14)[q32]) and expressed N-CAM. Str-type cells from tumors 331 and 337 had a
normal diploid karyotype, did not express either N-CAM or S-100, and are probably
normal bone marrow fibroblasts. By contrast, S-100 negative Str-type IGR-N-91
cells were hypodiploid and shared at least two unbalanced translocations,
der(4)t(1;4)(q12;p15) and der(2)t(2;10;17)(p14;q11;q22), with neuroblastic
counterparts, indicating that "stromal" cells and malignant neuroblasts had a
common tumor cell origin. Thus, the Str-type cells of IGR-N-91 are examples of S
type phenotypic variants frequently described for long-term human neuroblastoma
cells lines in vitro, but not previously observed in vivo.
PMID- 10686939
TI - Atypical chronic myeloid leukemia with der(20)t(17;20)(q21;q13).
AB - We present a case of atypical chronic myeloid leukemia that developed blastic
transformation four months after initial presentation, with the blast cells
showing multilineage antigen expression. A novel karyotypic abnormality,
der(20)t(17;20)(q21;q13), was found in bone marrow cells at diagnosis. The
potential role of such an aberration in leukemogenesis is discussed.
PMID- 10686940
TI - Genetic studies on a family with acute myelogenous leukemia.
AB - Seven cases of myelogenous leukemia--two acute erythroleukemia (AEL), four acute
myelogenous leukemia (AML), and one acute myelomonocytic leukemia (AMMoL)--were
found in 22 members of three consecutive generations of a family in the past 16
years (1973-1989). By using cytogenetic, hematologic, and biochemical analyses of
those surviving in this family, we also found four members who might develop
leukemia in the future. Southern blot analysis of one of the four members and her
father (an acute leukemia patient) with a v-ERBB probe showed that the gene
abnormalities consisted of a c-ERBB rearrangement (hereditary) and a
rearrangement/amplification of the same gene.
PMID- 10686941
TI - Trisomy 1q generating translocations in Wilms tumor.
AB - Unbalanced translocations generating trisomy of 1q are common in Wilms tumor
(WT). We present eight unbalanced 1q translocations from seven tumors and a
review of the literature. An unbalanced translocation that results in a
der(16)t(1q;16q) chromosome represents more than half of the published +1q
generating translocations in WT. This translocation is also common to many other
tumor types. Four of the tumors presented here contained this chromosome and,in
two cases, it was the primary acquired cytogenetic abnormality within the tumor.
The other four translocations involved 9q31, 9q34, 17p1?, and 21p11 as the
partner to 1q. The chromosome 17 and 21 translocations occurred within the same
tumor as apparently independent events. In contrast with the 16q translocations,
these other translocations were secondary cytogenetic events, thereby indicating
a role in tumor progression rather than initiation. Probes mapping to 1q12 and
1q21 were employed for fluorescence in situ hybridization and it was demonstrated
that different 1q breakpoints are possible. In this series, the majority of
breakpoints either mapped to 1q12 or were centromeric to this region.
PMID- 10686942
TI - Characterization of the C-MYC amplicon in a case of acute myeloid leukemia with
double minute chromosomes.
AB - We have characterized the double minute chromosomes in a case of acute myeloid
leukemia (AML). Southern blot analysis showed that the C-MYC was amplified.
Further analysis with probes located both 3' and 5' of MYC indicated that the
amplicon was at least 700 kb in size, extending from the papilloma virus
integration site situated 500 kb 5' of MYC to the PVT gene located 280 kb 3' of
MYC. This appears to be the largest MYC-containing amplicon in human leukemia.
PMID- 10686943
TI - Unusual chromosome patterns of renal cell carcinomas common to two brothers.
AB - In this study, we describe two renal cell carcinomas (RCC) that occurred at the
same time in two brothers, yielding information on the carcinogenic process. We
used flow cytometry (FCM) to evaluate nuclear DNA content, and performed
cytogenetic analysis. We also carried out fluorescence in situ hybridization
(FISH) with a panel of centromeric probes for chromosomes 3, 7, 8, 9, 12, 17, 20,
and Y in interphase cells. Flow cytometry analysis revealed diploid histograms in
the tumor and "nonmalignant" samples of patient 1, while an aneuploid cell
subpopulation was found in the tumor and "nonmalignant" samples of patient 2.
Tumor samples from the two brothers were studied by FISH, and had common
numerical chromosome aberrations: trisomy of chromosomes 3 and 7, and monosomy
and trisomy of chromosomes 9 and 17. Moreover, in normal samples from both
brothers, we found monosomy 9, and in a normal sample from patient 1, monosomy
17. Cytogenetic analysis revealed trisomy 3 in some cells grown from normal
kidney tissue of each brother. The identification of the same chromosome
alterations in both brothers appears to provide evidence of an unusual process of
carcinogenesis, probably due to a common genetic basis.
PMID- 10686944
TI - Inflammatory myofibroblastic tumor with HMGIC rearrangement.
AB - Inflammatory pseudotumors or inflammatory myofibroblastic tumors (IMT) are
lesions of extreme heterogeneity showing a highly variable mixture of bland
looking spindle cells, inflammatory cells, and collagen fibers. We describe our
results of molecular cytogenetic and rapid amplification of cDNA ends (RACE-PCR)
studies on an IMT characterized by a translocation involving 12q15. Chromosomal
aberrations involving this region are very frequent among other benign tumors,
such as lipomas, uterine leiomyomas, or pulmonary chondroid hamartomas. Recently,
we have shown that, by these structural chromosomal aberrations, the HMGIC gene
is affected. Fluorescence in situ hybridization (FISH) analysis and 3' RACE-PCR
on cells of the present case of an inflammatory myofibroblastic tumor indicated
an intragenic rearrangement of HMGIC, resulting in an aberrant transcript of that
gene. Clonal cytogenetic aberrations have been described in very few cases of
IMT. The results presented herein indicate that this case of IMT represents a
true benign mesenchymal neoplasm associated with, or due to, a rearrangement of
HMGIC.
PMID- 10686945
TI - SiMa, a new neuroblastoma cell line combining poor prognostic cytogenetic markers
with high adrenergic differentiation.
AB - We describe the establishment and characterization of a new neuroblastoma (Nb)
cell line, SiMa, carrying the major recurrent chromosome changes associated with
poor prognosis Nb, including amplification of N-MYC by formation of double
minutes (dmin), der(1)t(1;17)(p35;q12) and der(22)t(17;22)(q22;p13), and loss of
chromosome 11, documented at both initiation and late passage. In contrast to
these cytogenetic stigmata of poor prognosis, analysis of catecholamine synthesis
by high pressure liquid chromatography (HPLC) measurement revealed an advanced
degree of adrenergic differentiation with high rates of 3,4
Dihydroxyphenylalanine (DOPA), noradrenaline, homovanillic acid (HVA), and
vanillylmandelic acid (VMA) production. Contrastingly advanced differentiation
and poor prognostic genetic markers combine to render SiMa a unique instrument
for investigating the pathology and therapy of Nb.
PMID- 10686946
TI - A man with natural killer cell lymphoma showing 46,XX and deletion 6q.
AB - Specific chromosomal abnormalities have been shown to be associated with certain
types of leukemia and lymphoma. We and others have recently demonstrated
del(6)(q21q25) as being strongly associated with natural killer cell
lymphoma/leukemia. In this report, we describe a case of natural killer cell
lymphoma with a clonal chromosomal abnormality of 46,X,-Y,+X,t(2;9)(q31;p24),
del(4)(q21q25),del(6)(q21q23), and propose that the region 6q23 is probably an
important site of genetic alteration in this group of tumors.
PMID- 10686947
TI - DNA copy number losses at 1p32-pter in monozygotic twins concordant for breast
cancer.
AB - To find similarities that may possibly indicate novel mutations, we performed
comparative genomic hybridization (CGH) analysis following degenerate
oligonucleotide primed polymerase chain reaction (PCR) for DNA obtained from
unique material of breast cancer that developed in monozygotic twin-pairs.
Polymerase chain reaction amplification was successful in 12 samples for 11
patients, including 3 pairs. Six samples exhibited DNA copy number changes. Gains
(76%) were more frequent than losses (24%). Gains or high-level amplifications in
8q were present in all but 1 of the abnormal cases. Frequent gains were detected
with a minimal common overlapping region at 5p (4 cases), at 1q25-qter (3 cases),
and at 20q12-qter (2 cases). The most frequent loss, detected in half of the
abnormal cases, was at 1p32-pter. One twin-pair showed similar changes in 4
chromosomal locations involving loss of 1p32-pter and gains in 1q25-qter, 5, and
8q.
PMID- 10686948
TI - A novel chromosomal rearrangement associated with therapy-related acute leukemia.
AB - We describe a 7-year-old girl with therapy-related acute myeloid leukemia (AML)
associated with a single and novel karyotypic abnormality. The patient had been
treated with alkylating agents and etoposide for hypothalamic pilocytic
astrocytoma at age 17 months, and developed mixed lineage AML. Cytogenetic
analysis of the leukemic blasts showed 46,XX,der(7)t(7;11)(q22;q14) in all cells
examined. Southern blot analysis revealed three copies of an unrearranged MLL
gene on chromosome 11q. This is the first report of a triplicated, unrearranged
MLL gene in association with a deletion of 7q anomaly and an unbalanced
translocation in therapy-related leukemia.
PMID- 10686949
TI - Translocations (X;10)(p22;q24) and (1;10)(q21;q11) in a follicular adenoma of the
thyroid without apparent involvement of the RET protooncogene.
AB - We report here the cytogenetic analysis of a follicular adenoma of the thyroid
which revealed an abnormal clone with a t(X;10)(p22;q24) and a t(1;10)(q21;q11)
together with normal cells. Fluorescence in situ hybridization (FISH) with YACs
273E3 and 344H4, which are located on 10q11.2 and are specific for the RET
protooncogene, showed no abnormalities. It would therefore appear that this gene
is not involved in the particular tumor, as has been reported in a number of
papillary thyroid carcinomas. Several chromosomal aberrations have been suggested
as been specific for follicular thyroid adenoma. However, until now, only a few
such cases have been reported which involve structural abnormalities of
chromosomes 10q11.2 and 10q24. We believe this to be the first report of a
follicular thyroid adenoma with a t(X;10)and a t(1;10).
PMID- 10686950
TI - Detection of MLL gene self-fusions by RT-PCR and automated fluorescent DNA
fragment analysis.
PMID- 10686951
TI - Constitutional (5;18) in a patient with aplastic anemia.
PMID- 10686952
TI - Translocation (5;19)(q33;q13) as the sole abnormality in a case of refractory
anemia with excess of blasts in transformation.
PMID- 10686953
TI - Second case of t(6;7)(p21;q36) in acute lymphoblastic leukemia.
PMID- 10686954
TI - Complex rearrangement of chromosomes 1, 7, and 16 in chronic myelomonocytic
leukemia.
PMID- 10686955
TI - [The correlation between the CD4 count in HIV-positive patients and the
radiological findings in diseases of the paranasal sinuses].
AB - BACKGROUND AND OBJECTIVE: Sinusitis is a frequent and typical disease in HIV
positive patients. It was the aim of this study to examine retrospectively
computed tomograms (CT) and magnetic resonance images (MRI) of such patients for
sinusitis. PATIENTS AND METHODS: CT and MRI of the nasal sinuses were
retrospectively analysed in 71 HIV-positive patients. RESULTS: Sinusitis was
diagnosed in 49 of the 71 patients by conventional radiology (38), CT (13) and/or
MRI. In patients with sinusitis, contrary to those without it, there was a
significant correlation between progression of the HIV infection, as measured by
reduction in CD4 count, and an increased number of symptoms (r = -0.297; p <
0.05). The latter also correlated significantly with the frequency of concomitant
sinusitis (r = 0.336, p < 0.05). The radiological findings correlated more
closely with the CD4 count when tomography was used. The correlation coefficient
for the number of patients with concomitant sinus disease rose from r = -0.305 to
r = -0.459 and for the degree of severity from r = -0.324 to r = -0.484 (p <
0.05). Severity of sinus disease was clearly more marked among HIV-positive than
HIV-negative patients. CONCLUSION: The severity of sinusitis in HIV-positive
patients correlated directly with the level of the CD4 count. In these patients
tomographic methods are preferable to conventional radiology.
PMID- 10686956
TI - [Bougie endosonography in the preoperative diagnosis of stenosing esophageal
carcinomas].
AB - BACKGROUND AND OBJECTIVE: Nowadays ultrasonic endoscopy is accepted as the most
accurate method in the preoperative TNM staging of oesophageal tumour. At the
time a diagnosis of oesophageal is made, 25-62% of patients have marked
oesophageal stricture due to an advanced stage of the tumour. As a result, it is
often impossible to pass a conventional endoscope and the examination is
incomplete or a dilator has to be introduced at high risk of perforation or other
complications. An ultrasonic oesophagoprobe (Olympus MH 908) with a diameter of
7.9 mm, its tip acting as a dilator has been developed so that even in high-grade
oesophageal stricture a complete and low-risk investigation can be undertaken.
The value of this instrument has been compared prospectively with that of a
standard ultrasonic endoscope in patients with oesophageal stricture due to
carcinoma and in relation to the postoperative histology. PATIENTS AND METHODS:
Between May 1996 and February 1997, 62 patients (55 men, 7 women; average age
55.8 [41-82] years) with suspected or histologically confirmed oesophageal
carcinoma were examined with the standard ultrasonic endoscope and the new
oesophagoprobe. The two independent results were related to the postoperative
histology. RESULTS: It was possible to compare the endoscopic results with the
postoperative histology in 47 patients. In 55.8% it was not possible to pass the
stricture with the standard ultrasonic endoscope (SE) so that an accuracy of only
41% was obtained in the T stage and 56.4% in the N stage. But with the
oesophagoprobe (OP) an accuracy of 74.5% in the T stage and of 63% in the N stage
were achieved. The difference in the findings between the two instruments was
highly significant (p < 0.001) in those patients in whom the SE could not be
passed through the stricture. For the T stage the accuracy was 14.3% vs. 76.2%
(SE vs. OP); in the N stage it was 38.1% and 57.2%, respectively. When both
instruments could be passed the results were comparable. CONCLUSIONS: Examination
with the ultrasonic oesophagoprobe is a reliable and accurate method free of
complications for the preoperative assessment of oesophageal carcinoma with
stricture.
PMID- 10686957
TI - [Retroperitoneal desmoid tumor with kidney failure in familial adenomatous
polyposis].
AB - HISTORY AND FINDINGS: A 39-year-old man was hospitalized because of continually
rising urinary creatinine and blood urea nitrogen concentration. He was known to
have familial adenomatous polyposis (FAP), first diagnosed 18 years previously
and re-Physical examination was unremarkable except for pain on percussion over
both kidney regions. There was a well-healed laparotomy scar. INVESTIGATIONS:
Ultrasound revealed chronic bilateral obstructive renal disease, grade II-III,
and computed tomography showed a conglomerate retroperitoneal tumour with
obstruction of both ureters at the level of the lower pelvis. This tumour had
first been noted first 3 years after the colectomy when the patient complained of
abdominal pain. It had been identified histologically as a nonresectable
retroperitoneal desmoid tumour. TREATMENT AND COURSE: An external fistula was
made, relieving the renal retention. To suppress growth of the desmoid tumour
Sulindac, a nonsteroid anti-inflammatory drug, was administered. Genetic
molecular analysis revealed a germ line defect in codon 1690 of the APC gene. It
is intended to examine other members of the family for the presence of this
defect. CONCLUSION: Desmoid tumours are more common in persons with FAP and are
among the most frequent extracolic causes of their death. Treatment options are
critically analysed.
PMID- 10686958
TI - [Alveolar echinococcosis: therapy].
PMID- 10686959
TI - [Peripartal cardiomyopathy--its pathophysiology, diagnosis and current therapy].
PMID- 10686960
TI - [With chemistry against syphilis--the beginnings of chemotherapy around Paul
Ehrlich and the DMW. Deutsche Medizinische Wochenschrift].
PMID- 10686961
TI - [Procalcitonin in pediatric emergencies: comparison with C-reactive protein,
interleukin-6 and interferon alpha in the differentiation between bacterial and
viral infections].
AB - OBJECTIVE: Procalcitonin concentration increases in bacterial infections but
remains low in viral infections and inflammatory diseases. The change is rapid
and the molecule is stable making it a potentially useful marker for
distinguishing between bacterial and viral infections. PATIENTS AND METHODS:
Procalcitonin (PCT) was determined with an immunoluminometric assay on plasma
collected at admission in 436 infants and children hospitalized for bacterial or
viral infection. It was compared with C reactive protein, interleukin-6 and
interferon-alpha measured on the same sample. RESULTS: PCT was 41.3 +/- 77.4
micrograms/l in children with septicemia or bacterial meningitis (n = 53), 0.39
+/- 0.57 microgram/l in children with viral infection (n = 274) and 3.9 +/- 5.9
micrograms/l in children with a localized bacterial infection who had a negative
blood culture (n = 109). PCT was > 1 microgram/l in 126 children with a localized
or systemic bacterial infection (sensitivity 78%). PCT was < 1 microgram/l in 258
children with a viral infection (specificity 94%). For differenciation between
viral and bacterial infections, CRP value > or = 20 mg/l, IL-6 > 100 pg/ml and
interferon-alpha > 0 Ul/ml have 85, 48 and 76% sensitivity and 73, 85 and 92%
specificity respectively. CONCLUSIONS: In this study, a PCT value of 1
microgram/l or greater had better specificity, sensitivity and predictive value
than CRP, IL-6 and interferon-alpha in children for distinguishing between viral
and bacterial infections. PCT may be useful in pediatric emergency room for
making decision about antibiotic treatments.
PMID- 10686962
TI - [Leukemia and pre-leukemic conditions occurring after treatment of breast
cancer].
AB - OBJECTIVE: The purpose of this study was to determine the clinical and prognostic
features of leukemias and preleukemic states, whatever the mode of development,
observed in patients after treatment of breast cancer. PATIENTS AND METHODS: A
retrospective multicentric analysis was made of 121 patients treated for breast
cancer and who later developed leukemia or a preleukemic state. Initially, 44
patients had undergone mastectomy, 72 had conservative surgery and 119 had
locoregional irradiation. At least one chemotherapy session was performed in 90
patients and 48 had received tamoxifen. The risk of relapse of breast cancer was
high, moderate or low for 44, 46 and 24 patients respectively (data not available
for 7 patients). RESULTS: By class, the hematology diseases found were:
myelodysplasia (n = 9), refractory anemia with blast excess (n = 7), acute
lymphoblastic leukemia (n = 6), acute myoblastic leukemia (n = 93 including a
majority of type 2 and type 4). For acute myeloblastic leukemia, mean delay to
onset was 65 and 37 months respectively without and after chemotherapy. The
prognosis of these cases of leukemia and preleukemic states was poor with an
overall death rate of 86%. CONCLUSION: In light of the recent development of
indications for adjuvant chemotherapy even for subgroups of patients at moderate
risk, it is important to more precisely assess the absolute benefit in terms of
survival compared with the risk of severe complications, particular secondary
leukemia. In the future, a systematic registry and a case-control study are
required.
PMID- 10686963
TI - [Severe gastrointestinal hemorrhage secondary to diffuse angiodysplasia: efficacy
of estrogen-progesterone treatment].
AB - BACKGROUND: Vascular abnormalities are being reported with increasing frequency
as a cause of major lower gastrointestinal hemorrhage in the elderly. They are
occasionally very difficult to treat by conventional means. CASE REPORT: A 66
year-old white man with a history of type 2 diabetes mellitus, coronary artery
disease, congestive heart failure, severe peripheral arterial occlusion disease
and chronic renal insufficiency presented for five years recurrent major bleeding
due to gastrointestinal angiodysplasia, requiring repeated transfusions. He was
treated with efficacy using ethinyl-estradiol (30 micrograms) and norethisterone
acetate (1 mg) given orally once daily. After six months of treatment,
transfusion requirements fell to 0 unit and the patient's hemoglobin was stable
at 13 g/dl. Attempts to stop hormone therapy (by the patient himself, without
complaint of side effects) led to a fall in hemoglobin. CONCLUSION: Hormonal
therapy should be considered when multiple degenerative mucosal vascular bleeding
lesions are beyond the reach of therapeutic endoscopy leading to high transfusion
needs and when surgical risk is unacceptably high.
PMID- 10686964
TI - [Glucose-6-phosphate dehydrogenase deficiency and hemoglobinuric biliary fever
after taking mefloquine].
PMID- 10686965
TI - [Wide QRS: a criterion of imminent severity of beta blockader poisoning].
PMID- 10686966
TI - [Primary antiphospholipid syndrome disclosed by acute abdominal pain].
PMID- 10686967
TI - [The RALES study].
PMID- 10686968
TI - [HIV infection in Africa. Clinical and therapeutical research].
AB - A MAJOR HEALTH PROBLEM: Human Immunodeficiency Virus (HIV) infection is a major
public health problem in sub-Saharan Africa and the care of HIV-infected patients
is limited by the lack of resources. Clinical research can play a major role to
assess the benefit of preventive and/or curative measures adapted to the context
of these countries. To illustrate advances and gaps in HIV/AIDS clinical research
in Africa, we explored three issues relevant to this research: opportunistic
infections in adults, mother-to-child transmission of HIV and the ethical
questions. EPIDEMIOLOGY: Epidemiological African studies have shown: the
omnipresence of tuberculosis, first cause of death among HIV+ patients; the
frequency of bacterial infections, first cause of serious morbidity and second
cause of death; the high frequency of toxoplasmosis, cryptococcal meningitis,
isosporiasis, cryptosporidiasis, and other infectious syndromes of unknown
etiology. More research efforts need to be done for improving tuberculosis
diagnosis, compliance to treatment (evaluation of Directed Observed Therapy),
resistance to treatment and primary chemoprophylaxis which has shown clear short
term benefit but median term interest remains to be demonstrated.
Chemoprophylaxis of opportunistic infections other than tuberculosis needs also
to be evaluated: cotrimoxazole reduces the short term mortality of HIV+ patients
with tuberculosis and the early serious morbidity of HIV+ patients without
tuberculosis. TRANSMISSION: Mother-to-child transmission of HIV can occur during
pregnancy, during delivery and the postnatal period by breastfeeding, a common
practice in Africa. The overall risk of vertical transmission is estimated to be
30% but the attributable part of breastfeeding needs to be further explored.
Beyond the prevention of sexual transmission of HIV among childbearing women and
family planning for HIV+ women, interventions aimed to reduce mother-to-child
transmission depend on the availability or not of a proposing and realising an
HIV counselling and testing: antiretroviral treatments and/or breastfeeding
alternatives which reduce efficaciously transmission require HIV testing, while
vaginal disinfection and vitamin supplementation whom efficacy needs to be
demonstrated do not. PREVENTION: Prevention of mother-to-child transmission and
care of HIV+ adults in the area of opportunistic infections are feasible in
Africa with an acceptable cost. This requires first to train and inform health
care providers and the populations. Lots of uncertainties in these areas are
likely to be alleviated by reinforcing clinical and therapeutic research of good
quality including the questions of antiretroviral treatment. Ethical issues
raised by the design and conduct of clinical research in Africa need a positive
thinking to face the HIV African pandemic.
PMID- 10686969
TI - [The 39th ICAAC (San Francisco, September 1999). HIV infection in clinical
practice].
PMID- 10686970
TI - [Manic-depressive conditions in adolescents. Epidemiological and clinical
aspects].
AB - EPIDEMIOLOGY CONTEXT: The prevalence of maniac depressive disorders is similar in
adolescents and adults, i.e. about 1% with a 1:1 sex-ratio. Risk is higher in
families with a diseased member and early episodes of mood disorders are probably
correlated with the genotypic severity or the presence of a unique susceptibility
gene. HIGHLY VARIABLE CLINICAL SIGNS: Until recent years, the highly variable
clinical expression with rapid changes in mood, bipolar states, variable somatic,
behavioral or addictive symptomatology, cognition disorders, and disturbed
ideation or hallucinations, probably contributed to our poor understanding of
juvenile forms of the disease. EARLY MANAGEMENT: Early diagnosis and psychiatric
care is crucial due to the short-, mid- and long-term risk of unfavorable or even
fatal consequences. Indeed, while still in the process of structuralization, the
predisposed personality is particularly reactive to positive or negative events.
It is most difficult to achieve flexibility once a restrictive organization of
the personality has been installed. In addition, these families often have a
painful past and lack sufficient capacity to successfully deal with the stress of
emotions and conflicts occurring in the future adult during the self
identification and independence-seeking processes. This familial situation points
out the importance of implicating the family and close friends in the treatment
strategy as a complement to drug therapy and psychotherapy proposed to the
adolescent.
PMID- 10686971
TI - [Manic-depressive disorders in adolescence. Mood disorders and psychoses in
adolescence].
AB - DISEASE ONSET: In adolescents, the different aspects of mood disorders and
psychoses are closely related. The first episode of what will become
schizophrenia is often suggestive of a mood disorder. The inverse is also true.
Frequently, a psychotic state is the inaugural manifestation of a mood disorder.
SIGNS AND SYMPTOMS: The depressive manifestations observed in adolescents are
very similar to negative psychotic symptoms. More so than in adults, the thymic
disorder is expressed as severe episodes of psychosis. It would appear that in
this case, the psychotic elements are related to the intensity of the thymic
disorder. DIAGNOSTIC ERRORS: Misdiagnosis is probably related to the fact that
mood is not sufficiently taken into account in acute psychotic states. The risk
inherent in "over"-diagnosis of schizophrenic disorders is related to the
therapeutic implications: prescriptions of neuroleptics can hinder the psychic
work involved in the structuralization process going on in the adolescent.
PMID- 10686972
TI - [Manic-depressive disorders in adolescence. Psychoanalytic point of view].
AB - CLINICAL OBSERVATIONS: Melancholy and maniac disorders do not take on their
typical clinical form until adolescence, at the very time the psychic maturation
and identification processes are structuring the "definitive" personality. These
processes enable the subject to acquire his/her psychic independence of the
primary objects, particularly the primary maternal object and secondarily the
parent object. THE MELANCHOLIC OBJECT: In so-called melancholic personalities,
the identification with a primary maternal object was not totally successful
during infancy and had to follow a narcissistic mode. When during adolescence the
subject is faced with symbolic or real separations (independence) his/her
identification object has to split with loss of the invested object, leading to
melancholy (or its negative pseudo-triumphant variant: maniac disorder).
IMPORTANT PROCESSES IN ADOLESCENCE: Adolescence is an exceptional, highly
sensitive period when identifications acquired during infancy undergo
reorganization. It is a time when defective identification can be reelaborated,
favoring structuralization of a "normal" or "pathological" (here maniac
depressive) personality depending on the quality of the "identificatory",
therapeutic (psychotherapy), or daily life events.
PMID- 10686973
TI - [Manic-depressive disorders in adolescence. Lithium treatment].
AB - FIRST INTENTION PREVENTION: Lithium is the first intention preventive treatment
for bipolar disorders. It the most effective choice in this indication and
provides the most benefit for the patient, particularly the young patient still
in the process of maturation. SURVEILLANCE: Serum lithium must be monitored
regularly. It is important for the clinician to be aware of different factors
which can modify serum levels, including disease states or iatrogenic effects
related to co-prescriptions. PATIENT INFORMATION: Long-term compliance and
surveillance, and thus treatment efficacy, depend greatly on the quality of the
information provided to the patient and his/her family.
PMID- 10686974
TI - Inflammatory cytokines and cell response in surgery.
AB - The systemic inflammatory response as mediated by the cytokine network is
undoubtedly complex. While inflammatory cytokines are indispensable in wound
healing and the restoration of homeostasis, it is often the excessive activity of
either proinflammatory or anti-inflammatory cytokines that causes injury to the
host or renders the host immunocompromised, respectively. Central to the
functional biology of cytokines in surgical injury and infections are the
responses of immune cells to such insults. It is clear that immunocytes are the
source of cytokine production, and these products possess important autocrine, as
well as systemic activities. The ability to alter immunocyte function through
extracellular hormonal influences or by manipulating intracellular signaling
mechanisms are potential strategies for regulating the inflammatory cytokine
response during injury.
PMID- 10686975
TI - Invited commentary: are the staging systems for lymphatic spread important in
gastric cancer?
PMID- 10686976
TI - Superiority of a new UICC-TNM staging system for gastric carcinoma.
AB - BACKGROUND: The definition of the degree of lymph node metastasis (n
classification) for gastric cancer differs greatly in the new Union
Internationale Contre le Cancer--TNM classification (5th edition) and the
Japanese gastric cancer classification (JGC). The feasibility of the new TNM
classification is evaluated in comparison with the JGC. METHODS: At Chiba
University, 940 patients who underwent a gastrectomy were retrospectively
classified into appropriate stages with both the TNM and JGC systems, and the
survival curves of the respective stages were also compared. RESULTS: Patients
with 1 to 6 metastatic nodes (TNM-pN1) showed similar survival rates whether the
metastases were limited to the perigastric area (JGC-n1) or reached distant areas
(JGC-n2). The patients with node metastasis that was limited to the perigastric
area (JGC-n1) had significantly different survival rates, depending on the number
of metastatic nodes (TNM-pN1 or pN2, P = .022). A similar phenomenon was also
observed in patients with TNM-N2 and JGC-n2. A multivariate analysis indicated
the TNM N-classification, rather than the JGC n-classification, as an independent
prognostic factor. CONCLUSIONS: The new TNM classification appears to be a better
prognostic indicator than the JGC system for patients with gastric carcinoma.
PMID- 10686977
TI - Gangrenous and perforated appendicitis: a meta-analytic study of 2532 patients
indicates that the incision should be closed primarily.
AB - BACKGROUND: Surgical incisions after appendectomy for complicated (gangrenous or
perforated) acute appendicitis are often managed with delayed closure (DC) rather
than primary closure (PC). This study synthesizes the results of other studies in
the surgical literature and supports the routine use of PC. METHODS: Studies
dealing with complicated appendicitis were reviewed to assess the results of PC
in comparison with DC. The rate of incision (wound) infection in groups of
patients managed by PC and DC were compared with the use of a statistical
technique that defined the probability of expected results by incorporating data
derived from all of the various study groups. RESULTS: Of the 2532 patients who
had been treated for complicated appendicitis and who were assessed, 1724
patients underwent PC and 808 patients underwent DC. The rate of incision
infection was 4.7% and 4.6% in the PC and DC groups, respectively. With a 95%
confidence interval, there was no demonstrable difference between the 2 types of
operative site management (P < .01). CONCLUSIONS: PC of the skin and subcutaneous
tissue after appendectomy for gangrenous or perforated appendicitis, combined
with the use of antibiotic therapy in the perioperative period, is not associated
with an increased risk of incision infection when compared with DC.
PMID- 10686978
TI - Neutrophil-derived serine proteinases enhance membrane type-1 matrix
metalloproteinase-dependent tumor cell invasion.
AB - BACKGROUND: Matrix metalloproteinase-2 degrades a variety of basement membrane
components and is essential for tumor invasion. We have previously reported that
membrane type-1 matrix metalloproteinase (MT1-MMP) cooperates with neutrophil
derived serine proteinases (NDPs; elastase, cathepsin G, protease-3) to activate
matrix metalloproteinase-2. We therefore hypothesized that NDPs enhance tumor
cell invasion. METHODS: Clones of human HT1080 fibrosarcoma cells transfected
with MT1-MMP sense (HT-SE) or antisense CDNA (HT-AS) were used. These cells
express either high (HT-SE) or extremely low levels (HT-AS) of MT1-MMP relative
to nontransfected HT1080 cells (HT-WT). The cells were incubated in the presence
or absence of purified NDP, with or without alpha 1-antitrypsin or the MMP
inhibitor batimastat. Cell invasion was measured with the use of Boyden chambers
with polycarbonate membranes coated with a reconstituted extracellular matrix.
RESULTS: Under control conditions HT-WT and HT-SE cells were 4-fold more invasive
than HT-AS cells. The addition of NDP increased HT-WT and HT-SE cell invasion 60%
to 100% but had no effect on HT-AS cells. alpha 1-antitrypsin or batimastat did
not decrease the baseline invasiveness of HT-WT and HT-SE cells; however, they
abrogated the stimulatory effect of NDP. CONCLUSIONS: HT1080 cell invasion
depends on MT1-MMP expression. MT1-MMP overexpression does not increase
invasiveness by itself. NDPs increase invasion by MT1-MMP expressing cells by
activating matrix metalloproteinase-2.
PMID- 10686979
TI - Vascular smooth muscle mechanics in isolated perfused segments of carotid
arteries.
AB - BACKGROUND: We hypothesized that smooth muscle contraction and relaxation
responses in a muscle bath (isometric tension) would be different than responses
of intact vessels (isotonic tension). METHODS: Bovine carotid artery contractile
responses to the catecholamine, norepinephrine, and smooth muscle relaxant, 3
isobutyl-1-methylxanthine, were examined in strips of vessels in a muscle bath
and in intact whole vessels in an isolated perfused whole-vessel perfusion
apparatus. RESULTS: The maximal tension in the muscle bath depended on the length
of the strip. The responses of whole vessels to increasing pressure was
curvilinear. The maximal decrease in vessel diameter in intact vessels in
response to the catecholamine and norepinephrine occurred at low intraluminal
pressures. The dose-response curve to norepinephrine was shifted to the left in
intact vessels compared with strips of vessels in the muscle bath, which suggests
that whole vessels were more sensitive to norepinephrine. The maximal increase in
diameter to increasing intraluminal pressure occurred in the presence of the
phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine, which suggests that
there was significant intrinsic tone in the vascular smooth muscle. CONCLUSIONS:
These results suggest that there are differences in the contractile properties of
the vascular smooth muscle that are related to the ex vivo system used to examine
smooth muscle responses. Responses obtained in isolated perfused whole vessels
may more closely approximate in vivo responses.
PMID- 10686980
TI - Right trisegment portal vein embolization for biliary tract carcinoma: technique
and clinical utility.
AB - BACKGROUND: Right portal vein embolization has become popular in preparation for
right hepatic lobectomy. However, right trisegment portal vein embolization
(R3PE) is not well established. METHODS: We performed R3PE in 15 patients with
biliary tract carcinoma and 1 patient with primary sclerosing cholangitis. We
used 2 types of 5.5 F triple-lumen balloon catheters to embolize portal branches
of the right trisegment (the left medial, the right anterior, and the right
posterior segments). RESULTS: R3PE was successful in all patients without any
complications. The calculated volume of the right lobe significantly (P < .01)
decreased from 650 +/- 161 cm3 before embolization to 585 +/- 143 cm3 after
embolization; the volume of the left lateral segment significantly (P < .0005)
increased from 240 +/- 58 cm3 to 361 +/- 66 cm3. The volume of the left medial
segment was unchanged. The volume gain of the left lateral segment was larger in
patients with R3PE than in those patients (n = 41) with right portal vein
embolization (122 +/- 39 cm3 vs 66 +/- 35 cm3; P < .0001). Two of the 16 patients
underwent only laparotomy because of peritoneal dissemination, and the remaining
14 patients underwent right hepatic trisegmentectomy with caudate lobectomy. In
addition, portal vein resection was also performed in 5 patients, and
pancreatoduodenectomy and right hemicolectomy was performed in 3 patients. One
patient died of posthepatectomy liver failure 87 days after surgery, a mortality
rate of 7.1% (1/14 patients). CONCLUSIONS: R3PE is more useful than standard
right portal vein embolization in preparation for right hepatic trisegmentectomy
and has the potential to increase the safety of this high-risk surgery for
patients with biliary tract carcinoma.
PMID- 10686981
TI - Adenosine prevents activation of transcription factor NF-kappa B and enhances
activator protein-1 binding activity in ischemic rat heart.
AB - BACKGROUND: Adenosine prevents myocardial TNF-alpha production induced by
ischemia/reperfusion, but the mechanisms are poorly understood. Transcription
factors NF-kappa B and AP-1 have been implicated in the regulation of a variety
of inducible gene expressions in response to oxidative stress and cellular
defense. The effects of adenosine on NF-kappa B and AP-1 activation have not been
clearly defined. This study demonstrated differential effects of adenosine on NF
kappa B and AP-1 nuclear binding activity in ischemic myocardium. METHODS:
Isolated working rat hearts were subjected to 0, 1, 2, 3, 4, 5, 7.5, 10, 15, and
30 minutes of ischemia, with 4 to 6 hearts for each time point with and without
adenosine (100 mumol/L). NF-kappa B and AP-1 binding activity in the nucleus were
analyzed by electrophoretic mobility shift assay (EMSA). I kappa B alpha levels
in the cytoplasm were measured by Western blot analysis. TNF-alpha mRNA levels
were determined by RT-PCR. RESULTS: NF-kappa B binding activity in the nucleus
significantly increased after 4 minutes of ischemia and remained to 30 minutes.
The levels of I kappa B alpha protein in the cytoplasm markedly decreased after
4, 5, 7.5, and 10 minutes of ischemia. TNF-alpha mRNA levels peaked after 10
minutes of ischemia. AP-1 DNA binding activity was induced and persisted during
all ischemic periods. Adenosine significantly inhibited NK-kappa B binding
activity in the nucleus, markedly prevented the loss of I kappa B alpha proteins
from the cytoplasm, and concomitantly down-regulated TNF-alpha mRNA expression,
but enhanced AP-1 binding activity in the nucleus of ischemic myocardium.
CONCLUSIONS: Adenosine modulation of NF-kappa B activation may be the cellular
molecular mechanism of down-regulation of TNF-alpha mRNA expression. The
cardioprotective properties of adenosine may be involved in the differential
modulation of NF-kappa B and AP-1 activation during myocardial ischemia.
PMID- 10686982
TI - Myoelectric and motor activity after proctocolectomy and ileal pouch-anal
anastomosis in dogs.
AB - BACKGROUND: The aim of this study was to investigate the motor function of the
ileoanal pouch and to evaluate its coordination with proximal small-intestine
motility. METHODS: Proctocolectomy and ileal J pouch-anal anastomosis were
performed in 12 dogs. Motility was recorded by serosal electrodes and strain
gauge transducers. RESULTS: Transmission of the migrating motor complex (MMC) on
the pouch appeared in only 37 of 109 measurements. On the ascending limb there
was a constant irregular activity with no MMC detectable. Motility pattern of the
pouch did not change postprandially. Spontaneous defecation always appeared
independently from MMC transmission without an increase of electrical or
mechanical activity or endoluminal pouch pressure. CONCLUSIONS: Ileal pouch
motility is independent from motility patterns of the proximal intestine. Its
random contractile activity might provide storage function and make the pouch act
as a functional reservoir. Intrinsic pouch motility is not responsible for pouch
evacuation under physiologic conditions.
PMID- 10686983
TI - Conservative surgical treatment of diffuse peritonitis.
AB - BACKGROUND: Peritonitis is, even today, a significant source of death and
complications. The objective of this study was to determine the morbidity and
mortality rates, the incidence of reoperations, and the need for additional
treatment strategies (on demand) in patients with diffuse peritonitis. METHODS:
Prospective analysis including all patients (n = 258) with diffuse peritonitis
admitted to our surgical service between November 1993 and April 1998 who
underwent a uniform surgical treatment concept of peritonitis including early
intervention, source control, and extensive intraoperative lavage. RESULTS: The
258 patients with diffuse peritonitis averaged a mean Mannheim Peritonitis Index
of 27.1 points (range, 11-43 points). Source control at the initial operation was
possible in 230 of the patients (89%), of those, 21 patients (9%) needed
reintervention. In 28 patients (11%), source control was not possible at the
initial operation. Twenty of these patients (71%) had to undergo additional
treatment strategies (on demand) such as continuous lavage and/or laparostomy.
Overall 228 of the 258 patients (88%) needed just 1 initial surgical
intervention. The overall morbidity rate was 41%; the rate of reoperation was
12%, and the hospital mortality rate was 14%. CONCLUSIONS: A conservative
surgical treatment concept supplemented with "extensive" intraoperative lavage
reduces the reoperation rate compared with other treatment standards of
peritonitis and achieves a low mortality rate in patients with diffuse
peritonitis.
PMID- 10686984
TI - Usefulness of autologous blood transfusion for avoiding allogenic transfusion and
infectious complications after esophageal cancer resection.
AB - BACKGROUND: A retrospective investigation was conducted to determine whether
autologous blood collection could reduce allogenic transfusion after resection of
esophageal cancer and whether allogenic transfusion influenced postoperative
infection. METHODS: Patients (n = 100) who met the criteria for hemoglobin, age,
body weight, and serum protein donated 800 mL of autologous blood from May 1994
to December 1997. The control group (n = 248) was selected from patients who met
the same criteria and did not donate autologous blood over the 10 years before
the start of autologous blood collection. RESULTS: Only three patients (3%) from
the autologous group required allogenic transfusion versus 84 patients (33.7%)
from the control group. Sixteen of the 26 patients who received more than 4 units
of allogenic blood contracted postoperative infections compared with 25 of 165
patients who did not (P < .0001). Autologous blood transfusion significantly
increased the probability of avoiding allogenic transfusion (odds ratio, 27.58),
and allogenic transfusion was significantly related to postoperative infection
(odds ratio, 1.19), according to logistic regression analysis. CONCLUSIONS:
Autologous blood collection reduces the need for allogenic transfusion in
patients undergoing resection of esophageal cancer, and avoidance of allogenic
transfusion may reduce the risk of postoperative infection.
PMID- 10686985
TI - Multiple intrasplenic hepatocyte transplantations in the dalmatian dog.
AB - BACKGROUND: Hepatocyte transplantation is an attractive potential treatment for
liver-based inborn errors of metabolism and for fulminant hepatic failure.
Dalmatian dogs have a metabolic error that results in hyperuricosuria. This
report focuses on the effect of multiple, sequential intrasplenic transplants of
fresh and cryopreserved hepatocytes in dalmatians. METHODS: Dalmatians underwent
intrasplenic hepatocyte transplantation with hepatocytes taken from healthy
mongrels. Dalmatian urinary uric acid excretion was measured preoperatively, and
this served as the control value. Three hepatocyte transplantations were
performed at 30-day intervals--the first with freshly isolated cells, and both
the second and the third with cryopreserved hepatocytes from the same donor.
Urinary uric acid excretion was measured postoperatively twice per week. RESULTS:
The urinary uric acid excretion decreased an average of 54% after the first
hepatocyte transplantation. The effect was transient and lasted an average of 22
days (range, 19-50 days). Subsequent intrasplenic hepatocyte transplantation with
cryopreserved hepatocytes resulted in similar decreases in urinary uric acid
excretion. Each transplant resulted in a significant decrease in urinary uric
acid excretion when compared with baseline values (P = < .001). CONCLUSIONS:
Sequential intrasplenic hepatocyte transplantation is feasible in this model.
This method provided a significant, but transient, correction in urinary uric
acid excretion that was similar with either fresh or cryopreserved hepatocytes. A
substantial biologic effect provided by cryopreserved hepatocytes has important
implications in clinical hepatocyte transplantation.
PMID- 10686986
TI - Esophagogastric junction pressure topography after fundoplication.
AB - OBJECTIVES: This study compared the pressure topography after laparoscopic Nissen
fundoplication to that of normal subjects and patients with hiatal hernia and
reflux disease. METHODS: Seven patients with fundoplication, 7 normal subjects
and 7 patients with hiatal hernia, were studied. The squamocolumnar junction and
intragastric margin of the esophagogastric junction (EGJ) were marked with metal
clips. Axial and radial characteristics of EGJ pressure were mapped relative to
the hernia and clipped during concurrent fluoroscopy and manometry. Responses to
inspiration and abdominal compression were also analyzed. RESULTS: Fundoplication
modifies the EGJ by restoration of the hiatal component of EGJ pressure and
elongation of the subdiaphragmatic component. Maximal EGJ pressure after
fundoplication is mainly dependent on the extrinsic effect of the hiatal canal
that compresses the esophagus; the resultant length of the EGJ reflects the
length of the fundic wrap. Integrity of the EGJ after fundoplication is
independent of the intrinsic lower esophageal sphincter itself. CONCLUSIONS:
Fundoplication alters the pressure topography of the EGJ by reducing the hiatal
hernia, tightening the hiatal orifice, and constructing a subdiaphragmatic wrap
of variable length. Each effect depends on different technical aspects of the
surgery with the potential of substantial variability in the resultant pressure
topography.
PMID- 10686987
TI - Neutrophils express tissue factor in a monkey model of sepsis.
AB - BACKGROUND: Although tissue factor (TF) is involved in hemostasis,
thrombogenesis, inflammation, and cellular immune response, its source in sepsis
remains controversial. Recently, we found that, in addition to monocytes and
endothelial cells, neutrophils may express TF in a rabbit model. The purpose of
this study was to determine whether neutrophils could be a source of TF in a
monkey model of sepsis. METHODS: TF messenger RNA (mRNA) and protein in
neutrophils were assayed by in situ hybridization and immunohistochemistry in
tissues obtained from monkeys after injection of lipopolysaccharide (LPS) (n = 3)
and after injection of saline as a control (n = 2). Coagulation parameters were
measured before and at 1.5 and 3 hours after injections. RESULTS: In LPS-treated
monkeys, TF mRNA and protein were induced not only in monocytes and endothelial
cells, but also in neutrophils accumulating in the liver 3 hours after LPS
injection. Thrombin-antithrombin III complex and fibrin degradation products D
dimer levels were significantly increased at 3 and 1.5 hours after LPS injection
compared with controls. CONCLUSIONS: Neutrophils are a source of TF and are
implicated in direct activation of the coagulation cascade in the early phases of
sepsis in the monkey. These results give important information for the treatment
of sepsis.
PMID- 10686988
TI - A prospective comparison of systemic-bladder versus portal-enteric drainage in
vascularized pancreas transplantation.
AB - BACKGROUND: Most pancreas transplants are performed with systemic venous delivery
of insulin and bladder drainage of the exocrine secretions (systemic-bladder [S
B]). To develop a more physiologic procedure, we performed pancreas
transplantations with portal venous delivery of insulin and enteric drainage of
the exocrine secretions (portal-enteric [P-E]). METHODS: During an 11-month
period, we prospectively alternated 32 consecutive pancreas transplant recipients
to either S-B (n = 16) or P-E (n = 16) drainage with standardized
immunosuppression. RESULTS: Patient, kidney, and pancreas graft survival rates
after simultaneous kidney-pancreas transplantation were 91% S-B versus 92% P-E,
91% S-B versus 92% P-E, and 82% S-B versus 92% P-E, respectively. Pancreas graft
survival rates after solitary pancreas transplantation were 80% S-B versus 75% P
E. There were no graft losses either to immunologic or infectious complications
in either group, but the incidence of acute rejection was slightly higher in the
S-B group (44% S-B vs 31% P-E, P = NS). The cost and length of the initial
hospital stay were similar between groups. The incidence of operative
complications, major infections, and cytomegalovirus infections were likewise
comparable. However, the S-B group was characterized by a slight increase in the
number of readmissions, urinary tract infections, and urologic complications.
Furthermore, metabolic acidosis and dehydration were more common in the S-B
group. CONCLUSIONS: Pancreas transplantation with P-E drainage can be performed
with short-term results comparable to those of transplantation with S-B drainage.
PMID- 10686989
TI - A surgeon is an amalgam of many elements.
PMID- 10686990
TI - Successful transplantation in a patient with ruptured large hepatocellular
carcinoma with diaphragmatic invasion.
PMID- 10686991
TI - The use of intra-aortic counterpulsation balloon for the treatment of cerebral
vasospasm and edema.
PMID- 10686992
TI - Surgical management of inflammatory abdominal aortic aneurysm associated with
occult aortocaval fistula.
PMID- 10686993
TI - Malignant colorectal cell spread during no-touch cancer surgery.
PMID- 10686994
TI - Misclassification of hospital procedure volume in surgical outcomes studies.
PMID- 10686995
TI - USDA to help pets in distress.
PMID- 10686996
TI - Treatment advances reported at equine meeting.
PMID- 10686997
TI - Meat irradiation gets green light, approval process streamlined.
PMID- 10686998
TI - Concerning wild canids and wolf hybrids.
PMID- 10686999
TI - Requests for cooperation between private practitioners and shelter veterinarians.
PMID- 10687000
TI - In support of veterinary pathologists.
PMID- 10687001
TI - What is your diagnosis? Tracheal collapse at the level of the sixth cervical
vertebra.
PMID- 10687002
TI - Theriogenology question of the month. Specific aversion to handling for semen
collection and to personal approaching the genital area.
PMID- 10687003
TI - Genetic counseling for cat and dog owners and breeders--managing the emotional
impact.
PMID- 10687004
TI - Results of a survey on educational and research programs in complementary and
alternative veterinary medicine at veterinary medical schools in the United
States.
AB - OBJECTIVE: To document educational and research programs in complementary and
alternative veterinary medicine (CAVM) at US veterinary schools and to develop
recommendations for additional curriculum development and research in these
modalities. DESIGN: Mail questionnaire. SAMPLE POPULATION: Deans, curriculum
committees, and interested faculty at US veterinary schools. PROCEDURES:
Questionnaires were mailed to personnel at all 27 US veterinary schools.
Nonrespondents received a follow-up letter and telephone contact. Information was
used to establish the current status of CAVM. RESULTS: Responses were received
for 41 of 120 (34%) questionnaires. Responses were received from 23 of 27
veterinary schools, but number of respondents varied at each institution (range,
1 to 4) and some surveys were not complete. Seven of 27 US veterinary schools had
an educational program in CAVM. Thirty-six (87%) respondents believed that
acupuncture, nutraceuticals, nutritional supplements, and physical therapy should
be included in the curriculum, 25 (61%) indicated that botanical (herbal)
medicine should be included, and 25 (61%) believed that chiropractic should be
included. Only 17 (44%) respondents believed that homeopathy should be included.
The majority of respondents believed that CAVM should be offered as elective
courses. Research in CAVM has been conducted at 6 responding schools.
CONCLUSIONS: Currently, few veterinary schools offer educational or research
programs in CAVM. Veterinary schools are aware of the interest in CAVM and
acknowledge a lack of educational and research programs in these areas. More
veterinary schools are in the process of developing educational and research
programs in various aspects of CAVM.
PMID- 10687005
TI - Types and doses of injectable medications given to periparturient sows.
AB - OBJECTIVE: To determine types and doses of injectable medications given to
periparturient sows and reasons for administering those medications, and to
compare medication practices among farms of different sizes. DESIGN: Survey.
SAMPLE POPULATION: 301 farms; 231,016 periparturient sows. PROCEDURE: A survey
was used to obtain information regarding medications given to sows during the
farrowing period. State and federal veterinary medical officers completed surveys
during their final interview with producers who had participated in the National
Animal Health Monitoring System's (NAHMS) Swine 95 study. Data were summarized
and treatment regimens compared among farms of different sizes. RESULTS: More
than a third of the sows received medications during the farrowing period. The
most common reasons for administering medications were routine preventive
treatment and treatment of dystocia, uterine discharge, and poor appetite. The
most commonly used medications for treatment of sick sows were oxytocin, procaine
penicillin G, and B vitamins. A high percentage of medications were either not
indicated for the specific condition or used at greater or less than the approved
dose. In general, treatment rates and medications used did not differ among farms
of different sizes. CONCLUSIONS AND CLINICAL RELEVANCE: Better treatment
protocols are needed to provide more appropriate treatment of sick sows.
PMID- 10687006
TI - Peliosis hepatis in a dog infected with Bartonella henselae.
AB - A 6-year-old spayed female Golden Retriever was examined because of generalized
weakness and abdominal distention. Abdominal ultrasonography revealed a large
quantity of peritoneal fluid. In addition, the liver appeared larger than normal
and contained multiple, small, nodular masses and cyst-like structures. Abdominal
exploratory surgery was performed, and 5 L of serosanguineous peritoneal fluid
was removed. Gross lesions were not found in the stomach, kidneys, intestines,
adrenal glands, or urinary bladder. There were diffuse cystic nodules in all
liver lobes. The dog did not recover from anesthesia. A diagnosis of peliosis
hepatis was made on the basis of gross and histologic appearance of the liver. A
polymerase chain reaction assay revealed Bartonella henselae DNA in liver
specimens. To our knowledge, this is the first report of molecular evidence of B
henselae infection in a dog with peliosis hepatis.
PMID- 10687007
TI - Epitheliotropic T-cell gastrointestinal tract lymphosarcoma with metastases to
lung and skeletal muscle in a cat.
AB - An Abyssinian cat examined because of hypoproteinemia and weight loss was found
to have epitheliotropic T-cell lymphosarcoma of the gastrointestinal tract.
Neoplastic lymphocytes infiltrated the epithelium and lamina propria of the
stomach, small intestine, and large intestine. Metastatic foci were found in the
lungs and the musculature of the right hind limb. Chemotherapy resulted in
transient shrinkage of the lung and limb masses; however, these masses grew to
approximately their original size within 2 weeks after initiation of treatment,
and the cat was euthanatized.
PMID- 10687008
TI - Clinical, radiographic, and pathologic features of bronchiectasis in cats: 12
cases (1987-1999).
AB - OBJECTIVE: To determine clinical, radiographic, and pathologic features of
bronchiectasis in cats. DESIGN: Retrospective study. ANIMALS: 12 cats with
histologic evidence of bronchiectasis. PROCEDURE: Information on signalment, body
weight, clinical signs of respiratory disease, concurrent diseases, method by
which lung tissue specimens were obtained (surgical biopsy or necropsy), and
histopathologic findings was obtained by reviewing medical records from January
1987 to June 1999 for cats with confirmation of bronchiectasis by histologic
examination. Available thoracic radiographs were reviewed by a board-certified
radiologist. RESULTS: Bronchiectasis was most commonly identified in older male
cats. Clinical signs referable to the lower portion of the respiratory tract were
detected in only 5 cats but, when evident, were usually chronic (duration > 1
year). Radiographic pattern of bronchiectasis was cylindrical in 4 cats, and in 1
of these cats, a saccular pattern was also identified. For most cats,
bronchiectasis was detected in a single lung lobe. Radiographic evidence of
bronchiectasis was not detected in 2 cats. Concurrent respiratory diseases
included chronic bronchitis and bronchiolitis, neoplasia, bronchopneumonia,
endogenous lipid pneumonia, and emphysema. CONCLUSIONS AND CLINICAL RELEVANCE:
Bronchiectasis appears to be an uncommon respiratory tract disorder that
predominantly affects older male cats. Thoracic radiography may not be sensitive
for the diagnosis of bronchiectasis in cats. Bronchiectasis in cats appears to be
a sequela of chronic inflammatory bronchopulmonary diseases, especially chronic
bronchitis, neoplasia, and bronchopneumonia.
PMID- 10687009
TI - Descriptive epidemiologic study of disease associated with influenza virus
infections during three epidemics in horses.
AB - OBJECTIVE: To describe 3 epidemics of respiratory tract disease caused by
influenza virus infections in a large population of horses. DESIGN: Cross
sectional and prospective longitudinal observational studies. ANIMALS: All horses
stabled at a Thoroughbred racetrack. PROCEDURES: During a 3-year period,
descriptive information was collected as horses arrived at the racetrack and
throughout race meetings. Routine observations and physical examinations were
used to classify horses' disease status. Cause of epidemics was established by
use of serologic testing and identification of influenza virus in nasal
secretions. RESULTS: An epidemic of respiratory tract disease caused by influenza
virus infections was identified during each year of the study. Attack rates of
infectious upper respiratory tract disease (IURD) ranged from 16 to 28%.
Incidence of disease caused by influenza virus infections during racing seasons
in the second and third years was 27 and 37 cases/1,000 horses/mo, respectively.
Physical distributions of stall locations revealed that affected horses were
stabled throughout the population; horses affected later in epidemics were often
clustered around horses affected earlier. Mucopurulent nasal discharge and
coughing were observed in 83 and 62% of horses with IURD, respectively. Median
duration of clinical disease was 11 days. Serologic testing was the most
sensitive method used to detect influenza virus infections; 76% of affected
horses seroconverted to influenza virus. CONCLUSIONS AND CLINICAL RELEVANCE:
Epidemics of IURD were observed annually in association with influenza virus
infections. Few precautions were taken to limit spread of infection. Preventing
or decreasing the likelihood of exposure and improving immunity in the population
could substantially decrease risk of disease in similar populations.
PMID- 10687010
TI - Risk factors for disease associated with influenza virus infections during three
epidemics in horses.
AB - OBJECTIVE: To identify risk factors associated with respiratory tract disease in
horses during 3 epidemics caused by influenza virus infections. DESIGN: Cross
sectional and prospective longitudinal observational studies. ANIMALS: 1,163
horses stabled at a Thoroughbred racetrack. PROCEDURES: Investigations were
conducted during a 3-year period. An epidemic of respiratory tract disease caused
by influenza virus infections was identified in each year. Routine observations
and physical examinations were used to classify horses' disease status. Data were
analyzed to identify factors associated with development of disease. RESULTS:
Results were quite similar among the epidemics. Concentrations of serum
antibodies against influenza virus and age were strongly associated with risk of
disease; young horses and those with low antibody concentrations had the highest
risk of disease. Calculation of population attributable fractions suggested that
respiratory tract disease would have been prevented in 25% of affected horses of
all horses had high serum antibody concentrations prior to exposure. However,
recent history of vaccination was not associated with reduction in disease risk.
Exercise ponies had greater risk of disease than racehorses, which was likely
attributable to frequent horse-to-horse contact. CONCLUSIONS AND CLINICAL
RELEVANCE: Particular attention should be paid to young horses, those with low
serum antibody concentrations, and horses that have frequent contact with other
horses when designing and implementing control programs for respiratory tract
disease caused by influenza virus infections. It appears that control programs
should not rely on the efficacy of commercial vaccines to substantially reduce
the risk of disease caused by influenza virus infections.
PMID- 10687011
TI - Squamous cell carcinoma of the urethral process in a horse with hemospermia and
self-mutilation behavior.
AB - A 14-year-old Arabian stallion was examined because of acute hemospermia. The
stallion was used in an artificial breeding program and had a 6-year history of
low-grade hemospermia and a 4-year history of self-mutilation behavior. During
previous examinations, minor irritation of the urethral process was identified as
the source of the bleeding. Physical examination revealed a mucosal ulceration in
the distal portion of the urethra. Histologic examination of a biopsy specimen
from this area revealed low-grade squamous cell carcinoma. The urethral process
was excised, and the hemospermia resolved. Frequency of self-mutilation behaviors
also decreased after surgery, suggesting that there may have been a link between
irritation of the urethral process and development of self-mutilation behavior.
PMID- 10687012
TI - Causes of poor performance of horses during training, racing, or showing: 348
cases (1992-1996).
AB - OBJECTIVE: To determine results for horses undergoing a high-speed treadmill
examination, including videoendoscopy of the pharynx and larynx before and during
exercise, echocardiography before and after exercise, and electrocardiography
before, during, and after exercise, because of poor performance. DESIGN:
Retrospective study. ANIMALS: 348 horses. RESULTS: A definitive diagnosis was
obtained for 256 (73.5%) horses. One hundred forty-eight horses had dynamic
obstruction of the airway during exercise, 33 had clinically important cardiac
arrhythmias alone, 22 had a combination of dynamic airway obstruction and
clinically important cardiac arrhythmias, 19 had poor cardiac fractional
shortening immediately after exercise, 10 had exertional rhabdomyolyis, 15 had
clinically apparent lameness, and 9 had other disorders. Thirty-nine of the
horses with dynamic obstruction of the airway during exercise had multiple airway
abnormalities. Fifty-three horses also had subclinical myopathy CONCLUSIONS AND
CLINICAL RELEVANCE: Results suggest that a complete evaluation, including a high
speed treadmill examination, should be conducted in horses with poor performance,
regardless or whether horses do or do not have a history of abnormal respiratory
noises and particularly if the horses have grade-II or -III left laryngeal
hemiplegia.
PMID- 10687013
TI - Evaluation of assays for determination of passive transfer status in neonatal
llamas and alpacas.
AB - OBJECTIVE: To evaluate several practice-adapted assays for determination of
passive transfer status in crias. ANIMALS: 24 llama and 9 alpaca crias. DESIGN:
Prospective study. PROCEDURE: Serum IgG concentration was measured by use of a
radial immunodiffusion assay when crias were 45 to 51 hours old. Results were
compared with serum gamma-glutamyltransferase (GGT) activity, serum total
protein, albumin, globulin, and total solids concentrations, and results of
commercially available and traditional sodium sulfite turbidity (SST) tests.
RESULTS: Mean (+/- SD) serum IgG concentration was 1,762 +/- 1,153 mg/dl. On the
basis of a threshold value of 1,000 mg of IgG/dl at 48 hours of age, 5 of 33
(15.15%) crias had failure of passive transfer. Serum total solids, protein, and
globulin concentrations were significantly associated with serum IgG
concentration, whereas serum GGT activity and serum albumin concentration were
not. Serum IgG concentrations were significantly different among crias with
negative, 2+, and 3+ scores on the traditional SST test. Serum IgG concentrations
were not significantly different between crias with negative and 100 mg/dl scores
or 100 and 300 mg/dl scores on the commercially available SST test. However, all
other comparisons between crias with different scores revealed significant
differences. Sensitivity and specificity ranged between 0 and 1, depending on the
test and endpoint selected. CONCLUSIONS AND CLINICAL RELEVANCE: The commercially
available SST test and determination of serum total protein and globulin
concentrations are suitable methods for assessing passive transfer status in
llama and alpaca crias.
PMID- 10687014
TI - Diagnosis and surgical repair of patellar luxations in a flock of sheep.
AB - Eleven sheep with a common ancestry were evaluated for clinical signs of hind
limb lameness. Physical examination revealed advanced forms of patellar luxation.
Radiography confirmed the diagnosis of patellar luxation; flexed dorsoproximal
dorsodistal radiographic views were obtained and revealed hypoplasia of the
femoral trochlea. Because of the advanced form of patellar luxation and trochlear
hypoplasia, surgical intervention was recommended in the form of recession
trochleoplasty and a modified tibial tuberosity transposition, along with
imbrication and releasing incisions. Sheep may have a genetic predisposition for
patellar luxation.
PMID- 10687015
TI - [Three patients with unrecognized orthostatic intolerance].
AB - Three patients, men aged 20, 50 and 56 suffered from orthostatic intolerance and
syncope for years, despite visits to many doctors. Medical history and
cardiovascular reflex investigation revealed problems with the orthostatic blood
pressure regulation, caused by initial orthostatic dysregulation, vasovagal
syncope and pure autonomic failure, respectively. A structured medical history as
well as blood pressure measurements in the supine and standing positions can
reveal the diagnosis in many instances of syncope. After confirming the
diagnosis, the first concern is a clear explanation of the underlying problems to
the patient. Treatment with volume expansion should be considered.
PMID- 10687016
TI - [Handling small relative risks in science and management: the third-generation
pill].
AB - Small relative risks (a twofold or lesser increase in disease frequency) become
scientifically acceptable with (a) repeated consistent findings from studies that
(b) address the most important forms of bias and confounding, and (c) when there
is a plausible biologic mechanism. The third-generation oral contraceptive
controversy is an example of such a relevant but small relative risk and
demonstrates the problem of interpretation and implementation into medical
practice guidelines.
PMID- 10687017
TI - [Coagulation disorders in cancer patients: possible opportunity for therapy].
AB - Coagulation disorders occur often in cancer patients. Thrombosis or embolism may
be the first sign of an underlying malignancy. In addition, subclinical
coagulation disturbances have been found in the blood of cancer patients, for
example elevated concentrations of tissue factor or thrombin-antithrombin
complexes. In 20% of the patients thrombocytosis occurs, and for lung and colon
cancer it was found that thrombocytosis is an independent negative prognostic
factor for survival. The role of an activated coagulation cascade in tumour
growth is not completely clear, but there is strong evidence that the formation
of a temporary fibrin matrix stimulates the formation of new blood vessels
(angiogenesis) and supports tumour growth and metastasis formation. Preclinical
investigations demonstrated that tumour growth and metastasis formation can be
inhibited by anticoagulants. Clinical studies suggest a beneficial effect of
anticoagulants on the survival of cancer patients, but phase III randomised
clinical trials should be performed to determine the effect of longterm
administration of anticoagulants.
PMID- 10687018
TI - [Gastro-intestinal surgery and gastroenterology. V. Chronic pancreatitis:
gastroenterologic aspects].
AB - Chronic pancreatitis causes irreversible damage to the pancreatic parenchyma and
ultimately leads to exo- and endocrine insufficiency. In the Western world,
alcohol is the main cause of chronic pancreatitis; part of the patients with
idiopathic or alcoholic pancreatitis conceivably have a raised sensitivity to the
toxic effects of alcohol because of a certain genetic predisposition. The most
striking symptom, severe recurrent or persistent pain is often difficult to
manage. Various forms of imaging examination provide complementary information on
lesions of the pancreatic parenchyma, the pancreatic duct, the bile ducts and
adjacent structures; ultrasonoscopy is the technique of first choice in case of
suspicion of a pancreatic disorder. Endoscopic therapies are booming:
sphincterotomy, calculus extraction, insertion of an endoprosthesis in the
pancreatic duct and drainage of pseudocysts (transpapillary or through the
jejunum or stomach).
PMID- 10687019
TI - [Gastrointestinal surgery and gastroenterology. VI. Chronic pancreatitis:
surgical aspects].
AB - The indications for surgical treatment of chronic pancreatitis are intractable
pain or local complications. The purpose of preoperative investigation, apart
from establishing the indications for operation, is to select the kind of
procedure to be performed. Important factors include narrowing or dilatation of
the pancreatic duct and the presence or absence of an inflammatory mass in the
pancreas and of pseudocysts. A pylorus preserving pancreatoduodenectomy or
duodenum preserving pancreatic head resection is performed in case of an
inflammatory mass in the pancreatic head. In limited clinical trials, duodenum
preserving resection was associated with better recovery, this also applies to
the Frey procedure, consisting of local resection of the pancreatic head in
combination with lateral pancreaticojejunostomy. In case of dilatation of the
pancreatic duct (> 8 mm), without an inflammatory mass drainage of the pancreatic
ductal system by a lateral pancreaticojejunostomy is appropriate. A pancreatic
tail or body resection can be performed for inflammatory lesions confined to the
pancreatic tail or body. Symptomatic pseudocysts are drained internally into the
stomach, duodenum or a jejunal loop.
PMID- 10687020
TI - [Limited changes in prescription of third-generation oral contraceptives after
reports on elevated thrombosis risk and subsequent professional guidelines].
AB - OBJECTIVE: To compare the prescription behaviour of general practitioners (GP)
and gynaecologists regarding 2nd and 3rd generation oral contraceptives (OC) in
the period before and after the warning of increased thrombosis risk of 3rd
generation pills. DESIGN: Retrospective, descriptive. METHOD: With the aid of
data on OC prescriptions collected by the Institute for Medical Statistics, the
numbers of prescriptions from Dutch GPs and gynaecologists in the year before the
warning by the British Committee on Safety of Medicines that 3rd-generation OC
increased the risk of thrombosis, were compared with the numbers in the year
after publication of the guideline of the Dutch General Practitioners Society
(NHG), which stated a preference for the 2nd-generation OC, and of the guideline
of the Dutch Society for Gynaecology and Obstetrics, which stated no preference.
RESULTS: In neither the GP nor the gynaecologist groups did the proportion of 3rd
generation pills in the OC prescriptions decrease significantly. However, in the
GP group the proportion of new 3rd generation OC prescriptions decreased
significantly from 56 to 40%. However, after a few trimesters it rose again.
CONCLUSION: The changes in prescription behaviour of the GP group were in
accordance with the NHG guidelines. However, the proportion of the 3rd-generation
OC prescriptions remained relatively large and the effect was of short duration.
The only conclusion that could be drawn regarding the gynaecologists, was that
the proportion of 3rd-generation OC prescriptions did not change significantly.
PMID- 10687021
TI - [The effect of oral contraception on society].
AB - Oral contraception was introduced 40 years ago. In the Netherlands 'the pill' was
more widely accepted than in most other countries. Oral contraception turned
family planning into a medical responsibility, which made it respectable. It also
separated sexuality from reproduction, which had rather far-reaching consequences
for sexual behaviour and experience, as well as for sexual morality. The most
important immediate impact of the pill was a sudden acceleration of the downward
trend of the birth rate, and a substantial reduction in the number of unwanted
pregnancies and so-called forced marriages. Its impact on world population growth
has been less marked, mainly because of its costs, as on a global level
sterilization and intrauterine devices are more important methods of
contraception. The number of abortions in the Netherlands (5-6.5/1000 fertile
women/year) has not decreased, but the current possibilities for family planning
have led to a change in motivation from 'utterly unwanted pregnancy' to
'unintended pregnancy'.
PMID- 10687022
TI - [Favorable effects of vitamin A in measles infection].
AB - The recent measles epidemic that hit the Netherlands in 1999 resulted in numerous
hospitalisations and several fatalities, and resembled the previous epidemic of
1987-1988 in numbers and severity. The triple (parotitis epidemica, measles, and
rubella) vaccine used in the nationwide, free-of-charge immunization programme is
highly effective, but is not accepted for ideological reasons by specific groups
in the Dutch community. High oral doses of vitamin A have been shown to reduce
mortality and pulmonary and gastrointestinal complications of measles in children
in developing countries, but this treatment option is little known to physicians
in the Netherlands. The appropriate dose regimens for safe administration of
vitamin A in complicated measles are: age under 6 months 50,000 IU, age between 6
months and 2 years 100,000 IU, and age over 2 years 200,000 IU, administered by
mouth upon admission. A repeated dose can be administered on the following day.
In the Netherlands, and elsewhere, universal measles immunisation remains the
first goal in the fight against this highly contagious disease.
PMID- 10687023
TI - The Child Behavior Checklist (CBCL) and related material: standardization and
validation in Danish population based and clinically based samples.
AB - The Child Behavior Checklist (CBCL) and related material, developed by Achenbach
and Edelbrock in Vermont, was validated in a mailed survey. A population based
sample of 779 children between the age of four and 17 years was compared to a
sample of 146 children referred for child psychiatric service. Danish children
scored very much like our Scandinavian and German neighbours, but low compared to
most others. The CBCL mean 'total behavior problem score' in the population was
17.7. The checklists, especially the parent and teacher versions, provided good
construct validity. Youths generally reported more emotional problem behavior
than their parents and teachers did about them. In general, parents and youths
agree more, reporting emotional problems, and parents and teachers agree more,
when scattering externalizing behavior. Short screening constructs are
introduced, and by the use of latent trait analysis, four clinically relevant sub
scales were generated. Predictive value, sensitivity, specificity and clinical
validity must be undertaken in a future two-phase study.
PMID- 10687024
TI - Has the Department of Health backed itself into a corner?: Anonymization of data
may not protect against breach of confidentiality.
PMID- 10687025
TI - Drug-induced hepatotoxicity: pharmacokinetic perspectives and strategies for risk
reduction.
PMID- 10687026
TI - Free radicals as mediators of alcohol toxicity.
AB - In this article we have reviewed recent evidence in support of the hypothesis
that acute/chronic alcohol toxicity is mediated primarily via the generation of
damaging free radical species in various tissues. Studies in man, animal model or
in vitro experimental systems have shown: (1) the demonstration of alcohol
induced free radical species directly via esr spectroscopic analysis; (2)
increases in indirect markers of ethanol-induced free radical damage in tissues,
such as lipid peroxides and protein carbonyl; (3) ethanol-induced alterations in
the levels of endogenous tissue antioxidants. These data show the induction of
free radicals by ethanol to be a complex interactive process. The classical
pathway for ethanol metabolism, catalysed by alcohol dehydrogenase to form
acetaldehyde, results in the formation of free radicals, resulting from
concomitant changes in NADH levels and NADH/NAD+ redox ratios, which in turn
modulate the activity of the free radical generating enzyme xanthine oxidase. The
induction of CYP 2E1 in the microsomes results in the generation of HER, another
major route by which ethanol induces free radical formation. In addition to the
above, ethanol may also induce free radical formation via the reaction of
aldehyde oxidase with acetaldehyde or NADH to generate oxyradicals via
disturbance in the metabolism of the pro-oxidant iron, or via increased efflux
from mitochondria following altered mitochondrial oxidative metabolism.
PMID- 10687027
TI - [Antimicrobial agents in the future. The contribution of genomics to their
design].
PMID- 10687028
TI - [The outlook for the design of preparations active in relation to resistant forms
of bacteria].
PMID- 10687029
TI - [The origin, evolution and clinical significance of antibiotic resistance].
PMID- 10687030
TI - [The importance of fluoroquinolones in treating pneumonia in the elderly].
PMID- 10687031
TI - [The place of fluoroquinolones in the treatment of bacterial infections].
PMID- 10687032
TI - [Antibiotics and the macroorganism].
PMID- 10687033
TI - [Arterial hypoxemia and liver disease: a challenge for pneumology in the next
millennium].
PMID- 10687034
TI - [Descriptive analysis (clinical and functional characteristics) of an asthmatic
population in a health care district].
AB - OBJECTIVE: To determine the social, demographic, clinical and lung function
characteristics of the population of asthmatics living in Health Care District 2
of Madrid. STUDY DESIGN: Transversal (initial visit) phase of a primary care
community intervention study. The target population consisted of all asthmatics
in District 2 of Madrid who were registered at the public health clinics, were
older than 14 and had experienced asthma symptoms within the past year. The
selection of patients for the study was systematic (not probabilistic), such that
all registered asthmatics seeking care and/or scheduled for check-ups were
enrolled. Participation was 96.6% of those on file. We recorded social,
demographic, clinical, and lung function variables as well as results of allergy
studies, family histories of asthma and/or atopy and type of treatment. RESULTS:
Six hundred fifty patients were enrolled, 238 men (36.7%) and 412 women (63.3%).
Mean age was 45 +/- 28.1 yr, mean FEV1% was 87.2 +/- 26%. Mean course of disease
was 16 +/- 14.6 yr and age of onset was 26 +/- 20 yr. Family history of asthma
was present in 34% of cases and a family history of atopy was reported by 21%.
Half had allergic rhinitis as an associated factor, with respiratory infections
(62.4%) being the most common trigger, followed by pollen (25.3%) and exposure to
tobacco smoke (20%). Active smokers accounted for 9.1% of the group, and ex
smokers for 21.6%. Short-term beta-adrenergic drugs on demand were used by 64% of
patients, whereas 83.2% reported daily and long-term use of beta-2 drugs and 77%
used inhaled steroids. Severity of disease differed significantly by age of
patient, age at onset and predominance of perennial asthma (with older age and
age of onset and greater seasonality observed among severely asthmatic patients).
CONCLUSIONS: a) Most symptomatic asthmatic have mild disease. b) Rationally
adjusted, appropriate drug treatment should be graded according to level of
disease severity.
PMID- 10687035
TI - [Usefulness of fiberoptic bronchoscopy in critical pediatric care].
AB - Fiberoptic bronchoscopy (FB) is being applied increasingly in pediatrics as a
therapeutic and diagnostic technique. OBJECTIVE: To analyze the contribution of
FB to the diagnosis and treatment of respiratory disease in patients admitted to
the pediatric intensive care unit (PICU). PATIENTS AND METHOD: We reviewed FB
performed with 3.5 and 2.2 mm external diameter instruments between January 1989
and October 1998 in patients admitted to the PICU. Underlying disease and purpose
of and indications for FB were analyzed. We also analyzed route of insertion,
findings of airway inspection and bronco-alveolar lavage (BAL), complications and
the contribution of FB to patient management. RESULTS: A total of 51 procedures
in 47 patients aged between ten days and 12 years old were performed. Twenty-one
children (41%) were under one year old. The initial indications for FB were
diagnostic in 73% and therapeutic in 27%. Airway inspection showed abnormality in
65%. BAL was performed in 18 cases, with microbiological findings in 8 of the 18.
The patients benefited directly from the technique in 75% of cases. CONCLUSIONS:
FB is useful diagnostic and therapeutic procedure in PICU patients and is
generally well tolerated.
PMID- 10687036
TI - [Asthma emergencies: can we lower the rate of readmission after discharge?].
AB - INTRODUCTION: The rate of readmission among asthmatic emergency patients varies.
In 1991 we observed a 9% rate of readmission following emergency room release.
Studies of the number of readmissions or request for medical care are used as the
basis for recommendations for releasing patients from hospital emergency care. No
studies have assessed disease stability following release or factors related to
stability. OBJECTIVES: To assess the course of disease and clinical stability of
patients in the period immediately following release from emergency room care. To
determine factors that might predict such stability. to determine the rate of
readmission in the month following release after applying a treatment protocol
and release criteria, with follow-up examination 72 h later. MATERIAL AND
METHODS: Prospective, descriptive study with follow-up 72 h and one month after
release. SETTING: Emergency and pneumology departments of a general hospital.
PERIOD: six months. PATIENTS: 82 asthmatic patients released from the emergency
room. RESULTS: Two patients (2.43% were readmitted. At the first follow-up visit
(72 h) 81 patients (98.78%) were seen. At the second visit, 66 patients (80.5%)
were examined. We observed stability in 70.3% of patients at 72 h and in 86.4%
after on month. Stability was statistically related to whether peak expiratory
flow greater or less than 70% (76.92% stable versus 46.66% unstable) (p < 0.05).
No other clinical, epidemiological or treatment variables recorded upon release
were found to influence stability. CONCLUSIONS: 1) A large proportion of patients
are in stable condition 72 h after release. 2) When peak expiratory flow upon
release is > 70%, stability is significantly increased 72 h later. 3) Our 2.43%
rate of readmission one month after release is very low. 4) No differences in
stability were seen to be related to oral corticoid prescription upon release.
PMID- 10687037
TI - [Nasal nicotine spray in smoking cessation. Results of a multicenter study].
AB - We have carried out an open multicenter follow-up study of the efficacy of a
smoking cessation therapy that combined psychological support with use of a
nicotine nasal spray. Fifty-seven subjects (37 men, 20 women) with a mean age of
40.3 +/- 15.7 yr and smoking 37.4 +/- 4.7 cigarettes per day were enrolled. The
mean Fagerstrom test score was 8.9 +/- 1.1. Patients received minimal
psychological support and were prescribed a nicotine nasal spray at the
recommended dose of 1 to mg/h for use while awake for a period of three months,
with gradual reduction of dose. Subjects were seen on six occasions (on the first
day of consultation; 1, 2 and 6 weeks after quitting; 3 and 6 months after
quitting). After three months of follow-up, 22 patients (39%) were abstinent; six
months after first trying to quit, only 20 of the 57 enrolled had succeeded
(35%). Although most subjects (over 90% in the first 15 days, and over 50% at
three months) used the treatment, only a small percentage (3%) followed the
appropriate doses in the first 15 days and 31% reported doing so at the three
month check-up. The mean score reflecting withdrawal syndrome tripled over
baseline level during the first six weeks of follow-up. Over three quarters of
the subjects suffered side effects caused by the spray, the most common being
nasal irritation, rhinorrhea and tearing. Five patients (87%) lef the study
because of intolerance to medication. In conclusion, our study found a rate of
success of 35% after six months of follow-up. Use of the prescribed medication
was inadequate; withdrawal syndrome was more intense and the prevalence of side
effects increased during the early treatment period.
PMID- 10687038
TI - [A comparative study of patients with chronic obstructive pulmonary disease with
and without obstructive sleep apnea syndrome].
AB - We aimed to study whether the presence of obstructive sleep apnea syndrome (OSAS)
in patients with chronic obstructive pulmonary disease (COPD) led to differences
in clinical picture, gas exchange during awake and sleep states and mechanical
ventilation, in comparison with patients with COPD alone. We enrolled 48 COPD
patients. In 26 (54.1%), OSAS was ruled out (non-OSAS COPD group) by
polysomnography, and in 22 (45.8%) associated OSAS was diagnosed (OSAS COPD
group). Patients in the OSAS COPD group experienced greater daytime sleepiness
and less dyspnea. Body mass index was not significantly difference. The OSAS COPD
group had significantly lower daytime PaO2 (66.4 +/- 10.4 mmHg in the OSAS COPD
group and 75.5 +/- 11.2 mmHg in the non-OSAS COPD group; p = 0.01); there were no
differences in PaCO2.Pimax in the OSAS-COPD group was 70.6 +/- 23.8 cmH2O, a
level that was significantly lower than in the non-OSAS COPD group (Pimax 90.5 +/
26.1 cmH2O; p = 0.04). Patients in the non-OSAS COPD group experienced longer
periods of REM sleep. Nighttime saturation parameters were significantly
different in the group with OSAS. We conclude that patients with both OSAS and
COPD experience greater oximetric changes than those without OSAS, during both
sleep and awake states. The deterioration of respiratory muscle pressures in such
patients may play an important role in the changes. The groups also present
differences in the intensity of some symptoms, such as degree of daytime
sleepiness and dyspnea.
PMID- 10687039
TI - [The management trap in medicine. Introduction to a needed discussion].
PMID- 10687040
TI - [Pulmonary toxicity caused by drugs].
PMID- 10687041
TI - [Acute respiratory insufficiency as initial manifestation of brain stem lesions].
AB - We describe three patients with different brainstem lesions (bulbar angioma,
bulbar infarct, and Arnold-Chiari malformation) who debuted with acute
respiratory insufficiency. Other neurological manifestations had gone unobserved
in all three cases. Respiratory insufficiency worsened notably during sleep to
the point that mechanical ventilation was required or death occurred (Ondine s
curse). The patient with a bulbar angioma is stable with only assisted
ventilation by a nasal route at night, with good quality of life. Our conclusions
are that: a) central nervous system anomalies need to be investigated as possible
causes of respiratory insufficiency when lungs are normal; b) the respiratory
control of patients with brainstem lesions should be studied, particularly at
night (polysomnography), and c) even when awake-state ventilation is adequate,
nighttime assisted ventilation may be required.
PMID- 10687042
TI - [Benign metastasizing pulmonary leiomyomatosis. A report of 3 cases].
AB - The benign metastasizing leiomyoma is an uncommon variety of leiomyoma, tumor
derived from smooth muscular tissue. The benign metastasizing leiomyoma affects a
middle age women, with antecedents of uterine leiomyoma, the pulmonary lesions
appeared as a multiple nodules, without systemic affectation. We present three
cases of benign metastasizing leiomyoma that de diagnosis was made for biopsy by
thoracotomy; and in one case the markers from estrogens' receivers were positive.
PMID- 10687043
TI - [20210G/A mutation of prothrombin gene in a patient with deep venous thrombosis
ad pulmonary embolism without other risk factors of thrombosis].
AB - A new genetic anomaly predisposing to venous thrombosis was described in 1996,
namely the transition of guanine (G) to adenine (A) at position 20210 in the 3
untranslated region of the prothrombin gene. This mutation is associated with
high levels of plasma prothrombin and increased risk of thrombotic events in the
venous system. We report the case of a man who, lacking known risk factors for
thrombosis, suffered a massive pulmonary embolism and deep venous thrombosis in
both lower legs. Thrombophilic analysis confirmed that the patient and close
relatives were carriers of the heterozygotic 20210G/A variant of the prothrombin
gene. Two relatives with the genetic defect had also suffered some type of deep
venous thrombosis.
PMID- 10687044
TI - [Chylothorax caused by fracture of the humerus and resolution after conservative
treatment].
PMID- 10687045
TI - [Peripheral neuroectodermal tumor of the posterior mediastinum in an aged
patient].
PMID- 10687046
TI - [Neurogenic pulmonary edema after epileptic crisis].
PMID- 10687047
TI - [Bronchial spasm and eosinophilia related to administration of fosinopril].
PMID- 10687048
TI - [On the question of arbitrary "selection" of genetic code].
PMID- 10687049
TI - [Irreversible changes in the ultrastructure of kinetochores in mitosis, caused by
human cytomegalovirus].
PMID- 10687050
TI - [Cellular-population mechanisms of regulation during tumor growth].
PMID- 10687051
TI - [Site-specific cleavage of yeast tRNA(Phe) by derivatives of oligonucleotides
bearing bisimidazole groups].
PMID- 10687052
TI - [Crezacin--a new biostimulator of microbiological synthesis].
PMID- 10687053
TI - [Secretion of venom from the common viper (Vipera berus) under in vitro
conditions].
PMID- 10687054
TI - [Comparative study of changes in the quantitative characteristics of the frog
Rana temporaria cerebellar molecular layer structure when exposed to L-glutamate
and NO-generating compounds].
PMID- 10687055
TI - [Analysis of discrete variability of rodents using equilibrium population
properties].
PMID- 10687056
TI - [Combination of phosphazide and crixivan inhibit replication of HIV-1 strains
that are resistant to azidothymidine].
PMID- 10687057
TI - [The effect of annexins on the contractile activity of the smooth muscles in the
rat portal vein].
AB - This study examines the effects of the family of calcium-dependent phospholipids
binding proteins (annexins) on the contractile properties of rat portal vein. We
developed the new method of annexin's purification from pig stomach muscle. It
found that in nanomolar concentrations annexins caused dose-dependent effects on
phasic and tonic component of rat portal vein contractile activity. The frequency
of spontaneous contractions was increased whereas the amplitude was decreased. At
the same time we observed the rise of basal tone level of contractions. We
suggested that annexins may change the contractile properties of vascular smooth
muscle.
PMID- 10687058
TI - Intermittent hypoxia alters hypoxic ventilatory responses.
AB - Intermittent hypoxic training (IHT) shows promise for prevention and treatment of
some diseases and efficiently produces great advancement in athletic training. We
studied (1) hypoxic ventilatory responses (HVR) in supine and sitting positions
during normobaric, isocapnic, progressive hypoxia (rebreathing technique) and (2)
lung ventilation and gas exchange while breathing ambient air at rest and during
5 min of breathing 11% O2. Duel measurements were made pre- and post-15-day IHT
regimen on 12 (experimental) healthy males (24.6 y.o. +/- 1.9 y.o.) and on 6
(control) healthy males (24.2 y.o. +/- 2.3 y.o.) given pseudo-IHT (p-IHT) without
decreasing PiO2. IHT involved rebreathing eucapnic (chemically absorbed) air as
P(ET)O2 decreased to 35 mmHg, three 6-7 min sessions, three times a day, with 10
min breaks between each session over a 15 day training period. Without IHT, HVRs
were the same in sitting and supine positions at low levels of hypoxic challenge
(slope one--S1: P(ET)O2 from 110-60 mm Hg) and significantly higher (by 45%)
during severe hypoxia (slope two--S2: P(ET)O2 from 60-35 mm Hg). IHT caused an
increase in HVR in both sitting and supine positions: S1 by 70 and 100%, S2 by
158 and 200%, maximal lung ventilation by 35 and 78%, respectively. There were no
significant changes in the p-IHT group. IHT also caused enhanced respiratory
reactions during sustained hypoxia (lung and alveolar ventilation increased by 36
and 22%, respectively). A striking hypoxic ventilatory sensitivity was noted in
subjects with hyper-reactive breathing patterns.
PMID- 10687059
TI - [The status of the stress-limiting and stress-realizing links in adaptation in
newborn rabbits with experimental chronic fetal hypoxia].
AB - The model of chronic intrauterine hypoxia was made according to the method,
devised in physiology and experimental medicine laboratory of Institute of
Pediatrics, Obstetrics and Gynecology Ukrainian AM Sci. This method consist in
dose narrowing of the basal venous columns from cornua of uterus in rabbits on 14
15 days of pregnancy. The obtained experimental results confirm previous clinical
date about disturbances in antistress mechanisms of protection under chronic
fetus hypoxia. Evidently, this disturbances are the important pathogenetic links
in behinding of newborn rabbits in physical development and, especially, in its
lethality.
PMID- 10687060
TI - [The characteristics of the background neuronal activity of the rostral
hypothalamus and an analysis of its alteration under the influence of the
stimulation of phylogenetically heterogeneous sections of the cerebral cortex].
AB - In acute experiments on cats under mixed narcosis (ketamine + N2O) we have
investigated background firing activity of the rostral hypothalamic neurons and
analyzed it modifications due to serial stimulation (100 imp/s, during 5 s) of
the prefrontal, cingulate, pyriform cortices and hippocampus. Analysis of the
ongoing mean frequency histograms allowed to single out three types of background
firing activity with different rhythmical properties. Three types of interspike
intervals distribution i.e. asymmetrical (A), symmetrical (S) and polymodal (P)
have been distinguished as well. Cortical stimulation was found to transform
types of interspike intervals distribution in 15% of hypothalamic neurons. S-type
changed into P-type and A-type--into P-type. Author discussed correlation between
the character of background firing activity, types of interspike intervals
distribution and functional properties of hypothalamic neurons.
PMID- 10687061
TI - [The function of the oxytocin-synthesizing system of the hypothalamus in rats
with diabetes mellitus undergoing hypoxic training].
AB - The state of hypothalamic oxytocin-synthesizing system in Wistar rats were
investigating. The morphometric measurements and immunocytochemical detection of
oxytocin-containing cells was used for determining of the functional state of
supraoptic nucleus, anterior and posterior-medialis magnocellular subdivisions of
paraventricular nucleus. It was established intermittent hypoxic training exert
positive influence on rats with experimental diabetes mellitus. This effects
depending on increasing synthesis and secretion of hypothalamic oxytocin.
Intermittent hypoxic training elevate contents of immunoreactive oxytocin without
changing morphometric characteristics in neurons of supraoptic and
paraventricular nuclei and median eminence of hypothalamus. In comparison
oxytocin contents in these neurons elevade less significance in diabetic rats,
but it was observed increasing of nucleolus volume in hypothalamic oxytocin
synthesizing neurons. Intermittent hypoxic training of diabetic rats stimulate
more significance elevating oxytocin contents in hypothalamic neurons and median
eminence that evidence high level activity of hypothalamic oxytocin-synthesizing
system.
PMID- 10687062
TI - [The circulatory changes as dependent on the type of autonomic homeostasis in
divers in dives to a depth of 65 m].
AB - Investigations were performed during 24 simulated air dives under pressure 0.74
MPa in which 16 divers took part. Before, during and after dives intrathoracic
pressure, mean arterial pressure, ECG, rheoplethysmogram and intervalocardiogram
were recorded continuously with the Valsalva maneuvers. Variables of heart
pumping function, peripheral vascular system, phasic heart cycle structure were
calculated. For evaluation of autonomic homeostasis variational and spectral
analysis of cardiac rhythm were used. In hyperbaria a part of hemodynamic
response peculiarities to intrathoracic pressure increase were common to all
divers and caused by hyperoxia and increased density of breathing medium, which
lead to the appearance of bradycardia, decrease of cardiac output, peripheral
vasoconstriction enhancement. Other observed features were determined by
alterations in sympathetic and parasympathetic nervous system tonus. These
changes were rather complex and highly individual. Our data may benefit
evaluation of hyperbaric factor stressful action on blood flow and autonomic
nervous system.
PMID- 10687063
TI - [The characteristics of the morphofunctional status of 15- to 17-year-old youths
based on a comprehensive assessment of the rates of their biological
development].
AB - There were studied individual typological peculiarities of the genesis of the
genesis of 15-17 years old boys, the state of their respiration and their heart
activities. According to these experiments there was stated the possibility of
the complex appreciation of the biological tempos of genesis of the senior
grades' pupils on the bases of physical and somatic genesis and sexual maturity.
As a result of such differentiation of 15-17 year old boys there will appear 3
typological groups--fast, normal and slow types of genesis which quite differ by
the majority of grades. Besides these 3 groups differ by the functioning of
cardiorespiratory system. Boys with fast tempos of genesis are closer by the
functioning peculiarities of cardiorespiratory system to the normal tempos of
genesis which are understudy. The group with the slow genesis is quite different
from the groups with the fast and normal genesis.
PMID- 10687064
TI - [The in-vitro resumption of meiotic maturation and of the first polar body by
mouse oocytes at different stages of the estrous cycle].
AB - Resumption of the meiotic maturation and extruded the first polar body of the
murine oocytes was registered at 2 and 14 hours under culturing in the medium
containing 1.7 mM Ca2+. There were differences between the groups in the
percentage of GV oocytes with zona pellucida that acquired competence to undergo
germinal vesicle breakdown (GVBD) at 2 hr time point 22.2% of "small" and 32.4%
of "large" follicles of mouse at dioestrus and, respectively, 28.1% and 41.8%
follicles of mouse at oestrous underwent GVBD. At 14 time point 21.4% of "small"
and 30.3% of "large" follicles of mice at mice at dioestrus and, respectively,
26.1% and 43.6% follicles of mouse at oestrous underwent GVBD and (then) extruded
the first polar body (FPB). It may be suggested, that acquisition of competence
of the oocytes to resume meiosis in vitro depends on the size of follicles and
the stage of murine oestrous cycle. Thus, the largest percentage of GV oocytes
resuming meiosis was from "largest" follicles of mouse at oestrous.
PMID- 10687065
TI - [The balance of elastase and its inhibitors in the vascular tissues of rabbits of
different ages in the early stages of experimental Monckeberg-type
arteriosclerosis].
AB - The role of the elastolytic system in pathogenesis of vascular diseases was
investigated on adult and one-month old rabbits in experimental ergocalciferol
induced media calcinosis depending on age aspect. The obtained results indicate
that elastase activity was increased in aortic homogenates of one-month old
rabbits but not in adult animals. The level of alpha 1-proteinase inhibitor is
reduced in one-month old rabbits, and decrease of the alpha 2-macroglobulin
content in arterial walls occurs in adults. A higher level of antielastase
proteins in both groups of animals in venous vessels is determined. After effect
of ergocalciferol in the veins of one-month-old rabbits, differs from the adults,
a significant increase of the inhibitor content is observed. The presented
results confirm the importance of balance between elastase and it inhibitors in
pathogenesis of arteriosclerosis.
PMID- 10687066
TI - [Compensatory changes in the acid-base balance under the influence of excess
ammonium chloride, hypodynamia and stress].
AB - Two variants of alternative integrative compensatory mechanisms of metabolic
reactions in organism developing at the compensated shifts of acid-base balance
under the influence of different risk factors have been discovered by the
authors. Compensated metabolic acidosis appears with the excess of salt ammonia
in the animals ration, at the immobilization stress, hypodynamia, deafferentation
and surgical stress. The start reaction of acidosis is lipolysis activation and
nonacidified products accumulation at the reactions of tricarboxylic acid cycle
are (TAC) inhibited. The compensatory mechanism directed to bind hydrogen ions
and prevent pH shifts is activity of glyconeogenesis reactions, transamination,
increase the contents ammonia, as well as by increases of restored combinations.
Carbohydrates excess in the ration, emotional stress (anxiety expectation) lead
to the metabolic alkalosis development at which low hydrogen ion formation and
their rapid use in the activated process of peroxide lipids oxidation is
compensated with the increase of organic acids formation in glycolysis and TAC as
well as by the increase of oxidation properties in tissues. Besides adaptive
physiological meaning, the described mechanisms may be the reason for a number of
pathological state appearance. The discovery in population and prevention of
endogenic risk factors prevention is principle new basis of modern integrated
system of human and animals common diseases prevention.
PMID- 10687067
TI - [The biological significance of the genetically determined Se-se human blood
group and its effect on the antibody formation process in donors immunized with
staphylococcal anatoxin].
AB - 82 blood donors have been observed, 63 of them were immunized. Blood group
ABO(H), secreting group Se--se and Staphylococcus antibody contents (anti-alpha
staphylolysins) were determined in all the donors. It was found out that the
donors-secretors with A(II) blood group exhibited the antibody-production
increasing. It is supposed that the secreting of group-specific substance A, that
has structural elements similar those of staphylococcus into saliva promotes
antibody production increase against staphylococcus. The mechanism of such
specific stimulation remains to be unknown and requires further studying.
PMID- 10687068
TI - [The reaction of regenerating connective tissue to acetylcholine in the dynamics
of the denervation-reinnervation process].
AB - The granulation tissue of wounds on upper surface of feet on the 7th day under
repeated acetylcholine (Ach) application (0.02 g/1) was studied. In the control
group, Ach-induced intensification of inflammatory process and bad condition of
regenerating tissue of skin. This pathological reaction increased (fastly
appeared ulceration) at once after crushing of right sciatic nerve in the
denervated wound. It was less pathological in the contralateral (innervated)
wounds. The effect of ACh was positive on later term of neurodystrophic process
in the denervated wound and in the contralateral one. Cholinoceptive of
granulation tissue of bilateral wound became normal after reinnervation.
PMID- 10687069
TI - [The effect of enterosorption on the local immune processes in a toxic lesion of
the large intestine].
AB - The local immune homeostasis changed of the colon play a significant role in the
pathogenesis of toxic colitis, induced by lead acetate. Chronic toxic colitis is
accompanied by a considerable redistribution of plasmocytes-producers of the main
immunoglobulins classes in the colon walls towards a primary IgA producers
increase, a correlation between them and the local immune reactions tension and
destabilization as well. Enterosorbent SCNP-2 influence on a pathological process
in the colon under the chronic lead intoxication results in the local immune
reactions improvement in the studied organ, its functional and structural
elements impairment rate reduction as well as their adaptive properties increase.
PMID- 10687070
TI - [Changes in the respiratory functional status of children exposed to the chronic
effect of ionizing radiation as a consequence of the Chernobyl catastrophe].
AB - Investigating the functions of the respiratory system some disorders of the
ventilation capacity and the lung respiratory functions, external respiration,
hypoxic changes in circulatory type at the functional loadings were revealed in
children exposed to chronic radiation effects during the postaccident period. It
was supposed that an increase in the intensity of free radical processes in the
body and the presence of dysadaptation conditions are the basis of changes
revealed.
PMID- 10687071
TI - [The features of the psychophysiological functions in older preschoolers and
younger school-age children and the influence on them of social isolation].
AB - Psychophysiological properties and psychophysiological rating as an integral
index of human mental efficiency were measured for elder preschool children, 1-2
nd grade students of primary school and also for elder preschool children and 2
nd grade students of boarding school for orphaned children. It was shown
development of psychophysiological properties with age. An influence of social
isolation caused to slowing down in development of psychophysiological
properties, especially of indices of functional level of system and precision of
reaction on moving object.
PMID- 10687072
TI - [The age-related characteristics of human mental work capacity].
AB - The aim of investigation was to study the ageing peculiarities of human mental
working capacity with mathematical models. Were examined 150 women and 125 men in
five aged groups: 13-18, 19-29, 30-39, 40-49, 50-60. The human mental activity
was presented with special computer's tests. The regression ageing models for
assessment of mental working capacity is proposed. The study showed that high
level of human mental working capacity is determined with the decreasing of
mental experience variation and the increasing of speed of remaking the
information.
PMID- 10687073
TI - [The humoral reactions of bioincompatibility in the early period after the
heterotopic autograft of veins into the coronary bed and the implantation of
synthetic heart valves].
AB - Humoral manifestations of bioincompatibility were studied at early stages (during
several hours and days) after operations using non-peculiar to heart trans- and
implants: aortocoronary bypass at 102 patients with coronarosclerosis and
implantation of artificial cardiac valves at 145 patients with endocarditis. In
the various postoperation stages the formation of the structurally and
functionally different types of the nonclonal specific autoprecipitins to
autological membranocellular components was revealed at recipients by methods of
double immunodiffusion and immunoelectrophoresis. These autoprecipitins such as:
early, activated and tardly, synthesized under effect of alien agent--may be
useful as diagnostic and prognostic indicators of bioincompatibility and its
clinical consequences at the earliest period after cardiac operations using trans
and implants.
PMID- 10687074
TI - [The effect of a grape extract on the contractile activity of the myocardium and
on the coronary flow of the isolated guinea pig heart].
AB - Effects of one of the fraction of grape extract on myocardial contractility and
coronary flow of isolated guinea pig heart have been investigated. It was shown
that the administration of grape extract led to myocardial contractility index is
increase by 77%, coronary flow increase by 13% and oxygen consumption increase by
30%. Inhibition of nitric oxide synthesis by L-NMMA resulted in decrease of grape
extract-induced coronary flow increase. These data support of isolated strips
investigation that grape has a compounds which induced endothelium-dependent
vasodilation of coronary bed. They indicate that these substances have the strong
cardiostimulating effect.
PMID- 10687075
TI - [The length-force dependence of vascular smooth muscles and the nitric oxide
system in a chronic deficiency of mesostriatal dopamine].
AB - This study investigated the influence of the chronic cerebral dopamine deficiency
after 6-hydroxydopamine lesions of dopaminergic mesostriatal system and NO
pathways on the length-tension relation in vascular smooth muscles to their
distension. Experiments were performed on isolated strips of rat portal vein. The
results indicate that the attenuated contraction responses and the increased
stiffness of vascular smooth muscles to the distension in a chronic mesostriatal
dopamine deficiency. It was found that these responses may be, in part,
normalized after a long-term L-arginine administration. The same changes were
marked in the responses of intact vascular strips after the inhibition of NO
synthase activity and L-arginine perfusion. It has been suggested that, in a
chronic mesostriatal dopamine deficiency, the reduced vascular reactivity was due
to the decreasing of NO synthesis by endothelium and L-arginine could be used in
the treatment of these vascular disorders.
PMID- 10687076
TI - [The nonoliguric form of kidney failure in the posthemorrhagic period].
AB - At research of rules of deviations of the parameters homeostasis for patients
with bleedings we pursued to find dependence of the parameters of homeostasis
from function of kidneys. The researches were carried out in the early
posthemorrhagic period on an example of inspection of the patients who were
operated concerning gastrointestinal and intraabdominal hemorrhages. Is revealed,
that the renal insufficiency, which arose at 23.21% surveyed, proceeded without
oliguria--in the neoliguric form. It was characterized by normal speed diuresis,
despite of the essential damages of the function of nephron: infringement of a
primary filtration in glomerulus, reabsorption of water and electrolytes in
tubules, restriction of excretion H+. Normal diuresis in such cases was explained
by the early and duly beginning of the infusion therapy, owing to what, probably,
the infringement of passableness tubules was prevented. Despite of it, the
patients with the damaged function of kidneys require the careful control of
spent therapy because of an opportunity of dangerous deviations of the parameters
homeostasis of norm. Confirmation it became the reduction, fixed at such
patients, clearance of electrolytes, infringement of the extraction of acid by
kidneys.
PMID- 10687077
TI - [The adaptation of youth with different rates of morphofunctional development to
physical loading].
AB - There were studied morphofunctional peculiarities of biological development of 15
17-year-old boys' organisms on the bases of complex use, for this, of the level
of physical development, rates of sex maturity and somatotype. On that base there
were studied the individual peculiarities of their adaptation to the physical
loads, which was directed to the development of endurance. It was ascertained,
that the boys of the examined age groups, based on the complex differentiation
are divided into 3 basic groups--fast, normal and slow rates of genesis. These
typological groups differ by the measure and quantity of periods of long-term
adaptation, and by the nature of adaptable changes in the organisms which are
studied as a result of influence of long-lasted dosing loads, directed to the
development of endurance.
PMID- 10687078
TI - [The effect of the duration of coronary occlusion on the healing of an
experimental myocardial infarct].
AB - Increasing the period of myocardial ischaemia prior to conduction of reperfusion
adequality induces complicated healing of experimental myocardial infarction,
thereby resulting in postinfarctional aneurysm of the heart. Complicated healing
of myocardial infarction upon of coronary blood re-circulation after 3 or more
hours of ischaemia, happens due to disbalance of necrotic and reparative
processes in the infarct zone. Conduction of reperfusion induces activation of
necrotic processes with retention and slowdown of reparative processes.
PMID- 10687079
TI - [The comparative effect of magnetic and laser irradiation of the liver and blood
on the bile-secretory function in rats].
AB - The influence of percutaneous magnetolazer irradiation of the blood and liver on
the bile secretion, general bilirubin excretion and its fractions, cholesterol
and bile acids rate was studied experimentally on male rats. A laser generator
"Luch-2" with a magnetic nozzle (wave-length 0.82 mm, power density 0.178 W.cm-2,
magnetic field tension 30-35 mT, the course s 2 daily procedures) was used. Bile
secretion intensity was noted to depend on the dose. Maximal bile secretion and
its basic components were observed during the liver irrigation with an exposition
for 120 s and blood ones with an exposition for 240 s respectively. Bile
secretion rate was higher during magnetolazer influence on the blood. Liver
irrigation was associated with an increased secretion of the conjugated
bilirubin. Thus, there are various stimulant mechanisms of the liver function
activity in the course of magnetolazer influence on the liver and blood.
PMID- 10687080
TI - [The protective activity of anti-Proteus blood preparations].
AB - Human blood anti-Proteus preparation activity has been studied on the model of
Proteus etiology sepsis in white not pedigree mice. It has been found out that
anti-Proteus plasma and anti-Proteus immunoglobulin with antibody titre 1:80
possess marked therapeutic properties. The obtained results of the experimental
studies are the grounds for clinical studies carrying out with the use of blood
anti-Proteus preparations in combined therapy of the patients with diseases of
Proteus etiology.
PMID- 10687081
TI - [The effect of aromatic plant substances on the status of oxidative-reductive
enzymes in a chronic experiment].
AB - In chronic experiment (during 3 months) was studied the influence of various
vegetable aromatic substances (VAS) contents in the air upon oxidative
restoration enzymes activity in experimental animals (Wistar line male rats). On
the base these experiments' results may be made a conclusion that the lack of VAS
in the air involves changes in the most important enzymes of glycolysis and
pentosophosphatic cycle. Provision of the atmosphere with essential lavender oil
in concentration 0.58 mg/m3 (natural concentration) may correct such
disturbances.
PMID- 10687082
TI - [The effect of divalent cations on pepsinogen extrusion by permeable isolated
gastric glands].
AB - The model of permeable gastric glands obtained by its incubation with digiton (15
mg/ml) had investigated. It was shown, that stimulated influence of Ca2+ ions on
pepsinogen extrusion completely or partly reproduced by cations of transient
metals. Stimulated effects of cations of metals (5 x 10(-4) M) decrease in such
order: Ca2+ > Cd2+ > Mn2+ > Co2+ > La3+. Nevertheless, Co2+ and La3+ in the same
concentrations inhibit Ca2+ stimulated extrusion of pepsinogen by permeable
isolated glands. Stimulated effect of Cd2+ and La3+ on pepsinogen extrusion in
native glands was not reproducible. Besides these cations inhibit carbacholine
stimulated extrusion in native glands. It's concluded, that influence of metal
cations on secretory function of gastric glands to a great extent is determined
by their property to penetrate into secretory cells and cooperate with their
plasma membranes.
PMID- 10687083
TI - [The effect of sodium alpha-glutarate on enzymatic transamination activity and on
succinate dehydrogenase in rats with different resistances to hypoxia].
AB - It have been found that intraperitoneal alpha-ketoglutarate injection (20 mg/100
g body weight) results in increase in the influence of cholinergic regulation
mechanisms. It also results in increase of aminotransferase activity on
background of the decrease of succinate dehydrogenase activity in liver and
pancreas tissues and in small intestines mucous. Activity of transamination
enzymes and succinate dehydrogenase activity is much higher in the case of rats
with high hypoxia resistance, alpha-ketoglutarate injection results in increase
of transamination enzymes activity in the organisms of rats with low resistance
to hypoxia up to the control level of rats with high resistance, and
simultaneously increases rats resistance to hypoxia. Effect of alpha
ketoglutarate injection on the energetical exchange in the tissues with different
parasympathetic dependence taking from the animals with different hypoxia
resistance is suppressed by blockade of M- and H-cholinoceptors.
PMID- 10687084
TI - [The physiological and biochemical indices of the disposition of rats to alcohol
use].
AB - Activity of aldehide dehydrogenase (ALDH), alcohol dehydrogenase (ADH) in
cytoplasmic fractions of brain structures (hypothalamus, midbrain, new cortex)
and in blood serum as well as the content of noradreneline (NA) and dofamin (DA)
in the mentioned structures and blood of rats preferring ethanol (PE) and
rejecting ethanol (RE) has been investigated. ALDH isoforms have been revealed in
rats preferring ethanol (PE) and these rejecting it (RE). The activity of the
revealed forms of ALDH is higher in PE rats that in RE rats. PE and RE rats do
not differ from one another as to ADH activity. It is shown that the NA content
is decreased in PE rats and the DA level is increased in a number of brain
structures and in blood as compared to RE rats.
PMID- 10687085
TI - [The effect of prolonged physical loads on the cardiovascular system of middle
school-aged pupils].
AB - The cardiovascular system of schoolchildren at the age of 11-15 was studied as
affected by systemic of long lasting physical loads of schoolchildren. In the
trained children contrary to adults the respiratory arrhythmia is observed, that
evidences for nonadequacy of the physical load to the functional state of
myocardium. In the cardiovascular system of the trained schoolchildren under the
effect of constant training there occurs a series of functional changes which
increase adaptation to physical loads, that is manifested in a decrease of the
systolic and diastolic pressure, the lowering of the systolic index and heart
rate, and in increase in mechanical and electromechanical systoles, the amplitude
of the teeth R and T. The detected changes in the cardiovascular system are due
to the value of trained loads and their nonadequacy to the functional state of
myocardium.
PMID- 10687086
TI - [The effect of a cryoextract of the chorion on the cellular reaction of an
inflammatory focus].
AB - On the model of carrageenan-induced acute aseptic peritonitis in rats it is shown
that in inflammation on the background of administration of chorion's cryoextract
a marked inhibition of neutrophilic reaction and stimulation of macrophagic
fibroblastic one, and earlier ending of inflammation is observed, i.e.
cryoextract of chorion has an expressive anti-inflammatory action which is mainly
realized by inhibition of pathologic reactions and stimulation of protective ones
in the blood.
PMID- 10687087
TI - [Structural and functional changes to the lungs and the lipid metabolic status in
cardiogenic shock].
AB - The functional and structural manifestations of lipid metabolism disorders in the
lungs were studied in comparison with the changes of fatty acid composition of
lipids of pulmonary tissue, venous and arterial blood, expirated air condensate
and sweat during the development of cardiogenic shock in patients with myocardial
infarction. It has been established that the lungs accumulate neutral lipids and
lose phospholipids and polyunsaturated fatty acids. These changes are combined
with intracellular lesion of osmiophilic lamellated corpuscles and disturbance of
their excretion into alveolar cavities. At the same time the increase of
polyunsaturated fatty acids content in expirated air condensate and sweat of
patients is noted can be related to the elimination of the excess of these
substrates from intercellular space.
PMID- 10687088
TI - [The effect of internal and external irradiation on thyroid gland function in
experimental animals].
AB - We are investigated influence of different kinds of radiation (internal--131I,
external--gamma and roentgen irradiation) in equivalent doses (5 Gy) on the
thyroid function of experimental animals. Revealed distinctions in the dynamic
development of the function changes after action different types of radiation.
PMID- 10687089
TI - [Free-radical processes under different conditions of body oxygen allowance].
AB - Free radical processes (FRP) in mammalian organism are oxygen-depended. The
review is devoted to the analysis of pro- and antioxidant processes in mammalian
tissues under different oxygen supply conditions. There are described: sources of
free radicals; hyperproduction of FRP under hyperoxia and hyperbaria; the role of
free radicals in the adaptation to chronic hypoxia (high altitudes, barochamber,
chronic heart and lung diseases); production of active oxygen species during the
reoxygenation of preliminarily hypoxic tissues; FRP under intermittent hypoxic
training; role of FRP in the chemoreception of oxygen. The special attention is
paid to three main factors underlined the FR production in hypoxic conditions:
the speed of hypoxia increase, the degree of hypoxia and the time of hypoxic
exposure.
PMID- 10687090
TI - [Gene therapy: ethical aspects and problems of genetic safety].
AB - Gene therapy (GT) is based on the introduction of various genetic constructions
in the human organism. Rapid development of GT technologies and the increasing
tendency to apply them in therapy for certain human diseases has created a number
of ethical problems. These first and foremost concern direct intervention in the
genome of germline cells, which may change the genome of further generations.
According to current views, such manipulations are ethically unacceptable.
Introduction of genetic constructs in somatic cells with therapeutic purposes
(somatic GT) is considered permittable in principle but requires certain
procedures to ensure the genetic safety (causing no damage) of both the patient
and other people. The latter hazard is associated with a possibility of
uncontrolled spreading of viral (especially retroviral) constructions used in
many GT protocols. These and other ethical and genetic safety problems of modern
GT are discussed.
PMID- 10687091
TI - [Analysis of differences in the structure of ribosomal DNA from two sibling
species: Drosophila melanogaster and Drosophila simulans].
AB - Southern-blot hybridization studies have revealed structural differences within
the ribosomal DNA clusters of two sibling species, Drosophila melanogaster and
Drosophila simulans. The approach used was shown to be suitable for taxonomic
identification of the species examined.
PMID- 10687092
TI - [Conjugative transfer of a plasmid from Escherichia coli to various strains of
the order Actinomycetales].
AB - The conjugal transfer of autonomous and integrative plasmids from the donor
strain Escherichia coli S17-1 to strains of genera Actinomadura, Arthrobacter,
Kitasatoa, Micromonospora, Nocardia, Rhodococcus, Saccharopolyspora, and to 16
strains of the genus Streptomyces was demonstrated. The status of plasmids in
recipient strains and the stability of their inheritance were analyzed. Plasmids
constructed for strains of the genus Streptomyces were shown to function in a
large number of strains belonging to the order Actinomycetales. The well
developed system of Streptomyces vector molecules and cloned genes of antibiotic
biosynthesis allows their transfer to those microorganisms for which conventional
techniques of plasmid transfer by regenerated protoplast transformation or
electroporation have not been developed or are inefficient.
PMID- 10687093
TI - [Double crossing over: elementary events and the sequence of their occurrence].
AB - Analysis of the crossing over increment in the structurally normal chromosome of
Drosophila caused by a rearrangement in nonhomologous chromosome
(interchromosomal effect on crossing over, IEC) was carried out based on the
author's personal and literature data. The IEC in the left arm of chromosome 2
caused by inversions in chromosomes X and 3, as well as the IEC in X chromosome
caused by inversions in chromosomes 2 and 3, were examined. The IEC-induced
increment of crossing over results from the increase of the number of double
exchanges under the constant or reduced number of single exchanges. Tetrad
analysis showed that the given alternation of the crossing over processes could
occur only in the case of conversion of the tetrads with single exchanges into
the tetrads with double exchanges. In other words, the events leading to the
formation of double exchanges occur consecutively. The borders of the IEC-induced
double exchanges can be seen all over the chromosome body. However, the IEC
induced increase of chromosome recombination length occurs only in the proximal
region (in rare cases, in proximal and distal regions) of the chromosome arm.
This means that a double exchange is formed when the first event with predominant
location in the middle of the arm is supplemented with the second event
predominantly localized at the arm T end, most frequently in the proximal region.
The pattern of the IEC-induced double exchange formation can be satisfactorily
described in terms of the contact model of the crossing over. According to the
model, an elementary crossing-over event is the local contact between the
homologues. Neither single exchange nor a double-stranded DNA break can serve as
an elementary event in the process of any multiple exchange formation.
PMID- 10687094
TI - [Effect of inactivating various components of the signal pathways of the tumor
suppressor p53 on genomic stability].
AB - To evaluate the role of different p53-regulated signaling pathways in the control
of genomic integrity, we studied the frequency of changes in chromosome number
and structure of cells of the sublines of mouse primary embryonic fibroblasts
with the "knocked-out" genes for proteins p53, p21WAF, pRb, and p19ARF. Protein
p21WAF is transactivated by p53 and is responsible for the cell block in the G1
phase of the damaged cells; protein pRb is a target for p21WAF which controls the
G1-S-phase transition; and p19ARF protein is responsible for p53 activation in
cells with certain anomalies. Inactivation of either of the studied genes proved
to increase significantly the frequency of changes in the karyotype. However, the
resultant chromosome instability differed: the frequency of the chromosome
breaks, both spontaneous and induced with ethylmethane sulfonate (EMS), was in
cells with inactivated p53 and lowest in cells with inactivated pRb. These
distinctions were not caused by a different effect of various gene inactivation
on the cell cycle progression: in all sublines, the cell block in G1 was
abolished and the checkpoint function in G2 remained normal. However, the
induction of apoptosis in EMS-treated cells differed in the studied sublines. The
lowest number of apoptotic nuclei were determined in p53-/- cultures, whereas the
highest were in the Rb-/- cultures. It is apparent that the degree of genetic
instability is determined by a combined effect of apoptosis and abnormal
regulation of the cell-cycle checkpoints.
PMID- 10687095
TI - [Association of mutations in cytochrome b and NADH-dehydrogenase 5/6
mitochondrial DNA genes from the sable (Martes zibellina L.)].
AB - RFLP analysis of amplified genes for cytochrome b and NADP dehydrogenase 5/6 of
sable mtDNA was carried out. Polymorphism was recorded in the first and the
second fragment using six and four enzymes, respectively. This allowed us to
identify seven mtDNA haplotypes forming two clusters, A1-A3 and B1-C2. The
divergence between the clusters was 0.0112-0.0164. An association between
mutations of genes for cytochrome b and NADP dehydrogenase 5/6 was established.
This association can be explained by high mutability of the fragments containing
the associated mutations.
PMID- 10687096
TI - [Intrapopulation autosomal polymorphism in the common vole Microtus arvalis from
the Transcaucasian region].
AB - The broad autosomal polymorphism in form obscurus of common voles Microtus
arvalis from the Transcaucasian region that is associated with the variation of
subtelocentric chromosome pair 5, as well as the mechanism and evolutionary
significance of this polymorphism, are discussed. Based on the morphological
analysis of heterozygotes for chromosome pair 5 after differential G-, C-, and Ag
NOR-banding and on the measurements of homologues, the following conclusion has
been made. The occurrence of the acrocentric chromosome 5 is the result of a
double chromosomal rearrangement: a pericentric inversion and a duplication of
the chromosomal material. The mutation has been found throughout the entire
territory of Armenia. In spite of such a wide distribution, the mutation
frequency in populations is extremely low. Neither a definite pattern of
geographic distribution nor a clinal variation was found for this mutation. This
mutation is likely to occur independently in different M. arvalis populations and
is apparently neutral. Homozygotes for chromosome pair 5 are described for the
first time.
PMID- 10687097
TI - [Genetic-demographic processes in urban populations of the Ukraine in the 90's.
The marital structure of the Poltava population].
AB - Analysis of records of the marriages that were contracted in the city of Poltava
revealed an increase in outbreeding between 1960 and 1985 in the Poltava
population. This was expressed in increased ethnic diversity, proportion of
interethnic marriages, migration range, and the parent-offspring and average
marital distances, whereas the proportion of the indigenous ethnic group
(Ukrainians) decreased. By 1995, outbreeding decreased: the ethnic composition of
the population became more homogeneous (98% Slavic), the proportion of Ukrainians
and the frequency of monoethnic marriages increased, and the migration range
decreased. During the period studied, the population became more panmictic with
respect to ethnicity and birthplace, with the social and professional
subdivisions of the population remaining unchanged.
PMID- 10687098
TI - [Structure and diversity of the mitochondrial gene pool of the aboriginal
population of Tuva and Buriatia from restriction polymorphism data].
AB - The populations of Tuvinians (N = 36) and Buryats (N = 105) were characterized by
using the data on mitochondrial DNA (mtDNA) polymorphism. The gene pools of both
ethnic groups possessed the mtDNA types belonging to the four main haplogroups,
A, B, C, and D, found only in the indigenous populations of Asia and America. The
total frequencies of the A, B, C, and D haplogroups in Tuvinians and Buryats were
72.3% and 52.4%, respectively. These values, along with the frequency for Altai
populations (57.2%), were highest in the Asian populations studied, indicating
that the populations Southern and Eastern Siberia can be considered as ancestral
relatives to the ethnic groups of the New World. Analysis of the mtDNA region V
polymorphism showed the presence of 9-bp deletion and 4-bp insertion in both
populations with frequencies respectively of 13.9 and 5.56% in Tuvinians and 4.8
and 1.9% in Buryats. The frequency of the +AvaII/8249 variant was 11.1% in
Tuvinians and 3.81% in Buryats. Analysis of the association between the region V
deletion-insertion polymorphism and certain restriction haplogroups pointed to
repeated and independent emergence of the 4-bp insertion in Siberia.
PMID- 10687099
TI - [Polymorphism of exon 4 in the CANP-3 gene in patients with primary myopathies].
AB - The structures of the gene for calpain (CANP-3) and of the DMD gene were analyzed
in patients with primary myopathies [limb-girdle muscular distrophy (LGMD) and
Duchenne-Becker myodystrophy (DBM)] from various regions of Russia. Via
amplification of DNA isolated from the peripheral blood lymphocytes of 74
patients, extended deletions were found in 18 out of 55 patients with DBM. In
none of the 19 patients with LGMD, were extended deletions in the CANP-3 gene
found. In most patients with LGMD, the amplification of the promoter region and
exons 1, 2, 3, 4, 5, and 6 of the CANP-3 gene yielded a single product of
corresponding length, but in six patients (three sib pairs), amplification of
exon 4 of the CANP-3 gene yielded two products of different size. The following
single-strand conformation polymorphism (SSCP) analysis revealed a pronounced
polymorphism of exon 4 of the CANP-3 gene in 14 out of 19 patients with LGMD.
This structure of exon 4 of the CANP-3 gene was found neither in 16 patients with
DBM who had deletions in the DMD gene nor in 16 patients with DBM who had no
deletions in the DMD gene.
PMID- 10687100
TI - [Spontaneous mutants of Alteromonas espejiana, resistant to kanamycin and
bleomycin].
AB - An attempt was made to induce insertions in marine bacterium Alteromonas
espejiana Bal-31 (Ae) using the TnphoA transposon. The Ae mutants selected on a
kanamycin-containing medium after conjugation of the Ae with the transposon
donor, Escherichia coli SM10(pRt291), were resistant not only to kanamycin (Kn),
but also to bleomycin (Bm), and were sensitive to tetracycline. Although the
mutants were phenotypically similar to insertion mutants, the mutations appeared
to be spontaneous. The sensitivity of spontaneous Kmr Ae mutants selected at
various Km concentrations to Bm was investigated. The mutants selected at low Km
concentrations were resistant to Bm, whereas those selected at high Km
concentrations were sensitive to Bm. The possible mechanisms underlying the dual
resistance to Bm and aminoglycosides in bacteria are discussed.
PMID- 10687101
TI - [Prescription of cardiovascular drugs for non-authorized indications].
PMID- 10687102
TI - [Systematic treatment of acute myocardial infarction with primary angioplasty.
Early clinical and angiographic results and after 6 months].
AB - Starting in 1995, at our institution all patients with acute myocardial
infarction (AMI) who gave informed consent were treated by primary percutaneous
transluminal coronary angioplasty (PTCA) without limitations in entry criteria.
This report presents early and six-month clinical and angiographic results of the
720 patients (77% male, median age 64 years) treated by direct PTCA between
January 1, 1995 and July 31, 1998. On admission, 33% of patients were in Killip
class > 1, and 101 patients (14%) were in early cardiogenic shock. Optimal acute
angiographic success (TIMI grade 3 flow with residual stenosis < 30%) was
achieved in 683 patients (95%). Primary or unplanned stenting of infarct related
artery (IRA) for a suboptimal or poor angiographic result after primary PTCA was
performed in 454 patients (63%). The mean time from hospital arrival to
recanalization was 62 +/- 28 min. At 30 days, the mortality rate was 4.9% (1.8%
in Killip class < 4 patients and 24% in patients with cardiogenic shock). The
reinfarction rate was 1.2%. At 30 days, coronary angiography showed restenosis or
reocclusion of the IRA in 55 patients (8.9%). During the six-month follow-up (30
180 days), there were 11 deaths (1.5%) and 2 non-fatal reinfarctions (0.3%). At
six months, the IRA patency rate was 95%, while the mean ejection fraction
improvement in 422 patients with paired ventriculograms was 7%. Recurrent
ischemia occurred in 144 patients (20%) and resulted in 7 deaths, 11 non-fatal
reinfarctions and 126 repeat targeted vessel revascularization. CONCLUSIONS: The
major finding of our experience is that direct coronary angioplasty may result in
excellent early and late outcome in a population without limitations in entry
criteria. The low mortality and the few recurrent myocardial ischemic events are
connected with the high patency rate at 6 months. The extensive use of stents
improves the angiographic results and the clinical outcome.
PMID- 10687103
TI - Heart transplantation in ischemic heart disease when recipients are older than 55
years and donors older than 50.
AB - The purpose of this article is to analyze patients affected with ischemic
cardiomyopathy, older than 55 years, who have undergone heart transplantation. We
conducted a retrospective analysis comparing clinical course and outcome in
patients whose donor age was > or = 50 years (Group A) with patients who had
younger donor heart (Group B). Group A was composed of 25 patients, 55 to 68
years old (27.4% of the patients), 20 males and 5 females; Group B was composed
of 68 patients, 55 to 66 years old, 65 males and 3 females. Mean donor age in
Group A was 54.7 years old (range 51-61), while in Group B it was 29.5 years old
(range 9-49). Operative mortality was 16% (4 cases) and 12% in Group B (8 cases)
p = ns. Total mortality in Group A was 24%, or 6 cases: 2 graft failures, 1
infection, 1 neoplasm, 1 multiorgan failure, 1 ischemic heart disease; in Group B
it was 27%, or 18 cases: 2 cerebrovascular accidents, 4 graft failures, 3
infections, 5 neoplasms, 3 multiorgan failures, 1 acute rejection, p = ns.
Coronarography was performed in 51 patients, 14 in Group A (10 cases normal, 3
with irregularities, and 1 case with a critical stenosis of the circumflex
artery; 37 in Group B (32 cases were normal, 3 had irregularities and 2 had
critical stenosis in a coronary artery). In conclusion, we emphasize that
extending donor age in recipients older than 55 years of age does not determine a
higher risk and mortality.
PMID- 10687104
TI - Diagnosis and early surgical management of traumatic thoracic aortic disruption.
AB - OBJECTIVE: Traumatic rupture of the thoracic aorta is a major cause of death.
Survival greatly depends on early diagnosis, degree of injuries to other
districts and timing of repair. To address the controversial aspects of this
condition, we retrospectively reviewed our experience. METHODS: Between April
1984 and December 1998, 39 patients (31 males, 79%), with a mean age of 33 +/- 7
(range, 17 to 59 years), underwent surgical repair at our institution. Final
diagnosis of aortic disruption was achieved in 33 patients (85%) by aortogram,
and in 6 (15%) by transesophageal echocardiography (TEE) alone. Four patients
(8%) had a false negative chest X-ray on admission. Twenty-four patients (61.5%)
had additional major injuries to other districts (n = 4, cranial trauma; n = 13,
cranial trauma + pelvic fracture; n = 5, lesions to abdominal viscera; n = 2,
lesions to abdominal viscera + pelvic fracture). Surgical techniques included
simple aortic cross-clamping in 7 patients (18%), partial femoral-femoral bypass
in 17 (44%), and partial left heart bypass in 15 (38%). Two patients underwent
direct aortic suture (5%), whereas 37 (95%) had interposition of a vascular
graft. RESULTS: Three patients (8%) died after major hemorrhaging during the
early phases of our experience. Paraplegia occurred in 1 patient (2.5%) in the
single aortic cross-clamping group. There was no morbidity directly attributable
to the administration of heparin for cardiopulmonary bypass. CONCLUSION: Although
aortography is still the gold standard to achieve diagnosis, the use of TEE as a
method of detecting traumatic injury to the thoracic aorta appears feasible in
critical patients, advantageously saving time. With a meticulous surgical
approach and the use of an effective method for distal aortic perfusion during
repair, it is possible to achieve good outcomes.
PMID- 10687105
TI - The limitations of echocardiography in the overall diagnosis of the morphological
lesions associated with infective endocarditis: comparison of echocardiographic
and surgical findings.
AB - Echocardiography is commonly accepted as the method of choice for the non
invasive diagnosis of vegetations and other lesions associated with infective
endocarditis. To assess the accuracy of echocardiography in the overall diagnosis
of the morphological cardiac lesions we retrospectively analyzed and compared the
preoperative echocardiographic data with the surgical findings of 120 consecutive
cases operated for infective endocarditis. Transthoracic echocardiography (TTE)
was used in 60 cases (51 with native and 9 with prosthetic valves), both TTE and
transesophageal echocardiography (TEE) in 50 (26 with native and 24 with
prosthetic valves) and only TEE in 10 patients who underwent emergency surgery.
The echocardiographic diagnosis was correct in all the cases, but incomplete in
26 (16 with native and 10 with prosthetic valves). Most of the incomplete
diagnoses occurred regarding vegetations, perforations of the valvular leaflets
and perivalvular abscesses. There were no differences between aortic or mitral
valves (14/66 vs 11/60; p = ns), native or prosthetic (16/79 vs 10/37; p = ns),
TTE or TEE (13/60 vs 13/60; p = ns); however, TEE was performed in more complex
cases and in severely ill patients. In six of the incomplete diagnoses,
echocardiography preceded surgery by one week or more, and in six the mistakes
were not confirmed by the reviewer. In conclusion, our study suggests that an
echocardiographic diagnosis of endocarditis may be correct but sometimes
incomplete. In patients without prosthetic valves who have a technically-adequate
transthoracic echocardiogram, transesophageal echocardiography is not
indispensable but should be chosen from time to time. However, the patients with
endocarditis and no contraindication to the transesophageal procedure should
undergo both transesophageal and transthoracic echocardiography before surgery in
order to obtain as much and the most definite information possible. An
echocardiographic study should be repeated just before any surgical procedures in
patients with active endocarditis. Finally, it needs to be emphasized that the
training and clinical judgement of the operator performing the study are
important elements determining the results of echocardiographic study.
PMID- 10687106
TI - QT dispersion and early arrhythmic risk during acute myocardial infarction.
AB - BACKGROUND: QT dispersion (maximal minus minimal QT interval calculated on a
standard 12-lead electrocardiogram) has been suggested to reflect regional
variations of ventricular repolarization and to provide a substrate for reentry
ventricular arrhythmias. In this study we evaluate QT dispersion in patients with
acute myocardial infarction and assess its relation with early severe ventricular
arrhythmias. METHODS AND RESULTS: We studied 101 patients with acute myocardial
infarction and a control group of 97 healthy subjects. We determined QT and QTc
dispersion on the electrocardiograms performed 12 hours and 3 and 10 days after
the onset of symptoms in myocardial infarction patients and on the control group.
The average values of QT and QTc dispersion (measured hereafter in milliseconds,
ms) were as follows: 70.5 +/- 42.5-87 +/- 46.6 (after 12 hours), 66.5 +/- 37.8
76.9 +/- 43.5 (on day 3), 68.9 +/- 42-76.3 +/- 43.8 (on day 10) and 44 +/- 13.4
54.2 +/- 16.3 (in control group). We observed statistically significant
differences in QT and QTc dispersion between the electrocardiogram of normal
subjects and each of the three electrocardiograms performed on patients with
infarction (p < 0.0005, p < 0.005). We recorded a greater QT dispersion in
patients with anterior infarction with respect to those with inferior/lateral
infarction (79 +/- 38.6 vs 65.2 +/- 43.16, p < 0.05) and in patients with
ejection fraction < 45% (93.1 +/- 28.4 vs 68.3 +/- 34.1 p < 0.005). During the
first three days, QT dispersion did not differ in patients treated with
thrombolytic agents with respect to those who were untreated, while on day 10
untreated patients showed higher values (74.9 +/- 45.3 vs 60.5 +/- 37.7, p <
0.05). Creatine kinase peak level, sex and age of the patients did not influence
QT dispersion. Thirteen patients (12.8%) developed severe ventricular arrhythmias
within 72 hours after infarction: 8 patients (7.9%) had ventricular fibrillation
and 5 patients (4.9%) had sustained ventricular tachycardia. We found higher
early QT and QTc dispersion values in patients who developed severe ventricular
arrhythmias (108.8 +/- 63.2 and 125.8 +/- 68.5) with respect to patients who did
not (63.3 +/- 32.9 and 80.8 +/- 38.9, p < 0.0005, p < 0.0005). CONCLUSIONS: Our
data suggest that QT dispersion: 1) increases during acute myocardial infarction;
2) peaks in the early hours after symptom onset; 3) drops late after infarction
in patients treated with thrombolytic agents; 4) is associated with early severe
ventricular arrhythmias.
PMID- 10687107
TI - [Improvement of HF: initiative to increase awareness and improve the management
of patients with heart failure in Europe].
AB - Heart failure is a major healthcare problem, with possibly over 10 million
patients in Europe suffering from the syndrome. Its prevalence is increasing
partly because the proportion of elderly population is likewise increasing. The
guidelines on the diagnosis and treatment of heart failure have been published by
the European Society of Cardiology and represent a landmark for judging current
medical practice. Evidence suggests that heart failure is frequently
underdiagnosed and undertreated, and the majority of patients may not be
receiving appropriate care. Both primary healthcare physicians and hospital
cardiologists are responsible for proper diagnosis and appropriate treatment of
patients with heart failure. The "Improvement of HF" initiative has been
developed by an International Advisory Board to increase awareness and improve
the management of heart failure among primary healthcare physicians in Europe.
The study first investigates how primary healthcare physicians perceive heart
failure should be diagnosed and treated, and examines the availability of
required resources. Subsequently, primary healthcare physicians will be
interviewed to assess their actual practice by reviewing relevant case notes,
covering diagnosis and treatment. The program will consist of a research phase
and an educational phase. For the research phase, 10 regional centers (including
both urban and rural areas) in each of the 14 participating countries in Europe
will be identified, with each center randomly selecting 10 primary healthcare
physicians. Each physician will supply case notes of 9 of his/her patients with
diagnosed heart failure or at high risk of having heart failure. The results of
the survey would identify any need to change not only perceptions but clinical
practice in the diagnosis and treatment of heart failure and will be used to
organize an educational program. A further study is planned in order to assess
the impact of the initiative.
PMID- 10687108
TI - [Improvement of prognosis in idiopathic dilated cardiomyopathy: role of early
diagnosis and optimized medical treatment. Study Group on Heart Muscle Diseases].
AB - BACKGROUND: The aim of this study was to assess the extent to which a more
widespread use of new effective treatments for heart failure associated with
earlier detection of the disease may have contributed to enhancing the prognosis
of idiopathic dilated cardiomyopathy (IDC) patients over the past 20 years.
METHODS: Heart transplant-free survival curves were analyzed in 343 IDC patients,
prospectively enrolled from January 1, 1978 to June 30, 1997 in the Heart Muscle
Disease Registry of the Cardiology Department in Trieste (94 enrolled between
1978 and 1987, Group 1; 249 between 1988 and 1997, Group 2). At enrollment, 91
patients had no heart failure symptoms (NoHF), whereas the remaining 252 showed
HF of recent (HF < or = 6 months, n = 132) or non-recent (HF > 6 months, n = 120)
onset. RESULTS: In comparison to Group 1, Group 2 was treated more frequently
with ACE-inhibitors and beta-blockers (p < 0.0001) and showed a better long-term
survival (p = 0.0034), resulting from a reduction of death for refractory HF or
need for heart transplant (p = 0.011). Conversely, the risk of sudden death did
not significantly differ between the two groups. NoHF, HF > 6 months and HF < or
= 6 months groups were similarly treated with ACE-inhibitors and beta-blockers.
Long-term survival was better in patients without HF than in those with overt HF
(p = 0.0015). As compared to Group HF > 6 months, Group HF < or = 6 months had a
poorer one-year prognosis (p = 0.045), related to the presence of a subgroup of
patients with refractory HF and need for heart transplant, but showed a better
survival rate over the following years (p = 0.015). Over the two subsequent
decades of enrollment, a significant improvement in patient survival was observed
within Groups NoHF (p = 0.03) and HF > 6 months (p = 0.01), but not in Group HF <
or = 6 months. CONCLUSIONS: Over the past 20 years, the increasing use of ACE
inhibitors and beta-blockers in IDC was associated with a significant improvement
in long-term survival, resulting from a reduction in mortality for refractory
heart failure or need for heart transplant. In addition, early diagnosis may have
contributed significantly to enhancing the prognosis of IDC, since the benefits
of medical therapy were lower in patients identified and treated in advanced
stages of the disease. Moreover, early diagnosis was shown to be useful in
recognizing patients with recent onset of heart failure who are not responders to
aggressive medical treatments and urgently need heart transplant.
PMID- 10687109
TI - [Cardiovascular risk factors in Italy: an interpretation with reference to th
National Health Plan 1998-2000. Research Group of the Cardiovascular
Epidemiologic Observatory].
AB - The data submitted were collected throughout 1998 in 34 cardiology centers or
divisions within the Cardiovascular Epimediological Observatory (Osservatorio
Epidemiologico Cardiovascolare), in a general population sample of 3222 men and
3192 women aged 35 to 74 years. Each center screened 200 individuals (100 men and
100 women) randomly selected from the electoral rolls. The data constitute an
updated reference benchmark for the health status of the Italian population at
the end of the Nineties. It also represents a useful source of information for
attainment of the objectives pursued by the National Health Plan 1998-2000: a
healthier diet, increased physical activity and reduced smoking. The proportion
of hypertensives receiving adequate treatment and the high prevalence of
individuals with "undesirable" cholesterol levels are problems that should be
dealt with following the preventive actions indicated in the National Health Plan
for 1998-2000.
PMID- 10687110
TI - [Effectiveness of paroxetine in the treatment of refractory vasovagal syncope in
young patients].
AB - OBJECTIVES: The aim of the study was to assess whether the well-tolerated
serotonin re-uptake inhibitor paroxetine hydrochloride could prevent vasovagal
syncope in young patients resistant to or intolerant of previous traditional
therapies. BACKGROUND: Serotonergic mechanisms may play a major role in the
pathophysiology of neurocardiogenic syncope, and serotonin re-uptake inhibitors
have been recently reported to be effective in preventing episodes. METHODS:
Forty-one consecutive young patients (13 male and 28 female), aged less than
thirty years with recurrent syncope and positive head-up tilt test, and in whom
standard therapies with beta-blocking, vagolytic, negative inotropic or mineral
corticoid agents were ineffectual, poorly tolerated or contraindicated, randomly
received either paroxetine at 20 mg once a day or a placebo. A head-up tilt test
was then re-performed after one month of treatment, and the clinical effect was
noted over a mean follow-up of 27.1 +/- 6.6 months. RESULTS: The response rates
(negative tilt test) after one month of treatment were 57.1 versus 33.3% (p <
0.001) in the paroxetine and placebo groups, respectively. During follow-up,
spontaneous syncope was observed in 4 patients (19%) in the paroxetine group and
in 12 patients (60%) in the placebo group (p < 0.001). Only one patient (4.8%)
asked to be discontinued from the drug for severe recurrent headache.
CONCLUSIONS: Paroxetine significantly improved symptoms of young patients with
recurrent vasovagal syncope unresponsive to or intolerant of traditional
medications and was well tolerated by patients.
PMID- 10687111
TI - [Clinical course of pre- and post-natal isolated congenital atrioventricular
block diagnosed in utero].
AB - We evaluated the pre- and postnatal outcome of isolated atrioventricular (AV)
block detected during fetal life in order to identify factors that may affect the
natural history of this lesion and to assess prenatal therapy. Over the past
eight years, we consecutively evaluated 10 fetuses with complete AV block. The
mean gestational age at diagnosis was 25.3 weeks and the mean heart rate was 57
bpm; two fetuses were hydropic. During pregnancy, one fetus suddenly died, while
6 out of 9 fetuses had a mean reduction in heart rate of 17.8 bpm; 4 patients had
heart rate < 50 bpm. Five fetuses developed heart failure, which was severe in 2
cases and mild in 3. The mean gestational age at delivery was 31 weeks.
Dexamethasone was administered to the mothers during pregnancy in 4 cases without
modification of AV block and/or of heart rate, but in 3 out of 4 fetuses the
general condition remained stable in spite of the reduction in heart rate in two
of them. Sympathomimetic drugs were employed in 3 cases with an increase in fetal
heart rate, but maternal discomfort appeared in two cases. Three newborns died
during the first week of life, two of hydrops and one of persistent pulmonary
hypertension. Cardiac pacing was performed in 6/9 patients within the first 8
months of life and in 3 within the first 2 days. In conclusion, morbidity and
mortality are high when AV block is detected during fetal life. Negative
prognostic factors are hydrops and a heart rate < 50 bpm. Pre-term delivery to
enable cardiac pacing is probably the therapy of choice if gestational age is >
27-28 weeks. Sympathomimetic drugs are effective but are poorly tolerated by the
mothers. Dexamethasone has no effect on AV block and/or heart rate, but may
improve clinical tolerance of conduction disturbance.
PMID- 10687112
TI - [Clinical characteristics, familial distribution and preliminary genetic data in
9 different families with "Brugada's syndrome"].
AB - Clinical electrocardiographic evaluation and complete non-invasive assessment
including nuclear magnetic resonance (NMR) are reported for 7 subjects with
cardiac arrest (CA), 6 due to ventricular fibrillation (VF) and 1 to ventricular
tachycardia (VT). Two more subjects, one with and one without a family history of
non-resuscitated sudden death (NRSD), were included. All 9 subjects showed the
typical pattern of the Brugada's syndrome (BS), characterized by incomplete right
bundle branch block, ST T elevation in V1 V3. We globally evaluated 64 subjects
belonging to the 9 families examined, 5 of whom were identified in Bologna, 3 in
Florence and one in Parma. BS is characterized in the experience described in the
present paper by a family distribution of the ECG pattern in different members.
Furthermore, a family distribution of NRSD, even at a young age, was observed.
Electrocardiographic features were consistent with variable degrees and aspects
of the intraventricular conduction delay (ICD) and of the ST T elevation pattern.
NMR has been performed so far in 23 out of 64 members examined by echo, and was
normal in 17/23, with only 6 showing pathological aspects such as mild dilatation
of the right ventricle, reduced thickness of the right free wall, isolated
dilatation of the right ventricular infundibulum and other minor pathological
aspects. Preliminary genetic screening (GS), performed on 20 members of three
families, was negative for the typical genetic patterns of right ventricular
dysplasia (ARVD). In six families, GS is still ongoing. Genetic screening of
sodium channel pathology is in progress in the same families. In conclusion, BS
has been documented in the present paper as a hereditary syndrome, both for
clinical and ECG aspects, associated with CA due to VF, which required an AICD
implantation, at least in symptomatic subjects. There may exist a CONGENITAL form
of BS due to pathology of sodium channels, without a demonstrable structural
heart disease and an ACQUIRED form of BS secondary to an initial ARVD. From the
clinical point of view, a complete evaluation, including serial ECG,
pharmacological testing and programmed electrical stimulation of other subjects
in the families, may be important in preventing sudden death, mainly in
symptomatic subjects who always require an implantable cardioverter
defibrillator.
PMID- 10687113
TI - Relief of an early pulmonary pathway obstruction with stenting after modified
Fontan operation in an adult.
AB - The prognosis of Tricuspid Atresia, a rare congenital heart disease, has been
changed by surgery. The criteria for Fontan operation have been well established
in the literature and adult patients rarely fulfil these criteria; however, in
very selected cases Fontan operation can be performed also in adults. A 33 year
old woman with tricuspid atresia and previous palliation with classical right
Glenn and with left modified Blalock-Taussing, underwent modified Fontan
operation because increasing cyanosis and moderate exercise intolerance. Three
weeks after operation the patient was readmitted with severe heart failure
because of a tight obstruction at the anastomosis between right atrium and main
left pulmonary artery. The stenosis was treated with balloon and stenting
achieving large pathway. Our experience confirms that after a modified Fontan, if
cardiac failure occurs, an immediate full investigation have to be done.
PMID- 10687114
TI - Treatment of a native right coronary artery with the PercuSurge Guardwire
protection system during PTCA and stenting.
AB - Cardiac catheterization in a patient with recent-onset unstable angina
demonstrated a suboccluded dominant right coronary artery (RCA), with
angiographic evidence of a large thrombus load and a severe focal stenosis of the
left anterior descending (LAD) coronary artery. After abciximab, uneventful PTCA
and stenting of the LAD was performed. The thrombus containing lesion of RCA was
treated with balloon predilatation and stent deployment, and the whole procedure
was accomplished with protection of the distal vessel by means of PercuSurge.
This device was planned to avoid distal debris migration during percutaneous
interventions of saphenous bypass grafts. The system is designed to allow the
placement of a temporary occlusion device, a low-profile balloon, distal to the
lesion to be treated during the procedure. The occlusive balloon is kept inflated
during the treatment of the lesion. Before deflating the balloon and allowing
blood to reach the distal vessel, whenever it is necessary, the material proximal
to the balloon is aspirated through a monorail catheter. This aspiration removes
blood and thrombi proximal to the occlusive balloon from the treated coronary
artery. The case we present first reports the application of the device in a
large native coronary artery, with an optimal distal flow restoring and no
evidence of thrombus embolization. This type of protection of distal coronary
vessels towards micro- and macroembolization of thrombi is a promising system of
performing safer percutaneous interventions, even in acute ischemic syndromes.
PMID- 10687115
TI - Incessant ventricular tachycardia early after acute myocardial infarction:
efficacy of radiofrequency catheter ablation but not of optimal coronary
revascularization.
AB - Incessant ventricular tachycardia is an arrhythmia refractory to conventional
antiarrhythmic treatment. We describe the case of 55-year-old man who presented
incessant ventricular tachycardia in the early post-acute phase of myocardial
infarction. Optimal coronary revascularization was not effective, but
radiofrequency catheter ablation was able to eliminate the anatomic substrate and
clinical arrhythmic recurrence.
PMID- 10687116
TI - Cardiac tamponade: an unusual, fatal complication of infective endocarditis.
AB - Infective endocarditis still occurs in Western countries and so far, it has been
an important medical problem. The spectrum of infective endocarditis
complications may be extremely wide. We report two unusual cases of infective
endocarditis complicated with heart rupture and pericardial effusion. In one
case, the infective process spread from the aortic valve developing a sinus of
Valsalva aneurysm with subsequent aortic perforation. The perforation reached the
right auricular epicardial region with subsequent epicardial rupture and
hemopericardium. In the other patient, an infective process of the aortic cusps
induced the formation of multiple abscesses in the left ventricle and in the
right atrium. An annular abscess of the tricuspid valve was found. From the right
atrium, an infected fistula spread through the atrial wall and perforated the
epicardial surface of the right auricle. Aside from the rare occurrence of these
complications in patients affected with infective endocarditis, these cases are
of clinical interest because they raise the problem of the need of greater
sensitivity to the diagnosis of endocarditis and proper diagnostic approach.
PMID- 10687117
TI - [Proposed tools for quality assurance in echocardiography].
PMID- 10687118
TI - [Organization of pediatric cardiology in Italy. Cognitive survey by the Italian
Society of Pediatric Cardiology].
PMID- 10687120
TI - [Words and the specialty's pains].
PMID- 10687119
TI - [Cardiac ischemia (excluding AMI) and DRG classification system. Epidemiologic
approach].
PMID- 10687121
TI - [Etiologic diagnosis of dilated cardiomyopathy].
PMID- 10687122
TI - [Role, timing and cost-benefit analysis in non-invasive assessment after non
complicated myocardial infarction].
PMID- 10687123
TI - [Risk stratification in patients treated with non-cardiac major vascular
surgery].
PMID- 10687124
TI - [Neurogenic syncope in the elderly patient].
PMID- 10687125
TI - [The use of endothelin-1 receptor antagonists in cardiovascular diseases].
PMID- 10687126
TI - [What is the role of nitrates in the treatment of heart decompensation? A
rationale for their use].
PMID- 10687127
TI - [Orthostatic tachycardia syndrome. Update on etiology, diagnosis and treatment].
PMID- 10687128
TI - [Suboptimal exercise test in chronic heart decompensation: the six-minute walking
test].
PMID- 10687129
TI - [Arrhythmic complications in patients with heart decompensation: when and how to
treat].
PMID- 10687130
TI - [Risk identification and strategy for the prevention of sudden cardiac death
after myocardial infarction].
PMID- 10687131
TI - [Heart rupture in acute myocardial infarction: advantages of the use of Doppler
color echocardiography M-2D in coronary intensive care unit].
PMID- 10687132
TI - Cytotoxic T lymphocytes from humans with adenocarcinomas stimulated by native
MUC1 mucin and a mucin peptide mutated at a glycosylation site.
AB - MUC1 mucin peptides stimulated cytotoxic T lymphocytes (CTL) from humans with
adenocarcinomas. Peripheral blood mononuclear cells, tumor-draining lymph node
cells, or tumor-infiltrating lymphocytes were stimulated using mono-nuclear cells
from humans with adenocarcinomas of breast or ovary, respectively, using (a) a
native MUC1 mucin tandem repeat peptide of 20 amino acids (MUC1-mtr1) plus
recombinant human interleukin-2 (IL-2), (b) the mutated (T3N) MUC1-mtr1 plus IL
2, or (c) immobilized anti-CD3 plus IL-2, or (d) IL-2 alone. The CTL stimulated
by each of these four conditions were predominately CD4+. However, the CTL
stimulated by either the native MUC1-mtr1 or (T3N) MUC1-mtr1 showed 5-10 times
greater cytotoxicity of a breast cancer cell line that expresses MUC1 compared to
CTL stimulated by either anti-CD3 + IL-2 or IL-2 alone. Each incubation condition
generated CTL with different variable beta gene families of T-cell receptors,
implying an oligoclonal expansion of a limited CTL repertoire for each. Thus,
peptide-stimulated T cells showed expression of cytotoxic cells, which was not
induced by nonspecific (anti-CD3 or IL-2) stimulation.
PMID- 10687133
TI - Interleukin-4 enhances the in vitro precursor cell recruitment for tumor-specific
T lymphocytes in patients with glioblastoma.
AB - Previously the authors showed that interleukin-4 (IL-4), used in combination with
IL-2, increases the reduced proliferation rate of T cells of glioblastoma-bearing
patients after in vitro autologous immunization. In this report, they sought to
determine whether this effect is caused by a direct mitogenic effect of IL-4, or
rather by an indirect effect through an increased expression of the IL-2 receptor
subunits or an enhanced recruitment of responsive cells. Flow cytometric analysis
confirmed that the IL-2 receptor subunits are less expressed on circulating T
cells from patients with glioblastoma than on those from healthy donors. Because
no significant modification of the expression of the p55 and p75 subunits of the
IL-2 receptor is observed in cultures treated with both IL-2 and IL-4, the
reported enhanced proliferation rate cannot be attributed to an increased level
of IL-2 receptor expression. Limiting dilution assays, using autologous target
cell immunization, show that treatment with both cytokines (IL-2 plus IL-4)
significantly increases the number of recruitable precursor cells without
affecting their proliferation rate. These results indicate that IL-4 facilitates
an immune response against the autologous tumor cells in glioblastoma-bearing
patients by increasing the recruitable precursor T-cell frequency.
PMID- 10687134
TI - Recognition of shared melanoma antigens in association with major HLA-A alleles
by tumor infiltrating T lymphocytes from 123 patients with melanoma.
AB - A total of 123 tumor-infiltrating T lymphocyte (TIL) cultures established from
patients with HLA-A1, -A2, -A3, -A24, or -A31 metastatic melanoma in the Surgery
Branch, National Cancer Institute, were screened for recognition of shared
melanoma antigens including five melanosomal proteins (tyrosinase, MART-1/melan
A, gp100, TRP1, TRP2) as well as peptides derived from MAGE-1 and MAGE-3.
Examination of the specificity of these T cells indicated that 16% of HLA-A1 TIL,
57% of HLA-A2 TIL, 7% of HLA-A3 TIL, 13% of HLA-A24 TIL, and 27% of HLA-A31 TIL
recognized shared melanoma antigens restricted by major histocompatibility
complex class I. Melanosomal proteins were frequently recognized by these TIL,
and MART-1(27-35), gp100(154-162), gp100(209-217), and gp100(280-288) represent
highly immunogenic epitopes that were recognized by a high percentage of HLA-A2
restricted melanoma reactive TIL. Recognition of gp100 by HLA-A2 restricted TIL
significantly correlated with clinical response to adoptive immunotherapy with
TIL in 21 HLA-A2 melanoma patients (p = 0.024). Four HLA-A1, two HLA-A2, two HLA
A3, one HLA-A24, and two HLA-A31 restricted shared antigen-specific TIL did not
recognize the previously identified antigens tested in this study, and may be
useful for the identification of new melanoma antigens. The observation that TILs
isolated from patients with metastatic melanoma recognized melanosomal proteins
in the context of predominant HLA-A alleles implies that it may be possible to
develop immunotherapies for patients with melanoma expressing diverse HLA types.
PMID- 10687135
TI - Reduced recognition of metastatic melanoma cells by autologous MART-1 specific
CTL: relationship to TAP expression.
AB - Class I expression in context with T-cell receptor expression is crucial for
peptide presentation and induction of CD8+ cytotoxic T lymphocytes (CTL).
Presentation of class I bound peptides is dependent on transporter-associated
proteins (TAP) expression and function. Tumor infiltrating lymphocytes from a
patient with melanoma were isolated, expanded in vitro in the presence of
interleukin-2, and tested for cytotoxicity against HLA-A2 positive, MART-1
positive autologous tumor cells, an HLA-A2-positive, MART-1 positive melanoma
cell line (Mel-501), and HLA-A2-negative melanoma cells. Significant killing
occurred against both A2-positive cell lines (63% and 65%, respectively), but not
against the A2-negative line (18%) or A2-positive autologous tumor (1.5%). These
CTL preferentially recognized the MART-1 peptide F119, 27-35, and gp100 peptide
F125, 280-288, resulting in a 30% to 60% enhancement of lysis when autologous
tumor or major histocompatibility complex class I "empty" T2 cells were pulsed
with either peptide. To address whether the deficiency in autologous tumor
recognition might be related to a deficiency in Ag presentation, we screened for
the presence of TAP1 and TAP2 transcripts by polymerase chain reaction, Southern
blotting, and scanning densitometry using sequence-specific primers and probes.
Both TAP1 and TAP2 expression levels in the autologous tumor were minimal, yet
were upregulated 7- to 18-fold, respectively, by interferon-gamma. Despite this
increase, a similar increase in cytotoxicity did not occur. In short,
deficiencies in TAP presentation may have functional significance for tumor
escape from immunosurveillance and with respect to impending vaccine trials.
PMID- 10687136
TI - Tumorigenicity and immunogenicity of murine tumor cells expressing an MHC class
II molecule with a covalently bound antigenic peptide.
AB - The significance of CD4+ lymphocytes and major histocompatibility complex (MHC)
class II-restricted antigens in antitumor immunity has been demonstrated in
several animal models as well as in some human tumors. However, because of the
lack of known class II-restricted antigens, the participation of CD4+ cells in
antitumor responses has not been well characterized. Recent reports showed that
class II proteins covalently linked to an antigenic peptide could be constructed
and cells expressing these fusion proteins were recognized by specific TH cells.
The aim of this study was to determine the effect of the expression of a class II
peptide construct on the tumorigenicity and immunogenicity of transfected murine
tumor cells. We have constructed a gene for I-Ed beta chain covalently coupled to
the I-Ed-restricted TH cell determinant of sperm whale myoglobin (SWM132-145).
This class II fusion protein was recognized by a specific TH cell line on the
surface of COS-7 cells or BALB/c sarcoma cells. The sarcoma cells expressing the
MHC-peptide complex were rejected by immunocompetent BALB/c mice, and in vivo T
cell subset depletion experiments suggested the importance of CD4+ cells in the
rejection. Moreover, splenocytes from mice immunized with tumor cells expressing
the I-Ed-SWM complex showed specific peptide recognition in vitro. Such covalent
MHC-peptide complexes could prove useful in studies on the role of CD4+
lymphocytes in antitumor immune responses, and also in designing new, more
effective vaccine approaches to the immunotherapy of cancer, as class II
restricted tumor-associated antigens are identified for human cancers.
PMID- 10687137
TI - Dendritic cells generated from CD34+ progenitor cells with flt3 ligand, c-kit
ligand, GM-CSF, IL-4, and TNF-alpha are functional antigen-presenting cells
resembling mature monocyte-derived dendritic cells.
AB - Dendritic cells (DCs) are powerful antigen-presenting cells. Because DCs are rare
cells, methods to produce them in vitro are valuable ways to study their biologic
properties and to generate cells for immunotherapy. This study defines the
antigen-presenting properties of DCs generated in vitro from CD34+ cells of
patients with breast cancer. The combination of cytokines flt3 ligand + c-kit
ligand + granulocyte-macrophage colony-stimulating factor (GM-CSF) + interleukin
4 (IL-4) + tumor necrosis factor-alpha (TNF-alpha) was used to maximize the
output of mature DCs in the culture of CD34+ cells while minimizing the
production of monocytes. Cells grew and differentiated into DCs as measured by a
time-dependent upregulation of cell surface antigens major histocompatibility
complex class II, CD1a, CD80, CD86, CD40, and CD4, so that 40% +/- 9% (n = 6) of
cells in culture at day 15 were CD1a+CD14-. Markers were acquired in the same
sequence as on monocytes induced to differentiate with GM-CSF + IL-4.
Differentiation was marked by a time-dependent increase in allostimulatory
function, which, at its peak, was more potent than in cultures of DCs generated
from monocytes with GM-CSF + IL-4, but was comparable on a cell-to-cell basis to
that of mature monocytes cultured in flt3-ligand + c-kit-ligand + GM-CSF + IL-4 +
TNF-alpha. Both CD34+ cell-derived and monocyte-derived DCs were able to process
and to present tetanus toxoid and keyhole limpet hemocyanin to autologous T cells
and to present major histocompatibility class I-binding peptides to CD8+
cytotoxic T lymphocytes inducing interferon-gamma production. Altogether, these
results suggest that DCs generated from CD34+ cells of patients with breast
cancer with flt3 ligand, c-kit ligand, GM-CSF, IL-4, and TNF-alpha are competent
antigen-presenting cells, particularly for CD8+ cytotoxic T lymphocytes, and
resemble mature monocyte-derived DCs in the assays described here.
PMID- 10687138
TI - Generation of T-cell immunity to a murine melanoma using MART-1-engineered
dendritic cells.
AB - The murine melanoma B16 expresses the murine counterpart of the human MART
1/Melan-A (MART-1) antigen, sharing a 68.6% amino acid sequence identity. In this
study, mice were vaccinated with bone marrow-derived murine dendritic cells
genetically modified with a replication-incompetent adenoviral vector to express
the human MART-1 gene (AdVMART1). This treatment generated a protective response
to a lethal tumor challenge of unmodified murine B16 melanoma cells. The response
was mediated by major histocompatibility complex class I-restricted cytotoxic T
lymphocytes specific for MART-1 antigen, which produced high levels of interferon
gamma when reexposed to MART-1 in vitro and lysed targets in a calcium-dependent
mechanism suggestive of perforin/granzyme B lysis. MART-1 was presented by the
dendritic cells used for vaccination and not by epitopes cross-presented by host
antigen-presenting cells. In conclusion, dendritic cells genetically modified to
express the human MART-1 antigen generate potent murine MART-1-specific
protective responses to B16 melanoma.
PMID- 10687139
TI - Cervical cancer cells induce apoptosis of cytotoxic T lymphocytes.
AB - The goal of immunotherapy is to eliminate tumors by generating tumor-specific
cytotoxic T lymphocytes (CTLs) in patients or by adoptively transferring ex vivo
activated CTLs into patients. Clinical trials have shown that tumor-specific CTLs
often disappear before tumors are completely eliminated. In this study, the
authors show that CTLs specific for cervical tumor cells undergo apoptosis after
they are co-cultured with cervical tumor cells. The established cervical tumor
cell lines and cervical cancer tissues express CD95 (Fas/Apo-1) ligand. The tumor
cell-induced T-cell apoptosis can be blocked by an inhibitory anti-CD95 (APO
1/Fas) antibody, indicating that tumor cells induce apoptosis of CTLs through
CD95-CD95 ligand interaction. Addition of interleukin-2 (IL-2) and IL-7 into the
culture rescues the CTL from tumor cell-induced apoptosis. The rescued T cells
retain their full antitumor cytotoxicity. These data suggest that human cervical
tumor cells might actively down-regulate a cellular immune response by inducing
apoptosis of specific T cells during immunotherapy. Local use of IL-2 and IL-7 as
adjuvants may promote survival of the CTL and, thus, enhance the efficacy of
immunotherapy.
PMID- 10687140
TI - Enhanced transgene expression and effective in vivo antitumor immune responses
initiated by dendritic progenitors transfected with a nonviral T7 vector
expressing a model tumor antigen.
AB - Genetic education of dendritic cells (DCs) with tumor-associated antigens is an
encouraging development in DC-mediated tumor immunotherapy. In this study, to
increase the transgene expression by DCs using nonviral vectors, a cytoplasmic T7
vector (T7T7/T7Luc) was used to transfect bone marrow-derived DCs with the
firefly luciferase gene as a reporter and as a model tumor antigen. As a result,
the luciferase activity of T7T7/T7Luc-transfected DCs was more than four times
greater than that of DCs transfected with pCMVLuc, a commonly used nonviral
vector. Furthermore, the luciferase activity was increased three times more when
dendritic progenitor cells rather than mature DCs were transfected. In vivo tumor
studies showed that T7T7/T7Luc-transfected DCs, which express high levels of
luciferase (model tumor antigen), stimulated a stronger immune response than did
pCMVLuc-transfected DCs, which express relatively low levels of luciferase, as
indicated by the cytotoxic T lymphocyte assay. T7T7/T7Luc transfected DCs, when
injected into recipient mice, evoked an antigen-specific immune response that can
effectively eradicate implanted metastasis and prevent new tumor development by
murine melanoma cells genetically modified to express luciferase. Therefore, the
T7 system is a powerful nonviral vector that can be used to genetically educate
DCs with tumor-associated antigens for tumor immunotherapy.
PMID- 10687141
TI - Immunomodulatory dendritic cells generated from nonfractionated bulk peripheral
blood mononuclear cell cultures induce growth of cytotoxic T cells against renal
cell carcinoma.
AB - Dendritic cells (DCs) loaded with tumor antigens have the potential to become a
powerful tool for clinical cancer treatment. Recently, the authors showed that a
tumor-specific immune response can be elicited in culture via stimulation with
autologous renal tumor lysate (Tuly)-loaded DCs that were generated from cytokine
cultured adherent peripheral blood mononuclear cells (PBMCs). Here, the authors
show that immunomodulatory DCs can be generated directly from nonfractionated
bulk PBMC cultures. Kinetic studies of DC differentiation and maturation in PBMC
cultures were performed by monitoring the acquisition of DC-associated molecules
using fluorescence-activated cell sorting analysis to determine the percentage of
positive immunostained cells and the mean relative linear fluorescence intensity
(MRLFI). Compared with conventional adherent CD14+ cultures, which have mostly
natural killer, T, and B cells removed before cytokine culture, bulk PBMC
cultures exhibited an early loss of CD14+ cells (day 0 = 78.8%, day 2 = 29.6%
versus day 0 = 74%, day 2 = 75%) with an increase in yield of mature DCs (DC19-
CD83+) (day 5 = 17%, day 6 = 21%, day 7 = 22% versus day 5 = 11%, day 6 = 15%,
day 7 = 23%). Although a comparable percentage of DCs expressing CD86+ (B7-2),
CD40+, and HLA-DR+ were detected in both cultures, higher expression levels were
detected in DCs derived from bulk culture (CD86 = MRLFI 3665.1 versus 2662.1 on
day 6; CD40 = MRLFI 1786 versus 681.2 on day 6; HLA-DR = MRLFI 6018.2 versus
3444.9 on day 2). Cytokines involved in DC maturation were determined by
polymerase chain reaction demonstrating interleukin-6 (IL-6), IL-12, interferon
gamma, granulocyte-macrophage colony-stimulating factor, and tumor necrosis
factor-alpha mRNA expression by bulk culture cells during the entire 9-day
culture period. This same cytokine mRNA profile was not found in the conventional
adherent DC culture. Autologous renal Tuly (30 micrograms protein/10(7) PBMCs)
enhanced human leukocyte antigen expression by DCs (class I = 7367.6 versus
4085.4 MRFLI; class II = 8277.2 versus 6175.7 MRFLI) and upregulated cytokine
mRNAs levels. Concurrently, CD3+ CD56-, CD3+ CD25+, and CD3+ TCR+ cell
populations increased and cytotoxicity against autologous renal cell carcinoma
tumor target was induced. Specific cytotoxicity was augmented when cultures were
boosted continuously with IL-2 (20 U/mL biological response modifier program)
plus Tuly stimulation. These results suggest that nonadherent PBMCs may
participate in enhancing DC maturation. Besides the simplicity of this culture
technique, bulk DC cultures potentially may be used with the same efficiency as
conventional purified DCs. Furthermore, bulk culture-derived DCs may be used
directly in vivo as a tumor vaccine, or for further ex vivo expansion of co
cultured cytotoxic T cells to be used for adoptive immunotherapy.
PMID- 10687142
TI - Cytokine-inducing activity and antitumor effect of a liposome-incorporated
interferon-gamma-inducing molecule derived from OK-432, a streptococcal
preparation.
AB - An interferon-gamma (IFN-gamma)-inducing molecule (OK-PSA) has been purified from
OK-432 by an affinity chromatographic technique performed on cyanogen bromide
activated Sepharose 4B-bound TS-2 monoclonal antibody, which neutralizes IFN
gamma-inducing activity of OK-432. OK-PSA has striking anti-tumor activity in
vivo and in vitro. In the current study, the liposomes were used to improve the
delivery of the agent (OK-PSA) to effector cells and to increase the therapeutic
effect. Significantly less OK-PSA encapsulated into liposomes (Lipo-OK-PSA) than
OK-PSA alone (1/100 or less of OK-PSA alone) was required to induce IFN-gamma,
tumor necrosis factor-alpha (TNF-alpha), TNF-beta, interleukin-1 beta (IL-1
beta), natural killer, and lymphokine-activated killer activities by human
peripheral blood mononuclear cells and mouse spleen cells. Furthermore, higher
levels of these activities were detected in peripheral blood mononuclear cells
and mouse spleen cells treated with Lipo-OK-PSA than in those treated with OK
PSA. All of these activities induced by Lipo-OK-PSA were almost completely
neutralized by anti-asialo-GM1 antibody and complement (p < 0.001). In in vivo
experiments, Lipo-OK-PSA elicited striking anti-tumor activity on syngeneic Meth
A tumor-bearing and colon 26-bearing BALB/c mice and on salivary gland tumor
bearing nude mice far better than did OK-PSA. Furthermore, high levels of natural
killer and lymphokine-activated killer activities and a significant increase in
the number of cells positive for asialo-GM1, IFN-gamma, TNF-alpha, or IL-1 beta
were detected in the spleen cells derived from the animals given Lipo-OK-PSA
compared with those given saline. These findings clearly indicate that OK-PSA
plays an important role in the anti-tumor efficiency of OK-432, and that, for the
most part, liposome encapsulation of this molecule markedly accelerates its
effect mediated by asialo-GM1-positive cells (mainly natural killer cells).
PMID- 10687143
TI - c-erbB-2 and episialin challenge host immune response by HLA class I expression
in human non-small-cell lung cancer.
AB - The role of major histocompatibility complex expression in cancer prognosis and
pathogenesis is contradictory. The aim of the current study was to compare the
expression of HLA class I molecules and of oncoproteins that may be sources of
peptides presented by HLA class I antigens in non-small-cell lung cancer. For
this purpose, the expression of HLA class I antigen and TAP-1 molecule (a
transporter in the antigen-processing 1 transport protein) were studied with
epidermal growth factor, receptor; c-erbB-2; episialin; wild-type and mutant p53;
bcl-2 oncoprotein expression; and angiogenic factor expression (vascular
endothelial growth factor and thymidine phosphorylase). The degree of lymphocytic
stromal infiltration and of platelet-endothelial cell adhesion molecule
expressing lymphocytes was also studied. A strong association of c-erbB-2 and
MUC1 (episialin) expression with HLA class I expression was observed (p = 0.005
and 0.009, respectively). Intense CD31-positive lymphocytic infiltration was also
more frequent in HLA class I-positive cases (p = 0.05). Although there was no
association of HLA class I expression with survival, loss of the HLA class I
expression in MUC1 or c-erbB-2 overexpressing cases conferred a poorer clinical
outcome (p = 0.04). Both c-erbB-2 and MUC1 are well-known targets of T-cell
mediated cytotoxicity and cell-cell or cell-matrix adhesion-regulating proteins.
The authors provide evidence that the sequence of cell adhesion-disrupting
oncoprotein expression, HLA class I induction, and enhanced epitope presentation
followed by lymphocytic response is an important pathogenetic three-step sequence
of events that define, in part, the clinical outcome in non-small-cell lung
cancer.
PMID- 10687144
TI - Vitamin D3 treatment to diminish the levels of immune suppressive CD34+ cells
increases the effectiveness of adoptive immunotherapy.
AB - Tumor growth can increase the number of immature bone marrow-derived CD34+ cells
that exhibit natural suppressor (NS) activity toward T-cell function. Using a
metastatic Lewis lung carcinoma (LLC-LN7) tumor model, these CD34+ NS cells were
shown to be present within the s.c. primary tumor tissue, but their levels
declined after treatment with the inducer of myeloid cell differentiation,
vitamin D3. Therefore, studies determined whether vitamin D3 treatment to
diminish the CD34+ NS cell levels in LLC-LN7-bearing mice would enhance (a)
intratumoral immune reactivity and (b) the antitumor activity of adoptive therapy
consisting of tumor-reactive lymph node cells. The results showed that vitamin D3
treatment alone increased the intratumoral CD8+ cell content and the activity of
the intratumoral infiltrate, as detected by production of interferon-gamma and
expression of the p55 IL-2 receptor. Although vitamin D3 treatment had no effect
on the size of the primary tumor, it lessened the extent of tumor metastasis.
Treating mice with the combination of vitamin D3 and adoptive immunotherapy
significantly reduced metastasis in mice with established tumors, and reduced
both metastasis and locoregional recurrence after surgical excision of the
primary tumor. These studies demonstrate that vitamin D3 treatment increases
intratumoral T-cell immune reactivity, and that coupling vitamin D3 treatment to
diminish levels of CD34+ NS cells with adoptive immunotherapy enhances the
effectiveness of the adoptively transferred tumor-reactive lymph node cells at
limiting both metastasis and locoregional tumor recurrence.
PMID- 10687145
TI - Antitumor vaccination using a major histocompatibility complex (MHC) class I
restricted pseudopeptide with reduced peptide bond.
AB - Synthetic peptides have raised a considerable interest in the fields of vaccines
and immunotherapy. The authors previously introduced modifications into the
peptide backbone of the H-2Kd-restricted epitope CW3. One of these
pseudopeptides, C7, bound to Kd with an affinity identical to the parent peptide
and was recognized by T cells specific for the parent peptide. The authors now
show that this analog has an increased resistance to trypsin and displays an
extended half-life in serum. The authors further tested its immunogenicity both
in vitro and in vivo and found that cytotoxic T lymphocytes (CTL) induced against
the peptide analog recognize the parent peptide. Moreover, analysis of T-cell
receptor rearrangements by Immunoscope software revealed that C7-induced CTL
display the hallmarks of the response against the parental epitope CW3.
Administration of the pseudopeptide into DBA/2 mice induces a protective immune
response against a lethal challenge with tumor cells expressing the parent
peptide. Therefore, modifications in the backbone of antigenic peptides can
decrease protease susceptibility while preserving immunogenicity. Such peptide
analogues may therefore prove useful for the development of new therapeutic tools
aimed at eradicating pathogens or tumors.
PMID- 10687146
TI - Delivery of cytokines by liposomes: hematopoietic and immunomodulatory activity
of interleukin-2 encapsulated in conventional liposomes and in long-circulating
liposomes.
AB - Although liposomal delivery of interleukin-2 (IL-2) and other cytokines improves
their pharmacokinetics and biologic activity in vivo, there are no comparative
functional studies of various liposomal formulations as cytokine carriers. In the
present investigation, recombinant human IL-2 was encapsulated in two
formulations of large (mean diameter 0.75-1.5 microns) multilamellar vesicles
(MLV, referred to as conventional liposomes) or in small (mean diameter, 60 nm),
unilamellar, long-circulating liposomes (referred to as sterically stabilized
liposomes, SSL). The biologic activity of the liposomal formulations and of free
IL-2 was tested in parallel in vitro and in mice. The main observations were as
follows: (a) All the liposomal IL-2 (Lip-IL-2) formulations were more efficient
than soluble IL-2 in stimulating spleen cell proliferation and lymphokine
activated killer (LAK) cell activation in vitro, particularly at low cytokine
doses (1-100 CU/mL). (b) After i.v. injection, the circulation time of MLV-IL-2
and SSL-IL-2 was 7 and 17 times greater, respectively, than that of soluble IL-2.
(c) In comparison with IL-2, all Lip-IL-2 formulations caused a marked increase
in the leukocyte levels in blood, spleen, and peritoneal exudate, especially in
those of myeloid origin (neutrophils, eosinophils, immature granulocytes, and
macrophages). (d) Although SSL-IL-2 exhibited the longest circulation time, MLV
IL-2 was more potent in elevating leukocyte levels and in triggering LAK cell
activity in vivo. (e) The route of Lip-IL-2 administration greatly affected the
immunomodulatory activity in the various compartments. (f) MLV-IL-2 proved to be
a much more efficient immunoadjuvant than free IL-2 for influenza subunit
vaccines as well as for tumor cell vaccines. These findings lend support to our
previous studies in which we demonstrated the superior immunomodulatory activity
of liposomal IL-2, and suggest that cytokine pharmacokinetics, biodistribution,
and pharmacodynamics are markedly influence both by liposomal formulation and
route of administration.
PMID- 10687147
TI - Phase I study of single, escalating doses of a superantigen-antibody fusion
protein (PNU-214565) in patients with advanced colorectal or pancreatic
carcinoma.
AB - To develop a T-cell-based therapy for carcinomas, the superantigen staphylococcal
enterotoxin A (SEA) was supplied with tumor specificity by means of a recombinant
fusion of the Fab fragment of the monoclonal antibody C242 recognizing human
colorectal (CRC) and pancreatic carcinomas (PC). Using this Fab-SEA fusion
protein (PNU-214565), potent cytotoxicity by activation of T cells can be
obtained in the targeted area. Twenty-one patients with CRC and 3 with PC were
treated with single, escalating doses of PNU-214565 to establish the maximum
tolerated dose (MTD) and to define toxicities. The doses ranged from 0.01 ng/kg
to 4.0 ng/kg with three patients at each dose level, except for the dose of 1.5
ng/kg with which six patients were treated because of dose-limiting toxicity.
Adverse events (AE) were transient: 13 patients experienced mild to moderate
fever. In one patient, a grade 3 fever was followed by a grade 2 hypotension.
Other mild or moderate AEs were fatigue, nausea, vomiting, diarrhea, and
abdominal pain. No significant hematological toxicity occurred. Immune activation
was highly variable with strong activity in peripheral blood seen only in two
patients at the dosage level 1.5 ng/kg. They showed pronounced elevations of
interleukin-2 (IL-2), IL-6, tumor necrosis factor-alpha, and interferon-gamma, 3
5 hours after the start of infusion. In one patient, IL-2 and IL-6 increased
substantially (2,925 U/mL and 32,000 U/mL) concomitantly with grade 3 fever and
transient grade 2 neutropenia, grade 2 lymphopenia, and grade 2 monocytopenia. In
conclusion, a single 3-hour infusion of PNU-214565 could be safely administered
up to 4 ng/kg. MTD was not determined. Instead, a repeat-dose trial was initiated
starting at 0.5 ng/kg, considered safe in this trial, with the objective of
defining the MTD.
PMID- 10687148
TI - Posttransplant adoptive immunotherapy with activated natural killer cells in
patients with metastatic breast cancer.
AB - Relapse after high-dose chemotherapy is the main cause of therapeutic failure in
patients with metastatic breast cancer. Adoptive immunotherapy with interleukin-2
(IL-2) plus activated natural killer cells may eliminate residual disease without
excessive toxicity. The authors sought to determine if immunotherapy immediately
after transplantation would affect engraftment and the toxicity associated with
transplantation. Fifteen consecutive patients with metastatic breast cancer were
allocated to three cohorts. Cohort 1 (five patients) received high-dose
cyclophosphamide, thiotepa, and carboplatin (CTCb) followed by peripheral blood
stem cell infusion and granulocyte colony-stimulating factor at 10 micrograms/kg.
Cohort 2 (five patients) received in addition rhIL-2 (2 x 10(6) IU/m2/day) for 4
days intravenously via continuous infusion after peripheral blood stem cell
infusion. In cohort 3 (five patients), peripheral blood stem cell transplant was
followed by infusion of autologous activated NK cells and rhIL-2 (2 x 10(6)
IU/m2/day) for 4 days (via continuous intravenous infusion). Generation of
activated NK cells was possible in all patients in cohort 3. All patients has
successful engraftment. Median time to absolute neutrophil count more than 0.5 x
10(9)/L was 8 days (range, 8 to 11 days) in cohort 1, 9 days (range, 7 to 11
days) in cohort 2, and 9 days (range, 8 to 9 days) in cohort 3. Median time until
the platelet count was more than 20 x 10(9)/L was 14 days (range, 9 to 22 days)
in cohort 1, 11 days (range, 6 to 14 days) in cohort 2, and 12 days (range, 11 to
21 days) in cohort 3. All patients developed neutropenic fevers, but the overall
toxicity associated with the infusion of IL-2 (cohort 2) or IL-2 plus activated
NK cells (cohort 3) did not differ from that observed in cohort 1. Complete
responses were achieved in one patient in cohort 1, in two patients in cohort 2,
and in one patient in cohort 3. In conclusion, post-transplant adoptive
immunotherapy with activated NK cells plus IL-2 is feasible, well tolerated, and
does not adversely affect engraftment.
PMID- 10687149
TI - Phase II study of combined immunotherapy, chemotherapy, and radiotherapy in the
postoperative treatment of advanced non-small-cell lung cancer.
AB - The association of adoptive immunotherapy (AI) and radiotherapy has been shown to
be effective in the control of residual intrathoracic disease, while having no
systemic advantages, in patients operated on for locally advanced non-small-cell
lung cancer (NSCLC). The potential synergy of coupling immunotherapy and
chemotherapy has been emphasized in several tumors including NSCLC. The aim of
this work was to determine the feasibility and activity of a combined therapeutic
program, including AI, chemotherapy, and radiotherapy in patients who had
undergone incomplete resections for NSCLC. In a phase II trial, 13 patients
received the combined treatment. AI was given from week 4 after surgery until
week 8. Concurrent chemo-(cisplatin and etoposide)-radiotherapy (60 Gy) was given
from week 9 to week 14. Twenty eligible patients received chemoradiotherapy only
and were used as a non-randomized concomitant group for merely descriptive
purposes. At 9-month follow-up, 10 of the 13 patients had progression of disease
and the study was stopped. Progression-free survival and survival were similar to
those of the chemoradiotherapy group. The present study showed that the sequence
of immunotherapy followed by chemotherapy is not effective as adjuvant treatment
in patients operated on for stage III NSCLC, at least when used according to the
adopted schedule.
PMID- 10687151
TI - Microwave facilities for welding thermoplastic composites and preliminary
results.
AB - The wide range of applications of microwave technology in manufacturing
industries has been well documented (NRC, 1994; Thuery, 1992). In this paper, a
new way of joining fibre reinforced thermoplastic composites with or without
primers is presented. The microwave facility used is also discussed. The effect
of power input and cycle time on the heat affected zone (HAZ) is detailed
together with the underlying principles of test piece material interactions with
the electromagnetic field. The process of autogenous joining of 33% by weight of
random glass fibre reinforced Nylon 66, polystyrene (PS) and low density
polyethylene (LDPE) as well as 23.3% by weight of carbon fibre reinforced PS
thermoplastic composites is discussed together with developments using filler
materials, or primers in the heterogenous joining mode. The weldability
dependence on the dielectric loss tangent of these materials at elevated
temperatures is also described.
PMID- 10687150
TI - Dendritic cells loaded with MART-1 peptide or infected with adenoviral construct
are functionally equivalent in the induction of tumor-specific cytotoxic T
lymphocyte responses in patients with melanoma.
AB - Immunization with tumor-specific-associated antigen--pulsed dendritic cells has
proved to be efficacious in various animal models and is being evaluated for the
treatment of cancer in humans. Use of dendritic cells pulsed with specific
peptides or transfected with tumor-associated antigen genes has been a focused
area of investigation for inducing potent tumor and viral immune responses. In
this study, the authors demonstrate transgene expression, including the lacZ and
MART-1 genes, in dendritic cells infected with adenoviral constructs. These
transiently transduced dendritic cells, derived from melanoma patients' monocytes
cultured with granulocyte-macrophage colony-stimulating factor and interleukin-4,
express the transgene and can stimulate patients' CD8+ T cells to elicit an
antitumor immune response comparable to dendritic cells loaded with a defined
peptide. These cytotoxic T lymphocytes were able to recognize both known and
unknown tumor-associated antigen epitopes and exhibited cytolytic activity
against HLA-matched tumor cells expressing the antigen. The ability to induce
tumor-specific cytotoxic T lymphocytes in vitro using gene-modified dendritic
cells that transiently express tumor-associated antigens demonstrates the
potential use of these antigen-presenting cells for developing in vivo cancer
vaccines.
PMID- 10687152
TI - Switch mode power supply for microwave heating based on the Boucherot effect.
AB - This paper describes a new self-resonating switch-mode power-supply for driving
CW magnetrons, based on the Boucherot effect. A detailed circuit analysis is
given and its performance is evaluated for an 800 W/2450 MHz magnetron, whilst
work at high power driving a magnetron up to 40 kW is reported. A comparison of
the supply with the conventional power-supply used in microwave ovens is made and
the principal features of the new design are found to be: low energy dissipation
under short-circuit conditions, low ripple current and voltage waveforms that
result in more precise control in the range 20-100% of rated power, high
efficiencies and small size and weight.
PMID- 10687153
TI - Microwave enhanced ion exchange of cationic and anionic clays.
AB - The ion exchange reactions of both cationic clays (e.g. montmorillonites) and of
layered double hydroxides ("anionic clays") are greatly accelerated when carried
out under conditions of microwave heating. The observations appear general, and
the new methodology should be of considerable importance in many aspects of clay
science.
PMID- 10687154
TI - Temperature and weight loss profiles of model cakes baked in the microwave oven.
AB - Model cake systems were formulated with wheat and rice starches at hydration
levels of 112.5% and 137.5% (flour weight basis) and baked in a microwave oven at
power levels of 80% and 100%. Temperature profiles and weight loss profiles of
the cakes baked in the microwave oven were compared with those of the cakes baked
conventionally. One cake was baked at a time, and three replications of each
treatment were used. Center and edge temperatures of microwave cakes increased
significantly with increasing moisture content of the batter and oven power.
Weight loss of the cakes was dependent on oven power, starch type and hydration
levels. Cakes baked in the microwave oven had greater weight loss than the cakes
baked in convection mode. Wheat starch cakes had greater volumes than rice starch
cakes. Rice starch cakes were more tender than wheat starch cakes.
PMID- 10687155
TI - Variable frequency microwave heating of food.
AB - Industrial microwave food processing is universally based on single frequency
microwave sources. With the emergence of variable frequency microwave ovens, it
is possible to exploit the frequency dependence of a food's permittivity and/or
choice of heating frequency, for example as a new route to achieving targeted
heating. Variable frequency heating procedures are developed to overcome the
geometry of a roughly spherical foodstuff dominating the heating pattern when
heated in fixed frequency applicators. Target mean temperatures of 55, 75 and 90
degrees C within 2 minutes and without physical damage were set; means of 54.5 +/
4.1, 75.1 +/- 4.7 and 87.6 +/- 3.5 degrees C respectively were achieved within
the time constraint and with no major physical damage, based on combining 8
discrete frequencies between 2.4 and 6.2 GHz.
PMID- 10687156
TI - Enzyme inactivation analyses for industrial blanching applications employing 2450
Mhz monomode microwave cavities.
AB - Browning reactions in fruits and vegetables are recognized as a serious problem
for the European food industry, particularly for the mushroom sector. The major
enzyme responsible for the browning reaction is polyphenoloxidase (PPO). In this
paper considerable reduction has been achieved in both the time and temperature
required for complete microwave enzyme inactivation compared to conventional hot
water treatments, which can be translated into both increased benefits and
enhanced quality products for the food industry. Furthermore, the short exposure
time required for complete inactivation of aqueous solutions of PPO irradiated
with microwaves within monomode cavities is very important to reduce the browning
rate of mushroom extracts, and could lead to a much greater product profitability
when treating whole processed mushrooms.
PMID- 10687157
TI - Exercise test in detecting anomalous behaviour of blood pressure in patients
successfully operated on for coarctation of the aorta.
AB - Twenty-eight patients operated with success for isolated coarctation of the aorta
(i.e. with normal blood pressure and upper/lower limb gradient < or = 20 mmHg at
rest) underwent exercise testing to evaluate blood pressure and upper/lower limb
pressure gradient during exercise. At maximum effort: 57% (16/28) of the patients
were hypertensive and 43% (12/28) of patients increased upper/lower limb gradient
over 35 mmHg. No significant correlation was found between the age at surgery
(before or after 3 years of age) and maximal systolic blood pressure on exercise
and maximal pressure gradient on exercise. The 12 patients with an exercise
pressure gradient > 35 mmHg underwent digital angiography or magnetic resonance
of the aorta. In 7 cases a mild residual narrowing was found (5 with mild
transverse aortic arch hypoplasia, 2 with a mild residual coarctation). In 5
cases no residual narrowing was present. Many factors are thought to be involved
in the anomalous behaviour of blood pressure during effort: in some cases
anatomic factors, as residual narrowings of the aorta, in other cases functional
factors, as increased forearm vascular reactivity, altered baroceptor function,
different reactivity and structure of the pre- and post-stenotic aorta, etc., in
other cases finally, both factors, anatomic and functional. We conclude that the
exercise testing provides the best information on blood pressure modifications
during activity and it allows to us to identify those patients which, because of
exercise-induced hypertension, remain at risk of premature cardiovascular
disease, also after a successful operation. However, when hypertension is found
during effort, a strenous physical activity should be avoided and
antihypertensive treatment may be required. So the cardiovascular risk due to
hypertension can be reduced in the long term follow-up. Corrective surgery for
coarctation of the aorta, introduced in 1944, has completely modified the natural
history of the disease. Nowadays the operative risk is very low for isolated
coarctation and the great majority of the patients is asymptomatic after surgical
repair. Nevertheless, their life expectancy is substantially shortened, if
compared with the survival curve of a normal population. The vascular and
cardiovascular accidents, usually related to residual systemic hypertension, are
the most common cause of this. Some studies in the literature have shown that
many patients with normal blood pressure and no or little residual upper/lower
limb pressure gradient at rest, may develop an anomalous blood pressure response
e and/or a high upper/lower limb pressure gradient during exercise. We have
studied by exercise test a group of patients successfully operated on for
isolated coarctation of the aorta to evaluate the behaviour of the systolic blood
pressure and the upper/lower limb pressure gradient during exercise. The aim was
to recognize the patients who, inspite of very good operative result, remain at
cardiovascular risk in the long-term follow-up.
PMID- 10687158
TI - [Celiac disease and lymphoma].
AB - Celiac disease (CD) has been acknowledge as being responsible for numerous
secondary pathologies, in particular autoimmune and neoplastic diseases. Whether
CD is more prevalent in patients with non-Hodgkin's lymphoma (NHL) than in the
normal population is not known. Accordingly, we carried out a study of 86
patients hospitalized in the Section of Oncology, Haematology and Internal
Medicine of the Department of Medical, Oncological and Radiological Sciences of
the University of Modena and Reggio Emilia and who, between 1988 and 1995 had
been diagnosed as affected by NHL. On diagnosis, and before the beginning of
antitumour therapy, all the patients were tested for antigliadin (AGA IgA and
IgG) and antiendomysium (EMA) antibodies together with total class IgA antibody
levels. Our findings showed that none of the 86 patients had an IgA deficit,
while one tested positive for AGA IgA (43.9% v.n. < 7.5). The same patient also
tested positive for EMA. The extremely high sensitivity and specificity of the
AGA IgA and EMA led us to conclude that the patient was affected by CD, although
his early death precluded confirmation by biopsy. The presence of one celiac
patient among 86 NHL patients examined at the onset of the disease would suggest
that CD is not infrequent in NHL. The numbers involved in our study are
insufficient for statistical purposes, and we are therefore awaiting the results
of a SIGEP multi-centre study into the connection between CD and lymphomas.
PMID- 10687159
TI - Scintigraphic evaluation of gastroesophageal reflux in newborns.
AB - OBJECTIVES: This study was carried out to verify whether during neonatal stage
gastroesophageal scintigraphy, may be useful not only to diagnose
gastroesophageal reflux (GER), but also to detect pulmonary aspiration, at times
responsible for respiratory symptoms frequently associated with GER. PATIENTS AND
METHODS: Gastroesophageal scintigraphy was performed on 50 newborns admitted to
NICU of Brindisi in the last two years who presented symptoms as cyanosis,
apnoea, bradycardia, laringeal stridor, wheezing, not related to respiratory or
cardiac problems, but suspected to be clinical suggestive symptoms of
"pathological" GER. After administration of 99mTC mixed with the usual meal
formula, we obtained a recording period of 60-90 minutes and a later recording at
4 and 24 hours to document radioactive material in lungs. RESULTS: Scintigraphy
showed GER in 40/50 cases and despite frequent observation of respiratory
symptoms (39/40 cases) in these newborns never radiation in pulmonary fields.
CONCLUSIONS: Our results could indicate that scintigraphy, noninvasive and low in
radiation, may be considered effective and reliable to diagnose GER in newborns.
The absence of radiation in pulmonary fields could indicate that respiratory
symptoms frequently associated with GER could depend on involuntary mechanism of
vagal type and not on pulmonary aspiration.
PMID- 10687160
TI - Study on 480 hospitalized febrile children: evaluation of the septic risk and
results of the antibiotic and corticosteroid combined therapy.
AB - The febrile child, previously healthy, represents a frequent diagnosis and
management problem for pediatricians who work in private offices and those in
hospital emergency departments. We are specifically interested in the
identification, for the febrile child with septic risk, of severity parameters
permitting to assess the likelihood of a serious bacterial infection. In the
retrospective study we present, carried out on children admitted for febrile
illness, two factors were mainly evaluated: 1. identification of the septic risk
on the basis of some laboratory and clinical parameters; 2. effectiveness of an
early antibiotic plus corticosteroid treatment in a sub-group of children with
septic risk. The parameters we considered have been the degree of temperature
upon admission, the clinical appearance and the C-reactive protein (C-RP) values.
A significant correlation resulted for levels of temperature over 39 degrees C,
toxic-appearing child and very positive C-RP values. We have defined this
condition as a "threatening" fever requiring an immediate hospitalization in
order to administer appropriate blood tests and cultures, and also, according to
our rationale, to start an early antibiotic plus corticosteroid therapy (within 6
12 hours from the disease onset).
PMID- 10687161
TI - [Use of mini-laparoscopy in intraoperative diagnosis of contralateral inguinal
hernia in children].
AB - Laparoscopy has been considered by some Workers an useful means of diagnosing
patent processus vaginalis in children. This technique is effective in evaluating
patency of contralateral internal inguinal ring and requires only five minutes of
additional operative time to elective inguinal herniorrhaphy. The Authors report
their experience with fifty-six children to whom this procedure was offered.
Their age ranged from three to ten years--mean 6.5 years-. Congenital unilateral
hernia was right-sided in eighteen and left-sided in thirty-eight patients.
Overall, the contralateral processus vaginalis was patent in 44.6%, with 27.7%
and 52.2% patency on the nonclinical right and left sides, respectively. Low
abdominal pressure-insufflation with CO2 to a pressure of 4 mmHg and shortened
operative time have permitted to avoid endotracheal intubation. We confirm great
utility of laparoscopic examination in determining the need for contralateral
inguinal exploration in pediatric patients.
PMID- 10687162
TI - [Evaluation of diosmectite in acute diarrhea in children].
AB - The aim of this case-control study, was to estimate clinical effects, safety and
parents' assessment of Diosmectite, in acute infantile diarrhoea. Thirty-five
children aged 0-5 years, with acute diarrhoea from at least 5 days received
alternatively oral rehydration solution (ORS) and Diosmectite (3 g/day for 3 days
in children aged under 3 years and 6 g/day for 3 days in children aged over 3
years) (16 cases) or ORS only (19 cases). At discharge, parents' opinion
concerning satisfaction for treatment received was evaluated through a
questionnaire. Differences in the amount of liquid intake, weigh recovery,
resolution of fever, resolution of vomiting and number of loose stools in the
first 48 hours of hospitalization were not significant. Diosmectite was well
tolerated and no major side effects were found. Parents' satisfaction for therapy
resulted higher in the treated group than in the control group, even if
differences were not significant. Treatment with ORS and Diosmectite allowed to
shorten the mean duration of hospitalization by 0.4 days/children in the
treatment group compared to the control group. Further studies with more cases
and with higher does of the drug are necessary to confirm our results.
PMID- 10687163
TI - [Acute gouty arthritis in adolescents with renal transplants].
AB - Hyperuricemia is a common metabolic abnormality in subjects with renal
transplantation: in fact in transplanted adults receiving immunosuppressive and
diuretic drugs the frequency of hyperuricemia varied from 30 to 84% according to
treatment. Conversely, the gout is an uncommon eventuality, representing less
than 10%; predisposing factors are impaired renal function and older age. In the
younger patients with renal transplantation hyperuricemia is also frequent, but
the gout doesn't considered a possible complication in paediatric age. We
reported our observation of 5 patients (3 males and 2 females), 13-18 years old
who developed gout 2-84 months after renal transplantation. All the patients were
receiving cyclosporine, 4 even with prednisone and azathioprine. Two patients
were treated with furosemide because hypertension. The average of uric acid serum
levels in the post transplantation follow-up was 7 +/- 2 mg/dl; at the moment of
gout attack the uric acid serum levels raised to 12 +/- 1 mg/dl. The arthritis
diagnosis were made by clinical, laboratory and instrumental data (Rx and US). In
the most severe cases, uricasi therapy resolved clinical picture. The analysis of
immunosuppressive and diuretic treatment, renal function and dietary uses induces
us to think that the gout episode may be the result of many concomitant factors,
in adolescents with renal transplant.
PMID- 10687164
TI - [Giant posterolateral congenital extra-trigonal diverticula of the bladder: an
uncommon nosologic entity].
AB - The Authors, on the basis of their observation of two cases of giant
posterolateral congenital extratrigonal diverticula of the bladder
(D.G.P.P.L.E.), identify it as a nosological entity apart in the widest category
of bladder's diverticula, which implies a peculiar diagnostic and therapeutic
attitude.
PMID- 10687165
TI - [Femoral hernia in childhood: a rare entity].
AB - The Authors present 4 cases of femoral hernia treated in their pediatric surgery
department during the last 11 years. Childhood femoral hernia is rare and often
missed clinically because of difficulty in eliciting their clinical signs. During
an operation for inguinal hernia it is essential to think of femoral hernia when
a non obliterated processus vaginalis is not found.
PMID- 10687166
TI - [Report of case of Prader-Willi syndrome].
AB - We reported a case of Prader-Willi Syndrome. The simple chromosomic mapping is
negative. The obesity and polifagye is not present (2 years old). The ipotony is
improving, this case belongs to a possible light case.
PMID- 10687167
TI - [Effect of the NMDA receptor antagonist on parameters of delayed visual
differentiation and rearrangement of the impulse activity of neurons in visual
and prefrontal cortices in monkeys].
AB - With the aid of a multichannel leads the unit activity was recorded in the 17th
and 8th cortical fields along with registering behavioural data in Rhesus
monkeys. Multi-factor variance analysis revealed that the 2-amino-5-phospho
valeric acid (APV) effect involved a significant worsening of the monkeys'
behavioural characteristics: duration of the short-term memory shortened (2-4
fold), motor reactions' time increased, and the changes of cognitive
characteristics were always followed by significant rearrangements of the unit
activity in the above areas. The data obtained suggest that these cognitive
dysfunctions are due to a desynchronisation of unit activity in different areas
of the cortex including the neuronal assemblies maintaining the short-term memory
mechanisms associated with the glutamatergic structures.
PMID- 10687168
TI - [Effect of the unilateral activation of brain hemispheres on visceral pain
sensitivity in BALB/c mice].
AB - A hemispheric asymmetry of the visceral pain sensitivity control was revealed in
the BALB/c mice: animals with the left hemisphere inactivation did not differ
from sham-operated control mice in respect to the pain response parameters. A
right hemisphere inactivation reduced or suppressed the pain response. This
suggests that the right hemisphere domineers in the visceral pain control.
PMID- 10687169
TI - [Effect of the preparation baliz-2 on the integrative brain activity and biogenic
amine metabolism in rats under stress].
AB - Effects of balis-2 on exploratory activity in the open field and elevated plus
maze, attention to sensory stimuli of different modalities, elaboration and
retention of conditioned reflexes with food reinforcement, were studied in rats
under stress. Prolonged treatment of rats with balis-2 seems to normalise
integrative activity and metabolism of serotonine and dopamine in the animal
brain.
PMID- 10687170
TI - [Application of the simplified method of optic recording for mapping focuses of
the neuronal activity in the somatosensory cortex of the white rats].
AB - In rats, a differential signal was used for evoking an optical image in the
barrel-field zone which represented a difference between cortical images during
the control and the stimulation periods. After a subtraction of averaged
sequences of frames, an image of spots reflecting a probable location of
activated groups of neurones was obtained. Natural low frequency stimulation of
vibrissae is supposed to be the most effective. The method of intrinsic optical
activity imaging can be applied for preliminary mapping of cortical zones.
PMID- 10687171
TI - [Vascular reactivity and thrombus formation during postischemic reperfusion].
AB - Reactivity, thrombogeneity, and thromboresistance of the rat mesentery
microvessels were studied in postischemic reperfusion of the intestine, the
brain, an extremity. Irrespective of ischemia localisation, an augmentation of
the microvessels reactivity and reduction of their thromboresistance, were found.
The microvessels thrombogeneity was depended on the ischemia localisation: an
augmentation of the thrombogenity occurred in arterioles whereas it was reduced
in venules following the brain and intestine reperfusion. A possible mechanism of
the phenomenon may involve a deficiency of the nitric oxide synthesis.
PMID- 10687172
TI - [Dependence of the pump function of the isolated rat heart on the functional
activity of sigma receptors during reperfusion].
AB - Pre-treatment of the sigma-receptor with the sigma-receptor agonist (+)-SKF
10.047 improved the reperfusion recovery of cardiac pump function. The sigma
receptor activation, among other effects, prevented the reperfusion contracture,
increased pressure in the left ventricle, and improved survival of cardiomyocytes
after ischemia/reperfusion. Pre-treatment with the sigma-receptor antagonist DuP
734 augmented the reperfusion systolic dysfunction of the myocardium and
prevented postischemic contractures and cardiac cell lesions. Activation of the
cardiac sigma-receptor seems to prompt an augmentation of tolerance to the
reperfusion damage.
PMID- 10687173
TI - [Dependence of the protective effect of the elevated sodium level on the type of
oxidative substrate in the isolated heart during "calcium paradox"].
AB - Isolated guinea pig heart were perfused with the Tyrode solution followed in 15
min. by a 10-min. Ca(2+)-free solution with subsequent return to the normal
Ca(2+)-containing Tyrode solution. Sarcolemma damage was measured by myoglobin
release. The perfusion resulted in damage of the myocardium cells. The data
obtained show that elevation of the extracellular pressure during reperfusion
with the Ca(2+)-containing medium is more important than the absolute value of
the osmotic pressure.
PMID- 10687174
TI - [Effect of the sciatic nerve blockade on the function of the contralateral motor
center in the rat gastrocnemius muscle].
AB - When the rat spinal motor centre was activated by fixing the animal in a supine
posture, the motor units of intact gastrocnemius muscle fired more frequently in
the high-frequency range. Under conditions of the ischiatic nerve blockade, a
shift to an increase in the background firing frequency of the motor units
related to intact gastrocnemius muscle seems to be related to increased
motoneurone excitability occurring because of the contralateral denervation.
PMID- 10687175
TI - [Effect of modification of the structure of interleukin-1beta on its
physiological activity].
AB - Modification of the structure of recombinant human IL-1 beta: deletion of the
amino acids serine, asparagine, and asparagic acid in position 52-54 in mutant
delta SND, led to major changes in its functional activity. Significant reduction
of the main IL-1 beta activities: concomitant, pyrogenic and corticotropic ones
in the mutant delta SND, suggests the latter to be a partial agonist of IL-1
beta. Nevertheless the reduction in certain parameters of the humoral immune
response in mice following administration of the delta SND preparation suggests
that, when manifesting its immunomodulatory properties, the delta SND acts as a
partial antagonist of the IL-1 beta.
PMID- 10687176
TI - [Changes in secretion of sex steroid hormones during stress in rats with various
brain excitability].
AB - A stress procedure decreased the plasma progesterone faster in highly excitable
rats than in the less excitable those. The decrease in gonadal and adrenal
progesterone was still obvious in 24 hours in both groups of rats but more
obvious in the former group in respect to the progesterone level. The data
obtained may help to understand individual ability to respond to a stress in a
different way depending on functional condition of the hypothalamo-pituitary
adrenal axis.
PMID- 10687177
TI - [Characteristics of responses of the sympatho-adrenal system to various types of
cooling].
AB - Fast cooling involving the dynamic activity of the skin cold receptors seems to
establish a condition for changes in catecholamine concentration at a lesser
decrease of body temperature as compared with slow cooling.
PMID- 10687178
TI - [Effect of tobacco smoke on the level of estrogens and DNA in the rat uterus].
AB - Tobacco smoke induced no changes in the rat uterus weight or in oestrus cycle but
decreased estradiol (E2) concentration in the uterus tissue and increased and
later decreased the proliferation index and percentage of the cells in the S
phase. The data obtained suggest a phasic character of changes in the
reproductive system under the effect of tobacco smoke and corroborate the concept
of the role of smoking in the shifting the type of hormonal carcinogenesis from
promotional to genotoxic one.
PMID- 10687179
TI - [Dynamics of oxyhemoglobin, lactate, and pyruvate in plasma in connection with
the woman menstrual cycle].
AB - Levels of lactate, piruvate, oxy- and carbohaemoglobin were shown to change
regularly during women's menstrual cycle reflecting changes in metabolism in
respect to forming and destroying of the ovum.
PMID- 10687180
TI - [Effect of dimedrol on the regulation by histamine of the pacemaker activity of
the cat ureter].
AB - A certain concentration of Dimedrol (0.5 x 10(-6) mol/l) turned out to be capable
of neutralising the histamine regulation of the slow-wave activity. The histamine
H1-receptors were shown to modulate the cat general pace-maker's activity as well
as the Na+ mechanism of the slow wave genesis.
PMID- 10687181
TI - [Neurophysiological correlates of delayed visual differentiation in monkeys:
effect of location of the NMDA-receptor intracortical blockade].
AB - A multi-factor variance analysis revealed that the 2-amino-5-phosphonovalerian
acid (APV) effect was manifested in monkeys by a decrease in the number of
correct responses entailing a two-fold shortening of the short-term information
storage, as well as by an augmentation of the motor responses' time. The correct
responses' probability depended on the APV diffusion localisation in the cortex
whereas the motor responses' time did not depend on it. The APV effect was
accompanied by a desynchronisation of the unit activity in fields 46 and 17.
Neurophysiological correlates of cognitive functions, are discussed.
PMID- 10687182
TI - [Pharmacologic analysis of the subunit composition of AMPA-receptors in the
hippocampal neurons].
AB - Subunit composition and abundance of flip version of different AMPA receptor
subunits were studied in neurons acutely isolated from hippocampal area CA1 and
dentate gyrus. Whole cell recordings were made to record kainate unduced
currents. Presence of GluR2 in the receptor complex led to significant decrease
of selective channel blocker IEM-1460 potency. Flip versions of AMPA receptor
subunits were discriminated on the basis of their sensitivity to cyclothiazide.
Principal cell AMPA receptors in both areas were characterized by low sensitivity
to IEM-1460 while AMPA receptors of nonprinciple cells exhibited high or
intermediate sensitivity to IEM-1460. We observed significantly larger
potentiating effect of cyclothiazide on principal cells. Our data indicate that
there is a correlation between low sensitivity to IEM-1460 and high sensitivity
to cyclothiazide among AMPA receptors of different cells. Principal cells in both
regions possess more GluR2 subunits in their AMPA receptor complexes and more
abundant flip versions of their subunits in comparison with nonprincipal cells.
This correlation is obviously related to functional pecularities of different
neurons.
PMID- 10687183
TI - [Current concepts of involvement of glutamate in ischemic damage of the brain
tissue].
AB - Glutamate neurotoxicity cannot be considered the only reason for neuronal damage.
Other neurotransmitters and molecular messengers like nitric oxide, may be
involved in the toxic effect of glutamate. Different conditions in focal and
global ischemia, stage of the ischemic damage evolution, the degree of ischemia,
and activation of glutamate receptors, should also be taken into consideration
when assessing a neurological outcome.
PMID- 10687184
TI - [Blood pressure increase in foster mothers in ISIAH and Wistar rats: effect of
reciprocal cross-fostering].
AB - Maternal arterial blood pressure (ABP) of hypertensive (ISIAH) and normotensive
(Wistar) rats rearing their natural litter or litter of opposite strain, was
assessed when the pups were 1.5-, 3- and 4-month old and compared with the ABP of
these rats prior to their mating. The ABP was increased in both breeds of rat
strains for either cross-fostered or infostered pups. No ABP changes were
observed in control rats.
PMID- 10687185
TI - [Regional difference in endothelium-dependent vascular responses upon the flow
rate elevation].
AB - In anaesthetised rabbits, femoral artery manifested a maximal reserve capacity in
its vasodilatory response to the flow speed acceleration. In order of the
capacity diminishing, this artery is followed by renal artery, abdominal aorta,
celiacus tube, common carotid artery. The endothelium-dependent flow-induced
response is important for restricting the flow's linear speed.
PMID- 10687186
TI - [Changes in hypoxic resistance and conditional avoidance reflex during hypobaric
adaptation on the "flatland" and in mountains].
AB - White rats--males with mass 200-250 g were exposed ipobaroadaptation (rise on
12,000 m with an exposition 5 minutes) with periodic testing them on gipocsition
stability. After shaping in the result of gipobaroadaptation stressostability,
that it was judged in 2-3 times enlarging of reserve time, rats produced
conditional reflexes at active avoid (CRAA) as on plain area (760 m) so in high
mountainous (2500 m). It is observed that gipobaroadaptation increases
gipocsition stability and accelerates the CRAA shaping on plain area and in
mountains. The maximum effect of gipocsition stahility increasing, CRAA
consolidation and perfecting of efferention synthesis at high-mountainous
gipobaroadaptation rats is more significant, thah at "flat." gipobaroadaptation
has important protective significance for function of a brain, decreasing its
sensibility to lock of oxygen and fixing maximum adaptive responses.
PMID- 10687187
TI - [Morphofunctional changes in the placenta and in the hypophyseal-adrenal system
during low intensity infrared radiation in rats].
AB - Morphofunctional conditions of hypophysealadrenal axis and placenta following
hypoxis hypoxia and an infrared treatment, were studied in rats. The data
obtained involved high levels of the DNA, RNA, and lipidogenesis. Probable
mechanisms of structural changes are discussed.
PMID- 10687188
TI - [Immune responses in C57BL/6J mice with the inverted pattern of behavior during
social conflict].
AB - Inversion of aggressive behaviour into a submissive one led to immunosuppression
in C57BL/6J mice as well as in those mice which did not change their behaviour,
whereas inversion of submissive behaviour into aggressive one resulted in
immunostimulation. A possibility to influence immune response changing the brain
neurochemical pattern by reversing behaviour under conditions of a social
conflict, is discussed.
PMID- 10687189
TI - [Study of the chemoreception in mollusca].
AB - Recording of the mollusc osphardium nerve activity revealed the osphardium
sensitivity to hyperosmotic pressure, sodium chloride, and aminoacidosis. The
osphardium was found to detect quality of the water where the animals were kept.
Pont snail osphradium preserves ancestors' multisensority which unites perception
of different chemical and physical signals. Patch-clamp method revealed membrane
currents in certain ganglia and receptor cells which are sensitive to Na+ and L
aspartate increase in the solution around the osphardium. Inward components of
these currents are, probably, of the sodium and/or calcium nature, whereas the
outward components--of the potassium one.
PMID- 10687190
TI - [Seasonal changes in the function of mechanosensitive receptors in the rat skin].
AB - The effect of circannual rhythms on functional properties of the rat skin tactile
receptors and nocireceptors, was studied. The effect proved to be quite
significant for the cutaneous receptors threshold stimuli and for the parameters
of their responses: the latency and AP duration. These changes seem to be
determined by hormonal mechanisms.
PMID- 10687191
TI - [Ca(2+) level in the animal blood and their cold resistance].
AB - Administration of small doses of the EDTA decreased by 15-20% the Ca2+ contentn
in the blood plasma of rabbits and rats. The decrease coincided with an abrupt
stimulation of the thermoregulation system of cooled animals. Restoration of the
Ca2+ content in circulating blood coincided in time with repeated suppression of
the system's functions. The findings corroborate the theory of a key role of the
Ca2+ in sensitivity of the homoiothermal organism to cold and substantiates the
method of restoring physiological functions in deep hypothermia without rewarming
the body.
PMID- 10687192
TI - [Myoelectrical activity in the stomach during ulcerogenic exposure in rabbits].
AB - Stomach myoelectrical activity changed the slow wave frequency and spike
discharges under the effect of experimental injury in rabbits. High-amplitude
fluctuations named the "injury potentials" appeared. Bensohexonium prevented the
changes as well as ulceration. Metacin combined with proserin accelerated healing
of the ulcer and the rate of stomach myoelectrical activity.
PMID- 10687193
TI - [Effect of protein deficiency in the female rat diet during pregnancy and
lactation on the activity of the membrane and soluble forms of digestive enzymes
in the offspring small intestine].
AB - Protein deficiency in female rats diet during pregnancy and lactation resulted in
deceleration of induction of sucrase both forms in the jejunum and ileum; in
acceleration of induction of the maltase membrane from in the jejunum; and in
suppression of the lactase membrane form in the ileum; in earlier forming of the
adult-type distribution of activity of the membrane form of intestinal alkaline
phosphatase and in a decrease in activity of the enzyme soluble form. The
findings are corroborated by a suppression of activities of the membrane and
soluble forms of the small intestine digestive enzymes in 30-day old rat pups fed
with a control (adequate) ration starting 21 days after the birth.
PMID- 10687194
TI - [Activity of amino- and dipeptidases in the epithelial and subepithelial layers
of the small intestine in rats of various age subjected immobilization stress].
AB - Peptidase systems of all the layers of the jejunum and ileum proved to be most
sensitive to stress in young rats, whereas in mature and old rats the peptidases'
activity was enhanced, particularly in subepithelial layers of the ileum and
jejunum. This may be regarded as an adaptive-compensatory response to probable
existence of unsplit low-molecular peptides in the subepithelial space due to an
augmentation of proteins catabolism and their inflow via stress-damaged membranes
of enterocytes.
PMID- 10687195
TI - [Effect of strophanthin on the absorption of sodium and short chain fatty acids
from the sheep rumen].
AB - In vivo, intraruminal strophantin administration suppressed the sodium absorption
by up to 50% in the sheep reticulo-rumen. Absorption of the shortchain fatty
acids was not affected. The findings suggest absence of a combined transport of
sodium and short-chain fatty acids' anions in basic and lateral membranes of the
reticulo-rumen apithelium in sheep.
PMID- 10687196
TI - [Educational-research-practical association "Outpatient therapy" (results and
perspectives)].
PMID- 10687197
TI - [Prospective trial of 40-59-year-old males with angina pectoris and essential
hypertension (results of 30-35-year prospective studies)].
AB - AIM: To investigate remote prognosis for patients with coronary heart disease and
essential hypertension with consideration of the initial total serum cholesterol
(TSC) level. MATERIALS AND METHODS: Throughout 30-35 years 103 male patients aged
40-59 years with angina pectoris and essential hypertension were examined
(repeated evaluation of protein and lipid spectrum, normal resting and two-step
exercise ECG). At the entry, the patients had no history of myocardial infarction
(MI), cerebral thrombosis, heart failure, discirculatory encephalopathy. Causes
of death were verified by the data of autopsy (70.3%) and registry office's
records. Adequate data were obtained on 93 of 103 patients (90.3%). RESULTS: By
the end of the trial 89 of 93 patients died. 78 (87.6%) of them died of MI or
stroke. 44 deceased from the subgroup with low TSC level lived, on the average,
65.9 +/- 1.3 years, while 45 deceased from the subgroup with high TSC lived 67.9
+/- 1.4 years, i.e. 2 years longer. The worst life prognosis was for patients who
developed cancer. They lived 60.5 +/- 5.1 years, i.e. 7.5 years less than the
rest of the deceased. In the subgroup with low TSC level there were 5 times more
deceased due to cancer than in the subgroup with high TSC level. CONCLUSION:
Patients of middle and old age with coronary heart disease require a strictly
individual approach to correction of their lipid metabolism and special alertness
for cancer in low TSC level.
PMID- 10687198
TI - [Prevalence of cardiovascular diseases in organized groups of employees and
results of long-term multifactorial prevention].
AB - AIM: Evaluation of cardiovascular diseases (CVD) prevalence and their dynamics
after active prevention program. MATERIALS AND METHODS: 1382 male and 155 female
volunteers were included into the group of active prevention in their office.
1024 males and 776 females with natural history were compared as a control group.
5-year follow-up was performed in 543 males and 569 females in comparison with 97
males and 119 females. 10-year follow-up covered 82 males and 191 females from
the active prevention group and 178 males and 118 females from the referent
group. RESULTS: The risk factor correction has resulted in a significant decrease
in both systolic and diastolic BP mean levels, prevalence of ECG abnormalities,
smoking habits, overweight and combination of the risk factors, general mortality
rate, CHD and stroke mortality, number of days of temporary disability.
CONCLUSION: The primary and secondary "in office" prevention for 5 to 10 years
diminishes the prevalence of the risk factors. The temporary and primary
disability rates were connected with the presence of CVD. CVD, in line with other
risk factors, significantly increased cardiovascular and general mortality rates.
PMID- 10687199
TI - [20-year monitoring of acute cardiovascular diseases in population of large
industrial city in West Siberia (epidemiological study)].
AB - AIM: To reveal trends in incidence rates of acute cardiovascular diseases (ACD)
in a large industrial city of the West Siberia. MATERIALS AND METHODS: Studies on
WHO programs "Acute Myocardial Infarction Register" and "MONICA" have been
performed in three districts of Novosibirsk. The diagnostic categories were
detected without difference. The observation covered stable population of 500,000
residents aged 25-64 years. Trends in the myocardial infarction (MI) mortality,
morbidity and lethality were analysed for 1977-1996. RESULTS: The above trends
were stable except for 1986 when MI mortality, morbidity and lethality decreased
and 1988 and 1994 when they went up. The reduction was due to 7-year prevention
program while the rise was consequent to discontinuation of the preventive
measures. Major risk factors of ischemic heart disease, according to screenings
conducted in 1984, 1988 and 1994 remained at about the same level. Social stress
closely correlates with a rise in MI morbidity and mortality. The latter in 1994
grew owing to higher rates of MI mortality and morbidity among the oldest men and
females of different age groups. CONCLUSION: Urgent intensification of
prophylactic measures is needed both at the populational level and the level of
high risk strategy.
PMID- 10687200
TI - [Clinico-psychological features of patients with angina pectoris and obesity].
AB - AIM: To study clinical and psychological features of patients with coronary heart
disease (CHD) and their comparison with obesity. MATERIALS AND METHODS: The
presence and intensity of cardialgia, Ketle's index, body mass fat component,
tolerance to isometric load were determined in 104 patients with stable angina of
effort and 42 healthy males. Questionnaire surveys were performed. 46 obese
patients were reexamined in 7-8 months. RESULTS: Mean body fat mass in anginal
patients was higher than in the controls. Obese patients were more anxious,
psychosocially maladapted, less tolerant to isometric exercise, had more frequent
cardialgia. The attitude of the patients to body mass reduction and its dynamics
depended on personal traits. CONCLUSION: Obesity was observed in the majority of
anginal patients (60.6%) and is closely related to their clinicopsychological
characteristics.
PMID- 10687201
TI - [Program of medical and psychological support of patients after cardiosurgery].
AB - AIM: To study effectiveness of the program of medical and psychological support
of patients after aortocoronary by pass operations (ACBO). MATERIALS AND METHODS:
The trial included 108 patients with coronary heart disease (CHD) after ACBO. 72
patients of the test group participated in the program of medical and
psychological support. 36 patients who did not receive such support served
control. All the patients underwent clinicophysiological and psychological tests
aimed at assessment of exercise tolerance and personality types. RESULTS: Many of
the patients after ACBO need psychological consulting and support. The course of
group therapy gives the patients strong motivation for following the doctor's
recommendations and health self-control. Use of this motivation produced
improvement in psychosomatic health of the test group, increased the percentage
of patients who resumed their previous jobs. CONCLUSION: The program of medical
and psychological support in CHD patients after ACBO increases the effectiveness
of their rehabilitation and psychosocial activity, quality of life and return to
previous job.
PMID- 10687202
TI - [Association of lipoprotein(a) and apolipoprotein(a) phenotypes with coronary and
carotid atherosclerosis in CHD men].
AB - AIM: To evaluate in a case-control cross-sectional study whether lipoprotein(a)
concentration and apo(a) phenotypes are associated with the presence and severity
of coronary and carotid atherosclerosis. MATERIALS AND METHODS: We have examined
198 male CHD patients (mean age 53 +/- 8) years) with stenosis more than 50% at
least in one main coronary artery or its major branches. Duplex scanning was
performed in 168 patients to assess the degree of carotid atherosclerosis.
Seventy six apparently healthy men (mean age 39 +/- 9 years) formed the control
group. Lp(a) concentration was measured by ELISA, apo(a) phenotyping was
performed by immunoblotting. RESULTS: Lp(a) level was significantly higher in
cases compared to controls: 37 +/- 31 mg/dl vs. 18 +/- 27 mg/dl, p < 0.05.
Patients had low-molecular weight apo(a) phenotypes more frequently than
controls: 46% vs. 29%, p = 0.01. Patients aged 45 years and younger had low
molecular weight apo(a) phenotypes more frequently than older ones (65% vs. 42%,
p < 0.05) and controls (65% vs. 29%, respectively, p = 0.001). High Lp(a) level
and low-molecular weight apo(a) phenotypes correlated with presence and number of
coronary occlusions. CONCLUSION: There was association between Lp(a) level, low
molecular weight apo(a) phenotypes and presence, severity, extension of carotid
atherosclerosis. No differences in distribution of other CHD risk factors among
all subgroups of patients were found.
PMID- 10687203
TI - [Prevalence and intensity of smoking among adult urban population of Tiumen':
data of population mail questionnaire survey].
AB - AIM: To estimate prevalence and intensity of smoking among adult Tyumen citizens
by mail questionnaire survey. MATERIALS AND METHODS: A representative sample of
adult population of Tyumen (central district) was randomly selected using the
list of the electors. The questioning covered a total of 3200 citizens (8 groups
per 400 age- and sex-matched subjects). The response reached 71.5%. Smoking in
the population was studied in three aspects: prevalence, intensity and passive
smoking. RESULTS: Overall prevalence of smoking was not great (28.8%), but
smoking was frequent in women, especially young, was intensive in males of all
the age groups. The number of smokers who had quit smoking was small. Passive
smoking at jobs was prevalent. CONCLUSION: The data of the survey indicate
difficulties of social adaptation for the studied population who fall under risk
to develop cardiovascular diseases.
PMID- 10687204
TI - [Features of dopaminergic system function in menopausal females with arterial
hypertension].
AB - AIM: Assessment of dopaminergic activity by changes in urine excretion of
dopamine, arterial hypertension, blood prolactine, 24-h diuresis and natriuresis
in response to a single (2.5 mg) and 7-day (daily dose 5 mg) administration of
parlodel in patients with essential hypertension (EH) in menopausal and
reproductive age having different serum levels of estrogens. MATERIALS AND
METHODS: The indices of 52 hypertensive menopausal women and of 18 women at
reproductive age of whom 8 had hypothalamic syndrome were followed up. RESULTS: A
single dose parlodel (bromocriptine) in the dose 2.5 mg 2 hours after its
administration caused a significant fall in arterial pressure, rise in 24-h
diuresis in hypertensive menopausal women (p < 0.01). Parlodel given in a daily
dose 5 mg for 7 days in menopausal hypertensive women lowered a significant fall
in arterial pressure, blood concentrations of aldosteron, prolactin, aroused
dopamine and urinary sodium excretion (p < 0.01). Similar were the changes in
hypertensive women at reproductive age with hypothalamic syndrome (n = 8). In
such women free of hypothalamic impairment the changes did not occur (n = 10). A
significant positive correlation was found between serum levels of prolactine and
estradiol in all the hypertensive women in menopause. CONCLUSION: Deficiency of
dopaminergic activity in menopause is induced by hypoestrogenemia correlating
with serum levels of prolactin. This deficiency was identified in hypertensive
menopausal women by the results of acute and prolonged tests with dopamine
mimetic--parlodel.
PMID- 10687205
TI - [Effect of enalapril maleate on vascular endothelial function and platelet
endothelial interactions in patients with essential hypertension].
AB - AIM: Evaluation of endothelial function and platelet-endothelial interactions in
patients with essential hypertension and dynamics of these changes in the course
of treatment with enalapril maleate. MATERIALS AND METHODS: The study included 37
patients with essential hypertension and 22 normotensive volunteers. 17 of
hypertensive patients received enalapril maleate (enap, KRKA) 5-20 mg/day during
the period of 1.5 months. The complex of investigations included: measurement of
total plasma cholesteroi, 12-lead ECG, echocardiography, high-resolution
ultrasound investigation of brachio-cephalic arteries, evaluation of flow
mediated dilation, measurement of von Willebrand's factor, spontaneous and
induced platelet aggregation. RESULTS: Patients with essential hypertension
exhibited higher levels of von Willebrand's factor in plasma and degree of
spontaneous and induced platelet aggregation as well as lower responses of vessel
wall to hemodynamic stimuli compared to normotensive healthy individuals. There
was a strong correlation between endothelial function markers and CAD risk
factors, elevation of platelet activity. Treatment with enalapril maleate led to
a statistically significant decrease of von Willebrand's factor in plasma and ex
vivo platelet aggregation whereas flow-mediated dilatation increased. Values of
endothelial function markers and platelet activity approached to those of
normotensive subjects and these changes were accompanied by a decrease of ECG
signs of left ventricular hypertrophy. CONCLUSION: Patients with essential
hypertension were found to have compromised endothelial function. However, the
degree of endothelial dysfunction depends not on hemodynamic parameters, but on
the cumulative effect of CAD risk factors. Treatment with enalapril maleate may
lead to normalisation of endothelial function and decrease of platelet activity.
PMID- 10687206
TI - [Metabolic effects of quinapril in hepertensive patients].
AB - AIM: The study of antihypertensive and metabolic effects of quinapril (accupro)
in patients with essential hypertension (EH). MATERIALS AND METHODS: Serum levels
of cholesterol, its fractions and triglycerides were measured and standard
glucose tolerance test was made in 40 EH patients before accupro therapy and 1
and 3 months after continuous accupro treatment (10-20 mg/day). RESULTS:
Antihypertensive effect of accupro was accompanied by marked improvement in
carbohydrate and lipid metabolism in 28 patients. Normalization of blood pressure
in the absence of negative effect of accupro on parameters of carbohydrate and
lipid metabolism was recorded in 12 patients free of coexisting metabolic
disorders. CONCLUSION: The results of the trial allow to recommend
antihypertensive treatment with accupro as effective both in patients with
metabolic disorders and free of them.
PMID- 10687207
TI - [Some approaches to raising quality of treatment for arterial hypertension
(experience of school for arterial hypertension patients)].
AB - AIM: To investigate involvement of patients into control of their pressure to
improve quality of treatment for arterial hypertension (AH). MATERIALS AND
METHODS: 134 hypertensive patients (76 females and 58 males) were interviewed.
Criteria of efficacy of AH control were ability and motivation of self
measurement of blood pressure and its maintenance at the optimal level. RESULTS:
For the past year, 40% of the patients measured pressure regularly (once a day or
more frequently), 34%--1-3 times a week, 9%--1-3 times a month, 17%--rarely,
mostly, males. Most of the patients controlled their pressure insufficiently.
This is explained by "working pressure" (high in many cases) which was registered
in most of the examinees. When part of the patients reached that working pressure
they discontinued treatment. CONCLUSION: Involvement of hypertensive patients and
members of their families into control of hypertension is a feasible and valuable
method of improving quality of hypertension treatment.
PMID- 10687208
TI - [Clinicofunctional features of arterial hypertension in chronic broncho
obstructive syndrome].
AB - AIM: To describe clinicofunctional features of essential and pulmogenic
hypertension in chronic bronchoobstructive syndrome, 24-h profile of arterial
pressure (AP), intracardiac hemodynamics and to propose differential diagnostic
criteria for these hypertension forms. MATERIALS AND METHODS: 24-h monitoring of
arterial pressure (MAP), cardiohemodynamics, external respiration function (ERF)
and blood gases examinations were made in 100 hypertensive subjects with chronic
obstructive bronchitis and bronchial asthma. RESULTS: Significant differences
were found between the groups of essential and pulmogenic hypertension by major
values of MAP, echo-CG and ERF. Early disturbances in diastolic function of both
the ventricles in essential and pulmonary hypertension in chronic bronchial
obstruction arise long before clinical, x-ray and ECG signs of chronic pulmonary
heart. CONCLUSION: The findings enable formulation of criteria of differential
diagnosis of essential and pulmogenic hypertension and identify the latter as an
independent nosological entity.
PMID- 10687209
TI - [Prehospital treatment of myocardial infarction].
PMID- 10687210
TI - [Arthrotec treatment of rheumatoid arthritis].
AB - AIM: To try arthrotek, a combined drug, in patients with rheumatoid arthritis
(RA). MATERIALS AND METHODS: 10 RA women aged 30 to 60 years with endoscopically
verified minimal affection of gastroduodenal mucosa (not more than 25 hemorrhages
and/or 5 erosions) received arthrotek (1 tablet 3 times a day for 3 months). The
efficacy was judged by changes in the joints and gastroduodenal lesions. RESULTS:
The 3-month treatment produced positive changes in the main auricular and
gastroduodenal symptoms. Side effects (head ache, diarrhea, sleepiness)
disappeared after reducing the day dose to 2 tablets. CONCLUSION: Arthrotek
proved highly effective against RA. It is also a good gastroprotector promoting
healing of gastroduodenal erosions.
PMID- 10687211
TI - [Acute leukemia in adults: morbidity in Donetsk region of Ukraine before and
after Chernobyl' accident].
AB - AIM: To study whether Chernobyl accident has implications for acute leukemia (AL)
incidence rate in Donetsk region. MATERIALS AND METHODS: Records of the Donetsk
regional hematological center for new verified cases of AL have been analysed for
1977-1987 and 1989-1994. RESULTS: Four years after the accident AL morbidity was
higher than before the accident. After 1991 AL morbidity returned to the
preaccident level. CONCLUSION: A rise in AL incidence is attributed to
radionuclide contamination after the Chernobyl accident of a region with
initially unfriendly environment.
PMID- 10687212
TI - [Peculiarities of cell reception in bronchial asthma patients with bronchial
hyperreactivity to hyperosmolar provocation].
AB - AIM: To investigate characteristics of the cell receptor systems in bronchial
asthma (BA) patients with bronchial hyperreactivity (BHR) induced by hyperosmolar
provocation. MATERIALS AND METHODS: 15 patients with BA, in most cases atopic, in
remission were studied. The bronchoprovocative test (BPT) with ultrasonically
nebulized 3.6% hypertonic NaCl solution (UNHS) FEV1-control was performed. Cell
receptors reactivity was analysed on the model of erythrocyte resistance (ER) to
hyperosmolar provocation (HP) under the modulation by adrenergic and
histaminergic agents. RESULTS: It was revealed that ER was significantly higher
(p < 0.05) in BA patients with BHR to UNHS under histaminergic modulation, but ER
did not differ in BA patients with or without BHR to UNHS under the adrenergic
modulation. The correlation was found between DFEV1 on BPT and magnitude of ER to
HP under the blockade of H1-histaminergic receptors (r = 0.72; p < 0.02).
CONCLUSION: The development of BHR to hyperosmolar stimulus may be due primarily
to disturbance of histaminergic receptor system.
PMID- 10687213
TI - [Experience of medical institute therapeutic chair and health service
administration activity].
PMID- 10687214
TI - [General practitioners in Orenburg: pilot experience].
PMID- 10687215
TI - [Irritable bowel syndrome (lecture)].
PMID- 10687216
TI - Highlights & trends. The year in review--Part I.
PMID- 10687217
TI - [The unification of the postings for medical interns and residents].
PMID- 10687218
TI - [The assessment of quality perceived by the users of the basic health areas of
Cuenca].
AB - OBJECTIVES: To find the quality, as perceived by the users, of the health
districts of Motilla del Palancar and Cardenete (Cuenca), and define the
differences, if they exist, between outlying health clinics and central ones.
DESIGN: A descriptive, cross-sectional observation study. SETTING: Health
districts of Motilla del Palancar and Cardenete, both in the Cuenca Health
Region. PARTICIPANTS: A random sample of 442 persons was selected from the 9542
patients with a health card in the health districts under study. MEASUREMENTS AND
MAIN RESULTS: A questionnaire based on the Hulka studies, which had already been
used by the Ministry of Health and Consumption in our field and was of proven
validity and reliability, was administered to each patient. The main researcher
did 442 interviews. The overall assessment by the patients, on a scale from 1 to
7, was 6.07. The scores by patients of the central clinics of the health
districts were, in general, lower than those of patients from the rural nuclei.
CONCLUSIONS: In general, patients gave high scores in their assessment of
perceived quality. Patients in rural nuclei perceived greater health care quality
than those from the main clinics.
PMID- 10687219
TI - [The perceptions of the adult Spanish population of the factors determinative of
health].
AB - OBJECTIVE: To assess which are the most important perceived influential factors
on health among the Spanish adult population. This may provide sufficient
information to promote primary health care campaigns directed specifically to
those that acknowledge that lifestyles are important in spite of not living
healthy lifestyles themselves. DESIGN: Observational cross-sectional study.
SETTING: Spain (Canary Islands not included). PARTICIPANTS: A representative
sample of 1000 Spanish participants over 15 years old selected by a multistage
procedure. INTERVENTION: Survey to evaluate the population choosing one of nine
known health-related factors (smoking, food, alcohol intake, stress, physical
activity, environment, body weight, support from family, genetics) as being one
of the two most important factors influencing health through a validated
questionnaire. MEASUREMENTS AND RESULTS: The chi-square test for linear trend was
used to assess the influence of factors coded on an ordinal scale. The Pearson
chi-square test was applied for categorical factors. Smoking was considered the
most influential health-related factor by most participants (47.8%). Males, those
from lower socioeconomic and educational levels; people living in the south of
Spain, and rural regions; those married and individuals who had 3 or more
children below 15 years, perceived smoking more often as one of the most
important determinants of health. CONCLUSIONS: These data suggest that a large
percentage of the Spanish adult population recognizes that life-styles are
important determinants of health.
PMID- 10687220
TI - [The program for the control of temporary incapacity at the Instituto Social de
la Marina of the province of Cadiz].
AB - OBJECTIVE: To evaluate the results of a programme of intervention into the
monitoring of short-term unfitness for work of members of the Special Sea Regime
at Cadiz during 1997. DESIGN: Quasi-experimental intervention study with a pre-
and post-intervention group, formed by the doctors from the Instituto Social de
la Marina (ISM) at Cadiz. SETTING: Primary care, 1997. PARTICIPANTS: 21 doctors
carrying out their health-care duties in the ISM clinics. INTERVENTION:
Activities aimed at the doctors, seeking to highlight the need to protect workers
suffering incapacitating pathologies. MEASUREMENTS AND MAIN RESULTS: In January
the indices of those off work were similar (2.38 in January 1996, and 2.39 in
January 1997). Then the differences widened, with September 1997 (2.42) marking
the biggest difference with the same month in 1996 (1.44). However, the mean
length of the periods of time off was greater in 1997 than in 1996. The number of
sick certificates processed in 1997 (1233) was less than in 1996 (1326). But the
opposite occurred with notes for return to work (1209 in 1996 and 1311 in 1997).
The mean duration of the period of time signed off increased after the
intervention. CONCLUSIONS: A quantitative change in the indicators of management
of short-term unfitness for work occurred.
PMID- 10687221
TI - [The introduction of generic pharmaceutical products into Galicia].
AB - OBJECTIVE: To know the evolution of the introduction of generic drugs (GDs) in
Galicia. Secondarily, to evaluate its potential impact on pharmaceutical
expenditure. DESIGN: Descriptive study of GDs utilization. Cost-minimization
analysis. SETTING: Galician autonomous region, year 1998. MEASUREMENTS AND
RESULTS: Using data from the prescription billing registry of Social Security we
have selected the active ingredients corresponding to GDs with prescriptions in
Galicia in 1997. We have analyzed the data for their oral single substance
preparations by quarters. Consumption in DHDs of allopurinol, atenolol,
captopril, naproxen and ranitidine remained stable during 1998. The market share
for their GDs in quantitative terms relative to both total consumption of the
active ingredients and to their pharmaceutical equivalents, showed an overall
growing trend. The maximum observed value was seen for ranitidine at last
quarter. Total expenditure (in final customer prices) during 1998 on the selected
active substances was higher than 1864 million pesetas. Potential savings
afforded by substitution for the lowest price GD prescribed in Galicia would
reach 427 million pesetas. CONCLUSIONS: GDs market penetration in Galicia during
1998 was limited but increasing. Its utilization may afford estimated savings of
21-28% of the cost for the selected drugs. However, the expenditure on the above
drugs was just 2.7% of total pharmaceutical expenditure.
PMID- 10687222
TI - [The social and health variables associated with the self-perception of the
health status of the adult population of Gran Canaria (Canary Islands)].
AB - AIM: To find out how the adult population in one municipality of the Canary
Islands perceives its state of health, and how this is related to social and
health variables. DESIGN: Descriptive cross-sectional study. PLACE: Telde (Gran
Canaria). SUBJECTS: The municipality has a population census of 79,000
inhabitants. The sample was multistepped and selected randomly. It included 2626
people with a population variance of p = q = 50%, standard error +/- 4% with a
confidence interval of 95.5%. Participation rate was of 82.5%. MEASUREMENT AND
RESULTS: Data on aspects of socio-demography, morbidity, medication, use of
public health facilities and lifestyles were collected via personal
questionnaire. The relationship between different variables and people's
perception of their health was calculated by odds ratio using logistic
regression. Almost 50% of the sample perceived their state of health to be
excellent or good. Subjects over the age of 45 (OR, 2.89), or who were
unemployed, perceived themselves to be in a worse state of health (OR, 1.34).
Contrastingly, those who had received higher education (OR, 0.39), or who, in the
previous 15 days, had not been confined to bed (OR, 0.22), had not been on sick
leave (OR, 0.23) or had not visited the doctor (OR, 0.38) had a better perception
of their health. CONCLUSION: People's perception of their health is related to
their quality of life and self-esteem and continues to be a useful indicator in
the evaluation of their general state of health, reflecting aspects of both
social level and health.
PMID- 10687223
TI - [How we use opioid drugs on patients with neoplasms].
AB - OBJECTIVE: To find the pattern of use of opiate drugs for treating pain in
terminal cancer patients. DESIGN: Retrospective descriptive study. SETTING: Gava
2 Health Centre, located in Barcelona's industrial belt. MATERIAL AND METHOD:
Systematic review of the clinical records for the deaths recorded between May
1993 and March 1998. The following variables were recorded: age, sex, cause and
place of death, professional attending patient during terminal phase, use of
opiates (type, how they were taken, dosage and length of treatment) and
prescribing doctor. RESULTS: Of the 429 deaths reviewed, 100 (23%) were caused by
neoplasm (68% males), with an average age of 69 +/- 3 years. More than half the
patients (55%) died at home. In the terminal phase they were mainly attended
(69%) by their Primary Care team. 52% of the patients were given opiates, with
morphine being the most common (71.1%), followed by codeine (40.3%) and tramadol
(17.3%). The general practitioner was the prescribing agent in 69.2% of the
cases. 76% of the patients who took codeine did so at infra-therapeutic doses (<
120 mg per day). Similarly, insufficient doses of morphine (< 60 mg per day) were
given to half the patients who received it. 21.62% only took it during a period
of 5 days or less before death. CONCLUSIONS: Primary care teams are taking on
steadily greater protagonism in caring for terminal cancer patients. Although a
large number of these patients are treated with opiates, these are given at often
insufficient doses and for too short time periods.
PMID- 10687224
TI - [Electronic journals in primary care].
PMID- 10687225
TI - [How many more diabetics do I have?].
PMID- 10687226
TI - [The group education of diabetics].
PMID- 10687227
TI - [Antidepressants and sexual dysfunction].
PMID- 10687228
TI - [Clinical changes in patients undergoing group diabetes education].
PMID- 10687229
TI - A clinical review of drug-induced gingival overgrowths.
AB - There is an increasing number of medications associated with gingival overgrowth.
These medications are used to treat a number of common conditions in the
Australian population and as such dentists can expect to manage a number of
patients with medication-related gingival overgrowth. This review highlights the
clinical features and management of the common overgrowths associated with
anticonvulsants, immunosuppressants and the calcium channel blockers.
PMID- 10687230
TI - Prophylactic removal of asymptomatic third molars: a review.
AB - Mandibular and maxillary third molars are mostly consigned to 'waste bins' in
dental practices because they are terminal in developmental timing and
positioning in the dental arches, and regarded as functionally non-essential.
Thus, many dental practitioners do not attach significance to the presence of
third molars when making therapeutic recommendations to patients about
preservation of the dentition. The need for taking more a serious account of
third molars is reviewed in this paper.
PMID- 10687231
TI - Australian dental schools: moving towards the 21st century.
AB - In Australia nearly all tertiary education is funded through the Federal
Government. With reductions in government spending tertiary education has had to
accommodate its share of the cuts. Under such a climate dental schools in
Australia face serious financial difficulties, in addition to many other diverse
threats, as they head towards the 21st century. Most seriously, and almost
uniformly felt, is the diminution of Federal Government funding to a point where
the operation of some dental schools remains viable only by way of supplementary
funding (direct or in-kind) from State Governments. In this report the authors
have developed one possible model of academic, clinical and financial structures
of a dental school, based on sound educational and economic grounds, that can
overcome some of the short-comings of the paradigm that exists in some schools in
Australia. The two key factors underlying the principles of this model for a new
style of dental school are flexibility and professional responsibility. Based on
the existing academic and economic realities it would be much more appropriate to
outsource a significant proportion of the educational and clinical component of a
dental school. Highly trained individuals from the dental profession would be
invited to provide training in their area of expertise. The role of the dental
school would evolve to be like a facilitation centre, organizing the various
courses. It would mean that the 'core' curriculum would be the responsibility of
the school's academic staff and the outsourced professional members would
contribute within the bounds of the basic framework. On the basis of this model a
dental school of approximately 225 full-time undergraduate students (50 per year,
less some student loss) in a five year programme is planned, and annual staffing
costs are estimated at $1.4 million.
PMID- 10687232
TI - Hyperbaric oxygen in the prevention of osteoradionecrosis of the jaws.
AB - Patients who have had their jaws irradiated as part of management of head and
neck malignancy are at risk of osteoradionecrosis (ORN) following tooth
extraction. Thirty-seven patients with a history of irradiation to the jaws were
managed during a four year period. Twenty-nine patients received hyperbaric
oxygen therapy (HBO) consisting of 20 treatments before surgery and ten
treatments after. Only one (4 per cent) developed ORN. Seven patients who did not
have HBO and one who did (15 per cent) developed ORN. The need for prophylactic
treatment with HBO is discussed. It is recommended that prophylactic HBO is used
prior to surgery for irradiated facial bones.
PMID- 10687233
TI - Cytotoxicity of polymerized commercial cyanoacrylate adhesive on cultured human
oral fibroblasts.
AB - Cyanoacrylate (CA) has been used as both a commercial and tissue adhesive.
Dentists may have had the experience of patients repairing their own acrylic
based dentures using a cyanoacrylate (CA) adhesive known as 'super glue'. This
study evaluated the cytotoxicity of commercial CA adhesives when fully
polymerized, as well as the toxicity of substances released from polymerized
commercial CA adhesives after incubation of these materials for various periods
of time. Toxicity was tested on cultured oral fibroblasts. Dead cells found
around the various CA-coated filter papers constituted inhibitory zones which
varied from 200-1000 microns and which persisted for two weeks. Control oral
fibroblasts grew to approach the wax-coated filter paper. Cell viability testing
using MTT and crystal violet staining methods supported the conclusion that
polymerized CA-coated filter paper released substances that are toxic to cells,
while wax-coated filter paper gave the same result as the control. The crystal
violet staining method was also used to investigate the cytotoxicity of various
CA materials after incubation for one, three, seven and 14 days and showed that
CA continued to release cytotoxic substances at about the same level for at least
two weeks. It can be concluded that, if CA adhesive is used for repair of broken
dentures, it will release substances which are toxic to human oral fibroblast
cells. This release of substances may persist for at least two weeks.
PMID- 10687234
TI - Public knowledge of the prevention of dental decay and gum diseases.
AB - In 1992, a mail survey was conducted among South Australians aged 10 years and
older to assess the knowledge of prevention of dental caries and gum diseases and
to explore its variation by sociodemographic factors. The survey provided 838
completed questionnaires. Questions were asked on perceptions of importance of a
number of preventive measures, the main purpose of water fluoridation and sources
of information. Respondents rated four myths for preventing dental caries as the
most important: 97 per cent rated regular tooth brushing; 87 per cent rated
regular dental visits; 85 per cent rated calcium in the diet; and 78 per cent
rated eating fibrous foods as definitely or probably important. Only 56 per cent
of respondents rated drinking water with fluoride as definitely or probably
important for preventing dental caries, and only half (50.2 per cent) identified
the main purpose of water fluoridation as the prevention of decay. Respondents
rated regular tooth brushing (96 per cent) and regular dental visits (87 per
cent) as important for the prevention of gum diseases. However, the myth of
massaging the gums was rated as important by 67 per cent. Higher percentages of
females, older adults and those with lower educational attainment rated the myths
for preventing caries as important. Younger people were less able to specify the
main purpose for fluoridation of water supplies. The persistence of myths and the
low rating of the importance of scientifically efficacious measures are major
challenges for oral health promotion.
PMID- 10687235
TI - Child abuse and dentistry: a study of knowledge and attitudes among dentists in
Victoria, Australia.
AB - Child abuse is a disturbingly common finding in society today. In view of the
high proportion of orofacial injuries seen in victims of child abuse, dentists
are in a strategic position to recognize and report suspected cases. The present
study of 347 dentists in Victoria, Australia, assessed the level of knowledge and
attitudes among dental professionals on the important issue of child abuse. While
a high level of interest was shown by the participants towards this issue, a need
for further information and training in the recognition and reporting of child
abuse was seen in the survey findings. While dentists at present are not legally
mandated in all states of Australia to report suspected cases of child abuse, the
dental profession is in a key position to play an active role in the
identification and reporting of this substantial community problem.
PMID- 10687236
TI - The use of glass ionomer in special needs patients.
AB - Placement of restorations for patients who are physically or intellectually
disabled or mentally ill can pose considerable difficulties for the general
practitioner. Access to the oral environment is often limited and patient
tolerance and concentration may be reduced to rather brief periods of time. Oral
hygiene routines may be less than ideal leading to a high caries rate. Enamel
surfaces which do not normally become carious can develop broad but shallow
lesions with a poorly defined outline. Selection of the most suitable restorative
material will be important, with longevity of the restoration as the prime
consideration. Other factors such as access, isolation of the lesion and patient
co-operation must also be taken into account. Also, forces acting on restorative
materials may be less than usual due to poor occlusion, teeth opposing dentures
or being completely unopposed. Restoration by indirect techniques will often not
be possible so the choice will be limited to the three plastic restorative
materials normally used in restorative dentistry: amalgam, resin composite and
glass ionomer. As a result of clinical experience it is suggested that glass
ionomer will often be the material of choice. This paper describes five years
experience with the resin-modified glass ionomers in an institutional practice
which is limited to patients with special needs. Clinical significance Placement
of restorations, with a reasonable expectation of longevity, can pose
considerable problems for the patient with special needs. Resin-modified glass
ionomer is a useful alternative material and has been placed with a high degree
of success over a period of five years.
PMID- 10687237
TI - A programme for the treatment of severe dental fear. Report of three cases.
AB - This paper describes the use of a sequence of recollection and discussion,
training in muscle tone control, dental imagery, audio simulation and graded re
exposure to dental procedures to eliminate a severe fear of dental treatment in
three adult female patients. All three patients had abstained from regular dental
visits throughout their lives and all were in need of urgent dental treatment
when the therapy began. One of the patients also identified in herself other
maladaptive behaviour and reported a history of mood disorder as well. The
recollections of these patients reveal that the aetiology of dental fear is more
complex than dental questionnaires would indicate and, in particular, they supply
further evidence of the capacity for adverse medical events to initiate this
fear. Although the programme specified in this paper yielded good results, it
nonetheless has a number of shortcomings. It is time consuming, dental damage is
likely to be well advanced when it commences and it attracts very few patients.
Thus those afflicted with severe dental fear are effectively destined for only
emergency dental visits and eventually are likely to be edentulous. For this
reason every possible precaution against the initiation of dental fear should be
taken.
PMID- 10687238
TI - Bilateral congenitally missing maxillary canines. A case report.
AB - Exclusive aplasia of maxillary permanent canines is extremely rare. There are
only a few cases of this condition reported in the literature. This paper reports
a case of bilateral congenitally missing canines in a healthy 11 year old male of
Chinese origin. The article discusses problems in diagnosis and presents options
in the management of such a case. The management option selected was the most
appropriate for the family at the time of presentation.
PMID- 10687239
TI - Resin ionomer restorative materials for children: a review. Author's reply.
PMID- 10687240
TI - Temporomandibular joint arthroscopy.
PMID- 10687241
TI - Hydrophilicity?
PMID- 10687242
TI - [The production of swine intended for xenotransplants].
AB - Allotransplantation of organs is one of the most prominent medical achievements
of this century. The success of allotransplantation has, however, provoked a
problem or organ shortage. In order to overcome these problems, the possibility
of using animals as potential donors for humans (xenotransplantation) is
considered. Many investigators recently proposed the pig as an alternative source
of organs. Pigs are easy to breed, have anatomical and physiological
characteristics compatible with humans, and are well studied for several
pathogens potentially transmissible to humans. Moreover transgenic pigs can be
obtained expressing human proteins in order to resist hyperacute rejection.
Caesarean-derived piglets can easily be maintained gnotobiotics or specified
pathogen free. The pig being nowadays the best candidate for xenotransplantation,
this paper will focus on the potential public health risk linked to the use of
this species as a source of organs, and the general rules to follow in order to
manage it, (risk management).
PMID- 10687243
TI - [Regulation of pulmonary circulation by the vascular endothelium].
AB - The function of the endothelial mediators on lung vessels is progressively
understood. Our experimental results, in agreement with those from other
laboratories, show that prostacyclin and nitric oxide do not affect basal
pulmonary vascular tone, but that they limit the pulmonary hypertension secondary
to alveolar hypoxia, or to lung injury. The role of endothelins remains harder to
define, partly because their vascular effects are opposed by nitric oxide in
intact animals.
PMID- 10687244
TI - [Inter-species transmission of the influenza virus].
AB - Influenza is an infection of human beings and several animal species. It is
caused by influenza viruses which belong to the Orthomyxoviridae family. Type A
influenza viruses are the most important as they cause severe epidemics and are
responsible of important pathological troubles. Type A influenza viruses are
classified in different sub-types depending of the nature of their surface
glycoproteins: haemagglutinin (H) and neuraminidase (N). The nature of the genome
and the mode of replication of influenza viruses account for the high variability
of these two proteins which are responsible for the immunity to the virus. The
continuous appearance of point mutations in the gene coding for the H protein,
leads to the progressive emergence of new viral strains. This event which is
called antigenic drift makes it necessary to annually assess the composition of
the human flue vaccine. Genetic reassortment is another mechanism of antigenic
variation. When the gene coding for the H protein, or when both genes coding for
H and N proteins are involved in genetic reassortment, a new viral sub-type
occurs which replace the precedent. This event, which is termed antigenic shift,
occurs occasionally every 10 to 30 years, and it is responsible of the great
human pandemics. The role of the animals and particularly the importance of pigs
and poultry in the emergence of these new viruses is discussed.
PMID- 10687245
TI - [The artificial lens: the folly of yesterday, the standard of today].
AB - Traditional cataract operation (dislocation of the crystalline lens into the
vitreous body by external pressure or by needling) is nearly as old as mankind.
The idea of implanting an artificial lenticulus is not new but this was only
performed for the first time in 1949. In the last 50 years, a better knowledge of
corneal and retinal physiology, as well as the improvements of intraocular lens
material and design, have led to very safe routine surgery.
PMID- 10687246
TI - [The Faculty of Medicine and the medical practitioner in the 21st century].
PMID- 10687247
TI - [Kashin-Beck disease in China: osteochondrodysplasia related to nutrition and
environment].
AB - Kashin-Beck disease is a endemic juvenile osteochondrodysplasy, whose association
with selenium deficiency and/or mycotoxin toxicity has been corroborated by
epidemiological studies in China, including Tibet. Iodine deficiency appears to
be a new etiological factor. Together with the geographical and epidemiological
exploration of the disease, scientific multidisciplinary investigations (clinics,
radiological imaging, histology, environmental and molecular biology) should
afford to understand the cause of the disease before it disappears as a
consequence of the evolution of the Chinese Society, including in Tibet.
PMID- 10687248
TI - [The program for the elimination of leprosy: ambitious challenges, novel
approaches, issues in doubt].
AB - The WHO-sponsored programme on the "elimination of leprosy as a public health
problem by the Year 2000" has been highly successful. Over 9 million patients
were treated by multiple drug therapy. The number of patients world-wide has been
reduced by more than 90 per cent over the last 10 years, being at present less
than 800,000. Transmission however, the ultimate goal of the programme, has not
been interrupted. The number of new cases detected per year is still high. This
observation raises serious questions regarding the future of the programme.
PMID- 10687249
TI - [Nuclear arms and medical responsibility].
AB - The medical profession would be unable to cope with the millions of simultaneous
casualities of a nuclear war. Such a war between developed countries becomes less
likely, but new countries equip themselves, with nuclear weapons, using the
violation of the Non-Proliferation Treaty by the great powers as an excuse. The
danger of nuclear war is spreading with the consequences one can imagine. A world
movement, including military experts, political, moral and scientific leaders and
representative national medical groups, among them the World Medical Association,
press governments to negotiate a comprehensive abolition treaty. The "Academie
royale de Medecine de Belgique" joining moral prestige to an authoritative
expertise, should take a stand on the problem.
PMID- 10687250
TI - Common painful foot syndromes.
AB - The prevalence of foot problems in the general population is 10%, and in the
elderly it ranges from 53% to 95%. Proximal plantar fasciitis is the most common
cause of painful feet in clinical practice, and is twice as common among women as
among men. Metatarsalgia is probably the most common cause of foot pain among
middle-aged women.
PMID- 10687251
TI - C-reactive protein on admission as a predictor of in-hospital death in the
elderly with acute myocardial infarction.
AB - BACKGROUND: The mean age of patients with acute myocardial infarction is
increasing and the associated in-hospital mortality is exponentially age-related.
Inflammation markers have been related to cardiovascular short and long-term
prognosis. The aim of this study was to evaluate the short-term prognostic value
of C-reactive protein (CRP) levels on admission in the oldest segment of the
patients with acute myocardial infarction. METHODS: CRP was prospectively
measured on admission by immunonephelometry in 205 consecutive old women (mean
age 82 +/- 5 years) with definite acute myocardial infarction; values were then
related to in-hospital mortality and the causes of death. RESULTS: CRP levels
ranged from 0.1 to 31.9 mg/dl and were raised in 71% of the patients. It showed
no significant correlation with baseline clinical variables such as age, history
of diabetes or hypertension or prior myocardial infarction, infarct location, and
time from symptom onset to admission. The overall in-hospital mortality rate was
25% and rose from 15% among patients in the lower three quartiles of CRP levels
(cut point 6.4 mg/dl) to 55% among those in the upper quartile (p < 0.001). By
univariate logistic-regression, the odds ratio for early death was 0.84 (95%
confidence interval 0.78-0.89) for every increase by 1 mg/dl of CRP, and 5.7 (95%
confidence interval 2.7-11.9) for a CRP level in the upper quartile. Multivariate
analysis demonstrated the independence of the relation between CRP levels and in
hospital mortality (p = 0.0001). No significant differences in CRP level were
found among deceased patients classified by cause of death (heart rupture 44%,
pump failure 41%, comorbidity 5%). CONCLUSIONS: CRP concentration is raised in
many old patients with acute myocardial infarction and seems to independently
stratify patients for in-hospital mortality risk. This prognostic information may
assist in providing the appropriate level and duration of close monitoring and be
an additional support to evaluate the risk-benefit ratio of thrombolytic therapy
in some cases.
PMID- 10687252
TI - Long-term prognostic value of the stenosis of the infarct-related artery and the
presence of viable myocardium in akinetic ventricular regions in infarcted
patients.
AB - BACKGROUND: Recent studies have reported that adequate perfusion of the infarct
related artery improves survival in patients with myocardial infarction,
independently of left ventricular pump function. However, it is not known whether
or not this reduction in mortality is independent of myocardial viability within
the infarct zone. The aim of this study was to evaluate the prognostic value of
the patency of the infarct artery and the presence of myocardial viability in
akinetic regions in patients with myocardial infarction. METHODS: Low-dose
dobutamine echocardiography was performed in 154 patients with recent or previous
myocardial infarction and known coronary anatomy. In each patient three vascular
regions were defined. Each akinetic region was considered viable if function
improved during dobutamine echocardiography, and irrorated by a not stenotic
akinetic area-related artery if the supplying vessel had a stenosis < 75% or had
been successfully revascularized within 1 month of dobutamine echocardiography.
RESULTS: At follow-up of 34 +/- 14 months, 19 patients died of cardiac death. At
univariate Cox analysis end-diastolic and end-systolic volumes, ejection
fraction, previous myocardial infarction, regional wall motion score index, and
stenosis of the akinetic area-related artery were related to mortality. At
multivariate analysis, stenosis of the akinetic area-related artery remained a
significant predictor of mortality (p = 0.04), with higher mortality (13/66 vs
6/88, p = 0.02) in patients with a stenotic akinetic area-related artery, without
differences in ejection fraction (35 +/- 9 vs 34 +/- 10%). Mortality was lower in
patients with myocardial viability if they had a not stenotic akinetic area
related artery (1/43 vs 4/21, p = 0.02), while no difference was found among non
viable patients, with or without stenosis of the akinetic area-related artery
(5/45 vs 9/45). CONCLUSIONS: The present study confirms the prognostic role of
the patency of the infarct-related artery. However, it suggests that the lower
mortality in patients with a patent artery supplying akinetic infarcted regions
is related to the presence of myocardial viability in these regions.
PMID- 10687253
TI - Acute anterior myocardial infarction: increased dye intensity in the myocardial
risk area after coronary angioplasty is associated with reduction of diastolic
volumes.
AB - BACKGROUND: Myocardial perfusion in the risk area during the acute phase of
myocardial infarction has been extensively investigated over the last few years.
The so-called "no-reflow" or "low-reflow phenomenon" (absence of myocardial
perfusion despite patency of the infarct-related coronary artery) was shown to
correlate with worse postinfarction remodeling, in particular when myocardial
contrast echocardiography was used. The aim of this study was to determine,
during routine coronary angiography performed before and after coronary
angioplasty (PTCA) during the acute phase of myocardial infarction, the existence
of the no-reflow phenomenon and its relation with ventricular remodeling, by
evaluating the dye video density in the myocardial risk area. This confirmation
by a different diagnostic technique may serve to highlight the role of myocardial
perfusion as an index of prognosis in the clinical setting of acute myocardial
infarction. METHODS: Twenty-six patients (23 males, 3 females, mean age 57 +/-
8.7 years) who underwent either rescue (n = 11, 42.3%) or primary PTCA, according
to clinical indications, of the left anterior descending coronary artery during
an acute anterior myocardial infarction and who did not have stenosis of the left
circumflex or right coronary artery, were retrospectively selected from a 6 year
intake. The extent of coronary stenosis was assessed using biplane quantitative
coronary angiography, while end-diastolic and end-systolic volume indexes,
together with regional wall motion, were computed from echocardiography performed
in the first 24 hours and at 6 months. Patients were subdivided into two groups
on the basis of dye video intensity in the risk area, as assessed from images
obtained during left main coronary artery injections before and immediately after
PTCA. It was used a subtraction technique (Group A: increased video intensity, n
= 12; Group B: no change, n = 14), assuming that higher peak intensity reflects
greater myocardial blood volume. Three patients in Group B with ineffective PTCA
were excluded, so that the final number of considered patients was 11. RESULTS:
The distribution of rescue PTCA was similar in the two groups (7 in Group A vs 3
in Group B, p = 0.13) as were clinical characteristics and therapeutic regimen.
There was a significant time * group interaction for end-diastolic volumes (-4.6
+/- 23% in Group A vs +22 +/- 22% in Group B, p = 0.029), whereas end-systolic
volumes showed a tendency to greater dilation in Group B (+19 +/- 28% vs +0.9 +/-
31% in Group A), although this difference was not significant (p = 0.27). No
interaction was evident for increase in the vessel area (+46 +/- 12.5% in Group A
vs +43.2 +/- 13.6% in Group B, p = 0.99), or for extent of regional dysfunction
(+3.08 +/- 10.9 chords in Group A vs -2.5 +/- 9.5 chords in Group B, p = 0.50).
CONCLUSIONS: The detection of myocardial blood volume in the risk area using dye
video intensity during left main dye contrast injection, is useful to distinguish
whether there is improved perfusion at the muscular level, following successful
angioplasty of the infarct-related coronary artery. Lack of improved myocardial
perfusion has an adverse effect on left ventricular volumes independently of
coronary stenosis resolution and regional wall motion changes in the time.
PMID- 10687254
TI - Increased plasma levels of fibrinogen in acute and chronic ischemic coronary
syndromes.
AB - BACKGROUND: The aim of this study was to evaluate the pathophysiological role of
fibrinogen in patients with chronic or acute ischemic coronary syndromes on the
basis of epidemiological and clinical evidences showing the importance of
fibrinogen as a risk factor for cardiovascular diseases and atherosclerosis
progression. METHODS: We evaluated the behavior of plasma fibrinogen in 310
hospitalized patients with 1) acute myocardial infarction (n = 98); 2) unstable
angina (n = 87); 3) chronic ischemic heart disease (n = 75); and 4) in controls
without myocardial ischemia (n = 50). Fibrinogen was evaluated, by using the
Clauss method, on day 1 and 5 during in hospital-stay and at 6-month follow-up in
patients suffering from acute myocardial infarction. RESULTS: Plasma levels of
fibrinogen were higher in patients with chronic ischemic heart disease (335.3 +/-
81.2 mg/dl, p < 0.001) and especially in patients with acute myocardial
infarction (454.72 +/- 69.5 mg/dl, p < 0.00001) and unstable angina (382.6 +/-
101.3 mg/dl, p < 0.00025) in comparison with controls (271.28 +/- 62.4 mg/dl). Q
wave myocardial infarction showed higher levels of fibrinogen than non-Q wave
(461.3 +/- 95.8 vs 422.5 +/- 71.3 mg/dl, p < 0.02). Patients with acute
myocardial infarction showed a further increase in fibrinogen on day 5 in
comparison with entry levels (525.88 +/- 87.3 vs 454.7 +/- 69.5 mg/dl, p <
0.00001) regardless of the fibrinolytic treatment. Patients who died (n = 6) or
had severe arrhythmias (n = 4) during in-hospital stay as well as those with post
infarction angina (n = 20) showed higher fibrinogen levels. CONCLUSIONS: Our
results confirm the role of fibrinogen as a risk factor for ischemic heart
disease, especially in patients with unstable angina and acute myocardial
infarction. In the latter, elevated fibrinogen values seem also to be associated
with a worsen prognosis during hospitalization.
PMID- 10687255
TI - Color duplex scanning for the identification of extracranial atherosclerosis in
patients with suspected coronary artery disease.
AB - BACKGROUND: The presence of extracranial artery disease has been used as a
predictor of coronary artery disease (CAD). The present study was conducted to
test the prevalence of extracranial artery disease among patients with suspected
CAD. METHODS: Among candidates for coronary arteriography, 400 consecutive
patients (mean age 63 +/- 11 years, 78% males, 22% females) underwent color
duplex ultrasound of carotid arteries. RESULTS: Extracranial artery disease was
documented in 60 patients (15%), CAD in 309 patients (77%). Patients with
extracranial artery disease were significantly older (p < 0.001), smoked a higher
amount of pack-years (p < 0.001), showed a higher incidence of diabetes (p <
0.01), hypertension (p < 0.05) and CAD (p < 0.05) when compared to extracranial
artery disease-free subjects. Plotting age against extracranial artery disease
and CAD distribution, extracranial artery disease occurred later in life than CAD
(p < 0.001). The best cut-off point of age for predicting extracranial artery
disease was 68 years. Carotid angiography was performed in 114 patients after
cardiac catheterization (k = 0.8044 with color duplex scanning). CONCLUSIONS:
Extracranial artery disease is frequent among patients undergoing coronary
arteriography. Carotid ultrasound screening is useful in older patients.
PMID- 10687256
TI - Can aortocoronary and peripheral venous bypass graft patency be improved by the
administration of pentoxifylline on a long-term basis?
AB - BACKGROUND: Venous bypass grafts to coronary and peripheral arteries have a high
rate of occlusion at follow-up. Pentoxifylline, known to reduce blood viscosity,
has the potential theoretically to reduce venous graft occlusion. We tested this
hypothesis in this study. METHODS: The effect of pentoxifylline (Trental) on the
early and late failure of venous bypass grafts was studied on 107 patients who
underwent a total of 159 aortocoronary and 55 peripheral venous bypass grafts.
Pentoxifylline was initially administered in the prime of the heart-lung machine
in coronary patients and intra-arterially in peripheral vascular patients. All
patients were treated postoperatively with oral administration of pentoxifylline
at a dose of 400 mg daily, during the 2-year follow-up period. The short- and
long-term graft patency in this unit was compared to that of an identical placebo
unit, composed of 105 patients (141 aortocoronary and 55 peripheral venous bypass
grafts). The patients of the placebo unit had the same operative treatment but
were not treated with pentoxifylline. These patients were pre- and
postoperatively examined by the same methods as the patients of the
pentoxifylline unit. RESULTS: The 2-year follow-up demonstrated that in cardiac
patients aortocoronary graft patency was 92.5% in the pentoxifylline unit, and
80.6% in the placebo unit. Similar results were observed in peripheral vascular
patients, as well as in a small group of patients with multifocal arterial
disease. CONCLUSIONS: These results indicate that pentoxifylline affects
favorably the patency of both aortocoronary and peripheral bypass grafts.
PMID- 10687257
TI - Comparison of trimetazidine with atenolol in patients with syndrome X: effects on
diastolic function and exercise tolerance.
AB - BACKGROUND: Trimetazidine has been shown to improve anginal symptoms without
altering hemodynamic variables in patients with coronary artery disease. The aim
of this study was to compare the effect of trimetazidine and atenolol upon
symptoms, resting left ventricular filling dynamics and exercise tolerance.
METHODS: Sixteen patients (3 males, 13 females, mean age 62 +/- 7 years) were
randomized to receive trimetazidine for 2 weeks (20 mg 3 times daily) or atenolol
(100 mg daily), according to a double-blind, randomized, cross-over, placebo
controlled design. At the end of each treatment period patients underwent symptom
limited exercise testing, an echocardiogram and a Doppler assessment of
transmitral flow pattern. Daily life anginal symptoms were annotated on a diary
throughout the study. Two patients discontinued trimetazidine because of severe
palpitations and only 14 patients completed the study. RESULTS: Atenolol
significantly reduced the number of anginal episodes as compared to placebo or
trimetazidine (0.44 +/- 0.53, 4.8 +/- 4, 2.9 +/- 4.9, p < 0.01). On atenolol, the
exercise test was negative in 8 patients, but none of the patients had a negative
test while on trimetazidine. Atenolol increased both time to 1 mm ST segment
depression (668 +/- 213 vs 838 +/- 81 s, p < 0.05) and Doppler-derived indices of
ventricular filling (E/A ratio 0.87 +/- 0.20 vs 1.21 +/- 0.26, p < 0.05).
CONCLUSIONS: These results confirm the beneficial effects of atenolol in
improving symptoms, exercise performance and diastolic function in syndrome X
patients. Trimetazidine did not exert any significant effect on any of the
analyzed variables. Since trimetazidine has been previously shown to improve
myocardial ischemia in patients with overt coronary artery disease to a similar
extent of beta-blockers, it is likely that other mechanisms are responsible for
angina in patients with syndrome X.
PMID- 10687259
TI - [Further comment on pulmonary embolism].
PMID- 10687258
TI - [Angiotensin-II receptor inhibitors in hemodialysed uremia patients with arterial
hypertension: candesartan cilexitil versus losartan].
AB - BACKGROUND: The aim of this study was to evaluate, in patients with chronic renal
failure in hemodialysis and arterial hypertension, the effectiveness of a new
angiotensin II receptor antagonist, the candesartan cilexitil, comparing it with
losartan, the first of this new class of drugs. METHODS: We have selected 128
patients with chronic renal failure (92 males and 36 females, mean age 56 +/- 6
years) and arterial hypertension, subjected to hemodialysis 3 times a week, with
hemodialytic seniority of 90 +/- 10 months. The inclusion criteria in the study
were given from the presence, after 15 days of pharmacological wash-out, of
values of diastolic blood pressure (DBP) > or = 95 mmHg and systolic blood
pressure (SBP) > or = 150 mmHg, despite a hemodialysis correctly performed.
Patients were divided into two groups whether they received single blind
randomized candesartan cilexitil 16 mg or losartan 50 mg at hour 8.00 for a
period of 8 weeks at the end of which, after a period of pharmacological wash-out
of 15 days, the drugs were administered to inverted groups for other 8 weeks.
After 4 and 8 weeks of treatment an evaluation of the anti-hypertensive
effectiveness by means of medical complete visit and measurement of blood
pressure were made. The statistical analysis was made by means of Student's t
test for paired data. RESULTS: All the patients concluded the study. After 4
weeks of treatment SBP and DBP were reduced in the group with candesartan
cilexitil with regard to baseline values (SBP 151.8 +/- 6.3 vs 159.8 +/- 5.1
mmHg, p < 0.05; DBP 93.6 +/- 4.5 vs 98.1 +/- 3.7 mmHg, p < 0.05). In the losartan
group (SBP 151.8 +/- 6.3 vs 158.7 +/- 5.5 mmHg, p < 0.05; DBP 93.6 +/- 4.5 vs
97.5 +/- 3.8 mmHg, p < 0.05) no significant reduction in blood pressure values
was observed compared with baseline values (SBP 158.7 +/- 5.5 vs 159.8 +/- 5.1
mmHg, NS; DBP 97.5 +/- 3.8 vs 98.1 +/- 3.7 mmHg, NS). After 8 weeks of treatment
in the candesartan cilexitil group (SBP 128.3 +/- 5.9 vs 159.8 +/- 5.1 mmHg, p <
0.05; DBP 81.5 +/- 4.1 vs 98.1 +/- 3.7 mmHg, p < 0.05) and in the losartan group
(SBP 151.7 +/- 5.1 vs 159.8 +/- 5.1 mmHg, p < 0.05; DBP 92.7 +/- 3.9 vs 98.1 +/-
3.7 mmHg, p < 0.05) blood pressure values were reduced in the same manner as at
baseline. By comparing the two drugs, candesartan cilexitil proved to have a
better antihypertensive effectiveness (SBP 128.3 +/- 5.9 vs 151.7 +/- 5.1 mmHg, p
< 0.05; DBP 81.5 +/- 4.1 vs 92.7 +/- 3.9 mmHg, p < 0.05). CONCLUSIONS: Our
experience suggests that angiotensin II receptor antagonists may be a therapeutic
remarkable option in patients with chronic renal failure in hemodialysis and
arterial hypertension; the antihypertensive effect seems to be class-specific.
Nevertheless, at least for our data, a better and more rapid antihypertensive
results was obtained with candesartan cilexitil.
PMID- 10687260
TI - [The chemoprevention of breast cancer: an evolving reality].
PMID- 10687261
TI - [The X European Cancer Conference, 12-16 September 1999, Vienna. Carcinoma of the
breast and ovary].
PMID- 10687262
TI - [An angiogenesis study of Dukes' B colonic tumors].
AB - PURPOSE: To evaluate the angiogenesis in Dukes' B colon cancer. PATIENTS AND
METHODS: In 60 patients (age, 39-75 years), the microvessel density and the
relationship between the angiogenesis and other histologic features were
retrospectively evaluated. In an ongoing prospective study, 25 patients have been
enrolled to determine the possible therapeutic implications of VEGF quantitative
analysis. RESULTS: The retrospective portion of this study confirms the
prognostic value of the angiogenesis in terms of recurrences and survival. At
present, no conclusions can be drawn from the prospective portion of the study.
PMID- 10687263
TI - [The clinical usefulness of cyclosporine therapeutic monitoring].
AB - PURPOSE: To review the cyclosporine therapy indications and evaluate determine
the incidence of cyclosporine blood levels outside the therapeutic range in
patients under treatment, to evaluate the practical utility of the drug
monitoring. PATIENTS AND METHODS: The blood concentration of monoclonal
cyclosporine was monitored in 225 patients by FPIA method, using the trough
concentration. RESULTS: 58% of patients had a drug blood level within the
therapeutic range, 26% and 16% of them had respectively, a value below and down
this range. After correcting the drug dosage, 75% and 68% of the patients of the
two subgroups had a cyclosporine blood value within the therapeutic range.
CONCLUSIONS: Cyclosporine is increasingly used in transplant recipients as well
as in patients with other immunological diseases. Since the number of patients,
with inappropriate serum levels of cyclosporine is high, therapeutic monitoring
of blood levels of the drug are of paramount importance.
PMID- 10687264
TI - [The effects of eradication therapy in patients with chronic atrophic gastritis
and seropositivity for anti-HP antibodies and histological negativity for
Helicobacter pylori].
AB - PURPOSE: The present study was undertaken to analyze both whether the elevated
Helicobacter pylori levels in patients with atrophic gastritis without histologic
evidence of Helicobacter pylori would be a sign of an ongoing infection and the
effects of eradication on gastric atrophy. PATIENTS AND METHODS: Twenty patients
(10 M e 10 F; mean age 57.25 SD 12.19) with atrophic gastritis and elevated
Helicobacter pylori titers without histological evidence for Helicobacter-like
organisms were included in the study. Ten patients were randomized into
eradication group (Group 1) (amoxicillin at 500 mg twice a day for 14 days,
metronidazole at 500 mg twice a day for 10 days and omeprazole at 20 mg twice a
day for 20 days) and 10 patients were randomized into the control group (Group
2). For all subjects, serum samples and duplicate biopsy specimens (obtained
endoscopically) were collected prior the study period and approximately 6 months
after the therapy or the follow-up for serum samples and 8 weeks for biopsy
specimens. RESULTS: In the Group 1, the Helicobacter pylori antibody titers
dropped significantly in 73.39% of the patients (p < 0.0001), while in the Group
2, the antibody titers declined only in a patient who received antibiotics during
the study period (p < 0.00006). In both groups, no significant improvement of
atrophic gastritis was observed. CONCLUSIONS: In conclusion, in patients with
atrophic gastritis, the only histological evaluation of Helicobacter-like
organisms colonization in gastric biopsy specimens, appeared in our study to
underestimate the true prevalence of current HP infection and the importance of
the bacterium in the pathogenesis and progression of such disease. Since HP
infection is often associated with an increase of proliferative index, the
eradication of HP could induce a mucosal protective effect against the other
carcinogen factors, although it is extremely unlikely that it can promote the
regeneration of a normal gastric mucosa.
PMID- 10687265
TI - [The fundamental problem of evidence-based medicine: whose "facts" and from what
do the facts come?].
PMID- 10687266
TI - [The clinical use of human recombinant TSH].
AB - The recent cloning of human TSH-beta gene has allowed the production of
recombinant human TSH (rhTSH) by recombinant DNA technology in mammalian cells
(Chinese hamster ovary cells). Studies aimed at biochemical and biological
characterization have shown that rhTSH, unlike pituitary TSH, is highly
sialylated and is biological active in stimulating c-AMP accumulation in FRTL-5
cells. Phase I/II and phase III clinical studies have been performed to evaluate
the safety and efficacy of rhTSH in stimulating radioactive iodine uptake in
patients after total thyroidectomy for differentiated thyroid cancer. In these
patients therapy with thyroid hormones is performed to replace hormone production
and to suppress TSH-stimulated tumor growth. To detect residual or recurrent
cancer, the therapy has to be withdrawn in order to obtain rise in endogenous TSH
to perform a total body scan. rhTSH, as a source of exogenous human TSH, has been
shown as an additional diagnostic tool in the follow-up of patients with thyroid
cancer. Used in patients maintained on thyroid hormone suppressive therapy, rhTSH
enhances the sensitivity of serum Tg testing. Although the sensitivity of scans
obtained after rhTSH administration is slightly lower than that after thyroid
hormone withdrawal, the use of rhTSH avoids the clinical signs and symptom of
hypothyroidism and can be used in selected patients.
PMID- 10687267
TI - [Medical education centers: strategies and purpose].
AB - The introduction of new didactic guidelines, for the graduate degrees in medicine
and allied disciplines, is secondary to the new needs of the National Health Care
System, and in part to the significant developments of science. It is not easy to
meet this challenge. It is likewise not easy to channel coherently the required
changes, with respect to the scientific, clinical and didactic goals.
Paradoxically the same institutions that are in such great need of
transformation, are also a significant part of the existing problem. In many
countries, schools of medicine have developed centers for medical education that
are geared toward the development and growth of students, teachers-tutors, and
patients alike. Medical education has become more global, in an attempt to meet
much needed communication needs, from both ends, teachers and students, as well
as the recipients of care, patients. One major goal of such centers is the
introduction of innovative didactic activities. There is indeed a new tendency
toward the development of methodological tracks aiming at the acquisition and
consolidation of a deeper and broader cultural knowledge. Amongst these
initiatives there is the introduction of an evaluation of the teaching delivered,
as well as the development of a multidisciplinary approach to didactics. The
latter, is a prerequisite of an effective training directed toward the
development of the concept of "team approach", whose ultimate goal is patient
care. In Italy, at the Universita Campus Biomedico, in Rome, one of the first of
such centers of medical education has been developed. Its goal is to be both a
learning organization, as well as a center for both research and clinical
services.
PMID- 10687268
TI - [The Lynch syndrome].
AB - Lynch syndrome is a peculiar disease, accounting for 5% of the total burden of
colon cancer. Characteristics of this disease are autosomal dominant
transmission, early onset, and frequent right colon localization. Diagnostic
criteria, aimed to collaborative studies, are based on these features (so called
Amsterdam criteria). Lynch syndrome has specific biomolecular features
(microsatellite instability); mismatch repair genes have been identified as
responsible of this syndrome. Lynch syndrome causes high risk for extracolonic
malignancies, particularly for endometrial cancer, supposed to be related to
mutation of hMSH2 gene. Another feature of Lynch syndrome tumours is better
survival with respect to sporadic counterpart. Genetic test allows identifying
the state of mutation carriers and selects the patients to submit to screening.
Endoscopic screening has been demonstrated to reduce incidence of colorectal
malignancies in this syndrome.
PMID- 10687269
TI - [Mefloquine and ototoxicity: a report of 3 cases].
AB - We report these cases of high-frequency sensorineural hearing loss and tinnitus,
following malaria prophylaxis with mefloquine (Lariam). Only one patient had
partial remission of hearing loss after suspension of the treatment. In the
remaining two cases the symptomatology remained unchanged. None of the patients
reported improvement of tinnitus. Our experience suggests that a routine
audiologic evaluation, before and after prophylactic use of antimalarial drugs,
is important to monitor potential hearing deficit.
PMID- 10687270
TI - [The successes of cancer chemotherapy. The first cures of advanced-phase
neoplasms].
PMID- 10687271
TI - Consumer-driven cholecystectomy: myth or reality?
AB - OBJECTIVE: To discover if a consumer-driven process is fueling the high rate of
cholecystectomies in the laparoscopic era. DESIGN: A 12-question survey. SETTING:
A 1000-bed, university-affiliated hospital. PATIENTS: Patients admitted for
elective cholecystectomies. MAIN OUTCOME MEASURES: Survey responses suggesting
positive perceptions about laparoscopic cholecystectomy persuade patients to
undergo gallbladder surgery. RESULTS: Patients' symptoms persisted for a mean of
20.7 months, range zero to 204. Mean time between diagnosis and surgery was ten
months, range 0.1-312. Ninety-five and three-tenths percent knew their
gallbladder would be removed; 1.7 percent thought it would be opened to extract
stones. Ninety-one and four-tenths percent correctly identified the procedure as
"laparoscopic cholecystectomy." Fifty and four-tenths percent believed they would
fully recover within a week, 24.1 percent within two weeks, and 14.7 percent
within two days. Eighty-three and two-tenths percent knew laparoscopic
cholecystectomy required less cutting; 33.6 percent thought a laser was used.
Forty-four and eight-tenths percent assumed laparoscopy was the safer method.
Sixty-two and one-tenth percent were referred for surgery by family physicians;
Seven percent approached surgeons themselves. When asked who first suggested the
laparoscopic procedure, 43.1 percent indicated family doctor, 41.4 percent,
surgeon, and three percent requested laparoscopy themselves. Twenty-four and one
tenth percent who delayed surgery despite more than 12 months of symptoms
indicated escalating pain as their reason for seeking surgery now; 0.9 percent
cited the newer procedure. CONCLUSIONS: We found no clear evidence that consumer
awareness of laparoscopy has encouraged more cholecystectomies. Misconceptions
exist about the procedure's execution and safety. Education about risks,
especially bile duct injury, is needed. More frequent referral by family doctors
probably plays a role in the higher incidence of cholecystectomies.
PMID- 10687272
TI - High volume medical web sites.
AB - In 1998, 22 million individuals reported surfing the web for medical information,
and this number will increase to over 30 million by 2000. Fifteen of the highest
volume medical web sites are described in this paper. Sponsorship and/or
ownership of the fifteen sites varied. The government sponsors one, and some are
the products of well-known educational institutions. One site is supported by a
consumer health organization, and the American Medical Association was in the top
15. However, the most common owners are commercial, for-profit businesses.
Attributes of the ideal site were categorized, and include a robust privacy and
disclosure statement with an emphasis on education and an appropriate role for
advertising. The covering of Complementary and Alternative Medicine (CAM) should
be in a balanced and unbiased manner. There has to be an emphasis on knowledge
based evidence as opposed to testimonials, and sources should be timely and
reviewed. Bibliographies of authors need to be available. Hyperlinking to other
web resources is valuable, as even the largest of sites cannot come close to
covering all of medicine.
PMID- 10687273
TI - Methodological summaries in epidemiology: health situation analyses.
PMID- 10687274
TI - New PAHO list 6/67 for tabulation of ICD-10 mortality data.
PMID- 10687275
TI - Case definitions: measles and rubella.
PMID- 10687276
TI - Telomere, telomerase, tumorigenesis and therapy: an overview.
AB - The ends of chromosome in higher eukaryote are termed telomere. The DNAs present
at that part of chromosome is called telomeric DNA. Telomeric DNA consists of
tandemly repeated DNA sequences. The replication of the ends of chromosomes is
not controlled by conventional DNA polymerases rather a special kind of enzyme is
involved in this process. It is a ribonucleoprotein and known as telomerase.
Cells in senescence stage face telomeric crisis that leads to loss of telomeric
ends. Surveillance turns to procancer cells with increased telomerase activity
which is a later consequence. Based on these facts a key diagnostic approach has
been developed for detection of tumour. A novel therapy for tumour repression has
been developed using telomerase inhibitors. However, these inhibitors are very
much effective for solid tumour therapy and conceptually will not work on
hematological malignancies.
PMID- 10687277
TI - Effect of salt stress on nodulation and nitrogen fixation in legumes.
AB - It is now well established that almost all phases of root nodule development in
legumes are adversely affected by saline conditions in the rooting medium. There
is also a general agreement that the rhizobia are more tolerant to salt stress
than the host plant, but they show considerable strain variability in growth and
survival under saline conditions. Inhibitory effect of salinity on nodulation has
been attributed to decrease in rhizobial colonisation and shrinkage and lack of
root hair formation. Salt stress also induces premature senescence of already
formed nodules. Both N2-fixation activity and nodule respiration are inhibited
sharply on exposure of plants to saline conditions. The decrease in N2-fixation
has been ascribed to direct effect on nitrogenase activity or an indirect effect
through decrease in leghemoglobin content, respiratory rate, malate
concentrations in nodules and photosynthate availability. Salinity increases
oxygen diffusion resistance in the nodules and alters their ultrastructure.
Decrease in N2-fixation in nodules under salinity is also accompanied by parallel
decrease in the activity of H2O2-scavenging enzymes like catalase, ascorbate
peroxidase and the level of antioxidants like ascorbic acid. Nodules appear to
undergo osmoregulation under saline conditions by accumulating physiologically
compatible solutes like proline, sugars (pinnitol) and lactic acid. The intensity
of the adverse effects of salinity on nodule functioning depends on plant
species, rhizobial strain, duration of exposure to saline conditions, nature,
concentration and mode of salt application.
PMID- 10687278
TI - Modification of ovine luteinizing hormone subunits with SMPT and its effect on
subunit recombination, immunological activity, receptor binding and steroidogenic
activity.
AB - The increasing use of heterobifunctional cross-linking agents in the design of
defined conjugates for selective targeting and inducing immune response has
prompted us to study the role of epsilon-NH2 group modification of oLH subunits,
their recombination and effect on immunoreactivity, receptor binding and
biological activity. The epsilon-NH2 groups of alpha oLH and beta oLH subunits
were separately modified by using SMPT. The alpha oLH-SMPT modified derivatives
hybridize to beta oLH. Similarly, the beta oLH-SMPT derivatives recombined with
alpha oLH. The recombination was judged by gel filtration chromatography and RP
HPLC analysis. The sequential modification of subunits led to progressive
reduction in immunoreactivity and receptor binding activity. The modification of
six or more epsilon-NH2 groups in alpha oLH although recombine fully with native
beta oLH but failed to react to anti-oLH antibody. Moreover, the steroidogenic
activity was also abolished. Introduction upto four SMPT groups in alpha oLH
compromised immunological and biological activities but further addition of two
or more SMPT groups completely abolished antibody reactivity, receptor binding
and steroidogenic activity indicating the importance of later two amino groups in
the receptor binding and steroidogenic activity. The present investigation
clearly demonstrate that only 1:2-3 molar ratio of oLH subunits:SMPT could
generate the site(s) in the subunits of the oLH that retained reasonable
immunological, receptor binding and biological activity of the hormone.
Therefore, this molar ratio may be used in future for the design and synthesis of
bioeffective hormonotoxins.
PMID- 10687279
TI - Glutathione level and its relation to radiation therapy in patients with cancer
of uterine cervix.
AB - Glutathione functions as an important antioxidant in the destruction of hydrogen
peroxide and lipid peroxides by providing substrate for the glutathione
peroxidase and also promotes the ascorbic acid. Glutathione plays a vital role in
detoxification of xenobiotics, carcinogens, free radicals and maintenance of
immune functions. The study was aimed to determine plasma glutathione as well as
erythrocyte glutathione and glutathione peroxidase in patients with invasive
cervical carcinoma (n = 30) before initiation and after completion of
radiotherapy and subsequently, at the time of first three monthly follow-up
visit. The levels of plasma glutathione, erythrocyte glutathione and glutathione
peroxidase activity were found to be lower in all cervical cancer patients as
compared to age matched normal control women. The study indicates a change in
antioxidant status in relation with the glutathione system among patients with
invasive carcinoma of the uterine cervix. This study also demonstrates the effect
of radiation therapy on this antioxidant system.
PMID- 10687280
TI - Optimization of tumour radiotherapy: Part V--Radiosensitization by 2-deoxy-D
glucose and DNA ligand Hoechst-33342 in a murine tumour.
AB - Radiosensitizing effects of combination of a minor groove DNA ligand, Hoechst
33342, with the glucose analogue and inhibitor of glycolysis, 2-deoxy-D-glucose
(2-DG) have been investigated in Ehrlich ascites tumour (EAT) bearing mice
following focal irradiation of the tumour with 60Co gamma-rays. Treatment-induced
tumour growth delay and tumour free animal survival were evaluated as parameters
of radiation response. Focal irradiation of the tumour with a single fraction of
10 Gy induced a moderate delay in tumour growth but did not lead to complete
regression in any of the tumours. Intravenous administration of H-342 1 hr before
irradiation enhanced radiation-induced growth delay in a dose dependent manner.
Complete regression of the tumour was observed only at a dose of 10 mg/kg body
wt, leading to a cure (tumour free survival for more than 100 days) rate of 55%.
Administration of 2-DG (2 g/kg body wt; i.v.), immediately before irradiation
significantly enhanced radiation-induced growth delay and resulted in a cure rate
of 45%. In combination with this dose of 2-DG (2 g/kg body wt), H-342 at a lower
dose (5 mg/kg body wt) significantly enhanced the cure rate to 66%. H-342 or 2-DG
given alone or in combination at the doses investigated here did not show any
significant effects on the unirradiated tumour.
PMID- 10687281
TI - Effect of angiotensin II on liposome uptake by the rat brain in vivo.
AB - Studies have been performed to assess the possibility of using small unilamellar
liposomes as therapeutic carriers to the brain of hypertensive rats. Rats were
made temporal hypertensive by the infusion of angiotensin II (AII; 15 micrograms
in 1 ml) through their right common carotid artery. Another control group was
infused with physiological saline. Free 125iodine-BSA (125I-BSA) and 125I-BSA
encapsulated liposomes (average diameter approximately equal to 100 nm) were
injected in the tail vein 2 min after the infusion of AII or saline. Plasma
radioactivity was monitored at different times up to 15 min when the cerebral
uptake of 125I-BSA was determined. While a little variation in plasma clearance
pattern of liposomes in hypertensive and control group was noticed, the uptake by
cerebral tissues was markedly higher in hypertensive group. Analysis of
pharmacokinetic parameters in relation to cerebral uptake indicated AII induced a
short term opening of the blood-brain barrier (BBB) resulting in an increased
cerebral uptake. Positively charged liposomes was found to be most effective in
hypertensive state.
PMID- 10687282
TI - Alterations of phosphatidylinositol signal transduction pathway in hepatic
mitochondria following aflatoxin B1 administration.
AB - A single dose of aflatoxin B1 (7 mg/kg body wt) to male rats significantly
stimulated the turnover of mitochondrial phosphoinositides 1-7 hr following its
administration. The elevation of phosphatidylinositol 3,4,5-trisphosphate was
most pronounced whose level continued to be moderately high even at 17 hr period.
The level of diacylglycerol showed a marked increase from 4 hr till 7 hr after
carcinogen treatment, whereas that of inositol 1,4,5-trisphosphate recorded an
increase with a maximum at 7 hr followed by a gradual decrease to near normal
level at 24 hr period. The activation of phosphatidylinositol cycle together with
an activation of PI 3-kinase, whose product PIP3 is known to be involved in
apoptosis might contribute to the early step in the manifestation of toxicity
and/or carcinogenicity.
PMID- 10687283
TI - Liposomes of terbutaline sulphate: in vitro and in vivo studies.
AB - In vitro studies were conducted to understand the comparative drug diffusion
pattern, across artificial membrane, of the drug and of the prepared liposomes of
different liposomal membrane composition. In vivo studies were carried out to
determine the extent and time-course of pulmonary tissue uptake of administered
liposomes containing terbutaline sulphate(TER) on rat lungs. In vitro studies
revealed that the drug released from the prepared liposomes obeys Higuchi's
diffusion controlled model. Different loading doses and release patterns of drug
from the liposomes can be obtained by altering the PC:CHOL ratio and
incorporation of cholesterol was found to reduce permeability of the membrane.
Similarly drug absorption in vivo in rat's lung following intratracheal
instillation, prolonged over 12 hr by liposomal entrapment of TER. The findings
of present investigation indicated that liposomally encapsulated TER can be used
for pulmonary delivery for maximizing the therapeutic efficacy and reducing
undesirable side effects.
PMID- 10687284
TI - Butachlor is cytotoxic and clastogenic and induces apoptosis in mammalian cells.
AB - The ability of butachlor to induce cytotoxicity, clastogenicity and DNA damage
was assessed using Chinese hamster ovary cells (CHO), Swiss mouse embryo
fibroblasts (MEF) and human peripheral blood lymphocytes. A dose and time
dependent loss of viability was evident upon treatment of CHO cells with
butachlor. Cell killing to an extent of 50% was observed when cells were treated
with 16.2 micrograms/ml of butachlor for 24 hr or with 11.5 micrograms/ml for 48
hr. The herbicide induced micronuclei significantly in cultured lymphocytes at 24
and 48 hr of treatment suggesting that it is clastogenic. To understand the
mechanism of cell death caused by butachlor, its effect on DNA strand breaks was
studied in MEF. A concomitant decrease in cell viability was observed with
increase in DNA strand breaks. Agarose gel electrophoresis of DNA from herbicide
treated CHO cells and cytochemical staining indicate the induction of apoptosis
by butachlor.
PMID- 10687285
TI - Characterization and localization of estrogen and progesterone receptors of human
fallopian tube.
AB - The cellular distribution of estrogen and progesterone receptors (ER and PR) in
the human fallopian tube was investigated by immunohistochemical localization
with specific monoclonal antibodies. Nuclear immunostaining was observed. Intense
PR immunostaining was seen in tissues obtained at mid cycle and luteal stages of
the normal menstrual cycle. On the other hand, enhanced staining for ER was seen
in early follicular phase and mid cycle. Menopausal tissues showed negligible
staining for both ER and PR. The ER and PR were characterized for their molecular
size, anatomical distribution and levels during the menstrual cycle and in
menopause. ER protein was present throughout the cycle and also during menopause.
Western blot analysis revealed two forms of ER approximately 66 kDa and a
truncated from approximately 49 kDa in hFT. Presence of A [approximately 90 kDa]
and B [approximately 120 kDa] isoforms of human PR was detected. Follicular and
early luteal tissue possessed relatively high concentration of immunoreactive PR
whereas it was almost undetectable in menopausal tissues. These results suggests
that ER and PR are regulated by the changing ovarian steroid hormones.
PMID- 10687286
TI - Partial cloning and sequencing of a cDNA encoding bonnet monkey (Macaca radiata)
oviduct specific protein.
AB - Based on the complete nucleic acid sequence of human estrogen dependent oviductal
protein and deduced amino acid sequence, potential antigenic site of the protein
was identified. Two oligonucleotide primers were designed to specifically amplify
the region which includes this antigenic site. With the expectation that the
human, and monkey oviductins would have high nucleotide sequence homology, Bonnet
monkey oviduct along with endometrium was obtained on day 5, 9, 12 and 22 of the
cycle. Using RT PCR correct sized PCR product was detected in oviduct taken from
day 9 and 12 of the cycle. PCR product was cloned into pBluescript KS[+] and
nucleic acid sequence determined. A 96% homology to human, baboon and rhesus
monkey estrogen induced glycoprotein, and a 84-88% homology to other mammalian
oviductal protein was noted, thus confirming the authenticity of cDNA clone for
monkey fallopian tube specific protein.
PMID- 10687287
TI - Malignant transformation of Syrian hamster embryo (SHE) cells in culture by
malachite green: an agent of environmental importance.
AB - Malachite green (MG), consisting of green crystals with a metallic lustre, is
very soluble in water and is highly cytotoxic to mammalian cells in culture and
also acts as a liver tumour promoter. In view of its industrial importance and
possible exposure to human beings, MG poses a potential environmental health
hazard. Accordingly, we have studied the effect of MG on the formation of free
radicals using Electron Spin Resonance (ESR) analysis with 5,5-dimethyl-1
pyrroline N-oxide (DMPO) as a spin trapping agent. ESR analysis showed formation
of reactive free radicals during exposure of MG to Syrian hamster embryo (SHE)
cells. As per mechanism-based toxicology in cancer risk assessment, the chemicals
that have the potential to be metabolized to active free radical species could be
human cancer hazards. So, we have investigated the effect of MG on the formation
of Type II and Type III morphologically transformed foci using SHE cell
transformation assay. MG induced dose related transformed foci. Some of these
transformed foci were taken out using selective trypsinisation and established
immortal cell lines. One of these immortal cell lines was characterized
extensively. This immortal cell line showed enhanced DNA synthesis in the form of
BrdU incorporation, increased presence of proliferating cell nuclear antigen
(PCNA), bcl-2 and p53 proteins by immunohistochemistry. When these immortal cells
were injected subcutaneously into nude mice, they developed tumors which were
transplantable and histopathologically sarcomas. The present studies indicate
that MG could be a potential candidate for two year chemical carcinogenesis
rodent bioassays.
PMID- 10687288
TI - Plant beneficial effect of two strains of Proteus vulgaris isolated from tea
plantations.
AB - Two strains of Proteus isolated from tea plantation soil were tested for their
ability to colonise the roots of gram (Cicer arietinum), bean (Phaseolus
radiatus) and mung (Phaseolus mungo) using a gnotobiotic system. Seeds bacterized
with the two strains grew faster and showed significant increase in root and
shoot enlargement of the plants tested. The bioactive fractions obtained from the
culture filtrates and separated through HPLC showed that the plant growth
promoting fractions were not always fungicidal and that the insecticidal fraction
which was found only in RRLJ 16 was not plant growth promoting. These results
suggest that the plant growth promotion effect of the plant beneficial bacteria
may not always be due to disease suppression.
PMID- 10687289
TI - Detection, prevalence, purification and characterization of lecithinase of
Klebsiella pneumoniae.
AB - Lecithinase activity in Klebsiella is a rare trait as out of 208 strains of
Klebsiella belonging to 3 species, viz. K. pneumoniae (168), K. planticola (29)
and K. oxytoca (11), only 4 strains of K. pneumoniae produced lecithinase
positive colonies on egg-yolk-agar. Although cell lysates of 16 K. pneumoniae
yielded positive results for lecithinase assay on egg-yolk-agar, 19 strains were
detected positive for lecithinase with ELISA using anti-lecithinase serum.
Release of up to 52.12% cell-bound lecithinase could be achieved with polymyxin-B
treatment at 100 micrograms/ml concentration. Purified lecithinase was determined
to be a high molecular weight (70 kDa), crystalizable, anionic (pI, 3.5) protein.
It possessed cytolytic, haemolytic and dermonecrotic activities but did not
induce fluid accumulation in rabbit ileal loop or infant mouse guts. It was
inactivated by boiling, trypsin and chymotrypsin treatment and alkaline pH.
Serologically, it was related to lecithinase of Aeromonas caviae and
phospholipase-C of Salmonella.
PMID- 10687290
TI - Cystogenesis of antral follicles induced by dehydroepiandrosterone (DHEA)
stimulates mast cell proliferation and maturation in the house rat (Rattus
rattus) ovary.
AB - Mast cell dynamics has been studied in relation to cystogenesis of ovarian
follicles in the house rat. Immature rats were injected (s.c.) daily with DHEA
(6.0 mg/100 g body weight) and were sacrificed on the day 8, 16 and 24 of the
start of treatment. Ovarian sections of the treated rats had majority of the
antral follicles undergoing atresia or in early stages of cystogenesis.
Completely developed cysts were evident from the ovarian surface after 24 days of
daily treatment. Treatment for 8 days resulted in significant increase in the
number of alcian blue-positive ovarian mast cells. Ovaries after 16 days of DHEA
treatment showed no marked change with regard to the number of total mast cells
per unit area and staining characteristics. However, a significant rise in
ovarian mast cell counts was recorded after 24 days of treatment and most of the
cells contained safranin-positive red granules. This increase was attributed due
to the increase in their number in medulla and stroma around the cystic
follicles.
PMID- 10687291
TI - Studies on anti-ulcer properties of Cissampelos mucronata leaf extract.
AB - The methanolic extract of the leaves of C. mucronata was screened for anti-ulcer
properties using animal models. On isolated guinea pig ileum the extract
inhibited contractions evoked by acetylcholine, histamine and serotonin. The
extract remarkably decreased the propulsive movement of gastrointestinal content.
The extract exhibited significant anti-ulcer activity protecting rats from
indomethacin, histamine and stress-induced ulcers. It inhibited the growth of
both Gram-positive and Gram-negative microorganisms. The oral LD50 value of the
extract in mice was estimated to be 8.5 +/- 0.35 g/kg. The results revealed that
the plant C. mucronata has potential medicinal value as an anti-ulcer agent.
PMID- 10687293
TI - [Summary of the activities of the Academy during the 1998 fiscal year. The Royal
Academy of Medicine of Belgium].
PMID- 10687292
TI - Protective effect of ellagic acid on t-butyl hydroperoxide induced lipid
peroxidation in isolated rat hepatocytes.
AB - Ellagic acid, a plant polyphenol, showed protective effect on isolated rat
hepatocytes against destruction due to lipid peroxide formation induced by t
butyl hydroperoxide in vitro. Ellagic acid inhibited the generation of superoxide
anions and hydroxyl radicals both in enzymic and non enzymic systems, thus
providing protection against oxidative damage.
PMID- 10687294
TI - [Extraordinary births or "the thigh of Jupiter in fertilization in vitro as
passing through the halo of Gargamel"].
PMID- 10687295
TI - [Thyroid and parathyroid surgery under hypnosis: from fiction to clinical
application].
AB - Since 1992, we have used hypnosis routinely in more than 1400 procedures in
plastic surgery. Our clinical success and experience with this technique led us
to test wether hypnosis using active patient collaboration, could be used as an
effective adjunct to conscious intravenous sedation ("hypnosedation", (HS)) for
endocrine surgery, as an alternative to general anaesthesia. On a total of 1905
cervical endocrine surgical procedures performed between 1995 and 1998, 296
thyroidectomies and 33 cervical explorations for hyperparathyroidism were
conducted under HS. Conversion to GA was needed in three cases (0.9%). All
patients having HS reported a very pleasant experience and had significantly less
postoperative pain while analgesic use was significantly reduced in this group.
Hospital stay was also significantly shorter, providing a substantial reduction
of the costs of medical care. The postoperative convalescence was significantly
improved after HS and full return to social or professional activity was
significantly shortened. We conclude that HS is a very efficient technique that
provide physiological, psychological and economic benefits to the patient.
PMID- 10687297
TI - Providing mental health services for a catchment area of 20,000,000
PMID- 10687296
TI - Bookwormburrow.
PMID- 10687298
TI - The works of Charles Rycroft.
PMID- 10687299
TI - Psychiatrist, know from whence you came
PMID- 10687300
TI - Blueprint for a global morality--the work of Robert Rapoport 1924-1996.
AB - Always an idealist, in his last work Robert Rapoport argues that we can achieve a
global ethic in line with the UN Charter and that the inculcation of values must-
and does--start in the home. This reviewer, while in sympathy with his aims,
considers that the obstacles to agreement about ethical issues also need to be
set out.
PMID- 10687301
TI - A red hot issue or a red herring? The scientific credibility of psychoanalysis.
AB - The author charts her personal history in so far as it relates to her interest in
the subject of this paper. It is basically a review article, and the author cites
and comments on publications spanning the years 1895-1996. She concludes that the
scientific status of psychoanalysis is indeed a red hot issue judging from the
numerous publications concerned with it that have appeared over the years. At the
same time the author associates herself with those who consider the issue to be a
red herring, as the terms "psychoanalysis" and "science" mean different things to
different people.
PMID- 10687302
TI - The "Jerusalem syndrome"--fantasy and reality a survey of accounts from the 19th
century to the end of the second millennium.
AB - The so-called "Jerusalem Syndrome" is behavioral phenomena observed in eccentric
and psychotic tourists with religious delusions. A significant number of pilgrims
and tourists have been visiting the Holy City, at least since the beginning of
the 19th century, including some delusionary and eccentric characters. The
authors present a selection of vivid descriptive accounts of such 19th century
visitors, by six local residents and writers about Jerusalem (including one
psychiatrist). It should be noted that those writers already noticed and
documented the so-called syndrome more than a century ago. In comparison to
modern research of the phenomena in contemporary Jerusalem, a striking similarity
in the narrative and the clinical picture emerges. However, based on accumulated
data, the authors suggest that in most cases the religious atmosphere of the city
is not the primary cause for the disorder. The psychotic visitors had set out for
their journey to the Holy City already guided by a delusionary system derived
from their religious belief and cultural background.
PMID- 10687303
TI - Attitudes of Israeli gay students toward other minorities: an exploratory study.
AB - Notwithstanding significant changes in the legal and psychiatric status of
homosexuals, they are still very much victims of public prejudice. It may be
asked, however, how they view other minority groups. The present study compared
the political attitudes of members of a gay political party at the Hebrew
University with a control group of heterosexual university students matched for
demographic characteristics. Homosexual subjects showed significantly more
support for left-wing parties (particularly Meretz). A significant difference was
also found in the party nominated by subjects as most opposed to their own views.
Homosexual subjects showed a much higher rate of opposition to Moledet (a right
wing extremist party) and Shas (a religious party), whereas heterosexual subjects
were more often opposed to left-wing extremist parties. Notwithstanding this
finding, levels of political tolerance for the party most opposed to their own
views was higher among homosexual subjects than among the control group. Whether
these results are related to the minority status of homosexuals, or to the
ideology of the political left is not clear, and is recommended as a topic for
further research.
PMID- 10687304
TI - A survey of the teaching of undergraduate psychiatry in Israel.
AB - BACKGROUND: The 1960-70s saw significant advances in the teaching of psychiatry
in medical schools. Subsequently there have been developments in the structure of
health care and in the methods and goals of medical education. METHOD: All four
departments of undergraduate teaching of psychiatry in Israel and single
departments in Greece, UK and US were asked to respond to a questionnaire about
the structure and content of their teaching program. RESULTS: The amount and
content of preclinical and clinical teaching have not changed over the last two
decades. There has not been a significant "move into the community" and the
nucleus of the program, particularly in Israel, is still in-patient psychiatry.
None of the departments approached are evaluating clinical skills using
performance-based techniques. CONCLUSIONS: The increased awareness of the need
for physicians to have knowledge and skills in psychiatry has not lead to an
increase in the teaching of psychiatry to medical students. Further, the content
of teaching carried out in most of the centers studied does not meet the needs of
physicians, particularly those in primary care, who have to identify and manage a
wide range of psychopathology.
PMID- 10687305
TI - Comments on teaching psychiatry to undergraduates.
PMID- 10687306
TI - Pathoetiology and prevention of NIDDM lessons from the OLETF rat.
AB - The OLETF rat, a genetic model of spontaneous development of NIDDM, exhibits
hyperglycemic obesity with hyperinsulinemia and insulin resistance similar to
that in humans. It is still unclear whether a defect in the beta-cell
proliferation per se is the primary pathogenetic event in this model rat. To
clarify this matter, we used partially pancreatectomized rats as a model. Male
rats of 6 weeks of age were allocated at random to two groups: 70% pancreatectomy
(Px) and sham-pancreatectomy (sham). Each group was divided into 4 subgroups by
the date of sacrifice after surgery. Sustained hyperglycemia was evident in the
Px OLETF rats after surgery. This was associated with insufficient proliferation
of beta-cells, characterized by a decrease in beta-cell labeling with 5-bromo-2'
deoxyuridine in proportion to a decrease in beta-cell mass and reduction in
insulin content in the remnant pancreas. Administration of nicotinamide, however,
ameliorated the sustained hyperglycemia by increasing beta-cell proliferation.
These findings suggest that OLETF rats have a poor capacity for proliferation of
pancreatic beta-cells, and that this change may be the critical pathogenetic
event prior to the onset of overt diabetes. OLETF rats following long-term
caloric restriction and spontaneous exercise training show normal glucose
tolerance accompanied by an increase in GIR as shown by a euglycemic clamp. Both
exercise training and caloric restriction normalize the abnormalities in the
pancreas such as marked hypertrophy of islets and hyperplasia of connective
tissues in islets. It is particularly noteworthy that exercise training
significantly elevated the beta-cell mass/body weight ratio. This evidence
obtained from OLETF rats may be of value when the mechanism of diet and exercise
effects on diabetic patients are considered.
PMID- 10687307
TI - The role of Wilms' tumor genes.
AB - The constitutional chromosomal deletion within the short arm of one copy of
chromosome 11, at band p13, which often correlated with WAGR syndrome consisting
of Wilms' tumor with aniridia, genitourinary malformation, and mental
retardation, provided the first clue to the genetic events in the development of
Wilms' tumor. WT1 gene is encoded by 10 exons, resulting in messenger RNA subject
to a complex pattern of alternative splicing. WT1 gene encodes a zinc finger
transcription factor, which binds to GC-rich sequences and functions as a
transcriptional activator or repressor for many growth factor genes. WT 1 protein
is mainly expressed in developing kidney, testis, and ovary, indicating that it
is involved in the differentiation of genitourinary tissues, all thought to be
the sites of origin of Wilms' tumor. The point mutation of WT1 results in Denys
Drash syndrome. The other Wilms' tumor gene, WT2 at 11p15.5, is linked to
Beckwith-Wiedemann syndrome. The possibility that WT1 is involved in the etiology
of rhabdoid tumor of the kidney was discussed. WT1 is expressed in immortalized
hematologic cells such as EBV-LCL and hematologic malignancies, but not in PBL or
IL-2L. High level WT1 expression in leukemia cells and a poor prognosis are
linked in patients with leukemia, making the gene a novel marker for leukemia
cells. A correlated expression between WT1 and mdr-1 in vincristine resistant
cells indicates a close relation with multi-drug resistance and is a promising
diagnostic marker for chemoresistance in hematologic malignancies.
PMID- 10687308
TI - Role of TNF ligand and receptor family in the lymphoid organogenesis defined by
gene targeting.
AB - The molecular basis of lymphoid organogenesis has recently been elucidated using
gene-targeted mice. Mice deficient in lymphotoxin-alpha (LT alpha) lack lymph
nodes and Peyer's patches. The action of LT alpha in lymphoid organogenesis is
mediated mostly by the membrane form of LT by a mechanism independent of TNF
receptor I (TNFR-I) or II (TNFR-II). Additionally, follicular dendritic cell
(FDC) clusters or germinal centers fail to develop in the spleen of LT alpha
deficient mice. Mice deficient in either TNFR-I or LT beta R also fail to develop
splenic FDC clusters and germinal centers, indicating that signaling through both
TNFR-I and LT beta R is required for the development of these structures. The
mechanisms underlying the defective lymphoid organogenesis in LT alpha-deficient
mice, together with a natural mutant strain, alymphoplasia (aly) mice, which
manifest a quite similar phenotype to LT alpha-deficient mice, were investigated
by generating aggregation chimeras. These studies demonstrate that LT alpha and
the aly gene product together control lymphoid organogenesis with a close
mechanistic relationship in their biochemical pathways through governing distinct
cellular compartments; the former acting as a circulating ligand and the latter
as a LT beta R-signaling molecule expressed by the stroma of the lymphoid organs.
PMID- 10687309
TI - Serum marker KL-6/MUC1 for the diagnosis and management of interstitial
pneumonitis.
AB - Interstitial pneumonitis includes more than a hundred diseases in which
alveolitis is the main manifestation of the affected lung. Symptoms such as dry
cough and exertional dyspnea, fine crackles on chest auscultation, interstitial
infiltrates on chest X-ray films and CT scans, respiratory function tests, and Ga
67 scintigraphy have been used for the diagnosis and the evaluation of disease
activity. However, the poor prognosis of some types of interstitial pneumonitis
has not been improved. We discovered a high molecular weight mucin-like antigen,
designated KL-6, which is also known as MUC1. The serum level of KL-6/MUC1 was
elevated in 70-100% of patients with interstitial pneumonitis, such as pulmonary
fibrosis (either idiopathic or related to collagen-vascular disorders),
hypersensitivity pneumonitis, sarcoidosis, and radiation pneumonitis. The levels
were significantly higher in patients with active disease than in those with
inactive disease. In contrast, patients with noninterstitial lung disease did not
show a significant elevation of KL-6/MUC1. Furthermore, the serum KL-6/MUC1 level
was found to be an early predictive marker of the therapeutic effect of high-dose
corticosteroids in patients with rapidly progressing idiopathic pulmonary
fibrosis. These results indicate that KL-6/MUC1 may be a useful serum marker for
the diagnosis and monitoring of patients with interstitial pneumonitis.
PMID- 10687310
TI - Dietary flavonoids as antioxidants in vivo: conjugated metabolites of (-)
epicatechin and quercetin participate in antioxidative defense in blood plasma.
AB - Flavonoids are present in mainly plant foods and have attracted much attention in
relation to disease prevention. Their antioxidant activity at least partly
accounts for their potential health effect, because oxidative stress leads to a
variety of pathophysiological events. It is essential to know the bioavailability
of flavonoids involving intestinal absorption, metabolic conversion and urinary
excretion, in order to evaluate their in vivo antioxidant activity after intake.
Here (-)-epicatechin and quercetin were selected as typical flavanol- and
flavonol-flavonoids present in vegetables, fruits and tea. Our rat study suggests
that their metabolic conversion begins in the intestinal mucosa where the
activity of uridine-5'-diphosphoglucuronosyltransferase (UGT) is at its highest.
Both flavonoids accumulated mostly as glucuronide and sulfate conjugates in blood
plasma after oral administration. No intact quercetin was found in the
circulation. However, on the oral administration of these flavonoids, the
antioxidative ability of rat plasma was enhanced indicating that conjugated
metabolites participate in the antioxidant defense in blood plasma. Therefore,
the intake of vegetables, fruits and tea rich in flavonoids may help to prevent
oxidative damages in the blood.
PMID- 10687311
TI - Effects of smoking on serum lipid and lipoprotein concentrations and lecithin:
cholesterol acyltransferase activity.
AB - Cigarette smoking is one of the major risk factors for cardiovascular disease.
The mechanism responsible for this association is still unknown. We measured the
activity of lecithin: cholesterol acyltransferase (LCAT), a key factor in the
esterification of plasma cholesterol and reverse cholesterol transport, and the
levels of lipids and apolipoproteins in the serum of 27 cigarette smoking and 31
non-smoking (control) men. We could not find any significant difference among
these parameters between the groups. Serum LCAT activity was lower in smokers,
but the difference was statistically nonsignificant. We also classified the two
groups in respect to their serum lipid levels as hyper- and normolipidemic, we
observed that normolipidemic-smokers had lower (p < 0.05) high density
lipoprotein-cholesterol (HDL-C) and HDL-ester cholesterol levels compared to the
normolipidemic-nonsmokers. While there were no any significant differences
between hyperlipidemic-smokers and nonsmokers with respect to any of the
parameters. In the end we have got the idea that smoking seems to affect HDL-C
and HDL-ester cholesterol levels in the normolipidemic-smokers group, only, Also,
LCAT activity tended to be lower in smokers compared to nonsmokers.
PMID- 10687312
TI - The effect of a newly developed ointment containing eicosapentaenoic acid and
docosahexaenoic acid in the treatment of atopic dermatitis.
AB - While various therapeutic modalities have been tried for atopic dermatitis (AD),
numerous obstinate cases exist in which sufficient effects cannot be obtained.
Therefore, we developed and prepared an ointment containing docosahexaenoic acid
and eicosapentaenoic acid as a topical therapeutics for AD. We applied this
ointment to 64 patients with AD (aged between 2 months and 29 years) who showed
poor responses to conventional therapies and obtained satisfactory results. This
ointment is considered a new topical preparation for AD.
PMID- 10687313
TI - Vital immunohistochemical staining for a novel method of diagnosing micro-cancer.
Examination of immunohistochemical staining of non-fixed fresh tissue.
AB - It becomes possible to establish a novel diagnostic method for micro-cancer by
modulating the signals from the lesion, if lesions can be labeled with substances
which can be detected by video endoscopy. The authors have already succeeded in
synthesizing indocyanine green (ICG) derivatives for a fluorescent labeling
substance which emits near-infrared rays. Before the antibodies labeled by these
substances can be used, it is necessary to establish a method of vital
immunohistochemical staining. So, we investigated the responses of antibodies
exposed to non-fixed fresh tissue specimens as a basic study on vital
immunohistochemical staining. The responses of fresh esophageal and gastric
specimens (biopsied or surgically resected) to immunohistochemical staining with
anti-epithelial membrane antigen (EMA) antibodies under various conditions using
the ABC method were examined. These tissue specimens were stained
immunohistochemically, and incubated with anti-EMA antibodies for 10 and 30
minutes (esophagus), and for 60 and 120 minutes (stomach) at 37 degrees C. These
results suggest that vital immunohistochemical staining is possible under optimum
conditions. If an infrared fluorescent endoscopy catching this excited
fluorescence can be developed, it will be possible to establish a new endoscopic
diagnostic method on the basis of vital immunohistochemical staining.
PMID- 10687314
TI - Molecular genetic analysis of pyridoxine-nonresponsive homocystinuric siblings
with different blood methionine levels during the neonatal period.
AB - Two mutations in the cystathionine beta-synthase (CBS) gene were found in two
Japanese siblings with pyridoxine non-responsive homocystinuria who had different
methionine levels in their blood during the neonatal period. Both patients were
compound heterozygotes of two mutant alleles: one had an A-to-G transition at
nucleotide 194 (A194 G) that caused a histidine-to-arginine substitution at
position 65 of the protein (H65R), while the other had a G-to-A transition at
nucleotide 346 (G346A) which resulted in a glycine-to-arginine substitution at
position 116 of the protein (G116R). The two mutant proteins were separately
expressed in Escherichia coli, and they completely lacked catalytic activity.
Despite their identical genotypes and almost equal protein intake, these siblings
showed different levels of blood methionine during the neonatal period,
suggesting that the level of methionine in blood is determined not only by the
defect in the CBS gene and protein intake, but also by the activity of other
enzymes involved in methionine and homocysteine metabolism, especially during the
neonatal period. Therefore, high-risk newborns who have siblings with
homocystinuria, even if the level of methionine in their blood is normal in a
neonatal mass screening, should be followed up and diagnosed by an assay of
enzyme activity or a gene analysis so that treatment can be begun as soon as
possible to prevent the development of clinical symptoms. In addition, a new,
more sensitive method for the mass screening of CBS deficiency in neonates should
be developed.
PMID- 10687315
TI - Fluoromicroscopic detection of myc-tagged GLUT4 on the cell surface. Co
localization of the translocated GLUT4 with rearranged actin by insulin treatment
in CHO cells and L6 myotubes.
AB - We earlier developed a novel method to detect translocation of glucose
transporter type 4 (GLUT 4) directly, quantitatively and simply using c-MYC
epitope-tagged GLUT4 (GLUT4myc) Kanai F, Nishioka Y, Hayashi H, Kamohara S,
Todaka M, Ebina Y: J Biol Chem 268: 14523-14526, 1993). We further developed the
method to visualize GLUT4myc on the cell surface++ by fluorescence microscope
using a highly sensitive immunochemical detection system in tissue culture cells
stably expressing GLUT4myc. The translocation of GLUT4myc was observed on
stimulation with insulin in 3T3-L1 adipocytes, CHO cells and L6 myotubes stably
expressing GLUT4myc. Platelet-derived growth factor (PDGF), norepinephrine and
bradykinin also triggered GLUT4 translocation in CHO-GLUT4myc cells stably
expressing each receptor. To observe the distribution of GLUT4 and actin after
insulin treatment, double staining for GLUT4myc and actin was performed.
Translocated GLUT4myc on the cell surface was co-localized with rearranged actin
in CHO cells and L6 myotubes. This result suggests that a correlation exists
between GLUT4 translocation and actin rearrangement.
PMID- 10687316
TI - The effects of desferrioxamine on thrombus formation in injured microvessels of
the rabbit ear.
AB - We investigated the effects of the iron chelator desferrioxamine (DFX) on
thrombus formation in the arterioles and venules of the rabbit ear chamber.
Thrombi were induced by irradiation with filtered light in combination with a
fluorescent dye. The occlusive thrombus formation time was significantly extended
by DFX. The morphological composition of thrombi in the arterioles and venules
was different. In the arterioles, the thrombi consisted of platelet aggregation,
but in the venules, platelets and leukocytes accumulated on the endothelium. This
suggest that hydroxyl radicals may be important mediators in this model, as DFX
is known as a hydroxyl radical scavenger. Furthermore, the components of thrombi
in the arterioles and venules in the skin microvascular system may be different.
PMID- 10687317
TI - Effect of intermittent liver ischemia on outcome in patients with hepatocellular
carcinoma on liver cirrhosis.
AB - The influence on postoperative liver function of intermittent normothermic
hepatic ischemia in cirrhotic patients was studied retrospectively. The mean
total ischemia time was 88 (range 30-140) minutes in the hemi-hepatic occlusion
group, and 68 (range 10-187) minutes in the total occlusion group. There were no
operative deaths due to hepatic failure. Postoperative liver function improved
within 1 week of the operation. There was no significant difference in the
incidence of postoperative complications between the groups. Thus normothermic
hepatic ischemia is tolerated for up to 180 minutes in the cirrhotic liver when
an intermittent technique (15 minutes clamped and 5 minutes unclamped) is used.
PMID- 10687318
TI - Late recurrence of acinic cell carcinoma of the parotid gland.
AB - Acinic cell carcinoma of the salivary glands is a rare cancer representing a low
grade malignancy. The recurrence of a tumor is sometimes encountered, usually
within 5 years of initial operation. We describe an unusual recurrence after a
long interval following primary surgery. In 1987, a 60-year-old woman underwent
excision of a mass in the superficial lobe of the right parotid gland under the
preoperative diagnosis of a benign tumor. A histologic diagnosis of acinic cell
carcinoma was made by examining sections from the resected mass. The patient
noted several small nodules in the right parotid region in 1995, but she did not
visit our clinic until 1998 when tenderness developed. A locally recurrent tumor
and cervical lymph nodes containing metastases were resected and postoperative
radiotherapy was given 11 years after the first operation. At least 10 years of
follow-up may be necessary for patients with acinic cell carcinoma because of
slow-tumor growth.
PMID- 10687319
TI - The need for ketamine.
PMID- 10687320
TI - Re: Clinical experience with oral ketamine.
PMID- 10687321
TI - Development and validation of the cancer fatigue scale: a brief, three
dimensional, self-rating scale for assessment of fatigue in cancer patients.
AB - We herein describe the development and validation of the Cancer Fatigue Scale
(CFS) for assessment of fatigue in cancer patients. We designed this scale
specifically to reflect the nature of fatigue experienced by cancer patients, by
using factor analysis; the CFS is a 15-item scale composed of 3 subscales
(physical, affective, and cognitive subscales). Three hundred seven cancer
patients participated in the validation phase. Construct validity, confirmed by
repeating factor analysis, was good. Convergent validity, confirmed by a
correlation between CFS and a visual analogue scale for fatigue, was also shown
to be good (r = 0.67, P < 0.001). The CFS had good stability (average test-retest
reliability r = 0.69, P < 0.001) and good internal consistency (Cronbach's alpha
coefficient for all 15 items = 0.88). The present study indicates that the CFS is
a brief, valid, and feasible measure of fatigue for use with cancer patients.
PMID- 10687322
TI - Is the presence of dyspnea a risk factor for morbidity in cancer patients?
AB - Data collected from six home palliative care teams in Ireland were analyzed to
determine the prevalence of dyspnea in the population studied and to identify
factors associated with the presence of dyspnea that might impact on future care.
The prevalence of mild, moderate, or severe dyspnea, as measured by the Support
Team Assessment Schedule (STAS), fell from 39% at referral in 327 evaluable
patients to 23%. The presence of dyspnea at referral was positively correlated
with severity of patient spiritual distress (Spearman rho = 0.110, P = 0.042) and
weakness (Spearman rho = 0.105, P = 0.008) at referral. In analysis of
contingency tables, dyspnea was also significantly associated with low patient
(chi 2 9.5, P = 0.002) and family (chi 2 50.78, P < 0.001) well-being, high staff
anxiety (chi 2 4.14, P = 0.04), male sex (chi 2 8.9, P = 0.003), a diagnosis of
lung cancer (chi 2 59.88, P < 0.001), and dying in hospital rather than hospice
or nursing home (chi 2 18.03, P = 0.001). In adjusting for covariates using a
logistic regression analysis, however, only the presence of low family well
being, a diagnosis of lung cancer, and increased likelihood of a hospital death
remained significantly associated with the presence of dyspnea at referral. These
data suggest that the presence of dyspnea may be associated with increased family
distress, which may influence place of death.
PMID- 10687324
TI - The safety and efficacy of a single dose (500 mg or 1 g) of intravenous magnesium
sulfate in neuropathic pain poorly responsive to strong opioid analgesics in
patients with cancer.
AB - Neuropathic pain may respond poorly to morphine and is often difficult to
relieve. Recent attention has been drawn to the role of the N-methyl-D-aspartate
(NMDA) receptor in the potentiation of neuropathic pain. Magnesium is known to
block the NMDA receptor. It reduces the neuropathic pain response in animals, and
attenuates postoperative pain and migraine in humans. We have examined the
safety, tolerability, and efficacy of two intravenous doses of magnesium sulfate
in 12 patients with neuropathic pain due to malignant infiltration of the
brachial or lumbosacral plexus. The first six patients received 500 mg, the
remainder 1 g. Apart from a mild feeling of warmth at the time of the injection,
both doses were well tolerated. After receiving 500 mg, three patients
experienced complete pain relief and two experienced partial pain relief for up
to 4 hours duration; pain was unchanged in one patient. After receiving 1 g, one
patient experienced complete relief and four experienced partial pain relief of
similar duration; pain was unchanged in one patient. Intravenous magnesium
sulfate in these doses appears to be safe and well tolerated. A useful analgesic
effect may be obtained in some patients and further evaluation is warranted.
PMID- 10687323
TI - Role of octreotide, scopolamine butylbromide, and hydration in symptom control of
patients with inoperable bowel obstruction and nasogastric tubes: a prospective
randomized trial.
AB - Bowel obstruction may be an inoperable complication in patients with end-stage
cancer. Scopolamine butylbromide (SB) and octreotide (OCT) have been successfully
used with the aim of reducing gastrointestinal (GI) secretions to avoid placement
of a nasogastric tube (NGT); however, there have been no comparative studies
concerning the efficacy of these drugs. Furthermore, there is little information
about the role played by parenteral hydration in symptom control of these
patients. In a prospective trial that involved all 17 inoperable bowel-obstructed
patients presenting to our services with a decompressive NGT, patients were
randomized to OCT 0.3 mg/day or SB 60 mg/day for 3 days through a continuous
subcutaneous infusion. Clinical data, survival time, and the time interval from
the first diagnosis of cancer to the onset of inoperable bowel obstruction were
noted. The intensity of pain, nausea, dry mouth, thirst, dyspnea, feeling of
abdominal distension, and drowsiness were assessed by means of a verbal scale
before starting treatment with the drugs under study (T0) and then daily for 3
days (T1, T2, T3). Moreover, daily information was collected regarding the
quantity of GI secretions through the NGT, the oral intake of fluids, the
quantity of parenteral hydration, and the analgesic therapy used. The NGT could
be removed in all 10 home care and in 3 hospitalized patients without changing
the dosage of the drugs. OCT significantly reduced the amount of GI secretions at
T2 (P = 0.016) and T3 (P = 0.020). Compared to the home care patients, the
hospitalized patients received significantly more parenteral hydration (P =
0.0005) and drank more fluids (P = 0.025). There was no difference in the daily
thirst and dry mouth intensity in relation to the amount of parenteral hydration
or the treatment provided (OCT or SB). Independent of antisecretory treatment,
the patients receiving less parenteral hydration presented significantly more
nausea (T0 P = 0.002; T1 P = 0.001; T2 P = 0.003; T3 P = 0.001) and drowsiness at
T3 (P < 0.5). Pain relief was obtained in all 17 patients and only two patients
required an increase in morphine dose at T1. All patients with inoperable
malignant bowel obstruction should undergo treatment with antisecretory drugs so
as to evaluate the possibility of removing the NGT. When a more rapid reduction
in GI secretions is desired, OCT should be considered as the first choice drug.
Parenteral hydration over 500 ml/day may reduce nausea and drowsiness.
PMID- 10687325
TI - A chart review of the ordering and documentation of urine toxicology screens in a
cancer center: do they influence patient management?
AB - Urine toxicology screens (UTSs) may be useful in the diagnosis or monitoring of
patients with established or suspected substance abuse. In the medically ill,
including those with cancer, the test may help clinicians manage therapy with
controlled prescription drugs. To describe the current use of UTSs in a cancer
center, the medical records of 111 patients who underwent UTS were reviewed.
These 111 patients were randomly selected from a group of 215 patients who
underwent screening between January 1, 1990 and December 31, 1994 (a period
during which over 80,000 admissions occurred). Fifty-six of the 111 patients had
evidence of one or more illicit drugs, a prescription medication that had not
been ordered, or alcohol; 50 patients had negative screens. The likelihood of a
positive UTS was higher if the patient had human immunodeficiency virus (HIV)
infection (100% versus 46.6%) or was undergoing treatment for chronic
nonmalignant pain (100% versus 43.9%). Documentation of the UTS in the medical
record was infrequent: 37.8% of the charts listed no reason for obtaining the
test and the ordering physician could not be identified in 29% of the records.
Eighty-nine percent of the records did not contain a subsequent mention of the
result of the UTS. The result was more likely to lead to a documented outcome
when it was positive rather than negative (14.3% versus 0%). These results
suggest that UTSs are used infrequently in the tertiary care oncology center. The
documentation surrounding the ordering and subsequent use of the test in patient
management is unsystematic. The appropriate use and documentation of UTSs, like
substance abuse issues in general, should be a focus of staff education and
quality improvement efforts.
PMID- 10687326
TI - Topical capsaicin in the management of HIV-associated peripheral neuropathy.
AB - Distal symmetrical peripheral neuropathy (DSPN) is a particularly distressing
pain syndrome associated with human immunodeficiency virus (HIV) disease.
Capsaicin has been found to be effective in relieving pain associated with other
neuropathic pain syndromes, and is mentioned as a possible topical adjuvant
analgesic for the relief of DSPN. This multicenter, controlled, randomized,
double-masked clinical trial studied patients with HIV-associated DSPN and
compared measures of pain intensity, pain relief, sensory perception, quality of
life, mood, and function for patients who received topical capsaicin to the
corresponding measures for patients who received the vehicle only. Twenty-six
subjects were enrolled in the study. At the end of 1 week, subjects receiving
capsaicin tended to report higher current pain scores than did subjects receiving
the vehicle (Mann-Whitney test; P = 0.042). The dropout rate was higher for the
capsaicin group (67%) than for the vehicle group (18%) (chi 2 test of
association; P = 0.014). There were no other statistically significant
differences between the capsaicin and vehicle groups with respect to current
pain, worst pain, pain relief, sensory perception, quality of life, mood, or
function at study entry or at any time during the 4-week trial. These results
suggest capsaicin is ineffective in relieving pain associated with HIV-associated
DSPN.
PMID- 10687327
TI - Characteristics of methadone maintenance patients with chronic pain.
AB - Chronic pain patients who have limited access to opioids may be redirected to
methadone maintenance centers for management of their pain. Unfortunately, little
information exists on the incidence and characteristics of methadone maintenance
patients with chronic pain. The aim of this study was to survey individuals at
methadone maintenance centers in order to determine the prevalence of chronic
pain and to explore differences between patients with and without pain in this
treatment setting. Of 248 participants interviewed at three centers, 152 (61.3%)
reported chronic pain. Compared with patients without pain, those with pain
reported significantly more health problems (P < 0.001), more psychiatric
disturbance (P < 0.05), more prescription and nonprescription medication use (P <
0.001), and greater belief that they were undertreated (P < 0.001); 44% of those
with pain believed that opioids prescribed for their pain had led to an addiction
problem. Most of the methadone maintenance patients stated that they had always
required some substance (alcohol or opioids) to feel normal. These results raise
many questions about chronic-pain treatment policies and resources for persons
with a history of substance abuse. Further investigations are needed to define
the needs of this population and to improve their access to effective pain
management.
PMID- 10687328
TI - Judging the effectiveness of analgesia for children and adolescents during vaso
occlusive events of sickle cell disease.
AB - The effectiveness of analgesia during sickle cell crisis was examined in this
descriptive, exploratory study. Pain scores (using the African-American Oucher
and the Adolescent Pediatric Pain Tool) and analgesics administered were examined
during a 2-hour observation/interview in the hospital while children/adolescents
with sickle cell disease (SCD) experienced a vaso-occlusive episode (VOE). A
convenience sample of twenty-one 6- to 16-year olds with SCD was included.
Evidence indicated that 15 of the 21 children in the sample were in moderate to
severe pain during their interviews, indicating that the analgesics did not
effectively control their pain. Most participants (17) had received nalbuphine as
the primary analgesic by intravenous infusion drip and/or patient-controlled
analgesia pump. Many reasons were identified for the inadequate analgesia. The
results suggested that the pain of SCD is very complex, requiring continuous
adjustment of comfort measures, especially analgesics. More research is needed to
examine pain control in children with SCD.
PMID- 10687329
TI - Subcutaneous emphysema in advanced cancer.
AB - Spontaneous subcutaneous emphysema is a rare and usually benign entity that may
occasionally be symptomatic. We report a case of a patient with advanced cancer
who developed extensive but asymptomatic subcutaneous emphysema shortly before
death. Perforation of the lower gastrointestinal tract, perhaps as a result of
straining due to severe unrelieved constipation or due to fistula formation, is
suspected to have been the mechanism. The causes, treatment, and implications for
management of this condition are discussed.
PMID- 10687330
TI - NMDA-Receptor Antagonists: Evolving Role in Analgesia. Proceedings of a meeting.
New York City, New York, USA. May 1, 1999.
PMID- 10687331
TI - Update on the neurophysiology of pain transmission and modulation: focus on the
NMDA-receptor.
AB - Pain is detected by two different types of peripheral nociceptor neurons, C-fiber
nociceptors with slowly conducting unmyelinated axons, and A-delta nociceptors
with thinly myelinated axons. During inflammation, nociceptors become sensitized,
discharge spontaneously, and produce ongoing pain. Prolonged firing of C-fiber
nociceptors causes release of glutamate which acts on N-methyl-D-aspartate (NMDA)
receptors in the spinal cord. Activation of NMDA receptors causes the spinal cord
neuron to become more responsive to all of its inputs, resulting in central
sensitization. NMDA-receptor antagonists, such as dextromethorphan, can suppress
central sensitization in experimental animals. NMDA-receptor activation not only
increases the cell's response to pain stimuli, it also decrease neuronal
sensitivity to opioid receptor agonists. In addition to preventing central
sensitization, co-administration of NMDA-receptor antagonists with an opioid may
prevent tolerance to opioid analgesia.
PMID- 10687332
TI - NMDA-receptor antagonists and opioid receptor interactions as related to
analgesia and tolerance.
AB - A model proposing that N-methyl-D-aspartate (NMDA) receptor and opioid receptor
mechanisms overlap and interact within the same dorsal horn nociceptive neurons
makes several predictions. First, hyperalgesia should be associated with opioid
tolerance. Second, both hyperalgesia and tolerance to opioid-analgesia should be
blocked by an NMDA-receptor antagonist. Results from our laboratory and others
support these predictions and point to several clinical implications. One is
that, in addition to preventing tolerance and dependence, combining NMDA-receptor
antagonists with both opioid and nonopioid analgesics may increase their
analgesic potency. Preclinical animal studies demonstrate these advantages and
underscore the practicality of the combined administration of nontoxic NMDA
receptor antagonists with various types of analgesic drugs.
PMID- 10687333
TI - Chronic pain: challenges in the assessment and management of cancer pain.
AB - Assessing and managing pain while caring for the whole patient is a challenge for
physicians. Barriers to pain management include clinician-, patient-, and health
system-related issues. The traditional model of care is focused on disease
specific treatments. If these treatments fail, the focus shifts to palliation. A
new model of care integrates disease-specific treatments with palliative care and
rehabilitation. This model includes prevention and treatment of suffering. An
essential element of this model is evaluation of the patient's concerns about the
future and fear. Treating patient pain with quality pain management and
palliative care involves a holistic pain assessment and management strategy.
PMID- 10687334
TI - Current pharmacotherapy of chronic pain.
AB - Advances in basic and clinical research have greatly expanded the options for
analgesic pharmacotherapy. There are three broad categories of analgesic
medications: (1) nonopioid analgesics, which includes the nonsteroidal anti
inflammatory drugs (NSAIDs), acetaminophen, dipyrone, and others; (2) a diverse
group of drugs known as the "adjuvant analgesics," which are defined as "drugs
that have primary indications other than pain but may be analgesic in selected
circumstances;" and (3) opioid analgesics. The advent of highly selective COX-2
inhibitors has generated excitement because of the possibility that these new
NSAIDs will be much safer than previous COX inhibitors. However, the cost-benefit
of using these relatively more expensive drugs versus other NSAIDs plus gastro
protective therapies needs to be determined. Adjuvant analgesics can be grouped
into four major classes according to their use: multipurpose, neuropathic pain,
musculoskeletal pain, and cancer pain. There has been a dramatic increase in the
number of these drugs during the past two decades and they now play an important
role in the management of chronic pain. Pain specialists are now using opioids
for chronic nonmalignant pain in addition to the traditional use for acute and
cancer pain. This change in practice evolved from recognition that selected
patients with chronic noncancer-related pain can experience sustained analgesia
and function better with these drugs, without developing an addictive disorder.
The combination of opioids and other drugs, such as an N-methyl-D-aspartate
receptor antagonist, may improve the balance between analgesia and adverse
effects.
PMID- 10687335
TI - NMDA-receptor antagonists in neuropathic pain: experimental methods to clinical
trials.
AB - Recent clinical data suggest that chronic pain due to nerve or soft tissue injury
may result in the sensitization of the central nervous system, mediated in part
by the excitatory amino acids, glutamate and aspartate. Only a handful of N
methyl-D-aspartate antagonists are clinically available. These include ketamine,
dextromethorphan, memantine, and amantadine, as well as three clinically used
opioids (methadone, dextropropoxyphene, and ketobemidone). This review summarizes
the single-dose efficacy of the first two compounds in the treatment of
experimental and neuropathic pain. In all examples presented here, NMDA-receptor
antagonists with affinity at the phencyclidine site have been shown to modulate
pain and hyperalgesia but are limited by dose-limiting side effects. Thus,
provided their therapeutic ratio is favorable, NMDA-receptor antagonists may be
effective in the treatment of some types of chronic pain.
PMID- 10687336
TI - Abuse potential of morphine/dextromethorphan combinations.
AB - The potentiation of morphine analgesia by dextromethorphan raises the issue of
whether dextromethorphan also potentiates those actions of morphine that lead to
abuse. Clinical pharmacology experiments indicated that dextromethorphan does not
potentiate the euphorigenic and miotic actions of morphine. Morphine suppresses
the dysphoric action of dextromethorphan. A second set of experiments indicated
that dextromethorphan does not alter the response to naloxone-precipitated
withdrawal. In a third set of experiments, dextromethorphan did not alter the
morphine-induced depression in the slope of the increase in minute volume in
response to breathing increased CO2. In contrast to potentiation of analgesia,
dextromethorphan does not enhance the euphorigenic, physical dependence, and
respiratory depressant actions of morphine. These findings indicate that
dextromethorphan does not enhance the abuse potential of morphine and that the
potentiation of analgesia appeared to be selective.
PMID- 10687337
TI - MorphiDex pharmacokinetic studies and single-dose analgesic efficacy studies in
patients with postoperative pain.
AB - MorphiDex (MS:DM), a 1:1 (weight:weight) ratio of morphine sulfate (MS) to
dextromethorphan hydrobromide (DM), is under clinical development for the
treatment of moderate to severe pain. The enhancement of MS analgesia by DM is
due to a pharmacodynamic interaction, not an effect on MS blood levels or a
pharmacokinetic interaction between MS and DM, or their metabolites. Peak blood
levels were achieved at approximately 1 hour, similar to MS in solution,
resulting in a rapid onset of effect. As the dose was increased, dose
proportionality was linear. Food reduced the peak concentration in blood (Cmax)
but not the extent of the absorption. Single-dose, double-blind, placebo
controlled studies in patients suffering from moderate to severe postoperative
pain after third-molar oral surgery or orthopedic surgery demonstrated a
significantly greater analgesic effect for MS:DM over MS alone with an 8-hour
duration of effect. MS:DM is an effective treatment of moderate to severe pain.
PMID- 10687338
TI - MorphiDex (MS:DM) double-blind, multiple-dose studies in chronic pain patients.
AB - Preclinical and double-blind single-dose placebo-controlled studies demonstrated
that MorphiDex (MS:DM), a 1:1 ratio of morphine sulfate (MS) to dextromethorphan
hydrobromide (DM), provides significantly greater analgesia than an equal dose of
immediate release MS, with a faster onset, and a duration of > or = 8 h. The
analgesic effect of MS:DM compared to MS was evaluated in 2 double-blind,
multiple-dose studies in 321 patients with cancer and other chronic pain: a
crossover study that consisted of two 2-wk periods and a 4-wk parallel study. As
specified in the study protocols, patients took sufficient MS or MS:DM to achieve
satisfactory pain control. In the crossover study, the MS:DM group required half
as much morphine as the MS group to achieve satisfactory pain control (80 mg and
162 mg, respectively). The interval between doses and the time from the last dose
of the day to the first dose of the next day were significantly longer for MS:DM
compared to MS. In the parallel study, MS:DM also provided pain control at a
significantly lower dose. After four weeks of treatment, the mean daily dose of
MS increased, while there was little change in the MS:DM mean daily dose (P =
0.025) to maintain satisfactory pain control. More patients preferred MS:DM to
run-in MS than preferred MS to run-in MS (P = 0.026). The addition of DM to MS
did not increase the incidence of adverse events, which were those commonly
associated with opioid use. These studies confirm that MS:DM provides
satisfactory pain relief but at a significantly lower morphine daily dose.
PMID- 10687339
TI - Morphine with dextromethorphan: conversion from other opioid analgesics.
AB - MorphiDex, a 1:1 combination of dextromethorphan and morphine, provides
satisfactory pain control at a significantly lower morphine daily dose. To
determine the appropriate conversion regimens from other oral or transdermal
opioid analgesics to MorphiDex (MS:DM), 592 patients with moderate to severe
chronic pain requiring daily use of opioid analgesics were enrolled in this
multicenter, open-label study. Patients were instructed to use MS:DM as needed to
achieve satisfactory pain control. Overall, study patients took a significantly
lower morphine daily dose (P = 0.0001), and a higher percentage (P = 0.0001)
rated therapy with MS:DM as "very good" or "excellent" compared to their prestudy
opioid. The mean daily dose of MS:DM remained level throughout a 10 month study
extension period, suggesting that MS:DM may inhibit the development of tolerance
to morphine. Most of the adverse events observed with MS:DM were those commonly
reported with opioid therapy and were mild to moderate in severity. MS:DM appears
safe and effective in treating moderate to severe chronic pain.
PMID- 10687340
TI - Long-term safety of MorphiDex.
AB - More than 2200 subjects were enrolled in the MorphiDex (MS:DM) development
program, with a 1:1 (weight:weight) ratio of morphine sulfate (MS) to
dextromethorphan hydrobromide (DM). Of the 1400 subjects exposed to MorphiDex,
more than 350 subjects were treated for at least 6 months, and over 200 subjects
were treated for a year or longer. The clinical population comprised an
approximately equal number of men (46.2%) and women (53.8%), ranging in age from
16 to 96 years, and mostly Caucasian (91.8%). The most frequent (54.8%) daily
dose of MorphiDex for subjects enrolled in the clinical program was 120 mg or
less. Slow DM metabolizers took significantly lower daily doses of MorphiDex than
rapid metabolizers without a significant difference in the incidence of adverse
events. Plasma bromide concentrations were low and showed a wide margin of safety
for both slow and rapid DM metabolizers. There were no clinically significant
treatment-related changes in clinical laboratory tests, neurological
examinations, or vital signs. The most common adverse events seen in the multiple
dose controlled studies were nausea, dizziness, vomiting, somnolence,
constipation, confusion, asthenia, headache, and pruritus. With long-term
treatment, the prevalence of adverse events was greatest during the first month
of MorphiDex exposure and then decreased over time. The incidence of constipation
remained fairly constant over time.
PMID- 10687341
TI - Enhancing opioid analgesia with NMDA-receptor antagonists: clarifying the
clinical importance. A roundtable discussion.
PMID- 10687342
TI - [Different anamnestic approaches in the treatment of dyspepsia. Quicker access to
gastroscopy should make the diagnosis easier].
PMID- 10687343
TI - [Helicobacter pylori--the discovery still of current interest in the new
millenium. Both good and bad bacteria in the stomach?].
PMID- 10687344
TI - [Significant undertreatment of high cholesterol level in ischemic heart disease].
AB - Lipid and lipoprotein analysis was performed in 127 consecutive patients with
stable incapaciting angina referred by cardiologists for coronary angiography
(mean waiting time, 121 days). Ninety-four per cent of the patients manifested
evidence of myocardial ischaemia at exercise testing, or had had earlier
myocardial infarction or earlier revascularisation with angioplasty or bypass
surgery. Despite the well-known results of the large statin trials in secondary
prevention (4S and CARE), only a third of the patients had LDL cholesterol levels
in accordance with Swedish and European guidelines, i.e., below 3.0 mmol/L.
PMID- 10687345
TI - [Diagnosis and treatment of heart failure in primary health care. Low correlation
between Pro-ANF and heart failure].
AB - Three eastern Swedish primary care clinics serving a predominantly rural
clientele monitored for 13 months all patients under 80 years of age with a
diagnosis based on clinical signs alone of heart failure (n = 56) or suspected
incipient heart failure (n = 62). Echocardiography was performed on all patients.
For 64% of the former group, the putative diagnosis matched echocardiography
findings. Results showed a purely diastolic disorder in one-fifth of all 118
patients, and a hemodynamically significant, hitherto unknown heart defect in
about as many. Pro-ANF assays correlated poorly with manifest heart failure.
Pharmacological treatments were registered, and at 6-month follow-up, 82% of
patients with systolic failure were receiving ACE-inhibition.
PMID- 10687346
TI - [Radioimmunotherapy is rapidly developing to clinically efficient therapy].
AB - The use of monoclonal antibodies (mabs) in cancer therapy has gained renewed
interest, due to recent reports of remarkable clinical response, particularly in
patients with low-grade non-Hodgkin lymphoma. Better defined and more appropriate
target antigens and "humanized" mabs, reducing the risk of inducing neutralising
human anti-mouse antibodies, have contributed to the improvement in results.
Conjugation of mabs with various radionuclides is now being explored as a means
of further enhancing clinical efficacy, the idea being to allow systemic delivery
of targeted radiation to areas of disease while sparing normal tissue.
Radioimmunotherapy may be administered as a single large dose of radiolabelled
mabs, usually requiring haematological stem cell support, or as multiple, smaller
fractions. The criteria for the selection of mabs and radionuclides are discussed
in the article, as are recent clinical data and the problems and prospects of
future developments in radioimmunotherapy.
PMID- 10687347
TI - [About knowledge and knowledge development within general practice. General
practitioners meet questions of life in their medical version].
PMID- 10687348
TI - [The special physician-patient relation in connection to chronic fatigue
syndrome. Anthropologists and physicians search for a new contact-model].
PMID- 10687349
TI - [Chronic fatigue syndrome--old wine in new bottles].
PMID- 10687350
TI - [To rank with safety. A new statistical method shows the way].
PMID- 10687351
TI - [Too simplified view on euthanasia. A comment to a book review].
PMID- 10687352
TI - [The first sperm captured in a picture: on its way to the ovum or out of the
ovum?].
PMID- 10687353
TI - [School health services in future. Unique children in a school for all].
PMID- 10687354
TI - [Will we ever say no? For example to the RSV prophylaxis?].
PMID- 10687355
TI - [We want to put resources for the generalists!].
PMID- 10687356
TI - [The TV report on MedAnalys. An alarming example of misleading journalism].
PMID- 10687357
TI - Medical personnel and death.
AB - Increased life expectancy and increases in the number of terminally ill patients,
the rapid change in healthcare technology and diagnostic protocols and treatment
means that we must re-examine medico-social problems and the attitude of
healthcare professionals when confronted by death and terminal illnesses. The aim
of this paper is to analyse the attitudes of medical personnel towards death and
terminal patients. A total of 375 (168 doctors and 207 nurses) were asked about
their attitudes toward death and the terminally ill. The sample comprised 165
males and 210 females aged between 20 and 64 years (mean age 34.96, SD 7.83
years). The results showed that 51.0% of the subjects interviewed were afraid of
death. Although 59.4% thought that they were personally prepared to treat and
help the terminally ill and 75.3% professionally prepared for such a task 42.7%
of those interviewed would prefer not to work with the terminally ill.
PMID- 10687358
TI - Bloodless surgery developments accommodate patients' choice of treatment.
AB - The medical and ethical challenge of treating Jehovah's Witnesses without blood
transfusions is being met by dedicated professionals around the world. Jehovah's
Witnesses have assisted by setting up a research department (Hospital Information
Services), with relevant information available at 100 branches world wide. They
have appointed over 1,300 Hospital Liaison Committees in major medical centres
throughout the world which disseminate relevant medical and legal literature to
obviate misunderstandings. The members of these committees receive regular
training and are internationally networked to assist medical and legal
professionals and to avoid unnecessary confrontations. They already list over
90,000 doctors world wide who provide bloodless medical care. Around the world
more than 190 hospitals offer bloodless medicine and surgery programmes.
PMID- 10687359
TI - Informed consent for psychiatric research: the case of medication-free research.
AB - Informed consent for research in psychiatry raises a number of ethical and legal
issues. To illustrate some of the ethical problems involved, in particular issues
of patient competence and proxy consent, as well as the motives of patients to
become research participants, as an example the case of so-called medication-free
research in schizophrenia is discussed. It is argued that an assessment of the
competence of potential research subjects to consent to participation, based on
explicit criteria, is necessary. In case of substituted consent it is shown that
proxy decision makers may fail to protect the interests of incompetent patients
in research. Finally, researchers ought to be aware that research subjects may be
motivated to participate in research because they may mistakenly believe that the
research project is designed to benefit them directly.
PMID- 10687360
TI - Pediatric research and the parens patriae jurisdiction in Canada and England.
AB - This paper considers the issue of enrolling non-autonomous minors as participants
in pediatric research in light of two high court decisions concerning the
sterilization of non-autonomous individuals in Canada and England. In particular,
this paper looks at the 1986 case of Re Eve in which the Supreme Court of Canada
found that sterilization of such persons under the parens patriae jurisdiction
can be justified only if direct, therapeutic benefit to the person has been
established. It is compared to the 1987 decision in Re B (a minor), in which the
English Law Lords repudiated the Canadian decision and upheld the broader,
traditional interpretation of the parens patriae jurisdiction which allowed best
interests as justification for the non-therapeutic sterilization of non
autonomous persons. With reference to differences in the interpretations of the
parens patriae jurisdiction by these two courts, it is suggested that until such
time that the Canadian courts consider a case directly on point, pediatric
researchers in that country must presume greater restrictions when enrolling non
autonomous subjects in research protocols than in countries such as England.
PMID- 10687361
TI - Alternative medicine in Israel: a case of non-regulation.
AB - The state of Israel is well known for its intervention in many aspects of its
citizens' lives. Yet alternative medicine, a widely demanded service pertaining
to a critical aspect of human life, remains outside the confines of state
intervention. During Israel's fifty years of existence not a single law has been
enacted to regulate alternative medicine. It is neither recognized nor banned.
The major argument of this paper is that state unconcern, depicted as the
antithesis of regulation, presents in a nutshell the ideological, economic, and
social dilemmas confronting state and society. Official attitudes toward
alternative medicine thus mirror the structure of values and the structure of
power. In each of these domains positive and negative forces are identified,
those seeking change (either toward banning or toward recognition) and forces
aiming at preserving the status quo.
PMID- 10687362
TI - The legality of slimming advertisements in Singapore.
AB - Governments in newly affluent countries like Singapore perceive a growing obesity
problem, which in turn attracts the attention of numerous suppliers of slimming
aids of dubious value. Advertisements relating to these appear in many cases to
breach the Sale of Food Act and the Medicines Act. Under these provisions, oral
and transdermal slimming aids which are not prescription drugs or on the General
Sales List must have a permit if they are to be advertised, which is granted if
the authorities are satisfied as to the existence of evidence for efficacy. If
perceived to be harmful, however, a product can be banned and if the associated
advertisement is misleading it will attract a financial penalty. Slimming aids
formally excluded (like herbal preparations) can be brought under the Act by
executive order and banned from sale. That this formidable array of controls is
rarely applied is due to the voluntary regulatory machinery of an advertising
standards authority, a non-governmental body with a parallel in many other
countries. However it has limited resources. It is suggested that either the
executive or the advertising authority or both could adopt more rigorous criteria
for the application of the law in the interests of the public.
PMID- 10687363
TI - The beginning of life--ethical perspectives.
AB - In 1973 Judge Blackmun, in the celebrated case of Roe v Wade, stated that "we
need not resolve the difficult question of when life begins". A quarter of a
century later, there is indeed a need to attempt to resolve this question. This
article sets out briefly ethical issues arising from medically-assisted
procreation and analyses the concepts of life, personhood and the beginning of
personhood. It is submitted that the fundamental criterion in resolving the issue
is to rethink the value and dignity of human life in a technologically advanced
world. Since the ultimate wisdom on the purpose of life emanates from God, the
article analyses diverse theological perspectives, in particular that of
Christianity and Islam. In valuing human life, the article asserts that human
beings must use technology responsibly and to humankind's benefit, rather than
submit to exploitation by it.
PMID- 10687364
TI - The Israeli Law of Freedom of Information 1998--implications with respect to the
healthcare system.
AB - The right of the Israeli public to get information from state authorities has
been based until recently only on Israeli Supreme Court rulings. In 1998, a Law
of Freedom of Information was enacted. The new Law tries to follow the rulings of
the Israeli Supreme Court regarding freedom of information, in establishing
substantive statutory arrangements.
PMID- 10687365
TI - Care of the mentally ill offender. A model service.
AB - Caring for mentally ill offenders has been a contentious issue in almost all
parts of the world. In some countries such as New South Wales in Australia, a
humane approach has gradually evolved over the years. This paper describes a
successful service delivery model for forensic patients in a metropolitan
psychiatric hospital in Sydney. Issues relating to selection criteria, problems
associated with caring for the mentally ill offender in a general psychiatric
hospital environment and the integration of the forensic patients with civilian
psychiatric patients are discussed.
PMID- 10687366
TI - Late abortion and the European convention for human rights.
AB - National abortion laws usually do not allow abortion when a foetus is
independently viable, i.e. from a gestational age of about 24 weeks. Fetal
anomalies, which may be a reason to seek abortion, are sometimes detected only in
an advanced stage of pregnancy. National legislatures who want to allow 'late'
abortion need to account for the protection the fetus may derive from the
European Convention for the protection of human rights. As yet it remains unclear
to what extent the fetus can in fact derive protection from the Convention,
although several national abortion laws have been tested against it by the
European Commission. The significance of the reports of the Commission on the
question whether national legislation allowing abortion of a viable fetus is in
conflict with the Convention, is explored. It is concluded that there is no
European legal standard in terms of duration of pregnancy to which national
legislatures are committed.
PMID- 10687367
TI - The role of the artificial uterus in embryo adoption and neonatal intensive care.
AB - Embryo adoption is a way of having children for couples who wish to share a
pregnancy experience but have neither eggs nor sperm to realise their dream. This
type of situation could occur where the wife has had a hysterectomy, while her
husband has an extremely low sperm count. The donors of embryos are usually
couples who have completed their families. The artificial womb will duplicate the
technology of a natural womb so as to enable the child to gestate and develop
physically to maturity. This ability will enable the artificial womb to be used
to rescue severely premature babies who would otherwise have died and allow them
to develop normally to term. Legislation will be required to regulate situations
where an entire pregnancy is sustained in an artificial uterus. Clarity as to
parenthood in particular will need to be regulated.
PMID- 10687368
TI - The appraisal of narcotic drugs in Hungary.
AB - Hungary has a serious problem, historically significant and currently of
increasing size, partly due to changes in trafficking routes. This paper outlines
the development of measures to counter the situation, emphasising the provision
of forensic laboratory services with the aid of the United Nations Drug Control
program. An attempt is made to quantify more precisely permitted amounts of a
drug for personal use.
PMID- 10687369
TI - Humanizing nurse-patient communication: a challenge and a commitment.
AB - Nurse-patient communication has been a pre-established, unvarying, technical
professional and impersonal form of manifestation, reflecting mainly the
achievement of nurse's instrumental role. This situation is opposed to our
nursing concept as well as to the professional values that we incorporated during
our professional life, all of which emphasize the importance of the person and
the patient and the meaning of the visualisation of care to a total human being.
The present study aims at discussing this question, propitiating an opportunity
of reflection about the necessity of humanizing this relationship in the
Brazilian scenery. Thus, we focused on the importance of nurse-patient
relationship not only as an essential component of nursing assistance but also as
a treatment in itself. In addition, we stimulate nurses to examine the way they
are taking care of human beings: as objects to be manipulated and treated or as
persons that need care and comprehension. The article is concluded with the
thesis that nursing is not a technical profession that manipulates knowledge and
technologies but a work of valuing human beings, their freedom and dignity.
PMID- 10687370
TI - Police custody detainees and forensic medicine: use of medical resources in the
cell block.
AB - Various Dutch reports show that medical usage among those detained in police
cells is many times higher than among the average population. Many visits by
forensic physicians (some 36%) are due to the fact that many police custody
detainees are addicted. Also, many visits are carried out as a result of the fact
that the police must frequently put into custody individuals who suffer
intoxications and/or injuries (some 13%) or psychiatric problems (6%-17%). In
addition, many visits are for the benefit of detainees who cannot cope with
conditions during their detention (21%-30%). Only a minority of the visits are to
help police custody detainees who are (chronically) ill. Because of all this, a
forensic physician's work mainly consists of writing repeat prescriptions,
prescribing methadone, referring detainees to other assistance services and
giving advice to guards or police officers on duty. This makes forensic medicine
a profession in a class of its own.
PMID- 10687371
TI - Patients who deceive.
PMID- 10687372
TI - Get it right the first time.
PMID- 10687373
TI - How to build an unbeatable estate plan.
PMID- 10687374
TI - Total temporomandibular joint replacement. Who? What? When? Where?
AB - The temporomandibular joint, like other joints such as the hip and knee, can be
affected by a number of conditions that may lead to joint failure, necessitating
total joint replacement. The TMJ Implants, Inc., or Christensen alloplastic
reconstruction prostheses, play an important role in the treatment of these
conditions. Patients with severely degenerated and/or nonfunctioning joints who
undergo reconstruction with the Christensen total joint replacement prosthesis
experience an increase in quality of life similar to that experienced by
orthopedic patients with total joint replacement of the knee or hip.
PMID- 10687375
TI - Acquired allergic reaction to topical anesthesia--a case report.
AB - The incidence of allergic reactions to injected local anesthesia in dentistry is
rare. This case was initially suspected of being such an allergic reaction.
Careful history taking and immunological techniques indicated a reaction to the
topical anesthesia.
PMID- 10687377
TI - An example of measurement and reporting of periodontal loss of attachment (LOA)
in epidemiological studies: smoking and periodontal tissue destruction.
AB - The measurement and reporting of periodontal disease in epidemiological studies
can be complex, with the common indices having well-recognised shortcomings. The
aim of this study was to illustrate the use of the periodontal loss of attachment
(LOA) approach in investigating the association between cigarette smoking and
loss of periodontal attachment in a convenience sample of adults, in order to
determine whether or not smoking was a risk indicator for periodontal disease.
All participants were given a detailed periodontal clinical examination in two
randomly assigned contralateral diagonal quadrants, with LOA measurements made at
six sites per tooth. Information was also collected on participants' socio
demographic characteristics, oral hygiene practices, smoking history, and
attitudes towards smoking. The 240 participants examined comprised 81 current
smokers (CS), 79 former smokers (FS) and 80 nonsmokers (NS). Substantial
differences and a gradient in disease existed for LOA among the three groups. CS
exhibited the greatest (and NS the least) prevalence, extent, and severity of
LOA. CS had more plaque and calculus than either of the other two groups, but the
groups did not differ with respect to bleeding on probing. Overall, smoking was
associated with the disease outcome, and this persisted after potential
confounders were controlled using multivariate analysis. Although the observed
differences may have been due to the self-selected nature of the sample, the
gradient evident across the three smoking exposure groups suggests that smoking
cessation can slow the progression of the disease. The LOA approach appears to be
a versatile and informative method for recording, analysing, and presenting data
on periodontitis in epidemiological studies.
PMID- 10687378
TI - Dental voluntary work--a year in Uganda.
PMID- 10687379
TI - Atypical migration of an impacted lower third molar.
AB - This report describes the atypical migration of an impacted lower third molar
tooth in a 42-year-old woman. Serial radiographs showed that, over a period of 13
years, the tooth migrated from its original disto-angular position posterior to
and beneath the roots of the adjacent second molar to a more horizontal position
beneath the roots of the first permanent molar. The tooth was surgically removed
under general anaesthesia, with biopsy and curettage of soft tissue found in the
bone posterior to the tooth along the path of migration. This pattern of tooth
movement is highly unusual in an adult patient.
PMID- 10687380
TI - Dental treatment of patients with neurodegenerative disease.
AB - Neurodegenerative disorders are among the most challenging and devastating
illnesses in medicine. A heterogeneous group of chronic and progressive diseases,
they include Alzheimer's, Parkinson's, and Huntington's diseases. Dentists faced
with patients affected by one of these disorders are confronted with the major
problems of cognition, mobility, and behaviour, as well as of dental maintenance.
While treatment of patients with progressive neurodegeneration remains daunting,
increased knowledge of the aetiology and pathogenesis of these diseases has
provided new opportunities and a new understanding of their treatment needs. In
this article, we briefly describe the effects of ageing on the brain, and
introduce two of the major neurodegenerative disorders, Alzheimer's and
Parkinson's diseases. The dental problems associated with these conditions
include a decrease in oral hygiene, difficulty in controlling and retaining
dentures, and purposeless chewing. Medications can result in xerostomia and
consequent root caries and recurrent decay. Where possible, individuals with
neurodegenerative disorders should always be treated by the same dentist.
PMID- 10687381
TI - Synergistic insecticidal mode of action between sesquiterpene lactones and a
phototoxin, alpha-terthienyl.
AB - The synergistic insecticidal action of characteristic defensive substances
produced by the plant family Asteraceae was investigated under controlled
laboratory conditions. Sesquiterpene lactones isolated from Asteraceae that may
form, through a Michael addition process, conjugates with glutathione were
administered in a meridic diet to a herbivorous insect, Manduca sexta. By
administering sesquiterpenes, variable in vivo reduced glutathione levels were
observed in the insect larvae. When the Asteraceae-derived photooxidant alpha
terthienyl was co-administered, lipid peroxidation and larval mortality were
significantly enhanced in the treated groups of insects with lowered in vivo
glutathione levels.
PMID- 10687382
TI - UVB/UVA radiation activates a 48 kDa myelin basic protein kinase and potentiates
wound signaling in tomato leaves.
AB - We investigated the effect of UV radiation on early signaling events in the
response of young tomato plants (Lycopersicon esculentum) to wounding.
Ultraviolet-C (< 280 nm) and UVB/UVA (280-390 nm) radiation both induced 48 kDa
myelin basic protein kinase activity in leaves. The activation was associated
with phosphorylation of tyrosine residues on the kinase, which is indicative of
protein kinases of the mitogen-activated protein kinase family. Ultraviolet-C
irradiation resulted in a strong proteinase inhibitor synthesis, as reported
previously (Conconi et al., Nature 383, 826-829, 1996). Under the conditions
used, UVB/UVA radiation did not induce proteinase inhibitor synthesis but
resulted in a strong potentiation of systemic proteinase inhibitor synthesis in
response to wounding. The UVB/UVA-irradiated plants that were subsequently
wounded accumulated 2.5-4-fold higher levels of proteinase inhibitor I when
compared to wounded non-irradiated plants. The potentiating effect was most
prominent in the systemic unwounded leaf of a wounded plant. Levels of 12-oxo
phytodienoic acid and jasmonic acid that have been well documented to increase in
response to wounding were not detected in response to UVB/UVA irradiation alone.
The effect of UVB/UVA radiation in potentiating plant defense signaling should be
further considered as a factor that may influence the ecological balance between
plants and their predators.
PMID- 10687383
TI - Porphyrins and related compounds as photoactivatable insecticides. 3. Laboratory
and field studies.
AB - The exposure of populations of Ceratitis capitata (fruit fly), Bactrocera oleae
(olive fly) and Stomoxis calcitrans (house fly) to a bait containing mumolar
concentrations of porphyrin-type photosensitizers resulted in a significant
accumulation of the porphyrin by the insects and a consequent development of
photosensitivity upon exposure to visible light. The photoinsecticidal activity
appeared to increase with increasing hydrophobicity of the porphyrin molecule:
thus, the amphiphilic dicationic meso-di(cis-4N-methyl-pyridyl)-cis-diphenyl
porphine (n-octanol/water partition coefficient = 20) was markedly more efficient
than its tricationic analogue or the dianionic hematoporphyrin (n-octanol/water
partition coefficient = 12). The observed large decrease in the
acetylcholinesterase activity of the photosensitized flies suggests that the
damage of the nervous system gives an important contribution to the phototoxic
action of porphyrins. Studies with C. capitata indicate that the
photoinsecticidal action of porphyrins can be utilized to control the population
of noxious insects also in open field conditions.
PMID- 10687384
TI - Vitamin B6 (pyridoxine) and its derivatives are efficient singlet oxygen
quenchers and potential fungal antioxidants.
AB - Vitamin B6 (pyridoxine, 1) and its derivatives: pyridoxal (2), pyridoxal 5
phosphate (3) and pyridoxamine (4) are important natural compounds involved in
numerous biological functions. Pyridoxine appears to play a role in the
resistance of the filamentous fungus Cercospora nicotianae to its own abundantly
produced strong photosensitizer of singlet molecular oxygen (1O2), cercosporin.
We measured the rate constants (kq) for the quenching of 1O2 phosphorescence by 1
4 in D2O. The respective total (physical and chemical quenching) kq values are:
5.5 x 10(7) M-1 s-1 for 1; 7.5 x 10(7) M-1 s-1 for 2, 6.2 x 10(7) M-1 s-1 for 3
and 7.5 x 10(7) M-1 s-1 for 4, all measured at pD 6.2. The quenching efficacy
increased up to five times in alkaline solutions and decreased approximately 10
times in ethanol. Significant contribution to total quenching by chemical
reaction(s) is suggested by the degradation of all the vitamin derivatives by
1O2, which was observed as declining absorption of the pyridoxine moiety upon
aerobic irradiation of RB used to photosensitize 1O2. This photodegradation was
completely stopped by azide, a known physical quencher of 1O2. The pyridoxine
moiety can also function as a redox quencher for excited cercosporin by forming
the cercosporin radical anion, as observed by electron paramagnetic resonance.
All B6 vitamers fluoresce upon UV excitation. Compounds 1 and 4 emit fluorescence
at 400 nm, compound 2 at 450 nm and compound 3 at 550 nm. The fluorescence
intensity of 3 increased approximately 10 times in organic solvents such as
ethanol and 1,2-propanediol compared to aqueous solutions, suggesting that
fluorescence may be used to image the distribution of 1-4 in Cercospora to
understand better the interactions of pyridoxine and 1O2 in the living fungus.
PMID- 10687385
TI - Dihydrocercosporin singlet oxygen production and subcellular localization: a
possible defense against cercosporin phototoxicity in Cercospora.
AB - Fungi in the genus Cercospora produce cercosporin, a potent singlet oxygen (1O2)
generating photosensitizer that plays a critical role in the ability of these
fungi to parasitize plants. Although plants, mice, bacteria and many fungi are
sensitive to cercosporin, Cercospora species are resistant to its toxicity. The
cellular resistance of these fungi to cercosporin has been correlated with fungal
cell surface reducing ability and the ability to maintain cercosporin in a
chemically reduced state. As a model for reduced cercosporin we employed a
reduced, acetylated derivative (hexaacetyl-dihydrocercosporin, HAC) that we
tested for 1O2 production in a range of solvents. We found that as a 1O2
photosensitizer, HAC was only moderately effective in organic solvents (phi SO =
0.14-0.18) and very poor in water (phi SO = 0.02-0.04). By contrast, the 1O2
quantum yield of cercosporin itself was unaffected by solvent (phi SO = 0.84
0.97). To investigate the localization of reduced cercosporin in fungal cells, we
developed a fluorescence assay using laser scanning confocal microscopy. This
assay showed a uniform green fluorescence, indicative of reduced cercosporin, in
the cytoplasm of hyphal cells treated with cercosporin. We hypothesize that the
main protection mechanism against cercosporin phototoxicity in the fungus
consists of transformation of cercosporin to a reduced state and localization of
this reduced form in the aqueous compartment of the cell, thus decreasing
intracellular 1O2 production to levels that can be tolerated by the fungus. In
addition, we have, for the first time, directly detected 1O2 phosphorescence from
fungal culture, either stained with the photosensitizer rose bengal or actively
synthesizing cercosporin, demonstrating 1O2 production in vivo and from
cercosporin in culture.
PMID- 10687386
TI - Photoyellowing inhibition of bleached high yield pulps using novel water-soluble
UV screens.
AB - To address the deficiencies of benzophenone UV screens for preventing brightness
reversion in high yield mechanical papers, we synthesized a new series of such
materials with enhanced water solubility and compatibility with the
lignocellulosic substrate. A series of 2,4-dihydroxybenzophenones (DHB) were
synthesized containing various Mannich bases at the C3 position of one of its
rings. They possess the UV-screening ability of o-hydroxylbenzophenones, and they
also contain tertiary nitrogen atoms that may function as radical scavengers.
Aqueous solutions of the hydrochloride salt of 3-(dimethylaminomethylene)-2,4
dihydroxylbenzophenone (1), when applied on bleached chemithermomechanical pulp
(CTMP) sheets, were significantly more efficient in preventing photoyellowing
than the original DHB applied on the sheets from ethanol-water solutions. This
confirmed our original hypothesis that increasing the compatibility of the UV
screen with the lignocellulosic matrix would increase its efficiency in
preventing photoyellowing. Compound 1, however, was found to be somewhat more
effective than its hydrochloride salt toward preventing photoyellowing. This was
attributed to the synergistic action of the free tertiary aminic center attached
on the molecule with its UV-screening ability. To comprehend further the various
parameters that influence the photoyellowing inhibition performance of these
compounds and DHB with bleached CTMP pulp fibers, a series of handsheets were
prepared at different pH. The interactions of the protonated compound 1 with pulp
fibers were then evaluated by studying their kinetics of absorption and
desorption to and from the fiber matrix. This part of our study found that the
adsorption of protonated Mannich derivatives of DHB onto pulp is most likely
governed by a cation-exchange mechanism involving the cationic amine group with
the sulfonic and carboxylic acid groups located on the surface of the fibers. The
pH the paper sheet was made from was also found to affect profoundly the
adsorption and retention characteristics of these compounds onto the
lignocellulosic matrix.
PMID- 10687387
TI - On the interaction of UV screens with the lignocellulosic matrix.
AB - In this report, we describe our attempt to understand the photochemical
interactions that occur between dihydroxybenzophenone (DHB)-based UV screens and
lignin when high-yield pulps are treated with such materials. Milled wood lignin
(MWL) and filter paper were used as models, and various irradiation protocols
were carried out in the presence and absence of UV screens. After irradiation,
the lignin and the UV screen were extracted and the products analyzed. These
experiments showed that upon irradiation, fragments of MWL-containing
chromophores were linked to cellulose via an acid-labile linkage. In the presence
of UV screens, these reactions were minimized. Molecular weight measurements of
the extracted lignin showed that the MWL is degraded upon solid-state
irradiation. The samples that contained UV screens showed a reduced tendency to
degrade. Using quantitative 31P NMR, it was possible to probe further the
detailed structural changes that occurred in MWL during irradiation. In general,
DHB-based UV screens and derivatives were found to interact actively with MWL
when irradiated.
PMID- 10687388
TI - End-to-end diffusion on the microsecond timescale measured with resonance energy
transfer from a long-lifetime rhenium metal-ligand complex.
AB - We measured the end-to-end diffusion coefficient of an alkyl chain-linked donor
acceptor pair using the time-resolved frequency-domain decay of the donor. The
donor was a rhenium metal-ligand complex with a mean decay time ranging from 2.1
to 7.9 microseconds in the absence of the Texas red acceptor. The decay time was
used to measure the donor-to-acceptor distance distribution and the mutual
diffusion coefficient. Using this long lifetime donor, it was easily possible to
determine a diffusion coefficient near 2 x 10(-8) cm2/s and diffusion
coefficients as low as 1.3 x 10(-9) cm2/s were measurable. Such long lifetime
donors should be valuable for measuring the flexing of peptides on the
microsecond timescale, domain motions of proteins and lateral diffusion in
membranes. The availability of microsecond decay time luminophores now allows
luminescence spectroscopy to be useful generally for studies of microsecond
dynamics of biological macromolecules.
PMID- 10687389
TI - Effects of cytosine methylation on pyrimidine dimer formation in DNA.
AB - The relative induction of cyclobutane pyrimidine dimers (CPD) and pyrimidine (6
4)pyrimidone photoproducts ([6-4]PD) was quantified in the duplex homopolymers
polydeoxyadenosine:polydeoxythymidine, polydeoxyguanosine:polydeoxycytidine and
polydeoxyguanosine:polydeoxy-5-methylcytidine irradiated with UVC or UVB
radiation. Cytosine methylation significantly increased the yield of cytosine (6
4)PD after irradiation with UVC light and of cytosine CPD and (6-4)PD after
irradiation with UVB light. The data suggest that CPD and (6-4)PD are
preferentially induced at 5-methylcytosine bases in DNA of cells exposed to
sunlight and comprise a major component of the mutation spectrum leading to the
initiation of sunlight-induced skin cancer.
PMID- 10687390
TI - Multidimensional reaction coordinate for the excited-state H-atom transfer in
perylene quinones: importance of the 7-membered ring in hypocrellins A and B.
AB - The excited-state intramolecular H-atom transfer reactions of hypocrellins B and
A are compared by using time-resolved absorption and fluorescence upconversion
techniques. The hypocrellin B photophysics are well described by a simple model
involving one ground-state species and excited-state forward and reverse H-atom
transfer with a nonfluorescent excited state. We suggest that excited-state
conformational changes are coupled to the H-atom transfer in hypocrellin B just
as gauche/anti changes are coupled to the H-atom transfer in hypocrellin A.
PMID- 10687391
TI - A photophysical and photochemical study of 6-methoxy-2-naphthylacetic acid, the
major metabolite of the phototoxic nonsteroidal antiinflammatory drug nabumetone.
AB - Nabumetone is a phototoxic nonsteroidal antiinflammatory drug used for the
treatment of osteoarthritis. However, nabumetone is considered a prodrug with its
metabolite 6-methoxy-2-naphthylacetic acid the active form. Photophysical and
photochemical studies on this metabolite have been undertaken. It undergoes
photodecarboxylation in aerated aqueous and organic solvents. In addition to the
accepted photodegradation pathway for related molecules, a new mechanism that
implies generation of the naphthalene radical cation from the excited singlet and
addition of O2 prior to the decarboxylation process has been demonstrated.
Evidence for the involvement of the excited singlet state in this mechanism have
been obtained by steady-state and time-resolved fluorescence experiments. The
fluorescence quenching by O2 and the shorter singlet lifetime in aerated solvents
support this assignment. Laser flash photolysis also supports this mechanism by
showing the noninvolvement of the triplet in the formation of the naphthalene
radical cation. Finally, the well-known electron acceptor CCl4 acts as an
efficient singlet quencher, enhancing the route leading to the radical cation,
preventing intersystem crossing to the triplet and thus resulting in a dramatic
increase in the yield of 6-methoxy-2-naphthaldehyde, the major oxidative
decarboxylation product; this constitutes unambiguous proof in favor of the new
mechanistic proposals.
PMID- 10687392
TI - Time-resolved fluorescence spectra of arterial fluorescent compounds:
reconstruction with the Laguerre expansion technique.
AB - The time-resolved fluorescence spectra of the main arterial fluorescent compounds
were retrieved using a new algorithm based on the Laguerre expansion of kernels
technique. Samples of elastin, collagen and cholesterol were excited with a
pulsed nitrogen laser and the emission was measured at 29 discrete wavelengths
between 370 and 510 nm. The expansion of the fluorescence impulse response
function on the Laguerre basis of functions was optimized to reproduce the
observed fluorescence emission. Collagen lifetime (5.3 ns at 390 nm) was
substantially larger than that of elastin (2.3 ns) and cholesterol (1.3 ns). Two
decay components were identified in the emission decay of the compounds. For
collagen, the decay components were markedly wavelength dependent and hydration
dependent such that the emission decay became shorter at higher emission
wavelengths and with hydration. The decay characteristics of elastin and
cholesterol were relatively unchanged with wavelength and with hydration. The
observed variations in the time-resolved spectra of elastin, collagen and
cholesterol were consistent with the existence of several fluorophores with
different emission characteristics. Because the compounds are present in
different proportions in healthy and atherosclerotic arterial walls,
characteristic differences in their time-resolved emission spectra could be
exploited to assess optically the severity of atherosclerotic lesions.
PMID- 10687393
TI - Strategies for evaluation of enveloped virus inactivation in red cell
concentrates using hypericin.
AB - Photodynamically induced virus inactivation appears promising in preventing
transmission of enveloped virus infections in transfusible blood products. The
potential for utilizing hypericin as a photosensitizer to inactivate key
enveloped viruses in packed red cell concentrates (PRC) was evaluated. In
addition to inactivating effectively > or = 10(6) TCID50 of human
immunodeficiency virus (HIV), inactivation of bovine viral diarrhea virus (BVDV)
in PRC was used as a model for hepatitis C virus to overcome the deficiency in
reliable experimental systems for hepatitis C virus (HCV) inactivation. BVDV was
two orders of magnitude more sensitive to inactivation by hypericin than HIV. As
part of the virucidal efficacy analyses, the effects of photosensitization on
hemopoietic cell lines carrying quiescent integrated HIV provirus were studied as
models for evaluating virus inactivation in latently infected cells. Phorbol
ester-induced virus production by these cells was effectively prevented by
photosensitization with hypericin. A refinement of the illumination conditions,
incorporating a monochromatic sodium light source with an emission spectrum
coinciding with the absorption peak of hypericin, was highly virucidal, however,
caused unacceptable levels of hemolysis. Red blood cells could be protected from
phototoxic cellular damage by complexing hypericin with human serum albumin
(albumin-hypericin), but the decrease in hemolysis was at the expense of
virucidal efficacy. Thus, excitation of hypericin with a fluorescent source
appears to be useful potentially for virus inactivation in PRC.
PMID- 10687394
TI - Determinants of the apoptotic response to lysosomal photodamage.
AB - Studies with mouse leukemia L1210 cells revealed that selective lysosomal
photodamage caused by any of three photosensitizing agents was followed by a
gradual loss of the mitochondrial membrane potential (delta psi m), release of
cytochrome c into the cytosol, increased DEVDase activity (a measure of levels of
caspase-3) and a limited apoptotic response. Similar effects were observed in the
murine hepatoma 1c1c7 cell line. Immunofluorescence techniques employing 1c1c7
cells demonstrated the immediate release of the lysosomal enzyme cathepsin B
following lysosomal photodamage. These studies suggest that the cytotoxic effects
of lysosomal photodamage are initiated by released lysosomal proteases that
either directly and/or indirectly activate caspases as a consequence of the
induction of mitochondrial damage.
PMID- 10687395
TI - The role of the p53 tumor suppressor in the response of human cells to photofrin
mediated photodynamic therapy.
AB - Although there is evidence that the p53 tumor suppressor plays a role in the
response of some human cells to chemotherapy and radiation therapy, its role in
the response of human cells to photodynamic therapy (PDT) is less clear. In order
to examine the role of p53 in cellular sensitivity to PDT, we have examined the
clonogenic survival of normal human fibroblasts that express wild-type p53 and
immortalized Li-Fraumeni syndrome (LFS) cells that express only mutant p53,
following Photofrin-mediated PDT. The LFS cells were found to be more resistant
to PDT compared to normal human fibroblasts. The D37 (LFS cells)/D37 (normal
human fibroblasts) was 2.8 +/- 0.3 for seven independent experiments. Although
the uptake of Photofrin per cell was 1.6 +/- 0.1-fold greater in normal human
fibroblast cells compared to that in LFS cells over the range of Photofrin
concentrations employed, PDT treatment at equivalent cellular Photofrin levels
also demonstrated an increased resistance for LFS cells compared to normal human
fibroblasts. Furthermore, adenovirus-mediated transfer and expression of wild
type p53 in LFS cells resulted in an increased sensitivity to PDT but no change
in the uptake of Photofrin per cell. These results suggest a role for p53 in the
response of human cells to PDT. Although normal human fibroblasts displayed
increased levels of p53 following PDT, we did not detect apoptosis or any marked
alteration in the cell cycle of GM38 cells, despite a marked loss of cell
viability. In contrast, LFS cells exhibited a prolonged accumulation of cells in
G2 phase and underwent apoptosis following PDT at equivalent Photofrin levels.
The number of apoptotic LFS cells increased with time after PDT and correlated
with the loss of cell viability. A p53-independent induction of apoptosis appears
to be an important mechanism contributing to loss of clonogenic survival after
PDT in LFS cells, whereas the induction of apoptosis does not appear to be an
important mechanism leading to loss of cell survival in the more sensitive normal
human fibroblasts following PDT at equivalent cellular Photofrin levels.
PMID- 10687396
TI - Biodistribution and bioactivity of tetra-pegylated meta
tetra(hydroxyphenyl)chlorin compared to native meta-tetra(hydroxyphenyl)chlorin
in a rat liver tumor model.
AB - It has been proposed that the construction of a photosensitizer-polymer conjugate
would lead to an increased selective retention of the drug in tumor tissue
resulting in an enhancement of selective tumor destruction by light in
photodynamic therapy. In this study the kinetics of a tetra-pegylated derivative
of meta-tetra(hydroxyphenyl)chlorin (mTHPC-PEG) were compared with those of
native meta-tetra(hydroxyphenyl)chlorin (mTHPC) in a rat liver tumor model. In
addition, the time course of bioactivity of both drugs was studied in normal
liver tissue. Pegylation of mTHPC resulted in a two-fold increase in the plasma
half-life time, a five-fold decrease in liver uptake and an increase in the tumor
selectivity at early time intervals after drug administration. However, although
mTHPC concentrations in liver decrease rapidly with time, mTHPC-PEG liver
concentrations increased as a function of time. This led to a loss of tumor
selectivity at all but the earliest time points, whereas with mTHPC tumor
selectivity increased with time. For both drugs the time course of bioactivity in
the liver parallels drug concentration levels with extensive necrosis after
irradiation of mTHPC-PEG-sensitized liver tissue up to drug-light intervals of
120 h. It is concluded that on balance mTHPC-PEG does not appear to show any
benefits over native mTHPC for the treatment of liver tumors, as normal liver
tissue accumulates the compound. However, pegylation is a potentially promising
strategy with an increase in tumor selectivity and reduced liver uptake if
accumulation in the liver can be prevented.
PMID- 10687397
TI - Proteoglycan synthesis in porcine nasal cartilage grafts following Nd:YAG (lambda
= 1.32 microns) laser-mediated reshaping.
AB - Mechanically deformed morphologic cartilage grafts undergo temperature-dependent
stress relaxation during sustained laser irradiation resulting in stable shape
changes. In this study, porcine nasal septal cartilage specimens were evaluated
for viability by measuring the incorporation of Na2(35)SO4 into proteoglycan
(PTG) macromolecules in whole tissue culture following laser-mediated reshaping.
Synthesis rates of PTG were determined by scintillation counting lyophilized
specimens and normalizing these values by total protein content. Positive
controls were established by inducing chondrocyte apoptosis using prolonged
exposure to nitric oxide (NO). In chondrocytes, apoptosis induced using NO
resulted in significantly lower PTG synthesis rates compared to untreated native
specimens. Cartilage specimens were irradiated with light emitted from a Nd:YAG
laser (25 W/cm2, lambda = 1.32 microns) while recording simultaneously
radiometric surface temperature, internal stress and back-scattered light
intensity from a probe laser. Each specimen received one, two or three sequential
laser exposures. The duration of each exposure was determined from real-time
measurements of characteristic changes in back-scattered light intensity that
correlate with accelerated stress relaxation. A 5 min time interval between each
laser exposures allowed the cartilage specimen to return to thermal equilibrium.
Average PTG synthesis rates decreased with successive laser exposures, though
these were always higher than baseline rates established for NO-treated tissues,
suggesting that laser-mediated cartilage reshaping acutely does not eliminate the
entire population of viable chondrocytes. The reduction in PTG synthesis is
correlated with the time-temperature-dependent heating profile created during
laser irradiation, supporting our hypothesis that careful monitoring of laser
dosimetry is required to ensure chondrocyte viability.
PMID- 10687398
TI - Transmission spectra of light to the mammalian retina.
AB - A simple method has been developed to determine the optical properties of the
anterior segment of the intact eye. This consists of a probe that is inserted
into the posterior sclera and detects light passing through the anterior segment.
The probe is connected to a charge-coupled device spectrophotometer via a fiber
optic bundle. It was determined that the young rat anterior segment transmits
light down to 300 nm, whereas calf and rabbit eyes transmit no UVB and only part
of the UVA to the posterior segment. The absorbing species in these animals is
most likely NAD(P)H, which has an absorption maximum at approximately 345 nm and
is associated with zeta-crystallin. A young primate anterior segment transmits
almost no UV with a steep increase in transmission at CA 400 nm. Because some
experiments employed a light tube that is used to illuminate the retina during
vitrectomies, this method can be used to determine the transmission spectra of
the anterior segment of humans in vivo.
PMID- 10687399
TI - Properties of the bimodal fluorescent protein produced by Photobacterium
phosphoreum.
AB - A fluorescent protein isolated from the deep-sea luminous bacterium
Photobacterium phosphoreum strain bmFP has been purified, cloned and sequenced.
The protein is 96.5% identical in amino acid sequence to FP390, the weakly
fluorescent flavoprotein encoded by the luxF gene characteristic of
Photobacterium species. Similar to FP390, bmFP is a dimer of two homologous
subunits binding four FMN-myristate chromophores but has the distinctive feature
of emitting a bimodal fluorescence with maxima at about 488 and 517 nm, hence the
name bmFP. For both bands of this fluorescence, the excitation spectrum exhibits
a peak at 336 nm, not corresponding to its flavin-like absorption spectrum.
Heating of bmFP in urea resulted in a decrease in the intensity of the 488 nm
band along with the appearance of a new fluorescence peaking at 423 nm, partially
reversible upon the removal of the urea. Upon complete denaturation, either by
heat or guanidium chloride at 65 degrees C, fluorescence characteristic of both
free flavin and this 423 nm species appears. It is speculated that chromophores
in different states of protonation, associated with a single protein, are
responsible for the unusual spectral properties of bmFP.
PMID- 10687400
TI - Activities of the bimodal fluorescent protein produced by Photobacterium
phosphoreum strain bmFP in the luciferase reaction in vitro.
AB - The activity of the bimodal fluorescent protein (bmFP) (lambda max, 488 and 517
nm) in the in vitro luciferase reaction has been studied. The bmFP that is
produced by Photobacterium phosphoreum strain bmFP is a dimer of two homologous
subunits binding four riboflavin 5'-phosphate (FMN)-myristate chromophores. The
addition of bmFP to the luciferase reaction in the presence of the lumazine
protein prevented the lumazine protein-induced blue shift in the emission band.
The bmFP reduced electrochemically serves as a substrate in the luciferase
reaction in the absence of added FMN, resulting in light emission with a single
maximum at about 487 nm. The bmFP was also active in lieu of FMN in the NADH/FMN
oxidoreductase (flavin reductase)-luciferase coupled bioluminescence reaction in
the absence of added FMN. In the coupled reaction, bioluminescence with the
isolated bmFP chromophore was weaker than that with the holo-bmFP. After bmFP was
used in luciferase reactions initiated either chemically or electrochemically, it
was still capable of emitting bimodal fluorescence.
PMID- 10687401
TI - Foundations of spatial vision: from retinal images to perceived shapes.
AB - Vision is based on spatial correspondences between physically different
structures--in environment, retina, brain, and perception. An examination of the
correspondence between environmental surfaces and their retinal images showed
that this consists of 2-dimensional 2nd-order differential structure (effectively
4th-order) associated with local surface shape, suggesting that this might be a
primitive form of spatial information. Next, experiments on hyperacuities for
detecting relative motion and binocular disparity among separated image features
showed that spatial positions are visually specified by the surrounding optical
pattern rather than by retinal coordinates, minimally affected by random image
perturbations produced by 3-D object motions. Retinal image space, therefore,
involves 4th-order differential structure. This primitive spatial structure
constitutes information about local surface shape.
PMID- 10687402
TI - Society of self: the emergence of collective properties in self-structure.
AB - Using cellular automata, the authors show how mutual influences among elements of
self-relevant information give rise to dynamism, differentiation, and global
evaluation in self-concept. The model assumes a press for integration that
promotes internally generated dynamics and enables the self-structure to operate
as a self-organizing dynamical system. When this press is set at high values, the
self can resist inconsistent information and reestablish equilibrium after being
perturbed by such information. A weak press for integration, on the other hand,
impairs self-organization tendencies, making the system vulnerable to external
information. Paradoxically, external information of a random nature may enhance
the emergence of a stable self-structure in an initially disordered system. The
simulation results suggest that important global properties of the self reflect
the operation of integration processes that are generic in complex systems.
PMID- 10687403
TI - A model of response time effects in symbolic comparison.
AB - A cognitive process model is developed that predicts the 3 major symbolic
comparison response time effects (distance, end, and semantic congruity) found in
the results of the linear syllogistic reasoning task. The model includes a simple
connectionist learning component and dual evidence accumulation decision-making
components. It assumes that responses can be based either on information
concerning the positional difference between the presented stimulus items or on
information concerning the endpoint status of each of these items. The model
provides an excellent quantitative account of the mean correct response times
obtained from 16 participants who performed paired comparisons of 6 ordered
symbolic stimuli (3-letter names).
PMID- 10687404
TI - A model of dual attitudes.
AB - When an attitude changes from A1 to A2, what happens to A1? Most theories assume,
at least implicitly, that the new attitude replaces the former one. The authors
argue that a new attitude can override, but not replace, the old one, resulting
in dual attitudes. Dual attitudes are defined as different evaluations of the
same attitude object: an automatic, implicit attitude and an explicit attitude.
The attitude that people endorse depends on whether they have the cognitive
capacity to retrieve the explicit attitude and whether this overrides their
implicit attitude. A number of literatures consistent with these hypotheses are
reviewed, and the implications of the dual-attitude model for attitude theory and
measurement are discussed. For example, by including only explicit measures,
previous studies may have exaggerated the ease with which people change their
attitudes. Even if an explicit attitude changes, an implicit attitude can remain
the same.
PMID- 10687405
TI - Oscillator-based memory for serial order.
AB - A computational model of human memory for serial order is described (OSCillator
based Associative Recall [OSCAR]). In the model, successive list items become
associated to successive states of a dynamic learning-context signal. Retrieval
involves reinstatement of the learning context, successive states of which cue
successive recalls. The model provides an integrated account of both item memory
and order memory and allows the hierarchical representation of temporal order
information. The model accounts for a wide range of serial order memory data,
including differential item and order memory, transposition gradients, item
similarity effects, the effects of item lag and separation in judgments of
relative and absolute recency, probed serial recall data, distinctiveness
effects, grouping effects at various temporal resolutions, longer term memory for
serial order, list length effects, and the effects of vocabulary size on serial
recall.
PMID- 10687406
TI - Inferring children's categorizations from sequential touching behaviors: an
analytical model.
AB - A child is assumed to belong to 1 of 2 classes: categorizer or noncategorizer. To
determine which, 4 toy animals and 4 toy vehicles were randomly arrayed for
touching for 2 min. The task was to infer whether the child was a categorizer or
a noncategorizer for vehicles and similarly for animals. A model is proposed that
assumes a child's sequence of touches follows one probability distribution if the
child is a categorizer and another distribution if the child is a noncategorizer.
The proportion of children in each category and the probability of a child being
a categorizer for, say, vehicles are among the quantities that can be estimated.
Data from 18-month-old children are illustrative. The model appears efficient and
robust.
PMID- 10687407
TI - Is causal induction based on causal power? Critique of Cheng (1997).
AB - The authors empirically evaluate P. W. Cheng's (1997) power PC theory of causal
induction. They reanalyze some published data taken to support the theory and
show instead that the data are at variance with it. Then, they report 6
experiments in which participants evaluated the causal relationship between a
fictitious chemical and DNA mutations. The power PC theory assumes that
participants' estimates are based on the causal power p of a potential cause,
where p is the contingency between the cause and the effect normalized by the
base rate of the effect. Three of the experiments used a procedure in which
causal information was presented trial by trial. For these experiments, the power
PC theory was contrasted with the predictions of the probabilistic contrast model
and the Rescorla-Wagner theory. For the remaining 3 experiments, a summary
presentation format was employed to which only the probabilistic contrast model
and the power PC theory are applicable. The power PC theory was unequivocally
contradicted by the results obtained in these experiments, whereas the other 2
theories proved to be satisfactory.
PMID- 10687408
TI - A note on Corballis (1997) and the genetics and evolution of handedness:
developing a unified distributional model from the sex-chromosomes gene
hypothesis.
AB - A unified, quantitative model for sex, twin, parent, and grandparent influences
on handedness is presented. Recent research modeling the evolutionary development
of genetic mechanisms for the transmission of handedness on the basis of genotype
fitness has appeared to lead to the conclusion that a handedness gene cannot be
located on the sex chromosomes. It is shown in this article, however, that this
conclusion is not of general validity. The sex-chromosomes hypothesis is
developed further, and it is demonstrated that a wide-ranging, detailed, and
parsimonious account of the distribution of handedness is obtained when left
handedness is assumed to be associated recessively, and with low penetrance, with
genetic variation located on the X chromosome.
PMID- 10687409
TI - [RS3PE syndrome: are they hounds or greyhounds?].
PMID- 10687410
TI - [RS3PE syndrome or benign edematous polysynovitis in the elderly. Study of 8
cases].
AB - BACKGROUND: The RS3PE syndrome is a recently described uncommon disorder in the
elderly patient; in the initial reports, it was characterized by an excellent
prognosis with total remission. In contrast with rheumatoid arthritis and
polymyalgia rheumatic, it has been related to HLA B7. Further works have
questioned its benign nature and even that it is a new entity. Our objective was
to study the clinico-biological characteristics, therapy, and clinical course in
patients with RS3PE attended at our clinic. METHODS: Retrospective descriptional
study of patients with RS3PE attended in our clinic from January 1992 to December
1998 following the inclusion criteria proposed by Olive et al. For all patients,
the following determinations and studies were performed: complete blood count,
ESR, serum biochemistry, two measurements of rheumatoid factor (RF), and X-ray.
Class I HLA typing was determined in five cases. RESULTS: Eight patients were
found (6 men and 2 women), with a mean age of 68.7 years. The arthritis was more
common at MCP, wrists, shoulder, and PIF in hands. Four patients had
tenosynovitis of the hand flexors. ESR (mean: 69.3) and RCP (mean: 49.7) were
increased in most cases. Seven patients had leukocytosis. HLA B7 was positive for
4 out of five patients. All patients were treated with low-dose corticosteroids,
with a mean length of 9.5 months. Three patients had relapses. During follow-up
after therapy had been completed, none of the patients had other diseases.
CONCLUSIONS: RS3PE syndrome involves elderly patients and its clinical course is
characterized by sudden onset seronegative symmetrical polysynovitis, with
pitting edema over the hand dorsum and less commonly over the pretibial region.
In most cases, a marked acute-phase reaction and leukocytosis were observed.
Therapy with low-dose corticosteroids is effective; sometimes however, it is
necessary to add antimalarial agents. The three patients who relapsed had
underlying diseases: chronic lymphocytic leukemia, Sjogren's syndrome, and liver
cirrhosis, respectively. The diagnosis of RS3PE should be obtained a posteriori,
after a prolonged follow-up of the patient. Atypical cases, with evolution
towards other rheumatic or hematological disorders or as paraneoplastic
manifestation, have been reported.
PMID- 10687411
TI - [Serial assessment of the nutritional status of patients infected by the human
immunodeficiency virus. Role of tumor necrosis factor/its receptors].
AB - In order to analyze the nutritional status of HIV infected patients and the
involvement of the tumour necrosis factor-alpha (TNF-alpha) and its soluble
receptors (sTNFRI and sTNFRII) in such an status, forty HIV infected patients,
with no associated systemic opportunist infections, were prospectively followed
for eight months. From each patient the following were obtained: clinical
history, dietetic survey, anthropometric measurements, CD4+ T lymphocyte/mm3
count, HIV load, and serum concentration of TNF and sTNFRI and sTNFRII. Patients
showed a nutritional disorder which involved mainly the fat compartment (mean
tricipital skin fold 9.8 +/- 4.2 mm, that is, 65.7 +/- 27.4% of the ideal fold),
associated with a hypocaloric intake (mean daily intake 1,659.5 +/- 543.0 kcal),
with normal proportions of the different organic principles. Serum concentrations
of TNF (87.9 +/- 79.2 vs 8.7 +/- 6.1 pg/ml, p = 0.048) and its receptors, sTNFRI
(6.1 +/- 2.6 vs 1.0 +/- 0.8 pg/ml, p < 0.001) and sTNFRII (41.9 +/- 18.6 vs 6.3
+/- 3.6 pg/ml, p < 0.001) were significantly higher than those detected in a
sample of ten healthy controls. No correlation was found between nutritional
alterations and concentrations of TNF or its receptors, viral load, and counts of
CD4+ T lymphocytes/mm3. Seventeen patients completed the follow-up period. During
this period, no significant modifications in the analyzed parameters were
observed: tricipital skin fold, arm circumference, serum concentrations of
albumin or transferrin, concentrations of tumoral necrosis factor or its receptor
and caloric intake. The conclusion is that, despite the detected nutritional
alterations in the nutritional status and those in the TNF/receptor system, our
data no support and interrelationship between them.
PMID- 10687412
TI - [Preventable adverse drug effects at an emergency department].
AB - OBJECTIVE: To determine the incidence and evaluate the preventability of adverse
drug events (ADE) associated with visits to the Emergency Department at our
hospital and subsequent hospital admissions. METHODS: A six-month observational
study was conducted at an Emergency Department in a University Teaching Hospital
(October 15th, 1995, to April 15th, 1996). The parameters influencing the
preventability were identified by means of a multivariate logistic regression
analysis. RESULTS: A total of 776 ADEs (2.25%) were detected out of a total of
33,975 patients attended at the Emergency Department; 178 patients were admitted.
A total of 322 cases (43.3%) were classified as preventable and were graded as
mild (37.1%), moderate (32.5%), severe (27.4%), and fatal (3%). The logistic
regression analysis showed that preventability was related to drugs with a narrow
therapeutic index (NTI) (OR: 10.12; 95%CI: 5.36-19.07), type A ADE (OR: 4.65;
95%CI: 2.79-7.78), age > or = 65 years (OR: 3.04; 95%CI: 2.13-4.34) and self
administered medication (OR: 2.2; 95%CI: 1.32-3.65). Among admitted patients,
oral anticoagulants, NSAIDs, digoxin, diuretics, and insulin caused adverse
events which were considered as preventable in more than 50% of cases. The errors
most frequently associated with preventable ADEs included inappropriate therapy
monitoring (22.5%), increased doses with NTI drugs (22.3%), absence of preventive
therapy (14.3%), excessive dose according to patient's characteristics (13.4%),
and inappropriate self-administered medication (10%). CONCLUSIONS: The incidence
of preventable ADEs (medication errors) is high and its severity is higher than
that of non-preventable ADEs. A prompt development and implementation of measures
leading to avoiding prescription errors and inappropriate treatment monitoring,
the factors identified as responsible for preventable ADEs, is clearly warranted.
PMID- 10687413
TI - [Association of blood uric acid with other cardiovascular risk factors in the
male working population in Valencia].
AB - BACKGROUND: Serum uric acid has been reported to be a risk factor for
cardiovascular disease (CVD). The objective of the present work was to determine
the prevalence of hyperuricemia in a large size sample of a healthy male
population, as well as the association between uric acid and other cardiovascular
risk factors. PATIENTS AND METHODS: A cross-sectional study was conducted in a
randomly selected sample of 1,564 healthy men in Valencia (Spain), aged 20-67
years, working in the automobile industry. Serum values of uric acid,
cholesterol, and glucose were obtained, as well as blood pressure and body mass
index measurements. An assessment was made of socio-economic data, drug therapy,
and smoking. RESULTS: The overall prevalence of hyperuricemia was 5.10%; it
increased with age. A marked increase (p < 0.01) of hyperuricemic individuals was
observed with increased prevalence of other cardiovascular risk factors (from
1.8% with hyperuricemia alone up to 28% among individuals with four simultaneous
risk factors). By means of a multivariate logistic regression analysis, the OR of
hyperuricemia associated with each factor were calculated: increased serum
glucose was the variable with a stronger association (OR: 2.69; 95%CI: 1.21
5.99), obesity ranking next (OR: 2.50; 95%CI: 1.42-4.49). Statistically
significant associations were also observed for increased serum cholesterol,
increased blood pressure, and smoking. CONCLUSIONS: The prevalence of
hyperuricemia varies with the simultaneous presence of other classical
cardiovascular risk factors. Even in this healthy mediterranean population, uric
acid is significantly associated with several components in the plurimetabolic
syndrome.
PMID- 10687414
TI - [Borderline between emergencies and hospitalization in the analysis of hospital
mortality].
AB - BACKGROUND: The analysis of hospital mortality rate as a measure of care quality
is usually restricted to death occurred at hospital wards, and no consideration
is given to deaths occurred at the Emergency Department. Therefore, the
information from a fundamental hospital area goes without analysis. METHODS: The
following characteristics of decreased individuals at the Emergency Department (n
= 79) and hospital wards (n = 280) in the Costa del Sol Hospital (Marbella,
Malaga, Spain) during 1997 were compared: age, sex, main diagnosis at admission,
main diagnosis specificity, and number of secondary diagnoses. A reevaluation of
hospital mortality rates was made after data from ED deaths had been added.
RESULTS: The addition of deaths occurred at the ED meant a relevant increase in
hospital mortality rates: 57% for heart failure, 30% for stroke, and 25% for
myocardial infarction. Twenty percent of deaths at the ED had non-specific
diagnosis versus 5% at wards (p < 0.0001; 95%CI: 6.03; 24.15). Deaths at the ED
had 2.9 +/- 1.3 secondary diagnoses versus 4.9 +/- 2.0 in deaths at hospital
wards (p < 0.0001; 95%CI: 1.6; 2.4). CONCLUSIONS: Deaths at the ED make up a
relevant proportion of the total deaths and should be incorporated to the
hospital mortality analysis. Deficiencies in the collection of clinical
information were observed in this ED. Therefore, adjustments for severity--an
essential issue for comparing mortality rates between centers--might be
precluded.
PMID- 10687415
TI - [Malignant otitis externa and diabetes: report of 4 cases].
AB - Malignant otitis externa (MOE) is an uncommon infective but potentially fatal
entity caused by Pseudomonas aeruginosa. It involves almost exclusively advanced
aged diabetic patients. We report here four cases diagnosed at our hospital
during the last 7 years. Clinical manifestations included otalgia, purulent
otorrhoea, involvement of different cranial nerves and bony destruction; one
patient died because of bronchoaspiration and two are alive but with sequelae.
MOE should be suspected in every diabetic patient with otitis which goes
unresolved with the usual antibiotic therapy. On the other hand, facial palsy
should not always be attributed to a diabetic mononeuropathy and the presence of
MOE should be ruled out when otitis coexists or precedes it.
PMID- 10687416
TI - [Diagnostic difficulties in cystic fibrosis].
PMID- 10687417
TI - [Celiac sprue. Range of clinicobiological manifestations, current status of
diagnosis, therapeutic potential, and clinical course complications].
PMID- 10687418
TI - [Current features of antihypertensive drug treatment].
PMID- 10687419
TI - [Treatment of gout].
PMID- 10687420
TI - [Long-standing skin nodular lesions in a 14-year-old male].
PMID- 10687421
TI - [Lung nodules in a patient with HIV infection and severe neutropenia].
PMID- 10687422
TI - [Challenge in the differential diagnosis of back pain].
PMID- 10687423
TI - [Weight loss, fever, and pancytopenia in a patient with skin lesions].
PMID- 10687424
TI - [Right exophthalmos].
PMID- 10687425
TI - [Clinical course risk factors in mild craniocerebral injuries (reply)].
PMID- 10687426
TI - [Tuberculosis, AIDS, and antiretroviral therapy].
PMID- 10687427
TI - [Septic abortion caused by Campylobacter jejuni].
PMID- 10687428
TI - [Thrombocytopenic thrombotic purpura, HIV, and antiviral therapy].
PMID- 10687429
TI - [Splenomegaly and peripheral lymphocytosis secondary to splenic lymphoma].
PMID- 10687430
TI - [Fatal poisoning caused by aconitine alkaloid].
PMID- 10687431
TI - [Tuberculosis mortality in the elderly].
PMID- 10687432
TI - [Arthritis and tenosynovitis caused by Mycobacterium kansasii associated with
human immunodeficiency virus infection].
PMID- 10687433
TI - New drug approvals in 1998.
PMID- 10687434
TI - Ethical issues in the acceptance of gifts: Part 1.
AB - It brightens the day of any health care provider when a patient presents him or
her with a personal gift. These thoughtful items express sincere appreciation and
are evidence of a solid, trust-based provider-patient relationship. However,
there is a significant ethical difference between accepting small gifts of
appreciation versus gifts of great financial value. While the patient may be
expressing the same appreciation with this substantial gift, he or she may also
be attempting to curry special consideration or feel some pressure to please the
provider. In addition, acceptance of these large gifts produces the appearance of
an improper relationship between the doctor and the gift-giving patient. Patients
who offer gifts of great value should receive a sensitive explanation as to why
the gift cannot be accepted.
PMID- 10687435
TI - The importance and use of articulators in esthetic dentistry.
PMID- 10687436
TI - Esthetic improvements.
PMID- 10687437
TI - The impact of current alternative herbal remedies on dental patient management.
AB - With the recent boom in holistic and herbal medicine and an ever-growing trend
among the general population to refer to herbal remedies as an alternative to
traditional pharmaceutical therapies, dental health care providers must be aware
of the wide consumption of such products and understand their nature. It becomes
imperative, therefore, to include questions regarding the use of herbal
preparations as a matter of routine in the patient's drug history, since this may
impact a safe dental patient care delivery.
PMID- 10687438
TI - Lichen planus--report of successful treatment with aloe vera.
AB - Lichen planus is a disease that involves the skin and mucous membranes. It is
characterized by unique eruptions. The cause of this disease is unknown, but has
been linked to emotional stress, and has also been attributed to viral
infections. A case is described of a successful treatment of lichen planus.
PMID- 10687439
TI - Nonsurgical repair of furcal perforations: a literature review.
AB - The important steps in the management of a furcal perforation are immediate
action, adequate isolation, debridement, and sealing of the defect. Studies have
shown that repair materials or underlying matrix material such as amalgam, Cavit,
calcium hydroxide, glass ionomers, hydroxylapatite, tricalcium phosphate, and
demineralized freeze-dried bone have not been able to produce consistent results.
However, current research on new materials such as mineral trioxide aggregate may
advance treatment modalities significantly for furcation repair.
PMID- 10687440
TI - Endodontic working length determination--where does it end?
AB - Obtaining a correct working length is critical to the success of endodontic
therapy. Failure to identify this crucial measurement can result in untoward
treatment outcomes, which may include increased patient discomfort, possible
infection or cyst development, and extrusion or intra-canal medication into the
periradicular tissue. This article reviews the classical and current terminology,
philosophies, and techniques that are used at present to determine endodontic
working length accurately, and describes their clinical application. Recent
clinical advances such as the electronic apex locator, direct digital
radiography, and the surgical operating microscope also are discussed.
PMID- 10687441
TI - Synthetic bone grafts in peri-implant bone dehiscences: histological results in
humans.
AB - This study describes the histological results found in three patients treated
with osseointegrated implants and Bioplant HTR (Hard Tissue Replacement)
synthetic bone graft in peri-implant dehiscences adjacent to implants. This
therapy was carried out without the use of barrier membranes. Bioplant HTR is
reported to act as its own barrier and prevent gingival soft tissue migration
ingrowth. The histologic picture demonstrated that Bioplant HTR is
osteoconductive and biocompatible, and can be used both as bone substitute and as
a barrier for guided bone regeneration in implant therapy.
PMID- 10687442
TI - Anterior crossbite correction with fixed appliances in the adult dentition.
AB - Anterior crossbite in the adult dentition, if not corrected, can cause other
functional problems for the patient. These adult patients can be treated quickly
and with confidence by most general dentists with the use of pre-adjusted
appliances and straight wire. This article presents a clinical picture of three
cases involving anterior crossbite correction in the adult patient with the use
of fixed appliances and an acrylic splint.
PMID- 10687443
TI - Microleakage of two new combined primer/adhesive resin systems.
AB - In vitro microleakage of two new combined primer/adhesive systems utilizing the
all etch technique (enamel and dentin etch) with the hybrid composite resin TPH
is reported. These new combined primer/adhesive systems were compared to the
Optibond FL system, which consists of a separate primer and adhesive. Forty Class
V preparations were cut on the facial surfaces at the cemento-enamel junction of
bovine incisor teeth to a dimension of 2.0 mm x 3.0 mm x 2.0 mm with a 1.0 mm 45
degree incisal bevel. The enamel (incisal) and dentin (gingival) margins were
scored separately. Results suggest that Prime & Bond provided an improvement in
the gingival marginal seal over the other materials. There was no statistically
significant difference in the sealing ability of the materials tested at the
incisal margin.
PMID- 10687444
TI - A computerized model for teaching various methods of positioning the condyles to
centric relation.
AB - The entire masticatory system is within the realm of the dentist's
responsibility, and therefore requires the dentist to have a working knowledge
and understanding of the TMJs, neuromuscular system, and occlusion as well as the
teeth and periodontal structures. This article presents how a computerized model
can help dentists help their patients with TMJ disorders.
PMID- 10687445
TI - Oral diagnosis you can't afford to miss.
AB - The development of more predictable therapeutic modalities for the management of
periodontitis has been preceded to a great extent by a better understanding of
the underlying disease process. As the role of the immune mechanism has become
more defined in the cascade of events associated with the progressing lesions,
specific diagnostic tests are being developed to monitor the biochemical changes
in the host. These tests, in addition to microbiological monitoring, together
will help define therapeutic approaches, maintenance strategies, and endpoints in
therapy.
PMID- 10687446
TI - Atrial fibrillation: medications and dental considerations.
PMID- 10687447
TI - Sexual boundaries in dental practice: Part 2.
AB - Sexual harassment in the workplace is harmful to employees and disruptive. While
the ethical obligations arising from the doctor-patient relationship do not
address a dentist's ethical obligations toward his or her employees, the more
general ethical obligations to the profession and those of business ethics would
mediate against the creating or tolerance of sexual harassment in the workplace.
The legal implications of participating in sexual harassment or allowing it to
persist in the dental office are significant and dentists should be aware that
employees enjoy legal protections against this inappropriate and potentially
unlawful behavior. While any gender in any position may be the victim of sexual
harassment, women who occupy subordinate positions are the most likely targets of
these overtures. Dentist-employers are wise to be proactive in providing an
appropriate protocol for employees to use when they perceive sexual harassment in
the workplace.
PMID- 10687448
TI - Seating, finishing, and polishing of ceramic restorations.
AB - The insertion, finishing, and polishing of ceramic restorations can be arduous
even for the most skilled operator. Attention to details as described above and
refinement of all steps can lead to clinical success (Fig. 8-12). At this time
composite and ceramic margins cannot equal those of cast or direct gold but with
care and patience, clinically adequate results can be achieved.
PMID- 10687449
TI - A comparison of all-ceramic restorative systems, Part 1.
PMID- 10687450
TI - The oral implications of Hodgkin's disease.
AB - Hodgkin's disease is a cancer involving the lymphatics. While the yearly total of
new cases is only approximately 7,500, the disease is very curable with modern
radiotherapy and/or combination chemotherapy. This represents an increasing
number of survivors who require dental treatment. Unfortunately, the treatment
for Hodgkin's results in significant, permanent complications that persist for
the duration of the patient's life. These complications can include xerostomia,
radiation-induced caries, the risk of osteoradionecrosis in irradiated bone, and
systemic complications such as a reduced immune response to microorganisms. These
patients can and do undergo all types of dental treatment safely as long as the
practitioner recognizes the risks involved and takes appropriate precautions.
PMID- 10687451
TI - Scleroderma: what the general dentist should know.
AB - Scleroderma is characterized by fibrotic changes of the skin and organ systems.
The disease presents in a variety of forms, ranging from the most aggressive
progressive systemic sclerosis (PSS), to the three less aggressive, CREST
syndrome, morphea, and the more localized form, linear scleroderma. The oral
manifestations of the disease result from deposits of collagen in the tissues or
as a result of collagen deposition around nerves and vessels. All oral tissues
are affected. In scleroderma patients, the oral manifestation most commonly
recognized is wide periodontal ligament spaces. Limited function, impaired
healing, and neurologic symptoms all may be present to varying degrees, depending
on the form and progression of the disease.
PMID- 10687452
TI - Not all patients are the same: systemic risk factors for adult periodontitis.
AB - Periodontal diseases are viewed today as multifactoral problems that are
initiated and sustained by bacteria but significantly modified by the body's
response to bacterial plaque. Local and systemic risk factors are involved in the
disease process and both should be included when prognosis and treatment plans
are developed. The most significant systemic modifying factors appear to be
smoking, diabetes, and a recently discovered genetic marker. Slight changes in
genes that produce an important inflammatory mediator, found in one-third of
those studied, can lead to major negative outcomes in the way the body responds
to bacteria.
PMID- 10687453
TI - Nonsteroidal anti-inflammatory drug use in dentistry: gastrointestinal
implications.
AB - Pain management long has been an important consideration in dental care.
Nonopioid analgesics such as aspirin, acetaminophen, and many of the nonsteroidal
anti-inflammatory drugs (NSAIDs) generally provide predictable outcomes for
control of dental pain because of their analgesic and anti-inflammatory
properties. The anti-inflammatory action of NSAIDs also is being investigated in
treatment of periodontal disease when used as an adjunct to non-surgical
management. Since NSAID use by dental patients is high, gastrointestinal
complications may arise, affecting long-term use of these agents. Systemic
considerations of NSAID use are reviewed, as are complications frequently
resulting in ulceration of the gastric mucosa.
PMID- 10687454
TI - Dentists at high risk for hearing loss: protection with custom earplugs.
AB - This article provides information on the effects of noise, especially to
dentists. It gives information on how to protect one's hearing and furnishes a
technique to fabricate custom earplugs.
PMID- 10687455
TI - Simplifying the bead-brush technique.
AB - This article describes a method of controlling monomer addition using the bead
brush technique. With the addition of a cotton pellet to the monomer,
incorporation of liquid can adequately be controlled.
PMID- 10687456
TI - Resin-bonded fixed partial denture: a contemporary prosthesis.
AB - This review of the evolution of the resin-bonded fixed partial denture (RBFPD)
design, from the original "prepless" restoration to the present prosthesis,
requiring careful treatment planning and technical skill, also discusses the
materials used to enhance the longevity of this restoration. That, in turn,
increases the patient's confidence in both the dentist and the prosthesis itself.
PMID- 10687457
TI - Adult orthodontic treatment: a challenging case report.
AB - The case of a 61-year-old woman with a primary diagnosis of spondyloepiphyseal
dysplasia and severe maxillary and mandibular spacing as well as anterior and
posterior crossbites is presented. Clinical findings led to a diagnosis of
macroglossia which required partial glossectomy in addition to comprehensive
orthodontic treatment to correct malocclusion.
PMID- 10687458
TI - Enhanced fixed prosthetics with a connective tissue ridge augmentation.
AB - Augmentation of the partially edentulous ridge can significantly improve the
final prosthetic result. The subepithelial connective tissue graft is the
treatment of choice to enhance soft tissue contours. The major advantage of the
connective tissue graft is the preservation of the existing gingival coloration
and tissue characteristics. A case is described that utilizes the subepithelial
connective tissue graft for augmentation of a maxillary anterior ridge prior to
prosthetic rehabilitation.
PMID- 10687459
TI - In memoriam William W. Howard, DMD, MAGD.
PMID- 10687460
TI - Antifungal drugs and fungal resistance: the need for a new generation of drugs.
PMID- 10687461
TI - Ethical issues in the acceptance of gifts: Part 2.
PMID- 10687462
TI - The use of indirect composite and ceramic inlays to restore anterior teeth: a
clinical case report.
AB - A clinical case has been presented utilizing old inlay techniques with new
materials. The teeth were restored to proper form, function, and esthetics with a
minimal removal of tooth structure. Crowns were not necessary, thereby
eliminating a margin near the gingiva, and esthetics were acceptable.
PMID- 10687463
TI - Evidence-based dentistry: an overview of a new approach to dental practice.
AB - Dental students' clinical questions and problems are solved by a combination of
instructors' intuition, training, and clinical experience, which may or may not
be based on scientific evidence. This type of training, which relies heavily on
clinical experience and information learned in dental school, seminars, or from
colleagues, can lead to inappropriate treatment outcomes. Evidence-based
dentistry attempts to answer clinical questions based on a critical review of the
best available scientific evidence together with one's clinical experience and
scientific knowledge.
PMID- 10687464
TI - Adjunctive diagnostic methods for monitoring progressive periodontal diseases.
AB - Diagnosing periodontal diseases involves determining the classification of the
disease and the recognition of disease severity at the time of the clinical
examination. Traditional diagnostic methods, such as radiographs and periodontal
probing, have several limitations. Newer diagnostic techniques have been
developed that could help determine whether specific sites are actively breaking
down or if the site will experience future active disease. The newest technique
is a genetic susceptibility test to identify patients who are at an increased
risk for periodontal disease before problems develop. The screening of at-risk
patients after initial therapy with these newly developed monitoring tests may
lead to improved treatment and prevention of periodontal disease.
PMID- 10687465
TI - Determining when to refer periodontal patients--clinical guidelines.
AB - As part of the examination and evaluation of the patient, it is the dentist's
responsibility to evaluate the periodontal tissues for the presence or absence of
periodontal disease. If the practitioner finds that periodontal disease is
present and is unwilling or unable to accurately diagnose and/or treat the type
or extent of the disease, the dentist must offer the patient the opportunity to
be evaluated by a practitioner who can complete the examination and diagnostic
process.
PMID- 10687466
TI - Interdisciplinary management of a common esthetic complaint.
AB - Esthetic restoration of the maxillary anterior dentition often requires an
integrated perio-restorative team approach. Careful attention to treatment
planning and treatment sequencing is essential in ensuring a desirable outcome
and a satisfied patient. Detailed measurements, diagnostic wax-ups, surgical mock
ups, and stents all are effective communication tools which can be used to
enhance interdisciplinary communication. These concepts and treatment modalities
are illustrated in this case report.
PMID- 10687467
TI - Repair of a root perforation with a resin-ionomer using an intentional
replantation technique.
AB - The repair of a root perforation can be accomplished using different materials
and techniques. When the defect is surgically inaccessible, the tooth can be
carefully extracted, repaired extraorally, and placed back into the socket. This
procedure, known as intentional replantation, is often a measure of last resort
in an heroic effort to save a hopeless tooth. This case report describes the
treatment of a tooth with an iatrogenic root perforation and the subsequent
healing of the surrounding periodontium using an intentional replantation
technique and resin-ionomer to repair the root defect.
PMID- 10687468
TI - Stable matrix for amalgam build-up.
AB - A method is proposed of making amalgam build-ups for coronally debilitated teeth
through the use of a stable matrix consisting of a disposable tray and
polyvinylsiloxane occlusal registration material. For teeth with minimal
remaining coronal tooth structure and/or the absence of adjacent teeth, this
technique provides proper stabilization of the matrix band to permit adequate
condensation of amalgam.
PMID- 10687469
TI - Communicating with patients.
AB - Dental care providers need to be able to communicate effectively with their
patients in order to build rapport and trust. Highly developed communication
skills also enable the dental care provider to extract more accurate diagnostic
information and to more effectively present treatment options to the patient.
Neurolinguistic programming techniques can be employed to accomplish these as
well as other objectives.
PMID- 10687470
TI - Fracture resistance of endodontically treated teeth restored with bonded amalgam
and full crowns.
AB - The use of dentin bonding prior to placement of core build-up restorations has
been shown to reduce microleakage and reinforce remaining tooth structure.
However, information is lacking about the influence a core build-up has on the
fracture resistance of crowned teeth. The purpose of this in-vitro study was to
compare the influence of three types of core build-ups on the fracture resistance
of crowned teeth.
PMID- 10687471
TI - Single appointment amalgam crown procedure for posterior teeth.
AB - When faced with the restoration of severely broken-down posterior teeth, many
treatment options exist. Expense, time constraints, and periodontal health, as
well as the needs and desires of the patient, all play a role in the selection of
treatment modality. In many instances, a well-fabricated amalgam crown can
provide a highly acceptable functional restoration in the posterior region. Here,
the amalgam crown is discussed in relation to other options and several case
reports are presented.
PMID- 10687472
TI - Oral Kaposi's sarcoma in a non-AIDS patient.
AB - Kaposi's sarcoma involving the oral cavity is seen frequently in AIDS patients
but rarely in transplant patients. When the oral cavity is involved in transplant
patients, it usually is located on the palate or the oropharynx. This article
reports a renal transplant patient who developed Kaposi's sarcoma which mimicked
a gingival hyperplasia in the oral cavity.
PMID- 10687473
TI - Tobacco "plantibodies" for caries prevention.
PMID- 10687475
TI - Effects of light intensity, time, and direction on gap formation of resin
composite restorations.
PMID- 10687474
TI - Sexual boundaries in dental practice: Part 1.
AB - Sexual contact between doctors and patients is unethical, legally perilous, cause
for professional discipline at times, and often viewed as an outrageous
transgression by the public. While it is true that some provider-patient couples
go on to get married and "live happily ever after," this is not always the case.
However, if these relationships fail, a now embittered ex-paramour is empowered
with the options of bringing legal and/or disciplinary action against the doctor
and may be motivated by the distinct possibility of significant financial reward.
Patients place enormous trust and respect in their health care providers. In
addition, patients reveal sensitive, confidential information to doctors and do
so with the expectation that it will be used only for their best interests. This
dynamic creates a substantial power imbalance between doctors and patients and
this power differential must never be exploited. Dentists who find themselves
romantically attracted to patients must either avoid initiating a more intimate
relationship or refer the patient to another provider. Dentists who are the
recipients of romantic inquiries by patients should establish clear boundaries.
If the dentist is available and interested in the patient, dating may occur only
after the patient has been reassigned to another dentist and a suitable time
period has elapsed.
PMID- 10687476
TI - Treatment plan case report.
PMID- 10687477
TI - A day at the office (an advertorial).
AB - This issue of General Dentistry highlights how tobacco products affect oral
health. The following articles are presented to help general dentists with their
efforts to champion cessation and to educate their patients. Please also note the
guest editorial from Dr. Robert Mecklenburg. This first article by Dr. Stephen B.
Corbin is an introduction to the topic at large and provides the reader with a
suggested script for use in helping patients quit the smoking habit. We hope you
find these articles useful and look forward to hearing your response. Please fax
(312/440-4261) or e-mail (AGDJournal@agd.org) your thoughts on these articles. We
hope these articles succeed in helping you help your patients beat the tobacco
habit.
PMID- 10687478
TI - Tobacco cessation: a practical dental service.
AB - Tobacco use is a complex addiction that must be addressed in all aspects of
health care. Despite the deleterious and costly outcomes of tobacco use,
Americans still are smoking and using smokeless tobacco. Dentists are trained to
detect oral lesions and periodontal problems that are related to tobacco use.
Dentists also are in a position to help prevent the initiation of tobacco use by
children and adolescents through the use of positive anti-tobacco messages. Over
the past decade, tobacco cessation strategies have been modified for practical
use in the dental setting.
PMID- 10687479
TI - Tobacco and dental implants.
AB - Dental implants are the ideal standard of care for many oral health care
providers. Tobacco use is an impediment to the success of this sophisticated
procedure. Dentists who are trained to help their patients stop using tobacco are
in position to improve their success rates with dental implants. A suggested
protocol for tobacco cessation in the implant practice, if utilized, could raise
the standard of health care in the dental office.
PMID- 10687480
TI - Canal configuration of the mesiobuccal root of the maxillary first molar:
conventional and surgical approaches.
AB - One of the primary causes of endodontic failure is the presence of untreated
canals. Although the maxillary first molar has been described as the most
endodontically treated tooth, the canal configuration has been the least
understood. The purpose of this article is to present, with the aid of several
clinical cases, a review of the literature regarding the frequency, the location,
and the incidence of the second mesiobuccal canal in relation to the maxillary
first molar, both for conventional and surgical approach.
PMID- 10687481
TI - Prevalence and implications of accessory retromolar foramina in clinical
dentistry.
AB - The occurrence of retromolar foramina (RMF) was examined in a sample of dry
skulls (African American n = 249; Causcasian n = 226) to consider the potential
clinical impact. A prevalence rate of 7.8% of RMF was found. There were no
statistical differences based on race or gender. The prevalence may contribute to
the explanation of a portion of inferior alveolar nerve block failures and
provide insight into potential implications of surgery in the posterior mandible.
PMID- 10687482
TI - Using soft splints in your dental practice.
AB - A significant number of soft splints are fabricated by U.S. dentists every year.
The efficacy of these splints is discussed, reported indications and
contraindications are defined, and favorable and unfavorable characteristics
reported by patients are presented. Maxillary and mandibular soft splint designs
that have been found to be clinically acceptable are illustrated and an easy and
rapid technique for adjusting and polishing a soft splint is proposed.
PMID- 10687483
TI - The free gingival graft combined with the frenectomy: a clinical review.
AB - Abnormal labial frena are capable of retracting gingival margins, creating
diastemas, and limiting lip movement. When these frena are present, the
traditional frenectomy alone generally is successful. However, when the frenulum
is extensive, the possibility of coronal reformation exists. Several procedures
have combined the frenectomy with either a lateral pedicle flap, free papilla
graft, or free gingival (mucosal) graft taken from the palate. Three case reports
demonstrate the continued efficacy of the traditional palatal free gingival graft
when the patient has an extensive frenulum or an area of minimal esthetic concern
is involved.
PMID- 10687484
TI - Effective use of the ortho-panoramic radiograph during the doctor-patient
conference.
AB - Tracings of pre-treatment radiographs can be used to clarify the case
presentation and be inserted into the permanent record. The use of different
colors on the photocopy can highlight or demonstrate various conditions or steps
in treatment to enhance the patient's understanding. Various other uses for such
tracings are suggested.
PMID- 10687485
TI - Everything you wanted to know about radiographic duplication.
AB - If dental radiographs are not duplicated correctly, the resulting duplicates will
be of inferior quality. This article discusses the characteristics of a
duplicating film, the principle of radiographic duplication, a description of
dental duplicators, the selection of optimum duplicating time, a technique of
duplicating radiographs, an alternate technique of duplicating radiographs,
errors in duplication and their correction, and the maintenance of duplicators.
PMID- 10687486
TI - Gingival augmentation with a dermal allograft.
AB - Gingival augmentation surgery with soft tissue autografts long has been the
standard for increasing the width of keratinized oral tissue. Acellular dermal
allografts, which have been used for several years by reconstructive surgeons,
are a novel technique for achieving increased gingival tissue in place of soft
tissue autografts. This report describes a case of gingival augmentation via an
acellular dermal allograft. Reduced morbidity from donor site grafts and
increased patient acceptance, along with highly successful clinical results, are
the primary advantages of this acellular dermal allograft.
PMID- 10687487
TI - Recent reports calling for reduction of antibiotic prophylaxis in dental
procedures: a response.
PMID- 10687488
TI - Managed care--serving two masters.
AB - It is likely that enrollment in managed care dental plans will continue to
increase. Dentistry can respond to this trend by resisting it; however, just as
the health care marketplace drove medical care into managed care mechanisms, so
too will these forces impact dentistry. For those who are participating in
managed care dental plans, it is heartening that current data indicate that most
types of patient care are not adversely affected by reimbursement mechanisms.
Dentistry, however, should seek out opportunities to shape the managed care
format and must be at the table to assure that ethical principles and conflicts
of interest receive due consideration. Dentists who treat patients under a
managed care reimbursement system must be certain that the plan does not require
providers to sacrifice patient autonomy or compromise care in the process of
serving two masters.
PMID- 10687489
TI - Indirect provisional restorations.
AB - Many methods of provisional restoration fabrication are available to practicing
dentists. The indirect method has been found to be the most accurate and least
time consuming for the author as well as many other clinicians. After a little
practice and familiarity with the methods and materials the restorative dentist
will realize the benefits for both the dentist and the patient.
PMID- 10687490
TI - Percutaneous injuries among dental health care workers.
AB - To evaluate percutaneous injuries among dental health care workers this survey
posed two questions: Is there a difference in the number of percutaneous injuries
occurring among dentists, dental hygienists, and dental assistants, and Is there
a difference in the number of injuries that occur intraorally or extraorally
among dental health care workers as a whole, and within each occupational group?
This prospective study included demographic information and an incident report.
The incident report tabulated type of injury (intraoral or extraoral), procedure
during which the injury occurred, and type of instrument that caused the injury.
PMID- 10687491
TI - Disinfection and monitoring of dental unit waterlines.
AB - Recent increased awareness of dental unit waterline contamination has prompted
investigations into potential protocols for improvement in the quality of water
delivered to patients. When the protocol was followed (n = 12), contamination
levels were reduced to below measurable colony forming units (CFU) defined as < 1
CFU/mL within three weeks and maintained thereafter. When adherence to the
protocol was not strictly followed after initial disinfection, contamination
quickly returned and remained until additional disinfection was performed.
PMID- 10687492
TI - Evaluation of sterilization of dental handpieces by heating in synthetic
compressor lubricant.
AB - The Centers for Disease Control and Prevention and the American Dental
Association guidelines recommend sterilization of dental handpieces after each
use. Steam autoclaving is the most commonly used sterilization method. However,
pressurized steam causes corrosion and partial combustion of the handpiece
lubricant, leaving a sticky carbon residue on the turbine which must then be
replaced after several usages. Replacement of autoclave-damaged dental handpieces
represents a major expense for dentists that may be avoided through the use of
less destructive sterilization techniques.
PMID- 10687493
TI - Irrigation with antimicrobial agents for the treatment of periodontitis--is it
effective?
AB - Subgingival irrigation has been proposed as a beneficial adjunct to scaling and
root planing or ultrasonic scaling. The most commonly investigated agents are
iodine and chlorhexidine. Clinical studies from the past 15 years are reviewed to
determine the real benefits of antimicrobial irrigants in conjunction with root
planning. With knowledge of the treatment protocols and results of these clinical
studies, the clinician is equipped with a biologic rationale for his treatment
decisions in nonsurgical periodontics.
PMID- 10687494
TI - Site specific delivery of antimicrobial agents for periodontal disease.
AB - Controlled release delivery systems have become available for the sustained
delivery of antimicrobial agents directly to the periodontal pocket. These
systems have shown clinical efficacy in periodontal therapy both as adjunctive
treatments and as stand-alone therapies. A review of the current state-of-the-art
of site specific delivery of antimicrobial agents for the treatment of
periodontal disease is provided.
PMID- 10687495
TI - Differential diagnosis of pericoronal radiolucencies with and without
radiopacities.
AB - Pericoronal radiolucencies, by definition, surround the crown of a tooth. They
are encountered not only in pediatric patients but also in adults of all ages. It
is likely that all clinicians, at some time or another, will be confronted with a
radiograph showing a pericoronal radiolucent lesion. The differential diagnosis
of such lesions is reviewed.
PMID- 10687496
TI - Antimicrobial activity of cavity disinfectants.
AB - The purpose of this study was to determine the antimicrobial activity of four
commercially available cavity disinfectants and one prescription mouthwash as
they came into contact with bacteria commonly found in the oral cavity.
Streptococcus mutans, salivarius, and Actinomyces viscosus were used in the
study. Zones of microbial inhibition were measured in millimeters after 48 hours.
The results of this study indicate that all of the antimicrobial agents
demonstrated activity against the bacteria tested. Consepsis Solution produced
the largest zones of inhibition against all three of the bacteria used.
PMID- 10687497
TI - To place provisionals or not--that is the question.
AB - Porcelain labial veneers are quite possibly the most esthetic restorations that
can be provided today. Their esthetic qualities are derived not only from the
accurate replication of tooth structure, but also from the superior tissue
response they elicit. Many of the procedures surrounding this restoration have
become almost standardized in terms of preparation and the manner in which the
restoration is made to become part of the tooth. But why experts who lecture
about this procedure remain at odds about whether provisional restorations are
necessary is baffling. As more tooth preparation became increasingly necessary to
achieve the ultimate in esthetics and health, use of the provisional restoration
was not incorporated, simply as a matter of established routine.
PMID- 10687498
TI - Effect of glutaraldehyde-based cold sterilization solutions on light transmission
of single-use, plastic light-curing tips.
AB - Previous research has demonstrated that autoclaving of conventional curing tips
results in the build-up of an opaque scale on the curing tips ends, greatly
reducing light intensity output. Cold sterilization of conventional light-curing
tips in most glutaraldehyde-based solutions did not damage the tip or decrease
light-transmission quality. However, the specific brand of cold sterilant was
found to be of importance, as one specific product was shown to decrease light
tip intensity values irreversibly, even after subsequent tip polishing. A
decrease in light intensity output from the curing source significantly affects
polymer cure and the biological properties of the restorative material.
PMID- 10687499
TI - Treating enamel surfaces with a prepared pumice prophy paste prior to bonding.
AB - The use of pumice to remove the salivary pellicle, plaque, and/or surface debris
is a well-known procedure. However, pumice can act as a contaminant. Therefore, a
slurry of pumice without additives is recommended for use prior to bonding
procedures. This article presents a review of the shear bond strengths obtained
by bonding composite resin to enamel after the enamel had been cleansed with a
slurry of pumice and a premixed caplet of pumice.
PMID- 10687500
TI - A new and indirect working die technique for fabricating temporary restorations.
AB - A time- and labor-saving indirect method for fabricating temporary restorations
that features removable dies (coined the indirect working die technique), is
introduced and described. It takes advantage of the accuracy of the traditional
indirect method, as substantiated in the literature, but employs new methods and
uses materials in a novel way.
PMID- 10687501
TI - Dual-purpose, radiographic-surgical implant template: fabrication technique.
AB - A technique for fabrication of an implant radiographic-surgical template for the
partially-edentulous patient is proposed. A mixture of barium sulfate and acrylic
resin provides a radiopaque template of the planned implant restorations in
relation to the hard tissues. This template is easily converted to a surgical
guide.
PMID- 10687502
TI - The impact of managed care in dentistry.
AB - Managed care plans attempt to control health care expenditures aggressively.
These plans directly influence access to medical care and the type, level, and
frequency of care rendered. As a result, hospital stays are reduced, focus shifts
from inpatient to outpatient care, and patients are responsible for a larger
share of health care costs. Dentistry is not immune from the impact of managed
care. The attractiveness of the dental market has drawn many managed care
organizations, insurers, and entrepreneurs to encourage dentists to participate
in a wide variety of managed care programs. However, the delivery of dental care
differs markedly in many respects from that of medical care. Therefore, many of
the cost saving aspects of managed care that have been so successful in medicine
may not result in similar cost savings in dentistry.
PMID- 10687503
TI - Double blind clinical trial of a remineralizing dentifrice in the prevention of
caries in a radiation therapy population.
AB - OBJECTIVES: The purpose of this study is to determine the efficacy and safety of
a specially formulated remineralizing toothpaste in controlling caries in a group
of high risk, head and neck radiation patients. DESIGN: The study compares the
performance of the remineralizing toothpaste with a leading conventional fluoride
dentifrice using double-blind randomization. TEST PRODUCTS: The products compared
both contain equivalent quantities of fluoride (1150 ppm). The remineralizing
toothpaste also delivers soluble calcium and phosphate ions, the essential
components of teeth. SUBJECTS: On completion, 50 subjects who received > 50 Gy of
radiation to the head and neck. MEASUREMENTS: Examinations include coronal and
root caries using the Pitts Diagnostic Criteria, salivary flow rate, plaque and
gingival indices and microbiological counts over one year. RESULTS: At this point
subjects are enrolled in the study at various phases. However, the current
average for the net increment per month per subject is -0.12 (+/- 1.30) for
coronal caries and 0.06 (+/- 0.73) for root caries in subjects using the
remineralizing toothpaste and 0.53 (+/- 1.62) for coronal caries and 0.45 (+/-
0.98) for root caries in subjects using the conventional fluoride dentifrice. Non
parametric analysis of rank scores for net root surface increments/month was
statistically significant (p = 0.02), suggesting lower net root surface
increment/month for the remineralizing toothpaste relative to the conventional
toothpaste. No significant differences were noted on coronal surfaces.
CONCLUSIONS: The results to date indicate that the remineralizing toothpaste is
significantly superior to the conventional fluoride dentifrice in preventing root
caries in high risk patients.
PMID- 10687504
TI - The impact of oral health on stated ability to eat certain foods; findings from
the National Diet and Nutrition Survey of Older People in Great Britain.
AB - OBJECTIVES: To assess how the dental status of older people's mouths affected
their stated ability to eat common foods. DESIGN: Cross sectional study.
SUBJECTS: Survey was part of the oral health component of the nationwide British
National Diet and Nutrition Survey: people aged 65 years and older. Two separate
representative samples aged 65 and over: a free-living and an institutional
sample. 881 free-living and 275 institution subjects had a dental exam and were
interviewed about ability to eat key foods. RESULTS: Significant percentages of
free-living people had difficulty or could not eat at least 4 of 16 foods, and
about 1 in 5 dentate stated they had difficulty eating or could not eat raw
carrots, apples, well-done steak or nuts. More of the edentate subjects stated
that they had difficulty eating than the dentate. Perceived chewing ability
increased with increasing numbers of natural teeth and pairs of opposing
posterior teeth. Subjects reporting a sociodental impact were more likely to
consider that they were unable to eat foods that required more chewing.
Associations remained valid after correction for the effects of age, sex, social
class and denture wearing status and region. Perceived dryness did not affect
significantly the stated ease of eating most foods. There were more dietary
restrictions reported by the institution sample. Some foods, such as nuts, apples
and raw carrots could not be eaten easily by over half of edentate people in the
institution sample. CONCLUSIONS: The stated selection of foods are substantially
affected by numbers of teeth and occluding pairs of posterior teeth and presence
of full dentures in significant percentages of older people.
PMID- 10687505
TI - Socio-medical condition and oral functional status in an older institutionalised
population.
AB - OBJECTIVES: To investigate the association between the general medical condition,
the socio-economic status, and some factors related to the functional status of
the stomatognathic system. DESIGN: A survey in an elderly population. SUBJECTS:
257 older adults, with a mean age of 83.7 years. SETTING: Residential homes for
the elderly. INTERVENTION: Examination of the medical records on the overall
health and the drugs consumed, a structured interview on the socio-economic
status, the complaints for xerostomia, the subjective chewing difficulties, and a
clinical evaluation of the number of natural teeth and the number of posterior
occluding pairs of teeth contacts (premolars and molars). RESULTS: Multiple
pathology and polypharmacy were recorded. 25% of the residents had no occluding
posterior tooth contact (natural or prosthetic) and 62% were edentulous. 43% of
the residents reported complaints for xerostomia, and 46% for chewing
difficulties when eating specific food types. Xerostomic feelings and chewing
problems were not related to age. Chewing difficulties were not related to the
number of natural teeth, but to the number of posterior occluding teeth contacts,
natural or prosthetic (less than two). From all medical conditions examined, only
the psychiatric disorders were significantly related to dental status (p < 0.05).
Moreover, the number of remaining natural teeth was related to socio-economic
status, while the number of posterior occluding teeth contacts was also inversely
related to the duration of institutionalisation (p < 0.05). CONCLUSIONS:
Psychiatric disorders, low socio-economic status and increased duration of
institutionalisation were most closely related to poor dental status. The
presence of more than two posterior occluding teeth contacts, natural or
prosthetic, benefit the very old patient in terms of reduced subjective chewing
difficulty. A formal oral care delivery system for the institutionalised elderly,
and particularly for those suffering from psychiatric disorders, is imperative.
PMID- 10687506
TI - Age-related changes in cellular activity in human submandibular glands as
evaluated by argyrophilic nucleolar organizer regions.
AB - OBJECTIVE: To examine the age-related changes in cellular activity of epithelial
components of human submandibular glands, evaluated on the basis of argyrophilic
nucleolar organizer regions (AgNORs). DESIGN: Epithelial components of human
submandibular glands were divided into serous acinar cells, mucous acinar cells,
intercalated duct cells, striated duct cells, and interlobular duct cells. The
mean AgNOR number of each cell type was compared among six age groups. SETTING:
The study was conducted at the Department of Oral Pathology, Tohoku University
School of Dentistry, Japan. SUBJECTS: Necropsy specimens from 66 males and 57
females 1 to 97 years old. RESULTS: In all cell types except for intercalated
duct cells, the mean AgNOR number was lowest in the 0-14 year-old group and
highest in the 15-29 year-old group. The value then gradually decreased with
advancing age and ultimately reached a similar level to that in the 0-14 year-old
group. In intercalated duct cells, the mean AgNOR number did not differ
significantly between any age group. There were no significant sex-related
differences. CONCLUSIONS: The cellular activity of almost all components of human
submandibular glands rises in adolescence and young adulthood and then decreases
with aging. These results suggest that intercalated duct cells are capable of not
only proliferation but also division into other components; these cells may thus
compensate for the reduced activity of other components in elderly subjects.
PMID- 10687507
TI - Factors which are associated with dental decay in the older individual.
AB - OBJECTIVES: To improve reliability of salivary bacterial cultures as a surrogate
for plaque levels of cariogenic bacterial species by reporting the salivary CFUs
of these organisms as a function of the number of teeth. DESIGN: Cross-sectional
collection of data in a convenience sample of adults over 60 years of age.
SETTING: Hospital Dental clinic, University bacteriology laboratory. SUBJECTS:
523 older dentate subjects, average age 70, including 412 subjects who were in an
independent living status and 111 in a dependent-living situation. MAIN OUTCOME
MEASURES: Subjects were examined for decay and the presence of salivary factors
including the levels of S. mutans, lactobacilli, yeast and other bacteria. The
salivary levels of the bacteria were adjusted for the number of teeth in the
mouth, and the resultant values were entered into multivariable logistic
regression models along with clinical and other salivary parameters. RESULTS:
Mutans streptococci levels reported as CFUs/ml saliva per tooth were
significantly associated with coronal surface decay, and lactobacilli, reported
in a similar way, were significantly associated with root surface decay. Salivary
levels of yeasts, which had previously been associated with decay in this
population, were no longer significant using this construct. CONCLUSIONS: This
construct of reporting salivary bacteriological data as a function of tooth
number and per ml saliva could improve the reliability of bacteriological data
obtained in epidemiological studies investigating the role of bacteria in dental
decay in the elderly.
PMID- 10687508
TI - Caries activity and associated risk factors in elderly hospitalised population-
15-months follow-up in French institutions.
AB - Only a few studies have been published concerning hospitalised elderly disabled
people. OBJECTIVES: 1) to investigate the oral health status of elderly French
patients hospitalised in the two main geriatric hospitals of Paris. 2) to
describe the respective influences of general parameters (type of
hospitalisation, pathologies and medication) on oral environment parameters. 3)
to analyse the influences of these oral parameters on caries activity in Long
Term Care (LTCF) and in rehabilitation facilities (RF) patients and to study the
incidence and the time-course of caries in these specific population. SUBJECTS:
117 subjects (mean age = 83.0 years, SD = 7.8, range = 64 to 102 years) were
examined at baseline and 32 of the 50 LTCF subjects were reexamined 15-months
later. METHODS: The general parameters recorded were age, gender, type of
hospitalisation, period of stay, removable prosthesis, general diseases, number
of diagnoses, medications with hyposalivary side-effects. The oral environment
parameters recorded were flow rate, buffer capacity, mutans streptococci and
lactobacilli counts, measured at baseline by tests on stimulated saliva, and
plaque index. Crown and root surfaces were recorded according to a modified
caries activity index. RESULTS: Among the polypathological subjects (85.5% of the
population), the number of diseases ranged from 2 to 8. The LTCF patients had a
significantly higher mean number of diagnoses (3.5; SD = 1.5) than the RF
patients (2.8; SD = 1.4). 76.9% of patients were taking medications with
hyposalivary side-effects. The stimulated flow rate ranged from 0.02 ml/min to 5
ml/min. Its mean was significantly lower for LTCF patients (0.67 ml/min; SD =
0.51) than for RF patients (1.12 ml/min; SD = 0.89). The plaque index was
significantly higher in LTCF subjects and in patients with mental diseases. At
baseline, 17,442 crown and root surfaces were examined. Flow rate was related to
crown caries and buffer capacity to root caries. During the 15-months follow-up,
the mean number of active root surfaces was significantly increased: from 0.148
(SD = 0.116) at baseline vs. 0.250 (SD = 0.174) at the second examination.
CONCLUSIONS: The strongest relationship in the present study between oral
parameters and caries activity was the negative relationship between buffer
capacity and active root caries. This study confirms an association between the
type of hospitalisation and both salivary parameters flow rate and plaque index.
This investigation illustrates the critical need for hygiene and oral care, in
this elderly disabled population.
PMID- 10687509
TI - The importance of oral health to older people's quality of life.
AB - OBJECTIVES: This study was designed to determine whether older people perceive
oral health as being important to Quality of Life (QoL) and if so, to identify
the most important ways in which their lives are affected. In addition, to
identify if subgroups of older people perceive its importance differently.
DESIGN: Nationwide qualitative face to face interviews with older people were
carried out utilising the Office for National Statistics Omnibus survey in Great
Britain. SUBJECTS AND METHODS: 454 adults aged 65 or older took part in this
study, part of a random probability sample of adults in the UK. SETTING:
Respondents were interviewed in their homes. RESULTS: 72% (313) perceived their
oral health status as important to their QoL through a variety of physical,
social and psychological ways. Most frequently its impact on function: eating
(29%, 126) and symptoms: comfort (14%, 59) were considered most important. Gender
and social class variations were apparent (P < 0.05). CONCLUSION: Older people
perceive oral health as being important to life quality in a variety of different
ways. There are significant social class and gender variations which must be
taken into consideration when assessing oral health needs of older people.
PMID- 10687510
TI - Effect of different grades of gum rosins and hydrogenated resins on the
solubility, disintegration, and dimensional alterations of Grossman cement.
AB - In the present study, we investigated the effect of the addition of different
grades of gum rosins and hydrogenated resins to Grossman cement on dimensional
stability, solubility and disintegration. pH and conductivity, which may affect
these properties, were also determined. The experiments were performed according
to Specification 57 of the American Dental Association for root canal cements
using Grossman cements containing three gum rosins (grades X, WW, and WG) and two
hydrogenated resins (Staybelite and Staybelite ester 10). The results showed that
the solubility, disintegration, and dimensional stability of Grossman cement
containing Staybelite and Staybelite ester 10 were inferior to the values
considered acceptable by the American Dental Association Specification 57.
PMID- 10687511
TI - In vitro release of hydroxyl ions from calcium hydroxide gutta-percha points.
AB - In endodontic practice, calcium hydroxide is widely used for a number of reasons
associated with its high pH. The purpose of the present study was to determine in
vitro the alkalizing potential of newly introduced calcium hydroxide gutta-percha
points that are proposed for temporary filling of root canals. The materials
tested were: calcium hydroxide gutta-percha points; chemical pure calcium
hydroxide powder mixed with distilled water; and Reogan rapid, a nonsetting
calcium hydroxide preparation. The materials were placed into dialysis tubing and
transferred into plastic vials containing bidistilled water. Measurements were
taken by a digital pH meter after 10, 20, and 30 s; 1, 15, and 30 min; and 1, 2,
3, 24, 48, 72, 96, and 120 h. The calcium hydroxide containing gutta-percha
points showed a significantly lower alkalizing potential than Reogan rapid and
calcium hydroxide mixed with distilled water (p < 0.05).
PMID- 10687512
TI - Scattering of laser light directed onto the labial surface of extracted human
upper central incisors.
AB - The purpose of this study was to evaluate the scatter of light through human
teeth with laser Doppler flowmetry. An optical probe (probe 1), which mounted two
optical fibers (one for light illumination and another for the measurement of
backscattered light intensity) was placed on the labial surface of the extracted
teeth. Another optical probe (probe 2) for the measurement of transmitted-light
intensity was placed either on the mesial, distal, or palatal surface or in the
canal of the teeth. The light intensity at probe 1 was stable, irrespective of
the location of probe 2, whereas the transmitted light intensity at probe 2
tended to increase as probe 2 moved to more incisal positions on the mesial,
distal, and palatal tooth surfaces. The results indicate that the light scatters
to a wide area outside the tooth and provides information regarding the
surrounding tissue blood flow.
PMID- 10687513
TI - Changes in the periodontal membrane due to apical periodontitis.
AB - Teeth with an apical inflammatory lesion were studied by light microscopic
morphometrical procedures to estimate the volumetric density of periodontal
ligament tissues by point counting. Sixty-four root surfaces were investigated
from coronal to apical. The observed tissue changes were similar in groups with
and without bacteria, except for an elevated volumetric density of inflammatory
cells in the first group. The attachment was lost apically. Principal fibers
running to the root surface and extensions in the cementum decreased from coronal
to apical, but were replaced by fibers running parallel to cementum and fibers
oriented in a network. We suggest that acellular extrinsic fiber cementum was
lost, whereas cellular mixed stratified cementum was built. The cellular mixed
stratified cementum synthesis was by inclusion of the remaining fibers from the
acellular extrinsic fiber cementum. We suspect that the changes were the result
of the anti-inflammatory reaction caused by the periapical lesion.
PMID- 10687514
TI - Bactericidal effects of 2.94 microns Er:YAG-laser radiation in dental root
canals.
AB - The purpose of this study was to investigate the antimicrobial properties of
Er:YAG-laser radiation in dental root canals. The root canals of 90 freshly
extracted anterior teeth were enlarged mechanically, sterilized, and randomly
divided into subgroups of 10 samples. The root canals were inoculated with
Escherichia coli or Staphylococcus aureus for 2 h. The laser treatment groups
were exposed for either 15 or 60 s to Er:YAG-laser radiation (pulse energy: 50
mJ; 15 pps). Additionally, for each bacterial strain, one sample group was rinsed
with a NaOCl solution (1.25%), and one was left untreated as control. After
irradiation or irrigation, the number of bacteria was evaluated using the surface
spread plate technique. In the case of S. aureus, the primary bacterial load
(control group) of the root canals was reduced to 0.15% after 15 s and 0.06%
after 60 s of laser treatment. In the E. coli group, the number of bacteria was
diminished to 0.13%, with the shorter radiation time and to 0.034% after 60 s of
radiation. Irrigating the root canals with NaOCl, a reduction of the number of
bacteria to 0.033% for S. aureus and to 0.020% for E. coli could be obtained. As
the results confirm, Er:YAG-laser radiation exerts very effective antimicrobial
properties in dental root canals, depending on the time of radiation.
PMID- 10687515
TI - Wear of nickel-titanium lightspeed instruments evaluated by scanning electron
microscopy.
AB - Used rotary nickel-titanium instruments require frequent replacing. This
laboratory study evaluated defects of Lightspeed cutting tips before and after
usage. The instruments were fixed into custom-made holders, the cutting heads
photographed in a scanning electron microscope at x120 to x400 magnification at
preset points around the cutting tip (90, 180, 270 and 360 degrees) and head-on.
Instrument sizes 20 to 32.5, 35 to 60, and 65 to 100 were used in 9, 18, and 36
canals, respectively, and autoclaved after shaping every third root canal. The
used instruments were cleaned and then reexamined in a scanning electron
microscope as before. The presence of 11 types of conditions was scored from the
pre- and postusage photographs. No instruments fractured during the test, but all
the cutting heads had one or more imperfections, even before usage. The presence
of debris, pitting, and metal strips changed significantly. Imperfections were
found on new and used Lightspeed cutting heads, indicating the general difficulty
in machining defect-free nickel-titanium rotary instruments. However, high
quality should remain a goal to improve instrument efficiency.
PMID- 10687516
TI - Rapid decontamination of gutta-percha cones with sodium hypochlorite.
AB - Gutta-percha cones are now widely used to fill root canals. Because they cannot
be sterilized by conventional autoclaving or in a hot-air oven, gutta-percha
cones require rapid chairside decontamination before use to maintain the aseptic
chain, an essential factor in successful endodontic therapy. The purpose of this
study was to compare the effectiveness of different concentrations of sodium
hypochlorite (0.25% to 4%) in sterilizing gutta-percha cones artificially
contaminated with Staphylococcus aureus and Escherichia coli strains, and
Bacillus subtilis spores. After 1 min of treatment, the solutions tested showed
bactericidal and sporicidal effects at concentrations of 0.25% and 1%,
respectively. At a concentration of 0.25%, the solutions tested were effective in
destroying spores after 5 min of exposure. Based on this study, treatment of the
cones for 1 min with 1% sodium hypochlorite (Milton's solution) or for 5 min with
Dakin's liquid (0.5% sodium hypochlorite) is recommended.
PMID- 10687517
TI - Residual thickness of root in first maxillary premolars with post space
preparation.
AB - It has been suggested that, to ensure tooth strength, a minimum of 1 mm of root
wall thickness should be left after post preparations. The purpose of this study
was to determine the instrument diameter that will not affect this measurement in
maxillary first premolars. Post preparations were made in 106 teeth with one and
two root canals at a working depth equal to the anatomical crown length, with
0.70, 0.90, 1.10, 1.30, 1.50, and 1.70 mm diameter instruments. Sections were cut
perpendicular to the long axis of the tooth at the cervical and apical ends of
each preparation, and the minimum width of residual root was measured on each
wall, at both sites. A binocular microscope with a micrometer eyepiece was used.
At the cervical level of the preparation, no group showed a wall thickness < 1
mm. Data for the apical sections was statistically analyzed, and the
corresponding confidence limits were calculated with 95% confidence on the mean.
The results show that the minimum residual thickness was only preserved when 0.70
mm instruments were used in single-canal roots and when 1.10 mm or smaller
instruments were used for two-canal roots. This seemingly anomalous result occurs
because fluting on both the mesial and distal sides of the root impinge on single
canals, whereas dual canals are buccally or lingually displaced to an area of
thicker root diameter.
PMID- 10687518
TI - An evaluation of endodontically treated vertically fractured teeth.
AB - For this survey, 92 vertically fractured endodontically treated teeth were
evaluated clinically and radiographically before and after extraction. The
maxillary second premolars (27.2%) and mesial roots of the mandibular molars
(24%) were the most fractured teeth. In 67.4% of the teeth, a solitary buccal
pocket was present; in 34.8%, a fistula frequently appeared closer to the
gingival margin than to the apical area. A lateral radiolucency or a combination
of lateral and periapical radiolucency was found in more than half of the cases.
The general practitioners correctly diagnosed vertical root fracture in only one
third of the 92 fractured teeth in this survey.
PMID- 10687519
TI - Surgical extrusion of a cervically root-fractured tooth after apexification
treatment.
AB - A case is reported in which an incisor fractured below the alveolar crest 6
months after completion of apexification treatment was surgically extruded for
prosthetic coronal restoration. After the surgical procedure, a dowel post was
placed in the root canal, a core was built using glass-ionomer cement, and a
porcelain veneer crown restoration was completed. The 24-month follow-up
examination after surgical, endodontic, and prosthetic treatments showed that the
tooth was clinically and radiographically healthy and functioned well.
PMID- 10687520
TI - Histological and densitometric analysis of the effects of exogeneous heparin on
rat pulp tissues.
AB - In this study, the effects of heparin on dentinal resorption was investigated in
rats. Animals were injected with 2 x 2 IU/g Na-Heparin subcutaneously for 33
days. Histopathological examination of the anterior teeth revealed capillary
proliferation, congestion, and fibrosis in the pulp in addition to resorptive
lacunae and degenerative bone spiculae in the peripheral bone tissue. Development
of fibrosis in the pulp tissue was verified by densitometric analysis, which
revealed a 30% increases in mean density after heparin administration. No
resorption at all, however, was seen in dentin.
PMID- 10687521
TI - An evaluation of antimicrobial efficiency of Endo-Fill root canal sealant and
filling material.
AB - The antimicrobial efficiency of Endo-Fill root canal sealant and filling material
was microbiologically evaluated. The zones of inhibition around the Endo-Fill by
agar diffusion method were measured. Staphylococcus aureus, Streptococcus
faecalis, Streptococcus pyogenes, Escherichia coli, Candiada albicans, and
Pseudomonas aeruginosa were used as the selected microorganisms. No zone of
inhibition was seen around the Endo-Fill in any of the examples.
PMID- 10687522
TI - Bacterial microleakage of Cavit, IRM, TERM, and Fermit: a 21-day in vitro study.
AB - The aim of our study was to evaluate the leakage of four cements (Cavit, IRM,
TERM, and Fermit) using a two-compartment model system and Streptococcus sanguis
as bacterial marker. Access cavities in premolars were filled with cement and the
teeth immersed in culture medium in the model system. Half of the teeth were
thermocycled on day 2. Bacterial percolation into the upper compartment was
measured at regular intervals (days 2, 7, 14, and 21). Cement thickness was
measured at the end of the study. In the nonthermocycled group, Cavit was more
leakproof than the other cements at day 2 (p = 0.011), than TERM and IRM at day 7
(p = 0.043). Fermit was more leakproof than IRM at day 7 (p = 0.043). In the
thermocycled group, Cavit was more leakproof than the other cements at day 7 (p =
0.041). Thermocycling did not significantly affect leakage. Cement thickness
averaged 4.1 mm and did not significantly affect leakage. These results should be
considered when using cements as temporary fillings.
PMID- 10687523
TI - Evaluation of the combination of flurbiprofen and tramadol for management of
endodontic pain.
AB - Effective management of endodontic pain represents a continuing challenge. In
this study, we evaluated the efficacy of flurbiprofen and a novel centrally
acting analgesic, tramadol, alone and in combination, for reducing pain in
endodontic emergency patients. Patients (n = 49) were administered a local
anesthetic and underwent pulpectomy. They were then administered, on a double
blind basis, either: (i) placebo (one capsule to start and then every 6 h); (ii)
flurbiprofen (100 mg loading dose and then 50 mg every 6 h); (iii) tramadol (100
mg loading dose and then 100 mg every 6 h); or (iv) the combination of
flurbiprofen and tramadol (as above). Pulpectomy combined with placebo medication
resulted in a 50% reduction in pain by 24 h (p < 0.01). Patients treated with
flurbiprofen and tramadol reported less pain, compared with placebo treatment at
6 and 24 h (p < 0.01 for both). These results suggest that a nonsteroidal anti
inflammatory drug/opiate combination, together with endodontic therapy, may be
useful in the management of endodontic pain.
PMID- 10687524
TI - Endothelial cell adhesion molecules in human dental pulp: a comparative
immunohistochemical study on chronic periodontitis.
AB - Migration of leukocytes to inflammation sites through vascular endothelium is
controlled by the interactions of adhesion molecules expressed on both
endothelial cells and leukocytes, most of which are already covered by cluster of
differentiation (CD) codes. We examined the expression of a variety of
endothelial cell adhesion molecules in human dental pulp vasculature to obtain
further evidence on the tissue distribution and function of these molecules by
using an indirect immunoperoxidase technique. We obtained the pulp tissue samples
from teeth extracted due to orthodontic reasons as controls and compared with
those extracted due to chronic periodontitis. In all samples, both CD31 and CD146
were expressed by arterial, venous, and capillary endothelia. There was no
significant difference between the staining intensity of normal and inflamed pulp
tissues. CD102 expression on the endothelium was significantly stronger in
chronic periodontitis pulp samples. CD106, CD62-E, CD62-P, CD105, and CD54 were
variably expressed in control and chronic periodontitis groups. Our results
indicate that CD102 represents the major endothelial cell adhesion molecule
probably involved in the inflammatory reactions in chronic periodontitis.
PMID- 10687525
TI - Root deformation during root-end preparation.
AB - Ultrasonic root-end preparation techniques have recently been introduced and
revolutionized the field of endodontic surgery. However, several reports claimed
that there was an increasing incidence of crack formation after ultrasonic root
end preparation. As yet, little work has focused on the root deformation during
root-end preparation. Thus, the purpose of this investigation was to measure the
amount of root deformation during root-end preparation with the use of
microhandpiece and ultrasonic systems by using strain gauge methods, and
simultaneously to detect any cracks with the aid of the stereomicroscope, stain,
and an image processing system. The results demonstrated the ultrasonic
instrumentation produced significantly greater strain on average than that
generated with the microhandpiece system. From the viewpoint of fracture, any
technique that could diminish the strain on the root would decrease the
likelihood of fracture; however, no crack was observed on any resected surface of
roots in this study.
PMID- 10687526
TI - Evaluation of diamond-coated ultrasonic instruments for root-end preparation.
AB - Ultrasonic instrumentation has been associated with cracking of the dentin in the
area of the root-end preparation. The purpose of this study was to evaluate root
end preparations for cracking and to describe cavosurface morphology after the
use of diamond-coated instruments. Forty teeth were inspected for intradentin
cracks, incomplete canal cracks, and complete canal cracks before and after
preparation with a stainless steel CT-5 ultrasonic instrument and again after
root-end preparation with an S12D/90 degrees diamond-coated instrument. Six teeth
had polyvinylsiloxane impressions taken of the root ends after preparation with
the CT-5 and again after preparation with the diamond-coated instrument. Replicas
were made, split, sputter-coated, and inspected using the scanning electron
microscope. This study indicates that use of the diamond-coated instrument for
root-end preparation does not result in significant root-end cracking and that it
can remove cracks created by a prior instrument's use. The use of the diamond
coated instrument resulted in a heavily abraded, debris-covered cavosurface that
may affect the apical seal.
PMID- 10687527
TI - Biocompatibility of an adhesive system applied to exposed human dental pulp.
AB - Human pulp tissue was directly capped with All Bond 2, or calcium hydroxide and
evaluated 7, 30, or 60 days after the procedures. Histological analysis was
performed to assess the inflammatory cell response, tissue disorganization,
dentin bridging, and the presence of bacteria. At 7 days, with All Bond 2
capping, there was a large area of neutrophilic infiltrate underlying the pulp
capping material, and the death of adjacent odontoblasts, was observed. However,
with time, the neutrophilic reaction was replaced by fibroblastic proliferation
with macrophages and giant cells surrounding globules of resin scattered in the
coronal pulp tissue. The persistent inflammatory reaction and hyaline alteration
of extracellular matrix inhibited complete pulp repair or dentin bridging. In
contrast, at 7 days, the pulp tissue capped with calcium hydroxide exhibited
odontoblast-like cells organized underneath coagulation necrosis. Pulp repair
evolved into apparent complete dentin bridge formation at 60 days. All Bond 2 did
not appear to allow any pulp repair and does not appear to be indicated for
direct pulp capping of human teeth.
PMID- 10687528
TI - Effect of retinoic acid on osteopontin expression in rat clonal dental pulp
cells.
AB - We studied the effect of retinoic acid on osteopontin synthesis and the mRNA
expression in rat clonal dental pulp cells, RPC-C2A. An immunoprecipitation assay
clarified that retinoic acid caused an increase in phosphorylated osteopontin
synthesis that was dose-dependent, and marked increases were observed at retinoic
acid concentrations of 10(-6) to 10(-5) M (1.7-fold). A Northern blotting
analysis revealed a similar pattern of increase in osteopontin mRNA expression of
up to 6.2-fold of control levels. Because osteopontin has an important role in
the mineralization process, these results suggest that retinoic acid regulates
mineralization, which takes place in the pulp cavity, including reparative dentin
formation.
PMID- 10687529
TI - Clinical undergraduate teaching.
AB - At the present time, most endodontists who teach in the undergraduate dental
school clinics do not receive formal training. Dental schools have traditionally
assumed that the expert knowledge and technical skills that these endodontists
could contribute would be sufficient to allow them to teach successfully. Today,
we know that this is not always the case. To improve the instructional function
of the dental clinics, instructors should recognize and assume their
responsibilities as tone-setters, facilitators, and role models. They should
define their goals and objectives clearly, and strive to create an open and
trusting learning environment for their students. Instructors must also recognize
the significance of their impact on the development of their students. Formal
pedagogical training would assist instructors in fulfilling these
responsibilities.
PMID- 10687530
TI - Apical canal diameter in the first upper molar at various ages.
AB - The shape of root canals cross-sectioned through their roots at 2 mm from their
apices and its correlation with the D0 diameter of endodontic instruments was
evaluated in 40 first upper molars. The molars were grouped according to age:
under 13 yr (children), 18 to 20 yr (adolescents), 30 to 40 yr (adults), and over
50 yr. Evaluation of the root canal diameters revealed that the shapes were
predominantly circular in the palatal canal, mostly flat in the mesiobuccal
canal, and circular or flat in equal proportions in the distobuccal root. Age
does not seem to affect the shape of the canals. Narrowing with age was
statistically significant (p < 0.05) for palatal and mesiobuccal canals only.
Correlation between the maximum diameter of the canals and the instruments was
varied. Even in old age, diameters were observed that would require instruments
of a size that would be impossible to use, because one internal diameter would
exceed the root's external diameter in a different direction (i.e. intimal
buccolingual diameter of #80 and external mesiodistal diameter of #70).
PMID- 10687531
TI - Effect of the type carrier used on the results of dichlorodifluoromethane
application to teeth.
AB - Thermal testing, especially cold, is an important part of diagnosing pulpal
vitality. It was the purpose of this study to determine (i) if a difference
exists in temperature when Endo ice is used with four different applicators, and
(ii) if there is one applicator device that provides the greatest thermal change
for a tooth. Endo ice was used with the following applicators: a #2 standard size
large cotton pellet, a #4 standard size small cotton pellet, a wood stick cotton
tip applicator, and a cotton roll. The temperature of a mandibular incisor pulp
chamber was measured in degree C 10 s after the application of the
dichlorodifluoromethane (DDM) to the midfacial surface of the crown. Also, the
DDM was applied to each applicator either by direct spray or by submergence in
DDM liquid. This study found that the greatest temperature change was recorded by
Endo Ice (DDM) sprayed directly onto a large cotton pellet. There was no
significant difference between directly spraying or submerging the applicator in
DDM liquid.
PMID- 10687532
TI - A four-rooted quadrangular maxillary molar.
AB - The endodontic treatment of a maxillary molar with an aberrant root morphology
can be diagnostically and technically challenging. This case report is presented
to illustrate and describe the endodontic treatment of a four-rooted maxillary
molar with a quadrangular root trunk morphology.
PMID- 10687533
TI - Evaluation of pigmented intraorifice barriers in endodontically treated teeth.
AB - The purpose of this study was to evaluate the effectiveness of three pigmented
glass ionomer cements used as intraorifice barriers to prevent coronal
microleakage. One hundred ten extracted mandibular human premolars were divided
into four experimental groups of 25 teeth each and two control groups of 5 teeth
each. The experimental teeth were instrumented and obturated using
thermoplasticized gutta-percha and AH26 sealer. Group 1 teeth received no further
treatment. Teeth in groups 2 through 4 had 1 of 3 pigmented glass ionomers
(Vitrebond, GC America, and Ketac-Bond) placed as an intraorifice barrier.
Positive control teeth were instrumented but not obturated. The negative control
teeth were instrumented, obturated, and externally sealed with epoxy resin. The
coronal 3 mm of each root was sealed into the lumen of an 18-mm segment of latex
surgical tubing. After the apparatus was sterilized, 2.0 ml of a 24 h growth of
Proteus vulgaris in trypticase soy broth (TSB) was placed in the coronal
reservoir of the tooth. The inoculated apparatus was placed into a presterilized
test tube containing 1.5 ml of TSB and incubated for 90 days at 37 degrees C. The
TSB in the lower reservoir was observed daily for turbidity, which would indicate
leakage along the full length of the obturated root canal. To determine if
differences in microbial leakage occurred among the four experimental groups,
Pearson's chi 2 and Fisher's exact tests were performed. The confidence level was
set at 95%. The positive and negative controls validated the microbial testing
method. The teeth without an intraorifice barrier leaked significantly more than
teeth with Vitrebond intraorifice barriers (p < 0.05). The difference in leakage
among the experimental glass ionomer barriers was not significant (p > 0.05).
PMID- 10687534
TI - Changes in root surface temperatures with in vitro use of the system B
HeatSource.
AB - The purpose of this study was to measure root surface temperatures while using
the System B HeatSource at various temperature settings. A split-tooth model of a
human maxillary central incisor was prepared with 10 thermocouples to record root
surface temperatures at 1-mm increments from the root apex. A System B HeatSource
model 1005 was used to warm and compact gutta-percha to within 3 mm of the
working length using the Buchanan technique. Twenty obturations were recorded at
each of the following temperature settings: 250 degrees, 300 degrees, 350
degrees, 400 degrees, 450 degrees, 500 degrees, 550 degrees, and 600 degrees C.
Examination of the mean temperatures recorded for each position and at each
temperature setting revealed that the thermocouple 5 mm from the apex (T5)
detected the highest increases in root surface temperatures. Only this site
exceeded the 10 degrees C rise in temperature for one full minute that could
cause damage to the supporting structures. The range of instantaneous
temperatures at this site was 8.85 to 12.06 degrees C, with a mean of 10.62 +/-
0.93 degrees C. The results of this in vitro study indicate that any temperature
setting of the System B HeatSource at or above 250 degrees C has the potential to
cause the root surface temperature to rise 10 degrees C. Whether this occurs in
vivo or if it does is maintained long enough to cause any tissue damage remains
to be determined.
PMID- 10687535
TI - Rapid determination of dry weight in human dental pulp by a colorimetric
reaction.
AB - This study was designed to assess total carbohydrate (TC) concentration, as well
as the noncollagenous protein content, in human dental pulp. Pulps were obtained
from eight premolars (13.10 +/- 4.33 mg weight, mean +/- SD) and homogenized in
saline solution. TC content was as follows: 16.68 +/- 9.49 micrograms/mg of
tissue (mean +/- SD); 3.22 +/- 1.69 ng of TC/mg protein (mean +/- SD); and 16.23
+/- 6.80 micrograms of TC/mg total organic material (mean +/- SD). The high
concentration of carbohydrates observed in the pulp is a result of the presence
of glycoproteins, glycosaminoglycans (chondroitin-6-sulfate, heparan sulfate,
hyaluronic acid, and dermatan sulfate), and proteoglycans, whose structural,
biochemical, and physiological functions have been well documented. Dry weight
determination using dichromate solution was used because it shows less dispersion
than when the data on carbohydrates and proteins are expressed as wet weight.
PMID- 10687536
TI - An improved technique for the evaluation of root canal preparation.
AB - A device and a method are described for the simultaneous in vitro evaluation of
several important parameters of root canal preparation, including root canal
cleanliness, straightening, changes in root canal diameter, working safety (loss
of working length, apical blockage, instrument fracture, and apical perforation),
measurement of apically extruded debris, working time, and practicability. Using
a modification of the muffle system described by Bramante et al. (J. Endodon,
13:243-5, 1987), all of these parameters can be investigated simultaneously
during preparation of two mesial root canals in extracted mandibular molars.
PMID- 10687537
TI - A comparative study of apical leakage of Apexit, Ketac-Endo, and Diaket root
canal sealers.
AB - The purpose of this study was to compare the apical leakage of Ketac-Endo,
Apexit, and Diaket. Fifty freshly extracted human maxillary anterior teeth were
used. The anatomical crowns were removed at the amelocemental junction, and step
back preparation of the roots canals was performed with K-type files to size 40
using 2 ml of 5.25% NaOCl irrigant after each file change. The roots were
randomly divided into five groups of 10 roots each: three experimental and two
control groups. The experimental groups were as follows: group 1, Apexit; group
2, Ketac-Endo; and group 3, Diaket. Root canals were filled with one of the
sealers and gutta-percha using lateral condensation. After the specimens were
stored in 100% humidity at 37 degrees C for 2 wk, the roots were covered with two
layers of nail polish and immersed in 2% methylene blue for 7 days. Each tooth
was split into two sections, and dye penetration was evaluated independently by
three examiners using a stereomicroscope at x20 magnification. Mann-Whitney U
analysis showed that there was no significant difference between Apexit and
Diaket (p > 0.05). However, there was significantly more leakage with Ketac-Endo
(p < 0.05).
PMID- 10687538
TI - Evaluation of microbial infiltration in restored cavities--an alternative method.
AB - This work evaluated the efficacy of an improved method used to determine the
frequency of bacterial infiltration and bacterial population levels and
morphotypes in cavities restored with adhesive composites in conventional mice.
By using the alternative methodology suggested in this work, bacteria from
microleakage were recovered and identified in cavities subjected to restoration
procedures that used acid etching of the dentin and dentin adhesives used with
light-curing resin. The methodology presented herein seems to be more effective
than the one normally used to investigate the presence of bacteria, which uses
acid demineralization of dental structures for the histological processing of
tissues. The results suggest that the methodology presented in this work made it
possible to recover and identify Gram-negative and Gram-positive bacteria from
microleakage. Frequencies of microleakage and bacterial population levels in
restored cavities using two different adhesive systems were not statistically
different (p < 0.05).
PMID- 10687539
TI - Evaluation of apical seal in straight canals after obturation using the
Lightspeed sectional method.
AB - This study evaluated the sectional gutta-percha obturation technique advocated by
Lightspeed Technology, Inc. Single relatively straight-canaled teeth were
prepared with rotary instruments and divided into three groups. Groups A and B
served as controls and were obturated using laterally condensed gutta-percha and
either Roth's 801 or Ketac-Endo sealer. Group C was obturated using the
Lightspeed technique that included placement of a 5-mm apical section of gutta
percha, followed by backfill with Ketac-Endo sealer and a single gutta-percha
cone. All teeth were suspended in India ink for 14 days then cleared. Four
additional teeth, which were obturated as in group C then sectioned, revealed a
tightly adapted apical section of gutta-percha with a very thin layer of sealer.
However, voids were noted in the middle and coronal areas. There was no
significant difference in apical microleakage among the three groups. The
sectional method was significantly faster than lateral condensation and seems to
offer promise as an effective obturation method.
PMID- 10687540
TI - Leakage associated with single or multiple increment backfill with the Obtura II
gutta-percha system.
AB - The purpose of this in vitro study was to compare dye leakage between canals
backfilled in a single increment and canals backfilled in multiple increments
using the Obtura II system with two different sealers. Sixty extracted single
canal teeth were decoronated, cleaned, and shaped. After master cone fit and
placement of either Roth 801 or AH26 sealers, the canals were down-packed to 4 mm
from working length. The teeth were then divided into 4 groups of 15: group 1-
Roth 801 sealer with 1 increment of Obtura II back-fill; group 2--Roth 801 sealer
backfilled in 4- to 5-mm increments; group 3--AH26 sealer with 1 increment of
backfill; and group 4--AH26 sealer backfilled in 4- to 5-mm increments. After
sealer set, the teeth were apicected 5 mm from working length. The apices were
discarded. The coronal segments were coated with two layers of fingernail polish,
except for the resected apical end. The teeth were immersed in Pelikan ink for 5
days. The teeth were then decalcified, dehydrated, and rendered transparent in
methylsalicylate. Dye penetration was measured on four surfaces of each root. The
mean measurements of each tooth were averaged for each group. Leakage of group 1
was 6.69; group 2, 5.39; group 3, 5.71; and group 4, 5.02. Differences were not
statistically significant (p > 0.05). This study suggests that it may be
clinically acceptable to backfill canals up to 10 mm in a single increment using
sealer and the Obtura II gutta-percha system.
PMID- 10687541
TI - Comparison of two implantation sites for testing intraosseous biocompatibility.
AB - The purpose of this study was to compare two implantation sites--the mandible and
the femur of the rabbit--for testing in vivo intraosseous biocompatility. Twenty
two new Zealand rabbits were anesthetized, and the mandibular and femur bones
were exposed. A hybrid glass ionomer cement or zinc oxide eugenol cement was
loaded into silicone carriers and inserted into the two bones after drilling the
two cortical plates. Eleven rabbits were killed 4 wk after implantation, and 11
rabbits were killed after 12 wk. The mandibles and femurs were prepared using
standard histological procedures; tissue reactions were graded from none to
severe. At 4 wk, no statistically significant difference was found between the
two implantation sites. After 12 weeks, bone healing was statistically better in
the mandible than in the femur. The mandible seems to be a better implantation
site in the case of intraosseous implantation tests. The intraosseous
biocompatibility of Vitremer was similar at 4 wk and superior at 12 wk to that of
Super-EBA.
PMID- 10687542
TI - Eosinophil-derived transforming growth factors (TGF-alpha and TGF-beta 1) in
human periradicular lesions.
AB - Inflammatory mediators of periradicular lesions are poorly understood.
Transforming growth factors-alpha and -beta 1 (TGF-alpha and TGF-beta 1) have
been linked with the cellular processes for both soft and hard tissue wound
healing. The purpose of this study is to demonstrate the cellular sources of TGF
alpha and TGF-beta 1 mRNA and protein in periapical lesions by in situ
hybridization and immunohistochemistry. Nine periapical granulomas and nine
periapical cysts were examined. TGF-alpha mRNA and protein were not detectable in
the granulomas examined. However, eosinophils surrounding the periapical cysts
demonstrated both TGF-alpha mRNA and protein. The vast majority of eosinophils
present in the periapical granulomas and cysts also demonstrated TGF-beta 1 mRNA
and protein. Other cells producing TGF-beta 1 were lymphocytes, fibroblasts, and
monocytes. The presence of wound repair cytokines, such as TGF-alpha and TGF-beta
1, suggests a mechanism by which the host inflammatory response may participate
in the repair and remodeling of periapical tissues.
PMID- 10687543
TI - Effect of preflaring on Root ZX apex locators.
AB - The Root ZX apex locator is an example of a generation of apex locators that
identify the terminus of the canal by measuring a ratio between two electrical
impedances. Studies have shown this device to have a high degree of accuracy.
However, the manufacturer warns that the performance of these devices is limited
by the presence of calcifications and dentinal shaving obstructions. An in vitro
study was designed to determine if preflaring of canals would facilitate the
passage of files to the apical foramen by eliminating cervical interferences and
to see what effect this would have on the performance of the Root ZX apex
locator. Thirty-two canals were divided into two groups. Group 1 was not
manipulated before use of the Root ZX apex locator and served as control. In
group 2, the canals were preflared before the use of the Root Zx apex locator.
The working length files were secured in place and measured with the linear
measurement tool used by the Visilog 5 imaging program. Results of this study
suggest that preflaring of canals will allow working length files to more
consistently reach the apical foramen (p = 0.015), which in turn increases the
efficacy of the Root ZX apex locator.
PMID- 10687544
TI - Effectiveness of gutta-percha removal with and without the microscope.
AB - The microscope may be useful in retreatment to enhance removal of gutta-percha
(GP) and to identify deficiencies in the original treatment. This study compared
the effectiveness of GP removal with and without a microscope. Forty-five
extracted canines were stepback prepared and obturated with GP and Roth's sealer
using lateral condensation. Teeth were stored for 17 months in a humidor, then
divided into four groups: group 1 (n = 20)--GP removal without aid of the
microscope (group 1 criteria for GP removal was lack of GP on final files and on
paper points agitated within the chloroform-filled canal); group 2 (n = 20)--GP
removal with the microscope. (In addition to group 1 criteria, canals were
inspected with the microscope; additional GP was removed when identified. In both
groups, GP was removed using a combination of mechanical instrumentation,
chloroform solvent, and K-files); group 3 (n = 3)--positive control, canals
remained obturated; and group 4 (n = 2)--negative control, canals were neither
prepared nor obturated. Teeth were split longitudinally, photographed, then
divided into thirds to compare the apical, middle, and cervical thirds. Remnants
of GP and sealer on the canal wall were traced with a digitizer, and the
remaining mean % GP was analyzed by t test. Group 1 had 8.3% remaining GP, and
group 2 had 7.3% remaining GP. There was no significant difference demonstrated
between the two experimental groups.
PMID- 10687545
TI - Dental blood supply in the segmentally resected mandible.
AB - There are approximately 30,000 new cases of oral and pharyngeal carcinoma treated
in the United States each year. A large number of these patients go on to receive
segmental resection of the mandible, and have natural teeth remaining on the
surgical side. To the best of our knowledge, there has not been a thorough
discussion of the blood supply to these remaining teeth. Radiographic evidence of
periapical pathology in these teeth is unusual, despite the compromised vascular
supply. The purpose of this article is to report a case and review the literature
on blood supply to teeth after segmental mandibulectomy. Microscopic examination
was conducted on the pulpal tissue of a premolar retained on the side of, and
anterior to, a segmental mandibular resection. Although abnormal, the pulp tissue
showed evidence of a vascular supply 4 yr after mandibular surgery. A literature
review was performed, and a discussion is given to explain the continued
vascularity of the dentition through collateral and retrograde circulation.
Despite the compromised dental circulation on the surgical side, unless
radiographic evidence of periapical pathology occurs, endodontic therapy or
extraction is not necessary. Due to the compromised nature of the circulation
however, these teeth may be more susceptible to caries or restorative dental
procedures that may lead to pulpal necrosis.
PMID- 10687546
TI - A new approach for the retrieval of broken instruments.
AB - The purpose of this article is to present a modified ultrasonic spreader and a
new technique that are used for the retrieval of solid obstructions that can not
be bypassed by conventional methods. The technique advocated and the instruments
proposed are described. A clinical case is discussed to show the possibilities
and limitations of both instrument and method.
PMID- 10687547
TI - Zebra. XVII. Part 2: The case of the elusive gutta-percha.
PMID- 10687548
TI - Adaptive skin blood flow increases during hip-down lying in elderly women.
AB - OBJECTIVE: Pressure ulcer development due to unrelieved pressure during extended
cardiovascular, orthopedic, and other procedures is an important clinical
problem. Because blood flow changes within pressure-loaded tissue affect the skin
breakdown process, the relative effects of 2 support surface strategies on
trochanter skin blood flow were investigated. DESIGN: Skin blood perfusion was
assessed by laser Doppler methods during 1 hour of continuous loading. Blood
perfusion was measured before and during hip-down loading on a gel pad (static
surface) and a dynamic multisegmental surface that provided periodic alternating
pressure relief. Female volunteers (N = 20, age > or = 60 years) were tested on
each surface in random order with sequential tests separated by 5 to 8 days.
Effects were assessed by comparing perfusion during the first and last 15 minutes
of hip-down loading with a 15-minute baseline. SETTING: Research center. RESULTS:
Pre-load perfusions (dynamic vs static support) were similar (0.57 +/- 0.06 vs
0.64 +/- 0.08). During loading, however, a significant progressive increase in
perfusion was noted only with dynamic support; by the end of the loading
interval, this increase in perfusion had significantly exceeded the pre-load
baseline (1.22 +/- 0.26, P = 0.001). CONCLUSION: These findings reveal a surface
dependent blood flow impact, with the multisegmental dynamic approach being
associated with greater flow during loading. The mechanism, though speculative,
is consistent with a greater vascular adaptation potential offered by the dynamic
surface. Conditions that facilitate such adaptive flow increases would appear to
be of considerable benefit in helping to prevent ulcer development.
PMID- 10687549
TI - Why wound care testing?
PMID- 10687550
TI - The national examination blueprint: information and practice questions.
PMID- 10687552
TI - Prophylactic foot surgery in the diabetic patient.
AB - The preoperative and perioperative evaluation of diabetic foot pathologies has
been discussed. The effects of vascular and neuropathic alterations in such cases
can be devastating. Only through understanding of the underlying mechanisms that
contribute to the diabetic foot can progressive, appropriate care be rendered.
PMID- 10687551
TI - History of the American Academy of Wound Management.
PMID- 10687553
TI - The role of biotechnology in the global economy.
PMID- 10687555
TI - Consensus development conference on diabetic foot wound care. 7-8 April 1999,
Boston, MA. American Diabetes Association
PMID- 10687554
TI - Pressure ulcers in community-based older adults receiving home health care.
Prevalence, incidence, and associated risk factors.
AB - OBJECTIVES: To determine the prevalence and incidence of pressure ulcers in
community-based adults receiving home health care and to identify risk factors
for incident Stage II to IV pressure ulcers. DESIGN: Retrospective cohort study.
SETTING: A large midwestern urban home health care agency. PATIENTS: The study
cohort was 1711 nonhospice, nonintravenous therapy subjects admitted between
January 1995 and March 1996 who were > or = age 60 and pressure ulcer-free on
admission. MEASUREMENTS: Data on risk factors were extracted from admission
information. Patient records were followed forward chronologically to the
outcomes: pressure ulcer development or no pressure ulcer. MAIN RESULTS: The
incidence of Stage II to IV pressure ulcers was 3.2%. Cox regression analyses
revealed that limitation in activity to a wheelchair, needing assistance with the
activities of daily living--dressing, bowel and/or bladder incontinence, a Braden
Scale mobility subscore of very limited, anemia, adult child as primary
caregiver, male gender, a recent fracture, oxygen use, and skin drainage
predicted pressure ulcer development (P < or = 0.05) in this exploratory model.
CONCLUSIONS: Patients > or = age 60 who are admitted to a home health care agency
with 1 or more of these risk factors require close monitoring for pressure ulcer
development and should be taught preventive interventions on admission.
PMID- 10687556
TI - Complementary and alternative medicine in wound healing.
PMID- 10687557
TI - Off-loading techniques in the treatment of diabetic plantar neuropathic foot
ulceration.
AB - In the individual with diabetes mellitus, foot ulceration represents the single
most important risk factor in lower-extremity amputation. The goal of treatment
is to obtain a healed and closed wound that (1) eliminates a portal of entry for
bacterial invasion and development of limb-threatening infection, and (2) allows
for tissue loading. This manuscript reviews current off-loading approaches to the
treatment of plantar neuropathic foot ulcers, along with advantages and
disadvantages of those techniques.
PMID- 10687558
TI - Report on the prevalence of skin ulcers in a home health agency population.
AB - OBJECTIVE: This survey was conducted to assess the presence of skin ulcers within
a home health agency population in the United States. DESIGN: This voluntary
survey was conducted by 177 home health agencies. A single observation of each
patient within the agency's active caseload formed the cohort examined. Patients
deemed to be at low risk (Braden Scale score > 19) were eliminated from further
evaluation, while those with skin ulcers were evaluated for wound- and caregiver
related factors. Surveys were conducted between March 1, 1996, and December 31,
1997. SETTING: Home health agencies in 19 states throughout the United States,
with no restrictions on the type or acuity of the patients served. RESULTS: A
total of 21,529 patients were surveyed, with a prevalence of pressure ulcers
(inclusive of all stages) of 6.8% (n = 1455). Rates for each agency ranged
between 0.5% and 35.7%. The total number of ulcers reported was 2526 (average per
patient was 1.7), with 36% (n = 919) found on the sacrum and the buttocks.
CONCLUSION: Pressure ulcers were the most frequently reported reason for
admission to the agency's caseload. Survey results are similar to rates reported
in other segments of the health care industry. However, among the home health
care population, the primary caregiver is unlikely to be a health care
professional. This survey found that the patient's spouse was the primary
caregiver in 30% (n = 437) of the 1450 responses received regarding the
relationship of the primary caregiver to the patient.
PMID- 10687559
TI - Assessment and diagnosis of burn wounds.
PMID- 10687560
TI - The APTA electrical stimulation lawsuit and its aftermath. American Physical
Therapy Association.
PMID- 10687561
TI - Misunderstood illnesses: fibromyalgia and chronic fatigue syndrome.
PMID- 10687562
TI - Perspective: why I volunteer.
PMID- 10687563
TI - Nurses as a scarce resource.
PMID- 10687564
TI - Health Professions Act--what are the gains for the nursing profession?
PMID- 10687565
TI - Job action and the code of ethics.
PMID- 10687566
TI - Remembering contributions of nurses during WWII.
PMID- 10687567
TI - Standards for registered nurses. Alternate and complementary therapy in nursing
practise.
PMID- 10687568
TI - Whither cesareans in the new millenium?
PMID- 10687569
TI - Knee-chest postural management for breech at term: a randomized controlled trial.
AB - BACKGROUND: In 3 to 4 percent of all term births, the fetus presents as a breech.
The objectives of this trial were to assess if assuming the knee-chest position
reduced the frequency of breech presentation at delivery, increased the success
of the subsequent external cephalic version, or both, and to determine if this
management plan reduced the need for cesarean delivery. METHODS: A randomized
clinical trial recruited 100 women from two hospitals in Adelaide, South
Australia, with a singleton breech presentation and a gestational age equal to or
more than 36 weeks. Women in the treatment group were advised to assume the knee
chest position for 15 minutes three times a day for one week. Women in the
control group did not perform postural management. All participants were reviewed
one week later, and women whose baby remained as a breech presentation were
offered an external cephalic version. RESULTS: Postural management did not
increase the success of the external cephalic version, reduce the frequency of
breech presentation at delivery, or reduce the need for cesarean delivery in
women with a breech presentation at term. CONCLUSIONS: Findings from this trial
included in a meta-analysis of postural management for breech presentation at
term suggested that this is not an effective form of care to be offered routinely
to women with a breech presentation at term.
PMID- 10687570
TI - Smoking relapse and early weaning among postpartum women: is there an
association?
AB - BACKGROUND: Smoking in the postpartum period may contribute to early weaning,
although the nature and temporal aspect of the relationship are poorly
understood. The objective of this study was to examine the association between
early weaning and smoking relapse among women who stopped smoking during
pregnancy. METHODS: A secondary analysis of data from a randomized controlled
trial was conducted. The participants were 228 women who had stopped smoking for
pregnancy, who participated in a smoking relapse prevention trial, and who
breastfed. Women who relapsed to daily smoking postpartum were compared with
those who remained abstinent or smoked occasionally. The dependent variable was
breastfeeding for less than 26 weeks (early weaning). Potential covariates
included intended duration of breastfeeding, parity, partner's smoking, nicotine
dependence, emotional health, return to paid employment, and various
sociodemographic variables. RESULTS: Approximately two-thirds (65.1%) of the
women who relapsed to daily smoking weaned before 26 weeks compared with 33.8
percent of the women who remained abstinent or smoked occasionally. Controlling
for intended duration of breastfeeding, education, and return to paid employment,
women who resumed daily smoking were almost four times more likely to wean early
than those who abstained or smoked occasionally. CONCLUSIONS: Early weaning may
result from psychological or physiological changes associated with tobacco use.
Smoking relapse prevention in the postpartum period may be one of the most
effective interventions in ensuring that women who stop smoking for pregnancy
remain stopped and breastfeed their babies for the recommended duration.
PMID- 10687571
TI - Effect of labor analgesia on breastfeeding success.
AB - BACKGROUND: The effect of labor analgesia on breastfeeding success is not well
defined. Some authors have hypothesized that labor analgesia may affect lactation
success. The purpose of this observational study was to determine if intrapartum
analgesia influenced breastfeeding success at 6 weeks postpartum in a setting
that strongly supported breastfeeding. METHODS: Healthy women with uncomplicated
term pregnancies who planned to breastfeed consented to a telephone interview. We
recorded demographic data, labor induction status, delivery mode, and analgesic
medications. At between 6 and 8 weeks postpartum, patients were asked to describe
breastfeeding use, problems encountered, solutions derived, sources of support
and information, and satisfaction. We created a logistic regression model using
intrapartum analgesia information and controlling for demographic factors
previously correlated with lactation success. RESULTS: We enrolled 189 women,
contacted 177 women postpartum, and obtained complete data on 171 women. Of
these, 59 percent received epidural analgesia, 72 percent breastfed fully, and 20
percent breastfed partially (> 50% of infant nutrition) at 6 weeks postpartum.
After controlling for demographics and labor outcome, we could not demonstrate a
correlation between breastfeeding success at 6 to 8 weeks and labor analgesia.
CONCLUSIONS: In a hospital that strongly promotes breastfeeding, epidural labor
analgesia with local anesthetics and opioids does not impede breastfeeding
success. We recommend that hospitals that find decreased lactation success in
parturients receiving epidural analgesia reexamine their postdelivery care
policies.
PMID- 10687572
TI - Managing labor using partograms with different action lines: a prospective study
of women's views.
AB - BACKGROUND: The precise timing of medical intervention for women in prolonged
labor is the subject of considerable debate. The partogram action line is a tool
to assist practitioners in the correct diagnosis of prolonged labor. Despite its
widespread use, the precise timing of the action line has not been rigorously
studied, and women's views have rarely been sought. The aim of this study was to
assess the effect on maternal satisfaction of managing labor using partograms
with action lines drawn at 2, 3, or 4 hours to the right of the alert line.
METHODS: As part of a large pilot randomized controlled trial, women's views were
explored using a specifically designed questionnaire that was completed by 615
primiparas 2 days after giving birth. The quantifiable data were analyzed by
comparing means using ANOVA followed by the Scheffe test. RESULTS: Women in the 2
hour arm were significantly more satisfied than those in the other two arms (p <
0.001), despite having the most obstetric intervention. CONCLUSIONS: For women in
prolonged labor, obstetric intervention can be an acceptable or even favorable
option. Midwives and obstetricians need to provide labor management that takes
into account the preferences of the women to whom they give care.
PMID- 10687573
TI - Commentary: managing labor: what do women really want?
PMID- 10687574
TI - Women's perceptions of midwifery care: a longitudinal study to shape curriculum
development.
AB - BACKGROUND: Health and education services are increasingly expected to focus on
the consumer. The perceptions of childbearing women should be incorporated into
midwifery curricula, but often they are given minimal attention or not sought for
this purpose. This study was designed to enable the views and experiences of
local women to influence curriculum development in a large university in England.
METHODS: A descriptive, longitudinal, qualitative study was conducted using
semistructured and unstructured interviews with women, and data from their
maternity records. Forty-one pregnant women were recruited and interviewed during
pregnancy, in the early postpartum period in hospital, and in their homes 2 to 3
weeks after the birth. RESULTS: Themes were clustered into three categories: the
characteristics and qualities of the caregivers, the individualized nature of
care, and the clinical competence of the caregivers. Continuity of caregiver was
desired but accepted as probably unrealistic by many. Developing a "special"
trusting relationship with a female midwife was perceived as essential to
promoting a positive childbirth experience. Clinical competence was expected and
largely experienced. Negative feelings related to individual caregivers more than
the type of care given. CONCLUSIONS: Most women had positive experiences, finding
midwives and doctors with good knowledge, interpersonal skills, and abilities.
Examples of poor communication skills and interprofessional conflict indicated a
need to give priority to developing and assessing students' interpersonal skills.
Evidence of interprofessional conflict acted as the catalyst to merge midwifery
with the department of obstetrics in the university to enhance interprofessional
learning.
PMID- 10687575
TI - Severity of nausea and vomiting during pregnancy: what does it predict?
AB - BACKGROUND: Relationships between the severity of nausea and vomiting during
pregnancy and selected demographic (employment status, parity, age, smoking) and
pregnancy outcome (birthweight, gender) variables are described. METHODS: Women
who volunteered for a community-based clinical trial were eligible for inclusion
in this study. On three occasions, 12 hours apart, during early pregnancy using a
continuous measure of nausea, vomiting, and retching, women assessed the amount,
duration, and severity of symptoms as they occurred. After the birth of their
infants, they provided information about the duration of nausea, vomiting, and
retching as well pregnancy outcome information by responding to a mailed
questionnaire. Multivariate methods were used to analyze data. RESULTS: More
severe vomiting in early pregnancy was likely to continue for a longer period of
time and was related to decreased infant birthweight. Gestational age, parity
status, and severity of vomiting were predictors of infant birthweight and
together explained 22 percent of the variance in birthweight. A significant
relationship between fetal gender and severity of nausea and vomiting was not
found. CONCLUSIONS: It may be possible to identify women at risk for third
trimester vomiting and to provide appropriate nutritional support and counseling
so that their risk of having a low-birthweight infant is reduced. A larger sample
would be required to assess the relationship between fetal gender and severity of
nausea, vomiting, and retching.
PMID- 10687576
TI - A comparison of breast stimulation and intravenous oxytocin for the augmentation
of labor.
AB - BACKGROUND: Breast stimulation to augment labor has been used for centuries in
tribal societies and by midwives. In recent years it has been shown to be
effective in ripening the cervix, inducing labor, and as an alternative to
oxytocin for the contraction stress test. This study compared the effectiveness
of breast stimulation with oxytocin infusion in augmenting labor. METHODS: Women
admitted to the labor ward were eligible for the study if they had inadequate
labor with premature rupture of the membranes and met inclusion criteria. They
were assigned to oxytocin augmentation or breast stimulation (manual or pump),
and were switched to oxytocin in the event of method failure. Outcomes included
time to delivery, intervention to delivery, proportion of spontaneous deliveries,
and Apgar scores. One hundred participants were needed in each arm of the study
to demonstrate a 2- to 3-hour difference in delivery time, with a power of 80
percent. RESULTS: Analysis was performed on 79 women, of whom 49 were in the
breast stimulation group and 30 in the oxytocin group. Sixty-five percent of the
participants failed breast stimulation and were switched to oxytocin infusion.
Although augmentation start to delivery was shorter for the oxytocin group (p <
0.001), no differences in total labor time occurred between the groups.
Nulliparas receiving breast stimulation had more spontaneous (relative risk 1.7,
p = 0.04), and fewer instrumental deliveries than those receiving oxytocin
(relative risk 0.2, p = 0.02). No significant differences in adverse fetal
outcomes occurred between the study groups. CONCLUSIONS: The small number of
participants and a variety of problems with the conduct of the study prevented
the formulation of reliable conclusions from the results. However, the study
provided important insights into the feasibility and problems of developing a
high-quality randomized trial of augmentation by breast stimulation.
PMID- 10687577
TI - Breast stimulation to augment labor: history, mystery, and culture.
AB - This paper describes the development of a researchable project, arising from the
clinical observation of a physiologic phenomenon during labor. Augmentation of
labor by breast stimulation has been used in a variety of cultures for centuries.
The process of developing a clinical study of augmentation in the modern
obstetric environment is discussed, with reference to cultural attitudes of
patients and health care workers.
PMID- 10687578
TI - Does walking enhance labor progress?
PMID- 10687579
TI - Measurement of distress. A necessity for all patients.
PMID- 10687580
TI - Woman with lung cancer who continues to smoke.
PMID- 10687581
TI - Age, self-efficacy, and change in patients' adjustment to cancer.
AB - OBJECTIVES: The purpose of this secondary analysis was to investigate cancer
patients' self-care self-efficacy and measures of adjustment over time, as well
as the role of self-care self-efficacy with measures of adjustment. The primary
study was a longitudinal study of cancer patients and family members'
adjustments. MATERIALS AND METHODS: Three hundred seven cancer patients at all
stages of cancer completed study instruments on one occasion; 181 completed the
instruments 4 months later; and 124, 8 months later. Instruments included the
Strategies Used by Patients to Promote Health (SUPPH) to measure self-care self
efficacy, the Functional Assessment of Cancer Treatment (FACT) to measure quality
of life, the Profile of Mood States (POMS) to measure patients' mood
disturbances, and the Symptom Distress Scale (SDS) to measure patients' concerns.
RESULTS: Using analysis of variance, a series of one-way repeated measures used
to investigate changes in cancer patients' self-care self-efficacy and measures
of adjustment revealed significant decreases in patients' self-care self-efficacy
(P = .01) and quality of life (P = .001) over time. Patients' symptoms and mood
disturbances did not significantly change over time. The role of self-care self
efficacy with measures of adjustment was investigated using canonical
correlations. For the predictor variables, subscores for coping and enjoying life
on the SUPPH showed the strongest loadings, 0.83 and 0.94, respectively. On the
dependent variables, the FACT was by far the most important variable, with a
loading of 0.92. CONCLUSIONS: Results demonstrate that without intervention,
cancer patients' measures of self-efficacy and adjustment decrease over time, and
patients' self-efficacy influences their adjustment. Psychosocial interventions
have been designed to increase self-efficacy and to enhance adjustment.
Longitudinal study of efficacy-enhancing interventions is needed.
PMID- 10687582
TI - The effect of Epoetin alfa on quality of life in anemic cancer patients.
AB - OBJECTIVES: The purpose of this paper is to review evidence on the use of Epoetin
alfa in the treatment of anemia associated with cancer treatment through a
discussion of clinical and quality-of-life considerations. MATERIALS AND METHODS:
Cancer patients often experience fatigue, which leads to reduced quality of life.
There are few effective treatments available to manage this potentially
debilitating symptom, which can lead clinicians to become discouraged about
treating fatigue. When cancer-related fatigue is due to anemia, there are viable
treatment options. This paper reviews the current management of anemia in cancer
patients, with an emphasis on the use of recombinant human erythropoietin
(Epoetin alfa). CONCLUSIONS: Anemia can contribute to the reduced quality of life
experienced by cancer patients. Blood transfusion, the traditional method of
treating anemia, is effective and relatively inexpensive, but is associated with
certain risks and is subject to limitations in blood supply. Epoetin alfa therapy
provides healthcare providers with an effective alternative to blood transfusion,
and trial results suggest that this intervention has a positive effect on
patients' quality of life. The optimal starting and stopping points for therapy
have not yet been determined. In practice, many physicians begin treatment when
hemoglobin levels drop below 10 g/dL and stop when they rise above 13 g/dL, with
a 75% dose reduction until completion of chemotherapy if hemoglobin again drops
below 12 g/dL. Nonresponse (< 1 g/dL rise in hemoglobin) is met with dose
increase at 4 weeks and discontinuation after 8 weeks. Controlled studies
comparing anemia management via transfusion to the use of Epoetin alfa have not
been done to date. Therefore, the relative cost-effectiveness of Epoetin alfa, an
effective but expensive intervention, remains unknown.
PMID- 10687583
TI - Healing Icons: art support program for patients with cancer.
AB - OBJECTIVES: The purpose of this report is to describe the structure and process
of an art support program for patients with cancer who are age 16 and older.
MATERIALS AND METHODS: Healing Icons is a six-session art support program for
cancer patients. During the program participants create a three-dimensional mixed
media art piece to convey a unique personal perspective on receiving a diagnosis
of and being treated for cancer. Concurrently, the patients spontaneously share
common experiences about their cancer, which leads to strong emotional bonds. The
purpose and goals of the program, method of implementation, and evaluation are
described. Information and suggestions that clinicians might find useful in
developing similar programs are discussed. Patient participants, their families,
and staff in the cancer center have reported positive clinical evaluations.
CONCLUSIONS: The benefits of Healing Icons are derived from the therapeutic
factors present in a traditional support group blended with the creative process.
This kind of program opens new avenues for expressing feelings and thoughts but
should be structured in such a way that group processes are not allowed to
negatively impact participants. Healthcare professionals interested in
collaborating with artists on similar programs for cancer patients may approach
artists through local art councils, art schools, and artists guilds.
Brainstorming sessions with artists would help to capitalize on the expertise of
artists within the community. Initiating a pilot project would help gauge patient
interest and would provide valuable feedback from the healthcare team. Research
is needed to validate the clinical outcomes derived from this program, as
empirical findings would greatly enhance the clinical evaluations.
PMID- 10687584
TI - Reintegration after bone marrow transplantation.
AB - OBJECTIVES: This study examines the problems of bone marrow transplantation (BMT)
survivors in returning to "normal" life in the community after BMT. MATERIALS AND
METHODS: Before being released from The Johns Hopkins Oncology Center, 84
recipients of BMT were interviewed regarding their quality of life and
psychosocial adaptation. Survivors were reinterviewed at 6 months, and at 1 year
post-BMT, producing considerable qualitative data regarding their problems in
living. Eighty-four patients who had received BMT completed qualitative
interviews and standardized measures before treatment, before the return home,
and at 6 and 12 months post-BMT. The interviews were subjected to a content
analysis methodology to establish units and categories to examine the body of
material. RESULTS: Content analysis of these interviews from the first year after
BMT identified three areas of psychosocial morbidity; 1) physical problems, which
included fatigue, appearance, troubles in eating, and physical restrictions; 2)
psychological problems, which included fears about the future, sense of loss of
control, anxiety, and depression; and 3) community reintegration problems, which
included difficulty in returning to former social roles, separation from home,
family, and friends, difficulty in resuming social relations, dealing with
stigmatization, problems with family and children, and financial and employment
difficulties. CONCLUSIONS: Identification of these problems for BMT survivors can
be used to guide the development of specific materials and services to prepare
recipients of BMTs and their families for life after the transplant. These
qualitative results can also be used to direct the development of assessment
tools to identify potential patient and family problems.
PMID- 10687586
TI - The low-bacteria diet for immunocompromised patients. Reasonable prudence or
clinical superstition?
PMID- 10687585
TI - Findings from an educational support course for patients with leukemia.
AB - OBJECTIVES: Recent evidence indicates that patients with leukemia are a distinct
subset of cancer patients with specific adjustment issues and special needs for
support and follow-up. This article shares recent research findings on an
Australian educational support course, appropriately named Taking Control,
designed specifically for patients with leukemia and associated disorders.
MATERIALS AND METHODS: The material presented in this article represents the
findings from the retrospective arm of a descriptive study designed to evaluate
this course. Participants in the course during the calendar year of 1997 were
surveyed with an author-designed, self-report questionnaire requesting feedback
on their experience of the course. RESULTS: Although the majority of participants
were seeking information, there was strong evidence that the provision of
information needs to be coupled with an understanding of the psychosocial reasons
that motivated individuals to attend the course. The findings indicate that the
course is perceived by participants to be an effective psychosocial intervention
for assisting patients and their families cope with the serious diagnosis of
leukemia. CONCLUSIONS: Even though information seeking was an important reason
for attending this educational course, there were many other significant
emotional concerns that individuals brought to the experience. When exposed to
the stress of leukemia and its treatment, patients and their significant others
may become preoccupied with information gathering. Therefore, it is important to
not only explore the issue of the informational needs of participants, but also
to examine the emotional needs they associate with this information gathering.
The hope and expectation about sharing the findings of this program is that it
will assist with the development of similar programs elsewhere and will stimulate
further research on the importance of educational support groups in oncology.
PMID- 10687587
TI - Support groups for children of patients with cancer.
PMID- 10687588
TI - Sparfosate. A novel biomodulator of 5-fluorouracil.
PMID- 10687589
TI - Protection of human subjects. Time for reassessment.
PMID- 10687590
TI - Language barrier and psychiatric disorder as challenges to effective pain
management.
PMID- 10687591
TI - Factors hindering patients' use of medications for cancer pain.
AB - OBJECTIVES: The purpose of this study was to explore the reasons that cancer
patients with pain find it difficult to adhere to analgesic therapy. MATERIALS
AND METHODS: Twenty-one patients with advanced cancer with pain were interviewed
using a semistructured schedule of questions. Participants were asked to describe
their decision making regarding analgesics and the factors that made it difficult
for them to take analgesics prescribed for their pain. They also were asked to
describe their relationships with their healthcare providers. Themes were
identified and refined using qualitative analytic techniques. Two investigators
independently coded all data to ensure that findings accurately reflected
participants' experiences. RESULTS: Findings reveal several factors that hindered
analgesic use and the specific ways in which patients evaluated these factors in
making decisions about taking pain medication. The provider-patient factors that
impeded analgesic use also were described. Finally, the common use of
nonpharmacologic methods of pain control offers insight into the role of these
therapeutic strategies in achieving pain relief and decreasing analgesic use.
CONCLUSIONS: The findings underscore the importance of early intervention to
address barriers to analgesic use. Some barriers may be overcome through
educational efforts. The findings suggest, however, that consistent, repeated
patient education often may not be sufficient to subdue patients' negative
thoughts about taking the medication. Other approaches, such as changing
medications or assisting the patient to use nonpharmacologic pain strategies, may
prove more successful.
PMID- 10687592
TI - Screening to predict complicated grief in spouses of cancer patients.
AB - OBJECTIVES: Grief is the expected reaction to the death of a family member or
close friend and is accompanied by substantial distress for almost everyone who
experiences it. For some the grief response becomes complicated. This pilot study
sought to identify individuals at high risk for complicated grief, by 1)
examining the relationships that exist between family functioning before the
death, psychological distress, and the grief reaction of a family after the
death, and 2) presenting the use of screening with standardized measures to
identify those at risk. MATERIALS AND METHODS: This pilot study examined the
relationships between family functioning, psychological distress, and grief
reaction. A cross-sectional design was used and the instrument included the
Family Adaptability and Cohesion Evaluation Scale (FACES III), the Brief Symptom
Inventory (BSI), and the Texas Revised Inventory of Grief (TRIG). Significant
relationships were identified between the level of family functioning,
psychological distress and grief reaction. Depression, anxiety, and general
distress were significantly correlated with the two subscales of the TRIG.
CONCLUSIONS: The findings clearly illustrate the merit of psychosocial screening
of spouses and suggest the possible benefits of screening before the patient's
death, using FACES III and the BSI to identify which spouses are at risk for
complicated grief reactions.
PMID- 10687593
TI - Fatigue, pain, and depression in pre-autotransplant breast cancer patients.
AB - OBJECTIVES: The purpose of this study was to determine the influence of fatigue,
pain, and depression on health status in breast cancer patients who had completed
adjuvant chemotherapy and were scheduled for autologous bone marrow/peripheral
blood stem cell transplant (AT). MATERIALS AND METHODS: A predictive,
correlational design was used. A convenience sample of 127 women with stages II,
III, and IV breast cancer was recruited. The setting was an urban National Cancer
Institute-designated comprehensive cancer center located in the Eastern United
States. Standardized questionnaires and the Gaston-Johansson Painometer (POM)
were used to measure the variables. The subjects completed questionnaires in the
outpatient clinic. Relationships between the multiple dimensions of fatigue and
pain, depression, and health status were examined. Hierarchical regression
techniques were used to determine the variance in health status accounted for by
fatigue, pain, and depression. RESULTS: The subjects were age 22 to 60 years
(Mean = 45; SD = 7.6), and primarily were married, white, Protestant, college
educated, employed in a professional position, and had an average yearly
household income of equal to or greater than $50,000. All subjects had previously
received surgery and chemotherapy. Ninety-one percent of the participants
reported fatigue as measured by the Fatigue Visual Analogue Scale. Forty-seven
percent of the participants reported pain as measured by the Gaston-Johansson POM
visual analogue scale. Fifty-four percent of the participants reported
depression, ranging from mild to severe/high. Subjects reported a mean total
perceived health status rating of 50.73 (SD 10.79). Fatigue, pain, and depression
were all significantly correlated to each other and to total health status.
Depression (P < .001) and pain (P < .01) significantly accounted for 64%
(adjusted R2 = .60) of the variance in total health status. Fatigue (P < .05) and
depression (P < .001) accounted for 42% (adjusted R2 = .36) of the variance in
the perception of health status. CONCLUSIONS: Women with breast cancer previously
treated with chemotherapy and awaiting AT may experience fatigue, pain,
depression, and alterations in health status. Pain and depression had a
significant impact on a woman's total health status, whereas depression and
fatigue had an influence on perceived health status. Of the different dimensions
of health status, one's perceptions of health status had the strongest
correlation to total health status (r = .84, P < .001). Healthcare professionals
need to be aware of the effects of multiple symptoms on health status and to
provide appropriate care to alleviate them.
PMID- 10687594
TI - Parents' perceptions of randomization in pediatric clinical trials. Children
Cancer Group.
AB - OBJECTIVES: The purpose of this study was to investigate parents' knowledge and
perceptions about randomization in clinical trials for children with cancer, and
to determine whether parents' decisions were influenced by demographic factors,
randomization circumstances, the clinical characteristics of the child with
cancer, or a combination. MATERIALS AND METHODS: This study collected information
from 192 parents of patients with various forms of childhood cancer who either
accepted or refused randomization. A comparative case-control design was used.
The Clinical Investigation Randomization Scale was administered to all
participants. This scale included 32 questionnaire items (QIs) pertaining to
randomization as well as a mixture of open-ended questions to obtain information
about demographic and other factors. RESULTS: A predictor model was developed
that accurately predicted acceptance or refusal of randomization 87% of the time.
Demographic information was found to have less influence than expected on
parents' decisions regarding randomization. Knowledge deficits were found among
both groups of parents, those who accepted and those who refused randomization.
CONCLUSIONS: What most distinguished parents who refused from those who accepted
randomization was not their knowledge and information about randomized clinical
trials. By far, the majority of QIs that accurately predicted acceptors and
refusers involved parents' beliefs, values, and perceptions. Further research is
needed to determine interventions that may enable the healthcare team to provide
information and decisional support most effectively to improve the informed
consent process.
PMID- 10687595
TI - Patient and caregiver perceptions of cancer pain control.
AB - OBJECTIVES: This study measured the perceptions of cancer patients and caregivers
in Utah concerning knowledge about and adequacy of pharmacologic cancer pain
control. MATERIALS AND METHODS: A descriptive survey was sent to a stratified
random sample of adult cancer patients obtained from the Utah Tumor Registry.
Questionnaires asked cancer patients and caregivers about their knowledge of pain
control and about perceptions of the adequacy of pharmacologic cancer pain
management. RESULTS: The study had a 52% response rate (259 of 500) after two
mailings. Eighty-five percent (219 of 259) of the respondents stated that they
had no cancer pain. With the first mailing, a "no pain" response was not offered
as an option. When the researchers realized that this might be a possible
response, a second mailing was sent, which may be the reason for the high
response rate. CONCLUSIONS: Cancer literature indicates that much cancer pain is
not effectively controlled. The majority of the respondents of this study
reported no pain. Because this result is different than that reported in the
literature, it may indicate that education of healthcare providers, patients, and
families can improve cancer pain management and control. It may also indicate an
inability of the study to obtain data from those patients having cancer pain.
This study should be repeated with a focused population of advanced stage cancer
patients with types of cancer typically producing high levels of cancer pain.
PMID- 10687596
TI - Educational needs related to complementary and alternative therapies.
PMID- 10687597
TI - The Internet. Changing the way cancer survivors obtain information.
PMID- 10687598
TI - Taxanes in hormone-refractory prostate cancer.
PMID- 10687599
TI - Nursing shortages threaten patient care.
PMID- 10687600
TI - Getting a job as a research nurse.
PMID- 10687601
TI - The reality of nursing education in the '90s.
PMID- 10687602
TI - Students helping students.
PMID- 10687603
TI - Workforce planning essential.
PMID- 10687604
TI - Linking nurse prescribing and advanced practice.
PMID- 10687605
TI - Future nursing realities.
PMID- 10687606
TI - Working with a team.
PMID- 10687607
TI - Commentary: orchestrating a complex situation.
PMID- 10687608
TI - The rewards of being a caregiver.
PMID- 10687609
TI - Homecare workers undervalued.
PMID- 10687610
TI - Undergoing hyperbaric oxygen therapy.
PMID- 10687611
TI - Raising awareness of legal risks.
PMID- 10687612
TI - Working for positive change.
PMID- 10687613
TI - New therapies enhance patient care.
PMID- 10687614
TI - Onus on nurses to practise safely.
PMID- 10687615
TI - Recapturing the essence of nursing. Interview by Teresa O'Connor.
PMID- 10687616
TI - Fulfilling a dream. Interview by Anne Manchester.
PMID- 10687617
TI - Healing touch benefits patients. Interview by Anne Manchester.
PMID- 10687618
TI - The impact of the new right on health care.
PMID- 10687619
TI - Pondering nurses' industrial future.
PMID- 10687620
TI - Devastating illness paralyses body.
AB - A patient diagnosed with Guillain-Barre syndrome discovered most health
professionals knew little about the disease. He wrote this article in September
last year--11 months after the onset of his illness.
PMID- 10687622
TI - Report highlights medical dilemmas.
PMID- 10687621
TI - The joy and privilege of caring.
AB - Some patients have a profound effect on nurses. One nurse recalls the joy and
privilege of caring for a much-loved old woman.
PMID- 10687623
TI - Analyzing the Mental Health Act.
AB - The Mental Health Act has brought significant changes to clinical practice. Here
one nurse examines some of these changes and some of the difficulties nurses have
in working under the Act.
PMID- 10687624
TI - Paying tribute to Maori values.
PMID- 10687625
TI - Understanding what makes people tick. Interview by Anne Manchester.
PMID- 10687626
TI - Youthful challenges. Interview by Teresa O'Connor.
PMID- 10687627
TI - Managing professional boundaries.
PMID- 10687628
TI - Advancing nursing education.
PMID- 10687629
TI - Making partnership a reality.
PMID- 10687630
TI - A window on mental health nursing.
PMID- 10687631
TI - On the road to openness.
PMID- 10687632
TI - Nurses in waiting.
PMID- 10687633
TI - Losing patience.
PMID- 10687634
TI - Nursing by numbers.
PMID- 10687635
TI - The big issue. Interview by Jenny Knight.
PMID- 10687636
TI - Cuddle mums.
PMID- 10687637
TI - Acting on health.
PMID- 10687638
TI - Meet nurse perfect.
PMID- 10687639
TI - Responding to disability.
PMID- 10687640
TI - Nurses' attitudes to the extension and expansion of their clinical roles.
AB - Nurses are increasingly being asked to extend or expand their traditional roles,
often for reasons other than their own professional development. This study,
across three specialties in one hospital, examines whether or not nurses view
such change in a positive light.
PMID- 10687641
TI - Improving paediatric diabetes care.
AB - The authors review the management of paediatric patients in diabetic
ketoacidosis. Paying particular attention to the pathophysiology of the illness
and nursing documentation, they have developed a new diabetic ketoacidosis flow
chart to improve nursing care.
PMID- 10687642
TI - Quality and the new NHS.
AB - In this article, the authors explore the concept of quality in health care and
examine in detail some of the methods currently being used to assess and improve
it.
PMID- 10687643
TI - Holistic care for a man with prostate disease.
PMID- 10687644
TI - The bank for you.
PMID- 10687645
TI - Rights and responsibilities.
PMID- 10687646
TI - The new Japanese Society of Pressure Ulcers: an opportunity for international
collaboration.
PMID- 10687647
TI - Update: SNF PPS and consolidated billing.
AB - Wound, ostomy, and continence specialists have a unique opportunity for
developing programs in the long-term care environment. Their expertise and
perspective can assist in providing care within the PPS payment rate, improving
the fiscal stature of the facility, improving patient outcomes, and increasing
the facility's referral base. The HCFA has posted a tool on its website that
allows the user to follow RUG III grouper logic manually. It walks through each
step of the process and is designed to be a helpful learning tool:
http:@www.hcfa.gov/medicare/hsqb/mds20/>.
PMID- 10687649
TI - Facilitating international wound care communication and sharing.
PMID- 10687648
TI - Issues of euthanasia.
AB - The debate surrounding euthanasia may have existed before recorded history, yet
it continues today. Advanced technology, with its implication on prolonging life
and postponing death in some cases, further complicates the debate. This column
includes a historical review of euthanasia, related terminology, and proposed
guidelines. The implications of recent legislation on enhancing discussions
around terminal care are also reviewed.
PMID- 10687650
TI - Downloading plantar foot pressures in the diabetic patient.
AB - Pressure downloading (offloading) is the most important component in the
prevention and treatment of diabetic foot ulcers because peripheral neuropathy is
a major contributing factor to more than 90% of all diabetic foot ulcers.
Downloading techniques range from the simplest insole, through many types of
orthotics and footwear modifications including the ankle-foot orthosis and total
contact casting, to surgical procedures. A philosophical difference exists
between surgical and nonsurgical approaches, with the patient subjected to the
bias of the practitioner. This article explores uniting both surgical and
nonsurgical pressure downloading techniques, using a modified Carville
Classification System to help the practitioner determine the appropriate
method(s) of downloading. By adding a Category 4 to include diabetic persons with
foot ulcers or acute Charcot events, a seamless system is obtained to categorize
and treat all people with diabetes with pressure downloading recommendations.
PMID- 10687651
TI - Clinical efficacy and cost-effectiveness of a new synthetic polymer sheet wound
dressing.
AB - Stage II and III pressure ulcers present product development and product choice
challenges to manufacturers and professional wound care clinicians respectively.
We evaluated the clinical performance and cost of use associated with a new
synthetic polymer dressing for the management of these wounds. A total of 10 home
healthcare patients, each with a Stage II or III pressure ulcer, were enrolled
and randomized for wound treatment using either the new polymer hydrogel wound
dressing or the leading market hydrocolloid dressing. Dressings were changed on
an as needed basis only. The wounds were assessed weekly and parameters recorded
using the Bates-Jensen Pressure Sore Status Tool. In addition, the clinical
performance of the dressing and treatment costs were evaluated. The overall
healing rate for the two groups was similar. However the new polymer hydrogel
dressing was found to have a more favorable overall clinical performance
evaluation based largely on its more favorable support of autolytic debridement.
The new polymeric dressing also had a more favorable cost of use based on the
evaluation. We conclude that the new polymer dressing may be a favorable
alternative to the leading market hydrocolloid dressing for the treatment of
Stage II and III pressure ulcers due to a better clinical performance and the
substantially lower treatment costs associated with its use.
PMID- 10687653
TI - A moral abomination: food for thought.
PMID- 10687652
TI - The effects of UVC irradiation on group A streptococcus in vitro.
AB - Streptococcus pyogenes (group A streptococcus--GAS) is a common cause of
necrotizing fasciitis (NF)--a severe infection of the subcutaneous soft tissue.
The purpose of this study was to determine if the topical therapy ultraviolet
light C (UVC) is effective in killing GAS in vitro and to evaluate the most
effective treatment parameters for use with UVC therapy. Five replications of GAS
at 10(8) organisms/mL were plated. The cultures were treated with a UVC light 1
inch from the surface. Irradiation times were as follows: 0, 2, 3, 4, 5, 15, 30,
45, 60, 90, 120, and 180 seconds. Bacterial cultures were incubated and colony
counts performed. A second set of GAS cultures were exposed to UVC for 30, 90,
and 120 seconds either once daily (qd) or twice daily (bid). Kill rates were
99.9% for GAS at 4 seconds to 180 seconds. Kill rates of 99.9% were also obtained
at 30 seconds and 90 seconds when UVC treatment was given either qd or bid. This
data indicates that UVC is bactericidal for GAS at times as short as 4 seconds.
In addition, UVC treatment was not effective when administered through thin film
dressings.
PMID- 10687654
TI - Barriers to informed consent in clinical trials.
AB - Clinical trials are a type of scientific study conducted in human beings. They
are designed to evaluate the safety and effectiveness of new drugs, procedures,
or other means of treating, diagnosing, or preventing diseases. The ethical
issues involved in clinical trials are nothing new, but because of the increased
access to studies, they are steadily affecting more people. The sheer volume of
clinical trials, as well as the number of patients and professionals involved in
them, has increased in the past decade. Informed consent is a key element of
clinical research. Meaningful informed consent requires that subjects weight the
associated risks and benefits of an experimental intervention and then
voluntarily give consent. One concern regarding informed consent in research is
the confusion between therapeutic intervention and experimental treatment. This
confusion could lead to barriers in informed consent. This column addresses this
concern and includes a case study to illustrate the misunderstandings that might
arise from the patient who is compelled to consent to clinical trials because of
his sense of hopelessness from a chronic health condition and the traditional
medical intervention he is receiving.
PMID- 10687655
TI - Exploring a new path toward global understanding of wound care.
PMID- 10687656
TI - The development of a national registration form to measure the prevalence of
pressure ulcers in The Netherlands.
AB - To gain insight into the prevalence of pressure ulcers in Dutch healthcare
institutions, a national registration form to measure the prevalence of pressure
ulcers annually in different healthcare settings was developed based on a
literature study and responses from a Delphi panel. The reliability and the
feasibility of the form devised were tested in a pilot study conducted in a
university hospital, a nursing home, and in a home healthcare setting. Interrater
reliability of the grading system varied between the institutions from 0.49 to
0.97 (Cohen's Kappa). In the home healthcare setting, interrater reliability was
0.80 (Pearson correlation coefficient) for the total score on the Braden scale.
The prevalence rates were 10.1% (n = 368) in the university hospital, 12.7% (n =
1,541) in the home healthcare setting, and 83.6% (n = 122) in the nursing home,
although the latter figure seemed to be somewhat exaggerated. The most common
lesions were found on the sacrum and below the knee (heel and malleolus). The
pilot study concluded that it is possible to collect accurate and reliable data
on the scope and severity of pressure ulcers with a uniform instrument in
different healthcare settings.
PMID- 10687657
TI - The clinical and cost effectiveness of externally applied negative pressure wound
therapy in the treatment of wounds in home healthcare Medicare patients.
AB - Pressure ulcers, a devastating and costly healthcare problem, often occur in home
healthcare settings. We sought to determine if these and other chronic wounds
treated at home with negative pressure wound therapy close faster and reduce
treatment costs compared to conventional therapies. Records for 1,032 Medicare
home healthcare patients with 1,170 wounds that failed to respond to previous
interventions--and were subsequently treated with negative pressure wound therapy
-were reviewed. Reductions in wound area and volume were compared to rates
reported by Ferrell in 1993, and costs were analyzed. Ferrell reported
trochanteric and trunk pressure ulcers averaging 4.3 cm2, treated with a low-air
loss surface and saline-soaked gauze closed at an average of 0.090 cm2 per day.
For comparison to Ferrell's outcomes, we analyzed our Stage III and IV
trochanteric and trunk wounds treated with low-air-loss and negative pressure
wound therapy. Ours averaged 22.2 cm2 in area and closed at an average of 0.23
cm2 per day. The average 22.2 cm2 wound in our study, treated as described by
Ferrell, would take 247 days to heal and cost $23,465. Using negative pressure
wound therapy, the wound would heal in 97 days and cost $14,546. The study
concluded that negative pressure wound therapy is an efficacious and economical
treatment modality for a variety of chronic wounds.
PMID- 10687658
TI - Stoma management in a tropical country: colostomy irrigation versus natural
evacuation.
AB - People with ostomies in Singapore were initially resistant to colostomy
irrigation. This study, a prospective crossover study of 26 patients who
underwent abdominoperineal resection, compared colostomy irrigation with the
natural evacuation method. During the colostomy-irrigation phase of the study,
all 26 patients reported an improvement in continence and fewer problems with
sleep, sex, and skin complications compared to the natural-evacuation phase. The
study also found a reduction in monthly expenses with colostomy irrigation
compared to natural evacuation. Patient satisfaction scores were also superior
during the colostomy-irrigation phase. This difference in satisfaction scores was
less marked in those who were more than 1-year postsurgery than in those who were
less than 1-year postsurgery. The difference in satisfaction between colostomy
irrigation and natural evacuation scores was statistically significant in the
group that was less than 1-year postsurgery, but not in the group that was more
than 1-year postsurgery. The study concluded that colostomy irrigation after
abdominoperineal resection is superior to natural evacuation in terms of cost and
patient satisfaction and should be introduced soon after surgery.
PMID- 10687659
TI - Using telemedicine in the treatment of pressure ulcers.
AB - Pressure ulcers are dynamic and therefore require frequent assessment and
immediate treatment. For many patients who live long distances from
rehabilitation hospitals, frequent assessment and immediate treatment are often
unavailable. Recent advances during the last two decades have resulted in the
development of telemedicine--long-distance delivery of medical education and
services to patients. This pilot study reports on a patient enrolled in a
telemedicine program during his fifth hospitalization for pressure ulcers in 16
months. Although this is only a single case study, the results suggest the
potential efficacy of this new intervention.
PMID- 10687660
TI - Entering the 21st century: moving incontinence treatment options to the
forefront.
PMID- 10687661
TI - A case of ethics and patient rights.
PMID- 10687662
TI - Competency in informed consent.
AB - Assessing a patient's capacity to make competent decisions concerning her own
care is an important clinical skill in healthcare, especially among those who are
elderly, chronically ill, and institutionalized. Competency is an important
presupposition to autonomous decision making. Assessing competency becomes
increasingly critical when the patient's wish is to forego a life-saving
procedure. Supporting a patient's choice regardless of the outcome of that
decision is an important part of patient advocacy and therefore an important
component of patient care. The essence of autonomy is described as it relates to
defining meaningful informed consent. This article includes a model for assessing
competence.
PMID- 10687663
TI - Getting bruised in new places.
PMID- 10687664
TI - Health and wound care in Ireland: an American's view.
PMID- 10687665
TI - Incontinence and PPS: a new era.
AB - Urinary incontinence (UI) is a prevalent and costly problem in nursing homes.
Assessing residents with incontinence is necessary to determine the
pathophysiologic causes and associated factors that can interfere with self
toileting. Nurses can perform this assessment at the bedside. Guideline tools
have been developed to assist nursing home staff through the evaluation of UI and
intervention. Treatment techniques, specifically behavioral interventions and
toileting assistance programs, can be readily incorporated into nursing practice.
Most nursing home staffs can easily implement interventions such as bowel and
nighttime voiding management and dietary modifications. Nursing home research has
demonstrated the effectiveness of toileting assistance programs; however, very
little of this research and documented techniques has been used by nursing home
staff. Scheduled toileting and bladder training programs can be successfully
implemented in nursing home residents. The key to the success of these programs
is identifying residents who should be targeted for each specific program. Staff
education remains an ongoing issue, as caregivers must be aware of attitudes and
beliefs about the aging process and its impact on the genitourinary system in
order to provide effective care. Under the Prospective Payment System, nursing
homes need to change business as usual and remain abreast of new innovations and
research in different behavioral interventions and continence technology.
PMID- 10687666
TI - Toileting assistance based on bladder volume.
PMID- 10687667
TI - Sleep-disordered breathing as a mechanism for nocturia: preliminary findings.
AB - Nocturia is commonly associated with prostate or bladder problems but is also an
important symptom of obstructive sleep apnea, a potentially lethal condition. The
primary purpose of this study was to test the relationship between symptoms of
sleep-disordered breathing and increased nocturnal urine production as described
by the Sleep-Disordered Breathing--Nocturia Model. The purpose of the first phase
of this three-phase study was to survey community-dwelling older adults (> 55
years) about nocturia and sleep-disturbance symptoms. A random sample of 1,000
older adults, balanced by ethnicity and gender, were surveyed via a mailed
questionnaire. The brief questionnaire included characterizing poor sleep
quality, obstructive sleep apnea symptoms, nocturia, lower urinary tract
symptoms, naps, and self-rated health. The return rate was low (18%, n = 176),
but respondents were equally represented by gender and ethnicity across the
targeted age groups. Half of the respondents (n = 87) reported > or = 2 voids per
night, two-thirds of whom reported nocturia as bothersome. The data showed that
African-American women had significant associations between episodes of nocturia
and symptoms of obstructive sleep apnea, poor sleep quality, naps, and lower
urinary tract symptoms, thus failing to support the notion that nocturia or sleep
disordered breathing are prostate or gender related. As expected, subjects (n =
80) who volunteered for the later phases of the study, had significantly more
problems. These preliminary data suggest that the relationship between
obstructive sleep apnea and nocturia is important because older adults are at
higher risk of injury due to falls that may occur while attempting to toilet in
the dark. Also, older adults may also be at higher risk of receiving
inappropriate urologic treatment if they are not screened for sleep disorders
when reporting nocturia along with symptoms of excessive daytime sleepiness and
sleep-disordered breathing. Phases II and III of the parent study will include a
detailed examination of hormonal, biochemical, and physical variables to further
test the proposed Sleep-Disordered Breathing--Nocturia Model.
PMID- 10687668
TI - Initial antiarrhythmic drug therapy during resuscitation from sudden cardiac
death: a time for a fundamental change in strategy?
PMID- 10687669
TI - Pharmacological management of atrial fibrillation: an update.
AB - Therapy of atrial fibrillation remains difficult in many patients. There is
increasing awareness that antiarrhythmic drug therapy instituted to maintain
sinus rhythm after successful cardioversion of atrial fibrillation may pose a
substantial risk to the patient. Therefore, results of prospective randomized
trials are needed to allow a more evidence-based approach to the treatment of
this common arrhythmia. Two recently published studies have shown superiority of
amiodarone over conventional antiarrhythmic drugs in maintaining sinus rhythm.
The largest such study published today, the Canadian Trial in Atrial Fibrillation
(CTAF), has randomized 403 patients to amiodarone or to sotalol or propafenone.
At the end of the observation period, amiodarone-treated patients were
significantly more likely to remain in sinus rhythm than conventionally treated
patients. A number of new antiarrhythmic drugs, mainly class III substances, are
currently developed for the treatment of atrial fibrillation or atrial flutter.
Ibutilide has recently been released for intravenous administration, attempting
pharmacological cardioversion of atrial fibrillation/atrial flutter. It has been
evaluated in a number of prospective trials, which showed a higher conversion
rate in patients with atrial flutter. Dofetilide is another new compound
developed mainly for maintenance of sinus rhythm after restoration of sinus
rhythm. It has been evaluated in two prospective, randomized, placebo-controlled
trials; moreover, analysis of the DIAMOND trials showed effectiveness of
dofetilide in maintaining sinus rhythm in patients with depressed left
ventricular function without increased mortality when compared with placebo.
Finally, several ongoing studies compare the therapeutic strategy of controlling
ventricular rate in atrial fibrillation compared with the strategy of maintaining
sinus rhythm. These trials will help to optimize therapy in atrial fibrillation,
the most commonly encountered arrhythmia.
PMID- 10687670
TI - The importance of considering trial design when interpreting clinical trial
results.
AB - BACKGROUND: In recent decades, clinical trials have played an increasingly
important role in determining how we practice. Trial results proving that a
clinical finding poses risk have led to interventions that try to reduce risk.
Clinical trials proving that a particular therapy provides better outcome than
another therapy have changed the therapies we now use. Unfortunately, the results
of clinical trials are too often affected by biases or design issues that may
overtly or covertly alter the results or the way they should really be used. In
addition, these biases and design and analysis issues are rarely evident in the
abstract sections or key figures and tables in the publications reporting the
trials, which may be all the busy physician either reads or remembers. METHODS
AND MATERIALS: This manuscript discusses the issues involved in optimally
understanding clinical trial design and interpretation so that practitioners can
better understand how to intelligently read and apply trial results to clinical
practice. CONCLUSIONS: Clinical trial results can not be properly applied without
consideration of trial design features and intertrial comparisons.
PMID- 10687671
TI - Efficacy of atorvastatin compared with simvastatin in patients with
hypercholesterolemia.
AB - BACKGROUND: Atorvastatin, a new enantiomerically pure synthetic statin, has shown
a marked low-density lipoprotein (LDL) cholesterol reduction at doses ranging
from 10 to 80 mg/d. This trial was designed to compare the efficacy of
atorvastatin 10 mg with simvastatin 10 mg and 20 mg, the latter dose being
commonly used in some countries. METHODS AND RESULTS: A parallel group,
randomized, PROBE, multicenter study was conducted to compare the efficacy of 10
mg/d atorvastatin with that of 10 mg/d simvastatin and 20 mg/d simvastatin in
patients with primary hypercholesterolemia. After a 6-week diet-placebo lead-in
period, 272 patients with LDL cholesterol > or = 160 mg/dL and triglycerides < or
= 300 mg/dL were randomized to 6 weeks of treatment with atorvastatin 10 mg (109
patients), simvastatin 20 mg (109 patients), or simvastatin 10 mg (54 patients).
In the main analysis, which tested the equivalence of atorvastatin 10 mg and
simvastatin 20 mg, the mean percent change in LDL cholesterol for atorvastatin 10
mg (-37.0%) was greater than and not equivalent to simvastatin 20 mg (-33.8%). In
the secondary analysis, which compared the efficacy of atorvastatin 10 mg with
that of simvastatin 10 mg, the mean decrease in LDL cholesterol was significantly
greater (P < .001) for atorvastatin 10 mg than for simvastatin 10 mg (-37.0% vs.
28.9%). The two drugs were well tolerated, with an incidence of clinical and
biochemical side effects similar among the 3 treatment groups. CONCLUSION: In
primary hypercholesterolemia, atorvastatin 10 mg was more effective and
nonequivalent to simvastatin 20 mg and significantly more effective than
simvastatin 10 mg for reducing LDL cholesterol levels.
PMID- 10687672
TI - Acute renal failure after cardiopulmonary bypass: a possible association with
drugs of the fibrate group.
AB - BACKGROUND: Renal failure is a recognized, but infrequent, complication following
cardiac surgery. The causes for this condition are multifactorial, and a major
concern is that the occurrence of postoperative acute renal failure is still
associated with a high mortality rate. METHODS AND MATERIALS: We report
unexpected acute renal failure occurring in 4 patients after uncomplicated
cardiac surgery. Each patient was taking a fibric acid derivative at the time of
surgery. Renal failure occurred rapidly within 3 days of surgery and was
associated with increased concentrations of skeletal muscle-derived creatine
kinase (CK). One patient developed myoglobinuria, and another developed a
malignant hyperthermia-like syndrome. CONCLUSIONS: These cases show that patients
receiving lipid lowering medications could be at higher risk of developing acute
renal failure after cardiac surgery. This association merits careful evaluation
in large prospective studies and, if proved, would suggest that patients taking
either statins or fibrates should discontinue doing so before cardiac surgery.
PMID- 10687673
TI - A new model of ventricular plication: a suturing technique to decrease left
ventricular dimensions, improve contractility, and attenuate ventricular
remodeling after myocardial infarction in the rat heart.
AB - BACKGROUND: The Batista procedure (cardio-reduction) is a surgical technique in
patients with dilated cardiomyopathy that results in improvement of ventricular
function. The purpose of this study was to test a new suturing technique without
resection for cardio-reduction of myocardial infarct scars in rats. METHODS AND
RESULTS: Myocardial infarction (MI) was induced by occluding the left coronary
artery 4 weeks before enrollment. Animals then were randomized to a control (n =
11) or treatment group (n = 11). A pursestring suture was placed within the
border zones of the infarcted area and was either tightened (treated) or not
(controls). Echocardiography was used to measure left ventricular diameters
before, 1 hour, and 6 to 7 weeks after plication. Acutely after plication, end
diastolic length (EDL) decreased from 0.70 +/- 0.03 cm to 0.53 +/- 0.02 cm, P <
.001; end-systolic length (ESL) decreased from 0.51 +/- 0.03 cm to 0.23 +/- 0.02
cm, P < .001; and fractional shortening (FS) increased from 27.6 +/- 1.5% to 57.6
+/- 2.3%, P < .001, whereas controls were unchanged. In control rats EDL
increased from baseline at 0.73 +/- 0.02 cm to 0.82 +/- 0.04 cm at 6 weeks
postsurgery, P < .05; ESL increased from 0.54 +/- 0.02 cm to 0.66 +/- 0.04 cm, P
< .005; and FS decreased from 26.9 +/- 1.1% to 19.2 +/- 1.2% at 6 weeks, P < .05.
In contrast, at 6 weeks in plicated animals, EDL was significantly less than
controls at 0.64 +/- 0.02 cm, P < .005; ESL was significantly less than controls
at 0.39 +/- 0.03 cm, P < .005, and FS was significantly better than controls at
40.5 +/- 2.2%, P < .005. CONCLUSION: The progressive LV enlargement between 4 and
10 weeks after MI reflects late ventricular remodeling. Plication by suturing
infarcted tissue acutely decreases diameters and improves function. At 6 weeks,
function remains improved over untreated animals.
PMID- 10687674
TI - Beneficial effects of vitamin E treatment in acute myocardial infarction.
AB - BACKGROUND: Vitamin E (Vit E), an antioxidant, is considered to prolong survival
in patients and animals after myocardial infarction. Because myocardial
infarction is associated with arrhythmia and heart dysfunction, this study tested
the hypothesis that early treatment with Vit E reduces mortality because of its
protective effects against arrhythmia and cardiac dysfunction induced by acute
myocardial infarction. METHODS: Rats were randomly divided into 4 groups: sham
control, myocardial infarcted, Vit E-treated sham control, and Vit E-treated
infarcted animals. Myocardial infarction was induced by ligation of the left
anterior descending coronary artery. Treated animals received Vit E (25 mg/kg/d)
through a gastric tube beginning 1 hour after the coronary occlusion, whereas
control rats received tap water. RESULTS: Electrocardiograms (lead II) at 1, 3,
7, and 21 days after coronary occlusion in the untreated animals showed ST
segment elevation, abnormal Q waves, premature ventricular complex (PVC), and QTc
prolongation. Conversely, Vit E-treated rats showed attenuated ST-segment
changes, fewer abnormal Q waves, and decreased incidence of PVC after coronary
occlusion. Total mortality was reduced from 38% to 16%, whereas the infarct size
was decreased from 44.2% to 22.3% in infarcted rats treated with Vit E. The
depression in left ventricular function as well as elevation of malondialdehyde
content and conjugated diene formation in the 21-day infarcted rat hearts were
prevented by Vit E treatment. CONCLUSION: These results indicate that Vit E may
exert beneficial effects on the heart by reducing oxidative stress in acute
myocardial infarction.
PMID- 10687676
TI - Transient acoustic wave propagation in rigid porous media: a time-domain approach
AB - Wave propagation of acoustic waves in porous media is considered. The medium is
assumed to have a rigid frame, so that the propagation takes place in the air
which fills the material. The Euler equation and the constitutive relation are
generalized to take into account the dispersive nature of these media. It is
shown that the connection between the fractional calculus and the behavior of
materials with memory allows time-domain wave equations, the coefficients of
which are no longer frequency dependent, to be worked out. These equations are
suited for direct and inverse scattering problems, and lead to the complete
determination of the porous medium parameters.
PMID- 10687675
TI - Cardiovascular dysfunction in hypercholesterolemia associated with enhanced
formation of AT1-receptor and of eicosanoids.
AB - BACKGROUND: In hypercholesterolemia with or without atherosclerosis
cardiovascular dysfunction and altered signalling of angiotensin (Ang II), nitric
oxide (NO), or prostanoids are intimately related to enhanced oxidant stress and
concomitant changes in gene expression. We analyzed cardiac angiotensin receptor
(AT1) expression and metabolism of Ang II, eicosanoids, and NO in
hypercholesterolemic animals. METHODS: Guinea pigs were fed a 1% cholesterol diet
for 8 weeks (Chol). Hemodynamics were analyzed in Langendorff hearts.
Spectrophotometric determination of plasma lipids and radioimmunological
detection of eicosanoids/cyclic guanosine monophosphate (cGMP). Activities of NO
synthase III (NOS-III) or angiotensin converting enzyme (ACE) were determined by
enzymatic assays. AT1 receptor density was assessed by radioligand binding assay.
NOS-III mRNAs were quantitated by reverse transcription polymerase chain
reaction. RESULTS: Hypercholesterolemia was associated with fatty degeneration of
the liver and profound myocardial and coronary (e.g., endothelial) dysfunction.
In Chol Langendorff hearts we observed significant increases in coronary flow
(26.0 +/- 1.0 vs. 17.5 +/- 0.5 mL/min/g tissue) but diminished coronary responses
to bradykinin (Bk, 250 ng bolus) or adenosine (Ado, 250 micrograms bolus) (delta
CPPBk/Ado: 5 +/- 0.5 vs. 7.2 +/- 1/0.9 +/- 0.1 vs. 1.9 +/- 0.3 cm2 (area under
the curve)). AT1 receptor expression was significantly increased in Chol hearts
(72 +/- 6.8 vs. 45 +/- 5.6 fmol/mg protein), whereas marked suppression of
cardiac activities of ACE (1.96 +/- 0.34 vs. 4.90 +/- 0.20 nmol/min/mg tissue)
and of the entire cardiac nitric oxide-cGMP axis (e.g., NOS-III activity: 1.9 +/-
0.4 vs. 3.1 +/- 0.1 pmol/min/mg tissue; NOS-III mRNA: 0.82 +/- 0.16 vs. 1.20 +/-
0.12 arbitrary units; cGMP release: 0.41 +/- 0.02 vs. 0.54 +/- 0.04 pmol/min/g
tissue) were shown in Chol. Finally, cardiac release of eicosanoids prostacyclin
(PGI2) and thromboxane (TxA2) were significantly enhanced (0.48 +/- 0.05 vs. 0.38
+/- 0.05 and 0.60 +/- 0.10 vs. 0.24 +/- 0.10 ng/min/g tissue, respectively).
Enhanced cardiac PGI2 release and suppression of cGMP synthesis in Chol were even
more pronounced on stimulation with Bk (38.2 +/- 3.0 vs. 28.2 +/- 2.0 ng/min/g
tissue and 1.9 +/- 0.3 vs. 3.0 +/- 0.3 pmol/min/g tissue, respectively).
CONCLUSIONS: Altered angiotensin-mediated signal transduction probably related to
augmented eicosanoid formation does not compensate for the limited endogenous NO
production and for cardiovascular dysfunction in hypercholesterolemic guinea
pigs. In this context, changes in redox-sensitive regulation of gene expression
(AT1 receptor, NOS-III--caused by enhanced oxidant stress--could play a pivotal
role.
PMID- 10687677
TI - Backscattering enhancements for tilted solid plastic cylinders in water due to
the caustic merging transition: observations and theory
AB - Bulk shear and longitudinal waves give rise to important contributions to the
scattering of ultrasound by tilted finite plastic and rubber cylinders in water.
This occurs in situations where either the shear or longitudinal speed is less
than the speed of sound in the surrounding water. At a certain critical tilt
angle, large backscattering enhancements are observed for finite cylinders, where
the wave vector can reverse direction upon reflection from the cylinder
truncation. The scattering process is analogous to the enhancement produced by
the merging of rainbow caustics of primary rainbow rays in the scattering of
light by long dielectric cylinders, also known as the caustic merging transition
[C. M. Mount, D. B. Thiessen, and P. L. Marston, Appl. Opt. 37, 1534-1539
(1998)]. A ray theory was developed to model the backscattering mechanism at the
critical tilt angle. It employs the idea of the Bravais effective refractive
index, convenient for constructing ray diagrams for the projections of rays in
the base plane of the cylinder. There is general agreement between the theory and
the experiment down to relatively low ultrasonic frequencies (ka as small as 10).
The enhancement is the most significant backscattering contribution for a wide
range of tilt angles.
PMID- 10687678
TI - Acoustic scattering by a modified Werner method
AB - A modified integral Werner method is used to calculate pressure scattered by an
axisymmetric body immersed in a perfect and compressible fluid subject to a
harmonic acoustic field. This integral representation is built as the sum of a
potential of a simple layer and a potential of volume. It is equivalent to the
exterior Helmholtz problem with Neumann boundary condition for all real wave
numbers of the incident acoustic field. For elastic structure scattering
problems, the modified Werner method is coupled with an elastodynamic integral
formulation in order to account for the elastic contribution of the displacement
field at the fluid/structure interface. The resulting system of integral
equations is solved by the collocation method with a quadratic interpolation. The
introduction of a weighting factor in the modified Werner method decreases the
number of volume elements necessary for a good convergence of results. This
approach becomes very competitive when it is compared with other integral methods
that are valid for all wave numbers. A numerical comparison with an experiment on
a tungsten carbide end-capped cylinder allows a glimpse of the interesting
possibilities for using the coupling of the modified Werner method and the
integral elastodynamic equation used in this research.
PMID- 10687679
TI - New explicit solutions in acoustics of closed spaces on the basis of divergent
series
AB - A new approach to the acoustics of closed spaces is developed that involves
solutions for polygonal shapes in explicit form. It is shown that exact solutions
can be constructed for polygonal geometries where all the interior angles are
equal to pi/n (n is an integer). It is stated that the set of such polygons
consists of the rectangle (known result) and three types of triangles. Some new
explicit formulas are obtained for the eigenfrequencies of the triangles. It is
demonstrated that the proposed technique also permits an exact representation of
the impulse response function for the geometries described.
PMID- 10687680
TI - Acoustics of a flanged cylindrical pipe using singular basis functions
AB - The problem of acoustic radiation from a cylindrical pipe with an infinite flange
has been discussed in a number of papers. The most common approach is to
decompose the field inside the pipe over a basis of Bessel functions. A very
large number of basis functions is usually required, with a large degree of
ripple appearing as an artifact in the solution. In this paper it is shown that a
close analysis of the velocity field near the corner yields a new family of
functions, which are called "edge functions." Using this set of functions as test
functions and applying the moment method on the boundary between the waveguide
and free space, a solution is obtained with greatly improved convergence
properties and no ripple.
PMID- 10687681
TI - Intensity streamlines and vorticity streamlines in three-dimensional sound fields
AB - The properties of intensity streamlines and vorticity streamlines are discussed
in this paper. It is found that the properties in three-dimensional sound fields
are different from the properties in two-dimensional sound fields. The integral
behavior of intensity streamlines is that the beginning and the end are attached
to a sound source surface or that the beginning is on the sound source surface
and the end extends into the infinite. For the vorticity streamlines, the
integral behavior is that it is a closed curve or that the beginning and the end
are attached to the sound source surface. Three examples are given for intensity
and vorticity streamlines.
PMID- 10687682
TI - Modified impulse method for the measurement of the frequency response of acoustic
filters to weakly nonlinear transient excitations
AB - In this paper, a modified impulse method is proposed which allows the
determination of the influence of the excitation characteristics on acoustic
filter performance. Issues related to nonlinear propagation, namely wave
steepening and wave interactions, have been addressed in an approximate way,
validated against one-dimensional unsteady nonlinear flow calculations. The
results obtained for expansion chambers and extended duct resonators indicate
that the amplitude threshold for the onset of nonlinear phenomena is related to
the geometry considered.
PMID- 10687683
TI - Matched-field processing using measured replica fields
AB - An approach for avoiding the problem of environmental uncertainty is tested using
data from the TESPEX experiments. Acoustic data basing is an alternative to the
difficult task of characterizing the environment by performing direct
measurements and solving inverse problems. A source is towed throughout the
region of interest to obtain a database of the acoustic field on an array of
receivers. With this approach, there is no need to determine environmental
parameters or solve the wave equation. Replica fields from an acoustic database
are used to perform environmental source tracking [J. Acoust. Soc. Am. 94, 3335
3341 (1993)], which exploits environmental complexity and source motion.
PMID- 10687684
TI - Predicting acoustic effects of internal waves from the basic climatology of the
world ocean
AB - Internal waves of a given strength will produce acoustic effects that vary from
water mass to water mass. Presented here is a means of predicting the strength of
acoustic fluctuations due to internal waves, given the basic climatology, that
is, measurements of depth, temperature, and salinity of an oceanic region. An
acoustic fluctuation strength parameter F is defined as the ratio of the
fractional potential sound-speed change to the fractional potential-density
change. Here F is calculated at three depth levels (275, 550, and 850 m), on a
one-degree grid of latitude and longitude, using NODC/OCL's World Ocean Atlas
1994. Representative values of F are presented for 15 upper water masses that
range from F = 5 in the North Pacific to F = 34 in the North Atlantic, with a
typical value for most of the upper waters being F = 15. Results for two depth
levels within 12 intermediate water masses range from F = 7 in the North Pacific
to F = 62 in the North Atlantic, with a typical value of F = 20, although there
is considerable variation. In general, F exhibits higher values in the Atlantic
Basin than in the Indian or Pacific, and has a maximum at 550 m. The main use of
F will be the prediction of travel-time fluctuations in acoustic propagation
experiments, which will be proportional to the value of F, given a universal
strength of internal waves.
PMID- 10687685
TI - Long time-base observations of surf noise
AB - A year of surf noise observations in the very near shore region of La Jolla
Shores beach are presented. Ambient sound levels and surface wave height were
recorded for 9 min every hour from July 1997 through June 1998 at a monitoring
station located 360 m seaward of the beach in 8-m deep water. Sound segments that
were dominated by the noise from breaking surf formed the basis of a correlation
analysis between surf noise level and wave height, wave period, wind speed, and
mean water depth. The analysis shows that surf noise is primarily determined by
wave height, and scales approximately with the wave height squared. The surface
wave energy flux onto the beach also scales with wave height squared, leading to
the conclusion that the conversion of the mechanical energy of the surface wave
field into noise energy is approximately constant. In fact, the ratio of noise
energy to surface wave energy flux varies by up to a factor of 3 over the range
of energy fluxes considered (100-3000 W per m).
PMID- 10687686
TI - Collective oscillations of fresh and salt water bubble plumes
AB - Bubble plumes of various void fractions and sizes were produced by varying the
flow velocity of a water jet impinging normally on a water surface. The bubbles
entrained at the surface were carried downwards by the fluid flow to depths
ranging from 33 to 65 cm, and formed roughly cylindrical plumes with diameters
ranging from 12 to 27 cm. The acoustic emissions from the plumes were recorded
onto digital audio tape using a hydrophone placed outside the cloud at distances
ranging from 50 cm to 16.0 m. Closeup video images of the individual bubbles
within the plume were also taken in order to gain knowledge of the bubble size
distributions. The experiments were performed in both fresh-water and salt-water
environments. The fresh-water clouds emitted sounds with a modal structure that
was significantly different from that produced by the salt-water clouds.
Furthermore, the smaller bubbles present in the salt-water clouds have a
fundamental effect on the amplification of turbulence noise, generating sound at
significant levels for frequencies up to several hundred Hertz.
PMID- 10687687
TI - Ultrasonic absorption in critical binary mixture of perfluoromethylcyclohexane
and carbon tetrachloride
AB - The results of ultrasonic absorption and velocity measurements for the system
perfluoromethylcyclohexane-carbon tetrachloride are presented. In addition,
viscosity measurements were made. Ultrasonic absorption at 5, 7, 10, 15, 21, and
25 MHz, above critical temperature Tc, is analyzed using the dynamic scaling
theory of Ferrell and Bhattacharjee. The values of alpha/f2 vs f-1.06 show a good
agreement with the theory. The experimental values of alpha/alpha c for the
binary mixture are compared to the scaling function F(omega*).
PMID- 10687688
TI - Comparison between the dispersion curves calculated in complex frequency and the
minima of the reflection coefficients for an embedded layer
AB - Analytical solutions of Lamb functions for symmetric and antisymmetric
elastodynamic modes propagating within a solid layer embedded in an infinite
medium are presented. Alternative theoretical analyses of such modes are
performed, first in terms of the usual approach of harmonic heterogeneous plane
waves (real frequency and complex slowness) and then in terms of transient
homogeneous plane waves (complex frequency and real slowness). An example
structure of a 0.1-mm-thick "alpha case" (an oxygen-rich phase of titanium that
is relatively stiff) plate embedded in titanium is used for the study. A large
difference between the usual dispersion curves calculated in real frequency and
complex slowness and those calculated in complex frequency and real slowness is
shown. Thus the choice between a spatial and a temporal parameter to describe the
imaginary part of the guided waves is shown to be significant. The minima and the
zeros of the longitudinal and shear plane-wave reflection coefficients are
calculated and are compared with the dispersion curves. It is found that they do
not match with the dispersion curves for complex slowness, but they do agree
quite well with the dispersion curves for complex frequency. This implies that
the complex frequency approach is better suited for the comparison of the modal
properties with near-field reflection measurements.
PMID- 10687689
TI - Measurement of acoustic dispersion using both transmitted and reflected pulses
AB - Traditional broadband transmission method for measuring acoustic dispersion
requires the measurements of the sound speed in water, the thickness of the
specimen, and the phase spectra of two transmitted ultrasound pulses. When the
sound speed in the specimen is significantly different from that in water, the
overall uncertainty of the dispersion measurement is generally dominated by the
uncertainty of the thickness measurement. In this paper, a new water immersion
method for measuring dispersion is proposed which eliminates the need for
thickness measurement and the associated uncertainty. In addition to recording
the two transmitted pulses, the new method requires recording two reflected
pulses, one from the front surface and one from the back surface of the specimen.
The phase velocity as well as the thickness of the specimen can be determined
from the phase spectra of the four pulses. Theoretical analysis and experimental
results from three specimens demonstrate the advantages of this new method.
PMID- 10687690
TI - The effect of gas loading on the RUS spectra of spheres
AB - Resonant Ultrasound Spectroscopy (RUS) of a spherical sample in a pressurizing
gas atmosphere was investigated experimentally and theoretically. Measurements
were made on a fused silica sphere in He, Ar, and N2 gases up to pressures of 120
bar. The pressure-dependent shift in the resonant frequency, delta f, and the Q
factor were measured for the S00, S11, and T02 modes. A theoretical model based
on acoustic radiation impedance was used to calculate delta f and the radiation
resistance component, Qr, of the Q-factor. Agreement between theory and
experiment was good for Qr, but there were discrepancies for delta f. It was
found that the theoretical delta f due to gas-loading effects associated with
acoustic radiation was very small and consistent with the observed dependence on
pressure and gas species for the T02 mode but not for the S00 and S11 modes. We
conclude that the T02 mode is the most reliable of these modes to use in
measuring third-order elastic constants by RUS.
PMID- 10687691
TI - Using phase space diagrams to interpret multiple frequency drive sonoluminescence
AB - The recent experimental results of J. Holzfuss, M. Ruggeberg, and R. Mettin
[Phys. Rev. Lett. 81, 1961 (1998)] in which a second harmonic drive system was
used to generate sonoluminescence (SL) have been analyzed in the context of the
dissociation hypothesis (DH) of D. Lohse and S. Hilgenfeldt [J. Chem. Phys. 107,
6986 (1997)]. The second harmonic introduces two more variables that are under
experimental control: a phase and an additional pressure term to the acoustic
drive pressure. Diffusive equilibrium curves for a fixed gas concentration were
calculated as was the Mach criterion. A phase space diagram was constructed to
permit the prediction of regions of stable SL, unstable SL, stable non-SL, and
unstable non-SL. These were compared to Holzfuss' experimental observations, and
excellent quantitative agreement was seen. The results provide further evidence
that the underlying assumptions of DH are sound. They also indicate the utility
of DH for determining appropriate experimental conditions to achieve SL and for
optimizing an experimental system.
PMID- 10687692
TI - Use of electrodynamic drivers in thermoacoustic refrigerators
AB - Some issues involved in matching electrodynamic drivers to thermoacoustic
refrigerators are examined using an equivalent circuit model. Conclusions are
that the driver should be chosen to have a large product (Bl)2/(ReRm); the
suspension stiffness should be chosen to make the combined impedance of the
mechanical and acoustical parts of the system entirely real at the operating
frequency; and the piston area should be selected to maximize electroacoustic
efficiency, or other desired parameter, by matching the acoustic load to the
optimum mechanical load for the particular driver. Alternately, if the piston
area is fixed, the operating frequency can be adjusted to make this same match.
PMID- 10687693
TI - Acoustical performance of an electrostrictive polymer film loudspeaker
AB - A new type of loudspeaker that generates sound by means of the electrostrictive
response of a thin polymer film is described. Electrostrictive polymer film (EPF)
loudspeakers are constructed with inexpensive, lightweight materials and have a
very low profile. The films are typically silicone and are coated with compliant
electrodes to allow large film deformations. Acoustical frequency response
measurements from 5 x 5 cm (planar dimensions) prototype EPF loudspeakers are
presented. Measurements of harmonic distortion are also shown, along with results
demonstrating reduced harmonic distortion achieved with square-root wave shaping.
Applications of EPF loudspeakers include active noise control and general-purpose
flat-panel loudspeakers.
PMID- 10687694
TI - Hybrid tool for quickly estimating the radiated acoustic power from a vibrating
structure in a multiple-source environment
AB - This paper presents a new hybrid method for predicting overestimating and
underestimating indicators of the acoustic power radiated by a vibrating surface
even in the presence of other surrounding acoustic sources. This method is
applicable to plates or low curvature surfaces radiating in open acoustic fields.
The method is hybrid in the sense that the vibration field is measured and the
parietal pressure field is predicted considering two extreme academic cases
"baffled" and "unbaffled." Many simplifications are made and justified in order
to save running time. The method is successfully validated in comparison with
experimental results on both laboratory and real life structures. This method has
led to a quick tool, allowing one to obtain a good approximation of the radiated
power in a few minutes. It provides a natural extension of a classical analyzer
for vibroacoustics engineering.
PMID- 10687695
TI - Rotating machinery dynamics simulation. I. Rigid systems with ball bearing
nonlinearities and outer ring ovality under rotating unbalance excitation
AB - The radial clearance in rolling bearing systems, required to compensate for
dimensional changes associated with thermal expansion of the various parts during
operation, may cause dimensional attrition and comprise bearing life, if unloaded
operation occurs and balls skid [D. Childs and D. Moyer, ASME J. Eng. Gas Turb.
Power 107, 152-159 (1985)]. Also, it can cause jumps in the response to unbalance
excitation. These undesirable effects may be eliminated by introducing two or
more loops into one of the bearing races so that at least two points of the ring
circumference provide a positive zero clearance [D. Childs, Handbook of
Rotordynamics, edited by F. Ehrich (McGraw-Hill, NY, 1992)]. The deviation of the
outer ring with two loops, known as ovality, is one of the bearing distributed
defects. Although this class of imperfections has received much work, none of the
available studies has simulated the effect of the outer ring ovality on the
dynamic behavior of rotating machinery under rotating unbalance with
consideration of ball bearing nonlinearities, shaft elasticity, and speed of
rotation. To fill this gap, the equations of motion of a rotor-ball bearing
system are formulated using finite-elements (FE) discretization and Lagrange's
equations. The analyses are specialized to a rigid-rotor system, by retaining the
rigid body modes only in the FE solution. Samples of the results are presented in
both time domain and frequency domain for a system with and without outer ring
ovality. It is found that with ideal bearings (no ovality), the vibration
spectrum is qualitatively and quantitatively the same in both the horizontal and
vertical directions. When the ring ovality is introduced, however, the spectrum
in both orthogonal planes is no longer similar. And magnitude of the bearing load
has increased in the form of repeated random impacts, between balls and rings, in
the horizontal direction (direction of maximum clearance) compared to a
continuous contact along the vertical direction (direction of positive zero
clearance). This underlines the importance of the vibration measuring probe's
direction, with respect to the outer ring axes, to capture impact-induced
vibrations. Moreover, when the harmonic excitation is increased for a system with
ideal bearings, the spectral peaks above forcing frequency have shifted to a
higher-frequency region, indicating some sort of a hard spring mechanism inherent
in the system. Another observation, is that for the same external excitation,
vibration amplitude at forcing frequency in the bearing force spectrum is the
same for systems with or without outer ring ovality.
PMID- 10687696
TI - Reverberation time and maximum background-noise level for classrooms from a
comparative study of speech intelligibility metrics.
AB - Speech intelligibility metrics that take into account sound reflections in the
room and the background noise have been compared, assuming diffuse sound field.
Under this assumption, sound decays exponentially with a decay constant inversely
proportional to reverberation time. Analytical formulas were obtained for each
speech intelligibility metric providing a common basis for comparison. These
formulas were applied to three sizes of rectangular classrooms. The sound source
was the human voice without amplification, and background noise was taken into
account by a noise-to-signal ratio. Correlations between the metrics and speech
intelligibility are presented and applied to the classrooms under study.
Relationships between some speech intelligibility metrics were also established.
For each noise-to-signal ratio, the value of each speech intelligibility metric
is maximized for a specific reverberation time. For quiet classrooms, the
reverberation time that maximizes these speech intelligibility metrics is between
0.1 and 0.3 s. Speech intelligibility of 100% is possible with reverberation
times up to 0.4-0.5 s and this is the recommended range. The study suggests
"ideal" and "acceptable" maximum background-noise level for classrooms of 25 and
20 dB, respectively, below the voice level at 1 m in front of the talker.
PMID- 10687697
TI - Broadband control of plate radiation using a piezoelectric, double-amplifier
active-skin and structural acoustic sensing
AB - The potential of a piezoelectric, double-amplifier active-skin with structural
acoustic sensing (SAS) is demonstrated for the reduction of broadband acoustic
radiation from a clamped, aluminum plate. The active-skin is a continuous
covering of the vibrating portions of the plate with active, independently
controllable piezoelectric, double-amplifier elements and is designed to affect
control by altering the continuous structural radiation impedance rather than
structural vibration. In simulation, acoustic models are sought for the primary
and secondary sources that incorporate finite element methods. Simulation
indicates that a total radiated power attenuation in excess of 10 dB may be
achieved between 250 and 750 Hz with microphone error sensing, while under SAS
the radiated power is reduced by nearly 8 dB in the same frequency range. In
experiment, the adaptive feed forward filtered-x LMS (least mean square)
algorithm, implemented on a Texas Instruments C40 DSP, was used in conjunction
with the 6I6O control system. With microphone error sensing, 11.8-dB attenuation
was achieved in the overall radiated power between 175 and 600 Hz, while
inclusion of SAS resulted in a 7.3-dB overall power reduction in this frequency
band.
PMID- 10687698
TI - Performance of some sparseness criterion blind deconvolution methods in the
presence of noise
AB - A comparison of the spareseness (simplicity) norm criterion blind deconvolution
methods of Cabrelli and Wiggins is made in order to ascertain relative
performance for underwater acoustic transient source signal estimation,
especially in the presence of noise. Both methods perform well at high signal-to
noise ratios, producing source estimates that are significant improvements over
the original received signal for classification purposes. At moderate and lower
SNRs, the Cabrelli method tends to generate results that are superior to the
Wiggins method. This is especially true for a damped sinusoid transient source,
for which the Wiggins method fails completely at lower SNRs, while the Cabrelli
method can still produce good source estimates.
PMID- 10687699
TI - A macro-mechanical model of the guinea pig cochlea with realistic parameters.
AB - The post-mortem transfer function of the cochlea of the guinea pig was compared
to the transfer function generated by a model with parameters derived from
physical measurements of the guinea pig cochlea. Both the formulation and
parameters of the model were carefully chosen to be realistic using evidence from
published measurements. The fit between the transfer function of the model and
recent mechanical measurements of the passive guinea pig cochlear response was
good, with a root mean square ratio of 6.3 dB in amplitude and 0.33 pi rad in
phase. The model was used to explore the effect of cochlear partition mode factor
and duct geometry upon the mechanical response of the cochlea. Possible
inadequacies of the model which could explain the remaining differences between
the output of the model and measurements are discussed.
PMID- 10687700
TI - Stochastic properties of cat auditory nerve responses to electric and acoustic
stimuli and application to intensity discrimination.
AB - Statistical properties of electrically stimulated (ES) and acoustically
stimulated (AS) auditory nerve fiber responses were assessed in undeafened and
short-term deafened cats, and a detection theory approach was used to determine
fibers' abilities to signal intensity changes. ES responses differed from AS
responses in several ways. Rate-level functions were an order of magnitude
steeper, and discharge rate normally saturated at the stimulus pulse rate.
Dynamic ranges were typically 1-4 dB for 200 pps signals, as compared with 15-30
dB for AS signals at CF, and they increased with pulse rate without improving
threshold or changing absolute rate-level function slopes. For both ES and AS
responses, variability of spike counts elicited by repeated trials increased with
level in accord with Poisson-process predictions until the discharge rate
exceeded 20-40 spikes/s. AS variability continued increasing monotonically at
higher discharge rates, but more slowly. In contrast, maximum ES variability was
usually attained at 100 spikes/s, and at higher discharge rates variability
reached a plateau that was either maintained or decreased slightly until
discharge rate approached the stimulus pulse rate. Variability then decreased to
zero as each pulse elicited a spike. Increasing pulse rate did not substantially
affect variability for rates up to 800 pps; rather, higher pulse rates simply
extended the plateau region. Spike count variability was unusually high for some
ES fibers. This was traced to response nonstationarities that stemmed from two
sources, namely level-dependent fluctuations in excitability that occurred at 1-3
s intervals and, for responses to high-rate, high-intensity signals, fatigue that
arose when fibers discharged at their maximum possible rates. Intensity
discrimination performance was assessed using spike count as the decision
variable in a simulated 2IFC task. Neurometric functions (percent correct versus
intensity difference) were obtained at several levels of the standard (I), and
the intensity difference (delta I) necessary for 70% correct responses was
estimated. AS Weber fractions (10 log delta I/I) averaged +0.2 dB (delta IdB =
3.1 dB) for 50 ms tones at CF. ES Weber fractions averaged -12.8 dB (delta IdB =
0.23 dB) for 50 ms, 200 pps signals, and performance was approximately constant
between 100 and 1000 pps. Intensity discrimination by single cells in ES
conditions paralleled human psychophysical performance for similar signals. High
ES sensitivity to intensity changes arose primarily from steeper rate-level
functions and secondarily from reduced spike count variability.
PMID- 10687701
TI - Temporal integration in the presence of off-frequency maskers.
AB - Temporal integration was measured at a relatively low and a relatively high
signal frequency under conditions of off-frequency masking. The masker was
typically gated for 300 ms, and the signal was presented 70 ms after masker
onset. In experiment 1, the signal frequency was 500 or 2000 Hz. Temporal
integration was measured in quiet and in the presence of a masker whose frequency
was lower or higher than the signal frequency. In all listening situations, there
was less integration at 2000 Hz than at 500 Hz. This effect of frequency was
particularly dramatic in the presence of a lower frequency masker, where there
was almost no integration at 2000 Hz. Experiment 2 showed that this dramatic
effect of frequency cannot be understood in terms of the underlying psychometric
functions. Experiment 3 measured temporal integration at 750 and 2000 Hz for a
large number of masker-signal frequency separations for both a tonal and a noise
masker, and in conditions where the masker was gated or continuous. The results
with the gated tonal masker largely confirmed the results of experiment 1. The
results with the continuous tonal masker and the gated or continuous noise
masker, however, were quite different. In those cases, the amount of temporal
integration at both signal frequencies was more or less independent of the masker
signal separation; the masked temporal integration was nearly equal to the
integration in quiet. Thus based on the conditions evaluated here, off-frequency
masked temporal integration differs substantially from integration in quiet only
for gated tonal maskers located considerably lower in frequency than the signal.
It is unclear how to account for this finding, although it may be related to
attentional factors.
PMID- 10687702
TI - Psychophysical correlates of contralateral efferent suppression. I. The role of
the medial olivocochlear system in "central masking" in nonhuman primates.
AB - An extensive physiological literature, including experimental and clinical
studies in humans, demonstrates that activation of the medial olivocochlear (MOC)
efferent system, by either contralateral sound or electrical stimulation, can
produce significant alterations in cochlear function and suggests a role for the
MOC system in influencing the auditory behavior of binaural hearing. The present
data are from psychophysical studies in nonhuman primates which seek to determine
if the noted physiological changes in response to contralateral acoustic
stimulation have a perceptual counterpart. Four juvenile Japanese macaques were
trained to respond to the presence of 1-s sinusoids, presented to the test ear,
in an operant reinforcement paradigm. Thresholds were compared for frequencies
ranging from 1.0 to 4.0 kHz in quiet, with thresholds measured when continuous,
two octave-band noise, centered on the test tone frequency, was presented in the
contralateral ear. Contralateral noise was presented at levels of 10-60 dB above
detection threshold for the test-tone frequency. While some variability was
evident across subjects, both in the frequency distribution and magnitude (as a
function of contralateral noise level), all subjects exhibited an increase, or
suppression of thresholds in the presence of contralateral noise. On average,
thresholds increased systematically with contralateral noise level, to a peak of
7 dB. In one subject, the threshold increase seen with contralateral noise was
significantly reduced when the MOC was surgically sectioned on the floor of the
IVth ventricle. The characteristics of the measured shifts in behavioral
thresholds, in the presence of contralateral noise reported here, are
qualitatively and quantitatively similar to both efferent physiological
suppression effects and psychophysical central masking threshold shifts which
have been reported previously. These data suggest that at least some aspects of
"central masking" are efferent-mediated peripheral processes, and that the term
"central masking" may be incorrect.
PMID- 10687703
TI - The effects of frequency region and level on the temporal modulation transfer
function.
AB - Temporal modulation transfer functions (TMTFs) were measured using narrow-band AM
and QFM noises with upper spectral edges from 0.6 to 4.8 kHz, and spectrum levels
of 10 and 40 dB SPL. The cutoff frequency of the TMTF increases as the upper
spectral edge is increased up to 4.8 kHz at low levels, and is constant at higher
levels. Sensitivity increases with bandwidth if frequency region is constant. In
a second experiment, these results were compared to predictions of a model
incorporating peripheral and central limitations to modulation detection. To
obtain an estimate of peripheral filtering, frequency selectivity was measured
using the notched-noise method, with probe frequencies and levels chosen to
parallel those in the first experiment. The TMTF data were then predicted using
the model. Predicted cutoff frequencies as a function of the upper spectral edge
of the test stimulus were lower than but parallel to those of the subjects at the
lower stimulus level. The model predicted only a slight increase in cutoff
frequency with level, and thus predicted an increase in cutoff frequency with
frequency region at the higher level as well, in contrast to the measured data.
These results suggest that there are peripheral and central limitations to
temporal resolution, but the psychoacoustically derived auditory filter may be
only an indirect measure of peripheral filtering, and/or a more complex model may
be needed.
PMID- 10687704
TI - On the relative influence of individual harmonics on pitch judgment.
AB - Spectral weighting functions were estimated in a pitch-comparison task to assess
the relative influence of individual harmonics on listeners' pitch judgment. The
stimuli were quasi-harmonic complex tones composed of the first 12 components,
with fundamental frequencies ranging from 100 to 800 Hz. On each stimulus
presentation the frequency of each harmonic was randomly jittered by a small
amount. The perceptual weight for each harmonic was calculated as the correlation
coefficient between the binary responses of the listener and the frequency
jitters for that harmonic. Although in general the present results conform to
previous ones showing the predominant role of several low-ranked harmonics,
discrepancies exist in details. Contrary to some previous reports that the
dominant harmonics were of fixed harmonic ranks regardless of their frequencies,
the current results showed that the dominant harmonics were best described as
close to a fixed absolute frequency of 600 Hz.
PMID- 10687705
TI - Extracting spectral envelopes: formant frequency matching between sounds on
different and modulated fundamental frequencies.
AB - The four experiments reported here measure listeners' accuracy and consistency in
adjusting a formant frequency of one- or two-formant complex sounds to match the
timbre of a target sound. By presenting the target and the adjustable sound on
different fundamental frequencies, listeners are prevented from performing the
task by comparing the absolute or relative levels of resolved spectral
components. Experiment 1 uses two-formant vowellike sounds. When the two sounds
have the same F0, the variability of matches (within-subject standard deviation)
for either the first or the second formant is around 1%-3%, which is comparable
to existing data on formant frequency discrimination thresholds. With a
difference in F0, variability increases to around 8% for first-formant matches,
but to only about 4% for second-formant matches. Experiment 2 uses sounds with a
single formant at 1100 or 1200 Hz with both sounds on either low or high
fundamental frequencies. The increase in variability produced by a difference in
F0 is greater for high F0's (where the harmonics close to the formant peak are
resolved) than it is for low F0's (where they are unresolved). Listeners also
showed systematic errors in their mean matches to sounds with different high
F0's. The direction of the systematic errors was towards the most intense
harmonic. Experiments 3 and 4 showed that introduction of a vibratolike frequency
modulation (FM) on F0 reduces the variability of matches, but does not reduce the
systematic error. The experiments demonstrate, for the specific frequencies and
FM used, that there is a perceptual cost to interpolating a spectral envelope
across resolved harmonics.
PMID- 10687706
TI - Effectiveness of spatial cues, prosody, and talker characteristics in selective
attention.
AB - The three experiments reported here compare the effectiveness of natural prosodic
and vocal-tract size cues at overcoming spatial cues in selective attention.
Listeners heard two simultaneous sentences and decided which of two simultaneous
target words came from the attended sentence. Experiment 1 used sentences that
had natural differences in pitch and in level caused by a change in the location
of the main sentence stress. The sentences' pitch contours were moved apart or
together in order to separate out effects due to pitch and those due to other
prosodic factors such as intensity. Both pitch and the other prosodic factors had
an influence on which target word was reported, but the effects were not strong
enough to override the spatial difference produced by an interaural time
difference of +/- 91 microseconds. In experiment 2, a large (+/- 15%) difference
in apparent vocal-tract size between the speakers of the two sentences had an
additional and strong effect, which, in conjunction with the original prosodic
differences overrode an interaural time difference of +/- 181 microseconds.
Experiment 3 showed that vocal-tract size differences of +/- 4% or less had no
detectable effect. Overall, the results show that prosodic and vocal-tract size
cues can override spatial cues in determining which target word belongs in an
attended sentence.
PMID- 10687707
TI - Spectral characterization of jitter, shimmer, and additive noise in synthetically
generated voice signals.
AB - Alteration of the harmonic structure in voice source spectra, taken over at least
two periods of the waveform, may occur due to the presence of fundamental
frequency (f0) perturbation, amplitude perturbation, additive noise, or changes
within the glottal source signal itself. In order to make accurate inferences
regarding glottal-flow dynamics or perceptual evaluations based on spectral
measurements taken from the acoustic speech waveform, investigation of the
spectral features of each aperiodic component is required. Based on a heuristic
development involving a consideration of the partial sum of the Fourier series
taken for two periods of a jittered, shimmered, and (additive, random) noise
contaminated signal, the corresponding spectral characteristics are hypothesized.
Subsequent to this, the Fourier series coefficients are calculated for the two
periods in order to test the hypotheses. Definite spectral differences are found
for each aperiodic component; based on these findings differential quantitative
spectral measurements are suggested. Further supportive evidence is obtained
through use of Fourier transform and periodogram-averaged calculations. The
analysis is carried out on synthetically generated glottal-pulse waveforms and on
radiated speech waveforms. A discussion of the results is given in terms of voice
aperiodicity in general and in terms of their implication for future studies
involving human voice signals.
PMID- 10687708
TI - Quantitative assessment of second language learners' fluency by means of
automatic speech recognition technology.
AB - To determine whether expert fluency ratings of read speech can be predicted on
the basis of automatically calculated temporal measures of speech quality, an
experiment was conducted with read speech of 20 native and 60 non-native speakers
of Dutch. The speech material was scored for fluency by nine experts and was then
analyzed by means of an automatic speech recognizer in terms of quantitative
measures such as speech rate, articulation rate, number and length of pauses,
number of dysfluencies, mean length of runs, and phonation/time ratio. The
results show that expert ratings of fluency in read speech are reliable
(Cronbach's alpha varies between 0.90 and 0.96) and that these ratings can be
predicted on the basis of quantitative measures: for six automatic measures the
magnitude of the correlations with the fluency scores varies between 0.81 and
0.93. Rate of speech appears to be the best predictor: correlations vary between
0.90 and 0.93. Two other important determinants of reading fluency are the rate
at which speakers articulate the sounds and the number of pauses they make.
Apparently, rate of speech is such a good predictor of perceived fluency because
it incorporates these two aspects.
PMID- 10687709
TI - The recognition of isolated words and words in sentences: individual variability
in the use of sentence context.
AB - Estimates of the ability to make use of sentence context in 34 postlingually
hearing-impaired (HI) individuals were obtained using formulas developed by
Boothroyd and Nittrouer [Boothroyd and Nittrouer, J. Acoust. Sco. Am. 84, 101-114
(1988)] which relate scores for isolated words to words in meaningful sentences.
Sentence materials were constructed by concatenating digitized productions of
isolated words to ensure physical equivalence among the test items in the two
conditions. Isolated words and words in sentences were tested at three levels of
intelligibility (targeting 29%, 50%, and 79% correct). Thus, for each subject,
three estimates of context ability, or k factors, were obtained. In addition,
auditory, visual, and auditory-visual sentence recognition was evaluated using
natural productions of sentence materials. Two main questions were addressed: (1)
Is context ability constant for speech materials produced with different degrees
of clarity? and (2) What are the relations between individual estimates of k and
sentence recognition as a function of presentation modality? Results showed that
estimates of k were not constant across different levels of intelligibility: k
was greater for the more degraded condition relative to conditions of higher word
intelligibility. Estimates of k also were influenced strongly by the test order
of isolated words and words in sentences. That is, prior exposure to words in
sentences improved later recognition of the same words when presented in
isolation (and vice versa), even though the 1500 key words comprising the test
materials were presented under degraded (filtered) conditions without feedback.
The impact of this order effect was to reduce individual estimates of k for
subjects exposed to sentence materials first and to increase estimates of k for
subjects exposed to isolated words first. Finally, significant relationships were
found between individual k scores and sentence recognition scores in all three
presentation modalities, suggesting that k is a useful measure of individual
differences in the ability to use sentence context.
PMID- 10687710
TI - Suprasegmental and segmental timing models in Mandarin Chinese and American
English.
AB - This paper formalizes and tests two key assumptions of the concept of
suprasegmental timing: segmental independence and suprasegmental mediation.
Segmental independence holds that the duration of a suprasegmental unit such as a
syllable or foot is only minimally dependent on its segments. Suprasegmental
mediation states that the duration of a segment is determined by the duration of
its suprasegmental unit and its identity, but not directly by the specific
prosodic context responsible for suprasegmental unit duration. Both assumptions
are made by various versions of the isochrony hypothesis [I. Lehiste, J.
Phonetics 5, 253-263 (1977)], and by the syllable timing hypothesis [W. Campbell,
Speech Commun. 9, 57-62 (1990)]. The validity of these assumptions was studied
using the syllable as suprasegmental unit in American English and Mandarin
Chinese. To avoid unnatural timing patterns that might be induced when reading
carrier phrase material, meaningful, nonrepetitive sentences were used with a
wide range of lengths. Segmental independence was tested by measuring how the
average duration of a syllable in a fixed prosodic context depends on its
segmental composition. A strong association was found; in many cases the increase
in average syllabic duration when one segment was substituted for another (e.g.,
bin versus pin) was the same as the difference in average duration between the
two segments (i.e., [b] versus [p]). Thus, the [i] and [n] were not compressed to
make room for the longer [p], which is inconsistent with segmental independence.
Syllabic mediation was tested by measuring which locations in a syllable are most
strongly affected by various contextual factors, including phrasal position,
within-word position, tone, and lexical stress. Systematic differences were found
between these factors in terms of the intrasyllabic locus of maximal effect.
These and earlier results obtained by van Son and van Santen [R. J. J. H van Son
and J. P. H. van Santen, "Modeling the interaction between factors affecting
consonant duration," Proceedings Eurospeech-97, 1997, pp. 319-322] showing a
three-way interaction between consonantal identity (coronals vs labials), within
word position of the syllable, and stress of surrounding vowels, imply that
segmental duration cannot be predicted by compressing or elongating segments to
fit into a predetermined syllabic time interval. In conclusion, while there is
little doubt that suprasegmental units play important predictive and explanatory
roles as phonological units, the concept of suprasegmental timing is less
promising.
PMID- 10687711
TI - Anisotropy of ultrasonic propagation and scattering properties in fresh rat
skeletal muscle in vitro.
AB - The anisotropy of frequency-dependent backscatter coefficient, attenuation, and
speed of sound is assessed in fresh rat skeletal muscle within 5 h post-mortem.
Excised rat semimembranosus and soleus muscles are measured in 37 degrees C
Tyrode solution, with the muscle fibers at 90 degrees and 45 degrees orientations
to the incident sound beam. Reflected and through transmission signals from
either a 6- or 10-MHz focused transducer give frequency dependent information in
the 4-14 MHz range. The attenuation coefficient in each muscle is consistently a
factor of 2.0 +/- 0.4 lower for propagation perpendicular to the fibers than at
45 degrees, whereas speed of sound shows a much milder anisotropy, and is
slightly faster for the 90 degrees orientation. The largest anisotropy is seen in
the backscatter coefficient, most notably in the semimembranosus where the
magnitude at 90 degrees is over an order of magnitude greater than at 45 degrees,
with the frequency dependence in both cases giving a power law between 1.5 and
2.0.
PMID- 10687713
TI - C-scan imaging in molten zinc by focused ultrasonic waves
PMID- 10687712
TI - Spectral cues and perception of the vertical position of targets by the big brown
bat, Eptesicus fuscus.
AB - Big brown bats (Eptesicus fuscus) were trained to discriminate between vertical
angles subtended by paired beads suspended from fishing line. Bats were rewarded
for choosing the smaller of the two angles presented. The difference between the
angles was changed systematically using a transformed up-down procedure and the
bats' ability to detect the difference was measured at different vertical
locations. When the beads were centered at +20 degrees (above the horizon), at 0
degree (the horizon), and at -20 degrees (below the horizon), vertical angle
acuity (VAA) was maintained between 2.9 degrees and 4.1 degrees. At more extreme
vertical positions both bats showed loss of acuity; when the beads were centered
around -40 degrees, VAA was 6.7 degrees or 8.3 degrees and at +40, VAA was worse
than 21 degrees (the largest difference tested). When the tragi of both ears were
bent down and glued to the side of the face, bats showed severe loss of acuity
for beads centered at -20 degrees (VAA 18.3 degrees and 20.1 degrees), but
maintained their angle acuity for beads centered at +20 degrees (VAA 3.8 degrees
and 4.9 degrees). The results are consistent with the spectral cues created by
the filtering of the external ear.
PMID- 10687714
TI - Coupling of velocity dispersion curves of leaky Lamb waves on a fluid-loaded
plate
PMID- 10687716
TI - On a numerical truncation approximation algorithm for transfer matrix method
PMID- 10687715
TI - Contribution to the hydroacoustic ocean monitoring of the UN Test Ban Treaty;
signal classification by an autonomous buoy system
PMID- 10687717
TI - Performance limits of the broadband generalized sidelobe cancelling structure in
an isotropic noise field
PMID- 10687718
TI - Echo suppression in the horizontal and median sagittal planes
PMID- 10687719
TI - A speech corpus for multitalker communications research.
PMID- 10687720
TI - Directional hearing is only weakly dependent on the rise time of acoustic
stimuli.
PMID- 10687721
TI - Variability in the characterization of the headphone transfer-function.
PMID- 10687722
TI - Acoustical imaging through a multiple scattering medium using a time-reversal
mirror.
AB - Acoustical imaging is based on the ability to focus an acoustic beam inside the
zone of interest. This remains an issue through a high-order multiple scattering
medium because the electronic delay lines that enable one to focus through a
multiple scattering medium are a priori unknown. Using time-reversal principles,
we show that images can be obtained through a very disordered medium.
Surprisingly, the images are better than those obtained in a homogeneous medium
with a classical imaging device.
PMID- 10687723
TI - Acute lymphoblastic leukemia in children.
AB - As the overall long-term event-free survival rate in children with acute
lymphoblastic leukemia approaches 80%, emphasis is being placed on risk-directed
therapy so that patients are neither overtreated nor undertreated. It has become
apparent that a risk assignment system based on primary genetic abnormalities is
inadequate by itself. For example, leukemias with the MLL-AF4 or BCR-ABL fusion
gene are, in fact, heterogeneous diseases. Many require allogeneic hematopoietic
stem-cell transplantation; some, if the patient is of favorable age and has a low
presenting leukocyte count, can be cured with chemotherapy alone. Measurement of
early responses to therapy and extent of minimal residual disease can greatly
improve the accuracy of risk assessment. Consideration of the variable effects of
therapy on the prognostic significance of specific genetic abnormalities is also
important. Therefore, TEL-AML1 fusion confers a favorable prognosis in some
protocols of chemotherapy but not in others. Studies to identify genetic
polymorphisms with pharmacokinetic and pharmacodynamic significance promise to
guide further refinement of treatment strategies. This will allow maximization of
anticancer effects without induction of unacceptable toxicity in individual
patients.
PMID- 10687724
TI - Myelodysplasia.
AB - The epidemiology of myelodysplasia, or myelodysplastic syndrome (MDS), is in
evolution. As populations are aging and therapies for cancer are improving, the
frequency of this disease is increasing. Recent population surveys and case
control studies are reviewed. Knowledge of the molecular pathogenesis and
pathophysiology of MDS is advancing at a remarkable pace and new information on
molecular events is presented. The treatment of MDS is complex and highly
individualized. Although many patients are older and may have significant co
morbid disease or poor performance status, there are curative options with
allogeneic transplantation for selected patients. The recent transplant
publications are reviewed. Other investigative treatment approaches, including
the use of new chemotherapy agents, growth factor combinations, and antithymocyte
globulin appear promising and are reviewed.
PMID- 10687725
TI - Update on the biology of chronic lymphocytic leukemia.
AB - An understanding of the molecular biology of B-cell chronic lymphocytic leukemia
(B-CLL) has led to the appreciation that several different B-cell diseases are
represented under this name. Variability in the bcl-2 family of proteins, p53
mutation, or the presence of various chromosomal abnormalities corresponds to
variability of the clinical course of disease and response to therapy.
Differential expression of cell surface adhesion molecules by B-CLL cells have
also been shown to influence clinical outcome, as have the expression of immune
regulatory molecules (eg, CD80, CD40R, CD27 and CD79b). Recent work studying
immunoglobulin-heavy chain gene rearrangement postulates at least two subsets of
B-CLL originating from different stages of B-cell development and following
different clinical courses. The knowledge that B-CLL is the final consequence of
many different molecular perturbations may allow the development of
chemotherapies, immunotherapies, and gene therapies that target the specific
molecular defect in a given case of B-CLL.
PMID- 10687726
TI - Clinical studies of new "biologic" approaches to therapy of acute myeloid
leukemia with monoclonal antibodies and immunoconjugates.
AB - Conventional chemotherapeutic treatments of acute leukemias are often associated
with life-threatening toxic effects due to a lack of specificity for
hematopoietic cells. Monoclonal antibodies and fusion proteins that target
antigens on leukemic blasts are being explored for their antileukemic effects and
as a means of delivering chemotherapy or radiation directly to malignant cells.
This approach might be safer and more effective than current non-specific
chemotherapeutic agents. The cell surface antigens CD33 and CD45 are attractive
targets. Although CD33 is expressed on acute myelocytic leukemic blast cells from
about 90% of patients, normal hematopoietic stem cells lack this antigen, as do
essentially all non-hematopoietic tissues. Anti-CD33 antibodies have been
engineered to selectively target malignant myeloid and immature normal cells
while sparing normal stem cells. Recently, anti-CD33 antibodies have also been
used to deliver radiation or a cytotoxic agent directly to leukemic cells. The
strategy for using CD45 as a target differs from CD33 in that it is expressed not
only by the vast majority of leukemias, but also by normal stem cells. Therefore,
131I-labeled anti-CD45 antibody has been used in combination with conventional
preparative regimens for patients receiving marrow transplantation for acute
leukemia. Because the receptor for granulocyte-macrophage colony-stimulating
factor is expressed by most myeloid leukemias, fusion proteins consisting of
granulocyte-macrophage colony-stimulating factor ligand associated with
diphtheria toxin have been proposed as a means of delivering a toxic agent
directly to leukemic cells. Both unconjugated and conjugated antibodies show
significant promise in the treatment of acute myelocytic leukemia.
PMID- 10687727
TI - Clinical applicability of the evaluation of minimal residual disease in acute
leukemia.
AB - Modern chemotherapy can place most patients with acute leukemia into remission.
Unfortunately, many of these patients will subsequently relapse. The study of
minimal residual disease focuses on the detection of patients destined to relapse
despite appearing to be in clinical remission. In addition, the research has
demonstrated that some patients appear to co-exist with their leukemia for years,
and this suggests a need to re-examine what it means to be "cured" of leukemia.
We await trials testing the intervention of "molecular relapse." Data appear to
be sufficient to launch such trials in diseases such as pediatric acute
lymphoblastic leukemia and the t(1 5;1 7) acute myeloid leukemia.
PMID- 10687728
TI - Update on the management of parathyroid tumors.
AB - Parathyroid tumors are virtually always benign with an estimated incidence of
parathyroid carcinoma causing hyperparathyroidism in only .017% of cases.
Virtually all parathyroid neoplasms, including the rare parathyroid carcinoma,
are functional and discussion of the management of parathyroid tumors is
tantamount to the discussion of primary hyperparathyroidism. The biochemical
diagnostic criteria with rare exception is definitive, and the key issue with
this functional benign endocrine neoplasm is when to recommend operation and how
to ensure optimal results in this curable disease. Patients symptomatic with
nephrolithiasis, significant osteoporosis, bone pain, and in some cases
constitutional symptoms should undergo a surgical therapy. Also, patients with
markedly abnormal laboratory values including a calcium 12.0 mg/dL, or 24-hr
urinary calcium >400 mg/day should be treated surgically. The sestamibi nuclear
medicine scan has become the best tool available for imaging of abnormal
parathyroid glands. This study is positive between 60% and 90% of initial
operations and in between 40% and 70% of reoperations. For multi-gland
parathyroid disease or hyperplasia, the sensitivity of this test is decreased.
Understanding of the ectopic locations of parathyroid adenoma is of utmost
importance in the conduct of the parathyroidectomy. For the rare patients with
parathyroid carcinoma, aggressive surgical resection with en bloc removal of any
adjacent invading structures is the best chance for cure leading to 10-year
survival rates of 49%.
PMID- 10687729
TI - Advances in the management of adrenal tumors.
AB - Adrenal tumors are very common, with the majority being nonhypersecretory and
benign and less than 1% being malignant. Most primary adrenal tumors are
sporadic, but may be associated with other endocrine and familial disorders,
especially pheochromocytoma. All patients with "sporadic" pheochromocytoma should
be screened for MEN-2 and Von Hippel-Lindau disease. As in many endocrine tumors,
there are no uniform definitive histologic criteria to distinguish malignancy,
which is dependent on the clinical behavior of the tumor and is accurately
diagnosed in the presence of adjacent organ invasion, recurrence, or distant
metastasis. Surgery remains the cornerstone and the treatment of choice for
functional and primary malignant adrenal tumors, both for cure and palliation,
with low morbidity and mortality.
PMID- 10687730
TI - Advances in the diagnosis and management of thyroid neoplasms.
AB - Thyroid cancers are still the most common endocrine cancers. They are dominated
by well-differentiated carcinomas, including papillary carcinoma, follicular
carcinoma, and medullary thyroid carcinoma. Diagnosis is based on fine-needle
aspiration cytologic examination. Recently, reverse transcription polymerase
chain reaction for the detection of cancer-specific mRNA was shown to be a useful
adjunct in both initial diagnosis and detection of recurrent disease. In
addition, positron emission tomography has become a valuable tool for staging and
surveillance of thyroid cancer. Given the gradual perfection of surgical
technique and reduction in complication rates, near-total and total thyroidectomy
should be offered to patients with well-differentiated carcinoma. For medullary
thyroid carcinoma, near-total and total thyroidectomy with routine central and
bilateral functional neck dissection are recommended. So far, no effective
treatment exists for anaplastic thyroid carcinoma.
PMID- 10687731
TI - Cytogenetics and cancer.
AB - Techniques based on fluorescence in situ hybridization (FISH) have bridged the
gap between molecular genetics and conventional cytogenetics. Since its
introduction in the late 1980s, advanced FISH-based methods have greatly enhanced
the cytogenetic analysis of hematopoietic and solid tumors and are rapidly
gaining ground in clinical cytogenetic diagnostics. As interest in FISH
technologies has grown, it has inspired an era of new FISH-based technologies
such as multiplex FISH, spectral karyotyping, and comparative genomic
hybridization. In this review, the focus is on the impact of these technologies
in the field of cancer genetics.
PMID- 10687732
TI - Cytosine methylation and human cancer.
AB - Abnormalities of genomic methylation patterns have been attributed a role in
carcinogenesis since the early 1980s, when large-scale demethylation of the
genome was thought be an early event in multistep colorectal carcinogenesis. In
the 1990s, local de novo methylation (with or without global demethylation) at
tumor suppressor loci was held to be involved in silencing of tumor suppressor
genes. The mechanisms that might mediate methylation and demethylation in
carcinogenesis remain obscure, and there are questions as to whether the
methylation changes are a cause or consequence of cellular transformation and
clonal expansion. It is also important to derive a set of defined criteria by
which a tumor suppressor gene can be concluded to have been inactivated by DNA
methylation in a manner that contributes to carcinogenesis.
PMID- 10687733
TI - Telomeres, telomerase, and cancer: life on the edge of genomic stability.
AB - The presence of telomerase activity in most human tumors, but not in many normal
somatic tissues, has raised considerable interest in telomerase as a possible
anticancer therapy. Recent advances in the cloning and characterization of
mammalian telomerase components have paved the way for a more detailed
understanding of the role of telomerase and telomere length maintenance in cell
proliferation. Here, we summarize the most recent biochemical and genetic
evidence suggesting that telomere length maintenance by telomerase is critical to
the proliferative ability of some immortalized mammalian cells in culture and in
vivo.
PMID- 10687734
TI - Aneuploidy and cancer.
AB - Numeric aberrations in chromosomes, referred to as aneuploidy, is commonly
observed in human cancer. Whether aneuploidy is a cause or consequence of cancer
has long been debated. Three lines of evidence now make a compelling case for
aneuploidy being a discrete chromosome mutation event that contributes to
malignant transformation and progression process. First, precise assay of
chromosome aneuploidy in several primary tumors with in situ hybridization and
comparative genomic hybridization techniques have revealed that specific
chromosome aneusomies correlate with distinct tumor phenotypes. Second, aneuploid
tumor cell lines and in vitro transformed rodent cells have been reported to
display an elevated rate of chromosome instability, thereby indicating that
aneuploidy is a dynamic chromosome mutation event associated with transformation
of cells. Third, and most important, a number of mitotic genes regulating
chromosome segregation have been found mutated in human cancer cells, implicating
such mutations in induction of aneuploidy in tumors. Some of these gene
mutations, possibly allowing unequal segregations of chromosomes, also cause
tumorigenic transformation of cells in vitro. In this review, the recent
publications investigating aneuploidy in human cancers, rate of chromosome
instability in aneuploidy tumor cells, and genes implicated in regulating
chromosome segregation found mutated in cancer cells are discussed.
PMID- 10687735
TI - Is angiogenesis inhibition the Holy Grail of cancer therapy?
AB - Over the last several decades, oncology research and cancer treatment have
concentrated primarily on the cancer cells. Unfortunately, despite the intensive
quest to find new and more effective compounds for chemotherapy, the survival
rate of patients has not significantly changed. In 1971 Judah Folkman proposed
that a solid tumor cannot grow without inducing angiogenesis. Intensive search
for molecules blocking the formation of a tumor-nourishing capillary network has
identified several promising agents in experimental models. Some of these
angiogenesis inhibitors are in clinical trials, but a clear statement about the
efficacy cannot be made yet. What are the current trends in angiogenesis
research? What areas should we intensively investigate? Can we find the Holy
Grail of cancer therapy in the years to come in order to stop the ineffable
suffering of millions of cancer patients?
PMID- 10687736
TI - Detection and clinical relevance of micrometastatic cancer cells.
AB - The failure to reduce mortality of epithelial cancer patients is probably a
result of the early dissemination of cancer cells to secondary sites, which is
usually missed by conventional diagnostic procedures used for tumor staging.
Individual carcinoma cells present in regional lymph nodes, blood, or distant
organs (eg, bone marrow) can be detected by sensitive immunologic or molecular
methods. Because the goal of adjuvant therapy is the eradication of occult
micrometastatic tumor cells before metastatic disease becomes clinically evident,
the early detection of micrometastases could identify those patients who might
benefit from adjuvant therapy. In addition, more sensitive methods for detecting
such cells should increase knowledge about the biologic mechanisms of metastasis,
which might improve the diagnosis and treatment of micrometastatic disease. In
this article, the recent developments in sensitive assays used for the detection
of individual micrometastatic cancer cells in patients with epithelial tumors are
reviewed.
PMID- 10687737
TI - Bibliography. Current world literature. Leukemia.
PMID- 10687738
TI - Bibliography. Current World Literature. Endocrine tumors.
PMID- 10687739
TI - Bibliography. Current World Literature. Cancer biology.
PMID- 10687740
TI - Factors affecting disability in patients attending the internal medicine
departments of general hospitals.
AB - The aim of this study was to investigate the effect of sociodemographic factors,
physical factors and mental factors on the physical and social disability of
patients attending outpatient clinics of general hospitals. Physical and
psychiatric morbidity in 1580 consecutive patients attending the internal
medicine department of general hospitals was assessed using a stratified two
stage sampling design method. Of the total, 336 patients completed the second
stage interview composed of Primary Care Version of Composite International
Diagnostic Interview and Groningen Social Disability Schedule to assess
sociodemographic, physical and mental factors. In this study, restricted activity
days, disability days and Brief Disability Questionnaire were used for the
assessment of physical disability, and Groningen Social Disability Schedule was
used for social disability. Sociodemographic, physical and mental factors were
all related to disability. Among sociodemographic factors, unemployment was
associated with physical disability and social disability mildly. Among physical
factors, the severity of physical disease was not associated with disability and
medically explained somatic symptoms were associated with disability.
Furthermore, the mental factor was more strongly associated with physical and
social disability. It could be said that the mental factor is more strongly
associated with physical and social disability than sociodemographic or physical
factors. In addition, even mild mental symptoms not leading to ICD-10 mental
disorders affected disability. From the viewpoint of the patients' burden, it is
important to assess the mental symptoms as well as physical status in outpatient
clinics of internal medicine or primary care.
PMID- 10687741
TI - Mental health problems after stroke.
AB - We investigated the mental health of 47 subjects (30 men, mean age 63.8+/-7.7; 17
women, mean age 68.9+/-8.7) with the 60-item General Health Questionnaire (GHQ).
All the subjects lived at home in a Japanese rural community and were examined
from 2 to 3 years after suffering a stroke. Among the subjects, 18 (38.3%) had
GHQ scores of 17 or more, which indicated a mental health problem (MHP). The
following variables were included in multiple logistic regression analysis: age,
sex (men/women), grade of motor paralysis (no/slight/moderate/severe), side of
motor paralysis (no/left side/right side/both sides: in analysis, we used dummy
variables), paresthesia (no/yes), rehabilitation (need no rehabilitation or
participate in rehabilitation/fail to participate in rehabilitation), social
support (not needed or sufficient/insufficient) and overall physical recovery
(1/2/3: 1 = 67-100, 2 = 34-66, and 3 = 0-33 on a visual analog scale 100 mm long,
100 meaning full recovery). In univariate analysis all variables except age and
sex showed statistically significant associations with MHP. In multivariate
analysis, only one variable, overall physical recovery', had a statistically
independent association with the status of MHP (Odds ratio 4.39, 95% confidence
interval 1.46-13.19). The results of logistic regression analysis indicate that
the presence of an MHP is more strongly dependent upon subjective assessment
about overall physical recovery after stroke than upon physical impairments and
the other psychosocial variables. Therefore, in the community setting, the visual
analog scale of overall physical recovery is considered to be a simple, valid
method for assessing MHP following stroke.
PMID- 10687742
TI - Cultural difference in recognition of facial emotional expression: contrast
between Japanese and American raters.
AB - Using the Japanese and Caucasian Facial Expressions of Emotion (JACFEE) photo
set, the relationship between recognition and intensity ratings of universal
facial expressions of emotions in 123 Japanese undergraduate students was
examined and compared with data reported by American raters. In Japanese raters,
although the intensity was rated as high for some of the poses, their correctness
scores were poor, suggesting a serious misjudgment of the intended emotions as
defined in the JACFEE photo set. Only in Japanese raters were significant
relationships between the intensity scores and the percentage correctness scores
for sadness detected (r = 0.97, P < 0.0001), but no significant relationship was
observed for other emotions. The robust correlation suggests the possibility that
Japanese raters might be more responsive to certain emotional expressions when
they are fully or intensely expressed. It is proposed that the facial emotional
expression paradigm cannot be applied to the psychiatric setting without first
refining for cultural differences.
PMID- 10687743
TI - Attentional processing of emotional information in obsessive-compulsive disorder.
AB - In order to investigate attentional processing of emotional information in
obsessive-compulsive disorder (OCD), 14 patients with OCD and 28 normal control
(NC) subjects were asked to name the background colors of anxiety-relevant,
compulsion-relevant, positive and neutral words (an emotional Stroop color-naming
test). The stimulus words were presented subliminally, and supraliminally. The
time of subliminal presentation for each subject was determined in advance by the
lexical decision task. In the subliminal condition, the delay for anxiety- and
compulsion-relevant words, when compared with neutral words, was greater in OCD
patients, while no difference was found in NC subjects. In the supraliminal
condition, no delay was found for both OCD patients and NC subjects. In other
words, OCD patients were more sensitive to threat information when it could not
be identified with consciousness. Moreover, the present study compared checking
OCD with cleaning OCD in the attentional processing of emotional information. As
a result, it was found that checking OCD patients responded more slowly in naming
the background color of subliminal emotional words than cleaning OCD patients.
The results indicate that OCD patients, especially with checking compulsion, may
have a deficit in automatic processing of threat information.
PMID- 10687744
TI - Apolipoprotein E phenotypes in healthy normal controls and demented subjects with
Alzheimer's disease and vascular dementia in Mie Prefecture of Japan.
AB - In order to clarify the association between apolipoprotein E4 (ApoE4) and the
pathogenesis of Alzheimer's disease (AD), we analyzed the distribution of the
apolipoprotein E (ApoE) phenotypes and the frequency of the apo E alleles
epsilon2, epsilon3, and epsilon4 in Japanese healthy controls (n = 1090, an
average age of 51.2+/-12.6 years) and demented patients (n=103, mean age of
73.6+/-9.2 years). Demented subjects were divided into three subgroups: early
onset AD group (EOAD; n=25, mean age 63.0+/-6.2 years), late-onset AD group
(LOAD; n=33, mean age 79.3+/-5.1 years), and vascular dementia group (VD; n=45,
mean age 75.3+/-8.0 years). The apolipoprotein E phenotype was determined by
isoelectric focusing and immunoblotting. There were no significant differences in
the distribution of the apo E phenotypes by gender or age, and the estimated
frequencies of epsilon2, epsilon3 and epsilon4 were 0.05, 0.86 and 0.09,
respectively, in the normal controls. There was a significant difference in the
distribution of the apo E phenotypes between LOAD and elderly controls aged more
than 65 years (P<0.0001). The distribution of the apo E phenotypes in EOAD was
the same as that in LOAD. The frequency of the epsilon4 allele was significantly
higher in LOAD (0.35, P<0.0001) and EOAD (0.28, P<0.0001) than that in the
control subjects (0.07), but not in VD (0.12, P=0.1630). The present findings
suggest that ApoE4 is related with both EOAD and LOAD, but not with VD, and
support the hypothesis that it is a genetic risk factor of AD.
PMID- 10687745
TI - Precedents of perceived social support: personality and early life experiences.
AB - In order to examine the effects of personality and early life experiences on
perceived social support, a total of 97 young Japanese women were investigated.
Current interpersonal relationships were measured by an interview modified from
Henderson et al.'s Interview Schedule for Social Interaction (ISSI). Personality
was measured by Cloninger et al.'s Temperament and Character Inventory. Early
life experiences at home and outside of home were also identified in the
interview. The number of sources of perceived support was correlated with self
directness, while satisfaction with perceived support was correlated with novelty
seeking and with low harm avoidance. No early life experiences--early loss of a
parent, perceived parenting, childhood abuse experiences, experiences of being
bullied and/or other life events--showed significant correlations with the number
or satisfaction of supportive people. The quantity and quality of perception of
social support differ in their link to personality, and perceived social support
may, to some extent, be explainable in terms of personality.
PMID- 10687746
TI - Effects of propofol anesthesia on cognitive recovery of patients undergoing
electroconvulsive therapy.
AB - The effects of different doses of propofol on post-electroconvulsive therapy
(ECT) cognitive recovery were evaluated together with the effects on seizure
duration and hemodynamic changes during ECT in 15 depressive patients. Propofol
attenuated the increase in arterial blood pressure and heart rate in a dose
dependent manner compared with thiamylal. Propofol showed a clinically
significant anticonvulsant effect during ECT in a dose-dependent manner. There
were no significant differences among the four different induction groups in the
mean recovery time from anesthesia, however, a low dose of propofol suppressed
the early recovery of cognitive function. For early cognitive recovery after ECT,
a deep anesthetic level is necessary when the traditional ECT apparatus is used
which produces sine curve wave stimuli.
PMID- 10687747
TI - Prevalence and symptomatology of comorbid obsessive-compulsive disorder among
bulimic patients.
AB - This study sought to assess the prevalence and symptomatology of comorbid
obsessive-compulsive disorder (OCD) among Japanese subjects who met the DSM-III-R
criteria for bulimia nervosa (BN). The Structured Clinical Interview for DSM-III
R Patient Version was used to distinguish 26 BN patients with concurrent OCD from
52 BN patients without OCD. Obsessive-compulsive symptoms in BN subjects with
concurrent OCD were evaluated using the Japanese version of the Yale-Brown
Obsessive-Compulsive Scale. There were no differences in the prevalence of
concurrent OCD between BN subjects with and without a lifetime history of
anorexia nervosa. Among BN subjects with concurrent OCD, symptoms related to
symmetry and order were most frequently identified, followed by contamination and
aggressive obsessions, and checking and cleaning/washing compulsions. Bulimia
nervosa subjects with concurrent OCD were more likely than subjects without OCD
to have more severe mood and core eating disorder psychopathology. Comorbid OCD
is a common phenomenon in Japanese bulimics (33%) similar to that suggested in BN
subjects in the Western countries. Obsessive-compulsive symptoms related to
symmetry and order were most frequently observed in BN subjects with concurrent
OCD, which was a similar finding to that reported among restricting anorexic
subjects.
PMID- 10687748
TI - Autonomic function in the early stage of panic disorder: power spectral analysis
of heart rate variability.
AB - Previous studies of autonomic nervous system (ANS) function in panic disorder
(PD) patients have yielded conflicting results. We speculate that these
differences might result from the variety of clinical stages of PD. In order to
investigate this, we compared ANS activity in untreated patients in the early
stage of PD with control subjects using power spectral analysis of
electrocardiogram R-R intervals (PSR-R) in supine rest and during head-up tilt,
which was performed according to the maximum entropy method (MEM). It recognizes
two main components: high-frequency power (HF), which mainly reflects cardiac
parasympathetic activity, and low-frequency power (LF), which reflects both
cardiac sympathetic and parasympathetic activity. The patients with PD had
significantly higher values for all components of PSR-R only in tilt position
total power (TP), LF, and HF than did the control subjects (P<0.01, <0.01, <0.02,
respectively). However, the LF/HF ratio which indicated sympathovagal balance did
not differ significantly between the two groups in tilt position. Our findings
suggest that patients with PD in the early stage of illness have co-activation of
sympathetic and parasympathetic nervous systems, which might act to maintain a
balance between the two autonomic systems.
PMID- 10687749
TI - Delusional disorder: retrospective analysis of 86 Chinese outpatients.
AB - Patients who visited the psychiatric outpatient service of Chang Gung Medical
Centre, Tao-Yuan, Taiwan during an 8-year period were studied retrospectively.
Among the 10,418 outpatients, 86 (0.83%) were diagnosed as having DSM-IV
delusional disorder (DD), including 61 (70.9%) with persecutory type, 12 (14.0%)
with the mixed type, seven (8.1%) with jealous type, two (2.3%) with somatic
type, two (2.1%) with unspecified type, one (1.2%) with erotomanic type, and
another one with grandiose type. The ratio of women to men was 0.86. The mean age
at onset was 42.4 +/- 15.41 years, with women being older than men. Thirty-seven
cases (43.0%) presented with depressive symptoms at their first visit. Subjects
were divided into four groups: persecutory type, jealous type, mixed type and
others. There were no significant differences between the four groups in terms of
gender, age at onset, time-lapse before seeking psychiatric help, the presence of
hallucination or the presence of depression.
PMID- 10687750
TI - Improvement of subjective work performance among obstructive sleep apnea patients
after treatment with continuous positive airway pressure.
AB - Obstructive sleep apnea syndrome (OSAS) is a significant problem for some
patients presenting with snoring and excessive daytime sleepiness. The 'golden
standard' therapy in OSAS is considered to be nasal continuous positive airway
pressure (CPAP). The effects of CPAP on work performance in sleep apnoics has not
been studied previously. One hundred and fifty-two patients with OSAS
participated in an open label study. The patients were diagnosed as suffering
from severe OSAS after they underwent overnight polysomnography showing that
their apnea indexes were at least 20. The participants answered four questions
concerning self-perceived work performance prior to and after using CPAP during 6
months. There were highly statistically significant decreases (P < 0.000001) in
work performance difficulties as graded by the patient. The results of this study
indicate that CPAP treatment improves subjective work performance in patients
suffering from OSAS.
PMID- 10687751
TI - Herbal medicine in the treatment of fluvoxamine-induced nausea and dyspepsia.
PMID- 10687752
TI - Risperidone-induced anxiety might also develop 'awakening' phenomenon.
PMID- 10687753
TI - Symptoms during normal pregnancy: a prospective controlled study.
AB - Symptoms of normal pregnancy have received scant attention in the literature and
what is reported is largely unsubstantiated. Yet this is an important aspect of
antenatal counselling and care which deserves further investigation if symptoms
are to be interpreted correctly. Accordingly, we conducted a prospective
controlled study of symptoms during normal pregnancy in both primigravidas and
multigravidas. A total of 38 symptoms occurred with a significantly different
frequency (mainly increased) in the pregnant subjects in the third trimester
compared with the controls. Of these a mean of 24.2 symptoms was experienced by
each pregnant woman, double that (mean, 11.2) experienced by healthy nonpregnant
controls. The 5 symptoms reported most frequently by the pregnant subjects were
frequency of micturition, fatigue, pelvic pressure, insomnia and lower backache.
However, a wide range of symptoms involving most body systems were reported. This
study has established that symptoms of pregnancy are more numerous than mentioned
in current obstetric texts and that they can be attributed to the effects of
pregnancy. The third trimester is associated with the greatest number of symptoms
and there is a marked decline in their number after delivery.
PMID- 10687754
TI - Microinvasive adenocarcinoma of the cervix.
AB - We evaluated the management of patients with microinvasive adenocarcinoma of the
cervix (MIAC), in particular, to determine the place of conservative surgery, and
determine if the FIGO classification for MIAC is valid and equivalent to the
classification as it applies to microinvasive squamous cancer. A review was
undertaken of the database of the Queensland Centre for Gynaecological Cancer
(QCGC) from January, 1986 to October, 1998. The records of all patients recorded
as having MIAC were retrieved. Microinvasion was defined according to the 1995
FIGO classification as a depth of invasion of no greater than 5 mm and a
horizontal dimension of no greater than 7 mm 30 patients were found to have been
treated for MIAC. The vast majority (29) were asymptomatic, disease being
discovered at the time of routine Papanicolaou smear. There was a 43% incidence
of coexisting squamous intraepithelial neoplasia. Multifocal disease was found in
17% of patients and lymph-vascular positivity in 7%. Eighteen patients were
treated with radical surgery and 13 with conservative surgery. There were no
recurrences over a follow-up interval of 3-116 months. Of the 18 patients treated
with radical surgery, none was found to have occult microscopic disease in the
parametria or nodal metastases. A total of 27 ovaries were removed, all of which
were free of disease. In this small study, MIAC appears to behave in a manner
similar to the squamous equivalent. The results provide some justification for
the FIGO classification of a microinvasive glandular neoplasm of the cervix.
There is some support for a role for conservative surgery in managing this
condition, but there is insufficient worldwide experience to make definitive
recommendations.
PMID- 10687755
TI - A randomized clinical trial comparing oral misoprostol with synthetic oxytocin or
syntometrine in the third stage of labour.
AB - This is a multicentre, blocked, randomized trial to compare the efficacy of oral
misoprostol 400 microg with current injectable uterotonic agents (oxytocin/
Syntometrine) used prophylactically in the third stage of labour. Main outcome
measures were blood loss, use of a second uterotonic agent and difference in
haemoglobin level from antepartum to postpartum. Data analysis from 863 women
showed a statistically significant increase in both the mean blood loss (p <
0.001) and the rate of postpartum haemorrhage > 500 mL, (RR 2.72: 95% C1 1.73
4.27) in the misoprostol group compared to the oxytocin/Syntometrine group. The
use of a second uterotonic agent was higher in the misoprostol group (RR 2.89:
95% Cl 2.00-4.18) as well as a greater decrease in postpartum haemoglobin (p =
0.015). Oral misoprostol 400 microg is significantly less effective than the
traditional intramuscular uterotonic agents currently used and therefore cannot
be considered as a viable option to these agents in the management of the third
stage of labour.
PMID- 10687756
TI - Survival of patients with epithelial ovarian cancer and the effect of
lymphadenectomy in those with stage 3 disease.
AB - This study looks at the 10-year survival data in patients with epithelial ovarian
carcinoma at the Mercy Hospital for Women, Melbourne. An ovarian cancer database
was established at the hospital in 1980, since then 253 patients have been
diagnosed with epithelial ovarian cancer. The 5-year survival rates for Stages 1
to 4 are 75%, 55%, 24% and 21% respectively. The 10-year survival rates are 65%,
55%, 16% and 15% respectively. One hundred and thirty patients have been
diagnosed with Stage 3 disease. The Gynaecologic Oncology Department at the Mercy
Hospital for Women was formalized in 1987. Patients treated for ovarian cancer by
the unit since 1987 had a significantly better survival (median 47 months) than
patients treated prior to 1987 (median 17 months), p = 0.03. There is much debate
as to whether lymphadenectomy in patients with ovarian cancer is of therapeutic
value. In this study the patients with Stage 3 disease and who had a
lymphadenectomy performed had a better 5-year survival rate of 38% compared to
22% in the group who did not have a lymphadenectomy (p < 0.05). The Stage 3
patients who had negative retroperitoneal nodes had a 10-year survival rate of
51%. There was no difference in survival rate between patients with endometrioid
and serous papillary carcinomas.
PMID- 10687757
TI - Induction of labour after 1 previous Caesarean section.
AB - The aim of this study was, after induction of labour in women with a previous
Caesarean section, to compare the outcome in women with a history of a previous
vaginal delivery with women who had never delivered vaginally. A retrospective
analysis was performed over a 2-year period, in a Dublin teaching hospital. One
hundred and three women who had had 1 previous lower segment Caesarean section
had labour induced. Particular attention was given to delivery outcome, history
of a vaginal delivery, cervical effacement at induction, influence of epidural
analgesia, indication for induction and incidence of uterine rupture. The repeat
Caesarean section rate after induction was 20.4%. Of the 51 women who had never
previously delivered vaginally, the repeat section rate was 37.3% compared with
only 3.9% of the 52 women who had previously delivered vaginally (p < 0.01).
Fourteen women who had never delivered vaginally had an uneffaced cervix at
induction and the repeat Caesarean section rate in this group was 64.3%. The
commonest indication for induction was a postdates pregnancy. The use of epidural
analgesia was greater in women who had never delivered vaginally. There were 2
cases of uterine scar rupture. Induction of labour following Caesarean section is
associated with a significantly higher incidence of repeat Caesarean section in
women who have not had a previous vaginal delivery. If the cervix is not effaced
at induction, the repeat Caesarean section rate is higher than if the cervix has
started to efface.
PMID- 10687758
TI - A laparoscopic surgical training and accreditation program up and running.
AB - Beginning in March 1997, a training and accreditation program in laparoscopic
surgery was established at our hospital according to the training guidelines
provided by the Royal Australian and New Zealand College of Obstetricians and
Gynaecologists (RANZCOG) (1, 2). Registrars were accredited upon satisfactory
completion of supervised surgery at each training level. Consultants seeking
clinical privileges in advanced laparoscopic surgery were asked to submit a
formal application. By August 1998, 143 minor laparoscopic procedures had been
formally assessed resulting in 8 of 9 registrars successfully completing training
to level 2 laparoscopy. Thirty-three of 83 (39.8%) advanced laparoscopic
procedures were directly supervised and an experienced laparoscopic surgeon was
available, if required, for a further 15 procedures. Two consultants undertook
additional supervised training before being granted full accreditation for level
3 laparoscopic procedures. Another 2 consultants have been given provisional
accreditation for level 3 procedures. Although challenging, implementation of the
RANZCOG guidelines on training and accreditation in laparoscopic surgery is quite
possible. Greater efforts should be undertaken to establish these guidelines as
the 'gold standard' for hospital accreditation committees.
PMID- 10687759
TI - Argument for the surgical staging of apparent early endometrial cancer.
AB - Cancer of the uterine corpus, commonly referred to as cancer of the endometrium
or cancer of the uterus, continues to be the most common pelvic genital
malignancy affecting western women (1). In 1998 in the United States 36,100 women
were diagnosed with this cancer, and there were 6,300 deaths from this condition
in that year. Of concern is that despite a relatively stable incidence over the
last decade, the annual number of deaths since 1987 from endometrial cancer has
more than doubled (2). Many controversies exist in the management of apparent
early endometrial cancer. These include: 1. The role of surgical staging which
includes pelvic lymphadenectomy. 2. The role of the subspecialist gynaecological
oncologist in primary surgical treatment. 3. Indications for vaginal and external
beam radiotherapy. 4. Who is at risk for recurrence? 5. The role of laparoscopic
approach to the management of this disease. Despite their importance, these and
other issues have not been appropriately addressed by prospective randomized
studies. Treatment strategies and algorithms have thus been based upon a
combination of clinicopathological studies and uncontrolled reviews. The views
expressed in this clinical opinion are those of the Sydney Gynaecologic Oncology
Group and reflect our philosophy on the current management of this tumour,
supported by recent and appropriate peer reviewed scientific literature.
PMID- 10687760
TI - Threatened abortion: prediction of viability based on signs and symptoms.
AB - OBJECTIVE: To examine the relationship between signs and symptoms associated with
threatened abortion and viability of the pregnancy. DESIGN: A prospective
observational study SETTING: A university teaching hospital PARTICIPANTS: One
thousand consecutive women presenting with a threatened abortion. INTERVENTION: A
structured history and an examination were performed as initial clinical
assessment. These were followed by transvaginal sonography to determine the
status of the pregnancy. MAIN OUTCOMES: The relationship between individual signs
and symptoms and the status of the pregnancy was determined. Logistic regression
was performed to determine which signs or symptoms were independent predictors of
spontaneous abortion. RESULTS: A history of having passed a tissue mass, the
presence of products of conception in the vagina and an open cervix were the only
sign or symptom associated with a greater than 90% chance that the pregnancy was
non-viable. Logistic regression of signs and symptoms at presentation indicated
that maternal age greater than 35 years, a history of passing clots vaginally,
vaginal bleeding similar to normal menstruation, increasing vaginal bleeding and
discrepancy of 4 or more weeks between the uterine size on examination and that
which would have been expected by menstrual dates were significant predictors of
nonviable pregnancy. A history of vomiting was predictive of a viable pregnancy.
CONCLUSION: The clinical assessment of threatened abortion is unreliable in most
cases and should be superseded by ready access to sonographic assessment.
PMID- 10687761
TI - Vaginal reconstruction in the fibrotic pelvis.
AB - Vaginal reconstruction was performed in 7 patients who had developed vaginal
stenosis as a result of extensive pelvic fibrosis following either pelvic
irradiation (6 patients) or multiple vaginal procedures (1 patient). Six patients
received split thickness skin grafts and 1 patient received an amnion graft in
the creation of the neovagina. Five patients achieved a satisfactory final
result. All of these patients were sexually active and described adequate sexual
function. There was no serious morbidity associated with these procedures. Safe
and successful vaginal reconstruction can be performed in a patient with a
fibrotic pelvis.
PMID- 10687762
TI - More on management of choroid plexus cysts in the mid-trimester fetus.
PMID- 10687763
TI - Gestational diabetes mellitus. At what time should the postprandial glucose level
be monitored?
AB - OBJECTIVE: To compare selected pregnancy outcomes for women with gestational
diabetes mellitus (GDM) with management based on testing either 1 hour or 2 hours
postprandially according to the ADIPS recommendations. METHODS: Prospective study
of consecutive women referred for the medical management of their GDM. Women were
allowed to select whether they would test either 1 hour postprandial with a
target glucose of < 8.0 mmol/L or 2 hours postprandial with a target glucose of
<7.0 mmol/L. Changes to diet and the introduction and adjustment of insulin
therapy were designed to maintain postprandial glucose levels below these
targets. RESULTS: 166 women elected to test 1 hour postprandial and 101 elected
to test 2 hours postprandial. There were no significant demographic differences
between these 2 groups. The fetal birthweight, percentage of women requiring
insulin and the total daily dose of insulin were similar in both groups.
CONCLUSIONS: For women with GDM, monitoring either 1 hour or 2 hours
postprandially led to similar outcomes. This would suggest that the ADIPS
recommendations are equivalent and therefore women can choose the most convenient
time for their postprandial monitoring.
PMID- 10687764
TI - Women's knowledge and attitudes about emergency contraception: a survey in a
Melbourne women's health clinic.
AB - The aim of the study was to determine the level of awareness of emergency
contraception in women seeking pregnancy counselling and to investigate their
attitudes towards emergency contraception. All women presenting for pregnancy
counselling at a Melbourne women's health clinic in October 1997 were invited to
complete a questionnaire detailing their contraceptive practices. One hundred and
sixty-six questionnaires were distributed and 153 were completed (92% response
rate). The majority of this sample population had heard of some form of emergency
contraception and knew where to access it. However only 26% knew that emergency
contraception should be taken within 72 hours of unprotected intercourse.
Although 80% of the sample had heard of emergency contraception (or the morning
after pill) only 9% used it in an attempt to prevent this pregnancy. The majority
of the women surveyed support the increased availability of emergency
contraception by rescheduling it to a non-prescription item and re-packaging as a
single treatment.
PMID- 10687765
TI - Comparison of epidural and general anaesthesia for elective caesarean delivery
according to the effects of apgar scores and acid-base status.
AB - The objective of this study was to determine the effects of lumbar epidural
anaesthesia on the Apgar score and acid-base status of the newborn. Umbilical
artery blood gases were obtained in 85 singleton, term, uncomplicated pregnancies
delivered by elective Caesarean section. The umbilical artery blood pH, PaCO2,
PaO2 and HCO3 values and Apgar scores (1 and 5 minutes) were compared between
lumbar epidural and general anaesthesia groups. General anaesthesia was used in
45 (52.9%) women and lumbar epidural anaesthesia in 40 (47.1%). Only 2 of the
newborns exposed to epidural anaesthesia had umbilical artery blood pH values
7.19 or less. The mean umbilical artery blood pH was found to be significantly
lower in the newborns exposed to lumbar epidural anaesthesia (p = 0.011). None of
the newborns in the 2 groups were severely depressed (Apgar scores less than 4).
The mean umbilical artery blood PaCO2, PaO2 and HCO3 values did not show any
significant difference between the groups. In conclusion, lumbar epidural
anaesthesia is associated with lower umbilical artery blood pH values,
occasionally with severe fetal acidaemia.
PMID- 10687766
TI - Oral methotrexate in the management of refractory interstitial cystitis.
AB - To establish the safety and efficacy of low-dose oral methotrexate in treating
refractory interstitial cystitis, 9 women who fulfilled internationally accepted
criteria for the diagnosis of interstitial cystitis were enrolled in a
prospective study. All had proven unresponsive to conventional treatment
modalities. Assessment by pain score and frequency volume charts was performed
pretreatment and up to 6 months during therapy. No significant adverse side
effects were noted. At the end of follow-up, 4 women had noted a subjective
improvement in bladder pain and wished to continue on methotrexate, 4 women noted
little change and 1 woman reported a worsening of symptoms. Overall there was a
significant reduction in pain score (p = 0.047) posttreatment. However, there was
no significant difference in urinary frequency per 24 hours (p = 0.40), maximum
voided volume (p = 0.089) or mean voided volume (p = 0.59). Methotrexate
significantly improved bladder pain in women with interstitial cystitis, although
no significant change was found in voiding pattern.
PMID- 10687767
TI - A retrospective review of perioperative complications in 360 patients who had
Burch colposuspension.
AB - This retrospective study reviews intraoperative and early complications of Burch
colposuspension of 360 patients. Ten patients had massive haemorrhage and 8 of
them had a blood transfusion. Three patients had a haematoma. Bladder injuries
were noticed in 10 patients, 3 of whom were diagnosed postoperatively. One
patient had unilateral ureteral kinking. Urinary retention occurred in 20
patients for more than 10 days and 2 required catheterization for 26 and 32 days
respectively. Eighteen patients had a wound infection and 4 had a wound abscess.
Twenty nine patients had a urinary infection. Urinary tract injury, haemorrhage
and blood transfusion were significantly more common in women having secondary
surgery than those having primary surgery. Deep venous thrombosis was diagnosed
in 3 patients who had a Burch colposuspension with concomitant abdominal
hysterectomy. Knowledge of possible risks and complications of Burch
colposuspension may help plan a better preoperative work-up of patients and may
minimize the intraoperative complications and increase surgical success and
patient satisfaction.
PMID- 10687768
TI - Chronic pain as the main presenting symptom of depression following hysterectomy
in old age.
PMID- 10687769
TI - Glucose intolerance and other cardiovascular risk factors in chinese women with a
history of gestational diabetes mellitus.
AB - Women with a history of gestational diabetes (GDM) are at increased risk of
developing diabetes compared with other women. There are few data on associations
between GDM and cardiovascular risk factors. Between 1988 and 1995, 801 Chinese
women with a history of GDM were recruited for a 75g oral glucose tolerance test
(OGTT) and assessment of various cardiovascular risk factors, namely obesity,
hypertension and dyslipidaemia, 6 weeks after delivery at the Diabetes Centre of
the Prince of Wales Hospital. Another 431 women with no past history of diabetes
or GDM recruited in a diabetes prevalence study were used as control subjects.
After adjustment for age, body mass index and smoking, the prevalence of glucose
intolerance remained higher in women with a history of GDM when compared to
normal controls. The relative risks of obesity, hypertension, dyslipidaemia,
diabetes and impaired glucose tolerance in women with a history of GDM comparing
to normal subjects were, respectively, 2.4, 7.5, 2.4, 8.1 and 5.0. After
excluding those with abnormal glucose tolerance, subjects with a history of GDM
still had more adverse cardiovascular risk factors, including higher blood
pressure, glycaemic and lipid parameters, than control subjects (after adjustment
for age, body mass index and smoking). In conclusion, compared with normal
subjects, Chinese women with a history of GDM had an 8-fold increased risk of
having diabetes based on their OGTTs performed 6 weeks postdelivery. These women
also have increased rates of other cardiovascular risk factors including obesity,
high blood pressure and dyslipidaemia.
PMID- 10687770
TI - Estimation of oxidative products of nitric oxide (nitrates, nitrites) in
preeclampsia.
AB - Oxidative products of nitric oxide, serum nitrates and nitrites were estimated in
50 primigravidas with preeclampsia and in 50 gestation and age-matched
normotensive primigravidas. Thirty three (66%) of these women had mild
preeclampsia and 17 (34%) had severe preeclampsia. Serum nitrate and nitrite
levels were significantly higher in preeclamptic women (nitrates - 15 +/- 1.17;
nitrites - 11.82 +/- 1.16 micromol/L) than in the normotensive pregnant women
(nitrates 11.82 +/- 1.16; nitrites - 5.08 +/- 0.47 micromol/L, p < 0.001). In
preeclamptic women, serum nitrate and nitrite levels correlated with the severity
of the disease (mild preeclampsia nitrate - 14.46 +/- 1.98; nitrite 6.21 +/- 0.84
micromol/L, severe preeclampsia nitrate - 16.65 +/- 3.64; Nitrite - 6.87 +/- 1.56
micromol/L). In preeclampsia there was significant positive correlation between
nitrate and nitrite levels and diastolic blood pressure and proteinuria.
PMID- 10687771
TI - Transvaginal chorionic villus sampling-an alternative approach.
PMID- 10687772
TI - Choriocarcinoma developing after prolonged molar surveillance.
PMID- 10687773
TI - A cervical ectopic pregnancy managed by medical treatment and angiographic
embolization.
AB - Medical treatment in the form of systemic methotrexate with or without local
methotrexate/potassium chloride is effective for early cervical pregnancy. It
should be the treatment of choice in suitable cases. Haemorrhagic complications
can be effectively managed by angiographic embolization. A case report
illustrating these points is presented.
PMID- 10687774
TI - Prenatal diagnosis and management of sacrococcygeal teratoma.
AB - Five fetuses, each with a sacrococcygeal teratoma (SCT) were delivered at the
Royal Women's Hospital while 2 fetuses, each with a SCT were delivered at Monash
Medical Centre in 1998. The number of cases reported in this series is higher
than expected but it most likely occurred due to chance. The diagnosis was made
prenatally in all cases. Three of the SCT were entirely external while the
remaining 4 were external with intrapelvic extension. Rapid growth of the SCT
occurred in 3 fetuses. This was associated with polyhydramnios in 2 fetuses. No
fetus developed nonimmune hydrops. Six infants were liveborn (perinatal mortality
rate of 14%), 3 of whom were delivered prior to 37 weeks' gestation. Two infants
were delivered by classical Caesarean section. The remaining 4 infants were
delivered by lower uterine segment Caesarean section. There was 1 perinatal
death. This stillborn infant was delivered vaginally. The 6 surgical resections
were performed between the 4th and 10th postnatal days. Histological examination
confirmed the diagnosis of benign SCT in each. One infant developed a recurrence
at 2 months of age and required chemotherapy.
PMID- 10687775
TI - Pilonidal disease of the pubic region.
PMID- 10687776
TI - Pregnancy and cirrhosis of the liver.
AB - Pregnancy in patients with cirrhosis of the liver is uncommon. We reviewed 9
pregnancies in 7 patients with cirrhosis. One patient conceived within 1 month of
diagnosis and in another the disease was diagnosed during the index pregnancy.
Four patients has associated portal hypertension and 1 of them conceived after
lienorenal shunt. Complications associated with these pregnancies were jaundice
(1) jaundice plus ascites (2) and gastrointestinal bleeding (1). In 2 patients
endoscopic sclerotherapy was done during the index pregnancy. The incidence of
preterm delivery was 50% (4 of 8) and the majority (75%) occurred in pregnancies
where associated complications were present. There was 1 maternal death in the
postpartum period due to fulminant hepatic failure.
PMID- 10687777
TI - Twin pregnancy in a uterus didelphys, with unilateral placental abruption and
onset of labour.
AB - A dizygotic twin pregnancy with a fetus in each side of a uterus didelphys is
described. An antepartum haemorrhage at 26 weeks' gestation, with subsequent
onset of contractions in the right-sided uterus, precipitated delivery by
Caesarean section.
PMID- 10687778
TI - A new indication for breech extraction.
PMID- 10687779
TI - Complete hydatidiform mole with coexisting normal fetus-report of two cases.
PMID- 10687780
TI - Endometrial ossification in infertile patients-report of 3 cases.
PMID- 10687781
TI - Pelvic sepsis complicating embolization of a uterine fibroid.
PMID- 10687782
TI - Conservative management of a case of placenta praevia percreta.
AB - Pregnancies complicated by placenta praevia and a history of caesarean section
are associated with increased risk of placenta percreta (1). Placenta praevia
percreta sometimes involves the bladder or other pelvic organ, invasion leading
to genital bleeding or haematuria (2, 3). Bladder injury or uncontrollable
profuse haemorrhage occasionally occurs in such patients during surgery.
Examination of placental invasion is necessary as this clinical condition is
severe. Treatment of placental myometrium invasion is required to prevent
uncontrollable profuse haemorrhage during surgery. We present a multiparous
patient who was diagnosed prenatally with placenta praevia percreta using
magnetic resonance imaging (MRI) and who was treated conservatively with a good
prognosis.
PMID- 10687783
TI - Pyomyoma: a case report.
PMID- 10687784
TI - A severe case of post-antibiotic clostridium difficile colitis.
PMID- 10687785
TI - Birth asphyxia, cerebral palsy and litigation.
PMID- 10687786
TI - Caesarean section delivery on registrar experience in vaginal breech delivery.
PMID- 10687787
TI - Embolic occlusion for the treatment of uterine myomas.
PMID- 10687788
TI - Advances in ultrasound biomicroscopy.
AB - The visualisation of living tissues at microscopic resolution is attracting
attention in several fields. In medicine, the goals are to image healthy and
diseased tissue with the aim of providing information previously only available
from biopsy samples. In basic biology, the goal may be to image biological models
of human disease or to conduct longitudinal studies of small-animal development.
High-frequency ultrasonic imaging (ultrasound biomicroscopy) offers unique
advantages for these applications. In this paper, the development of ultrasound
biomicroscopy is reviewed. Aspects of transducer development, systems design and
tissue properties are presented to provide a foundation for medical and
biological applications. The majority of applications appear to be developing in
the 40-60-MHz frequency range, where resolution on the order of 50 microm can be
achieved. Doppler processing in this frequency range is beginning to emerge and
some examples of current achievements will be highlighted. The current state of
the art is reviewed for medical applications in ophthalmology, intravascular
ultrasound, dermatology, and cartilage imaging. Ultrasound biomicroscopic studies
of mouse embryonic development and tumour biology are presented. Speculation on
the continuing evolution of ultrasound biomicroscopy will be discussed.
PMID- 10687789
TI - Significant changes in transrectal ultrasonic measurements of the prostate in
relation to the degree of rectal wall distension.
AB - The present study was conducted to reveal the possible changes in transrectal
ultrasonic measurements of the prostate in relation to the degree of rectal wall
distension. When analyzed together for 51 men, all measurements but area changed
statistically significantly as the rectal wall was distended by a balloon
covering a probe. Ultrasonic measurements concerning the prostatic shape changed
more remarkably than those concerning its size. More importantly, changes in
ultrasonic measurements were much more remarkable in patients with a healthy
prostate than in those with an advanced BPH. These results suggest that possible
changes in prostatic shape with the rectal wall distension has to be taken into
account when evaluating transrectal prostatic ultrasonograms in terms of changes
in shape, especially in patients with a healthy prostate. This is also the case
when the diagnosis of BPH is made based on the change in shape, such as presumed
circle area ratio, which is a parameter representing the roundness of the
horizontal sonogram of the prostate.
PMID- 10687790
TI - Prevalence and risk factors of low quantitative ultrasound values of calcaneus in
Korean elderly women.
AB - Quantitative ultrasound (QUS) of bone is a new radiation-free, low-cost method
that measures both bone mass and bone quality. This study was performed to
establish the normative data of QUS for Korean women and to determine the
prevalence and risk factors of low quantitative ultrasound values in a Korean
elderly population. We studied 238 healthy women aged 20-29 years working at a
hospital, and 552 women over 50 years of age living in six villages of Chung-Up
district, a rural area of South Korea, using QUS measurement of bone. Broadband
ultrasound attenuation and speed of sound were measured at the calcaneus, and an
index combining these factors (stiffness index) was calculated. T-score was
calculated from the data of young normal subjects. Of the 552 elderly women,
34.2% had T-scores between -1.0 and -2.5, and 11.8% had T-scores below -2.5. The
prevalence of low quantitative ultrasound values increased with older age, longer
duration following menopause, lower body mass index, younger age at menopause and
smoking. In multiple logistic regression analysis, age (odds ratio = 1.40 per 5
years, P < 0.05), duration following menopause (odds ratio = 1.35 per 5 years, P
< 0.05) and body mass index (odds ratio = 0.78 per quartile, P < 0.05) were
independently associated with low quantitative ultrasound values. These results
suggested that quantitative ultrasound measurement of the calcaneus could be a
useful tool for epidemiological surveys of bone mass.
PMID- 10687791
TI - Colour Doppler ultrasound: a new index improves the diagnosis of renal artery
stenosis.
AB - The description of a new index, the renal-segmental ratio (RSR), and the
comparison of its performance with other conventional Doppler parameters for the
detection of renal artery stenosis (RAS). A total of 96 renal units were studied
with angiography and colour Doppler ultrasound (US) independently. The Doppler
parameters applied were: 1. renal artery peak systolic velocity (RE-PSV), 2.
renal-aortic ratio (RAR), 3. early systolic acceleration (ESA), and 4. renal
segmental ratio (RSR). The angiographic study was used as the "gold standard" for
the identification of > or = 50% RAS. The results indicate that RSR (sensitivity:
93.33%, specificity: 89.47%) and RE-PSV (sensitivity: 83.33%, specificity:
89.47%) were the best criteria for RAS diagnosis (p values <0.05). The results
show that colour Doppler US is a reliable diagnostic modality for RAS diagnosis.
The new index (RSR) improves the effectiveness of the method.
PMID- 10687792
TI - Reactive pulmonary artery vasoconstriction in pulmonary consolidation evaluated
by color Doppler ultrasonography.
AB - A total of 122 patients with pulmonary consolidation on chest radiographs
underwent color Doppler ultrasonography to evaluate hemodynamic change in
regional pulmonary artery in pulmonary consolidation due to various causes. The
diseases underlying pulmonary consolidation included 66 simple pneumonia, 37
obstructive pneumonia, 13 tumor consolidation and 6 pulmonary infarctions. Blood
flow signals in consolidation were detected by color-flow mapping. The degree of
reactive vasoconstriction was evaluated from analysis of the spectral waveform of
the blood flow in the segmental pulmonary artery by several vessel resistance
indicating Doppler ultrasound (US) indices, including pulsativity index (PI),
resistive index (RI), and acceleration time (AT). The results showed that
reactive vasoconstriction was most marked in obstructive pneumonia, followed by
simple pneumonia, and least in tumor consolidation (p < 0.001, Kruskal-Wallis
test and p < 0.001, Dunn's test for comparison of PI, RI and AT values between
different groups of pulmonary consolidation). No flow was detected in pulmonary
infarction. We conclude that color Doppler US is a useful tool for evaluating
reactive vasoconstriction in pulmonary consolidation. The different degrees of
reactive vasoconstriction may be helpful in exploring the possible etiology of
pulmonary consolidation.
PMID- 10687793
TI - Vertebral arteries and neck rotation: Doppler velocimeter and duplex results
compared.
AB - The purpose of this study was to test the validity of Doppler ultrasound (US)
velocimeter examination of vertebral arteries during contralateral (to the
opposite side) cervical rotation. Vertebral arteries from 20 subjects were
insonated using a bidirectional Doppler velocimeter at the suboccipital portal
(standard technique) and C2 transverse process level (new technique) during
contralateral cervical rotation. The results, regarding persistence or major
reduction in Doppler signals, were then compared with those from a colour-flow
duplex US scanner using the same procedure. There was complete agreement between
the combined suboccipital and C2 velocimeter results and those from the duplex
scanner (k = 1.00 at p = 0.01): both sensitivity (n = 5) and specificity (n = 34)
were 100%. This study provides evidence to support the validity of bidirectional
Doppler velocimeter examination, by an experienced examiner, for the purpose of
assessing the effects of contralateral rotation on vertebral artery blood flow.
PMID- 10687794
TI - High-frequency color flow imaging of the microcirculation.
AB - The extension of ultrasound (US) color flow imaging (CFI) techniques to high
frequencies (> 20 MHz) has the potential to provide valuable noninvasive tools
for scientific and clinical investigations of blood flow in the microcirculation.
We describe the development of a slow-scan CFI system operating in the 20-100-MHz
range that has been optimized to image the microcirculation. The apparatus has
incorporated elements of a previously reported pulsed-wave Doppler system and is
capable of operating in either CFI or pulsed-wave mode. The performance of the
CFI system was evaluated at a center frequency of 50 MHz using two PVDF
transducers with -6-dB beam widths of 43 and 60 microm. The -6 dB-axial
resolutions were estimated to be 66 and 72 microm, respectively. In vivo
validation experiments conducted using the murine ear model demonstrated the
detection of flow in vessels down to 15-20 microm in diameter with flow
velocities on the order of mm per s. Further experiments examining experimental
murine tumors confirmed the successful detection of flow in the tumor
microcirculation.
PMID- 10687795
TI - Classification of arterial plaque by spectral analysis of in vitro radio
frequency intravascular ultrasound data.
AB - To test whether radio-frequency analysis of coronary plaques predicts the
histological classification, r.f. data were collected using a 30 MHz
intravascular ultrasound scanner. Two hundred ninety-nine regions-of-interest
from eight postmortem coronary arteries were selected and identified by histology
as falling into one of seven different tissue types. These are loose fibrous
tissue (n = 78), moderate fibrous tissue (n = 27), dense fibrous tissue (n = 33),
microcalcification (n = 14), calcified plaque (n = 55), lipid/fibrous mixture (n
= 51) and homogeneous areas of lipid pool (n = 29). On the basis of a previous
study, four spectral parameters were calculated for each of the regions-of
interest: maximum power (dB), mean power (dB), spectral slope (dB/MHz) over the
bandwidth 18-35 MHz and the intercept of the spectral slope with the 0 Hz axis
(dB). A minimum-distance classifier using the Mahalanobis (1948) distance was
applied to the data. Following resubstitution of the training data into the
classifier, the total correctly classified was 54%. The data were reclassified
using three broader tissue groups: (1) calcified plaque, (2) lipid pool and (3) a
mixed fibrous category, incorporating loose fibrous tissue, moderate fibrous
tissue, dense fibrous tissue, lipid/fibrous mixture and microcalcification. The
total correctly classified was 86%. Using "leave-one-out" cross-validation, the
classification rates were 48% for seven tissue subgroups and 83% for three
broader categories of tissue type.
PMID- 10687796
TI - Fundamental studies on contrast images from different-sized microbubbles:
analytical and experimental studies.
AB - Microbubbles are very useful as ultrasound (US) contrast agents because of their
excellent scattering properties. Because microbubbles of different sizes can be
used for this purpose, the contrast images produced by different-sized
microbubbles are studied in this paper. The contrast images from microbubbles of
average sizes 35.5 microm and 2.1 microm were investigated experimentally.
Although a low concentration of microbubbles produces contrast-enhanced images
without artefacts, an excess of microbubbles results in distorted images. From
experimental observation, the distortion of an image caused by microbubbles of
average size 35.5 microm was mainly due to multiple scattering, and that by 2.1
microm microbubbles was due to the acoustic shadowing effect. With the use of the
tissue-mimicking phantoms of known acoustical properties, the brightness of the
contrast images from the microbubble suspension was calculated. The calculated
and experimental results of the contrast images produced from microbubbles of
average size 35.5 microm were closer to each other when there was no image
distortion. When image distortion caused by multiple-scattering occurred, the
experimental pixel brightness was higher. For smaller microbubbles of average
size 2.1 microm, calculated results of free microbubbles showed a weaker contrast
effect than the experimental results. By taking the effect of the coatings of
microbubbles into consideration, the calculated brightness of contrast images
became much closer to the experimental one.
PMID- 10687797
TI - Ultrasonic characterization of the nonlinear properties of contrast microbubbles.
AB - The nonlinear properties of microbubble contrast agents have been used to create
contrast-specific imaging modalities such as harmonic imaging and subharmonic
imaging. Thus, a better understanding of the nonlinear performance of contrast
microbubbles may enhance the diagnostic capabilities of medical ultrasound (US)
imaging. The first and second harmonic, the 1/2 order subharmonic and the 3/2
order ultraharmonic components in spectra of scattered signals from Optison
microbubbles insonified at 2 and 4 MHz have been investigated using an in vitro
laboratory pulse-echo system. The development of these signal components over
time is quite different for 2-MHz insonification compared to 4-MHz
insonification. Scattered subharmonic and ultraharmonic signals are much more
time-dependent than first and second harmonic echoes. The dependence of the first
and second harmonic, subharmonic and ultraharmonic components on acoustic
pressure for 2-MHz insonification is similar to that for 4-MHz insonification.
The first and second harmonic components increase linearly with acoustic pressure
(in double logarithmic scales) and the subharmonic and ultraharmonic amplitudes
undergo rapid growths in the intermediate acoustic pressure range and much slower
increases at both lower and higher acoustic pressures.
PMID- 10687798
TI - Evaluation of an experimental system for the in vitro assessment of ultrasonic
contrast agents.
AB - The ultrasonic properties of microbubble contrast agents need to be fully
understood if reproducible images and quantitative results are to be produced.
Additional aspects of the physical and chemical environment into which the
contrast agents are introduced also need to be taken into account, and their
effect on contrast agent performance evaluated. A setup that provides an accurate
and reproducible data-acquisition system is presented and evaluated in this
paper. The linear range of this system is assessed, as well as its accuracy and
precision. A new approach to the investigation of contrast agents, based on
normalised backscatter, is discussed. Also, a common technique of degassing,
widely used in other areas, is described and evaluated to determine its
appropriateness to contrast agent studies.
PMID- 10687799
TI - In vitro flow quantification with contrast power Doppler imaging.
AB - To evaluate the effectiveness of contrast harmonic (power Doppler imaging) as an
ultrasonic modality to quantify flow, an in vitro model of perfusion was studied
using Optison, a second-generation ultrasound (US) contrast agent. The in vitro
model was made of two dialysis cartridges placed parallel and allowed absolute
and relative flow quantification on both tube (entry lines) and tissue
(cartridges) simulations. Video intensity curves were generated using
intermittent harmonic power Doppler imaging after bolus injection of contrast.
Correlation between flow and different parameters extracted from time-intensity
curves and previously defined as indicators of flow was established for both
tissue and entry lines, for flow rates ranging from 0 to 400 mL/min. Single
compartment equations were also tested on the model. A good correlation for the
tissue model was observed between absolute flow and onset time (O), time to
maximal enhancement (TME), peak intensity (P), area under the curve (AUC), and
maximal ascending slope (S) parameters, with a r = 0.94, 0.94, 0.91, 0.92 and
0.92, respectively. The correlation for O, TME, P and AUC parameters was r =
0.86, 0.90, 0.78 and 0.82, respectively for entry lines. The correlation for
tissue model and entry line was slightly improved when comparing flow ratios with
peak ratios (P1/P2) and slope ratios (S1/S2) (r = 0.95 and 0.94). Flow
calculation using the gradient-relationship method also showed a good correlation
(r = 0.88) with the experimental flow. The results obtained indicated that
absolute and relative quantification of flow using PDI is feasible in tube and
tissue models. Several clinical applications, namely in myocardial, hepatic and
renal artery studies, could be derived from these results.
PMID- 10687800
TI - A real-time two-dimensional pulsed-wave Doppler system.
AB - An experimental system was developed to acquire and visualise in real-time two
dimensional (2-D) velocity maps. Data acquisition is performed by using a
modified commercial echograph based on a 5-MHz, 128-element linear-array
transducer with electronic focussing and beam steering. Additional electronics
were integrated into the echograph to implement a 2-D Doppler system capable of
measuring the velocity component on the scanning plane. Suitable axial and
lateral scanning methods were studied to obtain Doppler measurements over a
scanning area. A colour image of the estimated velocity field is presented in
real time on a personal computer using different visualisation techniques. The
system performance was tested experimentally both in vitro and in vivo on a human
carotid artery.
PMID- 10687801
TI - An interactive tool to visualize three-dimensional ultrasound data.
AB - Three-dimensional ultrasound can provide images that are easily understood by
people who are not specialists in ultrasonography. However, current visualization
methods do not perform very well on 3-D ultrasound data. Apart from some specific
cases (obstetrics, cardiology), 3-D ultrasound images have not yet demonstrated
major benefits from a clinical point of view. In this article, we introduce an
interactive method that allows the user easily to produce 3-D images for each
ultrasound examination. It is a two-step method. First, the user roughly segments
the data by drawing three boundary curves in perpendicular planes. A ray-casting
algorithm then automatically retrieves the details of the objects. Because it can
be used routinely, this tool should help to evaluate the potential of 3-D
ultrasonography.
PMID- 10687802
TI - Effects of phase aberration on high frame rate imaging.
AB - A high frame-rate (HFR) imaging method (about 3750 frames/s for imaging of
biological soft tissues at a depth of 200 mm) has been developed recently with
limited diffraction beams. This method uses the fast Fourier transform (FFT) and
inverse fast Fourier transform (IFFT) to construct images, and can be implemented
with simple and inexpensive hardware, compared to the conventional delay-and-sum
method where a digital beam former is usually used. In this paper, phase
aberration effects are studied for both the high frame rate and the conventional
methods by adding random phase shifts to echo signals obtained from an
experiment. In the study, two broadband linear arrays were used to construct
images of an ATS 539 tissue-equivalent phantom that has a frequency-dependent
attenuation of about 0.5 dB/MHz/cm. The first array has 48 elements, a central
frequency of 2.25 MHz, an aperture of 18.288 mm, and a width of 12.192 mm in
elevation. The second has 64 elements, a central frequency of 2.5 MHz, and a
dimension of 38.4 mm x 10 mm. The-6dB pulse-echo bandwidth of both arrays is
about 40% of their center frequencies. Radiofrequency (RF) signals were digitized
at 20 mega samples/s at a 12-bit resolution to construct images. Results show
that phase aberration has about the same effect on both methods in terms of image
resolution and contrast, although the high frame-rate method can be implemented
with a simpler system.
PMID- 10687803
TI - New piezoelectric transducers for therapeutic ultrasound.
AB - Therapeutic ultrasound (US) has been of increasing interest during the past few
years. However, the development of this technique depends on the availability of
high-performance transducers. These transducers have to be optimised for focusing
and steering high-power ultrasonic energy within the target volume. Recently
developed high-power 1-3 piezocomposite materials bring to therapeutic US the
exceptional electroacoustical properties of piezocomposite technology: these are
high efficiency, large bandwidth, predictable beam pattern, more flexibility in
terms of shaping and definition of sampling in annular arrays, linear arrays or
matrix arrays. The construction and evaluation of several prototypes illustrates
the benefit of this new approach that opens the way to further progress in
therapeutic US.
PMID- 10687804
TI - Effects of ultrasound and 1,25-dihydroxyvitamin D3 on growth factor secretion in
co-cultures of osteoblasts and endothelial cells.
AB - It has been shown that low-intensity pulsed ultrasound (US) accelerates fracture
healing in animal models and in clinical studies. However, the mechanism by which
US accelerates fracture healing remains unclear. Systemic factors and several
growth factors, such as platelet-derived growth factor (PDGF), are thought to be
involved in the process of fracture healing. In the present study, we examined
the effects of US and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] on growth factor
secretion in a co-culture system of human osteoblastic cells (SaOS-2) and
endothelial cells (HUVEC). US was applied to cultured cells for 20 min daily for
four consecutive days. US treatment increased the PDGF-AB level in the
conditioned media. 1,25-(OH)2D3 (1 x 10(-8) M) also enhanced PDGF-AB secretion.
The secretion of PDGF-AB was synergistically increased by the combination of US
and 1,25-(OH)2D3. These results suggest that the stimulation of growth factor
secretion from cells by US and 1,25-(OH)2D3 treatment may be involved in the
acceleration of fracture healing.
PMID- 10687805
TI - Nurses' and doctors' attitudes towards suicidal behaviour in young people.
AB - This paper presents an exploratory study performed to identify the attitudes
towards suicidal behaviour in young people, amongst nurses (and nursing
lecturers), and doctors working in in-patient medical and mental health care
settings. The Suicide Opinion Questionnaire (SOQ) was administered to 59
participants. Responses were scored using eight clinical scales, and tested by
using a Kruskal-Wallis one way analysis of variance. An Independent Sample t-test
was used to analyse gender differences. Qualitative interviews were conducted in
a sample of respondents. SOQ findings revealed no overall significant differences
in the relevant groups of nurses and doctors, with the exception of gender and
the clinical scale relating to a 'Cry for Help'. The focused interviews generated
five categories relating to suicidal behaviour and young people. Nurses and
doctors working in these areas possess a range of influential perceptions of
suicidal behaviour and need to be considered in the contexts of care and
treatment of young people.
PMID- 10687806
TI - Student nurses' lived experience of preceptorship. Part 1--in relation to
learning.
AB - In this first part of a research project a phenomenological approach was applied
to understanding student nurses' experience of preceptorship. The lived
experience of seventeen student nurses learning within a preceptor-preceptee
relationship on hospital wards formed the basis of the study. Tape-recorded
interviews were conducted, transcribed and analysed. The phenomenological
hermeneutic analysis revealed three themes of meaning central to the lived
experience of learning. These were (a) directing learning; (b) learning in
practical action and (c) feeling in learning. The themes included six sub-themes
with internal variations. The results indicate that learning, as a phenomenon,
could be understood as being in different modes of learning, including directing
learning, learning in practical actions and feeling in learning. Each theme was
also found to be inherent in the others in an ongoing changeable process. The
findings were compared with Aristotle's five modes of learning and revealed that
the student nurses' learning embraced scientific knowledge, technical skills,
practical wisdom and limited intuition. The study may provide nurse educators
with some insight into student nurses' learning by being in real-life situations
and performing nursing actions within a preceptor-preceptee relationship.
PMID- 10687807
TI - Student nurses' lived experience of preceptorship. Part 2--the preceptor
preceptee relationship.
AB - Student nurses' experience of preceptorship was the focus of this second part of
a phenomenological study. The aim was to illuminate student nurses' lived
experience of the preceptor-preceptee relationship on hospital wards. A
phenomenological-hermeneutic analysis was made of tape-recorded interviews with
seventeen student nurses. The interpretation process culminated in four themes,
namely: (a) creating space for learning; (b) providing concrete illustrations;
(c) exercising control and (d) seeking reflection. Each theme included sub-themes
with internal variations. The theme 'creating space for learning' was understood
as basic in relation to the other themes and as the foundation of student
learning and preceptoring. The ongoing process of preceptoring meant that the
preceptors acted as role models, were with the students and also exercised
control. Control was directed both to patient safety and to student learning. The
students' 'seeking reflection' included attempts to find peace and quiet either
by themselves or with the preceptor. The reflection together with the preceptor
facilitated the students' transformation of knowledge, from the specific
situation to a general knowledge and increased the value of learning.
PMID- 10687808
TI - Caregiver burden and health promotion.
AB - Few of the studies describing caregiver stress and burden have focused on the
effects of caregiving on the ability of the caregiver to attend to his or her own
health needs. Therefore, the major purpose of this study was to investigate
whether the perception of burden is related to the health-promoting behaviors of
caregivers of the elderly. One hundred twenty-one predominantly female
caregivers, mean age 61.1 years, S.D. = 13.4, completed questionnaires measuring
demographic and health-related factors, the Objective and Subjective Burden
Scales, and the Health-Promoting Lifestyle Profile. Findings suggest that those
perceiving lower subjective burden practice more health-promoting behaviors than
those with higher subjective burden scores, confirming Pender's contention that
situational factors, such as caregiver burden, may affect health promotion.
PMID- 10687809
TI - Qualitative research to identify racialist discourse: towards equity in nursing
curricula.
AB - Professional curriculum planning is beginning to address issues of equity. The
authors report on findings from a research initiative to begin to integrate
antiracism into an undergraduate curriculum. Theory and methods of Essed, Fanon,
Frankenberg, Hall, van Dijk and Woodward are synthesized for interpreting
racialist discourse. The findings support the principle of normalizing
accountability for discourse practices which construct whiteness and otherness in
their representations. Essentialist discourse practices are implicated in the
perpetuation of racism, ableism, heterosexism, ageism, etc. Hence, the ideal of
equity is expanded to include the enactment of non-essentialist discourse. The
logic is revealed as either/or; either equity or dominance through normalized
perpetuation of essential categories assigning negative value to others
constructing difference, marginalization, problematization, exclusion and
containment. The confused, middle or neutral position is one of condoning racism
and other forms of dominance.
PMID- 10687810
TI - The alcohol use disorders identification test (AUDIT): validation of an
instrument for enhancing nursing practice in Hong Kong.
AB - This paper describes the psychometric analysis of the alcohol use disorders
identification test (AUDIT) after it was modified for use in Hong Kong and
administered to examine the patterns of hazardous and harmful drinking. The
modified version of AUDIT was an 18-item instrument in which 10 items were
completely adopted from the original version and 8 items were added to improve
its cultural sensitivity. It was translated into Chinese and back translation was
undertaken to confirm the equivalence of the Chinese and English versions.
Following a pilot study the instrument was administered to 450 subjects who were
recruited from two acute general hospitals, a University Health Clinic and three
community health centres. The content validity was judged as adequate by a panel
of five international and local experts and the instrument achieved a high
reliability coefficient of 0.99 during a test-retest procedure conducted with 20
subjects. Factor analysis was performed on the responses obtained from 450
subjects which supported the construct validity of the 18-item instrument. The
modified instrument had a consistently high internal consistency reliability
(Cronbach's alpha=0.96-0.97) when tested in the different settings. It was found
that a higher percentage of respondents from the hospitals (14.5%) drank at a
hazardous or harmful levels compared to those from the community (6.2%) or the
University (5.3%). The AUDIT proved a reliable and valid measure with potential
applications in Chinese cultures. Early intervention and identification of 'at
risk' drinking by the AUDIT is supported as a strategy to be implemented by
nurses in primary and secondary health care settings in Hong Kong, where there
are indications of increasing alcohol overuse.
PMID- 10687811
TI - Developing a model of collaborative research: the complexities and challenges of
implementation.
AB - While the benefits of collaborative research have been well documented, fewer
publications exist regarding the complex, problematic issues involved in these
undertakings. This paper offers an integrated collaborative research model to
depict the complexities and challenges of initiation and implementation of a 2
1/2 year joint research project between a community hospital and a university
school of nursing in Southern Ontario, Canada. A sampling of the experiences of
the researchers are analyzed to clarify the dynamic and often competing issues
and interactions involved in encouraging hospital-wide research involvement
during periods of organizational growth and change. The model reflects the
simultaneous interaction of organizational, change and collaborative processes
while maintaining the rigor of the research (RCT), and ensuring minimal
disruption to the service agency. Quantitative outcomes of this collaboration are
presented through an analysis of participant involvement on multiple
organizational levels. Recommendations for future collaborative research,
including design and methodological issues and collaborative and change
strategies are offered. The complexity of balancing the necessary trade-offs
required of successful collaborative research are highlighted and will be useful
to those considering and planning future collaborations.
PMID- 10687812
TI - Creating and maintaining 'optimism' in cancer care communication.
AB - This study investigates nurse-patient communication in the cancer care context.
Interviews with nurses and patients about their communication experiences and
audio-recorded nurse-patient conversations were collected and analysed. A theme
of 'optimism' largely manifesting as 'constructive realism' was one of four
features identified by the qualitative analysis. The health professional has
traditionally been viewed as the party with the power and control over
conversation progression and topics. In particular, the superficial, positive and
chatty nature of nurse-patient interaction has often been attributed to a lack of
nurses' communication skills training. This research indicates that both patient
and nurse are active in its construction and argues that the optimistic cheerful
nature of nurse-patient interaction may be better viewed as a jointly produced
institutional feature of cancer care. This paper illustrates and examines some of
the ways this outcome was created and maintained by participants and discusses
the implications of this.
PMID- 10687814
TI - Complexity of the simplest phylogenetic estimation problem.
AB - The maximum-likelihood (ML) solution to a simple phylogenetic estimation problem
is obtained analytically The problem is estimation of the rooted tree for three
species using binary characters with a symmetrical rate of substitution under the
molecular clock. ML estimates of branch lengths and log-likelihood scores are
obtained analytically for each of the three rooted binary trees. Estimation of
the tree topology is equivalent to partitioning the sample space (space of
possible data outcomes) into subspaces, within each of which one of the three
binary trees is the ML tree. Distance-based least squares and parsimony-like
methods produce essentially the same estimate of the tree topology, although
differences exist among methods even under this simple model. This seems to be
the simplest case, but has many of the conceptual and statistical complexities
involved in phylogeny estimation. The solution to this real phylogeny estimation
problem will be useful for studying the problem of significance evaluation.
PMID- 10687813
TI - The xylem of rice (Oryza sativa) is colonized by Azorhizobium caulinodans.
AB - Following inoculation with Azorhizobium caulinodans ORS571 (pXLGD4), lateral root
development of rice and colonization of lateral root cracks by bacteria were
shown to be stimulated by the flavonoid naringenin. Rice seedlings growing
aseptically in the presence of naringenin were inoculated with ORS571 (pXLGD4),
carrying the lacZ reporter gene. By microscopic analysis of sections of
inoculated rice roots, it has been demonstrated that the xylem of rice roots can
be colonized by Azorhizobium caulinodans. We discuss whether this colonization of
the xylem of rice roots by azorhizobia could provide a suitable niche for
endophytic nitrogen fixation.
PMID- 10687815
TI - Gene flow in the European corn borer Ostrinia nubilalis: implications for the
sustainability of transgenic insecticidal maize.
AB - Strategies proposed for delaying resistance to Bacillus thuringiensis toxins
expressed by transgenic maize require intense gene flow between individuals that
grew on transgenic and on normal (referred to as refuges) plants. To investigate
gene flow in the European corn borer, Ostrinia nubilalis (Hubner), the genetic
variability at 29 sampled sites from France was studied by comparing allozyme
frequencies at six polymorphic loci. Almost no deviations from Hardy-Weinberg
expectations occurred, and a high stability of allelic distribution was found
among samples collected in the same site over two or three different generations,
indicating a high stability of the genetic structure over time. The overall
genetic differentiation was low at the region and whole country level, suggesting
a high and homogeneous gene flow. These results are discussed in relation to the
sustainability of transgenic insecticidal maize.
PMID- 10687817
TI - Non-random fitness variation in two populations of Darwin's finches.
AB - Darwinian fitness of an individual is measured by the number of recruits it
contributes to the next generation. We studied variation in fitness among members
of three cohorts of two species of Darwin's finches living on the Galipagos
island of Daphne Major: the medium ground finch (Geospiza fortis) and cactus
finch (Geospiza scandens). Individuals of both species live for up to 16 years.
Variation in fitness was neither random nor heritable. Non-randomness arises as a
result of a few individuals living for an exceptionally long time and breeding
many times. For each cohort, the number of recruits per breeder is strongly
predicted by the number of fledglings per breeder. In turn, the number of
fledglings is strongly predicted by longevity of the breeder. These results
suggest that the most important determinant of fitness is the ability of an
individual to survive to breed in many years. Morphological traits affect this
ability. Although morphological traits are heritable they do not change
unidirectionally because they are selected in opposite directions, and in
different combinations, under fluctuating environmental conditions. Non-random
fitness variation in fluctuating populations implies much smaller genetically
effective sizes than breeding population sizes.
PMID- 10687816
TI - Mild environmental stress elicits mutations affecting fitness in Chlamydomonas.
AB - Cultures of Chlamydomonas were exposed to a range of relatively mild stresses for
a period of 24 h. These stresses comprised high and low temperatures, osmotic
stress, low pH, starvation and toxic stress. They were then allowed to recuperate
for around ten vegetative generations under near-optimal conditions in unmodified
minimal medium. Fitness was then assayed as the rate of division of isolated
cells on agar. We found that there was a strong tendency for stressed cultures to
have lower mean fitness and greater standardized variance in fitness than the
negative controls which had been cultured throughout in unmodified minimal
medium. The same tendency was shown, as expected, by positive controls which
received mutagenic doses of ultraviolet irradiation. We concluded that the most
reasonable interpretation of these observations is that mild stress increases the
genomic rate of mutation. This appears to be the first time that this phenomenon
has been noticed in eukaryotes. The response might be adaptive because lineages
in which higher mutation rates are elicited by stress can be favourably selected
through the production of a few mutants which are fortuitously well adapted to
the stressful environment. Other interpretations are not excluded, however.
Regardless of the mechanism involved, the elevation of mutation rates under
stress will affect the rate of evolutionary response to environmental change and
also the maintenance of sexuality.
PMID- 10687818
TI - Dispersal and extinction in fragmented landscapes.
AB - Evolutionary and population dynamics models suggest that the migration rate will
affect the probability of survival in fragmented landscapes. Using data for
butterfly species in the fragmented British landscape and in immediately
adjoining areas of the European continent, this paper shows that species of
intermediate mobility have declined most, followed by those of low mobility,
whereas high-mobility species are generally surviving well. Compared to the more
sedentary species, species of intermediate mobility require relatively large
areas where they breed at slightly lower local densities. Intermediate mobility
species have probably fared badly through a combination of metapopulation
(extinction and colonization) dynamics and the mortality of migrating individuals
which fail to find new habitats in fragmented landscapes. Habitat fragmentation
is likely to result in the non-random extinction of populations and species
characterized by different levels of dispersal, although the details are likely
to depend on the taxa, habitats and regions considered.
PMID- 10687819
TI - Adaptive significance of male parental care in a monogamous mammal.
AB - Paternal behaviour presumably evolved because male care of young was critical for
offspring survival. We report field evidence indicating that paternal behaviour
enhances offspring survival in a monogamous mammal, the biparental California
mouse, Peromyscus californicus. Male removal resulted in lower offspring survival
in father-absent than in father-present families. New males took up residence
with widowed females, but usually after females had stopped lactating, suggesting
that the importance of the father is not primarily protection against
infanticidal intruders but rather direct care of young.
PMID- 10687820
TI - The importance of stable schooling: do familiar sticklebacks stick together?
AB - Preferences for rejoining shoals composed of familiar individuals have recently
been documented in a variety of small, shallow-water fish species. Such
preferences are assumed to be adaptive, since familiar groups have improved anti
predator defences and more stable dominance hierarchies. However, the design of
these studies may have created conditions that elevate preferences for familiar
individuals. Furthermore, in natural habitats, where significant opportunities
for inter-shoal transfer may exist, it is unclear whether shoals stay together
long enough for such preferences to develop. Here we present the results of a
laboratory study examining whether prior familiarity influences the subsequent
shoal composition of sticklebacks (Gasterosteus aculeatus) allowed to re-assort
freely in a large arena tank. We show that fish from different familiarity groups
associate with familiar conspecifics significantly more than predicted by a model
of random assortment, suggesting that even when there is ample opportunity for
inter-group transfer, shoal composition can remain stable. We discuss the
phenomena that may lead to the formation of familiar groups in natural habitats.
In addition, we suggest that familiarity benefits may reduce the relative value
of transferring to otherwise more attractive (e.g. larger or more phenotypically
matched) groups, and thereby stabilize shoal structure.
PMID- 10687821
TI - Foraging rate versus sociality in the starling Sturnus vulgaris.
AB - It is well established that social conditions often modify foraging behaviour,
but the theoretical interpretation of the changes produced is not
straightforward. Changes may be due to alterations of the foraging currency (the
mathematical expression that behaviour maximizes) and/or of the available
resources. An example of the latter is when both solitary and social foragers
maximize rates of gain over time, but competition alters the behaviour required
to achieve this, as assumed by ideal free distribution models. Here we examine
this problem using captive starlings Sturnus vulgaris. Subjects had access to two
depleting patches that replenished whenever the alternative patch was visited.
The theoretical rate-maximizing policy was the same across all treatments, and
consisted of alternating between patches following a pattern that could be
predicted using the marginal value theorem (MVT). There were three treatments
that differed in the contents of an aviary adjacent to one of the two patches
(called the 'social' patch). In the control treatment, the aviary was empty, in
the social condition it contained a group of starlings, and in a non-specific
stimulus control it contained a group of zebra finches. In the control condition
both patches were used equally and behaviour was well predicted by the MVT. In
the social condition, starlings foraged more slowly in the social than in the
solitary patch. Further, foraging in the solitary patch was faster and in the
social patch slower in the social condition than in the control condition.
Although these changes are incompatible with overall rate maximization (gain rate
decreased by about 24% by self-imposed changes), if the self-generated gain
functions were used the MVT was a good predictor of patch exploitation under all
conditions. We discuss the complexities of nesting optimal foraging models in
more comprehensive theoretical accounts of behaviour integrating functional and
mechanistic perspectives.
PMID- 10687822
TI - The evolution of song repertoires and immune defence in birds.
AB - Song repertoires (the number of different song types sung by a male) in birds
provide males with an advantage in sexual selection because females prefer males
with large repertoires, and females may benefit because offspring sired by
preferred males have high viability. Furthermore, males with large repertoires
suffer less from malarial parasites, indicating that a large repertoire may
reflect health status. We hypothesize that sexual selection may cause a
coevolutionary increase in parasite virulence and host immune defence because
sexual selection increases the risk of multiple infections that select for high
virulence. Alternatively, a female mate preference for healthy males will affect
the coevolutionary dynamics of host-parasite interactions by selecting for
increased virulence and hence high investment by hosts in immune function. In a
comparative study of birds, repertoire size and relative size of the spleen,
which is an important immune defence organ, were strongly, positively correlated
accounting for almost half of the variance. This finding suggests that host
parasite interactions have played an important role in the evolution of song
repertoires in birds.
PMID- 10687823
TI - Predator avoidance and immune defence: costs and trade-offs in snails.
AB - Organisms are often confronted by both predators and pathogens. Defending against
such widely divergent enemies requires more than one type of defence. Multiple
defences, however, raise the possibility of trade-offs among defences. We tested
for such trade-offs by manipulating the level of predator-avoidance behaviour and
immune function in the freshwater snail Lymnaea stagnalis (Gastropoda:
Pulmonata). Our results show that predator avoidance and immune function had
clear costs in terms of reproduction and survival. Further, we show that
increased levels of predator-avoidance behaviour reduced the snails' ability to
defend against potential pathogens. Predator-avoidance behaviour may thus have
the additional indirect cost of reduced immunocompetence and increased
susceptibility to pathogens. Our results suggest that ecological factors (e.g.
predator density) may considerably modify the expression and costs of immune
defences.
PMID- 10687824
TI - Density-dependent prophylaxis in the mealworm beetle Tenebrio molitor L.
(Coleoptera: Tenebrionidae): cuticular melanization is an indicator of investment
in immunity.
AB - If there are costs involved with the maintenance of pathogen resistance, then
higher investment in this trait is expected when the risk of pathogenesis is
high. One situation in which the risk of pathogenesis is elevated is at increased
conspecific density. This paper reports the results of a study of density
dependent polyphenism in pathogen resistance and immune function in the mealworm
beetle Tenebrio molitor. Beetles reared at high larval densities showed lower
mortality when exposed to a generalist entomopathogenic fungus and a higher
degree of cuticular melanization than those reared solitarily. The degree of
cuticular melanization was a strong indicator of resistance, with darker beetles
being more resistant than lighter ones regardless of rearing density. No
differences were found between rearing densities in the levels of phenoloxidase,
an enzyme key to the insect immune response. The results show that pathogen
resistance is phenotypically plastic in T. molitor, suggesting that the
maintenance of this trait is costly.
PMID- 10687825
TI - Intra-host competition between nef-defective escape mutants and wild-type human
immunodeficiency virus type 1.
AB - Various forms of nef genes with deletions at conserved positions along the
sequence have been reported to persist in human immunodeficiency virus type 1
infected patients. We investigate the forces maintaining such variants in the
proviral population. The main selection pressures are preservation of function
and host immune response. The crippled Nef protein might have fewer epitopes, and
as such be less visible to the specific immune response, but it will lose some
function. Does a trade-off between avoidance of the immune response and loss of
function explain the dynamics of the crippled virus found in the patients? To
answer this question, we formulated a deterministic model of the virus-host
interactions. We found that when the crippled protein presents few epitopes and
suffers little loss of function, the two viral types can coexist. Otherwise, the
wild-type comes to prevail. The mutant form might initially dominate, but as the
selective pressure by the CD84+ T cells decreases over the course of infection,
the advantage for the crippled form of losing epitopes disappears. Hence, we go
from a situation of coexistence of wild-type and mutant, to a situation of only
full-length nef. The results are discussed in the context of the suggested use of
live attenuated vaccines having deletions in nef.
PMID- 10687826
TI - Empirical evidence for differential organ reductions during trans-oceanic bird
flight.
AB - Since the early 1960s it has been held that migrating birds deposit and use only
fat as fuel during migratory flight, with the non-fat portion of the body
remaining homeostatic. Recent evidence from field studies has shown large changes
in organ sizes in fuelling birds, and theory on fuel use suggests protein may be
a necessary fuel during flight. However, an absence of information on the body
condition of migrants before and after a long flight has hampered understanding
of the dynamics of organs during sustained flight. We studied body condition in a
medium-sized shorebird, the great knot (Calidris tenuirostris), before and after
a flight of 5400 km from Australia to China during northward migration. Not only
did these birds show the expected large reduction in fat content after migration,
there was also a decrease in lean tissue mass, with significant decreases in
seven organs. The reduction in functional components is reflected in a lowering
of the basal metabolic rate by 42% [corrected]. Recent flight models have tried
to separate the 'flexible' part of the body from the constant portion. Our
results suggest that apart from brains and lungs no organs are homeostatic during
long-distance flight. Such organ reductions may be a crucial adaptation for long
distance flight in birds.
PMID- 10687827
TI - An extension to the hypothesis of the asynchrony of visual consciousness.
AB - An existing hypothesis states that visual consciousness is made up of
'microconsciousnesses' occurring asynchronously in several sites of the visual
system of the brain with no need for direct means of binding. We extend this
hypothesis to define what qualifies a neural activity for generating an element
of consciousness to distinguish it from one that does not. We argue that, for
these separate neural activities to represent elements of a compound sense of
consciousness, they each need the support of sites that unconsciously process an
important attentional referent and that it is the commonality of such referents
in differing sites which bring the microconsciousnesses together. We consider the
broader implications of this extended hypothesis for other sensory modalities and
mental imagery.
PMID- 10687828
TI - Seminal fluid causes temporarily reduced egg hatch in previously mated females.
AB - In Drosophila, male accessory gland fluid (seminal fluid) has multiple effects on
the female's reproductive efficiency. Here, we show the effect of seminal fluid
on rate of egg hatch immediately following mating. Singly mated females were
remated to two classes of sterile males, one with seminal fluid and one without
seminal fluid. Transfer of seminal fluid results in a strong reduction in egg
hatch shortly after the mating. Also, it is shown that remating with normal males
causes an immediate reduction of egg hatch followed by recovery to normal egg
hatch. In all cases, unhatched eggs contained no sperm. These results are
consistent with a role for seminal fluid in sperm competition, mediated by
incapacitation or inefficient use of resident sperm.
PMID- 10687829
TI - Intrapartum fetal distress and magnesium sulfate.
AB - OBJECTIVE: Intrapartum fetal distress is an obstetric emergency traditionally
managed by immediate delivery by either the vaginal route or cesarean section.
However, there is usually time to attempt intrauterine resuscitation. The purpose
of this study was to report the utilization of magnesium sulfate for intrauterine
resuscitation. METHOD: Twenty-one fetuses received magnesium sulfate 4-g
intravenous bolus in mothers awaiting cesarean section for fetal distress in the
labor room of the Complejo Hospitalario Metropolitano de la Caja de Seguro Social
de Panama, from March through August 1997. Fetal distress in labor was defined as
the presence of repetitive late decelerations, persistent loss of baseline
variability, severe variable decelerations, or bradycardia. RESULTS: Twenty-one
fetuses received magnesium sulfate 4-g intravenous bolus in mothers awaiting
cesarean section for fetal distress. Uterine activity ceased in seven patients,
diminished in 13 patients and did not change in one. In all cases, but one, there
was recovery of the FHR within 4 min; furthermore there was rose reactive of FHR
in nine patients. The 1-min Apgar scores were 7 or above in 18 cases and the 5
min Apgar scores were 7 or above in 20 patients. CONCLUSIONS: In summary,
magnesium sulfate may be useful in the management of acute intrapartum fetal
distress when there is evidence of increased uterine activity.
PMID- 10687830
TI - Antenatal ultrasonography for breech delivery.
AB - OBJECTIVE: We studied the role of sonography in the management of 370 breech
presentations > or = 34 weeks maturity. METHOD: 185 cases had sonographic
confirmation of breech presentation prior to the delivery at the Korle Bu
Teaching Hospital. A control group of 185 cases did not have prior scanning.
RESULTS: Significantly more elective cesarean sections were done in the study
group, while the control group had more emergency sections (P = 0.008), and had
more traumatic delivery. Birth asphyxia and perinatal mortality were
significantly more common in the control group (P < 0.05). CONCLUSION: Sonography
done before delivery improved neonatal outcome in breech presentation > or = 34
weeks maturity.
PMID- 10687831
TI - Episiotomy in Nigeria.
AB - OBJECTIVE: To review the incidence and complications associated with episiotomy
and perineal tears at the University of Benin Teaching Hospital, Benin City,
Nigeria. METHOD: A retrospective review of all vaginal births conducted in the
hospital between January 1997 and December 1998 was undertaken. Vaginal births
(1345) were reviewed. RESULT: The prevalence of episiotomy in the hospital during
the period was 46.6%. Over 90% of primigravid parturients had episiotomy. The
incidence of episiotomy decreased with increasing parity, while the incidence of
spontaneous vaginal tears increased with parity. As compared with perineal tears,
episiotomy was associated with a statistically significant increased risk of
wound breakdowns requiring secondary resuturing. When controlled for parity,
breech births, forceps and vacuum delivery were more likely to lead to
episiotomy, compared to spontaneous vertex delivery occurring at term.
CONCLUSION: A policy of systematic reduction in the incidence of episiotomy can
be pursued in this hospital. Greater attention needs to be paid to selection of
women to undergo episiotomy, the prevention of spontaneous perineal tears and the
care of episiotomy wounds in this institution.
PMID- 10687832
TI - Screening for cervical neoplasia during pregnancy.
AB - OBJECTIVE: To evaluate cytology as a screening method for cervical neoplasia in
pregnancy and to compare it with cervicography and the acetic acid test (AAT).
METHODS: In a large antenatal clinic in South Africa, 842 women were screened
utilizing cytology, cervicography and the acetic acid test simultaneously. The
proportion of positive results of the different tests were compared and the
agreement calculated by the kappa statistic. RESULTS: The mean age of the women
was 27 years, and 12.5% smoked. Cytological smears were abnormal (low-grade
squamous intra-epithelial lesion and higher degrees of abnormality) in 1.4% of
cases, cervicography in 6.3% and the AAT in 14.3% (P = 0.5400). Kappa values were
as follows: cytology vs. cervicography 0.01, cytology vs. AAT 0.0 and
cervicography vs. AAT 0.2. CONCLUSIONS: As a result of cytology's rather low
yield and the small measure of agreement between the tests, cytology should be
supplemented by an additional screening test in pregnancy.
PMID- 10687833
TI - Treatment outcomes for squamous intraepithelial lesions.
AB - OBJECTIVE: To assess the effectiveness of cone biopsy, cryotherapy, laser
ablation and the loop electrosurgical procedure in the treatment of squamous
intraepithelial lesions. METHOD: Systematic review of randomized controlled
trials in subjects who underwent treatment of low- and high-grade squamous
intraepithelial lesions with these modalities. Main outcome measures included the
following: percent resolution and persistence of a lesion and notable
complications for each procedure. RESULT: Pooled rates of resolution for low
grade, high-grade, or combined squamous intraepithelial lesions were similar
across the different treatment modalities (range 85.2-94.7%), with substantial
overlap among the 95% confidence intervals. Significant hemorrhage occurred most
frequently in subjects who received cone biopsy (4.6%) (95% CI: 2.15, 6.99),
followed by laser ablation (1.75%) (95% CI: 0.70, 2.81), and LEEP (1.35%) (95%
CI: 0.24, 2.47). No hemorrhages were reported among subjects who received
cryotherapy. Study sample sizes were relatively small. There were no reported
cases of progression to invasive cancer, but duration of follow-up (median follow
up time for all eligible studies = 12 months) was not sufficient to evaluate long
term outcomes. CONCLUSIONS: There were no substantive differences in outcomes
regarding persistence and resolution in the treatment of squamous intraepithelial
lesions for subjects receiving cone biopsy, cryotherapy, laser ablation, or LEEP.
PMID- 10687834
TI - The effects of systemic hormonal replacement therapy on the skin of
postmenopausal women.
AB - OBJECTIVE: The aim of this study was to determine the effects of hormonal
replacement therapy on the skin of postmenopausal women. METHOD: Forty-one
postmenopausal women were randomly allocated to receive either hormonal
replacement (valerate estradiol--2 mg/day for 21 days and cyproterone acetate--1
mg/day for 10 days) or placebo, both in a cyclic scheme for 6 months. Neither
patients nor investigators were aware of the group allocation. Histologic changes
were evaluated by skin biopsy of the left upper arm at baseline and after 6
months of treatment, utilizing computerized image analysis to assess the ratio
area of epidermis/basement membrane length (AE/BML), ratio area of
keratin/basement membrane length (AK/BML) and collagen and elastic fibers
content. RESULT: Collagen content of the left upper arm increased after 6 months
of treatment only in the hormonal group (+6.49%; P < 0.05). Other parameters did
not present any significant alteration after treatment in both groups.
CONCLUSION: Hormonal replacement for climacterics increases skin collagen
content.
PMID- 10687835
TI - Uterine rupture in a multiparous woman during labor induction with oral
misoprostol.
AB - A multigravida with gestational diabetes, mild pregnancy-induced hypertension and
a previous curettage received four doses of misoprostol (100 microg) at three
hourly intervals for induction of labor at term. Vaginal delivery of a live
healthy baby occurred 1 h after the fourth dose. Hindwaters were bloodstained.
Three hours later, she had excessive bleeding. Examination showed that the left
lateral uterine wall had ruptured. She recovered after hysterectomy and blood
transfusions.
PMID- 10687836
TI - Conditions influencing blood pressures in healthy gravidas.
AB - The use of 24-h monitoring devices in healthy gravidas confirmed the suspicion
that temporary blood pressure elevations relate to ambulation and to emotional
upheaval, while the lowest recordings are associated with periods of rest.
PMID- 10687837
TI - Treatment for repeat tubal ectopic pregnancy.
PMID- 10687838
TI - Emergency postpartum hysterectomy in women with placenta previa and prior
cesarean section.
AB - The combination of prior cesarean section and placenta previa is an especially
ominous risk factor for emergency postpartum hysterectomy and life-threatening
bleeding following placental removal.
PMID- 10687839
TI - Pregnancy following tubal sterilization: an 11-year survey.
PMID- 10687840
TI - Is routine antenatal screening for syphilis useful?
AB - The incidence of positive antenatal syphilis serology is low in Benin City.
Routine serological screening should continue with the inclusion of confirmatory
treponemal antigen tests.
PMID- 10687841
TI - Trends in epidemiology of cervical cancer in Thrace, Greece.
PMID- 10687842
TI - Voluntary and involuntary sterilization: denials and abuses of rights.
AB - Laws that allow competent persons to make free and informed decisions for
sterilization serve their entitlements to reproductive choice. Laws that allow
others to consent to sterilization of disadvantaged persons who cannot freely
consent risk oppression and denial of human rights. Laws that prohibit competent
persons' choices for their own sterilization are comparably oppressive and
violative of human rights to decide whether and how often to have children.
Whether laws approach sterilization as a procedure done for patients, or to
patients, is often ambivalent. Details of laws may indicate their liberating and
oppressive potential. Programs offering inducements to persons to be sterilized
may assist those who are disadvantaged to achieve their goals, but may appear to
coerce those who, through poverty or dependency, cannot resist the inducement.
PMID- 10687843
TI - ACOG committee opinion. Quality of laboratory and imaging services: physician
responsibility in the age of managed care. Number 222, October 1999. Committee on
Practice Management. Committee on Professional Liability. American College of
Obstetricians and Gynecologists.
PMID- 10687844
TI - ACOG committee opinion. First-trimester screening for fetal anomalies with nuchal
translucency. Number 223, October 1999. Committee on Genetics. American College
of Obstetricians and Gynecologists.
PMID- 10687845
TI - ACOG committee opinion. Tamoxifen and the prevention of breast cancer in high
risk women. Number 224, October 1999. Committee on Gynecologic Practice. American
College of Obstetricians and Gynecologists.
PMID- 10687846
TI - Oocyte-expressed TGF-beta superfamily members in female fertility.
AB - Folliculogenesis is regulated by the interplay of extraovarian and intraovarian
factors, and the importance of each type of regulation varies depending on the
developmental stage of the follicle. Preantral follicle development is regulated
predominantly by factors produced locally within the ovary and within the
follicle itself. The oocyte has been shown to produce soluble factor(s), which
regulate a number of processes in follicular development, including cumulus
expansion in the periovulatory period. Members of the TGFbeta superfamily are
potent regulators of cell proliferation and differentiation in a number of organ
systems, and three members, growth differentiation factor 9 (GDF-9), bone
morphogenetic protein 15 (BMP-15) and BMP-6 are expressed by the oocyte and may
mediate effects attributed to the oocyte. Based on knockout mouse models BMP-6
does not play an essential role in ovarian function, but GDF-9 is absolutely
required for preantral follicle development. GDF-9 also alters the periovulatory
expression of granulosa cell genes and stimulates cumulus expansion. Although BMP
15 is expressed identically to GDF-9, its role in regulating ovarian function is
still unknown. This review examines the similarities and differences in sequence,
expression, and function of the oocyte-expressed TGFbeta family members with
respect to regulating folliculogenesis.
PMID- 10687847
TI - Osteocyte function, osteocyte death and bone fracture resistance.
AB - The function of the most numerous cell in bone, the osteocyte, has until recently
been mysterious and at times controversial. There is now an emerging consensus
that osteocytes modulate signals arising from mechanical loading and so direct
the appearance and disappearance of bone tissue at the microscopic level, which
allows bone as an organ both to grow and to adapt efficiently to the body's
mechanical needs for strength with lightness. Osteocytes appear to use some
molecular signalling pathways that are familiar from other tissues, such as the
generation of nitric oxide and prostaglandins as well as directing cell-cell
communication via gap junctions. They may also direct the removal of damaged or
redundant bone through mechanisms linked to their own apoptosis or via the
secretion of specialised cellular attachment proteins such as osteopontin.
Osteocytes possess receptors for parathyroid hormone/parathyroid hormone related
peptide and both oestrogen receptors alpha and beta. They also express molecules
which in nerve cells are involved with glutamate neuro-transmission. At least
some of these receptors and their ligands may regulate osteocyte apoptosis and
modulate osteocyte signalling.
PMID- 10687848
TI - Cloning and characterization of a novel retinoid-inducible gene 1(RIG1) deriving
from human gastric cancer cells.
AB - Retinoids exert wide-spectrum anti-tumor activities, which are mediated via the
induction of growth arrest, differentiation or apoptosis. To determine whether
the effects of retinoids are mediated by specific gene activation or repression,
SC-M1 CL23 gastric cancer cells, pretreated with either vehicle alone or all
trans retinoic acid (10 microM) for 1 day, were analyzed using the technique of
differential display. A novel retinoid-inducible gene 1 (RIG1) was isolated. The
full-length RIG1 cDNA contained 768 base pairs and encoded a protein of 164 amino
acids with a molecular weight of 18 kDa. The RIG1 gene was ubiquitously expressed
in normal tissue, and its expression was positively associated with cellular
density. Nucleotide sequence analysis demonstrated that the RIG1 gene was similar
to a recently-isolated TIG3 gene, and displayed 54% nucleotide sequence homology
with a type II tumor suppressor gene H-REV-107-1. RIG1 cDNA, however, contained
an extra 32 base pairs located at its 5' end and revealed three base pair
differences for the remaining sequences leading to two amino acids substitution
between the two encoded proteins. All-trans retinoic acid increased the level of
RIG1 mRNA in a time- and concentration-dependent manner in SC-M1 CL23 gastric
cancer cells. This was not observed for the H-REV-107-1 gene. The RIG1 regulation
was related to cellular retinoid sensitivity. Both retinoic acid receptor alpha-
and retinoic acid receptor gamma-selective agonists increased RIG1 mRNA level,
and the retinoid x receptor-selective agonist potentiated this regulation. In
conclusion, the cDNA of a novel retinoid-inducible gene RIG1 has been cloned.
This gene is regulated by retinoic acid through the heterodimer of retinoic acid
receptor and retinoid x receptor.
PMID- 10687849
TI - Mechanisms underlying the steroidogenic synergy of insulin and luteinizing
hormone in porcine granulosa cells: joint amplification of pivotal sterol
regulatory genes encoding the low-density lipoprotein (LDL) receptor,
steroidogenic acute regulatory (stAR) protein and cytochrome P450 side-chain
cleavage (P450scc) enzyme.
AB - Growth of ovarian Graafian follicles and cytodifferentiation of granulosa and
theca cells are regulated by gonadotropins, sex steroids and peptidyl growth
factors. For example insulin and intraovarian insulin-like growth factor type I
(IGF-I) may amplify the actions of both follicle stimulating hormone (FSH) and
luteinizing hormone (LH) in promoting biochemical luteinization and enhancing
steroidogenesis. To explore further the notion of interactions between
insulinomimetic peptides and LH and to examine the associated mechanisms, we have
established porcine granulosa cells in monolayer culture for 48 h in 3% serum
with insulin (1 microg/ml), estradiol (0.5 microg/ml), and follicle stimulating
hormone (FSH, 5 ng/ml) to allow cell anchorage, facilitate in vitro
cytodifferentiation and confer LH responsiveness. To limit any carry-over effects
of serum, granulosa cells were stabilized overnight in serum-free medium. Studies
were then initiated to assess the impact of insulin on the dose-responsive
actions of LH. A maximally effective concentration of insulin (1 microg/ml)
synergistically augmented LH's dose-dependent ampilification of progesterone and
cAMP accumulation; viz. by approximately twofold (progesterone) and approximately
2.5-fold (cAMP) above that observed in maximally LH-stimulated cultures (P <
0.001). Mechanistically, insulin significantly enhanced the sensitivity of
granulosa cells to LH's drive of cAMP accumulation [ED50 for LH 61 +/- 14 ng/ml
(control) vs. 10 +/- 1.0 ng/ml (insulin) (P < 0.01)]. Insulin also augmented the
maximal stimulatory effect of LH; i.e. LH efficacy rose from 6.5 +/- 0.4 to 17 +/
1.4 (pmole cAMP/microg DNA/48 h; P < 0.001). Insulin dose-response analysis
showed that insulin alone minimally elevated basal, but significantly heightened
LH's stimulation of progesterone and cAMP accumulation at (insulin)
concentrations as low as 3-10 ng/ml. The molecular mechanisms underlying insulin
and LH's synergy were assessed by RNase protection assays with (porcine) cRNA
probes encoding the low density lipoprotein receptor (LDL-R), Steroidogenic Acute
Regulatory Protein (StAR), P450 cholesterol sidechain cleavage enzyme (P450scc)
and (as a possible negative control) Sterol Carrier Protein 2 (SCP-2) [data
normalized to constitutive 18S rRNA]. Non linear least-squares analysis was
applied to confirm or refute an hypothesis of interactive synergy between LH and
insulin on gene expression. LH and insulin alone exerted no effect on StAR
message accumulation, and LH alone minimally stimulated P450scc and LDL-R mRNA's
accumulation at 48 h. In contrast, insulin in combination with LH augmented StAR
mRNA concentrations by approximately 5-10-fold and stimulated LDL-R message
levels by threefold above the respective maximally LH-driven values (P < 0.01).
Maximal P450scc mRNA expression was enhanced twofold by cotreatment with LH and
insulin compared with maximal LH-treated cultures. In contrast SCP-2 mRNA
accumulation remained unaffected by any treatment. In summary, we have used a
serum-free, in vitro differentiated porcine granulosa cell culture system to
assess regulatory interactions between the disparate first messengers, LH and
insulin. We observe marked LH-insulin steroidogenic synergy after 48 h of joint
hormonal stimulation, and further clarify that the mechanism(s) of synergy
include augmentation of cAMP production and increased steady-state concentrations
of transcripts of key sterol-regulatory genes; namely, LDL-R, StAR, and P450scc,
but not SCP-2. Since the encoded products of these genes variously control sterol
substrate uptake, delivery to and utilization in mitochondrial steroidogenesis,
we speculate that the concerted actions of insulin-like peptides and LH may
contribute to steroidogenic differentiation during the later stages of follicular
maturation and the granulosa-luteal cell transition.
PMID- 10687850
TI - Expression of GnRH receptor gene in human ectopic endometrial cells and
inhibition of their proliferation by leuprolide acetate.
AB - The present study was conducted to investigate whether GnRH-receptor (GnRH-R)
gene is expressed in endometriosis ovarian implants and whether a GnRH-analogue
(GnRH-a) may exert an effect on endometriosis cell proliferation in vitro. The
presence of GnRH-R transcripts in ovarian endometriosis cells was assessed by
reverse transcription-polymerase chain reaction (RT-PCR) and further confirmed by
Southern blot analysis. GnRH-R mRNA was detected in all the 13 samples examined.
In contrast, GnRH-R transcripts were not detectable in endometriosis-free
peritoneal tissue. In the second part of the study, endometriosis cells were
cultured for 9 days with different doses of leuprolide acetate (ranging from 0 to
10(-5) M). In 4 out of 13 cases, a significant anti-proliferative effect was
observed at doses of leuprolide acetate ranging from 10(-9) to 10(-5) M. In one
case, a significant inhibition of cell proliferation was observed only at 10(-5)
M leuprolide acetate concentration. In contrast, the GnRH-a did not affect cell
growth, regardless of the expression of GnRH-R transcripts and the given doses,
in the remaining 8 experiments. To date, this is the first evidence indicating
that GnRH-R mRNA is expressed in human ovarian endometriomas. Moreover, the
inhibition of endometriosis cell proliferation induced by the GnRH-a in vitro
suggests that, at least in some cases, this compound might exert a direct effect
on endometriosis lesions.
PMID- 10687852
TI - EGF activates highly selective estrogen-responsive reporter plasmids by an ER
independent pathway.
AB - Epidermal growth factor (EGF) mimics the effects of estrogen on some cells,
suggesting that it may activate the estrogen receptor (ER). We examined the
ability of EGF to increase expression of several different estrogen-responsive
luciferase reporters in MCF-7 breast cancer cells. Although EGF increased
reporter activity, this effect was not inhibited by estrogen antagonists and was
not dependent on estrogen response elements in the reporter plasmid. Similar
results were obtained in BG-1 (ovarian) and Ishikawa (uterine) cells. In ER
negative JEG-3 cells, EGF, but not estradiol, increased reporter activity in the
absence of transfected ER. The estrogen antagonist ICI 182780 blocked the ability
of estradiol, but not EGF, to stimulate proliferation of T47D breast cancer
cells, suggesting that the mitogenic effects of EGF are not mediated by ER. EGF
does not appear to activate ER-mediated transcription in these experimental
systems, although crosstalk between the estrogen and EGF signaling pathways may
occur by other mechanisms.
PMID- 10687851
TI - Effect of cyclic adenosine 3',5'-monophosphate and protein kinase A on ligand
dependent transactivation via the vitamin D receptor.
AB - We examined the effects of cyclic adenosine 3',5'-monophosphate (cAMP) and
protein kinase A (PKA) on the ligand-dependent transactivation mediated via the
1,25-dihydroxyvitamin D3 (1,25(OH)2D3) receptor (VDR). A human VDR expression
plasmid was transfected into HeLa, Saos-2 and MG63 cells with a luciferase
reporter gene construct containing the vitamin D responsive element. With the
addition of 0.5 mM 8 bromo-cAMP, the response to 1,25(OH)2D3 was suppressed to 61
and 78% in the HeLa and Saos-2 cells, respectively. The suppressive effect of 8
bromo-cAMP was observed without the introduction of the VDR expression plasmid in
the MG63 cells. In the HeLa cells the co-expression of PKA reduced the ligand
inducible transactivation to 61% and the fold induction by 1,25(OH)2D3 to 89% of
that without PKA. The CREB binding protein (CBP) was recently reported to
integrate the intracellular signals via the cAMP/PKA cascade and nuclear hormone
receptors. However, the suppressive effect of cAMP was not influenced by the co
expression of CBP. Lastly, we introduced point mutations at possible PKA
phosphorylation sites into the VDR expression vector at serine-172 and threonine
175, but both mutant receptors still exhibited reduced transactivation with the
co-expression of PKA. These results indicate that the phosphorylation of proteins
other than the VDR may also be involved in the inhibitory effect mediated by the
cAMP/PKA cascade.
PMID- 10687853
TI - Links between Fer tyrosine kinase expression levels and prostate cell
proliferation.
AB - In our cloning strategy to identify tyrosine kinases implicated in the regulation
of prostate growth, the dog fer cDNA was obtained and shown to be highly
homologous to known fer cDNAs. Using a polyclonal Fer antibody directed against a
C-terminal peptide, we studied its associations with cortactin, beta-catenin and
p120Cas in human prostate carcinoma PC-3 cells. In contrast to previous reports,
no interactions were observed. To assess its functional role, fer cDNA constructs
were transfected in PC-3 cells. Antisense clones exhibiting a marked diminution
of Fer expression had a reduced growth rate (doubling time of 29 vs. 42 h) and
were unable to form colonies in soft agar. In agreement with these results, Fer
protein expression was linked to human prostatic proliferative diseases, with
enhanced levels in extracts from cancer tissues as compared to those from normal
and hyperplastic ones, and was also expressed in the human prostate carcinoma
cell lines DU145 and LNCaP. In the dog model, Fer expression was up-regulated in
dividing versus resting prostate epithelial cells in vitro, and also in vivo when
basal cell hyperplasia and metaplasia was induced by estrogen after castration.
Minimal effects were observed when renewing the luminal epithelium with
androgens. Taken together, these results show that Fer expression is associated
with prostate cell proliferation and enhanced in prostate cancer.
PMID- 10687854
TI - Tumour necrosis factor-alpha exerts dual effects on human adipose leptin
synthesis and release.
AB - The acute and chronic effects of tumour necrosis factor-alpha (TNF-alpha) on
leptin production by human preadipocytes, differentiated preadipocytes, and
mature adipocytes have been examined by competitive RT-PCR of leptin mRNA and by
western blotting. In preadipocytes, secreted leptin was detectable after 5-day
incubation in differentiation medium and this increased 4-fold by day 20. TNF
alpha blocked leptin synthesis during differentiation. In differentiated
preadipocytes and mature adipocytes, TNF-alpha treatment resulted in time
dependent decreases in mRNA for leptin and glycerol-3-phosphate dehydrogenase
(G3PD). In contrast, TNF-alpha (4-8-h treatment) resulted in a 4-fold increase in
leptin release. This effect was lost at 24 h and leptin accumulation in culture
medium was decreased 24-48 h after TNF-alpha addition. We conclude that TNF-alpha
stimulates the release of preformed leptin from human mature adipocytes and
existing differentiated preadipocytes, which may contribute to obesity/infection
linked hyperleptinemia, and that TNF-alpha inhibits leptin synthesis via
inhibition of preadipocyte differentiation and induction of adipocyte
dedifferentiation.
PMID- 10687855
TI - Mouse growth hormone transcription factor Zn-16: unique bipartite structure
containing tandemly repeated zinc finger domains not reported in rat Zn-15.
AB - Rat Zn-15 is a transcription factor activating GH gene expression by synergistic
interactions with Pit-1, named for 15 DNA-binding zinc fingers, including fingers
IX, X, and XI that are responsible for GH promoter binding. In this study, a
mouse cDNA for Zn-15 was characterized. The predicted 2192-amino acid mouse
protein is 89% identical to rat (r) Zn-15 overall, and is 97% similar in the C
terminal domain necessary for binding the GH promoter. However, the mouse cDNA
encodes 16 zinc fingers, and sequences of rZn-15 pituitary cDNAs were the same as
the mouse (m) Zn-16; the rat sequence in GenBank has a one nucleotide offset of a
17-bp segment in the finger V region. The mouse and corrected rat sequences
contain four tandemly repeated fingers in the N-terminus, each separated by seven
amino acids, typical of zinc finger proteins of the transcription factor IIIA
type. Analysis of mZn-16 expression by RT-PCR showed that the mRNA is, produced
at similar levels in normal and GH-deficient Ames dwarf (Prop-1 ) mouse
pituitaries at postnatal day 1. Mouse Zn-16 mRNA also was detected by
ribonuclease protection assay in the pre-somatotrophic mouse cell line GHFT1-5.
The Zn-16 protein is bipartite in that the N-terminal half displays tandem
spacing typical of most zinc finger proteins, while the C-terminal portion
contains long linkers between fingers that cooperatively bind to a DNA response
element. Expression in early postnatal pituitary and in pre-somatotrophic cells
suggests that Zn-16 could play a role in pituitary development prior to
somatotroph differentiation.
PMID- 10687856
TI - Expression and regulation of melanocortin receptor-5 (MC5-R) in the bovine
adrenal cortex.
AB - Among the five members of the melanocortin receptor (MC-R) family, MC2 and MC5
are expressed in peripheral tissues. The receptor MC2 (ACTH receptor) almost
exclusively expressed in the adrenal cortex whereas MC5-R is expressed in several
organs including the adrenal cortex. Both receptors bind ACTH and activate
adenylate cyclase. The aim of this work was to study the spatial distribution of
MC5-R among the different zones of the bovine adrenal cortex and to analyze the
regulation of its expression by its own ligands, ACTH and alpha-MSH and by
angiotensin II (AII). Using semi-quantitative reverse transcriptase-polymerase
chain reaction (RT-PCR) analysis and RNase protection assay, MC5-R was detected
only in the glomerulosa zone whereas MC2-R was present in both glomerulosa and
fasciculata zones of adult adrenal cortex. Treatments by ACTH, alpha-MSH, or AII
increased the MC5-R mRNA level in glomerulosa cells by factors 7, 5, and 4.5,
respectively. However, although potentially regulated by hormones, MC5-R is
expressed at a level at least 100 times less than MC2-R, suggesting that MC5-R
expression might only be at trace levels in grown adults, but could be much
higher during embryogenesis.
PMID- 10687857
TI - Resistance to thyroid hormone (RTH) syndrome reveals novel determinants
regulating interaction of T3 receptor with corepressor.
AB - Thyroid hormone receptors (T3Rs) both repress and activate gene transcription by
interacting with auxiliary factors denoted corepressors and coactivators.
Resistance to thyroid hormone (RTH) syndrome in humans is manifested as a failure
to respond properly to elevated circulating thyroid hormone. RTH syndrome has
been mapped to T3Rbeta mutations that alter the transcriptional properties of the
receptor, resulting in a dominant negative phenotype. We report here a
characterization of a series of RTH mutant T3Rs that exhibit unusual interactions
with corepressor. Two mutations in receptor helix 11 (delta430, delta432) greatly
enhance the ability of the mutant receptors to bind to corepressor. A distinct
mutation, V264D, in an 'omega loop' region of the receptor, impairs corepressor
release but does not fully eliminate the ability to recruit coactivator. These
mutations reveal novel determinants that regulate the interaction of the T3R with
important ancillary cofactors, and that are disrupted in a human endocrine
disease.
PMID- 10687858
TI - An alternatively spliced rat mineralocorticoid receptor mRNA causing truncation
of the steroid binding domain.
AB - We attempted to clone the putative 11-dehydrocorticosterone receptor by RT-PCR
with two degenerate primers from highly homologous regions of the DNA and steroid
binding domains of the receptor subfamily. In doing so, we have identified an
alternatively spliced variant mRNA of the rat mineralocorticoid (MR) with a ten
bp deletion in the C-terminal steroid binding domain. This deletion results in a
truncated MR receptor of 807 amino acids in comparison to the wild type of 981
amino acids. The deletion variant was expressed in colon, kidney, heart, liver,
aorta and brain tissues. The relative abundance of the deletion variant compared
to the wild type MR was estimated to be 6% in rat kidney and 4% in hippocampus.
This deletion was also detected in human kidney by RT-PCR. Site-directed
mutagenesis was used to create the eukaryotic expression plasmid pCR3-rMRdel10
from the wild type for a transactivation assay using the luciferase reporter
system in CV-1 cells. The deletion variant had the same baseline transactivation
activity as the wild type MR, but did not respond to aldosterone or
corticosterone stimulation. Co-transfection of MR with the deletion variant had
no significant effect on transactivation activity of the MR, indicating that the
deletion variant is unlikely to serve as a negative regulator of MR function.
PMID- 10687859
TI - Effect of PRL on MAPK activation: negative regulatory role of the C-terminal part
of the PRL receptor.
AB - Prolactin induces cell proliferation and cell differentiation through well-known
MAPK Erk, and JAK2/STAT5 pathways depending on the cell line. The aim of the
present study was to delineate the functional domains of the PRL receptor
involved in PRL induced MAPK regulation. Using various PRL-R mutants of the
cytoplasmic domain we found, that the membrane proximal domain is necessary for
PRL induced MAPK activation and that the C-terminal part of the receptor exerts a
negative regulatory role. A pharmacological approach, using different types of
inhibitors, provided evidence that PRL induced MAPK activation requires both a
MEK dependent pathway and a PI3K dependent pathway. The negative regulation
induced by the carboxy-terminal part of the receptor involves a combination of
tyrosine phosphatases and serine/threonine phosphatases as concluded from the
actions of the phosphatase inhibitors: pervanadate, PAO and okadaic acid. The
mechanism by which these phosphatases are recruited or are induced by the last
141 cytoplasmic residues of the receptor remains to be determined. Finally the
negative regulatory role of the carboxy-terminal part of the receptor, first
demonstrated in the present study, is discussed in terms of the regulation of
different effects of PRL on growth and differentiation.
PMID- 10687860
TI - Relaxin-like factor (RLF) mRNA expression in the fallow deer.
AB - Employing RT- and RACE-PCR on RNA isolated from testicular tissue, we have cloned
the coding cDNA sequence for the RLF, also known as Insl3, of the fallow deer.
The RLF coding sequence consisted of 396 bp encoding a peptide of 131 amino acids
and shared highest homology with bovine, sheep and goat RLF. Northern analysis
revealed a single 0.9 kb transcript in the deer testis. There is only one RLF
gene in the deer genome. Nonradioactive in situ hybridization revealed the Leydig
cells to be the sole source for RLF mRNA in the deer testis. In the non-pregnant
uterus, RLF transcripts were located in the luminal and glandular epithelium of
the endometrium. Within the ovary of the pregnant doe, follicular theca interna
cells and the corpus luteum expressed RLF transcripts. In uteroplacental tissues,
luminal and glandular epithelium, fetal uninucleate and binucleate trophoblast
cells (BNC) of the basic villous trophoblast layer expressed RLF mRNA. BNC
located at the apical trophoblast layer or the tip of the fetal villus were
devoid of RLF transcripts. Pseudostratified trophoblast cells at the base of
fetal villi coexpressed RLF mRNA and immunoreactive MHC class Ib molecules.
PMID- 10687861
TI - Expression and regulatory function of the transcription factor Sp1 in the uterine
endometrium at early pregnancy: implications for epithelial phenotype.
AB - The uterus during early pregnancy synthesizes a complex array of signaling
molecules with specific spatial and temporal modes of expression and which are
critical for embryo implantation and subsequent development. The mechanism(s)
underlying the differential pattern of synthesis of these pregnancy-associated
proteins is not understood very well. The present study evaluated the expression
and trans-activation potential of the transcription factor Sp1 in the early
pregnancy porcine endometrium to determine its temporal and functional
association with the endometrial epithelial-specific genes encoding the
transplacental iron-transport protein uteroferrin (UF) and an Sp-family member,
basic transcription element-binding (BTEB) protein. Two identical Sp1 clones (717
bp) were isolated from a porcine endometrial cDNA library by polymerase chain
reaction (PCR). The nucleotide sequence of these clones encodes a partial protein
sequence of 238 amino acids encompassing the Zn-finger region and had significant
identities with the corresponding regions in the rat and human proteins. By using
a specific antibody raised against human Sp1, porcine endometrial Sp1 was found
to exhibit a molecular weight of 110 kDa, was localized predominantly in the
nuclei of glandular and luminal epithelial cells, and appeared to exist as a
phosphorylated protein. Northern blot analysis demonstrated three distinct size
transcripts of approximately 3.5, 5, and 8 kb for endometrial Sp1. The expression
of Sp1 mRNA and protein, determined by RT-PCR and by its ability to bind Sp1
consensus motif in gel mobility shift assays, respectively, overlapped with, but
did not parallel that of UF mRNA during early pregnancy. The effect of increased
Sp1 expression on UF gene promoter activity was examined using a human Sp1
expression vector that was transiently transfected into primary cultures of pig
endometrial glandular epithelial cells. Sp1 increased (P < 0.05) the promoter
activities of various UF promoter-Luciferase reporter constructs by 2 to 4-fold,
over those transfected with empty expression vector. Co-transfection of a BTEB
expression vector with the Sp1 expression vector modified the effect of Sp1 on UF
promoter activity in the shortest construct. These results suggest that Sp1
mediates the regulation of endometrial epithelial gene expression during
pregnancy, and that this function is likely altered in vivo by co-expression of
other family members, including BTEB.
PMID- 10687862
TI - Partial characterization of the CCAAT box in the promoter of the hLGFBP-1 gene:
interaction with negatively acting transcription factors in decidualized human
endometrial stromal cells.
AB - The CCAAT cis-element and its adjacent DNA sequence (-82 to -52 bp) in the human
insulin-like growth factor binding protein-1 gene (IGFBP-1) promoter are active
in both decidualized human endometrial stromal cells and HepG2 cells. In HepG2
cells, CCAAT activity is mediated by interacting with hepatocyte nuclear factor,
HNF-1. In endometrial cells, this region is protected by the nuclear extracts of
endometrial decidual cells, however, the transactivator which interacts with the
region has not been identified. This study was carried out to characterize and
identify the stromal/decidual nuclear proteins that interact with the IGFBP-1
CCAAT motif. Gel shift analysis showed that the CCAAT motif (-82 to -52 bp)
formed three specific complexes (CI, CII, and CIII) by extracts from human
endometrial decidual or stromal cells. The intensity of CIII formed by the
nuclear extracts of decidual cells was less compared to that formed by stromal
cells whereas CI/CII was found to be opposite. To evaluate the transcription
factors that bind to this region, a number of known CCAAT binding proteins were
tested. Among them, the CCAAT binding proteins NF-Y (alpha2(1) collagen promoter
CCAAT binding protein) and CBF (hsp70 promoter CCAAT binding protein), were
characterized by the gel shift assay. The NF-Y consensus binding sequence (the
alpha2(1) collagen promoter) and NF-YA,B antibody abolished or shifted CIII.
Although the CBF consensus binding sequence (the hsp70 promoter) eliminated all
three complexes, the antibody to CBF had no effect on all three complexes. The
nuclear extracts of the endometrial stromal/decidual cells did not form a band
corresponding to the HNF-1/CCAAT complex. These results indicate that the CCAAT
motif binds to NF-Y and the CI/CII binding protein (remains to be identified) but
not HNF-1 in endometrium. Systematic mutation in the CCAAT motif showed that NF
Y(CIII binding protein) bound to the 12 bp sequence GGCGCTGCCAAT(-79 to -68 bp)
and the CI/CII binding protein bound to 9 bp, TGCCAATCA(-74 to -66 bp). These
findings indicate that the CCAAT motif is a composite element. The CCAAT mediated
function was analyzed in decidualized endometrial stromal cells. Mutations in the
CCAAT motif increased the promoter activity. The maximum activity was found in
mutants which abolished the NF-Y complex. The CCAAT core sequence mutants in
which both CIII and CI/CII were abolished, also increased the promoter activity.
Results indicated that NF-Y and the CI/CII binding protein, yet to be identified,
interact with the composite CCAAT element in the IGFBP-1 promoter to repress the
promoter activity in endometrial decidual cells.
PMID- 10687863
TI - Permissive effect of thyroid hormones on induction of rat colonic Na+ transport
by aldosterone is not localised at the level of Na+ channel transcription.
AB - The interrelationship between thyroid hormones and aldosterone has been examined
in the regulation of rat colonic amiloride-sensitive Na+ transport which
translocates Na+ through apical amiloride-sensitive Na+ channels and basolateral
Na+, K+-ATPase. Electrogenic Na+ transport was measured in an Ussing chamber by
the short-circuit current and identified by Na+ channel blocker amiloride. Na+
pumping activity of the basolateral Na+,K+-ATPase was investigated in nystatin
treated epithelium by measuring the equivalent short-circuit current after
addition of mucosal Na+. The abundance of mRNA coding for alpha, beta and gamma
subunits of the Na+ channel (rENaC) was estimated using Northern blot analysis.
Hyperaldosteronism was induced by a low-salt diet and hypothyroidism by
methimazole. The low-Na+ diet induced electrogenic Na+ transport in euthyroid
rats but its effect was almost completely inhibited in hypothyroid animals even
if the plasma concentration of aldosterone was high enough to stimulate this
transport pathway both in euthyroid and hypothyroid rats. A kinetic study of the
basolateral Na+,K+-ATPase revealed a decrease of Na+ transport capacity in
hypothyroid rats kept on the low-Na+ diet in comparison with euthyroid animals
fed the same diet. No significant differences in steady-state levels of alpha,
beta and gamma rENaC mRNA were detected between euthyroid and hypothyroid rats.
These data suggest that hypothyroidism decreases the efficacy of the basolateral
Na+ pump but fails to inhibit it completely even though it inhibits the
transepithelial electrogenic Na+ transport in response to aldosterone. We
conclude that the permissive effect of thyroid hormones on the induction of
electrogenic Na+ transport by aldosterone is localised beyond the transcriptional
step of Na+ channel regulation.
PMID- 10687864
TI - Temporal expression and T3 induction of thyroid hormone receptors alpha1 and
beta1 during early embryonic and larval development in zebrafish, Danio rerio.
AB - The effects of thyroid hormones on metabolism and development are mediated by
thyroid hormone receptors (TRs). We report the cloning and characterization of a
TR beta1 cDNA from zebrafish. Southern blot analysis revealed that there is a
single genomic locus for the TR beta gene, while the TR alpha gene potentially
has two loci. Multiple TR alpha and TR beta transcripts were detected in adult
tissues. Using a semiquantitative RT-PCR assay, zygotic expression of TR alpha1
and TR beta1 were shown to occur before the midblastula transition stage. In
transiently transfected HeLa cells, TR alpha1 displayed constitutive
transactivation in the absence of ligands, which was slightly enhanced by
triiodothyronine (T3). The transactivating activity of TR beta1 was strictly
ligand-dependent and repressed in the absence of T3. Finally, the T3 induction of
TR alpha1 and TR beta1 mRNAs was demonstrated in zebrafish embryos and larvae.
The auto-induction of TR alpha1 and TR beta1 may serve a regulatory role during
the embryonic and larval development of zebrafish.
PMID- 10687865
TI - Perinatal toxicology of Ruta chalepensis (Rutaceae) in mice.
AB - Dried leaf infusions of Ruta chalepensis L. (Rutaceae), 'rue', 'ruda', were found
to cause perinatal changes in mice, at daily doses of 0.16, 0.80 and 1.60 g/kg,
administered p.o. from 1 to 14 days post coitum. Significant decreases in the
appearance time of physical signs, righting reflex and cliff avoidance together
with minus scores in string test and swimming ability were observed. Moreover,
histological studies showed progressive angiogenic development on placenta blood
supply and weakness at blood barrier in brain, thymus and pery-lymph vestibule.
We found out that the results tend to confirm the embryotoxic effect of the plant
and its harmful use.
PMID- 10687866
TI - Effect of Tephrosia vogelii and Justicia extensa on Tilapia nilotica in vivo.
AB - According to our and other ethnobotanic studies (Walker, R., 1951. Une Nouvelle
Legumineuse du Gabon servant a narcotiser le poisson. Rev. Bot. Appl. 31, 327;
Walker, R., Sillans, R., 1961. Les plantes utiles du Gabon. Encyclopedie
Biologique. P. Chevalier, Paris; Halle, N., 1970. Flore du Gabon 17, Famille des
Rubiacees. Museum National d'Histoire Naturelle, Paris; Mounzeo, H., et al.,
1997. Quelques plantes utilisees comme poisons de peches chez les Punu du Gabon.
Le Flamboyant 44. Decembre, Bulletin de Liaison des membres du reseau 'Arbres
Tropicaux'), Tephrosia vogelii and Justicia extensa are two plants whose leaves
are particularly used for the catching of fish in Gabonese rivers. The leaf
extracts of those plants have been tested on Tilapia nilotica in order to observe
their toxicity. At a given dose, the small fish are the first to be poisoned.
This toxicity is more important for J. extensa and increased in a dose-dependent
manner. After boiling for 90 min, those leaf extracts and rotenone (10(-6) M)
taken as a control retain their toxicity at high dose (625 mg/l), although the
latency period is higher. With the same temperature condition, at weak doses
(37.5 and 62.5 mg/l), T. vogelii loses its toxicity, whereas J. extensa preserves
it at 62.5 mg/l. As shown in our results, the fact that the extracts preserve
their toxicity at high dose after boiling requires particular attention be given
to the doses used for fishing and to the type of plants used.
PMID- 10687867
TI - CNS acetylcholine receptor activity in European medicinal plants traditionally
used to improve failing memory.
AB - Certain Lamiaceous and Asteraceous plants have long histories of use as
restoratives of lost or declining cognitive functions in western European systems
of traditional medicine. Investigations were carried out to evaluate human CNS
cholinergic receptor binding activity in extracts of those European medicinal
plants reputed to enhance or restore mental functions including memory. Ethanolic
extracts were prepared from accessions of these plants and a number of other
species related by genus. Amongst the plant extracts screened for contents able
to displace [3H]-(N)-nicotine and [3H]-(N)-scopolamine from nicotinic receptors
and muscarinic receptors, respectively in homogenates of human cerebral cortical
cell membranes, the most potent extracts, prepared from one accession of Melissa
officinalis, three Salvia species and Artemisia absinthium had IC50
concentrations of < 1 mg/ml. The displacement curves of some extracts were
comparable with that of carbamylcholine chloride, a potent acetylcholine
analogue. Choline, a weak nicotinic ligand (IC50 = 3 x 10(-4) M) was found in
extracts of all plants studied at concentrations of 10(-6)-10(-5) M. These
concentrations could not account for not more than 5% of the displacement
activity observed. Some extracts displayed differential displacement at nicotinic
and muscarinic acetylcholine receptors, with M. officinalis 0033 having the
highest [3H]-(N)-nicotine displacement value and Salvia elegans with the highest
[3H]-(N)-scopolamine displacement value. There was also considerable variation in
cholinoreceptor interactions between different accessions of a single plant
species. Although most plant extracts screened showed some nicotinic and
muscarinic activity, only some showed dose-dependent receptor activity typical of
materials with genuine cholinergic activity.
PMID- 10687868
TI - Enhanced DNA repair, immune function and reduced toxicity of C-MED-100, a novel
aqueous extract from Uncaria tomentosa.
AB - Female W/Fu rats were gavaged daily with a water-soluble extract (C-MED-100) of
Uncaria tomentosa supplied commercially by CampaMed at the doses of 0, 5, 10, 20,
40 and 80 mg/kg for 8 consecutive weeks. Phytohemagglutinin (PHA) stimulated
lymphocyte proliferation was significantly increased in splenocytes of rats
treated at the doses of 40 and 80 mg/kg. White blood cells (WBC) from the C-MED
100 treatment groups of 40 and 80 mg/kg for 8 weeks or 160 mg/kg for 4 weeks were
significantly elevated compared with controls (P < 0.05). In a human volunteer
study, C-MED-100 was given daily at 5 mg/kg for 6 consecutive weeks to four
healthy adult males. No toxicity was observed and again, WBC were significantly
elevated (P < 0.05) after supplement. Repair of DNA single strand breaks (SSB)
and double strand breaks (DSB) 3 h after 12 Gy whole body irradiation of rats
were also significantly improved in C-MED-100 treated animals (P < 0.05). The
LD50 and MTD of a single oral dose of C-MED-100 in the rat were observed to be
greater than 8 g/kg. Although the rats were treated daily with U. tomentosa
extracts at the doses of 10-80 mg/kg for 8 weeks or 160 mg/kg for 4 weeks, no
acute or chronic toxicity signs were observed symptomatically. In addition, no
body weight, food consumption, organ weight and kidney, liver, spleen, and heart
pathological changes were found to be associated with C-MED-100 treatment.
PMID- 10687869
TI - A search for natural bioactive compounds in Bolivia through a multidisciplinary
approach. Part I. Evaluation of the antimalarial activity of plants used by the
Chacobo Indians.
AB - Thirty extracts of plants traditionally used by the Chacobos, a native community
living in the Amazonian part of Bolivia, were screened in vitro and/or in vivo
for antimalarial activity. Two of the four species designated as antimalarial,
Geissospermum laeve and Maquira coriacea, displayed rather good activity,
corroborating their traditional uses. However, they did show a rather high
toxicity in vivo. Among twelve species used to cure symptoms relevant to malaria,
five showed good activity: Apuleia leiocarpa, Bauhinia guianensis, Nectandra
cuspidata, Sparattanthelium amazonum, Tanaecium jaroba. Two species, Qualea
paraensis and Sclerolobium aff. guianense, used to treat scabies, showed
interesting antimalarial activity in vivo; three other species (Iryanthera
laevis, Prunus amplifolia, Pterocarpus aff. amazonum) used for various medicinal
purposes, apparently not related with a Plasmodium infection, also showed
antimalarial activity. Finally, one species (Derris amazonica) used as a
piscicide displayed good in vitro activity, in the same way as one Annonaceae,
Guatteria aff. schomburgkiana, used for construction purposes.
PMID- 10687870
TI - The search for natural bioactive compounds through a multidisciplinary approach
in Bolivia. Part II. Antimalarial activity of some plants used by Mosetene
indians.
AB - Forty-six different species collected in the Mosetene ethnia, dwelling in the
Andean Piedmont of Bolivia, were screened for antimalarial properties. Thirty
three extracts were screened for antimalarial activity in vitro on Plasmodium
falciparum chloroquine resistant strain (Indo), and forty-seven extracts were
evaluated in vivo on the rodent malaria P. vinckei petteri 279BY. Only two plants
are specifically used in combination by the Mosetene against malaria attack
(Hymenachne donacifolia and Tesseria integrifolia), but they did not display any
activity in vivo at 1000 mg/kg. The in vivo most active extracts were Swietenia
macrophylla bark, Trema micrantha bark and Triplaris americana bark, not all of
them were used for antimalarial purposes by the Mosetene. The following extracts
were moderately active: Jacaratia digitata inner bark and Momordica charantia
aerial part (both traditionally used as febrifuge), Kalanchoe pinnate aerial part
(used in inflammatory processes), Lunania parviflora twigs and leaves,
Phyllanthus acuminatus (used as piscicide), Tynanthus schumannianus fruit (used
against diarrhoea), Triumfetta semitrilobata (used as febrifuge, to alleviate
kidney and gynecological pain) and finally Solanum mammosum fruit (used against
scabies). We present here the results of this screening, emphazing on the in vivo
antimalarial activity of the selected plants. The antimalarial in vivo activity
of the selected species, in relation with their traditional Mosetene use is then
discussed.
PMID- 10687871
TI - Evaluation of the efficacy of Lawsonia alba in the alleviation of carbon
tetrachloride-induced oxidative stress.
AB - The hepatoprotective activity of the 50% ethanol extract of the bark of Lawsonia
alba syn. L. inermis was investigated against the carbon tetrachloride-induced
oxidative stress. Pretreatment of rats with doses of 250 and 500 mg/kg of the
plant extract significantly (P < 0.001) lowered serum transaminases (GOT and GPT)
and LDH levels, respectively, in a dose dependent manner against the significant
(P < 0.001) rise of these damage marker enzymes when challenged with CCl4 (1
ml/kg, orally). Parallel to these changes, the plant extract prevented CCl4
induced oxidative stress by significantly maintaining the levels of reduced
glutathione (GSH), its metabolizing enzymes and simultaneously inhibiting the
production of free radicals. Pretreatment of rats with the extract also inhibited
the peroxidation of microsomal lipids in a dose-dependent manner.
PMID- 10687872
TI - Ethnobotanical inventory of medicinal plants in Bulgaria.
AB - The paper reports on 73 medicinal plants of 30 families, traditionally used in
Bulgarian phytotherapy. Some of the plants are applied in practice for the
treatment of cardiovascular, gastrointestinal, respiratory, urogenital and other
disorders. The popular plants used for treatment are growing in 20 forested
regions in Bulgaria.
PMID- 10687873
TI - Anti-inflammatory effects of fangchinoline and tetrandrine.
AB - Fangchinoline and tetrandrine are the major alkaloids from Stephania tetrandrae
S. Moore which has been used traditionally for the treatment of inflammatory
diseases in oriental countries including Korea. Both fangchinoline and
tetrandrine showed anti-inflammatory effects on mouse ear edema induced by croton
oil. In addition, the effects of fangchinoline and tetrandrine on cyclooxygenase,
murine interleukin-5 (mIL-5) and human interleukin-6 (hIL-6) were examined in
vitro to investigate the anti-inflammatory action mechanisms. One hundred
micromolar of fangchinoline showed 35% of inhibition on cyclooxygenase, but the
same concentration of tetrandrine did not show any inhibition. On the other hand,
12.5 microM of tetrandrine exhibited 95% of inhibition on mIL-5 activity, while
fangchinoline did not show any effects. However, 4 microM of fangchinoline and 6
microM of tetrandrine showed 63 and 86% of inhibitions on hIL-6 activity,
respectively. These results suggest that biochemical mechanisms of fangchinoline
and tetrandrine on anti-inflammation are significantly different even though they
are similar in chemical structure.
PMID- 10687874
TI - Fetotoxicity and reproductive effects of monocrotaline in pregnant rats.
AB - Four groups of 12 pregnant Wistar rats each were fed with rations containing 0,
0.01, 0.015 and 0.02% of monocrotaline (MCT) from day 6 to 21 of gestation. Liver
weights of the dams from the three experimental groups were significantly lower
than those from the control group. Serum levels of aspartate aminotransferase;
alkaline phosphatase; lactate dehydrogenase; gamma glutamyltransferase, urea and
creatinine were significantly higher in dams from MCT 0.02% group. The weights of
the placenta, fetuses and fetal lungs of the 0.02% MCT group were significantly
lower than those of the control group. A mild to moderate interstitial pneumonia
and liver lesions were observed in dams ingesting 0.02% of MCT. These results
showed the toxicity of MCT to the females that ingested 0.02% and their fetuses.
Because there was no differences on the weight gains and food and water
consumption of the dams it is suggested that this toxic effects in the fetuses
was caused by the diffusion of MCT through the placenta. No significant
differences were observed in the frequency of skeletal and visceral malformation
or anomalies between the control and treated groups suggesting that MCT had no
teratogenic effect.
PMID- 10687875
TI - Effect of crude extracts of Erythrina americana Mill. on aggressive behavior in
rats.
AB - Three alkaloid fractions were obtained from seeds of Erythrina americana: free
alkaloids in hexane, free alkaloids in methanol and liberated alkaloids. The
pharmacological evaluation of these fractions on rats showed that, administered
in a dose of 3 mg/kg, the three fractions diminished the aggressive behavior.
This is comparable when diazepam is used as a control. An interaction between the
cholinergic and GABAergic system could be suggested.
PMID- 10687876
TI - It's time to stop using the word 'replacement'.
PMID- 10687877
TI - Andropause.
AB - Although, in distinction to middle aged women, in middle aged men there does not
occur a sudden arrest of gonadal functions, fertility persisting until very old
age, aging in men is, nevertheless, associated with an gradual decline of both
endo- and exocrine testicular function. Whereas age has in fact only minimal
effects on the quality of the ejaculate, endocrine function declines steadily
with age and at age 75 years, mean plasma testosterone levels are only 65% of
levels in young adults whereas over 25%, of these men have bioavailable
testosterone levels below the lower normal limit in young adults. The
interindividual variations in the plasma levels are, however, very important and
a quarter of men over 75 years old, have still testosterone levels within the
upper quartile of values in young men. Aging is accompanied by a series of signs
and symptoms, many of which are rather similar to those observed in young
hypogonadal males. The etiology of these signs and symptoms is often
multifactorial, and very few correlations have been found between symptoms and
plasma testosterone levels. Nevertheless, there is good evidence that the age
associated decrease in testosterone levels is at least a co-determinant of these
symptoms and testosterone supplementation has shown favorable effects on many of
them. Side effects of this substitutive therapy are minimal when care is taken to
keep plasma testosterone levels within the physiological range. Clinical
prostatic carcinoma is an absolute contra-indication for testosterone
supplementation. So far, there are no indications that testosterone would
stimulate the evolution of as subclinical prostatic carcinoma to a clinical
carcinoma but it should be recalled that so far, only a small number of elderly
males received substitutive androgen treatment for longer periods in controlled
studies. Hence, although side effects are generally minimal, one should,
nevertheless, await the results of larger, long term, well-controlled studies
before to recommend the routine testosterone substitution of elderly men.
PMID- 10687878
TI - Quality of life after the menopause: a population study.
AB - OBJECTIVE: To assess the impact of menopause and some sociodemographic variables
on quality of life (QoL). MATERIALS AND METHODS: Four hundred and eighty-one
women aged 40-59 years attending the Southern Metropolitan Health Service in
Santiago de Chile were studied using the Specific Quality of Life Questionnaire
for Menopause from Toronto University. RESULTS: Univariate analysis showed that
menopausal women have worse QoL scores than women conserving cycles in the four
areas of the questionnaire: They show a 10.6-fold higher risk for suffering
vasomotor disorders affecting QoL, a 3.5-fold higher risk for psychosocial
impairment, a 5.7-fold higher risk for physical disorders, and a 3.2-fold higher
risk for sexual disorders (P < 0.0001). Regarding the influence of social markers
(age, marital status, school years, work, number of children and sexual
activity), housewives were found to have higher, worse, scores than working women
in all test components (vasomotor, 3.11+/-1.90 versus 2.57+/-1.71, P < 0.003;
psychosocial, 3.44+/-1.59 versus 2.92+/-1.45, P < 0.0007; physical, 3.45+/-1.36
versus 2.96+/-1.20, P < 0.0001; sexual, 3.63+/-2.23 versus 2.49+/-1.95, P <
0.0001). However, logistic regression demonstrated that the only variable found
to cause a significant impairment in QoL was menopause. CONCLUSION: Menopause
causes a decrease in quality of life, which is independent from age and other
sociodemographic variables.
PMID- 10687879
TI - Determinants of elevated blood pressure in women around menopause: results from a
cross-sectional study in Italy.
AB - OBJECTIVE: To analyse the determinants of high blood pressure in women around
menopause. METHODS: Eligible women were consecutively identified among patients
who asked for a visit of their general practitioner during the period March
November 1997. A total of 22919 women aged 44-66 years (median age 55 years),
were identified. Women whose mean of the second and third of the three measures
of diastolic blood pressure values performed during interview was > 90 mm of
mercury and/or reporting any type of current pharmacological treatment for
elevated blood pressure were considered hypertensive. RESULTS: In comparison with
women aged 40-50 years, the multivariate odds ratio (OR) of elevated blood
pressure were 1.4 in women aged 51-55, 2.0 in those aged 56-60 and 2.7 in those
aged > or = 61. In comparison with women with a body mass index (kg m(-2)) < 25,
the OR of elevated blood pressure was 1.7 and 2.7, respectively, for women with a
BMI of 25 28 and > or = 29. In comparison with women reporting a low level of
physical activity, the OR of elevated blood pressure were 0.9 (95%, confidence
interval, CI 0.7-1.0) and 0.7 (95% CI 0.4-0.9), respectively, for those reporting
an intermediate or high level of activity. In comparison with premenopausal
women, the OR of elevated blood pressure was, after taking into account the
confounding effect of age, 1.6 (95% CI 1.0-1.4) in post menopausal ones. The OR
of elevated blood pressure was 0.8 (95% CI 0.7-0.9), for current users of hormone
replacement therapy (HRT), but no clear association emerged with duration of HRT
pressure. CONCLUSIONS: This study suggests that, after taking into account the
effect of age, post-menopausal women are at higher risk of the condition, and
current HRT use decreases the risk. Other main determinants of risk of elevated
blood pressure were overweight and low physical activity.
PMID- 10687880
TI - Does apolipoprotein E genotype relate to BMD and bone markers in postmenopausal
women?
AB - OBJECTIVES: Bone mineral density (BMD) and development of osteoporosis are partly
determined by genetic factors. The associations between one of suggested
candidate, apolipoprotein E (apo E) genotype to bone mineral density (BMD) and
bone biochemical markers was studied in 464 subjects recruited from a population
based group of early postmenopausal women (n = 13100). Additionally, the
influence of apo E genotype on BMD changes during a 5-year follow-up with or
without hormone replacement therapy (HRT) was investigated. METHODS: Participants
were randomized into two treatment groups: HRT group: Sequential combination of 2
mg estradiol valerate and 1 mg cyproterone acetate with or without vitamin D3,
100-300 IU/day + calcium lactate, 500 mg/day (n = 232), and the non-HRT group:
Calcium lactate, 500 mg/day alone or in combination with vitamin D3, 100-300
IU/day (n = 232). BMD was measured from the lumbar spine and proximal femur at
baseline and after 5 years of treatment (n = 352). In a subgroup (n = 59), the
serum concentrations of bone biochemical markers (intact osteocalcin (OC), bone
specific alkaline phosphatase (BAP) and type I collagen carboxy-terminal
telopeptide (ICTP)) were measured at baseline and after 1 year of follow-up.
RESULTS: At baseline, the BMDs were similar between the five apo E genotype
groups (2/3, 2/4, 3/3, 3/4, 4/4). No significant differences in lumbar or femoral
neck BMDs of women with the apo E4 allele were found compared with those without
it. There was a statistically significant difference in 5-year BMD changes
between the HRT and non-HRT groups. After 5 years, the BMD of the femoral neck
had remained constant and the mean lumbar spine BMD had increased by 1.5% in the
HRT group, whereas both BMDs had decreased by 4-5% in the non-HRT group. However,
the apo E genotype did not modify the changes in BMD in either group.
Additionally, the baseline concentrations of bone metabolic markers and their 1
year changes showed no genotype-related associations. CONCLUSIONS: The results of
our population-based study indicate that apo E genotype does not modify lumbar or
femoral neck BMDs or serum bone biochemical markers or their response to HRT in
early postmenopausal Caucasian women.
PMID- 10687881
TI - Hypersecretion of ovarian androgens may be gonadotrophin dependent many years
after menopause.
AB - BACKGROUND: In fertile women both adrenals and ovaries contribute to androgen
production, whereas after the menopause the ovarian contribution normally
decreases. OBJECTIVE: The objective of this case study was to assess whether
ovarian androgen secretion was responsive to decreased gonadotrophin stimulation
and whether gonadotrophins were sensitive to negative feedback from sex steroids
many years after the menopause. METHODS: In this uncontrolled case study a 72
years old slightly overweight woman with noninsulin-dependent diabetes mellitus
presented with hirsuitism and elevated serum testosterone concentrations. The
woman was reluctant to have an oophorectomy, and received an oral
estradiol/progestagene preparation. Serum testosterone and gonadotrophin
concentrations were measured before and after steroid hormone therapy. RESULTS:
Serum gonadotrophin concentrations decreased and testosterone levels returned to
normal during therapy. When the hormone therapy was stopped for 1 month the high
testosterone concentrations returned, but were again normalized when the hormone
therapy was reinitiated. CONCLUSION: The ovaries of this woman were apparently
still responsive to pituitary stimulation and her hypothalamic pituitary ovarian
feed-back system still seemed to be working after 70 years of age.
PMID- 10687882
TI - Efficacy and tolerability of a new estradiol delivering matrix patch (Estraderm
MX) in postmenopausal women.
AB - OBJECTIVE: To examine the efficacy and tolerability of a new matrix patch
delivering estradiol (E2 Matrix) at doses of 0.05 and 0.10 mg per day (Estraderm
MX 50, 100) in the treatment of moderate to severe postmenopausal symptoms.
METHODS: A total of 254 postmenopausal women were randomized to receive treatment
with E2 Matrix 0.10 mg (N = 86), E2 Matrix 0.05 mg (N = 82), or placebo (N = 86)
in a double-blind, double-dummy fashion for a period of 12 weeks continuously.
Patches were applied twice weekly to the buttocks with each patient wearing two
patches at all times. The primary efficacy criterion was the difference from
baseline of the mean number of moderate to severe hot flushes per 24 h during the
last 2 weeks of treatment. Other efficacy variables included reduction in hot
flushes at 4 and 8 weeks, reduction in daytime flushing and night sweats, and
Kupperman Index at 4, 8, and 12 weeks. RESULTS: E2 Matrix 0.10 and 0.05 mg were
both significantly superior to placebo in reducing hot flushes per 24 h after 4,
8, and 12 weeks of treatment (P < 0.001). Also, for all other efficacy parameters
studied, both dosage strengths of E2 Matrix were statistically significantly
superior to placebo at all time points (P < 0.001). Local tolerability was good
in both groups. A slight increase in estrogen related adverse effects (breast
tenderness, leukorrhoea) was seen with the 0.10 mg patch. Adhesion of patches and
compliance were good. Overall systemic tolerability was good in both treated
groups. However, a 4.8% overall incidence of endometrial hyperplasia was observed
in patients with an intact uterus. CONCLUSIONS: This new matrix patch offers an
effective and well tolerated dosage form for delivery of 0.05 and 0.1 mg
estradiol per day. It may be particularly suitable for those women who experience
local sensitivity to alcohol-containing systems. In light of the observed
hyperplasia after treatment in five patients, estrogen therapy should as yet be
supplemented monthly with a progestogen in women with an intact uterus.
PMID- 10687883
TI - Bioavailability of estradiol from two matrix transdermal delivery systems:
Menorest and Climara.
AB - OBJECTIVES: To compare two estradiol transdermal matrix systems with regard to
bioavailability, pharmacokinetics and tolerability. METHODS: A single centre,
open, randomized, comparative cross-over study in 20 healthy postmenopausal
women. Menorest with 3 or 4 days of suggested use and Climara with 7 days of
suggested use (both 50 microg/24 h) were compared at steady state. Two 14-day
treatment periods were separated by a 4 week washout. Plasma levels of estradiol
were monitored during the second week of each treatment. Tolerability was
assessed by open questions and inspection of the application site. RESULTS: There
were no differences between the two treatments with regards to AUC, Cmax, Cmin,
Caverage or fluctuations of plasma estradiol. Tmax was significantly shorter for
Menorest than Climara. Cmax and Cmin were significantly higher for the second
Menorest patch during the monitoring period compared to the first. All local
reactions were mild and there were three cases of erythema with Menorest and a
total of 21 skin reactions in 15 subjects with Climara. Systemic tolerability was
similar between treatments with eight estrogen-related adverse events in eight
subjects (period pains, uterine bleeding, mastodynia, headache and vaginal
discharge) with Menorest and 13 events in ten subjects with Climara. CONCLUSIONS:
The bioavailability of estradiol from the two matrix transdermal delivery systems
Menorest and Climara was similar, but the products were not bioequivalent because
Tmax was significantly shorter for Menorest than for Climara. Tolerability of
treatment was good for both patches but with a higher number of local reactions
and estrogen related adverse events for Climara.
PMID- 10687884
TI - Characterization of hot flashes reported by healthy postmenopausal women
receiving raloxifene or placebo during osteoporosis prevention trials.
AB - OBJECTIVE: Raloxifene, a selective estrogen receptor modulator, is estrogen-like
in the skeleton and cardiovascular system and antiestrogenic in reproductive
tissues. In contrast to estrogens, raloxifene is not indicated for the treatment
of hot flashes. This study was designed to examine the characteristics of hot
flashes among healthy postmenopausal women participating in osteoporosis
prevention trials who were receiving raloxifene or placebo. METHODS: Adverse
event data from three randomized, double-blind trials (N = 876) comparing
raloxifene 60 mg/day with placebo for 30 months were integrated and analyzed. Two
of the three trials (one European, two North American) were identically designed
and were open to healthy postmenopausal women ages 45 through 60 without regard
to prior hysterectomy. The third trial was multinational, was open to women ages
40 through 60, and all enrollees had prior hysterectomy at baseline. Women were
questioned in general terms about the occurrence of adverse events at 3-6-month
intervals. Treatment-emergent adverse events pertaining to hot flashes were
included in the current study. RESULTS: At baseline, 12% of women randomly
assigned to placebo and 13% assigned to raloxifene reported prevalent hot
flashes. After 30 months, the cumulative incidence of hot flashes was 21% for
placebo and 28% for raloxifene (P = 0.022), with the difference in incidence rate
confined to the first 6 months of therapy. There was no difference between
placebo and raloxifene in reported maximum severity of or early discontinuations
as a result of hot flashes (< or = 3% per group for both outcomes). Among women
whose hot flashes had stopped completely during the 30-month study period, the
median total duration of the event prior to becoming symptom-free was 246 days
for placebo and 205 days for raloxifene. Among all women reporting a hot flash,
the extrapolated total duration of hot flashes was the same for women treated
with either raloxifene or placebo. No subgroup-by-therapy interactions were
detected. Multivariable regression analysis revealed several factors that were
independently weakly predictive of hot flashes. CONCLUSIONS: Raloxifene slightly
affects the incidence but not the natural history of hot flashes in healthy
postmenopausal women seeking prevention therapy.
PMID- 10687885
TI - The effect of hormone replacement therapy on metabolism of lipoprotein remnants
in postmenopausal women.
AB - OBJECTIVE: The measurement of remnant-like particles reflects chylomicron and
very low density lipoprotein remnants which are most likely atherogenic
particles. We investigated the effects of menopausal status and postmenopausal
hormone replacement on metabolism of remnant lipoprotein-cholesterol. METHODS: We
measured remnant lipoprotein-cholesterol by an immunoseparation assay in 20
premenopausal, 40 postmenopausal, and 30 bilaterally oophorectomized women. Of 70
postmenopausal subjects, 21 surgically menopausal women (with total hysterectomy)
were started on hormone replacement with conjugated equine estrogen, 0.625
mg/day, and 36 naturally postmenopausal women were begun on a combination of
conjugated equine estrogen 0.625 mg/day, plus medroxyprogesterone acetate, 2.5
mg/day. Plasma levels of remnant lipoprotein-cholesterol and other common lipids
were measured after 6 and 12 months of treatment. RESULTS: Plasma remnant
lipoprotein-cholesterol levels in postmenopausal and surgically menopausal women
were significantly higher than in premenopausal women (P < 0.005). Plasma total
and low-density lipoprotein cholesterol levels decreased and high-density
lipoprotein cholesterol increased significantly (P < 0.01) in both treatment
groups, respectively. Plasma triglyceride levels were not changed by treatment;
however, remnant lipoprotein-cholesterol levels decreased in both treatment
groups (estrogen group; P = 0.07, estrogen-progestin group; P < 0.05). No side
effects of therapy were consistently reported. CONCLUSIONS: We confirmed that
remnant lipoprotein-cholesterol increases after menopause. Hormone replacement
therapy improves disordered lipoprotein metabolism and exerts a favorable effect
on lipoprotein remnant metabolism in postmenopausal women.
PMID- 10687886
TI - Effects of combined sex hormone replacement therapy on small artery biomechanics
in pharmacologically ovariectomized rats.
AB - OBJECTIVES: The purpose of this study was to determine the effects of long-term
combined sexual hormone replacement therapy on the biomechanical properties of
the small artery wall in castrated female rats. METHODS: 30 non-pregnant mature
female Sprague-Dawley rats were pharmacologically ovariectomized with 750
microg/kg triptorelin im. every 4th week. Ten of them received combined hormone
replacement in form of 15 mg/kg medroxyprogesterone acetate (MPA) im. every 2
weeks and 450 microg/kg estradiol propionate im. once a week. Ten castrated
animals received MPA only. Ten control, castrated animals were given the vehicles
of these steroids. Ten other animals were kept parallelly, receiving the vehicles
of all drugs (control animals). After 12 weeks of treatment cylindrical segments
of the saphenous artery were isolated and cannulated at both ends and subjected
to in vitro microarteriographic test. Pressure diameter curves, in the range of 0
200 mmHg, were recorded from segments in normal Krebs-Ringer (nKR) solution, in
contraction with norepinephrine (1.6 x 10(-5) M), and then in relaxation with
papaverine (2.8 x 10(-5) M). Biomechanical parameters were calculated based on
the pressure diameter curves. RESULTS: Combined hormone replacement therapy
significantly increased the passive diameter of small arteries, as compared to
those from ovariectomized animals without hormone replacement. MPA monotherapy
did not alter the vessel diameter, the inner radii at 100 mmHg intraluminal
pressure were, 300+/-9 microm in the control castrated, 340+/-7 microm in the
estradiol + MPA replaced and 306+/-8 microm in the MPA treated groups (P < 0.05
between the control castrated and the combined treatment groups). The vascular
reactivity to norepinephrine or papaverine was not changed significantly either
by combined hormone replacement or by MPA monotherapy when compared with
ovariectomized controls. No significant alterations were found in wall thickness
and distensibility. CONCLUSIONS: These results suggest that chronic
medroxyprogesterone pretreatment does not influence the geometric, elastic and
contractile properties of small arteries in castrated female rats. The
combination of MPA + estradiol increased the morphological lumen: the
morphological vasodilatation induced by estrogen, described earlier, was not
affected by the addition of this progestin to the regimen.
PMID- 10687887
TI - Vegan proteins may reduce risk of cancer, obesity, and cardiovascular disease by
promoting increased glucagon activity.
AB - Amino acids modulate the secretion of both insulin and glucagon; the composition
of dietary protein therefore has the potential to influence the balance of
glucagon and insulin activity. Soy protein, as well as many other vegan proteins,
are higher in non-essential amino acids than most animal-derived food proteins,
and as a result should preferentially favor glucagon production. Acting on
hepatocytes, glucagon promotes (and insulin inhibits) cAMP-dependent mechanisms
that down-regulate lipogenic enzymes and cholesterol synthesis, while up
regulating hepatic LDL receptors and production of the IGF-I antagonist IGFBP-1.
The insulin-sensitizing properties of many vegan diets--high in fiber, low in
saturated fat--should amplify these effects by down-regulating insulin secretion.
Additionally, the relatively low essential amino acid content of some vegan diets
may decrease hepatic IGF-I synthesis. Thus, diets featuring vegan proteins can be
expected to lower elevated serum lipid levels, promote weight loss, and decrease
circulating IGF-I activity. The latter effect should impede cancer induction (as
is seen in animal studies with soy protein), lessen neutrophil-mediated
inflammatory damage, and slow growth and maturation in children. In fact, vegans
tend to have low serum lipids, lean physiques, shorter stature, later puberty,
and decreased risk for certain prominent 'Western' cancers; a vegan diet has
documented clinical efficacy in rheumatoid arthritis. Low-fat vegan diets may be
especially protective in regard to cancers linked to insulin resistance--namely,
breast and colon cancer--as well as prostate cancer; conversely, the high IGF-I
activity associated with heavy ingestion of animal products may be largely
responsible for the epidemic of 'Western' cancers in wealthy societies. Increased
phytochemical intake is also likely to contribute to the reduction of cancer risk
in vegans. Regression of coronary stenoses has been documented during low-fat
vegan diets coupled with exercise training; such regimens also tend to markedly
improve diabetic control and lower elevated blood pressure. Risk of many other
degenerative disorders may be decreased in vegans, although reduced growth factor
activity may be responsible for an increased risk of hemorrhagic stroke. By
altering the glucagon/insulin balance, it is conceivable that supplemental
intakes of key non-essential amino acids could enable omnivores to enjoy some of
the health advantages of a vegan diet. An unnecessarily high intake of essential
amino acids--either in the absolute sense or relative to total dietary protein-
may prove to be as grave a risk factor for 'Western' degenerative diseases as is
excessive fat intake.
PMID- 10687888
TI - Incorporation of liposome-encapsulated amphotericin in artificial/prosthetic
cardiac valves for therapy and prevention of fungal endocarditis.
AB - Fungal endocarditis is a highly fatal condition. Fungal prosthetic valve
endocarditis is an uncommon but serious infection. Patients require surgery and
long-term antifungal therapy. However, recurrence is quite common and eradication
of infection is difficult. Liposomal amphotericin is considered to be better than
the conventional preparation. It is hypothesized that incorporation of liposome
encapsulated amphotericin inside artificial/prosthetic cardiac valves would
result in better tissue concentration of the drug at site of infection and
probable prevention of recurrence. The cost of making the same might be
considerable but would likely be cost-effective in the long run due to lowered
mortality and prevention of recurrence.
PMID- 10687889
TI - Prevention of progression in chronic myeloid leukemia by altering DNA methylation
with a pyridoxine analogue.
AB - Altered DNA methylation is one mechanism by which progression might occur in
tumors. Progression in chronic myeloid leukemia (CML) was initially thought to be
due to mutations. However, altered DNA methylation might be responsible for the
same. An agent whose probable target is DNA methylation has been shown to improve
hematopoiesis in CML. Pyridoxine is involved in methylation reactions. At
present, the link between dietary factors like pyridoxine and cancer is somewhat
tenuous. It is hypothesized that a suitable pyridoxine analogue might, by
blocking DNA methylation, prevent progression in CML.
PMID- 10687890
TI - Anesthesia is a risk factor for drug and alcohol craving and relapse in ex
abusers.
AB - Relapse to cocaine, heroin, and alcohol is a common occurrence in ex-abusers of
these substances. Although there are many potential causes for relapse, we
postulate that one cause in some people may be re-exposure in an anesthesia
setting to a drug similar to the formerly abused drug. We hypothesize, for
example, that opioids given during and after surgery may reinstate craving for,
and initiate subsequent seeking of, heroin in former abusers. There are a
substantial number of animal studies and some human studies documenting a
reinstatement phenomenon in which an experimenter-administered psychoactive drug
can precipitate drug-seeking behavior in 'abstinent' animals and humans. There is
concern amongst health professionals and patients alike on this issue, and we
discuss possible avenues of research, both preclinical and clinical, to explore
the validity of our hypothesis.
PMID- 10687891
TI - Non-linear model of cancer growth and metastasis: a limiting nutrient as a major
determinant of tumor shape and diffusion.
AB - A new approach for modelling the spatio-temporal evolution of tumors is
presented. To test its validity, a very basic model is considered, which, in
spite of its simplicity, is capable of generating a multiplicity of morphologies
and growth and migration rates. From an in-vivo scenario of basic life processes,
cancer cell proliferation is described as a competition for basic nutrients. The
chosen mathematical treatment and simulation techniques permit a direct
implementation of the local nonlinear couplings existing between the various cell
populations and the free and bound nutrient concentration. A discussion of the
results and proposed improvements and applications of the model is also
presented.
PMID- 10687892
TI - Directed evolution of light-activated drugs.
AB - Photodynamic therapy is a new technology that uses light-activated molecules to
target drug action to diseased areas while sparing healthy tissue. Unfortunately,
the present arsenal of photosensitive molecules is limited in both number and
scope. We hypothesize that new photosensitive molecules could be developed using
directed molecules evolution. This paper outlines a possible selection mechanism
to evolve molecules activated by a desired wavelength of light.
PMID- 10687893
TI - The oxidative stress hypothesis of atherosclerosis: cause or product?
AB - The oxidative stress hypothesis postulates that endogenous free radicals of
unknown origin, possibly derived from mural cells, oxidize low density
lipoproteins and that oxidation products are allegedly responsible for initiation
and progression of atherosclerosis. The thesis fails to explain its topography,
site specific severity and the iatrogenic and experimental hemodynamic induction
of atherosclerosis under conditions complying with the logic of Koch's
postulates. Free radicals are generated by biomechanical scission of
macromolecules and polymers, the biophysical mechanism underlying bioengineering
fatigue in atherogenesis with oxidative damage a secondary, contributory factor
to mural pathology. The plentiful supply of antioxidants negates oxidative stress
as the dominant factor in atherogenesis.
PMID- 10687894
TI - Role of brain organization in the pathogenesis of physical disease.
AB - While genetic and environmental factors are known to make substantial
contributions to the pathogenesis of physical disease, the role of the brain in
these processes is largely unknown. It is hypothesized that the manner in which
the brain is functionally organized is an integral factor in physical health
outcomes, both positive and negative. It is further hypothesized that changes in
certain patterns of the functional organization of the brain play a significant
role in the pathogenesis of physical disease, mediating between an individual's
genetic endowment, the environment, and other relevant brain systems to initiate,
modulate and/or maintain these disorders. There are many currently available
treatment modalities which have the capacity to change the pattern of functional
brain organization. Such interventions have the potential to become valuable aids
in both the treatment and prevention of physical disease.
PMID- 10687895
TI - One explanation of Nef gene behavior.
AB - The Nef (negative factor) gene of primate retroviruses may serve an important
evolutionary function. Selection pressures in the natural world, may at times,
demand that retroviral infection not cause disease in a newly entered host
species. Genetic alterations in the Nef gene may function to permit retroviral
speciation by lowering retroviral replication rate. Slow viral replication may
allow small numbers of the newly infected host species to avoid the effects of
retroviral pathology.
PMID- 10687896
TI - A biophysical basis of enhanced interstitial fluid pressure in tumors.
AB - It is widely accepted that enhanced interstitial fluid pressure (IFP) in tumors
is a major obstacle against delivery of therapeutic agents. On the other hand,
the origin of enhanced IFP remains controversial. Here, the Van't Hoff equation
is applied to examine how glucose breakdown to CO2 and lactate in tumor cells may
affect intracellular osmotic pressure. According to the equation, it is found
that production of CO2 from glucose lowers osmotic pressure inside cells, while
glycolytic production of lactate generates significant increases. Crucial to a
net enhancement of pressure in cells is the Warburg ratio, the ratio of the
fraction of glucose transformed to lactate divided by the fraction of glucose
metabolized to CO2: if (and only if) the ratio is higher than 1.0, there is a
resulting increase in intracellular osmotic pressure. Under fully anaerobic
glycolysis, the enhancement of intracellular pressure is maximal, namely 19.3
mmHg per mM of glucose metabolized to lactate (Van't Hoff equation). Cells are
then biological pressure pumps driven by glycolytic production of lactate,
causing IFP to raise. It is proposed that a regulatory feedback loop prevents IFP
to raise above microvascular pressure (MVP). Accordingly, enhanced IFP in tumors
is the result of high rates of tumor glycolysis, and enhancement of IFP is
limited by MVP. It is thus concluded that a high rate of glycolytic production of
lactate in tumor cells ultimately prevents both access of therapeutic agents to
the malignant cells and immunological surveillance, and that it indirectly drives
outward currents of interstitial fluid, thereby propelling both the process of
tumor infiltration of surrounding structures and metastatic spread, depending on
deformability and proteolytic capacity of the malignant cells.
PMID- 10687897
TI - Could growth retardation in cystic fibrosis be partly due to deficient steroid
and thyroid hormonogenesis?
AB - Cystic fibrosis (CF) mainly affects Caucasians of northwestern-European ancestry
with severe morbidity. The individuals are malnourished and growth retarded. The
latter is thought to be the consequence of delayed maturation of the hypothalamic
pituitary-gonadal axis due to malnourishment. However, there is evidence that
steroid and thyroid hormone syntheses may be impaired in CF. Thyrotropin
stimulates the uptake and efflux of iodide before the halide is incorporated into
thyroid hormones and it is becoming apparent that gonadotropins likewise mobilise
chloride ions in Leydig cells prior to steroidogenesis. Since the primary defect
causing CF is the mutated cystic fibrosis transmembrane conductance regulator
(CFTR)--a chloride channel residing on the apical membrane of wet epithelia, the
growth retardation in CF may in part be due to deficient hormone syntheses. The
latter may involve CFTR or may be the halide channel activated by glycoprotein
hormones prior to hormonogenesis.
PMID- 10687898
TI - Occlusions of epicardial arteries might not directly induce symptoms in ischemic
heart disease.
AB - It is accepted that primary occlusions of epicardial arteries by thromboses,
stenotic coronary artery disease (CAD), and spasm directly induce symptoms in
ischemic heart disease (IHD). Because of this acceptance, there has been little
interest in alternate mechanisms for IHD--as the spasm of resistance vessel (S
RV) concept of IHD, which asserts that S-RV directly induces symptoms in IHD. To
stimulate interest in the S-RV concept, evidence against the primacy of
occlusions of epicardial arteries was presented, as well as evidence for this
position to provide a balanced discussion; while the evidence was mixed, overall
findings appeared to weigh significantly against the primacy of occlusions of
epicardial arteries. Also, the S-RV concept was discussed; the discussion
included presenting the theory's explanations for events in epicardial arteries,
with the aim of demonstrating that the concept provides more consistent
explanations than the standard position. It is suggested that there is sufficient
information to warrant renewed consideration of the S-RV concept.
PMID- 10687899
TI - Digitoxin is a potential anticancer agent for several types of cancer.
AB - The ability of digitalis to block cell proliferation has been well established
for some time. Recently, digitalis in non-toxic concentrations has been showed to
induce apoptosis in different malignant cell lines. In light of the pivotal role
of apoptosis in cancer development and progression and this new experimental
finding concerning digitalis, it seems probable that the apoptosis-inducing
capability is explained by mechanisms other than just Na+/K+ ATPase inhibition.
In this article, features of the cardiac glycosides which make them interesting
to evaluate further as potential anticancer drugs are discussed. Some new data
concerning inhibition and apoptosis in three human glioblastoma cell lines by
digitoxin are also presented.
PMID- 10687900
TI - Prognostic factors and relative risk for survival in N1-3 oral squamous cell
carcinoma: a multivariate analysis using Cox's hazard model.
AB - The records of 136 patients with N1-3 oral squamous cell carcinoma treated by
surgery were investigated retrospectively, with the aim of finding out which
factors were predictive of survival on multivariate analysis. Four independent
factors significantly influenced survival in the following order: pN stage; T
stage; histological grade; and N stage. The most significant was pN stage, the
five-year survival for patients with pN0 being 91% and for patients with pN1-3
41%. A further study was carried out on the 80 patients with pN1-3 to find out
their prognostic factors for survival and the independent factors identified by
multivariate analysis were T stage and presence or absence of extracapsular
spread to metastatic lymph nodes.
PMID- 10687901
TI - A simple method of plate fixation of fractures of the frontal bone.
AB - We present a simple method to reduce and align depressed fractures of the frontal
sinus or cranial vault before rigid fixation using microplates.
PMID- 10687902
TI - Mandibular third molars: oral surgeons' assessment of the indications for
removal.
AB - The aim was to examine oral surgeons' assessment of the indications for removal
of mandibular third molars. Questionnaires were distributed to seven oral and
maxillofacial surgery clinics. The oral surgeons were asked to record whether or
not there was associated disease. Three other factors were recorded: patient's
age, and angular position and extent of eruption of the molars. The strength of
the indication for removal was rated on a visual analogue scale (VAS) where 0=
weakest and 100= strongest indication for removal. The results were based on data
from 666 molars: 118 (18%) had no disease, 465 (70%) had one associated disease,
77 (11%) had two and 6 (1%) had three. The indication for removal as expressed by
the mean VAS for molars with no disease was assessed to be weaker (P<0.05) than
that for molars with one, two, or three diseases. The only factor that influenced
the indication for removal in molars with no disease was the patient's age.
PMID- 10687903
TI - Association between paroxysmal trigeminal neuralgia and atypical facial pain.
AB - Paroxysmal trigeminal neuralgia and atypical facial pain are both fairly common
conditions that produce pain in the face of different character. Trigeminal
neuralgia is sharp and shooting, brought on by facial movement, change of
temperature and by touching the face at a specific point (the trigger point).
Atypical facial pain is dull and unrelenting and its site is ill-defined.
Trigeminal neuralgia is generally more common in older people, and affects women
slightly more than men, and atypical facial pain generally affects younger
people, with women predominating. The pains should never be confused. We have
noticed that many patients with trigeminal neuralgia have additional symptoms of
atypical facial pain and so we reviewed the records of the Pain Relief Unit
retrospectively. Of the 83 patients identified with trigeminal neuralgia where
records were adequate, 35 (42%) also had atypical facial pain. Five of these had
developed it before the onset of trigeminal neuralgia and could be examples of
pretrigeminal neuralgia. There were eight patients in the series with multiple
sclerosis, of whom two also had atypical facial pain. There seemed to be no
relationship between the development of atypical facial pain and the
interventions used to treat trigeminal neuralgia. It is important that both
conditions are identified and treated individually.
PMID- 10687904
TI - Life-threatening haemorrhage after elevation of a fractured zygoma.
AB - A 21-year-old man presented with a fractured left zygoma after an alleged
assault. The fracture was elevated four days later, at which time he had a brisk
left-sided epistaxis. Recovery was uneventful except for a haematoma that was
drained a month later. Two weeks after this, he was admitted after having
collapsed. He was shocked and bleeding profusely from his nose. He had a further
major bleed in hospital and this was treated by tying off the left external
carotid artery. He has made an uneventful recovery and investigations have shown
no bleeding diathesis.
PMID- 10687905
TI - Alveolar soft part sarcoma of the tongue.
AB - We report a case of alveolar soft part sarcoma--a rare malignancy that presented
as a swelling at the base of the tongue in a 5-year-old child. Only about one
quarter of the few reported cases arise within the head and neck, the tongue and
orbit being the favoured sites.
PMID- 10687906
TI - Temporomandibular joint symptoms and disc displacement in patients with
mandibular prognathism.
AB - Our objective was to find out the incidence of signs and symptoms of
temporomandibular joint (TMJ) and disc displacement in patients with mandibular
prognathism. Fifty-one patients were examined clinically and by axial computed
tomography(CT). The incidence of TMJ signs and symptoms was 6/25(24%) in patients
with simple mandibular prognathism and 12/26(46%) in patients with mandibular
prognathism and asymmetry. No discs were displaced in patients with simple
mandibular prognathism, but 15(58%) of the patients with mandibular prognathism
and asymmetry had displaced discs. There was no association between signs and
symptoms of TMJ and disc displacement. Patients with mild protrusion and severe
asymmetry of the mandible had a high incidence of disc displacement, which
interestingly was on the deviated side in 14 of the 15 patients affected. We
conclude that skeletal morphology may have a role in the development of TMJ
disorders but the mechanism is obscure.
PMID- 10687907
TI - The value of magnetic resonance imaging in the diagnosis of mandibular
osteomyelitis.
AB - Our aim was to evaluate the accuracy of magnetic resonance imaging (MRI) and bone
scintigraphy in the diagnosis of mandibular osteomyelitis. Twenty patients with
mandibular osteomyelitis were prospectively investigated by conventional
radiography, bone scintigrams and MRI. All diagnoses were verified either by
surgery or by the clinical course. There was no significant difference between
bone scintigraphy and MRI in the detection of osteomyelitis or the assessment of
its extent. MRI was significantly better than scintigraphy at detecting the
presence and assessing the extent of extraosseous inflammation. We always use MRI
to diagnose osteomyelitis. For long-term follow-up of patients with mandibular
osteomyelitis, we recommend MRI and bone scintigraphy.
PMID- 10687908
TI - Upper buccal sulcus approach to management of fractures of the zygomatic complex:
a retrospective study of 50 cases.
AB - A retrospective study was conducted of 50 consecutive cases of fractures of the
zygomatic complex reduced by the upper buccal sulcus approach. All were treated
successfully with simple elevation (n=38), elevation with intraoral plating at
the zygomatic buttress (n=8), or extraoral placement of bone plates (n=4). In no
case was the approach deemed unsuitable, or abandoned in favour of another
technique. There was minimal morbidity (one case each of mild diplopia, trismus,
and swelling, all of which settled spontaneously). The upper buccal sulcus
approach is a safe, rapid and effective technique for the reduction of zygomatic
body and arch fractures.
PMID- 10687909
TI - Ostrich eggshell as a bone substitute: a preliminary report of its biological
behaviour in animals--a possibility in facial reconstructive surgery.
AB - The aim of this study was to assess the biological behaviour of an implant of
ostrich eggshell in various animal models of facial bone reconstruction. The
implant was first bioassayed in a rat muscle pouch (n=10), and then tested as an
interpositional graft in rat (n=10) and rabbit (n=5) cranial defects. It was
finally used as an onlay graft on rabbit mandibles (n=5). Animals were killed
after two months in the bioassay, three months in the interpositional model, and
six months in the onlay model. The specimens were studied by contact radiography
and standard histological techniques. All animals showed normal wound-healing. In
the bioassay, the implants produced only a minimal inflammatory reaction. In the
interpositional model, the implants maintained a good contour, but there was no
sign of graft-remodelling. In the onlay model, the grafts were stable and partly
osteointegrated. The onlay graft model gave the most promising results. Because
ostrich eggshell is inexpensive and has good mechanical properties, it deserves
further study. Long-term studies will clarify its possible role in maxillofacial
surgery.
PMID- 10687910
TI - Comparison of two techniques of patient-controlled sedation with midazolam.
AB - OBJECTIVE: To compare patient-controlled sedation with 1-mg increments of
midazolam at 1-min intervals with 0.1-mg increments of midazolam without a lock
out interval. DESIGN: Randomized cross over study. SUBJECTS: 32 patients aged 17
35 years having third molars removed. RESULTS: Doses of midazolam obtained,
degree of sedation and operating conditions were similar in the two groups. The
demands far exceeded the increments actually received by patients obtaining 0.1
mg increments. Some were extremely sedated with both techniques. CONCLUSIONS: In
this age group, there were no significant advantages or disadvantages of one
technique over the other. Patients obtained the degree of sedation they required
to undergo the operation by pressing the button independently of the dose or
incremental interval. So-called 'true' patient-controlled sedation is a misnomer.
The cut-off interval proved to be an extremely important safety feature.
PMID- 10687911
TI - Aberrations of erbB-1 and erbB-2 oncogenes in non-dysplastic leukoplakias of the
oral cavity.
AB - The purpose of this study was to analyse erbB-1 and erbB-2 oncogenes in non
dysplastic oral leukoplakia to see if we could pinpoint the first steps towards
dysplasia and possible carcinogenesis. Fresh biopsy specimens of leukoplakia in
13 patients with no history of oral cancer were examined using the competitive
differential polymerase chain reaction. The mean gene copy numbers of erbB-1 and
erbB-2 were calculated from the formula to compare the absolute quantities of
reference gene and oncogene from 24 patients who did not have leukoplakia.
Healthy mucosa was taken as controls. In eight patients with leukoplakias, the
results indicated aberrations of the erbB-1 oncogene, and two patients had gene
dosage changes of erbB-2. There were no signs of deletions or amplifications in
the controls. These results suggest that aberrations of erbB-1 and erbB-2 are
additional markers in premalignant oral lesions at the beginning of the
carcinogenic process, and that genetic alterations in histologically non
dysplastic premalignant oral lesions are common.
PMID- 10687912
TI - Distraction implants--a new possibility for augmentative treatment of the
edentulous atrophic mandible: case report.
PMID- 10687913
TI - A cephalometric study of the relationship between the level of velopharyngeal
closure and the palatal plane in patients with repaired cleft palate and controls
without clefts.
AB - To find out whether the palatal plane is a useful indicator for evaluating the
level of velopharyngeal closure, we did a cross-sectional study from early
childhood to puberty of the vertical relationship between the palatal plane and
the level of velarpharyngeal contact during velopharyngeal functioning in 61
patients with repaired cleft palate (unilateral cleft lip and palate = cleft
group) and 82 controls without clefts (control group). Measurements on the
vertical dimension were derived from a coordinate system and landmarks on lateral
cephalograms, and the significance of differences in measurements was analysed
using Student's t-test. Changes in the points of velarpharyngeal contact in
relation to the palatal plane with growth showed a consistent tendency though
differed between the two groups. In the control group, the PPW (point where
palatal plane extension intersects the posterior pharyngeal wall) was maintained
at a level that did not differ significantly from the level of midpoint of
velarpharyngeal contact during phonation of /a/, and was maintained at a level
that did not differ significantly from the level of the inferior point of
velarpharyngeal contact. In the cleft group, however, it was maintained at a
level that was slightly higher than the superior point of velarpharyngeal contact
both during phonation of /a/ and during blowing. These results suggest that the
palatal plane is useful as an indicator for evaluating the level of
velopharyngeal closure.
PMID- 10687914
TI - Effects of surgical reduction of the tongue.
AB - There are still no objective diagnostic criteria for macroglossia. The aims of
this study were to examine the effect of reduction of the tongue on its position,
and to suggest a standard measurement point for the objective diagnosis of
macroglossia. Twenty-four patients were studied. Lateral cephalometric
radiographs were taken with the tongue in the rest position, and preoperative and
postoperative measurements were made on cephalometric lateral roentgenograms from
all 14 patients with macroglossia and the 10 control subjects. The results
suggested that measurement of length of the tongue, and the tongue area: oral
cavity ratio on lateral cephalometric radiographs are useful in the more accurate
diagnosis of macroglossia.
PMID- 10687915
TI - Device for collecting bone from the ilium for bone transplantation in cleft jaw.
PMID- 10687916
TI - Specialist practitioner' in surgical dentistry: preliminary report on a pilot
scheme at East Surrey Hospital, Redhill, UK.
AB - This continuing pilot scheme was designed to assess whether minor oral operations
could be done by a 'specialist practitioner' in surgical dentistry in hospital.
The preliminary results indicate that patients benefit from the improved
facilities and expertise that are available in the hospital, that the provision
of treatment within the hospital is at a sufficiently 'local' level to meet their
requirements, and that this increased quality of service can be provided at no
greater cost to the NHS than treating them in a dental surgery. A large amount of
the dentoalveolar surgery done (such as removal of third molars) is regarded as
routine, but 'routine' is often mistakenly thought to mean 'simple' or 'easy'.
Dentoalveolar surgery not only demands the highest quality of care and expertise
but it also requires the necessary immediate support if medical or surgical
complications arise.
PMID- 10687917
TI - Need for intensive care after operations for head and neck cancer surgery.
AB - We compared the postoperative morbidity of 44 patients who had had major head and
neck oncological resections and who were nursed postoperatively on a general ward
with that of 33 who were nursed on an intensive care unit at North Manchester
General Hospital and Withington Hospital, South Manchester, respectively. There
was no difference in the general morbidity (9/44, 20% compared with 9/33, 27%,
95%, CI of difference -0.26 to 0.13). We conclude that it is safe to nurse the
patients on a general ward provided that certain conditions are fulfilled.
PMID- 10687918
TI - Re: Bos et al. A randomised controlled trial of the management of mandibular
condyle fractures.
PMID- 10687919
TI - Re: Edwards et al. Choice of anaesthetic and health care facility for third molar
surgery.
PMID- 10687920
TI - Wisdom tooth removal and lingual nerve damage.
PMID- 10687921
TI - Re: Flood et al. Randomized prospective study of the influence of steroids on
postoperative eye-opening after exploration.
PMID- 10687922
TI - Re: Flood et al. Randomized prospective study of the influence of steroids on
postoperative eye-opening after exploration of the orbital floor.
PMID- 10687923
TI - Double bond content of phospholipids and lipid peroxidation negatively correlate
with maximum longevity in the heart of mammals.
AB - Free radical damage is currently considered a main determinant of the rate of
aging. Unsaturated fatty acids are the tissue macromolecules most sensitive to
oxidative damage. Therefore, the presence of relatively low degrees of fatty acid
unsaturation is expected in the tissues of longevous animals. In agreement with
this prediction, fatty acid analyses of heart phospholipids in eight mammals
ranging in maximum life span (MLSP) from 3.5 to 46 years showed that their total
number of double bonds is negatively correlated with MLSP (r = -0.78, P < 0.02).
The low double content of longevous mammals was not due to a low polyunsaturated
fatty acid content. Instead, it was mainly due to a redistribution between types
of polyunsaturated fatty acids from the highly unsaturated docosahexaenoic acid
(22:6n-3) to the less unsaturated linoleic acid (18:2n-6) in longevous animals (r
= -0.89, P < 0.003 for 22:6n-3 and r = 0.91, P < 0.002 for 18:2n-6 versus MLSP),
where n = number of different animals in each species. This redistribution
suggests that one of the mechanisms responsible for the low number of fatty acid
double bonds is the presence of low desaturase activities in longevous animals,
although other causing factors must be involved. In agreement with the low degree
of fatty acid unsaturation of longevous mammals, the sensitivity to lipid
peroxidation (r = -0.87; P < 0.005) and the in vivo lipid peroxidation (r =
0.86, P < 0.005) in the heart were also negatively correlated with MLSP across
species. These results, together with previous ones obtained in rodents, birds,
and humans, suggest that the low degree of tissue fatty acid unsaturation of
longevous homeothermic animals could have been selected during evolution to
protect the tissues against oxidative damage.
PMID- 10687924
TI - Short-term calorie restriction improves disease-related markers in older male
rhesus monkeys (Macaca mulatta).
AB - Calorie restriction (CR) is widely known for its effects on life span,
physiological aging and age-related disease in laboratory rats and mice. Emerging
data from CR studies in rhesus monkeys suggest that this nutritional intervention
paradigm may also have beneficial effects in long-lived mammals. Studies from our
laboratory and others have suggested that young- or adult-onset CR might have
beneficial effects on cardiovascular disease and diabetes. For example, long-term
CR reduced body fat and serum triglycerides, and increased a subfraction of HDL
cholesterol associated with decreased cardiovascular disease risk. These studies
suggested that long-term CR begun in young or adult animals might have important
effects on markers relevant to age-related disease. Few studies have examined the
effects of CR initiated in older animals (rodents or monkeys), and the temporal
nature of some potentially beneficial effects of CR is unknown. The present study
examined several markers related to diabetes and cardiovascular disease in
thirteen older adult (> 18 year) non-obese (body fat < 22%), male rhesus monkeys
during a short-term CR paradigm. Specifically, we collected these data at
baseline (ad libitum feeding), 10, 20, and 30% CR, and at 6 and 12 months on 30%
CR. Fasting and peak insulin were significantly reduced as were the acute and
second-phase insulin responses. CR also marginally reduced triglycerides (50%
reduction), but had no effect on total serum cholesterol or blood pressure.
Interestingly, the observed glucoregulatory changes emerged prior to any evidence
of a change in body composition suggesting that certain effects of CR may not be
wholly dependent on changes in body composition in older monkeys.
PMID- 10687925
TI - Genetic differences in the age-associated decrease in inducibility of natural
killer cells by interferon-alpha/beta.
AB - Natural killer (NK) cells, which are important in viral infections and anti-tumor
activity, show reduced cytotoxicity in aged mice. The mechanism(s) for this age
related decline in NK activity has not been clearly established. We assessed
changes in NK cytotoxicity in splenocytes and peripheral blood mononuclear cells
after interferon (IFN)-alpha/beta stimulation in adult (6 months) and aged (22-26
months) C57Bl/6, Balb/c, and (Balb/c x C57Bl/6)F1 mice. Aged C57Bl/6 and Balb/c
mice had a significantly reduced IFN-alpha/beta-stimulated NK cytotoxicity
compared to adult mice. In contrast, adult and aged F1 mice showed similar NK
cytotoxicity after IFN-alpha/beta induction. The decreased ability of NK cells of
aged mice to respond to induction by IFN-alpha/beta was not due to a requirement
for an increased amount of IFN or for a longer period of treatment with IFN.
Further, this decreased response did not appear to be the result of suppressive
activity of adherent cells or T cells. While the percentage of NK cells (NK1.1+)
was similar in adult and aged mice, the (CD8+ NK1.1+) subset of NK cells was
significantly increased in aged mice. Importantly, the percentage of CD8+ NK1.1+
cells was inversely related to the cytotoxicity observed after IFN-alpha/beta
treatment.
PMID- 10687927
TI - Sudden senescence syndrome plays a major role in cell culture proliferation.
AB - Normal human cells of various types have a finite and predictable proliferative
potential in vitro. This limited life span is due to a gradually increasing
fraction of senescent cells that appear in the culture in a sudden and stochastic
fashion due to a phenomenon referred to as sudden senescence syndrome (SSS).
Because nondividing cells increasingly accumulate in the culture, dividing cells
have to compensate for nondividers in order to accomplish additional population
doubling (PD). Thus, individual dividing cells undergo more divisions, called
cell generations (CG), than the number of PDs. Based on integrated experimental
data, we calculated maximum CG for normal human diploid fibroblasts (HDF). It
appears that for a HDF culture that undergoes 65 PD, the calculated final CG is
at least 126. Based on the obtained value for CG we calculated the total size of
the culture, both with and without effect of SSS. If no SSS takes place and cells
divide by geometrical progression, the culture will grow up to 2(126) or 10(38)
cells. By constantly eliminating cells from further divisions, causing cell loss
(CL), SSS reduces the total size of the culture at every point during its
proliferation. The calculated value for CL is enormous, so that the culture of
10(38) cells is reduced to only 10(19) cells, thus as little as 10(-17)% of its
size! Accordingly, by preventing virtually every cell in the culture from
reaching its original maximum doubling capacity, SSS appears to be the most
important mechanism that influences cell culture proliferation.
PMID- 10687926
TI - Mechanical stress enhances expression and production of plasminogen activator in
aging human periodontal ligament cells.
AB - Plasminogen activator (PA) converts plasminogen to plasmin, and plasmin activates
the kinin cascade and latent extracellular matrix metalloproteases. The
periodontal ligament serves to anchor the tooth to the alveolus and functions as
a cushion between these hard tissues to migrate occlusal force during
mastication. We reported previously that repeated mechanical tension force (MTF)
as an experimental model of a traumatic occlusion, increased PA activity in human
periodontal ligament derived fibroblast (hPLF) cells. In this study, the
influence of in vitro cellular aging on MTF-stimulated PA activity in hPLF cells
was studied. Aged hPLF cells produced a significantly higher PA activity when
compared with those of young hPLF cells in response to MTF in a time- and
magnitude-dependent manner. tPA mRNA levels in aged cells were higher than those
in young cells, whereas PAI-1 mRNA remained unchanged and uPA mRNA was not
detected. Because MTF-stimulated PA activity from hPLF cells was increased by in
vitro cellular aging, aging of the periodontal ligament may affect the severity
of the inflammation and the degradation of the extracellular matrix of
periodontal ligament tissue by producing a large amount of PA in response to
excessive force such as a traumatic occlusion.
PMID- 10687928
TI - Tone burst-evoked myogenic potentials in human neck flexor and extensor.
AB - Vestibular evoked myogenic potential (VEMP) has been proposed to be a
manifestation of sacculocollic reflex. In a recent study using intracellular
recording from neck flexor and extensor motoneurons, the neuronal connections and
pathways underlying sacculocollic reflexes were determined in cats. The results
showed that sacculocollic reflex displayed inhibitory connection to bilateral
neck flexors and excitatory connection to bilateral neck extensors. A total of 16
normal young adults were tested with bilateral recordings of sternocleidomastoid
(SCM) and splenius capitis (SC) muscles by acoustic stimulus of 500 Hz short tone
burst. The results revealed that polarity of the wave I/II of VEMP on SC was the
reverse of that on SCM. This implied that VEMP from ipsilateral SCM showed
inhibitory neural activity; whereas VEMP from ipsilateral SC was an excitatory
response. Using this non-invasive technique, the sacculocollic reflexes in human
neck flexor and extensor were studied. The results in humans were consistent with
the previous findings in cats.
PMID- 10687929
TI - Benign paroxysmal positional vertigo (BPPV): idiopathic versus post-traumatic.
AB - Between October 1974 and August 1997 in our Dizziness Clinic (n = 15,233), 2,523
patients were found to suffer from BPPV. All patients were assessed and followed
up by the author. Patients (n = 337) having other ear or neurological diseases
were excluded from this retrospective study. In 1644/2186 (75.21%) patients, the
type of nystagmus was clinically identified in two opposite directions of gaze in
the provocative head position. These patients were divided into two groups: i)
idiopathic (n = 1,490) (no apparent cause); ii) post-traumatic (n = 154) (time of
onset related to accident). It was found that in the idiopathic group men were
older than women; women were more affected than men (2.3:1), and in the post
traumatic group there was no age difference between men and women; women and men
were equally affected (1:1). In addition: i) patients were older in the
idiopathic than the post-traumatic group. ii) BPPV of the posterior (PSC) was by
far more prevalent than BPPV of the horizontal semicircular canal (HSC) in both
groups, although there was no difference in prevalence between the two groups.
iii) Bilateral involvement was more prevalent in the post-traumatic group. iv)
All bilateral cases in both groups suffered from BPPV of the PSC. It is concluded
that despite similarities, these two groups differ in a number of parameters.
Thus the pathophysiology and the course of idiopathic vs post-traumatic BPPV may
also be different.
PMID- 10687930
TI - Vestibulo-ocular responses during static head roll and three-dimensional head
impulses after vestibular neuritis.
AB - This study aimed to investigate whether unilateral vestibular neuritis (VN)
causes the same deficits of ocular counter-roll during static head roll (OCR(S))
and dynamic vestibulo-ocular reflex gains during head impulses (VOR(HI)) as
unilateral vestibular deafferentation (VD). Ten patients with acute and 14
patients with chronic vestibular paralysis after VN were examined. The testing
battery included fundus photography of both eyes with the head upright (binocular
cyclorotation) and dual search coil recordings in a three-field magnetic frame.
With one dual search coil on the right eye and the other on the forehead, the
following stimuli were given: i) Halmagyi-Curthoys head impulses about the
vertical, horizontal and torsional axes. ii) Static roll positions of the head up
to 20 degrees right- and left-ear-down by movement of the neck. The comparison
group consisted of 19 healthy subjects. Compared with the VD-patients, as
reported in the literature, acute VN-patients showed the same pattern of OCR(S)
gain reduction and binocular cyclorotation (CRb). The main feature that
distinguished chronic VN-patients from chronic VD-patients was the normalization
of the torsional VOR(HI) gain to the affected side, whereas the VOR(HI) gains in
the horizontal and vertical directions did not show recovery (as in the patients
with chronic VD). Chronic VN-patients differed from acute VN-patients by: i)
symmetrical OCR(S) gains, ii) a less pronounced CRb toward the affected side, and
iii) a normal torsional VOR(HI) gain toward the affected side. Since the
ipsilesional torsional VOR(HI) gain did not recover in VD-patients, the
normalization of this gain in our VN-patients can only be explained by a
(partial) recovery of otolith function on the side of the lesion after the
neuritis.
PMID- 10687931
TI - Hypotension and sensorineural hearing loss: a possible correlation.
AB - A possible role of hypotension in the genesis of sudden or slowly developing
sensorineural hearing loss has been outlined. In order to confirm this
hypothesis, and to exclude other vascular risk factors, a prospective study was
carried out within the "Brisighella Study", a wide and homogeneous group of
subjects thoroughly examined from a metabolic and cardiovascular point of view.
Among them, 20 participants aged 50 years or less (18 women, 2 men) with
diastolic blood pressure < or = 60 mmHg and/or systolic blood pressure < or = 105
mmHg were selected and underwent otological and audiometric examinations.
Patients with previous audiological, vestibular and otological diseases were
excluded. The control group was represented by 100 subjects (60 women, 40 men),
aged 50 years or less, randomly chosen from within a sample of the normal
population in the same region. A statistically significant incidence of
sensorineural hearing loss was recorded in the study group (7/20 subjects, all
affected by low-frequency hearing loss), while hearing impairment was observed in
only 3/100 participants in the control group. The mean values of the main
metabolic parameters were normal. An alteration of the vasomotor system
associated with a hypotensive condition could be responsible as a possible factor
in the origin of a cochlear damage and the consequent sensorineural hearing loss.
PMID- 10687932
TI - Clinical utility of LDL-apheresis in the treatment of sudden hearing loss: a
prospective, randomized study.
AB - Although the pathogenesis of sudden hearing loss (SHL) is not as yet known, the
clinical picture and the frequent association with vascular risk factors make an
ischaemic event likely. This study aimed to assess the effect of an
extracorporeal procedure (H.E.L.P.) in removing LDL-cholesterol, fibrinogen and
lipoprotein (a) from the plasma, on the recovery of hearing SHL. This procedure
using the HELP-system was compared with the usual standard treatment with
prednisolone, dextranes and pentoxifyllin. We undertook a single centre,
prospective, randomized study in which 18 patients were assigned to H.E.L.P.
apheresis and 9 patients were assigned to standard treatment (2:1 randomization).
Audiometric and laboratory testing was performed at baseline, 24 h and 6 weeks
after start of treatment. Primary endpoint was the improvement of the average
pure-tone threshold between 0.125 and 8 kHz after 24 h. Twenty-four hours after
H.E.L.P. treatment average pure-tone threshold recovered by 10.4 dB and by 26.4
dB after 6 weeks. The recovery of hearing of the standard treated patients was
5.8 dB and 16.8 dB after 24 h and 6 weeks respectively. LDL-cholesterol,
fibrinogen and lipoprotein (a) were significantly reduced in the HELP treated
patients compared with standard therapy, resulting in a significant improve in
plasma viscosity, erythrocyte aggregation and resistance to oxidative stress of
LDL particles. Our results suggest that the clinical outcome of SHL after a
single extracorporeal LDL-apheresis is superior or at least equal to the more
expensive standard treatment with prednisolone, dextranes and pentoxifyllin. Re
establishment of vascular endothelial function and improved blood rheology may be
the underlying cause. These results must be confirmed in larger-scale trials.
PMID- 10687933
TI - Evaluation of inner ear histology and auditory brainstem response in Wriggle
Mouse Sagami.
AB - Wriggle Mouse Sagami (WMS) is a spontaneous mutant strain with neuroepithelial
defects. These animals are characterized by abnormal movements linked to an
autosomal recessive gene. To determine the association between inner ear
histology and hearing ability, we assayed these characteristics in mice
homozygous and heterozygous for the mutation, as well as in wild-type animals. In
homozygotes, the cochlea and saccule degenerated 3 months after birth. Beginning
at 3 months of age, and progressing in an age-dependent manner, the organ of
Corti disappeared and the number of spiral ganglion cells decreased, starting at
the basal turn and moving toward the apical turn. The sensory epithelium became
atrophic in the saccule. Three-month-old heterozygotes demonstrated degeneration
in the cochlea, not in the saccule. No obvious auditory brainstem evoked response
(ABR) was observed at any frequency in homozygotes aged 1 month and older. In
contrast, the heterozygotes retained some hearing acuity until the age of 1
month, after which they became deaf. These findings suggest that WMS mice may
provide a good model that will be useful in identifying deafness genes in humans.
PMID- 10687934
TI - Cochlear hook anatomy: evaluation of the spatial relationship of the basal
cochlear duct to middle ear landmarks.
AB - The cochlear hook is an important anatomical area for the otologist performing
cochlear implants and other otological procedures, who requires knowledge of the
basal cochlea. A total of 15 human temporal bones were dissected and the spatial
relationship of the hook segment of the cochlear duct to the stapes, round
window, cochleariform process and ductus reuniens were evaluated. Inter
individual variability was noted for widths of scala tympani (average width 1.36
+/- 0.25 mm) and scala vestibuli (average width 1.18 +/- 0.18 mm) in the region
of typical cochlear implant placement, with the scala vestibuli occasionally
being wider than the scala tympani. The cochlear duct was in closest proximity to
the stapes at the midportion of the footplate, with an average distance of 1.23
mm at this narrowest width. A fibrous anchor, not previously described in otology
literature, was identified securing the most basal end of the cochlear duct.
Knowing the spatial relationship of the cochlear duct to the middle and inner ear
structures could prevent damage to the basilar membrane in procedures around or
involving the basal cochlear, such as cochlear implantation, stapedotomy, or
implantable hearing devices.
PMID- 10687935
TI - Morphological changes induced by administration of a Na+,K+-ATPase inhibitor in
normal and hydropic inner ears of the guinea pig.
AB - The objective of this study was to determine the effects of ouabain, a Na+,K+
ATPase inhibitor, in inner ears. Administering ouabain locally through the round
window and vestibule, resulted in degenerative changes in cochlear and vestibular
sensory cells and limbal fibrocytes, but the stria vascularis and spiral ligament
were less affected. The position of Reissner's membrane was rarely changed.
Vacuolar spaces in the sensory epithelia of cristae, maccula utriculi and macula
sacculi increased in number. Nystagmus was a common occurrence with or without
demonstrating degeneration of vestibular sensory cells. By administering ouabain
systemically, the course of developing endolymphatic hydrops could not be altered
in the ears with endolymphatic duct blockage. Edema of nerve endings of inner
hair cells and vestibular sensory cells was frequently observed with
administration of a high concentration of ouabain in both normal and hydropic
ears, but edema was reversible. Degeneration of some vestibular sensory cells
were observed in hydropic ears with a long survival time. The mechanism of
selective sensitivity or non-sensitivity of inner ear tissues to ouabain is
discussed.
PMID- 10687936
TI - Improved RNA analysis for immediate autopsy of temporal bone soft tissues.
AB - RNA analysis is essential for understanding biological activities of a cell or
tissue. Unfortunately, retrieval of RNA from existing archives of human temporal
bones has proven extremely difficult due to degradation of RNA molecules. The
major factors that contribute to degradation of RNA in specimens from autopsied
temporal bones are tissue autolysis due to time elapsed before autopsy, and
technical problems in processing the bones after harvest. We therefore focused on
improving the survival of RNA in human temporal bones by shortening the time to
autopsy and through modification of the processing technique by removing targeted
tissues directly from the temporal bones and by avoiding time-consuming
decalcification and celloidin-embedding. Eight temporal bones collected at
immediate autopsies were used in this study. Representative mRNAs, ranging from
high (MUC5B, physically unstable) to low (beta-actin, physically stable)
molecular weights, and from abundant (MUC5B) to non-abundant (MUC1) RNA, were
studied by in situ hybridization, Northern blot technique, or both. Using this
modified protocol in autopsies performed up to 6 h after death, the existence of
mRNAs was demonstrated in all bones studied. This improved method demonstrates
the feasibility of the use of autopsied temporal bone tissues for RNA analysis.
PMID- 10687937
TI - Management of intrameatal vestibular schwannoma.
AB - The growth of purely intrameatal vestibular schwannoma (VS) was investigated, in
the period 1973-96 in a series of 40 patients with 40 unilateral VS. In the
present study, the material was analysed and updated. By the end of the
observation period (mean 3.6 years), 27 tumours (67.5%) revealed growth and 13
tumours (32%) had no measurable growth. Four growth patterns were observed: (A)
15 tumours (37.5%) exhibited constant growth; (B) 13 tumours (32.5%) had no
measurable growth; (C) 8 tumours (20%) revealed growth subsequent to a no-growth
period; and (D) 4 tumours (10%) showed different growth patterns during the
observation period. The annual diameter growth rate ranged between 00 mm/year and
6.5 mm/year and the mean diameter growth per year was 3.2 mm. The findings of the
present study, especially those for group B (the non-growing tumours) and C
(tumour growth subsequent to a silent period) bring into question the reliability
of the results achieved by radiosurgery, as without any intervention it may be
that no tumour growth occurs.
PMID- 10687938
TI - Expression of vascular endothelial growth factor in otitis media.
AB - Increased vascular permeability and endothelial cell growth are important in the
pathogenesis of otitis media with effusion (OME) and the vascular endothelial
growth factor (VEGF) is known to play an important role in the increased vascular
permeability and angiogenesis. To date, at least five isoforms of the VEGF family
have been identified as VEGF transcripts, encoding polypeptides of 206, 189, 165,
145 and 121, but their physiological roles are unclear. The purpose of this study
was to investigate the expression of VEGF, in both endotoxin-induced OME of the
rat and human otitis media. We instilled endotoxin and saline as a control into
the middle ear cavity of the rat. Middle ear mucosa were taken at 0 h, 1 h, 3 h,
6 h, 12 h, 1 day, 3 days, 7 days and 14 days and the expression of VEGF mRNA and
VEGF protein was evaluated using semi-quantitative RT-PCR and
immunohistochemistry. Expression of VEGF164 mRNA and VEGF120 mRNA was first
identified 1 h after endotoxin instillation and was dramatically increased over
the period 6 h-1 day and then progressively decreased by day 7. The level of
expression of VEGF120 mRNA was slightly higher than that of VEGF164 mRNA and that
of VEGF164 mRNA was much higher than that of VEGF188 mRNA. Immunostaining
revealed expression of VEGF during 6 h to day 3 and its expression was localized
to ciliated cells and some inflammatory cells. We also performed RT-PCRs of cDNA
from middle ear fluids of 8 human OME patients and middle ear mucosa of 4 chronic
otitis media patients for the identification of VEGF mRNA expression. VEGF121
mRNA was highly expressed in all samples compared with VEGF165 mRNA. These
results suggest that VEGF may be primarily responsible for increased vascular
permeability and endothelial cell growth in OME and that VEGF seems to play a
significant role in the pathogenesis of OME.
PMID- 10687939
TI - Continuous long-term measurements of the middle ear pressure in subjects with
symptoms of patulous eustachian tube.
AB - Direct middle ear (ME) pressure measurements during 24 h and tubal function tests
were performed on 11 subjects with the clinical diagnosis patulous Eustachian
tube (PET). The pressure was recorded from the ME via a perforation in the
tympanic membrane. The method used has previously been reported in a study on
subjects with normal ME function and no symptoms of PET: a normal group. Results
from tubal function tests correlated well with the clinical diagnosis of PET and
the sniff test was positive in most subjects. Continuous ME pressure measurements
during normal everyday and night-time activities showed no indications of
pressure changes induced by sniffing. Subjects with the clinical diagnosis PET
did not have a static state of an open ET. The ME pressure varied during the day
and night, indicating that the function of the ET changed over time from a closed
to an open state. Subjects with PET had a long-term pressure pattern
significantly different from that of a normal group, a difference seen in the
erect as well as in the recumbent position during the night. The subjects
demonstrated a negative mean pressure level in the recumbent position during the
night, whereas the normal group had a slight positive mean pressure. The
difference was statistically significant. Many subjects demonstrated frequent
slow rate negative pressure trends during normal day-time and night-time
activities. Long-term continuous pressure measurements seem to add valuable
information to that of conventional tubal function tests.
PMID- 10687940
TI - Eotaxin synthesis by nasal polyp fibroblasts.
AB - Nasal polyps is a chronic inflammatory disease of the upper airway characterized
by structural abnormalities including stromal fibrosis. Fibroblasts are a rich
source of cytokines and inflammatory mediators and are thought to play an
important role in the development of fibrosis. In addition, there is considerable
evidence for the participation of eosinophils in the pathophysiology of nasal
polyps. Although increased numbers of eosinophils are present in nasal polyps,
the mechanisms responsible for their selective accumulation are not completely
clear. Eotaxin is a chemokine that promotes the selective recruitment of
eosinophils. Thus, it may be an important molecule for the recruitment of
eosinophils in nasal polyps. The purpose of this study was to investigate whether
nasal polyp fibroblasts synthesize eotaxin after stimulation with
lipopolysaccharide, IL-1beta or TNF-alpha. Using primary nasal polyp tissue
derived fibroblast lines, we demonstrated that LPS, IL-1beta and TNF-alpha
induced the gene expression and protein production of eotaxin in nasal polyp
fibroblasts. This responsiveness to LPS, IL-1beta and TNF-alpha was time- and
dose-dependent. These findings support the hypothesis that fibroblasts could play
an important role in the recruitment of eosinophils in nasal polyps through the
production of eotaxin.
PMID- 10687941
TI - Ciliostimulatory effects mediated by nitric oxide.
AB - Ciliostimulation induced by various transmitters has been suggested to be
mediated by the release of nitric oxide (NO). Freshly obtained adenoid tissue
explants were pre-treated with the nitric oxide synthase (NOS) inhibitor N(G)
nitro L-arginine (L-NNA), to determine whether the ciliostimulators terbutaline,
methacholine, substance P, and endothelin-1 require the release of NO to increase
ciliary beat frequency (CBF) in vitro. The L-NNA pre-treatment affected the
change in CBF induced by each of the ciliostimulators tested. To determine
whether cyclic nucleotides also stimulate CBF by inducing the release of NO, an
extra series of experiments were performed with dibutyryl cAMP and dibutyryl
cGMP, and L-NNA pre-treatment. In contrast to the experiments with the various
ciliostimulators, both dibutyryl cAMP and dibutyryl cGMP exerted ciliostimulatory
effects that could not be inhibited by L-NNA. The present findings suggest that
NO acts as an intermediate messenger in the ciliated epithelium in response to
various transmitters and mediators. On the other hand, pre-treatment with the NOS
inhibitor L-NNA did not affect ciliary response to the second messengers cAMP and
cGMP, thus suggesting that NO dependent mechanisms do not constitute the sole
pathway for the stimulation of ciliary function.
PMID- 10687942
TI - Microsurgical endonasal decompression in dysthyroid orbitopathy.
AB - Diagnosis of thyroid eye disease can be established by its history, signs,
symptoms, clinical and laboratory findings of an autoimmune thyroid disease.
Therapy for this disease is limited to a few options, which should be
administered depending on its stage and inflammatory activity. When medication
and radiation therapy fail indications for decompression are: loss of visual
acuity or visual field defects, increasing strabism and severe keratopathy due to
eyelid retraction. Numerous surgical decompression techniques have been described
in endocrine orbitopathy. We have adopted endonasal microsurgery, because this
technique gives the freedom to work bimanually, ensures a stereomicoscopic view
of the intranasal landmarks of orbital walls and allows simultaneous
decompression of the medial and inferior orbital wall as well as a good relief of
pressure at the orbital apex. Decompressions were performed on 27 orbits in 17
patients, via the endonasal microsurgical, 3 via external approach. The
microscopic approach was entirely comparable with regard to reduction of
proptosis with a mean improvement of 4.1 mm against a mean of 4.7 mm by external
approach and a mean 0.2 of better visual acuity in both procedures. The
microsurgical technique is considered superior to an external approach avoiding
external scars, neural pains and reportedly less diplopia. Also, trauma to the
nalolacrimal and nasofrontal ducts are avoided. The healing phase and the
hospitalization time is shorter.
PMID- 10687943
TI - Bacterial interference in the nasopharynx and nasal cavity of sinusitis prone and
non-sinusitis prone children.
AB - The aim of this study was to compare the frequency of recovery of potential
pathogens and aerobic and anaerobic interfering bacteria in the nasopharynx and
nasal cavity of sinusitis prone (SP) children, with their recovery in non
sinusitis prone (N-SP) children. Nasopharyngeal and nasal cultures were taken
from 20 SP and 20 N-SP children. Potential pathogens and aerobic and anaerobic
bacteria with interfering capabilities against these micro-organisms were
identified. Twenty-one potential pathogens (1.05 patient) were isolated from
nasopharyngeal cultures from 14 of the 20 SP children, and 10 (0.5 patient) were
recovered from 6 of the 20 NSP (p < 0.05). Bacterial interference between two
aerobic (alpha and non-haemolytic streptococci) and two anaerobic species
(Prevotella and Peptostreptococcus species) and four potential pathogens was
observed. Bacterial interference was noted in 64 instances against 4 potential
pathogens by 24 normal flora isolates that were recovered from 7 of the SP group
and in 144 instances by 47 isolates from 18 of the NSP group (p < 0.05). Nineteen
potential pathogens (0.95/patient) were isolated from nasal cultures of 13 of the
20 SP children and 8 (0.4/patient) were recovered from 5 of the 20 NSP (p <
0.05). Bacterial interference by similar micro-organisms was noted in 21
instances by 9 normal flora isolates that were recovered from 5 of the SP group,
and in 63 instances by 26 isolates from 15 of the NSP group (p < 0.05). Our
findings illustrate for the first time that the nasopharyngeal and nasal flora of
NSP children contains more aerobic and anaerobic micro-organisms with interfering
capability and less potential pathogens than that of SP children.
PMID- 10687944
TI - Effects of sustained-release oral phenylpropanolamine on the nasal mucosa of
healthy subjects.
AB - Phenylpropanolamine (PPA) is widely used as a nasal decongestant administered
orally in sustained release preparations and, in Sweden, the recommended dose
nowadays is 50 mg twice daily for adults. The aim of this placebo-controlled,
cross-over study was to determine the onset and duration of the decongestive
effect of 50 and 100 mg PPA in 15 healthy subjects. All subjects arrived at the
laboratory at 07.30 h. After an acclimatisation, the nasal mucosal baseline was
established with rhinostereometry and the minimal cross-sectional area was
measured using acoustic rhinometry. The systolic and diastolic blood pressures
were also determined. Then all subjects were given their study drugs for the day
and the measurements were repeated every hour for 8 h. This procedure was
repeated for 3 days at 48 h intervals between the days. For purposes of
comparison, the decongestive effect of oxymetazoline nasal spray was studied on a
separate day. The decongestive effect of 100 mg PPA was similar to that of
topical oxymetazoline. It develops after 1 h and lasts for approximately 6 h. The
decongestive effect of oxymetazoline was significantly greater than that of 50 mg
PPA and that of 100 mg PPA was significantly greater than that of 50 mg PPA using
rhinostereometry, but not when using acoustic rhinometry. However, 50 mg PPA had
no significant decongestive effect, compared with placebo, with rhinostereometry
or acoustic rhinometry. In the first 3 h after administration of PPA, there was a
dose-response increase in the systolic and diastolic blood pressures, which then
returned to baseline. In conclusion, this study shows that PPA in double the
recommended dose, i.e. 100 mg, has a significant decongestive effect on the nasal
mucosa in healthy subjects. However, when the dose of PPA is increased the
systolic and diastolic blood pressures also increase.
PMID- 10687945
TI - Postnatal changes in the types of muscle fibre in the canine inferior pharyngeal
constrictor.
AB - Deglutition is considered to be immature in infants and to mature postnatally. We
evaluated postnatal changes in muscle fibre type composition in the canine
inferior pharyngeal constrictor muscle, which consists of the thyropharyngeal
(TP) and cricopharyngeal (CP) muscles, using ATPase staining with respect to the
maturation of deglutition. In the TP muscle type IIA and type IIB fibres, the
main components in the adult, were already predominant at 1 week postnatally. The
percentage of primitive type IIC fibre showed a rapid reduction and reached the
adult level within 6 weeks. In the CP muscle, the majority of fibres were type
IIC at 2 weeks. At 2 months, more than 20% of the fibres were still type IIC and
the proportion of type I fibres as a main component in the adult was smaller than
that of the adult. None of the puppies younger than 9 weeks old had a fibre type
composition similar to that of the adult. In the extensor digitorum longus and
flexor digitorum superficialis, the compositions of muscle fibre types became
similar to that of the adult at 6 and 9 weeks of age, respectively. Thus, the TP
muscle matured more rapidly than the limb muscles, while the CP muscle matured
more slowly. We speculated that the TP and CP muscles have specific individual
differentiation patterns associated with their functional roles before and after
birth, compared with the limb muscles.
PMID- 10687946
TI - Glottic and supraglottic laryngeal carcinoma: differences in epidemiology,
clinical characteristics and prognosis.
AB - In order to evaluate differences in epidemiology, clinical characteristics and
prognosis, 166 glottic and 127 supraglottic cases of laryngeal squamous cell
carcinoma diagnosed between 1962 and 1991 at Tampere University Hospital,
Finland, were reviewed. The annual age-adjusted incidence in males decreased from
6.7/100,000 to 2.6/100,000 and the proportion of glottic tumours increased from
one-third to two-thirds during the study period. The proportion of early stage
lesions was greater among glottic tumours, and patients with a supraglottic
tumour presented more often with neck node metastases. Hoarseness was the most
common symptom, being more prevalent in patients with a glottic tumour. The
symptom pattern of supraglottic carcinoma was altogether more diffuse. The 5-year
disease-specific survival was 81% in glottic and 70% in supraglottic disease, but
the difference in survival was not statistically significant. In the multivariate
Cox regression analysis, higher T-category and presence of neck node metastases
had adverse prognostic effect, while location of the tumour did not significantly
affect the prognosis. Favourable changes in smoking habits seem to be the main
reason for the incidence decrease and obviously also for the decrease in the
proportion of supraglottic tumours.
PMID- 10687947
TI - Fibroblast growth factor-2.
AB - Fibroblast growth factor-2 (FGF-2) is a member of a large family of proteins that
bind heparin and heparan sulfate and modulate the function of a wide range of
cell types. FGF-2 stimulates the growth and development of new blood vessels
(angiogenesis) that contribute to the pathogenesis of several diseases (i.e.
cancer, atherosclerosis), normal wound healing and tissue development. FGF-2
contains a number of basic residues (pI 9.6) and consists of 12 anti-parallel
beta-sheets organized into a trigonal pyrimidal structure. FGF-2 binds to four
cell surface receptors expressed as a number of splice variants. Many of the
biological activities of FGF-2 have been found to depend on its receptor's
intrinsic tyrosine kinase activity and second messengers such as the mitogen
activated protein kinases. However, considerable evidence suggest that
intracellular FGF-2 might have a direct biological role particularly within the
nucleus. In addition, heparan sulfate proteoglycans have been demonstrated to
enhance and inhibit FGF-2 activity. The possibility that FGF-2 activity can be
manipulated through alterations in heparan sulfate-binding is currently being
exploited in the development of clinical applications aimed at modulating either
endogenous or administered FGF-2 activity.
PMID- 10687948
TI - Caspase-9.
AB - Caspase-9 is a member of caspase family of cysteine proteases that have been
implicated in apoptosis and cytokine processing. When cells receive apoptotic
stimuli, mitochondria releases cytochrome c which then binds to Apaf-1, the
mammalian Ced-4 homologue, together with dATP. The resultant complex recruits
Caspase-9 leading to its activation. Activated Caspase-9 cleaves downstream
caspases such as Caspase-3, -6 and -7 initiating the caspase cascade. The
majority of homozygous Caspase-9 null mice die perinatally with a markedly
enlarged and malformed cerebrum caused by a reduction of apoptosis during early
brain development. Thus, Caspase-9 function is essential for apoptosis during
normal development of the central nervous system. These data suggest that
inhibition of Caspase-9 activity would render opportunity to treat patients
suffering from neurological diseases such as stroke, neurodegenerative diseases
or brain injury caused by hypoxia.
PMID- 10687949
TI - Bikunin--not just a plasma proteinase inhibitor.
AB - Bikunin is a plasma proteinase inhibitor that has received little attention in
the past, probably because its activity towards various proteinases was found to
be relatively weak in early work. It was recently discovered, however, that
bikunin effectively inhibits a proteinase that seems to be involved in the
metastasis of tumour cells--cell surface plasmin--and that a fragment of bikunin
inhibits two proteinases of the coagulation pathway--factor Xa and kallikrein.
Furthermore, it has been found that bikunin has other properties, such as the
ability to modulate cell growth and to block cellular calcium uptake. Most of the
bikunin in the blood occurs as a covalently linked subunit of the proteins pre-
and inter-alpha-inhibitor. In this form bikunin lacks some of its known
activities, and there is evidence that its release by partial proteolytic
degradation may function as a regulatory mechanism. Although the physiological
function of bikunin still remains to be established, current data suggest that
this protein plays a role in inflammation. Further studies could therefore lead
to results of therapeutical value.
PMID- 10687950
TI - The quest to deduce protein function from sequence: the role of pattern
databases.
AB - In the wake of the numerous now-fruitful genome projects, we have witnessed a
'tsunami' of sequence data and with it the birth of the field of bioinformatics.
Bioinformatics involves the application of information technology to the
management and analysis of biological data. For many of us, this means that
databases and their search tools have become an essential part of the research
environment. However, the rate of sequence generation and the haphazard
proliferation of databases have made it difficult to keep pace with developments,
even for the cognoscenti. Moreover, increasing amounts of sequence information do
not necessarily equate with an increase in knowledge, and in the panic to
automate the route from raw data to biological insight, we may be generating and
propagating innumerable errors in our precious databases. In the genome era upon
us, researchers want rapid, easy-to-use, reliable tools for functional
characterisation of newly determined sequences. For the pharmaceutical industry
in particular, the Pandora's box of bioinformatics harbours an information-rich
nugget, ripe with potential drug targets and possible new avenues for the
development of therapeutic agents. This review outlines the current status of the
major pattern databases now used routinely in the analysis of protein sequences.
The review is divided into three main sections. In the first, commonly used terms
are defined and the methods behind the databases are briefly described; in the
second, the structure and content of the principal pattern databases are
discussed; and in the final part, several alignment databases, which are
frequently confused with pattern databases, are mentioned. For the new-comer, the
array of resources, the range of methods behind them and the different tools
required to search them can be confusing. The review therefore also briefly
mentions a current international endeavour to integrate the diverse databases,
which effort should facilitate sequence analysis in the future. This is
particularly important for target-discovery programmes, where the challenge is to
rationalise the enormous numbers of potential targets generated by sequence
database searches. This problem may be addressed, at least in part, by reducing
search outputs to the more focused and manageable subsets suggested by searches
of integrated groups of family-specific pattern databases.
PMID- 10687951
TI - Role of reactive oxygen species in apoptosis: implications for cancer therapy.
AB - Reactive oxygen species are widely generated in biological systems. Consequently
humans have evolved antioxidant defence systems that limit their production.
Intracellular production of active oxygen species such as *OH, O2- and H2O2 is
associated with the arrest of cell proliferation. Similarly, generation of
oxidative stress in response to various external stimuli has been implicated in
the activation of transcription factors and to the triggering of apoptosis. Here
we review how free radicals induce DNA sequence changes in the form of mutations.
deletions, gene amplification and rearrangements. These alterations may result in
the initiation of apoptosis signalling leading to cell death, or to the
activation of several proto-oncogenes and or the inactivation of some tumour
suppressor genes. The regulation of gene expression by means of oxidants,
antioxidants and the redox state remains as a promising therapeutic approach.
Several anticarcinogenic agents have been shown to inhibit reactive oxygen
species production and oxidative DNA damage, inhibiting tumour promotion. In
addition, recombinant vectors expressing radical-scavenging enzymes reduce
apoptosis. In conclusion, oxidative stress has been implicated in both apoptosis
and the pathogenesis of cancer providing contrived support for two notions: free
radical reactions may be increased in malignant cells and oxidant scavenging
systems may be useful in cancer therapy.
PMID- 10687952
TI - Bi-directional signal transduction by integrin receptors.
AB - The integrin family of cell surface glycoproteins functions primarily as
receptors for extracellular matrix ligands. There are now many well characterized
integrin-ligand interactions which are known to influence many aspects of cell
behaviour including cell morphology, cell adhesion, cell migration as well as
cellular proliferation and differentiation. However, in fulfilling these
functions, integrins are not simple adhesion receptors that physically mediate
connections across the plasma membrane. Rather, integrin function itself is
highly regulated, largely through the formation of specific associations with
both structural and regulatory components within cells. It is these intracellular
interactions which allow integrin function to effect many biochemical signalling
pathways and therefore to impinge upon complex cellular activities. Recently,
much research has focused on elucidating the molecular mechanisms which control
integrin function and the molecular processes which transduce integrin-mediated
signalling events. In this review, we discuss progress in the field of integrin
signal transduction including, where applicable, potential therapeutic
applications arising from the research.
PMID- 10687953
TI - Binding of 125I-insulin-like growth factor-II to cells cultured in fetal bovine
serum: a complication.
AB - Insulin-like growth factor II is an important fetal mitogen in mice and humans
and its biological activity is regulated in a complex manner. The peptide
interacts with three membrane-bound receptors, with a superfamily of insulin-like
growth factor binding proteins and with the proteoglycan, glypican-3. Recently,
the blood protein, vitronectin, has been identified as a novel insulin-like
growth factor II-binding protein. Many studies have used cell lines maintained in
fetal bovine serum to identify cell surface insulin-like growth factor II binding
sites. We now describe a complication associated with the interpretation of such
in vitro studies. Fetal bovine serum-derived vitronectin adheres very tightly to
tissue culture dishes. When cells that have been maintained in fetal bovine serum
are incubated with 125I-insulin-like growth factor II, a substantial fraction of
the 125I-insulin-like growth factor II apparently associated with the cell
surfaces may represent radioliogand bound by the fetal bovine serum-derived
vitronectin. This may result in over-estimation of cell surface insulin-like
growth factor II binding sites.
PMID- 10687954
TI - Characterisation of fibrillin-1 cDNA clones in a human fibroblast cell line that
assembles microfibrils.
AB - Fibrillin-1 is a large extracellular glycoprotein which is a major structural
component of 10-12 nm microfibrils. Defects in human fibrillin-1 give rise to the
autosomal dominant connective tissue disease the Marfan syndrome and related
disorders. Previous studies examining the biosynthesis and secretion of
recombinant fibrillin-1 fragments have been performed in cell lines which do not
assemble fibrillin into extracellular 10-12 nm microfibrils. Conflicting data
have been obtained regarding N-terminal processing. In this study we have
characterised a human fibroblast cell line MSU-1.1 which shows a similar
endogenous fibrillin-1 pulse chase profile to primary human dermal fibroblasts
and produces microfibrils. Expression of a approximately 50 kDa N-terminal
recombinant peptide in MSU-1.1 resulted in efficient secretion of this peptide
into conditioned media, N-terminal sequence analysis of the purified peptide
identified 2 protease cleavage sites and a presumed signal peptidase site.
Together these data identify the natural leader sequence of fibrillin-1 and the
presence of two processing sites in the N-terminus of fibrillin-1. The
identification of an N-terminal processing site in recombinant fibrillin-1
similar to that obtained in a previous study which used an HT1080 fibrosarcoma
host cell line excludes defective N-terminal processing as the cause of the
assembly defect in this cell line. A full length normal and mutant fibrillin cDNA
(approximately 8.6 kb) was constructed and stable integration of each into MSU1.1
led to RNA transcription at approximately 5% of endogenous levels. This is the
first report of transcription from the full length fibrillin-1 cDNA. The low
levels of transcription achieved, suggest that additional upstream and downstream
DNA sequence elements will be required for high levels of full length fibrillin-1
cDNA expression.
PMID- 10687955
TI - The overexpression of the CDC25 gene of Saccharomyces cerevisiae causes a
derepression of GAL system and an increase of GAL4 transcription.
AB - The CDC25 gene product is an exchange factor for Ras proteins and it activates
the Ras/cAMP pathway in the yeast Saccharomyces cerevisiae. The overexpression of
the CDC25 gene in S. cerevisiae cells causes a partial glucose-derepressed
phenotype which is particularly evident for expression of invertase. To define
domains of Cdc25 protein relevant for this derepression and to test another
glucose repressed system, different to invertase, we have overexpressed different
regions of the CDC25 gene under the control of a GAL-promoter. We found that a
derepression of both GAL regulated promoters and invertase was related to the
overexpression of CDC25 regions that contain a functional guanine nucleotide
exchange (GEF) domain. The effect on GAL-promoters was particular evident when
the CDC25 gene was under the control of a UASgal element and operates at
transcriptional level, although a moderate derepression was found also for
UASgal/lacZ reporter gene. Finally, the overexpression of the GEF domain of CDC25
also caused an increase in the expression of the GAL4 regulatory gene, while a
constitutive activation of the Ras/cAMP pathway did not produce any increase in
GAL4 expression. These findings indicate that the overexpression of the catalytic
domain of CDC25 gene is necessary and sufficient to give a glucose-derepression
of GAL promoters and of invertase. They also suggest that the derepression of GAL
promoters occurs through an increase of GAL4 expression in a Ras cAMP independent
way.
PMID- 10687956
TI - The plasma membrane of Xenopus laevis oocytes contains voltage-dependent anion
selective porin channels.
AB - Recent patch-clamp studies have shown that anti-porin antibodies, applied to the
external side of excised plasma membrane patches of mammalian astrocytes, close
chloride channels that are thought to be engaged in cell volume regulation. Frog
oocytes are often used to study this basic cell function. Here we document the
localisation of endogenous porin voltage-dependent anion-selective channels in
Xenopus laevis oocyte plasma membranes. In confocal laser microscopy images a
disjunctive pattern of fluorescing spots appear about 10 microm apart. Labelling
was prevented by preabsorption of the antibodies with synthetic peptides
comprising the epitope of the antigen. Immuno-gold marking of oocyte surfaces
followed by silver enhancement of the gold particles lead to a plasma membrane
labelling corresponding to that obtained by the confocal laser approach. The data
suggests the presence of voltage-dependent, anion-selective channels in oocyte
plasma membranes. This data should be borne in mind when frog oocytes are used to
study the characteristics of endogenous or heterologously expressed ion channels
or regulatory proteins.
PMID- 10687957
TI - Ribonuclease, cell-free translation-inhibitory and superoxide radical scavenging
activities of the iron-binding protein lactoferrin from bovine milk.
AB - The purpose of this study was to characterize the ribonuclease (RNase) and cell
free translation-inhibitory activities of lactoferrin isolated from bovine milk.
It was found that bovine lactoferrin exhibited ribonucleolytic activity toward
yeast transfer RNA in a dose-dependent manner. The pH optimum for this RNase
activity was in the vicinity of 7.5. Lactoferrin exerted RNase activity on poly C
with an activity of 2.15 U/mg. No activity was detected toward poly A, poly G,
and poly U. The milk protein inhibited cell-free translation in rabbit
reticulocyte lysate with an IC50 of 9.6 microM. The protein was devoid of N
glycosidase activity characteristic of ribosome inactivating proteins which also
possess RNase and cell-free translation-inhibitory activities. It inhibited
superoxide radical formation.
PMID- 10687958
TI - Detection of a mammalian histone H4 kinase that has yeast histidine kinase-like
enzymic activity.
AB - A well characterized histidine kinase purified from yeast has been shown to
phosphorylate histone H4 on a histidine residue. This enzyme is unlike the two
component histidine kinases predominantly found in prokaryotes. Until now, a
histidine kinase similar to this yeast enzyme has not been purified from a
mammalian source. By using a purification scheme similar to that used to purify
the yeast histidine kinase, a protein fraction with histone H4 kinase activity
has been isolated from porcine thymus. The yeast histidine kinase was shown to be
detectable using an in-gel kinase assay system and using this system, four major
bands of histone H4 kinase activity were apparent in the porcine thymus
preparation. Through the use of immunoprecipitation, alkaline hydrolysis and
subsequent phosphoamino acid analysis it has been demonstrated that this
partially purified kinase fraction is capable of phosphorylating histone H4 on
histidine. In conclusion, an preparation has been made from porcine thymus that
contains histone H4 kinase activity and at least one of the kinases present in
this preparation is a histidine kinase.
PMID- 10687959
TI - Presence of uterine peroxidase activity in the rat early pregnancy.
AB - Peroxidase has been associated with estrogen action in the uterus. This enzyme
plays an important role in the control of hydrogen peroxide levels and in
catechol estrogen production. Since the uterus, during early pregnancy, is
subjected to estrogen and progesterone regulation, we analyzed the changes of
peroxidase activity in relation to receptivity and uterine early response to the
embryo. Soluble and microsomal peroxidase activity were determined in the rat
uterus during the estrus phase and early pregnancy (days 3 through 6). Soluble
peroxidase activity increased significantly (p < 0.01) from day 3 (1.50 +/- 0.24)
to day 4 (3.5 +/- 0.3) and 5 (5 +/- 0.5 U/mg protein, mean +/- S.D., n = 6) of
pregnancy. During day 6, a significant decrease was noted in both the
implantation site and the nonimplantation uterine tissue. Microsomal calcium
extractable peroxidase showed a similar pattern, with lower specific activity
than, the soluble peroxidase. During estrus, the uterine tissue showed the
highest activity of calcium-extracted peroxidase (8.7 +/- 1.35 U/mg protein),
statistically greater when compared with days 3, 4, 5 and 6 of pregnancy. In
conclusion, high peroxidase activity was associated with uterine receptivity. The
decrease of activity on day 6 might be due to a progesterone-estrogen
interaction, and consequently, hydrogen peroxide can be utilized for hydroxile
production by means of the Fenton reaction. Lipoperoxidation may be necessary for
changes in membrane fluidity for embryo attachment to endometrial epithelium.
PMID- 10687960
TI - Barometers and bladders: a primer on pressures.
AB - PURPOSE: We develop a "consilient" (unified) view of pressure as a physical
phenomenon and "clinimetric" tool, making a connection between barometers and
bladders. MATERIALS AND METHODS: The philosophy, physics and clinical
applications of pressure during the last 2 millennia were examined from Lucretius
to the modern medical subspecialties. RESULTS: A variety of units and systems of
pressure quantification developed as the physics of pressure became understood.
Applications of pressure in clinical medicine with distinct physiological
relevance have been created for organ systems across the subspecialties. Some
measurements have become useful for management of urinary tract and other
diseases. CONCLUSIONS: Despite a broad range of units, systems and applications,
a consilient view of pressure in medicine can be approached. This perspective is
fundamental to understanding the significance of pressures in the expanding
clinimetric arena and should mitigate against misplaced concreteness that is
tempting in modern medical practice, whereby laboratory tests become virtual
realities and are mistaken for patients.
PMID- 10687961
TI - Andropause: a misnomer for a true clinical entity.
AB - PURPOSE: A progressive decrease in androgen production is common in males after
middle age. The resulting clinical picture has been erroneously named male
menopause or andropause. A more appropriate designation is androgen decline in
the aging male (ADAM). The syndrome is characterized by alterations in the
physical and intellectual domains that correlate with and can be corrected by
manipulation of the androgen milieu. We review the epidemiological aspects of
aging and endocrinological manifestations of ADAM, and provide recommendations
for treatment and monitoring of these patients. MATERIALS AND METHODS: We
performed MEDLINE, Pubmed, Current Contents and Pharmaceutical Abstracts searches
of relevant peer reviewed publications on andropause, male climacteric, adult
hypogonadism and aging. In addition, conference proceedings were researched to
provide a more complete review of the literature. Information was scrutinized and
collated, and contributory data were reviewed and summarized. RESULTS: ADAM is a
clinical entity characterized biochemically by a decrease not only in serum
androgen, but also in other hormones, such as growth hormone, melatonin and
dehydroepiandrosterone. Clinical manifestations include fatigue, depression,
decreased libido, erectile dysfunction, and alterations in mood and cognition.
CONCLUSIONS: The onset of ADAM is unpredictable and its manifestations are subtle
and variable, which has led to a paucity of interest in its diagnosis and
treatment. Urological practice commonly includes a large proportion of men older
than 50 years. Therefore, it is important for urologists to recognize the
manifestations of and be familiar with evaluations necessary to document ADAM as
well as its treatment and monitoring.
PMID- 10687962
TI - The lion of the union: the pelvic wound of Joshua Lawrence Chamberlain.
AB - PURPOSE: Major General Joshua Lawrence Chamberlain is a true American hero. His
medical history and war wounds provide a rare snapshot of Civil War era medicine.
In particular the most devastating injury was a rifle shot through the pelvis
rupturing the bladder and urethra. We describe this injury and how it affected
his life to provide insight into late 19th century urological care. MATERIALS AND
METHODS: All available references, including biographies, letters, surgical
reports, military documents and prior medical summaries, were reviewed regarding
Chamberlain's urological history. RESULTS: While leading the Union charge to
Petersburg, Virginia on June 18, 1864, Chamberlain was struck with a minie ball
anteriorly below the right greater trochanter. The ball coursed obliquely upward
disrupting the bladder and urethra, and embedded behind the left acetabulum. An
unprecedented wound exploration in the field hospital was performed to extract
the bullet and "reconnect severed urinary organs." Hope for recovery was
nonexistent as urine was seen exiting the lower wound postoperatively. This
genitourinary injury required 4 subsequent repairs during Chamberlain's lifetime
and ultimately left him with a draining urethrocutaneous fistula at the
penoscrotal junction. CONCLUSIONS: Survival from catastrophic Civil War wounds
was rare, especially from "gut wounds" which had a mortality rate of greater than
90%. Chamberlain not only survived but thrived with his sense of duty carrying
him back to the battlefield and beyond. He was plagued during his life with
recurrent cystitis and epididymo-orchitis, which in an era without antibiotics
was especially miserable. Urosepsis is listed as the cause of death on his death
certificate and whether this was true is debatable. However, even if this wound
did not cause his death, it surely contributed to it.
PMID- 10687963
TI - Outpatient adrenalectomy.
AB - PURPOSE: To our knowledge we report the initial experience with outpatient, same
day laparoscopic adrenalectomy. MATERIALS AND METHODS: Nine select patients were
entered into our ambulatory adrenalectomy protocol. Each patient fulfilled
certain preoperative and postoperative inclusion criteria, including informed
consent, age 70 years or older, body mass index 40 or less, adrenal tumor less
than 5 cm., no pheochromocytoma, uncomplicated laparoscopic surgery that was
completed by 12 p.m., perioperative hemodynamic stability and pain control by
oral analgesics. RESULTS: All 9 patients successfully underwent outpatient
laparoscopic adrenalectomy. Average patient age was 53 years and average adrenal
tumor size was 2 cm. Mean surgical time was 2.3 hours and mean blood loss was 53
ml. The diagnosis was aldosteroma in 7 cases, enlarging adenoma in 1 and
myelolipoma in 1. Average postoperative hospital stay was 416 minutes (range 300
to 570). Postoperative analgesia comprised 6 mg. morphine sulfate and 32 mg.
ketorolac. The only complication was a local abscess requiring delayed drainage
at 2 weeks. No other patient was rehospitalized for any reason. A followup
questionnaire survey revealed excellent patient satisfaction. CONCLUSIONS: To our
knowledge we report the initial series of outpatient laparoscopic excision of a
solid organ, the adrenal gland. Ambulatory adrenalectomy is feasible and safe,
and results in high patient satisfaction. However, ambulatory adrenalectomy
should be restricted to highly select patients and performed by minimally
invasive surgeons who have considerable experience with laparoscopic adrenal
surgery.
PMID- 10687964
TI - Variation in clinical outcome following shock wave lithotripsy.
AB - PURPOSE: We measure and compare operator specific success rates of extracorporeal
shock wave lithotripsy (ESWL) performed by 12 urologists in 1 unit to determine
interoperator variation. MATERIALS AND METHODS: From January 1, 1994 to September
1, 1997 a total of 5,769 renal and ureteral stones received 9,607 ESWL treatments
by 15 urologists with a Dornier MFL 5000 lithotriptor. The 3-month followup data
are available for 4,409 stones. Outcome measures consisted of patient
demographics, stone characteristics, technical details of lithotripsy, and stone
free and success rates by treating urologists. RESULTS: Treatment results were
analyzed for 12 urologists (surgeons A to L) who treated more than 100 stones
each, totaling 4,244 with followup information available. Mean stone-free and
success rates were 50.6% and 72.3%, respectively. Surgeon A had significantly
higher stone-free and success rates of 56.2% and 76.7%, respectively (p<0.05),
with treatment results from 877 stones, which was a significantly higher number
than others (p<0.05). Significant differences existed in mean number of shocks
delivered among urologists (p = 0.0001), with surgeons A and J delivering the
highest mean numbers (2,317 and 2,801, respectively). There was no difference in
treatment duration (p = 0.75) but variation existed among urologists in terms of
mean maximum treatment voltage (p = 0.0001). Mean fluoroscopy time at 4.1 minutes
was higher for surgeon A than others (p<0.05). Mean complication rate following
ESWL was 4.9% with no difference among urologists (p = 0.175). Re-treatment was
required in 21.7% of cases and surgeon A had the lowest rate (15.9%, p<0.05).
CONCLUSIONS: We demonstrated clinically and statistically significant intra
institutional differences in success rates following ESWL. The best results were
obtained by the urologist who treated the greatest number of patients, used a
high number of shocks and had the longest fluoroscopy time. Accurate targeting is
crucial when using a lithotriptor, such as the Dornier MFL 5000, with a narrow
focal zone of 6.5 mm. in diameter. Other centers should be encouraged to develop
similar programs of outcome analysis in an attempt to improve performance.
PMID- 10687965
TI - Nephrolithiasis associated with autosomal dominant polycystic kidney disease:
contemporary urological management.
AB - PURPOSE: We evaluate the role of contemporary urological intervention in patients
with nephrolithiasis associated with autosomal dominant polycystic kidney
disease. MATERIALS AND METHODS: Intervention for upper tract stones associated
with autosomal dominant polycystic kidney disease was performed in 5 women and 2
men 29 to 65 years old (mean age 47). Indications for intervention consisted of
flank pain in 6 patients and/or hematuria in 2. A total of 12 procedures (mean
1.7 per patient) were performed, including shock wave lithotripsy in 6 patients,
percutaneous nephrolithotomy in 2, retrograde endoscopy or manipulation in 3 and
extended pyelonephrolithotomy in 1. RESULTS: All patients were rendered stone
free or had only residual "dust." Hospital stay for 5 patients was 1 night or
less and there were no complications. Renal function for each patient was stable
or improved as measured by serum creatinine. CONCLUSIONS: Most patients with
autosomal dominant polycystic kidney disease who require intervention for
nephrolithiasis can be safely and effectively treated with essentially any or all
contemporary, minimally invasive techniques. The choice of intervention can be
based primarily on size and location of the upper tract stones rather than the
associated presence of polycystic kidneys.
PMID- 10687966
TI - Surgical management of renal tumors 4 cm. or less in a contemporary cohort.
AB - PURPOSE: We evaluated a patient cohort with renal tumors 4 cm. or less treated
with partial or radical nephrectomy. We compared patient and tumor
characteristics, and survival in these 2 groups. MATERIALS AND METHODS: We
retrospectively analyzed the records of 670 patients with a median age of 63
years treated surgically for renal cell carcinoma between July 31, 1989 and July
31, 1997. Renal tumors 4.0 cm. or less were noted in 252 patients (38%) who
underwent a total of 262 procedures, including 183 radical (70%) and 79 partial
(30%) nephrectomies. Ten patients required 2 operations each because of bilateral
renal cell carcinoma. Median followup was 40 months. We compared
clinicopathological parameters in the partial and radical nephrectomy groups
using chi-square or Wilcoxon analysis as appropriate. Survival analysis was
determined by the log rank test and Cox regression model. RESULTS: The partial
and radical nephrectomy groups were comparable with respect to gender ratio,
tumor presentation, histological classification, pathological stage and
complication rate. Median tumor size was 2.5 and 3.0 cm. in the partial and
radical nephrectomy groups, respectively (p = 0.0001). Resection was incomplete
in 1 patient (1.3%) in the partial and none in the radical nephrectomy group.
There was no local recurrence after either procedure, and no significant
difference in disease specific, disease-free and overall survival (p = 0.98, 0.23
and 0.20, respectively). CONCLUSIONS: Patients with a small renal tumor have
similar perioperative morbidity, pathological stage and outcome regardless of
treatment with partial or radical nephrectomy. Therefore, partial nephrectomy
remains a safe alternative for tumors of this size.
PMID- 10687967
TI - Nephron sparing surgery for central renal tumors: experience with 33 cases.
AB - PURPOSE: Nephron sparing surgery is standard treatment for small, peripherally
located renal cell carcinoma. In patients with a solitary kidney, bilateral
tumors or impaired renal function nephron sparing surgery provides the only
option to nephrectomy and subsequent hemodialysis or transplantation. We
retrospectively investigated the value of nephron sparing surgery for centrally
located renal cell carcinoma. MATERIALS AND METHODS: Between 1969 and 1997, 311
renal tumor enucleations were performed at our institution. The tumor was
centrally located in 33 cases. The indication for enucleation was elective in 7
cases and imperative in 26, including bilateral tumor in 16 (metachronous in 9
and synchronous in 7), chronic renal failure in 4 and solitary kidney in 6. Four
patients had metastasis at enucleation. RESULTS: Convalescence was unremarkable
in 28 cases. Hemorrhage occurred in 1 patient, a urinary fistula in 2 and a local
abscess secondary to a urinary fistula in 1. One patient died postoperatively of
heart failure. Average serum creatinine was 1.25, 1.63 and 1.33 mg./dl.
preoperatively, at hospital discharge and at a mean followup of 33 months,
respectively. Hemodialysis was necessary transiently during convalescence in 1
patient and permanently starting 6 years after enucleation in another. Definitive
histology revealed oncocytoma in 4 cases and renal cell carcinoma in 29. Disease
was stages pT1 to pT3 in 9, 18 and 2 cases, and grades 1 to 3 in 6, 18 and 5,
respectively. Local recurrence developed in 2 patients. Mean followup was 5.2
years (range 0.3 to 16.7). At a mean followup of 6.2 years (range 0.7 to 16.7) 20
patients were free of disease. In addition to the patient who died
postoperatively, 9 died of renal cell carcinoma at a mean of 1.6 years (range 0.3
to 5.3) and 3 died of other causes at 5, 11 and 12 years postoperatively,
respectively. No patient who underwent elective enucleation died. CONCLUSIONS:
Nephron sparing surgery for centrally located kidney tumors is technically
feasible and associated with an acceptable complication rate. Local tumor control
is excellent, and the overall prognosis depends on contralateral disease and
metastasis. Benign tumors may be diagnosed and removed without loss of the
kidney. By avoiding hemodialysis quality of life is improved.
PMID- 10687968
TI - Management of superficial transitional cell carcinoma in the intramural ureter:
what to do?
AB - PURPOSE: We analyze the evolution of superficial transitional cell carcinoma in
the intramural distal ureter treated with transurethral resection. MATERIALS AND
METHODS: A total of 19 patients underwent transurethral resection of the
intramural distal ureter with a mean followup of 57 months. All cases were
diagnosed as superficial transitional cell carcinoma and all but 2 had a history
of bladder tumor. Upper urinary tract followup consisted of excretory urography
every 6 months and ureterorenoscopy in cases with a doubtful diagnosis or
positive cytology. RESULTS: Pathological examination revealed stage Ta disease in
42%, T1 in 31.5% and Tx in 26.3% of intramural tumors. Upper urinary tract
recurrence was noted in 8 patients (42.1%), including 5 (62.5%) with involvement
of the distal ureter. Nontumoral stenosis of the distal ureter in 3 cases was
treated endoscopically. An endoscopic procedure resolved 75% of recurrences. A
high surgical risk patient who did not undergo open surgery died of recurrence.
CONCLUSIONS: Superficial transitional cell carcinoma of the intramural ureter is
uncommon in the setting of multiple bladder tumors and recurrent bladder
carcinoma. There was a 42.1% rate of ipsilateral recurrence and endoscopic
treatment allowed us to preserve 89.5% of the involved renal units. Closer
followup of the urinary tract must be performed since these tumors have a higher
incidence of upper urinary tract recurrence.
PMID- 10687969
TI - Clinical and pathological characteristics of micropapillary transitional cell
carcinoma: a highly aggressive variant.
AB - PURPOSE: We present preliminary clinical, histochemical and molecular findings
for 5 patients with micropapillary transitional cell carcinoma of the bladder, a
rare histological variant not widely recognized in the urological literature.
MATERIALS AND METHODS: The 5 patients were prospectively identified. In 3 cases
immunohistochemical staining for expression of CD31, p53, E-cadherin, and alpha,
beta and gamma-catenin was performed on paraffin embedded tissue. Sequencing was
used to identify point mutations in exons 5 to 9 of p53, and exons 1 and 2 of H
ras. RESULTS: Of the patients 2 died within 1 year of presentation to our
institution with rapid local extension along the bladder serosal surface and
ureteral sheaths. Another patient had progression to invasive disease within 22
months. In the 3 cases with immunohistochemical staining p53 was negative,
despite positive staining of nonmicropapillary transitional cell carcinoma within
the same specimen. Stains for the angiotrophic marker CD31 were negative. In all
3 cases normal membrane associated alpha, beta and gamma-catenin expression was
present. Examination of p53 sequences revealed a single point mutation in exon 8
of 1 case. In 2 cases different mutations in exon 1 of H-ras were noted.
CONCLUSIONS: Micropapillary transitional cell carcinoma is a rare and highly
aggressive variant. Paradoxically, our study demonstrated no significant p53
abnormalities. The lacunar histological pattern did not appear to represent
invasion of vascular spaces. Rather, these tumors seemed to have the ability to
disrupt and replace the normal stromal matrix to achieve rapid nonendothelial
extension. Thus, micropapillary histology may predict a lesser likelihood of
surgical cure.
PMID- 10687970
TI - Comparison of molecular and conventional strategies for followup of superficial
bladder cancer using decision analysis.
AB - PURPOSE: Patients with superficial bladder cancer require long-term surveillance
for recurrence. We compared the cost of cystoscopy and cytology (standard care)
to that of urinary markers (modified care) for patients with a history of
superficial bladder cancer. MATERIALS AND METHODS: We constructed a decision
analysis model that compared the 2 strategies for a hypothetical followup
interval of 3 years. Probabilities required for the decision tree were based on a
cohort of 361 patients diagnosed with superficial bladder cancer from 1987 to
1997. Sensitivity analyses were used to determine whether test sensitivity and
specificity would affect cost thresholds. Costs for each strategy were then
applied to actual practice patterns. RESULTS: The cost of modified care ranged
from $158 to $228 for each followup visit when using a urinary marker with a
sensitivity and specificity of 95% and 77%, respectively. The cost of standard
care was $240 for each followup visit. Based on sensitivity analyses the
probability of disease recurrence and urinary marker accuracy were important
determinants of expected costs. Mean number of followup assessments for patients
followed more than 3 years was 4.3, 2.2 and 1.5 for years 1, 2 and 3,
respectively. Cumulative costs of modified care were lower than those of standard
care. CONCLUSIONS: Urinary marker testing for followup of patients with
superficial bladder cancer is less expensive than the standard method of
cystoscopy and urinary cytology based on our model. Future studies will be
required to consider other factors that could affect the cost advantage of
urinary markers, including indirect costs, the psychosocial impact of testing and
different surveillance frequencies.
PMID- 10687971
TI - The role of bcl-2, p53, and ki-67 index in predicting tumor recurrence for low
grade superficial transitional cell bladder carcinoma.
AB - PURPOSE: We assess the prognostic significance of bcl-2 expression, p53 mutation
and ki-67 index for low grade, superficial transitional cell bladder carcinoma.
MATERIALS AND METHODS: The medical records of 93 cases of primary, low grade (24
G1, 69 G2), superficial (70 pTa, 23 pT1) transitional cell carcinoma of the
bladder were reviewed. Association of bcl-2, p53 and ki-67 index immunoreactivity
with tumor grade and stage was examined. Prognostic significance of tumor grade,
pathological stage, bcl-2 expression, p53 mutation and ki-67 index in predicting
tumor recurrence was assessed. RESULTS: Of the tumors 60 (70%) had p53 mutation
and 9 (10.5%) expressed bcl-2. These 2 markers did not relate to tumor grade or
pathological stage. Median ki-67 index was 10.9% and positively correlated with
tumor grade. Recurrence was noted in 34.9% of patients with a median followup of
26 months (range 1 to 84). The ki-67 index was the only significant prognostic
indicator in univariate and multivariate analyses. This marker can further
distinguish grade 2 tumors with a favorable prognosis from those with an
unfavorable outcome. CONCLUSIONS: The ki-67 labeling index is an independent
predictor of tumor recurrence for patients with primary superficial, low grade
bladder cancers.
PMID- 10687972
TI - Efficacy and safety of valrubicin for the treatment of Bacillus Calmette-Guerin
refractory carcinoma in situ of the bladder. The Valrubicin Study Group.
AB - PURPOSE: We assess the efficacy and safety of intravesical valrubicin for the
treatment of carcinoma in situ in patients with failure or recurrence after
bacillus Calmette-Guerin (BCG) and who otherwise would have undergone cystectomy.
Total anthracycline recovery in urine samples obtained within 24 hours of
valrubicin administration was assessed in a subset of patients. MATERIALS AND
METHODS: A total of 90 patients with recurrent carcinoma in situ after failed
multiple prior courses of intravesical therapy, including at least 1 course of
BCG, participated in this open label, noncomparative study. Each patient received
6 weekly instillations of 800 mg. intravesical valrubicin. Disease evaluations
were made at baseline and 3-month intervals following treatment. Evaluations
included cystoscopy with biopsy and urine cytology. Toxicity was noted throughout
treatment and followup. No evidence of disease recurrence for 6 months or greater
was considered a complete response. RESULTS: Of 90 patients 19 (21%) had a
complete response, including 7 who remained disease-free at the last evaluation,
with a median followup of 30 months. Additionally, 14 patients who did not meet
the strict protocol definition of complete response had superficial Ta disease
only. Median time to failure and/or last followup for complete responders was
greater than 18 months. Recurrence has been noted in 79 patients to date,
including only 2 with clinically advanced disease (stage T2). Of these 79
patients 44 (56%, 4 responders and 40 nonresponders) underwent radical
cystectomy. Of the 41 patients with known pathological stage 6 (15%) had stage
pT3 or greater at cystectomy. Four patients died of bladder cancer during the
median followup of 30 months, none of whom was a complete responder or underwent
cystectomy following valrubicin. The main side effects of valrubicin therapy were
reversible local bladder symptoms. CONCLUSIONS: Valrubicin was effective and well
tolerated in patients with carcinoma in situ of the bladder refractory to BCG
therapy. Delaying cystectomy while attempting salvage therapy with valrubicin
does not pose an undue risk to most patients.
PMID- 10687973
TI - Effect of bladder management on urological complications in spinal cord injured
patients.
AB - PURPOSE: The optimal method of bladder management in spinal cord injured patients
remains controversial. We investigated the association of type of bladder
management with urological complications in these patients. MATERIALS AND
METHODS: We retrospectively reviewed the medical records, upper tract imaging and
video urodynamics of 316 posttraumatic spinal cord injured patients. Mean
followup plus or minus standard deviation since injury was 18.3+/-12.4 years.
Patients were categorized according to bladder management method, including
chronic urethral catheterization, clean intermittent catheterization, spontaneous
voiding and suprapubic catheterization in 114, 92, 74 and 36, respectively. No
significant differences in patient age at injury, followup interval, or level,
completeness or mechanism of injury were noted among bladder management method
groups. Infection, stone disease, urethral complications and radiographic
abnormalities were recorded. RESULTS: Of the 398 complications recorded 236
developed in 61 (53.5%) patients on chronic urethral catheterization, 57 in 25
(27.2%) on clean intermittent catheterization, 57 in 24 (32.4%) who voided
spontaneously and 48 in 16 (44.4%) on suprapubic catheterization. The
intermittent catheterization group had statistically significant lower
complication rates compared with the urethral catheterization group and no
significantly higher complication rates relative to all other management methods
for each type of complication studied. The percent of patients with complications
was greater in the chronic urethral catheterization group only 5 years after
injury, while the percent in all other management groups remained similar up to
15 years after injury. CONCLUSIONS: Clean intermittent catheterization is the
safest bladder management method for spinal cord injured patients in terms of
urological complications. Inappropriate selection of a bladder management method
not only adversely affects patient quality of life, but also has a significant
detrimental impact on the economic status of the health care system.
PMID- 10687974
TI - Removal of UroLume endoprosthesis: experience of the North American Study Group
for detrusor-sphincter dyssynergia application.
AB - PURPOSE: We present the experience of the North American UroLume Multicenter
Study Group with removal of the UroLume endoprosthesis. MATERIALS AND METHODS: A
total of 160 neurologically impaired patients were enrolled in the North American
UroLume Multicenter Study Group for detrusor external sphincter dyssynergia
application. Analysis was performed in 2 groups of patients in which the device
was removed during insertion and after implantation, respectively. RESULTS:
Device retrieval was required during insertion in 21 patients (13%) mainly due to
misplacement or migration in 17. Extraction was done with minimal complications
and in all but 2 cases subsequent UroLume implantation was successful. Of 158 men
with the device in place 31 (19.6%) required removal. In 34 procedures 44 devices
were removed, mainly due to migration. Time from implantation to removal ranged
from 4 days to 66 months (mean 22 months). The UroLume was removed en bloc in 20
cases and in parts or wire by wire in 19. The majority of patients had no or
minimal complications after extraction. Only 2 patients had serious temporary
complications, including bleeding and urethral injury, with no lasting
consequences. No malignancy developed as a result of UroLume insertion.
CONCLUSIONS: While there is a potential for urethral injury and bleeding, UroLume
endoprosthesis removal is largely a simple procedure with minimal complications
and consequences.
PMID- 10687975
TI - Nocturia in the adult: classification on the basis of largest voided volume and
nocturnal urine production.
AB - PURPOSE: We propose a criterion to clarify the underlying etiologies of nocturia.
MATERIALS AND METHODS: Frequency-volume charts were recorded for 24 hours by 35
men and 32 women who were subjectively free of lower urinary tract symptoms and
had no evidence of voiding disorders. At least 5 subjects were included in each
of 5 age groups of 20 to 49, 50 to 59, 60 to 69, 70 to 79, 80 to 89 years for
both genders. The charts were used to make a tentative criterion, which was
validated in 39 elderly individuals with nocturnal frequency. RESULTS:
Correlation and regression analyses indicated that the quotients of nocturnal
urine output divided by body weight (U(N)/BW) and largest voided volume divided
by body weight (V(L)/BW) were useful classification factors. Cutoffs, which were
set close to worst quartiles, were 10 ml./kg. for U(N)/BW and 4 ml./kg. for
V(L)/BW, respectively. Correction by body weight made the same criterion
applicable irrespective of weight. Symptomatic elderly patients were classified
into 3 mutually exclusive groups of nocturnal polyuria (U(N)/BW greater than 10
ml./kg.), low bladder capacity (V(L)/BW less than 4 ml./kg.) and combined
nocturia. Of 20 subjects who voided 2 times a night 11 (55%) were classified as
having nocturnal polyuria and 15 of 19 who voided 3 or 4 times (79%) were
classified as having low bladder capacity or combined nocturia. CONCLUSIONS: The
criterion provides a reasonable distinction of etiologies of nocturia, and may be
usefulness in examination and treatment.
PMID- 10687976
TI - Cowper's syringocele: symptoms, classification and treatment of an unappreciated
problem.
AB - PURPOSE: Cowper's syringocele is a rare deformity in the male urethra that is a
distention of the duct of the bulbourethral (Cowper's) gland. We report on 7
cases, review the symptoms and pathophysiology, and propose a simplified
classification of this uncommon lesion. MATERIALS AND METHODS: We reviewed 7
cases of Cowper's syringocele diagnosed from 1997 to 1998 at our hospital.
RESULTS: Cowper's syringocele was diagnosed in 7 patients 25 to 51 years old with
persistent post-void dribbling, frequency, urethral pain, hematuria or sudden
urethral discharge. Diagnosis was made with urethrocystoscopy or retrograde
urethrogram. Cowper's syringocele may be closed (a distended cyst-like swelling
in the wall of the urethra) or open (an opening enabling urine reflux into the
syringocele). In 2 patients asymptomatic open syringocele was diagnosed. In 1
patient symptomatic syringocele resolved spontaneously following an infection. In
4 patients open syringocele was treated with transurethral marsupialization
because of persistent post-void dribbling. Postoperatively patients were
completely symptom-free with a mean followup of 12 months (range 6 to 23).
CONCLUSIONS: Cowper's syringocele may be more common than currently realized.
Urologists should rule out this possibility in young male patients with lower
urinary tract symptoms and persistent post-void dribbling as it can be treated
easily.
PMID- 10687977
TI - Intraurethral application of alprostadil in patients with failed inflatable
penile prosthesis.
AB - PURPOSE: Many men who underwent penile prosthesis implantation before the advent
of oral and injection therapy present for replacement of a malfunctioning
prosthesis but choose not to undergo revision surgery because of personal,
medical or reimbursement issues. Others with normally functioning prostheses
report significant difficulties with "cold glans," and they and their partners
observe decreased engorgement and temperature of the glans penis with the
inflated penile prosthesis, despite adequate stimulation. Intracorporal injection
therapy is contraindicated in any patient with a penile prosthesis and use of a
vacuum erection device may result in prosthesis cylinder rupture. In these
patients intraurethral application of alprostadil may restore prosthesis function
and permit satisfactory intercourse. We evaluate the efficacy of a medicated
urethral system for erection (MUSE) using alprostadil to restore function for men
with a failed prosthesis, and improve glans penis temperature sensation and
engorgement for those with a functioning prosthesis. MATERIALS AND METHODS: From
February 1997 to February 1998, 28 men 47 to 81 years old (mean age 61.2) with a
penile prosthesis were treated with alprostadil. Of the patients 11 had penile
prosthesis failure (group 1) and 17 reported decreased glans penis engorgement
(group 2). In 18 cases erections were observed at the clinic. Doses of
alprostadil varied from 250 to 1,000 microgm. (mean 566). RESULTS: Of the 28
patients 23 had a response to alprostadil. Erections were sufficient for
intercourse in 7 of 11 group 1 patients, and 10 of 17 group 2 were satisfied with
treatment. There was no device specific morbidity but 12 men discontinued use of
alprostadil because of penile pain. A significant or excellent response was noted
in 10 of 18 men observed at the clinic. CONCLUSIONS: Intraurethral alprostadil
may be used to restore or improve function of a penile prosthesis in patients
with a malfunctioning device or lack of glans penis engorgement, with low
expected morbidity.
PMID- 10687978
TI - Sexual function in men with diabetes type 2: association with glycemic control.
AB - PURPOSE: We evaluated the association of glycemic control with erectile
dysfunction in men with diabetes type 2. MATERIALS AND METHODS: A convenience
sample of men with diabetes type 2 at the Cleveland Veterans Affairs Medical
Center completed questions 1 to 5 of the International Index of Erectile
Function. The primary outcome measure was erectile function score, calculated as
the sum of questions 1 to 5. Details of disease duration, complications,
medication use, patient age and level of glycosylated hemoglobin were obtained by
reviewing the medical record. RESULTS: Mean subject age plus or minus standard
deviation was 62.0+/-12.3 years, mean hemoglobin A1c was 8.1%+/-1.9% and mean
erectile function score was 16.6+/-5.9 (range 5 to 23). Stratified analysis
revealed that mean erectile function score decreased as hemoglobin A1c increased
(analysis of variance p = 0.002). The test for linearity was also significant (p
= 0.001). There were no statistically significant associations of levels of
glycemic control with alpha-blocker, beta-blocker or diuretic use. Bivariate
analysis showed a significant correlation of hemoglobin A1c with neuropathy but
not with patient age, duration of diabetes, alpha-blockers, beta-blockers or
diuretics. Multivariate analysis demonstrated that hemoglobin A1c was an
independent predictor of erectile function score (p<0.001) even after adjusting
for peripheral neuropathy, which was also an independent predictor (p = 0.023).
CONCLUSIONS: Our data add to the growing body of literature suggesting that
erectile dysfunction correlates with the level of glycemic control. Peripheral
neuropathy and hemoglobin A1c but not patient age were independent predictors of
erectile dysfunction.
PMID- 10687979
TI - Testis biopsy findings in the spinal cord injured patient.
AB - PURPOSE: Azoospermia after electroejaculation in spinal cord injured men may be
due to testicular failure or obstruction. These men can initiate pregnancy with
assisted reproductive techniques, such as intracytoplasmic sperm injection, but
only if sperm are present in the testis biopsy. We analyzed the histopathology of
testis biopsies from spinal cord injured men and assessed whether patient factors
were predictive of testis biopsy pathology. MATERIALS AND METHODS: A total of 50
paraplegic men undergoing testis biopsy were divided into 2 groups based on
normal or abnormal testis histopathology. Patient age, post-injury years, level
of lesion, hormonal status and semen analysis results were compared. RESULTS:
Spermatogenesis was normal in 28 of the 50 patients. Hypospermatogenesis was
exhibited in 15, maturation arrest at the spermatid stage in 6 and maturation
arrest at the spermatocyte stage in 1 of the 22 abnormal cases. Nevertheless,
mature sperm were identified in 43 of 50 biopsies (normal spermatogenesis and
hypospermatogenesis). Men with normal spermatogenesis had better forward
progression of sperm and a higher testosterone-to-luteinizing hormone ratio.
Otherwise, there was no statistically significant correlation between study
variables and testis biopsy results. No factors were predictive of testis biopsy
histopathology. CONCLUSIONS: The documentation of mature sperm in 43 of 50
biopsies from spinal cord injured patients suggests that a high rate of sperm
retrieval is possible using testicular sperm extraction if sperm cannot be
retrieved from the ejaculate. With intracytoplasmic sperm injection techniques
the majority of spinal cord injured men retain fertility potential, even if
azoospermic following electroejaculation.
PMID- 10687980
TI - Recognizing abnormal marker results that do not reflect disease in patients with
germ cell tumors.
AB - PURPOSE: The judicious use of serum alpha-fetoprotein (AFP), human chorionic
gonadotropin (HCG) and lactate dehydrogenase is key to appropriate management of
patients with germ cell tumors. Elevated AFP and/or HCG generally indicate active
disease. We describe patients with germ cell tumors who had elevated serum AFP
and/or HCG but no active disease, despite careful repeat evaluation. MATERIALS
AND METHODS: Histories of 6 cases of germ cell tumors that remained in remission
despite abnormal serum AFP and/or HCG were reviewed. RESULTS: Markers were only
modestly elevated, remained constant or spontaneously normalized during repeat
measurements, and there was no other clinical or radiographic evidence of
disease. Patients were treated conservatively with physical examination,
radiological tests and repeat marker assays, with no relapse to date.
CONCLUSIONS: Stable, low increases in serum AFP and HCG may not represent active
disease. Careful repeat evaluation will determine whether the markers increase.
If no change is noted after appropriate studies have been reviewed by an
experienced practitioner to exclude active disease from diagnosis, then
consideration should be given to managing such cases with close surveillance to
avoid unnecessary chemotherapy.
PMID- 10687981
TI - Dramatic suppression of plasma and urinary prostate specific antigen and human
glandular kallikrein by antiandrogens in male-to-female transsexuals.
AB - PURPOSE: Prostate specific antigen (PSA) and human glandular kallikrein (hK2) are
mainly produced by the prostate and their genes are regulated by androgens
through the androgen receptor. We determine whether PSA and hK2 change
significantly in plasma and urine after antiandrogen treatment in male-to-female
transsexuals. MATERIALS AND METHODS: Plasma and urine PSA and hK2 were measured
with highly sensitive immunofluorometric procedures capable of detecting within 1
or 6 ng./l. PSA or hK2, respectively. Study groups consisted of 10 men treated
with cyproterone acetate only (group 1), 15 transdermal estradiol plus
cyproterone acetate (group 2) and 31 ethinyl estradiol plus cyproterone acetate
(group 3). Plasma and urine samples were collected before initiation of treatment
as well as after 4 months of hormonal therapy. For a subset of group 3 patients
blood and urine samples were also obtained after 12 months of treatment. RESULTS:
Cyproterone acetate, a steroidal antiandrogen, alone or with estradiol was able
to suppress greater than 90% of plasma and urinary PSA and hK2 concentration
after 4 or 12 months of therapy. CONCLUSIONS: Cyproterone acetate therapy causes
dramatic suppression of plasma and urinary PSA and hK2 in men without prostate
cancer. Since cyproterone acetate is used for prostate cancer treatment,
suppression of PSA after hormonal therapy may not accurately reflect therapy
success in reducing tumor burden.
PMID- 10687982
TI - Prostate cancer detection at low prostate specific antigen.
AB - PURPOSE: At low prostate specific antigen (PSA) the indication for prostate
biopsy is usually an abnormal digital rectal examination. We evaluate the
diagnostic value of PSA, digital rectal examination, transrectal ultrasonography
and tumor characteristics at low PSA (0 to 4.0 ng./ml.). We confirm and add to
recent evidence that digital rectal examination has a low predictive value and
that many significant cancers at this PSA range may be missed. MATERIALS AND
METHODS: From 1994 to 1997 a total of 10,523 participants 54 to 74 years old were
randomized to screening in the Rotterdam section of the European Randomized Study
of Screening for Prostate Cancer. Of the participants 9,211 (87.5%) had PSA less
than 4.0 ng./ml., and underwent digital rectal examination and transrectal
ultrasonography. Expected rates of prostate cancer detection were calculated
using logistic regression analysis. Radical prostatectomy was performed in about
half of the 478 men diagnosed with prostate cancer. Tumors were characterized by
pT category, Gleason score and cancer volume in 166 processed radical
prostatectomy specimens. In 50 of these cases PSA was 0 to 4.0 ng./ml. RESULTS:
The positive predictive value of digital rectal examination and transrectal
ultrasonography at PSA 0 to 4.0 ng./ml. was only 9.7%. Positive predictive value
strongly depended on PSA. Sensitivity was calculated by using estimates of the
prevalence of sextant biopsy detectable prostate cancers. Of 760 detectable
cancers 478 (67%) were diagnosed irrespective of PSA in men screened with digital
rectal examination, transrectal ultrasonography and PSA. Only 127 of 348
detectable prostate cancers (36.5%) were actually diagnosed in men with PSA 2 to
4 mg./ml. The importance of these missed cancers was evaluated with parameters of
tumor aggressiveness within PSA ranges. CONCLUSIONS: Approximately half of the
tumors missed with PSA 0 to 4 ng./ml. had aggressive characteristics (Gleason
score 7 or greater, Gleason 4-5 components) and were organ confined. These tumors
should be diagnosed and treated according to the present understanding of their
natural history. More sensitive and selective screening strategies are needed.
Presently a wrong "window of opportunity" is used for early detection of prostate
cancer.
PMID- 10687983
TI - Predictors of first repeat biopsy cancer detection with suspected local stage
prostate cancer.
AB - PURPOSE: We determine demographic and tumor related predictors of repeat biopsy
cancer detection in men with suspected stage T1c-2 prostate cancer. MATERIALS AND
METHODS: The study population included 298 consecutive men with suspected stage
T1c-2 prostate cancer who had a benign prostate biopsy at 1 institution between
January 1, 1992 and April 1, 1999 and underwent 1 repeat biopsy. Mean age plus or
minus standard deviation was 66.8+/-6.7 years for 133 black (55%) and 165 white
(45%) patients. Clinical measures included determination of high grade prostatic
intraepithelial neoplasia in benign biopsy specimens, Gleason score of malignant
biopsy specimens, prostate specific antigen (PSA), PSA density, annualized
interbiopsy PSA change, percent free PSA (201 cases) and PSA velocity (171).
RESULTS: Cancer was detected on repeat biopsy in 80 cases (27%). Significant
differences between patients with benign and malignant repeat biopsies included
age (p = 0.001), PSA density (p = 0.0001), percent free PSA (p = 0.0001) and PSA
velocity (p = 0.009). High grade prostatic intraepithelial neoplasia in an
initial benign biopsy was not predictive of cancer in repeat biopsy (p = 0.12).
Multiple logistic regression analysis of all cases showed that age (p = 0.002)
and PSA density (p = 0.0002) were independent predictors of cancer. Subset
multiple logistic regression analysis modeled with age, PSA density and percent
free PSA demonstrated that age (p = 0.002) and percent free PSA (p = 0.0001) were
significant independent predictors of malignancy. Subset multiple logistic
regression analysis modeled with age, PSA density, percent free PSA and PSA
velocity revealed that age (p = 0.02) and percent free PSA (p = 0.0003) were
significant independent predictors of cancer. There were no significant
differences between the Gleason scores of cancers detected on repeat biopsy
compared to 587 stage T1c-2 cancers detected on initial biopsy during the study
period (p = 0.09). PSA, PSA density, percent free PSA and PSA velocity were not
significantly different among men without a cancer diagnosis who had high grade
neoplasia in 1 or 2 benign biopsies. CONCLUSIONS: Greater than 25% of this
population of select patients with suspected stage T1c-2 prostate cancer had
malignancy detected on repeat biopsy. Percent free PSA was the most powerful
predictor of cancer. High grade prostatic intraepithelial neoplasia was not a
predictor of repeat biopsy cancer detection and PSA functions were similar among
men without cancer who did and did not have high grade neoplasia in 1 or more
benign biopsies. This finding suggests that high grade prostatic intraepithelial
neoplasia may not be a reliable indicator of clinically significant existing
prostate cancer.
PMID- 10687984
TI - Strategy for repeat biopsy in patients with high grade prostatic intraepithelial
neoplasia.
AB - PURPOSE: The finding of high grade prostatic intraepithelial neoplasia in a
biopsy specimen without prostate cancer warrants repeat biopsy because of the
risk of concurrent cancer. However, to our knowledge the optimal repeat biopsy
technique has not yet been defined. We determined the optimal subsequent biopsy
strategy for detecting concurrent cancer in patients diagnosed with high grade
prostatic intraepithelial neoplasia. MATERIALS AND METHODS: Of 63 men with
isolated high grade prostatic intraepithelial neoplasia on initial biopsy 45
underwent repeat biopsy within 1 year. Certain biopsy patterns were used for
repeat biopsy, including only the neoplasia site in 8 men, sextant in 12, sextant
plus bilateral transition zone in 13 and 11 core multisite directed (sextant,
bilateral transition zone, bilateral anterior horn of the peripheral zone and
midline peripheral zone) in 12. We compared the location of high grade disease on
the initial biopsy with the cancer site on repeat biopsy. RESULTS: Repeat biopsy
revealed cancer in 10 of the 45 men (22%), and the sites of high grade prostatic
intraepithelial neoplasia and cancer correlated in 6. Cancer was detected at the
sextant locations in 9 men. Of the 15 cores positive for cancer 8 were at the
original high grade neoplasia site, 6 at a random sextant biopsy site and 1 in
the transition zone. High grade disease was discovered bilaterally in 1 man,
while prostatic intraepithelial neoplasia and cancer were detected on the same
side in the remaining 9. CONCLUSIONS: The optimal repeat biopsy strategy for
patients with high grade prostatic intraepithelial neoplasia has not yet been
determined but at a minimum it should include targeting the area of known high
grade disease and the ipsilateral sextants.
PMID- 10687985
TI - Is low serum free testosterone a marker for high grade prostate cancer?
AB - PURPOSE: The association of free and total testosterone with prostate cancer is
incompletely understood. We investigated the relationship of serum free and total
testosterone to the clinical and pathological characteristics of prostate cancer.
MATERIALS AND METHODS: We retrospectively reviewed the clinical records of 117
consecutive patients treated by 1 physician and diagnosed with prostate cancer at
our medical center between 1994 and 1997. Low free and total testosterone levels
were defined as 1.5 or less and 300 ng./dl., respectively. RESULTS: After
evaluating all 117 patients we noted no correlation of free and total
testosterone with prostate specific antigen, patient age, prostatic volume,
percent of positive biopsies, biopsy Gleason score or clinical stage. However, in
patients with low versus normal free testosterone there were an increased mean
percent of biopsies that showed cancer (43% versus 22%, p = 0.013) and an
increased incidence of a biopsy Gleason score of 8 or greater (7 of 64 versus 0
of 48, p = 0.025). Of the 117 patients 57 underwent radical retropubic
prostatectomy. In those with low versus normal free testosterone an increased
mean percent of biopsies demonstrated cancer (47% versus 28%, p = 0.018).
Pathological evaluation revealed stage pT2ab, pT2c, pT3 and pT4 disease,
respectively, in 31%, 64%, 8% and 0% of patients with low and in 40%, 40.6%,
12.5% and 6.2% in those with normal free testosterone (p>0.05). CONCLUSIONS: In
our study patients with prostate cancer and low free testosterone had more
extensive disease. In addition, all men with a biopsy Gleason score of 8 or
greater had low serum free testosterone. This finding suggests that low serum
free testosterone may be a marker for more aggressive disease.
PMID- 10687986
TI - Beyond prostate specific antigen--markers for prostate cancer for the 21st
Century.
PMID- 10687987
TI - The role of preoperative epoetin alfa in men undergoing radical retropubic
prostatectomy.
AB - PURPOSE: The safety and effects on hematocrit of recombinant human erythropoietin
(epoetin alfa) were evaluated in men undergoing radical retropubic prostatectomy.
MATERIALS AND METHODS: Between February 1, 1997 and November 2, 1998, 305 men
with clinically localized adenocarcinoma of the prostate underwent radical
retropubic prostatectomy performed by a single surgeon (H. L.). Of these men 283
with a baseline hematocrit of less than 48% received 600 IU/kg. epoetin alfa 14
days (-14) and 7 days (-7) before radical retropubic prostatectomy. Hematocrit
was measured at baseline on day -14, on day -7, just before anesthesia induction
on day 0, immediately postoperatively and on the day of discharge home. The
number of allogeneic units transfused, and all intraoperative and postoperative
complications were recorded. RESULTS: Mean hematocrit at baseline on day -14 and
at induction on day 0 was 42.9% and 45.8%, respectively (p = 0.0001). The
frequency of hematocrit decreasing, showing no change or increasing 0.1 to 1.9,
2.0 to 3.9 or greater than 4.0 hematocrit points was 16.5%, 0.5%, 23%, 22% and
38%, respectively. Of the men 17% had no increase in hematocrit. A weak
correlation existed between baseline hematocrit and the erythropoietic response
to epoetin alfa (r2 = 0.06). Mean change in hematocrit after treatment with
epoetin alfa in the quartile baseline hematocrit groups 34.2 to 41.4, 41.5 to
43.2, 43.3 to 44.9 and 45.0 to 48.0 hematocrit points was 3.71, 2.45, 3.86 and
1.02 hematocrit points, respectively. Of the surgical candidates 22 (9.1%)
achieved an induction hematocrit of greater than 51%. Of the 283 men receiving
epoetin alfa 21 (7.4%) also received an allogeneic transfusion. The transfusion
rate did not correlate with induction hematocrit. The only adverse cardiovascular
event was an uncomplicated postoperative pulmonary embolus. CONCLUSIONS: Our
prospective study demonstrates that epoetin alfa given preoperatively in 2 doses
of 600 IU/kg. is safe for significantly increasing hematocrit in men before
radical retropubic prostatectomy. It is intuitive that the significant increase
in hematocrit decreases the requirement for allogeneic blood transfusion.
PMID- 10687988
TI - Dexamethasone does not significantly contribute to the response rate of docetaxel
and estramustine in androgen independent prostate cancer.
AB - PURPOSE: We evaluated the independent response rate of dexamethasone before
docetaxel and estramustine administration as measured by changes in serum
prostate specific antigen (PSA) in patients with androgen independent prostate
cancer. MATERIALS AND METHODS: A total of 12 patients received 20 mg.
dexamethasone orally every 6 hours for 3 doses repeated every 3 weeks before
starting cytotoxic therapy with estramustine and docetaxel. After progression on
dexamethasone 280 mg. estramustine orally 3 times daily on days 1 to 5 and 70
mg./m.2 docetaxel intravenously for 1 hour on day 2 were given. RESULTS: None of
the patients initially treated with dexamethasone monotherapy (median 1 cycle,
range 1 to 5) had a PSA decline of 50% or greater. Median PSA increase on
monotherapy was 47% (range 0% to 22%). On estramustine and docetaxel therapy PSA
decreased 50% or greater in 11 patients (92%, 95% confidence intervals [CI] 60 to
99) and 80% or greater in 7 (58%, 95% CI 29 to 84), and normalized in 5 (42%, 95%
CI 16 to 71), with a median duration of response of 153 (range 42 to 371), 132
(range 84 to 287) and 84 (range 21 to 174) days, respectively. Median times to
reach 50% and 80% decreases in baseline PSA were 21 (range 21 to 209) and 63
(range 21 to 138) days, respectively. In 9 patients (75%, 95% CI 43 to 93) PSA
decreased at least 50% by week 9. Of 4 patients with bidimensionally measurable
disease 3 had a partial response. Median time to progression was 263 days (range
91 to 378). CONCLUSIONS: Administration of 20. mg. dexamethasone orally every 6
hours for 3 doses every 3 weeks does not significantly contribute to the PSA
response rate of estramustine and docetaxel.
PMID- 10687989
TI - An implant releasing the gonadotropin hormone-releasing hormone agonist histrelin
maintains medical castration for up to 30 months in metastatic prostate cancer.
AB - PURPOSE: The administration of gonadotropin hormone-releasing hormone agonists is
well established for treating metastatic prostate cancer. In an ongoing study we
evaluated the effect of a long acting implant that releases the gonadotropin
hormone-releasing hormone agonist histrelin ([ImBzl]D-His6,Pro9-Net) in 15
patients with disseminated prostate cancer. MATERIALS AND METHODS: The 2.6 cm.
implant releasing 60 microg. histrelin daily is inserted subcutaneously into the
upper arm using local anesthesia. Of the patients 8 received 1 and the remainder
received 2 implants. Treatment with the antiandrogen flutamide or cyproterone
acetate began 2 weeks before implant insertion and continued for up to 12 weeks.
Testosterone, luteinizing hormone (LH) and prostate specific antigen were
determined monthly, and a metastatic evaluation was performed every 6 months.
RESULTS: LH and testosterone increased after flutamide administration and
decreased after implant insertion. By day 28 LH and testosterone were completely
suppressed. LH and testosterone decreased immediately after cyproterone acetate
administration. Prostate specific antigen began to decrease during antiandrogen
therapy and decreased further after implant insertion. One patient requested
implant removal after 1 year for personal reasons and 1 died of an unrelated
cause 18 months after insertion. Escape was demonstrated in 4 cases at 5, 10, 12
and 19 months, although LH and testosterone remained suppressed. Duration of
treatment in the remaining 9 patients was between 21 and 30 months. LH and
testosterone remained completely suppressed and prostate specific antigen levels
were in the normal range. The clinical and biochemical response was identical in
those who received 1 or 2 implants. At 12 months 8 patients were challenged at
intermittent intervals for up to 24 months with a bolus of 100 microg.
gonadotropin hormone-releasing hormone followed by 2 weeks of flutamide. The
response was compared with that in untreated controls recently diagnosed with
prostate cancer. Unlike controls there was complete LH suppression in the 8
challenged patients. CONCLUSIONS: A histrelin implant suppresses LH and
testosterone in prostate cancer for up to 30 months. This finding represents a
significant improvement over existing preparations, which must be administered at
1 to 3-month intervals.
PMID- 10687990
TI - Radiotherapy for isolated serum prostate specific antigen elevation after
prostatectomy for prostate cancer.
AB - PURPOSE: Elevated serum prostate specific antigen (PSA) may be the initial and
only indication of disease recurrence after prostatectomy for prostate cancer.
External beam radiotherapy may be given in this setting in an attempt to
eradicate the disease but therapeutic outcomes after this approach require
further description. We describe the intermediate term outcome in a large group
of patients treated with radiotherapy and identify pre-therapy factors associated
with disease outcome. MATERIALS AND METHODS: We retrospectively studied a cohort
of 166 consecutive patients treated with radiotherapy between July 1987 and May
1996. The Kaplan-Meier method was used to describe patient outcome for the
overall study group, and statistical associations of pre-therapy variables with
outcome were sought to identify predictive factors. RESULTS: At a median followup
of 52 months 46% (95% confidence interval 38 to 55) of patients were expected to
be free of biochemical relapse 5 years after radiotherapy. Multivariate analysis
identified pathological classification (seminal vesicle invasion), tumor grade
and preradiotherapy serum PSA as independent factors associated with biochemical
relapse. Although in 1 of 6 patients a chronic complication was attributed to
radiotherapy, it was often mild and self-limited in nature. CONCLUSIONS: In our
current series approximately half of the patients treated with radiotherapy for
an isolated elevation of serum PSA after prostatectomy were free of biochemical
relapse at 5 years of followup. Radiotherapy may be given in this setting with
modest long-term morbidity.
PMID- 10687991
TI - Quality of life outcomes after brachytherapy for early stage prostate cancer.
AB - PURPOSE: We compare general and disease specific health related quality of life
in men undergoing brachytherapy for early stage prostate cancer to those
undergoing radical prostatectomy and age matched healthy controls. MATERIALS AND
METHODS: Cohorts consisted of 48 men treated with brachytherapy with and without
pretreatment external beam radiation therapy (brachytherapy group), 74 who
underwent radical prostatectomy (prostatectomy group) and age matched healthy
controls from the literature. The RAND 36-item general health survey, University
of California Los Angeles Prostate Cancer Index, American Urological Association
symptom index, validated Cancer Interference with Life and Family Scales, and
sociodemographic and co-morbidity questionnaires were completed 3 to 17 months
after treatment. RESULTS: General health related quality of life did not differ
greatly among the 3 groups. Urinary function (leakage) was worse in the
brachytherapy group than in controls but better than in the prostatectomy group.
Brachytherapy group patients had more irritative urinary symptoms and worse bowel
function than controls. Sexual function and bother were worse in prostatectomy
and brachytherapy groups than in healthy controls. Physical function, bodily
pain, urinary function, and bother and American Urological Association symptom
index scores improved with time after brachytherapy. Patients who underwent
brachytherapy after external beam radiation performed worse in all general and
disease specific health related quality of life domains compared to those who did
not undergo pretreatment radiation therapy. CONCLUSIONS: At an average of 7.5
months after treatment the general health related quality of life of patients
undergoing brachytherapy with and without pretreatment external beam radiation
was similar to age matched controls, although urinary, bowel and sexual problems
were reported. These problems appeared to improve during the first year after
treatment. Much of the impairment in disease specific health related quality of
life among patients undergoing brachytherapy may be attributed to pretreatment
radiation.
PMID- 10687993
TI - Experience with early catheter removal after radical retropubic prostatectomy.
AB - PURPOSE: We tested the hypothesis that early catheter removal may be accomplished
safely after radical prostatectomy. MATERIALS AND METHODS: Cystography on
postoperative day 4 or 5 in 42 of 67 consecutive patients who underwent radical
retropubic prostatectomy revealed no extravasation in 30 and the urethral
catheter was removed (group 1). The control group included 25 patients who did
not undergo cystography, and the catheter was removed 14 days postoperatively
(group 2). RESULTS: Immediate and late continence was achieved in 14 (46.7%) and
25 (83.3%) cases in group 1, and in 8 (32%) and 22 (88%) cases in group 2,
respectively (p>0.05). Catheterization was performed easily without any
endoscopic or surgical procedure in 2 patients (6.7%) in group 1 who presented in
urinary retention after catheter removal. Wound infection and pelvic abscess
developed in 1 case (3.3%). There were no late complications. In group 2 urinary
retention developed in 1 patient (4%), wound infection in 1 (4%) and hematuria in
1 (4%). Two patients (8%) had late vesical neck contracture at 4 and 10 months,
respectively, which required urethrotomy in 1. In 1 patient (4%) a stricture in
the anterior urethra was dilated. CONCLUSIONS: Our study shows that early
catheter removal may be accomplished safely in most patients after radical
retropubic prostatectomy, and was not associated with a higher complication rate.
PMID- 10687992
TI - Multicenter patient self-reporting questionnaire on impotence, incontinence and
stricture after radical prostatectomy.
AB - PURPOSE: We determined the incidence of patient self-reported post-prostatectomy
incontinence, impotence, bladder neck contracture and/or urethral stricture,
sexual function satisfaction, quality of life and willingness to undergo
treatment again in a large multicenter group of men who underwent radical
prostatectomy. We also determined whether the morbidities of sexual function
satisfaction, quality of life and bladder neck contracture and/or urethral
stricture are predictable from demographic and postoperative prostate cancer
factors. MATERIALS AND METHODS: A self-reporting questionnaire was completed and
returned by 1,069 of 1,396 eligible patients (77%) who underwent radical
prostatectomy between 1962 and 1997. Of the respondents 868 (85.7%) underwent
surgery after 1990 and in all prostatectomy had been done a minimum of 6 months
previously. Questionnaire results were independently analyzed by a third party
for morbidity tabulation and the association of patient reported satisfaction.
RESULTS: The patient self-reported incidence of any degree of post-prostatectomy
incontinence, impotence and bladder neck contracture or urethral stricture was
65.6%, 88.4% and 20.5%, respectively. The incidence of incontinence requiring
protection was 33% and only 2.8% of respondents had persistent bladder neck
contracture or urethral stricture. Although incontinence and impotence
significantly affected self-reported sexual function satisfaction, quality of
life and willingness to undergo treatment again (p = 0.001), 77.5% of patients
would elect surgery again. This finding remained true even after adjusting for
demographic variables, and the time between surgery and the survey by multiple
logistic regression. CONCLUSIONS: Although radical prostatectomy morbidity is
common and affects self-reported overall quality of life, most patients would
elect the same treatment again. Impotence and post-prostatectomy incontinence
were significantly associated with sexual function satisfaction, quality of life
and willingness to undergo treatment again. Bladder neck contracture and/or
urethral stricture was associated with willingness to undergo treatment again
after adjusting for demographic variables and time from surgery to the survey.
PMID- 10687994
TI - The effect of hospital volume on mortality and resource use after radical
prostatectomy.
AB - PURPOSE: The value of radical prostatectomy for patients with prostate cancer
depends on low morbidity and mortality. We assessed whether patient outcome is
associated with how many of these procedures are performed at hospitals yearly.
MATERIALS AND METHODS: Using the Nationwide Inpatient Sample, which is a
stratified probability sample of American hospitals, we identified 66,693 men who
underwent radical prostatectomy between 1989 and 1995. Cases were categorized
into volume groups according to hospital annual rate of radical prostatectomies
performed, including low-fewer than 25, medium-25 to 54 and high-greater than 54.
We performed multivariate logistic regression to control for patient
characteristics when assessing the associations of hospital volume, in-hospital
mortality and resource use. RESULTS: Overall adjusted in-hospital mortality after
radical prostatectomy was relatively low (0.25%). However, patients at low volume
centers were 78% more likely to have in-hospital mortality than those at high
volume centers (adjusted odds ratio 1.78, 95% confidence interval 1.7 to 2.6).
Overall length of stay decreased at all hospitals between 1989 and 1995. However,
average length of stay was longer and total hospital charges were higher at low
than at high volume centers (7.3 versus 6.1 days, p<0.0001, and $15,600 versus
$13,500, p<0.0001, respectively). CONCLUSIONS: Hospital volumes inversely related
to in-hospital mortality, length of stay and total hospital charges after radical
prostatectomy. Further study is necessary to examine the association of hospital
volume with other important outcomes, including incontinence, impotence and long
term patient survival after radical prostatectomy.
PMID- 10687995
TI - Quality of life after prostatectomy.
PMID- 10687996
TI - Urinary tract infection prophylaxis using Escherichia coli 83972 in spinal cord
injured patients.
AB - PURPOSE: Escherichia coli 83972 was previously shown to establish bladder
colonization in select patient groups. We evaluate the safety and feasibility of
using bacterial interference with E. coli 83972 to prevent urinary tract
infection in spinal cord injured patients. MATERIALS AND METHODS: A total of 21
men and women with neurogenic bladder secondary to spinal cord injury underwent
intravesical inoculation with E. coli 83972. Frequency of symptomatic urinary
tract infection before and after colonization was compared. RESULTS: Successful
long-term bladder colonization was achieved in 13 study participants. Mean
duration of colonization was 12.3 months (range 2 to 40). Subjects had no
symptoms of urinary tract infection while colonized with E. coli 83972 (0
infection per 18.4 patient-years). Successfully colonized subjects had
experienced a mean of 3.1 symptomatic urinary tract infections per year (range 2
to 7) before colonization. Symptomatic infection also occurred in 4 subjects who
were not successfully colonized with E. coli 83972 and in 7 others after
spontaneous loss of colonization. Colonized subjects reported subjective
improvement in quality of life with respect to urinary tract infection while
colonized. CONCLUSIONS: E. coli 83972 may be safely used to establish long-term
asymptomatic bladder colonization in spinal cord injured subjects. Preliminary
findings suggest that colonization with E. coli 83972 may reduce the frequency of
urinary tract infection in patients with neurogenic bladder secondary to spinal
cord injury.
PMID- 10687997
TI - A new technique for transurethral resection of superficial bladder tumor in 1
piece.
AB - PURPOSE: We developed a new transurethral resection technique that not only
removes the entire tumor, but also the surrounding mucosa and underlying stroma
with superficial proper muscle in 1 piece to determine accurately the depth of
invasion and infiltration pattern of superficial bladder cancer. MATERIALS AND
METHODS: A short curved needle electrode is used to make a circular incision
around and level incisions underneath the tumor, and for tumor retrieval.
RESULTS: Tissue sections of the cut surface crossing the tumor center revealed
accurate histology regarding the growth pattern and depth of invasion. No
perforation, uncontrollable bleeding or other serious complications occurred.
CONCLUSIONS: More accurate histological diagnosis regarding the growth pattern
and depth of lamina propria invasion was possible with removal of the tumor and
surrounding material in 1 piece compared to conventional transurethral resection.
PMID- 10687998
TI - A simple technique to identify catheter balloon defects.
PMID- 10687999
TI - Studies of the latency of pelvic floor contraction during peripheral nerve
evaluation show that the muscle response is reflexly mediated.
AB - PURPOSE: Whether neuromodulation using an implanted sacral nerve stimulator acts
by its effects on pelvic afferent or efferent nerves remains to be determined.
However, it has been observed that eliciting an "anal wink" is helpful in the
optimal siting of the foraminal stimulating electrode. This observation has been
interpreted as indicating that a direct effect on efferent pelvic innervation is
an important functional component of the technique. We studied the latency of
this motor response to determine whether it is consistent with neuromodulation
working via a direct efferent mechanism. MATERIALS AND METHODS: We studied 9
women with urinary retention undergoing the first stage of a stimulator implant
(peripheral nerve evaluation). Stimulation was applied to an electrode placed in
the S3 foramen and the latency of the response of the striated anal sphincter, a
contraction which gives rise to the "anal wink," was measured using a concentric
needle electrode placed in the striated part of the anal sphincter. RESULTS: Mean
latency of response was 98 milliseconds (range 52 to 140), which is approximately
10 times longer than would be expected from that resulting from direct motor
nerve stimulation. CONCLUSIONS: Our results indicate that anal sphincter
contraction observed during peripheral nerve evaluation is the result of an
afferent mediated response.
PMID- 10688000
TI - Surgical treatment for stress urinary incontinence associated with valsalva
induced detrusor instability.
AB - PURPOSE: Detrusor instability initiated by increased intra-abdominal pressure
that results in incontinence has always been difficult to treat. This form of
incontinence may be due to traction on the pelvic nerves when increased abdominal
pressure is applied to already weakened pelvic supportive tissue. In most
patients pharmacological attempts to correct this problem fail. We describe a
pubovaginal sling designed to stabilize the urethrovesical junction during the
Valsalva maneuver, which is our treatment of choice for such patients. MATERIALS
AND METHODS: From 1994 to 1998 we treated 36 patients with a pubovaginal sling
procedure for Valsalva induced detrusor instability diagnosed on preoperative
urodynamics. The sling material was in situ vaginal wall in 20 cases, free swing
vaginal wall in 6, rectus fascia in 4, cadaveric fascia in 3 and synthetic
material in 3. Urodynamic evaluation was performed preoperatively in all
patients. Followup of 6 months to 4 years involved subjective questions and
objective examination. RESULTS: Cure was achieved in 33 of the 36 patients (92%),
of whom leak point pressure was less than 50, 50 to 100 and greater than 100 cm.
water in 9, 17 and 7, respectively. In the 3 failed cases leak point pressure was
50 to 100 cm water, including 2 in which cotton swab test results were less than
30 degrees. Urge incontinence resolved in 75% of the patients. CONCLUSIONS: The
pubovaginal sling procedure may cure Valsalva induced detrusor instability. Leak
point pressure does not determine which patients do well. Evaluation for
hypermobility may help to predict the success or failure of a procedure by
identifying those in whom Valsalva induced detrusor instability results from
traction on the pelvic nerves.
PMID- 10688001
TI - Report of the international consensus development conference on female sexual
dysfunction: definitions and classifications.
AB - PURPOSE: Female sexual dysfunction is highly prevalent but not well defined or
understood. We evaluated and revised existing definitions and classifications of
female sexual dysfunction. MATERIALS AND METHODS: An interdisciplinary consensus
conference panel consisting of 19 experts in female sexual dysfunction selected
from 5 countries was convened by the Sexual Function Health Council of the
American Foundation for Urologic Disease. A modified Delphi method was used to
develop consensus definitions and classifications, and build on the existing
framework of the International Classification of Diseases-10 and DSM-IV:
Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric
Association, which were limited to consideration of psychiatric disorders.
RESULTS: Classifications were expanded to include psychogenic and organic causes
of desire, arousal, orgasm and sexual pain disorders. An essential element of the
new diagnostic system is the "personal distress" criterion. In particular, new
definitions of sexual arousal and hypoactive sexual desire disorders were
developed, and a new category of noncoital sexual pain disorder was added. In
addition, a new subtyping system for clinical diagnosis was devised. Guidelines
for clinical end points and outcomes were proposed, and important research goals
and priorities were identified. CONCLUSIONS: We recommend use of the new female
sexual dysfunction diagnostic and classification system based on physiological as
well as psychological pathophysiologies, and a personal distress criterion for
most diagnostic categories.
PMID- 10688002
TI - Ossifying cavernous hemangioma masquerading as adrenal tuberculosis.
PMID- 10688003
TI - Unusual presentations of hydatid disease of the urinary tract.
PMID- 10688004
TI - Orthotopic renal transplantation in a patient with a massive pelvic arteriovenous
malformation.
PMID- 10688005
TI - Adenocarcinoma in an Indiana pouch urinary diversion.
PMID- 10688006
TI - Angiomyolipoma of the bladder wall.
PMID- 10688007
TI - Squamous cell carcinoma of the urachus.
PMID- 10688008
TI - Carcinoma of the female urethra responsive to moderate dose chemoradiotherapy.
PMID- 10688009
TI - Priapism as a complication of high dose testosterone therapy in a man with
hypogonadism.
PMID- 10688010
TI - An unusual case of a metastatic lesion to the penis.
PMID- 10688011
TI - Magnetic resonance imaging to diagnose segmental testicular infarction.
PMID- 10688012
TI - Extragonadal germ cell tumor of mediastinum with high serum level of
carcinoembryonic antigen and carbohydrate antigen 19-9.
PMID- 10688013
TI - Basal cell carcinoma of the scrotum.
PMID- 10688014
TI - Hemospermia and expressed tumor in the urethra: an unusual presentation of ductal
carcinoma of the prostate.
PMID- 10688015
TI - Media hype in the medical literature: what's a doctor to do?
PMID- 10688016
TI - Sildenafil and the Internet.
AB - PURPOSE: The Internet is changing the way medicine is being practiced and
challenging our notions of the doctor-patient relationship. We analyze the
development of online prescriptions and propose guidelines for the sale of
sildenafil over the Internet. MATERIALS AND METHODS: Using MEDLINE, Medscape and
Lexis-Nexis search engines we reviewed pertinent materials from January 1996 to
July 1999 focusing on the keywords Viagra, prescription and Internet. The review
included press releases, law review articles, case law, medical literature,
pending litigation, proposed legislation, and federal and state statutes.
RESULTS: Online prescriptions are an outgrowth of the mail order drug business.
This development continues the historic innovations in communications and
transportation that have enabled physicians to practice medicine over long
distances while maintaining ties to hospitals and other specialists. While the
sale of sildenafil over the Internet may be profitable and convenient, it raises
a variety of legal, ethical and safety concerns. Many federal and state
organizations have addressed the issue without establishing a clear standard.
CONCLUSIONS: A clear distinction exists between online prescriptions and
pharmacies. While it may be acceptable for sildenafil to be sold over the
Internet given current technologies, it must be done within the confines of a
traditional doctor-patient relationship. Online prescriptions must be limited to
patients who live in states in which the prescribing physician is licensed.
Failure to establish a doctor patient relationship in this context breeches
ethical standards, and may give rise to potential civil and criminal liabilities.
PMID- 10688017
TI - Re: unenhanced computerized axial tomography to detect retained calculi after
percutaneous ultrasonic lithotripsy.
PMID- 10688018
TI - Re: successful living related kidney transplantation despite renal angiomyolipoma
in situ.
PMID- 10688019
TI - Re: 13-year experience with percutaneous management of upper tract transitional
cell carcinoma.
PMID- 10688020
TI - Re: orthotopic urinary diversion with preservation of erectile and ejaculatory
function in men requiring radical cystectomy for nonurothelial malignancy: a new
technique.
PMID- 10688021
TI - Re: orthotopic urinary diversion with preservation of erectile and ejaculatory
function in men requiring radical cystectomy for nonurothelial malignancy: a new
technique.
PMID- 10688022
TI - Re: editorial: gender assignment and the pediatric urologist.
PMID- 10688023
TI - Cystic testicular lesions in the pediatric population.
AB - PURPOSE: We present the etiology, histological evaluation and management of all
cystic lesions of the pediatric testis. MATERIALS AND METHODS: Illustrative cases
from our experience are reported with a literature review of all possible
diagnoses. RESULTS: Included in the differential diagnosis of cystic testis
lesions in children are epidermoid cyst, dermoid cyst, prepubertal teratoma,
juvenile granulosa cell tumor, cystic dysplasia of the rete testis, testicular
cystic lymphangioma, simple cyst and cystic degeneration after torsion. Testis
sparing surgery is feasible in many circumstances. CONCLUSIONS: Cystic lesions of
the pediatric testis are rare but represent an interesting group of diagnoses.
Patient age at presentation, examination features, tumor markers and sonographic
appearance may assist in making a presumptive and occasionally definitive
diagnosis preoperatively. Based on the likely diagnosis enucleation or partial
orchiectomy may be considered when performed with frozen section histological
assessment. A thorough understanding of potentially cystic testis lesions in
children leads to the best management choices and often to preservation of a
substantial portion of the affected testis.
PMID- 10688024
TI - Comparison of laparoscopic versus open nephrectomy in the pediatric population.
AB - PURPOSE: Laparoscopic renal surgery has become an accepted approach for benign
disease in adults. We compare our experience with laparoscopic and open
nephrectomy in a pediatric population. MATERIALS AND METHODS: A total of 10
pediatric patients underwent laparoscopic nephrectomy or nephroureterectomy and
an additional 10 consecutive children underwent similar open procedures. All
patients had benign disease and were treated at a single institution. Medical
records were reviewed retrospectively for relevant clinical data. RESULTS:
Planned surgery was completed in all cases. There were no conversions to open
surgery in the laparoscopic group. Mean operative time was 175.6 versus 120.2
minutes (p = 0.01) and mean hospital stay was 22.5 versus 41.3 hours (p = 0.03)
in the laparoscopic and open nephrectomy groups, respectively. Blood loss was not
statistically different. Analgesic use was qualitatively less in the laparoscopic
nephrectomy group. CONCLUSIONS: Laparoscopic nephrectomy and nephroureterectomy
may be performed safely in children. While operative time was somewhat longer in
our initial laparoscopic series, postoperative hospital stay was significantly
shorter than for open surgery. Further experience with this technique is
warranted.
PMID- 10688025
TI - The modern endoscopic approach to ureterocele.
AB - PURPOSE: During the last 20 years the surgical approach to ureterocele has
evolved from major open surgery to minimally invasive endoscopic puncture. We
believe that the endoscopic approach decreases the need for open surgical
procedures. We identified specific factors that predict the need for repeat
surgery. MATERIALS AND METHODS: We reviewed the charts of 60 new patients with
ureterocele treated with primary endoscopic incision between 1991 and 1995.
Followup ranged from 4 to 62 months (mean 20). Mode of presentation, ureterocele
location, associated vesicoureteral reflux and association of the ureterocele
with a duplex system were evaluated. Ureterocele wall thickness was assessed
subjectively via radiographic and cystoscopic methods, and categorized as thin,
intermediate and thick. RESULTS: All 9 patients with a single system ureterocele
had an intravesical ureterocele. No patient had associated reflux nor did any
require a secondary open procedure. In 3 cases new onset ipsilateral reflux into
the ureterocele spontaneously resolved. Of the 51 patients with a duplex system
and associated ureterocele 19 (37%) required a secondary open procedure. The
ureterocele was intravesical and ectopic in 22 (43%) and 29 (57%) cases,
respectively. Reflux was associated with the ureterocele in 27 patients (53%),
and 12 (44%) required a secondary open procedure. A total of 11 patients
underwent ureteral reimplantation of 15 refluxing renal units and only 2 renal
units required ureteral tapering. Reflux is no longer present in 14 of the 15
renal units (93%). Patients with a thick walled ureterocele required repeat
puncture more frequently than those with a nonthick ureterocele. CONCLUSIONS:
With the use of modern endoscopic techniques children with intravesical and
single system ureteroceles require secondary open surgery less frequently than
those with ectopic and duplex system ureteroceles. The mode of presentation does
not predict the need for a repeat open procedure. Thick walled ureteroceles
require repeat endoscopic puncture more frequently than thin and intermediate
walled ureteroceles.
PMID- 10688026
TI - Bifid mesonephric duct presenting as a scrotal urinoma.
PMID- 10688027
TI - Transureteroureterostomy in childhood and adolescence: long-term results in 69
cases.
AB - PURPOSE: We analyzed a series of 69 transureteroureterostomies to evaluate long
term results and specify current indications. MATERIALS AND METHODS: Between 1969
and 1998 transureteroureterostomy was performed in 32 females and 37 males with a
mean age of 8.6 years. Surgery was done to avoid repeat or difficult ureteral
reimplantation after multiple failed procedures in 22 cases and to create a
continent ureteral conduit for intermittent catheterization in 23. Other
indications included undiversion in 8 cases, ureterocystoplasty in 6, diversion
in 4, the Kropp procedure in 3, massively dilated megaureter in 2 and ureteral
necrosis in 1. Of the 69 patients 6 were lost to followup and 63 were followed at
least 1 year (median 6). RESULTS: A total of 63 patients were regularly monitored
by clinical observation and morphological investigation, including ultrasound,
excretory urography and cystography. In 50 cases (79.4%) results were good with
no upper urinary tract dilatation. All initially normal donor ureters remained
normal. Of 51 initially dilated donor ureters 40 (78.4%) improved or returned to
normal, while 20 of 27 initially dilated recipient ureters (74.1%) improved or
returned to normal. Serious complications in 3 cases (4.3%) involved anastomotic
leakage, ischemic stenosis of the common ureteral trunk and progressive
deterioration of function in 1 kidney requiring nephrectomy 3 years
postoperatively. Reoperation was successful in the former 2 cases. CONCLUSIONS:
With careful attention to technique transureteroureterostomy represents a safe
and reliable procedure with well-defined indications in pediatric urology.
PMID- 10688028
TI - Y duplication of urethra with complete atresia of the orthotopic channel: 1-stage
reconstruction.
PMID- 10688029
TI - Hypospadias and urethral development.
AB - PURPOSE: Hypospadias is a common congenital anomaly that may be treated with
surgical reconstruction. In the majority of cases the etiology remains elusive.
Although androgens are clearly critical for penile development, defects in
androgen metabolism and/or the androgen receptor explain only a small subset of
cases of hypospadias. Strategies are presented for understanding the etiology of
hypospadias. MATERIALS AND METHODS: Current scientific reports on the etiology of
hypospadias were reviewed, and the embryology and possible mechanisms of urethral
and penile formation are presented. RESULTS: A new theory of glandular human
urethral development via endodermal cellular differentiation is proposed to
replace the classic explanation of ectodermal intrusion. CONCLUSIONS: Careful
studies of penile and urethral development have led to a better understanding of
genital embryology. Future areas of study, such as endocrine disrupters,
mesenchymal-epithelial interactions and mechanisms of penile growth, are proposed
to explain the etiology of hypospadias.
PMID- 10688030
TI - Vanished testis: be aware of an abdominal testis.
PMID- 10688031
TI - Laparoscopic diagnosis and clinical management of a solitary nonpalpable
cryptorchid testicle in a postpubertal male.
PMID- 10688032
TI - Ectopic and undescended testes: 2 variants of a single congenital anomaly?
AB - PURPOSE: We compared pathological findings in ectopic and undescended testis to
determine whether the pathological evidence supports the hypothesis that the 2
conditions are variants of the same congenital anomaly. MATERIALS AND METHODS: We
identified 24 boys with ectopic testis not in the superficial inguinal pouch of
Denis Browne. Seven boys were excluded from study due to unavailable clinical
records for 3, contralateral undescended testis in 2 and inadequate biopsy
specimens in 2. Pathological findings of ectopic testis in the remaining 17
patients were compared with those of age matched patients with unilateral
undescended testis. Total germ cell count, testicular volume, patency of the
processus vaginalis and epididymal abnormalities were compared. Data were
analyzed using the Wilcoxon matched pairs signed rank and Fisher's exact tests.
RESULTS: No difference was noted in total germ cell count (p = 0.33), testicular
volume (p = 0.1475), processus vaginalis patency (p = 0.0854) or epididymal
abnormalities (p = 1.00) in the 2 groups. Of the 24 boys (8%) with ectopic testis
2 also had a contralateral undescended testis. CONCLUSIONS: Similar pathological
findings in ectopic and undescended testes as well as the association of ectopic
testis with a contralateral undescended testis suggest that ectopic and
undescended testes are variants of the same congenital anomaly. Thus, boys with
ectopic testis may have an increased incidence of subfertility and testicular
malignancy. This spectrum of abnormal testicular position, and its range of
pathological conditions and complications may appropriately be called the
undescended testis sequence.
PMID- 10688033
TI - The predictive value of inguinal herniography for the diagnosis and treatment of
cryptorchidism.
AB - PURPOSE: We evaluated the role of a patent processus vaginalis for cryptorchidism
as well as inguinal herniography as a predictor of the efficacy of human
chorionic gonadotropin (HCG) treatment. MATERIALS AND METHODS: We studied 244
boys with unilateral and 66 with bilateral cryptorchidism. All patients underwent
inguinal herniography and received HCG. Nonresponders to treatment subsequently
underwent orchiopexy, when processus vaginalis status, testicular position and
epididymal characteristics were assessed. RESULTS: HCG was effective for 139 of
281 testes (49.5%) with an obliterated and 0 of 95 with a patent processus
vaginalis on herniography. We further evaluated herniography in accordance with
orchiopexy findings of persistent unilateral and bilateral cryptorchidism in 206
boys (237 testes) after HCG. Herniography findings of processus vaginalis
morphology revealed a close correlation with that reported by the surgeon after
orchiopexy (p<0.000005). The incidence of a patent processus vaginalis increased
as testicular position became more caudal. The processus vaginalis was
obliterated in all cases of anorchia. The incidence of more severe epididymal
anomalies decreased as the testicular position became more caudal. Epididymal
abnormalities were more common when the processus vaginalis was patent.
CONCLUSIONS: Pretreatment herniography assessment of processus vaginalis
morphology is of prognostic value for predicting the efficacy of hormone
treatment, the presence or absence of testes when they are nonpalpable and future
fertility.
PMID- 10688034
TI - Expression profile of an androgen regulated prostate specific homeobox gene
NKX3.1 in primary prostate cancer.
AB - PURPOSE: NKX3.1, a member of the family of homeobox genes, exhibits prostate
tissue specific expression and appears to play a role in mouse prostate
development. Rapid induction of NKX3.1 gene expression in response to androgens
has also been described. On the basis of the established role of androgens in
prostatic growth and differentiation and studies showing an association of
aberrant homeobox gene expression with the neoplastic process, we hypothesize
that alterations of NKX3.1 gene expression play a role in prostate tumorigenesis.
MATERIALS AND METHODS: NKX3.1 expression was analyzed in matched, microdissected
normal and tumor tissues from 52 primary prostate cancer specimens from radical
prostatectomy by semiquantitative RT-PCR and in situ hybridization and correlated
with the clinicopathologic features. NKX3.1 expression was quantified as
differential expression between matched tumor and normal tissues and was grouped
as overexpression in tumor tissue, reduced expression in tumor tissue and no
change between tumor and normal tissues. Androgen regulation of NKX3.1 expression
was also studied in LNCaP cells. Androgen receptor (AR) expression in prostate
tumor and normal tissue was correlated with NKX3.1 expression. RESULTS:
Comparison of NKX3.1 expression between normal and tumor tissues revealed
overexpression in 31% tumor specimens (16 of 52), decreased expression in 21%
tumor specimens (11 of 52) and no change in 48% specimens (25 of 52). When these
expression patterns were stratified by organ confined and non-organ-confined
tumor, a higher percentage of patients exhibited NKX3.1 overexpression in non
organ confined tumor (40%) versus organ confined tumor (22%). Elevated NKX3.1
expression significantly correlated with tumor volume and serum prostate specific
antigen (PSA) level in the NKX3.1 overexpression group (p<0.05). Metastatic
prostate cancer cell lines did not exhibit mutations in the protein coding
sequence of NKX3.1. Additionally, the NKX3.1 expression correlated with AR
expression (p<0.01) in vivo in human prostate tissues. Comparison of PSA and
NKX3.1 expression in response to androgen revealed a rapid androgen mediated
induction of NKX3.1 expression in LNCaP cells. In situ hybridization analysis of
representative specimens confirmed RT-PCR observations. CONCLUSIONS: These
results suggest an association of NKX3.1 with a more aggressive phenotype of
carcinoma of the prostate. Correlation of AR expression with NKX3.1 in human
prostate tissues underscores the androgen regulation of NKX3.1 in the physiologic
context of human prostate tissues.
PMID- 10688035
TI - Characterization of ureteral dysfunction in an experimental model of congenital
bladder outlet obstruction.
AB - PURPOSE: Ureteral dysfunction is a significant sequela of congenital bladder
outlet obstruction. However, the structural and functional alterations associated
with ureteral dysfunction are not well defined. A model of fetal bladder
obstruction in sheep was used to characterize the changes in ureteral smooth
muscle, extracellular matrix (ECM) and functional properties in response to
bladder outlet obstruction. MATERIALS AND METHODS: Partial bladder outlet
obstruction was created in fetal sheep at gestational age 95 days via placement
of a metal ring around the proximal urethra as well as ligation of the urachus.
Ureters were harvested at 109 and 135 days (full term = 140 days) to determine
the relative composition of smooth muscle, ECM and urothelium by morphometric
analysis and to measure DNA and protein concentrations. Ureteral tissue from 135
day gestation obstructed and control sheep was harvested and immediately placed
in Krebs solution. Smooth muscle strips (2-3 mm. x 7-8 mm.) were suspended in
organ baths. The frequency and amplitude of spontaneous ureteral contractions was
as well as the response to electric field stimulation (EFS) were determined.
RESULTS: Bladder outlet obstruction caused a significant increase in ureteral
weight, smooth muscle mass and total ECM at both 109 and 135 days gestation.
Total ureteral DNA was greater in obstructed compared with sham ureters at 135
days gestation. Obstructed ureters demonstrated greater amplitude and frequency
of spontaneous contractions as well as more pronounced response to EFS when
compared to sham ureters. CONCLUSIONS: The fetal ureter responds to bladder
obstruction with smooth muscle hyperplasia and hypertrophy which is associated
with increased spontaneous activity and augmented response to EFS. ECM content is
markedly increased indicating a shift in the balance of connective tissue
synthesis and degradation. Congenital post-obstructive ureteral dysfunction
therefore appears to be the result of dysregulated smooth muscle cell growth and
altered ECM homeostasis producing abnormal ureteral contractility.
PMID- 10688036
TI - Cell-cell adhesion molecules and signaling intermediates and their role in the
invasive potential of prostate cancer cells.
AB - PURPOSE: The highly variable natural history of prostate carcinoma may be
reflected in heterogeneity of invasive potential between tumors. MATERIALS AND
METHODS: We have examined two prostate cancer cell lines of low invasive
potential (CAHPV10 and PZHPV7) and three cell lines of high invasive potential
(DU-145, PC-3, LNCapFGC), to determine whether specific adhesion molecule
profiles correlated with their invasive behavior. RESULTS: Using an in vitro
invasion assay, we demonstrated that DU-145, LNCapFGC and PC-3 cells were highly
invasive compared with CA-HPV-10 and PZ-HPV-7 cells. LNCapFGC cells expressed
high levels of E-cadherin, alpha-, beta- and gamma-catenin, desmoglein,
desmoplakin and GSK3beta using immunoblotting. This was, in general, comparable
to immunohistochemical staining. PC-3 cells had no E-cadherin or alpha-catenin,
but expressed a high level of the HGF/SF receptor c-Met. In contrast, DU-145
cells were found to express E-cadherin and low levels for all other protein
molecules, except c-Met. The DU-145 cell line also lacked alpha-catenin
expression. In CA-HPV-10 and PZ-HPV-7 cells, there was no detection of APC, PECAM
1, P-cadherin or Wnt-1. DU-145, LNCapFGC and PC-3 cells formed cell-cell
aggregates, which were reduced by inclusion of anti-E-cadherin antibody and the
motogen HGF/SF. CONCLUSION: These results show that prostate cancer cells exhibit
a diverse expression of cell-cell adhesion molecules and their signaling
intermediates. The expression of these adhesion molecules bears an important
relationship with the invasive phenotype of these cells.
PMID- 10688037
TI - Nuclear factor kappa B mediates lipopolysaccharide-induced inflammation in the
urinary bladder.
AB - PURPOSE: The proteins which constitute the final common pathway linking receptors
on cell surfaces to the inflammatory cascade have recently been identified and
cloned. Central to activation of this inflammatory cascade is translocation from
cytosol to nucleus of the nuclear transcription factor known as nuclear factor
kappa B (NF-kappaB). The purpose of this study was to determine whether NF-kappaB
cascade plays a role in lipopolysaccharide (LPS)-induced inflammation of the
mouse urinary bladder. MATERIALS AND METHODS: Bladder inflammation was induced in
anesthetized mice by intravesical instillation of lipopolysaccharide (LPS) and
quantified by morphometric analysis. The NK-1 receptors for substance P were
quantified by flow cytometry. LPS-induced degradation of inhibitory IkappaB
subunit was quantified by Western blotting analysis and translocation of NF
kappaB protein from cytosol to the nucleus was determined by confocal microscopy
and Western blotting analysis. In addition, we determine the effect of
lactacystin, a proteosome inhibitor, on LPS-induced IkappaB degradation and NF
kappaB translocation, NK-1 receptor fluorescence intensity, and bladder
inflammation. RESULTS: LPS instillation into the mouse bladder resulted in time
dependent loss of the inhibitory IkappaB subunit of the NF-kappaB protein
complex. IkappaB cleavage was followed by translocation of NF-kappaB from the
cytosol to the nucleus. This was associated with increased expression of an NF
kappaB dependent inflammatory component, the NK-1 receptor. Pretreatment of mouse
bladders with the NF-kappaB inhibitor, lactacystin, prevented cleavage of IkappaB
in a dose-dependent manner. Lactacystin prevented increases in the NF-kappaB
dependent inflammatory cascade components such as the NK-1 receptor. At the whole
tissue level, the marked inflammatory infiltrate and mucosal breakdown associated
with LPS administration was completely abolished by lactacystin. CONCLUSION: NF
kappaB mediates many features of urinary bladder inflammation induced by LPS. The
NF-kappaB cascade is an important target for anti-inflammatory management of
cystitis.
PMID- 10688038
TI - The effect of mycophenolate mofetil and polyphenolic bioflavonoids on renal
ischemia reperfusion injury and repair.
AB - PURPOSE: Chronic renal allograft nephropathy is associated with both immune and
ischemic injury which may act synergistically to promote an inflammatory
response. The immunosuppressant mycophenolic acid and the polyphenolic agents
curcumin and quercetin possess properties that might ameliorate such injury. We
studied the effects of these agents in models of ischemic renal injury and skin
allograft rejection. MATERIALS AND METHODS: Ischemic acute tubular necrosis was
produced in rats by renal pedicle occlusion with contralateral nephrectomy.
Animals were treated with mycophenolic acid, quercetin and curcumin, or a
combination of agents. Animals were killed on days 2 and 7 after operation and
tissue samples were collected. Renal tubular apoptosis and cellular proliferation
were assessed by immunohistochemistry. Expression of the cytokines RANTES and AIF
were evaluated by semi-quantitative reverse transcription polymerase chain
reaction (RT-PCR). RESULTS: Treatment with the polyphenolic compounds alone or in
combination with mycophenolic acid was associated with less tubular damage,
attenuation of renal inflammation, and prolongation of skin graft survival. A
combination of agents decreased serum creatinine on day 2 from 4.5 to 0.9 mg./dl.
(p< or =0.01) and at day 7 from 3.8 to 0.6 mg./dl. (p< or =0.01). Treatment with
the polyphenolic compounds inhibited apoptosis at day 2. By RT-PCR, RANTES and
AIF were detected at high levels on days 2 and 7. Treatment with these agents
alone or in combination strongly attenuated this increased expression.
CONCLUSIONS: The combination of mycophenolic acid with curcumin and quercetin
reduces renal injury and facilitates repair. These agents may have a role in
therapeutic regimens that are both immunosuppressive and renoprotective.
PMID- 10688039
TI - Hydro-jet assisted laparoscopic partial nephrectomy: initial experience in a
porcine model.
AB - PURPOSE: Hemostasis represents a challenge when performing laparoscopic partial
nephrectomy. Hydro-Jet cutting is an advanced technology that has been used to
create an ultra-coherent water force that functions like a sharp knife. In the
surgical field, it has mainly been used for liver surgery and initial clinical
experience with laparoscopic cholecystectomies has been favorable. This technique
allowed selective parenchymal cutting with preservation of vessels and bile
ducts. We describe a novel Hydro-Jet assisted dissection technique for
laparoscopic partial nephrectomy in a porcine model. MATERIALS AND METHODS: Ten
partial nephrectomies were performed in 5 pigs using a Muritz 1000 (Euromed
Medizintechnik, A. Pein, Schwerin, Germany) Hydro-Jet generator. A thin stream of
ultra coherent fluid is forced at a high velocity through a small nozzle. A
modified probe allows both blunt dissection concomitantly with high-pressure
water application. Coagulation can be applied via a bipolar thermoapplicator as
needed. RESULTS: Laparoscopic partial nephrectomy was successful in all animals.
Water-jet cutting through the parenchyma was virtually bloodless and preserved
the vasculature and the collecting system. The vessels were then ligated or
coagulated under direct vision. The continuous water flow established a bloodless
operating field and a clear view for the surgeon. The mean dissection time and
warm ischemia time were 45+/-9 and 17+/-3 minutes, respectively. CONCLUSIONS:
This preliminary study supports the suitability of this technique for
laparoscopic partial nephrectomy to improve hemostasis. The improved anatomical
dissection and hemostasis may further decrease morbidity and operative time.
Further studies are underway to compare this technique with laser coagulation for
laparoscopic partial nephrectomy.
PMID- 10688040
TI - Recruitment, distribution and phenotypes of mast cells in interstitial cystitis.
AB - PURPOSE: Interstitial cystitis (IC) is a chronic disabling condition of unknown
etiology. One of its major characteristics is an increase in mast cells (MC)
showing signs of activation. It has been suggested that the proteinase content
defines two MC types: MC(TC), containing chymase and tryptase, and MC(T), which
contains tryptase but lacks chymase. Here, we investigated the MC distribution
and the MC proteinase expression in IC together with the tissue expression of the
major MC growth factors, stem cell factor (SCF) and interleukin-6 (IL-6).
MATERIALS AND METHODS: MC were enumerated in bladder specimens from patients with
classic IC, nonulcer IC and controls. MC were visualized in terms of
metachromasia, reflecting glycosaminoglycan content, and immunohistochemically,
visualizing tryptase, chymase and IL-6 as well as the surface markers CD117 and
SCF. RESULTS: Classic IC displayed a 6 to 10-fold increase of MC identified by
proteinase content while in nonulcer IC there were twice as many MC as in
controls. In contrast to nonulcer IC and controls, classic IC displayed an
abundance of epithelial MC. Fewer CD117+ than proteinase+ MC were detected in IC
but not in controls. Classic IC coexpressed SCF and IL-6 in the epithelium and
displayed numerous SCF and IL-6+ cells in the mucosa and detrusor muscle, many of
which were MC. CONCLUSIONS: Redistribution of MC into the epithelium and a high
bladder wall MC density distinguish classic IC from nonulcer IC. Our findings
suggest an SCF/IL-6-driven MC response in IC. They also indicate a downregulation
of the SCF receptor in IC.
PMID- 10688041
TI - Immunobiologic, cytogenetic and drug response features of a newly established
cell line (SCRC-1) from renal small cell carcinoma.
AB - PURPOSE: We describe the establishment and preliminary characterization of a cell
line designated SCRC-1, which was derived from a primary renal small cell
carcinoma. MATERIALS AND METHODS: Continuous cultures of a primary stage IVa
renal small cell carcinoma and a xenograft in nude mice derived therefrom were
characterized by immunohistology, electron microscopy, immunofluorescence/flow
cytometry, cytogenetic analysis, and an in vitro drug resistance assay. RESULTS:
SCRC-1 cells were reactive with antibodies to NSE, chromogranin-A, bombesin, Bcl
2, CD44s, CD44v6, CD44v7 to 8, vimentin and S100 protein (predominantly beta
subunit), and were unreactive with antibodies to EMA, CD54, EGFR(R1), URO-5, URO
7, URO-8 and URO-10. A similar immunoprofile was also found in both the primary
tumor and the xenograft. Cytogenetic analysis revealed the following common
clonal aberrations in all 50 metaphases analyzed: 45, XX, t (X;10;18)
(p11;p11;q11), -der(18)t(X;10;18), indicating the clonal nature of this neoplasm.
SCRC-1 cells showed low drug resistance to cyclophosphamide, doxorubicin,
gemcitabine and fluorouracil, intermediate resistance to carmustine and mitomycin
C, and extreme resistance to cisplatin. CONCLUSION: We have documented the
initial characterization of SCRC-1, which may be the first cell line reported to
be derived from a primary small cell carcinoma of the kidney. This cell line can
be used for further studies uncovering the biology and histogenesis of this rare
cancer and delineating differences among small cell carcinomas of the kidney and
other histological types.
PMID- 10688042
TI - Efficacy of microtubule-active drugs followed by ketoconazole in human metastatic
prostate cancer cell lines.
AB - PURPOSE: Once a relapse occurs following primary endocrine treatment, metastatic
prostate cancer is one of the most therapy-resistant human neoplasms.
Ketoconazole is used for complete androgen deprivation, and recent data suggest
it has direct activity against prostate cancer cells. MATERIALS AND METHODS:
LNCaP, DU145, and PC3 cells, human prostate cancer cell lines, and HL60, a human
leukemia cell line, were lysed and soluble proteins were harvested. Cells were
plated in 96-well flat bottom plates and then exposed to the pharmacological
agents, ketoconazole, vinblastine and paclitaxel. DNA synthesis was monitored by
3H-thymidine incorporation. RESULTS: We demonstrate that ketoconazole exerts a
cytostatic effect on a panel of human prostate cancer cell lines, with IC50 of 4
to 5 microg./ml., 12 microg./ml., and 25 microg./ml. for LNCaP, PC3/PC3M, and
DU145 cells, respectively. On the other hand, using microtubule-active drugs,
vinblastine and paclitaxel, we found that PC3M and PC3 cells were more resistant
than either DU145 or LNCaP cells. This resistance was associated with a lesser
degree of Raf-1 and Bcl-2 phosphorylation following exposure to microtubule
active drugs. Combinations of microtubule-active drugs with ketoconazole were a
beneficial treatment in DU145 cancer cells. Furthermore, ketoconazole blocked
recovery of all the prostate cancer cell lines following 24 hours-pulse treatment
with vinblastine. CONCLUSION: Pulse-administration of vinblastine followed by
continuous administration of ketoconazole warrants investigation in the treatment
of hormone-independent metastatic prostate cancer.
PMID- 10688043
TI - Mitogenic signaling in androgen sensitive and insensitive prostate cancer cell
lines.
AB - PURPOSE: To investigate the role of a specific mitogen activated protein kinase,
extracellular signal-regulated kinase (ERK), in regulating cell proliferation
induced by three potentially important prostate cancer mitogens that signal via
different classes of receptors. MATERIALS AND METHODS: Androgen sensitive (LNCaP)
and insensitive (PC-3) prostate cancer cell lines were used in these studies.
Epidermal growth factor (EGF), lysophosphatidic acid (LPA), and
dihydrotestosterone (DHT) were the mitogenic stimulants and AG1478, a receptor
tyrosine kinase inhibitor, and PD98059, an inhibitor of MEK, were the chemical
inhibitors used in this study. Cell proliferation was measured using the WST-1
assay and ERK expression and activation was determined by immunoblotting for
phospho- and total ERK. RESULTS: In androgen-sensitive LNCaP cells, epidermal
growth factor (EGF) and dihydrotestosterone (DHT) both enhanced cell
proliferation. EGF-stimulation dramatically increased ERK phosphorylation while
DHT did not. In the androgen-insensitive cell line, PC-3, EGF- and LPA-induced
ERK phosphorylation and cell proliferation. Inhibition of EGF- and LPA- induced
ERK activation with the EGF receptor inhibitor, AG1478, or the MEK inhibitor,
PD98059, attenuated their proliferative effects. Neither inhibitor had an effect
on DHT stimulated cell proliferation. CONCLUSIONS: These data demonstrate
heterogeneity of mitogenic signaling in prostate cancer cells, and support the
hypothesis that androgens and growth factors utilize divergent signaling pathways
in prostate cancer to induce proliferation.
PMID- 10688044
TI - The growth inhibitory effect of p21 adenovirus on human bladder cancer cells.
AB - PURPOSE: To evaluate whether p21 (WAF-1/CIP1) should be considered a potential
candidate for human bladder cancer gene therapy, we determined: (1) the basal
level of p21 expression in bladder cancer cell lines, (2) the response of bladder
cancer cells to increased p21 expression following p21 adenovirus infection, and
(3) the mechanism of growth inhibition produced by p21 overexpression. MATERIALS
AND METHODS: Five established human bladder cancer cell lines and one primary
culture derived from an invasive transitional cell carcinoma were used in this
study. To examine the effect of p21 protein on the growth of human bladder cancer
cells, a recombinant adenovirus vector system containing p21 cDNA, under the
control of cytomegalovirus promoter, was constructed. A control virus containing
p21 in an antisense orientation was used to eliminate potential artifacts caused
by viral toxicity. RESULTS: Human bladder cancer cell lines exhibit variable
endogenous p21 levels which correlate with the in vitro growth status.
Significant, but highly variable increases in the steady-state level of p21 were
detected in p21 adenovirus infected cells. Human bladder cancer cell lines
responded heterogeneously to p21 adenovirus infection. Growth of the WH cell line
was substantially inhibited in a dose and time-course dependent fashion. The
mechanism of p21 growth inhibition was found to be due to G0/G1 arrest and not
the induction of apoptosis. In contrast, p21 adenovirus failed to inhibit the
growth of T24 bladder cancer cells because T24 cells were resistant to viral
infection. The 253J bladder cancer cells exhibited marked sensitivity to
adenovirus; substantial growth inhibition was seen with both sense and antisense
p21 very early in the time course of infection. CONCLUSIONS: We found significant
variation in the basal level of p21 protein expression in several human bladder
cancer cell lines. Increased p21 expression as a result of adenoviral infection
may be a potent growth suppressor in some human bladder cancer because it elicits
cell cycle arrest in G0/G1 stage, but not the induction of apoptosis. Bladder
cancer cells exhibit a wide spectrum of sensitivity to adenoviral infection that
may be caused by the presence of viral receptor heterogeneity. This wide spectrum
of sensitivity has significant basic scientific and clinical implications and
warrants further study.
PMID- 10688045
TI - Detection of loss of heterozygosity in the p53 tumor-suppressor gene with PCR in
the urine of patients with bladder cancer.
AB - PURPOSE: Detection of loss of heterozygosity (LOH) has been described in various
carcinomas on the basis of meticulous molecular techniques. Because of lack of
simple and rapid techniques, LOH has not achieved common use in routine tumor
diagnosis. A recently found variable number of tandem repeats (VNTR) segment in
intron 1 of the p53 gene was described as highly polymorphic and therefore useful
in detecting LOH. We used a rapid technique for detection of LOH in the p53 gene
of patients with transitional cell carcinoma (TCC) of the bladder. The technique
was based on the polymerase chain reaction (PCR) and agarose gel electrophoresis
as described for other carcinomas previously. We evaluated whether TCC screening
and surveillance could be performed detecting LOH in the urinary sediment.
MATERIALS AND METHODS: We investigated 29 patients with TCC of the bladder (pTa
12 patients; pT1 10 patients; pT2 - pT4 seven patients; grade 1 one patient;
grade 2 19 patients; grade 3 nine patients). DNA was prepared by standard methods
from white blood cells, tumor tissue, normal bladder mucosa, and urinary
sediments. The amplification of the VNTR region was performed with PCR. PCR
products were run in parallel lanes on 4.5% agarose gels. RESULTS: Of the 29
patients, 23 (79.3%) were found to have two different alleles ("informative
cases") for the VNTR region. Of the 23 informative cases LOH was detected in the
tumor tissue of 10 patients (43.5%). Referring to the total population 10 of 29
patients (34.4%) revealed LOH. In all patients with LOH in the tumor, LOH was
also detected in the urinary sediment. LOH was not detected in the histologically
benign bladder mucosa. CONCLUSION: We present a simple and rapid technique based
on PCR and agarose gel electrophoresis for the detection of LOH in tumor and
urinary sediment of patients with TCC of the bladder. The ability to detect LOH
not only in tumor tissue but also in urinary sediment offers an attractive
approach for noninvasive diagnosis and surveillance of bladder cancer patients.
PMID- 10688046
TI - Muscle weakness, hyperactivity, and impairment in fear conditioning in tau
deficient mice.
AB - Tau, one of the major neuronal microtubule-associated proteins (MAPs), is
important for neuronal cell morphogenesis and axonal maintenance. Tau is also
known to be a component of the paired helical filaments (PHFs) in Alzheimer's
disease patients. Recently, mutations in the tau gene were found in a hereditary
neurodegenerative disease called frontotemporal dementia and parkinsonism linked
to chromosome 17 (FTDP-17) which exhibits various neurological and
neuropathological characteristics including PHF-like intracellular tau deposit
formation. Currently, the phenotype of the disease is thought to be due to: (1)
the toxicity of mutant tau molecules and and/or; (2) the loss of function of
normal tau molecules in patients' brains. To test the latter hypothesis, we
performed behavioral and neurological tests on tau-deficient mice. Tau-deficient
mice showed muscle weakness in the wire-hanging test, hyperactivity in a novel
environment, and impairment in the contextual fear conditioning. They also had a
tendency to fall more easily in the rod-walking test. These phenotypes parallel
some signs and symptoms of FTDP-17 patients. Our results show that the loss of
tau protein may itself lead to some of the neurological characteristics observed
in FTDP-17 patients.
PMID- 10688047
TI - The deletion polymorphism and Val1000Ile in alpha-2-macroglobulin and Alzheimer
disease in Caribbean Hispanics.
AB - The association between polymorphisms in the alpha-2-macroglobulin (a2m) gene and
Alzheimer's disease remains in doubt because of conflicting results in
independent case-control and family studies. We examined the association between
Alzheimer's disease and alpha2m polymorphisms in Caribbean Hispanic families. The
odds of having the alpha2m deletion/insertion polymorphism was increased 3-fold
for family members with Alzheimer's disease compared to healthy family members,
rising to 5-fold after adjusting for APOE-epsilon4. In contrast, there was no
relationship between the alpha2m Val1000Ile polymorphism and Alzheimer's disease
in these families. The inconsistencies in studies cited above and the modest
association between alpha2m and Alzheimer's disease found in the Caribbean
Hispanic families reported here, suggest that the overall effect of this gene on
susceptibility is small and may be limited to certain populations or families.
PMID- 10688048
TI - The response of growth hormone and prolactin of rats to hypoxia.
AB - Effects of acute and chronic hypoxia on growth hormone (GH) and prolactin (PRL)
of male rats were studied in a simulated hypobaric chambers at altitudes of 5 km
(10.8% O2) and 7 km (7.2% O2), respectively. Acute hypoxia caused decreased
plasma GH and increased pituitary GH content; both pituitary and plasma PRL
contents at 2 h were decreased and plasma PRL level increased at 24 h. Prolonged
exposure of hypoxia (5 km) to 25 days, both pituitary and plasma GH were
obviously lower than control and pituitary PRL levels were decreased but plasma
PRL increased markedly. The data presented suggest that long-term of hypoxia
(10.8% O2) significantly suppresses body growth of rats and inhibits GH release
and/or biosynthesis, which may in part correlate with decreased body weight gain;
high circulating PRL concentration may be of significance in physiological
adaptation to chronic hypoxia.
PMID- 10688049
TI - Preoperative open field behavior predicts levels of neuropathic pain-related
behavior in mice.
AB - Exploratory open field (OF) activity was assessed in seven different mouse
strains and selection lines. We counted the number of beam interruptions made by
three cagemate mice at a time. This assay tests reactivity to aversive stimuli,
anxiety and emotionality. One hindlimb was then totally denervated by transecting
the sciatic and saphenous nerves on one side, and autotomy, a behavior thought to
be related to neuropathic pain, was quantified over 35 days. We report that OF
activity and autotomy are highly variable across different strains/lines. These
results reaffirm the genetic control of these behaviors. We also found that these
behaviors are inversely and significantly correlated. We suggest that common
genetically-determined neural mechanisms may underlie anxiety, emotionality and
neuropathic pain in mice.
PMID- 10688050
TI - Effects of ascorbate in microdialysis perfusion medium on the extracellular basal
concentration of glutamate in rat's striatum.
AB - There are many evidences suggest that ascorbate in the extracellular space can
affect glutamate concentration in the rat's brain. In this report, we studied how
ascorbate in microdialysis perfusion medium affected glutamate level at the
striatum in freely-moving rats. Three perfusion mediums were used: 0, 250, and
400 microM of ascorbate in perfusion medium. The extracellular basal
concentrations of glutamate were determined to be 1.29+/-0.52 microM for the no
ascorbate group, 0.86+/-0.35 microM for the low ascorbate group and 4.76+/-1.48
microM for the high ascorbate group. By using 400 microM of ascorbate in a
perfusion medium, we found that the extracellular basal concentration of
glutamate significantly increased and its in vivo recovery significantly
decreased. This indicated that ascorbate concentration in a perfusion medium was
important and must be carefully considered while using microdialysis technique to
monitor glutamate concentration in vivo.
PMID- 10688051
TI - The difference between electroacupuncture only and electroacupuncture with
manipulation on analgesia in rats.
AB - Plain acupuncture uses manipulation (rotation or varying the depth of insertion
of the needle) to increase its effect. However, in commonly used
electroacupunture (EA), variable manipulations have not been used. This study was
performed to investigate the possibility of an increase in analgesic effect by
adding manipulation to EA. The pain index used was the Tail-Flick latency (TFL)
of the rat, which was lightly anesthetized with thiopental sodium
(intraperitoneally). Four types of manipulation were used. Rotation and varying
the depth of the needle (RN and VN) was employed using two different types of
manipulation during each 20 min stimulation of EA. Each manipulation persisted
for 1 min out of every 5 min (long - duration and long - interval: LDLI) or 12 s
every 1 min (short - duration and short interval: SDSI). EA produced an increase
in TFL; peak value was 49.7+/-12.2% of the pre - EA and occurred immediately
after cessation of 20 min of EA stimulation. Performing RN or VN combined with EA
also increased TFL more than just EA and a greater peak increase in TFL was
observed with a SDSI - RN and SDSI - VN as compared to a LDLI - RN and LDLI - VN
(77.5+/-13.8, 79.2+/-19.8 and 67.3+/-14.0%, 65.6+/-23.7% of the pre - EA,
respectively). These results indicate that manipulation combined with EA produces
a more potent antinociception than when only EA is applied.
PMID- 10688052
TI - Different generators in human temporal-parasylvian cortex account for subdural
laser-evoked potentials, auditory-evoked potentials, and event-related
potentials.
AB - In order to localize cortical areas mediating pain we now report subdural
cortical potentials evoked by auditory stimulation (auditory-evoked potentials -
AEPs) and by cutaneous stimulation with a laser (laser-evoked potentials - LEPs).
Stimulation with the laser evokes a pure pain sensation by selective activation
of nociceptors. LEPs were maximal over the inferior aspect of the central sulcus
and had the same polarity on either side of the sylvian fissure. AEPs were
maximal posterior to the LEP maximum and had opposite polarity on opposite sides
of the sylvian fissure, consistent with the location of a known generator in the
temporal operculum. Auditory P3 (event-related) potentials were maximal over the
temporal base. These findings demonstrate that the LEP generator is not in
secondary somatosensory cortex on the parietal operculum and is different from
the P3 generator.
PMID- 10688053
TI - Magnitude effects of galvanic vestibular stimulation on the trajectory of human
gait.
AB - This study examines the contribution of the vestibular system during different
magnitudes of galvanic vestibular stimulation (GVS) during human walking. Anodal
threshold levels of GVS were determined for right and left sides for each
subject. Seven conditions were tested (no stimulation, left and right anode
stimulation) at one, two and three times threshold. GVS was delivered to the
mastoid processes at first heel contact and continued for the duration of the
trial. All subjects responded by deviating towards the anode while walking. In
addition, the magnitude of deviation increased as the stimulus intensity
increased. Our results demonstrate that the vestibular system is sensitive to GVS
intensity changes and responds by altering the magnitude of the response
accordingly. These data provide a strong argument in support of a significant
role for vestibular information during dynamic tasks.
PMID- 10688054
TI - Bilateral tetrodotoxin blockade of the rat vestibular nuclei substitutes the
natural unconditioned stimulus in taste aversion learning.
AB - The aversive effects of bilateral transient blockade of the lateral vestibular
nucleus caused by tetrodotoxin microinjections were tested using conditioned
taste aversion in the first experiment. Male Wistar rats received tetrodotoxin
injections (10 ng) after drinking a coffee solution (0.5%), either in the lateral
vestibular nucleus (LVN), the parabrachial nucleus or the dopaminergic area A8.
Two days later they drank a cider vinegar solution (3%) not followed by
injections. In a later choice test, only the group receiving the injection in the
lateral vestibular nucleus displayed a coffee aversion. In a second experiment
the role of the peripheral vestibular symptoms induced by LVN inactivation on
substituting the aversive stimulus was explored in the same behavioral task. Rats
anesthetized (Pentobarbital, 25 mg/kg) before tetrodoxin LVN blockade, that did
not show peripheral symptoms, did not develop learned aversions. The coffee
preference ratios did not differ to those animals receiving only anesthesia or
those that remained undisturbed. These results showed that the bilateral blockade
of the vestibular nuclei may induce peripheral vestibular symptoms that that may
substitute the aversive stimulus in taste aversion learning.
PMID- 10688055
TI - Block by extracellular Mg2+ of single human purinergic P2X4 receptor channels
expressed in human embryonic kidney cells.
AB - Single channel properties of human P2X4 receptors expressed in human embryonic
kidney cells have been investigated by outside-out mode patch clamp recordings.
P2X4 channel activity was characterized by very fast kinetics. The current
voltage relationship was strongly non-linear at potentials <-100 mV. A slope
conductance of approximately 9 pS was estimated at the approximately linear part
of the current-voltage relation (>-100 mV). External Mg2+ reversibly decreased
the amplitude of ATP-evoked single channel currents in a concentration-dependent
manner but independent of the membrane potential. Additionally, extracellular
Mg2+ shortened the mean open time whereas the mean closed time was not affected.
Thus, Mg2+ ions are proposed to inhibit the function of human P2X4 receptors by
means of an open-channel block with a Mg2+ binding site at the exterior surface
of the pore.
PMID- 10688056
TI - Amino acid neurotransmitter metabolism in neurones and glia following kainate
injection in rats.
AB - Limbic seizure was induced in rats by intraperitoneal injection of the glutamate
receptor agonist kainic acid. After 14 days [1-13C]glucose and [1,2-13C]acetate
were injected subcutaneously and the rats killed 15 min later. Analysis of brain
extracts was performed using 13C-magnetic resonance spectroscopy and high
performance liquid chromatography. No significant differences between the two
groups of rats were found for label concentration in blood or total metabolite
tissue levels. Only astrocytes are able to utilize acetate as a substrate,
whereas glucose is thought to be metabolized predominantly in the neuronal
tricarboxylic acid cycle. Thus information about neuronal and astrocytic
metabolism could be obtained in the same animal. A significant increase in label
derived from [1-13C]glucose was observed in metabolites such as glutamate, gamma
aminobutyric acid, aspartate, and succinate (all of which are mainly labelled in
neurones). The increased labelling of glutamine in epileptic rats might be due to
transfer of labelled glutamate from neurones to astrocytes. Astrocytic metabolism
of acetate and transfer of glutamine to neurones were not affected. The results
suggest that increased neuronal activity 2 weeks following epileptic seizures
produces increased amino acid turnover in neurones. Changes in astrocytic
metabolism were not detected.
PMID- 10688057
TI - Gabapentin, an antiepileptic drug, improves memory storage in mice.
AB - Male CF-1 mice were tested 48 h after training in a one-trial step-through
inhibitory avoidance task. Immediately post-training i.p. injections of the
antiepileptic drug gabapentin (1-aminomethyl cyclohexaneacetic acid) (GBP; 5, 10,
50, and 100 mg/kg) induced a dose-dependent enhancement of retention performance.
Gabapentin did not affect response latencies in mice not given the footshock on
the training trial, indicating that the actions of GBP on retention were not due
to non-specific proactive effects on response latencies. The effects of GBP (10
mg/kg) were time-dependent, and the administration of GBP (10 mg/kg) 30 min
before training also enhanced retention performance. However, the administration
of GBP (10 mg/kg) 30 min prior to the retention test did not modify retention
latencies of mice that had received either saline or GBP (10 mg/kg) immediately
after training. Altogether, the results suggest that GBP influences retention by
modulating time-dependent processes involved in memory storage, although the
mechanism(s) of this action remain to be established.
PMID- 10688058
TI - Decreased ability of rat temporal hippocampal CA1 region to produce long-term
potentiation.
AB - Tetanic stimulation of Schaffer collaterals in the CA1 region of transverse
slices, taken from the septal (dorsal) part of young rat hippocampus, produced N
Methyl-D-aspartate-dependent long-term potentiation (LTP) of the rising slope of
excitatory postsynaptic potential (mean 38%). Under identical conditions of
stimulation (100 Hz, 1 s) slices taken from the temporal (ventral) third of
hippocampus presented a substantially reduced ability for LTP (mean 5%). The
defect appeared to lie with the induction rather than the maintenance phase of
LTP. These results suggest that a significant functional differentiation at the
local synaptic plasticity level occurs between the two poles of hippocampus,
which together with the substantial differences in their extrinsic connections,
may help explain the reported differential participation of neurons in these
parts of hippocampus during animal memory tests.
PMID- 10688059
TI - The effects of low frequency and two-pulse stimulation protocols on synaptic
transmission in the CA1-subiculum pathway in the anaesthetized rat.
AB - The downregulation of synaptic efficacy is referred to as long-term depression
(LTD). Recent work has shown that a two-pulse stimulation (TPS) protocol is
successful at inducing LTD in vivo in area CA1 of the hippocampus. Here, we
examine the ability of two TPS protocols and two low-frequency stimulation (LFS)
protocols to induce LTD in the projection from hippocampal area CA1 to the
subiculum in the anaesthetized rat. We find no evidence of LTD induction with TPS
or LFS protocols. Instead, with three of the protocols (both TPS protocols and 1
Hz LFS), a late-developing potentiation is observed.
PMID- 10688060
TI - Continuous exposure to dim illumination uncouples temporal patterns of sleep,
body temperature, locomotion and drinking behavior in the rat.
AB - Dissociable circadian rhythms of sleep and body temperature in primates are
thought to be regulated by independent oscillators whereas the uncoupling of
circadian rhythms has not been well described in other mammals. Therefore, we
made simultaneous recordings of non-rapid-eye-movement-sleep (NREMS), rapid-eye
movement-sleep (REMS), brain temperature, intraperitoneal temperature, locomotion
and drinking activity under light-dark (LD) and continuous dim illumination (dim
LL) and analyzed their interrelations. The rhythmic patterns of body temperature,
locomotion and drinking were modified on the 12th circadian day of dim LL, while
the mean body temperature as well as mean occurrence of drinking and locomotor
activities did not change significantly. In contrast, dim LL exposure
significantly increased the total time spent in NREMS during the resting phase of
dim LL and increased REMS episodes during the active phase of dim LL. The diverse
effects of dim LL exposure on the recorded phenomena suggest that temporal
patterns of sleep were the most sensitive to perturbations of lighting and that
differential oscillatory mechanisms may regulate sleep and other circadian
rhythms in the rat.
PMID- 10688061
TI - Food conditioning is impaired in cats deprived of the taste of food in early
life.
AB - Cats were fed by stomach tube during the first 75 days of their life. Thus, they
were deprived of the taste of food and the food reward. The cats were then
trained to find food behind the gate. They acquired this simple response very
slowly and during the first weeks of training they often refused to eat the food
reward. Moreover, they extinguished the response poorly. We conclude that the
deprived cats did not originally perceive the food reward as attractive, but they
were able to learn this, and they were poorly able to form both excitatory and
inhibitory food conditioned connections.
PMID- 10688062
TI - Bcl-w expression is increased in brain regions affected by focal cerebral
ischemia in the rat.
AB - Proteins of the bcl-2 family are important regulators of apoptosis in many
tissues of the embryo and adult and may play a role in cell death following
stroke. The recently isolated bcl-w gene encodes a pro-survival member of the bcl
2 family, which is widely expressed. However, it is not known whether bcl-w plays
a role in determining cell survival after cerebral ischemia. Using Western blot
analysis and immunocytochemistry, regional bcl-w protein expression was studied
in rat brain 2, 6, 24 and 72 h following 20 min temporary middle cerebral artery
occlusion (MCAO). Focal cerebral ischemia increased bcl-w protein expression
within the caudate putamen and parietal cortex, as well as causing milder
increases within frontal cortex. Immunocytochemically bcl-w was expressed within
neurons (frontal and parietal cortex) and glia (caudate putamen) 24 h after MCAO.
These data suggest that bcl-w could play a role in determining cell survival
after cerebral ischemia.
PMID- 10688063
TI - The practice of radiology is changing rapidly in many areas.
PMID- 10688064
TI - CT diagnosis of acute flank pain from urolithiasis.
AB - The use of noncontrast helical CT (NHCT) to assess patients with acute flank pain
and hematuria for potential urinary tract stone disease was first reported in
1995. After several years of experience with the technique, sensitivity and
specificity of NHCT has proven to be better than intravenous urography for
evaluating ureteral stones. NHCT imaging findings for urinary calculi and the
differential diagnosis are discussed in this article. Various extraurinary
diseases found while using NHCT in searching for stone disease are addressed and
illustrated. As experience with the use of NHCT has increased, clinicians have
broadened the indications for this technique, which has a lower charge than
standard CT, beyond the specific evaluation of urinary colic. This indication
creep has increased the number of NHCT examinations ordered. It has also reduced
the rate of stone positivity and increased the diagnostic yield for extraurinary
disease.
PMID- 10688065
TI - Targeted helical CT of the acute abdomen: appendicitis, diverticulitis, and small
bowel obstruction.
AB - CT, especially helical CT, provides a fast and reliable modality for evaluation
of the patient presenting with acute abdominal pain. Helical CT can provide an
accurate diagnosis in the majority of patients and has found great utility in the
evaluation of acute gastrointestinal emergencies, including acute appendicitis,
diverticulitis, and small bowel obstruction. This article reviews proper helical
CT technique, diagnostic imaging findings, and pitfalls of interpretation in
evaluation of these acute abdominal disorders.
PMID- 10688066
TI - CT and MR diagnoses of intestinal ischemia.
AB - CT and MR imaging have an important role in establishing the diagnosis of
mesenteric ischemia. However, without specific signs such as thromboembolism in
the mesenteric vessel, intramural or portal venous gas, and the absence of bowel
wall enhancement, mesenteric ischemia can be confused with inflammatory or
neoplastic gastrointestinal diseases. Arterial or venous occlusion or low-flow
state are the main direct causes of mesenteric ischemia. Delayed diagnosis in
equivocal cases can be avoided through an understanding of the
patholophysiological aspects of mesenteric ischemia as they occur in a variety of
other conditions, including: thromboembolism, bowel obstruction, neoplasm,
vasculitis, inflammatory diseases, trauma, and drug or radiation therapy.
PMID- 10688067
TI - Acute cholecystitis: CT findings.
AB - Some patients with acute cholecystitis may have symptoms suggestive of an abscess
or other intra-abdominal inflammation and, therefore, may be referred for a CT of
the abdomen. This report reviews the pathophysiology, clinical presentation, and
CT findings of acute cholecystitis (gallstones, wall thickening, distention,
pericholecystic fluid, and pericholecystic stranding). Pitfalls and complications
of the diagnosis are discussed. Those scenarios where CT may prove superior to
ultrasound or hepatobiliary scintigraphy are highlighted.
PMID- 10688068
TI - Assessment of acute abdominal pain in the pregnant patient.
AB - The request to image a pregnant patient with abdominal pain often leads to
concern and frustration for the referring clinician as well as the radiologist.
In this report we will review the basic principles of radiation safety when
imaging the pregnant woman, consider the diagnostic possibilities for the causes
of abdominopelvic pain, and discuss the available imaging modalities to provide a
basis for tailoring an imaging plan to the individual patient.
PMID- 10688069
TI - Acute female pelvic pain: ultrasound evaluation.
AB - Ultrasound has become a valuable primary imaging tool in the assessment of acute
pelvic pain in women, both for diagnosis and for assessment of complications.
Although ultrasound is an established imaging tool for gynecologic diseases, it
is also a useful modality for assessing nongynecologic disorders that cause acute
pelvic pain, such as diverticulitis and urinary tract calculi. These are
important differential diagnoses in women with acute pelvic pain, and sonologists
are not always expert in their diagnosis. This article reviews the gamut of
conditions that can cause acute pelvic pain in women. The usual gynecologic
causes are included, such as ectopic pregnancy, but also considered are
conditions such as diverticulitis, appendicitis, and incarcerated hernia, which
are important differential considerations.
PMID- 10688070
TI - Adjuvant chemotherapy for T3 prostate cancer: not ready for prime time.
PMID- 10688071
TI - Intravesical therapy for bladder cancer.
PMID- 10688072
TI - Current evidence for the role of combined androgen suppression and radiation in
the treatment of adenocarcinoma of the prostate.
PMID- 10688073
TI - Comparison of expressed prostatic secretions with urine after prostatic massage-
a means to diagnose chronic prostatitis/inflammatory chronic pelvic pain
syndrome.
AB - OBJECTIVES: To compare the analysis of urine after prostatic massage (VB3) with
expressed prostatic secretions (EPS) to assess the significance of leukocyte
analysis in VB3 and to give a first hint of the diagnosis of inflammatory chronic
pelvic pain syndrome (CPPS) when EPS cannot be obtained. METHODS: Three hundred
twenty-eight men (mean age 38 years, range 18 to 70) with expressible prostatic
secretions were investigated. EPS were stained using the Papanicolaou stain and
analyzed for leukocytes per high power field (HPF) (x1000). Additionally,
identical aliquots of first voided urine (VB1), midstream urine (VB2), and VB3
were centrifuged, stained (Papanicolaou), and analyzed for leukocytes (x400).
Patients with increased numbers of leukocytes in VB1 and VB2 (2 or more per x400)
were excluded. For statistical analysis, Spearman's correlation coefficient for
nonparametric tests was used. RESULTS: Of 180 men with less than 10 leukocytes
per HPF in EPS, 178 (98.9%) had less than 10 leukocytes per view field in VB3. In
148 men with 10 or more leukocytes per HPF in EPS, 136 (91.9%) also had elevated
leukocyte counts in VB3. The presence of elevated leukocytes in VB3 predicted the
presence of increased leukocytes in EPS with a high certainty: 91.9% sensitivity,
98.9% specificity, and 95.7% accuracy, with a positive and negative predictive
value of 98.6% and 93.7%, respectively. CONCLUSIONS: We conclude that the
determination of leukocytes in VB3 is a feasible and reliable method compared
with the analysis of EPS. However, although this association does not directly
prove the significance of VB3 in those patients from whom no EPS can be obtained,
we suggest this method be taken into account as an indirect indicator in the
diagnosis of inflammation.
PMID- 10688074
TI - Laparoscopic enterocystoplasty.
AB - OBJECTIVES: To report the initial clinical experience with laparoscopic
augmentation enterocystoplasty using the ileum, sigmoid, or right colon. METHODS:
Three patients with functionally reduced bladder capacities due to neurogenic
causes underwent laparoscopic enterocystoplasty: ileocystoplasty (n = 1),
sigmoidocystoplasty (n = 1), and cystoplasty with cecum and proximal ascending
colon (n = 1). In the last patient, a continent, catheterizable, ileal conduit
with an umbilical stoma was also created. In all patients, bowel reanastomosis
was performed by exteriorizing the bowel loop outside the abdomen through a 2-cm
extension of the umbilical port site. Creation of a large cystotomy, mobilization
of the appropriate bowel segment, and the circumferential enterovesical
anastomosis were all performed intracorporeally by laparoscopic techniques.
RESULTS: The operative times were 5.3, 8, and 7 hours. All three laparoscopic
enterovesical anastomoses were watertight, without postoperative urinary
extravasation. The hospital stay was 7, 5, and 4 days. CONCLUSIONS: Laparoscopic
enterocystoplasty is feasible, safe, and efficacious and appears to be an
attractive alternative to open enterocystoplasty. Various bowel segments can be
used as with open surgery, including creation of a continent, catheterizable
stoma. Although further technical refinements will undoubtedly occur, even at
this early stage, it is clear that the technical steps of an enterocystoplasty
can be satisfactorily and effectively performed laparoscopically.
PMID- 10688075
TI - Double-blind randomized comparison of single-dose ciprofloxacin versus
intravenous cefazolin in patients undergoing outpatient endourologic surgery.
AB - OBJECTIVES: To compare the efficacy of single-dose oral ciprofloxacin with
intravenous cefazolin as a prophylactic agent in patients undergoing outpatient
endourologic surgery. METHODS: One hundred patients were enrolled in a double
blind, randomized study to receive either ciprofloxacin (500 mg) or cefazolin (1
g) before surgery. A postoperative clinical evaluation and urine cultures were
performed 5 to 10 days after surgery. Patients undergoing ureteral stent
insertion or exchange, ureteroscopy, bladder biopsy, retrograde pyelography,
collagen injection, and internal urethrotomy were included. RESULTS:
Postoperative urinary tract infection occurred in 7 (9.1%) of 77 patients,
including 3 (8.1%) of 37 and 4 (10.0%) of 40 of those who received ciprofloxacin
and cefazolin, respectively (P = 0.77). There were no episodes of sepsis, and no
patient with infection required hospitalization. The total cost associated with
the administration of prophylactic antibiotics in the study population was $3657
less in those 50 patients who received ciprofloxacin than in the 50 patients who
received cefazolin. CONCLUSIONS: A single oral dose of ciprofloxacin in patients
undergoing outpatient endourologic surgery was equally effective as cefazolin in
preventing postoperative urinary tract infection, but was associated with
markedly lower overall costs.
PMID- 10688076
TI - Detecting urethral and prostatic inflammation in patients with chronic
prostatitis.
AB - OBJECTIVES: Diagnosis of urethral and prostatic inflammation can represent a
challenge. We compare the accuracy of diagnostic methods for detecting
inflammation in lower urinary specimens/samples. METHODS: A standardized protocol
was used to evaluate urethral smear, first-void urine (VB1), midstream urine
(VB2), expressed prostatic secretions (EPS), and postmassage urine (VB3) in
urologic patients with no symptoms or signs of urethritis who were attending our
prostatitis clinic. RESULTS: Of 235 subjects, 60 (26%) had leukocytes detected by
the Gram-stained urethral smear, 44 (18%) by the VB1, and only 14 (6%) by the
VB2. Compared with the urethral swab, VB1 had 0% to 22% sensitivity and 81% to
98% specificity, and VB2 had 8% to 11% sensitivity. Of 83 subjects with prostatic
inflammation, the EPS detected 63 (76%) and the VB3 detected 68 (82%).
CONCLUSIONS: VB1 or VB2 examinations had low sensitivity for detecting urethral
inflammation. Examining both the EPS and VB3 proved best for detecting prostatic
fluid inflammation. Combining the urethral smear with lower urinary tract
localization ("four-glass test") represents an optimal approach for detecting
urethral and prostatic inflammation.
PMID- 10688077
TI - Management of shotgun injuries to the pelvis and lower genitourinary system.
AB - OBJECTIVES: Shotgun injuries are rare, with the extent of injury best determined
at time of surgical exploration. There are no defined workup or management
guidelines for patients with shotgun injuries to the genitourinary system.
Injuries are usually treated on an individual basis. This study was conducted to
determine the management and extent of genitourinary tract injuries in 10
patients with shotgun injuries to the pelvis during a 6-year interval. METHODS:
Between September 1990 and December 1996, 140 patients were treated for firearm
injuries to the lower genitourinary tract, of which 10 were secondary to shotgun
blasts. We performed a retrospective hospital and clinic chart review and
telephone interview to assess organs injured, initial treatment, follow-up
surgeries, mortality, and erectile function. RESULTS: Mean patient age was 20
years at the time of the injury. The mean follow-up was 4 years (range 1 to 7).
Two patients died, both with major vascular injuries, one in the operating room
and the other 1 week later from sepsis. Eight patients underwent radiographic
examinations (1 intravenous urogram and 7 urethrocystograms). The bladder was
injured in 5 patients, 2 with concomitant complete posterior urethral
transection. Of the 5 patients without bladder injury, one had an incomplete
penile urethral injury and one had a complete bulbar urethral transection. The
initial management consisted of repairing nongenitourinary injuries in 8 cases
(80%), most commonly involving injuries to the rectum and small bowel. All
patients were treated operatively, including 8 who required laparotomy and 4 who
required suprapubic cystotomy. A total of four urethral injuries were noted.
Subsequent reconstructive surgeries included two urethroplasties and one
permanent supravesical diversion for 3 patients with extensive urethral loss.
Erectile dysfunction was present in 3 of 6 patients available for telephone
interview. CONCLUSIONS: Shotgun injuries involving the lower genitourinary tract
are associated with significant soft tissue injury and morbidity. Death usually
results from major associated vascular injuries. All hemodynamically stable
patients should undergo retrograde urethrograms and cystograms to evaluate
possible urethral and bladder injuries. Open primary repair should be attempted
for distal urethral, testicular, and corporal injuries. Delayed repair with
staged urethral reconstruction should be reserved for patients with extensive
loss of urethral tissue. Impotence is common in patients with extensive perineal
injuries.
PMID- 10688078
TI - Ureteroscopic endopyelotomy in the treatment of patients with ureteropelvic
junction obstruction.
AB - OBJECTIVES: To investigate the effectiveness and morbidity of ureteroscopic
endopyelotomy in adults with ureteropelvic junction (UPJ) obstruction. METHODS:
Twenty-two patients (13 women, 9 men) with a mean age of 44 years (range 18 to
86) underwent retrograde ureteroscopic endopyelotomy in the treatment of primary
(n = 18) or secondary (n = 4) UPJ obstruction. All procedures were performed
using a 6F to 8.5F semirigid ureteroscope with either a 3F electrocautery probe
(n = 16) or a 365-microm holmium laser fiber (n = 6). Postoperatively, a tapered
14/7F endoureterotomy stent (n = 11) or standard 7F to 8F double pigtail stent (n
= 11) was left in place for 6 to 7 weeks. Radiographic follow-up was obtained
using intravenous urography or renal scintigraphy. RESULTS: With a median follow
up of 20.5 months, the success rate was 82% (18 of 22 patients). Follow-up of at
least 6 and 12 months was available in 21 (95%) and 17 (77%) of 22 patients,
respectively. The mean operative duration was 63 minutes, and all but 1 patient
was hospitalized for less than 24 hours. No bleeding complications or other
serious morbidity were encountered. No difference in treatment outcome was found
on the basis of the size of the stent placed postoperatively, the incision type
(cautery versus laser), or the etiology of the obstruction. CONCLUSIONS:
Ureteroscopic endopyelotomy is an effective, minimally invasive treatment option
for patients with primary or secondary UPJ obstruction.
PMID- 10688079
TI - Mechanical percussion inversion can result in relocation of lower pole stone
fragments after shock wave lithotripsy.
AB - OBJECTIVES: To determine whether mechanical percussion combined with inversion
(MPI) therapy and forced diuresis can move stone fragments out of the lower pole
of the kidney. METHODS: Twelve patients with lower pole residual stone fragments
at least 2 weeks after shock wave lithotripsy were treated using the following
protocol. Eleven patients received 20 mg of furosemide before MPI therapy.
Patients were treated in the prone Trendelenberg position on a pivoting stretcher
and given 10 minutes of percussion over the flank using a mechanical chest
physiotherapy percussor. Stone location was documented with plain abdominal
radiographs before, immediately after, and 2 weeks following MPI therapy. Voided
urine was strained immediately after MPI therapy and throughout the study period.
RESULTS: Abdominal radiographs before and after treatment demonstrated movement
of fragments out of the lower pole in 11 patients. In 8 patients, the lower pole
appeared entirely clear of fragments on the immediate post-treatment film. Four
patients passed stone fragments in their first voided urine. Ten patients passed
stone fragments during the 2-week follow-up period. CONCLUSIONS: MPI therapy
combined with diuresis can effectively mobilize stone fragments out of the lower
pole calyces and appears to aid in the passage of fragments.
PMID- 10688080
TI - Short-term complications of pubovaginal sling procedure for genuine stress
incontinence in women.
AB - OBJECTIVES: To evaluate the complication rate intraoperatively and within the
first 30 postoperative days of the pubovaginal sling procedure. METHODS: From
January 1992 to September 1996, we prospectively analyzed 90 women with type II
and III genuine stress incontinence (age 38 to 84 years, average Valsalva leak
point pressure 57.5 cm H2O) who underwent the pubovaginal sling procedure at our
institute. Sixty percent of patients had no previous surgical treatment for their
incontinence. Thirty-three percent of our patients have significant comorbidity
(chronic obstructive lung disease, diabetes, coronary artery disease, peripheral
vascular disease). RESULTS: The complication rate within the first 30
postoperative days was 19%, which included pneumonia (1.1%), deep venous
thrombosis (1.1%), urinary retention (3.3%), wound infection (7.7%),
intraoperative bladder laceration (3.3%), urinary tract infection (1.1%), and
superficial thrombophlebitis (1.1%). A similar complication rate was noted among
our patients with no previous surgical treatment for their incontinence.
CONCLUSIONS: The complication rate of our prospective series of pubovaginal sling
procedures was comparable to that of the other surgical procedures for genuine
stress incontinence reported in the literature. We conclude that even though the
pubovaginal sling procedure is a relatively complex surgery, in view of its
satisfactory long-term success rate reported in the recent literature,
pubovaginal sling procedure should also be considered a primary surgical
treatment for genuine stress incontinence in a selected population of women.
PMID- 10688081
TI - Distal ureteral regeneration after radical transurethral bladder tumor resection.
AB - OBJECTIVES: Radical, full-thickness resection of the bladder wall and overlying
bladder tumor is a management option in highly selected patients with muscle
invasive bladder cancer. The consequences of iatrogenic ureteral injury in
patients whose tumor involves the ureteral orifice and intramural ureter have not
been reported. This report details an experience with 4 patients who underwent
full-thickness resection of the hemi-trigone and distal ureter as treatment for
muscle-invasive bladder tumors. METHODS: Between August 1995 and February 1999, 4
patients with T2 transitional cell cancer involving the bladder base and hemi
trigone underwent radical transurethral resection of bladder tumor (TURBT),
defined as resection of the tumor and bladder wall into the perivesical fat as
primary tumor management. Six weeks later, the patients underwent a restaging
TURBT to assess the pathologic response and status of the distal ureter. Patients
were then followed up at regular intervals for the development of hydronephrosis
and/or upper tract complications. RESULTS: Regeneration of the distal ureter was
noted at 6 weeks in all patients. At a mean follow-up of 24 months, no patient
had developed evidence of upper tract deterioration. All patients remained
without evidence of tumor recurrence. CONCLUSIONS: This experience suggests that
iatrogenic injury to the distal ureter during radical transurethral resection of
tumor involving the hemi-trigone does not result in long-term distal ureteral
damage. Involvement of the hemi-trigone by tumor does not appear to be a
contraindication to radical TURBT.
PMID- 10688082
TI - Modified Pereyra bladder neck suspension in patients with intrinsic sphincter
deficiency and bladder neck hypermobility: patient satisfaction with a mean
follow-up of 4 years.
AB - OBJECTIVES: To determine the long-term success rate for the modified Pereyra
bladder neck suspension and to identify preoperative characteristics that create
differences in surgical outcome. We attempted retrospectively to separate those
patients with what we now recognize was significant intrinsic sphincter
deficiency (ISD) before routine use of Valsalva leak point pressures (VLPPs) was
available. METHODS: The charts and videourodynamic reports of 208 patients who
underwent a modified Pereyra bladder neck suspension from June 1988 to June 1996
were reviewed, and survey questionnaires were mailed to all patients. All
videourodynamic study reports and charts were reviewed to identify those with
what we now recognize was significant ISD and compare them with a group that we
believed had more pure descent problems. RESULTS: A total of 135 patients or 65%
of the population responded. The mean time after surgery was 4.14 years. At the
follow-up survey, 14% reported no leakage at all, 42% reported very little or
mild leakage, 38% reported moderate leakage, and 6% reported severe leakage.
Fifty-three percent of patients continued to wear pads. Seventy-nine percent
reported improvement in their leakage compared with the preoperative state, and
69% were satisfied with the results. When patients with preoperative ISD were
compared with patients with pure bladder neck hypermobility, the ISD group had
more leakage and less improvement after surgery than patients with bladder neck
hypermobility. CONCLUSIONS: With an average follow-up of greater than 4 years,
most women continued to leak with symptoms of stress urinary incontinence. Even
though 79% reported improvement over their preoperative condition and 69% were
satisfied, the results were disappointing. Patients with significant ISD had a
worse outcome (2.6% dry) than patients with pure bladder neck hypermobility (20%
dry). Given the above data, significant ISD is a contraindication for a modified
Pereyra transvaginal needle suspension, and these data cast further doubt on the
ability of the modified Pereyra needle suspension to consistently cure even
anatomic incontinence.
PMID- 10688083
TI - Comparison of the monoclonal UBC-ELISA test and the NMP22 ELISA test for the
detection of urothelial cell carcinoma of the bladder.
AB - OBJECTIVES: To compare the diagnostic value of two enzyme-linked immunosorbent
assay (ELISA) tests, the nuclear matrix protein 22 (NMP22) test and a newly
developed urinary bladder cancer (UBC) test, in patients having symptoms
suggestive of urothelial cell carcinoma (UCC) and patients under follow-up after
transurethral resection (TUR). METHODS: Two hundred forty patients with a mean
age of 65.8 years (range 22 to 92) were included in this retrospective study. The
tests were performed on previously frozen urine samples. Eighty-one patients had
symptoms suggestive of bladder cancer and 159 patients were being followed up
after complete TUR of UCC. Voided urine was evaluated by the NMP22 test and the
monoclonal UBC-ELISA test, which traces cytokeratins 8 and 18. All patients
underwent subsequent cystoscopy and biopsy evaluation of any suspicious lesion.
The cutoff levels for bladder cancer positivity were 10 U/mL for the NMP22 test
and 12 microg/L for the UBC test. RESULTS: In the 54 patients with histologically
proved UCC, the NMP22 test had a sensitivity of 55.5% and the UBC test a
sensitivity of 64.8%. According to the histologic stages, the sensitivity of
NMP22 was 51.7% in pTa tumors, 46.1% in pT1, and 70% in pT2 or higher tumors; the
sensitivity of UBC was 62.1% in pTa, 53.8% in pT1, and 80% in pT2 or higher
tumors. For histologic grades 1 to 3, the sensitivity was 50%, 50%, and 68.7% for
NMP22 and 66.6%, 60%, and 68.7% for UBC, respectively. The specificity was 79%
and 92% for NMP22 and UBC, respectively. CONCLUSIONS: The monoclonal UBC-ELISA
test is superior to the NMP22 test in both sensitivity and specificity.
Nevertheless, neither test can replace cystoscopy.
PMID- 10688084
TI - Urinary NMP22 and renal cell carcinoma.
AB - OBJECTIVES: To demonstrate the incidence of positive urinary nuclear matrix
protein 22 (NMP22) values associated with renal cell carcinoma (RCC) of the
kidney. Currently, urinary NMP22 is used to detect recurrent transitional cell
carcinoma of the bladder. METHODS: From May 1997 to March 1998, urinary NMP22
values were obtained from 65 patients who had undergone either computed
tomography scanning of the abdomen or renal ultrasound. Of the 65, 32 presented
with solid renal masses. These patients underwent radical or partial nephrectomy;
subsequent pathologic examination revealed that 30 had RCC. Two patients had
oncocytomas. The remaining 33 patients presented with blunt abdominal trauma or
abdominal pain or for follow-up for a urologic problem (a kidney stone or benign
renal cyst). These patients had no evidence of renal malignancy on imaging and
were used as controls. RESULTS: The urinary NMP22 values of patients with RCC
were significantly higher than the values found in the control group (13.69 +/-
8.40 U/mL versus 3.03 +/- 2.70 U/mL, P <0.0078). Of the 30 patients with RCC, 12
(40%) had positive urinary NMP22 values of 10 U/mL or above. Chi-square analysis
revealed a significant difference between the NMP22 values of the two groups (P
<0.005). There were two false-positive NMP22 values in the 35 control patients.
CONCLUSIONS: Urinary NMP22 values used to detect transitional cell carcinoma in
individuals with previously diagnosed bladder cancer should be more broadly
evaluated, since elevations have also been found to occur in RCC of the kidney.
This finding may result in an increase in the incidental discovery of RCC.
Future, more specific, NMP assays may hold promise for the detection of RCC.
PMID- 10688085
TI - Clinical outcome 1 year after transurethral vaporization and resection of the
prostate.
AB - OBJECTIVES: To evaluate the 1-year safety and effectiveness of transurethral
vaporization of the prostate (TUVP) compared with transurethral resection of the
prostate (TURP) in alleviating outflow obstruction. METHODS: Two experienced
surgeons performed 26 TUVPs and 28 TURPs. The intraoperative blood loss was
measured by photometry and fluid absorption by the ethanol method. The treatments
were evaluated by means of the International Prostate Symptom Score (IPSS),
quality-of-life score, transrectal ultrasound, prostate-specific antigen level,
urinary flow rate, and postvoid residual urine volume. RESULTS: After TUVP, the
median IPSS decreased from 22 to 4.5 and the quality-of-life score from 4.5 to
1.5. The corresponding data for TURP were from 25 to 5.5 and from 4.0 to 1.0. The
median urinary flow rate increased from 4 to 10 mL/s after TUVP and from 2 to 11
mL/s after TURP. The postvoid residual urine volume decreased to 35% (TUVP) and
15% (TURP) of the preoperative volume. The blood loss was larger during TURP (P
<0.04), but complications during follow-up were more frequent after TUVP (P
<0.02). Patients with fluid absorption during surgery had a lower quality-of-life
score at follow-up (P <0.02) and tended to have a smaller reduction in prostate
size (to 79%) than those without absorption (to 67% of baseline). CONCLUSIONS:
TUVP and TURP were both effective in alleviating outflow obstruction, but the
outcome appeared to be slightly better for TURP.
PMID- 10688086
TI - Incidence of acute myocardial infarction and cause-specific mortality after
transurethral treatments of prostatic hypertrophy.
AB - OBJECTIVES: Transurethral resection of the prostate (TURP) is associated with a
higher long-term mortality than open prostatectomy which has been ascribed to a
higher incidence of acute myocardial infarction (AMI). To assess the possible
excess risk associated with TURP, we studied the incidence of AMI and the cause
specific mortality in patients treated with TURP and transurethral microwave
thermotherapy (TUMT). METHODS: Patients treated for benign prostatic hypertrophy
at a university hospital (888 patients with TURP and 478 with TUMT) were
monitored during an average follow-up period of 3.9 years. The incidence of AMI
and the causes of death were compared with those in the general population.
RESULTS: Both treatments were followed by a higher incidence of AMI than in the
general population, in particular from 2 years or more after treatment
(standardized morbidity ratio 1.50, 95% confidence interval [CI] 1.14 to 1.93).
The long-term mortality from all causes was increased in patients younger than 75
years of age when undergoing any of the treatments (standardized mortality ratio
[SMR] 1.16, 95% CI 0.97 to 1.39), in particular, death from cardiovascular
diseases (SMR 1.25, 95% CI 0.95 to 1.60) and tumors (SMR 1.54, 95% CI 1.14 to
2.03). CONCLUSIONS: The similarity of the results for TURP and TUMT suggests that
the prostatic enlargement rather than the treatment is associated with
cardiovascular disease.
PMID- 10688087
TI - Role of Viagra after radical prostatectomy.
AB - OBJECTIVES: To determine whether the response to sildenafil citrate (Viagra) in
patients with erectile dysfunction after radical prostatectomy was influenced by
the presence or absence of neurovascular bundles, the interval from surgery to
the initiation of drug therapy, and the dose of the drug. METHODS: Baseline and
follow-up data from 91 patients presenting with erectile dysfunction after
radical prostatectomy were obtained. The patients were stratified according to
the type of nerve-sparing (NS) procedure: bilateral NS, unilateral NS, and non
NS. They were interviewed using the Cleveland Clinic Post Prostatectomy (CCPP)
questionnaire and the International Index of Erectile Function (IIEF)
questionnaire. RESULTS: The presence or absence of the neurovascular bundles
influenced the ability to achieve vaginal intercourse. In the patients who had
undergone bilateral NS, 71.7% (38 of 53) responded; in those with unilateral NS,
50% (6 of 12) responded; and in those with non-NS, 15.4% (4 of 26) responded. The
IIEF questionnaire confirmed the quality of the positive responses, with
significant improvements in response to question 3 (frequency of penetration),
question 4 (frequency of maintenance of erection), and question 7 (satisfaction
with intercourse). The magnitude of improvement in responses was higher in the
bilateral NS group than in the unilateral NS and non-NS groups (P <0.05). When
the data of the 48 positive responders were analyzed, no difference in the
response rate was found when the interval from surgery to drug therapy was
stratified by the following three intervals: 0 to 6 months (44%), 6 to 12 months
(55%), and greater than 12 months (53%). Of the positive responders, 14 (29.1%)
required the 50-mg dose, and 34 (70.9%) required the 100-mg dose. The most common
side effects were transient headaches (28.6%), flushing (21.9%), dizziness
(8.8%), dyspepsia (6.5%), and nasal congestion (5.4%), with an increase in the
incidence of headaches seen at the higher dose (P = 0.04). CONCLUSIONS:
Successful treatment of erectile dysfunction with sildenafil citrate after
radical prostatectomy depends on the presence of the neurovascular bundles. Our
data suggest that the response to sildenafil is not related to the interval
between the surgery and initiation of drug therapy but is related to the dose.
PMID- 10688088
TI - Prostate cancer biochemical recurrence stage for stage is more frequent among
African-American than white men with locally advanced but not organ-confined
disease.
AB - OBJECTIVES: To determine whether outcome differences between African-American men
(AAM) and white men with prostate cancer (PCa) will still be present if we
control for stage in a large cohort of men. It is well established that AAM have
a worse outcome from PCa than white men. METHODS: We examined 848 consecutive
patients who underwent radical prostatectomy at Wayne State University, Karmanos
Cancer Institute, between 1991 and 1995. The mean follow-up was 34 months (range
1.5 to 75). We included men with Gleason score 7 (4 + 3) with those men with
Gleason score 8 to 10 for racial/ethnic comparisons. RESULTS: AAM and white men
diagnosed with organ-confined PCa demonstrated similar prostate-specific antigen
(PSA) levels, Gleason grade, and biochemical recurrence. However, AAM diagnosed
with non-organ-confined disease demonstrated higher PSA levels and a higher
incidence of recurrence than did white men with non-organ-confined disease. There
was a trend toward AAM having a greater proportion of high-grade lesions than
white men when PCa was not organ confined. The evidence suggests that the
difference in recurrence among AAM versus white men is based on pretreatment PSA,
grade, extracapsular extension, and positive surgical margins. Seminal vesicle
invasion predicted a worse prognosis equally for both AAM and white men.
CONCLUSIONS: A difference in biochemical recurrence was not detected between AAM
and white men with organ-confined PCa after radical prostatectomy. PSA was higher
in AAM than in white men with pathologically locally advanced PCa, and the
biochemical recurrence was greater. AAM had a greater percentage of high Gleason
grade lesions compared with white men, and this difference approached statistical
significance. We hypothesize that AAM have a more rapid growth rate of PCa, which
may be responsible for these clinical findings. Further investigations of the
biology of PCa are needed to understand these findings.
PMID- 10688089
TI - Novel image analysis of corpus cavernous tissue in impotent men.
AB - OBJECTIVES: To objectively evaluate the contents of corpus cavernous tissue in
impotent men using an automated novel image analysis system. METHODS: Thirty
three impotent men and 2 normal potent men (controls) underwent corpus cavernous
biopsies. The procedures were performed using a Biopty gun under local
anesthesia. The obtained specimens were stained with Masson's trichome technique,
and the collagen fiber contents were evaluated by a computerized morphometric
analysis method. In addition, we estimated the intraobserver and interobserver
reliability of this automated image analysis system. RESULTS: No major
complication was noted during or after the biopsies. Of the 33 impotent patients,
3 were diagnosed as having psychogenic, 11 as having arteriogenic, 13 as having
venogenic, 1 as having neurogenic, and 5 as having idiopathic impotence. The
collagen fiber percentages in the 35 men were as follows: normal potent: 48.2% +/
1.4%, psychogenic 55.2% +/- 11.6%, arteriogenic 73.2% +/- 4.4%, venogenic 66.5%
+/- 4.2%, neurogenic 76.9%, and idiopathic 77.4% +/- 4.2%. Significant
differences were found between the normal potent and arteriogenic groups (P
<0.05) and between the normal potent and idiopathic groups (P <0.05). Patients
older than 60 years had a higher collagen fiber content (70.4% +/- 3.7%) than
those younger than 50 years old (58.6% +/- 5.2%). The interobserver and
intraobserver variances were both negligible for this automated image analysis
system. This method significantly reduced the amount of variation introduced by
the intra-rater reliability of a technician compared with the manual method.
CONCLUSIONS: The present automated image analysis system is believed to be a
reliable, accurate quantitative measurement tool for studies of penile tissue.
Cavernous biopsy is a rapid, safe, and representative modality to study penile
disease. An increase in cavernous collagen fibers (or corporal fibrosis) is
considered an important factor in impaired erectile function.
PMID- 10688090
TI - Clinical study of SS-cream in patients with lifelong premature ejaculation.
AB - OBJECTIVES: To investigate the clinical efficacy of SS-cream, the topical agent
made from the extracts of nine natural products for the treatment of premature
ejaculation, we performed a double-blind, randomized, placebo-controlled Phase
III clinical study of patients with lifelong premature ejaculation in three
medical centers. METHODS: One hundred six patients (mean age 38.7 +/- 0.61 years)
completed this study. The ejaculatory latency measured by stopwatch and sexual
satisfaction ratio of both partner and patient were investigated twice in the
screening period and once after each treatment (1 placebo 0.20 g and 5 SS-cream
0.20 g for a total of six treatments). Patients were instructed to apply the
cream on the glans penis 1 hour before sexual intercourse in a double-blind
randomized fashion. Clinical efficacy was compared with the prolongation of
ejaculatory latency and improvement of the sexual satisfaction ratio before and
after each treatment. RESULTS: In the screening period, the mean ejaculatory
latency was assessed at 1.37 +/- 0.12 minutes, and neither the patients nor their
partners were satisfied with their sexual lives. After treatment, the mean
ejaculatory latency was prolonged to 2.45 +/- 0.29 minutes in the placebo group
and 10.92 +/- 0.95 minutes in the SS-cream group. The clinical efficacy of
placebo and SS-cream as judged by an ejaculatory latency time prolonged more than
2 minutes was 15.09% and 79.81%, respectively. The improvement of sexual
satisfaction to a grade higher than effective was 19.81% and 82.19%,
respectively, for placebo and SS-cream. Of 530 trials of SS-cream, 98 (18.49%)
resulted in a sense of mild local burning and mild pain. No adverse effect on
sexual function or partner and no systemic side effects were observed.
CONCLUSIONS: According to these results, SS-cream is effective and safe in the
treatment of premature ejaculation, with mild local side effects.
PMID- 10688091
TI - Magnetic resonance imaging and magnetic resonance angiography before
postchemotherapy retroperitoneal lymph node dissection.
AB - OBJECTIVES: Retroperitoneal lymph node dissection (RPLND) after primary
chemotherapy is an accepted therapeutic approach for metastatic nonseminomatous
germ cell testicular cancer. Because of the intense desmoplastic reaction and
adherence to venous and arterial walls, accurate imaging of the retroperitoneal
vasculature and its relation to residual tumor is essential. We report our
experience with magnetic resonance imaging (MRI) and magnetic resonance
angiography (MRA), including the recently developed technique of bolus-contrast
MRA, in patients undergoing postchemotherapy RPLND. METHODS: Eighteen patients
underwent MRI of the retroperitoneal region before RPLND. In addition to routine
sequences, MRA was performed in 10 patients, including 8 with a three-dimensional
technique using bolus intravenous MR contrast. Results were compared with
intraoperative and pathologic findings. RESULTS: MRI and MRA provided detailed
information on retroperitoneal vasculature and its relation to tumor, including
multiple renal vessels (n = 5), duplex inferior vena cava (n = 1), left
retroaortic renal vein (n = 2), and common iliac vein thrombus (n = 1). In all
cases, bolus-contrast MRA provided unique information on the location and number
of renal and lumbar arteries, in addition to information on the aorta and the
mesenteric and iliac vessels. The origin and number of renal arteries were
accurately identified in all patients by bolus-contrast MRA; 2 patients had
supernumerary renal arteries discovered at RPLND that had not been identified on
non-bolus-contrast MRI. CONCLUSIONS: Bolus-contrast three-dimensional MRA
provides unique information on renal and lumbar vessels. The potential benefit of
avoiding vascular injury during dissection should be prospectively evaluated.
PMID- 10688092
TI - Extensive surgery on the trigone for complete ureteral duplication does not cause
incontinence or voiding problems.
AB - OBJECTIVES: To evaluate whether extensive trigonal surgery for duplicated kidneys
is harmful for later bladder and urethral function. METHODS: Of 201 surgically
treated children with kidney and ureteral duplication, 145 were followed up for
at least 1 year. The mean follow-up was 5 years (range 1 to 15), and all patients
were at least 7 years old at the date of their last follow-up visit. Trigone
surgery was performed in 105 children; bilateral trigonal surgery in 26,
unroofing in 25, and total excision in 5. On all later consultations, the
presence of infection, voiding habits, continence pattern, and ultrasound
findings for residual urine volume and kidney function were noted. Children with
recurrent urinary tract infection or dysfunctional voiding for more than 2 years
underwent a urodynamic examination. RESULTS: Nine children, of whom five were
boys, had nocturnal enuresis only. Eight patients had day and nighttime wetting.
Seven of the 8 patients had recurrent urinary infections; urodynamic evaluation
revealed a high compliance (with residual urine) in three of these children and
four had detrusor instability. One girl had an irregular bladder neck, with
stress incontinence. All reflux, whether surgically or conservatively treated and
also three of four occurring de novo, disappeared within 1 year after surgery. In
the group without voiding dysfunctions, seven cystitis and five pyelonephritis
attacks occurred. CONCLUSIONS: Neither extensive trigonal surgery nor pre
existing trigonal deformation by ureteroceles provokes later bladder dysfunction.
PMID- 10688093
TI - Office pediatric urologic procedures from a parental perspective.
AB - OBJECTIVES: To determine the parent perception of discomfort (PPD) in children
receiving local anesthesia for the lysis of labial adhesions, meatotomy, and
newborn circumcision; the parents' perceived outcome of these procedures; and the
overall satisfaction of parents when these procedures are performed in the
office. METHODS: A confidential phone survey was given to 99 parent participants
whose children had received local anesthesia for the lysis of labial adhesions (n
= 14), meatotomy (n = 28), or newborn circumcision (n = 57). Parents in the
labial adhesion and meatal stenosis groups were asked to rate their child's level
of discomfort (PPD) during the procedure as mild (1), moderate (2), or severe
(3), and those in the circumcision group were asked to use the same scale to rate
their child's discomfort after the procedure. Parents were also asked whether
they thought the procedure was successful and whether they were satisfied with
their decision to have it done in the office using local anesthesia. RESULTS:
Among the labial adhesion, meatotomy, and circumcision groups, the mean PPD +/-
SD was 1.64 +/- 0.75, 1.54 +/- 0.69, and 1.21 +/- 0.53, respectively. The
observed procedures, lysis of labial adhesions and meatotomy, had a significantly
higher PPD score (P = 0.005) than the unobserved procedure (circumcision).
Parents reported good outcomes in 94 (94.9%) of 99 children, with 4 girls
experiencing recurrent labial adhesions and 1 boy experiencing recurrent meatal
stenosis. Overall, 95 (96.0%) of 99 parents stated that they were satisfied with
their decision to have the procedure done in the office with local anesthesia. Of
the remaining 4 parents, 3 parents in the circumcision group stated they would
have preferred general anesthesia, and 1 parent in the labial adhesion group was
undecided. CONCLUSIONS: The PPD is greater if the parent observes their child's
procedure. However, office procedures using local anesthesia for the lysis of
labial adhesions, meatotomy, and newborn circumcision are well accepted among the
parent population.
PMID- 10688094
TI - Acucise endopyelotomy.
AB - INTRODUCTION: The evolution of minimally invasive therapy for ureteropelvic
junction (UPJ) obstruction has culminated with the Acucise endopyelotomy.
Antegrade endopyelotomy, laparoscopic pyeloplasty, and ureteroscopic
endopyelotomy all offer excellent minimally invasive alternatives to open
pyeloplasty, yet still represent more invasive techniques than the Acucise
endopyelotomy in treating the obstructed UPJ. TECHNICAL CONSIDERATIONS: The
Acucise endopyelotomy is a straightforward, efficacious, and safe procedure in
the appropriate patient for treating UPJ obstruction. Under fluoroscopic
guidance, the latest version of the Acucise allows the urologist to perform a
retrograde pyelogram, position the Acucise catheter, make the incision, and place
a ureteral stent, all over a single guide wire. In my experience, this latest
technical modification has further simplified the procedure for the practicing
urologist. CONCLUSIONS: In 2000, the Acucise endopyelotomy continues to represent
an excellent minimally invasive option for all urologists who choose to perform
endopyelotomies.
PMID- 10688095
TI - Images in clinical urology. Cystic lymphangioma of the retroperitoneum.
PMID- 10688096
TI - Images in clinical urology. Magnetic resonance imaging of primitive
neuroectodermal tumor of the kidney.
PMID- 10688097
TI - Absence of microsatellite instability in transitional cell carcinoma of the
bladder.
AB - OBJECTIVES: To investigate the prevalence of the microsatellite instability
related to mismatch repair (MMR) gene defects using a panel of six microsatellite
markers, as recommended by a recent workshop on microsatellite instability in
colon cancer, because it is still unclear whether abnormalities in DNA MMR genes
are involved in transitional cell carcinoma (TCC) of the bladder. METHODS: Three
mononucleotide repeats (BAT26, TGFbetaRII, and BAX) were studied in 33 TCC
samples and in four bladder cancer cell lines. Three dinucleotide repeats
(D2S123, D5S346, and D17S250) were studied in 21 of these 33 TCC samples.
RESULTS: No alteration was detected either in the 33 TCC samples analyzed or in
the four bladder cancer cell lines (T24, J82, 647V, and 1207) studied. A
difference between normal and tumor DNA was observed in only 1 of 21 tumor
samples for D17S250. CONCLUSIONS: These data indicate that microsatellite
instability is very uncommon in TCC of the bladder.
PMID- 10688098
TI - Functional evaluation of Tadenan on micturition and experimental prostate growth
induced with exogenous dihydrotestosterone.
AB - OBJECTIVES: To evaluate the effect of Tadenan (TAD; Pygeum africanum extract)
pretreatment on the micturition characteristics of conscious and anesthetized
rats consequent to dihydrotestosterone (DHT) administration and to examine the
influence of such treatment on the growth of the prostate. METHODS: Studies using
40 adult Sprague-Dawley male rats were performed during a 7-week period. These
animals were treated with DHT 1.25 mg/kg subcutaneously dissolved in peanut oil
and/or TAD 100 mg/kg orally dissolved in sesame oil, except for the controls,
which received vehicle only. Rats were divided into four groups: group 1
(control), vehicle only; group 2, DHT administered during weeks 3 and 4; group 3,
TAD pretreatment, administered during weeks 1 and 2, followed by the combined
administration of DHT and TAD during weeks 3 and 4 and TAD only during weeks 5 to
7; and group 4, continuous TAD treatment for 7 weeks. Micturition of conscious
rats was evaluated in metabolic chambers, and in anesthetized rats,
cystometrograms were done at the end of 7 weeks. RESULTS: DHT or DHT plus TAD did
not produce significant changes in the volume but did reduce the frequency of
micturition. TAD given alone significantly increased the volume of micturition
and the rate of urine production. Cystometrographic studies in anesthetized rats
revealed that DHT produced micturition characteristics similar to obstruction.
The DHT plus TAD and TAD pretreatment data showed no significant difference from
controls, suggesting that in the presence of TAD, the effects of DHT were
negated. The total prostate weight of DHT and DHT plus TAD pretreated rats
increased, and in the TAD group, these values decreased to lower than controls;
growth of the ventral lobes was suppressed in the presence of TAD. CONCLUSIONS:
These results demonstrate that TAD pretreatment significantly reduces the
"obstructive" effects of DHT on micturition, counteracts the hormone-induced
enlargement of the prostate, and reduces prostate weight in the ventral but not
the dorsal lobe.
PMID- 10688099
TI - Penile implant success in patients with corporal fibrosis using multiple
incisions and minimal scar tissue excision.
PMID- 10688101
TI - Y2OK! Rollover uneventful for nuclear medicine.
PMID- 10688100
TI - Ultrasound-guided brachytherapy: is it really better?
PMID- 10688102
TI - 99mTc-human serum albumin scans in children with protein-losing enteropathy.
AB - Protein-losing enteropathy (PLE) can be diagnosed scintigraphically using 99mTc
human serum albumin (HSA) scans. METHODS: To evaluate the usefulness of this
method in detecting enteric protein loss, we retrospectively reviewed the 99mTc
HSA scans of 18 children presenting consecutively with PLE. RESULTS: Enteric
99mTc-HSA uptake was noted in 12 patients (8 boys, 4 girls) with a mean age of
7.4 y. Early dynamic images showed abdominal uptake that was most likely in the
small bowel in 91% of the scans. Delayed images showed abnormal accumulation that
was localized in the colon in 73% and in the small bowel in 27% of the scans. A 4
mo follow-up scan obtained in 3 patients showed reduced HSA uptake after a high
protein, low-fat, medium-chain triglyceride oil-based diet and fat-soluble
vitamins. Mean serum albumin, total protein, gammaglobulin, and calcium levels
were significantly decreased. Ten patients (from 4 families) were diagnosed to
have primary intestinal lymphangectasia. One patient had active Salmonella
enterocolitis, and 1 had giardiosis. 99mTc-HSA was normal in the remaining 6
patients (3 boys, 3 girls) with a mean age of 3.5 y (range, 2-5 y). Mean serum
albumin, total protein, gammaglobulin, and calcium levels were less decreased
than those of the first group. Five of these patients had primary intestinal
lymphangactesia (associated with infantile systemic hyalinosis in 1 patient). The
remaining patient had normal duodenal biopsy, and the cause of protein loss
remained unknown. CONCLUSION: The 99mTc-HSA scan is useful in the evaluation of
children with PLE, especially those with severe hypoproteinemia and
hypoalbuminemia, presumably reflecting a high rate of protein loss.
PMID- 10688103
TI - Optimization of automated quantification of 123I-IBZM uptake in the striatum
applied to parkinsonism.
AB - Evaluation of therapies for parkinsonism by dopamine receptor SPECT requires a
reproducible, optimized quantitation technique. This study presents a new,
objective, automated technique for semiquantitative analysis of dopamine receptor
density, as applied to the differential diagnosis of parkinsonism. METHODS:
Dopamine receptor density measured by 123I-iodobenzamide (IBZM) SPECT was
retrospectively analyzed in nonidiopathic parkinsonism (NIPS), in Parkinson's
disease (PD), and in healthy volunteers (n = 19, 38, and 13, respectively). A
mean template was created from coregistered control studies. Registration errors
were assessed using studies with simulated binding deficits. Patient studies were
registered to the mean template, and striatal binding was calculated from a
corresponding map of 3-dimensional regions of interest (ROIs). The striatal
binding ratio and deficits determined by voxelwise comparison with the normal
template were investigated and tested with various 3-dimensional ROI sizes and
positions. Separation of patient groups was determined by tscore after
automatically processing all studies. Results were compared with manual ROI
analyses. RESULTS: The automatic method was completely reproducible in 64 of 70
cases. The best diagnostic discriminator was the minimum binding ratio of the 2
striatal nuclei, with the following values: NIPS, 1.33+/-0.13; PD, 1.50+/-0.12;
healthy volunteers, 1.49+/-0.08 (+/-SD). The deficit size from voxelwise analysis
was: NIPS, 20.5+/-8.2 mL; PD, 9.5+/-8.3; healthy volunteers, 8.9+/-6.0 (+/-SD).
The accuracy, measured by receiver operating characteristic areas, was 0.85+/
0.05, 0.77+/-0.06, and 0.80+/-0.06 (+/-SE) for the optimal predictor (automated)
and 2 blinded observers (manual), respectively. CONCLUSION: A new 3-dimensional,
automated technique has been developed to semiquantitate receptor density that
dramatically improves reproducibility. The optimal diagnostic discriminator of
parkinsonism determined by the automatic technique has good accuracy compared
with the manual technique.
PMID- 10688104
TI - Frontotemporal decreases in rCBF correlate with degree of dysnomia in primary
progressive aphasia.
AB - Primary progressive aphasia (PPA) is an uncommon degenerative dementia
characterized by gradual impairment of language function with initial sparing of
the memory domain. Using semiquantitative 99mTc-hexamethyl propyleneamine oxime
(HMPAO) brain SPECT as a measure of regional cerebral blood flow (rCBF), we
investigated the relationship between reduced 99mTc-HMPAO uptake and the severity
of dysnomia in PPA. METHODS: Seven right-handed patients with PPA had their
dysnomia assessed by the Boston Naming Test (BNT), a subtest of the Boston
Diagnostic Aphasia Examination. Neuroimaging studies, including 99mTc-HMPAO brain
SPECT, CT, and MRI, were performed. Correlational analysis between reduced rCBF
and BNT was performed. RESULTS: Brain SPECT showed a reduction in 99mTc-HMPAO
uptake involving the frontal and temporal lobes in all 7 patients. CT and MRI
showed mild to moderate cerebral atrophy in 4 patients. Low scores on the BNT
correlated with low frontotemporal 99mTc-HMPAO (Spearman r = 0.97, P = 0.004) in
the 5 patients with left-hemisphere involvement. CONCLUSION: Decreased rCBF to
the frontotemporal region characterized the cerebral abnormalities associated
with PPA. The finding of focal rCBF abnormalities in the right hemisphere of 2
right-handed women corroborates that PPA symptoms may arise from a "non-left
dominant"-hemisphere degenerative process. Our results support the usefulness of
rCBF SPECT imaging as a diagnostic aid in PPA.
PMID- 10688105
TI - PET quantification of 5-HT2A receptors in the human brain: a constant infusion
paradigm with [18F]altanserin.
AB - [18F]altanserin has been used to label serotonin 5-HT2A receptors, which are
believed to be important in the pathophysiology of schizophrenia and depression.
The purpose of this study was to test the feasibility of a constant infusion
paradigm for equilibrium modeling of [18F]altanserin with PET. Kinetic modeling
with [18F]altanserin may be hampered by the presence of lipophilic
radiometabolites observed in plasma after intravenous administration. METHODS:
Eight healthy volunteers were injected with [18F]altanserin as a bolus (208+/-9
MBq [5.62+/-0.25 mCi]) plus constant infusion (65+/-3 MBq/h [1.76+/-0.08 mCi/h])
ranging from 555 to 626 min (615+/-24 min) after injection. PET acquisitions (10
20 min) and venous blood sampling were performed every 30-60 min throughout the
infusion period. RESULTS: Linear regression analysis revealed that time-activity
curves for both brain activity and plasma [18F]altanserin and metabolite
concentrations stabilized after about 6 h. This permitted equilibrium modeling
and estimation of V3' (ratio of specific uptake [cortical-cerebellar] to total
plasma parent concentration after 6 h). Values of V3' ranged from 1.57+/-0.38 for
anterior cingulate cortex to 1.02+/-0.39 for frontal cortex. The binding
potential V3 (ratio of specific uptake to free plasma parent concentration after
6 h, using group mean f1) was also calculated and ranged from 169+/-41 for
anterior cingulate cortex to 110+/-42 for frontal cortex. From 6 h onward, the
rate of change for V3' and V3 was only 1.11+/-1.69 %/h. CONCLUSION: These results
demonstrate the feasibility of equilibrium imaging with [18F]altanserin over more
than 5 radioactive half-lives and suggest a method to overcome difficulties
associated with lipophilic radiolabeled metabolites. The stability in V3 and V3'
once equilibrium is achieved suggests that a single PET acquisition obtained at 6
h may provide a reasonable measure of 5-HT2A receptor density.
PMID- 10688106
TI - 123I-interleukin-2 scintigraphy for in vivo assessment of intestinal mononuclear
cell infiltration in Crohn's disease.
AB - Activated mononuclear cells expressing interleukin-2 (IL2) receptors (IL2-Rs)
heavily infiltrate the Crohn's disease (CD) gut wall. A new technique for the in
vivo detection of tissue infiltrating IL2-R positive (IL2R+ve) cells was
developed based on 123I-IL2 scintigraphy. The aim of this study was to
investigate whether 123I-IL2 accumulates in the CD gut wall in different phases
of the disease and to evaluate the specificity of 123I-IL2 binding to activated
IL2R+ve cells infiltrating the gut wall. METHODS: Fifteen patients with ileal CD
(10 active and 5 inactive) and 10 healthy volunteers were studied by 123I-IL2
scintigraphy. Six patients with active CD were studied before and after 12 wk of
steroid treatment. After scintigraphy, patients were followed up for 29-54 mo. Ex
vivo autoradiography was performed to determine specificity of 125I-IL2 binding
to IL2R+ve cells. For bowel scintigraphy, 123I-IL2 (75 MBq) was injected
intravenously and gamma camera images were acquired after 1 h. Bowel
radioactivity was quantified in 64 regions of interest (ROIs). RESULTS:
Autoradiography showed specific binding of 125I-IL2 to IL2R+ve mononuclear cells
infiltrating the CD gut wall. Intestinal 123I-IL2 uptake assessed by the number
of positive ROIs was higher in patients with active or inactive CD than in
healthy volunteers (P < 0.0001 and P = 0.03, respectively) and positively
correlated with the CD activity index (P = 0.01). 123I-IL2 intestinal uptake
significantly decreased in patients with CD in steroid-induced remission (P =
0.03). A significant correlation was observed between the number of positive ROIs
and time to disease relapse. CONCLUSION: 123I-IL2 accumulates in the diseased CD
gut wall by specific binding to IL2R+ve cells, infiltrating the involved tissues.
123I-IL2 scintigraphy may be an objective tool for the in vivo assessment of
intestinal activated mononuclear cell infiltration.
PMID- 10688107
TI - Radiation synovectomy using 165Dy ferric-hydroxide and oxidative DNA damage in
patients with different types of arthritis.
AB - Radiation synovectomy is an effective treatment for chronic synovitis refractory
to pharmacological treatment in patients with rheumatoid or seronegative
arthritis. Concerns persist about possible radiation-induced cytogenetic damage
after radiation synovectomy leading to recommendations to use this technique only
in the elderly. Micronucleus (MN) frequency in lymphocytes and urinary excretion
of 8-hydroxy-2'-deoxyguanosine (8OHdG) as an indicator of cellular oxidative DNA
base damage are biomarkers of radiation-induced cytogenetic damage. The course of
both biomarkers was studied in patients with different types of chronic synovitis
undergoing radiation synovectomy with very short-lived 165Dy-ferric-hydroxide
(DFH). METHODS: Radiation synovectomy of the knee was performed in 13 men and 12
women (mean age, 44+/-15 y) using a mean activity of 9.48+/-1.65 GBq 165Dy-DFH in
27 consecutive treatments. MN frequency in lymphocytes and urinary excretion of
8OHdG, measured by high-performance liquid chromatography, were assessed before
and 4 (MN only) and 20 h after radiation synovectomy. RESULTS: Urinary excretion
of 8OHdG in patients (in micromol/mol creatinine; pretreatment mean, 3.1+/-3.4;
median, 2.27) was not significantly different from that in healthy volunteers
(mean, 2.0+/-1.2; median, 1.87) and not altered by radiation synovectomy (post
treatment mean, 2.5+/-1.5; median, 2.04, NS). An increase in 8OHdG levels after
radiation synovectomy of more than 1 SD was found in only 1 patient, who
experienced leakage to the lymph nodes but who already had elevated urinary 8OHdG
levels before treatment. The frequency of MN/500 binucleated cells (BNCs) was
slightly lower in patients (pretreatment mean, 4.3+/-2.6; median, 4.25) than in
healthy volunteers (mean, 5.4+/-2.3; median, 5.3) and did not significantly
change after therapy, either (4-h post-treatment mean, 3.9+/-2.1, median, 3.8; 20
h post-treatment mean, 4.1+/-2, median 3.8 MN/500 BNC). In 22 of 27 treatments,
no leakage to nontarget organs could be monitored, whereas leakage to the local
lymph nodes and the liver was detected after 5 treatments. CONCLUSION: Radiation
synovectomy using 165Dy-DFH causes no significant radiation burden to most
patients as indicated by the absence of adverse changes in levels of biomarkers
of cytogenetic damage and a low incidence of leakage. These data suggest that the
risk of malignancy may not be elevated.
PMID- 10688108
TI - Sjogren's syndrome: comparison of assessments with quantitative salivary gland
scintigraphy and contrast sialography.
AB - This study compared the quantitative parameters of salivary gland scintigraphy
and the sialographic stages in patients with Sjogren's syndrome. METHODS: One
hundred sixteen patients suspected of having Sjogren's syndrome were examined
with salivary gland scintigraphy and contrast sialography. When contrast
sialography was used as the gold standard, Sjogren's syndrome was diagnosed in 50
of these 116 patients; Sjogren's syndrome was not seen in the other 66 patients.
After injection of 370 MBq 99mTc-sodium pertechnetate, dynamic salivary gland
scintigraphy with lemon juice stimulation was performed for 50 min. Functional
parameters for the parotid and submandibular glands were calculated, and
scintigraphic and sialographic results were compared. RESULTS: With the
progression of sialographic stages from 0 to 4, the quantity of tracer
accumulation decreased in the submandibular gland (P < 0.0001), and the quantity
of tracer secretion decreased in the parotid gland (P < 0.0001). The sialographic
stage in patients with Sjogren's syndrome was correlated with these scintigraphic
parameters (P < 0.0001): sialographic stage = 3.243 - 0.337 x (submandibular
gland uptake ratio) - 0.026 x (parotid gland maximum secretion). CONCLUSION: The
decreased accumulation in the submandibular gland and the decreased secretion in
the parotid gland were highly sensitive indicators of salivary gland disease in
Sjogren's syndrome. The sialographic stage was correlated with these
scintigraphic parameters.
PMID- 10688109
TI - Fewer women than men have positive SPECT and PET cardiac findings among patients
with no history of heart disease.
AB - A lower detection rate of coronary artery disease (CAD) has been reported for
SPECT imaging in women, despite the fact that similar numbers of women and men
die each year of heart disease. Ruling out instrumentation as a possible source
of this low detection rate for CAD in women could be important in determining the
root cause of this difference. METHODS: Patients were referred by cardiologists
and randomized to PET or SPECT by the imaging center. A total of 210 patients
(106 women, 104 men) were enrolled in this study, with 105 imaged by dual-isotope
SPECT and 105 imaged by 82Rb PET. Rest/stress scanning was performed using
dipyridamole. The effects of sex, prior history of CAD, and instrumentation on
the detection of positive scans were determined using multiple logistic
regression analysis with positive scans as the endpoint. RESULTS: For the total
study population, sex and prior history of CAD are significantly associated with
positive scans, whereas imaging modality and age are not. There was no
significant interaction between sex and prior history of CAD. Men have 4.1-fold
greater odds of having a positive nuclear scan than women, and patients with
prior history of CAD have 5.2-fold greater odds of a positive scan after
controlling for the confounding effects of age and imaging modality. In the
subgroup of patients with no prior history of heart disease, men have 3.9-fold
greater odds of a positive scan than women, and the odds ratio of a positive scan
is 2.5-fold greater for PET than for SPECT. There was no statistical difference
in the number of positive scans by SPECT or PET, or positive scans by sex in
patients with documented history of CAD. CONCLUSION: Fewer women than men have
positive nuclear cardiology scans by both PET and SPECT, despite similar
symptoms. Instrumentation characteristics alone do not account for this sex-based
difference and suggest the possibility that early CAD may present differently in
women than in men.
PMID- 10688110
TI - When is hilar uptake of 67Ga-citrate indicative of residual disease after CHOP
chemotherapy?
AB - The purpose of this study was to evaluate the prevalence and characterize the
patterns of hilar uptake (HU) on 67Ga-citrate imaging after cyclophosphamide,
doxorubicin, vincristine, and prednisone (CHOP) chemotherapy regimens for non
Hodgkin's lymphoma (NHL), to differentiate hilar lymphoma (HL) from HU of benign
etiology. METHODS: A total of 930 studies (698 planar, 232 thoracic SPECT) was
reviewed retrospectively in 100 NHL patients (29 low-grade, 60 intermediate
grade, and 11 high-grade) treated with CHOP and followed up longitudinally with
serial gallium studies (planar: median, 7; range, 3-16 studies in 100 patients;
SPECT: median, 1; range, 0-11 studies in 72 patients) over a median duration of
36 mo (range, 6-112 mo) from diagnosis. Clinical outcome and size changes over
time on correlative CT and/or radiographs were used to evaluate benign versus
malignant changes within the hila. RESULTS: HU after CHOP was present in 79% of
patients (90% confidence interval [CI], 71%-85%), with 33% showing HU on SPECT
alone. Once present, HU persisted for a median of 27 mo (range, 2-84 mo) from
onset. The prevalence of HU and HL at various time points was as follows:
baseline HU, 52% with HL 60%; mid-CHOP HU, 59% with HL2%; post-CHOP HU, 52% with
HL6%; follow-up HU, 76% with HL 9%. HU of benign etiology was not significantly
correlated with CHOP dosage. HU was symmetric in 90% of patients (90% CI, 82%
95%) and less intense than the original disease in 89% of patients (90% CI, 80%
95%), and these features were highly predictive of benign etiology (negative
predictive value [NPV], 98.6% if symmetric; NPV, 96.5% if less than original
disease; NPV, 100% if both present). Asymmetric HU equal in intensity to the
original disease, however, was highly predictive of HL (positive predictive value
[PPV], 87.5% if asymmetric; PPV, 85.7% if equal to original disease; PPV, 100% if
both present). CONCLUSION: HU after CHOP is common (overall incidence, 79%),
often seen only on SPECT, and most likely of benign etiology when symmetric and
less intense than the original disease. Asymmetric HU that equals the intensity
of the original disease, however, is a possible indicator for HL.
PMID- 10688111
TI - PET imaging of adrenal cortical tumors with the 11beta-hydroxylase tracer 11C
metomidate.
AB - The purpose of the study was to evaluate PET with the tracer 11C-metomidate as a
method to identify adrenal cortical lesions. METHODS: PET with 11C-metomidate was
performed in 15 patients with unilateral adrenal mass confirmed by CT. All
patients subsequently underwent surgery, except 2 who underwent biopsy only. The
lesions were histopathologically examined and diagnosed as adrenal cortical
adenoma (n = 6; 3 nonfunctioning), adrenocortical carcinoma (n = 2), and nodular
hyperplasia (n = 1). The remaining were noncortical lesions, including 1
pheochromocytoma, 1 myelolipoma, 2 adrenal cysts, and 2 metastases. RESULTS: All
cortical lesions were easily identified because of exceedingly high uptake of 11C
metomidate, whereas the noncortical lesions showed very low uptake. High uptake
was also seen in normal adrenal glands and in the stomach. The uptake was
intermediate in the liver and low in other abdominal organs. Images obtained
immediately after tracer injection displayed high uptake in the renal cortex and
spleen. The tracer uptake in the cortical lesions increased throughout the
examination. For quantitative evaluation of tracer binding in individual lesions,
a model with the splenic radioactivity concentration assigned to represent
nonspecific uptake was applied. Values derived with this method, however, did
show the same specificity as the simpler standardized uptake value concept, with
similar difference observed for cortical versus noncortical lesions. CONCLUSION:
PET with 11C-metomidate has the potential to be an attractive method for the
characterization of adrenal masses with the ability to discriminate lesions of
adrenal cortical origin from noncortical lesions.
PMID- 10688113
TI - Can 11C-methionine play a role in lung cancer staging?
PMID- 10688112
TI - Usefulness of PET with 11C-methionine for the detection of hilar and mediastinal
lymph node metastasis in lung cancer.
AB - We retrospectively evaluated the usefulness of PET with 11C-methionine
(methionine PET) for the diagnosis of lymph node metastases in patients with lung
cancer. METHODS: Methionine PET and CT were performed before surgical
intervention in 41 patients with primary lung cancer. We evaluated individual
lymph nodes by methionine PET along with corresponding CT images. The 11C
methionine accumulation of lymph nodes was assessed semiquantitatively by
analysis of the tumor-to-muscle ratio (TMR) and was compared with CT and
histological diagnoses. RESULTS: A total of 126 lymph nodes, 36 of which were
histologically diagnosed as metastatic, were assessed by CT and methionine PET.
The TMR in metastatic lymph nodes (n = 36) was 5.15+/-1.69, whereas that of
nonmetastatic lymph nodes (n = 90) was 2.91+/-0.76; this difference was
significant (P < 0.0001). The most adequate TMR cutoff value for diagnosis of
metastasis based on the results of receiver operating characteristic curve
analysis was 4.1. The positive and negative predictive values, sensitivity,
specificity, and accuracy of methionine PET were 79.5%, 94.3%, 86.1%, 91.1%, and
89.7%, respectively, and were superior to those of CT (57.6%, P = 0.04; 81.7%, P
= 0.008; 52.8%, P = 0.002; 84.4%, NS; and 75.4%, P = 0.002, respectively). All
positive nodes that were shown to be true-positive by CT, and 12 of 17 false
negatives on CT were correctly diagnosed by PET. Ten of 14 lymph nodes that were
false-positive on CT were also correctly diagnosed by PET. CONCLUSION: Methionine
PET appears to be superior to CT for the diagnosis of lymph node metastasis in
lung cancer patients. The high negative predictive value of methionine PET
suggests that cases in which lymph nodes are enlarged on CT with negative PET
analysis may be diagnosed as negative for metastasis.
PMID- 10688114
TI - Iodinated free fatty acid and 201T1 uptake in chronically hypoperfused
myocardium: histologic correlation study.
AB - 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) is a tracer for
the evaluation of ischemic heart disease. The purpose of this study was to assess
the relationship between 1231-BMIPP uptake and myocardial fibrosis. METHODS:
Fifteen patients who underwent cardiac surgery were examined by imaging with
201TI and 123I-BMIPP, and histologic specimens were taken during surgery. The
relative uptake of 201TI (%TI) and that of 123I-BMIPP (%BMIPP) were calculated.
The percentage of fibrosis (%fibrosis) was analyzed with the specimen. RESULTS:
%TI correlated strongly with %fibrosis (r = -0.94; P < 0.001). %BMIPP also
correlated significantly with %fibrosis (r = -0.88; P < 0.001), but the change in
%BMIPP looked biphasic. In the category of only mild fibrosis, %BMIPP showed a
steep decrease. 123I-BMIPP-201TI mismatch was found only for fibrosis <20%.
CONCLUSION: 123I-BMIPP gave specific information about metabolic changes that
occurred in ischemic myocardium without severe fibrotic changes.
PMID- 10688115
TI - Internal radionuclide radiation dosimetry: a review of basic concepts and recent
developments.
AB - Internal dosimetry deals with the determination of the amount and the spatial and
temporal distribution of radiation energy deposited in tissue by radionuclides
within the body. Nuclear medicine has been largely a diagnostic specialty, and
model-derived average organ dose estimates for risk assessment, the traditional
application of the MIRD schema, have proven entirely adequate. However, to the
extent that specific patients deviate kinetically and anatomically from the model
used, such dose estimates will be inaccurate. With the increasing therapeutic
application of internal radionuclides and the need for greater accuracy,
radiation dosimetry in nuclear medicine is evolving from population- and organ
average to patient- and position-specific dose estimation. Beginning with the
relevant quantities and units, this article reviews the historical methods and
newly developed concepts and techniques to characterize radionuclide radiation
doses. The latter include the 3 principal approaches to the calculation of
macroscopic nonuniform dose distributions: dose point-kernel convolution, Monte
Carlo simulation, and voxel S factors. Radiation dosimetry in "sensitive"
populations, including pregnant women, nursing mothers, and children, also will
be reviewed.
PMID- 10688116
TI - Performance of a 62Zn/62Cu generator in clinical trials of PET perfusion agent
62Cu-PTSM.
AB - The 62Zn/62Cu PET generator can be inexpensively produced and distributed from a
single production site operating under typical good manufacturing practice
guidelines. It therefore has the potential to greatly facilitate development of
clinically practical PET. We report generator performance in a study in which
62Cu-pyruvaldehyde-bis(n4-methylthiosemicarbazone (PTSM) myocardial perfusion
imaging is compared with 99mTc-sestamibi in the diagnosis of coronary artery
disease. The 62Zn/62Cu generator is an improved version of a previously reported
system that employs automated synthesis of 62Cu-PTSM. With this approach, the
cumbersome step of 18C purification has been eliminated. METHODS: The 62Zn (9.3 h
half-life) parent isotope is prepared by proton bombardment of natural copper at
33 MeV. A typical target irradiated with 37.5 microA/h is delivered by 12:00 PM
on the day it is to be processed. Purified 62Zn obtained from the target is
loaded onto the generator column in 2 mol/L HCl. The generator is eluted using an
internal three-channel peristaltic pump, which delivers 2.25 mL eluant (1.8 mol/L
NaCl, 0.2 mol/L HCl) through the generator column to elute the 62Cu in 40 s. The
same pump simultaneously pumps an equal volume of buffer (0.4 mol/L NaOAc) and 1
mL ligand solution (2 ppm PTSM, 2% EtOH) passing it through a septum into a 35-cc
syringe preloaded with 28 mL sterile water. This solution is thoroughly mixed by
agitation of the syringe and injected as a bolus through a 0.2 microm filter. The
generator is eluted twice before shipping, providing quality assurance samples,
and shipped to the clinical site by overnight delivery. Complete quality
assurance testing is performed the evening before the generator reaches the
clinical site. RESULTS: A total of 34 generators have been produced and shipped
to 2 clinical sites for a phase III Food and Drug Administration study. The load
activity on the generators at 8:00 AM the day of clinical use was 1.7+/-0.2 GBq
(46.7+/-5.6 mCi), and yield was 72%+/-16%. Breakthrough of 62Zn was undetectable
by high-purity germanium spectroscopy for all units. Radiochemical purity was
95.4%+/-2.4%. Volume delivered, pH, sterility, and bacterial endotoxin tests
yielded passing results on all generators. The entire process of generator
production, from target receipt to generator shipment, took less than 6 h and
cost approximately $1000, including shipping charges and cyclotron cost. A total
of 68 patients were injected with 2 62Cu-PTSM doses, with a mean injected
activity of 0.8+/-0.2 GBq (20.5+/-5.3 mCi) with no adverse side effects.
CONCLUSION: Results of this work confirm that the 62Zn/62Cu generator is an
easily produced, transportable, and inexpensive source of PET
radiopharmaceuticals, which can expand the field of clinical PET imaging by
providing radiopharmaceuticals to sites not associated with cyclotrons.
PMID- 10688117
TI - The potential role of generator-produced radiopharmaceuticals in clinical PET.
PMID- 10688118
TI - Effects of insulinlike growth factor binding proteins on insulinlike growth
factor-I biodistribution in tumor-bearing nude mice.
AB - This study evaluated the biodistribution and tumor targeting ability of
radiolabeled insulinlike growth factor (IGF)-I. Because IGF binding proteins
(IGFBPs) play a critical role in modulating IGF activity, the binding properties
of 125I-labeled IGF-I to IGFBPs were investigated in vitro and in vivo. Because a
large amount of the IGF-I was catabolized in vivo, we also studied the catabolism
of IGF-I by tumor cells in vitro. METHODS: 125I-labeled-IGF-I was prepared using
the chloramine T method. The biodistribution of 125I-labeled-IGF-I in tumor
bearing nude mice was compared between groups injected with 125I-labeled IGF-I
alone or coinjected with unlabeled peptide. In vitro and in vivo chromatography
studies were performed to evaluate the binding profile to IGFBPs and the degree
of catabolites in serum as well as urine. RESULTS: Data indicated that the
binding of radiolabeled IGF-I to IGFBPs in vitro was dose dependent. However,
there was a difference in complex formation between the serum and the heparinized
plasma. In heparinized plasma, the radioactivity shifted from a 30- to 50-kDa
complex to a 150-kDa complex and to a free ligand, because the binding of heparin
with IGFBPs decreased its affinity for IGF-I. In plasma prepared with acid
citrate dextrose a binding pattern identical to that of serum was observed.
Moreover, there was a binding difference between mouse and rat. The 125I-labeled
IGF-I catabolized very quickly when incubated at 37 degrees C but not at all at 4
degrees C. In tumor-bearing nude mice, the uptake of radioactivity in normal
tissues decreased quickly, particularly in the kidneys. In mice coinjected with
unlabeled carrier, the radioactivity in most normal tissues was lower and the
tumor uptake higher than in the mice without carrier. CONCLUSION: These data
confirm that 125I-labeled IGF-I is avidly bound to IGFBPs, both in vitro and in
vivo. By partially saturating this binding with unlabeled peptides, a favorable
biodistribution was achieved, including faster clearance from normal tissue and
higher tumor uptake, which resulted in better tumor-to-nontumor ratios.
Nevertheless, the rapid catabolism and release of the radiolabel from tumor
tissue result in a suboptimal targeting agent.
PMID- 10688119
TI - Noninvasive detection of tumor hypoxia using the 2-nitroimidazole [18F]EF1.
AB - The noninvasive assessment of tumor hypoxia in vivo is under active investigation
because hypoxia has been shown to be an important prognostic factor for therapy
resistance. Various nuclear medicine imaging modalities are being used, including
PET imaging of 18F-containing compounds. In this study, we report the development
of 18F-labeled EF1 for noninvasive imaging of hypoxia. EF1 is a 3-monofluoro
analog of the well-characterized hypoxia marker EF5, 2(2-nitro-1H-imidazol-1-yl)
N-(2,2,3,3,3-pentafluoropropyl)acetami de, which has been used to detect hypoxia
in tumor and nontumor systems using immunohistochemical methods. METHODS: We have
studied 2 rat tumor types: the hypoxic Morris 7777 (Q7) hepatoma and the oxic 9LF
glioma tumor, each grown in subcutaneous sites. PET studies were performed using
a pharmacological dose of nonradioactive carrier in addition to [18F]EF1 to
optimize and assess drug biodistribution. After PET imaging of the tumor-bearing
rats, tissues were obtained for gamma-counting of the 18F in various tissues and
immunohistochemical detection of intracellular drug adducts in tumors. In one
pair of tumors, Eppendorf needle electrode studies were performed. RESULTS:
[18F]EF1 was excreted dominantly through the urinary tract. The tumor-to-muscle
(T/M) ratio of [18F]EF1 in the Q7 tumors was 2.7 and 2.4 based on PET studies and
2.1, 2.5, and 3.0 based on gamma-counting of the tissues (n = 3). In contrast,
the T/M ratio of [18F]EF1 in the 9LF glioma tumor was 0.8 and 0.5 based on PET
studies and 1.0, 1.2, and 1.4 based on gamma-counting of the tissues (n = 3).
Immunohistochemical analysis of drug adducts for the two tumor types agreed with
the radioactivity analysis. In the Q7 tumor, substantial heterogeneous binding
was observed throughout the tumor, whereas in the 9LF tumor minimal binding was
found. CONCLUSION: [18F]EF1 is an excellent radiotracer for noninvasive imaging
of tumor hypoxia.
PMID- 10688120
TI - CaNa2EDTA for improvement of radioimmunodetection and radioimmunotherapy with
111In and 90Y-DTPA-anti-CEA MAbs in nude mice bearing human colorectal cancer.
AB - 111In and 90Y, dissociated from 111In-labeled-monoclonal antibody (MAb) and 90Y
labeled MAb, may cause deterioration of the image quality in radioimmunodetection
(RID) and undesirable irradiation of nontargeted tissue in radioimmunotherapy
(RIT), respectively. The aim of this study was to investigate any improvement in
RID and RIT with 111In-MAb and 90Y-MAb by pre- and postadministration of calcium
disodium ethylenetriaminetetraacetic acid (CaNa2EDTA). METHODS: Murine MAb F33
104 against carcinoembryonic antigen (CEA) was labeled with 111In or 90Y by the
diethylenetriamine pentaacetic (DTPA)-anhydride method. The influence of
CaNa2EDTA on loss of radioactivity from 111In-MAb or 90Y-MAb in serum was
investigated in vitro. The effects of CaNa2EDTA, administered before and after
111In-MAb or 90Y-MAb, on the biodistribution of radioactive isotopes in nude mice
bearing human colon adenocarcinoma LS 180 tumor expressing CEA, or human
pulmonary carcinoma PC 9 tumor expressing no CEA, were then examined. As a
control, 0.9% NaCl was used in both the in vitro and in vivo studies. RESULTS:
CaNa2EDTA did not cause any decrease in levels of radioactivity of radiolabeled
MAbs. Pre- and post-treatment with CaNa2EDTA reduced radioctivity in both
specific and nonspecific tumors at 72 h after 111In-MAb injection resulting in an
increase of the specific tumor-to-nonspecific tumor radioactivity ratio. The
levels of hepatic and renal radioactivity were also subsequently decreased by
CaNa2EDTA. On the other hand, CaNa2EDTA pre- and post-treatment reduced levels of
bony, hepatic, and renal radioactivity at 24, 72, and 72 h, respectively, after
90Y-MAb injection, although it had no effect on tumor radioactivity. CONCLUSION:
Pre- and post-treatment with CaNa2EDTA would be of great use in humans who
undergo RID or RIT with 111In-MAb and 90Y-MAb accompanied by disassociation of
the labeled radionuclides.
PMID- 10688121
TI - 11C-labeled KF18446: a potential central nervous system adenosine A2a receptor
ligand.
AB - To develop PET ligands for mapping central nervous system (CNS) adenosine A2a
receptors that are localized in the striatum and are coupled with dopamine
receptors, 3 11C-labeled xanthine-type adenosine A2a antagonists, [11C]KF18446
([7-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthin e),
[11C]KF19631 ([7-methyl-11C]-(E)-1,3-diallyl-7-methyl-8-(3,4,5
trimethoxystyryl)xanth ine), and [11C]CSC ([7-methyl-11C]-8
chlorostyrylcaffeine), were compared with [11C]KF17837 ([7-methyl-11C]-(E)-8-(3,4
dimethoxystyryl)-1,3-dipropyl-7-methylx anthine). METHODS: The regional brain
uptake of the tracers, the effect of the coinjected adenosine antagonists on the
uptake, and the metabolism were studied in mice. In rats, the regional brain
uptake of the tracers was visualized by ex vivo autoradiography (ARG). The A2a
receptor binding of antagonist 1 was also measured by in vitro ARG. Imaging of
the monkey brain was performed with PET with antagonist 1. RESULTS: In mice, the
highest striatal uptake was found for antagonist 1 followed by antagonists 2 and
4. The uptake was inhibited by each of 3 KF compounds and by CSC, but not by an
A1 antagonist KF15372. Another selective nonxanthine-type A2a antagonist SCH
58261 significantly decreased the striatal uptake of only antagonist 1, the
labeled metabolites of which were less than 20% in the plasma 30 min
postinjection, but were negligible in the brain tissue. In ex vivo ARG,
antagonist 1 showed the highest striatal uptake and the highest uptake ratio of
the striatum to the other brain regions. A high and selective binding of
antagonist 1 to the striatum was also confirmed by in vitro ARG. PET with
antagonist 1 visualized adenosine A2a receptors in the monkey striatum.
CONCLUSION: These results indicate that antagonist 1 ([11C]KF18446) is the most
suitable PET ligand for mapping adenosine A2a receptors in the CNS.
PMID- 10688122
TI - Single amino acid substitution in the Fc region of chimeric TNT-3 antibody
accelerates clearance and improves immunoscintigraphy of solid tumors.
AB - Recent studies in antibody catabolism have identified residues at the CH2-CH3
interface of the IgG heavy chain critical for serum persistence of
immunoglobulins. Amino acid substitutions in the Fc region of murine IgG1 were
shown to drastically accelerate antibody clearance in mice. Our laboratory has
previously described a human-mouse chimeric TNT-3 (chTNT-3) monoclonal antibody
directed against a universal nuclear antigen that has potential for the
radioimmunotherapy of many solid tumors. In the current study, we engineered a
chTNT-3 mutant containing a single amino acid substitution, to determine whether
a more rapid clearance profile would make the antibody suitable for diagnostic
imaging. METHODS: A single amino acid substitution in the CH2 domain of the human
gamma1 constant region was made by polymerase chain reaction mutagenesis. High
level expression was achieved using the Glutamine Synthetase Gene Amplification
System, and the chTNT-3 mutant was purified by protein A affinity and ion
exchange chromatography. A radioimmunoassay was performed to examine antigen
binding, and in vivo studies were undertaken to evaluate clearance and tumor
targeting in human tumor xenograft models. RESULTS: The chTNT-3 mutant retained
the high affinity of chTNT-3, with a binding constant of 1.5 x 10(-9) mol/L. The
mutant was eliminated rapidly from BALB/c mice, with a beta-phase half-life of
33.8 h, compared to 134.2 h for chTNT-3. Moreover, biodistribution studies in
human colon tumor-bearing nude mice reflected this accelerated clearance. Tumor
levels of the mutant were, respectively, 65%, 39%, and 36% of the tumor levels
achieved with the parental chTNT-3 6, 12, and 24 h postinjection. The rapid
clearance of the chTNT-3 mutant from the blood resulted in higher tumor-to-normal
organ ratios for many normal tissues. Imaging of tumor-bearing mice with 99mTc
labeled chTNT-3 mutant demonstrated early visualization of tumors in 3 different
solid tumor xenograft models. CONCLUSION: The accelerated clearance produced by a
single amino acid substitution in the Fc region of chTNT-3 leads to improved
imaging in tumor-bearing mice. These studies suggest that a rapidly clearing
antibody generated by this approach may be useful for the immunoscintigraphy of
human tumors.
PMID- 10688123
TI - Inflammation and infection imaging with a 99mTc-neutrophil elastase inhibitor in
monkeys.
AB - A radiolabeled human neutrophil elastase inhibitor (EPI-HNE-2) may represent an
improved nuclear medicine imaging agent for inflammation and infection. This
peptide displays rapid pharmacokinetics due to its low molecular weight and
localizes specifically on neutrophil elastase released in inflammatory sites by
activated neutrophils. METHODS: In this investigation, the peptide was
radiolabeled with 99mTc using N-hydroxysuccinimidyl S
acetylmercaptoacetyltriglycline (NHS-MAG3) as a bifunctional chelator and was
administered on 18 occasions to 5 rhesus monkeys with inflammation/infection.
RESULTS: Plasma clearance was rapid, with liver and kidneys representing the
major organs of accumulation. No evidence of toxicity, dosage effects, or
circulating antiMAG3-EPI-HNE-2 antibodies was observed. Specificity of
localization was established using radiolabeled bovine pancreatic trypsin
inhibitor (a non-hNE-binding peptide of similar size) as a nonspecific negative
control peptide and by predosing with unlabeled EPI-HNE-2 to block receptor sites
before the administration of radiolabeled EPI-HNE-2. The ability of radiolabeled
EPI-HNE-2 to image inflammation/infection was evaluated in 12 studies in monkeys
receiving only radiolabeled EPI-HNE-2 and with lesions in the arm, shoulder, or
lower back. Positive images were obtained in all studies, uptake was apparent
almost immediately, and images were still positive 24 h later. As a positive
control, animals also received nonspecific IgG antibody radiolabeled with 99mTc
either directly or by NHS-MAG3. Compared with labeled antibody, plasma clearance
of 99mTc was faster with labeled EPI-HNE-2 and accumulation in liver and heart
was lower. Uptake of radioactivity in the inflammation was higher during the
first hour with EPI-HNE-2 versus antibody but lower thereafter. CONCLUSION: When
radiolabeled with 99mTc, EPI-HNE-2 localized specifically in inflammations in a
monkey model and provided early images of diagnostic quality.
PMID- 10688124
TI - Nuclear medicine image registration by spatially noncoherent interferometry.
AB - This article introduces a technique for obtaining high-resolution body contour
data in the same coordinate frame as that of a rotating gamma camera, using a
miniature range finder, the conoscope, mounted on the camera gantry. One
potential application of the technique is accurate coregistration in longitudinal
brain SPECT studies, using the face of the patient (or "mask"), instead of SPECT
slices, to coregister subsequent acquisitions involving the brain. METHODS:
Conoscopic holography is an interferometry technique that relies on spatially
incoherent light interference in birefringent crystals. In this study, the
conoscope was used to measure the absolute distance (Z) between a light source
reflected from the skin and its observation plane. This light was emitted by a
0.2-mW laser diode. A scanning system was used to image the face during SPECT
acquisition. The system consisted of a motor-driven mirror (Y axis) and the gamma
camera gantry (1 profile was obtained for each rotation step, X axis). The system
was calibrated to place the conoscopic measurements and SPECT slices in the same
coordinate frame. RESULTS: Through a simple and robust calibration of the system,
the SE for measurements performed on geometric shapes was less than 2 mm, i.e.,
less than the actual pixel size of the SPECT data. Biometric measurements of an
anthropomorphic brain phantom were within 3%-5% of actual values. The mask data
were used to register images of a brain phantom and of a volunteer's brain,
respectively. The rigid transformation that allowed the merging of masks by
visual inspection was applied to the 2 sets of SPECT slices to perform the fusion
of the data. CONCLUSION: At the cost of an additional low-cost setup integrated
into the gamma-camera gantry, real-time data about the surface of the head were
obtained. As in all other surface-based techniques (as opposed to volume-based
techniques), this method allows the match of data independently from the dataset
of interest and facilitates further registration of data from any other source.
The main advantage of this technique compared with other optically based methods
is the robustness of the calibration procedure and the compactness of the sensor
as a result of the colinearity of the projected beam and the reflected (diffused)
beams of the conoscope. Taking into account the experimental nature of this
preliminary work, significant improvements in the accuracy and speed of
measurements (up to 1000 points/s) are expected.
PMID- 10688125
TI - National Electrical Manufacturers Association recommendations for implementing
SPECT instrumentation quality control.
PMID- 10688126
TI - Effect of obesity on red cell mass.
PMID- 10688127
TI - Mammography and 99mTc-MIBI scintimammography in suspected breast cancer.
PMID- 10688128
TI - Evolution of genes and taxa: a primer.
AB - The rapidly growing fields of molecular evolution and systematics have much to
offer to molecular biology, but like any field have their own repertoire of terms
and concepts. Homology, for example, is a central theme in evolutionary biology
whose definition is complex and often controversial. Homology extends to
multigene families, where the distinction between orthology and paralogy is key.
Nucleotide sequence alignment is also a homology issue, and is a key stage in any
evolutionary analysis of sequence data. Models based on our understanding of the
processes of nucleotide substitution are used both in the estimation of the
number of evolutionary changes between aligned sequences and in phylogeny
reconstruction from sequence data. The three common methods of phylogeny
reconstruction--parsimony, distance and maximum likelihood--differ in their use
of these models. All three face similar problems in finding optimal--and reliable
-solutions among the vast number of possible trees. Moreover, even optimal trees
for a given gene may not reflect the relationships of the organisms from which
the gene was sampled. Knowledge of how genes evolve and at what rate is critical
for understanding gene function across species or within gene families. The
Neutral Theory of Molecular Evolution serves as the null model of molecular
evolution and plays a central role in data analysis. Three areas in which the
Neutral Theory plays a vital role are: interpreting ratios of nonsynonymous to
synonymous nucleotide substitutions, assessing the reliability of molecular
clocks, and providing a foundation for molecular population genetics.
PMID- 10688129
TI - Examining rates and patterns of nucleotide substitution in plants.
AB - Driven by rapid improvements in affordable computing power and by the even faster
accumulation of genomic data, the statistical analysis of molecular sequence data
has become an active area of interdisciplinary research. Maximum likelihood
methods have become mainstream because of their desirable properties and, more
importantly, their potential for providing statistically sound solutions in
complex data analysis settings. In this chapter, a review of recent literature
focusing on rates and patterns of nucleotide substitution rates in the nuclear,
chloroplast, and mitochondrial genomes of plants demonstrates the power and
flexibility of these new methods. The emerging picture of the nucleotide
substitution process in plants is a complex one. Evolutionary rates are seen to
be quite variable, both among genes and among plant lineages. However, there are
hints, particularly in the chloroplast, that individual factors can have
important effects on many genes simultaneously.
PMID- 10688130
TI - Contributions of plant molecular systematics to studies of molecular evolution.
AB - Dobzhansky stated that nothing in biology makes sense except in the light of
evolution. A close corollary, and the central theme of this paper, is that
everything makes a lot more sense in the light of phylogeny. Systematics is in
the midst of a renaissance, heralded by the widespread application of new
analytical approaches and the introduction of molecular techniques. Molecular
phylogenetic analyses are now commonplace, and they have provided unparalleled
insights into relationships at all levels of plant phylogeny. At deep levels,
molecular studies have revealed that charophyte green algae are the closest
relatives of the land plants and suggested that liverworts are sister to all
other extant land plants. Other studies have suggested that lycopods are sister
to all other vascular plants and clarified relationships among the ferns. The
impact of molecular phylogenetics on the angiosperms has been particularly
dramatic--some of the largest phylogenetic analyses yet conducted have involved
the angiosperms. Inferences from three genes (rbcL, atpB, 18S rDNA) agree in the
major features of angiosperm phylogeny and have resulted in a reclassification of
the angiosperms. This ordinal-level reclassification is perhaps the most dramatic
and important change in higher-level angiosperm taxonomy in the past 200 years.
At lower taxonomic levels, phylogenetic analyses have revealed the closest
relatives of many crops and 'model organisms' for studies of molecular genetics,
concomitantly pointing to possible relatives for use in comparative studies and
plant breeding. Furthermore, phylogenetic information has contributed to new
perspectives on the evolution of polyploid genomes. The phylogenetic trees now
available at all levels of the taxonomic hierarchy for angiosperms and other
green plants should play a pivotal role in comparative studies in diverse fields
from ecology to molecular evolution and comparative genetics.
PMID- 10688131
TI - Molecular evolution of the chalcone synthase multigene family in the morning
glory genome.
AB - Plant genomes appear to exploit the process of gene duplication as a primary
means of acquiring biochemical and developmental flexibility. Thus, for example,
most of the enzymatic components of plant secondary metabolism are encoded by
small families of genes that originated through duplication over evolutionary
time. The dynamics of gene family evolution are well illustrated by the genes
that encode chalcone synthase (CHS), the first committed step in flavonoid
biosynthesis. We review pertinent facts about CHS evolution in flowering plants
with special reference to the morning glory genus, Ipomoea. Our review shows that
new CHS genes are recruited recurrently in flowering plant evolution. Rates of
nucleotide substitution are frequently accelerated in new duplicate genes, and
there is clear evidence for repeated shifts in enzymatic function among duplicate
copies of CHS genes. In addition, we present new data on expression patterns of
CHS genes as a function of tissue and developmental stage in the common morning
glory (I. purpurea). These data show extensive differentiation in gene expression
among duplicate copies of CHS genes. We also show that a single mutation which
blocks anthocyanin biosynthesis in the floral limb is correlated with a loss of
expression of one of the six duplicate CHS genes present in the morning glory
genome. This suggests that different duplicate copies of CHS have acquired
specialized functional roles over the course of evolution. We conclude that
recurrent gene duplication and subsequent differentiation is a major adaptive
strategy in plant genome evolution.
PMID- 10688132
TI - Myrosinase: gene family evolution and herbivore defense in Brassicaceae.
AB - Glucosinolates are a category of secondary products present primarily in species
of the order Capparales. When tissue is damaged, for example by herbivory,
glucosinolates are degraded in a reaction catalyzed by thioglucosidases, denoted
myrosinases, also present in these species. Thereby, toxic compounds such as
nitriles, isothiocyanates, epithionitriles and thiocyanates are released. The
glucosinolate-myrosinase system is generally believed to be part of the plant's
defense against insects, and possibly also against pathogens. In this review, the
evolution of the system and its impact on the interaction between plants and
insects are discussed. Further, data suggesting additional functions in the
defense against pathogens and in sulfur metabolism are reviewed.
PMID- 10688133
TI - A short history of MADS-box genes in plants.
AB - Evolutionary developmental genetics (evodevotics) is a novel scientific endeavor
which assumes that changes in developmental control genes are a major aspect of
evolutionary changes in morphology. Understanding the phylogeny of developmental
control genes may thus help us to understand the evolution of plant and animal
form. The principles of evodevotics are exemplified by outlining the role of MADS
box genes in the evolution of plant reproductive structures. In extant
eudicotyledonous flowering plants, MADS-box genes act as homeotic selector genes
determining floral organ identity and as floral meristem identity genes. By
reviewing current knowledge about MADS-box genes in ferns, gymnosperms and
different types of angiosperms, we demonstrate that the phylogeny of MADS-box
genes was strongly correlated with the origin and evolution of plant reproductive
structures such as ovules and flowers. It seems likely, therefore, that changes
in MADS-box gene structure, expression and function have been a major cause for
innovations in reproductive development during land plant evolution, such as
seed, flower and fruit formation.
PMID- 10688134
TI - Knots in the family tree: evolutionary relationships and functions of knox
homeobox genes.
AB - Knotted-like homeobox (knox) genes constitute a gene family in plants. Class I
knox genes are expressed in shoot apical meristems, and (with notable exceptions)
not in lateral organ primordia. Class II genes have more diverse expression
patterns. Loss and gain of function mutations indicate that knox genes are
important regulators of meristem function. Gene duplication has contributed to
the evolution of families of homeodomain proteins in metazoans. We believe that
similar mechanisms have contributed to the diversity of knox gene function in
plants. Knox genes may have contributed to the evolution of compound leaves in
tomato and could be involved in the evolution of morphological traits in other
species. Alterations in cis-regulatory regions in some knox genes correlate with
novel patterns of gene expression and distinctive morphologies. Preliminary data
from the analysis of class I knox gene expression illustrates the evolution of
complex patterns of knox expression is likely to have occurred through loss and
gain of domains of gene expression.
PMID- 10688135
TI - Evolutionary genetics of self-incompatibility in the Solanaceae.
AB - The self-incompatibility (S) gene in flowering plants has long been appreciated
as an example of extreme allelic polymorphism maintained by frequency-dependent
selection. Recent studies of population samples of S-allele sequences obtained by
RT-PCR from five species of Solanaceae now reveal a picture of conspicuous inter
specific variation in both S-allele number and age. Explanations for this
variation are examined with reference to current theory. We propose that changes
in species' effective population size, particularly those associated with the
evolution of different life histories, best account for interspecific differences
in both the number and average age of S alleles.
PMID- 10688136
TI - The evolution of nodulation.
AB - In this review we will first describe the different steps leading to nodule
formation, and these will be compared with processes of non-symbiotic plant
development and growth. In general, aspects of both actinorhizal as well as
rhizobial symbiosis are described, but in several cases, the emphasis will be on
the Rhizobium-legume symbiosis because more knowledge of this system is
available. Subsequently, the phylogeny of nodulating plants is described and a
comparison is made between several aspects of legume and actinorhizal nodulation.
At the end of this paper the relationship between nodule symbiosis and
endomycorrhizal symbiosis is described, and it is discussed to what extent the
development of root nodules involves unique properties, or whether processes and
genes have been recruited from common plant development and the endomycorrhizal
symbiosis.
PMID- 10688137
TI - The evolution of disease resistance genes.
AB - Several common themes have shaped the evolution of plant disease resistance
genes. These include duplication events of progenitor resistance genes and
further expansion to create clustered gene families. Variation can arise from
both intragenic and intergenic recombination and gene conversion. Recombination
has also been implicated in the generation of novel resistance specificities.
Resistance gene clusters appear to evolve more rapidly than other regions of the
genome. In addition, domains believed to be involved in recognitional
specificity, such as the leucine-rich repeat (LRR), are subject to adaptive
selection. Transposable elements have been associated with some resistance gene
clusters, and may generate further variation at these complexes.
PMID- 10688138
TI - Hybridization, introgression, and linkage evolution.
AB - Genetic mapping methods provide a unique opportunity to study the interactions of
differentiated genes and genomes in a hybrid genetic background. After a brief
discussion of theoretical and analytical concerns, we review the application of
these methods to a wide range of evolutionary issues. Map-based studies of
experimental hybrids indicate that most postzygotic reproductive barriers in
plants are polygenic and that the expression of extreme or novel traits in
segregating hybrids (transgressive segregation) results from the complementary
action of divergent parental alleles. However, genetic studies of hybrid vigor do
not concur in their interpretations of the relative roles of dominance,
overdominance, and epistasis. Map-based studies of natural hybrids are much
rarer, but the few existing studies confirm the polygenic basis of postzygotic
barriers and demonstrate the utility of genetic linkage for detecting cryptic
introgression. In addition, studies of experimental and natural hybrid lineages
provide compelling evidence that homoploid hybrid speciation has occurred in
nature, and that it represents a rapid and repeatable mode of speciation. Data
further indicate that this mode is facilitated by strong fertility selection and
high chromosomal mutation rates. We recommend that future studies of hybrid
genomes focus on natural hybrids, not only because of the paucity of data in this
area, but also because of the availability of highly recombinant hybrid genotypes
in hybrid zones. Of particular value will be studies of long-lived or difficult
to-propagate organisms, which previously have not been amenable to genetic study.
PMID- 10688141
TI - TB & HIV, applying advances--Chicago 1999
PMID- 10688139
TI - Genome evolution in polyploids.
AB - Polyploidy is a prominent process in plants and has been significant in the
evolutionary history of vertebrates and other eukaryotes. In plants,
interdisciplinary approaches combining phylogenetic and molecular genetic
perspectives have enhanced our awareness of the myriad genetic interactions made
possible by polyploidy. Here, processes and mechanisms of gene and genome
evolution in polyploids are reviewed. Genes duplicated by polyploidy may retain
their original or similar function, undergo diversification in protein function
or regulation, or one copy may become silenced through mutational or epigenetic
means. Duplicated genes also may interact through inter-locus recombination, gene
conversion, or concerted evolution. Recent experiments have illuminated important
processes in polyploids that operate above the organizational level of duplicated
genes. These include inter-genomic chromosomal exchanges, saltational, non
Mendelian genomic evolution in nascent polyploids, inter-genomic invasion, and
cytonuclear stabilization. Notwithstanding many recent insights, much remains to
be learned about many aspects of polyploid evolution, including: the role of
transposable elements in structural and regulatory gene evolution; processes and
significance of epigenetic silencing; underlying controls of chromosome pairing;
mechanisms and functional significance of rapid genome changes; cytonuclear
accommodation; and coordination of regulatory factors contributed by two,
sometimes divergent progenitor genomes. Continued application of molecular
genetic approaches to questions of polyploid genome evolution holds promise for
producing lasting insight into processes by which novel genotypes are generated
and ultimately into how polyploidy facilitates evolution and adaptation.
PMID- 10688142
TI - Molecular determinants of drug resistance in tuberculosis.
AB - Rapid detection of drug-resistant tuberculosis (TB) has become increasingly
important in the era of pandemic human immunodeficiency virus infection and
antibiotic resistance. The identification of the molecular correlates of
antibiotic resistance in Mycobacterium tuberculosis have engendered the
development of DNA-based assays for the identification of drug-resistant TB. This
review summarizes the recent discoveries concerning resistance to isoniazid,
rifampin, pyrazinamide, ethambutol, streptomycin, amikacin, kanamycin and the
quinolones.
PMID- 10688143
TI - Lung-specific immune response in tuberculosis.
PMID- 10688140
TI - Transposable element contributions to plant gene and genome evolution.
AB - Transposable elements were first discovered in plants because they can have
tremendous effects on genome structure and gene function. Although only a few or
no elements may be active within a genome at any time in any individual, the
genomic alterations they cause can have major outcomes for a species. All major
element types appear to be present in all plant species, but their quantitative
and qualitative contributions are enormously variable even between closely
related lineages. In some large-genome plants, mobile DNAs make up the majority
of the nuclear genome. They can rearrange genomes and alter individual gene
structure and regulation through any of the activities they promote:
transposition, insertion, excision, chromosome breakage, and ectopic
recombination. Many genes may have been assembled or amplified through the action
of transposable elements, and it is likely that most plant genes contain legacies
of multiple transposable element insertions into promoters. Because chromosomal
rearrangements can lead to speciating infertility in heterozygous progeny,
transposable elements may be responsible for the rate at which such
incompatibility is generated in separated populations. For these reasons,
understanding plant gene and genome evolution is only possible if we comprehend
the contributions of transposable elements.
PMID- 10688144
TI - What we can learn from the Mycobacterium tuberculosis genome sequencing projects.
AB - A major milestone in tuberculosis research occurred in June 1998 with the report
of the genomic sequence of Mycobacterium tuberculosis H37Rv. The complete
determination of the 4411529 base pairs of the M. tuberculosis genome opens
avenues for new scientific opportunities in basic science and clinical research
on tuberculosis. In this paper we will review the findings presented by the
complete genome and discuss the impact that this sequence will have on the areas
of comparative genomics, bacterial pathogenesis, and diagnostics development for
tuberculosis. Indirect benefits of the complete genome sequence are anticipated
in the areas of drug development and vaccine development as future discoveries in
bacterial pathogenesis and immunology accrue.
PMID- 10688145
TI - Global AIDS 1981-1999: the response.
PMID- 10688146
TI - Use of clinical risk assessments in evaluation of nucleic acid amplification
tests for HIV/tuberculosis.
PMID- 10688147
TI - Applying advances to the clinic and health care delivery: putting the strategies
to work.
PMID- 10688148
TI - DNA fingerprinting and contact investigation.
PMID- 10688149
TI - Community responses to HIV/TB in Canada: a discussion of issues addressed in the
HIV/TB Project of the Canadian AIDS Society.
PMID- 10688150
TI - Evaluating tuberculosis control programs: strategies, tools and models.
PMID- 10688151
TI - Who gains from international tuberculosis collaboration?
PMID- 10688152
TI - Applying advances to the developing world for TB and HIV control.
PMID- 10688153
TI - The impact of drug resistance on the global tuberculosis epidemic.
PMID- 10688154
TI - Tuberculosis preventive therapy for HIV-infected persons in less developed
countries.
PMID- 10688155
TI - Translating discoveries into control of tuberculosis in HIV-infected persons.
PMID- 10688156
TI - Defining the course of brain structural change and plasticity in schizophrenia.
AB - Recent evidence from controlled CT and MRI longitudinal studies suggests that
some cerebral ventricular enlargement and hemispheric volumetric reductions (e.g.
cerebral atrophy) may have a progressive component in patients with
schizophrenia. These studies vary in cohort composition, stage of illness
examined, duration of follow-up interval, imaging techniques used, and specific
brain regions with findings. They also conflict with earlier evidence suggesting
that schizophrenia is a neurodevelopmental disorder with brain pathological
deviance occurring prior to the illness onset. The newer brain imaging reports
may be detecting subtle brain plasticity that results from a continuing cortical
disruptive process, may be epi-phenomena caused by scanning and image analysis
artifacts or may possibly reflect systemic physiological fluctuations. Future
longitudinal studies of subjects at all stages of illness using a variety of new
technologies are needed to clarify these findings.
PMID- 10688157
TI - A differential neural response to threatening and non-threatening negative facial
expressions in paranoid and non-paranoid schizophrenics.
AB - Several studies have demonstrated impaired facial expression recognition in
schizophrenia. Few have examined the neural basis for this; none have compared
the neural correlates of facial expression perception in different schizophrenic
patient subgroups. We compared neural responses to facial expressions in 10 right
handed schizophrenic patients (five paranoid and five non-paranoid) and five
normal volunteers using functional Magnetic Resonance Imaging (fMRI). In three 5
min experiments, subjects viewed alternating 30-s blocks of black-and-white
facial expressions of either fear, anger or disgust contrasted with expressions
of mild happiness. After scanning, subjects categorised each expression. All
patients were less accurate in identifying expressions, and showed less
activation to these stimuli than normals. Non-paranoids performed poorly in the
identification task and failed to activate neural regions that are normally
linked with perception of these stimuli. They categorised disgust as either anger
or fear more frequently than paranoids, and demonstrated in response to disgust
expressions activation in the amygdala, a region associated with perception of
fearful faces. Paranoids were more accurate in recognising expressions, and
demonstrated greater activation than non-paranoids to most stimuli. We provide
the first evidence for a distinction between two schizophrenic patient subgroups
on the basis of recognition of and neural response to different negative facial
expressions.
PMID- 10688158
TI - Dopamine D2 receptor occupancy by olanzapine or risperidone in young patients
with schizophrenia.
AB - A crucial characteristic of antipsychotic medication is the occupancy of the
dopamine (DA) D2 receptor. We assessed striatal DA D2 receptor occupancy by
olanzapine and risperidone in 36 young patients [31 males, 5 females; mean age
21.1 years (16-28)] with first episode schizophrenia, using [123I]iodobenzamide
(IBZM) SPECT. The occupancy of DA D2 receptors was not significantly different
between olanzapine and risperidone. However, in subgroups of most prescribed
doses, DA D2 occupancy was higher in the risperidone 4-mg group (79%) compared to
the olanzapine 15-mg group (62%). [123I]IBZM binding ratios decreased with
olanzapine dose (r = -0.551; P < 0.01), indicating higher DA D2 receptor
occupancy with higher olanzapine dose. Akathisia and positive symptoms were
correlated with [123I]IBZM binding ratio (r = -0.442; P < 0.01; and r = -0.360; P
< 0.05, respectively). Prolactin (PRL) levels were elevated in the risperidone,
but not in the olanzapine group, at comparable D2 receptor occupancy levels. In
the olanzapine group, PRL levels were correlated with [123I]IBZM binding ratio (r
= -0.551; P < 0.01). In conclusion, both olanzapine and risperidone induce a high
striatal D2 receptor occupancy, dependent on dose and group formation. The lower
incidence of prolactin elevation with olanzapine, compared to risperidone, may
not be attributed to a lower D2 receptor occupancy.
PMID- 10688159
TI - Subtype-associated metabolite differences in the temporal lobe in schizophrenia
detected by proton magnetic resonance spectroscopy.
AB - Brain imaging studies have indicated that the medial temporal lobe functions
aberrantly in schizophrenic patients. Both diagnostic subtype and gender may
affect functional and morphologic abnormalities in this region. We investigated
subtype- and gender-associated differences in metabolites in the left medial
temporal lobe in 40 medicated schizophrenic patients by proton magnetic resonance
spectroscopy and compared findings with those in 40 healthy control subjects.
Peaks corresponding to N-acetylaspartate (NAA), choline-containing compounds
(Cho), creatine-phosphocreatine (Cr), and inositol were measured. Schizophrenic
patients showed a decrease in the NAA/Cr ratio in the left medial temporal lobe,
and patients with the disorganized subtype of illness showed significantly lower
NAA/Cr and Cho/Cr ratios than those with paranoid schizophrenia. The NAA/Cr ratio
in patients with the undifferentiated subtype also was significantly lower than
in the paranoid subtype. No significant associations were observed between
metabolite ratios and clinical symptom scores, age at onset of illness, or
gender. These findings suggest that patients with the disorganized and
undifferentiated subtypes have greater impairments in neuronal integrity or
function in the left medial temporal lobe than patients with other subtypes of
schizophrenia.
PMID- 10688160
TI - NSF boost sends the right message to Congress.
PMID- 10688162
TI - CERN claims first experimental creation of quark-gluon plasma. European
Laboratory for Particle Physics
PMID- 10688161
TI - Think globally, act cautiously.
PMID- 10688164
TI - International science council names first female president
PMID- 10688163
TI - Austria taken to court for inadequate laws on animal welfare.
PMID- 10688165
TI - NASA review leaves projects on launch pad. National Aeronautics & Space
Administration
PMID- 10688166
TI - Congress gets tough with gene therapy.
PMID- 10688167
TI - Scientists reject blame for German genome shortfall.
PMID- 10688168
TI - Clinton's farewell gift to US science agencies.
PMID- 10688169
TI - Stanford accelerator takes lead in race to quantify CP violation
PMID- 10688170
TI - Charm, not tact, aided pioneer in fight for physics
PMID- 10688171
TI - Will cell alliance breed bureaucracy and leave contributors out?
PMID- 10688172
TI - Proteins suggest form of their own database.
PMID- 10688173
TI - Debating controversies can enhance creativity.
PMID- 10688174
TI - Time for an aspirin
PMID- 10688175
TI - The myth of well-funded German research.
PMID- 10688177
TI - Only connect
PMID- 10688176
TI - Laying down the law.
PMID- 10688179
TI - Dynamics of Jupiter's atmosphere
PMID- 10688178
TI - Guilt-by-association goes global.
PMID- 10688180
TI - Neuroscience. Images of lost sleep.
PMID- 10688181
TI - Enzyme evolution. Design by necessity.
PMID- 10688183
TI - Antarctica. Stirring the icy waters
PMID- 10688182
TI - Developmental genetics. A Hox by any other name.
PMID- 10688184
TI - Cell biology. Which way is up?
PMID- 10688185
TI - Flight restores fight in crickets.
PMID- 10688186
TI - The ACE gene and muscle performance.
PMID- 10688187
TI - A new model for protein stereospecificity.
PMID- 10688188
TI - 'Ghost' alleles of the Mauritius kestrel.
PMID- 10688189
TI - Directed evolution of new catalytic activity using the alpha/beta-barrel
scaffold.
AB - In biological systems, enzymes catalyse the efficient synthesis of complex
molecules under benign conditions, but widespread industrial use of these
biocatalysts depends crucially on the development of new enzymes with useful
catalytic functions. The evolution of enzymes in biological systems often
involves the acquisition of new catalytic or binding properties by an existing
protein scaffold. Here we mimic this strategy using the most common fold in
enzymes, the alpha/beta-barrel, as the scaffold. By combining an existing binding
site for structural elements of phosphoribosylanthranilate with a catalytic
template required for isomerase activity, we are able to evolve
phosphoribosylanthranilate isomerase activity from the scaffold of indole-3
glycerol-phosphate synthase. We find that targeting the catalytic template for in
vitro mutagenesis and recombination, followed by in vivo selection, results in a
new phosphoribosylanthranilate isomerase that has catalytic properties similar to
those of the natural enzyme, with an even higher specificity constant. Our
demonstration of divergent evolution and the widespread occurrence of the
alpha/beta-barrel suggest that this scaffold may be a fold of choice for the
directed evolution of new biocatalysts.
PMID- 10688190
TI - A comprehensive analysis of protein-protein interactions in Saccharomyces
cerevisiae.
AB - Two large-scale yeast two-hybrid screens were undertaken to identify protein
protein interactions between full-length open reading frames predicted from the
Saccharomyces cerevisiae genome sequence. In one approach, we constructed a
protein array of about 6,000 yeast transformants, with each transformant
expressing one of the open reading frames as a fusion to an activation domain.
This array was screened by a simple and automated procedure for 192 yeast
proteins, with positive responses identified by their positions in the array. In
a second approach, we pooled cells expressing one of about 6,000 activation
domain fusions to generate a library. We used a high-throughput screening
procedure to screen nearly all of the 6,000 predicted yeast proteins, expressed
as Gal4 DNA-binding domain fusion proteins, against the library, and
characterized positives by sequence analysis. These approaches resulted in the
detection of 957 putative interactions involving 1,004 S. cerevisiae proteins.
These data reveal interactions that place functionally unclassified proteins in a
biological context, interactions between proteins involved in the same biological
function, and interactions that link biological functions together into larger
cellular processes. The results of these screens are shown here.
PMID- 10688191
TI - Observation of moist convection in Jupiter's atmosphere. Galileo Imaging Team
AB - The energy source driving Jupiter's active meteorology is not understood. There
are two main candidates: a poorly understood internal heat source and sunlight.
Here we report observations of an active storm system possessing both lightning
and condensation of water. The storm has a vertical extent of at least 50 km and
a length of about 4,000 km. Previous observations of lightning on Jupiter have
revealed both its frequency of occurrence and its spatial distribution, but they
did not permit analysis of the detailed cloud structure and its dynamics. The
present observations reveal the storm (on the day side of the planet) at the same
location and within just a few hours of a lightning detection (on the night
side). We estimate that the total vertical transport of heat by storms like the
one observed here is of the same order as the planet's internal heat source. We
therefore conclude that moist convection-similar to large clusters of
thunderstorm cells on the Earth-is a dominant factor in converting heat flow into
kinetic energy in the jovian atmosphere.
PMID- 10688192
TI - Moist convection as an energy source for the large-scale motions in Jupiter's
atmosphere. Galileo Imaging Team
AB - Jupiter's dominant large-scale weather patterns (dimensions approximately 10,000
km) are zonal jets and long-lived ovals. The jets have been flowing east and west
at constant speeds of up to 180 m s(-1) for over 100 years. These jets receive
energy from small-scale eddies, which pump eastward momentum into the eastward
jets and westward momentum into the westward jets. This momentum transfer was
predicted by numerical models before it was observed on Jupiter. The large ovals
roll between the jets in an anticyclonic direction-clockwise in the northern
hemisphere and counterclockwise in the southern hemisphere--where they regularly
assimilate small anticyclonic eddies. But from where the eddies receive their
energy has been an open question. Here we argue that the eddies, which ultimately
drive both the jets and the ovals, receive their energy from moist convection.
This hypothesis is consistent with observations of jovian lightning, which is an
indicator of moist convection. It also explains the anticyclonic rotation and
poleward drift of the eddies, and suggests patterns of upwelling and downwelling
that resemble the patterns of large-scale axisymmetric overturning in the Earth's
atmosphere.
PMID- 10688193
TI - Structure and bandgap closure in dense hydrogen
AB - The possibility that steadily compressed hydrogen might undergo a transition from
a proton-paired insulator to a monatomic metal was first suggested in 1935. But
experimental realization of metallic hydrogen in solid form has remained elusive,
despite studies at pressures as high as 342 GPa. The pairing structure is known
to be robust (from the persistence of its associated vibron mode), leading to the
suggestion of an alternative route to the metallic state, involving a band
overlap transition in which the pairing is preserved. Here we report density
functional calculations within the local density approximation that predict a
range of densities for hydrogen where a paired or molecular metallic state may be
energetically preferred. The transition to this metallic state is naturally
associated with the closing of an overall bandgap; but the pressures required to
effect the transition are shown to change significantly when the gaps are
corrected by approximate inclusion of many-electron effects. The implication is
that a complete resolution of the structural and phase problem in dense hydrogen
may require methods beyond the local density approximation.
PMID- 10688194
TI - Direct measurement of electrical transport through DNA molecules.
AB - Attempts to infer DNA electron transfer from fluorescence quenching measurements
on DNA strands doped with donor and acceptor molecules have spurred intense
debate over the question of whether or not this important biomolecule is able to
conduct electrical charges. More recently, first electrical transport
measurements on micrometre-long DNA 'ropes', and also on large numbers of DNA
molecules in films, have indicated that DNA behaves as a good linear conductor.
Here we present measurements of electrical transport through individual 10.4-nm
long, double-stranded poly(G)-poly(C) DNA molecules connected to two metal
nanoelectrodes, that indicate, by contrast, large-bandgap semiconducting
behaviour. We obtain nonlinear current-voltage curves that exhibit a voltage gap
at low applied bias. This is observed in air as well as in vacuum down to
cryogenic temperatures. The voltage dependence of the differential conductance
exhibits a peak structure, which is suggestive of the charge carrier transport
being mediated by the molecular energy bands of DNA.
PMID- 10688195
TI - Non-destructive determination of local strain with 100-nanometre spatial
resolution
AB - Structure sizes of approximately 180 nm are now standard in microelectronics, and
state-of-the-art fabrication techniques can reduce these to just a few tens of
nanometres. But at these length scales, the strain induced at interfaces can
locally distort the crystal lattice, which may in turn affect device performance
in an unpredictable way. A means of non-destructively characterizing such strain
fields with high spatial resolution and sensitivity is therefore highly
desirable. One approach is to use Raman spectroscopy, but this is limited by the
intrinsic approximately 0.5-microm resolution limit of visible light probes.
Techniques based on electron-beam diffraction can achieve the desired nanometre
scale resolution. But either they require complex sample preparation procedures
(which may alter the original strain field) or they are sensitive to distortional
(but not dilational) strain within only the top few tens of nanometres of the
sample surface. X-rays, on the other hand, have a much greater penetration depth,
but have not hitherto achieved strain analysis with sub-micrometre resolution.
Here we describe a magnifying diffraction imaging procedure for X-rays which
achieves a spatial resolution of 100nm in one dimension and a sensitivity of 10(
4) for relative lattice variations. We demonstrate the suitability of this
procedure for strain analysis by measuring the strain depth profiles beneath
oxidized lines on silicon crystals.
PMID- 10688196
TI - Air entrapment in coatings by way of a tip-streaming meniscus
AB - Entrapment of small air bubbles is a problem for continuous liquid-film coatings
processes. The coating of any surface requires that the surrounding air in
contact with it be displaced by an advancing liquid interface. Studies of dynamic
wetting suggest that if the interface motion is too rapid, the air is not
completely removed and it becomes entrained in the coating material. This
process, which can lead to undesirable flaws in the form of bubbles, blemishes or
voids, limits the speed at which the substrate can be moved in the production of
uniform precision coatings. However, the entrapment process is not understood in
detail. Here we report an experimental investigation of air entrapment in high
speed coating operations. Tip streaming--a phenomenon well known in
emulsification technology, involving the ejection of a fine filament from the
cusped interface between two immiscible fluids--is shown to be the precursor of
air entrainment. We demonstrate that tip-streaming air filaments emanating from
the contact zone of a dynamic liquid interface give rise to minute (approximately
10 microm) bubbles.
PMID- 10688197
TI - Water exchange between the subglacial Lake Vostok and the overlying ice sheet
AB - It has now been known for several years that a 200-km-long lake, called Lake
Vostok, lies beneath the ice sheet on which sits Vostok Station in Antarctica.
The conditions at the base of the ice sheet above this subglacial lake can
provide information about the environment within the lake, including the
likelihood that it supports life. Here we present an analysis of the ice-sheet
structure from airborne 60-MHz radar studies, which indicates that distinct zones
of basal ice loss and accretion occur at the ice-water interface. Subglacial
melting and net ice loss occur in the north of the lake and across its 200-km
long western margin, whereas about 150 m of ice is gained by subglacial freezing
in the south. This indicates that significant quantities of water are exchanged
between the base of the ice sheet and the lake waters, which will enrich the lake
with gas hydrates, cause sediment deposition and encourage circulation of the
lake water.
PMID- 10688198
TI - Stable-isotope probing as a tool in microbial ecology.
AB - Microorganisms are responsible for driving the biogeochemical cycling of elements
on Earth. Despite their importance and vast diversity, the taxonomic identity of
the microorganisms involved in any specific process has usually been confined to
that small fraction of the microbiota that has been isolated and cultivated. The
recent coupling of molecular biological methods with stable-isotope abundance in
biomarkers has provided a cultivation-independent means of linking the identity
of bacteria with their function in the environment. Here we show that 13C-DNA,
produced during the growth of metabolically distinct microbial groups on a 13C
enriched carbon source, can be resolved from 12C-DNA by density-gradient
centrifugation. DNA isolated from the target group of microorganisms can be
characterized taxonomically and functionally by gene probing and sequence
analysis. Application of this technique to investigate methanol-utilizing
microorganisms in soil demonstrated the involvement of members of two
phylogenetically distinct groups of eubacteria; the alpha-proteobacterial and
Acidobacterium lineages. Stable-isotope probing thus offers a powerful new
technique for identifying microorganisms that are actively involved in specific
metabolic processes under conditions which approach those occurring in situ.
PMID- 10688199
TI - Ancestral chloroplast genome in Mesostigma viride reveals an early branch of
green plant evolution.
AB - Sequence comparisons suggest that all living green plants belong to one of two
major phyla: Streptophyta (land plants and their closest green algal relatives,
the charophytes); and Chlorophyta (the rest of green algae). Because no green
algae are known that pre-date the Streptophyta/Chlorophyta split, and also
because the earliest diverging green algae show considerable morphological
variation, the nature of the unicellular flagellate ancestor of the two green
plant phyla is unknown. Here we report that the flagellate Mesostigma viride
belongs to the earliest diverging green plant lineage discovered to date. We have
sequenced the entire chloroplast DNA (118,360 base pairs) of this green alga and
have conducted phylogenetic analyses of sequences derived from this genome.
Mesostigma represents a lineage that emerged before the divergence of the
Streptophyta and Chlorophyta, a position that is supported by several features of
its chloroplast DNA. The structure and gene organization of this genome indicate
that chloroplast DNA architecture has been extremely well conserved in the line
leading to land plants.
PMID- 10688200
TI - Pattern recognition and active vision in chickens.
AB - Recognition of objects or environmental landmarks is problematic because
appearance can vary widely depending on illumination, viewing distance, angle of
view and so on. Storing a separate image or 'template' for every possible view
requires vast numbers to be stored and scanned, has a high probability of
recognition error and appears not to be the solution adopted by primates.
However, some invertebrate template matching systems can achieve recognition by
'active vision' in which the animal's own behaviour is used to achieve a fit
between template and object, for example by repeatedly following a set path.
Recognition is thus limited to views from the set path but achieved with a
minimal number of templates. Here we report the first evidence of similar active
vision in a bird, in the form of locomotion and individually distinct head
movements that give the eyes a similar series of views on different occasions.
The hens' ability to recognize objects is also found to decrease when their
normal paths are altered.
PMID- 10688201
TI - Altered brain response to verbal learning following sleep deprivation.
AB - The effects of sleep deprivation on the neural substrates of cognition are poorly
understood. Here we used functional magnetic resonance imaging to measure the
effects of 35 hours of sleep deprivation on cerebral activation during verbal
learning in normal young volunteers. On the basis of a previous hypothesis, we
predicted that the prefrontal cortex (PFC) would be less responsive to cognitive
demands following sleep deprivation. Contrary to our expectations, however, the
PFC was more responsive after one night of sleep deprivation than after normal
sleep. Increased subjective sleepiness in sleep-deprived subjects correlated
significantly with activation of the PFC. The temporal lobe was activated after
normal sleep but not after sleep deprivation; in contrast, the parietal lobes
were not activated after normal sleep but were activated after sleep deprivation.
Although sleep deprivation significantly impaired free recall compared with the
rested state, better free recall in sleep-deprived subjects was associated with
greater parietal lobe activation. These findings show that there are dynamic,
compensatory changes in cerebral activation during verbal learning after sleep
deprivation and implicate the PFC and parietal lobes in this compensation.
PMID- 10688202
TI - The organizer factors Chordin and Noggin are required for mouse forebrain
development.
AB - In mice, there is evidence suggesting that the development of head and trunk
structures is organized by distinctly separated cell populations. The head
organizer is located in the anterior visceral endoderm (AVE) and the trunk
organizer in the node and anterior primitive streak. In amphibians, Spemann's
organizer, which is homologous to the node, partially overlaps with anterior
endoderm cells expressing homologues of the AVE markers cerberus, Hex and Hesx1.
For mice, this raises the question of whether the AVE and node are independent of
each other, as suggested by their anatomical separation, or functionally
interdependent as is the case in amphibians. Chordin and Noggin are secreted bone
morphogenetic protein (BMP) antagonists expressed in the mouse node, but not in
the AVE. Here we show that mice double-homozygous mutants that are for chordin
and noggin display severe defects in the development of the prosencephalon. The
results show that BMP antagonists in the node and its derivatives are required
for head development.
PMID- 10688203
TI - Maintenance of functional equivalence during paralogous Hox gene evolution.
AB - Biological diversity is driven mainly by gene duplication followed by mutation
and selection. This divergence in either regulatory or protein-coding sequences
can result in quite different biological functions for even closely related
genes. This concept is exemplified by the mammalian Hox gene complex, a group of
39 genes which are located on 4 linkage groups, dispersed on 4 chromosomes. The
evolution of this complex began with amplification in cis of a primordial Hox
gene to produce 13 members, followed by duplications in trans of much of the
entire unit. As a consequence, Hox genes that occupy the same relative position
along the 5' to 3' chromosomal coordinate (trans-paralogous genes) share more
similarity in sequence and expression pattern than do adjacent Hox genes on the
same chromosome. Studies in mice indicate that although individual family members
may have unique biological roles, they also share overlapping functions with
their paralogues. Here we show that the proteins encoded by the paralogous genes,
Hoxa3 and Hoxd3, can carry out identical biological functions, and that the
different roles attributed to these genes are the result of quantitative
modulations in gene expression.
PMID- 10688204
TI - The genome sequence of the food-borne pathogen Campylobacter jejuni reveals
hypervariable sequences.
AB - Campylobacter jejuni, from the delta-epsilon group of proteobacteria, is a
microaerophilic, Gram-negative, flagellate, spiral bacterium-properties it shares
with the related gastric pathogen Helicobacter pylori. It is the leading cause of
bacterial food-borne diarrhoeal disease throughout the world. In addition,
infection with C. jejuni is the most frequent antecedent to a form of
neuromuscular paralysis known as Guillain-Barre syndrome. Here we report the
genome sequence of C. jejuni NCTC11168. C. jejuni has a circular chromosome of
1,641,481 base pairs (30.6% G+C) which is predicted to encode 1,654 proteins and
54 stable RNA species. The genome is unusual in that there are virtually no
insertion sequences or phage-associated sequences and very few repeat sequences.
One of the most striking findings in the genome was the presence of hypervariable
sequences. These short homopolymeric runs of nucleotides were commonly found in
genes encoding the biosynthesis or modification of surface structures, or in
closely linked genes of unknown function. The apparently high rate of variation
of these homopolymeric tracts may be important in the survival strategy of C.
jejuni.
PMID- 10688205
TI - Shiga-like toxins are neutralized by tailored multivalent carbohydrate ligands.
AB - The diseases caused by Shiga and cholera toxins account for the loss of millions
of lives each year. Both belong to the clinically significant subset of bacterial
AB5 toxins consisting of an enzymatically active A subunit that gains entry to
susceptible mammalian cells after oligosaccharide recognition by the B5
homopentamer. Therapies might target the obligatory oligosaccharide-toxin
recognition event, but the low intrinsic affinity of carbohydrate-protein
interactions hampers the development of low-molecular-weight inhibitors. The
toxins circumvent low affinity by binding simultaneously to five or more cell
surface carbohydrates. Here we demonstrate the use of the crystal structure of
the B5 subunit of Escherichia coli O157:H7 Shiga-like toxin I (SLT-I) in complex
with an analogue of its carbohydrate receptor to design an oligovalent, water
soluble carbohydrate ligand (named STARFISH), with subnanomolar inhibitory
activity. The in vitro inhibitory activity is 1-10-million-fold higher than that
of univalent ligands and is by far the highest molar activity of any inhibitor
yet reported for Shiga-like toxins I and II. Crystallography of the
STARFISH/Shiga-like toxin I complex explains this activity. Two trisaccharide
receptors at the tips of each of five spacer arms simultaneously engage all five
B subunits of two toxin molecules.
PMID- 10688206
TI - How self-tolerance and the immunosuppressive drug FK506 prevent B-cell
mitogenesis.
AB - Therapy for transplant rejection, autoimmune disease and allergy must target
mature lymphocytes that have escaped censoring during their development. FK506
and cyclosporin are immunosuppressants which block three antigen-receptor
signalling pathways (NFAT, NFkappaB and JNK), through inhibition of calcineurin,
and inhibit mature lymphocyte proliferation to antigen. Neither drug induces long
lived tolerance in vivo, however, necessitating chronic use with adverse side
effects. Physiological mechanisms of peripheral tolerance to self-antigens
provide an opportunity to emulate these processes pharmacologically. Here we use
gene-expression arrays to provide a molecular explanation for the loss of
mitogenic response in peripheral B-cell anergy, one aspect of immunological
tolerance. Self-antigen induces a set of genes that includes negative regulators
of signalling and transcription but not genes that promote proliferation. FK506
interferes with calcium-dependent components of the tolerance response and blocks
an unexpectedly small fraction of the activation response. Many genes that were
not previously connected to self-tolerance are revealed, and our findings provide
a molecular fingerprint for the development of improved immunosuppressants that
prevent lymphocyte activation without blocking peripheral tolerance.
PMID- 10688207
TI - Localization of apical epithelial determinants by the basolateral PDZ protein
Scribble.
AB - The generation of membrane domains with distinct protein constituents is a
hallmark of cell polarization. In epithelia, segregation of membrane proteins
into apical and basolateral compartments is critical for cell morphology, tissue
physiology and cell signalling. Drosophila proteins that confer apical membrane
identity have been found, but the mechanisms that restrict these determinants to
the apical cell surface are unknown. Here we show that a laterally localized
protein is required for the apical confinement of polarity determinants.
Mutations in Drosophila scribble (scrib), which encodes a multi-PDZ (PSD-95,
Discs-large and ZO-1) and leucine-rich-repeat protein, cause aberrant cell shapes
and loss of the monolayer organization of embryonic epithelia. Scrib is localized
to the epithelial septate junction, the analogue of the vertebrate tight
junction, at the boundary of the apical and basolateral cell surfaces. Loss of
scrib function results in the misdistribution of apical proteins and adherens
junctions to the basolateral cell surface, but basolateral protein localization
remains intact. These phenotypes can be accounted for by mislocalization of the
apical determinant Crumbs. Our results show that the lateral domain of epithelia,
particularly the septate junction, functions in restricting apical membrane
identity and correctly placing adherens junctions.
PMID- 10688208
TI - A tripeptide 'anticodon' deciphers stop codons in messenger RNA.
AB - The two translational release factors of prokaryotes, RF1 and RF2, catalyse the
termination of polypeptide synthesis at UAG/UAA and UGA/UAA stop codons,
respectively. However, how these polypeptide release factors read both non
identical and identical stop codons is puzzling. Here we describe the basis of
this recognition. Swaps of each of the conserved domains between RF1 and RF2 in
an RF1-RF2 hybrid led to the identification of a domain that could switch
recognition specificity. A genetic selection among clones encoding random
variants of this domain showed that the tripeptides Pro-Ala-Thr and Ser-Pro-Phe
determine release-factor specificity in vivo in RF1 and RF2, respectively. An in
vitro release study of tripeptide variants indicated that the first and third
amino acids independently discriminate the second and third purine bases,
respectively. Analysis with stop codons containing base analogues indicated that
the C2 amino group of purine may be the primary target of discrimination of G
from A. These findings show that the discriminator tripeptide of bacterial
release factors is functionally equivalent to that of the anticodon of transfer
RNA, irrespective of the difference between protein and RNA.
PMID- 10688209
TI - Pancreatic trauma--injuries to the pancreas and pancreatic duct.
PMID- 10688210
TI - Organisation of a trauma registry in a regional Greek university hospital: the
first two years experience.
AB - OBJECTIVE: To design and implement a hospital trauma registry so as to be able to
monitor the care of injured patients. SETTING: Teaching hospital, Greece.
SUBJECTS: All patients admitted with trauma from January 1997. MAIN OUTCOME
MEASURES: Design of a suitable form, establishment of inclusion and exclusion
criteria, injury severity scoring, finding money and personnel, and getting
suitable computer hardware and software for reliable collection and analysis of
data. RESULTS: We experienced great difficulty in getting funding, so were unable
to employ dedicated staff to collect the data, though we have had a part-time
secretary to coordinate the registry whose salary has been paid by a
pharmaceutical company. We have to rely on junior doctors to collect the data,
which works well when they are enthusiastic (though not all are). We decided to
use the data collection form used by the UK Trauma Network. We are trying to
collect sufficient data to code severity by more than one system, but at present
this is causing problems because busy nurses and doctors do not like filling in
forms. Software has also been a problem as most of it is in English and
translation is a considerable workload. The calculations are still being done
manually while we work with two computer programmers to develop our own. We have
submitted a research protocol to the Ministry of Health which has been accepted
and this will guarantee our expenses for the next two years. CONCLUSIONS:
Implementing a philosophy of continuous quality improvement is never easy, and we
expect funding to be a permanent source of anxiety. Our progress so far has been
good, but not as good as we hoped; however, we are optimistic that as people see
the value of continuous monitoring of the system they will become more
enthusiastic and supportive.
PMID- 10688211
TI - Cardiac injuries: a ten-year experience.
AB - OBJECTIVE: To present our experience of cardiac injuries treated at one Swedish
emergency department in the 10 years 1988-97. DESIGN: Retrospective study.
SETTING: Teaching hospital. SUBJECTS: 11 patients (9 men and 2 women, mean age 33
years, range 19-54); in 7 they were penetrating injuries and in 4 blunt. MAIN
OUTCOME MEASURES: Morbidity and mortality. RESULTS: The mechanisms of injury were
stab wound (n = 7), and car crash, fall, boat crash, and abuse (n = 1 each); drug
or alcohol misuse played a part in all those with penetrating injuries. The
penetrating wounds involved the left ventricle (n = 3), the right ventricle (n =
2), and the pericardium (n = 2). All 5 patients with ventricular wounds presented
with cardiac tamponade, in 1 of whom it was fatal (he bled to death during
emergency thoracotomy). The main complications were anoxic brain damage and
postpericardiotomy syndrome (1 each). There was no case of myocardial concussion.
CONCLUSION: Our data reflect the Swedish experience of heart trauma: there are
few cases, alcohol and drug misuse is the principal risk factor, and there were
no gunshot wounds.
PMID- 10688212
TI - Outcome of lung trauma.
AB - OBJECTIVE: To find out whether we could manage critical pulmonary haemorrhages in
penetrating injuries, and to report our experience with blunt trauma of the lung.
DESIGN: Retrospective study. SETTING: Teaching hospital, Sweden. SUBJECTS: 81
patients who presented with pulmonary injuries during the period January 1988
December 1997; 6 were penetrating and 75 blunt. RESULTS: There was only one
patient with an isolated lung contusion. The remaining was divided into 2 groups:
those with pulmonary contusion and thoracic lesions (n = 32), and those with
pulmonary contusion and extrathoracic lesions (n = 42). Four patients in the
penetrating group were shocked and required urgent operations; emergency room
thoracotomy (n = 1), urgent thoracotomy (n = 2), and urgent thoracoabdominal
exploration (n = 1) were done successfully. We correlated grade of lung injury
[American Association for the Surgery of Trauma-Abbreviated Injury Scale (AIS)]
with mortality. All patients with penetrating injuries survived without serious
consequences. There were a mean (SD), of 6 (2) injuries/patient in those with
extrathoracic injuries compared with 3 (1) injuries/patient in the group with
thoracic lesions (p < 0.001). The corresponding hospital mortality was 6/42 (19%)
mainly as a result of the central nervous system lesions (4/6) compared with
0/32. The mean (SD) Injury Severity Score (ISS) was 9.3 (4.8) in patients with
thoracic lesions compared with 24.1 (14.7) in patients with extrathoracic lesions
(p < 0.0001), and 14.9 (9.5) in all survivors compared with 49.9 (13.6) among
those who died (p < 0.0001). CONCLUSIONS: An excellent outcome can be achieved
managing penetrating injuries of the lung by an aggressive approach and urgent
surgical intervention even when emergency room thoracotomy is essential.
Pulmonary contusion is considered to be a relatively benign lesion that does not
add to the morbidity or mortality in patients with blunt chest trauma. These data
may help to decrease the obsession with pulmonary contusion in patients with
chest trauma, with or without extrathoracic lesions, and avoid many unnecessary
computed tomograms of the chest.
PMID- 10688213
TI - Prognostic factors in patients with differentiated thyroid carcinoma.
AB - OBJECTIVE: To study the prognostic factors in patients with differentiated
thyroid carcinoma. DESIGN: Retrospective analysis. SETTING: University hospital,
Germany. PATIENTS: 139 consecutive patients who underwent surgery for follicular
(n = 42) and papillary thyroid carcinoma (n = 97). MAIN OUTCOME MEASURES:
Survival rate, type of operation (systematic lymphadenectomy or no
lymphadenectomy). RESULTS: Median observation time was 72 months (range 1-203).
The 5 and 10 year survival rates in patients with papillary carcinoma were 92%
and 89% respectively, and in those with follicular carcinoma 88% and 80%,
respectively. Prognostic factors for papillary carcinoma were distant metastases,
age, and extrathyroidal growth, and for follicular carcinoma they were distant
metastases, extrathyroidal extension, and multifocal growth. The Union
International contre le Cancer and European Organisation for Research and
Treatment of Cancer scores and the age, grade, extent and size score were all
highly significant. The extent of lymphadenectomy, primary or secondary
thyroidectomy, and partial or total thyroidectomy did not influence survival.
CONCLUSION: Staging and score systems may be helpful in calculating prognosis in
differentiated thyroid carcinoma, but the benefit of systematic lymphadenectomy
remains controversial.
PMID- 10688214
TI - Clinical and histological differences in anaplastic thyroid carcinoma.
AB - OBJECTIVE: To report our experience in patients with anaplastic thyroid carcinoma
and try to establish differences between cases in which the histological study
showed that there was an associated thyroid carcinoma and those that were
strictly anaplastic or pure. DESIGN: Retrospective study. SETTING: University
hospital, Spain. SUBJECTS: 14 patients with anaplastic thyroid cancer treated
over a period of 26 years; 7 presented with associated thyroid tumours and 7 were
pure. MEAN OUTCOME MEASURES: Clinical data (age, sex, symptoms), treatment,
histological study (associated thyroid disease, spread, involved lymph nodes) and
follow-up. RESULTS: 13 of the 14 tumours had spread locally. 5 patients were
treated by total thyroidectomy, 3 subtotal thyroidectomy, 5 excision of the
tumour, and 1 patient had a biopsy alone. There were associated thyroid tumours
in 7 cases: 2 follicular, 2 tall cell papillary, 1 solid papillary, 1 medullary
and 1 Hurthle cell tumour. 12 patients died. Another 2 are still alive having
survived 61 and 70 months respectively, both with associated anaplastic cancers
(follicular and solid). The mean survival was 14 months (24 for associated
anaplastic carcinoma and 4 for pure anaplastic carcinoma). CONCLUSION: There is a
subgroup of anaplastic cancers in which a better differentiated thyroid carcinoma
coexists with the anaplastic carcinoma. The prognosis in this subgroup is better
than that for primary pure anaplastic carcinoma.
PMID- 10688215
TI - Upper gastrointestinal contrast study in the management of small bowel
obstruction--a prospective randomised study.
AB - OBJECTIVE: To find out whether contrast radiography helps to resolve small bowel
obstruction. DESIGN: Prospective randomised trial. SETTING: University hospital,
Norway. SUBJECTS: 98 consecutive patients with symptoms of small bowel
obstruction and a plain abdominal radiograph that confirmed the diagnosis.
INTERVENTIONS: The patients were randomly allocated to receive a mixture of
barium and sodium diatrizoate (Gastrografin) (n = 48) or not (n = 50). Both
groups were followed up clinically and by repeated abdominal films. MAIN OUTCOME
MEASURES: Non-operative resolution of small bowel obstruction; number of patients
with strangulated bowel; bowel resections; mortality; complications; hospital
stay; and time from admission to operation. RESULTS: No significant differences
were observed between the groups in the incidence of non-operative resolution
(31/48 in contrast group, 35/50 in control group, OR: 0.89), strangulation
obstruction (1/48 in contrast group, 4/50 in control group, OR: 0.24), bowel
resection (3/48 in contrast group, 4/50 in control group, OR: 0.76),
complications (8/48 in contrast group, 5/50 in control group, OR: 1.80),
mortality (3/48 in contrast group, 1/50 in control group, OR: 3.26), and hospital
stay (0-7 days: 34/48 in contrast group, 38/50 in control group, p = 0.95). The
contrast group had a shorter interval between admission and operation than the
control group (0-24 hours: 12/48 in contrast group, 3/50 in control group, p =
0.005). CONCLUSION: The contrast examination did not contribute to the resolution
of small bowel obstruction.
PMID- 10688216
TI - Open management of the abdomen and planned reoperations in severe bacterial
peritonitis.
AB - OBJECTIVE: To assess the results of open management of the abdomen and planned re
operations in severe bacterial peritonitis after perforation or anastomotic
disruption of the digestive tract. DESIGN: Retrospective study. SETTING:
University Hospital, The Netherlands. SUBJECTS: 67 consecutive patients.
INTERVENTIONS: Open management of the abdomen and planned reoperations. MAIN
OUTCOME MEASURES: Hospital morbidity and mortality, long-term follow-up. RESULTS:
38 patients developed multiple organ failure (MOF), but 29 needed only
ventilatory and inotropic support. The mean number of re-operations was nine. 16
patients developed severe bleeding and 16 fistulas. In-hospital mortality was 42%
(n = 28). Long-term morbidity, particularly the number of abdominal wall defects
(n = 10), was considerable. CONCLUSION: Despite open management of the abdomen
and planned re-operations, mortality of severe bacterial peritonitis still
continues to be too high, and both short and long-term morbidity are appreciable.
The value of open management of the abdomen and planned re-operations rests only
on the clinical observation that other conventional surgical treatments of severe
bacterial peritonitis often fail.
PMID- 10688217
TI - Transoral application of EEA stapler after subtotal oesophagectomy.
AB - OBJECTIVE: To describe a new transoral technique of cervical oesophagogastric and
oesophagojejunal anastomoses using the EEA stapler. DESIGN: Prospective clinical
study. SETTING: University Hospital, Bratislava, Slovakia. SUBJECTS: Two patients
with squamous cell carcinoma of the middle and distal third of the oesophagus.
INTERVENTIONS: Transhiatal subtotal oesophagectomy without thoracotomy, and
cervical oesophageal anastomosis by transoral EEA stapling. MAIN OUTCOME
MEASURES: Morbidity and mortality. RESULTS: Transoral stapling was successful in
both patients with no anastomotic leaks. The patients were discharged on the 14th
and 21st postoperative days, respectively. CONCLUSIONS: Transoral stapling of the
cervical anastomosis gave good results in two patients. More development and
evaluation are needed.
PMID- 10688218
TI - Inflammatory fibroid polyp and Helicobacter pylori. Aetiology or coincidence?
AB - OBJECTIVE: To evaluate our incidence of inflammatory fibroid polyps, compare our
experience with that of others, and to analyze the possible pathophysiological
and aetiological factors. DESIGN: Retrospective review. SETTING: Teaching
hospital. MATERIAL: All histopathological slides of the gastrointestinal tract.
MAIN OUTCOME MEASURES: Incidence and treatment in our Medical Center and
elsewhere. RESULTS: We could find only one case of inflammatory fibroid polyp, an
estimated incidence of 1/4000. Between 1987-1996 only 331 were reported
elsewhere, most of which (293, 88.5%), were located in the stomach. CONCLUSION:
Primary mucosal damage can expose the stroma to several irritants (chemical,
mechanical and biological), that may subsequently cause inflammatory fibroid
polyps in certain people.
PMID- 10688219
TI - Long term results of lateral pancreaticojejunostomy for chronic alcoholic
pancreatitis.
AB - OBJECTIVE: To assess our long term results of lateral pancreaticojejunostomy in
patients with alcoholic pancreatitis. DESIGN: Retrospective study. SETTING:
University hospital, France. SUBJECTS: 57 patients (48 men, 9 women, mean (SD)
age 46 (7) years who required surgical treatment of chronic alcoholic
pancreatitis between January 1977 and October 1995. INTERVENTIONS: Lateral
pancreaticojejunostomy with or without another procedure. Outcome classified as
excellent, good, fair, or poor. MAIN OUTCOME MEASURES: Postoperative morbidity
and mortality; relief of pain; reduction in use of analgesics and exocrine
supplements; effect on exocrine and endocrine insufficiency; and return to paid
work. RESULTS: There were no postoperative deaths and no pancreatic fistulae, but
there were 17 other postoperative complications (30%). Median follow up was 65
months (range 8-206), during which 12 patients died (21%). Result was judged
excellent in 16 (28%), good in 27 (47%), fair in 5 (9%), and poor in 9 (16%).
Pain control was significantly improved, analgesic usage decreased, less
pancreatic enzyme supplementation was required, and 25 patients returned to paid
work (p = 0.0001 in each case). Exocrine and endocrine function remained stable.
The results were better if the patient gave up misusing alcohol (p = 0.03) and if
the operation was done within 4 years of the development of pancreatitis (p =
0.03). CONCLUSIONS: Lateral pancreaticojejunostomy is a safe procedure that can
improve functional outcome in patients with chronic alcoholic pancreatitis, and
does not worsen pancreatic function.
PMID- 10688220
TI - Operative monitoring of hand and axillary temperature during endoscopic superior
thoracic sympathectomy for the treatment of palmar hyperhidrosis.
AB - OBJECTIVE: To find out how much the temperature in the palm rises after upper
thoracic sympathectomy for palmar hyperhidrosis, and correlate the temperature
with the outcome. DESIGN: Retrospective study. SETTING: University hospital,
Spain. SUBJECTS: 73 patients (34 women and 39 men, age range 16-42 years, mean
26) who were operated for palmar hyperhidrosis between 1 January 1995 and 31
December 1997. INTERVENTIONS: Bilateral thoracic endoscopic sympathectomy during
which the temperature was monitored on the skin of both axillae and thenar
eminences, and in the oesophagus. MAIN OUTCOME MEASURES: Morbidity, alleviation
of hyperhidrosis, recurrence rate, and differences in temperature
postoperatively. RESULTS: There was minor bleeding during operation in 25 cases
(34%), but in only 4 was it sufficient to require insertion of a drain; 2
patients developed transient Homer's syndrome; but the most common complication
was compensatory hyperhidrosis (n = 52, 71%). In only 5 was this other than mild
and required treatment with aluminium chloride in ethanol 25%. Palmar
hyperhidrosis was alleviated in all cases, axillary sweating was considerably
improved, and there was improvement in the feet in 56 (77%). There were 5
recurrences, all on the right side, during a mean follow up of 9 months (range 2
36), but in no case was the sweating severe. In almost all cases the temperature
of the palm was less than that of the axilla before operation by a mean (SD) of
0.9 (0.3) degrees C. The rise in temperature varied from 1.7 (0.4) degrees C to
2.6 (0.4) degrees C. In the 5 patients who developed recurrences the increase was
less (0.5 (0.4) degrees C). CONCLUSION: Thoracic endoscopic sympathectomy is
safe, simple, and effective in treating palmar hyperhidrosis that has not
responded to conservative treatment. Intradermal monitoring is an accurate and
cost-effective way of monitoring temperature during operation. Although it is
essential to achieve a rise in temperature of 1 degrees C, our most important
finding was that the final temperature in both hands and axillae should be above
35 degrees C and as near as possible to 36 degrees C.
PMID- 10688221
TI - Intestinal perfusion during pneumoperitoneum with carbon dioxide, nitrogen, and
nitric oxide during laparoscopic surgery.
AB - OBJECTIVE: To find out what effect insufflation pressure and type of gas have on
intestinal perfusion during pneumoperitoneum. DESIGN: Randomized, controlled,
prospective, experimental study. SETTING: University affiliated animal
experimental laboratory, Sweden. ANIMALS: Fasted, anaesthetised, domestic pigs of
both sexes operated on laparoscopically (n = 7, weight 26-31 kg). INTERVENTIONS:
Insufflation of carbon dioxide (CO2), nitric oxide (NO), or nitrogen (N2) at
intra-abdominal pressures of 0, 5, 10, 15 and 20 mm Hg. MAIN OUTCOME MEASURES:
Cardiac output, portal blood flow, and jejunal mucosal perfusion. RESULTS:
Cardiac output decreased during N2 and NO (15, 20 mm Hg) but not during CO2
insufflation because of an accompanying tachycardia. Portal flow decreased during
insufflation with N2 and NO (15, 20 mm Hg) and CO2 (20 mm Hg). Jejunal perfusion
was reduced during N2 and NO insufflation (5-20 mm Hg) but remained unchanged
during CO2 insufflation (5-20 mm Hg). CONCLUSIONS: Insufflation with CO2
maintained jejunal mucosal perfusion, probably as a result of hypercarbia as N2
at equal pressures reduced mesenteric flow. The vasodilator NO provided no
haemodynamic benefit.
PMID- 10688222
TI - Improvement of portal flow and hepatic microcirculatory tissue flow with N
acetylcysteine in dogs with obstructive jaundice produced by bile duct ligation.
AB - OBJECTIVE: To find out if N-acetylcysteine (NAC) would improve hepatic
circulation in dogs with obstructive jaundice. DESIGN: Open laboratory study.
SETTING: University hospitals, Japan and France. MATERIALS: 14 male beagle dogs
and 10 male Wistar rats. INTERVENTIONS: Obstructive jaundice was produced by
ligation of the common bile duct (CBD) for 7 days in both dogs and rats. Either
5% dextrose (control group, n = 7) or NAC (NAC group, n = 7) was given to dogs.
Sinusoidal endothelial cells were obtained from rats after ligation by
elutriation, and varying amounts of NAC were given. MAIN OUTCOME MEASURES: The
volumes of portal blood flow and hepatic microcirculatory tissue flow were
reduced after ligation of the CBD, but those increased after NAC had been given
to dogs with obstructive jaundice. NAC increased the concentrations of plasma
cyclic 3',5'-guanosine monophosphate (cGMP). It also increased concentrations of
serum and hepatic-reduced glutathione, and hepatic adenosine triphosphate (ATP)
in cholestatic dogs, and secretion of cGMP from sinusoidal endothelial cells from
rats with obstructive jaundice. CONCLUSION: These results suggest that NAC given
intravenously effectively improves hepatic circulation and hepatic function in
dogs with obstructive jaundice.
PMID- 10688223
TI - Direct insertion of a hepatic arterial catheter after hepatectomy.
PMID- 10688224
TI - Pancreatic foregut cyst.
PMID- 10688225
TI - 'Body packer' syndrome: characteristics and treatment--case report and review.
PMID- 10688226
TI - Solitary sternal breast cancer metastases treated by sternectomy and muscle flap
reconstruction.
PMID- 10688227
TI - Some plane truths about pictures: notes on Wagemans, Lamote, and van Gool (1997).
AB - Wagemans, Lamote, and van Gool (1997) have attempted to show that observers can
determine the geometric equivalence of shapes seen in perspective, or in
projective transformation. Artifacts of measurement in their procedures forestall
such a conclusion. Their experiment fails to control projective properties
adequately, and also confounds the transformations of shear and compression.
Their evidence that observers can discern the equivalence of shapes under
perspective can be reconstrued as evidence for sensitivity to different,
unrelated properties: to the plane compression that follows from the depiction of
flat shapes in perspective, and to gross differences in shape not specific to
projective geometry. An improved set of procedures is proposed for the
measurement of stimuli in the study of visual shape constancy.
PMID- 10688228
TI - Pre-attentive segmentation in the primary visual cortex.
AB - The activities of neurons in primary visual cortex have been shown to be
significantly influenced by stimuli outside their classical receptive fields. We
propose that these contextual influences serve pre-attentive visual segmentation
by causing relatively higher neural responses to important or conspicuous image
locations, making them more salient for perceptual pop-out. These locations
include boundaries between regions, smooth contours, and pop-out targets against
backgrounds. The mark of these locations is the breakdown of spatial homogeneity
in the input. for instance, at the border between two texture regions of equal
mean luminance. This breakdown causes changes in contextual influences, often
resulting in higher responses at the border than at surrounding locations. This
proposal is implemented in a biologically based model of VI in which contextual
influences are mediated by intra-cortical horizontal connections. The behavior of
the model is demonstrated using examples of texture segmentation, figure-ground
segregation, target-distractor asymmetry, and contour enhancement, and is
compared with psychophysical and physiological data. The model predicts (1) how
neural responses should be tuned to the orientation of nearby texture borders,
(2) a set of qualitative constraints on the structure of the intracortical
connections, and (3) stimulus-dependent biases in estimating the locations of the
region borders by pre-attentive vision.
PMID- 10688229
TI - The roles of polarity and symmetry in the perceptual grouping of contour
fragments.
AB - We describe two experiments that investigate the roles of polarity and symmetry
in the perceptual grouping of contour fragments. Observers viewed, for one second
on each presentation, arrays of oriented, spatial-frequency band-pass, elements,
in which a subset of the elements was aligned along a twisting curve. In each of
five conditions we measured observers' ability to detect aligned combinations of
even- and odd-symmetric elements, of the same and different polarities, against a
background of 'noise' elements. As with previous experiments we found that the
'path' could be reliably detected, even when the elements of the path were
oriented at angles of up to +/- 60 deg relative to each other. Detection of the
path was still possible when the polarity of path elements alternated. However,
the probability of detection of the path was raised significantly when the path
elements were all of the same polarity. Perceptual grouping of even-symmetric
elements was no different to perceptual grouping of odd-symmetric elements. The
results provide evidence, that in achieving integration of contour fragments, the
visual system uses a process that is to some degree phase selective. We use the
results to describe how the visual system may resolve natural contours when they
occur against backgrounds that vary over a wide range of intensities. The data
presented here have been published in conference-abstract form (Hayes et al.,
1993; Field et al., 1997).
PMID- 10688230
TI - Perceived motion in complementary afterimages: verification of a neural network
theory.
AB - Steady fixation of a regular pattern like a bar grating or concentric circles
leads to a complementary afterimage at pattern offset. The afterimage has the
appearance of shimmering lines that are locally orthogonal to the orientations of
the inducing image. Additionally, the afterimage includes motion running parallel
to the orientation of the afterimage lines. We argue that this afterimage motion
supports the existence of a cue to motion that is based on the spatial
organization of oriented responses. This cue was previously proposed after
analysis of a neural network model of visual perception. We test predictions of
the model on various types of complementary afterimage inducing stimuli. When a
contrast or size gradient is included in the inducing image, the afterimage
motion moves toward the higher part of the gradient, in agreement with the model.
Implications of this cue for computational and neurophysiological theories of
motion perception are discussed.
PMID- 10688231
TI - Conjunctions of colour, luminance and orientation: the role of colour and
luminance contrast on saliency and proximity grouping in texture segregation.
AB - To examine whether perceptual grouping on the basis of orientation can be
performed simultaneously with or only subsequently to grouping according to
colour or luminance, we tested whether subjects are able to segregate arrays of
texture elements that differ from surrounding elements by conjunctions of either
(i) colour and orientation, or (ii) luminance contrast and orientation, or (iii)
luminance contrast polarity and orientation. Subjects were able to use
conjunctions between luminance and orientation for segregation but not
conjunctions between colour or contrast polarity and orientation. Our results
suggest that (i) in agreement with earlier findings, there seem to exist no
specific conjunction detectors for colour and orientation or contrast polarity
and orientation, and (ii) when orientation defined textures are to be
distinguished by virtue of differences in luminance, colour, or contrast
polarity, luminance provides a much stronger cue than colour or contrast polarity
for saliency-based orientation grouping.
PMID- 10688232
TI - Tilt aftereffects generated by bilaterally symmetrical patterns.
AB - Tilt aftereffects were generated by bilaterally symmetrical dot patterns. Both
expansion and contraction effects, similar in size and magnitude to effects
usually reported with luminance contours, were observed after adaptation to
symmetrical patterns tilted 15 deg or 75 deg respectively from a vertically
oriented test. Large effects were found when both adapting and test stimuli were
symmetrical patterns while smaller effects were found when the adapting stimulus
was symmetrical and test stimulus was a grating. A third experiment, which
manipulated the number of dots near the axis line, confirmed the above findings;
expansion and contraction effects were observed again. The results of these
experiments suggest that the neural mechanism underlying the perception of
luminance contours may be linked to the mechanism for the detection of symmetry.
PMID- 10688233
TI - Risk-stratification strategy eludes error researchers.
PMID- 10688234
TI - Studies published on clopidogrel-aspirin for coronary stent placement.
PMID- 10688235
TI - Higher copayment does not hurt compliance, study suggests.
PMID- 10688236
TI - HMOs pressed by rising drug costs, industry report shows.
PMID- 10688237
TI - Partnering with nurses to manage heparin therapy with a weight-based protocol.
PMID- 10688238
TI - SAMe: S-Adenosylmethionine.
PMID- 10688239
TI - New drug overview. Pioglitazone hydrochloride.
PMID- 10688240
TI - Making a difference in hypertension.
PMID- 10688241
TI - Projecting future drug expenditures--2000.
AB - Drug cost projections for 2000 and factors that are likely to influence drug
costs are discussed. The total increase in drug costs in 2000, assuming there are
no major unforeseen events (e.g., Medicare coverage of outpatient prescriptions
or important new drugs) can be anticipated to be 12-15% above that in 1999.
Prescription drug expenditures are projected to increase an average of 11.2%
annually between 1999 and 2001. Although there were fewer new drug approvals in
the first half of 1999 than in 1998, we can expect that many new, important, and
probably expensive agents will be coming to market in 2000. Analysts calculate
that pharmaceutical companies invested approximately $24 billion in research and
development in 1999, and there are predictions that mergers within the
pharmaceutical industry will reduce the number of major pharmaceutical firms to
13. The introduction of pharmacogenomics is of great interest because of its
potential to significantly affect drug therapy and the discovery of new agents.
Sales of generic drugs are anticipated to increase from $12 billion in 1999 to
$14 billion in 2000. Competition between the brand-name and generic drug
industries is intensifying, but it remains unclear whether generic drug pricing
will offset brand-name price increases. Internet pharmacy has become a reality
and is under federal and state scrutiny. The pharmaceutical and drug distribution
industries are changing dramatically, and there is concern that many new
prescription drugs will not be readily available to patients because of their
high cost. Should this occur, action by the federal government is a possibility.
PMID- 10688242
TI - Compliance with and dosing of angiotensin-converting-enzyme inhibitors before and
after hospitalization.
AB - Compliance with and dosing of angiotensin-converting-enzyme (ACE) inhibitors as
they occur before and after hospitalization for heart failure were studied, and
factors predictive of compliance with and dosing of ACE inhibitors after
hospitalization were identified. Two hundred thirty-six patients hospitalized
with heart failure between October 1, 1995, and April 30, 1996, were identified.
Compliance with and use and dosing of ACE inhibitors were examined over the 180
day period before admission and the 180-day period after discharge using an
integrated pharmacy and medical claims database. Use of an ACE inhibitor was
defined as at least one claim for an ACE inhibitor over the period examined, and
dosing was assessed by calculating the mean percentage of an adequate daily dose
dispensed. Before hospitalization 109 patients (46.2%) used ACE inhibitors, and
after hospitalization 148 (62.7%) used them--a significant increase. ACE
inhibitor use before hospitalization was a predictor of postdischarge use.
Younger patients were more likely to take ACE inhibitors after hospitalization
than older ones, and men had better compliance after hospitalization than women.
Additional analyses revealed that, among hospitalized patients, compliance was
lower in individuals who also took an antidepressant. Dosing increased from 72%
to 85% of an adequate daily dose after hospitalization among patients who took
ACE inhibitors during both prehospitalization and posthospitalization periods.
However, almost one third of hospitalized patients stopped taking their ACE
inhibitor within six months of hospital discharge. The study found few
significant predictors of patient compliance after hospitalization. Dosing of ACE
inhibitors before and after hospitalization needs to be improved.
PMID- 10688243
TI - Applied pharmacoeconomics: modeling data from internal and external sources.
AB - The use and application of techniques for modeling data obtained from various
data sources are discussed. Modeling with internal and external data has become a
popular way for health care organizations to apply pharmacoeconomics to pharmacy
practice. Modeling studies use existing clinical and epidemiologic data to
project the effect of a clinical, policy, or medication decision on a patient,
population, or organization. Although several modeling techniques have been used
in health care, the most common approaches are to modify and adapt existing
models or to develop a unique model to answer questions of interest in a specific
practice setting. Typically, an economic model developed by adapting an existing
one will use either the clinical decision-analysis or Markov modeling technique.
Regardless of the technique used, external data must be carefully evaluated to
ensure that the data are appropriate for use in making decisions at a specific
organization. For example, cost data must be analyzed to ensure that the
calculations are reproducible. Also, it must be acknowledged that this strategy
may not always be appropriate. The use of modeling techniques can assist decision
makers in making more informed clinical, policy, and medication decisions in real
world settings. Caution is required when adapting and interpreting existing
models to ensure appropriate application in a specific organization.
PMID- 10688244
TI - Clinical practice guidelines and the standard of care.
PMID- 10688245
TI - ASHP therapeutic position statement of optimizing treatment of hypertension.
AB - The JNC-VI report provides solid recommendations for optimizing the treatment of
hypertension. Suggestions for when to initiate lifestyle modifications and drug
therapy on the basis of risk stratification are major improvements in the current
report. Although diuretics and beta-blockers are still considered the preferred
agents for all patients with uncomplicated hypertension, individualization of
therapy when there are complications or coexisting conditions is strongly
encouraged. If blood pressure control rates are to improve in the United States,
aggressive approaches to the prevention, identification, management, and tracking
of patients and populations with hypertension will be required. Pharmacists will
be critical in these efforts to improve blood pressure control and will often
need to collaborate with physicians in providing drug therapy management. All
pharmacists who help manage patients with hypertension should be familiar with
the entire JNC-VI report.
PMID- 10688246
TI - Joint commission hospice survey for pharmaceutical services.
PMID- 10688247
TI - Predictable positive bias with portable capillary blood monitors.
PMID- 10688248
TI - Protection of labile pharmaceuticals.
PMID- 10688249
TI - Evidence-based medicine: its application to laboratory medicine.
AB - The current health care environment of cost-cutting highlights the need to
reinforce the contribution of laboratory medicine to improvement in health care.
This must be a patient-focused activity using continuous quality improvement, a
familiar concept in laboratory practice. Involvement in the creation of clinical
practice guidelines, care maps, and outcome measures will place laboratory
medicine in the circle of continuous quality improvement. The laboratory must
provide strong evidence that tests contribute to better overall resource
utilization. Laboratory Information Systems can be used to better integrate
laboratory data with clinical, diagnostic, pharmaceutic, statistical, and
financial information. Improving laboratory utilization requires clear
demonstrations of appropriate versus inappropriate laboratory use, and
instructions on implementing appropriate use. The education of laboratory
professionals should include search strategies, understanding the diagnostic
accuracy of medical tests, and the application of systematic reviews and meta
analysis. With the rapid increase in the data base supporting evidence-based
laboratory medicine, there is a significant challenge in translating the existing
knowledge into practice. There is also a need for a cooperative strategy between
the diagnostics industry and the laboratory medicine profession to provide
evidence of the added value of laboratory testing. There is a significant role in
developing the academic basis of the unique aspects of evidence-based laboratory
medicine.
PMID- 10688250
TI - Identification of uridine diphosphate glucuronosyltransferases involved in the
metabolism and clearance of mycophenolic acid.
AB - Mycophenolic acid, the active metabolite of the immunosuppressant and
antiproliferative agent, mycophenolate mofetil, is primarily metabolized by
glucuronidation to the inactive 7-O-glucuronide. Although the uridine diphosphate
(UDP) 7-O-glucuronide is the principal excretion product of this drug, carboxyl
linked glucuronides have also been detected in vitro and in vivo. To identify
human UDP glucuronosyltransferases that are active in the glucuronidation of
mycophenolic acid, cDNAs encoding individual UDP glucuronosyltransferase forms
have been expressed in cell culture, and the capacity of the expressed enzymes to
use mycophenolic acid as a substrate has been assessed. Two UDP
glucuronosyltransferase forms, UGT1A8 and UGT1A10, were active in the
glucuronidation of mycophenolic acid. Both enzymes are predominantly expressed in
the gastrointestinal tract and hence, may play a role in the metabolism of
mycophenolic acid in the gastrointestinal tract and in the acquisition of
resistance to the mito-inhibitory effects of this drug in cultured human
colorectal carcinoma cell lines. The identities of the UDP
glucuronosyltransferase forms that are mainly responsible for the glucuronidation
of mycophenolic acid in the liver and kidney remain unknown; however, UGT1A9 may
be important in this respect as the cDNA-expressed enzyme has some capacity to
glucuronidate mycophenolic acid. Other UGT1A forms in the liver and kidney
(UGT1A1, UGT1A3, UGT1A4, and UGT1A6) were inactive toward mycophenolic acid.
PMID- 10688251
TI - Pharmacokinetics and concentration-control investigations of mycophenolic acid in
adults after transplantation.
AB - Data have emerged that provide the scientific basis for therapeutic drug
monitoring of mycophenolic acid (MPA) in transplant patients receiving
mycophenolate mofetil (MMF), the parent drug, in combination with other
immunosuppressive agents. There is a significant relationship between the dose
interval MPA AUC and risk for acute rejection based on retrospective
investigations in renal and heart transplant patients and on prospective
investigations in renal transplant patients. The MPA dose-interval AUC varies
naturally by more than 10-fold in renal and heart transplant patients. Other
significant sources of pharmacokinetic variability for MPA include the effects of
concomitant medications, and the effects of disease states such as renal
dysfunction and liver disease on the steady state MPA AUC. Individualized MMF
dose evaluation, guided by MPA plasma concentrations, is becoming the standard of
practice at a growing number of transplant centers worldwide because of these
factors and because of the need to closely evaluate the immunosuppression
afforded by MPA when a change in the immunosuppression regimen in stable
transplant patients is planned. Investigations of therapeutic drug monitoring
strategies with an emphasis on identifying an optimal abbreviated sampling
strategy for MPA AUC estimation are ongoing. Based on the concentration-outcome
studies and experience at the authors' institutions and other centers, the
authors propose a set of therapeutic drug monitoring guidelines for MPA in stable
renal and heart transplant patients for the immediate (first 3 months
posttransplant) and maintenance (>3 months) periods. When MPA binding to human
serum albumin is altered, as occurs in patients with significant renal
dysfunction, liver disease, or a substantial reduction in human serum albumin
concentration, the possibility of increased MPA free fraction and free
concentration will need to be taken into account in the interpretation of MPA
total concentrations.
PMID- 10688252
TI - Pharmacokinetic and metabolic investigations of mycophenolic acid in pediatric
patients after renal transplantation: implications for therapeutic drug
monitoring. German Study Group on Mycophenolate Mofetil Therapy in Pediatric
Renal Transplant Recipients.
AB - The need for mycophenolic acid (MPA) monitoring is still under discussion. Key
issues for the PK/PD relationships of this drug are: the role of metabolites, the
usefulness of AUC versus predose levels, and the need to monitor the free
concentration of MPA (f-MPA). Recent advances have revealed that, in addition to
7-O-MPAG, three additional MPA metabolites are present in the plasma of
transplant recipients. One of these metabolites (M-2), identified as an acyl
glucuronide of MPA, was found to inhibit IMPDH-II in vitro. This active
metabolite was also found to cross-react in the Emit assay for MPA. In an ongoing
multicenter study, the authors are evaluating the relevance of monitoring total
(t-MPA) and free mycophenolic acid (f-MPA) in pediatric renal transplant
recipients. As in adults, a time-dependent increase of t-MPA-AUC(0-12h) within
the first 3 months posttransplant (35 versus 64 mg x h/L, [corrected] 3 weeks
versus 3 months respectively; daily dosage: 0.6 g/m2 bid) was seen. Receiver
operating characteristics curve analyses were used to test the ability of predose
levels or AUC(0-12h) to discriminate between cases with no complications and
those with acute rejection, adverse events (severe infections, leukopenia), or
gastrointestinal disorders observed during the early posttransplant course. In
agreement with observations in adults, a significant (p = 0.001) association was
observed between AUC(0-12h) and acute rejection. A t-MPA-AUC(0-12h) of
approximately 30-60 mg x h/L [corrected], as determined by HPLC, seems to be a
reasonable target for the early posttransplant period. It remains to be
elucidated whether regular predose level monitoring may be of more practical
value. A higher incidence of rejection was observed at predose MPA concentrations
< or = 1 mg/L, as measured by HPLC. In contrast to t-MPA, f-MPA-AUC(0-12h) was
significantly related to severe infections and leukopenia. The risk for severe
adverse events was increased at f-MPA- AUC(0-12h) values > or =600 microg x h/L
[corrected]. On the basis of these data and the observed variability in the
pharmacokinetics of MPA, the development of monitoring strategies for this drug
appears to be promising.
PMID- 10688253
TI - Pharmacokinetics of mycophenolic acid in renal insufficiency.
AB - Mycophenolate mofetil (MMF) is now widely used in solid organ transplantation.
MMF is rapidly converted to its active form, mycophenolic acid (MPA), upon
reaching the systemic circulation. MPA is metabolized to its glucuronide
metabolite, mycophenolic acid glucuronide (MPAG), by glucoronyl transferases in
the liver and possibly elsewhere. MPAG is then excreted by the kidney. MPA is
extensively and avidly bound to serum albumin. Previous studies have demonstrated
that it is only the free (non-protein-bound) fraction of MPA that is available to
exert its action. In vivo and in vitro studies demonstrate that renal
insufficiency decreases the protein binding of MPA and increases free MPA
concentrations. This decrease in protein binding seems to be caused both by the
uremic state itself and by competition with the retained metabolite MPAG. The
disposition of MPA in patients with severe renal impairment may be significantly
affected by this change in protein binding.
PMID- 10688254
TI - Pharmacokinetics and metabolism of sirolimus.
AB - Sirolimus (rapamycin, Rapamune) is a potent immunosuppressive drug that received
marketing approval from the US Food and Drug Administration on September 15,
1999. Research into defining its pharmacokinetic (PK) behavior, interaction with
other agents, and metabolism is ongoing. It has been established that oral doses
of both liquid and solid formulation are rapidly, though incompletely and
variably, absorbed. Metabolism by the intestinal and hepatic CYP3A family of
enzymes likely contributes to variability in absorption and low bioavailability.
Sirolimus has a long terminal half-life, the AUC correlates well with trough and
peak concentrations, and it exhibits a moderate degree of dose proportionality.
There is significant interpatient variability in PK parameters of sirolimus,
though it exhibits predictable PK behavior when used with prednisone and
cyclosporine neoral. There is a decreased rejection risk with higher doses and
target level attainment. Several species of sirolimus metabolites have been
characterized, and are measurable in whole blood and tissue specimens. Many more
species of sirolimus metabolites are detectable, but they are not quantifiable at
this time. The total concentration of metabolites appears to be less than that of
the parent drug when examined through the PK profile. A reference method for the
quantitation of metabolites remains elusive because of a lack of proper
standardization. The clinical significance of sirolimus metabolites remains to be
proven.
PMID- 10688255
TI - Pharmacoeconomics of therapeutic drug monitoring in transplantation.
AB - Immunosuppressive drugs have contributed significantly to the success of organ
transplantation. Therapeutic drug monitoring is an integral part of transplant
protocols. However, there is little information concerning its positive
contribution to pharmacoeconomics. Before developing studies to demonstrate the
potential benefits of TDM, consideration must be given to the type of TDM to be
evaluated. It is argued that, given that the lymphocyte in the central
compartment is the target for immunosuppressants, Area-Under-the-Curve monitoring
may be a better reflection of control and toxicity than traditional trough
monitoring.
PMID- 10688256
TI - Cytokines and their receptors: an overview.
AB - Cytokines participate in the induction and effector phases of all immune and
inflammatory responses. They are therefore obvious candidates for exploitation as
drugs or drug targets to promote, limit, or alter these responses in infection,
allergy, autoimmunity, and other disease states. Although some cytokines and
related molecules are already in clinical use, the full therapeutic potential of
this class of hormones has yet to be realized, and this will depend in part on
understanding their normal functions and regulation in health and disease. An
overview is given of the cytokines and their receptors, their genetic and
structural relationships, and the regulation of their activities by naturally
occurring antagonists and other physiologic mechanisms. Some of the ways in which
new therapeutic strategies are being developed from knowledge of the structure,
function, and regulation of these various components of the cytokine network are
outlined.
PMID- 10688257
TI - Immunophilins: their properties and their potential role in therapeutic drug
monitoring.
AB - This article reviews recent developments in the immunophilin arena and the
current state of knowledge about the biochemical properties of immunophilins. The
role of immunophilin-binding assays is also explored with the conclusion that
some of these immunosuppressive-drug-binding proteins may provide better assays
for sirolimus and tacrolimus than current immunoassays.
PMID- 10688258
TI - The FTY720 story.
AB - The chemical 2-amino-2[2-(4-octylphenyl)ethyl]-1,3,propane diol is one of a class
of small-molecule immunosuppressive agents. Better known as FTY720, this compound
was chemically synthesized in an effort to minimize the toxic in vivo properties
of a structurally related and highly potent immunosuppressive agent, myriocin.
FTY720's mechanism of action, although not fully characterized, appears to be
unique among immunosuppressants. Whereas the most well known biochemical
characteristic of myriocin is its ability to inhibit serine palmitoyl
transferase, the enzyme that initiates the biosynthetic pathway that leads to
sphingosine, FTY720 is ineffective in this regard. In vivo, FTY720 induces a
significant reduction in the number of circulating lymphocytes. It is thought to
act by altering lymphocyte trafficking/homing patterns through modulation of cell
surface adhesion receptors and ligands in a manner that has yet to be elucidated.
Although much research has yet to be done to unravel the nature of the mechanism
of action of FTY720, its efficacy has been sufficiently proven in numerous animal
models, especially when administered in combination with cyclosporine. The agent
is now progressing through human clinical trials, with the results of phase 1
clinical trials showing safety and tolerability in adult recipients of renal
transplants. It is hoped that FTY720 will eventually prove to be an efficacious
new weapon in the immunosuppressive armamentarium.
PMID- 10688259
TI - Challenges of toxicology for the millennium.
AB - In meeting the challenges of toxicology, clinical and forensic toxicologists
should expand their services and engage in research and development to meet
changing needs. Expanding roles could potentially derive from the threat of
terrorism, genotyping for interpretation of potential toxic drug interactions,
and criminalistic testings. At the threshold of the next millennium, terrorism
via weapons of mass destruction (WMD) has migrated from the war zones to civilian
settings. These WMD may be in the form of nuclear, biological, and chemical
devices (NBC). Recently, the possible use of chemical/biological weapons in the
Middle East conflicts, the use of sarin in a Tokyo subway station, and the
unregulated availability of nuclear fuel in some countries all have heightened
the potential for international and domestic NBC. In preparation for NBC, both
government and civilians in major American cities have been trained for safe
handling of patients and casualties. Forensic and clinical toxicologists should
be knowledgeable about the clinical pharmacology, safe samples processing, and
possible screening and/or analysis of samples exposed to or containing:
vesicants; cyanide; and nerve, riot control, and pulmonary agents. These samples
may be transported for further analysis and confirmed by designated central
laboratories. In criminal/correctional settings, toxicologists should engage in
quality assurance and consultation with attorneys, judges, and correctional
professionals. With the emergence of pharmacogenetics, genotyping may enhance
rational drug therapy for enhanced patient care, and may explain adverse or fatal
drug reactions in postmortem analysis.
PMID- 10688260
TI - Aquatic toxicology.
AB - Australia is blessed with a great diversity of unique species in its fresh waters
and in the marine environment around its coast. There is evidence that human and
natural events are impacting on these species. Such impacts are associated with
various agricultural, industrial, and domestic practices and with natural and
anthropogenically driven climate change. Among the species most affected are
those living in aquatic and marine environments. Some of these, such as
cyanobacteria and dinoflagellates, have the potential for toxicity. Linked to
this, there is the potential benefit of harnessing the pharmacologic potential of
these toxins.
PMID- 10688261
TI - Ion channel toxins and therapeutics: from cone snail venoms to ciguatera.
AB - Ion channels are intimately linked to all neurotransmission and neurotransmitter
release processes, but in disease states often contribute adversely to disease
pathology. The diversity and distribution of ion channel types and subtypes being
uncovered through the use of molecular biology and toxin probes present an
exciting opportunity for the discovery of new, more selective drugs. Among ion
channels targeted by cone shell venom peptides (conotoxins) are the voltage
sensitive sodium, calcium, and potassium channels which open and then close
(inactivate) in response to membrane depolarization, and thus regulate
neurotransmission and the neurotransmitter release process. Conotoxins also
target ligand-gated ion channels, including the NMDA-glutamate channel and the
nicotinic acetylcholine receptor channel. The diversity of subtypes, especially
those subtypes upregulated in disease states, makes ion channels a rapidly
expanding therapeutic area. Conotoxins represent some of the most selective
inhibitors of ion channel subtypes and have often been used as the defining
ligand. In this overview, the structures and therapeutic potential of conotoxins
active at ion channels are highlighted. The activity and structures are then
contrasted with ciguatoxins, which are responsible for the food poisoning known
as ciguatera. A universal liquid chromatography/mass spectrometry approach to the
detection of these classes of toxins is briefly discussed.
PMID- 10688262
TI - Bites and stings from venomous animals: a global overview.
AB - Venomous and poisonous animals are a significant cause of global morbidity and
mortality. This Seminar will cover selected aspects of these animals, their
venoms/poisons, and their clinical impact on humankind, from a global
perspective, but with a distinctive Australian flavor and a clinical emphasis.
Venomous snakes are found throughout most of the world, including many oceans,
and have evolved a variety of highly effective toxins and methods of delivery.
Their impact on humans is considerable, most current data suggesting they cause
in excess of 3 million bites per year with more than 150,000 deaths. Particularly
in the rural tropics, snakebite morbidity and mortality has a significant human
medical and economic toll. The major groups of snakes causing bites are the
vipers, the elapids (cobra type), the sea snakes, the side-fanged vipers, and the
back-fanged colubrids. Australian venomous snakes are nearly all elapids and have
evolved some of the most toxic of all snake venoms. Their effects include potent
procoagulants and anticoagulants, neurotoxins, myotoxins, and nephrotoxins, but a
distinct absence of the major local necrotoxins found in some non-Australian
elapids and many vipers. The effect of these toxins on humans is not limited to
envenoming, for the toxins are proving invaluable as research tools and
diagnostic agents, and may even have a future as precursors of therapeutic
agents. Because of the high toxicity and diversity of Australian elapids, a
variety of monovalent antivenoms have been developed. There is also a venom
detection kit to determine the type of snake and allow targeted antivenom
therapy. The kit has also increased information available on diagnostic patterns
of envenoming for each species. Australia is also home to the world's most lethal
spiders, the funnel webs of eastern Australia, as well as the red back spider,
the single most common reason for antivenom treatment in Australia. The latter
spiders have been accidently exported to Japan. Within the marine environment
exist a vast array of toxic animals, both poisonous and venomous, which not only
cause morbidity and mortality in humans, but offer an incredibly rich array of
valuable toxins. Australian waters contain some of the most lethal and medically
problematic species, presenting a diverse range of clinical problems.
PMID- 10688263
TI - Toxicology and evaluation of microcystins.
AB - This paper reviews the toxicity and tumor-promoting properties of microcystins.
Methods for screening and/or identification of microcystins in environmental
samples are discussed and compared. Specific emphasis is placed on newly
developed extraction/detection methods, e.g., solid phase microextraction (SPME)
technique, and capillary electrophoresis coupled with laser-induced fluorescence
detection. The results of a kinetic analysis of the effects of microcystins on
phosphorylase-a binding to phosphatase-2A using a surface plasmon resonance
biosensor are also presented.
PMID- 10688264
TI - Clinical toxicology: a tropical Australian perspective.
AB - Tropical Australia has an amazing diversity of venomous fauna, from "the world's
most venomous creature," the multi-tentacled (chirodropid) box jellyfish Chironex
fleckeri, to aggressive spiders whose venom remains to be characterized. All
genera of highly venomous Australasian elapid snakes are present, except for
tiger snakes. Most notable is the taipan (Oxyuranus scutellatus), with the most
efficient "snap-release" biting mechanism of any snake and venom components
causing the full constellation of clinical envenoming features: coagulopathy from
fibrinogen depletion (procoagulant), neurotoxicity (predominantly presynaptic
neurotoxin) and rhabdomyolysis (myotoxin). Brown snakes (Pseudonaja textilis and
P. nuchalis) now account for most snake bite fatalities in Australia, as a result
of severe coagulopathy and a poorly defined early scenario of collapse,
postulated to be caused by profound hypotension caused by transient myocardial
dysfunction associated with prothrombin activation. Other venomous entities
include paralyzing ticks, the blue-ringed octopus, stone fish and other marine
animals with venomous spines, paralyzing cone shells, and a wide range of
jellyfish including Carukia barnesi and possibly other four-tentacled (carybdeid)
box jellyfish causing the Irukandji syndrome.
PMID- 10688265
TI - Post-mortem drug analyses in bone and bone marrow.
PMID- 10688266
TI - Capillary electrophoresis: a new analytical tool for forensic toxicologists.
AB - In capillary electrophoresis, electrophoretic or electrokinetic separations are
carried out in tiny capillaries at high voltages (10-30 kV), thus achieving high
efficiency (N > 105), resolution power, and mass sensitivity (down to 10(-18)-10(
20) moles). The main characteristics of capillary electrophoresis are versatility
of application (from inorganic ions to large DNA fragments), use of different
separation modes with different selectivity, low demands on sample volume,
negligible running costs, possibility of interfacing with different detection
systems including mass spectrometry, and the ruggedness and simplicity of the
instrumentation. Capillary electrophoresis applications in the forensic sciences
are now rapidly growing, particularly in forensic toxicology. The present paper
briefly describes the basic principles of capillary electrophoresis and presents
a selected review of its main applications to the analysis of illicit/controlled
drugs in biologic samples. An original analytical approach to the determination
of carbohydrate deficient transferrin, a new marker of chronic alcohol abuse,
based on capillary electrophoresis is also described. It is concluded that the
peculiar separation mechanisms and the high complementarity of capillary
electrophoresis to chromatography make it a new powerful tool of investigation in
the hands of forensic toxicologists.
PMID- 10688267
TI - Cylindrospermopsin, a cyanobacterial alkaloid: evaluation of its toxicologic
activity.
AB - This paper describes the natural occurrence of the toxin, cylindrospermopsin, in
two species of cyanobacteria found in Australia. The structure and chemical
properties of this compound are described along with a nontoxic analog of
cylindrospermopsin. The results of both intraperitoneal (IP) and oral dosing of
mice show that hepatotoxicity is the main effect of cylindrospermopsin in vivo,
but that a thrombohemorrhagic phenomenon is observed in a proportion of dosed
animals. It has been shown that the toxin can be metabolized in vivo and that a
bound metabolite occurs in the liver. Cytotoxicity experiments using cell
cultures show that cylindrospermopsin is more cytotoxic to isolated rat liver
hepatocytes than to other cell types. Risk assessment calculations show that
guideline values for cylindrospernopsin in drinking water should lie in the low
microgram per liter range.
PMID- 10688268
TI - Setting standards of practice in therapeutic drug monitoring and clinical
toxicology: a North American view.
AB - Standards for therapeutic drug monitoring (TDM) must address the factors required
for a valid TDM result. These are that the test be ordered with an appropriate
indication, samples be obtained at the appropriate time, analysis be precise and
accurate, and the result be interpreted and used correctly. General indications
for ordering drug concentrations are to assess patient compliance, lack of
response, adverse effects, initial or new baseline concentration after steady
state has been achieved, and drug interactions. In establishing standards for
clinical toxicology testing, the following points need to be considered:
relatively few drugs will be involved in the majority of overdoses in a given
location, the majority of drug overdoses and poisonings are treated
symptomatically and supportively, and there are a relatively small number of
drugs the testing of which may provide useful information in the emergency
setting. An effective toxicology screen can be designed by first developing a
list of candidate drugs that have antidotes, require specific treatment, are
frequently encountered, or have a delayed onset of toxicity. Once such a list is
in hand, it can be further evaluated to determine whether qualitative or
quantitative testing is most appropriate and if rapid, convenient methods of
analysis are available.
PMID- 10688269
TI - Athletic drug testing: an analyst's view of science and the law.
AB - Detection of performance-enhancing drugs in sports has received increasing
visibility. Athletic drug testing uses sophisticated technology and both
interindividual (population) and intraindividual reference ranges to interpret
data. An effective program must incorporate educational and adjudication
components in addition to testing. The difficult interface between science and
the law is evident in many recent sports arbitration decisions.
PMID- 10688270
TI - Drugs in sports: analytical trends.
AB - A minority of athletes continues to use prohibited drugs in sports to enhance
performance. Athletes discovered using these drugs can be subject to severe
penalties, often resulting in media and public scrutiny, especially at major
events such as the Olympic Games. The International Olympic Committee (IOC) has
set out the classes of the substances it bans in the IOC Medical Code. In many
cases "old" drugs such as anabolic steroids are still used, and current testing
regimes can test for these. Advances in the therapeutic treatment of illness have
resulted in new drugs or practices, many of which are difficult to detect and
which have been turned to the sinister role of performance enhancement. Detection
of some newly developed drugs which have been placed on the banned list offers a
major challenge to laboratories involved in sports dope testing. In some cases
this requires research into new applications of research techniques. These
techniques involve the novel use of gas chromatography/ mass spectrometry (GC/MS)
techniques, high-resolution mass spectrometry (HRMS), carbon isotope ratio mass
spectrometry, and immunoassay techniques.
PMID- 10688271
TI - Advances in understanding drug metabolism and its contribution to variability in
patient response.
AB - Recent advances in the understanding of the molecular biology and genetic
variability of human drug metabolizing enzymes, particularly cytochromes P450,
have contributed immensely towards clarifying the pharmacokinetics and
pharmacodynamics of many existing drugs, and are increasingly important in the
development of new chemical entities. However, whereas this knowledge has
implications for therapeutics, appreciation and application in clinical practice
have either been limited or yet to be realized. For example, the debrisoquine
polymorphism was discovered 20 years ago, but controlled prospective studies to
evaluate its clinical significance and pharmacoeconomic impact are few. Come the
millennium it will be seen to what extent traditional therapeutic drug
monitoring, involving the measurement of specific plasma drug concentrations, may
be complemented or replaced by more general phenotyping or genotyping screens for
human drug metabolizing enzymes.
PMID- 10688272
TI - Pharmacogenetic methods as a complement to therapeutic monitoring of
antidepressants and neuroleptics.
AB - A short review of the metabolism of psychoactive drugs and the pharmacogenetic
factors regulating the enzymes involved is presented here. The potential clinical
usefulness of phenotyping and genotyping individuals, with regard to their drug
metabolic capacity, is discussed. Indications for genotyping CYP2D6 and a flow
scheme for the combined use of conventional therapeutic drug monitoring (TDM) and
pharmacogenetic methods for optimizing dosage-schedules of psychoactive drugs are
suggested.
PMID- 10688273
TI - Pharmacogenetics of classical and new antipsychotic drugs.
AB - Several classical antipsychotic drugs, i.e., chlorpromazine, haloperidol,
perphenazine, thioridazine and zuclopenthixol; and some new neuroleptic drugs,
i.e., risperidone and sertindole, are metabolized predominantly by cytochrome
P450 (CYP) 2D6. Significant relationships have been reported between the steady
state plasma concentrations (Css) of some classical neuroleptics and the CYP2D6
activity or genotype. Several of these drugs also potently inhibit the CYP2D6
activity. These facts explain several drug metabolic interactions of the
classical drugs. Two studies failed to show that the CYP2D6 activity predicts the
therapeutic effects of haloperidol or perphenazine. Some studies have suggested
that the poor metabolizer phenotype is associated with the development of
oversedation during treatment with the classical drugs, but other studies have
been inconsistent or negative. The CYP2D6 phenotyping and genotyping appear to be
useful in predicting the Css of some classical drugs, but their usefulness in
predicting clinical effects must be further explored.
PMID- 10688274
TI - Therapeutic drug monitoring of antiretrovirals in human immunodeficiency virus
infection.
AB - The era of antiviral therapy directed against HIV-1 has now entered its second
decade. In the twelve years since the FDA approved the first antiretroviral drug
zidovudine there have been a number of seminal developments that have
revolutionized the approach to therapy. These advances converged to change the
treatment paradigm from one of therapeutic nihilism to that of cautious optimism.
First, several trials demonstrated that combination therapy of nucleoside reverse
transcriptase inhibitors (NRTIs) is superior to monotherapy in extending survival
and delaying disease progression. Second, the concept of virologic latency in
asymptomatic HIV-infected patients was revised. Mathematic modelling demonstrated
that there is an ongoing high level of virus production driving a rapid turnover
of CD4 cells at all stages of infection. Hence it was concluded that the aim of
antiretroviral therapy (ART) should be to "hit early and hit hard." Third,
significant advances in molecular virology facilitated the development of
quantitative methods to measure the circulating HIV plasma RNA. HIV viral load
has been shown to be a sensitive predictor of disease progression and a valuable
marker of response to therapy. However, none of these developments would have
translated into improved patient care without the advent of two new classes of
drugs-the protease inhibitors (PIs) and the nonnucleoside reverse transcriptase
inhibitors (NNRTIs).
PMID- 10688275
TI - Antiepileptic drug pharmacogenetics.
AB - Until recently, the drug treatment of epilepsy has been empirical. However, in
recent years as a result of improved understanding of seizure neurochemistry and
mechanisms of action of antiepileptic drugs (AEDs), drug treatment has become
somewhat more rational. Nevertheless, it is currently impossible to predict which
patient will respond to a particular AED, and which patient will experience
adverse drug effects. The only practical way to determine whether a patient will
find a drug useful is to try it. The discovery of genetic polymorphism in drug
metabolism has contributed significantly to understanding of the variability in
dose-concentration relationships, susceptibility to adverse effects, and
susceptibility to seizure intractability. The discovery that predisposition to
seizure intractability and expression of brain neuromolecules consequent to
seizures is under genetic control may allow a more rational approach to AED
choice. In the future, treatment may be guided by a series of pharmacogenetic
tests, which would serve not only to choose the most appropriate AED (in terms of
efficacy and adverse effects) but also to monitor the antiepileptogenic and the
evolution status of the disease.
PMID- 10688276
TI - Influence of dietary components on the gastrointestinal metabolism and transport
of drugs.
AB - There is widespread recognition that the ingestion of a meal is associated with a
number of physiologic changes (gastric pH, gastric emptying, hepatic blood flow,
etc.) that can significantly alter the rate and extent of drug absorption. It is
also well recognized that the components of food can alter drug absorption
through alterations in drug solubility. The nutritional status of a patient can
also contribute to variability in the pharmacokinetics of certain drugs. The more
recent finding that grapefruit juice can increase the bioavailability of certain
drugs, by reducing presystemic intestinal metabolism, has led to renewed interest
in the area of 'food-drug interactions.' Particular interest has focused on the
effects of the grapefruit flavonoid, naringin, and the furanocoumarin, 6',7'
dihydroxybergamottin, on the activity of intestinal CYP3A4. The possibility that
grapefruit juice might affect drug absorption via an interaction with intestinal
P-glycoprotein (P-gp) is also being explored. The growing use of herbal extracts
and phytopharmaceuticals raises a new challenge-will the use of these products
cause changes in the pharmacokinetics of 'conventional' drugs? As a case in
point, consider the phytoestrogenic isoflavones, which are being promoted for a
number of health benefits. Isoflavones such as genistein and daidzein can inhibit
oxidative and conjugative metabolism in vitro and interact with transporters such
as P-gp and the canalicular multispecific organic anion transporter. Given that P
gp and canalicular multispecific organic anion transporter are involved in the
intestinal absorption and biliary excretion of a wide range of drugs and
metabolites, it is reasonable to suspect that isoflavones may alter drug
disposition in humans. However, this possibility has not been explored.
PMID- 10688277
TI - Role of P-glycoprotein in drug disposition.
AB - P-glycoprotein (Pgp), which is coded by human MDR1 (multidrug resistance) gene,
is an energy-dependent efflux pump that exports its substrates out of the cell.
Human Pgp is present not only in tumor cells but also in normal tissues including
the kidney, liver, small and large intestine, brain, testis, and adrenal gland,
and the pregnant uterus. This tissue distribution indicates that Pgp plays a
significant role in excreting xenobiotics and metabolites into urine and bile and
into the intestinal lumen, and in preventing their accumulation in the brain. The
roles of Pgp in drug disposition include a urinary excretion mechanism in the
kidney, a biliary excretion mechanism in the liver, an absorption barrier and
determinant of oral bioavailability, and the blood-brain barrier that limits the
accumulation of drugs in the brain. The inhibition of the transporting function
of Pgp can cause clinically significant drug interactions and can also increase
the penetration of drugs into the brain and the accumulation of drugs in the
brain. Digoxin is a typical substrate for Pgp, which regulates the renal tubular
secretion and brain distribution of digoxin. At present, potent Pgp inhibitors
are being investigated in clinical trials aimed at overcoming the intrinsic or
acquired multidrug resistance of human cancers. The clinical application of these
Pgp inhibitors should take into consideration the physiologic function of pgp.
PMID- 10688278
TI - Evaluation of an immunoassay for mycophenolic acid.
PMID- 10688279
TI - Exercise, mobility and aging.
AB - The elderly population is growing both in size and in proportion of the total
population. The costs to the community of the elderly being in poor health are
also growing proportionately. The beneficial effects of exercise on various
physiological and psychological parameters in the elderly have been well
established. The effects of exercise on the mobility and independence of the
elderly are also of primary concern, their maintenance being an important
exercise goal. Impaired balance and gait are the 2 most significant risk factors
for limited mobility and falls in the elderly. It is important to understand the
effects of aging and exercise on these risk factors.
PMID- 10688280
TI - Evidence and possible mechanisms of altered maximum heart rate with endurance
training and tapering.
AB - Exercise physiologists, coaches and athletes have traditionally used heart rate
(HR) to monitor training intensity during exercise. While it is known that
aerobic training decreases submaximal HR (HRsubmax) at a given absolute exercise
workload, the general consensus is that maximum HR (HRmax) is relatively
unaltered regardless of training status in a given population. It has not been
seriously postulated as to whether HRmax can change modestly with aerobic
training/detraining. Despite several sources stating that HRmax is unaltered with
training, several studies report that HRmax is reduced following regular aerobic
exercise by sedentary adults and endurance athletes, and can increase upon
cessation of aerobic exercise. Furthermore, evidence suggests that
tapering/detraining can increase HRmax. Therefore, it is plausible that some of
the same mechanisms that affect both resting and HRsubmax may also play a role in
altered HRmax. Some of the proposed mechanisms for changes in HRmax that may
occur with aerobic training include autonomic (extrinsic) factors such as plasma
volume expansion and(enhanced baroreflex function, while some nonautonomic
(intrinsic) factors are alteration of the electrophysiology of the sinoatrial
(SA) node and decreased beta-adrenergic receptor number and density. There is a
high correlation between changes in both maximal oxygen uptake (VO2 max) and
HRmax that occurs with training, tapering and detraining (r= -0.76: p < 0.0001; n
= 314), which indicates that as VO2max improves with training, HRmax tends to
decrease, and when detraining ensues, HRmax tends to increase. The overall effect
of aerobic training and detraining on HRmax is moderate: effect sizes based on
several studies were calculated to be -0.48 and +0.54, respectively. Therefore,
analysis reveals that HRmax can be altered by 3 to 7% with aerobic
training/detraining. However, because of a lack of research in the area of
training on HRmax, the reader should remain speculative and allow for cautious
interpretation until further, more thorough investigations are carried out as to
the confirmation of mechanisms involved. Despite the limitations of using HR and
HRmax as a guide to training intensity, the practical implications of monitoring
changing HRmax are: (i) prescribed training intensities may be more precisely
monitored; and (ii) prevention of overtraining may possibly be enhanced. As such,
it may be sensible to monitor HRmax directly in athletes throughout the training
year, perhaps at every macrocycle (3 to 6 weeks).
PMID- 10688281
TI - Sports haematology.
AB - While the crucial role of haemoglobin in aerobic exercise has been well accepted,
there is still a great deal of controversy about the optimal haematological
parameters in the athletic population. The initial part of this review will
examine the question of anaemia in athletes. The most common finding in athletes
is a dilutional pseudoanaemia that is caused by a plasma volume expansion, rather
than an actual blood loss. It is not a pathological state and normalises with
training cessation in 3 to 5 days. This entity should be distinguished from
conditions associated with lowered blood counts, such as intravascular haemolysis
or iron deficiency anaemia. The evaluation of true anaemia states in the athlete
must take into account not only blood losses secondary to exercise, such as foot
strike haemolysis or iron losses through sweat, but non-athletic causes as well.
Depending on the age and sex of the athlete, consideration must be given to
evaluation of the gastrointestinal or genitourinary systems for blood loss.
Finally, a comprehensive nutritional history must be taken, as athletes,
especially women, are frequently not consuming adequate dietary iron. The second
section of the paper will deal with the very contentious issue of sickle cell
trait. While there have been studies demonstrating an increased risk of sudden
death in people with sickle cell trait, it is still quite rare and should not be
used as a restriction to activity. Further, studies have demonstrated that
patients with sickle cell trait have an exercise capacity that is probably normal
or near normal. However, in the cases of sudden death, it has been secondary to
rhabdomyolysis occurring among sickle cell trait athletes performing at intense
exertion under hot conditions, soon after arriving at altitude. The
recommendations are that athletes with sickle cell trait adhere to compliance
with the general guidelines for fluid replacement and acclimatisation to hot
conditions and altitude. The final section of the paper examines the issue of
haematological manipulation for the purposes of ergogenic improvement. Although
experiments with blood doping revealed improvements in running time to exhaustion
and maximal oxygen uptake, the introduction of recombinant erythropoietin has
rendered blood doping little more than a historical footnote. However, the
improvements in performance are not without risk, and the use of exogenous
erythropoietin has the potential for increased viscosity of the blood and
thrombosis with potentially fatal results. Until a definitive test is developed
for detection of exogenous erythropoietin, it will continue to be a part of elite
athletics.
PMID- 10688282
TI - The effect of hormone replacement therapy and exercise on cardiovascular disease
risk factors in postmenopausal women.
AB - Following menopause, women show an increased risk of heart disease to a level
equal that of men. This elevated risk is thought to be due, at least partly, to
changes in blood lipid and fibrinogen levels. The purpose of this article is to
review the published research on the relationship between both exercise and
hormone replacement with regards to common cardiovascular disease (CVD) risk
factors and the relative importance of each. Menopause is associated with
increased total serum cholesterol, triglycerides and fibrinogen, and a decrease
in high density lipoprotein (HDL) cholesterol levels. The major reason for these
changes following menopause is believed to be a result of fluctuations in
hormonal status, primarily a deficiency in estrogen. Intervention may be
justified since estrogen replacement therapy has been shown to decrease the risk
of developing CVD and to have a significant impact on many of the CVD risk
factors. The results vary from study to study, but generally estrogen replacement
has been found to decrease total cholesterol and fibrinogen, while increasing HDL
cholesterol and triglycerides. All of these changes, other than the increase in
triglycerides, are seen as positive. The addition of progestogen to estrogen may
negate some of the beneficial changes of estrogen, most notably the increase in
HDL cholesterol levels. However, progestogen has also been reported to offset the
increase in triglycerides seen with unopposed estrogen replacement. Thus, there
are contradictory effects (both positive and negative) of hormone replacement on
CVD risk factors in women. Regular aerobic exercise and resulting improvements in
cardiorespiratory fitness have consistently been shown as preventive of CVD. This
decreased CVD risk is in part because of the impact of exercise on blood lipids
and fibrinogen. Increased aerobic exercise is thought to improve the risk
profile, mainly through an increase in HDL cholesterol levels and decreases in
triglycerides and fibrinogen. Unfortunately, the majority of research supporting
the effects of exercise on CVD risk factors has been done on men. Even when
research has included women, very few studies have focused on postmenopausal
women. However, the research done on postmenopausal women points to a
significantly improved CVD risk factor profile with regular cardiorespiratory
exercise.
PMID- 10688283
TI - Anterior cruciate injuries in the skeletally immature athlete: a review of
treatment outcomes.
AB - The documentation of anterior cruciate ligament (ACL) injuries in the skeletally
immature athlete has significantly increased over the past decade, primarily due
to increased awareness of these injuries within this younger athletic population.
The evaluation of these injuries are similar to that in the adult population.
Diagnostic studies such as plain radiographs, as well as magnetic resonance
imaging, can delineate the location of the ACL failure. Physical presentation
most commonly includes an acute haemarthrosis and ligamentous insufficiency.
Several studies have demonstrated that the diagnostic reliability of the physical
examination is poor in children, especially in patients less than 12 years old.
The site of ACL failure in this adolescent population is most commonly at the
tibial insertion. We recommend arthroscopic or arthroscopically assisted open
reduction and internal fixation with nonabsorbable sutures for all displaced
tibial eminence fractures. Mid-substance ACL failures also occur in this athletic
age group. The association of meniscal injuries with these ACL failures appears
to be greater than 50%. Historically, poor subjective and objective outcomes have
been associated with primary and extra-articular repairs. Intra-articular
reconstruction is the gold standard. The issue of placing the graft across open
physeal plates is under investigation. Recent animal studies as well as human
clinical series have demonstrated safety in placing soft tissue, i.e. hamstring
grafts, across open growth plates without subsequent angular or leg length
discrepancy. Historically, non-operatively treated ACL failures are associated
with poor functional outcomes as well as a high incidence of meniscal re-injury.
If the treatment of an adolescent athlete with an ACL failure is to be
rehabilitation until skeletal maturity, close follow-up is essential to detect
functional instability, which may prompt earlier surgical reconstruction.
PMID- 10688284
TI - Foot injuries and arthroscopy in sport.
AB - Arthroscopy of the foot and ankle is a valuable tool for treating athletic foot
injuries. The ability to evaluate and treat injuries without an extensive open
approach is very important when dealing with the athletic population, allowing a
much quicker rehabilitation and return to sport. The diagnostic and therapeutic
indications for foot and ankle arthroscopy have increased significantly over
recent years. Techniques and instrumentation have become more advanced and more
readily available to the orthopaedist. This article defines the conditions in
which arthroscopy is appropriate and presents current techniques for treatment.
PMID- 10688285
TI - Diagnostic and procedural coding: a panacea or the promotion of mediocrity?
PMID- 10688286
TI - Custom 95 degree condylar blade plate for pediatric subtrochanteric femur
fractures.
AB - Subtrochanteric fractures in the older child and adolescent often are not
amenable to conservative methods of treatment. The anatomic constraints of the
proximal femur including the small diameter of the femoral neck and the presence
of the capital femoral physis may limit the type of internal fixation used in
these patients. This article presents our preliminary experience with a custom 95
degree condylar blade plate for subtrochanteric fractures in older children and
adolescents.
PMID- 10688287
TI - A descriptive system for lower extremity evaluation in children: data for the
newborn infant.
AB - An efficient and practical system for examination of the lower extremities in
newborn infants and children is presented. Measurements of hip rotation and
abduction are performed in a supine position. During examination, the foot is
held in passive correction or induced weight-bearing position to compare the
tibia, forefoot, and hindfoot alignment. Thirty-six newborn infants were examined
randomly to establish standard measurements for newborns. The only statistically
significant difference between male and female infants occurred in hip abduction
and internal and external rotation of the hips during extension. This method of
examination of the lower extremity in newborn infants is useful for routine
evaluation in all children.
PMID- 10688288
TI - Comparison of ender nails, dynamic hip screws, and Gamma nails in the treatment
of peritrochanteric femoral fractures.
AB - Three hundred seventy-six patients with peritrochanteric fractures treated over a
10-year period were reviewed. In 85 patients treated with Ender nailing, the most
frequent complications were leg shortening (34), external rotation failure (21),
and postoperative distal gliding of the nails (7). In 183 patients treated with
dynamic hip screws or a 95 degree condylar or a 130 degree blade plate, 3
presented with infection, 5 with instability, and 4 with femoral head necrosis.
In 105 patients treated with Gamma nailing, the most serious complications were
infections (3), inward rotation failure (2), postoperative bleeding at the
insertion site (2), and shaft fracture (1). Because of its inherent instability,
Ender nailing is no longer used. The implantation technique for the dynamic hip
screw is safer and simpler than the various models of the ASIF blade plate.
However, the dynamic hip screw has been superseded by the Gamma nail because of
its absolute stability. In the beginning, Gamma nailing was technically more
demanding with a higher number of intraoperative complications. In this study,
the number of malalignments did not differ significantly between the dynamic hip
screw (14) and the Gamma nail (11), but was high with Ender nailing (56).
PMID- 10688289
TI - Variation in hospital charges for total joint arthroplasty: an investigation of
physician efficiency.
AB - Total joint arthroplasty is a common procedure for which consistent, clinically
satisfactory outcomes are expected. Data from 796 total joint procedures
performed by 20 surgeons at one center were evaluated to identify sources of
variability in costs (as measured by hospital charges) where clinical outcome is
expected to remain constant. Stepwise multivariate regression characterized the
contribution of six variables to hospital charges listed in order of explanatory
power: postoperative length of stay, surgical time, patient preoperative
morbidity, units of blood transfused, perioperative complications, and procedure
type (hip or knee) accounted for 46% of variability in hospital charges (multiple
R2). In a subsequent analysis, after statistical adjustment for preoperative
comorbid diagnoses, the sampling distribution of mean values for surgical time,
total units of blood transfused, and total hospital charges were summarized and
compared among surgeons. Despite adjustment for comorbid diagnoses, substantial
variation and significant differences remained between surgeons in markers of
resource utilization and "surgical efficiency." These findings suggest there is
substantial variability in hospital charges not attributable to patient
characteristics or category of procedure--a distinct and economically significant
portion of this variability is practitioner specific.
PMID- 10688290
TI - Musculoskeletal trauma in tobacco farming.
AB - The incidence of musculoskeletal injury sustained during tobacco farming has been
poorly documented. Using the trauma registry for all farm-related injuries
occurring during a 16-month period, hospital charts, radiographs, and clinic
charts were reviewed to identify those patients sustaining tobacco farming
related injury. Twenty-three of 24 persons who sustained a farm-related injury
during the study period were injured while farming tobacco. Seventeen (74%) were
injured in falls from vented tobacco-drying barns, and 18 (75%) sustained
skeletal injury. Extreme heat, humidity, and poor barn design and maintenance
contribute to the incidence of falling. These injuries, largely underreported,
may be substantially reduced by improvements in barn design and construction.
PMID- 10688291
TI - Osteochondral defects of the knee.
PMID- 10688292
TI - Acrometastasis from a transitional cell carcinoma of the bladder.
PMID- 10688293
TI - Bilateral delayed extensor pollicis longus rupture following bilateral
undisplaced distal radial fractures.
PMID- 10688294
TI - Radiologic case study. Fibrous mass compressing the posterior tibial
neurovascular bundle.
PMID- 10688295
TI - Electrocardiographic imaging: a noninvasive imaging modality for characterization
of intramural myocardial activation.
PMID- 10688296
TI - Accuracy of the LocaLisa system in catheter ablation procedures.
AB - Estimation of the 3-dimensional (3D) position of ablation electrodes from
fluoroscopic images is inadequate in the ablation of complex arrhythmogenic
substrates. We developed a new technique for real-time 3D localization of
intracardiac electrodes. Regular catheter electrodes are used as sensors for a
high-frequency transthoracic electrical field, which is applied via standard skin
electrodes. We investigated localization accuracy by comparing measured and true
interelectrode distances between the tip and the 10th electrode of a decapolar
catheter, and the tip and the 4th electrode of a quadripolar catheter during
catheter ablation procedures. Long-term stability was analyzed by localization of
the proximal His bundle before and after slow pathway ablation. Accuracy achieved
with the 54-mm distance between the two outer electrodes of the decapolar
catheters was 101% +/- 15%, 95% +/- 10%, and 97% +/- 8% in the right atrium,
right ventricle, and left ventricle, respectively. During catheter ablation
procedures, the measured distance between the tip and 4th electrode of the
mapping catheter was 100% +/- 15% in atrial flutter, 100% +/- 12% in slow pathway
ablation, and 100% +/- 14% in ablations for left ventricular tachycardia. After 2
hours, localization of the proximal His bundle was reproducible within 1.4 +/-
1.1 mm. The LocaLisa technique allows for reproducible, real-time nonfluoroscopic
3D visualization of standard mapping and ablation catheters and is sufficiently
accurate for the creation of linear radiofrequency lesions. The freedom of
catheter choice makes the LocaLisa system an invaluable tool in catheter mapping
and ablation procedures.
PMID- 10688297
TI - Noncontact mapping of cardiac arrhythmias.
AB - The development of new mapping systems is beginning to overcome some of the
limitations of conventional techniques by offering percutaneous deployment,
simultaneous acquisitions of data, high-resolution maps, and correlation of
anatomy and electrophysiology, in addition to a catheter location system. The
noncontact mapping system continues to undergo development and does not
completely address all requirements for an ideal mapping system. The limitations
of the system include deterioration in the quality of electrogram reconstruction
with increasing distance between the MEA and the endocardium, the inability of
the noncontact system to identify subendocardial activation, and problems with
distinguishing noise from low-amplitude diastolic electrograms.
PMID- 10688298
TI - Use of a 3-dimensional electroanatomical mapping system for catheter ablation of
macroreentrant right atrial tachycardia following atriotomy.
AB - The purpose of this study was to utilize a 3-dimensional (3D) electroanatomical
mapping system (CARTO) to characterize the reentrant circuit in macroreentrant
right atrial tachycardia (AT) following right atriotomy. Right atrial mapping was
performed during incessant AT in a patient who had a right atriotomy for closure
of an atrial septal defect. During AT, the right atrial free wall exhibited a
large contiguous area of low bipolar voltage (< or =0.5 mV, 7.3 cm in length, and
6.3 cm in width). Two discrete scars, showing no electrical potential, were
identified within the large low-voltage area. A larger vertical scar (thought to
be from the atriotomy) and a smaller second scar (possible inferior vena cava
cannulation scar) formed a narrow channel (1.5 cm in width) between these 2
scars. Right atrial activation propagated around the large upper scar, and then
propagated through the channel between the 2 scars. A single application of
radiofrequency current within the channel eliminated the macroreentrant AT. In
conclusion, macroreentrant AT following right atriotomy was associated with 2
discrete scars and utilized the isolated channel between the 2 scars. Ablation
within the channel effectively eliminated macroreentrant AT after atriotomy and
eliminated the requirement for linear ablation between one or more of the scars
and the tricuspid annulus.
PMID- 10688299
TI - Review of methods to predict and detect atrial fibrillation in post-cardiac
surgery patients.
AB - Atrial fibrillation (AF) is the most common sustained arrhythmia after cardiac
surgery. Postoperative AF is known to substantially lengthen hospital stay and
affect patient recovery. Identification of those at risk of developing AF after
surgery and early detection of AF during recovery would be extremely helpful in
effective management of these patients, including targeting prophylactic therapy
to prevent AF in high-risk patients. In this communication, diagnostic methods to
identify those at risk of developing AF after surgery and early identification of
AF before, during, and after surgery have been reviewed. Signal-averaged P wave
analysis, done before surgery, identifies patients who are likely to develop AF
during recovery. When combined with low ejection fraction, signal-averaged P wave
can discriminate those who develop AF from those who do not. During recovery, AF
can be detected early either from a detailed analysis of atrial activity in a 10
second electrocardiogram or an analysis of R-to-R intervals from an extended
rhythm strip (1 minute or longer). Analysis of the 10-second electrocardiogram
includes median QRST subtraction from rhythm data and detection and analysis of
atrial signals in the resulting residual. AF is detected from extended rhythm
strips by using a statistical model to identify the presence of characteristic
irregular patterns of R-to-R intervals.
PMID- 10688300
TI - Comparison of 18-lead ECG and selected body surface potential mapping leads in
determining maximally deviated ST lead and efficacy in detecting acute myocardial
ischemia during coronary occlusion.
AB - Kornreich identified 6 body surface potential mapping (BSPM) leads outside the
standard 12-lead electrocardiographic (ECG) sites for optimal recognition of ST
segment elevation (+) and depression (-) during acute ischemia in anterior,
inferior, and posterior myocardial zones (A+, A-, I+, I-, P+, P-). No comparison
has been made between the 6 selected BSPM leads and 18-lead ECG (12 + V3-5R + V7
9) in detecting acute myocardial ischemia during coronary occlusion. Continuous
18-lead ECG and 6 selected BSPM leads were recorded in 68 patients (77 vessels)
undergoing coronary angioplasty during balloon occlusion. Ischemia was defined as
ST segment deviation (deltaST) > or = 100 microV > or = 1 lead from the
preinflation baseline. The 18-lead ECG was a more frequent source of the maximal
deltaST lead during left anterior descending artery, right coronary artery, and
left circumflex artery occlusion (71 [92%]) than the 6 selected BSPM leads (5
[7%]). The 18-lead ECG was more efficacious than the 6 selected BSPM leads for
detecting acute myocardial ischemia in the group as whole. The 18-lead ECG was
also more efficacious for detecting right ventricular ischemia associated with
proximal right coronary artery occlusion and for detecting ST segment elevation
during left circumflex artery occlusion. Our findings indicate that the 18-lead
ECG is the most frequent source of maximally deviated lead and is more
efficacious in detecting myocardial ischemia during balloon occlusion than the 6
selected BSPM leads. The 6 selected BSPM leads do not add information above and
beyond the 12- or 18-lead ECG, and thus cannot be recommended as optimal sites
for continuous ST segment monitoring of patients with acute coronary syndromes.
PMID- 10688301
TI - Accuracy of the EASI 12-lead electrocardiogram compared to the standard 12-lead
electrocardiogram for diagnosing multiple cardiac abnormalities.
AB - This study was performed to compare a derived 12-lead electrocardiogram (ECG)
using a simple 5-electrode lead configuration (EASI 12-lead) with the standard
ECG for multiple cardiac diagnoses. Accurate diagnosis of arrhythmias and
ischemia often require analysis of multiple (ideally, 12) ECG leads; however,
continuous 12-lead monitoring is impractical in hospital settings. EASI and
standard ECGs were compared in 540 patients, 426 of whom also had continuous 12
lead ST segment monitoring with both lead methods. Independent standards relative
to a correct diagnosis were used whenever possible, for example,
echocardiographic data for chamber enlargement-hypertrophy, and troponin levels
for acute infarction. Percent agreement between the 2 methods were: cardiac
rhythm, 100%; chamber enlargement-hypertrophy, 84%-99%; right and left bundle
branch block, 95% and 97%, respectively; left anterior and posterior fascicular
block, 97% and 99%, respectively; prior anterior and inferior infarction, 95% and
92%, respectively. There was very little variation between the 2 lead methods in
cardiac interval measurements; however, there was more variation in P, QRS, and T
wave axes. Of the 426 patients with ST monitoring, 138 patients had a total of
238 ST events (26, acute infarction; 62, angioplasty-induced ischemia; 150,
spontaneous transient ischemia). There was 100% agreement between the 2 methods
for acute infarction, 95% agreement for angioplasty-induced ischemia, and 89%
agreement for transient ischemia. EASI and standard 12-lead ECGs are comparable
for multiple cardiac diagnoses; however, serial ECG changes (eg, T-wave changes)
should be assessed using one consistent 12-lead method.
PMID- 10688302
TI - Are additional right precordial and left posterior ECG leads useful for the
diagnosis of right ventricular infarct and posterior infarct? Also a plea for the
revival of vectorcardiography.
PMID- 10688303
TI - The extended-length electrocardiogram (XL-ECG): a new tool for predicting risk of
sudden cardiac death.
PMID- 10688304
TI - Paradoxical QRST integral changes with ventricular repolarization dispersion.
AB - Body surface QRST integral (QRSTI) maps have been shown theoretically to reflect
disparity of intrinsic repolarization properties and have been experimentally
linked to increased arrhythmia susceptibility. Paradoxically, a lower magnitude
of QRSTI in patients with heart disease and at risk for arrhythmias has been
reported. We hypothesized that this paradoxical reduction in QRST magnitude is a
consequence of increased heterogeneity of repolarization gradients in normal
hearts. We generated QRSTI using a previously published heart model to compare
QRSTI for aligned and random repolarization gradients. The heart model consisted
of 50,000 cubic units in an anatomically correct arrangement that included
parameters to simulate anisotropic conduction and inhomogeneous distribution of
refractoriness. Body surface potential maps (BSPMs) were generated on a torso
surface assuming a homogeneous torso and using the boundary element method for
normal alignment of repolarization gradients and spatially reassigned
repolarization values that randomized repolarization directions. QT duration was
measured by the subtraction of Q onset time from T offset time on the BSPM. T
offset was defined as the last potential to be detected at intervals of 3 ms that
was above the threshold of 0.1 mV during recovery. The time of T offset showed a
consistent tendency to shift to the left posterior and to split. When slow
conduction velocities were assigned, BSPMs showed delayed propagation and
multiple extrema. QRSTI showed systematic magnitude decrease with increasing
randomness of repolarization gradient direction. Ventricular fibrillation (VF)
could be induced by successive extrastimuli under the conditions of over 70%
deviation and slow conduction of 0.5 m/s for the longitudinal direction. In
conclusion, a possible explanation for the paradoxical reduction in QRSTI in the
presence of constant repolarization disparity is the change in alignment of
repolarization gradients.
PMID- 10688305
TI - Detection of coronary artery disease using maximum value of ST/HR hysteresis over
different number of leads.
AB - We have studied the effect of the number and ordering of exercise
electrocardiographic (ECG) leads when using the maximum value of the ST segment
depression/heart rate (ST/HR) hysteresis over a different number of leads for the
detection of coronary artery disease (CAD). The study population consisted of 127
patients with CAD and 220 patients with a low likelihood of the disease referred
for an exercise test at Tampere University Hospital, Finland. The lead system
used was the Mason-Likar modification of the standard 12-lead system, and
exercise tests were performed on a bicycle ergometer. The number of leads was
studied using lead sets consisting of first 2 leads, then 3 leads, and so on, up
to all 12 leads. The criterion for the order of inclusion of the next lead in the
new lead set was based on the maximized area under the receiver operating
characteristic (ROC) curve for the new lead set. The importance of the number of
leads was evaluated by means of three different approaches: ROC analysis; using a
fixed partition criterion of 0.01 mV; and using a fixed specificity value of 80%.
According to the results, the most powerful diagnostic capacity of an individual
lead was in lead V5, and the most deficient diagnostic capacities were in leads
aVL and V1. Using the maximum search procedure, it was possible to improve the
diagnostic capacity of the ST/HR hysteresis by anything from 4 up to a maximum of
8 leads. After that it started to decrease rapidly. In conclusion, this study
suggests that the diagnostic capacity of the ST/HR hysteresis could be improved
by increasing the number of leads. However, the selection of leads is of major
importance when using the maximum value of the ST/HR hysteresis over the leads in
the detection of CAD.
PMID- 10688306
TI - Reentrant arrhythmias and their control in models of mammalian cardiac tissue.
AB - We use detailed biophysical and simplified models of excitation propagation in
heart muscle to study the properties of reentrant arrhythmias. Using a detailed
model of excitation combined with a bidomain description of propagation and
action of electric current, we have obtained a theoretical estimation for the
defibrillation threshold consistent with experimental data. Reentry acts as a
spiral wave, propagating around a region of block, the core. A series of properly
timed low-voltage stimuli can cause directed "resonant" drift of this block and
act as a low-voltage defibrillation strategy. Experimentally observed activation
patterns in fibrillating tissue are more complicated than the simplest spiral
wave patterns. This is due to complicated geometry, the 3-dimensional nature of
the tissue, and its anisotropy and inhomogeneity. However, some fibrillation
patterns can be produced by a single reentrant wave, modulated by inhomogeneous
tissue properties and Wenckebach frequency division.
PMID- 10688307
TI - Experimental cardiac tachyarrhythmias in guinea pigs.
AB - Despite years of intense research into the mechanisms of defibrillation, there
remain many unanswered questions. In many fields, hypotheses are first tested in
rodent models before confirming the results in larger animals. This work suggests
the guinea pig as a rodent model for defibrillation. Twenty-eight guinea pigs
were studied, all male retired breeders weighing over 900 g. T-wave stimuli
(upper limit of vulnerability [ULV]) were given after 15 rapid pacing beats,
since the rapid pacing has been suggested to extend the tachyarrhythmia.
Defibrillation (DF) was attempted after 5 seconds. The correlation between the
ULV50 and DF50 in guinea pigs (0.82, n = 8) is very close to that seen in dogs
(0.85). Also, the sensitivity of the DF50 to waveform is similar (476 +/- 176 for
monophasic vs 364 +/- 94 V for biphasic P < 0.005, n = 10). The dose-response
curve widths (2.3 +/- 1.7 for ULV vs 1.9 +/- 1.8 for defibrillation, n = 10) show
the same trend of increasing curve widths for ULV, and similar magnitude to dogs
(mean 1.8). We rarely (<1.5%) observed spontaneous conversion in less than 10
seconds. The guinea pig can be used as a model for defibrillation as it shows
many of the same characteristics as dogs.
PMID- 10688308
TI - Graded response and restitution hypotheses of ventricular vulnerability to
fibrillation: insights into the mechanism of initiation of fibrillation.
AB - According to the upper limit of vulnerability (ULV), failed defibrillation (DF)
shocks reinitiate ventricular fibrillation (VF) by falling on the vulnerable
period of one or more of the fibrillation wavefronts. The failed shock first
induces reentry (stage I VF), which within few cycles degenerate to stage II VF.
We developed 2 hypotheses of vulnerability that explain DF failure using isolated
and intact in situ ventricles. Activation maps were constructed with high
resolution electrodes and action potential (AP) recorded with microelectrodes.
According to the graded response (GR) hypothesis, reentry is formed when a
critical shock strength induces a GR that transiently increases local
refractoriness. The GR propagates and initiates distal regenerative activity that
propagates around the site of block to reenter through it as it recovers.
Ultrastrong shocks prevent reentry by converting unidirectional block to
bidirectional block by excessive increase in refractoriness, a finding that
supports the ULV hypothesis. In situ ventricle stimulus-induced termination of
reentry and stage I VF (protective zone) could be explained by the GR hypothesis.
The induced functional reentry with periods of 100 to 160 ms engages the steep
(unstable) portion of the AP duration restitution curves (slope >1) that promotes
meandering and breakup. This leads to transition from stage I to stage II VF (the
restitution hypothesis). We conclude that the GR and restitution hypotheses
provide an insight into the mechanism of ventricular vulnerability to
fibrillation induced by a stimulus. These hypotheses provide a new paradigm for
effective antifibrillatory strategies.
PMID- 10688309
TI - Arrhythmogenic changes in action potential configuration in the ventricle induced
by DC shocks.
AB - Failure of defibrillation by direct current (DC) shocks is the result in part of
new ventricular tachyarrhythmias induced by the shocks. We investigated the
arrhythmogenic substrate produced by the shocks. Fluorescent action potential
(AP) signals were recorded from rabbit hearts perfused in vitro with the use of
our original optical recording system. Localized application of 10-ms shocks (S2)
during the plateau phase of APs by basic stimuli (S1) caused field intensity (FI)
dependent changes in APs: (a) S2 > 7 V/cm caused additional depolarization,
giving rise to a prolongation of AP duration (APD); (b) With S2 > 20 V/cm,
terminal repolarization was inhibited, and subsequent postshock S1 APs for 1 to 5
min were characterized by decreases in the maximum diastolic potential and
amplitude of APs; and (c) S2 > 30 V/cm often resulted in a prolonged
refractoriness, oscillation of membrane potential leading to ventricular
tachycardia or fibrillation (VT/VF). The right ventricle was more susceptible
than other regions for the aftereffects of high-intensity shocks. Using an 8
channel recording system, we compared the effect of 10-ms monophasic (M) and 5/5
ms biphasic (B) shocks applied to the whole ventricles with FI of 1 to 20 V/cm at
the signal recording sites. B shocks were less potent than M shocks in the FI
dependent action potential duration (APD) prolongation, and in the shock-induced
enhancement of APD dispersion. Incidence and duration of VT/VF induced by M
shocks were significantly greater than those by B shocks. These findings suggest
that DC shocks will cause two types of arrhythmogenic substrate: one induced at
sites of high FI, and the other at sites with moderate FI. The former would
produce local block or focal repetitive excitation due to prolonged
depolarization and oscillation of membrane potential, and the latter circuitous
movement of wavefronts through an enhancement of spatial inhomogeneity of
repolarization.
PMID- 10688310
TI - Random nature of fibrillation leads to the probabilistic nature of
defibrillation.
PMID- 10688311
TI - Using digital versus analog ECG data in clinical trials.
AB - In 54 patients, we measured 3 different electrocardiogram (ECG) parameters
required in the Symphony 1 trial and compared various combinations of pairs of
measurements from 4 different sets of analog data and 1 set of digital data.
Particularly for measurements of the durations of R waves in lead aVF, we found
poor intraobserver and interobserver reliability and poor agreement between
analog and digital data. There was much better agreement in measurements of the
amplitudes of S waves in lead V3. The poorer agreement involving durations
appears to be due to difficulties in accurately identifying the offsets of
portions of the QRS complex, especially in lead AVF. We conclude that,
particularly in measurements of duration, digital and analog data are not
equivalent.
PMID- 10688312
TI - "Add-on" research in clinical trials: are we asking the right questions?
PMID- 10688313
TI - The use of tomographic myocardial perfusion scanning to evaluate an
electrocardiographic salvage estimation method in patients with acute myocardial
infarction: an AMISTAD substudy. Acute Myocardial Infarction Study Adenosine.
PMID- 10688314
TI - ECG subanalyses in clinical trials: an investigator's perspective.
PMID- 10688315
TI - The initial electrocardiographic pattern in acute myocardial infarction:
correlation with infarct size.
PMID- 10688316
TI - The dynamics of vortex-like reentry wave filaments in three-dimensional computer
models.
AB - Recent studies using computer simulation and biological studies in 2-dimensional
excitable media have suggested that spiral wave reentrant activation and its core
dynamics are important elements in the mechanism of functional reentrant
tachyarrhythmias, such as atrial and ventricular fibrillation. However, vortex
like reentry has been observed in homogeneous 3-dimensional excitable media, and
the dynamics of the related "filaments," which have 3-dimensionally connected
"cores" in 2 dimensions, have not been clarified. In order to determine whether
the filaments of vortex-like reentry waves can be observed in 3-dimensional media
using a mathematical ionic current heart model and whether the abnormal ionic
currents in myocardium affect the complexity of the filaments, we studied the
qualitative features of vortex-like reentry dynamics using mathematical models in
computer simulations. We employed the Luo-Rudy Phase I and the FitzHugh-Nagumo
models for our heart media, which were cubic and ventricular shaped, and
consisted of 8,000,000 and 5,636,654 myocardial units, respectively. Functional
reentry, in the form of vortex waves, was induced in the media by the S1-S2
method. The vortex-like reentry waves and their filaments were displayed by
computer graphics. Computations were performed on an NEC SX-4 supercomputer (NEC,
Tokyo, Japan) using programs written in C language. Computer simulation studies
have shown that the filament dynamics of vortex-like reentry in the original Luo
Rudy model is considerably more complex than that in the FitzHugh-Nagumo model.
However, when we mathematically modified the L-type calcium current and shortened
the action potential duration, just as occurs with sustained rapid ventricular
pacing, the dynamics of the vortex-like reentrant wave fronts and the filaments
were similar in both models. Our results suggested that the original character of
myocardium causes drastic changes in filament shape and location, resulting in
intricate functional reentrant waves, and that if the L-type calcium current is
depressed, the complexity of the dynamics of the filaments are decreased to some
degree.
PMID- 10688317
TI - Localization of intramural necrotic regions using electrocardiographic imaging.
AB - Recent studies have demonstrated that electrocardiographic imaging (ECGI) is a
novel noninvasive modality for exploring the spread of electrical activation
within the ventricular wall. In this study, our goal was to explore the ability
of ECGI in reconstructing epicardial potentials and electrograms in the
ventricles damaged by localized necroses (<2 cm2). An anatomical model of the
human ventricular myocardium was used to simulate activation sequences initiated
at 428 epicardial and endocardial pacing sites distributed over the right
ventricular and left ventricular free walls. From these realistic sequences, we
simulated extracardiac potentials at epicardial (202 sites) and torso surfaces
(352 sites) using boundary element model of the human torso. ECGI in terms of the
L-curve was applied to compute epicardial potentials and unipolar electrograms
(202 sites). Inversely computed electrograms correlated well with those simulated
by an anatomical model (r > 0.9 at 68% of sites). Specifically, ECGI accurately
reconstructed the following features that have been observed during measurements
on the exposed canine hearts: (a) an epicardial potential pattern with a central
minimum and two maxima, with the minimum positioned above the pacing site; (b) a
complete transient loss of one of the positive areas in the epicardial potential
pattern when the necrosis was located subepicardially; and (c) a transient gap in
the expanding positive areas of the epicardial potential pattern when the
necrosis was located intramurally or subendocardially. Findings of our study
indicate that ECGI provides detailed reconstruction of patterns of myocardial
activation in the presence of localized necroses and may be useful in the
assessment of arrhythmogenic substrate in the clinical setting.
PMID- 10688318
TI - Differential response of transmural dispersion of repolarization and torsade de
pointes to beta-adrenergic agonists and antagonists in three models of the long
QT syndrome.
PMID- 10688319
TI - Noninvasive indices of repolarization and its dispersion.
AB - In experimental studies using Langendorff perfused, isolated canine hearts
immersed in a torso-shaped electrolytic tank we studied repolarization and its
dispersion using direct epicardial measurements and newly derived, noninvasive
body surface indices. Activation recovery intervals (ARIs) measured from 64
epicardial sites based on differences between activation times (ATs) and recovery
times (RTs) provided direct measures of repolarization. The indirect, torso
surface indices were derived from inflections of the root-mean-square (RMS)
voltage of the torso tank surface electrocardiograms recorded simultaneously with
the epicardial data. For cycle lengths ranging from 300 to 900 ms, and
electrolyte temperatures ranging from 32 degrees C to 40 degrees C we calculated
mean, variance, and range of ATs, RTs, and ARIs from the epicardium. From
epicardial and torso surface RMS waveforms, we used times of R and T peaks and
their differences to estimate mean ATs, RTs, and ARIs, respectively. The RMS T
wave width as determined from the second derivative inflections on either side of
the T peak served as an estimate of the dispersion of RTs. In parallel studies,
we showed that the direct measures of repolarization and its dispersion were
reflected in RMS waveforms generated from the epicardial electrograms themselves.
In this study, we confirm that the torso and epicardial RMS waveforms reflect
comparable information for estimating repolarization and its dispersion.
Furthermore, the derived measures provide a method to assess mean ARIs and
dispersion of RTs on a beat-to-beat basis and during abnormal (ectopic
ventricular) activation sequences.
PMID- 10688320
TI - Transmural dispersion of repolarization and arrhythmogenicity: the Brugada
syndrome versus the long QT syndrome.
AB - Recent studies have shown that ventricular myocardium is composed of at least 3
electrophysiologically distinct cell types: epicardial, endocardial, and M cells.
Action potentials recorded from epicardial and M cells, unlike those recorded
from endocardium, display a spike-and-dome morphology, the result of a prominent
transient outward current-mediated phase 1. M cells are distinguished from
endocardial and epicardial cells by the ability of their action potential to
prolong disproportionately in response to a slowing of rate and/or to agents with
class III actions. This intrinsic electrical heterogeneity contributes to the
inscription of the electrocardiogram as well as to the development of a variety
of cardiac arrhythmias. The transmural dispersion of repolarization is in large
part responsible for the inscription of the J wave and T wave of the
electrocardiogram. Because full repolarization of epicardium defines the peak of
the T wave and that of the M cells, the end of the T wave, the interval between
the peak and the end of the T wave provides a valuable index of transmural
dispersion of repolarization. Differences in the response of the 3 cell types to
pharmacologic agents and/or pathophysiological states often results in
amplification of intrinsic electrical heterogeneities, thus providing a substrate
as well as a trigger for the development of reentrant arrhythmias, including
torsade de pointes (TdP) commonly associated with the long QT syndrome (LQTS) and
the polymorphic ventricular tachycardia/fibrillation encountered in patients with
the Brugada syndrome. Early repolarization of the epicardial action potential
results in abnormal abbreviation of action potential duration due to an all-or
none repolarization at the end of phase 1 of the epicardial action potential. The
loss of the action potential dome in epicardium but not endocardium gives rise to
a large dispersion of repolarization across the ventricular wall, resulting in a
transmural voltage gradient that manifests in the electrocardiogram as an ST
segment elevation (or idiopathic J wave). Under these conditions, heterogeneous
repolarization of the epicardial action potential gives rise to phase 2 reentry,
which provides an extrasystole capable of precipitating ventricular
tachycardia/fibrillation (or rapid TdP). Experimental models displaying these
phenomena show electrocardiographic characteristics similar to those of the
Brugada syndrome as well as those encountered during acute ischemia. Transmural
dispersion of repolarization is also greatly amplified in LQTS. Disproportionate
prolongation of the M-cell action potential contributes to the development of
long QT intervals, wide-based or notched T waves, and a large transmural
dispersion of repolarization, which provides the substrate for the development of
a polymorphic ventricular tachycardia closely resembling torsade de pointes. An
early afterdepolarization-induced triggered beat is thought to provide the
extrasystole that precipitates TdP. Pharmacologic models of the LQT1, LQT2 and
LQT3 forms of LQTS mimic the distinctive electrocardiographic,
electrophysiologic, and pharmacologic responses observed in patients with these 3
different genetic syndromes. In LQTS, as in the Brugada syndrome, a mutation in
an ion channel gene (in some cases the same gene--SCN5A) is responsible for the
development of a large transmural dispersion of repolarization, which serves to
provide the arrhythmogenic substrate tha can lead to sudden death.
PMID- 10688321
TI - Time-domain analysis of beat-to-beat variability of repolarization morphology in
patients with ischemic cardiomyopathy.
AB - There is growing evidence that beat-to-beat changes in ventricular repolarization
contribute to increased vulnerability to ventricular arrhythmias. Beat-to-beat
repolarization variability is usually measured in the electrocardiogram (ECG) by
tracking consecutive QT or RT intervals. However, these measurements strongly
depend on the accurate identification of T-wave endpoints, and they do not
reflect changes in repolarization morphology. In this article, we propose a new
computerized time-domain method to measure beat-to-beat variability of
repolarization morphology without the need to identify T-wave endpoints. The
repolarization correlation index (RCI) is computed for each beat to determine the
difference between the morphology of repolarization within a heart-rate dependent
repolarization window compared to a template (median) repolarization morphology.
The repolarization variability index (RVI) describes the mean value of
repolarization correlation in a studied ECG recording. To validate our method, we
analyzed repolarization variability in 128-beat segments from Holter ECG
recordings of 42 ischemic cardiomyopathy (ICM) patients compared to 36 healthy
subjects. The ICM patients had significantly higher values of RVI than healthy
subjects (in lead X: 0.045 +/- 0.035 vs. 0.024 +/- 0.010, respectively; P <
.001); 18 (43%) ICM patients had RVI values above the 97.5th percentile of
healthy subjects (>0.044). No significant correlation was found between the RVI
values and the magnitude of heart rate, heart rate variability, QTc interval
duration, or ejection fraction in studied ICM patients. In conclusion, our time
domain method, based on computation of repolarization correlation indices for
consecutive beats, provides a new approach to quantify beat-to-beat variability
of repolarization morphology without the need to identify T-wave endpoints.
PMID- 10688322
TI - Autonomic nerve activity and long QT interval syndrome: a role of acetylcholine
and alpha-adrenoceptor.
PMID- 10688323
TI - Cellular basis for long QT, transmural dispersion of repolarization, and torsade
de pointes in the long QT syndrome.
AB - Genetic studies have identified four forms of congenital long QT syndrome (LQTS)
caused by mutations in ion channel genes located on chromosomes 3 (LQT3), 7
(LQT2), 11 (LQT1), and 21 (LQT5). Preliminary clinical studies have reported
different phenotypic electrocardiographic patterns and different sensitivity to
pacing or pharmacological therapy for each genotype. A transmural
electrocardiogram and transmembrane action potentials from epicardial, M, and
endocardial cells were simultaneously recorded from an arterially perfused wedge
of canine left ventricle. Isoproterenol (100 nmol/L) in the presence of chromanol
293B (30 micromol/L), an I(Ks) blocker (LQT1 model), produced a preferential
prolongation of M-cell action potential duration (APD), resulting in an increase
in transmural dispersion of repolarization (TDR) and a broad-based T wave, as
commonly seen in LQT1 patients. D-Sotalol (100 micromol/L), an I(Kr) blocker
(LQT2 model), and ATX-II (20 nmol/L), an agent that augments late I(Na) (LQT3
model), also produced a preferential prolongation of M-cell APD, an increase in
TDR, and low-amplitude T wave with a bifurcated appearance (LQT2), and late
appearing T wave (LQT3), respectively. APD-, QT-, and TDR-rate relations were
much steeper in the LQT3 model than in either the LQT1 or LQT2 model, whereas the
rate relations in the LQT1 and LQT2 models were both steeper than those under
control conditions. Spontaneous and programmed electrical stimulation-induced
torsade de pointes (TdP) were observed in all 3 models. Propranolol (1
micromol/L), a beta blocker, completely prevented the effect of isoproterenol to
persistently or transiently increase TDR and to induce TdP in the LQT1 and LQT2
models, but facilitated TdP in the LQT3 model. Mexiletine, a class IB Na+ channel
blocker, dose-dependently (2-20 micromol/L) abbreviated the QT and APD more in
the LQT3 model, but decreased TDR and suppressed TdP in the 3 models.
PMID- 10688324
TI - Changes in autonomic activity and ventricular repolarization.
AB - An increase in sympathetic activity, manifested by shortening of RR intervals
(RRi) and changes in RRi variability, precedes and possibly triggers ventricular
tachyarrhythmias (VTAs) by altering repolarization. We examined the effects of
autonomic activity on the projection of repolarization as detected by body
surface potential maps (BSPMs). We recorded 32 lead/192-point BSPMs during
passive head-up tilt, tilt + infusion of isoproterenol, rapid atrial pacing, and
atrial pacing + infusion of isoproterenol. Changes in QT; recovery time;
activation-recovery interval (ARi); T-wave amplitude; and QT, QRST, and ST
integrals and their dispersion were analyzed. Autonomic effects on sinus node
were inferred from the Fourier transform-derived low and high frequency powers of
RRi variability. Patients were divided into those with (SHD) and without
structural heart disease (NSHD). Heart rate increased, whereas QT interval and
ARi declined with tilt in both groups. RRi variability indices of sympathetic
activity increased in NSHD but did not change in SHD. T-wave amplitudes declined
in NSHD but did not change in SHD, suggesting altered responsiveness of
ventricular repolarization to autonomic stimulation. Tilt and rapid atrial pacing
during infusion of isoproterenol resulted in a paradoxical increase in T-wave
amplitudes in some patients, similar to that observed before the onset of
spontaneous arrhythmias. We conclude that altering autonomic activity by head-up
tilt and/or infusion of sympathomimetic agents results in significant changes in
the body surface projection of cardiac repolarization, which differ in patients
with SHD from those without SHD. Similar paradoxical changes in the T-wave
amplitude have been observed before the onset of spontaneous VTA, suggesting that
abnormal response of repolarization to autonomic stimulation predisposes to
arrhythmogenesis.
PMID- 10688325
TI - Heart rate adjustment of ST depression in patients with coronary disease and
negative standard exercise tests.
AB - Heart rate (HR) adjustment of ST depression (STD) has been shown to correctly
classify exercise test findings in up to 85% of normal subjects and patients with
"equivocal" electrocardiographic (ECG) responses (> or =100 microV upsloping
STD), but the performance of these methods in patients with truly negative ECG
responses (<100 microV STD) has not been examined in detail. We reviewed negative
standard exercise ECGs in 54 men and women (mean age 61 years) with coronary
disease, comprising 16% of consecutive treadmill tests that were performed in 337
patients with angiographic coronary artery disease or stable angina. Mean STD was
only 63 +/- 21 microV (0.63 mm) in these negative tests. Despite these
subthreshold values for STD, the ST/HR index was abnormal (> or =1.6 microV/bpm)
in 27 of 54 patients (50%) when STD was adjusted for the change in HR during
exercise. Compared with patients with normal values for HR-adjusted STD, patients
with an abnormal ST/HR index were slightly older (64 vs. 58 years, P < 0.05) and
demonstrated a trend toward lower exercise duration (10.0 vs. 11.8 min). An
abnormal ST/HR index was associated with greater subthreshold STD (73 vs. 53
microV, P < 0.0005) and smaller HR change (35 vs. 56 bpm, P < 0.0001) with
exercise. Among the 27 patients with a normal ST/HR index by simple HR
adjustment, 11 (44%) had abnormal ST/HR slopes (> or =2.4 microV/bpm) by the more
complex linear regression method. Therefore, HR adjustment of STD contributes to
the improved sensitivity of the exercise ECG by correct classification of some
patients with truly negative standard tests. The magnitude of subthreshold STD
and the extent of HR change with exercise both contribute to improved test
performance. The increased sensitivity afforded by HR adjustment of STD
highlights the importance of the precise measurement of subthreshold STD that is
afforded by computerized ECG during exercise testing.
PMID- 10688326
TI - ST/HR hysteresis: exercise and recovery phase ST depression/heart rate analysis
of the exercise ECG.
AB - ST segment depression/heart rate (ST/HR) hysteresis is a recently introduced
novel computer method for integrating the exercise and recovery phase ST/HR
analysis for improved detection of coronary artery disease (CAD). It is a
continuous diagnostic variable that extracts the prevailing direction and average
magnitude of the hysteresis in ST depression against HR during the first 3
consecutive minutes of postexercise recovery. This article reviews the
development and evaluation of this new method in a clinical population of 347
patients referred for a routine bicycle exercise electrocardiographic (ECG) test
at Tampere University Hospital, Finland. Of these patients, 127 had
angiographically proven CAD, whereas 13 had no CAD according to angiography, 18
had no perfusion defect according to Tc-99m-sestamibi myocardial imaging and
single photon emission computed tomography, and 189 were clinically normal with
respect to cardiac diseases. For each patient, the values for ST/HR hysteresis,
ST/HR index, end-exercise ST depression, and recovery ST depression were
determined for each lead of the Mason-Likar modification of the standard 12-lead
exercise ECG and maximum value from the lead system (aVL, aVR, and V1 excluded).
The area under the receiver operating characteristics curve (ie, the
discriminative capacity) of the ST/HR hysteresis was 89%, which was significantly
larger than that of the end-exercise ST depression (76%, P < .0001), recovery ST
depression (84%, P = .0063) or ST/HR index (83%, P = .0023), indicating the best
diagnostic performance of the ST/HR hysteresis in detection of CAD regardless of
the partition value selection. Furthermore, the superior diagnostic performance
of the method was relatively insensitive to the ST segment measurement point or
to the ECG lead selection. These results suggest that the ST/HR hysteresis
improves the clinical utility of the exercise ECG test in detection of CAD.
PMID- 10688327
TI - Exercise-induced QRS prolongation in patients with mild coronary artery disease:
computer analysis of the digitized multilead ECGs.
AB - Although exercise-induced QRS prolongation has been reported as a possible marker
for inducible ischemia, subtleness of the prolongation makes it unidentifiable
from standard, chart-recorded electrocardiograms (ECGs). To overcome such a
limitation, we measured the QRS width using high-resolution ECGs and examined the
diagnostic value of the exercise-induced QRS prolongation in patients before and
after percutaneous transluminal coronary angioplasty (PTCA). In 16 patients with
single- (n = 12) or double-vessel disease (n = 4), treadmill exercise ECG tests
were performed before and after PTCA, while continuously recording 8-lead ECGs at
500 Hz. The onset of the QRS complexes was defined by the earliest deflection,
and the end was defined as the latest deflection among 8 leads with the use of
algebraic sum of the absolute voltage and their time derivatives (dV/dt) from all
8 leads. We compared QRS complexes before and 1 minute after exercise. Before
PTCA, exercise prolonged the QRS width in all but 3 patients (unchanged in 2,
decreased in 1) (84 +/- 7 to 87 +/- 8 ms, P < .005). After PTCA, it decreased in
4, was unchanged in 5, and increased in 7 (83 +/- 7 to 83 +/- 6 ms, not
significant). PTCA shortened postexercise QRS width in all but 3 (unchanged in 2,
increased in 1: 83 +/- 6 to 87 +/- 8 ms, P < .001). High-resolution ECGs enabled
us to measure subtle QRS prolongation induced by mild ischemia. Because the QRS
prolongation and ST-segment changes would reflect different aspects of myocardial
ischemia, incorporating this measure into ST segment criteria might significantly
improve the diagnostic accuracy for coronary artery disease.
PMID- 10688328
TI - Artifact processing during exercise testing.
AB - In signal processing of exercise electrocardiograms (ECGs), artifacts are a
recurring problem. It is still difficult to discriminate the ECG curves from
artifacts, especially in exercise ECGs and particularly in the high exercise
phase. We focused on the artifact problem and worked on two new topics: the
Finite Impulse Response Residual Filtering (FRF) algorithm and the Intelligent
Lead Switch algorithm. The FRF algorithm reduces the baseline wander and muscle
noise in the ECG stream, with much less distortion of the QRS complexes. It
subtracts a continuously updated median beat from the current ECG, filters the
residual signal with a high-pass and a low-pass filter, and adds the median beat
to the filtered residual signal. The Intelligent Lead Switch algorithm takes
advantage of the redundancy of a multilead system (eg, standard leads), which is
nowadays used during exercise testing. It selects the best leads for QRS
detection and thus improves the heart rate calculation, ST segment evaluation,
and arrhythmia classification.
PMID- 10688329
TI - The spirit of ISCE: dynamic interchange. Reflections on the 1998 ISCE meeting and
progress report for 1999 and future directions. Presidential talk at Nara, Japan,
1999. International Society for Computerized Electrocardiology.
PMID- 10688330
TI - Two novel anti-von Willebrand factor monoclonal antibodies.
AB - Von Willebrand Factor is a multimer produced by endothelial cells and
megakaryocytes, being stored in intracellular organelles, such as the Weibel
Palade bodies and alpha-granules in endothelial cells and platelets,
respectively. This molecule acts as a carrier protein for factor VIIIc, involved
in the intrinsic pathway of blood coagulation maintaining its stability in
circulation. Von Willebrand Factor also plays an important role in platelet
aggregation and adhesion to injured vessel wall. It interacts with platelets
through two distinct glycoproteins, GPIb and GPIIb/IIIa. We raised two monoclonal
antibodies, ECA-3 and ECA-4, against human umbilical vascular endothelial cells
that recognize and immunoprecipitate von Willebrand Factor. Interestingly, ECA-4
monoclonal antibody is able to completely inhibit platelet agglutination induced
by ristocetin, suggesting that it binds to von Willebrand Factor close to
platelet GPIb binding site. The use of monoclonal antibodies to identify von
Willebrand Factor binding regions to factor VIII or platelets has been reported
by others. In pulmonary hypertension, abnormalities have been detected on the
multimeric structure of the molecule as well as on its proteolytic fragments, by
using monoclonal antibodies. Moreover, monoclonal antibodies raised against
specific regions of von Willebrand Factor molecule may allow studies of
functional abnormalities of this protein in inherited and acquired disorders like
subtypes of von Willebrand's disease.
PMID- 10688331
TI - Influence of vortex speed on fresh versus stored platelet aggregation in the
absence and presence of extracellular ATP.
AB - Platelets are subjected to vastly differing shear forces under laminar and
nonlaminar flow patterns throughout the tortuous cardiovascular system. Different
activation pathways appear to be associated with platelet adhesion and
aggregation under high shear rates vs. low shear rates. We found that platelets
continue to aggregate at very low stirring rates (100 RPM) and low shear forces
although significantly less than at high stirring rates (1000 RPM). These
conditions may model vortices encountered in vivo, such as downstream of
partially occluded blood vessels. The extent of agonist-induced platelet
aggregation, at varying stir rates, remained essentially unchanged between 1200
and 600 RPM. This was true for both freshly prepared and stored platelets even
though the extent of aggregation was significantly reduced with stored platelets.
Agonists used were thrombin, thrombin receptor activating peptide (TRAP),
SFLLRNP, the thromboxane A2 mimetic, U46619, plus epinephrine and
ADP+epinephrine. At lower stir rates (100-400 RPM), little or no difference in
aggregation levels was observed between fresh and stored platelets, depending
upon agonist used. This may indicate that old and young platelets, in vivo, would
be equally active at vessel walls exposed to blood flowing through a slow vortex
at low shear rates. ATP, released from activated platelets, may act as a potent
regulator of platelet aggregation within a vortex where the resident time of
platelets and bioactive molecules is greater than in laminar flow regions. High
levels of extracellular ATP (100 microM) inhibited agonist-induced aggregation of
fresh platelets to a greater extent than stored platelets, except with
ADP+epinephrine where the converse was observed. Inhibition, in general, appeared
to be inversely related to stir rates. Low levels of extracellular ATP (10 nM, 1
microM) generally stimulated agonist-induced aggregations independent of stir
rates and to a greater extent with stored platelets than fresh platelets.
Unraveling how hemostasis functions within microenvironments may facilitate ways
to further regulate this process.
PMID- 10688332
TI - Defibrotide normalizes cardiovascular function hampered by established
atherosclerosis in the rabbit.
AB - In a previous paper we gave evidence that chronic oral defibrotide antagonizes
the noxious effect of developing atherosclerosis in the cardiovascular system. In
the present paper we give evidence that defibrotide is still capable of exerting
beneficial effects on cardiovascular function once atherosclerosis is
established. In fact, there was statistically significant amelioration by
defibrotide infusion in the following, all of which were hampered by established
atherosclerosis: in rabbit aorta relaxation to acetylcholine, prostaglandin E2,
and 6-keto-prostaglandin F1alpha generation from rabbit aortas, rabbit heart left
ventricular end-diastolic pressure, coronary perfusion pressure, and left
ventricular developed pressure, vasopressor activity of acetylcholine and
endothelin-1 on coronary perfusion pressure, and 6-keto-prostaglandin F1alpha
generation from the rabbit heart. Since prostacyclin takes part in NO generation,
is cellular protective, and inhibits 5-lipoxygenase product synthesis, its
increase, caused by defibrotide, could explain defibrotide cardioprotective
activity. Prostacyclin activity could be backed by prostaglandin E2, another
cardioprotective prostaglandin.
PMID- 10688333
TI - Kistrin inhibits human smooth muscle cell interaction with fibrin.
AB - Because of the lack of function-blocking anti-integrin antibodies that react with
nonprimate species, the study of the role of integrins in in vivo animal models
of atherosclerosis has been limited. In contrast, peptides or small molecules
have shown less species specificity and thus may be better tools to use. In an
attempt to identify integrin antagonists of potential use against smooth muscle
response to injury, we investigated the role of human smooth muscle cell
interactions with fibrin by using a panel of integrin antagonists consisting of
the snake venom disintegrin, Kistrin, as well as cyclic peptides with well
defined integrin antagonists activities. We demonstrate that Kistrin, a
disintegrin that inhibits beta1, beta2, beta3, and beta5 integrin interactions,
had the most potent inhibitory effect. Based on our results, Kistrin or peptides
with similar pan-integrin selectivity patterns are prime candidates for use as
anti-integrin antagonists in further studies of atherosclerosis and restenosis.
PMID- 10688334
TI - Recombinant human factor X: high yield expression and the role of furin in
proteolytic maturation in vivo and in vitro.
AB - Factor X/Xa plays a pivotal role in the coagulation cascade and exhibits a
therapeutic potential for the treatment of factor X-deficient as well as FVIII
and FIX inhibitor patients. This report describes the establishment of Chinese
hamster ovary cell clones expressing recombinant human factor X up to 120
microg/mL x day and 78 microg/10(6) cells x day, that is to 100-fold higher
levels than reported previously. Although propeptide removal and single chain
precursor to light and heavy chain processing as well as vitamin K-dependent
gamma-carboxylation became impaired at these expression levels, up to 25% of the
recombinant human factor X produced was active. This represents the highest
functional activity ever reported for a vitamin K-dependent protein at such an
expression level. Expression of recombinant human factor X in Chinese hamster
ovary cells lacking the endoprotease Furin revealed that propeptide removal still
occurred, whereas single chain precursor to light/heavy chain processing was
abolished. This suggests that a protease different from Furin mediates propeptide
removal, a unique finding compared with the other vitamin K-dependent coagulation
factors. In contrast, exposure of incompletely processed rFX molecules to soluble
recombinant Furin in vitro mediated both of these cleavage reactions despite the
absence of a typical argP4-xP3-lys/argP2-argP1 Furin cleavage site in the
propeptide, indicating relaxed specificity in vitro. Concomitantly with the
degree of processing, the functional activity of recombinant human factor X
increased. Interestingly, Furin was shown to even perform correct N-terminal
proteolytic trimming of FX molecules truncated amino-terminal to the P3 residue
in vitro. Depending on the absence or presence of warfarin in the culture media,
as well as on the processing state, four distinct recombinant human factor X
light chain isoforms were observed and their structure characterized. One of
these light chain forms correlated with the functional activity. Finally, the
distribution of the individual light chain isoforms suggests that gamma
carboxylation may be a prerequisite for propeptide removal.
PMID- 10688335
TI - The high molecular mass, glycoprotein Ib-binding protein flavocetin-A induces
only small platelet aggregates in vitro.
AB - The direct effects of snake venom glycoprotein (GP) Ib-binding proteins on
platelet receptors during the formation of platelet aggregates were determined by
a particle counting method using light scattering. Flavocetin-A induces small
platelet aggregates, but not medium or large ones. However, neither jararaca GPIb
BP nor tokaracetin induce platelet aggregation. The flavocetin-A dose-response
curve for formation of small aggregates is bell-shaped, with maximal effect at 1
to 2 microg/mL. The formation of small aggregates was not observed when fixed
human platelets were used. Jararaca GPIb-BP, the anti-GPIb monoclonal antibody
GUR83-35, prostaglandin I2, and ethylene diamine-N,N-dimethylformamide all
inhibited flavocetin-A-induced small aggregate formation, but acetylsalicylic
acid did not. Furthermore, anti-GPIIb/IIIa monoclonal antibodies, Abciximab, and
YM337 significantly but partially inhibited aggregate formation, but the anti-von
Willebrand factor monoclonal antibody NMC-4 had no effect. The formation of small
aggregates required extracellular calcium, but flavocetin-A did not elevate
cytosolic calcium. These results suggest that flavocetin-A binds to intact
platelets, initiating platelet responses and inducing platelet aggregate
formation by cross-linking platelets. Consequently, flavocetin-A may be a useful
tool to study the mechanism of GPIb-mediated platelet activation and the
structure-function relationships of GPIb.
PMID- 10688336
TI - Low plasma folate in combination with the 677 C-->T methylenetetrahydrofolate
reductase polymorphism is associated with increased risk of coronary artery
disease in Koreans.
PMID- 10688337
TI - In vitro clot lysis: a comparative study of two methods.
PMID- 10688338
TI - Clinical governance and rehabilitation services.
PMID- 10688339
TI - A double-blind placebo-controlled study of botulinum toxin in upper limb
spasticity after stroke or head injury.
AB - OBJECTIVE: To assess dose-response relationships to a single dose of botulinum
toxin 'A' in upper limb spasticity associated with stroke or head injury. DESIGN:
A double-blind placebo-controlled randomized dose ranging study. SETTING: A
regional centre for neuroscience and a neurorehabilitation outpatient clinic.
SUBJECTS: Twenty-one hemiplegic patients with troublesome upper limb spasticity.
Nineteen with stroke and two with head injury. MAIN OUTCOME MEASURES: Spasticity
(modified Ashworth), range of movement, posture (postural alignment and finger
curl), disability (upper body dressing time and Frenchay Arm Test), patient
reported global assessment scale. RESULTS: Combining data from all doses of
botulinum toxin there was a significant reduction in spasticity at the wrist and
fingers associated with a greater range of passive movement at the wrist and less
finger curl at rest. There was a tendency for a further reduction in spasticity
at elbow and wrist to occur with increasing dose but not for finger spasticity or
curl. Effects present at six weeks were lost by 12 weeks except for a small
improvement in elbow range of movement at the 1,500 Mu dose. There was no change
in upper limb disability but a significant increase in patients' global
assessment of benefit. CONCLUSION: Botulinum toxin produced beneficial effects in
spasticity and passive range of movement in the hemiplegic upper limb. Increasing
the dose increased the magnitude of response for impairments in some muscle
groups but had little effect on duration of response.
PMID- 10688340
TI - Low TENS treatment on post-stroke paretic arm: a three-year follow-up.
AB - OBJECTIVE: To determine whether stroke patients with initial increases in arm
motor recovery following low-frequency transcutaneous electrical nerve
stimulation (low TENS) treatment go on to show long-term benefits. Also whether
the same therapy results in long-term improvements in motor function, spasticity
or activities of daily living (ADL). DESIGN: A three-year follow-up study.
SUBJECTS: Twenty-eight stroke patients, who had participated in a randomized
trial of daily treatment with low-frequency (1.7 Hz) transcutaneous electrical
nerve stimulation (low TENS) on the paretic arm for three months starting 6-12
months after stroke. OUTCOMES: Fugl-Meyer Motor Performance Scale for evaluation
of changes in arm motor function. A 6-point Ashworth Scale to measure spasticity.
Barthel Index to evaluate performance in ADL. RESULTS: Motor function of the
paretic arm had deteriorated in both treatment and control groups. Increased
spasticity was seen in both groups. ADL score remained at a similar level in the
low TENS group, whereas the control group had deteriorated during the same time
period. CONCLUSIONS: Low TENS stimulation started 6-12 months after stroke may
not have a specific effect on arm motor function years after completion of
treatment.
PMID- 10688341
TI - Treatment of hemiplegic shoulder pain in the Netherlands: results of a national
survey.
AB - OBJECTIVE: To describe the methods of treatment applied by physiotherapists,
occupational therapists, rehabilitation physicians, nursing-home physicians and
neurologists for hemiplegic shoulder pain, and to investigate their beliefs about
the effectiveness of triamcinolone acetonide injections for this diagnosis.
DESIGN: Postal questionnaire with structured and open-ended questions. If
necessary, a written reminder was sent after 2-3 weeks. SUBJECTS: One hundred
physiotherapists, 100 occupational therapists, 100 rehabilitation physicians, 100
nursing-home physicians and 100 neurologists in the Netherlands. These healthcare
workers were all active in the rehabilitation of stroke patients. RESULTS: The
response was 351 (70.2%), ranging from 58% (neurologists) to 83%
(physiotherapists). Fifty-four different (combinations of) treatments were
mentioned and were classified into eight treatment groups. The frequency of the
first choice of treatment was: physiotherapy (32%),
prevention/instruction/education (22%), oral medication (8%), local injection
(7%), sling (4%), referral (3%), other therapies (4%), and different combinations
(20%). In total, 86 respondents had applied local injections: 70 rehabilitation
physicians, 10 nursing-home physicians and 6 neurologists. The injections used
were: corticosteroids alone (51.2%), in combination with a local anaesthetic
(37.2%) or a local anaesthetic only (9.3%). Belief in the effectiveness of
triamcinolone injections, measured on a 0-100 point scale, was: physiotherapists
median 62.5 (IQR 29.75-71.75), occupational therapists median 50.0 (IQR 43.0
63.0), rehabilitation physicians median 70.0 (IQR 56.5-80.0), nursing-home
physicians median 35.0 (IQR 21.0-64.5), neurologists median 47.0 (IQR 20.0-63.0).
CONCLUSIONS: As preventive measures and physiotherapy, or a combination of both,
were found to be the favourite methods of treatment for hemiplegic shoulder pain
in this survey, it seems that most physicians and therapists rely on a mechanical
approach to hemiplegic shoulder pain. Rehabilitation physicians used additional
local (anti-inflammatory) injections.
PMID- 10688342
TI - Accuracy of physical and occupational therapists' early predictions of recovery
after severe middle cerebral artery stroke.
AB - INTRODUCTION: The ability of physical therapists (PTs) and occupational
therapists (OTs) to predict level of outcome accurately was investigated
prospectively in 91 severely disabled stroke patients with a first-ever middle
cerebral artery (MCA) stroke. METHODS: Within the second and fifth week after
stroke onset, 364 predictions were made by 59 PTs and 47 OTs about walking
ability, dexterity, activities of daily living (ADL), need for additional care in
ADL, time required to achieve independent walking ability and maximal level of
ADL, and destination of discharge at six months after stroke. The functional
recovery patterns of stroke patients were assessed by an independent observer.
The accuracy of the therapists' predictions was compared with that of derived
prediction models. In addition, the influence of characteristics of patients and
therapists on the accuracy of the predictions was investigated. RESULTS: Compared
to observed outcomes at six months after stroke, therapists' lowest accuracies of
prediction were found for the moment at which maximal ADL score was achieved (rs
= 0.07; p = NS), and highest accuracy was for level of dexterity of the
hemiplegic arm (rs = 0.78; p <0.01). Therapists' predictions of functional
outcome at six months tended to be too pessimistic. No significant differences
were observed for dexterity and walking ability when the predictions by PTs and
OTs were compared with those of regression models, whereas significant
differences were found for the accuracies of OTs' and PTs' first prediction of
destination of discharge and second predictions of outcome in ADL and need for
additional care in ADL. No significant differences were found between the
accuracy of PTs' and OTs' predictions, and their ability to predict functional
outcome was not significantly influenced by the characteristics of patient and
therapists. CONCLUSIONS: At two and five weeks after stroke, OTs and PTs can
accurately predict level of walking ability and dexterity at six months. The
prediction of time required for achieving maximal level of recovery, destination
of discharge, outcome of ADL as well as need for additional care in ADL leaves
room for improvement.
PMID- 10688343
TI - A questionnaire assessment of unmet needs for rehabilitation services and
resources for people with multiple sclerosis: results of a pilot survey in five
European countries. Needs Task group of MARCH (Multiple Sclerosis and
Rehabilitation, Care and Health Services Research in Europe).
AB - OBJECTIVE: To develop an international services and needs assessment instrument
(SUN) for people with multiple sclerosis and their carers and to pilot this in
different countries of the European Community. DESIGN: Interview study of people
with multiple sclerosis, their carers and nominated key professionals examining
the unmet needs of patients and carers. SETTING: Belgium, Estonia, Greece, Italy
and the United Kingdom. MAIN OUTCOME MEASURES: Needs assessment questionnaire.
RESULTS: The study comprised 137 people with multiple sclerosis, 125 carers and
111 professionals. Patients reported on average 2.9 unmet needs for themselves;
their carers and professionals reported on average 2.4. Needs were categorized
into seven broad categories. Due to difficulties experienced by the local
researchers in distinguishing between needs and objectives a large proportion of
needs had to be assigned to the 'other' category. CONCLUSIONS: The SUN is a
valuable and practicable tool for the identification of unmet needs for people
with multiple sclerosis and their carers. Formal validation and reliability
testing of the different language versions is recommended.
PMID- 10688344
TI - The role of affect on the perception of disability in multiple sclerosis.
AB - OBJECTIVE: To determine the prevalence of depression in multiple sclerosis in the
community and to assess how the presence of depression affects patients'
perception of their disability. DESIGN: Consecutive case series. SETTING: The
study was carried out at a regional multiple sclerosis (MS) clinic. SUBJECTS:
Eighty-eight patients with MS. MAIN OUTCOME MEASURES: Patients were asked to
complete the following questionnaires: Hospital Anxiety and Depression Scale
(HADS), Beck Depression Inventory (BDI), Rankin Scale of Disability/Handicap
(completed by patient and physician to assess relative perceived disability) and
two visual analogue scales (coping ability and perceived service adequacy).
RESULTS: Thirty-nine per cent were case level for depression using the BDI
criteria of Sullivan; 17% were case level for depression (34% borderline case)
and 34% case level for anxiety on HADS. Depressed patients using both BDI and
HADS criteria were three times more likely than nondepressed patients to perceive
their disability as being greater than the physicians' perception (p < 0.001).
CONCLUSION: Depression is common in MS and adversely affects patients' perception
of their disability.
PMID- 10688345
TI - Effect of muscle length on strength and dexterity after stroke.
AB - OBJECTIVE: The effect of muscle length on strength and dexterity after stroke was
investigated. The aim was to determine if poor function at a particular muscle
length could be attributed solely to differential weakness at this joint angle or
whether an additional problem of differential dexterity exists. DESIGN: This
descriptive research study measured elbow flexor and extensor strength as well as
dexterity at three elbow joint angles: 30 degrees , 60 degrees and 90 degrees
flexion. Dexterity was measured independently of strength. SUBJECTS: Fifteen
(seven female, eight male) chronic stroke patients (mean age 67 years) who could
actively flex and extend their affected elbow participated. Ten neurologically
normal control subjects (mean age 67 years) acted as controls. MAIN OUTCOME
MEASURES: Strength was measured as peak elbow flexor and extensor torque at three
angles; and dexterity was measured as coherence for slow and fast tracking also
at three angles. RESULTS: Dexterity was not affected by muscle length but
strength was and this finding was the same for both stroke and controls. While
the magnitude of the torque-angle curves was not significantly different between
stroke and controls, the shape of torque-angle curves was altered after stroke so
that both the elbow flexors (p < 0.05) and extensors (p < 0.05) tested weaker in
the testing position where they were shortest. CONCLUSION: Since there was no
differential loss of dexterity, it appears that differential loss of strength,
especially in the shortened range, may explain the clinical observation of poorer
function at one muscle length than another after stroke. Specific training to
strengthen the muscles in these ranges is therefore of clinical importance for
rehabilitation.
PMID- 10688346
TI - A Delphi study of self-care in a community population of people with multiple
sclerosis.
AB - OBJECTIVE: The aim of the study was to obtain the views and priorities of people
with multiple sclerosis (MS) to inform the design of a professionally guided self
care programme. DESIGN: A three-round postal Delphi survey was used as a research
tool. SETTING: The study was conducted at the Centre for Research in
Rehabilitation at Brunel University in London. SUBJECTS: The respondent panel
consisted of 200 volunteers with MS of whom 136 responded to the survey (68%).
Respondents were recruited through voluntary organizations throughout the UK. The
only selection criterion was that the diagnosis of MS was confirmed by the
general practitioner. MAIN OUTCOME MEASURES: The results from each of the three
rounds of the Delphi survey were the outcome measures. RESULTS: One hundred and
one people used ten or more self-care strategies (74%). Round 1 data revealed the
diversity of practices reported, crossing many domains of life such as daily
chores, leisure, relationships and physical and mental health. The top five
priorities identified in rounds 2 and 3 concerned coping strategies, social
support, independence in daily living, rest and mobility. Complete consensus
about priorities was not achieved. However, agreement about priorities approached
stability across rounds 2 and 3 and a highly significant Kendall's coefficient of
concordance indicated there was good agreement within round 3 group rankings (W=
0.46, chi-squared = 499.37, df = 9, p<0.001, N= 122). CONCLUSION: Self-care
practices were widespread, and those most commonly used could be identified. This
survey method allows the views and priorities of this consumer group to be
revealed. The information obtained can be used to develop services where the
professional guides and encourages appropriate self-management based upon the
issues that people with MS consider to be most important.
PMID- 10688347
TI - Inter-rater reliability of the Barthel ADL index: how does a researcher compare
to a nurse?
AB - OBJECTIVES: To investigate whether a nonclinical research assistant, using
standardized scoring criteria, can reliably administer the Barthel Activities of
Daily Living (ADL) Index in a sample of elderly inpatients. DESIGN: Paired
comparison of nurse and nonclinical research assistant Barthel Index assessments.
SETTING: Acute hospital wards from two hospitals in a UK Healthcare Trust, with a
catchment population of approximately 224,000 people. METHODS: A consecutive
sample of 94 elderly patients with a variety of medical problems. MAIN OUTCOME
MEASURES: Barthel ADL Index, Folstein Mini-Mental Status Examination. RESULTS:
Whilst the inter-rater reliability of the Barthel Index was within acceptable
boundaries, two items out of ten had only fair agreement and low crude agreement
(transfer and dressing) on Cohen's kappa scores. CONCLUSIONS: Depending on the
differences observed in any particular context, the Barthel Index can be applied
with reasonable reliability by nonclinical staff applying the standardized
scoring criteria. It should be noted, however, that the kappa coefficients
between clinical and nonclinical assessors tend to be lower than those found when
comparing two clinically trained assessors in previous research.
PMID- 10688348
TI - Distribution of muscle strength impairments following stroke.
AB - OBJECTIVE: The purpose of this study was to quantify the distribution of strength
impairments soon after stroke. We were specifically interested in differences in
impairments between proximal and distal actions, flexion and extension actions,
and upper and lower limb actions. DESIGN: We conducted a retrospective chart
review of strength scores of patients with acute stroke. SETTING: Inpatient
rehabilitation unit. SUBJECTS: Forty-eight patients with a primary diagnosis of
stroke underwent initial testing on admission; 31 of the same patients underwent
final testing prior to discharge. MAIN OUTCOME MEASURES: The strength of eight
muscle actions was assessed bilaterally using hand-held dynamometry. Force
measurements obtained were expressed in newtons and as a percentage of normal.
RESULTS: Strength was impaired bilaterally but more so on the side contralateral
to the brain lesion. Distal muscle actions were less impaired than proximal
muscle actions on the stronger side. Extension actions were less impaired than
flexion actions bilaterally but primarily in the upper limbs. Upper limb actions
were less impaired than lower limb actions only on the stronger side.
CONCLUSIONS: With a few exceptions, our results do not support common clinical
assumptions regarding the distribution of strength impairments following stroke.
PMID- 10688349
TI - Ground reaction force after a sideways push as a measure of balance in recovery
from stroke.
AB - OBJECTIVE: To investigate if measuring ground reaction force after a sideways
push at the hips gives a measure of standing balance in stroke subjects. METHODS:
Fifteen control subjects and 13 right hemiparetic subjects who were able to stand
independently stood with their feet on a single forceplate. Horizontal sideways
pushes of 3% body weight were delivered to each side of the pelvis with the
subjects held firmly in a semi-rigid belt. Measurements were made of lateral
pelvic displacement (sway) and the lateral sheer component of ground reaction
force (GRF). RESULTS: Right hemiparetic subjects showed significantly greater
sway after a sideways push (p < 0.01) and later onset of GRF (p < 0.01) when
pushed to their weak side compared with control subjects. There was also a
positive correlation between sway after a sideways push and the onset latency of
GRF in both strokes (0.41) and controls (0.61). The hemiparetic subjects swayed
more (p < 0.01) when pushed to their weak side compared with their stronger side
and their GRF latency was longer, but this latter measurement failed to reach
statistical significance. No difference was seen between sides in sway or GRF
latency in controls. CONCLUSIONS: The latency of GRF onset after a push at the
hips in controls and in stroke subjects is related to sway and both measurements
increase after a stroke. This test offers a method of measuring balance after a
stroke, and serial testing of an individual after a stroke may prove a useful
measure of an individual's recovery of balance.
PMID- 10688350
TI - Relationship between timed 'up and go' and gait time in an elderly orthopaedic
rehabilitation population.
AB - OBJECTIVE: To analyse the relationship between the timed 'up and go' (TUG) and
gait time in an elderly orthopaedic population, in order to determine whether
additional useful information is obtained by measuring both. DESIGN:
Observational study. SETTING: Jewish Rehabilitation Hospital, Laval, Quebec.
SUBJECTS: Seventy-nine consecutive inpatients in the orthopaedic programme with a
primary admitting diagnosis of either total hip replacement (THR), total knee
replacement (TKR), or hip fracture repair. OUTCOME MEASURES: Timed 'up and go'
and time to walk 10 metres. RESULTS: The admission correlation between gait time
and TUG was r= 0.745. The correlation at discharge (r= 0.816) was higher than
that seen on admission. The relationship between gait time and TUG was linear
both at admission and discharge. The correlation between gait time and TUG was
strong for patients with TKR at admission (r= 0.868) and discharge (r= 0.878),
and for patients with THR, both at admission (r= 0.809) and discharge (r= 0.879).
However, the correlation on admission was weaker for patients with hip fracture
(r= 0.497). For slow walkers (people with a gait speed below 0.5 m/s) on
admission, the correlation was moderate (r= 0.649). However, for those with gait
speeds faster than or equal to 0.5 m/s, the correlation was weaker (r= 0.484).
This discrepancy was no longer evident on discharge. Likewise, for patients with
a fast TUG score (< 30 seconds) on admission, there was virtually no relationship
between TUG and gait time (r= 0.084), although a good correlation was present for
those with 'up and go' times longer than 30 seconds (r = 0.634). As with gait
speed, this difference disappeared by discharge. CONCLUSIONS: The relationship
between gait time and TUG in an elderly orthopaedic rehabilitation population is
good, and its strength varies by specific diagnosis, mobility, and time point in
the course of therapy. The two measures are not redundant in this population.
PMID- 10688351
TI - An optimization of the Waterlow score using regression and artificial neural
networks.
AB - OBJECTIVES: To optimize the ability of the Waterlow Scale to predict individuals
vulnerable to developing pressure ulcers. DESIGN: Prospective cohort study.
SETTING: Two acute care UK National Health Service (NHS) providers. SUBJECTS:
Four hundred and twenty-two inpatients across five specialities (general
medicine, general surgery, orthopaedics, oncology and rehabilitation).
INTERVENTIONS: Waterlow scores recorded weekly for 14 days post admission to
hospital. MAIN OUTCOME MEASURE: Development of a pressure ulcer. RESULTS:
Nonlinear analysis using neural networks did not outperform linear methods. Only
five items out of 11 in the Waterlow Scale appeared to have any classification
ability in this patient population. CONCLUSIONS: The Waterlow score when modelled
as a linear equation appears as effective as more complicated nonlinear mappings
using neural networks. Only a subset of the variables of the Waterlow Scale have
predictive value in this patient population, but this is a different subset to
those found in a previous study of a different client group (wheelchair users).
PMID- 10688352
TI - Case-mix in rehabilitation: FIM-based function-related groups.
PMID- 10688353
TI - Casemix in rehabilitation: the debate continues.
PMID- 10688354
TI - Case-mix in rehabilitation: a useful way to achieve a specific goal.
PMID- 10688355
TI - A new twist in trypanosome RNA metabolism: cis-splicing of pre-mRNA.
AB - It has been known for almost a decade and a half that in trypanosomes all mRNAs
are trans-spliced by addition to the 5' end of the spliced leader (SL) sequence.
During the same time period the conviction developed that classical cis-splicing
introns are not present in the trypanosome genome and that the trypanosome gene
arrangement is highly compact with small intergenic regions separating one gene
from the next. We have now discovered that these tenets are no longer true.
Poly(A) polymerase (PAP) genes in Trypanosoma brucei and Trypanosoma cruzi are
split by intervening sequences of 653 and 302 nt, respectively. The intervening
sequences occur at identical positions in both organisms and obey the GT/AG rule
of cis-splicing introns. PAP mRNAs are trans-spliced at the very 5' end as well
as internally at the 3' splice site of the intervening sequence. Interestingly,
11 nucleotide positions past the actual 5' splice site are conserved between the
T. bruceiand T. cruzi introns. Point mutations in these conserved positions, as
well as in the AG dinucleotide of the 3' splice site, abolish intron removal in
vivo. Our results, together with the recent discovery of cis-splicing introns in
Euglena gracilis, suggest that both trans- and cis-splicing are ancient
acquisitions of the eukaryotic cell.
PMID- 10688356
TI - Stem-loop 1 of the U1 snRNP plays a critical role in the suppression of HIV-1
polyadenylation.
AB - The inactivity or occlusion of the HIV-1 poly(A) signal when in the 5' long
terminal repeat (LTR) has been mechanistically investigated. First we show that
neither the homologous HIV-1 promoter nor the close proximity of this RNA
processing signal to the transcript initiation site is required for the occlusion
effect. Instead we demonstrate that the major splice donor (MSD) site positioned
about 200 bp downstream maintains the poly(A) site in an inactive state. Although
mutation of MSD results in activation of the 5' LTR poly(A) signal, this effect
can be suppressed by targeting U1 snRNAs near to the mutated MSD by base pairing.
We show that hybrid U7-U1 snRNAs can also suppress the poly(A) signal and that
this suppression is dependent on the U1 stem-loop 1. In particular the binding
site for the U1 snRNP protein 70K that binds to the loop structure of stem-loop 1
is associated with poly(A) site occlusion. These experiments were carried out
with an HIV-1 proviral construct and as such emphasize the physiological
importance of this splice donor-poly(A) site interaction.
PMID- 10688357
TI - Position-dependent inhibition of the cleavage step of pre-mRNA 3'-end processing
by U1 snRNP.
AB - The 3' ends of most eukaryotic pre-mRNAs are generated by 3' endonucleolytic
cleavage and subsequent polyadenylation. 3'-end formation can be influenced
positively or negatively by various factors. In particular, U1 snRNP acts as an
inhibitor when bound to a 5' splice site located either upstream of the 3'-end
formation signals of bovine papilloma virus (BPV) late transcripts or downstream
of the 3'-end processing signals in the 5' LTR of the HIV-1 provirus. Previous
work showed that in BPV it is not the first step, 3' cleavage, that is affected
by U1 snRNP, but rather the second step, polyadenylation, that is inhibited.
Since in HIV-1 the biological requirement is to produce transcripts that read
through the 5' LTR cleavage site rather than being cleaved there, this mechanism
seemed unlikely to apply. The obvious difference between the two examples was the
relative orientation of the 3'-end formation signals and the U1 snRNP-binding
site. In vitro assays were therefore used to assess the effect of U1 snRNP bound
at various locations relative to a cleavage/polyadenylation site on the 3'
cleavage reaction. U1 snRNP was found to inhibit cleavage when bound to a 5'
splice site downstream of the cleavage/polyadenylation site, as in the HIV-1 LTR.
U1 snRNP binding at this location was shown not to affect the recruitment of
multiple cleavage/polyadenylation factors to the cleavage substrate, indicating
that inhibition is unlikely to be due to steric hindrance. Interactions between
U1A, U1 70K, and poly(A) polymerase, which mediate the effect of U1 snRNP on
polyadenylation of other pre-mRNAs, were shown not to be required for cleavage
inhibition. Therefore, U1 snRNP bound to a 5' splice site can inhibit cleavage
and polyadenylation in two mechanistically different ways depending on whether
the 5' splice site is located upstream or downstream of the cleavage site.
PMID- 10688358
TI - Mg2+-independent hairpin ribozyme catalysis in hydrated RNA films.
AB - The hairpin ribozyme catalyzes RNA cleavage in partially hydrated RNA films in
the absence of added divalent cations. This reaction exhibits the characteristics
associated with the RNA cleavage reaction observed under standard conditions in
solution. Catalysis is a site-specific intramolecular transesterification
reaction, requires the 2'-hydroxyl group of substrate nucleotide A(-1), and
generates 2',3'-cyclic phosphate and 5'-hydroxyl termini. Mutations in both
ribozyme and substrate abolish catalysis in hydrated films. The reaction is
accelerated by cations that may enhance binding, conformational stability, and
catalytic activity, and is inhibited by Tb3+. The reaction has an apparent
temperature optimum of 4 degrees C. At this temperature, cleavage is slow
(k(obs): 2 d(-1)) and progressive, with accumulation of cleavage products to an
extent of 40%. The use of synthetic RNAs, chelators, and analysis of all reaction
components by inductively coupled plasma-optical spectrophotometry (ICPOES)
effectively rules out the possibility of contaminating divalent metals in the
reactions. Catalysis is minimal under conditions of extreme dehydration,
indicating that the reaction requires hydration of RNA by atmospheric water. Our
results provide a further caution for those studying the biochemical activity of
ribozymes in vitro and in cells, as unanticipated catalysis could occur during
RNA manipulation and lead to misinterpretation of data.
PMID- 10688359
TI - Metal ion catalysis during the exon-ligation step of nuclear pre-mRNA splicing:
extending the parallels between the spliceosome and group II introns.
AB - Mechanistic analyses of nuclear pre-mRNA splicing by the spliceosome and group II
intron self-splicing provide insight into both the catalytic strategies of
splicing and the evolutionary relationships between the different splicing
systems. We previously showed that 3'-sulfur substitution at the 3' splice site
of a nuclear pre-mRNA has no effect on splicing. We now report that 3'-sulfur
substitution at the 3' splice site of a nuclear pre-mRNA causes a switch in metal
specificity when the second step of splicing is monitored using a bimolecular
exon-ligation assay. This suggests that the spliceosome uses a catalytic metal
ion to stabilize the 3'-oxyanion leaving group during the second step of
splicing, as shown previously for the first step. The lack of a metal-specificity
switch under cis splicing conditions indicates that a rate-limiting
conformational change between the two steps of splicing may mask the subsequent
chemical step and the metal-specificity switch. As the group II intron, a true
ribozyme, uses identical catalytic strategies for splicing, our results
strengthen the argument that the spliceosome is an RNA catalyst that shares a
common molecular ancestor with group II introns.
PMID- 10688360
TI - A tertiary interaction detected in a human U2-U6 snRNA complex assembled in vitro
resembles a genetically proven interaction in yeast.
AB - U2 and U6 small nuclear RNAs are thought to play critical roles in pre-mRNA
splicing catalysis. Genetic evidence suggests they form an extensively base
paired structure within the spliceosome that is required for catalysis.
Especially in light of significant similarities with group II self-splicing
introns, we wished to investigate whether the purified RNAs might by themselves
be able to form a complex similar to that which appears to exist in the
spliceosome. To this end, we synthesized and purified large segments of human U2
and U6 snRNAs. Upon annealing, the two RNAs efficiently formed a stable and
apparently extensively base-paired (Tm = 50-60 degrees C in the presence of 20 mM
Mg2+) complex. To investigate possible tertiary interactions, we subjected the
annealed complex to UV irradiation, and two crosslinked species were identified
and characterized. The major one links the second G in the highly conserved and
critical ACAGAGA sequence in U6 with an A in U2 just 5' to U2-U6 helix Ia and
opposite the invariant AGC in U6. Remarkably, this crosslink indicates a tertiary
interaction essentially identical to one detected previously by genetic
covariation in yeast. Together our results suggest that purified U2 and U6 snRNAs
can anneal and fold to form a structure resembling that likely to exist in the
catalytically active spliceosome.
PMID- 10688361
TI - Calculation of the relative geometry of tRNAs in the ribosome from directed
hydroxyl-radical probing data.
AB - The many interactions of tRNA with the ribosome are fundamental to protein
synthesis. During the peptidyl transferase reaction, the acceptor ends of the
aminoacyl and peptidyl tRNAs must be in close proximity to allow peptide bond
formation, and their respective anticodons must base pair simultaneously with
adjacent trinucleotide codons on the mRNA. The two tRNAs in this state can be
arranged in two nonequivalent general configurations called the R and S
orientations, many versions of which have been proposed for the geometry of tRNAs
in the ribosome. Here, we report the combined use of computational analysis and
tethered hydroxyl-radical probing to constrain their arrangement. We used Fe(II)
tethered to the 5' end of anticodon stem-loop analogs (ASLs) of tRNA and to the
5' end of deacylated tRNA(Phe) to generate hydroxyl radicals that probe proximal
positions in the backbone of adjacent tRNAs in the 70S ribosome. We inferred
probe-target distances from the resulting RNA strand cleavage intensities and
used these to calculate the mutual arrangement of A-site and P-site tRNAs in the
ribosome, using three different structure estimation algorithms. The two tRNAs
are constrained to the S configuration with an angle of about 45 degrees between
the respective planes of the molecules. The terminal phosphates of 3'CCA are
separated by 23 A when using the tRNA crystal conformations, and the anticodon
arms of the two tRNAs are sufficiently close to interact with adjacent codons in
mRNA.
PMID- 10688362
TI - tRNA-guanine transglycosylase from Escherichia coli: recognition of noncognate
cognate chimeric tRNA and discovery of a novel recognition site within the TpsiC
arm of tRNA(Phe).
AB - tRNA-guanine transglycosylase (TGT) is a key enzyme involved in the
posttranscriptional modification of tRNA across the three kingdoms of life. In
eukaryotes and eubacteria, TGT is involved in the introduction of queuine into
the anticodon of the cognate tRNAs. In archaebacteria, TGT is responsible for the
introduction of archaeosine into the D-loop of the appropriate tRNAs. The tRNA
recognition patterns for the eubacterial (Escherichia coli) TGT have been
studied. These studies are all consistent with a restricted recognition motif
involving a U-G-U sequence in a seven-base loop at the end of a helix. While
attempting to investigate the potential of negative recognition elements in
noncognate tRNAs via the use of chimeric tRNAs, we have discovered a second
recognition site for the E. coli TGT in the TpsiC arm of in vitro-transcribed
yeast tRNA(Phe). Kinetic analyses of synthetic mutant oligoribonucleotides
corresponding to the TpsiC arm of the yeast tRNA(Phe) indicate that the specific
site of TGT action is G53 (within a U-G-U sequence at the transition of the TpsiC
stem into the loop). Posttranscriptional base modifications in tRNA(Phe) block
recognition by TGT, most likely due to a stabilization of the tRNA structure such
that G53 is inaccessible to TGT. These results demonstrate that TGT can recognize
the U-G-U sequence within a structural context that is different than the
canonical U-G-U in the anticodon loop of tRNA(Asp). Although it is unclear if
this second recognition site is physiologically relevant, this does suggest that
other RNA species could serve as substrates for TGT in vivo.
PMID- 10688363
TI - Deciphering the cellular pathway for transport of poly(A)-binding protein II.
AB - Poly(A)-binding protein II (PABP2) is an abundant nuclear protein that binds with
high affinity to nascent poly(A) tails, stimulating their extension and
controlling their length. In the cytoplasm, a distinct protein (PABP1) binds to
poly(A) tails and participates in mRNA translation and stability. How cytoplasmic
PABP1 substitutes for nuclear PABP2 is still unknown. Here we report that PABP2
shuttles back and forth between nucleus and cytoplasm by a carrier-mediated
mechanism. A potential novel type of nuclear localization signal exists at the C
terminus of the protein, a domain that is highly enriched in methylated
arginines. PABP2 binds directly to transportin in a RanGTP-sensitive manner,
suggesting an involvement of this transport receptor in mediating import of the
protein into the nucleus. Although PABP2 is small enough to diffuse passively
through the nuclear pores, protein fusion experiments reveal the existence of a
facilitated export pathway. Accordingly, no transport of PABP2 to the cytoplasm
occurs at 4 degrees C. In contrast, export of PABP2 continues in the absence of
transcription, indicating that transport to the cytoplasm is independent of mRNA
traffic. Thus, rather than leaving the nucleus as a passive passenger of mRNAs,
the data suggest that PABP2 interacts with the nuclear export machinery and may
therefore contribute to mRNA transport.
PMID- 10688364
TI - A phylogenetic analysis reveals an unusual sequence conservation within introns
involved in RNA editing.
AB - Adenosine deaminases that act on RNA (ADARs) are RNA editing enzymes that convert
adenosines to inosines within cellular and viral RNAs. Certain glutamate receptor
(gluR) pre-mRNAs are substrates for the enzymes in vivo. For example, at the R/G
editing site of gluR-B, -C, and -D RNAs, ADARs change an arginine codon (AGA) to
a glycine codon (IGA) so that two protein isoforms can be synthesized from a
single encoded mRNA; the highly related gluR-A sequence is not edited at this
site. To gain insight into what features of an RNA substrate are important for
accurate and efficient editing by an ADAR, we performed a phylogenetic analysis
of sequences required for editing at the R/G site. We observed highly conserved
sequences that were shared by gluR-B, -C, and -D, but absent from gluR-A.
Surprisingly, in contrast to results obtained in phylogenetic analyses of tRNA
and rRNA, it was the bases in paired, helical regions whose identity was
conserved, whereas bases in nonhelical regions varied, but maintained their
nonhelical state. We speculate this pattern in part reflects constraints imposed
by ADAR's unique specificity and gained support for our hypotheses with
mutagenesis studies. Unexpectedly, we observed that some of the gluR introns were
conserved beyond the sequences required for editing. The approximately 600-nt
intron 13 of gluR-C was particularly remarkable, showing >94% nucleotide identity
between human and chicken, organisms estimated to have diverged 310 million years
ago.
PMID- 10688365
TI - Structure of the RNA inside the vesicular stomatitis virus nucleocapsid.
AB - The structure of the viral RNA (vRNA) inside intact nucleocapsids of vesicular
stomatitis virus was studied by chemical probing experiments. Most of the Watson
Crick positions of the nucleotide bases of vRNA in intact virus and in
nucleoprotein (N)-RNA template were accessible to the chemical probes and the
phosphates were protected. This suggests that the nucleoprotein binds to the
sugar-phosphate backbone of the RNA and leaves the Watson-Crick positions free
for the transcription and replication activities of the viral RNA-dependent RNA
polymerase. The same architecture has been proposed for the influenza virus
nucleocapsids. However, about 5% of the nucleotide bases were found to be
relatively nonreactive towards the chemical probes and some bases were
hyperreactive. The pattern of reactivities was the same for RNA inside virus and
for RNA in N-RNA template that was purified over a CsCl gradient and which had
more than 94% of the polymerase and phosphoprotein molecules removed. All
reactivities were more or less equal on naked vRNA. This suggests that the
variations in reactivity towards the chemical probes are caused by the presence
of the nucleoprotein.
PMID- 10688366
TI - The leader of the HIV-1 RNA genome forms a compactly folded tertiary structure.
AB - The untranslated leader of the RNA genome of the human immunodeficiency virus
type 1 (HIV-1) encodes multiple signals that regulate distinct steps of the viral
replication cycle. The RNA secondary structure of several replicative signals in
the HIV-1 leader is critical for function. Well-known examples include the TAR
hairpin that forms the binding site for the viral Tat trans-activator protein and
the DIS hairpin that is important for dimerization and subsequent packaging of
the viral RNA into virion particles. In this study, we present evidence for the
formation of a tertiary structure by the complete HIV-1 leader RNA. This
conformer was recognized as a fast-migrating band on nondenaturing polyacrylamide
gels, and such a migration effect is generally attributed to differences in
compactness. Both the 5' and 3' domains of the 335-nt HIV-1 leader RNA are
required for the formation of the compact RNA structure, and the presence of
several putative interaction domains was revealed by an extensive analysis of the
denaturing effect of antisense DNA oligonucleotides. The buffer conditions and
sequence requirements for conformer formation are strikingly different from that
of the RNA-dimerization reaction. In particular, the conformer was destabilized
in the presence of Mg2+ ions and by the viral nucleocapsid (NC) protein. The
presence of a stable RNA structure in the HIV-1 leader was also apparent when
this RNA was used as template for reverse transcription, which yielded massive
stops ahead of the structured leader domain. Formation of the conformer is a
reversible event, suggesting that the HIV-1 leader is a dynamic molecule. The
putative biological function of this conformational polymorphism as molecular RNA
switch in the HIV-1 replication cycle is discussed.
PMID- 10688368
TI - Role of neutrophils in induction of acute inflammation in T-cell-mediated immune
dermatosis, psoriasis: a neutrophil-associated inflammation-boosting loop.
AB - A growing body of evidence has indicated that T-cell-mediated immunity plays an
important role in triggering and maintenance of psoriatic lesions. In this review
we present our own experimental results as well as those from the literature
related to the pathomechanism of the development of inflammatory changes in
psoriatic lesions. First of all it is important to acknowledge the fact that
psoriatic lesions are not uniform as assumed by many authors but that they are
actually rather heterogeneous both clinically and histologically even within the
same plaques. Lymphokines produced by activated T cells in psoriatic lesions have
a strong influence on the proliferation of the epidermis, whose stimulated
kertinocytes released several cytokines, which in turn enhance the activation
state of T cells. Thus, they form a vicious cycle, a T-cell-mediated inflammation
sustaining loop. Although the interaction between T-cell-mediated immunity and
epidermal keratinocytes may well explain the maintenance of background "chronic"
inflammatory changes diffusely observed throughout psoriatic lesions, it is not
enough to explain the island-like, "acute" inflammatory changes observed within
and at the border of the plaque lesions. Characteristic neutrophil accumulation
under the stratum corneum can be observed in the highly inflamed and
therapeutically recalcitrant areas of psoriatic lesions. They are chemotactically
attracted and activated there by synergistic action of chemokines, IL-8 and Gro-a
released by the stimulated keratinocytes, and particularly C5a/C5a des arg
produced via the alternative complement pathway activation possibly on the
surface of corneocytes. In this review, we emphasize that the accumulation of
neurophils is not simply a passive event. We think that those stimulated
neutrophils are able to influence not only the growth and differentiation of
epidermal keratinocytes but also the activation-state of T cells by aberrant
expression of HLA-DR on their surfaces as well as by their effects. These T cells
in turn influence the transepidermal neutrophil migration through the effect of
their lymphokines on the keratinocyte production of pro-inflammatory mediators
including C3. Therefore, we propose a neutrophil-associated inflammation-boosting
loop that may well explain the localized "acute" inflammatory changes scattered
over the "chronic" psoriatic plaques as well as in the acutely inflamed lesions
of pustular psoriasis.
PMID- 10688367
TI - Mapping posttranscriptional modifications in 5S ribosomal RNA by MALDI mass
spectrometry.
AB - We present a method to screen RNA for posttranscriptional modifications based on
Matrix Assisted Laser Desorption/Ionization mass spectrometry (MALDI-MS). After
the RNA is digested to completion with a nucleotide-specific RNase, the fragments
are analyzed by mass spectrometry. A comparison of the observed mass data with
the data predicted from the gene sequence identifies fragments harboring modified
nucleotides. Fragments larger than dinucleotides were valuable for the
identification of posttranscriptional modifications. A more refined mapping of
RNA modifications can be obtained by using two RNases in parallel combined with
further fragmentation by Post Source Decay (PSD). This approach allows fast and
sensitive screening of a purified RNA for posttranscriptional modification, and
has been applied on 5S rRNA from two thermophilic microorganisms, the bacterium
Bacillus stearothermophilus and the archaeon Sulfolobus acidocaldarius, as well
as the halophile archaea Halobacterium halobium and Haloarcula marismortui. One
S. acidocaldarius posttranscriptional modification was identified and was further
characterized by PSD as a methylation of cytidine32. The modified C is located in
a region that is clearly conserved with respect to both sequence and position in
B. stearothermophilus and H. halobium and to some degree also in H. marismortui.
However, no analogous modification was identified in the latter three organisms.
We further find that the 5' end of H. halobium 5S rRNA is dephosphorylated, in
contrast to the other 5S rRNA species investigated. The method additionally gives
an immediate indication of whether the expected RNA sequence is in agreement with
the observed fragment masses. Discrepancies with two of the published 5S rRNA
sequences were identified and are reported here.
PMID- 10688369
TI - Hot spot mutations in keratin 2e suggest a correlation between genotype and
phenotype in patients with ichthyosis bullosa of Siemens.
AB - Ichthyosis bullosa of Siemens (IBS) is a rare disorder of cornification
characterized by blister formation in the upper suprabasal layers of the
epidermis. Molecular analysis of IBS has identified mutations in the keratin 2e
(K2e) gene, which is located in the type II keratin gene cluster on chromosome
12q. We have studied two IBS families and have identified heterozygous point
mutations in codon 493 of the K2e gene in both families. Whereas a non
conservative amino acid substitution at position 117 of the 2B region of K2e
(E117K) was associated with a severe phenotype in family 1, family 2 showed mild
clinical features as a result of a conservative substitution (E117D). These data
suggest a phenotype-genotype correlation in these families.
PMID- 10688370
TI - Identification of a novel mutation in keratin 1 in a family with epidermolytic
hyperkeratosis.
AB - Epidermolytic hyperkeratosis (EHK) is a hereditary skin disorder typified by
blistering due to cytolysis. One in 100,000 individuals is affected by this
autosomal-dominant disease. The onset of the disease phenotype is typically at
birth. Histological and ultrastructural examination of the epidermis shows a
thickened stratum corneum and tonofilament clumping around the nucleus of
suprabasal keratinocytes. Linkage studies localized the disease genes on
chromosomes 12q and 17q which contain the type II and type I keratin gene
clusters. Recently, several point mutations in the genes encoding the suprabasal
keratins, K1 and K10, have been reported in EHK patients. We have investigated a
large kindred affected by EHK and identified a new point mutation in the 2B
region of keratin 1 (I107T), resulting from a T to C transition in codon 478.
PMID- 10688371
TI - A three-dimensional skin culture model for mouse keratinocytes: application to
transgenic mouse keratinocytes.
AB - The study of mouse epidermal biology has been hampered by the lack of a good in
vitro model for the culture of mouse keratinocytes which allowed the
reconstruction of a fully differentiated epidermis. We adapted the Prunieras'
model, also called the Dead de-Epidermized Dermis model (DED), to mouse
keratinocytes and showed that a neo-epidermis can be reconstructed exhibiting a
complete differentiation program. We also used this model to culture transgenic
mouse keratinocytes. We observed that transgene expression occurred in the
correct location and that the neo-epidermis mimed previous in vivo observations
obtained with integrin skin-targeted transgenic mice. Therefore, this model will
be a powerful tool to further investigate normal mouse and transgenic
keratinocyte biology.
PMID- 10688372
TI - Langerhans cell migration is modulated by N-sulfated glucosamine moieties in
heparin.
AB - Dendritic cell (DC) migration into and out of tissues is important for the
generation of primary immune responses to antigens encountered in tissues. In
order to study the mechanisms involved in DC migration we used a skin explant
system and quantitated the number of Langerhans cells (LC), which are immature
precursors of DC in skin-draining lymph nodes, remaining in the epidermis in
response to incubation with various biomolecules. This paper shows that LC
trafficking in epidermis is a metabolically active process that is modulated by
heparin, specifically by N-sulfated glucosamine moieties in heparin. This is the
first demonstration of structural specificity in the biochemical requirements for
DC migration in a tissue and therefore is important to understanding DC migration
in general.
PMID- 10688373
TI - Fibroblasts surrounding melanoma express elevated levels of matrix
metalloproteinase-1 (MMP-1) and intercellular adhesion molecule-1 (ICAM-1) in
vitro.
AB - Tumour growth and metastasis involve the degradation of extracellular matrix
components by matrix degrading enzymes produced by tumour cells and stromal
fibroblasts. In this study, fibroblasts were obtained from biopsies on the border
(TB) and 1 cm distant from the melanoma (TD) and cultured separately. Similar
studies were performed with fibroblasts surrounding melanocytic nevi as control.
The expression of matrix metalloproteinase-1 (MMP-1) mRNA and tissue matrix
metalloproteinase inhibitor 1 (TIMP-1) were studied by Northern blot analysis.
The activation antigen intercellular adhesion molecule-1 (ICAM-1) in TB-and TD
fibroblasts was investigated by flow cytometry. In melanoma, TB-fibroblasts
showed an increased expression of MMP-1 mRNA mainly in fibroblasts obtained from
tumours with extended invasive growth demonstrated by Clark level whereas the
expression of the major specific inhibitor TIMP-1 was unaltered. In contrast,
fibroblasts surrounding benign melanocytic nevi did not express elevated levels
of MMP-1. The upregulation of MMP-1 in TB-fibroblasts compared to TD-fibroblasts
was maintained during cultivation. Furthermore, MMP-1 mRNA expression and MMP-1
total protein amount in normal fibroblasts were increased by melanoma cell
conditioned medium. We demonstrated an increased expression of ICAM-1 in TB
fibroblasts compared to TD-fibroblasts in vitro depending on the amount of
inflammatory infiltrate in situ. The differences of ICAM expression disappeared
during continued cell culture. These results support the idea that fibroblasts
surrounding melanoma are activated and are possibly involved in the degradation
of matrix proteins surrounding the tumour.
PMID- 10688374
TI - Substance P induction of murine keratinocyte PAM 212 interleukin 1 production is
mediated by the neurokinin 2 receptor (NK-2R).
AB - The neurological system plays an important role in modulating some inflammatory
skin diseases. Neuro-cutaneous interactions may be mediated by the release of
neuropeptides such as substance P (SP) which activate immunocompetent cells in
the skin by binding to high affinity neurokinin receptors (NKR). Since epidermal
keratinocytes produce a variety of cytokines and are intimately associated with
cutaneous sensory fibers, we tested the ability of these cells to participate in
the cutaneous neuroimmune system by the secretion of potent cytokines such as
interleukin 1 (IL-1) in response to released SP. RT-PCR studies demonstrated that
cultured PAM 212 murine keratinocytes expressed mRNA for NK-2R but not NK-1R.
Correspondingly, the addition of SP to these cells resulted in a rapid increase
in intracellular Ca2+ levels that could be specifically blocked by an NK-2R
antagonist. NK-2R was also shown in normal mouse epidermis by
immunohistochemistry. SP augmented the expression of PAM 212 keratinocyte IL
1alpha mRNA in a dose and time dependent manner and this induction was inhibited
by an NK-2R antagonist. Secretion of bioactive IL-1alpha by the PAM 212
keratinocytes was likewise stimulated by SP in a dose dependent manner. These
data support the hypothesis that SP released from cutaneous sensory nerves
contributes to neuroimmune inflammatory responses in the skin by modulating the
expression and release of cytokines from epidermal keratinocytes.
PMID- 10688375
TI - Proliferation and effects of UVA irradiation in cultured fibroblasts from lesions
in cutaneous lupus erythematosus.
AB - Cutaneous lupus erythematosus (LE) often presents clinically as chronic cutaneous
lesions, healing with scar formation, and acute cutaneous lesions that are seen
in systemic and subacute LE and heal without scarring. UV-light plays a role in
the pathogenesis of the skin lesions, but the pathomechanism is still unclear.
The aim of this study was to compare fibroblast proliferation and response to UV
light by cultured fibroblasts from scarring and non-scarring LE lesions.
Fibroblasts were cultured from skin lesions from 5 patients with classic discoid
LE, 5 patients with subacute cutaneous LE and healthy, age-matched donors.
Proliferation rate was assessed by cell counts at days 3, 6 and 9. The fibroblast
cultures were irradiated with UVA and the supernatants were analysed for IL-6,
TGF-beta, IL-4, soluble ICAM-1 and soluble VCAM-1. Fibroblast cultures from
scarring lesions showed significantly lower cell-counts at days 3 (P = 0.01) and
9 (P = 0.009), than cultures from nonscarring lesions or controls. There were no
significant differences in levels of IL-6 or TGF-beta in supernatants of
irradiated fibroblasts from patients compared to controls and IL-4 and the
soluble forms of ICAM-1 and VCAM-1 were below detection level. The response to UV
irradiation was similar to that of normal cells in the parameters studied. In
summary, cultured fibroblasts from scarring LE lesions displayed significantly
decreased proliferation rates compared to non-scarring LE lesions and controls.
This may be secondary to inflammatory factors, or due to a functional defect in
LE fibroblasts.
PMID- 10688376
TI - Immunohistochemical and molecular characterization of cultured keratinocytes
after dispase-mediated detachment from the growth substratum.
AB - Keratinocyte activation comprises changes in protein and gene expression pattern
resulting in phenotypic and functional changes necessary for re-epithelialization
such as the expression of urokinase-type plasminogen activator (uPA) and its cell
surface receptor (uPA-R; CD87). As uPA and uPA-R are rapidly induced after
dispase-mediated detachment of cultured normal human epidermal keratinocytes
(NHEK) we hypothesized that dispase-mediated detachment may cause a similar
"activation" of keratinocytes with uPA and uPA-R being only one aspect of a
complex "activation reaction". To test this hypothesis we have comparatively
analysed adherent versus detached keratinocyte sheets for selected indicators of
keratinocyte activation by immunohistochemistry. Furthermore we have identified
genes via subtraction cloning which are up-regulated upon dispase-induced
detachment. The analyses provided evidence for an increased transcriptional and
translational activity in detached keratinocytes, as indicated by over-expression
of several ribosomal components (L3 and S10 ribosomal protein) and transcription
factors (initiation factor 4A, elongation factor 1alpha). Increased proliferative
activity was indicated by increased expression of the proliferation markers Ki67,
keratin 6 and keratin 17. Finally, several markers of keratinocyte activation
such as the integrin chain alpha(v), psoriasin, glutathion-S-transferase and
heparin-binding epidermal growth factor-like growth factor were up-regulated.
Furthermore mevalonate kinase, a molecule as yet unknown to be expressed in
keratinocytes, was identified. The findings provide evidence that dispase
mediated detachment in cultured keratinocytes induces a reaction, which comprises
the up-regulation of a complex array of proliferation- and migration-related
molecules. The pattern of which resembles the activation reaction observed in the
re-epithelializing keratinocytes in vivo.
PMID- 10688377
TI - Expression of stratum corneum chymotryptic enzyme in relation to other markers of
epidermal differentiation in a skin explant model.
AB - The serine proteinase stratum corneum chymotryptic enzyme (SCCE) has been
proposed to be involved in the degradation of intercellular cohesive structures
in cornified squamous epithelia in the process of desquamation. Since SCCE is
expressed late in epidermal differentiation and is found at all sites where there
is a formation of cornified epithelia it also serves as a marker for terminal
epidermal differentiation. Earlier studies have shown that the link between
expression and the formation of cornified cells may be stronger for SCCE than for
other well characterized markers of epidermal differentiation. In an attempt to
further elucidate the regulation of SCCE expression we have in this study
compared the expression of SCCE with the expression of keratin 10, filaggrin and
involucrin in an in vitro model with skin explants cultured for various periods
of time on de-epidermized dermis at the liquid-air interface. The markers were
analysed by means of immunohistochemistry. We found that the expression of SCCE
preceded the expression of keratin 10 and filaggrin. In contrast to involucrin,
which was expressed by all suprabasal keratinocytes, SCCE was expressed only by
high suprabasal cells. Our results indicate that the expression of SCCE may be
regulated in a way that differs from the regulation of the expression of keratin
10, filaggrin and involucrin.
PMID- 10688378
TI - Cytokine expression in primary cutaneous germinal center cell lymphomas.
AB - Physiologically, B-lymphocytes are not present in the skin. Even in pathological
situations they rarely occur. In contrast, primary cutaneous B-cell lymphomas
(CBCL) are characterized by proliferation of B lymphocytes within the skin. This
suggests the existence of a certain microenvironment supporting homing and
expansion of clonal B cells. Cytokines were demonstrated to be involved in the
pathogenesis of cutaneous lymphomas of T-cell origin. Cytokine expression in
cutaneous B-cell lymphoma lesions, however, has not been investigated so far.
Therefore, the mRNA level of several cytokines was analyzed in biopsies from 7
patients with CBCL and compared to pleomorphic T-cell lymphoma (n = 6), psoriasis
(n = 9), and healthy skin (n = 7), using a competitive RT-PCR approach. An
overexpression of TNF-alpha, IL-10, and IL-6 was found. Enhanced IL-8 mRNA
expression was detected in 2/7 cases. The overexpression of IL-6 and IL-10 in
CBCL might be of particular importance, since these cytokines are considered to
support B-cell growth. Additionally, the overexpression of IL-10 may contribute
to tumor progression since this immunosuppressive cytokine might be involved in
downregulation of immunological tumor surveillance, in part by inhibiting type 1
cytokine formation. In fact, we did not detect IFN-gamma and IL-2 expression.
Taken together, we found a cytokine pattern in CBCL lesions which might
contribute to tumor B-cell growth.
PMID- 10688379
TI - Computers and the pediatric surgeon: a primer.
AB - Computers have become an integral part of surgical practice. To use and maintain
computers effectively, the surgeon must have a basic knowledge of the inner
workings of the computer. It also is helpful to understand how the systems have
evolved. Medical computing started in the financial department of large
hospitals. From there it expanded to clinical data systems. Coincident with the
development of clinical data systems was the introduction of the IBM personal
computer in 1981 and the development of the Internet. All these events led to the
use of the personal computer as a communication tool. This will shape much of how
we use computers in the coming millennium. The computer is made up of several
component parts. The brain of the computer is the central processing unit (CPU),
which performs all of the calculations in the computer. The CPU works in concert
with the random access memory (RAM) and hardware peripherals to perform tasks as
directed by a program. To use this increasingly complex tool effectively, the
pediatric surgeon must have a basic knowledge of information systems. It is
through this knowledge that information systems may be used to enhance the
efficiency of pediatric surgical practice.
PMID- 10688380
TI - The Internet: past, present and future.
AB - Although the Worldwide Web has just blossomed this past decade, the origins of
the Internet date to the late 1950s and Cold War concerns. The technological
underpinning of the Internet rests with the concept of packet switching of data
over dispersed routes of electronic intercommunication. Grounded in applications
for the national defense, and nurtured in the domains of science within academia,
the Internet of the masses has exploded with the addition of strong commercial
interest and potential. Electronic mail is still the predominant application of
the Internet, and the ease of widespread and near simultaneous dissemination of
such communication has led to the genesis of listservers, especially appropriate
as well as predominant in Medicine. One such list for pediatric surgeons is
Pedsurg-L. There is an impressive evolving etiquette for those contributing to
such lists. Initiatives are already well developed with public and private
partnerships for the future of the Internet.
PMID- 10688381
TI - Internet resources and web pages for pediatric surgeons.
AB - The Internet, the largest network of connected computers, provides immediate,
dynamic, and downloadable information. By re-architecturing the work place and
becoming familiar with Internet resources, pediatric surgeons have anticipated
the informatics capabilities of this computer-based technology creating a new
vision of work and organization in such areas as patient care, teaching, and
research. This review aims to highlight how Internet navigational technology can
be a useful educational resource in pediatric surgery, examines web pages of
interest, and defines ideas of network communication. Basic Internet resources
are electronic mail, discussion groups, file transfer, and the Worldwide Web
(WWW). Electronic mailing is the most useful resource extending the avenue of
learning to an international audience through news or list-servers groups.
Pediatric Surgery List Server, the most popular discussion group, is a constant
forum for exchange of ideas, difficult cases, consensus on management, and
development of our specialty. The WWW provides an all-in-one medium of text,
image, sound, and video. Associations, departments, educational sites,
organizations, peer-reviewed scientific journals and Medline database web pages
of prime interest to pediatric surgeons have been developing at an amazing pace.
Future developments of technological advance nurturing our specialty will consist
of online journals, telemedicine, international chatting, computer-based training
for surgical education, and centralization of cyberspace information into
database search sites.
PMID- 10688382
TI - Reducing the paper load: computer-based patient records.
AB - Physicians burdened with increasing paper work may find relief in computer-based
patient records (CPR). CPRs may aid clinicians in the areas of billing,
documentation, reporting, and data retrieval. Value-added features like decision
support and event monitoring facilitate patient outcome, decrease health care
costs and allow improved administration. The authors discuss obstacles in the use
of computers in patient care with a focus on security, confidentiality, and Y2K.
PMID- 10688383
TI - Ready or not, here it comes: the legal, ethical, and clinical implications of E
mail communications.
AB - Electronic mail (E-mail) has the potential to enhance the professional
relationship both between physician and patient, and among physicians of the same
and different specialties. Despite this promise, E-mail communication in the
medical environment raises important questions of legal, ethical, and
professional propriety. This article discusses the potential uses of E-mail in
medical practice, identifies its benefits, and analyzes the hazards that may be
associated with this new and powerful technology. In doing so, the authors hope
to foster an approach to E-mail use that takes advantage of its strengths while
developing policies and practices that mitigate its weaknesses.
PMID- 10688384
TI - Clinical information systems.
AB - Clinical information systems are the computer and information systems used by
health care personnel to facilitate patient care. These systems have evolved from
financial systems to true patient care systems with variable levels of
functionality. Early systems provided laboratory and radiology results, and
modern systems now provide copies of the radiology images and decision support
for therapeutic orders. The rapidly changing technological infrastructure has
created barriers to implementation of the electronic medical record, while coding
schemes continue to be refined to enable data access and aggregate data analysis.
Further refinement of clinical information systems is required before the
potential value of these systems is realized in the clinical management of
patients.
PMID- 10688385
TI - Telemedicine and pediatric surgery.
AB - The practice of pediatric surgery has become increasingly demanding, requiring
longer working hours with less reimbursement. Although manpower in this field is
adequate, there are still areas that are underserved. Advances in technology
offer the pediatric surgeon tools to improve efficiency of practice, cover wider
areas of practice, and service underserved locations. The purpose of this report
is to introduce the pediatric surgeon to telemedicine technology and its
potential impact on the practice environment. The history, key components, and
current applications of telemedicine are presented. The ability to integrate this
technology in pediatric surgical practice holds great potential.
PMID- 10688386
TI - Comparison of bacteriologic eradication of Streptococcus pneumoniae by
clarithromycin and reports of increased antimicrobial resistance.
AB - OBJECTIVE: To determine whether reported increases in Streptococcus pneumoniae
resistance, as determined by in vitro antimicrobial susceptibility testing,
correlate with the clinical efficacy of clarithromycin in treating patients with
acute exacerbations of chronic bronchitis (AECB) or community-acquired pneumonia
(CAP). BACKGROUND: Surveillance data on antimicrobial resistance suggest that the
overall rate of S. pneumoniae resistance in vitro in the United States has
increased to approximately 45% during the past decade. S. pneumoniae is showing
increased resistance to penicillin, other beta-lactams, and macrolides. Despite
this increased resistance, the clinical efficacy of clarithromycin does not
appear to be diminished to the degree suggested by reported resistance rates. The
author examined several studies of clarithromycin in patients with AECB or CAP
that demonstrate S. pneumoniae eradication rates in vivo of approximately 92%.
The discordance between reported increases in resistance of S. pneumoniae
isolates in vitro and the eradication rate with clarithromycin in vivo is
discussed in light of 5 observations. RESULTS: First, surveillance data on S.
pneumoniae resistance rates to clarithromycin may be overestimated. Second,
efflux mutant strains may not be clinically resistant. Third, host immune
defenses play a role in treatment outcomes. Fourth, in vitro resistance may not
correlate with in vivo clinical success. Finally, clarithromycin and its active
metabolite, 14-OH-clarithromycin, attain high concentrations in patients.
CONCLUSION: Reported increases in the prevalence of S. pneumoniae resistance do
not appear to have had proportional effects on the clinical efficacy of
clarithromycin in the treatment of patients with AECB or CAP caused by S.
pneumoniae.
PMID- 10688387
TI - Weekly administration of alendronate: rationale and plan for clinical assessment.
AB - OBJECTIVE: This paper describes the rationale and supporting data for once-weekly
dosing of alendronate. BACKGROUND: Alendronate sodium, a bisphosphonate that
potently inhibits bone resorption, has been shown to increase bone mass and
substantially reduce the incidence of osteoporotic fractures, including fractures
of the hip. The standard regimen of daily administration has generally been well
tolerated. However, weekly administration may provide greater convenience to
patients without compromising efficacy or tolerability. The pharmacokinetics of
alendronate and bone remodeling theory predict similar efficacy for weekly and
daily administration if the cumulative dose is the same. Bone resorption in
individual remodeling units normally proceeds for approximately 2 weeks;
alendronate inhibits the rate and extent of resorption. Because the half-life of
residence on bone surfaces is several weeks, weekly administration of alendronate
should inhibit bone resorption to an overall extent similar to that of daily
dosing, thereby producing similar effects on bone mass and strength. Animal
studies demonstrate that both weekly and daily parenteral administration of
alendronate effectively increase bone mass and strength, but confirmation of
efficacy is needed for weekly oral dosing in humans. Although daily
bisphosphonates (alendronate and risedronate) elicited esophageal irritation in a
canine model of gastroesophageal reflux, weekly dosing with alendronate at a
higher unit dose did not. Thus, the lower frequency of weekly dosing with a
higher unit dose may actually reduce the risk of upper gastrointestinal
irritation compared with daily administration of a lower dose. CONCLUSIONS:
Current safety and efficacy data justify further investigation of once-weekly
dosing of alendronate. Two positive-control, double-blind, randomized trials of
osteoporosis treatment and prevention are currently being performed to assess the
comparability of weekly, biweekly, and daily dosing of alendronate with regard to
effects on bone density, safety, and tolerability.
PMID- 10688388
TI - Antimicrobial therapy of acute otitis media: review of treatment recommendations.
AB - OBJECTIVE: This paper reviews 3 previously published articles that provided
recommendations for antimicrobial therapy of acute otitis media (AOM) and
combines them to provide revised recommendations. BACKGROUND: AOM is one of the
most common pediatric infections requiring a prescription for an antimicrobial
agent. The optimal approach to treatment of AOM requires early, efficacious, and
practical therapy. Several experts and organizations have developed
recommendations for the management of AOM, but the number of these may overwhelm
the busy primary care practitioner. A MEDLINE search of the pediatric and
infectious disease literature on AOM treatment recommendations was used to select
3 representative, previously published articles for this review. When selecting
an agent, physicians should consider in vitro activity, particularly against drug
resistant Streptococcus pneumoniae; pharmacokinetics; adverse events;
palatability of the suspension; and cost. In addition, physicians' clinical
experience is an important determinant. CONCLUSIONS: Amoxicillin is recommended
as the first-line agent to treat uncomplicated AOM. For clinical treatment
failures after 3 days of amoxicillin, recommended antimicrobial agents include
oral amoxicillin/clavulanate, cefuroxime axetil, cefprozil, cefpodoxime proxetil,
and intramuscular (i.m.) ceftriaxone. I.m. ceftriaxone should be reserved for
severe cases or patients in whom noncompliance is expected. Tympanocentesis for
identification of pathogens and susceptibility to antimicrobial agents is
recommended for selection of third-line agents.
PMID- 10688389
TI - Tolerability and efficacy of nabumetone and naproxen in the treatment of
rheumatoid arthritis.
AB - OBJECTIVE: The purpose of this study was to compare the tolerability and efficacy
of nabumetone and naproxen in the treatment of patients with rheumatoid arthritis
(RA). The occurrence of gastrointestinal (GI) adverse events was compared.
BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) have similar efficacy
at equipotent doses, but the therapeutic response to various NSAIDs often differs
in individual patients. METHODS: This was a 3-month, randomized, double-blind,
multicenter, parallel-group study conducted in adult patients with RA. The study
had 2 phases: a 3- to 14-day washout period and a 12-week treatment period.
During the treatment phase, the tolerability and efficacy of nabumetone 2000 mg/d
were compared with those of naproxen 1000 mg/d. The change from baseline in
efficacy variables, including global assessments, number of tender or swollen
joints, and pain, was evaluated. The study was sized to provide an 80% power to
detect a 15% difference in the percentage improvement on the physician's global
assessment (alpha = 0.05). GI safety was assessed by monitoring the occurrence of
clinically important adverse GI events. RESULTS: A total of 346 RA patients at 31
US rheumatology centers were randomly assigned to treatment (173 patients per
group). The study population was predominantly white (87.0%) and female (70.5%),
with a mean age of 54 years. Both treatments improved the signs and symptoms of
RA, with no statistically significant differences between groups for any efficacy
variables. No serious GI adverse events occurred with either NSAID. The most
frequent treatment-related adverse events in both groups were predominantly GI in
origin, as were those that resulted in withdrawal from the study. Diarrhea with
lower abdominal pain was the most common adverse event in the nabumetone group;
upper abdominal pain was the most common adverse event in the naproxen group. The
only significant difference between the 2 groups was a higher incidence of
diarrhea (P < 0.01) in patients receiving nabumetone. CONCLUSIONS: Nabumetone
2000 mg/d was as effective as naproxen 1000 mg/d in relieving the signs and
symptoms of RA. In this study, no serious GI adverse events were observed with
either NSAID, but nabumetone was associated with a higher incidence of diarrhea.
PMID- 10688390
TI - Efficacy of brimonidine as replacement therapy in patients with open-angle
glaucoma or ocular hypertension.
AB - BACKGROUND: Patients with glaucoma or ocular hypertension may have inadequately
controlled intraocular pressure (IOP) or experience adverse effects with their
current medication regimens. OBJECTIVE: This post hoc reanalysis determined the
effectiveness and tolerability of brimonidine used as replacement therapy in a
real-life clinical practice setting. METHODS: In this multicenter, open-label,
observational, 2-month study, 460 patients received brimonidine 0.2% as a 1:1
replacement for another antiglaucoma medication in their current regimen.
Effectiveness was assessed by calculating the mean additional reduction in IOP
from the treated baseline measurement (before the switch to brimonidine) to 2
months postbaseline, and by determining physicians' opinions of treatment
effectiveness. Tolerability was determined based on quality-of-life assessments
and recorded adverse events. RESULTS: Overall, brimonidine replacement
significantly reduced mean (+/- SEM) IOP by an additional 2.33 +/- 0.17 mm Hg
(9.8% +/- 0.9%; P < 0.001). Significant additional reductions in IOP were seen
when brimonidine replaced an agent used either as monotherapy or adjunctive
therapy, regardless of the drug class of the agent replaced. However,
particularly good hypotensive effectiveness and additional lowering of IOP were
observed when brimonidine replaced certain medications, including latanoprost
(12.44%; P < 0.003) and betaxolol (13.56%; P < 0.001) monotherapy, and
latanoprost (16.08%; P < 0.010) adjunctive therapy. The effectiveness of
brimonidine was rated as good or excellent by 92.4% of physicians. All quality-of
life variables remained favorable or improved throughout the study, and
brimonidine treatment was well tolerated. CONCLUSIONS: Brimonidine 0.2% used as a
1:1 replacement for monotherapy or adjunctive therapy with other antiglaucoma
drugs significantly lowered IOP from that produced by previous therapy and was
well tolerated. Brimonidine offers a useful treatment option in patients who
require replacement therapy.
PMID- 10688391
TI - Pharmacokinetics and pharmacodynamics of cefepime administered by intermittent
and continuous infusion.
AB - OBJECTIVE: This study assessed the pharmacokinetics and pharmacodynamics of
cefepime administered by intermittent and continuous infusion against clinical
isolates of Pseudomonas aeruginosa, Enterobacter cloacae, and Staphylococcus
aureus. BACKGROUND: Because beta-lactam antibiotics exhibit time-dependent
bactericidal activity and lack prolonged postantibiotic effects against many
bacteria, the goal of therapy is to maintain serum drug concentrations above the
minimum inhibitory concentration (MIC) for the relevant pathogen over most of the
dosing interval. Continuous infusion is a mode of drug administration that can
provide serum drug concentrations continuously above the MIC for most bacterial
pathogens. METHODS: Twelve healthy volunteers were enrolled. Each received
cefepime 2 g by intermittent bolus q12h and, on another day, was randomly
assigned to receive 4 or 3 g administered by continuous infusion over 24 hours.
RESULTS: For the intermittent regimen, the mean (+/- SD) pharmacokinetic findings
were: maximum serum concentration, 112.9 +/- 21.1 microg/mL; minimum serum
concentration, 1.3 +/- 0.5 microg/mL; and half-life, 2.6 +/- 0.4 hours. For the 3
and 4-g continuous infusion regimens, steady-state serum concentrations (C(SS))
were 13.9 +/- 3.8 and 20.3 +/- 3.3 microg/mL, respectively. MICs ranged from 2 to
4, 0.125 to 8, and 2 to 8 microg/mL against P. aeruginosa, E. cloacae, and S.
aureus, respectively. For the intermittent regimen, serum inhibitory titers
(SITs) at 24 hours were > or = 1:2 in 46% of subjects against P. aeruginosa, 48%
against E. cloacae, and 2% against S. aureus. For both continuous infusion
regimens, SITs for each organism were > or = 1:2 in all subjects. CONCLUSIONS:
The intermittent regimen maintained serum concentrations above the MIC for P.
aeruginosa and E. cloacae in > or = 92% (11/12) of subjects for > or = 70% of the
dosing interval, provided the MIC was < or = 4 microg/mL. Both continuous
infusion regimens provided a C(SS) above the MIC for all organisms. However, the
C(SS) was > or = 4 times the MIC only if the MIC was < or = 2 microg/mL. Only the
4-g regimen provided such concentrations against isolates with an MIC of 4
microg/mL, and neither regimen provided such concentrations when the MIC was 8
microg/mL. These findings should be applied in comparative clinical studies.
PMID- 10688392
TI - Penciclovir cream for the treatment of sunlight-induced herpes simplex labialis:
a randomized, double-blind, placebo-controlled trial. Penciclovir Cream Herpes
Labialis Study Group.
AB - OBJECTIVE: The purpose of this study was to further define the therapeutic value
of penciclovir cream in the treatment of sunlight-induced herpes labialis by
comparing its efficacy and tolerability with those of an inactive control
(purified water). METHODS: In this randomized, double-blind, placebo-controlled,
parallel-group clinical trial, lesions were induced by exposure to sunlight.
Treatment was self-initiated within 1 hour of development of the signs or
symptoms of a recurrence. RESULTS: Healthy male and female patients (mean age,
38.3 years; range, 18 to 81 years) who had a history of sunlight-induced herpes
labialis (mean of 6 recurrences in previous 12 months) applied either penciclovir
cream (n = 266) or purified water (n = 275). Penciclovir cream significantly
decreased the time to lesion healing (P < 0.001), with a reduction in median time
of up to 2 days. The efficacy of penciclovir cream was further supported by a
significant reduction in maximum lesion area (P = 0.008), a faster loss of lesion
associated symptoms (P = 0.026), and significant reductions in daily assessments
of pain (P < or = 0.040), itching (P < or = 0.032), burning (P < or = 0.028), and
tenderness (P < or = 0.026) as moderate or severe. These effects were reinforced
by the results of the daily self-assessment of lesion attributes, with
significantly fewer severe/extreme assessments of lesion size (P < or = 0.003),
noticeability (P < or = 0.003), amount of scab/crust (P < or = 0.003), raised/
swollen area (P < or = 0.040), soreness/tenderness (P < or = 0.043), and overall
severity (P < or = 0.001) throughout the study period. CONCLUSIONS: Penciclovir
cream has demonstrated efficacy for a broad range of clinically important
outcomes. Significant effects on lesion area, lesion symptoms, and other lesion
attributes extend the clinical efficacy of penciclovir cream beyond lesion
healing.
PMID- 10688393
TI - Antibiotics and Clostridium difficile diarrhea in the ambulatory care setting.
AB - OBJECTIVE: The goal of this study was to determine the prevalence of Clostridium
difficile diarrhea (CDD) and the risk for CDD associated with different oral
antibiotics commonly used in the ambulatory care setting. METHODS: The prevalence
of CDD was determined for enrollees in 4 UnitedHealth Group-affiliated health
plans between January 1, 1992, and December 31, 1994. Cases were identified based
on the presence of an inpatient or outpatient claim with a primary diagnosis of
diarrhea, a pharmacy claim for a prescription drug used to treat CDD, or a
physician or facility claim for the C. difficile toxin test, and were confirmed
using full-text medical records. Within a retrospective cohort design, periods of
risk for CDD were defined on the basis of duration of antibiotic therapy. To
control for potential selection bias created by heterogeneous rates of C.
difficile testing and to limit confounding due to multiple antibiotic exposures,
we used a nested case-control design, restricting eligibility to subjects who
underwent screening for C. difficile and who had been exposed to only 1
antibiotic risk period with a single antibiotic. RESULTS: The global prevalence
of CDD in 358,389 ambulatory care enrollees was 12 per 100,000 person-years. In
the nested case-control study, after controlling for other risk factors, 2
antibiotics demonstrated an increased association with CDD: cephalexin (odds
ratio [OR] = 7.5, 95% CI = 1.8 to 34.7) and cefixime (OR = 6.4, 95% CI = 1.2 to
39.0). CONCLUSIONS: Although CDD is thought to occur primarily in hospitalized
patients, it was found to be present in an ambulatory care population, but at a
low frequency. In this population, it appeared to be associated with 2
cephalosporins but not with other types of antibiotics usually linked with
nosocomial CDD. Because the frequency of C. difficile testing was shown to be
more common with high-risk antibiotics, CDD may be underdiagnosed in the
ambulatory care setting.
PMID- 10688394
TI - Ongoing clinical assessment of the safety profile and efficacy of brimonidine
compared with timolol: year-three results. Brimonidine Study Group II.
AB - OBJECTIVE: We compared the safety profile and efficacy of brimonidine 0.2% BID
with those of timolol 0.5% BID over 3 years in patients with ocular hypertension
and glaucoma. METHODS: Ninety-four eligible patients from an ongoing multicenter,
interventional, double-masked clinical trial were followed through year 3, 48
receiving brimonidine 0.2% and 46 receiving timolol 0.5%. Study visits occurred
at months 24, 27, 30, 33, and 36. The primary efficacy variable was mean
reduction from baseline intraocular pressure (IOP) at trough. Visual acuity,
visual fields, and safety variables (adverse events, ocular symptoms, heart rate,
blood pressure, and laboratory test results) were monitored throughout the study.
RESULTS: The 2 treatment groups were well matched, with no significant
differences in demographic or clinical characteristics. Both drug regimens caused
significant mean reductions from baseline IOP at trough during year 3 (P <
0.001), with no significant differences between groups at any study visit. The
overall mean reduction from baseline IOP at trough was 5.02 mm Hg with
brimonidine and 5.57 mm Hg with timolol (P = 0.383). Brimonidine caused
reductions in IOP at trough that were equivalent to those with timolol at months
30 and 36 (within the 95% CI). Visual fields were unchanged or improved in 95% of
patients in both treatment groups. Both drug regimens appeared to be safe and
were well tolerated. Ocular allergy occurred in 2 brimonidine-treated patients
(4.2%). There were no statistically significant differences in adverse-event
reports and no clinically significant effects on any ocular or systemic safety
variable in either group. CONCLUSIONS: Brimonidine 0.2% BID continues to appear
to be safe, well tolerated, and effective in the long-term management of ocular
hypertension and glaucoma. Over 3 years, it provided sustained IOP-lowering
efficacy and visual-field preservation equal to those with timolol 0.5% BID.
PMID- 10688395
TI - Economic assessment of troglitazone as an adjunct to sulfonylurea therapy in the
treatment of type 2 diabetes.
AB - OBJECTIVE: To assess the economic efficiency of adding troglitazone to
sulfonylurea therapy to improve glycemic control. BACKGROUND: Despite the high
prevalence of type 2 diabetes, existing treatment strategies often fail. New oral
agents give a wider segment of the population with type 2 diabetes hope of
achieving near-normal blood-glucose levels. Troglitazone, a novel chemical
entity, is one promising new agent. METHODS: We conducted an economic analysis
based on glycemic-control data from a randomized clinical trial comparing
troglitazone with placebo, each added to glyburide. A patient simulation model
was used to translate these data to long-term outcomes associated with diabetes.
Patients had poorly controlled type 2 diabetes mellitus despite glyburide
therapy. Risk functions of developing and progressing through nephropathy,
retinopathy, neuropathy, hypoglycemia, and macrovascular disease were developed
from the Diabetes Control and Complications Trial and large epidemiologic
studies. Cost estimates were based on data from 5 states, all payor databases,
surveys, and literature. The main outcomes of the model were cost-consequences,
number of patients developing each type of complication, mean time to development
of the complication, cost per life-year gained (LYG), and cost per quality
adjusted life-year. RESULTS: The model predicts that for every 1000 patients
treated with troglitazone, the improved glycemic control could mean that 95 to
140 fewer patients would experience one of the most severe diabetic complications
(eg, blindness, end-stage renal disease, amputation), which may increase life
expectancy by 2.0 years. These benefits are obtained at an additional $2100 per
LYG (undiscounted). The ratio remains <$50,000 per LYG for most variations in
input. CONCLUSIONS: The clinical trial demonstrated that troglitazone + glyburide
improves glycemic control compared with glyburide alone. Based on these results,
the model estimates fewer diabetic complications at a cost well below accepted
cost-effective thresholds.
PMID- 10688396
TI - Health-related quality of life and functional status of patients with rheumatoid
arthritis randomly assigned to receive etanercept or placebo.
AB - OBJECTIVE: To compare the functional status and well-being of patients with
rheumatoid arthritis (RA) who were randomly assigned to receive placebo,
etanercept 10 mg, or etanercept 25 mg during a 26-week, phase III, double-blind
clinical trial. BACKGROUND: No single indicator of disease activity, severity, or
therapeutic efficacy has been established for RA. During the past decade, health
related quality of life, a multidimensional way to assess physical, emotional,
and social aspects of a disease or its treatment, has become an important outcome
in RA studies and in assessments of RA drug therapies. METHODS: A total of 234
patients completed the Health Assessment Questionnaire (HAQ), the Short-Form 36
(SF-36) (n = 48 patients), items assessing energy and mental health from the
Medical Outcomes Study (MOS), and a single-item rating scale assessing current
health (feeling thermometer) at baseline and several times during 6 months.
RESULTS: Significant improvements from baseline to last assessment were reported
with etanercept versus placebo and in the HAQ Disability Index score (ie, the
total HAQ score) and all 8 HAQ categories (P < 0.05), with the exception of grip.
Significant improvements with etanercept in the MOS energy and mental health
subscales, current health (from the feeling thermometer), and mental and physical
function components of the SF-36 were reported (P < 0.05). CONCLUSIONS: Patients
receiving 10- or 25-mg doses of etanercept reported significantly better
functional status and well-being than did patients receiving placebo.
PMID- 10688397
TI - Savings in direct medical costs from the use of tobramycin solution for
inhalation in patients with cystic fibrosis.
AB - OBJECTIVE: Two identical 24-week, double-blind, placebo-controlled trials of
tobramycin solution for inhalation (TOBI [PathoGenesis Corporation, Seattle,
Washington]) in cystic fibrosis patients with chronic Pseudomonas aeruginosa
infection were conducted in the United States. The aim of the present study was
to extrapolate the US trial data to a Canadian setting, using Canadian costs to
estimate the savings in direct medical costs that might result from use of a
similar 24-week TOBI regimen versus usual care in 2 Canadian provinces.
BACKGROUND: Cystic fibrosis is a genetic disease in which persistent respiratory
infection, usually due to P. aeruginosa infection, is the major cause of
morbidity and mortality. METHODS: The US trials demonstrated that TOBI produced
significant improvements in pulmonary function test results, reduced sputum
levels of P. aeruginosa, and resulted in a 26% reduction in the probability of
hospitalization (95% CI, 2%-43% vs placebo in the clinical trials). Individual
patient data from the US trials were used to calculate the mean number of days in
hospital as well as the mean number of days of home intravenous or oral
antibiotic therapy. To adjust for Canadian pricing, pertinent economic data were
obtained from Statistics Canada and the Ontario and Quebec health ministries.
Demographic and baseline data were obtained from health surveys conducted by the
Canadian Cystic Fibrosis Foundation. RESULTS: Economic analysis showed that the
use of TOBI for 24 weeks would result in estimated mean per-patient savings in
direct medical costs (in Canadian dollars) of $4055 in Ontario and $4916 in
Quebec, which would substantially offset the Canadian acquisition price of $8602
for the same 24-week period. CONCLUSIONS: Assuming that the percentage of
reduction in hospital days observed in the US trials would also occur in the
Canadian clinical setting, use of TOBI would reduce the use of health care
services, particularly hospital days, and lead to substantial savings in direct
medical costs that would offset its acquisition price. Whether this reduction
actually occurs after TOBI enters the Canadian market is a subject for future
investigation.
PMID- 10688398
TI - An overview of salt absorption by the nephron.
AB - The purpose of this brief commentary is to provide a description of how renal
physiology, and more particularly, renal tubular physiology, has evolved over the
past thirty years, since the occasion, obviously, is a celebration of the
Thirtieth Course on Advances in Nephrology and Dialysis. My arguments will begin
by quoting from Homer Smith's book, The Kidney, and merging Smith's observations,
which were integrative in the sense that they did not specify detail, with
detailed incursions into tubular physiology, first at a cellular level and then
at a molecular level. For convenience, the nephron is divided into four
functional segments: the proximal nephron; the ascending limb; the distal
nephron; and the collecting duct. Each of these carries out a specific function.
The proximal nephron absorbs about two-thirds of filtered sodium, without
dissociating salt and water absorption. The thick ascending limb absorbs 25% of
filtered Na+, but no water. The distal nephron absorbs 10% of filtered Na+ in
close relation with K+ and, to some extent, H+ secretion. Finally, the collecting
duct includes three kinds of cells: the cortical collecting duct, which is
responsible not only for Na+ absorption and K+ secretion, but also for the bulk
of the absorption of free water; the outer medullary collecting duct (OMCD),
which is largely responsible for the final steep drop in urine pH which occurs
between cortex and papilla; and the inner medullary collecting duct (IMCD), whose
major function is the final absorption of approximately 5% of filtered Na+.
PMID- 10688399
TI - Glomerular normalcy and pathosis: a "fin de millenaire" perspective.
PMID- 10688400
TI - Lupus nephritis: an historical perspective 1968-1998.
AB - Lupus is now regarded as a syndrome which results from several related auto
immune processes, although the exact mechanisms of how the disease arises in
susceptible individuals remain obscure. When the San Carlo meetings began in
1968, much less was known about the pathogenesis of autoimmunity, but the
presence of autoantibodies and autoreactive cells had been worked out, the
patterns of the disease and its clinical and histological expression in the
kidney were well described. At that time, however, the prognosis for severe forms
of lupus nephritis was miserable, although patients either milder disease might
survive for decades. During the late 1950s and 1960s relatively effective
palliative treatment first with corticosteroids and then cytotoxic drugs were
introduced, which disappointingly remain the principal treatments 40 years later,
although they have improved the prognosis of severe lupus nephritis to equal that
of milder forms. However, better understanding of the immune reaction promises
newer forms of more precisely-targeted treatment for the near future.
PMID- 10688401
TI - Polycystic kidney disease: <<30 ans apres>>.
AB - Major progress has been achieved in autosomal dominant polycystic kidney disease
in the last 30 years; Progress in imaging procedures has been decisive for
diagnosis (by ultasonography), management of kidney and liver complications (by
CT scan), and investigation and sometimes management of intracranial aneurysms
(by MRI-angiography and endovascular treatment procedures). On the other hand,
progress in molecular genetics has led to the identification of PKD1 and PDK2
genes, and their respective gene products, polycystin 1 and 2. A two-hit model
for cyst formation has recently been put forward. The link between the gene
defects and cyst fluid formation and progression is still unknown. In addition,
cystic and non-cystic lesions coexist in the disease, underlining that the
primary molecular defect is located upstream of the mechanism of cyst formation.
PMID- 10688402
TI - Demographic and organizational developments of maintenance dialysis therapies-
past, present, outlook into the future.
PMID- 10688403
TI - Mechanisms of progression of chronic renal damage.
AB - The amount of protein in the urine is a strong predictor of subsequent loss of
renal function. Proteinuria and tubular atrophy have been linked with progressive
renal insufficiency. In the last few years several studies have indicated that
smoking is also a risk factor in the progression of renal disease. In addition, a
number of studies have suggested that higher levels of blood pressure are
associated with a faster decline in renal function. A number of cytokines,
vasoactive compounds, chemoattractant molecules and growth factors are
upregulated during the course of progressive renal disease in experimental
animals. Recent data indicate that vasoconstrictor substances have a key role in
the initial phases of this process. In particular, angiotensin II is increased
following the development of renal injury. Angiotensin in turn upregulates the
expression of other factors including: transforming growth factor beta, tumor
necrosis alpha, nuclear factor kappaB and several chemoattractant compounds.
Other vasoactive compounds (endothelin, thromboxane A2 and prostaglandins) may
also be upregulated during the course of progressive renal disease
PMID- 10688404
TI - Uremic bone disease: advances over the last 30 years.
PMID- 10688405
TI - The role of technology in hemodialysis.
AB - The evolution of hemodialysis therapy has been characterized over the years by
the search for reliable devices and supplies, for more efficient treatments and
finally for a more tolerable therapy in long term dialysis patients. In this
view, three steps can be identified: a) the first step was the creation of safe
and reliable vascular access, dialyzers and machines. This step led to the birth
of modern dialysis and treatment personalization was the logical consequence.
Each patient is a single entity and he requires a specific therapy prescription
and delivery. From this concept the search for adequacy and better outcomes has
been generated, with the inevitable consequence that newer techniques were
explored in the attempt to perform a more efficient and clinically tolerated
dialysis therapy. b) The second step was the attempt to consider the
intratreatment variations as possible source for dialytic morbidity. In this
view, efforts were made to pre-set ultrafiltration and dialysate sodium profiles
in the machine to counterbalance the negative effects of uncontrolled water and
solute removal. However, this approach failed to provide significant results,
because ultrafiltration and sodium profiles were predetermined and no adaptations
could be made if the designed profile was inadequate. c) The third step in the
evolution of dialysis was the understanding that on-line signals from the machine
and from the patients were required in order to prepare and carry out the
adequate response and variation of treatment parameters. For this reason a series
of sensors have been developed including urea and blood volume sensors which are
offering the most important signals from the patient. In this way, accurate
responses could be made during treatment and from a simple manual feedback, we
have today a completely automatic form of biofeedback. The question that now
arises is where to find the financial resources to afford the upcoming
technology. Another question is whether this new technology should be for
everybody in routine dialysis or it should be designed for specific conditions.
In other words, are these toys for nice experimental studies and speculations or
are they tools to improve dialytic outcomes and morbidity? Probably, technology
cannot be stopped in its evolution. What is exceptional today will probably be
part of the routine of tomorrow. It seems that we are struggling more with the
complex physiology of human body than with mechanical or electronic problems that
certainly find their solution before or after. The increasing use of computers
and the evolution of the applied software will certainly help in reducing the
costs and improving the performances of our newer dialysis devices.
PMID- 10688406
TI - Changes in the clinical condition of haemodialysis patients.
AB - The characteristics of the dialytic population have substantially changed over
the past 30 years, becoming older and with a greater number of coexisting
diseases. The considerable evolution in treatment modalities has lead to a
significant increase in the efficacy and tolerability of dialysis. However,
physicians have to deal with illnesses in long term dialysis survivors that may
be a consequence of inadequate renal replacement therapy rather than of the
dialysis procedure per se. Cardiovascular diseases are the leading cause of death
and, although many of the risk factors are the same as in the general population
(i.e. hypertension), some appear to be specific to CRF (i.e. hyperparathyroidism,
anaemia). Age is the most important demographic factor associated with increased
mortality. The increasing incidence of ESRD diabetic patients, as well as
malnutrition, also contribute to higher mortality in RRT. The therapeutic answer
to a worsening in clinical condition is adequate medical care (starting in the
conservative phase), with particular attention being given to correcting anaemia,
hypertension, volume overload and hyperparathyroidism, and preventing
malnutrition. Treatment modalities also play a crucial role. Data suggest that
adequate dialytic dose (and possibly time) can reduce morbidity and mortality,
and on-line sodium and potassium modelling can improve intradialytic
cardiovascular stability and reduce arrhythmias. Long-term treatment with
synthetic high-flux membranes may confer some beneficial effect on beta2-m
amyloidosis-related morbidity and may also reduce mortality. Family and social
support greatly affect the quality of life of the patients. However
technologically advanced, no procedure can succeed unless it is performed in the
context of humanised health care directed towards patient needs.
PMID- 10688407
TI - Thirty years of progress in peritoneal dialysis.
PMID- 10688408
TI - Systemic hypertension and antihypertensive agents.
PMID- 10688409
TI - Renal transplantation, past, present and future.
AB - In the absence of immunosuppression, renal transplantation was sporadically and
unsuccessfully performed during the first half of this century. Over the past 40
years, immunosuppressive drug regimens have evolved greatly and transformed solid
organ transplantation into a routine clinical procedure with a 1-year graft
survival between 80% and 90%. The original immunosuppressive scheme was based on
the administration of glucocorticoids and azathioprine. However, many patients
developed acute rejection which required very high dose of prednisone. As a
consequence, a high mortality rate due to opportunistic infections was frequently
observed, since this immunosuppressive regimen nonselectively inhibited elements
of host resistance such as monocytes, granulocytes, and macrophages. In the early
Eighties, the introduction of monoclonal antibodies directed against the CD3
molecule and of cyclosporine, a lymphokine synthesis inhibitor, allowed a more
effective control of acute allograft rejection and a more specific target with
maintenance immunosuppression. Furtherly, with the knowledge of molecular
immunology the better understanding of the cellular and molecular mechanisms that
underlie the immunological response to transplanted organs, led to the discovery
of new immunosuppressive agents, such as tacrolimus, rapamycin, interleukin-2
monoclonal antibodies, and mycophenolate mofetil. All these drugs showed a more
selective mechanism for T- and B-cell alloimmune responses. The results of recent
clinical trials based on the combination of these drugs with steroids and
cyclosporine reduced the incidence of acute rejection episodes to less than 10%
and permitted a steroid-sparing policy in kidney transplantation. Today, the main
problem is related to the side-effects of vigorous and prolonged
immunosuppression, mainly infections and malignancies. If it were possible to
obtain permanent immunological tolerance, immunosuppressive therapy could be
minimized. In this respect, the new generation of drugs, FTY 20, antisense
oligonucleotides and agents capable of blocking the costimulatory pathway of
allorecognition, might have the potential of favoring tolerance in the host
against alloantigens.
PMID- 10688410
TI - Rapidly progressive glomerulonephritis.
AB - The management of rapidly progressive glomerulonephritis has been transformed
over the past thirty years. It has become one of the few forms of
glomerulonephritis that can be effectively treated, and today overall renal
survival is as high as 70%. Effective management of patients with RPGN requires
prompt and accurate diagnosis so that patients are appropriately treated, and
long term follow up to minimise the risk of relapse in patients with some types
of those disease.
PMID- 10688411
TI - Diabetic nephropathy--what have we learned in the last three decades?
AB - The past three decades have seen enormous conceptual advances in understanding
the pathogenesis of diabetic nephropathy. Increasing evidence points to important
genetic determination of the renal risk, i.e. the propensity to develop diabetic
nephropathy, in type 1 and type 2 diabetic patients. We are also further along
the path to understanding the abnormalities of renal hemodynamics that underly
these patients' propensity to develop diabetic glomerulosclerosis, i.e. afferent
arterial vasodilation and increased glomerular pressure, identified in elegant
experimental studies. Another important advance is the recognition that increased
urinary albumin excretion is not only an extremely sensitive marker, but also an
important player in the pathogenesis of diabetic nephropathy. Finally, the
concept of the toxicity of hyperglycemia ("glucotoxicity") has been carried to
the molecular level, so that pathomechanisms such as activation of protein kinase
C and cellular damage by advanced glycation endproducts (AGE), to name only two,
have been elucidated. Diabetic nephropathy has become the leading cause of
endstage renal failure (ESRF) in Western countries, particularly in patients with
type 2 diabetes. Three treatment modalities are available: (i) hemodialysis,(ii)
CAPD and (iii) transplantation, meaning kidney transplantation, combined pancreas
and kidney transplantation or - still in a very preliminary stage - islet cell
transplantation. The ideal is to have all three modalities available to meet each
patient's individual needs. Treatment outcome continues to be considerably worse,
however, in diabetic than non-diabetic patients. This highlights the importance
of prevention. Progression to ESRF in diabetic nephropathy is preventable, at
least to a large extent.
PMID- 10688412
TI - Primary glomerulonephritides with nephrotic syndrome. Limitations of therapy in
adult patients.
AB - Thirty years of clinical studies have shown that a correct therapeutic approach
to human glomerulonephritides with nephrotic syndrome requests the evaluation of
three important parameters such as renal biopsy, long monitoring of daily
proteinuria and renal function. In addition, age and clinical manifestations
should be considered. Corticosteroids, alkylating agents (cyclophosphamide,
chlorambucil) and purine analogues are currently used in the treatment of primary
glomerulonephritis (minimal-change disease (MCD), focal segmental
glomerulosclerosis (FSGS), membranous (MGN) and membranoproliferative
glomerulonephritis (MPGN)), however results are different. Patients with
nephrotic syndrome in MCD when treated with corticosteroids and/or cytotoxic
drugs have complete or partial remission in a more than 90% of cases. On the
contrary, nephrotic FSGS remits completely or partially only in 50% of treated
cases when a more aggressive and prolonged immunosuppressive therapy is carried
out. Data from clinical trials in MGN patients are controversial, however it is
evident that a greater percentage of patients with stage 1 and stage 2 renal
lesions benefit from corticosteroids in association with immunosuppressive drugs.
Finally, no encouraging data have been obtained by clinically controlled trials
in patients with MPGN. Future perspectives suggest the use of other drugs such as
receptor blockade of cytokines and growth factors, administration of cytokine
antagonists, intracellular signalling blockade and gene therapy with antisense
oligonucleotides. Unfortunately, until specific therapies become available, we
have to use unspecific or only symptomatic therapy.
PMID- 10688413
TI - Pathogenesis of glomerulonephritis, a perspective from the last 30 years.
PMID- 10688414
TI - Pathophysiology of acute renal failure.
AB - Acute renal failure (ARF) is a common renal disease affecting up to 5% of all
hospitalized patients, with a higher prevalence of 10-30% in patients in critical
care units (1-3). Despite advances in the management of critically ill patients
and technological advances in renal replacement therapy, the high mortality of
patients with ARF has not changed over the last decades and remains above 50% (4
6). Moreover, as a consequence of more advanced medical therapy and more
complicated surgical interventions in older and multimorbid patients, the number
of patients with ARF is increasing (1, 4, 5). Moreover, ARF itself increases the
risk to develop additional complications that can be deleterious. Recently, an
independent association between ARF and mortality has been shown in patients
following administration of radiocontrast media in an intensive care unit and in
patients following cardiac surgery (6, 7). Following radiocontrast media the
mortality of patients with ARF was increased five fold and following cardiac
surgery sixteen-fold as compared to patients with the same underlying disease
without ARF. The pathophysiology of ischemic ARF is reviewed with the emphasis on
the following mechanisms: Increased fractional excretion of sodium, Activation of
tubuloglomerular feedback, Cytoskeletal disruption, Tubular obstruction, Vascular
mechanisms. The following mediators will also be discussed: Calcium, Cysteine
proteases, Nitric oxide, Adhesion receptors and integrins.
PMID- 10688415
TI - Ischemic nephropathy.
AB - Ischemic nephropathy, involving stenotic lesions in the renal arteries,
associated with renal insufficiency, is now recognized as a frequent disease. It
may be responsible for a significant proportion of end stage renal disease, at
least in the Caucasian population. Some non-invasive but reliable techniques such
as echo-color-Doppler, gadolinium-enhanced magnetic resonance and spiral CT
angiography are now available for diagnosis. Revascularization with either
angioplasty, stent or surgery improves renal function in many patients. In the
near future systemic and/or local medical therapy will provide better answers for
renovascular disease.
PMID- 10688417
TI - Cytokine patterns and the effects of a preoperative steroid treatment in the
patients with abdominal aortic aneurysms.
AB - BACKGROUND: The aim of this study was to investigate the cytokine patterns of
patients with abdominal aortic aneurysms and the effects of preoperative steroid
administration on surgical stress. METHODS: From January 1996 to August 1996, 20
consecutive patients underwent an elective reconstruction of infrarenal abdominal
aortic aneurysms. The patients were randomly divided into two groups consisting
of a control group (n=10) and a steroid group (n=10), in whom 1 g of
methylprednisolone was intravenously administered two hours before the operation.
MEASURES: Interleukin-6 was serially measured and the perioperative parameters
including C-reactive protein were compared between both the control and the
steroid groups. RESULTS: The interleukin-6 values in the steroid group
immediately after declamping, as well as at one and three postoperative days were
significantly lower than those in the control group. C-reactive protein values at
one postoperative day in the steroid group were also significantly lower than
those in the control group. In one patient with a ruptured abdominal aortic
aneurysm, the interleukin-6 values were higher than those in the patients
undergoing elective surgery throughout the study. CONCLUSIONS: These results thus
suggest that preoperative steroid administration using methylprednisolone in
patients with abdominal aortic aneurysms appears to reduce surgical stress by
decreasing cytokine release.
PMID- 10688416
TI - Angiogenesis for the treatment of vascular diseases.
AB - Critical ischemia of the limbs or myocardium is frequently accompanied by diffuse
distal vascular disease making it unapproachable by conventional
revascularization techniques. Pharmacological treatment is available for coronary
artery disease but there has been no effective medical therapy for advanced
ischemia of the limbs. In the search for alternative treatments for patients with
diffuse distal disease, recent developments in vascular biology have directed
attention towards use of vascular growth factors. Therapeutic angiogenesis has
shown promising results in early clinical studies as shown by improved clinical
status and in some cases angiographic studies. We employed an angiogenic strategy
that utilizes enhanced vascular endothelial growth factor (VEGF) in a fibrin
network, in two patients with critical limb ischemia. Objectively, we were able
to demonstrate angiographically the growth of new blood vessels after
administration of VEGF and fibrin composite. Fibrin glue provides for the slow
release of and prolongs the availability of VEGF, thereby sustaining angiogenesis
resulting in improved oxygenation of ischemic tissue. Further investigations are
warranted to validate if angiogenesis may increase blood flow in patients with
advanced vascular disease.
PMID- 10688418
TI - Clinical laboratory monitoring of a synthetic antithrombin agent, argatroban,
using high performance liquid chromatography and functional methods.
AB - BACKGROUND: Argatroban is a peptidomimetic inhibitor of thrombin which is in
clinical trials for thrombotic complications. Clot-based assays measure the
cumulative anticoagulant effect of argatroban and its metabolites(s). To monitor
the absolute concentrations of argatroban, a specific HPLC method was developed.
METHODS: Validation studies included normal volunteers administered with
escalating doses of argatroban (ARG 102 Study), patients undergoing coronary
interventional procedures (ARG 310), and patients receiving argatroban in
conjuction with streptokinase for acute myocardial infarction (ARG 230). Plasma
samples were extracted with acetonitrile and reconstituted in a mobile phase. UV
detection was made at 333 nm. Calibratrion curves were prepared with known
standards of argatroban in normal human plasma. RESULTS: The retention time for
argaeroban was 6.0+/-0.5 min and the extraction efficiency was >98% (r2=0.99). In
the ARG102 Study, argatroban levels were: 0.84+/-0.23 (day 1), 1.55+/-0.34 (day
2), 2.92+/-0.15 (day 3), and 3.04+/-0.49 (day 4). In the ARG310 trial, the mean
argatroban levels were: 0.23+0.09 microg/ml (preinfusion), 5.77+/-0.92 microg/ml
(postinfusion/intraprocedure), and 2.23+/-0.29 microg/ml (postprocedure). In the
ARG 230 Study, the mean argatroban levels at 2-8 hrs were between 1.5-2.0
microg/ml. Upon completion of the infusion, a time-dependent clearance of
argatroban was noted. CONCLUSIONS: Since heparinization, hemodilution and
hypofibrinogenemia due to thrombolysis influence the clotting tests, absolute
quantitation of argatroban by HPLC in these patients provides a more reliable
means of monitoring this anticoagulant and helps in the dosage-optimization of
this agent. The current HPLC method is of value in the monitoring of patients who
are simultaneously administered with thrombolytic drugs.
PMID- 10688419
TI - Single lacunar brain infarction with transient signs versus those with long
lasting signs.
AB - BACKGROUND: In order to find out the difference between single brain lacunar
infarctions with transient signs and those with long-lasting signs, cerebral
blood flow studies and blood tests were performed. METHODS: Ten cases of single
lacunar infarction with transient signs and 10 of single lacunar infarction with
long-lasting signs were studied. Subcortical cystic infarctions with a diameter
of less than 1.5 cm were defined as lacunar infarction. Episodes lasting less
than 24 hours were classified as transient signs and those lasting 24 hours or
more as long-lasting signs. MEASUREMENTS: cerebral blood flows were measured
using the stable xenon computed tomography method. The regional cerebral blood
flows were measured before and 20 minutes after the intravenous injection of 17
mg/kg acetazolamide. Plasma fibrinopeptide A, platelet factor 4 and beta
thromboglobulin concentrations were determined at the Special Reference
Laboratories. RESULTS: Blood flows in the cerebral cortex and cerebral white
matter contralateral to the lacunar infarction were lower in the group with long
lasting signs than in that with transient signs. Cerebrovascular acetazolamide
reactivity in the cerebral cortex and white matter contralateral to the lacunar
infarction were lower in the group with long-lasting signs than in that with
transient signs. Plasma fibrinopeptide A, platelet factor 4 and beta
thromboglobulin concentrations were higher in the long-lasting signs group than
in that with transient signs. CONCLUSIONS: There may be some differences in
pathogenesis between single lacunar infarction with transient signs and those
with long-lasting signs.
PMID- 10688420
TI - Duplex screening as a method of quality assurance of perioperative
thromboembolism prophylaxis.
AB - BACKGROUND: Improvements in thrombosis prophylaxis in both the operative and non
operative fields aim to reduce further the not inconsiderable residual risk of
suffering a deep vein thrombosis or embolism. The goal of the study was to
establish the part played in a quality assurance strategy by early diagnosis of a
thrombosis and by knowledge of the hospital's internal patient-risk profile in
order to counter the unpredictability of thromboembolic complications and make
rational decisions about thromboembolism prophylaxis. METHODS: Duplex
ultrasonography has been used routinely in trauma surgical patients in Krefeld
Hospital since September 1991 as a screening method for diagnosing deep leg and
pelvic vein thrombosis prior to mobilisation of the patients. 778 patients were
investigated up to March 1997. In the period from September 1991 to September
1994, patients received standardised low-dose prophylaxis with unfractionated
heparin (UFH). In October 1994, the prophylaxis regimen was modified by changing
the anti-embolism stockings from bidirectional elastic stockings to transverse
elastic graduated compression stockings (TED) and by adapting the dosage of the
heparin prophylaxis to patient risk, with the use of low molecular weight heparin
(LMWH) Certoparin (Mono-Embolex NM) since April 1995. All patients with a deep
vein thrombosis were treated immediately with APTT-monitored full heparinisation
and immobilisation. RESULTS: In the period from September 1991 to March 1997, an
asymptomatic deep vein thrombosis of the lower limbs was diagnosed in 68 cases
(8.7%) out of 778 trauma surgical patients by means of routine duplex ultrasound.
Using a strategy of duplex screening and immediate
anticoagulation/immobilisation, no clinically significant pulmonary emboli
occurred in this period. At the same time, the antithrombotic efficacy of the
prophylaxis could be improved and assessed objectively by means of duplex
screening: with optimal compression stockings and consistent use of risk-adapted
UFH prophylaxis, it was possible to reduce the residual thrombosis rate, which
was 11.5% (95% CI 7.7-15.2%) with standard UFH prophylaxis, to 8.7 % (95% CI 4.5
12.9%) and ultimately, using the combination of optimal anti-embolism stockings
and LMWH prophylaxis, to 6.0% (95% CI 3.0-8.9%) which was significant (p<0.05).
The cost-effectiveness analysis resulted in a cost-relation per successfully
treated patient of about 1:100 for the diagnosis of a deep vein thrombosis using
duplex ultrasound and subsequent heparin treatment compared to the diagnosis and
intensive care treatment of a massive pulmonary embolism. CONCLUSIONS: Duplex
ultrasound screening for asymptomatic deep vein thrombosis thus proves to be a
suitable instrument for internal hospital quality control in thrombosis
prophylaxis. Its routine use can be recommended at least in high-risk patients,
not only from the medicolegal aspect but also from the purely economic aspect.
PMID- 10688421
TI - Inter-observer variation. An alternative method of assessing the role of
ultrasonic imaging in clinical decision-making in lower limb arterial disease.
AB - BACKGROUND: The aim of the study is to determine the role of duplex scanning in
deciding on the final treatment for patients with lower limb arterial disease
compared to intra-arterial digital subtraction arteriography (IA DSA). METHODS:
Eighty-two patients (55 males, 27 females, mean age 68 years) with lower limb
arterial disease had both duplex and arteriography performed. The findings of
both modalities were reported by sonographer and radiologist in 164 anonymous
reports. Five vascular surgeons (consultant grade) were asked to plan their
treatment on the data provided in these reports. For the purposes of statistical
analysis, the actual treatment the patient received was used as the reference
standard. Both reports and treatment decisions were coded (double blinded).
RESULTS: The overall accuracy of duplex scanning to assess arterial disease of
the lower limbs showed a sensitivity of 92%, and specificity of 99%. The accuracy
of the decisions based on duplex was 84% and kappa with k of 0.62 (95% CI+0.14)
compared to the reference standard, while the accuracy of the decision based on
arteriography was 85% and kappa 0.63 (95% CI+0.14). The accuracy of decisions
based on duplex compared to those based on arteriography (arteriography used as
reference standard) was 91% and a kappa of 0.77 (95% CI+0.14). CONCLUSIONS:
Duplex scanning is an accurate diagnostic modality, and clinical decisions can be
safely based on its findings.
PMID- 10688422
TI - Does in situ replacement of a staphylococcal infected vascular graft with a
rifampicin impregnated gelatin sealed Dacron graft reduce the incidence of
subsequent infection?
AB - BACKGROUND: The aim of this study was to treat methicillin-resistant
Staphylococcus aureus (MRSA) or S. epidermidis prosthetic vascular graft
infections by in situ replacement with a rifampicin bonded Gelsoft graft.
METHODS: Interposition grafts were placed in the internal carotid artery of 56
merino sheep and the graft surface directly inoculated with 10(8) colony forming
units (CFU) of MRSA (29) or S. epidermidis (27). At three weeks, grafts were
harvested and sheep allocated to three groups. In the MRSA infected group, sheep
received grafts soaked in 1.2 mg/ml (12), 10 mg/ml (10) and no (7) rifampicin.
For S. epidermidis, sheep received grafts soaked in 1.2 mg/ml (10), 10 mg/ml (9)
and no (8) rifampicin. There were two deaths, in the MRSA study group, one each
from the rifampicin treated groups. The remaining sheep were euthanased and
grafts harvested three weeks following regrafting. Grafts at harvests were
assessed for perigraft abscess formation, anastomotic disruption and graft
thrombosis. Swabs were taken to assess bacterial growth in the perigraft tissues,
and external and internal graft surfaces. A 3-5 mm segment of graft was incubated
in a broth medium. For S. epidermidis the remainder of the graft was ground and
then incubated in a broth medium. RESULTS: For MRSA, no statistical difference
between the groups was reached for any of the measured parameters. For S.
epidermidis, a significant reduction was reached for total infected specimens in
the 10 mg/ml group compared to both control (p<0.001) and 1.2 mg/ml (p<0.005)
groups. Graft reinfection was also less likely to occur with S. epidermidis than
MRSA. CONCLUSIONS: In conclusion, replacement of S. epidermidis infected vascular
grafts with 10 mg/ml rifampicin soaked Gelsoft graft is effective in reducing
subsequent S. epidermidis infection. This conclusion cannot be extended to MRSA
infected vascular grafts.
PMID- 10688423
TI - External support valvuloplasty in the treatment of chronic deep vein incompetence
of the legs.
AB - BACKGROUND: To evaluate the benefit from external support valvuloplasty in
chronic deep vein incompetence of the legs. METHODS: DESIGN: prospective study.
PATIENTS: twenty patients 7 primary and 13 secondary (post-thrombotic), with
severely symptomatic deep vein incompetence (DVI) of the legs. Preoperative
duplex sonography, videophlebography with ambulatory venous pressure measurement.
Surgical treatment with external support valvuloplasty with Venocuff (Vaso
Products Inc., Sommer-ville, NJ, USA). Postoperative clinical follow-up, duplex
and pressure measurements. RESULTS: In primary DVI, symptoms disappeared in all 7
patients, and in secondary DVI in 7 of 13 patients. All reconstructions were
competent in primary DVI and in 10 out of 13 in secondary DVI. The follow-up
period averaged 19 (6-32) months in primary DVI and 18 (5-31) months in secondary
DVI patients. CONCLUSIONS: In severely symptomatic deep vein incompetence of the
legs external support valvuloplasty is effective, especially in primary DVI. In
secondary DVI the competence of the reconstructions was 78% and the symptoms
disappeared in 52%. This means that external valvuloplasty is indicated even in
post-thrombotic patients.
PMID- 10688424
TI - Intramural hydatid cyst of the abdominal aorta.
AB - Intramural vascular hydatid disease is an extremely rare incidental finding. A
unique case of vascular wall hydatid cyst simulating aneurysmal dilatation of the
abdominal aorta is presented.
PMID- 10688425
TI - Inferior mesenteric artery aneurysm. Case report.
AB - This paper reports a large inferior mesenteric artery aneurysm discovered
incidentally during the work-up in a male patient with a thoracoabdominal aortic
aneurysm. Aortography disclosed an aneurysm in the inferior mesenteric artery
with a large marginal artery which filled the branches of the coeliac and
superior mesenteric arteries retrogradely. The thoracoabdominal aortic aneurysm
was reconstructed by a bifurcated aorto-biiliac Dacron graft while inferior
mesenteric artery revascularisation was achieved with a PTFE graft,
reconstruction being necessary because of its dominant blood supply to all of the
viscera. This case highlights the importance of aneurysmal reconstruction when an
anomalous arterial supply to the gastrointestinal tract from a dilated inferior
mesenteric artery has been demonstrated on a preoperative angiogram.
PMID- 10688426
TI - Primary aortoduodenal fistula treated successfully with surgery in a patient with
Takayasu's arteritis.
AB - Takayasu's arteritis was originally described as a systemic inflammatory arterial
disease presenting with occlusive changes. However, it has also been known to
cause aneurysm formation. In this report, a patient with Takayasu's arteritis was
found to have an aortoduodenal fistula. An emergency operation was carried out
with resection of the saccular aneurysm and the fistula. The aorta was
reconstructed with a prosthetic graft and the duodenum repaired. A pedicled
omental flap was placed between the aorta and the duodenum. The postoperative
recovery was uneventful, there was no evidence of persistent bleeding, and the
patient was well at the 3-year follow-up. This is the first case in the English
language literature of a primary aortoduodenal fistula treated successfully with
surgery in a patient with Takayasu's arteritis.
PMID- 10688428
TI - Ultraviolet radiation-induced tolerance.
PMID- 10688429
TI - Eosinophil activation by eotaxin--eotaxin primes the production of reactive
oxygen species from eosinophils.
AB - BACKGROUND: The CC chemokine eotaxin has been shown to possess selective
chemotactic activity for eosinophils, the major effector cells in allergic
inflammation. Reactive oxygen species (ROS) from eosinophils may damage cells or
tissue, such as the mucosal epithelium. In this study, we examined the effect of
eotaxin on ROS from eosinophils and compared its activity with RANTES and
interleukin (IL)-5. Moreover, we examined the signal transduction of eotaxin and
the effect of dexamethasone on ROS from eosinophils. METHODS: Eosinophils were
isolated by modified CD16-negative selection. ROS in luminol-dependent or
lucigenin-dependent chemiluminescence reaction were examined. Calcium ionophore
A23187 was added to the mixture of eosinophils with luminol or lucigenin, and
then ROS were determined. RESULTS: Eotaxin primed the production of ROS in a dose
dependent manner. ROS from untreated eosinophils evoked with calcium ionophore
A23187 in luminol-dependent chemiluminescence gave a maximal value of 4957+/-1035
intensity counts (IC) (mean+/-SE, n=7) and an integral value of 15.75+/-3.14 IC
(x10(-4)), while eosinophils that were treated with eotaxin gave maximal values
of 11 142+/-2300 IC (10 nM) and 29165+/-3718 IC (100 nM) and integral values of
41.07+5.44 IC (x10(-4)) (10 nM) and 152.90+/-22.38 IC (x10(-4))(100 nM).
Moreover, eotaxin was less effective as a priming agent with lucigenin-sensitive
pathways than luminol-sensitive pathways. Among several kinds of eosinophils
activating cytokines and chemokines, the priming effect of eotaxin on RO5 was the
most potent. Eotaxin-primed ROS were inhibited by pertussis toxin, which ADP
ribolysates G proteins; wortmannin, a phosphatidylinositol-3-kinase inhibitor;
and genistein, a tyrosine kinase inhibitor, suggesting the involvement of
pertussis toxin-sensitive G proteins, phosphatidylinositol-3-kinase, and tyrosine
kinase in the signal transduction of eotaxin. Moreover, dexamethasone inhibited
ROS from not only untreated eosinophils but also eosinophils treated with
eotaxin. CONCLUSION: Eotaxin may play an important role in the pathogenesis of
allergic inflammation through eosinophil activation by priming of eosinophil
oxidative metabolism, as well as by involvement in selective eosinophil
chemotaxis.
PMID- 10688430
TI - Allergy to date fruits: characterization of antigens and allergens of fruits of
the date palm (Phoenix dactylifera L.).
AB - BACKGROUND: Date-palm (Phoenix dactylifera L.) fruits are eaten daily by most
inhabitants of the Middle East and the neighboring countries. Recent reports have
indicated that dates are allergenic. This study aimed to investigate the
antigenic and allergenic potential of date fruits. METHODS: Date-fruit extracts
from eight cultivars were evaluated in skin prick tests (SPT) in an atopic
population, used to produce antisera, analyzed by SDS-PAGE, and fractionated by
gel-filtration chromatography. Sera from SPT-positive individuals were evaluated
by ELISA and RAST, and in anti-igE immunoblot experiments. RESULTS: About 13% of
patients were SPT-positive for at least two extracts. SDS-PAGE of whole extracts
revealed 15-18 protein bands of 6.5->100 kDa, and Sephacryl S-200 fractions gave
distinct peptide bands. RAST and anti-IgE ELISA gave a range of positive results,
which could be abrogated when sera were preabsorbed with fruit extracts. IgE
immunoblots of different extracts with pooled positive sera revealed different
anti-IgE-binding immunoprints. All the positive sera from fruit-allergic and
pollen-allergic individuals bound strongly to two anti-IgE reactive bands of 6.5
to 12-14 kDa and 28-33 kDa, respectively, and about 50% of sera bound to a 54-58
kDa band. CONCLUSIONS: These results strongly indicate that 1) date-palm fruit is
a potent allergen 2) sera from fruit-allergic as well as pollen-allergic patients
recognize common fruit-specific epitopes 3) there is heterogeneity in patient
responses to the different extracts.
PMID- 10688431
TI - Early increase in urinary leukotriene E4 (LTE4) is dependent on allergen dose
inhaled during bronchial challenge in asthmatic subjects.
AB - BACKGROUND: Urinary leukotriene E4 (LTE4) excretion is a good marker of the rate
of total body production of sulfidopeptide leukotrienes released during allergen
challenge. METHODS: Twenty-three subjects with allergic asthma were challenged
with inhaled allergen, and the urinary excretion of LTE4 was determined by
immunoenzymatic assay (associated with HPLC separation) at various intervals
after challenge. RESULTS: Allergen challenge caused an early airway response
(EAR) with a drop in FEV1 of 40.3+/-9.9%. This was associated with an increase in
urine LTE4 excretion for 0-3 h after allergen inhalation (296+/-225.25 pg/mg
creatinine) in comparison with baseline values obtained during the night before
challenge (101.02+/-61.97 pg/mg creatinine). Urinary LTE4 excretion was
significantly higher in subjects who inhaled a higher dose of allergen during
challenge (LTE4 during EAR: 211+/-192 pg/mg creatinine in subjects with inhaled
total dose of allergen <0.1 biologic units; 408+/-223 pg/mg creatinine in
subjects with inhaled total dose >0.1 biologic units). All subjects showed a late
airway response (LAR) to allergen of different severity, from mild (FEV1 fall: 15
20%) to severe (>30%); no correlation was found between the increase in urine
LTE4 excreted during LAR (3-7 h after challenge) and the severity of LAR, but
only subjects with severe LAR showed a significant increase in LTE4 during LAR in
comparison with baseline value. CONCLUSIONS: A release of sulfidopeptide
leukotrienes, as evaluated by urinary LTE4 excretion, can be documented during
EAR and LAR to allergen in relation to the dose of inhaled allergen, and it can
represent a useful index of the events underlying the airway inflammatory
responses during allergen challenge.
PMID- 10688432
TI - Overexpression of CD44 on alveolar eosinophils with high concentrations of
soluble CD44 in bronchoalveolar lavage fluid in patients with eosinophilic
pneumonia.
AB - BACKGROUND: High levels of interleukin-5 (IL-5) are found in the alveolar space
of patients with eosinophilic pneumonia (EP). IL-5 promotes the growth and
differentiation of eosinophils, as well as activating these cells. IL-5 also
induces the expression of CD44 on eosinophils in vitro. To evaluate the
contribution of CD44 to the pathogenesis of EP, we examined the expression of
CD44 on eosinophils in bronchoalveolar lavage fluid (BALF) and measured the
concentration of soluble CD44 (sCD44) in BALF from patients with EP. METHODS: The
concentrations of IL-5, sCD44, and hyaluronic acid (HA) were measured in BALF.
The expression levels of CD44 on eosinophils in BALF and peripheral blood in
patients with EP were compared. RESULTS: The expression of CD44 on alveolar
eosinophils and the concentration of sCD44 were increased in BALF of patients
with EP. There was a significant correlation between IL-5 and sCD44 in BALF. A
high concentration of HA was observed in BALF of EP patients. CONCLUSIONS: Our
results suggest that the high expression of CD44 on eosinophils probably results
from upregulation by IL-5 and could be important in the pathogenesis of EP.
PMID- 10688427
TI - Biologic functions of the IFN-gamma receptors.
AB - Interferon-gamma (IFN-gamma) is a cytokine that plays an important role in
inducing and modulating an array of immune responses. Cellular responses to IFN
gamma are mediated by its heterodimeric cell-surface receptor (IFN-gammaR), which
activates downstream signal transduction cascades, ultimately leading to the
regulation of gene expression. In order to study the role of IFN-gamma in a
number of immune responses and pathways, researchers have generated mice with
altered patterns of IFN-gammaR gene expression. These studies, together with
analyses of naturally occurring mutations of the IFN-gammaR in man, have been
instrumental in elucidating the diverse functions of IFN-gamma, and are the
subject of this review.
PMID- 10688433
TI - Regulation of ICAM-3 and other adhesion molecule expressions on eosinophils in
vitro. Effects of dexamethasone.
AB - BACKGROUND: ICAM-3 has been recently identified as the third leukocyte-function
associated-1 (LFA-1) ligand. ICAM-3 is expressed in eosinophils, but its
regulation has not been studied. The objective of this study was to investigate
the differential expression of ICAM-3 and other adhesion molecules (AM) on the
surface of eosinophils. We also evaluated the effects of dexamethasone on AM
expression. METHODS: Normodense eosinophils were isolated from peripheral blood
and incubated with calcium ionophore A23187 (calcimycin) with and without
dexamethasone. Expression of AM was assessed by flow cytometry and expressed as
fluorescence mean intensity (FMI). RESULTS: Peripheral blood eosinophils
constitutively expressed low levels of ICAM-1 and ICAM-2 (<10 FMI), moderate
levels (10-50 FMI) of CD29 and L-selectin, and high levels (>50 FMI) of ICAM-3,
LFA-1, and Mac-1. Calcium ionophore (1 microM) significantly increased Mac-1 and
ICAM-1 expression at 6 and 24 h. L-selectin expression decreased at 6 and 24 h,
but ICAM-2, ICAM-3, LFA-1, and CD29 expression did not show any significant
change after calcium ionophore stimulation. Dexamethasone decreased ICAM-3 and
increased L-selectin basal expression, and it caused a dose-related inhibition of
calcium ionophore-induced ICAM-1 expression. CONCLUSIONS: These findings suggest
that some AM, such as ICAM-1, Mac-1, and L-selectin, may be involved in adhesion
during eosinophil activation and that glucocorticoids may prevent airway
inflammation by regulating the expression of AM in eosinophils. The role of ICAM
3, a leukocyte AM highly expressed in resting eosinophils, remains to be
clarified.
PMID- 10688434
TI - Different serum soluble Fas levels in patients with allergic rhinitis and
bronchial asthma.
AB - BACKGROUND: The pathogeneses of allergic rhinitis and bronchial asthma are
believed to be closely mutually related because of the similar dynamics of
allergy-inducing cells and molecules and clinical overlap. In this study, we
compared these diseases in the dynamics of cell apoptosis-regulating molecules.
METHODS: Allergic rhinitis patients (n=36), bronchial asthma patients (n=22), and
healthy subjects (n=32) were subjected to measurement of serum (soluble Fas)
(sFas) levels during the stable and attack disease phases by a sandwich enzyme
linked immunosorbent assay. RESULTS: Serum sFas levels in patients with allergic
rhinitis during the attack phase were significantly lower (P<0.0001) than those
in healthy individuals. There were no differences between them during the attack
and stable disease phases. In contrast, serum sFas levels in patients with
bronchial asthma during the attack phase were higher (P<0.0005) than those in
healthy individuals. Interestingly, the levels during the attack phase were lower
(P<0.002) than those during the stable phase. CONCLUSIONS: Our results suggest a
different pathogenesis for allergic rhinitis and bronchial asthma at the cell
apoptosis-linked step.
PMID- 10688435
TI - Integrin expression on neutrophils and mononuclear cells in blood and induced
sputum in stable asthma.
AB - BACKGROUND: We speculated that the expression of integrins in the airway lumen of
asthmatic subjects might be altered compared with normal subjects during cell
recruitment from circulation. METHODS: To test this hypothesis, we investigated
the expression of integrin alpha-chains (CD11a, CD11b, and CD11c) in hypertonic
saline-induced sputum and peripheral blood leukocytes in mild to moderate stable
asthmatic and control subjects. Immunoreactivity for integrin alpha-chains was
assessed by immunocytology on cytospin preparations of sputum and blood. RESULTS:
In comparison of the percentages of CD11a+, CD11b+ and CD11c+ mononuclear cells
in sputum with their blood counterparts, no significant differences were observed
in control subjects, whereas CD11a and CD11b in asthmatic subjects were less
expressed on sputum cells. In both control and asthmatic subjects, sputum
neutrophils tended to decrease their expression of integrin alpha-chains compared
with circulating neutrophils. CONCLUSIONS: We showed that the sputum of
asthmatics, unlike normal subjects, is characterized by decreased expression of
integrins on mononuclear cells compared with their blood counterparts. The
results suggest that downregulation of integrins occurs in asthmatic airways
after cell recruitment from circulation.
PMID- 10688436
TI - Aeropollinic sampling at three different heights by personal volumetric collector
(Partrap FA 52).
AB - BACKGROUND: Aeropollinic sampling is usually performed by volumetric pollen traps
located on the top of buildings at a height of 15-20 m. The present study aimed
to determine whether pollen concentration is similar, at the same time, at
different heights. METHODS: Pollen concentrations were measured at the same time
for 3 days each month (March-October 1997), with three Partrap FA 52 devices
respectively located at 1.5, 5, and 15 m above the ground. A Burkard sampler was
used as control at the 15-m level. RESULTS: No significant difference in either
the total count or the single pollen counts was observed between the Partrap and
Burkard samplers at 15 m. The total pollen count did not differ significantly
between the Partrap at 1.5 m and 15 m (130+/-19 and 123+/-18, respectively),
whereas the sampler at 5 m collected an amount of pollen (84+/-14) significantly
lower than at 1.5 and 15 m (P<0.0001 and P<0.001, respectively). The amount of
Urticaceae pollen was significantly higher at 1.5 m (97+/-17) than at 15m (80+/
12) and 5m (58+/-11); P<0.02 and P<0.001, respectively. Regarding grass pollen,
the collector at 5 m captured significantly less pollen (4.5+/-0.8) than at 1.5m
(9.5+/-1.3) and 15m (7.2+/-1.3) (P=0.002 and P=0.02, respectively). No
significant difference was observed between the data obtained from samplers at
1.5 and 15 m. In addition, the Oleaceae, Cupressaceae, and Corylaceae pollen
counts were significantly higher when collected at 15 than at 5 and 1.5 m.
CONCLUSIONS: These data show that differences exist in pollen sampling performed
at different heights.
PMID- 10688437
TI - Allergic contact gingivostomatitis from a temporary crown made of methacrylates
and epoxy diacrylates.
AB - Occupational allergic contact dermatitis caused by (meth)acrylates is common in
dental personnel, whereas dental acrylic fillings and crowns have rarely been
reported to cause problems in dental patients. Here we report on a 48-year-old
woman who developed gingivitis, stomatitis, and perioral dermatitis after a
temporary crown made of restorative, two-component material had been inserted.
The manufacturer stated that the temporary crown base paste and catalyst
contained three (meth)acrylates, namely, a proacrylate, which is a modification
of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (BIS-GMA); a
tricyclate, which is a saturated, aliphatic, tricyclic methacrylate; and urethane
methacrylate. The manufacturer refused to give more exact information on the
(meth)acrylates. Patch testing revealed that the patient was highly allergic to
BIS-GMA, other epoxy diacrylates, and (meth)acrylates, as well as to the base
paste and catalyst of the temporary crown. Accordingly, it was concluded that the
allergic reaction was caused by BIS-GMA, or a cross-reacting (meth)acrylate, or
other (meth)acrylates in the temporary crown.
PMID- 10688438
TI - A case of allergy to cow's milk hydrolysate.
AB - We here report a girl, now 3 years old, who has suffered from severe food allergy
since her first year of life. She was strongly allergic to cow's milk, and had
high levels of IgE antibody (AB) to casein (210 kU/I), beta-lactoglobulin (43
kU/I), and alpha-lactalbumin (23 kU/l) at 12 months of age. In addition, at the
same age, she showed positive (2-4+) skin prick reactions to both unboiled and
boiled formulas (Profylac, Nutramigen, and Neocate), besides being positive in
RAST to Nutramigen (0.6 kU/l). During the first 3 years, IgE Ab levels against
casein and Nutramigen increased to 310 and 1.6 kU/l, respectively. Furthermore,
at 3 years of age, she had positive RAST to 14 of 15 tested food allergens, being
negative only to codfish. Assessment of eosinophil-related markers revealed high
total eosinophil count, increased eosinophil activity, and a low ratio of
interferon (IFN)-gamma:IL-5, indicating enhanced IL-5 production. The food
allergy was correlated to poor weight gain and increasing problems with atopic
allergy in the airways.
PMID- 10688439
TI - Circulating soluble L-selectin in atopic dermatitis.
PMID- 10688440
TI - Anticonvulsant hypersensitivity syndrome due to carbamazepine.
PMID- 10688441
TI - Anaphylaxis due to Monascus purpureus-fermented rice (red yeast rice).
PMID- 10688442
TI - Cross-reacting allergens in natural rubber latex and jelutong.
PMID- 10688443
TI - Sensitization to aeroallergens in Ankara, Turkey.
PMID- 10688444
TI - Occupational asthma to perfume.
PMID- 10688446
TI - Virus problems.
PMID- 10688445
TI - Unusual egg allergy in an adult.
PMID- 10688447
TI - Sparkling clean in Idaho.
PMID- 10688448
TI - Heating and pain sensation produced in human skin by millimeter waves: comparison
to a simple thermal model.
AB - Cutaneous thresholds for thermal pain were measured in 10 human subjects during 3
s exposures at 94 GHz continuous wave microwave energy at intensities up to
approximately 1.8 W cm(-2). During each exposure, the temperature increase at the
skin's surface was measured by infrared thermography. The mean (+/- s.e.m.)
baseline temperature of the skin was 34.0+/-0.2 degrees C. The threshold for
pricking pain was 43.9+/-0.7 degrees C, which corresponded to an increase in
surface temperature of approximately 9.9 degrees C (from 34.0 degrees C to 43.9
degrees C). The measured increases in surface temperature were in good agreement
with a simple thermal model that accounted for heat conduction and for the
penetration depth of the microwave energy into tissue. Taken together, these
results support the use of the model for predicting thresholds of thermal pain at
other millimeter wave (length) frequencies.
PMID- 10688449
TI - Models for retrospective quantification of indoor radon exposure in case-control
studies.
AB - In epidemiologic studies on lung cancer risk due to indoor radon the
quantification of individual radon exposure over a long time period is one of the
main issues. Therefore, radon measurements in one or more dwellings, which in
total have been inhabited by the participants for a sufficient time-period, are
necessary as well as consideration of changes of building characteristics and
ventilation habits, which influence radon concentration. Given data on 1-y alpha
track measurements and personal information from 6,000 participants of case
control studies in West and East Germany, an improved method is developed to
assess individual radon exposure histories. Times spent in different rooms of the
dwelling, which are known from a personal questionnaire, are taken into account.
The time spent outside the house (average fraction 45%) varies substantially
among the participants. Therefore, assuming a substantially lower radon exposure
outside the dwelling, the residence time constitutes an important aspect of total
radon exposure. By means of an analysis of variance, important determinants of
indoor radon are identified, namely constant conditions such as type of house
(one family house or multiple dwelling), type of construction (half-timbered,
massive construction, lightweight construction), year of construction, floor and
type of basement, and changeable conditions such as heating system, window
insulation, and airing habits. A correction of measurements in former dwellings
by factors derived from the analysis is applied if current living conditions
differ from those of the participants at the time when they were living in the
particular dwellings. In rare cases the adjustment for changes leads to a
correction of the measurements with a factor of about 1.4, but a reduction of 5%
on average only. Exposure assessment can be improved by considering time at home
and changes of building and ventilation conditions that affect radon
concentration. The major concern that changes in ventilation habits and building
conditions lead to substantial errors in exposure (and therefore risk) assessment
cannot be confirmed in the data analyzed.
PMID- 10688450
TI - Soil-to-plant transfer factors for radiocesium and radiostrontium in agricultural
systems.
AB - A database of soil-to-plant transfer factors for radiocesium and radiostrontium
has been compiled for arable crops from published and unpublished sources. The
database is more extensive than previous compilations of data published by the
International Union of Radioecologists, containing new information for
Scandinavia and Greece in particular. It also contains ancillary data on
important soil characteristics. The database is sub-divided into 28 soil-crop
combinations, covering four soil types and seven crop groups. Statistical
analyses showed that transfer factors for radiocesium could not generally be
predicted as a function of climatic region, type of experiment, age of
contamination, or soil characteristics. However, significant relationships
accounting for more than 30% of the variability in transfer factor were
identified between transfer factors for radiostrontium and soil pH/organic matter
status for a few soil-crop combinations. Best estimate transfer factors for
radiocesium and radiostrontium were calculated for 28 soil-crop combinations,
based on their geometric means: only the edible parts were considered. To predict
the likely value of future individual transfer factors, 95% confidence intervals
were also derived. A comparison of best estimate transfer factors derived in this
study with recommended values published by the International Union of
Radioecologists in 1989 and 1992 was made for comparable soil-crop groupings.
Whilst there were no significant differences between the best estimate values
derived in this study and the 1992 data, radiological assessments that still use
1989 data may be unnecessarily cautious.
PMID- 10688451
TI - A stochastic model of radiation-induced bone marrow damage.
AB - A stochastic model, based on consensus principles from radiation biology, is used
to estimate bone-marrow stem cell pool survival (CFU-S and stroma cells) after
irradiation. The dose response model consists of three coupled first order linear
differential equations which quantitatively describe time dependent cellular
damage, repair, and killing of red bone marrow cells. This system of differential
equations is solved analytically through the use of a matrix approach for
continuous and fractionated irradiations. The analytic solutions are confirmed
through the dynamical solution of the model equations using SIMULINK. Rate
coefficients describing the cellular processes of radiation damage and repair,
extrapolated to humans from animal data sets and adjusted for neutron-gamma mixed
fields, are employed in a SIMULINK analysis of criticality accidents. The results
show that, for the time structures which may occur in criticality accidents, cell
survival is established mainly by the average dose and dose rate.
PMID- 10688452
TI - Monte Carlo calculation of dose rate conversion factors for external exposure to
photon emitters in soil.
AB - The dose rate conversion factors D(CF) (absorbed dose rate in air per unit
activity per unit of soil mass, nGy h(-1) per Bq kg(-1)) are calculated 1 m above
ground for photon emitters of natural radionuclides uniformly distributed in the
soil. Three Monte Carlo codes are used: 1) The MCNP code of Los Alamos; 2) The
GEANT code of CERN; and 3) a Monte Carlo code developed in the Nuclear Technology
Laboratory of the Aristotle University of Thessaloniki. The accuracy of the Monte
Carlo results is tested by the comparison of the unscattered flux obtained by the
three Monte Carlo codes with an independent straightforward calculation. All
codes and particularly the MCNP calculate accurately the absorbed dose rate in
air due to the unscattered radiation. For the total radiation (unscattered plus
scattered) the D(CF) values calculated from the three codes are in very good
agreement between them. The comparison between these results and the results
deduced previously by other authors indicates a good agreement (less than 15% of
difference) for photon energies above 1,500 keV. Antithetically, the agreement is
not as good (difference of 20-30%) for the low energy photons.
PMID- 10688453
TI - Verification and modification of the ICRP-67 model for plutonium dose
calculation.
AB - On the basis of the available data and empirical expressions for the plutonium
excretion after injection, an age-related compartmental model has been developed.
It provides a better agreement with measured urinary excretion data than the
current ICRP 67 model. Moreover, the revised model avoids unphysiological
assumptions such as the transfer of activity from soft tissue to urinary bladder,
that were part of the ICRP model. The new predictions of the activity in feces
and in blood after an injection are closer to the available data than the ICRP 67
estimations and there is also a good agreement with the partitioning of plutonium
between skeleton and liver obtained from different autopsy studies. Furthermore,
the urinary excretion estimated by the improved model has been checked using some
data from occupationally exposed individuals. As the plutonium uptake in these
workers occurred by inhalation, the improved model and the ICRP 67 model were
compared by connecting them to the ICRP 66 respiratory tract model. The improved
model consistently yields a better agreement with the measured excretion and
higher estimations of intake than the ICRP 67 model.
PMID- 10688454
TI - Gamma radiography with 75Se sources: consequences of a violent fire.
AB - Due to the volatile nature of selenium and selenium dioxide, an important
atmospheric dispersion of 75Se can occur in case of a violent fire (>800 degrees
C). This type of accident is possible when transporting or using a highly active
75Se source for gamma radiography. The consequences of this dispersion are
analyzed. From the point of view of radiological protection, it can be concluded
that in radiography the unprotected 75Se sealed sources have to resist for 1 h to
a temperature of 1,200 degrees C. If this is not the case, x-ray equipment and
192Ir sources have to be preferred above 75Se sources.
PMID- 10688455
TI - Comparison of two dose-area-product ionization chambers with different conductive
surface coating for over-table and under-table tube configurations.
AB - A custom-built graphite-coated transmission ionization chamber is compared to the
VacuDAP 2001 (VacuTec, Dresden, Germany), which has transparent conductive
electrodes. A study was made of the dependence of response on x-ray tube
potential for both types of chamber under identical conditions of exposure using
over-table and under-table x-ray tubes. Since the calibration factor is the dose
area product of the radiation incident on the patient per chamber reading, it
depends on the intrinsic response of the chamber as well as the effect of
material in the beam between the x-ray tube and patient. Differences of about 20%
were measured between the intrinsic and the over-table calibration factors and
between the over-table and the under-table calibration factors for both chambers.
The VacuDAP display is specifically calibrated for the over-table condition and
would overstate the actual DAP in the under-table case. The intrinsic response of
the graphite chamber is nearly independent of tube potential. Although the
variation of response with tube potential of the graphite chamber is increased
when it is used as an over-table and an under-table patient monitor, it shows
less overall variation of response than the VacuDAP. The average deviation of
each calibration factor from the mean is less than 5% over the range of 40 to 140
kVp for both chambers.
PMID- 10688456
TI - Applications of a quadratic variance model for counting data.
AB - A quadratic variance model expressed as a function of sample mean is used to
describe counting variance for a mechanical system that exhibits extra-Poisson
variance. The nonlinear term describes the extra-Poisson variance, and the linear
terms describe the intrinsic and propagated Poisson variance. The quadratic
variance model also is applied to repetitive bioassay data, where the nonlinear
term describes the well-known phenomenon of biological variance, which is a
special case of extra-Poisson variance. The model was found to be suitable for
the bioassay data as well. Detection limits for extra-Poisson variance are
discussed, as well as the estimation of net signal detection limits, intake, and
committed effective dose equivalent using the quadratic variance model.
PMID- 10688457
TI - Non-invasive measurement of water content in a lung phantom by neutrons.
AB - A novel, non-invasive technique for measuring water content in lungs is
described. This technique could find important medical applications such as real
time monitoring of lung edema development in patients affected by cardiac
insufficiency undergoing physical effort. The technique is based on the
moderation (speed decrease) of fast neutrons crossing the lungs, due mostly to
the water contained in lungs. In the application of this diagnostic method, the
necessary dose given to the patient is lower than that associated with lung
imaging techniques that do not use an image intensifier. The results so far
obtained are encouraging, and the method appears to be an improvement over those
so far reported in literature as it is able to detect a lung water increase
equivalent to 25% of a full edema with a 20% standard error. Research is being
performed in order to refine the technique, investigate geometry effects and make
the method suitable to the medical field.
PMID- 10688458
TI - A method for determining leakage of 133Xe gas from septum-sealed glass vials.
AB - We have developed a method for determining the leakage of 133Xe gas from septum
sealed glass vials that are supplied for medical examinations. Twenty vials each
originally containing 370 MBq of 133Xe and 20 vials each originally containing
740 MBq 133Xe were measured daily for 26 d. Retention of 133Xe within the vial
was modeled as a first order process with a constant rate coefficient, lambdaT.
The value of lambdaT was estimated for each vial using a regression analysis. The
leakage rate, lambdaL, was then determined assuming that lambdaT = lambdaL +
lambda(r) where lambda(r) represents the physical decay of 133Xe. Monte Carlo
simulations were performed using uncertainties in the estimates of each vial to
obtain the mean and tails of the distribution for the average leakage rate,
lambdaL. The average leakage rate for the complete sample of vials was 0.00007 d(
1) with an upper, one-sided, 95% confidence limit of 0.0011 d(-1). Uncertainties
in the published values of lambda(r) for 133Xe made a significant contribution to
the uncertainties of the leakage rate for this sample of vials. The methods
described can be applied to other situations where leakage of radioactive
materials may be of concern.
PMID- 10688459
TI - Radiation safety program outcomes as indicated by regulatory compliance
activities from 1988 to 1997 in Texas.
AB - Occupational radiation protection programs rarely encounter readily observable
workplace injuries or illnesses, so upper management must rely on different
indicators of relative performance. In many cases, the number of violations,
complaints, and reported incidents is used. As with reported workplace injury and
illness data, violation, complaint, and incident data provide only a crude
indication of a radiation protection program's overall effectiveness. Even so, it
is important to recognize that tangible program outcome measures such as these
often dictate management decisions. Hence, safety professionals should have
access to baseline violation, complaint, and incident trend data so that more
informed preventive strategies can be put into place where possible. To assess
the outcomes of radiation protection programs in Texas, data from regulatory
compliance activities for a 10-y period, inclusive of calendar years 1988 to
1997, were assembled, summarized, and independently verified. For licensees of
radioactive material, the ten most frequently cited violations represented 64% of
the total issued during the study period. For registrants of radiation producing
devices, the ten most frequently cited violations accounted for 73% of the total.
A particular emphasis on proper recordkeeping is evident, and should be noted by
any internal radiation protection quality assurance programs. Regardless of the
permit type, the vast majority of violations issued were classified as low
severity. Licensees were found to be involved in approximately 73% of the
incidents recorded, with overexposures and badge overexposures representing the
largest identifiable types. Registrants were found to be involved in
approximately 57% of the complaints recorded, with the largest identifiable issue
being concerns about health care provider qualifications or performance. Although
this study was limited to a single state, the results can be of benefit to both
quality assurance programs and professional health physics training courses by
objectively identifying the areas commonly found to be deficient.
PMID- 10688460
TI - Technology-based distance education and the absence of physical presence.
PMID- 10688461
TI - Kansas City Colleagues in Caring: giving new meaning to networking.
PMID- 10688462
TI - LPN to RN articulation: a collaborative solution.
PMID- 10688463
TI - A framework for assessing outcomes and practices in Web-based courses in nursing.
AB - This article presents a framework to assess the dynamic interaction of technology
used to offer Web-based courses, the teaching-learning practices in these
courses, and the outcomes enabled by the technology. Concepts of the model
include outcomes, educational practices, faculty support, learner support, and
use of technology. Variables are identified for each of the concepts.
PMID- 10688464
TI - Insights learned from teaching pathophysiology on the World Wide Web.
AB - This article describes a one-credit, graduate level pathophysiology module taught
using the World Wide Web. Student outcomes are compared to those of students who
took the same module in a traditional classroom setting. Although the majority of
the graduate students were not Web literate, they became more comfortable with
this instructional medium over time. A comparison of the Web-based instruction
with the traditional format, both directed by the same instructor, showed no
significant differences in student performance on a multiple choice examination.
PMID- 10688465
TI - Teaching using interactive video: creating connections.
AB - This article addresses the two essential elements of distance learning: the
technology and the pedagogy. Both areas are discussed through the four components
-information, support, resources, and relationships--of a work effectiveness
model. Drawing from recent literature and their experience, the authors offer
strategies for making interactive video technology "invisible" while engaging
students at a distance. Students experience connections when faculty know how to
manage the equipment, plan ahead, and consciously construct strategies for
creating relationships across the miles.
PMID- 10688466
TI - Graduate education in nursing leadership through distance technologies: the
Canada-Norway Nursing Connection.
AB - The Canada-Norway Nursing Connection was a collaborative project designed to
provide an international educational experience for graduate students in nursing
via distance technology. Computer-conferencing and video-teleconferencing were
used to address nursing leadership content through case studies. The same
technologies were employed to develop the project. The processes of planning and
implementing the international linkage are described. Agreement about goals,
content, context for online discussion, delivery methods, academic expectations,
language support, and logistics was essential. The media proved to be effective
for students to gain understandings about nursing leadership, health care, and
the forces influencing the nursing profession globally. Insights from the project
provided a basis for the development of a model for interactive, international
graduate education that will be of value to educators dedicated to helping
students gain a global understanding of nursing and health care issues.
PMID- 10688467
TI - Lessons learned: using asynchronous computer-mediated conferencing to facilitate
group discussion.
PMID- 10688468
TI - A pilot study to investigate the impact of interactional television on student
evaluation of faculty effectiveness.
AB - While the dominant theme of distance education research has been the learner,
learner achievement is not necessarily the only important consideration in
assessing the effectiveness of ITV programs. With nearly half of the nursing
programs recently surveyed by Reinert and Fryback (1997) offering or planning to
offer distance learning in the near future, researchers and developers must seek
to understand the impact of ITV on the teacher. These programs require faculty
who are committed and prepared to teach outside of the traditional classroom.
Selection of faculty requires attention to appropriate qualifications and
knowledge of strategies to bridge teacher-learner separation created by distance
education. Faculty, peers, and administrators should consider the teaching
environment when interpreting data designed to evaluate teacher effectiveness of
ITV teaching.
PMID- 10688469
TI - Evaluating electronic information strategies in a master of science in nursing
and master in health services administration interdisciplinary learning
experience.
PMID- 10688470
TI - Head restraints--the neglected countermeasure.
AB - In a rear-end crash, if an occupant's head is unsupported it lags behind as the
torso is accelerated forward. This causes the neck to change shape, first taking
an s-shape and then bending backward in a 'whiplash' motion. This sudden
differential movement of the head and torso can cause 'whiplash' injuries to the
neck. This paper reviews methods to minimize the differential head/torso movement
and reduce the resulting injuries, focusing on the necessary first step for
prevention, which is a head restraint that is behind and close to the back of an
occupant's head during the crash. The history of head restraints since the 1950s
is reviewed, with particular attention to advanced restraint designs that are
proving effective in reducing whiplash injury risk in dynamic tests using a new
crash test dummy neck and a new neck injury criterion.
PMID- 10688471
TI - Is a lifetime history of neck injury in a traffic collision associated with
prevalent neck pain, headache and depressive symptomatology?
AB - The objective of this study is to determine whether independent associations
exist between a history of neck injury related to a motor vehicle collision and:
(1) graded neck pain in the past 6 months; (2) headaches in the past 6 months
and; (3) depressive symptomatology during the past week. We used data from the
Saskatchewan Health and Back Pain Survey, a population-based cross-sectional
survey mailed to a stratified random sample of 2184 Saskatchewan adults aged 20
69 years. Fifty-five percent of the eligible population participated. The
exposure was collected by asking subjects whether they had ever injured their
neck in a motor vehicle collision. The outcomes: 6-month prevalence of graded
neck pain, 6-month prevalence headache and depressive symptomatology during the
past week were measured with valid and reliable questionnaires. Sixteen percent
of the study sample reported a lifetime history of neck injury in a traffic
collision. The association between neck injury and the outcomes was determined
from polytomous and binary multivariate logistic regression with adjustment for
age, gender and other covariates. A history of neck injury was positively
associated with low intensity/low disability neck pain (OR = 2.81; 95% CI 1.81
4.37), positively associated with high intensity/low disability neck pain (OR =
4.46; 95% CI 2.49-4.99) and with disabling neck pain (OR = 3.30; 95% CI 1.48
7.39). Similarly, we found a positive association between a history of neck
injury in a motor vehicle collision and headaches that moderately/severely impact
on one's health (OR = 2.09; 95% CI 1.27-3.44). No association was found between
neck injury and depressive symptomatology (OR = 0.84; 95% CI 0.50-1.40). Our
cross-sectional analysis suggests that neck pain and severe headaches are more
prevalent in individuals with a history of neck injury from a car collision.
However, the results should not be used to infer a causal relationship between
whiplash and chronic neck pain and headaches.
PMID- 10688472
TI - Biomechanical assessment of soft tissue cervical spine disorders and expert
opinion in low speed collisions.
AB - The multidisciplinary research of injury mechanisms and injury prevention
requires the assessment of the technical and biomechanical circumstances of a
collision; moreover, the causality assessment in the individual cases is
facilitated by taking these aspects into account. In fact, only specially trained
engineers and biomechanical experts are in a position to evaluate these relevant
basic facts. In many crucial court cases, important technical factors such as
collision angle, structural stiffness, extent of intrusion and the vehicle's
velocity change are often ignored. The purely medical causality assessment is
often based only on a coincidence of time of the 'accident' and the onset of the
disorders. Unfortunately, statements about the 'accident speed' or the nebulous
'accident energy' are often made by clinicians with neither a proper collision
documentation nor the necessary biomechanical and technical background. In order
to overcome shortcomings of injury causality assessment as well as the
terminology associated with soft tissue cervical spine injuries, a subdivision of
the term 'accident severity' into four classes is proposed. Consequently, an
'accident severity assessment' can only be performed by a collaboration of four
corresponding classes of experts, i.e. the engineer (dynamic loading of the
vehicle), the biomechanical expert (biomechanical loading of the occupant), the
physician (clinically diagnosable injuries), and eventually the psychiatrist
(subjective sequelae individually experienced by the victim).
PMID- 10688473
TI - Neck injuries in car collisions--a review covering a possible injury mechanism
and the development of a new rear-impact dummy.
AB - A review of a few Swedish research projects on soft tissue neck injuries in car
collisions is presented together with some new results. Efforts to determine neck
injury mechanisms was based on a hypothesis stating that injuries to the nerve
root region in the cervical spine are a result of transient pressure gradients in
the spinal canal during rapid neck bending. In experimental neck trauma research
on animals, pressure gradients were observed and indications of nerve cell
membrane dysfunction were found in the cervical spinal ganglia. The experiments
covered neck extension, flexion and lateral bending. A theoretical model in which
fluid flow was predicted to cause the transient pressure gradients was developed
and a neck injury criterion based on Navier-Stokes Equations was applied on the
flow model. The theory behind the Neck Injury Criterion indicates that the neck
injury occurs early on in the rearward motion of the head relative to the torso
in a rear-end collision. Thus the relative horizontal acceleration and velocity
between the head and the torso should be restricted during the early head-neck
motion to avoid neck injury. A Bio-fidelic Rear Impact Dummy (BioRID) was
developed in several steps and validated against volunteer test results. The new
dummy was partly based on the Hybrid III dummy. It had a new articulated spine
with curvature and range of motion resembling that of a human being. A new crash
dummy and a neck injury criterion will be very important components in a future
rear-impact crash test procedure.
PMID- 10688474
TI - Whiplash injury--are current head restraints doing their job?
AB - It is generally accepted that the incidence of whiplash associated disorders is
increasing in all industrialised countries, despite the almost universal fitment
of head restraints in at least the front seats of cars. This is usually
attributed to the fact that few people can be observed to follow the standard
recommendations as regards head restraint positioning, that is, level with the
head vertically and as close to the head as possible horizontally. This study set
out to determine whether any other factors, in addition to head restraint
adjustment, could be found which would influence the severity of whiplash injury.
This was done by linking medical assessment of real-world accident victims with
engineering assessment of the accident vehicles. A random sample of road accident
victims suffering from whiplash associated disorder was studied. The vehicles
they had been travelling in were examined to assess impact severity and, where
possible, measurements were made of seat and head restraint adjustment with the
subject sitting in the vehicle. All subjects were interviewed to assess the
disability resulting from their injuries, and their progress was followed for 12
months. The results were subjected to statistical analysis to try to determine
relationships between severity of injury (as measured by resultant disability)
and a number of occupant- and vehicle-related factors. A significant proportion
of the sample had suffered lumbar strain injury in addition to whiplash, and
these were excluded from the present analysis. Frontal impact victims suffered
symptoms indistinguishable from those of rear impact victims. The beneficial
effects of good head restraint adjustment could not be clearly demonstrated, and
some trends, especially in rear impacts, where the benefits of a well-adjusted
restraint should have been very clear, indicated that larger distances from head
to restraint were associated with lower disability. The paper discusses these
counter-intuitive results and their implications.
PMID- 10688475
TI - How crash severity in rear impacts influences short- and long-term consequences
to the neck.
AB - The main public-health problem concerning WAD are injuries leading to long-term
consequences. Yet epidemiological studies mostly concentrate on data based on the
injury outcome occurring shortly after the crash. The purpose of this article is
to study the influence of crash severity in rear impacts leading to short and
long-term consequences to the neck (WAD 1-3), lasting less than or more than 1
year. The influence of change of velocity as well as the car acceleration were
investigated by using data from crash pulse recorders (CPR) installed in
vehicles, involved in rear impacts. The influence of the car acceleration were
also investigated by studying the frequency of occurrence of a tow-bar (hinge) on
the struck car. Apart from real-life data, full-scale car-to-car crashes were
performed to evaluate the influence of a tow-bar on the struck car. The crash
tests showed that a tow-bar may significantly affect the acceleration of the car
as well as that of the occupant. According to real-life crashes, a tow-bar on the
struck car increased the risk of long-term consequences by 22% but did not affect
the risk of short-term consequences. Out of the 28 crash recorder-equipped struck
cars involving 38 occupants, 15 sustained no injury where the peak acceleration
was 6g or less, 20 sustained short-term consequences where the peak acceleration
was 10g or less. Three occupants from two different crashes sustained long-term
consequences. The two crashes which resulted in long-term disabling neck injuries
had the highest peak acceleration (15 and 13 x g), but not the highest change of
velocity.
PMID- 10688476
TI - Neck injuries in frontal impacts: influence of crash pulse characteristics on
injury risk.
AB - AIS1 neck injuries are the most frequent disabling injuries among car occupants
in road traffic accidents. Although neck injury is mostly regarded as resulting
from rear end collisions, almost one third of all neck injuries occur in frontal
impacts. The injury mechanisms in both rear-end and frontal impacts are still not
known, although different hypotheses exist. Since 1992, approx. 100,000 vehicles
on the Swedish market have been equipped with crash recorders to measuring
frontal impacts. This paper analyses the influence of different characteristics
derived from the acceleration time history on the risk of short- and long-term
disability to the neck in frontal impacts. The study includes injury outcomes
from 187 restrained front seat occupants in 143 frontal collisions with an
overlap exceeding 25%, where the crash pulses have been recorded using crash
pulse recorders. The results show that the shape of the crash pulse influences
the risk of long-term disability to the neck. The vehicle accelerations in the
mid and last third of the crash pulse seem to be important. It is also shown how
change of velocity and mean and peak accelerations influence the neck-injury
risk. It is suggested that the risk of sustaining an AIS1 neck injury in frontal
impacts could be reduced by using more effective pretensioners and more advanced
belt-load limiters. These results may also have implications for neck injury
mechanisms in rear-end impacts.
PMID- 10688477
TI - The relationship between clinical and kinematic responses from human subject
testing in rear-end automobile collisions.
AB - Recent experiments have produced a linked data set of clinical and kinematic
responses for human subjects exposed to controlled low-speed rear-end collisions.
The purpose of this paper was to examine this paired data set and determine
whether the presence or absence of clinical symptoms could be predicted from the
peak linear and angular kinematic response of the head and neck. The data were
generated using 42 male and female human subjects seated normally in the front
passenger seat of a stationary vehicle struck from behind to produce vehicle
speed changes of 4 and 8 km/h. Pre- and post-test clinical examinations
documented the presence, severity and duration of whiplash-associated disorders
(WAD). Logistic regression and backward elimination of independent variables were
used to develop the prediction model. The analysis yielded a 16 parameter model
that was significantly related (odds ratio = 21.2; P = 0.0069) to the presence or
absence of transient whiplash symptoms. The model correctly predicted symptom
presence in 13 of 23 tests (sensitivity 57%) and symptom absence in 49 of 52
tests (specificity 94%) in a population of 75 with a symptom prevalence of 31%.
The model's positive predictive value was 81% and its negative predictive value
was 83%. Despite statistical significance, the model did not discriminate between
the presence and absence of symptoms in all tests, and indicated that factors
other than the selected peak kinematic responses influenced symptom production.
PMID- 10688478
TI - Seat back and head restraint response during low-speed rear-end automobile
collisions.
AB - Automobile seat backs and head restraints play a key safety role during low-speed
rear-end collisions, yet few studies have explored the effect of collision
variables on seat response. In this study, the effects of vehicle speed change
and seat belt use on dynamic seat back and head restraint response during low
speed rear-end automobile collisions were examined. Four human subjects were
repeatedly exposed to vehicle-to-vehicle rear-end collisions with speed changes
of 2, 4, 6 and 8 km/h. Seat back force and deflection, and head restraint force
were measured. The point of application of the resultant force applied to the
seat back and head restraint were determined. The magnitude and time of peak
kinematic and kinetic response parameters were used in a two-way repeated
measures analysis of variance (ANOVA) for speed change and seat belt use. The
results showed that 20 of the 24 seat back and head restraint response parameters
varied with speed change and none of the parameters varied with seat belt use.
Head restraint forces, seat back forces and seat back deflections increased
approximately linearly with speed change, whereas time to peak response,
direction and moment arm of the forces remained either constant or varied only
slightly over the range of speed changes tested.
PMID- 10688479
TI - Role of awareness in head-neck acceleration in low velocity rear-end impacts.
AB - Fourteen normal healthy seated and restrained young adults were delivered rear
end impacts of four intensities of acceleration. The chair was delivered a
regulated and controlled pneumatic blow using a 30 cm cylinder to cause an
acceleration of 0.5, 0.9, 1.1 and 1.4g. The accelerated chair was stopped
suddenly by impacting the stopper at the other end of the 2 m long friction
reduced track. In one set of trials, subjects were informed about the impending
impact and in the other they were blindfolded and provided with loud auditory
input to eliminate cues of the impact. The accelerations of the chair, shoulder
and head of the participating subjects were measured triaxially and compared
between levels of acceleration and expectation. The multiple analyses of variance
revealed that the peak acceleration was significantly affected by the gender (P <
0.01), intensity of impact (P < 0.001), and expectation (P < 0.0001). The
accelerations were significantly different in different axes (P < 0.001). A
significant two-way interaction between acceleration and expectation (P < 0.03),
and expectation and axes of acceleration (P < 0.02) would imply that awareness of
the impending impact serves to significantly reduce the level of accelerations of
head and neck.
PMID- 10688480
TI - Influence of seat characteristics on occupant motion in low-speed rear impacts.
AB - To analyze the effect of the seat characteristics on dummy motions and human
volunteer motions, sled tests simulating low-speed rear impacts were conducted
with some seats which had different characteristics. Volunteer's cervical
vertebral motions were photographed with an X-ray cineradiographic system at a
speed of 90 frames/s as well as the visible motions of dummy's and volunteer's
were recorded. Although the tests were conducted under limited conditions, the
results indicated the relationship between the occupant's visible motions, which
are assumed to be closely related to the whiplash injury mechanism, and seat
characteristics. It should be noted that the volunteer sled tests were discussed
and approved by the Tsukuba University Ethics Committee and the volunteer
submitted his informed consent in writing in line with the Helsinki Declaration.
PMID- 10688481
TI - Pressure measurements in the spinal canal of post-mortem human subjects during
rear-end impact and correlation of results to the neck injury criterion.
AB - The aim of this study is to validate the pressure effect theory on human beings
during a realistic rear-end impact and to correlate the neck injury criterion to
pressure in the spinal canal. Sled experiments were performed using a test setup
similar to real rear-end collisions. Test conditions were chosen based on
accident statistics and recordings of real accidents. In particular, velocity
change and acceleration level were reproduced similar to actual collisions. The
head restraint as well as the seat back were adjusted to different positions. Two
small pressure transducer were implemented to the spinal canal of postmortem
human subjects and pressure measurement similar to the pig experiments (using
exactly the same equipment) were performed. A total set of 21 experiments with
four different subjects were performed. The subjects were additionally
instrumented with triaxial accelerometers that allowed for calculation of the NIC
criterion. Results showed that NIC and pressure amplitudes of the CSF correlate
well and therefore NIC seems to be able to predict these amplitudes also for
human beings. Conclusions whether these pressure effects induce soft tissue neck
injuries or not could not be drawn and should be investigated in further
research.
PMID- 10688482
TI - A new mathematical neck model for a low-velocity rear-end impact dummy:
evaluation of components influencing head kinematics.
AB - A mathematical model of a new rear-end impact dummy neck was implemented using
MADYMO. The main goal was to design a model with a human-like response of the
first extension motion in the crash event. The new dummy neck was modelled as a
series of rigid bodies (representing the seven cervical vertebrae and the
uppermost thoracic element, T1) connected by pin joints, and supplemented by two
muscle substitutes. The joints had non-linear stiffness characteristics and the
muscle elements possessed both elastic stiffness and damping properties. The new
model was compared with two neck models with the same number of vertebrae, but
without muscle substitutes. The properties of the muscle substitutes and the need
of these were evaluated by using three different modified neck models. The motion
of T1 in the simulations was prescribed using displacement data obtained from
volunteer tests. In a sensitivity analysis of the mathematical model the
influence of different factors on the head-neck kinematics was evaluated. The
neck model was validated against kinematics data from volunteer tests: linear
displacement, angular displacement, and acceleration of the head relative to the
upper torso at 7 km/h velocity change. The response of the new model was within
the corridor of the volunteer tests for the main part of the time history plot.
This study showed that a combination of elastic stiffness and damping in the
muscle substitutes, together with a non-linear joint stiffness, resulted in a
head-neck response similar to human volunteers, and superior to that of other
tested neck models.
PMID- 10688483
TI - Road safety engineering: an effective tool in the fight against whiplash
injuries.
AB - Road safety engineering can play an integral part in the prevention of whiplash
injuries. While improvements to vehicle design can reduce the severity of
whiplash injuries when a crash occurs, improvements to road safety can prevent
whiplash-inducing crashes from occurring in the first place. Whiplash injuries
are most commonly associated with rear end crashes. Unfortunately, rear end
crashes are also the most common type of crash at urban signalized intersections,
where the majority of crashes occur in British Columbia, Canada. The Insurance
Corporation of British Columbia (ICBC), through the road improvement program, has
been funding road improvements in order to reduce the frequency of collisions at
high crash locations in British Columbia. Several road safety engineering
countermeasures specifically targeted at rear end collisions have been researched
and deployed. These countermeasures include simple and affordable solutions such
as signal visibility enhancements, as well as complex and expensive solutions
such as intersection geometric upgrades. When appropriately used, these
countermeasures have proven to be extremely cost-effective in reducing the
frequency of rear end collisions. Widespread application of signal visibility
enhancements is now being pursued to further decrease the risk of rear end
collisions and whiplash injuries. Costs are the direct cost of the ICBC portion
of the investment and benefits are only those associated with reduced insurance
claims over a 2-year period.
PMID- 10688484
TI - Injury surveillance in Victoria, Australia: developing comprehensive injury
incidence estimates.
AB - This study aimed to develop an estimate of the incidence of all medically-treated
injury by level of severity and to broadly describe the epidemiology of injury in
the Australian State of Victoria in a given year. Victoria has developed a
relatively comprehensive injury surveillance system. Data is currently collected
by various agencies on injury deaths, hospitalisations and emergency department
attendances. The method used to establish the incidence of both unintentional and
intentional injury is described. Incidence figures were directly derived, or
estimated from, the available Victorian health sector and Coronial data bases for
three level of severity (deaths, hospitalisations and medical treatment only) and
for causes of injury, age and gender groups, location of the injury event and
activity at the time of injury. In 1993/1994, injuries resulted in at least 1487
deaths, 67,402 persons hospitalised and an estimated 397,160 medically-treated,
non-hospitalised injured persons in Victoria. In total, over 466,000 people were
injured or 10.5 persons per year for every 100 residents. Males sustain 62% of
all injuries yet represent 49.5% of the population. Almost three-quarters of
injury fatalities and over 60% of non-fatal injuries occur among males. Young
people aged 15-24 years account for 22% of all injuries yet represent only about
16% of the Victorian population. Children (0-14 years) also suffer relatively
high injury rates, although mainly less severe, while the elderly are at risk of
more severe injuries. The leading cause of injury death in Victoria is suicide,
followed by motor vehicle accidents, whereas falls are the leading cause of all
non-fatal injury. Most injuries occur in the home (36%), areas of sport and
recreation (12.5%) and transport (11.7%). They are mainly associated with leisure
activities (33.1%), work (11%) and transportation (10.8%). This study
demonstrates a method for the development of comprehensive injury incidence
estimates. The results indicate that injuries have a significant impact on the
Victorian community, health care system and economy in general. Reliable
incidence data are necessary for descriptive epidemiology and provide the basis
for quality of life and economic cost studies. Together this information has
potential application for evidence-based strategic planning and evaluation in
injury research and prevention.
PMID- 10688485
TI - Neck pain and head restraint position relative to the driver's head in rear-end
collisions.
AB - This two-year investigation was designed to estimate the incidence of driver neck
pain in rear-struck vehicles involved in two-vehicle collisions and to determine
the relationship between neck pain and specific vehicle, human, and environmental
factors. Neck pain percentages were significantly higher for female (45%) than
for male (28%) drivers. For female and male drivers, neck pain likelihood
increased as head restraint height decreased below the head's center of gravity,
although this effect was significant only for females. Head restraint backset,
the horizontal distance measured from the back of the driver's head to the front
of the head restraint, was not found to be related to neck pain for female
drivers. Backset trends for male drivers could not be evaluated because few male
drivers had head restraints that were high enough for backset to be relevant.
Reported neck pain decreased for older drivers (females only), drivers in less
severe crashes, and drivers in heavier cars (females only); all head restraint
analyses were adjusted for these characteristics. Women, and most likely men, in
the United States would benefit greatly from international harmonization to
European head restraint standards. Until then, both women and men should be
encouraged to adjust their adjustable head restraints, if possible, behind their
heads' centers of gravity and to sit with the backs of their heads as close as
possible to their head restraints.
PMID- 10688486
TI - Report investigating the importance of head restraint positioning in reducing
neck injury in rear impact.
AB - Neck injury resulting from rear impact (often known as whiplash) is a serious
cause of road trauma. It is often underestimated or overlooked because such
injuries are minor on traditional injury scales but can result in long term pain
and disability. The paper begins with a brief review of research into head
restraints and whiplash done so far. A review of international head restraint
regulations revealed the absence of any horizontal offset requirements. A review
of seat strength requirements and testing procedures showed that a regulation
that required a collapsible seat would involve significant compliance testing.
This paper concludes a preliminary project conducted by the Federal Office of
Road Safety (FORS) where the head restraints for twenty Australian market
vehicles were assessed using known performance criteria. A key finding of the
report was that most of the vehicles allowed for vertical adjustment of the head
restraint. Also important was that none of the vehicles measured allowed
horizontal adjustment and on some of the head restraints the horizontal
displacement increased as the vertical height increased. As the understanding of
neck injury mechanisms in rear impact develops, there may be some scope for FORS
to facilitate the improvement of these standards. Further research into neck
injury mechanisms may reveal yielding seat backs or new 'active' head restraint
technology as a more effective countermeasure. In the meantime, educating
occupants to correctly adjust their head restraints seems to be an effective way
to reduce injuries in existing vehicles.
PMID- 10688487
TI - WHIPS--Volvo's Whiplash Protection Study.
AB - Whiplash associated disorders (WAD) resulting from rear end car impacts are an
increasing problem. WAD are usually not life threatening, but are one of the most
important injury categories with regard to long-term consequences. This paper is
a review of Volvo's Whiplash Protection Study (WHIPS), which is the result of
more than ten years of concentrated research efforts in the area of neck injuries
in car collisions, with the focus on rear end car impacts. The study follows the
whole chain from accident research to the development of a seat for increased
protection against WAD. Results from Volvo's accident research are summarized.
Existing biomechanical knowledge regarding possible injury mechanisms are
presented and discussed. Based on the interpretation of accident research and
biomechanical knowledge, guidelines for improved protection against WAD in rear
end impacts are presented. Requirements and test methods based on the guidelines
are explained. An important part of the study is a new rear end impact dummy,
BioRID. Test results using the new dummy are presented. Finally, the paper
explains the design of a new seat for increased WAD protection, the WHIPS-seat.
Results from the accident research and biomechanical research emphasize the
importance of considering the whole spine of the occupant and, accordingly, the
whole seat when addressing WAD in rear end impacts, with a particular focus on
low and moderate impact severity. Low and moderate impact severity crashes should
be focused. Also important to consider are the individual differences between
occupants, the seating position and the variety of seating postures. All results,
including sub-system testing, mathematical modeling, sled testing, as well as
geometrical parameters show that the WHIPS-seat will have considerable potential
for offering increased protection against WAD in rear end impacts.
PMID- 10688488
TI - Comparison of car seats in low speed rear-end impacts using the BioRID dummy and
the new neck injury criterion (NIC).
AB - Long-term whiplash associated disorders (WAD) 1-3 sustained in low velocity rear
end impacts is the most common disability injury in Sweden. Therefore, to
determine neck injury mechanisms and develop methods to measure neck-injury
related parameters are of importance for current crash-safety research. A new
neck injury criterion (NIC) has previously been proposed and evaluated by means
of dummy, human and mathematical rear-impact simulations. So far, the criterion
appears to be sensitive to the major car and collision related risk factors for
injuries with long-term consequences. To further evaluate the applicability of
NIC, four seats were tested according to a recently proposed sled-test procedure.
'Good' as well as 'bad' seats were chosen on the basis of a recently presented
disability risk ranking list. The dummy used in the current tests was the
Biofidelic Rear Impact Dummy (BioRID). The results of this study showed that
NICmax values were generally related to the real-world risk of long-term WAD 1-3.
Furthermore, these results suggested that NICmax calculated from sled tests using
the BioRID dummy can be used for evaluating the neck injury risk of different car
seats.
PMID- 10688489
TI - Intrapleural therapy with MDP-Lys (L18), a synthetic derivative of muramyl
dipeptide, against malignant pleurisy associated with lung cancer.
AB - N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys
(L18), romurtide) is a synthetic muramyl dipeptide derivative, and has
immunomodulating activities including activation of cells of monocyte-macrophage
lineage. We examined the effect of intrapleural instillation of MDP-Lys (L18)
against malignant pleurisy associated with lung cancer. Six patients with
cytologically-positive malignant pleural effusion (four with adenocarcinoma, one
with small cell carcinoma and one with large cell carcinoma) were treated with
single intrapleural instillation of MDP-Lys (L18) of 200 microg. Clinically, no
reaccumulation of pleural effusion for at least 4 weeks was observed in four
patients. No major side effects were observed. Total cell number elevated
remarkably 4 h after instillation, and main increased population was that of
neutrophils. Levels of chemotactic cytokines, such as interleukin (IL)-8, and
monocyte chemotactic protein (MCP)-1 and levels of pro-inflammatory cytokines,
such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6,
elevated in pleural effusion, and peak IL-1beta and IL-6 levels tended to be
higher in clinical responders than non-responders. These results suggest MDP-Lys
(L18) instilled by intrapleural route had a potential local immunomodulatory
activity. Further study is warranted to further determine the critical factors
which correlate with the clinical response.
PMID- 10688490
TI - Gemcitabine monotherapy in elderly patients with advanced non-small cell lung
cancer: a multicenter phase II study.
AB - BACKGROUND: This trial investigated the activity and toxicity of gemcitabine in
previously untreated elderly (> 70 years) patients with advanced (stage IIIB-IV)
non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: From January 1997 to
July 1998, 46 patients with advanced NSCLC aged over 70 years with a performance
status of 0-2 were entered into the study. Gemcitabine 1000 mg/m2 was
administered as a 30-min infusion once a week for 3 weeks followed by a week of
rest; cycles were repeated every 4 weeks. RESULTS: Forty-four patients were
evaluable for response. One complete response and nine partial responses were
observed, for an overall response rate of 22.2% (95% C.I.: 11.3-37.5). The median
time to disease progression was 5.1 months (95% C.I.: 3.5-6.7), the median
duration of response was 6.3 months, and the median overall survival time 6.75
months (95% C.I.: 5.3-8.2). All patients were evaluable for toxicity (184 cycles,
median = 3 cycles/patient) and no grade 4 hematologic toxicities were reported.
WHO grade 3 leukopenia, neutropenia and anemia occurred in 3.3, 0.5 and 1.1% of
cycles, respectively. Grade 3 skin rash occurred in 4.3% of patients. These side
effects led to treatment discontinuation in two patients. CONCLUSION: Our data
show that gemcitabine is active and well tolerated in patients aged over 70 years
with advanced NSCLC.
PMID- 10688491
TI - Angiogenesis and non-small cell lung cancer.
AB - Lung cancer is the commonest cause of cancer death in the western world. Recent
evidence suggests that angiogenesis is related to poor prognosis in many solid
tumours including non-small cell lung cancer. Angiogenesis is controlled by a
complex interaction between growth and apoptotic factors, proteases and adhesion
molecules. The angiogenic process may prove a target for novel therapies such as
matrix metalloproteinase inhibitors, growth factor antisense RNA, growth factor
receptor antagonists and naturally occurring antiangiogenic peptides. These
agents may be used alone or in combination with traditional chemotherapy,
radiotherapy and surgery.
PMID- 10688492
TI - Surgical treatment of lung cancer with adrenal metastasis.
AB - Surgical treatment of adrenal metastasis from non-small cell lung cancer is
controversial. Classically this group of patients has been considered incurable,
therefore excision of the primary cancer and the adrenal gland has been avoided.
However, recent reports show good results in their surgical management. Five
selected patients with non-small cell lung cancer and adrenal metastases have
been surgically treated. Two of them also presented with brain metastases that
were excised, too. One patient with brain and adrenal metastases died 38 months
after surgery. The other four patients are alive and with no sign of recurrent
disease at 8, 16, 52 and 58 months of follow-up. In highly selected patients in
whom both the primary and the metastatic tumors are resectable and in the absence
of tumor spread to other organs, surgical treatment seems to be a good
therapeutic option.
PMID- 10688493
TI - Incidence of lung cancer in Denmark: historical and actual status.
AB - This is a registry-based analysis of 97,281 lung cancer patients diagnosed in
Denmark during the period 1943-1994. The development of lung cancer incidence in
Denmark in the study period is described and this information is used to predict
the future trends in lung cancer in Denmark. Since 1960, lung cancer has been the
most frequent type of cancer in Danish men, excluding skin cancer. The incidence
in men reached its maximum in 1985, when it was 100 new cases per 100,000
inhabitants, whereafter the incidence began to level off and was 83 per 100,000
inhabitants in 1994. During the study period, the incidence of lung cancer in
Danish women was somewhat lower than in men. The incidence in women has been
steadily increasing since 1960 by approximately 20% per each 5-year period, and
was 46 per 100,000 inhabitants in 1994. Adenocarcinoma is the most frequent
histological subtype in women and the only subtype increasing in incidence in
men. Taking the actual development into account, the incidence of lung cancer
will continue to fall among men and rise among women, leading to a reversal of
the classical gender ratio in about 15 years.
PMID- 10688494
TI - Early hilar lung cancer--clinical aspects and long term survival. Identification
of a subgroup of stage IA patients with more favorable prognosis.
AB - Twenty-nine patients out of 2018 operated on for a non-small-cell lung cancer
from 1987 to February 1998 met the criteria proposed by the Japan Lung Cancer
Society (JLCS) for the definition of early hilar lung cancer (EHLC). Twenty-six
patients were symptomatic and 20 had a radiologically visible lesion. All cancers
were located and diagnosed by bronchoscopy and all patients were resected. At
histology, all tumors were squamous in nature. The five-year cumulative survival
rate was 96%--a second primary lung cancer (2nd Pr.) developed in 4 patients
(13.8%). The definition of EHLC proposed by the JLCS allows the selection of a
subgroup of stage I patients with a very good prognosis. Nevertheless, a close
follow-up is mandatory because more than 10% of these patients develop a 2nd Pr.
PMID- 10688495
TI - Synchronous four primary lung adenocarcinoma associated with multiple atypical
adenomatous hyperplasia.
AB - A 69-year-old woman with synchronous bilateral 4 primary lung adenocarcinoma
accompanied by multiple atypical adenomatous hyperplasia (AAH) is described. The
patient was found to have bilateral multiple tumors during a preoperative chest
CT evaluation which was performed for the previously-diagnosed adenocarcinoma of
the right middle lobe. Since intraoperative diagnosis of the left nodular lesion
was adenocarcinoma and judged to be a pulmonary metastasis, a lobectomy of the
right middle lobe only was performed. Postoperative pathological diagnosis
including immunohistochemical findings demonstrated that the bilateral lesions
were synchronous multiple primary adenocarcinoma, independent of each other and
associated with multiple AAH. This case suggests the possibility of the AAH
adenocarcinoma sequence in the development of lung cancer. In addition, the
strategy of treatment for synchronous multiple adenocarcinoma should be
considered.
PMID- 10688496
TI - Sling techniques in the treatment of genuine stress incontinence.
PMID- 10688497
TI - Altered peripheral vascular response of women with and without pelvic pain due to
congestion.
AB - OBJECTIVE: To test the hypothesis that women with pelvic venous congestion have a
reduction of reactivity of their peripheral circulation. DESIGN: Comparison was
made between 20 women with chronic pelvic pain due to congestion and a control
group of 15 pain-free women matched for age, parity and body weight. A comparison
of these results was made with those from six postmenopausal women taking hormone
replacement therapy. METHODS: Study and control groups were investigated during
the mid-follicular phase of the menstrual cycle (days 5-9) and the mid-luteal
phase (days 19-23). The study group was also investigated during the fifth month
of treatment with suppression of ovarian activity with leuprorelin or
medroxyprogesterone acetate or six months after hysterectomy and bilateral
salpingo-oophorectomy. Head-up tilt sufficient to increase intra-vascular
pressure in the toe by a standard 40 mmHg was used as a means of raising venous
pressure in the lower limb. Skin capillary red blood cell velocity (flux) was
measured using a laser Doppler flow probe placed over the pulp of the big toe.
Heart rate and blood pressure were also recorded. The change in skin blood flow
following head-up tilt was expressed as a percentage of baseline flow in the
supine position. MAIN OUTCOME MEASURES: Percentage change in skin red blood cell
flux, heart rate and blood pressure in response to 40 degrees head-up tilt.
RESULTS: In the control group the median response to head-up tilt in the
follicular phase was one of a reduction in flux, whereas in the luteal phase it
was more variable ranging from an increase to a decrease in flux. The responses
in the pelvic congestion group in both the follicular and luteal phases were
similar to those of the control group in the luteal phase. A small but
significant increase in heart rate in response to tilt in the pelvic pain group,
compared with the control group, was interpreted as being due to a fall in venous
return. Treatment of the pelvic congestion group by medical suppression of
ovarian activity or total hysterectomy with bilateral salpingo-oophorectomy
resulted in a significant change in response to head-up tilt from the variable
type of luteal response to one of a more constant reduction in flux, similar to
that of the control group in the follicular phase. A reduction in flux was also
found consistently in postmenopausal women. CONCLUSION: The study confirms the
hypothesis that women with pelvic pain due to congestion show a change in
peripheral vascular reactivity which returns to normal after suppression of
ovarian activity. It seems likely that some alteration of normal ovarian function
is responsible for the observed changes in peripheral blood flow in response to a
rise in venous pressure in women with pelvic congestion.
PMID- 10688498
TI - Performance of ultrasound as a second line test to serum CA125 in ovarian cancer
screening.
AB - OBJECTIVE: To assess the performance of ultrasonography in a multimodal ovarian
cancer screening strategy. DESIGN: Prospective ovarian cancer screening trial
between December 1986 and June 1993. SETTING: General practice, occupational
health departments and an ovarian cancer screening clinic at a London teaching
hospital. POPULATION: Postmenopausal women, > or = 45 years with a raised CA125.
METHODS: Volunteers with a CA125 > or = 30 U/mL underwent a pelvic ultrasound.
Scans were classified as normal, abnormal (ovarian volume > or = 8.8 mL) or
equivocal (normal volume with abnormal morphology). Abnormal ovarian morphology
was subclassified as simple cyst (single, thin walled cyst with no septa or
papillary projections) or complex (all other abnormalities). Volunteers with
abnormal scans were referred for a gynaecological opinion. Follow up was via the
cancer registry and postal questionnaires. MAIN OUTCOME MEASURES: Sensitivity,
specificity and positive predictive value of different ultrasound criteria for
detection of index cancer (e.g. primary invasive epithelial carcinoma of the
ovary and fallopian tube). RESULTS: Seven hundred and forty-one women underwent
1,219 scans and 20 index cancers occurred during a median follow up of 6 x 8
years. The sensitivity for detection of ovarian cancer of different ultrasound
criteria was 100% for abnormal morphology, 89 x 5% for abnormal volume and 84%
for complex morphology. The highest specificity (97%) and positive predictive
value (37 x 2%) was achieved using complex morphology. CONCLUSION: A variety of
ultrasound criteria can achieve high sensitivity, specificity and positive
predictive value for index cancers in postmenopausal women with an elevated
CA125. Use of ovarian morphology to interpret ultrasound may increase sensitivity
and use of complex ovarian morphology may increase the positive predictive value.
PMID- 10688499
TI - Gynaecological presentation of retroperitoneal tumours.
AB - OBJECTIVE: To illustrate the problems associated with mistaken pre-operative
diagnosis following gynaecological presentation of patients with retroperitoneal
tumours. DESIGN: A case series of five referrals. RESULTS: Non-gynaecological
tumours were not suspected in each case and hence there was a failure to
undertake further pre-operative investigation and referral to a specialised soft
tissue sarcoma service. This resulted in four of the patients having an
unnecessary laparotomy with an inappropriate transperitoneal biopsy undertaken
when the retroperitoneal tumour was discovered. The mistaken diagnosis of ovarian
malignancy lead to increased morbidity, compromise of potential for a long
disease free interval and/or possibly lessened the chance of cure in each case.
CONCLUSIONS: Misinterpretation of clinical signs and an over-reliance on
ultrasound diagnosis were the commonest causes of inappropriate management of
these patients. Gynaecologists should consider more frequently the other, less
common differential diagnoses of a pelvic mass. This is especially true in
circumstances with a predominantly solid tumour, where there are clinical signs
of vascular or rectal displacement, or where there is ultrasound evidence of
ureteric obstruction. The more frequent utilisation of a computerised tomography
scan with intravenous and oral contrast with referral before inappropriate
transperitoneal biopsy are recommended as complete en bloc surgical excision at
the first laparotomy is the treatment of choice in virtually all primary
retroperitoneal tumours.
PMID- 10688500
TI - Can diagnostic laparoscopy be avoided in routine investigation for infertility?
AB - OBJECTIVE: To determine whether routine testing for serum Chlamydia trachomatis
antibodies, considered in combination with a woman's clinical features, may avoid
the need for diagnostic laparoscopy in routine investigation for infertility.
DESIGN: Retrospective case notes analysis. SETTING: Secondary level care
infertility clinic. POPULATION: Eighty women who had undergone both laparoscopy
and serum Chlamydia trachomatis antibody testing. METHODS: Ascertainment of any
history of suspected pelvic inflammatory disease, pelvic pain, cervical
intraepithelial neoplasia, pelvic surgery or appendicectomy; any abnormality on
clinical pelvic examination; the findings at laparoscopy; the result of serum
Chlamydia trachomatis antibody testing by enzyme-linked immunosorbent assay
(ELISA) screening with microimmunofluorescence (MIF) confirmatory diagnostic
testing. The usefulness of clinical features, the serum Chlamydia trachomatis
antibody test and these two variables combined in the detection of tubal disease
and pelvic pathology of relevance to infertility were measured statistically.
MAIN OUTCOME MEASURES: Specificity, sensitivity, positive predictive value,
negative predictive value and likelihood ratio for each of the tests. RESULTS:
The combination of any positive clinical feature with a positive test for serum
Chlamydia trachomatis antibodies detects tubal disease with sensitivity 92%,
specificity 70%, positive predictive value 72%, negative predictive value 91% and
likelihood ratio 3 x 1; it detects bilateral tubal obstruction with sensitivity
84%, specificity 51%, positive predictive value 35%, negative predictive value
91% and likelihood ratio 1 x 7; it detects pelvic pathology relevant to
infertility with sensitivity 76%, specificity 71%, positive predictive value 80%,
negative predictive value 65% and likelihood ratio 2 x 6. The negative predictive
value for pelvic pathology from the use of clinical features in addition to the
chlamydia antibody test is not significantly higher than that from the chlamydia
antibody test alone (53%). CONCLUSIONS: A policy of selective laparoscopy in
routine investigation for infertility, based on the result of the test for serum
Chlamydia trachomatis antibodies and a woman's clinical features, is not
supported.
PMID- 10688501
TI - Births in Finland and Estonia from 1992 to 1996: convergent differences?
AB - OBJECTIVE: To describe the differences in childbearing, in prenatal and
obstetrical practices, and in perinatal health outcome in Finland and Estonia.
DESIGN: Registry study using the data from the Finnish and Estonian medical birth
registries for years 1992 to 1996 (in total 324,021 and 74,297 newborns,
respectively). RESULTS: In 1992 the birth rates were 51 per 1,000 women aged 15
to 49 in Finland and 48 per 1,000 in Estonia. The birth rate declined in the
study period in both countries, but the decline was more rapid in Estonia (-26%)
than in Finland (-6%). In the same period the rates of induced abortion declined
in both countries (-34% and -6%, respectively), but the rate in 1996 was still
much higher in Estonia (46/1,000) than in Finland (8/1,000). Compared with
Finnish mothers, Estonian mothers were younger, had fewer multiple births, less
prenatal care and fewer interventions during pregnancy and delivery. The
intervention rates increased in both countries during the study period, but this
increase was more rapid in Estonia. The infant outcomes were poorer in Estonia,
but the differences between Estonia and Finland decreased during the 1990's.
CONCLUSIONS: The differences in prenatal and maternal care and in induced
abortion rates have decreased between Estonia and Finland. Changes in maternal
backgrounds, improved referral system for complicated pregnancies, improvements
in prenatal care and in availability of appropriate equipment and technology may
have caused improved maternal and infant health in Estonia, but this should be
further investigated.
PMID- 10688502
TI - Women's sexual health after childbirth.
AB - OBJECTIVE: To investigate the impact of childbirth on the sexual health of
primiparous women and identify factors associated with dyspareunia. DESIGN: Cross
sectional study using obstetric records, and postal survey six months after
delivery. SETTING: Department of Obstetrics and Gynaecology, St George's
Hospital, London. POPULATION: All primiparous women (n = 796) delivered of a live
birth in a six month period. METHODS: Quantitative analysis of obstetric and
survey data. MAIN OUTCOME MEASURES: Self reported sexual behaviour and sexual
problems (e.g. vaginal dryness, painful penetration, pain during sexual
intercourse, pain on orgasm, vaginal tightness, vaginal looseness,
bleeding/irritation after sex, and loss of sexual desire); consultation for
postnatal sexual problems. RESULTS: Of the 484 respondents (61% response rate),
89% had resumed sexual activity within six months of the birth. Sexual morbidity
increased significantly after the birth: in the first three months after delivery
83% of women experienced sexual problems, declining to 64% at six months,
although not reaching pre-pregnancy levels of 38% . Dyspareunia in the first
three months after delivery was, after adjustment, significantly associated with
vaginal deliveries (P = 0 x 01) and previous experience of dyspareunia (P = 0 x
03). At six months the association with type of delivery was not significant (P =
0 x 4); only experience of dyspareunia before pregnancy (P < 0 x 0001) and
current breastfeeding were significant (P = 0 x 0006). Only 15% of women who had
a postnatal sexual problem reported discussing it with a health professional.
CONCLUSIONS: Sexual health problems were very common after childbirth, suggesting
potentially high levels of unmet need.
PMID- 10688503
TI - How useful is uterine artery Doppler flow velocimetry in the prediction of pre
eclampsia, intrauterine growth retardation and perinatal death? An overview.
AB - OBJECTIVE: To evaluate the clinical usefulness of Doppler analysis of the uterine
artery velocity waveform in the prediction of pre-eclampsia and its associated
complications of intrauterine growth retardation and perinatal death. DESIGN:
Quantitative systematic review of observational diagnostic studies using online
searching of the MEDLINE database coupled with scanning of the bibliographies of
primary and review articles including known unpublished studies. MATERIAL: Twenty
seven studies involving 12,994 subjects stratified into population subgroups at
low and high risk of developing pre-eclampsia and its complications. OUTCOME
MEASURES: The outcome measures studied were: 1. the development of pre-eclampsia;
2. intrauterine growth retardation; and 3. perinatal death. The main meta
analyses were the flow velocity waveform ratio +/- diastolic notch derived by
transabdominal Doppler ultrasound as the measurement parameter. The analyses were
conducted using likelihood ratio as a measure of diagnostic accuracy. A
likelihood ratio of 1 indicates that the test has no predictive value for the
outcome. Prediction for the outcome event is considered conclusive with
likelihood ratios of > 10 or < 0 x 1 for a positive and negative test result,
respectively. Moderate prediction can be achieved with likelihood ratios of 5-10
and 0 x 1-0 x 2 whereas likelihood ratios values of 1-5 and 0 x 2-1 would
generate only minimal prediction. RESULTS: In the low risk population a positive
test result, predicted pre-eclampsia with a pooled likelihood ratio of 6 x 4 (95%
CI 5 x 7-7 x 1), while a negative test result had a pooled likelihood ratio of 0
x 7 (95% CI 0 x 6-0 x 8). For intrauterine growth retardation the pooled
likelihood ratio was 3 x 6 (95% CI 3 x 2-4 x 0) for a positive test result and 0
x 8 (95% CI 0 x 8-0 x 9) for a negative test result. Using perinatal death as
outcome measure, the pooled likelihood ratio was 1 x 8 (95% CI 1 x 2-2 x 9) for a
positive test result and 0 x 9 (95% CI 0 x 8-1 x 1) for a negative test result.
In the high risk population a positive test result predicted pre-eclampsia with a
pooled likelihood ratio of 2 x 8 (95% CI 2 x 3-3 x 4), while a negative test had
a likelihood ratio of 0 x 8 (95% CI 0 x 7-0 x 9). For intrauterine growth
retardation the pooled likelihood ratio was 2 x 7 (95% CI 2 x 1-3 x 4) for a
positive test result and 0 x 7 (95% CI 0 x 6-0 x 9) for a negative result. For
perinatal death the pooled likelihood ratio was 4 x 0 (95% CI 2 x 4-6 x 6) for a
positive test result and 0 x 6 (95% CI 0 x 4-0 x 9) for a negative result.
CONCLUSION: Uterine artery Doppler flow velocity has limited diagnostic accuracy
in predicting pre-eclampsia, intrauterine growth retardation and perinatal death.
PMID- 10688504
TI - Introduction of the Misgav Ladach caesarean section at an African tertiary
centre: a randomised controlled trial.
AB - OBJECTIVE: To determine whether the Misgav Ladach caesarean section technique can
offer benefits compared with conventional caesarean section technique in the
prevailing conditions of a busy African tertiary centre. DESIGN: A randomised
controlled trial. SETTING: A tertiary African obstetric unit with 18,000
deliveries annually. PARTICIPANTS: Three hundred and thirty-nine women undergoing
caesarean section. METHODS: Eight residents and registrars were instructed in the
Misgav Ladach technique for caesarean section during one week, after which the
study commenced. The course participants instructed their colleagues; in total,
16 doctors participated. Women requiring caesarean section were randomised to
Misgav Ladach or to the conventional lower midline incision procedure, excluding
those with a previous scar. RESULTS: During 11 weeks 339 randomised procedures
(328 of which were emergency procedures) were carried out. Mean operating time
was 25 x 3 minutes for Misgav Ladach and 32 x 6 minutes for the lower midline
incision procedure (95% CI -8 x 3; -6 x 3). Mean blood loss was 354 mL and 447 mL
(-133; -53), and the number of sutures 3 x 1 and 6 x 1 (-3 x 1; -2 x 9),
respectively. No significant difference was found in Apgar scores. Mobilisation
was earlier with the Misgav Ladach procedure. No difference was found in overall
post-operative infection rates i.e. wound infection or febrile illness, but the
combination of wound infection and fever was more common in the Misgav Ladach
group. CONCLUSION: The Misgav Ladach caesarean section confers benefits such as
reduced blood loss, conservation of time and suture material, and rapid
mobilisation, but more studies are needed to explore modifications aimed at
reducing post-operative infections in settings with limited resources.
PMID- 10688505
TI - Antenatal home blood pressure monitoring: a pilot randomised controlled trial.
AB - OBJECTIVE: To measure recruitment to, compliance with, and the acceptability of a
trial designed to test whether a reduced schedule of antenatal visits combined
with training in self-measurement of blood pressure at home may improve
hypertension screening and save money. To test the specific hypothesis that even
after taking into account extra unscheduled visits, the reduced schedule with
ambulatory monitoring reduces total visits. DESIGN: A pilot randomised controlled
trial. SETTING: Four urban and four rural general practices in Yorkshire and
Lancashire. POPULATION: One hundred and five low risk women in the third
trimester of pregnancy. Eighty women participated. INTERVENTION: Women were
invited to participate at 24-28 weeks. Those who accepted were allocated either
to a standard nine subsequent visit schedule (30, 32, 34, 36, 37, 38, 39, 40, 41
weeks) or to a reduced schedule (34, 38, 41 weeks). Those in the latter group
measured their blood pressure weekly using a portable sphygmomanometer at home.
MAIN OUTCOME MEASURES: Recruitment, total number of clinic visits, frequency of
blood pressure measurement, schedule preference, and anxiety. RESULTS: Although
there were more unscheduled visits in the home monitoring group, this did not
outweigh the reduction in scheduled visits, (total visits reduced from 7 x 4 to 4
x 5, P < 0 x 001), and blood pressure was measured during more weeks (9 vs 7
weeks, P < 0 x 001) in the experimental group. Most women expressed a preference
for the reduced schedule both when the idea was first suggested, and after they
had experienced it, and there were no significant differences in anxiety.
CONCLUSION: Replacement of antenatal screening visits with home blood pressure
monitoring is acceptable to women. The reduction in clinic visits is not
compensated by an increase in visits for other reasons and overall blood pressure
measurement is omitted less often. Whether it reduces adverse outcomes or has any
rare side effects will require a larger trial, but this pilot study indicates
that it is likely to be safe, and that such a large trial would be feasible.
PMID- 10688506
TI - Labour characteristics and uterine activity: misoprostol compared with oxytocin
in women at term with prelabour rupture of the membranes.
AB - OBJECTIVE: To compare the labour pattern and uterine activity of oral misoprostol
with oxytocin for labour induction in women presenting with prelabour rupture of
membranes at term. DESIGN: Prospective randomised study. SETTING: Department of
Obstetrics and Gynaecology, Queen Mary Hospital, Hong Kong. PARTICIPANTS: Eighty
women presenting with prelabour rupture of membranes at term. METHODS: The women
were randomised to receive either 100 microg misoprostol orally every 4 hours to
a maximum of three doses, or intravenous oxytocin infusion according to the
hospital protocol. Intrauterine pressure transducers were inserted one hour
before induction of labour in both groups of women. We compared the pattern of
uterine activity, the induction-to-delivery interval, duration of labour, mode of
delivery and neonatal outcome between the two groups. RESULTS: Both oxytocin and
oral misoprostol caused an increase in uterine activity within one hour of labour
induction. Peak uterine activity was reached 6-8 h after oral misoprostol, with
persistent effects, and 8-10 h after oxytocin, requiring continuous titration of
medication. The duration of labour was significantly reduced in nulliparous
women, but not in those who were multiparous in the misoprostol group. The
induction-to-delivery interval, the mode of delivery and the perinatal outcome
were similar for the two groups. CONCLUSION: Oral misoprostol caused earlier peak
uterine activity, compared with oxytocin (6-8 h vs 8-10 h). Oral misoprostol was
not only as effective as oxytocin in inducing labour in women at term with
prelabour rupture of the membranes, but it reduced significantly the duration of
labour in nulliparous women.
PMID- 10688507
TI - Early pregnancy predictors of preterm birth: the role of a prolonged menstruation
conception interval.
AB - OBJECTIVE: To study early pregnancy characteristics as possible risk factors
associated with preterm birth. DESIGN: Retrospective analysis of prospectively
collected maternity data. POPULATION: 21,069 singleton deliveries with record of
a specified last menstrual period and a midtrimester dating scan. SETTING:
Catchment area of tertiary centre serving a general maternity population.
METHODS: Univariate and multivariate analysis. Variables included: maternal age;
height; weight at first visit; parity; ethnic group; cigarette smoking and
alcohol consumption recorded in early pregnancy; history of abortion; history of
preterm birth; and discrepancy between menstrual dates and ultrasound dates. MAIN
OUTCOME MEASURES: Adjusted odds ratios for factors associated with preterm birth,
stratified according to parity (nulliparae vs multiparae) and gestational age
(early preterm, 24-33 weeks; late preterm, 34-36 weeks; all preterm, < 37 weeks).
Population attributable risk (aetiologic fraction) of the significant variables
for preterm birth. RESULTS: The overall preterm (< 37 weeks) delivery rate
according to scan dates was 7 x 0%. Preterm birth was associated with young (< 20
years), short (< or = 155 cm) and underweight (< or = 52 kg) mothers, non
Europeans, cigarette smokers, previous abortion or previous preterm delivery, and
a prolonged menstruation-conception interval. Preterm births which followed the
spontaneous onset of labour (72%) had results which were similar to the overall
group, while there were too few iatrogenic preterm deliveries for separate
analysis. Logistic regression showed that associations varied in different parity
and gestational age groups. For nulliparae, smoking was not associated with
preterm birth, but it was strongly associated with multiparous women (adjusted OR
1 x 8, 95% CI 1 x 6-2 x 1). A past history of premature delivery had the highest
risk for birth before 34 weeks in the index pregnancy (adjusted OR 5 x 1, 95% CI
3 x 4-7 x 6). A discrepancy between menstrual and scan dates of greater than +7
days, suggestive of a prolonged interval between last menstruation and
conception, was present in 23 x 3% of all pregnancies, and was associated with an
increased risk of preterm delivery in all gestational age categories for
nulliparae (adjusted OR 1 x 5, 95% CI 1 x 3-1 x 8) and multiparae (adjusted OR 1
x 9, 95% CI 1 x 6-2 x 2). Because of its high prevalence, this variable
constituted a relatively high population-attributable risk for premature birth
for both nulliparae (10 x 7%) and multiparae (16 x 6%). CONCLUSIONS: A
discrepancy of more than +7 days between menstrual and scan dates, indicating a
prolonged interval between last menstruation and conception, is a significant
predictor of preterm birth. This effect is independent of other factors such as
maternal age, height, weight and smoking which are also associated with
prematurity. In a maternity population with ultrasound scan dates and recorded
last menstrual period, this variable can be easily calculated and used as a
marker for increased surveillance.
PMID- 10688508
TI - Does a discrepancy between gestational age determined by biparietal diameter and
last menstrual period sometimes signify early intrauterine growth retardation?
AB - OBJECTIVE: To assess the association between gestational age estimated from the
last menstrual period (GA(LMP)) or from the biparietal diameter (GA(BPD)), and
the subsequent birthweight for gestational age. DESIGN: Population-based follow
up study. SETTING: Of 21,936 pregnancies contained in the ultrasound database,
16,387 singleton pregnancies with a reliable last menstrual period date and an
ultrasound examination between 12 and 22 weeks of gestation were included. MAIN
OUTCOME MEASURES: Correlation between: 1) birthweight deviation (birthweight
expected weight for gestation); 2) birthweight; and 3) pregnancy length and
(GA(LMP)-GA(BPD)). Relative risk of birthweight < 2,500 g and low birthweight for
gestation (> 22% below normal weight) related to five levels of discrepancy
between (GA(LMP)-GA(BPD)). RESULTS: (GA(LMP)-GA(BPD)) was not associated with
deviation of birthweight related to GA(BPD). However the risk of low birthweight
(< 2,500 g) and low birthweight for gestational age was significantly increased
when (GA(LMP)-GA(BPD)) was > 7 days. CONCLUSION: A biparietal diameter smaller
than expected from the last menstrual period date is mainly a problem of an error
related to estimated time of ovulation. At the same time the relative risk of a
low birthweight infant is slightly increased.
PMID- 10688509
TI - Pregnancy outcomes and cardiac complications in women with mechanical,
bioprosthetic and homograft valves.
AB - OBJECTIVES: Firstly, to compare pregnancy outcomes and cardiac complications in
women with: 1) either mechanical or bioprosthetic valves at the mitral site; 2)
mechanical valves treated with warfarin or subcutaneous heparin. Secondly, to
determine pregnancy and cardiac outcomes in women with aortic homograft valves.
DESIGN: Historical cohort study. SETTING: Greenlane Hospital, Auckland, New
Zealand. POPULATION: Young women (n = 255) who had valve replacements between
1972 and 1992. Seventy-nine women underwent 147 pregnancies. MAIN OUTCOME
MEASURES: Pregnancy loss, cardiac complications. RESULTS: Pregnancy loss occurred
in 59% of pregnancies with mitral mechanical valves (n = 50) and 7% with mitral
bioprosthetic valves (n = 33) (RR 8 x 20, 95% CI 2 x 10-31 x 93). Pregnancy loss
rate was 70% in pregnancies treated with warfarin, compared with 25% for those
switched from warfarin to heparin (RR 2 x 81, 95% CI 1 x 03-7 x 73). All heparin
associated losses occurred in the first trimester, whereas there were four
stillbirths with warfarin. Cardiac complications occurred in 10 pregnancies (20%)
in the women with mitral mechanical valves and four (13%) with mitral
bioprosthetic valves (RR 1 x 55, 95% CI 0 x 53-4 x 52). All four thromboembolic
complications with mechanical valves occurred in the 14 women treated with
heparin throughout pregnancy. Structural valve deterioration occurred in four
pregnancies (10%) with mitral bioprosthetic valves. No cardiac complications or
known pregnancy losses occurred with aortic homograft valves (n = 41).
CONCLUSION: The high pregnancy loss rate in women with mitral mechanical valves
was associated with warfarin throughout pregnancy, whereas the thromboembolic
cardiac complications were associated with heparin. Pregnancy outcome was very
good in women with bioprosthetic and homograft valves.
PMID- 10688510
TI - The outcome of 72 pregnancies in 55 women with cystic fibrosis in the United
Kingdom 1977-1996.
AB - OBJECTIVE: To identify pregnancies in women with cystic fibrosis and describe
obstetric, infant and maternal medical outcomes in relation to the severity of
maternal disease. DESIGN: Retrospective study, based on casenotes. SETTING:
Eleven cystic fibrosis centres in the United Kingdom. POPULATION: Pregnant women
with cystic fibrosis. METHODS: Single observer medical and obstetric casenote
review categorising maternal cystic fibrosis (e.g. genotype, pancreatic, hepatic
and diabetic status) and pre-pregnant severity (e.g. weight and lung function)
and noting fetal outcome and maternal morbidity. MAIN OUTCOME MEASURES: Completed
pregnancies and pregnancy losses, fetal outcome and complications, maternal
morbidity, such as changes in weight, lung function, pulmonary infections during
and after pregnancy. Relation of outcomes to severity of maternal cystic
fibrosis. RESULTS: From 72 pregnancies identified, the outcomes were known for
69; there were 48 live births (70%) of which 22 were premature (46%); 14
therapeutic abortions (20%); and 7 miscarriages (10%). There were no stillbirths,
neonatal or early maternal deaths. Three major fetal anomalies were seen, but no
infant had cystic fibrosis. At the conclusion of our study three pregnancies were
still continuing. Prematurity with increased fetal complications and maternal
morbidity with infection, declining lung function and poor weight gain were
associated with poor pre-partum lung function. CONCLUSION: Pregnancy occurs in
women with cystic fibrosis of all degrees of severity. Outcomes for the infant
are generally good but are variable for the mother. Predicting outcome on the
basis of maternal severity is difficult but lung function appears to be the most
significant determining factor. Pregnancy may be normal in women with normal lung
function (forced expiratory volume > 80%). However, it may adversely affect mild
and moderate lung disease due to cystic fibrosis and should be avoided in
pulmonary hypertension, cor pulmonale and when forced expiratory volume < 50%
predicted. Ideally, all pregnancies should be planned with prior counselling and
monitored by dedicated cystic fibrosis teams, including obstetricians who are
experienced in managing high risk pregnancies.
PMID- 10688511
TI - Effectiveness of prenatal chromosomal analysis using multicolor fluorescent in
situ hybridisation.
AB - OBJECTIVE: To evaluate the clinical effectiveness of multicolour fluorescent in
situ hybridisation (FISH) analysis in routine prenatal diagnosis. DESIGN:
Prospective study. SAMPLE: 3,203 amniotic fluid samples. METHODS: Unique DNA
(chromosomes 13 and 21) and alpha satellite centromeric-specific (chromosomes X,
Y and 18) probes were used in two mixes to permit the simultaneous analysis of
several chromosomes. The performance of multicolour FISH and conventional
cytogenetic analysis was compared. RESULTS: Conventional cytogenetic analysis
identified 111 chromosomal abnormalities, of which 94 were potentially detectable
by the FISH technique and 97 would be typically associated with neonatal
phenotypic abnormalities. Multicolour FISH analysis detected 84% (93/111) of all
chromosome abnormalities and 99% (93/94) of abnormalities where there was a
specific probe. The sensitivity of multicolour FISH analysis was 95% (92/97) for
chromosomal abnormalities likely to result in an abnormal postnatal outcome.
Multiple ultrasound abnormalities were detected in all five cases of clinically
relevant chromosomal abnormalities missed by multicolour FISH. FISH results were
available within 48 hours and the sample failure rate was 0 x 1% (3/3,202).
CONCLUSION: Multicolour FISH analysis is a sensitive and reliable technique for
the rapid prenatal diagnosis of chromosomal abnormalities. Examining only five
chromosomes allowed 95% of clinically relevant chromosomal abnormalities to be
diagnosed correctly. As routine antenatal screening is targeted at the major
autosomal trisomies and sex chromosome aneuploidies, multicolour FISH analysis
may potentially replace conventional cytogenetic analysis in routine prenatal
diagnosis.
PMID- 10688512
TI - Prostaglandin endoperoxide H synthase mRNA expression in the fetal membranes
correlates with fetal fibronectin concentration in the cervico-vaginal fluids at
term: evidence of enzyme induction before the onset of labour.
AB - OBJECTIVE: To determine the relationship of prostaglandin endoperoxide H synthase
(PGHS) expression in the gestational tissues and fetal fibronectin in cervico
vaginal fluids before the onset of labour at term. DESIGN: Cross-sectional,
observational study. SAMPLES: Amnion, chorion laeve and decidua were collected
from 24 term pregnant women following elective caesarean section. Samples of
cervico-vaginal secretions were obtained from the same women immediately before
caesarean section. METHODS: PGHS-1 and PGHS-2 mRNA levels in tissues were
determined by specific ribonuclease protection assays. Fetal fibronectin
concentrations in the cervico-vaginal fluids were measured by enzyme-linked
immunosorbent assay. The abundance of PGHS mRNA was compared between groups of
patients with the same mean gestational age but different cervico-vaginal fetal
fibronectin levels. Linear regression analysis was used to determine the
association between PGHS levels and fetal fibronectin. RESULTS: Two groups of
women were identified who had significantly different fetal fibronectin values
but the same gestational ages. The group with the higher fetal fibronectin
concentrations had significantly higher PGHS- 1 and PGHS-2 mRNA levels in the
chorion laeve and higher PGHS-2 mRNA levels in the amnion, than the group with
lower fetal fibronectin concentrations. PGHS- 1 and PGHS-2 mRNA levels in the
chorion laeve and PGHS-2 mRNA in the amnion showed an overall significant
association with fetal fibronectin levels. CONCLUSIONS: High concentrations of
fetal fibronectin in cervico-vaginal secretions before the onset of spontaneous
labour at term are associated with high levels of PGHS-2 mRNA in the chorion
laeve and the amnion and of PGHS- 1 mRNA in the chorion laeve. Increased
expression of PGHS in these tissues may therefore be involved in the events
leading to term birth.
PMID- 10688513
TI - The RUMI manipulator and Koh colpotomiser system for total laparoscopic
hysterectomy.
AB - The initial experience in 25 patients of using the Koh Colpotomiser System in
conjunction with the RUMI Manipulator, a new modified technique for performing
total laparoscopic hysterectomy, is presented. Of 25 operations, 23 (92%) were
completed successfully. Complications were limited to minor pre-operative
haemorrhage in two patients and post-operative bleeding in another. The Koh
Colpotomiser System successfully maintained a pneumoperitoneum following
colpotomy, giving the operator improved visibility and access to the pelvic
organs. This resulted in greater efficiency, while eliminating the difficulties
of vaginal access.
PMID- 10688514
TI - The relation between tissue kallikrein excretion rate, aldosterone and glomerular
filtration rate in human pregnancy.
AB - The changes in renal kallikrein synthesis through normal pregnancy and its
relation to aldosterone excretion and the glomerular filtration rate was
investigated. Overnight urinary kallikrein and aldosterone excretion rates and
glomerular filtration rate were measured at 18 weeks, 34 weeks, term and
postpartum in normal human pregnancy. Kallikrein excretion was raised at 18 weeks
compared with the nonpregnant state (P < 0 x 001) but was significantly reduced
at term. The reduction in renal kallikrein was not due to falling aldosterone
concentration, which increased in the third trimester, compared with 18 weeks (P
= 0 x 002) and remained elevated at term compared with the nonpregnant state (P <
0 x 001). Glomerular filtration rate remained elevated at term despite the
reduced kallikrein excretion rate. These data are consistent with the hypothesis
that increased aldosterone production is one factor responsible for increased
kallikrein synthesis which contributes to elevated glomerular filtration rate in
early pregnancy. Other factors clearly inhibit renal kallikrein production at
term. In the face of plasma volume expansion associated with increased mineralo
corticoid production, the effects of reduced kallikrein synthesis at term on
glomerular perfusion and reabsorption of sodium by the distal tubule may
predispose to blood pressure elevation in late pregnancy.
PMID- 10688515
TI - Good prognosis for psychomotor development in survivors with nonimmune hydrops
fetalis.
AB - We examined the psychomotor development of 33 of 61 surviving children, from a
series of 107 consecutive live-born cases with nonimmune hydrops fetalis. The
majority had a normal outcome. Three had a (simultaneous) serious underlying
disease (e.g. fetal herpes infection) and had either severe psychomotor
retardation or blindness. Two showed clumsiness and were considered to have minor
neurological dysfunction. We conclude that survivors, especially those with
transient benign intrauterine conditions, such as lymphatic aetiology have no
additional risk to their psychomotor development.
PMID- 10688516
TI - Folic acid supplements are more effective than increased dietary folate intake in
elevating serum folate levels.
AB - In 1992, recommendations were disseminated aimed at reducing the incidence of
neural tube defects. Women were advised to increase consumption of folic acid
supplements and dietary folates during the periconceptional period and a major
integrated national campaign was launched to help achieve this. In this study we
found that only one-quarter of the women with an uncomplicated obstetric history
and 51% with a complicated obstetric history took supplements for the recommended
time period. Dietary modification was extremely unusual. Serum analysis
demonstrated that intake of folic acid supplements provides a greater elevation
in serum folate levels than dietary food intake, suggesting dietary manipulation
is an ineffective strategy and that efforts would be better focused on increasing
supplement intake at a clinically important time. More effective education
strategies are required, and since approximately one-third of pregnancies are
unplanned, fortification of foods with folic acid is warranted.
PMID- 10688517
TI - Effects of growth hormone treatment in a woman with growth hormone deficiency.
PMID- 10688518
TI - Vulvar syringoma showing progesterone receptor positivity.
PMID- 10688519
TI - Transvaginal ultrasonography and endometrial histology in peri- and
postmenopausal women on hormone replacement therapy.
PMID- 10688520
TI - Prophylactic administration of clindamycin 2% vaginal cream to reduce the
incidence of spontaneous preterm birth in women with an increased risk: a
randomised placebo-controlled double-blind trial.
PMID- 10688521
TI - Maternal serum alphafetoprotein screening for open neural tube defects: revised
statistical parameters.
PMID- 10688522
TI - Review and assessment of selection criteria used when booking pregnant women at
different places of birth.
PMID- 10688523
TI - Risk factors for rape, physical assault, and posttraumatic stress disorder in
women: examination of differential multivariate relationships.
AB - The National Women's Study, a 2-year, three-wave longitudinal investigation,
employed a national probability sample of 3,006 adult women to: (a) identify
separate risk factors for rape and physical assault, and (b) identify separate
risk factors associated with post-rape posttraumatic stress disorder (PTSD) and
post-physical assault PTSD. This investigation differed from previous studies in
that it prospectively examined risk factors at the multivariate, as opposed to
univariate level. Overall, past victimization, young age, and a diagnosis of
active PTSD increased women's risk of being raped. By contrast, past
victimization, minority ethnic status, active depression, and drug use were
associated with increased risk of being physically assaulted. Risk factors for
PTSD following rape included a history of depression, alcohol abuse, or
experienced injury during the rape. However, risk factors for PTSD following
physical assault included only a history of depression and lower education.
PMID- 10688524
TI - Does anxiety mitigate the behavioral expression of severe conduct disorder in
delinquent youths?
AB - The purpose of this article is to examine the purported attenuating effects of
comorbid anxiety on conduct disturbance in a sample of youths exhibiting severe
Conduct Disorder (CD). Further, we examined the differential expression of CD and
comorbid anxiety in male and female youths. Seventy-nine incarcerated youths
between the ages of 12 and 19 were interviewed using the Diagnostic Interview
Schedule for Children. Youths were identified who exhibited CD and CD plus an
anxiety disorder. In contrast to previous findings with younger, less seriously
disturbed male subjects, no overall differences were found between CD anxious and
CD nonanxious youths in terms of age of first offense and overall number and
severity of delinquent acts. Moreover, no differences were found between males
and females, and gender did not moderate the effects of comorbidity anxiety on
outcome measures. Findings suggest purported mitigating effects of anxiety on
conduct disturbance may be attenuated in severe forms of CD and support the
notion that comorbidity across internalizing and externalizing domains of child
and adolescent psychopathology may differentially impact clinical presentation of
disordered behavior depending on the severity of externalizing behavioral
disturbance.
PMID- 10688525
TI - The efficacy of habituation in decreasing subjective distress among high anxiety
sensitive college students.
AB - While there is mounting evidence that the concept of anxiety sensitivity (AS) is
linked to the expression of anxiety (specifically, panic), there has been little
research comparing the efficacy of interoceptive exposure alone with
interoceptive exposure coupled with cognitive restructuring among high AS
participants. The present investigation addressed this issue in a sample of high
anxiety-sensitive college students (scores above 29 on the Anxiety Sensitivity
Index). Participants were randomly assigned to receive either five consecutive
trials of voluntary hyperventilation or five consecutive trials of
hyperventilation with cognitive restructuring instructions. It was expected that
while repeated hyperventilation would be associated with a significant reduction
in self-reported anxiety, catastrophic cognitions, and somatic sensations across
trials, the greatest reduction in symptoms would occur with the addition of
cognitive restructuring. These predictions were partially supported. As expected,
high AS participants evidenced significant decreases in anxiety symptoms when
habituation was accompanied by cognitive restructuring. Contrary to predictions,
however, interoceptive exposure alone was not effective in reducing anxious
symptoms. These results suggest that brief habituation alone may not be an
effective strategy for high AS participants and are discussed as providing
further support for a cognitive model of anxiety.
PMID- 10688526
TI - The effects of time pressure on arithmetic performance.
AB - It has recently been demonstrated that highly math-anxious individuals may be
less proficient on arithmetic tasks, particularly those that involve complex
problems. The processing efficiency theory postulates that in highly anxious
individuals, working memory resources are consumed by "worry," thereby leaving
fewer resources available for task completion. Although there is some empirical
support for this theory, the precise nature of this worry has yet to be
identified. We tested the hypothesis that time pressure may be one component
contributing to worry, and subsequent performance deficits characteristic of high
math-anxious individuals. Thirty participants completed arithmetic problems of
varying complexity in both a timed and untimed condition. Although the timing
manipulation negatively affected arithmetic performance in both high and low
anxious participants, anxiety groups were not differentially affected.
Researchers may therefore have to look to other variables to explain the nature
of worrisome thoughts that are theorized to disrupt the performance of anxious
individuals.
PMID- 10688527
TI - Levels of anxiety sensitivity in relation to repressive and self-deceptive coping
styles.
AB - Levels of anxiety sensitivity (AS) were investigated in relation to self
deception and repression in 296 university students. It was hypothesized that a
low level of AS, rather than constituting "normal" functioning, would be
associated with more general response biases. Scores on the Anxiety Sensitivity
Index (ASI; Peterson & Reiss, 1987, 1992) were negatively and significantly
correlated with measures of self-deception and denial. Individuals with low AS
were significantly more likely to meet an operational definition of repression
(i.e., low anxiety and high defensiveness), compared to mid AS and high AS
groups. When confronted with a hypothetical health problem, individuals with low
AS were less likely to choose a task-oriented response and more likely to choose
denial and self-deceptive responses, compared to the other groups. These findings
support the observations of Shostak and Peterson (1990) that low AS represents an
extreme group that may not be indicative of normal functioning.
PMID- 10688528
TI - The power of suggestion: comment on EMDR and mesmerism: a comparative historical
analysis.
AB - This response to McNally challenges the notion that scientific controversy should
be waged with smear tactics. McNally's anti-EMDR conclusions are contested as
premature and based on red herrings, selective neglect of the literature, and
erroneous application of scientific principles. The importance of treatment
fidelity is highlighted as a way of distinguishing between EMDR studies of widely
varying quality.
PMID- 10688529
TI - Altered electrophoretic migration of polycyclic aromatic hydrocarbon and styrene
oxide adducts at adenine N(6) correlates with adduct-induced structural disorder.
AB - Site-specific bay region benzo[a]pyrene (7R,8S,9R,10S)-N(6)-[10-(7,8, 9,10
tetrahydro-7,8,9-trihydroxybenzo[a]pyrenyl)]-2'-deoxyadeno syl, (7S,8R,9S,10R)
N(6)-[10-(7,8,9,10-tetrahydro-7,8, 9-trihydroxybenzo[a]pyrenyl)]-2'
deoxyadenosyl, (7S,8R,9R, 10S)-N(6)-[10-(7,8,9,10-tetrahydro-7,8, 9
trihydroxybenzo[a]pyrenyl)]-2'-deoxyadenosyl, and (7R,8S,9S, 10R)-N(6)-[10
(7,8,9,10-tetrahydro-7,8, 9-trihydroxybenzo[a]pyrenyl)]-2'-deoxyadenosyl adducts,
bay region benz[a]anthracene (1R,2S,3R,4S)-N(6)-[1-(1,2,3,4-tetrahydro-2,3, 4
trihydroxybenz[a]anthracenyl)]-2'-deoxyadenosyl and (1S,2R,3S, 4R)-N(6)-[1
(1,2,3,4-tetrahydro-2,3, 4-trihydroxybenz[a]anthracenyl)]-2'-deoxyadenosyl
adducts, non-bay region benz[a]anthracenyl (8S,9R,10S,11R)-N(6)-[11-(8,9,10, 11
tetrahydro-8,9,10-trihydroxybenz[a]anthracenyl)]-2'-de oxyadenosyl and
(8R,9S,10R,11S)-N(6)-[11-(8,9,10,11-tetrahydro-8,9, 10
trihydroxybenz[a]anthracenyl)]-2'-deoxyadenosyl adducts, and the R- and S-adducts
of styrene oxide were located in the ras61 oligodeoxynucleotide and examined with
respect to electrophoretic mobility. The results were compared to NMR structural
data, and to site-specific mutagenesis data and in vitro DNA replication assays
for the same adducts. There was a correlation between adducts having lower
electrophoretic mobility and greater disorder at the adduct site as monitored by
NMR. The disorder combined with the lower electrophoretic mobilities suggested
that these adducts induced flexible hinge joints in the DNA rather than static
bending. Usually, these were adenine N(6) adducts having S-stereochemistry at the
benzylic carbon. The results also revealed a possible role for the bay region
ring in stabilizing adenyl N(6) benz[a]anthracene adducts with respect to hinging
at the adduct site. On the other hand, there was not a simple relationship
between altered electrophoretic mobility and mutagenesis or DNA replication.
PMID- 10688530
TI - In vitro DNA deamination by alpha-nitrosaminoaldehydes determined by GC/MS-SIM
quantitation.
AB - The deamination of DNA bases by three alpha-nitrosaminoaldehydes,
butylethanalnitrosamine, methylethanalnitrosamine, and N-nitroso-2
hydroxymorpholine (NHMOR), the direct metabolite of potent animal carcinogen N
nitrosodiethanolamine, was demonstrated by a set of in vitro experiments. The
deamination of guanine, adenine, and cytosine bases in nucleotides,
oligonucleotides, and calf thymus DNA gave xanthine, hypoxanthine, and uracil,
respectively. The order of relative reactivities of the bases was as listed
above. Deamination of cytosine to uracil was detected by the reaction of (32)P
labeled oligonucleotide ([5'-(32)P]CGAT) followed by enzymatic hydrolysis.
Quantitative analysis of deamination of guanine and adenine in calf thymus DNA
was performed by a gas chromatography/mass spectrometry-selected ion monitoring
method. Both the extent and the rate of the deamination reactions which occur by
transnitrosation from the alpha-nitrosaminoaldehyde to the base were determined
for formation of xanthine and hypoxanthine. The deamination of guanine by NHMOR
remained significant at low substrate levels.
PMID- 10688531
TI - Isocyanate-specific hemoglobin adduct in rats exposed to 4, 4'-methylenediphenyl
diisocyanate.
AB - 4,4'-Methylenediphenyl diisocyanate (MDI) is the most important of the
isocyanates used as intermediates in the chemical industry. Among the main types
of damage after exposure to low levels of MDI are lung sensitization and asthma.
Protein adducts of MDI might be involved in the etiology of sensitization
reactions. It is therefore necessary to have sensitive and specific methods for
monitoring the isocyanate exposure of workers. To date, urine metabolites or
protein adducts have been used as biomarkers in workers exposed to MDI. However,
with these methods it is not possible to determine if the biomarkers result from
exposure to MDI or to the parent aromatic amine 4,4'-methylenedianiline (MDA).
This work presents a procedure for quantitating isocyanate-specific hemoglobin
adducts. Blood proteins are used as markers of exposure and possibly as markers
of dose size for the modifications of macromolecules in the target organs where
the disease develops. For the quantitation of hemoglobin adducts, N(1)-[4-(4
isocyanatobenzyl)phenyl]acetamide (AcMDI) was reacted with the tripeptide valyl
glycyl-glycine and with valine yielding N-[4-(4
acetylaminobenzyl)phenyl]carbamoyl]valyl-glycyl-glycine and N-[4-[4
(acetylaminobenzyl)phenyl]carbamoyl]valine, respectively. N-[4-[4-(Acetylamino
3,5-dideuteriobenzyl)-2, 6-dideuteriophenyl]carbamoyl]valine was synthesized from
valine, as was N(1)-[4-(4-isocyanato-3,5-dideuteriobenzyl)-2, 6
dideuteriophenyl]acetamide, for use as an internal standard. These adducts were
cleaved in 2 M HCl to yield the corresponding hydantoins, 3-[4-(4
aminobenzyl)phenyl]-5-isopropyl-1, 3-imidazoline-2,4-dione (MDA-Val-Hyd) and 3-[4
(4-amino-3, 5-dideuteriobenzyl)-2,6-dideuteriophenyl]-5-isopropyl-1, 3
imidazoline-2,4-dione, respectively. In globin of rats exposed to MDI, MDA-Val
Hyd could be found in a dose-dependent manner. The adduct was identified by
HPLC/MS/MS and quantified by GC/MS after derivatization with heptafluorobutyric
anhydride. The amount of MDA-Val-Hyd found after acid hydrolysis of globin at 100
degrees C is about 12 times larger than the sum of N-acetyl-4, 4'
methylenedianiline (AcMDA) and MDA obtained from mild base hydrolysis of
hemoglobin. The MDA-Val-Hyd is an isocyanate-specific adduct. MDA and AcMDA
released after mild base hydrolyses result most likely from a sulfinamide adduct
which is a typical adduct of arylamines. According to these results, higher
amounts of isocyanate adducts than arylamine adducts should be expected in
workers exposed to isocyanates.
PMID- 10688532
TI - Synthesis of oligonucleotides containing the alkali-labile pyrimidopurinone
adduct, M(1)G.
AB - An improved method for the synthesis of oligodeoxyribonucleotides containing the
endogenous adduct, pyrimido[1,2-a]purin-10(3H)-one (M(1)G), is reported. The key
features of the methodology include improved synthesis of the deoxynucleoside of
M(1)G by transribosylation with deoxycytidine catalyzed by nucleoside 2'
deoxyribosyltransferase and the use of commercially available 4-tert
butylphenoxyacetyl protecting groups for normal nucleotides. Facile deprotection
and removal of the M(1)G-containing oligomers from the solid support were
achieved by treatment with a solution of potassium carbonate in methanol. NMR
studies were performed to determine the stability of the oligonucleotides at
different pHs.
PMID- 10688533
TI - Sulfinamide formation following peroxidatic metabolism of N-acetylbenzidine.
AB - Arylamine-hemoglobin conjugates identified as sulfinamides are considered
dosimeters for the bioavailability of metabolically formed N-oxidation products.
This report considers peroxidation as an alternative pathway for aromatic amine
metabolism and examines horseradish peroxidase metabolism of N-acetylbenzidine
(ABZ) in the presence of glutathione. When 0.06 mM [(3)H]ABZ was incubated with 1
mM glutathione, a decrease in the total extent of metabolism was observed along
with detection of a new metabolite (ABZ-SG), representing 12% of the total
radioactivity. Optimum ABZ-SG formation occurred at 0.3 mM glutathione with
higher concentrations (10 mM) being inhibitory. In the absence of glutathione, a
molar ratio of H(2)O(2) to ABZ of 1:1 resulted in complete metabolism of ABZ.
This ratio increased to >2:1 in the presence of 0.3 mM glutathione. N-Oxidation
products of ABZ metabolism, such as N'-hydroxy-N-acetylbenzidine, were not
detected using a variety of incubation conditions. ABZ-SG was sensitive to gamma
glutamyltranspeptidase, and completely hydrolyzed by 0.1 N HC1 or 0.1 N NaOH in
10 min at room temperature. ABZ-SG was identified by mass spectrometry and NMR to
be N'-(glutathion-S-yl)-N-acetylbenzidine S-oxide. ABZ-SG formation, but not
total ABZ metabolism, was prevented by 0.3 mM NaN(3), 50 mM DMPO, 1.0 mM
thiourea, and 1.0 mM histidine. Cyanide (50 mM) and ascorbic acid (0.1 mM)
completely inhibited ABZ metabolism. The lack of effect of 50 mM mannitol and 2
microgram of superoxide dismutase suggests that neither hydroxyl radical nor
superoxide is involved in the reaction. Studies also indicated that molecular
oxygen is not a source of the sulfinamide oxygen. Formation of an ABZ sulfinamide
conjugate with hemoglobin was demonstrated. The proposed mechanism for
sulfinamide formation, involving two consecutive one-electron oxidations with
subsequent rearrangement to a sulfur-stabilized nitrenium ion, suggests that
oxygen may be derived from water. The results demonstrate that while arylamine
hemoglobin conjugates serve as useful biomarkers of exposure, their mechanism of
formation may be complex, perhaps involving peroxidation as in the case of N'
(glutathion-S-yl)-N-acetylbenzidine S-oxide.
PMID- 10688534
TI - The sensitivity of carboxyl-terminal methionines in calmodulin isoforms to
oxidation by H(2)O(2) modulates the ability to activate the plasma membrane Ca
ATPase.
AB - The oxidative modification of methionines within the primary sequence of
calmodulin (CaM) results in an inability to activate the PM-Ca-ATPase fully, and
may contribute to alterations in calcium homeostasis under conditions of
oxidative stress. To identify differences in the sensitivities of CaM isoforms to
oxidative modification, we have compared the function and patterns of oxidative
modification resulting from the exposure of CaM isolated from bovine testes and
wheat germ to H(2)O(2). In comparison to CaM isolated from wheat germ, vertebrate
CaM is functionally resistant to oxidant-induced loss of function. The decreased
functional sensitivity of vertebrate CaM correlates with a 75 +/- 3% reduction in
the rate of oxidative modification of a methionine near the carboxyl terminus
(i.e., Met(144) or Met(145)). The extent of oxidative modification to other
methionines in these CaM isoforms is similar. These results suggest that the
sensitivity of Met(144) or Met(145) to oxidation modulates the ability of CaM to
activate the PM-Ca-ATPase. Consistent with this interpretation, a CaM mutant in
which glutamines were substituted for Met(144) and Met(145) fully activates the
PM-Ca-ATPase irrespective of the oxidative modification of the other seven
methionines to their corresponding methionine sulfoxides. The extent of oxidative
modification to individual methionines in vertebrate CaM by H(2)O(2) correlates
with the time-averaged surface accessibility of individual sulfurs calculated
from molecular dynamics simulations. Thus, the sensitivity of individual
methionines to oxidative modification is directly related to the solvent
accessibility. These results indicate that sequence differences between
vertebrate and plant CaM alter the sensitivity of methionines near the carboxyl
terminus to oxidative modification because of alterations in their solvent
accessibility. We suggest that these sequence differences between CaM isoforms
have a regulatory role in modulating the functional sensitivity of CaM to
conditions of oxidative stress.
PMID- 10688535
TI - Stress- and growth-related gene expression are independent of chemical-induced
prostaglandin E(2) synthesis in renal epithelial cells.
AB - Cellular stress can initiate prostaglandin (PG) biosynthesis which, through
changes in gene expression, can modulate cellular functions, including cell
growth. PGA(2), a metabolite of PGE(2), induces the expression of stress response
genes, including gadd153 and hsp70, in HeLa cells and human diploid fibroblasts.
PGs, gadd153, and hsp70 expression are also influenced by the cellular redox
status. Polyphenolic glutathione conjugates retain the ability to redox cycle,
with the concomitant generation of reactive oxygen species. One such conjugate,
2,3,5-tris(glutathion-S-yl)hydroquinone (TGHQ), is a potent nephrotoxic and
nephrocarcinogenic metabolite of the nephrocarcinogen, hydroquinone. We therefore
investigated the effects of TGHQ on PGE(2) synthesis and gene expression in a
renal proximal tubular epithelial cell line (LLC-PK(1)). TGHQ (200 microM, 2 h)
increases PGE(2) synthesis (2-3-fold) in LLC-PK(1) cells with only minor (5%)
reductions in cell viability. This response is toxicant-specific, since another
proximal tubular toxicant, S-(1, 2-dichlorovinyl)-L-cysteine (DCVC), stimulates
PGE(2) synthesis only after massive (68%) reductions in cell viability.
Consistent with the ability of TGHQ to generate an oxidative stress, both
deferoxamine mesylate and catalase protect LLC-PK(1) cells from TGHQ-mediated
cytotoxicity. Only catalase, however, completely blocks TGHQ-mediated PGE(2)
synthesis, implying a major role for hydrogen peroxide in this response. TGHQ
induces the early (60 min) expression of gadd153 and hsp70. However, while
inhibition of cyclooxygenase with aspirin prevents TGHQ-induced PGE(2) synthesis,
it does not affect TGHQ-mediated induction of gadd153 or hsp70 expression. In
contrast, a stable PGE(2) analogue, 11-deoxy-16, 16-dimethyl-PGE(2) (DDM-PGE(2)),
which protects LLC-PK(1) cells against TGHQ-mediated cytotoxicity, modestly
elevates the levels of gadd153 and hsp70 expression. In addition, catalase and,
to a lesser extent, deferoxamine mesylate block TGHQ-induced gene expression.
Therefore, although TGHQ-induced generation of reactive oxygen species is
required for PGE(2) synthesis and stress gene expression, acute TGHQ-mediated
increases in gadd153 and hsp70 mRNA levels are independent of PGE(2) synthesis.
PMID- 10688536
TI - Interleukin-8 levels in human lung epithelial cells are increased in response to
coal fly ash and vary with the bioavailability of iron, as a function of particle
size and source of coal.
AB - Particulate air pollution contains iron, and some of the pathological effects
after inhalation may be due to radical species produced by iron-catalyzed
reactions. We tested the hypothesis that iron present in coal fly ash (CFA) could
induce the expression and synthesis of the inflammatory cytokine interleukin-8
(IL-8). CFA, containing as much as 14% iron, was used as a model combustion
source particle. Three coal types were used to generate three size fractions
enriched in particles [submicron (<1 micrometer), fine (<2.5 micrometer), or
coarse (2.5-10 micrometer]), as well as the fraction of >10 micrometer. Treatment
of human lung epithelial (A549) cells for 4 h with CFA from Utah enriched in <1
micrometer particles (20 microgram/cm(2)) resulted in a 2.6-fold increase in mRNA
levels for IL-8. IL-8 levels were increased in the medium by as much as 8-fold
when cells were treated with the fraction enriched in the smallest size Utah CFA
for 24 h. IL-8 production was completely inhibited when the CFA was pretreated
with the metal chelator desferrioxamine B, suggesting that a transition metal was
responsible for the induction, probably iron. Treatment with a soluble form of
iron, ferric ammonium citrate (FAC), mimicked the IL-8 level increase observed
with CFA. There was a direct relationship, above a threshold level of
bioavailable iron, between the levels of IL-8 and bioavailable iron in A549 cells
treated with CFA or FAC. Further, the relationship between IL-8 and bioavailable
iron for CFA was indistinguishable from that for FAC. These results strongly
suggest that iron can induce IL-8 in A549 cells and that iron was the likely
component of CFA that induced IL-8. CFA-induced IL-8 production was inhibited by
tetramethylthiourea or dimethyl sulfoxide, suggesting that radical species were
involved in the induction. These results demonstrate that iron present in CFA may
be responsible for production and release of inflammatory mediators by the lung
epithelium through generation of radical species and suggest that iron may
contribute to the exacerbation of respiratory problems by particulate air
pollution.
PMID- 10688537
TI - Rat liver cytosol catalyzes a reaction involving activated N-nitrosodimethylamine
and a carbohydrate from the pentose phosphate pathway.
AB - N-Nitrosodimethylamine is a liver toxin and mutagen following activation by
cytochrome P450. The role of the cytosol in N-nitrosodimethylamine metabolism is
not well understood. The effect of cytosol on N-nitrosodimethylamine metabolism
was investigated using microsomes and cytosol from rat liver in in vitro
reactions with N-nitrosodimethylamine and an NADPH generating system. Studies in
which [(14)C]-N-nitrosodimethylamine and calf thymus DNA were used indicated that
the addition of cytosol to the microsomal reaction mixture resulted in >200%
enhancement of the radioactivity associated with DNA after the DNA was isolated
from the reaction mixture by phenol extraction followed by ethanol precipitation.
This stimulatory effect was associated with a cytosolic protein and was found to
be dependent on both the microsomes and the carbohydrate used in the glucose-6
phosphate dehydrogenase system for the generation of NADPH. The carbohydrate
requirement was found to be specific for intermediates of the pentose phosphate
pathway, and maximum stimulation occurred with ribulose 5-phosphate. Most of the
counts from [(14)C]-N-nitrosodimethylamine which were isolated with DNA after the
addition of cytosol to reaction mixtures were not covalently bound to the DNA.
HPLC analysis identified four radiolabeled metabolites derived from [(14)C]-N
nitrosodimethylamine following the in vitro incubations. One of the four products
was formed only when both cytosol and ribulose 5-phosphate were added to the
enzymatic incubations. This product also formed from [(14)C]-alpha-acetoxy
nitrosodimethylamine in the absence of microsomes, only when cytosol and ribulose
5-phosphate were added to the reaction mixtures. Thus, these data demonstrate
that an enzyme in the cytosol catalyzes a reaction involving a metabolite of N
nitrosodimethylamine (which is formed following cytochrome P450-mediated
activation) and a carbohydrate related to the pentose phosphate pathway. A
similar reaction also occurs with N-diethylnitrosamine but not with N
dipropylnitrosamine or N-dibutylnitrosamine.
PMID- 10688538
TI - Advances in managing chronic disease. Research, performance measurement, and
quality improvement are key.
PMID- 10688539
TI - Patients as partners in managing chronic disease. Partnership is a prerequisite
for effective and efficient health care.
PMID- 10688540
TI - Depression management clinics in general practice? Some aspects lend themselves
to the mini-clinic approach.
PMID- 10688541
TI - Building evidence on chronic disease in old age. Standardised assessments and
databases offer one way of building the evidence.
PMID- 10688542
TI - Disease management: has it a future? It has a compelling logic, but needs to be
tested in practice.
PMID- 10688543
TI - British tobacco company denies "orchestrating smuggling".
PMID- 10688544
TI - Paediatricians "close to despair" over child protection laws
PMID- 10688545
TI - UK home secretary faces new problems over pinochet
PMID- 10688546
TI - Screening changes recommended for osteoporosis and diabetes
PMID- 10688547
TI - In brief
PMID- 10688548
TI - Albumin industry launches global promotion.
PMID- 10688549
TI - Britain's health league table attacked.
PMID- 10688550
TI - Hospital infection rates in England out of control.
PMID- 10688551
TI - Donors and relatives must place no conditions on organ use.
PMID- 10688552
TI - Gynaecologist cleared in hysterectomy case.
PMID- 10688553
TI - Spain's home healthcare programme goes nationwide.
PMID- 10688556
TI - Cirrhosis may be amenable to telomerase treatment
PMID- 10688554
TI - British Columbia blocks tobacco move.
PMID- 10688557
TI - Painkillers "may need to be sex specific".
PMID- 10688558
TI - Systematic reviews and meta-analyses on treatment of asthma: critical evaluation.
AB - OBJECTIVE: To evaluate the clinical, methodological, and reporting aspects of
systematic reviews and meta-analyses on the treatment of asthma and to compare
those published by the Cochrane Collaboration with those published in paper based
journals. DESIGN: Analysis of studies identified from Medline, CINAHL,
HealthSTAR, EMBASE, Cochrane Library, personal collections, and reference lists.
STUDIES: Articles describing a systematic review or a meta-analysis of the
treatment of asthma that were published as a full report, in any language or
format, in a peer reviewed journal or the Cochrane Library. MAIN OUTCOME
MEASURES: General characteristics of studies reviewed and methodological
characteristics (sources of articles; language restrictions; format, design, and
publication status of studies included; type of data synthesis; and
methodological quality). RESULTS: 50 systematic reviews and meta-analyses were
included. More than half were published in the past two years. Twelve reviews
were published in the Cochrane Library and 38 were published in 22 peer reviewed
journals. Forced expiratory volume in one second was the most frequently used
outcome, but few reviews evaluated the effect of treatment on costs or patient
preferences. Forty reviews were judged to have serious or extensive flaws. All
six reviews associated with industry were in this group. Seven of the 10 most
rigorous reviews were published in the Cochrane Library. CONCLUSIONS: Most
reviews published in peer reviewed journals or funded by industry have serious
methodological flaws that limit their value to guide decisions. Cochrane reviews
are more rigorous and better reported than those published in peer reviewed
journals.
PMID- 10688559
TI - Qualitative study of interpretation of reassurance among patients attending
rheumatology clinics: "just a touch of arthritis, doctor?".
AB - OBJECTIVES: To examine commonly used methods of reassurance by clinicians and
explore their effect on patients. DESIGN: Qualitative study of tape recordings of
in-depth, semistructured interviews with patients before and after consultation
and of their consultations with doctors. SETTING: NHS specialist rheumatology
clinics in two large British cities. PARTICIPANTS: 35 patients selected by
consultant rheumatologists from general practitioner referral letters (28 women,
7 men; 24 with inflammatory arthropathies, 11 other rheumatological complaints).
MAIN OUTCOME MEASURES: Patients' perceptions of reassurance. RESULTS: Reassurance
was an important part of consultations, whether the diagnosis was clear or
uncertain. Clinicians tried to reduce anxiety by emphasising the mildness, early
stage, or non-seriousness of the disorder and the likelihood that patients would
recover. Patients interpreted reassurance in the context of their own views and
perceptions. Doctors' emphasis on the mildness or earliness of the condition
raised the spectre of future pain and disability rather than providing
reassurance. Patients who felt that their problems were properly acknowledged
felt more reassured. CONCLUSIONS: Typical patterns of reassurance were not
successful because of the differences in perspective of patients and doctors. A
key to successful reassurance seemed to be the doctor's ability to acknowledge
patients' perspectives of their difficulties.
PMID- 10688560
TI - Open access follow up for inflammatory bowel disease: pragmatic randomised trial
and cost effectiveness study.
AB - OBJECTIVE: To evaluate whether follow up of patients with inflammatory bowel
disease is better through open access than by routine booked appointments.
DESIGN: Pragmatic randomised controlled trial. SETTING: Two district general
hospitals in Swansea and Neath, Wales. PARTICIPANTS: 180 adults (78 with Crohn's
disease, 77 ulcerative or indeterminate colitis, 25 ulcerative or idiopathic
proctitis) recruited from outpatient clinics during October 1995 to November
1996. INTERVENTION: Open access follow up according to patient need. MAIN OUTCOME
MEASURES: Generic (SF-36) and disease specific (UK inflammatory bowel disease
questionnaire UKIBDQ) quality of life, number of primary and secondary care
contacts, total resource use, and views of patients and general practitioners.
RESULTS: There were no differences in generic or disease specific quality of
life. Open access patients had fewer day visits (0.21 v 0. 42, P<0.05) and fewer
outpatient visits ( 4.12 v 4.64, P<0.01), but some patients had difficulty
obtaining an urgent appointment. There were no significant differences in
specific investigations undertaken, inpatient days, general practitioner surgery
or home visits, drugs prescribed, or total patient borne costs. Mean total cost
in secondary care was lower for open access patients (P<0.05), but when primary
care and patient borne costs were added there were no significant differences in
total costs to the NHS or to society. General practitioners and patients
preferred open access. CONCLUSIONS: Open access follow up delivers the same
quality of care as routine outpatient care and is preferred by patients and
general practitioners. It uses fewer resources in secondary care but total
resource use is similar. Better methods of ensuring urgent access to outpatient
clinics are needed.
PMID- 10688561
TI - Five year follow up of a randomised controlled trial of a stroke rehabilitation
unit.
PMID- 10688562
TI - Machiavelli on clinical management
PMID- 10688563
TI - Randomised trial of monitoring, feedback, and management of care by telephone to
improve treatment of depression in primary care.
AB - OBJECTIVE: To test the effectiveness of two programmes to improve the treatment
of acute depression in primary care. DESIGN: Randomised trial. SETTING: Primary
care clinics in Seattle. PATIENTS: 613 patients starting antidepressant
treatment. INTERVENTION: Patients were randomly assigned to continued usual care
or one of two interventions: feedback only and feedback plus care management.
Feedback only comprised feedback and algorithm based recommendations to doctors
on the basis of data from computerised records of pharmacy and visits. Feedback
plus care management included systematic follow up by telephone, sophisticated
treatment recommendations, and practice support by a care manager. MAIN OUTCOME
MEASURES: Blinded interviews by telephone 3 and 6 months after the initial
prescription included a 20 item depression scale from the Hopkins symptom
checklist and the structured clinical interview for the current DSM-IV depression
module. Visits, antidepressant prescriptions, and overall use of health care were
assessed from computerised records. RESULTS: Compared with usual care, feedback
only had no significant effect on treatment received or patient outcomes.
Patients receiving feedback plus care management had a higher probability of both
receiving at least moderate doses of antidepressants (odds ratio 1.99, 95%
confidence interval 1.23 to 3.22) and a 50% improvement in depression scores on
the symptom checklist (2.22, 1.31 to 3.75), lower mean depression scores on the
symptom checklist at follow up, and a lower probability of major depression at
follow up (0.46, 0.24 to 0.86). The incremental cost of feedback plus care
management was about $80 ( pound50) per patient. CONCLUSIONS: Monitoring and
feedback to doctors yielded no significant benefits for patients in primary care
starting antidepressant treatment. A programme of systematic follow up and care
management by telephone, however, significantly improved outcomes at modest cost.
PMID- 10688564
TI - Management of chronic uveitis.
PMID- 10688565
TI - ABC of heart failure. Acute and chronic management strategies.
PMID- 10688566
TI - Disease management in the American market.
PMID- 10688567
TI - Commercial partnerships in chronic disease management: proceeding with caution.
PMID- 10688570
TI - Fascinating rhythm
PMID- 10688568
TI - The role of patient care teams in chronic disease management.
PMID- 10688569
TI - Management of chronic disease by practitioners and patients: are we teaching the
wrong things?
PMID- 10688571
TI - Management of hypertension. Ideal body weight is not realistic goal for lifestyle
intervention.
PMID- 10688572
TI - Greenwich asthma study. Study's conclusions are premature.
PMID- 10688573
TI - beta Blockade after myocardial infarction. Beta blockers have key role in
reducing morbidity and mortality after infarction.
PMID- 10688574
TI - Health professionals do not understand mathematical models.
PMID- 10688575
TI - Inequalities in health continue to grow despite government's pledges.
PMID- 10688577
TI - PM will address GPs' conference
PMID- 10688576
TI - Obituaries
PMID- 10688578
TI - Incontinence
PMID- 10688579
TI - Schizophrenia: concepts and clinical management
PMID- 10688580
TI - Handbook for mortals: guidance for people facing serious illness
PMID- 10688581
TI - Epilepsy: problem solving in clinical practice
PMID- 10688582
TI - Let the children do the talking
PMID- 10688583
TI - Disease management
PMID- 10688584
TI - Facing the challenges of long term care
PMID- 10688585
TI - And how is sir today?
PMID- 10688587
TI - Systematic reviews and meta-analyses are often flawed
PMID- 10688586
TI - Management and preferences
PMID- 10688589
TI - Open access follow up can work in chronic bowel disease
PMID- 10688588
TI - Doctors' reassurances are often ineffective
PMID- 10688590
TI - Stroke units seem to have a long term impact on patients' outcomes
PMID- 10688591
TI - Monitoring, feedback, and care management improve treatment of depression
PMID- 10688592
TI - Doctors and patients are taught the wrong skills for managing chronic disease
PMID- 10688593
TI - Histamine H(3)-receptors: a new frontier in myocardial ischemia.
AB - In protracted myocardial ischemia, sympathetic nerve endings undergo ATP
depletion, hypoxia and pH(i) reduction. Consequently, norepinephrine (NE)
accumulates in the axoplasm, because it is no longer stored in synaptic vesicles,
and intraneuronal Na(+) concentration increases, as the Na(+)/H(+) exchanger
(NHE) is activated. This forces the reversal of the Na(+)- and Cl(-)-dependent NE
transporter, triggering a massive carrier-mediated release of NE and thus,
arrhythmias. Indeed, NE overflow in myocardial ischemia directly correlates with
the severity of arrhythmias. Histamine H(3)-receptors (H(3)R) have been
identified as inhibitory heteroreceptors in adrenergic nerve endings of the
heart. In addition to inhibiting NE exocytosis from sympathetic nerve endings,
selective H(3)R agonists attenuate carrier-mediated release of NE in both animal
and human models of protracted myocardial ischemia. Whereas H(3)R-mediated
attenuation of exocytotic NE release involves an inhibition of N-type Ca(2+)
channels, H(3)R-mediated reduction of carrier-mediated NE release is associated
with diminished NHE activity. In addition to inhibiting NE release, H(3)R
stimulation significantly attenuates the incidence and duration of ventricular
fibrillation. Although other presynaptic receptors also modulate NE release from
sympathetic nerve endings, H(3)R stimulation reduces both exocytotic and carrier
mediated NE release, whereas alpha(2)-adrenoceptor agonists attenuate NE
exocytosis but enhance carrier-mediated NE release. Furthermore, unlike adenosine
A(1)-receptors, whose activation reduces both exocytotic and carrier-mediated NE
release, H(3)R stimulation is devoid of negative chronotropic and dromotropic
effects (i.e., sinoatrial and atrioventricular nodal functions are unaffected).
Because excess NE release can trigger severe arrhythmias and sudden cardiac
death, negative modulation of NE release by H(3)R agonists may offer a novel
therapeutic approach to myocardial ischemia.
PMID- 10688594
TI - Anti-phencyclidine monoclonal antibodies provide long-term reductions in brain
phencyclidine concentrations during chronic phencyclidine administration in rats.
AB - These studies examined the hypothesis that a single large dose of monoclonal anti
phencyclidine (PCP) antibody could provide long-term reductions in brain PCP
concentrations despite continuous PCP administration. PCP (18 mg/kg/day, s.c.)
was infused to steady-state (24 h) and then a mole-equivalent dose of a short
acting anti-PCP antigen-binding fragment (Fab) or a long-acting anti-PCP IgG was
administered i.v. The PCP infusion continued for up to 27 days, even though the
binding capacity of the single dose of antibody used should have been saturated
within the first day. At selected time points after antibody administration,
brain, testis, and serum PCP concentrations were measured. Serum PCP
concentrations rapidly increased approximately 100- and 300-fold after Fab or IgG
administration, respectively. Based on the antibody-bound PCP concentrations in
serum, the functional elimination half-life (t(1/2lambdaZ)) values for PCP-Fab
and PCP-IgG complexes were 9.4 h and 15.4 days, respectively. Fab and IgG
administration produced a complete removal of PCP from the brain within 15 min.
Although brain PCP concentrations were significantly decreased for only 4 h in
Fab-treated animals, IgG administration resulted in significant decreases in
brain PCP concentrations lasting for at least 27 days. In contrast, testis PCP
concentrations were not substantially affected by antibody administration,
suggesting that redistribution of PCP from the testis is too slow to benefit from
a limited dose of antibody. These results indicate that anti-PCP IgG can
preferentially protect the brain for approximately 4 weeks after IgG
administration, even when the antibody binding capacity should have been
saturated with continuously administered PCP.
PMID- 10688595
TI - Targeted antioxidant properties of N-[(tetramethyl-3-pyrroline-3
carboxamido)propyl]phthalimide and its nitroxide metabolite in preventing
postischemic myocardial injury.
AB - We investigated the cardioprotective efficacy of a new compound based on 2,2,5,5
tetramethyl-3-pyrroline-3-carboxamide (TPC-NH). Biochemical studies using
electron paramagnetic resonance (EPR) spectroscopy suggest that TPC-NH is a
scavenger of reactive oxygen species. In vitro cellular studies show that TPC-NH
protects isolated cardiomyocytes against oxidative damage caused by superoxide
radicals. Ex vivo EPR studies on the isolated rat heart indicate that the TPC-NH
is metabolically oxidized to the nitroxide form. Studies were also performed in
the isolated rat heart model to measure the efficacy of TPC-NH and its
metabolites in preventing postischemic reperfusion injury. Serial measurements of
contractile function were performed on hearts subjected to ischemia-reperfusion.
Hearts were either untreated or treated with 50 microM TPC-NH or with its
metabolites for 1 min before ischemia and during the first 5 min of reflow. TPC
NH showed marked protection with a more than 3-fold increased recovery of
contractile function compared with control hearts, whereas its oxidative
metabolites exhibited significant but lower protection. Thus, TPC-NH and, to a
lesser extent, its oxidation metabolites exhibit potent membrane-targeted
antioxidant action and exert marked protection against myocardial injury in the
postischemic heart.
PMID- 10688596
TI - Disposition of dodecanedioic acid in humans.
AB - The disposition of dodecanedioic acid (C12) was investigated in six overnight
fasting healthy male volunteers, who received a 165-min i. v. infusion of 42.45
mmol of C12 added to 150 microCi of [1-12-(14)C]C12. Blood samples were collected
up to 360 min after the start of infusion, and concentration of serum labeled C12
was determined. Expired radioactivity (microCi/min) was measured up to 600 min
and at 24 h. The 24-h C12 urinary excretion was around 5% of the administered
amount. The percentage of C12 oxidized was 81.7 +/- 9.5% (mean +/- S.D.) of
administered amount as estimated from the area under the curve of measured
(14)CO(2) expiration rate. C12 kinetics was described by assuming a single
compartment. A saturable rate of C12 tissue uptake (model A) and a linear rate of
tissue uptake (model B) were considered. The kinetics of CO(2) produced by C12
oxidation was described by a fast pathway acting in parallel to a slow pathway
modeled by first order kinetics. Parameters of model B were estimated for each
subject, whereas model A was identified by fitting the pooled data of all
subjects. On the basis of estimates obtained from model B, an average calorie
delivery of 500 kcal/day was predicted in the plateau phase for the infusion rate
of our experiments. When estimated from model A, the maximal rate of tissue
uptake was 0.38 +/- 0.08 mmol/min, with a maximal calorie delivery of 750
kcal/day. These results appear promising for C12 utilization in parenteral
nutrition, because C12 elimination with urine is low, whereas tissue uptake and
oxidation are rather efficient.
PMID- 10688597
TI - Central administration of methamphetamine synergizes with metabolic inhibition to
deplete striatal monoamines.
AB - These studies examined, in vivo, the effect of local intrastriatal perfusion of
methamphetamine (MA) on dopamine (DA) and glutamate release in relation to
changes in striatal DA and serotonin (5-HT) content measured 1 week after
treatment. Interactions between the inhibition of energy metabolism and the
direct perfusion of MA on long-term decreases in DA and 5-HT content also were
investigated. MA (100 microM), the succinate dehydrogenase inhibitor malonate, or
the combination of MA and malonate was reverse-dialyzed into the striatum for 8
h. The continuous local perfusion of MA alone increased DA release by 30-fold,
similar to that seen after systemic administration, but did not increase
glutamate or body temperature, and did not deplete neurotransmitter content.
Malonate perfusion increased both DA and glutamate overflow, and dose dependently
decreased DA content. 5-HT content was not as affected by malonate perfusions
(200 mM malonate depleted DA by 66% and 5-HT by 40%). When MA was coperfused with
200 mM malonate, DA content was reduced by 80% and to a greater extent compared
with malonate alone. Coperfusion of MA and 200 mM malonate did not enhance 5-HT
loss. Overall, the present findings provide evidence that energy metabolism plays
an important role in MA toxicity and that striatal dopaminergic terminals are
more vulnerable than 5-HT terminals to damage after metabolic stress.
PMID- 10688598
TI - Structure-pharmacokinetics relationship of series of aminosteroidal neuromuscular
blocking agents in the cat.
AB - To obtain more insight in the relationship between physicochemical properties of
neuromuscular blocking agents (NMBAs) and their pharmacokinetic characteristics,
a series of 12 aminosteroidal NMBAs, supplemented with data on five related NMBAs
from the literature, was investigated in anaesthetized cats. After i.v. bolus
injection, plasma concentration decreased very rapidly, showing a biphasic
pattern, with half-lives ranging from 0.4 to 1.4 min, and from 3 to 10 min,
respectively. Clearance was in the range from 24 to 58 ml. min(-1). kg(-1).
Compounds containing an acetyl-ester group at position 3 were partly metabolized
to the 3-OH derivative. The urinary excretion of the parent drug and metabolites
amounted to <10% for each of the compounds. The parent drugs were excreted in
large amounts into bile, along with smaller amounts of 3-OH derivatives. The
terminal half-life of the urinary and biliary excretion rate were markedly longer
than the apparent terminal half-life in plasma, ranging from 11 to 40 min, and
from 119 to 489 min in urine and bile, respectively. Lipophilicity of the NMBAs,
expressed as the partition coefficient octanol/Krebs (log P), was found to be
correlated positively with unbound plasma clearance and unbound initial plasma
clearance, and negatively with plasma half-life, volume of distribution at steady
state, and mean residence time. The increase of the unbound plasma clearance with
increasing lipophilicity is counteracted by the concurrent increase in plasma
protein binding.
PMID- 10688599
TI - Inhibitors of phospholipase C prevent glutamate neurotoxicity in primary cultures
of cerebellar neurons.
AB - The role of phospholipase C in the molecular mechanism of glutamate neurotoxicity
was assessed in primary cultures of cerebellar neurons. It is shown that 1-[6
[[(17b)-3-methoxyestra-1,3, 5(10)-trien-17-yl]amino] hexyl]-1H-pyrrole-2,5-dione
(U-73122) and 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphorylcholine (Et-18
OCH(3)), two agents that inhibit phospholipase C, prevent glutamate and N-methyl
D-aspartic acid (NMDA) neurotoxicity. It is shown that both compounds prevent
glutamate neurotoxicity at concentrations lower than those required to inhibit
carbachol-induced hydrolysis of inositol phospholipids. In contrast, it was a
good correlation between the concentrations of U-73122 and Et-18-OCH(3) required
to inhibit NMDA-induced hydrolysis of phospholipids and those required to prevent
glutamate and NMDA neurotoxicity. NMDA-induced hydrolysis of phospholipids is
inhibited by nitroarginine, an inhibitor of nitric-oxide synthase, and is
mimicked by the nitric oxide-generating agent S-nitroso-N-acetylpenicillamine.
The results reported indicate that glutamate neurotoxicity would be mediated by
activation of NMDA receptors, leading to activation of nitric-oxide synthase and
increased formation of nitric oxide, which results in increased activity of
phospholipase C. Inhibition of phospholipase C by U-73122 or Et-18-OCH(3)
prevents glutamate-induced neuronal death.
PMID- 10688600
TI - M(2) and M(4) receptor knockout mice: muscarinic receptor function in cardiac and
smooth muscle in vitro.
AB - Peripheral muscarinic receptors play key roles in the control of heart rate and
smooth muscle activity. In this study, bradycardic and smooth muscle contractile
responses to the muscarinic agonist carbamylcholine were compared in isolated
tissues from M(2) and M(4) muscarinic receptor knockout mice and their wild-type
littermates. Carbamylcholine (1 x 10(-8)-3 x 10(-5) M) produced similar
concentration-dependent bradycardia in spontaneously beating atria from M(4)
receptor knockout and wild-type control mice. In contrast, carbamylcholine did
not produce bradycardia in atria derived from M(2) receptor knockout mice,
whereas such atria were responsive to adenosine-induced bradycardia.
Carbamylcholine-induced contractile responses were similar in stomach fundus,
urinary bladder, and tracheal preparations from M(4) receptor knockout mice and
their wild-type littermates for each tissue (-logEC(50) values ranging from 6.20
+/- 0.10 to 6.76 +/- 0.08), suggesting that M(4) receptors do not participate in
smooth muscle contraction in these tissues. In contrast, approximately 2-fold
higher carbamylcholine concentration was required for contraction of stomach
fundus, urinary bladder, and trachea from M(2) receptor knockout mice (-logEC(50)
= 6.39 +/- 0.05, 6.07 +/- 0.06, and 6.27 +/- 0.12, respectively) than from wild
type littermates (-logEC(50) = 6.68 +/- 0.07, 6.27 +/- 0.07, and 6.56 +/- 0.06,
respectively). Furthermore, the affinity of the M(2) "selective" receptor
antagonist AF-DX116 in inhibiting carbamylcholine-induced smooth muscle
contraction was significantly reduced in M(2) receptor knockout mice compared
with tissues from wild-type littermates. Collectively, these results provide
direct and unambiguous evidence that M(2) receptors mediate muscarinic receptor
induced bradycardia and play a role in smooth muscle contractility, whereas M(4)
receptors are not involved in stomach fundus, urinary bladder, or tracheal
contractility.
PMID- 10688601
TI - Cloning and pharmacological characterization of the rat CB(2) cannabinoid
receptor.
AB - Many of the pharmacological effects of Delta(9)-tetrahydrocannabinol are mediated
through CB(1) and CB(2) cannabinoid receptors. However, with the discovery of
endogenous cannabinoids, some discrepancies have arisen. Furthermore, unlike the
CB(1) receptor, the sequences of the mouse and human CB(2) receptor are
divergent, raising the possibility of species specificity. The gene for the rat
CB(2) receptor was cloned, expressed, and its properties compared with those of
mouse and human CB(2) receptors. Sequence analysis of the coding region of the
rat CB(2) genomic clone indicates 90% nucleic acid identity (93% amino acid
identity) between rat and mouse and 81% nucleic acid identity (81% amino acid
identity) between rat and human. The rat CB(2) receptor was stably expressed in
human embryonic kidney-293 cells to examine its pharmacology. The rat CB(2)
showed low affinity for anandamide, an endogenous ligand shown to act at the
CB(1) receptor. In contrast, high-affinity binding for SR144528 (CB(2)-selective
antagonist) as well as several cannabinoid receptor agonists was observed.
Coupling to adenylate cyclase was observed. Aspects of the pharmacology of
palmitoylethanolamide were also examined. It bound to CB(1) and CB(2) receptors
with low affinity and stimulated GTPgammaS binding in the cerebellum and CB(2)
expressing cell lines with low potency. The data in this study suggest that the
discrepancies in affinities between rat and human may represent species
differences. The rat CB(2) receptor genomic clone will be a useful tool for
studying the function and regulation of CB(2) in rats.
PMID- 10688602
TI - 6-NO(2)-norepinephrine increases norepinephrine release and inhibits
norepinephrine uptake in rat spinal synaptosomes.
AB - Nitric oxide has been shown to react under physiologic conditions with
norepinephrine (NE) to produce 6-nitro-norepinephrine (6-NO(2)-NE), a compound
that enhances NE release in the brain. Previous studies suggest that 6-NO(2)-NE
is formed in the spinal cord and stimulates spinal NE release to produce
analgesia. The purpose of the current studies was to examine the mechanisms by
which 6-NO(2)-NE stimulates NE release in the spinal cord. Crude synaptosomes
were prepared from spinal cords of male Sprague-Dawley rats and loaded with
[(3)H]NE. Incubation of synaptosomes with 6-NO(2)-NE resulted in a release of NE,
with a threshold of 1 microM 6-NO(2)-NE and a maximum effect of 30% fractional
release. NE transporter inhibitors desipramine and nomifensine blocked NE release
from 6-NO(2)-NE, and desipramine exhibited an IC(50) of 9.6 microM. NE release
from 6-NO(2)-NE was dependent on external Na(+), but not Ca(2+) or the activity
of guanylate cyclase. 6-NO(2)-NE also blocked uptake of [(3)H]NE into
synaptosomes, with an IC(50) of 8.3 microM. These data are consistent with a
direct action of 6-NO(2)-NE on noradrenergic terminals in the spinal cord to
release NE. This action is independent of guanylate cyclase activation, and most
likely shares a common mechanism with classic monoamine releasers such as
amphetamine that cause direct release of NE from vesicles into the nerve terminal
cytoplasm, leading to extracellular release by reverse transport.
PMID- 10688603
TI - Modulation of cellular calcium by sigma-2 receptors: release from intracellular
stores in human SK-N-SH neuroblastoma cells.
AB - Human SK-N-SH neuroblastoma cells expressed sigma-1 and sigma-2 receptors with
similar pharmacological profiles to those of rodent-derived tissues, although
sigma-2 receptors exhibited some affinity differences that might suggest
heterogeneity or species differences. Structurally diverse sigma ligands produced
two types of increases in intracellular (cytosolic) Ca(2+) concentration
([Ca(2+)](i)) in these cells. CB-64D, CB-64L, JL-II-147, BD737, LR172, BD1008,
haloperidol, reduced haloperidol, and ibogaine all produced an immediate, dose
dependent, and transient rise in [Ca(2+)](i). Sigma-inactive compounds
structurally similar to the most active sigma ligands and ligands for several
neurotransmitter receptors produced little or no effect. The high activity of CB
64D and ibogaine (sigma-2-selective ligands) compared with the low activity of
(+)-pentazocine and other (+)-benzomorphans (sigma-1-selective ligands), in
addition to enantioselectivity for CB-64D over CB-64L, strongly indicated
mediation by sigma-2 receptors. The effect of CB-64D and BD737 was blocked by the
sigma antagonists BD1047 and BD1063, further confirming specificity as a receptor
mediated event. The transient rise in [Ca(2+)](i) occurred in the absence of
extracellular Ca(2+) and was completely eliminated by pretreatment of cells with
thapsigargin. Thus, sigma-2 receptors stimulate a transient release of Ca(2+)
from the endoplasmic reticulum. Prolonged exposure of cells to sigma-receptor
ligands resulted in a latent and sustained rise in [Ca(2+)](i), with a
pharmacological profile identical to that of the transient rise. This sustained
rise in [Ca(2+)](i) was affected by neither the removal of extracellular Ca(2+)
nor thapsigargin pretreatment, suggesting latent sigma-2 receptor-induced release
from thapsigargin-insensitive intracellular Ca(2+) stores. Sigma-2 receptors may
use Ca(2+) signals in producing cellular effects.
PMID- 10688604
TI - Peroxynitrite, a two-edged sword in post-ischemic myocardial injury-dichotomy of
action in crystalloid- versus blood-perfused hearts.
AB - Peroxynitrite (ONOO(-)) is widely recognized as a mediator of NO. toxicity, but
recent studies have indicated that this compound may also have physiologic
activity and induces vascular relaxation as well as inhibition of platelet
aggregation and neutrophil adhesion. The present experiment was designed to
determine whether ONOO(-) may exert different effects on postischemic myocardial
injury in a crystalloid perfusion environment versus a blood perfusion
environment and, if it does, to clarify the mechanisms causing any differences.
In Krebs-Henseleit buffer-perfused rabbit hearts, administration of ONOO(-) at
the onset of reperfusion enhanced myocardial injury in a concentration-dependent
fashion with a significant effective concentration of 30 microM. In contrast, in
blood-perfused hearts, administration of ONOO(-) (1 to 30 microM) significantly
attenuated postmyocardial injury as evidenced by improved cardiac function
recovery, preserved endothelial function, decreased myocardial creatine kinase
loss, and reduced necrotic size. The minimal and maximal protective
concentrations were determined to be 1 and 3 microM, respectively. When a high
concentration of ONOO(-) (i.e., 100 microM) was administered, a detrimental
effect was observed. Administration of ONOO(-) decreased neutrophil accumulation
in the ischemic-reperfused myocardial tissue in a concentration-dependent manner
in blood-perfused hearts and inhibited neutrophil adhesion to cultured
endothelial cells exposed to hypoxia/reoxygenation. Taken together, these results
demonstrate that ONOO(-) may act as a "double-edged sword" in postischemic
myocardial injury. This compound is directly toxic to the cardiac tissue at a
relatively high concentration, but it can indirectly protect myocardial cells
from neutrophil-induced injury at a much lower concentration.
PMID- 10688605
TI - c-Myc antisense limits rat liver regeneration and indicates role for c-Myc in
regulating cytochrome P-450 3A activity.
AB - Expression of c-myc protein is associated with cell proliferation. The present
study uses antisense oligomers to inhibit c-myc expression in the regenerating
rat liver after 70% partial hepatectomy (PH). Antisense phosphorodiamidate
morpholino oligomers (novel DNA analogs) were administered i.p. immediately after
surgery to block expression of c-myc within the first 24 h after PH. A 20-mer PMO
complimentary to the c-myc mRNA at the translation start site was an effective
sequence (AVI-4126, 5'-ACGTTGAGGGGCATCGTCGC-3'). A single i.p. dose of 0.5 mg/kg
AVI-4126 caused reduction of the regenerating liver c-myc protein in a sequence
specific and dose-dependent manner. Inhibition of c-myc expression resulted in
reduction of proliferating cell nuclear antigen and arrested cells in the
G(0)/G(1) phase of the cell cycle. The ratio of G(2):G(0) cell populations in the
regenerating liver 24 h after PH dropped from 29.1 in saline vehicle-treated rats
to 18.0 in rats treated with 2.5 mg/kg AVI-4126. The expression of cell cycle
checkpoint protein p53 was inhibited with increasing doses of AVI-4126, but
expression of p21(waf-1) was unaffected. The activity of cytochrome P-450 3A2
(CYP3A2) was evaluated by immunoblot analysis and erythromycin N-demethylation.
AVI-4126 did not alter CYP3A activity in nonhepatectamized animals but showed a
dose-dependent decrease in PH rats. We conclude that AVI-4126, antisense oligomer
to c-myc, can reduce cell proliferation in the regenerating rat liver.
Furthermore, inhibition of c-myc may indirectly influence the expression of
CYP3A.
PMID- 10688606
TI - Sustained reduction in myocardial reperfusion injury with an adenosine receptor
antagonist: possible role of the neutrophil chemoattractant response.
AB - Recent studies have demonstrated that three membrane-permeant A(1) receptor
antagonists reduced infarct size in a model of ischemia followed by brief
reperfusion. However, it was not determined whether cardioprotection was mediated
by nonspecific intracellular effects of these highly lipophilic drugs and whether
the antagonists only delayed myocardial necrosis without affecting the ultimate
infarct size. In the present study, closed-chest dogs were subjected to 90 min of
left anterior descending coronary artery occlusion and 72 h of reperfusion and
received either a nonmembrane-permeant adenosine receptor blocker that is devoid
of direct intracellular effects and is 6-fold selective for the A(1) receptor [1,
3-dipropyl-8-p-sulfophenylxanthine (DPSPX); n = 11] or vehicle (n = 12). DPSPX
was administered as three 200-mg boluses 60 min before and 30 and 120 min after
reperfusion. The area of necrosis was determined histologically and expressed as
a percentage of the area at risk. Baseline predictors of infarct size were
similar in the two groups. The ratio of the area of necrosis to the area at risk
was less in the DPSPX group (17.8 +/- 4.3% versus 35.0 +/- 1.9%; P =. 012), and
DPSPX improved regional ventricular function. Under both basal and stimulated
(formyl-Met-Leu-Phe) conditions, suspensions of human neutrophils generated
extracellular adenosine levels (approximately 50 nM) sufficient to activate A(1)
receptors. Moreover, both DPSPX and 1,3-dipropyl-8-cyclopentylxanthine, a
selective A(1) receptor antagonist, significantly reduced the chemoattractant
response of neutrophils to formyl-Met-Leu-Phe. We conclude that blockade of A(1)
adenosine receptors attenuates myocardial ischemic/reperfusion injury, possibly
in part by decreasing the chemoattractant response of neutrophils.
PMID- 10688607
TI - A mibefradil metabolite is a potent intracellular blocker of L-type Ca(2+)
currents in pancreatic beta-cells.
AB - It has been shown that mibefradil (Ro 40-5967) exerts a selective inhibitory
effect on T-type Ca(2+) currents, although at higher concentrations it can
antagonize high voltage-activated Ca(2+) currents. The action of mibefradil on
Ca(2+) channels is use- and steady-state-dependent and the binding site of
mibefradil on L-type Ca(2+) channels is different from that of dihydropyridines.
By using conventional whole-cell and perforated patch-clamp techniques, we showed
that mibefradil has an inhibitory effect on both T- and L-type Ca(2+) currents in
insulin-secreting cells. However, the effect on L-type Ca(2+) currents was time
dependent and poorly reversible in perforated patch-clamp experiments. By using
mass spectrometry, we demonstrated that mibefradil accumulates inside cells, and
furthermore, a metabolite of mibefradil was detected. Intracellular application
of this metabolite selectively blocked the L-type Ca(2+) current, whereas
mibefradil exerted no effect. This study demonstrates that mibefradil permeates
into cells and is hydrolyzed to a metabolite that blocks L-type Ca(2+) channels
specifically by acting at the inner side of the channel.
PMID- 10688608
TI - Radiotelemetric evaluation of hemodynamic effects of long-term ethanol in
spontaneously hypertensive and Wistar-Kyoto rats.
AB - This study determined the hemodynamic effects of chronic ethanol in telemetered
freely moving age-matched spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY)
rats. Changes in blood pressure (BP), heart rate (HR), and plasma norepinephrine
(as index of sympathetic activity) were evaluated in pair-fed rats receiving
liquid diet with or without ethanol (5%, w/v) for 12 weeks. The SHRs exhibited
higher baseline BP and lower HR compared with WKY rats. When normalized for body
weight, daily ethanol intake was higher in SHRs compared with WKY rats. However,
blood ethanol concentration was similar except for a higher level in SHRs at
weeks 7 through 9. Ethanol had no effect on BP in WKY rats but caused decreases
in BP in SHRs that reached a maximum (approximately 30 mm Hg) at week 5 and
remained thereafter. Ethanol also caused reductions in the BP variability and the
circadian fluctuations in BP in SHRs but not in WKY rats. Plasma norepinephrine
levels were elevated by ethanol in WKY rats, but not in SHRs. The HR was not
affected by ethanol in SHRs and showed increases in WKY rats. These findings
suggest that chronic ethanol feeding differentially affects BP in SHRs
(hypotension) and WKY rats (no effect). The lack of a hypotensive response to
ethanol in WKY rats may relate, at least partly, to the associated
sympathoexcitation. The present study used the telemetry technique for BP
measurement, which eliminates the confounding and stressful effects of other
conventional techniques.
PMID- 10688609
TI - D(2), but not D(1) dopamine receptor agonists potentiate cannabinoid-induced
sedation in nonhuman primates.
AB - In primates, CB(1) cannabinoid receptor agonists produce sedation and psychomotor
slowing, in contrast to behavioral stimulation produced by high doses of dopamine
receptor agonists. To investigate whether dopamine agonists attenuate the
sedative effects of a cannabinoid agonist in monkeys, we compared the effects of
D(1) or D(2) dopamine receptor agonists on spontaneous behavior in three to six
cynomolgus monkeys (Macaca fasicularis) alone and after administration of a low
dose of the CB(1) agonist levonantradol. Alone, the CB(1) cannabinoid receptor
agonist levonantradol (0.01-0. 3 mg/kg) induced sedation, ptosis, and decreased
locomotor and general activity. Alone, D(2)-type dopamine agonists quinelorane
(0. 001-1.0 mg/kg; n = 4) or pergolide (0.01-1.0 mg/kg) or a D(1) dopamine
agonist 6-chloro-7,8-dihydroxy-1-phenyl-2,3,4, 5-tetrahydro-3-allyl-[1H]-3
benzazepine (0.3-3.0 mg/kg) produced either no effect or promoted hyperactivity.
Thirty minutes after administration of a threshold dose of levonantradol (0.03
mg/kg), D(2)-type agonists, but not the D(1) agonist, precipitated marked
sedation, ptosis, and decreased general activity and locomotor activity. These
data inducate the following: 1) D(2,) but not D(1) dopamine agonists, potentiate
sedation in monkeys treated with a CB(1) cannabinoid agonist, at doses of
agonists that alone do not produce sedation; 2) the threshold dose for
cannabinoid-induced sedation is reduced by D(2) agonists, but not by a D(1)
dopamine agonist, differentiating D(1) and D(2) dopamine receptor linkage to
cannabinoid receptors; and 3) modulation of D(2) dopamine receptor activity by a
nonsedating dose of a cannabinoid agonist has implications for the
pathophysiology and treatment of dopamine-related neuropsychiatric disorders and
drug addiction. Cannabinoid agonists and D(2) dopamine agonists should be
combined with caution.
PMID- 10688610
TI - Carrier-mediated uptake of the endogenous cannabinoid anandamide in RBL-2H3
cells.
AB - Anandamide (N-arachidonylethanolamide) is an endogenous cannabinoid that mimics
the pharmacologic effects of Delta(9)-tetrahydrocannabinol, the major bioactive
substance in marijuana. Anandamide appears to be synthesized, released, and
inactivated by mechanisms similar to those for other neurotransmitters. Of
interest to the present studies are reports that anandamide undergoes carrier
mediated uptake into neuronal or glial cells after release, followed by rapid
intracellular degradation by the intracellular fatty acid amidohydrolase. In
addition to effects in the brain, anandamide has multiple effects in the
periphery, particularly on cells of the immune system that express both a
peripheral cannabinoid receptor and amidohydrolase enzyme. We have performed a
detailed characterization of anandamide uptake in the cognate mast cell line RBL
2H3 to test the hypothesis that the uptake system in peripheral cells is also
carrier-mediated and functionally similar to that observed in the central nervous
system. RBL-2H3 cells exhibited robust, saturable transport of [(3)H]anandamide
that was both time- and temperature-sensitive. This transport activity was not
dependent on extracellular ion gradients for uptake and was inhibited selectively
by other fatty acid-derived molecules, anandamide congeners, and the psychoactive
cannabinoids such as Delta(9)-tetrahydrocannabinol. We conclude that anandamide
transport in the RBL-2H3 cells is carrier-mediated, and uptake in peripheral
cells is functionally and pharmacologically identical with that observed in
neurons and astrocytes.
PMID- 10688611
TI - Metabolite anion carriers mediate the uptake of the anionic drug fluorescein in
renal cortical mitochondria.
AB - The fluorescent organic anion fluorescein (FL) accumulates in proximal tubular
cells of the kidney during renal secretion. In freshly isolated and permeabilized
proximal tubular cells, the uptake was reduced but still sensitive to probenecid,
suggesting a concentrative mechanism that is associated with intracellular
compartments. Previous studies have shown that one of these compartments may be
mitochondrial. In this study, we further investigated the transport
characteristics of FL in isolated rat kidney cortex mitochondria. Mitochondrial
uptake of 100 microM FL was rapid, with an initial rate of 60 pmol/mg
protein.min, and reached equilibrium after 5 min. To characterize the transport
system(s) involved, FL uptake was studied in the absence and presence of
substrates or inhibitors specific for the various mitochondrial anion carriers.
Phenylsuccinate (10 mM), an inhibitor of the alpha-ketoglutarate carrier, reduced
uptake significantly with a maximum inhibition of 33% and an inhibitory constant
(-log IC(50)) of 4.0 +/- 0.4 (P <.05). The apparent K(m) for the phenylsuccinate
corrected FL uptake was 1.3 +/- 0.3 mM with a V(max) of 260 +/- 26 pmol/mg
protein.15 s. Substrates for the tricarboxylate and glutamate-aspartate carriers
significantly reduced the uptake of 100 microM FL with -log IC(50) values of 4.6
+/- 0.4 (citrate), 5.5 +/- 0.3 (glutamate), and 4.1 +/- 0.4 (aspartate).
Substrates for the monocarboxylate and dicarboxylate carriers were without
effect. The anionic drugs, valproate, indomethacin, and salicylate, significantly
reduced FL uptake, whereas cephaloglycin and cephaloridine had no effect.
Finally, a combination of phenylsuccinate, glutamate, and citrate reduced the
uptake by 66%, indicating that at least three metabolite carriers contribute
concomitantly to intramitochondrial FL transport.
PMID- 10688612
TI - Effects of intracavernous administration of selective antagonists of alpha(1)
adrenoceptor subtypes on erection in anesthetized rats and dogs.
AB - The proerectile properties of three novel alpha(1)-adrenoceptor (alpha(1)-ADR)
antagonists with different profiles of selectivity for the alpha(1)-ADR subtypes
have been evaluated in anesthetized rats and dogs on intracavernous (IC)
injection, in comparison with prazosin and phentolamine. In rats, the tested
compounds decreased blood pressure (BP) and increased IC pressure (ICP), as well
as the ratio ICP/BP. Rec 15/2841 (alpha(1a)- plus alpha(1L)-ADR-selective
antagonist) and Rec 15/2615 (alpha(1b)-ADR selective) were the most potent
compounds. The ICP/BP ratios calculated after injection of Rec 15/3039 (alpha(1d)
ADR selective) were not markedly different from those observed after vehicle
injection. Prazosin and phentolamine proved poorly active, their main effect
being hypotension. Approximate ED(25) values (dose of compound in micrograms
inducing 25% increase of ICP/BP ratio) were Rec 15/2615 (22 microgram/kg)>= Rec
15/2841 (29 microgram/kg) > prazosin (136 microgram/kg) > phentolamine (1298
microgram/kg) > Rec 15/3039 (9600 microgram/kg). Submaximal stimulation of the
cavernous nerve elicited an ICP rise whose amplitude was not altered by Rec
compounds. In contrast, prazosin and phentolamine decreased this ICP rise. All
compounds but 15/3039 induced significant increase of the ICP/BP ratio in dogs.
Rec 15/2615 proved to be the most interesting compound, inducing significant
increases of ICP/BP at doses practically devoid of effects on BP. The rank order
of potency in dog in increasing the ICP/BP ratio was similar to that observed in
rats. Only at the highest doses tested, all compounds, except Rec 15/3039,
decreased the ICP rise elicited by submaximal stimulation of the cavernous nerve.
Our data demonstrate that the alpha(1b)- and alpha(1L)-ADR subtypes are
functionally relevant for the erectile function in these models, and that
alpha(1b)- and/or alpha(1L)-ADR subtypes selective antagonists could represent a
real advantage in erectile dysfunction therapy.
PMID- 10688613
TI - Possible mechanism of hepatocyte injury induced by diphenylamine and its
structurally related nonsteroidal anti-inflammatory drugs.
AB - Diphenylamine is a common structure of nonsteroidal anti-inflammatory drugs
(NSAIDs) to uncouple mitochondrial oxidative phosphorylation and to cause a
decrease in hepatocellular ATP content and hepatocyte injury. The mechanism for
acute cell injury induced by diphenylamine and its structurally related NSAIDs
was investigated with rat liver mitochondria and freshly isolated hepatocytes,
focusing on the relation to the uncoupling of oxidative phosphorylation.
Incubation of mitochondria with diphenylamine as well as mefenamic acid and
diclofenac caused pseudoenergetic mitochondrial swelling, indicating that these
compounds induce mitochondrial membrane permeability transition. Diphenylamine
also caused changes in safranine-binding spectra to mitochondria that was
energized by succinate oxidation. This spectral shift indicates the loss of
mitochondrial membrane potentials, which is known as one of the characteristics
for uncouplers of oxidative phosphorylation, and also was caused by mefenamic
acid and diclofenac. Incubation of hepatocytes with mefenamic acid, diclofenac,
and diphenylamine diminished cellular ATP content, followed by leakage of lactose
dehydrogenase from hepatocytes. Fructose, a low K(m) substrate for glycolysis,
partially protected against the ATP depletion and hepatocyte injury induced by
these compounds. Further addition of oligomycin, which blocks ATPase, pronounced
the protection against cell injury. These results suggested that decreases in
cellular ATP content, mainly caused by uncoupling of mitochondrial oxidative
phosphorylation, were responsible for acute hepatocyte injury induced by
diphenylamine and structurally related NSAIDs.
PMID- 10688614
TI - Interleukin-13 modulates collagen homeostasis in human skin and keloid
fibroblasts.
AB - Interleukin (IL)-13 has been implicated in the pathogenesis of various diseases
characterized by fibrosis. We describe the effects of IL-13 on collagen
homeostasis from normal (NF) and keloid (KF) fibroblasts and compare these
effects with those of IL-4 and transforming growth factor (TGF)-beta(1). Total
collagen generation was up-regulated in NF after 48 h of stimulation by IL-13; in
KF, IL-13 stimulated a more rapid collagen response. The kinetics and magnitude
of collagen generation induced by IL-13 were equivalent to those induced by
similar concentrations of IL-4 and TGF-beta(1). Collagen type I production
paralleled total collagen generation from both NF and KF; however, IL-4-induced
collagen type I and total collagen production from KF was more transient than
that induced by either IL-13 or TGF-beta(1). Procollagen 1alpha1 gene expression
was induced in KF by stimulation with IL-13 for 24 h. Moreover, IL-13 was unique
among these three cytokines in its ability to induce gene expression for
procollagen 3alpha1. Finally, IL-13 inhibited IL-1beta-induced matrix
metalloproteinase (MMP)-1 and MMP-3 production and enhanced tissue inhibitor of
metalloproteinase (TIMP)-1 generation from NF; although similar effects were
observed with IL-4, TGF-beta(1) transiently enhanced MMP-1 and MMP-3 generation
without effecting TIMP-1. In KF, IL-13 and IL-4 inhibited MMP-3, whereas TGF
beta(1) enhanced MMP-3; TIMP-1 was unaffected by any of the three cytokines.
These data demonstrate both the profibrotic effects of IL-13 on collagen
homeostasis and the potential differential regulation of collagen homeostasis in
fibroblast subtypes by IL-13.
PMID- 10688615
TI - Ca(2+) mobilization evoked by chloroform in Madin-Darby canine kidney cells.
AB - The effect of chloroform on Ca(2+) mobilization in Madin-Darby canine kidney
cells was examined by using Fura-2 as a Ca(2+) probe. Chloroform (24-248 mM)
concentration dependently increased intracellular Ca(2+) concentration
([Ca(2+)](i)). Ca(2+) removal inhibited the Ca(2+) signals evoked by 93 to 248 mM
chloroform by reducing both the initial rise and the sustained phase. In Ca(2+)
free medium, pretreatment with 93 mM chloroform abolished the Ca(2+) release
induced by 1 microM thapsigargin, an endoplasmic reticulum Ca(2+) pump inhibitor,
and partially reduced the Ca(2+) release induced by 2 microM carbonylcyanide m
chlorophenylhydrazone, a mitochondrial uncoupler. Pretreatment with
carbonylcyanide m-chlorophenylhydrazone and thapsigargin to deplete the Ca(2+)
stores in mitochondria and the endoplasmic reticulum, respectively, only
partially inhibited chloroform-induced Ca(2+) release. This suggests that
chloroform released Ca(2+) from multiple internal pools. The addition of 3 mM
Ca(2+) increased [Ca(2+)](i) after pretreatment with 93 mM chloroform in Ca(2+)
free medium. La(3+) (1 mM) partially inhibited the [Ca(2+)](i) increase induced
by 93 mM chloroform. Chloroform (93 mM)-induced Ca(2+) release was not altered
when the formation of inositol-1,4,5-trisphosphate was abolished by U73122 (2
microM), a phospholipase C inhibitor, but was inhibited by 90% by inhibition of
phospholipase A(2) with 40 microM aristolochic acid. Collectively, we found that
93 mM chloroform increased [Ca(2+)](i) in Madin-Darby canine kidney cells by
releasing Ca(2+) from multiple stores in a manner independent of the formation of
inositol-1,4,5-trisphosphate, followed by Ca(2+) entry from external medium.
Other solvents, such as ethanol, methanol, and DMSO, did not affect the resting
[Ca(2+)](i) at a concentration of 248 mM.
PMID- 10688616
TI - Probable involvement of the 5-hydroxytryptamine(4) receptor in methotrexate
induced delayed emesis in dogs.
AB - Delayed emesis in cancer patients undergoing chemotherapy remains a significant
problem. The pathogenesis of delayed emesis is still obscure. It was recently
demonstrated that methotrexate (MTX), an anticancer drug, evoked delayed emesis
in dogs in a manner similar to its actions in humans. We evaluated the antiemetic
activity of FK1052, a potent antagonist for both the 5-hydroxytryptamine (HT)(3)
and 5-HT(4) receptors, on delayed emesis induced by MTX in beagle dogs. Animal
behavior was recorded for 3 days using a video camera. Delayed emesis lasting up
to 72 h was observed in dogs treated with MTX (2.5 mg/kg i.v.), but acute emesis
did not occur. The following antiemetics, at the dose that prevents cisplatin
induced acute emesis in dogs, were administered i.v. as multiple injections every
12 h during days 2 to 3. FK1052 (1 and 3.2 mg/kg) significantly reduced the
emetic episodes caused by MTX, whereas ondansetron (1 mg/kg), a selective 5-HT(3)
receptor antagonist, was not effective. The emetic episodes induced by MTX were
also inhibited by another 5-HT(3/4) receptor antagonist, tropisetron (1 mg/kg).
CP-122,721 (0. 1 mg/kg), a potent selective tachykinin NK(1) receptor antagonist,
significantly reduced the emetic responses to MTX. Copper sulfate-induced emesis
in dogs was also prevented by FK1052, tropisetron, and CP-122,721 but not by
ondansetron. FK1052, tropisetron, and ondansetron had negligible affinity for the
NK(1) receptor at 1 microM. These results suggest that the 5-HT(4) receptor may
be in part involved in the production of delayed emesis induced by MTX in dogs
and that FK1052 may be a useful drug against both acute and delayed emesis
induced by cancer chemotherapy.
PMID- 10688617
TI - Induction of cytochrome P-450 1A2 by oxidized tryptophan in Hepa lclc7 cells.
AB - Recent studies from this laboratory have demonstrated that L-tryptophan, after
oxidation either by UV-irradiation or ozone, induces aryl hydrocarbon receptor
(AhR) activation and binding of the liganded AhR complex to its specific DNA
recognition site, thereby initiating transcription of the cytochrome P-450 1a1
(Cyp1a1) gene with concomitant increase of CYP1A1 protein and 7-ethoxyresorufin O
deethylase activity in wild-type mouse hepatoma cells, Hepa lclc7 (Hepa-1), in
culture. Temporary inhibition of protein synthesis by cycloheximide resulted in
superinduction of oxidized tryptophan-inducible CYP1A1 mRNA, protein, and 7
ethoxyresorufin O-deethylase activity in Hepa-1 cells. In the present
communication, the results obtained by immunoblot analyses with monoclonal
CYP1A1/1A2 antibody (NIH 1-7-1) demonstrate that both UV- or ozone-oxidized
tryptophan also induce CYP1A2 protein in Hepa-1 cells. CYP1A2 mRNA, detected by
reverse transcription-polymerase chain reaction, was markedly induced in the UV-
or ozone-oxidized tryptophan-treated cells. Temporary inhibition of protein
synthesis by cycloheximide further induced oxidized tryptophan-inducible CYP1A2
mRNA as well as the protein in Hepa-1 cells. This is the first report
demonstrating the induction of CYP1A2 mRNA and protein in Hepa-1 cells.
PMID- 10688618
TI - Block of human heart hH1 sodium channels by amitriptyline.
AB - Amitriptyline is a tricyclic antidepressant used to treat major depression and
various neuropathic pain syndromes. This drug also causes cardiac toxicity in
patients with overdose. We characterized the tonic and use-dependent
amitriptyline block of human cardiac (hH1) Na(+) channels expressed in human
embryonic kidney cells under voltage-clamp conditions. Our results show that,
near the therapeutic plasma concentration of 1 microM, amitriptyline is an
effective use-dependent blocker of hH1 Na(+) channels during repetitive pulses
(approximately 55% block at 5 Hz). The tonic block for resting and for
inactivated hH1 channels by amitriptyline (0.1-100 microM) yielded IC(50) values
(50% inhibitory concentration) of 24.8 +/- 2.0 (n = 9) and 0.58 +/- 0.03 microM
(n = 7), respectively. Substitution of phenylalanine with lysine at the hH1-F1760
position, a putative binding site for local anesthetics, eliminates the use
dependent block by amitriptyline at 1 microM. The time constants of recovery from
the inactivated-state amitriptyline block in hH1 wild-type and hH1-F1760K mutant
channels are 8.0 +/- 0. 5 (n = 6) and 0.45 +/- 0.07 s (n = 6), respectively. A
substitution at either hH1-F1760K or hH1-Y1767K significantly increases the
IC(50) values for resting and inactivated states of amitriptyline, but the
increase is much more pronounced with the hH1-F1760K mutation. Because these two
residues were proposed to form a part of the local anesthetic binding site, we
conclude that amitriptyline and local anesthetics interact with a common binding
site. Furthermore, at therapeutic concentrations, the ability of amitriptyline to
act as a potent use-dependent blocker of Na(+) channels may, in part, explain its
analgesic actions.
PMID- 10688619
TI - Effects of age on in vitro midazolam biotransformation in male CD-1 mouse liver
microsomes.
AB - To study age-related changes in drug metabolism, we examined the in vitro
biotransformation of midazolam (MDZ), a human cytochrome P-450 (CYP) 3A
substrate, using liver microsomes from three age groups of male CD-1 mice ranging
from 6 weeks to 2 years old. MDZ was metabolized to two major products, alpha-OH-
and 4-OH-MDZ, which were quantified by HPLC. For both metabolites, V(max) values
were reduced in old livers (P <.05), while K(m) values did not change with age.
The net intrinsic clearance (the sum of V(max)/K(m) for both pathways) also was
reduced in the old animals (P <.05). The capacity of ketoconazole, a CYP3A
inhibitor in humans, to inhibit the biotransformation of MDZ and of alprazolam,
another human CYP3A substrate, did not differ significantly with age. At 100
microM alprazolam, 0.5 microM ketoconazole inhibited metabolite formation by
>80%. At 30 microM MDZ, 2.5 microM ketoconazole impaired 4-OH-MDZ formation by
88%, whereas it reduced alpha-OH-MDZ formation by only 46%. Immunoinhibition
studies with polyclonal anti-rat CYP3A1/2 and CYP2C11 antibodies confirmed that 4
OH-MDZ formation was largely CYP3A-dependent, while alpha-OH-MDZ formation was
mediated by CYP3A and -2C isoforms. Western blot analysis revealed decreased
microsomal content of CYP3A in old livers. Net intrinsic clearance of MDZ was
correlated with total CYP3A content (P <.001). These results demonstrate a
reduction in MDZ biotransformation in old male mice, which may be attributable,
in part, to decreased CYP3A content in old livers. Changes in expression and
activity of CYP2C isoforms also may contribute to age-related changes in MDZ
biotransformation, but this requires more investigation.
PMID- 10688620
TI - Polarized distribution of interleukin-1 receptors and their role in regulation of
serotonin transporter in placenta.
AB - We investigated the expression of interleukin-1 (IL-1) receptors and their
involvement in the regulation of the serotonin transporter gene expression in
human placenta. IL-1beta is an activator of the serotonin transporter gene
expression in JAR human placental choriocarcinoma cells as demonstrated by an
increase in the steady-state levels of the transporter mRNA and in serotonin
transport activity. This activation is blocked by IL-1 receptor antagonist.
Genistein also blocks the effect of IL-1beta, indicating involvement of tyrosine
phosphorylation in the process. Treatment of JAR cells with IL-1beta activates
mitogen-activated protein kinases and nuclear factor-kappaB. The nuclear factor
kappaB that is responsive to IL-1beta in these cells is the p65 homodimer.
Northern blot analysis and reverse transcription-polymerase chain reaction
revealed that JAR cells and human placenta express type I and type II IL-1
receptors. The binding sites for (125)I-IL-1beta are localized predominantly in
the maternal-facing brush border membrane of the syncytiotrophoblast. These
results show that IL-1 in the maternal circulation is likely to play a critical
role in the regulation of the serotonin transporter gene expression in the
placenta.
PMID- 10688621
TI - Disposition of methamphetamine and its metabolite amphetamine in brain and other
tissues in rats after intravenous administration.
AB - These studies characterized the concentration-time profile of (+)-methamphetamine
[(+)-METH] and its metabolite (+)-amphetamine [(+)-AMP] in the brain and five
other tissues after (+)-METH administration. Male Sprague-Dawley rats received a
pharmacologically active (+)-METH i.v. bolus dose (1.0 mg/kg) or a
nonpharmacologically active s.c. infusion (20 h at 1.2 mg/kg/day). Tissues (n = 3
per time point) were collected for more than four elimination half-lives in the
i.v. group, or at a single steady-state time point (20 h) in the s.c. group.
Based on data from the area under the concentration-time curves after i.v.
dosing, the rank order of (+)-METH tissue accumulation was kidney > spleen >
brain > liver > heart > serum with terminal elimination half-life values ranging
from 53 to 66 min. (+)-METH concentrations were highest at the first measured
time point (2 min) in all tissues except the spleen, which peaked at 10 min. The
brain-to-serum concentration ratio rose from 7:1 at 2 min to a peak of 13:1 at 20
min before equilibrating to a constant value of 8:1 at 2 h. Following s.c. (+)
METH dosing, the (+)-METH brain-to-serum concentration ratio was the same as the
equilibrated ratio following i.v. dosing. (+)-AMP concentrations peaked at 20 min
in all tissues before decaying with terminal elimination half-life values ranging
from 68 to 75 min. Analysis of the area under the concentration-time curve molar
amounts of (+)-AMP and (+)-METH showed that (+)-AMP accounted for approximately
one-third of the drug tissue exposure over time. Thus, these data indicate the
importance of both (+)-METH and (+)-AMP in pharmacological effects following i.v.
(+)-METH administration.
PMID- 10688622
TI - Targeting rat anti-mouse transferrin receptor monoclonal antibodies through blood
brain barrier in mouse.
AB - Drug targeting through the brain capillary endothelium, which forms the blood
brain barrier (BBB) in vivo, may be achieved with peptidomimetic monoclonal
antibodies that target peptide transcytosis systems on the BBB in vivo. Murine
monoclonal antibodies to the rat transferrin receptor, such as the OX26
monoclonal antibody, are targeted through the BBB on the transferrin receptor in
the rat. However, the present studies show the OX26 monoclonal antibody is not an
effective brain delivery vector in mice. The emergence of transgenic mouse models
creates a need for brain drug-targeting vectors for this species. Two rat
monoclonal antibodies, 8D3 and RI7-217, to the mouse transferrin receptor were
evaluated in the present studies. Both the RI7-217 and the 8D3 antibody had
comparable permeability-surface area products at the mouse BBB in vivo. However,
owing to a higher plasma area under the concentration curve, the mouse brain
uptake of the 8D3 antibody was higher, 3.1 +/- 0.4% of injected dose [(ID)/g]
compared with the brain uptake of the RI7 antibody, 1.6 +/- 0.2% ID/g, at 60 min
after i.v. injection. Conversely, the mouse brain uptake of the OX26 antibody,
which does not recognize the mouse transferrin receptor, was negligible, 0.06 +/-
0.01% ID/g. The RI7-127 antibody was more selective for brain because this
antibody was not measureably taken up by liver. The capillary depletion technique
demonstrated transcytosis of the RI7-217 antibody through the mouse BBB in vivo.
The brain uptake of the 8D3 antibody was saturable, consistent with a receptor
mediated transport process. In conclusion, these studies indicate rat monoclonal
antibodies to the mouse transferrin receptor may be used for brain drug-targeting
studies in mice such as transgenic mouse models.
PMID- 10688623
TI - Reward and somatic changes during precipitated nicotine withdrawal in rats:
centrally and peripherally mediated effects.
AB - The negative affective aspects of nicotine withdrawal have been hypothesized to
contribute to tobacco dependence. In the present studies in rats, brain
stimulation reward thresholds, conditioned place aversions, and somatic signs of
withdrawal were used to investigate the role of central and peripheral nicotinic
acetylcholine and opioid receptors in nicotine withdrawal. Rats prepared with
s.c. osmotic mini-pumps delivering 9.0 mg/kg/day nicotine hydrogen tartrate or
saline were administered various doses of the nicotinic antagonists mecamylamine
(s.c.), chlorisondamine (s. c. or i.c.v.), dihydro-beta-erythroidine (s.c.), or
the opiate antagonist naloxone (s.c.). Nicotine-treated rats receiving
mecamylamine or i.c.v. chlorisondamine exhibited elevated thresholds and more
somatic signs than saline-treated rats. Nicotine-treated rats receiving s.c.
chlorisondamine, at doses that do not readily cross the blood-brain barrier,
exhibited more somatic signs than saline-treated rats with no threshold
elevations. Naloxone administration produced threshold elevations and somatic
signs only at high doses that induced similar magnitude effects in both nicotine-
and saline-treated subjects. Mecamylamine or dihydro-beta-erythroidine
administration induced conditioned place aversions in nicotine-treated rats but
required higher doses than those needed to precipitate threshold elevations. In
contrast, naloxone administration induced conditioned place aversions at lower
doses than those required to precipitate threshold elevations and somatic signs.
These data provide evidence for a dissociation between centrally mediated
elevations in reward thresholds and somatic signs that are both centrally and
peripherally mediated. Furthermore, threshold elevations and somatic signs of
withdrawal appear to be mediated by cholinergic neurotransmission, whereas
conditioned place aversions appear to be primarily mediated by the opioid system.
PMID- 10688624
TI - The role of phosphodiesterase in mediating the effect of protein kinase C on
cyclic AMP accumulation upon kappa-opioid receptor stimulation in the rat heart.
AB - This study determined whether phosphodiesterase (PDE) was activated by protein
kinase C (PKC) upon kappa-receptor stimulation, and if so, to identify the
isozyme. We first studied the effects of trans-(+/-)-3,4-dichloro-N-methyl-N-(2
[1-pyrrolidinyl] cyclohexyl) benzeneacetamide methanesulphonate (U50,488H), a
selective kappa-opioid receptor (OR) agonist, and phorbol-12-myristate-13-acetate
(PMA), a PKC activator, on cAMP accumulation and PDE activity in rat ventricular
myocytes when PKC and PDE were inhibited by respective inhibitors. Like PMA,
U50,488H decreased the forskolin-stimulated cAMP accumulation and dose
dependently stimulated the PDE activity, which were antagonized by 10(-6) M
chelerythrine and bisindolylmaleimide I, selective PKC antagonists. In addition,
3-isobutyl-1-methylxanthine, a PDE inhibitor, dose-dependently attenuated the
inhibition on forskolin-stimulated cAMP accumulation and abolished the
stimulation on PDE activity by U50,488H and PMA. The observations suggest that
PKC may enhance cAMP degradation through activating PDE upon kappa-OR
stimulation. To identify the isozyme(s) mediating the effect of PKC upon kappa-OR
stimulation, selective inhibitors were used. We found that 10(-5) M Ro-20-1724, a
selective cAMP-specific PDE (PDE-IV) inhibitor, abolished the inhibitory effects
of U50,488H and PMA, whereas 8-methoxymethyl-3-isobutyl-1-methylxanthine, erythro
9-(2-hydroxy-3-nonyl) adenine, cilostamide, and zaprinast, selective inhibitors
of Ca(2+)/calmodulin-dependent PDE (PDE-I), cGMP-stimulated PDE (PDE-II), cGMP
inhibited PDE (PDE-III), and cGMP-specific PDE (PDE-V), respectively, had no
effect. Moreover, rolipram, another selective PDE-IV inhibitor, also dose
dependently attenuated the inhibition on forskolin-stimulated cAMP accumulation
and stimulation on PDE activity by U50,488H and PMA. In conclusion, this study
has provided evidence for the first time that PKC and PDE-IV mediate the action
of kappa-OR.
PMID- 10688625
TI - Accelerated blood clearance and altered biodistribution of repeated injections of
sterically stabilized liposomes.
AB - Sterically stabilized liposomes are considered promising carriers of therapeutic
agents because they can facilitate controlled release of the drugs, thereby
reducing drug-related toxicity and/or targeted delivery of drugs. Herein, we
studied the pharmacokinetics and biodistribution of repeated injections of
radiolabeled polyethyleneglycol (PEG) liposomes. Weekly injections of (99m)Tc-PEG
liposomes dramatically influenced the circulatory half-life in rats.
Biodistribution 4 h after the second dose showed a significantly reduced blood
content (from 52.6 +/- 3.7 to 0.6 +/- 0.1% injected dose (ID), P <.01)
accompanied by a highly increased uptake in the liver (from 8.1 +/- 0.8 to 46.2
+/- 9.8%ID, P <.01) and in the spleen (from 2.2 +/- 0.2 to 5.3 +/- 0.7%ID, P
<.01). At subsequent injections the effect was less pronounced: after the fourth
dose, the pharmacokinetics of the radiolabel had almost returned to normal. The
same phenomenon was observed in a rhesus monkey, but not in mice. The enhanced
blood clearance of the PEG liposomes also was observed in rats after transfusion
of serum from rats that had received PEG liposomes 1 week earlier, indicating
that the enhanced blood clearance was caused by a soluble serum factor. This
serum factor was a heat-labile molecule that coeluted on a size exclusion column
with a 150-kDa protein. In summary, i.v. administration of sterically stabilized
PEG liposomes significantly altered the pharmacokinetic behavior of subsequently
injected PEG liposomes in a time- and frequency-dependent manner. The observed
phenomenon may have important implications for the repeated administration of
sterically stabilized liposomes for targeted drug delivery.
PMID- 10688626
TI - Suppression of a high-affinity transport system for manganese in cadmium
resistant metallothionein-null cells.
AB - Cadmium is a hazardous heavy metal existing ubiquitously in the environment, but
the mechanism of cadmium transport into mammalian cells has been poorly
understood. Recently, we have established a cadmium-resistant cell line (Cd-rB5)
from immortalized metallothionein-null mouse cells, and found that Cd-rB5 cells
exhibited a marked decrease in cadmium uptake. To investigate the mechanism of
altered uptake of cadmium in Cd-rB5 cells, incorporation of various metals was
determined simultaneously using a multitracer technique. Cd-rB5 cells exhibited a
marked decrease in manganese incorporation as well as that of cadmium. However,
the reduced uptake of manganese was observed only at low concentrations,
suggesting that a high-affinity component of the Mn(2+) transport system was
suppressed in Cd-rB5 cells. Competition experiments and kinetic analyses revealed
that low concentrations of Cd(2+) and Mn(2+) share the same high-affinity pathway
for their entry into cells. The mutual competition of Cd(2+) and Mn(2+) uptake
was also observed in HeLa, PC12, and Caco-2 cells. The highest uptake of Cd(2+)
and Mn(2+) by parental cells occurred at neutral pH, suggesting that this pathway
is different from a divalent metal transporter 1 that can transport various
divalent metals including Cd(2+) and Mn(2+) under acidic conditions. These
results suggest that a high-affinity Mn(2+) transport system is used for
mammalian cellular cadmium uptake, and that the suppression of this pathway
caused a marked decrease in cadmium accumulation in cadmium-resistant
metallothionein-null cells.
PMID- 10688627
TI - Benazeprilat disposition and effect in dogs revisited with a
pharmacokinetic/pharmacodynamic modeling approach.
AB - The pharmacokinetic disposition of benazeprilat, an angiotensin-converting enzyme
(ACE) inhibitor (ACEI), was assessed with a nonlinear binding model in dogs. A
single oral benazepril dose, a single i.v. benazeprilat dose, or a daily oral
dose of benazepril for 14 consecutive days was administered. The activity of
benazeprilat was assessed by measuring plasma ACE inhibition with an ex vivo
assay. Benazeprilat data were fitted to equations corresponding to a
monocompartmental model with a volume equal to the extracellular space (
approximately 0.2 l/kg) in which a fraction of benazeprilat was nonlinearily
bound to ACE with both a saturable tissue and nontissue binding. The half-life of
benazeprilat elimination determined from this physiologically based model was 39
+/- 6 min. The estimated maximal binding capacity of benazeprilat to ACE was
approximately 23.5 nmol/kg, 90% of which was tissular. The estimated equilibrium
constant of dissociation (K(d)) of benazeprilat to ACE was 2.7 to 4.5 nM. IC(50)
values were one order of magnitude lower than K(d) values (i.e., approximately
0.27 nM). The nonlinear disposition of benazeprilat raised several issues and it
was concluded that the benazeprilat concentration profile was only relevant to
definition of an optimal dosage regimen if the appropriate kinetic model was used
to interpret the plasma data.
PMID- 10688628
TI - New insights on effect of kidney insufficiency on disposition of angiotensin
converting enzyme inhibitors: case of enalapril and benazepril in dogs.
AB - The influence of a renal injury on the disposition of benazeprilat, the active
moiety of benazepril, and of enalaprilat, the active moiety of enalapril, two
angiotensin-converting enzyme (ACE) inhibitors (ACEI), having different routes of
elimination in dog was investigated during a mild renal insufficiency obtained by
a nephrectomy-electrocoagulation method reducing glomerular filtration rate by
approximately 50%. Plasma concentrations of the active moieties were analyzed
with a physiologically based model taking into account the binding to ACE (high
affinity, low capacity). An influence of renal insufficiency on enalapril
disposition was shown with an increase in its plasma concentration, which was
correlated to the reduction of the glomerular filtration rate. No such effect was
evidenced for benazepril. With the physiologically based model analysis, it was
shown that renal impairment led to an increase of the apparent benazeprilat
clearance (260%), whereas that of enalaprilat was reduced to 40 to 55%. Renal
insufficiency had no significant effect either on the apparent volume of
distribution of each drug or on the binding parameters [i.e., maximal binding
capacity (B(max)) and affinity (K(d))]. Enalaprilat and benazeprilat inhibitory
action on ACE also was evaluated ex vivo. Similar patterns of inhibition were
observed for both drugs. Renal injury had no significant influence on the overall
effect of benazeprilat, whereas the inhibition effect of enalaprilat was
significantly increased. It was concluded that renal insufficiency may have
effects on the ACEI disposition but that the measurable active moiety plasma
concentration is not the most appropriate endpoint to describe and interpret the
consequence of a renal injury on ACEI.
PMID- 10688629
TI - Inhibition by intracellular Mg(2+) of recombinant N-methyl-D-aspartate receptors
expressed in Chinese hamster ovary cells.
AB - Intracellular Mg(2+) (Mg(i)(2+)) inhibits the N-methyl-D-aspartate (NMDA) subtype
of glutamate receptors in cultured cortical neurons. To examine the effects of
Mg(i)(2+) on recombinant NMDA receptors composed of subunit combinations found in
cortical neurons, we expressed heteromeric receptors composed of NR1/NR2A and of
NR1/NR2B subunits in Chinese hamster ovary (CHO) cells. We recorded whole-cell
currents from the recombinant receptors in the absence and presence of Mg(i)(2+).
The voltage dependence of control (0 Mg(i)(2+)) NMDA-activated currents obtained
from CHO cells transfected with NR1/NR2A and with NR1/NR2B receptors showed
outward rectification, a property that has been observed previously in native
cortical NMDA receptors. The magnitude and voltage dependence of inhibition by
Mg(i)(2+) of NMDA-activated currents were similar in CHO cells transfected with
NR1/NR2A receptors, CHO cells transfected with NR1/NR2B receptors, and in
cultured neurons expressing native NMDA receptors. These observations suggest
that Mg(i)(2+) has uniform effects on the native NMDA receptors expressed in
cortical neurons. Furthermore, inhibition by Mg(i)(2+) must not depend on
intracellular factors or post-translational receptor modifications that are
specific to neurons. Finally, the results indicate that the previously observed
differences between whole-cell and outside-out patch measurements of Mg(i)(2+)
inhibition could not result from poor control of voltage or Mg(i)(2+)
concentration in the dendrites of neurons. The most likely alternative
explanation is that patch excision causes an alteration in NMDA receptors that
results in more effective inhibition by Mg(i)(2+).
PMID- 10688630
TI - Regulation of extracellular concentrations of 5-hydroxytryptamine (5-HT) in mouse
striatum by 5-HT(1A) and 5-HT(1B) receptors.
AB - The ability of selective serotonin (5-HT) receptor agonists to reduce the
extracellular concentration of 5-HT was examined in the striatum of awake,
unrestrained mice by in vivo microdialysis. Systemic administration of either 8
OH-PIPAT (R-(+)-trans-8-hydroxy-2-[N-n-propyl-N-(3'-iodo-2'-propenyl)]
aminotetralin), a novel 5-HT(1A) receptor agonist, or CP 94,253, a selective 5
HT(1B) receptor agonist, resulted in significant dose-related reductions of
striatal 5-HT. The effect of 8-OH-PIPAT (1.0 mg/kg) was blocked by pretreatment
with WAY 100635 (0.1 mg/kg), a selective 5-HT(1A) receptor antagonist, but it was
not blocked by pretreatment with GR 127935 (0.056 mg/kg), a selective 5-HT(1B/1D)
receptor antagonist. The effect of CP 94,253 (1.0 mg/kg) was blocked by
pretreatment with GR 127935 (0.056 mg/kg) but was not blocked by pretreatment
with WAY 100635 (0.1 mg/kg). Neither WAY 100635 nor GR 127935 altered
extracellular 5-HT levels at the doses that were able to completely block the
effects of either 8-OH-PIPAT or CP 94,253. The present findings suggest that, on
systemic administration, both 8-OH-PIPAT and CP 94,253 are potent and selective
agonists at the somatodendritic 5-HT(1A) autoreceptor and terminal 5-HT(1B/1D)
autoreceptor, respectively, and are each able to cause decreases in extracellular
levels of 5-HT in the mouse striatum by activating a distinct set of receptors.
PMID- 10688631
TI - Quantitative prediction of metabolic inhibition of midazolam by erythromycin,
diltiazem, and verapamil in rats: implication of concentrative uptake of
inhibitors into liver.
AB - To evaluate the degree of drug-drug interaction concerning metabolic inhibition
in the liver quantitatively, we tried to predict the plasma concentration
increasing ratio (R) of midazolam (MDZ) by erythromycin (EM), diltiazem (DLZ), or
verapamil (VER) in rats. MDZ was administered through the portal vein at the
steady state of plasma concentration of these inhibitors. The R values in the
area under the plasma concentration curve of MDZ in the presence of EM, DLZ, and
VER were 2.02, 1.64, and 1.30, respectively. The liver to plasma unbound
concentration ratios of EM, DLZ, and VER at the steady state after infusion were
20.8, 1.02, and 3.01, respectively, suggesting concentrative uptake of EM and VER
into the liver. The predicted R value in the presence of EM calculated by use of
plasma unbound concentration was 1.03, whereas the value calculated with liver
unbound concentration was 1.61, which was very close to the observed value. These
findings indicated the need to consider the concentrative uptake of inhibitors
into the liver for the quantitative prediction of metabolic inhibition. However,
the predicted values in the presence of DLZ or VER calculated by use of liver
unbound concentration were still underestimated. This result may be due to the
metabolic inhibition by the metabolites of both inhibitors. Therefore, when
predicting the degree of metabolic inhibition quantitatively, the inhibitory
effect by coadministered drugs and the disposition of these metabolites in the
liver must also be considered.
PMID- 10688632
TI - Ligand-induced changes in surface mu-opioid receptor number: relationship to G
protein activation?
AB - In this study, we explored the relationship between regulation of surface mu
opioid receptor number, ligand-induced G protein activation (measured by
[(35)]S]guanosine-5'-O-(3-thio)triphosphate (GTPgammaS) binding) and second
messenger signaling (measured by the inhibition of cAMP accumulation). Etorphine
and two isomers of cis-beta-hydroxy-3-methylfentanyl (RTI-1a and RTI-1b), which
were full agonists for G protein activation and signaling, caused approximately a
50% loss of surface receptors after 1 h of treatment. Fentanyl and morphine were
full agonists for inhibiting cAMP accumulation and partial agonists for
stimulating [(35)S]GTPgammaS binding and internalization. Although both agonists
were approximately 80% as efficacious as etorphine in stimulating
[(35)S]GTPgammaS binding, fentanyl induced a 35% loss of surface receptors,
whereas morphine only caused a 10% loss. Additionally, both long- and short-term
treatment with the opioid antagonist naloxone caused increases in surface
receptors. Unexpectedly, the weak partial agonists buprenorphine and one isomer
of cis-beta-hydroxy-3-methylfentanyl (RTI-1d) also were found to cause an
increase in surface receptors. Treatment with pertussis toxin (PTX) diminished
agonist-induced loss of surface receptors. Furthermore, the abilities of morphine
and fentanyl to cause internalization were more impaired after PTX treatment than
that of etorphine. PTX treatment also significantly enhanced the increase in
surface receptor number caused by 18-h treatment with naloxone and buprenorphine.
The results of this study suggest that disruption of G protein coupling by PTX
treatment affects ligand-regulated mu-receptor trafficking and that partial
agonists for signaling can vary greatly in the ability to regulate the number of
surface mu-opioid receptors.
PMID- 10688633
TI - Imidazoline-binding domains on monoamine oxidase B and subpopulations of enzyme.
AB - A series of phenoxy-substituted methylimidazoline derivatives were synthesized
and used to define the ligand recognition properties of the imidazoline-binding
domain (IBD) on monoamine oxidase (MAO)-B and its role in substrate processing.
The rank order of potency for selected compounds in competitive binding studies
with the imidazoline [(3)H]idazoxan was different from that in enzyme activity
assays, suggesting that the IBD and the site involved in enzyme inhibition are
distinct. IC(50) values for inhibition of MAO-B activity by
imidazoline/guanidinium ligands were one to two orders of magnitude greater than
ligand concentrations that probably saturate the IBD, but were equal to the K(d)
values of these ligands in competitive binding assays with the reversible MAO-B
inhibitor [(3)H]Ro 19-6327. In addition, the degree of enzyme inhibition by these
ligands was similar in platelet and liver, tissues exhibiting 10-fold differences
in the amount of the IBD-accessible enzyme subpopulation. These data suggested
that the inhibitory effect of these compounds on MAO-B activity involved a
secondary interaction with the enzyme domain recognizing the inhibitor Ro 19-6327
and does not involve interaction with the IBD. Subsequent radioligand-binding
studies indicated that human liver MAO-B actually existed as two distinct
populations that differed in the accessibility of their IBD. The relatively small
amounts of MAO-B possessing an accessible IBD ( approximately 5% in human liver)
precludes determination of the functional consequences of ligand binding to the
IBD. This subpopulation of MAO-B may be selectively regulated or generated in
different individuals or tissues and targeted by pharmacologically active
compounds in a cell type-specific manner.
PMID- 10688634
TI - Kinetic and selectivity differences between rodent, rabbit, and human organic
cation transporters (OCT1).
AB - Organic cation transporters play an important role in the absorption,
distribution, and elimination of clinical agents, toxic substances, and
endogenous compounds. In kidney preparations, significant differences in
functional characteristics of organic cation transport between various species
have been reported. However, the underlying molecular mechanisms responsible for
these interspecies differences are not known. The goal of this study was to
determine the kinetics and substrate selectivities of organic cation transporter
(OCT1) homologs from mouse, rat, rabbit, and human that may contribute to
interspecies differences in the renal and hepatic handling of organic cations.
With a series of n-tetraalkylammonium (nTAA) compounds, a correlation between
increasing alkyl chain length and affinity for the four OCT1 homologs was
observed. However, the apparent affinity constants (K(i)) differed among the
species homologs. For the mouse homolog mOCT1, apparent K(i) values ranged from 7
microM for tetrabutylammonium to 2000 microM for tetramethylammonium. In
contrast, the human homolog hOCT1 exhibited weaker interactions with the nTAA
compounds. Trans-stimulation studies and current measurements in voltage-clamped
oocytes demonstrated that larger nTAA compounds were transported at greater rates
in oocytes expressing hOCT1, whereas smaller nTAAs were transported at greater
rates in oocytes expressing mOCT1 or rOCT1. The rabbit homolog rbOCT1 exhibited
intermediate properties in its interactions with nTAAs compared with its rodent
and human counterparts. This report demonstrates that the human OCT1 homolog has
functional properties distinct from those of the rodent and rabbit OCT1 homologs.
The study underscores potential difficulties in extrapolating data from
preclinical studies in animal models to humans.
PMID- 10688635
TI - Cytochrome P450 omega/omega-1 hydroxylase-derived eicosanoids contribute to
endothelin(A) and endothelin(B) receptor-mediated vasoconstriction to endothelin
1 in the rat preglomerular arteriole.
AB - The preglomerular arteriole of the rat was used to evaluate the contribution of
cytochrome P450-derived eicosanoids to the vasoconstrictor effect of endothelin
(ET)-1 and to determine the receptors mediating the response. ET-1 (4 x 10(-11)
to 2 x 10(-9) M) produced dose-dependent reductions in the intraluminal diameter
of the renal arteriole ranging from 25 +/- 8 to 142 +/- 16 micrometer. BMS182874
[(5-dimethylamino)-N-(3, 4-dimethyl-5-isoxazolyl)-1-naphthalenesulfonamide; 3
microM], an ET(A) receptor antagonist, or BQ788 (N-cis-2, 6-dimethyl-piperidino
carbonyl-L-gamma-methylleucyl-D-1-methoxy carbonyl-tryptophanyl-D-norleucine; 1
microM), an ET(B) receptor antagonist, attenuated ET-1 vasoconstriction by 59 +/-
4 and 50 +/- 10%, respectively. The combined administration of both ET receptor
antagonists increased inhibition of ET-1 vasoconstriction to 75 +/- 4%. 17
Octadecynoic acid (17-ODYA, 2 microM) or 12, 12-dibromododec-enoic acid (2
microM), inhibitors of 20-hydroxyeicosatetraenoic acid (20-HETE) production,
attenuated ET-1-induced vasoconstriction by 50 +/- 6 and 40 +/- 3%, respectively,
as did indomethacin (10 microM), an inhibitor of cyclooxygenase. Miconazole (2
microM), the epoxygenase inhibitor, was without effect. 20-HETE (10(-8) and 2 x
10(-8) M) elicited a dose-related vasoconstriction that was inhibited by 10
microM, but not 5 microM, indomethacin. The inhibition by 17-ODYA of ET-1
vasoconstriction was not greater when combined with BMS182874 or BQ788. Moreover,
vasoconstriction induced by ET-3, an ET(B)-selective agonist, was inhibited by 17
ODYA. These data indicate that both ET(A) and ET(B) receptors mediate ET-1
vasoconstriction and that 20-HETE production linked to both receptors makes a
major contribution to ET-1-induced renal arteriolar vasoconstriction in the rat.
PMID- 10688636
TI - Effects of selective and unselective cyclooxygenase inhibitors on prostanoid
release from various rat organs.
AB - It has been assumed that cyclooxygenase-2 (COX-2) is solely responsible for
inflammatory processes. Recently, this view has been challenged because COX-2
selective agents caused a delay of gastric ulcer healing and exacerbation of
inflammation in rats. To further characterize organ-specific toxic effects of
selective and nonselective COX inhibitors, we assessed the eicosanoid release
from different rat organs ex vivo after oral administration of the COX-2
selective inhibitor NS-398 and the unselective COX inhibitors diclofenac,
meloxicam, and ketorolac. Prostanoid and leukotriene release from tissue
fragments of the stomach, kidney, lung, and brain were determined after ex vivo
incubation of tissue fragments in Tyrode's solution for 10 min at 37 degrees C.
Ketorolac (0.1, 0.3, and 0.9 mg/kg) inhibited prostanoid release from all organs
most potently and led to a significant increase of leukotriene release from the
lung. Effects of diclofenac and meloxicam (1, 3, and 9 mg/kg each) were similar
for all organs tested. At 9 mg/kg, 6keto-prostaglandin F (PGF)(1alpha) release
from gastric mucosa was reduced by 79.1 +/- 11.4 and 87.6 +/- 7.7% and PGE(2)
release from rat kidney was inhibited by 60.4 +/- 6.8 and 78.6 +/- 16.6% by
diclofenac and meloxicam, respectively. NS-398 did not reduce prostanoid release
from the lung. Consistent with the reported constitutive expression of COX-2,
prostanoid release from kidney and brain was reduced by 20 to 30%. The release of
6keto-PGF(1alpha) from gastric mucosa was reduced by 34.7 +/- 22.2% at 3 mg/kg
and by 86.9 +/- 12.7% at 9 mg/kg. At these doses, NS-398 has been previously
shown to be COX-2 selective. Because PGF(1alpha) is the stable breakdown product
of PGI(2), these results suggest that COX-2 contributes to PGI(2) synthesis in
the rat stomach.
PMID- 10688637
TI - Native N-methyl-D-aspartate receptors containing NR2A and NR2B subunits have
pharmacologically distinct competitive antagonist binding sites.
AB - The pharmacological properties of native N-methyl-D-aspartate (NMDA) receptors
were determined in rat brain sections with quantitative autoradiography of
[(3)H](E)-2-amino-4-propyl-5-phosphono-3-pentenoic acid (CGP39653) binding. With
five competitive antagonists as displacers, two subpopulations of binding sites
were observed in the horizontal plane of section examined. These two populations
corresponded anatomically to NR2A and NR2B subunits. Quantitative analysis of
NR2A-like and NR2B-like binding sites was enabled by examining the cerebellar
granule cell layer, which expresses NR2A and NR2C subunits, and the medial
striatum, which predominately expresses NR2B subunits. The antagonists (R)-(E)-4
(3-phosphonoprop-2-enyl)piperazine-2-carboxylic acid and (R)-2-amino-5
phosphonopentanoate (D-AP5) displayed similar affinities at cerebellar NMDA
receptors and medial striatal NMDA receptors. In contrast, the NMDA receptor
antagonists (+/-)-6-(1H-Tetrazol-5-ylmethyl)decahydroisoquinoline- 3-carboxylic
acid, (S)-alpha-amino-5-(phosphonomethyl)[1,1'-biphenyl]-3-propanoic acid, and
(+/-)-cis-4-(4-phenylbenzoyl) piperazine-2,3-dicarboxylic acid displayed varied,
higher affinities at medial striatal NMDA receptors than at cerebellar NMDA
receptors. For the five antagonists, there was a strong correlation (r = 0.9)
between the cerebellar K(i)/medial striatum K(i) ratio and the NR2A K(i)/NR2B
K(i) ratio for recombinant receptors. Thus, [(3)H]CGP39653 labels two
pharmacologically distinct populations of NMDA receptors that have
pharmacological and anatomical properties consistent with NR2A and NR2B subunits.
Because native NR2A- and NR2B-containing receptors are pharmacologically
distinct, it should be possible to develop NR2A- and NR2B-selective glutamate
site antagonists.
PMID- 10688638
TI - ATP-dependent chromatin-remodeling complexes.
PMID- 10688639
TI - BSAP can repress enhancer activity by targeting PU.1 function.
AB - PU.1 and BSAP are transcription factors crucial for proper B-cell development.
Absence of PU.1 results in loss of B, T, and myeloid cells, while absence of BSAP
results in an early block in B-cell differentiation. Both of these proteins bind
to the immunoglobulin kappa chain 3' enhancer, which is developmentally regulated
during B-cell differentiation. We find here that BSAP can repress 3' enhancer
activity. This repression can occur in plasmacytoma lines or in a non-B-cell line
in which the enhancer is activated by addition of the appropriate enhancer
binding transcription factors. We show that the transcription factor PU.1 is a
target of the BSAP-mediated repression. Although PU.1 and BSAP can physically
interact through their respective DNA binding domains, this interaction does not
affect DNA binding. When PU.1 function is assayed in isolation on a multimerized
PU.1 binding site, BSAP targets a portion of the PU.1 transactivation domain
(residues 7 to 30) for repression. The BSAP inhibitory domain (residues 358 to
385) is needed for this repression. Interestingly, the coactivator protein p300
can eliminate this BSAP-mediated repression. We also show that PU.1 can inhibit
BSAP transactivation and that this repression requires PU.1 amino acids 7 to 30.
Transfection of p300 resulted in only a partial reversal of PU.1-mediated
repression of BSAP. When PU.1 function is assayed in the context of the
immunoglobulin kappa chain 3' enhancer and associated binding proteins, BSAP
represses PU.1 function by a distinct mechanism. This repression does not require
the PU.1 transactivation or PEST domains and cannot be reversed by p300
expression. The possible roles of BSAP and PU.1 antagonistic activities in
hematopoietic development are discussed.
PMID- 10688640
TI - Acetyl coenzyme A stimulates RNA polymerase II transcription and promoter binding
by transcription factor IID in the absence of histones.
AB - Protein acetylation has emerged as a means of controlling levels of mRNA
synthesis in eukaryotic cells. Here we report that acetyl coenzyme A (acetyl-CoA)
stimulates RNA polymerase II transcription in vitro in the absence of histones.
The effect of acetyl-CoA on basal and activated transcription was studied in a
human RNA polymerase II transcription system reconstituted from recombinant and
highly purified transcription factors. Both basal and activated transcription
were stimulated by the addition of acetyl-CoA to transcription reaction mixtures.
By varying the concentrations of general transcription factors in the reaction
mixtures, we found that acetyl-CoA decreased the concentration of TFIID required
to observe transcription. Electrophoretic mobility shift assays and DNase I
footprinting revealed that acetyl-CoA increased the affinity of the general
transcription factor TFIID for promoter DNA in a TBP-associated factor (TAF)
dependent manner. Interestingly, acetyl-CoA also caused a conformational change
in the TFIID-TFIIA-promoter complex as assessed by DNase I footprinting. These
results show that acetyl-CoA alters the DNA binding activity of TFIID and
indicate that this biologically important cofactor functions at multiple levels
to control gene expression.
PMID- 10688642
TI - The Est1 subunit of yeast telomerase binds the Tlc1 telomerase RNA.
AB - Est1 is a component of yeast telomerase, and est1 mutants have senescence and
telomere loss phenotypes. The exact function of Est1 is not known, and it is not
homologous to components of other telomerases. We previously showed that Est1
protein coimmunoprecipitates with Tlc1 (the telomerase RNA) as well as with
telomerase activity. Est1 has homology to Ebs1, an uncharacterized yeast open
reading frame product, including homology to a putative RNA recognition motif
(RRM) of Ebs1. Deletion of EBS1 results in short telomeres. We created point
mutations in a putative RRM of Est1. One mutant was unable to complement either
the senescence or the telomere loss phenotype of est1 mutants. Furthermore, the
mutant protein no longer coprecipitated with the Tlc1 telomerase RNA. Mutants
defective in the binding of Tlc1 RNA were nevertheless capable of binding single
stranded TG-rich DNA. Our data suggest that an important role of Est1 in the
telomerase complex is to bind to the Tlc1 telomerase RNA via an RRM. Since Est1
can also bind telomeric DNA, Est1 may tether telomerase to the telomere.
PMID- 10688641
TI - Nerve growth factor activation of the extracellular signal-regulated kinase
pathway is modulated by Ca(2+) and calmodulin.
AB - Nerve growth factor is a member of the neurotrophin family of trophic factors
that have been reported to be essential for the survival and development of
sympathetic neurons and a subset of sensory neurons. Nerve growth factor exerts
its effects mainly by interaction with the specific receptor TrkA, which leads to
the activation of several intracellular signaling pathways. Once activated, TrkA
also allows for a rapid and moderate increase in intracellular calcium levels,
which would contribute to the effects triggered by nerve growth factor in
neurons. In this report, we analyzed the relationship of calcium to the
activation of the Ras/extracellular signal-regulated kinase pathway in PC12
cells. We observed that calcium and calmodulin are both necessary for the acute
activation of extracellular signal-regulated kinases after TrkA stimulation. We
analyzed the elements of the pathway that lead to this activation, and we
observed that calmodulin antagonists completely block the initial Raf-1
activation without affecting the function of upstream elements, such as Ras,
Grb2, Shc, and Trk. We have broadened our study to other stimuli that activate
extracellular signal-regulated kinases through tyrosine kinase receptors, and we
have observed that calmodulin also modulates the activation of such kinases after
epidermal growth factor receptor stimulation in PC12 cells and after TrkB
stimulation in cultured chicken embryo motoneurons. Calmodulin seems to regulate
the full activation of Raf-1 after Ras activation, since functional Ras is
necessary for Raf-1 activation after nerve growth factor stimulation and
calmodulin-Sepharose is able to precipitate Raf-1 in a calcium-dependent manner.
PMID- 10688643
TI - Rap1 is a potent activation signal for leukocyte function-associated antigen 1
distinct from protein kinase C and phosphatidylinositol-3-OH kinase.
AB - To identify the intracellular signals which increase the adhesiveness of
leukocyte function-associated antigen 1 (LFA-1), we established an assay system
for activation-dependent adhesion through LFA-1/intercellular adhesion molecule 1
ICAM-1 using mouse lymphoid cells reconstituted with human LFA-1 and then
introduced constitutively active forms of signaling molecules. We found that the
phorbol myristate acetate (PMA)-responsive protein kinase C (PKC) isotypes
(alpha, betaI, betaII, and delta) or phosphatidylinositol-3-OH kinase (PI 3
kinase) itself activated LFA-1 to bind ICAM-1. H-Ras and Rac activated LFA-1 in a
PI 3-kinase-dependent manner, whereas Rho and R-Ras had little effect.
Unexpectedly, Rap1 was demonstrated to function as the most potent activator of
LFA-1. Distinct from H-Ras and Rac, Rap1 increased the adhesiveness independently
of PI 3-kinase, indicating that Rap1 is a novel activation signal for the
integrins. Rap1 induced changes in the conformation and affinity of LFA-1 and,
interestingly, caused marked LFA-1/ICAM-1-mediated cell aggregation. Furthermore,
a dominant negative form of Rap1 (Rap1N17) inhibited T-cell receptor-mediated LFA
1 activation in Jurkat T cells and LFA-1/ICAM-1-dependent cell aggregation upon
differentiation of HL-60 cells into macrophages, suggesting that Rap1 is
critically involved in physiological processes. These unique functions of Rap1 in
controlling cellular adhesion through LFA-1 suggest a pivotal role as an
immunological regulator.
PMID- 10688644
TI - Regulation of the resident chromosomal copy of c-myc by c-Myb is involved in
myeloid leukemogenesis.
AB - c-myb is a frequent target of retroviral insertional mutagenesis in murine
leukemia virus-induced myeloid leukemia. Induction of the leukemogenic phenotype
is generally associated with inappropriate expression of this transcriptional
regulator. Despite intensive investigations, the target genes of c-myb that are
specifically involved in development of these myeloid lineage neoplasms are still
unknown. In vitro assays have indicated that c-myc may be a target gene of c-Myb;
however, regulation of the resident chromosomal gene has not yet been
demonstrated. To address this question further, we analyzed the expression of c
myc in a myeloblastic cell line, M1, expressing a conditionally active c-Myb
estrogen receptor fusion protein (MybER). Activation of MybER both prevented the
growth arrest induced by interleukin-6 (IL-6) and rapidly restored c-myc
expression in nearly terminal differentiated cells that had been exposed to IL-6
for 3 days. Restoration occurred in the presence of a protein synthesis inhibitor
but not after a transcriptional block, indicating that c-myc is a direct,
transcriptionally regulated target of c-Myb. c-myc is a major target that
transduces Myb's proliferative signal, as shown by the ability of a c-Myc
estrogen receptor fusion protein alone to also reverse growth arrest in this
system. To investigate the possibility that this regulatory connection
contributes to Myb's oncogenicity, we expressed a dominant negative Myb in the
myeloid leukemic cell line RI-4-11. In this cell line, c-myb is activated by
insertional mutagenesis and cannot be effectively down regulated by cytokine.
Myb's ability to regulate c-myc's expression was also demonstrated in these
cells, showing a mechanism through which the proto-oncogene c-myb can exert its
oncogenic potential in myeloid lineage hematopoietic cells.
PMID- 10688645
TI - An AU-rich sequence element (UUUN[A/U]U) downstream of the edited C in
apolipoprotein B mRNA is a high-affinity binding site for Apobec-1: binding of
Apobec-1 to this motif in the 3' untranslated region of c-myc increases mRNA
stability.
AB - Apobec-1, the catalytic subunit of the mammalian apolipoprotein B (apoB) mRNA
editing enzyme, is a cytidine deaminase with RNA binding activity for AU-rich
sequences. This RNA binding activity is required for Apobec-1 to mediate C-to-U
RNA editing. Filter binding assays, using immobilized Apobec-1, demonstrate
saturable binding to a 105-nt apoB RNA with a K(d) of approximately 435 nM. A
series of AU-rich templates was used to identify a high-affinity ( approximately
50 nM) binding site of consensus sequence UUUN[A/U]U, with multiple copies of
this sequence constituting the high-affinity binding site. In order to determine
whether this consensus site could be functionally demonstrated from within an
apoB RNA, circular-permutation analysis was performed, revealing one major
(UUUGAU) and one minor (UU) site located 3 and 16 nucleotides, respectively,
downstream of the edited base. Secondary-structure predictions reveal a stem-loop
flanking the edited base with Apobec-1 binding to the consensus site(s) at an
open loop. A similar consensus (AUUUA) is present in the 3' untranslated regions
of several mRNAs, including that of c-myc, that are known to undergo rapid
degradation. In this context, it is presumed that the consensus motif acts as a
destabilizing element. As an independent test of the ability of Apobec-1 to bind
to this sequence, F442A cells were transfected with Apobec-1 and the half-life of
c-myc mRNA was determined following actinomycin D treatment. These studies
demonstrated an increase in the half-life of c-myc mRNA from 90 to 240 min in
control versus Apobec-1-expressing cells. Apobec-1 expression mutants, in which
RNA binding activity is eliminated, failed to alter c-myc mRNA turnover. Taken
together, the data establish a consensus binding site for Apobec-1 embedded in
proximity to the edited base in apoB RNA. Binding to this site in other target
RNAs raises the possibility that Apobec-1 may be involved in other aspects of RNA
metabolism, independent of its role as an apoB RNA-specific cytidine deaminase.
PMID- 10688646
TI - Loading of DNA-binding factors to an erythroid enhancer.
AB - The HS-40 enhancer is the major cis-acting regulatory element responsible for the
developmental stage- and erythroid lineage-specific expression of the human alpha
like globin genes, the embryonic zeta and the adult alpha2/alpha/1. A model has
been proposed in which competitive factor binding at one of the HS-40 motifs, 3'
NA, modulates the capability of HS-40 to activate the embryonic zeta-globin
promoter. Furthermore, this modulation was thought to be mediated through
configurational changes of the HS-40 enhanceosome during development. In this
study, we have further investigated the molecular basis of this model. First,
human erythroid K562 cells stably integrated with various HS-40 mutants cis
linked to a human alpha-globin promoter-growth hormone hybrid gene were analyzed
by genomic footprinting and expression analysis. By the assay, we demonstrate
that factors bound at different motifs of HS-40 indeed act in concert to build a
fully functional enhanceosome. Thus, modification of factor binding at a single
motif could drastically change the configuration and function of the HS-40
enhanceosome. Second, a specific 1-bp, GC-->TA mutation in the 3'-NA motif of HS
40, 3'-NA(II), has been shown previously to cause significant derepression of the
embryonic zeta-globin promoter activity in erythroid cells. This derepression was
hypothesized to be regulated through competitive binding of different nuclear
factors, in particular AP1 and NF-E2, to the 3'-NA motif. By gel mobility shift
and transient cotransfection assays, we now show that 3'-NA(II) mutation
completely abolishes the binding of small MafK homodimer. Surprisingly, NF-E2 as
well as AP1 can still bind to the 3'-NA(II) sequence. The association constants
of both NF-E2 and AP1 are similar to their interactions with the wild-type 3'-NA
motif. However, the 3'-NA(II) mutation causes an approximately twofold reduction
of the binding affinity of NF-E2 factor to the 3'-NA motif. This reduction of
affinity could be accounted for by a twofold-higher rate of dissociation of the
NF-E2-3'-NA(II) complex. Finally, we show by chromatin immunoprecipitation
experiments that only binding of NF-E2, not AP1, could be detected in vivo in
K562 cells around the HS-40 region. These data exclude a role for AP1 in the
developmental regulation of the human alpha-globin locus via the 3'-NA motif of
HS-40 in embryonic/fetal erythroid cells. Furthermore, extrapolation of the in
vitro binding studies suggests that factors other than NF-E2, such as the small
Maf homodimers, are likely involved in the regulation of the HS-40 function in
vivo.
PMID- 10688647
TI - Recruitment of the SWI-SNF chromatin remodeling complex as a mechanism of gene
activation by the glucocorticoid receptor tau1 activation domain.
AB - The SWI-SNF complex has been shown to alter nucleosome conformation in an ATP
dependent manner, leading to increased accessibility of nucleosomal DNA to
transcription factors. In this study, we show that the SWI-SNF complex can
potentiate the activity of the glucocorticoid receptor (GR) through the N
terminal transactivation domain, tau1, in both yeast and mammalian cells. GR-tau1
can directly interact with purified SWI-SNF complex, and mutations in tau1 that
affect the transactivation activity in vivo also directly affect tau1 interaction
with SWI-SNF. Furthermore, the SWI-SNF complex can stimulate tau1-driven
transcription from chromatin templates in vitro. Taken together, these results
support a model in which the GR can directly recruit the SWI-SNF complex to
target promoters during glucocorticoid-dependent gene activation. We also provide
evidence that the SWI-SNF and SAGA complexes represent independent pathways of
tau1-mediated activation but play overlapping roles that are able to compensate
for one another under some conditions.
PMID- 10688648
TI - Pocket protein-independent repression of urokinase-type plasminogen activator and
plasminogen activator inhibitor 1 gene expression by E2F1.
AB - Expression of genes of the plasminogen activator (PA) system declines at the
G(0)/G(1)-S-phase boundary of the cell cycle. We found that overexpression of
E2F1-3, which acts mainly in late G(1), inhibits promoter activity and endogenous
expression of the urokinase-type PA (uPA) and PA inhibitor 1 (PAI-1) genes. This
effect is dose dependent and conserved in evolution. Mutation analysis indicated
that both the DNA-binding and transactivation domains of E2F1 are necessary for
this regulation. Interestingly, an E2F1 mutant lacking the pRB-binding region
strongly repressed the uPA and PAI-1 promoters. An E2F-mediated negative effect
was also observed in pRB and p107/p130 knockout cell lines. This is the first
report that E2F can act as a repressor independently of pocket proteins. Mutation
of AP-1 elements in the uPA promoter abrogated E2F-mediated transcriptional
inhibition, suggesting the involvement of AP-1 in this regulation. Results shown
here identify E2F as an important component of transcriptional control of the PA
system and thus provide new insights into mechanisms of cellular proliferation.
PMID- 10688649
TI - The p53 tumor suppressor protein does not regulate expression of its own
inhibitor, MDM2, except under conditions of stress.
AB - MDM2 is an important regulator of the p53 tumor suppressor protein. MDM2 inhibits
p53 by binding to it, physically blocking its ability to transactivate gene
expression, and stimulating its degradation. In cultured cells, mdm2 expression
can be regulated by p53. Hence, mdm2 and p53 can interact to form an
autoregulatory loop in which p53 activates expression of its own inhibitor. The
p53/MDM2 autoregulatory loop has been elucidated within cultured cells; however,
regulation of mdm2 expression by p53 has not been demonstrated within intact
tissues. Here, we examine the role of p53 in regulating mdm2 expression in vivo
in order to test the hypothesis that the p53/MDM2 autoregulatory loop is the
mechanism by which low levels of p53 are maintained. We demonstrate that basal
expression of mdm2 in murine tissues is p53 independent, even in tissues that
express functional p53. Transcription of mdm2 is induced in a p53-dependent
manner following gamma irradiation, indicating that p53 regulates mdm2 expression
in vivo following a stimulus. The requirement for a stimulus to activate p53
dependent regulation of mdm2 expression in vivo appeared to differ from the
situation in early-passage mouse embryo fibroblasts, where mdm2 expression is
enhanced by the presence of p53. Analysis of mdm2 expression in intact and
dispersed embryos revealed that establishment of mouse embryo fibroblasts in
culture induces p53-dependent mdm2 expression, suggesting that an unknown
stimulus activates p53 function in cultured cells. Together, these results
indicate that p53 does not regulate expression of its own inhibitor, except in
response to stimuli.
PMID- 10688650
TI - p300 requires its histone acetyltransferase activity and SRC-1 interaction domain
to facilitate thyroid hormone receptor activation in chromatin.
AB - We have characterized the mechanism by which coactivator p300 facilitates
transcriptional activation mediated by the heterodimer of thyroid hormone (T3)
receptor and 9-cis retinoid acid receptor (TR-RXR) in the context of chromatin.
We demonstrate that, while p300 can enhance the transcriptional activation
mediated by both liganded TR-RXR and GAL4-VP16, its histone acetyltransferase
activity (HAT) is required for its ability to facilitate liganded TR-RXR- but not
GAL4-VP16-mediated transcriptional activation. To understand how p300 is
recruited by liganded TR-RXR, we have analyzed the interactions between TR-RXR
and p300 as well as SRC-1 family coactivators. We show that, in contrast to a
strong hormone-dependent interaction between TR-RXR and SRC-1 family
coactivators, p300 displays minimal, if any, T3-dependent interaction with TR
RXR. However, p300 can be recruited by liganded TR-RXR through its interaction
with SRC-1 family coactivators. Consistent with the protein-protein interaction
profile described above, we demonstrate that the SRC-1 interaction domain of p300
is important for its ability to facilitate transcriptional activation mediated by
TR-RXR, whereas its nuclear receptor interaction domain is dispensable.
Collectively, these results reveal the functional significance of the HAT
activity of p300 and define an indirect mode for the action of p300 in TR-RXR
activation.
PMID- 10688651
TI - Etk, a Btk family tyrosine kinase, mediates cellular transformation by linking
Src to STAT3 activation.
AB - Etk (also called Bmx) is a member of the Btk tyrosine kinase family and is
expressed in a variety of hematopoietic, epithelial, and endothelial cells. We
have explored biological functions, regulators, and effectors of Etk.
Coexpression of v-Src and Etk led to a transphosphorylation on tyrosine 566 of
Etk and subsequent autophosphorylation. These events correlated with a
substantial increase in the kinase activity of Etk. STAT3, which was previously
shown to be activated by Etk, associated with Etk in vivo. To investigate whether
Etk could mediate v-Src-induced activation of STAT3 and cell transformation, we
overexpressed a dominant-negative mutant of Etk in an immortalized, untransformed
rat liver epithelial cell line, WB, which contains endogenous Etk. Dominant
negative inactivation of Etk not only blocked v-Src-induced tyrosine
phosphorylation and activation of STAT3 but also caused a great reduction in the
transforming activity of v-Src. In NIH3T3 cells, although Etk did not itself
induce transformation, it effectively enhanced the transforming ability of a
partially active c-Src mutant (c-Src378G). Furthermore, Etk activated STAT3
mediated gene expression in synergy with this Src mutant. Our findings thus
indicate that Etk is a critical mediator of Src-induced cell transformation and
STAT3 activation. The role of STAT3 in Etk-mediated transformation was also
examined. Expression of Etk in a human hepatoma cell line Hep3B resulted in a
significant increase in its transforming ability, and this effect was abrogated
by dominant-negative inhibition of STAT3. These data strongly suggest that Etk
links Src to STAT3 activation. Furthermore, Src-Etk-STAT3 is an important pathway
in cellular transformation.
PMID- 10688652
TI - Disassociation of met-mediated biological responses in vivo: the natural
hepatocyte growth factor/scatter factor splice variant NK2 antagonizes growth but
facilitates metastasis.
AB - Hepatocyte growth factor/scatter factor (HGF/SF) stimulates numerous cellular
activities capable of contributing to the metastatic phenotype, including growth,
motility, invasiveness, and morphogenetic transformation. When inappropriately
expressed in vivo, an HGF/SF transgene induces numerous hyperplastic and
neoplastic lesions. NK1 and NK2 are natural splice variants of HGF/SF; all
interact with a common receptor, Met. Although both agonistic and antagonistic
properties have been ascribed to each isoform in vitro, NK1 retains the full
spectrum of HGF/SF-like activities when expressed as a transgene in vivo. Here we
report that transgenic mice broadly expressing NK2 exhibit none of the phenotypes
characteristic of HGF/SF or NK1 transgenic mice. Instead, when coexpressed in NK2
HGF/SF bitransgenic mice, NK2 antagonizes the pathological consequences of HGF/SF
and discourages the subcutaneous growth of transplanted Met-containing melanoma
cells. Remarkably, the metastatic efficiency of these same melanoma cells is
dramatically enhanced in NK2 transgenic host mice relative to wild-type
recipients, rivaling levels achieved in HGF/SF and NK1 transgenic hosts.
Considered in conjunction with reports that in vitro NK2 induces scatter, but not
other activities, these data strongly suggest that cellular motility is a
critical determinant of metastasis. Moreover, our results demonstrate how
alternatively structured ligands can be exploited in vivo to functionally
dissociate Met-mediated activities and their downstream pathways.
PMID- 10688653
TI - RRS1, a conserved essential gene, encodes a novel regulatory protein required for
ribosome biogenesis in Saccharomyces cerevisiae.
AB - A secretory defect causes specific and significant transcriptional repression of
both ribosomal protein and rRNA genes (K. Mizuta and J. R. Warner, Mol. Cell.
Biol. 14:2493-2502, 1994), suggesting the coupling of plasma membrane and
ribosome syntheses. In order to elucidate the molecular mechanism of the
signaling pathway, we isolated a cold-sensitive mutant with a mutation in a gene
termed RRS1 (regulator of ribosome synthesis), which appeared to be defective in
the signaling pathway. The rrs1-1 mutation greatly reduced transcriptional
repression of both rRNA and ribosomal protein genes that is caused by a secretory
defect. RRS1 is a novel, essential gene encoding a nuclear protein of 203 amino
acid residues that is conserved in eukaryotes. A conditional rrs1-null mutant was
constructed by placing RRS1 under the control of the GAL1 promoter. Rrs1p
depletion caused defects in processing of pre-rRNA and assembly of ribosomal
subunits.
PMID- 10688654
TI - The ETO protein disrupted in t(8;21)-associated acute myeloid leukemia is a
corepressor for the promyelocytic leukemia zinc finger protein.
AB - The ETO protein was originally identified by its fusion to the AML-1
transcription factor in translocation (8;21) associated with the M2 form of acute
myeloid leukemia (AML). The resulting AML-1-ETO fusion is an aberrant
transcriptional regulator due to the ability of ETO, which does not bind DNA
itself, to recruit the transcriptional corepressors N-CoR, SMRT, and Sin3A and
histone deacetylases. The promyelocytic leukemia zinc finger (PLZF) protein is a
sequence-specific DNA-binding transcriptional factor fused to retinoic acid
receptor alpha in acute promyelocytic leukemia associated with the
(11;17)(q23;q21) translocation. PLZF also mediates transcriptional repression
through the actions of corepressors and histone deacetylases. We found that ETO
is one of the corepressors recruited by PLZF. The PLZF and ETO proteins associate
in vivo and in vitro, and ETO can potentiate transcriptional repression by PLZF.
The N-terminal portion of ETO forms complexes with PLZF, while the C-terminal
region, which was shown to bind to N-CoR and SMRT, is required for the ability of
ETO to augment transcriptional repression by PLZF. The second repression domain
(RD2) of PLZF, not the POZ/BTB domain, is necessary to bind to ETO. Corepression
by ETO was completely abrogated by histone deacetylase inhibitors. This
identifies ETO as a cofactor for a sequence-specific transcription factor and
indicates that, like other corepressors, it functions through the action of
histone deactylase.
PMID- 10688655
TI - ArgRII, a component of the ArgR-Mcm1 complex involved in the control of arginine
metabolism in Saccharomyces cerevisiae, is the sensor of arginine.
AB - Repression of arginine anabolic genes and induction of arginine catabolic genes
are mediated by a three-component protein complex, interacting with specific DNA
sequences in the presence of arginine. Although ArgRI and Mcm1, two MADS-box
proteins, and ArgRII, a zinc cluster protein, contain putative DNA binding
domains, alone they are unable to bind the arginine boxes in vitro. Using
purified glutathione S-transferase fusion proteins, we demonstrate that ArgRI and
ArgRII1-180 or Mcm1 and ArgRII1-180 are able to reconstitute an arginine
dependent binding activity in mobility shift analysis. Binding efficiency is
enhanced when the three recombinant proteins are present simultaneously. At
physiological concentration, the full-length ArgRII is required to fulfill its
functions; however, when ArgRII is overexpressed, the first 180 amino acids are
sufficient to interact with ArgRI, Mcm1, and arginine, leading to the formation
of an ArgR-Mcm1-DNA complex. Several lines of evidence indicate that ArgRII is
the sensor of the effector arginine and that the binding site of arginine would
be the region downstream from the zinc cluster, sharing some identity with the
arginine binding domain of bacterial arginine repressors.
PMID- 10688656
TI - The interaction between the Drosophila secreted protein argos and the epidermal
growth factor receptor inhibits dimerization of the receptor and binding of
secreted spitz to the receptor.
AB - Drosophila Argos (Aos), a secreted protein with an epidermal growth factor (EGF)
like domain, has been shown to inhibit the activation of the Drosophila EGF
receptor (DER). However, it has not been determined whether Aos binds directly to
DER or whether regulation of the DER activation occurs through some other
mechanism. Using DER-expressing cells (DER/S2) and a recombinant DER
extracellular domain-Fc fusion protein (DER-Fc), we have shown that Aos binds
directly to the extracellular domain of DER with its carboxyl-terminal region,
including the EGF-like domain. Furthermore, Aos can block the binding of secreted
Spitz (sSpi), a transforming growth factor alpha-like ligand of DER, to the
extracellular domain of DER. We observed that sSpi stimulates the dimerization of
both the soluble DER extracellular domain (sDER) and the intact DER in the DER/S2
cells and that Aos can block the sSpi-induced dimerization of both sDER and
intact DER. Moreover, we have shown that, by directly interacting with DER, Aos
and SpiAos (a chimeric protein that is composed of the N-terminal region of Spi
and the C-terminal region of Aos) inhibit the dimerization and phosphorylation of
DER that are induced by DER's overexpression in the absence of sSpi. These
results indicate that Aos exerts its inhibitory function through dual molecular
mechanisms: by blocking both the receptor dimerization and the binding of
activating ligand to the receptor. This is the first description of this novel
inhibitory mechanism for receptor tyrosine kinases.
PMID- 10688657
TI - Cloning of a mammalian transcriptional activator that binds unmethylated CpG
motifs and shares a CXXC domain with DNA methyltransferase, human trithorax, and
methyl-CpG binding domain protein 1.
AB - Ligand screening was utilized to isolate a human cDNA that encodes a novel CpG
binding protein, human CpG binding protein (hCGBP). This factor contains three
cysteine-rich domains, two of which exhibit homology to the plant homeodomain
finger domain. A third cysteine-rich domain conforms to the CXXC motif identified
in DNA methyltransferase, human trithorax, and methyl-CpG binding domain protein
1. A fragment of hCGBP that contains the CXXC domain binds to an oligonucleotide
probe containing a single CpG site, and this complex is disrupted by distinct
oligonucleotide competitors that also contain a CpG motif(s). However, hCGBP
fails to bind oligonucleotides in which the CpG motif is either mutated or
methylated, and it does not bind to single-stranded DNA or RNA probes.
Furthermore, the introduction of a CpG dinucleotide into an unrelated
oligonucleotide sequence is sufficient to produce a binding site for hCGBP.
Native hCGBP is detected as an 88-kDa protein by Western analysis and is
ubiquitously expressed. The DNA-binding activity of native hCGBP is apparent in
electrophoretic mobility shift assays, and hCGBP trans-activates promoters that
contain CpG motifs but not promoters in which the CpG is ablated. These data
indicate that hCGBP is a transcriptional activator that recognizes unmethylated
CpG dinucleotides, suggesting a role in modulating the expression of genes
located within CpG islands.
PMID- 10688658
TI - Normal spermatogenesis in mice lacking the testis-specific linker histone H1t.
AB - H1 histones bind to linker DNA and nucleosome core particles and facilitate the
folding of chromatin into a more compact structure. Mammals contain seven
nonallelic subtypes of H1, including testis-specific subtype H1t, which varies
considerably in primary sequence from the other H1 subtypes. H1t is found only in
pachytene spermatocytes and early, haploid spermatids, constituting as much as
55% of the linker histone associated with chromatin in these cell types. To
investigate the role of H1t in spermatogenesis, we disrupted the H1t gene by
homologous recombination in mouse embryonic stem cells. Mice homozygous for the
mutation and completely lacking H1t protein in their germ cells were fertile and
showed no detectable defect in spermatogenesis. Chromatin from H1t-deficient germ
cells had a normal ratio of H1 to nucleosomes, indicating that other H1 subtypes
are deposited in chromatin in place of H1t and presumably compensate for most or
all H1t functions. The results indicate that despite the unique primary structure
and regulated synthesis of H1t, it is not essential for proper development of
mature, functional sperm.
PMID- 10688659
TI - Rapid deadenylation and Poly(A)-dependent translational repression mediated by
the Caenorhabditis elegans tra-2 3' untranslated region in Xenopus embryos.
AB - The 3' untranslated region (3'UTR) of many eukaryotic mRNAs is essential for
their control during early development. Negative translational control elements
in 3'UTRs regulate pattern formation, cell fate, and sex determination in a
variety of organisms. tra-2 mRNA in Caenorhabditis elegans is required for female
development but must be repressed to permit spermatogenesis in hermaphrodites.
Translational repression of tra-2 mRNA in C. elegans is mediated by tandemly
repeated elements in its 3'UTR; these elements are called TGEs (for tra-2 and GLI
element). To examine the mechanism of TGE-mediated repression, we first
demonstrate that TGE-mediated translational repression occurs in Xenopus embryos
and that Xenopus egg extracts contain a TGE-specific binding factor.
Translational repression by the TGEs requires that the mRNA possess a poly(A)
tail. We show that in C. elegans, the poly(A) tail of wild-type tra-2 mRNA is
shorter than that of a mutant mRNA lacking the TGEs. To determine whether TGEs
regulate poly(A) length directly, synthetic tra-2 3'UTRs with and without the
TGEs were injected into Xenopus embryos. We find that TGEs accelerate the rate of
deadenylation and permit the last 15 adenosines to be removed from the RNA,
resulting in the accumulation of fully deadenylated molecules. We conclude that
TGE-mediated translational repression involves either interference with poly(A)'s
function in translation and/or regulated deadenylation.
PMID- 10688660
TI - E1A-mediated repression of progesterone receptor-dependent transactivation
involves inhibition of the assembly of a multisubunit coactivation complex.
AB - The steroid hormone progesterone acts via high-affinity nuclear receptors that
interact with specific DNA sequences located near the promoter of the hormone
responsive gene. Recent studies suggested that the hormone-occupied progesterone
receptor (PR) mediates gene activation by recruiting a cellular coregulatory
factor, termed coactivator, to the target promoter. The identity and mechanism of
action of the coactivator(s) that regulates transcriptional activity of PR are
currently under investigation. Here we provide evidence that the hormone-occupied
PR forms a multisubunit receptor-coactivator complex containing two previously
described coactivators, CREB-binding protein (CBP) and steroid receptor
coactivator 1 (SRC-1, a member of the p160 family of coactivators), in nuclear
extracts of human breast tumor T47D cells. The association of CBP and SRC-1/p160
with the receptor complex is entirely hormone dependent. Both CBP and SRC-1/p160
possess intrinsic histone acetyltransferase (HAT) activity, and it has been
recently proposed that these coactivators function by modulating chromatin
structure at the promoter of the target gene. Interestingly, addition of purified
CBP to the nuclear extracts of T47D cells markedly stimulated progesterone- and
PR-dependent transcription from a nucleosome-free, progesterone response element
(PRE)-linked reporter DNA template. Furthermore, depletion of SRC-1/p160 by
immunoprecipitation from these transcriptional extracts also significantly
impaired PR-mediated RNA synthesis from a naked PRE-linked DNA template. These
results strongly implied that CBP and SRC-1/p160 facilitate receptor-mediated
transcription in these cell extracts through mechanisms other than chromatin
remodeling. We also observed that the adenoviral oncoprotein E1A, which interacts
directly with CBP, repressed PR-mediated transactivation when added to the
nuclear extracts of T47D cells. Supplementation with purified CBP overcame this
inhibition, indicating that the inhibitory effect of E1A is indeed due to a
blockade of CBP function. Most importantly, we noted that binding of E1A to CBP
prevented the assembly of a coactivation complex containing PR, CBP, and SRC
1/p160, presumably by disrupting the interaction between CBP and SRC-1/p160.
These results strongly suggested that E1A repressed receptor-mediated
transcription by blocking the formation or recruitment of coactivation complexes.
Collectively, our results support the hypothesis that the assembly of a
multisubunit coactivation complex containing PR, CBP, and SRC-1/p160 is a
critical regulatory step during hormone-dependent gene activation by PR and that
the fully assembled complex has the ability to control transcription through
mechanisms that are independent of the histone-modifying activities of its
component coactivators.
PMID- 10688661
TI - Transcriptional repression by neuron-restrictive silencer factor is mediated via
the Sin3-histone deacetylase complex.
AB - A large number of neuron-specific genes characterized to date are under the
control of negative transcriptional regulation. Many promoter regions of neuron
specific genes possess the repressor element repressor element 1/neuron
restrictive silencing element (RE1/NRSE). Its cognate binding protein, REST/NRSF,
is an essential transcription factor; its null mutations result in embryonic
lethality, and its dominant negative mutants produce aberrant expression of
neuron-specific genes. REST/NRSF acts as a regulator of neuron-specific gene
expression in both nonneuronal tissue and developing neurons. Here, we shown that
heterologous expression of REST/NRSF in Saccharomyces cerevisiae is able to
repress transcription from yeast promoters engineered to contain RE1/NRSEs.
Moreover, we have taken advantage of this observation to show that this
repression requires both yeast Sin3p and Rpd3p and that REST/NRSF physically
interacts with the product of the yeast SIN3 gene in vivo. Furthermore, we show
that REST/NRSF binds mammalian SIN3A and HDAC-2 and requires histone deacetylase
activity to repress neuronal gene transcription in both nonneuronal and neuronal
cell lines. We show that REST/NRSF binding to RE1/NRSE is accompanied by a
decrease in the acetylation of histones around RE1/NRSE and that this decrease
requires the N-terminal Sin3p binding domain of REST/NRSF. Taken together, these
data suggest that REST/NRSF represses neuronal gene transcription by recruiting
the SIN3/HDAC complex.
PMID- 10688662
TI - The branch point enzyme of the mevalonate pathway for protein prenylation is
overexpressed in the ob/ob mouse and induced by adipogenesis.
AB - We have recently reported that skeletal muscle of the ob/ob mouse, an animal
model of genetic obesity with extreme insulin resistance, exhibits alterations in
the expression of multiple genes. Analysis and cloning of a full-length cDNA of
one of the overexpressed mRNAs revealed a 300-amino-acid protein that could be
identified as the mouse geranylgeranyl diphosphate synthase (GGPP synthase) based
on its homology to proteins cloned from yeast and fungus. GGPP synthase catalyzes
the synthesis of all-trans-geranylgeranyl diphosphate (GGPP), an isoprenoid used
for protein isoprenylation in animal cells, and is a branch point enzyme in the
mevalonic acid pathway. Three mRNAs for GGPP synthase of 4.3, 3.2, and 1.7 kb
were detected in Northern blot analysis. Western blot analysis of tissue
homogenates using specific antipeptide antibodies revealed a single band of 34.8
kDa. Expression level of this protein in different tissues correlated with
expression of the 4.3- and 3.2-kb mRNAs. GGPP synthase mRNA expression was
increased 5- to 20-fold in skeletal muscle, liver, and fat of ob/ob mice by
Northern blot analysis. Western blot analysis also showed a twofold
overexpression of the protein in muscle and fat but not in liver, where the
dominant isoform is encoded by the 1.7-kb mRNA. Differentiation of 3T3-L1
fibroblasts into adipocytes induced GGPP synthase expression more than 20-fold.
Using the immunoprecipitated protein, we found that mammalian GGPP synthase
synthesizes not only GGPP but also its metabolic precursor farnesyl diphosphate.
Thus, the expression of GGPP synthase is regulated in multiple tissues in obesity
and is induced during adipocyte differentiation. Altered regulation in the
synthesis of isoprenoids for protein prenylation in obesity might be a factor
determining the ability of the cells to respond to hormonal stimulation requiring
both Ras-related small GTPases and trimeric G protein-coupled receptors.
PMID- 10688663
TI - The H3-H4 N-terminal tail domains are the primary mediators of transcription
factor IIIA access to 5S DNA within a nucleosome.
AB - Reconstitution of a DNA fragment containing a Xenopus borealis somatic type 5S
rRNA gene into a nucleosome greatly restricts the binding of transcription factor
IIIA (TFIIIA) to its cognate DNA sequence within the internal promoter of the
gene. Removal of all core histone tail domains by limited trypsin proteolysis or
acetylation of the core histone tails significantly relieves this inhibition and
allows TFIIIA to exhibit high-affinity binding to nucleosomal DNA. Since only a
single tail or a subset of tails may be primarily responsible for this effect, we
determined whether removal of the individual tail domains of the H2A-H2B dimer or
the H3-H4 tetramer affects TFIIIA binding to its cognate DNA site within the 5S
nucleosome in vitro. The results show that the tail domains of H3 and H4, but not
those of H2A and/or H2B, directly modulate the ability of TFIIIA to bind
nucleosomal DNA. In vitro transcription assays carried out with nucleosomal
templates lacking individual tail domains show that transcription efficiency
parallels the binding of TFIIIA. In addition, we show that the stoichiometry of
core histones within the 5S DNA-core histone-TFIIIA triple complex is not changed
upon TFIIIA association. Thus, TFIIIA binding occurs by displacement of H2A-H2B
DNA contacts but without complete loss of the dimer from the nucleoprotein
complex. These data, coupled with previous reports (M. Vettese-Dadey, P. A.
Grant, T. R. Hebbes, C. Crane-Robinson, C. D. Allis, and J. L. Workman, EMBO J.
15:2508-2518, 1996; L. Howe, T. A. Ranalli, C. D. Allis, and J. Ausio, J. Biol.
Chem. 273:20693-20696, 1998), suggest that the H3/H4 tails are the primary
arbiters of transcription factor access to intranucleosomal DNA.
PMID- 10688664
TI - Functional Cus1p is found with Hsh155p in a multiprotein splicing factor
associated with U2 snRNA.
AB - To explore the dynamics of snRNP structure and function, we have studied Cus1p,
identified as a suppressor of U2 snRNA mutations in budding yeast. Cus1p is
homologous to human SAP145, a protein present in the 17S form of the human U2
snRNP. Here, we define the Cus1p amino acids required for function in yeast. The
segment of Cus1p required for binding to Hsh49p, a homolog of human SAP49, is
contained within an essential region of Cus1p. Antibodies against Cus1p
coimmunoprecipitate U2 snRNA, as well as Hsh155p, a protein homologous to human
SAP155. Biochemical fractionation of splicing extracts and reconstitution of heat
inactivated splicing extracts from strains carrying a temperature-sensitive
allele of CUS1 indicate that Cus1p and Hsh155p reside in a functional, high-salt
stable complex that is salt-dissociable from U2 snRNA. We propose that Cus1p,
Hsh49p, and Hsh155p exist in a stable protein complex which can exchange with a
core U2 snRNP and which is necessary for U2 snRNP function in prespliceosome
assembly. The Cus1p complex shares functional as well as structural similarities
with human SF3b.
PMID- 10688665
TI - Apoptotic and growth-promoting activity of E2F modulated by MDM2.
AB - E2F integrates and coordinates cell cycle progression with the transcription
apparatus through its cyclical interactions with important regulators of cellular
proliferation, such as pRb, cyclins, and cdk's. Physiological E2F is a
heterodimeric transcription factor composed of an E2F and a DP family member, and
while E2F proteins can stimulate proliferation, certain members of the family are
known to be endowed with growth-inhibitory and tumor suppressor-like activity. We
have investigated the product of the human mdm2 oncogene, hDM2, and report on its
ability to regulate E2F-dependent apoptosis in a fashion that is independent of
p53. hDM2 can prevent p53(-/-) cells from entering E2F-dependent apoptosis, an
outcome that is dependent upon the presence of the DP subunit. Cells rescued from
apoptosis possess lower levels of E2F subunits, although the rescued cells show
an increase in DNA synthesis and possess enhanced viability that reflects
cooperation between E2F-DP and hMD2. Furthermore, the regulation of E2F activity
correlates with an hDM2-dependent effect on the intracellular distribution of DP
1, since hDM2 causes the nuclear accumulation of DP-1. The control of E2F by hDM2
therefore has certain parallels with the targeted degradation by MDM2 of p53.
However, the domains in hDM2 required for the regulation of E2F activity can be
distinguished from those necessary for p53 degradation, suggesting that control
of E2F and p53 by hDM2 may be mechanistically distinct. These experiments define
a new level of interplay between E2F and hDM2 whereby hDM2 has a profound impact
on the physiological consequences of E2F activation. They suggest that the
oncogenic properties of hDM2 may in part be mediated by an antiapoptotic activity
that converts E2F from a negative to a positive regulator of cell cycle
progression and thereby retains E2F at a level that contributes to a continual
state of growth stimulation.
PMID- 10688666
TI - Activation of apoptosis signal-regulating kinase 1 (ASK1) by tumor necrosis
factor receptor-associated factor 2 requires prior dissociation of the ASK1
inhibitor thioredoxin.
AB - The stress-activated protein kinases (SAPKs, also called c-Jun NH(2)-terminal
kinases) and the p38s, two mitogen-activated protein kinase (MAPK) subgroups
activated by cytokines of the tumor necrosis factor (TNF) family, are pivotal to
the de novo gene expression elicited as part of the inflammatory response.
Apoptosis signal-regulating kinase 1 (ASK1) is a MAPK kinase kinase (MAP3K) that
activates both the SAPKs and p38s in vivo. Here we show that TNF receptor (TNFR)
associated factor 2 (TRAF2), an adapter protein that couples TNFRs to the SAPKs
and p38s, can activate ASK1 in vivo and can interact in vivo with the amino- and
carboxyl-terminal noncatalytic domains of the ASK1 polypeptide. Expression of the
amino-terminal noncatalytic domain of ASK1 can inhibit TNF and TRAF2 activation
of SAPK. TNF can stimulate the production of reactive oxygen species (ROS), and
the redox-sensing enzyme thioredoxin (Trx) is an endogenous inhibitor of ASK1. We
also show that expression of TRAF2 fosters the production of ROS in transfected
cells. We demonstrate that Trx significantly inhibits TRAF2 activation of SAPK
and blocks the ASK1-TRAF2 interaction in a reaction reversed by oxidants.
Finally, the mechanism of ASK1 activation involves, in part, homo
oligomerization. We show that expression of ASK1 with TRAF2 enhances in vivo ASK1
homo-oligomerization in a manner dependent, in part, upon the TRAF2 RING effector
domain and the generation of ROS. Thus, activation of ASK1 by TNF requires the
ROS-mediated dissociation of Trx possibly followed by the binding of TRAF2 and
consequent ASK1 homo-oligomerization.
PMID- 10688667
TI - Fourteen residues of the U1 snRNP-specific U1A protein are required for
homodimerization, cooperative RNA binding, and inhibition of polyadenylation.
AB - It was previously shown that the human U1A protein, one of three U1 small nuclear
ribonucleoprotein-specific proteins, autoregulates its own production by binding
to and inhibiting the polyadenylation of its own pre-mRNA. The U1A autoregulatory
complex requires two molecules of U1A protein to cooperatively bind a 50
nucleotide polyadenylation-inhibitory element (PIE) RNA located in the U1A 3'
untranslated region. Based on both biochemical and nuclear magnetic resonance
structural data, it was predicted that protein-protein interactions between the N
terminal regions (amino acids [aa] 1 to 115) of the two U1A proteins would form
the basis for cooperative binding to PIE RNA and for inhibition of
polyadenylation. In this study, we not only experimentally confirmed these
predictions but discovered some unexpected features of how the U1A autoregulatory
complex functions. We found that the U1A protein homodimerizes in the yeast two
hybrid system even when its ability to bind RNA is incapacitated. U1A
dimerization requires two separate regions, both located in the N-terminal 115
residues. Using both coselection and gel mobility shift assays, U1A dimerization
was also observed in vitro and found to depend on the same two regions that were
found in vivo. Mutation of the second homodimerization region (aa 103 to 115)
also resulted in loss of inhibition of polyadenylation and loss of cooperative
binding of two U1A protein molecules to PIE RNA. This same mutation had no effect
on the binding of one U1A protein molecule to PIE RNA. A peptide containing two
copies of aa 103 to 115 is a potent inhibitor of polyadenylation. Based on these
data, a model of the U1A autoregulatory complex is presented.
PMID- 10688668
TI - Two independent signaling pathways mediate the antiapoptotic action of macrophage
stimulating protein on epithelial cells.
AB - In addition to its effects on macrophage function, macrophage-stimulating protein
(MSP) is a growth and motility factor for epithelial cells. The growth and
survival of epithelial cells generally require two signals, one generated by
interaction with extracellular matrix via integrins, the other initiated by a
growth factor. Therefore we investigated the effect of MSP on epithelial cell
survival. Survival of epithelial cells cultured overnight in serum-free medium
was promoted by adhesion, which activated both the phosphatidylinositol 3'-kinase
(PI3-K)/AKT and mitogen-activated protein kinase (MAPK) pathways, operating
independently of one another. The number of apoptotic cells resulting from
inhibition of either pathway alone was approximately doubled by simultaneous
inhibition of both pathways. This shows that each pathway made a partial
contribution to the prevention of apoptosis. In the presence of an inhibitor of
either pathway, MSP increased the activity of the other pathway so that the
single uninhibited pathway alone was sufficient to prevent apoptosis. In contrast
to the results with adherent cells, although MSP also prevented apoptosis of
cells in suspension (anoikis), its effect was mediated only by the PI3-K/AKT
pathway. Despite activation of MAPK by MSP, anoikis was not prevented in
suspended cells with a blocked PI3-K/AKT pathway. Thus, activation of MAPK alone
is not sufficient to mediate MSP antiapoptotic effects. Cell adhesion generates
an additional signal, which is essential for MSP to use MAPK in an antiapoptotic
pathway. This may involve translocation of MSP-activated MAPK from the cytoplasm
into the nucleus, which occurs only in adherent cells. Our results suggest that
there is cross talk between cell matrix adhesion and growth factors in the
regulation of cell survival via the MAPK pathway. Growth factors induce MAPK
activation, and adhesion mediates MAPK translocation from the cytoplasm into the
nucleus.
PMID- 10688669
TI - Interaction of dishevelled and Xenopus axin-related protein is required for wnt
signal transduction.
AB - Signaling by the Wnt family of secreted proteins plays an important role in
animal development and is often misregulated in carcinogenesis. Wnt signal
transduction is controlled by the rate of degradation of beta-catenin by a
complex of proteins including glycogen synthase kinase 3 (GSK3), adenomatous
polyposis coli, and Axin. Dishevelled is required for Wnt signal transduction,
and its activation results in stabilization of beta-catenin. However, the
biochemical events underlying this process remain largely unclear. Here we show
that Xenopus Dishevelled (Xdsh) interacts with a Xenopus Axin-related protein
(XARP). This interaction depends on the presence of the Dishevelled-Axin (DIX)
domains in both XARP and Xdsh. Moreover, the same domains are essential for
signal transduction through Xdsh. Finally, our data point to a possible mechanism
for signal transduction, in which Xdsh prevents beta-catenin degradation by
displacing GSK3 from its complex with XARP.
PMID- 10688670
TI - Stimulus-specific assembly of enhancer complexes on the tumor necrosis factor
alpha gene promoter.
AB - The human tumor necrosis factor alpha (TNF-alpha) gene is rapidly activated in
response to multiple signals of stress and inflammation. We have identified
transcription factors present in the TNF-alpha enhancer complex in vivo following
ionophore stimulation (ATF-2/Jun and NFAT) and virus infection (ATF-2/Jun, NFAT,
and Sp1), demonstrating a novel role for NFAT and Sp1 in virus induction of gene
expression. We show that virus infection results in calcium flux and calcineurin
dependent NFAT dephosphorylation; however, relatively lower levels of NFAT are
present in the nucleus following virus infection as compared to ionophore
stimulation. Strikingly, Sp1 functionally synergizes with NFAT and ATF-2/c-jun in
the activation of TNF-alpha gene transcription and selectively associates with
the TNF-alpha promoter upon virus infection but not upon ionophore stimulation in
vivo. We conclude that the specificity of TNF-alpha transcriptional activation is
achieved through the assembly of stimulus-specific enhancer complexes and through
synergistic interactions among the distinct activators within these enhancer
complexes.
PMID- 10688672
TI - Compensation by fibroblast growth factor 1 (FGF1) does not account for the mild
phenotypic defects observed in FGF2 null mice.
AB - Fibroblast growth factor 1 (FGF1) and FGF2, the prototypic members of the FGF
family of growth factors, have been implicated in a variety of physiological and
pathological processes. Unlike most other FGFs, FGF1 and FGF2 are ubiquitously
expressed and are not efficiently secreted. Gene knockouts in mice have
previously demonstrated a role for FGF2 in brain development, blood pressure
regulation, and wound healing. The relatively mild phenotypic defects associated
with FGF2 deletion led to the hypothesis that the continued expression of other
FGFs partially compensated for the absence of FGF2 in these mice. We now report
our generation of mice lacking FGF1 and their use, in combination with our
previously described FGF2 null mice, to produce mice lacking both FGF1 and FGF2.
FGF1-FGF2 double-knockout mice are viable and fertile and do not display any
gross phenotypic defects. In the double-knockout mice we observed defects that
were similar in extent to those previously described for the FGF2 null mice.
Differences in the organization of neurons of the frontal motor cortex and in the
rates of wound healing were observed. We also observed in FGF2(-/-) mice and in
FGF1-FGF2 double-knockout mice novel impairments in hematopoiesis that were
similar in severity. Essentially no abnormalities were found in mice lacking only
FGF1. Our results suggest that the relatively mild defects in FGF2 knockout
animals are not a consequence of compensation by FGF1 and suggest highly
restricted roles for both factors under normal developmental and physiological
conditions.
PMID- 10688673
TI - Cytoplasmic sequestration of rel proteins by IkappaBalpha requires CRM1-dependent
nuclear export.
AB - Rel and IkappaB protein families form a complex cellular regulatory network. A
major regulatory function of IkappaB proteins is to retain Rel proteins in the
cell cytoplasm. In addition, IkappaB proteins have also been postulated to serve
nuclear functions. These include the maintenance of inducible NF-kappaB-dependent
gene transcription, as well as termination of inducible transcription. We show
that IkappaBalpha shuttles between the nucleus and the cytoplasm, utilizing the
nuclear export receptor CRM1. A CRM1-binding export sequence was identified in
the N-terminal domain of IkappaBalpha but not in that of IkappaBbeta or
IkappaBepsilon. By reconstituting major aspects of NF-kappaB-IkappaB
sequestration in yeast, we demonstrate that cytoplasmic retention of p65 (also
called RelA) by IkappaBalpha requires Crm1p-dependent nuclear export. In
mammalian cells, inhibition of CRM1 by leptomycin B resulted in nuclear
localization of cotransfected p65 and IkappaBalpha in COS cells and enhanced
nuclear relocation of endogenous p65 in T cells. These observations suggest that
the main function of IkappaBalpha is that of a nuclear export chaperone rather
than a cytoplasmic tether. We propose that the nucleus is the major site of p65
IkappaBalpha association, from where these complexes must be exported in order to
create the cytoplasmic pool.
PMID- 10688671
TI - mSin3A regulates murine erythroleukemia cell differentiation through association
with the TAL1 (or SCL) transcription factor.
AB - Activation of the TAL1 (or SCL) gene is the most frequent gain-of-function
mutation in T-cell acute lymphoblastic leukemia (T-ALL). TAL1 belongs to the
basic helix-loop-helix (HLH) family of transcription factors that bind as
heterodimers with the E2A and HEB/HTF4 gene products to a nucleotide sequence
motif termed the E-box. Reported to act both as an activator and as a repressor
of transcription, the mechanisms underlying TAL1-regulated gene expression are
poorly understood. We report here that the corepressor mSin3A is associated with
TAL1 in murine erythroleukemia (MEL) and human T-ALL cells. Interaction mapping
showed that the basic-HLH domain of TAL1 was both necessary and sufficient for
TAL1-mSin3A interaction. TAL1 was found, in addition, to interact with the
histone deacetylase HDAC1 in vitro and in vivo, and a specific histone
deacetylase inhibitor, trichostatin A (TSA), relieved TAL1-mediated repression of
an E-box-containing promoter and a GAL4 reporter linked to a thymidine kinase
minimal promoter. Further, TAL1 association with mSin3A and HDAC1 declined during
dimethyl sulfoxide-induced differentiation of MEL cells in parallel with a
decrease in mSin3A abundance. Finally, TSA had a synergistic effect with enforced
TAL1 expression in stimulating MEL cells to differentiate, while constitutive
expression of mSin3A inhibited MEL cell differentiation. These results
demonstrate that a corepressor complex containing mSin3A and HDAC1 interacts with
TAL1 and restricts its function in erythroid differentiation. This also has
implications for this transcription factor's actions in leukemogenesis.
PMID- 10688674
TI - Structure and function analysis of LIN-14, a temporal regulator of postembryonic
developmental events in Caenorhabditis elegans.
AB - During postembryonic development of Caenorhabditis elegans, the heterochronic
gene lin-14 controls the timing of developmental events in diverse cell types.
Three alternative lin-14 transcripts are predicted to encode isoforms of a novel
nuclear protein that differ in their amino-terminal domains. In this paper, we
report that the alternative amino-terminal domains of LIN-14 are dispensable and
that a carboxy-terminal region within exons 9 to 13 is necessary and sufficient
for in vivo LIN-14 function. A transgene capable of expressing only one of the
three alternative lin-14 gene products rescues a lin-14 null mutation and is
developmentally regulated by lin-4. This shows that the deployment of alternative
lin-14 gene products is not critical for the ability of LIN-14 to regulate
downstream genes in diverse cell types or for the in vivo regulation of LIN-14
level by lin-4. The carboxy-terminal region of LIN-14 contains an unusual
expanded nuclear localization domain which is essential for LIN-14 function.
These results support the view that LIN-14 controls developmental timing in C.
elegans by regulating gene expression in the nucleus.
PMID- 10688688
TI - Occurrence of Bacillus thuringiensis in fresh waters of Japan.
AB - Bacillus thuringiensis was recovered at a relatively high frequency from both
running and still fresh waters in natural environments of Kyushu, Japan. Of 107
water samples examined, 53 (49.5%) contained this organism. The frequency of B.
thuringiensis colonies was 4.4% among 4414 colonies of the Bacillus cereus/B.
thuringiensis group. The density of this bacterium in fresh waters averaged 0.45
cfu/ml. Serologically, B. thuringiensis isolates were assigned to 26 H serotypes.
Of these, H14/36 (H serovar israelensis/malaysiensis) was the predominant,
followed by the serotypes H3abc (kurstaki), H27 (mexicanensis), H3ad
(sumiyoshiensis), and H35 (seoulensis). Of 195 isolates, 52 (26.7%) exhibited
larvicidal activity against aquatic Diptera; 21 killed Culex pipiens molestus
(Culicidae) only, and 31 were active on both the culicine mosquito and the moth
fly, Clogmia albipunctata (Psychodidae). The Diptera-toxic isolates produced
spherical or irregularly pointed parasporal inclusions.
PMID- 10688689
TI - Effects of salt and pH stress on temperature-tolerant Rhizobium sp. NBRI330
nodulating Prosopis juliflora.
AB - A study was conducted to examine the growth response of a rhizobial strain
Rhizobium sp. NBRI330 isolated from root nodules of Prosopis juliflora growing in
alkaline soil. The strain had the ability to nodulate P. juliflora. Nursery grown
plants inoculated with Rhizobium sp. NBRI330 had 60.6% higher plant dry weight,
as compared with uninoculated plants. The individual stress survival limit of a
rhizobial strain Rhizobium sp. NBRI330 isolated from alkaline soil in a medium
containing 32% (wt/vol) salt was 8 h, and at 55 degrees C up to 3 h. The length
of Rhizobium sp. NBRI330 in salt-stressed cells increased significantly to 3.04
microm from 1.75 microm of non-stressed control cells. On the contrary, the
length of pH-stressed cells declined to 1.40 microm. Compared with non-stressed
control rod-shaped cells, the shape of temperature-stressed cells changed to
spherical, of 0.42 microm diameter. High temperature (45 degrees C) was tolerated
efficiently by Rhizobium sp. NBRI330 in the presence of salt at pH 12, as
compared with pH 7.
PMID- 10688690
TI - Cloning of two new cry genes from Bacillus thuringiensis subsp. wuhanensis
strain.
AB - With PCR products as probes, we have cloned two new cry-type genes from Bacillus
thuringiensis subsp. wuhanensis. The deduced amino acid sequence of the first
clone is 77.3% identical to Cry1Ga1. The deduced protein sequence of the second
clone is 69.8-78.7% identical to that of Cry1B group. The nomenclature assignment
of these two clones is, therefore, named Cry1Gb1 and Cry1Bd1, respectively. The
Cry1Bd1 is toxic to Plutella xylostella larvae, and the Cry1Gb1 is toxic to
Pieris rapae larvae.
PMID- 10688691
TI - Identification of a lexA gene in, and construction of a lexA mutant of,
Xanthomonas campestris pv. citri.
AB - The lexA gene of Xanthomonas campestris pathovar citri (X.c. pv. citri) was
cloned and sequenced. The 639-bp open reading frame encodes a protein of 213
amino acids that shares substantial sequence homology with the products of
previously characterized lexA genes, sharing 46% identity with the LexA protein
of Escherichia coli. Amino acids required for autocatalytic cleavage of LexA are
conserved in the X.c. pv. citri protein, whereas domains thought to mediate DNA
binding differ markedly from those of LexA proteins from E. coli and other
bacteria. The X.c. pv. citri LexA protein was overexpressed in E. coli, and SDS
polyacrylamide gel electrophoresis revealed a molecular size of 23 kDa for the
purified protein. A lexA mutant of X.c. pv. citri was constructed by gene
replacement, and the basal level of recA expression in this mutant was shown to
be similar to that for wild-type cells exposed to a DNA-damaging agent. These
results indicate that LexA functions as a repressor of recA expression in X.c.
pv. citri.
PMID- 10688692
TI - Purification and characterization of an extracellular alkaline serine protease
from Aspergillus terreus (IJIRA 6.2).
AB - An extracellular alkaline serine protease has been purified from Aspergillus
terreus (IJIRA 6.2). The purification procedure involved chromatography on DEAE
Sephadex A25, phosphocellulose, hydroxyapatite, casein-Sepharose, gel filtration
on Sephacryl-S-300 and by glycerol density gradient centrifugation. The enzyme
was further purified to apparent homogeneity through a combination of
electrophoresis in polyacrylamide gel containing 0.1% sodium dodecyl sulfate
(SDS) with or without protease substrate (gelatin) and subsequent regeneration of
its activity in situ by removal of SDS. The active enzyme was visualized in a
zymogram or on the basis of protease activity exhibited on an X-ray film. The
protein in the unstained segment of the gel was electroeluted. The eluted protein
with protease activity exhibited a molecular mass of 37,000-daltons on
electrophoresis in SDS-polyacrylamide gel. A sedimentation coefficient of 3.2S
was obtained by glycerol density gradient contrifugation. Maximum activity of
protease was observed at pH 8.5 and at 37 degrees C. Purified protease was active
between pH 5.5 and 9.5 and was found to be stable up to 60 degrees C. With Na
caseinate, the K(m) of the purified protease was found to be 0.055 mM. Antipain,
phenylmethane sulfonyl fluoride, and chymostatin served as non-competitive
inhibitors. Substrate specificity was determined by using a synthetic chromogenic
peptide containing N-P-Tosyl-Gly-Pro-Arg-p-nitroanilide. Results showed that the
protease cleaved the peptide on the -COOH end of arginine residue.
PMID- 10688693
TI - Genetic organization and polymorphism of the guaA gene encoding the GMP
synthetase in Lactobacillus rhamnosus.
AB - The guaA gene encoding GMP synthetase was cloned from a potential probiotic
strain of Lactobacillus rhamnosus. DNA sequence and Northern blot analysis
indicated that (i) guaA did not belong to an guaAB operonic structure, conversely
to enteric bacteria, (ii) L. rhamnosus guaA seemed to be highly expressed, and
(iii) genetic regulation might differ from Bacillus subtilis. Moreover,
differences in the genetic organization of guaA allowed discrimination of some
closely related L. rhamnosus strains, with a rapid screening by PCR.
PMID- 10688694
TI - Secondary structural and phylogenetic implications of nuclear large subunit
ribosomal RNA in the ectomycorrhizal fungus Tricholoma matsutake.
AB - The sequence of large subunit (LSU) and 5.8S rRNA genes has been determined for
Tricholoma matsutake. A secondary structure model was predicted for both LSU and
5.8S rRNAs, showing most of the structural features consistent with those of the
consensus secondary structure model proposed for the eukaryotic cytoplasmic LSU
rRNAs. With a reconstructed eukaryotic phylogeny based on full-length LSU rDNA
sequences, T. matsutake was placed on the same branch with Cryptococcus
neoformans as its closest neighbor. We proposed that T. matsutake be considered
as one of the representative members of the division Basidiomycota. Here we
report for the first time the complete LSU rRNA gene sequence in T. matsutake, a
member of Homobasidiomycetes.
PMID- 10688695
TI - Expression of Clostridium thermocellum endoglucanase gene in Lactobacillus
gasseri and Lactobacillus johnsonii and characterization of the genetically
modified probiotic lactobacilli.
AB - Endoglucanase A from Clostridium thermocellum resistant to pancreatic proteinase
was selected out of a range of microbial cellulases expressed in lactobacilli.
Two Lactobacillus-E. coli expression vectors, harboring the endoglucanase gene
from C. thermocellum under the control of its own promoter (pSD1) and the
Lactococcus lactis lac A promoter (pSD2), were constructed separately. Intestinal
Lactobacillus strains, L. gasseri and L. johnsonii, were electrotransformed with
pSD1 and pSD2, and the stability of each plasmid was evaluated. The endoglucanase
activities of 0.722 and 0.759 U/ml were respectively found in culture medium of
L. gasseri and L. johnsonii containing pSD1, and of 0.407 U/ml in medium of L.
gasseri harboring pSD2. When the probiotic characteristics such as acid
tolerance, bile-salt tolerance, and antibiotic susceptibility were investigated,
L. gasseri and L. johnsonii were resistant to low pHs of 2 and 3. Also, L.
johnsonii was bile-salt resistant in the presence of 0.5% oxgall and porcine bile
extract. L. johnsonii and L. gasseri showed a rather homogeneous resistant
pattern against tested antibiotics. Both strains were resistant to amikacin,
bacitracin, gentamicin, streptomycin, kanamycin, and colistin.
PMID- 10688696
TI - Molecular characterization of the leucine plasmid from Buchnera aphidicola,
primary endosymbiont of the aphid Acyrthosiphon pisum.
AB - The complete sequence of the leucine plasmid of Buchnera aphidicola from the
aphid Acyrthosiphon pisum (pLeu-BAp) is reported. Its gene organization was
concordant with those of other leucine plasmids of Buchnera from aphids of the
Aphidini and Macrosiphini tribes. Three inverted repeats are present in pLeu-BAp.
Two of them are also present in pLeu from the family Aphididae: (i) SIR1, located
downstream the leucine operon, resembles a rho-independent terminator of
transcription, and (ii) LIR1, located upstream of the leucine operon, is
suggested to be involved in transcription termination or messenger stability. The
third, located near the putative ATGC repeats involved in the origin of
replication, is specific in aphids of the Macrosiphini tribe. Phylogenetic
analyses based on sequences of leuA, leuB, leuC, leuD, repA1 and ORF1 showed a
closer relationship between Buchnera (A. pisum) and Buchnera (Diuraphis noxia).
However, tree topologies indicate that the split between both aphid species took
place soon after the formation of the Macrosiphini lineage.
PMID- 10688697
TI - Uniparental mitochondrial transmission in sexual crosses in Cryptococcus
neoformans.
AB - Restriction fragment length polymorphism (RFLP) in the large ribosomal RNA region
of the mitochondrial DNA (mtDNA) was developed as a genetic marker for
investigating mitochondrial transmission in sexual crosses of the human
pathogenic basidiomycetous yeast Cryptococcus neoformans. Strain JEC20 of C.
neoformans var. neoformans (mat a) was mated with six strains of C. neoformans
var. grubii (mat alpha). Successful mating was indicated by the formation of
hyphae and basidiospores. These basidiospores were examined for mtDNA RFLP
genotypes. All 570 basidiospores examined from the six crosses showed the mtDNA
genotype of strain JEC20. The failure to recover the C. neoformans var. grubii
mtDNA in any cross indicates that the C. neoformans var. grubii mtDNA is either
selectively eliminated in the newly formed dikaryon or selectively excluded in
the immediate dikaryotic hyphae of the newly formed dikaryon.
PMID- 10688698
TI - Characterization of the extracellular polysaccharide produced by a marine
cyanobacterium, Cyanothece sp. ATCC 51142, and its exploitation toward metal
removal from solutions.
AB - Cyanobacterium, Cyanothece sp. ATCC 51142 produces an exopolysaccharide at a high
level. Physical analysis of the exopolysaccharide (EPS), such as nuclear magnetic
resonance, infrared spectrum, were done to determine its possible structure.
Thermal gravimetric analysis, differential scanning calorimeter, and differential
thermal analysis of the polymer were done to find out the thermal behavior.
Calcium content within the sample was found out. Some of the physicochemical
properties, such as relative viscosity, specific viscosity, and intrinsic
viscosity of the EPS were studied under different conditions. The phenomenon of
gel formation by the EPS was investigated for its potential application in metal
removal from solutions.
PMID- 10688699
TI - Strains of Xylella fastidiosa rapidly distinguished by arbitrarily primed-PCR.
AB - Genomic DNAs isolated from strains of Xylella fastidiosa that caused citrus
variegated chlorosis, coffee leaf scorch, Pierce's Disease of grapevine, and plum
leaf scorch were analyzed by arbitrarily primed polymerase chain reaction.
Purified DNA was amplified under nonstringent conditions with single primers 21
nucleotides (nt) long. Thirty-nine amplification products were observed that were
useful to distinguish among the strains and to derive a similarity matrix and
construct a phenogram showing possible relationships among the strains. Strains
isolated from diseased coffee and citrus in Brazil were closely related to each
other (coefficient of similarity of 0. 872), but only distantly related to a
strain isolated from diseased grapevine in the USA (coefficient of similarity of
0.650). Strains of Xylella fastidiosa isolated from diseased plums in the USA and
Brazil clustered with strains from different hosts isolated from their respective
countries of origin. Thus, there may be two quite dissimilar clusters of strains
of Xylella fastidiosa, one in North America and the other in South America. Each
cluster contains strains that can cause disease in plum. The methods described
provide a convenient and rapid method to distinguish between strains of Xylella
fastidiosa that cause diseases of coffee and citrus in the same region of Brazil.
This has not been possible previously. This will potentially enable the two
strains to be distinguished in alternate hosts or in insect vectors.
PMID- 10688700
TI - HSP16.6 is involved in the development of thermotolerance and thylakoid stability
in the unicellular cyanobacterium, Synechocystis sp. PCC 6803.
AB - The low molecular weight (LMW) heat shock protein (HSP), HSP16.6, in the
unicellular cyanobacterium, Synechocystis sp. PCC 6803, protects cells from
elevated temperatures. A 95% reduction in the survival of mutant cells with an
inactivated hsp16.6 was observed after exposure for 1 h at 47 degrees C. Wild
type cell survival was reduced to only 41%. HSP16.6 is also involved in the
development of thermotolerance. After a sublethal heat shock at 43 degrees C for
1 h and subsequent challenge exposure at 49 degrees C for 40 min, mutant cells
did not survive, while 64% of wild-type cells survived. Ultrastructural changes
in the integrity of thylakoid membranes of heat-shocked mutant cells also are
discussed. These results demonstrate an important protective role for HSP16.6 in
the protection of cells and, in particular, thylakoid membrane against thermal
stress.
PMID- 10688702
TI - Routes of Ethephon Uptake in Pineapple (Ananas comosus) and Reasons for Failure
of Flower Induction.
AB - Ethylene-releasing agents such as ethephon (2-chloroethylphosphonic acid) are
used widely to induce flowering in pineapples (Ananas comosus (L.) Merrill).
However, ethephon treatment is less reliable in summer, particularly if plants
are treated on abnormally hot days. [(14)C]ethephon was used to follow uptake and
translocation in leaf tissues. Up to 30% of the ethephon entered the leaf within
4 h, and up to 60% by 24 h. Uptake was dramatically modified by temperature,
relative humidity, solution pH, and the surface on which solution droplets were
placed. Entry occurred across the leaf cuticle and probably also by way of
stomatal pores, and label was recovered at all depths within the leaf. (14)C
label entered more rapidly through the abaxial epidermis than through the adaxial
epidermis. Low-volume spray applications to whole plants resulted in rapidly
drying droplets mainly on the adaxial, distal epidermis and were rather
ineffective at inducing flowering, possibly because little ethephon or ethylene
reaches the shoot apex. High-volume sprays may facilitate ethephon entry because
solution accumulates in leaf axils and hence remains in prolonged contact with
abaxial epidermis of leaf bases close to the shoot apex. When poured into the
center of the plant, 20% of a normal commercial ethephon dose induced full
flowering even under adverse temperatures. It is suggested that high-volume
evening spraying and avoidance of hot days may reduce the incidence of flowering
failure.
PMID- 10688703
TI - Opening of Rice Floret in Rapid Response to Methyl Jasmonate.
AB - Effects of methyl jasmonate (MeJA) on rice floret opening were investigated in
seven cultivars or hybrid combinations covering various variety types. Intact or
excised panicles, judged to have florets just before anthesis, were soaked in 4 x
10(-5) - 4 x 10(-3)M MeJA solutions for 2 min at different temperatures. The
results indicated that MeJA significantly induced opening of rice florets within
about 30 min, with the most rapid induction occurring just 6 min after treatment.
Numbers of induced opening florets are correlated with MeJA concentrations.
Higher concentrations of MeJA induced more florets. pH values had no influence on
MeJA effect, but MeJA required less time and induced more florets at 34 degrees C
than at 25 degrees C. As far as we know, this is the first evidence that floret
opening is induced by plant hormones. CO(2) evolution from panicles was also
increased by MeJA treatment. Field experiments revealed that perfect flowering
synchrony between the cytoplasmic male sterile (CMS) and restorer lines in hybrid
seed production could be obtained by spraying MeJA solution on CMS line plants at
the rate of 25 mg/m(2). As a result, many more hybrid seeds were harvested.
PMID- 10688704
TI - Putrescine Influences Growth and Production of Coumarins in Hairy Root Cultures
of Witloof Chicory (Cichorium intybus L. cv. Lucknow Local).
AB - The effect of putrescine (Put) on the growth and production of two coumarins,
esculin and esculetin, in hairy roots of chicory (Cichorium intybus L. cv.
Lucknow local) was examined. To study the role of Put on growth and production of
coumarins, polyamine inhibitors, namely alpha-dl-difluromethylornithine and alpha
dl-difluromethylarginine were used at 1 mM concentration. Put treatment at 1.5 mM
produced a 1.9-fold increase in the growth of hairy roots, as well as the
production of esculin and esculetin. The treatments with polyamine (PA)
inhibitors resulted in much lower growth and production of coumarins compared
with both 1.5-mM Put treatment and the control. Both free and conjugated PAs were
studied over the whole culture period, and conjugates of all three PAs, namely
Put, spermidine, and spermine, were higher than free PAs throughout the culture
period. The treatments with PA inhibitors showed lower levels of endogenous PAs
compared with Put-treated samples. The treatment with 1.5 mM Put showed maximum
accumulation of endogenous conjugated Put (2,098 +/- 157 nmoles gm(-1) fresh
weight). The production of esculin and esculetin was strictly correlated with
growth in all treatments. Put at 1.5 mM resulted in greater length of primary
root (18.3 +/- 1.4 cm) as compared with the control (11 +/- 0.9 cm) and larger
numbers of secondary and tertiary roots.
PMID- 10688705
TI - Gibberellins and Subapical Cell Divisions in Relation to Bud Set and Bud Break in
Salix pentandra.
AB - In young plants of Salix pentandra, a temperate zone deciduous woody species,
elongation growth ceases and a terminal bud is formed at day lengths shorter than
a critical length. This is the first step in dormancy development, making
survival under harsh winter conditions possible. Early studies strongly indicate
that gibberellin is involved in the photoperiodic control of bud set and bud
break. GA(1) action was studied by application under short days to plants where
cessation of shoot elongation had occurred, followed by subsequent anatomic
investigations of shoot tips. Under short days the frequency of cell division
decreased rapidly along with the earlier observed decrease in GA(1) levels.
Application of GA(1) to short-day-induced terminal buds rapidly stimulated cell
division in apices several days before visible shoot elongation in response to
this treatment was observed. One day after GA(1) application a fourfold increase
in cell division frequency in apices was observed, increasing to a maximum of
sevenfold 2 days after application. Long-day treatment leading to induction of
bud break after about 4-6 days was followed by slowly increasing frequency of
cell divisions. In earlier studies of this species, short days and gibberellins
had no effect on cell elongation. These data show that increased GA(1) content,
by application or long-day treatment, results in increased frequency of mitosis.
This strongly indicates that GA(1) affects stem elongation in connection with bud
set and bud break primarily by affecting cell divisions in subapical tissues.
PMID- 10688706
TI - Herbicidal Derivatives of Aminomethylenebisphosphonic Acid. Part IV.
Hydroxyalkylidenebisphosphonates, Iminomethylenebisphosphonates and
Ureidomethylenebisphosphonates.
AB - Derivatives of aminomethylenebisphosphonic acids constitute a class of promising
herbicides. Replacement of the amino group by hydroxyl, ureido, thioureido, or
imino moieties leads to compounds of significant herbicidal properties. This
indicates that protonated amino function is not a requirement for phytotoxic
action of bisphosphonates.
PMID- 10688707
TI - New Plant Growth Regulators Protect Photosynthesis and Enhance Growth Under
Drought of Jack Pine Seedlings.
AB - To determine whether natural plant growth regulators (PGRs) can enhance drought
tolerance and the competitive ability of transplanted seedlings, 1.5-year-old
jack pine (Pinus banksana Lamb.) seedlings were treated with homobrassinolide,
salicylic acid, and two polyamines, spermine and spermidine, triacontanol,
abscisic acid (ABA), and the synthetic antioxidant, Ambiol. PGRs were fed into
the xylem for 7 days and plants were droughted by withholding water for 12 days.
ABA, Ambiol, spermidine, and spermine at a concentration of 10 ug L(-1)
stimulated elongation growth under drought, whereas ABA, Ambiol, and spermidine
maintained higher photosynthetic rates, higher water use efficiency, and lower
Ci/Ca ratio under drought compared with control plants. The damaging effects of
drought on membrane leakage was reversed by Ambiol, ABA, triacontanol,
spermidine, and spermine. Because ABA, Ambiol, and both polyamines enhanced
elongation growth and also reduced membrane damage in jack pine under drought,
they show promise as treatments to harden seedlings against environmental stress.
The protective action of these compounds on membrane integrity was associated
with an inhibition of ethylene evolution, with a reduction in transpiration rate
and an enhancement of photosynthesis, which together increased water use
efficiency under drought. Although most of the tested compounds acted as
antitranspirants, the inhibition in membrane leakage in ABA-, Ambiol-, and
polyamine-treated plants appeared more closely related to the antiethylene
action.
PMID- 10688708
TI - Influence of 2,3,5-Triiodobenzoic Acid and 1-N-Naphthylphthalamic Acid on
Indoleacetic Acid Transport in Carnation Cuttings: Relationship with Rooting.
AB - (3)H-IAA transport in excised sections of carnation cuttings was studied by using
two receiver systems for recovery of transported radioactivity: agar blocks (A)
and wells containing a buffer solution (B). When receivers were periodically
renewed, transport continued for up to 8 h and ceased before 24 h. If receivers
were not renewed, IAA transport decreased drastically due to immobilization in
the base of the sections. TIBA was as effective as NPA in inhibiting the
basipetal transport irrespective of the application site (the basal or the apical
side of sections). The polarity of IAA transport was determined by measuring the
polar ratio (basipetal/acropetal) and the inhibition caused by TIBA or NPA. The
polar ratio varied with receiver, whereas the inhibition by TIBA or NPA was
similar. Distribution of immobilized radioactivity along the sections after a
transport period of 24 h showed that the application of TIBA to the apical side
or NPA to the basal side of sections, increased the radioactivity in zones
further from the application site, which agrees with a basipetal and acropetal
movement of TIBA and NPA, respectively. The existence of a slow acropetal
movement of the inhibitor was confirmed by using (3)H-NPA. From the results
obtained, a methodological approach is proposed to measure the variations in
polar auxin transport. This method was used to investigate whether the variations
in rooting observed during the cold storage of cuttings might be related to
changes in polar auxin transport. As the storage period increased, a decrease in
intensity and polarity of auxin transport occurred, which was accompanied by a
delay in the formation and growth of adventitious roots, confirming the
involvement of polar auxin transport in supplying the auxin for rooting.
PMID- 10688709
TI - Photodynamic therapy in dermatology.
AB - The combination of light and chemicals to treat skin diseases is widely practiced
in dermatology. Within this broad use of light and drugs, in recent years the
concept of photodynamic therapy (PDT) has emerged. PDT is a promising modality
for the management of various tumors and nonmalignant diseases, based on the
combination of a photosensitizer that is selectively localized in the target
tissue and illumination of the lesion with visible light, resulting in
photodamage and subsequent cell death. Moreover, the fluorescence of
photosensitizing compounds is also utilized as a helpful diagnostic tool for the
detection of neoplastic tissue. Intensive basic and clinical research culminated
in the worldwide approval of PDT for bladder, esophageal, and lung cancer. The
expanding use of this relatively new therapeutic modality in dermatology at many
centers around the world has revealed its efficacy for the treatment of cutaneous
precancer and cancer, as well as selected benign skin disorders. The following
article summarizes the main principles of PDT considering the most recent
developments and provides a comprehensive synopsis of the present status of the
use of PDT in dermatology. (J Am Acad Dermatol 2000;42:389-413.) LEARNING
OBJECTIVE: At the conclusion of this learning activity, participants should be
able to describe the basic concepts of PDT, including fundamental knowledge of
the most relevant photosensitizers, the light sources, the mechanisms involved in
PDT-mediated cell destruction, as well as the indications and limitations of
photodynamic treatment of skin diseases.
PMID- 10688710
TI - Patch granuloma annulare: clinicopathologic study of 6 patients.
AB - BACKGROUND: Granuloma annulare is a common skin disorder that usually presents
with smooth papules arranged as annular plaques. Variants, such as disseminated,
subcutaneous, and perforating granuloma annulare, have been described. OBJECTIVE:
The purpose of this study is to describe the clinical and histologic features of
a distinct patch form of granuloma annulare. METHODS: The clinical and histologic
features of 6 patients with patch granuloma annulare were evaluated. RESULTS: Six
women 27 to 72 years of age had patches on the extremities. Two patients also had
a lesion on the trunk. Only one patient had annular patches. Histologic
examination showed an interstitial infiltrate of lymphocytes and histiocytes with
diffuse necrobiosis. CONCLUSION: Patch granuloma annulare is a distinct variant
with rather subtle clinical and histologic features. A high index of suspicion
both clinically and histologically aids in making the diagnosis.
PMID- 10688711
TI - Patterns of remission in pemphigus vulgaris.
AB - BACKGROUND: The incidence of remissions in pemphigus is unclear because these are
usually reported at a single point in the evolution of the disease. Thus it is
uncertain whether treatment simply suppresses the manifestations of the disease
and consequently must be continuously administered, or induces complete and long
lasting remissions that permit therapy to be discontinued. OBJECTIVE: To answer
this question, we investigated the incidence of remission in a long-term
longitudinal study. METHODS: The induction of complete and long-lasting
remissions (lesion free with no systemic therapy for at least 6 months) was
studied in 40 patients with pemphigus vulgaris treated conventionally and
followed up for an average of 7.7 years by the same investigator. RESULTS: Five
(5%) of the patients died of the disease. Complete and long-lasting remissions
were induced in 25%, 50%, and 75% of patients 2, 5, and 10 years, respectively,
after diagnosis. Most of the remaining patients were in partial remission or had
mild disease controlled with a small dose of steroids. The course of the disease
followed different patterns, with some patients rapidly entering complete and
long-lasting remissions, whereas others never entered into a complete remission.
The induction of complete remission was related to the initial severity and
extent of disease and to early response to treatment. CONCLUSION: It is possible
to eventually induce complete and durable remissions in most patients with
pemphigus that permit systemic therapy to be safely discontinued without a flare
in disease activity. The proportion of patients in whom this can be achieved
increases steadily with time, and therapy can be discontinued in approximately
75% of patients after 10 years.
PMID- 10688712
TI - Effects of administration of a single dose of a humanized monoclonal antibody to
CD11a on the immunobiology and clinical activity of psoriasis.
AB - BACKGROUND: CD11a/CD18 comprise subunits of leukocyte function associated antigen
(LFA-1), a T-cell surface molecule important in T-cell activation, T-cell
emigration into skin, and cytotoxic T-cell function. OBJECTIVE: We explored the
immunobiologic and clinical effects of treating moderate to severe psoriasis
vulgaris with a single dose of humanized monoclonal antibody against CD11a
(hu1124). METHODS: This was an open label study with a single dose of hu1124 at
doses of 0.03 to 10 mg/kg. Clinical (Psoriasis Area and Severity Index [PASI])
and immunohistologic parameters (epidermal thickness, epidermal and dermal T-cell
numbers, and keratinocyte intercellular adhesion molecule 1 [ICAM-1] expression)
were followed. RESULTS: Treatment with hu1124, at doses higher than 1.0 mg/kg
(group III), completely blocks CD11a staining for at least 14 days in both blood
and psoriatic plaques. At 0.3 to 1.0 mg/kg, T-cell CD11a staining was completely
blocked; however, blockade lasted less than 2 weeks (group II). Only partial
saturation of either blood or plaque cellular CD11a was observed at doses of
hu1124 between 0.01 and 0.1 mg/kg (group I). This pharmacodynamic response was
accompanied by decreased numbers of epidermal and dermal CD3(+) T cells,
decreased keratinocyte and blood vessel expression of ICAM-1, and epidermal
thinning. Statistically significant drops in PASI compared with baseline were
observed in group II patients at weeks 3 and 4 and in group III patients at weeks
2 through 10. No significant drop in PASI score was observed in group 1. Adverse
events were mild at doses of 0.3 mg/kg or less and included mild chills,
abdominal discomfort, headache, and fever. At a single dose of 0.6 mg/kg or
higher, headache was the most common dose-limiting toxicity observed. CONCLUSION:
Targeting CD11a may improve psoriasis by inhibiting T-cell activation, T-cell
emigration into the skin, and cytotoxic T-cell function.
PMID- 10688713
TI - Rate of body dysmorphic disorder in dermatology patients.
AB - BACKGROUND: Dermatologists appear to be the physicians most often seen by
patients with the psychiatric condition body dysmorphic disorder (BDD), a
distressing or impairing preoccupation with a nonexistent or slight defect in
appearance. The frequency of BDD among patients seeking dermatologic treatment is
unknown, however. OBJECTIVE: This study determined the percentage of patients
seeking dermatologic treatment who screened positive for BDD. METHODS: A
validated self-report questionnaire and a reliable defect severity scale were
used to determine the rate of BDD in 268 patients seeking dermatologic treatment.
RESULTS: A total of 11.9% (95% confidence interval [CI], 8.0%-15.8%) of patients
screened positive for BDD. Rates were similar in a community general dermatology
setting (14.4% [95% CI, 8.5%-20.3%]) and a university cosmetic surgery setting
(10. 0% [95% CI, 6.1%-13.9%]). CONCLUSION: BDD appears relatively common among
patients seeking dermatologic treatment. Further research is needed to confirm
these findings and to assist dermatologists in identifying these potentially high
risk patients.
PMID- 10688714
TI - Davener's dermatosis: a variant of friction hypermelanosis.
AB - BACKGROUND: As part of our clinical experience we encountered a group of patients
from a specific population with a similar peculiar pigmentation over the lower
dorsal spine. OBJECTIVE: We investigated these patients to see whether we could
determine a common origin. METHODS: Patients meeting the inclusion criteria
underwent detailed history and complete physical examination; biopsy specimens
from 3 patients were studied. RESULTS: All 13 patients were full-time male
students at Orthodox Jewish Talmudic seminaries (Yeshivas). The lesion consisted
of an elongated, vertical, midline, hyperpigmented patch with indistinct borders,
which was distributed along the skin overlying the bony protuberances of the
inferior thoracic and lumbar vertebrae. It was often unrecognized by the
patients. Mean body mass index was lower than that for the general population.
Histologic study showed a marked diffuse hyperkeratosis and hyperplastic
epidermis with diffuse hyperpigmentation. We attributed the phenomenon to
friction from the rigid backrests against the cutaneous surface of the lower back
generated by the characteristic swaying activity that traditionally accompanies
Torah study or "davening" (praying) and termed it Davener's dermatosis.
CONCLUSION: We believe this phenomenon represents a new form of benign friction
hypermelanosis. This report highlights the importance of a thorough history in
patients presenting with pigmented lesions.
PMID- 10688715
TI - Host-related and environmental risk factors for cutaneous basal cell carcinoma:
evidence from an Italian case-control study.
AB - BACKGROUND: Despite its frequency, there is a paucity of data on risk factors for
basal cell carcinoma. OBJECTIVE: We assessed potential risk factors for basal
cell carcinoma in a population from southern Europe. METHODS: This multicenter
case-control study involved 528 newly diagnosed cases and 512 controls. RESULTS:
In the multivariate analysis, red hair, lighter colored eyes, high nevus counts
on the upper limbs, and the presence of solar lentigines and actinic keratoses
were all associated with basal cell carcinoma. The risk of the tumor increased in
subjects who reported burning easily and experiencing sunburn episodes before 15
years of age. An association was documented with indices of recreational sun
exposure but no clear evidence of exposure-effect relationship was found. No
relation was found with occupational sun exposure. Finally, basal cell carcinoma
appeared to be significantly associated with a family history of skin tumors, a
personal history of tumors other than those on skin, and radiotherapy.
CONCLUSION: Genetic and environmental factors appear to be involved in the onset
of basal cell carcinoma.
PMID- 10688716
TI - The radiation accident in Georgia: clinical appearance and diagnosis of cutaneous
radiation syndrome.
AB - BACKGROUND: Eleven male Georgian soldiers were accidentally exposed to radiation
by cesium 137 during their training in a military exercise camp in Lilo, Georgia
between November 1996 and May 1997. OBJECTIVE: The characteristic sequelae of
accidental cutaneous irradiation and available diagnostic methods are described.
METHODS: Magnetic resonance imaging (MRI) of radiation ulcers was performed in
all patients; thermography was performed in 2. In 7 patients ulcers and white
macules were examined with high-frequency 20 MHz sonography; histologic results
were obtained from all patients. RESULTS: Predominant lesions were radiation
ulcers in 11 patients and white hairless macules in 7. MRI showed ulcers down to
the muscles and an increase of signal intensity in the musculature in 9 cases.
The corresponding muscle histology demonstrated vasculitis in 7 patients and
necrosis in 2. In 2 patients, MRI signal intensity of the musculature was normal.
In 3 patients, 20 MHz sonography showed dermal defects; 1 patient had cutaneous
fibrosis. Thermography demonstrated hypothermic zones with extended inflammatory
zones adjacent to the radiation ulcers in both patients examined. CONCLUSION:
High-frequency 20 MHz sonography, MRI, and thermography are useful noninvasive
methods for diagnosis of the extent of cutaneous radiation syndrome and for
therapy planning.
PMID- 10688717
TI - The combination of 2% 4-hydroxyanisole (Mequinol) and 0.01% tretinoin is
effective in improving the appearance of solar lentigines and related
hyperpigmented lesions in two double-blind multicenter clinical studies.
AB - BACKGROUND: Solar lentigines are a chronic condition of the aging population
resulting from years of cumulative sun exposure. A topical treatment that is both
safe and effective would be welcome and useful. Combinations of therapeutic
agents are often used and allow synergy of mechanisms with tolerability. A
tyrosinase inhibitor in use in Europe, 4-hydroxyanisole (Mequinol), and the
retinoid tretinoin have been used singly as depigmenting agents. OBJECTIVE: The
efficacy and safety of the combination product of 2% 4-hydroxyanisole (4HA
[mequinol]) /0.01% tretinoin solution (tradename Solage) were evaluated in two
phase III, randomized, controlled, double-blind trials. METHODS: Subjects were
randomized to treatment with 4HA/tretinoin solution, one of the active components
(4HA or tretinoin), or vehicle. Subjects applied the test solution with a wand
applicator twice daily to all solar lentigines and related hyperpigmented lesions
on the face, forearms, and backs of hands for up to 24 weeks. Trial 1 had a 24
week no-treatment regression phase and trial 2 had a 4-week no-treatment
regression phase. Information collected included clinical assessments of Target
Lesion Pigmentation, Physician's Global Assessment of Improvement/Worsening, an
Assessment of Overall Cosmetic Effect, and a Subject's Self-Assessment
Questionnaire. RESULTS: The 4HA/tretinoin combination was clinically superior to
each of its active components and to the vehicle in the treatment of solar
lentigines. At the end of treatment, in trial 1 and trial 2, 4HA/tretinoin was
statistically superior to each of its active components and vehicle on the
forearms and face (P =.03), except versus tretinoin on the face in trial 2 (P
=.2). In trial 2, a trend toward greater efficacy of 4HA/tretinoin over tretinoin
on the face was demonstrated at the end of treatment (P =.2), which was also
increasingly evident at the end of the 4-week follow-up (P =.06). Most skin
related adverse events were mild and were similar for both the 4HA/tretinoin and
tretinoin treatment groups. CONCLUSION: For the treatment of solar lentigines and
related hyperpigmented lesions, the topical combination product containing 2%
4HA/0.01% tretinoin solution is well tolerated and superior to either active
component.
PMID- 10688718
TI - The clinicopathologic spectrum of rhinophyma.
AB - We report the results of a clinicopathologic study of 17 patients with rhinophyma
in different stages of evolution, with particular attention paid to the severe
form of this disease. On the basis of clinical features, we identified 2 groups
of patients: the first group (12/17 patients) included patients with the common
form of rhinophyma, whereas the second one (5/17 patients) included patients with
the severe form of the disease. There was no link between the clinical aspect and
the duration of the disease. Microscopic examination of specimens obtained from
the classic type of rhinophyma substantially showed the histopathologic features
of fully developed rosacea, except for the presence of prominent sebaceous
hyperplasia. The second group showed a very different histologic pattern
displaying marked dermal thickness, absence of folliculosebaceous structures,
sclerotic collagen bundles with large amounts of mucin, and spreading
telangiectasia. The inflammatory infiltrate was inconspicuous, with numerous
interstitial spindle and bizarre cells. Most of the interstitial cells were
reactive to factor XIIIa. The severe form of rhinophyma shares many histologic
characteristics with elephantiasis caused by chronic lymphedema.
PMID- 10688719
TI - Expression of the cyclin-dependent kinase inhibitor p27 in keratoacanthoma.
AB - BACKGROUND: Keratoacanthomas are characterized by initial rapid enlargement
followed by clinical regression. A series of cyclin and cyclin-dependent kinase
complexes regulate cell cycle progression. p27(kip) inhibits a variety of cyclin
cyclin-dependent kinase complexes in vitro and may act to hold eukaryotic cells
in a quiescent state (G0). OBJECTIVE: We examined expanding and regressing
keratoacanthomas for expression of p27(kip). METHODS: An immunohistochemical
method was used to visualize and count p27(kip)-labeled cells in 5 expanding and
15 regressing keratoacanthomas. RESULTS: In normal epidermis p27(kip) was found
overlying the nuclei of suprabasilar keratinocytes. In expanding keratoacanthoma
there was little expression of p27(kip) in nuclei of atypical keratinocytes
composing the tumor (1.25 +/- 2.1 labeled cells per high-power field); in
regressing keratoacanthoma the nuclei of most suprabasilar keratinocytes in
atypical tumor aggregates contained p27(kip) (55.1 +/- 28.6 labeled cells per
high-power field). The difference was significant at P values of less than.001.
CONCLUSION: The identification of p27(kip) in regressing keratoacanthoma but not
in expanding keratoacanthoma suggests that p27(kip) may be playing a role in
promoting regression of keratoacanthoma and is a potential target for
pharmacologic intervention.
PMID- 10688720
TI - PUVA-related punctate keratoses of the hands and feet.
AB - BACKGROUND: We have observed, in patients undergoing high-dose PUVA treatment, a
type of keratosis not previously described. The lesions usually occur on the
sides of the palms or soles and are clinically distinct. They are generally
painless and often go unnoticed by patients. OBJECTIVE: We sought to further
characterize these lesions both clinically and histologically. METHODS: Patients
attending a PUVA clinic were screened for these keratoses. Other PUVA-related
complications were recorded. Representative lesions were photographed, and biopsy
specimens were taken. RESULTS: Biopsy specimens were taken from lesions in 10
patients. All had plaque psoriasis and had received high UVA doses (>1000
J/cm(2)) through PUVA therapy. All patients had PUVA-induced keratoses elsewhere,
but the number varied greatly between patients. The hand and foot keratoses were
well defined and circular and had a characteristic histologic appearance, with a
sharp demarcation between normal and abnormal markedly pale-staining epidermis.
CONCLUSION: These lesions are a further cutaneous manifestation of prolonged PUVA
therapy.
PMID- 10688721
TI - Newer strategies for effective evaluation of primary melanoma and treatment of
stage III and IV disease.
AB - Our objective in this article is to update dermatologists on the clinical
management of malignant melanoma, including the role of sentinel node biopsy and
options for the treatment of stage III and stage IV disease. The role of the
dermatologist throughout the continuum of care is emphasized, and the essential
partnership with medical oncology in recognizing promising new options for
patients with advanced disease is examined.
PMID- 10688722
TI - Potassium iodide and the wolff-chaikoff effect: relevance for the dermatologist.
AB - The inhibition of organic binding of iodide in the thyroid gland by excess
iodide, resulting in the cessation of thyroid hormone synthesis, is known as the
Wolff-Chaikoff effect. This review explores the nature of the Wolff-Chaikoff
effect, both in terms of its potential mechanisms and its relevance to
dermatologists who use potassium iodide as a therapeutic agent.
PMID- 10688723
TI - Combination phototherapy of psoriasis with narrow-band UVB irradiation and
topical tazarotene gel.
AB - BACKGROUND: Narrow-band UVB (311 nm) phototherapy offering an emission spectrum
closely conforming to the peak of the action spectrum for clearing psoriasis has
significantly improved phototherapy for psoriasis. Because the majority of the
commonly used topical therapies in treatment of psoriasis have limitations, a
need for new topical agents remains. Tazarotene has been shown to be efficacious
in plaque-type psoriasis. Combination of narrow-band UVB with topical agents has
been shown to enhance efficacy of both treatment modalities. OBJECTIVE: We
attempted to evaluate the efficacy of narrow-band UVB phototherapy in combination
with topical tazarotene. METHODS: Ten patients with stable plaque psoriasis were
treated with narrow-band UVB. In addition, topical tazarotene 0.05% was applied
once daily to one side of the body. The follow-up period was 4 weeks. Efficacy
was assessed separately for both body halves by means of a modified Psoriasis
Area and Severity Index (PASI). RESULTS: Both treatment modalities notably
reduced the PASI scores with values being significantly lower in skin areas
treated with narrow-band UVB phototherapy in combination with topical tazarotene.
CONCLUSION: The addition of tazarotene to narrow-band UVB phototherapy promotes
more effective, faster clearing of psoriasis compared with UVB (311 nm)
monotherapy.
PMID- 10688724
TI - A comparative immunohistochemical study of MART-1 expression in Spitz nevi,
ordinary melanocytic nevi, and malignant melanomas.
AB - BACKGROUND: The histopathologic differential diagnosis of Spitz nevus (SN) from
malignant melanoma (MM) may be difficult. OBJECTIVE: We attempted to elucidate
the pattern of expression of a newly recognized melanocyte-specific melanosomal
protein MART-1 in routinely processed specimens of SNs, MMs, and ordinary
melanocytic nevi (MNs) and to see whether it can help to differentiate between
them. METHODS: Twenty SN, 22 MM, and 27 ordinary MN were immunostained with anti
MART-1 monoclonal antibody (clone A103). RESULTS: All SNs, MNs, and MMs
demonstrated cytoplasmic staining for MART-1 in some of their tumor cells, of
which 17 of 20 (85%) and 24 of 27 (89%) of SN and MN, respectively, demonstrated
positive stainings in more than half of their tumor cells, as compared with only
10 of 22 (45%) of the MM (P <.05). The majority of lesions in all 3 types of
tumors showed a homogeneous mode of staining, although MM tended to show a more
heterogeneous pattern. A consistent pattern of stratification of staining with
progressive descent into the dermis was not demonstrated in these tumors.
CONCLUSION: MART-1 does not differentiate between SN, MM, and ordinary MN in a
consistent pattern, but it may be used as a marker for these tumors.
PMID- 10688725
TI - Skin disorders in amputees.
AB - BACKGROUND: Dermatologic problems restrict the normal use of a prosthetic limb.
The importance of contact dermatitis to skin morbidity in a population of
amputees and the selection criteria for patch testing have not been clearly
defined. OBJECTIVE: We describe the range of dermatoses seen in a population of
amputees and examine the incidence, causes, and patterns of contact dermatitis.
METHODS: This is a questionnaire-based, cross-sectional study of 210 amputees.
Those with a skin problem were assessed by a dermatologist. Patch testing was
undertaken in patients with persistent dermatitis. RESULTS: A total of 34% of
amputees experienced a skin problem. Lesions resulting from friction, pressure,
and occlusion are common. Allergic contact dermatitis is seen in a third of
patients with stump dermatitis. There are no features that distinguish allergic
from irritant (chemical or physical) dermatitis. CONCLUSION: Dermatologic
problems are common in prosthetic limb users. Allergic contact dermatitis is a
significant problem, and all patients with dermatitis on the residual limb should
be patch tested.
PMID- 10688726
TI - Surgical pearl: prompt treatment of subungual hematoma by decompression.
PMID- 10688728
TI - Madelung's disease involving the tongue.
AB - Madelung's disease or benign symmetric lipomatosis is rare. Symmetric lipomatosis
of the tongue as an association of Madelung's disease is very rare; up to now
only two cases of this association have been reported. We report the third case
of Madelung's disease with involvement of the tongue in the form of macroglossia.
PMID- 10688729
TI - Pemphigus foliaceus successfully treated with mycophenolate mofetil as a steroid
sparing agent.
AB - Pemphigus foliaceus is an autoimmune blistering disease of unknown origin with
antibodies produced against desmoglein 1, an adhesive protein found in the
desmosomal cell junction in the suprabasal layers of the epidermis. The disease
is primarily treated with corticosteroids and corticosteroid-sparing
immunosuppressive agents. We report a case of pemphigus foliaceus successfully
treated with mycophenolate mofetil. It remains to be seen whether this agent has
a significant effect on the course of the disease and remission induction.
PMID- 10688730
TI - Linear verrucous hemangioma.
AB - A 16-year-old male patient had multiple angiokeratotic lesions arranged in a
linear pattern on his left arm. Histopathologic examination showed characteristic
features of verrucous hemangioma. This entity should be distinguished from
angiokeratoma or simple hemangioma. The linear arrangement of lesions as observed
in this case may reflect genetic mosaicism. Deep surgery is the best treatment
for verrucous hemangioma.
PMID- 10688731
TI - Scleroderma-like reaction induced by uracil-tegafur (UFT), a second-generation
anticancer agent.
AB - UFT, a combination of uracil and tegafur, is a second-generation anticancer
agent. UFT has been used in Japan, other Asian countries, South America, and
Russia. Recently, UFT has been extensively studied for colorectal, pancreatic,
and various types of cancer in North America and Europe, especially with
leukovorin. We report a case of a scleroderma-like reaction induced by long-term
administration of UFT. This is the first report of UFT-induced scleroderma-like
reaction.
PMID- 10688732
TI - A case of ichthyosis linearis circumflexa successfully treated with topical
tacrolimus.
AB - We report a case of ichthyosis linearis circumflexa (ILC) without the typical
atopic manifestations and deformities of the hair shaft. The patient responded
positively to treatment with topical tacrolimus, suggesting that abnormalities in
the immunoregulatory mechanism may be involved in the pathogenesis of ILC.
PMID- 10688733
TI - Squamous cell carcinoma, not basal cell carcinoma, is the most common cancer in
humans.
PMID- 10688734
TI - Sentinel lymph node biopsy as an adjunct to management of histologically
difficult to diagnose melanocytic lesions: a proposal.
AB - There is a significant subset of primary cutaneous melanocytic neoplasms that are
difficult to diagnose with the use of routine light microscopy. The currently
recommended approach in assessing such lesions is to make a histopathologic
diagnosis that reflects some uncertainty and then to recommend complete surgical
excision. While adequate in many cases, the excision that might be recommended
for such a lesion if malignant would be mutilating in many others. To increase
the sensitivity of diagnosis and to provide potentially useful prognostic
information, we propose that sentinel lymphadenectomy be considered in patients
with melanocytic neoplasms of uncertain behavior that are 1.0 mm or more in
thickness.
PMID- 10688735
TI - Liver biopsies and methotrexate: a time for reconsideration?
PMID- 10688736
TI - Does Helicobacter pylori eradication treatment reduce the severity of rosacea?
PMID- 10688738
TI - Helicobacter pylori: related to rosacea?
PMID- 10688740
TI - Does Helicobacter pylori have a role in the pathogenesis of rosacea?
PMID- 10688744
TI - Role of the development scientist in compound lead selection and optimization.
AB - The R&D process for bringing drugs from discovery laboratories to the marketplace
is undergoing rapid change, as enabled by new technologies and as demanded by the
global pharmaceutical business environment. One consequence of the accelerated
R&D paradigm is a blurring of the traditional discovery-development interface,
which in turn impacts the traditional roles of discovery and development
scientists. R&D organizations must find ways to screen out rapidly compounds that
have relatively poor probability of successful registration. Quality of
development candidates can be favorably influenced by early consideration of
"developability" criteria along with receptor-based potency and specificity.
Computational approaches and/or high-throughput experimental determinations will
be used increasingly to profile compound characteristics which influence
"developability." If such criteria are considered at the time of lead selection
and optimization, the compound attrition rate during later development should be
decreased from the historical norm. This article discusses the emerging role of
development scientists during small-molecule lead selection and optimization. The
changing role of development scientists also has implications for graduate
curricula in the pharmaceutical sciences.
PMID- 10688745
TI - Inter-study variability in population pharmacokinetic meta-analysis: when and how
to estimate it?
AB - Population pharmacokinetic analysis is being increasingly applied to individual
data collected in different studies and pooled in a single database. However,
individual pharmacokinetic parameters may change randomly from one study to
another. In this article, we show by simulation that neglecting inter-study
variability (ISV) does not introduce any bias for the fixed parameters or for the
residual variability but may result in an overestimation of inter-individual
(IIV) variability, depending on the magnitude of the ISV. Two random study-effect
(RSE) estimation methods were investigated: (i) estimation, in a single step, of
the three-nested random effects (inter-study, inter-individual and residual
variability); (ii) estimation of residual variability and a mixture of ISV and
IIV in the first step, then separation of ISV from IIV in the second. The one
stage RSE model performed well for population parameter assessment, whereas, the
two-stage model yielded good estimates of IIV only with a rich sampling design.
Finally, irrespective of the method used, ISV estimates were valid only when a
large number of studies was pooled. The analysis of one real data set illustrated
the use of an ISV model. It showed that the fixed parameter estimates were not
modified, whether an RSE model was used or not, probably because of the
homogeneity of the experimental designs of the studies, and suggest no study
effect in this example.
PMID- 10688746
TI - Systemic availability and lymphatic transport of human growth hormone
administered by subcutaneous injection.
AB - Degradation of human growth hormone (hGH) at the injection site has previously
been implicated as the basis for its reduced systemic availability following
subcutaneous (SC) administration. The goal of these studies was to develop an
animal model which would allow mass balance calculations to (i) quantify the loss
at the injection site and (ii) determine the role of the lymphatics in the
transport of subcutaneously-administered hGH. The animal model utilized a sheep
and enabled simultaneous sampling of blood and collection of either peripheral
lymph (via the efferent duct of the popliteal lymph node draining the injection
site) or central lymph (via the thoracic lymph duct). In non-lymph cannulated
sheep, the systemic availability of hGH following SC dosing was 58.4 +/- 9.1%
(mean +/- SEM) relative to an intravenous (IV) control. The availability of hGH
decreased to approximately 30-40% when either peripheral or central lymph was
collected indicating that a proportion of the dose was transported via the lymph.
The fraction of the administered dose collected in peripheral lymph was 61.7 +/-
8.5% (mean +/- SEM), whereas only 8.6 +/- 1.3% was collected in central lymph.
These results suggested that loss of hGH within the lymphatics contributed
significantly to its reduced systemic availability following SC administration.
The total recovery (sum of the systemic availability and the cumulative amount
recovered in lymph) of hGH was approximately 93% of the dose in the peripherally
cannulated group indicating that loss at the injection site was minimal.
PMID- 10688747
TI - Characterization of wet masses of pharmaceutical powders by triaxial compression
test.
AB - The mechanical and rheologic properties of wet masses of pharmaceutical powders
determine their processibility and the quality of the product prepared by
extrusion/spheronization. In this work, a triaxial compression test was attempted
for the first time to characterize material properties of pharmaceutical wet
masses of different hydrophilicity and particle sizes. The stress-strain curves
and the pore pressure were determined at various cell pressures. The failure
criteria of the wet masses were obtained from the stress path on the deviator
stress plane. The cohesion (c) and the angle of internal friction (phi) were
evaluated from the intercept and the slope of the failure loci. The stress-strain
behavior strongly depended on the type of powders and cell pressure. The values
of c and phi were similar for wet masses of EC FP, MCC PH101, and SMCC 50, but a
very small phi and a very high c value for HPMC. The shear strength and rigidity
of the wet masses were in the order of EC FP > SMCC 50 > MCC PH101 > HPMC,
whereas the elastic recovery was in the opposite order. These material parameters
could be used as references for selection of excipients and formulation for
extrusion/spheronization.
PMID- 10688748
TI - Isolation and identification of metabolites of porfiromycin formed in the
presence of a rat liver preparation.
AB - The isolation and identification of the major metabolites of porfiromycin formed
in the presence of a rat liver preparation under aerobic conditions were
performed with high-performance liquid chromatography and electrospray ionization
mass spectrometry. Porfiromycin was extensively metabolized by the rat liver
preparation in an aqueous 0.1 M potassium phosphate buffer (pH 7.4) containing an
NADPH generating system at 37 degrees C. A total of eight metabolites was
identified as mitosene analogs. Of these, three primary metabolites are 2
methylamino-7-aminomitosene, 1,2-cis and 1,2-trans-1-hydroxy-2-methylamino-7
aminomitosene, which are consistent with those previously observed in hypoxia
using purified rat liver NADPH-cytochrome c reductase. Interestingly, 2
methylamino-7-aminomitosene is a reactive metabolite, which undergoes further
activation at the C-10 position by the loss of carbamic acid and then links with
the 7-amino group of the primary metabolites to yield two dimeric adducts. In
addition, three phosphate adducts, 10-decarbamoyl-2-methylamino-7-aminomitosene
10-phosphate, 1,2-cis and 1,2-trans-2-methylamino-7-aminomitosene-1-phosphate,
were also identified in the incubation system. The configurations of the
diastereoisomeric metabolites were determined with (1)HNMR and phosphatase
digestion. On the basis of the metabolite profile, we propose in vitro metabolic
pathways for porfiromycin. The findings provide direct evidence for understanding
the reactive nature and hepatic metabolism of the drug currently in phase III
clinical trials.
PMID- 10688749
TI - Optimization of storage stability of lyophilized actin using combinations of
disaccharides and dextran.
AB - The storage stability of a dry protein depends on the structure of the dried
protein, as well as on the storage temperature relative to the glass transition
temperature of the dried preparation. Disaccharides are known to preserve the
native conformation of a dried protein; however, the resulting T(g) of the sample
may be too low ensure adequate storage stability. On the other hand, formulations
dried with high molecular weight carbohydrates, such as dextran, have higher
glass transition temperatures, but fail to preserve native protein conformation.
We tested the hypothesis that optimizing both protein structure and T(g) by
freeze-drying actin with mixtures of disaccharides and dextran would result in
increased storage stability compared to actin dried with either disaccharide or
dextran alone. Protein structure in the dried solid was analyzed immediately
after lyophilization and after storage at elevated temperatures with infrared
spectroscopy, and after rehydration by infrared and circular dichroism
spectroscopy. Structural results were related to the polymerization activity
recovered after rehydration. Degradation was noted with storage for formulations
containing either sucrose, trehalose, or dextran alone. Slight increases in T(g)
observed in trehalose formulations compared to sucrose formulations did not
result in appreciable increases in storage stability. Addition of dextran to
sucrose or trehalose increased formulation T(g) without affecting the capacity of
the sugar to inhibit protein unfolding during lyophilization and resulted in
improved storage stability. Also, dextran provides an excellent amorphous bulking
agent, which can be lyophilized rapidly with formation of strong, elegant cake
structure. These results suggest that the strategy of using a mixture of
disaccharide and polymeric carbohydrates can optimize protein storage stability.
PMID- 10688750
TI - Studies on the structure of the complex of the boron neutron capture therapy
drug, L-p-boronophenylalanine, with fructose and related carbohydrates: chemical
and 13C NMR evidence for the beta-D-fructofuranose 2,3,6-(p
phenylalanylorthoboronate) structure.
AB - The complex of L-L-boronophenylalanine (L-p-BPA) with fructose has been used for
the past 5 years in clinical trials of boron neutron capture therapy to treat
both melanoma and glioblastoma multiforme. However, the structure of this complex
in water buffered at physiologic pH has not been established. In the (1)H NMR
spectra (D(2)O buffered at pD 7.4) of the complex of L-p-BPA with various
carbohydrates, the upfield chemical shifts of the aromatic protons of L-p-BPA
confirm that the boron atom is negatively charged and tetrahedral. In the (13)C
NMR spectrum of the complex of L-p-BPA with U-(13)C labeled fructose, the
chemical shifts and (1)J(CC) coupling constants are consistent with fructose
adopting the beta-D-fructofuranose form. In addition, the (1)J(CC) coupling
constants along with the binding constants measured for L-p-BPA with a series of
monosaccharides and disaccharides seem to suggest that the beta-D-fructofuranose
2,3,6-(p-phenylalanylorthoboronate) structure strongly predominates, with free L
p-BPA and fructose the only other species detected.
PMID- 10688751
TI - Use of alveolar cell monolayers of varying electrical resistance to measure
pulmonary peptide transport.
AB - The apparent permeability coefficient (P(app)) of two fluorescently tagged model
hydrophilic peptides, acXASNH(2) and acXAS(GAS)(7)NH(2), and (14)C-mannitol
across monolayers of cultured rat alveolar epithelial cells of varying
transepithelial electrical resistance (TER) has been examined. In line with their
design features, the peptides were not degraded under the conditions of the test.
Furthermore, no concentration dependence of transport of the tripeptide
acXASNH(2) was observed over the concentration range studied, nor was any
directional transport seen for either of the model peptides, indicating that
under the conditions of the test they were not substrates for any transporters or
efflux pumps. From the hydrophilic nature of the peptides (as assessed by their
log P), and their inverse dependence of transport with molecular weight and TER,
it was assumed that the peptides were transported across the cell monolayer
passively via the paracellular route. The observed P(app) for the transport of
(14)C-mannitol and the peptides across rat alveolar epithelial cell monolayers
were found to be inversely (though not linearly) related to the measured TER and
could be well-modeled assuming the presence of two populations of "pores" in the
cell monolayer, namely, cylindrical pores of diameter 1.5 nm and large pores of
diameter 20 nm. The relative populations of the two types of pores varied with
the TER of the monolayer, with the number of large pores decreasing with an
increase in TER (and the number of small pores taken as fixed). These results
suggest that if the cell monolayer is well characterized with respect to the
passage of a range of probe molecules across monolayers of varying electrical
resistance, it should be possible to predict the P(app) of any hydrophilic
peptide or drug crossing the membrane by the paracellular route at any desired
TER using a monolayer of any electrical resistance, above a minimum value.
PMID- 10688752
TI - Physico-chemical characterization of a novel tricyclic beta-lactam antibiotic.
AB - GV118819X, a novel tricyclic beta-lactam antibiotic of GlaxoWellcome, is a
racemic mixture of two diastereoisomers, A and B. Of the two diastereoisomers,
only A is available as a pure compound. By analyzing mixtures of GV118819X and A,
a partial phase diagram is constructed, which indicates the presence of a
eutectic when the A fraction is approximately 39%. Moreover, the melting
enthalpies of the eutectic mixture and of diastereoisomer B can be estimated.
With the exception of the pure A form, all mixtures undergo important
modifications in morphology and microstructure as a consequence of thermal
treatments, which induce melting/amorphization of the eutectic, and
crystallization of the A form. Analyses of the sieved fractions of GV118819X
demonstrate that it consists of acicular crystals of different composition, with
the larger crystals having a larger A fraction than the smaller ones. Grinding
causes melting/amorphization of the eutectic and, following hours-long
treatments, the formation of a substantial fraction of submicron particles with
unusually low melting temperatures.
PMID- 10688753
TI - Cyclodextrin-catalyzed deacetylation of spironolactone is pH and cyclodextrin
dependent.
AB - The complexation of spironolactone (SP) with cyclodextrins (CDs) and the effect
of pH on the CD catalyzed deacetylation of SP was studied in the presence of beta
cyclodextrin (beta-CD), hydroxypropyl-beta-cyclodextrin (HP-beta-CD),
sulfobutylether-beta-cyclodextrin ([SBE](7m)-beta-CD), gamma-cyclodextrin (gamma
CD), and sulfobutylether gamma-cyclodextrin (SBE-gamma-CD). The complexation of
SP with beta-CD and the mechanism of deacetylation was confirmed using NMR. The
complexation of SP with CDs was determined by means of the phase-solubility
method at pH 2, in which chemical degradation was minimal. The phase-solubility
diagrams were classified as A(L)-type and the apparent stability constants
(K(1:1)) for 1 : 1 inclusion complex were calculated to be 9939 M(-1), 10,976 M(
1), 15,816 M(-1), 4792 M(-1) and 4118 M(-1) for beta-CD, HP-beta-CD, (SBE)(7m)
beta-CD, gamma-CD, and SBE-gamma-CD, respectively. The effect of pH on the
degradation rate of SP was studied in the presence and absence of 4.4 mM CD
solutions at pH 4, 5, 6, 7, and 8 (25 degrees C). The stability studies showed
that CD-catalyzed degradation of SP can be decreased by lowering the pH. The pH
rate profiles of SP degradation with different CDs gave slopes of 1.0. Because no
buffer catalysis was observed, the reaction appears to be specific-base
catalyzed. The catalytic activity of CDs was as follows: SBE-gamma-CD < (SBE)(7m)
beta-CD < HP-beta-CD approximately gamma-CD < beta-CD. NMR studies confirmed that
SP forms an inclusion complex with beta-CD and complexation occurs by means of
the secondary face. The NMR studies also showed that during the deacetylation of
SP, the secondary hydroxyl groups of beta-CD at the 2- and 3-position were
acetylated. The decrease of catalytic activity of CDs at low pH values and the
CDs differing ability to catalyze the degradation of SP correlated qualitatively
with the ionization state of the CD hydroxyl groups, which were lower in SBE-CDs.
The site of binding differences and the number of hydroxyl groups present
probably also contribute to the differences.
PMID- 10688754
TI - Spherical crystal agglomeration of ibuprofen by the solvent-change technique in
presence of methacrylic polymers.
AB - The effects of Eudragit(R) nature on the formation and spherical agglomeration of
ibuprofen microcrystals have been examined when solvent change (ethanol-water)
technique is applied. Four methacrylic polymers (Eudragit(R) S100, L100, RS, and
RL), with different solubility and solubilizing ability, were used. The
extrapolated points of maximum temperature deviation rate in crystallization
liquid that reflect the maximum crystallization rate and the corresponding water
addition were determined, as well as crystal yielding and incorporation of drug
and polymer in the agglomerates. The physicomechanical properties of the
agglomerates, such as size, sphericity, surface roughness and porosity, as well
as flow and packing or compression behavior during tableting, were evaluated for
different drug/polymer ratios. It was found that crystal yield is greatly reduced
in the presence of water-insoluble polymers and that formation of the
microcrystals and incorporation of drug and polymer are affected by the polymer
nature. Crystal formation changes are attributed to alterations in the metastable
zone, whereas the changes in drug and polymer incorporation and crystal yield are
caused by changes in the polymers' solubility and micellization. The size of
agglomerates depends on the polymer nature and its interactions with the
ibuprofen microcrystals formed. Sphericity, surface roughness, and intraparticle
porosity of agglomerates increase, in general, with the presence of polymer owing
to changes in habit and growth rate of the microcrystals and to their coating
before binding into spherical agglomerates. The particle density or intraparticle
porosity and size changes determine flow or packing behavior and densification of
agglomerates at low compression. The incorporation and brittleness of the polymer
determine the deformation under higher compression pressure, expressed as yield
pressure, Py.
PMID- 10688755
TI - Kinetic study of a 2-hydroxypropyl-beta-cyclodextrin-based formulation of all
trans-retinoic acid in Sprague-Dawley rats after oral or intravenous
administration.
AB - all-trans-Retinoic acid (ATRA, vitamin A acid, or tretinoin) is a potent
chemotherapeutic agent for the treatment of acute promyelocytic leukemia (APL).
Its poor aqueous solubility not only affects its oral absorption but also
prevents it from forming an aqueous parenteral formulation. Recently, we
developed a water-soluble formulation of ATRA with 2-hydroxypropyl-beta
cyclodextrin (HPbetaCD). In present study, this formulation was tested in Sprague
Dawley rats. Kinetic study of ATRA was carried out after oral or intravenous
administration. Though there were no statistical differences in any of the
estimated pharmacokinetic parameters between ATRA sodium salt and HPbetaCD-based
ATRA after intravenous administration, inclusion of ATRA into HPbetaCD was found
to greatly improve the oral absorption of ATRA.
PMID- 10688756
TI - Dissolution of ionizable water-insoluble drugs: the combined effect of pH and
surfactant.
AB - This study reports the results of the combined effect of pH and surfactant on the
dissolution of piroxicam (PX), an ionizable water-insoluble drug in physiological
pH. The intrinsic dissolution rate (J(total)) of PX was measured in the pH range
from 4.0 to 7.8 with 0%, 0.5%, and 2.0% sodium lauryl sulfate (SLS) using the
rotating disk apparatus. Solubility (c(total)) was also measured in the same pH
and SLS concentration ranges. A simple additive model including an ionization (PX
<--> H(+) + PX(-)) and two micellar solubilization equilibria (PX + micelle <-->
[PX](micelle), PX(-) + micelle <--> [PX(-)](micelle)) were considered in the
convective diffusion reaction model. J(total) and c(total) of PX increased with
increasing pH and SLS concentration in an approximately additive manner.
Nonlinear regression analysis showed that observed experimental data were well
described with the proposed model (r(2) = 0.86, P < 0.001 for J(total) and r(2) =
0.98, P < 0.001 for c(total)). The pK(a) value of 5.63 +/- 0.02 estimated from
c(total) agreed well with the reported value. The micellar solubilization
equilibrium coefficient for the unionized drug was estimated to be 348 +/- 77
L/mol, while the value for the ionized drug was nearly equal to zero. The
diffusion coefficients of the species PX, PX(-), and [PX](micelle) were estimated
from the experimental results as (0. 93 +/- 0.35) x 10(-5), (1.4 +/- 0.30) x 10(
5), and (0.59 +/- 0.21) x 10(-5) cm(2)/s, respectively. The total flux
enhancement is less than the total solubility enhancement due to the smaller
diffusion coefficients of the micellar species. This model may be useful in
predicting the dissolution of an ionizable water insoluble drug as a function of
pH and surfactant and for establishing in vitro-in vivo correlations, IVIVC, for
maintaining bioequivalence of drug products.
PMID- 10688757
TI - Comparative effects of (SBE)7m-beta-CD and HP-beta-CD on the stability of two
anti-neoplastic agents, melphalan and carmustine.
AB - The purpose of this study was to evaluate and compare the potential use of two
parenterally safe beta-cyclodextrins derivatives, (SBE)7m-beta-CD and HP-beta-CD,
as solubilizers and stabilizers for melphalan and carmustine, two very unstable
antineoplastic agents. Phase solubility and chemical stability of the compounds
in the presence of the cyclodextrins were studied. UV, fluorescence, and several
NMR techniques were used to probe the potential causes for the differences
observed. The phase solubility method was found to provide only qualitative data
on the binding of melphalan to the cyclodextrins since rapid degradation and the
presence of products of degradation complicated the interpretation of the
results. Qualitatively, however, the solubilizing potential was similar for the
two cyclodextrins. The chemical stability studies indicate that both of the drugs
had similar binding constants for both cyclodextrins; however, the intrinsic
reactivities in the complexes were significantly lower with (SBE)7m-beta-CD than
for HP-beta-CD. The main cause for this distinct difference appeared to correlate
with differences in the site of binding and the polarity of the binding site.
PMID- 10688758
TI - Editorial
PMID- 10688759
TI - Halo Profiles and the Nonlinear Two- and Three-Point Correlation Functions of
Cosmological Mass Density.
AB - We investigate the nonlinear two- and three-point correlation functions of the
cosmological density field in Fourier space and test the popular hierarchical
clustering model that assumes a scale-independent three-point amplitude Q. In
high-resolution N-body simulations of both the n=-2 scale-free model and the cold
dark matter model, we find that Q at late times is not constant but increases
with wavenumber far into the nonlinear regime. Self-similar scaling also does not
hold as rigorously for the three-point function as for the two-point function in
the n=-2 simulation; this is perhaps a manifestation of the finite simulation
volume. We suggest that a better understanding of the behavior of the two- and
three-point correlation functions in the nonlinear regime lies in the link to the
density profiles of dark matter halos. We demonstrate and quantify how the slopes
of the correlation functions are affected by the slope of the halo profiles using
simple halo shapes and analytic clustering models.
PMID- 10688760
TI - Does Deuterium Enable the Formation of Primordial Brown Dwarfs?
AB - We investigate thermal and dynamical evolution of a primordial gas cloud with an
updated deuterium chemistry. We consider a fragment of a postshock-cooled sheet
that is expected to form by collapse of a massive cloud ( greater, similar108 M
middle dot in circle) and by blast waves due to supernova explosions. At first we
investigate molecule formation in a primordial shock. We show that almost all
deuterium can be converted to HD within the age of the universe at the collapsed
redshift in the case of a cloud that has a virial temperature of approximately
106 K and collapses at z>1. When the postshock sheet fragments owing to
gravitational instability, the fractional H2 and HD abundances become
approximately 10-2 and approximately 10-5, respectively, which are 103-104 times
higher than the result of molecule formation in the expanding universe after
recombination. To study the subsequent evolution of a fragment, we performed one
dimensional simulations of a spherical/cylindrical cloud, of which initial
conditions (e.g., fractional abundances of chemical composition, temperature) are
derived from the result of the shock. It is found that, in case of a cylindrical
collapse, the cooling by HD molecules keeps the temperature of the cloud less
than 100 K and the cloud evolves almost isothermally. When the cloud becomes
optically thick to the HD line emission ( approximately 1010 cm-3) and the
gravitational fragmentation of the cylindrical cloud becomes effective, the Jeans
mass becomes comparable to 0.1 M middle dot in circle. This series of processes
enables the formation of primordial low-mass stars, and possibly brown dwarfs, in
primordial gas clouds.
PMID- 10688761
TI - Detection of an X-Ray Hot Region in the Virgo Cluster of Galaxies with ASCA.
AB - Based on mapping observations with ASCA, an unusual hot region with a spatial
extent of 1 deg2 was discovered between M87 and M49 at a center coordinate of
R.A.=12h27m36s and decl.=9&j0;18' (J2000). The X-ray emission from the region has
a 2-10 keV flux of 1x10-11 ergs s-1 cm-2 and a temperature of kT greater,
similar4 keV, which is significantly higher than that in the surrounding medium
of approximately 2 keV. The internal thermal energy in the hot region is
estimated to be VnkT approximately 1060 ergs with a gas density of approximately
10-4 cm-3. A power-law spectrum with a photon index of 1.7-2.3 is also allowed by
the data. The hot region suggests there is an energy input due to a shock that is
probably caused by the motion of the gas associated with M49, infalling toward
the M87 cluster with a velocity greater, similar1000 km s-1.
PMID- 10688762
TI - Evidence for Stellar Streaming in the Cores of Elliptical Galaxies: A Kinematic
Signature of Mergers?
AB - We present evidence for non-Gaussian velocity fields within the cores of luminous
elliptical galaxies. This evidence is based on high signal-to-noise ratio, medium
resolution spectroscopy of the cores of early-type members of the Virgo and Coma
Clusters obtained with the Wisconsin-Indiana-Yale-NOAO 3.5 m telescope. The Virgo
data were acquired using an integral-field unit (DensePak), which allows the
velocity field to be sampled over a variety of spatial scales. The Coma data were
obtained through single 2&arcsec; diameter fibers. The cross-correlation profiles
of luminous elliptical galaxies show considerable structure, often having several
features with amplitudes as high as 10% that of the cross-correlation peak
itself. This structure is most obvious within a radius of 1&farcs;5 (at Virgo),
or =100 pc, and is nearly undetectable when the data are binned over R<15", or
=1 kpc. Similar features are found in the single-fiber spectra of the luminous
elliptical galaxies in the Coma Cluster, suggesting that they are ubiquitous in
giant elliptical galaxies. Interestingly, only the most luminous elliptical
galaxies show these phenomena; the central regions of lower luminosity elliptical
galaxies have regular Gaussian-like profiles. We interpret this kinematic
structure as "stellar streaming" and suggest that these phenomena could be a
relic signature of the merger history of luminous elliptical galaxies.
PMID- 10688763
TI - A Near-Infrared Photometric Plane for Elliptical Galaxies and Bulges of Spiral
Galaxies.
AB - We report the existence of a single plane in the space of global photometric
parameters describing elliptical galaxies and the bulges of early-type spiral
galaxies. The three parameters that define the plane are obtained by fitting the
Sersic form to the brightness distribution obtained from near-infrared K-band
images. We find, from the range covered by their shape parameters, that the
elliptical galaxies form a more homogeneous population than the bulges. Known
correlations like the Kormendy relation are projections of the photometric plane.
The existence of the plane has interesting implications for bulge formation
models.
PMID- 10688764
TI - High-Resolution Rotation Curves of Low Surface Brightness Galaxies.
AB - High-resolution Halpha rotation curves are presented for five low surface
brightness galaxies. These Halpha rotation curves have shapes different from
those previously derived from H i observations, probably because of the higher
spatial resolution of the Halpha observations. The Halpha rotation curves rise
more steeply in the inner parts than the H i rotation curves, and they reach a
flat part beyond about two disk scale lengths. With radii expressed in optical
disk scale lengths, the rotation curves of the low surface brightness galaxies
presented here and those of the high surface brightness galaxies have almost
identical shapes. Mass modeling shows that the contribution of the stellar
component to the rotation curves may be scaled to explain most of the inner parts
of the rotation curves, albeit with high stellar mass-to-light ratios. On the
other hand, well-fitting mass models can also be obtained with lower
contributions of the stellar disk. These observations suggest that the luminous
mass density and the total mass density are coupled in the inner parts of these
galaxies.
PMID- 10688765
TI - Screw Instability and the Blandford-Znajek Mechanism.
AB - When magnetic field lines thread a rotating black hole's horizon and connect with
remote astrophysical loads, the rotational energy of the black hole can be
extracted through the Blandford-Znajek mechanism. Due to the rotation of the
black hole, the magnetic field lines are twisted and toroidal components are
generated. Thus, poloidal electric currents are induced and the black hole's
rotational energy is transported to the astrophysical loads through Poynting
flux. The Blandford-Znajek mechanism has been considered to be a possible process
for powering extragalactic jets. In this Letter, we show that because of the
screw instability of the magnetic field, the toroidal components of the magnetic
field, and thus the poloidal currents, cannot exceed the limits given by the
Kruskal-Shafranov criterion. This significantly lowers the power of the Blandford
Znajek mechanism when the loads are far from the black hole. So the Blandford
Znajek mechanism can only work efficiently within the neighborhood of the black
hole. The implications of the results for the scenario of extragalactic jets
powered by the Blandford-Znajek mechanism are discussed.
PMID- 10688766
TI - An Intermittent Star Formation History in a "Normal" Disk Galaxy: The Milky Way.
AB - The star formation rate history of the Milky Way is derived using the
chromospheric age distribution for 552 stars in the solar neighborhood. The
stars' sample birth sites are distributed over a very large range of distances
because of orbital diffusion and so give an estimate of the global star formation
rate history. The derivation incorporates the metallicity dependence of
chromospheric emission at a given age and corrections to account for
incompleteness, scale height-age correlations, and stellar evolutionary effects.
We find fluctuations in the global star formation rate with amplitudes greater
than a factor of 2-3 on timescales less than 0.2-1 Gyr. The actual history is
likely to be more bursty than found here because of the smearing effect of age
uncertainties. There is some evidence for a slow secular increase in the star
formation rate, perhaps a record of the accumulation history of our Galaxy. A
smooth, nearly constant star formation rate history is strongly ruled out,
confirming the result first discovered by Barry using a smaller sample and a
different age calibration. This result suggests that galaxies can fluctuate
coherently on large scales.
PMID- 10688767
TI - Relativistic Jets from Collapsars.
AB - Using a collapsar progenitor model of MacFadyen & Woosley, we have simulated the
propagation of an axisymmetric jet through a collapsing rotating massive star
with the GENESIS multidimensional relativistic hydrodynamic code. The jet forms
as a consequence of an assumed (constant or variable) energy deposition in the
range of 1050-1051 ergs s-1 within a 30 degrees cone around the rotation axis.
The jet flow is strongly beamed (approximately less than a few degrees),
spatially inhomogeneous, and time dependent. The jet reaches the surface of the
stellar progenitor (R*=2.98x1010 cm) intact. At breakout, the maximum Lorentz
factor of the jet flow is 33. After breakout, the jet accelerates into the
circumstellar medium, whose density is assumed to decrease exponentially and then
become constant, rhoext=10-5 g cm-3. Outside the star, the flow begins to expand
laterally also (v approximately c), but the beam remains very well collimated. At
a distance of 2.54 R*, where the simulation ends, the Lorentz factor has
increased to 44.
PMID- 10688768
TI - Nucleosynthesis and Clump Formation in a Core-Collapse Supernova.
AB - High-resolution two-dimensional simulations were performed for the first 5
minutes of the evolution of a core-collapse supernova explosion in a 15 M middle
dot in circle blue supergiant progenitor. The computations start shortly after
bounce and include neutrino-matter interactions by using a lightbulb
approximation for the neutrinos and a treatment of the nucleosynthesis due to
explosive silicon and oxygen burning. We find that newly formed iron-group
elements are distributed throughout the inner half of the helium core by Rayleigh
Taylor instabilities at the (Ni + Si)/O and (C + O)/He interfaces, seeded by
convective overturn during the early stages of the explosion. Fast-moving nickel
mushrooms with velocities up to approximately 4000 km s-1 are observed. This
offers a natural explanation for the mixing required in light-curve and spectral
synthesis studies of Type Ib explosions. A continuation of the calculations to
later times, however, indicates that the iron velocities observed in SN 1987A
cannot be reproduced because of a strong deceleration of the clumps in the dense
shell left behind by the shock at the He/H interface.
PMID- 10688769
TI - Induction of Supernova-like Explosions by Gamma-Ray Bursts in Close Binary
Systems.
AB - We propose that a gamma-ray burst in one member of a binary may induce a
supernova-like explosion of a close, white dwarf companion. Such an explosion
might be brought about in rather light companions, which cannot undergo the
standard accretion-induced explosion. This would give some supernovae associated
with gamma-ray bursts an appearance rather unlike that of the typical Type I
supernova. GRB 980425, if indeed associated with SN 1998bw, is too weak to have
produced the latter through our proposed mechanism.
PMID- 10688770
TI - BeppoSAX and Chandra Observations of SAX J0103.2-7209 = 2E 0101.5-7225: A New
Persistent 345 Second X-Ray Pulsar in the Small Magellanic Cloud.
AB - We report the results of a 1998 July BeppoSAX observation of a field in the Small
Magellanic Cloud which led to the discovery of approximately 345 s pulsations in
the X-ray flux of SAX J0103.2-7209. The BeppoSAX X-ray spectrum is well fitted by
an absorbed power law with a photon index of approximately 1.0 plus a blackbody
component with kT=0.11 keV. The unabsorbed luminosity in the 2-10 keV energy
range is approximately 1.2x1036 ergs s-1. In a very recent Chandra observation,
the 345 s pulsations are also detected. The available period measurements provide
a constant period derivative of -1.7 s yr-1 over the last 3 years, making SAX
J0103.2-7209 one of the most rapidly spinning up X-ray pulsars known. The
BeppoSAX position (30&arcsec; uncertainty radius) is consistent with that of the
Einstein source 2E 0101.5-7225 and the ROSAT source RX J0103.2-7209. This source
was detected at a luminosity level of a few times 1035-1036 ergs s-1 in all data
sets of past X-ray missions since 1979. The ROSAT HRI and Chandra positions are
consistent with that of a mV=14.8 Be spectral-type star already proposed as the
likely optical counterpart of 2E 0101.5-7225. We briefly report and discuss
photometric and spectroscopic data carried out at the ESO telescopes 2 days
before the BeppoSAX observation. We conclude that SAX J0103.2-7209 and 2E 0101.5
7225 are the same source: a relatively young and persistent X-ray pulsar in the
SMC.
PMID- 10688771
TI - Radio Pulsar Death Line Revisited: Is PSR J2144-3933 Anomalous?
AB - We reinvestigate the radio pulsar "death lines" within the framework of two
different types of the polar cap acceleration models, i.e., the vacuum gap model
and the space-charge-limited flow model, with either curvature radiation or
inverse Compton scattering photons as the source of pairs. General relativistic
frame dragging is taken into account in both models. We find that the inverse
Compton scattering-induced space-charge-limited flow model can sustain strong
pair production in some long-period pulsars, which allows the newly detected 8.5
s pulsar PSR J2144-3933 to be radio loud without assuming special neutron star
equations of state or ad hoc magnetic field configurations.
PMID- 10688772
TI - r-Mode Oscillations in Rotating Magnetic Neutron Stars.
AB - We show that r-mode oscillations distort the magnetic fields of neutron stars and
that their occurrence is likely to be limited by this interaction. If the field
is greater, similar1016(Omega/OmegaB) G, where Omega and OmegaB are the angular
velocities of the star and at which mass shedding occurs, r-mode oscillations
cannot occur. Much weaker fields will prevent gravitational radiation from
exciting r-mode oscillations or will damp them on a relatively short timescale by
extracting energy from the modes faster than gravitational-wave emission can pump
energy into them. For example, a 1010 G poloidal magnetic field that threads the
star's superconducting core is likely to prevent the l=2 mode from being excited
unless Omega exceeds 0.35OmegaB. If Omega is larger than 0.35OmegaB initially,
the l=2 mode may be excited but is likely to decay rapidly once Omega falls below
0.35OmegaB, which happens in less, similar15 days if the saturation amplitude is
greater, similar0.1. The r-mode oscillations may play an important role in
determining the structure of neutron star magnetic fields.
PMID- 10688773
TI - Asteroseismology and Oblique Pulsator Model of beta Cephei.
AB - We discuss the oscillation features of beta Cephei, which is a magnetic star in
which the magnetic axis seems to be oblique to the rotation axis. We interpret
the observed equidistant fine structure of the frequency spectrum as a
manifestation of a magnetic perturbation of an eigenmode, which would be a radial
mode in the absence of the magnetic field. Besides these frequency components, we
interpret another peak in the frequency spectrum as an independent quadrupole
mode. By this mode identification, we deduce the mass, evolutionary stage,
rotational frequency, magnetic field strength, and geometrical configuration of
beta Cep.
PMID- 10688774
TI - A Third Star in the T Tauri System.
AB - New speckle holographic images of the T Tauri infrared companion (T Tauri IRC; T
Tauri S) reveal it to be a double system with a sky-projected separation of
0&farcs;05, corresponding to a linear distance of 7 AU. The presence of this
third star may account for the relative paucity of dust surrounding the IRC.
PMID- 10688775
TI - Water Ice in 2060 Chiron and Its Implications for Centaurs and Kuiper Belt
Objects.
AB - We report the detection of water ice in the Centaur 2060 Chiron, based on near
infrared spectra (1.0-2.5 um) taken with the 3.8 m United Kingdom Infrared
Telescope and the 10 m Keck Telescope. The appearance of this ice is correlated
with the recent decline in Chiron's cometary activity: the decrease in the coma
cross section allows previously hidden solid-state surface features to be seen.
We predict that water ice is ubiquitous among Centaurs and Kuiper Belt objects,
but its surface coverage varies from object to object and thus determines its
detectability and the occurrence of cometary activity.
PMID- 10688776
TI - Detection of CO and Ethane in Comet 21P/Giacobini-Zinner: Evidence for Variable
Chemistry in the Outer Solar Nebula.
AB - Ethane and carbon monoxide were detected in a short-period comet of probable
Kuiper Belt origin. Ethane is substantially less abundant compared with Hyakutake
and Hale-Bopp, two comets from the giant-planet region of the solar nebula,
suggesting a heliocentric gradient in ethane in precometary ices. It is argued
that processing by X-rays from the young Sun may be responsible.
PMID- 10688777
TI - The Lowest Submillimeter-Wave Transitions of CH: The Laboratory Measurement of
the Rest Frequencies.
AB - The lowest rotational transitions of CH in the ground electronic state (X2Pi),
J=3&solm0;2, N=1<--J=1&solm0;2, N=1, have been observed in the laboratory in the
532.8 and 536.8 GHz regions. All six possible hyperfine components are
identified, and the precise transition frequencies are determined.
PMID- 10688778
TI - Patients' voices: the powerful sound in the stem cell debate.
AB - Millions of patients may benefit from the applications of stem cell research,
although there is disagreement about whether public funds should be used to
develop the science. Patients have been key to winning political support. Acting
as advocates, they have contended that public investment will speed the research
and bring accountability to biomedical technology. A political dispute about the
new research, which holds the potential for cures to devastating diseases and to
foster healthy aging, shows the need to respect public sensibilities and to court
public approval, as well as the importance of involving patients in debates where
the methods of biomedical discoveries and ethical beliefs collide.
PMID- 10688779
TI - A time for restraint.
AB - The debate on the use of human embryos for research will be one of the more
important issues of the 21st century. Unlike recombinant DNA technology,
embryonic stem cell research most probably will result in the destruction of
living embryos. Many people consider this research immoral, illegal, and
unnecessary. Therefore, it is imperative to proceed cautiously. Federal funding
of research using human embryos or pluripotent cells derived from them would be
inappropriate until further resolution of the ethical issues has been achieved.
PMID- 10688780
TI - Europe confronts the embryonic stem cell research challenge.
AB - Europe's historic plurality and the lack of a commonly accepted definition of the
moral status of the embryo have led to varying regulation in European countries.
Council of Europe and European Union legislation, based on fundamental ethical
principles, does exist for specific issues, such as prohibition against producing
embryos solely for research. Such principles have recently been elucidated by the
European Group on Ethics in Science and New Technologies. Newly emerging research
techniques are beginning to cause reconsideration of the regulation of embryo
research in Europe.
PMID- 10688781
TI - Out of Eden: stem cells and their niches.
AB - Stem cells are currently in the news for two reasons: the successful cultivation
of human embryonic stem cell lines and reports that adult stem cells can
differentiate into developmentally unrelated cell types, such as nerve cells into
blood cells. Both intrinsic and extrinsic signals regulate stem cell fate and
some of these signals have now been identified. Certain aspects of the stem cell
microenvironment, or niche, are conserved between tissues, and this can be
exploited in the application of stem cells to tissue replacement therapy.
PMID- 10688782
TI - Stem cells in epithelial tissues.
AB - Most, if not all, epithelial tissues contain stem cells. They are responsible for
normal tissue renewal or for regeneration following damage. Our present knowledge
of their properties is limited and is mainly derived from studies of cell
kinetics and from clonal analysis.
PMID- 10688783
TI - Mammalian neural stem cells.
AB - Neural stem cells exist not only in the developing mammalian nervous system but
also in the adult nervous system of all mammalian organisms, including humans.
Neural stem cells can also be derived from more primitive embryonic stem cells.
The location of the adult stem cells and the brain regions to which their progeny
migrate in order to differentiate remain unresolved, although the number of
viable locations is limited in the adult. The mechanisms that regulate endogenous
stem cells are poorly understood. Potential uses of stem cells in repair include
transplantation to repair missing cells and the activation of endogenous cells to
provide "self-repair. " Before the full potential of neural stem cells can be
realized, we need to learn what controls their proliferation, as well as the
various pathways of differentiation available to their daughter cells.
PMID- 10688784
TI - Why stem cells?
AB - Stem cells are viewed from the perspectives of their function, evolution,
development, and cause. Counterintuitively, most stem cells may arise late in
development, to act principally in tissue renewal, thus ensuring an organism's
long-term survival. Surprisingly, recent reports suggest that tissue-specific
adult stem cells have the potential to contribute to replenishment of multiple
adult tissues.
PMID- 10688785
TI - Translating stem and progenitor cell biology to the clinic: barriers and
opportunities.
AB - Stem cells are the natural units of embryonic generation, and also adult
regeneration, of a variety of tissues. Recently, the list of tissues that use the
model of differentiation from stem to progenitor to mature cell has increased
from blood to include a variety of tissues, including both central and peripheral
nervous systems and skeletal muscle; it is also possible that all organs and
tissues are derived from, and still contain, stem cells. Because the number and
activities of stem cells and their progeny are homeostatically regulated,
clinical stem cell transplantation could greatly add to the physician's
armamentarium against degenerative diseases.
PMID- 10688786
TI - The atom-cavity microscope: single atoms bound in orbit by single photons
AB - The motion of individual cesium atoms trapped inside an optical resonator is
revealed with the atom-cavity microscope (ACM). A single atom moving within the
resonator generates large variations in the transmission of a weak probe laser,
which are recorded in real time. An inversion algorithm then allows individual
atom trajectories to be reconstructed from the record of cavity transmission and
reveals single atoms bound in orbit by the mechanical forces associated with
single photons. In these initial experiments, the ACM yields 2-micrometer spatial
resolution in a 10-microsecond time interval. Over the duration of the
observation, the sensitivity is near the standard quantum limit for sensing the
motion of a cesium atom.
PMID- 10688787
TI - An oral vaccine against NMDAR1 with efficacy in experimental stroke and epilepsy.
AB - The brain is generally considered immunoprivileged, although increasing examples
of immunological responses to brain antigens, neuronal expression of major
histocompatibility class I genes, and neurological autoimmunity have been
recognized. An adeno-associated virus (AAV) vaccine generated autoantibodies that
targeted a specific brain protein, the NR1 subunit of the N-methyl-D-aspartate
(NMDA) receptor. After peroral administration of the AAV vaccine, transgene
expression persisted for at least 5 months and was associated with a robust
humoral response in the absence of a significant cell-mediated response. This
single-dose vaccine was associated with strong anti-epileptic and neuroprotective
activity in rats for both a kainate-induced seizure model and also a middle
cerebral artery occlusion stroke model at 1 to 5 months following vaccination.
Thus, a vaccination strategy targeting brain proteins is feasible and may have
therapeutic potential for neurological disorders.
PMID- 10688788
TI - Shaped ceramics with tunable magnetic properties from metal-containing polymers
AB - A shaped, magnetic ceramic was obtained from a metal-containing polymer network,
which was synthesized by thermal polymerization of a metal-containing
organosilicon monomer. Pyrolysis of a cylinder, shape, or film of the metal
containing polymer precursor produced a low-density magnetic ceramic replica in
high yield. The magnetic properties of the shaped ceramic could be tuned between
a superparamagnetic and ferromagnetic state by controlling the pyrolysis
conditions, with the particular state dependent on the size of iron nanoclusters
homogeneously dispersed throughout the carbosilane-graphitic-silicon nitride
matrix. These results indicate that cross-linked metal-containing polymers may be
useful precursors to ceramic monoliths with tailorable magnetic properties.
PMID- 10688789
TI - Superplastic extensibility of nanocrystalline copper at room temperature
AB - A bulk nanocrystalline (nc) pure copper with high purity and high density was
synthesized by electrodeposition. An extreme extensibility (elongation exceeds
5000%) without a strain hardening effect was observed when the nc copper specimen
was rolled at room temperature. Microstructure analysis suggests that the
superplastic extensibility of the nc copper originates from a deformation
mechanism dominated by grain boundary activities rather than lattice dislocation,
which is also supported by tensile creep studies at room temperature. This
behavior demonstrates new possibilities for scientific and technological
advancements with nc materials.
PMID- 10688790
TI - Room temperature magnetic quantum cellular automata
AB - All computers process information electronically. A processing method based on
magnetism is reported here, in which networks of interacting submicrometer
magnetic dots are used to perform logic operations and propagate information at
room temperature. The logic states are signaled by the magnetization direction of
the single-domain magnetic dots; the dots couple to their nearest neighbors
through magnetostatic interactions. Magnetic solitons carry information through
the networks, and an applied oscillating magnetic field feeds energy into the
system and serves as a clock. These networks offer a several thousandfold
increase in integration density and a hundredfold reduction in power dissipation
over current microelectronic technology.
PMID- 10688791
TI - Rippling instability of a collapsing bubble
AB - When a bubble of air rises to the top of a highly viscous liquid, it forms a dome
shaped protuberance on the free surface. Unlike a soap bubble, it bursts so
slowly as to collapse under its own weight simultaneously, and folds into a wavy
structure. This rippling effect occurs for both elastic and viscous sheets, and a
theory for its onset is formulated. The growth of the corrugation is governed by
the competition between gravitational and bending (shearing) forces and is
exhibited for a range of densities, stiffnesses (viscosities), and sizes-a result
that arises less from dynamics than from geometry, suggesting a wide validity. A
quantitative expression for the number of ripples is presented, together with
experimental results that support the theoretical predictions.
PMID- 10688792
TI - Control of thickness and orientation of solution-grown silicon nanowires
AB - Bulk quantities of defect-free silicon (Si) nanowires with nearly uniform
diameters ranging from 40 to 50 angstroms were grown to a length of several
micrometers with a supercritical fluid solution-phase approach. Alkanethiol
coated gold nanocrystals (25 angstroms in diameter) were used as uniform seeds to
direct one-dimensional Si crystallization in a solvent heated and pressurized
above its critical point. The orientation of the Si nanowires produced with this
method could be controlled with reaction pressure. Visible photoluminescence due
to quantum confinement effects was observed, as were discrete optical transitions
in the ultraviolet-visible absorbance spectra.
PMID- 10688793
TI - Atomic-scale structure and catalytic reactivity of the RuO(2)(110) surface
AB - The structure of RuO(2)(110) and the mechanism for catalytic carbon monoxide
oxidation on this surface were studied by low-energy electron diffraction,
scanning tunneling microscopy, and density-functional calculations. The
RuO(2)(110) surface exposes bridging oxygen atoms and ruthenium atoms not capped
by oxygen. The latter act as coordinatively unsaturated sites-a hypothesis
introduced long ago to account for the catalytic activity of oxide surfaces-onto
which carbon monoxide can chemisorb and from where it can react with neighboring
lattice-oxygen to carbon dioxide. Under steady-state conditions, the consumed
lattice-oxygen is continuously restored by oxygen uptake from the gas phase. The
results provide atomic-scale verification of a general mechanism originally
proposed by Mars and van Krevelen in 1954 and are likely to be of general
relevance for the mechanism of catalytic reactions at oxide surfaces.
PMID- 10688794
TI - Molecular architecture and evolution of a modular spider silk protein gene.
AB - Spider flagelliform silk is one of the most elastic natural materials known.
Extensive sequencing of spider silk genes has shown that the exons and introns of
the flagelliform gene underwent intragenic concerted evolution. The intron
sequences are more homogenized within a species than are the exons. This pattern
can be explained by extreme mutation and recombination pressures on the
internally repetitive exons. The iterated sequences within exons encode protein
structures that are critical to the function of silks. Therefore, attributes that
make silks exceptional biomaterials may also hinder the fixation of optimally
adapted protein sequences.
PMID- 10688795
TI - Effects of environment on compensatory mutations to ameliorate costs of
antibiotic resistance.
AB - Most types of antibiotic resistance impose a biological cost on bacterial
fitness. These costs can be compensated, usually without loss of resistance, by
second-site mutations during the evolution of the resistant bacteria in an
experimental host or in a laboratory medium. Different fitness-compensating
mutations were selected depending on whether the bacteria evolved through serial
passage in mice or in a laboratory medium. This difference in mutation spectra
was caused by either a growth condition-specific formation or selection of the
compensated mutants. These results suggest that bacterial evolution to reduce the
costs of antibiotic resistance can take different trajectories within and outside
a host.
PMID- 10688796
TI - Parental care and clutch sizes in North and South American birds.
AB - The evolutionary causes of small clutch sizes in tropical and Southern Hemisphere
regions are poorly understood. Alexander Skutch proposed 50 years ago that higher
nest predation in the south constrains the rate at which parent birds can deliver
food to young and thereby constrains clutch size by limiting the number of young
that parents can feed. This hypothesis for explaining differences in clutch size
and parental behaviors between latitudes has remained untested. Here, a detailed
study of bird species in Arizona and Argentina shows that Skutch's hypothesis
explains clutch size variation within North and South America. However, neither
Skutch's hypothesis nor two major alternatives explain differences between
latitudes.
PMID- 10688797
TI - Translocation of C. elegans CED-4 to nuclear membranes during programmed cell
death.
AB - The Caenorhabditis elegans Bcl-2-like protein CED-9 prevents programmed cell
death by antagonizing the Apaf-1-like cell-death activator CED-4. Endogenous CED
9 and CED-4 proteins localized to mitochondria in wild-type embryos, in which
most cells survive. By contrast, in embryos in which cells had been induced to
die, CED-4 assumed a perinuclear localization. CED-4 translocation induced by the
cell-death activator EGL-1 was blocked by a gain-of-function mutation in ced-9
but was not dependent on ced-3 function, suggesting that CED-4 translocation
precedes caspase activation and the execution phase of programmed cell death.
Thus, a change in the subcellular localization of CED-4 may drive programmed cell
death.
PMID- 10688798
TI - Regulation of cell fate decision of undifferentiated spermatogonia by GDNF.
AB - The molecular control of self-renewal and differentiation of stem cells has
remained enigmatic. Transgenic loss-of-function and overexpression models now
show that the dosage of glial cell line-derived neurotrophic factor (GDNF),
produced by Sertoli cells, regulates cell fate decisions of undifferentiated
spermatogonial cells that include the stem cells for spermatogenesis. Gene
targeted mice with one GDNF-null allele show depletion of stem cell reserves,
whereas mice overexpressing GDNF show accumulation of undifferentiated
spermatogonia. They are unable to respond properly to differentiation signals and
undergo apoptosis upon retinoic acid treatment. Nonmetastatic testicular tumors
are regularly formed in older GDNF-overexpressing mice. Thus, GDNF contributes to
paracrine regulation of spermatogonial self-renewal and differentiation.
PMID- 10688799
TI - General acid-base catalysis in the mechanism of a hepatitis delta virus ribozyme.
AB - Many protein enzymes use general acid-base catalysis as a way to increase
reaction rates. The amino acid histidine is optimized for this function because
it has a pK(a) (where K(a) is the acid dissociation constant) near physiological
pH. The RNA enzyme (ribozyme) from hepatitis delta virus catalyzes self-cleavage
of a phosphodiester bond. Reactivity-pH profiles in monovalent or divalent
cations, as well as distance to the leaving-group oxygen, implicate cytosine 75
(C75) of the ribozyme as the general acid and ribozyme-bound hydrated metal
hydroxide as the general base in the self-cleavage reaction. Moreover, C75 has a
pK(a) perturbed to neutrality, making it "histidine-like." Anticooperative
interaction is observed between protonated C75 and a metal ion, which serves to
modulate the pK(a) of C75. General acid-base catalysis expands the catalytic
repertoire of RNA and may provide improved rate acceleration.
PMID- 10688800
TI - Translocation of Helicobacter pylori CagA into gastric epithelial cells by type
IV secretion.
AB - The Gram-negative bacterium Helicobacter pylori is a causative agent of gastritis
and peptic ulcer disease in humans. Strains producing the CagA antigen (cagA(+))
induce strong gastric inflammation and are strongly associated with gastric
adenocarcinoma and MALT lymphoma. We show here that such strains translocate the
bacterial protein CagA into gastric epithelial cells by a type IV secretion
system, encoded by the cag pathogenicity island. CagA is tyrosine-phosphorylated
and induces changes in the tyrosine phosphorylation state of distinct cellular
proteins. Modulation of host cells by bacterial protein translocation adds a new
dimension to the chronic Helicobacter infection with yet unknown consequences.
PMID- 10688801
TI - Virus-induced neuronal apoptosis blocked by the herpes simplex virus latency
associated transcript.
AB - Latent infections with periodic reactivation are a common outcome after acute
infection with many viruses. The latency-associated transcript (LAT) gene is
required for wild-type reactivation of herpes simplex virus (HSV). However, the
underlying mechanisms remain unclear. In rabbit trigeminal ganglia, extensive
apoptosis occurred with LAT(-) virus but not with LAT(+) viruses. In addition, a
plasmid expressing LAT blocked apoptosis in cultured cells. Thus, LAT promotes
neuronal survival after HSV-1 infection by reducing apoptosis.
PMID- 10688802
TI - Porphyrin and phthalocyanine antiscrapie compounds.
AB - The transmissible spongiform encephalopathies (TSEs) are fatal, neurodegenerative
diseases for which no effective treatments are available. The likelihood that a
bovine form of TSE has crossed species barriers and infected humans underscores
the urgent need to identify anti-TSE drugs. Certain cyclic tetrapyrroles
(porphyrins and phthalocyanines) have recently been shown to inhibit the in vitro
formation of PrP-res, a protease-resistant protein critical for TSE pathogenesis.
We now report that treatment of TSE-infected animals with three such compounds
increased survival time from 50 to 300%. The significant inhibition of TSE
disease by structurally dissimilar tetrapyrroles identifies these compounds as
anti-TSE drugs.
PMID- 10688803
TI - Mirror-image confusion in single neurons of the macaque inferotemporal cortex.
AB - Humans and animals confuse lateral mirror images, such as the letters "b" and
"d," more often than vertical mirror images, such as the letters "b" and "p."
Experiments were performed to find a neural correlate of this phenomenon.
Visually responsive pattern-selective neurons in the inferotemporal cortex of
macaque monkeys responded more similarly to members of a lateral mirror-image
pair than to members of a vertical mirror-image pair. The phenomenon developed
within 20 milliseconds of the onset of the visual response and persisted to its
end. It occurred during presentation of stimuli both at the fovea and in the
periphery.
PMID- 10688804
TI - Role of hemostatic gene polymorphisms in venous and arterial thrombotic disease.
PMID- 10688805
TI - Characterization of a murine monoclonal antibody that mimics heparin-induced
thrombocytopenia antibodies.
AB - Antibodies to PF4/heparin can be demonstrated in almost all patients with heparin
induced thrombocytopenia/thrombosis (HIT/HITT) and in some persons exposed to
heparin who do not have clinical manifestations. The role of anti-PF4/heparin
antibodies in the pathogenesis of HIT/HITT has been difficult to establish
because the antibodies found in serum are generally polyclonal and polyspecific.
To circumvent this problem, we developed a murine monoclonal antibody (mAb) to
human (h) PF4/heparin complexes. A monoclonal IgG(2bkappa )antibody (designated
KKO) was identified that bound specifically to hPF4/heparin complexes. Maximal
binding of KKO to hPF4/heparin complexes occurred at similar molar ratios of
PF4:heparin observed for HIT/HITT antibodies. KKO also bound to hPF4 in
association with other glycosaminoglycans. Platelet activation by KKO required
heparin and was abrogated by blockade of FcgammaRIIA. In the presence of PF4, KKO
bound to endothelial cells, but not to CHO cells lacking heparan sulfate
proteoglycans. Variants of PF4 complexed to heparin were recognized equally well
by KKO and HIT/HITT sera. KKO competes for binding with a subset of HIT/HITT
antibodies that are relatively spared by mutations in the 3rd domain of PF4. The
nucleotide and predicted amino acid sequences of KKO and RTO, a murine anti-hPF4
mAb that does not require heparin for binding, revealed no obvious relationship
in either the heavy- or the light-chain immunoglobulin variable regions. These
studies suggest that KKO recapitulates the antigenic and functional specificity
of a subset of HIT/HITT antibodies and may, therefore, provide insight into the
pathogenesis of thrombocytopenia and thrombosis in affected persons. (Blood.
2000;95:1533-1540)
PMID- 10688806
TI - Leukemia initiated by PMLRARalpha: the PML domain plays a critical role while
retinoic acid-mediated transactivation is dispensable.
AB - The most common chromosomal translocation in acute promyelocytic leukemia (APL),
t15;17(q22;q21), creates PMLRARalpha and RARalphaPML fusion genes. We previously
developed a mouse model of APL by expressing PMLRARalpha in murine myeloid cells.
In order to examine the mechanisms by which PMLRARalpha can initiate leukemia, we
have now generated transgenic mice expressing PMLRARalpham4 and RARalpham4,
proteins that are unable to activate transcription in response to retinoic acid.
PMLRARalpham4 transgenic mice developed myeloid leukemia, demonstrating that
transcriptional activation by PMLRARalpha is not required for leukemic
transformation. The characteristics of the leukemias arising in the PMLRARalpham4
transgenic mice varied from those previously observed in our PMLRARalpha
transgenic mice, indicating that ligand responsiveness may influence the
phenotype of the leukemic cells. The leukemias that arose in PMLRARalpham4
transgenic mice did not differentiate in response to retinoic acid therapy. This
result supports the hypothesis that a major therapeutic effect of retinoic acid
is mediated directly through the PMLRARalpha protein. However, a variable effect
on survival suggested that this agent may be of some benefit in APL even when
leukemic cells are resistant to its differentiative effects. Transgenic mice
expressing high levels of RARalpham4 have not developed leukemia, providing
evidence that the PML domain of PMLRARalpha plays a specific and critical role in
the pathogenesis of APL. (Blood. 2000;95:1541-1550)
PMID- 10688807
TI - GCP-2-induced internalization of IL-8 receptors: hierarchical relationships
between GCP-2 and other ELR(+)-CXC chemokines and mechanisms regulating CXCR2
internalization and recycling.
AB - The chemotactic potencies of ELR(+)-CXC chemokines during acute inflammation are
regulated by their binding affinities and by their ability to activate,
desensitize, and internalize their specific receptors, CXCR1 and CXCR2. To gain
insight into the fine mechanisms that control acute inflammatory processes, we
have focused in this study on the highly potent ELR(+)-CXC chemokine Granulocyte
Chemotactic Protein 2 (GCP-2), and on its ability to control the cell surface
expression of CXCR1 and CXCR2. Although GCP-2 has been considered an effective
ligand for both CXCR1 and CXCR2, our findings demonstrated that it was a potent
inducer of CXCR2 internalization only. A functional hierarchy was shown to exist
between GCP-2 and 2 other ELR(+)-CXC chemokines, IL-8 and NAP-2, in their
abilities to induce CXCR1 and CXCR2 internalization, according to the following:
IL-8 > GCP-2 > NAP-2. By the use of pertussis toxin (PTx), it was demonstrated
that the actual events of G(alphai)-coupling to CXCR2 do not have a major role in
the regulation of its internalization. Rather, CXCR2 internalization was shown to
be negatively controlled by induction of signaling events, as indicated by the
promotion of CXCR2 internalization following exposure to wortmannin, a potent
inhibitor of phosphatidylinositol (PI) 3 kinases and PI4 kinases. Furthermore,
our results suggest that rab11(+)-endosomes participate in the trafficking of
CXCR2 through the endocytic pathway, to eventually allow its recycling back to
the plasma membrane. To conclude, our findings shed light on the
interrelationships between GCP-2 and other ELR(+)-CXC chemokines, and determine
the mechanisms involved in the regulation of GCP-2-induced internalization and
recycling of CXCR2. (Blood. 2000;95:1551-1559)
PMID- 10688808
TI - Association between diabetic retinopathy and genetic variations in alpha2beta1
integrin, a platelet receptor for collagen.
AB - Platelets might be involved in the pathogenesis of diabetic microangiopathy. Wide
interindividual variations in the density of a platelet collagen receptor
(alpha2beta1 integrin or glycoprotein Ia/IIa) are reportedly associated with
polymorphism(s) in the gene encoding the alpha subunit of the receptor, including
a Bgl II polymorphism in intron 7. The aim of the present study was to determine
the relationship between the Bgl II polymorphism and the susceptibility to
diabetic microangiopathy. A case-control study comparing 227 patients with type
II diabetes mellitus (119 with versus 108 without diabetic retinopathy) as well
as 169 nondiabetic subjects demonstrated that genotypes with Bgl II (+) allele
had a significant increase in the risk for retinopathy. The odds ratio for Bgl II
(+/+) to Bgl II (-/-) was 3.41 (95% CI, 1.49-7.78, P =.0036) when analysis was
confined to those with a disease duration of diabetes of 10 years or more. The
present study suggests that the presence of a Bg II (+) allele is a genetic risk
factor for diabetic retinopathy. (Blood. 2000;95:1560-1564)
PMID- 10688809
TI - Hemochromatosis genes and other factors contributing to the pathogenesis of
porphyria cutanea tarda.
AB - Inherited and acquired factors have been implicated in the pathogenesis of
porphyria cutanea tarda (PCT), a disorder characterized by a photosensitive
dermatosis and hepatic siderosis. This study, comprising 108 patients with PCT,
was intended to define the role of hemochromatosis gene (HFE) mutations in the
expression of PCT and to determine the contribution of acquired factors including
alcohol, hepatitis C virus (HCV), and estrogen. The 2 known HFE mutations,
cysteine 282 tyrosine (Cys282Tyr) and histidine 63 asparagine (His63Asp), were
detected by polymerase chain reaction, and anti-HCV immunoglobulin G was detected
serologically. Liver biopsies were graded for iron content, inflammation, and
fibrosis. Estimates of alcohol and estrogen use were based on a questionnaire. Of
the PCT patients tested, 19% were homozygous for the Cys282Tyr mutation; controls
were equal to 0.5%. The compound heterozygous genotype was detected in 7% of the
PCT patients; controls were less than 1%. The transferrin saturation, serum
ferritin, and liver iron burden of all PCT patients were higher than those of
nonporphyric controls. The highest values were found in PCT patients homozygous
for the Cys282Tyr mutation. Of the patients studied, 59% were HCV positive
(compared with 1.8% of the population), and 46% consumed more than 70 g of
alcohol daily. Of the female patients, 63% were ingesting estrogens. Hepatic
damage was most marked in patients with the Cys282Tyr/Cys282Tyr genotype who had
HCV and drank heavily. Homozygosity for the Cys282Tyr mutation and HCV are the
greatest risk factors for expression of PCT, and in most patients, more than 1
risk factor was identified. It was common for patients with HCV to consume
alcohol. Patients with PCT should be screened for HFE mutations and for HCV.
(Blood. 2000;95:1565-1571)
PMID- 10688810
TI - Graft versus host disease prophylaxis with low-dose cyclosporine-A reduces the
risk of relapse in children with acute leukemia given HLA-identical sibling bone
marrow transplantation: results of a randomized trial.
AB - Leukemia relapse is a major cause of treatment failure for patients with acute
leukemia given allogeneic bone marrow transplantation (BMT). This study evaluated
whether a reduction of the dosage of cyclosporine-A (Cs-A) used for graft versus
host disease (GVHD) prophylaxis could reduce relapse rate (RR) in children with
acute leukemia given BMT. Fifty-nine children who had transplantation from HLA
identical siblings were randomized to receive Cs-A intravenously at a dosage of 1
mg/kg/d (Cs-A1) or of 3 mg/kg/d (Cs-A3) until patients were able to tolerate oral
intake. Subsequently, both groups received Cs-A orally at a dosage of 6 mg/kg/d,
with discontinuation 5 months after BMT. The probability of developing grade II
IV acute GVHD was 57% for the Cs-A1 group versus 38% for the Cs-A3 group (P
=.06); the probability of developing chronic GVHD was 30% for the Cs-A1 group and
26% for the Cs-A3 group (P = NS). Three patients died of grade IV acute GVHD: 2
were in the Cs-A1 and the third in the Cs-A3 group. The RR was 15% for the Cs-A1
group and 41% for the Cs-A3 group (P =.034); 1-year transplant-related mortality
estimates were 17% and 7%, respectively (P = NS). With a median observation time
of 44 months from BMT, the 5-year event-free survival for children belonging to
Cs-A1 and Cs-A3 groups was 70% and 51%, respectively (P =.15). Our data
demonstrate that the use of low Cs-A doses is associated with a statistically
significant reduction of leukemia relapse, probably due to an increased graft
versus leukemia effect. (Blood. 2000;95:1572-1579)
PMID- 10688811
TI - Patients with myelodysplastic syndromes benefit from palliative therapy with
amifostine, pentoxifylline, and ciprofloxacin with or without dexamethasone.
AB - Thirty-five patients with myelodysplastic syndrome (MDS) were registered on
protocol MDS 96-02 and were receiving continuous therapy with pentoxifylline 800
mg 3 times a day and ciprofloxacin 500 mg twice a day by mouth; dexamethasone was
added to the regimen for the partial responders and the nonresponders after 12
weeks at a dose of 4 mg by mouth every morning for 4 weeks. Amifostine was
administered intravenously 3 times a week at 3 dose levels (200 mg/M(2), 300
mg/M(2), and 400 mg/M(2)) to cohorts of 10 patients each. Therapy has been
continued for 1 year in responders. Twenty-nine have completed at least 12 weeks
of therapy and are available for response evaluation. Of the 21 men and 8 women
(median age, 67 years), 20 had refractory anemia (RA), 3 had RA with ringed
sideroblasts (RARS), 5 had RA with excess blasts (RAEB), and 1 had chronic
myelomonocytic leukemia (CMMoL). Five had secondary MDS. No differences were
noted in response rates among the 3 dose levels. Seven patients did not respond
at all, and 22 showed an improvement in cytopenias (76%). Three had a triple
lineage response, 10 had a double lineage response, and 9 had a single lineage
response (8 of 9 in absolute neutrophil count [ANC] and 1 had more than a 50%
reduction in packed red blood cell transfusions). Fifteen patients responded only
after the addition of dexamethasone, whereas 7 responded before. When examined by
lineage, 19 of 22 showed improved ANC, 11 of 22 demonstrated more than 50%
reduction in blood transfusions, improved Hb levels, or both, and 7 of 22 showed
improvement in platelet counts. Interestingly, the responses were frequently slow
to appear, and continued improvement in counts was seen up to 12 months of
therapy and beyond. This study supports the feasibility of treating patients with
MDS with the unique approach of cytoprotection and anticytokine therapies as well
as the principle that prolonged commitment to treatment is desirable when
noncytotoxic agents are administered. (Blood. 2000;95:1580-1587)
PMID- 10688812
TI - Predictors of therapy-related leukemia and myelodysplasia following autologous
transplantation for lymphoma: an assessment of risk factors.
AB - We analyzed data on 612 patients who had undergone high-dose chemoradiotherapy
(HDT) with autologous stem cell rescue for Hodgkin's disease (HD) and non
Hodgkin's lymphoma (NHL) at the City of Hope National Medical Center, to evaluate
the incidence of therapy-related myelodysplasia (t-MDS) or therapy-related acute
myeloid leukemia (t-AML) and associated risk factors. A retrospective cohort and
a nested case-control study design were used to evaluate the role of
pretransplant therapeutic exposures and transplant conditioning regimens. Twenty
two patients developed morphologic evidence of t-MDS/t-AML. The estimated
cumulative probability of developing morphologic t-MDS/t-AML was 8.6% +/- 2.1% at
6 years. Multivariate analysis of the entire cohort revealed stem cell priming
with VP-16 (RR = 7.7, P = 0.002) to be independently associated with an increased
risk of t-MDS/t-AML. The influence of pretransplant therapy on subsequent t-MDS/t
AML risk was determined by a case-control study. Multivariate analysis revealed
an association between pretransplant radiation and the risk of t-MDS/t-AML, but
failed to reveal any association with pretransplant chemotherapy or conditioning
regimens. However, patients who had been primed with VP-16 for stem cell
mobilization were at a 12. 3-fold increased risk of developing t-AML with
11q23/21q22 abnormalities (P = 0.006). Patients undergoing HDT with stem cell
rescue are at an increased risk of t-MDS/t-AML, especially those receiving
priming with VP-16 for peripheral stem cell collection. (Blood. 2000;95:1588
1593)
PMID- 10688813
TI - Sustained expression of human factor VIII in mice using a parvovirus-based
vector.
AB - Persistent therapeutic levels of human factor VIII (hFVIII) would signify a major
advance in the treatment of hemophilia A. Here we report sustained expression of
hFVIII in immunocompetent mice using recombinant adeno-associated virus (rAAV)
vectors. AAV can stably transduce liver cells, the target tissue for efficient
hFVIII production. Because of rAAV packaging constraints, we tested 2 constructs
using small regulatory elements designed for liver-specific transgene expression
linked to B-domain-deleted hFVIII (BDD-hFVIII) cDNA. More than 10(12)/mL rAAV/BDD
hFVIII virion particles were generated using a transfection scheme that
eliminates adenovirus. Coatest and APTT assays confirmed the production of
functional BDD-hFVIII protein after transduction of 293 and HepG2 cells. In vivo
experiments were performed in C57BL/6 and NOD/scid mice receiving 10(10-11)
rAAV/hFVIII particles via portal vein injection. All C57BL/6 mice tested
developed anti-hFVIII antibody. In contrast, NOD/scid mice expressed hFVIII
reaching 27% of normal human plasma levels. As expected, we could not detect
hFVIII antigen from plasma samples isolated from control animals receiving
equivalent doses of rAAV expressing enhanced green fluorescent protein (EGFP).
Transgene mRNA expression was detected primarily in the liver and histologic
analysis of the liver revealed no pathologic abnormalities. These results
demonstrate a promising approach for treatment of hemophilia A. (Blood.
2000;95:1594-1599)
PMID- 10688814
TI - Interleukin 5 regulates the isoform expression of its own receptor alpha-subunit.
AB - The receptor for interleukin 5 (IL-5) consists of a cytokine-specific alpha chain
(IL-5Ralpha) and a signaling beta chain, which is shared with interleukin 3 (IL
3) and granulocyte-macrophage colony-stimulating factor (GM-CSF). These 3
cytokines can act in eosinophil development and activation in vitro, but gene
deletion or antibody blocking of IL-5 largely ablates eosinophilic responses in
models of allergic disease or helminth infection. We investigated factors acting
in differential IL-5Ralpha gene splicing to generate either the membrane-anchored
isoform (TM-IL-5Ralpha) which associates with the common beta chain to allow IL-5
responsiveness, or a secreted, antagonist variant (SOL-IL-5Ralpha). In a murine
myeloid cell line (FDC-P1), transfected with minigenes allowing expression of
either IL-5Ralpha variant, IL-5 itself, but not IL-3 or GM-CSF, stimulated a
reversible switch toward expression of TM-IL-5Ralpha. A switch from predominantly
soluble isoform to TM-IL-5Ralpha messenger RNA (mRNA) expression was also seen
during IL-5-driven eosinophil development from human umbilical cord blood-derived
CD34(+) cells; this was accompanied by surface expression of IL-5Ralpha and
acquisition of functional responses to IL-5. IL-3 and GM-CSF also supported
eosinophil development and up-regulation of TM-IL-5Ralpha mRNA in this system,
but this was preceded by expression of IL-5 mRNA and was inhibited by monoclonal
antibody to IL-5. These data suggest IL-5-specific signaling, not shared by IL-3
and GM-CSF, leading to a switch toward up-regulation of functional IL-5Ralpha
and, furthermore, that IL-3 and GM-CSF-driven eosinophil development is dependent
on IL-5, providing an explanation for the selective requirement of IL-5 for
expansion of the eosinophil lineage. (Blood. 2000;95:1600-1607)
PMID- 10688815
TI - Spatial associations of centromeres in the nuclei of hematopoietic cells:
evidence for cell-type-specific organizational patterns.
AB - It is believed that the 3-dimensional organization of centromeric heterochromatin
in interphase may be of functional relevance as an epigenetic mechanism for the
regulation of gene expression. Accordingly, a likely possibility is that the
centromeres that spatially associate into the heterochromatic structures
(chromocenters) observed in the G1 phase of the cell cycle will differ in
different cells. We sought to address this issue using, as a model, the
chromocenters observed in quiescent normal human hematopoietic cells and primary
fibroblasts. To do this, we analyzed the spatial relationships among different
human centromeres in 3-D preserved cells using nonisotopic in situ hybridization
and confocal microscopy. We showed quantitatively that chromocenters in all cell
types do indeed represent nonrandom spatial associations of certain centromeres.
Furthermore, the observed patterns of centromere association indicate that the
chromocenters in these cell types are made of different combinations of specific
centromeres, that hematopoietic cells are strikingly different from fibroblasts
as to the composition of their chromocenters and that centromeres in peripheral
blood cells appear to aggregate into distinct "myeloid" (present in monocytes and
granulocytes) and "lymphoid" (present in lymphocytes) spatial patterns. These
findings support the idea that the chromocenters formed in the nucleus of
quiescent hematopoietic cells might represent heterochromatic nuclear
compartments involved in the regulation of cell-type-specific gene expression,
further suggesting that the spatial arrangement of centromeric heterochromatin in
interphase is ontogenically determined during hematopoietic differentiation.
(Blood. 2000;95:1608-1615)
PMID- 10688816
TI - A soluble form of human Delta-like-1 inhibits differentiation of hematopoietic
progenitor cells.
AB - Two Notch ligand families, Delta and Serrate/Jagged, have been identified in
vertebrates. Members of the Jagged family have been shown to affect in vitro
hematopoiesis. To determine whether members of the Delta family might play a
similar role in hematopoiesis, we examined the expression of mouse Delta-like-1
(mDll1). mDll1 protein was detected in whole marrow and in a marrow stromal cell
line MS-5. At the RNA level, both mDll1 and Notch1 were seen in marrow precursor,
differentiated hematopoietic, marrow stromal, and MS-5 cells. We isolated a cDNA
encoding the human homologue of mDll1, designated human Delta-like-1 (hDll1). A
soluble form of hDll1, hDll1(NDSL), containing the DSL domain and the N-terminal
sequences, was expressed and purified from bacteria as a glutathione S
transferase (GST) fusion protein. We observed that hDll1(NDSL) delayed the
acquisition of differentiation markers by murine hematopoietic progenitor cells
(Lin-) cultured in vitro with cytokines. In addition, it promoted greater
expansion (more than 3 times) of the primitive hematopoietic precursor cell
population, measured in high-proliferative potential colony assay and day 12
colony-forming unit spleen (CFU-S) assay, than GST controls. We also observed
that the percentage of apoptotic cells decreased and that the number of cells in
the S-phase of the cell cycle increased in the cultures of Lin(-) cells with
hDll1(NDSL). The effects of hDll1(NDSL) were blocked by antibody against the
mouse counterpart of hDll1(NDSL), mDll1(NDSL). These observations demonstrate
that hDll1 plays a role in mediating cell fate decisions during hematopoiesis.
(Blood. 2000;95:1616-1625)
PMID- 10688817
TI - Regulation of Jak2 tyrosine kinase by protein kinase C during macrophage
differentiation of IL-3-dependent myeloid progenitor cells.
AB - Differentiation of macrophages from myeloid progenitor cells depends on a
discrete balance between cell growth, survival, and differentiation signals.
Interleukin-3 (IL-3) supports the growth and survival of myeloid progenitor cells
through the activation of Jak2 tyrosine kinase, and macrophage differentiation
has been shown to be regulated by protein kinase C (PKC). During terminal
differentiation of macrophages, the cells lose their mitogenic response to IL-3
and undergo growth arrest, but the underlying signaling mechanisms have remained
elusive. Here we show that in IL-3-dependent 32D myeloid progenitor cells, the
differentiation-inducing PKC isoforms PKC-alpha and PKC-delta specifically caused
rapid inhibition of IL-3-induced tyrosine phosphorylation. The target for this
inhibition was Jak2, and the activation of PKC by 12-O-tetradecanoyl-phorbol-13
acetate treatment also abrogated IL-3-induced tyrosine phosphorylation of Jak2 in
Ba/F3 cells. The mechanism of this regulation was investigated in 32D and COS7
cells, and the inhibition of Jak2 required catalytic activity of PKC-delta and
involved the phosphorylation of Jak2 on serine and threonine residues by the
associated PKC-delta. Furthermore, PKC-delta inhibited the in vitro catalytic
activity of Jak2, indicating that Jak2 was a direct target for PKC-delta. In 32D
cells, the inhibition of Jak2 either by PKC-delta, tyrosine kinase inhibitor
AG490, or IL-3 deprivation caused a similar growth arrest. Reversal of PKC-delta
mediated inhibition by the overexpression of Jak2 promoted apoptosis in
differentiating 32D cells. These results demonstrate a PKC-mediated negative
regulatory mechanism of cytokine signaling and Jak2, and they suggest that it
serves to integrate growth-promoting and differentiation signals during
macrophage differentiation. (Blood. 2000;95:1626-1632)
PMID- 10688818
TI - Existence of a differentiation blockage at the stage of a megakaryocyte precursor
in the thrombocytopenia and absent radii (TAR) syndrome.
AB - The thrombocytopenia and absent radii (TAR) syndrome is a rare disease
associating bilateral radial agenesis and congenital thrombocytopenia. Here, we
investigated in vitro megakaryocyte (MK) differentiation and expression of c-mpl
in 6 patients. Using blood or marrow CD34(+) cells, the colony-forming unit (CFU)
MK number was markedly reduced. CD34(+) cells were also cultured in liquid medium
in the presence of a combination of 3 cytokines (stem cell factor, interleukin-3,
and interleukin-6) or megakaryocyte growth and development factor (PEG-rHuMGDF)
with or without SCF. In the presence of PEG-rHuMGDF, the majority of mature
megakaryocytes (CD41 high, CD42 high) underwent apoptosis. This phenomenon was
also observed in cultures stimulated by three cytokines. However, this last
combination of cytokines allowed a more complete terminal MK differentiation.
Surprisingly, a homogeneous population of CD34(-)CD41(+)CD42(-) cells accumulated
during the cultures. This population was unable to differentiate along the
myeloid pathways. This result suggests that a fraction of MK cells is unable to
differentiate in the TAR syndrome. We subsequently investigated whether this
could be related to an abnormality in c-mpl. No mutation or rearrangement in the
c-mpl gene was found by Southern blots or by sequencing of the c-mpl coding
region and its promoter in any of the patients. Using Western blot analysis, a
decreased level of Mpl was found in patient platelets. A decreased level of c-mpl
messenger RNA in TAR platelets was also detected with a lower c-mpl-P to c-mpl-K
ratio in comparison to adult platelets. Altogether, these results demonstrate
that the thrombocytopenia of the TAR syndrome is associated with a
dysmegakaryocytopoiesis characterized by cells blocked at an early stage of
differentiation. (Blood. 2000;95:1633-1641)
PMID- 10688819
TI - Leishmania donovani infection of bone marrow stromal macrophages selectively
enhances myelopoiesis, by a mechanism involving GM-CSF and TNF-alpha.
AB - Alterations in hematopoiesis are common in experimental infectious disease.
However, few studies have addressed the mechanisms underlying changes in
hematopoietic function or assessed the direct impact of infectious agents on the
cells that regulate these processes. In experimental visceral leishmaniasis,
caused by infection with the protozoan parasite Leishmania donovani, parasites
persist in the spleen and bone marrow, and their expansion in these sites is
associated with increases in local hematopoietic activity. The results of this
study show that L donovani targets bone marrow stromal macrophages in vivo and
can infect and multiply in stromal cell lines of macrophage, but not other
lineages in vitro. Infection of stromal macrophages increases their capacity to
support myelopoiesis in vitro, an effect mediated mainly through the induction of
granulocyte macrophage-colony stimulating factor and tumor necrosis factor-alpha.
These data are the first to directly demonstrate that intracellular parasitism of
a stromal cell population may modify its capacity to regulate hematopoiesis
during infectious disease. (Blood. 2000;95:1642-1651)
PMID- 10688820
TI - The GATA-E box-GATA motif in the EKLF promoter is required for in vivo
expression.
AB - The erythroid Kruppel-like factor (EKLF) is a key regulatory protein in globin
gene expression. This zinc finger transcription factor is required for expression
of the adult beta globin gene, and it has been suggested that it plays an
important role in the developmental switch from fetal gamma to adult beta globin
gene expression. We have previously described a sequence element in the distal
promoter region of the mouse EKLF gene that is critical for the expression of
this transcription factor. The element consists of an E box motif flanked by 2
GATA-1 binding sites. Here we demonstrate that mutation of the E box or the GATA
1 consensus sequences eliminates expression from the EKLF promoter in transgenic
mice. These results confirm the importance of this activator element for in vivo
expression of the EKLF gene. (Blood. 2000;95:1652-1655)
PMID- 10688821
TI - Activation of Akt kinase by granulocyte colony-stimulating factor (G-CSF):
evidence for the role of a tyrosine kinase activity distinct from the Janus
kinases.
AB - Activation of the serine/threonine kinase Akt has been shown to be a critical
component for growth factor and cytokine stimulation of cell survival. Although
some of the immediate upstream activators of Akt have been defined, the roles of
tyrosine kinases in the activation of Akt are not well delineated. Granulocyte
colony-stimulating factor (G-CSF) regulates the proliferation, differentiation,
and survival of neutrophilic granulocytes. G-CSF exerts its actions by
stimulating several signaling cascades after binding its cell surface receptor.
Both Jak (Janus) and Src families of tyrosine kinases are stimulated by
incubation of cells with G-CSF. In this report, we show that G-CSF stimulation of
cells leads to activation of Akt. The membrane-proximal 55 amino acids of the G
CSF receptor cytoplasmic domain are sufficient for mediating Akt activation.
However, activation of Akt appears to be downregulated by the receptor's carboxy
terminal region of 98 amino acids, a region that has been shown to be truncated
in some patients with acute myeloid leukemia associated with severe congenital
neutropenia. Furthermore, we demonstrate that G-CSF-induced activation of Akt
requires the activities of Src family kinases but can be clearly dissociated from
G-CSF-stimulated activation of Stats (signal transducers and activators of
transcription) by the Jak kinases. Thus, cytokine activation of the Jak/Stat and
other signaling cascades can be functionally separated. (Blood. 2000;95:1656
1662)
PMID- 10688822
TI - Rapid tyrosine phosphorylation and activation of Bruton's tyrosine/Tec kinases in
platelets induced by collagen binding or CD32 cross-linking.
AB - Stimulation of the platelet nonintegrin collagen receptor, glycoprotein VI,
evokes a signaling response similar to that induced by antigen receptor
activation in B and T lymphocytes. A key transducer of the lymphocyte signaling
pathways is the Bruton's tyrosine kinase (Btk)/Tec kinase family, which connects
receptors to the elevation of intracellular-free calcium levels. An important
signaling function for Btk in collagen-induced platelet activation in vitro was
recently demonstrated by other researchers using Btk-deficient platelets from
patients with X-linked agammaglobulinemia (XLA). Since Btk-deficiency does not
induce an overt platelet-based bleeding disorder in vivo, collagen receptor
responses may include other Btk/Tec kinase family members in normal platelets.
Both Btk and Tec had increased tyrosine following stimulation of collagen
receptors or CD32 cross-linking. Data from kinetic analyses and inhibitor studies
and the use of phosphopeptide-specific antibodies recognizing 2 Btk regulatory
phosphorylated tyrosine residues suggest a mechanism for coordinate recruitment
of Btk and Tec through the immunoreceptor tyrosine-based activation motif, Src
family kinases, and phosphatidylinositol 3-kinase. In XLA platelets, collagen
treatment increased tyrosine phosphorylation of Tec and several other signaling
proteins, including Lyn, Fyb, Slp-76, and the Wiskott-Aldrich syndrome protein.
This indicates that important elements of the collagen signaling pathway proximal
and distal to Btk and Tec are preserved despite the lack of functional Btk. The
results are consistent with the conclusion that activation of Tec may sustain XLA
platelet function in vivo, while some in vitro assays of nonintegrin collagen
receptor signaling through the Btk/Tec kinase family reflect the additive dosage
of the transducers. (Blood. 2000;95:1663-1670)
PMID- 10688823
TI - Vasculogenesis in the day 6.5 to 9.5 mouse embryo.
AB - The process of vasculogenesis was characterized in the 6.5- to 9.5-day mouse
embryo and in allantoic culture by analysis of spatial and temporal expression
patterns of the endothelial or hematopoietic lineage-associated proteins, TAL1,
Flk1, platelet/endothelial cell adhesion molecule (PECAM), CD34, VE-cadherin, and
Tie2. The study establishes that: (1) TAL1 and Flk1 are coexpressed in isolated
mesodermal cells that give rise to endothelial cells and thus can be defined as
angioblasts; (2) hematopoietic cells of blood islands express TAL1, but not Flk1;
(3) vasculogenesis in the embryo proper is initiated by mesoderm fated to give
rise to the endocardium; (4) the maturation/morphogenesis of blood vessels can be
defined in terms of a sequential pattern of expression in which TAL1 and Flk1 are
expressed first followed by PECAM, CD34, VE-cadherin, and later Tie2; and (5)
TAL1 expression is down-regulated in endothelial cells of mature vessels. (Blood.
2000;95:1671-1679)
PMID- 10688824
TI - The endothelial cell protein C receptor aids in host defense against Escherichia
coli sepsis.
AB - The influence of the endothelial protein C receptor (EPCR) on the host response
to Escherichia coli was studied. Animals were treated with 4 separate protocols
for survival studies and analysis of physiologic and biochemical parameters: (1)
monoclonal antibody (mAb) that blocks protein C/activated protein C binding to
EPCR plus sublethal numbers of E coli (SLEC) (n = 4); (2) mAb to EPCR that does
not block binding plus SLEC (n = 3); (3) SLEC alone (n = 4); and (4) blocking mAB
alone (n = 1). Those animals receiving blocking mAb to EPCR plus sublethal E coli
died 7 to 54 hours after challenge, whereas all animals treated with the other
protocols were permanent survivors. Histopathologic studies of tissues from
animals receiving blocking mAb plus SLEC removed at postmortem were compared with
those animals receiving SLEC alone killed at T+24 hours. The animals receiving
the blocking mAb exhibited consumption of fibrinogen, microvascular thrombosis
with hemorrhage of both the adrenal and renal cortex, and an intense influx of
neutrophils into the adrenal, renal, and hepatic microvasculature, whereas the
tissues from animals receiving only sublethal E coli exhibited none of these
abnormal histopathologic changes. Compared with the control animals, the animals
receiving the blocking mAb exhibited significantly elevated serum glutamic
pyruvic transaminase, anion gap, thrombin-antithrombin complex, IL-6, IL-8, and
soluble thrombomodulin. The levels of circulating activated protein C varied too
widely to allow a clear determination of whether the extent of protein C
activation was altered in vivo by blocking protein C binding to EPCR. We conclude
that protein C/activated protein C binding to EPCR contributes to the negative
regulation of the coagulopathic and inflammatory response to E coli and that EPCR
provides an additional critical step in the host defense against E coli. (Blood.
2000;95:1680-1686)
PMID- 10688825
TI - Endotoxin and thrombin elevate rodent endothelial cell protein C receptor mRNA
levels and increase receptor shedding in vivo.
AB - The endothelial cell protein C receptor (EPCR) facilitates protein C activation
by the thrombin-thrombomodulin complex. Protein C activation has been shown to be
critical to the host defense against septic shock. In cell culture, tumor
necrosis factor-alpha (TNF-alpha) down-regulates EPCR expression, raising the
possibility that EPCR might be down-regulated in septic shock. We examined EPCR
mRNA and soluble EPCR levels in mice and rats challenged with lethal dose 95
levels of endotoxin. Toxic doses of TNF-alpha failed to alter EPCR mRNA levels in
mice. Rather than EPCR mRNA levels falling in response to endotoxin, as predicted
from cell-culture experiments, they rose approximately 3-fold 6 hours after
exposure to endotoxin before returning toward baseline levels at 24 hours after
exposure. Soluble EPCR levels rose approximately 4-fold. Infusion of hirudin, a
specific thrombin inhibitor, before endotoxin exposure almost completely blocked
the increase in EPCR mRNA and soluble EPCR. Consistent with the idea that the
responses were mediated by thrombin, thrombin infusion (5 U/kg of body weight for
3 hours) resulted in an approximately 2-fold increase in EPCR mRNA and soluble
EPCR. Incubation of rat endothelial cells with thrombin or murine protease
activated receptor 1 agonist peptide resulted in a 2-fold increase in EPCR mRNA.
These results indicate that thrombin plays a major role in up-regulating EPCR
mRNA and shedding in vivo. (Blood. 2000;95:1687-1693)
PMID- 10688826
TI - Surface expression and functional characterization of alpha-granule factor V in
human platelets: effects of ionophore A23187, thrombin, collagen, and convulxin.
AB - Factor V (FV) present in platelet alpha-granules has a significant but
incompletely understood role in hemostasis. This report demonstrates that a
fraction of platelets express very high levels of surface-bound, alpha-granule FV
on simultaneous activation with 2 agonists, thrombin and convulxin, an activator
of the collagen receptor glycoprotein VI. This subpopulation of activated
platelets represents 30.7% +/- 4.7% of the total population and is referred to as
convulxin and thrombin-induced-FV (COAT-FV) platelets. COAT-FV platelets are also
observed on activation with thrombin plus collagen types I, V, or VI, but not
with type III. No single agonist examined was able to produce COAT-FV platelets,
although ionophore A23187 in conjunction with either thrombin or convulxin did
generate this population. COAT-FV platelets bound annexin-V, indicating exposure
of aminophospholipids and were enriched in young platelets as identified by the
binding of thiazole orange. The functional significance of COAT-FV platelets was
investigated by demonstrating that factor Xa preferentially bound to COAT-FV
platelets, that COAT-FV platelets had more FV activity than either thrombin or
A23187-activated platelets, and that COAT-FV platelets were capable of generating
more prothrombinase activity than any other physiologic agonist examined.
Microparticle production by dual stimulation with thrombin and convulxin was less
than that observed with A23187, indicating that microparticles were not
responsible for all the activities observed. These data demonstrate a new
procoagulant component produced from dual stimulation of platelets with thrombin
and collagen. COAT-FV platelets may explain the unique role of alpha-granule FV
and the hemostatic effectiveness of young platelets. (Blood. 2000;95:1694-1702)
PMID- 10688827
TI - Involvement of low-density lipoprotein receptor-related protein (LRP) in the
clearance of factor VIII in von Willebrand factor-deficient mice.
AB - Factor VIII is tightly noncovalently linked to von Willebrand factor (vWF) in
plasma with a stoichiometry of 1:50, and vWF deficiency results in secondary
factor VIII deficiency, with accelerated clearance of factor VIII from the
circulation. We used a murine model of severe von Willebrand disease (vWF
knockout mice) to study the effect of a recombinant vWF/pro-vWF preparation
(rpvWF) on factor VIII survival and to investigate whether low-density
lipoprotein receptor-related protein (LRP) might be involved in the in vivo
clearance of factor VIII in the absence of vWF. vWF-deficient mice received 70
U/kg rpvWF in the first series of experiments, and in a second series, 80 mg/kg
receptor-associated protein (RAP) as a recombinant fusion protein to block the
action of LRP. Factor VIII levels were measured at time 0, or 1 or 3 hours after
administration of rpvWF or RAP. RAP induced a sustained rise in factor VIII
levels comparable to that induced by rpvWF. In a third series, the
preadministration of RAP resulted in a slower disappearance of factor VIII
antigen (measured by an enzyme-linked immunosorbent assay specific for human
factor VIII) after infusion of recombinant factor VIII. These findings suggest
that the accelerated clearance of factor VIII seen in the absence of vWF may be a
result of the involvement of LRP in factor VIII metabolism. (Blood. 2000;95:1703
1708)
PMID- 10688828
TI - Hypofibrinogenemia in an individual with 2 coding (gamma82 A-->G and Bbeta235 P-
>L) and 2 noncoding mutations.
AB - We investigated the molecular basis of hypofibrinogenemia in a man with a normal
thrombin clotting time. Protein analysis indicated equal plasma expression of 2
different Bbeta alleles, and DNA sequencing confirmed heterozygosity for a new
Bbeta235 P-->L mutation. Protein analysis also revealed a novel gamma(D) chain,
present at a ratio of 1:2 relative to the gamma(A) chain. Mass spectrometry
indicated a 14 d decrease in the gamma(D)-chain mass, and DNA sequencing showed
this was caused by a novel gamma82 A-->G substitution. DNA sequencing established
heterozygosity for 2 further mutations: T-->C in intron 4 of the Aalpha gene and
A-->C in the 3' noncoding region of the Bbeta gene. Studies on the man's
daughter, together with plasma expression levels, discounted both the Aalpha and
Bbeta mutations as the cause of the low fibrinogen, suggesting that the gamma82
mutation caused the hypofibrinogenemia. This was supported by analysis of 31
normal controls in whom the Bbeta mutations were found at polymorphic levels,
with an allelic frequency of 5% for the Bbeta235 mutation and 42% for the Bbeta
3' untranslated mutation. The gamma82 mutation was, however, unique to the
propositus. Residue gamma82 is located in the triple helix that separates the E
and D domains, and aberrant packing of the helices may explain the decreased
fibrinogen concentration. (Blood. 2000;95:1709-1713)
PMID- 10688829
TI - Regulation of factor VIIIa by human activated protein C and protein S:
inactivation of cofactor in the intrinsic factor Xase.
AB - Factor VIIIa is a trimer of A1, A2, and A3-C1-C2 subunits. Inactivation of the
cofactor by human activated protein C (APC) results from preferential cleavage at
Arg336 within the A1 subunit, followed by cleavage at Arg562 bisecting the A2
subunit. In the presence of human protein S, the rate of APC-dependent factor
VIIIa inactivation increased several-fold and correlated with an increased rate
of cleavage at Arg562. (Active site-modified) factor IXa, blocked cleavage at the
A2 site. However, APC-catalyzed inactivation of factor VIIIa proceeded at a
similar rate independent of factor IXa, consistent with the location of the
preferential cleavage site within the A1 subunit. Addition of protein S failed to
increase the rate of cleavage at the A2 site when factor IXa was present. In the
presence of factor X, cofactor inactivation was inhibited, due to a reduced rate
of cleavage at Arg336. However, inclusion of protein S restored near original
rates of factor VIIIa inactivation and cleavage at the A1 site, thus overcoming
the factor X-dependent protective effect. These results suggest that in the human
system, protein S stimulates APC-catalyzed factor VIIIa inactivation by
facilitating cleavage of A2 subunit (an effect retarded in the presence of factor
IXa), as well as abrogating protective interactions of the cofactor with factor
X. (Blood. 2000;95:1714-1720)
PMID- 10688830
TI - A monoclonal antibody specific to the granulocyte-derived elastase-fragment D
species of human fibrinogen and fibrin: its application to the measurement of
granulocyte-derived elastase digests in plasma.
AB - When granulocytes are stimulated under certain clinical conditions, elastase is
released therefrom and digests fibrin(ogen) independently of the plasmin system,
which may also be mobilized simultaneously. Thus, discrimination of these 2
systems becomes urgent for the diagnosis and treatment of the underlying
diseases. Using as immunogen a 97-kd granulocyte-elastase digest of human
fibrinogen, we raised an antibody IF-123 that specifically recognizes elastase
digests of human fibrin(ogen). The 97-kd elastase fragment resembles plasmic
fragment D(1), and the epitope of this antibody is located on the Aalpha (196
204) residue segment. This segment appears to be masked in fibrin(ogen) but
exposed when the Aalpha Leu 204-Ile 205 peptide bond is cleaved by elastase.
Cathepsin G concomitantly released from granulocytes failed to expose the
epitope. By an enzyme immunoassay using IF-123 as the capture antibody, the
elastase digests of fibrin(ogen) can be measured in plasma samples without
interference by abundantly coexisting fibrinogen. Indeed, we found that the
elastase digests were mostly elevated in patients with inflammation or malignant
tumors, but remained in a normal range in patients with a benign gastrointestinal
tract disease such as duodenal ulcer and polyps in the gallbladder or the colon.
Like the plasmic D-dimer, the elastase digests predominantly consisted of the
DD/E complex and DD/E-containing high-molecular weight derivatives apparently
corresponding to the phase-3 plasmic digests of cross-linked fibrin. (Blood.
2000;95:1721-1728)
PMID- 10688831
TI - Lepirudin blunts endotoxin-induced coagulation activation.
AB - During sepsis, lipopolysaccharide (LPS) triggers the development of disseminated
intravascular coagulation (DIC) via the tissue factor-dependent pathway of
coagulation resulting in massive thrombin generation and fibrin polymerization.
Recently, animal studies demonstrated that hirudin reduced fibrin deposition in
liver and kidney and decreased mortality in LPS-induced DIC. Accordingly, the
effects of recombinant hirudin (lepirudin) was compared with those caused by
placebo on LPS-induced coagulation in humans. Twenty-four healthy male subjects
participated in this randomized, double-blind, placebo-controlled, parallel group
study. Volunteers received 2 ng/kg LPS intravenously, followed by a bolus-primed
continuous infusion of placebo or lepirudin (Refludan, bolus: 0.1 mg/kg,
infusion: 0.1 mg/kg/h for 5 hours) to achieve a 2-fold prolongation of the
activated partial thromboplastin time (aPTT). LPS infusion enhanced thrombin
activity as evidenced by a 20-fold increase of thrombin-antithrombin complexes
(TAT), a 6-fold increase of polymerized soluble fibrin, termed thrombus precursor
protein (TpP), and a 4-fold increase in D-dimer. In the lepirudin group, TAT
increased only 5-fold, TpP increased by only 50%, and D-dimer only slightly
exceeded baseline values (P <.01 versus placebo). Concomitantly, lepirudin also
blunted thrombin generation evidenced by an attenuated rise in prothrombin
fragment levels (F(1 + 2), P <. 01 versus placebo) and blunted the expression of
tissue factor on circulating monocytes. This experimental model proved the
anticoagulatory potency of lepirudin in LPS-induced coagulation activation.
Results from this trial provide a rationale for a randomized clinical trial on
the efficacy of lepirudin in DIC. (Blood. 2000;95:1729-1734)
PMID- 10688832
TI - Unique processing pathways within recipient antigen-presenting cells determine
IgG immunity against donor platelet MHC antigens.
AB - Recipient IgG immunity against leukoreduced donor platelets is dependent on
indirect T-cell allorecognition and is suppressed in vivo by inhibitors
(aminoguanidine, AMG) of inducible nitric oxide synthase (iNOS). To examine
recipient processing pathways of donor platelet antigens, enriched macrophages
(antigen-presenting cells [APC]) from BALB/c (H-2(d)) mice were pulsed with
allogeneic C57BL/6 (H-2(b)) platelets and transfused weekly into naive BALB/c
mice. Platelet-pulsed APC stimulated IgG antidonor antibody production in 45% of
recipients by the second transfusion and in 100% by the sixth transfusion; this
response was enhanced by pulsing in the presence of interferon-gamma. By the
sixth transfusion, high-titer IgG1 (mean titer 4990) and IgG2a (1933) isotypes
specific for donor major histocompatibility complex (MHC) class I antigens were
detected. Platelet pulsing in the presence of AMG or colchicine significantly
inhibited the ability of APC to stimulate IgG alloantibodies; only 50% (P <.005)
and 20% (P <.0001) of recipients, respectively, produced antibodies by the sixth
transfusion. AMG inhibition was reversed by the addition of L-arginine, the
substrate for iNOS. In contrast, pulsing in the presence of chloroquine, the
proteasome inhibitory peptide MG115, or Brefeldin A enhanced APC immunity (70
100% of recipients antibody positive by the second transfusion [P <.05]); these
agents allowed the pulsed APC to stimulate IgG2a but inhibited IgG1 production
and this correlated with a reduction in serum interleukin (IL)-4 levels. The
results suggest that for donor platelet antigens to stimulate IgG alloantibodies,
recipient APC use the essential generation of nitric oxide and a noncytosolic, pH
independent processing pathway, which can be exploited as an effective
immunotherapy target to further inhibit alloimmunization against leukoreduced
platelets. (Blood. 2000;95:1735-1742)
PMID- 10688833
TI - Initiation of antiretroviral therapy during primary HIV-1 infection induces rapid
stabilization of the T-cell receptor beta chain repertoire and reduces the level
of T-cell oligoclonality.
AB - Major T-cell receptor beta chain variable region (TCRBV) repertoire perturbations
are temporally associated with the down-regulation of viremia during primary
human immunodeficiency virus (HIV) infection and with oligoclonal expansion and
clonal exhaustion of HIV-specific cytotoxic T lymphocytes (CTLs). To determine
whether initiation of antiretroviral therapy (ART) or highly active
antiretroviral therapy (HAART) during primary infection influences the dynamics
of T-cell-mediated immune responses, the TCRBV repertoire was analyzed by
semiquantitative polymerase chain reaction in serial blood samples obtained from
11 untreated and 11 ART-treated patients. Repertoire variations were evaluated
longitudinally. Stabilization of the TCRBV repertoire was more consistently
observed in treated as compared with untreated patients. Furthermore, the extent
and the rapidity of stabilization were significantly different in treated versus
untreated patients. TCRBV repertoire stabilization was positively correlated with
the slope of HIV viremia in the treated group, suggesting an association between
repertoire stabilization and virologic response to treatment. To test whether
stabilization was associated with variations in the clonal complexity of T-cell
populations, T-cell receptor (TCR) heteroduplex mobility shift assays (HMAs) were
performed on sequential samples from 4 HAART-treated subjects. Densitometric
analysis of HMA profiles showed a reduction in the number of TCR clonotypes in
most TCRBV families and a significant decrease in the total number of clonotypes
following 7 months of HAART. Furthermore, a biphasic decline in HIV-specific but
not heterologous CTL clones was observed. This indicates that ART leads to a
global reduction of CD8(+) T-cell oligoclonality and significantly modulates the
mobilization of HIV-specific CTL during primary infection. (Blood. 2000;95:1743
1751)
PMID- 10688834
TI - Inhibition of degranulation and interleukin-6 production in mast cells derived
from mice deficient in protein kinase Cbeta.
AB - The antigen-mediated activation of mast cells by means of IgE antibodies bound to
the cell surface leads to direct interactions between FcepsilonRI receptor
cytoplasmic domains and various intracellular proteins. These interactions
initiate diverse signal-transduction pathways, and the activation of these
pathways results in the immediate release of proinflammatory agents. A delayed
response also occurs and includes the release of various cytokines. It is clear
that the activation of kinases is a requirement for the exocytosis observed in
mast cells. In addition to the tyrosine phosphorylation of the affected system by
soluble tyrosine kinases, activity of protein kinase C (PKC) results in serine or
threonine phosphorylation of multiple protein substrates. In this study, we found
that mast cells derived from PKCbeta-deficient mice produce less interleukin 6 in
response to IgE-Ag. The inhibition of exocytosis in the PKCbeta-deficient mast
cells occurred whether the stimuli were due to the aggregation of the mast cell
surface FcepsilonRI or to the calcium ionophore, ionomycin. However, no
significant changes were observed in the proliferative response of the mast cells
to interleukin 3 (IL-3) or in their apoptotic rate after IL-3 depletion. (Blood.
2000;95:1752-1757)
PMID- 10688835
TI - Induction of resistance to the Abelson inhibitor STI571 in human leukemic cells
through gene amplification.
AB - The 2-phenylaminopyrimidine derivative STI571 has been shown to selectively
inhibit the tyrosine kinase domain of the oncogenic bcr/abl fusion protein. The
activity of this inhibitor has been demonstrated so far both in vitro with
bcr/abl expressing cells derived from leukemic patients, and in vivo on nude mice
inoculated with bcr/abl positive cells. Yet, no information is available on
whether leukemic cells can develop resistance to bcr/abl inhibition. The human
bcr/abl expressing cell line LAMA84 was cultured with increasing concentrations
of STI571. After approximately 6 months of culture, a new cell line was obtained
and named LAMA84R. This newly selected cell line showed an IC50 for the STI571
(1.0 microM) 10-fold higher than the IC50 (0.1 microM) of the parental sensitive
cell line. Treatment with STI571 was shown to increase both the early and late
apoptotic fraction in LAMA84 but not in LAMA84R. The induction of apoptosis in
LAMA84 was associated with the activation of caspase 3-like activity, which did
not develop in the resistant LAMA84R cell line. LAMA84R cells showed increased
levels of bcr/abl protein and mRNA when compared to LAMA84 cells. FISH analysis
with BCR- and ABL-specific probes in LAMA84R cells revealed the presence of a
marker chromosome containing approximately 13 to 14 copies of the BCR/ABL gene.
Thus, overexpression of the Bcr/Abl protein mediated through gene amplification
is associated with and probably determines resistance of human leukemic cells to
STI571 in vitro. (Blood. 2000;95:1758-1766)
PMID- 10688836
TI - MSH2-deficient murine lymphomas harbor insertion/deletion mutations in the
transforming growth factor beta receptor type 2 gene and display low not high
frequency microsatellite instability.
AB - High-frequency microsatellite instability (MSI), defined as more than 20%
unstable loci, is an inconsistent finding in hematologic malignancies;
consequently, the significance of deficient DNA mismatch repair (MMR) to their
pathogenesis has been questioned. To further investigate the relationship between
MMR deficiency and genomic instability in hematologic malignancies, this study
evaluated MSH2-/- murine lymphomas for insertion/deletion (ID) mutations within
the transforming growth factor (TGF)-beta receptor type II (TbetaR-II) gene and
MSI at 10 neutral microsatellites. The lymphomas displayed ID mutations within
short mononucleotide runs of TbetaR-II at a high frequency, whereas nonmalignant
tissue from corresponding animals lacked mutations. Loss of TbetaR-II transcripts
and protein was seen in 6 of 7 murine lymphomas harboring acquired TbetaR-II
mutations. In the analysis of paired nonmalignant and tumor DNA samples, low
frequency but not high-frequency MSI was found. Low-frequency MSI occurred in 8
of 20 lymphomas and 12 displayed microsatellite stability. MSI was even less
frequent in nonmalignant tissue as only 3 of 20 samples displayed low-frequency
MSI and 17 displayed stability. Evaluation of 20 single cell clones from the MSH2
/- lymphoma cell lines R25 and L15 identified high-frequency MSI in 4 and 2
clones, respectively. The remaining clones showed low-frequency MSI or stability.
These findings suggest that acquired TbetaR-II mutations represent important
inactivating events in tumor pathogenesis following MSH2 deficiency. Furthermore,
for some hematolymphoid malignancies, the evaluation of cancer-associated genes
for ID mutations may represent a more sensitive marker of MMR deficiency than
evaluation of neutral microsatellites for high-frequency MSI. (Blood.
2000;95:1767-1772)
PMID- 10688837
TI - Induction of mitochondrial permeability transition and cytochrome C release in
the absence of caspase activation is insufficient for effective apoptosis in
human leukemia cells.
AB - Induction of mitochondrial permeability transition (MPT) and cytosolic
translocation of cytochrome C are considered essential components of the
apoptotic pathway. Hence, there is the realization that mitochondrial-specific
drugs could have potential for use as chemotherapeutic agents to trigger
apoptosis in tumor cells. Recently, we showed that photoproducts of merocyanine
540 (pMC540) induced tumor cell apoptosis. In this study, we focused on
identifying mitochondrial-specific compounds from pMC540 and studied their
apoptotic potential. One purified fraction, C5, induced a drop in mitochondrial
transmembrane potential and cytosolic translocation of cytochrome C in HL60 human
leukemia cells. Moreover, the addition of C5 to purified rat liver mitochondria
induced MPT as indicated by mitochondrial matrix swelling, which was completely
inhibited by cyclosporin A, an inhibitor of the inner-membrane pore. Supernatant
of C5-treated mitochondria showed a dose-dependent increase in cytochrome C,
which was also inhibited in the presence of cyclosporin A, strongly indicating a
direct effect on the inner-membrane pore. Despite the strong mitochondrial
reactivity, C5 elicited minimal cytotoxicity (less than 25%) against HL60
leukemia and M14 melanoma cells because of inefficient caspase activation.
However, prior exposure to C5 significantly enhanced the apoptotic response to
etoposide or the CD95 receptor. Thus, we demonstrate that MPT induction and
cytochrome C release by the novel compound C5, in the absence of effective
caspase activation, is insufficient for triggering efficient apoptosis in tumor
cells. However, when used in combination with known apoptosis inducers, such
compounds could enhance the sensitivity of tumor cells to apoptosis. (Blood.
2000;95:1773-1780)
PMID- 10688838
TI - Vaccination of patients with chronic myelogenous leukemia with bcr-abl oncogene
breakpoint fusion peptides generates specific immune responses.
AB - Chronic myelogenous leukemia (CML) presents a unique opportunity to develop
therapeutic strategies using vaccination against a truly tumor-specific antigen
that is also the oncogenic protein required for neoplasia. CML is characterized
by the t(9;22) that results in the bcr-abl fusion oncogene and in the expression
of a chimeric protein product p210. Previously we have shown that peptides
derived from amino acid sequences crossing the b3a2 fusion breakpoint in p210
elicit class I restricted cytotoxic T lymphocytes and class II responses,
respectively, in vitro. Such sequences may thus comprise absolutely tumor
specific antigens in a peptide-based vaccine. We evaluated the safety and
immunogenicity of a multidose, bcr-abl breakpoint peptide vaccine in 12 adults
with chronic-phase CML. Cohorts of 3 patients each received either 50 microg, 150
microg, 500 microg, or 1500 microg total peptide mixed with 100 microg QS-21 as
an immunological adjuvant. Delayed-type hypersensitivity (DTH), humoral
responses, and unprimed ex vivo autologous proliferation ((3)H-thymidine
incorporation) and cytotoxicity (chromium-51 release) responses were measured.
All 68 vaccinations were well tolerated without significant adverse effects. In 3
of the 6 patients treated at the 2 highest dose levels of vaccine, peptide
specific, T-cell proliferative responses (n = 3) and/or DTH responses (n = 2)
were generated that lasted up to 5 months after vaccination. Cytotoxic T
lymphocytes have not been identified. In conclusion, a tumor-specific, bcr-abl
derived peptide vaccine can be safely administered to patients with chronic-phase
CML and can elicit a bcr-abl peptide-specific immune response despite the
presence of active disease in these patients and approximately 10(12) leukemia
cells. (Blood. 2000;95:1781-1787)
PMID- 10688839
TI - FGFR1 is fused to the centrosome-associated protein CEP110 in the 8p12 stem cell
myeloproliferative disorder with t(8;9)(p12;q33).
AB - The hallmark of the 8p12 stem cell myeloproliferative disorder (MPD) is the
disruption of the FGFR1 gene, which encodes a tyrosine kinase receptor for
members of the fibroblast growth factor family. FGFR1 can be fused to at least 3
partner genes at chromosomal regions 6q27, 9q33, or 13q12. We report here the
cloning of the t(8;9)(p12;q33) and the detection of a novel fusion betweenFGFR1
and the CEP110 gene, which codes for a novel centrosome-associated protein with a
unique cell-cycle distribution. CEP110 is widely expressed at various levels in
different tissues and is predicted to encode a 994-amino acid coiled-coil protein
with 4 consensus leucine zippers [L-X(6)-L-X(6)-L-X(6)-L]. Both reciprocal fusion
transcripts are expressed in the patient's cells. The CEP110-FGFR1 fusion protein
encodes an aberrant tyrosine kinase of circa 150-kd, which retains most of CEP110
with the leucine zipper motifs and the catalytic domain of FGFR1. Transient
expression studies show that the CEP110-FGFR1 protein has a constitutive kinase
activity and is located within the cell cytoplasm. (Blood. 2000;95:1788-1796)
PMID- 10688840
TI - Molecular analysis of immunoglobulin genes in diffuse large B-cell lymphomas.
AB - Diffuse large B-cell lymphoma (DLBCL) is a common type of non-Hodgkin's lymphoma
(NHL) that is highly heterogeneous from both clinical and histopathologic
viewpoints. The immunoglobulin (Ig) heavy (H) chain variable region genes were
examined in 71 patients with untreated primary DLBCL. Fifty-eight potentially
functional V(H) genes were detected in 53 DLBCL cases; V(H) genes were
nonfunctional in 9 cases and were not detected in an additional 9 cases. The use
of V(H) gene families by DLBCL tumors was unbiased without overrepresentation of
any particular V(H) gene or gene family. Analysis of Ig mutations in comparison
to the most closely related germline gene disclosed mutated V(H) genes in all but
1 DLBCL case. More than 2% difference from the most similar germline sequence was
detected in 52 potentially functional and the 8 nonfunctional V(H) gene
sequences, whereas less than 2% difference from the germline sequence was
observed in 3 V(H) gene isolates. Only 3 V(H) gene isolates were unmutated. No
correlation was found between V(H) gene use, mutation level, and International
Prognostic Index (IPI) or survival. Six of 8 tested tumors showed evidence of
ongoing somatic mutations. Evidence for positive or negative antigen selection
pressure was observed in 65% of mutated DLBCL cases. Our findings indicate that
the etiology and the driving forces for clonal expansion are heterogeneous, which
may explain the well-known clinical and pathologic heterogeneity of DLBCL.
(Blood. 2000;95:1797-1803)
PMID- 10688841
TI - Integrin alpha(2)beta(1) (VLA-2) is a principal receptor used by neutrophils for
locomotion in extravascular tissue.
AB - Cell adhesion molecules are critically involved in the multistep process of
leukocyte recruitment in inflammation. The specific receptors used by
polymorphonuclear leukocytes (PMN) for locomotion in extravascular tissue have as
yet not been identified. By means of immunofluorescence flow cytometry and laser
scanning confocal microscopy, this study demonstrated that surface expression of
the alpha(2)beta(1) (VLA-2) integrin, though absent on blood PMN, is induced in
extravasated PMN collected from human skin blister chambers, and rat PMN
accumulated in the peritoneal cavity after chemotactic stimulation. Intravital
time-lapse videomicroscopy was used to investigate chemoattractant-induced PMN
locomotion in the rat mesentery in vivo. Local administration of function
blocking monoclonal antibody or peptide recognizing the alpha(2)beta(1) integrin
reduced PMN migration velocity in the extravascular tissue by 73% +/- 3% and 70%
+/- 10%, respectively (means +/- SD). The distance f-met-leu-phe peptide (fMLP)
stimulated human PMN migrated in a collagen gel in vitro was markedly reduced by
treatment with anti-alpha(2) mAbs or peptide, whereas no effect was observed with
antibodies or peptides recognizing the alpha(4)beta(1) or alpha(5)beta(1)
integrins. Further evidence for a critical role of expression of alpha(2)beta(1)
integrin in PMN locomotion in extravascular tissue was obtained in the mouse air
pouch model of acute inflammation where chemoattractant-induced PMN recruitment
was substantially inhibited by local anti-alpha(2) mAb treatment. Thus,
expression of alpha(2)beta(1) integrin on extravasated PMN has been identified
and a novel role of this receptor in regulating the extravascular phase of
leukocyte trafficking in inflammation has been formulated. (Blood. 2000;95:1804
1809)
PMID- 10688842
TI - The synthetic chemoattractant Trp-Lys-Tyr-Met-Val-DMet activates neutrophils
preferentially through the lipoxin A(4) receptor.
AB - A D-methionine-containing peptide, Trp-Lys-Tyr-Met-Val-D-Met-NH(2) (WKYMVm),
featuring a unique receptor specificity was investigated with respect to its
ability to activate neutrophil effector functions. The peptide was found to be
more potent than the N-formylated peptide N-formyl-Met-Leu-Phe (fMLF) at inducing
neutrophil chemotaxis, mobilization of neutrophil complement receptor 3 (CR3),
and activation of the neutrophil NADPH-oxidase. The fact that binding of
fML[(3)H]F was inhibited by both fMLF and WKYMVm suggests that N-formyl peptide
receptor (FPR) is shared by these peptides. However, the neutrophil response
induced by the WKYMVm peptide was insensitive to the fMLF antagonists,
cyclosporin H, and Boc-FLFLF that specifically block the function of the FPR.
These results suggest that even though WKYMVm may bind FPR the cells are
activated preferentially through a receptor distinct from the FPR. Using
transfected HL-60 cells expressing either the FPR or its neutrophil homologue
FPRL1, also referred to as LXA(4)R because it has been shown to bind lipoxin
A(4), we show that WKYMVm is about 300-fold more active at mobilizing
intracellular calcium through FPRL1 than through FPR. The WKYMVm activates FPRL1
expressing cells in a cyclosporin H-independent manner with an EC(50 )of around
75 pmol/L, whereas it activates FPR-expressing cells with an EC(50 )of around 25
nmol/L. The observation that exudated cells are primed in their response to
WKYMVm suggests that FPRL1/LXA(4)R like FPR is stored in mobilizable organelles.
(Blood. 2000;95:1810-1818)
PMID- 10688843
TI - A study of the coregulation and tissue specificity of XG and MIC2 gene expression
in eukaryotic cells.
AB - CD99, the product of the MIC2 gene, exhibits an erythroid-specific quantitative
polymorphism coregulated with the polymorphism of the XG blood group gene. As a
preliminary study of this phenomenon, human XG and CD99 recombinant proteins were
expressed in murine RAG cells and analyzed by flow cytometry. Both proteins were
expressed independently and at a similar level in single and double
transfectants. Immunoprecipitation and Western blot analysis, using the murine
monoclonal antibodies NBL-1 and 12E7, revealed species of 26 kd (XG) and 32 kd
(CD99), respectively. A putative 28-kd intracellular precursor of CD99 was also
detected, as was a 26-kd species after neuraminidase treatment of CD99-expressing
cells. No evidence of association or complex formation between XG and CD99
proteins could be proven, either on transfected RAG cells or on human
erythrocytes. These results were confirmed using somatic hybrids between single
transfectants. These findings suggest that the phenotypic relationship between XG
and CD99 is mostly regulated at the transcriptional level, but they do not
formally exclude some posttranscriptional effect. Studies on the tissue
specificity of XG expression showed that surface expression of the XG protein
could not be restored in somatic hybrids between B-lymphoblastoid cell lines from
Xg(a+) persons and fibroblasts (RAG) or erythroid (MEL) cells. RT-PCR analysis of
the transcripts revealed the existence of an XG mRNA in each cell line,
suggesting that the tissue-specific regulation of cell surface XG expression
occurs either at a quantitative transcriptional level or is a posttranscriptional
event. By Northern blot analysis, XG transcripts were detected in erythroid
tissues and several nonerythroid tissues. (Blood. 2000;95:1819-1826)
PMID- 10688844
TI - Fetal expression of a human Agamma globin transgene rescues globin chain
imbalance but not hemolysis in EKLF null mouse embryos.
AB - Mice lacking the erythroid Kruppel-like factor (EKLF) die in utero at embryonic
day 15 (E15) from severe anemia. EKLF(-/-) embryos display a marked deficit in
beta-globin gene expression. To test whether beta-globin deficiency was solely
responsible for the anemia and intrauterine death, we corrected the globin chain
imbalance in EKLF(-/-) embryos by breeding with a strain of mice that express
high levels of human gamma-globin. Despite efficient production of hybrid
malpha(2)-hgamma(2) hemoglobin in the fetal livers of EKLF(-/-) animals,
hemolysis was not corrected and survival was not prolonged. We concluded that
deficiency of nonglobin EKLF target genes is a major contributor to the
definitive red blood cell abnormalities and prenatal death in EKLF(-/-) embryos.
These results suggest that strategies designed to antagonize EKLF function in
adults with hemoglobinopathy, in an attempt to reactivate gamma-globin gene
expression, may adversely affect other essential aspects of red blood cell
physiology. (Blood. 2000;95:1827-1833)
PMID- 10688845
TI - Elliptocytosis in patients with C-terminal domain mutations of protein 4.1
correlates with encoded messenger RNA levels rather than with alterations in
primary protein structure.
AB - Early biochemical studies defined 4 functional domains of the erythroid protein
4.1 (4.1R). From amino-terminal to carboxy-terminal, these are 30 kd, 16 kd, 10
kd, and 22/24 kd in size. Although the functional properties of both the 30-kd
and the 10-kd domain have been demonstrated in red cells, no functional
activities have been assigned to either the 16-kd or the 22/24-kd domain in these
cells. We here describe new mutations in the sequence encoding the C-terminal
22/24-kd domain that are associated with hereditary elliptocytosis. An unusually
mild phenotype observed in heterozygous and homozygous members of 1 family
suggested heterogeneity in the pattern of expression of 4.1R deficiency. Using a
variety of protein and messenger RNA (mRNA) quantification strategies, we showed
that, regardless of the alteration in the C-terminal primary sequence, when the
protein is produced, it assembles at the cell membrane. In addition, we found
that alterations in red cell morphologic features and membrane function correlate
with the amount of membrane-associated protein-and therefore with the amount of
mRNA accumulated-rather than with the primary structure of the variant proteins.
These data suggest that an intact sequence at exons 19 through 21 encoding part
of the C-terminal 22/24-kd region is not required for proper protein 4.1R
assembly in mature red cells. (Blood. 2000;95:1834-1841)
PMID- 10688846
TI - Volume control in sickle cells is facilitated by the novel anion conductance
inhibitor NS1652.
AB - A low cation conductance and a high anion conductance are characteristic of
normal erythrocytes. In sickle cell anemia, the polymerization of hemoglobin S
(HbS) under conditions of low oxygen tension is preceded by an increase in cation
conductance. This increase in conductance is mediated in part through Ca(++)
activated K(+) channels. A net efflux of potassium chloride (KCl) leads to a
decrease in intracellular volume, which in turn increases the rate of HbS
polymerization. Treatments minimizing the passive transport of ions and solvent
to prevent such volume depletion might include inhibitors targeting either the
Ca(++)-activated K(+) channel or the anion conductance. NS1652 is an anion
conductance inhibitor that has recently been developed. In vitro application of
this compound lowers the net KCl loss from deoxygenated sickle cells from about
12 mmol/L cells/h to about 4 mmol/L cells/h, a value similar to that observed in
oxygenated cells. Experiments performed in mice demonstrate that NS1652 is well
tolerated and decreases red cell anion conductance in vivo. (Blood. 2000;95:1842
1848)
PMID- 10688847
TI - Single amino acid substitution in human platelet glycoprotein Ibbeta is
responsible for the formation of the platelet-specific alloantigen Iy(a).
AB - We recently described a new low-frequency platelet alloantigen on the human
platelet glycoprotein (GP) Ib-IX complex, termed Iy(a), which was implicated in a
severe case of neonatal alloimmune thrombocytopenia. Immunoprecipitation studies
with trypsin-treated platelets indicated that the Iy(a) alloantigenic
determinants are formed by the membrane-associated remnant moiety of GP Ibalpha
(GP Ibalpha(r)) together with GP Ibbeta and GP IX. To elucidate the molecular
basis underlying the Iy(a) alloantigen, we amplified GPIbalpha(r), GPIbbeta, and
GPIX genes by polymerase chain reaction (PCR). Nucleotide-sequence analysis of
these 3 genes showed a G to A transition at position 141 on GPIbbeta gene in a
subject positive for Iy(a). This transition resulted in a Gly(15)Glu dimorphism
on the N-terminal domain of GPIbbeta. This finding was confirmed by genotyping
analysis of 6 Iy(a)-positive subjects by restriction fragment length polymorphism
(RFLP) studies using NarI endonuclease. In 300 randomly selected healthy blood
donors, one Iy(a)-positive individual was found. Phenotypes determined by
monoclonal antibody-specific immobilization of platelet antigens assay and
genotypes determined by RFLP were identical in this population. Analysis of Iy(a)
positive platelets showed that the point mutation affected neither the degree of
surface expression nor the function of the GP Ibalpha-GP Ibbeta-IX complex on the
platelet surface. Transient expression of the GP Ib-IX complex in CHO cells using
wild-type GP Ibbeta (Gly(15)) or mutant GP Ibbeta (Glu(15)) allowed us to
demonstrate that this single amino acid substitution is sufficient to induce
Iy(a) epitope(s). (Blood. 2000;95:1849-1855)
PMID- 10688848
TI - Vasoactive side effects of intravenous immunoglobulin preparations in a rat model
and their treatment with recombinant platelet-activating factor acetylhydrolase.
AB - Previously, we observed in a rat model that intravenous administration of
intramuscular immunoglobulin preparations induced a long-lasting hypotension,
which appeared to be associated with the presence of IgG polymers and dimers in
the preparations, but unrelated to complement activation. We found evidence that
this hypotensive response is mediated by platelet-activating factor (PAF)
produced by macrophages. In this study, we compared the vasoactive effects of 16
intravenous immunoglobulin (IVIG) products from 10 different manufacturers, in
anesthetized rats. Eight of the IVIG preparations showed no hypotensive effects
(less than 15% decrease), whereas the other 8 had relatively strong effects (15%
50% decrease). The hypotensive effects correlated with the IgG dimer content of
the preparations. Pretreatment of the rats with recombinant PAF acetylhydrolase
completely prevented the hypotensive reaction on IVIG infusion, and
administration after the onset of hypotension resulted in normalization of the
blood pressure. We also observed PAF production on in vitro incubation of human
neutrophils with IVIG, which could be blocked by anti-Fcgamma receptor
antibodies. This indicates that induction of PAF generation may also occur in a
human system. Our findings support the hypothesis that the clinical side effects
of IVIG in patients may be caused by macrophage and neutrophil activation through
interaction of IgG dimers with Fcgamma receptors. Because phagocyte activation
may also lead to the release of other inflammatory mediators, recombinant PAF
acetylhydrolase (rPAF-AH) provides a useful tool to determine whether PAF plays a
role in the clinical side effects of IVIG. If so, rPAF-AH can be used for the
treatment of those adverse reactions. (Blood. 2000;95:1856-1861)
PMID- 10688850
TI - Germline CDKN2A mutation implicated in predisposition to multiple myeloma.
AB - Germline mutations of the CDKN2A (p16(INK4A)) tumor suppressor gene predispose
patients to melanoma and pancreatic carcinoma. In contrast, mutations of the
murine CDKN2A gene predispose BALB/c mice to pristane-induced plasmacytoma. We
describe here a family in which a germline mutation of CDKN2A is present in 4
individuals who developed melanoma as well as in a fifth family member who is
suffering from multiple myeloma. To determine whether the CDKN2A mutation
predisposed the myeloma patient to her disease, we carried out loss of
heterozygosity studies on sorted bone marrow from this individual and observed
loss of the wild type CDKN2A allele in the malignant plasma cells. We suggest
that germline mutations of CDKN2A may predispose individuals to a wider variety
of malignancy than has been hitherto reported, but that the expression of these
cancers may depend heavily on the genetic background of the patient. (Blood.
2000;95:1869-1871)
PMID- 10688849
TI - Treatment of intractable autoimmune diseases in MRL/lpr mice using a new strategy
for allogeneic bone marrow transplantation.
AB - A new bone marrow transplantation (BMT) method for treating severe autoimmune
diseases in chimeric resistant MRL/lpr mice is presented. The method consists of
fractionated irradiation (5.5 Gy x 2), followed by portal venous (PV) injection
of whole bone marrow cells (BMCs) from allogeneic normal C57BL/6 (B6) mice and
intravenous (IV) injection of whole B6 BMCs 5 days after the PV injection
(abbreviated as 5.5 Gy x 2 + PV + IV). All recipients survived more than 1 year
after this treatment (more than 64 weeks after birth). Abnormal T cells
(Thy1.2(+)/B220(+)/CD3(+)/CD4(-)/CD8(-)) present in MRL/lpr mice before the
treatment disappear, and hematolymphoid cells are reconstituted with donor
derived cells. The treated mice are free from autoimmune diseases. Levels of
autoantibodies (IgG/IgM anti-ssDNA antibodies and IgG/IgM rheumatoid factors)
decrease to normal levels. Successful cooperation is achieved among T cells, B
cells, and antigen-presenting cells (APCs) of the treated MRL/lpr mice when
evaluated by in vitro anti-SRBC responses. Newly developed T cells are tolerant
to both donor (B6)-type and host (MRL/lpr)-type major histocompatibility complex
(MHC) determinants. These findings clearly indicate that severe autoimmune
diseases in MRL/lpr mice are completely ameliorated by the treatment without
recourse to immunosuppressants, and that the treated MRL/lpr mice show normal
immune functions, strongly suggesting that this strategy would be applicable to
humans. (Blood. 2000;95:1862-1868)
PMID- 10688851
TI - Progenitor cell mobilization by granulocyte colony-stimulating factor controlled
by loci on chromosomes 2 and 11.
AB - Granulocyte colony-stimulating factor (G-CSF) can effectively mobilize
hematopoietic stem and progenitor cells from bone marrow into blood, thereby
allowing peripheral blood stem cells (PBSCs) to be used for transplantation. The
efficiency of PBSC mobilization response to G-CSF is a multigene trait. DBA/2
(high-responder) and C57BL/6 (low-responder) mice were used for a genetic
analysis of G-CSF-induced progenitor release. Significant linkages were found on
chromosome 2 by analyzing segregation distortion among the high responders of 500
backcross mice and on chromosome 11 by using the quantitative trait locus
analysis of 26 strains of BXD recombinant inbred mice. (Blood. 2000;95:1872-1874)
PMID- 10688852
TI - Carcinogenesis, 1980
PMID- 10688853
TI - Overview of carcinogenesis: past, present and future.
AB - In the foregoing articles, the editors of Carcinogenesis have identified the
major themes of current carcinogenesis research and assembled an outstanding
group of authors to review these areas. I have been asked to provide a historical
overview of past accomplishments and describe how these contributed to the
broader efforts to overcome the burden of human cancer. My assignment also
included a look into the future. As scientists we formulate hypotheses that
attempt to predict the future. Occasionally we are successful. The pioneers of
carcinogenesis research were remarkably successful in predicting the future.
Armed with primitive technology relative to today, these scientists studied the
biology of carcinogenesis and conceptualized a framework for cancer pathogenesis
that virtually everyone working in cancer research follows today. The current
generation has been charged with filling in the details. In the details lay the
future. Together with past accomplishments, these emerging details form a
remarkable picture of progress in understanding and application, creating
realistic and imminent promise to achieve victory in the fight against cancer.
PMID- 10688854
TI - Metabolism of chemical carcinogens.
AB - The transformation of chemicals is important in carcinogenesis, both in
bioactivation and detoxification. Major advances in the past 20 years include
appreciation of the migration of reactive electrophiles, the ability of Phase II
conjugating enzymes to activate chemicals, understanding of the human enzymes,
the realization that DNA modification can result from endogenous chemicals, and
the demonstration that cancers can result from the metabolism of chemicals to non
covalently bound products. Pathways of transformation in which major insight was
gained during the past 20 years include nitropolycyclic hydrocarbons, polycyclic
hydrocarbons and their diols, vinyl halides and dihaloalkanes. Advances in
analytical methods and recombinant DNA technology contributed greatly to the
study of metabolism of chemical carcinogens. Major advances have been made in the
assignment of roles of individual enzymes in reactions. The knowledge developed
in this field has contributed to growth in the areas of chemoprevention,
molecular epidemiology and species comparisons of risk. Some of the areas in
which future development relevant to carcinogen metabolism is expected involve
pathways of transformation of certain chemicals, regulation of genes coding for
many of the enzymes under consideration and genomics.
PMID- 10688855
TI - Carcinogen macromolecular adducts and their measurement.
AB - Damage to DNA induced by carcinogenic chemicals reflects exposure and is directly
related to tumor formation, whereas modification of protein provides relatively
precise dosimetry for stable adducts of proteins with a known half-life.
Sophisticated methods for the detection and quantitation of DNA and protein
adducts have been developed during the last approximately 25 years. For DNA
adducts the most widely used methods include electrochemical detection, mass
spectrometry, fluorescence and phosphorescence spectroscopy, immunoassays and
immunohistochemistry and (32)P-post-labeling. Detection limits for quantitative
assays are typically in the range of 1 adduct in 10(7) or 10(9) nucleotides.
However, accelerator mass spectrometry, which is highly sophisticated but less
accessible, has a detection limit of approximately 1 adduct in 10(12)
nucleotides. Methods for the determination of protein adducts include immunoassay
and a variety of elegant high-resolution mass spectrometry approaches. The
detection limit of approximately 0.1 fmol for protein adducts, is based primarily
on method specificity and the availability of large quantities of sample
material. Using these highly sensitive methods a major achievement has been the
biomonitoring of chemically exposed human populations. Validation of
macromolecular adduct formation in humans has been predicated on studies in
animal models. Adduct formation in humans appears to be indicative of molecular
dosimetry and suggestive of increased human cancer risk. However, despite the
large body of literature documenting DNA and protein adduct molecular dosimetry
for many carcinogen exposures, the relationship between adduct formation and
human cancer risk has been defined for only a few carcinogens. Thus, elucidation
of this association remains a compelling challenge. For the future, integration
of DNA and protein adduct measurements together with documentation of correlative
and subsequent events, and host susceptibility factors, within the context of
valid molecular epidemiologic study designs, will further our understanding of
human disease mechanisms.
PMID- 10688856
TI - Oxyradicals and DNA damage.
AB - A major development of carcinogenesis research in the past 20 years has been the
discovery of significant levels of DNA damage arising from endogenous cellular
sources. Dramatic improvements in analytical chemistry have provided sensitive
and specific methodology for identification and quantitation of DNA adducts.
Application of these techniques to the analysis of nuclear DNA from human tissues
has debunked the notion that the human genome is pristine in the absence of
exposure to environmental carcinogens. Much endogenous DNA damage arises from
intermediates of oxygen reduction that either attack the bases or the
deoxyribosyl backbone of DNA. Alternatively, oxygen radicals can attack other
cellular components such as lipids to generate reactive intermediates that couple
to DNA bases. Endogenous DNA lesions are genotoxic and induce mutations that are
commonly observed in mutated oncogenes and tumor suppressor genes. Their
mutagenicity is mitigated by repair via base excision and nucleotide excision
pathways. The levels of oxidative DNA damage reported in many human tissues or in
animal models of carcinogenesis exceed the levels of lesions induced by exposure
to exogenous carcinogenic compounds. Thus, it seems likely that oxidative DNA
damage is important in the etiology of many human cancers. This review highlights
some of the major accomplishments in the study of oxidative DNA damage and its
role in carcinogenesis. It also identifies controversies that need to be
resolved. Unraveling the contributions to tumorigenesis of DNA damage from
endogenous and exogenous sources represents a major challenge for the future.
PMID- 10688857
TI - Carcinogenesis in mouse and human cells: parallels and paradoxes.
AB - It has been known since the last century that genetic changes are important in
carcinogenesis [Boveri,T. (1914) Zur Frage der Erstehung Maligner Tumoren. Gustav
Fischer, Jena]. Observations of tumor cells growing in tissue culture led to the
prediction, even before the true nature of the genetic material was known, that
alterations at the chromosomal level were critically involved in the process of
neoplastic development. The past 20 years have seen the transition of
carcinogenesis studies from the purely observational to the molecular genetic
level. Although much more needs to be done, it is nevertheless gratifying to be
able to piece together the sequence of events from carcinogen exposure,
metabolism of the carcinogen to the activated form, formation of specific
carcinogen-DNA adducts, misrepair leading to the fixation of mutations in
particular target genes, and the resulting selective outgrowth of neoplastic
cells. The nature of many of these steps has been clarified only in the
relatively recent past, and only for a small number of specific target genes, but
the fact that we can say with confidence that such processes occur and are causal
changes in tumorigenesis represents a tremendous advance over the situation
pertaining 20 years ago. The purpose of this review is to summarize the advances
over this time period in our understanding of some of the genetic alterations
that contribute to neoplasia, with particular emphasis on chemical carcinogenesis
in rodents and the parallels with transformation of human cells.
PMID- 10688858
TI - Significance of multiple mutations in cancer.
AB - There is increasing evidence that in eukaryotic cells, DNA undergoes continuous
damage, repair and resynthesis. A homeostatic equilibrium exists in which
extensive DNA damage is counterbalanced by multiple pathways for DNA repair. In
normal cells, most DNA damage is repaired without error. However, in tumor cells
this equilibrium may be skewed, resulting in the accumulation of multiple
mutations. Among genes mutated are those that function in guaranteeing the
stability of the genome. Loss of this stability results in a mutator phenotype.
Evidence for a mutator phenotype in human cancers includes the frequent
occurrence of gene amplification, microsatellite instability, chromosomal
aberrations and aneuploidy. Current experiments have centered on two mechanisms
for the generation of genomic instability, one focused on mutations in mismatch
repair genes resulting in microsatellite instability, and one focused on
mutations in genes that are required for chromosomal segregation resulting in
chromosomal aberrations. This dichotomy may reflect only the ease by which these
manifestations can be identified. Underlying both pathways may be a more general
phenomenon involving the selection for mutator genes during tumor progression.
During carcinogenesis there is selection for cells harboring mutations that can
overcome adverse conditions that limit tumor growth. These mutations are produced
by direct DNA damage as well as secondarily as a result of mutations in genes
that cause a mutator phenotype. Thus, as tumor progression selects for cells with
specific mutations, it also selects for cancer cells harboring mutations in genes
that normally function in maintaining genetic instability.
PMID- 10688859
TI - Nutrition and dietary carcinogens.
AB - Three major factors for human carcinogenesis are (i) cigarette smoking, (ii)
infection and inflammation and (iii) nutrition and dietary factors. Nutrition and
dietary factors include two categories, namely genotoxic agents and constituents
including tumor promotion-associated phenomena. This article first describes the
genotoxic agents as microcomponents. These are mutagens/carcinogens in cooked
food, fungal products, plant and mushroom substance, and nitrite-related
materials, polycyclic aromatic hydrocarbons and oxidative agents. Emphasis has
been given to heterocyclic amines (HCAs) to which humans are continuously exposed
in an ordinary lifestyle. HCAs in food are mainly produced from creatin(in)e,
sugar and from amino acids in meat (upon heating). They are imidazoquinoline and
imidazoquinoxaline derivatives and phenylimidazopyridine. HCAs are pluripotent in
producing cancers in various organs including breast, colon and prostate.
Discussion is also given to plant flavonoids which are mutagenic but not
carcinogenic. As a macrocomponent, overintake of total calories, fat and sodium
chloride is discussed from the viewpoint of the increase of genetic alterations
in tissues and of tumor promotion-associated issues. Studies of nutrition and
dietary condition will eventually lead us to cancer prevention, namely delay of
onset of cancer to the late phase of human life, which is called 'natural-end
cancer' (Tenju-gann).
PMID- 10688860
TI - Radiation carcinogenesis.
AB - Research on radiation carcinogenesis during the past 2 decades has focused on
cellular and molecular mechanisms for the effects of radiation in mammalian
cells. This paper will review several of these areas of research, as they may
relate specifically to the induction of cancer by ionizing radiation. Knowledge
of the critical DNA damage of biologic importance, and how this damage is
repaired, will be discussed in relation to its role in the induction of mutations
by radiation. The search for the initiating event in radiation carcinogenesis, as
well as other genetic events that may be involved, is discussed in terms of the
possible role of the activation of oncogenes or tumor suppressor genes and the
loss of cell-cycle checkpoints. Finally, evidence will be described indicating
that important genetic consequences of radiation may arise in cells that in
themselves receive no direct nuclear irradiation. It has been shown that
radiation can, by itself, induce a type of genomic instability in cells, which
enhances the rate at which mutations and other genetic changes arise in the
descendants of the irradiated cell after many generations of replication.
Preliminary evidence has been presented that irradiation targeted to the
cytoplasm yields a significant increase in the frequency of mutations. Finally,
genetic events including the induction of mutations and changes in gene
expression may occur in neighboring cells that receive no direct radiation
exposure at all. This 'bystander effect' involves gap junction mediated cell-cell
communication, and activation of the p53 damage response pathway. The possible
role of these phenomena in radiation carcinogenesis is discussed.
PMID- 10688861
TI - Viral carcinogenesis: revelation of molecular mechanisms and etiology of human
disease.
AB - The RNA and DNA tumor viruses have made fundamental contributions to two major
areas of cancer research. Viruses were vital, first, to the discovery and
analysis of cellular growth control pathways and the synthesis of current
concepts of cancer biology and, second, to the recognition of the etiology of
some human cancers. Transforming retroviruses carry oncogenes derived from
cellular genes that are involved in mitogenic signalling and growth control. DNA
tumor viruses encode oncogenes of viral origin that are essential for viral
replication and cell transformation; viral oncoproteins complex with cellular
proteins to stimulate cell cycle progression and led to the discovery of tumor
suppressors. Viral systems support the concept that cancer development occurs by
the accumulation of multiple cooperating events. Viruses are now accepted as bona
fide etiologic factors of human cancer; these include hepatitis B virus, Epstein
Barr virus, human papillomaviruses, human T-cell leukemia virus type I and
hepatitis C virus, plus several candidate human cancer viruses. It is estimated
that 15% of all human tumors worldwide are caused by viruses. The infectious
nature of viruses distinguishes them from all other cancer-causing factors; tumor
viruses establish long-term persistent infections in humans, with cancer an
accidental side effect of viral replication strategies. Viruses are usually not
complete carcinogens, and the known human cancer viruses display different roles
in transformation. Many years may pass between initial infection and tumor
appearance and most infected individuals do not develop cancer, although
immunocompromised individuals are at elevated risk of viral-associated cancers.
Variable factors that influence viral carcinogenesis are reviewed, including
possible synergy between viruses and environmental cofactors. The difficulties in
establishing an etiologic role for a virus in human cancer are discussed, as well
as the different approaches that proved viral links to cancer. Future directions
for tumor virus studies are considered.
PMID- 10688862
TI - Hormonal carcinogenesis.
AB - Hormone-related cancers, namely breast, endometrium, ovary, prostate, testis,
thyroid and osteosarcoma, share a unique mechanism of carcinogenesis. Endogenous
and exogenous hormones drive cell proliferation, and thus the opportunity for the
accumulation of random genetic errors. The emergence of a malignant phenotype
depends on a series of somatic mutations that occur during cell division, but the
specific genes involved in progression of hormone-related cancers are currently
unknown. In this review, the epidemiology of endometrial cancer and breast cancer
are used to illustrate the paradigms of hormonal carcinogenesis. Then, new
strategies for early detection and prevention of hormonal carcinogenesis are
discussed. This includes developing polygenic models of cancer predisposition and
the further development of safe and effective chemopreventives that block target
sequence activity. We developed polygenic models for breast and prostate cancer
after hypothesizing that functionally relevant sequence variants in genes
involved in steroid hormone metabolism and transport would act together, and also
interact with well-known hormonally related risk factors, to define a high-risk
profile for cancer. A combination of genes each with minor variation in expressed
activity could provide a degree of separation of risk that would be clinically
useful as they could yield a large cumulative difference after several decades.
The genes included in the breast cancer model are the 17beta-hydroxysteroid
dehydrogenase 1 (HSD17B1) gene, the cytochrome P459c17alpha (CYP17) gene, the
aromatase (CYP19) gene, and the estrogen receptor alpha (ER) gene. The prostate
cancer model includes the androgen receptor gene (AR), steroid 5alpha-reductase
type II (SRD5A2), CYP17 and the 3beta hydroxysteroid dehydrogenase (HSD3B2) gene.
We present data from our multi-ethnic cohort to support these models.
PMID- 10688863
TI - Manipulating the germline: its impact on the study of carcinogenesis.
AB - Over the past two decades, the mouse has established itself as the primary
organism in which to investigate the fundamental mechanisms of carcinogenesis and
to model human neoplasia. The principal reason underlying such dominance almost
certainly arises out of our ever increasing ability to manipulate the murine
germline. Over the past 20 years we have moved from a position where animal
models arose either spontaneously or were generated through exposure to
carcinogen to a position in which it is possible to create and study precise
mutations of choice. The most recent advances in inducible and conditional
technologies now open the possibility for both temporal and tissue-specific gene
manipulation. Each of these technological breakthroughs has facilitated
significant steps forward in our understanding of the genetic basis of
tumorigenesis. This review will highlight some of the major advances in the
production and use of murine models of neoplasia over the last two decades.
PMID- 10688864
TI - Genome changes and gene expression in human solid tumors.
AB - Genome-wide analysis techniques such as chromosome painting, comparative genomic
hybridization, representational difference analysis, restriction landmark genome
scanning and high-throughput analysis of LOH are now accelerating high-resolution
genome aberration localization in human tumors. These techniques are complemented
by procedures for detection of differentially expressed genes such as
differential display, nucleic acid subtraction, serial analysis of gene
expression and expression microarray analysis. These efforts are enabled by work
from the human genome program in physical map development, cDNA library
production/sequencing and in genome sequencing. This review covers several
commonly used large-scale genome and gene expression analysis techniques,
outlines genomic approaches to gene discovery and summarizes information that has
come from large-scale analyses of human solid tumors.
PMID- 10688865
TI - Nucleotide excision repair and human syndromes.
AB - DNA damage is implicated in cancer and aging, and several DNA repair mechanisms
exist that safeguard the genome from these deleterious consequences. Nucleotide
excision repair (NER) removes a wide diversity of lesions, the main of which
include UV-induced lesions, bulky chemical adducts and some forms of oxidative
damage. The NER process involves the action of at least 30 proteins in a 'cut-and
paste'-like mechanism. The consequences of a defect in one of the NER proteins
are apparent from three rare recessive syndromes: xeroderma pigmentosum (XP),
Cockayne syndrome (CS) and the photosensitive form of the brittle hair disorder
trichothiodystrophy (TTD). Sun-sensitive skin is associated with skin cancer
predisposition in the case of XP, but remarkably not in CS and TTD. Moreover, the
spectrum of clinical symptoms differs considerably between the three syndromes.
CS and TTD patients exhibit a spectrum of neurodevelopmental abnormalities and,
in addition, TTD is associated with ichthyosis and brittle hair. These typical CS
and TTD abnormalities are difficult to comprehend as a consequence of defective
NER. This review briefly describes the biochemistry of the NER process,
summarizes the clinical features of the NER disorders and speculates on the
molecular basis underlying these pleitropic syndromes.
PMID- 10688866
TI - DNA methylation: past, present and future directions.
AB - DNA methylation, or the covalent addition of a methyl group to cytosine within
the context of the CpG dinucleotide, has profound effects on the mammalian
genome. These effects include transcriptional repression via inhibition of
transcription factor binding or the recruitment of methyl-binding proteins and
their associated chromatin remodeling factors, X chromosome inactivation,
imprinting and the suppression of parasitic DNA sequences. DNA methylation is
also essential for proper embryonic development; however, its presence can add an
additional burden to the genome. Normal methylation patterns are frequently
disrupted in tumor cells with global hypomethylation accompanying region-specific
hypermethylation. When these hypermethylation events occur within the promoter of
a tumor suppressor gene they will silence the gene and provide the cell with a
growth advantage in a manner akin to deletions or mutations. Recent work
indicating that DNA methylation is an important player in both DNA repair and
genome stability as well as the discovery of a new family of DNA
methyltransferases makes now a very exciting period for the methylation field.
This review will highlight the major findings in the methylation field over the
past 20 years then summarize the most important and interesting future directions
the field is likely to take in the next millennium.
PMID- 10688867
TI - Stem cells: the intestinal stem cell as a paradigm.
AB - Stem cell research provides a foundation for therapeutic advancement in oncology,
clinical genetics and a diverse array of degenerative disorders. For example, the
elucidation of pathways governing proliferative regulation and differentiation
within cellular systems will result in medical strategies aimed at the root cause
of cancer. At present the characterization of reliable stem cell markers is the
immediate aim in this particular field. Over the past 30 years investigators have
determined many of the physical and functional properties of stem cells through
careful and imaginative experimentation. Intestinal stem cells reside at the
crypt base and give rise to all cell types found within the crypt. They readily
undergo altruistic apoptosis in response to toxic stimuli although their progeny
are hardier and will regain stem cell function to repopulate the tissue
compartment, giving rise to the concept of a proliferative hierarchy. Contention
exists when deciding whether the full complement of cells within a crypt is
derived from either a single or multiple stems. Evidence has also arisen to
challenge the long held view that colorectal tumours arise from a single mutated
stem cell, as early adenomas from a human XO/XY mosaic contained distinct clones.
Mechanisms governing the stem cell cycle and subsequent proliferative activity
largely remain obscure. The adenomatous polyposis coli gene product has, however,
been shown to promote the degradation of beta-catenin, an enhancer of cell
proliferation, thereby downregulating this activity in healthy individuals.
PMID- 10688868
TI - The role of senescence and immortalization in carcinogenesis.
AB - Normal somatic cells are able to divide only a limited number of times before
they become senescent. The occurrence of intratumoral cell death and the need for
clonal evolution mean that many more cell divisions are required for
tumorigenesis than is possible unless cells breach the senescence proliferation
barrier and become immortalized. Senescence may therefore be a major tumor
suppressor mechanism. During the past decade the study of senescence and
immortalization has entered the mainstream of cancer research. A major reason for
the current interest in this subject is the observation that most cancers have an
activated telomere maintenance mechanism, a marker of immortalization. It has
also been found that some of the most common genetic changes known to occur in
cancer have a key role in the immortalization process.
PMID- 10688869
TI - Apoptosis in cancer.
AB - In the last decade, basic cancer research has produced remarkable advances in our
understanding of cancer biology and cancer genetics. Among the most important of
these advances is the realization that apoptosis and the genes that control it
have a profound effect on the malignant phenotype. For example, it is now clear
that some oncogenic mutations disrupt apoptosis, leading to tumor initiation,
progression or metastasis. Conversely, compelling evidence indicates that other
oncogenic changes promote apoptosis, thereby producing selective pressure to
override apoptosis during multistage carcinogenesis. Finally, it is now well
documented that most cytotoxic anticancer agents induce apoptosis, raising the
intriguing possibility that defects in apoptotic programs contribute to treatment
failure. Because the same mutations that suppress apoptosis during tumor
development also reduce treatment sensitivity, apoptosis provides a conceptual
framework to link cancer genetics with cancer therapy. An intense research effort
is uncovering the underlying mechanisms of apoptosis such that, in the next
decade, one envisions that this information will produce new strategies to
exploit apoptosis for therapeutic benefit.
PMID- 10688870
TI - Tumor progression and metastasis.
AB - It is now widely accepted that cancer is attributed to the accumulation of
genetic alterations in cells. Thus, to understand the molecular mechanisms of
cancer metastasis, it is indispensable to identify the genes whose alterations
accumulate during cancer progression as well as the genes whose expression is
responsible for the acquisition of metastatic potential in cancer cells.
Molecular analyses of cancer cells in various stages of progression have revealed
that alterations in tumor suppressor genes and oncogenes accumulate during tumor
progression and correlate with the clinical aggressiveness of cancer. Comparative
analyses of gene expression profiles between metastatic and non-metastatic cells
have revealed that various genes are differentially expressed in association with
the metastatic potential of cancer cells. A number of genes have been also
identified as having functions in inducing or suppressing metastasis in
experimental models. However, the association between causative genetic
alterations and resulting phenotypic alterations with respect to the metastatic
potential of cancer cells is not fully understood. Therefore, elucidation of
genotype-phenotype correlation will be required to further understand a complex
process of metastasis. Here, I review the progress on molecular studies of tumor
progression and metastasis of the past 20 years and discuss the future direction
in this field of science.
PMID- 10688871
TI - Tumor angiogenesis: past, present and the near future.
AB - The concept of treating solid tumors by inhibiting tumor angiogenesis was first
articulated almost 30 years ago. For the next 10 years it attracted little
scientific interest. This situation changed, relatively slowly, over the
succeeding decade with the discovery of the first pro-angiogenic molecules such
as basic fibroblast growth factor and vascular endothelial growth factor (VEGF),
and the development of methods of successfully growing vascular endothelial cells
in culture as well as in vivo assays of angiogenesis. However, the 1990s have
witnessed a striking change in both attitude and interest in tumor angiogenesis
and anti-angiogenic drug development, to the point where a remarkably diverse
group of over 24 such drugs is currently undergoing evaluation in phase I, II or
III clinical trials. In this review I will discuss the many reasons for this.
These features, together with other recent discoveries have created intense
interest in initiating and expanding anti-angiogenic drug discovery programs in
both academia and industry, and the testing of such newly developed drugs, either
alone, or in various combinations with conventional cytotoxic therapeutics.
However, significant problems remain in the clinical application of angiogenesis
inhibitors such as the need for surrogate markers to monitor the effects of such
drugs when they do not cause tumor regressions, and the design of clinical
trials. Also of concern is that the expected need to use anti-angiogenic drugs
chronically will lead to delayed toxic side effects in humans, which do not
appear in rodents, especially in short-term studies.
PMID- 10688872
TI - Molecular epidemiology: recent advances and future directions.
AB - In 1982 we proposed the concept and a framework for implementing molecular cancer
epidemiology. Here, we review progress during the past 17 years in validating and
applying this approach to cancer prevention. There have been major advances,
notably in the understanding of environment-susceptibility interactions in human
cancer. However, a review of major findings to date reveals several urgent
research needs to keep pace with the rapid evolution in knowledge of mechanisms
in carcinogenesis. Although much valuable progress continues to be made in the
study of carcinogens that cause direct DNA damage and are mutagenic, exogenous
and endogenous carcinogens can also act by altering gene expression, cell
proliferation and differentiation. The mechanisms include aberrant DNA
methylation, oxidative damage, effects on metabolism of nitrogen oxide and
nitrites, activation of receptors and transcription factors, cyclins and other
cell cycle proteins. Sensitive, validated biomarkers are needed to detect these
mechanisms in small numbers of cells, tissues or fluids. There is also increasing
recognition that individual risk from carcinogen exposure varies as a function of
both inherited and acquired factors. Recent advances in genomics, microassay
technologies and informatics hold promise for rapid identification of polymorphic
variants or changes in expression of genes influencing both response and
susceptibility to carcinogens. Another emerging area of molecular epidemiology
concerns the role of nutrition and specific dietary factors (including studies on
antioxidants, energy metabolism, insulin and various growth factors) and the
modulating effect of genetic polymorphisms. Finally, molecular epidemiology has
enormous potential in cancer prevention through the early identification of 'at
risk' populations and the rapid assessment of intervention efficacy. Its success
in fully reaching this potential will depend on the application of validated
biomarkers, with adherence to sound epidemiologic and ethical principles.
PMID- 10688873
TI - Chemoprevention of cancer.
AB - In this short article, we review the conceptual basis for chemoprevention of
cancer, the proven clinical efficacy of this concept, and current trends to
develop new chemopreventive agents based on understanding of their mechanisms of
action. Four classes of new agents, namely selective inhibitors of cyclooxygenase
2, selective estrogen receptor modulators, rexinoids (retinoids that bind
selectively to the receptors known as RXRs) and ligands for the peroxisome
proliferator-activated receptor-gamma are discussed in detail. The importance of
developing totally new classes of chemopreventive agents is stressed, with
particular emphasis on the potential usefulness of new synthetic triterpenoids
derived from naturally occurring molecules.
PMID- 10688874
TI - beta 3: an additional auxiliary subunit of the voltage-sensitive sodium channel
that modulates channel gating with distinct kinetics.
AB - The voltage-sensitive sodium channel confers electrical excitability on neurons,
a fundamental property required for higher processes including cognition. The ion
conducting alpha-subunit of the channel is regulated by two known auxiliary
subunits, beta1 and beta2. We have identified rat and human forms of an
additional subunit, beta3. It is most closely related to beta1 and is the product
of a separate gene localized to human chromosome 11q23.3. When expressed in
Xenopus oocytes, beta3 inactivates sodium channel opening more slowly than beta1
does. Structural modeling has identified an amino acid residue in the putative
alpha-subunit binding site of beta3 that may play a role in this difference. The
expression of beta3 within the central nervous system differs significantly from
beta1. Our results strongly suggest that beta3 performs a distinct
neurophysiological function.
PMID- 10688875
TI - Spatial order within but not between types of retinal neurons.
AB - We studied the mosaics of six types of retinal neurons, asking how the position
of a cell relates to the positions of other cells of that same type and also to
cells of different types. Every neuron studied was found to be nonrandomly
positioned: Cells of a particular type were evenly spaced. However, all cells
were positioned randomly with respect to members of the other cell classes. This
was true even when the cells were known to be synaptically connected. It is
consistent with a concept of developmental pattern formation in which (i) the
number of cells of a particular type and their laminar distribution are
specified, and (ii) the final spatial position of each cell is controlled
exclusively by a rule that prevents cells of the same type from being positioned
close to each other. This sequence would imply that a cell's final position is
independent of the cell's position at the time of its specification, and we
suggest a reason why, in laminar structures containing many cell types, it might
be desirable for this to be so.
PMID- 10688876
TI - Erectile dysfunction in cyclic GMP-dependent kinase I-deficient mice.
AB - The generation of nitric oxide (NO) in penile erectile tissue and the subsequent
elevation of cyclic GMP (cGMP) levels are important for normal penile erection.
Current treatments of erectile dysfunction elevate either cGMP levels by blocking
cGMP degrading phosphodiesterase 5 or cyclic AMP (cAMP) levels by intrapenile
injection of prostaglandin E1. The molecular target or targets of cGMP in
erectile tissue and the role of cAMP for normal penile erection are not known.
Herein, we report that mice lacking cGMP-dependent kinase I (cGKI) have a very
low ability to reproduce and that their corpora cavernosa fail to relax on
activation of the NO/cGMP signaling cascade. Elevation of cAMP by forskolin,
however, induces similar relaxation in normal and cGKI-null corpus cavernosum. In
addition, sperm derived from cGKI-null mice is normal, can undergo acrosomal
reactions, and can efficiently fertilize eggs. Altogether, these data identify
cGKI as the downstream target of cGMP in erectile tissue and provide evidence
that cAMP signaling cannot compensate for the absence of the cGMP/cGKI signaling
cascade in vivo.
PMID- 10688877
TI - Quantitative analysis of the effect of the mutation frequency on the affinity
maturation of single chain Fv antibodies.
AB - Random mutagenesis and selection using phage or cell surface display provides an
efficient method for affinity maturation of single chain Fv (scFv) antibodies,
thereby improving function in various applications. To investigate the effects of
mutation frequency on affinity maturation, error-prone PCR was used to generate
libraries containing an average (m) of between 1.7 and 22.5 base substitutions
per gene in a high affinity scFv antibody that binds to the cardiac glycoside
digoxigenin. The scFv antibody libraries were displayed on Escherichia coli, and
mutant populations were analyzed by flow cytometry. At low to moderate mutation
frequencies with an average mutation rate of m = 8, the fraction of clones
exhibiting binding to a fluorescently labeled conjugate of digoxigenin decreased
exponentially (r(2) = 0.99), but the most highly mutated library (m = 22.5) had
significantly more active clones than expected relative to this trend. A library
with a low error rate (m = 1.7), one with moderate error rate (m = 3.8), and the
one with high error rate (m = 22.5) were screened for high affinity clones under
conditions of identical stringency using fluorescence-activated cell sorting.
After several rounds of enrichment, each of the three libraries yielded clones
with improved affinity for the hapten. The moderate and high error rate libraries
gave rise to clones exhibiting the greatest affinity improvement. Taken together,
our results indicate that (i) functional clones occur at an unexpectedly high
frequency in hypermutated libraries, (ii) gain-of-function mutants are well
represented in such libraries, and (iii) the majority of the scFv mutations
leading to higher affinity correspond to residues distant from the binding site.
PMID- 10688878
TI - A space-time structure determination of human CD2 reveals the CD58-binding mode.
AB - We describe a procedure for a space-time description of protein structures. The
method is capable of determining populations of conformational substates, and
amplitudes and directions of internal protein motions. This is achieved by
fitting static and dynamic NMR data. The approach is based on the jumping-among
minima concept. First, a wide conformational space compatible with structural NMR
data is sampled to find a large set of substates. Subsequently, intrasubstate
motions are sampled by using molecular dynamics calculations with force field
energy terms. Next, the populations of substates are fitted to NMR relaxation
data. By diagonalizing a second moment matrix, directions and amplitudes of
motions are identified. The method was applied to the adhesion domain of human
CD2. We found that very few substates can account for most of the experimental
data. Furthermore, only two types of collective motions have high amplitudes.
They represent transitions between a concave (closed) and flat (open) binding
face and resemble the change upon counter-receptor (CD58) binding.
PMID- 10688879
TI - The movement protein NSm of tomato spotted wilt tospovirus (TSWV): RNA binding,
interaction with the TSWV N protein, and identification of interacting plant
proteins.
AB - The nonstructural NSm protein of tomato spotted wilt tospovirus (TSWV) represents
a putative viral movement protein involved in cell-to-cell movement of
nonenveloped ribonucleocapsid structures. To study the molecular basis of NSm
function, we expressed the protein in Escherichia coli and investigated protein
protein and protein-RNA interactions of NSm protein in vitro. NSm specifically
interacts with TSWV N protein and binds single-stranded RNA in a sequence
nonspecific manner. Using NSm as a bait in a yeast two-hybrid screen, we
identified two homologous NSm-binding proteins of the DnaJ family from Nicotiana
tabacum and Arabidopsis thaliana.
PMID- 10688880
TI - Identification of a natural soluble neuropilin-1 that binds vascular endothelial
growth factor: In vivo expression and antitumor activity.
AB - Neuropilin-1 (NRP1) is a 130-kDa transmembrane receptor for semaphorins,
mediators of neuronal guidance, and for vascular endothelial growth factor 165
(VEGF(165)), an angiogenesis factor. A 2.2-kb truncated NRP1 cDNA was cloned that
encodes a 644-aa soluble NRP1 (sNRP1) isoform containing just the a/CUB and
b/coagulation factor homology extracellular domains of NRP1. sNRP1 is secreted by
cells as a 90-kDa protein that binds VEGF(165), but not VEGF(121). It inhibits
(125)I-VEGF(165) binding to endothelial and tumor cells and VEGF(165)-induced
tyrosine phosphorylation of KDR in endothelial cells. The 3' end of sNRP1 cDNA
contains a unique, 28-bp intron-derived sequence that is absent in full-length
NRP1 cDNA. Using a probe corresponding to this unique sequence, sNRP1 mRNA could
be detected by in situ hybridization differentially from full-length NRP1 mRNA,
for example, in cells of liver, kidney, skin, and breast. Analysis of blood
vessels in situ showed that NRP1, but not sNRP1, was expressed. sNRP1 was
functional in vivo. Unlike control tumors, tumors of rat prostate carcinoma cells
expressing recombinant sNRP1 were characterized by extensive hemorrhage, damaged
vessels, and apoptotic tumor cells. These results demonstrate the existence of a
naturally occurring, soluble NRP1 that is expressed differently from intact NRP1
and that appears to be a VEGF(165) antagonist.
PMID- 10688881
TI - Benzo[a]pyrene diol epoxide adducts in DNA are potent suppressors of a normal
topoisomerase I cleavage site and powerful inducers of other topoisomerase I
cleavages.
AB - The catalytic intermediates of DNA topoisomerase I (top1) are cleavage complexes
that can relax DNA supercoiling (intramolecular reaction) or mediate
recombinations (intermolecular religation). We report here that DNA adducts
formed from benzo[a]pyrene bay-region diol epoxides can markedly affect top1
activity. Four oligonucleotide 22-mers of the same sequence were synthesized,
each of which contained a stereoisomerically unique benzo[a]pyrene 7, 8-diol 9,10
epoxide adduct at the 2-amino group of a central 2'-deoxyguanosine residue. These
four adducts correspond to either cis or trans opening at C-10 of the (+)-(7R,
8S, 9S, 10R)- or (-)-(7S, 8R, 9R, 10S)-7,8-diol 9,10-epoxides. Their solution
conformations in duplex DNA (intercalated and minor-groove bound for the cis and
trans opened adducts respectively) can be deduced from previous NMR studies. All
four adducts completely suppress top1 cleavage activity at the alkylation site
and induce the formation of new top1cleavage complexes on both strands of the DNA
3-6 bases away from the alkylation site. The trans opened adduct from the highly
carcinogenic (+)-diol epoxide is the most active in inducing top1 cleavage
independently of camptothecin, demonstrating that minor groove alkylation can
efficiently poison top1. We also found that this isomer of the diol epoxide
induces the formation of top1-DNA complexes in mammalian cells, which suggests a
possible relationship between induction of top1 cleavage complexes and
carcinogenic activity of benzo[a]pyrene diol epoxides.
PMID- 10688882
TI - Cyclic peptide formation catalyzed by an antibody ligase.
AB - Cyclic hexapeptides represent a class of compounds with important, diverse
biological activities. We report herein that the antibody 16G3 catalyzes the
cyclization of d-Trp-Gly-Pal-Pro-Gly-Phe small middle dotp-nitrophenyl ester (8a)
to give c-(d-Trp-Gly-Pal-Pro-Gly-l-Phe) (11a). The antibody does not, however,
catalyze either epimerization or hydrolysis. The resulting rate enhancement of
the cyclization by 16G3 (22-fold) was sufficient to form the desired product in
greater than 90% yield. In absolute rate terms, the turnover of 16G3 is estimated
to be 2 min(-1). The background rate of epimerization of 8a was reduced from 10
to 1% and hydrolysis from 50 to 4% in the presence of 16G3. As expected, the
catalytic effects of 16G3 were blocked by the addition of an amount of the hapten
equal to twice the antibody concentration. We also synthesized three
diastereomers of 8a: the d-Trp(1)-d-Phe(6) (8b), l-Trp(1)-l-Phe(6) (8c), and l
Trp(1)-d-Phe(6) (8d) hexapeptides as well as d-Trp'-l-Trp(6) (12) and d-Phe'-l
Phe(6) (13). As expected, the rate enhancement by 16G3 was greatest for 8a,
because the stereochemistry of Trp(1) and Phe(6) matches that of the
corresponding residues on the hapten used to induce the biosynthesis of 16G3. A
model of the variable domain of 16G3 was generated from the primary sequence
using the antibody structural database to guide the model construction. The
resulting model provided support for some previously proposed interpretations of
the kinetic data, while providing valuable new insights for others.
PMID- 10688883
TI - Density per particle as a descriptor of Coulombic systems.
AB - It is shown that for finite Coulombic systems the density per particle, final
sigma identical with rho/N, determines the value of any observable quantity. The
associated variational principle is derived.
PMID- 10688884
TI - A common pharmacophore for epothilone and taxanes: molecular basis for drug
resistance conferred by tubulin mutations in human cancer cells.
AB - The epothilones are naturally occurring antimitotic drugs that share with the
taxanes a similar mechanism of action without apparent structural similarity.
Although photoaffinity labeling and electron crystallographic studies have
identified the taxane-binding site on beta-tubulin, similar data are not
available for epothilones. To identify tubulin residues important for epothilone
binding, we have isolated two epothilone-resistant human ovarian carcinoma
sublines derived in a single-step selection with epothilone A or B. These
epothilone-resistant sublines exhibit impaired epothilone- and taxane-driven
tubulin polymerization caused by acquired beta-tubulin mutations (beta274(Thr-
>Ile) and beta282(Arg-->Gln)) located in the atomic model of alphabeta-tubulin
near the taxane-binding site. Using molecular modeling, we investigated the
conformational behavior of epothilone, which led to the identification of a
common pharmacophore shared by taxanes and epothilones. Although two binding
modes for the epothilones were predicted, one mode was identified as the
preferred epothilone conformation as indicated by the activity of a potent
pyridine-epothilone analogue. In addition, the structure-activity relationships
of multiple taxanes and epothilones in the tubulin mutant cells can be fully
explained by the model presented here, verifying its predictive value. Finally,
these pharmacophore and activity data from mutant cells were used to model the
tubulin binding of sarcodictyins, a distinct class of microtubule stabilizers,
which in contrast to taxanes and the epothilones interact preferentially with the
mutant tubulins. The unification of taxane, epothilone, and sarcodictyin
chemistries in a single pharmacophore provides a framework to study drug-tubulin
interactions that should assist in the rational design of agents targeting
tubulin.
PMID- 10688885
TI - Dynamic sensory sensitivity and children's word decoding skills.
AB - The relationship between sensory sensitivity and reading performance was examined
to test the hypothesis that the orthographic and phonological skills engaged in
visual word recognition are constrained by the ability to detect dynamic visual
and auditory events. A test battery using sensory psychophysics, psychometric
tests, and measures of component literacy skills was administered to 32
unselected 10-year-old primary school children. The results suggest that
children's sensitivity to both dynamic auditory and visual stimuli are related to
their literacy skills. Importantly, after controlling for intelligence and
overall reading ability, visual motion sensitivity explained independent variance
in orthographic skill but not phonological ability, and auditory FM sensitivity
covaried with phonological skill but not orthographic skill. These results
support the hypothesis that sensitivity at detecting dynamic stimuli influences
normal children's reading skills. Vision and audition separately may affect the
ability to extract orthographic and phonological information during reading.
PMID- 10688887
TI - Mammalian and chicken I forms of gonadotropin-releasing hormone in the gonads of
a protochordate, Ciona intestinalis.
AB - Two forms of gonadotropin-releasing hormone (GnRH) were isolated from the gonads
of the tunicate, Ciona intestinalis. The primary structure of the purified
peptides was determined by MS and chemical sequence analysis. Both GnRH forms
have blocked NH(2) and COOH termini, and their primary structures are identical
to mammalian (mGnRH) and chicken I (cGnRH-I) forms reported previously in
vertebrates. A total of 1.2 mg of purified cGnRH-I and 0.98 mg of mGnRH was
obtained from 100 g of Ciona gonads. The physiological effects of native GnRHs
included the induction of synthesis and secretion of sex steroids from ciona
gonads and the secretion of luteinizing hormone from rat pituitary. These results
suggest that the primary structure and functional roles of mGnRH and cGnRH-I have
been highly conserved throughout evolution of chordates.
PMID- 10688886
TI - Tyrosine phosphorylation of p62dok by p210bcr-abl inhibits RasGAP activity.
AB - The t(9;22) chromosomal translocation is found in almost all patients with
chronic myelogenous leukemia. The resultant Bcr-Abl fusion gene expresses a
chimeric fusion protein p210(bcr-abl) with increased tyrosine kinase activity.
Hematopoietic progenitors isolated from chronic myelogenous leukemia patients in
the chronic phase contain constitutively tyrosine-phosphorylated p62(dok)
protein. p62(dok) associates with the Ras GTPase-activating protein (RasGAP), but
only when p62(dok) is tyrosine phosphorylated. Here we have investigated the
interaction between p62(dok) and RasGAP and the consequences of p62(dok) tyrosine
phosphorylation on the activity of RasGAP. We have found that p62(dok) is
directly tyrosine phosphorylated by p210(bcr-abl), and the sites of
phosphorylation are located in the C-terminal half of the p62(dok) molecule. We
have identified five tyrosine residues that are involved in in vitro RasGAP
binding and have found that tyrosine-phosphorylated p62(dok) inhibits RasGAP
activity. Our results suggest that p210(bcr-abl) might lead to the activation of
the Ras signaling pathway by inhibiting a key down-regulator of Ras signaling.
PMID- 10688889
TI - Light affects cAMP signaling and cell movement activity in Dictyostelium
discoideum.
AB - The multicellular, slug stage of the slime mould Dictyostelium discoideum lacks
specific sensory cells and organs but can nevertheless respond in a very
sensitive manner to external stimuli such as temperature and light. Within the
migrating slug, the behavior of up to 100,000 individual amoebae is coordinated
by cAMP mediated cell-cell signaling and chemotaxis. We report here the striking
result that light directly modulates the cAMP cell-cell signaling system. Light
induced secretion of cAMP from the slug tips decreased the period length of
optical density waves and speeded up cell movement. A local effect of light on
cAMP release within the slug tip could modulate cell movement within the slug and
thus control its phototactic turning and orientation toward a light source.
PMID- 10688888
TI - Molecular basis of a progressive juvenile-onset hereditary cataract.
AB - In a recent paper, patients with a progressive juvenile-onset hereditary cataract
have been reported to have a point mutation in the human gammaD crystallin gene
(Stephan, D. A., Gillanders, E., Vanderveen, D., Freas-Lutz, D., Wistow, G.,
Baxevanis, A. D., Robbins, C. M., VanAuken, A., Quesenberry, M. I., Bailey
Wilson, J., et al. (1999) Proc. Natl. Acad. Sci. USA 96, 1008-1012). This
mutation results in the substitution of Arg-14 in the native protein by a Cys
residue. It is not understood how this mutation leads to cataract. We have
expressed recombinant wild-type human gammaD crystallin (HGD) and its Arg-14 to
Cys mutant (R14C) in Escherichia coli and show that R14C forms disulfide-linked
oligomers, which markedly raise the phase separation temperature of the protein
solution. Eventually, R14C precipitates. In contrast, HGD slowly forms only
disulfide-linked dimers and no oligomers. These data strongly suggest that the
observed cataract is triggered by the thiol-mediated aggregation of R14C. The
aggregation profiles of HGD and R14C are consistent with our homology modeling
studies that reveal that R14C contains two exposed cysteine residues, whereas HGD
has only one. Our CD, fluorescence, and differential scanning calorimetric
studies show that HGD and R14C have nearly identical secondary and tertiary
structures and stabilities. Thus, contrary to current views, unfolding or
destabilization of the protein is not necessary for cataractogenesis.
PMID- 10688890
TI - Carbonic anhydrase inhibitor suppresses invasion of renal cancer cells in vitro.
AB - Acidification of the extracellular milieu of malignant tumors is reported to
increase the invasive behavior of cancer cells. In normal tissues, production of
acid is catalyzed by carbonic anhydrases (CAs), some of which are known to be
overexpressed in certain cancers. To investigate the functional role of CA
activity in such cancer cells, we analyzed the effect of acetazolamide, a potent
CA inhibitor, on the invasive capacity of four renal carcinoma cell lines (Caki
1, Caki-2, ACHN, and A-498). We found that 10 microM acetazolamide inhibited the
relative invasion rate of these cell lines between 18-74%. The Caki-2 and ACHN
cell lines displayed the highest responsiveness, and their responses clearly
depended on the acetazolamide concentration in the culture medium.
Immunocytochemical and Western blotting results identified the presence of CA
isoenzyme II in the cytoplasm of all four cell lines and CA XII on the plasma
membrane in three of four cell lines. Because acetazolamide alone reduced
invasiveness of these cancer cells in vitro, we conclude that the CAs
overexpressed in these renal cancer cells contribute to invasiveness, at least in
vitro, and suggest that CA inhibitors may also reduce invasiveness in other
tumors that overexpress one or more CAs.
PMID- 10688891
TI - Neuroimaging evidence implicating cerebellum in support of sensory/cognitive
processes associated with thirst.
AB - Recent studies implicate the cerebellum, long considered strictly a motor control
structure, in cognitive, sensory, and affective phenomenon. The cerebellum, a
phylogenetically ancient structure, has reciprocal ancient connections to the
hypothalamus, a structure important in vegetative functions. The present study
investigated whether the cerebellum was involved in vegetative functions and the
primal emotions engendered by them. Using positron emission tomography, we
examined the effects on the cerebellum of the rise of plasma sodium concentration
and the emergence of thirst in 10 healthy adults. The correlation of regional
cerebral blood flow with subjects' ratings of thirst showed major activation in
the vermal central lobule. During the development of thirst, the anterior and
posterior quadrangular lobule, lingula, and the vermis were activated. At maximum
thirst and then during irrigation of the mouth with water to alleviate dryness,
the cerebellum was less activated. However, 3 min after drinking to satiation,
the anterior quadrangular lobule and posterior cerebellum were highly activated.
The increased cerebellar activity was not related to motor behavior as this did
not occur. Instead, responses in ancient cerebellar regions (vermis, fastigal
nucleus, archicerebellum) may be more directly related to vegetative and
affective aspects of thirst experiences, whereas activity in neocerebellar
(posterior) regions may be related to sensory and cognitive aspects. Moreover,
the cerebellum is apparently not involved in the computation of thirst per se but
rather is activated during changes in thirst/satiation state when the brain is
"vigilant" and is monitoring its sensory systems. Some neocerebellar activity may
also reflect an intentionality for gratification by drinking inherent in the
consciousness of thirst.
PMID- 10688892
TI - Caspase-3: A vulnerability factor and final effector in apoptotic death of
dopaminergic neurons in Parkinson's disease.
AB - Caspase-3 is an effector of apoptosis in experimental models of Parkinson's
disease (PD). However, its potential role in the human pathology remains to be
demonstrated. Using caspase-3 immunohistochemistry on the postmortem human brain,
we observed a positive correlation between the degree of neuronal loss in
dopaminergic (DA) cell groups affected in the mesencephalon of PD patients and
the percentage of caspase-3-positive neurons in these cell groups in control
subjects and a significant decrease of caspase-3-positive pigmented neurons in
the substantia nigra pars compacta of PD patients compared with controls that
also could be observed in an animal model of PD. This suggests that neurons
expressing caspase-3 are more sensitive to the pathological process than those
that do not express the protein. In addition, using an antibody raised against
activated caspase-3, the percentage of active caspase-3-positive neurons among DA
neurons was significantly higher in PD patients than in controls. Finally,
electron microscopy analysis in the human brain and in vitro data suggest that
caspase-3 activation precedes and is not a consequence of apoptotic cell death in
PD.
PMID- 10688893
TI - Membrane hyperpolarization removes inactivation of Ca2+ channels, leading to Ca2+
influx and subsequent initiation of sperm motility in the common carp.
AB - Change of osmolality surrounding spawned sperm from isotonic to hypotonic causes
the initiation of sperm motility in the common carp. Here we show that membrane
permeable cAMP does not initiate motility of carp sperm that is quiescent in
isotonic solution, and that motility of the demembranated sperm can be
reactivated without cAMP. Furthermore, the cAMP level does not change during the
initiation of sperm motility, and inhibitors of protein kinase do not affect
sperm motility, suggesting that no cAMP-dependent system is necessary for the
regulation of sperm motility. Sperm motility could not be initiated in Ca(2+)
free hypoosmotic solutions, and significant increase in the intracellular Ca(2+)
level was observed by a Ca-sensitive fluorescence dye during hypoosmolality
induced active motion period. The demembranated sperm cells were fully
reactivated in the solutions containing 10(-7) to 10(-5) M Ca(2+). Ca(2+) channel
blockers such as verapamil and omega-conotoxin reversibly inhibited the
initiation of sperm motility, suggesting that Ca(2+) influx is the prerequisite
for the initiation of carp sperm motility. Motility of intact sperm was
completely blocked; however, that of the demembranated sperm was not inhibited by
the calmodulin inhibitor W7, suggesting that the calmodulin bound close to the
plasma membrane participated in the initiation of sperm motility. Flow cytometric
membrane potential measurements and spectrophotometric measurements by using
fluorescence dyes showed transient membrane hyperpolarization on hypoosmolality
induced motility. This article discusses the role of membrane hyperpolarization
on removal of inactivation of Ca(2+) channels, leading to Ca(2+) influx at the
initiation of carp sperm motility.
PMID- 10688894
TI - Viral persistence in vivo through selection of neutralizing antibody-escape
variants.
AB - Despite initial virus control by CD8(+) cytotoxic T lymphocytes (CTLs),
noncytopathic or variably cytopathic viruses (e.g., hepatitis B and C viruses,
HIV) are able to establish persistent infections. The role of neutralizing
antibodies (nAbs) in controlling disease progression is unclear. Therefore, the
phenomenon of viral evasion from the nAb response and its implications for virus
persistence remain controversial. Here we demonstrate nAb-mediated viral
clearance in CTL-deficient mice infected with the prototypic noncytopathic
lymphocytic choriomeningitis virus (strain WE). During prolonged CTL absence,
neutralization-resistant virus mutants were selected in individual mice within 70
90 days. In naive animals infected with these virus variants only low nAb
responses were induced, resulting in an increased tendency of virus to persist.
PMID- 10688895
TI - Marking synaptic activity in dendritic spines with a calpain substrate exhibiting
fluorescence resonance energy transfer.
AB - Excitatory synaptic activity can evoke transient and substantial elevations of
postsynaptic calcium. Downstream effects of elevated calcium include the
activation of the calcium-dependent protease calpain. We have developed a reagent
that identifies dendritic spines in which calpain has been activated. A fusion
protein was expressed that contained enhanced yellow and enhanced cyan
fluorescent protein (EYFP and ECFP, respectively) linked by a peptide that
included the micro-calpain cleavage site from alpha-spectrin. A PDZ-binding site
fused to ECFP anchored this protein to postsynaptic densities. The fusion protein
exhibited fluorescence resonance energy transfer (FRET), and diminution of FRET
by proteolysis was used to localize calpain activity in situ by fluorescence
microscopy. Incubation of the fusion protein with calpain in the presence of
calcium resulted in the separation of EYFP and ECFP into monomeric fluorophores.
In transiently transfected cell lines and dissociated hippocampal neurons, FRET
was diminished by raising intracellular calcium levels with an ionophore or with
glutamatergic agonists. Calpain inhibitors blocked these changes. Under control
conditions, FRET levels in different dendritic spines of cultured neurons and in
hippocampal slices were heterogeneous but showed robust decreases upon treatment
with glutamatergic agonists. Immunostaining of cultured neurons with antibodies
to a spectrin epitope produced by calpain-mediated digestion revealed an inverse
correlation between the amount of FRET present at postsynaptic elements and the
concentration of spectrin breakdown products. These results suggest that the FRET
methodology identifies sites of synaptically induced calpain activity and that it
may be useful in analyzing synapses undergoing changes in efficacy.
PMID- 10688896
TI - Inhibitory pathways and the inhibition of luteinizing hormone-releasing hormone
release by alcohol.
AB - In this research we examined the mechanisms by which ethanol (EtOH) inhibits
luteinizing hormone-releasing hormone (LHRH) release from incubated medial basal
hypothalamic explants. EtOH (100 mM) stimulated the release of two inhibitory
neurotransmitters: gamma-aminobutyric acid (GABA) and beta-endorphin. EtOH also
inhibited NO production, indicative of a suppression of nitric oxide synthase
(NOS) activity. This inhibition was reversed by naltroxone (10(-8) M), a micro
opioid receptor blocker, indicating that the inhibition of NOS by EtOH is
mediated by beta-endorphin. EtOH also blocked N-methyl-d-aspartic acid-induced
LHRH release, but the blockade could not be reversed by either the GABA receptor
blocker, bicuculline (10(-5) M), naltroxone (10(-8) M), or both inhibitors added
together. However, increasing the concentration of naltrexone (10(-6) M) but not
bicuculline (10(-4) M) reversed the inhibition. When we lowered the concentration
of EtOH (50 mM), the EtOH-induced blockade of LHRH release could be reversed by
either bicuculline (10(-5) M), naltroxone (10(-8) M), or the combination of the
two blockers. Therefore, GABA is partially responsible for the blockade of N
methyl-d-aspartic acid-induced LHRH release. The block by GABA was exerted by
inhibiting the activation of cyclooxygenase by NO, because it was reversed by
prostaglandin E(2), the product of activation of cyclooxygenase. Because the
inhibition caused by the higher concentration of EtOH could not be reduced by
bicuculline (10(-4) M) but was blocked by naltroxone (10(-6) M), the action of
alcohol can be accounted for by stimulation of beta-endorphin neurons that
inhibit LHRH release by inhibition of activation of NOS and stimulation of GABA
release.
PMID- 10688897
TI - The structure of a stable intermediate in the A <--> B DNA helix transition.
AB - The DNA dodecamer CATGGGCCCATG in a crystal structure of resolution 1.3 A has a
conformation intermediate between A and B DNA. This trapping of a stable
intermediate suggests that the A and B DNA families are not discrete, as
previously believed. The structure supports a base-centered rather than a
backbone-centered mechanism for the A <--> B transition mediated by guanine
tracts. Interconversion between A and B DNA provides another means for regulating
protein-DNA recognition.
PMID- 10688899
TI - Isolation of peptide aptamers that inhibit intracellular processes.
AB - We have developed a method for isolation of random peptides that inhibit
intracellular processes in bacteria. A library of random peptides expressed as
fusions to Escherichia coli thioredoxin (aptamers) were expressed under the tight
control of the arabinose-inducible P(BAD) promoter. A selection was applied to
the library to isolate aptamers that interfered with the activity of thymidylate
synthase (ThyA) in vivo. Expression of an aptamer isolated by this method
resulted in a ThyA(-) phenotype that was suppressed by simultaneous
overexpression of ThyA. Two-hybrid analysis showed that this aptamer is likely to
interact with ThyA in vivo. The library also was screened for aptamers that
inhibited growth of bacteria expressing them, and five such aptamers were
characterized. Four aptamers were bacteriostatic when expressed, whereas one
showed a bactericidal effect. Introduction of translational stop codons into
various aptamers blocked their activity, suggesting that their biological effects
were likely to be due to protein aptamer rather than RNA. Combinatorial aptamers
provide a new genetic and biochemical tool for identifying targets for
antibacterial drug development.
PMID- 10688898
TI - The EntF and EntE adenylation domains of Escherichia coli enterobactin
synthetase: sequestration and selectivity in acyl-AMP transfers to thiolation
domain cosubstrates.
AB - Enterobactin, the tris-(N-(2,3-dihydroxybenzoyl)serine) trilactone siderophore of
Escherichia coli, is synthesized by a three-protein (EntE, B, F) six-module
nonribosomal peptide synthetase (NRPS). In this work, the 142-kDa four-domain
protein EntF was bisected into two double-domain fragments: a 108-kDa
condensation and adenylation construct, EntF C-A, and a 37-kDa peptidyl carrier
protein (PCP) and thioesterase protein, EntF PCP-TE. The adenylation domain
activity of EntF C-A formed seryl-AMP but lost the ability to transfer the seryl
moiety to the cognate EntF PCP-TE in trans. Seryl transfer to heterologous PCP
protein fragments, the SrfB1 PCP from surfactin synthetase and Ybt PCP1 from
yersiniabactin synthetase, was observed at rates of 0.5 min(-1) and 0.01 min(-1),
respectively. The possibility that these slow acylation rates reflected
dissociation of acyl/aminoacyl-AMP followed by adventitious thiolation by the
heterologous PCPs in solution was addressed by measuring catalytic turnover of
pyrophosphate (PP(i)) released from the adenylation domain. The holo SrfB1 PCP
protein as well as Ybt PCP1 did not stimulate an increase in PP(i) release from
EntF C-A or EntE. In this light, aminoacylations in trans between A and PCP
domain fragments of NRPS assembly lines must be subjected to kinetic scrutiny to
determine whether transfer is truly between protein domains or results from slow
aminoacyl-AMP release and subsequent nonenzymatic thiol capture.
PMID- 10688900
TI - The amino terminus of the mixed lineage leukemia protein (MLL) promotes cell
cycle arrest and monocytic differentiation.
AB - Several lines of evidence suggest that the mixed lineage leukemia protein (MLL,
ALL-1, HRX) plays a role in regulating myelomonocytic differentiation. In this
study we examined the effect of expression of MLL-AF9 on differentiation of the
monoblastic U937 cell line by using a tetracycline-inducible expression system.
MLL-AF9 arrested growth of U937 cells and induced these cells to differentiate
into macrophages; induction was accompanied by expression of CD11b and CD14 and
ultimately cell death. Deletion mutants of MLL-AF9 were used to map the sequences
responsible for this effect. The amino-terminal half of MLL was sufficient for
both cell cycle arrest and macrophage differentiation, whereas the carboxyl
terminus of MLL or AF9 was found to be dispensable for this effect. Further
deletions showed that a 35-kDa amino-terminal fragment spanning two AT hook
motifs was sufficient for cell cycle arrest, up-regulation of p21(Cip1) and
p27(Kip1), and partial differentiation toward macrophages. These findings suggest
a possible role for the MLL AT hook-containing region in regulating
myelomonocytic differentiation.
PMID- 10688901
TI - The B cell-restricted adaptor BASH is required for normal development and antigen
receptor-mediated activation of B cells.
AB - B cell antigen receptor signals development, activation, proliferation, or
apoptosis of B cells depending on their condition, and its proper signaling is
critical for activation and homeostasis of the immune system. The B cell
restricted adaptor protein BASH (also termed BLNK/SLP-65) is rapidly
phosphorylated by the tyrosine kinase Syk after BCR ligation and binds to various
signaling proteins. BASH structurally resembles SLP-76, which is essential for T
cell development and T cell receptor signaling. To evaluate the role for BASH in
B cell development and function in vivo, we disrupted BASH alleles in embryonic
stem cells by means of homologous recombination and used these cells to
complement lymphocyte-incompetent blastocysts from RAG2-deficient mice. In the
resultant chimeric mice, T cell development was apparently normal, but B cell
development was impaired, and a normally rare population of large preB cells
expressing preB cell receptor dominated in the bone marrow in place of small preB
cells, although they were mostly noncycling. In addition, the mature B cell
populations in the periphery and the bone marrow profoundly decreased in size, as
did B-1 cells in the peritoneal cavity, and serum Ig was severely reduced. The
BASH-deficient B cells scarcely proliferated or up-regulated B7-2 in response to
BCR ligation and poorly proliferated upon CD40 ligation or lipopolysaccharide
stimulation. This phenotype indicates that BASH is critical for preB cell
receptor signaling inducing proliferation of large preB cells and the following
differentiation, for peripheral B cell maturation, and for BCR signaling inducing
activation/proliferation of B cells.
PMID- 10688902
TI - Place recognition monitored by location-driven operant responding during passive
transport of the rat over a circular trajectory.
AB - Spatial memory of animals is usually tested in navigation tasks that do not allow
recognition and recall processes to be separated from the mechanisms of goal
directed locomotion. In the present study, place recognition was examined in rats
(n = 7) confined in an operant chamber mounted on the periphery of a slowly
rotating disk (diameter 1 m, angular velocity 9 degrees /s). The animals were
passively transported over a circular trajectory and were rewarded for bar
pressing when they passed across a 60 degrees -wide segment of the path. This
segment was recognizable with reference to room landmarks visible from the
operant box. Responding defined in the coordinate system of the room increased
when the chamber entered the 60 degrees -wide approach zone, culminated at the
entrance into the reward sector, was decreased inside it by eating the available
reward, and rapidly declined to zero at the exit from this zone. When reward was
discontinued, the skewed response distribution changed into a symmetric one with
a maximum in the center of the reward sector. With advancing extinction, the
response peak in the reward sector decreased in most rats proportionally to the
overall decline of bar pressing. The rewarded and nonrewarded response patterns
indicate that passively transported rats can recognize their position in the
environment with an accuracy comparable to that of actively navigating animals
and that location-driven operant responding can serve as a useful tool in the
analysis of the underlying neural mechanisms.
PMID- 10688904
TI - Candidate tumor suppressor RIZ is frequently involved in colorectal
carcinogenesis.
AB - The distal portion of chromosome 1p is one of the most commonly affected regions
in human cancer. In this study of hereditary and sporadic colorectal cancer, a
region of frequent deletion was identified at 32.2 centimorgans from 1ptel.
Deletion breakpoints clustered in the vicinity of or inside the gene RIZ, which
encodes a retinoblastoma protein-interacting zinc finger protein. Sequence
analysis revealed frequent frameshift mutations of the RIZ gene. The mutations
consisted of 1- or 2-bp deletions of a coding (A)(8) or (A)(9) tract and were
confined to microsatellite-unstable colorectal tumors, being present in 9 of 24
(37.5%) primary tumors and in 6 of 11 (54.5%) cell lines; in 2 cell lines the
mutation was homozygous/hemizygous. The mutations apparently were selected
clonally in tumorigenesis, because similar poly(A) tracts in other genes were not
affected. Two alternative products of the gene exist, RIZ1, which contains a PR
(PRDI-BF1-RIZ1) domain implicated in tumor suppressor function, and RIZ2, which
is lacking this motif. Furthermore, the C-terminal region, which contains the
poly(A) tracts, includes a PR-binding motif, possibly mediating interactions with
other proteins or with RIZ itself (oligomerization). Four of eleven
microsatellite-unstable colorectal cancer cell lines, three of which had
frameshifts, showed reduced or absent mRNA expression of RIZ1. In a cell line
that is homozygous/hemizygous for the typical frameshift mutation, immunoblotting
showed truncated RIZ protein, whereas adenovirus-mediated RIZ1 expression caused
G(2)/M arrest and apoptosis. We propose that RIZ is a target of the observed 1p
alterations, with impairment of the PR domain-mediated function through either
frameshift mutation or genomic deletion.
PMID- 10688905
TI - 5-hydroxytryptamine 2B receptor regulates cell-cycle progression: cross-talk with
tyrosine kinase pathways.
AB - In this paper, we present evidence that activation of 5-hydroxytryptamine 2B (5
HT2B) receptors by serotonin (5-HT) leads to cell-cycle progression through
retinoblastoma protein hyperphosphorylation and through activation of both cyclin
D1/cdk4 and cyclin E/cdk2 kinases by a mechanism that depends on induction of
cyclin D1 and cyclin E protein levels. The induction of cyclin D1 expression, but
not that of cyclin E, is under mitogen-activated protein kinase (MAPK) control,
indicating an independent regulation of these two cyclins in the 5-HT2B receptor
mitogenesis. Moreover, by using the specific platelet-derived growth factor
receptor (PDGFR) inhibitor AG 1296 or by overexpressing a kinase-mutant PDGFR, we
show that PDGFR kinase activity is essential for 5-HT2B-triggered MAPK/cyclin D1,
but not cyclin E, signaling pathways. 5-HT2B receptor activation also increases
activity of the Src family kinase, c-Src, Fyn, and c-Yes. Strikingly, c-Src, but
not Fyn or c-Yes, is the crucial molecule between the G(q) protein-coupled 5-HT2B
receptor and the cell-cycle regulators. Inhibition of c-Src activity by 4-amino-5
(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP1) or depletion of c-Src
is sufficient to abolish the 5-HT-induced (i) PDGFR tyrosine kinase
phosphorylation and MAPK activation, (ii) cyclin D1 and cyclin E expression
levels, and (iii) thymidine incorporation. This paper elucidates a model of 5
HT2B receptor mitogenesis in which c-Src acts alone to control cyclin E induction
and in concert with the receptor tyrosine kinase PDGFR to induce cyclin D1
expression via the MAPK/ERK pathway.
PMID- 10688906
TI - A B-cell receptor-specific selection step governs immature to mature B cell
differentiation.
AB - Seventy percent of peripheral immature conventional (B2) B cells fail to develop
into mature B cells. The nature of this cell loss has not been characterized; the
process that governs which immature B cells develop into long-lived peripheral B
cells could be either stochastic or selective. Here, we demonstrate that this
step is in fact selective, in that the fate of an immature B cell is highly
dependent on its Ig receptor specificity. A significant skewing of the B cell
receptor repertoire occurs by the time cells enter the mature B cell fraction,
which indicates that there is selection of only a minority of immature B cells to
become mature B cells. Because only a few heavy-light chain pairs are enhanced of
the diverse available repertoire, we favor the idea that selection is positive
for these few heavy-light chain pairs rather than negative against nearly all
others. Because most immature B cells are lost at this transition, this putative
positive selection event is likely to be a major force shaping the mature B cell
receptor repertoire available for adaptive immune responses.
PMID- 10688907
TI - Rat strain-specific actions of 17beta-estradiol in the mammary gland: correlation
between estrogen-induced lobuloalveolar hyperplasia and susceptibility to
estrogen-induced mammary cancers.
AB - The genetically related ACI and Copenhagen (COP) rat strains display
diametrically opposed susceptibilities to mammary cancer development when treated
chronically with 17beta-estradiol (E2). Here, we compare the actions of E2 on
cell proliferation and lobuloalveolar development in the mammary glands of female
ACI and COP rats. After 12 wk of E2 treatment, the mammary glands of ACI rats
exhibited a significantly greater proliferative response to E2, compared with COP
rats, as evidenced by quantification of S phase fraction and development of
lobuloalveolar hyperplasia. Focal regions of atypical epithelial hyperplasia were
observed in ACI, but not COP, rats. These strain differences were not because of
differences in circulating E2, progesterone or, prolactin. Two-thirds of the
induced mammary cancers in ACI rats exhibited aneuploidy. The E2-induced mammary
cancers regressed when hormone treatment was discontinued, indicating that they
were estrogen-dependent. Progesterone receptor was expressed by the great
majority of epithelial cells within the E2-induced atypical hyperplastic foci and
the mammary carcinomas, suggesting a link between these lesions. These data
demonstrate a correlation between E2 action in the induction of mammary cell
proliferation and atypical epithelial hyperplasia and genetically conferred
susceptibility to E2-induced mammary cancers.
PMID- 10688908
TI - Expression and function of wingless and frizzled homologs in rheumatoid
arthritis.
AB - Rheumatoid arthritis (RA) is accompanied by synovial inflammation, proliferation,
and cartilage destruction. The reasons the activation of synovial fibroblasts
often persists despite antiinflammatory therapy are not known. One possibility is
that the synovial membrane becomes gradually repopulated with immature
mesenchymal and bone marrow cells with altered properties. To explore this
hypothesis, we have investigated the expression in RA synovial tissues of various
embryonic growth factors from the wingless (wnt) and frizzled (fz) families,
which have been implicated in cell-fate determination in both bone marrow
progenitors and limb-bud mesenchyme. Reverse transcriptase-PCR analysis revealed
expression of five wnt (wnt1, 5a, 10b, 11, and 13) and three fz (fz2, 5, and 7)
isoforms in RA synovial tissues. Osteoarthritis synovial tissues expressed much
less wnt5a and fz5. Northern blotting confirmed the overexpression of wnt5a and
fz5 in RA synovial tissues, in comparison to a panel of normal adult tissues.
Compared with normal synovial fibroblasts, cultured RA fibroblast-like
synoviocytes expressed higher levels of IL-6, IL-8, and IL-15. Transfection of
normal fibroblasts with a wnt5a expression vector reproduced this pattern of
cytokine expression and stimulated IL-15 secretion. These results suggest that
the unusual phenotypic properties of RA fibroblasts may be attributable partly to
their replacement with primitive fibroblast-like synoviocytes with
characteristics of immature bone marrow and mesenchymal cells. Clear delineation
of the signaling pathway(s) initiated by the wnt5a/fz5 ligand-receptor pair in
the RA synovium may yield new targets for therapeutic intervention.
PMID- 10688909
TI - The short interspersed repetitive element of Trypanosoma cruzi, SIRE, is part of
VIPER, an unusual retroelement related to long terminal repeat retrotransposons.
AB - The short interspersed repetitive element (SIRE) of Trypanosoma cruzi was first
detected when comparing the sequences of loci that encode the TcP2beta genes. It
is present in about 1,500-3,000 copies per genome, depending on the strain, and
it is distributed in all chromosomes. An initial analysis of SIRE sequences from
21 genomic fragments allowed us to derive a consensus nucleotide sequence and
structure for the element, consisting of three regions (I, II, and III) each
harboring distinctive features. Analysis of 158 transcribed SIREs demonstrates
that the consensus is highly conserved. The sequences of 51 cDNAs show that SIRE
is included in the 3' end of several mRNAs, always transcribed from the sense
strand, contributing the polyadenylation site in 63% of the cases. This study led
to the characterization of VIPER (vestigial interposed retroelement), a 2,326-bp
long unusual retroelement. VIPER's 5' end is formed by the first 182 bp of SIRE,
whereas its 3' end is formed by the last 220 bp of the element. Both SIRE
moieties are connected by a 1,924-bp-long fragment that carries a unique ORF
encoding a complete reverse transcriptase-RNase H gene whose 15 C-terminal amino
acids derive from codons specified by SIRE's region II. The amino acid sequence
of VIPER's reverse transcriptase-RNase H shares significant homology to that of
long terminal repeat retrotransposons. The fact that SIRE and VIPER sequences are
found only in the T. cruzi genome may be of relevance for studies concerning the
evolution and the genome flexibility of this protozoan parasite.
PMID- 10688910
TI - Differential regulation by multiple promoters of the gene encoding the neuron
restrictive silencer factor.
AB - NRSF/REST is a protein that silences transcription of a number of genes that
contain a DNA element called the neuron-restrictive silencer element (NRSE).
During embryogenesis, REST is expressed ubiquitously in nonneural cells, but is
down-regulated during differentiation of neural progenitors into neurons. REST is
also up-regulated in adult neurons by activity, suggesting a possible role for
the protein in synaptic plasticity. To understand mechanisms that control
expression of REST, we identified and characterized the promoter region of the
mouse REST gene (mREST). A 4.5-kb DNA segment containing three exons (A, B, and
C) that correspond to alternatively spliced 5' untranslated regions (5'UTRs) was
isolated and its DNA sequence was determined. Reverse transcription-PCR analyses
of fibroblasts, astrocytes, and neural progenitors identified variants in which
these exons were spliced to exon D, suggesting that exons A, B, and C may each
have a promoter. Consistent with this hypothesis, primer extension and in vitro
transcription experiments revealed clusters of RNA transcription initiation sites
upstream of exons A, B, and C. Tests of REST/luciferase reporter constructs in
Neuro2A and NIH 3T3 cells revealed promoters upstream of exons A and B that were
active in both cell lines, and a promoter upstream of exon C that was weakly
active only in NIH 3T3 cells. Six enhancer and two repressor regions were found
to overlap each of the three promoters, and some of these were found to be cell
type-specific. Combinatorial arrangements of these promoters with enhancer and
repressor regions may allow modulation of REST expression in particular contexts.
PMID- 10688911
TI - Mammalian thioredoxin reductase: oxidation of the C-terminal
cysteine/selenocysteine active site forms a thioselenide, and replacement of
selenium with sulfur markedly reduces catalytic activity.
AB - Mammalian cytosolic thioredoxin reductase (TrxR) has a redox center, consisting
of Cys(59)/Cys(64) adjacent to the flavin ring of FAD and another center
consisting of Cys(497)/selenocysteine (SeCys)(498) near the C terminus. We now
show that the C-terminal Cys(497)-SH/SeCys(498)-Se(-) of NADPH-reduced enzyme,
after anaerobic dialysis, was converted to a thioselenide on incubation with
excess oxidized Trx (TrxS(2)) or H(2)O(2). The Cys(59)-SH/Cys(64)-SH pair also
was oxidized to a disulfide. At lower concentrations of TrxS(2), the Cys(59)
SH/Cys(64)-SH center was still converted to a disulfide, presumably by reduction
of the thioselenide to Cys(497)-SH/SeCys(498)-Se(-). Specific alkylation of
SeCys(498) completely blocked the TrxS(2)-induced oxidation of Cys(59)-SH/Cys(64)
SH, and the alkylated enzyme had negligible NADPH-disulfide oxidoreductase
activity. The effect of replacing SeCys(498) with Cys was determined by using a
mutant form of human placental TrxR1 expressed in Escherichia coli. The NADPH
disulfide oxidoreductase activity of the purified Cys(497)/Cys(498) mutant enzyme
was 6% or 11% of that of wild-type rat liver TrxR1 with 5, 5'-dithiobis(2
nitrobenzoic acid) or TrxS(2), respectively, as substrate. Disulfide formation
induced by excess TrxS(2) in the mutant form was 12% of that of the wild type.
Thus, SeCys has a critical redox function during the catalytic cycle, which is
performed poorly by Cys.
PMID- 10688912
TI - Selective interaction between leptin and insulin signaling pathways in a hepatic
cell line.
AB - Leptin is a 16-kDa hormone secreted by adipocytes and plays an important role in
control of feeding behavior and energy expenditure. In obesity, circulating
levels of leptin and insulin are high because of the presence of increased body
fat mass and insulin resistance. Recent reports have suggested that leptin can
act through some of the components of the insulin signaling cascade, such as
insulin receptor substrates (IRS-1 and IRS-2), phosphatidylinositol 3-kinase (PI
3-kinase), and mitogen-activated protein kinase, and can modify insulin-induced
changes in gene expression in vitro and in vivo. Well differentiated hepatoma
cells (Fao) possess both the long and short forms of the leptin receptor and
respond to leptin with a stimulation of c-fos gene expression. In Fao cells,
leptin alone had no effects on the insulin signaling pathway, but leptin
pretreatment transiently enhanced insulin-induced tyrosine phosphorylation and PI
3-kinase binding to IRS-1, while producing an inhibition of tyrosine
phosphorylation and PI 3-kinase binding to IRS-2. Leptin alone also induced
serine phosphorylation of Akt and glycogen synthase kinase 3 but to a lesser
extent than insulin, and the combination of these hormones was not additive.
These results suggest complex interactions between the leptin and insulin
signaling pathways that can potentially lead to differential modification of the
metabolic and mitotic effects of insulin exerted through IRS-1 and IRS-2 and the
downstream kinases that they activate.
PMID- 10688913
TI - Recombinant adeno-associated virus type 2, 4, and 5 vectors: transduction of
variant cell types and regions in the mammalian central nervous system.
AB - Recombinant adeno-associated virus vectors based on serotype 2 (rAAV2) can direct
transgene expression in the central nervous system (CNS), but it is not known how
other rAAV serotypes perform as CNS gene transfer vectors. Serotypes 4 and 5 are
distinct from rAAV2 and from each other in their capsid regions, suggesting that
they may direct binding and entry into different cell types. In this study, we
examined the tropisms and transduction efficiencies of beta-galactosidase
encoding vectors made from rAAV4 and rAAV5 compared with similarly designed rAAV2
based vectors. Injection of rAAV5 beta-galactosidase (betagal) or rAAV4betagal
into the lateral ventricle resulted in stable transduction of ependymal cells,
with approximately 10-fold more positive cells than in mice injected with
rAAV2betagal. Major differences between the three vectors were revealed upon
striatal injections. Intrastriatal injection of rAAV4betagal resulted again in
striking ependyma-specific expression of transgene, with a notable absence of
transduced cells in the parenchyma. rAAV2betagal and rAAV5betagal intrastriatal
injections led to beta-gal-positive parenchymal cells, but, unlike rAAV2betagal,
rAAV5betagal transduced both neurons and astrocytes. The number of transgene
positive cells in rAAV5betagal-injected brains was 130 and 5,000 times higher
than in rAAV2betagal-injected brains at 3 and 15 wk, respectively. Moreover,
transgene-positive cells were widely dispersed throughout the injected hemisphere
in rAAV5betagal-transduced animals. Together, our data provide in vivo support
for earlier in vitro work, suggesting that rAAV4 and rAAV5 gain cell entry by
means of receptors distinct from rAAV2. These differences could be exploited to
improve gene therapy for CNS disorders.
PMID- 10688914
TI - Posttranscriptional regulation of Bruton's tyrosine kinase expression in antigen
receptor-stimulated splenic B cells.
AB - Mutation of Bruton's tyrosine kinase (Btk) causes human X-linked
agammaglobulinemia and murine X-linked immunodeficiency syndrome (xid).
Quantitative aspects of B lymphocyte development and function have been
demonstrated to depend on Btk level in vivo by using a murine transgenic model
system. A sensitive intracellular immunofluorescent assay was developed to
measure Btk protein on a per cell basis to test the hypothesis that its dosage is
dynamically regulated during B cell development or functional responses. Marrow
derived hematopoietic stem cells, common lymphoid progenitor cells, and
developing B and myeloid lineages expressed Btk protein at comparable levels.
Resting peripheral B lineage cells had a significantly lower amount of Btk than
marrow-derived cells in both wild-type and xid mice. Activation of the B cell
antigen receptor up-regulated Btk protein level 10-fold within several hours by a
phosphatidylinositol 3-kinase-dependent, posttranscriptional mechanism. In
contrast, the protein level of Btk R28C in activated B lymphocytes from xid mice
remained low. Bypass of the antigen receptor signaling pathways by treatment of
cells with phorbol myristic acid and ionomycin rescued up-regulation of Btk
protein in xid splenic B cells. These combined results suggest that certain
receptor signals mediated by Btk regulate the level of expression of Btk protein
in responding B lymphocytes to potentiate signal transduction. Dynamic regulation
of Btk protein dosage is an additional mechanism to modulate B lymphocyte immune
functions.
PMID- 10688915
TI - Identification of CDK4 as a target of c-MYC.
AB - The prototypic oncogene c-MYC encodes a transcription factor that can drive
proliferation by promoting cell-cycle reentry. However, the mechanisms through
which c-MYC achieves these effects have been unclear. Using serial analysis of
gene expression, we have identified the cyclin-dependent kinase 4 (CDK4) gene as
a transcriptional target of c-MYC. c-MYC induced a rapid increase in CDK4 mRNA
levels through four highly conserved c-MYC binding sites within the CDK4
promoter. Cell-cycle progression is delayed in c-MYC-deficient RAT1 cells, and
this delay was associated with a defect in CDK4 induction. Ectopic expression of
CDK4 in these cells partially alleviated the growth defect. Thus, CDK4 provides a
direct link between the oncogenic effects of c-MYC and cell-cycle regulation.
PMID- 10688916
TI - Chip interacts with diverse homeodomain proteins and potentiates bicoid activity
in vivo.
AB - The Drosophila protein Chip potentiates activation by several enhancers and is
required for embryonic segmentation. Chip and its mammalian homologs interact
with and promote dimerization of nuclear LIM proteins. No known Drosophila LIM
proteins, however, are required for segmentation, nor for expression of most
genes known to be regulated by Chip. Here we show that Chip also interacts with
diverse homeodomain proteins using residues distinct from those that interact
with LIM proteins, and that Chip potentiates activity of one of these homeodomain
proteins in Drosophila embryos and in yeast. These and other observations help
explain the roles of Chip in segmentation and suggest a model to explain how Chip
potentiates activation by diverse enhancers.
PMID- 10688917
TI - Activation of antitumor cytotoxic T lymphocytes by fusions of human dendritic
cells and breast carcinoma cells.
AB - We have reported that fusions of murine dendritic cells (DCs) and murine
carcinoma cells reverse unresponsiveness to tumor-associated antigens and induce
the rejection of established metastases. In the present study, fusions were
generated with primary human breast carcinoma cells and autologous DCs. Fusion
cells coexpressed tumor-associated antigens and DC-derived costimulatory
molecules. The fusion cells also retained the functional potency of DCs and
stimulated autologous T cell proliferation. Significantly, the results show that
autologous T cells are primed by the fusion cells to induce MHC class I-dependent
lysis of autologous breast tumor cells. These findings demonstrate that fusions
of human breast cancer cells and DCs activate T cell responses against autologous
tumors.
PMID- 10688919
TI - Serotonergic control of developmental plasticity.
PMID- 10688920
TI - Building a comprehensive, evidence based tobacco treatment system in managed care
PMID- 10688918
TI - Physical association of ubiquitin ligases and the 26S proteasome.
AB - The ubiquitin (Ub) system recognizes degradation signals of the target proteins
through the E3 components of E3-E2 Ub ligases. A targeted substrate bears a
covalently linked multi-Ub chain and is degraded by the ATP-dependent 26S
proteasome, which consists of the 20S core protease and two 19S particles. The
latter mediate the binding and unfolding of a substrate protein before its
transfer to the interior of the 20S core. It is unclear how a targeted substrate
is delivered to the 26S proteasome, inasmuch as Rpn10p, the only known
proteasomal subunit that binds multi-Ub chains, has been found to be not
essential for degradation of many proteins in the yeast Saccharomyces cerevisiae.
Here we show that Ubr1p and Ufd4p, the E3 components of two distinct Ub ligases,
directly interact with the 26S proteasome. Specifically, Ubr1p is shown to bind
to the Rpn2p, Rpt1p, and Rpt6p proteins of the 19S particle, and Ufd4p is shown
to bind to Rpt6p. These and related results suggest that a substrate-bound Ub
ligase participates in the delivery of substrates to the proteasome, because of
affinity between the ligase's E3 component and specific proteins of the 19S
particle.
PMID- 10688921
TI - Addressing tobacco in managed care conference
PMID- 10688922
TI - Tobacco dependence treatment: scientific challenges; public health opportunities.
PMID- 10688923
TI - Best practices for comprehensive tobacco control programs: opportunities for
managed care organisations.
PMID- 10688924
TI - A proactive health plan: taking action on tobacco control.
PMID- 10688925
TI - Managed care and the state tobacco settlements.
PMID- 10688926
TI - Implementing tobacco interventions in the real world of managed care.
PMID- 10688927
TI - Designing tobacco control systems and cessation benefits in managed care: skill
building workshop.
PMID- 10688928
TI - Tobacco cessation program implementation-from plans to reality: skill building
workshop-group model.
PMID- 10688929
TI - Tobacco cessation program implementation-from plans to reality: skill building
workshop-network model.
PMID- 10688930
TI - Incentivising, facilitating, and implementing an office tobacco cessation system.
PMID- 10688931
TI - Implementing tobacco tracking codes in an individual practice association or a
network model health maintenance organisation.
PMID- 10688932
TI - How a real time clinical data retrieval system might be applied to a tobacco
cessation program.
PMID- 10688933
TI - Findings from the Addressing Tobacco in Managed Care focus groups: an executive
summary.
PMID- 10688934
TI - I. Tailored communications for smoking cessation. Introduction.
PMID- 10688935
TI - Facilitating smoking cessation in cancer patients.
PMID- 10688936
TI - Tailoring tobacco control messages for Hispanic populations.
PMID- 10688937
TI - Communicating with teens: some lessons from commercial marketing.
PMID- 10688938
TI - Computer tailored intervention for older smokers using transdermal nicotine.
PMID- 10688939
TI - II. Smoking cessation in the hospital setting-a new opportunity for managed care.
Introduction.
PMID- 10688940
TI - Hospitalised smokers: characteristics, treatment, and transition to ambulatory
care.
PMID- 10688941
TI - Smoking cessation interventions for patients with heart disease.
PMID- 10688942
TI - III. Maternal smoking cessation: a cost effective strategy for managed care.
Introduction.
PMID- 10688943
TI - Prenatal smoking intervention in managed care settings: the Kaiser Permanente
Southern California prenatal smoking project.
PMID- 10688944
TI - Counselling smokers in Medicaid maternity care: the SCRIPT project.
PMID- 10688945
TI - Pre- and postnatal smoking intervention in managed care settings.
PMID- 10688946
TI - Prenatal smoking cessation strategies in managed care.
PMID- 10688947
TI - Minnesota Decides: a community blueprint for tobacco reduction.
PMID- 10688948
TI - Strategic partnerships for addressing tobacco use.
PMID- 10688949
TI - Addressing Tobacco in Managed Care program.
PMID- 10688950
TI - Smoking cessation clinical practice guideline update and Agency for Healthcare
Research and Quality tobacco resources.
PMID- 10688951
TI - Resources on tobacco prevention and control available to managed care
organisations from the Centers for Disease Control and Prevention.
PMID- 10688952
TI - Tobacco control research in managed care: opportunities at the National Cancer
Institute.
PMID- 10688953
TI - Editorial
PMID- 10688954
TI - Lumbar segmental 'instability': clinical presentation and specific stabilizing
exercise management.
AB - Lumbar segmental instability is considered to represent a significant sub-group
within the chronic low back pain population. This condition has a unique clinical
presentation that displays its symptoms and movement dysfunction within the
neutral zone of the motion segment. The loosening of the motion segment secondary
to injury and associated dysfunction of the local muscle system renders it
biomechanically vulnerable in the neutral zone. The clinical diagnosis of this
chronic low back pain condition is based on the report of pain and the
observation of movement dysfunction within the neutral zone and the associated
finding of excessive intervertebral motion at the symptomatic level. Four
different clinical patterns are described based on the directional nature of the
injury and the manifestation of the patient's symptoms and motor dysfunction. A
specific stabilizing exercise intervention based on a motor learning model is
proposed and evidence for the efficacy of the approach provided.
PMID- 10688955
TI - Inter-examiner and intra-examiner agreement for assessing sacroiliac anatomical
landmarks using palpation and observation: pilot study.
AB - Despite the paucity of research into the reliability of static palpation, it is
still employed extensively as a diagnostic tool by manual medicine practitioners.
This study tested the inter- and intra-examiner agreement of ten senior
osteopathic students using static palpation on ten asymptomatic subjects. Four
assessments of the posterior superior iliac spine (PSIS), sacral sulcus (SS), and
the sacral inferior lateral angle (SILA) on every subject by all examiners
resulted in 1200 assessments in total. Kappa (Kg) yielded intra-examiner
agreement that ranged between less-than-chance to substantial for the SILA (Kg=
0.05 to 0.69; mean Kg=0.21), and slight to moderate for the PSIS (Kg=0.07 to
0.58; mean Kg=0.33) and the SS (Kg=0.02 to Kg=0.60; mean Kg=0.24), with 50%
significant beyond the 0.05 level. Inter-examiner agreement was slight (PSIS
Kg=0.04; SILA Kg=0.08; SS Kg=0.07) and significant at the 0.01 level. Intra
examiner agreement was greater than inter-examiner agreement, which was
consistent with existing palpation reliability studies. The poor reliability of
clinical tests involving palpation may be partially explained by error in
landmark location.
PMID- 10688956
TI - Measurement of blood flow in the vertebral artery using colour duplex Doppler
ultrasound: establishment of the reliability of selected parameters.
AB - This study was designed to determine the reliability of the ultrasound testing
procedure for evaluating vertebral artery blood flow, and to determine a robust
testing protocol for future studies. Blood flow parameters were tested in ten
asymptomatic subjects (mean age 33 years, standard deviation 6 years 8 months)
using colour duplex Doppler imaging. Volume flow rate data at C5-6 demonstrated
good reliability from a single measurement (Intraclass correlation coefficient
[ICC]=0.81). Peak velocity sampled at C1-2 showed poor reliability if a single
measurement was used (ICC=0.26) improving to fair levels with three measurements
(ICC=0.77). Reliability for this parameter was good if five measurements were
taken (ICC=0.83-0.84). Systolic/diastolic ratio measured at C5-6 showed poor
reliability (ICC=0.57) if a single measurement was taken in the manner of Thiel
et al. (1994). This improved to fair reliability (ICC=0.75) if the mean of three
measurements was used. There was no further improvement if five measures were
sampled. Sampling at C2-3 in the manner of Refshauge (1994) was found to be
technically difficult and it was not possible to detect a Doppler shift in three
of the ten subjects at this level. Reliability of peak velocity at C2-3 was found
to be poor, regardless of whether single or multiple averaged measurements were
taken (ICC=0.37-0.63). Mean (time averaged) velocity measurements at C2-3 showed
poor reliability if a single measurement was taken (ICC=0.39), fair reliability
if the first three measurements were averaged (ICC=0.73) and good to high
reliability levels if five measurements were sampled (ICC=0.88-0.91). A review of
the literature suggests that sampling volume flow rate at C5-6 and peak velocity
at C1-2 represents a clinically meaningful combination of parameters to detect
narrowing in the VA. The results of this current study indicate the desirability
of taking a single measurement of volume flow rate at C5-6 and the mean of three
measurements of peak velocity at C1-2, with the additional calculation of the
standard error of measurement, if reliable results are to be achieved.
PMID- 10688957
TI - Clinical tests of the sacroiliac joint. A systematic methodological review. Part
1: Reliability.
AB - In the literature concerning the sacroiliac joint (SIJ) there are numerous
specific tests used to detect joint mobility or pain provocation. In this article
the authors have reviewed 11 studies which investigated the reliability of these
tests. The methodological quality of the studies was tested by a list of criteria
developed by the authors. This list consisted of three categories: (1) study
population, (2) test procedures and (3) test results. To each criterion a
weighting was attached. The methodological score for nine out of the 11 studies
was found to be acceptable. The results of this review, however, could not
demonstrate reliable outcomes and therefore no evidence on which to base
acceptance of mobility tests of the SIJ into daily clinical practice. There are
no indications that 'upgrading' of methodological quality would have improved the
final conclusions. With respect to pain provocation tests, the findings did not
show the same trend. Two studies demonstrated reliable results using the Gaenslen
test and the Thigh thrust test. One study showed acceptable reliability for five
other pain provocation tests; however, since other authors have described
contradictory results, there is a necessity for further research in this area
with an emphasis on multiple test scores and pain provocation tests of the SIJ.
PMID- 10688958
TI - Professional issue. Guidance for pre-manipulative testing of the cervical spine.
PMID- 10688959
TI - Case report. Clinical instability of the upper cervical spine.
PMID- 10688960
TI - Bibliography
PMID- 10688961
TI - Hypothalamic neuropeptide Y levels in weaning offspring of low-protein
malnourished mother rats.
AB - Maternal low-protein malnutrition during gestation and lactation (LP) is an
animal model frequently used for the investigation of long-term deleterious
consequences of perinatal growth retardation. Hypothalamic neuropeptides are
decisively involved in the central nervous regulation of body weight and
metabolism. We investigated neuropeptide Y (NPY) in distinct hypothalamic nuclei
in the offspring of LP mother rats at the end of the critical hypothalamic
differentiation period (20th day of life). Weanling LP offspring were underweight
(P< 0.001) and hypoinsulinaemic (P< 0.05), while leptin levels were unchanged.
NPY was significantly increased in the paraventricular hypothalamic nucleus (PVN)
(P< 0.01) and lateral hypothalamic area (P< 0.05) in LP offspring. In contrast,
NPY was unchanged in the ventromedial hypothalamic nucleus (VMN). These
observations indicate a leptin-independent stimulation of the orexigenic ARC-PVN
axis in undernourished LP rats at weaning. Furthermore a disturbed NPYergic
regulation of the VMN is suggested, possibly contributing to alterations of the
hypothalamic regulation of body weight and metabolism in LP offspring during
life.
PMID- 10688962
TI - Cerebellin stimulates the secretory activity of the rat adrenal gland: in vitro
and in vivo studies.
AB - Cerebellin is a 16-aminoacid peptide widely distributed in the central nervous
system, where it exerts neuromodulatory functions. Cerebellin is contained in
human adrenal medulla, and it has been recently demonstrated that cerebellin
elicits catecholamine release by human adrenal in vitro. Aim of the present study
was to ascertain whether cerebellin affects adrenal function in the rat.
Cerebellin concentration-dependently (from 10(-9)to 10(-7)M) increased
norepinephrine (but not epinephrine) and cyclic-AMP production by adrenomedullary
tissue in vitro. The norepinephrine response to 10(-7)M cerebellin was blocked by
the protein kinase (PK) A inhibitor H-89, but not by the phospholipase C
inhibitor U-73122 or the PKC inhibitor calphostin-C. Cerebellin did not affect
aldosterone and corticosterone secretion of dispersed zona glomerulosa and zona
fasciculata-reticularis adrenocortical cells. Cerebellin concentration
dependently (from 10(-8)to 10(-7)M) enhanced norepinephrine release by in situ
perfused rat adrenals. Cerebellin (10(-7)M) also elicited a significant rise in
aldosterone and corticosterone output, and this effect was annulled by either the
beta1-adrenoceptor antagonist l -alprenolol or H-89. Collectively, the present
findings allow us to conclude that cerebellin 1) directly stimulates
norepinephrine release via the adenylate cyclase/PKA-dependent signaling pathway;
and 2) indirectly enhances adrenocortical secretion in vivo, through a paracrine
mechanism involving medullary catecholamine release.
PMID- 10688963
TI - Tachykinins play a minor role in mediating the third phase of the contractile
response to vagal nerve stimulation of the guinea-pig oesophagus.
AB - The aim of this study was to determine whether tachykinin receptors might be
involved in the mediation of the atropine- and capsaicin-sensitive third phase of
a triphasic contractile response to vagal nerve stimulation of the guinea-pig
isolated oesophagus. The third phase was inhibited 23.3 +/- 1.7% (P< 0.001, n =
5) and 30. 8 +/- 9.0% (P< 0.05, n = 5) by the NK(3)receptor antagonist, SR 142
801 (0.1 and 1 microM respectively). SR 142 801 (0.1 and 1 microM) had no
significant effect on the response to a submaximal concentration of acetylcholine
(0.1 mM, n = 4). The third phase was not significantly affected by NK(1)or
NK(2)receptor antagonists. Thus, in the guinea-pig oesophagus, it appears that
while NK(1)and NK(2)receptors are not involved, NK(3)receptors play a minor role
in mediating a contractile response when afferent neurones are excited by vagal
nerve stimulation.
PMID- 10688964
TI - Cerebrospinal fluid somatostatin levels in febrile seizures and epilepsy in
children.
AB - We analysed the level of cerebrospinal fluid (CSF) somatostatin in children with
febrile seizures and epilepsy. In the febrile seizure group (n = 23), the
somatostatin level was 83.9 +/- 11.2 pg/ml, which was significantly higher than
that of age-matched controls. CSF samples obtained within 3 h of the last seizure
had higher somatostatin levels (106.1 +/- 12.4 pg/ml;n = 14) than did the CSF
obtained after 3 h (49.4 +/- 15.6 pg/ml;n = 9). The mean somatostatin level in
the epilepsy group was 35.3 +/- 4.3 pg/ml (n = 34), and was distributed as
follows: 27.6 +/- 3.6 pg/ml in the idiopathic generalized epilepsy group (n =
16), 44.0 +/- 9.4 pg/ml in the symptomatic generalized epilepsy group (n = 13),
and 37.2 +/- 10.1 pg/ml in the partial epilepsy group (n = 5). The levels in each
group were significantly higher than those in age-matched controls. Somatostatin
is a hypothalamic tetradecapeptide with excitatory effects on neurons in children
with febrile seizures and epilepsy. The finding that patients with convulsive
disease had elevated levels of CSF somatostatin suggests that somatostatin
release is somehow related to seizure activity. It remains to be determined
whether this is due to increased release from over-active excitatory neurons or
leakage from damaged or anoxic neurons, secondary to seizure activity.
PMID- 10688965
TI - Role of third intracellular loop of galanin receptor type 1 in signal
transduction.
AB - To determine the domains essential for G-protein coupling of the human galanin
receptor type 1 (GalR1), we have used both GalR1 mutants and synthetic receptor
derived peptides in(125)I-galanin and [(35)S]-GTPgammaS binding studies.
Replacement of potential phosphorylation sites by Leu in the third intracellular
loop (IC3) of GalR1 did not affect K(D)values for the receptor. Peptides derived
form the IC3 loop, and especially the N-terminal part of it were able to increase
the rate of [(35)S]-GTPgammaS binding to the trimeric Gialpha1beta1gamma2, but
not to Gsalphabeta1gamma2, whereas the peptides corresponding to the IC1 and IC2
loops had no such effect. IC3 loop peptides also inhibited the binding of(125)I
galanin to GalR1 in membranes from Rin m5F cells. Our results suggest that the
IC3 loop of GalR1, especially its N-terminal part, defines the coupling of the
receptor to the Gialpha1beta1gamma2 protein and consequently, to the signal
transduction cascade.
PMID- 10688966
TI - Peripheral distribution and gene expression of adrenomedullin in the rat:
possible source of blood adrenomedullin.
AB - Adrenomedullin (AM) was detected in all tissues examined with the highest
concentrations in adrenal gland, lung and cardiac atrium. High concentrations of
pre-proadrenomedullin mRNA were also detected in the lung, cardiac atrium,
adrenal gland, thoracic aorta and mesenteric artery for the first time by
solution-hybridization-RNase protection assay. The molecular forms of rat AM in
various tissues and plasma were also characterized by Biogel P(30)gel filtration
chromatography. We found no significant difference in immunoreactive AM levels
between the veins draining the kidney, the lung and the adrenal and the systemic
arterial blood. The very low peptide/mRNA ratio and the AM/precursor ratio in the
mesenteric artery and thoracic aorta suggest that blood vessels may be the main
source of plasma AM.
PMID- 10688967
TI - Effects of TRH on acoustic startle, conditioned fear and active avoidance in
rats.
AB - The effects of intracerebroventricular injection of thyrotropine-releasing
hormone (TRH) on acoustic startle, conditioned fear and active avoidance were
examined in rats. Acoustic startle was significantly depressed by 12.5 microg
TRH, while increasing motor activity. In a fear-potentiated startle paradigm,
12.5 microg TRH reduced the overall startle response amplitude, but did not
decrease the amount of fear-potentiated startle. When TRH was administered 15 min
before contextual fear conditioning, neither fear-related freezing in acquisition
nor in a retention test was affected. In contrast, when TRH was administered 15
min before the retention test, TRH significantly reduced mean percentage of time
spent freezing. TRH had no effect on active avoidance. The results demonstrate
that TRH decreased acoustic startle and freezing responses, but had little effect
on fear conditioning and active avoidance. It is suggested that the results may
be due to TRH's effects on motor activity and arousal, independent of its effects
on fear.
PMID- 10688968
TI - Tachykinin activation of human monocytes from patients with interstitial lung
disease, healthy smokers or healthy volunteers.
AB - Three types of tachykinin receptors, NK(1), NK(2)and NK(3), have been described
to preferentially interact with substance P (SP), neurokinin A (NKA) and
neurokinin B (NKB) respectively. Experimental evidence indicates that SP and NKA
modulate the activity of inflammatory and immune cells, including mononuclear
ones, and points to their involvement in lung pathophysiology. We previously
reported that NK(1)and NK(2)receptors are present on monocytes (MO) isolated from
healthy donors or rheumatoid patients - a greater sensitivity to NK(2)receptor
stimulation was observed in the latter condition. This study evaluated the
effects of SP and NKA, as well as NK(1)and NK(2)selective agonists and
antagonists, on MO obtained from healthy volunteers, healthy smokers or patients
with interstitial lung diseases (e.g. sarcoidosis and idiopathic pulmonary
fibrosis). Superoxide anion (O(2)(-)) production was chosen as a parameter of
cell activation. SP and NKA dose-dependently evoked O(2)(-)production from MO in
all the conditions evaluated, their effects being competitively antagonized by
selective antagonists (CP 96 345 and MEN 10 627, respectively). When selective
NK(1)and NK(2)agonists were used, [Sar(9)Met(O(2))(11)]SP, a selective
NK(1)agonist, induced a more than doubled O(2)production in MO obtained from
patients with interstitial lung diseases as compared to healthy volunteers,
whereas MO isolated from healthy volunteers were more sensitive to NK(2)receptor
stimulation.
PMID- 10688969
TI - Modulation of the growth hormone-releasing activity of thyrotropin-releasing
hormone in the chicken by its gene-related peptide preproTRH((160-169))(Ps4):
enhanced somatostatinergic tone?
AB - Recent research demonstrated that endocrine actions of thyrotropin (TSH)
releasing hormone (TRH) are modulated by gene-related products within proTRH. In
the present report we show that the growth hormone (GH) response to TRH is
clearly inhibited after the preincubation of chicken pituitary glands with
preproTRH((160-169))Ps4, whereas the TSH response is not impaired. Binding sites
for(125)I-[Tyr(0)]-Ps4 were, however, not detected on chicken pituitary
membranes, although (as a control) they were readily detectable on membranes from
rat pituitary glands. An indirect action may therefore take place within the
pituitary by modulating the action of somatostatin (SRIH), the inhibitor of GH
release in the chicken. This hypothesis is strengthened by the observation that
Ps4 increases the binding of(125)I-[Tyr(1)]-SRIH to chicken pituitary membranes
in a dose-related way. Since Ps4 is also produced by pituitary tissue, this may
reflect a local or paracrine action on the regulation of GH release.
PMID- 10688970
TI - Neuropeptide Y attenuates the effect of locus coeruleus denervation by DSP-4
treatment on social behaviour in the rat.
AB - Noradrenaline (NA) has been implicated in both increase and reduction of anxiety.
Selective destruction of nerve endings of the locus coeruleus projections by DSP
4 has been shown to reduce active behaviour in novel situations by enhancing
anxiety. In the present study, DSP-4 (50 mg/kg) treatment reduced locomotor
activity and time spent in social interaction in rats placed into a novel
environment together with an unfamiliar rat, indicating an anxiogenic-like
effect. The effect of DSP-4 on time spent in social interaction was completely
antagonized by intracerebroventricular administration of neuropeptide Y (NPY) (1
microg) which had no effect of its own on this measure. The present study thus
supports the idea that DSP-4 pretreatment is anxiogenic in novel situations and
suggests a functional relationship of NA- and NPY-using neural mechanisms in the
regulation of social behaviour.
PMID- 10688971
TI - Modulatory effect of endogenous and exogenous opioids on the excitatory reflex
pathway of the rat ileum.
AB - The ascending excitatory reflex is part of the peristaltic reflex, an important
participant in intestinal propulsion. The aim of this study was to characterize
the role of different opioid receptors in the ascending reflex through exogenous
application of non-selective (Met-enkephalin) and selective opioid agonists (mu
PLO17, delta-DPDPE, kappa-U-50, 488) as well as selective opioid receptor
antagonists (mu: CTOP-NH(2), delta: ICI-174,864, kappa: Nor-Binaltorphimine).
Metenkephalin (IC(50): 0.06 microM) and morphine (IC(50): 1.8 microM) inhibited
the ascending reflex response concentration-dependently. Both the mu-selective
agonist PLO17 (IC(50): 0.83 microM, n =11) and the kappa-selective agonist U
50,488 (IC(50): 0.68 microM, n =8) concentration-dependently inhibited the
magnitude of the ascending contractile reflex response, whereas the delta-agonist
DPDPE (10(-10)-10(-6)M) had no significant effect. In contrast, the latency of
the response (time interval between start of the stimulus and onset of the
contraction) was significantly prolonged by PLO17 > morphine > Met-enkephalin >
DPDPE, whereas U-50,488 showed no effect. When the effect of the receptor
specific antagonists was tested, only CTOP-NH(2)and Nor-BNI caused a significant
increase of the contractile response, whereas ICI-174 864 was ineffective. On the
other hand, CTOP-NH(2)> ICI-174 864 decreased the latency significantly but the
kappa-receptor agonist Nor-BNI had no influence. Thus, mu- and kappa-receptors
seem to be involved in regulating the contraction strength of the ascending
reflex, whereas both mu- and delta-receptors seem to be involved in the timing of
the reflex response.
PMID- 10688972
TI - Mu and delta opioid receptor regulation of pro-opiomelanocortin peptide secretion
from the rat neurointermediate pituitary in vitro.
AB - We investigated the ability of selective opioid agonists and antagonists to
influence pro-opiomelanocortin peptide secretion from the rat neurointermediate
lobe in vitro. The mu-opioid agonist DAMGO ([D-Ala(2), N-Me-Phe(4), Gly(5)
ol]enkephalin) significantly stimulated beta-endorphin and alpha-melanocyte
stimulating hormone release relative to controls early (30 min) in the incubation
period. Similar effects on beta-endorphin secretion were observed with the
selective mu-opioid agonist dermorphin. The delta-opioid receptor agonist DPDPE
([D-Pen(2,5)]enkephalin) weakly inhibited beta-endorphin secretion relative to
controls while the kappa-opioid receptor agonist U50488 had no effect. The mu
opioid selective antagonist CTOP (D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2))
inhibited basal beta-endorphin secretion while kappa- and delta-opioid receptor
antagonists had no effect. Our data support a role for local mu-opioid receptor
control of intermediate lobe pro-opiomelanocortin peptide secretion. Peptide
secretion from melanotropes appears to be tonically stimulated by activation of
mu-opioid receptors in the absence of intact neuronal innervation to the
intermediate lobe.
PMID- 10688973
TI - Opioid activity profiles indicate similarities between the nociceptin/orphanin FQ
and opioid receptors.
AB - Nociceptin (orphanin FQ) is the recently discovered peptide agonist for the
orphan receptor opioid receptor-like 1 (ORL1). Despite the high sequence homology
between ORL1 and the opioid receptors, most opioids lack affinity for the
nociceptin receptor. The affinity and functional profile of opioids possessing
activity at the nociceptin receptor was determined using [3H]nociceptin and
nociceptin-stimulated [35S]GTPgammaS binding. The mu-opioid receptor-selective
agonist lofentanil potently and competitively displaced [3H]nociceptin at rat
brain receptors (IC(50) 62 nM). Lofentanil exhibited full agonism for enhancement
of [35S]GTPgammaS binding to human recombinant ORL1 receptors (EC(50) 50 nM). The
related piperidines ohmefentanyl and sufentanil and the nonselective opioid
receptor agonist etorphine were less potent nociceptin receptor agonists. The
kappa(1)+kappa(3)-opioid receptor agonist/mu-opioid receptor antagonist naloxone
benzoylhydrazone was a pure antagonist at both rat brain and human ORL1
receptors. The nonselective opioid receptor partial agonist buprenorphine and the
nonselective opioid receptor antagonist (-)-quadazocine exhibited pure antagonism
at rat brain receptors, but displayed partial agonism at human ORL1 receptors.
Thus, opioids displaying full agonism at the nociceptin receptor are also opioid
receptor agonists, whereas opioids that are antagonists or partial agonists at
the nociceptin receptor show antagonism or partial agonism at opioid receptors.
In addition, the stereospecificity required at opioid receptors appears to be
retained at the nociceptin receptor, since (+)-quadazocine is inactive at both
receptors. These findings illustrate the structural and functional homology of
the opioid recognition site on these two receptor classes and suggest that
opioids may provide leads for the design of nonpeptide nociceptin receptor
agonists and antagonists lacking affinity for the classical opioid receptors.
PMID- 10688974
TI - Essential role of extracellular charged residues of the human CCK(1) receptor for
interactions with SR 146131, SR 27897 and CCK-8S.
AB - We hypothesized that charge-charge interactions may be important for the binding
of the human cholecystokinin type 1 (CCK(1)) receptor-specific non-peptide full
agonist SR 146131, (2-[4-(4-chloro-2, 5-dimethoxyphenyl)-5-(2-cyclohexyl-ethyl)
thiazol-2-ylcarbamoyl ]-5, 7-dimethyl-indol-1-yl-1-acetic acid), the competitive
antagonist SR 27897, (1-[2-(4-(2-chlorophenyl)thiazol-2-yl) aminocarbonyl indoyl]
acetic acid) and the natural octapeptide CCK-8S to the CCK(1) receptor. Alanine
replacement studies of positively charged residues in the extracellular domains
of the receptor showed that only the R336A mutation affected SR 146131 potency of
mutated receptors transiently expressed in monkey kidney epithelial COS-7 cells.
Two residues, Lys(115) and Lys(187), were implicated in SR 27897 binding. Only
the replacement of Lys(115), Arg(197) and Arg(336) significantly affected CCK-8S
binding or activity. These results clearly indicated the importance of certain
charged residues, but not others, in SR 146131, SR 27897 and CCK-8S binding.
Furthermore, although these molecules probably occupy different binding sites on
the CCK(1) receptor, we show that a small non-peptide agonist, SR 146131, can
stimulate the dual signaling pathways mediated by the CCK(1) receptor.
PMID- 10688975
TI - Activation of multiple mitogen-activated protein kinases by recombinant
calcitonin gene-related peptide receptor.
AB - Calcitonin gene-related peptide is a 37-amino-acid neuropeptide and a potent
vasodilator. Although calcitonin gene-related peptide has been shown to have a
number of effects in a variety of systems, the mechanisms of action and the
intracellular signaling pathways, especially the regulation of mitogen-activated
protien kinase (MAPK) pathway, is not known. In the present study we investigated
the role of calcitonin gene-related peptide in the regulation of MAPKs in human
embryonic kidney (HEK) 293 cells stably transfected with a recombinant porcine
calcitonin gene-related peptide-1 receptor. Calcitonin gene-related peptide
caused a significant dose-dependent increase in cAMP response and the effect was
inhibited by calcitonin gene-related peptide(8-37), the calcitonin gene-related
peptide-receptor antagonist. Calcitonin gene-related peptide also caused a time-
and concentration-dependent increase in extracellular signal-regulated kinase
(ERK) and P38 mitogen-activated protein kinase (P38 MAPK) activities, with
apparently no significant change in cjun-N-terminal kinase (JNK) activity.
Forskolin, a direct activator of adenylyl cyclase also stimulated ERK and P38
activities in these cells suggesting the invovement of cAMP in this process.
Calcitonin gene-related peptide-stimulated ERK and P38 MAPK activities were
inhibited significantly by calcitonin gene-related peptide receptor antagonist,
calcitonin gene-related peptide-(8-37) suggesting the involvement of calcitonin
gene-related peptide-1 receptor. Preincubation of the cells with the cAMP
dependent protein kinase inhibitor, H89 [?N-[2-((p-bromocinnamyl)amino)ethyl]-5
isoquinolinesulfonamide, hydrochloride?] inhibited calcitonin gene-related
peptide-mediated activation of ERK and p38 kinases. On the other hand,
preincubation of the cells with wortmannin ?[1S-(1alpha,6balpha,9abeta,11alpha,
11bbeta)]-11-(acetyloxy)-1,6b,7,8,9a,10,11, 11b-octahydro-1-(methoxymethyl)
9a,11b-dimethyl-3H-furo[4,3, 2-de]indeno[4,5-h]-2-benzopyran-3,6,9-trione?, a PI3
kinase inhibitor, attenuated only calcitonin gene-related peptide-induced ERK and
not P38 MAPK activation. Thus, these data suggest that activation of ERK by
calcitonin gene-related peptide involves a H89-sensitive protein kinase A and a
wortmannin-sensitive PI3-kinase while activation of p38 MAPK by calcitonin gene
related peptide involves only the H89 sensitive pathway and is independent of PI3
kinase. This also suggests that although both ERK and P38 can be activated by
protein kinase A, the distal signaling components to protein kinase A in the
activation of these two kinases (ERK and P38) are different.
PMID- 10688976
TI - The effect of protein kinase C activation on colonic epithelial cellular
integrity.
AB - We have investigated whether activation of protein kinase C has a direct
cytotoxic effect on colonic mucosal epithelial cells and whether oxidant-induced
damage to colonocytes is mediated by activation of cellular protein kinase C.
Incubation of freshly harvested cells from rat colon with the protein kinase C
activator, phorbol 12-myristate, resulted in a concentration-dependent increase
in the extent of cell injury. Phorbol 12-myristate acetate (0.1-10 microM) also
increased cellular protein kinase C activity and this was reduced significantly
by treating cells with the antagonists staurosporine or 2-[1-(3
dimethylaminopropyl)-indol-3-yl]3-(-indol-3-yl)maleimide (GF 109203X; 10 microM).
Phorbol 12-myristate acetate treatment also resulted in increased translocation
of proteins for protein kinase C isoforms alpha, delta and epsilon from cytosol
to membrane particulate fractions. The antagonists reduced the extent of cell
damage in response to phorbol 12-myristate acetate. Furthermore, cell injury in
response to the phorbol acetate was also inhibited by the addition of the oxidant
scavengers, superoxide dismutase or catalase to the cell suspension. Addition of
H(2)O(2) to the incubation medium (0.1-100 microM) resulted in an increase in
cellular protein kinase C activity, an increase in the expression of the alpha,
beta and zeta isoforms and a reduction in cell integrity. The cellular damaging
actions of H(2)O(2) were significantly reduced by the protein kinase C
antagonists, staurosporine or 2-[1-(3-dimethylaminopropyl)-indol-3-yl]-3-(-indol
3-yl)maleimide (GF 109203X). These findings suggest that protein kinase C
activation results in colonic cellular injury and this damage is mediated, at
least in part, by release of reactive oxidants. Furthermore, oxidant-mediated
damage to these cells also involves protein kinase C activation.
PMID- 10688977
TI - Cellular uptake and interaction with purified membranes of rebeccamycin
derivatives.
AB - Rebeccamycin is an antitumor antibiotic possessing a DNA-intercalating
indolocarbazole chromophore linked to a glycosyl residue. The carbohydrate moiety
of rebeccamycin and related synthetic analogues, such as the potent antitumor
drug NB-506 (6-N-formylamino-12,13-dihydro-1, 11-dihydroxy-13-(beta-D
glucopyranosyl)-5H-indolo[2,3-a]pyrrolo- [3,4-c]carbazole-5,7-(6H)-dione), is a
key element for both DNA-binding and inhibition of DNA topoisomerase I. In this
study, we have investigated the cellular uptake of rebeccamycin derivatives and
their interaction with purified membranes. The transport of radiolabeled
[3H]dechlorinated rebeccamycin was studied using the human leukemia HL60 and
melanoma B16 cell lines as well as two murine leukemia cell lines sensitive
(P388) or resistant (P388CPT5) to camptothecin. In all cases, the uptake is rapid
but limited to about 6% of the drug molecules. In HL60 cells, the uptake entered
a steady-state phase of intracellular accumulation of about 0.26+/-0.05
pmol/10(6) cells, which persisted to at least 90 min. The efflux of exchangeable
radiolabeled molecules was relatively weak. Fluorescence studies were performed
to compare the interaction of a rebeccamycin derivative and its aglycone with
membranes purified from HL60 cells. The glycosylated drug molecules bound to the
cell membranes can be extracted upon washing with buffer or by adding an excess
of DNA. In contrast, the indolocarbazole drug lacking the carbohydrate domain
remains tightly bound to the membranes with very little or no exchange upon the
addition of DNA. The membrane transport and binding properties of indolocarbazole
drugs related to rebeccamycin are reminiscent to those of other DNA-intercalating
antitumor agents. The uptake most likely occurs via a passive diffusion through
the plasma membranes and the glycosyl residue of the drug plays an essential role
for the translocation of the drug from the membranes to the internal cell
components, such as DNA.
PMID- 10688978
TI - Region-specific changes in 5-HT(1A) receptor-activated G-proteins in rat brain
following chronic buspirone.
AB - 5-Hydroxytryptamine(1A) (5-HT(1A)) receptors, which activate inhibitory G
proteins, are implicated in psychiatric disorders including anxiety and
depression. Studies suggest that chronic 5-HT(1A) receptor agonist administration
alters 5-HT(1A) receptor function, but the effect of chronic treatment on 5
HT(1A) receptor-activated G-proteins is unclear. In this study, agonist
stimulated [35S]guanylyl-5'-O-(gamma-thio)-triphosphate (GTPgammaS) binding was
examined following chronic administration of buspirone. Brains were processed for
[35S]GTPgammaS autoradiography using R(+)-8-hydroxy-2-(di-n-propylamino)tetralin
(8-OH-DPAT) for 5-HT(1A) receptors or baclofen for GABA(B) receptors. Net 8-OH
DPAT-stimulated [35S]GTPgammaS binding was decreased by 25-30% in the septum and
dorsal raphe nucleus of buspirone-treated animals. No significant changes in 8-OH
DPAT-stimulated [35S]GTPgammaS binding were found in the prefrontal, entorhinal
or cingulate cortices or hippocampus in buspirone-treated rats. GABA(B) receptor
stimulated [35S]GTPgammaS binding was increased by 25% in the hippocampus, with
no significant changes in any other region examined. These results demonstrate
region-specific alterations in 5-HT(1A) and GABA(B) receptor-activated G-proteins
following chronic buspirone treatment, which may contribute to the clinical
effects of this drug.
PMID- 10688979
TI - 5-hydroxytryptamine interaction with the nicotinic acetylcholine receptor.
AB - The present study examines the interaction of the neurotransmitter 5
hydroxytryptamine (5-HT) with muscle-type nicotinic acetylcholine receptors. 5-HT
inhibits the initial rate of [125I]alpha-bungarotoxin binding to Torpedo
acetylcholine receptor membranes (IC(50)=8.5+/-0.32 mM) and [3H]5-HT can be
photoincorporated into acetylcholine receptor subunits, with labeling of the
alpha-subunit inhibitable by both agonists and competitive antagonists. Within
the agonist-binding domain, [3H]5-HT photoincorporates into alphaTyr(190),
alphaCys(192) and alphaCys(193). Functional studies using the human clonal cell
line TE671/RD, show that 5-HT is a weak inhibitor (IC(50)=1.55+/-0.25 mM) of
acetylcholine receptor activity. In this regard, agonist-response profiles in the
absence and presence of 5-HT indicate a noncompetitive mode of inhibition. In
addition, 5-HT displaces high affinity [3H]thienylcyclohexylpiperidine binding to
the desensitized Torpedo acetylcholine receptor channel (IC(50)=1.61+/-0.07 mM).
Collectively, these results indicate that 5-HT interacts weakly with the agonist
recognition site and inhibits receptor function noncompetitively by binding to
the acetylcholine receptor channel.
PMID- 10688980
TI - Tolerance to morphine at the mu-opioid receptor differentially induced by cAMP
dependent protein kinase activation and morphine.
AB - Human neuroblastoma SH-SY5Y cells express endogenous mu-opioid receptor and
develop cellular tolerance to morphine after prolonged (>/=4 h) treatment with
morphine. Treatment with forskolin (25 microM, 12 h), an adenylyl cyclase
activator, also desensitized mu-opioid receptor response to morphine (10 microM)
by 38% (P<0. 001), which was reversed by the cyclic AMP (cAMP) dependent kinase
inhibitor N-(2-aminoethyl)-5-isoquinolinesulfonamide (H8) (100 microM). Treatment
with both morphine and forskolin appeared to cause an additive effect in
desensitizing mu-opioid receptor. In mu-opioid receptor stably transfected human
embryonic kidney 293 (HEK-mu) cells, morphine treatment produced cAMP
upregulation, yet failed to induce mu-opioid receptor tolerance. However,
treatment with forskolin (25 microM) or 8-bromo-cAMP (1mM) led to profound mu
opioid receptor tolerance, which was reversed by H8. These results demonstrate
that cAMP-dependent kinase activation causes mu-opioid receptor tolerance.
However, morphine-induced mu-opioid receptor tolerance in SH-SY5Y cells is not
mediated by cAMP-dependent kinase activation. In addition, our results indicate
that cAMP-upregulation does not necessarily lead to mu-opioid receptor tolerance.
PMID- 10688981
TI - Inhibitory effect of orally administered donepezil hydrochloride (E2020), a novel
treatment for Alzheimer's disease, on cholinesterase activity in rats.
AB - Donepezil hydrochloride ((+/-)-2-[(1-benzylpiperidin-4-yl)methyl]-5, 6-dimethoxy
indan-1-one monohydrochloride: E2020: donepezil) is a potent and selective
acetylcholinesterase inhibitor developed for the treatment of Alzheimer's
disease. The present experiments were designed to compare the inhibitory effects
of orally administered donepezil and other cholinesterase inhibitors, tacrine (9
amino-1,2, 3,4-tetrahydroacridine hydrochloride), (S)-N-ethyl-3-[(1-dimethyl
amino)ethyl]-N-methyl-phenylcarbamate hydrogentartrate (ENA-713, rivastigmine)
and 3-[1-(phenylmethyl)-4-piperidinyl]-1-(2,3,4, 5-tetrahydro-1H-1-benzazepin-8
yl)-1-propanone fumarate (TAK-147), on the cholinesterase activity in the brain
and plasma of rats. Moreover, in order to validate the cholinesterase inhibition
data, we measured the brain and plasma concentrations of these drugs. Oral
administration of donepezil, tacrine, ENA-713 or TAK-147, caused a dose-dependent
inhibition of brain and plasma cholinesterase activities. The ID(50) values of
these compounds for brain cholinesterase activity were 6.3, 40.5, 7.2 and 26.8
micromol/kg, respectively. On the other hand, the ID(50)170, 9.7 and 51.2
micromol/kg, respectively. Thus, the ratios of the ID(50)4.2, 1.3 and 1.9,
respectively. Brain and plasma concentrations of donepezil, tacrine and TAK-147
increased dose-dependently. The ratios of the concentrations (brain/plasma) of
these compounds were 6.1-8.4 for donepezil, 14.5-54.6 for tacrine and 7.0-20.6
for TAK-147. The values of 50% inhibitory concentration of these drugs in the
brain were 0.42, 3.5 and 1.1 nmol/g, respectively. In contrast, the brain and
plasma concentrations of ENA-713 at all doses, except the two highest doses, were
below the quantification limit. These results suggest that orally administered
donepezil satisfactorily penetrates into the brain and inhibits cholinesterase
there, and that donepezil is a potent and selective inhibitor of brain
cholinesterase in comparison with plasma cholinesterase in vivo.
PMID- 10688982
TI - Cross-tolerance between analgesia produced by xylazine and selective opioid
receptor subtype treatments.
AB - Opioid receptor agonists produce analgesia through multiple systems activated by
stimulation of mu(1), mu(2), delta(1), delta(2) and kappa(1) opioid receptors.
Morphine analgesia is modulated by stimulation of alpha(2) adrenoceptors. To
understand how multiple opioid analgesic systems interact with alpha(2)
adrenoceptor systems, analgesic cross-tolerance between the alpha(2) adrenoceptor
agonist xylazine and opioid receptor agonists was studied using the mouse tail
flick assay. Mice received either xylazine (20 mg/kg, s.c.) or saline (1 ml/kg)
for five days. On day six, mice received a dose of s.c. xylazine, i.c.v. [D
Ala(2),MePhe(4),Gly(ol)(5)]enkephalin (DAMGO), i.t. Tyr-Pro-Trp-Gly-NH(2) (Tyr-W
MIF-1), i.c.v. or i.t. [D-Pen(2),D-Pen(5)]enkephalin (DPDPE), i.t. [D
Ala(2)]deltorphin II (deltorphin II), or s.c. trans-(+/-)-3, 4-dichloro-N-methyl
N-[2-(1-pyrrolidinyl-cyclohexyl] benzeneacetamide (U50,488). Xylazine tolerant
mice required 4. 57-fold more xylazine to elicit the same response as saline
treated animals and showed a 2.55-fold shift in i.c.v. DAMGO and a 3.37-fold
shift in i.c.v. DPDPE antinociception. No cross-tolerance was seen with i.c.v.
deltorphin II, i.t.Tyr-W-MIF-1, i.t. DPDPE, i.t. Tyr-W-MIF-1 or s.c. U50,488.
These results implicate alpha(2) adrenoceptor systems in the modulation of
supraspinal mu(1), and delta(1) opioid analgesic circuitry and raise the
possibility that mu(2), delta(2) or kappa(1) opioid receptor agonists may be
alternated with alpha(2) adrenoceptor agonists to minimize tolerance or treat
opioid-tolerant patients.
PMID- 10688983
TI - Noradrenergic lesion antagonizes desipramine-induced adaptation of NMDA
receptors.
AB - Repeated administration of the tricyclic antidepressant, desipramine, for 28 days
to mice effected a decrease in the potency of glycine to displace [3H]5,7
dichlorokynurenic acid (5,7-DCKA) in mouse cortical homogenates. Pre-treatment
with the noradrenergic neurotoxin DSP-4, while having no effect alone, attenuated
the desipramine-induced effect. The present findings support a norepinephrine
dependent adaptation of the NMDA receptor complex in vivo following chronic
desipramine treatment. The inter-relationship of norepinephrine and glutamate
transmission may provide insight into the mechanism underlying the action of
antidepressant drugs.
PMID- 10688984
TI - Motor effects of (-)-OSU6162 in primates with unilateral 6-hydroxydopamine
lesions.
AB - The effects of the novel compound, (-)-OSU6162 ((S)-(-)-3-methylsulfonylphenyl-1
propylpiperidine), on rotational behavior induced by dopamine receptor agonists
was investigated in common marmosets (Callithrix jacchus) with unilateral 6
hydroxydopamine lesions. (-)-OSU6162 per se displayed no effect on the animals'
behavior. On the other hand, pretreatment with (-)-OSU6162 attenuated rotational
behavior induced by apomorphine (apomorphini hydrochloridum), L-DOPA (3,4
dihydroxyphenylalanine), and the dopamine D2 receptor agonist, quinpirole (trans
(-)-4aR-4,4a, 5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolol[3,4-g]quinoline
hydrochloride), without inducing motor impairment such as akinesia or dystonia.
In addition, treatment with (-)-OSU6162 for 5 consecutive days almost completely
abolished the rotational behavior provoked by apomorphine and produced a
transient subsensitization of such apomorphine-induced effects after it was
discontinued. Moreover, pretreatment with (-)-OSU6162 in two monkeys augmented
the rotational behavior elicited by the dopamine D1 receptor agonists, SKF-81297
(R(+)-6-chloro-7,8,dihydroxy-1-phenyl-2,3,4, 5-tetrahydro-1H-3-benzazepine
hydrobromide) and A-77636 ((-)-(1R, 3S)-3-adamantyl-1-(aminomethyl)-3,4-dihydro
5, 6-dihydroxy-1H-2-benzopyran hydrochloride). The findings indicate that (-)
OSU6162 can exert indirect state-dependent effects that differentially affect
dopamine D1 and dopamine D2 receptor agonist-induced behavior.
PMID- 10688985
TI - Antithrombotic efficacy of RPR208566, a novel factor Xa inhibitor, in a rat model
of carotid artery thrombosis.
AB - Coagulation factor Xa is the sole enzyme responsible for activating the zymogen
prothrombin to thrombin, resulting in fibrin generation, platelet activation, and
subsequent thrombus formation. Our objective was to evaluate the antithrombotic
efficacy of the novel factor Xa inhibitor, 2-(3-carbamimidoyl-benzyl)-3-[(3',
4'dimethoxy-biphenyl-4-carbonyl)-amino]-butyric acid methyl ester
trifluoroacetate (RPR208566), in a well-established rat model of arterial
thrombosis, and to compare the results with those obtained with argatroban and
heparin, direct and indirect inhibitors of thrombin, respectively. Thrombus
formation was initiated by placing a filter paper saturated with FeCl(2) on the
adventia of the carotid artery for 10 min. Time-to-occlusion was measured from
initiation of injury until blood flow reached zero. Formed thrombi were removed
and weighed 60 min after the placement of the filter paper. RPR208566, heparin,
and argatroban dose-dependently increased time-to-occlusion and reduced thrombus
mass. When administered at 500 microgram/kg+50 microgram/kg/min, RPR208566
prolonged time-to-occlusion to 56+/-4 min (vs. 18+/-2 min for vehicle) and
reduced thrombus mass to 3.0+/-0.7 mg (vs. 7.3+/-0.6 mg for vehicle). The highest
doses of argatroban (500 microgram/kg+50 microgram/kg/min) and heparin (300
U/kg+10 U/kg/min) increased time-to-occlusion to the maximum of 60 min and
decreased thrombus mass to 5.5+/-0.8 and 2.6+/-0.3, respectively. The
antithrombotic effects of heparin and argatroban at these doses were associated
with increases in activated partial thromboplastin time of 5.6+/-0.9- and 2.9+/
0.3-fold over baseline, respectively. However, the highest dose of RPR208566
produced a modest 1.3+/-0.1-fold increase in activated partial thromboplastin
time. These results indicate that factor Xa inhibition with compounds such as
RPR208566 may be an attractive mechanism for novel antithrombotic drug therapy.
PMID- 10688986
TI - Effects of nitric oxide-modulating amino acids on coronary vessels: relevance to
sepsis.
AB - Excessive nitric oxide (NO) production in septic shock is thought to contribute
to the associated profound hypotension. Here we show that despite induction of NO
synthase (NOS) in the hearts of endotoxin-treated rats, coronary vascular
responses to the contractile peptide endothelin-1, were not modified. This was
not due to any change in the expression of endothelin receptors. However, when
the substrate for NOS, L-arginine, was added to the perfusate, increases in
coronary perfusion pressure stimulated by endothelin were reduced in hearts from
endotoxin-treated animals compared to those from controls. In addition, L
glutamine, which blocks the generation of L-arginine from intracellular stores,
enhanced the increase in perfusion pressure stimulated by endothelin-1. These
data suggest that L-arginine becomes rate limiting for the production of NO in
the coronary vessels during septic shock. Moreover, it suggests that vascular
reactivity may be modulated positively or negatively by supplementation with the
relevant amino acids.
PMID- 10688987
TI - Electrical and mechanical effects of vasoactive intestinal peptide and pituitary
adenylate cyclase-activating peptide in the rat colon involve different
mechanisms.
AB - This work aimed to study the effects of pituitary adenylate cyclase-activating
peptide (PACAP) and vasoactive intestinal peptide (VIP) on the mechanical and
electrical activity of the circular muscle of the rat colon and the mechanisms
involved in such effects. Spontaneous mechanical activity was studied in vitro in
an organ bath and the membrane potential was recorded using the microelectrode
technique. Both VIP and PACAP (0.1 microM) caused an immediate, sustained and
tetrodotoxin (1 microM)-resistant inhibition of the cyclic spontaneous mechanical
activity and hyperpolarization. The small-conductance Ca(2+)-activated K(+)
channel blocker, apamin (1 microM), did not change the VIP- and PACAP-induced
relaxation but reduced the hyperpolarization induced by PACAP whereas it did not
change that induced by VIP. In contrast, the purinoceptor antagonist, suramin
(100 microM), blocked the hyperpolarization caused by PACAP and VIP but failed to
change their mechanical inhibitory effects. Moreover, the putative PACAP and VIP
receptor antagonists, PACAP-(6-38) and VIP-(10-28), respectively, both 3 microM,
failed to change the effects of either peptide and modified neither the
inhibitory junction potential nor the relaxation induced by electrical-field
stimulation. Thus, these results suggest that the mechanisms mediating relaxation
are not strictly coupled to the mechanisms mediating hyperpolarization. This
could be due to activation of two distinct mechanisms of action after agonist
receptor interaction.
PMID- 10688988
TI - Effects of eicosanoids, neuromediators and bioactive peptides on murine airways.
AB - The effects of several mediators including prostanoids, neuromediators, bioactive
peptides and leukotrienes were investigated on the trachea, upper bronchi, lower
bronchi and lung parenchyma of selected strains of mice mounted in a cascade
superfusion system. The upper airways (trachea, upper bronchi) responded with
greater maxima than lower airways (lower bronchi, lung parenchyma).
Acetylcholine, carbachol, serotonin and 9, 11-dideoxy-9alpha,11alpha-epoxymethano
prostaglandin F(2alpha)serotonin>/=acetylcholine. Prostaglandins E(2), F(2alpha)
and D(2)90% relaxation in some cases. The rank order of potency for the
prostaglandins was E(2)>/=F(2alpha)D(2) with the exception of the lower bronchi
on which prostaglandins had the following order of potency: F(2alpha)>/=E(2)D(2).
The effects of prostaglandins were similar in four commonly used strains of mice
(CD-1, BALB/c, C57BL/c6 and C3H) with some variations in efficacy. Iloprost was a
weak mouse airway relaxant. It had the greatest effect on the trachea and bronchi
of BALB/c and C57BL/c6 mice, whereas it had little or no effect on the airways of
the CD-1 and C3H mouse strains. Vasoactive intestinal peptide potently relaxed
the carbachol and precontracted the mouse trachea and bronchi. However,
vasopressin, another bioactive peptide, potently and efficaciously contracted the
mouse trachea and upper bronchi but had little effect on the lower bronchi.
Vasopressin was the most potent and efficacious contractile agonist tested in
this study. Contractions were observed with endothelins-1, -2 and -3 on mouse
trachea and bronchi, but marked tachyphylaxis was present. Sarafotoxin s6c
followed the same pattern suggesting the presence of endothelin ET(B) receptors
on the mouse airways. Of all leukotrienes assayed (B(4), C(4), D(4) and E(4))
only leukotriene C(4) weakly contracted the mouse trachea and upper bronchi, but
tachyphylaxis was most evident.
PMID- 10688989
TI - Effects of mu-opioid receptor agonists on intestinal secretion and permeability
during acute intestinal inflammation in mice.
AB - We evaluated and compared the effects of mu-opioid receptor agonists on mucosal
fluid transport and permeability, during acute intestinal inflammation. We
hypothesized that inflammation would sensitize mu-opioid receptors in the
submucosal plexus and/or enterocytes enhancing the effects of mu-opioid receptor
agonists. Inflammation was induced by intragastric administration of croton oil,
whereas controls received saline. Fluid transport was assessed by enteropooling,
and intestinal permeability by blood-to-lumen passage of [51Cr]
etylenediaminetetraacetate ([51Cr] EDTA). Intestinal inflammation induced a
significant increase in enteropooling (1.9 times) and permeability (2.5 times).
In saline- and croton oil-treated animals, mu-opioid receptor agonists produced
dose-related inhibitions of enteropooling and intestinal permeability. During
inflammation, the potency of morphine increased 4.8 and 3.7 times, inhibiting
enteropooling and intestinal permeability, respectively; the potencies of
fentanyl and PL017 similarly increased by approximately three (enteropooling) and
two times (permeability) in croton oil animals. All effects were reversed by
naloxone and naloxone methiodide. The results show that inflammation increases
the inhibitory potency of mu-opioid receptor agonists on secretion and
permeability, suggesting a sensitization of peripheral mu-opioid receptors.
PMID- 10688990
TI - Anti-inflammatory glycoterpenoids from Scrophularia auriculata.
AB - The activity of the four glycoterpenoids: two saponins, verbascosaponin A and
verbascosaponin, and two iridoids, scropolioside A and scrovalentinoside,
isolated from Scrophularia auriculata ssp. pseudoauriculata, were studied in
different models of acute and chronic inflammation. Both saponins significantly
inhibited the mouse paw edema induced by carrageenan and ear edema induced by
single and multiple doses of 12-O-tetradecanoylphorbol 13-acetate (TPA).
Verbascosaponin A showed a potency twice as high as that of indomethacin in the
acute TPA model. Verbascosaponin A and scropolioside A were active after a long
latency period against ethyl phenylpropiolate edema, as are glucocorticoids. When
the putative corticoid-like mechanism of the two compounds was studied,
verbascosaponin A activity was notably reduced by the mRNA synthesis inhibitor,
actinomycin D, while the effect of scropolioside A was partially interfered with
by the anti-glucocorticoid drugs used. Both iridoids were active on the delayed
type hypersensitivity reaction. They significantly reduced the inflammatory
lesion and suppressed the cellular infiltration.
PMID- 10688991
TI - (R)-ACX is a novel sufonylurea compound with potent, quick and short-lasting
hypoglycemic activity.
AB - We investigated the mechanism of the hypoglycemic effect of (R)-4-(1
acetoxyethyl)-N-(cyclohexylcarbamoyl)benzene-sulfonamide [(R)-acetoxyhexamide;
(R)-ACX], a new sulfonylurea compound. (R)-ACX potently stimulated the release of
insulin from cultured pancreatic beta-cells (HIT T15 cells), established from
hamster islet cells SV40-transformed. When (R)-ACX was orally administered to
fasted rats, it decreased the plasma glucose level in a dose-dependent manner.
The hypoglycemic effect of (R)-ACX was quick and short lasting, as compared to
that of acetohexamide and glibenclamide. The quick and short-lasting hypoglycemic
effect of (R)-ACX was thought likely to result from rapid absorption of (R)-ACX
and rapid elimination of (R)-ACX and its metabolite, (R)-hydroxyhexamide.
Furthermore, (R)-ACX was found to suppress the increase of blood glucose level
due to starch loading in fasted mice. (R)-ACX may be useful in the control of
postprandial hyperglycemia to patients with non-insulin-dependent diabetic
mellitus.
PMID- 10688992
TI - Male factor subfertility: possible causes and the impact of nutritional factors.
AB - OBJECTIVE: To review possible causes for male factor subfertility with emphasis
on nutritional factors such as zinc and folate. DESIGN: A literature search was
performed on MEDLINE and via bibliographies of published works. RESULT(S): Many
causes for male factor subfertility are described in the literature. Both
environmental and genetic factors could play a role. However, the pathogenesis of
male factor infertility is poorly understood, including the role of specific
micronutrients such as zinc and folate. Both zinc and folate are involved in the
synthesis of DNA and RNA. Despite the fact that zinc deficiency leads to several
clinical symptoms such as decreased spermatogenesis and impaired male fertility,
the exact pathophysiology has not been clarified. CONCLUSION(S): Because most
causes of male factor subfertility are unknown, more research is needed. Because
male factor subfertility due to nutritional deficiencies is in principle amenable
to curative and/or preventive action by supplementation, emphasis should be put
on studies on the effect of specific nutrients on male fertility.
PMID- 10688993
TI - Ethical issues in ovarian transplantation and donation.
PMID- 10688994
TI - On assisted reproduction, religion, and civil law.
PMID- 10688995
TI - Use of frozen-thawed testicular sperm for intracytoplasmic sperm injection.
AB - OBJECTIVE: To determine the feasibility of using frozen-thawed testicular
spermatozoa for intracytoplasmic sperm injection. DESIGN: Prospective clinical
study. SETTING: A university hospital. PATIENT(S): One hundred seventy-five
azoospermic men participating in a routine intracytoplasmic sperm injection
program. INTERVENTION(S): The men underwent testicular biopsy for
cryopreservation of tissue to be used in consecutive intracytoplasmic sperm
injection treatment cycles. Their female partners underwent controlled ovarian
hyperstimulation for conventional IVF treatment. MAIN OUTCOME MEASURE(S):
Fertilization and pregnancy rates. RESULT(S): In 77% of the patients, spermatozoa
could be harvested from the testis by an open testicular biopsy technique and
used for intracytoplasmic sperm injection after freezing and thawing of
testicular tissue. Histopathologic evaluation revealed a Sertoli cell-only
pattern in 21%, maturation arrest in 60%, and hypospermatogenesis in 19% of the
patients. In 2. 9% of the patients, carcinoma in situ or a germ cell tumor was
detected. In all patients, viable spermatozoa could be visualized after the
tissue samples were thawed. One hundred thirty-five intracytoplasmic sperm
injection treatment cycles were performed, with a fertilization rate of 45% and a
clinical pregnancy rate of 30% per oocyte retrieved. CONCLUSION(S): The use of
frozen-thawed testicular tissue allows ovarian stimulation of the female partner
to be timed and avoids cancellation of ovum pick-up when spermatozoa cannot be
retrieved.
PMID- 10688996
TI - Relationship between oxidative stress, semen characteristics, and clinical
diagnosis in men undergoing infertility investigation.
AB - OBJECTIVE: To determine whether particular semen characteristics in various
clinical diagnoses of infertility are associated with high oxidative stress and
whether any group of infertile men is more likely to have high seminal oxidative
stress. Reactive oxygen species (ROS) play an important role in sperm
physiological functions, but elevated levels of ROS or oxidative stress are
related to male infertility. DESIGN: Measurement of sperm concentration,
motility, morphology, seminal ROS, and total antioxidant capacity (TAC) in
patients seeking infertility treatment and controls. SETTING: Male infertility
clinic of a tertiary care center. PATIENT(S): One hundred sixty-seven infertile
patients and 19 controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Semen
characteristics, seminal ROS, and TAC in samples from patients with various
clinical diagnoses and controls. RESULT(S): Fifteen patients (9.0%) were Endtz
positive and 152 (91.0%) Endtz negative. Sperm concentration, motility, and
morphology were significantly reduced in all groups compared with the controls (P
=.02), except in varicocele associated with infection group. Mean (+/-SD) ROS
levels in patient groups ranged from 2.2 +/- 0.13 to 3.2 +/- 0.35, significantly
higher than controls (1.3 +/- 0.3; P<.005). Patient groups had a significantly
lower mean (+/-SD) TAC from 1014.75 +/- 79.22 to 1173.05 +/- 58.07 than controls
(1653 +/- 115.28, P<.001), except in the vasectomy reversal group (1532.02 +/-
74.24). Sperm concentration was negatively correlated with ROS both overall and
within all groups (P=.007), with the exception of idiopathic infertility.
CONCLUSION(S): Irrespective of the clinical diagnosis and semen characteristics,
the presence of seminal oxidative stress in infertile men suggests its role in
the pathophysiology of infertility. Medical or surgical treatments for
infertility in these men should include strategies to reduce oxidative stress.
PMID- 10688997
TI - Relatively poor oocyte quality is an indication for intracytoplasmic sperm
injection.
AB - OBJECTIVE: To determine the relation between the insemination method used and the
quality of oocytes and embryos. DESIGN: Prospective study. SETTING: Assisted
reproductive centers at Yamagata University Hospital and Kuramoto Women's Clinic
in Yamagata, Japan. PATIENT(S): Forty patients undergoing IVF and 40 patients
undergoing intracytoplasmic sperm injection (ICSI). INTERVENTION(S): To estimate
oocyte quality, the granulosa cells surrounding the oocyte were fixed and stained
with a commercial dye in both groups of patients. One thousand granulosa cells
were examined under a fluorescence microscope. MAIN OUTCOME MEASURE(S): The
incidence of apoptotic granulosa cells surrounding each oocyte. RESULT(S): The
incidence of apoptosis in the granulosa cells enclosing the oocytes that were
fertilized by IVF was significantly lower than that in the oocytes that were
fertilized by ICSI. Moreover, the incidence of apoptosis in the granulosa cells
enclosing the oocytes that grew into good-quality or fair-quality embryos was
significantly lower after conventional IVF than after ICSI. With ICSI, the
incidence of apoptosis was not significantly different among the granulosa cells
surrounding the oocytes that were inseminated, were fertilized, or developed into
good-quality or fair-quality embryos. With IVF, the incidence of apoptosis was
highest in the granulosa cells surrounding the oocytes that were inseminated and
lowest in the granulosa cells surrounding the oocytes that developed into good
quality and fair-quality embryos. CONCLUSION(S): A good-quality oocyte is
necessary for the development of a good-quality embryo with IVF but not with
ICSI. Thus, relatively poor oocyte quality is a good indication for the use of
ICSI.
PMID- 10688998
TI - Abnormalities in sperm acid glycosidases from infertile men with idiopathic
oligoasthenoteratozoospermia.
AB - OBJECTIVE: To analyze and compare acid beta-glucuronidase, alpha-mannosidase,
alpha-glycosidase, alpha-galactosidase, beta-galactosidase, and beta-N
acetylglucosaminidase activities in fertile and infertile patients. DESIGN: An
observational, controlled, clinical study. SETTING: A university tertiary
hospital. PATIENT(S): Thirty-six fertile controls, 24 infertile
oligoasthenoteratozoospermic (OAT) patients, and 10 azoospermic patients, who
served as negative controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S):
Analysis of the six glycosidase activities in seminal plasma and in solubilized
spermatozoa. RESULT(S): alpha-galactosidase and beta-galactosidase activities in
spermatozoa were significantly correlated with the serum levels of gonadotropins
both in fertile controls and in OAT patients. The relative contribution of alpha
galactosidase and beta-galactosidase from the soluble fraction of spermatozoa to
the total activity measured in the ejaculate of OAT patients was significantly
lower than in fertile controls. The activities of beta-galactosidase and beta-N
acetylglucosaminidase in the soluble fraction of spermatozoa from OAT patients
were significantly lower than in fertile controls. In seminal plasma, the
activity of alpha-mannosidase from OAT patients was significantly higher than in
fertile controls. The activity of beta-N-acetylglucosaminidase in the nonsoluble
fraction of spermatozoa from OAT patients was three times higher than in fertile
controls. CONCLUSION(S): The abnormalities in the distributions and contents of
alpha-galactosidase, beta-galactosidase, and beta-N-acetylglucosaminidase in
sperm suggest possible functional defects in spermatozoa from OAT infertile
patients.
PMID- 10688999
TI - Human oviductal cells produce a factor(s) that maintains the motility of human
spermatozoa in vitro.
AB - OBJECTIVE: To characterize in part the factor(s) in conditioned medium (CM) that
maintains sperm motility after human oviductal cell culture. DESIGN: Controlled,
experimental, laboratory study. SETTING: University-based gynecology unit.
PATIENT(S): Fallopian tubes were obtained from patients who underwent tubal
ligation or hysterectomy. Semen with normal sperm parameters was obtained from
men who visited subfertility clinics. INTERVENTION(S): Spermatozoa were incubated
with CM and their motility was evaluated by a computer-aided sperm analysis
system. MAIN OUTCOME MEASURE(S): Curvilinear velocity, straight-line velocity,
average path velocity, linearity, amplitude of lateral head displacement, beat
cross-frequency, and percentage of spermatozoa that exhibited hyperactivation.
RESULT(S): Compared with their baseline motility (0 hour), spermatozoa incubated
with CM maintained various motility parameters for a longer period than did
control spermatozoa. All the motility parameters of the CM-treated spermatozoa
were higher than those of the control spermatozoa at the same time point. This
effect of CM was dose-dependent and increased with the duration of incubation.
The effect was stable at 56 degrees C but was not observed after 100 degrees C
heat treatment. Trypsin, but not proteinase K, abolished the effect. A fraction
with a molecular weight of <3 kd in the CM was responsible for the observed
effect. CONCLUSION(S): Human oviductal cells produce a peptide(s) that maintains
sperm motility.
PMID- 10689000
TI - Influence of parental and biological factors on the male birth fraction in the
United States: an analysis of birth certificate data from 1964 through 1988.
AB - OBJECTIVE: To determine the role of parental and biological factors on the U.S.
male birth fraction from 1964 through 1988. DESIGN: Logistic regression on annual
U.S. male births by race group. SETTING: Population-based data. PATIENT(S): Live
births in the United States 1964 through 1988. INTERVENTION(S): None. MAIN
OUTCOME MEASURE(S): Annual U.S. male birth fraction by parental and biological
factors. RESULT(S): During the study period, the annual U. S. male birth fraction
showed changes based on race group, parental age, and low birth weight. The
overall influence of parental age on the U.S. male birth fraction is strong and
is stronger in nonwhites than in whites. The U.S. male birth fraction is also
strongly influenced by the percentage of low birth weight infants in nonwhites,
but not in whites. The male birth fraction declines with increasing age of either
parent and with an increase in the percentage of low birth weight infants.
CONCLUSION(S): The relative magnitude of influences on the U.S. male birth
fraction depend on the race group, which may be a reflection of the range of
observed data rather than biological differences. The developed models have
reasonable predictive power and are an appropriate first step in understanding
the factors influencing the male birth fraction. These types of parental and
biological variables should be included in models before examining other
exogenous and population level variables.
PMID- 10689001
TI - Circulating leptin levels during ovulation induction: relation to adiposity and
ovarian morphology.
AB - OBJECTIVE: To assess serum leptin levels based on body habitus and ovarian
morphology during controlled ovarian hyperstimulation. DESIGN: Prospective
analysis. SETTING: University IVF program. PATIENT(S): Women undergoing IVF-ET
were divided into two groups, obese ovulatory women (n = 6; mean (+/-SD) body
mass index, 30.1 +/- 0.6 kg/m(2)) and lean ovulatory women (n = 20); mean (+/-
SD) body mass index 22.0 +/- 0.2 kg/m(2)). Lean women were categorized further
according to whether they had polycystic-appearing ovaries (n = 8) or normal
appearing ovaries (n = 12). INTERVENTION(S): Controlled ovarian hyperstimulation
and IVF. MAIN OUTCOME MEASURE(S): Serum estradiol, testosterone, and leptin.
RESULT(S): Mean (+/- SD) leptin levels were significantly higher before and after
GnRH agonist down-regulation in obese women (41.7 +/- 5.2 pg/mL and 36.1 +/- 5.8
pg/mL, respectively) compared with lean women (8.4 +/- 1.0 pg/mL and 6.9 +/- 1.1
pg/mL, respectively). Mean (+/- SD) leptin levels increased significantly in both
groups (54.5 +/- 5.1 pg/mL and 11.7 +/- 1.2 pg/mL, respectively), and the mean
(+/-SD) percentage increase was similar (55% +/- 18% and 54.8% +/- 17%,
respectively). Mean (+/-SD) leptin levels were similar in women with polycystic
appearing and normal-appearing ovaries before controlled ovarian
hyperstimulation, but increased significantly in women with polycystic-appearing
ovaries afterward (14.7 +/- 1.8 pg/mL and 9.3 +/- 1.0 pg/mL, respectively).
CONCLUSION(S): Significant increases in leptin levels occur during controlled
ovarian hyperstimulation, suggesting that leptin plays a role in follicular
growth and maturation. The exaggerated response in women with polycystic
appearing ovaries reflects either a greater number of recruited follicles or a
predisposition of adipocytes to leptin production.
PMID- 10689002
TI - Comparison of serum progesterone as an indicator of pregnancy nonviability in
spontaneously pregnant emergency room and infertility clinic patient populations.
AB - OBJECTIVE: To compare the predictive value of serum progesterone in identifying
nonviable pregnancy in symptomatic spontaneously pregnant emergency department
patients and asymptomatic patients attending an infertility clinic. DESIGN:
Retrospective study. SETTING: Tertiary-care academic health center. PATIENT(S):
One hundred thirty-seven pregnant patients who presented to the emergency
department for whom clinical outcomes were available, and 123 consecutive
patients who became pregnant during treatment at the infertility clinic.
INTERVENTION(S): Serum progesterone measurement. MAIN OUTCOME MEASURE(S): The
sensitivity, specificity, and predictive value of serum progesterone <45 nmol/L
in identifying nonviable pregnancies were determined for each of the groups.
RESULT(S): Sensitivity and specificity of serum progesterone <45 nmol/L in
predicting nonviable pregnancies were 88.6% and 87.5%, respectively, in
spontaneously pregnant patients who presented to the emergency department with
pain or bleeding and 58.8% and 100% in infertility patients who had undergone
controlled ovarian hyperstimulation for in vitro fertilization or intrauterine
insemination. Sensitivity and specificity for all other infertility clinic
patients were variable. CONCLUSION(S): The predictive value of low serum
progesterone in identifying nonviable pregnancies varies with patient
populations.
PMID- 10689003
TI - Second-trimester multifetal pregnancy reduction facilitates prenatal diagnosis
before the procedure.
AB - OBJECTIVE: To evaluate the pregnancy outcome of selective second-trimester
multifetal pregnancy reduction (MFPR) compared to first-trimester MFPR. DESIGN:
Cohort analysis. SETTING: In Vitro Fertilization Unit, Tel Aviv Sourasky Medical
Center, Tel Aviv, Israel. PATIENT(S): The study groups comprised 38 and 70
patients who underwent selective second-trimester MFPR (group 1) and first
trimester MFPR (group 2) at mean gestational ages of 19.7 +/- 3.3 weeks and 11.7
+/- 0.7 weeks, respectively. INTERVENTION(S): Ultrasonographically guided
intracardiac injection of potassium chloride (KCl) solution. MAIN OUTCOME
MEASURE(S): Pregnancy outcome and obstetric complications. RESULT(S): No
statistically significant difference was found between group 1 and group 2
regarding mean gestational age at delivery (35.4 +/- 3.4 weeks and 35.9 +/- 3.1
weeks, respectively); mean birth weight (2,318.9 +/- 565.7 g and 2, 138.1 +/-
529.4 g); and the incidence of obstetric complications. These complications
included pregnancy loss (5.2% and 15.7%), pregnancy-induced hypertension (0 and
10%), discordancy (12% and 18. 4%), intrauterine growth restriction (0 and 40%),
and gestational diabetes (0% and 6%). However, the rate of all pregnancy
complications was lower among second-trimester MFPR patients. CONCLUSION(S):
Selective second-trimester MFPR is associated with favorable perinatal outcome
and may facilitate detection of structural and chromosomal anomalies before the
procedure and selective reduction of the affected fetus.
PMID- 10689004
TI - No association between body mass index and beta(3)-adrenergic receptor variant
(W64R) in children with premature pubarche and adolescent girls with
hyperandrogenism.
AB - OBJECTIVE: To determine if the Trp(64)Arg (W64R) variant of the beta(3)
adrenergic receptor (ADRB3) could be used as a genetic marker to define risk for
polycystic ovary syndrom (PCOS) and/or obesity in children and adolescents.
DESIGN: Association study. SETTING: Academic research environment. PATIENT(S):
Children referred for evaluation of premature pubic hair (n = 63), adolescent
girls referred for evaluation of hirsutism and/or oligomenorrhea (n = 33), and
healthy adult controls (n = 67). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S):
Relationship of body mass index (BMI) to presence or absence of W64R variant and
frequency of W64R variant in our patient population. RESULT(S): Body mass index
(kg/m(2)) was determined for 63 children (55 girls and 8 boys) and 33 adolescent
girls. Presence or absence of the W64R variant was assayed by polymerase chain
reaction (PCR) amplification followed by allele-specific restriction fragment
digest. Twelve subjects and 11 healthy controls were found to be heterozygous for
the W64R variant. One subject was found to be homozygous for the W64R variant.
Allele frequency for the W64R variant was comparable between patients and
controls. Among the patients, mean BMI values were not different between carriers
and noncarriers. CONCLUSION(S): Although other studies suggest that the W64R
variant is associated with the development of obesity and insulin resistance, we
cannot demonstrate that it has a major effect on BMI in children with premature
pubarche or in adolescent girls with hyperandrogenism. Serial observations are
necessary to determine if this variant predicts the development of obesity and/or
PCOS in adulthood.
PMID- 10689005
TI - Comparison of the pharmacokinetics of crinone 8% administered vaginally versus
Prometrium administered orally in postmenopausal women(3).
AB - OBJECTIVE: Compare the pharmacokinetics of vaginal progesterone gel (Crinone 8%,
90 mg) with that of oral progesterone (Prometrium, 100 mg). DESIGN: Open-label,
randomized, parallel-group protocol. SETTING: Outpatient clinic. PATIENT(S):
Twelve healthy postmenopausal women. INTERVENTION(S): Six subjects each were
randomized to receive progesterone, which was administered either as 90 mg of
progesterone gel (Crinone 8%) given vaginally or 100 mg progesterone in a capsule
(Prometrium) given orally. MAIN OUTCOME MEASUREMENT(S): Serum progesterone levels
were measured by both radioimmunoassay (RIA) and liquid chromatography-mass
spectrometry (LC-MS). RESULT(S): Progesterone given vaginally resulted in greater
bioavailability with less relative variability in absorption than oral
progesterone (mean AUC(0-24) = 1.48 +/- 0.16 ng. h/mL per milligram vs. 0.035 +/-
0.0052 ng. h/mL per milligram). Mean C(max) for oral progesterone was much lower
than that of vaginal progesterone (i.e., 2.20 +/- 3. 06 ng/mL vs. 10.51 +/- 0.46
ng/mL). Mean T(max) occurred earlier for oral progesterone than for Crinone (1.00
+/- 0.41 hours vs. 7.67 +/- 3.67 hours). Radioimmunoassay is inappropriate for
determining serum progesterone levels after oral administration, because it
provided erroneously high values that were approximately eightfold higher than
those obtained with LC-MS. CONCLUSION(S): Crinone (progesterone gel) given
vaginally results in greater bioavailability with less relative variability than
oral progesterone, thus providing more reliable delivery of progesterone,
compared with oral progesterone. Measuring circulating progesterone with use of
direct RIA is not appropriate after oral progesterone administration.
PMID- 10689006
TI - Differentiating tubal abortion from viable ectopic pregnancy with serum CA-125
and beta-human chorionic gonadotropin determinations.
AB - OBJECTIVE: To determine whether serum CA-125 and serial beta-hCG levels can be
used to distinguish between tubal abortion and viable ectopic pregnancy (EP).
DESIGN: Retrospective cohort study. SETTING: A tertiary care institution.
PATIENT(S): Twenty-six women with EPs of 7-12 weeks' duration were studied
retrospectively. Five had laparoscopically proved tubal abortions and 21 had
active, viable EPs at the time of entry into the study. All but 3 of the latter
group were managed surgically; the others were given a single dose of
methotrexate. INTERVENTION(S): Surgical removal of EPs by means of laparoscopy or
laparotomy, or medical treatment of the disease. MAIN OUTCOME MEASURE(S): Serum
CA-125 and beta-hCG determinations were used to differentiate tubal abortion and
viable EP. The results were compared with the findings at surgery. RESULT(S): The
mean (+/-SD) CA-125 level was 112.2 +/- 11.9 IU/mL for the patients with tubal
abortion and 30.1 +/- 15.3 IU/mL for the patients with viable EP. The mean (+/
SD) beta-hCG level was 3,643 +/- 3,718 IU/L for the patients with tubal abortion
and 10,755 +/- 11,465 IU/L for the patients with viable EP. Linear regression
analysis showed a statistically insignificant inverse relation between serum CA
125 and beta-hCG levels. CONCLUSION(S): The use of CA-125 levels as an adjunct to
serial beta-hCG levels shows promise as a means for differentiating tubal
abortion from viable EP.
PMID- 10689007
TI - Pregnancy outcome is not affected by antiphospholipid antibody status in women
referred for in vitro fertilization.
AB - OBJECTIVE: To determine the prevalence of antiphospholipid (aPL) and anti-beta 2
glycoprotein I (anti-beta2-GPI) antibodies in women referred for IVF and to
prospectively evaluate the effect of these antibodies on IVF outcome. DESIGN:
Prospective observational study. SETTING: A university hospital and IVF unit.
PATIENT(S): Three hundred eighty consecutive women referred for IVF.
INTERVENTION(S): Blood samples taken before commencement of IVF cycles were
tested for the presence of aPL (lupus anticoagulant [LA], anticardiolipin [aCL],
and antiphosphatidyl serine antibodies [aPS]) and anti-beta2-GPI antibodies. MAIN
OUTCOME MEASURE(S): Antibody prevalence, pregnancy rates, and live birth rates.
RESULT(S): Of the total 380 women, 89 tested persistently positive for aPL
(23.4%). None of 176 women tested for IgG aPS antibodies had a positive titer.
Only 3.3% (11 of 329) tested positive for anti-beta2-GPI antibodies. Pregnancy
rate, live birth rate, gestational age at delivery, and birth weight were not
affected by aPL status. CONCLUSION(S): Although women referred for IVF have a
high prevalence of aPL, these antibodies do not affect the outcome of treatment.
Screening women undergoing IVF for aPL is not justified.
PMID- 10689008
TI - beta2-Glycoprotein 1 as a marker of antiphospholipid syndrome in women with
recurrent pregnancy loss.
AB - OBJECTIVE: To determine if beta2-glycoprotein 1 (beta2-GP1) antibodies are a
better marker of the antiphospholipid antibody syndrome (APS) in women with
recurrent pregnancy loss (RPL). DESIGN: Evaluation and testing of sera from women
with RPL. SETTING: A university-affiliated reproductive endocrinology practice.
PATIENT(S): 90 women with RPL; 45 women met criteria for APS and 45 women met
criteria for RPL without antiphospholipid antibodies (APA). Both groups were of
similar age and had a similar history of RPL. INTERVENTION(S): Patient sera were
obtained from women with RPL and were tested for APA and beta2-GP1. MAIN OUTCOME
MEASURE(S): A standard antiphospholipid antibody assay was employed to detect the
presence of immunoglobulin (Ig)G, IgM, and IgA antibodies in serum against
cardiolipin, phosphatidyl inositol, phosphatidyl glycerol, phosphatidyl serine,
and phosphatidyl ethanolamine. Samples were also assayed with a commercial beta2
GP1 assay for IgG antibodies. RESULT(S): Among the 45 women with APS, 10 (22.2%)
had positive IgG antibodies for beta2-GP1. Only 1 woman (2.2%) of 45 was positive
for beta2-GP1 among the control group of women with RPL but negative APA. There
was no correlation noted among the beta2-GP1-positive patients for a specific
phospholipid antibody or isotype. CONCLUSION(S): These data suggest that IgG
beta2-GP1 antibodies are less sensitive than antiphospholipid antibodies for the
diagnosis of APS.
PMID- 10689009
TI - Successful treatment of immunologic abortion with low-dose intravenous
immunoglobulin.
AB - OBJECTIVE: To evaluate the efficacy of low-dose intravenous immunoglobulin (IVIG)
treatment in older women with immunologic abnormalities and recurrent spontaneous
abortion (RSA), a condition referred to as immunologic abortion. DESIGN:
Prospective clinical trial. SETTING: Outpatient referral practice. PATIENT(S):
Forty-seven women were enrolled in the study. The mean age of the women was 37
years (range, 28-45 years), and the mean number of prior miscarriages was 3.7.
Immunologic abnormalities included antiphospholipid antibodies (32%), antithyroid
antibodies (53%), antinuclear antibodies (28%), antiovarian antibodies (2%),
increased natural killer cells (40%), increased immunoglobulin (Ig)M level (28%),
and increased CD4/CD8 T-cell ratio (15%). One patient had IgA deficiency, and
three women had endometriosis. Thirty-one of the 47 patients (66%) had more than
one immunologic abnormality. INTERVENTION(S): Treatment with IVIG at a dose of
0.2 g/kg within 2 weeks of attempted conception. Once conception was achieved,
IVIG treatment was continued on a monthly basis at the same dose through 26-30
weeks of gestation. MAIN OUTCOME MEASURE(S): Successful pregnancy or recurrent
abortion. RESULT(S): Of the 47 women, 36 received initial IVIG treatment, and 24
subsequently became pregnant. Of these women, 20 continued IVIG treatment through
26-30 weeks of gestation, and 19 (95%) had a successful term pregnancy. Four
women discontinued IVIG therapy after 10-12 weeks of gestation, and 3 (75%) had a
successful pregnancy outcome. Of the 11 women who refused IVIG therapy, 7 became
pregnant, and all 7 miscarried. The difference in pregnancy success rate between
the IVIG-treated and untreated groups was significant (P=.001). Three women had
adverse reactions during the low-dose IVIG infusion, and these reactions resolved
when the IVIG brand was changed. Fetal abnormalities were not observed.
CONCLUSION(S): Low-dose IVIG therapy is beneficial for older women with
immunologic abortion. The optimum duration of IVIG treatment in these women
requires further study.
PMID- 10689010
TI - Development of human oocytes matured in vitro for 28 or 36 hours.
AB - OBJECTIVE: To compare the effects on human oocytes of in vitro maturation periods
of 28 hours and 36 hours. DESIGN: Retrospective analysis. SETTING: University
teaching hospital. PATIENT(S): A total of 48 infertile patients undergoing 55
cycles who volunteered for the experimental treatments. INTERVENTION(S): Immature
oocytes were aspirated with use of transvaginal ultrasonography. Oocytes were
matured, fertilized by intracytoplasmic sperm injection, and cultured for 2.5 or
3 days before being replaced into the uterus. MAIN OUTCOME MEASURE(S): Oocyte
maturation, fertilization and cleavage rates, and clinical pregnancy rate.
RESULT(S): Maturation of oocytes for either 28 hours or 36 hours before
insemination resulted in similar rates of maturation, fertilization, and
cleavage. The clinical pregnancy rate was similar in both groups (14%-15%).
CONCLUSION(S): Shortening the in vitro maturation period does not compromise
subsequent embryonic development.
PMID- 10689011
TI - In vitro blastocyst formation of human oocytes obtained from unstimulated and
stimulated cycles after vitrification at various maturational stages.
AB - OBJECTIVE: To evaluate the developmental competence and chromosomal normality of
oocytes vitrified at various times after maturation culture. DESIGN: In vitro
model study. SETTING: A university-affiliated hospital. PATIENT(S): Unstimulated
women who underwent cesarean section or oophorectomy and infertile women who
underwent a long protocol of GnRH stimulation. INTERVENTION(S): Retrieved oocytes
were vitrified at 0 or 48 hours after culture in unstimulated cycles and at 0, 8
15, or 24-28 hours after culture in stimulated cycles. MAIN OUTCOME MEASURE(S):
Postthaw morphologic normality, maturation, fertilization, cleavage, blastocyst
formation, and chromosome number. RESULT(S): In the 53 oocytes that were obtained
from unstimulated cycles, no statistically significant differences were found in
rates of morphologic normality (range, 56%-63%) or fertilization (range, 31%-37%)
according to the time of vitrification. In the 50 oocytes that were obtained from
stimulated cycles, more of those that were vitrified at 24-28 hours were
morphologically normal than those that were vitrified at 0 or 8-15 hours.
Regardless of these differences, high cleavage rates (83%-100%) were obtained
that did not differ significantly among the treatment groups. In both cycles, 20%
43% of cleaved oocytes developed to the blastocyst stage by 6 days after IVF. All
the karyotyped blastocysts, three from unstimulated cycles and four from
stimulated cycles, had a normal number of chromosomes. CONCLUSION(S): Vitrified
and thawed oocytes from unstimulated or stimulated cycles developed to the
blastocyst stage, regardless of when vitrification occurred; the number of
chromosomes in the blastocysts was normal.
PMID- 10689012
TI - Basal follicle-stimulating hormone levels are of limited value in predicting
ongoing pregnancy rates after in vitro fertilization.
AB - OBJECTIVE: To evaluate whether basal FSH (bFSH; measured on menstrual day 1-4)
adds relevant clinical information to the prediction of ongoing pregnancy rates
(OPRs) after IVF, once age and diagnostic characteristics have been taken into
account. DESIGN: Retrospective. SETTING: Academic fertility center. PATIENT(S):
435 women undergoing their first IVF cycle. INTERVENTION(S): None. MAIN OUTCOME
MEASURE(S): Ongoing pregnancy rate. RESULT(S): The likelihood ratio of bFSH as a
single prognosticator for treatment failure at a cutoff level of 15 IU/L was
3.87. The proportion of patients with such a bFSH level was 5%. Multivariate
logistic regression analysis selected age, bFSH level, and infertility diagnosis
as relevant predictors of ongoing pregnancy. When compared to a predictive model
for OPRs based on age and infertility diagnosis, the inclusion of bFSH into this
model helped to identify more patients (22 vs. 1) whose predicted OPR decreased
from a low level (5%-12%) towards an extremely low level (<5%). CONCLUSION(S): An
acceptable performance of bFSH as a single test to predict treatment failure is
only obtained above a high cutoff level. Thus, the number of patients for whom
bFSH provides relevant information is small. The predictive model including bFSH
identified significantly more patients with an extremely poor prognosis than did
the predictive model without bFSH. However, predictions based solely on age and
infertility diagnosis usually were already poor in these patients. Measurement of
bFSH adds little in only a few patients and is, therefore, debatable.
PMID- 10689013
TI - The number of eight-cell embryos is a key determinant for selecting day 3 or day
5 transfer.
AB - OBJECTIVE: To select patients for day 3 vs. day 5 embryo transfer. DESIGN:
Retrospective analysis of assisted reproduction technology (ART) cycles comparing
outcomes of day 3 and day 5 transfers. SETTING: ART program of Brigham and
Women's Hospital. PATIENT(S): Patients with day 3 or day 5 embryo transfers (n =
221 and 141, respectively). INTERVENTION(S): Cycles with eight or more zygotes
were stratified by the number of eight-cell embryos available on day 3 (none, one
or two, or three or more). MAIN OUTCOME MEASURE(S): Number of blastocysts,
implantation rates, ongoing pregnancy rates, and number of fetal heart beats.
RESULT(S): With no eight-cell embryos on day 3, 0% and 33% pregnancies resulted
from day 5 vs. day 3 transfers. With one or two eight-cell embryos on day 3,
ongoing and high order multiple rates were not different between day 3 and day 5
transfers. With three or more eight-cell embryos, day 5 transfer resulted in a
decrease in multiple gestations but no difference in ongoing pregnancy rates
compared with day 3 transfer. CONCLUSION(S): With no eight-cell embryos on day 3,
a day 3 transfer is warranted. With one or two eight-cell embryos, any benefit of
day 5 transfer appears to be equivocal. With three or more eight-cell embryos,
day 5 transfer is recommended.
PMID- 10689014
TI - Parental adjustment and attitudes to parenting after in vitro fertilization.
AB - OBJECTIVE: To examine the psychosocial and parenthood-specific adjustment and
attitudes to parenting at 1 year postpartum of IVF parents. DESIGN: Prospective,
controlled study. SETTING: Volunteers in a teaching hospital environment.
PATIENT(S): Sixty-five primiparous women with singleton IVF pregnancies and their
partners, and a control group of 61 similarly aged primiparous women with no
history of infertility and their partners. INTERVENTION(S): Completion of
questionnaires and interviews. MAIN OUTCOME MEASURE(S): Parent reports of general
and parenthood-specific adjustment and attitudes to parenting. RESULT(S): The IVF
mothers tended to report lower self-esteem and less parenting competence than
control mothers. Although there were no group differences on protectiveness, IVF
mothers saw their children as significantly more vulnerable and "special"
compared with controls. The IVF fathers reported significantly lower self-esteem
and marital satisfaction, although not less competence in parenting. Both IVF
mothers and fathers did not differ from control parents on other measures of
general adjustment (mood) or those more specific to parenthood (e.g., attachment
to the child and attitudes to child rearing). CONCLUSION(S): The IVF parents'
adjustment to parenthood is similar to naturally conceiving comparison families.
Nonetheless, there are minor IVF differences that reflect heightened child
focused concern and less confidence in parenting for mothers, less satisfaction
with the marriage for the fathers, and vulnerable self-esteem for both parents.
PMID- 10689015
TI - Hierarchical logistic regression models for clustered binary outcomes in studies
of IVF-ET.
AB - OBJECTIVE: To describe a hierarchical logistic regression model for clustered
binary data, apply it to data from a study on the effect of hydrosalpinx on
embryo implantation, and compare the results with analyses that do not account
for clustering. DESIGN: Observational study. SETTING: Academic research
environment. PATIENT(S): Women undergoing IVF-ET for tubal disease. MAIN OUTCOME
MEASURE(S): Odds of per embryo implantation. RESULT(S): Although regression
estimates are largely similar between the models, the hierarchical model properly
reflects the added variation due to clustering. Standard errors are higher,
confidence intervals are wider, and P values indicate fewer "statistically
significant" effects. CONCLUSION(S): Ignoring important sources of variation in
any analysis can lead to incorrect confidence intervals and P values. In studies
of IVF-ET, where clustered data are common, unexplained heterogeneity can be
substantial. In this setting, hierarchical logistic regression is an appropriate
alternative to standard logistic regression.
PMID- 10689016
TI - Predictive value of 72-hour blastomere cell number on blastocyst development and
success of subsequent transfer based on the degree of blastocyst development.
AB - OBJECTIVE: To determine the predictive value of 72-hour blastomere cell number on
blastocyst development and to compare success rates of subsequent transfer based
on the degree of blastocyst development. DESIGN: Retrospective clinical study.
SETTING: Private assisted reproductive technology center. PATIENT(S): Ninety
three women aged 32.0 +/- 5.1 years undergoing oocyte retrieval for IVF.
INTERVENTION(S): Bipronucleate oocytes obtained from IVF were grown for up to 168
hours after fertilization and subsequently transferred at the blastocyst stage.
MAIN OUTCOME MEASURE(S): Percentages of embryos developing to blastocyst from 72
hour embryos by blastomere cell number and subsequent implantation and pregnancy
rates of transferred blastocysts. RESULT(S): Rates of blastocyst formation and
expansion increased as cell numbers at 72 hours increased. Implantation rates
were 43% for embryos transferred to women receiving only expanded blastocysts and
17% for embryos transferred to women receiving one or more less developed
blastocysts. Pregnancy rates were higher for women receiving only expanded
blastocysts than for women receiving one or more less developed blastocysts,
although the difference was not significant. CONCLUSION(S): More developed 72
hour embryos are more likely to become blastocysts and expand. Implantation rates
are greater for the transfer of expanded rather than unexpanded blastocysts.
PMID- 10689017
TI - Minimal stimulation IVF using clomiphene citrate and oral contraceptive pill
pretreatment for LH suppression.
AB - OBJECTIVE: To determine if oral contraceptive pill (OC) pre-treatment prior to
minimal stimulation IVF using clomiphene citrate (CC) would make the procedure
easier to perform by preventing the LH surge and result in pregnancy rates (PRs)
comparable to stimulated IVF. DESIGN: Prospective cohort study. SETTING: Private
tertiary infertility center. PATIENT(S): Thirty-two women with tubal or pelvic
adhesive disease as the cause of their infertility, ovulatory cycles, under the
age of 40, and no male factor. INTERVENTION(S): Two-month ovarian-hypothalamic
pituitary axis suppression with OC followed by CC 100 mg on day 3 of the cycle
for 8 days, hCG administration midcycle, follicle aspiration, IVF, and embryo
transfer. MAIN OUTCOME MEASURE(S): Oocytes retrieved, serum LH and estradiol
levels, maturity of oocytes, fertilization rates, embryo number and quality, and
PRs. RESULT(S): Thirty-six patients completed 71 stimulation cycles and 64
follicle aspirations. No LH surges occurred with a mean mature oocytes retrieved
of 3.2, 90% fertilization rate, and mean 2.5 embryos transferred. Twenty-one of
the 64 cycles resulted in a clinical pregnancy (32.8% PR per retrieval) with 2
other biochemical pregnancies and 3 twin gestations. This was not significantly
different from the matched cohort stimulated IVF. CONCLUSION(S): Minimal
stimulation IVF is a simple, low-cost, and low-risk alternative to stimulated IVF
with comparable PRs.
PMID- 10689018
TI - Comparison of two methods for the measurement of sperm concentration.
AB - OBJECTIVE: To determine the accuracy of both the hemocytometer and the MicroCell,
to evaluate which method is the most reliable, and to confirm the accuracy of
latex beads as an internal standard. DESIGN: Prospective procedural assessment.
SETTING: University-based infertility clinic. PATIENT(S): One hundred sixty-five
male sexual partners of women undergoing screening for infertility.
INTERVENTION(S): Semen analysis. MAIN OUTCOME MEASUREMENT(S): Sperm and latex
bead concentrations. RESULT(S): Sperm concentration values obtained with the
hemocytometer were highly correlated with those obtained from the MicroCell (r =
0.88). The mean value of the latex beads concentration was closer to the standard
value using the hemocytometer than the MicroCell. CONCLUSION(S): Both the
hemocytometer and the MicroCell are suitable as screening techniques to measure
sperm concentration. Fixed suspensions of latex beads serve as reliable internal
quality control standards.
PMID- 10689019
TI - Evaluation of a large cohort of men presenting for a screening semen analysis.
AB - OBJECTIVE: To determine: [1] what percentage of men in an infertile relationship
will have a semen abnormality, [2] the average value for each semen parameter in
this group of men, [3] the distribution of abnormal semen parameters in this
group, and [4] if our data support the hypothesis that sperm concentration is
declining. DESIGN: Retrospective cohort study. SETTING: County hospital
university-based infertility clinic. PATIENT(S): Male partners of women
presenting for an infertility evaluation. INTERVENTION(S): Semen specimens were
collected after 2-5 days of abstinence. MAIN OUTCOME MEASURE(S): Sperm
concentration, motility, and morphology. RESULT(S): Fifty-two percent of samples
had at least one sperm abnormality based on World Health Organization criteria.
Fifty-one percent had an abnormality in sperm motility, 18% in sperm
concentration, and 14% in sperm morphology. Four percent of the patients were
azoospermic. CONCLUSION(S): No decline in sperm density was revealed in semen
collected by men presenting for an initial screening semen analysis.
PMID- 10689020
TI - Transplantation of cryopreserved human ovarian tissue results in follicle growth
initiation in SCID mice.
AB - OBJECTIVE: To determine the long-term survival of frozen-thawed human ovarian
tissue as xenografts in severe-combined-immunodeficiency (SCID) mice. DESIGN:
Animal study. SETTING: Animal and laboratory facilities at an academic center.
PATIENT(S): Ovarian tissue obtained from a 27-year-old woman. INTERVENTION(S):
Grafting of frozen-thawed ovarian tissue in SCID mice for 22 weeks. MAIN OUTCOME
MEASURE(S): Follicle counts and growth by morphology and PCNA staining in frozen
thawed grafts and fresh controls. RESULT(S): All three grafts were recovered
intact after 22 weeks. Their stroma was devoid of necrotic cells and contained
healthy follicles. The ratio of primordial-total follicles decreased
significantly after grafting (0.94 +/- 0.02 to 0.87 +/- 0. 01, control vs.
grafting). Compared with controls, after 22 weeks of grafting, a higher
percentage of follicles had initiated growth (5.6 +/- 2.4 vs. 12.5 +/- 1.9), but
there was still a significant number of primordial follicles/graft (75 +/- 6.8).
Follicle stages were similar between two groups; only primordial and one-layer
follicles were seen in the xenografts. In the controls, except for one two-layer
follicle, the most advanced follicle was at the one-layer stage. CONCLUSION(S):
Human primordial follicles survive freeze-thaw and long-term xenografting
procedures and retain their capacity to initiate growth. These findings encourage
future attempts for human autologous ovarian transplantation.
PMID- 10689021
TI - Matrix metalloproteinases and their tissue inhibitors in antegradely shed
menstruum and peritoneal fluid.
AB - OBJECTIVE: To investigate the expression of matrix metalloproteinases (MMPs) and
their tissue inhibitors (TIMPs) in antegradely shed menstruum and peritoneal
fluid. DESIGN: A cell biological and immunohistochemical study. SETTING: Tertiary
care university medical center. INTERVENTION(S): Immunohistochemistry was
performed on cryostat sections and cultures of menstrual endometrium. Zymography
was used to characterize MMP activity in peritoneal fluid, in menstrual serum,
and in conditioned medium. Western blot analysis was used to further identify the
MMPs in these fluids. MAIN OUTCOME MEASURE(S): Staining of MMPs and TIMPs in
cryostat sections and cultures and MMP expression and activity in peritoneal
fluid and menstrual blood serum. RESULT(S): Strong staining for MMP-1 and MMP-3
was observed in stroma and for MMP-7 in epithelium. Matrix metalloproteinase-2
and MMP-9 were weakly expressed in stroma. Both TIMP-1 and TIMP-2 were expressed
in menstrual endometrium. Menstrual serum showed a pattern of MMP activity on
zymography different from peritoneal fluid. Western blot analysis showed the
presence of MMP-7 and MMP-9 in menstrual serum. CONCLUSION(S): Antegradely shed
menstrual endometrium expresses several MMPs and TIMPs, even after culturing for
24 hours. MMP activity in menstrual serum is different from and more intense than
MMP activity in peritoneal fluid. These enzymes may be involved in the early
invasion of menstrual endometrium into the extracellular matrix of the
peritoneum.
PMID- 10689022
TI - Protein tyrosine kinase activity of lavendustin A and the phytoestrogen genistein
on progesterone synthesis in cultured rat ovarian cells.
AB - OBJECTIVE: To compare the effects of two protein tyrosine kinase inhibitors,
lavendustin A and the phytoestrogen genistein, on progesterone synthesis in
cultured rat ovarian cells. DESIGN: Experimental animal study. SETTING: Medical
school laboratory. ANIMAL(S): Porton Wistar rats. INTERVENTION(S): Ovaries from
estrous rats were used to establish cell cultures of granulosa-luteal cells from
freshly ruptured follicles, granulosa-luteal cells cocultured with peritoneal
macrophages, and whole ovarian dispersates. MAIN OUTCOME MEASURE(S): Progesterone
and nitrite concentrations in the culture medium. RESULT(S): The protein tyrosine
kinase inhibitors suppressed steroid synthesis in a dose-dependent manner and
completely inhibited the steroidogenic response to both FSH and the adenyl
cyclase stimulator forskolin. The inhibitory action of cocultured macrophages on
basal and forskolin-stimulated progesterone production in granulosa-luteal cells
was not reversed by genistein, nor was the inhibitory effect of interleukin-1beta
in cultures of ovarian dispersates. CONCLUSION(S): Genistein and the
nonestrogenic protein tyrosine kinase inhibitor lavendustin A exert potent
inhibitory effects on steroidogenesis that are independent of cytokines. The
toxic effects of genistein on sexual development and reproduction may be
attributed not only to its estrogenic action but also to its action as a protein
tyrosine kinase inhibitor.
PMID- 10689023
TI - Clomiphene citrate-induced perturbations during meiotic maturation and
cytogenetic abnormalities in mouse oocytes in vivo and in vitro.
AB - OBJECTIVE: To determine if clomiphene citrate induces temporal perturbations
during meiotic maturation and aneuploidy in mouse oocytes. DESIGN: A controlled
dose study involving mouse oocytes in vivo and in vitro. SETTING: Clinical and
academic research setting in a university medical center. INTERVENTION(S):
Oocytes were obtained after superovulation and from mature follicles. MAIN
OUTCOME MEASURE(S): Cytogenetic analysis of oocytes for aneuploidy, premature
centromere separation, premature anaphase, and single chromatids, and the
frequencies of metaphase I and diploid oocytes. RESULT(S): Clomiphene citrate
resulted in a decrease in the number of ovulated oocytes and a significant
(P<.05) increase in hyperploidy at 100 mg/kg in vivo. In vitro, 5.0 microg/mL of
clomiphene citrate significantly (P<.05) increased hyperploidy and reduced the
proportion of metaphase I oocytes. CONCLUSION(S): These findings suggest that
clomiphene citrate has the potential for inducing aneuploidy in mouse oocytes
both in vivo and in vitro and that the rate of oocyte maturation is altered after
clomiphene exposure in vitro. Additional data are needed to support the results
of this study.
PMID- 10689024
TI - The expression of DAZL1 in the ovary of the human female fetus.
AB - OBJECTIVE: To determine whether DAZL1 is expressed in human fetal ovarian tissue.
DESIGN: The presence of DAZL1 expression was determined by reverse transcriptase
polymerase chain reaction (RT-PCR). SETTING: Academic tertiary care medical
center and research unit of university. PATIENT(S): Five female abortuses between
the 19th and 22nd week of gestational age. INTERVENTION(S): Fetal ovarian tissues
were collected immediately after the cessation of the heart beat. MAIN OUTCOME
MEASURE(S): The product of RT-PCR. RESULT(S): DAZL1 expression was detected in
all five samples. CONCLUSION(S): DAZL1 is not only expressed in human testes but
also in ovaries. It may play a role in germ cell survival and gonad development
in both sexes.
PMID- 10689025
TI - Role of microlaparoscopy in the diagnosis of peritoneal and visceral adhesions
and in the prevention of bowel injury associated with blind trocar insertion.
AB - OBJECTIVE: To determine the frequency of peritoneal and visceral adhesions to the
umbilical region according to past surgical history and to estimate the risk of
bowel injury with blind insertion of the principal trocar-cannula. DESIGN:
Prospective, unicentric study by a single operator. SETTING: Clinique Saint
Sernin and Polyclinique de Bordeaux, Bordeaux, France. PATIENT(S): Eight hundred
fourteen patients undergoing diagnostic or operative laparoscopy were classified
into four groups based on their history of abdominal surgery: group I (n = 469),
no previous abdominal surgery; group II (n = 125), prior laparoscopic surgery;
group III (n = 131), previous laparotomy with a horizontal supra-pubic incision;
group IV (n = 89), previous laparotomy with a midline incision. INTERVENTION(S):
Initial microlaparoscopy performed through the left upper quadrant of the
abdomen, inspection of the anterior abdominal wall and particularly the umbilical
area for the presence of adhesions. Patients who had adhesions were assessed as
to whether or not they were at significant risk of injury from blind insertion of
the principal trocar. MAIN OUTCOME MEASURE(S): Incidence of umbilical adhesions
and the potential risk of bowel injury with blind insertion of the umbilical
(principal) trocar. RESULT(S): Umbilical adhesions were found in 9.82% of the 814
cases. The rates of umbilical adhesions were as follows: group I, 0.68%; group
II, 1.6%; group III, 19.8%; and group IV, 51.7%. Severe adhesions with potential
risk of bowel injury with blind insertion of the umbilical trocar in the four
groups were 0.42%, 0.80%, 6.87%, and 31.46%, respectively. CONCLUSION(S): Women
with previous laparotomy have a higher incidence of umbilical adhesions,
especially in case of midline incision. Preliminary inspection of the umbilical
area with a microlaparoscope and insertion of the umbilical trocar under direct
vision are recommended for patients at risk for adhesions to reduce complications
associated with insertion of the principal (umbilical) trocar.
PMID- 10689026
TI - Using videotaped specimens to test quality control in a computer-assisted semen
analysis system.
AB - OBJECTIVE: To determine the feasibility of using semen samples previously
recorded on videotape for intralaboratory and interlaboratory quality control of
computer-assisted semen analysis (CASA) systems. DESIGN: Blinded, controlled
study. SETTING: Pooled semen specimens from two normal human volunteers in an
academic research environment. PATIENT(S): None. INTERVENTION(S): None. MAIN
OUTCOME MEASURE(S): Semen parameters from a videotape analyzed internally and by
four external laboratories. RESULT(S): Preliminary experiments designed to
examine intralaboratory variation by repeated analysis of semen samples recorded
on videotape revealed some significant differences for every variable examined.
When these data were analyzed by using the larger biologic error caused by
subsampling, no significant differences were found for any of the variables
examined. When either a standard set or the specific laboratories' sets of
parameters were used to analyze the same videotaped semen specimen, no
statistically significant differences were detected for sperm concentration for
motility among the five laboratories after the biological error caused by
subsampling was applied to results. CONCLUSION(S): These data strongly suggest
that videotaped semen specimens can serve as quality control for intralaboratory
and interlaboratory testing of CASA equipment as long as the biologic error
caused by subsampling is used to compare results.
PMID- 10689027
TI - Pregnancy after polar body biopsy and freezing and thawing of human embryos.
AB - OBJECTIVE: To evaluate the outcome of frozen-thawed ET using embryos previously
biopsied for preimplantation genetic diagnosis during a fresh ET cycle. DESIGN:
Prospective evaluation. SETTING: Assisted reproductive biology program.
PATIENT(S): A 31-year-old, G4, P1, TAB1, SAB2 carrier of a balanced RT 45,XX
der(14;21)(q10;q10) translocation. INTERVENTION(S): Preimplantation genetic
diagnosis by polar body biopsy. Excess embryos were frozen using the one-step
method and then thawed. MAIN OUTCOME MEASURE(S): Embryo survival after thawing
and subsequent pregnancy outcome. RESULT(S): Among the 32 mature oocytes, the
results of fluorescence in situ hybridization were available for 25 polar bodies.
Eleven were unbalanced, 10 were normal (8 fertilized), and 4 were balanced (3
fertilized) for the fresh IVF cycle. Two normal embryos were transferred. Four
normal and 3 balanced embryos were cryopreserved. A chemical pregnancy resulted.
Four months later, the 7 cryopreserved embryos were thawed; 2 survived (1
balanced and 1 normal) and were transferred. An ongoing pregnancy resulted, and a
normal (46,XX) female was delivered. CONCLUSION(S): Freezing and thawing of
biopsied embryos resulted in a low survival rate. However, this should not be a
deterrent to the cryopreservation of extra chromosomally normal embryos because
the embryos that do survive are able to implant.
PMID- 10689028
TI - Is affect associated with infertility treatment outcome?
PMID- 10689029
TI - Acute adnexal torsion before oocyte retrieval in an in vitro fertilization cycle.
PMID- 10689030
TI - The effects of hand preference and gender on finger tapping performance asymmetry
by the use of an infra-red light measurement device.
AB - We used an infra-red device to study the effects of gender and handwriting
preference on manual asymmetry in tapping rate and intertap variability. Our
sample (n=102) consisted of approximately equal number of subjects with respect
to gender (52 women and 50 men) and handedness (52 right-handers and 50 left
handers). Data on overall performance indicated that men performed more quickly
and regularly than women. The index used for measuring manual asymmetry was the
difference between the hands as a proportion of the total. Therefore, the
asymmetry index was adjusted to remove the influence of overall performance. The
analyses based on asymmetry scores indicated a significant handedness effect:
right-handers showed greater manual asymmetries than left-handers for both
tapping rate and intertap variability. In addition, right handers exhibited a
significant greater asymmetry for intertap variability than tapping rate. Taken
together, these data may reflect greater hemispheric differences in right
handers, specially for intertap variability.
PMID- 10689031
TI - Crossed-uncrossed difference in simple reaction times to lateralized flashes:
between- and within-subjects variability.
AB - In unimanual reaction times (RT) to lateralized flashes, contralateral responses
tend to be slower than ipsilateral responses. This has been called Crossed
Uncrossed Difference (CUD). The CUD tends to show variability across subjects and
across studies, but until now the stability of the CUD in an individual subject
has not been investigated. To address the role of inter- and intra-subject
variability in the CUD, three normal right handers were tested over 50
experimental sessions of 800 trials each, for a total of 40,000 trials of simple
reaction times to lateralized flashes. In each subject, CUDs were computed for
each session, over two, three, or more sessions, and over the entire dataset.
These CUDs were then compared to the CUDs obtained in a group of 15 normal right
handers, each tested once in a single session. Results show that: (i) CUD
variability across several sessions in a single subject mimics the variability
observed in a sample of subjects tested in a single session; (ii) this
variability is considerably reduced when the CUD is computed over at least 2400
trials per subject; (iii) CUDs computed over 2400 and up to 12,000 of trials tend
to be extremely similar ( approximately 2 ms) across the three subjects tested
here; (iv) when reaction times are ordered from the fastest to the slowest and
divided into bins, the CUD is remarkably stable over the entire reaction time
distribution; and (v) in contrast to the variability of the CUD, the variability
for crossed and uncrossed responses across several sessions in a single subject
is small and does not mimic the variability observed in a sample of subjects
tested in a single session. Taken together, these data suggest that the
intersubject variability in the CUD observed in single experimental sessions does
not represent a reliable intersubject difference and that the CUD computed over
thousands of trials reflects hard-wired mechanisms of callosal transmission.
PMID- 10689032
TI - An event-related potential study of encoding in young and older adults.
AB - Event-related brain potentials (ERPs) were recorded from young (M age=25) and
older (M age=71) adults during the study phase of a recognition memory paradigm.
Participants studied two temporally distinct lists of sentences (each containing
two unassociated nouns). During recognition testing, in response to the nouns,
participants made old/new, followed by remember (context)/know (familiarity) and
temporal source (i.e., list) judgments. To assess age-related differences in
encoding, the ERPs recorded during study were averaged as a function of the
correctness of the judgment of old in conjunction with subsequent temporal (list
correct/incorrect) and subsequent remember and know judgments, i.e., subsequent
memory or Dm effects were computed. Both young and old showed robust Dm activity
regardless of whether the subsequent temporal source judgment was correct or
incorrect. Although both young and old produced robust Dm effects for study items
subsequently associated with a remember judgment, only the older participants
showed a reliable Dm effect associated with study trials that were subsequently
associated with a know judgment. This pattern of results suggests that older
adults did not differentially encode items that would be subsequently retrieved
with context from those that would be retrieved without such attributes.
PMID- 10689033
TI - Temporal control of a bimanual task in patients with cerebellar dysfunction.
AB - The objective of the study was to investigate whether temporal control during a
goal-directed bimanual action is disturbed in cerebellar patients. The task was
to open a drawer with one hand and to reach and grasp a small object with the
other hand. Interlimb coupling was determined at start and end positions.
Cerebellar patients as compared to normal subjects showed an increased offset for
initiating the hand movements which denotes the involvement of the cerebellum for
organizing the components underlying the bimanual task. The reduced simultaneity
was caused by a delayed movement onset of the grasping (non-leading) hand as
compared to the pulling hand. Lack of vision increased the degree of
desynchronization for the patients at the start position, indicating that they
depended on external cues for organizing the temporal coordinates of the combined
motion pattern. At the goal, the magnitude of temporal offset was similar/smaller
than at movement onset which can be related to feedforward mechanisms that are
used to anticipate the limbs' end positions. These results confirm the role of
the cerebellum for planning the temporal ordering of movement sequences into a
synergic action.
PMID- 10689034
TI - Blindness to form from motion despite intact static form perception and motion
detection.
AB - We studied the motion perception, including form and meaning generated by motion,
in a hemianopic patient who also had visual perceptual impairments in her seeing
hemifield as a result of a lesion in ventral extrastriate cortex. She was unable
to recognise 2- or 3-dimensional forms, and even borders, generated by motion
alone, failed to recognise mimed actions or the Johannson 'biological motion'
display, and ceased to recognise people well-known to her when they moved. Her
performance with static displays, although impaired, could not explain her
inability to perceive shape or derive meaning from moving displays. Unlike a
motion-blind patient, she can still see and describe the motion, with the
exception of second-order motion, but not what it creates or represents.
PMID- 10689035
TI - Diagnosis of Alzheimer's disease: MRI of the hippocampus vs delayed recall.
AB - Hippocampal volume measurements using magnetic resonance imaging (MRI) and
assessment of performance in tests of delayed recall are among the most useful
aids for diagnosing early Alzheimer's disease (AD) on an individual level.
However, their comparative diagnostic accuracy has not been previously addressed.
In this study we compared the diagnostic accuracy of these two methods in 57
patients with probable AD according to the NINCDS-ADRDA criteria, and 34 age- and
gender-matched control subjects. The discriminatory power of the hippocampal
volumes and delayed recall performance, Russel's Adaptation of the Visual
Reproduction Test (VRT), were compared in discrimination function and receiver
operator characteristic analyses. Right and left hippocampal volumes resulted in
correct classification of 85.7-86.8% of the study subjects, respectively, while
performance in the VRT resulted in correct classification of 93.4% of subjects.
The area under curve value was 0.93 for the left hippocampus and 0.96 for the
VRT. These data suggest that assessment of delayed recall with the VRT is of high
diagnostic accuracy, and may surpass the diagnostic accuracy of hippocampal
volumetry.
PMID- 10689036
TI - The automatic updating of egocentric spatial relationships and its impairment due
to right posterior cortical lesions.
AB - The non-visual updating of body-centred spatial relationships was investigated in
an experiment in which blindfolded patients had to point to previously seen
targets after a body rotation in the absence of vision. Patients with lesions to
the right dorsal (RD) area were impaired at updating their positions relative to
non-RD patients and normal subjects: they tended to underestimate systematically
the angle through which they had turned. The results are interpreted in terms of
impoverished locomotor input and/or systematically biased processing or locomotor
proprioception in the RD patients, which prevented accurate tracking of changes
in egocentric spatial relationships.
PMID- 10689037
TI - Probabilistic learning and reversal deficits in patients with Parkinson's disease
or frontal or temporal lobe lesions: possible adverse effects of dopaminergic
medication.
AB - Three groups of patients with Parkinson's disease (PD) - mild, unmedicated (UPD),
mild, medicated (MPD) and severe, medicated (SPD) - and patients with lesions of
the frontal lobe (FLL) or temporal lobe (TLL) were compared with matched controls
on the learning and reversal of probabilistic and two-pair concurrent colour
discriminations. Both of the cortical lesion groups showed reversal deficits,
with no increase in perseverative responding. The UPD group, although impaired on
a spatial recognition task, showed intact discrimination learning and reversal;
the MPD and SPD patients showed non-perseverative reversal impairments on both
reversal tasks. Two hypotheses - based on disease severity and possible
deleterious effects of medication - are offered to explain the reversal
impairments of the PD patients and the results are discussed in terms of the role
of dopamine in reward-based learning.
PMID- 10689038
TI - Neuropsychology of infarctions in the thalamus: a review.
AB - From a review of the literature on the consequences of thalamic infarctions, it
may be concluded that memory problems taking the form of an amnesic syndrome are
dependent upon the integrity of the mammillo-thalamic tract (MTT). Memory
problems incompatible with an amnesic syndrome however, appear to result from
thalamic infarctions involving other areas of the thalamus but which leave MTT
intact. In contrast, executive dysfunctions could not be shown so readily to
depend upon a single structure of the thalamus. The results indicate that damage
to the mediodorsal nucleus of the thalamus, the midline nuclei or the
intralaminar nuclei, or a combined lesion of these structures may be responsible
for deficits of executive functioning.
PMID- 10689040
TI - Asynchrony of lexical and morphosyntactic development in children with Down
Syndrome.
AB - The aim of this study was to investigate the potential dissociation between
mental age and specific aspects of language: lexical and morphosyntactic
comprehension and production in different situations and with different measures.
Fifteen children with Down Syndrome (DS) (from 4 to 7 years) and fifteen normal
controls matched on mental age participated in this study. Children with DS
showed generally a lower performance in language abilities with respect to the
normal controls. In the two groups no dissociation was evident between lexical
and cognitive abilities, but specific morphosyntactic difficulties emerged both
in comprehension and production.
PMID- 10689039
TI - Effects of unilateral posteroventral pallidotomy on 'on-off' cognitive
fluctuations in Parkinson's disease.
AB - In Parkinson's disease, cognitive performance can vary according to levodopa
levels (on-off states). Both positive and negative effects of dopaminergic
stimulation have been reported. Pallidotomy is also able to change cognitive
performance, in addition to levodopa pharmacokinetics. The aim of this
investigation was to study the effects of pallidotomy on cognitive on-off
fluctuations in Parkinson's disease. A brief neuropsychological battery was
administered to 15 PD patients during on and off states before and after surgery.
Before pallidotomy, patients performed better in the on condition on Trail Making
test B; after pallidotomy levodopa no longer improved performance, and the
interaction between surgery and state was significant. In relation to the
difference between preoperative and postoperative performance in Trail Making B
test, there was a significant postsurgical improvement only in off state. Verbal
fluency decreased after pallidotomy in both on and off conditions. Our results
suggest that pallidotomy can change the effects of levodopa on neuropsychological
functions.
PMID- 10689041
TI - Impaired novelty detection and frontal lobe dysfunction in Parkinson's disease.
AB - Recent evidence suggests that the frontal lobe plays an important role in an
orienting response to novel events, and that frontal lobe dysfunction is linked
to attentional and cognitive deficits in Parkinson's disease (PD). We tested the
hypothesis that the neural network involved in novelty detection may be impaired
in PD patients by studying event-related brain potentials to target and novel
stimuli and their correlation to performance in neuropsychological tests in non
demented PD patients. The PD patients showed prolonged P3 latency to novel
stimuli compared with age-matched controls, whereas their P3 latency to target
stimuli was not different from that in controls. The PD patients also manifested
amplitude reduction and less habituation of the P3 to novel stimuli over frontal
scalp sites compared with controls. The prolonged latency and frontal reduction
of novelty P3 correlated with a poor performance in the Wisconsin Card Sorting
Test. These results suggest that the orienting response of PD patients to novel
events is impaired and that recording novelty P3 might provide a
neurophysiological and quantitative measure of attentional and cognitive deficits
linked to the frontal lobe in non-demented PD patients.
PMID- 10689042
TI - Planning impairments in frontal lobe dementia and frontal lobe lesion patients.
AB - Patients with frontal lobe brain damage are reportedly impaired on tasks that
require plan development and execution. In this study, we examined the
performance of 15 patients diagnosed with frontal lobe dementia and 14 patients
with focal frontal lobe lesions on the Tower of London planning task. Patients
with frontal lobe dementia committed a significantly higher number of rule
violations, made more moves, and demonstrated longer solution time latencies
compared to their matched controls. Patients with frontal lobe lesions
demonstrated significantly delayed solution times and also made more moves
compared to their matched controls. Frontal lobe lesion patient performance
suggests an impairment in execution-related processes, while frontal lobe
dementia patients appear to be impaired in both plan development and execution.
Despite these findings, the identification of a specific cognitive impairment
that induces these planning problems remains elusive.
PMID- 10689043
TI - A meta-analysis of indirect memory tests for novel material in organic amnesics.
AB - A meta-analysis was conducted on studies of implicit memory for novel and
familiar information in organic amnesic patients and healthy controls. Across
studies, the amnesics performed equivalently to the controls on indirect memory
tests for familiar information. However, the controls performed better than
amnesics for indirect memory tests for novel item and novel associative
information. This is in accord with memory theories which suggest that medial
temporal lobe structures are essential for encoding and storing arbitrary
associations between items or events.
PMID- 10689044
TI - Asymmetric frontal activation during episodic memory: the effects of stimulus
type on encoding and retrieval.
AB - Recent functional neuroimaging studies have suggested that the left prefrontal
cortex is preferentially involved in the encoding of episodic memory whilst the
right prefrontal cortex is preferentially involved in the retrieval of episodic
memory, irrespective of the type (e.g. modality) of information being remembered.
In the present PET activation study, a 2 x 2 design was employed to investigate
the relationship between encoding and retrieval of verbal and non-verbal material
in episodic memory. Accordingly, seven healthy volunteers were scanned whilst
encoding and then recalling stimuli which either emphasised visual or verbal
processes. When encoding and retrieval tasks were compared directly,
significantly greater prefrontal activation was observed in the encoding
conditions, regardless of modality, although these changes were bilaterally
distributed. In contrast when the verbal and visual memory tasks were compared
directly, the former was associated with rCBF changes that were predominantly
located in the left lateral frontal cortex whilst the latter was associated with
rCBF changes that were predominantly located in the right lateral frontal cortex.
These results suggest that encoding and retrieval may actually involve similar
regions of the lateral prefrontal cortex when all factors relating to the type of
stimulus material (i.e. modality), are appropriately controlled.
PMID- 10689045
TI - Faces call for attention: evidence from patients with visual extinction.
AB - Three patients with left spatial neglect and visual extinction from right brain
damage were studied to determine whether faces are privileged in summoning
attention. In a first experiment, either a face, a name, or a meaningless shape
were briefly presented in the right, left or both visual hemifields. On bilateral
trials, all patients extinguished a left-side face much less often than a left
side name or a left-side shape. Conversely, they extinguished a left-side shape
more often when it was accompanied by a right-side face rather than a right-side
name. In a second experiment, either a face or a scrambled face could appear in
the right, left or both hemifields. Again, on bilateral trials, a left-side face
was less likely to be missed than a scrambled one. These results suggest an
advantage of faces in capturing attention and overcoming extinction, which may be
related to their special biological and social value, or to the very efficient
and automatic operation of specific perceptual processses that extract facial
organization in extrastriate visual areas. These findings also demonstrate that
the distribution of spatial attention and extinction can be modulated by the
relevance of visual stimuli. This implies that substantial analysis and
categorization may take place in the visual system before information from the
contralesional field is selected for, or excluded from, attentive vision.
PMID- 10689046
TI - An ERP study of the temporal course of the Stroop color-word interference effect.
AB - The electrophysiological correlates of the Stroop color-word interference effect
were studied in eight healthy subjects using high-density Event-Related
Potentials (ERPs). Three response modalities were compared: Overt Verbal, Covert
Verbal, and Manual. Both Overt Verbal and Manual versions of the Stroop yielded
robust Stroop color-word interference as indexed by longer RT for incongruent
than congruent color words. The Incongruent vs Congruent ERP difference wave
presented two effects. A first effect was a medial dorsal negativity between 350
500 ms post-stimulus (peak at 410 ms). This effect had a significantly different
scalp distribution in the Verbal and Manual Stroop versions, with an anterior
medial focus for overt or covert speech, and a broader medial-dorsal distribution
for the manual task. Dipole source analysis suggested two independent generators
in anterior cingulate cortex. Later on in time, a prolonged positivity developed
between 500-800 ms post-stimulus over left superior temporo-parietal scalp. This
effect was present for all the three response modalities. A possible
interpretation of these results is that Stroop color-word interference first
activates anterior cingulate cortex (350-500 ms post-stimulus), followed by
activation of the left temporo-parietal cortex, possibly related to the need of
additional processing of word meaning.
PMID- 10689047
TI - Distinctive patterns of memory function in subgroups of females with Turner
syndrome: evidence for imprinted loci on the X-chromosome affecting
neurodevelopment.
AB - X-monosomy is a form of Turner syndrome (TS) in which an entire X chromosome is
missing. It is usually assumed that neuropsychological deficits in females with
TS result from insufficient dosage of gene products from alleles on the sex
chromosomes. If so, then parental origin of the single X chromosome should be
immaterial. However, if there are imprinted genes on the X chromosome affecting
brain development, neuropsychological development will depend on the parental
origin of the single X chromosome. We contrasted verbal and visuospatial memory
in females with a single paternal X chromosome (45,X(p)) and those with a single
maternal X (45,X(m)). Neither group showed any impairment on immediate story
recall; if anything, performance was above control levels. Groups did not differ
on a measure of delayed recall. However, when delayed recall was considered after
adjusting for level of immediate recall, 45,X(m) females showed enhanced verbal
forgetting relative to controls over a delay. On the Rey figure, both groups were
poor at copying the figure, but, after adjusting scores for initial copy score
and strategy, only the 45,X(p) females showed disproportionate forgetting
relative to controls. We propose there may be one or more imprinted genes on the
X chromosome that affect the development of lateralised brain regions important
for memory function.
PMID- 10689048
TI - Coding space within but not between objects: evidence from Balint's syndrome.
AB - The ability to make spatial judgements was examined in a patient demonstrating
poor perception of multiple objects following bilateral parietal lesions, under
conditions in which the presence of the stimuli to which judgements were made
could be detected. The tasks required judgements of spatial length or the
position of coloured parts of stimuli. We manipulated the degree to which two
uprights in a display could be encoded into a single perceptual object using
either stored knowledge or bottom-up cues based on 2D or 3D image relations.
Performance was dependent on the presence of both bottom-up grouping and
familiarity. However, connectedness in the image was not sufficient to benefit
performance, when stimuli were separate objects in 3D space. This deficit in
spatial judgements, arising following detection of the relevant stimulus
elements, is attributed to an impairment in coding the spatial relations between
separate perceptual objects. This deficit could be overcome if stimuli could be
grouped in 3D, using bottom-up cues and top-down knowledge.
PMID- 10689049
TI - Verbal fluency and executive dysfunction in amyotrophic lateral sclerosis (ALS).
AB - Neuropsychological investigations of amyotrophic lateral sclerosis (ALS) patients
have revealed variable results on specific tests, despite a similar overall
cognitive profile of predominantly executive dysfunction with some evidence of
memory impairment. The most striking and consistent deficit is found using tests
of verbal fluency. The current investigation explored why verbal fluency is
particularly sensitive to the impairment in ALS, by investigating some of the
underlying cognitive processes: (i) intrinsic response generation; (ii)
phonological loop functions; and (iii) simple word retrieval. Twenty-two ALS
patients and 25 healthy controls were investigated. The battery included: (i)
written and spoken letter-based fluency, category fluency, design fluency; (ii)
the Phonological Similarities effect and Word Length Effect; and (iii)
computerised sentence completion and confrontational naming. The tests were
designed to control for motor speed and to accommodate for the range of
disabilities that are present in ALS patients. Significant impairments were found
on some tests of intrinsic response generation, namely the Written Verbal Fluency
Test, Category Fluency Test (generation of animal names) and Design Fluency Test.
Phonological loop functions appeared to be intact with evidence of both the
Phonological Similarities and Word Length Effects, but the ALS patients displayed
significantly reduced working memory capacity. No deficits were found on tests of
simple word retrieval. The findings indicate that verbal fluency impairments in
ALS patients result from a higher order dysfunction, implicating deficits in the
supervisory attentional system or central executive component of working memory,
and are not caused or exaggerated by an impairment in phonological loop functions
or in primary linguistic abilities. The study also demonstrates the importance of
controlling for differences in motor speed, which may have served to exaggerate
the presence of cognitive deficits in ALS patients reported by some other
studies.
PMID- 10689050
TI - The effects of repetition on allocation of study time and judgements of learning
in Alzheimer's disease.
AB - Greene et al. [12] suggest that Alzheimer's disease (AD) patients approach
repeated trials in a learning test as if they are single unrelated trials.
Previous research [7] indicates that AD patients do not have explicit memory for
item repetition when asked at test how many times a word was presented, but they
do show benefits of repeated presentation in implicit tasks. In this experiment
we examine metacognitive judgements made during study for repeated items. It was
hypothesised that a lack of awareness of repetition may exacerbate the episodic
memory impairment found in AD. To explore this, two measures of metamemory were
taken for items presented once, twice or three times in a list: judgements of
learning (JOLs), which are a declaration of how well an item has been learned,
and recall readiness, which is the study time allocated by participants to ensure
proficient learning of an item. With repetition, age matched controls made recall
readiness judgements more quickly and reported higher JOLs. The AD patients
showed faster recall readiness, but did not alter their JOLs. This suggests a
dissociation in the AD group between judgements of learning and the allocation of
study time. We discuss the implications for theories of the learning deficit in
AD, and the use of metamemory measurements in clinical populations.
PMID- 10689051
TI - Cognitive and vestibulo-proprioceptive components of spatial ability in
Parkinson's disease.
AB - Visual-spatial deficits are often associated with Parkinson's Disease (PD).
Recent theories suggest that frontal-basal ganglionic dysfunction affects
cognition in PD. Although this hypothesis does not entirely explain spatial
deficits in PD, the inappropriate utilization of cues associated with executive
dysfunction may induce spatial deficits. Alternatively, the vestibular system is
also involved in spatial cognition, and vestibular dysfunction may affect visual
spatial ability in PD. To test these hypotheses, we administered the Water Jar
Test, while perturbing vestibulo-proprioceptive input. Non-demented PD patients
were significantly less accurate than controls in judging horizontal, and
appeared to inappropriately utilize cues. No group effect was found for head
tilt. These findings suggest the visual-spatial difficulties seen in PD are
related to executive dysfunction that is associated with a disruption of the
frontal-basal ganglionic and frontal-parietal systems.
PMID- 10689052
TI - Intrusion errors in numerical transcoding by Alzheimer patients.
AB - The errors made by brain-damaged patients when they attempt numerical transcoding
tasks have recently been considered as a possible aid to early diagnosis of the
disease. The transcoding errors of 20 Alzheimer's disease patients are described,
and the incidence of each kind of error compared with norms from healthy
subjects. Tegner and Nyback (Tegner R, Nyback H. "To hundred and twenty4our": a
study of transcoding in dementia. Acta Neurologica Scandinavia 1990; 81: 177-178)
reported that Alzheimer patients often express numerical information in a mixture
of verbal and digital codes and Kessler and Kalbe (Kessler J, Kalbe E. Written
numerical transcoding in patients with Alzheimer's disease. Cortex 1996; 32: 755
761) suggested that such intrusions of the source code into the target code may
not only be largely absent from the responses of the healthy population, but also
from the transcoding operations of patients with other kinds of brain damage,
such as aphasia. It was found that intrusion errors occurred much more frequently
in the transcoding protocols of some of the Alzheimer patients than they do in
those of healthy subjects. On the other hand, they were entirely absent from the
protocols of other Alzheimer patients. The implications of the findings for the
early diagnosis of Alzheimer's disease are discussed, and the phenomenon of
intrusion errors is considered in terms of some of the models of arithmetical
processing that have been proposed.
PMID- 10689053
TI - Attentional grasp in far extrapersonal space after thalamic infarction.
AB - Studies of animals and humans with focal brain damage suggest that attention in
near and far extrapersonal space may be mediated by anatomically separate
systems. Thalamic lesions have been associated with spatial neglect, but whether
asymmetric attention specific to near or far space occur after thalamic damage
has not been explored. It is also unclear if thalamic injury can induce
contralesional defective response inhibition. We tested a woman with a left
thalamic infarction who reported that, when driving, she had a tendency to veer
towards people or objects on the right side of the road. Our patient and four
controls performed a line bisection task with a laser pointer in near and far
extrapersonal space. The experimenter marked each bisection either from the right
of the presented line (right-distractor, RD) or the left (left-distractor, LD).
RD and LD trials were pseudo-randomized. Our patient performed similarly to
controls (mean -0.7 mm, controls -0.6 mm) on the line bisection task in near
space. In far space she erred significantly rightward compared to her performance
in near space (p<0.001). Controls performed similarly in near and far space. The
experimenter position did not affect our patient's performance on near line
bisections, nor did controls demonstrate a distractor effect for the near
condition. In the far condition, however, our patient showed a significant
distractor effect (LD -3.3 mm, RD 35.3 mm, p<0.001). Controls also demonstrated a
distractor effect in the far condition (LD -6.4 mm, RD 0.7 mm, p<0.01), though of
much smaller magnitude. Our results suggest that frontal-thalamic systems
regulating visual attention may be disrupted by thalamic infarction. Such damage
may produce an attentional grasp specific to far extrapersonal space.
PMID- 10689054
TI - Variability not ability: another basis for performance decrements in neglect.
AB - OBJECTIVE: To determine reaction time (RT) and its variability, as a function of
horizontal spatial position, in subjects with neglect. BACKGROUND: In neglect,
performance is frequently reported a as mean and a decreased ability to perform
the task inferred by comparison to control groups. Few studies have examined how
consistency and optimal performance relate to spatial neglect. METHODS: Ten
subjects with brain damage, five with and five without spatial neglect, were
assessed on a RT task. Subjects responded by pushing a computer key to the onset
of a white square appearing on a black screen. The locations of stimuli were
randomly varied along the horizontal meridian. RESULTS: For three of five neglect
subjects, optimal RT showed no or little relation to horizontal location. Four of
five neglect subjects demonstrated an increased variability in RT that correlated
with spatial position and which was not present in our brain damaged subjects
without neglect. The relationship was not an artifact of left sided stimuli, in
general, being processed differently. For the two neglect subjects with the most
trials, a significant correlation between RT variability and spatial position
existed for left-sided trials alone. Increased variability was not a consequence
of simply looking left proportionately less often, nor could a model of multiple
compensatory systems operating in parallel explain the enhanced variability.
Neither hemianopsia alone nor brain damage per se could account for the spatial
modulation of RT variability. CONCLUSIONS: That neglect subjects perform the RT
task normally on some trials, even in their 'neglected field', challenges the
notion that neglect must reflect an irreparably damaged cognitive system.
Performance decrements in neglect can reflect an inability to consistently detect
and respond. Evaluating optimal performance and variability of performance can
indicate if a capacity has been lost absolutely or merely degraded such that
normal performance cannot be sustained.
PMID- 10689055
TI - Auditory agnosia and auditory spatial deficits following left hemispheric
lesions: evidence for distinct processing pathways.
AB - Auditory recognition and auditory spatial functions were studied in four patients
with circumscribed left hemispheric lesions. Patient FD was severely deficient in
recognition of environmental sounds but normal in auditory localisation and
auditory motion perception. The lesion included the left superior, middle and
inferior temporal gyri and lateral auditory areas (as identified in previous
anatomical studies), but spared Heschl's gyrus, the acoustic radiation and the
thalamus. Patient SD had the same profile as FD, with deficient recognition of
environmental sounds but normal auditory localisation and motion perception. The
lesion comprised the postero-inferior part of the frontal convexity and the
anterior third of the temporal lobe; data from non-human primates indicate that
the latter are interconnected with lateral auditory areas. Patient MA was
deficient in recognition of environmental sounds, auditory localisation and
auditory motion perception, confirming that auditory spatial functions can be
disturbed by left unilateral damage; the lesion involved the supratemporal region
as well as the temporal, postero-inferior frontal and antero-inferior parietal
convexities. Patient CZ was severely deficient in auditory motion perception and
partially deficient in auditory localisation, but normal in recognition of
environmental sounds; the lesion involved large parts of the parieto-frontal
convexity and the supratemporal region. We propose that auditory information is
processed in the human auditory cortex along two distinct pathways, one lateral
devoted to auditory recognition and one medial and posterior devoted to auditory
spatial functions.
PMID- 10689056
TI - Orienting attention in time: behavioural and neuroanatomical distinction between
exogenous and endogenous shifts.
AB - Temporal orienting of attention is the ability to focus resources at a particular
moment in time in order to optimise behaviour, and is associated with activation
of left parietal and premotor cortex [Coull, J. T., Nobre, A. C. Where and when
to pay attention: the neural systems for directing attention to spatial locations
and to time intervals as revealed by both PET and fMRI. Journal of Neuroscience,
1998, 18, 7426-7435]. In the present experiment, we explored the behavioural and
anatomical correlates of temporal orienting to foveal visual stimuli, in order to
eliminate any spatial attention confounds. We implemented a two-way factorial
design in an event-related fMRI study to examine the factors of trial validity
(predictability of target by cue), length of delay (cue-target interval), and
their interaction. There were two distinct types of invalid trial: those where
attention was automatically drawn to a premature target and those where attention
was voluntarily shifted to a delayed time-point. Reaction times for valid trials
were shorter than those for invalid trials, demonstrating appropriate allocation
of attention to temporal cues. All trial-types activated a shared system,
including frontoparietal areas bilaterally, showing that this network is
consistently associated with attentional orienting and is not specific to spatial
tasks. Distinct brain areas were sensitive to cue-target delays and to trial
validity. Long cue-target intervals activated areas involved in motor
preparation: supplementary motor cortex, basal ganglia and thalamus. Invalid
trials, where temporal expectancies were breached, showed enhanced activation of
left parietal and frontal areas, and engagement of orbitofrontal cortex
bilaterally. Finally, trial validity interacted with length of delay. Appearance
of targets prematurely selectively activated visual extrastriate cortex; while
postponement of target appearance selectively activated right prefrontal cortex.
These findings suggest that distinct brain areas are involved in redirecting
attention based upon sensory events (bottom-up, exogenous shifts) and based upon
cognitive expectations (top-down, endogenous shifts).
PMID- 10689057
TI - The neuroanatomical correlates of route learning impairment.
AB - Recent functional imaging studies of topographical learning point to the
participation of a large network of cortical and subcortical regions.
Nevertheless, areas which are crucial remain poorly specified due to the absence
of group studies of subjects with focal lesions distributed throughout the brain.
We assessed the ability of 127 subjects with stable, focal lesions to learn a
complex real-life route, a critical aspect of topographical functioning. Results
indicated that impairment in route learning was highly associated with damage to
medial occipital and posterior parahippocampal cortices in either hemisphere, the
right hippocampus, and the right inferotemporal region. Impairment was seen among
86% of the subjects with damage to any these regions, in contrast to impairment
among 31% of subjects with lesions in other regions. The importance of medial
occipitotemporal cortices bilaterally and right inferotemporal cortex likely
reflects the critical role of the ability to quickly and accurately perceive and
learn multiple topographical scenes. The importance of the right (and probably
left) posterior parahippocampal gyrus and of the right hippocampus likely
reflects their critical, distinctive roles forming an integrated representation
of the extended topographical environment (i.e., the appearance of places and
spatial relationships between specific places), and consolidating that
representation into multifaceted contextual knowledge of the environment.
PMID- 10689058
TI - Understanding memory for faces in Parkinson's disease: the role of configural
processing.
AB - It has previously been reported that unfamiliar face recognition memory is
impaired in Parkinson's disease (PD) [(Dewick, H. C., Hanley, J. R., Davies, A.
D. M., Playfer, J. R. & Turnbull, C. J., Perception and memory for faces in
Parkinson's disease. Neuropsychologia, 1991, 29, 785-802), (Haeske-Dewick, H. C.,
Are perception and memory for faces influenced by a specific age at onset factor
in Parkinson's disease? Neuropsychologia, 1996, 34, 315-320), (Levin, B. E.,
Llabre, M. M. & Weiner, W. J., Cognitive impairments associated with early
Parkinson's disease. Neurology, 1989, 39, 557-561)]. In the work reported here,
we consider the possible mechanisms that might underlie this impairment. 28 PD
patients and 28 controls were given a two-part test of recognition memory for
words and faces, and two perceptual tests to measure their configural and
componential processing ability. We found that PD patients were significantly
worse than controls on the recognition memory test for faces, but not when the
stimuli were words. In addition, PD patients were significantly impaired relative
to controls on the closure test (FCT) used to measure configural processing, but
there was no difference between the two groups on a test of componential
processing ability. Multiple regression analyses revealed that even after
accounting for the influence of age, intelligence and level of depression,
configural processing ability was the important predictor of unfamiliar face
recognition memory in Parkinson's disease. There was no effect of Parkinson's
disease specific variables on either face recognition or FCT performance. In
addition, some recently diagnosed patients were poor at face recognition. It is
suggested that face configuration skills may be affected very early in the course
of Parkinson's disease, and that this may be connected to the fact that
considerable nigrostriatal degeneration and alteration in brain neurotransmitter
levels occur before the clinical symptoms of PD appear.
PMID- 10689059
TI - The cognitive and neuroanatomical correlates of multitasking.
AB - Patients who show the "strategy application disorder" can show deficits
restricted to situations requiring multitasking, but the precise neuroanatomical
and cognitive correlates of this problem have been rarely investigated. In this
study, 60 people with circumscribed cerebral lesions and 60 age- and IQ-matched
controls were given a multitasking procedure which allowed consideration of the
relative contributions of task learning and remembering, planning, plan-following
and remembering one's actions to multitasking performance. Lesions to the left
posterior cingulate and forceps major regions gave deficits on all measures
except planning. Remembering task contingencies after a delay was also affected
by lesions in the region of the left anterior cingulate, and rule-breaking and
failures of task switching were additionally found in people with lesions
affecting the medial and more polar aspects of Brodmann's areas 8, 9 and
especially 10. Planning deficits were associated with lesions to the right
dorsolateral prefrontal cortex (RDLPFC). A theory of the relationships between
the cognitive constructs underpinning multitasking was tested using structural
equation modelling. The results suggest that there are three primary constructs
that support multitasking: retrospective memory, prospective memory, and
planning, with the second two drawing upon the products of the first. It is
tentatively suggested that the left anterior and posterior cingulates together
play some part in the retrospective memory demands, while the prospective memory
and planning components make demands on processes supported by the left areas 8,
9 and 10 and the RDLPFC respectively.
PMID- 10689060
TI - Processing of spatial locations: hemispace effects during encoding but not
recall.
AB - Traditionally, functional differences in the visual modality between the two
hemispheres are investigated by tachistoscopic procedures. In these experiments,
the stimuli reach the contralateral hemisphere first, and results are commonly
interpreted on the basis of neuroanatomical access models. However, numerous
studies demonstrated that the hemispace where the stimulus is perceived also
plays a critical role in producing laterality effects ("hemispace effects"). In
the present experiment, subjects were instructed to memorize the relative spatial
positions of six figures horizontally aligned on a presentation board. The
presentation board was located either to the left, to the right or in front of
the subjects (left, right and central learning positions). During a recall phase,
each figure was presented in the center of a computer screen and subjects were
required to indicate by keypress whether a figure had been located in the left or
right half of the presentation board. As in the learning phase, the computer
screen was located to the left, the right or in front of the subjects (left,
right and central recall positions). We found that the positions of the figures
initially memorized in the left hemispace were recalled faster than figures
initially memorized in the right hemispace. Hemispatial position during recall
had no effect on performance. These results are discussed with respect to
hemispheric specialization and theories of hemispace effects.
PMID- 10689061
TI - On the neurobiology of creativity. Differences in frontal activity between high
and low creative subjects.
AB - The aim was to investigate the relationship between creativity and hemispheric
asymmetry, as measured by regional cerebral blood flow (rCBF). Two groups, each
consisting of 12 healthy male subjects, who got either very high or low scores on
a creativity test, were pre-selected for the rCBF investigation. rCBF was
measured during rest and three verbal tasks: automatic speech (Auto), word
fluency (FAS) and uses of objects (Brick). State and trait anxiety inventories
were answered after the rCBF measurements. Intelligence tests were also
administered. It was predicted that highly creative subjects would show a
bilateral frontal activation on the divergent thinking task (Brick), while low
creative subjects were expected to have a unilateral increase. Calculations were
made of differences in blood flow levels between the FAS and the Brick
measurements in the anterior prefrontal, frontotemporal and superior frontal
regions. In accordance with our prediction, repeated measure-ANOVAs showed that
the creativity groups differed significantly in all three regions. The highly
creative group had increases, or unchanged activity, while the low creative group
had mainly decreases. The highly creative group had higher trait anxiety than the
low creative group. On the intelligence tests the low creative group was superior
both on logical-inductive ability and on perceptual speed, while the groups were
equal on verbal and spatial tests. The results are discussed in terms of
complementary functions of the hemispheres.
PMID- 10689062
TI - Line bisection performances of 650 normal children.
AB - When bisecting lines, an important number of brain damaged patients tend to place
their bisection marks in the hemispace ipsilateral to their lesion. Biases have
also been reported in normal adults. In vertical bisection both patients and
normal subjects present with upward shifts, although a downward displacement may
occur eventually. Surprisingly, little is known on line bisection (LB) in normal
or brain damaged children. A total of 650 subjects, aged 7-12 years, performed a
horizontal and vertical LB task with their preferred hand. Asymmetry indices
(AIs) were used to measure directional bias. Unsigned AIs served to evaluate
accuracy and mastery of the LB skill. In vertical bisection a general and
significant upward bias was found, whereas in horizontal bisection subject
(gender, handedness, utilized hand, age) and stimulus variables (orientation,
length, position) yielded significantly different AIs. Although with increasing
age significantly increasing accuracy was observed, none of the participating
children mastered LB to mathematical precision. Differences in IQ-level and
attention test score did not yield significantly different AIs. Impact from
reading proficiency could not be demonstrated. It is suggested that stimulus
length effect results are compatible with the Halligan and Marshall [Halligan,
P., and Marshall, J. Toward a principled explanation of unilateral neglect.
Cognitive Neuropsychology, 1994, 11, 167-206] model of hemispatial neglect.
Moreover, data may support the hypothesis of greater hemispheric specialization
of visuo-spatial skills in boys than in girls.
PMID- 10689063
TI - Axis-based grouping reduces visual extinction.
AB - We examined the effects on extinction of grouping by collinearity of edges and
grouping by alignment of internal axes of shapes, in a patient (GK) with
simultanagnosia following bilateral parietal brain damage. GK's visual extinction
was reduced when items (equilateral triangles and angles) could be grouped by
base alignment (i.e., collinearity) or by axis alignment, relative to a condition
in which items were ungrouped. These grouping effects disappeared when inter-item
spacing was increased, though factors such as display symmetry remained constant.
Overall, the results suggest that, under some conditions, grouping by alignment
of axes of symmetry can have an equal beneficial effect on visual extinction as
edge-based grouping; thus, in the extinguished field, there is derivation of axis
based representations from the contours present.
PMID- 10689064
TI - Factors affecting the fermentative lactic acid production from renewable
resources(1).
AB - Parameters affecting the fermentative lactic acid (LA) production are summarized
and discussed: microorganism, carbon- and nitrogen-source, fermentation mode, pH,
and temperature. LA production is compared in terms of LA concentration, LA yield
and LA productivity. Also by-product formation and LA isomery are discussed.
PMID- 10689065
TI - Protease-catalyzed tripeptide (RGD) synthesis.
AB - The tripeptide Bz-Arg-Gly-Asp(-OMe)-OH was synthesized by enzymatic method. Bz
Arg-Gly-OEt was synthesized by trypsin in ethanol containing 0.1 M Tris/HCl
buffer (pH 8.0), and then H-Asp(-OMe)(2) was incorporated into the Bz-Arg-Gly-OEt
using chymopapain in 0.25M CHES/NaOH buffer (pH = 9.0, EDTA 10 mM). The yield of
Bz-Arg-Gly-OEt and Bz-Arg-Gly-Asp(-OMe)-OH were 80% and 70% using 1M Bz-Arg-OEt
and 0.5M Bz-Arg-Gly-OEt, respectively. For Bz-Arg-Gly-OEt synthesis reaction at
high concentrations of the substrates, the buffer content in ethanol was a key
factor to determine the optimal reaction condition. In Bz-Arg-Gly-Asp(-OMe)-OH
synthesis reaction, the yield was low in organic solvent due to various side
products such as Bz-Arg-OH, Bz-Arg-Gly-OH, and Bz-Arg-Gly-Asp(-OMe)-Asp(-OMe)-OH,
suggesting that chymopapain has a very broad substrate specificity of the S(1)
site. The Bz-Arg-Gly-Asp(-OMe)-OH synthesis rate and its yield were dramatically
elevated and the side reactions were reduced using only the CHES/NaOH buffer (pH
= 9.0, EDTA 10 mM) as a reaction media. The final product Bz-Arg-Gly-Asp(-OMe)-OH
was identified to be formed via C-terminal hydrolysis of Bz-Arg-Gly-Asp(-OMe)(2)
after the nucleophile, H-Asp(-OMe)(2), was added.
PMID- 10689066
TI - Pectinase in papermaking: solving retention problems in mechanical pulps bleached
with hydrogen peroxide.
AB - Treatment with the enzyme pectinase has been reported to lower the cationic
demand of thermomechanical pulp (TMP) bleached with alkaline peroxide in the
laboratory. We have extended this discovery to bleached TMP produced
industrially, and shown that commercial enzyme preparations can treat pulp within
15 min at the temperature and pH values prevalent in paper mills. About half of
the cationic demand in the bleached pulp can be destroyed by pectinase. Dynamic
drainage jar experiments show that the enzyme treatment improves the
effectiveness of several cationic polymers to increase retention of fines and
filler particles. It does not increase retention in the absence of retention aids
or with nonionic polymers, and does not damage the strength properties of the
pulp. Pectinase could be easily incorporated into paper machine stock preparation
systems to lower the charges of cationic retention aids needed in furnishes
containing peroxide-bleached mechanical pulp.
PMID- 10689067
TI - Influence of alcohol concentration on lipase-catalyzed enantioselective
esterification of racemic naproxen in isooctane: under controlled water activity*
AB - According to a previous study, alcohol concentration influences the enantiomeric
ratio and initial rate of Candida cylindracea lipase-catalyzed enantioselective
esterification of racemic 2-(6-methoxy-2-naphthyl) propionic acid in microaqueous
isooctane in a similar manner. Such an influence might be attributed to the
different water partitioning coefficients. In this work, we performed enzymatic
resolutions in controlled water activity atmospheres, thereby separating the
influence of alcohol concentrations from the effect of water partitioning.
Despite this constant water activity condition, a similar dependence of
enantiospecificity and initial rate on the concentration of acyl acceptor (n
butanol) was also found. This finding suggests that the alcohol concentration
influences enzyme performance, but not because it strips water from the enzyme.
The unexpected observations imply that an undetermined factor must be considered
when the enzymatic resolution is performed in nonconventional media.
PMID- 10689068
TI - Optimization of isoamyl acetate production by using immobilized lipase from Mucor
miehei by response surface methodology.
AB - Immobilized lipase from Mucor miehei was employed for the esterification of
isoamyl alcohol with acetic acid in n-heptane solvent. The important process
variables studied were enzyme/substrate (E/S) ratio, alcohol (acid)
concentration, and incubation period. Based on Box-Behnken design of experiments,
a second order response function was developed. The percentage esterification
increased with both E/S ratio and time and decreased with alcohol (acid)
concentration. The model indicated optimum conditions for maximum esterification
ranging from 20 to 99.6% in the alcohol (acid) concentration range of 0.031 to
0.3 M for a range of E/S ratios 8.33 to 50 g/mol, which were in good agreement
with the experimental yields.
PMID- 10689069
TI - Improvement of the enantioselectivity of lipase-catalyzed naproxen ester
hydrolysis in organic solvent.
AB - A method is presented to improve the enantioselectivity of lipase-catalyzed
hydrolysis of naproxen methyl ester in water-saturated isooctane. It is shown
that coupling of the enantioselective hydrolysis of Naproxen methyl ester with
the photo-dissociation methanol leads to the photocatalytic conversion of
methanol into water, by which the equilibrium constant (K) of the lipase
catalyzed hydrolysis was changed. The equilibrium yield and enantiomeric excess
are increased. Because the lipase would not dissolve in the organic solvent, it
was adsorbed on photocatalyst particles, which may facilitate the isolation of
enzyme from reaction system.
PMID- 10689070
TI - Enzymatic synthesis of cephalothin by penicillin G acylase*
AB - Enzymatic synthesis of cephalothin from 7-aminocephalosporanic acid (7-ACA) and
amide derivatives of 2-thienylacetic acid (2-TA) using penicillin G acylase (pen
G acylase) was studied. Two amide derivatives of 2-TA namely 2-thienylacetamide
(2-TAA) and 2-thienylacetohydroxamic acid (2-TAH) were used in this study. The
main reason for choosing amide but not the methyl ester derivative of 2-TA for
the enzymatic synthesis was to increase their solubilities in water. The
solubility of 2-TA methyl ester (2-TAM), 2-TAA, and 2-TAH in aqueous solution is
8 +/- 0.05 mM, 87 +/- 0.75 mM and 120 +/- 1.65 mM, respectively. Enzymatic
conversion of 2-TAH to cephalothin yielded side products but they were not found
in the conversion of 2-TAA to cephalothin. The side products were derived from
reactions between hydroxyamine and 7-ACA. The effects of pH, temperature, initial
substrate concentrations and reaction time on the conversion of 2-TAA and 7-ACA
to cephalothin were examined. The optimum reaction condition was determined at pH
6.5 and 10 approximately 15 degrees C. The best conversion yield of 72% was
obtained when the initial concentration of 2-TAA and 7-ACA was at 0.4 M and 0.1
M, respectively. Furthermore, a one-step method was developed to purify
cephalothin from the enzymatic reaction mixture with the purity of 91% and the
recovery yield of 96%.
PMID- 10689071
TI - Cloning of a wide-spectrum amidase from Bacillus stearothermophilus BR388 in
Escherichia coli and marked enhancement of amidase expression using directed
evolution*
AB - A 1.6-kb DraI-HindIII DNA fragment from Bacillus stearothermophilus BR388
chromosomal DNA encoding a wide-spectrum amidase was cloned into Escherichia coli
DH5alpha. With acrylamide substrate, the amidase showed maximum activity at 55
degrees C, pH 7.0, and 0.12-M substrate, and demonstrated significant activity in
1-M acrylamide. A mutant prepared by PCR-based random mutagenesis of a 1.65 kb
segment of B. stearothermophilus BR388 chromosomal DNA containing the amidase
gene had two adenine bases replaced with guanine, resulting in a single primary
structure alteration of His26 into Arg. This mutant demonstrated a 23-fold
increase in amidase activity compared to wild-type, which is attributed to
increased amidase gene transcription.
PMID- 10689072
TI - Surfactant-protease complex as a novel biocatalyst for peptide synthesis in
hydrophilic organic solvents*
AB - The peptide synthesis from N-acetyl-L-phenylalanine ethyl ester with alaninamide
catalyzed by a surfactant-protease complex has been performed in anhydrous
hydrophilic organic solvents. Proteases derived from various sources were
converted to surfactant-coated complexes with a nonionic surfactant. The
surfactant-subtilisin Carlsberg (STC) complex had a higher enzymatic activity
than the other protease complexes and the initial reaction rate in tert-amyl
alcohol was 26-fold that of STC lyophilized from an optimum aqueous buffer
solution. Native STC hardly catalyzed the same reaction. The addition of water to
the reaction medium activated the lyophilized STC, however, the reaction rate was
much lower than that of the STC complex, and a hydrolysis reaction preferentially
proceeded. The STC complex exhibited a high catalytic activity in hydrophilic
organic solvents (e.g. tertiary alcohol). The addition of dimethylformamide as a
cosolvent improved the solubility of amino acid amides and further activated the
STC complex due to the water mimicking effect. When hydrophilic amino acid amides
were employed as an acyl acceptor, the peptide formation proceeded efficiently
compared to that using hydrophobic substrates. The surfactant-STC complex is a
powerful biocatalyst for peptide synthesis because the STC complexes display a
high catalytic activity in anhydrous hydrophilic organic solvents and did not
require the excess amount of water. Thus the side (hydrolysis) reaction is
effectively suppressed and the yield in the dipeptide formation is considerably
high.
PMID- 10689073
TI - The relative importance of intracellular proteolysis and transport on the yield
of the periplasmic enzyme penicillin amidase in Escherichia coli*
AB - Intracellular proteolysis is an important mechanism for regulating the level of
the periplasmic enzyme penicillin amidase in Escherichia coli. Evidence is
presented that the active enzyme is localized in the periplasmic space and
maturation of pro-enzyme occurs during transport through the cytoplasmic membrane
or rapidly after its entrance in the periplasm. The rate constants of the
transport through cytoplasmic membrane and of the intracellular proteolysis were
estimated to be 0.01 h and 0.5 h, respectively. This indicates that more than 90%
of the synthesized pre-pro-enzyme is lost by intracellular proteolysis occurring
in the cytoplasm.
PMID- 10689074
TI - Stability and stabilization of potential feed additive enzymes in rumen fluid*
AB - Four commercial preparations of fibrolytic enzymes, from Irpex lacteus,
Trichoderma viride, Aspergillus niger, and a mixture designed to be similar to
the I. lacteus extract, were incubated in vitro with digesta taken from the rumen
of sheep receiving a grass hay/concentrate diet, and the survival of major enzyme
activities was measured. Some activities, including the beta-1,4-endoglucanase
and xylanase from the extract derived from Aspergillus niger, were stable for at
least 6 h in rumen fluid. The same activities in the other extracts also retained
substantial activity for several hours. beta-Glucosidase and beta-xylosidase
activities were much more labile, most being almost completely destroyed after 1
h, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that
most proteins in the extracts were digested extensively after up to 7 h of
incubation. Adding bovine serum albumin (0.5 g/l) to the incubation increased the
half-life of Trichoderma viride beta-glucosidase activity from less than 0.5 h to
3 h. Proteins extracted from plant materials, particularly the soybean 7S
globulin fraction, also conferred protection from proteolytic breakdown, but none
was as effective as bovine serum albumin. It was concluded that the stability of
most fibrolytic enzymes in rumen fluid is not likely to be a limiting factor in
the use of enzymes as feed additives for ruminants; but if the enzymes are not
stable, means can be found for their stabilization.
PMID- 10689075
TI - Purification and properties of three endo-beta-1,4-xylanases produced by
Streptomyces sp. strain S38 which differ in their ability to enhance the
bleaching of kraft pulps*(2).
AB - In the presence of xylan, Streptomyces sp. strain S38 secretes three xylanases
(Xyl1, Xyl2, and Xyl3) that were purified to protein homogeneity and
characterized. When used in bleach boosting tests on kraft hardwood and softwood,
Xyl1, a family-11 enzyme, was more effective than Xyl2 and Xyl3 that belonged to
family-10. Xyl1 was fully responsible for the biodelignification potential of the
culture supernatants with a minimal effective amount of 10 IU per gram of dry
pulp for both softwood and hardwood pulp. Complete conventional CEDED bleaching
sequences showed that enzymatic pretreatment (20 IU/g dry pulp) could result in
active chlorine savings of 8.6 and 4.9 kg/ton of dry pulp with hardwood and
softwood, respectively. The purified enzymes were totally devoid of cellulase
activity on CM-cellulose and their activities were optimal at about 60 degrees C
and pH 6. Moreover, the V(max) value of Xyl1 at 50 degrees C measured on
birchwood xylan (5,700 umoles/min/mg prot.) was significantly higher than those
of Xyl2 and Xyl3 whereas their K(m) values were similar. Their half-lives at 50
degrees C were larger than 16 h but sharply decreased at 60 degrees C where the
family-11 Xyl1 was less stable (t(1/2)(60 degrees C) = 10 min) than both family
10 enzymes Xyl2 (t(1/2)(60 degrees C) = 30 min) and Xyl3 (t(1/2)(60 degrees C) =
70 min).
PMID- 10689076
TI - Purification and characterization of a moderately thermostable xylanase from
Bacillus sp. strain SPS-0.
AB - A Bacillus spp. strain SPS-0, isolated from a hot spring in Portugal, produced an
extracellular xylanase upon growth on wheat bran arabinoxylan. The enzyme was
purified to homogeneity by ammonium sulfate precipitation, anion exchange, gel
filtration, and affinity chromatography. The optimum temperature and pH for
activity was 75 degrees C and 6.0. Xylanase was stable up to 70 degrees C for 4 h
at pH 6.0 in the presence of xylane. Xylanase was completely inhibited by the
Hg(2+) ions. beta-Mercaptoethanol, dithiothreitol, and Mn(2+) stimulated the
xylanase activity. The products of birchwood xylan hydrolysis were xylose,
xylobiose, xylotriose, and xylotetraose. Kinetic experiments at 60 degrees C and
pH 6.0 gave V(max) and K(m)values of 2420 nkat/mg and 0.7 mg/ml.
PMID- 10689077
TI - Molecular basis of glucoamylase overproduction by a mutagenised industrial strain
of Aspergillus niger.
AB - We have compared a mutagenized strain of Aspergillus niger (S1), used
industrially for glucoamylase production, and a related low glucoamylase
producing strain (S2) with a laboratory strain of A. niger (AB4.1). Our aim was
to assess the properties of S1 in relation to the laboratory strain and to
account at the molecular level for the basis of its glucoamylase overproduction.
Both S1 and S2 have similar multiple copies of the glucoamylase-encoding gene
(glaA) but only S1 has enhanced glaA transcript and glucoamylase levels compared
to AB4.1 that has a single copy of the glaA gene. Glucoamylase production by S1
and AB4.1 was repressed by xylose and induced by starch but, in S2, remained
unaffected by carbon source. S1 also secreted elevated levels of alpha-amylase
relative to both S2 and AB4.1 but the production of alpha-glucosidase was low in
all three strains. The gene encoding aspergillopepsin (pepA), an abundant
secreted aspartyl protease, was present as a single copy in all strains but no
aspergillopepsin could be detected by Western blotting in either S1 or S2 culture
supernatants. We conclude that A. niger strain improvement by mutagenesis and
screening for glucoamylase overproduction has led to glaA gene multiplication and
an expression defect in the pepA gene.
PMID- 10689078
TI - Metabolic engineering of Alcaligenes eutrophus through the transformation of
cloned phbCAB genes for the investigation of the regulatory mechanism of
polyhydroxyalkanoate biosynthesis.
AB - The regulatory mechanisms of the biosynthesis of in vivo poly-beta
hydroxybutyrate [PHB] and poly(3-hydroxybutyrate-3-hydroxyvalerate) [P(3HB-3HV)]
of Alcaligenes eutrophus were investigated by using various transformants with
enzyme activities that were modified through the transformation of cloned phbCAB
genes. The biosynthesis rates of PHB and P(3HB-3HV) were controlled by beta
ketothiolase and acetoacetyl-CoA reductase, and especially by beta-ketothiolase
condensing acetyl-CoA or propionyl-CoA. The contents of PHB and P(3HB-3HV) were
controlled by PHB synthase, polymerizing 3-hydroxybutyrate to PHB or 3
hydroxybutyrate and 3-hydroxyvalerate to P(3HB-3HV). The molar fraction of 3
hydroxyvalerate in P(3HB-3HV) was also closely connected with PHB synthase. This
may be due to the accelerated polymerization between 3-HB from glycolysis pathway
and 3-HV converted from propionate supplied as precursor. Enforced beta
ketothiolase and acetoacetyl-CoA reductase to PHB synthase tended to enlarge the
size of the PHB and P(3HB-3HV) granules, however, higher activity ratio of PHB
synthase to beta-ketothiolase and acetoacetyl-CoA reductase than parent strain
tended to induce the number of granules.
PMID- 10689079
TI - Production of lactic acid by Lactobacillus rhamnosus with vitamin-supplemented
soybean hydrolysate.
AB - Batch fermentation studies were performed to evaluate the potentials of a complex
nitrogen source, soybean, as an alternative to yeast extract for the economical
production of lactic acid by Lactobacillus rhamnosus. An enzyme-hydrolysate of
soybean meal, Soytone, with an adequate supplementation of vitamins was found to
be highly effective in supporting lactic acid production from glucose and
lactose. The effects of seven selected vitamins: d-biotin, pyridoxine, p
aminobenzoic acid, nicotinic acid, thiamine, pantothenic acid, and riboflavin, on
cell growth and lactic acid production were investigated to provide the basis for
the optimization of vitamin supplementation to minimize the cost. Pantothenic
acid was the most required compound while the other six vitamins were also
essential for high lactic acid productivity. As a result of the optimization, 15
g/l yeast extract could be successfully replaced with 19.3 g/l Soytone
supplemented with the vitamins, resulting in a production of 125 g/l lactic acid
from 150 g/l glucose. The volumetric productivity and lactate yield were 2.27
g/l/h and 92%, respectively, which were higher than those with 15 g/l yeast
extract. The raw material cost was estimated to be 21.4 cent/kg lactic acid,
which was only approximately 41% of that with yeast extract.
PMID- 10689080
TI - The kinetics of affinity-mediated cell-surface attachment.
AB - Data and a semi-empirical model are presented that describe the affinity
interaction of yeast cells with a Concanavalin A derivatised surface. The model
uses 3 parameters to describe the time course of cell attachment from a flowing
suspension of yeast cells, over a range of flow rates, and gives an effective
global fit to the data obtained. Further modifications allow the effects of a
soluble competitor (glucose) on binding to be quantified in terms of a saturation
effect, and an effective global fit is obtained. A comparison was made between
the relationship between steady-state attached fraction and applied shear with
similar data reported earlier (Ming, F. et al, 1998) for the detachment of pre
adsorbed cells. This shows that there is an order of magnitude difference between
the forces required to effect complete detachment in the two systems, and that
the nature of the relationship between shear and attached fraction is profoundly
different. The magnitude of this time-dependent stabilization might be explained
in terms of a progressive reorientation of cell relative to the surface such that
the number of bonds is maximized.
PMID- 10689081
TI - Recombinant Escherichia coli cell for d-p-hydroxyphenylglycine production from d
N-carbamoyl-p-hydroxyphenylglycine.
AB - Recombinant Escherichia coli cell containing D-amidohydrolase was employed to
convert D-N-carbamoyl-p-hydroxyphenylglycine (D-CpHPG) to D-p
hydroxyphenylglycine (D-pHPG). Biotransformations under pH 7 and 40 degrees C
allowed to complete conversion of D-CpHPG into D-pHPG. Under the same reaction
pH, the D-amidohydrolase activity of the cell in the phosphate buffer was higher
than that in the Tris buffer. The activity decreased with the increase of
phosphate buffer concentration. Instead of using buffer, the reaction pH
maintained constant at 7 by titrating with 1 N HCl resulted in a higher D-pHPG
production rate. Flocculating the cell suspension with chitosan and cross-linked
by glutaraldehyde made the cell recovery for repeated use much easier. Both the
cross-linking and (PMSF; a protease inhibitor) treatments could increase the cell
reusability and storage stability. However, the cross-linking decreased the D
amidohydrolase activity of the cell to about 50%. The D-amidohydrolase activities
of free and cross-linked cell were inhibited at substrate concentration higher
than 150 mM and 100 mM, respectively. The conversion of 150 mM D-CpHPG to D-pHPG
could be completed within 7 h for the free cell at the concentration of 10% (wet
weight/volume).
PMID- 10689082
TI - Immobilization of Nicotiana tabacum plant cell suspensions within calcium
alginate gel beads for the production of enhanced amounts of scopolin.
AB - Scopolin-producing cells of Nicotiana tabacum were immobilized within Ca-alginate
gel beads. Free cell suspensions accumulated scopolin within cytoplasmic
compartments and cell disruption was necessary to recover scopolin. On the
contrary, immobilized plant cells excreted considerable amounts of scopolin.
Scopolin diffused throughout the gel matrix and reached the culture media. A
large fraction of produced scopolin could then be recovered from the culture
medium without disrupting cells. Immobilized N. tabacum cells produced more
scopolin than free cell suspensions did (3.8 mg/g fresh weight biomass [into the
culture media] versus 0.2 mg/g fresh weight biomass [intracellular]). Variation
of the immobilization conditions revealed a marked influence on the behavior of
N. tabacum plant cells: production of scopolin and enhanced excretion, cell
growth, and morphological aspect of plant cell colonies. This excretion
phenomenon could be used advantageously at an industrial production level.
PMID- 10689083
TI - Production of flavour ketones in aqueous-organic two-phase systems by using free
and microencapsulated fungal spores as biocatalysts.
AB - The formation of 2-alkanones by free and microencapsulated P. roquefortii spores
in an aqueous-organic two-phase system was investigated by using substrates
supplied as a solution in decane. It was shown that the spores remained
catalytically active after entrapment within permeable polyamide microcapsules
and readily catalyzed the formation of 2-pentanone, 2-heptanone, and 2-undecanone
from short-chain alkyl esters of hexanoic, octanoic, and lauric acid,
respectively, with the rate of reaction being markedly dependent on the type and
concentration of the ester substrate used. In general, the optimal concentration
of the esters in decane was found to be much higher than that of the respective
fatty acid substrates and, in the case of alkyl dodecanoates, the
biotransformation could be carried out efficiently even in the absence of added
solvent. Further analysis revealed a significant difference in the reaction rates
observed with free and microencapsulated spores at 0.5 but not at 3.0 M methyl
dodecanoate, suggesting that at high substrate concentrations the
biotransformation was no longer limited by mass transfer.
PMID- 10689084
TI - 10-Oxo-trans-8-decenoic acid (ODA): production, biological activities, and
comparison with other hormone-like substances in Agaricus bisporus*
AB - The few well-characterized fungal growth-regulating substances include 10-oxo
trans-8-decenoic acid (ODA) and hercynine. This report deals with production and
tissue location of ODA. It also describes some biological activities of addition
of ODA, hercynine, and cytokinins on growth and postharvest morphogenesis of
Agaricus bisporus. Production of ODA in sporophore extracts was limited mainly by
oxygen availability and the possible occurrence of a competitive metabolic
pathway. Presumably synthesized within the stipe and skin tissues, ODA
accumulated in the gills. Mycelium growth rate on a potato-based medium was
significantly increased in the presence of ODA. Moreover, stipe lengthening was
slightly stimulated by 10 or 100 uM ODA. Although these findings were similar to
previous ones (Mau JL, Beelman RB, Ziegler GR. Phytochemistry 1992;31:4059-64),
ODA appeared poorly active in our assays and mycelium growth on asparagine
glucose medium was strongly inhibited by 200 uM ODA. In contrast with cytokinins
or hercynine, ODA did not speed up cap opening. Finally, tests carried out on
animal cells suggested a dose-dependent cytotoxic effect of ODA.
PMID- 10689085
TI - The influence of different biotic and abiotic elicitors on the production and
profile of tropane alkaloids in hairy root cultures of Brugmansia candida.
AB - Hairy root cultures of Brugmansia candida produce the tropane alkaloids
scopolamine and hyoscyamine. In an attempt to increase productivity, several
biotic and abiotic elicitors were tested. Salicylic acid increased significantly
the release of both alkaloids (2- to 12-fold) and it also acted positively on
specific production without altering the production profile. AgNO(3) increased
significantly scopolamine release (3-fold) and both alkaloid's accumulation (5-
to 8-fold) in the roots, thus favoring the production of scopolamine (up to 2
fold). The inhibiting effects of AgNO(3) and salicylic acid on ethylene could be
partly responsible for these responses. Yeast extract incremented the
intracellular content of both alkaloids (ca. 3-fold), but particularly increased
the release of scopolamine (7-fold). CaCl(2) had little effect on accumulation or
release of either alkaloid. CdCl(2) acted positively on the release of both
alkaloids (3- to 24-fold), but was highly detrimental to growth. Hairy roots of
B. candida are therefore susceptible to elicitation by biotic and abiotic
elicitors, with variations in the kinetics of induction and the extent of release
of each metabolite, thereby also exerting different effects on the alkaloid
profile.
PMID- 10689086
TI - Growth characteristics and chemical analysis of Psychotria carthagenensis cell
suspension cultures.
AB - Callus and cell suspension cultures of Psychotria carthagenensis have been
established in Gamborg's B5 medium supplemented, respectively, with 3% sucrose,
0.2 mg/l kinetin, and 1.0 mg/l 2,4-D and 2% sucrose, 2.0 mg/l 2,4-D, 0.2 mg/l
kinetin, and 50 mg/l cysteine. Suspension culture presented a typical growth
curve with the complete cycle of ca. 18 days and the maximum specific growth rate
(u) was 0.0099 day. The presence of different secondary metabolite pathways was
determined by measuring the enzyme activity of phenylalanine ammonia lyase (PAL),
tryptophan decarboxylase (TDC), strictosidine synthase (STR), strictosidine-beta
glucosidase (SG), and geraniol-10-hydroxylase (G10H). Activity could only be
measured for SG (14.55 pkatal/mg protein) and G10H (0.3 pkatal/mg protein).
Analysis of extracts from leaves, callus and cell suspension cultures
demonstrated the presence of two major triterpenes: beta-sitosterol and ursolic
acid.(2)
PMID- 10689087
TI - Reductive biotransformation of diethyl beta-, gamma- and delta
oxoalkylphosphonates by cells of baker's yeast.
AB - Enantiomerically pure hydroxyalkylphosphonates (over 95% of enantiomeric excess)
were obtained by asymmetric reductive biotransformation of a variety of
oxoalkylphosphonates catalyzed by baker's yeast. In the most cases the
biotransformations were carried out in water under aerobic conditions using whole
cell system. In the case of compounds unreactive under these conditions the
anaerobic reduction was applied.
PMID- 10689088
TI - Effect of temperature and enzyme origin on the enzymatic synthesis of
oligosaccharides.
AB - The aim of this research is to quantify the effect of temperature and enzyme
origin on the enzymatic synthesis of oligosaccharides. Quantification of these
effects is important because temperature and enzyme origin are important process
parameters. A kinetic model was used to describe the concentrations in time. The
kinetic parameters were determined by using data obtained in batch experiments at
various temperatures (20, 30, 40, and 50 degrees C) and by using beta
galactosidases from Bacillus circulans, Aspergillus oryzae, Kluyveromyces lactis,
and Kluyveromyces fragilis. The effect of temperature on the kinetic parameters
could be described with the Arrhenius equation, except for the inhibition
parameter. Slightly higher oligosaccharide yields were found at higher
temperatures. However, the influence of the initial lactose concentration was
much larger. The higher yield at higher temperatures is an additional advantage
when operating at high initial lactose concentrations and consequently elevated
temperatures. Clear differences between the beta-galactosidases were found
concerning amount, size, and type of oligosaccharides produced. The beta
galactosidase from B. circulans produced the most abundant amount, the most
different, and largest-sized oligosaccharides. The beta-galactosidases from
Kluyveromyces spp. produced mainly trisaccharides. The kinetic parameters for the
different enzymes were determined and differences were discussed.
PMID- 10689089
TI - Xanthan gum production under several operational conditions: molecular structure
and rheological properties*
AB - Xanthan gum production under several operational conditions has been studied.
Temperature, initial nitrogen concentration and oxygen mass transfer rate have
been changed and average molecular weight, pyruvilation and acetylation degree of
xanthan produced have been measured in order to know the influence of these
variables on the synthesised xanthan molecular structure. Also, xanthan gum
solution viscosity has been measured, and rheological properties of the solutions
have been related to molecular structure and operational conditions. The Casson
model has been employed to describe the rheological behaviour. The parameter
values of the Casson model, tau(0) and K(c), have been obtained for each
polysaccharide synthesised under different operational conditions. Both
pyruvilation and acetylation degrees and average molecular weight of xanthan
increase with fermentation time at any operating conditions. Xanthan molecules
with the highest average molecular weight have been obtained at 25 degrees C.
Nevertheless, at this temperature acetate and pyruvate radical concentration are
lowest. Nitrogen concentration in broth does not show any clear influence over
xanthan average molecular weight, although with high nitrogen source
concentration xanthan with low pyruvilation degree is produced.
PMID- 10689090
TI - Effect of threonine, cystathionine, and the branched-chain amino acids on the
metabolism of Zygosaccharomyces rouxii*
AB - Zygosaccharomyces rouxii is an important yeast in the formation of flavor in soy
sauce. In this study, we investigated the separate effects of exogenous
threonine, cystathionine, and the branched-chain amino acids on the metabolism of
Z. rouxii. The addition of these amino acids had significant effects on both Z.
rouxii growth and glycerol and higher alcohol production. It also seemed that Z.
rouxii displayed the Crabtree effect, which was independent of the added amino
acids. Furthermore, we investigated the regulation of the metabolism of alpha
ketobutyrate, which is a key-intermediate in Z. rouxii amino acid metabolism.
Threonine and cystathionine were introduced separately to stimulate the formation
rate of alpha-ketobutyrate and the branched-chain amino acids to inhibit its
conversion rate. Enzyme activities showed that these amino acids had a
significant effect on the formation and conversion rate of alpha-ketobutyrate but
that the alpha-ketobutyrate pool size in Z. rouxii was in balance all the time.
The latter was confirmed by the absence of alpha-ketobutyrate accumulation.
PMID- 10689091
TI - Detection of complement activity by using a polysaccharide-protected membrane.
AB - The complement system of mammalian blood is a nonspecific part of the immune
system involved in a number of disease conditions. We report the observation of
pore creation caused by its activation in blood applied to the front gel layer of
a bilayer membrane formed from dioleoylphosphatidyl choline and protected by a
polysaccharide gel. The pores were detected by measuring the DC conductivity
between nonblocking Ag/AgCl electrodes. The thickness of the protective gel was
approximately 100 um, and the complement response was seen within 3 min after
application of activator. The lifetime of such membranes is limited only by
hydrolysis of the phospholipid constituting the membrane. This easily prepared
system is suitable for examining the kinetics of complement component
interactions with inhibitors.
PMID- 10689092
TI - Production of polyunsaturated fatty acids by Pythium ultimum in solid-state
cultivation.
AB - The oleaginous fungus Pythium ultimum was cultivated on various solid substrates
in order to achieve fungal oil enriched in the polyunsaturated fatty acids
arachidonic acid and eicosapentaenoic acid. Cultivation parameters, such as
incubation temperature and time, substrate composition, and moisture were
optimized, so as to obtain as much as 3.5 mg eicosapentaenoic acid and 2.6 mg
arachidonic acid/g of wet substrate consisting of 28.5% pearled barley, 5.75%
spent malt grains, 5.75% linseed oil, and 60% nutrient solution.
PMID- 10689094
TI - Gender differences and individual variation in the immune system of the
scorpionfly Panorpa vulgaris (Insecta: Mecoptera).
AB - From investigations of the vertebrate immune system gender specific differences
in individual immunocompetence are well known. In general, females seem to
possess more powerful immune systems than males. In invertebrates, the situation
is much less clear. Therefore, we investigated the immune system of an
invertebrate species, the scorpionfly Panorpa vulgaris. We found a high degree of
individual variation in both traits studied, the lysozyme-like antibacterial
activity of hemolymph and the capacity for in vitro phagocytosis of artificial
particles. These two immune traits were positively correlated. As expected,
hemolymph derived from females had higher lysozyme-like activity and hemocytes
from females phagocytosed more particles. The difference in phagocytosis was
mainly based on higher total hemocyte counts and higher proportions of
phagocytically active cells in females, while the average number of ingested
particles per active phagocyte was not significantly different. The observed
gender differences are discussed in the context of reproductive strategies and
parasite-mediated sexual selection.
PMID- 10689095
TI - A survey of expressed genes in the leukocytes of Japanese flounder, Paralichthys
olivaceus, infected with Hirame rhabdovirus.
AB - We constructed a cDNA library of Japanese flounder, Paralichthys olivaceus,
leukocytes that were infected with Hirame rhabdovirus (HRV) in order to analyze
some of the genes that are induced and expressed by virus infection in the immune
system. Four hundred and fifty-two partial sequences representing 300 cDNA clones
were obtained from the 5' and/or 3' ends of inserts derived from the Japanese
flounder leukocyte cDNA library. About three-quarters of the 300 cDNA clones (217
clones, 72.3%) represented known genes in the public databases, whereas the
remaining 83 (27.7%) of the clones did not show any significant homology with the
sequences in the public databases. Clones matching known genes were classified
into 12 categories according to their function or distribution. Only 40 (18.4%)
of the 217 known genes showed homology with fish genes deposited in the database.
Thirty (10%) of the clones, encoding 21 different sequences, and representing
several categories, were identified as putative biodefense genes or genes
associated with the immune response. Nineteen of the 21 putative biodefense or
immune response-related cDNAs have not been previously reported in fish genes or
cDNAs.
PMID- 10689096
TI - Regulation of innate immunity in tilapia: activation of nonspecific cytotoxic
cells by cytokine-like factors.
AB - Exposure of tilapia (Oreochromis niloticus) to water temperatures of 10-15
degrees C for 3-5 min produces physiological stress responses characterized by
immediate phenotypic and immunological changes. In the present study, this
general stress response was utilized as a model system to study innate immunity
mediated by soluble factors and cytotoxic cells. Acute innate cytotoxic responses
of nonspecific cytotoxic cells (NCC) in the peripheral blood (PBL), anterior
kidney (AK) and spleen (SPL) were measured. Following temperature stress, the
levels of NCC activity depended on the presence of soluble factors and on the
cell compartments from which the NCC were obtained. NCC from PBL of stressed
tilapia had 30x or greater cytotoxic activity compared to nonstressed PBLs from
controls. NCC activity from the AK and SPL of stressed tilapia was lower than
controls. Flow cytometric analysis of NCC in each tissue showed that increased
cytotoxicity was not produced by increased numbers of NCC. To determine the
mechanism of amplification of cytotoxicity, NCC from nonstressed tilapia were
passively treated with serum from temperature stressed tilapia. Serum containing
the "stress activated serum factor" (SASF) passively increased naive NCC
cytotoxicity (from PBL) 3-4 fold. The cytotoxic cell response was inhibited by
addition of anti-NCC monoclonal antibody 5C6. These data indicated that NCC are
(at least one of) the target cells for SASF. SASF required only 15 min pre
incubation with naive NCC to activate cytotoxicity. Activation was nonreversible
and concentration dependent. Pretreatment of NCC with SASF reduced the assay time
required to amplify target cell cytotoxicity from 12-24 h to 6 h. SASF
amplification of NCC cytotoxicity was not restricted by different histological
types of target cells. Determination of select physical/chemical properties of
SASF revealed: complete heat inactivation of cytotoxicity amplification following
55 degrees C and 65 degrees C pretreatment; SASF was thermostable at room
temperature to 45 degrees C for 15 min; and freeze-thaw treatment reduced but did
not completely remove amplification activity. The molecular weight range of SASF
activity was identified in a 50-100 kDa fraction obtained by differential
dialysis. SASF appears to be a protein sensitive to trypsin digestion.
PMID- 10689097
TI - Regulation of chicken haemopoiesis by cytokines.
AB - The continuous production, control and functional activation of blood cells
involves a complex series of cellular events in which a small population of stem
cells generates large numbers of mature cells. The survival, proliferation and
development of these cells is strictly dependent on extracellular signals, among
these are polypeptide regulators generally known as cytokines. While a large
number of mammalian cytokines with proliferative and inhibitory effects have been
described in detail, it is surprising that comparatively little is known of the
avian system. Given the success of human cytokines as a model, the ability to
manipulate the chicken haemopoietic and lymphopoietic systems by precise
application of purified cytokines provides a rational approach to defence against
disease. As a general caveat, an increased awareness of the existence of
regulatory networks and the likelihood that these regulators were designed to
function most effectively when acting in combination, will provide an
understanding into the regulation of haemopoiesis and hence find application in
both clinical and agricultural research.
PMID- 10689098
TI - Ontogeny of IgA(+) cells in lamina propria: effects of sympathectomy.
AB - The effect of chemical sympathectomy on the ontogeny of the IgA(+) cells in the
intestinal LP was examined in weanling rats. Ablation of the peripheral
sympathetic nerve terminals using 6-hydroxydopamine (6-OHDA) on days 14 and 17
was associated with an increase in the number of IgA(+) and IgM(+) cells in the
intestinal LP at 28, 30 and 35 days of age. Despite the precocious development of
Ig-containing cells in the gut, the specific intestinal immune response to
ovalbumin (OVA), induced by IP priming with OVA at 30 days of age and boosting ID
14 days later, was not altered by 6-OHDA treatment, with no difference observed
in the numbers of total AOCC or IgA(+)/AOCC in the LP of treated, compared to
control animals. The results presented in this study suggest that sympathetic
innervation is an influential factor in the ontogeny of IgA(+) cells populating
the intestinal lamina propria, although no functional significance in terms of
the specific local response to a new antigen was detected using the immunisation
model described here.
PMID- 10689099
TI - Editorial
PMID- 10689100
TI - Review of thymic hormones in cancer diagnosis and treatment.
AB - The thymus is an endocrine organ. A unified, physiological concept of humoral
regulations of the immune response has emerged in the last three decades. The
thymus is the major site of production of immunocompetent T lymphocytes from
their hematopoietic stem cells. This complex process required direct cell to
cell, receptor based interactions, as well as in situ paracrine information via
the numerous cytokines and thymic hormones produced by the cells of thymic
microenvironment. Thymic hormones induce in situ T-cell marker differentiation,
expression and functions. These polypeptide hormones have also been shown by
means of immunocytochemistry to localize in the reticulo-epithelial (RE) cells of
the thymic cellular microenvironment. Due to the great complexity of the
intrathymic maturation sequence of T lymphocytes and the diverse
immunophenotypically unique subpopulations of T lymphocytes, it is quite unlikely
that a single thymic humoral factor could control all of the molecular steps and
cell populations involved. It is much more likely that an extremely rich and
diverse, but genetically determined, milieu is present within the thymus, and
that thus the control of intrathymic T lymphocyte maturation and the functional
maturation of T cells involves the orchestral interaction of various thymic
specific factors and other molecules during the differentiation process. Thymosin
fraction 5 and its constituent peptides influence several properties of
lymphocytes including cyclic nucleotide levels, migration inhibitory factor
production, T-dependent antibody production, as well as the expression of various
cell surface maturation/differentiation markers. Recently, derivatives of thymic
hormones, mostly of thymosins, have been detected as products of neoplastically
transformed cells and employed in the early diagnosis of neoplasms. In clinical
trials, thymic hormones strengthen the effects of immunomodulators in
immunodeficiencies, autoimmune diseases, and neoplastic malignancies. Combined
chemo-immunotherapeutical anti-cancer treatment seems to be more efficacious than
chemotherapy alone, and the significant hematopoietic toxicity associated with
most chemotherapeutical clinical trials can be reduced significantly by the
addition of immunotherapy.
PMID- 10689101
TI - Influence of melatonin on immunotoxicity of cadmium.
AB - The results suggested that immunotoxicity induced by Cd was significantly
restored or prevented by MLT. MLT (10 or 50 mg/kg) was orally administered to ICR
mice daily for 28 consecutive days, and cadmium (Cd, as [Cd(AC)(2)]) was also
administered at 25 mg/kg by the same route 2 h after the administration of MLT,
and the normal mice were given vehicle. Within the Cd plus MLT-treated group, the
body weight gains and relative thymus weights were significantly increased when
compared with the treatment of Cd alone. The relative spleen and liver weights
were increased by treatment of Cd alone, then restored to normal value by MLT
treatment. Hemagglutination (HA) titer, primary IgM antibody response to SRBC,
and secondary IgG antibody response to BSA was significantly increased with the
Cd plus MLT-treated mice, as opposed to when compared with treatment of Cd alone.
The NK cell and phagocytic activity used for evaluation of non-specific
immunocompetence was significantly increased in Cd plus MLT-treated mice when
compared with the treatment of Cd alone. The number of peripheral leukocytes was
significantly increased in Cd plus MLT-treated mice when compared with treatment
of Cd alone.
PMID- 10689102
TI - Effect of adrenalectomy on ethanol-associated changes in lymphocyte cell numbers
and subpopulations in thymus, spleen, and gut-associated lymphoid tissues.
AB - Consumption of ethanol (ETOH) by experimental animals and human beings is
associated with elevated serum levels of corticosteroids. One of the most robust
findings associated with ETOH consumption is a loss of lymphocytes from thymus
and spleen, as well as from peripheral lymphoid organs to include mesenteric
lymph nodes and Peyer's patches, which are lymphoid organs associated with the
gastrointestinal tract. To study the role of corticosteroids in loss of cells
from thymus, spleen, and gut-associated lymphoid organs, adrenalectomized (ADX)
or intact C57Bl/6 mice were fed a liquid diet containing ETOH (to supply 36% of
calories as ETOH) or an isocaloric control diet with a pair-feeding protocol.
Loss of lymphocytes from all lymphoid organs was associated closely with serum
corticosterone levels in both ETOH-fed and pair-fed groups. ETOH-fed ADX animals
showed much less cell loss than did ETOH-fed intact animals. However, there was
still an association between ETOH consumption and cell loss when cell loss in
ETOH-fed ADX animals was compared with that in ADX pair-fed and ADX chow-fed
groups. In both intact and ADX animals ETOH consumption was associated with a
loss of immature (CD4(+) and CD8(+)) cells from the thymus. These data lead to
the suggestion that corticosteroids are responsible for most of the cell loss
from thymus, spleen, mesenteric lymph nodes, and Peyer's patches in association
with ETOH consumption. Some cell loss, however, is independent of
corticosteroids. The data presented here also support the suggestion that cell
loss from lymphoid organs could be the result of nutritional factors.
PMID- 10689103
TI - Effects of a glyconutrient on macrophage functions.
AB - Previous studies have shown that mannosylated bovine serum albumin (mBSA)
enhances the respiratory burst (RB), phagocytosis, and killing of Candida
albicans and Escherichia coli by resident murine peritoneal macrophages (Mphi).
Upregulation of the above Mphi functions was associated with the binding of mBSA
to the macrophage mannose receptor. The present study was done to determine if
certain glyconutrients could stimulate Mphi functions in a similar manner.
Resident peritoneal murine Mphi collected from C57BL/6 mice were exposed to the
glyconutrients for 10 and 60 min. The RB was measured using chemiluminescence.
Both phagocytosis and killing were measured after incubation with each of the
following microorganisms: Candida albicans, Escherichia coli and Staphylococcus
aureus. The percent phagocytosis and killing were determined using fluorescence
microscopy. Results indicated that certain glyconutrients, caused a dose and time
dependent effect on Mphi-induced killing of all three microorganisms.
PMID- 10689104
TI - Mechanism of thymocyte apoptosis induced by serum of tumor-bearing host: the
molecular events involved and their inhibition by thymosin alpha-1.
AB - The observations presented in this paper indicate that serum of Dalton's lymphoma
(DL) bearing mice contained certain soluble factor(s) that augmented the
induction of apoptosis in thymocytes in a time- and dose-dependent manner. DL
ascitic fluid and DL-conditioned medium could also induce apoptosis of thymocytes
in vitro, though the magnitude of the same was consistently lower than that
induced by serum of DL-bearing mice. It was observed that the interaction of FasL
and TNFalpha with their respective receptors could trigger apoptosis in
thymocytes. Elucidation of the signal transduction mechanism revealed involvement
of protein tyrosine kinase, protein kinase C and ser/thr phosphatases with
concomitant increase in the level of protein products of apoptosis associated
genes p53, bax, bad, fas and fas ligand and cleavage of N-terminal 23 kDa
fragment of Bcl-2 that exhibited Bax-like death effector properties. Further, we
report, for the first time, the ability of thymosin alpha-1, an
immunopotentiating thymic hormone, to antagonize apoptosis in thymocytes induced
by factors present in serum of DL-bearing mice. The underlying mechanism of tumor
serum induced apoptosis inhibition by thymosin alpha-1 was also analyzed. The
signal transduction cascade evoked by thymosin alpha-1 involves activation of
protein kinase C with a decrease in the level of protein products of proapoptotic
genes like bax and bad and increase in the protein products of bcl-2 gene.
PMID- 10689105
TI - Effect of FTY720, a novel immunosuppressant, on adjuvant- and collagen-induced
arthritis in rats.
AB - The anti-arthritic effect of FTY720, 2-amino-2-[2-(4-octylphenyl)ethyl]propane
1,3-diol hydrochloride, a novel immunosuppressant which induces peripheral
lymphocyte homing to peripheral lymph nodes, was compared with those of anti
rheumatic compounds, mizoribine and prednisolone in rat adjuvant-induced
arthritis (AA) and collagen-induced arthritis (CIA). FTY720 at doses of 0.03-0.3
mg/kg, mizoribine at 3-30 mg/kg, and prednisolone at 1-10 mg/kg were orally
administered to rats for 21 days from the day of inoculation with heat-killed
Mycobacterium tuberculosis or type II collagen. Efficacy of FTY720 at 0.3 mg/kg
was almost equal or higher as compared with those of mizoribine and prednisolone
in both AA and CIA models. FTY720, but not mizoribine and prednisolone, decreased
selectively lymphocyte counts in the peripheral blood in both models below the
levels of the normal rats. Although FTY720 gave no other abnormal signs resulting
in side effects, mizoribine was lethal to rats at 30 mg/kg and prednisolone
inhibited body weight gain at 10 mg/kg, indicating that FTY720 has a wider margin
of safety compared with these reference compounds. FTY720 also inhibited the
production of anti-collagen antibody in CIA model, while neither mizoribine nor
prednisolone did it. These results suggest that FTY720 is a promising compound
for the treatment of arthritis with a unique profile.
PMID- 10689106
TI - Rose payne: memories from 1973-1976
PMID- 10689107
TI - Origins of the first HLA specificities.
AB - Following the discovery of the first histocompatibility antigen "MAC" in 1958,
numerous independent laboratories began identifying HLA specificities with allo
antibodies. During the span of about a decade, 1958-1970, virtually all of the
common HLA-A and HLA-B antigens were identified by various names and presented at
the International Histocompatibility Workshops by means of different serological
methods. Because many of the independently discovered specificities were found to
be reactive to similar determinants on lymphocytes, it became necessary to
classify the antigens by means of a standard method. The micro lymphocytotoxicity
test was chosen to be the basis for future antigen testing, thereby allowing the
various laboratories to confidently exchange sera. At the 1968 WHO Nomenclature
meeting, the naming of the first antigen ultimately gave rise to the designation
"HLA" in the human MHC Class I antigen system. This paper looks back upon the
origins of the early serologically identified HLA specificities and their
respective founders.
PMID- 10689108
TI - Immunological tolerance in an HLA non-identical chimeric twin.
AB - Blood group chimeric twins offer a unique opportunity to study immunological
tolerance in humans. Although this condition is not as rare as previously
considered, detailed immunological studies of blood group chimeras are lacking.
We describe here a case of secondary chimerism in a dizygotic twin of opposite
gender. The karyotypes of the cultured fibroblast confirmed the sex of each twin,
all cells in the boy were 46, XY and all cells in the girl were 46, XX. Molecular
HLA typing on fibroblasts revealed HLA-DR, DQ and DP disparities between the two
siblings. Mixed lymphocyte culture (MLC) revealed a mutual absence of
alloreactivity.
PMID- 10689109
TI - Human CD1a molecule expressed on monocytes plays an accessory role in the
superantigen-induced activation of T lymphocytes.
AB - The CD1 molecules exhibit characteristics of the MHC class I and class II
molecules. They are expressed on cortical thymocytes and, similarly to MHC class
II molecules, on antigen-presenting cells. In the present study, we investigated
the role of the CD1 molecules in the T-cell response to bacterial superantigens.
Indeed, we have observed that CD1 molecules could be detected on the CD14
positive population of some healthy donors (14% of donors tested). The CD1
expression on monocytes is correlated with an activation state of the donors as
demonstrated by the increased expression of the CD25, CD38, CD45R0, and MHC class
II molecules on their lymphocytes. On these donors, CD1a mAbs induced a clear
inhibition (65%) of lymphocyte proliferation induced by either staphylococcal
enterotoxin A or toxic shock syndrome toxin-1, whereas this proliferation was
constantly unaffected by the addition of mAbs directed against CD1b or CD1c.
Moreover, an intracellular calcium flux was induced in monocytes following CD1a
engagement, and this calcium flux was partially inhibited by preincubation of
these cells with the superantigen. These results attribute to the CD1a molecule
expressed by monocytes a role in the transduction of signal(s) involved in
superantigen-induced activation.
PMID- 10689110
TI - Mitogen-induced modulation of CD3, CD4, and CD8(1).
AB - It is not clear whether CD3 contacts CD4 or CD8 directly, nor have the regulation
and interregulation of expression of these three receptor molecules been
determined. We explored these issues by first stimulating human peripheral blood
lymphocytes in vitro with three well-characterized T-cell receptor-directed
mitogens (phytohemagglutinin [PHA], concanavalin A [ConA], and anti-CD3
monoclonal antibody [alphaCD3]) and then using multiparameter flow cytometric
techniques to investigate modulation of surface (sur) and cytoplasmic (c) CD3,
CD4, and CD8. Cultures with alphaCD3 had a rapid, large, and persistent decline
in surCD3; the cCD3 median fluorescent intensity (MFI) declined gradually, over
the entire culture period. With alphaCD3, surCD4 MFI and cCD4 MFI declined by
days 4 to 8 (31% of ex vivo value, p < 0.001 and 47%, p = 0.033), as did surCD8
MFI (58%, p = 0.010). PHA was associated with an increase in surCD8%, surCD8 MFI,
and cCD8% at days 4 to 8 (178% of ex vivo, p = 0.003; 168%, p = 0.025; and 331%,
p = 0.001). For PHA at days 4 to 8, cCD8 MFI was highly variable but always
higher than in unstimulated cultures (5 of 5 experiments). With ConA, at 3 to 5
hours ex vivo, there was a decrease in surCD3 MFI relative to ex vivo (64%),
surCD4% (83%), cCD4% (87%), surCD4 MFI (50%) and cCD4 MFI (48%), surCD8% (85%)
and an increase in cCD8% (260%). As with PHA, at days 4 to 8, surCD8% was high
relative to ex vivo (169%). Thus, we found that alphaCD3 had delayed effects on
CD4 and CD8; PHA had delayed effects on CD8 only; and ConA had very rapid effects
on CD3, CD4, and CD8, as well as a delayed effect on surface CD8. These effects
involve both surface and cytoplasmic antigen expression and are more consistent
with degradation or retention, rather than with shedding or increased production.
They may reflect direct interactions between CD4 or CD8 and CD3 and/or
interregulation of CD3 expression with expression of these coreceptor molecules.
PMID- 10689111
TI - The full length HLA-G1 and no other alternative form of HLA-G is expressed at the
cell surface of transfected cells.
AB - In contrast to HLA class Ia, the HLA-G class Ib transcripts can be alternativeley
spliced to yield several isoforms including four potentially membrane-bound
variants, namely HLA-G1, -G2, -G3 and G4. It is so far unclear whether each of
these splice variants lacking one or two external domains is properly translated
and expressed at the cell surface. We used targeted Enhanced Green Fluorescence
Protein (EGFP)-HLA-G fusion cDNA to track HLA-G isoform expression in living
murine (L-human beta2m) and human (JAR) transiently transfected cells. It was
demonstrated that the four HLA-G1, -G2, -G3, and -G4 isoforms were translated in
these transfectants by the means of (i) Western blotting analysis, using an anti
EGFP mAb; (ii) intracellular double labeling flow cytometry analysis, using the
EGFP natural fluorescence and phycoerythrin-labeled HCA2 anti-HLA-G mAb; and
(iii) immunocytochemistry on isolated acetone fixed transfectants with the use of
different anti-HLA-G mAbs. Cell surface flow cytometry analysis using the HCA2
mAb revealed that only the HLA-G1 isoform was expressed as a membrane-bound
protein. Two color confocal microscopy performed on fixed, permeabilized cells
further showed that the EGFP green fluorescence co-localized with anti-calnexin
rhodamine fluorescence in the four HLA-G isoform transfectants but only in HLA-G1
transfectant was the green EGFP fluorescence also detectable at the outer part of
the cells, suggesting that the HLA-G2, -G3, and G4 were retained in the
endoplasmic reticulum. Such intracellular retention of the three shorter forms of
HLA-G suggest that they may play a role in regulating cell surface expression
either of the full length HLA-G1 form or of HLA-E.
PMID- 10689112
TI - Lewis(x)-containing oligosaccharide attenuates schistosome egg antigen-induced
immune depression in human schistosomiasis.
AB - The proliferative and interleukin (IL)-10 responses to Lacto-n-fucopentaose III
(LNFPIII) that contains Lewis(x)(Le(x))-trisaccharide was assessed in PBMC from
humans infected with Schistosoma mansoni. All patient groups with low, medium,
and high egg counts in their feces responded to polyvalent LNFPIII-HSA (where HSA
= human serum albumin) conjugate. PBMC of all subjects showed a significant
proliferative response to this sugar conjugate. However, the levels of
interleukin (IL)-10 induced by LNFPIII-HSA were higher in groups with low and
medium egg counts than those with high egg. Soluble egg antigens (SEA) also
induced IL-10 production by PBMC from infected patients. Interestingly, the SEA
induced IL-10 production was remarkably inhibited by pretreatment of PBMC with
free ligands of LNFPIII (monovalent form). These LNFPIII-pretreated PBMC
displayed appreciable increase in the level of proliferation to SEA stimulation.
We propose that the observed bystander immune potentiation rendered by free
LNFPIII is due to the reduced IL-10 level which, presumably, up-regulate
expression of co-stimulatory molecules on APC. The ensemble of results indicates
that the Le(x)-containing LNFPIII is a potent immunoreactive epitope in SEA that
negatively influences PBMC response against this parasite antigens via IL-10.
PMID- 10689113
TI - Increased serum-soluble interleukin-2 receptor in burn patients: characterization
and effects on the immune system.
AB - The consequences of high serum concentrations of the interleukin (IL)-2 receptor
alpha chain (sIL-2Ralpha) in several diseases are poorly understood. The
objective of this study was to determine the form of sIL-2Ralpha in burn patients
and its biological role. sIL-2Ralpha was measured in 18 severely burned
individuals who received nutritional support with a normal or low fat content.
sIL-2Ralpha was elevated throughout the study and it was notably lower in
patients fed a low fat diet. Serum IL-6 and sIL-2Ralpha significantly correlated
(r = 0.74, p < 0.05) in burn patients. The presence of sIL-2Ralpha was associated
with a decrease in DR molecules in the CD2(-) and CD11b(+) cells of these
patients. Western blot analysis of serum protein with N-terminal or C-terminal
specific antibodies indicated that sIL-2Ralpha represents the extracellular
domain of this molecule. Patient serum inhibited specifically murine, but not
human IL-2-dependent T-cell proliferation. To determine the significance of sIL
2Ralpha, recombinant sIL-2Ralpha was used in different cellular model involving
IL-2. sIL-2Ralpha inhibited natural killer cell activity by 50% in the presence
of IL-2. The basal proliferation of peripheral blood mononuclear cells was
inhibited by sIL-2Ralpha, but phytohemagglutinin-induced proliferation was
unaffected by this form of receptor. Interferon (INF)-gamma production induced by
OKT-3 on peripheral blood mononuclear cells was not altered by sIL-2Ralpha, but
IL-2 induced increase in INF-gamma production was suppressed. The decreasing
production of INF-gamma in the presence of IL-4 was significantly increased in
the presence of sIL-2Ralpha in media. These results show that the large amount of
sIL2-Ralpha circulating in burn patients is related to the inflammatory response.
The amount of dietary fat modulates sIL2Ralpha concentration in burn patients,
confirming the beneficial effect of low fat administration after burn trauma.
Inhibition of T-cell activation in burn patients is not directly related to sIL
2Ralpha, although the presence of sIL-2Ralpha in serum can inhibit some IL-2
mediated response, such as the emergence of TH1 and TH2 cells.
PMID- 10689114
TI - Intestinal alphabeta T cells of symptomatic celiac disease patients show
oligoclonal TCRBV repertoire but polyclonal rearrangement patterns.
AB - Celiac disease is an immunological disease provoked by some cereal proteins in
HLA-DQ-mediated susceptible individuals. The role of intestine infiltrating
alphabeta T cells in the pathogenesis of the disease has been functionally
established. In the present report, we have studied the repertoire of TCRBV
genes, spectratype distribution, and CDR3 sequences of intestinal T cell
populations isolated from three CD patients at diagnosis and two normal control
biopsies. Oligoclonal TCRBV usage was observed both in CD and control samples.
However, a much more restricted TCRBV usage was evident in normal mucosa. The use
of BV gene families was linked to no dominant rearrangements in CD, while
apparent oligoclonal patterns were found in normal biopsies. Only 3 out of 73
sequenced transcripts derived from preponderant TCRBV genes in the three celiac
samples were obtained twice. In contrast, only 13 different rearrangements were
found out of 32 analyzed in control samples. In spite of the polyclonal behavior
of T cells in CD mucosa, some conserved motifs in the CDR3 region were noticed
among rearrangements derived from different TCRBV genes and patients. The lack of
expanded T cell clones in the damaged tissue could be explained in terms of
antigen diversity or by non-specific immunological responses in the symptomatic
phase of the disease.
PMID- 10689115
TI - Antigen mimicry in autoimmune disease. Can immune responses to microbial antigens
that mimic acetylcholine receptor act as initial triggers of Myasthenia gravis?
AB - Myasthenia gravis (MG) is an autoimmune disease caused by autoantibodies against
self acetylcholine receptor (AChR). Although a great deal of information is known
about the molecular and cellular parameters of the disease, its initial trigger
is not known. In order to study the possibility of the involvement of microbial
antigens that mimic AChR in triggering MG, we have searched the microbial
proteins in the data bank for regions that are similar in structure to the
regions of human (h) AChR alpha chain recognized by autoAbs in MG patients.
Hundreds of candidate structures on a large number of bacterial and viral
proteins were identified. To test the feasibility of the idea, we synthesized
four microbial regions similar to each of the major autodeterminants of hAChR
(alpha12-27, alpha111-126, alpha122-138, alpha182-200) and investigated their
ability to bind autoAbs in MG and normal sera controls. It was found that MG sera
recognized a significant number of these microbial regions. The results indicate
that in some MG cases immune responses to microbial antigens may cross-react with
self antigen (in this case hAChR) and could constitute initial triggers of the
disease.
PMID- 10689116
TI - Specific and general HLA-DR binding motifs: comparison of algorithms.
AB - Using panels of peptides well characterized for their ability to bind to HLA DR1,
DRB1*1101, or DRB1*0401 molecules, algorithms were deduced to predict binding to
these molecules. These algorithms consist of blocks of 8 amino acids containing
an amino acid anchor (Tyr, Phe, Trp, Leu, Ile, or Val) at position i and
different amino acid combinations at positions i+2 to i+7 depending on the class
II molecule. The sensitivity (% of correctly predicted binder peptides) and
specificity (% of correctly predicted non-binder peptides) of these algorithms,
were tested against different independent panels of peptides and compared to
other algorithms reported in the literature. Similarly, using a panel of 232
peptides able to bind to one or more HLA molecules as well as 43 non-binder
peptides, we deduced a general motif for the prediction of binding to HLA-DR
molecules. The sensitivity and specificity of this general motif was dependent on
the threshold score used for the predictions. For a score of 0.1, the sensitivity
and specificity were 84.7% and 69.8%, respectively. This motif was validated
against several panels of binder and non-binder peptides reported in the
literature, as well as against 35, 15-mer peptides from hepatitis C virus core
protein, that were synthesized and tested in a binding assay against a panel of
19 HLA-DR molecules. The sensitivities and specificities against these panels of
peptides were similar to those attained against the panels used to deduce the
algorithm. These results show that comparison of binder and non-binder peptides,
as well as correcting for the relative abundance of amino acids in proteins, is a
useful approach to deduce performing algorithms to predict binding to HLA
molecules.
PMID- 10689117
TI - Complementation between specific HLA-DR and HLA-DQ genes in transgenic mice
determines susceptibility to experimental autoimmune encephalomyelitis.
AB - To investigate the contribution of human leukocyte antigen (HLA) class II
molecules in susceptibility to inflammatory demyelination, we induced
experimental autoimmune encephalomyelitis (EAE) in transgenic (tg) mice
expressing the HLA-DR3, HLA-DQ8 and HLA-DQ6 molecules in the absence of
endogenous class II (Ab(o)). Following immunization with mouse myelin, HLA-DR3 tg
mice mounted strong T-cell proliferative responses, and developed inflammatory
lesions and demyelination in the central nervous system with mild to moderate
clinical symptoms of EAE. HLA-DQ8 and HLA-DQ6 tg mice elicited weak T-cell
proliferative responses and did not develop clinical symptoms of EAE. HLA-DR3/DQ6
double tg mice immunized with mouse myelin experienced clinical disease similar
to the single tg HLA-DR3 tg mice, indicating that expression of DQ6 in this line
had no effect on disease. In contrast, HLA-DR3/DQ8 double tg mice developed
severe inflammatory lesions and clinical disease in response to immunization with
mouse myelin. Our data suggest that in the presence of two susceptible class II
alleles, namely HLA-DR3 and DQ8, there is additional selection and expansion of
potential autoreactive T cells, resulting in enhanced severity of disease.
PMID- 10689118
TI - The HLA-E locus is associated with age at onset and susceptibility to type 1
diabetes mellitus.
AB - Previous studies have suggested that the human leukocyte antigen (HLA) class I
region may be involved in determining the age at onset and clinical severity of
type 1 diabetes. We have investigated the frequency of polymorphisms of the
nonclassical HLA class I gene, HLA-E, in 199 British Caucasian patients with type
1 diabetes and 82 healthy controls. A highly significant increase in the
frequency of the HLA-E 0101 genotype was found in the patients compared to
controls (chi(2) = 15.3, p < 0.00009). The frequency of the HLA-E 0101 genotype
was increased in those patients diagnosed after 10 years of age, while the
frequency of the 0101, 0103 genotype was significantly increased in those
subjects diagnosed before 10 years of age (chi(2) = 26.0 p < 0.000003 and chi(2)
= 13.0 p < 0.0003, respectively). No obvious interaction between the HLA-E locus
and the class II DQB1*0201, 0302, and 0501 susceptibility alleles was found. This
is the first report of an association between the HLA-E locus and susceptibility
to an autoimmune disease.
PMID- 10689119
TI - HLA-DR and -DQ associations with insulin-dependent diabetes mellitus in a
population of Turkey.
AB - Genetic susceptibility to insulin-dependent diabetes mellitus (IDDM) has been
shown to be associated with MHC in many studies. To extend this data with a
population with relatively low IDDM incidence, MHC DRB, DQA, and DQB have been
investigated by polymerase chain reaction and sequence specific oligonucleotide
probe hybridization (PCR/SSO) in 178 IDDM patients from Turkey and compared to
248 healthy controls. Significant differences are detected between IDDM and
control groups in the frequencies of DRB1*0402 DQA1*03 DQB1*0302 (28.1% vs. 5.2%,
p < 0.0001, OR: 7.1) and DRB1*0301 DQA1*0501 DQB1*02 (57% vs. 18.1%, p < 0.0001,
OR: 6.1). Among the negative associations, the most strong ones are with
DRB1*1401 DQA1*0101 DQB1*0503 (0.6% vs. 8.9%, p < 0.0001, OR: 0.1), DRB1*1502
DQA1*0103 DQB1*0601 (1.1% vs. 7.7%, p = 0.0023, OR: 0.1), DRB1*1301 DQA1*0103
DQB1*0603 (0.6% vs. 6.9%, p = 0.0039, OR: 0.2) and DRB1*1101 DQA1*0501 DQB1*0301
(3.9% vs. 12.1%, p < 0.0001, OR: 0.2). When the DRB, DQA or DQB genotypes of the
susceptible alleles are compared, the most strong susceptibility marker of the
disease is found to be DRB1*0301/*04 (31.4% vs. 2.8%, p < 0.0001, OR: 15.8) and
among these, heterozygote genotype DRB1*0301/*0401 (4.5% vs. 0, p = 0.0008, OR:
24.8). These results confirm the positive associations with IDDM previously
observed in other Caucasian populations and reveal many negative and strong
associations which maybe underlining several characteristics that distinguish
Turkish diabetics form other Caucasians.
PMID- 10689120
TI - The association of HLA-DM genes with rheumatoid arthritis in Eastern France.
AB - In this study, the polymorphisms of the HLA DMA and DMB genes in patients with
rheumatoid arthritis (RA) were examined.DMA and DMB typing was performed in 120
white RA patients from eastern France and 100 healthy controls, using PCR-SSO
(sequence specific oligonucleotide probes) method for DMA determination and PCR
RFLP (restriction fragment length polymorphism) method for DMB typing. All
patients and controls had been HLA DRB1* genotyped.DMA*0103 was found
significantly increased in RA patients (RA vs. controls: 18.3% vs. 4%) (p(corr) =
0.004; OR: 5.39; CI: 1.67-19.23). A decreased frequency of DMA*0102 was also
observed in the RA group (RA vs. controls: 18.3% vs. 31%), but not significantly.
There were no differences in the prevalence of DMB alleles between RA and
controls. The patients and the controls were then stratified according to the
expression of the HLA DRB1* RA-linked alleles (DRB1*01 and *04) and this allowed
us to find no linkage disequilibrium between DMA*0103 and DRB1*01 or *04 alleles.
Finally, most DMA*0103 patients were positive for rheumatoid factors and had
extraarticular involvement such as subcutaneous nodules. Thus, our results
suggest that DMA*0103 could be an additional genetic factor for RA susceptibility
in French whites.
PMID- 10689122
TI - Association of hypersensitivity to the nematode Anisakis simplex with HLA class
II DRB1*1502-DQB1*0601 haplotype.
AB - Anisakiasis as well as allergic and anaphylactoid reactions to Anisakis simplex
antigens are recently identified clinical entities. They are relatively frequent
in countries with habitual raw food consumption, often in the form of large
amounts of fish and sea food products. In this communication the relationship
between HLA class II alleles and the IgE-specific immune response to A. simplex
allergen was studied in a defined population in Northern Spain. Individuals with
immediate-type Anisakis hypersensitivity and healthy controls were examined for
HLA-DRB1, DQB1 and DQA1 alleles by sequence-specific oligonucleotide probe
typing. Analysis of the HLA data among patients revealed increased phenotypic
frequencies for DRB1*1502 and DRB1*0404 compared to healthy controls (p < 1 x 10(
7) and < 0.01, respectively). Analysis of haplotypic frequencies showed that the
DRB1*1502-DQB1*0601 haplotype is significantly higher in patients with Anisakis
hypersensitivity in comparison with the control population from the same region
(p < 4 x 10(-8)). The data suggest that this haplotype can be considered to be a
susceptibility factor for hypersensitivity to A. simplex antigens.
PMID- 10689121
TI - Analysis of TAP and HLA-DM polymorphism in thai rheumatoid arthritis.
AB - Rheumatoid arthritis is an autoimmune disease with a strong association with DR4
in many populations. In the Thai population, rheumatoid arthritis is associated
with DRB1*0405. To evaluate the role of polymorphism in TAP and HLA-DM genes,
which are important in antigen processing and presentation in predisposition to
rheumatoid arthritis, 82 Thai patients with rheumatoid arthritis and 100
unrelated normal controls were studied. TAP and HLA-DM typing was performed by
ARMS-PCR and PCR-SSO method, respectively. There was no difference in the
distribution of TAP1, TAP2, DMA, and DMB genes between the patients and controls.
This study suggested that TAP and HLA-DM genes do not confer susceptibility to
rheumatoid arthritis.
PMID- 10689123
TI - HLA class II DRB1, DQB1, DPB1 polymorphism and cardiomyopathy due to Trypanosoma
cruzi chronic infection.
AB - Trypanosomiasis is an important cause of cardiomyopathy in endemic rural areas of
Latin America. Previous studies have suggested participation of HLA molecules in
the immune response regulation of T. cruzi infection, and association of HLA
antigens with heart damage. One hundred and eleven unrelated T. cruzi antigen
seropositive individuals were tested for HLA class II alleles by the polymerase
chain reaction and sequence specific oligonucleotide (PCR-SSO) method. Patients
were classified in 3 groups according to clinical and electrocardiographic
characteristics: asymptomatics (group A), with arrhythmia (group B), and with
overt congestive heart failure (group C). Statistical analysis confirmed the
significant increment of the DRB1*01 DQB1*0501 haplotype (p = 0.03) previously
reported by our laboratory in patients with cardiomyopathy. The DPB1*0401 allele
frequency is also significantly increased in patients with heart disease (groups
B + C) (p = 0.009) while DPB1*0101 frequency is higher among the asymptomatic
group (p = 0.04) compared with individuals of group C. The DPB1*0401 allele in
homozygous form or in combination with allele DPB1*2301 or 3901, was found
present more often in patients of groups B and C. Thus, the combination of two of
these three alleles, sharing specific sequence motifs in positions 8, 9, 76, and
84-87 confers a relative risk of 6.55 to develop cardiomyopathy in seropositive
patients (p = 0.041). Furthermore, 32% of the cardiomyopathics have either
DRB1*01 DQB1*0501 and/or DPB1*0401/*0401, 0401/*2301, or* 0401/*3901 compared
with 9% of the seropositive asymptomatics (OR = 5.0; p = 0.006).
PMID- 10689125
TI - Frequencies of HLA-A2 alleles in five U.S. population groups. Predominance Of
A*02011 and identification of HLA-A*0231.
AB - Direct DNA sequencing was used to determine the frequency of alleles within the
HLA-A2 family in five US population groups. The most frequently detected HLA-A2
allele in all groups was HLA-A*02011. Caucasian and Native American populations
appear to be the most homogeneous exhibiting 95.7% and 94.3% A*02011,
respectively. Hispanic and Asian/Pacific Islander populations were the most
allelicly diverse populations with 9 and 7 different HLA-A2 alleles present,
respectively, but the majority of the populations were HLA-A*02011. African
Americans were also diverse, not in the number of alleles seen, but in the
percentage of non-A*02011 alleles in the population. HLA-A*0202 (25.8%) and
A*0205 (12.9%) were present in a large percentage of African-Americans. Only 13
of the 31 known HLA-A2 alleles were observed in the study. The allelic
distributions reflected statistically significant differences among population
groups.
PMID- 10689124
TI - HLA class II haplotype associations with inflammatory bowel disease in Jewish
(Ashkenazi) and non-Jewish caucasian populations.
AB - Ulcerative colitis (UC) and Crohn's disease (CD) are the clinical entities
comprising idiopathic inflammatory bowel disease (IBD). Previous studies on the
association of IBD and human leukocyte antigen (HLA) class II genes suggested a
role for HLA in this disease. Here we present HLA class II (DRB1, DQB1, DQA1,
DPB1) allele and haplotype distributions determined using the polymerase chain
reaction and sequence-specific oligonucleotide probe methods. A total of 578 UC
and CD Caucasian patients and controls from Jewish (Ashkenazi) and non-Jewish
populations was examined. Our previously reported association of DR1-DQ5 with CD
was attributable to DRB1*0103. A dramatic association with IBD and the highly
unusual DRB1*0103-DQA1*0501-DQB1*0301 haplotype (OR = 6.6, p = 0.036) was found.
The more common DR1 haplotype, DRB1*0103-DQA1*0101-DQB1*0501, was also associated
with IBD (OR = 3.1, p = 0.014), a result suggesting that interaction between DR
and DQ may determine the extent of disease risk. Our previously reported
association of DR2 with UC was attributable to DRB1*1502 (OR = 2.6, p = 0.006).
At the DPB1 locus, a significant association of DPB1*0401 with CD was observed
for the combined populations (OR = 1.85, p = 0.007). These observations indicate
that some class II alleles and haplotypes confer susceptibility to both UC and
CD, implying common immunogenetic mechanisms of pathogenesis, while others confer
risk to only one of these diseases, and illustrate the value of DNA HLA typing in
disease susceptibility analyses.
PMID- 10689126
TI - HLA-DR4 allele frequencies on Indian and Mestizo population from Mexico.
AB - Using PCR-SSOP and sequencing, we examined DRB1*04 nucleotide polymorphism in 137
DR4-positive Mexican healthy individuals (46 Mexican Mestizos, 64 Mazatecans, and
27 Nahuas), carrying a total of 147 DR4 haplotypes. Eleven different DRB1*04
alleles were detected in Mexican Mestizo population, whereas, in the two Indian
groups a restricted polymorphism was observed (5 variants in Mazatecans and 4 in
Nahuas). DRB1*0407 was the most frequent allele (gf = 0.106 in Mexican Mestizos,
gf = 0.281 in Mazatecans, and gf = 0.189 in Nahuas). In spite of the restriction
in polymorphism, there were differences on DRB1*04 alleles found in Mexicans
mainly between Mazatecan and Nahua populations. DRB1*0403 was characteristic
allele in Nahua ethnic group, whereas, 0404 and 0411 were predominant alleles in
Mazatecans. This data corroborates the restricted polymorphism of DRB1*04 alleles
in American populations. In spite of the restriction in this polymorphism,
differences in frequencies of DRB1*04 alleles could help distinguish each
population.
PMID- 10689127
TI - HLA-DMA allele polymorphism: no impact on kidney allograft outcome.
AB - The purpose of this study was to analyze the association of HLA-DMA alleles with
rejection episodes and early graft loss (EGL) in renal transplant recipients. One
hundred and eighty four HLA-DMA alleles were retrospectively analyzed by DNA
sequence analysis in 92 kidney transplant recipients. The gene frequencies of HLA
DMA *0101, *0102, *0103 and *0104 were found to be similar in all recipients,
regardless of rejection vs non rejection episodes and EGL incidence. In
conclusion, HLA-DMA allele polymorphism did not impact renal allograft outcome.
PMID- 10689128
TI - HLA association with hepatitis C virus infection.
AB - Hepatitis is one of the most important infectious diseases in Thailand. The
knowledge of host factors that influence the course of the disease is still
limited. In this study, the HLA class I and class II phenotypes were analyzed in
the 2 groups of HCV-infected Thai populations. The first group included 43
individuals with transient HCV infection (HCV antibody positive, HCV RNA PCR
negative), and the second included 57 individuals with persistent chronic HCV
infection (HCV antibody positive, PCR positive). HLA class I typing was performed
by 2-stage microlymphocytotoxicity test, and HLA class II typing, by PCR-SSO. No
significant difference in the frequencies of HLA-A and -B antigens was observed
between the 2 groups of HCV-infected individuals. The frequency of DRB1*0301 and
DQB1*0201 was significantly higher in the persistent-infection group than in the
transient-infection group (Pc = 0.03, Pc = 0.04, respectively). In addition,
DRB1*0701 and DQA1*0201 were significantly decreased in all the HCV-infected
patients compared with levels in the normal controls (Pc = 0.003, Pc = 0.001,
respectively). This study demonstrated that DRB1*0301 and DQB1*0201 are
associated with persistent HCV infection, whereas DRB1*0701 and DQA*0201 are
associated with protection against HCV infection.
PMID- 10689129
TI - Nomenclature for factors of the HLA system, update October/November 1999. WHO
Nomenclature Committee for factors of the HLA system.
PMID- 10689130
TI - Immunity in the elderly
PMID- 10689131
TI - Diseases of aging.
AB - By definition, diseases of aging become clinically manifested in elderly
patients. However, their pathogenetic basis has to be sought earlier in life. The
general thread of this presentation relies on the concept of an evolutionary
Darwinian view of the development of age-related diseases. In essence, this
concept states that we may have to "pay" for genetic traits that play a
beneficial role earlier in life by the later development of diseases since there
is no post-reproductive selective pressure that may have eliminated the potential
late onset detrimental effects of such genes. Examples for this kind of trade-off
are taken from diseases involving the immune system (infections), the endocrine
system (andropause), the nervous system (Alzheimer's disease), the locomoter
system (osteoporosis), the cardio-vascular system (atherosclerosis) and cancer.
PMID- 10689132
TI - Compression of morbidity in the elderly.
AB - The Compression of morbidity paradigm envisions reduction in cumulative lifetime
morbidity through primary prevention by postponing the age of onset of morbidity
to a greater amount than life expectancy is increased, largely by reducing the
lifestyle health risks which cause morbidity and disability. Recent data document
slowly improving age-specific health status for seniors, indicate that
postponement of the onset of disability by at least 10 years is feasible, and
prove effectiveness of some lifestyle interventions by randomized controlled
trials. Human aging is increasingly represented by frailty, with declining
reserve function of many organ systems, including the immune system. Enhancement
of immune function in this setting raises medical, ethical, and social issues
which are sometimes in conflict.
PMID- 10689133
TI - Genetic factors in immunity and aging.
AB - Maximum life span is controlled by genes that regulate molecular mechanisms
accounting for the synchrony of structural and functional changes in different
cells and tissues of each member of a given species. The role of immune response
genes was investigated in aging mice genetically selected for high (H) or low (L)
antibody response (Biozzi mice). Results from genetic selection of over 1000 mice
showed that genes expressed in the immune system affect life span and diseases.
In most cases, the life span is longer in H than in L mice whereas the lymphoma
incidence is remarkably higher in L than in H mice. Since DNA repair capacity is
a property positively correlated with the maximum life span in several mammalian
species, DNA repair was studied by use of hydroxyurea, a cell-synchronizing
agent, and found to take place in irradiated human PBMC from young and, to a
lesser extent, from adult subjects. Conversely, no repair was detected in
irradiated PBMC from elderly subjects. DNA damage recognition and repair pathways
involve several nuclear proteins, as double strand breaks are firstly recognized
by proteins displaying helicase activity, such as ku 70/80, and then repair is
carried out under the control of other proteins. Radiation-induced expression of
activated ku(70/80) proteins, in terms of DNA-binding, was found in PBMC from
young-adults but not from elderly subjects. Maintenance of DNA integrity is
fundamental for normal immune functions, as suggested by the lack of V(D)J
recombination in lymphocytes of knock-out mice deficient in ku 70 or ku 80
protein. However, whether the link between genetic factors and life span is
mediated by the performance of the immune system remains to be demonstrated.
PMID- 10689134
TI - Molecular and biochemical pathways of apoptosis in lymphocytes from aged humans.
AB - In this study, we investigated a role of apoptosis in lymphopenia and progressive
cell-mediated immunodeficiency associated with aging. We examined two major
signaling pathways of apoptosis in lymphocytes from aged humans and compared them
with lymphocytes from young subjects. Both CD4+ and CD8+ T cell subsets from aged
subjects demonstrated increased sensitivity to TNFR-mediated and Fas-mediated
apoptosis that was associated with overexpression of death receptors and adapter
molecules associated with death signaling. An increased expression and activity
of both initiator (caspase 8) and effector (caspase 3) caspases was observed in
lymphocytes from aged subjects as compared to young individuals. Furthermore, an
increased expression of Bax and decreased expression of Bcl-2 (both at the
protein and mRNA level) was found in lymphocytes from aged subjects. These data
suggest that increased sensitivity of lymphocytes from aged subjects to death
signals may play an important role in the pathogenesis of lymphopenia and T cell
deficiency associated with the aging process.
PMID- 10689135
TI - Antigen receptors and dendritic cells.
AB - Several age-related alterations occurring in the immune system, especially in T
cells and in B cells, may account for an increased susceptibility to infections,
autoimmune diseases, and malignancies. In particular, the adaptive immune
response has been shown to lose part of its diversity and its memory in old mice.
However, whether dendritic cells, which play a central role in the initiation of
the cellular immunity but are also involved in humoral immunity, participate
qualitatively or quantitatively in immunosenescence remains to be determined.
PMID- 10689136
TI - Unimpaired dendritic cells can be derived from monocytes in old age and can
mobilize residual function in senescent T cells.
AB - Dendritic cells (DC) are powerful antigen presenting cells, which have the unique
capacity to stimulate naive T cells. In spite of the well-known decline of T cell
function in old age, little information is available on whether DC are also
affected by the aging process. This is mainly due to problems with the isolation
and purification of DC. Rapid progress in the characterization of DC has been
made in recent years, as simple methods to generate large numbers of DC from
precursors have been developed. It was the aim of the present study to compare
monocyte derived DC from old and young healthy persons. The generation of DC from
blood monocytes in response to GM-CSF and IL-4 treatment was similar in cells
from young and old persons. The DC population thus obtained had a typical
dendritic morphology and expressed DC surface markers, such as HLA class II,
CD1a, CD11c, CD54, CD80 and CD86, but not CD14 for a period of up to three weeks
in culture. DC from young and old persons produced IL-12 and TNF-alpha and
responded equally well to maturation-inducing stimuli. DC maturation was
stimulated by purified protein derivative (PPD) of Mycobacterium tuberculosis,
whole inactivated influenza virus and by influenza split vaccine, but not by
purified viral RNA. When tested for their antigen-presenting capacity, DC from
young and old persons were capable of stimulating the proliferation and the
cytokine production of T cells. It was of particular interest that CD45RA(+) as
well as CD45RO(+) T cells from aged donors were unable to respond to stimulation
with influenza proteins presented by monocytes, but were triggered to proliferate
and to produce cytokines when antigen was presented by DC. The results
demonstrate that DC from old persons (a) may still function as powerful antigen
presenting cells provided the right differentiation and maturation stimuli are
present; (b) are capable of mobilizing residual capacity in senescent T cells and
(c) may therefore represent a potent tool for immunotherapy and vaccines in old
age.
PMID- 10689137
TI - NK and NK/T cells in human senescence.
AB - Natural killer (NK) cells are cytotoxic cells that play a critical role in the
innate immune response against infections and tumors. Recent studies on NK cell
biology have demonstrated that besides their cytotoxic function, NK cells express
cytokine and chemokine receptors and also that they secrete other
immunoregulatory cytokines and chemokines, supporting their relevance in the
regulation of the immune response by promoting downstream adaptive, Th1 mediated,
responses against infections. Immunosenescence is the deterioration of the immune
response associated with aging. It is characterized mainly by a defective T cell
response, but includes changes in the number and function of other cells of the
innate immune system. Age-associated alterations in the number and function of NK
cells have been reported. There is a general consensus that a progressive
increase in the percentage of NK cells with a mature phenotype occurs in elderly
donors associated with an impairment of their cytotoxic capacity when considered
on a "per cell" basis. The response of NK cells from elderly individuals to IL-2
or other cytokines is also decreased in terms of proliferation, expression of
CD69 and killing of NK-resistant cell lines. Furthermore early IFN-gamma and
chemokine production in response to IL-2 or IL-12 is also decreased. However
aging does not significantly alter other NK cell functions such as TNF-alpha
production or perforin induction in response to IL-2. The percentage of T cells
that co-express NK cell markers is also increased in aging. These results
indicate that the increase in the number of "classical" mature NK and NK/T cells
in aging is associated with a defective functional capacity of NK cells. Low NK
cell number or function in elderly individuals is associated with increased
mortality risk and increased incidence of severe infections, supporting the role
of NK cells in the defense against infections in the elderly.
PMID- 10689138
TI - The splanchnopleura/AGM region is the prime site for the generation of
multipotent hemopoietic precursors, in the mouse embryo.
AB - The first hemopoietic cells were found in the yolk sac of mammalian embryos.
Based on this observation it was postulated that hemopoietic stem cells are
generated in this location. In the last few years, however, increasing evidence
indicates that there is an independent site of hemopoietic cell generation, in
the embryo proper, designated the paraaortic splanchnopleura/aorta, gonad,
mesonephros region. Precursors of hemopoietic cells are found in this region
before circulation is established between the yolk sac and the embryo proper. In
contrast to the hemopoietic cells found in the yolk sac, the ones found in the
embryo proper are multipotent lympho-myeloid precursors that rapidly acquire the
capacity to reconstitute the hemopoietic system of adult irradiated recipients.
We propose that these are the founder cells of adult definitive hematopoiesis.
PMID- 10689139
TI - Changes in the B-cell repertoire with age.
AB - Changes in the B-cell repertoire during aging include a shift in antibody
specificities from foreign to autologous antigens associated with a decline in
the activity of conventional B2 compared to B1 lymphocytes. The age-associated
increase in B1 lymphocyte number and activity contribute to the increased serum
concentration of autoantibodies and the B-cell clonal expansions that develop
with age. Aging is also associated with a decreased diversity of the antibody
response reflected in the preferential loss of IgG and high affinity antibodies
following immunization with a foreign antigen. Many of these changes can be
traced to an impaired capacity of T cells to support isotype switching and
somatic mutation in the periphery and the generation of a diverse B-cell
repertoire from bone marrow B-cell precursors.
PMID- 10689140
TI - Thymic atrophy in the mouse is a soluble problem of the thymic environment.
AB - Age related deterioration in the function of the immune system has been
recognised in many species. The clinical presentations of such immune dysfunction
are an age-related increased susceptibility to certain infections, and an
increased incidence of autoimmune disease and certain cancers. Laboratory
investigations reveal a reduced ability of the cells from older individuals,
compared with younger individuals, to perform in functional in vitro assays.
These manifestations are thought to be causally linked to an age associated
involution of the thymus, which precedes the onset of immune dysfunction.
Hypotheses to account for the age-related changes in the thymus include: (i) an
age related decline in the supply of T cell progenitors from the bone marrow (ii)
an intrinsic defect in the marrow progenitors, or (iii) problems with
rearrangement of the TCR beta chain because of a defect in the environment
provided by the thymus. We have analysed these possible options in normal mice
and also in mice carrying a transgenic T cell receptor. The results from these
studies reveal no age related decline either in the number of function of T cell
progenitors in the thymus, but changes in the thymic environment in terms of the
cytokines produced. We have shown that specific cytokine replacement therapy
leads to an increase in thymopoiesis in old animals.
PMID- 10689141
TI - Evidence for thymic function in the elderly.
AB - The thymus represents the major site of lymphopoiesis of T-cell receptor (TCR)
alphabeta T-cells. Age-related involution may affect its potential to
reconstitute T-cells that are lost during HIV infection, chemotherapy, and bone
marrow transplantation. However, there is mounting evidence that the age-related
changes in the thymus are quantitative, not qualitative, and recent data suggest
that the adult thymus can indeed contribute to T-cell reconstitution. Using newer
methods to assess thymic function, it can be shown that the increases in naive T
cell numbers in patients receiving antiretroviral therapy for AIDS are largely
derived from the thymus. This provides direct evidence for the functional
capacity of the adult thymus.
PMID- 10689142
TI - Stimulation of memory T cells by cytokines.
AB - Mature T cells can be classified on the basis of cell surface markers into naive-
and memory-phenotype cells. These phenotypically-defined subsets exhibit distinct
kinetic behaviour in vivo. Thus, naive-phenotype T cells persist long-term in a
non-dividing state, while memory-phenotype T cells include cycling cells and have
a more rapid rate of turnover. We have investigated the possibility that the
different kinetic behaviour of naive- and memory-phenotype T cells reflects a
differential responsiveness to cytokines. It was discovered that memory-, but not
naive-, phenotype T cells were stimulated to proliferate by a variety of
infection-induced cytokines. These results suggest that cytokines contribute to
the high background rate of turnover exhibited by memory T cells.
PMID- 10689143
TI - The defects in effector generation associated with aging can be reversed by
addition of IL-2 but not other related gamma(c)-receptor binding cytokines.
AB - Aged naive CD4 T cells produce low levels of IL-2, leading to inefficient
generation of effectors. The cells expand poorly, giving rise to few effectors
with less activated phenotypes and reduced ability to produce cytokines. The aged
cells also respond less vigorously in vivo. Addition of exogenous IL-2 or other
gamma(c) receptor-signaling cytokines, restores expansion. However, only
effectors generated in the presence of IL-2, are able to produce IL-2 in normal
amounts and to become polarized to secrete Th2 cytokines. The defect in IL-2
production may be the only critical deficiency of aged naive CD4 T cells.
Importantly, memory CD4 T cells generated from the IL-2 "restored" effectors are
also deficient in IL-2 production, suggesting that a heritable change occurs
during aging which effects production of IL-2 by resting naive and memory CD4 T
cells, but not by optimally generated effectors.
PMID- 10689144
TI - Effect of aging on T lymphocyte activation.
AB - Studies of the early stages of T-cell activation reveal that T cells from aged
mice show multiple abnormalities within the first few minutes after stimulation,
including decline in the activation of the Raf-1/MEK/ERK kinases and in JNK
protein kinase. Zap-70 kinase associated with the CD3zeta chain shows a 2-fold
increase with age in resting CD4 T cells, despite a three-fold decline with age
in the levels of tyrosine phosphorylation of CD3zeta; nonetheless, there is no
effect of aging on Zap-70 kinase function in activated T cells as measured by in
vitro kinase methods. Age-related impairment of the translocation of PKCθ
from cytoplasm to the site of T-cell interaction with antigen-presenting cells
may underlie downstream defects in the activation cascade.
PMID- 10689145
TI - Costimulatory mechanisms in the elderly.
AB - Aging is associated with the progressive increase of T cells that lack expression
of the CD28 costimulatory molecule. Because CD28/B7 signal transduction is
required for proliferation, T cells lacking CD28 gene expression are incapable of
clonal expansion. To determine whether CD28- T cells are a separate lineage or,
alternatively, are the progeny of formerly CD28+ T cells, we performed cell
culture longitudinal analysis on the same population of T cells over time.
Repeated antigen-induced T cell division ultimately leads to irreversible cell
cycle arrest, shortened telomeres, loss of telomerase inducibility, and total
absence of expression of CD28. This in vitro model has elucidated a novel facet
of T cell biology that may explain the increased incidence of infection and
cancer in the elderly.
PMID- 10689146
TI - In vitro senescence models for human T lymphocytes.
AB - Immunosenescence is an age-associated dysregulation of immune function which may
contribute to the increased susceptibility of the elderly to infectious disease.
Although age-associated changes are measurable in the innate immune system, it is
the adaptive arm of the immune system which is particularly susceptible to the
deleterious effects of ageing, especially the T cell compartment. In this review,
the characteristics of longitudinal ageing in cultured monoclonal human T cell
populations will be summarized. It will be argued that parallels between this in
vitro model and T cell senescence in vivo suggest the use of such models to
screen for interventions ameliorating immunosenescence in vivo.
PMID- 10689147
TI - Mucosal vaccination and immune responses in the elderly.
AB - To develop a mucosal vaccine strategy for the elderly, we have compared mucosal
and systemic immune responses between aged (12-14 months) and young adult (8-12
weeks) mice. Both aged and young mice were immunized weekly with three oral doses
of 1 mg of ovalbumin (OVA) and 10 microg of cholera toxin as adjuvant. Although
elevated levels of OVA-specific systemic IgG and mucosal IgA Ab responses were
seen in young mice, aged mice showed impaired antigen-specific mucosal and
systemic immune responses. These results suggest that mucosal immunity is down
regulated in aged mice.
PMID- 10689148
TI - Site-directed immune responses in DNA vaccines encoding ligand-antigen fusions.
AB - One of the key limitations to DNA vaccines is lack of efficacy. We found that the
spleen was a superior injection site to the dermis or muscle for inducing immune
responses. To target sites of immune induction more practicably, antigen (human
IgG1) was fused with two ligands, L-selectin (L-SEL-hIg) or CTLA4 (CTLA4-hIg) the
receptors of which are found on high endothelial venule cells in lymph nodes and
antigen presenting cells, respectively. Antibody and lymphocyte proliferative
responses were increased. We now show that dimerization is critical for this
enhancement, presumably because of avidity considerations. The hinge of hIgG3 can
replace that of hIgG1 as a dimerization moiety. Fusion of other antigens e.g.
ovalbumin and a malaria antigen AMA-1 have confirmed that CTLA4 induces an
enhanced antibody response. Notably, in a challenge model, we have shown that
CTLA4 also improves efficacy.
PMID- 10689149
TI - Immunity to influenza in the elderly.
AB - Influenza is caused by a constantly varying segmented RNA virus that necessitates
yearly review of vaccine composition. Humans over the age of 65 years are
considered at high risk from influenza; during influenza epidemics the rate of
hospitalization in the elderly is very high and up to 90% mortality can occur.
Vaccination of the elderly has been shown to be efficacious and cost effective
but immunological senescence in the institutionally confined frail elderly is
demonstrated by failure to induce herd immunity after vaccination. Reductions in
B- and T-cell immunity and in levels of interleukin-2 are age related. Attempts
to increase the immunoresponsiveness of the elderly to influenza vaccines have
given mixed results. The most convincing evidence is in rodents where dietary
caloric restriction has been shown to enhance viral immunity.
PMID- 10689150
TI - Approaches to improved influenza vaccination.
AB - Inactivated influenza vaccine (Ivac) has had an important impact on reducing
attack rates of influenza and reducing the severity of illness amongst the
vaccinees who still acquire infection. Ivac is most efficacious amongst young,
otherwise healthy subjects and least effective against elderly at high risk. This
is in part because Ivac does not appear to significantly reduce infection rates
and in part because response rate and final antibody titer are lower in the
elderly. Therefore Ivac does not eliminate disease in the elderly who are prone
to complications when any virus replication occurs. Simultaneous administration
of intra-nasal live attenuated influenza vaccine (Livac) and Ivac reduces the
infection rate and thus illness rate amongst high-risk elderly. Presumably this
is because of the ability of Livac to stimulate secretory antibody which
neutralizes virus at the mucosal surface. Other approaches are examining the
benefit of baculovirus recombinant vaccine or adjuvanted Ivac to determine if the
higher serum antibody these vaccines produce compared to Ivac, will diffuse onto
the mucosal surfaces and in a similar fashion, neutralize virus at that site.
PMID- 10689151
TI - Local SIgA response following administration of a novel intranasal inactivated
influenza virus vaccine in community residing elderly.
AB - Community-residing elderly were immunized twice intranasally three weeks apart
with a new inactivated whole influenza vaccine. A control group was immunized
intramuscularly with conventional influenza vaccine. Local antibody response was
detected in about 50% of intranasally immunized subjects compared to about 20% of
intramuscularly immunized subjects, to the three viral strains. Increasing the
incidence of elevated IgA response may prevent influenza at its early stages thus
reducing complications in the elderly.
PMID- 10689152
TI - Vaccination of immunocompetent elderly subjects with a live attenuated Oka strain
of varicella zoster virus: a randomized, controlled, dose-response trial.
AB - After primary infection in childhood, varicella zoster virus (VZV) remains latent
in the dorsal route ganglia. Its reactivation later in life can lead to a zoster
episode. VZV-specific, T-cell-mediated immunity (VZV-CMI) is likely to be
important in preventing symptomatic reactivation. As CMI declines with age, a
vaccine enhancing VZV-CMI might be effective in decreasing the incidence or
severity of zoster in elderly subjects. A randomized, double blind controlled
trial assessing CMI responses of elderly subjects immunized with a live
attenuated, VZV-Oka vaccine was conducted. Two hundred healthy volunteers (55-75
years of age) received either a single injection of the VZV vaccine (PMC),
containing 3200 (Oka 3200), 8500 (Oka 8500), or 41,650 (Oka 41650) PFU of live
VZV, or a pneumococcus vaccine control group (Pneumo 23((R)). The immune response
to VZV was assessed by measuring the T-cell response to VZV antigens, i.e.
proliferation (stimulation index, SI), precursor cell frequency (PCF), cytokine
secretion, and antibody titers. Six weeks post-vaccination, VZV-specific SI
(adjusted mean values) was significantly greater (P<0.0001) in the 3 vaccine
groups (with SI=5. 6 for Oka 3200; SI=5.0 for Oka 8500, and SI=7.2 for Oka
41,650) than in the control group (SI=2.9). The increase in PCF was striking,
with 72.4, 91.2 and 85.1 precursors per million cells respectively in these 3
vaccine groups, vs 26.3 in the control group. No significant IL-4 secretion was
observed in any subject, whereas the presence of IFN-gamma secretion was found to
correlate with good responder status. The increase of these CMI parameters did
not depend upon the titer of virus injected. Geometric mean titers of VZV
antibodies increased in all vaccine groups and remained unchanged in the control
group. Nevertheless, no correlation between the antibody response and the cell
mediated response was found. Live attenuated VZV vaccine caused a significant
increase in VZV-CMI in a healthy, elderly population. No relationship between
vaccine dose and the intensity of the specific response was found.
PMID- 10689153
TI - The potential to use PspA and other pneumococcal proteins to elicit protection
against pneumococcal infection.
AB - Pneumococcal proteins, alone, in combination with each other, or in combination
with capsular polysaccharide-protein conjugates may be useful pneumococcal
vaccine components. Four proteins with a potential for use in vaccines are PspA,
pneumolysin, PsaA, and PspC. In a mouse model of carriage, PsaA and PspC were the
most efficacious vaccine proteins. Of these, PsaA was the best at eliciting
protection against carriage. However, a combination of PspA and pneumolysin may
elicit stronger immunity to pulmonary infection and possibly sepsis than either
protein alone. Recently, a phase one trial of a recombinant family 1 PspA was
completed in man. PspA was observed to be safe and immunogenic. Injection of 0.1
ml of immune serum diluted to 1/400 was able to protect mice from fatal infection
with S. pneumoniae. Under these conditions, pre-immune serum was not protective.
The immune human serum protected mice from infections with pneumococci expressing
either of the major PspA families (1 and 2) and both of the pneumococcal capsular
types tested: 3 and 6.
PMID- 10689154
TI - Enhancement of immunocompetence in tuberculosis by DNA vaccination.
AB - Our studies in mice show that DNA vaccines, initially designed to prevent
infection, can have a dramatic therapeutic action too. In heavily infected mice,
simply by giving DNA vaccination, the immune response can be caused to switch
from one that is relatively inefficient and gives bacterial stasis to one that
kills the bacteria, and persistent bacteria can be eliminated. Adoptive transfer
of protection with T cell clones and in vitro tests of clone function indicate
that the effects are probably mainly mediated by antigen specific CD8+/CD4
/CD44hi T cells that both produce gamma-interferon and kill the bacteria during
granule-dependent lysis of infected macrophages. We can speculate that
application of such immunotherapy in conjunction with conventional
chemotherapeutic antibacterial drugs might result in faster or more certain cure
of the disease in man. Furthermore, similar vaccines used prophylactically and
therapeutically might be able to both prevent establishment of this persistent
state and eliminate it if it is already established.
PMID- 10689155
TI - Human immunosenescence: the prevailing of innate immunity, the failing of
clonotypic immunity, and the filling of immunological space.
AB - According to the remodeling theory of aging we proposed several years ago, the
current data on human immunosenescence depicts a complex scenario where
clonotypical immunity deteriorates, while ancestral innate/natural immunity is
largely conserved or even up-regulated with age. Under an evolutionary
perspective, antigens are the cause of a persistent life-long antigenic stress,
responsible for the accumulation of effector CD8+/CD28- T cells, the decrease of
naive T cells (CD95-) and the marked shrinkage of T cell repertoire with age.
Concomitantly, NK cytotoxicity, chemotaxis, phagocytosis and complement
activities remain unaffected or negligibly affected, in comparison to
clonotypical immunity. Thus, immunosenescence is not a random deteriorative
phenomenon but appears to inversely recapitulate an evolutionary pattern. On the
whole, immunosenescence can be envisaged as the result of the continuous
challenge of the unavoidable exposure to a variety of potential antigens
(viruses, bacteria, but also food and self molecules among others). From this
perspective antigens are nothing else than a particular type of stressor and
immunosenescence appears to be the price paid to immunological memory, i.e. one
of the main characteristics of the most evolutionary recent and sophisticated
type of immunity. Together with the age-related thymic involution, and the
consequent age-related decrease of thymic output of new T cells, this situation
leaves the body practically devoid of virgin T cells, and thus likely more prone
to a variety of infectious and non infectious diseases.
PMID- 10689156
TI - Is immune senescence reversible?
AB - Many genes have been shown to be involved in the decline in immune function of
the elderly. However, normal numbers of myeloid and lymphoid colonies can be
grown from elderly bone marrow under optimal conditions and some thymic function
is preserved well into adult life. It may also be possible to reverse partially
declining thymic function by IL-7 treatment. Peripheral B and T cells show
evidence of dysregulation with production of large clones, changes in subset
distribution and altered signalling and cytokine production, particularly
decreased IL-2 production in the mouse. The identification of these defects may
lead to relatively simple procedures to improve vaccination for the elderly.
PMID- 10689157
TI - Complement-resistant Moraxella catarrhalis forms a genetically distinct lineage
within the species.
AB - Moraxella catarrhalis is a bacterial species that has been implicated in 15-20%
of all cases of otitis media in the USA and the complement-resistant variant of
M. catarrhalis has been considered particularly pathogenic. A collection of
geographically diverse, complement-sensitive (n=28) and -resistant strains (n=47)
of M. catarrhalis was assembled in order to analyse the bacterial population
structure. All strains were identified as M. catarrhalis by conventional
microbiological and biochemical methods. Amplification of the small subunit (ssu)
ribosomal RNA gene followed by restriction fragment length polymorphism (RFLP)
analysis did not reveal consistent differences between serum-susceptible and
resistant M. catarrhalis isolates. Interestingly, upon automated ribotyping using
the Qualicon RiboPrinter(R) microbial characterisation system, the complement
sensitive and -resistant strains segregated into two groups. This suggested the
existence of two clearly distinguishable lineages within the species M.
catarrhalis. This observation was corroborated by pulsed field gel
electrophoresis (PFGE) of DNA macro-restriction fragments, a non-ribosomal PCR
RFLP procedure and random amplification of polymorphic DNA (RAPD) analysis. All
procedures grouped the two variants similarly. Redefinition of the taxonomic
status of complement-resistant M. catarrhalis or even the definition of a new
species may be opportune.
PMID- 10689158
TI - Carbon catabolite repression in plant pathogenic fungi: isolation and
characterization of the Gibberella fujikuroi and Botrytis cinerea creA genes.
AB - The creA genes of two plant pathogenic fungi, the gibberellin-producing rice
pathogen Gibberella fujikuroi and the gray mold Botrytis cinerea, were isolated
and characterized. The deduced amino acid sequences of both glucose repressors
are 64% identical to each other and 59% (G. fujikuroi) and 61% (B. cinerea)
identical to the CreA protein of Aspergillus nidulans. The zinc finger regions of
the Gibberella and Botrytis CreA proteins shared 98% identity with the
corresponding zinc finger region of the A. nidulans protein, and studies by
complementation of a creA null mutant of A. nidulans showed that the proteins are
functional homologues of A. nidulans CreA. Northern blot analysis revealed that
creA transcript levels are independent of the carbon source in both fungi.
PMID- 10689159
TI - Signal sequence and alanine-rich region of streptococcal protein antigen A of
Streptococcus sobrinus can direct localization of alkaline phosphatase to the
periplasm of Escherichia coli.
AB - Streptococcal protein antigen A (SpaA) of Streptococcus sobrinus is expressed on
the surface of cells and extracellularly. TnphoA which lacks signals for
transcription and membrane transport of Escherichia coli alkaline phosphatase was
used to analyze the sequences necessary for transport of a SpaA/PhoA fusion
protein across the cytoplasmic membrane to the periplasm of E. coli cells. Of 15
alkaline phosphatase-producing isolates analyzed, all were found to localize more
than 85% of the SpaA/PhoA hybrid protein to the periplasm of E. coli cells. From
DNA sequence analysis, all were found to have TnphoA inserted into an identical
site. The insertion site of TnphoA was downstream from the coding sequence that
generates four tandemly repeated alanine-rich sequences of 82 amino acid
residues. These results suggest that in addition to the signal sequence, mature
protein sequences containing alanine-rich repeat sequences may play a role in the
export of the SpaA protein across a bacterial membrane.
PMID- 10689160
TI - Characterisation of a novel interspersed Toxoplasma gondii DNA repeat with
potential uses for PCR diagnosis and PCR-RFLP analysis.
AB - A novel Toxoplasma gondii interspersed repeat element (TgIRE), present in most of
the tachyzoite chromosomes, was characterised. Two regions on the TgIRE sequence
showed high identity to two different T. gondii expressed sequence tag cDNAs of
unknown function, which seems to be TgIRE pseudogenes. Two set of primers were
designed, 2-2' and 2-3, that amplify products of 1.02 and 0.62 kb, respectively.
T. gondii DNA from RH and Me49 strains was amplified with TgIRE 2-2' primers, and
the respective 1.02 kb products were digested with several endonucleases.
Different fragment patterns by gel electrophoresis were found only with MboI.
Sensitivity analysis revealed that the set 2-3 was more sensitive than 2-2',
detecting by gel visualisation the amount of DNA equivalent to 1 and 10
parasites, respectively.
PMID- 10689161
TI - Detection of the ADP-ribosyltransferase toxin gene (cdtA) and its activity in
Clostridium difficile isolates from Equidae.
AB - Clostridium difficile is an antibiotic-associated emerging pathogen of humans and
animals. Thus far three toxins of C. difficile have been described: an
enterotoxin (ToxA), a cytotoxin (ToxB) and an ADP-ribosyltransferase (CDT). In
the present work we describe the first isolation of CDT producing C. difficile
from Equidae with gastro-intestinal disease. Out of 17 C. difficile strains
isolated from Equidae, 11 were positive for the genes tcdA and tcdB encoding ToxA
and ToxB. In addition four of these 11 isolates were positive for the cdtA gene
encoding the catalytic subunit of the ADP-ribosyltransferase CDT. Interestingly
none of the isolates derived from canines (41 isolates) and felines (4 isolates)
harboured the cdtA gene. In C. difficile field isolates which contained the cdtA
gene, ADP-ribosyltransferase activity could also be detected in culture
supernatants indicating expression and secretion of CDT. All strains were
associated with intestinal disorders, but no association was found for the
occurrence of toxins with a specific clinical diagnosis.
PMID- 10689162
TI - Properties of Aspergillus niger citrate synthase and effects of citA
overexpression on citric acid production.
AB - Using a combination of dye adsorption and affinity elution we purified
Aspergillus niger citrate synthase to homogeneity using a single column and
characterised the enzyme. An A. niger citrate synthase cDNA was isolated by
immunological screening and used to clone the corresponding citA gene. The
deduced amino acid sequence showed high similarity to other fungal citrate
synthases. After processing upon mitochondrial import, the calculated M(r) of A.
niger citrate synthase is 48501, which agrees well with the estimated molecular
mass of the purified protein (48 kDa). In addition to an N-terminal mitochondrial
import signal, a peroxisomal target sequence (AKL) was found at the C-terminus of
the protein. Whether both signals are functional in vivo is not clear. Strains
overexpressing citA were made by transformation and cultured under citric acid
producing conditions. Up to 11-fold overproduction of citrate synthase did not
increase the rate of citric acid production by the fungus, suggesting that
citrate synthase contributes little to flux control in the pathway involved in
citric acid biosynthesis by a non-commercial strain.
PMID- 10689163
TI - Evidence for a lectin in Kluyveromyces sp. that is involved in co-flocculation
with Schizosaccharomyces pombe.
AB - Co-flocculation is the aggregation of yeasts belonging to different genera or
species. Kluyveromyces bulgaricus and Kluyveromyces lactis 5c are self
flocculent, but they can also co-flocculate with the non-flocculent yeast
Schizosaccharomyces pombe 972 h(-). This co-flocculation is inhibited by D
galactose and galactose derivatives and involves the binding of a galactose
specific proteinic receptor (or lectin) of Kluyveromyces sp. to the cell wall
galactomannans of S. pombe. The proteinic receptor is strongly anchored in the
cell wall, it was partially purified by affinity chromatography using immobilized
S. pombe galactomannans. This galactose-specific proteinic receptor does not
appear to interfere in K. bulgaricus or K. lactis self-flocculation, which is
mediated by another galactose-specific lectin weakly linked at the cell wall.
PMID- 10689164
TI - Isolation and characterization of mutated FhlA proteins which activate
transcription of the hyc operon (formate hydrogenlyase) of Escherichia coli in
the absence of molybdate(1).
AB - Escherichia coli growing under anaerobic conditions produces H(2) and CO(2) by
the enzymatic cleavage of formate catalyzed by formate hydrogenlyase (FHL)
consisting of a molybdoenzyme formate dehydrogenase H (fdhF), hydrogenase 3
(hyc), and intermediate electron carriers (hyc). Transcription of both the fdhF
and hyc operons requires the activator, FhlA protein, as well as formate and
molybdate. Several fhlA mutants with an altered response to the required effector
molybdate were isolated and these FhlA mutated proteins activated hyc
transcription in the absence of molybdate, but only in the presence of formate.
Mutated protein FhlA126 carries a single mutation (R495C) in the conserved
central domain of the modular, sigma(54)-dependent, enhancer-binding protein.
FhlA57 contains two mutations; one in the unique N-terminal domain (E205K) and a
second in the central domain (P442S). Both mutations in FhlA132 are located in
the N-terminal domain (A42T and E363K). Both FhlA126 and FhlA132 proteins
activated the hyc operon even in the absence of ModE and MoeA, two components of
Mo-metabolism which are required for hyc-lac expression in wild-type E. coli.
Based on these results, a model is proposed in which the native FhlA protein
interacts with a unique form of Mo (MoeA product?) as a second effector for
optimum expression of the hyc operon in E. coli.
PMID- 10689165
TI - A preliminary survey of extended-spectrum beta-lactamases (ESBLs) in clinical
isolates of Klebsiella pneumoniae and Escherichia coli in Japan.
AB - We conducted a survey of extended-spectrum beta-lactamases (ESBLs) among 16805
Escherichia coli and 9794 Klebsiella pneumoniae clinical isolates recovered from
196 separate medical institutions during the period January 1997 to January 1998.
Using the criteria for minimal inhibitory concentrations (MICs) of oxyimino
cephalosporins of >/=8 microg ml(-1) and confirmation by double-disk test, we
detected 15 E. coli and 34 K. pneumoniae isolates producing ESBLs. Genotypes of
ESBLs determined by PCR with type-specific primers included one TEM-derived and
24 SHV-derived ESBLs, in addition to 24 Toho-1-type ESBLs, one of the major types
of ESBLs reported in Japan. Nucleotide sequence analysis of SHV-specific PCR
products revealed that SHV-12 was the dominant type of SHV-derived ESBL. In
addition, we also identified TEM-26 and SHV-2. This is the first report
characterizing TEM- and SHV-derived ESBLs in Japan.
PMID- 10689166
TI - The pseudomonas aeruginosa motR gene involved in regulation of bacterial
motility.
AB - A mini-Tn5-Hg insertion mutant derived from Pseudomonas aeruginosa W51D (W51M1)
was isolated in which mini-Tn5 insertion disrupted the motR gene showing that it
forms part of the cluster involved in bacterial motility and chemotaxis.
Characterization of the W51M1 motility behavior, and also of a PAO1 motR::mini
Tn5-Hg mutant, suggests that the product of the motR gene is a negative regulator
of bacterial motility which controls the number of flagella per cell.
PMID- 10689167
TI - Genomic variations of Mycoplasma capricolum subsp. capripneumoniae detected by
amplified fragment length polymorphism (AFLP) analysis.
AB - The genetic diversity of Mycoplasma capricolum subsp. capripneumoniae strains
based on determination of amplified fragment length polymorphisms (AFLP) is
described. AFLP fingerprints of 38 strains derived from different countries in
Africa and the Middle East consisted of over 100 bands in the size range of 40
500 bp. The similarity between individual AFLP profiles, calculated by Jaccard's
coefficient, ranged from 0.92 to 1.0. On the basis of the polymorphisms detected,
the analysed strains can explicitly be grouped into two major clusters,
equivalent to two evolutionary lines of the organism found by 16S rDNA analysis.
The present data support previous observations regarding genetic homogeneity of
M. capricolum subsp. capripneumoniae, and confirm the two evolutionary lines of
descent found by analysis of 16S rRNA genes.
PMID- 10689168
TI - Energetics of the effect of acetic acid on growth of Saccharomyces cerevisiae.
AB - In batch cultures of a respiratory deficient mutant of Saccharomyces cerevisiae
the maximum specific growth rate and the yield coefficient decreased, but the
specific glucose consumption rate increased, in the presence of acetic acid. The
ATP yield decreased from approximately 14 to 4 g biomass (mol ATP)(-1) when the
concentration of acetic acid increased from 0 to 170 mM. Intracellular
acidification was much weaker than previously reported for non-adapted cells. A
linear relation was obtained between the ATP specific production rate and the
uptake rate of acetic acid, suggesting that about 1 mol ATP is consumed per mol
of acetic acid diffusing into the cells.
PMID- 10689169
TI - Changes to water repellence of soil caused by the growth of white-rot fungi:
studies using a novel microcosm system.
AB - A microcosm system is described which permits assessment of the progressive
growth of filamentous fungi through soil. We report on its application to measure
the effects of Coriolus versicolor and Phanerochaete chrysosporium upon the
sorptivity and water repellence of a mineral soil, measured using a miniature
infiltration device. Both fungal species caused moderate sub-critical repellence.
Since the pore structure was unaffected, the repellence was probably due to
hydrophobic substances of fungal origin. This is the first report of changes in
soil repellence caused by the growth of potential xenobiotic bioremediating
fungi. The potential consequences are discussed.
PMID- 10689170
TI - Clonal turnover of enterohemorrhagic Escherichia coli O157:H7 in experimentally
infected cattle.
AB - A total of 401 enterohemorrhagic Escherichia coli (EHEC) O157:H7 isolates from
two experimentally infected calves were analyzed using molecular biological
methods. Genetic differences detected by pulsed-field gel electrophoresis were
observed between the inoculated and recovered strains as early as 1 day post
inoculation. The loss of the inoculated clone was observed in one calf.
Replication and dissemination of the EHEC O157:H7 strains that mutated in cattle
may result in the diversification of this organism among cattle populations.
PMID- 10689171
TI - Characterisation of extended-spectrum beta-lactamases of the SHV family using a
combination of PCR-single strand conformational polymorphism (PCR-SSCP) and PCR
restriction fragment length polymorphism (PCR-RFLP).
AB - Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) has
been developed to extend the identification of SHV beta-lactamases previously
characterised by PCR-single strand conformational polymorphism (PCR-SSCP)
analysis alone. Eight bacteria, each producing a different SHV beta-lactamase,
were used in this study. These bacteria harbour bla(SHV-1), bla(SHV-2a), bla(SHV
3), bla(SHV-4), bla(SHV-5) (two strains), bla(SHV-11) and bla(SHV-12). All
isolates were characterised by PCR-SSCP and PCR-RFLP with DdeI and NheI
digestion. By a combination of these techniques, the genes encoding these beta
lactamases could be differentiated from each other. In addition, the PCR-RFLP
technique theoretically can be applied to distinguish the genes encoding SHV-7,
SHV-9, SHV-10, SHV-15, SHV-17 and SHV-24 from those encoding other SHV variants.
We report a simple PCR-RFLP technique that can be used in epidemiological studies
to enable the rapid characterisation of known SHV beta-lactamases in a
combination with the previously published PCR-SSCP analysis.
PMID- 10689172
TI - Human milk fractions inhibit the adherence of diffusely adherent Escherichia coli
(DAEC) and enteroaggregative E. coli (EAEC) to HeLa cells.
AB - Binding to a specific receptor is an essential step for most enteropathogens to
initiate an intestinal infection. We analyzed the inhibitory effect of human milk
and its protein components on adhesion of two diarrheagenic Escherichia coli
strains, diffusely adherent E. coli (DAEC) and enteroaggregative E. coli (EAEC),
to HeLa cells. Defatted milk, whey proteins, immunoglobulin and non
immunoglobulin fractions, in concentrations lower than usually found in whole
milk, inhibited both DAEC and EAEC adhesion, indicating that human milk
components may contribute to the defense of the infants against enteropathogens.
PMID- 10689173
TI - Response of soybean rhizosphere communities to human hygiene water addition as
determined by community level physiological profiling (CLPP) and terminal
restriction fragment length polymorphism (TRFLP) analysis.
AB - In this report, we describe an experiment conducted at Kennedy Space Center in
the biomass production chamber (BPC) using soybean plants for purification and
processing of human hygiene water. Specifically, we tested whether it was
possible to detect changes in the root-associated bacterial assemblage of the
plants and ultimately to identify the specific microorganism(s) which differed
when plants were exposed to hygiene water and other hydroponic media. Plants were
grown in hydroponics media corresponding to four different treatments: control
(Hoagland's solution), artificial gray water (Hoagland's+surfactant), filtered
gray water collected from human subjects on site, and unfiltered gray water.
Differences in rhizosphere microbial populations in all experimental treatments
were observed when compared to the control treatment using both community level
physiological profiles (BIOLOG) and molecular fingerprinting of 16S rRNA genes by
terminal restriction fragment length polymorphism analysis (TRFLP). Furthermore,
screening of a clonal library of 16S rRNA genes by TRFLP yielded nearly full
length SSU genes associated with the various treatments. Most 16S rRNA genes were
affiliated with the Klebsiella, Pseudomonas, Variovorax, Burkholderia, Bordetella
and Isosphaera groups. This molecular approach demonstrated the ability to
rapidly detect and identify microorganisms unique to experimental treatments and
provides a means to fingerprint microbial communities in the biosystems being
developed at NASA for optimizing advanced life support operations.
PMID- 10689174
TI - Proline accumulation by mutation or disruption of the proline oxidase gene
improves resistance to freezing and desiccation stresses in Saccharomyces
cerevisiae.
AB - We examined the role of intracellular proline under freezing and desiccation
stress conditions in Saccharomyces cerevisiae. When cultured in liquid minimal
medium, the proline-nonutilizing mutant containing the put1 mutation (proline
oxidase-deficient) produced more intracellular proline, and increased the cell
survival rate as compared to the wild-type strain after freezing and desiccation.
We also constructed two PUT1 gene disruptants. PUT1-disrupted mutants in minimal
medium supplemented with external proline at 0.1% accumulated higher proline
levels than those of the control strains (17-22-fold). These disruptants also had
a 2-5-fold increase in cell viability compared to the control strains after
freezing and desiccation stresses. These results indicate that proline has a
stress-protective function in yeast.
PMID- 10689175
TI - The extracellular hyaluronidase gene (hylA) of Streptococcus pyogenes.
AB - Group A streptococci produce an extracellular hyaluronidase (hyaluronate lyase)
which may be associated with the spread of the organism during infection. The
gene for this hyaluronidase (hylA) encodes an 868 amino acid protein with a
molecular size of 99636 Da. Cleavage of the proposed signal peptide results in an
extracellular protein of 95941 Da. Comparison with other bacterial hyaluronidases
indicates strong similarities to the genes from Streptococcus pneumoniae,
Streptococcus agalactiae and Staphylococcus aureus. A region internal to the hylA
gene was amplified from all 175 strains of Streptococcus pyogenes tested
suggesting a widespread distribution of the gene.
PMID- 10689176
TI - Aerobic nitrate respiration in a nitrite-oxidising bioreactor.
AB - The ability of heterotrophic bacteria in a nitrite-oxidising bioreactor to
respire with nitrate as an electron acceptor was examined. Approximately 70% of
1000 heterotrophic isolates were able to express a nitrate reductase. A detailed
survey of 15 isolates showed that five expressed the azide-insensitive nitrate
reductase encoded by the napA gene. A two-round PCR amplification of the napA
gene using degenerate PCR primers and DNA sequence analysis of these products
confirmed the presence of this gene in the positive isolates. Partial 16S rDNA
products and napA products were amplified from the biomass in the bioreactor and
denaturing gradient gel electrophoresis of these products identified 21 distinct
ribotypes and 12 distinct napA sequences. The results show that the ability to
respire with nitrate as an electron acceptor under aerobic conditions is
widespread among the heterotrophic population of this bioreactor.
PMID- 10689177
TI - Transcriptional regulation of the pas gene of enterohemorrhagic Escherichia coli.
AB - The Pas protein plays a key role in the pathogenesis of enterohemorrhagic
Escherichia coli (EHEC), being required for the secretion of the Esp proteins.
Here, the transcriptional regulation of the pas gene was analyzed through the
construction of a pas::lacZ translational fusion. When bacteria were grown in
Luria Bertani medium or tissue culture medium supplemented with HEPES, a bimodal
activation curve was observed. The early phase of induction was not significantly
modified by the incubation temperature (either 25 or 37 degrees C), whereas the
second phase, which overlaps with the late exponential growth phase, was enhanced
at 37 degrees C. The early phase was also stimulated by growth on tissue culture
medium and by the addition of Ca(2+), Mn(2+)or Mg(2+) to the M9-glucose minimal
medium. Primer extension analysis showed the presence of two major starts of
transcription, which were located 58 and 60 bp upstream of the ATG-start codon of
the Pas protein, respectively. Although these sites are very close to each other,
the transcripts produced during the early induction phase mainly start on the -60
position, whereas the -58 start was activated during the second induction phase.
PMID- 10689178
TI - A second tonB gene in Pseudomonas aeruginosa is linked to the exbB and exbD
genes.
AB - The exbBD genes of Pseudomonas aeruginosa PAO were cloned by complementation of
the growth defect of an Escherichia coli exbB tolQ double mutant on iron
restricted medium. Nucleotide sequence analysis confirmed that these genes are
contiguous and preceded by a second tonB gene in this organism, which we have
designated tonB2. lacZ promoter fusions confirmed that expression of the tonB2
exbB-exbD genes is increased under conditions of iron limitation. Deletions
within any of these genes, in contrast to deletions in the first tonB gene,
tonB1, did not adversely affect growth on iron-restricted medium. On the other
hand, tonB1 tonB2 double mutants were more compromised as regards growth in an
iron-restricted medium than a tonB1 deletion, indicating that TonB2 could
partially replace TonB1 in its role in iron acquisition. TonB1 but not TonB2
deletion strains were also compromised as regards the utilization of hemin or
hemoglobin as sole iron sources, indicating that heme transport requires TonB1.
PMID- 10689179
TI - Sequence polymorphisms within the pMGA genes and pMGA antigenic variants in
Mycoplasma gallisepticum.
AB - Antigenic variants of Mycoplasma gallisepticum major surface lipoprotein, pMGA,
are encoded by a large gene family. In this study sequence analyses of the PCR
amplified pMGA genes showed two types of sequences similar to the pMGA1.2 gene in
M. gallisepticum strains. They differed in the sequence encoding a proline-rich
region (PRR) at the N-terminus of the pMGA protein. The type A genes had
sequences similar to the published pMGA1.2 gene sequence of strain S6, whereas
the type B genes lacked the second repetitive segment encoding PTPN sequence
within PRR and were similar to the published sequence of PG31 strain. Low in
vitro passages of M. gallisepticum strains isolated recently in Slovenia from
four avian species showed very different expression patterns of pMGA1.2 and
pMGA1.9 genes. Among isogenic populations of S6(B) and IHB1 strains a high
frequency of pMGA antigenic variants lacking an epitope for monoclonal antibody
(mAb) 71 was found. Strain IHB1 clones, which synthesized pMGA recognized by mAb
71, transcribed pMGA genes whose partial sequence encoded the amino acid sequence
(262)TNGDEPRSVS of the mAb 71 epitope. Other IHB1 clones synthesized pMGA
variants with different isoelectric points, lacking the epitope for mAb 71, but
expressing downstream epitopes for other mAbs. Our study suggests that a
molecular basis for pMGA antigenic variation lies in the corresponding changes at
the DNA level.
PMID- 10689181
TI - Nuclear topography of the c-myc gene in human leukemic cells.
AB - The c-myc gene plays an essential role in the regulation of the cell cycle and
differentiation. Therefore, changes of the c-myc positioning during
differentiation are of great interest. As a model system of cell differentiation,
the HL-60 and U-937 human leukemic cell lines were used in our experiments. These
cells can be induced to differentiation into granulocytes that represent one of
the pathways of blood cell maturation. In this study, changes of the topographic
characteristics of the c-myc gene (8q24), centromeric region of chromosome 8 and
chromosome 8 domain during differentiation of HL-60 and U-937 cells were detected
using fluorescence in-situ hybridisation (FISH). FISH techniques and fluorescence
microscopy combined with image acquisition and analysis (high-resolution
cytometry) were used in order to detect the topographic features of nuclear
chromatin. Increased centre of nucleus-to-gene and gene-to-gene distances of c
myc genes, centromeric region of chromosome 8 and chromosome 8 domains were found
early after the induction of granulocytic differentiation by dimethyl sulfoxide
(DMSO) or retinoic acid (RA); the size of the chromosome 8 domains was rapidly
reduced. In differentiated cells, c-myc is located at greater distances from the
centromeric regions of chromosome 8. These results support the idea that
relocation of the c-myc gene to the nuclear periphery and the condensation of the
chromosome 8 domain might be associated with the c-myc gene expression due to
common kinetics during granulocytic differentiation.
PMID- 10689182
TI - Stable shuttle vectors for Neisseria gonorrhoeae, Haemophilus spp. and other
bacteria based on a single origin of replication.
AB - An origin of replication (ori) was obtained from a naturally occurring beta
lactamase-producing plasmid isolated from Neisseria gonorrhoeae and used to
construct shuttle vectors capable of replicating in N. gonorrhoeae, Haemophilus
ducreyi, Haemophilus influenzae and Escherichia coli. Using the gonococcal proAB
genes, we complemented proline-requiring N. gonorrhoeae F62 and E. coli HB101 in
trans. The first demonstration of the expression of the green fluorescent protein
(GFP) in either N. gonorrhoeae or H. ducreyi was shown using this vector,
indicating that GFP may be a useful tool in the analysis of these organisms. This
is the first report of a gonococcal vector based on a broad host range,
genetically defined ori, and should facilitate the molecular analysis of
gonococcal and Haemophilus genes.
PMID- 10689183
TI - PEBP2alphaA/CBFA1 mutations in Japanese cleidocranial dysplasia patients.
AB - Cleidocranial dysplasia (CCD) is an autosomal dominant human bone disease whose
genetic locus has been located on chromosome 6p21, where the PEBP2alphaA/CBFA1
gene essential for osteogenesis also maps. Previously, several heterozygous
mutations in PEBP2alphaA/CBFA1 were found in CCD patients. In this study, we
identified six different types of mutations in PEBP2alphaA/CBFA1 in Japanese CCD
patients. Four cases were similar to those reported previously: two were nonsense
mutations in the Runt domain, one was a hemizygous deletion, and the other was a
missense mutation in the Runt domain which abolished the DNA-binding activity of
Runx2/PEBP2alphaA/CBFA1. The remaining two mutations were novel: one had a
heterozygous gt-to-tt mutation at the splice donor site (gt) between the exon3
intron junction, which resulted in abnormal exon3 skipping, and the other had a
mutation in exon7, which led to the introduction of a translational stop codon in
the middle of the transactivation domain. Thus, defects in either the DNA-binding
domain or transactivation domain of Runx2/PEBP2alphaA/CBFA1 can cause CCD. The
results not only provide a strong genetic evidence that mutations involving in
PEBP2alphaA/CBFA1 contribute to CCD, but also provide a useful tool to study how
Runx2/PEBP2alphaA/CBFA1 plays its pivotal role during osteoblastic
differentiation.
PMID- 10689184
TI - MSY2: a slowly evolving minisatellite on the human Y chromosome which provides a
useful polymorphic marker in Chinese populations.
AB - We present the second human Y-specific minisatellite, MSY2 (DYS440). It consists
of three or four copies of a 99-110bp repeat unit and is located about 1kb
upstream of the DBY gene. The most common allele contains four units, but a three
unit allele has arisen on at least four occasions; in chimpanzees and orangutans,
MSY2 contains only two units. It is therefore evolving slowly and provides a
particularly useful polymorphic marker for Chinese populations.
PMID- 10689185
TI - Structure of the murine Pit1 phosphate transporter/retrovirus receptor gene and
functional characterization of its promoter region.
AB - The Pit1 phosphate transporter (formerly also called Glvr-1) probably plays an
important role in regulated phosphate handling in bone-forming cells. In this
study, we describe the structure of the mouse Pit1 gene, as well as some
functional characteristics of its promoter region in murine bone cells. Screening
of a genomic library led to the isolation of two overlapping lambda clones
containing 7kb of 5' flanking region, as well as the 10 exons of the mouse Pit1
gene corresponding to the published cDNA. The translation start site is located
within exon I and the stop codon within exon X. The overall structure of the
mouse gene is very similar to that of its human homolog, except for the presence
of an additional 5' untranslated exon in human. The structure of the 5'
untranslated region of the mouse gene was thus further investigated using rapid
amplification of cDNA ends in murine ATDC5, MC3T3-E1 and Swiss 3T3 cells. The
results indicate that, compared to the published cDNA, the mouse Pit1 gene
contains in fact one additional 5' exon, which we named exon IA. Reporter gene
assays demonstrate the presence of a functional TATA box containing promoter
upstream of exon IA. This description of the murine Pit1 gene and of its promoter
region paves the way to more detailed analyses concerning the regulation of Pit1
transcription in mouse cells. Furthermore, a comparison of mouse and human
promoters will hopefully allow a better understanding of general mechanisms
regulating Pit1 expression in different species.
PMID- 10689186
TI - Mammalian genomes contain active recombinase recognition sites.
AB - Recombinases derived from microorganisms mediate efficient site-specific
recombination. For example, the Cre recombinase from bacteriophage P1 efficiently
carries out recombination at its loxP target sites. While this enzyme can
function in mammalian cells, the 34bp loxP site is expected to be absent from
mammalian genomes. We have discovered that sequences from the human and mouse
genomes surprisingly divergent from loxP can support Cre-mediated recombination
at up to 100% of the efficiency of the native loxP site in bacterial assays.
Transient assays in human cells demonstrate that such pseudo-lox sites also
support Cre-mediated integration and excision in the human cell environment.
Pseudo sites for Cre and other recombinases may be useful for site-specific
insertion of exogenous genes into mammalian genomes during gene therapy and other
genetic engineering processes.
PMID- 10689187
TI - Gene structure and chromosome mapping of mouse transcription elongation factor S
II (Tcea1).
AB - We report the organization and chromosome localization of the mouse transcription
elongation factor S-II gene (Tcea1). This gene was found to be a single copy gene
consisting of 10 exons spanning approximately 30kb. Its organization was the same
as those of the mouse testis-specific S-II gene (Tcea2) and Xenopus general S-II
gene (xTFIIS.oA), but different from that of the human S-II gene family. We also
identified a processed pseudogene (Tcea1-ps1) with a sequence highly homologous
to those of S-II cDNAs but containing a translation termination codon within its
open reading frame. Linkage analysis showed that Tcea1 and Tcea1-ps1 are mapped
on mouse chromosomes 1 and 15, respectively. Relationships between Tcea1 and S-II
cDNAs isolated so far are discussed.
PMID- 10689188
TI - Molecular structure and tissue-specific expression of the mouse pancreatic
phospholipase A(2) gene.
AB - Pancreatic phospholipase A(2) (PLA(2)) is involved with the hydrolysis of
phospholipids into lysophospholipids and unesterified fatty acids. The enzyme has
been postulated to play a key role in lipid absorption by intestinal absorptive
cells as well as in the regulation of secretin release from intestinal endocrine
cells. This manuscript reports the genomic organization and the primary sequence
of the mouse PLA(2). The results showed that the mouse PLA(2) gene contains four
exons interspersed by three introns, spans over 8kb in length, and is
considerably larger than the human PLA(2) gene. The mouse PLA(2) protein contains
146 amino acid residues, including the signal peptide. The mouse protein is
highly homologous to the rat, dog, and human enzyme, but is two residues shorter
than the human protein. Mouse PLA(2) message is synthesized predominantly in the
pancreas, but the lung also contains low levels of PLA(2) mRNA.
PMID- 10689189
TI - Matrix attachment region regulates basal beta-lactoglobulin transgene expression.
AB - Nuclear matrix attachment regions (MAR) have been implicated in the regulation of
gene expression. We have identified a region within the proximal 3'-flanking
sequences of the ovine beta-lactoglobulin (betalg) gene that interacts with the
nuclear matrix in vitro. No equivalent region was detected in the 5' flanking
region. We have investigated the role of this element in regulating betalg
expression in vitro and in vivo. Removal of the MAR did not affect the frequency
of betalg transgene expression at the mRNA level, but betalg transgenes that
lacked the MAR were expressed at a lower level than wild-type betalg transgenes.
In neither in-vitro HC11 transfection experiments nor transgenic mice was
hormonal induction of betalg expression significantly affected by MAR removal.
Nuclear run-on analysis demonstrated that the impaired basal expression of betalg
transgene loci lacking the MAR was due to a reduced transcription rate. Thus, the
single MAR enhances the basal transcriptional potential of the betalg gene.
PMID- 10689190
TI - Cloning of a calcitonin gene-related peptide receptor and a novel calcitonin
receptor-like receptor from the gill of flounder, Paralichthys olivaceus.
AB - For the first time in non-mammalian vertebrates, cDNA encoding CGRPR was isolated
from the gill cDNA library of flounder. The nucleotide sequence consists of a
237bp 5'-UTR, a 1398bp coding sequence for a 465-amino-acid protein, and a 981bp
3'-UTR. The predicted amino-acid sequence has a high degree of identity to hCGRPR
(72.3%) and rCGRPR (71.6%) and, to a lesser degree, to hCTR (55.6%) and rCTR
(59.3%). In addition, a different type of receptor cDNA was also obtained from
the gill cDNA. The nucleotide sequence contains an open-reading frame of 1380bp
to produce a 459-amino-acid protein. The open-reading frame of this receptor
shows the same degree of identity to mammalian CTR (60.2% to hCTR; 62.3% to rCTR)
and CGRPR (64.6% to hCGRPR; 64.4% to rCGRPR). However, the predicted amino-acid
sequence was more homologous to hCGRPR (60.2%) and rCGRPR (61.3%) than to hCTR
(48.8%) and rCTR (49.5%). The identity of this receptor to fCGRPR is 66.6% at the
nucleotide level and 64.2% at the amino-acid level, indicating that the receptor
is not likely to be an isoform of CGRPR. The receptor, but not fCGRPR, is
expressed in bones, suggesting the possibility that this receptor corresponds to
the flounder CTR.
PMID- 10689191
TI - The PAUSE software for analysis of translational control over protein targeting:
application to E. nidulans membrane proteins.
AB - The PAUSE software has been developed as a new tool to study translational
control over protein targeting. This makes it possible to correlate the position
of clusters of rare codons in a gene, predicted to cause a translational pause,
with the position of hydrophobic stretches in the encoded protein, predicted to
span a membrane or to act as a cleavable signal for targeting to the secretory
pathway. Furthermore, this software gathers these correlations over whole sets of
genes. The PAUSE software is described here, and its use is illustrated on a set
of membrane proteins from the fungus Emericella nidulans. Preferential distances
of about 45 codons and of about 70 codons between putative transmembrane domains
and predicted translational pauses were observed. Given that approximately 30
residues are required to span the large ribosomal subunit, the predicted pauses
would therefore occur when the hydrophobic domain starts protruding from the
ribosome ('+45 pause'), or fully protrudes as a hairpin ('+70 pause'). Thus,
these specific pauses might reflect a translational control over membrane protein
targeting or early recognition ('+45 pause'), and over insertion or folding ('+70
pause').
PMID- 10689192
TI - Description and characterization of IS994, a putative IS3 family insertion
sequence from the salmon pathogen, Renibacterium salmoninarum.
AB - Renibacterium salmoninarum, a slowly growing, Gram-positive bacterium, is
responsible for bacterial kidney disease in salmonid fishes world-wide. To date,
no mobile genetic elements have been reported for this pathogen. Here, we
describe the first insertion sequence (IS) identified from R. salmoninarum. This
element, IS994, has a significant predicted amino acid sequence homology (64.8
and 71.9%) to the two open reading frames encoding the transposase of IS6110 of
Mycobacterium tuberculosis. Protein parsimony and protein distance matrix
analyses show that IS994 is a member of group IS51 of the IS3 family. From a
conservative estimate, there are at least 17 chromosomal insertions of IS994 or
closely related elements. Sequence analysis of seven of these loci reveals single
nucleotide polymorphisms throughout the element (including the terminal inverted
repeats), a 15bp insertion in three of the seven loci, and an absence of flanking
direct repeats or conserved insertion site. Restriction fragment length
polymorphism analysis of XbaI-digested chromosomal DNA shows variations among
European and North American isolates, indicating that IS994 may be a useful
molecular marker for epizootiological studies.
PMID- 10689193
TI - Isolation and functional characterization of a temperature-sensitive mutant of
the yeast Saccharomyces cerevisiae in translation initiation factor eIF5: an eIF5
dependent cell-free translation system.
AB - Eukaryotic translation initiation factor 5 (eIF5) interacts with the 40S
ribosomal initiation complex (40S.eIF3.AUG.Met-tRNA(f).eIF2.GTP) to promote the
hydrolysis of bound GTP. In Saccharomyces cerevisiae, eIF5, a protein of 45346Da,
is encoded by a single-copy essential gene, TIF5. In this paper, we have isolated
a temperature-sensitive S. cerevisiae strain, TMY5-1, by replacing the wild-type
chromosomal copy of TIF5 with one mutagenized in vitro. The mutant yeast cells
rapidly cease protein synthesis when grown under non-permissive conditions, lose
polyribosomes and accumulate free 80S ribosomes. Further characterization of
mutant eIF5 showed that the mutant protein, expressed in Escherichia coli, is
defective both in its interaction with eIF2 as well as in mediating the
hydrolysis of GTP bound to the 40S initiation complex and consequently in the
formation of the 80S initiation complex. Additionally, the availability of a
yeast strain containing temperature-sensitive mutation in the eIF5 gene allowed
us to construct a cell-free translation system that was dependent on exogenously
added eIF5 for translation of mRNAs in vitro.
PMID- 10689194
TI - Hyperactivation of the Drosophila Hop jak kinase causes the preferential
overexpression of eIF1A transcripts in larval blood cells.
AB - Jak kinase-Stat protein pathways play a critical role in the response of blood
cells to a range of cytokines and growth factors. We are using the fruit fly,
Drosophila melanogaster, as a model system to elucidate additional components of
Jak-Stat pathways, and to determine how abnormalities in this pathway lead to
hematopoietic leukemia-like defects. To identify downstream targets, we conducted
a molecular screen for genes whose transcripts are overexpressed in response to
activation of the Drosophila Hop Jak kinase. We identified a Drosophila homolog
of eIF1A, a eukaryotic initiation factor found in humans and other eukaryotes. D
eIF1A is highly overexpressed in the hemocytes and lymph glands of third instar
larvae carrying the dominant, gain-of-function mutation hop(Tum-l). A
quantitative comparison of poly(A)(+) RNA levels between D-eIF1A and other known
Drosophila translation initiation factors indicates that D-eIF1A transcripts
preferentially overaccumulate in response to the hyperactive Hop pathway. Our
results support the model that D-eIF1A is one of the target genes through which
the Drosophila Jak kinase pathway regulates hemocyte development.
PMID- 10689195
TI - Isolation and characterization of copia-type retrotransposons in Arabidopsis
thaliana.
AB - We isolated two copia-type retrotransposons from Arabidopsis thaliana. We named
these elements AtRE1 (Arabidopsis thaliana Retro Element 1) and AtRE2. Nucleotide
sequence analysis revealed that both elements have long terminal repeats (LTRs),
and that their internal sequences include one large open reading frame that could
encode Gag protein, protease, integrase, reverse transcriptase, and RNaseH. The
deduced amino acids sequences contain several domains that are conserved among a
large family of retrotransposons. The primer binding site for first-strand DNA
synthesis and the polypurine tract for second-strand DNA synthesis existed at
corresponding positions. A 5bp target site duplication (TSD) sequence was also
found in the flanking region of LTRs. Southern hybridization and sequence
determination of the flanking region demonstrated that AtREs exist at different
loci in the two A. thaliana ecotypes Columbia and Landsberg erecta. Moreover,
AtRE2 exists at two loci in Landsberg erecta, in contrast to the existence of
only one copy in Columbia. These findings suggest that AtREs were recently
transfected via some mediators or that AtREs were transposed after
differentiation of the two ecotypes. One cDNA clone derived from the transcripts
of AtRE1 was isolated, and the nucleotide sequence showed that this RNA was
transcribed in the antisense direction. RT-PCR analysis revealed that AtRE1 was
transcribed in both directions. This result suggests that the antisense RNA
controls the expression of AtRE1 at the post-transcriptional level.
PMID- 10689196
TI - Molecular organization of the mouse gastrin-releasing peptide receptor gene and
its promoter.
AB - The murine gastrin-releasing peptide receptor (mGRP-R) is a member of the G
protein-coupled receptor family and mediates important physiological actions of
its specific ligand, the gastrointestinal hormone/neurotransmitter GRP, including
mitogenic properties in the mouse Swiss 3T3 fibroblasts. Glucocorticoids and
increases in intracellular cAMP are reported to alter GRP-R gene transcription,
but the molecular basis for these effects is unknown. To begin to identify
possible gene regulatory mechanisms that are responsible for modifying mGRP-R
expression, we determined its structure and investigated its basal promoter
activity. We isolated and characterized genomic bacteriophage P1 clones encoding
the mouse gastrin-releasing peptide receptor (mGRP-R). By DNA sequencing and
Southern blot analyses, we determined the protein coding region to be contained
in three exons interrupted by two introns 20 and 2kb in length. The open reading
frame of the putative GRP-R gene encodes for a 384-amino-acid protein which
demonstrates 48% identity with the mouse BRS-3 protein and 53% identity with the
mouse NMB-R protein. The mGRP-R gene locus extends over 29kb and was mapped to
the X-chromosome (DXMit20) utilizing a minisatellite polymorphism in the 5' UTR
and by fluorescent in-situ hybridization (FISH). In Swiss 3T3 cells, which
natively express mGRP-R, two gene-specific mRNA species of 3 and 7kb can be
detected by Northern blot analysis. With RNase protection assays, and
independently with inverse PCR of 5' RACE clones, common mRNA initiation sites
were identified clustered between 21 and 61bp downstream of a TTTAAA motif, which
is located 450bp upstream of the ATG translation start site. However, different
polyadenylation sites are utilized. A 2kb genomic DNA fragment extending from
2147 to 141 bases 5' to the ATG translation start was cloned into a luciferase
reporter plasmid and shown to contain promoter activity in Swiss 3T3 and COS-7
cells. Progressive promoter truncations and mutations of a cyclic AMP response
element (CRE) located 83bp upstream of the TTTAAA motif demonstrate that
transcriptional mGRP-R activation in Swiss 3T3 cells only occurs when both the
TTTAAA motif and the intact CRE site are retained. With the availability of the
full structure of the mGRP-R gene and the minimal promoter sequences reported in
this study, it will be possible in future studies to investigate the molecular
basis for transcriptional regulation of the mGRP-R gene by glucocorticoids, cAMP
and other factors.
PMID- 10689197
TI - The stachydrine catabolism region in Sinorhizobium meliloti encodes a multi
enzyme complex similar to the xenobiotic degrading systems in other bacteria.
AB - Stachydrine (proline betaine) can be used by Sinorhizobium meliloti as a source
of carbon and nitrogen. Catabolism depends on an initial N-demethylation, after
which the resultant N-methyl proline enters general metabolism. Deletion and
insertion mutagenesis demonstrated that the information necessary for catabolism
is carried on the symbiotic plasmid (pSym) distal to nodD2 and the nod-nif
cluster. Sequencing of an 8.5kb fragment spanning this region revealed four open
reading frames with functional homology to known proteins, including a putative
monooxygenase and a putative NADPH-FMN-reductase, which were shown by insertional
and frame-shift mutagenesis to be necessary for stachydrine catabolism. Other
open reading frames, encoding a putative flavoprotein and a repressor, were
judged not to be required for stachydrine catabolism, since they were not
included in a fragment capable of complementing a deletion of the entire stc
region. Sequence and mutagenesis data suggest that stachydrine is demethylated by
an iron-sulfur monooxygenase of the Rieske type with a requirement for a specific
reductase. The stc catabolic cluster, therefore, resembles xenobiotic degradation
in other bacteria and recalls rhizopine catabolism in S. meliloti. Stachydrine
appears to have multiple roles in osmoprotection, nutrition and nodulation. Genes
involved in stachydrine catabolism are also necessary for carnitine degradation;
thus, they could be important in the catabolism of a variety of root exudates and
mediate other relationships.
PMID- 10689198
TI - Valproic acid-induced alterations in growth and neurotrophic factor gene
expression in murine embryos [corrected].
AB - Although the teratogenicity of valproic acid (VPA) has been well established, the
mechanism(s) by which this anticonvulsant drug induces malformations remains
controversial. Using the combined molecular techniques of in situ-transcription
(IST) and antisense RNA (aRNA) amplification we analyzed VPA-induced alterations
in the gene expression for 10 genes within the neural tubes of embryos from two
murine strains that have been shown to differ in their susceptibility to VPA
induce neural tube defects (NTD). Pregnant dams from both SWV (susceptible) and
LM/Bc (resistant) strains were either treated with saline (control) or VPA (600
mg/kg) on gestational day (GD) 8:12 (day:hour). Neural tubes were isolated from
control or VPA exposed embryos at three gestational time points, which
represented the beginning (GD 8:18), middle (GD 9:00), and end (GD 9:12) of
neural tube closure (NTC) in both of these murine strains. Using univariant
statistics we demonstrated that in LM/Bc embryos with NTDs, the expression of
bdnf, ngf, and trk, ngf-R were significantly elevated at all three time points,
and the cytokine, cntf was significantly decreased at GD 9:00. In contrast, the
major gene alterations observed in SWV embryos were a significant increase in
tfgalpha and tgfbeta1-3 at GD 9:00. In an effort to better define the more
intricate interactions between VPA exposure and the expression of these genes, we
analyzed our data using Principal Component Analysis. The results from this
analysis demonstrated that embryos from these two stains behaved differently, not
only in response to a VPA exposure, but also under control conditions, which may
explain the multifactorial nature of NTDs in these mice.
PMID- 10689199
TI - Effects of dibutyl phthalate on reproductive function in pregnant and
pseudopregnant rats.
AB - In our previous studies, dibutyl phthalate (DBP) was found to be embryolethal and
teratogenic in rats. In this study, the effects of DBP on reproductive function
were investigated on pregnant and pseudopregnant rats. Rats were given DBP by
gastric intubation at 0, 250, 500, 750, 1000, 1250 or 1500 mg/kg on Days 0 to 8
of pregnancy and the pregnancy outcome was determined on Day 20 of pregnancy. The
same doses of DBP were given to pseudopregnant rats, with an induced decidual
cell response, on Days 0 to 8 of pseudopregnancy, and the uterine weight on Day 9
served as an index of the uterine decidualization. DBP caused significant
increases in the incidences of preimplantation loss in females successfully mated
at 1250 and 1500 mg/kg and of postimplantation loss in females having
implantations at 750 mg/kg and above. The uterine decidualization in
pseudopregnant rats was significantly decreased at 750 mg/kg and above. These
findings suggest that early embryonic loss due to DBP may be mediated, at least
in part, via the suppression of uterine decidualization, an impairment of uterine
function.
PMID- 10689200
TI - Two-generation reproduction study in rats given di-isononyl phthalate in the
diet.
AB - The potential reproductive toxicity of di-isononyl phthalate (DINP: CAS RN 68515
48-0) was assessed in one- and two-generation reproductive toxicity studies.
Groups of 30 male and female CRL : CD(SD)BR rats were given DINP via dietary
administration at levels of either 0.0, 0.5, 1, or 1.5% (one-generation study) or
0.0, 0.2, 0. 4, or 0.8% (two-generation study). There were no changes in any of
the classic reproductive parameters, i.e. mating, male or female fertility,
fecundity, gestational index, or length of gestation in either study. The overall
NOAELs for these effects were the highest Dietary Level (%)s tested,
approximately 500 mg/kg/day in the two-generation study and 1000 mg/kg/day in the
one-generation study. There were no testicular effects in parental animals
exposed as juveniles and young adults at 960 mg/kg/day in the one-generation
study. In the two-generation study, there were no testicular effects in either
the P(1) males, exposed as juveniles and young adults or the P(2) (F(1))
offspring exposed in utero, through lactation, and continuously to terminal
sacrifice. The NOAEL was 470 mg/kg/day. Offspring survival was reduced at the
1.5% level ( approximately 1100 mg/kg/day) but unaffected at the 1% level (
approximately 760 mg/kg/day). There were decreased offspring body weights both at
postnatal day (PND) 0 and during lactation; however, the PND 0 effects were only
clearly related to treatment at the 1.5% level. Weights of offspring during
lactation were significantly reduced but within the historical control range at
Dietary Level (%)s below 1%. As there was rapid recovery at the lower levels,
even though treatment continued, the toxicologic significance is unclear. Adult
survival was unaffected at any level in either study, but weight gain was
significantly reduced at the 1% level ( approximately 600 mg/kg/day). Liver and
kidney weights were elevated at Dietary Level (%)s above approximately 110
mg/kg/day, consistent with evidence from other studies of peroxisomal
proliferation at these levels. This study showed that DINP treatment does not
affect fertility or male reproductive development at doses of up to approximately
1000 mg/kg/day.
PMID- 10689201
TI - The reversible effects of raloxifene on luteinizing hormone levels and ovarian
morphology in mice.
AB - Raloxifene is a selective estrogen receptor modulator that has estrogen agonist
effects on bone and serum lipids and estrogen antagonist effects on breast and
uterine tissues. This study assessed the effects of raloxifene hydrochloride
(HCl) treatment on circulating luteinizing hormone (LH) levels and ovarian
morphology in sexually mature, 15-week-old, female CD-1 mice. Mice were
maintained on diets providing average daily doses of 0 or 233 mg/kg raloxifene
for 2 weeks (Study 1) or 0, 7.9, or 236 mg/kg raloxifene for 4 weeks (Study 2).
At the end of the treatment period, blood samples were collected every 2 hours
for 24 h in Study 1 (5 mice per group) and at 10:00 a.m. and 10:00 p.m. in Study
2 (8 mice per group). Serum LH levels were measured by radioimmunoassay. Ovarian
histomorphology was evaluated in the 10 mice per group (Study 1) and the 8 mice
per group (Study 2). For the reversibility phase (Study 2), mice were fed
untreated diets for 3 weeks; serum LH levels and ovarian histomorphology were
then assessed. Raloxifene treatment at 233 mg/kg/day for 2 weeks (Study 1)
significantly elevated circulating LH levels by 4- to 7-fold compared with
control. Raloxifene-treated mice had elevated LH levels sustained over the 24-h
sampling period and did not exhibit the preovulatory LH surge evident in some
control mice at the 4:00 p.m., 6:00 p.m., and 8:00 p. m. time points. Mice
treated with 236 mg/day raloxifene for 4 weeks (Study 2) had elevated LH levels
(4.4-fold compared to control), whereas mice exposed to 7.9 mg/kg/day raloxifene
had a slight, nonsignificant increase in LH (2-fold compared to control). In both
dose groups, LH levels were indistinguishable from controls 3 weeks after
raloxifene treatment was discontinued. The ovaries in six of the eight mice
treated with 7.9 mg/kg/day raloxifene had dilated and/or anovulatory follicles.
One mouse in this group had a single hemorrhagic follicle; however, corpora lutea
distribution was normal, indicating that ovulation was occurring. Raloxifene
treated mice in Study 1 and mice treated with a comparable raloxifene dose (236
mg/day) in Study 2 had histomorphological changes in the ovary indicative of
arrested follicular maturation, including anovulatory hemorrhagic follicles, some
developing follicles, and very few corpora lutea. At the end of the reversibility
phase, hemorrhagic follicles were no longer evident and follicular maturation and
corpora lutea distribution were normal. Raloxifene treatment in mice produces a
dose-dependent, sustained elevation in serum LH levels and is associated with
changes in ovarian follicular morphology. These changes are reversible upon
discontinuation of raloxifene treatment.
PMID- 10689202
TI - In vitro fertilization after in vivo treatment of rats with three reproductive
toxicants.
AB - One objective of these experiments was to establish a sensitive assay to evaluate
fertilizing potential of rat gametes in vitro. A second objective was to evaluate
this in vitro fertilization (IVF) assay as a method to detect in vivo effects of
reproductive toxicants on male and female gametes using three known reproductive
toxicants as model systems. The IVF assay with zona-free oocytes was more precise
than the assay with cumulus-intact oocytes in these studies (coefficients of
variation of 8.7 and 14.4%, respectively). Sperm fertilizing potential for zona
free oocytes was reduced by treatment of rats with m-dinitrobenzene (10-10 000
microg/kg) and ethylene glycol monomethyl ether (50-100 mg/kg) that had no effect
on sperm motility. Molinate (60 mg/kg for 5 days) reduced sperm fertilizing
potential concurrently with reductions in sperm motility. Neither molinate (60
mg/kg for 5 days) nor dinitrobenzene (0.002% in the drinking water for 14 days)
administered to females seemed to affect the fertilizability of their oocytes.
Ethylene glycol monomethyl ether treatment (0.15-0.25% in the drinking water for
14 days) reduced the number of ovulated oocytes. IVF is a means to evaluate
toxicant effects on female gametes and demonstrates sperm's ability to interact
with the oocyte plasma membrane.
PMID- 10689203
TI - Rat epididymal sperm motion changes induced by ethylene glycol monoethyl ether,
sulfasalazine, and 2,5-hexandione.
AB - Epididymal sperm was examined using the Hamilton-Thorne Sperm analyzer (HTM-IVOS,
version 10.6) in male rats treated with known male reproductive toxicants that
act by different mechanisms to detect effects on sperm motion. Three agents known
to produce changes in sperm motion at high exposure levels were administered at
lower levels. Ethylene glycol monoethyl ether (EGEE), sulfasalazine (SASP), and
2,5-hexandione (2,5-HD) were administered by oral gavage to adult male Sprague
Dawley rats at 250 or 500 mg/kg/day, at 300 or 600 mg/kg/day, or at 100 or 250
mg/kg/day, respectively. The males were treated with EGEE, SASP, and 2,5-HD for
35, 28, and 28 days, respectively. The males treated with EGEE and SASP were
mated with untreated females to assess male fertility. All males were examined
for body weight, testicular and epididymal weight, epididymal sperm count, and
sperm motion. The sperm motion parameters included percentage of motile sperm,
percentage of progressively motile sperm (progressive motility), curvilinear
velocity (VCL), average path velocity (VAP), straight line velocity (VSL),
amplitude of lateral head displacement (ALH), beat cross frequency (BCF),
linearity (LIN), and straightness (STR). For the male rats treated with SASP, no
treatment-related effects on percentages of motile sperm or sperm count were
observed despite impaired male fertility. However, abnormal motion of epididymal
sperm from the SASP treated males was detected by a significant reduction in mean
progressive motility, VAP, and ALH, and an increase in BCF and STR. For the males
treated with 2,5-HD for 4 weeks, most parameters generated by the HTM-IVOS
indicated decreased sperm motion despite no remarkable changes in testicular
weight, epididymal weight, or sperm count. In the EGEE-treated males at 250
mg/kg/day for 5 weeks, abnormal motion of epididymal sperm was detected by
decreased progressive motility and increased BCF, although there were no
treatment-related effects on testicular weight or male fertility. Progressive
motility was decreased in all treated groups and the difference from the control
value was of the greatest magnitude among the sperm motion parameters generated
by the HTM-IVOS. Velocity parameters (VAP, VSL, VCL) responded sensitively to
abnormal sperm motion in the SASP and 2,5-HD studies. In spite of decreased sperm
motion, BCF values were significantly increased in all treated groups except the
7-week EGEE high-dose group, where there were no motile sperm to evaluate. ALH
was significantly decreased in the treated groups in which remarkable effects on
sperm motion were noted. There were no significant changes in ALH at the low-dose
of EGEE at which only mild effects on sperm motion were observed. STR was
increased for epididymal sperm from the males treated with SASP when compared
with the controls. For the males treated with EGEE and 2,5-HD, however, STR was
decreased when compared with the controls. There were no significant differences
in LIN in any of the groups treated with SASP, in which remarkably reduced sperm
motion was detected by the other parameters. In conclusion, among the parameters
generated by the HTM-IVOS, progressive motility was significantly decreased in
all treated groups and the most valuable for detecting slight changes in sperm
motion induced by these three different target toxicants. Further investigation
with a larger set of compounds is needed to evaluate which IVOS parameters are
the most sensitive in detecting motion changes.
PMID- 10689204
TI - Histochemical tracing of bismuth in testis from rats exposed intraperitoneally to
bismuth subnitrate.
AB - The histochemical silver amplification technique autometallography (AMG), was
used to trace bismuth in the testis of Wistar rats injected intraperitoneally
with bismuth subnitrate. In the seminiferous tubules, bismuth was located in
lysosomes of Sertoli cells closely associated with heads of spermatids in the
late stages of the spermatogenesis, i.e. shortly before the release of Step 19
spermatids in Stage XIII. No bismuth-specific AMG silver grains were detected in
the spermatogenic cell line. However, tails of free sperm cells located in the
tubular lumen showed autometallographic grains in close contact to the nine outer
microtubule doublets in the axonema. Leydig cells concentrated huge amounts of
AMG-bismuth in their lysosomes. Furthermore, parallel exposure to selenium
significantly increased the amount of histochemically traceable bismuth in the
rat testis.
PMID- 10689205
TI - Dr. Brent and scientific debate.
PMID- 10689206
TI - Safe drinking water: An attainable goal, key to health and development, appears
farther away.
PMID- 10689207
TI - Limited effectiveness of home drinking water purification efforts in Karachi,
Pakistan.
AB - OBJECTIVE: In many developing-country urban areas, municipally supplied water is
not microbiologically safe. This study evaluated drinking water quality and
effect of home water purification efforts in Karachi, Pakistan. METHODS: Members
of 300 households, including 100 households who used the Aga Khan University
Hospital Laboratory and 200 of their neighbors were interviewed. In 293
consenting households, structured observations were performed and drinking water
was analyzed for the presence of coliforms, using the multiple tube fermentation
technique. RESULTS: Although 193 of the 293 households (66%) reported using some
method to purify their drinking water, including 169 (58%) who boiled their
water, only 48 (16%) of the drinking water samples were free of coliforms.
Although a combination of boiling and filtering was the most effective method of
purification, only 38% of samples that had been boiled and filtered were free of
coliforms. CONCLUSIONS: Further refinements and evaluations of home-based efforts
to purify and store water are needed.
PMID- 10689208
TI - Epidemic cholera in Guinea-Bissau: the challenge of preventing deaths in rural
West Africa.
AB - OBJECTIVES: An epidemiologic investigation was conducted to identify factors
associated with cholera mortality in a rural African setting and interventions
likely to prevent deaths in future epidemics. METHODS: The authors reviewed
surveillance data from rural Biombo, Guinea-Bissau, interviewed family members of
persons who died of cholera, and conducted a case-control study in the catchment
area of a health center with a high case:fatality ratio (CFR). RESULTS: Forty
three deaths occurred among the 1169 persons who reported to health centers with
cholera during the epidemic (CFR = 3.7%). Delayed rehydration and over-hydration
probably contributed to 10 of these deaths. An additional 19 cholera deaths
occurred outside health centers. In the case-control study, persons with cholera
who died were 5.4 times (95% CI = 1.0-53.4) more likely to be in poor health or
intoxicated at illness onset than persons with cholera who survived. Fatal cases
were 6.0 times (95% CI = 1.1-60.8) more likely to not attend the health center
than survivors. CONCLUSIONS: The low overall CFR in Biombo, compared to CFRs
reported during other epidemics in sub-Saharan Africa, suggests that medical care
provided at rudimentary rural health centers prevented numerous deaths.
Additional deaths may be prevented by strengthening the infrastructure of health
services in the rural areas and by enhanced public education regarding the need
for persons with cholera to promptly seek medical care.
PMID- 10689209
TI - Introducing a novel model to estimate national and global measles disease burden.
AB - OBJECTIVES: In discussions of expanded measles control, elimination, and possible
eradication, better estimates of disease burden are increasingly important to
target vaccination control measures. Because global surveillance for measles is
inadequate, a model to quantify country-specific estimates of measles disease
burden was formulated to help policy-makers consider control options. METHODS:
Country-specific demographics, developmental status, historic vaccine coverage
rates, and age-specific vaccine efficacy and attack rates were used to determine
the number of measles cases and deaths for 5-year periods. RESULTS: The model
estimates an annual global incidence of 32 million measles-susceptible persons (
approximately 25% of the global birth cohort), resulting in 28 million cases and
691 thousand deaths. Eighty-four percent (578,000) of the global deaths occur in
the World Health Organization African and Southeast Asian regions. Twenty
countries account for 82% of deaths attributable to measles. In nine countries,
over 2% of the birth-cohort are estimated to die from measles. CONCLUSIONS: This
methodology quantifies country- and age-specific measles disease burden and
establishes regional and global disease patterns, allowing aggregations by income
groups and regions, which aids policy formulation. The data may be continuously
updated, based on dynamic changes in vaccine coverage rates and the incorporation
of national vaccination campaigns.
PMID- 10689210
TI - Ceftazidime-resistant Klebsiella pneumoniae bloodstream infection in children
with febrile neutropenia.
AB - OBJECTIVES: To evaluate prevalence of ceftazidime-resistant Klebsiella pneumoniae
(CRKP) in the pediatric oncology unit of University Hospital, Kuala, Lumpur, and
to identify differences between febrile neutropenic pediatric patients with CRKP
and ceftazidime-sensitive K. pneumoniae (CSKP) bacteremia. MATERIALS AND METHODS:
Febrile neutropenic patients treated between January 1996 and December 1997 at
the pediatric oncology unit of University Hospital, Kuala Lumpur, were
prospectively studied. Empirical antibiotic therapy consisted of ceftazidime and
amikacin. Those who developed K. pneumoniae bacteremia were identified, and
clinical features analyzed. Ceftazidime-resistance was documented via disk
diffusion testing. Production of extended-spectrum beta-lactamase (ESBL) was
inferred on the basis of synergy between ceftazidime and amoxicillin-clavulanic
acid. The different features between the two groups and variables associated with
the development of CRKP bacteremia were analyzed using chi-square and t-tests and
calculation of odds ratios. A multivariate analysis was used to identify
independent factors for CRKP development. RESULTS: Ceftazidime-resistance was
seen in 51.6% of all K. pneumoniae isolates, and all these isolates were inferred
to be ESBL producers. All isolates were sensitive to imipenem. Susceptibility to
gentamicin was 90.5%. The mean continuous hospital stay prior to the detection of
bacteremia was 13.7 days overall, but significantly longer in the CRKP group
(21.9 d) compared to the CSKP group (4.3 d) (P = 0.003). Children with CRKP were
more likely to have received antibiotics in the 2 weeks prior to detection of
bacteremia (87.5% of cases) than the CSKP group (20.0% of cases) (P = 0.0008).
Sepsis-related mortality was higher in those with CRKP (50.0%) than in the CSKP
group (13.3%) (P = 0.02). Patients who did not receive CRKP-directed antibiotics
within 48 hours of admission were more likely to have a fatal outcome than those
who did (P = 0.009). Logistic regression analysis identified use of third
generation cephalosporins 2 weeks prior to presentation and a hospital stay of 2
weeks or more as independent risk factors for development of CRKP. CONCLUSIONS:
More than half of total K. pneumoniae isolated from blood cultures in the unit
were ceftazidime-resistant. Children with febrile neutropenia with prolonged
hospital stay and recent prior antibiotic exposure are at high risk of developing
CRKP bacteremia. Mortality was significantly higher in this group. Early
commencement of appropriate antibiotics (e.g., imipenem with or without
gentamicin), according to susceptibility study results, may be beneficial in such
circumstances.
PMID- 10689211
TI - International study comparing cefdinir and cefuroxime axetil in the treatment of
patients with acute exacerbation of chronic bronchitis.
AB - OBJECTIVES: To assess the efficacy and tolerability of three antibiotic regimens
in patients with acute exacerbation of chronic bronchitis. METHODS: In this
double-blind, randomized, multicentered, parallel-group study, patients received
once-daily cefdinir 600 mg, twice-daily cefdinir 300 mg, or twice-daily
cefuroxime axetil 250 mg for 10 days. Primary efficacy measures were
microbiologic eradication rate, by pathogen and by patient, and clinical response
rate, by patient. RESULTS: Of 1045 patients, 589 were evaluable for efficacy. At
baseline, most patients had moderate or severe cough and sputum production as
well as rhonchi, wheezing, and dyspnea. The microbiologic eradication rates by
pathogen were 90% with once-daily cefdinir, 85% with twice-daily cefdinir, and
88% with twice-daily cefuroxime. The corresponding values for microbiologic
eradication rate by patient were 90% (once-daily cefdinir), 85% (twice-daily
cefdinir), and 86% (twice-daily cefuroxime). The respective clinical response
rates by patient were 81%, 74%, and 80%. There were no significant differences in
the incidence of drug-related adverse events or discontinuations due to adverse
events. Diarrhea was the most frequent complaint. CONCLUSIONS: The results
indicate that the efficacy and tolerability of cefdinir, once or twice daily, and
cefuroxime were comparable with no significant differences between the regimens
used.
PMID- 10689212
TI - Prevalence of anti-hepatitis A antibodies in an urban middle class area of
Argentina: some associated factors.
AB - OBJECTIVE: This study evaluated the seroprevalence of hepatitis A virus (HAV)
antibodies in 360 middle-class subjects from Buenos Aires City and its outskirts.
METHODS: The study population included 360 individuals between 10 and 89 years of
age, from the socioeconomic middle class in Buenos Aires City and some suburban
areas of Buenos Aires province. Antibodies to hepatitis A virus were determined
by enzyme immunoassay test kits. RESULTS: The overall prevalence of HAV
antibodies was 42.2%. The highest percentage of seronegativity was found in the
subgroup of younger people without a history of symptomatic hepatitis and living
in houses with more than one bathroom (86.9%). In the subgroup aged 21 to 60
years, the highest rates of seronegativity were found in individuals with higher
level of education living in houses with tap water (66.6%). In both groups,
seronegativity may be correlated with a higher socioeconomic status. CONCLUSIONS:
In the middle-class community studied, more than 50% of people under 30 years of
age were unprotected against HAV. Thus, the use of a vaccine against hepatitis A
has to be considered for the prevention of symptomatic hepatitis, especially in
adults at risk of infection, such as those who travel to areas with poor
sanitation, taking into consideration that the severity of the disease increases
with age.
PMID- 10689213
TI - Role of tumor necrosis factor-alpha in the differential diagnosis of
parapneumonic effusion.
AB - OBJECTIVE: This study was undertaken to investigate the role of tumor necrosis
factor-a (TNF-a) in discriminating between uncomplicated parapneumonic effusion
(UCPPE) and complicated parapneumonic effusion (CPPE). METHOD: Using a
commercially available high sensitivity enzyme-linked immunosorbent assay (ELISA)
kit, concentrations of TNF were measured in the serum (TNFs) and pleural fluid
(TNFpf) of 21 patients with parapneumonic effusion (PPE), 13 patients with UCPPE,
and 8 patients with nonempyemic CPPE. RESULTS: No significant difference in
values of TNF concentration was found between the group with UCPPE and that with
CPPE (P > 0.05). Concentration levels of TNFpf were significantly higher in the
group with CPPE than in that with UCPPE (P = 0.0008). Levels of TNF in pleural
fluid were significantly higher than in serum in both groups (P < 0.001). The
ratio of TNF in pleural fluid to that in serum (TNFr) was significantly higher in
the CPPE group than in the UCPPE group (P = 0.0002). At an optimal cutoff point
of 10.7 pg/mL for TNFpf, the sensitivity was 87.5%, specificity was 92.3%,
positive predictive value was 87.5%, negative predictive value was 93.3%, and
total accuracy was 90.5% (P < 0.001). At an optimal cutoff point of 3.0 for TNFr,
all values were 100% (P < 0.00001). CONCLUSIONS: The results of this study
indicate that TNFpf, and particularly TNFr, may be helpful in discriminating
between UCPPE and CPPE. However, further studies are needed in a larger
population to confirm these findings.
PMID- 10689214
TI - Evaluation of a supplemental assay for the diagnosis of hepatitis C virus
infections.
AB - OBJECTIVES: A supplemental test was evaluated for hepatitis C virus (HCV).
METHODS: One hundred forty-six sera that were inconclusive or discrepant in two
screening tests for HCV infection were evaluated using a supplemental test,
MATRIX-HCV2 (Abbott Laboratories, Chicago, IL, USA). Results of the supplemental
test were compared to the detection of HCV RNA by a nested polymerase chain
reaction after a step of reverse transcription (RT-PCR). RESULTS: Thirty-nine RNA
containing sera (positive with RT-PCR) of 40 (97%) reacted with at least one
antigen in the supplemental test. Reactivity with one to three antigens also was
observed with 77 PCR-negative sera (66%). Twenty-nine sera were found negative
with both techniques. CONCLUSIONS: Despite clear results and good sensitivity,
the MATRIX-HCV2 assay was poorly predictive of viremia in patients with
indeterminate results in initial screening assays.
PMID- 10689215
TI - Generation of reactive oxygen species and formation and membrane lipid peroxides
in cells infected with Chlamydia trachomatis.
AB - OBJECTIVES: Chlamydiae are obligate intracellular pathogens that cause many
diseases for which the pathogenic mechanisms are largely unknown. Because
reactive oxygen species (ROS) have been implicated in pathogenesis of many viral
and bacterial infections, the authors assessed the release of ROS in selected
host cells (monocytes, Sup-T1 cells, and Hep-2 cells) infected with Chlamydia
trachomatis. METHODS: Infected cell cultures demonstrated a dramatic depletion of
uric acid from culture media that was not seen in uninfected cultures. Reactive
oxygen species generated in infected cultures were associated with the formation
of lipid peroxides in host cell membrane. RESULTS: There was a significant
increase in lipid peroxide levels in infected cells compared to uninfected
controls. Ascorbic acid treatment of infected cell cultures reduced the formation
of membrane lipid peroxides. CONCLUSIONS: These results suggest that ROS produced
during chlamydial replication cause membrane lipid peroxidation. The role of ROS
induced membrane damage in chlamydial pathogenesis is discussed.
PMID- 10689216
TI - Cutaneous gnathostomiasis in a woman from Bangladesh.
AB - A woman from Bangladesh who had lived in Germany for more than 2 years presented
with migratory, painful swellings on her left hand and arm of 5 months duration.
Laboratory examinations yielded a marked eosinophilia and a grossly elevated IgE
level in combination with an inflammatory reaction restricted to the subcutaneous
tissues. A preliminary diagnosis of gnathostomiasis was established and confirmed
by a positive gnathostoma serology by enzyme immunoassay (EIA). Treatment was
initiated with albendazole, leading to the outward migration of a larva and
complete resolution of clinical disease. Currently, there is no definitive
therapy that has been proved to be both safe and highly effective. A wide range
of potential agents has been used in clinical studies, but only albendazole has
proved to be reliably effective to date, stimulating the outward migration of
larvae in a proportion of cases of cutaneous disease, as observed in the present
case.
PMID- 10689217
TI - Brucellosis in a mother and her young infant: probable transmission by breast
milk.
AB - Brucellosis, although primarily a zoonotic infection, is also a threat for human
health. Infection can be transmitted to humans through direct contact with
infected animals, products of conception, or animal discharges, and through
consumption of potentially infected milk, milk products, or meat. Human-to-human
transmission is rare. There have been case reports of transmission via blood
transfusion and bone marrow transplantation from infected donors. Sexual
intercourse is a possible means of transmission. Neonatal infection can be
acquired transplacentally or during delivery. This report describes a mother with
brucellosis who probably transmitted the infection to her 3-month-old baby by
breast milk.
PMID- 10689218
TI - Isolated primary hepatic lymphoma in a patient with acquired immunodeficiency
syndrome.
AB - Non-Hodgkin lymphoma (NHL) of the B-cell type is the second most common neoplasm
in patients with human immunodeficiency virus (HIV) infection after Kaposi
sarcoma (KS). The majority of cases of NHL in patients with acquired
immunodeficiency syndrome (AIDS) involve extranodal sites; most frequently the
gastrointestinal tract (GIT) and the central nervous system (CNS). Hepatic NHL in
patients with AIDS was first described by Reichert et al in 1983 in an autopsy
series. It usually presents with multiple large hepatic masses and involvement of
other abdominal organs or lymph nodes. The authors present a case of primary
hepatic NHL in a patient with AIDS, presenting with innumerable small
intrahepatic masses without the involvement of any other organs.
PMID- 10689219
TI - Editorial.
AB - The cosmopolitan nature of current travel practices, as well as significant
immigration from endemic areas, has led to increases in the incidence of leprosy.
The classic presentation of leprosy usually appears as the indeterminate form,
demonstrates hypopigmented macules with a loss of sensation. However, the
manifestations can sometimes be quite protean. Sadeghi et al. review the
rheumatic manifestations of leprosy with an illustrating case presenting with
arthritis. Rheumatic symptoms are common in leprosy patients and may be the
presenting manifestations and should be considered in patients with persistent
rash and unusual arthritis who have a history of exposure to endemic areas.
Significant interest has developed over the past decade in inhibiting cutaneous
carcinogenesis with retinoic acid. This has been used as an effective therapy in
certain genetically predisposed individuals, including individuals with a DNA
repair defect in xeroderma pigmentosa. The molecular mechanisms of retinoids
ability to inhibit ultraviolet light induced carcinogenesis have not been
determined. Li and co-workers have examined the effect of retinoic acid on
ultraviolet light induced programmed cell death (apotosis) as well as expression
of the tumour suppressor gene P53. Their studies suggest that retinoic acid does
not work on the initiation stages of the cancer development, but may work in the
promotion and progression stage. Of more immediate clinical importance, in the
Point-Counterpoint section, we have two insightful articles on how physician
reimbursement affects patient care. As North American health care continues to
evolve, there is constant debate on what model system works best for the ultimate
benefit of our patients. Physicians, politicians, and administrators are
constantly comparing the United States health care delivery to that of Canada.
While no one can accurately predict the future developments in these areas, I
think Dr. McElgunn sums the concerns that indeed are applicable on both sides of
the border: ".socialized medical system has been of great benefit to patients but
the ability of its physicians to continue to carry the system is at or near the
breaking point. The ramifications of the issues of access and quality of care are
harbingers of a system in turmoil." While these concerns must be dealt with,
strong physician input is vital to continuing the effective evolution of our
health care system. A vital part of our health care delivery is the increasing
use of diagnostic tests. Key treatment decisions and interventions are based on
the interpretation of these tests. However, most tests are "imperfect
instruments." The article by Binder and Dreiseitl concisely reviews sensitivity,
specificity, prevalence, predictive values, and likelihood ratios in a highly
informative manner with significant examples. This paper provides a reference
with which all physicians should be familiar. Traditionally, Western medicine has
focused on a model of disease whereby pathology was regarded as well defined
alteration in normal physiology that should respond to appropriate pharmaceutical
or surgical interventions. However, in recent years patient focused medicine has
become an important aspect of our practices. The concept of health related
quality of life has represented an important advance in dealing with these
concerns in our treatment of disease. Drs. Price and Harding examine the concept
of health related quality of life using the example of a diabetic foot ulcer
complications. These types of measures are important to understand, not only in
the context of this disease but in the context of any chronic dermatologic
condition.
PMID- 10689220
TI - Effect of retinoic acid on apoptosis and DNA repair in human keratinocytes after
UVB irradiation.
AB - BACKGROUND: Skin cancer is extremely common. Epidemiological studies indicated
that ultraviolet radiation (UV) is the primary cause for skin cancers, and that
retinoic acid (RA) is able to inhibit this UV-induced skin carcinogenesis;
however, the molecular mechanism of the anti-UV action of RA is unclear.
OBJECTIVE: The purpose of this study is to investigate if RA enhances the removal
of UV-induced DNA damage. METHODS: The effect of RA on UV-induced apoptosis and
DNA repair was investigated by ELISA apoptosis assay and CAT assay. RESULTS: Both
all-trans-RA and 9-cis-RA did not promote UV-induced apoptosis nor the repair of
UV-damaged DNA in human keratinocytes. Furthermore, RA did not induce the
expression of p53. CONCLUSION: The inhibition of RA on skin carcinogenesis is not
due to enhanced removal of UV-damaged DNA. Therefore, RA does not inhibit skin
cancer development at the initiation stage, but possibly at the promotion and
progression stages.
PMID- 10689221
TI - Open-label study to evaluate the healing rate and safety of the Profore Extra
Four-Layer Bandage System in patients with venous leg ulceration.
AB - BACKGROUND: Venous ulcers are increasing in prevalence, especially since these
are observed more frequently in the elderly, and the number of individuals in
this age group is becoming a larger portion of the population. OBJECTIVE: To
determine the healing rate and safety of the Profore Extra Four-Layer Bandage
System in the management of venous leg ulcers. METHODS: In an open-label study,
patients aged 18 years or older with venous leg ulcers were treated with a high
compression four-layer bandage system in which a hydrocellular dressing was
placed in contact with the wound. The combination is designated the "Profore
Extra Four-Layer Bandage System." Follow-up visits took place weekly unless there
was heavy exudation from the ulcer or if there was marked edema of the leg at the
start of the study requiring reapplication of the bandage system. RESULTS:
Fifteen patients were entered into the study (men 8, women 7, mean age 66 years,
mean duration of ulcers 1.3 years). Thirteen of the 15 patients completed the
study, with two withdrawals. In one patient who withdrew, the ulcer became
infected and required treatment with antibiotics. The other termination from the
study occurred for reasons unrelated to treatment. The ulcer in this patient
healed in 7 weeks. Ten of the 13 patients (77%) who completed the study, and 10
(67%) of 15, who had enrolled experienced complete (100%) healing. Healing of >
80% of the ulcers occurred in 11 of 13 patients (85%) who completed the study and
in 12 (80%) of 15 enrolled patients. No patient experienced a study-related
adverse event. One patient developed contact dermatitis and was later found to
have stasis dermatitis. It is unclear whether the initial event was contact or
stasis dermatitis. CONCLUSION: In this open-label study, a high compression
system, using the Profore Extra Four-Layer Bandage with a hydrocellular dressing
in contact with the wound, was found to be effective and safe for the treatment
of venous leg ulcers.
PMID- 10689222
TI - Perforating disorders: summary notes.
AB - The intention of the Summary Notes section is to provide the practitioner and
trainee with a current, concise reference source to dermatologic diseases and to
serve as a form of Continuing Medical Education. Each installment will deal with
a specific disease. When included, the pretest questions indicate some of the
areas to be covered and will challenge your present knowledge of the material
before reading further. The self-assessment post-test questions appear on page
18; the answers are on page 25.
PMID- 10689223
TI - The interpretation of test results.
AB - BACKGROUND: Dermatologists need to interpret an increasing number of research
studies and diagnostic tests. Understanding the techniques for interpreting test
results and making decisions based upon those tests represent important tools for
decision making for both clinicians and researchers. OBJECTIVE: This article
focuses briefly on the key parameters of diagnostic tests: sensitivity,
specificity, prevalence, predictive values, likelihood ratios, and the concept of
receiver-operating-characteristic (ROC) curves. A simple example is presented in
a step-by-step manner. CONCLUSION: The principles of interpreting test results
are easy to learn and applicable in daily clinical routine. Therefore,
dermatologists should be familiar with the concepts outlined in this paper.
PMID- 10689224
TI - Delay in diagnosis: indeterminate leprosy presenting with rheumatic
manifestations.
AB - BACKGROUND: Rheumatic complications are common in leprosy (Hansen's disease) and
can be the primary complaint delaying accurate diagnosis. OBJECTIVE: Such a case
is reported here: a 61-year-old woman with indeterminate leprosy presented with
symmetric arthritis and purpura. Despite biopsy and evaluation by several
physicians, leprosy was not suspected. After 2 years of progressive symptoms, a
second biopsy revealed lepromatous leprosy. CONCLUSION: In this case, lack of
clinical suspicion and unfamiliarity with the histology of indeterminate leprosy
delayed diagnosis and treatment. Leprosy should be considered in the differential
diagnosis of patients presenting with unusual rheumatic and persistent cutaneous
manifestations.
PMID- 10689225
TI - Lichen planopilaris-like changes arising within an epidermal nevus: does this
case suggest clues to the etiology of lichen planopilaris?
AB - BACKGROUND: Lichen planopilaris shows a perifollicular lymphocytic infiltrate at
the level of infundibulum and the isthmus of the hair bulge resulting in necrotic
changes within keratinocytes and eventually hair loss. OBJECTIVE: We present a 14
year-old black male with a history of a raised epidermal lesion on the scalp that
was present at birth. Over the past few years, the patient developed gradual hair
loss and increased verrucous changes of the skin within the original lesion.
Histologic sections of the area showed features consistent with an epidermal
nevus peripherally, with a central area showing some features characteristic of
those seen in lichen planopilaris. In addition, there was marked hyperkeratosis
with increased yeast and bacteria within the follicles. CONCLUSIONS: Initiating
factors in lichen planopilaris are not well defined. Overgrowth of microorganisms
with hyperkeratosis results in factors that disrupt the immune privilege of the
hair follicle, leading to an immunologic reaction that is limited to the follicle
and spares surrounding eccrine structures. This case suggests possible mechanisms
involved in the induction of lichen planopilaris.
PMID- 10689226
TI - Treatment of vascular lesions in pigmented skin with the pulsed dye laser.
AB - BACKGROUND: Vascular lesions occurring in African-American patients are often not
treated because of the risk of local side effects. OBJECTIVE: The study was to
determine the efficacy of the flashlamp-pumped dye (FLPD) laser in the treatment
of vascular malformations in African-American patients. METHODS: All lesions in
three patients were treated with the FLPD laser using a 585 nm wavelength, 5 mm
spot size, 450 pulse width, and fluences ranging from 6.5 to 8.5j per cm2.
CONCLUSION: The FLPD was effective in treating vascular malformations. Transient
changes in colour and skin texture occurred at the treated sites.
PMID- 10689227
TI - Wrinkling due to mid-dermal elastolysis: two cases and literature review.
AB - BACKGROUND: Mid-dermal elastolysis is an acquired disorder of elastic tissue
clinically characterized by diffuse fine wrinkling, most often of the trunk and
arms. Histologically, a clear band of elastolysis is present in the mid-dermis.
OBJECTIVE: Although examples of diffuse elastolysis are well known, only a small
number of patients with mid-dermal elastolysis have been reported to date. We
present two patients with clinical and histological evidence of mid-dermal
elastolysis, review the literature, and summarize the salient features of some
common disorders of elastic tissue. METHODS: The first patient presented with
fine wrinkles and papules over the upper arms, upper chest, and axillae, and
demonstrated increased laxity of the eyelids. The second patient had striking
wrinkles extending in a band-like pattern on her arms, upper chest, back, and
abdomen. Neither one of our patients had a previous history of skin inflammation,
urticaria, or any other underlying diseases related to their skin changes. Skin
biopsies were taken from lesional and perilesional skin of both patients, and
were stained with hematoxylin and eosin, and with elastic tissue stain. In
addition, a tissue sample from Patient 1 was fixed for electron-microscopy.
RESULTS: Hematoxylin and eosin stains did not demonstrate specific changes or
diagnostic patterns. However, elastic tissue stains revealed a band-like loss of
elastic tissue in the mid-dermis. Elastic tissue in the remaining superficial and
deep dermis stained normally. Electron-microscopy was consistent with these
findings and revealed significant loss of elastic tissue limited to the mid
dermis. CONCLUSION: We have presented two cases of mid-dermal elastolysis and
reviewed the literature. To date, the pathophysiology of mid-dermal elastolysis
had not been elucidated and no definitive therapy exists.
PMID- 10689228
TI - The impact of foot complications on health-related quality of life in patients
with diabetes.
AB - BACKGROUND: The concept of health-related quality of life (HRQoL) has been the
focus of much debate in recent years. However, within diabetes the focus has
centred on the behavioural adaptation to a chronic disease state. The impact of
foot complications is witnessed regularly in the clinical setting; amputation in
this group is usually preceded by ulceration and a worsening cycle of foot
problems. OBJECTIVE: This review sets out to investigate the literature on foot
complications in those with diabetes, to assess the cost to the individual in
terms of impact on everyday living. CONCLUSION: The literature on the specific
impact of foot complications is limited, but indicates a situation in which those
with diabetic foot ulceration may have an even poorer HRQoL than those who have
experienced an amputation related to diabetes. In order to assess the full impact
of new treatments or therapeutic interventions, it is vital that further research
is conducted in this area.
PMID- 10689229
TI - Sporotrichosis infection on mines of the Witwatersrand.
AB - BACKGROUND: Our knowledge of skin disease is often based on fortuitous situations
that have provided opportunities for observation and study of the disease. One of
these diseases is sporotrichosis. OBJECTIVE: This article examines a symposium
published in 1947 by the Transvaal Chamber of Mines in South Africa. It reviews
the approach taken in the investigation of a large outbreak of sporotrichosis in
the mine workers. CONCLUSION: The investigation of this outbreak has contributed
significantly to our present day knowledge of sporotrichosis, the causative
organism, its mode of spread, and its clinical features. It is also a striking
example of meticulous scientific research and observation.
PMID- 10689230
TI - International regulations for automobile driving and epilepsy.
AB - BACKGROUND: Many patients with epilepsy travel abroad and drive automobiles with
the assumption that policies, rules, and regulations on epilepsy and driving are
similar to those of their home countries. This paper investigates the driving
restrictions and other pertinent information on this issue in foreign countries.
METHODS: A questionnaire was sent to 231 neurologists (chosen from American
neurological and epilepsy societies) from 84 countries and to 230 official
(embassies and consulates) representatives of 134 countries asking for the local
rules and regulations and their comments on driving and epilepsy. RESULTS: One
hundred and sixty-six responses were received from 96 of 134 (72%) countries. One
hundred and six neurologists (of 231 queried [46%]) responded. In 16 countries,
persons with epilepsy are not permitted to drive. In the remaining countries,
these patients must have a seizure-free period of 6 to 36 months. This period
varies according to the type of seizure. In five countries, physicians must
report the names of these patients to their local authorities. In many countries,
the rules and regulations are being reevaluated and changed. CONCLUSIONS:
Patients with epilepsy who plan to drive overseas are advised to contact local
embassies and consulates, well before their trips (and keep records of the
communications) to obtain the latest information on the rules and regulations
governing the driving of automobiles in those countries.
PMID- 10689231
TI - Neuropsychiatric problems in 2,500 long-term young travelers to the tropics.
AB - BACKGROUND: The prevalence and features of travel associated neuropsychiatric
problems (NPP) and their relation to previous psychological consultations,
antimalarials and recreational drug use have not been adequately studied.
METHODS: A two-phase postal and telephone survey has been conducted among 2,500
young travelers to tropical countries. We measured the rate and duration of NPP,
characterized their features, and their association with previous psychological
profiles, itinerary, type of travel, consumption of recreational drugs, and
malaria prophylaxis. RESULTS: First phase: Out of 1,340 respondents, 151 (11.3%)
indicated that they had NPP during travel, in contrast with 2.3% who needed
psychological consultation before travel (p<.001). Second phase: 117 of 151
responded to the study questionnaire. The mean age of the respondents was 24.4
years, 54.7% were female, and the mean stay abroad was 5.3 months. The most
common NPP were sleeping disturbances (52.1%), fatigue (48.7%) and dizziness
(39.3%). Thirty-three travelers (2.5%) had severe symptoms, and 16 (1.2%) had
symptoms lasting more than 2 months. Seven travelers had pure or mixed depressive
symptoms. Consumption of recreational drugs was admitted by 22.2%. Mefloquine was
used significantly more often by those who suffered NPP, than by the entire
cohort (98.2% vs. 70.7%; p<.001). CONCLUSIONS: Long-term travel to the tropics
was associated, in this cohort, with a considerable rate of neuropsychiatric
symptoms. The majority of the responding travelers were females, used mefloquine
as prophylaxis, and at least one fifth used recreational drugs.
PMID- 10689232
TI - Survey of rabies preexposure and postexposure prophylaxis among missionary
personnel stationed outside the United States.
AB - BACKGROUND: Of the 36 cases of human rabies that have occurred in the United
States since 1980, 12 (33%) were presumed to have been acquired abroad. In the
United States, it is recommended that international travelers likely to come in
contact with animals in canine rabies-enzootic areas that lack immediate access
to appropriate medical care, including vaccine and rabies immune globulin, should
be considered for preexposure prophylaxis. In 1992, the death of an American
missionary who had contracted rabies while stationed in Bangladesh highlighted
this high-risk group. METHODS: To assess their knowledge of rabies risk, rabies
exposures, and compliance with preventive recommendations, we asked 695
missionaries and their family members to complete questionnaires about their time
stationed abroad. RESULTS: Of the 293 respondents stationed in countries where
rabies is endemic, 37% reported prior knowledge of the presence of rabies in
their country of service. Only 28% of the personnel stationed in rabies-endemic
countries received preexposure prophylaxis. Having preexposure prophylaxis
specifically recommended increased the likelihood of actually receiving it (O.R.
15.6, 95%CI 7.4 - 34.9). There were 38 reported exposures (dogs = 66%, another
human = 20%), proven or presumed to be rabid. Three of the people exposed
received rabies immune globulin and vaccine; 11 received vaccine alone; 8
received only basic first aid, and 16 received no treatment. CONCLUSIONS:
Although American missionaries stationed abroad are at an increased risk for
exposure to rabies, compliance with established preventive measures was low.
Prior to being stationed abroad, an educational rabies-prevention briefing,
including encouragement to receive preexposure prophylaxis, could be an effective
intervention for missionaries to decrease their risk of rabies.
PMID- 10689233
TI - Etiology of travelers' diarrhea on a Caribbean island.
AB - BACKGROUND: Between December 6, 1994 and March 10, 1996, a study of the etiology
of diarrhea was carried out among 332 travelers to five all-inclusive hotels in
Negril, Jamaica. METHODS: Stool specimens were collected and sent to Montego Bay
for laboratory analysis. Escherichia coli strains isolated at the Jamaican
laboratory were sent to Houston for toxin testing. RESULTS: A recognized
enteropathogen was found in 118 of the 332 (35.5%) cases. Enterotoxigenic E. coli
(ETEC) were the most commonly identified pathogen (87/332; 26.2%) followed by
Salmonella (4.2%) and Shigella (4.2%). Clustering of etiologically defined cases
was studied at each hotel. A cluster was defined as 2 or more cases with the same
pathogen identified in the same hotel within 7 days. In the 3 hotels with the
highest number of cases of diarrhea, enteropathogens were part of a cluster in 65
of 99 cases (65.7%) of diarrhea of which an etiologic agent was identified. In
the other 2 hotels, only 4 of 20 cases (20%) occurred in clusters. CONCLUSIONS: A
total of 25 clusters of travelers' diarrhea cases was detected at the five hotels
during the study period. Seventeen of 25 (68%) ETEC isolations occurred as part
of a clustering of diarrhea cases. The largest outbreak of pathogen-identified
diarrhea consisted of 7 cases of ETEC producing both heat-stable and heat-labile
enterotoxins. In the Jamaican hotels with all inclusive meal packages most
diarrhea cases occurred as small clusters, presumably as the result of foodborne
outbreaks.
PMID- 10689234
TI - Typhoid fever in group travelers: opportunity for studying vaccine efficacy.
AB - BACKGROUND: Typhoid fever (TF) is a rare disease among travelers to endemic
areas, and little is known about its travel-related epidemiology. In addition,
efficacy data on TF vaccines in travelers is scanty. During 3 months of 1994/95,
six cases of TF were reported in The Netherlands among participants of four
package tours to Indonesia provided by the same operator. The present study was
designed to describe the epidemiology of TF in these groups, and to assess
whether travel groups can be used for studying the efficacy of TF vaccines in
travelers. METHOD: Questionnaire-based historical cohort study of participants of
4 groups that stayed in the same hotels along their tours (n=156). TF was defined
as blood culture-confirmed Salmonella typhi infection. Submitted isolates were
typed by antigen and phage typing. Immunization status was considered documented
if ascertained by written records. RESULTS: Among 110 participants (71%), six
cases of TF were identified (group specific attack rate AR 5.4%), three of which
were from one travel group (AR 12.0%). There were no significant differences by
age or sex. Three submitted S. typhi isolates showed three different types, two
of which were in the same group. Eighty-three percent of respondents reported
documented TF vaccination in the preceding 3 years. All cases occurred in
recipients of the oral Ty21a vaccine (AR 10.2%, 95% CI 3.8-20.8%), but
differences with nonvaccinees and recipients of the heat-inactivated whole cell
or Vi-antigen polysaccharide vaccines were not significant. CONCLUSIONS: Although
TF is rare in travelers, infections with different strains of S. typhi can occur
in one travel group. Travel groups offer an opportunity for retrospective
assessment of vaccine efficacy, provided that equal chance of exposure is largely
guaranteed; case ascertainment is maximally specific and similar in the vaccine
groups; vaccine status is ascertained accurately; and prior immunity by previous
exposures to and use of antibiotics effective against the infection are excluded
from, or controlled for in, the analysis.
PMID- 10689235
TI - Experience of corporate medical assistance clinics during the Centennial Olympic
Games, Atlanta, 1996.
AB - The health of travelers returning home from developing countries has received
increased attention in recent years. Much of this attention has centered on
immunizations, malaria chemoprophylaxis and treatment of traveler's diarrhea. In
contrast, there are very few data on the health problems of international
travelers to developed countries such as the United States. We studied the
experience of two corporate medical assistance clinics established for both
national and international travelers to Atlanta, Georgia during the Centennial
Summer Olympic Games in 1996.
PMID- 10689237
TI - Female genital schistosomiasis.
AB - Schistosoma haemtobium infection in travelers from endemic areas is usually
asymptomatic, or presents with hematuria. Uncommon manifestations include
neurological syndromes, genital dysaesthesias and watery or blood stained semen.
This organism also causes disease within all structures of the female genital
tract because of communications between pelvic venous complexes, and can occur
long after return home. Schistosomiasis may not be suspected, resulting in delays
in diagnosis and treatment. We present two cases which illustrate the diverse
nature of this condition.
PMID- 10689236
TI - Double-blind, randomized, placebo controlled pilot study evaluating efficacy and
reactogenicity of an oral ETEC B-subunit-inactivated whole cell vaccine against
travelers' diarrhea (preliminary report).
AB - Diarrhea caused by enterotoxigenic E.coli (ETEC) is an important health problem
in developing countries and in travelers to these areas. In previous trials
formulations of ETEC vaccines containing the B-subunit of cholera toxin, which is
antigenically similar to the heat labile enterotoxin of ETEC, and the most
prevalent colonization factor antigens of ETEC, were shown to stimulate relevant
mucosal immune responses in volunteers from Sweden and Egypt.
PMID- 10689238
TI - Tropical sprue after travel to Tanzania.
AB - Tropical sprue (TS) is a diagnosis to consider in travelers with prolonged
diarrhea and a malabsorption syndrome after return from tropical countries,
particularly India and Southeast Asia. TS is an unusual condition in tropical
Africa. Textbooks of tropical medicine indicate a low endemicity in Nigeria and a
limited number of cases in South Africa and Zimbabwe. A Medline search from 1979
to mid 1998 using "Tanzania and tropical sprue" as key words disclosed no hits.
We report herein a case of TS in a European traveler, who lived in Tanzania for 8
months.
PMID- 10689239
TI - Reactive arthritis associated with typhoid vaccination in travelers: report of
two cases with negative HLA-B27.
AB - As international travel to developing countries increases, more people seek
medical advice concerning food and water-borne diseases, including typhoid fever.
Prevention of typhoid fever in high-risk groups (travelers to endemic areas,
laboratory workers and household contacts of typhoid carriers) should rely
primarily on prevention of exposure. However, immunization is an important
adjunct. The decision to immunize against typhoid fever should be individualized,
taking into account the benefits versus the risk of possible adverse reactions.
Cases of reactive arthritis have been associated with the heat-phenol inactivated
'whole cell' parenteral vaccine, but to our knowledge reactive arthritis has not
been previously reported with the oral form (Ty21a). This is a report of HLA-B27
negative reactive arthritis occurring in two travelers after the administration
of oral Ty21a typhoid vaccine.
PMID- 10689240
TI - The Japanese need travel vaccinations.
AB - At a travel clinic in Kathmandu we reviewed the vaccination records from March
1997 to March 1998 for all travelers to developing countries like Nepal, for two
important vaccines, namely, typhoid and hepatitis A. These travelers visited the
clinic for various medical problems. One of the reasons for doing this study was
that in previous years we saw a disproportionate number of Japanese travelers
with hepatitis A, who had not taken the hepatitis A vaccine or immune gamma
globulin for prevention of this illness. We hypothesized, therefore, that one of
the reasons that Japanese patients visiting our clinic had higher rates of
hepatitis A was because they were not vaccinated against this disease. There were
765 tourists for that time period out of which about 10% were Japanese. The rest
were Americans, British, Israelis, Canadians, Australians, Danish and a small
miscellaneous group from other countries.
PMID- 10689241
TI - Safety of iodine based water sterilization for travelers.
AB - The recent report by Khan et al. of an unexpectedly high concentration of free
iodine in water filters, which may have led to the high proportion of abnormal
thyroid function tests in Peace Corps workers, is of concern for travel advisors
when asked to recommend suitable means of water sterilization. Many travelers use
iodine based filters and/or chemicals for purification of water when traveling in
areas with contaminated water supplies and may therefore be at risk of excess
iodine intake. Aside from iodine impregnated resin filtration systems,
tetraglycine hydroperiodide tablets, tincture of iodine 2% and more commonly,
chlorine-based proprietary products are widely used to sterilize water for
drinking, and usually purchased by travelers without advice on how they should be
used. A single tetraglycine hydroperiodide tablet in a liter of water releases 8
mg of iodine in comparison to the 10 mg/liter released from the iodinated resin
pumps described by Khan et al. Although the instructions for using iodine
tincture are imprecise, the normal recommendation is 5 drops per liter of water,
increasing this to 12 drops where Giardia cysts may be present. The lower of the
two doses would yield about 2 mg/liter of free iodine per liter depending on the
pipette used, although, because of the potassium iodide present in the
formulation, a total of 4 mg iodine would be available for absorption.
PMID- 10689242
TI - Intractable nausea, vomiting and diarrhea in a Mexican woman with No recent
travel history.
AB - A 45-year-old Mexican woman with a history of noninsulin dependent diabetes
mellitus (NIDDM), hypertension, and coronary artery disease presented to the
hospital after 2 months of intractable nausea, vomiting and diarrhea-all made
worse by eating and drinking. She reported fever, chills, anorexia and a
documented 50-pound weight loss during this period. She denied the signs and
symptoms of melena, hematochezia, steatorrhea or constipation. She also reported
left leg pain and decreased sensation and strength of her left leg compared to
the right leg. She had been hospitalized 2 weeks prior to admission with the same
symptoms and a diagnosis of viral gastroenteritis. She was also treated for H.
pylori, but subsequent biopsy results were negative by Steiner stain.
PMID- 10689243
TI - Two simultaneous cases of Cyclospora cayatensis enteritis returning from the
Dominican Republic.
AB - According to the "International Passenger Survey," published in 1996 by the
Office of Trading Standards, 534,000 British people traveled to the Caribbean
area (personal communication, ABTA, 1998). The Dominican Republic, the eastern
end of a large Caribbean island, has become in recent years one of the most
popular destinations for UK holidaymakers as well as for travelers from many
other countries. Cyclospora cayatensis has been firmly identified as a cause of
gastroenteritis among international travelers,1 including human immunodeficiency
virus (HIV)-positive individuals,2 but it has not been previously reported in the
literature in British individuals returning from this increasingly popular
vacation destination.
PMID- 10689244
TI - Sea urchin puncture resulting in PIP joint synovial arthritis: case report and
MRI study.
AB - Of the 600 species of sea urchins, approximately 80 may be venomous to humans.
The long spined or black sea urchin, Diadema setosum may cause damage by the
breaking off of its brittle spines after they penetrate the skin. Synovitis
followed by arthritis may be an unusual but apparently not a rare sequel to such
injury, when implantation occurs near a joint. In this case report, osseous
changes were not seen by plain x-rays. Magnetic resonance imaging (MRI) was used
to expose the more salient features of both soft tissue and bone changes of black
sea urchin puncture injury 30 months after penetration. In all likelihood, this
type of injury may be more common than the existing literature at present
suggests. It is believed to be the first reported case in this part of the world
as well as the first MRI study describing this type of joint pathology. Local and
systemic reactions to puncture injuries from sea urchin spines have been
described previously. These may range from mild, local irritation lasting a few
days to granuloma formation, infection and on occasions systemic illness. The sea
urchin spines are composed of calcium carbonate with proteinaceous covering. The
covering tends to cause immune reactions of variable presentation. There are only
a handful of reported cases with sea urchin stings on record, none of them from
the Red Sea. However, this condition is probably more common than is thought and
can present difficulty in diagnosis. In this case report, the inflammation
responded well to heat treatment, mobilization and manipulation of the joint in
its post acute and chronic stages. As some subtle changes in soft tissues and the
changes in bone were not seen either on plain x-rays or ultrasound scan,
gadolinium-enhanced MRI was used to unveil the marked changes in the joint.
PMID- 10689245
TI - A case of dengue from Pune, India.
AB - Dengue is an acute infectious disease, caused by a single stranded ribonucleic
acid (RNA) virus of the family of Flaviviridae, genus Flavivirus, transmitted by
Aedes mosquitos, the most important vectors being Aedes aegypti and Aedes
albopictus. There are four serotypes, DEN-1, DEN-2, DEN-3, DEN-4 that are nearly
human specific. The geographical distribution of dengue is pantropical, except
for Madagascar and some African regions. It is endemo-epidemic in tropical and
subtropical countries included between 25 degrees north latitude and 25 degrees
south latitude, particularly in southeast Asia and epidemic in the Caribbean,
West-Africa, tropical American and Pacific Islands. Further spread will depend on
the invasion of Aedes aegypti into new areas in South America. Maintenance of
dengue is supported by an increasing demography, uncontrolled urbanization and
climatic conditions favorable to the vectors. Spread of dengue is primarily
caused by modern transportation, especially aircraft. No vaccine and no specific
treatment exist so that mosquito control is the only way to reduce the incidence
of dengue around the world. Dengue is, obviously, an important risk for travelers
going to endemic areas.
PMID- 10689246
TI - Indigenous malaria in a suburb of Ghent, Belgium.
AB - We report here details of a patient with Plasmodium falciparum malaria which was
acquired in the vicinity of Ghent (Evergem) in July 1997. Indigenous malaria
disappeared from Belgium in 1938. Due to an increase in international travel, the
influx of migrant labor and the changing environmental conditions, there has been
an upsurge of imported malaria. Airport- and port-malaria is acquired through the
bite of a tropical anophelline mosquito by people whose geographical history
excludes exposure to this vector in its natural habitat. As far as we know, only
two cases of port-malaria have been reported: in Marseille. We describe here
another possible case of port-malaria due to infection with P. falciparum in a 42
year-old woman with an underlying non-Hodgkin lymphoma.
PMID- 10689247
TI - Prevalence of nonfatal coronary heart disease among American adults.
AB - BACKGROUND: Few national estimates of the prevalence of coronary heart disease in
the United States are available. METHODS: By using data from the Third National
Health and Nutrition Examination Survey (1988 to 1994), we estimated prevalence
of angina pectoris by questionnaire, self-reported myocardial infarction, and
electrocardiographically (ECG)-defined myocardial infarction. RESULTS: Among
participants aged >/=40 years who attended the medical examination, the age
adjusted prevalence of angina pectoris, self-reported myocardial infarction, and
ECG-defined myocardial infarction were 5.8% of 9255, 6.7% of 9250, and 3.0% of
8206 participants, respectively. Among participants aged >/=65 years compared
with those aged 40 to 64 years, the prevalence of a self-reported myocardial
infarction was more than 3 times higher and that of ECG-defined myocardial
infarction more than 4 times higher. The prevalences of self-reported myocardial
infarction and ECG-defined myocardial infarction, but not angina pectoris, were
higher among men than women. Among women, prevalence of angina pectoris and self
reported myocardial infarction were highest among blacks; among men, these
coronary heart diseases were somewhat higher among whites. Prevalence of ECG
defined myocardial infarction were similar for all 3 race or ethnicity groups in
either sex. The age-adjusted prevalence of coronary heart disease defined by the
presence of any of these conditions was 13.9% among men and 10.1% among women.
CONCLUSIONS: Although the management of coronary heart disease has improved
during the past 2 decades, it remains an important prevalent disease burden among
adults.
PMID- 10689248
TI - Three-dimensional echocardiographic assessment of annular shape changes in the
normal and regurgitant mitral valve.
AB - OBJECTIVES: To compare mitral annular shape and motion throughout the cardiac
cycle in patients with normal hearts versus those with functional mitral
regurgitation (FMR). BACKGROUND: The causes of mitral regurgitation without
valvular disease are unclear, but the condition is associated with changes in
annular shape and dynamics. Three-dimensional (3D) imaging provides a more
comprehensive view of annular structure and allows accurate reconstructions at
high spatial and temporal resolution. METHODS: Nine normal subjects and 8
patients with FMR undergoing surgery underwent rotationally scanned
transesophageal echocardiography. At every video frame of 1 sinus beat, the
mitral annulus was manually traced and reconstructed in 3D by Fourier series.
Annular projected area, nonplanarity, eccentricity, perimeter length, and
interpeak and intervalley spans were determined at 10 time points in systole and
10 points in diastole. RESULTS: The mitral annulus in patients with FMR had a
larger area, perimeter, and interpeak span than in normal subjects (P <.001 for
all). At mid-systole in normal annuli, area and perimeter reach a minimum,
nonplanarity is greatest, and projected shape is least circular. These cyclic
variations were not significant in patients with FMR. Annular area change closely
paralleled perimeter change in all patients (mean r = 0.96 +/- 0.07).
CONCLUSIONS: FMR is associated with annular dilation and reduced cyclic variation
in annular shape and area. Normal mitral valve function may depend on normal
annular 3D shape and dimensions as well as annular plasticity. These observations
may have implications for design and selection of mitral annular prostheses.
PMID- 10689249
TI - When not doing tests is the right thing to do.
PMID- 10689250
TI - Increase in ST-segment elevation immediately after reperfusion: cause and
meaning.
PMID- 10689251
TI - Cardiology, for what it's worth.
PMID- 10689252
TI - Efficient utilization of echocardiography for the assessment of left ventricular
systolic function.
AB - BACKGROUND: We hypothesized that patients could be selected for echocardiographic
evaluation of left ventricular (LV) systolic function on the basis of historic,
clinical, radiographic, and electrocardiographic criteria. METHODS AND RESULTS:
We prospectively evaluated 300 consecutive inpatients referred for the
echocardiographic assessment of LV function, of whom 124 (41%) had LV systolic
dysfunction (LVSD) (LV ejection fraction <0.45). Among the historic variables,
male sex was the only predictor of LVSD, whereas of the abnormal physical and
radiographic findings, cardiomegaly on chest radiography was the only predictor.
Among the electrocardiographic findings, the presence of left bundle branch block
was positively correlated with the presence of LVSD, whereas a normal
electrocardiogram was negatively correlated with this finding. Only 2 patients
with LVSD had a normal electrocardiogram. The addition of significant predictors
on physical examination and chest radiography doubled the predictive value of the
historic variables for determining LVSD. The addition of electrocardiographic
findings further doubled the predictive value of the model. Almost 45% of the
predictive power of the final multivariate model (chi-square of 48 of the total
chi-square of 108) was based on the absence of normal electrocardiogram in
patients with LVSD. When chest radiographic findings were excluded from the
model, the overall predictive power of the model did not change, with the normal
electrocardiogram gaining greater prominence: Full 56% of the predictive power of
the model (chi-square of 60 of the total chi-square of 108) resided in the
ability of a normal electrocardiogram to discriminate between patients with and
those without LVSD. CONCLUSIONS: Historic, chest radiographic, and
electrocardiographic variables can be used to predict low likelihood of LVSD on
echocardiography. In particular, when the electrocardiogram is normal, it is
extremely unlikely to have LVSD. It can be argued that such patients should not
be referred for echocardiography.
PMID- 10689253
TI - Infusion versus bolus contrast echocardiography: a multicenter, open-label,
crossover trial.
AB - BACKGROUND: In current practice, contrast echocardiography is performed with
single or multiple bolus injections, which often result in an uncontrolled period
of attenuation followed by transient left ventricular opacification (LVO).
Because a "slow bolus" appears to reduce attenuation and prolong LVO, we
hypothesized that a controlled infusion of contrast might provide a more uniform
contrast effect with less attenuation and longer contrast duration. METHODS AND
RESULTS: We sought to test the hypothesis by using an infusion of contrast
(DEFINITY [perflutren], The DuPont Pharmaceuticals Co, Medical Imaging, North
Billerica, Mass) that is stable when diluted in saline in a randomized,
multicenter, controlled, crossover trial. Sixty-four patients with poor
noncontrast images were recruited at 3 centers and randomly assigned to 2 single
"slow" bolus injections of contrast (10 microL/kg each over a period of 30 to 60
seconds) or an infusion (1. 3 mL in 50 mL normal saline initially at 4.0 mL/min)
of contrast. Patients then returned within 24 to 72 hours for the alternative
form of contrast delivery. Three independent experienced echocardiographers
viewed 30 seconds of videotape for all optimal baseline and optimal contrast
images to score LVO and qualitatively assessed endocardial border evaluability.
The duration of adequate LVO then was independently assessed by review of the
entire videotape. Three independent sonographers traced single-frame, digitally
captured images to measure the length of the contiguous endocardial border
visualized. Both bolus and infusion administration demonstrated improved LVO
(>90% by all blinded readers, P <.01) and endocardial border visualized (mean
increase of 1.8 to 4.7 cm at both end-diastole and end-systole, all P <.05) as
compared with baseline images. However, contrast infusion resulted in a longer
duration of LVO (range of mean durations for each reader, 158 to 174 seconds
longer, P <.05) and a shorter duration of attenuation (18 to 54 seconds, P <.05)
compared with either bolus injection. There were no severe adverse events with
contrast infusion. CONCLUSIONS: Contrast echocardiography delivered as an
infusion optimizes the contrast effect by decreasing the attenuation period,
extending the LVO duration, and providing a uniform contrast effect that may be
useful in obtaining multiple echocardiographic views, stress echocardiography,
myocardial perfusion imaging, and applications in which blood flow must be
quantified.
PMID- 10689254
TI - Effects of mental stress on brachial artery flow-mediated vasodilation in healthy
normal individuals.
AB - BACKGROUND: Mental stress is associated with increased risk for cardiovascular
events, possibly because of acute increases in endogenous catecholamines.
Recently, brachial artery flow-mediated vasodilation has been used for
noninvasive assessment of macrovascular endothelial function. The effect of
mental stress and its associated changes in sympathetic activation on brachial
artery endothelium-dependent vasomotor tone in vivo remains unknown. METHODS AND
RESULTS: Two-dimensional ultrasound was used to measure brachial artery flow
mediated vasodilation before and after mental stress (provoked by a standard
arithmetic challenge) in 21 healthy individuals (10 men, 11 women; average age
23.5 years). The flow stimulus resulted from a 3-minute cuff occlusion of distal
forearm blood flow, causing distal hyperemia and a transient 2- to 3-fold
increase in brachial artery blood flow on cuff release. During mental stress,
heart rate increased on average by 29.6% and blood pressure increased on average
by 17.9%. The sympathetic stimulus resulted in a 64% average increase in flow
mediated vasodilator response (P <.001). The enhanced vasodilator response during
mental stress was similar for men and women. CONCLUSIONS: Mental stress can have
marked effects on endothelium-dependent, flow-mediated vasodilation in healthy,
normal individuals. Similar studies in individuals with impaired endothelial
function may further our understanding of the role of mental stress in the
development of cardiovascular events.
PMID- 10689255
TI - Interpretation of echocardiographic measurements: a call for standardization.
AB - BACKGROUND: Although echocardiography is used extensively in clinical medicine,
guidelines for quantitative interpretation of echocardiographic measurements are
unavailable. The goals of this investigation were to provide an overview of
scientific standards for formulating reference values, with clinical chemistry
used as a model, to evaluate published echocardiographic reference limits, to
survey clinical echocardiography laboratories regarding their interpretation of
echocardiographic measurements, and to provide recommendations for improving the
interpretation and reporting of echocardiographic measurements. METHODS AND
RESULTS: We reviewed the original reports of the International Federation of
Clinical Chemistry on guidelines for formulating reference values. We obtained
published reports on echocardiographic reference limits through searches of
electronic databases supplemented by a manual search of relevant bibliographies.
We also surveyed echocardiographic laboratories in 35 adult acute-care hospitals
in Eastern Massachusetts. Studies on echocardiographic reference values were
evaluated with the use of guidelines from clinical chemistry. Responses from the
29 participating echocardiographic laboratories were evaluated for their practice
of quantitative echocardiographic interpretation. There is considerable
heterogeneity in the echocardiographic reference values available in the
literature. There is also a lack of agreement in the literature and among
echocardiographers regarding the partitioning of reference values (by sex,
ethnicity, or age), the anthropometric measure to be used for indexation, and the
choice of cut-points for categorizing values within the abnormal range.
CONCLUSIONS: We advocate that echocardiographic reference limits be standardized
and a consensus generated regarding the partitioning of reference limits and the
indexation of echocardiographic measurements. Such measures can aid in
quantitative echocardiographic interpretation and render the results more
scientific and consistent.
PMID- 10689256
TI - Will the use of low-molecular-weight heparin (enoxaparin) in patients with acute
coronary syndrome save costs in Canada?
AB - BACKGROUND: One-year follow-up data from the Efficacy and Safety of Subcutaneous
Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) trial show that use of low
molecular-weight heparin (enoxaparin) compared with unfractionated heparin in
patients hospitalized with unstable angina or non-Q-wave myocardial infarction is
associated with a 10% reduction in the cumulative 1-year risk of death,
myocardial infarction, or recurrent angina. Given the higher acquisition cost of
enoxaparin relative to unfractionated heparin, we assessed whether the reduced
use of revascularization procedures and related care makes enoxaparin a cost
saving therapy in Canada. METHODS AND RESULTS: We analyzed cumulative 1-year
resource use data on the 1259 ESSENCE patients enrolled in Canadian centers (40%
of the total ESSENCE sample). Patient-specific data on use of drugs, diagnostic
cardiac catheterization, percutaneous transluminal coronary angioplasty, coronary
artery bypass grafting, and hospital days were available from the initial
hospital stay and cumulative to 1 year. Hospital resources were costed with the
use of data from a teaching hospital in southern Ontario that is a participant in
the Ontario Case Costing Project. During the initial hospital stay, use of
enoxaparin was associated with reduced use of diagnostic catheterization and
revascularization procedures, with the largest effect being reduced use of
percutaneous transluminal coronary angioplasty (15.0% vs 10.6%; P =.03). At 1
year, the reduced risk and costs of revascularization more than offset increased
drug costs for enoxaparin, producing a cost-saving per patient of $1485 (95%
confidence interval $-93 to $3167; P =.06). Sensitivity analysis with lower
hospital per diem costs from a community hospital in Ontario still predicts cost
savings of $1075 per patient over a period of 1 year. CONCLUSIONS: The
acquisition and administration cost of enoxaparin is higher than for
unfractionated heparin ($101 vs $39), but in patients with acute coronary
syndrome, the reduced need for hospitalization and revascularization over a
period of 1 year more than offsets this initial difference in cost. Evidence from
this Canadian substudy of ESSENCE supports the view that enoxaparin is less
costly and more effective than unfractionated heparin in this indication.
PMID- 10689257
TI - A comparison of electrocardiographic changes during reperfusion of acute
myocardial infarction by thrombolysis or percutaneous transluminal coronary
angioplasty.
AB - BACKGROUND: Different electrocardiographic changes have been described during
thrombolytic therapy for acute myocardial infarction to indicate successful
reperfusion. The occluded coronary artery also can be reopened by percutaneous
transluminal coronary angioplasty (PTCA). This study was performed to compare
electrocardiographic changes during primary or rescue PTCA and thrombolytic
therapy. The electrocardiographic changes were studied directly at the moment of
reperfusion during PTCA. METHODS AND RESULTS: Continuous 12-lead
electrocardiographic monitoring was performed in 110 patients with acute
myocardial infarction undergoing a reperfusion intervention (thrombolytic therapy
or primary or rescue PTCA) to assess electrocardiographic changes during
reperfusion. Patency and Thrombolysis In Myocardial Infarction flow in the
infarct-related artery were assessed by coronary angiography. During reperfusion
of the infarct-related coronary artery, early signs of reperfusion were an
increase of ST-segment deviation (30%), ST-segment normalization (70%), and
terminal T-wave inversion (60%); only 11% of patients showed no ST-segment
changes. Thrombolytic therapy was significantly more often accompanied by a
transient increase in ST-segment deviation compared with primary PTCA.
Accelerated idioventricular rhythm was documented in 51%, an increase in the
number of ventricular premature complexes in 42%, nonsustained ventricular
tachycardia in 7%, and bradycardia in 18% of all patients. CONCLUSIONS: This
study confirms the occurrence of specific electrocardiographic changes at the
time of reperfusion. The pattern of ST-segment change upon reperfusion relates to
the type of treatment. Awareness of electrocardiographic changes at the moment of
reperfusion will help to select patients for rescue PTCA and can be used to
assess the effect of future pharmacologic interventions to limit reperfusion
damage.
PMID- 10689258
TI - Stents covered by autologous venous grafts: feasibility and immediate and long
term results.
AB - BACKGROUND: Previous experimental studies with a new covered stent, the
autologous venous graft-covered stent (AVGCS), have shown favorable results. The
aim of this study was to evaluate the feasibility and safety of this new
technique in human coronary arteries and to compare the long-term outcome with
uncovered stents. METHODS AND RESULTS: A venous graft was removed from an upper
limb. A conventional stent then was covered by the venous graft. Fifty-eight
AVGCS were implanted in 56 patients, including 16 patients with acute coronary
syndromes (ACS). Additionally, in 114 patients, 138 uncovered stents were
implanted, serving as a control group, including 38 patients with ACS. The
procedure was successful in all patients. Stent thrombosis was observed in 3
patients in the control group and in 1 patient with an AVGCS. There was a trend
for the minimal luminal diameter to be greater in the AVGCS group at follow-up (P
=.07), and statistical significance was observed in patients with ACS (P <.01).
The target vessel revascularization and the restenosis rates were similar between
the 2 groups. In patients with ACS, the restenosis rate was less (P <.04) and
there was a trend for target vessel revascularization to be less in covered
stents (P =.09). The event-free survival rate at 4 years was 85% in the AVGCS
group versus 81% in the control group (P = not significant); in ACS it was 94%
versus 78%, respectively (P = not significant). Stents covered by thicker venous
grafts were associated with improved clinical outcome. CONCLUSIONS: Stents
covered by autologous venous grafts may be safely prepared without complications.
This technique may prove to be a useful means, especially in patients with ACS.
PMID- 10689259
TI - Association between total homocyst(e)ine and the likelihood for a history of
acute myocardial infarction by race and ethnicity: Results from the Third
National Health and Nutrition Examination Survey.
AB - BACKGROUND: Few studies examining the association between total homocyst(e)ine
and coronary heart disease have included blacks or Hispanics. METHODS: Data from
the third National Health and Nutrition Examination Survey (3173 patients), a
nationally representative survey of US adults, were used to examine the relation
between total homocyst(e)ine and an electrocardiogram or a physician's diagnosis
of acute myocardial infarction (259 patients) among whites, blacks, and Mexican
Americans >/=40 years old. RESULTS: Vitamin B(12) and serum folate concentrations
were significantly lower among persons with a total homocyst(e)ine concentration
>/=15 micromol/L than among those with a total homocyst(e)ine concentration =10
micromol/L. Persons with a total homocyst(e)ine concentration >/=15 micromol/L
were also older and more likely to be hypertensive, have a higher cholesterol
concentration, and smoke. Compared with persons with a total homocyst(e)ine
concentration =10 micromol/L, persons with a concentration >/=15 micromol/L had
an odds ratio (OR) for myocardial infarction of 1.8 (95% confidence interval
[CI], 1.2-2.9) after adjustment for cardiovascular disease risk factors. Similar
associations were noted among whites (OR 1.8, 95% CI, 1.1-3.1) and blacks (OR
1.9, 95% CI, 0.8-4.2); a more modest association was noted among Mexican
Americans (OR 1.2, 95% CI, 0.3-5.0). The association between total homocyst(e)ine
and myocardial infarction was also more pronounced in persons without
hypertension or diabetes. CONCLUSIONS: Almost a 2-fold increased likelihood of
myocardial infarction among persons with a total homocyst(e)ine concentration
>/=15 micromol/L was noted in this nationally representative survey. The
magnitude of the association did not differ by race or ethnicity.
PMID- 10689260
TI - Cigarette smoking status and outcome among patients with acute coronary syndromes
without persistent ST-segment elevation: effect of inhibition of platelet
glycoprotein IIb/IIIa with eptifibatide. The PURSUIT trial investigators.
AB - BACKGROUND: Studies have shown that cigarette smokers constitute a substantial
proportion of patients with acute coronary syndromes (ACS) and have platelet-rich
coronary thrombi. We characterized the influence of smoking status on outcome of
patients with ACS without persistent ST-segment elevation and tested the
hypothesis that selective inhibition of the platelet glycoprotein IIb/IIIa
receptor with eptifibatide would improve outcomes among cigarette smokers.
METHODS: The study population included patients enrolled in the PURSUIT trial
(Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using
Integrilin Therapy) with known smoking status presenting with ischemic chest pain
=24 hours and having either ischemic electrocardiographic changes without
persistent ST-segment elevation or elevated creatine kinase MB levels. Patients
were randomly assigned to receive a bolus and infusion of either eptifibatide or
placebo in addition to standard therapy. The primary end point was a composite of
death or nonfatal myocardial infarction within 30 days. RESULTS: Of the 9406
patients with known smoking status, 2677 were current smokers, 3086 were former
smokers, and 3643 were nonsmokers. Cigarette smokers had better 30-day outcomes
(12.3%, 16.8%, and 15.4% for smokers, former smokers, and nonsmokers,
respectively; P =.001). However, after adjusting for differences in baseline
clinical variables, smoking status was not a predictor of 30-day outcome (P
=.45). There was a reduction in the composite end point overall with eptifibatide
compared with placebo (14.3% vs 15. 7%, P =.054) but no interaction between
smoking status and treatment strategy (P =.68). CONCLUSIONS: Among patients with
ACS without persistent ST-segment elevation, cigarette smokers had better short
term outcomes because of their more favorable clinical profile. Although prior
studies have suggested that smokers more commonly have platelet-rich thrombi than
nonsmokers, eptifibatide did not result in more improvement in their outcome
compared with former smokers or nonsmokers.
PMID- 10689261
TI - Guidelines for the diagnosis and management of unstable angina and non-Q-wave
myocardial infarction: proposed revisions. International Cardiology Forum.
AB - BACKGROUND: In 1994, the United States Agency for Health Care Policy and Research
issued clinical practice guidelines for the diagnosis and management of unstable
angina and non-Q-wave myocardial infarction. In the past 5 years, rapid progress
has been made in the management of patients with unstable coronary syndromes, yet
current guidelines do not necessarily reflect these advances. METHODS AND
RESULTS: An international forum of cardiology investigators reviewed existing
guidelines and discussed areas in which the diagnosis and treatment of unstable
angina and non-Q-wave myocardial infarction should be modified. It was agreed
that there is sufficient evidence to recommend the following changes: (1) use of
serum cardiac markers should be expanded to include troponin I and T levels as
diagnostic and prognostic tools; (2) low-molecular-weight heparins should replace
unfractionated heparin as antithrombotic agents; (3) new classes of antiplatelet
agents are recommended in addition to aspirin; and (4) the use of cholesterol
lowering drugs is appropriate in the long-term management of these patients.
CONCLUSIONS: Evidence from clinical trials within the last 5 years requires that
significant changes be made to existing guidelines for the diagnosis and
management of unstable angina and non-Q-wave myocardial infarction. The
recommendations detailed should be considered in the creation and implementation
of updated guidelines.
PMID- 10689263
TI - Physiologic response to gain and loss in coronary minimal luminal diameter in
patients treated with coronary angioplasty: prediction of restenosis on the basis
of exercise capacity.
AB - BACKGROUND: The effect of percutaneous transluminal coronary angioplasty (PTCA)
on physiologic measurements has previously been shown, but the relation between
physiologic response and degree of change in coronary luminal diameter is not
known. We studied the relation between exercise capacity and minimal luminal
diameter before and after PTCA. We also explored the usefulness of measurement of
attenuation in exercise capacity after PTCA to predict the likelihood of
restenosis. METHODS: Bicycle exercise testing was performed 2 weeks before and 2
and 20 weeks after PTCA in 395 consecutively enrolled patients. Angiograms
obtained before and after PTCA and 20 weeks afterward were analyzed by
quantitative coronary angiography. Restenosis was defined as both angiographic
(>/=50% diameter stenosis at follow-up angiography) and clinical (target-vessel
revascularization), after successful PTCA. Exercise capacity was defined as the
cumulative work performed divided by body weight (watt x minutes x kilograms(
1)). RESULTS: Exercise capacity increased 43% (P <.0001) from before PTCA to 2
weeks after PTCA (early increase) and decreased 4% (P =.01) from 2 to 20 weeks
after PTCA (late decrease). The gain in minimal luminal diameter (Minimal luminal
diameter after - Minimal luminal diameter before) was 0.92 +/- 0.46 mm. The loss
in minimal luminal diameter (Minimal luminal diameter after PTCA - Minimal
luminal diameter at follow-up examination) was 0.27 +/- 0.42 mm. Exercise
capacity and minimal luminal diameter measured before PTCA were positively
correlated (coefficient 3.3; R = 0.12; P =.01). Gain in minimal luminal diameter
correlated with the early increase in exercise capacity (coefficient -3.8; R =
0.23; P <.0001). Loss in minimal luminal diameter correlated with the late
decrease in exercise capacity (coefficient 3.3; R = 0.20; P <.0001). Multivariate
logistic regression analysis revealed that the late decrease in exercise capacity
was independently predictive of both angiographically (odds ratio 1.13; P <.0001)
and clinically (odds ratio 1.12; P <.0001) defined restenosis. CONCLUSIONS: The
results demonstrated a linear relation between the severity of coronary stenosis
and exercise capacity measured before PTCA. The degree of coronary luminal
enlargement achieved with angioplasty and the luminal reduction that occurred
between PTCA and follow-up evaluation correlated with increases and decreases in
exercise capacity. Attenuation in exercise capacity was found to be a strong
predictor of restenosis.
PMID- 10689262
TI - Predictors of death and reinfarction at 30 days after primary angioplasty: the
GUSTO IIb and RAPPORT trials.
AB - BACKGROUND: Thirty-day death among recipients of fibrinolytic therapy for acute
myocardial infarction (MI) is tightly correlated with easily obtainable key
demographic and clinical parameters such as age, blood pressure, heart rate, and
infarct location. Similar data for primary angioplasty are not available. METHODS
AND RESULTS: Data from 2 large, contemporary, primary angioplasty trials were
formally combined and analyzed with respect to death and death/repeat MI at 30
days through the use of multivariate logistic regression models. The 1048
patients had a median age of 62 years, and 26% were women. Thirty-eight percent
had an anterior infarction. The patients underwent angioplasty at a median delay
from symptom onset of 3.8 hours. Death was independently predicted by increasing
age (adjusted odds ratio [OR] per decade 2.32, 95% confidence interval [CI] 1.60
to 3.42), whereas a history of smoking (OR 0.29, CI 0.13 to 0.64), Thrombolysis
in Myocardial Infarction (TIMI) flow grade 3 after angioplasty (OR vs TIMI <3
0.21, CI 0.10 to 0.45) and higher systolic blood pressure (OR per 10 mm Hg 0.73,
CI 0.62 to 0. 87) were associated with lower mortality rates. Death or repeat MI
was independently associated with increasing age (OR per decade 1.40, CI 1.13 to
1.76) and anterior location of the index MI (OR 1.89, CI 1.12 to 3.20). TIMI
grade 3 flow (OR vs TIMI <3 0.40, CI 0.23 to 0. 68) and higher systolic blood
pressure (OR per 10 mm Hg 0.79, CI 0. 71 to 0.89) were associated with a lower
incidence of death/repeat MI. Time to angioplasty, heart rate, extent of coronary
artery disease, participation in 1 of the 2 trials, and all common coronary risk
factors did not significantly predict outcome. CONCLUSIONS: Death and
reinfarction after primary angioplasty are predominantly predicted by age,
hemodynamic instability, and the attainment of TIMI 3 flow in the infarct artery.
PMID- 10689264
TI - Differences between patients with heart failure treated by cardiologists,
internists, family physicians, and other physicians: analysis of a large,
statewide database.
AB - BACKGROUND: The management of heart failure (HF) by cardiologists may be better
than that of other physicians in that cardiologists' treatment choices more
frequently conform with published guidelines and the results of clinical trials.
Whether cardiologists' management of HF is more or less cost-effective is up for
debate. METHODS: Information on all 1995 New York state hospital discharges
assigned ICD-9-CM codes indicative of HF in the principal diagnosis position was
obtained. Demographic and clinical characteristics, process of care, resource
utilization, and short-term HF-related outcomes were compared between patients of
cardiologists and patients of other physicians. RESULTS: A total of 44,926
patients were identified, with 10,506 (23%) receiving care from cardiologists,
28,300 (63%) from internists, 4812 (11%) from family practitioners, and 1308 (3%)
from other physicians. Patients of cardiologists were younger, more frequently
male, and less frequently residents of nursing homes. They were more likely to
have associated cardiovascular diagnoses but less likely to have comorbid general
medical conditions. Patients of cardiologists were more likely to undergo cardiac
catheterization (9%) than those of internists (3%) and family practice (2%)
physicians but had similar adjusted hospital length of stay and charges.
Mortality and hospital readmission rates for HF were similar among the groups.
Patients in the "other" group (managed mostly by surgeons) were the youngest,
underwent more invasive and cardiac surgical procedures, and had the longest
length of stay and highest hospital charges. CONCLUSIONS: Cardiologists'
management of HF is not economically disadvantageous. The relations among
physician specialty, process of care, resource utilization, and clinical outcomes
require further study before rational and evidence-based health care staffing
recommendations can be formulated.
PMID- 10689265
TI - Detection of left ventricular regional relaxation abnormalities and asynchrony in
patients with hypertrophic cardiomyopathy with the use of tissue Doppler imaging.
AB - BACKGROUND: It is well known that the distribution and magnitude of left
ventricular (LV) hypertrophy are not uniform in patients with hypertrophic
cardiomyopathy (HCM), which results in regional heterogeneity of LV early
diastolic function. The advent of tissue Doppler imaging (TDI) has allowed the
noninvasive evaluation of regional LV wall motion velocities. The aim of this
study was to evaluate regional LV relaxation abnormalities and asynchrony
noninvasively in patients with HCM by using pulsed and color-coded TDI. METHODS
AND RESULTS: We studied 20 patients with asymmetric septal hypertrophy (HCM
group) and 18 age-matched normal patients (control group). The peak early
diastolic motion velocity (Ew) and time from the aortic component of the second
heart sound to the peak of the Ew (II(A)-Ew) were measured by pulsed TDI. The
myocardial velocity gradient during early diastole (MVG-Ew) also was measured by
color-coded TDI. Mean values for these parameters were determined on the basis of
measurements made at 2 sites of the ventricular septum or posterior wall at the
levels of chordae tendineae and papillary muscles. The mean Ew and mean MVG-Ew
for the ventricular septum and posterior wall were significantly lower, and mean
II(A)-Ew was significantly prolonged in the HCM group compared with the control
group. This difference was most pronounced in the hypertrophied ventricular
septum of the HCM group. The standard deviations of II(A)-Ew for the ventricular
septum and posterior wall were significantly greater in the HCM group than in the
control group. The time constant of LV pressure decay during isovolumic diastole
(tau) correlated inversely with Ew and MVG-Ew and correlated directly with II(A)
Ew. Furthermore, tau correlated directly with the standard deviation of the II(A)
Ew. CONCLUSIONS: LV early diastolic function in patients with HCM may be mediated
by an augmentation of regional LV relaxation abnormalities and asynchrony.
PMID- 10689266
TI - Effects of amlodipine on exercise tolerance, quality of life, and left
ventricular function in patients with heart failure from left ventricular
systolic dysfunction.
AB - BACKGROUND: A preliminary study suggested that the long-acting late-generation
calcium-channel blocker amlodipine has favorable effects on exercise tolerance
and is safe to use in heart failure, in contrast to earlier generation agents.
The goal of 2 multicenter studies was to assess the effect of adjunctive therapy
with amlodipine in addition to standard therapy on exercise capacity, quality of
life, left ventricular function, and safety parameters in patients with heart
failure and left ventricular systolic dysfunction. METHODS: Two large multicenter
trials examining the effects of amlodipine on these parameters over a 12-week
period of therapy were undertaken in patients with mild to moderate heart failure
and left ventricular systolic dysfunction. A total of 437 patients with stable
heart failure were studied in a randomized, double-blind, placebo-controlled
prospective design. RESULTS: Amlodipine at a dose of 10 mg/day in addition to
standard therapy in such patients was associated with no significant difference
in change in exercise tolerance on a Naughton protocol compared with placebo in
each trial. Among all patients taking amlodipine, exercise time increased 53 +/-
9 (SE) seconds; exercise time for those taking placebo increased 66 +/- 9 seconds
(P = not significant). There were no significant differences in changes of
quality of life parameters between amlodipine- and placebo-treated patients, and
there were no significant differences in symptom scores or New York Heart
Association classification between groups. Left ventricular function (measured as
ejection fraction) improved 3. 4% +/- 0.5% in amlodipine-treated patients and
1.5% +/- 0.5% in placebo-treated patients (P =.007). There was no statistically
significant excess of important adverse events (episodes of worsening heart
failure in 10% amlodipine-treated vs 6.3% of placebo-treated patients) or
differences in need for changes in background medication between groups.
CONCLUSIONS: The addition of 10 mg of amlodipine per day to standard therapy in
patients with heart failure is associated with no significant improvement in
exercise time compared with placebo therapy over a 12-week period, and there was
no increased incidence of adverse events. These data suggest that the addition of
amlodipine to standard therapy in heart failure will not result in additional
efficacy per se beyond standard therapy.
PMID- 10689267
TI - A rationale for the use of beta-blockers as standard treatment for heart failure.
AB - BACKGROUND: Cardiac sympathetic activation is one of the major and earlier
changes observed in patients with heart failure. Its relation to the severity of
the disease and its independent prognostic value show that it may directly
contribute to the progression of heart failure. beta-Blockers are the most
effective tool to counteract the untoward effects of sympathetic activation on
the cardiovascular system. METHODS AND RESULTS: We reviewed the results of the
placebo-controlled, double-blind studies about the effects of beta-blockers in
patients with heart failure. These studies have involved almost 10,000 patients
to date and have consistently shown that the long-term administration of beta
blockers is associated with a highly significant improvement in both left
ventricular function and prognosis of the patients with heart failure. The
evidence supporting the use of beta-blockers now equals or even surpasses that of
angiotensin-converting enzyme inhibitors; therefore beta-blockers should be
considered part of standard therapy. Issues that remain unclarified include the
mechanisms through which beta-blockers may improve cardiac function and their
tolerability and efficacy in specific groups of patients (such as those with
asymptomatic left ventricular dysfunction, severe heart failure, the elderly, or
those with left ventricular diastolic dysfunction). It is not currently clear
whether the pharmacologic differences between individual beta-blockers are
clinically relevant. If they are, the potential for even greater benefit with
certain agents exists. It is hoped that these issues will be clarified by the
results of ongoing multicenter trials.
PMID- 10689268
TI - Magnesium supplementation in the prevention of arrhythmias in pediatric patients
undergoing surgery for congenital heart defects.
AB - BACKGROUND: The efficacy of magnesium in the prevention of arrhythmias in
pediatric patients after heart surgery remains unknown. Therefore we
prospectively examined the effect of magnesium treatment on the incidence of
postoperative arrhythmias in pediatric patients undergoing surgical repair of
congenital heart defects. METHODS AND RESULTS: Twenty-eight pediatric patients
undergoing heart surgery with cardiopulmonary bypass were prospectively, randomly
assigned in a double-blind fashion to receive intravenous magnesium (magnesium
group, n = 13; 30 mg/kg) or saline (placebo group, n = 15) immediately after
cessation of cardiopulmonary bypass. Magnesium, potassium, and calcium levels
were measured at defined intervals during surgery and 24 hours after surgery.
Continuous electrocardiographic documentation by Holter monitor was performed for
24 hours after surgery. Magnesium levels were significantly decreased below the
normal reference range for patients in the placebo group compared with the
magnesium group on arrival in the intensive care unit and for 20 hours after
surgery. Magnesium levels remained in the normal range for patients in the
magnesium group after magnesium supplementation. In 4 patients in the placebo
group (27%), junctional ectopic tachycardia developed within the initial 20 hours
in the intensive care unit. No junctional ectopic tachycardia was observed in the
magnesium group (P =.026). CONCLUSIONS: Although this study was originally
targeted to include 100 patients, the protocol was terminated because of the
unacceptable incidence of hemodynamically significant junctional ectopic
tachycardia that was present in the placebo group. Thus low magnesium levels in
pediatric patients undergoing heart surgery are associated with an increased
incidence of junctional ectopic tachycardia in the immediate postoperative
period.
PMID- 10689269
TI - Left ventricular function, cardiac dysrhythmias, atrial activation, and volumes
in nondipper hypertensive individuals with left ventricular hypertrophy.
AB - BACKGROUND: Arrhythmic patterns and left ventricular geometric adaptations to
pressure overload were investigated in 76 patients with untreated borderline-to
moderate sustained essential hypertension studied by 2-dimensional and M-mode
echocardiography, 12-lead, Holter, and signal-averaged electrocardiography, and
ambulatory blood pressure monitoring. METHODS AND RESULTS: Sixty-two age- and sex
matched normal adults were chosen for data comparison. Hypertrophic hypertensive
patients were subdivided into 2 subgroups: 44 patients with nocturnal blood
pressure reduction (dippers) and 32 patients without it (nondippers). Common
afterload and diastolic function indexes were found to be lower in combined
nondipper and dipper groups, but only fractional shortening decreased in
nondippers. The number of premature atrial and ventricular contractions per hour
was high in dippers and nondippers, with no statistically significant differences
between them; atrial and ventricular complex dysrhythmias were similar. Signal
averaged electrocardiography showed a prolonged P-wave duration in dipper and
nondipper patients with high atrial volumes but no late ventricular potentials
and no difference in quantitative P-wave analysis. Left atrial volumes, P-wave
duration, and premature atrial contractions were found to be positively linked to
left ventricular hypertrophy. In nondipper patients a linear correlation was
observed between left atrial volume and P-wave duration, although
supraventricular ectopic activity was connected to left atrial volume enlargement
both in dipper and nondipper patients. CONCLUSIONS: These data suggest that the
nondipper pattern is not linked to a worse arrhythmogenic substrate; only atrial
volume increase may be related to significant supraventricular activity and
prolonged atrial activation in nondipper patients, but late ventricular
potentials are uncommon in hypertrophic hypertensive patients.
PMID- 10689270
TI - beta2-adrenergic receptor polymorphisms at amino acid 16 differentially influence
agonist-stimulated blood pressure and peripheral blood flow in normal
individuals.
AB - BACKGROUND: The Gly16 beta(2)-adrenergic receptor (beta(2)AR) polymorphism is a
common variant of the beta(2)AR that displays depressed function caused by
enhanced receptor downregulation in vitro compared with the Arg16 receptor.
METHODS AND RESULTS: We studied 20 healthy, normotensive, nonsmoking white
individuals who were homozygous for either the Arg16 (n = 10) or the Gly16 (n =
10) genotype. Plethysmographic lower-limb blood flow, blood pressure, and 2
dimensional echocardiograms were recorded at baseline and after 15-minute
incremental infusions of terbutaline (100 to 300 ng/kg per minute). Baseline
heart rates, blood pressures, and flows were similar in both groups, but at the
maximum dose of terbutaline, limb blood flow was less (P <.05), calculated
vascular resistance was greater (P <.05), and systolic and diastolic blood
pressures were greater in patients with Gly16 than in those with Arg16 (both P
<.05). In contrast, terbutaline-stimulated heart rates were not different. In a
separate group of 20 homozygous individuals (12 Arg16, 8 Gly16), there were no
differences in 2-dimensional echocardiographically determined ventricular
function. CONCLUSIONS: We conclude that the Gly16 beta(2)AR polymorphism imparts
attenuated vasodilatory responses to catecholamines in normal human beings and is
an important genetic component in the regulation of peripheral blood flow and
systemic arterial pressure.
PMID- 10689271
TI - A controlled trial of cardiac rehabilitation in the home setting using
electrocardiographic and voice transtelephonic monitoring.
AB - OBJECTIVE: The goal of this study was to compare the effectiveness of home-based,
transtelephonically monitored cardiac rehabilitation with standard, on-site,
supervised cardiac rehabilitation. BACKGROUND: Participation in cardiac
rehabilitation has been demonstrated to increase exercise capacity, decrease
cardiovascular symptoms, improve psychosocial status, and decrease total and
cardiovascular mortality rates in patients with coronary heart disease. Because
of multiple factors, national overall participation is only at 15% of eligible
patients. METHODS: Effects of a 3-month home-based, transtelephonically monitored
rehabilitation program (n = 83 patients) with simultaneous voice and
electrocardiographic transmission to a centrally located nurse coordinator were
compared with effects of a standard on-site rehabilitation program (n = 50
patients). The study design was a multicenter, controlled trial. Primary outcome
variables were peak aerobic capacity and quality of life, as measured by the
Health Status Questionnaire. RESULTS: Patients in the home-based monitoring
program increased peak aerobic capacity to a similar degree as patients who
exercised on site (18% vs 23%). Quality of life domains of physical functioning,
social functioning, physical role limitations, emotional role limitations, bodily
pain, and energy/fatigue improved similarly in both groups. There were no
circulatory arrests or other major exercise-related medical events in either
group. A total of 3100 hours of home exercise were transtelephonically monitored.
CONCLUSIONS: Patients with coronary heart disease can effectively participate in
home-based, monitored cardiac rehabilitation, with exercise and quality of life
improvements comparable to those demonstrated at on-site programs.
PMID- 10689272
TI - Mitral repair in patients with a ruptured papillary muscle.
AB - BACKGROUND: The objective of this study was to evaluate the feasibility of a
modified papillary muscle repair procedure for a group of patients with ischemic
mitral regurgitation when ischemia/infarction has resulted in the rupture of a
papillary muscle. From January 1997 to January 1999, 843 patients underwent
mitral valve surgery in our hospital. Mitral reconstruction was performed in 520
(61.7%) patients, and 6 (1.2%) of these patients were found to have a rupture of
a papillary muscle at initial examination. METHODS AND RESULTS: A modified
papillary muscle repair procedure to reimplant the tip of the ruptured papillary
muscle "height- and/or length-adjusted" into a corresponding papillary muscle,
with the use of a sandwiched pericardium pledget-reinforced
polytetrafluoroethylene suture, was performed in 6 patients. Although the
underlying cause in this group of patients was ischemic, concomitant coronary
artery bypass grafting was performed in only 3 patients, with 1.3 grafts per
patient. Of these 6 patients, 3 (50%) were men; the mean age was 60.2 +/- 12.8
years. All patients had in addition to the papillary muscle repair procedure an
annuloplasty with a Carpentier-Edwards Physio-Ring. There was no early death in
this group of patients. Postoperative Doppler echocardiography showed
satisfactory mitral valve function in all patients and a significant
postoperative ventricular remodeling: The left ventricular end-diastolic diameter
decreased from 72.8 +/- 3.1 mm before surgery to 54.6 +/- 9.3 mm (P <.1) after
surgery; left ventricular systolic diameter also decreased (48.5 +/- 4.9 mm vs
38. 4 +/- 9.8 mm; P <.1), and a substantial reduction of left atrial diameter
(58.8 +/- 1.5 mm vs 49.7 +/- 4.1 mm; P <.1) was observed. Within the short mean
follow-up period of 8.6 +/- 7.5 months (2 to 26 months), there were no late
deaths, reoperations, or thromboembolic or bleeding complications. All patients
were in New York Heart Association functional class I or II at the time of follow
up. CONCLUSIONS: Our results indicate that our modified papillary muscle
reimplantation procedure is a valuable surgical tool with good survival results
in patients with ischemic mitral regurgitation caused by papillary muscle
rupture.
PMID- 10689273
TI - Lipoprotein(a) in atrial fibrillation.
PMID- 10689275
TI - Effects of exercise on QT dispersion in ischemic heart disease.
PMID- 10689277
TI - Low-molecular-weight heparin as optimal solution to therapeutic heparinization.
PMID- 10689279
TI - Increased expression of hemostasis markers in the coronary circulation in
patients with coronary artery disease.
PMID- 10689280
TI - Comparison of the effects of the mother and an unfamiliar adult female on
cortisol and behavioral responses of pre- and postweaning guinea pigs.
AB - In the guinea pig, the presence of the mother, but not littermates, has been
found to inhibit hypothalamic-pituitary-adrenal (HPA) responses during brief (30
60 min) exposure to novel surroundings both prior to and several weeks following
the completion of weaning. In the present study, we found that an unfamiliar
adult female inhibited plasma cortisol and vocalization responses of pre- and
postweaning guinea pigs during a 60-min exposure to a novel environment. However,
the presence of the mother still had a greater effect on the cortisol levels of
the young, at least during the preweaning period. The moderating influence of the
unfamiliar adult female on vocalizations and cortisol levels occurred despite
behavioral interactions, such as heightened aggression and sexual behavior, not
seen during tests with the mother. It is suggested that the unfamiliar adult
female's effectiveness in reducing HPA activity during exposure to novelty may
facilitate the change in patterns of social interaction occurring in recently
weaned animals.
PMID- 10689281
TI - The effect of early experience on learning and memory in cuttlefish.
AB - The effect of early experience on the growth and ontogeny of memory in cuttlefish
(Sepia officinalis) was studied using an associative learning protocol. Five
groups of cuttlefish were reared in different conditions (standard conditions,
SC; impoverished conditions, IC; enriched conditions, EC; impoverished then
enriched conditions, I/EC; enriched then impoverished conditions, E/IC) from
birth to the 3rd month of postembryonic life. Acquisition and retention of the
learning task were assessed at 1 and 3 months. Growth was slower and maturation
of memory abilities occurred later in cuttlefish from Group IC than in cuttlefish
from Group EC, with the maturation rate of memory in cuttlefish from Group SC
intermediate between these two groups. Retention performances of cuttlefish from
Groups I/EC and E/IC indicated that the environment of rearing during the 2nd
and/or 3rd months of life was crucial for the development of memory.
PMID- 10689282
TI - Spontaneous kicking behavior in infants: age-related effects of unilateral
weighting.
AB - The age-related effects of unilateral weighting on spontaneously generated kicks
in 18 healthy, full-term infants were investigated. The main question was whether
infants during the first half-year after birth reveal changes in how they adjust
to unilateral weighting. At 6 weeks, infants reduced the frequency of the
weighted leg and increased that of the unweighted leg whereas at 12 weeks the
frequency of kicking increased in both legs. At both ages, unilateral weighting
also resulted in differences on a number of kinematic parameters. By 18 and 26
weeks, such frequency and kinematic effects were no longer present. With regard
to interlimb couplings, a clear pattern of bilateral coordination was only
present at 26 weeks; these results suggest that the effects of unilateral
weighting are not directly related to the tightness of interlimb couplings. The
implications of these age-related differences for understanding developmental
changes in the control of leg movements are discussed. It is suggested that the
infants' improved ability to act in a task-specific manner as well as nonlinear
changes in the musculo-skeletal system and fine-tuning processes at a neural
level might be factors of importance.
PMID- 10689283
TI - A dissociation in infants' memory for stimulus size: evidence for the early
development of multiple memory systems.
AB - Adults' memory performance on recognition (explicit memory) tests is sensitive to
stimulus size, but their performance on priming (implicit memory) tests is not.
This memory dissociation is taken as evidence for two, functionally distinct
memory systems. Young infants, however, are thought to possess only a single
representational system that supports implicit memory; the system that supports
explicit memory is thought not to mature before 8-9 months of age. In two
experiments with 54 infants, we asked if 3-month-olds exhibit a memory
dissociation for stimulus size on recognition and priming tests. All infants
learned to move a mobile displaying +s of a given size. In Experiment 1, infants
recognized +s in the original size but not 33% smaller or larger. In Experiment
2, +s were effective memory primes in a reactivation task, irrespective of size.
The finding that young infants exhibit a memory dissociation for stimulus size
adds to growing evidence that two memory systems are functional from early in
development.
PMID- 10689284
TI - Comparative analyses of the role of postnatal development on the expression of
play fighting.
AB - Whether it is that animals are young so that they can play, or whether it is that
they play because they are young, play should be more prevalent in species that
have a greater degree of postnatal development. This hypothesis is tested by
comparative analyses within two mammalian orders (primates and muroid rodents)
using independent contrasts. This technique can account for the relative degree
of relatedness among the species. For both orders, the complexity or prevalence
of play fighting is compared to the degree of prenatal development (neonatal
weight/adult weight). In addition, the prevalence of play in primates is compared
to prenatal brain development (neonatal brain weight/adult brain weight).
Significant negative regressions show that 30% of the variance in the
distribution of play in the rodents is accounted for by the degree of prenatal
development of body size, and 60% of the variance in play in the primates is
accounted for by prenatal brain growth. The findings are thus consistent with the
prediction. Species with a greater proportion of their growth occurring
postnatally play more and have more complex play than do species with more of
their growth occurring prenatally.
PMID- 10689285
TI - Ontogeny of delay versus trace eyeblink conditioning in the rat.
AB - The ontogeny of delay versus trace eyeblink conditioning was examined in 19-, 23
, and 30-day-old rat pups. Pairings of a tone conditioned stimulus (CS) and
periocular shock unconditioned stimulus (US; 100-ms) were presented in one of
three conditioning paradigms: standard delay [380-ms CS, 280-ms interstimulus
interval (ISI)], trace (380-ms CS, 500-ms trace interval), or long-delay (980-ms
CS, 880-ms ISI). The results of two experiments indicated that standard delay
conditioning emerged between 19 and 23 days of age whereas trace and long-delay
eyeblink conditioning emerged more slowly from postnatal Days 19 to 30. Because
the acquisition profile for long-delay paralleled that of trace and not standard
delay, it appears that the relative deficits in the emergence of trace eyeblink
conditioning during development reflect difficulty in forming associations over
long ISIs rather than the short-term memory demands of the trace conditioning
paradigm.
PMID- 10689286
TI - The development of inhibitory control in preschool children: effects of
"executive skills" training.
AB - As one of several processes involved in the executive functioning of the
cognitive system, inhibitory control plays a significant role in determining how
various mental processes work together in the successful performance of a task.
Studies of response inhibition have shown that although 3-year-old children have
the cognitive capacity to learn the rules required for response control,
indicated by the correct verbal response, developmental constraints prevent them
from withholding the correct response (Bell & Livesey, 1985; Livesey & Morgan,
1991). Some argue that these abulic dissociations are relative to children's
ability to reflect on the rules required for response control (Zelazo, Reznick, &
Pinon, 1995). The current study showed that repeated exposure to tasks
facilitating the acquisition of increasingly complex rule structures could
improve inhibitory control (as measured by a go/no-go discrimination learning
task), even in children aged 3 years. These tasks included a variant of Diamond
and Boyer's (1989) modified version of the Wisconsin Card Sort Task and a
simplification of the change paradigm (Logan & Burkell, 1986). It is argued that
experience with these tasks increased the acquisition of complex rules by placing
demands on executive processes. This includes response control and other
executive functions, such as representational flexibility, the ability to
maintain information in working memory, the selective control of attention, and
proficiency at error correction. The role of experiential variables in the
development of inhibitory control is discussed in terms of the interaction
between neural development and appropriate executive task experience in the early
years.
PMID- 10689287
TI - Facile entry to (-)-(R)- and (+)-(S)-mexiletine.
AB - The title compounds, 1a and 1b, have been synthesized in a three-step sequence
starting from (-)-(S) and (+)-(R)-propylene oxide, respectively, in acceptable
overall yields. The enantiomeric excess values for 1a and 1b were 96% and 93%
respectively, as assessed by HPLC analysis on a chiral stationary phase of the
corresponding N-acetyl derivatives. The synthetic route herein presented may
represent a facile entry to highly enriched mexiletine enantiomers, alternative
to those previously reported in the literature.
PMID- 10689288
TI - Mechanisms of retention of pyrrolidinyl norephedrine on immobilized alpha(1)-acid
glycoprotein.
AB - The HPLC separation of the R,S and S,R enantiomers of pyrrolidinyl norephedrine
on immobilized alpha-1 glycoprotein (AGP) was investigated. Conditions for the
separation were varied using a premixed mobile phase containing an ammonium
phosphate buffer and an organic modifier. The influence of mobile phase pH, ionic
strength, organic modifier composition, modifier type, and temperature on the
chiral selectivity and retention were investigated. The presented data
demonstrate that independent phenomena govern the enantioselectivity and
retention. Retention is a function of both ion exchange equilibria and
hydrophobic adsorption. Thermodynamic data derived from van't Hoff plots
illustrates that while enantioselectivity is also enthalpically driven, the
magnitude of the enthalpy term is governed by pH. Enantioselectivity has little
dependence on ionic strength. Hydrophobic interactions appear to foster hydrogen
bonding interactions; the two appear to be mutually responsible for chiral
selectivity. The chiral selectivity decreases as the pH is decreased and
increases with mobile phase buffer strength.
PMID- 10689289
TI - Parity violation and the evolution of biomolecular homochirality.
AB - Parity violation at the level of terrestrial biopolymers, as seen in proteins,
DNAs, and RNAs, and parity violation at the level of nuclear processes, as
evident in longitudinally polarized beta-particles and parity-violating energy
differences (PVEDs), are discussed and their fundamental importances are
emphasized. Attempts to find a causal connection between the unique homochirality
of biopolymers and parity violation at the nuclear level, and speculations that
the former is a consequence of the latter, are reviewed. Consideration of all
lines of evidence leads to the conclusion that there is no substantiation for
such a causal connection, and that the two levels of parity violation are
entirely independent of each other.
PMID- 10689290
TI - Base-catalyzed epimerization of the butenolide in annonaceous acetogenins.
AB - The elusive epimerization process in the chiral butenolide moiety of Annonaceous
acetogenins was examined under several sets of conditions commonly used for
elimination leading to the alpha, beta-unsaturated lactone and the results
provide practical guidance in choosing elimination conditions.
PMID- 10689291
TI - On the calculation of Gibbs energy corresponding to enantioselective interactions
at a direct HRGC separation of enantiomers.
AB - A novel procedure is proposed for the calculation of Gibbs energy corresponding
to enantiospecific interactions of 2-(2, 4-dinitrophenoxy)-, 2-phenoxy-, and 2
halogen-n-pentane enantiomers with a beta-cyclodextrin (ChirasilDex) stationary
phase under gas chromatographic conditions. This energy is calculated from
retention data as a difference between the Gibbs energy of an enantiomer and its
corresponding achiral congener. The procedure for the determination of 2-(2,4
dinitrophenoxy)-, 2-phenoxy- and 2-halogen- n-pentane achiral congener retention
data is discussed in detail.
PMID- 10689292
TI - Determination of the absolute configuration of (-)-(3R)-O-beta-D
glucopyranosyloxy-5-phenylpentanoic acid from Polygonum salicifolium.
AB - The absolute configuration of the title compound has been determined after its
enzymatic hydrolysis to 3-hydroxy-5-phenylpentanoic acid, esterification, and
identification of the enantiomerically pure methyl (3R)-hydroxy-5
phenylpentanoate by HPLC on Chiralcel(R)OD-H. For reasons of inconsistent
literature data, enantioselective reductions of methyl 3-oxo-5-phenylpentanoate
have been reinspected and the stereochemical outcome unequivocally confirmed by
both chiroptical and HPLC retention data.
PMID- 10689293
TI - Synthesis of both enantiomers of 4-vinyl oxazolidin-2-one from a single
precursor: D-isoascorbic acid.
AB - A convenient synthesis of (S)- and (R)-4-vinyl oxazolidin-2-one 1 and 2 from the
same inexpensive starting material, D-isoascorbic acid, is described. The title
compounds were obtained in 44% and 38% yield, respectively, by operationally
simple steps. This approach is a suitable alternative to the literature methods
and enhances the synthetic utility of these intermediates. Inc.
PMID- 10689294
TI - Chiral photogeneration using perfluorocyclopentene-derived photochromes.
AB - A new type of perfluorocyclopentenes which contain an optically active group at
the 2-position of the thiophene ring were synthesized. Irradiation with UV light
afforded the cyclized diastereoisomers in ratios dependent on solvent polarity
and temperature.
PMID- 10689295
TI - Nefopam enantiomers: preclinical pharmacology/toxicology and pharmacokinetic
characteristics in healthy subjects after intravenous administration.
AB - Nefopam (NEF) is a potent analgesic compound administered as a racemic mixture.
Previous in vitro and in vivo studies with nefopam enantiomers have shown that
(+)nefopam [(+)NEF] is substantially more potent than (-)nefopam [(-)NEF].
Differences between enantiomers have also been suggested in metabolic studies in
vitro. The impact of these differences in vivo is not known because there is
little or no information on the relative plasma concentrations of the enantiomers
or on their kinetics. In this study, individual enantiomers of nefopam were
synthesized and examined for acute toxicity in male and female rats and mice.
Pharmacologic properties of enantiomers were examined using in vitro binding
assays and antinociceptive tests in rats and mice. Additionally, a
pharmacokinetic study was conducted in human volunteers. Subjects were
administered 20 mg nefopam as Acupan(R) either as a 5- or 20-min intravenous
infusion. In a control phase, subjects were administered only vehicle. Blood
samples were collected through the following 24 h. Plasma samples were analyzed
for individual enantiomers using a chiral assay developed for this purpose. The
pharmacologic differences of previous studies were confirmed in receptor binding
assays and in the hot plate and the formalin tests in mice. Neither enantiomer
demonstrated substantial activity in the tail flick test in rats. No significant
differences were revealed between LD(50) values of nefopam enantiomers after oral
or intravenous administration in male and female rats or mice. There were no
significant differences in AUC(0-infinity), C(max), or half-life between
enantiomers following intravenous administration. Based on these findings, there
is currently no compelling rationale to justify administering or monitoring
individual enantiomers.
PMID- 10689296
TI - Tumor necrosis factor: a master-regulator of leukocyte movement.
PMID- 10689297
TI - The emerging role of IL-15 in NK-cell development.
PMID- 10689298
TI - Microchimerism in human diseases.
PMID- 10689299
TI - Antigen processing and presentation by intestinal epithelial cells - polarity and
complexity.
AB - The mechanisms by which gut-associated lymphoid tissue (GALT) maintains a balance
between oral tolerance and active immune response in the face of exposure to high
antigen concentrations remains a central question in mucosal immunity. Here,
Robert Hershberg and colleagues discuss the evidence that human intestinal
epithelial cells function as antigen-presenting cells (APCs) capable of
regulating T-cell responses in the intestinal mucosa
PMID- 10689300
TI - Heat shock proteins, tumor immunogenicity and antigen presentation: an integrated
view.
AB - A broad range of studies has established that heat shock proteins (Hsps)
potentially play a role in tumor immunosurveillance. Here, Andrew Wells and
Miroslav Malkovsky highlight recent data that demonstrate a causal relationship
between the expression of Hsps and tumor immunogenicity, and suggest several
mechanisms by which Hsps might influence the capacity of a tumor to induce an
immune response.
PMID- 10689301
TI - The brain and thymus have much in common: a functional analysis of their
microenvironments.
AB - Research into the neural and immune systems has begun to converge. Since the
first reports that interleukins play important roles in both systems and that
lymphocytes secrete neuronal factors, scientists have been surprised by the ever
increasing list of interactions. Here, Rolf Mentlein and Marion Kendall examine
the major supporting cells of the brain and thymus - astrocytes and thymic
epithelial cells - the similar neuroectodermal origin of which could explain such
fundamental analogies.
PMID- 10689302
TI - Regulation of T-cell responses by CNS antigen-presenting cells: different roles
for microglia and astrocytes.
AB - Analysis of the mechanisms underlying CNS immune surveillance and immunopathology
have provided new insights into the intracerebral regulation of immune responses.
Here, Francesca Aloisi, Francesco Ria and Luciano Adorini review the role of CNS
antigen presenting cells and focus on the control of Th1 and Th2 responses by
microglia and astrocytes.
PMID- 10689303
TI - Tyrosine kinase SYK: essential functions for immunoreceptor signalling.
AB - The tyrosine kinase SYK plays critical roles in signalling through immune
receptors. Gene-targeting studies have identified the cell types that require SYK
for development and function, and the receptors that use SYK as well as their
downstream signalling effectors. There is also evidence of a role for SYK in non
immune cells and in the maintenance of vascular integrity.
PMID- 10689304
TI - Counting antigens using antibodies.
PMID- 10689305
TI - Allergenicity of grass and oil seed rape pollen.
PMID- 10689306
TI - Reply to jones et al
PMID- 10689307
TI - Gene therapy: a rocky start to the new millennium
PMID- 10689308
TI - New predictive test for high blood pressure.
PMID- 10689310
TI - New NIDDK head predicts greater emphasis on genetics.
PMID- 10689309
TI - Ambitious plans to make sense of signalling.
PMID- 10689311
TI - Australia faces biomedical brain drain.
PMID- 10689313
TI - How does HIV cause AIDS? The homing theory.
AB - The mechanism by which HIV causes depletion of CD4+ T cells in infected
individuals remains unknown. Numerous theories have been proposed, but none can
fully explain all of the events observed to occur in patients. Recent studies
have shown that HIV binding to resting CD4+ T cells upregulates L-selectin,
causing the cells to home from the blood into lymph nodes at an enhanced rate. It
is possible that the disappearance of CD4+ T cells in the blood is actually the
result of them leaving the blood, which can help explain the loss of CD4+ T cells
in the blood occurring at a much faster rate than in lymphoid tissues.
Furthermore, secondary signals through homing receptors received during the
homing process induce many of these cells into apoptosis. These cells die in the
lymph nodes without producing HIV particles, which can explain the 'bystander
effect' observed in the lymph nodes of HIV infected individuals. If this scenario
occurs in HIV+ patients, it might explain many of the clinical observations.
PMID- 10689314
TI - Knowing left from right: the molecular basis of laterality defects.
AB - The apparent symmetry of the vertebrate body conceals profound asymmetries in the
development and placement of internal organs. Asymmetric organ development is
controlled in part by genes expressed asymmetrically in the early embryo, and
alterations in the activities of these genes can result in severe defects during
organogenesis. Recently, data from different vertebrates have allowed researchers
to put forward a model of genetic interactions that explains how asymmetric
patterns of gene expression in the early embryo are translated into spatial
patterns of asymmetric organ development. This model helps us to understand the
molecular basis of a number of congenital malformations in humans.
PMID- 10689315
TI - Synthetic surfactants to treat neonatal lung disease.
AB - Pulmonary surfactant is a complex of surface-active lipids mixed with specific
proteins. Two of these, SP-B and SP-C, are essential for adsorption of surfactant
lipids to the air-liquid interfaces of the lungs and, hence, are also essential
for alveolar stability and effective gas exchange. Surfactant substitutes must
contain at least one of these proteins (or analogues of them) to be optimally
effective when administered into the airways of babies with surfactant deficiency
or dysfunction. This review describes how an increased understanding of the
properties of surfactant proteins has led to the development of improved
synthetic surfactants with the potential to treat a wide range of respiratory
disorders.
PMID- 10689316
TI - Superantigens - powerful modifiers of the immune system.
AB - Superantigens are powerful microbial toxins that activate the immune system by
binding to class II major histocompatibility complex and T-cell receptor
molecules. They cause a number of diseases characterized by fever and shock and
are important virulence factors for two human commensal organisms, Staphylococcus
aureus and Streptococcus pyogenes, as well as for some viruses. Their mode of
action and variation around the common theme of over-stimulating T cells,
provides a rich insight into the constant battle between microbes and the immune
system.
PMID- 10689317
TI - Animal models of stroke.
PMID- 10689318
TI - Medical and veterinary malacology in Africa.
PMID- 10689319
TI - Biochemistry of Plasmodium on the Web.
PMID- 10689321
TI - Health Information for International Travel 1999-2000.
PMID- 10689320
TI - Malaria Research and Reference Reagent Resource Center.
PMID- 10689322
TI - Ascaris haemoglobin: new tricks for an old protein.
PMID- 10689323
TI - Insecticide products: treatment of mosquito nets at home.
PMID- 10689325
TI - Functional Websites for Parasite Genome Projects.
PMID- 10689324
TI - Leishmaniasis, HIV and Oral Treatments on the Web.
PMID- 10689326
TI - Plasmodium falciparum Genome Update.
PMID- 10689327
TI - Do eosinophils have a role in the killing of helminth parasites?
AB - Eosinophils have been shown to be potent effector cells for the killing of
helminth parasites in in vitro cultures. However, an in vivo role for eosinophils
has been more difficult to establish. Early data showed close associations
between eosinophils and damaged or dead parasites in histological sections, and
significant correlations between resistance to parasites and the capacity to
induce eosinophilia after infection. However, more recent studies, using mice
that have reduced or increased eosinophil levels through targeting of the
eosinophil-specific cytokine interleukin 5, have not unanimously supported an in
vivo role for eosinophils in resistance to parasites. Here, Els Meeusen and Adam
Balic review these studies and suggest a major role for the innate immune
response in unnatural mouse-parasite models to explain some of the findings. They
conclude that the data so far are consistent with a role for eosinophils in the
killing of infective larval stages, but not adults, of most helminth parasites.
PMID- 10689328
TI - Commitment to gametocytogenesis in Plasmodium falciparum.
AB - To achieve transmission, a subpopulation of asexually dividing bloodstream forms
of the human malaria parasite Plasmodium falciparum withdraws from the cell cycle
to develop into gametocytes - cells specialized for sexual reproduction and
invasion of the mosquito vector. For natural selection to maximize transmission
to new hosts, a balance must have evolved between asexual replication and sexual
differentiation. Here, Mike Dyer and Karen Day consider observations on the
process of commitment to gametocytogenesis and use this information as the
framework for a model that begins to explain the control of the dynamics between
asexual and sexual development.
PMID- 10689329
TI - The kidney form of Trypanosoma musculi: A distinct stage in the life cycle?
AB - Trypanosoma musculi is a parasite specific to mice, which resides in the blood
and lacks intracellular stages. After immune clearance of the flagellates from
the general circulation, mice are resistant to reinfection. Yet, long after
parasites are no longer detected in the peripheral blood, they persist in the
vasa recta of the kidneys and it has been proposed that this is an
immunologically privileged site for T. musculi. This relationship provides a
useful model for studies of latent or chronic infections in immune hosts. Here,
Fernando Monroy and Donald Dusanic consider the immune responses of mice to T.
musculi and compare characteristics of the parasites from the vasa recta (kidney
forms, KFs) of mice with latent infections to trypanosomes from the peripheral
blood (bloodstream forms, BSFs) of animals during active infections. They
consider how KFs evade immune destruction and suggest that these sequestered
parasites represent a distinct stage in the life cycle.
PMID- 10689330
TI - Progress in the serodiagnosis of Neospora caninum infections of cattle.
AB - Neospora caninum is an apicomplexan protozoan that has become the focus of
significant research attention worldwide. This organism infects a range of host
species, including dogs, from which it was originally reported in 1984, but it is
most important as a major cause of bovine abortion. As a result of the global
importance of N. caninum, researchers have developed a number of serological
tests to investigate the epidemiology of infection and disease. In this article,
Robert Atkinson, Peter Harper, Michael Reichel and John Ellis consider progress
made in the serodiagnosis of N. caninum.
PMID- 10689331
TI - Tsetse--A haven for microorganisms.
AB - Arthropods are involved in the transmission of parasitic and viral agents that
cause devastating diseases in animals and plants. Effective control strategies
for many of these diseases still rely on the elimination or reduction of vector
insect populations. In addition to these pathogenic organisms, arthropods are
rich in microbes that are symbiotic in their associations and are often necessary
for the fecundity and viability of their hosts. Because the viability of the host
often depends on these obligate symbionts, and because these organisms often live
in close proximity to disease-causing pathogens, they have been of interest to
applied biologists as a potential means to genetically manipulate populations of
pest species. As knowledge on these symbiotic associations accumulates from
distantly related insect taxa, conserved mechanisms for their transmission and
evolutionary histories are beginning to emerge. Here, Serap Aksoy summarizes
current knowledge on the functional and evolutionary biology of the multiple
symbionts harbored in the medically and agriculturally important insect group,
tsetse, and their potential role in the control of trypanosomiasis.
PMID- 10689332
TI - Should DDT be banned by international treaty?
AB - The insecticide DDT has been an effective and affordable means of malaria control
in many countries, but pressure for its use to be banned is mounting. Here, Chris
Curtis and Jo Lines take a critical look at evidence that links house spraying by
DDT with harm to the environment and human health, and stress the need for
resources for alternatives to DDT to be made available to countries that would be
affected by a DDT ban.
PMID- 10689333
TI - The prophylactic effects of artemether against Schistosoma japonicum infections.
AB - The fight against schistosomiasis in China has been very effective in reducing
the number of infections across the country. However, the drug of choice,
praziquantel, has no prophylactic effect, which reduces its efficacy in high
transmission areas. This situation has prompted efforts to find prophylactic
compounds, the most promising of which is the drug artemether. In this article,
Xiao Shuhua, Mark Booth and Marcel Tanner review the results of laboratory tests
and field trials of artemether against schistosomiasis in China.
PMID- 10689334
TI - Identification of parasitic genes by computational methods.
AB - A number of parasite genome projects are under way, and large amounts of
nucleotide sequence data are becoming available for analysis. There is an urgent
need for development of theoretical tools to analyze the genome data, including
identification of protein-coding sequences. The majority of the methods developed
to date require prior information about the genome before accurate predictions
can be made. Because such information is not available for many parasites, these
methods cannot be directly applied. In this article, Alok Bhattacharya and
colleagues describe some of the gene-prediction methods commonly in use, and a
new method, GeneScan, that they have developed for the analysis of parasite
genomes.
PMID- 10689335
TI - No NO production during human Toxoplasma infection.
PMID- 10689337
TI - Reply.
PMID- 10689336
TI - Why do malaria parasites sequester?
PMID- 10689338
TI - Toxoplasma gondii and Overdulve.
PMID- 10689339
TI - Chloroquine binds in the cofactor binding site of Plasmodium falciparum lactate
dehydrogenase--a response.
PMID- 10689340
TI - Reply.
PMID- 10689341
TI - Voices in my head.
PMID- 10689342
TI - Seeing in three dimensions: the neurophysiology of stereopsis.
AB - From the pair of 2-D images formed on the retinas, the brain is capable of
synthesizing a rich 3-D representation of our visual surroundings. The horizontal
separation of the two eyes gives rise to small positional differences, called
binocular disparities, between corresponding features in the two retinal images.
These disparities provide a powerful source of information about 3-D scene
structure, and alone are sufficient for depth perception. How do visual cortical
areas of the brain extract and process these small retinal disparities, and how
is this information transformed into non-retinal coordinates useful for guiding
action? Although neurons selective for binocular disparity have been found in
several visual areas, the brain circuits that give rise to stereoscopic vision
are not very well understood. I review recent electrophysiological studies that
address four issues: the encoding of disparity at the first stages of binocular
processing, the organization of disparity-selective neurons into topographic
maps, the contributions of specific visual areas to different stereoscopic tasks,
and the integration of binocular disparity and viewing-distance information to
yield egocentric distance. Some of these studies combine traditional
electrophysiology with psychophysical and computational approaches, and this
convergence promises substantial future gains in our understanding of
stereoscopic vision.
PMID- 10689343
TI - Dynamical approaches to cognitive science.
AB - Dynamical ideas are beginning to have a major impact on cognitive science, from
foundational debates to daily practice. In this article, I review three
contrasting examples of work in this area that address the lexical and
grammatical structure of language, Piaget's classic 'A-not-B' error, and active
categorical perception in an embodied, situated agent. From these three examples,
I then attempt to articulate the major differences between dynamical approaches
and more traditional symbolic and connectionist approaches. Although the three
models reviewed here vary considerably in their details, they share a focus on
the unfolding trajectory of a system's state and the internal and external forces
that shape this trajectory, rather than the representational content of its
constituent states or the underlying physical mechanisms that instantiate the
dynamics. In some work, this dynamical viewpoint is augmented with a situated and
embodied perspective on cognition, forming a promising unified theoretical
framework for cognitive science broadly construed.
PMID- 10689344
TI - Visually guided collision avoidance and collision achievement.
AB - To survive on today's highways, a driver must have highly developed skills in
visually guided collision avoidance. To play such games as cricket, tennis or
baseball demands accurate, precise and reliable collision achievement. This
review discusses evidence that some of these tasks are performed by predicting
where an object will be at some sharply defined instant, several hundred
milliseconds in the future, while other tasks are performed by utilizing the fact
that some of our motor actions change what we see in ways that obey lawful
relationships, and can therefore be learned. Several monocular and binocular
visual correlates of the direction of an object's motion relative to the
observer's head have been derived theoretically, along with visual correlates of
the time to collision with an approaching object. Although laboratory
psychophysics can identify putative neural mechanisms by showing which of the
known correlates are processed by the human visual system independently of other
visual information, it is only field research on, for example, driving, aviation
and sport that can show which visual cues are actually used in these activities.
This article reviews this research and describes a general psychophysically based
rational approach to the design of such field studies.
PMID- 10689345
TI - Retrieval processing and episodic memory.
AB - The emergence of brain imaging has had a major impact on research into the
cognitive and neural bases of human memory. An area in which this impact has been
particularly strong is retrieval processing - the processes engaged when
attempting to retrieve information during a memory test. Several different
classes of retrieval process - such as 'mode', 'effort' and 'success' - have been
invoked to account for findings from neuroimaging studies of episodic retrieval.
In this article we discuss how these different kinds of process, along with a
fourth kind associated with 'retrieval orientation', can be investigated in brain
imaging experiments. We then review studies of retrieval processing, and assess
how well their designs match up to our proposed criteria for dissociating the
neural correlates of different classes of retrieval process. We conclude that few
studies have used designs that permit these different kinds of process to be
independently identified, and that presently there is little evidence to indicate
which kinds of processing can be fractionated in terms of their neural
correlates.
PMID- 10689346
TI - The Turing Test: the first 50 years.
AB - The Turing Test, originally proposed as a simple operational definition of
intelligence, has now been with us for exactly half a century. It is safe to say
that no other single article in computer science, and few other articles in
science in general, have generated so much discussion. The present article
chronicles the comments and controversy surrounding Turing's classic article from
its publication to the present. The changing perception of the Turing Test over
the last 50 years has paralleled the changing attitudes in the scientific
community towards artificial intelligence: from the unbridled optimism of 1960s
to the current realization of the immense difficulties that still lie ahead. I
conclude with the prediction that the Turing Test will remain important, not only
as a landmark in the history of the development of intelligent machines, but also
with real relevance to future generations of people living in a world in which
the cognitive capacities of machines will be vastly greater than they are now.
PMID- 10689347
TI - Finding the genes that direct mammalian development : ENU mutagenesis in the
mouse.
AB - The genetic control of mammalian embryogenesis is not well understood. N-ethyl-N
nitrosourea (ENU) mutagenesis screens in the mouse provide a route to identify
more of the genes that are required for mammalian development. The
characterization of ENU-induced mutations can build on the resources provided by
the mouse and human genome projects to help define the tissue interactions and
signaling pathways that direct early mammalian development.
PMID- 10689348
TI - The cancer genome anatomy project: building an annotated gene index.
PMID- 10689349
TI - Protein-length distributions for the three domains of life.
PMID- 10689350
TI - Regulation of adjacent yeast genes.
PMID- 10689351
TI - Complex evolution of the inositol-1-phosphate synthase gene among archaea and
eubacteria.
PMID- 10689352
TI - Canine genetics comes of age.
AB - The dog, as human's favored companion, is unique among animal species in
providing new insights into human genetic disease. In this review, we will
discuss both the breed and the population structure of dogs and why that makes
canines amenable to genetic studies. We will review the current state of the map
and discuss the particular disease states in which canines stand to make the
greatest contribution to medical genetics.
PMID- 10689353
TI - Endoderm development: from patterning to organogenesis.
AB - Although the ectoderm and mesoderm have been the focus of intensive work in the
recent era of studies on the molecular control of vertebrate development, the
endoderm has received less attention. Because signaling must occur between germ
layers in order to achieve a properly organized body, our understanding of the
coordinated development of all organs requires a more thorough consideration of
the endoderm and its derivatives. This review focuses on present knowledge and
perspectives concerning endoderm patterning and organogenesis. Some of the
classical embryology of the endoderm is discussed and the progress and
deficiencies in cellular and molecular studies are noted.
PMID- 10689354
TI - Twins. Novel uses to study complex traits and genetic diseases.
AB - The challenge faced by research into the genetic basis of complex disease is to
identify genes of small relative effect against a background of substantial
genetic and environmental variation. This has focused interest on a classical
epidemiological design: the study of twins. Through their precise matching for
age, the common family environment and background environmental variation,
studying diseases in non-identical twins provides a means to enhance the power of
conventional strategies to detect genetic influence through linkage and
association. The unique matching of identical twins provides researchers with
ways to isolate the function of individual genes involved in disease together
with approaches to understanding how genes and the environment interact.
PMID- 10689355
TI - Circadian rhythms: new functions for old clock genes.
AB - The mechanisms of circadian clocks, which time daily events, are being
investigated by characterizing 'clock genes' that affect daily rhythms. The core
of the clock mechanism in Drosophila, Neurospora, mammals and cyanobacteria is
described by a transcription-translation feedback-loop model. However, problems
with this model could indicate that it is time to look at the functions of these
genes in a different light. Our a priori assumptions about the nature of
circadian clocks might have restricted our search for new mutants in ways that
prevent us from finding important clock genes.
PMID- 10689356
TI - Selective peptidomimetic blockers of autoantigen presentation: a novel
therapeutic approach to autoimmune disease.
PMID- 10689357
TI - Urotensin II: fish neuropeptide catches orphan receptor.
PMID- 10689358
TI - G-protein-coupled receptors: what limits high-affinity agonist binding?
PMID- 10689359
TI - Reply
PMID- 10689360
TI - Nematode genome sequence dramatically extends the nuclear receptor superfamily.
AB - Nuclear receptors represent a large class of ligand-activated transcriptional
regulators; about 70 members of this protein family have been cloned from
mammalian or insect species. Thus, it came as a great surprise when the recent
completion of the Caenorhabditis elegans genome revealed at least 228 genes for
nuclear receptors. Clearly, some of these receptors are homologues of known
receptors, but most lack homologues in other species. Whether these receptors
possess homologues in mammalian species is of great interest; if these do exist,
the size of the nuclear receptor superfamily could also expand dramatically in
humans.
PMID- 10689361
TI - How well can molecular modelling predict the crystal structure: the case of the
ligand-binding domain of glutamate receptors.
AB - The concept that the ligand-binding domain of vertebrate glutamate receptor
channels and bacterial periplasmic substrate-binding proteins (PBPs) share
similar three-dimensional (3D) structures has gained increasing support in recent
years. On the basis of a dual approach that included computer-assisted molecular
modelling and functional studies of site-specific mutants, theoretical 3D models
of this domain have been proposed. This article reviews to what extent these
models could predict the crystal structure of the ligand-binding domain of an
ionotropic glutamate receptor subunit recently determined at high resolution by X
ray diffraction studies.
PMID- 10689362
TI - Development of pharmacological agents for targeting neurotrophins and their
receptors.
AB - Neurotrophins comprise a family of protein growth factors that control the
survival, growth, and/or differentiation of neurons and several other cell
populations derived from the neuroectoderm. Neurotrophins and their receptors are
important targets for the therapy of human disease, with potential applications
ranging from the treatment of chronic or acute neurodegeneration to pain and
cancer. Neurotrophins have been used clinically but are poor pharmacological
agents. Consequently, approaches to develop pharmacological agents that target
neurotrophins, their receptors or neurotrophin signaling pathways have been
attempted.
PMID- 10689363
TI - Cell-penetrating peptides.
AB - The established view in cellular biology dictates that the cellular
internalization of hydrophilic macromolecules can only be achieved through the
classical endocytosis pathway. However, in the past five years several peptides
have been demonstrated to translocate across the plasma membrane of eukaryotic
cells by a seemingly energy-independent pathway. These peptides have been used
successfully for the intracellular delivery of macromolecules with molecular
weights several times greater than their own. Cellular delivery using these cell
penetrating peptides offers several advantages over conventional techniques
because it is efficient for a range of cell types, can be applied to cells en
masse and has a potential therapeutic application.
PMID- 10689364
TI - Protease-activated receptors: sentries for inflammation?
AB - Cell-surface protease-activated receptors (PARs) appear to have evolved to detect
extracellular enzymatically active serine proteases such as trypsin and thrombin.
The predominant location of PARs on endothelia and epithelia and the discovery of
enzymes such as trypsin within these tissues, together with the linkage of PARs
to cytoprotective pathways, provide new information on autocrine and paracrine
signalling within these critical barriers. In this article, the ways in which the
distribution and function of PARs could be harnessed by pharmacologists as novel
anti-inflammatory therapeutic strategies are discussed.
PMID- 10689365
TI - Galanin receptor subtypes.
AB - The neuropeptide galanin, which is widely expressed in brain and peripheral
tissues, exerts a broad range of physiological effects. Pharmacological studies
using peptide analogues have led to speculation about multiple galanin receptor
subtypes. Since 1994, a total of three G-protein-coupled receptor (GPCR) subtypes
for galanin have been cloned (GAL1, gal2 and gal3). Potent, selective antagonists
are yet to be found for any of the cloned receptors. Major challenges in this
field include linking the receptor clones with each of the known physiological
actions of galanin and evaluating the evidence for additional galanin receptor
subtypes.
PMID- 10689366
TI - [ [In Process Citation]
PMID- 10689367
TI - [Yellow fever].
PMID- 10689368
TI - [Species of Anopheles (Culicidae, Anophelinae) in a malaria-endemic area,
Maranhao, Brazil].
AB - INTRODUCTION: The study of the seasonal fluctuation, nocturnal activity, relative
abundance and the richness of Anopheles species in anthropic environment is
essential to the understanding of the their bioecology and to the surveillance
program of malaria control. METHODS: The Anopheles species were studied from 6
P.M. to 6 A.M., once a month, for one year, from October 1996 to September 1997,
in the municipal district of Raposa, of the Sao Luis island, Maranhao state. The
basic method was the capture of female specimens on human baits in peri and
intradomicile sites by means of aspiration tube and guided luminous focus.
RESULTS: A total of 1.407 specimens were collected and distributed as follow:
Anopheles aquasalis (82% of the sample), Anopheles galvaoi (10,2%), Anopheles
albitarsis (6,4%), Anopheles evansae, Anopheles nuneztovari, and Anopheles
triannulatus davisi (the last three represented together 1, 4%). The anophelines
occurred all year round, mainly in the rainy period, being more frequent in the
intra (75,3%) than in the peridomicile site (24,7%), showing a clear preference
to suck blood in the evening. CONCLUSION: The behavioural variation of Anopheles
shows that the different species are becoming adapted to closeness to human
habitations, in the rural zone of the Sao Luis island.
PMID- 10689369
TI - [Taste preference for sweets and caries prevalence in preschool children].
AB - OBJECTIVE: To assess the preference for sweetness among preschool children and
differences between less and more deprived groups. In addition, to assess whether
sweet taste preference was associated with presence of caries. METHODS: The
sample was composed by 572 preschool children aged between 4 and 6, distributed
in three day nurseries of varied socioeconomic background. Cross-sectional study
developed in two steps. Preference for sweetness was assessed using a modified
version of the Sweet Preference Inventory. The solutions varied in sugar
concentration from 0 to 1,17 molar (0 to 400 g / litre). The presence of caries
was assessed using the defs index. The socioeconomic status of the sample was
classified according to the origin of domicile. RESULTS: The variation in
preference for sweetness in our sample was too small. Most children preferred the
sweetest juice. This reduced the ability of this variable to explain variation in
caries prevalence. Despite this limitation, our results showed that socioeconomic
level influenced preference for sweetness, which in turn was associated with
caries prevalence. CONCLUSION: The socioeconomic status influence the sweetness
preference and this, in turn, is associated with the dental caries prevalence.
PMID- 10689370
TI - [Evaluating a support program for children victim of domestic violence].
AB - INTRODUCTION: Domestic violence against children has been a subject of concern to
many Brazilian institutions, though there are few studies about the services
offered to the community. The aim of this study is to evaluate administrative and
operational aspects of the SOS Crianca and provide insight to similar programs
with comparative data. METHODS: A cross-sectional study of 976 data sheets of
investigated cases until 1993 was conducted. Study variables were:
characteristics of the support program required, proceedings to investigate
reported cases, follow-up duration of reported cases, and referrals to other
institutions. RESULTS: Out of 976 data sheets analyzed, 587 involved domestic
violence against children: 38.7% cases of physical abuse, 27.7% of neglect, 26.3%
of psychological abuse and 7.3% of sexual abuse. Most of the complaints (32.5%)
came from family members of victimized children. The program's investigation
process took between 126 to 212 days. Each investigated case demanded an average
of 2.7 to 4.6 procedures. The majority of the cases (44.0%) were referred to a
law court. This study emphasizes the need of a computerized database for
optimizing the services provided and the victims' follow-up. It also suggests the
need of ongoing staff training and development of broader and stronger
connections to the social and health services.
PMID- 10689371
TI - [American cutaneous leishmaniasis in the State of Acre, Brazil].
AB - OBJECTIVE: Present a statistical survey of American Cutaneous Leishmaniasis (ACL)
in the State of Acre. METHODS: Data were obtained from the forms of the "Campaign
against Leishmaniasis", from January 1992 to December 1997. Descriptive
statistical analysis was applied. RESULTS: There were 2.557 registered cases. The
highest prevalence was found at the microregion of Brasileia (231.8 cases/10,000
inhab.). The predominant clinical form was cutaneous (84.05%). The disease
occurred mostly among males (71.02%). Half of the cases were among people with 24
years of age or younger. Most cases were people with rural occupations. 83.97% of
the cases were diagnosed by clinical examination. The longest period to seek
medical treatment was registered in the mesoregion of Jurua Valley (10.37 months)
CONCLUSION: The high number of cases suggests that it might be necessary to study
the psychosocial implications of the disease and identify factors contributing to
the delay in treatment.
PMID- 10689372
TI - [Mosquitoes potential vectors of canine heartworm in the Northeast Region from
Brazil].
AB - INTRODUCTION: In some coastal districts of Sao Luis, capital of the state of
Maranhao, Brazil, the prevalence of Dirofilaria immitis is more than 40% in house
dogs. Natural potential vectors, as found in other areas of Northeastern Brazil,
are unknown. The aim of this study was to identify probable vectors of the
disease. METHODS: Mosquito catches were performed at a coastal, district Olho
d'Agua, in S. Luis, to look for local potential vectors. Captures were carried
out monthly, from March 1996 to May 1997, outdoors, having a man and a dog as
baits. Mosquitoes were dissected for D. immitis larvae. RESULTS: A total of 1,738
mosquitoes belonging to 11 species were collected. Culex quinquefasciatus, the
only species collected every month, was more frequently in the dry season. It
accounted for 54.5% of the total, followed by Aedes albopictus (20. 3%), Ae.
scapularis (11%) and Ae. taeniorhynchus (11%). D. immitis larvae were detected in
0.1% of the Cx. quinquefasciatus dissected (L3 in the Malpighian tubules) and
0.5% of the Ae. taeniorhynchus (L2 in the Malpighian tubules). CONCLUSION: Ae.
taeniorhynchus and Cx. quinquefasciatus are considered natural potential vectors
of the canine heartworm in Sao Luis. The role of Cx. quinquefasciatus as primary
vector of D. immitis, however, needs further evaluation.
PMID- 10689373
TI - [Dengue fever: a post-epidemic sero-epidemiological survey in an urban area
setting at a northwestern county of Sao Paulo State, Brazil].
AB - OBJECTIVE: The objective of this study was to evaluate the real size of the
epidemics registered in the urban area of the county of Santa Barbara D'Oeste,
SP, Brazil, from April to June, 1995. The measurement of the epidemiological
validity of the official surveillance system criteria and its positive predicted
value were adopted as specific goals. METHODS: A sero-epidemiological survey was
carried out over a sample of 1,113 sera from citizens of Santa Barbara D'Oeste,
through a systematic random sampling of houses, five months after the end of the
epidemics. Infection rates were compared with the infestation indexes by Aedes
aegipty and the notified cases amongst the county sections. The importance of
submitting patients with clinical suspicion of dengue to laboratory tests was
discussed. RESULTS AND DISCUSSION: It was found that infection rates by dengue
virus varied in the same direction and proportion as the presence of Aedes
aegipty larvae reported by the "Breteau Index", as well as the number of cases
reported by the official notifiable diseases surveillance system during the
epidemics. A prevalence of 630 by 100 thousand inhabitants was found, a 15-fold
rate when compared to the laboratory positive sera from cases detected by the
surveillance system during the epidemics. A retrospective comparison with the
surveillance reports, using serological results as a gold standard, also showed
that the majority of dengue specific serum-positive individuals were not detected
during the epidemics, otherwise cases that did not present serological reaction
were notified exhibiting a low positive predictive value of clinical diagnosis
(15,6).
PMID- 10689374
TI - [Low prevalence of bodyweight-for-height deficit: comparison of stunned and no
stunned Brazilian children].
AB - OBJECTIVES: The aim of this study was to investigate the relationship between
abdominal circumference and weight-for-height in children. The average of 18
anthropometric and body proportionality indexes were compared among four groups
of children: stunted and non-stunted Brazilians, Peruvians and North-Americans.
METHODS: There were studied 386 children aged 6-59 months living in a poor
neighborhood in Pelotas, Brazil. Anthropometric measurements (weight, recumbent
length or height, sitting height or crown-rump length; head, chest, upper arm and
abdominal circumferences; triceps, biceps, subescapular and suprailiac skinfold
thickness; biacromial and biiliac breadths) were obtained. Muscle, fat, total
upper arm areas, leg length and body proportionality indexes were calculated.
RESULTS AND CONCLUSIONS: The study sample showed high levels of morbidity, low
parental educational levels, poor access to health services and poor housing
conditions. Stunted Brazilian children had lower means for most of the
anthropometric measurements when compared to non-stunted Brazilians and North
American children. However, stunted children showed larger abdominal, head and
thoracic circumference in relation to their stature than non-stunted children.
The low prevalence of weight-for-height among the children of this study is not a
result of excess of fat or muscle tissue, and may be partly explained by an
increase in head and trunk dimensions (including abdominal circumference)
relative to the child's stature.
PMID- 10689375
TI - [Referred morbidity and care seeking on mental disorders in childhood and
adolescence].
AB - INTRODUCTION: Determining the prevalence of mental disturbances in childhood and
adolescence gives us a better knowledge of their distribution in a given age
group and provide us data for planning, implementing and evaluating health care
programs. This survey was centered on complaints of "nervous problems" in a
population group ranging from 1 to 19 years old as a tool to measure mental
illness prevalence in that age group. METHODS: A group of 141 children and
teenagers with complaints of nervous problems participated in the study, drawn by
applying questionnaires from June, 1989 to July, 1990 to a sample of 3,158 people
in the age group 1-19 years old, living in the Southeast area of Grande Sao
Paulo. It was conducted an analysis of the nature of the complaints, their
referred reasons and behavior, age, and gender. RESULTS: The prevalence of
complaints of nervous problems was 4.7%. The older they were the more they
complained. It was noticed a male predominance in the younger group and female
preponderance in the group 14 years old or older. One in five tried to get any
help, and severity of their complaint was the most important predictor for that.
CONCLUSION: The prevalence was due to the population's ability to identify mental
illnesses and it also reflects the family understandings of these problems. As
only a few sought for health care, possible causes were identified and
intervention actions were proposed to satisfy the unattended needs.
PMID- 10689376
TI - [Mortality risk measure inequalities among workers in Southeast Brazil].
AB - INTRODUCTION: The main causes of illness and death in Brazil have been migrating
backwards into the younger population during the last few years, increasing
especially in the more productive age groups. Given the relationship between work
and health/disease process, the hypothesis to be considered is that this
phenomenon is partially due to the deterioration of workplace conditions. To
contribute to investigating this hypothesis, this study estimates mortality risk
indicators for the population of Botucatu, in the Southeast region of Brazil,
classified according to their occupation. METHODS: Standardized mortality
coefficient, standardized risk ratio, and years of potential life lost were
calculated for the inhabitants of Botucatu who died after their 10th birthday,
between January 1997 and March 1998, and classified according to their occupation
and main cause of death. Occupational and medical information was obtained by
interviewing families of the deceased and their doctors, and checking medical
files. RESULTS: The standardized mortality coefficient ranged from 0.6 to 39.9
deaths/1000 workers in different occupations. The years of potential life lost
ranged form 33 to 334 years/1000 workers. The ranking of causes of death varied
according to occupation and the mortality risk considered. CONCLUSION: The risk
measures analyzed showed a high heterogeneity when associated to occupation and
causes of death, which reflects the great social inequality existing in the
studied population.
PMID- 10689377
TI - [Functional aging and work conditions in forensic workers].
AB - OBJECTIVE: The objective of this study was to evaluate aging associated to work
conditions. METHOD: Eight hundred and seven forensic workers answered the
questionnaire "Work Ability Index - WAI". The ergonomic conditions were analysed
using a job analysis method - AET (Rohmert & Landau). RESULTS: The largest number
of employees were mainly submitted to cognitive demands at work. The most
reported diagnosed diseases were: musculoskeletal diseases (and lesions),
neurological (including emotional disturbances), respiratory, digestive, skin and
cardiovascular diseases. The analysis of the logistic regression models showed
that: female workers, those with longer time on the job and job title of
operational helper, increase the odds ratio to present low or moderate WAI.
DISCUSSION: The results point out the need to improve the working conditions. It
is suggested the implementation of Specialized Safety Engineering and
Occupational Medicine Service, as it is demanded by the Federal Law 6,514 of
1977.
PMID- 10689378
TI - [Using food frequency questionnaire in past dietary intake assessment].
AB - This paper aims to discuss which one is the best estimator of past diet: a
retrospective report or a recent diet recall. The analysis included 13 articles
published between 1984-1997 and selected from a MEDLINE search and from other
reviews on this subject. The selection criterion was the use of a food frequency
questionnaire (FFQ) in a validation study of retrospective report of dietary
intake in remote past. Literature review shows that even taking into account
misclassification, retrospective report of diet usually yields to a more reliable
estimate of past diet pattern than current report. Past diet recall was strongly
influenced by current intake and by diet patterns change. Analyzed investigations
indicate that agreement between original and retrospective report was higher
either for foods eaten rarely or frequently and lower for foods moderately
consumed. This review allows considering the FFQ as a valuable instrument when
studying the role of diet on the etiology of chronic diseases.
PMID- 10689379
TI - [First occurrence of Biomphalaria straminea in the South Goiano, Brazil].
AB - The objective of this note is to report the occurrence of the Biomphalaria
straminea in the county of Cachoeira Dourada in the south of Goias, and with that
enhance the knowledge about its geographical distribution in the state. More than
identify the species, the collection of thirty samples helped study and verify
the presence of cercariae, especially because they were found in a setting which
offers proper conditions to the development of a focal transmission site of
schistosomiasis.
PMID- 10689380
TI - [Availability of voluntary prenatal HIV screening in primary health centers].
AB - A summary of the main steps towards the implementation of anti-HIV testing for
pregnant women in the city is presented. Starting from August 1996, voluntary HIV
testing became available to pregnant women seen at primary health centers in
Ribeirao Preto, SP (Brazil), as part of the Prenatal Care Program. By the end of
1998, 68.3% of the 17,589 women seeking prenatal care had been tested, resulting
in a positivity rate of 0.76%.
PMID- 10689381
TI - [Isolation of rabies virus in Molossus ater in (Chiroptera: Molossidae)in Sao
Paulo State, Brazil].
AB - This is a report of rabies infection in insectivorous bat Molossus ater in the
city districts of Aracatuba, Penapolis and Sao Jose do Rio Preto, in Sao Paulo
state, Brazil. Fluorescent antibody test detected the virus in the brain and
isolation was obtained by intracerebral inoculation of mice with nervous tissue
and organs suspension. There was no contact with humans or other animals.
PMID- 10689382
TI - [Serological survey for American cutaneous leishmaniasis in stray dogs in the S.
Paulo State, Brazil].
AB - A serological survey was made in 973 stray dogs caught near green areas in S.
Paulo county by the indirect immunofluorescence test. No positive serum was
found, however autochthonous human cases of ACL that occurred in the county show
the circulation of the parasite in the environment. This fact, associated with
the existence of the vectors and the apparent absence of infected dogs in the
areas studied, suggest that stray dog plays an insignificant role in the spread
of the parasite. The cycle of the parasite in Sao Paulo county has been
maintained by wild animals, hence the dog would be an accidental host just as
humans.
PMID- 10689383
TI - Incorporation of ubiquitin into the rat brain mitochondria is accompanied by
increased proteolytic digestibility of MAO.
AB - Incubation of rat brain mitochondria with ubiquitin followed by mitochondria
sedimentation was accompanied by reduction of ubiquitin content in the
supernatant only when ATP was included into the incubation mixture. Subsequent
incubation of resedimented mitochondria revealed higher sensitivity to trypsin of
MAO-A in ubiquitin-incorporated mitochondria. In control mitochondria (initially
incubated with ATP) 0.5 mg/ml trypsin caused a decrease of MAO-A activity by 32.2
+/- 4.2%, whereas in ubiquitin-incorporated mitochondria (initially incubated
with ATP + ubiquitin) reduction of MAO-A activity was significantly higher (51.4
+/- 2.5%, p < 0.02). Activity of MAO-B was resistant to trypsinolysis and
incorporation of ubiquitin did not influence sensitivity of MAO-B to trypsin.
Although there is no direct evidence yet that mitochondrial MAO is a target for
ubiquitination the increased sensitivity to trypsinolysis of MAO-A suggests that
incorporation of ubiquitin into mitochondria may increase susceptibility of MAO
to certain proteases involved into degradation of these enzymes.
PMID- 10689384
TI - Presence of SSAO in human and bovine meninges and microvessels.
AB - In spite that SSAO enzyme is widely distributed in almost all tissues, specially
in vascularized ones, its presence in brain microvessels is still controversy.
Our results resolve this question showing that both human and bovine
cerebrovascular tissues do contain the SSAO enzyme. This was achieved
biochemically, using benzylamine and methylamine as substrates, and by immunoblot
analysis, using polyclonal antibodies anti-SSAO that recognized a 100 kDa single
band in tissue homogenates.
PMID- 10689385
TI - Advances in evidence-based information resources for clinical practice.
PMID- 10689386
TI - Tenets for physicians in the new millennium.
PMID- 10689387
TI - Polymorphic tachycardia after cardiac arrest.
PMID- 10689388
TI - A man with fever, rigors, and poor oral hygiene.
AB - A 62-year-old man presented to the emergency department with a one-week history
of subjective fever and rigors. He had had epigastric pain for three weeks, for
which he was taking ranitidine, and in the past two to three months had
experienced night sweats, a nonproductive cough, nausea, vomiting, and a 30-lb
weight loss. He denied dsypnea, chest pain, hematochezia, melena, or any change
in bowel habits.
PMID- 10689389
TI - Molecules of the brain.
AB - Progress against a range of brain disorders is being sustained by the use of
genetic research techniques to identify specific molecules involved in brain
disease, and by the realization that the identified molecules may disclose novel
therapeutic targets. Both strategies are illustrated by recent insights and
interventions in Alzheimer's disease and Parkinson's disease.
PMID- 10689390
TI - Management of rapidly progressive glomerulonephritis.
PMID- 10689391
TI - Cardiac syndrome X: an overview.
AB - Not all patients with angina have myocardial ischemia. A sizable minority--up to
30% of angina patients studied at tertiary referral centers--have normal coronary
angiograms. Such patients often undergo an expensive and extensive array of
testing and treatment. Yet the prognosis is generally good, and symptomatic
management may be effective.
PMID- 10689392
TI - Chronic leg ulcers: types and treatment.
AB - Disorders of the arteries, veins, or nerves, alone or in combination, can result
in leg ulcers. The presentation in these cases varies with the cause, which in
turn guides management. A differential diagnosis is critical, because treatment
that is essential for one type of ulcer may be contraindicated in another.
PMID- 10689393
TI - Improving management of type 2 diabetes mellitus: 6. Chromium.
PMID- 10689394
TI - Coping with change: 4. Clear definitions and creative solutions.
PMID- 10689395
TI - Nurses are not their sisters' keepers.
PMID- 10689397
TI - The enigmatic nursing workforce.
PMID- 10689396
TI - Climate, culture, context, or work environment? Organizational factors that
influence nursing practice.
PMID- 10689398
TI - Analysis of patient profile in predicting home care resource utilization and
outcomes.
AB - OBJECTIVES: The study identifies patient profile variables that explain variation
in resource utilization and outcomes for home healthcare. BACKGROUND: The
healthcare reform and the demand for quality patient care have increased the need
to identify key patient characteristics that can predict the use of resources and
outcomes; however, home healthcare industry currently lacks adequate information
collection to reflect these needs. This study explored both the resource use and
care outcomes for nursing administrators in monitoring quality, resource
distribution, and reimbursement policy decision making. METHOD: The conceptual
framework is based on Donabedian's quality care elements (structure, process, and
outcome) and Nursing Minimum Data Set. This is a retrospective descriptive study
design in which 244 patient records and data were obtained from a home healthcare
agency located in Washington, DC. A series of stepwise and discriminant analyses
was conducted for data analysis. RESULTS: The findings indicated that the total
number of nursing diagnoses and two specific nursing diagnoses (alteration in
mobility and knowledge deficit in i.v. therapy) were strong predictors of overall
resource use. Prognosis proved to be the strongest predictor of discharge
outcomes. CONCLUSIONS/IMPLICATIONS: The results indicated that data related to
nursing diagnoses and nursing interventions can provide valuable information in
predicting resource use. Prognosis made by nursing judgment was also sensitive in
predicting patient outcomes. These critical data elements should be included in
describing home health patient characteristics and related resource utilization
and care outcomes.
PMID- 10689399
TI - The impact of systems redesign on staff, patient, and financial outcomes.
AB - OBJECTIVES: The purpose of this study was to measure the impact of a change
initiative using the strategies of inpatient bed consolidation and patient
population reaggregation on staff, patient, and financial outcomes. BACKGROUND:
Bed consolidation and patient population reaggregation are extensively used
strategies in the hospital industry. However, the state of science as it relates
to these two strategies is limited, with no studies measuring the effect of bed
consolidation, patient reaggregation, or both in isolation of multiple other
concurrent care model changes. METHODS: An exploratory, single case, longitudinal
field study design with embedded levels of analysis was used for the study. The
impact associated with the reaggregation and consolidation of the acute inpatient
system of care was evaluated at the organization, the acute inpatient nursing
unit, and the individual nursing staff member levels. This article reports the
outcomes found at both the nursing unit level and the staff member level on three
general medicine nursing units. Baseline nursing unit-level data are reported
from fiscal year 1994-1995 and the first half of fiscal year 1995-1996 (July 1995
through December 1995); data from January 1996 through June 1996 reflect the
planning phase of the project. Outcomes related to the change process are
reported from the time period January 1996 through June 1997. Staff perceptions
of multiple variables were measured at five different data points over a 2-year
period. Both quantitative and qualitative data were collected. RESULTS: Unit
level cost and hours per patient day (HPPD) increased during or immediately after
the merger of major patient populations on two of the study units; no significant
variation was found in medication errors or patient falls. The quantitative and
qualitative data analysis of the nursing staff member surveys revealed a nursing
staff that was dissatisfied with many aspects of their job, worried about job
security, had low morale, and had many concerns about the quality of care
provided to patients. CONCLUSIONS: This study suggests that consolidation and
reaggregation strategies may cause an increase in costs and HPPDs, at least on a
short-term basis. Also, these strategies may have a significant effect on the
morale and job satisfaction of unit-level nursing. In light of these findings, on
going testing of the efficacy of consolidation and patient reaggregation
strategies in improving quality and cost outcomes is essential.
PMID- 10689400
TI - Patient-centered documentation: an effective and efficient use of clinical
information systems.
AB - After 2 years of experience with a basic computerized system for documenting
care, the nursing leaders in an inner city hospital undertook a redesign process
to create an effective and efficient system for documentation that also provided
data for monitoring care processes, patient outcomes, and staff performance. The
basic system was a source of frustration and dissatisfaction for nurses,
physicians, and managers. The redesigned system has exceeded the expectations of
staff and physicians and delighted managers. Managers can now access the clinical
data collected by the staff to create meaningful reports describing the patient
population, identifying patients needs, monitoring staff compliance with care
standards, and tracking improvements in care processes.
PMID- 10689401
TI - Assessment: the first step in creating a more integrated system-wide approach to
nursing practice.
AB - As complex healthcare systems are created, professional nurses in these systems
must address the integration of nursing practice. To facilitate the transition to
a more common system-wide approach to professional practice, leaders at one
health system began by conducting an assessment of their current reality of
nursing practice. The authors describe the assessment process, including the
staff survey questionnaire and recommendations to strengthen nursing practice and
make the transition to a more common system-wide approach to professional
practice.
PMID- 10689402
TI - Reducing the use of physical restraints in nursing homes. Regulatory harassment
or good medicine?
PMID- 10689403
TI - Validity of malingering signs questioned.
PMID- 10689404
TI - Another cause of anterior knee pain.
PMID- 10689405
TI - Need more power in your communication technology? Increasing bandwidth will
improve speed and expand options.
PMID- 10689406
TI - Generalized pruritus without primary lesions. Differential diagnosis and approach
to treatment.
AB - A 65-year-old man presented with recurrent generalized pruritus and excoriations
of many years' duration. He had been treated with antihistamines, topical
corticosteroids, and antibiotics for secondary wound infections, but improvement
was only temporary. He had also been hospitalized for leg ulcers complicated by
cellulitis. Examination revealed multiple oval and linear red papules and nodules
measuring 0.5 to 2 cm in diameter. Some of the lesions were eroded and had a
central crater and yellowish crust. The patient also had hypopigmented linear
scars localized to the posterior scalp, neck, upper back, chest, abdomen, arms,
and legs with sparing of the middle and lower back (figures 1 and 2). An ulcer
measuring 1.5 x 2 cm that was surrounded by indurated skin was present on the
medial aspect of his right ankle. The ulcer was partially covered by yellow
exudate. There was no evidence of cellulitis. Liver enzyme, serum creatinine, and
thyrotropin levels, as well as a chest roentgenogram, were normal. Wound cultures
for bacteria and fungi were nonsignificant. A punch biopsy from a representative
lesion showed an abrupt epidermal defect with sparse superficial lymphocytic
infiltrate in the dermis. The patient was admitted to the hospital to isolate him
from his home environment. He received a 10-day course of systemic cephalexin,
topical clobetasol propionate ointment for the affected skin areas, and oral
hydroxyzine for pruritus. Ultraviolet light therapy was instituted once daily and
was to continue for 2 months. His lesions had improved moderately by the time he
was discharged from the hospital. On follow-up 2 weeks later, his lesions were
flat and had resulted in hypopigmented scars. Three months later, however, he had
persistent, intense pruritus, and new excoriations had developed on his forearms
and back. He improved after receiving treatment with oral doxepin hydrochloride.
PMID- 10689407
TI - In-office diagnosis of exercise-induced asthma.
PMID- 10689408
TI - Hypertension in patients with diabetes. Why is aggressive treatment essential?
AB - Hypertension and diabetes are interrelated diseases. Alone, each condition is a
risk factor for cardiovascular disease and, together, they strongly predispose to
end-stage renal disease, coronary artery disease, and peripheral vascular and
cerebrovascular disease. Pharmacologic treatment of hypertension can
substantially reduce morbidity and mortality in diabetic patients with
hypertension, but adequate control of blood pressure is seldom achieved in a
clinical setting. More aggressive treatment is needed to improve the prognosis
for this over-expanding patient population.
PMID- 10689409
TI - Viral pneumonias. Infection in the immunocompromised host.
AB - Three herpesviruses--herpes simplex, varicella-zoster, and cytomegalovirus-
commonly cause respiratory tract infections in immunocompromised patients.
Adenoviruses and measles virus are also significant causes of respiratory disease
in this population. Diagnosis of herpesvirus infections is difficult because
these viruses can establish latency and are often shed intermittently in the
absence of invasive disease. A positive respiratory tract culture of
herpesviruses alone is not diagnostic of active invasive disease. Preventive
measures should focus on limiting the patient's exposure to active infection,
broad use of available vaccines in children and susceptible adults, and use of
hyperimmune globulin and chemoprophylaxis in high-risk patients. Adenovirus
pneumonia is diagnosed by viral culture and rapid antigen detection assays,
whereas measles pneumonia is often identifiable by the characteristic rash.
Treatment of either adenovirus or measles pneumonia is primarily supportive.
PMID- 10689410
TI - Non-Q wave myocardial infarction. Assessment and management of a unique and
diverse subset.
AB - Acute cardiac events involving coronary symptoms, elevated enzyme levels, and
electrocardiographic changes without the development of Q waves often result in
higher rates of reinfarction and unstable angina than do more severe myocardial
infarctions. The incidence of these non-Q wave events is on the rise, possibly
because of earlier detection and treatment of heart disease. Familiarity with the
characteristics and management of the condition, therefore, is more important
than ever.
PMID- 10689411
TI - Abnormal findings on liver function tests. Interpreting results to narrow the
diagnosis and establish a prognosis.
AB - Evaluating abnormal liver test results requires careful attention to the
corresponding clinical data obtained during history taking and physical
examination. Generally, it is helpful to separate liver tests into three
categories: tests that assess synthetic function, tests that assess
hepatocellular necrosis (hepatocellular enzymes), and tests that assess
cholestasis. The clinical setting together with the specific pattern of liver
function abnormalities can narrow differential diagnosis and provide a cost
effective approach to assessing patients and identifying those who need liver
biopsy.
PMID- 10689412
TI - Tests for acute and chronic viral hepatitis. Finding your way through the
alphabet soup of infection and superinfection.
AB - Because clinical signs are of little or no help for identifying various causes of
viral hepatitis, accurate diagnosis can only be achieved with serologic and
molecular testing. Knowledge of the strengths and limitations of these tests
allows rational use and interpretation of results. The findings have implications
for public health surveillance, estimating prognosis, and identifying candidates
for treatment.
PMID- 10689413
TI - Antiviral therapy for chronic hepatitis B and C. Which patients are likely to
benefit from which agents?
AB - As primary care physicians become increasingly involved in diagnosis and
treatment of patients with chronic viral hepatitis, an understanding of the
antiviral options available, their limitations, and their side effects takes on a
special importance. For chronic HBV infection, interferon alfa-2b requires only a
4-month course. However, it has adverse effects and contraindications and does
not produce a universal response. Another option for HBV infection is lamivudine,
which is administered orally and causes few side effects. However, relapse may
occur when treatment is discontinued, and mutant virus may emerge. For chronic
HCV infection, interferon alfa-2a, interferon alfa-2b, consensus interferon, and
interferon combined with ribavirin have been used. The combination alternative is
emerging as the method of choice in patients who do not have contraindications to
oral ribavirin. Adverse effects are common, and durability of response varies
according to HCV RNA level and genotype.
PMID- 10689414
TI - Genetic liver disease in adults. Early recognition of the three most common
causes.
AB - The most common clinically important genetic diseases leading to liver
dysfunction in adults are Wilson's disease, HHC, and alpha 1AT deficiency.
Advances in molecular biology have led to the identification and characterization
of the genetic defects in these conditions. Consequently, genetic testing for
disease-causing mutations is now available for most of these disorders. However,
it is important to understand the strengths and limitations of such testing.
Genetic testing is probably most helpful in HHC because of the high frequency of
the homozygous C282Y mutation among patients of northern European descent and the
relatively high penetrance of the mutation with regard to clinical expression.
Genetic testing is much less helpful in the other genetic liver diseases because
of the high number of possible mutations and variable clinical expression.
However, noninvasive phenotype-based screening tests and specific treatments are
available for most genetic liver diseases. Appropriate use of screening tests in
routine clinical practice can assist in early identification of genetic liver
diseases and prevent development of end-organ damage.
PMID- 10689415
TI - Side effects of antipsychotic drugs. Avoiding and minimizing their impact in
elderly patients.
AB - Antipsychotic drugs are very useful in treatment of psychosis and severe
agitation in the elderly. Their use for other behavioral problems is
contraindicated. Antipsychotics have many potential side effects (e.g., sedation,
cardiovascular effects, anticholinergic effects, incontinence, reduced appetite,
such motor disturbances as drug-induced parkinsonism, akathisia, dystonia, TD).
Prevention, by using the minimum dose and duration of treatment possible, is the
key to managing motor side effects. If prevention fails, drug-induced
parkinsonism and dystonia may improve with use of anticholinergics, and akathisia
may improve with use of benzodiazepines or low-dose propranolol. There is no
proven treatment for TD, which is most likely to be observed during dose
reduction or after discontinuation of antipsychotic drugs. Compared with older
agents, newer antipsychotic drugs are less likely to cause parkinsonism,
akathisia, and dystonia and may cause TD less often. More research is needed to
clarify use of the new drugs in the elderly.
PMID- 10689416
TI - Sexually transmitted diseases in women. Gonorrhea and syphilis.
AB - Gonorrhea has been declining since its 1975 peak. Risk factors include age 15 to
19 years, multiple or casual sexual contacts, sexual activity related to drug
use, and low socioeconomic status. Infection is usually mild but may be
asymptomatic. While no physical signs are specific to the gonococcus, pelvic
inflammatory disease is a common complication and cause of infertility and should
be treated if it is suspected. Diagnosis of gonorrhea is typically by culture.
Newer, more accurate tests are available but are more expensive. For treatment,
the CDC recommends only highly effective regimens. Patients need to refer recent
sexual partners for treatment and abstain from sexual intercourse until
completion of therapy and resolution of symptoms. The incidence of syphilis
appears to be declining in the United States, but it should be considered if an
ulcer is found in the genital region. If untreated, the disease progresses
through primary, secondary, latent, and tertiary phases, and systemic symptoms
can mimic other conditions. Positive standard screening tests should be confirmed
by fluorescent treponemal antibody absorption testing. Darkfield microscopy is
appropriate for diagnosis of an ulcer. The treatment of choice for all phases of
syphilis is a single dose of intramuscular benzathine penicillin. Other
components of therapy include partner notification and patient follow-up. The
spread of HIV is closely linked to STD transmission. Therefore, testing for HIV
is strongly encouraged when another STD has been diagnosed.
PMID- 10689417
TI - Evaluation of nursing home patients. A systematic approach can improve care.
AB - As the US population ages, the proportion of patients receiving long-term care is
increasing. To meet the challenge of providing quality care for these patients,
physicians need to be prepared to efficiently evaluate their needs and formulate
individualized care plans. In this article, Drs King and Lipsky discuss the
unique aspects of caring for nursing home patients, including the role of
patients' families in the overall plan. They present a practical, structured
approach to evaluation and follow-up care, which they have encapsulated into two
handy assessment forms.
PMID- 10689418
TI - The physician's role in directing long-term care. Understanding the rules is
important for protecting your patients and your practice.
AB - Meeting the healthcare needs of patients who require long-term care presents many
challenges, not the least of which are local and federal regulations, a
formidable bureaucracy, and confusing paperwork. Despite these obstacles, long
term care patients often are among those with the greatest need for well-trained
physicians and high-quality medical services. This article reviews elements of
long-term care, with an emphasis on how primary care physicians should order and
provide services.
PMID- 10689419
TI - A perplexing case of pruritic plaques. Bullous pemphigoid.
PMID- 10689420
TI - Shattering the myths about male infertility. Treatment of male factors may be
more successful and cost-effective than you think.
AB - Male factors play a role in up to half of subfertile couples, contrary to the
myth that male factors rarely play a role. In this article, Dr Sandlow counters
this and other myths about male infertility and suggests that primary care
physicians can increase a couple's chance of conceiving by evaluating for male as
well as female factors. This article will also help primary care physicians
provide appropriate education and treatment, as well as determine when to make a
referral to a male-infertility specialist.
PMID- 10689421
TI - Community-acquired pneumonia. Outpatient treatment of patients 16 years and
older. Institute for Clinical Systems Improvement.
PMID- 10689423
TI - The ABCs of hepatitis.
PMID- 10689422
TI - Fever without source in children. Recommendations for outpatient care in those up
to 3.
AB - It is the author's goal to reduce risk to a minimum in children with fever
without source at a reasonable cost with guidelines that are practical for office
based physicians. Recommendations are as follows: All febrile infants and
children up to 36 months of age who have toxic manifestations are to be
hospitalized for parenteral antibiotic therapy after an expeditious evaluation of
their condition that includes cultures of blood, urine, and cerebrospinal fluid.
All febrile infants 7 days of age or less should be hospitalized for empirical
antibiotic therapy after a complete evaluation for sepsis and meningitis has been
done. Some low-risk febrile infants 8 to 28 days of age who appear well may be
observed closely, either in hospital (with or without empirical antibiotic
therapy) or as outpatients if the physician believes that close follow-up is
ensured. Febrile infants 28 to 90 days of age should have an evaluation to
determine whether they are in a low-risk group. Those not meeting low-risk
criteria should be hospitalized for a complete "sepsis workup" and close
observation, with or without empirical antibiotic therapy. Those who are
considered low-risk can be treated as outpatients, as described, if close follow
up is ensured. No laboratory tests or antibiotics are needed in a child over 90
days of age who has a temperature of less than 39 degrees C (102.2 degrees F)
without identifiable source. A return visit is recommended if the child's fever
persists for more than 2 to 3 days or if the condition deteriorates. A child with
a fever of 39 degrees C or above can also be treated as an outpatient without
antibiotics if close follow-up is ensured. Otherwise, a WBC count or ANC should
be done. In those whose WBC count is 15,000/mm3 or more or whose ANC is 10,000
cells/mm3 or more, a blood culture should be done, and pending results, a single
injection of ceftriaxone, 50 mg/kg, should be given.
PMID- 10689424
TI - [Premolecular period of the postradiation remodelling of cells].
AB - Recovery of yeast cells after exposure to ionizing radiation was found in 1957.
During the first decade, i.e. in the "premolecular period" of studying the
phenomenon, its basic features were revealed: dependence on ploidy of cells, on
their energy exchange, on radiation LTE, and others. A mathematical model of
recovery was proposed; the damages causing death of irradiated haploid and
diploid cells were shown to be double strand breaks of DNA. The concepts of
universal biological importance of the cell property to repair genetic damages
were formulated.
PMID- 10689425
TI - [Dynamics of tritium content in flood-lands reservoirs of the Pripyat river and
cooling pond of the Chernobyl nuclear plant].
AB - Tritium content in water from natural and artificial reservoirs within 30-km
exclusion zone of the Chernobyl NPP has been determined. The increase of Tritium
activity in the involved water reserwous has been registered in May 1994 and
April 1995. As supposed the source of the increase, nuclear power plants,
equipped with WWER reactors and located in catchment area of Pripyat river.
PMID- 10689426
TI - [Assessment of lipid peroxidation and plasma membrane permeability for Ca2+ in
the red blood cells of cattle after the long term grazing on radioactively
contaminated territory].
AB - Ten years after the Chernobyl accident a physiological condition of cows was
examined on radioactivy contaminated territory of the Novozibkov district of the
Bryansk region. The long grazing of cattle on radioactivly contaminated territory
revealed the increase in permeability of plasmatic membrane of the red blood
cells to Ca2+ and the activation of process of lipid peroxidation. The
sensitivity of the red blood cells of cows to incubations in hypertonic
conditions was demonstrated.
PMID- 10689427
TI - [Biological effects in natural populations of small rodents in radiation
contaminated areas. The frequency of bone marrow polyploid cells of bank voles in
different years following Chernobyl accident].
AB - On the basis of the metaphase analysis results, the peculiarities of dynamics of
the genome mutation frequency (polyploid cells) were studied in bone marrow of
bank voles inhabiting the areas with different radiocontamination level due to
the Chernobyl accident (8-1526 kBq/m2 for 137Cs) in 1986-1991. Unexpectedly high
frequencies of polypoid cells exceeding the pre-accidental level by a factor of
10(1)-10(3) were recorded in all populations studied. Relationship between the
frequency of the parameter studied and the concentration of radionuclides
incorporated in animal carcasses was proved. A statistically significant rise in
the frequency of genome mutations with the time was revealed up to 1991, i.e.
approximately to 12th post-accidental animal generation.
PMID- 10689428
TI - [Features of action of low doses of gamma-radiation on yeast cells].
AB - Lethal effect of low doses and adaptive response to low doses of prolonged
irradiation were investigated in experiments on yeast cells. The phenomenon of
hypersensitivity at low dozes was not found in yeast cells at gamma-irradiation.
The adaptive response was observed after exposure to low doses of prolonged
irradiation, the degree of the reaction depends on a dose rate. The adaptive
reaction was kept for some time after the termination of adaptive irradiation
then the sensitivity of cells increased even in comparison with unirradiated
ones.
PMID- 10689429
TI - [Alteration of polymorphic systems of Centaurea scabiosa L. under chronic
irradiation].
AB - Isoenzyme and morphological polymorphism alteration in populations of perennial
grass Centaurea scabiosa L. (scaly cornflower) has been studied. These
populations exist on the territory of East Ural Radioactive Trace more than 40
years and are chronically exposed to beta-irradiation. Directional shift of
allele frequencies on the loci Per1, Pgi2, Sod1, Lap has been detected. The fact
of accumulating genetic load by chronically irradiated populations has been
demonstrated. Possible reasons of discovered alterations are discussed. The
analysis of the obtained data shows that the irradiated populations have greater
similarity with one another than with a control, but relation between genetic
distances and accumulated doses hasn't been revealed. The hypothesis is that an
extra factor--gene flow from a "clean" territory influences the genetic structure
of irradiated populations.
PMID- 10689430
TI - [DNA damage in cells exposed to ionizing radiation].
AB - Ionizing radiation induces variety of structural lesions in DNA of irradiated
organisms. Their formation depends largely on the degree of cell oxygenation, the
level of endogenous antioxidants, on DNA-protein complexes and compactization of
DNA in the chromatin and activity of DNA repair systems. All ionizing radiation
induced DNA lesions can arbitrarily be divided into two groups. Group 1 includes
singly damaged sites (single-sites): base modification, single-strand breaks,
alkaline-labile sites (including a basic sites). Group 2 contains: locally
multiply damaged sites (clustered lesions), double-strand breaks, intermolecular
cross-links. The yields of lesions of group 2 increases with high linear energy
transfer of radiation and these lesions play a dominant role in the radiation
death, formation of chromosome and gene mutations, cell transformation.
PMID- 10689431
TI - [Concentration of T3 and T4 in blood of non-irradiated and irradiated with
different doses rats fasted for two days beforehand].
AB - There were no changes in concentration of T3 and T4 in blood of the rats that
were irradiated with a dose of 0.5, 1, 2, 4 and 6 Gy in comparison with non
irradiated rats, if the animals were not fed for two days before decapitation.
This suggests that the effect of ionizing radiation on thyroid function is
mediated by anorexia syndrome. The decrease in concentration of T4 after exposure
to 8 Gy cannot be explained by postradiative anorexia and most likely is
connected with starting enterotoxemy in difficult cases of acute radiation
sickness.
PMID- 10689433
TI - [Adaptation to irradiation in vivo].
AB - The data about the increasing of radioresistance of cells and organism after the
acute, chronic and prolonged irradiation in vivo were presented. The possible
mechanisms of adaptation to irradiation connected with selection, stimulation of
proliferative activity, forming of protecting system (protected proteins,
antioxidant enzymes e.a.), activation of DNA repair and cAMP-, and Ca(2+)
dependent phosphorylation systems were observed. The conclusion about complex
mechanism of radiation adaptation was drawn.
PMID- 10689432
TI - [Effect of ionizing radiation on the structure and functional properties of the
basolateral membrane of small intestine enterocytes].
AB - The structural state and transport properties of basolateral membrane of rat
small intestine enterocytes after exposure to X-ray irradiation (0.5; 1.0 and 2.0
Gy) were studied. The substantional suppression of the active Ca(2+)-transport
process concomitant to versatile changes of the membrane structure involving the
surface sites and intramembrane protein-lipid complexes was revealed one day
after irradiation. Taking into account the early obtained data on apical membrane
functional disorders these results confirm that ionizing radiation in sublethal
doses induces the structure-function modification of enterocyte plasma membrane
affecting the function of the small intestine epithelial cells.
PMID- 10689434
TI - [The geterogenity of 137Cs and 90Sr distribution and dose loading on critical
tissues of main seedling root].
AB - It is shown, that the roots of plants concentrate 137Cs and 90Sr from water
solutions in different zones: 137Cs--mainly in a meristem zone, 90Sr--in a
stretching zone. The similar character of radionuclide distribution was
established regarding water and soil cultures. The real dose loading on critical
tissues of main root have appeared to be much higher than it was expected from
the assumption of uniform distribution of radionuclides in tissues.
PMID- 10689435
TI - [Mechanisms and models of 137Cs migration in soils].
AB - The most spread mechanisms and models of 137Cs migration in soil were considered
and the advantage of the models, which take into account the kinetics of sorption
desorption above the models with two components were presented.
PMID- 10689436
TI - [The analysis of coefficient of 137Cs transfer from soil into potato in
relationship with 137Cs content in soil and plant mineral feed].
AB - The soil-potato transfer factor for 137Cs (TF) was estimated by using results of
137Cs activity concentration measurements in 214 samples of soil and potato taken
at fields with various level of contamination with 137Cs. The relationships
between the coefficient TF and soil characteristics (acidity pH (KCl), content of
K2O, P2O5, CaO and MgO in soil) and soil contamination with 137Cs have been
analysed. The results show that the TF values tend to decrease with increasing
concentration of 137Cs, K2O, P2O5, and CaO in considered sod-podsolic sandyloam
soil. The regression function describing the TF dependence of 137Cs, K2O, P2O5,
and CaO content in soil has been derived.
PMID- 10689437
TI - [Plant reaction to elevated ultraviolet irradiation: potential impacts of
stratospheric ozone depletion].
AB - The ozone layer depletion evokes the increase of solar UV-B radiation intensity
and corresponding reductions of growth (height, leaf area, fresh and dry weight),
photosynthetic activity and flowering in higher plants. Competitive interactions
also may be altered indirectly by differential growth responses. The UV-B
sensitivity of plants varies both among species and among cultivars of a given
species. Photosynthetic activity may be reduced by direct effects on the
photosynthetic process or metabolic pathways, or indirectly through effects on
photosynthetic pigments or stomatal function. Plants may also respond by
accumulating UV-absorbing compounds in their outer tissue layers, which
presumably protect sensitive target from UV-damage. The key enzymes in the
biosynthetic pathways of these compounds are specifically induced by UV-B
irradiation via gene activation. The effects of UV-B radiation on plants can be
modified by prevailing microclimatic conditions. Plants tend to be less sensitive
to UV-B under drought or mineral deficiency, while sensitivity increases under
low levels of visible light. Prognoses of agricultural yield reduction and
economic loss for different scenarious of stratospheric ozone depletion are
presented.
PMID- 10689438
TI - [UV-induced changes of structural and functional properties of blood lactate
dehydrogenase isoenzymes in free state and in the presence of serotonin].
AB - Photoinduced changes of structural and functional properties of
lactatedehydrogenase isoenzymes from human erythrocytes in free state and in the
presence of serotonin have been studied by means of gel chromatography,
electrophoresis, IR-spectrophotometry and by the method of definition of
catalytic activity. UV-light influence induces photoinactivation of erythrocyte's
LDH, while its inhibitory effect intensifies with the increase of irradiation
dose. The complicated character of changes in electrophoretic mobility and
percentage content of isoenzymes LDH-1, LDH-2, LDH-3 under the influence of UV
rays testifies that the decrease of total enzyme activity of these isoforms in
connected with their different photosensitiveness and represents the result of
many-staged process which is characterized both by the consistent and parallel
proceeding of its individual photochemical reactions. A pronounced
photoprotective effect of serotonin towards the molecules of erythrocytic LDH
isoenzymes has been discovered. It seems to be caused by formation of enzyme-
biogenous amine complex affecting the secondary protein structure.
PMID- 10689439
TI - [Biological effects of the low-intensive laser of the near infra-red spectrum].
AB - The immediate and the remote effects of the total one-time uniform irradiation
with arsenid-hallium laser (wavelength 0.89 mu, pulse power 450 W, pulsed mode 80
3000 Hz) on the new-born Wistar rats have been examined. The complex of tests
illustrated the biotropical effects of used laser regimes. The stimulating or
braking of the animal's growth was observed in accodanse with the laser regime.
PMID- 10689440
TI - [The international conference on human protection from electromagnetic fields
hazard].
PMID- 10689441
TI - Mapping the human nervous system in health and disease.
PMID- 10689442
TI - Kugelberg Lecture. Principles and pitfalls of nerve conduction studies.
PMID- 10689443
TI - Lecture in honour of Professor Emeritus Fritz Buchthal. Acute and chronic
demyelinating polyneuropathy: an overview.
PMID- 10689444
TI - Utility of somatosensory evoked potentials (SEPs) in spinal cord lesions and
functional surgery of pain and spasticity.
PMID- 10689445
TI - Multimodal approaches in the evaluation of epilepsy patients for surgery.
PMID- 10689446
TI - Movement-related brain electrical activity.
PMID- 10689447
TI - New trends in magnetoencephalography.
PMID- 10689448
TI - Cognitive potentials and corticocortical connections in humans.
PMID- 10689449
TI - Motor cortex plasticity.
PMID- 10689450
TI - What makes a brain oscillation abnormal?
PMID- 10689451
TI - Electrophysiological and morphological changes in the peripheral nervous system
with ageing.
PMID- 10689452
TI - Clinical applications of cyclic alternating pattern.
PMID- 10689453
TI - Power spectral sleep EEG findings in patients with obstructive sleep apnea and
upper airway resistance syndromes.
PMID- 10689454
TI - Survey of inherited peripheral nerve diseases.
PMID- 10689455
TI - Interconnections between cortical areas revealed by transcranial magnetic
stimulation.
AB - The fact that TMS of cerebral cortex is associated with inhibitory as well as
excitatory properties is important because it makes it possible to investigate
interconnections between cortical areas and tracing these functional
interconnections by a noninvasive excitation or inhibition and temporary
interference with the flow of impulses in the cerebral cortex. An important tool
is thereby added to the analysis of higher cortical functions.
PMID- 10689456
TI - Isolation of late event-related components to checkerboard stimulation.
PMID- 10689457
TI - Continuous EEG monitoring in the intensive care unit.
PMID- 10689458
TI - Percutaneous stimulation of mechanoreceptors and peripheral neural transmission
in normal subjects and patients with hereditary ataxias.
PMID- 10689459
TI - Non-invasive pre-surgical evaluation with EEG/MEG source analysis.
PMID- 10689460
TI - Excitability of the motor cortex in amyotrophic lateral sclerosis.
PMID- 10689461
TI - Introducing priors in the EEG/MEG inverse problem.
PMID- 10689462
TI - Spinal mechanisms of spasticity.
PMID- 10689463
TI - Genotype-phenotype correlation in spinocerebellar ataxias (SCA).
PMID- 10689464
TI - Cortical visual processing.
PMID- 10689465
TI - Neuromagnetic recordings and magnetic brain stimulation in the evaluation of
sensorimotor hand area interhemispheric differences: normative, experimental and
patients' data.
PMID- 10689466
TI - Does the vestibulo-ocular reflex use the same pathways for functions in roll and
pitch planes?
PMID- 10689467
TI - Short and middle latency vestibular evoked potentials to angular and linear
acceleration.
PMID- 10689468
TI - Evoked potentials in sound localization: timing of activity along the auditory
pathway.
PMID- 10689469
TI - EEG band centroid modifications in HIV patients.
PMID- 10689470
TI - Genetic and antibody-mediated channelopathies at the neuromuscular junction.
PMID- 10689471
TI - Mechanisms involved in the propagation of interictal epileptiform discharges in
partial epilepsy.
PMID- 10689472
TI - P300 and Alzheimer's disease: oddball task difficulty and modality effects.
PMID- 10689473
TI - Value and limits of cardiovascular autonomic function tests.
PMID- 10689474
TI - Non-invasive assessment of motor unit properties with linear electrode arrays.
PMID- 10689475
TI - Electroencephalogram in metabolic encephalopathies.
PMID- 10689476
TI - Evoked potentials to painful laser stimulation.
PMID- 10689477
TI - Value and limits of expert systems in clinical neurophysiology: an integrated
'Avicennian' approach.
PMID- 10689478
TI - Congenital muscular dystrophies. A short review of the recent progresses.
PMID- 10689479
TI - Model-based delta plots beat power-based ones.
PMID- 10689480
TI - Can evoked potentials be useful in monitoring multiple sclerosis evolution?
PMID- 10689481
TI - Spinal reflex pathways transcend the scheme of an auxiliary or independent
system.
PMID- 10689482
TI - Characteristics of SEP from subthalamic nucleus in human.
PMID- 10689483
TI - Spinal reflex studies enable to analyze supraspinal dysfunctions.
PMID- 10689484
TI - Neurophysiological aspects of diagnosis in neuromuscular transmission defects--an
update.
PMID- 10689485
TI - Movement-related potentials and magnetic fields: new evidence for SMA activation
leading MI activation prior to voluntary movement.
PMID- 10689486
TI - Auditory information processing in comatose patients: EPs to synthesised
'musical' tones.
PMID- 10689487
TI - High-rate transcranial magnetic stimulation: influence on short-term-memory,
heart rate and blood pressure changes.
PMID- 10689488
TI - Muscle sonography.
PMID- 10689490
TI - MEG spontaneous activity in patients with memory disorders.
PMID- 10689489
TI - Diagnostic relevance of anti-neural antibodies in dysimmune neuropathies.
PMID- 10689491
TI - Inhibitory function in chronic focal epileptogenesis.
PMID- 10689492
TI - Do GABAergic circuitries play a critical role in the regulation of seizure
induced neuronal damage and synaptic reorganization in the rat hippocampus?
PMID- 10689493
TI - Antiepileptic drugs potentiating GABA.
PMID- 10689494
TI - Cognitive effects of GABAergic antiepileptic drugs.
PMID- 10689495
TI - Cognitive impairment in multiple sclerosis: a longitudinal study.
PMID- 10689496
TI - Event-related potentials in the assessment of cognitive function in multiple
sclerosis.
PMID- 10689497
TI - Electrophysiological investigations in multiple sclerosis dementia.
PMID- 10689498
TI - Mechanisms of action of intravenous immunoglobulin (IVIg) in autoimmune and
neuromuscular diseases.
PMID- 10689499
TI - Chronic inflammatory demyelinating polyneuropathy (CIDP).
PMID- 10689500
TI - IVIg in polymyositis and myasthenia gravis.
PMID- 10689501
TI - High-dose intravenous immunoglobulin in multifocal motor neuropathy.
PMID- 10689502
TI - Safety and tolerability of intravenous immunoglobulins.
PMID- 10689503
TI - Monitoring the natural history and results of therapeutic intervention in
diabetic neuropathy: clinical measures.
PMID- 10689504
TI - Diabetic neuropathy--the utility of nerve biopsy.
PMID- 10689505
TI - Nerve conduction study in diabetic polyneuropathy: multicenter analysis on
intertrial variability.
PMID- 10689506
TI - Autonomic tests in diabetic neuropathy.
PMID- 10689507
TI - The Italian multicentre study on the prevalence of distal symmetric
polyneuropathy: correlation between clinical variables and nerve conduction
parameters. Italian Diabetic Neuropathy Committee.
PMID- 10689508
TI - Utility of the skin biopsy method in studies of diabetic neuropathy.
PMID- 10689509
TI - Clinical measures of disease activity in multiple sclerosis.
PMID- 10689510
TI - Non-conventional MR techniques in monitoring MS activity and evolution.
PMID- 10689511
TI - Immunological surrogate markers of disease activity in multiple sclerosis.
PMID- 10689512
TI - Neurophysiological markers of relapse, remission and long-term recovery processes
in MS.
PMID- 10689513
TI - Monitoring temporal aspects of cortical information processing.
PMID- 10689514
TI - Neural bases of time estimation: a PET and ERP study.
PMID- 10689515
TI - [AINS (anesthesiology, intensive care, emergency medicine, pain therapy) 2000--a
look to the future].
PMID- 10689516
TI - [Management and methodological approaches for the assessment of emotional states
in anesthesiology].
AB - In anaesthesiology emotional states are of great importance. Reduction of anxiety
and sedation in the preoperative preparation as well as stress reduction and the
process of recovery are a challenge for anaesthetists as perioperative
physicians. As emotions have different dimensions of manifestation like
experience, expression, behaviour and somatic indicators, all these are needed to
describe emotions sufficiently. In a multidimensional approach for the measure of
emotional states, the different dimensions, their relationships and interactions
are taken into account. The methodological approaches to registration of emotions
in the anaesthesiological context are heterogeneous. In this summary the
possibilities are differentiated by the source of information. Self-rating by the
patient, rating by the observer, expression and behaviour and somatic indicators
are taken into consideration. Analysis of the methods for the assessment of
emotional states in anaesthesiological setting leads to the following
recommendations: The most sensitive source of information is the patient. The
rating scale used should be multidimensional and it should take specific as well
as unspecific emotional aspects into account. As there are enough rating scales
thoroughly developed and up to the demands of the classical test-theory, no ad
hoc developed scales should be used. The rating of the emotional state should be
supplemented by a rating of the physical state. The rating by the observer can be
a valuable addition. The agreement between observers and the reliability of the
method must be guaranteed. At presence there is no alternative in clinical
practice to simple autonomic parameters such as blood pressure and heart rate as
somatic indicators of emotion. Still it is important to consider the normal
values for the individual patient. It is necessary to develop and to evaluate
simple methods to register characteristics of expression in clinical context.
PMID- 10689517
TI - [Target controlled infusion (TCI)--status and clinical perspectives].
AB - The technique of target controlled infusion (TCI) has influenced the development
of intravenous anaesthesia substantially and opens the possibility of many new
and exciting applications in peri-operative anaesthetic care. The launch of
"Diprifusor" as the first commercially available TCI system for propofol was the
cornerstone of a successful research period within the last decade, which
evaluated the pharmacokinetic foundations of computer assisted intravenous drug
delivery. We are now in a period where TCI technology is becoming a part of
routine anaesthesia technique for the practitioner rather than a research tool
for specialists and enthusiasts. This review gives an update on the rational
pharmacokinetic basis of TCI development, the preliminary clinical experience
with the new technique, the performance and accuracy of TCI devices and potential
technical pitfalls in clinical routine. Besides clinical application in
anaesthesia with "Diprifusor" TCI, target controlled systems are expected to play
a significant role as research tools in the evaluation of drug interactions in
anaesthesia and in the development of novel control techniques for the
administration of sedative and analgesic drugs in the peri-operative period.
PMID- 10689518
TI - [Direct autotransfusion systems deliver blood of inadequate quality].
AB - OBJECTIVE: Systems for direct retransfusion of blood salvaged from the surgical
field and in drainage systems (direct autotransfusion) have been in use for many
years. The quality of the blood obtained with such systems, however, has not been
systemically assessed in a comparative manner. The aim of our study was the
analysis of the quality of the blood, obtained with three commercially available
direct autotransfusion systems (drainage systems with filters). METHODS: With
ethics committee approval and informed consent, 30 patients receiving knee
arthroplasty were randomly allocated to three groups. Each group of 10 patients
received treatment with one drainage system (Consta Vac, Solcotrans, Haem-o
Trans). In the salvaged blood, we measured cellular elements, variables of
coagulation and fibrinolysis, complement activation and cellular elements, both
before and after passage of the autotransfusion system. RESULTS: Analysis
revealed a low haematokrit (< 30%) and platelet count (< 80 Gpt/l). The salvaged
blood proved uncoagulable and defibrinised with no measurable clotting and
fibrinogen; clotting activity, fibrinolysis and complement reaction were grossly
induced (TAT, PAP and FDP high, C3 low). The blood was contaminated with cellular
debris reflected by concentration of enzymes usually confined to the
intracellular space (LDH, elastase, beta-thromboglobulin). CONCLUSION: The
systems/filters assessed in this study do not improve quality of blood drained
from the surgical field. Retransfusion of such blood can not be recommended.
PMID- 10689519
TI - [Practical realization of a patient-accompanying concept in anesthesia and
intensive care].
AB - Our current concept of stationary workplaces results in an interruption in
patient monitoring and treatment. Because transfers are invariably associated
with a reduction or interruption in the monitoring and treatment chain, an
endangerment to critically-ill patients, as well as a significant increase in the
mortality rates, can result. DESIGN: In the new construction of the Cardiac
Clinic, the previous concept of immobile anesthesia and intensive care
workstations has been completely abandoned. The complete treatment workstation,
including monitoring and fluid management, is set up on a bedside cart which
accompanies the patients uninterruptedly--from anesthesia administration, to the
operating room, to the ICU or recovery room, as well as during elective or
emergency interventions outside the ICU. Transport times and complications from
995 transports (ASA III and IV) were analysed and compared with 880 transports
with the conventional system. RESULTS: During all intrahospital transfers with
the mobile workplace, there were no complications resulting from faulty operation
or accidental adjustment of the perfusors, or from disconnecting the monitoring,
, respiration-, or infusion lines. On the whole, there were fewer cases of
circulatory instability during transport, since infusion treatment and medication
could be administered without interruption. All hemodynamic parameters were
recorded during transport, as were cardiac minute output and right- and left
atrial filling pressures. The mobile workplace system allows for the shortest
possible transport and exchange times--13.5 min, as compared to 42.5 min with the
conventional system. The reconnection of monitoring equipment with zeroing,
adjustment of the alarm limits, as well as exchanging perfusors and infusomats
before and after transport is eliminated entirely. CONCLUSION: This mobile
workplace, in which all components of the anesthesiological and intensive care
workstations are integrated, guarantees the highest possible level of patient
safety, since nothing has to be disconnected until the patient is transferred to
a normal-care ward. In addition to the improved ergonomic design of the nurse's
and doctor's workplace, substantial savings can also be made.
PMID- 10689520
TI - ["Is the Wurzburger pain drip an alternative to i.v. PCA?": contra].
PMID- 10689521
TI - ["Is the Wurzberger pain drip an alternative to i.v. PCA?": pro].
PMID- 10689522
TI - [Principles and role of nucleic acid amplification and modern microbiological
diagnosis].
AB - In the recent decade, molecular tests have provided tools for highly sensitive
and specific, culture-independent detection of infectious agents in clinical
specimens. The rapid development of new methods and among these mainly the
prototype method "polymerase chain reaction" (PCR) result in improved diagnostic
procedures. Since its original description, a lot of modifications and
advancements of PCR and alternative systems for in vitro amplification of nucleic
acids have been developed to meet various requirements for improved detection of
both DNA and RNA, quantification of the target molecules, and transfer from basic
clinical research into a routine technique for clinical laboratory diagnosis.
Since the purposes for which nucleic acid amplification methods should be used in
the diagnosis of infectious diseases are often still uncertain, an evaluation and
careful examination of the criteria for correct application of these techniques
is needed. This review focuses on the recent developments in amplification
procedures as well as on the use of these methods in the laboratory diagnosis of
infectious diseases. The methodological limitations, future needs and
perspectives are addressed.
PMID- 10689523
TI - [Intraoperative management of unexpected arterial hypotension during lumbar
diskectomy].
AB - An anesthesiological management is difficult in surgical procedures in which the
operative situs is not to be seen by the anesthesist. Therefore specific
knowledge of the operative procedure and related hazards are mandatory for
optimal anesthesiological care. By describing the anesthesiologic proceduces in
two lumbar discectomys, the specific problems in recognition and treatment of
severe injuries of retroperitoneal vascular structures are explained. In
addition, the differential diagnosis of intraoperative arterial hypotension is
described. The communication between all disciplines involved is mandatory,
especially in cases of severe complications. The management of such complications
can only be solved through in-time interdisciplinary cooperation of all involved
disciplines.
PMID- 10689524
TI - Why history is important for thoracic surgeons.
AB - There are numerous examples of lessons to be learned from acquaintance with
surgical history. Notwithstanding these considerations--the admonition to read
and think about history, the lessons learned from technical misadventures, and
the need to add humanistic practices to our scientific endeavors--the real reward
from our study of medical history lies in the pure job of being educated in one
more way. This implies understanding our contemporary position in the unrolling
course of medical history: from remote history through the enlightenment after
the reawakening from the dark ages, to the surgical spurt in the latter half of
the nineteenth century, and onward through the dramatic advances of our passing
millennium.
PMID- 10689526
TI - The history of surgery of empyema, thoracoplasty, Eloesser flap, and muscle flap
transposition.
AB - This article discusses the surgical history of empyema, thoracoplasty, the
Eloesser flap, and muscle flap transfer. Little has changed in the 2000 years
since the treatment of empyema was originally described by Hippocrates. The basic
concepts of drainage of the infected empyema and obliteration of the space by
allowing the lung to come up to the chest wall, taking the chest wall down to the
lung, or by using muscle flaps or antibiotic solution remain the stabilizing
forces in the treatment of postresection or postinfectious empyemas.
PMID- 10689525
TI - The history of thoracic surgical instruments and instrumentation.
AB - Thoracic surgical practice has evolved from the innovations of its pioneers.
Beginning with the stethoscope discovered by Laennec with his system of
auscultation, to the tools we use in the dissection and control of the hilum of
the lung for resection, our practice of thoracic surgery has been entwined with
the development of instruments and instrumentation. The development of strategies
to prevent death from the open pneumothorax began with manual control of the
mediastinum and progressed through differential pressure to, finally, the
technique of intubation and the methods of positive-pressure and insufflation
anesthesia. The instruments we place in our hands are not enough to define our
art. Entry into the chest would not be possible without the use of rib
retractors, rib shears, and even periosteal elevators. Finally, to the present
day of minimally invasive techniques and the application of thoracoscopy for
therapeutic purposes, we find the efforts of our predecessors well developed. For
the progression from the fear of the open pneumothorax to the present-day state
of the ease of thoracotomy for lung resection we are indebted to those who gave
so much of their time and, for some, their lives to death from tuberculosis, to
allow the advancement of our practice of surgery. These great people should be
remembered not only for their acceptance of novel ideas but also, more
importantly, for their lack of fear of testing them.
PMID- 10689527
TI - History of surgery for penetrating chest trauma.
AB - The military surgery experience of the past several centuries has been an
important determinant of the evolution of the clinical management of penetrating
thoracic trauma. The major management problems fall into two main categories:
acute, life-threatening conditions such as open pneumothorax and exsanguinating
hemorrhage, and chronic conditions such as clotted hemothorax, empyema, and
fibrothorax. Better treatment and prevention of the latter has greatly reduced
morbidity. Although hospital mortality has fallen by a factor of ten since the
middle of the nineteenth century, the total mortality caused by penetrating
thoracic trauma has undergone less change.
PMID- 10689528
TI - The history of ventilation in the evolution of thoracic surgery.
AB - The intrusion into the pleural space by surgeons was hindered for several hundred
years by the realization that there were major pathophysiological alterations in
ventilation and in circulation. The nature of this abnormality, although
described very early on in history, went unrecognized until the end of the
nineteenth century. The performance of thoracic surgery prior to that time and
the development of different modes of ventilatory support are testimony to the
intuition and inventiveness of the surgeons of that day. It is hard for the
modern thoracic surgeon to fully comprehend the challenges that faced the early
surgeon back when there was no such thing as positive pressure ventilation or
unilateral lung ventilation. This article traces the origins of ventilation in
man and their application to the development of thoracic surgery.
PMID- 10689529
TI - The evolution of the surgical treatment of lung cancer.
AB - The evolution of surgery for lung cancer is a story of discovery and innovation.
From the fortuitous lung resections of the fifteenth century to the sophisticated
operations of the twentieth century, surgeons have pursued the goal of bringing
technology and science to bear on the effort to cure lung malignancy.
Intrathoracic operations could not have developed without the advent of modern
anesthesia, described in detail in another section of this issue. Great courage
and insight were the hallmarks of those who first realized that surgical removal
of primary lung cancer could become a reality and who pursued this goal in the
face of discouraging results. The surgeons involved have worn many hats as
experimentalists, physiologists, anesthetists, and biologists to bring all their
knowledge and experience to bear on the surgical treatment of this disease. It is
not possible in a brief review to identify the many physicians and scientists who
contributed to the evolution of this treatment, but some of their stories have
been included to illustrate the ideas involving major events over the past seven
decades.
PMID- 10689530
TI - The history of lobectomy and segmentectomy including sleeve resection.
AB - The evolution of pulmonary lobectomy during the past six centuries is presented.
The anesthetic problems of an open thorax, the absence of antibiotics, and the
absence of radiology initially complicated thoracic surgery. Surgical pioneers
differed strongly on the best techniques for lobectomy. Concurrence in their
opinions evolved by the formation of a specialty group, meetings, and journals.
The recent techniques of segmentectomy and sleeve resection provide further
refinement of pulmonary resections.
PMID- 10689531
TI - History of resectional surgery for tuberculosis and other mycobacterial
infections.
AB - Resectional surgery for tuberculosis became increasingly common in the 1940s;
however, thoracoplasty remained the most popular treatment of choice until the
introduction of effective antituberculosis agents. With the development of
rifampin in 1966, surgery was seldom needed except for the occasional massive
hemoptysis, bronchial stenosis bronchopleural fistula, or to rule out cancer.
With the rise of MDR-TB and the increasing MOTT infections requiring surgery,
resectional procedures are again being needed in the treatment of mycobacterial
disease.
PMID- 10689532
TI - History of esophageal surgery for benign disease.
AB - The article examines the history of esophageal surgery for benign disease,
looking at such surgeries as the first esophagotomy for a foreign body performed
in 1738 and the first esophageal replacement of the esophagus in 1894. Various
diseases are discussed, including stricture of the esophagus, hiatal hernia and
gastroesophageal reflux, diverticula of the esophagus, and motility disorders
such as achalasia.
PMID- 10689533
TI - The history of surgery for carcinoma of the esophagus.
AB - Carcinoma of the esophagus is a highly lethal disease in which surgical resection
is part of every treatment regimen carried out with curative intent. The
development of surgical resection of the esophagus for carcinoma has been a long
and tortuous one. Its evolution depended not only on a thorough knowledge of
surgical anatomy and technique, but also on important developments in endoscopy,
radiology, anesthesia, nutrition, pulmonary physiology, and intensive care.
PMID- 10689534
TI - The history of surgery of the thymus gland.
AB - The history of surgery of the thymus gland is presented through highlights and
landmark publications ranging from prehistoric times to the present day. The
evolution of surgical techniques includes transcervical and transthoracic
thymectomy along with other techniques such as current thoracoscopic VATS
procedures. The significance of myasthenia gravis, autoimmunity, thymic oncology,
adjuvant developments, and speculation on the future is discussed.
PMID- 10689535
TI - Historical review of blunt injury to the thoracic aorta.
AB - This article addresses the history of blunt injury to the aorta by reviewing the
epidemiology, military accounts, ancient history, and recent history during the
last five decades of the twentieth century. Although they are a bit arbitrary and
overlap somewhat, significant groupings regarding blunt injury to the thoracic
aorta have occurred in ten-year blocks. It is important that any surgeon not be
locked into a previous time period but be continually knowledgeable of ever
changing approaches. These approaches should always be based on the best evidence
based information available.
PMID- 10689536
TI - The history of surgery for thoracic outlet syndrome.
AB - The history of surgery for thoracic outlet syndrome (TOS) is examined, ranging
from the earliest recorded reference of TOS in the anatomic recognition of
cervical ribs by Galen and Vesalius, to the current research on the diagnosis and
treatment of TOS. The author discusses various cases that helped advance the use
of surgery in treating TOS, tracing the years of progress that led to the present
day understanding of the disease.
PMID- 10689537
TI - The history of lung transplantation.
AB - Experimental lung transplantation began in the former Soviet Union in 1946.
Experiments in the 1950s sought to understand the physiology and to master the
technique of reimplantation. Study of the immunology of allografting in the 1960s
lead to the first lung transplantation in a human in 1963 in the United States.
Palliative lung transplantation was first reported from Canada in 1986 after the
advent of effective and tolerable immunosuppressive regimens. Lung
transplantation in centers of excellence is now an effective palliative method
for more than 80% of carefully selected recipients. Widespread transplantation to
treat end stage pulmonary dysfunction is impossible because of too few organ
donors and imperfect management of rejection and infection.
PMID- 10689538
TI - Thoracic surgery training at the University of Michigan.
AB - The process of thoracic surgery resident education is and always has been taken
very seriously at the University of Michigan, where it is regarded as a key
mission of the faculty. More attention is paid to the details of providing a
supportive educational environment using established principles of education,
curriculum planning, evaluation, and feedback. Resident education is the order of
business today and, although challenged by the demands of managed care and cost
containment, it remains among the most important priorities at the University of
Michigan.
PMID- 10689539
TI - The history of mediastinal teratoma.
AB - The first discovery in 1823 of what has become known as mediastinal teratoma is
discussed. The uniqueness of this tumor with its various spontaneous
complications is described along with its early and often inept surgical
therapies. This article highlights the development of the surgical treatment of
mediastinal teratoma that has matured synchronously with the understanding of the
physiology of the chest and the evolution of modern surgery.
PMID- 10689540
TI - A diagnostic approach to musculoskeletal pain.
AB - Musculoskeletal pain or inflammation is one of the most common causes of primary
care office visits. Musculoskeletal disorders exact a high toll in distress,
disability, and direct health care costs. Given the wide range of disorders that
may cause or contribute to musculoskeletal symptoms, differential diagnosis is
challenging and a systematic approach is necessary. Patient history is the single
most valuable source of diagnostic information, followed by a careful physical
examination. The history also suggests which laboratory tests and imaging
studies, if any, are indicated. The chronology, duration, and pattern of pain
distribution offer clues to establishing an accurate diagnosis, along with
evidence of other organ system involvement or underlying disease. Helpful
distinctions are those between articular and nonarticular pain, between
monarthritis and multiple joint involvement, and between inflammatory and
noninflammatory conditions.
PMID- 10689541
TI - The role of the laboratory in the evaluation of rheumatic diseases.
AB - This article presents information on the role of immunologic laboratory tests in
evaluating patients with rheumatic disease. The focus is on 3 commonly used
tests: antinuclear antibodies, rheumatoid factor, and the erythrocyte
sedimentation rate. Background data on various statistical principles that are
key to interpretation of these tests are also discussed. The goal is to emphasize
that improper use and interpretation of such test results can lead to incorrect
diagnosis and unnecessary therapy, potentially putting the patient at risk. Thus,
these tests should be ordered in the context of other clinical information that
provides the practitioner with an accurate estimate of disease probability.
PMID- 10689542
TI - Osteoarthritis: a review.
AB - In 1994, the Centers for Disease Control and Prevention reported that by the year
2020, arthritis will have the largest increase in numbers of new patients of any
disease in the United States. The term arthritis refers to many diseases, the
most common of which is osteoarthritis (OA). OA affects at least 16 million
Americans, most of whom are older than 60 years. The disease is usually defined
using radiologic criteria. More than 80% of people older than 75 years are
symptomatic of OA. Considering cost of diagnosis, therapy (nonpharmacologic,
pharmacologic, and surgical), side effects of therapy, and lost productivity, it
is one of the more expensive and debilitating diseases in the United States.
Given the large numbers of patients and the expense of the disease, it is not
surprising that the diagnosis and care of patients with OA have come under
scrutiny. The following article will provide some background on the disease and
discuss management approaches that view the patient as a whole.
PMID- 10689543
TI - Recent advances in the treatment of rheumatoid arthritis.
AB - Rheumatoid arthritis (RA) affects about 0.5% to 1% of the population worldwide.
Because there is no cure for this disease, the goal of therapy is to control the
underlying inflammatory process and maintain or improve function. This article
reviews 4 new treatments for patients with RA: leflunomide, etanercept,
infliximab, and the protein A immunoadsorption column with plasmapheresis
therapy.
PMID- 10689544
TI - Early detection research network in the US.
PMID- 10689545
TI - Lack of association between body weight, bone mineral density and vitamin D
receptor gene polymorphism in normal and osteoporotic women.
AB - In an ethnically homogeneous population of women living in Tuscany, Italy, the
relationships between age, body weight, bone mineral density and the vitamin D
receptor (VDR) gene polymorphism were studied, with the objective of recognizing
patients at risk for osteoporosis. In 275 women bone mineral density was measured
by Dual Energy X-rays Absorptiometry (DEXA). In 50 of them the individual genetic
pattern for VDR was evaluated by DNA extraction followed by PCR amplification of
the VDR gene, and digestion with the restriction enzyme BsmI. Age and bone
mineral density were inversely related (R2 = 0.298). Body weight was associated
with bone mineral density (R2 = 0.059), but not with age. In osteoporotic women,
mean (+/- SD) body weight was 59.9 +/- 6.5 Kg, lower than that recorded in non
osteoporotic women (64.2 +/- 9.4 Kg), even though not significantly different (p
= 0.18). No association was found between VDR gene polymorphism, bone density or
body weight. The performance of anthropometric and genetic components appear to
be poor, and, at least for the time being, bone mineral density measurement by
means of MOC-DEXA represents the optimal method to detect women at risk for
postmenopausal osteoporosis.
PMID- 10689546
TI - Assessment of erythropoietin levels and some iron indices in chronic renal
failure and liver cirrhosis patients.
AB - This study was constructed to investigate the relationship between renal anaemia
and erythropoietin (EPO) concentrations in chronic renal failure (CRF) patients
and to evaluate the possible role of the liver. Serum EPO levels were measured in
blood samples from 20 CRF patients on hemodialysis (HD), 20 liver cirrhosis (LC)
patients, 20 patients having both CRF and LC and undergoing HD, and 20 normal
control subjects. Blood cell counts, iron indices (iron, total iron-binding
capacity (TIBC) and ferritin), renal function (blood urea nitrogen (BUN) and
creatinine), hepatic function (ALT, AST, ALP and bilirubin) investigations were
carried out for all the subjects enrolled in this study. CRF patients without LC
had serum EPO concentration of 6.21 +/- 0.53 mU/ml (mean +/- SE), which was
significantly higher than that in patients having both CRF and LC (4.32 +/- 0.52)
(p < 0.01). Both groups showed significantly lower values than the controls
(12.75 +/- 0.70) (p < 0.001). LC patients with intact kidneys had significantly
higher EPO level (22.70 +/- 1.70) (p < 0.001). No correlation was found between
EPO level and any of the hematologic or iron indices.
PMID- 10689547
TI - Serum lipoprotein (a) levels in chronic renal failure and liver cirrhosis
patients. Relationship with atherosclerosis.
AB - This study was carried out to investigate the relationship between lipoprotein
(a) levels and the development of atherosclerosis in chronic renal failure (CRF)
patients with the possible role of the liver. Serum Lp (a) levels were measured
in samples from 20 CRF patients on hemodialysis (HD), 20 liver cirrhosis (LC)
patients, 20 patients having both CRF and LC and undergoing HD, and 20 normal
control subjects. Renal function (blood urea nitrogen (BUN) and creatinine),
hepatic function (transaminases (ALT and AST), alkaline phosphatase (ALP) and
total bilirubin) investigations and serum cholesterol were carried out for all
the subjects enrolled in this study. Serum Lp (a) concentration in CRF patients
without LC was 87.25 +/- 6.17 mg/dl, which was significantly higher than all the
investigated groups (P < 0.001). Lp (a) concentration in patients with both CRF
and LC was 24.65 +/- 1.98 mg/dl, which was not significantly different from the
controls, but was significantly higher than that in the subjects with LC only (P
< 0.001) where the latter group had significantly low Lp (a) values (11.1 +/-
0.99) relative to all the other groups (P < 0.001). Lp (a) correlated positively
with cholesterol in all groups except the LC subjects, but did not correlate with
age, or renal function in both CRF groups.
PMID- 10689548
TI - Transforming growth factor-beta and nitrates in epithelial ovarian cancer.
AB - The role of transforming growth factor-beta (TGF-beta) and nitric oxide (NO) in
ovarian neoplasia is still not clear. We studied the expression of TGF-beta by
enzyme immunoassay, and nitrates (as a stable end product of NO) in 127 ovarian
tissues (36 normal, 37 benign, and 54 malignant). Ploidy status and synthetic
phase fraction (SPF) were also assessed by flow cytometry. Mean ranks of TGF
beta, nitrate, and SPF were significant among different groups (X2 = 12.01, P =
0.0025, X2 = 67.42, P = 0.000, X2 = 9.06, P = 0.011 respectively). Nitrate mean
ranks were significant among different FIGO stages of the disease (X2 = 17.6, P =
0.000). A significant correlation was shown between TGF-beta, and nitrate levels
in all tissues (r = 0.24, P = 0.01), as well as in malignant tissues (r = 0.3, P
= 0.026). Cutoff values were determined for both TGF-beta (290 pg/mg protein),
and nitrates (310 nmole/mg non protein nitrogenous substances). At these cut
offs, nitrates showed a sensitivity of 93% and 84% specificity for malignant
versus normal cases, while TGF-beta had 76% sensitivity, and 82.4% specificity
for poor versus good outcome. Patients with epithelial ovarian cancer were
followed up for a total of 40 months. Survival analysis showed that patients with
TGF-beta above the cut-off had worse prognosis (X2 = 12.69, P = 0.004). The
present results suggest that malignant transformation of ovarian tissues is
associated with increased TGF-beta and NO production. NO level is related to the
development and progression of epithelial ovarian cancer, while high levels of
TGF-beta could be of prognostic significance.
PMID- 10689549
TI - Menstrual cycle dependent variability for serum tumor markers CEA, AFP, CA 19-9,
CA 125 and CA 15-3 in healthy women.
AB - Information on menstrual cycle dependent variation of tumor markers in healthy
women is a subject of diagnostic efficiency and has an impact in elucidating the
normal function of these markers. In this study midfollicular and midluteal
concentrations of serum CEA, AFP, CA 19-9, CA 125, CA 15-3 and their relations
with LH, FSH, prolactin, estradiol and progesterone were evaluated during
ovulatory cycles in a group of 23 healthy female individuals. Samples were
collected on the 7th and 21st day of the same menstrual cycle. Tumor marker and
hormone concentrations were determined with chemiluminescence or
electrochemiluminescence EIA methods. A significant phase-dependent difference
was observed for CA 15-3, midluteal concentrations (mean +/- SEM; 26.33 +/- 1.56
U/ml) higher than the midfollicular (mean +/- SEM; 19.27 +/- 1.49 U/ml)
concentrations (p < 0.001). But an obvious difference for other tumor markers
investigated did not exist. Significant correlations of follicular and luteal CA
125 levels with body mass index of the subjects were observed (r:0.52, p < 0.05
and r:0.57, p < 0.005, respectively). CA 15-3 antigen is a product of the MUC-1
gene which is expressed in abundance by endometrial epithelial cells in the
secretory phase of the menstrual cycle which may be the potential source of
variability. The association of CA 125 levels with obesity suggests a possible
role of adipose tissue in CA 125 metabolism. In conclusion our data suggest that
in healthy women serum CA 15-3 levels are significantly elevated in the midluteal
phase of the menstrual cycle compared to midfollicular phase. Therefore,
consideration of menstrual cycle dependent variability for CA 15-3 appears
indicated in interpretation of individual results.
PMID- 10689550
TI - Novel, non-radioactive, simple and multiplex PCR-cRFLP methods for genotyping
human SP-A and SP-D marker alleles.
AB - We have previously identified an allele of the human SP-A2 gene that occurs with
greater frequency in an RDS population [12]. Because of the importance of SP-A in
normal lung function and its newly emerging role in innate host defense and
regulation of inflammatory processes, we wish to better characterize genotypes of
both SP-A1 and SP-A2 genes. It has been determined that SP-D shares similar roles
in immune response. Therefore, in this report we 1) describe a novel, non
radioactive PCR based-cRFLP method for genotyping both SP-A and SP-D; 2) describe
two previously unpublished biallelic polymorphisms within the SP-D gene; 3)
present the partial sequence of one new SP-A1 allele (6A14) and describe other
new SP-A1 and SP-A2 alleles; and 4) describe additional methodologies for SP-A
genotype assessment. The ability to more accurately and efficiently genotype
samples from individuals with various pulmonary diseases will facilitate
population and family based association studies. Genetic polymorphisms may be
identified that partially explain individual disease susceptibility and/or
treatment effectiveness.
PMID- 10689552
TI - Placental growth, fetal growth and maternal RhE genotype.
PMID- 10689551
TI - Lipid peroxidation and antioxidant status in human cervical carcinoma.
AB - Reactive oxygen species (ROS), represented by superoxide, hydrogen peroxide and
hydroxyl radicals, have been implicated in many diseases including cancer. ROS
have been known to play an important role in the initiation and promotion of
multistep carcinogenesis. The cellular antioxidants play a crucial role in
protection against neoplastic disease. However, very little is known about the
antioxidant defense in cervical carcinoma. This is addressed in the present
study. Lipid peroxides, glutathione content and the activities of antioxidant
enzymes, together with vitamin C and E content, were estimated in patients who
had carcinoma of the cervix, and the values were compared with those of normal
women. The results showed a remarkable reduction in the content of glutathione,
vitamin E and C. Activities of glutathione peroxidase and superoxide dismutase
were also reduced in cervical cancer compared to normal controls (P < 0.001).
This reduction was more marked in late stages (III, IV) than in early stages (I,
II) (P < 0.001). Glutathione was reduced more in poorly differentiated tumors
(grade III) than in well and moderately differentiated ones (grade I, II) (P <
0.05). Levels of lipid peroxides were found to be significantly higher in
malignant than in normal tissue samples and their levels were correlated with
advanced clinical stage (P < 0.001). Our results suggest impaired antioxidant
status in carcinoma of the cervix. This impairment is related to tumor
progression.
PMID- 10689553
TI - Ultrastructural changes in microvessel with age in the hippocampus of senescence
accelerated mouse (SAM)-P/10.
AB - Microvessels in the hippocampus of aged SAM-P/10 (14 months old) showed the
following ultrastructural changes compared with those of young-mature controls (3
months old): (1) the majority of capillaries had lost the smooth contours typical
of young cases; (2) the luminal surface of capillaries showed irregularity; (3)
the endothelial cytoplasm was thicker; (4) vesicles appeared more frequently in
the endothelium; (5) interendothelial tight junctions and basement membranes,
however, seemed to show no significant abnormalities; (6) pericytes, especially
those of arterioles and venules, contained many enlarged cytoplasmic inclusions
with honeycomb-like vacuoles; (7) the area of glial perivascular end feet was
greater. These morphological findings raise the possibility of impaired blood
brain barrier function and microhemodynamic disturbances in aged SAM-P/10
hippocampus.
PMID- 10689554
TI - Learning and self-regulation of slow cortical potentials in older adults.
AB - Two groups of subjects, aged 20-28 and 50-64, respectively, matched for health
status and verbal abilities, learned to control their slow cortical potentials
(SCP) in a feedback paradigm by producing, on command, SCP shifts in either
positive or negative direction. Both groups were able to differentiate
significantly between the positivity task and the negativity task, with the
differentiation score being only slightly (and not significantly) lower in older
than in younger subjects. In all conditions, however, significantly more negative
brain responses were obtained in older than in younger subjects. This effect was
larger in the positivity task versus negativity task, and larger in trials
without continuous SCP feedback versus trials with feedback. Additionally four
learning tasks were carried out with all subjects. The older group demonstrated
substantial performance deficits in two tasks with explicit learning (verbal and
visual). In contrast, implicit learning (perceptual learning and skill
acquisition) was not impaired with age. The results are at odds with the idea of
general age-related learning deficit and concur with the hypothesis that only
explicit, but not implicit, learning processes are compromised in older subjects.
The pattern of consistently more negative SCP shifts produced by elderly subjects
may indicate their impaired cortical inhibition. Another interpretation, which
does not exclude the inhibitory deficit hypothesis but seems to better agree with
other psychophysiological data, may be that older subjects have disturbance in
the system controlling arousal and effort.
PMID- 10689555
TI - Aging and negative priming: is ignored information inhibited or remembered?
AB - We had younger and older adults complete two tasks that tested the attentional-
and memory-based inhibition models of negative priming. One task violated May,
Kane, & Hasher (1995, Psychological Bulletin, 118, 35-54) criteria for measuring
just attentional inhibition, by including a repeated-target condition. The other
task complied with these criteria and included a depth of processing
manipulation, where participants selected prime targets based either on their
letter-length (nonsemantic processing) or weight (semantic processing). On
balance, results supported the memory model, because depth of processing clearly
moderated younger adult negative priming, and older adults displayed negative
priming only in the task satisfying the attentional-inhibition criteria (i.e.,
the depth of processing task). We conclude that memory factors moderate negative
priming, and that May et al.'s criteria fail to predict when older adults will
show the effect.
PMID- 10689556
TI - Age effect in recall performance according to the levels of processing,
elaboration, and retrieval cues.
AB - The present study was conducted to investigate the incidence of several factors
contributing to age-related memory decrement. Variables manipulated include
quality (level of processing encoding conditions), the degree of effort and
encoding quantitative elaboration (active/passive encoding conditions), and the
influence of retrieval support (free-/cued recall conditions). In support of the
environmental support hypothesis, middle-old and old subjects benefited more than
young ones from cued recall in all the memory tests. Moreover, the results showed
a differential (qualitative vs. quantitative) impairment of conceptual processing
between the middle-old and the old-age groups. In the middle-olds, age
differences were abolished by deep processing in old adults, age differences were
attentuated only with deep and active processing associated with retrieval
support. These gradual memory impairments are evaluated according to Mandler's
model of memory (1979, In L. G. Nilsson [Ed.], Perspective in memory research.
Hillsdale: Lawrence-Erlbaum), and the environmental support hypothesis is
discussed in terms of the involvement of encoding and retrieval operations
required by the memory task.
PMID- 10689557
TI - Source monitoring and false recollection: a life span developmental perspective.
AB - In a variation of Deese's (1959, Journal of Experimental Psychology, 58, 17-22)
list-learning paradigm, 32 first-graders, 32 younger adults, and 24 older adults
self-generated words that were semantically related to study items prior to
recall. This manipulation increased false recollection for children and older
adults, but not for younger adults. These data suggest that source-monitoring
deficits underlie children's and older adults' illusory memories within the list
learning format. The differential roles played by source monitoring versus
declarative memory in the production of false memories are discussed from a life
span developmental perspective.
PMID- 10689558
TI - Perceived ability and level of education as predictors of traditional and
practical adult problem solving.
AB - Sixty adults (ages 19 to 80) were divided into three age groups. Each individual
completed the Problem Solving Inventory (PSI), which assesses an individual's
self-perception of problem-solving ability, prior to completing two types of
problems, including concept-identification tasks and six everyday, practical
problems. When the level of education across the younger, middle-aged, and older
adults was controlled, older individuals perceived themselves as better problem
solvers, and they were more confident in their problem-solving abilities than the
other age groups. Additionally, these older adults with relatively high levels of
education took more time to complete the concept-identification tasks but did not
make more errors or need more choices to solve these tasks. Similarly, the older
participants performed as well as either of the other age groups on the everyday,
practical problems.
PMID- 10689559
TI - Potential problems with the interpretation of hair analysis results.
AB - Due to differences in hair growth rate depending on anatomical region, age,
gender, ethnicity and interindividual variability, interpretation of parent drug
or/and metabolite concentrations in hair is not easy. Furthermore, as drug
incorporation mechanisms into hair matrix is not yet fully understood, it is
rather difficult to extrapolate details on time and dose from hair segment
analysis. If incorporation sources other than from bloodstream (skin secretions
and/or external/environmental contamination) are considered, interpretation
becomes even more complicated. For evaluating possible passive contamination, it
is essential to consider specific identification of metabolites, use of
metabolite-to-parent drug ratios, assays of decontamination washes and analysis
of specimens collected from other body parts. Cosmetic hair treatment, natural
and artificial hair colour, differences in hair structure and specificity of
analytical methodology may represent other bias sources affecting concentrations
of drugs in hair. A suitable cut-off level related to the LOD will allow correct
identification of drugs or metabolites in hair. Regarding the performance of
different hair testing laboratories, little information is available at this time
to what extent test results are comparable and their interpretation is
consistent. Frequency of drug consumption and time intervals between multiple
consumption or lag time between consumption and appearance in the hair has not
been fully investigated and needs further research.
PMID- 10689560
TI - Statistical examination of hair color as a potential biasing factor in hair
analysis.
AB - We review eight different data sets in this paper for the purposes of assessing
the possibility that reported color of hair can produce a systematic bias in the
interpretation of hair assays. We review studies or data sets that include heroin
and its metabolites, cocaine and its metabolites, MDMA and its analogs, and
amphetamine and methamphetamine. The studies have utilized a variety of different
degrees of color categorization, ranging from the simple dichotomy of brown and
black, to a high of 12 categories. The mean number of categories reported
approaches 6 (mean = 5.875). There are a total of 2791 data points in this
analysis. We utilize two major statistical techniques for assessing significance;
one-way analysis of variance, and Tukey's Honestly Significant Difference
procedure. In circumstances were only dichotomous contrasts are possible, one-way
analysis of variance is used. In contrasts involving three or more categorical
groups, Tukey's procedure is used. In circumstances where the homogeneity of
group variances is not sustained by the Levene statistic, we use the Tamahane
procedure, allowing an assessment that assumes unequal variances. The analysis of
this data fails to discern a significant color effect. We speculate that it may
be that variance is large in many domains affecting analyte recovery from hair.
In large groups these variations tend to regress towards a typical or mean value.
Thus the data here show that while there are group or aggregate differences in
these 'typical' values, they are not great when considered in relation to the
within-group variations which exist for those values. It is our view that color
may play a role in the accumulation of drugs in hair, however it is likely to
account for only a very small part of the complex process of drug accumulation.
PMID- 10689561
TI - Evidence for bias in hair testing and procedures to correct bias.
AB - A number of in vitro experiments show that different hair samples incorporate
differing amounts of drugs under identical conditions. Incorporation of cocaine
and morphine tends to be correlated with race, in that the hair of African
American females incorporates higher concentrations of cocaine than does the hair
of Caucasian males or females. Extrapolation of these data into populations has
been fraught with difficulties because the dosages of drugs and their use
patterns are unknown. Cosmetic treatments and hygiene alter drug binding, which
must be considered in comparing populations because cosmetic treatments are often
group dependent. Four reasons are proposed that account for the uptake and
retention of drugs by hair and that may differ among groups: (1) permeability and
other characteristics of the hair due to genetic influences, (2) cosmetic hair
treatments and hair care habits (which may be culturally influenced), (3) drug
removal during personal hygiene, and (4) manner and route of drug administration
which can affect passive exposure to residual drugs in the environment. The data
supporting bias in hair testing are reviewed and methods are proposed that use
either the uptake of dyes or the incorporation of drug homologs to reduce bias.
PMID- 10689562
TI - Hair analysis for drugs of abuse. Hair color and race differentials or systematic
differences in drug preferences?
AB - There is currently a debate in the literature on chemical drug analysis
concerning the contribution of biophysical attributes associated with specimens
and specimen donors to assay outcome. In recent years this debate has focused on
hair analysis, but has in the past also been raised in urinalysis interpretation.
In this article we examine several aspects of that controversy. First, we present
data regarding the effects of hair color on the distribution of positive hair
testing results for three drug classes. We compare these results to negative hair
samples from comparable donors. This data is derived from head hair from
preemployment donors that was classified according to seven visual color
categories. We determined the distribution of colors for hair samples devoid of
any of three assayed drugs (amphetamines, cocaine, and cannabinoids).
Subsequently, this distribution was compared with the distributions for hairs
that had tested positive for amphetamines, cocaine or cannabinoids. We examined a
total of 2000 randomly selected samples; 500 negative hair samples and 500
positive samples for each of three drugs: cannabinoids, cocaine, and amphetamine.
We also evaluated ethnic/racial factors in relation to positive urinalyses for
various ethnic/racial groups. We examined approximately 4000 urine specimens from
two different groups, each constituting around 2000 specimens. In addition to
ethnicity/race and urinalysis outcome, we also examined the relationship between
the hair color distributions of urine donors and the corresponding urinalysis
results for the three drug classes. We also compared them to drug-negative
samples. Our summary impression is that the observed outcome patterns were
largely consistent with differences in drug preferences among the various
societal groups. There was little evidence of a pattern attributable to hair
color bias alone or selective binding of drugs to hair of a particular color.
Likewise, there was no discernible pattern associated with race or ethnicity that
would lend support to a "race effect" in drug analysis.
PMID- 10689563
TI - Influence of bleaching on stability of benzodiazepines in hair.
AB - In order to study the influence of hair bleaching on benzodiazepines
concentrations, hair was treated with a bleaching product (Poly Blonde,
Schwarzkopf & Henkel) for 20 min. The treated hair specimen was obtained from a
person who died after an overdose of several illicit drugs associated with
benzodiazepines. Bleached and non bleached hair were washed (acetone and water),
pulverised and then incubated for 2 h in a thioglycolic solution. In the extracts
obtained by solid-phase extraction on C18 columns, the different drugs with the
corresponding deuterated standards were derivatized and determined by GC-MS in a
SIM mode. These results show that the concentrations of all the drug detected
decreased in bleached hair in comparison with non treated hair. Whereas the
diminution was less important for cocaine and benzoylecgonine (decrease of 24.6
and 36.4%, respectively), concentrations for codeine, 6-monoacetylmorphine and
morphine decreased more significantly (decrease of 57.5, 88.6 and 67.4%,
respectively) as well as those of diazepam, nordazepam and 7-aminoflunitrazepam
(decrease of 39.7, 67.7 and 61.8%, respectively). The results in this study agree
with those of other authors that bleaching affects the stability of cocaine and
opiates incorporated in hair. These findings also point out that bleaching
influences the stability of entrapped benzodiazepines in hair. Finally, these
results reconfirm that it is very important to consider the cosmetic history of a
hair sample in the interpretation of hair analysis results.
PMID- 10689564
TI - The incorporation of dyes into hair as a model for drug binding.
AB - The binding of charged substances from external aqueous media to hair has been
investigated through the use of fluorescence microscopy. Eleven hair samples,
reflecting various ethnic groups and cosmetic treatments, were tested. Rhodamine
6G, a cationic dye representative of drugs such as cocaine and opiates, showed
incorporation throughout the hair of all samples except one. In contrast,
fluorescein, an anionic dye representative of drugs such as THC carboxylic acid,
was not readily incorporated. The incorporation of rhodamine 6G was faster for
chemically 'straightened' and bleached African-American female hair than for
untreated hair. Incorporation of rhodamine 6G followed a pH dependence, but an
ionic strength dependence could not be established. These studies support three
postulates: (1) electrostatic interactions explain the preferential binding of
cationic drugs of abuse to hair; (2) the hair matrix, or the non-helical portion
of hair, is accessible to external solutions and thus subject to contamination;
and (3) cosmetic treatments may alter the helical portion of hair thereby
increasing its accessibility to external contamination.
PMID- 10689565
TI - Experimental designs in the optimisation of ultrasonic bath-acid-leaching
procedures for the determination of trace elements in human hair samples by
atomic absorption spectrometry.
AB - Experimental designs were used for the optimisation of acid-leaching procedures
assisted by ultrasonic energy for the extraction of Ca, Cu, Fe, Mg, Mn and Zn
from human hair samples. A Plackett-Burman 2(7) x 3/32 design for seven factors
([HNO3], [HCl], [H2O2], acid/oxidant solution volume, exposure time to
ultrasounds, temperature of the ultrasonic bath and hair particle size) was used
in order to choose the variables affecting the acid-leaching process. The
variables [HNO3], [HCl] and temperature of the ultrasonic bath were found to be
the most important parameters for the acid-leaching procedure, and these
variables were optimised by a response surface design (central composite design
2(3) + star) which involved 16 experiments. Optimum values in the 3.7-4.2 M range
were found for [HNO3], while optimum values between 3.0 and 3.5 M were found for
[HCl]. The optimum temperature of the ultrasonic bath was between 80 and 90
degrees C. An acid digestion induced by microwave energy (details given) was used
to obtain the total metal concentration and also for comparative purposes. Ca,
Cu, Fe, Mg and Zn were measured by flame atomic absorption spectrometry (FAAS)
using a conventional air/acetylene flame, while Mn was determined by
electrothermal atomic absorption spectrometry (ETAAS) under optimised conditions.
Two different reference materials, IAEA-085 International Atomic Energy Agency,
Monaco) and NIES No. 13 (National Institute for Environmental Studies, Japan),
with certified metal contents for some of the elements investigated, were used in
order to verify the accuracy of the methods.
PMID- 10689566
TI - Hair analysis by using radioimmunoassay, high-performance liquid chromatography
and capillary electrophoresis to investigate chronic exposure to heroin, cocaine
and/or ecstasy in applicants for driving licences.
AB - The present paper describes an integrated diagnostic strategy to check the
physical fitness of subjects, formerly users of illicit drugs, to obtain a
driving license, after having quit their addiction. According to the Italian law,
applicants for a driving license with a history of drug abuse must give evidence
to have quit this behaviour and to show no risk of relapse in the future. To
prove this, at our institute, they undergo medical examination, hair analysis and
a urinalysis program on eight seriate samples, collected over about 40 days.
About 700 subjects per year are investigated with this strategy. The hair samples
are screened for opiates (morphine), cocaine and ecstasy, the most abused illicit
substances in our region, by using commercial radioimmunoassays adopting cut-off
levels of 0.1 ng/mg. All positive samples and about 10% of negatives are
confirmed by high-performance liquid chromatography. Further confirmation of
results can be carried out by capillary electrophoresis (and/or GC/MS or MS/MS).
In 1998, the prevalence of positives for morphine, cocaine and ecstasy was 4.8,
11.3 and 2.6%, respectively. In this year, for the first time, the percentage of
hair samples positive for cocaine was greater than that for opiates. The results
of this integrated diagnostic strategy are presented and discussed, with
particular emphasis on the comparison between hair analysis on a single sample
and seriate urinalyses (on eight samples).
PMID- 10689567
TI - Use of headspace solid-phase microextraction (HS-SPME) in hair analysis for
organic compounds.
AB - Headspace solid phase microextraction (HS-SPME) has advantages of high purity of
the extract, avoidance of organic solvents and simple technical manipulation and
can be used in combination with gas chromatography-mass spectrometry (GC-MS) in
the hair analysis of a number of drugs. HS-SPME coupled with the hydrolysis of
the hair matrix by 4% sodium hydroxide in the presence of excess sodium sulphate
and of a suitable internal standard proved to be a convenient one-step method for
the measurement of many lipophilic basic drugs such as nicotine, amphetamine
derivatives, local anaesthetics, phencyclidine, ketamine, methadone,
diphenhydramine, tramadol, tricyclic antidepressants and phenothiazines.
Detection limits were between 0.05 and 1.0 ng/mg. From spiked 10-mg hair samples
absolute recoveries between 0.04 and 5.7% were found. These recoveries decreased
considerably if larger sample amounts were used, perhaps due to increased drug
solubility in the aqueous phase or to elevated viscosity in the presence of
dissolved hair proteins. Because of the phenolic hydroxyl group a change of pH
after alkaline hair digestion (by adding excess orthophosphoric acid) was
necessary for the detection of delta 9-tetrahydrocannabinol (delta 9-THC),
cannabinol (CBN) and cannabidiol (CBD) by HS-SPME. Nevertheless, the detection
limits were such that only CBN could be detected in hair of a consumer.
Clomethiazole, a compound hydrolysed in alkali, was measured by HS-SPME after
extraction with aqueous buffer. The detection limit was 0.5 ng/mg. Cocaine could
not be detected by HS-SPME. The application of HS-SPME to hair samples from
several forensic and clinical cases is described.
PMID- 10689568
TI - Selenium determination in mother and child's hair by electrothermal atomic
absorption spectrometry.
AB - A method for the selenium determination in a mother and her child's hair using
palladium as a chemical modifier was optimized. The sample was digested with
nitric acid and hydrogen peroxide and diluted to 5 ml. To achieve complete
mineralization the samples were ashed at 1200 degrees C in the presence of
palladium as a chemical modifier. The optimum atomization temperature was 1900
degrees C. The precision and accuracy of the method were studied using the
reference material CRM 397. Results of calibration using aqueous standards and
the standard addition method were compared. The method was applied to the
selenium determination in 30 samples of the mother's and child's hair. The levels
found were 0.54 +/- 0.34 microgram/g for mother's hair and 0.77 +/- 0.25
microgram/g for child's hair.
PMID- 10689569
TI - Simultaneous hair testing for opiates, cocaine, and metabolites by GC-MS: a
survey of applicants for driving licenses with a history of drug use.
AB - A sensitive GC-MS method for the simultaneous determination of opiates, cocaine,
and metabolites in hair at a cut-off level of 0.1 ng/mg was adopted to assess
past exposure to these drugs in applicants for driving licenses with a history of
drug use. The sampling protocol consisted of collection of one hair (sample A, 5
cm length) and one urine sample. When hair and urine (EMIT Syva, cut-off levels:
0.3 mg/l for opiates, 0.15 mg/l for cocaine, GC-MS confirmation of positives)
were both positive or negative the protocol was concluded. In the other cases,
the assessment of 'current exposure' to drugs was carried out, in order to avoid
seriated random urinalysis, by collecting a second hair sample (sample B) 6 weeks
later and analysing the proximal 1-cm segment. Out of the 214 'A' hair samples
analyzed, 14 (6.5%) tested positive for morphine and/or 6-acetylmorphine (6AM),
and 26 (12%) for cocaine and/or benzoylecgonine (BE), whereas none of the samples
tested positive for both drugs. Levels between 0.1 and 1 ng/mg of the single
analytes were found in eight out of the 14 morphine-6AM positives (57%) and in 18
out of the 26 cocaine-BE positives (69%). The time course of positive cases
showed a progressive decrease of morphine-6AM positives and a corresponding
increase of cocaine-BE positives within the study period September 1995-February
1999. No cases with positive urine and negative hair were observed. Among the 40
positive cases, seven (four and three for opiates and cocaine, respectively) were
found to be 'currently exposed to drug', four by urinalysis (three and one) and
three by analysis of the hair sample B (1 and 2).
PMID- 10689570
TI - Tandem mass spectrometry: a helpful tool in hair analysis for the forensic
expert.
AB - The Bavarian State Bureau of Investigation in Munich has the exclusive
responsibility for investigation of criminal acts. One considerable expertise is
that of hair analysis. According to the legal system in Germany, there is a
special interest when some clients' hair tested positive for illicit drugs. An
accused with a lot of drugs in his hair will be treated as a supposed addict and
will be guaranteed extenuating circumstances. The instrumentation used for hair
analysis is a powerful analytical tool: a Varian 3400 gas chromatograph linked to
a Finnigan Tandem-MS (TSQ 700). The methanol extraction method is used for the
detection of illegal drugs and metabolites: amphetamine, methamphetamine, MDA,
MDMA (ecstasy), MDE, MBDB, methadone, THC, EDDP (metabolite of methadone),
cocaine, benzoylecgonine, cocaethylene, opiates (dihydrocodeine, codeine, heroin,
6-monoacetylmorphine, morphine, acetylcodeine). For the detection of 9-carboxy
THC by negative chemical ionization the hair sample is hydrolyzed under alkaline
conditions. Solid-phase extraction is used for clean-up. The LOQ for the
determination of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic-acid is 0.16
pg/mg hair. An unsurpassed combination for rendering an expert opinion based on
hair analysis may be: a forensic expert using diligence and experience, coupled
with the performance of a sophisticated analytical instrument.
PMID- 10689571
TI - Analysis of LSD in human body fluids and hair samples applying ImmunElute
columns.
AB - Immunoaffinity extraction units (LSD ImmunElute) are commercially available for
the analysis of lysergic acid diethylamide (LSD) in urine. The ImmunElute resin
contains immobilized monoclonal antibodies to LSD. We applied the ImmunElute
procedure to serum and also to human hair samples. For hair analysis the samples
were first extracted with methanol under sonication. The extracts were then
purified using the ImmunElute resin. LSD analysis was carried out with HPLC and
fluorescence detection. The immunoaffinity extraction provides highly purified
extracts for chromatographic analysis. The limit of detection (signal-to-noise
ratio = 3) has been determined to be < 50 pg regardless of which sample material
was used. The procedure was applied to authentic hair samples from drug abusers
(n = 11). One of these samples tested positive with an amount of 110 pg LSD in
112 mg extracted hair corresponding to a concentration of 1 pg/mg.
PMID- 10689572
TI - The use of supercritical fluid extraction for the determination of amphetamines
in hair.
AB - A laboratory study interested in the analysis of human hair for drugs-of-abuse
was conducted to determine if drugs could be detected and quantified from hair.
Supercritical fluid extraction (SFE) techniques followed by GC-MS analysis were
applied to extract amphetamines from hair. The group of amphetamines included
methylenedioxyamphetamine (MDA), methylenedioxymetamphetamine (MDMA),
methylenedioxyethylamphetamine (MDEA) and internal standard mephentermine (MP).
To validate information on amphetamine use in hair, powdered hair samples free
from drugs were collected and soaked in a known amphetamine standard solution.
Authentic fortified case hair samples taken from known drug users known to have
consumed amphetamines were also analyzed for amphetamine. Results from this study
show that amphetamine use can be detected in spiked and authentic fortified human
hair using SFE techniques for qualitative and quantitative reproducible results.
PMID- 10689573
TI - Are there possibilities for the detection of chronically elevated alcohol
consumption by hair analysis? A report about the state of investigation.
AB - The analysis of suitable ethanol markers in hair would be an advantageous tool
for chronic alcohol abuse control because of the wide diagnostic window allowed
by this specimen and the possibility of segmental investigation. Between the
markers practically used or thoroughly investigated in blood or urine,
ethylglucuronide, fatty acid ethylesters, phosphatidylethanol, acetaldehyde
adducts to protein and 5-hydroxytryptophol can be regarded as possible candidates
also in hair, but preliminary data were found in the literature only for
ethylglucuronide and acetaldehyde modified proteins. By using headspace gas
chromatography and headspace solid phase microextraction in combination with gas
chromatography-mass spectrometry (SPME-GC/MS), in alkaline hydrolysates of hair
it was possible to determine between 17 and 135 ng/mg of ethanol beside acetone
and several other volatile compounds with slightly higher ethanol values for
alcoholics than for social drinkers and teetotalers. A part of this is ethanol
only absorbed in the hair matrix from the surrounding environment and
consequently is not applicable as a diagnostic criterion. By extraction with
aqueous buffer, methanol or a methanol/chloroform mixture and subsequent alkaline
hydrolysis it was found that another part is generated from ethylesters, which
are preferentially deposited in the lipid fraction of hair. In a specific search
for ethylesters of 17 carboxylic acids by GC/MS-SIM in most cases ethyl 4
hydroxybenzoate (0.1 to 5.9 ng/mg, a preservative in hair cosmetics) and in four
cases traces of indolylacetic acid ethylester were found. Furthermore, diethyl
phthalate (a softening agent, present also in many cosmetic products) was
identified in the hair of alcoholics as well as of children. As potential markers
of alcohol intake, ethyl palmitate, ethyl stearate and ethyl oleate were detected
in hair samples of alcoholics by headspace SPME-GC/MS of the chloroform/methanol
extracts.
PMID- 10689574
TI - Use of solid-phase microextraction (SPME) for the determination of methadone and
EDDP in human hair by GC-MS.
AB - Solid-phase microextraction (SPME) is a new extraction technique with many
advantages: small sample volume, simplicity, quickness and solvent-free. It is
mainly applied to environmental analysis, but is also useful for the extraction
of drugs from biological samples. In this paper the use of SPME is proposed for
the determination of methadone and its main metabolite EDDP in hair by GC-MS. The
hair samples were washed, cut into 1-mm segments, and incubated with Pronase E
for 12 h. A 100-micron polydimethylsiloxane (PDMS) film fibre was submerged for
30 min in a diluted solution of the hydrolysis liquid (1:4 with borax buffer)
containing methadone-d3 and EDDP-d3 as internal standards. Once the
microextraction was concluded the fibre was directly inserted into the CG
injection port. Linearity was found for methadone and EDDP in the range studied,
1.0-50 ng/mg hair, with correlation coefficients higher than 0.99. Interassay
relative standard deviation (R.S.D) was determined to be less than 13.30% for
methadone and less than 8.94% for EDDP, at 3.0 and 30.0 ng/mg. Analytical
recoveries were close to 100% for both compounds on spiked samples. The method
was applied to the analysis of real hair samples from eight patients of a
methadone maintenance programme. The concentration of methadone in hair ranged
from 2.45 to 78.10 ng/mg, and for EDDP from 0.98 to 7.76 ng/mg of hair.
PMID- 10689575
TI - Incorporation of propyphenazone in beard hair of a migraine patient.
AB - The incorporation of propyphenazone in beard hair after consumption of this
substance present in the analgesic Migraine-Kranit (Codali) was investigated.
Because of a migraine attack a volunteer took four tablets of Migraine-Kranit
(one tablet contains 150 mg propyphenazone) the first day and two tablets the
second day. Shaved beard hair was collected 48, 72, 96 and 120 h after the first
consumption of the analgesic drug. These hair specimens were washed (acetone and
water), pulverized and then incubated during 2 h in a thioglycolic solution.
After solid-phase extraction on C18 columns, propyphenazone was assayed in these
extracts by GC/MS operating in selected ion monitoring mode (m/z 230, 215).
Diazepam-d5 was used as an internal standard. In hair specimen 1 (48 h after
consumption) the highest concentration was found (170 pg/mg hair). In hair
specimen 2 (72 h) and 3 (96 h) the concentration were significantly lower (44 and
18 pg/mg, respectively). After 120 h no propyphenazone could be detected (limit
of detection: 5 pg/mg hair). These results show that propyphenazone was already
in beard hear 2 days after consumption, whereas no more presence could be shown
after 120 h. As the time period of 2 days is too short to allow entrapment into
the hair matrix from bloodstream and growing of hair out of the follicle, our
results suggest that incorporation of propyphenazone may be mainly due to
excretion in sweat and subsequent incorporation into the hair.
PMID- 10689576
TI - Detection of THCCOOH in hair by MSD-NCI after HPLC clean-up.
AB - Regular consumption of cannabis can easily be detected by examination of hair for
tetrahydrocannabinol, cannabinol, and cannabidiol. Although several studies have
demonstrated that after contamination with smoke or treatment with THC containing
shampoos THC is not detectable, or only in small traces, the detection of 11-nor
9-carboxy-delta 9-tetrahydrocannabinol (THCCOOH) should be offered to prove the
consumption and metabolisation of THC. Up to now this confirmation was only
available using tandem MS techniques combined with negative chemical ionisation.
A new method using a normal quadrupole GC/MS is described. The lack of expensive
instruments has to be paid for by a costly and time consuming extraction and
clean-up. After the sample has been digested by 2 M NaOH at 95 degrees C and the
neutralised liquid has been extracted with a mixture of n-hexane and ethyl
acetate the dried residue is reconstituted in acetonitrile-methanol-0.01 M
sulfuric acid (49:21:30, v/v/v) and the cannabinoids separated by HPLC. Each
fraction is collected over 1 min. Another extraction with n-hexane-ethyl acetate
is followed by evaporation, derivatisation, and GC/MS determination. The
calibration with THCCOOH spiked hair led to a LOD of 0.3 pg/mg and a LOQ of 1.1
pg/mg.
PMID- 10689577
TI - Hair analysis by immunological methods from the beginning to 2000.
AB - Immunoassays for hair testing must satisfy three requirements: (1) They must have
cross-reactivity with parent drug and lipophilic metabolites actually found in
hair (2) they must not experience interference from the dissolved hair matrix and
(3) they must be titered for cutoffs appropriate to the drug concentrations found
in hair. Because the analytes found in hair after drug use are generally the
parent drug or its lipophilic metabolites, immunoassays developed and intended
for urine testing are not suitable for hair. Immunoassays whose antibodies are
bound to a solid support, such as coated-tube radioimmunoassay or coated-plate
ELISA tests, experience less matrix interference than those which use other means
of separation of bound and free fractions. Homogenous assays are not suitable for
hair testing because the hair matrix frequently interferes in the detection of
the signal. Historically radioimmunoassays for drugs of abuse were first used for
detecting drugs in hair. Currently ELISAs and coated-plate 96 well microplate
EIAs are employed for screening hair digests or extracts for drugs. The optimum
cutoffs for immunoassays for drugs in hair should be chosen based on the analyte
concentration which produces the fewest false positive or false negative results
when applied to tests of hair from known users and non-users of drugs. A hair
immunoassay test at these cutoffs should have a sensitivity and specificity of
better than 90%. The predictive value of the test will depend on the prevalence
of drug use in the tested population. Cutoffs or decision thresholds for
immunoassays used for screening for drugs should not be at the limit of detection
of the assay because that produces a very large incidence of false positives.
Because immunoassays are ligand-binding assays, they have a short range of
linearity with low precision at both ends of the range. In the future,
immunoassays will continue to be used for screening hair and other matrices for
drugs of abuse because they provide rapid, inexpensive automated procedures for
separating negative specimens from those which are suspected of containing drugs.
For forensic purposes, all positive results must be confirmed by an independent
analysis using a procedure based on a different property of the analyte. An
immunoassay test should not be confirmed by a second immunoassay test but by a
chromatographic test performed on a different dissolved or extracted aliquot of
the original specimen.
PMID- 10689578
TI - Analysis of drugs of abuse in hair by automated solid-phase extraction, GC/EI/MS
and GC ion trap/CI/MS.
AB - In our laboratory, analysis of human hair for the detection of drugs of abuse was
first performed in 1995. Initially, requests for hair analysis were few, and it
is only since 1997 that these analyses have become routine. As demand grew, we
developed an automatic solid-phase extraction method; the use of a robot ASPEC
allowed us to drop certain fastidious manipulations, and to treat a large number
of samples at a time. This method is described, along with analysis by gas
chromatography-mass spectrometry (GC/MS) in selected ion monitoring mode (SIM),
for the following drugs: codeine, 6-monoacetylmorphine (6-MAM), morphine,
cocaine, methadone, ecstasy (MDMA) and Eve (MDE). This requires prior
derivatization with propionic anhydride. The different validation parameters,
linearity, repeatability, recovery and detection limits are described, as well as
the application of this method to some real cases. Analysis of these cases is
also performed by an ion trap GC/MS in chemical ionization mode (GC/IT/CI/MS) in
order to demonstrate the usefulness of this technique as a complement to routine
analysis. Analysis by GC/IT/CI/MS indeed avoids the risk of false-positive
results by the identification of metabolites.
PMID- 10689579
TI - Evaluation of cocaine, amphetamines and cannabis use in university students
through hair analysis: preliminary results.
AB - The evaluation of drug abuse in a defined population was performed through
toxicological hair analysis. Hair samples from university students ranging from
18 to 25 years of age were anonymously collected and screened for cocaine,
amphetamines and cannabinoids by radioimmunoassay (RIA). Positive results (cut
off values adopted were 2 ng/mg for cocaine and amphetamines and 0.5 ng/mg for
cannabinoids) were confirmed by GC/MS. Preliminary results showed 19% of positive
results for cocaine on 200 samples analysed. No confirmed positive results were
obtained for amphetamine analysis. RIA technique demonstrated its unsuitability
for cannabinoids preliminary screening on hair, giving a high percent of false
positive results.
PMID- 10689580
TI - Clinical applications of hair testing for drugs of abuse--the Canadian
experience.
AB - During the last 2 decades there has been a substantial increase in illicit drug
consumption in North America. It has been repeatedly shown that the personal
history of drug use is far from being accurate. Fearing legal consequences and
embarrassment of admitted illicit substance use, most users tend to deny or, to
under-report illicit drug consumption. These facts have stressed an urgent need
for a biological marker which does not lose its sensitivity within a few days
after the end of exposure and which may yield a cumulative reflection of long
term exposure to illicit drugs. Hair analysis has emerged as such a marker. A
variety of illicit and medicinal compounds have been shown to be incorporated
into hair including trace metals, barbiturates, amphetamines, opiates,
phencyclidine, cocaine, nicotine and cannabis. Hair analysis for drugs of abuse
provides long-term information on an individual's drug use; its window of
detection is limited only by the length of the hair and typically, ranges from a
week to several months. After establishing and validating several hair tests
during the last decade, we have analyzed over 1000 hair samples for different
drugs of abuse. We used RIA for screening and GC-MS for confirmation of positive
results. The aim of this report is to illustrate the diagnostic usefulness of
hair testing in different age groups (newborns, children, adults) and
circumstances: (criminal cases, athletes, child custody cases, etc.).
PMID- 10689581
TI - Clozapine dose-concentration relationships in plasma, hair and sweat specimens of
schizophrenic patients.
AB - The aim of the present study was to establish an analytical method for the
determination of clozapine in sweat and to determine whether the clozapine level
in hair and sweat were correlated to the daily dose of clozapine delivered to
patients. Twenty-six subjects treated with clozapine at 200-700 mg/day for
refractory psychosis were included in the study. Clozapine was determined in
plasma by liquid chromatography coupled to a diode array detection system, after
extraction with an organic solvent at pH 9.5. Clozapine was extracted from hair
and sweat patches specimens by incubation in methanol overnight at 40 degrees C.
The residues were analyzed by gas chromatography coupled to mass spectrometry in
the electronic impact mode of detection. It was possible to determine clozapine
in concentrations ranging from 30 to 1016 ng/ml in plasma (n = 22), from 0.17 to
34.24 ng/mg in hair (n = 23) and from 49 to 5609 ng/patch in sweat (n = 20).
Preliminary results suggest a lack of correlation between daily regimen of
clozapine and plasma levels of the drug. Therefore, a better dose-concentration
relationship was observed in our study between daily dose and hair concentration
(r = 0.542, P < 7%) or between daily dose and sweat concentration (r = 0.589, P <
6%), but with wide variations for patients at the same posology. However, the
idea of using quantitative drug measurements in hair or sweat to ascertain
whether a patient has taken his treatment exactly as prescribed will remain
inapplicable.
PMID- 10689582
TI - Hair analysis for driving licence in cocaine and heroin users. An epidemiological
study.
AB - Diagnosis of drug exposure is strongly supported by analysis of hair samples. In
the province of Brescia, Italy, for regranting driving license to drug addicts or
occasional abusers, a control programme was adopted including analysis of illicit
drugs in two hair segments (0-3 and 3-6 cm) and in urine. From January 1998 to
April 1999, upon request of the Local Medical Commission, 697 hair samples were
tested in our laboratory. One hundred and eighty subjects resulted positive in
hair for one or two of the controlled drug classes (73.3% for cocaine, 10% for
opiates, 16.7% for both). Positive subjects were classified by residence, age,
sex and license category. Seventy-two subjects were called back after 6-12 months
and submitted to a second hair and urine analysis: in 34 cases the result of the
first analysis was confirmed (19 negatives, 15 positives for one or both drug
classes). Another 37 cases tested positive at the first control and negative at
the second, suggesting the hypothesis that a strict control may have a
significant deterrent function. The high percentage of negative results at the
second control may be explained by the prevalence of cocaine users in the
examined population. Our results allow us to conclude that the strict application
of control rules lead to a decrease of social risk behaviours.
PMID- 10689583
TI - Is there a place for hair analysis in doping controls?
AB - The actual antidoping control rules applied in sports (as established by the
International Olympic Committee and the International Sport Federations) state
that a positive case is chemically established by the unequivocal detection of a
forbidden parent molecule and/or any of its metabolite(s) in urine, no matter the
amounts which were administered and when the drug was taken. Screening is
accomplished most of the time by using GC-MS procedures. These have been
optimized to detect most if not all of the forbidden compounds which are put on a
list. Recently, attempts have been made on scalp hair to demonstrate the value of
this matrix as a possible means for differentiating between therapeutic use and
doping abuse. In particular, GC-mass selective detector and GC-high resolution MS
were successfully applied to treated animals and body-builders for anabolic
agents (steroids and beta-2-agonists) at high sensitivity detection (low ng/g
level). Naturally occurring molecules, like testosterone and its metabolites,
could also be differentiated from their synthetic counterparts. Positive cases
are more often challenged in courts and retrospectivity in time of the drug(s)
intake is becoming an important issue for evaluating the responsibility of the
person. This is can be based on hair analyses if the drugs have been taken at
regular intervals. Stimulants and narcotics are often used in sports like drug of
abuse in the ordinary social contexts. On the other hand, anabolic agents, when
taken to improve the physical performances, follow complex regimens with the
mixing of various formulas and dosages. Scalp hair references ranges for these as
well as for endogenous substances still wait to be established statistically for
competing, well-trained athletes. The incorporation rate into blond or gray hair
is poorer than that of dark colored hair raising the question of individuals
equality against the controls, a very important matter of concern for the sport's
governing bodies. The frequency of hair cutting and short hair cuts necessary to
gain speed in specific sports like swimming are other critical factors. On the
other hands, irregular hair growth, associated with the washout effect through
multiple washing and staining processes over expanded time intervals can cause
concentrating or diluting effects. So far, a minority of prohibited substances
could be detected in scalp hair with the sensitivity and specificity required in
the context of the sport's activities. From the above, clear limitations of the
usefulness of hair analysis in doping control analysis are obvious until a lot
more data relevant to this particular field have been collected.
PMID- 10689584
TI - Pharmacological criteria that can affect the detection of doping agents in hair.
AB - When positive drug results are reported, a common interpretive question posed is
whether or not it is possible to put a quantitative finding into context. A
standard answer to this inquiry is that a positive hair testing result can be
interpreted as meaning that the donor has chronically or repetitively used the
drug identified in the hair, but that chronic or repetitive are not defined in
the same way for all individuals. The Society of Hair Testing published on June
16, 1999, a consensus opinion on the use of hair in doping situations. However,
although accepted in most courts of justice, hair analysis is not yet recognised
by the International Olympic Committee. To be considered as a valid specimen for
doping control, some issues still need to be addressed. The scientific community
has demonstrated significant concern over the proper role that hair drug testing
should serve in toxicological applications. Among the unanswered questions, five
are of critical importance: (1) What is the minimal amount of drug detectable in
hair after administration? (2) What is the relationship between the amount of the
drug used and the concentration of the drug or its metabolites in hair? (3) What
is the influence of hair color? (4) Is there any racial bias in hair testing? (5)
What is the influence of cosmetic treatments? The present report documents
scientific findings on these questions, with particular attention to the
applications of hair in doping control.
PMID- 10689585
TI - Analytical strategy for detecting doping agents in hair.
AB - Lists of banned classes of doping agents are released by the International
Olympic Committee, adopted by other sports authorities and updated regularly,
including the substance classes stimulants, narcotics, diuretics, anabolic
agents, peptide hormones, beta-blockers etc. There are different classes of
restriction: anabolic and masking agents (anabolic steroids, diuretics etc.) are
always banned for athletes regardless of their topical activity (training or
competition) several substances are permitted with certain restrictions (caffeine
below a cut-off value, or inhalation of some beta 2 agonists) beta-blockers are
prohibited in competitions of certain sports disciplines the majority of the
substances (stimulants, narcotics etc.) is prohibited during competitions, so
that they do not have to be analysed in out-of-competition samples. A
differentiation between training and competition period is impossible by means of
hair analysis due to the uncertainty of (especially short-term) kinetic
considerations related to hair growth. Therefore, the analytical identification
of doping relevant substances in hair is not always a sufficient criterion for a
doping offence and the identification of stimulants, beta-blockers etc. in hair
would be entirely irrelevant. The most interesting target substances are
certainly the anabolic agents, because their desired action (enhanced muscle
strength) lasts longer than the excretion, leading to sophisticated procedures to
circumvent positive analytical results in competition control. Besides the
analysis of out-of-competition control samples, the long term detection of
steroids in hair could provide complementary information. An analytical approach
to the identification of exogenous steroids in hair requires consideration of the
presence of many other steroids in the hair matrix interfering the analysis at
trace levels, and of a limited chemical stability. The analysis of endogenous
steroids in hair appears to be even more complicated, because the possibility of
many biotransformation reactions from (into) other precursors (metabolites) has
to be taken into account. Precursor substances of anabolic steroids (especially
esters as application forms) are very promising analytical targets of hair
analysis, because they can only be detected after an exogenous intake. The
quantitative evaluation of active parent compounds like testosterone (which is
actively involved in physiological processes of hair growth) in hair is still
controversial. Clinical applications under reproducible conditions can be useful,
but the biovariability of these parameters will probably prevent the definition
of acceptable cut-off levels as a criterion of abuse.
PMID- 10689586
TI - Hair analysis and detectability of single dose administration of androgenic
steroid esters.
AB - Detection of anabolic steroids in hair samples has been possible only in fatal
cases or in cases of high-continuous dosages. In order to verify the possibility
of detecting an acute administration, a sensitive and specific assay has been
developed for the simultaneous determination of testosterone, nandrolone and some
of their esters in hair. The analytes were extracted from finely cut hair with
methanol-trifluoroacetic acid overnight. After the incubation, the mixture was
evaporated to dryness, redissolved and extracted with hexane. The dried organic
layer was silanised and analysed by GC-MS and GC-MS-MS. A sensitivity of at least
20 pg injected was obtained for all the analytes. In guinea pigs treated with a
single intramuscular dose of 10 mg/kg nandrolone decanoate, neither nandrolone
decanoate nor nandrolone were found in hair collected after 13 days, while both
compounds were clearly detectable after four repeated doses (each dose every 3-4
days) of 20 mg/kg nandrolone decanoate. Neither nandrolone decanoate nor
nandrolone could be detected in hair from a male healthy volunteer 1 month after
treatment with 50 mg nandrolone decanoate, while his urine still tested highly
positive for the main nandrolone metabolite (> 100 ng/ml). Testosterone esters
could not be detected in hair of healthy subjects collected respectively 3, 2 and
1 month after a single intramuscular administration of 250 mg testosterone
enanthate (five subjects), a single intramuscular coadministration of 25 mg
testosterone propionate plus 110 mg testosterone enanthate (one subject), or a
single oral administration of 120 mg testosterone undecanoate (three subjects).
Otherwise, hair analysis revealed an increase of testosterone concentration
corresponding to the period of treatment. Analysis of blood and urine samples
confirmed the absorption of those compounds. At the sensitivity achieved by the
present method, no detection of nandrolone, nandrolone decanoate nor testosteron
esters in hair seems to be obvious after a single dose administration.
PMID- 10689587
TI - Compared interest between hair analysis and urinalysis in doping controls.
Results for amphetamines, corticosteroids and anabolic steroids in racing
cyclists.
AB - In France during a famous bicycle race, the newspapers documented the degree in
which doping seemed to be supervised in some teams by managers and doctors. Use
of anabolic steroids and other substances was officially banned in the mid
seventies by sports authorities. This policy has been enforced through urine
testing before competition. It is well known, however, that a latency period is
all that is necessary to defeat these tests. Nevertheless, hair analysis could be
a promising tool when testing for periods that are not accessible to urinalysis
any more. We have developed different sensitive methods for testing hair for
amphetamines, anabolic steroids and their esters and corticosteroids. For
amphetamines, 50 mg of hair were digested with 1 M NaOH, extracted with ethyl
acetate, derivatized with TFA and analyzed by gas chromatography positive
chemical-ionization mass spectrometry. For corticosteroids, 50 mg of powdered
hair were treated with methanol in an ultrasonic bath and subsequently purified
using a C18 solid phase extraction column. Analysis was realized by high
performance liquid chromatography coupled to electrospray-ionization tandem mass
spectrometry. For anabolic steroids and their esters, 100 mg of powdered hair
were treated with methanol in an ultrasonic bath for extraction of esters, then
alkaline digested with 1 M NaOH for an optimum recovery of other drugs. The two
liquid preparations were subsequently extracted with ethyl acetate, pooled, then
finally highly purified using a twin solid phase extraction on aminopropyl and
silica cartridges. Residue was derivatized with MSTFA prior to injection.
Analysis was conducted by gas chromatography coupled to a triple quadrupole mass
spectrometer. Thirty cyclists were sampled and tested both in hair and in urine.
Amphetamine was detected 10 times in hair (out of 19 analyses) compared to 6
times in urine (out of 30 analyses). Corticosteroids were detected 5 times in
hair (methylprednisolone 1 case, triamcinolone acetonide 3 cases and
hydrocortisone acetate 1 case) in hair (out of 12 analyses) compared to 12 times
(triamcinolone acetonide 10 cases and betamethasone 2 cases) in urine (out of 30
analyses). Anabolic steroids were detected twice (nandrolone 1 case, and
testosterone undecanoate 1 case) in hair (out of 25 analyses) compared to none in
urine (out of 30 analyses).
PMID- 10689588
TI - Identification of ten corticosteroids in human hair by liquid chromatography
ionspray mass spectrometry.
AB - This paper describes a screening procedure based upon high-performance liquid
chromatography-ionspray mass spectrometry for the identification of ten
corticosteroids in human hair: triamcinolone, prednisolone, prednisone,
methylprednisolone, cortisone, cortisol, beta- and dexamethasone, flumethasone
and beclomethasone. Hair strands were washed in methylene chloride, pulverized in
a ball mill and 50 mg of the powdered hair were incubated in 1 ml Soerensen
buffer, pH 7.6 for 16 h at 40 degrees C, in presence of 50 ng cortisol-d3 used as
internal standard. Purification of the incubation medium was achieved on SPE C18
Isolute extraction columns. The eluates were evaporated to dryness and
resuspended in 30 microliters MeOH before analysis by HPLC-IS-MS in positive and
negative modes of detection. The validation parameters were found satisfactory
for a corticosteroid screening procedure. The correlation coefficient of the
calibration curve ranged from 0.939 to 0.997, showing linearity between 0.1 and
10 ng/mg, excepted for beclomethasone which was between 0.2 and 10 ng/mg.
Extraction recovery at 4 ng/mg ranged from 43.2 to 85.7%. Repeatability (CV
values) at 4 ng/mg ranged from 6.1 to 17.5%. The limits of detection ranged from
0.03 to 0.17 ng/mg for a signal-to-noise ratio of 2. The detection of prednisone
and beclomethasone in three hair specimens obtained from forensic and clinical
cases have documented corticosteroids incorporation into human hair.
PMID- 10689589
TI - The hair analysis proficiency testing program of the French Society of Analytical
Toxicology.
AB - In an effort to improve laboratories performing hair analysis in forensic cases,
the French Society of Analytical Toxicology (S.F.T.A.) has implemented a
proficiency testing program since 1992. Actually about 10 laboratories are
participating. Each survey is dedicated to one analyte or one pharmacological
class: opiates (6-monoacetylmorphine, morphine and codeine), cocaine and
benzoylecgonine, tetrahydrocannabinol, buprenorphine and norbuprenorphine, beta
blockers (metoprolol, atenolol), beta 2-agonists (salbutamol, clenbuterol).
Animal hair was tested for clenbuterol. Prior to sending, hair samples were
reduced to a powdered form, well mixed to ensure homogeneity, and then tested by
GC/MS or HPLC/MS. Results confirm those obtained in a preliminary study on
opiates and cocaine analysis in hair: a common analytical procedure has to be
used by all the participants, including hydrolysis of hair. It is essential to
work on authentic drug-positive hair samples and not on spiked samples.
Participation at this program is free of charge and considered as an educational
tool. Comparison of the results with those of other laboratories in Europe and
USA shows that the analytical methods used during this program are in accordance
with all the other procedures.
PMID- 10689590
TI - Implications of recent findings in posttraumatic stress disorder and the role of
pharmacotherapy.
AB - Recent evidence suggests that an etiologic model of posttraumatic stress disorder
(PTSD) must include both vulnerability factors (presumably related to
dysregulation of stress responses and/or failure of normal restitutive mechanisms
following trauma) and factors related to trauma severity. The fact that rates of
PTSD increase with the severity of trauma suggests that normal adaptive
mechanisms may become overwhelmed even in the absence of vulnerability factors.
Consistent with this view, efforts to demarcate normative from disordered
reactions to severe trauma, such as the new diagnosis of acute stress disorder,
have had limited success. Debate over the moral and scientific implications of
receiving a trauma-related diagnosis has further complicated the issue and
perpetuated a false dichotomy concerning normative responses. The literature on
clinical trials in PTSD is reviewed. The range of treatment responses, and the
categorical breadth of compounds studied, requires interpretation before the
literature as a whole can be understood. One of the many limitations of this new
literature is the absence of treatment-outcomes research on individuals with the
common comorbidity of substance abuse. The most recent findings with selective
serotonin-reuptake inhibitors and related compounds indicate a more optimistic
outlook for pharmacological treatment of PTSD than was suggested by earlier
trials. Given these observations, investigators will hopefully be encouraged to
pursue study and development of treatment models that include both
pharmacological and psychosocial interventions.
PMID- 10689591
TI - The efficacy of newer antidepressants in the treatment of chronic pain: a review
of current literature.
AB - Tricyclic antidepressants have been extensively studied and frequently used in
the treatment of various chronic pain syndromes. Newer antidepressants, namely
fluoxetine, sertraline, paroxetine, fluvoxamine, citalopram, trazodone,
nefazodone, bupropion, mirtazapine, and venlafaxine, have also been considered
for this indication, although they have been less extensively studied. This
article reviews the available publications, including placebo-controlled trials,
other outcome studies, and case reports, pertaining to the use of these
medications for chronic pain. Although some of these newer compounds may be
effective for specific types of pain, making generalizations regarding their use
as analgesics is difficult, given the limitations of existing data. Additional
observations based on the data are presented in the hope that they may help to
guide further research and clinical use.
PMID- 10689592
TI - Huntington's disease and its association with psychopathology.
AB - We review several aspects of Huntington's disease (HD), with a special focus on
the psychopathological manifestations often identified in patients with this
disorder. We discuss the evidence for a higher-than-average prevalence of
psychosis, depression, and obsessive-compulsive disorder (OCD) in individuals
with HD or at risk for the illness and analyze the possible significance of these
findings. Particular emphasis is placed on OCD, in view of the neuroanatomical
impairment that this condition shares with HD, the symptomatic similarities
between these disorders, and recent findings of an excess of OCD in HD-affected
families. We hypothesize that precise characterization of the psychiatric status
of some HD patients showing psychopathological manifestations and their families
might help to distinguish different clinical subtypes of the disorder. This
approach could hold promise in improving the management of HD in the future.
PMID- 10689593
TI - It takes a village: caring for a traumatized art student.
PMID- 10689594
TI - A model for the assessment of violence.
PMID- 10689595
TI - Problem-based learning and psychiatry residency education.
PMID- 10689596
TI - [Dexpanthenol for dry skin. Regeneration of damaged permeability barrier of the
skin].
PMID- 10689597
TI - [Testosterone substitution in male senescence].
PMID- 10689598
TI - Knowledge development in health & social work.
PMID- 10689599
TI - Culturally sensitive social work practice with Arab clients in mental health
settings.
AB - Several culturally specific practical considerations should inform social work
interventions with ethnic Arab peoples in Arab countries or in Western nations.
These include taking into account gender relations, individuals' places in their
families and communities, patterns of mental health services use, and, for
practice in Western nations, the client's level of acculturation. Such aspects
provide the basis for specific guidelines in working with ethnic Arab mental
health clients. These include an emphasis on short-term, directive treatment;
communication patterns that are passive and informal; patients' understanding of
external loci of control and their use of ethnospecific idioms of distress; and,
where appropriate, the integration of modern and traditional healing systems.
PMID- 10689600
TI - Risk factors associated with PTSD and major depression among Cambodian refugees
in Utah.
AB - The study reported in this article is a secondary analysis of data collected from
a random sample of 124 Cambodian adults, ages 18 to 76 years. Participants were
interviewed about their mental health status and factors associated with a
diagnosis of posttraumatic stress disorder (PTSD) or major depression. From
analysis of the data, the following risk factors were identified with PTSD and
depression: experiencing a greater number of war traumas increased the risk of
both PTSD and major depression; experiencing a greater number of resettlement
stressors during the past year increased the risk of both PTSD and major
depression; and having financial stress increased the risk of major depression.
PMID- 10689601
TI - Depression among victims of south Mississippi's methyl parathion disaster.
AB - Human-induced disasters have long been considered responsible for a wide array of
physiological, psychological, and economic distress. This study examined
depressive symptoms among victims of south Mississippi's methyl parathion
disaster. Results indicated that irrespective of the level of methyl parathion
contamination in respondents' dwellings, more than half the victims interviewed
reported depressive symptoms at levels suggesting probable clinical depression.
Those at greatest risk of depressive symptoms were people who had been exposed to
the neurotoxin for the longest period of time, among whom there was an
overrepresentation of women and African Americans. Despite high statistical
levels of depression, few victims used mental health services. Implications for
social work's response to human-induced disasters are provided.
PMID- 10689602
TI - Adolescents with sickle cell disease: determinants of support group attendance
and satisfaction.
AB - Support groups have the potential to mitigate some of the developmental and
condition-specific psychological and social issues common to sickle cell disease
(SCD), yet little is known about how adolescents with SCD view and use these
groups. As part of a larger study, 79 adolescents with SCD completed
questionnaires assessing reasons for attending or not attending support groups,
level and type of help received from group participation, group satisfaction, and
attendance. This article reports on findings descriptively. Professionals can
enhance their effectiveness as providers of social and mental health services by
understanding the role that support groups play in the overall well-being of
adolescents with SCD.
PMID- 10689603
TI - A deconstructive turn in chronic pain treatment: a redefined role for social
work.
AB - Chronic pain treatment programs in North America are based predominantly on a
behavioral science model of contingency management, whereby the focus of
treatment is directed toward the psychological aspects of pain. Treatment
objectives are designed to eliminate reinforcing environmental contingencies,
thus changing pain behavior and reestablishing well behavior. The purpose of this
article is to displace the contingency management model with deconstruction and
thus present an alternative conceptualization based on the experiences of chronic
pain sufferers. Social work's value base of self-determination and empowerment
upholds these challenges to the predominant treatment model. Alternative social
work interventions are explored.
PMID- 10689604
TI - The power to choose: supports for families caring for individuals with
developmental disabilities.
AB - In an exploratory study of family support services in Massachusetts, three focus
groups were convened to obtain the perspectives of parents caring for individuals
with developmental disabilities and living at home. This article summarizes key
themes that emerged from the group discussions: effects of family supports on
family life, flexibility of supports, barriers, unmet needs, and recommendations
for change. Social workers and health care professionals can enhance the well
being of people with developmental disabilities and their families by addressing
the needs of the entire family, facilitating family choice and control of
supports, and helping families navigate the complex service system.
PMID- 10689606
TI - Quality of life and mental health services.
PMID- 10689605
TI - A "society for all ages": saving Social Security and Medicare.
PMID- 10689607
TI - Subjective quality of life in female in-patients with depression: a longitudinal
study.
AB - This study investigated Subjective Quality of Life (SQOL) in 42 women with
depression, 70 women with alcoholism, and 73 women with schizophrenia within 3
weeks after hospital admission. Twenty-eight of the depressive patients were re
examined after 6 months. SQOL was assessed using the German version of the
Lancashire Quality of Life Profile. On average, depressive women expressed
dissatisfaction with life as a whole and with 4 out of 8 life domains, and had a
lower SQOL than the other two diagnostic groups. Differences remain statistically
significant when the influence of age and anxiety/depression is controlled for.
SQOL in depressive women improved significantly within the follow up period.
Positive SQOL change was moderately correlated with an improvement of depressive
symptoms. The results indicate that depressive women after hospital admission
express an unusually low SQOL, which seems to have some diagnostic specificity
and improves over time. Changes in depressive symptoms do not fully explain SQOL
changes.
PMID- 10689608
TI - Predictors of subjective quality of life in schizophrenic patients living in the
community. A Nordic multicentre study.
AB - As part of a Nordic multi-centre study investigating the life and care situation
of community samples of schizophrenic patients the aim of the present part of the
study was to examine the relationship between global subjective quality of life
and objective life conditions, clinical characteristics including psychopathology
and number of needs for care, subjective factors such as satisfaction with
different life domains, social network, and self-esteem. A sample of 418 persons
with schizophrenia from 10 sites was used. The results of a final multiple
regression analysis, explaining 52.3% of the variance, showed that five
subjective factors were significantly associated with global subjective quality
of life, together with one objective indicator, to have a close friend. No
clinical characteristics were associated with global subjective quality of life.
The largest part of the variance was explained by satisfaction with health, 36.3%
of the variance, and self-esteem, 7.3% of the variance. It is concluded that the
actual relationship between objective life conditions and subjectively
experienced quality of life still remains unclear. Furthermore, it seems obvious
that personality related factors such as self-esteem, mastery and sense of
autonomy also play a role in the appraisal of subjective quality of life, which
implies that factors like these are important to consider in clinical and social
interventions for patients with schizophrenia in order to improve quality of life
for these persons.
PMID- 10689609
TI - Subjective quality of life, psychopathology, satisfaction with care and insight:
an exploratory study.
AB - We have investigated the determinants of global subjective quality of life
(GSQOL) using data from a controlled trial of intensive case management for the
severely mentally ill. In a multiple regression analysis depression, age,
objective quality of life and domain-specific quality of life together explained
59% of the variance in GSQOL. GSQOL was not significantly correlated with
measures of positive psychotic symptomatology, insight or attitudes to treatment
but was correlated with satisfaction with care (r = .21, p = .011). Change in
GSQOL over 18 months was correlated with change in domain-specific quality of
life (r = -.45, p = .002) and depression (r = -.43, p = .01): multiple regression
analysis confirmed that both variables had an independent effect on change in
GSQOL.
PMID- 10689610
TI - Quality of life and new antipsychotics in schizophrenia. Are patients better off?
AB - The recent introduction of several antipsychotic medications has raised
expectations for better pharmacological management of schizophrenia. Although
conventional and new neuroleptics (Risperidone, Olanzapine, Seroquel and soon to
be released Ziprasidone) are generally comparable in terms of efficacy; the new
antipsychotic medications possess a better side-effects profile and are overall,
much better tolerated. The reintroduction of Clozapine as an effective
antipsychotic for treatment refractoriness has also improved management for a
segment of the schizophrenic population who failed to respond adequately to other
antipsychotic medications. Such increased benefits from new antipsychotic
medications come with a higher acquisition cost that has somewhat strained the
historically low psychiatric budgets. The question then was whether the expected
benefits of the new antipsychotics can offset the high cost of these medications
in the long-term. In that context, quality of life assessment has provided a tool
for the comparative analysis of new and conventional antipsychotic medications,
particularly regarding their impact on functional status and satisfaction. In a
recently concluded study, we demonstrated that the new antipsychotic medications
are subjectively much better tolerated and have a more favourable impact on
quality of life compared with conventional neuroleptics. The ultimate question is
whether such favourable benefits can translate in the future into better
compliance with medications and improved long-term outcomes.
PMID- 10689611
TI - Therapeutic relationships and quality of life: association of two subjective
constructs in schizophrenia patients.
AB - Subjective quality of life is an important criterion in outcome evaluation that
has been well-researched in psychiatry. By comparison, the therapeutic
relationship which may also be subjectively assessed has been relatively
neglected as an outcome criterion although it has predictive power in relation to
outcome. This exploratory study investigated subjective quality of life and
therapeutic relationships in first-admission (N = 90) and long-term (N = 168)
schizophrenia patients, each at two points of time. The follow-up period was 9
months for the first-admission sample and 1.5 years for the long-term sample. A
significant relationship was found between global assessments of quality of life
and therapeutic relationships in long-term, but not in first-admission patients.
This finding was consistent at both assessments, suggesting that therapeutic
relationships may become more central to quality of life in long-term care
situations and that patients' views of this relationship are increasingly
embedded in their overall appraisal of life.
PMID- 10689612
TI - Measuring quality of life in secure care: comparison of mentally ill and
personality disordered patients.
AB - Improving quality of life for patients is emerging as a legitimate goal for UK
inpatient forensic mental health services. The Lancashire Quality of Life Profile
(LQOLP), which has been used widely to measure well-being in community settings,
was trialed on an inpatient population being cared for under conditions of high
security. Two groups of male patients, drawn from within the same institution but
with markedly different clinical conditions, i.e. schizophrenia (N = 47) and
personality disorder (N = 48), were interviewed using the LQOLP. Although both
groups had been cared for under largely similar environmental conditions over
similar lengths of time (9.5 years), the subjective global well-being of the two
groups differed systematically as did other objective and subjective well-being
measures. However, analysis found that the variations in global well-being could
not be attributed readily to factors covered by the interview, including either
current mood or personality. Possible reasons for these findings and implications
for the use of the LQOLP under conditions of high security are discussed.
PMID- 10689613
TI - The impact of the interviewer-interviewee relationship on subjective quality of
life ratings in schizophrenia patients.
AB - Subjective quality of life (SQOL) ratings are usually based on interviews. This
study examined in which way patients' ratings differ depending on whom they are
interviewed by. SQOL was assessed in 78 schizophrenia patients in an out patient
clinic and in sheltered living arrangements. Using patients randomly allocated to
two interview situations: one group was interviewed by external researchers, the
other group by their case managers. On average, more favourable ratings were
elicited by case managers. Some of the differences were statistically significant
and substantial in size. Yet, opposing differences were also found regarding some
life domains in one group. It may be concluded that a significant impact of the
interviewer-interviewee relationship on SQOL ratings may exist, but that it is
not consistent, unidirectional and uniform regarding life domains and across
different settings and samples.
PMID- 10689614
TI - Rehabilitation programmes and quality of life in severe mental illness.
AB - Quality of life is increasingly identified as a key outcome measure for
evaluating the efficacy of community mental health services and novel
antipsychotics. However, there is a relative paucity of research on the impact of
rehabilitation programmes on quality of life. This report outlines the results of
two 'naturalistic' studies carried out in a catchment area psychiatric service to
evaluate the benefits associated with a supported employment programme and a
psychosocial/educational intervention. The findings suggest that outpatient based
programmes which provide opportunities for vocational or prevocational
rehabilitation may have significant quality of life benefits for individuals with
severe mental illness.
PMID- 10689615
TI - An evaluation of the impact of clubhouse membership on quality of life and
treatment utilization.
AB - A group of clubhouse users matched with similar patients (not clubhouse users) in
a neighbouring area were compared in terms of quality of life (Lancashire Quality
of Life Profile), service utilization and treatment costs over a two year period.
The clubhouse group achieved a reasonable employment status and good social
relationships, and advantages in subjective well-being favoured the clubhouse
group. Over two years the pattern of service utilization and costs also favoured
the clubhouse group. When the two groups were disaggregated for employment status
the group with least treatment utilization and lowest costs was the employed
clubhouse group.
PMID- 10689617
TI - [Corticosteroid hormones: mechanisms involved in the recognition of aldosterone
by mineralocorticoid receptors].
AB - Aldosterone and cortisol, the major mineralocorticoid and glucocorticoid hormones
in humans, are structurally very closed. Both hormones bind to the
mineralocorticoid receptor (MR) with the same affinity. Nevertheless MR is
preferentially activated by aldosterone, suggesting that the binding of these two
hormones to MR involved some distinct contacts. We constructed a tridimensional
model of the ligand-binding domain of the human MR, by taking as a template the
structural data of the retinoid receptor associated with its ligand. The MR model
allowed the identification of several residues involved in the interaction with
aldosterone and cortisol. The residues Gln 776 and Arg 817 make hydrogen bonds
with the 3-keto function and the residue Asn 770 with the C21-hydroxyl group.
Analyses of the wild type and mutant MRs activities in response to
corticosteroids bearing hydroxyl groups at various steroid skeleton position led
to the following conclusions: 1) the interaction between the residue Asn 770 and
the C21-hydroxyl group of corticosteroids is determinant for stabilizing the
active MR conformation and 2) the stability of this conformation is enhanced by
the 11-18 hemiketal group of aldosterone whereas it is decreased by the 11 beta-
and 17 alpha-hydroxyl groups of cortisol. These results are discussed in the
light of a model for the MR activation process.
PMID- 10689616
TI - [The head inducer Cerberus in a multivalent extracellular inhibitor].
AB - Cerberus encodes for a secreted protein which when overexpressed ventrally in a
Xenopus embryo induces head differentiation without trunk (Bouwmeester et al.,
1996). We have recently shown that Cerberus can bind BMP-4 (Bone Morphogenetic
Protein-4), Xnr-1 (Xenopus Nodal-related 1) and Xwnt-8 in the extracellular space
(Piccolo et al., 1999). We present here studies showing that Cerberus does not
have a receptor nor a dedicated transduction pathway but rather acts as an
extracellular inhibitor. Our results suggest that the action of Cerberus in head
induction can be explained by an inhibitory activity upstream of the Nodal
related and BMP-4 receptors. In addition, using dominant negative receptor
mutants which block both the Xnr-1 and BMP-4 transduction pathways, we show that
this double inhibition is sufficient for head induction in ventral mesoderm
explants.
PMID- 10689618
TI - [Functional interaction of HSP90 with steroid receptors].
AB - Hsp90 (Heat Shock Protein 90) is a component of the inactive and metastable
hetero-oligomeric structure of steroid receptors. Recent data on Hsp90 structure
and function as a stress protein and dedicated molecular chaperone are here
reviewed with a particular focus on Hsp90 chaperone cycle interfering with
steroid receptor action. The dual role of Hsp90 as a positive and negative
modulator of steroid receptor function is considered along the activation
desactivation process of the receptors. It is proposed that Hsp90 chaperone
machinery assists the receptor during its synthesis thus avoiding collapse and
facilitating an open structure able to bind ligand efficiently. Moreover, it is
suggested that Hsp90 may help the folding of the hydrophobic core of the receptor
around the ligand and finally Hsp90 may chaperone the receptor after the
dissociation of the ligand.
PMID- 10689619
TI - [Interactions between the glucocorticoid receptor and transcription factors].
AB - Transcriptional regulation by glucocorticoids is mediated through an
intracellular glucocorticoid receptor which transmits hormone signal to the
nucleus. Two types of mechanisms have been attributed for the hormonal regulation
of gene promoters. The first one requires DNA binding of the activated receptor
to a specific element called GRE (Glucocorticoid Response Element) found in the
promoter regions of target genes and the second one involves a direct cross-talk
of the GR with transcription factors. Both mechanisms are dependent on the
promoter configurations, their chromatin structure or the components of the
transcriptional complexes involved in the interaction with the GR. These distinct
features specify the activity of the GR as a repressor or activator of
transcription.
PMID- 10689620
TI - [Glucocorticoids and acute phase proteins].
AB - Glucocorticoids as well as acute phase proteins participate in non-specific host
defence as well as in restoring host integrity after injury. Plasma levels of
both compounds augment during the inflammatory reaction. However, glucocorticoids
also have physiological effects that share similar molecular mechanisms with the
family of steroids. During the inflammatory reaction, and for participating in
host defense, glucocorticoids, together with augmented cytokines, use new
signalling pathways. In doing so, they participate in the positive or negative
control of inflammatory mediator synthesis. For example, they induce the
synthesis of acute phase proteins in synergy with interleukin 6, interleukin 1
and TNF alpha.
PMID- 10689621
TI - [Interactions between glucocorticoids and anti-inflammatory peptides].
AB - Both pro- and anti-inflammatory mediators regulate the anti-inflammatory actions
of glucocorticoids, in part by modifying the binding of glucocorticoids to
specific receptors. For instance, somatostatin has been shown to increase
glucocorticoid binding and signaling in macrophages. The mechanism of this
regulation does not require an increased expression of glucocorticoid receptors
but, rather, a stabilization of glucocorticoid receptor-associated heat shock
protein 90. This is related to a decrease in calpain activity. Thus calpain
inhibition may offer a new and exciting possibility for enhancing the anti
inflammatory efficiency of glucocorticoids.
PMID- 10689622
TI - [Temporal regulation of gene expression].
AB - Molecular biology gives a static--not a dynamic--vision of the mechanisms
regulating gene expression. Genetics already gave to time a limited place in the
explanation of living phenomena. Such a static vision is supported by the
techniques--such as X-ray crystallography--used by the biologists. However time
is an important parameter in the control of gene expression during the cellular
response to external signals, during life and aging of organisms or even in the
succession of living forms which takes place in evolution. Models are slowly
moving, due to the eruption of new technologies giving access to the fast events
which occur inside living cells. A new dynamic vision is progressively replacing
the old one. The consequences of these changes on the form of the future biology
remain still unknown.
PMID- 10689623
TI - [Management of time by the cell and by the organism].
AB - Time-dependent regulations of cells and organisms can be analysed at different
levels. One of these levels is the periodicity of cell functions such as cell
division, metabolic processes (generation of ATP by glycolysis or oxidative
mitochondrial processes) and the biosynthesis of cell constituents. Studies
carried out on unicellular eukaryotes revealed the periodic, oscillatory nature
of most of these processes. Time constants of these reactions vary from
nanoseconds to hours-days, necessitating coupling mechanisms. Comparative studies
revealed the coupling of the rapid processes (mitochondrial ATP generation) to
the slower rhythms of the biosynthetic processes of macromolecules. Adenine
nucleotides are involved in the coupling mechanisms between rapid and slow
processes ("the slow dance of life to the music of time"). The mechanisms
underlying these rhythmic processes involve either key allosteric regulatory
enzymes (PFK for glycolysis) or "desensitization" of receptors by phosphorylation
dephosphorylation. At the organismic level the study of rhythmic processes is
illustrated by the periodicity of heart beats, shown to exhibit multifractality,
following apparently the formalism of deterministic chaos. Another example is the
rhythmic oscillatory discharges of neuronal networks. The existence of
subrhythmes mostly of epigenetic nature, facilitated probably the progressive
adjustment of cells during evolution to the slow increase of day time since the
separation of the moon from the earth. We analysed the mechanisms underlying the
decline of these processes during aging. Loss of receptors or/and their
uncoupling from their transmission pathway appear to be involved in most of these
processes of decline. One conclusion of this review is the importance of
epigenetic mechanisms both in the genesis and in the decline of these rythmic
processes involved in time keeping by the cell.
PMID- 10689624
TI - [Time of consciousness, consciousness of time].
AB - Time shapes our behavior: we must estimate the duration of events in our
environment in order to anticipate changes and time our activity in function of
these changes. However, there is no sensory modality devoted to the perception of
time, therefore the question is to know which mechanisms underlie the
consciousness that time flows and allow us to estimate time precisely. This
article proposes a brief overview of psychological, neuropsychological and brain
imaging studies which rely on theoretical models postulating the existence of an
internal timer. These studies examine the different components--time base,
counter and memory--of this timer: particularly they are aimed at characterising
the relationships between the evolution of these components with age or their
pathological alterations and changes in temporal judgements. They also attempt to
specify the neural bases of these components. From this brief overview comes the
idea that, if an internal timer exits, it does not mark objective time but a
multitude of subjective times.
PMID- 10689625
TI - [Regulation of cell activity by the extracellular matrix: the concept of
matrikines].
AB - The activity of connective tissue cells is modulated by a number of factors
present in their environment. In addition to the soluble factors such as
hormones, cytokines or growth factors, cells also receive signals from the
surrounding extracellular matrix (ECM) macromolecules. Moreover, they may degrade
the ECM proteins and liberate peptides which may by themselves constitute new
signals for the surrounding cells. Therefore, an actual regulation loop exists in
connective tissue, constituted by peptides generated by ECM degradation and
connective tissue cells. The term of "matrikine" has been proposed to designate
such ECM-derived peptides able to regulate cell activity. In this review, we
summarize some data obtained in our laboratory with two different matrikines: the
tripeptide glycyl-histidyl-lysine (GHK) and the heptapeptide cysteinyl
asparaginyl-tyrosyl-tyrosyl-seryl-asparaginyl-serine (CNYYSNS). GHK is a potent
activator of ECM synthesis and remodeling, whereas CNYYSNS is able to inhibit
polymorphonuclear leukocytes activation and decrease the invasive capacities of
cancer cells.
PMID- 10689626
TI - [Role of lipid second messengers involved in the response of leukemic cells to
anticancer drugs].
AB - Simple clinical observation suggests that while anti-leukemia agents are
efficient at eradicating blasts cells in terminal division, as illustrated, in
the case of acute myeloid leukemia, by the high complete remission rate (70%);
these agents are relatively inept at eliminating leukemic myeloid progenitors as
suggested by the high level of recurrence. This interpretation underlines the
apparently natural chemoresistance of cells which compose the myeloid leukemia
progenitor compartment. Over the past few years, several studies have shown that
similar cellular damage can lead to divers effects such as rapid apoptotic death,
differed mitotic death, or a transitory cytostatic effect. Cell response to
damage is regulated by a complex and highly regulated network of intracellular
signals including cell death signals mediated by ceramide and cell survival
signals mediated (at least in part) by diacylglycerol and phosphoinositide-3
phosphates. Cellular fate relies on the balance between these two signaling
pathways. This hypothesis opens several prospects on pharmacological manipulation
aimed at either favoring cell death or at conferring resistance to anti-cancer
agents.
PMID- 10689627
TI - Otilonium bromide: a selective spasmolytic for the gastrointestinal tract.
AB - Experimental studies have shown that otilonium bromide (OB) inhibits both
baseline and chemically or physically stimulated gastrointestinal motility. The
spasmolytic activity of OB in the gastrointestinal tract occurs at doses that do
not affect gastric secretion or produce typical atropine-like side-effects. The
mechanism of action is composite: interference with calcium ion movement from
intra- and extracellular sites; blockade of calcium channels; and binding to
muscarinic receptors and tachykinin neurokinin-2 receptors. Pharmacokinetic
studies have shown that OB accumulates in the lower intestine and has poor
systemic absorption. Clinical studies have confirmed OB as a potent spasmolytic
drug with a good tolerability profile. Studies in patients with irritable bowel
syndrome demonstrated OB to be superior to placebo and reference drugs in
parameters such as pain, abdominal distension and motility. The composite and
local mechanism of OB action reduces hypermotility and modulates visceral
sensation: factors thought to be responsible for pain improvement recorded in
clinical trials. The compound is marketed worldwide and no serious adverse events
have been reported as yet, confirming its excellent tolerability.
PMID- 10689628
TI - Efficacy and safety of trazodone versus clorazepate in the treatment of HIV
positive subjects with adjustment disorders: a pilot study.
AB - The efficacy of trazodone and clorazepate to relieve anxiety and depressive
symptoms in 21 HIV-positive subjects with adjustment disorders was determined in
a 28-day single-centre, randomized, double-blind study. Subjects were evaluated
using the Hospital Anxiety and Depression Scale, the Revised Symptom Checklist,
the European Organization for Research and the Treatment of Cancer Quality of
Life Questionnaire, and a binary criterion based on the Clinical Global
Impression. The incidence of successful treatment was 80% for trazodone compared
with 64% for clorazepate; the sample number was too small to establish a
significant difference. Bayesian analysis revealed the probability of making a
wrong decision in prescribing trazodone rather than clorazepate reduced from 35%
to 18% in this small sample. Clinical evaluations using the different scales
suggest some benefit from trazodone, although this was not significant. Safety of
both treatments was similar. Trazodone is devoid of the risk of abuse and
dependence, and may be a valuable alternative to benzodiazepines for the
treatment of HIV-related adjustment disorders.
PMID- 10689629
TI - The effect of cross-linked hyaluronate hydrogel on the reduction of post-surgical
adhesion reformation in rabbits.
AB - The effects of cross-linked hyaluronate hydrogel and liquid sodium hyaluronate on
post-surgical adhesion reformation were examined using a rabbit model. Primary
adhesions in the ileocaecal region of Japanese white rabbits were induced by
mechanical and chemical irritants during laparotomy. After 1 month the primary
adhesions were lysed by microsurgery and cross-linked hyaluronate hydrogel or
liquid sodium hyaluronate was applied to the lysed lesions. After 10-14 days the
area of adhesion reformation was measured to assess any inhibitory effect of the
test materials. Rabbits treated with cross-linked hyaluronate hydrogel showed a
significant reduction in adhesion reformation area compared with liquid sodium
hyaluronate or physiological saline treatment, and the area reduced to (mean +/-
standard deviation) 0.6 +/- 1.95% of the original lesion. In a separate study,
histological evaluation of rabbits treated with cross-linked hyaluronate hydrogel
revealed a better healing pattern and a lower inflammatory response compared with
controls. All these findings suggest cross-linked hyaluronate hydrogel may be a
valuable anti-adhesion material to prevent post-surgical adhesion in abdominal or
pelvic surgery.
PMID- 10689630
TI - Use of fibrin adhesive to reduce post-surgical adhesion reformation in rabbits.
AB - Following surgery on fallopian tubes, the development of adhesions is a natural
consequence of wound healing and may result in infertility. Using a rabbit model,
we evaluated the anti-adhesive properties of a sponge-like equine collagen sheet
(TachoComb), which is coated on one side with human fibrinogen and bovine
thrombin. TachoComb is applied by affixing the sheet over the area of perforation
or bleeding and acts as a haemostatic agent, capable of sealing perforations to
prevent leakage. In our rabbit model, adhesions were induced by mechanical and
chemical irritants during laparotomy. After a 1-month recovery period, adhesions
were lysed using microsurgical techniques and TachoComb, or physiological saline
applied. Evaluation of adhesion reformation was determined after a minimum of 10
days. TachoComb significantly reduced the area of adhesion reformation compared
with rabbits treated using physiological saline only. Our study demonstrated that
TachoComb is effective not only as a haemostatic agent, but is also capable of
reducing adhesion reformation.
PMID- 10689631
TI - Clinical evaluation of a haemostatic and anti-adhesion preparation used to
prevent post-surgical adhesion.
AB - TachoComb consists of equine collagen in a sponge-like form coated on one side
with human fibrinogen and bovine thrombin. This product functions as a
haemostatic and physical barrier to inhibit post-surgical adhesion. In this
study, we investigated TachoComb to control oozing in 16 patients who required
haemostasis. Evaluation of post-surgical adhesion by second-look laparoscopy was
performed at 3 months and 7 months after initial surgery. Observation via
laparotomy during Caesarean section was also performed at 13 months, 3 years and
4 years after initial surgery. In all but one patient, no macroscopic evidence of
TachoComb persistence was found. Furthermore, no de novo adhesions were detected
at the TachoComb application site. We have thus demonstrated that TachoComb can
be used to control oozing haemorrhage effectively from surgical sites and can
prevent adhesion formation at the application site, and may thus be an effective
method of preventing adhesion-induced infertility.
PMID- 10689632
TI - Use of androgens and oestrogens in adolescents--a review of hormone replacement
treatment.
PMID- 10689633
TI - Endocrine activity during sleep.
AB - Almost all functions of humans are subject to cyclic changes and are governed by
the nervous system. Most rhythms are driven by an internal biological clock
located in the hypothalamic suprachiasmatic nucleus (SCN) and can be synchronized
by external signals such as light-dark cycles. Homeostatic activities such as
body temperature, blood volume, water balance and sleep, are rhythmic. Likewise,
most hormones are secreted in a rhythmic fashion. Both sleep and circadian
effects interact to produce the overall rhythmic pattern of the pituitary and
pituitary-dependent hormones. Some of the 24-h hormonal rhythms depend on the
circadian clock (ACTH, cortisol and melatonin), or are sleep related (prolactin
and TSH). GH secretion is influenced by the first slow wave sleep (SWS) episode
at the beginning of the night. Pulses of prolactin and GH are positively linked
to increases in delta wave activity, i.e. deepest phases of sleep, occurring
primarily during the first third of the night. Pulses of TSH and cortisol are
related to superficial phases of sleep. As a result of the consolidation of the
sleep period in humans, the wake-sleep transition is associated with
physiological changes with the endocrine system being part of the adaptive
mechanism to reduce physical activity during sleep.
PMID- 10689634
TI - Growth hormone deficiency type IB caused by cryptic splicing of the GH-1 gene.
AB - We have found a novel mutation in intron 4 of the GH-1 gene in a Bedouin kindred
with isolated growth hormone deficiency type IB (IGHD IB). RFLP analysis
suggested linkage between the GH-1 gene and IGHD. Nested PCR amplification
followed by single stranded conformation polymorphism (SSCP) analysis indicated
sequence variation between introns 2 and 4. Sequencing showed a G-->C
transversion at the fifth base in the splice donor region of intron 4. Affected
individuals were homozygous for the mutation, which creates a new Mae III
restriction site. Reverse transcription and PCR of GH-1 transcripts in EBV
transformed lymphocytes indicated predominance of a species lacking 73 bp of exon
4. Amplification with a bridging primer showed that the same mRNA species is
present in lymphocytes from normal individuals. The first 102 amino acids of the
predicted protein are identical to wild-type GH, but the next 94 amino acids are
completely divergent.
PMID- 10689635
TI - An atypical kindred with X-linked adrenal hypoplasia congenita, normal puberty,
and normal Dax-1 promoter and coding sequence.
AB - We report a Chinese kindred with an atypical sex-linked form of isolated adrenal
hypoplasia without hypogonadotropic hypogonadism. Evidence of sex linkage was
supported by DNA analysis using three polymorphic markers from the X-chromosome:
a restriction fragment length polymorphism 200 kb centromeric of the DAX-1 gene,
a tetranucleotide repeat marker in the DAX-1 promoter (DAX-P), and a
microsatellite in the Duchenne muscular dystrophy locus (3'-19). This pedigree
therefore presents the novel phenotype of sex-linked hypoadrenalism without
hypogonadotropic hypogonadism, with evidence of possible linkage to the DAX-1
gene. However, all three affected individuals were examined for mutations in the
DAX-1 gene, and found to have no sequence anomalies in the coding region, splice
sites or 5' non-coding region. This presentation may be due to a defect in the
DAX-1 gene outside its known coding region, possibly modulated by functional
polymorphisms at other loci, and/or environmental effects, or to a defect in a
novel gene on the X chromosome which selectively influences adrenal development.
PMID- 10689636
TI - Persistent hyperinsulinemic hypoglycemia of infancy: long-term outcome following
subtotal pancreatectomy.
AB - BACKGROUND: Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is the
most common cause of persistent hypoglycemia in infants. The current standard
treatment is subtotal pancreatectomy (Px). However, the long-term outcome
following surgery needs further attention. METHODS: We analyzed 10 children (7 M,
3 F) with PHHI who underwent partial (65-80%) and subtotal (81-95%) Px. Follow-up
ranged from 2 to 9.4 yr (mean = 4.2 yr). We divided them into 2 groups based upon
the age at onset of hypoglycemia: early (< 1 mo) and late (> or = 1 mo). RESULTS:
The seven patients in the early-onset group underwent 85-95% Px between ages of
18 d and 3 mo. Three of them initially treated by 85-90% Px had persistent
hypoglycemia postoperatively. Two out of three required a 2nd operation with 95%
Px for controlling hypoglycemia, though both still had persistent hypoglycemia
and required medication to control blood glucose. The remaining four had 95% Px
and had maintained euglycemia postoperatively. One patient developed diabetes 6
yr after surgery. Six of seven patients had delayed development and subnormal IQ.
Three patients of the late-onset group (3 mo, 6 mo and 4 yr) underwent partial Px
(80%, 65% and 65%, respectively) and maintained euglycemia postoperatively.
Despite 65% Px, one developed diabetes 3 yr after surgery. CONCLUSIONS: These
results suggest that children with early-onset hypoglycemia have more severe
hyperinsulinism than those with late-onset hypoglycemia. The former require 95%
Px for maintaining euglycemia, but long-term complications with diabetes may be
common. In contrast, the latter require lower percentage Px which may reduce the
incidence of diabetes in the future.
PMID- 10689637
TI - Length velocity acceleration at 9 months of age in a representative birth cohort
of Dutch infants.
AB - According to the ICP (infancy-childhood-puberty) growth model, statural growth
can be divided into three partially superimposed components assumed to represent
different physiologic mechanisms. This model predicts a sudden acceleration of
length velocity (LV) at the onset of the childhood component around 9 months. The
existence of such an infancy-childhood growth spurt has not yet been firmly
corroborated by epidemiological studies. In the present study length measurements
were made at the target ages of 1, 3, 6, 9, 12, 15, 18 and 24 months in a birth
cohort of 2034 infants. In order to check whether length growth showed a
continuous smooth pattern, different mathematical models were fitted to the
individual growth curves. The models included Count and Guo functions, 5th order
polynomial and combinations of 5th order polynomial with the logarithmic term of
the Count function and the square root term of the Guo function. We showed that
in boys and girls there is a small but systematic lack of fit of the mathematical
modeling, due to a sudden acceleration of LV around 9 months. In addition there
was an increase in variation of attained length at this age. Comparison of
unbalanced ANOVA models with and without addition of dummy variables for the
target ages confirmed that there was an acceleration around 9 months that, if
corrected for, leads to a significantly improved model fit (likelihood ratio test
p < 0.0001). In absolute terms of LV, the misfit at 9 months was not greater than
0.5 cm/year on average. We conclude that the results of this study support the
existence of a late infancy growth spurt. In our opinion, however, the magnitude
of the phenomenon does not legitimate construction and use of discontinuous
growth references such as the ICP reference.
PMID- 10689638
TI - Penile length of newborns in Singapore.
AB - Micropenis is an important sign in congenital hypopituitarism and various
disorders. Documented norms for penile length exist only for babies of Caucasian
and Middle-Eastern origin. This study was carried out to establish such norms for
Asian newborns. We studied 228 male live births within their first three days of
life. Stretched penile lengths were marked off on unmarked wooden spatulas, which
were placed vertically along the dorsal aspect of the penis, with one rounded end
on the pubic bone. The mean penile length +/- S.D. for the full-term Asian baby
was 3.6 +/- 0.4 cm. Race had a significant effect: Chinese 3.5 cm, Malay 3.6 cm
and Indian 3.8 cm. Penile length correlated with birth weight and gestational
age. Asian babies thus have similar norms to Caucasian babies. An Asian newborn
whose penis measures less than 2.6 cm has micropenis and may need prompt
investigation for underlying endocrine disorders.
PMID- 10689639
TI - Longitudinal assessment of L-T4 therapy for congenital hypothyroidism:
differences between athyreosis vs ectopia and delayed vs normal bone age.
AB - To study the effects of LT4 dose on thyroid hormone serum levels, a prospective,
longitudinal and comparative study was designed, including 56 term eutrophic 1-89
day-old infants with congenital hypothyroidism (CH) detected by neonatal
screening. Patients were divided into four groups according to delayed or normal
bone age at birth, and athyreosis or ectopic thyroid. All received an initial
dose of 50 micrograms/day (12.9-13.7 micrograms/kg/day) LT4 and were followed
bimonthly (first year) and quarterly (second year) with thyroid profile and bone
age determinations at 6, 12 and 24 months. At diagnosis, hormone levels were
higher in cases of ectopia than in athyreosis (p < 0.001), and T4 was lower in
children with delayed than in normal bone age at birth (p < 0.05). During
treatment, all groups were clinically euthyroid despite T4 and FT4 serum levels
higher than the upper normal limit (p < 0.0.001), though T3 and FT3 were within
the normal limit (p > 0.05). TSH normalized within 8 weeks. Bone age accelerated
at 2 years in eight children of the bone age delayed group. No patient had
craniosynostosis.
PMID- 10689640
TI - Cord blood leptin levels: relationship to body weight, body mass index, sex and
insulin and cortisol levels of maternal-newborn pairs at delivery.
AB - To investigate leptin and to which factors it is related during the perinatal
period, we measured serum leptin levels of 46 mothers at delivery, umbilical cord
blood and infants on the third day of life. Maternal leptin was higher than in
cord (p < 0.001), and did not correlate with maternal age, body weight, body mass
index, weight gain during pregnancy, serum glucose, cholesterol, triglycerides,
CPE, cortisol or HbA1c levels, nor any biochemical values or anthropometric data
of the newborns (p > 0.05). In cord blood, leptin was significantly higher than
in 3 day-old infants (p < 0.05), and correlated only with maternal insulin and
glucose (r = 0.5, p < 0.01 and r = 0.4, p < 0.05, respectively). In 3 day-old
infants, leptin did not correlate with any clinical data (p > 0.05). Leptin was
not different in the two sexes (p > 0.05). Serum leptin levels were not related
to adiposity of the mother-infant pairs or neonatal growth, and were not
different in the two sexes during the perinatal period.
PMID- 10689641
TI - Intensive diabetes management in adolescents with type 1 diabetes: the importance
of intensive follow-up.
AB - Minimal information exists on the education and follow-up required to
successfully initiate intensive diabetes management (IDM) in adolescents with
type 1 diabetes. We performed a retrospective analysis of HbA1c 3 and 15 months
after initiation of IDM in two cohorts: (1) 17 patients who received
individualised education in IDM and intensive early follow-up, and (2) 11
patients who participated in group education for initiation of IDM with standard
follow-up. Entry HbA1c was higher in the individualised education patients (9.5
+/- 0.3% [mean +/- SE] versus 8.2 +/- 0.4%, p = 0.02). After 3 months of IDM,
HbA1c improved in both cohorts reaching similar levels (individualised: 7.0 +/-
0.1%, p < 0.0001 vs entry; group: 7.3 +/- 0.2%, p = 0.05). During the following
year, with routine follow-up for both cohorts, HbA1c levels rose approximately 1%
as patients reverted to a multiple daily injection regimen. Irrespective of the
educational approach, we believe maintenance of IDM and optimal HbA1c requires
long-term intensive follow-up.
PMID- 10689642
TI - Circulating L-selectin concentrations in children with recent-onset IDDM.
AB - To clarify conflicting claims of altered serum concentrations of soluble L
selectin (sCD62L) in recent-onset IDDM, sCD62L was measured in 89 children and
adolescents with IDDM (35 recent-onset, 12 during the first year of insulin
treatment, and 42 with long-standing (> 1 yr) treatment) alongside 124 controls.
Children < 14 yr of age both with and without IDDM (n = 160) had grossly elevated
sCD62L concentrations (20.2 +/- 4.9 nmol/l), as compared with adolescents (14-18
yr, n = 23; 15.9 +/- 3.9 nmol/l) and adults (> 18 yr, n = 30; 11.2 +/- 2.3
nmol/l) (p < 0.0001). Multivariate analysis confirmed the strong inverse
association between age and sCD62L (p < 0.001) while revealing that sCD62L
concentrations were slightly elevated in recent-onset IDDM, as compared with
insulin-treated IDDM patients or nondiabetic controls (p = 0.028). Actual sCD62L
concentrations in the 35 recent-onset IDDM patients were 22.2 +/- 4.9 nmol/L vs
19.6 +/- 3.6 nmol/l in 35 non-diabetic controls matched for age (p = 0.022).
While this significant but small rise of systemic sCD62L reflects leukocyte
activation, it is obscured by the inverse association between sCD62L and
chronological age in children and adolescents. Therefore, determining sCD62L
serum concentrations appears to be of limited value for clinical investigators
caring for children and adolescents with IDDM.
PMID- 10689643
TI - Analysis of cytokine mRNA expression in pancreatic islets of nonobese diabetic
mice.
AB - Nonobese diabetic mice develop type 1 diabetes in an age-related and gender
dependent manner. Th1 (IFN-gamma and TNF-beta) and Th2 (IL-4 and IL-10) cytokine
mRNA expression was analyzed in pancreatic islets isolated from female NOD mice
with a high incidence of diabetes and male NOD mice with a low incidence of
diabetes. The levels were measured at 5 time points from the onset of insulitis
until the development of overt diabetes, using a semiquantitative reverse
transcriptase PCR (RT-PCR) assay. IFN-gamma mRNA levels were significantly higher
in the islets obtained from females than those of males, from 10 weeks of age.
TNF-beta mRNA was expressed in both females and males between 5 and 15 weeks of
age. However, TNF-beta mRNA levels were decreased in males at 20 weeks of age. In
contrast, IL-4 mRNA levels were lower in females than in males. These results
suggest that islet beta-cell destruction and diabetes in female NOD mice
correlates with IFN-gamma and TNF-beta production in the islets, and that male
NOD mice may be protected from autoimmune beta-cell destruction by down
regulation of these cytokines. Furthermore, our findings also suggest that
insulitis and beta-cell destruction are independently regulated: TNF-beta is more
important in forming and maintaining the insulitis, while IFN-gamma has a more
important role in beta-cell destruction.
PMID- 10689644
TI - Thyroid agenesis associated with phalangeal anomaly.
PMID- 10689645
TI - Serum inhibin B concentration in a prepubertal boy with gynecomastia and Peutz
Jeghers syndrome.
AB - Gynecomastia in boys with Peutz-Jeghers syndrome and Sertoli cell tumors of
gonadal origin results from increased estrogen production due to increased
aromatase activity within the testicular tumor. We present a prepubertal boy with
Peutz-Jeghers syndrome, gynecomastia and bilateral neoplastic Sertoli cell
proliferation in whom the only abnormal hormonal profile was increased
concentration of inhibin B and Pro-alpha C in serum.
PMID- 10689646
TI - Nonclassic 11 beta-hydroxylase deficiency: report of two patients and review.
AB - Congenital adrenal hyperplasia (CAH) is well recognized as a disorder which can
result in virilization of females, accelerated skeletal maturation and resultant
adult short stature in both genders, and, in certain varieties, life-threatening
adrenal crisis. Among the enzymatic defects resulting in CAH, nonclassic or
partial 11 beta-hydroxylase deficiency is a relatively uncommon etiology.
However, the subtlety with which it can present and the difficulties associated
with its diagnosis can delay its identification and result in a significant
reduction in adult stature. This paper describes the presentation and evaluation
of two children with partial 11 beta-hydroxylase deficiency, discusses its
pathogenesis, and compares the disorder with the more common varieties of
congenital adrenal hyperplasia.
PMID- 10689647
TI - Hand test AGG and AOS variables: relation with teacher rating of aggressiveness.
AB - The purpose of this study was to determine the extent to which the Hand Test
(Wagner, 1983) variables Aggression (AGG) and the Acting Out Score (AOS) were
able to differentiate a group of children who were identified as aggressive and
referred for psychological assessment by their teachers from a nonreferred,
control group. Hand Test scores of 37 children who had consecutive referrals for
psychological assessment because of aggressiveness were compared to the Hand Test
scores of 37 children, matched on age and sex, from a nonreferred group. Through
the use of an analysis of variance, AOS and AGG were found to significantly
differentiate between the two groups. Spearman (rho) correlations between AGG and
AOS scores with aggressive-referred status were rho = .45, p = .0001, and rho =
.32, p = .006, respectively. Also, diagnostic efficiency statistics demonstrated
moderate to high overall correct classification rates for AOS > or = 0 and AGG >
or = 2 in identifying children in the aggressive-referred group. The results of
this study provide support for the validity of the AGG and AOS scores in the
assessment of aggressive behavior in children and demonstrate the utility of the
Hand Test to identify aggressive tendencies in children.
PMID- 10689648
TI - Relation between alexithymia and the five-factor model of personality: a facet
level analysis.
AB - The relation between alexithymia and both the domain and the facet level of the
five-factor model (FFM) of personality was examined in a sample of 101 university
students by using the Twenty-Item Toronto Alexithymia Scale (TAS-20; Bagby,
Taylor, & Parker, 1994) and the Revised NEO Personality Inventory (Costa &
McCrae, 1992c). Consistent with the alexithymia construct, the TAS-20 was
positively correlated with Neuroticism (N) and negatively correlated with
Extraversion (E) and Openness (O), whereas no significant relations were found
with Agreeableness (A) and Conscientiousness (C). Analysis of the lower order
traits (i.e., facets) of the FFM revealed that depression for N; positive
emotions and assertiveness for E; feelings and actions for O; altruism, tender
mindedness, and modesty for A; and competence for C predicted alexithymia. These
results support the uniqueness of the alexithymia construct, which is represented
by a cluster of traits across the dimensions and facets of the FFM.
PMID- 10689649
TI - Development and initial validation of a brief mental health outcome measure.
AB - Using a combination of classical test theory and Rasch item analysis, we
developed a short scale designed to measure the effectiveness of mental health
treatment across a wide range of mental health services and populations. Item
development for the scale was guided by literature review and interviews with
senior clinicians and with patients. Using 3 different samples consisting of
inpatients, outpatients, and nonpatients, we reduced our initial item pool from
81 to 10 items. The 10-item scale had an alpha of .96 and showed strong
correlations with commonly used measures of psychological well-being and
distress. Our results suggest that the scale appears to measure a broad domain of
psychological health. The scale appeared to lack ceiling and floor effects, and
it discriminated between inpatients, outpatients, and nonpatients, suggesting the
scale has excellent potential to be broadly responsive to a variety of treatment
effects. In addition, the new scale proved to be sensitive to treatment changes
in a sample of 20 psychiatric inpatients. Overall, the initial data suggest that
we have developed a brief, sensitive outcome measure designed to have wide
application across psychiatric and psychological treatments and populations.
PMID- 10689650
TI - Normative and psychometric data on the body image assessment--revised.
AB - After falling into disfavor in the early 1990s, the construct of body image, as
measured by body-size estimation (BSE) techniques, has been the focus of
increasing interest in the eating disorder literature because of recent
theoretical, empirical, and methodological advances. However, no published BSE
measure to date has been shown to be psychometrically sound, well normed,
inexpensive, and straightforward. This article provides normative and
psychometric data for an adapted silhouette BSE measure. Comprehensive normative
data are presented on college women's cognitively and affectively based body-size
estimates, as well as their desired body size and related discrepancy indexes
(cognitive vs. desired, affective vs. desired, affective vs. cognitive).
Preliminary data indicate that indexes from the new measure are moderately
reliable over time, consistent with their theoretical link to fluctuations in
body-related attitudes. Data also support the convergent validity of the
measures. Affectively based BSE, alone or as part of a discrepancy measure with
desired body size, was most strongly related to measures of eating pathology,
body focus, body dissatisfaction, and depressed affect.
PMID- 10689651
TI - Efficacy of the three Randomness Validity Scales for the Jesness Inventory.
AB - Efficacies of the three randomness validity scales for the Jesness Inventory were
investigated: the Jesness Variable Response Inconsistency scale (J-VRIN), the
Variable Response scale (VR), and the Randomness scale (RD). Effectiveness was
assessed by comparing the protocols of 93 male and 45 female delinquents ages 14
to 18 years screened for probable randomness, with a matched-pair MMPI-Adolescent
with 500 computer-generated all- and half-random protocols. With the all-random
set, for specificities of .90 or higher, scales showed sensitivities as high as
.95 (VR), .90 (J-VRIN), and .14 (RD). With the half-random protocol, set
sensitivities were .74 (VR), .70 (J-VRIN), and .07 (RD). Predictive power and
overall effectiveness are reported for base rates of .20, .10, .067, and .05.
PMID- 10689652
TI - Identification of random responding on the MMPI-A.
AB - Although substantial research literature on the effects of random responding on
the MMPI-2 exists, there is very limited data available on this issue with the
MMPI-A. The purpose of this study was to evaluate the utility of selected MMPI-A
validity scales in detecting differences in response patterns between protocols
produced by 354 adolescents assessed in clinical settings and a group of 354
randomly produced MMPI-A protocols. Results indicate that MMPI-A validity and
basic clinical scales differ significantly between random and clinical groups and
that MMPI-A validity Scales F, F1, F2, and VRIN appear to be most useful in
correctly identifying protocols from actual clinical participants versus randomly
generated response patterns. Findings are discussed in terms of the dramatic
effects of the sample base rate for random responding on overall classification
accuracy results. Furthermore, it was noted that the optimal cutting scores for
MMPI-A Scales F, F1, F2, and VRIN were largely consistent with interpretive
recommendations found in the test manual (Butcher et al., 1992) when the relative
frequency of random response protocols to clinical protocols was evaluated at a
ratio of 1:10. Finally, future recommendations for evaluation of the F1-F2
difference score and the TRIN scale are offered in terms of the most relevant
research designs to evaluate these measures.
PMID- 10689653
TI - Use of the TAT in the assessment of DSM-IV cluster B personality disorders.
AB - The Social Cognition and Object Relations Scale (SCORS), developed by Western,
Lohr, Silk, Kerber, and Goodrich (1985), is a diagnostic instrument used to
assess an array of psychological functioning by using clinical narratives such as
the Thematic Apperception Test (TAT; Murray, 1943) stories. This study
investigated the utility of the SCORS to differentiate between Diagnostic and
Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric
Association, 1994) antisocial personality disorder (ANPD), borderline personality
disorder (BPD), narcissistic personality disorder (NPD), and Cluster C
personality disorder (CPD). A sample of 58 patients was separated into four
groups: ANPD (n = 9), BPD (n = 21; 18 with a primary BPD diagnosis and 3 with
prominent borderline traits who met 4 of the 5 DSM-IV criteria necessary for a
BPD diagnosis), NPD (n = 16; 8 with a primary NPD diagnosis and 8 with prominent
narcissistic traits who met 4 of the 5 DSM-IV criteria necessary for a NPD
diagnosis), and CPD (n = 12). These groups were then compared on the 8 SCORS
variables by using 5 TAT cards (1, 2, 3BM, 4, and 13MF). Spearman-Brown
correction for 2-way mixed effects model of reliability for the 8 SCORS variables
ranged from .70 to .95. The results of categorical and dimensional analyses
indicate that (a) SCORS variables can be used to differentiate ANPD, BPD, and
NPD; (b) the BPD group scored significantly lower (greater maladjustment) than
did the CPD group on certain variables; (c) the BPD group scored significantly
lower (greater maladjustment) than did the NPD group on all 8 SCORS variables;
(d) the ANPD group scored significantly lower than did the NPD group on certain
variables; (e) certain variables were found to be empirically related to the
total number of DSM-IV ANPD, BPD, and NPD criteria; and (f) certain variables
were found to be empirically related to Minnesota Multiphasic Personality
Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989)
Personality disorder scales. The results of this study are discussed in terms of
clinical utility, conceptual, and theoretical implications.
PMID- 10689654
TI - Complexities in complex posttraumatic stress disorder in inpatient women:
evidence from cluster analysis of MCMI-III Personality Disorder Scales.
AB - Herman's (1992a) clinical formulation of complex posttraumatic stress disorder
(PTSD) captures the extensive diagnostic comorbidity seen in patients with a
history of repeated interpersonal trauma and severe psychiatric disorders. Yet
the sheer breadth of symptoms and personality disturbance encompassed by complex
PTSD limits its descriptive usefulness. This study employed cluster analysis of
the MCMI-III (Millon, 1994) personality disorder scales to determine whether
there is meaningful heterogeneity within a group of 227 severely traumatized
women who were treated in a specialized inpatient program. The analysis
distinguishes 5 clinically meaningful clusters, which we label alienated,
withdrawn, aggressive, suffering, and adaptive. The study examined differences
among these 5 personality disorder clusters on the MCMI-III clinical syndrome
scales, as well as on the Brief Symptom Inventory (Derogatis, 1993), Dissociative
Experiences Scale (E. M. Bernstein & Putnam, 1986), Adult Attachment Scale
(Collins & Read, 1990), and Childhood Trauma Questionnaire (D.P. Bernstein,
1995). We present a classification-tree method for determining the cluster
membership of new cases and discuss the implications of the findings for
diagnostic assessment, treatment, and research.
PMID- 10689655
TI - Two-year stability of Psychosis Proneness Scales and their relations to
personality disorder traits.
AB - Two-year stability of Physical Anhedonia (PhA), Perceptual Aberration (PER), and
Magical Ideation (MI) scale scores and their relation to personality disorder
traits were examined. Additionally, the effects of a time-lagged (prospective)
versus concurrent measurement of psychosis proneness and personality disorder
traits were studied to examine the specificity of MI, PER, and PhA. With a non
college-student sample (n = 404), stability for PhA was sufficiently high, but
for PER and MI, stability was moderate to low. The correlations between
personality disorder traits and psychosis proneness scales demonstrate that
simultaneous assessment leads to a more nonspecific pattern of associations for
MI and PER, although the correlation to schizotypal personality disorder traits
were the highest. However, prospectively only MI, but neither PER nor PhA,
emerged as a significant predictor for schizotypal and paranoid personality
disorder traits in multiple-regression analysis. This suggests that MI may allow
for a more specific assessment of psychosis proneness than PER.
PMID- 10689656
TI - Problem drinkers: evaluation of a stepped-care approach.
AB - The present study evaluated a stepped-care model for the treatment of problem
drinkers; those not severely dependent on alcohol. The initial treatment
consisted of a motivationally based, four-session outpatient treatment. Based on
previous research, treatment nonresponders were defined as having consumed more
than 12 drinks per week between the assessment and third session. Six-month
follow-up interviews were conducted on three groups of problem drinkers: (1)
those who responded to the initial intervention (n = 67); (2) those who did not
respond to the initial treatment (n = 36); and (3) those who did not respond to
the initial treatment and received a supplemental intervention (n = 33). The last
two groups were used to evaluate whether providing treatment nonresponders with
an additional "step" would improve treatment outcomes. The primary dependent
measures were posttreatment percent days abstinent and posttreatment drinks per
drinking day. Results suggested that (1) within treatment drinking can help
identify treatment nonresponse in stepped-care models; (2) the supplemental
intervention did not influence posttreatment drinking; (3) treatment responders
and nonresponders sought additional help at the same rate. The present study is
the first study on stepped-care for alcohol treatment and provides a methodology
for evaluating stepped interventions. Recommendations for future research in this
area include more attention to assessing the needs of treatment nonresponders and
help seeking behavior of both responders and nonresponders after an initial
intervention.
PMID- 10689657
TI - Simultaneous polydrug use among teens: prevalence and predictors.
AB - The use of two or more substances in combination, simultaneous polydrug use
(SPU), is a particularly dangerous form of drug use that appears to be
established by late adolescence. We examined the prevalence of SPU in a diverse
sample of 12th graders, and identified risk and protective factors for SPU that
are present at 10th grade. We also tested for differences in SPU across race and
gender, and explored the basis for observed differences. Our goals were to
determine the extent of SPU problems in different groups and how to address these
problems. Twenty-nine percent of participants had engaged in SPU in the past
year. The best predictors of alcohol/marijuana SPU were a pro-drug environment,
pro-drug beliefs, social deviance, and family disruption; only a pro-drug
environment was predictive of hard drug SPU. Women were far less likely to
combine marijuana and alcohol than were men. Asian Americans were less likely to
combine alcohol and marijuana than were other racial groups, apparently due to
their advantaged standing on all predictors of this behavior. African Americans
were less likely to use hard drugs in combination than were other groups.
Overall, polydrug use is a substantial problem for older teens. Broader drug-use
prevention programs may be sufficient to address SPU involving gateway drugs, but
reducing drug availability appears central to addressing hard drug SPU.
PMID- 10689658
TI - The relationship between cannabis use and DSM-IV cannabis abuse and dependence:
results from the National Longitudinal Alcohol Epidemiologic Survey.
AB - The purpose of-this study was to determine the risk of Diagnostic and Statistical
Manual of Mental Disorders--Fourth Edition (DSM-IV) cannabis abuse and dependence
at different levels of cannabis use in a nationally representative sample of the
U.S. general population. Two separate logistic regression analyses were conducted
to determine the association between cannabis use, and abuse and dependence. The
risk of cannabis abuse and dependence was found to increase with the frequency of
smoking occasions and slightly decreased with age. More severe comorbidity was
associated with dependence compared to abuse, suggesting that cannabis might be
used to self-medicate major depression. The strength of the association between
cannabis use and abuse was also increased as a function of the number of joints
smoked among females, but not males. These results were discussed in terms of
differential societal reactions, the self-medication hypothesis, and gender
biases in diagnosing cannabis abuse.
PMID- 10689659
TI - Electrical stimulation therapy in the treatment of cigarette smoking.
AB - In this study electrical stimulation therapy (EST) is explored as a possible new
treatment for smoking cessation within a randomized controlled trial. The
investigation follows reports of several authors that electrical stimulation
applied to specific acupuncture points is effective in treating a variety of drug
dependencies, including cigarette smoking. Three key features of treatment
(electrical stimulation, frequency modulation, and electrode placement), were
investigated in a 2 x 2 x 2 factorial design, resulting in eight treatment
combinations. Out of 265 smokers recruited into the trial 216 completed the one
week treatment. Outcome was assessed in terms of complete abstinence from smoking
and symptomatic relief of withdrawal symptoms. Smokers receiving active
electrical stimulation obtained higher abstinence rates than those in the
inactive groups although the difference did not achieve statistical significance
(all active vs. all placebo groups: lambda 1,1(2) = 0.50, p > 0.10, 95%
confidence interval = -8.04 to +17.44%; most effective vs. least effective group:
lambda 1,1(2) = 3.11, p = 0.08, CI0.95 = -2.2 to +48.8%). The efficacy of
electrical stimulation therapy for smoking is not supported.
PMID- 10689660
TI - The test-retest reliability of the frequency of multiple drug use in young drug
users entering treatment.
AB - Assessment of multiple drug use relies primarily on self-report. Several studies
support the reliability of client self-reports of drug use but these studies have
not involved assessment of the actual frequency of drug use. This test-retest
reliability study assessed the frequency of drug use in a clinical sample of 103
multiple drug users, aged 16-25 years. At initial assessment, all participants
completed the Drug Use History Form (DUHF) that inquired about the number of drug
using days and the daily frequency of use for 13 drug classes during four time
intervals. The DUHF was readministered 2-4 weeks later. Reliability was assessed
using Intra-class correlations (ICC's). The results indicated that clients do, in
general, reliably report both the number of days of use and daily frequencies.
The two frequency measures were not highly correlated. Reliability estimates
declined over time but most markedly after 90 days, suggesting that assessments
of drug use can be reliably extended beyond 30 days. Frequency estimates based
solely on the number of days of use of a substance may be unreliable estimates of
actual drug consumption, indicating limitations to this commonly used outcome
measure.
PMID- 10689661
TI - Community reinforcement and family training (CRAFT): engaging unmotivated drug
users in treatment.
AB - Although motivation for drug abuse treatment is a substantial problem, unilateral
intervention through concerned significant others (CSOs) represents a promising
method for engaging unmotivated individuals. The Community Reinforcement and
Family Training (CRAFT) program, based on principles of reinforcement was
developed for this specific purpose. In Phase I, CSOs received the CRAFT
intervention, whereby they were taught skills for modifying a loved one's drug
using behavior and for enhancing treatment engagement. CSOs were evaluated at 3
and 6 months. In Phase II, engaged drug users received treatment using the
Community Reinforcement Approach (CRA). A total of 62 CSOs participated in this
evaluation of the effectiveness of CRAFT. CSOs completed, on average, 87% of
offered treatment sessions. During the 6-month study period, 74% succeeded in
engaging their resistant loved one in treatment. Reported abstinence both from
illicit drugs and alcohol increased significantly for drug users engaged in
treatment, but not for unengaged cases. All CSOs showed significant reduction in
depression, anxiety, anger, and physical symptoms, with average scores dropping
into the normal range on all measures. CRAFT provides a promising alternative to
confrontational and detachment approaches in counseling CSOs to help their loved
ones.
PMID- 10689662
TI - Alcohol, intelligence and violent crime in young males.
AB - Research has demonstrated a relationship between alcohol and violent behavior,
but proof of a causal connection remains elusive. A recent review concluded that
the key task that remained was to identify sub-groups of the population for which
alcohol promotes violence. Because alcohol might induce violence by causing
cognitive disruption (e.g., misunderstood communication), less intelligent
persons could be vulnerable because they start out closer to the lower limit of
comprehension. Our objective is to investigate the effect of lower intelligence
on the alcohol/violence relationship. This analysis uses data from the Buffalo
Longitudinal Study of Young Men to investigate this hypothesis. Males, 16 to 19
years of age (N = 596), were selected from Buffalo, NY, by random digit dialing.
High-risk males were oversampled. Two interviews were conducted 18 months apart,
including drinking, criminal offenses, and psychological traits. Verbal
intelligence was measured by the Ammons Quick Test and visual-motor intelligence
by the Trail Making Test. An analysis of covariance was conducted with wave 2
average alcohol consumption and both measures of intelligence as independent
variables, violent offending as the dependent variable, and race, wave 1 alcohol
and wave 1 violence as covariates. Results show a positive main effect of wave 2
alcohol consumption, but also interactions with both verbal and visual-motor
intelligence. These interactions indicate that the prevalence of violence
increases significantly at low intelligence and high alcohol consumption levels.
A parallel analysis with nonviolent offending as the dependent variable failed to
find significant interactions. The combination of heavy drinking and lower
intelligence is associated with a synergistic surge of violent behavior.
PMID- 10689663
TI - Investigation of the tris(trimethoxyphenyl)phosphonium acetyl charged derivatives
of peptides by electrospray ionization mass spectrometry and tandem mass
spectrometry.
AB - Charged derivatives of peptides are useful in obtaining simpler collision
activated dissociation (CAD) mass spectra. An N-terminal charge-derivatizing
reagent capable of reacting with picomole levels of peptide has been recently
reported (Huang et al. Anal. Chem. 1997, 69, 137-144) in the contexts of analyses
by fast atom bombardment (FAB) and matrix-assisted laser desorption/ionization
(MALDI) mass spectrometry. Electrospray ionization (ESI) mass spectrometric
investigation of these tris(trimethoxyphenylphosphonium) acetyl derivatives are
described in this article, including studies by in-source fragmentation (ISF) and
tandem mass spectrometry (MS/MS). Results from ISF are compared with those from
MS/MS. Similarities and differences between ESI-ISF, MALDI-post-source decay
(PSD), and FAB-CAD data are presented. Differences in fragmentation of these
charged derivatives in the triple quadrupole and ion trap mass spectrometers also
are discussed. Application of this derivatizing procedure to tryptic digests and
subsequent analysis by liquid chromatography-mass spectrometry is also shown.
PMID- 10689664
TI - Unequivocal determination of metal atom oxidation state in naked heme proteins:
Fe(III)myoglobin, Fe(III)cytochrome c, Fe(III)cytochrome b5, and
Fe(III)cytochrome b5 L47R.
AB - Unambiguous determination of metal atom oxidation state in an intact
metalloprotein is achieved by matching experimental (electrospray ionization 9.4
tesla Fourier transform ion cyclotron resonance) and theoretical isotopic
abundance mass distributions for one or more holoprotein charge states. The ion
atom oxidation state is determined unequivocally as Fe(III) for each of four gas
phase unhydrated heme proteins electrosprayed from H2O: myoglobin, cytochrome c,
cytochrome b5, and cytochrome b5 L47R (i.e., the solution-phase oxidation state
is conserved following electrospray to produce gas-phase ions). However, the same
Fe(III) oxidation state in all four heme proteins is observed after prior
reduction by sodium dithionite to produce Fe(II) heme proteins in solution: thus
proving that oxygen was present during the electrospray process. Those results
bear directly on the issue of similarity (or lack thereof) of solution-phase and
gas-phase protein conformations. Finally, infrared multiphoton irradiation of the
gas-phase Fe(III)holoproteins releases Fe(III)heme from each of the noncovalently
bound Fe(III)heme proteins (myoglobin, cytochrome b5 and cytochrome b5 L47R), but
yields Fe(II)heme from the covalently bound heme in cytochrome c.
PMID- 10689665
TI - On-line capillary liquid chromatography tandem mass spectrometry on an ion
trap/reflectron time-of-flight mass spectrometer using the sequence tag database
search approach for peptide sequencing and protein identification.
AB - Capillary high-performance liquid chromatography has been coupled on-line with an
ion trap storage/reflectron time-of-flight mass spectrometer to perform tandem
mass spectrometry for tryptic peptides. Selection and fragmentation of the
precursor ions were performed in a three-dimensional ion trap, and the resulting
fragment ions were pulsed out of the trap into a reflectron time-of-flight mass
spectrometer for mass analysis. The stored waveform inverse Fourier transform
waveform was applied to perform ion selection and an improved tickle voltage
optimization scheme was used to generate collision-induced dissociation. Tandem
mass spectra of various doubly charged tryptic peptides were investigated where a
conspicuous y ion series over a certain mass range defined a partial amino acid
sequence. The partial sequence was used to determine the identity of the peptide
or even the protein by database search using the sequence tag approach. Several
peptides from tryptic digests of horse heart myoglobin and bovine cytochrome c
were selected for tandem mass spectrometry (MS/MS) where it was demonstrated that
the proteins could be identified based on sequence tags derived from MS/MS
spectra. This approach was also utilized to identify protein spots from a two
dimensional gel separation of a human esophageal adenocarcinoma cell line.
PMID- 10689666
TI - Internal glucose residue loss in protonated O-diglycosyl flavonoids upon low
energy collision-induced dissociation.
AB - The low-energy collision-induced dissociation of protonated flavonoid O
diglycosides, i.e., flavonoid O-rutinosides and O-neohesperidosides, containing
different aglycone types has been studied. The results indicate that the unusual
[M + H - 162]+ ion formed by internal glucose residue loss, which in a previous
study was shown to be a rearrangement ion, is strongly dependent upon the
aglycone type. For 7-O-diglycosides, the internal glucose loss is very pronounced
for aglycones of the flavanone type, but is completely absent for aglycones of
the flavone and flavonol types. Internal glucose residue loss was found to
correspond to a minor fragmentation pathway for flavonol 3-O-diglycosides. A
plausible mechanism is proposed based on proton mobilization from the aglycone to
the disaccharidic part of the flavonoid O-diglycosides which is supported by
theoretical calculations and model building.
PMID- 10689667
TI - Interpretation of matrix-assisted laser desorption/ionization postsource decay
spectra of charge-derivatized peptides: some examples of tris[(2,4,6
trimethoxyphenyl) phosphonium]-tagged proteolytic digestion products of
phosphoenolpyruvate carboxykinase.
AB - The fragmentation of peptides, to which a positive charge is attached at the N
terminus, was studied by matrix-assisted laser desorption/ionization postsource
decay mass spectrometry. In these experiments, the tris[(2,4,6
trimethoxyphenyl)phosphonium] acetyl group is covalently attached. The main
advantage of this modification is that the resulting spectra are simplified and
the fragment ions observed consist predominantly of a(n)-type ions. We report the
results for charge-derivatized peptides formed following enzymatic digestion of
phosphoenolpyruvate carboxykinase. Specific fragmentation of bonds within
aspargine and threonine residues are observed and are discussed. The
understanding of the mechanistic aspects of the fragmentation process is
essential to formulate a simple and straightforward mass spectrometric strategy
for peptide sequencing using these charged derivatives.
PMID- 10689668
TI - Matrix-assisted laser desorption/ionization mass spectrometry, enzymatic
digestion, and molecular modeling in the study of nonenzymatic glycation of IgG.
AB - The glycation-induced functional change of immunoglobulins is of particular
interest. The glycation levels of IgG in 10 healthy subjects and 20 diabetic
patients with different degrees of metabolic control were studied by matrix
assisted laser desorption/ionization (MALDI) mass spectrometry. It reveals the
number of glucose molecules that have condensed on the protein, which range from
1 to 5 for healthy subjects, from 5 to 9 for well controlled diabetic patients,
and from 10 to 25 for poorly controlled ones. The identification of the most
favored glycation sites has been obtained by MALDI analysis of standard and in
vitro glycated IgG and plasma protein fraction of a healthy subject after
digestion with papain, releasing Fab and Fc fragments of the molecule. Both
experiments, as well as molecular modeling of the whole protein, confirm that the
most of glucose molecules have condensed on the Fab fragment of IgG, suggesting
that the immune deficiency observed in diabetic patients may be explained at the
molecular level by a more effective glycation of the Fab fragment, thus
inhibiting the process of molecular recognition between antibody and antigen.
PMID- 10689669
TI - Tandem time-of-flight experiment for low energy collision studies.
AB - We present an experiment adapted to collisional studies of cluster ions based on
a laser vaporization setup coupled to a supersonic expansion. The ions are
selected in a first time-of-flight, slowed down to the desired energy, and
collided in an octopolar guide. The parent and fragment ions are then
reaccelerated in order to be mass analyzed in a reflectron time-of-flight. An
original method for the extraction of the ion that uses a double voltage pulse,
is proposed. The experiment has been applied to collisions of hydrated cobalt
ions. An absolute cross section of 17 A2 for the loss of one water molecule by
Co(H2O)2+ in collision with neon at a center-of-mass energy of 10 eV, has been
determined, with an accuracy of 10%. The threshold for this reaction has been
measured at 1.5 eV and is in good agreement with the existing literature
(Dalleska et al. J. Am. Chem. Soc. 1994, 116, 3519). Ions that cannot be formed
by conventional ligand exchange methods, can also be studied. As an example, the
threshold for dehydration of the Co2(H2O)+ ion has been measured at 1.5 +/- 0.2
eV.
PMID- 10689670
TI - Gas phase H/D exchange kinetics: DI versus D2O.
AB - The gas phase H/D exchange reactions of bradykinin (M + 3H)3+ ions with D2O and
DI were monitored in a quadrupole ion trap mass spectrometer. The H/D exchange
kinetics of both chemical probes (D2O and DI) indicate the presence of two
noninterconverting reactive gas phase ion populations of bradykinin (M + 3H)3+ at
room temperature. The H/D exchange involving DI, however, generally proceeds
faster than that involving D2O. The rate observations described here can be
rationalized on the basis of the "relay mechanism" (see Campbell et al. J. Am.
Chem. Soc. 1995, 117, 12840-12854) recently proposed to account for H/D exchange
between D2O and gaseous protonated polypeptides. The higher exchange rate with DI
is believed to arise primarily as a result of its lower gas-phase acidity
relative to that of D2O and, secondarily, as a result of the longer bond length
of DI relative to that of OD in D2O.
PMID- 10689671
TI - Detection of transthyretin variants using immunoprecipitation and matrix-assisted
laser desorption/ionization bioreactive probes: a clinical application of mass
spectrometry.
AB - In our continuing efforts to develop mass spectrometry-based methods for
transthyretin (TTR) variant detection and characterization, we have sought to use
matrix-assisted laser desorption/ionization (MALDI) bioreactive probes
incorporating immobilized trypsin for screening purposes. These devices show good
diagnostic potential as a clinical screening tool to detect amino acid
substitutions in TTR. MALDI probes allow the on-probe generation of tryptic
digests. The subsequent mass analysis of the on-probe digest yields the peptide
map. The inherent advantages of this method include considerably reduced
digestion times (minutes vs. hours), absence of autolysis products, minimized
sample handling, and hence minimal sample loss. A further advantage is that the
opportunity for loss of hydrophobic peptides is reduced because no sample
transfer occurs. The method can be applied as a preliminary screen for TTR
variants where TTR is isolated from patient serum through immunoprecipitation.
This method should also be applicable to other proteins and suitable for
automation.
PMID- 10689673
TI - [Quality assurance and cost containment--counterproductive or synergistic
effects?].
AB - Quality of care and cost considerations are becoming increasingly intertwined.
While costs were an insignificant factor in quality management 30 years ago,
today the consumption of resources is a measure of the quality of outcome. Newly
developed clinical guidelines are intended to reduce the cost of care in the
future. However, they entail a significant potential for abuse that can
compromise quality. Guidelines are necessary to demonstrate the cost
effectiveness of quality control and quality assurance measures. Excessive
emphasis on quality assurance may increase the overall consumption of resources.
In a managed care setting with budgetary constraints, this can reduce the quality
of care.
PMID- 10689672
TI - Mass spectrometric analysis of platelet-activating factor after isolation by
solid-phase extraction and direct derivatization with pentafluorobenzoic
anhydride.
AB - Platelet-activating factor is the term used to denote a class of extremely potent
lipid mediators that consist predominantly of 1-O-alkyl- and 1-O-acyl-2-acetyl-sn
glycero-3-phosphocholines. A method has been devised for rapid isolation of these
acetylated phospholipids by solid-phase extraction prior to direct derivatization
with pentafluorobenzoic anhydride and analysis by gas chromatography
(GC)/electron-capture mass spectrometry. Recovery through the entire method
(lipid isolation, derivatization, and purification) typically ranged from 70% to
85%. Using the direct derivatization procedure described here, the practical
limit of detection for each of the standard alkyl- and acyl-platelet-activating
factor homologs was 1 fmol injected into the GC. Results from the application of
the method to the analysis of alkyl and acyl homologs of platelet-activating
factor isolated from stimulated human umbilical vein endothelial cells are
presented, exhibiting excellent accuracy and precision for a wide range of tissue
levels of this class of potent autacoids.
PMID- 10689674
TI - ["Fuldaer ventilation surgery"--a surgical concept in severe ventilation
disorders of the middle ear].
AB - BACKGROUND: This report presents the long-term results of a special surgical
technique in cases of persistent severe dysfunction of the Eustachian tube.
PATIENTS AND METHODS: We performed this operation on 16 patients (18 ears)
between 1982 and 1997. Almost all patients had undergone previous surgery. This
included myringotomies and tube insertions, adenoidectomies, tonsillectomies,
myringoplasties and mastoidectomies, sinus surgeries, and an operation on a cleft
palate. The concept developed by one coauthor (Draf) combines different methods
to improve ventilation of the middle ear and protect the eardrum against partial
vacuum. The concept combines mastoidectomy, posterior tympanotomy, and removal of
the incus and the head of the malleus with an interposition of the incus. The
tympanic membrane is then stabilized with a cartilage-perichondrium graft, and a
tube is placed leading from the tympanic cavity to the nose (Wright-tube). A T
tube may also be used. The procedure was varied slightly on occasion depending on
intraoperative findings. RESULTS: Thirteen patients (15 ears) were available for
audiometry at a minimum of 5 months after surgery until 14 years (mean duration
of 6.2 years). We compared preoperative and postoperative air-bone gaps. They
were measured for the three speech frequencies (500, 1000, and 2000 Hz) at 5 dB
intervals. The average preoperative air-bone gap was 25.7 dB versus 18.2 dB
postoperatively. This represents an improvement of 7.5 dB. Seven of fifteen ears
required revision. Six ears required one revision procedure each (three for
cholesteatoma, one for myringitis, one for discharge due to a narrow external
auditory meatus, and one for mastoiditis). Another patient required three
revision procedures (one for mastoiditis and the other two for cholesteatoma).
CONCLUSION: This concept can help prevent cholesteatoma and improve hearing in
more than 50 per cent of severe cases of dysfunction of the Eustachian tube.
PMID- 10689675
TI - [Use of auditory field measurement in patients with otosclerosis].
AB - BACKGROUND: Middle ear surgery sometimes leads to unpleasant auditory impressions
such as distortion or hyperacusis that cannot be detected by conventional
audiometric testing. METHOD: Sixty-one patients with conductive hearing loss
caused by otosclerosis underwent audiological evaluation, which included a
questionnaire followed by testing of the audiometric threshold, speech
audiometry, and assessment and quantification of loudness perception with a
commercial system (WESTRA). This investigation includes the postoperative
measurement of hearing improvement and the patients' subjective impressions
regarding hearing increase, distortion of speech, and hyperacusis. RESULTS:
Hearing improved in 88% of the patients. A quantification of this hearing
increase was possible with pure tone audiometry and the Freiburg speech
discrimination test. Reduced hearing threshold and lack of improvement in speech
discrimination was confirmed by conventional hearing measurements. However, the
presence of hyperacusis and distortion of speech could be determined by
conventional audiometry in only 50% of cases. It was interesting to note that the
subjects who reported speech distortion and hyperacusis in the questionnaire were
identified by their increased loudness perception using the categorical loudness
scaling. CONCLUSION: Category loudness scaling appears to be a valuable
additional clinical test to characterize postoperative phenomena as distortion of
speech and hyperacusis in patients undergoing stapes surgery.
PMID- 10689676
TI - [Histopathological studies of intratemporal growth behavior of middle ear
carcinoma].
AB - BACKGROUND: Otological hemorrhage otorrhea, and pain are amongst the first
clinical signs of the middle ear carcinoma, which is usually diagnosed in
advanced stages. Sudden deafness, facial nerve paralysis, and other symptoms of
inner ear damage may be observed in the final stage. However, middle ear
carcinoma is diagnosed extremely seldom in its early stages. The clinical
management of this pathology is based on the knowledge of the tumor's pathways
and its anatomic behavior. METHODS: Our study investigated 20 cases of middle ear
carcinomas from the Wittmaack temporal bone bank (14 squamous cell carcinomas, 5
adenocarcinomas, and 1 adenoidcystic carcinoma) to analyze the behavior of the
tumor growth and its influence on clinical symptoms. The aim was to determine
criteria for early clinical diagnosis. RESULTS: The tumor arises in different
regions of the temporal bone, and varying symptoms will subsequently reflect its
pathway. When the tumor is confined to the middle ear area, its main location is
the hypotympanum from which tumor spreads into the eustachian tube and, via
infiltration of the adjacent bone structures (anterior wall of the middle ear),
into the tensor tympani muscle and the sympathetic plexus of the internal carotid
artery. Destruction of the ossicles was observed in the mid-tympanic cavity, and
often only a thin layer of fibrous tissue from the Fallopian canal separated the
tumor from the facial nerve (this nerve was rarely affected directly). The medial
wall (labyrinthine wall) of the tympanic cavity remained intact in the majority
of examined cases. The tympanic sinus, the round window niche, and the oval
window niche did not show tumor infiltration. In the epitympanum, the tumor grew
and infiltrated the adjacent mastoid. Larger tumors affected the internal
auditory canal and infiltrated the acoustic nerve and the labyrinth. CONCLUSION:
Improving the poor prognosis of middle ear carcinoma requires early diagnosis
based on axial computed tomography (CT). Important factors in patient selection
include age (50-70 years), sex (mostly women), and especially clinical symptoms
(otorrhea, pain, hearing loss).
PMID- 10689677
TI - [An anesthesia technique for experimental studies and microsurgical ear
interventions in newborn rodents].
AB - BACKGROUND: Experimental investigations on laboratory animals usually require
sufficient anesthesia with adequate analgesia and sedation. The technique used
should be reliable and easily controllable by the investigator. Here, we present
a technique for anesthesia to facilitate invasive and noninvasive investigations
in newborn rats and mice. METHODS: Using a custom made breathing mask, anesthesia
was induced in these animals with inhalation of gaseous nitrous oxide-oxygen
(equal volume at 1 l/min) and halothane (3% by volume). To maintain anesthesia,
halothane insufflation was reduced to 1-1.5% by volume. After completion of the
experimental procedure, the application of the inhalative gases was determined
and substituted by oxygen at 2 l/min. Anesthesia was performed in spontaneously
breathing animals. Heart frequency and oxygenation were monitored using a
commercially available pulse oximeter. RESULTS: Using the above described
technique in neonatal rodents, microsurgery of the ear was performed without
signs of pain or major bleeding. Auditory brain stem responses were recorded
clearly and reproducible. CONCLUSIONS: This method represents a noninvasive, well
tolerated and easy controllable anesthetic procedure which has proven to provide
a sufficient and reliable sedation in neonatal rodents for surgical and
nonsurgical investigations.
PMID- 10689678
TI - [Antibiotic impregnation of cartilage implants: diffusion kinetics of
fluoroquinolones].
AB - BACKGROUND: Antibiotic impregnation of cartilage implants may reduce the risk of
bacterial infection and subsequent absorption. The aim of this study was to
investigate the penetration kinetics of two quinolone antibiotics into fresh
cartilage and the concentrations in the core of lyophilized cartilage after
rehydration. METHODS: Fresh human costal cartilage was impregnated with ofloxacin
and ciprofloxacin (2 mg/ml) for 2, 15 and 90 min. Concentrations were measured in
6 levels (0.5 mm each) from the surface to 3 mm beneath the surface with high
performance liquid chromatography (HPLC). Lyophilized human costal cartilage was
rehydrated in ofloxacine and ciprofloxacine solutions (2 mg/ml, 0.2 mg/ml and
0.02 mg/ml) for 18 hours and concentrations in the core of the rib segment were
measured. RESULTS: Quinolone antibiotics penetrate into cartilage by free
diffusion. We found no evidence of significant binding to cartilage. After 2 and
15 min of impregnation, concentrations above the minimal inhibitory concentration
(MIC90) for pseudomonas species are found from 0-0.5 mm below the surface of
fresh cartilage. After 90 min concentrations above the MIC90 were found 1.0-1.5
mm below surface of the implant. In lyophilized rib grafts which were rehydrated
in 1/10 diluted intravenous solutions (0.2 mg/ml), concentrations in the core of
the specimen were above MIC90. Differences between the penetration
characteristics of ofloxacine and ciprofloxacine were minor. CONCLUSION:
Intraoperative impregnation of cartilage implants with ofloxacin or ciprofloxacin
probably offers only short-term protection against bacterial infection.
Rehydrated rib grafts, however, contain high quinolone concentrations which may
be effective even in infected implant beds for several hours.
PMID- 10689679
TI - [Value of multimedia educational software in training of the paranasal sinus
surgeon].
AB - BACKGROUND: When starting sinus surgery, every surgeon has to pass through an
individual learning curve. To avoid complications, costly, time-consuming
surveillance is necessary. We wanted to analyse the impact of multimedial
teaching software on the learning curve. METHODS: A total of 1104 operations
performed by four surgeons were evaluated. The first consecutive 200 operations
by each surgeon were analyzed according to their complications. After revaluating
the general phases of surgical development, we compared the first 90 operations
by another group of four surgeons who had undergone training with the teaching
program. RESULTS: Cauterization of the anterior ethmoidal anterior was nearly the
same in both groups (10/8). Injuries of the dura dropped from 5 to 2, and
periorbital lesions were reduced significantly from 20 to 5 (p < 0.001).
CONCLUSIONS: Multimedial learning programs can reduce complications effectively
and form a valuable part training.
PMID- 10689680
TI - [Endoscopic treatment of iatrogenic esophageal perforation].
AB - BACKGROUND: Esophageal perforations are the most frequent complications of
endoscopy of the upper gastrointestinal tract. Life-threatening consequences such
as mediastinitis, septic disease, or multiple organ failure are possible.
Traditional surgical and conservative methods of treatment should be
distinguished. In serious cases, thoracotomy in particular is a high-risk
operation. PATIENTS AND RESULTS: This case demonstrates the successful endoscopic
treatment of an esophageal perforation with mediastinal empyema by fibrin gluing.
CONCLUSIONS: Esophageal perforations up to 20 cm aboral and a maximum diameter of
1.5 cm could be treated by rigid endoscopical fibrin gluing. High-risk patients
could be managed effectively avoiding extensive surgery.
PMID- 10689681
TI - [Animal experiment study of anastomosis healing after partial resection of the
pre-irradiated thoracic esophagus].
AB - BACKGROUND: Multimodal therapeutic concepts in cases of neoplasms of the
intestinal tract entail the risk of undesirable complications with respect to
healing of wounds and anastomoses. The separate steps of a combined treatment
consisting radiation therapy and partial resection of the thoracic esophagus were
performed in animal experiments to study the effect of radiation therapy on the
healing of anastomoses. METHOD: Adult non-purebred dogs were irradiated in a
defined thoracic field with a Betatron (42 MeV) and subsequently underwent
esophagectomy. After resection of a 2 cm segment of the esophagus end-to-end
anastomosis was performed. Different methods of irradiation and postoperative
observation times resulted in a total of 8 groups of 3 animals each. RESULTS:
Fractionated irradiation was definitely better tolerated than irradiation with a
high single doses. The temporary delay of the anastomotic healing was documented
histologically. Only one case of anastomotic leakage occurred, and impaired wound
healing was observed in only one animal. CONCLUSION: The mode of irradiation must
be regarded as important for the clinical course. Fractionated preoperative
irradiation in the area of the thoracic esophagus does not lead to any relevant
disturbance of wound and anastomotic healing with meticulous surgical technique
and adequate intensive postoperative care. The basic feasibility of surgical
therapy combined with preoperative radiotherapy in tumors of the upper digestive
tract was confirmed by our experimental work.
PMID- 10689682
TI - [Lipoma-like liposarcoma of the tongue].
AB - BACKGROUND: Liposarcomas of the tongue are rare. To date only 7 cases have been
reported. PATIENT: We report a new case of a well differentiated lipoma-like
liposarcoma of the body of the tongue in a 71-year old woman. Complete uneventful
resection was performed. Histologically the tumor consisted of fat cells with
occasional lipoblasts and spindle cell areas. There is no sign of recurrence of
the tumor 2 years later. RESULTS AND CONCLUSIONS: Liposarcomas of the tongue are
rare neoplasms. All cases reported were histologically well differentiated.
Liposarcomas have to be considered in the differential diagnosis of solid masses
of the tongue.
PMID- 10689684
TI - [Tracheal surgery. Tracheotomy].
PMID- 10689683
TI - [Analgesic intolerance and nasal polyps].
PMID- 10689685
TI - [Clinicopathological diagnosis of the diseases in stalk and neurohypophysis].
PMID- 10689686
TI - [Study of the molecular bases of familial amyloidotic polyneuropathy].
PMID- 10689687
TI - [Analysis of segmental motor conduction in the median and the ulnar nerves:
comparison between normal and diabetic individuals].
AB - We investigated characteristics of segmental motor conduction in the median and
the ulnar nerves. Subjects were 55 individuals with normal conduction of the
upper extremity and 71 patients with diabetes mellitus. Mean polyneuropathy index
(PNI), which was determined as a mean percentage of the normal for 6 indices
concerning to the conduction velocity in the upper limb, was 99.0% in the normal
group and 85.6 % in the diabetic group on the mean. In the normal group distal
latency was longer in the median nerve than in the ulnar nerve, and the
conduction time between Erb's point and the wrist was longer in the ulnar nerve
than the median nerve both in men and women. In the diabetic group these
differences were accentuated; that means the distal latency was relatively more
prolonged in the median nerve and the conduction time between Erb's point and the
wrist was much longer in the ulnar nerve. Prolonged distal latency in the median
nerve of women and conduction delay between Erb's point and the wrist in the
ulnar nerve of men altogether resulted in the gender difference in the median
minus ulnar F-wave latency after wrist stimulation in the diabetic group. Carpal
tunnel segment of the median nerve and the elbow segment of the ulnar nerve are
known to be common entrapment sites. This phenomenon of accentuated conduction
delay in these common entrapment sites might be considered as a sort of 'double
crush syndrome'.
PMID- 10689688
TI - [Effect of number of syllables in word repetition].
AB - We report a case of non-fluent conduction aphasia. The patient was a 59-year-old
right-handed male. He suffered from aphasia after a left internal carotid artery
occlusion. MRI study revealed subcortical lesions in the left inferior frontal
gyrus and cortical lesion in the anterior part of the left insular gyrus and the
left postcentral gyrus. The patient showed good comprehension of words and daily
conversation but had a common difficulty in the following tasks; naming of
pictures, repetition of words, reading of kanji and kana letters. In these tasks,
the phonological output of the patient contained many literal paraphasias and
there was a tendency that errors appeared more in the posterior portion of a
target word. We analyzed the position of errors in the target word on word
repetition tasks. The result confirmed the above observation. We speculate that
the length of a target word may have played a critical rote in this patient's
repetition capability.
PMID- 10689689
TI - [A case of cerebellar meningo-encephalitis caused by Epstein-Barr virus(EBV):
usefulness of Gd-enhanced MRI for detection of the lesions].
AB - We report a patient with cerebellar meningo-encephalitis by Epstein-Barr
virus(EBV) in which the responsible lesions were detected by Gd-enhanced MRI. A
61-year-old woman with a history of liver cirrhosis and diabetes mellitus
presented with cerebellar signs such as ataxia of the trunk, bilateral upper and
lower extremities and slurred speech two weeks after the acute upper respiratory
inflammation for several days. Serum IgM antibody(Ab) to EBV viral capsid
antigen(VCA) was 1:10, Ab to EBV(VCA) IgG was 1:1280, Ab to early antigen diffuse
and restricted (EADR) IgG was 1:40, Ab to EBV nuclear antigen (EBNA) was 1:80.
Other viral antibody titers were not elevated significantly in serum.
Cerebrospinal fluid (CSF) pressure was 195 mmH2O, containing 464 cells/mm3,
protein 68 mg/dl and glucose 43 mg/dl. Only CFS Ab to EBV(VCA) IgG elevated
significantly (1:16). In acute phase plain MRI was normal except for swelling of
the cerebellar hemispheres while Gd-enhanced MRI showed a leptomeningeal
enhancement of bilateral cerebellar hemispheres and of vermis disappeared within
one month. A homogeneously enhanced lesion in the left dentate nucleus appeared
one month after the onset of illness. This lesion had been detected on Gd
enhanced MRI for three months after clinical symptoms were improved. No abnormal
finding was shown in the supratentorial region during the whole clinical course.
In the literature, EBV encephalitis has a wide range of MR findings which may
vary in a short period. We emphasize that frequent MR examinations including Gd
enhanced MRI is useful to evaluate inflammatory or demyelinating diseases in the
posterior fossa.
PMID- 10689690
TI - [A case of herpes zoster encephalitis with Ramsay-Hunt syndrome, herpes zoster
generalisatus and acute pancreatitis].
AB - We describe here a 71-year-old man who had herpes zoster encephalitis. He
developed high fever, headache and disturbance of consciousness on 1st, May,
1998. On admission, neurological examination revealed disturbance of
consciousness with restlessness and meningeal signs. Brain MRI (T 1 and T 2
weighted images) demonstrated high signal lesions in the left temporal lobe and
cerebellar vermis. VSV encephalitis was diagnosed based on CSF pleocytosis, high
serum and CSF titers of VZV antibody and EEG abnormality. During hospitalization,
Ramsay-Hunt syndrome, herpes zoster generalisatus and acute pancreatitis
developed. To our knowledge, the characteristic combination of the clinical signs
in this case is very rare. We discussed the pathogenic mechanisms of these
conditions, and this case was considered to have VZV encephalitis, and to be
associated with right facial nerve palsy and pancreatitis, in spite of the
absence of immunological deficiency.
PMID- 10689691
TI - [Transient improvement in motor function and hemineglect by vestibular
stimulation in a patient with right middle cerebral artery embolism].
AB - A 62-year-old Japanese man presented left hemiparesis and left visuospatial
hemineglect following a right hemispheric stroke. His CTs and MRIs of the brain
revealed a large embolic infarction of the middle cerebral artery territory. A
month after the cerebrovascular event, his weakness of the left lower limb almost
recovered fully. However, his upper limb motor function was still disabled; in
particular, his ability of finger flexion in the left hand was almost lost. Then,
vestibular stimulation using either a cold caloric stimulation to the left ear or
a warm caloric stimulation to the right ear was performed, and the effect on the
hemineglect symptoms were assessed by a line bisection task. After vestibular
stimulation, not only his hemineglect symptoms but also his motor functions of
left upper limb transiently improved; he became able to make a fist. The
improvement of his hemineglect symptoms was obtained by vestibular stimulation
using either a cold or a warm caloric stimulation. However, the effect on the
motor function was obtained only by the cold caloric stimulation applied to the
left ear. Based on the effect of the vestibular stimulation, we postulates that
the impairment of the motor function in the present patient is not only a paresis
caused by the pyramidal tract lesion but also symptoms related to the hemineglect
syndrome.
PMID- 10689692
TI - [A case of rhabdomyolysis with water intoxication confirmed by muscle biopsy].
AB - A 32-year-old woman with chronic schizophrenia who took 8-10 liters of water for
three years due to thirsty, admitted to our hospital because of convulsion and
muscle weakness. Neurological finding on admission showed a mild disturbance of
consciousness, moderate proximal muscle weakness, and muscle pain. Laboratory
examination revealed marked serum hyponatremia(102 mEq/l) and high value of
creatin kinase (1,259 IU/l). The level of creatin kinase reached a peak(39,700
IU/l) at the 5th hospital day. An analysis of the muscle biopsy specimen showed
necrotic muscle fibers and opaque fibers, that was compatible with
rhabdomyolysis. T 2 weighted magnetic resonance imaging of the brain showed a
transient high signals in bilateral putamen but not in pons. She was diagnosed to
have rhabdomyolysis due to water intoxication. The present case is the first
rhabdomyolysis in Japan that was confirmed by muscle biopsy at an acute stage of
water intoxication related with schizophrenia.
PMID- 10689693
TI - [A case of Wernicke-Korsakoff syndrome with dramatic improvement in consciousness
immediately after intravenous infusion of thiamine].
AB - A 68-year-old man was hospitalized on March 4, 1998 for disturbances in
consciousness. In 1995, he had received proximal subtotal gastrectomy and
reconstructive surgery of the jejunal interposition for gastric cancer.
Thereafter he had been taking enough food without the habit of taking liquor. In
October 1997, his short term memory was becoming gradually worse. On February 12,
1998, he suffered from numbness in the feet, and then dysphagia, unsteady gait,
and diplopia developed gradually. On February 26, brain MRI showed no
abnormalities. On March 3, he had a fever of 38.5 degrees C and his consciousness
became unclear. Neurological examination revealed semi-coma, total
ophthalmoplegia, and absence of doll's eye movement. Deep tendon reflexes were
absent. The serum thiamine level was 9 ng/ml (normal range: 20-50). Brain MRI
demonstrated symmetrical high intensity lesions in the periaqueductal area of the
midbrain, dorsomedial nuclei of bilateral thalami, and vestibular nuclei. About
30 seconds after intravenous infusion of thiamine, his consciousness improved
dramatically, but returned to semi-coma after about two minutes. Wernicke
Korsakoff syndrome usually occurs acutely. In the present case, however, the
disease showed slow onset, chronic progression, and then rapid worsening after
fever. Reconstructive surgery of the jejunal interposition might have caused the
slow onset of Wernicke-Korsakoff syndrome, and fever might have facilitated the
rapid progression of the disease. An immediate high concentration of thiamine
modifies the kinetics of acetylcholine receptor ion channels, thereby maintaining
wakefulness, and the level of consciousness may change dramatically.
PMID- 10689694
TI - [An autopsy case of catastrophic antiphospholipid syndrome presenting with
recurrent multiple cerebral infarction associated with lung cancer].
AB - We reported an autopsy case of cerebral infarction with primary lung cancer. The
patient was a 50-year-old man. Despite having been treated with warfarin
potassium and ticlopidine hydrochloride, he relapsed cerebral infarction. His
laboratory data on admission showed that lupus anticoagulant was positive,
together with a high value of beta-thromboglobulin, thrombin-antithrombin III
complex, markers of platelet and coagulation activation, CEA and CA 19-9. The
autopsy finding revealed a primary papillary adenocarcinoma in the right lower
lung, multiple cerebral infarction, renal infarction, pulmonary infarction and
splenic infarction. The atherosclerotic changes were mild in the whole tissues
and findings of vasculitis were not observed. Recurrence of cerebral infarction
was effectively suppressed with the addition of steroid therapy to antithrombotic
therapy. This case was considered as catastrophic antiphospholipid syndrome. It
is necessary to differentiate antiphospholipid syndrome in case of the abnormal
coagulation and fibrinolytic factors with recurrent cerebral infarction.
Moreover, systemic examinations are important, because malignant tumor may exist
on the background of the case.
PMID- 10689695
TI - [Visual functional MRI: a case of intracranial meningioma with hemianopsia].
PMID- 10689696
TI - [Metastatic bone tumor of the clivus].
PMID- 10689698
TI - A serological survey of bovine babesiosis in northern and eastern Zimbabwe.
AB - The geographical distribution of Babesia bovis and Babesia bigemina antibodies in
communal herds in northern and eastern Zimbabwe was determined using the ELISA
technique. The animals in different herds in the study region had different
levels of natural exposure to B. bovis (mean 32%, range 0-79%) and B. bigemina
(mean 52%, range 5-92%) infections. The majority of herds (90%) were endemically
unstable for B. bigemina and 62% were unstable for B. bovis. Natural region 5 and
Manicaland province had the highest seroprevalence of B. bovis infection, while
natural region 5 and Masvingo province had the highest seroprevalence of B.
bigemina infection.
PMID- 10689697
TI - [An autopsy case of bilateral carotid artery occlusion with repetitive epilepsy
and brain atrophy in a senile patient].
AB - A 67-year-old man was referred to us for tonic-clonic convulsions. A review of
his history revealed that he had been hospitalized for loss of consciousness,
hypotension, and suspected apoplexy at age 67. He had experienced prior tonic
clonic convulsions at age 72 and age 74. He had malaria and tuberculosis in his
history but had been otherwise generally well. Physical examination was normal,
and his blood pressure was 100/80 mmHg. Laboratory findings were normal except
alcalinephosphatase (292 U/l) and gamma-glutamyl transpeptidase(60 U/l).
Neurological examination showed alert consciousness, mild upper gaze palsy,
slight right-side hemiparesis and left Babinski signs was present. Cranial
magnetic resonance imaging showed no abnormality, but cerebral angiography
revealed bilateral carotid artery occlusion. There were abundant leptomeningeal
anastomoses, and the posterior communicating artery was supplied by the left
vertebral artery. Electroencephalography showed a spike wave in the temporal lobe
and rebuild-up phenomenon in the right hemisphere. Brain atrophy in the anterior
and temporal lobes progressed, and the patient experienced gradual
disorientation, delirium and hypobulia. He was eventually bedridden. He also
demonstrated repetitive tonic-clonic convulsions. After one convulsion, he
remained unconscious and died of pneumonia. Autopsy revealed thickening of the
intima and internal elastic lamina in the occluded internal carotid artery. The
anterior and middle cerebral arteries showed the same pathological changes.
Multiple small infarctions restricted to grey matter were present in the cerebral
cortex and may have caused the progressive brain atrophy. There was no myelin
pallor in the white matter of the cerebrum. Atherosclerotic changes, senile
plaque, and neurofibrillary tangles were seen but were within normal limits.
These pathological findings were strongly suggestive of moyamoya disease.
PMID- 10689699
TI - The production and evaluation of Pasteurella haemolytica leukotoxin in the
supernatant of submerged cultures in fermenters.
AB - The optimal production of P. haemolytica leukotoxin in the culture supernatant of
a fluid medium is dependent on a number of factors. The leukotoxin has to be
produced by using a strain that is known for its ability to produce high
quantities of leukotoxin, inoculated into the most suitable type of medium at the
correct culture density containing the necessary supplements and harvested after
a certain growth period. The volume in which it is produced may also have an
influence. Two different procedures are described to produce the leukotoxin in 5
to 15-l quantities in RPMI 1640 medium. The first method used to produce
leukotoxin is one that has been repeatedly described since the presence of the
leukotoxin was first established in 1978. Using this method seven batches of
leukotoxin were produced in litre quantities with leukotoxin activity ranging
from 23-67 u/ml. The seed culture inoculum is prepared in brain heart infusion
broth, which is centrifuged before the organisms are inoculated into RPMI 1640
medium containing 3.5% foetal calf serum and incubated for only 1 h in a
fermenter, after, which the leukotoxin is harvested. An improved alternative
method was devised which yielded higher levels of leukotoxin activity by
utilising the ability of the P. haemolytica organisms to grow and produce
leukotoxin during the logarithmic growth phase in a fermenter. A seed culture
harvested in the log phase was prepared in brain heart infusion broth by means of
a series of cultures and inoculated into RPMI 1640 containing 3.5% foetal calf
serum. Three hours of active growth were allowed during which the leukotoxin was
measured by its biological activity and an ELISA assay, and the increase in cell
mass by means of the optical density every 30 min. The average leukotoxin
biological activity measured 260 u/ml and by means of the ELISA test the
leukotoxin concentration measured 315 u/l which is a substantial increase in
leukotoxin production. In comparison the average optical density only measured
0.469 at 650 nm. Previous findings were substantiated that the highest cell
density was not reflected in the highest leukotoxin activity. It is possible to
induce high levels of leukotoxin secretion in submerged cultures with RPMI 1640
medium containing foetal calf serum in the controlled environment of a fermenter
in large enough quantities for use as a vaccine by the improved preparation of
the seed culture inoculum.
PMID- 10689700
TI - Anthelmintic resistance in South Africa: surveys indicate an extremely serious
situation in sheep and goat farming.
AB - Surveys to determine the prevalence and degree of resistance of Haemonchus spp.
of sheep and goats to the available anthelmintics in South Africa indicate that
small ruminant production is entering a crisis situation. Three surveys employing
the faecal egg count reduction (FECR) test to determine resistance were conducted
in some of the main sheep-producing areas in the summer rainfall region of South
Africa, where H. contortus is the principal worm species in sheep. After
analyzing the data recorded in the surveys by six different methods, including
the RESO test at two different levels of confidence, the results obtained in the
least stringent one (geometric mean reduction of the worm egg counts of drenched,
vs untreated group of sheep) are reported in this paper, so that if any bias was
obtained it would be in the favour of the anthelmintic. In Mpumalanga and KwaZulu
Natal there was anthelmintic resistance in Haemonchus spp. on all the 52 farms
surveyed. Sixteen percent of the strains of H. contortus were < 60% susceptible
to three of the four anthelmintics tested, and 8% of the strains were < 40%
susceptible to all four of the anthelmintics. FECR tests of sheep in six
localities in the Lebowa district of Northern Province indicated that even in
previously disadvantaged communities where anthelmintic treatment is less
intensive, anthelmintic resistance is developing, and is possibly at the level at
which the situation on commercial sheep and goat farms in South Africa was 25
years ago. From the data it appears that the level of anthelmintic resistance of
H. contortus in South Africa is possibly the highest that has so far been
recorded in the world and that strains of it are emerging that may soon not be
controllable by treatment with any of the existing anthelmintics. Farmers in the
summer rainfall region, if not the whole country, must be alerted to the
immediate need for testing the parasite burdens of their sheep for susceptibility
to preparations in all four groups of anthelmintic compounds currently available.
Alternative methods of integrated worm control, including biological, must be
sought and implemented with urgency, to reduce further selection for resistance
and to induce reversion of the resistance that has already developed.
PMID- 10689702
TI - Evaluation of coloured targets for the attraction of Glossina brevipalpis and
Glossina austeni (Diptera: Glossinidae) in South Africa.
AB - Studies on the attractiveness of various coloured targets for Glossina
brevipalpis and G. austeni in South Africa showed black and pthalogen blue
(p.blue) combinations to be the most effective for both species. A 2 m wide (all
targets 1 m high) black/p.blue/black (colour ratio 1:2:1) conformation caught
nearly three times more G. brevipalpis and nearly five times more G. austeni than
a 1.5 m wide black standard control target. For G. brevipalpis the
black/p.blue/black (1:2:1) target should be at least 2 m wide in order to
increase catches significantly while a 1.5-2.0 m wide target is optimal for G.
austeni. The p.blue section of a 2 m black/p.blue/black target should not make up
less than 20% of the total target width for either species. The most effective
combination of practical target sizes and colour ratios were a 1.75 m wide
black/p.blue/black (1:1.5:1) or 2 m wide target (1.5:1:1.5). Between 61-95% of G.
brevipalpis and 34-90% of G. austeni that were attracted, settled first on the
black section of black/p.blue targets (> 1 m wide). Further studies revealed that
for G. brevipalpis only the black parts of the 2 m wide target need to be treated
with insecticide, while the entire 1.75 m wide target should be treated. For G.
austeni the total width of either target should be treated with insecticide since
this species readily settles on both blue and black.
PMID- 10689701
TI - A comparison of the infectivity of cryopreserved versus unfrozen infective larvae
of Haemonchus contortus, Trichostrongylus colubriformis and Trichostrongylus
axei. Results of the Onderstepoort Veterinary Institute and collaborators from
1977 to the present.
AB - The infectivity for sheep of cryopreserved infective larvae (L3) of various
strains of Haemonchus contortus, Trichostrongylus colubriformis and
Trichostrongylus axei is compared using previously published results of trials
conducted at the Onderstepoort Veterinary Institute laboratories, and of
collaborators. The means and ranges of development were similar for both frozen
and unfrozen larvae of two of the three worm species reviewed. A mean of 33.4%
(range, 12.7-63.0%) of cryopreserved H. contortus L3 developed, compared to a
mean of 43.7% (range 2.4-78.7%) of unfrozen L3 of this worm species. The
corresponding values for T. colubriformis were 33.0% (range 10.3-62.7%), and
33.5% (range 8.3-52.2%), respectively. In the case of T. axei, the development of
the cryopreserved L3 (tested in only three trials) was markedly lower than that
of unfrozen L3 in the single trial in which the latter was evaluated. It is
concluded that development of cryopreserved L3 is probably similar to that of
unfrozen L3 and that, for several reasons, maintaining nematode larvae in the
frozen state in liquid nitrogen is a much superior method to that of one which
entails cycling worm strains continually in their final hosts.
PMID- 10689703
TI - Evaluation of conventional odour attractants for Glossina brevipalpis and
Glossina austeni (Diptera: Glossinidae) in South Africa.
AB - The components of the synthetic ox-odour used in Zimbabwe against Glossina
pallidipes and G. m. morsitans were evaluated for the attraction of G.
brevipalpis and G. austeni in South Africa. The Zim babwe mixture (Zim-mix),
which consisted or acetone and a 1:4:8 mixture of 3-n-propyl phenol, 4-methyl
phenol and 1-octen-3-ol, increased the catches of G. brevipalpis by c. 2.1-4.4
times compared to when no odours were used. One of the odour components, namely 3
n-propyl phenol, did not significantly increase the size of the catches. Acetone
was an essential component for G. brevipalpis, especially during the warm and wet
season when it acted synergistically with high doses of 1-octen-3-ol and 4-methyl
phenol. The most attractive odour combination for G. brevipalpis was 1-octen-3-ol
released at 2.3-9.1 mg/h with 4-methyl phenol at c. 15.5 mg/h and acetone at c.
350 mg/h. This combination increased the catches by another 2.3-2.8 times when
compared to the Zim-mix and 10.1-12.3 times compared to 'no odour'. None of the
odour components was attractive for G. austeni. None of the components was
repellent for either species.
PMID- 10689704
TI - An anatomical study of the respiratory air sacs in ostriches.
AB - An accurate description of the number, location and relative position of the air
sacs and their diverticula in the ostrich is essential for a better understanding
of the pathogenesis of air sacculitis in this bird. The air sacs were studied in
ten ostriches of varying ages by latex or silicone casting of the respiratory
tract and dissection. Results revealed that the air sacs of the ostrich conform
to the general pattern in birds. Cervical, lateral and medial clavicular, cranial
and caudal thoracic, and abdominal air sacs are present. The left and right
medial clavicular air sacs fuse with each other ventrally to the trachea to form
a single, median compartment. A unique, large gastric diverticulum which covers
the caudal aspects of the proventriculus and gizzard originates from the median
compartment of the clavicular air sac. The lateral clavicular air sacs and their
diverticula are similar to those of other bird species, with the exception that
humeral diverticula are absent. Both abdominal air sacs are relatively small,
with the left sac being the larger. Perirenal and femoral diverticula, similar to
those found in other bird species, are present. However, the entire femur is
aerated by the femoral diverticulum which also forms a large, subcutaneous
division caudally and caudo-laterally to the femur. The presence of this
subcutaneous part has practical implications for injury and intramuscular
injections. The number and location of ostia connecting the air sacs to the
bronchial tree are generally similar to those reported in other bird species.
PMID- 10689705
TI - Evaluation of a proposed odour-baited target to control the tsetse flies Glossina
brevipalpis and Glossina austeni (Diptera: Glossinidae) in South Africa.
AB - The most effective odour attractant for G. brevipalpis Newstead, namely a
combination of octenol released at c. 9.1 mg/h, 4-methyl phenol released at c.
15.5 mg/h and acetone released at c. 350 mg/h, when used together with the
smallest recommended colour target (as determined in previous studies), namely a
1.75 m wide x 1 m high black/pthalogen-blue/black target, was evaluated for the
control of G. brevipalpis and G. austeni Newstead. This combination increased the
catches of G. brevipalpis by 3.5 fold when compared to the number of those caught
on a 1.5 m wide x 1 m high black target baited with a synthetic ox-odour as was
used in a trial to control this species in the Hluhluwe-Umfolozi Game Reserve in
1992. There was an indication that odour (olfaction) plays a far more important
role in attracting G. brevipalpis than does colour (vision). For G. austeni
visual attraction appears to play the major role as the odours used were
relatively unattractive to them. The odour-baited target should, however, attract
G. austeni in sufficient numbers (visually) to achieve control to the fly.
PMID- 10689706
TI - Detection of Mycoplasma gallisepticum and Mycoplasma synoviae antibodies in the
sera of indigenous chickens by rapid serum agglutination test at Mmopane,
Gaborone, Botswana.
AB - The mean flock size was ten chickens per rural farmer. Antibodies to Mycoplasma
gallisepticum and Mycoplasma synoviae were detected in 57.88% and 67.33% of the
chicken sera respectively.
PMID- 10689707
TI - The helminths of ranch calves in the North-eastern Mountain Grassland of South
Africa.
AB - The cumulative total helminth parasite burdens of ranch calves during their first
seven months of life on the North-eastern Mountain Grassland of South Africa were
determined during two consecutive years. Trichostrongylus axei was the most
abundant nematode parasite followed by Cooperia spp. and Ostertagia ostertagi.
Haemonchus spp. occurred in relatively low numbers and its development was
significantly inhibited. The total helminth parasite burdens of the calves ranged
from 681 to 7,269 with a mean of 4,405.
PMID- 10689708
TI - DNA ploidy and prognosis of neuroblastoma.
PMID- 10689709
TI - "To the heart of the matter...".
PMID- 10689710
TI - Lymphokines post autologous peripheral blood stem cell transplantation in
children.
PMID- 10689711
TI - Pediatric hematology and oncology at the University Children's Hospital, Basel,
Switzerland.
AB - The department offers the management and research of benign and malignant
pediatric hematology and oncology at a comparable European standard. It serves as
a referring department for BMT, thoracic and visceral pediatric surgery, and
pediatric orthopedic surgery and is equipped with all facilities of modern
oncology and surgery. Psychooncology is a continuing interest at our department
and may help children and their families to better understand and accept their
situation and to receive the support necessary for coping with the threat of
malignant diseases. Our department aims at practicing a highly sophisticated
communication culture essential for a multidisciplinary approach to the child
with cancer, representing a central condition for the success of the treatment of
malignant diseases.
PMID- 10689712
TI - Persistent altered spermatogenesis in long-term childhood cancer survivors.
AB - This study evaluated male gonadal function in long-term survivors of childhood
cancer and assessed the suitability of offering sperm analysis to all those
patients independently of the diagnosis and treatment received. A total of 43
survivors of acute lymphoblastic leukemia (21), acute myeloid leukemia (1),
neuroblastoma (8), ganglioneuroblastoma (1), ganglioneuroma (2), Wilms' tumor
(9), and mesoblastic nephroma (1) underwent sperm analysis at a mean age of 20.2
years, after a mean time off treatment of 13.6 years. Eight of the patients (19%)
were azoospermic, 2 (5%) were severely oligo-asthenozoospermic, and only 16 (37%)
were normozoospermic. A control group of healthy volunteers aged < or = 30 years
included no azoospermic subjects, 7% severely oligo-asthenozoospermic, and 67%
normozoospermic. Comparisons were also made with patients treated at our Human
Reproductive Unit aged < or = 30 years (n = 373) whose percentages for the above
parameters were 4, 9, and 42%, respectively. Cumulated cyclophosphamide dose and
basal follicle-stimulating hormone (FSH) levels were identified as independent
factors associated with azoospermia or severe oligo-asthenozoospermia.
Azoospermic and severely oligo-asthenozoospermic survivors had significantly
smaller mean testicular volume and higher basal FSH levels than the other
survivors, but small testicles (sum of both testicular volume < or = 20 mL)
and/or abnormally high basal FSH (> 10 mIU/mL) were present in only half of the
azoospermic survivors. Male long-term survivors of childhood cancer constitute a
high-risk subpopulation for altered sperm analysis. It seems justified to offer
sperm analysis to all long-term survivors.
PMID- 10689713
TI - Clinical ineffectiveness of IL-2 and/or IFN alpha administration after autologous
PBSC transplantation in pediatric oncological patients.
AB - Clinical impact of s.c. administration of IL-2 and/or IFN alpha was studied in 23
pediatric patients with Hodgkin lymphoma (IFN alpha group) and sarcoma, non
Hodgkin lymphoma, peripheral neuroepitelioma, neuroblastoma, and embryonic
carcinoma (IL-2 + IFN alpha group) after autologous PBSC transplantation.
Expression of CD3, CD4, CD8, CD25, CD38, CD56, CD71, CD122, and HLA-DR antigens,
serum level of the soluble IL-2R alpha, and NK activity against K562 cell line
were evaluated in 11 patients representative for both types of immunotherapy. T
and, more markedly, NK cell proliferation, induction of activation markers on the
surface of T and NK subsets, and elevation of sIL-2R alpha concentrations were
seen in the IL-2 + IFN alpha subgroup. In the IFN alpha subgroup, the total
number of lymphocytes and expression of activation markers remained unchanged,
but the number of CD8+ T cells increased at the expense of CD4+ T and NK cells
during the therapy. Cytotoxic activity against K562 cells was not influenced by
the immunotherapy in either subgroup. No significant clinical benefit of the
immunotherapy was seen in these patients compared to 27 control patients with
relevant diagnoses who did not receive immunotherapy.
PMID- 10689714
TI - DNA content and proliferative activity in children with neuroblastoma.
AB - Many studies have reported that neuroblastoma patients with aneuploid DNA content
and a low cellular proliferative activity have better outcome; other studies have
reported contradictory results. Formalin-fixed, paraffin-embedded archival
pretreatment specimens of 56 neuroblastomas were studied. Thick sections from
paraffin blocks were deparaffinized, and rehydrated. Following enzymatic
digestion and filtration, cellular suspensions were analyzed by flow cytometry.
Six tumors were aneuploid (13.3%) and 39 samples were diploid (86.7%). S-phase
fraction (SPF) ranged from 1 to 78% with a median of 31%. DNA ploidy and
proliferative activity results showed no correlation with the prognostic
variables. There was no significant difference between the 5-year overall and
event-free survival rates of the aneuploid and the diploid neuroblastomas or
between the neuroblastomas with a high and low proliferative activity. The
results revealed the prognostic significance of neither DNA ploidy nor the
cellular proliferative activity in neuroblastoma in contrast to other studies.
PMID- 10689715
TI - Use of alternative therapy among pediatric oncology patients in Taiwan.
AB - Both alternative medicine and western medicine have been commonly used to treat
pediatric cancer patients in Taiwan. Each has its own intrinsic strengths and
weaknesses and they can be complementary. Little is known about medical help
seeking behaviors of parents of pediatric cancer patients, especially those
related to alternative therapies. This study investigated the extent and parental
expectations on use of alternative therapies. All primary caregivers of 63
eligible patients were interviewed. Use of alternative therapies, regardless of
education level or social status of their families, is prevalent (n = 46, 73%) in
Taiwan. Commonly used alternative therapies included, in order of popularity,
formulated functional food (n = 22, 48%), temple worship/shamanism (n = 19, 40%),
traditional Chinese medicine (n = 9, 20%), secret recipes/herbs (n = 13, 28%),
and diet supplements (n = 9, 19%). Such practices generally occur without medical
guidance from oncologists, largely because of poor interactions between parents
and oncologists. Future efforts should be made to encourage both parents and
oncologists to discuss this issue. Nurses may serve as mediators by developing
mutual trust and a sharing relationship between these groups.
PMID- 10689716
TI - Changes in the policies of the department of hematology, 1982-1998, designed to
promote the mental health of children with leukemia and enhance their quality of
life.
AB - A perceived personal control (PPC) preventive intervention model that had earlier
received empirical and theoretical verification was applied to a population of
pediatric leukemia patients to promote their mental health and enhance their
quality of life. The PPC model entails intervention on two complementary levels.
On the personal interaction level, preventive intervention is administered by a
network of natural and organized support systems, while the social action level
leads to the introduction of changes in policies, structures, allocation of
resources, and services. Preventive intervention in both domains is discussed
with respect to changes in policies introduced between 1982 and 1998 in the
hematology department of Rambam Medical Center in Haifa, Israel, as well as in
other relevant departments catering to children with leukemia, to foster the
positive mental health of these children.
PMID- 10689717
TI - A longitudinal study of cardiac function in children with cancer over 40 months.
AB - A previous study demonstrated impaired systolic function in 29% of patients
treated with anthracycline as part of their therapy for malignant disease. A
follow-up echocardiographic study was performed to determine whether there had
been further deterioration of cardiac function. At least 40 months after the
first study, those patients in whom abnormal systolic function had been detected
and who had not received further anthracycline were studied by echocardiography
using the same protocol as the initial study (group A). A second group of
pediatric oncology patients who had not been given anthracycline but who had
previously had cardiac assessment was selected as a control group (group N). The
age and sex distributions of the two groups were comparable. Group A comprised 29
patients assessed on 2 occasions at mean times of 46 months and 89 months from
the last dose of anthracycline. The mean dose of anthracycline received was 233
mg/m2 (range 20-400). Nine of 16 patients and 4 of 5 patients who had abnormal
ejection fraction (EF) and fractional shortening (FS) at first assessment had
normal EF and FS at the second assessment. There were no significant changes in
EF, FS, and left ventricular wall stress (LVWS) between the two examinations. In
group N, 20 patients were assessed after a mean interval of 43 months. There were
no significant changes in EF, FS, or LVWS between the two examinations. At the
first but not the second examination there were significant differences in the
left ventricular internal diameters, EF, FS, and LVWS between group A and group
N. Mildly abnormal cardiac indices detected in children after cessation of
treatment with anthracycline did not deteriorate in 3 to 4 years follow-up. A
longer cardiac follow-up study is indicated to assess the late outcome.
PMID- 10689718
TI - Pediatric thyroid carcinoma: 22 years of experience at the Northern Israel
Oncology Center (1973-1995).
AB - Over the past 22 years, 16 children with thyroid carcinoma were referred to the
Northern Israel Oncology Center. All patients had undergone surgical procedures,
either total or subtotal thyroidectomy, and 7 patients had undergone cervical
lymph node dissections. Postoperatively, 5 patients underwent thyroid ablation
with radioactive 131I as first treatment. Two patients received postoperative
external radiation therapy to a field encompassing the cervical region, superior
mediastinum, and both supraclavicular grooves. After a median follow-up of 60
months (range, 5-169 months), all patients are alive with no evidence of
recurrent disease. Two patients who had recurrences, one in the submaxillary
lymph nodes and one in the lungs, were salvaged successfully with retreatment
with 131I therapy. No severe acute or long-term side effects were exhibited. The
long-term results of treatment of pediatric thyroid carcinoma are excellent, but
there remains disagreement over the extent of surgical and postsurgical treatment
required.
PMID- 10689719
TI - Antibiotic sequential therapy for febrile neutropenia in pediatric patients with
malignancy.
AB - Children suffering malignant diseases can experience phases of bone marrow
depression during intensive chemotherapy. The influence of antibiotic sequence
therapy on the course of diseases was examined in 41 pediatric patients with
malignant diseases. Inclusion criteria were neutropenia (ANC < 500/microL),
rectal body temperature over 38.5 degrees C, and increased C-reactive protein
(CRP, cutoff > 5.0 mg/L). The first stage of therapy comprised the following
antibiotics: piperacillin, teicoplanin, and gentamicin. In stage 2 imipenem,
teicoplanin, and tobramycin were administered. Fluconazole was the antifungal
drug of choice in stages 1 and 2. In the first level of antibiotic therapy 68% of
the patients showed a positive reaction. The C-reactive protein was a sensitive
parameter, which significantly decreased with 3 days of therapy. A total of 72%
of the bacteriological smears were sterile. All patients survived the septic
phase.
PMID- 10689720
TI - Neutropenic enterocolitis in children with acute lymphoblastic leukemia.
AB - Neutropenic enterocolitis is an acute, life-threatening inflammation of the small
and large bowel, often seen in children with malignancies during periods of
prolonged or severe neutropenia. During the period 1990-1995, 180 children were
treated at the authors' center for acute lymphoblastic leukemia using a standard
chemotherapy protocol. Among them, 11 children (6.1%) aged 4 to 12 years, were
diagnosed clinically to have neutropenic enterocolitis. Eight had severe
neutropenia (absolute neutrophil count < 10(8)/L and 5 had prolonged neutropenia
(> 7 days duration). The symptoms included diffuse abdominal pain (10 children),
oral mucositis (7), hematochezia (7), diarrhea (6), hematemesis (5), and right
lower quadrant tenderness (4). Three children had radiological evidence of free
intraperitoneal gas and an additional 3 children were found on surgical
exploration to have cecal perforation. Laparotomy was performed on 8 children
(73%), 4 of whom survived. Among the 3 children managed conservatively, 1 died
awaiting surgical exploration, while the other 2 did well. The overall survival
was 55%. The authors recommend an approach to management that respects the
heterogeneity of the disease.
PMID- 10689721
TI - Testicular germ cell tumors in prepubertal children.
AB - Pediatric testicular germ cell tumors are rare. Fifteen children, all less than 5
years of age, were evaluated and treated during February 1987 to July 1996. The
median age was 18 months (range, 4-60 months). All were staged according to the
Pediatric Oncology Group/Children's Cancer Study Group staging system. Seven
patients had stage III disease. Histologically, 9 patients had pure endodermal
sinus tumor, 1 had endodermal sinus tumor with embryonal carcinoma, 1 had
embryonal carcinoma alone, 2 had immature teratoma, and 2 had mature teratoma.
Six children were kept on surveillance. All others received chemotherapy with
cisplatin, bleomycin, and vinblastine. The 10-year actuarial overall survival
rate was 86.7%.
PMID- 10689722
TI - Pneumomediastinum, subcutaneous emphysema, and pulmonary fibrosis in a patient
with idiopathic pneumonia syndrome after bone marrow transplantation.
AB - An adolescent female underwent bone marrow transplantation for relapsed leukemia
and developed acute and chronic graft-versus-host disease and idiopathic
pneumonia syndrome. Her lung disease responded to large doses of
methylprednisolone but evolved to pulmonary fibrosis and pneumomediastinum and
subcutaneous emphysema in the convalescent period. Pulmonary function tests
revealed a restrictive pattern. Pneumomediastinum and subcutaneous emphysema are
complications not only of obstructive but also of restrictive lung disease and
vary with respect to time of onset.
PMID- 10689723
TI - Nutritional strategies in cardiovascular disease control: an update on vitamins
and conditionally essential nutrients.
AB - Several nutritional interventions for cardiovascular disease (CVD) prevention and
therapy have recently appeared in the biomedical literature. These include
appropriate use of several vitamins (E, C, B6, folate) and conditionally
essential nutrients (CoQ10, L-arginine, propionyl L-carnitine). Possible
undesirable consequences of long term nutritional supplementation with vitamin E
and of adverse drug-nutrient interactions between the statins and CoQ10 are also
considered. Although additional intervention studies are needed, current
scientific evidence generally supports nutritional supplementation with these
nutrients as an effective adjunctive strategy for CVD control.
PMID- 10689724
TI - Reliability and validity of the Food Pyramid Self Efficacy Scale: use in coronary
artery bypass patients.
AB - Inappropriate dietary intake is associated with 5 of the 10 leading causes of
U.S. death; coronary artery disease (CAD) ranks highest regardless of gender in
people over the age of 65. Of the modifiable risk factors for CAD, two of four
pertain to food choices. Although lifestyle habits can enhance or impair health,
people's beliefs that they can motivate and regulate their own behavior (self
efficacy) plays a crucial role in whether they even consider changing detrimental
health habits. The Food Pyramid Self Efficacy Scale (FPSES) is an instrument to
measure an elder's confidence in his/her ability to choose healthy food items in
a variety of situations. The purpose of this study was to determine the
reliability and validity of the FPSES. Thirty postoperative CABG patients
participated (mean age 70.4). FPSES test-retest (r = 0.78, p = 0.008);
coefficient alpha = 0.92. Six content experts judged the FPSES (content validity
index [CVI] = 0.85). Construct validity of the instrument was achieved through
hypothesis testing, supporting the statement that the higher the nutritional
risk, the greater the functional decline (r = 0.37, p = 0.05). As many of the
health problems associated with the elderly are preventable or controllable
through health promotion, it is vital that measures exist to determine a person's
confidence that one believes in the capability to change to healthy eating
behaviors.
PMID- 10689725
TI - Suppose a Perclose.
AB - The development of coronary interventional strategies and devices has provided an
alternative to surgery for coronary artery disease. The femoral artery is the
most common access site for therapeutic cardiac interventions. The methods to
achieve hemostasis post procedure vary from conventional, where the arterial
puncture site is externally compressed, to novel, where the femoral artery is
sealed with a device. One such device is a suture mediated percutaneous vascular
closure system developed by Perclose, Incorporated. It provides a safe, effective
method to achieve immediate hemostasis of the femoral artery. The vascular
complication rate is only 0.78%, time to hemostasis is within 1.3 minutes, and
time to ambulation in within 5.5 minutes. These advantages provide improved
patient comfort and have a positive economic impact.
PMID- 10689726
TI - Collaboration, problem solving, reevaluation: foundation for the Heart Center of
Excellence.
AB - Today's rapidly changing health care environment has thrust upon the caregivers,
patients, and their families many challenges. A multidisciplinary team
continuously analyzes strengths, weaknesses, and threats to the success of heart
centers. Prolonged hospitalization for cardiac surgery patients is consistently
identified as a priority with multiple opportunities for improvement. All
patients are monitored for variables known to impact length of stay including
same day admission, intubation time, out of bed interval following extubation,
and delay in postoperative transfer to the progressive cardiac care unit (PCCU).
Utilizing collaboration, problem solving, and reevaluation, known as CPR
techniques, postoperative intubation time, and the out of bed interval following
extubation, have both dramatically decreased. Despite declines in elective, same
day admissions and fewer first day postoperative transfers, length of stay
following cardiac surgery has also declined. The continuum of patient care has
been established from preadmission to postdischarge and up to one year following
cardiac surgery. Utilizing CPR techniques allowed us to achieve a best practice
model for successfully improving outcomes in heart centers.
PMID- 10689727
TI - Effective treatment of severe hypertension.
PMID- 10689728
TI - New guidelines for the management of hypertension: latest perspective on an old
problem.
PMID- 10689729
TI - The Working Group on Cardiovascular Nursing: a European forum for international
collaboration in cardiac care.
PMID- 10689730
TI - What is the most common arrhythmia following cardiac revascularization?
PMID- 10689731
TI - Is aggressive lipid lowering as effective as angioplasty in some cardiac
patients?
PMID- 10689732
TI - Differentiation and proliferation of pulmonary neuroendocrine cells.
AB - In this review article the morphological profiles of pulmonary neuroendocrine
cells (PNEC) in experimental animals and humans are described. Although the
mechanisms of differentiation and proliferation of neuroendocrine cells in the
airway epithelium remain to be solved, several experimental studies using explant
culture and cell culture systems of fetal animal lungs have been performed to
clarify fundamental phenomena associated with neuroendocrine differentiation and
proliferation. Experimental animal studies using chronic hypoxia, toxic
substances and carcinogens have succeeded in inducing alterations in PNEC
systems, and these studies have elucidated the reactions of PNEC in cell injury
and inflammation, and functional aspects of PNEC in disease conditions. Human
pulmonary neuroendocrine tumors include various histological subtypes, and show
divergent morphological and biological varieties. Molecular abnormalities of
small cell carcinoma, the most aggressive subtype of pulmonary neuroendocrine
tumors, have been extensively studied, but the mechanism of neuroendocrine
differentiation of this tumor is still largely unknown. PNEC share common
phenotypes with neuronal cells, and developmental studies have begun contributed
evidence that similar transcriptional networks, including active and repressive
basic helix-loop-helix (bHLH) factors, function in the differentiation of both
PNEC and neuronal cells. Such a bHLH network may also play a central role in
determining cell differentiation in lung carcinomas. Further studies of the
neuronal bHLH network, its regulatory system and related signal transduction
pathways, will be required for understanding the mechanisms of neuroendocrine
differentiation and proliferation in normal and pathological lung conditions.
PMID- 10689733
TI - [The Wiener klinishce Wochenschrift at the beginning of the 3rd century].
PMID- 10689734
TI - [Pathophysiology of acute renal failure at the cellular level].
AB - The influence of inflammation on post-ischemic acute renal failure (ARF) has only
recently be appreciated. In this review we therefore discuss the cellular events
occurring in ARF with special emphasis on the impact of inflammatory processes on
the pathogenesis of ARF. Furthermore, the spectrum of injury leading to sublethal
or lethal cell damage and the time course, occurrence and regulation of the two
distinct forms of cell death, necrosis and apoptosis will be described
extensively. Especially apoptosis and its regulation has been studied only
marginally in the setting of ischemic ARF. This overview is mainly focused on
tubular cell injury since tubular epithelial cells are the major victims of
ischemia whereas cells inside the glomerular tuft show only little pathology. The
models of tubular injury described in this paper are ranging from primary
cultures of isolated human tubular epithelial cells to experimental ischemic
renal failure in rats, and to clinical settings of human ischemic ARF. The
cellular events highlighted in this review are the influence of the expression of
cellular adhesion molecules on the pathophysiology of ARF, and the regulation and
time course of apoptosis. Examples of these processes are being illustrated by
figures exhibiting morphology and immunohistochemistry of cell proliferation and
cell death regulatory proteins.
PMID- 10689735
TI - Normalization of orbital arterial blood flow in non-ischemic central retinal vein
occlusion after 6 months.
AB - INTRODUCTION: Central retinal vein occlusion (CRVO) is a common vascular disorder
and may lead to blindness. The aim of the study was to obtain information about
the possible imbalance and recovery of orbital arterial blood flow in non
ischemic CRVO. METHODS: Vascular resistance (pulsatility index-PI) in the orbital
arteries of 14 patients with non-ischemic CRVO was examined within 3 weeks after
onset of CRVO and 6 months later. The control group consisted of 14 age- and sex
matched healthy control eyes. RESULTS: PI was increased in all orbital arteries
of CRVO eyes measured within 3 weeks after the onset. Normal PI values were
recorded in the same retrobulbar arteries, and re-measured 6 months later.
DISCUSSION: There is an increase in vascular resistance in all orbital arteries
at the onset of non-ischemic CRVO, followed by a recovery of vascular resistance
to normal levels 6 months later. The increase at the onset may be caused by
arterial vasospasm or by intraocular hemostasis affecting the afferent arteries.
PMID- 10689736
TI - Histochemical changes in the rectal mucosa of diabetic patients with and without
diarrhea or constipation.
AB - Sixty-four diabetic patients, 35 with diarrhea, 15 with constipation and 14
without stool problems, and forty healthy subjects, were subjected to
rectosigmoidoscopy. During rectosigmoidoscopy, rectal biopsy specimens for
histological and histochemical analysis were obtained. Histological findings of
nonspecific colitis in 25 out of 64 diabetic patients were uniformly distributed
among the three groups (p = 0.959). However, the finding was slightly more common
in diabetic patients than in controls (eight out of 40 control subjects, p =
0.043). A positive PAS reaction was observed in 30 out of 64 diabetic patients
and was also uniformly distributed among the three groups (p = 0.508), but was
significantly more common among diabetic patients than controls (three out of 40,
p < 0.001). A positive reaction to cholesterol was found in 46 out of 64 diabetic
patients, also uniformly distributed among the three groups (p = 0.773). It was
significantly more common in diabetic patients than in controls (nine out of 40,
p < 0.001). Reactions of the rectal mucosa histological specimens to glycogen and
triglycerides were negative, both in diabetic patients and in controls. In
conclusion, it appears that stool problems among our diabetic patients were not
related to the positivity of PAS or to the positive cholesterol reaction in the
rectal mucosa histological specimens. Since positive findings of both reactions
were more common in specimens taken from diabetic patients than in controls,
positive reactions might be related to metabolic disturbances in diabetic
patients.
PMID- 10689737
TI - [Pericardial effusion in celiac disease--an incidental finding?].
AB - OBJECTIVE: Ultrasound revealed evidence of pericardial effusion in 13 out of 26
children with coeliac disease. In a prospective study, we tried to analyse the
causes underlying this high incidence of pericardial effusion. PATIENTS AND
METHODS: Twenty-six patients were evaluated. Coeliac disease was diagnosed by
intestinal biopsy. All children underwent sonography and a laboratory work-up
including endomysial antibodies and serum selenium and iron concentrations.
RESULTS: Patients with pericardial fluid showed no difference compared to those
without effusion in regard to ECG, chest x-ray, red and white blood cell count,
serum enzymes, serum protein as well as iron levels. The mean value of serum
selenium was lower and endomysial antibody titre was higher in patients with
pericardial effusion. However, due to the wide range, a clear distinction between
the two groups was impossible. In all other investigated parameters there was no
difference between patients with and without pericardial effusion. Patients with
effusion had a higher frequency of viral infection. CONCLUSION: The high
incidence of pericardial effusion in patients with coeliac disease appears to be
governed by a multifactorial mechanism. A high endomysial antibody titre as well
as selenium deficiency may play a role as a predisposing factor. Viral infection
due to reduced immunological competence in conjunction with a hampered ability to
eliminate toxic free radicals might cause blood vessel dysfunction, resulting in
(asymptomatic) pericardial effusion. The fact that most of these patients were
diagnosed during the cold season, with anamnestic evidence of viral infection
shortly before the diagnosis, and the fact that adult patients with dilative
cardiomypathy show a greater prevalence of coeliac disease, supports the view
that coeliac disease is systemic in nature.
PMID- 10689738
TI - Pancreatic elastase 1 in stool: variations within one stool passage and
individual changes from day to day.
AB - Concentration of fecal pancreatic elastase 1 has been claimed to be a highly
sensitive and specific noninvasive test for exocrine pancreatic function. The aim
of our study was to investigate variations in elastase concentration within one
stool passage and from day to day. For the analysis of the variation of fecal
elastase within one stool passage, we utilized 3 different samples collected from
8 patients. Further, we assessed the individual day to day variation of fecal
elastase using stools collected on 3 consecutive days from 40 patients. For the
determination of pancreatic elastase 1 in stool we used an ELISA kit. We found a
relatively considerable variation of fecal elastase concentration within one
stool passage (n = 8, mean CV = 22%, range 4.6-83.1%) and from day to day (n =
40; mean CV = 26%, range 2.4-61.1%). Therefore, we recommend routine analysis of
more than 1 stool sample collected on different days for fecal elastase and to
use a borderline area of +/- 25% of the recommended cut off of 200 micrograms/g
stool for the diagnosis of pancreatic insufficiency.
PMID- 10689739
TI - [Josef Weinlechner (1829-1906). Pioneer in Vienna pediatric surgery].
AB - The history of paediatric surgery in Vienna has not been clearly documented so
far, especially its development during the second half of the nineteenth century.
Josef Weinlechner (1829-1906) is one of the outstanding paediatric surgeons in
Vienna during this time. We present an overview of his biography, his position as
head of the department of surgery at the St. Anna Children's Hospital, and also
discuss his publications concerning various aspects of paediatric surgery. Of
particular interest was the discovery of his application for the qualification of
a postdoctoral lecturer ("Habilitation") in the archives of the University of
Vienna. In this application, Weinlechner refers to his specialisation as that of
a paediatric surgeon.
PMID- 10689740
TI - [Austrian Society of Lung Diseases and Tuberculosis: Consensus on Management of
Chronic Obstructive Lung Diseases (COPD). 1999 Revision].
PMID- 10689741
TI - Sponsored congress attendance--does it happen, does it matter?
PMID- 10689742
TI - Complimentary journeys to the World Congress of Gastroenterology--an inquiry of
potential sponsors and beneficiaries.
AB - One of the most effective tools of pharmaceutical marketing is the distribution
of gifts to physicians whose magnitude remains ill defined. This anonymous survey
determines the frequency with which physicians receive travel awards from drug
companies to attend International Medical Conventions and attempts to obtain the
recipients' opinion on ethical and legal issues related to such sponsorships.
METHODS: A questionnaire was mailed to all members of the German
Gastroenterological Association who had attended the most recent World Congress
of Gastroenterology and to 30 pharmaceutical companies. Questions concerned the
physician's role at the congress, the mode of payment for travel, lodging and
convention fees as well as the attendees' opinion on ethical and legal issues
related to sponsoring by pharmaceutical companies. RESULTS: 78% of the contacted
physicians returned the questionnaire. 67% (95% CI [55, 80]) of them received
compensation for their travel expenses by industry, and the majority of them
stated that they would not have attended the congress if such sponsoring had not
occurred. More than two thirds believed that sponsoring by drug companies neither
interferes with ethical and legal issues nor affects prescribing behavior. Such
opinions were more frequently expressed by sponsored than nonsponsored attendees
(p = 0.003). 20% of the contacted drug companies returned the questionnaire, one
of whom expressed concerns regarding the ethics of sponsorships. CONCLUSIONS:
International conventions would suffer from a significant deprivation of
attendance if the attendees' expenses were not subsidized by industry.
Recognition of ethical and legal issues related to such sponsoring appears to be
limited and requires further discussion within the medical community.
PMID- 10689743
TI - Accuracy of 13C-urea breath test in clinical use for diagnosis of Helicobacter
pylori infection.
AB - The 13C-urea breath test (UBT) is a noninvasive test for diagnosis of
Helicobacter pylori infection of gastric mucosa. The aim of this prospective
study was to assess the accuracy of a simple UBT in clinical routine use.
METHODS: The study population comprised of 100 patients (49 f, 51 m) requiring
diagnostic upper GI endoscopy. One biopsy specimen was taken from the gastric
antrum, body and fundus, respectively, for standard histological examination and
one additional specimen from each location was transformed into transport medium
for cultivation of H. pylori. After vaccination of the culture plates the
biopsies were tested for urease activity (UAT). After recovery from endoscopy the
patients had to pass an one liter endexspiratory breath sample before and 15 min
after drinking 200 ml orange juice, pH 3.6, containing 75 mg of 13C-urea. 13CO2
was measured in the breath samples using isotope-selective nondispersive infrared
spectrometry. RESULTS: Defining gold standard groups with all biopsy tests (from
antrum and corpus) positive or negative the 13CO2 delta over baseline (DOB) cut
off level of UBT was set at 6.5/1000 in order to best discriminate positive from
negative patients (ROC analysis). UBT was positive in 37% of all subjects. Taken
UAT and histological examination together (positive when both tests were
positive) UBT displayed a sensitivity of 92%, a specificity of 94%, a positive
predictive value of 89%, and a negative predictive value of 94%. When including
the results of culture sensitivity and negative predictive value reached almost
100%. The mean of the 13CO2-DOB values from H. pylori-positive duodenal or
gastric ulcer patients did not differ from controls (H. pylori-positive patients
without lesions). The 13CO2-DOB values of the ulcer group were correlated
significantly with the active inflammatory component of gastritis in antrum,
corpus, and fundus. CONCLUSION: UBT with this setup detects H. pylori infection
in clinical routine use with high accuracy. The increase of exhaled 13CO2 does
not predict ulcer disease but reflects the degree of active inflammation of
gastric mucosa.
PMID- 10689744
TI - [Fluorescence endoscopy in gastroenterology].
AB - Fluorescence endoscopy is a new technique which allows a better endoscopic
detection of nonvisible or difficult detectable malignant or premalignant
lesions. Exogenously applied sensitizers accumulate selectively in malignant
lesions and induce fluorescence after illumination with light of adequate
wavelength. However, also endogenous fluorophores, different located in malignant
or benign lesions, induce a different autofluorescence in these tissues.
Meanwhile fluorescence endoscopy is a widely spread technique in urology using 5
aminolevulinic acid sensitization. In gastroenterology this technique seems
promising in the detection of early cancers or dysplasia in patients with
Barrett's esophagus or ulcerative colitis. This paper describes the current
status and future development of fluorescence endoscopy in gastroenterology.
PMID- 10689745
TI - [The liver and hereditary hemorrhagic telangiectasia].
AB - Hereditary hemorrhagic teleangiectasia, or Rendu-Osler-Weber syndrome, is an
autosomal dominant inherited disease characterized by vascular derangement in
many organs. The vascular derangement includes teleangiectases, arteriovenous
fistulas and aneurysms. Liver involvement in hereditary hemorrhagic
teleangiectasia is a rare and sometimes severe disease which was unknown and
mostly detected at autopsy until a few decades ago. Typical findings are vascular
malformations and connective tissue formation with fibrosis and atypical
cirrhosis. In the last years we observed five Osler patients with exclusive or
prevailing involvement of the liver. An unambiguous diagnosis can be ascertained
by means of a hazardous liver puncture with typical histological findings.
Angiography allows a reliable identification of even minor vascular deformities.
The present study was undertaken to demonstrate the courses of disease, the
techniques of examination and the therapeutical options of this rare
manifestation of Osler-disease. In every case one could observe hepatic
malformations which were established as typical Osler findings with the
assistance of histological and above all sonographical/color-Doppler
sonographical devices. These special sonographic/color-Doppler-sonographic
features make it possible to give up the histological diagnostics or exhaustive
investigations by means of angiography, computer-tomography or MRI.
PMID- 10689746
TI - Mechanic intestinal obstruction--a possible presentation of perforated
appendicitis.
AB - A 61-year-old man presented with diffuse abdominal pain, diarrhea, vomiting and
fever. On the initial diagnosis of gastroenteritis the patient received the
antibiotic ofloxacine for one week. On admission plain abdominal radiograph
suggested a mechanic intestinal obstruction. In computed tomography a
conglomerate tumor in the ileocecal region was seen and the patient underwent
laparotomy. The conglomerate tumor was mobilized and an abscess opened, which was
caused by a perforated appendicitis. After the operation the patient improved
immediately and had an uneventful postoperative course. He was released and did
not suffer from gastrointestinal symptoms the following 16 months of follow-up.
The present case shall set forth that perforated appendicitis can clinically
present as intestinal obstruction. Although a rare complication, perforated
appendicitis should therefore even be considered in cases of mechanic intestinal
obstruction of unknown cause.
PMID- 10689747
TI - [Pneumopericardium and retroperitoneal and scrotal emphysema after endoscopic
papillotomy].
AB - Retroduodenal perforation is considered a rare but serious complication of
endoscopic papillotomy. We report on a patient suffering from a stenotic
occlusion of the ductus hepatico-choledochus on whom a pre-cut via needle-knife
was performed in order to place a stent. Hours after the procedure, the patient
developed an extensive pneumoretroperitoneum, pneumopericardium and scrotal
emphysema. The later have not been reported in relevant literature so far.
PMID- 10689748
TI - [Colorectal carcinoma: prevention and early detection in an asymptomatic
population--prevention in patients at risk--endoscopic diagnosis, therapy and
after-care of polyps and carcinomas. German Society of Digestive and Metabolic
Diseases/Study Group for Gastrointestinal Oncology].
PMID- 10689749
TI - [New developments in therapy of chronic hepatitis B. When are nucleoside analogs
indicated?].
AB - Nucleoside analogues are promising agents for the treatment of chronic hepatitis
B infection (HBV-DNA-positive by hybridization assay). The drug being studied
most intensively is Lamivudine (Zeffix) which has recently been approved in
Germany. When given orally once daily (100 mg) Lamivudine is well-tolerated and
suppresses HBV-DNA to undetectable levels in the majority of patients. Since
relapse is frequent when medication is stopped long-term treatment (at least
until seroconversion of HBeAg) is warranted. Indications for lamivudine
monotherapy are patients with chronic hepatitis B in which interferon (IFN) is
contraindicated or patients who did not respond to a previous course of
interferon. Further indications are the HBV-DNA-positive cirrhosis prior to liver
transplantation (OLT) and the HBV-reinfection after OLT. The main problem of long
term monotherapy with lamivudine is viral resistance. The clinical impact of the
resistant mutants is often not clear. Withdrawal or even continuation of the
medication may be acceptable approaches. Other nucleoside analogues like
Entecavir or Adefovir are currently being tested in clinical studies. Famciclovir
was investigated preferably in patients with decompensated liver disease or HBV
reinfection after OLT. Because of conflicting results the drug should only be
used under study conditions. In IFN-naive patients with chronic hepatitis B (and
compensated liver disease) alpha-interferon is still the first-line therapy. With
a standard course of interferon 30-40% of the patients become seronegative for
HBeAg as compared with 16-17% when treated with lamivudine for twelve months.
Combination of lamivudine and interferon is not more effective than IFN alone. In
the future combined antiviral treatment is likely to replace monotherapy.
PMID- 10689750
TI - [The MACH2 Study: value of inhibiting gastric acid secretion in eradication of
Helicobacter pylori with a one week triple therapy protocol].
PMID- 10689751
TI - [The value of botulinum toxin injection in treatment of achalasia].
PMID- 10689752
TI - [High fiber diet or not, that is the question here--comments on prevention of
colorectal carcinoma by dietary fiber].
PMID- 10689753
TI - [Comment on consensus report: Irritable bowel syndrome--definition, verifying the
diagnosis, pathophysiology and therapeutic options].
PMID- 10689754
TI - Silica and lung cancer: hazard or risk.
PMID- 10689755
TI - Epidemiological evidence on the carcinogenicity of silica: factors in scientific
judgement.
AB - In view of the extended debate and differing opinions on whether crystalline
silica is a human carcinogen, we have reviewed a selection of epidemiological
reports, to identify the areas of uncertainty and disagreement. We have chosen to
examine the papers which in a recent review were considered to provide the least
confounded examinations of an association between silica exposure and cancer
risk. We also refer to a study of the mortality of coalminers very recently
reported by ourselves and colleagues. We find that parts of the evidence are
coherent but there are contradictions. On examination this resolves mostly into
differences between types of studies. The three types of epidemiological study
included are: (i) exposure-response studies, the most powerful for the
confirmation of a relationship between a specific exposure and a health effect;
(ii) descriptive studies in which incidence of disease in an exposed population
is compared with that in a reference population; and (iii) studies of incidence
of disease in subjects on silicosis case-registers. Descriptive studies
frequently though not invariably suggest an excess lung cancer risk in silica
exposed workers compared with the general population, but exposure-response
studies consistently fail to confirm that the cause is exposure to quartz. A
single exposure-response study of cristobalite suggests a positive relation. Both
sets of evidence have weaknesses. There are uncertainties on whether the excess
risks in the descriptive studies are related to silica exposure or to lifestyle,
including smoking habits. There are doubts on whether the exposure estimates in
some of the exposure-response studies were sufficiently reliable to detect a
small risk or weak association, though they are unlikely to have missed a strong
effect. Studies of subjects on silicosis case registers consistently show an
excess of lung cancer, but it is not clear to what extent these increased risks
represent a direct effect of silica exposure, a secondary effect of the
silicosis, preferential inclusion of subjects suffering from the effects of
smoking, or bias in diagnostic accuracy. This not unnaturally leads to
differences in opinion, exacerbated by variations in the strength of proof
required by different experts. The main scientific uncertainties in the evidence
are: 1. Whether, in the descriptive studies, the excess lung cancer rates in
silica-exposed workers are explicable in terms of smoking habits, socio-economic
class differences and inappropriate comparison populations. Better smoking
information and more carefully chosen comparison populations are needed; 2.
Whether the exposure-response studies could have missed a real relationship
between silica exposure and lung cancer, if one exists. Many of the exposure
response studies were conducted with great care, but weaknesses, in the available
data on which the exposure estimations were based, could have caused a real
relationship of lung cancer and silica exposure to be missed. These studies were
sufficiently powerful to demonstrate relationships of silica exposure with
silicosis and silico-tuberculosis, so it is unlikely that they would have missed
any but a small risk, or weak relationship, for lung cancer. Our own recent study
of coalminers used uniquely detailed and reliable exposure data, and failed to
demonstrate convincingly an increased risk. This negative finding, though,
applies only to a dust in which the proportion of quartz in the dust is usually
less than 10%. Exposure-response studies are needed, with high quality exposure
estimates, in populations exposed to respirable dust of which crystalline silica
comprises more than 10%; 3. Whether the excess cancer risks in subjects on
silicosis registers are the result of selection and diagnostic bias. Given these
difficulties, case-register studies may not be capable of giving a reliable
answer to the central question, though they have been useful in pointing to the
possibility of a can
PMID- 10689756
TI - Inhalation study on exposure to bitumen fumes. Part 1: Development and validation
of the equipment.
AB - Bitumen fumes emitted during road paving or roofing contain polycyclic aromatic
hydrocarbons (PAHs). Experimental studies have been previously performed to test
the carcinogenic potency of bitumen fumes. Some of them have been criticised
either on the grounds that the fume condensates were not representative of fumes
to which humans are exposed or because the fumes were never characterised in
terms of particle size and poorly in terms of composition and concentration in
the chambers. For a nose-only inhalation study, we have evaluated the ability of
a new fume generation system to deliver stable and reproducible atmospheres of
bitumen fumes to an inhalation chamber and investigated the representativity of
the fumes generated at a concentration level of 5 mg/m3. The fume generator
comprises: (1) an insulated 20 l heated kettle (200 degrees C for bitumen); (2)
an insulated inlet pipe with a needle valve to adjust the flow of the test
compound from the kettle; (3) a fume generation chamber equipped with a series of
interchangeable channels of different width. The fume concentration in the
exposure chamber can be controlled by changing the channel width or by
restricting the evaporation surface with aluminium foil, and/or by changing the
flow rate. Samples of the atmosphere in the chamber were collected and analysed
for quantitative determination of total particulate matter (TPM), soluble matter,
benzo[a]pyrene (B[a]P) content of the fumes and other PAHs, and evaluation of the
particle size distribution. The representativeness of the fumes has been tested
by comparison with fumes generated in the Shell small-scale fume rig, which was
previously validated against field fumes collected during paving operations.
Evaporative losses from the filters during sampling, transport and storage have
been also assessed. At 5 mg/m3 TPM, the agreement between laboratories was quite
good for the TPM analyses and was good for the soluble matter and B[a]P.
Evaporative losses may lead to underestimation of the true exposure level in the
inhalation chambers but the use of an XAD-2 cartridge backup is one approach to
partially recover losses which occur on the filter. The particle size
distributions are somewhat different from those reported for fumes associated
with roofing and indoor mastic laying works, in that we found more than 85% of
particles to be smaller than 1 micron, compared with 40% particles in the
previous analyses. In conclusion, this equipment allows reproducible generation
of fumes at the 5 mg/m3 TPM that are fairly representative of those produced in
the field with the same bitumen.
PMID- 10689758
TI - Statistical modelling of the determinants of historical exposure to bitumen and
polycyclic aromatic hydrocarbons among paving workers.
AB - INTRODUCTION: An industrial hygiene database has been constructed for the
exposure assessment in a study of cancer risk among asphalt workers. AIM: To
create models of bitumen and polycyclic aromatic hydrocarbons (PAH) exposure
intensity among paving workers. METHODS: Individual exposure measurements from
pavers (N = 1581) were collected from 8 countries. Correlation patterns between
exposure measures were examined and factors affecting exposure were identified
using statistical modelling. RESULTS: Inhalable dust appeared to be a good proxy
of bitumen fume exposure. Bitumen fume and vapour levels were not correlated.
Benzo(a)pyrene level appeared to be a good indicator of PAH exposure. All
exposures steadily declined over the last 20 years. Mastic laying, re-paving,
surface dressing, oil gravel paving and asphalt temperature were significant
determinants of bitumen exposure. Coal tar use dictated PAH exposure levels.
DISCUSSION: Bitumen fume, vapour and PAH have different determinants of exposure.
For paving workers, exposure intensity can be assessed on the basis of time
period and production characteristics.
PMID- 10689757
TI - Inhalation study on exposure to bitumen fumes. Part 2: Analytical results at two
exposure levels.
AB - During the hot application of bitumen-containing materials, e.g. in road paving
or roofing, fumes are emitted that contain traces of polycyclic aromatic
compounds (PACs). Although worker's exposure to these fumes is low, it might lead
to health problems. For studying DNA adduct formation as a consequence of
inhalation of bitumen fumes we developed and validated an inhalation system (a
dynamic fume generator plus a nose only inhalation chamber). This paper presents
and discusses the analytical results from the different laboratories involved in
this study on the fumes sampled in the inhalation chamber during three series of
experiments where the animals were exposed to fumes at the 5 mg/m3 and 50 mg/m3
level, coming from bitumen heated at 200 degrees C and, as a positive control,
fumes from coal tar, heated to 110 degrees C at the 5 mg/m3 level. The following
parameters were controlled: temperatures at different key places in the
generator; humidity of the chamber; the bitumen or coal tar flow rate; and Total
Particulate Matter (TPM). Analyses were performed for Benzene Soluble Matter
(BSM), the EPA polycyclic aromatic hydrocarbon (PAH) mixture and for a number of
heteroatom-containing PACs. The data show that the coal tar fumes produced at 110
degrees C were very volatile and that most of the differences in particulate
matter found between the laboratories can be attributed to evaporative losses.
The bitumen fumes boil 25-50 degrees C higher and contain higher boiling
compounds. A comparison is made between the PAC exposure profiles for bitumen
experiments aimed at 5 and 50 mg/m3. Although the same molecules are found in
both fumes their proportion is dramatically different. This effect is largest
with the 2- and 3-ring PACs, the ratio of the concentrations found in the 50
mg/m3 TPM concentration to that in the 5 mg/m3 experiment gradually declines from
5500 for acenaphthene to 500 for pyrene, for the 5-ring PACs this ratio is 20-30.
As function of their vapour pressure, the ratios of the concentrations of the
hetero PACs follow the same trend as that of the 16 EPA PAHs and are of the same
order of magnitude. In conclusion, for the compounds investigated, the equipment
delivers a fume atmosphere in a reproducible manner. The 50 mg/m3 bitumen fumes
are not representatives of field fumes. The reason for these quantitative
differences is unclear and further work would be needed to clarify this.
Nevertheless it was felt that these fumes at 50 mg/m3 might be a useful tool for
qualitative detection of DNA adducts in an animal exposure study.
PMID- 10689759
TI - Designing an international industrial hygiene database of exposures among workers
in the asphalt industry.
AB - OBJECTIVES: The objective of this project was to construct a database of exposure
measurements which would be used to retrospectively assess the intensity of
various exposures in an epidemiological study of cancer risk among asphalt
workers. METHODS: The database was developed as a stand-alone Microsoft Access
2.0 application, which could work in each of the national centres. Exposure data
included in the database comprised measurements of exposure levels, plus
supplementary information on production characteristics which was analogous to
that used to describe companies enrolled in the study. RESULTS AND DISCUSSION:
The database has been successfully implemented in eight countries, demonstrating
the flexibility and data security features adequate to the task. The database
allowed retrieval and consistent coding of 38 data sets of which 34 have never
been described in peer-reviewed scientific literature. We were able to collect
most of the data intended. As of February 1999 the database consisted of 2007
sets of measurements from persons or locations. The measurements appeared to be
free from any obvious bias. CONCLUSIONS: The methodology embodied in the creation
of the database can be usefully employed to develop exposure assessment tools in
epidemiological studies.
PMID- 10689761
TI - Confusion about the precision of asbestos fibres counting by electron microscopy.
PMID- 10689760
TI - In vitro and in vivo tests for determination of the pathogenicity of quartz,
diatomaceous earth, mordenite and clinoptilolite.
AB - The effects of samples of crystalline quartz, diatomaceous earth, mordenite and
clinoptilolite were investigated in vitro (as concerns erythrocyte haemolysis and
lactate dehydrogenase (LDH) release from peritoneal macrophages) and in vivo (on
LDH, protein and phospholipids in rat bronchoalveolar lavage (BAL), and
phospholipids in rat lung tissue). The respirable mineral samples were instilled
intratracheally. Determinations in the BAL were carried out after 15, 60 and 180
days, and in the lung tissue after 90, 180 and 360 days. Quartz DQ and quartz FQ
induced acute, subacute and chronic inflammation and progressive fibrosis.
However, due to the Al2O3 contamination on the surface of the particles quartz FQ
caused a delayed response in vivo. Diatomaceous earth produced acute/subacute
inflammation that gradually became more moderate after 60 days. Clinoptilolite
was inert, whereas the other zeolite sample, mordenite, was cytotoxic in vivo.
The reason for this was presumably the needle and rod-shaped particles in the
mordenite samples. The investigation revealed that different in vitro and in vivo
methods canprovide valuable data concerning the pulmonary toxicity of minerals.
PMID- 10689762
TI - An unusual case of self-treatment.
PMID- 10689763
TI - Lack of respect for practitioners alarming.
PMID- 10689764
TI - Calculating the impact of clinical governance.
PMID- 10689765
TI - Tea breaks could help calm fluoride debate.
PMID- 10689766
TI - Retention of permanent incisors by mesiodens: a family affair.
AB - The term mesiodens refers to a supernumerary tooth that is present in the midline
of the maxilla between the two central incisors. One or two mesiodentes may be
present. We present a rare case of two sisters, in both of whom a pair of
mesiodentes caused the retention of permanent incisors. They were referred to our
hospital with asymptomatic delayed eruption of upper incisors. This article is
written to point out genetic factors as the possible origin of supernumerary
teeth.
PMID- 10689767
TI - Videoconferencing: what are the benefits for dental practice?
AB - For more than 3 years members of the TeleDent team from Bristol University have
been looking at the potential of videoconferencing technology for dentistry. Here
they explain what videoconferencing is and how it can help the GDP. They discuss
examples of its most promising uses for the profession, which include
professional updating and providing diagnostic support at a distance. They
describe the equipment that is needed, the different types of system available
and give an indication of costs. A suggested procedure for using the technology
for remote referrals is outlined. 'Store and forward' techniques are also
discussed. These do not involve a live video but involve the sending of static
electronic files. This approach is compared with videoconferencing, and the
article looks at the question of which will be best suited to the GDP, and for
what purposes.
PMID- 10689768
TI - Delayed and immediate hypersensitivity reactions associated with the use of
amalgam.
AB - Hypersensitivity to the constituents of dental amalgam is uncommon. When it
occurs it typically manifests itself as a lichenoid reaction involving a delayed,
type IV, cell-mediated hypersensitivity response. Rarely, a more acute and
generalised response can occur involving both the oral mucosa and skin. We
describe two cases that illustrate the presentation and management of these two
types of reaction.
PMID- 10689769
TI - Dental care for the patient with a cleft lip and palate. Part 1: From birth to
the mixed dentition stage.
AB - This is the first of two articles looking at dental care for the patient with a
cleft lip and palate. Part 1 looks at the needs of the child with a cleft lip and
palate from birth through to the mixed dentition stage.
PMID- 10689770
TI - A study of the career development of male and female dental practitioners.
AB - AIM: The aim of the study was to determine differences between male and female
dental practitioners in the positions they occupy within their employment, and to
analyse the correlates of such differences. METHOD: Postal questionnaire survey
of a 1 in 10 sample of individuals taken from the General Dental Council
register. RESULTS: Female dental practitioners occupy lower positions in the
employment hierarchies of the Community Dental Service and the Hospital Dental
Service. Women general dental practitioners are significantly less likely to be
sole proprietor of, or a partner in, a general practice. Ownership of a general
practice is related to: sex, age, number of years qualified, number of children,
and hours worked. Consultants in the Hospital Dental Service are more likely to
be male, older, to have been qualified longer and (obviously) to hold more
additional qualifications than their non-consultant colleagues. Senior Dental
Officers and Directors of the Community Dental Service are more likely to be
male, work longer hours and (again obviously) to hold more additional
qualifications than Community Dental Officers. CONCLUSIONS: Differences exist
between male and female dental practitioners in the positions they occupy within
employment hierarchies. Age, length of time since qualification and the
acquisition of additional qualifications are consistently found to differentiate
dental practitioners' status.
PMID- 10689771
TI - Intensity of bacteraemia associated with conservative dental procedures in
children.
AB - OBJECTIVES: To explore the individual dento-gingival manipulative procedures that
together lead to the placement of a restoration and to estimate the associated
intensity of bacteraemia. PATIENTS AND METHODS: Healthy children receiving dental
treatment under general anaesthesia provided blood samples 30 seconds after one
of four dento-gingival manipulative procedures: 1. Placement of rubber dam, 2.
Use of the high speed drill, 3. Use of the slow speed drill, and 4. Placement of
matrix band and wedge. Blood cultures were processed to give the percentage
prevalence of bacteraemia, the intensity of organisms per millilitre of blood and
the identity of the organisms cultured. RESULTS: A total of 257 children were
recruited to the study. The percentage positive prevalence of blood cultures was
baseline--9.3%, rubber dam placement--31.4%, slow drill--12.2%, fast drill--4.3%,
and matrix band and wedge--32.1%. The intensity of bacteraemia was baseline--1.2
cfu, rubber dam placement--1,962 cfu, slow drill--0.3 cfu, fast drill--1.9 cfu,
matrix band and wedge--4.8 cfu. CONCLUSIONS: These data indicate that dento
gingival manipulative procedures comprising a simple dental restoration can lead
to a bacteraemia comparable to that from dental extractions. It is suggested that
these data may indicate the need for antibiotic prophylaxis for some aspects of
conservative dentistry.
PMID- 10689772
TI - Perceptions of general dental practitioners of a local secondary care service in
restorative dentistry.
AB - AIM: A major role of the hospital based secondary care service in restorative
dentistry is to accept referrals in order to formulate treatment plans. The aim
of this survey was to improve service provision at Newcastle Dental Hospital by
establishing baseline quality perceptions from referring general dental
practitioners (GDPs). METHOD: A postal questionnaire was sent to 393 randomly
selected local GDPs, with a response rate of 67%. RESULTS: Results indicated
great demand for advice and treatment which was higher than expected for
temporomandibular joint problems. 42% of GDPs felt that treatment plans were not
helpful and the period of waiting for a response following consultation too long.
The reasons for this perception are discussed. CONCLUSIONS: The need for better
communication between primary and secondary care was highlighted, as was the
distinct preference of GDPs for hospital consultants rather than registered
specialist practitioners to carry out specialist treatment.
PMID- 10689773
TI - Me gums made me do it.
PMID- 10689774
TI - Surveillance of surgical site infections.
PMID- 10689775
TI - Enhanced surveillance of neonatal group B streptococcal disease.
PMID- 10689776
TI - Mechanism of action of CpG DNA.
PMID- 10689777
TI - Oligodeoxyribonucleotides with 5'-ACGT-3' or 5'-TCGA-3' sequence induce
production of interferons.
PMID- 10689778
TI - Macrophage activation by immunostimulatory DNA.
AB - Macrophage/dendritic cells and B cells remain the only cell types where direct
responses to CpG DNA are well established. The role of macrophages in vivo in DNA
clearance and the potent cytokine induction in macrophages and dendritic cells
places them in the central role in the in vivo response to foreign DNA. Although
responses to DNA are unlikely to evolve and be retained if they are not
significant in the immune response to infection, the relative contributions of
DNA and other stimulators of the innate immune recognition of foreign organisms
is difficult to assess. Although CpG DNA and LPS have similar actions,
significant differences are emerging that make the use of DNA as a therapeutic
immunostimulatory molecule feasible. The macrophage response to DNA generates
cytokines favouring the development of Th1-type immunity, and active
oligonucleotides now show promise as Th1-promoting adjuvants and as allergy
treatments.
PMID- 10689779
TI - Consequences of bacterial CpG DNA-driven activation of antigen-presenting cells.
PMID- 10689780
TI - Signal transduction pathways activated by CpG-DNA.
AB - While more and more attention has been paid to CpG-DNA with respect to its
usefulness as an adjuvant, its molecular mechanism of action is less well
defined. Over the last few years, at least two major signalling pathways have
been shown to be utilized by CpG-DNA: the NF-kappa B activation pathway and the
stress-kinase pathway. Direct downstream events of these pathways are induction
of transcriptional activity of NF-kappa B and transcriptional activity of AP-1.
As far as investigated, CpG-DNA uses signal transduction pathways originally
described for other stimuli, such as LPS, IL-1 or TNF. Therefore, to us, the
prime question is: where does CpG-DNA-induced signalling enter these known
pathways? This raises questions about the existence of a CpG-DNA-sequence
specific receptor. Several points of evidence support the probability of the
existence of a cellular receptor: There is a strong motif (unmethylated CpG)
dependency for CpG-DNA-induced signalling. There is cell-type specificity.
Dendritic cells, macrophages and B cells respond to CpG-DNA, but other cell
types, such as fibroblasts and T cells, do not. In addition, classic signal
transduction pathways are rapidly switched on in a parallel manner, as is known
for other receptors. Using competing non-CpG ODNs and inhibitors of endosomal
acidification, some evidence has been obtained that CpG ODNs are taken up into
endosomes by a CpG-independent receptor, followed by a pH-dependent step before
signalling starts. A model based on these findings is proposed in Fig. 4.
Nevertheless, other receptor-independent activities of CpG-DNA cannot yet be
ruled out. Although unlikely, we should consider the possibility that CpG-DNA
directly interacts with cellular nucleic acids either by direct hybridization
with complementary nucleotides or by formation of DNA triplexes (VASQUEZ and
WILSON 1998). While these possibilities have been explored by antisense
technology, using a huge variety of ODNs, there is no experimental evidence that
such interactions are important for the activity of CpG-DNA. In this context, it
is important to note that DNA, especially phosphothioate-stabilized ODNs with
poly-G stretches, have substantial CpG-independent activities, although these
activities seem not to depend on specific, antisense-like DNA-DNA interactions
(PISETSKY 1996). One good example comes from experiments using ODNs on primary T
cells. Co-stimulation of CD3-primed T cells with CpG ODN leads to a significant
increase of IL-2 secretion and proliferation; however, these effects are CpG
independent (K. Heeg, personal communication). Remarkably, these poly-G stretches
seem to be inactive when transferred to double-stranded DNAs, such as plasmid DNA
(WLOCH et al. 1998). In contrast, to my knowledge, no immune-stimulatory effect
of bacterial DNA has been described that can not be abolished by CpG-specific
methylation. Taken together, CpG-dependent and CpG-independent activities must be
distinguished from one another. Among these effects, CpG-dependent signalling is
better defined. Much effort is going into the investigation of the
pharmacological applications of CpG-DNA. Once CpG-receptor-like structures are
known, the question of the physiological role of CpG-DNA can be tackled.
PMID- 10689781
TI - CpG DNA co-stimulates antigen-reactive T cells.
PMID- 10689782
TI - Role of type I interferons in T cell activation induced by CpG DNA.
PMID- 10689783
TI - Hematopoietic remodeling triggered by CpG DNA.
PMID- 10689784
TI - CpG DNA augments the immunogenicity of plasmid DNA vaccines.
PMID- 10689785
TI - The role of bacterial DNA in autoantibody induction.
AB - Bacterial DNA has potent immunological properties that can stimulate the immune
system in SLE in both specific and non-specific ways. As such, this molecule may
play an important role in disease pathogenesis, because it can exert
immunomodulatory activity and function as a molecular mimic. Future studies will
hopefully both determine the role of foreign nucleic acids in the induction of
autoantibodies and lead to strategies for their elimination.
PMID- 10689786
TI - CpG DNA in cancer immunotherapy.
PMID- 10689787
TI - Use of CpG DNA for enhancing specific immune responses.
AB - CpG ODN, owing to its wide range of immunostimulatory effects has been found to
be a potent Th1-type adjuvant that is effective with virtually any type of
antigen, although responses are less impressive with PS than protein antigens.
The use of CpG ODN as an adjuvant may allow the development of vaccines against a
wider range of diseases, which could include therapeutic vaccines for chronic
infections or cancer, effective pediatric vaccines for newborns, and easily
delivered mucosal vaccines.
PMID- 10689788
TI - Immunostimulatory-sequence DNA is an effective mucosal adjuvant.
PMID- 10689789
TI - CpG DNA switches on Th1 immunity and modulates antigen-presenting cell function.
PMID- 10689790
TI - Effects of CpG DNA on Th1/Th2 balance in asthma.
AB - Thus, in our studies, we demonstrated that CpG ODN are effective in preventing
the development of eosinophilic airway inflammation and bronchial hyper
reactivity in a murine model of asthma. Antigen-associated elevation of serum IgE
levels is also suppressed. CpG ODN, administered in conjunction with antigen, is
also effective in down-regulation of established Th2 responses. This protection
is neither murine strain-dependent nor model-dependent. Although these effects of
CpG ODN are associated with the induction of the Th1 cytokines IFN-gamma and IL
12, neither cytokine is absolutely required for the protection. These results
suggest that CpG ODN may be an effective immunomodulatory agent in the treatment,
and possibly prevention, of asthma.
PMID- 10689791
TI - Responses of human B cells to DNA and phosphorothioate oligodeoxynucleotides.
AB - Emerging information has documented that certain DNA and sODNs can be both
immunogenic and immunostimulatory. sODNs, but not DNA, induce T-cell-independent
polyclonal activation of human B cells by engaging cell-surface receptors.
Manifestations of sODN-induced human B-cell activation include expression of
activation markers, proliferation, Ig production and anti-DNA antibody
production. IL-2 and intact T cells enhanced B-cell responses to sODNs but were
not required. Monocytes also provided a modest enhancement of human B-cell
responses induced by sODNs. The chemical nature of sODNs capable of stimulating
human B cells and the specific cell-surface receptors involved have not been
completely delineated. Further studies will be necessary to elucidate the
potential role of stimulatory sODNs in disease pathogenesis and to develop a
means to employ ODNs as therapeutic agents in humans.
PMID- 10689792
TI - [Prevalence of Chlamydia infections in breeding sows and their importance in
reproductive failure].
AB - To investigate the prevalence of chlamydial infection and their significance for
reproductive disorders in sow breeding herds in Germany, blood samples of 1493
pigs were taken for a serological survey by enzyme-linked-immunosorbent-assay
(ELISA). Antibodies to Chlamydiae were found in 33% of the samples, in all herds
investigated responders could be detected. The rate of seropositive animals in
different farms varied from 4.3% to 72.7%. The percentage of positive responders
in the farms correlated positively with the occurrence of MMA-syndrome (mastitis,
metritis, agalactia), return to oestrus and diseases of the piglets. Also these
herds showed less weaned piglets per sow and litter. Comparison of seronegative
and seropositive sows within single farms revealed also worse reproductive data
for seropositive sows. A significant relationship could be found between farms
with a high quota of sero-positive sows and poor hygiene status as well as
poultry keeping. As a second step 124 cervical swabs and 9 aborted piglets were
investigated for chlamydial antigen by capture-ELISA and polymerase chain
reaction (PCR). Using the capture-ELISA for investigation only 3 probes with
chlamydial antigen could be detected, however, examination by the more sensible
PCR gave positive results in 50% of the probes. 20% of the PCR-positive animals
were clinically healthy sows, 80% of the PCR-positive probes originated from sows
with reproductive disorders. A significant relationship could be shown between
PCR-positive probes and the incidence of abortion and litters with stillborn
piglets and piglets with low viability. Swabs from 93 of the 124 sows were
investigated as well for other bacterial pathogens of reproductive disorders. A
high degree of micro-organisms of different species could be detected in 70% of
the samples of sows with reproductive disorders and in 35% of the samples of
clinically healthy sows. Species differentiation of the chlamydial antigen
positive samples was done by southern blot hybridisation. Herewith C. psittaci
could be diagnosed in all positive samples. Additionally 8 probes revealed a
mixed infection with C. psittaci and C. trachomatis. The results of the present
study show, that the prevalence of chlamydial infections in breeding herds is
high and underline the importance of chlamydial infections for reproductive
disorders. Single chlamydial infections as well as mixed infections with other
pathogens must be considered.
PMID- 10689793
TI - [Significance of respiratory compensation in acidosis in calves].
AB - The respiratory component PvCO2 of acid-base-status was observed in n = 36 calves
(age: x +/- s = 8.7 +/- 5.0 d) with neonatal diarrhea and an acidosis (venous
blood-pH: < 7.30; x +/- s = 7.08 +/- 0.15). In n = 10 (28%) calves with a severe
metabolic acidosis (pH: x +/- s = 7.03 +/- 0.12; BE: x +/- s = -22.1 +/- 5.3
mmol/l) the PvCO2 was decreased < 5.3 kPa (x +/- s = 4.5 +/- 0.5 kPa) and showed
a distinct respiratory compensation. A PvCO2 between 5.3-6.7 kPa (x +/- s = 6.0
+/- 0.4 kPa) was observed in n = 16 (44%) acidotic calves (pH: x +/- s = 7.11 +/-
0.13; BE: x +/- s = -15.2 +/- 7.4 mmol/l). These n = 26 (72%) calves showed a
simple metabolic acidosis which is well known for calves with neonatal diarrhea.
The remaining n = 10 (28%) calves showed an increase of the PvCO2 > 6.7 kPa (x +/
s = 8.0 +/- 1.5 kPa). These animals had a mixed respiratory-metabolic acidosis
(pH: x +/- s = 7.08 +/- 0.20; BE: x +/- s = -13.9 +/- 10.3 mmol/l), as the
decrease of the pH could not be determined by the decreased metabolic component
HCO3- of acid-base-status alone. Calves which died during hospitalization and
calves with a PvCO2 > 6.7 kPa tended to be younger and showed partially
significant lower values for the parameters of oxygen-supply PvO2 and SvO2.
Lactate was significantly higher in dying calves but not in calves with a mixed
acidosis which on the other hand were more dehydrated. The functional capacity of
respiratory compensation of acidotic disorders in the calves studied promised to
be almost the same as in dog and man. One reason for the failure of respiratory
compensation in some calves could be a more severe hypovolemia. With the use of
"venous hypoxemia" (decrease PvO2 and decrease SvO2) the detection of tissue
hypoxia was easier than with lactate concentration.
PMID- 10689794
TI - [Possibilities of oral iron supplementation for maintaining health status in
calves].
AB - Oral supply of 100 mg iron as bivalent cations per day effectively prevented
clinical and subclinical symptoms of anaemia in calves. Additionally, male and
female calves reached optimal growth values. The supplementation of iron to
alleviate neonatal masked anaemia ("physiological anaemia") should start on the
first day of life. This measure can be terminated at the end of the praeruminal
stage of the development, as young calves are able to take up all ferric ions
contained in the diet. The real extend of the iron deficiency of calves could not
be determined by clinical symptoms. As a practical measure it is recommended to
use the packed cell volume test.
PMID- 10689795
TI - Tissue distribution and disposition kinetics of enrofloxacin in healthy and E.
coli infected broilers.
AB - Concentrations of enrofloxacin equivalent activity were determined by
microbiological assay in the plasma of healthy and E. coli-infected broilers
following single intravenous and oral administrations at 10 mg/kg. Tissue
distribution and residue-depletion following multiple oral doses (10 mg/kg for 3
successive days) were investigated. Pharmacokinetic variables were determined
using compartmental and non-compartmental analytical methods. Plasma enrofloxacin
concentrations after intravenous dosing to healthy and infected birds were best
described by a two-compartments model. Enrofloxacin concentrations in plasma of
infected birds were lower than those of healthy ones. The disposition kinetics of
intravenously administered drug in healthy and infected birds were somewhat
different. The elimination half-life (t1/2 beta) was 4.75 vs. 3.63 h; mean
residence time (MRT) was 6.72 vs 4.90 h; apparent volume of the central
compartment (Vc) was 1.11 vs 1.57 l/kg; rate constant for transfer from
peripheral to central compartment (k21) was 1.15 vs 1.41 h-1 and total body
clearance (ClB) was 0.35 vs 0.53 l/h/kg in healthy and infected birds,
respectively. After oral administration, the absorption half-life (t1/2abs) in
the infected birds was significantly longer than in healthy birds, while
elimination half-life (t1/2el) and MRT were significantly shorter.
Bioavailability was higher in infected birds (72.50%) as compared to healthy ones
(69.78%). Enrofloxacin was detected in the tissues of healthy and infected birds
after daily oral dosing of 10 mg/kg for 3 days. It was more concentrated in
liver, kidney, and breast muscle. The minimal inhibitory concentration (MIC) of
enrofloxacin against E. coli was 0.064 microgram/ml. On the basis of maintaining
enrofloxacin plasma concentrations over the MIC, a dose of 10 mg/kg given
intravenously every 20.14 hrs or orally every 20.86 hrs should provide tissue
concentrations effective against E. coli infection in chickens.
PMID- 10689796
TI - Relationship between certain physical properties of cervical mucus and fertility
in cows.
AB - The object of the present investigation was to determine several physical
properties of cervical mucus in spontaneous oestrus cows in relation to
fertility. Because, it is very difficult to determine the exact time of the
beginning of oestrus in cows, the aim of the present study was to investigate if
physical properties of cervical mucus at the time of artificial insemination (AI)
are related to conception or not. A total of 93 cows of Friesian breed were used.
The animals exhibited spontaneous oestrus, without being submitted to any
hormonal treatment. Samples of cervical mucus were collected 5-30 min before AI
and pH, viscosity, spinnbarkeit (spinability), crystallization and penetration
were measured. Pregnancy diagnosis was performed by rectal palpation 3 months
later. The results obtained from cows that conceived (44 animals), compared to
those obtained from cows that did not conceive (49 animals), were the following:
a) viscosity had been significantly lower (p < 0.05), b) crystallization had been
significantly higher (p < 0.05), and c) pH, spinnbarkeit and penetration of
spermatozoa into cervical mucus did not differ. In conclusion, the best time for
AI is when viscosity is below 20 mm H2O and crystallization is above 3. Viscosity
and crystallization could be related to ovulation time, but this needs further
investigation.
PMID- 10689797
TI - Seroprevalence of Toxoplasma gondii antibodies among domesticated ruminants at AI
Qassim Region, Saudi Arabia.
PMID- 10689798
TI - The evolutionary genetics of adaptation: a simulation study.
AB - It is now clear that the genetic basis of adaptation does not resemble that
assumed by the infinitesimal model. Instead, adaptation often involves a modest
number of factors of large effect and a greater number of factors of smaller
effect. After reviewing relevant experimental studies, I consider recent
theoretical attempts to predict the genetic architecture of adaptation from first
principles. In particular, I review the history of work on Fisher's geometric
model of adaptation, including recent studies which suggest that adaptation
should be characterized by exponential distributions of gene effects. I also
present the results of new simulation studies that test the robustness of this
finding. I explore the effects of changes in the distribution of mutational
effects (absolute versus relative) as well as in the nature of the character
studied (total phenotypic effect versus single characters). The results show that
adaptation towards a fixed optimum is generally characterized by an exponential
effects trend.
PMID- 10689799
TI - Neutral additive genetic variance in a metapopulation.
AB - For neutral, additive quantitative characters, the amount of additive genetic
variance within and among populations is predictable from Wright's FST, the
effective population size and the mutational variance. The structure of
quantitative genetic variance in a subdivided metapopulation can be predicted
from results from coalescent theory, thereby allowing single-locus results to
predict quantitative genetic processes. The expected total amount of additive
genetic variance in a metapopulation of diploid individual is given by 2Ne sigma
m2 (1 + FST), where FST is Wright's among-population fixation index, Ne is the
eigenvalue effective size of the metapopulation, and sigma m2 is the mutational
variance. The expected additive genetic variance within populations is given by
2Ne sigma e2(1-FST), and the variance among demes is given by 4FSTNe sigma m2.
These results are general with respect to the types of population structure
involved. Furthermore, the dimensionless measure of the quantitative genetic
variance among populations, QST, is shown to be generally equal to FST for the
neutral additive model. Thus, for all population structures, a value of QST
greater than FST for neutral loci is evidence for spatially divergent evolution
by natural selection.
PMID- 10689800
TI - Clines in polygenic traits.
AB - This article outlines theoretical models of clines in additive polygenic traits,
which are maintained by stabilizing selection towards a spatially varying
optimum. Clines in the trait mean can be accurately predicted, given knowledge of
the genetic variance. However, predicting the variance is difficult, because it
depends on genetic details. Changes in genetic variance arise from changes in
allele frequency, and in linkage disequilibria. Allele frequency changes dominate
when selection is weak relative to recombination, and when there are a moderate
number of loci. With a continuum of alleles, gene flow inflates the genetic
variance in the same way as a source of mutations of small effect. The variance
can be approximated by assuming a Gaussian distribution of allelic effects; with
a sufficiently steep cline, this is accurate even when mutation and selection
alone are better described by the 'House of Cards' approximation. With just two
alleles at each locus, the phenotype changes in a similar way: the mean remains
close to the optimum, while the variance changes more slowly, and over a wider
region. However, there may be substantial cryptic divergence at the underlying
loci. With strong selection and many loci, linkage disequilibria are the main
cause of changes in genetic variance. Even for strong selection, the
infinitesimal model can be closely approximated by assuming a Gaussian
distribution of breeding values. Linkage disequilibria can generate a substantial
increase in genetic variance, which is concentrated at sharp gradients in trait
means.
PMID- 10689801
TI - Quantitative genetics in conservation biology.
AB - Most of the major genetic concerns in conservation biology, including inbreeding
depression, loss of evolutionary potential, genetic adaptation to captivity and
outbreeding depression, involve quantitative genetics. Small population size
leads to inbreeding and loss of genetic diversity and so increases extinction
risk. Captive populations of endangered species are managed to maximize the
retention of genetic diversity by minimizing kinship, with subsidiary efforts to
minimize inbreeding. There is growing evidence that genetic adaptation to
captivity is a major issue in the genetic management of captive populations of
endangered species as it reduces reproductive fitness when captive populations
are reintroduced into the wild. This problem is not currently addressed, but it
can be alleviated by deliberately fragmenting captive populations, with
occasional exchange of immigrants to avoid excessive inbreeding. The extent and
importance of outbreeding depression is a matter of controversy. Currently, an
extremely cautious approach is taken to mixing populations. However, this cannot
continue if fragmented populations are to be adequately managed to minimize
extinctions. Most genetic management recommendations for endangered species arise
directly, or indirectly, from quantitative genetic considerations.
PMID- 10689802
TI - Estimating genetic correlations in natural populations.
AB - Information on the genetic correlation between traits provides fundamental
insight into the constraints on the evolutionary process. Estimates of such
correlations are conventionally obtained by raising individuals of known
relatedness in artificial environments. However, many species are not readily
amenable to controlled breeding programmes, and considerable uncertainty exists
over the extent to which estimates derived under benign laboratory conditions
reflect the properties of populations in natural settings. Here, non-invasive
methods that allow the estimation of genetic correlations from phenotypic
measurements derived from individuals of unknown relatedness are introduced. Like
the conventional approach, these methods demand large sample sizes in order to
yield reasonably precise estimates, and special precautions need to be taken to
eliminate bias from shared environmental effects. Provided the sample consists of
at least 20% or so relatives, informative estimates of the genetic correlation
are obtainable with sample sizes of several hundred individuals, particularly if
supplemental information on relatedness is available from polymorphic molecular
markers.
PMID- 10689803
TI - Artificial selection on phenotypically plastic traits.
AB - Many phenotypes respond physiologically or developmentally to continuously
distributed environmental variables such as temperature and nutritional quality.
Information about phenotypic plasticity can be used to improve the efficiency of
artificial selection. Here we show that the quantitative genetic theory for
'infinite-dimensional' traits such as reaction norms provides a natural framework
to accomplish this goal. It is expected to improve selection responses by making
more efficient use of information about environmental effects than do
conventional methods. The approach is illustrated by deriving an index for mass
selection of a phenotypically plastic trait. We suggest that the same approach
could be extended directly to more general and efficient breeding schemes, such
as those based on general best linear unbiased prediction. Methods for estimating
genetic covariance functions are reviewed.
PMID- 10689804
TI - A classical setting for associations between markers and loci affecting
quantitative traits.
AB - We examine the relationships between a genetic marker and a locus affecting a
quantitative trait by decomposing the genetic effects of the marker locus into
additive and dominance effects under a classical genetic model. We discuss the
structure of the associations between the marker and the trait locus, paying
attention to non-random union of gametes, multiple alleles at the marker and
trait loci, and non-additivity of allelic effects at the trait locus. We consider
that this greater-than-usual level of generality leads to additional insights, in
a way reminiscent of Cockerham's decomposition of genetic variance into five
terms: three terms in addition to the usual additive and dominance terms. Using
our framework, we examine several common tests of association between a marker
and a trait.
PMID- 10689805
TI - Estimating the genetic architecture of quantitative traits.
AB - Understanding and estimating the structure and parameters associated with the
genetic architecture of quantitative traits is a major research focus in
quantitative genetics. With the availability of a well-saturated genetic map of
molecular markers, it is possible to identify a major part of the structure of
the genetic architecture of quantitative traits and to estimate the associated
parameters. Multiple interval mapping, which was recently proposed for
simultaneously mapping multiple quantitative trait loci (QTL), is well suited to
the identification and estimation of the genetic architecture parameters,
including the number, genomic positions, effects and interactions of significant
QTL and their contribution to the genetic variance. With multiple traits and
multiple environments involved in a QTL mapping experiment, pleiotropic effects
and QTL by environment interactions can also be estimated. We review the method
and discuss issues associated with multiple interval mapping, such as likelihood
analysis, model selection, stopping rules and parameter estimation. The potential
power and advantages of the method for mapping multiple QTL and estimating the
genetic architecture are discussed. We also point out potential problems and
difficulties in resolving the details of the genetic architecture as well as
other areas that require further investigation. One application of the analysis
is to improve genome-wide marker-assisted selection, particularly when the
information about epistasis is used for selection with mating.
PMID- 10689806
TI - Linkage disequilibrium mapping of molecular polymorphisms at the scabrous locus
associated with naturally occurring variation in bristle number in Drosophila
melanogaster.
AB - We evaluated the hypothesis that the Drosophila melanogaster second chromosome
gene scabrous (sca), a candidate sensory bristle number quantitative trait locus
(QTL), contributes to naturally occurring variation in bristle number. Variation
in abdominal and sternopleural bristle number was quantified for wild-derived sca
alleles in seven genetic backgrounds: as homozygous second chromosomes (C2) in an
isogenic background, homozygous lines in which approximately 20 cM including the
sca locus had been introgressed into the isogenic background (sca BC), as C2 and
sca BC heterozygotes and hemizygotes against a P element insertional sca allele
and a P-induced sca deficiency in the same isogenic background, and as sca BC
heterozygotes against the wild-type sca allele of isogenic strain. Molecular
restriction map variation was determined for a 45 kb region including the sca
locus, and single-stranded conformational polymorphism (SSCP) was examined for
the third intron and parts of the third and fourth exons. Associations between
each of the 27 molecular polymorphisms and bristle number were evaluated within
each genotype and on the first principal component score determined from all
seven genotypes, separately for each sex and bristle trait. Permutation tests
were used to assess the empirical significance thresholds, accounting for
multiple, correlated tests, and correlated markers. Three sites in regulatory
regions were associated with female-specific variation in abdominal bristle
number, one of which was an SSCP site in the region of the gene associated with
regulation of sca in embryonic abdominal segments.
PMID- 10689807
TI - Mapping quantitative trait loci for murine growth: a closer look at genetic
architecture.
AB - Over 20 years ago, D. S. Falconer and others launched an important avenue of
research into the quantitative of body size growth in mice. This study continues
in that tradition by locating quantitative trait loci (QTLs) responsible for
murine growth, such as age-specific weights and growth periods, and examining the
genetic architecture for body weight. We identified a large number of potential
QTLs in an earlier F2 intercross (Intercross I) of the SM/J and LG/J inbred mouse
strains. Many of these QTLs are replicated in a second F2 intercross (Intercross
II) between the same two strains. These replicated regions provide candidate
regions for future fine-mapping studies. We also examined body size and growth
QTLs using the combined data set from these two intercrosses, resulting in 96
microsatellite markers being scored for 1045 individuals. An examination of the
genetic architecture for age-specific weight and growth periods resulted in
locating 20 separate QTLs, which were mainly additive in nature, although
dominance was found to affect early growth and body size. QTLs affecting early
and late growth were generally distinct, mapping to separate chromosome
locations. This QTL pattern indicates largely separate genetic and physiological
systems for early and later murine growth, as Falconer suggested. We also found
sex-specific QTLs for body size with implications for the evolution of sexual
dimorphism.
PMID- 10689808
TI - Testing the correspondence between map positions of quantitative trait loci.
AB - There are several instances in which quantitative trait locus (QTL) mapping
experiments have been independently carried out for similar traits in different
laboratories. We develop a permutation test of the correspondence between the
test statistics obtained from genome-wide QTL scans in two such experiments to
test whether the same QTLs are segregating in the experimental pair. In
simulations, we show that the permutation test has the desired properties if
chromosomes are of equal length, but bias can occur if chromosomes are of unequal
length, a problem connected with autocorrelation of test statistic values. We
apply the test to data from three recent mouse body weight QTL mapping
experiments. The results from the test are non-significant, and imply a lack of
overall concordance between the QTLs that were segregating in these experiments.
PMID- 10689809
TI - The genetic basis of inbreeding depression.
AB - Data on the effects of inbreeding on fitness components are reviewed in the light
of population genetic models of the possible genetic causes of inbreeding
depression. Deleterious mutations probably play a major role in causing
inbreeding depression. Putting together the different kinds of quantitative
genetic data, it is difficult to account for the very large effects of inbreeding
on fitness in Drosophila and outcrossing plants without a significant
contribution from variability maintained by selection. Overdominant effects of
alleles on fitness components seem not to be important in most cases. Recessive
or partially recessive deleterious effects of alleles, some maintained by
mutation pressure and some by balancing selection, thus seem to be the most
important source of inbreeding depression. Possible experimental approaches to
resolving outstanding questions are discussed.
PMID- 10689810
TI - Properties of spontaneous mutations affecting quantitative traits.
AB - Recent mutation accumulation results from invertebrate species suggest that mild
deleterious mutation is far less frequent than previously thought, implying
smaller expressed mutational loads. Although the rate (lambda) and effect (s) of
very slight deleterious mutation remain unknown, most mutational fitness decline
would come from moderately deleterious mutation (s approximately 0.2, lambda
approximately 0.03), and this situation would not qualitatively change in harsh
environments. Estimates of the average coefficient of dominance (h) of non-severe
deleterious mutations are controversial. The typical value of h = 0.4 can be
questioned, and a lower estimate (about 0.1) is suggested. Estimated mutational
parameters are remarkably alike for morphological and fitness component traits
(excluding lethals), indicating low mutation rates and moderate mutational
effects, with a distribution generally showing strong negative asymmetry and
little leptokurtosis. New mutations showed considerable genotype-environment
interaction. However, the mutational variance of fitness-component traits due to
non-severe detrimental mutations did not increase with environmental harshness.
For morphological traits, a class of predominantly additive mutations with no
detectable effect on fitness and relatively small effect on the trait was
identified. This should be close to that responsible for standing variation in
natural populations.
PMID- 10689811
TI - Role of growth hormone in the genetic change of mice divergently selected for
body weight and fatness.
AB - To elucidate the involvement of growth hormone (GH) in the genetic change
produced by long-term selection in growth and fatness, a 'GH knock-out study' on
over 900 mice was undertaken. Lines used had been selected for more than 50
generations for high (PH) and low (PL) body weight (initially protein mass) at 70
d(ays) and for high (F) and low fat content (L) at 98 d, producing a 3-fold
difference in body weight and a 5-fold difference in fat content. GH deficiency
was achieved by repeated backcrossing into each line a recessive mutant gene
(lit) which has a defective GH releasing factor receptor. In the absence of GH,
the P lines still differ in body weight (21 d to 98 d): e.g. at 98 d homozygous
lit/lit: PH = 24.2 g, PL = 10.0 g; wild-type (wt): PH = 57.4 g, PL = 18.7 g. The
effect of the GH deficiency on body weight (untransformed) was very much larger
in the PH than in the PL line, but the interaction was much smaller, although
still significant, on the log scale. This indicates that changes in the GH system
contribute only a small part of the selection response in growth. GH deficiency
increased fat percentage in all lines (including P), especially in males (99 d,
males lit/lit: F = 26.4%, L = 6.9%; wt: F = 22.0%, L = 4.8%; females: 20.2%,
5.2%, 20.7%, 3.0%) with significant genotype x line and genotype x sex
interactions. The interactions between the effects of the lit gene and the
genetic background were, however, relatively small compared with these main
effects and again indicate that other systems contributed most of the selection
response.
PMID- 10689812
TI - [BCG vaccination in the world].
AB - BCG vaccination programme and BCG vaccination coverage in the world were
summarized mainly based on the published informations from official
organizations, such as World Health Organization (WHO), International Union
Against Tuberculosis and Lung Disease (IUATLD) and Centers for Disease Control
and Prevention (CDC). From this review, we can see how widely BCG has been used
for the prevention of tuberculosis in the world. In most of the developing
countries, especially in Africa, the Americas, and Pacific Region, BCG
vaccination is carried out to newborn babies soon after birth by intradermal
injection according to the recommendations from WHO, but some of the developing
countries in Asia and Europe have their own modified BCG vaccination programmes.
In economically developed countries, BCG vaccination programme has been
established according to the tuberculosis status of each countries. Some
countries have general vaccination policy, and other countries have selected
vaccination policy, but there is no country where BCG vaccination is not carried
out at all. Among G8 contries, as representatives of the economically developed
countries, Japan, United Kingdom, France and Russian Federation have BCG general
vaccination policy for the specified age group. In these 4 countries
revaccination (s) of BCG are still carried out. In Germany, some provinces have
general vaccination policy and some others have selected vaccination policy. In
the United States of America, BCG vaccination is recommended to selected high
risk infants and health care workers by CDC. There are many debates as for the
efficacy and safety of BCG vaccination, and the development of new vaccine better
than BCG has been actively discussed and some encouraging results in animal
models have been reported from several laboratories. But, there is almost no
possibility to be able to use a new vaccine in the routine practice within a
couple of years. From the practical point of view, therefore, the operational
researches for the better and more appropriate usage of BCG are equally important
and more practical than the researches for the development of new vaccines.
PMID- 10689813
TI - [Effect of serotype specific glycopeptidolipid (GPL) isolated from Mycobacterium
avium complex (MAC) on phagocytosis and phagosome-lysosome fusion of human
peripheral blood monocytes].
AB - Mycobacterium avium complex (MAC) is a typical intracellular parasite similar to
M. tuberculosis and is one of the most important pathogens that coinfects AIDS
patients. Attention has been focused on M. avium infection causing
immunosuppression of hosts. Specific serotype-subspecies such as 1, -4 or -8
serotypes can be isolated frequently in humans infected with HIV. Furthermore,
the prognosis after infection differs depending on the serotype. Serotype-4 in
general shows unfavourable prognosis, while serotype-16 yields rapid recovery.
Therefore, we have been interested in the immunomodifying activity of the surface
glycopeptidolipid (GPL) antigen. However, no information has been available to
date dealing on the virulent factor of MAC that is directly related with
intracellular bactericidal activity. Recently, we have tried to test the effect
of various GPLs purified from MAC on phagocytic processes of human peripheral
blood monocytes (PBMC). We have used GPL-coated heat-killed staphylococcal cells
to be phagocytosed by PBMC, and phagosome-lysosome fusion (P-L fusion) was
estimated by the acridine orange staining of fused vesicles and bacteria. Results
showed strong promotion of phagocytosis and marked inhibition of P-L fusion by
serotype-4 GPL, while neither promotion of phagocytosis nor inhibition of P-L
fusion in phagocytic cells were shown by serotype-16 GPL. Serotype-8 GPL showed
concomitant stimulation of both phagocytosis and P-L fusion. These effects may be
due to some unknown interaction between specific carbohydrate chain and organella
membranes and serotype-4 GPL may be one of the possible virulent factors in MAC.
Comparison with known possible virulent factors such as trehalose 6,6'-dimycolate
(TDM), trehalose 6-monomycolate (TMM), glucose 6-monomycolate (GM) or sulfatide
was also reported.
PMID- 10689814
TI - [Isolation of Mycobacterium avium complex from the "24-hour bath"].
AB - The "24-HOUR BATH" is an apparatus which circulates the bath water, keeps it
clean and warm, and makes it possible to take a bath at any time during the day
or night. It consists of apparatus for cleaning (sponge or mesh filter and filter
material), heating (ceramic heater), and sterilizing (UV lamp). Recently, three
cases of skin disease due to M. avium infection in private homes, in which "24
HOUR BATH" water was suspected to be the source of infection, have been reported.
We attempted to isolate M. avium complex from the water (32 specimens), sponge
filter (29 specimens), and filter material (32 specimens) of the "24-HOUR BATH".
One hundred-ml samples of bath water, and 50-ml samples of rinse from a sponge
filter or filter material were centrifuged at 3000 rpm for 20 min. Sediment was
suspended in distilled water and a smear was prepared, and then digested and
decontaminated with 2% sodium hydroxide. The processed specimens were cultured on
2% Ogawa medium containing ofloxacin (1 microgram/ml) and ethambutol (2.5
micrograms/ml) for 8 weeks at 37 degrees C. Positive smears were 3 (9.4%), 25
(86.2%) and 25 (78.1%) specimens from the water, sponge and filter material,
respectively. A few bacterial clumps were observed, especially in the sponge
specimens. The number of positive culture was 5 (15.6%), 24 (82.8%) and 25
(78.1%) from the water, sponge and filter material, respectively. Among them the
number of Runyon's Group III-positive cultures was 5 (100%), 22 (91.7%) and 20
(80%) in the water, sponge, and filter material specimens, respectively. In most
cases, cultures were positive for both the sponge and filter material specimens.
All of the Group III mycobacteria were smooth, grew at 28, 37, 42, and 45 degrees
C, negative for niacin, nitrate reductase, semiquantitative catalase, urease and
Tween80 hydrolysis, and positive for 68 degrees C catalase. All of the strains
reacted with M. avium complex AccuProbe and M. avium AccuProbe, but none of the
strains reacted with M. intracellulare AccuProbe. Therefore, all the Group III
isolates were identified as M. avium by the culture, biochemical and genetical
characteristics.
PMID- 10689815
TI - [Two-step tuberculin skin test in nurse students and hospital employees].
AB - Booster phenomenon (recall effect) of tuberculin skin test, which disturbs
diagnosis of tuberculous infection, is prevalent among BCG vaccinated population.
We retested 34 nurse students whose initial tuberculin reaction was smaller than
30 mm by erythema (Group A) and 53 hospital employees whose initial reaction was
smaller than 20 mm by erythema (Group B). Among the people whose diameter of
erythema was less than 10 mm by the first test, 88 percent (8/9) of group A and
43% (6/14) of group B showed reaction 10 mm < or = by erythema and among those
whose induration was < 10 mm, 54% (6/11) of group A and 48% (12/25) of group B
showed reaction 10 mm < or = in the second testing. Mean and standard deviation
of [the difference between the diameter of the 2nd and the 1st testing] was +7.3
+/- 11.8 mm in group A, +9.8 +/- 11.1 mm in group B by erythema and +2.6 +/- 5.9
mm in group A, +2.9 +/- 5.1 mm in group B by induration. These results indicate
that booster phenomenon is highly prevalent among the tested group and there can
be no appropriate criteria to distinguish new infection and booster phenomenon.
Though two-step tuberculin skin test is recommended to get rid of booster
phenomenon. Only a little is known about the value of this test to diagnose new
infection in Japanese population, majority of whom being BCG vaccinated. Further
investigations are required to apply two-step tuberculin skin test for diagnosis
of new infection among hospital employees and health care workers in Japan.
PMID- 10689816
TI - [A case of pulmonary tuberculosis complicated with subcutaneous
phaeohyphomycosis].
AB - A 78-year-old male was admitted to our hospital because of fever, sputum and
cough. Chest X-ray showed infiltrative shadows in the right lung field. Smears of
his sputum were positive for acid-fast bacilli. We found multiple subcutaneous
abscesses on the right distal forearm. Microscopic examination of skin biopsy
specimens revealed granulation tissues with the proliferation of epitheloid cells
with the scattering infiltrations of neurophils, giant cells and histiocytic
cells. The examination of the PAS stained specimen revealed fungal elements and a
black fungus, Exophiala jeanselmei, was isolated by the cultures of pus from the
abscess. He was diagnosed as pulmonary tuberculosis complicated with subcutaneous
phaeohyphomycosis caused by Exophiala jeanselmei and was successfully treated
with anti-tuberculosis drugs and anti-fungal agent, 5-fluorocytosine.
PMID- 10689817
TI - [Endoscopic approach to pulmonary diseases: Transbronchial needle aspiration].
AB - Transbronchial needle aspiration (TBNA) is a bronchoscopic technique to obtain
cytologic and histologic specimen from deep site of bronchial wall. We
investigated the utility and safety of TBNA in 200 patients who had mass lesions
in the lung or in the mediastinum. 101 patients had submucosal or peribronchial
malignant lesions (central malignancy) and TBNA was the only diagnostic method in
28 patients (28%). 39 patients had peripheral malignant lesions (peripheral
malignancy) and TBNA was the only diagnostic method in 12 patients (31%). The
other 60 patients had benign lesions and TBNA was diagnostic in only 5 patients
(8%); bronchogenic cyst in 2, tuberculous lymph adenitis in 1, parathyroid
adenoma in 1 and lung abscess in 1. In central malignancy, the yield of TBNA as
exclusive means of diagnosis was higher for mediastinal tumor than for lung
cancer. In peripheral malignancy it was higher for metastatic lung tumor than for
primary lung tumor. In order to stage patients of lung cancer, we sampled 39
lymph nodes and 21 of them were proved to be positive. TBNA was thought to be of
greatest value in the diagnosis of peritracheal mediastinal tumor and
peribronchial metastatic lung tumor and in the staging of lung cancer. We used 19
gauge transbronchial histology needle in 8 patients and 2 cases were diagnostic.
Low diagnostic yields were probably due to the lack of our experience and it was
expected that training on this technique would increase diagnostic utility of the
histology needle. No significant complications occurred and all patients
tolerated TBNA well.
PMID- 10689818
TI - [Endoscopic approach to pulmonary diseases: Bronchoscopy for critical respiratory
care in neonates, infants, and children].
AB - Of the 605 pediatric patients admitted to our intensive care unit during the past
6 years, 90 underwent 380 bronchoscopies for diagnostic and therapeutic purposes.
The indications for bronchoscopy were atelectasis/retention of airway secretion
(n = 52), pneumonia (n = 31), airway bleeding (n = 14), pulmonary edema (n = 11),
tracheobronchomalacia/airway stenosis (n = 11), and airway foreign
body/aspiration (n = 7). Visualization of the airway was helpful for the
diagnosis of respiratory problems; in 9 infants, bronchoscopy revealed
tracheobronchial stenosis which other diagnostic modalities failed to detect. In
25 of the 31 patients with pneumonia, specimens taken by bronchoscopy were
positive for specific pathogens. Bronchoscopy also proved to have significant
therapeutic value, especially for airway cleaning; bronchial suctioning resulted
in immediate reexpansion of the collapsed lung in 25 of 34 cases of physiotherapy
resistant atelectasis. A rigid bronchoscope was used to remove airway foreign
body in 2 cases. Prototype channeled-ultrathin fiberscopes were utilized in 99 of
380 bronchoscopies. No complications were noted except for severe hypoxia and
bradycardia in one infant. We conclude that bronchoscopy is a safe and useful
modality for the critical respiratory care of infants and children.
PMID- 10689819
TI - [Endoscopic approach to pulmonary diseases: Clinical utility of medical
thoracoscopy in diagnosis of pleural diseases].
AB - Thoracoscopy is useful for diagnosis of a number of lung diseases. We report our
recent experience of medical thoracoscopy performed under local anesthesia in 142
cases. Of 124 patients with pleural effusion, 46 had pleuritis carcinomatosa, 11
had pleuritis tuberculosa, and 10 had malignant mesothelioma. We evaluated the
utility of thoracoscopic observation and pleural biopsy in these three diseases.
Almost of patients with malignant pleural effusion initially undiagnosed by the
cytology of pleural effusion were diagnosed by thoracoscopy. Especially in
malignant mesothelioma, thoracoscopy allowed accurate diagnosis. No serious
complication was observed. Since medical thoracoscopy under local anesthesia is a
rapid, easy, safe, and well-tolerated procedure with an excellent diagnostic
yield, it is recommended as a diagnostic procedure for cases with pleural
effusion.
PMID- 10689820
TI - [Endoscopic approach to pulmonary diseases: Usefulness of the mediastinoscopy].
AB - The purposes of this study are to show the diagnostic values and the role of the
mediastinoscopy for the respiratory diseases. From 1971 to 1998, mediastinoscopy
were performed on 1664 patients admitted to our hospital with respiratory
diseases. For the superior mediastinal diseases, mediastinal tumor and
lymphadenopathies without cancer, two or three samples were obtained by
mediastinoscopy. For lung cancer, biopsy was routinely performed at the 6 nodal
stations, right and left paratracheal (#2), right and left tracheobronchial (#4),
pretracheal (#3), and subcarinal (#7) lymphnodes. From 1994, we have used video
mediastinoscopy, which was combined with scope and TV-camera. Using video
mediastinoscopy, many staffs could observe the mediastinal findings on TV-monitor
during mediastinal manipulation. The positive findings were observed in 17%
(221/1299) for lung cancer, 100% (32/32) for sarcoidosis, 100% (2/2) for
malignant lymphoma, 65% (11/17) for mediastinal tumor, 9.8% (13/132) for
pulmonary tuberculosis. The positive rate according to the histological types of
lung cancer were 20.5% (148/721) for adenocarcinoma, 9.4% (39/415) for squamous
cell carcinoma, 31.6% (24/76) for small cell carcinoma, 21.3% (10/47) for large
cell carcinoma. Complications developed in a total of 3.6%, and these were
bronchial arterial damage(1.8%), recurrent nerve paralysis(0.7%), azygos vein
damage (0.4%), pleural rupture(0.4%), superior vena cava damage(0.2%) and
tracheal laceration(0.1%). However, there were no severe complications and
operative deaths in this series. Mediastinoscopy is a minimal invasive and safety
surgical procedure that is widely used as a diagnostic method for investigating
the superior mediastinum, mediastinal tumor and lymphadenopathies. It is useful
for obtaining histological diagnosis, as well as for staging lung cancer. Video
mediastinoscopy is more safety and educational, because many staffs could observe
the findings.
PMID- 10689821
TI - Leprosy elimination campaigns (LEC).
PMID- 10689822
TI - Guidelines for carrying out leprosy elimination campaigns 1996. WHO, Action
Programme for the Elimination of Leprosy.
AB - A Leprosy Elimination Campaign (LEC) is an initiative which aims to detect
leprosy cases, particularly the more serious ones referred to as 'cases of
consequence', that remain undetected in the community, and to treat them with
MDT. This will subsequently reduce the delay in managing such cases in the
community and ensure that the existing health services are able to treat them. It
is a time-bound, one-time activity. Leprosy of consequence is defined as cases
with more than five skin lesions and skin smear positive cases. Such cases are
regarded as being of consequence because they act as a major source of infection
in the community and are either already disabled or at high risk of becoming
disabled. LEC is a focused combination of activities which includes: orientation
courses for local health workers and volunteers; community awareness creation
activities; case-finding and treating every detected case immediately with MDT.
These campaigns are to be carried out primarily in endemic regions where the
prevalence and new case detections are high and where the gap between estimated
and registered cases is large. It is a national activity, implemented by the
national staff with technical cooperation from WHO and other agencies.
PMID- 10689823
TI - Leprosy elimination--sprint or marathon?
PMID- 10689824
TI - Progress towards elimination of leprosy as a public health problem in India and
role of modified leprosy elimination campaign.
AB - India (population 943 million) has seen a highly significant decrease in the
prevalence of leprosy since the introduction of multi-drug therapy (MDT) in 1981.
From a prevalence rate of 57/10,000 of the population in March 1981, the figure
has declined to 5.2/10,000 in March 1999. This was possible due to the creation
of a completely vertical (specialized) infrastructure for leprosy control in the
218 endemic districts of the country and skeleton vertical staff in the remaining
districts, coupled with the recruitment of additional staff on contract basis to
provide MDT through vertical staff in endemic districts and mobile treatment
units in the moderate and low endemic districts. Despite all efforts, however,
new case detection has not shown a decline over the last 14 years due to the
presence of hidden (and undiagnosed) cases. Therefore, in order to intensify and
hasten progress towards elimination (less than 1 case per 10,000 of the
population) in the whole country, it was decided to implement a massive leprosy
elimination campaign (LEC) in all the States/Union Territories (UTs). The reports
of 22 States/UTs indicate that 415 out of the total of 490 districts in the
country were covered by modified LEC (MLEC), with 85% coverage of the population.
The campaign used in India was modified from the pattern previously described by
the World Health Organization. The detection of hidden or suspected cases took
place within a short, intensive period of 6-7 days and relied heavily on house-to
house searches by General Health Care staff trained in leprosy detection and
confirmation was made by appropriately trained staff. This MLEC received
widespread Government and public support, resulting in the detection of 454,290
hidden cases of leprosy, whilst providing training to a large number of General
Health Care staff and volunteers and creating widespread awareness about leprosy
and the availability of treatment free of charge for all cases. This programme
proved to be one of the most successful health care interventions undertaken in
India in recent years, particularly in the states of Bihar and Orissa. Although a
few states in India are unlikely to reach the current WHO goal of elimination
before end of the year 2000, the results of the MLEC strongly support the
possibility that elimination levels will be achieved in the majority of states by
the end of the year 2000 and at national level by the end of the year 2002.
PMID- 10689825
TI - Modified leprosy elimination campaign (MLEC) in the State of Orissa, India.
AB - As part of a country-wide modified leprosy elimination campaign (MLEC) carried
out in 21 selected States in India in 1998, the State of Orissa launched
activities in early January of that year, during which 28.9 million people were
examined, giving 85% coverage of the enumerated population. Using general health
care staff and volunteers, 416,604 suspect cases were identified and 62,804 of
these were confirmed as leprosy by experience observers. The period of intensive
search activity lasted 1 week only, but this was preceded by several months of
community mobilization and involvement, health education, training of government
and voluntary staff, media messages and the involvement of all relevant health
departments, officials and politicians. Both this and the intensive search period
were characterized by a high level of interest and cooperation by all concerned.
The total of new cases detected and put on treatment (multi-drug therapy; MDT)
during the period of only 7 days was approximately equal to that which, on
routine population survey by the leprosy services, would be recorded over a
period of 2 years. The MLEC in Orissa is judged to have been not only an historic
step forward in the control of leprosy in a State previously classified as highly
endemic for leprosy, but also one of the most successful State health
interventions ever mounted. In the 5 months after completion of the campaign, the
voluntary reporting rate increased from 50 to 90%. As a direct result of the
campaign, facilities for the diagnosis and treatment of leprosy are now available
daily in an additional 1639 institutions, over and above those in existence
before the campaign was launched. The achievements in terms of detecting hidden
(and thus undiagnosed and untreated) cases exceeded the outset predictions,
underlining the importance of continued vigilance and the need to maintain
involvement of general health care staff. It is anticipated that the rise in
prevalence due to the addition of 62,884 cases will be reduced by the
implementation of MDT by 80% by about March 1999. Overall the results of the MLEC
in Orissa strongly support the likelihood that an elimination level of less than
1 case per 10,000 of the population will be reached in this State by the year
2000.
PMID- 10689826
TI - Leprosy elimination campaign in a metropolitan leprosy project, Bombay, India.
PMID- 10689827
TI - Pace of leprosy elimination and support teams in Bihar state, India.
AB - Despite the extensive implementation of multiple drug therapy (MDT) in most
leprosy-endemic countries world-wide since 1982, bringing about a remarkable
reduction in prevalence, there are still regions at the sub-national level where
the implementation of MDT remains difficult. The state of Bihar (population 86.3
million) in India is a good example of such a region. Previously rated as one of
the most highly endemic states, it still contributes about 21% of the total
caseload in India and about 12% of the global caseload. For various reasons, case
finding and drug treatment have lagged behind the progress made in most other
states in the country and in 1996, the Damien Foundation India Trust (DFIT)
volunteered technical support to increase the pace of elimination. Sixteen out of
the 39 districts in the state were allocated, with a population of 41.8 million.
Support teams, including a Medical Advisor and a Non-Medical Supervisor, both
with over 10 years experience of leprosy work and control programmes, were
provided to assist and work alongside government staff in case detection,
treatment delivery, case-holding and discharge in their respective areas of
operation. New case detection by intensive survey increased by 394% and total new
case detection by 226% during the year 1996-1997, with similar trends in the
following year. Striking improvements were also observed in MDT coverage,
treatment regularity, monitoring and discharge of patients and in the training of
local staff. This collaboration between a non-government agency (DFIT) and the
staff of the National Leprosy Eradication Programme in 16 out of 39 districts in
the State of Bihar has clearly been extremely successful. Similar approaches in
the remaining districts of Bihar, and in other parts of India, where the
infrastructure is available but inadequate, may contribute significantly to
achieving the elimination goal at national and sub-national levels.
PMID- 10689828
TI - Modified leprosy elimination campaign in Mumbai (Bombay), India--a report.
AB - With appropriate planning and preparation, a modified leprosy elimination
campaign (MLEC) was undertaken in Brihan Mumbai (Bombay), which has a population
of around 11 million. For the campaign, 4879 non-leprosy paramedical and non
medical personnel were trained and utilized as searchers. The MLEC revealed 1410
new leprosy cases, with a new case detection rate of 1.83/10,000. Over 80% of all
cases detected were either single-lesion or paucibacillary (PB), and thus of
limited significance with regard to transmission. Further efforts are required to
detect and treat cases of consequence (those with more than five lesions and
those with positive skin smears) and to identify reservoirs of infection.
PMID- 10689829
TI - Leprosy elimination campaigns: the Nigerian experience.
PMID- 10689830
TI - Report of the national leprosy elimination campaign (NLEC) of Bangladesh, 1999.
AB - A national leprosy elimination campaign (NLEC) was implemented country-wide in
all the 64 districts of Bangladesh for 6 days from 7 to 12 February 1999. The
campaign was jointly funded by the Government of Bangladesh (GOB)/World Bank
(US$250,000) and the remaining US$381,000 was provided by other international non
governmental organizations (NGOs). A total of 44,400 health workers and community
volunteers were directly involved in the campaign. In all, 60,878 suspected
leprosy cases were identified during the campaign, of whom 31,433 were examined
and 2435 were confirmed as leprosy cases. The remaining suspects are expected to
be examined within the next 2 months. Details of the new cases detected are given
in Table 8. The impact of NLEC has been significant, the number of cases detected
during NLEC being 20% of the annual case detection in 1998. About 52% of the
total population were directly contacted through a rapid house-to-house survey
and over 90% of the population was targeted through extensive use of
electronic/print media and various information, education and communication (IEC)
activities.
PMID- 10689831
TI - Leprosy elimination campaign (LEC) in Myanmar, 1997 to May 1999.
PMID- 10689832
TI - Leprosy elimination campaign (LEC) in the Philippines.
PMID- 10689833
TI - The Dharavi story--saga of LECs over 2 decades.
PMID- 10689834
TI - Future scope and expectations: why, when, and how LECs should continue.
AB - There is a strong case to continue to use LEC approaches, as they are a
comprehensive and cost effective means of delivering the key elements of leprosy
control. LECs should be conducted when there is evidence of large numbers of
hidden cases. Probably a minimum of two LECs is required but where large number
of new cases continue to be detected they could be run on an annual basis. The
methodology of LECs needs to be improved through experience, evaluation and from
LECs conducted elsewhere; feedback from the community is also important. There is
room to improve all aspects of LECs: planning, training, education, diagnosis and
treatment completion.
PMID- 10689835
TI - [Propofol potentiates the neuromuscular blocking effects of vecuronium in man].
AB - The possible interaction between vecuronium and propofol has been investigated in
40 healthy (ASA I-II) patients. They were randomly allocated to two groups
according to the method of anesthesia; continuous propofol infusion group
(propofol) and droperidol and fentanyl group (control). The electromyographic
response of abductor digiti minimi was monitored at 20-s interval after train-of
four stimulations of the ulnar nerve. The ED50 and ED95 (dose required to produce
a 50% and 95% depression of twitch tension, respectively,) of vecuronium in the
propofol group (n = 20) were 29.4 +/- 0.5 and 56.6 +/- 2.1 micrograms.kg-1 (mean
+/- SEM), and in the control group (n = 20), 36.7 +/- 1.8 and 73.6 +/- 5.2
micrograms.kg-1, respectively. Under propofol anesthesia, the cumulative dose
response curves of vecuronium were shifted to the left when compared with control
ED50 and the slope showed that propofol had potentiated the action of vecuronium.
PMID- 10689836
TI - [Lack of communication between anesthesiologists and surgeons: comparison of
questionnaire survey among anesthesiologists with that among surgeons concerning
pre-anesthetic evaluation of surgical patients].
AB - We conducted a survey to examine surgeons' opinions and criticisms of patient
evaluations done by anesthesiologists prior to surgery. We sent questionnaires to
117 departments of general surgery in Japanese university hospitals. We received
answers from 77% of the departments. We analyzed their answers, and compared the
answers with those from a similar survey done in 1995 by Japan Society of
Anesthesiology, one in which anesthesiologists were asked to evaluate themselves.
Our most significant findings were as follows. (1) Although most of surgeons were
satisfied with their own preanesthetic evaluation of their patients, 30% of the
departments reported postponement of surgery due to the need of further
examination during recent 2 months and the occurrence of peri-operative
myocardial infarction during recent 2 years, (2) The 1995 survey indicated that
46 percent of anesthesiology departments had explained the major perioperative
risk, but a half of the 46% had done so without discussing the risk with
responsible surgeons. Furthermore, the present survey showed that only 17% of the
surgery departments had been aware of such explanation done by anesthesiologists.
(3) One-third of the anesthesiology departments did not document the text of the
preanesthetic explanation to patients. In our opinion, the final responsibility
for the patient's peri-operative care is primarily the surgeon's at present in
Japan, although each specialist including the anesthesiologist and the
cardiologist should share the responsibility. If the anesthesiologist explain the
major peri-operative risk to the patient without first obtaining the surgeon's
permission to do so, the patient may become confused about who is responsible for
his or her care. It should be made clear to the patient what responsibility each
doctor has. It is also important that all explanations given to a patient and the
consent to anesthesia given by a patient be properly documented. Japanese
anesthesiologists and surgeons need to work far more closely together with regard
to pre-anesthetic evaluation and explaining patients about their peri-operative
risk.
PMID- 10689837
TI - [Factors influencing the level of spinal anesthesia: (I). Characteristics of
anesthetic solutions].
AB - The practitioner of spinal anesthesia needs to know the minimum block he or she
can expect in order to guarantee the adequate anesthesia to perform a given
operation. At the same time, the anesthesiologist needs to know the maximum
extent of block, for which he or she must be prepared to avoid being caught
unaware. The height of sensory block is determined by the cephalad distribution
of the local anesthetic in the cerebrospinal fluid and uptake by neuronal tissue
in sufficient amounts to produce the block. Out of many factors that have been
considered to affect the distribution, this paper discusses characteristics of
anesthetic solutions. It has been suggested that solutions that are marginally
hyperbaric can safely produce relatively consistent blocks with an extent that is
suitable for many operations performed under spinal anesthesia.
PMID- 10689838
TI - [A case of water intoxication during transcervical resection of the uterine
myoma].
AB - A 28-year-old woman underwent trans-cervical resection (TCR) of the uterine
myoma. She had no history of complications except for anemia. Anesthesia was
maintained with inhalation anesthesia. After 120 min from introducing the
resectoscope, her serum sodium dropped to 86.1 mEq.l-1. But her heart rate and
the systolic arterial pressure were stable. She was treated with steroid,
mannitol, isotonic saline, and 7% NaHCO3. Soon after the end of the operation,
she recovered consciousness. At two hours postoperatively, her serum sodium was
119.6 mEq.l-1. On the 1st postoperative day, her serum sodium returned to the
normal range (137 mEq.l-1). We should be aware of asymptomatic water intoxication
during TCR.
PMID- 10689839
TI - [Anesthetic management of a patient with hemophilia A for left modified Blalock
Taussig shunt].
AB - We gave anesthesia to a patient with hemophilia A for left modified Blalock
Taussig shunt. The patient was a twenty five-day-old boy with pulmonary atresia.
We performed the bolus injection test of factor VIII concentrate in preoperative
period. His factor VIII activity increased from 9.3 to 113.3% after a bolus
injection of 165 units. To keep his factor VIII activity above 80% in
perioperative period, a bolus of 125 units of recombinant factor VIII concentrate
was injected at anesthesia induction, 125 units 2 hours after the start of the
operation, and 125 units 6 hours after the end of the operation. Factor VIII
activity 2 hours after anesthesia induction increased only 37.8%, and we had to
infuse recombinant factor VIII concentrate additionally. We measured factor VIII
activity during operation, and he finally received total of 415 units of factor
VIII concentrate. Hydroxyethyl starch infusion, blood transfusion and bleeding in
the perioperative period might have caused the factor VIII activity to decrease
beyond our expectation. We should infuse factor VIII concentrate properly
measuring the factor VIII activity during this operation.
PMID- 10689840
TI - [The anesthetic management for elective or emergent cesarean section in patients
with intracranial arteriovenous malformation].
AB - Subarachnoid hemorrhage secondary to ruptured intracranial arteriovenous
malformation (AVM) during pregnancy, although rare, is a grave complication. We
experienced 3 patients with AVM for cesarean section. Case 1: A 24-year-old woman
suffered sudden vomiting and headache during the 22nd week of her first
pregnancy. She was diagnosed as having the intracranial hemorrhage due to AVM.
Because the patient was bleeding again at 29th week of pregnancy, emergency
operation was performed. Her neurological symptom improved. Cesarean section was
performed under general anesthesia at 34th week of pregnancy. Case 2: A 42-year
old woman of her first pregnancy had past history of subarachnoid hemorrhage due
to AVM at the ages of 23, 28, 29 and 36. The malformation was not corrected
surgically. Her neurological status was normal. Cesarean section was performed
under spinal anesthesia. Case 3: A 29-year-old woman suffered sudden hemiplegia,
vomiting and headache during the 40th week of her first pregnancy. She was
diagnosed as having intracranial hemorrhage. Cesarean section immediately
followed by the removal of an intra cranial hematoma under general anesthesia.
Better perinatal outcome is expected when AVM rerupture is prevented by first
performing cesarean section.
PMID- 10689841
TI - [Iatrogenic extrapleural hematoma].
AB - We encountered a rare case of complications at the time of central venous
catheterization due to extrapleural hematoma. A 71-year-old woman was scheduled
to undergo subtotal gastrectomy. After introduction of general anesthesia, a CVP
catheter was inserted from the right jugular vein, but it was removed
intraoperatively, because of poor dropping of the infusion fluid. A few minutes
later, the blood pressure started to decrease. We considered that this symptom
was derived from the surgical procedure, and rapid blood transfusion associated
with administration of a vasopressor was performed. Postoperative chest X ray
revealed poorly delineated right lung field, and hemothorax was suspected.
However thoracic drainage resulted in an extremely small amount of blood-like
fluid. The abnormal defect in the right pulmonary field was found to be an
extrapleural hematoma by thoracic CT on the first postoperative day. The hematoma
was reduced by subsequent management in 7 days, and the patient was discharged
from the ICU without any further complications.
PMID- 10689842
TI - [Malfunctioning of cerebral function monitors in three cases of carotid
endarterectomy].
AB - In three patients, EEG, jugular venous oxygen saturation (Sjvo2) and near
infrared spectroscopy (NIRS) were monitored to detect cerebral ischemia during
carotid endarterectomy. In all cases, no changes in Sjvo2 and NIRS were observed
during carotid artery occlusion, but in two patients EEG showed changes when
carotid artery was clamped. It is important to know the precise mechanism of
cerebral monitors to assess the cerebral ischemia in patients with preexisting
neurological disorder during carotid endarterectomy.
PMID- 10689843
TI - [Anesthetic management in a patient with severe acute pancreatitis during
pregnancy].
AB - Continuous epidural anesthesia was used in a 34 year-old pregnant woman with
acute pancreatitis related to hypertriglyceridemia. She underwent an emergency
cesarean section due to severe pancreatitis under spinal anesthesia. After
delivery, extended incision was made to examine the pancreas and to perform
drainage. Epidural infusion using 1% mepivacaine and buprenorphine was started to
reduce pain and improve microcirculation. After starting epidural infusion with
other therapies, clinical feature and data improved. This case suggests that
reduction of severe pain and improvement of microcirculation are important in
therapies of severe pancreatitis.
PMID- 10689844
TI - [Heart rate reduction using edrophonium during coronary artery bypass grafting
without cardiopulmonary bypass].
AB - Coronary artery bypass grafting without the use of cardiopulmonary bypass (CPB)
is performed with increasing frequency. Performing revascularization on a beating
heart is technically more demanding than performing revascularization on the
arrested heart, especially in high-risk patients. beta-Blockers and calcium
channel antagonists have been used for the reduction of heart rate (HR) for the
local immobilization of the anastomotic site. However, their negative inotropic
actions often lead to serious hypotension. Therefore, we investigated the effect
of edrophonium on HR reduction in high-risk patients undergoing CABG without CPB.
Ten high-risk patients undergoing CABG without CPB were selected. To reduce HR
during anastomosis, edrophonium was administered during the procedure. Systemic
blood pressure (sBP), HR, and cardiac index (CI) were measured from the induction
of anesthesia to the end of surgery. All surgeries were successfully performed
without serious complications. To keep the rate under 60 bpm, edrophonium was
administered at the time of anastomosis and this decreased the cardiac index from
2.19 to 1.95, while the sPB was maintained easily over 90 mmHg with the infusion
of methoxamine. Edrophonium may be useful for the reduction of HR during coronary
anastomosis in high-risk patients undergoing CABG without CPB.
PMID- 10689845
TI - [The effect of prophylactic nicorandil infusion to reduce intraoperative
myocardial ischemia during abdominal surgery in patients with risk factors of
ischemic heart disease].
AB - Three hundred patients who had undergone abdominal surgery with risk factors of
ischemic heart disease (IHD), such as hypertension, diabetes mellitus,
hyperlipidemia, smoking, advanced age, obesity, familial history,
electrocardiographic abnormality, other perivascular disease, and male, were
included in this study. Patients older than forty years were included in the
study. They were divided into two groups for a randomized double blind trial:
nicorandil was administered in one group (group N) and placebo in another (group
C), and we investigated the effect of prophylactic nicorandil infusion to reduce
intraoperative myocardial ischemia. ST segment in leads II and Vs was recorded by
ST trend monitor from the time of patient's entering the operating room to the
time to exit. Intraoperative myocardial ischemia occurred in 11 patients in group
N and in 32 patients in group C (P < 0.0001). Prophylactic nicorandil infusion
was effective to reduce intraoperative myocardial ischemia in patients with risk
factors of IHD during abdominal surgery.
PMID- 10689846
TI - [Sudden cardiac arrest after induction of general anesthesia: a case report].
AB - We experienced sudden cardiac arrest after induction of general anesthesia using
isoflurane. The patient had had paroxysmal atrial fibrillation for one year and
had been treated with digoxin and cibenzoline succinate. Sinus rhythm appeared
soon after the start of closed chest compression. However cardiac arrest
recurred, and we inserted a temporary pacemaker catheter to stabilize the
circulatory status. She awoke from anesthesia without any complications. The
diagnosis of sick sinus syndrome (SSS) was made postoperatively and she had a
permanent pacemaker implanted. We thought that the hidden SSS had been the cause
of this sudden cardiac arrest.
PMID- 10689847
TI - [Anesthetic management for a patient with spondyloepiphyseal dysplasia
congenita].
AB - An 11-year-old girl with spondyloepiphyseal dysplasia congenita in the spine was
scheduled for virectomy under general anesthesia. She had slight scoliosis in the
thoracic and lumbar spine, moderate funnel chest and slight thoracic kyphosis.
Preoperative laboratory data were within normal range and her intelligence was
normal. Her Mallanpathi's score, however, was Grade 3 and effective mandibular
length/posterior depth of mandible ratio was 3.48 on the lateral view of head X
ray. From these data, difficult intubation was expected. Although anesthesia was
induced uneventfully using thiamylal and vecuronium, her vocal cord was not
visualized under laryngoscope. Using cricoid pressure procedure, slightly left
shifted vocal cord was exposed. However a 26 Fr. size endotracheal tube without
cuff was too large and finally a 22 Fr. tube was inserted. During the operation
patient's general condition was stable and the operation was finished without any
episodes. She did not have any complications in the postoperative period. In a
case of SDC, pathological changes in laryngotracheal resion should be examined
and evaluated preoperatively and difficult intubation should also be always taken
into account.
PMID- 10689848
TI - [Tracheal mucosal bulla found on tracheal extubation in a patient with pemphigus
vulgaris--a case report].
AB - A 49-year-old female with pemphigus vulgaris underwent the removal of a
meningioma under general anesthesia. Neither bulla nor erosion was observed on
her skin and oral cavity mucosa. She had been on prednisolone 15 mg for six years
daily to avoid the recurrence of skin lesion. Anesthesia was induced and
maintained with total intravenous anesthesia with propofol and fentanyl. No
adverse episodes were encountered during the operative procedure. We checked the
tracheal mucosa using bronchofiberscope before extubation. A small bulla was
found on the tracheal mucosa, where the cuff of the tracheal tube was located.
The trachea was extubated slowly under bronchofiberscopic observation, and no
other bullae were found. It would have been formed by mechanical stimulation of
the tracheal tube. This case suggests that we have to pay careful attention to
the formation of bullae at any part of the body by mechanical stimuli during
anesthetic management of patients with pemphigus vulgaris.
PMID- 10689849
TI - [Anesthetic management of a patient with West syndrome].
AB - A 21-year-old female with West syndrome was scheduled for resection of hordeolum.
She had an episode of convulsion at three months of age, and was diagnosed as
having West syndrome at one year of age. She had epileptic seizures twice a week
in spite of administration of phenytoin, clonazepam and sodium valproate. These
drugs had been administered till the morning of the surgery. After premedication
with atropine 0.25 mg, anesthesia was induced with propofol (12-->10-->8 mg.kg
1.h-1). The tracheal intubation was performed with vecuronium 0.1 mg.kg-1 and
anesthesia was maintained with continuous infusion of propofol 6-8 mg.kg-1.h-1
and local infiltration with 1.0% lidocaine 5 ml. We administered phenytoin to
prevent epileptic seizures during the surgery. No epileptic seizures occurred
perioperatively. We conclude that propofol may be useful for a patient with West
syndrome, and we should be careful not to lower the threshold for convulsion
during the perioperative period.
PMID- 10689850
TI - [Respiratory muscle weakness after prolonged use of hydrocortisone and
pancuronium bromide].
AB - A 30-year-old man was admitted because of status asthmaticus. He required 7 days
of artificial ventilation and was treated with hydrocortisone 1.2 g.day-1 and
bronchodilaters. Pancuronium bromide 0.08 mg.kg-1.hr-1 was given for 64 hours for
the ease of artificial ventilation. On day 3, severely elevated airway pressure
resulted in left pneumothorax and isoflurane 1% was given for the following 2
days. Respiratory muscle weakness was evident 24 hours after discontinuation of
pancuronium infusion on day 5 while full 4 twitches of TOF on the adductor
pollicis muscle were seen at the time. The respiratory muscle weakness continued
for another 3 days and he was extubated on day 8. Serum creatine kinase
concentration rose to 2178 U.l-1 on day 6 and returned to normal on day 11.
Hematurea, hyperpyrexia and metabolic acidosis were never seen during the course.
Acute corticosteroid myopathy was suspected to be the cause of the prolonged
respiratory muscle weakness.
PMID- 10689851
TI - [A nationwide survey of anesthesia for laparoscopic and thoracoscopic surgeries].
AB - This is the report the first nationwide survey of anesthetic management for
laparoscopic and thoracoscopic surgeries. We mailed a questionnaire to
anesthetists of 133 hospitals in Japan and 74 completed questionnaires were
returned. The number of intra-abdominal and thoracic surgical procedures has been
increasing. General anesthesia was used in all cases for endoscopic surgery. The
double lumen tube was selected in 79% of patients with pneumothorax for the
endobronchial intubation. Patients for the laparoscopic cholecystectomy (LC) were
given various types of anesthetics. Thirty-two percent of patients who underwent
LC was anesthetized with inhalation anesthetics combined with epidural anesthesia
for the early ambulance and postoperative pain control. The maximum length of
time for LC surgery was 12.5 hr. Complications related to laparoscopic surgery
included bile duct injuries in 72 patients, postoperative bleeding in 32
patients, vascular injuries in 29 patients, pneumothorax in 26 patients,
bronchial intubation in 17 patients, gas embolism in 11 patients, bowel injuries
in 9 patients and postoperative ileus in 7 patients. Administering anesthesia for
endoscopic procedures requires precise knowledge of the surgical procedures,
physiologic changes and complications of the pneumoperitoneum, and one lung
ventilation.
PMID- 10689852
TI - [Manual chest compressor for cardiac massage for patients transported on a litter
-Part 2: Return to the air balloon method and the future direction of the study].
AB - The prior idea of sternal compression with an inflatable balloon inserted between
the chest wall and the precordial metal plate was not realized due to the
compressibility of gases. Based on the thoracic pump theory of cardiac massage,
an accordion type balloon with a wider contact area to the chest wall was made
after many years' of unsuccessful trials of various energy transmission methods.
Since the compression power to the chest with this device does not exert extra
weight underneath the patient, it can be used on a patient being transported on a
litter. It is a simple, safe and light weight device and can be used on a
helicopter as well, because the balloon can be inflated from an adjacent seat in
the helicopter. Applying the principle of lever, it demands less muscle work
compared with the conventional method of cardiac massage. Therefore, it may be
useful even in hospitals. For the push-pull method of cardiac massage, however,
an electric device may be promising when a.c. electricity or a light weight
battery is available.
PMID- 10689853
TI - Looking to the past for the sake of the future.
PMID- 10689854
TI - From ABO to DNA...
PMID- 10689855
TI - A profession in flux.
PMID- 10689856
TI - The role of the medical examiner in the euthanasia notification procedure in The
Netherlands.
AB - The objective of the study was to provide an insight into the role of the medical
examiner in the euthanasia notification procedure in The Netherlands. At the
beginning of 1996 a representative group of 116 medical examiners was
interviewed. The study found that there was a considerable variation in the way
in which the medical examiners fulfilled their tasks. In all cases, after the
physician-assisted death had taken place, the medical examiner investigated
whether the attending physician had met the requirements for prudent practice,
and in approximately 75% of the cases he reported his findings to the Public
Prosecutor. In 78% of cases the attending physician was well known to the medical
examiners, who were general practitioners, and in a third of the cases this
influenced their assessment. Seventy-six per cent of the medical examiners, 61%
of the members of the public prosecution and 47% of the physicians thought that
it is the task to the medical examiner to review whether the requirements for
prudent practice have been met by the attending physician. In conclusion further
specification of the task of the medical examiner would appear to be beneficial
to increase uniformity in the procedure. In particular, it should be determined
whether it is the medical examiner's responsibility to review whether the
requirements for prudent practice have been met. It should also be taken into
consideration whether the position of the general practitioner medical examiner
is sufficiently independent to make an objective report.
PMID- 10689857
TI - Autopsy in elderly psychiatric inpatients: a retrospective review of autopsy
findings of deceased elderly psychiatric inpatients in north Cheshire 1980-1996.
AB - In this 17-year review of death certificates of elderly inpatients of a large
psychiatric hospital in North Cheshire, the frequency, trend and value of
performing autopsies were examined. Details of death certificates were compared
with certificates issued after post-mortem examination to see whether an autopsy
yielded any additional or relevant information about conditions that are not
directly related to death but might well be of importance to public health. The
rate of post-mortem examination, at 9.5% of total hospital deaths, did not show
any significant trend over most of the review period. The vast majority of
autopsies examined had been requested by the coroner and not by the clinicians.
The review showed that an autopsy may be of some value in providing more
information regarding any underlying causes of death in elderly psychiatric
patients, but has no value in ensuring higher rate of the recording of conditions
such as dementia, in particular Alzheimer's disease. Selective hospital autopsy
in elderly psychiatric patients to verify, neuropathologically, the clinical
diagnosis of Alzheimer's disease, will improve our diagnostic accuracy and
provide valid statistics to be used in estimating prevalence, trends, risk
factors and for use in all aspects of future research into Alzheimer's disease.
PMID- 10689858
TI - Russian forensic psychiatry.
AB - Two forensic psychiatric clinics visited on an exchange trip to Russia are
described. The legal system for mentally disordered offenders in these
institutions is also summarized, as is the training of psychiatrists in Russia.
PMID- 10689859
TI - An exploration of the concept of loneliness in forensic psychiatry.
AB - Subjective aspects of social support and loneliness were examined in a group of
30 forensic inpatients in secure units and were compared to a control group of 31
surgical inpatients. The secure-unit patients were more lonely and experienced
the deficiencies in their social relationships in a different way to the
controls. Loneliness for the secure-unit patients was a more unpleasant
experience and more associated with difficulties in forming close attachments.
There was a high correlation between loneliness and the personality trait of
psychoticism in the secure-unit group which was not found in the controls. These
results underline the serious problems of these patients with relationships and
suggest the development of intervention programmes.
PMID- 10689860
TI - Sudden death during restraint: a study to measure the effect of restraint
positions on the rate of recovery from exercise.
AB - A small number of mental health patients have died suddenly following violent
behaviour and restraint by staff. The safety of certain restraint positions has
been questioned. This study evaluates two control and restraint (C & R) positions
commonly used by health service staff. A repeated measures design was used to
study rate of recovery from exercise in volunteer staff, measured by pulse
oximetry, comparing the restraint positions with a seated (control) position. It
was found that the recovery time for pulse rate of subjects restrained in a face
down position was significantly longer than for subjects restrained in a face-up
position. No significant findings were made in terms of comparison between the
control position and the restraint positions, and no significant changes in
oxygen saturation were noted during restraint. It is concluded that restraint
position may be a factor in death during restraint, but only where other factors
contribute to the overall situation.
PMID- 10689861
TI - Sudden unexplained death syndrome.
AB - A retrospective investigation of 51 cases of sudden unexplained death syndrome
(SUDS) reported to the Medico-Legal Centre in Dammam during the period January
1995 to June 1997 was carried out. The vast majority of SUDS victims were Indians
(43%). The study reports SUDS in non-East Asian subjects, including indigenous
Saudis, for the first time. Autopsy examination was carried out on 22 subjects
and did not reveal any significant pathological lesions which could fully explain
the sudden death. However, seven cases showed mild to moderate cardiac
hypertrophy (of whom two had mild to moderate coronary stenosis), and another
four showed a similar degree of coronary narrowing without any evidence of
myocardial hypertrophy. Severe pulmonary congestion and alveolar haemorrhage were
noticed in 18 of the autopsied cases. Microbiological tests were performed on
different specimens from 27 subjects and showed significant bacterial growth in
seven cases. The paper reviews different hypotheses explaining SUDS and suggests
areas of further study in such deaths.
PMID- 10689862
TI - Increasing the power of psychiatric court diversion: a new model of supra
district diversion centre.
AB - The object was to develop and evaluate a new concentrated model of psychiatric
diversion scheme at the magistrates' court, designed to maximize the potential of
such interventions. A one-year prospective study was undertaken of a consecutive
series of 264 referrals to the new diversion project at an Inner London
magistrates' court, with concurrent examination of police station custody
records, magistrates' court returns, hospital admission data and remand prison
transfer records for an area with a population of 500,000. The results showed
that this one scheme originated 12.8% of all the unrestricted hospital orders in
England under section 37 of the Mental Health Act 1983, 4.2% of section 35
orders, and 6.4% of section 48 and 48/49 remand prisoner transfers. Of all
arrests in the central London area, 0.46% were referred to the scheme, with 0.28%
being admitted. The seriousness of the charge did not have a significant effect
on whether or not admission was achieved (p = 0.5365). The new model is a
powerful intervention in the assessment and diversion of mentally disordered
offenders. Similar supra-district diversion centres may have a role to play in
other areas, complementing other local diversion exercises, some of which might
better be relocated to the police station.
PMID- 10689863
TI - Methadone-related deaths: data from 18 coroners' jurisdictions in England.
AB - This paper examines the methadone-related deaths (MRD) among entire cases of
inquest on drug-related cases in 18 coroners' jurisdictions in England which were
entered on the National Programme on Substance Abuse Deaths during a six-month
period in 1997. In 154 deaths methadone, either prescribed or not prescribed, was
reported to be the substance directly implicated in the death of 40 individuals.
The MRD between the prescribed and non-prescribed cases were compared in respect
to various demographic variables and associated risks. The main findings reported
are that the majority of deaths in this sample were in cases where methadone had
not been prescribed (72%) and that there was a significant difference in age
between the methadone prescribed (median = 22 years) and non-prescribed groups
(median = 37 years) (Mann-Whitney U = 57.5, p = 0.01). Also significant
differences amongst the two groups in respect of the coroners' verdicts are
reported. The authors suggest more stringent controls around the prescription and
dispensing of methadone, along with measures to alert the population at risk of
the hazards of using methadone in a non-controlled fashion.
PMID- 10689864
TI - Observation on the recent examination of bones from St David's Cathedral.
AB - Bones discovered in 1866 walled up in St David's Cathedral, West Wales were
thought possibly to be those of St David and his companion St Justinian, both of
whom died in the late 6th or early 7th century. Examination and radio carbon
dating of the bones suggested that these were not from St David nor St Justinian.
Some of the bones could be the remains of St Caradoc, a 12th century hermit. It
is likely, however, that the bones are remains of clergy who, for reasons not yet
understood, were re-interred into the wall.
PMID- 10689865
TI - Forensic medicine in the Rivers State of Nigeria: experience in four rural
general hospitals.
AB - A retrospective study of 375 consecutive medicolegal cases seen in four
peripheral general hospitals in the Rivers State of Nigeria over a five-year
period (March 1984 to February 1989) was undertaken. The most common indications
for forensic medical consultation were assaults (78.6%) using clubs, sticks,
fists and machetes as weapons, road traffic accidents (9.1%) and sexual offences
(7.7%). The proportions of accidental deaths (4.3%), homicidal deaths (2.9%),
sudden natural deaths (0.5%), maternal deaths (0.5%) and suicidal deaths (0.3%)
were much lower. The male-to-female ratio was 1.4 to 1. The patients' ages ranged
from 10 months to 75 years, with a mean of 31.6 years. Twenty-three cases (6.1%)
were children, while the remaining 352 cases (93.9%) were adults. The study
showed that for those cases which do come to the pathologist's attention,
forensic personnel and laboratory services are inadequate in the peripheral parts
of Nigeria. The study also highlighted the possible range of medicolegal problems
of which the medical practitioner should be aware, even if he is practising in
the rural non-urbanized areas of Nigeria. The study shows that not all deaths are
registered in Nigeria.
PMID- 10689866
TI - Maternal mortality following the use of misoprostol.
AB - Three cases of maternal death following the use of misoprostol are presented. In
two of the cases the drug was used to procure illegal abortion, and in the third
case maternal death occurred following uterine rupture, after misoprostol was
used clinically for induction of labour. A brief review of the usage of
misoprostol is presented, including recommendations for its safe use.
PMID- 10689868
TI - The HIV positive mother.
PMID- 10689867
TI - A fatal nail gun injury--an unusual ricochet?
AB - An 18-year-old construction worker suddenly collapsed while handling a power
actuated nail gun and died shortly after. A neat, almost circular puncture wound
was found on the front of his left chest. No fire-arm residues were detected on
the surrounding skin. The police stated that it was an accidental injury, at a
construction site, where a nail fired from a nail gun by the deceased had
deflected off the wall and struck him on the front of the chest. Since the entry
wound appeared to be a neat hole, and that too on the front of the left chest
overlying the heart area, there was reluctance on the part of the pathologist to
accept it as an accidental injury due to a ricochet. A visit to the scene,
interrogation of witnesses, examination of the alleged tool and post-mortem X-ray
of the deceased were undertaken prior to autopsy. A bent nail was found in the
heart. The scene visit and the subsequent autopsy revealed that the nail took a
roughly circular flightpath after it had struck the wall, all the while
travelling with its pointed end directed forward. Within the body too, the nail
maintained the same path. Various medicolegal issues are discussed pertaining to
nail-gun injuries. The importance of a visit to the scene, examination of the
alleged tool, interrogation of witnesses and the X-ray of the body, all prior to
autopsy, are emphasized. The conclusion was: accidental death due to the unusual
ricochet of a nail.
PMID- 10689869
TI - Use of granulocyte colony-stimulating factor for treatment of aplastic anemia.
AB - Over the last ten years, recombinant human granulocyte colony-stimulating factor
(rh G-CSF) has been widely used in the treatment of aplastic anemia (AA). It has
been shown to facilitate the recovery of neutrophil count and useful for
complicated bacterial or fungal infections. However, recent randomized clinical
trials showed that the addition of rh G-CSF to immunosuppressive therapy had no
clinical benefit for the prophylaxis of severe infections. These results
suggested that rh G-CSF should be used for the treatment of infectious
complications, not for the prophylaxis of infections in patients with AA.
PMID- 10689870
TI - Progress in diagnosing herpesvirus infections.
AB - As molecular biology has developed, several new diagnostic techniques have found
application in the clinical setting. The use of the polymerase chain reaction
(PCR) assay to study the molecular biology of microbial organisms has led to
unparalleled advances, largely due to the rapidity with which results can be
obtained. The sensitivity and specificity of PCR detection of viral DNA for
diagnostic purposes are remarkable. With such excellent sensitivity, PCR is
destined to become a useful diagnostic tool in herpesvirus infections. However,
it is well known that herpesviruses establish latency after primary infections
and that they can often be reactivated under various conditions. Because of the
high sensitivity of PCR, detection of virus sequences by this method does not
necessarily imply a disease state. We must be careful not to overdiagnose
conditions in a clinical setting based on a PCR assay.
PMID- 10689871
TI - NK and NK-related neoplasms.
AB - Owing to the immunological progress in recent years, differentiation and
maturation process of NK cells or NK-related cells has been made clear. Also,
their neoplastic counterparts, namely NK cell related lymphoma/leukemia have been
characterized. In this paper, we will report NK cell neoplasms based on the new
classification of malignant lymphomas. Among these, nasal lymphoma is one of the
most clearly defined entities, followed by NK cell leukemia/lymphoma, and
blastic/blastoid NK cell leukemia/lymphoma.
PMID- 10689872
TI - A new operation for noncorrectable biliary atresia.
AB - An improved operative technique to transect the fibrous cord by dividing the
ligamentum venosum (Arantius' canal) is described for noncorrectable biliary
atresia. The Arantius' canal is situated cranial and posterior side to the
bifurcation of the umbilical portion and the portal branch of the Quinous'
segment 3. The portal vein is fully mobile and the porta hepatis can be widely
exposed by dividing the Arantius' canal. The fibrous cord of the porta hepatis
can easily be dissected posteriorly and laterally where there is an extensive
number of bile ducts. Eight patients with biliary atresia underwent this
procedure. Jaundice resolved completely (serum total bilirubin concentration: <
or = 1 mg/dl) in 7 patients within 40 days. Postoperative cholangitis did not
occur. By dividing the Arantius' canal, the portal vein comes free from the
portal fissure to make the hepatic hilum wider, and surgeons are able to work
within a larger porta hepatic space without causing portal vein compression. Free
drainage of the bile from the porta hepatis may prevent postoperative cholangitis
and promote resolution of jaundice.
PMID- 10689873
TI - Effects of sodium hyaluronate on experimental osteoarthritis in rabbit knee
joints.
AB - The aim of this study was to examine the effects of intraarticular administration
of hyaluronan (HA) on cartilage degradation. Using a partial menisectomy model of
osteoarthritis (OA) in the rabbit knee, the authors investigated the catabolic
and anabolic changes induced by intraarticular injection of HA. To analyze
anabolic changes, the authors assessed cell proliferation by measuring [3H]
thymidine uptake, and proteoglycan biosynthesis by noting [35S] sulfate
incorporation. For catabolic changes, messenger ribonucleic acid (mRNA)
expression of interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), and tissue
inhibitor of metalloproteinase-1 (TIMP-1) in cartilage and synovium were detected
with reverse transcriptase polymerase chain reaction (RT-PCR). Of significance
for blocking the development of early OA in chondrocytes was the finding that
total proteoglycan synthesis in the HA treatment group was significantly higher
than in the controls. At the mRNA level in cartilage and synovium, HA inhibited
MMP-3 and TIMP-1 production in the same way in the HA treatment group, while not
affecting MMP-1 production. Thus it can be concluded that HA affects cartilage
catabolism and anabolism to prevent the progress of OA.
PMID- 10689874
TI - [Empiric and mechanistic evaluation model for lactate concentration time curves
in endurance tests].
PMID- 10689875
TI - Acute myeloid leukemia in the elderly:--159 Nagoya case studies--Nagoya
Cooperative Study Group for Elderly Leukemia.
AB - To obtain background information on elderly acute myeloid leukemia (AML),
unselected data covering 159 patients aged 60 years or over with AML from 14
hospitals in Nagoya, Japan was analyzed retrospectively. Among these patients,
119 had de novo acute AML, 32 had AML which evolved from myelodysplastic syndrome
(MDS-AML), and 8 had other types of leukemia. The survey showed that MDS-AML
tended to be more prevalent in patients aged 70 years and older and that MDS-AML
showed a significantly more severe degree of leukopenia and anemia than de novo
AML. MDS-AML also showed a significantly lower complete remission (CR) rate than
that of de novo AML [6.9% (2/29) vs 58.3% (67/11), P < 0.01] and significantly
shorter survival times than those of de novo AML [median: 3.6 months vs 9.6
months, P < 0.01 (generalized Wilcoxon test; GW]. In de novo AML, the proportion
of patients treated with conventional therapy (CT group) decreased significantly,
and that of those with attenuated therapy (AT group) increased significantly as
age elevated (P < 0.01). The CT group showed a significantly higher CR rate
(65.4% vs 41.2%, P < 0.05) and a significantly longer survival period than those
of the AT group [median: 11.6 months vs 4.8 months, P < 0.05 (GW)]. Overall
survival rates of the older age groups became significantly shorter with aging [P
< 0.01 (GW)].
PMID- 10689876
TI - [The result of mass screening of 1997 for prostatic cancer in Isesaki City].
AB - PURPOSE: Screening by only prostate specific antigen (PSA) for prostate cancer
was started since PSA had been added to mass screening as one of check lists in
1997 in Isesaki city, Gunma pref. We expected PSA screening to be introduced into
other areas. We therefore studied how to perform a screening procedure for
prostate cancer as well as discussed our result of the screening conducted
lately. MATERIALS AND METHODS: 1,382 out of 1,423 Isesaki citizens who took mass
screening aged 40 to 64 were chosen. Regardless of age, men with a serum PSA
level equal or larger than 4.1 ng/ml (Tandem R) were selected for second
screening since we determined it was a cut-off level for further check-up. Of
those men, 38 were requested for second screening and actually only 24 took it.
All these men took PSA check-up again, furthermore 23 took transrectal
examination (TRE) and/or transrectal ultra sonography (TRUS) except for one of
them. The next screening was requested for sixteen of them. Prostate biopsy was
conducted for all of them. RESULTS: More old men took screening and were
diagnosed prostate cancer. The findings derived from such diagnosis showed one of
them aged 50 to 59 and six of them aged 60 to 64 had the cancer. Moreover, four
out of twenty with PSA level ranging 4.1 to 10.0 ng/ml and all of three with PSA
level over 20.0 ng/ml had the cancer. Five out of sixteen with a positive sign
for further PSA check-ups had the cancer. All the three suspect of the cancer by
TURS and DRE had prostate cancer. Two of seven with PSA negative showed suspicion
of prostate cancer and had the cancer. No neo-adjuvant and total prostatectomy
was conducted for four with 4.0 to 10.0ng/ml diagnosed T2N0 M0. One of them with
PSA equal or over 20.0 ng/ml was diagnosed T3N0M0. After hormone therapy its PSA
decreased to that equal or under 0.5 ng/ml. Total prostatectomy was conducted for
it. CONCLUSION: It is not proved that only PSA mass screening for prostatic
cancer contributes to detect early cancer and better prognosis cure case. For the
proof, it will be nessary that PSA mass screening is examined more people in the
wide area. We conclude men aged 65 to 69 also should take PSA check-up based on
epidemiological feature of prostatic cancer.
PMID- 10689877
TI - [Autologous blood transfusion in surgery of urologic malignant tumor].
AB - BACKGROUND: Autologous blood transfusion has been widely endorsed, because of the
adverse effects attributed to homologous blood transfusion. So we employed
autologous blood transfusion to avoid homologous blood transfusion in operation
of urological malignant patients. We reviewed our experience with autologous
blood transfusion in 48 patients. METHODS: A total of 48 patients underwent
operation with 400 to 1,200 ml preoperative autologous blood donation, in 41
patients with administration of erythropoietin and 7 patients without
erythropoietin. The details of operations are radical nephrectomy in 18 cases (2
cases were bilateral), radical nephro-ureterectomy in 2 cases, retroperitoneal
lymph node dissection (RPLND) in 2 cases, radical prostatectomy in 12 cases and
radical cystectomy in 14 cases. RESULTS: The volume of surgical blood loss were
381 +/- 522 ml in nephrectomy (1,158 +/- 202 ml in bilateral case), 517 +/- 5 ml
in radical nephro-ureterectomy 636 +/- 574 ml in RPLND, 665 +/- 291 ml in radical
prostatectomy and 1,123 +/- 417 ml in radical cystectomy. Only three cases needed
homologous blood transfusion. CONCLUSION: We can avoid homologous blood
transfusion in 94% of patients. Autologous blood transfusion is recommended as
safe and convenient.
PMID- 10689878
TI - [Kinetics of peripheral blood CD34-positive cells and the optimum timing for
harvesting peripheral blood stem cells during BEP chemotherapy in patients with
testicular germ cell tumor].
AB - PURPOSE: Recently, high-dose chemotherapy with peripheral blood stem cell (PBSC)
rescue has been developed for poor risk testicular germ cell cancer. In this
study, we investigated the optimum timing for harvesting PBSCs with the use of
bleomycin + etoposide + cisplatin (BEP) chemotherapy, which is a well known first
line regimen for the testicular cancer. MATERIAL AND METHOD: Peripheral blood
CD34-positive cell ratios were measured during a total of 10 courses of BEP
chemotherapy in 6 patients with metastatic germ cell cancer between 1996 and
1998. We performed 4 apheresis in 3 patients during this period. Recombinant
human granulocyte-colony stimulating factor (rhG-CSF) was administrated from the
day on which the neutrophil count decreased less than 1,000/microliter. RESULTS:
The peripheral blood CD34-positive cell ratios became maximum (3.0-24.6%; average
10.0%) on the day 18 to 21 (median day 19) of BEP chemotherapy with rhG-CSF
administration. The maximum ratios of peripheral blood CD34 positive cells were
achieved when the number of leukocyte were 6,880-23,600/microliter and exceeded
6,000/microliter after the 18th day of BEP chemotherapy. The average number of
collected CD34 positive cells was 9.5 x 10(6)/kg at a single apheresis, and 12.6
x 10(6)/kg per patient. CONCLUSION: Efficient hematopoietic progenitor cells were
mobilized by BEP chemotherapy with rhG-CSF administration of first-line setting.
Our results suggest that the optimum timing of PBSCs harvest is the day when the
numbers of leukocyte exceed 6,000/microliter after the 18th day of BEP
chemotherapy and the following day.
PMID- 10689879
TI - [The quality of life after radical prostatectomy measured by general health
questionnaire and visual analogue scales].
AB - OBJECTIVES: The impact of radical prostatectomy on the quality of life (QOL) of
patients were evaluated. MATERIALS AND METHODS: A total of 22 patients who
underwent radical prostatectomy for clinically localized prostate cancer entered
this study. Patients were asked to complete a questionnaire containing the
general health questionnaire (GHQ) and a series of questions evaluating voiding
function, incontinence and sexual dysfunction before and after the operation. In
addition, the visual analogue scaled (VAS) questionnaire containing incontinence
and sexual dysfunction was applied. RESULTS: No significant differences in GHQ
were found between pre- and post operative status, but disease-targeted QOL such
as sexual function was affected after the radical prostatectomy. In the points of
incontinence and sexual dysfunction, VAS questionnaire significantly correlated
with those of categorical questionnaires. CONCLUSIONS: There results suggest that
GHQ is not affected, but disease-targeted QOL in some categories of sexual
function is affected by radical prostatectomy, and that VAS questionnaires are
not only useful for assessing the disease-targeted QOL but also easy to quantify
QOL of the patients.
PMID- 10689880
TI - [Suicidal attempts in three postoperative patients with renal cancer after alpha
interferon withdrawal].
AB - We report 3 cases of suicide attempts in postoperative patients with renal cancer
after alpha interferon withdrawal. In the first patient, depression occurred
during interferon therapy, and remained after interferon withdrawal. A suicide
attempt occurred 7 months after interferon withdrawal. In the second and third
patients, depression did not occur during interferon therapy, but suicide
attempts occurred 40 days and 7 months after interferon withdrawal, respectively.
Depression does not always disappear after interferon is discontinued.
Psychiatric supervision should be continued even more frequently after interferon
withdrawal. The increased risk of psychiatric side effects due to interferon, as
well as their severity, suggest that interferon should be administered with
caution.
PMID- 10689881
TI - [Familial isolated hyperparathyroidism: a report of two cases].
AB - A family (a brother and a sister) of the familidal isolated hyperparathyroidism
(FIH) was reported. The older brother with age of 58 year-old was pointed out
hypercalcemic while examining his hypertension and proteinuria. He had high
levels of serum total and ionized calcium, intact-PTH and gastrin, and
hypophosphatemia. His neck CT scan revealed swelling of the two parathyroid
glands in each side. He underwent resection of the tumors and the auto
implantation of the glands under diagnosis of primary hyper parathyroidism.
Histopathology was diagnosed to be hyperplasia of the parathyroid glands. The
younger sister with age of 52 year-old was referred to our clinic because she was
suffering from recurrent urolithiasis. Biochemical examination of her blood
sampling resulted in very resemble values of her brother mentioned above. Her
neck CT scan showed three tumors consisting of each one at the bilateral
parathyroid glands and one in the thymic region. She underwent resection of the
tumors and the auto-implantation of the glands and histopathological diagnosis
was hyperplasia as same as her brother's one. The postoperative courses of these
cases have been uneventful for four years. FIH is a low significant disease of
which ten lineages have been reported in Japanese literature although it should
be differentiate with such a disease of multiple endocrine neoplasms.
PMID- 10689882
TI - [Renomedullary interstitial cell tumor: a case report].
AB - Renomedullary interstitial tumor is a common tumor in the renal medulla, present
in 26-41% of consecutive autopsy specimens. However clinically evident case is
infrequent because this lesion is usually small (less than 3 mm). We report a
case of renomedullary interstitial tumor in a 76-year-old woman. Ultrasonogram
incidentally revealed a mass in the left kidney while she visited to the hospital
for hypertension and unstable angina. A CT scan showed a 2 cm mass that was not
clearly enhanced. MR images showed low signal intensity in both T1 and T2 images.
Arteriography demonstrated no neo-vascularity. Those findings showed that this
lesion was benign one or hypovascular carcinoma. So Left nephrectomy was
performed and histological examination revealed a renomedullary interstitial
tumor.
PMID- 10689883
TI - [Diagnostic radiology in acute pediatric abdomen].
AB - Acute pediatric abdomen is a very common clinical problem. Clinical and
laboratory findings, however, are nonspecific or confusing in many instances.
This review article focuses on strategy in diagnosing acute pediatric abdomen. A
variety of diseases such as appendicitis, gastroenteritis, mesenteric adenitis,
intestinal intussusception, Henoch-Scholein purpura, Crohn's disease, Meckel's
diverticulitis, duodenal ulcer, congenital biliary dilatation, ovarian torsion,
and anomaly of the internal genitalia are discussed in this article. Selection of
an appropriate imaging modality is essential to ensure prompt management. In the
majority of cases, ultrasound can provide specific diagnoses, whereas in others
valuable supplemental information can be obtained. CT will be reserved for
selected patients in whom further information is needed. Indications of MR
imaging in the management of acute pediatric abdomen are currently limited. MR
imaging, however, is indicated on an emergency or semi-emergency basis in
selected conditions including anomaly of the internal genitalia, ovarian torsion,
and congenital biliary dilatation.
PMID- 10689884
TI - Initial clinical application of cone-beam CT scan in pulmonary imaging.
PMID- 10689885
TI - [Three-dimensional imaging of hepatic and intrahepatic portal veins with helical
CT: determination of optimal volume of contrast medium by intravenous injection
using MIP technique].
AB - In this study, the optimal volume of contrast medium in the liver for three
dimensional (3D) imaging of the hepatic and portal veins by helical CT were
determined by intravenous injection using the MIP technique. In the 48 cases
examined, CT images of the liver were obtained following the administration of
contrast medium (90, 120, or 150 ml and 1.0 <, < or = 1.5 ml; 1.5 <, < or = 2.0
ml; 2.0 <, < or = 2.5 ml or 2.5 <, < or = 3.0 ml/kg) for determination of the
optimal volume. The mean body weight of the patients was 59 kg. Contrast medium
(Iopamidol 300 mgl/ml) was injected at a rate of 3 ml/sec, and scanning was
initiated 70 sec after the beginning of injection. Images were obtained
throughout the entire liver using 5-mm collimation. MIP images were graded from
poor to excellent based on their visualization of the hepatic vessels. Images
produced with 120 ml of contrast medium presented excellent images of hepatic
vessels, superior to those produced with 90 ml (hepatic vein: p < .001, portal
vein: p < .001). Images produced with 2.0 <, < or = 2.5 ml/kg of contrast medium
presented excellent images of the portal vein, superior to those produced with
1.5 <, < or = 2.0 ml/kg ml (p < 0.05). It is evident from the present data that a
contrast medium volume of more than 120 ml or 2.0 <, < or = 2.5 ml/kg is
sufficient for three-dimensional imaging of hepatic vessels. These images may be
a useful diagnostic tool in patients with hepatic disease.
PMID- 10689886
TI - [Percutaneous mechanical thrombectomy for thrombosed vessels with a hydrolyser
(hydrodynamic thrombectomy catheter): clinical experience].
AB - A hydrodynamic thrombectomy catheter was prospectively evaluated for the
treatment of thrombosed vessels. Seven patients (7 males: age range from 56 to 82
years; mean age: 79 years) presenting with acute or chronic occlusion of
peripheral native arteries (n = 6) and dialysis shunt (n = 1) were treated with
the hydrolyser (Cordis, Johnson and Johnson, Japan). Mean occlusion time was 135
days (range: 2-300 days), and mean thrombus length 16 cm (range: 5-20 cm).
Removal of the thrombus was successful in five patients (71%), regardless of the
length of the thrombus. Mean procedure time was 20 minutes (range: 15-30
minutes). No major complications occurred. Adjunctive thrombolysis was required
for persistence of the residual thrombosed distal vessel in one patient.
Adjunctive balloon angioplasty was performed in two patients (one native vessel
and one dialysis shunt), and stent placement was performed in one patient
(dialysis shunt). In two unsuccessful cases, the hydrolyser could not be advanced
to the distal side because of the solid thrombus. Therefore, thrombolytic therapy
was chosen. However, this therapy failed because the guidewire did not pass
within the thrombus. Surgery was performed in these two patients. We conclude
from this clinical experience that percutaneous thrombectomy with a hydrolyser is
a promising technique for the treatment of thrombosed vessels. Especially in the
acute stage of thrombosed occlusion, percutaneous thrombectomy with a hydrolyser
is superior to thrombectomy with a Fogarty balloon catheter because of its
shorter procedure time and fewer complications.
PMID- 10689887
TI - [Usefulness of selective cerebral angiography by transradial approach].
AB - Transradial angiography has recently emerged as an alternative to the
transfemoral or transbrachial approach, especially for coronary procedures.
However, there have been few studies on cerebral angiography using the
transradial approach. The purpose of this study was to assess the outcomes,
complications, and limitations of selective cerebral angiography via the
transradial approach. Selective cerebral angiography by the right transradial
approach using 100-cm-long 4-F catheters was performed in 83 patients. Using five
types of catheters, the success rates of selective catheterization to the right
vertebral artery, right common carotid artery, left common carotid artery, and
left vertebral artery were 40/44 (91%), 68/68 (100%), 62/62 (100%), and 14/25
(56%), respectively. Puncture failed in one patient, and a guidewire could not be
introduced beyond the radial artery loop in one patient. Radial artery spasm
occurred in one patient, but was relieved immediately after nitroglycerin
injection through the sheath with side holes. Subcutaneous bleeding occurred in
six patients, but no obvious hematomas were noted. Occlusion or stenosis of the
radial artery occurred in five patients, but no ischemic symptoms were observed
in any of the cases. This study suggested that selective cerebral angiography can
be performed safely using the transradial approach.
PMID- 10689888
TI - [Assessment of non-ionic contrast agents in reducing the risk of side effects:
analysis on the basis of voluntary willingness-to-pay measured by the contingent
valuation method].
AB - The benefit of replacing ionic contrast agents with non-ionic ones was assessed
by employing cost-benefit analysis, a method of medical economic analysis. The
benefit derived from replacing ionic with non-ionic contrast agents was assessed
by a questionnaire survey of patients using the willingness-to-pay method based
on the contingent valuation method. This questionnaire survey was conducted on
204 patients in Shimane Medical University Hospital during the period from
October to December 1998. The result of analysis showed that when ionic contrast
agents are replaced with non-ionic ones, patients' willingness-to-pay stands at a
median value of 12,500 yen and a mean value of 17,082 +/- 1,049 yen. These
figures are identical with or larger than the NHI-price differences (12,266
14,234 yen; average 13,287 yen), suggesting that patients think the benefit of
reduced side effects from non-ionic contrast agents has a value that is equal to
or higher than the actual NHI-prices of these agents. Further, analysis of
patient profiles indicated that patients' willingness-to-pay went up with age and
income but decreased when age exceeded 60 years, a finding which also suggests
that the willingness-to-pay amount is closely related to the economic strength of
patients.
PMID- 10689889
TI - [Preliminary study of calculating cerebral arterial blood oxygen saturation using
MRI].
AB - To assess whether cerebral arterial blood oxygen saturation (SaO2) can be
calculated by EPI, we examined the relationship between peripheral SaO2 and T2+
signal intensity (SI) changes in the brain in three normal subjects, using 1.5
Tesla MRI. To decrease SaO2, hypoxia was induced by 100% helium-gas inhalation
(60 sec). SI declined as SaO2 decreased during helium inhalation, while rapid
recovery of SI to the baseline was noted with recovery from hypoxia. The
differential effective transverse relaxation rate was closely correlated with
SaO2 (r > 0.94). Consequently, using MRI, we were able to calculate arterial
SaO2.
PMID- 10689890
TI - [Evaluation of in vitro human blood transparentized using near-infrared light].
AB - We developed a new technique for the in vitro imaging of transparent human blood
and examined the resolution of a test chart in transparent blood. We utilized
mainly three devices: a laser diode (wavelength 833 nm) that served as the light
source, a near-infrared camera, and a fiberscope adapted for the camera. Blood
was collected from a human femoral artery. We observed the images of transparent
blood and the fiberscope image of a target in the blood using the light. These
results indicate that further improvements in this system can be expected and
real-time viewing by angioscope may be realized in vivo.
PMID- 10689891
TI - [Development of DICOM image browser for Macintosh computer].
AB - Although many medical image browsers are available today, most are extremely
expensive. To solve this problem, we developed a Digital Imaging and
Communications in Medicine (DICOM) image browser (Medical Image Browser) for
Macintosh computers. A comparison between this software, Advantage Workstation,
NIH Image, and Graphic Converter suggested that this software is useful for
diagnosis on the Macintosh desktop. This software is available at
wwwl.odn.ne.jp/cak42860.
PMID- 10689892
TI - [Pneumonia in the older people].
PMID- 10689893
TI - [Insulin receptor and aging].
AB - The potential link between aging and insulin signaling has attracted substantial
attention since several decades ago, on the basis of evidence including age
related increase in incidence of insulin resistance, insulin resistance and type
2 diabetes in accelerated aging syndromes and lifespan extension by caloric
restriction in rodents. In addition, the intensive investigations in C. elegans
in the 1990's, which have identified insulin signaling components including daf
2, age-1 and daf-16 as the genes whose mutations lead to lifespan extension, shed
new light on molecular mechanisms underlying aging. As suggested by the genetic
studies in C. elegans, it was recently demonstrated that FKHR, FKHRL1 and AFX,
which are mammalian homologues of daf-16 forkhead transcription factor, function
downstream of insulin signaling and Akt/PKB under cellular conditions. However,
it is an open question whether insulin signaling components, including forkhead
transcription factors, play a critical role in aging and longevity in mammals as
well as in C. elegans. Increasing evidence concerning C. elegans indicates that
augmented resistance to stress, in particular, that to oxidative stress is
involved in lifespan extension by genetic mutations of insulin signaling
components. The intriguing finding that signals from the reproductive system
regulate lifespan by modulating the activities of insulin signal transduction
pathway in C. elegans suggests a possibility of co-evolution of reproduction and
aging. The significance of studies on C. elegans with regard to human aging is
discussed.
PMID- 10689895
TI - [Palliative care].
PMID- 10689894
TI - [Neurological diseases in the elderly].
PMID- 10689896
TI - [Diabetes mellitus in the elderly].
PMID- 10689897
TI - [Happiness and background factors in community-dwelling older persons].
AB - In order to maintain and improve mental health of elderly people living in the
community, a cross sectional survey was conducted to elucidate their happiness
and background factors. The subjects were elderly persons living in the community
who were able to fill in the questionnaire themselves. The study employed the
self-recording questionnaire forms used in Kahoku Longitudinal Aging Study by
Matsubayashi et al. Happiness was assessed using a visual analogue scale. Out of
2,379 elderly persons who were able to fill in the questionnaire by themselves in
2,361 (99.2%) returned the questionnaire sheets. After removing inadequate
responses, analysis was possible for 1,873 (78.7%) (860 men (average age 72.7
years) and 1,013 women (average age 72.8 years). Among those with greater
happiness, the ratio of those living with others (p = 0.0051) was high as well as
those with spouses (p = 0.0240), without a history of hypertension (p = 0.0096)
and apoplexy (p = 0.0039), not receiving medication regularly (p = 0.0039), with
regular habit of walking (p < 0.001), or with work (p < 0.001). As for the
relationship between happiness and various scores, the higher the happiness scale
became, the scores for ADL, information-related function, functional and
emotional support network, healthy condition, appetite condition, sleep
condition, memory condition, family relationships, friendship, economic condition
became significantly higher (p < 0.001, respectively). On multiple regression
analysis using the background factors for happiness as explanatory variables,
factors such as functional support network (p < 0.001), emotional support network
(p = 0.0254), healthy condition (p < 0.001), good memory condition (p = 0.0027),
friendship (p < 0.001), good economic condition (p < 0.001) were significant
independent contributing factors. As for the relation between SDS and happiness,
the more serious the SDS score (higher score) became, the scores for the feeling
of happiness became significantly smaller (p < 0.001). For amelioration of the
happiness of elderly persons living in the community, attempts should be made to
improve the background factors clarified by the present study by efficiently
utilizing health, medical and welfare services.
PMID- 10689898
TI - [Sex differences in subjective well-being and related factors in elderly people
in the community aged 75 and over].
AB - Sex differences in factors related to subjective well-being were evaluated in
people in their late old age by interviewing individuals aged 75 years and over
living in 2 regions of Enzan City, Yamanashi Prefecture. The 17-item revised
"Philadelphia Geriatric Center (PGC) Morale Scale" was used for evaluation of
subjective well-being. Factors related to family status, employment, health
related factors, activities of daily living, and results of physical examinations
were each classified into two or more categories, and PGC Morale Scale points
were compared among the categories for all subjects and separately for males and
females using the Mann-Whitney test and the Kruskal-Wallis test. 1) Although the
mean age of males (80.0 +/- 4.4 years) and females (80.4 +/- 4.3 years) was no
significantly difference, PGC Morale Scale points were significantly higher in
males than in females (p < 0.05), indicating a sex difference in subjective well
being. 2) In elderly females, subjective well-being was related to many factors,
and there was a particularly strong relationship between subjective well-being
and both health related factors and activities of daily living. 3) In elderly
males, the factors related to subjective well-being were fewer than in females,
consisting only of "social opportunities", "hobbies", and "grip strength". Since
factors related to subjective well-being differ between the sexes, these
differences must be taken into account when evaluating subjective QOL of the
elderly.
PMID- 10689899
TI - [Effect of age, gender, and body fat distribution on serum leptin
concentrations].
AB - The aim of this study was to clarify the relationship between serum leptin
concentration and age, gender and body fat distribution. Serum leptin
concentrations were determined 267 subjects (138 men and 129 women), aged 30 to
91. The thicknesses of the preperitoneal fat layer (Pmax) and subcutaneous fat
layer (Smin) in the abdomen were measured by ultrasonography. Fat mass and
percent fat were measured by the bioelectrical impedance analysis method. Women
had higher leptin and leptin/fat mass values than men in all BMI groups (BMI <
20, 20-23.9, 24-25.9, > or = 26). The leptin concentration correlated
significantly with BMI, fat mass, percent fat, waist, hip, waist/hip ratio (W/H),
Pmax, Smin and serum Cr in both men and women. The leptin concentration
correlated significantly with age in men only and P/S in female only. Leptin/fat
mass values significantly correlated with age, fat mass, and percent fat, but not
with BMI, waist, hip, W/H, Pmax, Smin and P/S in men. In women, leptin/fat mass
values significantly correlated with BMI, fat mass, percent fat, waist, hip,
Pmax, Smin and P/S, but not with age or W/H. Multiple regression analysis showed
that fat mass and serum creatinine were significant determinants of the leptin
and leptin/fat mass values both in men and women, but that age was a significant
determinant of these values only in men. These results suggest that the influence
of aging on serum leptin concentration exists only in men.
PMID- 10689900
TI - [A case of elderly-onset systemic lupus erythematosus (SLE) complicated with
severe liver dysfunction and pancytopenia due to myelofibrosis].
AB - A 67-year-old woman was admitted to our hospital with a fever. She had been
experiencing arthralgia for about one month. On admission, she had a fever of
38.5 degrees C, was anemic and was experiencing tenderness in the joints of both
hands, elbows and feet. Laboratory data revealed proteinuria, urinary cylinders,
pancytopenia (WBC 900/mm3, Hb 9.5 g/dl, Plt 7.8 x 10(4)/mm3), liver dysfunction
(GOT 414 IU/l, GPT 140 IU/l), and hyper-gamma globulinemia. Antibiotics and
granulocyte-colony stimulating factor were administered intravenously. Bone
marrow aspiration was unsuccessful, but a bone marrow biopsy revealed bone marrow
fibrosis. Immunological examinations were positive for antinuclear antibodies,
anti-deoxyribonucleic acid (DNA) antibodies, anti-double stranded anti- DNA
antibodies, as well as a decreased level of serum complement and an increased
level of serum immune complexes. Tests for viral antigens and antibodies known to
cause hepatitis were negative. Based on these findings, a diagnosis of SLE
accompanied by liver dysfunction and bone marrow fibrosis was made. Steroid pulse
therapy was initiated, but her liver function deteriorated on the first day of
steroid therapy, and she died three days later. SLE accompanied by myelofibrosis
is extremely rare, and only 17 and cases have been reported to date. Among these
reports, the present case is the second oldest subject and the first SLE patient
to suffer from both myelofibrosis and severe liver dysfunction.
PMID- 10689901
TI - [Interstitial pneumonitis associated with Sweet's syndrome in the elderly].
AB - Sweet's syndrome occurring during the course of interstitial pneumonitis in a 70
year-old woman was encountered. She was admitted because of dyspnea on exercise,
dry cough and interstitial shadow on chest x-ray. Lung biopsy, together with
other findings confirmed interstitial pneumonitis. Five days after admission,
genital ulcer and aphtha on the oral mucosa were detected and exudative erythema
appeared on her right shoulder, chest and back. Histological examination of the
skin lesions demonstrated numerous nutrophilic infiltration in the upper dermis,
indicating Sweet's syndrome. The skin eruption rapidly disappeared on treatment
with colchicine. Although six months after admission interstitial pneumonitis
caused respiratory failure, treatment with prednisolone and cyclophosphamide was
effective. Serological and immunological tests demonstrated hyper
gammaglobulinemia and positive reaction for anti SS-A antibody. Pathological
examination of the lip revealed numerous lymphocyte infiltrates around the duct
of the minor salivary gland, suggesting Sjogren's syndrome as the background
disease of Sweet's syndrome and interstitial pneumonitis. This evidence
indicating that even in elderly patients, skin lesions of Sweet's syndrome may
reveal the background disease.
PMID- 10689902
TI - [An extremely elderly patient with choledocholithiasis and many complications].
AB - It was very difficult to treat a 90-year-old woman for choledocholithiasis with
acute obstructive suppurative cholangitis, gallbladder perforation, and a pool of
bile in the right perirenal spase. Extracorporeal shockwave lithotripsy (ESWL)
was performed after emergency percutaneous transhepatic biliary drainage (PTBD),
but we could not perform lithotripsy successfully because of large and hard
stones. Although Endoscopic sphincterotomy (EST) was performed using an ultratome
by rendezvous method. Lithotripsy was finally successful, after three times
endoscopic mechanical lithotripsy (EML) and procedure using an endotriptor for
basket impaction. It is very important in advanced aged patients that endoscopic
treatment should be performed step by step.
PMID- 10689903
TI - [A case of medial medullary infarction without Dejerine syndrome].
AB - A 67-year-old man with right hemiparesis and dysarthria was admitted with right
hemiparesis involving the face, hyperpathia, numbness and pain of the right body
and limb except the face, and had hyperreflexia and pathological reflex in the
right limb. Brain MRI on the day after admission disclosed no lesion which might
explain the symptoms. Short latency somatosensory evoked potential showed a low
amplitude after P14 when the right side was stimulated. Cerebral angiography
revealed occlusion of the left vertebral artery. Brain MRI on the 18th hospital
day disclosed left medial medullary infarction, so we diagnosed medial medullary
syndrome. This case was hard to diagnose, because of the atypical features and
the absence of an abnormal lesion on the initial MRI.
PMID- 10689904
TI - [Otolaryngological Clinic at the Medical Academy in Poznan in 1979-1999].
PMID- 10689905
TI - [Neck reoperations in patients with laryngeal, lingual and tonsillar neoplasms].
AB - One of the most common reasons of failure in head and neck cancer treatment are
metastases in regional lymph nodes. Preoperative assessment of the neck lymphatic
system is an important task, but even more crucial goal is to monitor the
patients after initial operation or combined treatment. The frequency of nodal
recurrences ranged from 9% to 23%. It constitute nearly 50% of all treatment
failures in larynx, tongue and tonsil malignancies. There are different methods
of therapy in nodal recurrence treatment, but the most recommended, easily
accessible and widely used is surgery. The group of 2134 patients (1580--larynx
cancer, 286--tongue and floor of mouth cancer, 268--tonsil cancer) treated
between 1987-1997 were operated in ENT Dept. of K. Marcinkowski University of
Medical Sciences in Poznan. In 269 patients were detected the nodal recurrence.
In 149 cases the recurrence was homolateral, in 48 heterolateral, in 71 patients
the neck was not previously treated. 152 patients were irradiated on the neck
fields just after primary surgery. The rate of recurrences was 12.6%. Authors
analysed and compared the percentage of recurrences for different primary
lesions: larynx, tongue and tonsil neoplasms. The period of time from the last
control examination to the moment of recurrence detection, its frequency on
particular nodal levels, number of recurrences and trends between years 1992-1997
were assessed. 208 patients who developed nodal recurrence had surgical salvage,
59 patients were not qualified to surgery because of the lesion extension. Neck
re-operations were divided into 3 main types: selective, modified radical and
radical neck dissection. The frequency of particular neck dissection types,
curative rates and difficulties of performing the salvage surgery were discussed.
PMID- 10689906
TI - [20-year-long experience in the large-scale fronto-lateral laryngectomy with a
simultaneous reconstruction by muco-cartilagenous nasal septum flap: results of
460 cases].
AB - The late results of the larynx reconstruction by means of the mucoseptal nasal
graft after an enlarged fronto-lateral laryngectomy were described. The analysis
of 460 patients showed a satisfying larynx lumen in almost all cases. In 21 cases
due to the neoplasm recurrence a total laryngectomy were performed. The voice
after surgery was socially good, and the wide larynx lumen was obtained.
PMID- 10689907
TI - [Chromosome damage in the course of laryngeal squamous cell carcinoma].
AB - The aim of the article is a review of own cytogenic studies on laryngeal cancer
confronted with the literature data. Spontaneous and bleomycin-induced chromosome
instability was analysed in peripheral blood lymphocytes in relation to genetic
risk of cancer incidence and progression. Comparative genome hybridization (CGH)
was applied to demonstrate gains and losses of DNA copy number in tumour and non
tumour laryngeal mucosa. The profiles of imbalances of DNA copy number were shown
to differ between metastazing and non-metastazing tumours. Preliminary data
indicate a frequent loss of Y chromosome in tumour cells. The loss of
heterozygosity at chromosome p53 locus (17p) has been shown to be more frequent
than at chromosome locus coding 16 gene (9p). Altogether, the experiments have
proven that a dynamics of chromosome aberrations is highest at the stage of
metastasis.
PMID- 10689908
TI - [Adenoid cystic carcinomas of the head and neck (cylindromas)].
AB - In the years 1958-1997 111 patients with adenoid cystic carcinoma in the head and
neck of different localization were treated at the Department of Otolaryngology-
Head and Neck Surgery. Majority of the tumors originated of the major salivary
glands, mainly in the parotid gland (47 cases). The most common location among
the tumor of the minor salivary glands was the palate (14 persons). The tumors
arising from other mucous glands, most frequently has located in the maxillo
ethmoideal complex (20 cases). The authors stress diagnostic difficulties, the
necessity of a proper selection of the surgical method and postoperative
radiotherapy, describing the treatment results in the patients. Radial surgical
procedure of the adenoid cyctic carcinoma yelds optimal local control and
survival rates.
PMID- 10689909
TI - [Pleomorphic adenomas in the materials of the Department of Otolaryngology of the
Academy of Medical Sciences in Poznan].
AB - In the years 1958-1997 were surgically treated in the Department of
Otolaryngology Karol Marcinkowski University of Medical Sciences in Poznan 365
patients with pleomorphic adenomas. Majority of the tumors originated of the
major salivary glands was parotid gland (273 cases). The given materials confirms
the viewpoint that enucleation in the pleomorphic adenomas of the parotid
salivary gland--based on total removal of the tumor together with the capsule and
pouch constitute a completely sure surgical procedure.
PMID- 10689910
TI - [Diagnostic difficulties in cases of laryngeal cancer].
AB - The span of time between the appearance of the first symptoms of larynx cancer
and the moment it is diagnosed in Poland amounts to approximately 6 months. It is
the result primarily of the fact that patients tend to consult a doctor late
after the symptoms show as they underestimate them due to their lack of knowledge
concerning their nature. In some cases the diagnosis may be difficult to give
even for a specialist. The paper presents the cases of three patients with an
unusual course of larynx cancer.
PMID- 10689911
TI - [Otitis media with effusion].
AB - The authors present monographic data as regards causes, epidemiology,
patomechanism and treatment of otitis media with effusion. The attention is paid
to connections between this pathology and acute, recurrent otitis media and
chronic eustachian tube insufficiency. The authors underline occult onset,
asymptomatic and chronic character of this disease, irreversible consequences and
hearing impairment. Among treatment methods the most effective seemed to be the
surgery one: adenotomy with simultaneous tympanostomy. The authors give the
schedule of management of otitis media with effusion and indications to
ventilation tube insertion.
PMID- 10689912
TI - [Critical evaluation of the audiological test results in children].
AB - Factors influencing results of objective hearing examination in children, i.e.
auditory evoked potentials, based on own experiences are presented. "Cross-check"
principle as well as observation of dynamic changes concerning development of
communicative process should be taken into the consideration.
PMID- 10689914
TI - [Phoniatric interpretation of evaluation principles in professional voice
disorders].
AB - The critical assessment of the existing regulations of professional voice
evaluation are presented. The necessity of the use of essential phoniatric
principles is stressed in order to make respective legal decision more realistic
and responsible.
PMID- 10689913
TI - [Hearing loss, disorders of sound localization with the preservation ofsmell and
taste in diabetics].
AB - Diabetes is often complicated by serious medical conditions which could be
related to the development of auditory system and cranial nerves lesions,
disorder of sound localisation and decreased olfactory and taste ability. Cranial
nerve palsies in diabetes are considered as an integral part of the main disease.
Twenty nine children with diabetes and non-diabetics control group, without a
history of exposure to noise, ototoxic drugs, or ear disease aged 4-19 years old
were examined. Hearing impairment may be present in children with disease
duration above 3-5 years and in children with other complications. Sound
localisation tests were performed by the method of Zakrzewski from a free
auditory field, measuring the angle of directional hearing acuity in 35 diabetics
age from 16 to 78 years. Longer duration of diabetes was associated with higher
directional hearing acuity. Higher hearing loss was observed with higher
directional values in diabetics. The authors investigated smell and taste in 35
diabetics. All patients were treated with insulin. Impairment value of smell
identification thresholds was much more frequent than impairment of smell
perception. In no case raised threshold of taste perception.
PMID- 10689915
TI - [Phoniatric remarks on microsurgery of vocal cords].
AB - Own experience in microsurgery of vocal folds are presented. The necessity and
importance of photographic and acoustic documentation (MDVP) as well as
phoniatric pre- and postoperative rehabilitation are stressed.
PMID- 10689916
TI - [The electrophysiological examination of hearing with some metabolic disorders in
children].
AB - Electrophysiological examinations of hearing (ABR, SP) in 60 children with
insulin-dependent diabetes mellitus and 39 children with obesitas simplex were
done. In both groups with normal hearing threshold in pure tone audiometry
disturbances in intrastem conduction were noticed.
PMID- 10689917
TI - [Electrophysiological hearing examination in children and teenagers with insulin
dependent diabetes mellitus].
AB - In 60 children and youngsters aged 14-19 (average 16.5) with insulin dependent
diabetes (lasting on average 5.5 years) and normal hearing in pure tone
audiometry electrophysiological examinations (ABR, SP) were performed; 48% of the
cases revealed changes in latencies of I, III, V waves, especially as an
elongation of I and V waves. In the peripheral interlatencie (III-I; V-I)
shortening and in V-III elongation were observed. In SP examination most often
shortening of N1 (67%) and P2 (87%) were found. Statistically significant
dependence of latency changes on the state of metabolic balance was stated. It
was not found referring to the duration of diabetes, age and gender of the
patients.
PMID- 10689918
TI - [The use of fibrin glue in otorhinolaryngology].
AB - Biochemical and physiological principles of biological sealing are presented.
Various methods of application of biological seal and indications for its use in
otorhinolaryngology are discussed.
PMID- 10689919
TI - [The treatment of tracheal stenosis in Wegener's granulomatosis by laser
surgery].
AB - A case of Wegener's disease is described. In eight years of remission a patient,
treated with cyclophosphamid and steroids demonstrated sterosis of the trachea
and upper way obstruction. We have performed carbon dioxide laser photoresection
of granulotion mucosis and scars with an excellent results.
PMID- 10689920
TI - [Tracheoesophageal fistula after the removal of esophageal foreign body].
AB - A case of 18 years old male with tracheoesophageal fistula as a result of
esophageal foreign body (chestnut) is described. Foreign body was removed using
esophagoscopy. Bronchofiberoscopy performed because of difficulties with
swallowing and frequent airway infections revealed tracheoesophageal fistula.
Fistula was closed from intratracheal access. Symptoms of dysfagia disappeared
after surgery.
PMID- 10689921
TI - [Pleomorphic adenoma of rare localization in the nose].
AB - Pleomorphic adenoma localised in nasal cavity is extremely rare. Authors
described a case of mixed salivary gland tumor in the lateral wall of nasal
cavity. We are presented, on the base of our experience and literature data,
pathogenesis, clinical course and treatment of this tumors situated in atypical
places.
PMID- 10689922
TI - [Amyloidosis of the larynx].
AB - The paper presents three cases of localised amyloidosis of the larynx. The study
was focused on case histories, findings of larynx examination and method of
treatment was discussed. Amyloidosis is a disease characterised by gathering of
amyloid deposits in extracellular space. The amyloid fibres consist of different
kinds of proteins which have the ability of forming laminae. This disease may be
secondary to numerous general processes in which amyloid proteins forms.
Etiopathogenesis of this disease has not been explained yet. In the following
paper the latest theories and classification of amyloidosis are presented.
PMID- 10689923
TI - [Heterotopic salivary gland imitating laryngeal cyst].
AB - Patient aged 56 with heterotropic salivary gland in vestibule of the larynx was
described. Localization of heterotropic salivary tissue in the larynx is very
rare.
PMID- 10689924
TI - [Thoracic duct cyst].
AB - Patient aged 48 with the cyst of the cervical part of thoracic duct was
described. Cyst appeared as the result of inflammation. Histopathological
examination excluded the cystic lymphangioma.
PMID- 10689925
TI - [Sarcoidosis presenting as isolated nodules of the parotid and submandibular
glands].
AB - The authors documented the case of healthy, 50 year old women with a sarcoid
lesions of the parotid and submandibular gland without any other manifestations
of the disease. The presence of noncaseating granulomas in salivary tissue is a
specific feature of sarcoidosis. Primary involvement of the intraglandular lymph
nodes with a secondary involvement of the salivary gland parenchyma was detected.
Etiopathogenesis, diagnostics and clinical features of sarcoidosis were
presented.
PMID- 10689926
TI - [Craniofacial bone dysplasia].
AB - The case of fibrous dysplasia localised in the maxilla in 7 years old girl was
described. Attention was paid to etiology, symptoms and treatment. The
differential diagnosis was discussed. The diagnosis was wet set on the bases of
clinical examination, X-ray, scyntygraphy and histological examination.
PMID- 10689927
TI - [Mixed hearing loss in the case of Goldenhar-Gorlin syndrome].
AB - The authors describe a rare case of Goldenhar-Gorlin Syndrome, also called
oculoauriculovertebral dysplasia (OAV) or hemifacial microsomia. Goldenhar's
syndrome was accompanied by hearing loss caused by deformity of the auricle and
atresia of the external auditory canal.
PMID- 10689928
TI - [Nitric oxide: an important regulator of ciliary epithelial function of the upper
respiratory tract].
AB - Importance of nitric oxide in regulation of ciliary activity and secretion of the
mucin was discussed. Advantage of measurement of nasal nitric oxide concentration
in course of maxillary sinuses diseases was emphasized.
PMID- 10689929
TI - [The clinical features of cervical spondylosis with boule musculaire].
AB - To clarify the pathophysiology of boule musculaire associated with cervical
spondylosis, we investigated the 13 patients (11 males and 2 females) with
cervical radiculopathy caused by cervical spondylosis. None of the patients had
any subjective symptoms such as sensory disturbance, weakness in the boule
musculaire, and muscle atrophy of the insurround region near the boule
musculaire. Among 21 tendon reflexes of the biceps muscle of the arm, 9 were
normal, 8 were decreased and 4 were increased. Among the 13 patients there was
only 2 clinical cases of cervical myelopathy. MRI obtained from 3 patients
demonstrated a compressed cervical cord. Electromyography obtained from 7
patients demonstrated mild neurogenic changes such as polyphasic or prolonged
motor unit potential (MUP) in the boule musculaire and in the atrophic regions.
However, there was no giant MUP, fasciculation, fibrillation, nor positive sharp
waves suggesting denervating lesions below the anterior horn in any patient. It
was considered that the boule musculaire observed in cervical spondylosis
gradually developed from a relatively mild disturbance of the ventral root.
Moreover, the boule musculaire developed more often in the male patients, and
predominantly on the right side. Cervical spondylosis accompanying boule
musculaire may be a prodromal stage or a mild type of cervical spondylotic
amyotrophy.
PMID- 10689930
TI - [Coagulation and fibrinolytic activation in lacunar infarct patients].
AB - Lacunar infarcts are related to occlusion of penetrating arteries. Lipohyalinosis
affects the smaller arteries 40-200 microns in diameter, and atherosclerosis
involves larger arteries 200-850 microns in diameter. We hypothesized that the
processes of thrombus formation might be different among these two kinds of
lacuner infarcts, including those caused by lipohyalinosis and atherosclerosis.
We studied acute coagulation and fibrinolytic activation in lacunar infarct
patients which were divided into two groups according to their size: smaller
lacunar group and larger lacunar group. Then we divided lacunar infarct patients
into two groups in terms of the progression of motor deficits: those who showed
the progression and those did not. And coagulation and fibrinolytic activation
were compared each other. One hundred and twenty four patients were enrolled in
this study, including 34 control subjects, 39 patients with smaller lacune (3 mm
10 mm in diameter), 28 patients with large lacune (10 mm-20 mm), and 23 patients
with atherothrombotic infarcts confirmed by angiography. The levels of TAT
activity in large lacune and atherothrombotic infarcts were significantly higher
than those in control subjects (p = 0.009, p < 0.0001, respectively), whereas
those in small lacune were not. Also, the levels of D-dimer activity in large
lacune and atherothrombotic infarcts were significantly higher than those in
control subjects (p = 0.0003, p < 0.0001, respectively), whereas those in small
lacune were not. The progression of motor deficits were more frequently
recognized in large lacune than in small lacune: three patients out of 39 small
lacune patients and 22 patients out of 28 large lacune patients (difference was
significant, p = 0.001). The level of TAT activity in patients who showed
progression of motor deficits was significantly higher than that in those who did
not (p = 0.0002), whereas the difference of the levels of D-dimer activity in two
groups did not reach significant differencial levels. The process of thrombin and
fibrin formation in large lacunar infarcts which are related to microatheroma and
atheroscrelosis appears to be different from that in small lacunar infarcts.
Antiplatelet and anticoagulation therapy should be tailored to large lacunar
infarct patients.
PMID- 10689931
TI - [Effect of prednisolone on apoptosis and cellular infiltration in mdx mouse
muscle].
AB - Myonuclear apoptosis might precede the muscular degeneration of Duchenne muscular
dystrophy. We examined influence of prednisolone (PSL) on apoptosis in the
skeletal muscle of mdx mouse. Amount of apoptotic nuclei of the tibial anterior
or quadriceps muscle was assessed by Tdt-mediated dUTP biotin nick end-labeling
(TUNEL) method. When nuclei were classed into myonuclei and interstitial ones,
apoptotic nuclei were observed mainly in the latter. In comparison between 7 and
33 week-old mice, interstitial apoptosis increased with age in both control and
PSL group. Treatment with PSL decreased number of interstitial apoptotic nuclei.
To the contrary, apoptotic myonuclei were increased with PSL treatment. Treatment
with PSL significantly reduced focal accumulation of infiltrating mononuclear
cells, possibly contributing to the suppression of muscle degeneration.
Relationship between decrease of interstitial apoptosis and reduced cellular
infiltration was unclear yet. Present study showed that PSL differently affected
apoptosis between muscle cells and their interstitium.
PMID- 10689932
TI - [Diagnosis of inflammatory myopathy; usefulness of 99mTc MDP scintigraphy and
muscle MRI for determination of affected sites].
AB - We studied the effectiveness of 99mTc-MDP (methylendiphosphate) scintigraphy in
imaging inflammatory myopathy. The three subjects including 1 male and 2 female
patients had high creatine kinase (CK) levels and proximal dominant muscle
weakness. In whole body muscle surveillance by 99mTc-MDP scintigraphy, abnormal
99mTc-MDP accumulation was found in the extremities of all patients. The sites
with high 99mTc-MDP accumulation showed high intensity on T2 weighted MR imaging,
suggesting an inflammatory process. Muscle biopsy was performed on two patients
from the muscles with the abnormal MRI findings, which showed the diagnostic
finding of inflammatory changes. Because muscle involvement in inflammatory
myopathy differs from muscle to muscle, it is sometimes difficult to choose
appropriate muscle biopsy sites for diagnostic purposes. Affected muscles are
more easily identified by using 99mTc-MDP muscle scintigraphy and muscle MRI,
therefore, a correct diagnosis and choice of biopsy site can be made. 99mTc-PYP
scintigraphy is permitted for use in myocardial infarction alone and 111In
antimyosin scintigraphy is not available in Japan. Therefore, we recommend 99mTc
MDP scintigraphy for diagnosis of inflammatory myopathy and for determination of
muscle biopsy sites.
PMID- 10689933
TI - [An autopsy case of amyotrophic lateral sclerosis/parkinsonism-dementia complex
with family history and living history in the Kii Peninsula focus].
AB - The patient was 68 year-old woman with an 8-year history of parkinsonism which
was followed by psychiatric symptoms and neurogenic amyotrophy 5 years after the
onset. She had a family history of parkinsonism associated with dementia in all
of her three siblings. They grew up in Hobara village, a focus of amyotrophic
lateral sclerosis (ALS) in the Kii Peninsula of Japan, in their childhood. Their
parents were neither consanguineous nor natives of the Kii Peninsula. The brain
weight was 1,040 g, and there were mild frontal lobe atrophy, moderate atrophy of
pes hippocampi, decoloration of the substantia nigra and locus ceruleus, and
anterior spinal root atrophy. The microscopic examinations revealed degeneration
of CA 1 portion of the hippocampus to parahippocampal gyrus, substantia nigra,
locus ceruleus and spinal anterior horn with Bunina body. The spinal pyramidal
tracts also degenerated mildly. The neurofibrillary tangles (NFT) were observed
in the cerebral cortex, especially in the cortices through hippocampus to lateral
occipitotemporal gyri, basal nucleus of Meynert, basal ganglia, thalamus,
substantia nigra and widespread regions of the central nervous system through the
brainstem to the spinal cord including the nucleus of Onufrowicz. In spite of a
few amount of the senile plaques in the cerebral cortex and Lewy bodies in the
substantia nigra and locus ceruleus, abundant NFT distributed mainly in the third
layer of the cerebral cortex, which is the characteristic finding of amyotrophic
lateral sclerosis/Parkinsonism-dementia Complex (ALS/PDC) in the island of Guam.
Thus this was verified ALS/PDC case outside the Guam island. The high incidence
of neurological disease in her siblings and their history of living in the focus
region in childhood suggest the genetic factor of ALS/PDC which is sensitive to
certain environmental agents in the early stage of the life.
PMID- 10689934
TI - [The cerebral peduncle lesion in multiple system atrophy].
AB - Atrophy of the cerebral peduncle and the pons can be seen on radiologic
examination in patients of multiple system atrophy. This radiologic finding is
one of the landmarks for the diagnosis of multiple system atrophy, but its
detailed pathological background has not been thoroughly assessed. To clarify the
pathological features of the cerebral peduncle lesion, samples from 28 autopsied
cases (male 16, female 12; age 50-76 yr) were semiquantitatively examined after
staining by HE, KB, Holzer, GFAP, Bodian and Gallyas methods. Atrophy of the
cerebral peduncle was symmetric in most cases and resulted from the loss of small
sized nerve fibers. The glial cytoplasmic inclusion (GCI) in the cerebral
peduncle increased significantly in severe atrophic cases compared with mild
atrophic cases. However, in the most severe atrophic cases, in which this tissue
was severely damaged, the GCI was decreased. The atrophy of the cerebral peduncle
correlated significantly with the degree of degeneration in the olivo-ponto
cerebellar system and tended to correlate with a decrease in brain weight. The
duration of disease is significantly longer in severe atrophic cases compared
with mild atrophic cases.
PMID- 10689935
TI - [A case with HTLV-I associated myelopathy (HAM) accompanied by primary biliary
cirrhosis (PBC) and autoimmune hepatitis (AIH)].
AB - We reported a 60-year-old female patient with HTLV-I associated myelopathy (HAM)
accompanied by primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH).
The diagnosis of PBC and AIH was confirmed by liver biopsy. HAM is considered to
be mediated by cellular immune mechanisms, while humoral immune mechanisms may
play a predominant role in the development of PBC and AIH. Flowcytometric
analysis of lymphocyte subset of peripheral blood was within normal limits. We
then collected CD4 positive cells from the patient. These cells expressed T
helper 2 (Th 2) cytokine mRNA such as IL-4 and IL-10, but did not express Th 1
cytokines, indicating the predominance of Th 2 in this patient. This case
suggested the possibility that disease associated Th 2 might develop in the
course of Th1-mediated disease like HAM.
PMID- 10689936
TI - [A family with probable autosomal dominant bulbospinal muscular atrophy with
gynecomastia].
AB - We reported a 52-year-old man and his family with bulbospinal muscle atrophy
(BSMA) and gynecomastia. The propositus presented with the clinical picture of
late onset progressive bulbospinal muscular atrophy including postural tremor,
general hyporeflexia, mild maturity onset diabetes, gynecomastia and sexual
impotence. One of his brother and his two sons had gynecomastia. His elder son
had ocular movement abnormality, associated movement of facial muscle and finger
tremor. One of his brothers showed tongue fasciculation without gynecomastia.
None of members examined had abnormal expansion of CAG repeats in the androgen
receptor gene. We speculate that this family has a new clinical entity
characterized by bulbospinal muscular atrophy with an autosomal dominant
inheritance.
PMID- 10689937
TI - [A novel splice-site mutation in the STA gene in a Japanese patient with Emery
Dreifuss muscular dystrophy].
AB - Emery-Dreifuss muscular dystrophy (EDMD) is an X-linked recessive or autosomal
dominant progressive muscular dystrophy characterized by progressive muscle
wasting and weakness with scapulo-humero-peroneal distribution, early contracture
and cardiomyopathy with conduction block. The responsible gene for EDMD,
designated as 'STA', has been mapped to Xq 28 and cloned. It encodes a serine
rich protein of 254-amino-acid, called 'emerin', localized in the inner nuclear
rim. We performed genetic analysis of a 23-year-old male clinically diagnosed as
EDMD and found a novel point mutation. Total RNA was extracted from skeletal
muscle and reverse-transcription and polymerase chain reaction amplification was
performed using a set of oligonucleotide primers between 5'-flanking site of exon
1 and exon 4. Our patient gave a smaller PCR product (about 30 bp) than normal
control. The determined cDNA sequence revealed a deletion of 29 bp, spanning
position 164 to 192 in exon 1. To clarify the mutant allele, we performed genomic
DNA sequence. Genomic DNA sequence from the initiation of exon 1 to the upstream
lesion of exon 2 confirmed a novel point mutation G to C, at nucleotide 197 in
the donor splice site of intron 1. This point mutation may interfere with the
correct splicing of the mRNA and cause frameshift, resulted in truncation of
predicted protein by premature stop. We report a novel point mutation G to C, at
nucleotide 197 in the intron 1 of STA gene corresponding the truncation of
predicted protein, which differs from any of the previously reported mutations.
PMID- 10689938
TI - [A case of adult cerebral X-linked adrenoleukodystrophy (X-ALD) accompanying
typical hypertrophic neuropathy with marked onion-bulb formation].
AB - We report a case of adult cerebral X-linked adrenoleukodystrophy (X-ALD). His
illness started with minimally unsteady gait and slight difficulty in speaking at
age 43; then mental deterioration progressed rapidly within two years, which was
the characteristic clinical feature of this case. He had not shown any signs and
symptoms of spastic paraparesis and adrenal dysfunction. Sural nerve biopsy
revealed marked demyelination and moderate loss of nerve fibers, showing typical
hypertrophic neuropathy with marked onion-bulb formation, while trilaminar
inclusions considered as pathognomonic to X-ALD were not detected in our case.
Although onion-bulb formation has sometimes been referred to in the peripheral
nerve specimens from X-ALD patients, such a remarkable onion-bulb formation as
seen in this case is extremely rare. It suggests that severe destruction of
myelin in the peripheral nerve have persisted for a fairly long period without
drawing any attention from medical staff.
PMID- 10689939
TI - [A case of neuroleptic malignant syndrome associated with reversible
leukoencephalopathy].
AB - We report a case of neuroleptic malignant syndrome associated with reversible
leukoencephalopathy. The patient was a 60-year-old woman. Soon after ingesting an
antipsychotic drug, the patient developed neuroleptic symptoms. After hydration
and dantrolene sodium were administered, muscular rigidity gradually improved and
serum levels of CK became normal. On the 7th hospital day, however, she fell into
coma and showed tetraplegia. Although brain CT was normal on admission, diffuse
low density areas were observed on the parieto-occipital cerebral white matter.
The same lesions were observed on T2-weighted MRI. On the 20th hospital day,
after giving her glycerol and adrenocorticosteroid, not only abnormal
neurological findings but also abnormal CT and MRI findings disappeared. There
were only two case reports of leukoencephalopathy with malignant syndrome in the
literature. This is a rare case of reversible leukoencephalopathy with
neuroleptic malignant syndrome due to the antipsychotic drug.
PMID- 10689940
TI - [A case of cerebellar degeneration showing amaurosis fugax due to primary angle
closure glaucoma].
AB - We reported a 76-year-old woman with cerebellar degeneration who had transient
monocular visual loss following the acute attacks of angle-closure glaucoma. The
episodes occurred only at night approximately every ten days. She denied pain or
any other associated symptoms. Ophthalmological examinations including
intraorbital pressure, ocular fundus, visual acuity and visual field showed no
abnormalities between the attacks. Provisional diagnosis on admission was
amaurosis fugax from retinal embolization. After admission, she developed a
typical acute attack of glaucoma accompanied by severe pain in her left eye.
Intraorbital pressures were 12 mmHg in the right eye and 58 mmHg in the left, and
the diagnosis of primary angle-closure glaucoma was made gonioscopically.
Following peripheral iridotomy by laser therapy, her visual acuity recovered and
episodes of visual loss disappeared. In this case, the attacks of glaucoma were
unusually painless, so it is very difficult to distinguish between glaucoma and
amqurosis fugax from retinal embolization. The transient visual loss always
occurred at night, and retrospectively, this characteristic feature might
indicate that these episodes were acute attacks of angle-closure glaucoma.
Glaucoma is one of the diseases that can cause painless amaurosis fugax.
PMID- 10689941
TI - [A Japanese case of Poland-Mobius syndrome].
AB - We herein report a Japanese case of Poland-Mobius syndrome. The patient was a 19
year-old female. She was the product of a full-term forceps delivery. Birth
weight was 2500 g. She had a defect of the right pectoral muscle, and syndactyly
of the right hand. When she was 10 days old, facial diplegia, bilateral abducens
nerve palsy, and bilateral ptosis were also noted. She was admitted to our
hospital at 19 years of age. On physical examination, she had microsyndactyly of
the right hand, and her right pectoralis major muscle was absent. Neurological
examination revealed bilateral abducens nerve paresis, mild impairement of the
upward and adducting movement of both eyes and bilateral facial weakness and
atrophy of the left side of her tongue. Her karyotype was normal. Neither R 1 nor
R 2 response was evoked in the blink reflex on either side. Brain MRI disclosed
thin facial nerves and atrophy of the pons and medulla. Therefore, she was
diagnosed as a case of Poland-Mobius syndrome. In this case, the facial nerves
were considered to be hypoplastic.
PMID- 10689942
TI - [A case of Sweet's syndrome (acute febrile neutrophilic dermatosis) showing
transient jargon aphasia].
AB - A 54-year-old woman visited our emergency service complaining of a severe
language disturbance. She was fluently speaking something but most of the words
were merely meaningless syllables. This jargon state lasted only four hours, then
her abnormal speech rapidly and completely recovered within 24 hours. She had
also suffered from painful oral ulcers, fever and erythema-like eruptions on her
face for about three weeks. Skin biopsy of a facial lesion revealed a dense
infiltrate of neutrophils in the dermis and minimal features of vasculitis,
which, with other typical clinical findings, led us to the diagnosis of Sweet's
syndrome. Although head CT scans, MRIs, MRA or SPECT could not detect any brain
lesions, a cerebrospinal fluid examination showed a mild pleocytosis of 38/mm3
with 47% polymorphonuclear cells. There have been a few case reports on Sweet's
syndrome accompanying neurologic symptoms, most of which are mild meningitis. We
speculate that the transient aphasia was due to a focal lesion in the central
nervous system attributable to Sweet's syndrome. Sweet's syndrome might bring
inflammatory or ischemic lesions to the cerebrum as Behcet's disease.
PMID- 10689943
TI - [A case of non-Hodgkin lymphoma in the central nervous system, developing during
treatment of galactorrhea amenorrhea syndrome].
AB - We report a 27-year-old woman with a non-Hodgkin lymphoma in the central nervous
system (CNS), showing monoparesis of the right upper extremity during treatment
for the galactorrhea amenorrhea syndrome. The MRI demonstrated an infiltrative
lesion with an obvious gadolinium-enhancement effect, extending from the
pituitary stalk and hypothalamus through the 4th ventricle to the dorsal part of
the medulla and upper cervical spinal cord. Because no tumors were detected in
any other organ in either a physical examination or radiological investigations,
including CT for the chest and abdomen, she was diagnosed as having primary CNS
non-Hodgkin lymphoma (B cell origin) on the basis of an open brain biopsy. After
the irradiation of the whole brain, followed by chemotherapy (methotrexate +
CHOP), the infiltrative tumor disappeared on the MRI with a slight improvement
for monoparesis of the right upper extremity. In this patient, primary CNS
lymphoma might originate around the hypothalamus and infiltrate the medulla,
inducing not only monoparesis of the right upper extremity but the galactorrhea
amenorrhea syndrome.
PMID- 10689944
TI - [Direct Gram staining of blood culture sample enabled the early diagnosis of
brain abscess due to Listeria monocytogenes].
AB - A 58 year old woman had a long history of immunocompromised state. Since age 28
she had multiple endocrine neoplasm type 2A: her thyroid gland and bilateral
adrenal glands were removed because of pheochromocytoma and thyroid medullary
carcinoma. Corticosteroid and levothyroxine were supplemented. At age 57 she was
afflicted with systemic lupus erythematodes and nephrotic syndrome. Prednisolone
therapy was started. Two months later she developed fever, lethergy, headache and
left hemiparesis. MRI revealed multiple ring-enhancing lesions in the right
cerebrum. CSF was negative for microorganisms. Blood culture hemolysed after 24
hours. Direct gram staining of the blood culture sample revealed gram-positive
short rods without spore, suggested listeria. This enabled prompt initiation of
high dose penicillin therapy before the official report of listseria infection.
Neurological abnormality including left hemiparesis disappeared completely within
one month. Enhancement of abscess wall decreased every month, but it persisted
for five months despite continuous intravenous penicillin therapy. Listeria
monocytogenes is well-recognized as an opportunistic pathogen. It requires
prolonged therapy with antibiotics, since it is the intracellular organism.
Monitoring of the brain abscess wall by the enhanced MRI is useful to determine
the completion of therapy. Since listerial contamination is common among raw meat
and unpasteurized milk, immunocompromised patients should be alarmed not to eat
uncooked food products.
PMID- 10689945
TI - [Appropriate method of apheresis in Guillain-Barre syndrome].
PMID- 10689946
TI - [Dementia with Lewy bodies and Parkinson's disease with dementia].
PMID- 10689947
TI - [Helicobacter and malignant diseases of the ventricle].
PMID- 10689948
TI - [Influenza--drug therapy and prevention].
PMID- 10689949
TI - [Use of glucocorticoids in rheumatoid arthritis].
AB - OBJECTIVES: To determine whether short-term (i.e. as recorded within the first
month of therapy), oral low-dose corticosteroids (corresponding to a maximum of
15 mg prednisolone daily) is superior to placebo and nonsteroidal,
antiinflammatory drugs in patients with rheumatoid arthritis. SEARCH STRATEGY:
Medline Silverplatter, The Cochrane Controlled Trials Register, reference lists
and a personal archive. SELECTION CRITERIA: All randomised studies comparing an
oral corticosteroid (not exceeding an equivalent of 15 mg prednisolone daily)
with placebo or a nonsteroidal, antiinflammatory drug were eligible if they
reported clinical outcomes within one month after start of therapy. DATA
COLLECTION AND ANALYSIS: Decisions on which trials to include were made
independently by two observers based on the methods sections of the trials only.
Standardised effect measures were used for the statistical analyses; the random
effects model was used if p < 0.10 for the test of heterogeneity. MAIN RESULTS:
Ten studies, involving 320 patients, were included in the meta-analysis.
Prednisolone had a marked effect over placebo on joint tenderness (standardised
effect size 1.31, 95% confidence interval 0.78 to 1.83), pain (standardised
effect size 1.75, 0.87 to 2.64) and grip strength (standardised effect size 0.41,
0.13 to 0.69). Measured in the original units, the differences were 12 tender
joints (6 to 18) and 22 mmHg (5 to 40) for grip strength. Prednisolone also had a
greater effect than nonsteroidal, antiinflammatory drugs on joint tenderness
(standardised effect size 0.63, 0.11 to 1.16) and pain (standardised effect size
1.25, 0.26 to 2.24), whereas the difference in grip strength was not significant
(standardised effect size 0.31, -0.02 to 0.64). Measured in the original units,
the differences were 9 tender joints (5 to 12) and 12 mmHg (-6 to 31). The risk
of adverse effects, also during moderate- and long-term use, seemed acceptable.
CONCLUSIONS: Prednisolone in low doses (not exceeding 15 mg daily) may be used
intermittently in patients with rheumatoid arthritis, particularly if the disease
cannot be controlled by other means. Since prednisolone is highly effective,
short-term placebo controlled trials studying the clinical effect of low-dose
prednisolone or other oral corticosteroids are no longer necessary.
PMID- 10689950
TI - [Invasive aspergillosis in hematological patients].
AB - An increasing incidence of invasive aspergillosis over the last decades is well
documented in patients with haematological malignancies and is the most
significant fungal infection in patients undergoing bone marrow transplantation
and in aplastic anaemia. The diagnosis is difficult as clinical signs and
symptoms usually are non-specific, but can be supported by frequent radiological
examinations of the chest and sinuses and successive demonstrations of
Aspergillus antigen in serum. The prognosis depends on the course of the
underlying disease. A regeneration of the neutrophil granulocyte number is a
condition for successful treatment. Early antifungal therapy is often necessary
in neutropenic patients with fever and a lung infiltrate that does not remit
following broad spectrum antibacterial treatment. Because of the risk of relapse
after successful treatment these patients should receive prophylactic antifungal
treatment during subsequent neutropenic episodes.
PMID- 10689951
TI - [Prognosis after late versus early nonfatal myocardial infarction].
AB - Many recent studies have identified nonfatal recurrent myocardial infarction
(RNMI) as the most significant predictor for later outcome. Almost all of these
studies have been based on the studies of RNMI in the first year after the index
infarction. The prognosis after late RNMI has not been studied properly. In 3,867
nonselected patients below 76 years of age with an acute myocardial infarction we
studied the prognosis after a first RNMI depending on the year of its occurrence
after the index infarction. Mortality was estimated by the method of Kaplan-Meier
and the differences were evaluated by means of the Tarone-Ware test. Four hundred
and ninety-three (13.6%) patients had a first RNMI in the first, 151 (5.4%) in
the second, 105 (4.2%) in the third, and 71 (3.8%) in the fourth year after the
index infarction (group 1-4). One-year mortality rate after RNMI was 23.7% in the
first group, 24.1% in the second, 17.5% in the third, and 22.8 in the fourth
group. When all the groups were compared with each other no significant
difference was found between the mortality rates (p = 0.12) or Standardised
Mortality Rates. We concluded that late and early RNMIs have almost the same
grave prognosis.
PMID- 10689952
TI - [Detection of cholangiocarcinoma in primary sclerosing cholangitis by positron
emission tomography].
AB - Primary sclerosing cholangitis (PSC) predisposes to cholangiocarcinoma (CC). PET
scanning can assess metabolism in vivo. The glucose analogue [18 F]fluoro-2-deoxy
D-glucose (FDG) accumulates in malignant tumours because of high glucose
metabolism. PET scanning of the liver was performed after intravenous FDG in nine
patients with PSC, six with PSC + CC, and five controls. "Hot spots" with
radioactivity accumulation were seen in each PSC + CC patient, but not in the two
other groups. Values of net metabolic clearance of FDG, K (ml min-1 100 ml-1
tissue), was in CC hot spots 1.59 to 4.17 (median, 2.34; n = 6); in reference
liver tissues of these patients 0.40 to 0.69 (0.49); in PSC 0.23 to 0.53 (0.36);
in controls 0.20 to 0.34 (0.31). The difference between K in CC hot spots and the
other groups was statistically significant (P < 0.001). FDG-PET may detect small
CC tumours and be useful in therapeutic management of PSC.
PMID- 10689953
TI - [The staff's knowledge of patients' social function and needs--in connection with
discharge planning].
AB - The aim of the study was to assess the staff's knowledge about the social
functioning and needs of the patients. A cross-sectional study interviewing 48
staff members using the Camberwell Assessment of Need--CAN was carried out. In
nine of CAN's 26 areas more than 5% of the staff did not know if the patient had
a problem. Among the patients with a problem more than 5% of the staff could not
assess the need for care in four areas. The staff generally had a good knowledge
concerning the patients' need for care. CAN seem to be a relevant instrument for
the purpose of discharge planning.
PMID- 10689954
TI - [Pseudolymphoma and ventricular maltoma in patients with chronic gastritis, ulcer
and Helicobacter pylori infection].
AB - Among 128 patients with malignant B-lymphoproliferative disorders, 19 patients
had long lasting dyspepsia and gastroscopy showed chronic active gastritis or
gastric ulcer. PCR analysis for TCR and IgH clonality in biopsies showed local
involvement of the malignant lymphocyte clone in four patients out of eight
indicating presence of these cells in the inflammatory infiltrate. Weak B-cell
clonality was found in four patients. A close relationship was seen between
lymphocytic clonality and immune response to H. pylori Cag A, and all patients
had parietal cell antibodies. Thus, the malignant clone may participate in the
local inflammatory reaction, and continued local stimulation by H. pylori as well
as parietal cell antigens may lead both to autoimmunity as well as a clonal
development of lymphocytes.
PMID- 10689955
TI - [Invasive aspergillosis in two hematological patients].
AB - We present two cases of invasive aspergillosis in patients with acute myeloid
leukemia. In neutropenic patients with antibiotic resistent fever, without
specific symptoms or signs, invasive aspergillosis should be considered.
Diagnostic approaches such as X-ray/CT-scan of the thorax and sinuses, relevant
cultures and antigen detection should be performed. Due to diagnostic
difficulties and the rapid progression of the infection empirical antifungal
therapy should be given. During subsequent neutropenic episodes prophylactic
antifungal therapy can possibly preempt recurrence.
PMID- 10689956
TI - [Massive gastrointestinal hemorrhage from the jejunum caused by Dieulafoy's
lesion].
AB - A 54-year old woman was admitted to the hospital because of massive
haematochezia. Emergency surgical exploration was performed and by a simple
method the source of bleeding was localized and treated. We discuss one of the
major problems in all GI-bleeding that lies in establishing the diagnosis. With
localization in the small bowel the problem is even bigger because this part of
the bowel isn't examined by conventional endoscopy. This case-story should be a
reminder of the small bowel as a source of bleeding when conventional upper and
lower endoscopy does not reveal the bleeding source.
PMID- 10689957
TI - [Dampness in an electric plug as a cause of electricity failure in an operation
theatre].
AB - Two cases of electricity failure in an operation theatre during open heart
surgery are discussed. The fuse for the patient monitor, ventilator, surgery
instruments and heart lung machine was blown. Short-circuit was established
because of humidity in the plug of the heater for fluid and blood. We recommend
sealed or founded plugs and that anaesthesia equipment should not be used as an
electrical supply for other electronic apparatus.
PMID- 10689958
TI - [Ethnicity and the course of psychosis].
PMID- 10689959
TI - [The difficult medical profession].
PMID- 10689960
TI - [Pagers and breast cancer among female physicians].
PMID- 10689961
TI - [Total synthesis of crassostreaxanthin B directed toward the biomimetic synthesis
of carotenoids].
AB - Marine carotenoids halocynthiaxanthin 2, mytiloxanthin 3 and crassostreaxanthin B
4 have characteristic structures, commonly possessing a monoacetylenic end group.
The cyclopentyl end group of 3 is believed to be formed in nature from the
epoxide end group of 5,6-epoxy carotenoids such as 2 (Chart 1, route a). It is
also conceivable that 4 including a novel tetrasubstituted olefinic end group
arises from epoxy carotenoids by the opening of the C-6-oxygen bond of the
oxirane ring and the subsequent migration of the methyl group at the C-1 position
(route b). We found that treatment of the epoxide 6a having a partial structure
of epoxy carotenoids with Lewis acids gave the cyclopentyl ethyl ketone 9
possessing the same configuration as 3, and the acyclic tetrasubstituted olefinic
methyl ketone 11 including a partial structure of 4 (Chart 2). It supported the
proposed metabolic pathway of 5,6-epoxy carotenoids. Toward the biomimetic
synthesis of 4, we examined the reaction of epoxides having several substituents
at C-6 position with Lewis acids. Among these epoxides, an epoxide 60 was found
to provide a tetrasubstituted compound 61 as a major product. This could be
converted into an aldehyde 73 in 8 steps which was transformed into a compound 75
through the coupling reaction with vinyllithium 63. Then, the first total
synthesis of 4 was accomplished via the double Wittig condensation of 75 with
phosphonium salts 76 and 77.
PMID- 10689962
TI - [Syntheses and properties of conformationally restrained nucleosides and
oligonucleotides analogues].
AB - This review summarizes our efficient syntheses of novel bicyclic nucleoside
analogues, 3'-O,4'-C-methyleneribonucleosides (1) (4-BC type nucleoside
analogue), 2'-O,4'-C-methyleneribonucleosides (2) (5-BC), 3'-amino-3'-deoxy-3'
N,4'-C-methyleneribonucleosides (3) (aza 4-BC), and 3'-azido- and 3'-amino-3'
deoxy-2'-O,4'-C-methyleneribonucleosides (4, 5) (aza 5-BC). From 1H-NMR and X-ray
crystallographic analyses, the 4-BC and aza 4-BC type nucleoside analogues (1, 3)
were found to have a S-conformation predominantly, while the conformations of 5
BC and aza 5-BC type nucleoside analogues (2, 4, 5) were exclusively locked in N
form. The 4-BC and 5-BC type nucleoside analogues (1, 2) were effectively
introduced into oligonucleotides using a DNA synthesizer. Furthermore,
unprecedented hybridizing ability towards complementary RNA and DNA, RNA
selectivity, potent triplex forming ability, and sufficient enzymatic stability
of these modified oligonucleotides were also confirmed. These results should
reveal a promising route to the development of antisense/antigene methodology.
PMID- 10689963
TI - [Total analysis system for tumor promoter microcystins produced by
cyanobacteria].
AB - Microcystins, produced by freshwater cyanobacteria, are cyclic peptide
hepatotoxins and tumor promoters. An outbreak of human poisoning attributed to
microcystins has been reported in Caruaru, Brazil in 1996, where exposure through
renal dialysis led to the death of 50 patients. Although such severe acute
effects on human health seem to be rare, microcystins poses problems to human
health which could result from low-level, chronic exposure to microcystins in
drinking water. It is therefore important to monitor the levels of microcystins
in water reservoirs where cyanobacterial blooms occur. We have developed a total
analysis system for microcystins using GC-MS and LC-MS. This comprises initial
screening of samples to check for the presence of microcystins by detecting 2
methyl-3-methoxy-4-phenylbutyric acid as an ozonolysis product using thermospray
interface LC-MS and electron ionization/GC-MS. If a sample is positive in a
screening test, it will be necessary to follow through with identification and
quantification. Frit-FAB interface LC-MS allowed the rapid identification of
microcystins in cyanobacteria and lake water, and also enabled us to identify
microcystins and their metabolites formed in vivo in mouse liver. Finally, Frit
FAB/LC-MS using selected ion monitoring could be used for quantitative analysis
of microcystins in lake water in the low nanogram range. The total analysis
system proposed in the present study should be applicable to studies of the
metabolism of microcystins, of their detoxification, and those of the
mechanism(s) of the accumulation in the food chain.
PMID- 10689964
TI - [Preparation of chemically modified carbon electrodes by anodization in 1
alkanols and their application to electrochemical analysis].
AB - Anodization of a glassy carbon (GC) in a 1-alkanol in a cycled or constant
potential mode serves as a useful tool for preparing a chemically modified GC
electrode. By this treatment, 1-alkanol molecules are fixed on the GC surface via
ether linkage. As the 1-alkanol in the anodic modification, CH3(CH2)nOH (1: n = 0
7), HO(CH2)nOH (2: n = 1-5), and HO(CH2CH2O)nR (3: n = 1-4, R = H; 4: n = 1-3, R
= CH3) are utilized. The surface of a GC electrode anodized in the 1-alkanol
remarkably reflects the identities of the modifiers. Some of the modified GC
electrodes exhibit surface characteristics useful for electroanalytical
application as follows: (1) the surface of the GC electrode anodized in 3 or 4 is
hydrophilic and resists protein adsorption. An HPLC system equipped with an
electrochemical detector employing the GC plate anodized in triethylene glycol as
a working electrode has proven to provide a useful analytical method for a
protein-containing sample; (2) in the course of anodization of the GC electrode
in 2, the diol molecules are first fixed on the surface via ether linkage with
one of hydroxyl groups, and the remaining terminal hydroxyl groups in some of the
fixed molecules are then oxidized to carboxyl groups. Thus, the GC electrode
anodically modified with 2 has carboxyl groups on the surface, which allow
dopamine to be voltammetrically discriminated from ascorbic acid in a large
excess; (3) when the GC electrode is anodized in triethylene glycol containing
HOCH2CH2SO3Na, carboxyl groups are effectively introduced on the surface. On the
basis of the formation of an amide bond formation through chemical reaction
between the functional groups and amino compounds, electrochemical catalysts such
as 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) and catechol are immobilized on
the surface of the GC electrode. The obtained electrodes shows stable
voltammetric and electrochemically catalytic performance probably because the
catalytic molecules are confined on the electrode surfaces via a hydrophilic
linker instead of a hydrophobic one.
PMID- 10689965
TI - [Molecular design and control of functional expression of ate complexes].
AB - As a new type of zincate, "highly coordinated" zincates, Me3Zn(R)Li2 (R = Me, CN,
SCN) were designed. On the basis of their excellent chemical yields and
chemoselectivities, these species were considered to be differentiated from
ordinary triorganozincates, R3ZnLi. The structures of the newly designed zincates
were discussed on their spectroscopic studies. All results strongly support the
fact that these newly designed zincates are new category of zincate species.
Various dialkylzinc hydride "ate" complexes were also designed and the
reactivities of these zincates toward the carbonyl compounds investigated. The
results clearly reveal that dimethylzinc hydrides are the most powerful and
selective zincate for the reduction of the carbonyl group.
PMID- 10689967
TI - [Studies on the syntheses and reaction of nitrogen-containing heterocyclic
compounds centered the naphthyridines].
AB - 1, X-Naphthyridines (X = 5, 6, and 8) (1-3) were synthesized in a high yield by
the Skraup reactions of 4-, 3-, and 2-aminopyridines with glycerol, in the
presence of ferrous sulfate and boric acid. The improved syntheses were applied
to the syntheses of 1,5-, 1,6-, and 1,8-naphthyridines (4-28),
pyridonaphthyridines (31, 32), benzonaphthyridines (38-42), naphthonaphthyridines
(44, 48, 49, 59). New synthetic methods of naphtho[1,2-b or 2,1
b][1,8]naphthyridine (62, 63), benzo[b][1,8]naphthyridine (41) and
benzo[g]quinoline (67) were developed and their compounds obtained conveniently.
Reissert reaction of 1,6-naphthyridine (2) using triethylbenzylammonium chloride
(TEBA) produced Reissert compounds and ring-opened compounds. Reissert reaction
of 1,7-naphthyridine (29), 4,7- (87), 4,6-phenanthroline (38) gave the Reissert
compounds, and the compounds (2, 38) gave their pseudo bases (79, 90). Reissert
type reactions of benzo[f]quinoline (68), and 1,7-phenanthroline (105) with acyl
chloride and phosphite, gave alpha- and gamma-phosphonate, and 87 produced
alpha,alpha'-(108a-c) and alpha,gamma'-diphosphonates (109a-c). The structure of
108c-1 was determined to be trans-type by an X-ray analysis. Compounds 1-3, 29,
and benzo[f or h]quinoline were treated with dimetyl sulfoxide in the presence of
sodium hydride to give mainly methylated compounds at the position para to the
ring-nitrogen. When benzo[f or h]quinoline N-oxide was treated with
methylsulfinylmethyl carbanion in the usual procedure, a new reaction took place
to produce phenanthrene in an excellent yield. The same reaction of 1,10-, 1,7-,
or 4,7-phenanthroline N-oxides (143-145) resulted in the liberation of the N
oxide group to form benzo[f or h]quinoline, but isoquinoline N-oxide afforded to
benzazepine derivatives (161). Reaction of quinaldine with methylsulfinylmethyl
carbanion gave novel tricyclic compound (121a). The oxidation of 41, 62, and 63
with peroxy acids afforded novel products such as seven-membered 1,4-oxazepine
derivatives.
PMID- 10689966
TI - [A novel synthetic approach of tryptophan-containing cystine peptides by
regioselective disulfide bond-forming reaction using the silyl chloride-sulfoxide
system].
AB - A general scheme for the efficient synthesis of Trp-containing cystine peptide by
the successive treatment with methyltrichlorosilane-diphenylsulfoxide in
trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TFMSA)-thioanisole
in TFA, is described. A disulfide bond-forming reaction by silyl chloride
sulfoxide system is completed within 10-15 min without modifications at sensitive
residues (Tyr, His, Met) in peptide chain, except for a Trp residue. In order to
synthesize a Trp-containing cystine peptide using silyl chloride, the indole
moiety of Trp has to be protected since the chlorination of the indole ring
proceeded predominantly. A formyl group has been the only protecting group
employed for this purpose in practical syntheses of cystine peptides, although it
was clarified that a side reaction derived from the formyl group migration was
inevitable in the synthesis of somatostatin. Firstly, we examined the application
of the following Nin-protecting groups, mesitylene-2-sulfonyl (Mts),
cyclohexyloxycarbonyl (Hoc), and 2,4-dimethylpent-3-yloxycarbonyl(Doc) for an
efficient synthesis of the Trp-containing cystide peptide by the silyl chloride
method. In order to find a feasible scheme of the successive treatment with
CH3SiCl3-PhS(O)Ph/TFA and TFMSA-thianisole in TFA, we synthesized somatostatin
using Trp(Mts), Trp(Hoc) or Trp(Doc) derivative. The Doc group was found to be
the most suitable as an indole protecting group, since the protecting group was
cleaved under mild conditions (4 degrees C, 30 min) via the corresponding Nin
carboxylic acid intermediate. We then applied the above procedure to the
synthesis of endothelin-1 (ET-1), a peptide containing 21-amino acid residues
having a C-terminal Trp residue and two disulfide bonds, by regioselective
disulfide formation. The combination of the silyl chloride method with iodine
oxidation using S-acetamidomethyl (Acm) and S-tBu groups for the regioselective
double disulfide formation was successfully applied to give a highly purified ET
1. These results also show that the Nin-Doc group would be useful for the
efficient syntheses of complex cystine-peptides by the silyl chloride method.
PMID- 10689968
TI - [Drug Compliance Scale. I. Development of the Drug Compliance Scale].
AB - The failure of patients to comply with treatment regimens recommended by their
physicians is a significant clinical problem. Researches on the assessment of
compliance have, however, been precluded by methodological difficulties such as
lack of adequate measures. The purpose of this study was to develop a self
administered questionnaire to evaluate drug compliance. First, questionnaire
containing a 52-items complied by two doctors, a pharmacist and a nurse, was
tested on 81 outpatients, all volunteers, attending the departments of
psychosomatic medicine and internal medicine. Four items were temporarily removed
for later analysis because they directly inquired about drug compliance (drug
compliance items). The other 48 items were analyzed and three factors consisting
of 26 items were further studied: expectation on taking medicine, rejection to
taking medicine and seeking knowledge of drugs. Chronback's alpha coefficients
representing internal consistency of the three factors were sufficiently high
(ranging from .75 to .84). Furthermore, we preformed a simplified pill count to
validate the 4 drug compliance items. There was a weak to moderate correlation
between the result of pill count and each of 4 drug compliance items. A new self
administered questionnaire of 30 items was thus developed and named the Drug
Compliance Scale.
PMID- 10689969
TI - [Drug Compliance Scale. II. Psychological factors affecting drug compliance in
the department of psychosomatic medicine].
AB - The purpose of this study was to investigate psychological factors affecting drug
compliance in the department of psychosomatic medicine. Seventy-four outpatients
were asked to answer a battery of self-administered questionnaire including the
Drug Compliance Scale (DCS) that we had recently developed and other
questionnaire evaluating psychological and vegetative symptoms, self-efficacy and
attributional styles on the promotion of health and personality closely related
to interpersonal relationships. Results of path analysis indicated that
attributional styles and self-efficacy mainly affected three factors of DCS such
as expectation on taking medicine, rejection to taking medicine and seeking
knowledge of drugs, through which they influenced drug compliance, and also
indicated that personality and self-efficacy mainly affected the stability of
mood state, suggesting a further influence on drug compliance.
PMID- 10689970
TI - [Investigation on the marker substances of crude drugs in formulations. II.
Marker substances for the identification of Cistanchis Herba in drinkable
preparations].
AB - There are few reports about marker substances for the identification of
Cistanchis Herba in formulations. First, constituent analysis was performed by
HPLC for screening of a marker substance, using several lots of Cistanchis Herba
and its fluid extract. As a result, two components were clearly detected, which
were thought to be good marker substances and identified to be echinacoside and
acteoside by structural analysis. Stability testing of these two marker
substances in various pH and temperature conditions was carried out, which
suggested that they are stable and suitable enough for the identification.
Therefore, the identification methods of Cistanchis Herba and its fluid extract
in formulations were investigated using five different kinds of commercial
drinkable preparations with authentic standard of echinacoside and acteoside as
marker substances. Consequently, echinacoside and acteoside were clearly detected
in all formulations investigated, using an HPLC-photodiode array detector system.
Echinacoside and acteoside will be successfully used as marker substances for the
identification of Cistanchis Herba and its fluid extract in formulations.
PMID- 10689971
TI - Hundreds of RNs across the country showed that nurses CAN.
PMID- 10689972
TI - Initiating a dialogue with the adolescent patient.
PMID- 10689973
TI - New law eases Medicare interim payment system burden on home health care.
PMID- 10689974
TI - Nurse-midwife empowers inner-city women through birth center [interivew by
Michelle Slattery].
PMID- 10689975
TI - ANA media outreach makes a difference.
PMID- 10689976
TI - TNA "gun safe" campaign unites community with common goal.
PMID- 10689977
TI - The human connection: nurses and their patients.
PMID- 10689978
TI - Protecting the patient by protecting the worker.
PMID- 10689979
TI - Why don't more African Americans go into nursing? One experience.
PMID- 10689980
TI - Providing primary care the NP way.
PMID- 10689981
TI - Holistic nursing: the goal is the whole person.
PMID- 10689982
TI - Workplace violence affects one-third of nurses.
PMID- 10689983
TI - Workplace violence: one nurse's night of fear.
PMID- 10689984
TI - RNs confront causes, consequences of school violence.
PMID- 10689985
TI - Nevada nurses secure patient protections.
PMID- 10689986
TI - Health care community faces year 2000. ANA joins group addressing patient care
concerns.
PMID- 10689987
TI - Perceived ability to manage juvenile chronic arthritis among adolescents and
parents: development of a questionnaire to assess medical issues, exercise, pain,
and social support.
AB - OBJECTIVE: To develop a questionnaire to assess perceived ability to manage
juvenile chronic arthritis (JCA) among adolescents and parents. METHODS: The
questionnaire contained 24 (parents' version) and 23 (adolescents' version)
questions accompanied by visual analog scales in the areas of knowledge, skill,
behavior, attitudes, and self-efficacy. One hundred seven persons participated in
the examination of validity and 25 in the examination of test-retest reliability.
RESULTS: Factor analyses indicated that the questionnaire, now termed the MEPS
(abbreviation for "medical issues, exercise, pain, and social support")
questionnaire, contained 4 underlying dimensions: medical issues, exercise, pain,
and social support, including 9, 4, 7, and 4 questions, respectively. The content
of the questionnaire was judged mainly to be easily understood, relevant, and
exhaustive. Intraclass correlation coefficients for the test-retest reliability
of the questionnaire answers over a week ranged from 0.68 to 0.96 for single
questions. CONCLUSION: The MEPS questionnaire appears to be a valid and reliable
tool for assessing the perceived ability to manage JCA. Whether it is
sufficiently responsive to interventions remains to be investigated.
PMID- 10689988
TI - Isometric strength measurements in children with arthritis: reliability and
relation to function.
AB - OBJECTIVE: To examine the reliability of testing strength in children with
juvenile arthritis (JA), and to determine the relationship between strength and
function. METHODS: Children with JA were tested for grip and pinch strength (n =
32). Isometric force produced by hip abductors and knee extensors was tested with
a hand-held dynamometer (n = 29). Two therapists both performed each of the tests
twice so that intrarater and interrater reliability could be examined. Function
was measured by means of the Childhood Health Assessment Questionnaire (CHAQ) and
performance on a 50-meter run. Reliability was examined with intraclass
correlations (ICC). The relationships of strength and function were determined
with Pearson and Spearman correlations. RESULTS: All measures demonstrated good
intrarater (ICC = 0.92-0.97) and interrater (ICC = 0.80-0.95) reliability. Grip
strength and pinch were correlated with the CHAQ (r = -0.45 and -0.33,
respectively), while hip abduction and knee extension torque were correlated with
rankings on the 50-meter run (rho = -0.34 and -0.38, respectively). CONCLUSION:
Isometric strength can be reliably measured in children with arthritis in a
clinical setting.
PMID- 10689989
TI - Health-related quality of life in ankylosing spondylitis: a survey of 175
patients.
AB - OBJECTIVE: To identify aspects of health-related quality of life that are most
commonly affected in patients with ankylosing spondylitis (AS). METHODS: One
hundred seventy-five participants in a longitudinal study of health status in AS
completed a cross-sectional survey that asked them to rate the presence and
importance of problems in 23 aspects of quality of life, including symptoms,
disability, mood, relations with others, and concerns about treatments and the
future. Participants also completed the Medical Outcomes Study Short Form 36
Health Survey (SF-36). RESULTS: The mean age of the participants was 51.1 years,
and the mean duration of AS was 23.7 years; 119 (68%) were men. The most
prevalent quality of life concerns included stiffness (90.2%), pain (83.1%),
fatigue (62.4%), poor sleep (54.1%), concerns about appearance (50.6%), worry
about the future (50.3%), and medication side effects (41%). Compared with those
who had some college education, participants with 12 years of education or less
were 2 to 4 times more likely to have problems or concerns with medication side
effects, mobility, housework and self-care tasks, coping with illness, anxiety,
payment for treatment, and relationships with spouses, family, and friends. Mean
scores on the 8 domains of the SF-36 (range 0-100; higher scores indicate better
function) ranged from 49 (energy/fatigue) to 77 (role limitations due to
emotional problems). Patients with 12 years of education or less had
significantly lower scores than those with some college on all domains except
general health. CONCLUSIONS: In addition to pain and stiffness, fatigue and sleep
problems are important concerns in patients with AS, while few reported problems
with mood or social relationships. Less educated patients had lower quality of
life in many different aspects.
PMID- 10689990
TI - Systemic lupus erythematosus in three ethnic groups. IV. Factors associated with
self-reported functional outcome in a large cohort study. LUMINA Study Group.
Lupus in Minority Populations, Nature versus Nurture.
AB - OBJECTIVE: To identify features of systemic lupus erythematosus (SLE) associated
with poor functional outcome as measured by the 36-item Medical Outcomes Study
Short Form 36 Health Survey (SF-36). METHODS: Two hundred twenty-four patients
with early SLE (70 Hispanic, 83 African American, and 71 white) enrolled in a
longitudinal study of outcomes were evaluated at study entry. The 8 composite
scales and 2 summary measures (physical and mental) of the SF-36 were the
dependent variables. Independent variables--1) sociodemographic, 2) clinical
features, 3) immunologic, 4) global scores, and 5) behavioral/cultural--were
examined for each of the scales and summary measures and for each ethnic group.
Significant variables in these analyses were then used to construct models to
determine their association with each of the scales and the 2 summary measures
for the entire population and the 3 ethnic groups. RESULTS: Self-reported
physical and mental functioning were most consistently associated with abnormal
illness-related behaviors, helplessness, fatigue, and pain at study entry.
Helplessness was more strongly associated with functioning in the Hispanics than
in the African American or white patients. Pain was strongly associated with
physical but not mental health. The models were quite robust, accounting for 41%
to 68% of the variance for the two summary measures. CONCLUSION: Patients'
attitudes toward their disease, fatigue, and pain have greater impact on self
perceived functional levels, as measured by the SF-36, than do more objective
measures of disease activity and damage such as the presence of specific
autoantibodies and/or the occurrence of specific organ involvement. Interventions
designed to improve outcome may need to include ethnic-specific as well as
general strategies.
PMID- 10689991
TI - Systemic lupus erythematosus in three ethnic groups. V. Acculturation, health
related attitudes and behaviors, and disease activity in Hispanic patients from
the LUMINA cohort. LUMINA Study Group. Lupus in Minority Populations, Nature
versus Nurture.
AB - OBJECTIVE: To assess the relationship between acculturation and clinical,
socioeconomic-demographic, and behavioral/psychosocial features in Hispanic
patients with systemic lupus erythematosus (SLE) from the LUMINA (Lupus in
Minority Populations, Nature versus Nurture) cohort. METHODS: An empirically
derived questionnaire was administered to 67 Mexican American SLE patients
participating in a longitudinal study of outcome. This questionnaire inquired
about place of birth, upbringing and length of stay in the United States,
language (proficiency, usage, and preferences; English/bilingual versus Spanish),
type of neighborhood, self-identity, and social interactions. Responses to this
questionnaire and an informal interaction with a single bilingual, bicultural
Mexican American research assistant were used to generate a score on a 10-cm
anchored visual analog scale (VAS) (0 = no acculturation and 10 = maximum
acculturation). The responses to the questionnaire were then quantified and
scored by a physician who was unaware of the VAS. A composite score was then
obtained utilizing 4 of the 6 components of the instrument. The VAS was found to
have adequate sensitivity (91%), specificity (88%), and overall predictive value
(89%) when the composite score was used as the validity criterion. Therefore, the
VAS was used in all subsequent analyses; the median in this VAS separated
patients into high and low acculturation groups. The relationship between
acculturation and sociodemographic, behavioral/psychosocial (social support,
abnormal illness-related behaviors, and helplessness) and clinical variables
(disease duration, onset type, number of American College of Rheumatology
criteria met, disease activity, and damage) at study entry was then explored.
RESULTS: Patients in the low acculturation group had fewer years of education,
were less likely to have private health insurance, and had less social support as
compared with those in the high acculturation group; they also exhibited less
disease activity as determined by the overall physician and patient global
assessments of the Systemic Lupus Activity Measure. Abnormal illness-related
behaviors and helplessness were not increased in the low acculturation group.
CONCLUSIONS: Low levels of acculturation were associated with indicators of low
socioeconomic status, but also with less disease activity at enrollment into
LUMINA; they were, however, not associated with more abnormal illness-related
behaviors or with helplessness, as measured in this study. The possible impact of
acculturation and of its mediators in the course and outcome of SLE among
Hispanic patients needs to be determined longitudinally.
PMID- 10689992
TI - Determinants of shoulder and elbow flexion range: results from the San Antonio
Longitudinal Study of Aging.
AB - OBJECTIVE: To gain a knowledge of factors associated with impaired upper
extremity range of motion (ROM) in order to understand pathways that lead to
disability. METHODS: Shoulder and elbow flexion range was measured in a cohort of
695 community-dwelling subjects aged 65 to 74 years. Associations between
subjects' shoulder and elbow flexion ranges and their demographic and
anthropometric characteristics, as well as the presence of diabetes mellitus or
self-reported physician-diagnosed arthritis, were examined using multivariate
regression models. The relationship between shoulder or elbow flexion range and
subjects' functional reach was examined to explore the functional significance of
ROM in these joints. RESULTS: The flexion range for the 4 joints studied was at
least 120 degrees in nearly all subjects (> or = 99% of the subjects for each of
the 4 joints). Multivariate models revealed significant associations between male
sex, Mexican American ethnic background, the use of oral hypoglycemic drugs or
insulin to treat diabetes mellitus, and a lower shoulder flexion range. A lower
elbow flexion range was associated with male sex, increasing body mass index, and
the use of oral hypoglycemic drugs or insulin. A higher shoulder or elbow flexion
range was associated with a lower likelihood of having a short functional reach.
CONCLUSIONS: The great majority of community-dwelling elderly have a flexion
range of shoulder and elbow joints that can be considered functional. Diabetes
mellitus and obesity are two potentially treatable factors associated with
reduced flexion range of these two functionally important joints.
PMID- 10689993
TI - Translation to Spanish, reproducibility, and cross-cultural adaptation of the
Miller-Rahe Recent Life Change Questionnaire in Venezuela.
AB - OBJECTIVE: To translate into Spanish a version of the Miller-Rahe Recent Life
Change Questionnaire and to adapt it to Venezuelan cultural values. METHODS: The
Spanish version and cross-cultural adaptation of the Miller-Rahe Recent Life
Change Questionnaire was done following recently proposed guidelines to preserve
semantic, idiomatic, and conceptual equivalence in translations of health
assessment instruments. We performed one or more translations into the new
language, as well as back-translation, test-retest reliability, and weighting
score for the translated instrument. RESULTS: A Spanish version of the Recent
Life Change Questionnaire was obtained. Validity of translations was demonstrated
with a significant agreement for the nonliteral translations (kappa value = 0.97,
P < 0.05). The conceptual equivalence was demonstrated by significant agreement
in the back-translations (kappa value = 0.84, P < 0.05). The translated
instrument met acceptable levels of reliability, as assessed by Spearman's rank
correlation coefficients (> 0.60 for all categories of the questionnaire). The
cross-cultural adaptation of the translated instrument required addition and
exclusion of items as well as changes of the ranking and scaling of life units in
the original questionnaire. CONCLUSION: A valid and reliable Spanish version of
the Miller-Rahe Recent Life Change Questionnaire was produced and adapted to
Venezuelan cultural values.
PMID- 10689994
TI - A history of early investigation in polyarteritis nodosa.
PMID- 10689995
TI - Neurologic symptoms in simple neck sprain: comment on the review by Ferrari and
Russell.
PMID- 10689996
TI - Building nursing's future. Expanding AWHONN's expertise.
PMID- 10689997
TI - Stopping neural tube defects.
PMID- 10689998
TI - Genetics and discrimination. How nurses can help women make smart choices.
PMID- 10689999
TI - Diagnosis infertility.
PMID- 10690000
TI - The business of women's health. Building a successful women's health practice.
Part Two.
PMID- 10690001
TI - Building blocks. How one hospital designed the core components of a new NICU.
PMID- 10690002
TI - Cardiopulmonary resuscitation in pregnancy. What all nurses caring for
childbearing women need to know.
PMID- 10690003
TI - Evidence! Show me the evidence! Untangling the web of evidence-based health care.
PMID- 10690004
TI - Managing your career. Staying flexible in an evolving nursing industry.
PMID- 10690005
TI - Dealing with difficult people. Tips and techniques for enhancing communication.
PMID- 10690006
TI - Preventing neural tube defects: my personal story and mission.
PMID- 10690007
TI - What's all the fuss about "older women?".
PMID- 10690008
TI - Sign on the dotted line. Exploring your professional contract.
PMID- 10690009
TI - Balancing the scales. Nutritional counseling for women with eating disorders.
PMID- 10690010
TI - Charting in record time. Setting guidelines for documenting FHR enhancing care
for laboring women.
PMID- 10690011
TI - Postpartum depression. Stopping the thief that steals motherhood.
PMID- 10690012
TI - Continuing education gets wired.
PMID- 10690013
TI - Capitalizing on nursing creativity.
PMID- 10690014
TI - Positive outcomes. Sharing good news in a caring way.
PMID- 10690015
TI - So what's the scoop about the certificate program in holistic nursing?
PMID- 10690016
TI - Dharma and the open heart.
PMID- 10690017
TI - President's report of the State of the Association.
PMID- 10690018
TI - A closer look at the consumer bill of rights and responsibilities.
PMID- 10690019
TI - Reclaiming your own creativity.
PMID- 10690020
TI - Springtime. Awakening of holism in our lives.
PMID- 10690021
TI - Fragrances: friend or foe?
PMID- 10690022
TI - Program report for nurses certificate program in Interactive Imagery.
PMID- 10690023
TI - Watsu-aquatic bodywork.
PMID- 10690024
TI - The crystal within.
PMID- 10690025
TI - An open letter to my friends and colleagues at AHNA. From the Holistic Nurse of
the Year, 1998.
PMID- 10690026
TI - The way changes are made: incrementalism.
PMID- 10690027
TI - Healing touch certificate program.
PMID- 10690028
TI - What makes research holistic?
PMID- 10690029
TI - Tri-level affirmations: the key.
PMID- 10690030
TI - Insurance reimbursement.
PMID- 10690031
TI - The Nightingale moment. Interview by Marie Fasano-Ramos.
PMID- 10690032
TI - Dolphins and a path of healing.
PMID- 10690033
TI - Holistic healing: heritage to vision. Report of the 1999 Annual Conference
Scottsdale, Arizona.
PMID- 10690034
TI - A new healing path
PMID- 10690035
TI - Creating environmentally friendly spaces--Part I: Detoxification oasis.
PMID- 10690036
TI - Building bridges--a holistic model for practice.
PMID- 10690037
TI - Think this can't happen to you?
PMID- 10690038
TI - Readers question whether drug increases side effects of chemotherapy.
PMID- 10690039
TI - Leukocyte reduction filters may cause hypotension.
PMID- 10690040
TI - A critical pathway for patients undergoing one-day breast cancer surgery.
AB - As the trend of surgical procedures shifting from inpatient to outpatient
settings continues, outpatient-focused standardized care processes will become
more of a necessity. A multidisciplinary critical pathway (CP) for breast cancer
surgery can assist care providers in meeting patients' educational and
psychosocial needs. The CP document discussed in this article takes into account
the expedient nature of outpatient surgery and spans the continuum of care from
the surgical clinic to the postoperative homecare visit. Integrating homecare
nursing improves the quality and consistency of care.
PMID- 10690041
TI - A review of Waldenstrom's macroglobulinemia.
AB - Waldenstrom's macroglobulinemia (WM) is an uncommon B cell malignancy that
resembles other B cell malignancies, such as multiple myeloma and chronic
lymphocytic leukemia. WM's clinical course varies widely, with survival ranging
from 1-16 years. WM is diagnosed when a bone marrow biopsy reveals malignant B
lymphocytes arrested at the plasmacytoid lymphocytic stage of the maturation
process and when high levels of IgM are found in the serum blood. Common clinical
features include anemia, abnormal bleeding, and hyperviscosity, and 20%-40% of
patients present with lymphadenopathy or splenomegaly. Alkylating agents have
been the most common chemotherapy agents used to treat WM. However, nucleoside
analogues are being used more frequently with promising results. Nursing care
includes educating the patient about the disease trajectory, providing symptom
management, and monitoring the patient's response to treatment.
PMID- 10690042
TI - Closing the gap in prophylactic antiemetic therapy: patient factors in
calculating the emetogenic potential of chemotherapy.
AB - The ability to provoke emesis is defined by the emetogenic potential of each
antineoplastic agent and by individual prognostic factors that determine the risk
for each patient. The risk of chemotherapy-induced emesis is increased for
females, patients between the ages of 6 and 50, and patients who drink little or
no alcohol. Other risk factors include susceptibility to motion sickness and high
levels of anxiety. Patients with one or more risk factors may require antiemetic
treatment typically prescribed for a highly emetogenic regimen, even when a
chemotherapy regimen is considered moderately emetogenic. The 5-HT3 receptor
antagonists are the most effective agents against chemotherapy-induced nausea and
should become standard antiemetic therapy for high-risk patients. Knowledge of
factors affecting emesis and the antiemetic agents available for treating high
risk patients are the keys to successful nursing management of emesis in patients
receiving chemotherapy.
PMID- 10690043
TI - Discrimination in the workplace.
PMID- 10690044
TI - Advances in symptom management: lymphedema.
PMID- 10690045
TI - Disseminated intravascular coagulation.
PMID- 10690046
TI - Amifostine.
PMID- 10690047
TI - Picture this. Oral candidiasis.
PMID- 10690048
TI - Dyspnea and palliative care.
PMID- 10690049
TI - Poster and podium sessions provide insight into various oncologic side effects
and treatments.
PMID- 10690050
TI - Prescriptive privileges, authority, or responsibility?
PMID- 10690051
TI - Two reports of expert practice: nursing matters.
PMID- 10690052
TI - Changing pain management practice and impacting on patient outcomes.
AB - Concerns about acute pain management prompted the development of a pain
management program. The program, with assessment, intervention, and evaluation
components, was introduced by the clinical nurse specialist (CNS) in
collaboration with a multidisciplinary team. The assessment phase included a
descriptive study of postoperative pain and a baseline audit of nursing
documentation related to pain assessment and management. Interventions, including
a focused educational program and new routes for postoperative analgesia, were
then introduced. Evaluations at 3 months and 2 years indicated improvements in
documentation of pain assessments and improved management of pain. Additionally,
at each follow-up evaluation, patients reported decreased postoperative pain. The
assessment and management of pain is an important domain of nursing practice. The
CNS is in a unique position to influence nursing practice and to impact on
patient outcomes in this area of pain management.
PMID- 10690053
TI - The price of medical progress: the advance directive.
PMID- 10690054
TI - Case management of the frail elderly in the community.
AB - Nurse case management has become a popular strategy for coordinating healthcare
services to high-risk populations. This article describes the characteristics and
advantages of a unique case management approach to manage the healthcare of frail
elderly living in the community. At the heart of this approach are the nurse's
role in the engagement of the client and family, prevention, continuity of care,
and hospital, community, and caregiver team facilitator. Specific interventions
of the nurse case manager are highlighted by case studies.
PMID- 10690055
TI - So where are we?
PMID- 10690056
TI - A description of the roles, activities, and skills of clinical nurse specialists
in the United States.
AB - Clinical nurse specialists (CNSs) frequently adapt to meet the challenging and
changing needs of patients, families, nurses, physicians, and institutions, thus
creating an advance practice role that is problematic in definition and
description. The two dilemmas associated with CNSs have been role confusion and
ambiguity, and the inability to explicate CNSs' value in economic terms. The
purpose of this study was to describe the roles, activities, skills, and the cost
saving and revenue-generating activities of Master's-prepared nurses who function
in traditional CNS roles in the United States. A descriptive research design was
employed, using Role Theory as a framework to guide the study. The tool used to
measure CNS practice included a 68-item instrument. It was pretested and used in
two pilot studies. Content validity was supported by three experienced CNSs who
were, at the time, in a doctoral nursing program. Instrument reliability was
0.89. Surveys were mailed to all individuals who subscribed (n = 2379) to the
Clinical Nurse Specialist Journal. From the convenience sample, 724 CNSs
participated, providing a margin of error of +/- 4 percentage points with a 99%
confidence level. Regarding the five role components, CNSs reported (listed from
most frequently to least frequently) spending time in the role of expert
practitioner, educator, consultant, administrator, and researcher. Most of the
activities listed in each of the roles were typical of CNS practice. Of the
advanced practice roles, the two with the most surprising results were the expert
practitioner and administrator roles. The results indicated a trend toward
performing advanced skills that have been in the past considered solely medical
practice and toward increasing administrative responsibilities. A small number of
CNSs were able to identify cost-saving and revenue-generating activities,
including the monetary value of the activity.
PMID- 10690057
TI - Political influence: a model for advanced nursing education.
AB - Involvement in shaping healthcare policy is an expected outcome for the
leadership standard of advanced nursing practice as outlined by American Nurses
Association's Scope and Standards of Advanced Practice Registered Nursing (1996).
From personal experience teaching a healthcare policy course over a 10-year
period, the author has found that beginning graduate students are primarily in an
apolitical state, reluctant to participate in such activity, and have not
considered the ramifications of inactivity for the profession and for healthcare
policy. The skills for political influence are an essential component of graduate
education to increase awareness of, and foster activity in, the political arena.
A model for the development of these skills is presented. The model consists of
four interrelated dimensions: information, commitment, initiative, and
involvement. Model dimensions are described and made operational through student
activity. Ultimately, students move from an apolitical state to a moderate level
of involvement. The model has been intended for educational purposes; however, it
is applicable for any advanced practice nurse (APN).
PMID- 10690058
TI - Strategies for working with a state board of nursing.
PMID- 10690059
TI - Is Louisiana a reflection on the state of master's-prepared nurses nationally?
PMID- 10690060
TI - Hospital and parish (county) utilization of master's-prepared nurses in
Louisiana.
AB - Recent regulation in Louisiana involving advanced practice nursing, combined with
new educational standards at the Master's level established by the Louisiana
State Board of Nursing, prompted a statewide survey of hospitals and parish
health units. The purpose of the survey was to determine whether and to what
extent Master's-prepared nurses were being used in Louisiana and to identify the
importance placed on role functions and activities generally associated with the
advanced practice nurse (APN). The survey included open-ended questions
concerning expectations about future hirings and perceptions of future roles and
duties of the Master's-prepared nurse as well as suggestions to educators on what
is needed to better prepare nursing students at the Master's level. Results from
this exploratory survey provide information on APN utilization with implications
for nursing educators and administrators as well as APNs.
PMID- 10690061
TI - Creating "asset-rich" environments.
PMID- 10690062
TI - Partners in psychiatric-mental health nursing.
PMID- 10690063
TI - Homeless parents: parenting education to prevent abusive behaviors.
AB - PROBLEM: This study sought to measure the effects of a short-term parenting
course for homeless parents to decrease their parenting stress and potential for
abusive parenting behaviors. SAMPLE: Nineteen homeless parents lived in a family
emergency shelter for homeless families in Hillsborough County, FL. Their average
length of shelter stay was 3 weeks. METHODS: Residents were invited to
participate in a parenting education course consisting of three 1-hour classes
weekly for 3 consecutive weeks. Class content focused on the parent, the child,
and discipline. Subjects' potential for child abuse was measured with the Adult
Adolescent Parenting Inventory and their parenting stress with the Parenting
Stress Index. A quasi-experimental pre/posttest design was used, with a t test
statistic at the .05 level of significance. Descriptive statistics were used to
analyze selected demographic data. FINDINGS: Results revealed significant
differences in the scores of parenting stress originating from the child domain
of the PSI and in the scores on the construct of unrealistic expectations of the
child in the AAPI. Both scores had decreased on the posttest. CONCLUSIONS: Short
term parenting education courses may be a useful intervention strategy.
PMID- 10690064
TI - Parental murder and suicide: post-traumatic stress disorder in children.
AB - TOPIC: Post-traumatic stress disorder (PTSD) diagnosed in a 9-year-old who
witnessed her parents' murder and suicide. PURPOSE: To provide a historical
overview of PTSD in children in general and to discuss one case study in
particular. SOURCES: Personal observations and experiences, and a review of both
classic and contemporary literature in child psychiatry and developmental
psychology. CONCLUSIONS: Supportive psychotherapy for a traumatized child with
clinical supervision for the care-giver showed evidence of the recovery process
in one PTSD case study.
PMID- 10690065
TI - Beyond cause and effect: some thoughts on research and practice in child
psychiatric nursing.
AB - TOPIC: A comprehensive conceptual framework that informs about the complexity of
childhood psychopathology. PURPOSE: To discuss the importance of a unifying
conceptual framework and multiple partnerships in research and practice that can
inform critical events and effects of interventions at various system levels in
the treatment of children. SOURCES: Literature review. CONCLUSIONS: The most
informative research and intervention will occur by using multiple measures and
sources of information. As understanding of children and their problems in
development and in context grows, intervention research that will be both useful,
timely, and cost-effective must include cross-discipline teams of researchers and
practitioners who will speak to these complexities.
PMID- 10690066
TI - Kaleidoscope of excellence. An interview with Judy Coucouvanis, MA, RN, CS, NP.
Interview by Linda M Finke.
PMID- 10690067
TI - The therapeutic use of music for dyspnea and anxiety in patients with COPD who
live at home.
AB - The purposes of this repeated measures study were to examine the feasibility of
using music as an intervention for dyspnea and anxiety in patients with chronic
obstructive pulmonary disease (COPD) who live in their homes and to examine the
effect of music on anxiety and dyspnea. Twenty-four participants who experienced
dyspnea at least once a week were studied over a 5-week period. Baseline data
were collected on Week 1. Measures of anxiety and dyspnea were taken on Week 2,
prior to and immediately following the use of music. These measures were repeated
on Week 5. There was a significant decrease in dyspnea following the use of music
as reported in the music diary (p < .001). There was a significant decline in
anxiety (p < .05) and dyspnea (p < .01) following the use of music on Week 2.
There was no significant change in anxiety or dyspnea over the 5-week period.
PMID- 10690068
TI - Self-transcendence and activities of daily living. The woman with the pink
slippers.
AB - The number of older adults in our population is steadily increasing. Many older
adults continue to remain active and care for themselves. However, differences
exist in older adults' ability to perform activities of daily living. The purpose
of the study was to explore relationships among self-transcendence (ST), health
status (SHS), and ability to perform activities of daily living (ADL) in
noninstitutionalized older adults. The 88 participants were primarily widowed,
White women, 65 years of age and older (M = 73.4), who perceived their health
positively, and had 12 years or more of education. Findings included
statistically significant relationships between ST and ADL and SHS and ADL.
Twenty-two percent of the variance in ability to perform ADL was explained by
SHS, and an additional 6% was explained by ST. Nurses are encouraged to explore
factors that contribute to older adults' ability to remain independent.
PMID- 10690069
TI - A research-based use of Tai Chi/movement therapy as a nursing intervention.
AB - Tai Chi has been widely practiced in China for centuries as an art form,
religious ritual, relaxation technique, exercise, and a method of self-defense
for people of all ages. It has been used to improve balance; promote postural
stability; decrease falls; enhance cardiovascular and ventilatory functions;
rehabilitate persons with acute myocardial infarction and rheumatoid arthritis;
and reduce pain, stress, and nightmares. The purpose of this article is to
summarize, synthesize, and critically evaluate the research-based use of Tai Chi
presented in the current literature and give implications and directions for
future research. Additional studies about the effects of Tai Chi from a nursing
perspective are needed to make clear when it is beneficial as a nursing
intervention.
PMID- 10690070
TI - Cultural and spiritual meanings of childbirth. Orthodox Jewish and Mormon women.
AB - This descriptive, phenomenological study investigated the cultural and spiritual
meanings of the childbirth experience from the personal perspectives of 30
Canadian Orthodox Jewish and 30 American Mormon women. Fewer Jewish women had
childbirth education and attendance of their partners during childbirth than did
Mormon women. Participants in the study, having codified belief systems,
expressed the primary importance of bearing children in obedience to religious
law. Birth was articulated as a bittersweet paradox, often accompanied by a sense
of empowerment. Women described the importance of personal connectedness with
others and with God, the importance of childbearing, and the spiritual and
emotional dimensions of their childbirth experiences. Religious beliefs help
women define the meaning of childbirth and may provide coping mechanisms for the
intensity of giving birth. It is essential for holistic nurses to value and
acknowledge the cultural and spiritual dimensions of the childbirth experience.
PMID- 10690071
TI - A collaborative research project on Therapeutic Touch.
AB - The current shift toward granting funds for collaborative research proposals
means that graduate nursing students must be prepared to participate in the
collaborative research process. The authors describe how master's and doctoral
students worked together with faculty to establish group norms, investigate,
design, and disseminate a research proposal on Therapeutic Touch. Project goals,
description of group members, and the benefits and limitations of collaborative
research also are included. Evaluating the collaboration as a challenging yet
enjoyable learning experience, students and faculty shared a successful scholarly
endeavor that ultimately led to funding and implementation of a research proposal
on Therapeutic Touch.
PMID- 10690072
TI - Shared governance: time to consider the cons as well as the pros.
AB - AIMS: This paper aims to provide a critical appraisal of an approach to the
management and organization of nursing work known as shared governance (SG).
BACKGROUND: This approach has its origins in the USA, where, during the past 20
years it has become increasingly influential. The advocates of SG claim that it
can, inter alia, improve recruitment and retention rates, boost morale, and help
raise clinical skills. Little wonder that SG in now beginning to make significant
inroads into the NHS. ORIGIN OF INFORMATION: However, a trawl through the
extensive US literature, using printed and online (e.g. BIDS, CINHAL, MEDLINE,
etc.) bibliographical sources, suggests that the claimed benefits of SG should be
treated with caution. KEY ISSUES: Much of the existing published research appears
to be both methodologically flawed and lacking in any critical edge. While many
researchers and commentators appear only too willing to highlight what they see
as the promise of SG, they shy away from exploring any potential pitfalls. One
consequence of this is that many of the putative benefits SG is said to confer,
may in fact be more apparent than real. CONCLUSIONS: Nurses and nurse managers
need to be apprised of and consider seriously, the possible cons as well as the
potential pros of SG, if any promise it may have is to be realized.
PMID- 10690073
TI - Managing the unmanageable: risk assessment and risk management in contemporary
professional practice.
AB - AIM: This study sets out to investigate the theories and practices of risk
assessment and management in the context of contemporary mental health practice.
BACKGROUND: Although risk assessment and management policies are well established
for those working in the field of community mental health care, there are
noticeable anomalies and regional variations, in the criteria, procedures and
decision-making strategies used. METHODS: Focus group taped interviews were
conducted with over 100 mental health professionals in one NHS Trust. These were
compared with an extensive literature review on the topic. FINDINGS: The main
theme to emerge was lack of resources, which included time and staff in the
context of a changing and increasing workload. Another important theme was the
lack of access to centralized and accurate information about mental health
service provision. CONCLUSION: It is essential that professionals, clients, their
families and the public feel confident in professional judgements and practices
to avoid a 'back to the asylum' lobby, for the care and treatment of seriously
mentally ill individuals.
PMID- 10690074
TI - Job satisfaction and stress in staff working in a specialist psychiatric unit for
the elderly following relocation from a traditional psychiatric hospital setting.
AB - AIM: This study examines self-reported stress and job satisfaction of staff
working in a specialist psychiatric unit for the elderly (n = 79) following
relocation from a traditional psychiatric hospital setting (n = 66). The levels
of reported stress were examined in relation to the two staff groups before and
after the relocation, and in relation to data available for similar occupational
groups. METHODS: Stress and job satisfaction levels were surveyed using the
Occupational Stress Indicator. The analysis of data included t-test for
independent groups. FINDINGS: The results suggested that that there were no
significant changes in the patterns of the staff groups' experience of stress at
the traditional psychiatric hospital and later at the new purpose-built unit.
However, it was felt that there may have been different factors contributing to
staff stress at the two time-points. The staff groups in this survey reported
similar, and in some areas more positive levels of occupational stress than both
community and other health authority samples. However, it was felt that, due to
the limited response rate of staff at both times (63 and 59%), the results may be
an underestimate of stress levels. In the absence of a measure of general health
and symptomatology it was not possible to assess the impact of stress levels on
the psychological well-being of staff. CONCLUSIONS: Routine audit of staff stress
would be beneficial to identify potential for staff training, and individual
professional development plans. This is particularly important in view of the
current difficulties both locally and nationally in the recruitment and retention
of qualified staff in this speciality.
PMID- 10690075
TI - Quality in post-basic nurse education: the need for evidence-based provision.
AB - BACKGROUND: As one means of addressing the problem of providing high quality
health care within a context of diminishing resources, the British National
Health Service (NHS) has promoted the concept of evidence-based clinical care. In
order to integrate this concept effectively within routine practice, nurses need
a sound knowledge of fundamental research methods. Unfortunately, the research
skills courses that have been provided have typically relied on assumption to
determine course content and chance factors for recruitment. Unsurprisingly, such
haphazard provision is highly wasteful of resources, targeting neither the real
skill deficits of the workforce nor the personnel most in need of this type of
training. AIM: To demonstrate a more systematic approach to identifying the skill
deficits of any specified workforce. METHODS: A survey was conducted with a
random sample of nurses, who covered a range of grades and clinical specialities,
using a psychometrically valid and reliable training needs analysis tool.
FINDINGS: The results revealed both common training needs as well as skill
deficits pertinent to a given locality and clinical area. CONCLUSIONS: Using more
objectively derived information affords the commissioning of customized research
skills courses that have the capacity to meet the needs of both the local
organization and its employees. In this way, limited training budgets can be more
effectively targeted.
PMID- 10690076
TI - Preparing adult branch students for their management role as staff nurses: an
action research project.
AB - AIM: This action research project aimed to investigate students', newly qualified
staff nurses' and ward managers' views about the management skills and knowledge
required by staff nurses, and how best students could be prepared for their
management role. BACKGROUND: The importance of the staff nurse's management role
is increasingly being recognized but the literature highlights the difficulties
in preparing students for management, and personal experience confirmed this.
METHODS: Focus group interviews were held with senior students and newly
qualified staff nurses. A questionnaire was then developed which was completed by
23 ward managers. FINDINGS: A good insight into the management skills and
knowledge expected of newly qualified staff nurses, and useful ideas about
preparation for the role emerged. An extra 2 weeks in practice, supernumerary and
with specific management learning outcomes, was implemented and evaluated well.
CONCLUSIONS: Preparation of students for their management role as staff nurses
benefits from being closely linked to practical experience, with clear learning
outcomes and supportive clinical staff. Using an action research approach to
investigate the problem and develop a strategy was found to be an appropriate
methodology.
PMID- 10690077
TI - Outcomes of implementing primary nursing in the care of people with chronic lung
diseases: the nurses' experience.
AB - AIM: This study describes the outcomes of an action research project carried out
to implement primary nursing in the care of people with chronic lung diseases at
two hospital units in Iceland. METHODS: The methodological approach was the
interpretative perspective. Data from transcribed interviews with 21 nurses and a
research journal written by the author were analysed. Themes were generated
according to dialectical procedures of interpretation. FINDINGS: The following
themes were identified: close relationships with patients, continuity of care,
reports of satisfied and secure patients, centrality of individual patient's
needs, constant refinement of the system, sensitivity to staffing load and
ambitious and responsible nurses. CONCLUSIONS: The nurses participating in this
study clearly valued the possibilities that primary nursing brought in terms of
higher quality of care for their patients. One of the most important components
of high quality care is to know and understand patients' experiences, which is
the main outcome of this study. This indicates that implementing primary nursing
in the care of people with chronic lung diseases was beneficial from the point of
view of the nurses. However, concerns were raised that primary nursing is more
sensitive to low staffing than the system it was meant to replace.
PMID- 10690078
TI - Helping families make time.
PMID- 10690079
TI - What is new in asthma: new dry powder inhalers.
AB - Asthma affects an estimated 4.8 million children. The pressurized metered-dose
inhaler (pMDI), despite problems associated with its use and concern that most of
these inhalers contain ozone-damaging chlorofluorocarbons (CFCs), is currently
the device most frequently used to deliver inhaled medication. Concerns regarding
pMDIs that contain CFCs have led to further development of alternative delivery
devices, including CFC-free pMDIs, breath-actuated devices, and dry powder
inhalers (DPIs). Advantages and disadvantages of these devices are discussed
briefly, with emphasis on the new DPIs. A brief overview of their safety,
efficacy, and acceptance by patients is presented. DPIs have the potential to
become important devices for administration of inhaled medication in pediatric
asthma management.
PMID- 10690080
TI - The President Clinton crisis and the Starr report: children's perceptions and
parents' awareness.
AB - INTRODUCTION: The media have suggested that the President Clinton crisis, as
publicized by the Starr Report, has had detrimental effects on school-age
children. Parents, too, have been concerned that their children are confused
about the presidential controversies involving dishonesty, mistrust, betrayal,
infidelity, and misuse of authority. The purpose of this study was to explore the
perceptions and reactions of school-age children to information surrounding the
President Clinton situation, as well as parents' perceptions of their children's
knowledge and reactions. METHOD: A descriptive, qualitative design was used in
this study. Data collection took place during the 2-week period following
publication of the 1998 Starr Report. Fifty-one parents and 67 school-age
children were interviewed using semi-structured interview guides with 5 open
ended questions addressing the President Clinton situation. RESULTS: Major themes
that emerged from children's interviews were lying, getting caught, infidelity,
and role modeling. Parents' awareness of their children's knowledge regarding the
President Clinton situation varied; few were aware of the depth of knowledge
their children had, nor had they discussed this situation with their children.
DISCUSSION: Findings have relevance for nurse practitioners as they support
parents in listening to and talking with their children about tough issues such
as morality and sexuality in the context of real life events.
PMID- 10690081
TI - Infant cranial molding deformation and sleep position: implications for primary
care.
AB - Infant positional plagiocephaly, a cranial molding deformity expressed by
asymmetrical head shape, is on the rise. The increase correlates with the
recommendation by the American Academy of Pediatrics that infants be placed on
their backs to sleep to reduce the risk of sudden infant death syndrome. The
majority of misshapen heads develop because infants are placed to sleep in the
same supine position, without head rotation. Infant molding deformities will
generally improve with repositioning and cranial growth, but permanent
deformation can occur, especially without early treatment. This article informs
pediatric practitioners about positional plagiocephaly, offers preventative and
treatment interventions, and reviews treatment options.
PMID- 10690082
TI - A descriptive study of missed appointments: families' perceptions of barriers to
care.
AB - INTRODUCTION: When clinic appointments are missed, families deprive their child
of health care opportunities and contribute to rising health care costs. The
purpose of this study was to determine families' perceptions of barriers to
attending clinic appointments. METHOD: Two hundred participants with a history of
missed appointments were randomly selected to participate in a telephone survey.
Ninety-five of the families selected did not have telephones. Of the 105 families
contacted by telephone, 101 consented to participate in a survey. For the group
without phones (n = 95), demographic information was collected to use as
comparison data with families that were reached. Patterns of missed appointments
were also analyzed. RESULTS: The majority of families were headed by young single
mothers. The families identified transportation problems, wait times, and not
knowing the reason for the appointment as barriers. DISCUSSION: Clearly, many
issues have an impact on decisions related to attending clinic appointments. In
the interest of health, interventions to decrease barriers and increase
attendance should be a priority for health care professionals. Further research
of the effectiveness of these interventions will delineate the appropriate focus
of health care professional's efforts.
PMID- 10690083
TI - New challenges, new answers: pediatric nurse practitioners and the care of
adolescents.
AB - INTRODUCTION: Since the 1950s, patterns of morbidity and mortality among
adolescents have shifted to social and environmental causes. This study examines
pediatric nurse practitioners' (PNPs') self-assessed competencies in addressing
the common health concerns of adolescents. METHOD: The analysis used a sample of
257 PNPs drawn from a larger national data set of 637 nurses randomly sampled
from 3 nursing organizations. Factors associated with self-perceived knowledge or
skill and interest in training for 28 common health concerns of adolescents were
analyzed using Chi square, t test, and Pearson's correlation. Barriers and
attractions to working with adolescents were also investigated. RESULTS: The
greatest deficits in self-perceived knowledge or skill, as well as low interest
in training and low perceived relevance to practice, were around issues of gangs,
gay/lesbian/bisexual/transgender youth, HIV/AIDS, and counseling about a positive
pregnancy test. Also, PNPs identified the lack of resources appropriate for
adolescent referrals as the greatest barrier to working with this population.
DISCUSSION: PNPs assessed their lowest competencies in some of the areas that
present the greatest threats to adolescents' health and well-being. These
deficits suggest needed curricular shifts in entry-level and advanced-level
preparation of PNPs, as well as new priorities for continuing education.
PMID- 10690084
TI - Palivizumab for respiratory syncytial virus prophylaxis.
AB - Palivizumab, a humanized monoclonal antibody, has been approved by the FDA to
prevent severe lower respiratory tract infections caused by RSV in high-risk
patients. Prophylaxis of RSV infections with palivizumab requires monthly
injections (15 mg/kg) during the RSV season. In the IMpact-RSV study,
hospitalizations resulting from RSV decreased by 55% in the palivizumab treatment
group. Palivizumab has also been shown to decrease the number of days with
moderate or severe RSV infection, with an increased oxygen requirement, and ICU
admissions. Palivizumab has been shown to be well tolerated with minimal adverse
effects. The most frequently reported adverse effects were fever and minor
injection site reactions. Determination of which patients should receive RSV
prophylaxis should take into consideration all risk factors. Recommendations for
RSV prophylaxis with RSV-IGIV and palivizumab have been published by the American
Academy of Pediatrics. To date, no studies directly comparing RSV-IGIV and
palivuzumab have been conducted. Neither product is recommended in children with
congenital heart disease.
PMID- 10690085
TI - Girl with a recurrent cough.
PMID- 10690087
TI - Disease management: what does it mean for nurse practitioners?
PMID- 10690086
TI - NAPNAP supports new children's health bill.
PMID- 10690088
TI - Selective serotonin reuptake inhibitors: implications for advanced nursing
practice.
AB - The efficacy of SSRIs in treating depression as compared to other classes of
antidepressants is well documented. There is a growing body of knowledge
documenting differences and similarities among these drugs, including half-life
elimination, side effects, drug interactions, dosing and cost. These data must be
reviewed before prescribing. Providers must take caution when giving SSRIs to
patients who have been on other antipsychotics, especially MAO inhibitors,
elderly patients, patients who are pregnant, and patients on type 1C
antiarrhythmia agents.
PMID- 10690089
TI - Abdominal aortic aneurysm: diagnosis, treatment, and implications for advanced
practice nursing.
AB - The nurse practitioner needs to acknowledge that not all patients are insightful.
The patient who is naive, stoical, or in denial may not return to his previous
level of health. Behavioral or environmental changes may be a necessary part of
recovery. The advanced practice nurse, through her research and subsequent
knowledge, can identify and implement holistic changes necessary for the
maintenance of health and the development of appropriate health-seeking behaviors
that lower the morbidity and mortality for such conditions as abdominal aortic
aneurysms. Nurse practitioners play a vital role in research, prevention and
early detection of major threats to wellness (Lawler and Schmidt, 1992). Gender
sensitive research regarding factors affecting recovery are also necessary as
females respond differently to such conditions as renal failure (Carlson and
Eisenstat, 1995).
PMID- 10690090
TI - Medical chemical sensitivities: an overview.
PMID- 10690091
TI - Hepatitis C.
AB - Hepatitis C virus infection is responsible for significant morbidity and
mortality worldwide. Advances in detection and monitoring of hepatitis C virus
infection, as well as treatment protocols, have contributed to the medical focus
on this high profile disease. Presence of risk factors should increase the
clinicians index of suspicion for this symptomatically nonspecific disease.
PMID- 10690092
TI - Missed immunization opportunities: a comparison of nurse practitioners and
physicians.
PMID- 10690093
TI - Giardia lamblia in adults: a case study.
PMID- 10690094
TI - Priori outcomes: oxymoron or practice plan.
AB - This assessment helped shape the practice of a nurse administered mobile clinic
serving three rural communities. Needed services were identified and existing
services were customized to improve the overall health of the communities. With
the dynamic state of health care systems, each practice is subject to influence
by managed care and populations who, in turn, respond with changes in need,
resources, and adaptation to the system dynamics. Nurse practitioners struggling
to match resources and patient needs could use a similar research design to
assess their practice, discover significant relationships, and redesign practice
plans to fit specific practice settings.
PMID- 10690095
TI - Fragile X syndrome.
AB - Fragile X syndrome is the most common inherited condition causing mental
retardation in males. Females with the full mutation expansion can have milder
signs of the disorder. Families with members who have been diagnosed with fragile
X syndrome face concerns about the health of their newborn infant, decisions
regarding family planning, and questions about the possibility that other family
members could have this disorder. Neonatal nurses participate in assessment,
health care management, counseling, and referral of the families regarding this
syndrome.
PMID- 10690096
TI - Nonimmune hydrops fetalis.
AB - Hydrops fetalis is a relatively rare phenomenon that presents itself in the
delivery room in an extremely acute manner. Prompt resuscitation, an
understanding of the condition and its presentation, and immediate treatment can
make the difference between life and death in these cases. The focus of this
article is on nonimmune hydrops, the type of hydrops seen in the clinical
setting. Maternal and fetal pathophysiology, current theories, diagnostic
evaluations, neonatal pathophysiology, clinical manifestations, treatment
options, pertinent research, and the needs of the family are discussed.
PMID- 10690097
TI - Percutaneously inserted polyurethane central catheters in the NICU: one unit's
experience.
AB - This article describes the authors' experiences with using polyurethane
percutaneously inserted central catheters from June 1993, when these catheters
were introduced in the NICU at Children's Hospital, Omaha, Nebraska, through
September 1997. Indications for line placement and anatomy are reviewed. Patient
demographics, success rates, and complications are analyzed. Line cares,
including dressing changes, management of infusions, and troubleshooting, are
also discussed.
PMID- 10690098
TI - Efficacy of saline vs heparin in maintaining 24-gauge intermittent intravenous
catheters in a rabbit model.
AB - PURPOSE: The purpose of this study was to compare saline and heparin flushes in
24-gauge i.v. catheters. DESIGN: A double-blind experiment in four recorded
trials was conducted using a rabbit model. Twenty-four-gauge catheters were
placed in both auricle veins, and all catheters were secured in the same manner.
Ampicillin was infused into each ear at the same interval, with each ear
randomized to receive either the heparin solution or the saline solution. SAMPLE:
The subjects were ten white New Zealand rabbits. Data were collected on 76
catheter sites. MAIN OUTCOME VARIABLE: Patency for each catheter was measured in
hours and evaluated based on presence of warmth, erythema, induration, leakage,
or occlusion. RESULTS: There was no significant difference in the duration of
patency of the catheters between the two groups.
PMID- 10690099
TI - Use of biomagnetic therapy to encourage growth in preterm neonates.
PMID- 10690100
TI - Thimerosal in vaccines: a joint statement of the American Academy of Pediatrics
and the Public Health Service.
PMID- 10690101
TI - Visitation patterns: parents who visit "too little".
PMID- 10690102
TI - Erythromycin.
PMID- 10690103
TI - Keeping score in case management.
PMID- 10690104
TI - Nurse-managed wound clinic. A case study in success.
AB - The wound Care Clinic at Naval Hospital Charleston is a nurse-managed ambulatory
clinic that has demonstrated the successful application of nursing case
management in caring for patients with chronic and complex wounds. Nursing case
management is an outcomes-based system of assessment, planning, provision of
nursing services, coordination of interdisciplinary efforts, education, and
referral. Nursing case management has been shown, in the literature and at Naval
Hospital Charleston, to be an extension of role of professional nursing practice
and results in decreased costs, improved quality of care, faster wound healing
times, decreased complications, and greater coordination of care between
specialty disciplines. These positive results are illustrated in several case
studies. Nursing case management has many implications for the successful
implementation of any healthcare delivery system where decreased costs and
improved quality of care are valued, and it has special benefit in the complex
management of chronically ill patients.
PMID- 10690105
TI - Selecting and implementing a care management system.
PMID- 10690106
TI - Outcomes measurement in healthcare. New imperatives for professional nursing
practice.
AB - Quality of healthcare is measurable and nurses in all settings are increasingly
being expected to actively participate in identifying and measuring patient
outcomes. To do so requires an understanding of the tools and processes currently
being used to measure the quality of healthcare in this country. This article
provides an overview of current efforts in the healthcare field to develop a
shared outcome language and standardized national quality indicators. The
challenges professional nurses face in identifying and measuring nursing
sensitive patient outcomes and the responsibility to use that data to shape
nursing practice are emphasized.
PMID- 10690107
TI - An experience of community.
AB - This is a personal experience in case management. The current surge of case
management programs across the country has made a significant impact on the lives
of many patients. But, does anyone ask, "What is the impact on those who are case
managing?" As we share the struggles, griefs, and pains of our patients, we
should never lose sight of the fact that who we are and what we did made a
difference.
PMID- 10690108
TI - Developing a patient education video as a tool to case manage patients who have
had strokes.
PMID- 10690109
TI - Efficacy of primary care in a nursing center.
AB - Nursing opportunities have expanded beyond the traditional bedside role. Nurses
serve in a variety of roles such as administrators, teachers, or primary care
givers in a variety of settings. The role of primary care giver is a more recent
role; it involves relatively independent nursing practice with clients who have
acute or chronic illnesses. Client groups may include the elderly in high rise
buildings, mothers and children at schools, or homeless and low-income
populations at homeless shelters. This care is often provided in a nursing
center. Nursing centers are nurse-managed centers in which nurses are accountable
and responsible for care of clients; they are the primary provider of care and
the one most seen by clients. Case managers may be in a position to refer
patients to nursing centers or to work directly with nurse practitioners in
nursing centers. However, questions about the primary care provided in nursing
centers must be addressed for healthcare providers, insurance companies, and
patients to be confident in the efficacy of this delivery system. Is the primary
care comprehensive? Is it of high quality? Is it cost effective? Is it
satisfactory to clients? These and other questions about the primary care
provided in nursing centers must be answered to effect political and other
changes needed to fulfill the role of nursing centers envisioned by early leaders
of the movement. This article addresses questions related to the efficacy of
primary care provided in nursing centers by family nurse practitioners. After
defining efficacy, the discussion focuses on the components identified and
studied in one nursing center and includes information on opportunities for case
managers to utilize nursing centers for referral and appropriate follow-up of
their patients.
PMID- 10690110
TI - Nursing education and practice: revisiting the reunification challenge.
PMID- 10690111
TI - A comparison of pain perception of elderly African Americans and Caucasians.
AB - This study explored the differences and similarities in pain perception reported
by 32 elderly African Americans and 32 elderly Caucasian subjects. Using the
McGill-Melzack Pain Questionnaire, the study revealed that both groups chose the
word nagging most frequently to describe their pain. A 2 by 2 analysis of
variance indicated a statistically significant difference between the subjects in
terms of the present pain intensity (PPI) (F = 6.30, df = 1, P = .015). Pearson's
Product Moment Correlation revealed a moderate correlation (r = .36, P = .01)
between PPI and ethnicity.
PMID- 10690112
TI - Nursing faculty's handling of academic dishonesty.
PMID- 10690113
TI - Integrating multidimensional stress management into a baccalaureate nursing
curriculum.
AB - The mandate for self-care for holistic nurses can be satisfied with a
multidimensional stress management program. This article describes a
quasiexperimental pilot study that assessed the need for such a program for
senior students in a baccalaureate degree nursing program. Strategies are
suggested to integrate these techniques into nursing education.
PMID- 10690114
TI - Collaboration between community nurses and nursing faculty using substance abuse
prevention focus groups.
AB - Collaboration between community nurses and nurses from a university who conducted
focus groups is discussed. The focus groups explored why low-income, inner-city,
white women of childbearing age did not abuse drugs. This partnership effort
resulted in positive, successful outcomes for both groups of nurses and yielded
culturally sensitive information that may be useful in preventing substance
abuse. Methods of facilitating this collaboration and results of our joint
endeavors are explored.
PMID- 10690115
TI - A student-developed tool for assessing safety in schizophrenic patients.
AB - Schizophrenia is a chronic, disabling disease of mind and behavior. Since some
schizophrenics are prone to violence, nursing students devised a safety risk
assessment tool to help health care personnel screen clients in acute care
settings who may be at risk for violent behavior. The tool is accurate, quick,
and user-friendly, and it enhances communication among members of the
multidisciplinary health care team. The results obtained from the assessment tool
guide nurses and other health care team members in implementing appropriate
interventions. Future research and pilot studies are warranted to increase the
reliability and validity of this tool.
PMID- 10690116
TI - Connecting across the miles: interdisciplinary collaboration in the evaluation of
critical thinking.
AB - A pilot study in which faculty from nursing and English departments at two
universities in different states shared a common evaluation tool and collaborated
through e-mail to evaluate the evidence of critical thinking in writing
portfolios of baccalaureate and masters' nursing students. Loxley's (1997) four
processes--assessment, building, managing the process, and evaluating--are used
as a framework for describing collaboration among the disciplines in the two
universities. Social exchange theory was used to explain the collaboration
between participants. All six professors learned a great deal from studying and
scoring the writings, but they learned most from each other through their e-mail
dialogue.
PMID- 10690117
TI - The shortage to beat all shortages.
PMID- 10690118
TI - Critical thinking. The spirit of inquiry.
PMID- 10690119
TI - Organ donation and the critical care nurse.
AB - CACCN supports the process of organ donation. Nurses working in critical care are
in a privileged position to positively influence organ donation success; however,
the process can be emotionally very difficult. Facility commitment, agency
culture and medical practice are also crucial to the process of organ donation.
Despite our commitment to support organ donation as an option, the critical care
nurse's primary responsibility is to the potential donor and their family.
Throughout the process, the critical care nurse must remain non-judgmental and
supportive of the family, regardless of their decision. Ultimately, the nurse
must balance organ donation with the needs of the family who is experiencing the
tragic and untimely loss of a loved one. Finding this balance is never an easy
task.
PMID- 10690120
TI - CACCN position statement. Advance directives [practice guideline].
PMID- 10690121
TI - Sucrose as analgesia for neonates experiencing "mild" pain.
AB - Health care professionals who care for neonates have few treatment options for
the management of mild, sporadic painful events, such as those associated with
venipuncture. A number of research studies have demonstrated sucrose to be an
efficacious analgesic for mild procedural pain in neonates. The historical
therapy of the "sugar nipple" has even been replaced with sucrose. A discussion
of the pharmacologic principles, available research regarding dose-response
relationships and implications for nursing care is presented in this article to
allow the reader to consider how this adjunctive therapy may be incorporated into
care of the neonate. Rather than considering sucrose as a replacement for
traditional analgesics, this easily administered and seemingly safe intervention
could be used as another adjunctive therapy in treating mild pain for neonates.
Future directions of research may identify the precise mechanism of action that
sucrose takes in the neonate, the gestational and chronological ages when sucrose
is most efficacious, and the consequences of frequent or repeated dosing with
term and low birth weight infants.
PMID- 10690122
TI - Challenging restricted visiting policies in critical care.
AB - The need for family members to visit their loved ones when they have been
admitted into the critical care unit was identified in 1979 by Molter in the
critical care family needs inventory (CCFNI). This need has been the centre of
controversy for critical care units for many years. This article provides an
overview of literature that refutes some of the rationales that have been used to
restrict family visiting in the critical care unit. An overview of a liberalized
(open, contract, inclusive or structured) visiting policy is discussed as an
option to the restricted visiting policy.
PMID- 10690123
TI - Who was Cherry Ames ... and where is she now?
PMID- 10690124
TI - Introduction to sinus disease: I. Anatomy and physiology.
AB - Chronic rhinosinusitis is the most common chronic illness in the United States.
An understanding of the anatomy of the paranasal sinuses, their functioning in
health and in disease, and the contributing factors that are critical to the
pathogenesis of rhinosinusitis is essential for nurses caring for patients with
this prevalent disease. This paper will provide the otorhinolaryngology (ORL)
nurse with an overview of the scientific principles important in rhinosinusitis,
as well as presenting a framework for the understanding of rhinosinusitis and its
treatment. (This paper is the first in a series of two articles. The second part
will review the diagnosis and treatment of chronic rhinosinusitis.)
PMID- 10690125
TI - Patient's Bill of Rights Act 1998.
AB - For nurses, patient advocacy has always been a responsibility of practice.
Advocacy is rooted in the concept of individual rights. Consumers of the product
of health care now have increased protection because of the Patients' Bill of
Rights Act of 1998. Legislation has created a template to outline important
rights and processes to assure quality health care.
PMID- 10690126
TI - Writing for publication Part II--The writing process.
AB - You have selected a topic, gathered resources, and identified your target
audience. The next step is to begin to write and organize your ideas. Initiating
the actual writing process can be intimidating, especially for a novice author.
This portion of the writing for publication series focuses on helping the writer
to organize ideas and get started.
PMID- 10690127
TI - Measuring sedation in the ICU: guidelines on the scales?
PMID- 10690128
TI - Orexins: a new family of neuropeptides.
PMID- 10690129
TI - The Brussels sedation scale: use of a simple clinical sedation scale can avoid
excessive sedation in patients undergoing mechanical ventilation in the intensive
care unit.
AB - Sedation is an important component of patient comfort in the intensive care unit
(ICU), especially in those undergoing mechanical ventilation. Sedation that is
too light or too deep can have important consequences, and therefore assessment
of the degree of sedation should be an important part of patient management.
Although there are many methods available to assess the degree of sedation, none
is ideal. Therefore, we developed a new sedation scale and analysed its clinical
impact in the management of patients undergoing mechanical ventilation. The study
comprised two consecutive phases. In the first phase, the medical team did not
use a sedation scale. In the second phase, the medical staff used the new
sedation scale, comprising five levels, depending on the perceived degree of
sedation: levels 1 and 2 = oversedation; levels 3 and 4 = correct sedation; and
level 5 = undersedation. There were no significant differences in mean or highest
levels between patients in the two phases (mean 2.89 (SD 0.11) vs 2.67 (0.13), P
= 0.22; highest 3.16 (0.11) vs 3.10 (0.14), P = 0.78). However, the lowest level
was significantly greater in patients in the second phase than in those in the
first phase (2.61 (0.11) vs 2.16 (0.13); P = 0.011), indicating that the number
of patients with excessive sedation was significantly reduced with the
introduction of this scale. Thus the use of this scale can have a real clinical
impact for patients undergoing mechanical ventilation, principally by avoiding
excessive sedation.
PMID- 10690130
TI - Haemodynamic effects of diaspirin crosslinked haemoglobin (DCLHb) given before
abdominal aortic aneurysm surgery.
AB - We studied 34 patients undergoing elective repair of an abdominal aortic aneurysm
under combined general anaesthesia and epidural block to evaluate the acute
effects of diaspirin crosslinked haemoglobin (DCLHb) 50, 100 and 200 mg kg-1 i.v.
Haemodynamic variables were measured continuously using pulmonary and radial
artery catheters, and oxygen delivery and consumption were calculated at regular
intervals. DCLHb was shown to be vasoactive, producing an increase in mean
arterial pressure of approximately 25% with each dose, with small decreases in
cardiac index and calculated oxygen delivery. These effects persisted beyond the
end of infusion and provided a degree of cardiovascular stability during the
operative procedure. The effects of DCLHb on oxygen consumption at these doses
were minimal.
PMID- 10690131
TI - High frequency jet ventilation and gas trapping.
AB - We have compared three types of high frequency jet ventilation (HFJV) with
conventional positive pressure ventilation in patients recovering from elective
coronary artery bypass surgery. Twelve patients were allocated randomly to
receive HFJV at ventilatory frequencies of 60, 100, 150 and 200 bpm from a
standard jet ventilator at either the proximal or distal airway (HFJV.p and
HFJV.d), or from a valveless high frequency jet ventilator acting as a pneumatic
piston (VPP). Trapped gas volume (Vtr), cardiac index (CI) and right ventricular
ejection fraction (RVEF) were measured. Vtr was related to the type of HFJV used
(P < 0.05) and ventilatory frequency (P < 0.05). CI decreased with increasing
rate of HFJV (P < 0.05) and there were significant differences between the three
types of HFJV (P < 0.05). RVEF showed a linear relationship with ventilatory
frequency (P < 0.05) decreasing most with the VPP. The decrease in RVEF was
associated with an increase in right ventricular end-systolic volume (P < 0.05)
suggesting that an increase in right ventricular afterload was the cause. The
same three types of HFJV were compared using a lung model with variable values of
compliance and resistance, to assess the impact of lung mechanics on gas trapping
(Vtr, ml). Lung model compliance (C) was set at 50 or 25 ml cm H2O-1 and
resistance (R) at 5 or 20 cm H2O litre-1 s, where values of 50 and 5,
respectively, are normal. Vtr increased with ventilatory frequency for all types
of jet ventilation (P < 0.05), varying with the type of jet ventilation used (P <
0.05).
PMID- 10690132
TI - Effect of omitting regular ACE inhibitor medication before cardiac surgery on
haemodynamic variables and vasoactive drug requirements.
AB - Adverse events during coronary artery bypass graft (CABG) surgery have been
described in patients receiving angiotensin converting enzyme (ACE) inhibitors,
including hypotension on induction of anaesthesia and an increase in
vasoconstrictor requirements after cardiopulmonary bypass (CPB). Omitting regular
ACE inhibitor medication before surgery may improve cardiovascular stability
during anaesthesia. We evaluated prospectively the effect of omitting regular ACE
inhibitor medication before CABG surgery on haemodynamic variables and use of
vasoactive drugs. We studied 40 patients with good left ventricular function,
allocated randomly to omit or continue ACE inhibitor medication before surgery.
Arterial pressure, cardiac output, systemic vascular resistance and use of
vasoactive drugs were recorded during anaesthesia and in the early postoperative
period. Patients who omitted their ACE inhibitors had greater mean arterial
pressure during the study and required less vasopressors during CPB. However,
these patients required more vasodilators to control hypertension after CPB and
in the early postoperative period. There was no difference in hypotension on
induction of anaesthesia or in the use of vasoconstrictors after CPB. We conclude
that omitting ACE inhibitors before surgery did not have sufficient advantage to
be recommended routinely.
PMID- 10690133
TI - Haemodynamic effects of rapacuronium in adults with coronary artery or valvular
disease.
AB - We have assessed the haemodynamic effects of rapacuronium (Org 9487) in adults
undergoing cardiac surgery and compared these with vecuronium and placebo. We
studied 56 adult patients undergoing coronary artery bypass grafting or valve
replacement surgery using a fentanyl-based anaesthetic technique. A pulmonary
artery flotation catheter was inserted before induction of anaesthesia. After
induction, tracheal intubation and stabilization of haemodynamic measurements,
subjects were allocated randomly to receive rapacuronium 1.5 mg kg-1 vecuronium
0.1 mg kg-1 or saline placebo. Haemodynamic measurements were made before drug
administration and 1, 3, 5 and 10, and if possible, 15 min after administration.
Rapacuronium was associated with statistically significant increases in heart
rate (17%) and cardiac index (15%) and decreases in mean arterial pressure (11%)
and systemic vascular resistance (18%), whereas vecuronium and placebo were
associated with significant decreases in heart rate only (14-15%) (P < 0.05). No
cutaneous signs of histamine release were observed. Clinically, the results were
within acceptable limits. Our results suggest that administration of rapacuronium
may be associated with significant changes in heart rate and arterial pressure in
patients undergoing coronary artery bypass grafting.
PMID- 10690134
TI - Antagonism of rapacuronium using edrophonium or neostigmine: pharmacodynamics and
pharmacokinetics.
AB - We have studied the pharmacodynamics and pharmacokinetics of rapacuronium (Org
9487) in 70 healthy patients. Neuromuscular transmission was monitored using TOF
stimulation of the ulnar nerve and mechanomyography of the adductor pollicis
muscle. Half of the patients were given a single dose of rapacuronium 1.5 mg kg-1
and the remainder rapacuronium 1.5 mg kg-1 with three incremental doses of 0.5 mg
kg-1, each given when T1/T0 had recovered to 25%. In all patients, neuromuscular
block was antagonized using neostigmine 0.05 mg kg-1 or edrophonium 1.0 mg kg-1
(allocated randomly), 2 min after the final dose of rapacuronium. All patients
developed complete block after rapacuronium 1.5 mg kg-1. Mean onset time was 66
(SD 24) s. In patients who received an antagonist 2 min after the first dose of
rapacuronium, time to recovery of T1/T0 to 25% was similar after neostigmine (9.8
(3.8) min) and edrophonium (10.3 (4.3) min): in patients who received incremental
doses of rapacuronium, spontaneous recovery of T1/T0 to 25% after the first dose
was 18.9 (4.7) min. In those who received an antagonist 2 min after the first
dose of rapacuronium, times to recovery of T4/T1 to 0.7 were also similar after
neostigmine (23.7 (7.7) min) and edrophonium (29.1 (10.7) min). After three
incremental doses of rapacuronium, there was a longer time to recovery of T1/T0 =
25% after neostigmine compared with edrophonium (5.1 (1.0) vs 3.3 (1.3) min; P <
0.05) but more rapid recovery to T1/T0 = 75% (10.1 (2.9) vs 16.8 (10.1) min; P <
0.05) and T4/T1 = 0.7 (19.8 (6.3) vs 35.1 (10.4) min; P < 0.05). A three
compartment pharmacokinetic model was justified. Typical values for clearance and
initial volume of distribution (V1) were 4.4 ml kg-1 min-1 and 94.8 ml kg-1,
respectively. In females, clearance was decreased by 38.5% compared with males
and V1 was decreased by 25% in patients aged more than 65 yr.
PMID- 10690135
TI - Sevoflurane anaesthesia causes a transient decrease in aquaporin-2 and impairment
of urine concentration.
AB - Sevoflurane anaesthesia is occasionally associated with polyuria, but the exact
mechanism of this phenomenon has not been clarified. Aquaporin-2 (AQP2) is an
arginine vasopressin (AVP)-regulated water channel protein localized to the
apical region of renal collecting duct cells and is involved in the regulation of
water permeability. To elucidate the effect of sevoflurane anaesthesia on urine
concentration and AQP2, we have compared serum and urinary concentrations of AVP,
AQP2 and osmolar changes during sevoflurane and propofol anaesthesia. General
anaesthesia was induced with sevoflurane or propofol in 30 patients for a variety
of major surgical procedures. Blood and urine samples were obtained from patients
at baseline, and 90 and 180 min after induction of anaesthesia. AVP and AQP2
concentrations were measured by radioimmunoassay. In both groups, plasma and
urinary concentrations of AVP increased similarly during anaesthesia although
plasma osmolality remained unchanged. Although urinary AQP2 excretion in the
propofol group increased together with changes in plasma and urinary AVP, urinary
AQP2 was significantly lower at 90 min in the sevoflurane group. Urine osmolality
in the sevoflurane group also showed a transient but significant decrease in
parallel with suppression of AQP2. Our data suggest that sevoflurane anaesthesia
transiently produced an impaired AQP2 response to an increase in intrinsic AVP.
PMID- 10690136
TI - The Haldane effect--an alternative explanation for increasing gastric mucosal
PCO2 gradients?
AB - When venous oxygen saturation increases as a result of increased blood flow,
changes in venous blood PCO2 and carbon dioxide content may differ because of the
Haldane effect. The Haldane effect may also explain increases in gastric mucosal
arterial PCO2 gradient despite major increases in splanchnic blood flow. We re
analysed data from 22 patients after cardiac surgery who were randomized to
receive either dobutamine or placebo, and a separate group of patients who
received dobutamine for low cardiac output (n = 6). Three different values of
gastric mucosal oxygen extraction at baseline were assumed (0.3, 0.5 and 0.7). In
nine of 14 patients with both increasing splanchnic blood flow and mucosal
arterial PCO2 gradient, an equal increase in mucosal and total splanchnic blood
flow, oxygen consumption and carbon dioxide production together with the Haldane
effect would have caused an increase in mucosal-arterial PCO2 gradients from a
mean value of 0.53 (SD 0.88) kPa at baseline to 0.68-0.82 (0.89-0.90) kPa (P <
0.01). In the remaining patients, disproportionate changes in flow and metabolism
must have been involved in addition to the Haldane effect. We conclude that
whenever major changes in mucosal tissue oxygen extraction are likely to occur,
an increase in the mucosal-arterial PCO2 gradient may be explained in part or
completely by the Haldane effect, and may therefore not reflect worsening
perfusion.
PMID- 10690137
TI - Continuous auditory monitoring--how much information do we register?
AB - We have studied response times of 30 anaesthetists to a standardized episode of
arterial oxygen desaturation in a simulated patient, randomized to the use of
either a fixed or variable pitch pulse oximeter. We wished to determine if a
variable auditory signal was important in detecting adverse events. A variable
pitch pulse signal had a shorter time to recognition of desaturation (P <
0.0001), with a mean response time of 32 s, compared with 129 s for the fixed
pitch signal.
PMID- 10690138
TI - Comparison of 0.25% S(-)-bupivacaine with 0.25% RS-bupivacaine for epidural
analgesia in labour.
AB - We have compared the efficacy of 0.25% S(-)-bupivacaine with 0.25% RS-bupivacaine
in providing epidural analgesia for labour in a randomized, multicentre, double
blind study. Analgesia was initiated with 10 ml of the study solution and
maintained with 10-ml top-ups. We studied 137 women and treatments were found to
be equivalent for onset, duration and quality of block. Median onset of pain
relief was 12 min for both drugs and median duration was 49 (range 3-129) min and
51 (7-157) min for S(-)-bupivacaine and RS bupivacaine, respectively. The
estimated treatment difference for duration of pain relief was -4 (90% CI -13, 6)
min. Thirty patients failed to achieve pain relief after the first injection (20
patients after S(-)-bupivacaine and 10 after RS-bupivacaine; P = 0.039). However,
median duration of pain relief from the first top-up was 82 (range 3-164) min for
S(-)-bupivacaine and 76 (22-221) min for RS-bupivacaine. There were no
significant differences in the quality of analgesia, as assessed by the
investigators. There were no significant differences in the extent of sensory
block, percentage of patients with motor block or incidence of adverse events.
PMID- 10690139
TI - Comparison of low-dose epidural with combined spinal-epidural analgesia for
labour.
AB - We have performed a randomized comparison of two low-dose epidural regimens for
analgesia in labour, differing only in the manner in which initial analgesia was
established. In the epidural (EPI) group, 484 women received a loading dose of 20
ml of 0.1% bupivacaine with fentanyl 2 micrograms ml-1. In the combined spinal
epidural (CSE) group, 524 women received a spinal injection of plain bupivacaine
2.5 mg with fentanyl 25 micrograms. In both groups, these initial doses were
followed by 0.1% bupivacaine with fentanyl 2 micrograms ml-1 infused at a rate of
12 ml h-1, with 20-ml top-ups for breakthrough pain. The groups were compared for
midwife assessment of analgesic efficacy, delivery mode, patient assessments of
first stage analgesia, second stage analgesia, overall analgesia, motor block and
complications. Midwives, who were not blinded to the treatment groups, assessed
61.6% of CSE as providing 'excellent' analgesia compared with 56.4% of epidurals
(P = 0.02). Patients assessed overall analgesia as 'excellent' in 74.8% of CSE
compared with 71.7% of epidurals (P = 0.14). Other comparisons between groups
revealed no differences. These findings may have been affected by an uneven
distribution of multiparous women between the groups (25% in the EPI group and
34.2% in the CSE group; P = 0.002). However, subgroup analysis of primiparous and
multiparous women did not alter the results.
PMID- 10690140
TI - Metoclopramide in the prevention of postoperative nausea and vomiting: a
quantitative systematic review of randomized, placebo-controlled studies.
AB - Metoclopramide has been used for almost 40 yr to prevent postoperative nausea and
vomiting (PONV). We have reviewed the efficacy and safety of metoclopramide for
the prevention of PONV. A systematic search (MEDLINE, EMBASE, manufacturers'
databases, hand searching, bibliographies, all languages, up to June 1998) was
performed for full reports of randomized comparisons of metoclopramide with
placebo in surgical patients. Relevant end-points were prevention of early PONV
(within 6 h after operation), late PONV (48 h) and adverse effects. Combined data
were analysed using relative benefit/risk and number-needed-to-treat/harm. In 66
studies, 3260 patients received 18 different regimens of metoclopramide, and 3006
controls received placebo or no treatment. There was no evidence of dose
responsiveness with oral, i.m., intranasal or i.v. metoclopramide in children and
adults. In adults, the best documented regimen was 10 mg i.v. There was no
significant anti-nausea effect. The numbers-needed-to-treat to prevent early and
late vomiting were 9.1 (95% confidence intervals 5.5-27) and 10 (6-41),
respectively. In children, the best documented regimen was 0.25 mg kg-1 i.v. The
number-needed-to-treat to prevent early vomiting was 5.8 (3.9-11). There was no
significant late anti-vomiting effect. Minor drug-related adverse effects
(sedation, dizziness, drowsiness) were not significantly associated with
metoclopramide. There was one adult who experienced extrapyramidal symptoms with
metoclopramide.
PMID- 10690141
TI - Dexamethasone reduces nausea and vomiting after laparoscopic cholecystectomy.
AB - We have evaluated the antiemetic effect of i.v. dexamethasone compared with
saline in the prevention of nausea and vomiting after laparoscopic
cholecystectomy. We studied 90 patients requiring general anaesthesia for
laparoscopic cholecystectomy, in a randomized, double-blind, placebo-controlled
study. The dexamethasone group (n = 45) received dexamethasone 8 mg i.v. and the
saline group received saline 2 ml i.v. at induction of anaesthesia. Anaesthesia
was maintained with isoflurane in oxygen. We found that 10% of patients in the
dexamethasone group compared with 34% in the saline group reported vomiting (P <
0.05). Of note, the total incidence of nausea and vomiting was 23% in the
dexamethasone group and 63% in the saline group (P < 0.001). We conclude that
dexamethasone 8 mg significantly decreased the incidence of nausea and vomiting
after laparoscopic cholecystectomy.
PMID- 10690142
TI - Hospital admission after day-case gynaecological laparoscopy.
AB - We have examined aspects of the anaesthetic technique that may influence the
likelihood of unplanned overnight hospital admission after ambulatory
gynaecological laparoscopy and have determined if any anaesthetically
controllable factors were involved. The retrospective audit involved 300
patients. All patients attended the day-case unit at the Liverpool Women's
Hospital between September 1996 and May 1997. One hundred ASA I-II patients who
had unplanned overnight admissions during this time were evaluated. For every
admitted patient, two similar patients who did not require admission were
studied. Variables such as patient age and anaesthetic technique were evaluated
by logistic regression. Our results indicated that postoperative emesis was the
commonest cause for admission. Significant factors increasing the likelihood of
unplanned admission included returning from the recovery unit after 15:00, use of
a laryngeal mask airway and undergoing diagnostic laparoscopy. Significant
factors reducing the likelihood of admission were the use of fentanyl and
rectally administered diclofenac.
PMID- 10690143
TI - Effects of tramadol on minimum alveolar concentration (MAC) of isoflurane in
rats.
AB - It has been suggested previously that tramadol increases central nervous system
activity and 'lightens' anaesthesia with volatile agents. We assessed the effects
of tramadol on the minimum alveolar concentration (MAC) of isoflurane in 56
Wistar rats, instrumented chronically with an arterial and central venous
catheter. The MAC of isoflurane was determined using the tail clamp method under
three conditions: (1) after injection of saline (control); (2) after
administration of tramadol 10 mg kg-1 i.v.; and (3) after administration of
morphine 1 mg kg-1 i.v. The studies were repeated after treatment with the
antagonists naloxone or yohimbine. Tramadol and morphine both reduced the MAC of
isoflurane from mean 1.38 (SEM 0.05)% to 1.22 (0.06)% and 1.17 (0.06)%,
respectively (P < 0.05). Concomitant administration of yohimbine did not abolish
this reduction in MAC. In contrast, after pretreatment with naloxone, tramadol
(1.47 (0.04)%) or morphine (1.38 (0.07)%) did not cause a reduction in the MAC of
isoflurane compared with controls (1.39 (0.06)%). We conclude that tramadol and
morphine reduced the MAC of isoflurane to a small but significant extent. For
both drugs, this effect was related to their action at opioid receptors.
PMID- 10690144
TI - Catecholaminergic activity and 3',5'-cyclic adenosine monophosphate
concentrations in the right ventricle after acute and chronic morphine
administration in the rat.
AB - We have examined possible regulation of norepinephrine and dopamine
concentrations and turnover in the right ventricle of the rat after acute
administration of saline i.p. or morphine 30 mg kg-1 i.p. to placebo (naive) or
morphine (tolerant) pretreated rats. We also assessed concentrations of 3',5'
cyclic adenosine monophosphate (cAMP) in the right ventricle after the same
treatments. Concentrations of catecholamines and their metabolites in the heart
were measured by high-pressure liquid chromatography with electrochemical
detection (HPLC/DE). Concentrations of cAMP in the heart were measured by
radioimmunoassay (RIA). Administration of morphine to naive rats did not modify
concentrations of norepinephrine (NE), normetanephrine (NMN) or NMN/NE ratio in
the right ventricle. However, dopamine concentrations increased whereas dopamine
turnover decreased. In addition, cAMP concentrations decreased after acute
administration morphine to naive rats. In rats pretreated with morphine
chronically, there was an increase in norepinephrine concentrations with no
change in normetanephrine concentrations or norepinephrine turnover after acute
injection of morphine. In contrast, dopamine turnover increased in the tolerant
groups after acute injection of saline or morphine compared with the nave group
given morphine, indicating that tolerance develops to the acute effects of the
opioid. Concentrations of cAMP increased after chronic morphine administration.
Our results demonstrate that chronic morphine pretreatment leads to up-regulation
of the cAMP system in the heart and suggest that this up-regulation may be
involved in the cellular mechanisms implicated in the adaptive changes of
dopaminergic neurones in the heart observed during chronic treatment with
morphine.
PMID- 10690145
TI - Ultrasound: an emerging role in anaesthesia and intensive care.
PMID- 10690146
TI - Oxygen administration and explicit memory: no improvement found in healthy
volunteers.
AB - It has been suggested that oxygen administration to healthy volunteers could
improve their memory. We tested this hypothesis with a twin, double crossover,
placebo-controlled study in 20 healthy non-smokers, allocated randomly to one of
two groups. Blinded to the nature of the gas, group A breathed air first then
oxygen on day 1, and then oxygen first, followed by air on day 2. Group B had all
exposures in reverse order. After each gas exposure a written memory test with a
list of 20 words was carried out and evaluated by a blinded observer. Recall
after oxygen exposure (mean 8.3 words) was not significantly different from that
after air exposure (mean 9 words).
PMID- 10690147
TI - Evaluation of pressure changes in a new design tracheal tube cuff, the Portex
Soft Seal, during nitrous oxide anaesthesia.
AB - We have measured pressure changes in a newly designed tracheal tube cuff, the
Portex Soft Seal, during nitrous oxide anaesthesia compared with a Mallinckrodt
Lo-Contour tube and a Portex Profile tube. The pressure increases in both control
groups were significantly greater than those with the new design (P < 0.0001 in
each case). The mean increase in pressure in the Mallinckrodt Lo-Contour tube
cuff was 9.9 (SD 3.4) mm Hg compared with 10.3 (1.8) mm Hg in the Portex Profile
tube cuff and 2.1 (1.5) mm Hg in the Portex Soft Seal tube cuff. We conclude that
the Portex Soft Seal cuff prevented a significant increase in intracuff pressure
during nitrous oxide anaesthesia.
PMID- 10690148
TI - Posterior epidural space depth: safety of the loss of resistance and hanging drop
techniques.
AB - We have compared skin to epidural space distance (SED) and tip to tip distance
(TTD), a measure of posterior epidural space depth (PESD), in 40 patients with a
27-gauge Whitacre needle after identification of the epidural space using the
hanging drop (HD) or loss of resistance (LOR) to air technique. After the LOR
technique, TTD was found to be 2 mm greater than that after the HD technique,
whereas SED was the same. We conclude that identification of the epidural space
can be performed successfully with both techniques, but with a diminished risk of
dural damage after LOR compared with the HD technique.
PMID- 10690149
TI - Self-prepared heparinized syringes for measuring ionized magnesium in critical
care patients.
AB - We have compared ionized magnesium assays in the Nova 8 electrolyte analyser
using dry balanced heparinized syringes and self-prepared heparinized syringes.
Thirty blood specimens were obtained into syringes either operator-prepared with
liquid sodium heparin or commercially manufactured dry balanced heparinized
syringes. There was a good correlation between results from the two syringes. The
mean difference between sampling methods was 0.01 mmol litre-1 (95% confidence
index -0.05 to 0.08 mmol litre-1). The correlations for sodium, potassium and
ionized calcium assays were similarly close. The relationship between sampling
methods was close enough to justify the clinical use of self-prepared syringes,
with potential economies in clinical costs.
PMID- 10690150
TI - Ondansetron and droperidol in the prevention of postoperative nausea and
vomiting.
AB - We have performed a prospective, randomized, double-blind clinical study to
assess the efficacy of ondansetron, droperidol, or both, in preventing
postoperative emesis. We studied 242 patients undergoing biliary or
gynaecological surgery under general anaesthesia. Shortly before induction of
anaesthesia, patients received: saline i.v. (group I, n = 62); droperidol 2.5 mg
i.v. (group 2, n = 60); ondansetron 4 mg i.v. (group 3, n = 57); or droperidol
2.5 mg with ondansetron 4 mg i.v. (group 4, n = 63). Nausea occurred in 45%, 37%,
32% and 29% (P = 0.234) and vomiting in 23%, 17%, 9% and 5% (P = 0.016) of
patients in groups 1, 2, 3 and 4, respectively, during the first 24 h. Groups 2
and 4 had greater sedation scores than group 1 during the first 3 h (P < 0.01).
We conclude that both droperidol and ondansetron showed a significant antiemetic
effect, ondansetron was not significantly better than droperidol, and the
combination of droperidol and ondansetron was better than droperidol but no
better than ondansetron alone.
PMID- 10690151
TI - Development of rapid atrial fibrillation with a wide QRS complex after
neostigmine in a patient with intermittent Wolff-Parkinson-White syndrome.
AB - We report the case of a 67-yr-old man with intermittent Wolff-Parkinson-White
(WPW) syndrome in whom neostigmine produced life-threatening tachyarrhythmias.
The patient was scheduled for microsurgery for a laryngeal tumour. When he
arrived in the operating room, the electrocardiogram showed normal sinus rhythm
with a rate of 82 beat min-1 and a narrow QRS complex which remained normal
throughout the operative period. On emergence from anaesthesia, the sinus rhythm
(87 beat min-1) changed to atrial fibrillation with a rate of 80-120 beat min-1
and a normal QRS complex. We did not treat the atrial fibrillation because the
patient was haemodynamically stable. Neostigmine 1 mg without atropine was then
administered to antagonize residual neuromuscular block produced by vecuronium.
Two minutes later, the narrow QRS complexes changed to a wide QRS complex
tachycardia with a rate of 110-180 beat min-1, which was diagnosed as rapid
atrial fibrillation. As the patient was hypotensive, two synchronized DC
cardioversions of 100 J and 200 J were given, which restored sinus rhythm. No
electrophysiological studies of anticholinesterase drugs have been performed in
patients with WPW syndrome. We discuss the use of these drugs in this condition.
PMID- 10690152
TI - Paravertebral block in the management of liver capsule pain after blunt trauma.
AB - We present a case of liver capsule pain after blunt abdominal trauma. The patient
was unable to tolerate patient-controlled i.v. opioids, and epidural infusion of
local anaesthetic was considered undesirable because of the potential risk of
complications. Pain was managed successfully with paravertebral infusion of local
anaesthetic at the right T10 level. Innervation of the liver and possible
mechanisms of visceral pain processing are discussed.
PMID- 10690153
TI - Opioid-induced pruritus: repeated vs single dose ondansetron administration in
preventing pruritus after intrathecal morphine.
PMID- 10690154
TI - Effect of rocuronium compared with succinylcholine on IOP.
PMID- 10690155
TI - Effect of rocuronium compared with succinylcholine on IOP.
PMID- 10690156
TI - Intraoperative therapeutic suggestions.
PMID- 10690157
TI - Glucose utilization dynamics and food intake.
PMID- 10690158
TI - Wheat bran supplementation does not affect biochemical markers of bone turnover
in young adult women with recommended calcium intake.
AB - We investigated the effect of wheat bran on biochemical indicators of Ca and bone
metabolism in nineteen healthy women, aged 25.5 (SE 0.9) years. Subjects received
six wheat bran biscuits or six white flour biscuits per day for a period of 4
weeks (crossover). Wheat bran consumption increased fibre intake from 17.7 (SE
1.3) to 29.6 (SE 1.3) g/d (7 d food record) and enhanced P intake from 1225 (SE
59) mg/d to 1663 (SE 65) mg/d; P < 0.001. Mean daily Ca intake during wheat bran
consumption (1110 (SE 82) mg/d) significantly (P = 0.008) exceeded Ca ingestion
during the white flour period (955 (SE 67) mg/d). Wheat bran increased the number
of defecations per week from 7.9 (SE 0.8) to 12.2 (SE 1.4) (P = 0.0018). Urinary
Ca excretion over 24 h significantly (P = 0.021) decreased from 473 (SE 53)
mumol/mmol creatinine (control period) to 339 (SE 37) mumol/mmol creatinine
(wheat bran period). Serum 25-hydroxyvitamin D, 2 h fasting urinary Ca/creatinine
excretions and 24 h urinary P excretion remained constant. No differences in
serum levels of carboxy-terminal propeptide of type I procollagen (biomarker of
bone formation) or in 2 h fasting urinary hydroxyproline/creatinine excretions
(biomarker of bone resorption) were observed at the end of the two cycles of
dietary supplementation. We conclude that a high fibre intake of approximately 30
g/d has no significant adverse effects on bone turnover in subjects with Ca
intakes above 1000 mg/d and that the reduction in 24 h urinary Ca excretion is
most probably the result of an adaptation process, induced by a decrease in net
absorbed Ca.
PMID- 10690159
TI - Blood glucose and meal patterns in time-blinded males, after aspartame,
carbohydrate, and fat consumption, in relation to sweetness perception.
AB - In a study of the impact of aspartame, fat, and carbohydrate on appetite, we
monitored blood glucose continuously for 431 (SE 16) min. Ten healthy males (19
31 years) participated in three time-blinded visits. As blood glucose was
monitored, appetite ratings were scored at randomized times. On the first meal
initiation, volunteers consumed one of three isovolumetric drinks (aspartame, 1
MJ simple carbohydrate, and 1 MJ high-fat; randomized order). High-fat and high
carbohydrate foods were available ad libitum subsequently. Blood glucose patterns
following the carbohydrate drink (+1.78 (SE 0.28) mmol/l in 38 (SE 3) min) and
high-fat drink (+0.83 (SE 0.28) mmol/l in 49 (SE 6) min) were predictive of the
next intermeal interval (R 0.64 and R 0.97 respectively). Aspartame ingestion was
followed by blood glucose declines (40% of subjects), increases (20%), or
stability (40%). These patterns were related to the volunteers' perception of
sweetness of the drink (R 0.81, P = 0.014), and were predictive of subsequent
intakes (R -0.71, P = 0.048). For all drinks combined, declines in blood glucose
and meal initiation were significantly associated (chi 2 16.8, P < 0.001), the
duration of blood glucose responses and intermeal intervals correlated
significantly (R 0.715, P = 0.0001), and sweetness perception correlated
negatively with hunger suppression (R -0.471, P = 0.015). Effects of fat,
carbohydrate, and aspartame on meal initiation, meal size, and intermeal interval
relate to blood glucose patterns. Varied blood glucose responses after aspartame
support the controversy over its effects, and may relate to sweetness perception.
PMID- 10690160
TI - The effects of sucrose and maize oil on subsequent food intake and mood.
AB - The effects of sucrose and oil preloads were explicitly compared in a single
blind controlled trial using a between-subjects design. Eighty adult subjects
(forty-three male, thirty-seven female) aged 18-50 years received at 11.00 hours
one of four yoghurt preloads. All were 80 g low-fat, unsweetened yoghurt (188
kJ), containing additionally (1) saccharin (control, 23 kJ), or (2) 40 g sucrose
(859 kJ), (3) 40 g maize oil (1569 kJ), (4) 20 g sucrose, 20 g maize oil (1213
kJ). Subjects were normal eaters and of normal weight (male mean weight: 68.8 (SD
3.2) kg, BMI 21.8 (SD 1.6) kg/m2; female mean weight: 53.7 (SD 5.1) kg, BMI 20.4
(SD 1.2) kg/m2). Food intake was measured with a food diary and mood with ten
single Likert scales. ANOVA was conducted using preload type (saccharin, sucrose,
oil, sucrose + oil), sex (male, female) and early v. late breakfast times as
factors. Mood was analysed using the same design, with time of rating (immediate,
60 min, 120 min) as an additional factor. Men ate more after the saccharin
preload than after the other preloads, but did not vary the time of their next
solid food. Women increased the intermeal interval only after the oil preload,
which also had the highest energy content value, but did not vary the energy
content of their next solid food. The saccharin preload decreased rated tiredness
at 2 h compared with the sucrose preload, possibly due to its lower energy
content. The preloads containing sucrose or sucrose + oil increased calmness
between 1 and 2 h afterwards, compared with the saccharin preload. It is
concluded that both sucrose and oil increase the intermeal interval in men, but
that women are less sensitive to preloading. The mood effects suggest that
tiredness after carbohydrate at 2 h may in part be a decrease in rated energy
compared with the increased rated energy found after a preload with low energy
content. Carbohydrate may genuinely increase calmness. These effects apply to non
restrained eaters of normal weight.
PMID- 10690161
TI - Carbohydrate intake improves cognitive performance of stress-prone individuals
under controllable laboratory stress.
AB - Cognitive performance has been found to decline after exposure to stress,
particularly in stress-prone subjects. The present study investigated whether a
carbohydrate-rich, protein-poor (CR/PP) diet, which may enhance cerebral
serotonin function in stress-prone subjects due to increases in the available
tryptophan, improves the performance of stress-prone subjects after exposure to
acute laboratory stress. Twenty-two high-stress-prone (HS) subjects and twenty
one low-stress-prone (LS) subjects aged between 19 and 26 years performed a
memory scanning task after controllable and uncontrollable stress, following
either a CR/PP diet or a protein-rich, carbohydrate-poor (PR/CP) isoenergetic
diet. Uncontrollable stress reduced feelings of control (F(1,38) 9.30; P =
0.004), whereas pulse rate and skin conductance increased after both stress tasks
(F(1,38) 78.34; P = 0.0005 and F(1,37) 83.16; P = 0.0004). Diet, stress-proneness
and stress-controllability interacted (F(1,36) 9.46; P = 0.004) in such a way
that performance in HS subjects was better with the CR/PP diet than with the
PR/CP diet, but only after controllable stress. As the CR/PP diet has been found
to increase the plasma tryptophan:large neutral amino acids ratio, indicating an
increased availability of cerebral tryptophan and, thus, higher serotonin levels,
it appears that there may be an increased availability of brain serotonin in HS
subjects after controllable laboratory stress.
PMID- 10690162
TI - The effect of palm oil, lard, and puff-pastry margarine on postprandial lipid and
hormone responses in normal-weight and obese young women.
AB - Only a few studies have been published on the postprandial effects of different
fatty acids in obese subjects. Therefore, the present study investigated the
effects of three test meals containing palm oil (PO), lard (LD), or puff-pastry
margarine (PPM), all normal dietary ingredients, on postprandial lipid and
hormone responses in normal-weight and obese young women. The study was performed
as a randomized, crossover design. The fats differed in the content of palmitic
acid, stearic acid, and trans monounsaturated fatty acids allowing a dietary
comparison of different 'solid' fatty acids. The obese women had significantly
higher fasting concentrations and postprandial responses of plasma total
triacylglycerol (TAG), chylomicron-TAG, and insulin compared with the normal
weight women but there was no significant difference in the postprandial
responses between the three test meals. The obese women had fasting
concentrations of leptin four times greater than the normal-weight women. There
were no postprandial changes in the concentrations of leptin. The fasting
concentrations of HDL-cholesterol were significantly lower in the obese women
than in the normal-weight women, whereas there was no significant difference
between the two groups in the concentrations of total cholesterol or LDL
cholesterol. These results provide evidence that obese women have exaggerated
lipid and hormone responses compared with normal-weight women but the different
contents of saturated and trans monounsaturated fatty acids provided by PO, LD,
and PPM have no effect in either group.
PMID- 10690163
TI - Incorporation and washout of orally administered n-3 fatty acid ethyl esters in
different plasma lipid fractions.
AB - The aim of the present study was to quantify the incorporation of
eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids
after oral administration of n-3 fatty acid ethyl esters, since little is known
about the rate and pattern of incorporation into plasma lipid fractions. In
addition, we aimed to obtain preliminary information regarding EPA half-life,
which is needed to establish an optimal dosing schedule. Five healthy volunteers
ingested two 8.5 g doses of n-3 fatty acid ethyl esters daily for 7 d, supplying
6.0 g EPA/d and 5.3 g DHA/d. The fatty acid compositions of plasma phospholipids
(PL), cholesteryl esters (CE) and triacylglycerols (TAG) were determined during
supplementation and during a washout period of 7 d. Half-lives of EPA and DHA
were calculated. The proportion of EPA in PL showed a 15-fold increase after 7 d
(P < 0.001), while DHA showed a smaller increase (P < 0.01). In CE, EPA also
increased (P < 0.05), while DHA did not increase at all. Remarkably,
incorporation of DHA into TAG was even higher than that of EPA. Half-life of EPA
in PL ranged from 1.63 to 2.31 d (mean 1.97 (SE 0.15) d), whereas mean half-life
of EPA in CE was 3.27 (SE 0.56) d. In three subjects, washout of EPA and DHA from
TAG seemed to follow a bi-exponential pattern, with a short half-life (< 1 d) in
the initial phase and a half-life of several days in the second phase. In
conclusion, EPA ethyl esters are rapidly incorporated into plasma lipids,
especially into PL. The relatively long half-life of EPA in plasma would permit a
dosing schedule with intervals of > or = 12 h in supplementation studies.
PMID- 10690164
TI - The effect of a model melanoidin mixture on faecal bacterial populations in
vitro.
AB - The Maillard reaction produces coloured, macromolecular materials (melanoidins)
in a variety of foods, on heating. Significant quantities may enter the human gut
on a daily basis, but there is little information on their metabolism in the
human colon. As the large bowel contains a diverse population of bacteria
involved in normal bowel function, it is possible that melanoidins are
metabolized therein. Depending on the bacteria involved, there may be disease or
health implications. The aim of the present study was to use in vitro models to
determine the digestibility of melanoidins and the effect of melanoidins on
colonic bacteria in the gastrointestinal tract. Melanoidins were prepared and the
effects of simulated upper-gut secretions on their stability determined in a
model system. The effects of faecal bacteria were also determined, in batch
culture, with a combination of phenotypic and genotypic (probes) criteria being
used to identify the microbial diversity involved. Simulation of peptic and
pancreatic digestion showed that the melanoidins did not produce detectable
amounts of low-molecular-mass degradation products. However, melanoidins affected
the growth of gut bacteria during mixed culture growth. The effect was to cause a
non-specific increase in the anaerobic bacteria enumerated. This in vitro study
indicates that melanoidins can affect the growth of human large-bowel bacteria
and serves to demonstrate possible effects that may occur in vivo. Given the
large and varied number of food items that contain Maillard reaction products,
this may have relevance for lower-gut health.
PMID- 10690165
TI - Involvement of lipoic acid in plasma metabolites, hepatic oxygen consumption, and
metabolic response to a beta-agonist in broiler chickens.
AB - The present study was conducted to determine the role of alpha-lipoic acid (LA)
in plasma metabolites, hepatic O2 consumption, and beta-adrenergic response in
broilers. In Expt 1, 12-d-old female broiler chicks were divided into three
dietary groups and fed on diets with or without LA (5 or 50 mg/kg) until 4 or 6
weeks of age, as a 2 x 3 factorial arrangement. The dietary LA had no effect on
growth rates (body weight, abdominal fat, breast muscle, and liver). The higher
level of LA increased plasma non-esterified fatty acid and decreased plasma
triacylglycerol concentrations only at 6 weeks of age. A 42% increase in hepatic
respiration was observed in the 4-week-old chickens given 50 mg LA/kg diet. In
Expt 2, 3-d-old female broiler chicks were treated with or without dietary LA at
50 mg/kg. At 30 and 31 d old, isoproterenol (2 mg/kg body weight per h) was
continuously infused into a wing vein for 2 h, and changes in plasma glucose,
triacylglycerol, and non-esterified fatty acid concentrations were analysed.
Isoproterenol increased plasma glucose over basal levels maximally at 60 min.
Furthermore, the glucose increase in the LA-treated chickens was 35% greater than
that of the controls at this time. Plasma non-esterified fatty acid and
triacylglycerol concentrations were decreased by the isoproterenol infusion,
regardless of LA administration. Therefore, the present study suggests that
dietary LA has repartitioning effects on energy metabolism in chickens (although
this depends on age-related metabolic state) and is a possible facilitator in the
beta-adrenergic response of plasma glucose to a beta-agonist.
PMID- 10690166
TI - Prostate cancer prevention: review of target populations, pathological
biomarkers, and chemopreventive agents.
PMID- 10690167
TI - The neuropathology of the vegetative state after head injury.
PMID- 10690168
TI - Clinical application of the Quantiplex HCV RNA 2.0 and Amplicor HCV Monitor
assays for quantifying serum hepatitis C virus RNA.
AB - AIM: To compare the performance characteristics and clinical application of two
different technologies for quantifying serum hepatitis C virus (HCV) RNA levels.
METHODS: HCV RNA was quantified by Amplicor HCV Monitor assay (Amplicor) and
Quantiplex HCV RNA 2.0 assay (bDNA-2) in 119 sera from 107 HCV infected patients.
RESULTS: Both assays had similar sensitivity (79.4% for Amplicor; 86.0% for bDNA
2), acceptable coefficients of variation (5.3% in Amplicor; 2.6% in bDNA-2), and
good linearity (r2 > or = 0.98). There was a positive correlation between
quantification values of both methods (r = 0.683, p < 0.001). The Amplicor values
were on an average 1.76 log lower than bDNA-2 results. Male subjects and HCV
genotype 1b were significantly associated with higher viral load determined by
Amplicor, but not with viral load measured by bDNA-2. In 70 chronic HCV infected
patients treated with interferon alfa, mean (SD) pretreatment viral load in 27
complete responders (3.47 (0.84) logs for Amplicor, 5.63 (0.58) for bDNA-2) was
significantly lower than in non-responders (4.43 (1.01) logs for Amplicor, 6.10
(0.67) logs for bDNA-2; p < 0.001). Cut off points of 3.9 logs for Amplicor and
5.8 logs for bDNA-2 were determined to be the best for predicting response to
interferon alfa, giving acceptable sensitivity (70.4%, 74.1%), specificity
(72.1%, 65.1%), and accuracy (71.4%, 68.6%), respectively. CONCLUSIONS: Both the
Amplicor and bDNA-2 assays are clinically useful methods for HCV RNA
quantification and are reliable for predicting the outcome of treatment, despite
differences in absolute quantification values and in the correlation between HCV
genotypes and viral load.
PMID- 10690169
TI - Drug resistance in Campylobacter jejuni, C coli, and C lari isolated from humans
in north west England and Wales, 1997.
AB - AIMS: To test the sensitivity of strains of Campylobacter species isolated from
humans in England and Wales against a range of antimicrobial agents for the
purpose of monitoring therapeutic efficacy and as an epidemiological marker.
METHODS: An agar dilution breakpoint technique was used to screen isolates
against ampicillin, chloramphenicol, gentamicin, kanamycin, neomycin,
tetracycline, nalidixic acid, ciprofloxacin, and erythromycin. Minimal inhibitory
concentrations (MIC) were also determined for a sample of quinolone resistant
strains. RESULTS: Approximately 50% of strains tested were resistant to at least
one drug. Strains which were resistant to four or more of the drugs tested were
classified as multiresistant; this occurred in 11.3% of C jejuni, 19.9% of C
coli, and 63.6% of C lari. Resistance to erythromycin occurred in 1.0% of C
jejuni and 12.8% of C coli. Resistance to quinolones occurred in 12% of strains,
with a ciprofloxacin MIC of > 8 mg/l and a nalidixic acid MIC of > 256 mg/l; a
further 4% of strains had intermediate resistance with a ciprofloxacin MIC of
between 0.5 and 2 mg/l (fully sensitive strains, 0.25 mg/l or less) and a
nalidixic acid MIC of between 32 and 64 mg/l (fully sensitive strains, 8 mg/l or
less). CONCLUSIONS: Resistance to quinolones in campylobacters from human
infection may relate to clinical overuse or use of fluoroquinolones in animal
husbandry. Both veterinary and clinical use should be reconsidered and
fluoroquinolone drugs used only as a treatment for serious infections requiring
hospital admission. Erythromycin resistance is still rare in C jejuni but much
more common in C coli.
PMID- 10690170
TI - The pattern of involvement of the gastric mucosa in lymphocytic gastritis is
predictive of the presence of duodenal pathology.
AB - AIM: To determine whether the pattern of involvement of the gastric mucosa in
lymphocytic gastritis is predictive of the presence or absence of duodenal
pathology. METHODS: 50 cases (M:F, 26:24; median age 57 years) diagnosed as
lymphocytic gastritis between 1986 and 1998 with concurrent duodenal (D2)
biopsies were identified from a computer search of the pathology records and
validated by counting gastric intraepithelial lymphocytes. Gastric and duodenal
intraepithelial lymphocyte counts were performed on haematoxylin and eosin (H&E)
and anti-CD3 stained sections. D2 biopsies were assessed for villous atrophy and
chronic inflammatory cell infiltration by subjective grading, and gastritis was
classified and graded according to the updated Sydney system. A case was
designated corpus predominant when the corpus chronic inflammation grade exceeded
that of the antrum. If it was less, then the case was antrum predominant, and if
they were equal it was diffuse (pan-) gastritis. The ratio between the corpus and
antral intraepithelial lymphocyte count in individual patients was calculated.
RESULTS: Of 50 cases of lymphocytic gastritis, 21 were classified as corpus
predominant. With one exception (a case of mild villous atrophy), all were
accompanied by normal duodenal morphology. Cases with a corpus predominant
gastritis had median duodenal intraepithelial lymphocyte counts of 19 (H&E) and
14.1 (CD3), whereas 29 subjects with an antrum predominant or diffuse gastritis
had median counts of 39.9 (H&E) and 37.9 (CD3). Fifteen of these 29 cases (52%)
showed villous atrophy; all were graded as moderate or severe. Patients with any
degree of villous atrophy had a mean corpus/antrum intraepithelial lymphocyte
ratio (H&E) of 0.59 (representing antral predominance), while those with normal
duodenal morphology had a ratio of 2.39 (p < 0.0001). CONCLUSIONS: The pattern of
involvement of gastric mucosa in lymphocytic gastritis is closely related to the
associated duodenal pathology. Those with the corpus predominant form are
unlikely to have duodenal pathology, while those with an antral predominant or
diffuse form should have distal duodenal biopsies taken to exclude villous
atrophy.
PMID- 10690171
TI - The contribution of MIB 1 in the accurate grading of vulvar intraepithelial
neoplasia.
AB - AIM: To determine the interobserver variation in scoring presence and grade of
vulvar intraepithelial neoplasia (VIN) in haematoxylin/eosin (H/E) slides, MIB 1
slides, and the combined use of H/E and MIB 1 slides. METHODS: 10 slides were
stained with H/E and MIB 1 with each of the following diagnoses: normal vulvar
skin, VIN 1, VIN 2, and VIN 3. Six observers first scored the H/E slides
separately from the MIB 1 slides and second the combined H/E and MIB 1 slides.
RESULTS: Unweighted group kappa for MIB 1 was 0.62 and the weighted group kappa
was 0.91. This was significantly better than the unweighted group kappa for H/E
slides (0.47, p = 0.023) as well as the weighted group kappa for H/E slides
(0.82, p = 0.014). There was no improvement by the combined use of H/E and MIB 1
slides. VIN 2 is far less confused with VIN 3 in the combined use of H/E and MIB
1 slides (9%) than in H/E slides (38%) (p = 0.007). There is a tendency to grade
VIN in a two tailed grading system rather than a three tailed grading system,
which became more apparent with the combined use of H/E and MIB 1 slides.
CONCLUSIONS: The interobserver variation with sole use of MIB 1 is better than
with the use of H/E stain in VIN. The use of MIB 1 in grading VIN diminishes
confusion between VIN 2 and VIN 3 fourfold. A two tailed grading system for VIN
seems already to work in daily practice.
PMID- 10690172
TI - Effect of using templates on the information included in histopathology reports
on specimens of uterine cervix taken by loop excision of the transformation zone.
AB - AIM: To determine the change in information relayed from histopathologists to
clinicians by using templates for reporting specimens of uterine cervix sampled
by loop excision of the transformation zone (LETZ). METHODS: Minimum datasets for
the information required from LETZ specimens received from the colposcopy clinic,
Royal Infirmary, Edinburgh, were incorporated into templates on the clinical
service computer (Pinnacle) of the pathology department, University of Edinburgh.
Pathologists completed hard copy versions, which were transcribed into the
computer templates for report generation. The effect of the changes on the
quality of the pathology reports was studied. The number of cases in which each
item in the dataset received comment in template generated reports was compared
with that in traditional prose reports compiled before the use of the templates
and in prose reports issued after the introduction of the templates.
Questionnaire studies were undertaken of clinicians' and pathologists' opinions
of the template reports. RESULTS: In the template reports nearly all items
received comment in almost 100% of cases. In the prose reports issued both before
and after the templates were in use, most items were mentioned in a significantly
lower proportion of cases. Clinicians thought the template reports were clearer
and the information could be more readily assimilated than from the prose
versions. CONCLUSIONS: The use of template reports in these types of specimen
allowed more consistent and detailed information transfer. The change appeared to
result from the use of the templates rather than from increased awareness of the
items to be reported.
PMID- 10690173
TI - Papillary hidradenoma: immunohistochemical analysis of steroid receptor profile
with a focus on apocrine differentiation.
AB - AIM: To make a quantitative evaluation by image analysis of oestrogen receptors,
progesterone receptors, and androgen receptors in papillary hidradenomas and
anogenital sweat glands. METHODS: 20 papillary hidradenomas and the anogenital
sweat glands detected in surgical specimens selected from 10 vulvectomies for
squamous carcinoma, eight haemorrhoidectomies, and one anal polypectomy, all from
female patients, were investigated by the avidinstreptavidin peroxidase testing
system. RESULTS: 90% of papillary hidradenomas and almost all the anogenital
sweat glands showed immunoreactivity for oestrogen receptor and, more weakly, for
progesterone receptor, with immunolabelled nuclear area ranging from 10% to 90%.
Conversely conventional sweat glands did not show any nuclear staining.
Overexpression of androgen receptors occurred in 20% of papillary hidradenomas,
with nuclear staining strictly bordering papillary epithelium with apocrine
differentiation. There was no immunoreactivity for androgen receptors in
anogenital sweat glands. CONCLUSIONS: Oestrogen and progesterone receptors seem
to represent reliable markers for differentiating between anogenital sweat glands
and conventional sweat glands, and a further link to explain why papillary
hidradenomas occur almost exclusively in the female anogenital region. Positivity
for oestrogen/progesterone receptors suggests that epithelia either of anogenital
sweat glands or of papillary hidradenomas are controlled by ovarian steroid
hormones. Androgen receptor nuclear staining of the epithelium with apocrine
differentiation in vulvar papillary hidradenoma strengthens its homology with
breast duct papilloma.
PMID- 10690174
TI - Possible involvement of IL-12 expression by Epstein-Barr virus in Sjogren
syndrome.
AB - AIM: To determine the correlation between interleukin 12 (IL-12) expression and
Epstein-Barr virus (EBV) in Sjogren syndrome. METHODS: Indirect
immunohistochemical technique, enzyme linked immunosorbent assay (ELISA), and
immunoblot analysis were used to investigate IL-12 expression by EBV activation,
using 13 surgical specimens and four B cell lines. RESULTS: Marked expression of
IL-12 was found in the epithelial cells and the infiltrating B cells of salivary
gland tissues from patients with Sjogren syndrome (six of 10 cases), but not in
those from normal individuals (none of three cases). A striking topographic
correlation between IL-12 and EBV was found. In addition, levels of IL-12
production by B cell lines were clearly enhanced by EBV activation in vitro.
CONCLUSIONS: IL-12 expression closely reflects the intracellular event of EBV
activation in Sjogren syndrome, and may contribute to the T helper cell type 1
(Th1) cytokine overexpression seen in this disease.
PMID- 10690175
TI - Immunohistochemical localisation of androgen receptor in apocrine metaplasia and
apocrine adenosis of the breast: relation to oestrogen and progesterone
receptors.
AB - AIM: To investigate the receptor status of the sex steroid hormones in apocrine
metaplasia of the breast. METHODS: 82 cases of apocrine metaplasia, including 18
of the rare lesion apocrine adenosis, were studied immunohistochemically for the
expression of androgen receptor, oestrogen receptor, and progesterone receptor
proteins on formalin fixed, paraffin embedded tissue sections. The standard
avidin biotin complex (ABC) technique was followed and appropriate positive and
negative controls were used. RESULTS: All the studied cases (82/82) were positive
for androgen receptor, but were negative for oestrogen receptor and progesterone
receptor. CONCLUSIONS: Apocrine metaplastic epithelium, unlike the normal breast
epithelium, is responsive to androgens, through androgen receptors, rather than
to the female sex hormones. This may have clinical implications.
PMID- 10690176
TI - A primary care evaluation of three near patient coagulometers.
AB - AIM: To compare the reliability and relative costs of three international
normalised ratio (INR) near patient tests. MATERIALS: Protime (ITC Technidyne),
Coaguchek (Boehringer Mannheim), and TAS (Diagnostic Testing). METHODS: All
patients attending one inner city general practice anticoagulation clinic were
asked to participate, with two samples provided by patients not taking warfarin.
A 5 ml sample of venous whole blood was taken from each patient and a drop
immediately added to the prepared Coaguchek test strip followed by the Protime
cuvette. The remainder was added to a citrated bottle. A drop of citrated blood
was then placed on the TAS test card and the remainder sent to the reference
laboratory for analysis. Parallel INR estimation was performed on the different
near patient tests at each weekly anticoagulation clinic from July to December
1997. RESULTS: 19 patients receiving long term warfarin treatment provided 62 INR
results. INR results ranged from 0.8-8.2 overall and 1.0-5.7 based on the
laboratory method. Taking the laboratory method as the gold standard, 12/62
results were < 2.0 and 2/62 were > 4.5. There were no statistical or clinically
significant differences between results from the three systems, although all near
patient tests showed slightly higher mean readings than the laboratory, and 19
24% of tests would have resulted in different management decisions based on the
machine used in comparison with the laboratory INR value. The cost of the near
patient test systems varied substantially. CONCLUSIONS: All three near patient
test systems are safe and efficient for producing acceptable and reproducible INR
results within the therapeutic range in a primary care setting. All the systems
were, however, subject to operator dependent variables at the time of blood
letting. Adequate training in capillary blood sampling, specific use of the
machines, and quality assurance procedures is therefore essential.
PMID- 10690177
TI - Cutaneous Scedosporium apiospermum infection in an immunocompromised patient.
AB - Scedosporium apiospermum infection occurred in the left forearm of a patient who
was taking oral prednisolone for pulmonary fibrosis. The infection appeared to
follow a scratch from a blackcurrant bush. This is the first reported case in the
United Kingdom of a cutaneous infection from Scedosporium apiospermum in an
immunocompromised patient.
PMID- 10690178
TI - CD10 positive thyroid marginal zone non-Hodgkin lymphoma.
AB - A 72 year old woman presented with swelling of the right lobe of her thyroid
gland. Fine needle aspiration and flow cytometry showed a clonal population of B
cells expressing CD10 and a diagnosis of follicle centre cell lymphoma was made.
Subsequent excision of the thyroid showed the typical histological features of a
marginal zone non-Hodgkin lymphoma. Polymerase chain reaction showed no evidence
of t (14;18). Immunohistochemistry confirmed CD10 positivity and LN1 (CDw75)
expression. This is only the second report of aberrant expression of CD 10 by a
marginal zone lymphoma.
PMID- 10690179
TI - Deterioration in performance in obtaining bone marrow trephine biopsy cores from
children. European Neuroblastoma Study Group.
AB - AIM: To complete an audit of bone marrow trephine biopsy adequacy in children
MATERIAL: 605 specimens from children with neuroblastoma submitted by 25 centres
were reviewed centrally. This reassessment ran between January 1995 and August
1998. RESULTS: 25% of specimens (95% confidence interval (CI) 21% to 29%) were
inadequate compared with 17% (95% CI 14% to 20%) in a previous study. Variation
between individual centres' performance remains high (5-54% of specimens
inadequate). Had five centres performed as well as previously, the inadequate
biopsy rate would have been unchanged from that found in the previous study.
There was no important improvement in any centre's performance. Earlier
suggestions about change in practice have had no discernible impact on centres'
ability to obtain adequate bone marrow trephine biopsies from children.
CONCLUSIONS: The responsibility for improving the rate of adequate biopsies lies
with individual centres. Reporting pathologists might help by making even more
positive attempts to influence operators within their own centres.
PMID- 10690180
TI - Post-test probability that men in the community with raised plasma ferritin
concentrations are hazardous drinkers.
AB - BACKGROUND: Raised plasma ferritin concentrations occur unexpectedly during iron
studies done by primary care physicians. Plasma ferritin concentration has been
positively associated with alcohol use among men. AIM: To determine the post-test
probability that men in the community with raised plasma ferritin concentrations
are hazardous drinkers. METHODS: The subjects were 152 men, randomly selected
from a city's electoral roll. Nineteen (12.5 (2.7)%, mean (SEM)) admitted to
drinking hazardously. The pretest probability of a man being a hazardous drinker
was 0.125. This was converted to pretest odds of 0.14. The likelihood ratio (the
ratio of the probability of obtaining a raised plasma ferritin concentration in a
hazardous drinker (sensitivity) to the probability of obtaining a raised plasma
ferritin concentration in a non-hazardous drinker (1-specificity)) was calculated
for different plasma ferritin cut off points. RESULTS: A plasma ferritin level of
> 652 micrograms/l gave the largest likelihood ratio, 4.16. Post-test odds were
obtained by multiplying the pretest odds (0.14) by the likelihood ratio (4.16). A
plasma ferritin level of > 652 micrograms/l had a post-test odds for a man being
a hazardous drinker of 0.58. This was converted to a post-test probability of
0.37. CONCLUSIONS: Inquiries could usefully be made into the alcohol consumption
of men with a plasma ferritin concentration > 652 micrograms/l, as approximately
one in three would admit to drinking hazardously.
PMID- 10690181
TI - Information before coronial necropsy: how much should be available?
AB - AIM: To assess the amount and quality of information supplied before undertaking
a coroner's necropsy, based on the supposition that insufficient information may
adversely affect the quality of the necropsy. METHODS: For a one year period (947
cases), sudden death reports from the coronial jurisdiction of South Yorkshire
(West) were audited to assess the quality of information supplied. Seven specific
items of information were sought: age, sex, occupation, date of death, location
of the body, position of the body, date of last seeing a general practitioner,
and relevant medical history. The results from necropsy and non-necropsy cases
were compared. RESULTS: Only 22.1% of reports contained all seven items of
information. There was no difference between the amount of information supplied
in necropsy and non-necropsy cases except about when the general practitioner
last saw the deceased. An occupational history was not available in 40.4% of all
deaths. CONCLUSIONS: The quality of information supplied to the pathologist
before necropsy may be suboptimal and could affect the thoroughness of the
necropsy itself.
PMID- 10690182
TI - Molecular epidemiology of ocular isolates of adenovirus 8 obtained over nine
years.
AB - Twenty nine strains of adenovirus 8 have been isolated over nine years in
Strasbourg, France, 22 of which were from one private ophthalmologist. To assess
a possible relation between these strains, the DNA of adenovirus was analysed by
restriction fragment length polymorphism using eight different enzymes. Among
these, three proved discriminant (Xba I, Bgl II, Eco RI) and made it possible to
define 13 genotypes differing from each other by one to three DNA bands. Seven
genotypes were unique isolates, while three, representing 16 strains, were
isolated over five to eight years. All the genotypes but one were closely
related, with 87% homology. All 13 differed from an adenovirus 8 strain from Lyon
(homology 68-76%). This study confirmed the stability of adenovirus 8 in a given
population.
PMID- 10690183
TI - CD44s as a surrogate marker for distinguishing intraductal papilloma from
papillary carcinoma of the breast.
AB - BACKGROUND: It has been shown that CD44 variants are differentially expressed in
normal and neoplastic breast tissues. The diagnostic value of these markers in
distinguishing benign from malignant breast lesions has not been well examined.
AIMS: To evaluate the diagnostic value of CD44s in distinguishing between
intraductal papillomas and papillary carcinomas of the breast, which may be
difficult morphologically. METHODS: Expression of CD44s detected by
immunohistochemistry was studied in a series of intraductal papillomas (11) and
papillary carcinomas (10). The normal breast tissues surrounding the lesions of
these cases served as a control. The number of CD44s positive epithelial cells
was scored and categorised as < 10%, 10-70%, or > 70%. RESULTS: Normal breast
epithelial cells and all intraductal papillomas (11 of 11) expressed CD44s in a
high proportion of cells (> 70%). In contrast, the majority of papillary
carcinoma cases (eight of 10) expressed this marker in < 10% of the cells. In the
remaining two papillary carcinoma cases, positivity was seen in more than 10% but
still less than 70% of the cells. CONCLUSIONS: CD44s detection by
immunohistochemistry is useful in distinguishing intraductal papillomas from
papillary carcinomas of the breast.
PMID- 10690184
TI - Granulocytic sarcoma of the rectum: a rare complication of myelodysplasia.
AB - A 67 year old man with myelodysplasia was admitted as an emergency with a six
week history of rectal bleeding and diarrhoea. Barium enema showed an irregular
polypoid filling defect in the lateral wall of the proximal rectum near the
rectosigmoid junction. Histology showed this to be a granulocytic sarcoma
(extramedullary granulocytic leukaemia; chloroma) infiltrating the bowel. A low
index of suspicion of this lesion results in an incorrect diagnosis in many such
cases. A chloroacetate esterase immunoperoxidase stain will confirm the
granulocytic nature of the tumour cells.
PMID- 10690185
TI - Reporting basal cell carcinoma: a survey of the attitudes of histopathologists.
AB - AIMS: To investigate the histopathological reporting of basal cell carcinoma.
METHODS: Methods of classification and attitudes to excision margins were
ascertained from histopathologists in 130 centres; 82 replies were obtained (63%
response rate). RESULTS: 24% of those replying did not use any classification
system for basal cell carcinoma. The remainder (76%) used a wide variety of
different classification systems. A small number (9%) of those questioned felt
reporting on completeness of excision was not important. The majority of
histopathologists considered the excision margin was worth reporting but there
were differences in methods of processing and reporting biopsies. CONCLUSIONS:
There is considerable variation in histopathological reporting of basal cell
carcinoma. There is a need for uniformity of histopathological reporting to allow
both improved management decisions and comparative audit of this extremely common
skin cancer.
PMID- 10690186
TI - Effects of sulphapyridine on sperm transport through the rat epididymis and
contractility of the epididymal duct.
AB - This study was undertaken to investigate the effects of sulphapyridine on the
transport of spermatozoa through different regions of the epididymis and on the
contractility of the epididymal duct in the rat. Sperm transport was investigated
by labelling testicular spermatozoa with [3H]thymidine and measuring intraluminal
pressures of the epididymis by micropuncture, using a servo-nulling pressure
transducer system. In control rats, the transit times of epididymal spermatozoa
from the initial segment to the caput, from the caput to the proximal cauda, and
from the proximal cauda to the distal cauda were 2, 6 and 3 days, respectively,
giving a total transit time of 11 days. The total transit time was shortened to 8
days after treatment with sulphapyridine at a dosage of 450 mg kg-1 for 38-52
days. The rate of sperm transport was most affected in the caput epididymidis.
Measurements of intraluminal pressures showed that sulphapyridine had no effect
on spontaneous contractions in any regions of the epididymis. However, the
frequency of contraction of the corpus and cauda epididymides in response to
administration of 10 micrograms noradrenaline kg-1 in the sulphapyridine-treated
rats was significantly higher (P < 0.05) than it was in the controls.
Methacholine, at a dose of 20 micrograms kg-1, produced a smaller increase in
basal pressure in the caput epididymidis of sulphapyridine-treated rats (P <
0.05) compared with controls. The results led to the conclusion that
sulphapyridine increases the rate of sperm transport from the caput through the
cauda epididymidis, in part, by changes in the responsiveness of the epididymis
to the autonomic nervous system.
PMID- 10690187
TI - Effect of oxytocin on concentration of PGF2 alpha in the uterine lumen and
subsequent endometrial responsiveness to oxytocin in pigs.
AB - The aim of this study was to determine the effect of oxytocin on PGF2 alpha
secretion into the uterine lumen of pigs and subsequent endometrial
responsiveness to oxytocin in vitro. Cyclic, pregnant and oestradiol-induced
pseudopregnant gilts were injected i.v. with vehicle or 20 iu oxytocin 10 min
before hysterectomy on day 16 after oestrus. Concentrations of PGF2 alpha and
13,14-dihydro-15-keto PGF2 alpha (PGFM) were significantly increased in uterine
flushings collected at hysterectomy (P < 0.05) in pregnant oxytocin-injected
gilts. Concentrations of PGF2 alpha and PGFM were greater (P < 0.001) in pregnant
than in pseudopregnant and cyclic gilts, and greater (P < 0.01) in pseudopregnant
than in cyclic gilts. The ratio of PGFM:PGF2 alpha tended to be greater in cyclic
(P < 0.06) and pseudopregnant gilts (P < 0.1) than in pregnant gilts. At 85 +/- 5
min after oxytocin injection, endometrium from each gilt was incubated for 3 h
for determination of phosphoinositide hydrolysis and PGF2 alpha secretion in
response to treatment with 0 or 100 nmol oxytocin l-1. Endometrial
phosphoinositide hydrolysis in response to 100 nmol oxytocin l-1 in vitro was
greater (P < 0.05) in cyclic oxytocin-injected gilts than in cyclic vehicle
injected gilts. Treatment with oxytocin in vitro did not stimulate
phosphoinositide hydrolysis significantly in vehicle- or oxytocin-injected
pregnant gilts or pseudopregnant gilts. Endometrial PGF2 alpha secretion
increased after treatment with 100 nmol oxytocin l-1 in vitro in cyclic vehicle
injected (P < 0.01), cyclic oxytocin-injected (P < 0.01), pregnant vehicle
injected (P = 0.06), pseudopregnant vehicle-injected (P < 0.05) and
pseudopregnant oxytocin-injected (P < 0.05) gilts, but not in pregnant oxytocin
injected gilts. The increase in PGF2 alpha in pseudopregnant oxytocin-injected
gilts was less (P < 0.05) than that in cyclic oxytocin-injected gilts. These
results indicate that oxytocin increases the concentration of PGF2 alpha and PGFM
in the uterine lumen during pregnancy and may upregulate endometrial
responsiveness to oxytocin during late dioestrus in pigs, but does not have the
latter effect during early pregnancy or oestradiol-induced pseudopregnancy.
PMID- 10690188
TI - Effect of transport on pulsatile LH release in ovariectomized ewes with or
without prior steroid exposure at different times of year.
AB - The initial aim of the present study was to test whether the stress of transport
suppresses LH pulsatile secretion in ewes. In a pilot experiment in the late
breeding season, transport resulted in an unexpected response in three out of
five transported, ovariectomized ewes pretreated with oestradiol and
progesterone. Before transport, seasonal suppression of LH pulses had occurred
earlier than anticipated, but LH pulsatility suddenly restarted for the period of
transport. This finding was reminiscent of unexplained results obtained in
ovariectomized ewes infused centrally with high doses of corticotrophin-releasing
hormone after pretreatment with low doses of oestradiol with or without
progesterone. Hence, an additional aim of the present study was to examine
whether these latter results with corticotrophin-releasing hormone could be
reproduced by increasing endogenous corticotrophin-releasing hormone secretion by
transport. Subsequent experiments used groups of at least eight ovariectomized
ewes at different times of the year with or without prior exposure to steroids to
assess whether these unexpected observations were associated with season or the
prevailing endocrine milieu. In the mid-breeding season, transport for 4 h in the
absence of steroid pretreatment for 8 months reduced LH pulse frequency from 7.5
+/- 0.3 to 6.3 +/- 0.4 pulses per 4 h (P < 0.05) and LH pulse amplitude from 2.6
+/- 0.5 to 1.8 +/- 0.3 ng ml-1 (P < 0.05). Similarly, in the mid-breeding season,
34 h after the cessation of pretreatment with oestradiol and progesterone,
transport suppressed LH pulse frequency from 6.1 +/- 0.4 to 5.5 +/- 0.3 pulses
per 4 h (P < 0.05) with a tendency of effect on amplitude (6.2 +/- 2.7 to 2.61 +/
0.6 ng ml-1; P = 0.07; note the large variance in the pretransport data). During
mid-anoestrus, evidence of a suppressive effect of transport was only observed on
LH pulse amplitude (4.7 +/- 0.6 versus 3.0 +/- 0.5 pulses per 4 h; P < 0.05) in
ovariectomized ewes that had not been exposed to ovarian steroids for 4 months.
Repetition of the pilot experiment with 12 ewes during the transition into
anoestrus resulted in one ewe with LH pulses seasonally suppressed but increased
by transport; 11 ewes had a distinct pulsatile LH pattern which was decreased by
transport in six ewes. In anoestrus, there was no effect of transport on LH pulse
frequency or amplitude in intact ewes, or those ovariectomized 2-3 weeks
previously, with or without prior oestradiol and progesterone treatment. However,
basal concentrations of cortisol were greater in anoestrus than in the breeding
season, and the increment in cortisol during transport was similar in anoestrus
and the breeding season but greater during the transition into anoestrus (P <
0.05). Progesterone concentrations increased from 0.31 +/- 0.02 ng ml-1 before
transport to 0.48 +/- 0.05 ng ml-1 during the second hour of transport (P <
0.05). In conclusion, transport reduced LH pulse frequency and amplitude in
ovariectomized ewes that had not been exposed to exogenous steroids for at least
4 months. In most animals, the previously observed increase in LH pulsatility
induced by exogenous CRH was not reproduced by increasing endogenous CRH
secretion by transport. However, in four ewes, transport did increase LH
pulsatility, but only during the transition into anoestrus in ewes with
seasonally suppressed LH profiles after withdrawal of steroid pretreatment.
PMID- 10690189
TI - Reproductive function in male rats with chronic nephrosis.
AB - Endocrine dysfunction has been associated with renal diseases. The present study
was conducted to explore reproductive function in male rats with chronic
nephrosis. Experimental chronic nephrosis was induced by the administration of
7.5, 5.0 and 5.0 mg per 100 g body weight of puromycin aminonucleoside on days 0,
21 and 35, respectively. Reproductive function was evaluated on the basis of
hormonal concentrations, mass of accessory sex organs and fertility during an 84
day period. Circulating LH, FSH, testosterone and oestradiol concentrations were
measured by specific radioimmunoassays, while fertility was estimated by the rate
of pregnancy induction. Samples were collected on days 7, 14, 28, 56 and 84. The
results showed an important endocrine dysfunction characterized by low
concentrations of LH and FSH during the first month, after which concentrations
were similar to control values or even increased on days 56 and 84. Testosterone
and oestradiol decreased significantly at all time points evaluated. The mass of
the testes did not alter. However, the mass of the prostate and seminal vesicle
decreased only during the first 2 weeks, and became essentially normal
thereafter. The reproductive capacity of nephrotic males was eliminated on day 7,
whereas on day 14, 16% of the group was able to mate successfully and
subsequently most animals recovered their normal reproductive function. This
study demonstrates for the first time that rats with experimental chronic
nephrosis develop an important endocrine dysfunction, characterized mainly by
persistent reduction in testosterone concentrations, which impairs reproductive
capacity only transiently.
PMID- 10690190
TI - Characterization of endoglin on mouse uterine stromal cells.
AB - During the oestrous cycle and early pregnancy, the uterus undergoes a variety of
morphological and physiological modifications involving uterine cell
proliferation and differentiation as well as extensive tissue remodelling.
Transforming growth factor beta (TGF-beta) has powerful effects on these events
and thus is thought to have a critical role in uterine physiology. Endoglin is a
transmembrane glycoprotein that binds TGF-beta 1 and -beta 3 and interacts with
TGF-beta signalling receptors to modulate many effects of this growth factor in
different types of cell. Studies in mice revealed the highest concentrations of
endoglin in the reproductive tract, notably on stromal cells of cyclic and
pregnant uteri. The objective of the present study was to investigate the role of
endoglin expressed on uterine stromal cells in binding TGF-beta and in the
cellular responses induced by this growth factor. Highly purified populations of
uterine stromal cells were isolated by cell affinity to the monoclonal antibody
MJ7/18, which is specific to mouse endoglin. Affinity labelling of these cells
with 125I-labelled TGF-beta followed by immunoprecipitation with endoglin
specific polyclonal 1256:4b antiserum indicated that endoglin expressed at the
surface of uterine stromal cells binds TGF-beta 1 and interacts with TGF-beta
signalling receptors. Treatment of uterine stromal cells with different
concentrations of TGF-beta 1 induced a biphasic proliferative response and
addition of MJ7/18 as well as neutralizing TGF-beta antibodies showed endoglin to
be a modulator of TGF-beta-induced stromal cell proliferation. Given the
importance of TGF-beta in the regulation of uterine physiology, these results
indicate a role for endoglin during uterine tissue remodelling and
decidualization.
PMID- 10690191
TI - Comparison of the steroidogenic capacity of bovine follicular and luteal cells,
and corpora lutea originating from dominant follicles of the first or second
follicular wave.
AB - This study, compared the endocrine function of dominant follicles of the first
and second follicular waves (DF1 and DF2, respectively) and the corpora lutea
that were subsequently formed. In the experiments conducted in vitro, ovaries
were collected from dairy cows on day 6.1 +/- 0.2 or day 14.8 +/- 0.2 of the
oestrous cycle to obtain steroidogenically active DF1 (n = 8) and DF2 (n = 7).
Granulosa and thecal cells were isolated, dispersed and incubated for 16 h with
testosterone (granulosa cells) or forskolin or bLH (thecal cells). Both types of
cell were subsequently cultured for 9 days with forskolin and insulin. The
viability of the granulosa cells was similar in DF1 and DF2, but the
concentration of oestradiol in the follicular fluid was higher in DF1 than in
DF2. Production of oestradiol and progesterone by granulosa cells was similar in
DF1 and DF2, but androstenedione and progesterone production by thecal cells were
3.5-6.5-fold higher in DF1 than in DF2. During the 9 days of luteinization,
progesterone production was similar in DF1- and DF2-derived granulosa cells, but
was two- to three-fold higher in DF1- than in DF2-derived thecal cells.
Experiments were also conducted in vivo. In Expt 1 in vivo, lactating cows that
were assigned to ovulate DF1 or DF2 (n = 9 and 13 in replicate 1 and 2,
respectively) were injected with PGF2 alpha on days 6 and 7 or on days 14 and 15
of the oestrous cycle, respectively. A wave by replicate interaction was detected
for plasma progesterone concentration in the subsequent cycle: in the first
replicate, progesterone production was approximately 40% higher in cows that
ovulated DF1; in the second replicate, progesterone production was similar in
cows that ovulated DF1 or DF2. In Expt 2, pooled plasma progesterone in the mid
luteal phase (days 12-15) after insemination of pregnant and non-pregnant cows
was approximately 30% higher in cows that had ovulated DF1 (n = 32) than in cows
that had ovulated DF2 (n = 22). This study showed DF1 had a higher steroidogenic
capacity compared with DF2, which may be related to the hormonal environment in
which the follicles developed.
PMID- 10690192
TI - Effect of FSH infusion on follicle development in GnRH agonist-treated gilts.
AB - The aim was to investigate the effect of infusion of purified FSH alone on
follicle development in hypogonadotrophic GnRH agonist-treated gilts. Large-White
hybrid gilts (n = 12) were treated during the mid-luteal phase and again after 28
days (day 0) with a potent slow releasing GnRH agonist. On day 3, seven gilts
were infused for 168 h with 1.5 S1 units oFSH h-1 (equivalent to 1.5 units of
bioactivity of NIH-FSH-S1 standard) and blood samples were collected. Ovaries
were then recovered and all follicles > or = 1 mm in diameter were dissected and
incubated for 2 h in 1 ml Eagle's minimum essential medium. The ovaries were
recovered from the remaining five GnRH agonist-treated gilts on day 10 and also
from five cyclic gilts during the late follicular phase (controls). Plasma FSH
concentrations in GnRH agonist-treated gilts were lower (P < 0.01) than in
follicular phase controls, increased (P < 0.001) after 1 h of FSH infusion and
reached a plateau similar (P > 0.1) to that of controls after 8 h. Basal LH
concentrations were similar (P > 0.1) between GnRH agonist-treated and control
gilts and remained unchanged (P > 0.1) throughout the infusion period. GnRH
agonist treatment reduced (P < 0.01) basal oestradiol concentrations compared
with control gilts. Infusion with FSH alone increased (P < 0.001) plasma
oestradiol concentrations after 96 h compared with those before infusion; when
the animals were killed oestradiol concentrations were higher (P < 0.01) in GnRH
agonist-treated gilts infused with FSH than in controls. This was also apparent
by vulval swelling and behavioural oestrus. There were more follicles > or 1 mm
in diameter in the GnRH agonist-treated groups than in the controls (184, 153 and
86 per animal; P < 0.01). Infusion with FSH increased the maximum follicle
diameter (GnRH agonist: < 4 mm; FSH infused: < 12 mm; controls: < 10 mm) and
tended to increase (P < 0.07) the mean number of follicles > or = 6 mm diameter
per animal (FSH infused: 53; controls: 21). Total oestradiol production in vitro
by follicles > or = 1 mm was higher (P < 0.01) in GnRH agonist-treated gilts
infused with FSH and in follicular phase controls than in animals treated with
GnRH agonist alone. However, oestradiol and testosterone secretion in vitro per
follicle > or = 6 mm in diameter was lower (P < 0.05) in FSH-infused animals than
in controls. In summary, although infusion of FSH alone stimulated the growth of
multiple follicles of preovulatory size in GnRH agonist-treated gilts,
steroidogenic output by individual follicles was impaired.
PMID- 10690193
TI - Direct effects of ovine follicular fluid on ovarian steroid secretion and
expression of markers of cellular differentiation in sheep.
AB - The objective of this study was to assess the effect of ovine follicular fluid
(FF) treatment (with or without FSH replacement) during the late follicular phase
on plasma concentrations of gonadotrophins and the development of the ovulatory
follicle. Ovarian steroid secretion and expression of mRNA encoding inhibin alpha
and beta A, beta B subunits, P450 aromatase and P450 17 alpha-hydroxylase were
used as endpoints. After induction of luteolysis by injection of 100 micrograms
cloprostenol on days 10-12, Scottish Blackface ewes were allocated to one of
three groups: (1) control (n = 7): no further treatment; (2) FF (n = 9):
subcutaneous injections of 3 ml steroid-free ovine follicular fluid at 9 h
intervals, 18 and 27 h after cloprostenol injection; (3) FF + FSH (n = 8):
injections of follicular fluid as above plus subcutaneous injections of 0.36 iu
ovine FSH at 6 h intervals, 18, 24, and 30 h after cloprostenol injection.
Jugular venous blood samples were obtained via indwelling cannulae at 6 h
intervals from 0 to 36 h after cloprostenol injection, and at 10 min intervals
from 12 to 18 h (control phase) and from 30 to 36 h after cloprostenol injection
(treatment phase). At laparotomy, 36 h after cloprostenol injection, ovarian
venous blood was collected and ovaries were removed and processed for in situ
hybridization. Plasma concentrations of FSH, luteinizing hormone (LH) and
oestradiol were determined by radioimmunoassay. Follicular fluid treatment
resulted in a decrease (P < 0.001) in FSH concentrations associated with an acute
decrease in ovarian steroid secretion (P < 0.01) and a specific depression in
P450 aromatase, (P < 0.001), inhibin-activin beta B subunit (P < 0.05) and thecal
LH receptor (P < 0.001) expression. Follicular fluid treatment had no effect on
inhibin-activin alpha and beta A, subunit or P450 17 alpha-hydroxylase
expression. FSH co-treatment with follicular fluid restored circulating FSH
concentrations to normal values and reversed some of the effects of follicular
fluid (androstenedione, testosterone and progesterone secretion, and inhibin beta
B and thecal LH receptor expression) but not oestradiol secretion or P450
aromatase expression. It was concluded that the actions of follicular fluid are
mediated via both central effects on pituitary FSH secretion and by direct
ovarian effects on granulosa cell aromatase activity. The results indicate that
follicular fluid contains a factor that inhibits aromatase activity of granulosa
cells directly and may play a role in the selection of the dominant follicle.
PMID- 10690194
TI - Sources of variation in the morphological characteristics of sperm subpopulations
assessed objectively by a novel automated sperm morphology analysis system.
AB - There is evidence that the mammalian ejaculate contains distinct subpopulations
of spermatozoa and that the variability among these subpopulations may have
adaptive and functional significance. This study investigated the precision,
reproducibility and operating characteristics of a novel automated sperm
morphology analysis system, the Hobson Morphology package, establishing protocols
to investigate boar sperm characteristics. Five ejaculates were collected from
each of three boars from different genetic lines: Landrace-Meishan introgression,
Sireline Large White and Damline Large White. Five semen smears per ejaculate
were stained with haematoxylin and eosin. Two hundred spermatozoa per slide were
analysed. No significant differences among slides within an ejaculate were
detected for sperm tail length (P = 0.770), head width (P = 0.736) and head
length (P = 0.615), indicating that both staining and morphology analysis were
precise and reproducible. Among the boars, variability in tail length was
detected (P = 0.001), but head width (P = 0.114) and length (P = 0.069) did not
differ significantly. Multivariate pattern analysis (PATN computer package)
highlighted three sub-populations of spermatozoa objectively on the basis of tail
length (10.0-22.0 microns, 22.1-73.0 microns and 73.1-130.0 microns). The
Landrace-Meishan introgression boar possessed more spermatozoa (P < 0.0001) with
tails 73.1-130 microns long. Subsequent analysis of morphology parameters in a
pure-bred Meishan boar showed similar measurements for tail length (mean +/- SD;
66.36 +/- 24.70 microns) to the Landrace-Meishan introgression boar (mean +/- SD;
67.09 +/- 21.80 microns). Sperm subpopulations originate during spermatogenesis,
when heterogeneous genotypic effects determine the structural features of
spermatozoa. The findings of this study confirm that tail length differs between
boars and that subpopulations of spermatozoa can be detected within a single
ejaculate.
PMID- 10690195
TI - Immune cell populations in the equine corpus luteum throughout the oestrous cycle
and early pregnancy: an immunohistochemical and flow cytometric study.
AB - Recent evidence indicates that the cells of the immune system and their large
network of secretory products, or cytokines, play an active role in the ovary
throughout the oestrous cycle. In the present study, immune cell populations (T
and B lymphocytes, macrophages, granulocytes and eosinophils) and expression of
major histocompatibility complex (MHC) class II were investigated in corpora
lutea from mares in early (days 2-4), mid- (days 7-10) and late (days 12-14)
dioestrus, the post-luteolytic phase (days 16-17) and early pregnancy. The number
of T lymphocytes within the corpus luteum increased in the late luteal phase.
CD4+ cells did not increase until day 16, whereas the number of CD8+ cells
increased before functional luteolysis; an apparently selective luteal
infiltration of CD8+ cells was observed. MHC class II expression by non
steroidogenic cells was increased in samples from days 16-17, as was the number
of infiltrating macrophages. Flow cytometry revealed very low expression of MHC
class II by large luteal cells at all stages of the oestrous cycle. In early
pregnancy, the number of CD4+ and CD8+ cells and macrophages decreased, as did
MHC class II expression, compared with mid-dioestrous samples. B cells were
present in very small numbers in all samples examined. Eosinophils were similarly
sparsely distributed and numbers decreased further in pregnancy. After exogenous
PGF2 alpha administration, populations of CD4+ cells and non-specific esterase
staining cells were significantly smaller than after natural luteolysis, whereas
eosinophil numbers were increased compared with samples from days 16-17. However,
the number of CD8+ and CD5+ cells and MHC class II expression were not
significantly different from those observed after natural luteolysis. These
findings indicate that populations of immune cells in the equine corpus luteum
vary during its lifespan. The selective increase in CD8+ cells before functional
luteolysis indicates that they have a physiological role in the regression of the
corpus luteum.
PMID- 10690196
TI - Differentiation of donor primordial germ cells into functional gametes in the
gonads of mixed-sex germline chimaeric chickens produced by transfer of
primordial germ cells isolated from embryonic blood.
AB - This study was carried out to elucidate whether primordial germ cells, obtained
from embryonic blood and transferred into partially sterilized male and female
recipient embryos, could differentiate into functional gametes and give rise to
viable offspring. Manipulated embryos were cultured until hatching and the chicks
were raised until maturity, when they were mated. When the sex of the donor
primordial germ cells and the recipient embryo was the same, 15 out of 22 male
chimaeric chickens (68.2%) and 10 out of 16 female chimaeric chickens (62.5%)
produced donor-derived offspring. When the sex of the donor primordial germ cells
and the recipient embryo was different, 4 out of 18 male chimaeric chickens
(22.2%) and 2 out of 18 female chimaeric chickens (11.1%) produced donor-derived
offspring. The rates of donor-derived offspring from the chimaeric chickens were
0.6-40.0% in male donor and male recipient and 0.4-34.9% in female donor and
female recipient. However, the rates of donor-derived offspring from the
chimaeric chickens were 0.4-0.9% in male donor and female recipient and 0.1-0.3%
in female donor and male recipient. The presence of W chromosome-specific
repeating sequences was detected in the sperm samples of male chimaeric chickens
produced by transfer of female primordial germ cells. These results indicate that
primordial germ cells isolated from embryonic blood can differentiate into
functional gametes giving rise to viable offspring in the gonads of opposite-sex
recipient embryos and chickens, although the efficiency was very low.
PMID- 10690197
TI - Effects of oxytocin and vasopressin on sperm transport from the cauda epididymis
in sheep.
AB - This study was performed to determine whether oxytocin or vasopressin affect the
transport of spermatozoa from the epididymis of rams in vivo. Under general
anaesthesia, cannulae were inserted into each ductus deferens and passed into the
cauda epididymis of 24 Oxford Down cross rams and the luminal fluid was collected
at 10 min intervals for 2-3 h. Animals were divided into seven groups and
received either (i) 2 ml 0.9% saline, (ii) 10 micrograms oxytocin, (iii) 100
micrograms oxytocin, (iv) 100 micrograms oxytocin antagonist, (v) 300 micrograms
oxytocin antagonist followed by 100 micrograms oxytocin, (vi) 100 micrograms
vasopressin, or (vii) 100 micrograms vasopressin followed by 100 micrograms
oxytocin, all by i.v. injection. The mass of fluid and number of spermatozoa in
each 10 min sample was measured and the motility of the spermatozoa was assessed.
Treatment with saline did not affect the mass or the number of spermatozoa in the
fluid collected. Oxytocin at 10 micrograms significantly increased both the
output of fluid and the number of spermatozoa by twofold. Oxytocin at 100
micrograms produced a greater increase in both fluid output and the number of
spermatozoa within 10 min of administration of the peptide. Treatment with
oxytocin antagonist had no immediate effect, but subsequently caused a
significant reduction in both fluid output and the number of spermatozoa.
Pretreatment with oxytocin antagonist inhibited the stimulatory effect of
oxytocin. Vasopressin did not increase the number or concentration of spermatozoa
in the fluid and appeared to decrease fluid output. No significant changes in the
morphology or motility of the spermatozoa collected was observed in any of the
samples. These data demonstrate that oxytocin has specific actions on the
epididymis to increase sperm transport. They indicate that local oxytocin may be
involved in regulating basal contractility of the cauda epididymidis and that
augmentation by the peptide in the peripheral circulation, as occurs around the
time of ejaculation, may promote a significant increase in the transport of
spermatozoa into the vas deferens and ejaculate.
PMID- 10690198
TI - Variability in the size of the nucleus in spermatozoa from Houbara bustards,
Chlamydotis undulata undulata.
AB - Semen collected from 3-year-old male Houbara bustards contained large proportions
(6-40%) of spermatozoa with large nuclei. In these spermatozoa, the length of the
nucleus was up to twice the mean length of the nucleus in normal spermatozoa. The
lengths of the acrosome, midpiece and flagella were all normally distributed, but
the length of the nucleus formed a bimodal distribution. The proportion of
spermatozoa with large nuclei varied among males, but not among different semen
samples collected from the same male throughout the breeding season. The
proportion of motile spermatozoa with large nuclei was half that of normal
spermatozoa, but their velocity was significantly greater. After insemination
into females, spermatozoa with large nuclei were observed in the outer
perivitelline layer of eggs laid, indicating that they were stored and
transported within the oviduct and reached the egg at about the time of
fertilization. Furthermore, there was no difference in the ability to produce
viable progeny in females that were mated with males producing greater
proportions of spermatozoa with large nuclei compared with those producing
'normal' spermatozoa. Thus, the abnormal spermatozoa did not appear to impede
fertility. There were no signs of triploidy in the males that produced
spermatozoa with large nuclei, or in their progeny, as demonstrated by the size
of erythrocytes. Therefore, it appears that the spermatozoa with large nuclei
were the result of aberrant spermatogenesis.
PMID- 10690199
TI - Correlation of increased concentration of ovine endometrial cyclooxygenase 2 with
the increase in PGE2 and PGD2 in the late luteal phase.
AB - Ovine endometrium showed transient expression of high concentrations of the
inducible isoform of cyclooxygenase, cyclooxygenase 2 (COX-2), whereas the
constitutive isoform, cyclooxygenase 1 (COX-1), was expressed at much lower
concentrations and did not change. In this study, the pattern of prostaglandin
synthesis in endometrial luminal cells was investigated in relation to their COX
2 content. Endometrial cells from cyclic or pregnant ewes at days 9, 12, 14 and
16 were isolated and analysed for the presence of COX-1 and COX-2 proteins using
western blot analysis. Freshly isolated cells were incubated with 0.5 microCi
[3H]arachidonic acid ml-1. Radioactive cyclooxygenase metabolites were analysed
by reverse-phase HPLC. Luminal cells produced mainly PGF2 alpha, PGE2, PGD2 and
13,14-dihydro-15-keto PGF2 alpha and to a lesser extent 6-keto PGF1 alpha,
thromboxane B2 and 13,14-dihydro-15-keto PGE2. The production of PGE2 and PGD2
was proportional to the cellular concentration of COX-2. PGE2 and PGD2 release
was low on day 9 when COX-2 was not expressed, whereas high concentrations of
PGE2 and PGD2 were synthesized on days 12-14 when COX-2 was highly expressed,
reaching 100 ng microgram-1 cellular protein. In contrast, the basal production
of PGF2 alpha did not appear to be related to COX-2 concentration and was
greatest on day 16. Moreover, the release of PGF2 alpha was maintained at steady
state values between days 9 and 14 by the production of 13,14-dihydro-15-keto
PGF2 alpha. Although PGF2 alpha output was lower at day 16 of pregnancy compared
with the oestrous cycle, no difference was observed in the pattern of
prostaglandin synthesis between pregnant and non-pregnant ewes.
PMID- 10690200
TI - Sequence of apoptosis and inflammatory necrosis within the formative ovulatory
site of sheep follicles.
AB - The aim of this study was to define the temporal and spatial patterns of
apoptosis, necrosis and inflammation within preovulatory ovine follicles. A
gonadotrophin surge was induced in pro-oestrous ewes by GnRH, and isolated
follicles were hemisected into apical and basal segments at 0, 10, 18 and 22 h
(the time of ovulatory stigma development) after GnRH. Ovarian surface epithelial
and granulosa cells were isolated and assessed by fluorescence microscopy for
membrane phosphatidylserine translocation-annexin V (early-stage apoptosis),
oligonucleosomal DNA nick endlabelling (advanced apoptosis), and nuclear
propidium iodide incorporation (necrotic membrane disruption). Thecal shells were
analysed for interstitial blood cells. Preovulatory follicles were also
hemisected and subjected to electrophoretic DNA degradation analysis. Annexin V
binding and in situ DNA fragmentation among ovarian surface epithelial and
granulosa cells along the follicular apex were high 18 and 22 h after GnRH.
Propidium iodide staining of apical ovarian surface and granulosa cells was
apparent at 22 h. There was a coincident increase within the apical theca as the
time of ovulation approached in extravasated leucocytes (18 and 22 h) and
erythrocytes (22 h). Apoptotic DNA laddering and necrotic DNA smears within the
follicular apex were evident on agarose gels at 18 and 22 h, respectively. In
contrast, ovarian surface epithelium not associated with the ovulation site and
the basal follicular wall were largely unafflicted. It is suggested that both
modalities of cellular death, apoptosis and necrosis (with acute inflammation and
vascular injury), contribute progressively to follicular stigma formation and
ovarian rupture.
PMID- 10690201
TI - Effect of exogenous melatonin on neuroendocrine-reproductive function of middle
aged female rats.
AB - The possible role of melatonin in the regulation of the reproductive system of
female rats during ageing was investigated in middle-aged female rats showing
irregular duration of the oestrous cycle (n = 30). Blood samples were obtained by
jugular venepuncture during the oestrous cycle in control rats. After this
experiment was completed, the female rats were treated with melatonin for 2
months and blood samples were obtained at different stages of the oestrous cycle.
Plasma LH, FSH and prolactin concentrations were significantly increased in the
afternoon of the day of pro-oestrus after melatonin treatment compared with
control rats. Moreover, FSH concentrations too were significantly increased on
the morning of pro-oestrus and oestrus in melatonin treated rats compared with
control rats. Similarly, oestradiol concentrations were significantly higher on
the morning of pro-oestrus in melatonin treated rats compared with controls.
Another group of rats showing irregular duration of the oestrous cycle was used
to study the possible effect of melatonin treatment on the timing of pro-oestrous
surges of LH and FSH. The results showed that LH and FSH peak values occurred at
5 h after melatonin treatment. Pituitary responsiveness to LHRH in a 90 min test
was also studied in middle-aged rats showing irregular duration of the oestrous
cycle that had been injected for 1 month with either melatonin or saline.
Prolactin response was unaffected by exogenous melatonin, but a stimulatory
effect of melatonin on LH and FSH pituitary responsiveness to LHRH was observed.
The results indicate an improved function of the neuroendocrine-reproductive axis
in middle-aged rats after melatonin treatment.
PMID- 10690202
TI - Single-section counting error when distinguishing between primordial and early
primary follicles in sections of rat ovary of different thickness.
AB - The number of primordial follicles within an ovary is frequently determined by
counting 5, 7 or 10 microns thick sections and multiplying by the fraction of
sections counted and a correction factor to adjust for duplicate counts. The
objectives of the present study were: (i) to evaluate the accuracy of the
correction factor developed by Abercrombie (1946); (ii) to evaluate the accuracy
of the classification of primordial follicles from single tissue sections; and
(iii) to determine the incorporation rate of 5-bromo-2-deoxyuridine into
primordial follicles. In Expt 1, rat ovaries were sectioned at a thickness of 5,
7 or 10 microns. Primordial follicles were counted and classified across ten
adjacent ovarian sections. The percentage of primordial follicles from single
sections that were counted twice was 10, 9 and 2% in 5, 7 and 10 microns
sections, respectively. This was lower than predicted by Abercrombie's method.
The major error in counting from single sections was classification of early
primary follicles as primordial follicles (55, 33 and 3% in 5, 7 and 10 microns
sections, respectively). In Expt 2, a mean of 12 +/- 7% of primordial follicles
incorporated 5-bromo-2-deoxyuridine after infusion for 7 days (four of seven rats
had no labelled primordial follicles). IN CONCLUSION: (i) Abercrombie's
correction factor should not be used for adjusting counts of follicles; (ii)
evaluation of primordial follicles from single sections gives inaccurate counts
and incorrect classification is of greater importance than duplicate counting,
particularly in thinner sections; (iii) for evaluation of the number of
follicles, 10 microns is the optimal thickness; and (iv) primordial follicles
incorporated 5-bromo-2-deoxyuridine infrequently.
PMID- 10690203
TI - Reproductive features of the eastern mole (Scalopus aquaticus) and star-nose mole
(Condylura cristata).
AB - Since moles are closely related to shrews, the gametes and reproductive tracts of
the star-nose mole (Condylura cristata) and the eastern mole (Scalopus aquaticus)
were examined to gain further insight into unusual reproductive traits of the
Soricidae. Moles display many of these soricid traits, but with some important
differences. The cumulus oophorus of Scalopus, ovulated about 16 h after hCG
injection, was largely dispersed by hyaluronidase and, though quite dense, was
nevertheless more similar to that of higher mammals than to the compact 'ball of
the soricid cumulus. Within the female tract in these moles, approximately 85% of
the length of the oviduct comprises a narrow ampulla with numerous differentiated
crypts that, in shrews, house spermatozoa. However, in contrast to shrews, moles
produce considerably larger numbers of spermatozoa, which challenges the proposal
that, in shrews, oviductal sperm crypts specifically permit lower sperm
production by the males. In the sperm head of these two moles, the acrosome
displays the long rostrum that is typical of other Insectivora, and the
perforatorium has the barbs by which soricid spermatozoa probably bind to the
zona pellucida. Perhaps allied to this, immunoblots indicated that the
immunoreactive acrosomal matrix of Scalopus spermatozoa is simpler than the
polypeptide complex of the bovine and hamster acrosomal matrix.
PMID- 10690204
TI - Examination of the relative role of FSH and LH in the mechanism of ovulatory
follicle selection in sheep.
AB - The GnRH-antagonist suppression-ovarian autotransplant model (n = 18) was used to
examine the relative roles of temporal changes in FSH and LH stimulation on
follicle development and selection. Follicle development was stimulated by
infusion with oFSH for 3 days and treatments applied for 60 h after progestagen
sponge withdrawal and before delivery of an ovulatory stimulus. In Expt 1, there
was continuous infusion of FSH with or without small amplitude high frequency LH
pulses, or withdrawal of FSH with or without pulsatile LH. In Expt 2, there was
acute or gradual withdrawal of FSH at sponge withdrawal with pulsatile LH. The
patterns of follicle development and basal and pulsatile ovarian hormone
secretion were determined. The maintenance of FSH throughout the artificial
follicular phase resulted in multiple follicle development and ovulation (3.3 +/-
0.3). Pulsatile LH stimulated steroid secretion (P < 0.001) but had little effect
on ovulation rates (3.8 +/- 0.8) when FSH was maintained. However, withdrawal of
FSH in the absence of LH resulted in atresia of the ovulatory follicles and
anovulation whereas, when FSH was withdrawn in the presence of LH, preovulatory
follicle development was maintained in some animals (3/6 and 5/9 in Expts 1 and
2, respectively) and these ewes had lower (P < 0.05) ovulation rates (1-2
ovulations per ewe). When FSH was withdrawn gradually in the presence of
pulsatile LH, 9/9 animals ovulated with ovulation rates in the normal range.
These results indicate that ovulatory follicles can transfer their gonadotrophic
dependence from FSH to LH. It is hypothesized that the ability of a follicle to
respond to this switch in gonadotrophic support is central to the mechanism of
follicle selection.
PMID- 10690205
TI - Growth and cellular proliferation of pig corpora lutea throughout the oestrous
cycle.
AB - Corpora lutea were obtained from gilts on days 2, 4, 8, 12, 15 or 18 after
oestrus. Luteal fresh masses and DNA contents increased linearly (P < 0.01) from
day 2 to day 12 and day 2 to day 15, respectively. Changes in the ratio of
protein:DNA were greatest between days 2 and 4 and days 15 and 18, whereas
changes in DNA content were relatively small during the same intervals. Thus, a
major component of changes in the size of the corpus luteum during the early and
late periods of the luteal phase was cellular hypertrophy. Proliferation of
luteal cells in vivo (nuclear incorporation of 5-bromo-2-deoxyuridine, a
thymidine analogue) was greatest on day 2 and decreased exponentially (P < 0.01)
throughout the oestrous cycle. Results from co-localization of 5-bromo-2
deoxyuridine and factor VIII (von Willebrand factor), a marker of endothelial
cells, or 5-bromo-2-deoxyuridine and 3 beta-hydroxysteroid dehydrogenase, a
marker of steroidogenic cells, indicated that some of the luteal steroidogenic
cells proliferated early in luteal development. However, during early and mid
cycle, most of the luteal cell proliferation occurred in the endothelial cells.
Thus, during growth of the pig corpus luteum, which is extremely rapid, most of
the proliferating luteal cells are vascular endothelial cells. This observation
is consistent with the high vascularity and blood flow of the mature corpus
luteum and implies a critical role for angiogenesis in luteal development in the
pig, as has been proposed for several other mammalian species.
PMID- 10690206
TI - Inhibition of ovulation by tyrosine kinase inhibitors in the in vitro perfused
rat ovary.
AB - Protein tyrosine kinase activity, leading to tyrosine phosphorylation of the
intracellular domains of receptors or non-receptor proteins, is an important
feature of downstream signalling after receptor binding of a variety factors,
such as growth factors and cytokines. Since several members of these classes of
paracrine-autocrine mediator may be involved in the intraovarian events of
ovulation, the present study was designed to evaluate the effect of protein
tyrosine kinase inhibition on the in vitro perfused rat ovary. Immature rats were
primed with 20 iu pregnant mares' serum gonadotrophin 48 h before surgical
isolation of the right ovary with connecting vasculature. The ovary was placed in
a perfusion system for either 10 h, to examine ovarian concentrations of the
established ovulatory mediators plasminogen activator, prostaglandins E2 and F2
alpha, or for 20 h, enabling a complete ovulatory process to occur in vitro.
Ovulation was induced by ovine LH (0.2 microgram ml-1) in the presence of the
phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.2 mmol l-1) and the
effects of two different protein tyrosine kinase inhibitors, genistein and
tyrphostin A25, were studied. Unstimulated control ovaries did not ovulate and
showed low secretion of progesterone and oestradiol. Addition of LH + 3-isobutyl
1-methylxanthine resulted in a marked stimulation of steroid release, and
ovulations occurred in all ovaries (9.0 +/- 0.9; mean +/- SEM). The protein
tyrosine kinase inhibitors, genistein and tyrphostin A25, significantly inhibited
ovulation at the higher concentrations tested (3.0 +/- 0.3 at 100 mumol genistein
l-1; 5.8 +/- 1.0 at 500 mumol tyrphostin A25 l-1) but no effect was seen at lower
concentrations. The presence of genistein and tyrphostin A25 at any concentration
used did not significantly decrease the LH + 3-isobutyl-1-methylxanthine-induced
progesterone or oestradiol concentrations. The intraovarian concentrations of
plasminogen activator activity, and prostaglandin E2 and F2 alpha were not
altered by the presence genistein (100 mumol l-1). In conclusion, the results of
the present study indicate that protein tyrosine kinase signalling pathways are
integral parts of the mammalian ovulatory process but do not involve actions on
the synthesis of steroids, plasminogen activator or prostaglandins.
PMID- 10690207
TI - Bromocriptine-induced premature oestrus is associated with changes in the
pulsatile secretion pattern of follicle-stimulating hormone in beagle bitches.
AB - The secretory profiles of LH and FSH were investigated before and during the
administration of bromocriptine in six beagle bitches. Plasma samples were
obtained via jugular venepuncture at 10 min intervals for 6 h every 2 weeks until
the next ovulation. Bromocriptine treatment was started 100 days after ovulation.
Both before and after bromocriptine treatment, LH and FSH pulses occurred
together. The mean duration of the FSH pulse (120 min) was significantly longer
than that of the LH pulse (80 min). The interoestrous interval in the bitches
treated with bromocriptine was significantly shorter than that of the preceding
cycle (160 +/- 3 versus 206 +/- 24 days). The mean basal plasma FSH concentration
(7.4 +/- 0.6 versus 6.1 +/- 0.7 iu l-1) and the mean area under the curve for FSH
(46.6 +/- 4.7 versus 40.4 +/- 4.4 iu l-1 in 6 h) increased significantly after
the start of the bromocriptine treatment. In contrast, the differences in mean
basal plasma LH concentration (2.1 +/- 0.2 versus 2.0 +/- 0.2 micrograms l-1) and
the mean area under the curve for LH (19.0 +/- 3.1 versus 19.5 +/- 2.5 micrograms
l-1 in 6 h) between the day before and 14 days after the start of the
bromocriptine treatment were not significant. Bromocriptine administration also
lowered the mean amplitude of the FSH pulse and shortened the mean duration of
the FSH pulse, without influencing the LH pulse. In addition to demonstrating the
concurrent pulsatile secretion of LH and FSH, the results of the present study
demonstrate that the bromocriptine-induced shortening of the interoestrous
interval in the bitch is associated with an increase in plasma FSH concentration
without a concomitant increase in plasma LH concentration. This finding indicates
that treatment with the dopamine agonist bromocriptine increase plasma FSH to a
concentration that results in the enhancement of follicle development.
PMID- 10690208
TI - Disulfide formation in bovine zona pellucida glycoproteins during fertilization:
evidence for the involvement of cystine cross-linkages in hardening of the zona
pellucida.
AB - The time for solubilization of the bovine zona pellucida in a hypotonic buffer
containing 5% (v/v) beta-mercaptoethanol and 7 mol urea l-1 increased by 10%
after fertilization. Coupling with a specific fluorescent thiol probe,
monobromobimane (mBBr), was markedly greater in the zona pellucida of ovarian
eggs compared with fertilized eggs, indicating that the cysteine residues in the
zona pellucida of unfertilized eggs are oxidized to cystines during
fertilization. After endo-beta-galactosidase digestion to remove N
acetyllactosamine repeats of the carbohydrate chains, three zona pellucida
glycoproteins (ZPA, ZPB and ZPC) coupled with the fluorescent bimane groups were
fractionated efficiently by reverse-phase HPLC. Estimation of bimane groups in
the three components and SDS-PAGE revealed that intramolecular disulfide bonds in
ZPA and intra- and intermolecular disulfide bonds in ZPB were formed during
fertilization, but oxidation of cysteine residues in ZPC was low. Specific
proteolysis of ZPA during fertilization was also observed. These results indicate
that the formation of disulfide linkages together with specific proteolysis
result in the construction of a rigid zona pellucida structure, which is
responsible for hardening of the zona pellucida.
PMID- 10690209
TI - Sex ratio bias in postpartum-conceived Norway rat litters is produced by
embryonic loss in midpregnancy.
AB - In rats, dams that conceive in their postpartum oestrus and then lose their
firstborn litter bias the sex ratio of the litter toward females in utero. The
present study identifies the source of litter sex ratio bias in these postpartum
pregnant non-lactating dams. The female bias arises first through the
postconception loss of embryos, and second, the loss occurs in midpregnancy
between the attachment of the blastocyst to the uterine wall on day 5 and full
metrial gland development on day 14. Some pregnancies were restricted to one
uterine horn to see if this loss (and thus the opportunity for litter sex ratio
biasing) was influenced by local factors operating within the uterine horn.
Embryonic loss was more closely associated with the number of embryos implanting
in a single horn than with the number implanting in the litter, demonstrating
that local crowding within a horn is sufficient for the preferential loss of male
embryos. This loss did not cause an obvious decrease in the size of the live-born
litter because only those horns with a surfeit of embryos lost them. This process
was the same in the right and left horns; both carried and lost the same numbers
of embryos. A dam that conceives in her postpartum oestrus and then loses her
suckling litter forgoes the implantation delay and uterine healing caused by
lactation. Male embryos are less successful at implanting in a uterus only
recently vacated by a previous litter.
PMID- 10690210
TI - Rotavirus, poliovirus top 1999 immunization changes.
PMID- 10690211
TI - Newly approved abacavir to carry hypersensitivity warning.
PMID- 10690212
TI - Medicare pays twice the VA cost for drugs, report says.
PMID- 10690213
TI - Preparing pharmacy technicians for patient-focused care.
PMID- 10690215
TI - Evidence-based medicine for children.
PMID- 10690214
TI - St. John's wort: Hypericum perforatum.
PMID- 10690216
TI - Stability of rifabutin in two extemporaneously compounded oral liquids.
AB - The stability of rifabutin 20 mg/mL in two oral liquids was studied. Powder from
100 150-mg rifabutin capsules was placed in a glass mortar. Cherry syrup (pH 2.9)
or a 1:1 mixture of Ora-Sweet and Ora-Plus (Paddock Laboratories) was added to
produce 750 mL of each formulation, which was then stored in 2-oz plastic
prescription bottles. Three bottles of each formulation were stored at 4, 25, 30,
and 40 degrees C. At 0, 1, 2, 4, 8, and 12 weeks, the bottles were collected and
allowed to remain at room temperature for one hour; samples of about 1 mL were
collected from each bottle, weighed, and assayed for rifabutin content by high
performance liquid chromatography. The rifabutin liquids prepared with cherry
syrup and stored at 4, 25, and 30 degrees C lost a mean of < 8% of the initial
drug concentration during the 12-week study; at 40 degrees C, the liquids lost >
10% of the initial drug concentration by 12 weeks. There was a mean loss of < 5%
of the initial rifabutin concentration in all the liquids prepared with Ora-Sweet
and Ora-Plus. The liquid prepared with cherry syrup, upon standing, showed a
tendency for some of the ingredients to float. The suspension prepared with Ora
Sweet and Ora-Plus had a tendency to retain bubbles after it was shaken, but the
ingredients did not settle upon standing. Rifabutin 20 mg/mL in two
extemporaneously compounded oral liquids prepared from capsules and sweetened
vehicles was stable for at least 12 weeks at 4, 25, 30, and 40 degrees C with the
exception of rifabutin in cherry syrup, which was stable for only 8 weeks at 40
degrees C.
PMID- 10690217
TI - Clinical research: national survey of U.S. pharmacy-based investigational drug
services--1997.
AB - The results of a survey on the status of pharmacy-based investigational drug
services and ways in which some institutions have adapted to recent changes that
may affect research are presented. A 99-item survey on investigational drug
services was sent in February 1997 to pharmacy directors at 1495 hospitals
affiliated with teaching institutions throughout the United States. The survey
covered workload, inpatient and outpatient pharmaceutical services, marketing of
services, quality assurance, committee involvement, funding sources,
computerization, and educational activities. The response rate was 21%; 68% of
the respondents were from sites involved in dispensing drugs used for clinical
research, with pharmacies at larger hospitals being more likely to dispense
investigational drugs than pharmacies at smaller hospitals. The pharmacies
participated in a mean 51 active protocols for every full-time-equivalent
employee budgeted to research protocols. The correlation between staffing level
and number of protocols was high. The service provided most often was the
maintenance of drug accountability records for study drugs dispensed to
inpatients and outpatients. There was wide variation in the types of services
provided to researchers by the pharmacies. Basic services, such as dispensing and
inventory control, were provided by nearly all the pharmacies, whereas more
specialized services tended to be provided more often at institutions more
heavily committed to research. Pharmacy-based investigational drug services at
hospitals affiliated with teaching institutions offered basic services, such as
dispensing and inventory control, almost universally and offered specialized
services to varying degrees.
PMID- 10690218
TI - Clinical research: ASHP guidelines and future directions for pharmacists.
AB - ASHP guidelines on the pharmacist's role in clinical drug research and future
directions for pharmacists in clinical drug research are described. Health-system
pharmacists have a responsibility to the patient and to the institution to ensure
that clinical research systems are sound, that patients are protected, and that
research is conducted in a safe, effective way. ASHP guidelines list minimum
standards that are essential for improving performance. The ASHP Guidelines on
Clinical Drug Research, approved in November 1997, update information previously
found in the ASHP Guidelines for the Use of Investigational Drugs in Organized
Health-Care Settings, approved in 1990, but have an expanded focus. Additions
include recognition of relevant business practices, implications of technology,
and the expansion of clinical research beyond the academic health center. At a
minimum, all pharmacists involved in clinical research should handle the record
keeping for drug accountability, provide drug information to patients and to
other health care providers, ensure the appropriate care of patients at sites not
involved in the study, and provide accountability at nonpharmacy locations.
Managing and coordinating clinical drug research is an area of growth that
represents a great opportunity for clinical drug research. By providing baseline
and higher-level pharmaceutical services for clinical research projects,
pharmacists can help to ensure data accuracy and completeness and patient safety.
PMID- 10690219
TI - ASHP Therapeutic Guidelines on Stress Ulcer Prophylaxis. ASHP Commission on
Therapeutics and approved by the ASHP Board of Directors on November 14, 1998.
PMID- 10690220
TI - Azithromycin-induced hearing loss.
PMID- 10690221
TI - Incompatibility of ceftriaxone sodium with lactated Ringer's injection.
PMID- 10690222
TI - [Early detection and intervention of hypoacusia in childhood. Is it a time to
change?].
PMID- 10690223
TI - [Ideals, plans and values in adolescence].
PMID- 10690224
TI - [Plan for the early detection and intervention of childhood hypoacusia].
PMID- 10690225
TI - [Testosterone treatment of delayed puberty: a longitudinal study in relation to a
control group].
AB - OBJECTIVE: Delayed puberty is a very common clinical situation that affects a
great number of adolescents. We analyzed the effects that testosterone therapy
produces in this situation, including the start of puberty and, therefore,
lessening the psychological effects that this delay causes. PATIENTS AND METHODS:
We carried out a longitudinal study, in which we followed the growth and
maturation of 32 boys from the age of 14 to 19 years. The sample was divided into
a control group (n = 17) and a treatment group (n = 15). The treatment group
received 50 mg/month of testosterone enantate depot during 6 months. None of the
subjects, neither in the control group nor in the treatment group, had started
puberty or if so, they had started it in an insufficient way for their age.
RESULTS: The boys treated with testosterone developed a greater growth velocity
compared to the control group during the first year of observation (9.07 +/- 1.11
cm/year vs 6.9 +/- 1.76, respectively, p < 0.0001). They had a higher increment
in the muscular area of the arm (p < 0.005) and pubertal stage G changes occurred
more quickly. On the other hand, the growth of the testicular volume was similar
in both groups. At 19 years of age, no significant difference between the groups
was observed in any of the clinical parameters studied. CONCLUSIONS: Treatment
wit testosterone at the dose used promotes a significant response that leads to
the start of puberty, but without stopping the maturation of the hypothalamic
pituitary axis that is produced in normal puberty, allowing a normal testicular
evolution. The treatment does not show any long-term effects. It is, therefore,
an effective treatment of delayed puberty.
PMID- 10690226
TI - [Surgical correction of symptomatic ventricular septal defects in patients less
than 6 months of age].
AB - OBJECTIVE: Our objective was to evaluate the efficiency of a single surgical
intervention in patients with symptomatic interventricular septal defects during
the first six months of life. PATIENTS AND METHODS: Between 1989 and 1997, 42
patients, 20 males and 22 females with an average age of 3.9 +/- 0.3 months and
an average weight of 4 +/- 0.4 kg, were operated. Seven suffered from Down's
syndrome. All of the patients became symptomatic during the first two months of
life. The defect was localized by using Echo-Doppler in all of the cases. Thirty
six had perimembranous ventricular septal defects, 2 were muscular, 3 multiple
and 1 was infundibular. The average defect size was 8 +/- 1.2 mm. A catheter was
placed in 34 patient with the following results: Left to right shunt with 2.2 +/-
1.2, right ventricle systolic pressure of 57 +/- 20 mmHg (16 with systemic
pulmonary pressure) and an average pulmonary pressure of 38 +/- 1.8 mmHg. The
average pulmonary vascular resistance was 28 +/- 1.8 U/m2. Deep hypothermia (18
degrees C was applied during the surgery and the average cardiac arrest time was
31 +/- 4 minutes. RESULTS: None of the patients died during or after the surgical
procedure. Patients required minimum ionotropic support during the first hours.
The average time in the intensive care unit was 3.5 +/- 0.6 days, with an average
hospitalization time of 11.2 +/- 2.1 days. Immediate complications included one
hypertensive crisis, four junctional ectopic tachycardias, two atrio-ventricular
blocks, 1 transient arrhythmia, two atelectasia-pneumonias, two patients with
stridor and two sternal infections. During the follow-up period, two patients
required a second intervention to repair the patch. CONCLUSIONS: We believe that
one-time surgery is adequate to correct symptomatic ventricular septal defects.
PMID- 10690227
TI - [Polydactyly of the hand and foot].
AB - OBJECTIVE: Our aim was to establish the differences between polydactyly of the
hand, the foot and those affecting both the hands and feet. PATIENTS AND METHODS:
One hundred twenty-five cases of hand polydactyly (HP), 105 of foot polydactyly
(FP) and 25 cases of combined hand and foot polydactyly (HFP) were reviewed. We
differentiated between preaxial, postaxial, axial and peculiar polydactyly and a
group constituted by all other non-preaxial location (OTHERL) was also formed. In
all patients the following parameters were analyzed: sex, laterality, antecedence
of malformation in the family (FAANT) and the existence of other malformations
(OTHERM). RESULTS: Polydactyly was commonly preaxial in the hand (72%), OTHERL in
the foot (64.7%) and equally located in hands and feet in HFP, with the most
frequent being postaxial/postaxial combination (36% of the cases). Bilaterality
is rare in preaxial HP (3.3% versus 77.7% of right unilaterality) and remarkable
in OTHERL (54.2%). Bilaterality is greater in preaxial FP (64.8%) and strongly
marked in HFP, which accounts for 72% of hands and 80% of feet. There is a slight
global dominance of males in all forms. The existence of FAANT is higher in
OTHERL in the hand (45.7% versus 34.4% in preaxial) and in preaxial of the foot
(45.9% versus 25% in OTHERL), being very high (48%) in HFP. The coexistence with
other malformations, either in the hand or foot, is higher in OTHERL.
PMID- 10690228
TI - [Reference values for thyroid hormones, thyrotropin and thyroglobulin in healthy
children of Zaragoza].
AB - OBJECTIVE: The purpose of this study was to estimate the basal serum
concentration reference values for total T3 (T3), total T4 (T4), free T4 (FT4),
thyrotropin (TSH) and thyroglobulin (Tg) in healthy children of Zaragoza.
PATIENTS AND METHODS: Healthy children aged 0 to 14, with normal weight and
height, living in the metropolitan area of Zaragoza (Spain) were the reference
population of this transversal study. Basal serum concentrations of T3, T4 and
FT4 were measured by radioimmunoassay and of TSH and Tg by immunoradiometric
assay. Reference values and ranges were estimated according to the
recommendations of the International Federation of Clinical Chemistry. RESULTS:
Reference values have been classified according to age, sex and pubertal stage.
There are differences in T3, T4, FT4 TSH and Tg concentrations during the
prepubertal period according to age, but not to sex, and between the prepubertal
period and puberty. Sex and Tanner stage influence T3 and T4 concentrations
during puberty. CONCLUSIONS: Since there are differences in T3, T4, FT4, TSH and
Tg reference values according to age, sex, pubertal stage and immunoassays, it is
necessary to establish reference values for every population and laboratory in
accordance with these parameters.
PMID- 10690229
TI - [Prevalence of symptoms suggestive of allergic rhinitis and atopic dermatitis in
adolescents (Spanish ISAAC Study Group)].
AB - OBJECTIVE: There is a great concern about the worldwide prevalence of allergic
disturbances in children and their assumed increase. In order to clarify these
facts, the International Study of Asthma and Allergy in Children (ISAAC) group
carried out a similar survey in 56 countries, including 463,801 adolescents. We
report results of rhinoconjunctival and cutaneous allergies obtained from the 9
centers of the Spanish ISAAC group. PATIENTS AND METHODS: The questionnaire was
directly translated from the English text and self-answered by 27,407
schoolchildren between 13-14 years of age from Almeria, Barcelona, Bilbao, Cadiz,
Cartagena, Castellon, Pamplona, Valencia and Valladolid. An Epi-Info software was
used to assess contingency tables and odds ratios. RESULTS: Only 9.4% of the
adolescents said that they had ever suffered hay fever or allergic rhinitis,
although 31.3% had nasal symptoms with allergic characteristics during the last
12 months and they were associated with conjunctival disorders in 15.4%. Of these
teenagers, 10.3% had ever had atopic dermatitis and 6.2% continued to have active
symptoms during the last 12 months. Severe forms were uncommon (0.7%). The female
gender had high risk for nasal symptoms during the last 12 months (OR: 1.11; IC
95%: 1.11-1.17) and even higher for atopic dermatitis (OR: 1.3; IC 95%: 1.28
1.37). The frequency of rhinoconjunctivitis and cutaneous disturbances was
different in the 9 centers. CONCLUSIONS: We found differences in the prevalence
of rhinoconjunctival and cutaneous atopic disorders between centers throughout
Spain and now an investigation of the causes is needed. The diagnosis of atopic
dermatitis was well recognized by adolescents (10.3%), on the contrary, they
frequently (31.3%) reported nasal symptoms with the allergic characteristics but
nevertheless do not identify them as such.
PMID- 10690230
TI - [Long-term development of children with Schonlein-Henoch purpura associated with
anti-neutrophil cytoplasmic antibodies].
AB - OBJECTIVE: The purpose of this study was to assess the frequency of
antineutrophil cytoplamic antibodies (ANCA) in Schonlein-Henoch purpura (SHP) and
its long-term significance. PATIENTS AND METHODS: IgG and IgA classes of ANCA
were studied by indirect immunofluorescence (IIF) and IgG-ANCA against
myeloperoxidase (MPO) and against proteinase-3 (PR-3) were determined by ELISA in
50 children with SHP. Eight (16%) of the patients had renal involvement during
the acute phase, but none had a permanent nephropathy after a 7-17 year follow
up. RESULTS: Positive IgG ANCA were found in 5 (10%) of the cases and only one of
these children also had IgA ANCA. The ELISA against MPO and P-3 was negative in
all patients. None of the 5 patients with ANCA showed nephropathy during the
acute phase nor relapses or permanent nephropathy. CONCLUSIONS: A minority of
children with SHP are positive for ANCA and, in the absence of nephropathy, this
is not associated with a bad long-term prognosis.
PMID- 10690231
TI - [Invasive catheters in neonates].
AB - OBJECTIVE: The care of very sick babies requires the use of invasive catheters in
the neonatal intensive care unit. Our objective was to review the invasive
catheters placed (umbilical and epicutaneous) between 1994 and 1998 and describe
the guidelines used to take care of the intravenous lines. PATIENTS AND METHODS:
Two periods were compared (January 1994 until June 1997 and July 1997 until
September 1998) and characteristics of the patient and catheter were analyzed.
During the first period, sepsis related to the catheter was diagnosed according
to clinical and analytical criteria and required a positive blood culture. The
same criteria were required in the second period, but coincidence of the
organisms in the peripheral and catheter blood culture was also needed. RESULTS:
A total of 1,285 central catheters were studied in 958 newborn admissions.
Umbilical catheter were used in 6% of the cases and epicutaneous in 23%, most of
which were in the upper extremities. The most frequent reason to remove the
catheter was the end of the indication. The incidence of catheter related sepsis
in the first period was 1% and during the second period 6%. Strict diagnostic
criteria used in the second period were more predictive for sepsis. If premature
babies were considered alone, the incidence increased to 14%. The most frequent
organism isolated was Staphylococcus epidermidis. CONCLUSIONS: To decrease the
incidence of sepsis related to catheters, a strict protocol for placement and
maintenance must be followed.
PMID- 10690232
TI - [Epidemiological study of Steinert's congenital myotonic dystrophy:
dysmorphological characteristics].
AB - OBJECTIVE: Steinert's congenital myotonic dystrophy (CMD) is a systemic disease
with autosomal mother-to-child transmission and characterized by generalized
hypotonia, areflexia, facial diplegia, respiratory and alimentary diseases,
arthrogryposis, polyhydramnios, etc. We present the study of the clinical and
epidemiological characteristics of Steinert's CMD in our population, with special
attention to its dysmorphological features. PATIENTS AND METHODS: In this study
we present the analysis of 12 cases of Steinert's CMD identified among 26,956
infants with congenital defects registered by the Spanish Collaborative Study of
Congenital Malformations (ECEMC) between April 1976 and March 1998. RESULTS: The
minimum estimation of the prevalence in our population is 0.08 per 10,000 live
births. We have epidemiologically observed in newborns with Steinert's CMD the
presence of a statistically significant difference in the following variables:
lower gestational age and birth weight, more polyhydramnios, more feet
presentations and Cesarean sections, and a higher frequency of similar congenital
defects in first degree relatives. The congenital defects most frequently
associated to our population of CMD are located in the extremities, the head and
face. CONCLUSIONS: It is important to recognize the congenital defects associated
with neuromuscular disorders in the neonatal period, and particularly, the wide
spectrum of Steinert's CMD that results in a fetal hypokinesia deformation
sequence.
PMID- 10690233
TI - [Fibrous hamartoma in children. Report of one case].
PMID- 10690234
TI - [Macrocephaly-cutis marmorata telangectasica congenita: another case of a newly
recognized entity].
PMID- 10690235
TI - [Gastric bezoar of cotton swabs].
PMID- 10690236
TI - [Unilateral megalencephaly].
PMID- 10690237
TI - [Intra-thoracic cystic tumors in a newborn].
PMID- 10690238
TI - [Guidelines of basic, advanced and neonatal cardiopulmonary resuscitation (II):
basic cardiopulmonary resuscitation in pediatrics. Spanish group of Pediatric and
Neonatal Cardiopulmonary Resuscitation].
PMID- 10690239
TI - Should nutrition be considered as a supplementary measure in schistosomiasis
control?
AB - The most important data on the relationships between nutritional status and
schistosomiasis mansoni are reviewed. The probable impact of such findings on the
traditional strategies for control of the disease are discussed. In endemic
areas, malnutrition and schistosomiasis seem to be associated. Malnutrition
impairs the biological development of the parasite. However, like the parasite,
it also depresses the host's immune system, and malnutrition and infection can be
mutually aggravating. Recent schistosomiasis-control activities, although
apparently well designed, have frequently seemed ineffective because of the
multiplicity of factors involved, and have not offered a realistic promise of
sustainable and definitive control. However, these actions must be continued and
even encouraged because they do lead to reductions in the prevalence of infection
and, of particular importance, to reductions in the incidence of the more severe
forms of the disease. Improvement of the nutritional status of those who inhabit
endemic areas, particularly those on low incomes (who are at relatively high risk
of malnutrition and of schistosomiasis), is recommended as a supplementary
measure.
PMID- 10690240
TI - Circulating receptors implicated in the cyto-adherence occurring in severe
Plasmodium falciparum malaria in Thailand.
AB - The kinetic profiles of soluble chondroitin-sulphate A (CSA), intercellular
adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and E
selectin were investigated in 17 patients hospitalized with Plasmodium falciparum
malaria. The aim was to see if these circulating adhesion molecules could be
considered as markers for the severity of P. falciparum malaria. The levels of
all the adhesion molecules were found to be higher in the sera from all the
malaria cases, both severe and uncomplicated, than in those from uninfected
controls. The elevation in plasma CSA, reported for the first time, was
statistically very significant (P = 0.00001). However, when severe cases were
compared with the uncomplicated, there were no significant differences in the
level of any of the receptors except ICAM-1, which was highest in those with the
severe disease (P = 0.01). The absence of any significant correlation between the
plasma concentration of CSA and malaria severity indicates that this adhesion
molecule could not be used to predict the severity of malaria, although its role
in sequestration of the parasites in pregnant women is well established.
PMID- 10690241
TI - Anaemia in pregnancy: Plasmodium falciparum infection is an important cause in
primigravidae in Hoima district, western Uganda.
AB - Infection with Plasmodium falciparum is a major cause of anaemia in pregnancy,
especially in primigravidae. Of 853 primigravidae visiting an antenatal clinic in
Hoima district, western Uganda, for the first time, 530 (62.1%) were found to
have P. falciparum parasitaemias and 305 (57.5%) of these had at least 1000
parasites/microliter blood. Plasmodium falciparum parasitaemia was significantly
associated with anaemia (relative risk = 0.84, with 95% confidence limits = 0.74
0.96; P = 0.01). Malarial parasites were detected in > 80% of the women who had
severe anaemia (P = 0.0008) and haemoglobin concentrations decreased with
increasing intensity of infection (P = 0.03). Malarial hyper-reactive
splenomegaly was associated with high parasite density (P = 0.01) and low
haemoglobin level (P < 0.0001). Effective measures aimed at prevention of malaria
and anaemia in pregnancy, especially in primigravidae, would significantly reduce
anaemia and its deleterious effects on both the mother and the baby.
PMID- 10690242
TI - Re-emergence of Plasmodium malariae in Trinidad, West Indies.
AB - A focus of Plasmodium malariae infection has recently occurred on the island of
Trinidad, some 30 years after a successful eradication programme. Examination of
bloodsmears revealed 22 cases of P. malariae in the Nariva-Mayaro area of
Trinidad between August 1994 and September 1995. Most (77%) of the cases were
male and, as seven were aged < 25 years of age, it appeared that transmission had
been renewed, probably by the vector Anopheles bellator. However, none of the
3000 mosquitoes tested by ELISA for the circumsporozoite protein of P. malariae
proved positive. Use of IFAT to check blood samples for P. malariae appeared more
sensitive than direct examination of bloodsmears, indicating that 42 (13%) of the
325 samples tested were seropositive (at titres of 1:256 or greater). The levels
of transmission of the parasite may therefore be even higher than indicated by
examination of bloodsmears. The surveillance measures adopted to understand the
epidemiology of this outbreak of P. malariae in Trinidad are described. The need
to maintain malaria surveillance in all the countries where P. malariae parasites
once existed (prior to eradication) is emphasised.
PMID- 10690243
TI - Malaria and the Narmada-river development in India: a case study of the Bargi
dam.
AB - The largest river-valley development to be proposed in India is that in the
Narmada valley. The building of the Bargi dam, a multi-purpose irrigation and
hydro-electric project, in Jabalpur, in central India, formed part of the first
phase of the development of this valley (1974-1988). Many villages and several
hectares of land in three districts were submerged as the waters rose behind the
dam, the worst affected area being the catchment area of the primary health
centre (PHC) at Narayanganj, in Mandla district. Until recently, cases of malaria
were relatively rare in Narayanganj. However, an epidemic of malaria in late 1996
claimed hundreds of lives in the area and the outbreak spread, during 1997, to
new villages in the region. A review of the records collected by the National
Malaria Eradication Programme (NMEP) not only indicated that the slide positivity
rate (SPR) for Narayanganj increased > 7.45-fold between 1979 and 1997 but also
that the slide falciparum rate (SFR) increased > 32-fold over the same period.
The NMEP data available for Mandla district as a whole indicated a doubling in
mean SPR and SFR between 1979 and 1997. There is no evidence that a new species
of vector has established since 1979. In fact, indoor-resting densities of
anophelines and of the most established vector, Anopheles culicifacies, have
fallen since the dam was built, but densities of another vector, An. fluviatilis,
have increased.
PMID- 10690244
TI - Schistosoma japonicum infection and serum and tissue concentrations of retinol
and zinc in pigs.
AB - The effects of Schistosoma japonicum infection on the concentrations of zinc in
serum, liver, spleen and muscle and on the concentrations of retinol in serum and
liver were studied in 48 pigs. Twenty-four of the pigs were each infected by
intramuscular inoculation with 2000 cercariae of S. japonicum in medium and the
rest were similarly inoculated with parasite-free medium, as controls. On each of
weeks 4, 11, 17 and 24 post-inoculation (PI), 12 pigs (six of which were
infected) were killed. Tissue samples were collected at necropsy. Blood samples
were taken prior to infection and at necropsy from all pigs, and bi-weekly from
the pigs killed 24 weeks post-infection. In an analysis of variance in which
serum retinol was the dependent variable, the interaction infection x time was
found to be significant (P = 0.009). The main reason for this significance was
that the concentration of retinol in the sera collected from infected pigs at
necropsy at 11 weeks PI was significantly lower than in the control pigs killed
at the same time (P = 0.02). Although, overall, infection led to higher zinc
concentrations in the liver (P = 0.04) and spleen tissue (P = 0.01), it had no
apparent effect on liver retinol, muscle zinc or serum zinc. However, among the
pigs which were tested bi-weekly, serum zinc was consistently lower in the
infected pigs than in the controls (P = 0.01). The transient declines seen in the
concentrations of retinol and zinc in sera from the infected pigs were not
accompanied by similar changes in the tissue concentrations, and may reflect an
acute-phase response to infection. Schistosoma japonicum infection in pigs is
considered a useful model of S. japonicum infection (and probably also of S.
mansoni infection) in humans. Similar effects, if they occur in the human
infections, may lead to misclassification of vitamin-A and zinc status in endemic
populations if this status is based on serum retinol and serum zinc.
PMID- 10690245
TI - Efficacy of albendazole and its combinations with ivermectin or
diethylcarbamazine (DEC) in the treatment of Trichuris trichiura infections in
Sri Lanka.
AB - The efficacy of the drugs currently available for treatment of infection with
Trichuris trichiura is low compared with that of the drugs used against roundworm
and hookworm. Single-dose combinations of albendazole with ivermectin or of
albendazole with diethylcarbamazine (DEC) have recently been seen to produce raid
and sustained reductions in Wuchereria bancrofti microfilaraemia. This
observation prompted the present study, on the efficacy of these combinations
against trichuriasis. The drug regimens tested were albendazole (400 mg) alone,
albendazole (400 mg) with ivermectin (200 micrograms/kg), and albendazole (400
mg) with DEC (6 mg/kg). Most (155) of the 176 children (4-14 years of age) who
each provided a single, pre-treatment, stool sample were found positive for
Trichuris ova. These 155 were each randomly allocated to one of the three
treatment groups and checked for infection 3 weeks post-treatment, again by a
single stool examination. Single-dose therapy with albendazole plus ivermectin
produced a 'cure rate' (79.3%) and an egg-reduction rate (93.8%) which were
significantly higher than the corresponding rates produced by albendazole alone
or albendazole plus DEC (P < 0.01 for each). The efficacies of albendazole with
DEC and of albendazole alone were statistically equivalent. Single-dose treatment
with the albendazole-ivermectin combination appears to be highly effective
against trichuriasis and could prove valuable for routine use.
PMID- 10690246
TI - Preventive immunisation could reduce the risk of meningococcal epidemics in the
African meningitis belt.
AB - Control of meningitis epidemics is based on early case detection followed by mass
campaigns of immunisation. However, this strategy showed severe inadequacies
during recent outbreaks in Africa. In Niamey, Niger, meningococcal vaccinations
began in 1978 and detailed bacteriological and epidemiological surveillance of
meningitis started in 1981. When vaccine coverage rates were higher than 50%, the
prevalences of Neisseria meningitidis A meningitis were low in Niamey, although
there was a concurrent epidemic in rural Niger. A massive outbreak of meningitis
in Niamey in 1994-1995 followed a 6-year period during which the mean rate of
vaccine coverage remained < 25%. The data indicate that, in the meningitis belt,
preventive immunization should avoid a great number of deaths and be less
expensive than mass immunisation campaigns performed after epidemics have begun.
PMID- 10690247
TI - The molluscicidal properties of Apodytes dimidiata (Icacinaceae): geographical
variation in molluscicidal potency.
AB - Synthetic molluscicides have proved too expensive for most countries wanting to
include snail control in their anti-schistosomiasis programmes. An alternative,
which is not only cheaper but also promotes self-reliance and empowerment of the
affected communities, is the use of molluscicidal plants. An often-cited
limitation to using such natural products is the geographical variation in the
toxicity of candidate species. The geographical variation in the molluscicidal
activity of Apodytes dimidiata was investigated in South Africa. Leaves of this
plant were collected from six, widely separate localities within the areas of the
country where schistosomiasis is endemic. The results of bio-assays using the
intermediate host snail, Bulinus africanus, clearly showed that variation in
toxicity did exist and appeared to be correlated with the range in mean annual
temperatures and altitude where the plants grew. Whether the variation was a
phenoplastic response to the environment or genetically determined still has to
be investigated. Nevertheless, a thorough knowledge of the geographical variation
in the level of the active compound(s) in the candidate plants in endemic areas
will be needed prior to the implementation of plant-propagation and snail-control
programmes.
PMID- 10690248
TI - Gross histopathological effects of an extract of Agave attenuata on the
epithelium of the digestive tract of Bulinus africanus.
AB - A lethal concentration of a crude, aqueous extract of Agave attenuata was applied
as a contact poison to Bulinus africanus, the intermediate host of Schistosoma
haematobium, for a 24-h period. The gross histopathological effects of the
extract on the epithelium of the digestive tract were then studied. A graded
series of cellular injuries to the epithelial layer was observed along the length
of the tract. These included the loss of cilia and brush border, disruption of
the epithelial layer, cellular vacuolation, swelling and rupture, and the
discharge of secretory products from mucous gland cells. The results of the
microscopy show that epithelial tissue is probably a primary target of the
molluscicide. The cytological injuries induced by extracts of A. attenuata
indicate that the molluscicide acts by disrupting the osmoregulatory mechanisms
of the epithelial cells, but further, detailed studies are required to confirm
this.
PMID- 10690249
TI - A prospective study of combination antimalarial therapy and of anaemia in Zambian
children with cerebral malaria.
PMID- 10690250
TI - Plasmodium falciparum infection following allogeneic bone-marrow transplantation.
PMID- 10690251
TI - High seropositivity against listeriolysin O in humans.
PMID- 10690252
TI - Measles: a disease that has to be eradicated.
AB - The incidence of measles is on the decline but it still claims the lives of one
million children annually worldwide. The devastating effects of the disease on
the health and nutrition of children in developing countries and its high
mortality are well documented. The rapid decay of maternal antibodies in infants
in developing countries results in early susceptibility to the disease and hence
the general recommendation to vaccinate at the age of 9 months. Sustained
international efforts have raised global vaccination coverage rates to around 80%
at which level it has remained static. Many countries in the western hemisphere
have eliminated the disease by adopting aggressive strategies, which include one
off 'catch-up' mass campaigns to vaccinate all children aged 1-14 years, 'mop-up'
campaigns targeting children who were missed during the 'catch-up' campaign,
efficient routine vaccination services capable of reaching 90% of infants, strong
surveillance activities, prompt outbreak response, and 'follow-up' campaigns
every 2-4 years which target 1-4-year-old children. This success story coupled
with the fact that measles has many biological features favouring eradication,
and considering that it is a severe and lethal disease still prevailing in many
areas, calls for immediate international adoption of eradication goals within a
specified period of time.
PMID- 10690253
TI - Paediatric hospital admissions at a South African urban regional hospital: the
impact of HIV, 1992-1997.
AB - Rates of infection by the human immunodeficiency virus (HIV) have been increasing
rapidly in South Africa over the last decade. This study documents the changes
over time in prevalence of HIV infection amongst hospitalized children, and its
effects on the profile of disease and in-hospital mortality over the period 1992
1997. Admissions to the paediatric medical wards between January 1992 and April
1997 were obtained from the routine computerized database held in the Department
of Paediatrics at Chris Hani Baragwanath Hospital. HIV tests were performed on
clinical indications only. Over the study period there were 22,633 admissions
involving 19,918 children. Total annual admissions increased by 23.6% between
1992 and 1996. Prevalence of HIV infection increased from 2.9% in 1992 to 20% in
1997. HIV-infected children had a younger age distribution, longer median length
of stay and more readmissions (p < 0.001) compared with HIV-negative and untested
children. HIV-infected children accounted for the increased number of admissions
for pneumonia, gastro-enteritis, malnutrition and tuberculosis, and the rise in
in-hospital mortality by 42% from 4.3% in 1992 to 6.1% in 1997. Paediatric HIV
infection has changed the profile of paediatric admission diagnoses and increased
in-hospital mortality in the relatively short time between 1992 and 1997. Over
the same period, HIV-negative children showed declining rates of malnutrition,
vaccine-preventable diseases and admission to the intensive care unit.
PMID- 10690254
TI - Knowledge of and attitudes to HIV/AIDS of senior secondary school pupils and
trainee teachers in Udupi District, Karnataka, India.
AB - A cross-sectional descriptive study using a questionnaire with mostly closed
ended questions was carried out on 990 pupils and 46 trainee teachers to
investigate their knowledge of and attitudes to HIV/AIDS. Pupils in one school
were reassessed after a health talk and distribution of a handout. Despite having
had no formal sex education, most respondents were reasonably well informed about
the transmission of HIV. However, there were many misconceptions about
transmission and prevention and 16.9% of pupils were found to possess very little
knowledge of HIV/AIDS. Mass media, teachers and health workers were quoted as the
main sources of knowledge. It was found that 24.3% pupils and 6.3% of trainee
teachers thought there was a cure, and 27.4% of pupils and 14% of trainee
teachers thought there was a vaccine to prevent HIV infection. Schools that were
rural, private and English-speaking scored better, as did male students and
schools teaching science. The necessity of formal sex education was expressed by
98.5% of pupils and all the trainee teachers. The pupils who were reassessed
after receiving a talk and handout showed significant improvement in their
knowledge and a change in attitude (p < 0.01). The mass media are important in
disseminating knowledge on HIV/AIDS in India but due to the lack of inter
personal approaches to the education system, knowledge is inadequate and
misconceptions exist.
PMID- 10690255
TI - Risk factors for an adverse outcome in bacterial meningitis in the tropics: a
reappraisal with focus on the significance and risk of seizures.
AB - The relationship of presentation to outcome in children with meningitis was
analysed. The relative risk (95% confidence interval) of an adverse outcome
(death or neurological sequelae) associated with presentation with at least three
of ten features (age < or = 2 yrs, ill for > 7 days, antibiotic treatment, focal
nerve deficits, abnormal posturing, abnormal muscle tone, lack of typical
meningeal signs, shock, unrousable coma and seizures) was 4.9 (2.7, 8.8), p <
0.0001. The first six features were particularly associated with neurological
sequelae, and shock and coma with death. Seizures were associated with either
outcome. Two seizure types could be distinguished: seizures which occurred before
or on diagnosis only (type I seizures) and seizures which occurred before and/or
after diagnosis (type II seizures). Death occurred in 0/41 children without
seizures and in 14/34 and 11/34 children with type I and type II seizures,
respectively (p < 0.0001). Neurological sequelae occurred in 3/42 children
without seizures and in 5/20 and 14/23 with type I and type II seizures,
respectively (p < 0.0001).
PMID- 10690256
TI - Sydenham's chorea: risk factors and the role of prophylactic benzathine
penicillin G in preventing recurrence.
AB - To determine the effect of prophylactic long-acting penicillin G in preventing
recurrence of Sydenham's chorea and to discover the risk factors associated with
occurrence of symptoms, 18 children with symptoms over a 5-year period were
prospectively identified. Of these, ten were boys and eight were girls. The
majority occurred between the ages of 8 and 10 years [mean (SD) 9.10 (2.62)
years]. Sydenham's chorea was generalized in 14 children and one-sided in four.
There was no difference in the incidence of right- and left-sided hemichorea.
Among the risk factors examined, only a history of chorea in relatives had a
significant association with the occurrence of Sydenham's chorea (OR = 6.39; 95%
CI 1.30-31.3). A comparison of recurrence between those given prophylactic long
acting penicillin G and those who had none showed a statistically significant
difference in the recurrence experience between the two groups (p < 0.02).
PMID- 10690257
TI - Intravenous immunoglobulin in very severe childhood Guillain-Barre syndrome.
AB - To evaluate intravenous immunoglobulin (IVIG) therapy in children with very
severe Guilain-Barre syndrome (GBS) with reference to the need for respiratory
support, ICU stay and long-term outcome, we studied 33 children with very severe
GBS and quadriparesis and/or respiratory muscle weakness admitted to the
Pediatric Intensive Care Unit (PICU) of PGIMER, Chandigarh. Cases (n = 22, IVIG
group) were enrolled prospectively, and controls (n = 11), similar to cases in
age and severity of illness, retrospectively. All children received similar
supportive and respiratory care. In addition, cases were given IVIG
(Sandoglobulin, Sandoz) 0.4 g/kg bodyweight per day for 5 days. The mean age,
duration of symptoms prior to admission and severity of illness in the two groups
were similar. In the IVIG group, onset of recovery of muscle power was
significantly earlier (day 14.8 (6.8) of illness vs day 20.9 (8.6), p < 0.05) and
the length of PICU stay significantly shorter (20.5 (13.0) days vs 50.5 (33.3)
days, p < 0.01). Sixteen (72.7%) children in the IVIG group had improved by at
least one functional grade after 1 month and 15 (68%) were walking independently
after 3 months compared with two (18%) and four (36%) controls, respectively (p <
0.05). The number of children who needed endotracheal intubation and mechanical
ventilation and the duration of mechanical ventilation was significantly less in
the IVIG-treated group. We conclude that in very severe GBS in children IVIG
therapy improves outcome to a remarkable extent, reduces the need for intubation
and mechanical ventilation, shortens the length of stay in ICU, and promotes
ambulation sooner.
PMID- 10690258
TI - Serum levels of measles IgG antibody activity in children under 5 years in Dar-es
Salaam, Tanzania.
AB - Measles IgG antibody levels were estimated in sera from 685 Tanzanian children,
374 (54.6%) boys and 311 (45.4%) girls aged 18 months to 5 years, using an enzyme
linked immunosorbent assay (ELISA). The children were screened for HIV-1 and 2
antibodies using ELISA, and reactive sera were confirmed by Western blot.
Nutritional status was assessed by anthropometry. Overall measles vaccination
coverage was 98.8%. Measles antibody activity was not detected in 41 (6.0%)
children, and ten (1.5%) had antibody levels below 200 mIU/ml, the cut-off level
considered to be protective. The non-reactive samples were from one unvaccinated
child, one child with unknown vaccination status and 39 vaccinated children.
Measles IgG antibody levels were higher in girls (3452.1 mIU/ml) than in boys
(2928.2 mIU/ml) (p = 0.02). Higher mean levels were found in children with a
history of low birthweight (< 2.5 kg) (p = 0.03). There were no significant
differences in measles antibody levels with regard to variations in nutritional
status. No correlation (r2 = 0.002) was found between antibody levels and time
elapsed since vaccination. In a multivariable logistic regression analysis,
children who were HIV-seropositive (n = 9) were more likely to have non
protective antibody levels < 200 mIU/ml (OR = 5.85; 95% CI: 1.37-24.93).
PMID- 10690259
TI - Comparative study of autonomic nervous system activity in malnourished and normal
children in India.
AB - Information on the relationship between autonomic functions and malnutrition in
children is scant. In the present study, autonomic function tests were conducted
in 30 normal subjects and 30 malnourished children aged between 5 and 10 years.
The tests performed included tests for parasympathetic functions (resting heart
rate, standing-to-lying ratio, lying-to-standing ratio and Valsalva ratio) and
tests to assess sympathetic function (hand grip test, galvanic skin resistance).
The malnourished children had significantly lower mean weights-for-age (-2.6 Z vs
-1.5 Z; p = 0.001), heights-for-age (-2.5 Z vs -1.5 Z; p = 0.001) and weights-for
height (-1.6 Z vs -0.8 Z; p = 0.001). Parasympathetic function tests evaluated
were significantly affected in malnourished children. Resting heart rate was
significantly higher in the malnourished group (90.6 vs 82.5/min; p = 0.001). The
other parasympathetic function tests had significantly lower mean values than in
the control group, namely, standing-to-lying ratio (1.25 vs 1.32; p = 0.026),
lying-to-standing ratio (1.23 vs 1.29; p = 0.021) and Valsalva ratio (1.26 vs
1.28; p = 0.037). Of the sympathetic function tests conducted, there were no
differences between the two groups for hand grip test but galvanic skin
resistance was significantly higher in the malnourished subjects (190.1 vs
149.73; p = 0.001). It is concluded that autonomic nervous system function is
significantly compromised in malnourished children.
PMID- 10690260
TI - Hydatid disease of the liver in children.
AB - Between 1986 and 1997, 21 children (ten boys and 11 girls) had surgery for
hydatid disease of the liver. Their mean age was 6.5 years (range 3-12).
Abdominal distention with a mass was the commonest presenting symptom (71.4%),
followed by abdominal pain (38%). Hepatomegaly with a palpable mass was present
in 12 (57%). Three children had concomitant pulmonary and brain hydatid disease.
The diagnosis was established clinically and by skin testing, serology and
imaging techniques. All patients received a pre-operative course of mebendazole
(50 mg/kg/day) for between 1 and 8 weeks. At surgery, 11 children had a single
cyst, eight of which were in the right lobe of the liver. Ten children had
multiple cysts occupying both liver lobes. Three forms of surgical treatment were
used: capitonnage + partial excision of fibrous capsule; total excision of the
cyst; and external drainage of the cyst cavity. Three children required re
operation. Mean follow-up time was 24 months. There were no deaths, but five
children developed post-operative complications. Surgical treatment in the form
of primary closure of the cyst cavity without drainage seems to offer the best
therapeutic option for patients with large hydatid cysts.
PMID- 10690261
TI - Sotos syndrome (cerebral gigantism): a clinical and radiological study of 14
cases from Saudi Arabia.
AB - Fourteen children (of Arab ethnic origin) with Sotos syndrome are described. They
were referred to King Khalid University Hospital, Riyadh between July 1992 and
June 1997. Their phenotypic characteristics were compared with established
diagnostic criteria. There was a male:female ratio of 1.3:1 and a high rate of
consanguinity (36%) among parents. At birth, 54% were large and about one-third
showed increased height and occipitofrontal head circumference (OFHC). The
neonatal histories revealed respiratory and feeding problems in 21%, followed
later by delayed motor milestones and speech development in 57%. During
childhood, weight, height and OFHC increased further to > 97th centile in 71%,
71% and 93%, respectively. A seizure disorder affected 43%, and 75% had mental
retardation (IQ < 70). A non-specific EEG abnormality was found in half of those
with seizures. Cranial CT/MRI showed ventricular dilatation in 15% and one
patient had corpus callosum dysgenesis. Abdominal ultrasound revealed
hydronephrosis in two patients. Radiological cephalometric measurements showed
relative prognathism in cases of Sotos syndrome compared with controls (p =
0.003). The study highlights the importance of considering Sotos syndrome in
children who present with psychomotor delay.
PMID- 10690262
TI - Cholecystitis in children in Zaria, Nigeria.
AB - Much has been published on cholecystitis in childhood from Europe and North
America but reports from tropical Africa are few. This is a report of seven
children with cholecystitis seen over a 10-year period in Zaria, northern
Nigeria. Six of the children had acalculous cholecystitis but a predisposing
condition (adenomatous hyperplasia) was identifiable in only one. Five presented
with complications (perforation, three; gangrene, one; empyema, one). One child
without haemolytic disease had calculous cholecystitis and choledocholithiasis.
Pre-operative diagnosis of cholecystitis was made in only three cases.
Cholecystectomy, two as interval procedures, was safely performed in all
patients. In environments such as ours, where cholecystitis in childhood is
uncommon, awareness and a high index of suspicion are necessary for early
diagnosis and prompt treatment in order to avoid potentially life-threatening
complications.
PMID- 10690263
TI - Salmonella cholecystitis in a neonate.
PMID- 10690264
TI - Benign recurrent intrahepatic cholestasis in a Saudi child.
AB - We report a case of benign recurrent intrahepatic cholestasis (BRIC) in an 11
year-old Saudi girl who developed three episodes of pruritus and jaundice at the
ages of 4, 8, and 9 years. These episodes were almost stereotypic and lasted 5-8
weeks. Although she had elevated liver enzymes and serum bile acids in her blood
during the attacks, they returned to normal between attacks. Thorough
investigation excluded other causes of liver disease and her recurrent attacks
were shortened by cholestyramine therapy. A diagnosis of BRIC should be kept in
mind in patients with cholestasis.
PMID- 10690265
TI - Influence of fibrinogen and haematocrit on erythrocyte sedimentation kinetics.
AB - This study investigates the influence of haematocrit, fibrinogen concentration
and fibrinogen availability (amount of fibrinogen per red blood cell) on
erythrocyte sedimentation. The Westergren technique was applied to blood samples
from 36 subjects and to their blood manipulated to haematocrits of 10, 20, 30 and
40%. Readings were taken every 10 minutes for 300 minutes. Previous studies
indicate that erythrocyte sedimentation occurs in three phases. In this study, we
show that haematocrit has little influence on either the rate of fall of
particles in the first phase (m1) or the duration of the first phase. This is
also true for fibrinogen availability and for fibrinogen concentration at low
haematocrits. At high haematocrits m1 increases with fibrinogen concentration.
The rate of fall of rouleaux during phase 2 (m2) and ESR60 both decrease
exponentially with haematocrit and increase linearly with fibrinogen
concentration. While m2 is more closely correlated to fibrinogen availability
than to fibrinogen concentration or to haematocrit, this is not the case for
ESR60. Thus haematocrit, fibrinogen concentration and fibrinogen availability are
more important to the velocity of sedimentation in the second phase than to the
sedimenting velocity during phase 1 or to the duration of phase 1.
PMID- 10690266
TI - Distributions of rheological parameters in populations of human erythrocytes.
AB - We have previously proposed the osmofiltration method based on a modified Hanss
hemorheometer to analyze distributions of erythrocytes in their ability to pass
through membrane filters with 3 microns pores. Upon decrease in medium osmolality
(u) the erythrocyte volume increases. When cell volume becomes V = Vcr at u =
ucr, such cell loses its ability to pass through a 3 microns pore. The flow rate
of erythrocyte suspension containing cells with different ucr through a filter
gradually decreases with decreasing medium osmolality. This rate becomes zero at
some u = omega, when the number of non-filterable cells in the applied sample
approaches the number of pores in filter. Experimental determination of the
dependencies of the filtration rate on medium osmolality for various hematocrit
values allows to obtain omega for each hematocrit and, thereby, to assess the
distribution of erythrocytes in ucr. Here, we propose a simplified version of
this method, which allows screening of the erythrocytes in heterogeneous
suspensions for the distribution in ucr by measuring omega for only two
hematocrit values, 0.1% and 1%. Applications of the proposed method are
exemplified by analysing the erythrocyte populations of healthy donors, of
patients with microspherocytosis, hemochromatosis and normal erythrocyte
populations in an acidic environment.
PMID- 10690267
TI - A new capillary viscometer for whole blood viscosimetry.
AB - A new capillary system was developed, incorporating infrared sensors, which
allowed the determination of whole blood viscosity over a wide range of shear
stresses. Flow conditions were defined by the geometry of the capillary and the
sample pressure head. Whole blood was considered to be a power law fluid and a
modified Mooney's formula was used for the calculation of the related invariants.
The new viscometer proved to be very simple in use, requiring one run, had a
short measuring time and utilised a small test sample volume. However it can be
used for whole blood viscosity measurements only at medium and high shear
stresses.
PMID- 10690268
TI - Mucus liquid crystallinity: is function related to microstructural domain size?
AB - The size of liquid crystalline domains formed in partially dried giraffe saliva
is found to be an order of magnitude greater than that previously documented for
slug pedal mucus. A correlation between (a) intrinsic liquid crystalline domain
size and (b) the scale of surface topography over which the mucus is required to
provide lubrication is postulated. The scale of mucus microstructure can be
related, via a simple model, to two significant material constants: the elastic
constant K for distortion of molecular alignment in the liquid crystalline state,
and the anchoring energy I at the liquid crystal/substrate interface. In turn,
the quantity K is expected to depend on fundamental molecular characteristics of
the constituent mucin, such as molecular weight and degree of glycosylation. The
possibility that observations of mucus microstructure might serve as a diagnostic
tool for mucus defects at the molecular level is suggested.
PMID- 10690269
TI - Theoretical study on flow-dependent concentration polarization of low density
lipoproteins at the luminal surface of a straight artery.
AB - It is suspected that physical and fluid mechanical factors play important roles
in the localization of atherosclerotic lesions and intimal hyperplasia in man by
affecting the transport of cholesterol in flowing blood to arterial walls. Hence,
we have studied theoretically the effects of various physical and fluid
mechanical factors such as wall shear rate, diffusivity of low density
lipoproteins (LDL), and filtration velocity of water at the vessel wall on
surface concentration of LDL at an arterial wall by means of a computer
simulation of convective and diffusive transport of LDL in flowing blood to the
wall of a straight artery under conditions of a steady flow. It was found that
under normal physiologic conditions prevailing in the human arterial system, due
to the presence of a filtration flow of water at the vessel wall, flow-dependent
concentration polarization (accumulation or depletion) of LDL occurs at a
blood/endothelium boundary. The surface concentration of LDL at an arterial wall
takes higher values than that in the bulk flow in that vessel, and it is affected
by three major factors, that is, wall shear rate, gamma w, filtration velocity of
water at the vessel wall, Vw, and the distance from the entrance of the artery,
L. It increases with increasing Vw and L, and decreasing gamma w hence the flow
rate. Thus, under certain circumstances, the surface concentration of LDL could
rise locally to a value which is several times higher than that in the bulk flow,
or drop locally to a value even lower than a critical concentration for the
maintenance of normal functions and survival of cells forming the vessel wall.
These results suggest the possibility that all the vascular phenomena such as the
localization of atherosclerotic lesions and intimal hyperplasia, formation of
cerebral aneurysms, and adaptive changes of lumen diameter and wall structure of
arteries and veins to certain changes in hemodynamic conditions in the
circulation are governed by this flow-dependent concentration polarization of LDL
which carry cholesterol.
PMID- 10690270
TI - Flow-dependent concentration polarization of plasma proteins at the luminal
surface of a cultured endothelial cell monolayer.
AB - Flow-dependent concentration or depletion of atherogenic low density lipoproteins
which has been theoretically predicted to occur at a blood/endothelium boundary
may play an important role in the genesis, progression, and regression of
atherosclerosis in man and intimal hyperplasia in vascular grafts implanted in
the arterial system in man and experimental animals. Hence to explore such a
possibility, we have studied the effect of a steady shear flow on concentration
polarization of plasma proteins and lipoproteins at the luminal surface of a
cultured bovine aortic endothelial cell (BAEC) monolayer which served as a model
of the vessel wall of an artery or an implanted vascular graft. The study was
carried out by circulating a cell culture medium containing fetal calf serum or
bovine plasma lipoproteins in steady flow through a parallel-plate flow cell in
which a cultured BAEC monolayer was installed, over the physiologic ranges of
wall shear rate and water filtration velocity at the BAEC monolayer. The water
(cell culture medium) filtration velocity at the BAEC monolayer was determined to
provide a measure of the change in concentration of plasma protein particles at
the luminal surface of the BAEC monolayer. It was found that for perfusates
containing plasma proteins and/or lipoproteins, water filtration velocity varied
as a function of flow rate, being lowest in the absence of flow. Water filtration
velocity increased or decreased as flow rate increased or decreased from an
arbitrarily set non-zero value, indicating that surface concentration of protein
particles varied as a direct function of flow rate, and the process was
reversible. It was also found that at particle concentrations equivalent to those
found in a culture medium containing serum at 20% by volume, plasma lipoproteins
which were much smaller in number and lower in concentration but larger in size
than albumin, showed almost the same effect as observed with serum which
contained both lipoproteins and albumin, indicating that the substance
responsible for this phenomenon is not albumin but lipoprotein whose diffusivity
is much smaller than that of albumin. The results strongly support our hypothesis
that flow-dependent concentration polarization of lipoproteins occurs at a blood
endothelium boundary, and this in turn promote the localization of various
vascular diseases which develop in our arterial system.
PMID- 10690271
TI - Flow-dependent concentration polarization of plasma proteins at the luminal
surface of a semipermeable membrane.
AB - The effect of steady shear flow on concentration polarization of plasma proteins
and lipoproteins at the luminal surface of a semipermeable vessel wall was
studied experimentally using suspensions of these molecules in a cell culture
medium and a semipermeable membrane dialysis tube which served as a model of an
implanted vascular graft or an artery. The study was carried out by flowing a
cell culture medium containing fetal calf serum or bovine plasma lipoproteins or
bovine albumin through a 7.5 mm diameter, 60 mm-long dialysis tube in steady flow
under a physiologic mean arterial perfusion pressure of 100 mmHg, and measuring
the filtration velocity of water (cell culture medium) at the vessel wall which
varied as a consequence of the change in concentration of plasma protein
particles at the luminal surface of the semipermeable membrane dialysis tube. It
was found that for perfusates containing plasma proteins and/or lipoproteins,
filtration velocity of water was the lowest in the absence of flow, and it
increased or decreased as the flow rate (hence wall shear rate) increased or
decreased from a certain non-zero value, indicating that surface concentration of
protein particles varied reversibly as a direct function of flow rate. It was
also found that at particle concentrations equivalent to those found in a culture
medium containing serum at 5% by volume, plasma lipoproteins which were much
smaller in number and lower in concentration but larger in size than albumin, had
a much larger effect on the filtration velocity of water than albumin. These
findings were very much the same as those previously obtained with a cultured
endothelial cell monolayer, strongly suggesting that the flow-dependent variation
in filtration velocity of water at a vessel wall results from a physical
phenomenon, that is, flow-dependent concentration polarization of low density
lipoproteins at the luminal surface of the endothelial cell monolayer.
PMID- 10690272
TI - Effect of alterations in femoral artery flow on abdominal vessel hemodynamics in
swine.
AB - In support of an in vivo investigation in swine of the influence of changes in
fluid dynamic wall shear on arterial macromolecular permeability, a procedure has
been developed to alter the flows in the porcine posterior arterial vasculature
by opening and closing a reversible arteriovenous shunt placed on one of the
femoral arteries. Laparoscopic techniques were used to place appropriately
modified Transonic Systems ultrasonic flow probes on both external and circumflex
iliac arteries, and on the terminal aorta. Flow measurements were made prior to
shunt placement, and with the shunt open and closed, to measure the influence of
altered external iliac artery flow on the distribution to the infrarenal
abdominal vessels. Similar experiments were carried out to relate the flow rates
in the external iliac arteries to those in the femoral arteries, which are more
accessible. Based on the relationships among the measured flow rates, rules have
been developed to estimate the major infrarenal flows in the pig, at baseline and
with the shunt opened and closed, from only the flow rates measured at the two
femoral arteries.
PMID- 10690273
TI - Linear viscoelastic model of a maturing gelatin solution.
AB - The linear viscoelastic model proposed in this work considers the viscoelastic
nature of maturing gelatin solutions through a relaxation modulus that depends on
temperature and maturation. This modulus is defined in the conceptual contexts of
the classical rubber elasticity theory and the rheometric gel theory. An analysis
of the relationship between the equilibrium elastic modulus and the percolation
variable around the gel point is also included yielding a percolation exponent
close to 1.7 as expected from previous theoretical predictions. Additionally, a
simple kinetic model is proposed to follow the microstructural changes obtained
as a consequence of the generation of junction zones, the number of which vary
with time during the dynamic rheometric tests used in this work. Thus, the
storage and loss moduli are measured at different temperatures and frequencies,
during the period of gelatin maturation. The theoretical aspects of the
rheological model are presented emphasizing the quantitative changes of
rheological parameters with the maturation.
PMID- 10690274
TI - Wasting away: what a waste: Part 3.
PMID- 10690275
TI - Na+/H+ exchange hyperactivity and myocardial hypertrophy: are they linked
phenomena?
PMID- 10690276
TI - Passive ventricular restraint.
PMID- 10690277
TI - The mitochondrial permeability transition and the calcium, oxygen and pH
paradoxes: one paradox after another.
PMID- 10690278
TI - Oxidative stress, F2-isoprostanes and endothelial dysfunction in
hypercholesterolemia.
PMID- 10690279
TI - Coming full circle: membrane potential, sarcolemmal calcium influx and excitation
contraction coupling in heart muscle.
AB - In heart muscle, strong evidence shows that excitation-contraction coupling
involves Ca-induced Ca-release. However, under some conditions, single heart
cells show Ca release and contraction which is not correlated with Ca entry via
the Ca channel, suggesting a second Ca-independent release mechanism. Similar
observations were made in early, pioneering studies using voltage-clamped multi
cellular preparations. We review the influence that experimental preparations and
conditions have had on excitation-contraction coupling theory over the last 20
years.
PMID- 10690280
TI - Functional heterogeneity of oxygen supply-consumption ratio in the heart.
AB - In this review, the regional heterogeneity of the oxygen supply-consumption ratio
within the heart is discussed. This is an important functional parameter because
it determines whether regions within the heart are normoxic or dysoxic. Although
the heterogeneity of the supply side of oxygen has been primarily described by
flow heterogeneity, the diffusional component of oxygen supply should not be
ignored, especially at high resolution (tissue regions << 1 g). Such oxygen
diffusion does not seem to take place from arterioles or venules within the
heart, but seems to occur between capillaries, in contrast to data recently
obtained from other tissues. Oxygen diffusion may even become the primary
determinant of oxygen supply during obstructed flow conditions. Studies aimed at
modelling regional blood flow and oxygen consumption have demonstrated marked
regional heterogeneity of oxygen consumption matched by flow heterogeneity
Direct, non-invasive indicators of the balance between oxygen supply and
consumption include NADH videofluorimetry (mitochondrial energy state) and
microvascular PO2 measurement by the Pd-porphyrin phosphorescence technique.
These indicators have shown a relatively homogeneous distribution during
physiological conditions supporting the notion of regional matching of oxygen
supply with oxygen consumption. NADH videofluorimetry, however, has demonstrated
large increases in functional heterogeneity of this ratio in compromised hearts
(ischemia, hypoxia, hypertrophy and endotoxemia) with specific areas, referred to
as microcirculatory weak units, predisposed to showing the first signs of
dysoxia. It has been suggested that these weak units show the largest relative
reduction in flow (independent of absolute flow levels) during compromising
conditions, with dysoxia initially developing at the venous end of the capillary.
PMID- 10690281
TI - Gene therapy in the cardiovascular system: an update.
AB - This update reviews the remarkable progression in several cardiovascular gene
transfer domains. The first chemical gene therapy protocols to stimulate
angiogenesis in ischemic myocardium are discussed and both the great expectations
as well as remaining hurdle are highlighted. In experimental models of restenosis
and heart failure gene therapy shows promising results. Important question
regarding vector-related limitations and suboptimal in vivo delivery systems will
require expeditious attention for gene therapy to become a more widely applicable
option in cardiovascular diseases.
PMID- 10690282
TI - Human SCN5A gene mutations alter cardiac sodium channel kinetics and are
associated with the Brugada syndrome.
AB - BACKGROUND: Primary dysrhythmias other than those associated with the long QT
syndrome, are increasingly recognized. One of these are represented by patients
with a history of resuscitation from cardiac arrest but without any structural
heart disease. These patients exhibit a distinct electrocardiographic (ECG)
pattern consisting of a persistent ST-segment elevation in the right precordial
leads often but not always accompanied by a right bundle branch block (Brugada
syndrome). This syndrome is associated with a high mortality rate and has been
shown to display familial occurrence. METHODS AND RESULTS: Pharmacological sodium
channel blockade elicits or worsens the electrocardiographic features associated
with this syndrome. Hence, a candidate gene approach directed towards SCN5A, the
gene encoding the alpha-subunit of the cardiac sodium channel, was followed in
six affected individuals. In two patients missense mutations were identified in
the coding region of the gene: R1512W in the DIII-DIV cytoplasmic linker and
A1924T in the C-terminal cytoplasmic domain. In two other patients mutations were
detected near intron/exon junctions. To assess the functional consequences of the
R1512W and A1924T mutations, wild-type and mutant sodium channel proteins were
expressed in Xenopus oocytes. Both missense mutations affected channel function,
most notably a 4-5 mV negative voltage shift of the steady-state activation and
inactivation curves in R1512W and a 9 mV negative voltage shift of the steady
state activation curve in A1924T, measured at 22 degrees C. Recovery from
inactivation was slightly prolonged for R1512W channels. The time dependent
kinetics of activation and inactivation at -20 mV were not significantly affected
by either mutation. CONCLUSIONS: Two SCN5A mutations associated with the Brugada
syndrome, significantly affect cardiac sodium channel characteristics. The
alterations seem to be associated with an increase in inward sodium current
during the action potential upstroke.
PMID- 10690283
TI - Effects of imidapril on NOS expression and myocardial remodelling in failing
heart of Dahl salt-sensitive hypertensive rats.
AB - OBJECTIVES: To elucidate the relationship between renin-angiotensin system and
nitric oxide in hypertensive heart failure, we evaluated the effects of long-term
treatment with imidapril, angiotensin-converting enzyme inhibitor, on endothelial
cell nitric oxide synthase (eNOS) and inducible NOS (iNOS) expression in the left
ventricle (LV) and its relation to myocardial remodelling in failing heart of
Dahl salt-sensitive hypertensive rats (DS) fed a high-salt diet. METHODS: In DS
rats fed an 8% NaCl diet after the age of 6 weeks, a stage of concentric left
ventricular hypertrophy at 11 weeks (DSLVH) was followed by a distinct stage of
fatal left ventricular failure with chamber dilatation at 18 weeks (DSCHF).
Imidapril (DSCHF-I, n = 7, 1 mg/kg/day, subdepressor dose) or vehicle (DSCHF-V, n
= 7) were given from DSLVH to DSCHF stage for 7 weeks, and age-matched (18 weeks)
Dahl salt-resistant rats fed the same diet were served as control group (DR-C, n
= 7). RESULTS: Markedly increased left ventricular end-diastolic diameter and
reduced fractional shortening in DSCHF-V was significantly ameliorated in DSCHF-I
using transthoracic echocardiography. The level of eNOS mRNA and protein in the
LV was significantly suppressed in DSCHF-V compared with DR-C, and significantly
increased in DSCHF-I compared with DR-C and DSCHF-V. The iNOS mRNA and protein
and the fibrosis factor expression of type I collagen mRNA were significantly
increased in DSCHF-V compared with DR-C, and significantly decreased in DSCHF-I
compared with DSCHF-V. DSCHF-V demonstrated a significant increase in wall-to
lumen ratio, perivascular fibrosis, and myocardial fibrosis. These changes in the
microvasculature were improved significantly by imidapril. CONCLUSIONS:
Subdepressor dose of imidapril may ameliorate the endothelial damage not only by
inhibiting production of angiotensin II but also by promoting eNOS and inhibiting
iNOS mRNA and protein expression in the LV, and this increased eNOS mRNA and
protein level may have a role in the improvement of congestive heart failure and
myocardial remodelling.
PMID- 10690284
TI - Hemodynamic effects of nitric oxide synthase inhibition at steady state and
following tumor necrosis factor-alpha-induced myodepression.
AB - OBJECTIVE: Nitric oxide (NO) has been proposed as a common mediator of tumor
necrosis factor-alpha (TNF alpha)-induced vasodilation and myocardial
dysfunction. Accordingly, we performed an extensive assessment of the influence
of NO synthase inhibition on left ventricle (LV) and circulatory performance in
conscious dogs at steady state and after establishment of TNF alpha mediated
myodepression. METHODS: Autonomically blocked, chronically instrumented dogs were
studied at steady state and 6 h after initiation of a 1-h rhTNF alpha infusion
(40 micrograms/kg). Ventricular performance was evaluated using the pressure
volume framework. Dogs were then treated with either NG-nitro-L-arginine
methylester (L-NAME, 40 mg/kg bolus) or angiotensin II (250-500 ng/kg). RESULTS:
L-NAME, under control conditions or following recombinant human (rh) TNF alpha
induced ventricular dysfunction, produced marked increases in afterload with
attendant increases in LV pressure, volume, and prolonged isovolumic relaxation
without adversely influencing coronary blood flow. regardless of whether the dogs
received rhTNF alpha, L-NAME did not affect the slopes of the end-systolic
pressure-volume and stroke-work (SW)-end-diastolic volume (EDV) relations (force
based measure of contractility), whereas the slope of the dP/dtmax-EDV relation,
a velocity dependent parameter of LV systolic function, declined. Overall
ventricular performance, as seen by the circulation, was reduced by L-NAME in
control as well as rhTNF alpha-treated dogs, evidenced by rightward shifts of the
SW-EDV and dP/dtmax-EDV relations. Similar findings were observed in the separate
cohorts of dogs, at steady state and 6 h after rhTNF alpha, following angiotensin
II at matched systolic pressure. CONCLUSIONS: Systemic NO synthase inhibition
with L-NAME does not acutely reverse rhTNF alpha-induced myocardial dysfunction.
The detrimental influence of L-NAME on LV size, relaxation, and velocity-based
measures of contractility is likely attributable to its effects on increasing
afterload.
PMID- 10690285
TI - Ischemic preconditioning attenuates ischemia/reperfusion-induced activation of
caspases and subsequent cleavage of poly(ADP-ribose) polymerase in rat hearts in
vivo.
AB - Recently, we have demonstrated that ischemic preconditioning (IP) both limits
infarct size and decreases internucleosomal DNA fragmentation in rat hearts in
vivo, and that there was a direct correlation between myocardial infarct size and
DNA fragmentation even after IP. In this study, we examined the ability of IP to
attenuate processing and activation of caspase-1 and caspase-3, and cleavage of
poly(ADP-ribose) polymerase (PARP), after prolonged ischemia and reperfusion
using the same in vivo animal model. Rats that underwent IP and controls (Ctrl)
were subjected to 30 min of left coronary artery occlusion followed by 180 min of
reperfusion. IP was accomplished by five 5-min cycles of ischemia, each followed
by 5 min of reperfusion. The amount of soluble nucleosomes was measured by enzyme
linked immunosorbent assay. Cleavage of caspases-1 and -3, and of one of their
substrates PARP, was analyzed by Western blotting. Nucleosomal DNA fragmentation
was significantly reduced in ischemic left ventricular (LV) tissue obtained from
IP compared with Ctrl animals. The proforms of caspases-1 and -3, and the active
form of PARP were not cleaved in the nonischemic LV region of both IP and Ctrl
hearts. In contrast, the proform of caspase-3 and the active form of PARP were
cleaved in the ischemic LV region of Ctrl hearts, while processing of caspase-1
was increased. Cleavages of caspases-1 and -3, and inactivation of PARP were
prevented by IP. The results of this study indicate that IP attenuates both
internucleosomal DNA fragmentation and caspases processing, and suggest that the
prevention of caspases activation by IP may be important steps in protecting the
heart against ischemia/reperfusion injury in vivo.
PMID- 10690286
TI - Chronic antisense therapy for angiotensinogen on cardiac hypertrophy in
spontaneously hypertensive rats.
AB - OBJECTIVE: We examined the effect of the suppression of plasma angiotensinogen
(AGT) by the intravenous injection of antisense oligodeoxynucleotides (ODNs)
against AGT targeted to the liver on cardiac remodeling in spontaneously
hypertensive rats (SHR). The ODNs against rat AGT were coupled to
asialoglycoprotein (ASOR) carrier molecules, which serve as an important method
for regulating liver gene expression. METHODS: Male SHR (n = 18), and age-matched
male Wistar-Kyoto rats (WKY, n = 6) were used for this study. At 10 weeks of age,
the SHR were divided into three groups (each group n = 6), and the systolic blood
pressure (SBP) did not significantly change among them. The control SHR and WKY
groups received saline, the sense SHR group was injected with the sense ODNs
complex and the antisense SHR group was injected with the antisense ODNs complex,
from 10 to 20 weeks of age. ASOR-poly(L)lysine-ODNs complex was injected via the
tail veins twice a week. RESULTS: At the end of the treatment, a reduction of
hepatic AGT mRNA, cardiac angiotensin II type 1 receptor mRNA and the plasma AGT
concentration was only observed in the antisense-injected SHR but not in the
other groups of SHR and WKY. This antisense therapy did not significantly change
the mRNA expression for angiotensin converting enzyme, angiotensin II type 2
receptor and AGT in the left ventricle (LV) among all three groups. Although the
plasma angiotensin II (Ang II) concentration significantly decreased to the level
of WKY after the antisense therapy, the SBP, LV to body weight ratio and %
collagen volume fraction also showed a reduction, however, these findings were
still larger than in the WKY than in either the sense-injected SHR or control
SHR. CONCLUSION: The plasma AGT is considered to play a role in the development
of cardiac hypertrophy in SHR, but it has not a complete effects on cardiac
remodeling even if the plasma Ang II levels are inhibited because of an
insufficient suppression of hypertension.
PMID- 10690287
TI - Passive ventricular constraint amends the course of heart failure: a study in an
ovine model of dilated cardiomyopathy.
AB - OBJECTIVE: Dilated cardiomyopathy (DCM) is associated with a progressive
deterioration in cardiac function. We hypothesised that some of the deleterious
effects of DCM could be reduced by mechanically limiting the degree of cardiac
dilatation. METHODS: A Transonic 20A cardiac output (CO) flow-probe was implanted
in the pulmonary artery of 12 adult (52 +/- 4 kg) sheep. Early heart failure was
created by rapid right ventricular (RV) pacing for 21 days at a rate which
resulted in an initial 10% decrease in CO (to a maximum of 190 bpm). A custom
polyester jacket (Acorn Cardiovascular, St Paul, MN) was then placed, via a
partial lower sternotomy, on the ventricular epicardium of all sheep. Animals
were randomised either to jacket retention (wrap) or removal (sham). Pacing was
recommenced at a higher rate (that initiated a further 10% decrease in CO) for 28
days. Haemodynamic and echocardiographic parameters were determined at baseline,
implant and at termination. RESULTS: At termination, the left ventricular
fractional shortening was significantly higher (p = 0.03), the degree of mitral
valve regurgitation lower (scaled 0-3) (p = 0.03) and the left ventricular long
axis area smaller (p = 0.02) in the wrap animals compared with sham. CONCLUSIONS:
In this model of heart failure, ventricular constraint with a polyester jacket
diminished the deterioration in cardiac function associated with progressive
dilated cardiomyopathy. These results suggest that maintainance of a more normal
cardiac size and shape may be beneficial in patients with dilated cardiomyopathy.
PMID- 10690288
TI - On the mechanism of the failure of mitochondrial function in isolated guinea-pig
myocytes subjected to a Ca2+ overload.
AB - OBJECTIVE: The influence of agents that inhibit the movement of Ca2+ across the
mitochondrial membrane or Ca2+ dependent changes to this membrane upon the
response of isolated ventricular myocytes to a Ca2+ overload has been
investigated. METHODS: The changes of intracellular Ca2+ and Mg2+ ([Ca2+]i,
[Mg2+]i) (as reflected by cellular ATP), mitochondrial membrane potential (psi m)
and NADH was measured upon the response of isolated ventricular myocytes to a
Ca2+ overload. RESULTS: A slow depolarization of psi m during Ca2+ depletion and
its prompt recovery on Ca2+ repletion were unaffected by ruthenium red,
clonazepam, CGP-37157 which is a high potent inhibitor of the mitochondrial
Na+/Ca2+ antiport or cyclosporin A but a large delayed sustained depolarization
was inhibited. The slow small fall in [Mg2+]i on Ca2+ depletion and a rapid
recovery on Ca2+ repletion were unaffected by ruthenium red, clonazepam, CGP
37157 or cyclosporin A. A delayed sustained larger rise in [Mg2+]i was inhibited.
The marked sustained fall in NADH autofluorescence that occurs on Ca2+ overload
was attenuated and transient in the presence of ruthenium red, CGP-37157 and
cyclosporin A. CONCLUSION: These results are consistent with an increase in Ca2+
cycling across the mitochondrial membrane provoked by the combined Na+ and Ca2+
overload of cardiac myocytes, causing a depolarization sufficient to uncouple
respiration and lead to the depletion of cellular ATP.
PMID- 10690289
TI - Norpropoxyphene-induced cardiotoxicity is associated with changes in ion
selectivity and gating of HERG currents.
AB - OBJECTIVE: Norpropoxyphene (NP) is a major metabolite of propoxyphene (P), a
relatively weak mu-opioid receptor agonist. Toxic blood concentrations ranging
from 3 to 180 mumol/l have been reported and the accumulation of NP in cardiac
tissue leads to naloxone-insensitive cardiotoxicity. Since several lines of
evidence suggest that not only block of INa but also IK block may contribute to
the non-opioid cardiotoxic effects of P and NP, we investigated the effects of P
and NP on HERG channels. HERG presumably encodes IKr, the rapidly-activating
delayed rectifier K+ current, which is known to have an important role in
initiating repolarization of action potentials in cardiac myocytes. METHODS:
Using the 2-microelectrode voltage clamp technique we investigated the
interaction of P and NP with HERG channels, expressed in Xenopus oocytes.
RESULTS: Our experiments show that low drug concentrations (5 mumol/l) facilitate
HERG currents, while higher drug concentrations block HERG currents (IC50-values
of approx. 40 mumol/l) and dramatically shift the reversal potential to a more
positive value because of a 30-fold increased Na(+)-permeability. P and NP also
alter gating of HERG channels by slowing down channel activation and accelerating
channel deactivation kinetics. The mutant S631C nullifies the effect of P and NP
on the channel's K(+)-selectivity. CONCLUSION: P and NP show a complex and unique
drug-channel interaction, which includes altering ion-selectivity and gating.
Site-directed mutagenesis suggests that an interaction with S631 contributes to
the drug-induced disruption of K(+)-selectivity. No specific role of the minK
subunit in the HERG block mechanism could be determined.
PMID- 10690290
TI - The angiotensin-converting enzyme inhibitor, fosinopril, and the angiotensin II
receptor antagonist, losartan, inhibit LDL oxidation and attenuate
atherosclerosis independent of lowering blood pressure in apolipoprotein E
deficient mice.
AB - OBJECTIVE: To investigate the possible mechanisms of the antiatherosclerotic
effects of the angiotensin-converting enzyme (ACE) inhibitor, fosinopril, in
apolipoprotein (apo) E deficient mice. METHODS: Apo E deficient (E0) mice at the
age of 8 weeks received either placebo or a high dose (25 mg/kg/d) of fosinopril
supplemented in their drinking water. RESULTS: After 12 weeks of treatment,
fosinopril reduced the aortic lesion size by 70%, compared with the placebo
group. At this dosage, fosinopril significantly reduced blood pressure from 93 +/
2 mmHg before treatment to 70 +/- 2 mmHg at the end of the treatment period (P <
0.005). Fosinopril also increased the resistance of the mice plasma low density
lipoprotein (LDL) to CuSO4-induced oxidation, as shown by a 90% reduction in the
LDL content of malondialdehyde (MDA) and also by a prolongation of the lag time
required for the initiation of LDL oxidation (from 100 min in the placebo-treated
mice to more than 240 min in the fosinopril-treated mice; P < 0.001). In
addition, fosinopril inhibited CuSO4-induced oxidation of LDL that was obtained
from the aortas of the treated mice, as shown by an 18% and 37% reduction in the
LDL content of lipid peroxides and hydroperoxy-cholesterol linoleate,
respectively, compared with the placebo-treated mice (P < 0.01). A low dosage of
fosinopril (5 mg/kg/d) that was still adequate to reduce their plasma ACE
activity and LDL propensity to lipid peroxidation was insufficient to lower their
blood pressure. This dosage also reduced the aortic lesion size in the apo E
deficient mice by 40% (P < 0.01). CONCLUSIONS: The antiatherogenic effects of
fosinopril in apo E deficient mice are due not only to blood pressure reduction
but also to the direct inhibition of angiotensin II-dependent effects, which are
probably also associated with the inhibition of LDL oxidation.
PMID- 10690291
TI - Peroxisome proliferator-activated receptor gamma C161-->T polymorphism and
coronary artery disease.
AB - BACKGROUND: Peroxisome proliferator-activated receptor gamma (PPAR gamma) as a
transcription factor plays an important role in lipid metabolism, glucose
homeostasis, insulin sensitivity, obesity, diabetes, foam cell formation and
atherogenesis. METHODS AND RESULTS: We have studied distribution of the PPAR
gamma C161-->T substitution at exon 6 in 647 Australian Caucasian patients aged <
or = 65 years (484 men and 163 women) recruited consecutively, with or without
angiographically documented coronary artery disease (CAD). The frequencies of the
CC, CT and TT genotypes were 69.8%, 27.7% and 2.5% and the 'T' allele frequency
0.163. They were in Hardy-Weinberg equilibrium and not different between men and
women. The BMI and waist to hip ratio (WHR) among patients with CC, CT + TT
genotypes were not different (P = 0.878, P = 0.677). However there was a
significant association between the polymorphism and CAD. The 'T' allele carriers
(CT + TT) had significantly reduced CAD risk compared to the CC homozygotes (odds
ratio: 0.457, 95% CI: 0.273-0.763, P = 0.0045) in a logistic regression model
after controlling other known risk factors. This reduced risk was particularly
evident among CT heterozygotes (odds ratio: 0.466, 95% CI: 0.291-0.746, P =
0.0015), who also had lower apo B and total cholesterol to HDL-C ratios (P <
0.05). CONCLUSION: We report that the PPAR gamma C161-->T substitution is
associated with a reduced CAD risk, particularly among CT heterozygous patients,
but not with obesity in Australian Caucasian patients. It implicates that the
PPAR gamma may have a significant role in atherogenesis, independent of obesity
and of lipid abnormalities, possibly via a direct local vascular wall effect.
PMID- 10690292
TI - Effects of brain natriuretic peptide on forearm vasculature: comparison with
atrial natriuretic peptide.
AB - OBJECTIVE: The aim of the present study was to determine the vasoactive effects
of brain natriuretic peptide (BNP) as compared to those of atrial natriuretic
peptide (ANP) in normal man. METHODS: Ten healthy male subjects (median age 21
(20-23) year) were studied twice. In the first study equimolar doses (1, 3, and
10 pmol/dl/min) of both BNP and ANP (in random order and double blind) were
infused into the brachial artery of the non-dominant arm with a 1-h wash-out
period in between. In the second study two BNP (n = 5) or ANP (n = 5) dose
response curves were performed in order to assess the repeatability of the
BNP/ANP infusions. To this end, BNP and ANP were infused in the same equimolar
doses as in the first protocol. Forearm blood flow (FBF) was determined by venous
occlusion plethysmography before and during infusions. RESULTS: BNP increased the
FBF ratio (infused/contralateral arm) by 6%, 17%, and 48%, respectively (p <
0.05), while ANP increased the FBF ratio by 4%, 58%, and 133% (p < 0.001). The
slopes of the BNP dose-response curves differed significantly from those of the
ANP curves (18.1 versus 43.2; p = 0.022). No differences were observed between
the repeated dose-response curves of either BNP or ANP. CONCLUSIONS: The present
data demonstrate that BNP induces a dose-dependent vasodilatation in man. On a
molar basis, however, this vasodilatation is significantly less than the
vasodilatation induced by ANP. These differences may be related to differences in
natriuretic-peptide-receptor affinity. Furthermore, our data show that the
vasoactive effects of both BNP and ANP are repeatable in time.
PMID- 10690293
TI - Enhanced coronary vasoconstriction to oxidative stress product, 8-epi
prostaglandinF2 alpha, in experimental hypercholesterolemia.
AB - OBJECTIVES: The F2-isoprostanes are a family of novel prostaglandin isomers and a
stable product of in vivo oxidative stress. 8-epi-prostaglandinF2 alpha, a member
of this isoprostane family, is a vasoconstrictor and its local release may
contribute to the abnormal vasomotor tone associated with hypercholesterolemia.
We therefore aimed to outline the role of 8-epi-prostaglandinF2 alpha as a
coronary vasoconstrictor in experimental hypercholesterolemia. METHODS AND
RESULTS: Pigs were randomized to two experimental groups (each n = 9): normal (N)
and high cholesterol (HC) diet. To determine the vasoconstrictive effects of 8
epi-prostaglandinF2 alpha in vitro, doses from 10(-9) to 10(-5) M were used to
constrict coronary epicardial rings. Plasma total and LDL cholesterol levels were
significantly higher in the HC group compared with the N group (P < 0.005) as
were plasma 8-epi-prostaglandinF2 alpha levels (P < 0.001). 8-epi-prostaglandinF2
alpha immunoreactivity was present in the vessel wall in both groups. Normal
vessels with intact endothelium (n = 8 rings) contracted to 8-epi-prostaglandinF2
alpha (maximal contraction 15.5 +/- 8.74%). In the HC group, rings with intact
endothelium had a greater contractile response to 8-epi-prostaglandinF2 alpha
compared to normals (72.3 +/- 7.9%; n = 8; P < 0.0001). This was reversed by
preincubation with NOR-3, a NO donor (maximal contraction 6.7 +/- 1.56%; n = 5; P
< 0.0001). Enhanced contraction in normal vessels occurred with endothelial
denudation (98.4 +/- 3.56%; n = 6; P < 0.0001) and with preincubation of the
endothelium-intact rings with L-NMMA (N-monomethyl-L-arginine), an NO synthase
inhibitor (85.5 +/- 10.3%, n = 6, P < 0.001). The enhanced contraction seen with
hypercholesterolemia did not occur with other prostanoid vasoconstrictors.
CONCLUSION: Experimental hypercholesterolemia leads to a significant increase in
8-epi-prostaglandinF2 alpha levels in addition to enhanced 8-epi-prostaglandinF2
alpha-induced coronary vasoconstriction, in vitro. These findings support a role
for the F2-isoprostanes in the regulation of coronary vasomotor tone in
pathophysiologic states.
PMID- 10690294
TI - Estrogen attenuates the adventitial contribution to neointima formation in
injured rat carotid arteries.
AB - OBJECTIVE: This study tested, in ovariectomized rats, whether (1) adventitial
activation plays a role in the vascular injury response, and (2) inhibition of
adventitial activation and the subsequent wave of cell proliferation moving from
adventitia to neointima contributes to the estrogen-induced attenuation of
neointima formation in balloon injured carotid arteries. METHODS: Ovariectomized
Sprague-Dawley rats were treated with either 17 beta-estradiol or vehicle
beginning 72 h prior to balloon injury of the right common carotid artery and
were sacrificed at 0, 3, 7, 14 and 28 days after injury. BrdU was administered 18
h and 12 h prior to sacrifice in order to quantitate mitotic activity in
adventitia, media and neointima of the damaged vessel at specified times post
injury. RESULTS: Adventitial activation, evidenced by positive BrdU staining, was
evident on the day of injury, peaked on day 3 and was resolved by day 7, thus
preceding neointima formation. Numbers of BrdU labeled cells in adventitia on day
3 were significantly reduced in estrogen treated rats compared to controls. BrdU
labeled cells were undetectable in media on the day of injury, appeared at day 3
and disappeared by day 14. Neointima appeared at day 7 and increased in area
throughout the period of observation. Neointimal area and numbers of BrdU labeled
cells in neointima were significantly reduced in estrogen treated rats compared
to controls. These findings suggest that there is a wave of cell proliferation
moving in an adventitia-to-lumen direction following endoluminal injury of the
rat carotid artery and that estrogen modulates this proliferative response to
injury. CONCLUSION: These results support the hypothesis that adventitial
activation contributes to the vascular injury response and that estrogen reduces
this contribution.
PMID- 10690295
TI - Chronic cardiac denervation affects the speed of coronary vascular regulation.
AB - OBJECTIVE: We tested the hypothesis that the rate of adaptation of coronary
metabolic vasodilatation and autoregulation is modulated by the cardiac nerves.
METHODS: Anaesthetised dogs (seven innervated (control) and seven with denervated
hearts) were subjected to controlled pressure perfusion of the left main coronary
artery. Heart rate was controlled by pacing. RESULTS: The steady state
autoregulation curves and metabolic regulation curves were similar in the two
groups. A sudden increase or decrease in heart rate was associated with a faster
response (22% shorter half-times) in the innervated than the denervated dogs (P <
0.001). A sudden increase or decrease in coronary arterial perfusion pressure was
associated with a slower response (24% longer half-times) in the innervated than
the denervated hearts (P < 0.005). CONCLUSIONS: We conclude that the speed of
response to metabolic and perfusion pressure changes is partly mediated by cardio
cardiac reflexes. Reflex coronary vasodilatation appears to reinforce the
metabolic vasodilatation of a heart rate increase and oppose the vasoconstriction
in response to increased perfusion pressure.
PMID- 10690296
TI - Involvement of myosin light-chain kinase in chloride-sensitive Ca2+ influx in
porcine aortic endothelial cells.
AB - OBJECTIVES: This study was designed to investigate the involvement of myosin
light-chain kinase (MLCK) in bradykinin- and thapsigargin-induced changes in
intracellular Cl- and Ca2+ concentrations ([Cl-]i; [Ca2+]i) in porcine aortic
endothelial cells. METHODS: Using the fluorescent probes N-ethoxycarbonylmethyl-6
methoxyquinolinium bromide (MQAE) and fura-2/AM, the effects of different MLCK
inhibitors on bradykinin- and thapsigargin-induced changes in [Cl-]i and [Ca2+]i
were assessed. RESULTS: Bradykinin and thapsigargin significantly decreased the
MQAE fluorescence intensity, which indicates increased [Cl-]i; these changes were
reversed by removal of extracellular chloride (Cl-o) and were significantly
inhibited by Cl(-)-channel inhibitor N-phenylanthranilic acid but not by Na(+)
K(+)-Cl- cotransport inhibitor furosemide. Pretreatment with ML-9 and wortmannin,
two different selective inhibitors of MLCK, significantly reduced these changes
in a dose-dependent manner. The inhibitory effects of ML-9 and wortmannin on the
Cl- responses were not significantly different and were not additive. Bradykinin
and thapsigargin provoked large increases in [Ca2+]i, which were significantly
diminished by removal of Cl-o and by pretreatment with the Cl(-)-channel
inhibitor N-phenylanthranilic acid. CONCLUSIONS: The study shows that an increase
in [Cl-]i may be involved in the Ca2+ influx in response to bradykinin and
thapsigargin and that MLCK might be involved in the Cl- response. We suggest that
MLCK might be involved in the Cl(-)-sensitive endothelial Ca2+ responses to
bradykinin and thapsigargin.
PMID- 10690297
TI - Wasting away. What a waste. Part 2.
PMID- 10690298
TI - The infarcted myocardium: simply dead tissue, or a lively target for therapeutic
interventions.
PMID- 10690299
TI - A plethora of mechanisms in the HERG-related long QT syndrome. Genetics meets
electrophysiology.
PMID- 10690300
TI - Rapid estimation of myocardial infarct size.
PMID- 10690301
TI - Rate control in atrial fibrillation: role of atrial inputs to the AV node.
PMID- 10690302
TI - Is there a local renin-angiotensin system in the heart?
AB - The existence of a local renin-angiotensin system in the heart is still a
controversial issue. This review discusses the evidence, obtained from studies in
cardiac cells, in isolated perfused hearts and in intact animals and humans, both
under normal and pathological conditions, for local production of prorenin,
renin, angiotensinogen, angiotensin-converting enzyme, angiotensin I and
angiotensin II at cardiac tissue sites. In addition, the role of alternative
angiotensin-generating enzymes (cathepsin, chymase) and the possibility of
(pro)renin uptake from the circulation is evaluated.
PMID- 10690303
TI - Actin-myosin interaction.
AB - Recent advances in the study of muscle physiology was made possible by the
application of novel experimental techniques including in vitro motility assay,
molecular biology, and X-ray crystallography. A similar approach was successfully
applied in studying the properties of cardiac actin-myosin interaction.
Implication in clinical cardiology is also reviewed.
PMID- 10690304
TI - Role of endothelial and smooth muscle cells in the physiopathology and treatment
management of pulmonary hypertension.
AB - Pulmonary hypertension can occur either as primary or secondary disease following
cardiac or pulmonary illnesses. In either cases, histological lung biopsies
reveal vascular remodelling i.e. smooth muscle cells proliferation with medial
hypertrophy, arteriolar muscularization and endothelial cell proliferation.
Subsequent intimal thickening, fibrosis and in situ thrombosis, altogether lead
to vaso-occlusive alterations referred to as plexiform lesions. Theories
concerning the detailed physiopathology of pulmonary hypertension have focused on
endothelial and smooth muscle cells' chemical factors production and response to
different mediators. The endothelium produces vasoconstrictor and growth
promoting factor such as endothelin-1 (ET-1) as well as vasodilator and growth
inhibitor factors like prostacyclin and nitric oxide (NO). ET-1 has been noted in
high concentrations in some clinical cases and experimental models of pulmonary
hypertension, coupled with ET-1 receptors' modulation and altered endothelin
converting enzyme activities, suggesting their active role in both arteriolar
vasoconstriction and occlusion. Vascular thrombosis which has been noted by
pathologists in pulmonary hypertension, could be related to an imbalance between
thrombotic inducing factors (such as anti-phospholipid antibodies, ET-1 and
thromboxane) and decreased fibrinolytic activity and antiaggregant endothelial
factors (like prostacyclin, NO, thrombomodulin). The discovery of an endothelial
cells' monoclonal proliferation in plexiform lesions of patients with primary
pulmonary hypertension may reinforce the cellular proliferation hypothesis to
understand the histopathology of this disease. In view of these new findings, the
treatments available for pulmonary hypertension have been expanded from the
previously employed oxygen therapy, calcium-channel blockers and anticoagulants,
to intravenous prostacyclin analogues (epoprostenol) and inhaled nitric oxide.
PMID- 10690305
TI - Voltage-shift of the current activation in HERG S4 mutation (R534C) in LQT2.
AB - OBJECTIVE: Recently, a novel missense mutation (R534C) in the S4 region of human
ether-a-go-go-related gene (HERG) was identified in one Japanese LQT2 family. The
S4 region presumably functions as a voltage sensor. However, it has not yet been
addressed whether the S4 region of HERG indeed functions as a voltage sensor, and
whether these residues play any role in abnormal channel function in cardiac
repolarization. METHODS: We characterized the electrophysiological properties of
the R534C mutation using the heterologous expression system in Xenopus oocytes.
Whole cell currents were recorded in oocytes injected with wild-type cRNA, R534C
cRNA, or a combination of both. RESULTS: Clinical features--QTc intervals of all
affected patients with R534C mutation in HERG are prolonged ranging from 460 to
680 ms (averaged QTc interval > 540 ms). One member of this family had
experienced sudden cardiac arrest, and other suffered from recurrent palpitation.
Electrophysiology--Oocytes injected with R534C cRNA did express functional
channels with altered channel gating. Kinetic analyses revealed that the R534C
mutation shifted the voltage-dependence of HERG channel activation to a negative
direction, accelerated activation and deactivation time course, and reduced
steady-state inactivation. Quantitative analyses revealed that this mutation did
not cause apparent dominant-negative suppression. Computer simulation-
Incorporating the kinetic alterations of R534C, however, did not reproduce
prolonged action potential duration (APD). CONCLUSIONS: The data revealed that
arginine at position 534 in the S4 region of HERG is indeed involved in voltage
dependence of channel activation as a voltage sensor. Our examination indicated
that HERG current suppression in R534C mutation was the least severe among other
mutations that have been electrophysiologically examined, while affected patients
did show significant QT prolongation. This suggest that another unidentified
factor(s) that prolong APD might be present.
PMID- 10690306
TI - Adenoviral-mediated gene transfer induces sustained pericardial VEGF expression
in dogs: effect on myocardial angiogenesis.
AB - OBJECTIVE: Angiogenic peptides like VEGF (vascular endothelial growth factor) and
bFGF (basic fibroblast growth factor) have entered clinical trials for coronary
artery disease. Attempts are being made to devise clinically relevant means of
delivery and to effect site-specific delivery of these peptides to the cardiac
tissue, in order to limit systemic side-effects. We characterized the response of
the pericardium to delivery of a replication-deficient adenovirus carrying the
cDNA for AdCMV.VEGF165, and assessed the effect of pericardial VEGF165 on
myocardial collateral development in a canine model of progressive coronary
occlusion. METHODS: Ameroid constrictors were placed on the proximal left
circumflex coronary artery of mongrel dogs. Ten days later, 6 x 10(9) pfu
AdCMV.VEGF165 (n = 9). AdRSV.beta-gal (n = 9), or saline (n = 7) were injected
through an indwelling pericardial catheter. Transfection efficiency was assessed
by X-gal staining. Pericardial and serum VEGF levels were measured serially by
ELISA. Maximal myocardial collateral perfusion was quantified with radiolabeled
or fluorescent microspheres 28 days after treatment. RESULTS: In AdRSV.beta-gal
treated dogs, there was extensive beta-gal staining in the pericardium and
epicardium, with minimal beta-gal staining in the mid-myocardium and endocardium.
Pericardial delivery of AdCMV.VEGF165 resulted in sustained (8-14 day)
pericardial transgene expression, with VEGF levels peaking 3 days after infection
(> 200 ng/ml) and decreasing thereafter. There was no detectable increase in
serum VEGF levels. Maximal collateral perfusion, a principal correlate of
collateral development and angiogenesis, was equivalent in all groups.
CONCLUSION: Adenoviral-mediated gene transfer is capable of inducing sustained
VEGF165 expression in the pericardium; however, locally targeted pericardial VEGF
delivery failed to improve myocardial collateral perfusion in this model.
PMID- 10690307
TI - Effects of chronic treatment by amiodarone on transmural heterogeneity of canine
ventricular repolarization in vivo: interactions with acute sotalol.
AB - OBJECTIVE: The present study was designed to examine the effects of chronic
amiodarone on the different ventricular cell subtypes in situ and to evaluate its
interactions with sotalol. METHODS: Three groups of dogs were studied. Group I (n
= 8) received no treatment. Group II (n = 7) and group III (n = 8) received,
respectively, 100 and 200 mg amiodarone orally twice a day for 6 weeks to 8
months. In vivo studies were performed under halothane anesthesia 14 h after the
last administration of amiodarone. Three leads ECG, femoral blood pressure and
left ventricular intramural monophasic action potentials (MAP) were continuously
recorded. Bradycardia was obtained by clamping the sinus node and beta-blockade
and the heart was driven by atrial pacing. Three weeks before the in vivo
experiments, the cellular electrophysiologic properties of right ventricular
tissues obtained by cardiac biopsy in six treated and six control dogs were
studied with standard microelectrodes. RESULTS: Amiodarone produced a dose
dependent decrease in plasma levels of triiodothyronine (T3; 5.9 +/- 0.4 pM in
control dogs, 3.1 +/- 0.2 pM in group III, P < 0.001) without affecting thyroxine
(T4). Under anesthesia, the QT interval was 14% larger in group III compared to
group I at a paced cycle length (PCL) of 1500 ms (P < 0.05). This is consistent
with the 10% increase in endocardial MAP duration in group III at the same PCL (P
< 0.05). There was no significant increase in transmural dispersion of MAP
duration. In group I, sotalol induced a significant reverse use-dependent
increase in MAP duration. This effect was reduced in group II and completely
suppressed in group III. Amiodarone prevented the sotalol-induced increase in
transmural dispersion of ventricular repolarization which was 69 +/- 12 ms in
untreated dogs, 41 +/- 8 ms in group II (P < 0.05) and 34 +/- 8 ms (P < 0.05) in
group III at PCL = 1500 ms. Amiodarone also prevented the sotalol-induced
ventricular tachyarrhythmias. In vitro, the action potential duration was longer
in amiodarone-treated dogs that in control ones (208 +/- 5 ms versus 188 +/- 9 ms
at PCL = 1000 ms, P < 0.05). The sotalol-induced prolongation of repolarization
was reduced in amiodarone-treated dogs. CONCLUSION: Chronic treatment of dogs
with amiodarone induced a moderate prolongation of the QT interval and MAP
duration without affecting transmural dispersion of repolarization and inhibited
the effects of acute sotalol, including the prolongation of repolarization, the
increase in transmural dispersion of repolarization and the induction of
arrhythmias.
PMID- 10690308
TI - Measurement of myocardial infarct size from plasma fatty acid-binding protein or
myoglobin, using individually estimated clearance rates.
AB - OBJECTIVE: In patients with acute myocardial infarction (AMI), estimation of
infarct size from the early markers, fatty acid-binding protein (FABP) and
myoglobin (MYO), usually assumes average (fixed) rate constants (FCR) for protein
clearance from plasma. However, individual variation in FCR is large. Renal
dysfunction causes slower clearance of FABP and MYO from plasma and, hence,
overestimation of infarct size in 20-25% of patients. We investigated whether or
not more accurate values of infarct size could be obtained with individually
estimated clearance rates. METHODS: Concentrations of FABP and MYO and, for
comparison, activities of the established cardiac markers, creatine kinase (CK)
and alpha-hydroxybutyrate dehydrogenase (HBDH), were assayed in serial plasma
samples from 138 patients with AMI. Individual FCR values of FABP and MYO were
estimated from plasma creatinine concentrations, sex and age. RESULTS: Individual
FCR values varied from 0.4 to 2.4 h-1. Use of these individual FCR values
significantly improved the correlation between infarct size, as estimated from
FABP or MYO on the one hand, and from CK and HBDH on the other. Approximately
equal estimates of infarct size were obtained for all four marker proteins.
CONCLUSIONS: Using individually estimated clearance rates, renal insufficiency no
longer hampers calculation of infarct size from FABP and MYO, and reliable
estimates of total myocardial damage can be obtained within 24 h after first
symptoms.
PMID- 10690309
TI - Nitric oxide controls cardiac substrate utilization in the conscious dog.
AB - OBJECTIVES: The aim of this study was to determine whether the acute inhibition
of nitric oxide (NO) synthase causes changes in cardiac substrate utilization
which can be reversed by a NO donor. METHODS: NO synthase was blocked by giving
30 mg/kg of nitro-L-arginine (NLA) i.v. to 15 chronically instrumented dogs.
Hemodynamics and blood samples from aorta and coronary sinus were taken at
control and at 1 and 2 h after NLA. In five dogs, 0.4 mg/kg of the NO donor 3754
was given i.v. 1 h after NLA. In six dogs, angiotensin II was infused over 2 h
(20-40 ng/kg/min) to mimic the hemodynamic effects of NLA. RESULTS: Two h after
NLA: mean arterial pressure was 153 +/- 4 mmHg; MVO2 increased by 38%; cardiac
uptake of lactate and glucose increased, respectively, from 20.0 +/- 5.0 to 41.0
+/- 9.3 mumol/min and from 1.1 +/- 0.7 to 6.8 +/- 1.5 mg/min (all P < 0.05 vs.
control). Cardiac uptake of free fatty acids decreased by 43% after 1 h (P <
0.05) and returned to control values at 2 h. Cardiac respiratory quotient
increased from 0.76 +/- 0.03 to 1.05 +/- 0.07, indicating a shift to carbohydrate
oxidation. All these changes were reversed by the NO donor. In the dogs receiving
angiotensin II infusion, MVO2 increased by 28% and lactate uptake doubled (both P
< 0.05), but no other metabolic changes where observed. CONCLUSIONS: The acute
inhibition of NO synthase by NLA causes a switch from fatty acids to lactate and
glucose utilization by the heart which can be reversed by a NO donor, suggesting
an important regulatory action of NO on cardiac metabolism.
PMID- 10690310
TI - Increased hypoxic stress decreases AMP hydrolysis in rabbit heart.
AB - OBJECTIVE: AMP conversion to adenosine by cytosolic 5'nucleotidase (5NT) or to
IMP by AMP deaminase determines the degree of nucleotide degradation, and thus
ATP resynthesis, during reoxygenation. To elucidate the regulation of AMP
hydrolysis during ischemia, data from 31P NMR spectroscopy and biochemical
analyses were integrated via a mathematical model. Since 5NT is downregulated
during severe underperfusion (5% flow), we tested 5NT regulation during less
severe underperfusion (10% flow) and then made the perfusate hypoxic to see if
the greater stress reactivated 5NT. METHODS: 31P NMR spectra and coronary venous
effluents were obtained from Langendorff-perfused rabbit hearts subjected to two
30-min periods of underperfusion (10% flow); the second period with or without
additional hypoxia (30% O2). Data were analyzed with a mathematical model
describing the kinetics of myocardial energetics and metabolism. RESULTS: A
single 30-min period of 10% flow causes downregulation of AMP hydrolysis and the
data from the second period of underperfusion are best described by lower 5NT
activity, even in the presence of extra hypoxia. Thirty percent less purines
appear in the venous effluent than predicted by the phosphoenergetics (PCr and
ATP) when IMP is not allowed to accumulate by the model, however the model
indicates that a constant accumulation of IMP via AMP deaminase could explain the
discrepancy between expected and measured purines in the venous effluent.
CONCLUSIONS: While AMP hydrolysis to adenosine is prominent in early ischemia and
acts to preserve cellular energy potential, during a second ischemic period,
nucleotides are conserved by the stable inhibition of AMP hydrolysis.
Furthermore, during 10% flow conditions, nucleotides are conserved, possibly via
an IMP-accumulatory pathway.
PMID- 10690311
TI - Role of the differential bombardment of atrial inputs to the atrioventricular
node as a factor influencing ventricular rate during high atrial rate.
AB - OBJECTIVES: The role of the atrial inputs for the conduction through the
atrioventricular node (AVN) at slow rates and during reentrant tachycardia is
well acknowledged, although still controversial. However, the relationship
between the sequence and rate of atrial engagement of the AVN inputs and the
resulting ventricular rate during high atrial rate remains unclear. This study
provides quantitative description of complex AVN input-output correlations
determining the ventricular rate during random high atrial rate. METHODS AND
RESULTS: 12 rabbit heart preparations were used to evaluate the ventricular rate
during programmed regular high atrial rate pacing or random pacing from eight
atrial sites. Electrograms were recorded at the posterior (P) and anterior (A)
AVN inputs, and at the bundle of His along with nodal cellular action potentials.
Lorenz-plots and input-output-rate correlations were used to quantify the
ventricular rate under different pacing protocols. Small alternations in the
sequence of activation of P and A resulted in substantial changes of the
organization of the intranodal cellular responses and the ventricular rate. The
ventricular rate was shown to be significantly dependent on the site of high rate
pacing (P < 0.01) and on the resulting mean rate of inputs activation.
Furthermore, the asymmetry between P- and A-bombardment was an important
determinant, so that high ventricular rate was associated with large difference
between the inputs rates and vice versa (P < 0.05). CONCLUSIONS: The prevailing
ventricular rate during high atrial rate is a complex dynamic parameter that
depends not only on the global mean atrial rate but, in a major part, on the
differential bombardment of the AVN inputs and on the site of initiation of the
atrial wave fronts.
PMID- 10690312
TI - Identification and properties of ATP-sensitive potassium channels in myocytes
from rabbit Purkinje fibres.
AB - OBJECTIVE: Our goal was to identify the ATP-sensitive potassium (KATP) channels
in cardiac Purkinje cells and to document the functional properties that might
distinguish them from KATP channels in other parts of the heart. METHODS: Single
Purkinje cells and ventricular myocytes were isolated from rabbit heart. Standard
patch-clamp techniques were used to record action potential waveforms. and whole
cell and single-channel currents. RESULTS: The KATP channel opener levcromakalim
(10 microM) caused marked shortening of the Purkinje cell action potential. Under
whole-cell voltage-clamp, levcromakalim induced an outward current, which was
blocked by glibenclamide (5 microM), in both Purkinje cells and ventricular
myocytes. Metabolic poisoning of Purkinje cells with NaCN and 2-deoxyglucose
caused a significant shortening of the action potential (control 376 +/- 51 ms; 6
min NaCN/2-deoxyglucose 153 +/- 21 ms). This effect was reversed with the
application of glibenclamide. Inside-out membrane patches from Purkinje cells
showed unitary current fluctuations which were inhibited by cytoplasmic ATP with
an IC50 of 119 microM and a Hill coefficient of 2.1. This reflects approximately
five-fold lower sensitivity to ATP inhibition than for KATP channels from
ventricular myocytes under the same conditions. The slope conductance of Purkinje
cell KATP channels, with symmetric, 140 mM K+, was 60.1 +/- 2.0 pS (mean +/-
SEM). Single-channel fluctuations showed mean open and closed times of 3.6 +/-
1.5 ms and 0.41 +/- 0.2 ms, respectively, at -60 mV and approximately 21 degrees
C. At positive potentials. KATP channels exhibited weak inward rectification that
was dependent on the concentration of internal Mg2+. Computer simulations, based
on the above results, predict significant shortening of the Purkinje cell action
potential via activation of KATP channels in the range 1-5 mM cytoplasmic ATP.
CONCLUSIONS: Purkinje cell KATP channels may represent a molecular isoform
distinct from that present in ventricular myocytes. The presence of KATP channels
in the Purkinje network suggests that they may have an important influence on
cardiac rhythm and conduction during periods of ischemia.
PMID- 10690313
TI - Connexin expression in cultured neonatal rat myocytes reflects the pattern of the
intact ventricle.
AB - OBJECTIVE: Primary cultures of neonatal rat ventricular myocytes have become a
widely used model to examine a variety of functional, physiological and
biochemical cardiac properties. In the adult rat, connexin43 (Cx43) is the major
gap junction protein present in the working myocardium. In situ hybridization
studies on developing rats, however, showed that Cx40 mRNA displays a dynamic and
heterogeneous pattern of expression in the ventricular myocardium around birth.
The present studies were performed to examine the expression pattern of the Cx40
protein in neonatal rat heart, and to examine the connexins present in cultures
of ventricular myocytes obtained from those hearts. METHODS: Cryosections were
made of hearts of 1-day-old Wistar rats. Cultures of ventricular myocytes
obtained from these hearts by enzymatic dissociation were seeded at various
densities (to obtain > 75, approximately 50%, and < 25% confluency) and cultured
for 24, 48 or 96 h. Cx40 and Cx43 were detected by immunofluorescence and
immunoblotting. RESULTS: Immunohistochemical stainings confirmed that gap
junctions in the atrium and His-Purkinje system were composed of at least Cx43
and Cx40. From the subendocardium towards the subepicardium Cx40 expression
gradually decreased, resulting in the sole expression of Cx43 in the
subepicardial part of the ventricular wall. In ventricular myocytes cultured at
high density (> 75% confluency) Cx43 and Cx40 immunoreactivity could be detected.
In contrast to Cx43 immunolabeling which showed a homogeneous distribution
pattern, Cx40 staining was heterogeneous, i.e. in some clusters of cells abundant
labeling was present whereas in others no Cx40 staining could be detected. The
pattern of Cx43 immunoreactivity was not altered by the culture density. In
contrast, in isolated ventricular myocytes cultured at low density (< 25%
confluency) the relative number of cell-cell interfaces that were Cx40
immunopositive decreased as compared to high density cultures (35 vs. 70%).
Western blots did not reveal significant differences in the level of Cx40 and
Cx43 expression at different culture densities. CONCLUSIONS: These results show
that cultured ventricular myocytes retained typical features of the native
neonatal rat ventricular myocardium with regard to their composition of gap
junctions. This implicates that these cultures may serve as a good model for
studying short-term and long-term regulation of cardiac gap junction channel
expression and function.
PMID- 10690314
TI - Use-dependent facilitation and depression of L-type Ca2+ current in guinea-pig
ventricular myocytes: modulation by Ca2+ and isoprenaline.
AB - OBJECTIVE: An increase in stimulation frequency can facilitate or depress cardiac
Ca2+ current (ICa). The aim was to examine the Ca2+ dependence of these effects,
to determine if facilitation is sustained, and to elucidate the mechanism by
which isoprenaline modulates facilitation. METHODS: We examined the effects of
increasing the stimulation frequency for 1 min, from 0.05 to 1 Hz, on ICa
recorded from guinea-pig ventricular myocytes, using the whole-cell, voltage
clamp technique. RESULTS: 1 Hz stimulation caused a facilitation of ICa that
peaked in 5 s and was followed by depression towards the basal level. Metabolic
inhibitors or replacement of extracellular Ca2+ with Ba2+ abolished facilitation
without affecting depression, implying that they are independent processes and
that facilitation required ATP and Ca2+. Subtraction of the depression observed
in either condition, from the response to 1 Hz stimulation recorded under control
conditions, revealed that ICa facilitation was well maintained during 1 Hz
stimulation. Increased intracellular Ca2+ buffering reduced both phases of the
response. Furthermore, varying the extracellular Ca2+ concentration ([Ca2+]o)
revealed a Ca(2+)-dependent enhancement of depression and a bell-shaped
dependence of facilitation on [Ca2+]o. Facilitation increased with [Ca2+]o up to
1 mM, then declined at higher concentrations due to partial masking by the
overlaping depression. Isoprenaline produced concentration-dependent inhibition
of facilitation and enhancement of depression when pipettes contained 2 mM EGTA,
but not BAPTA. For an equivalent increase in ICa amplitude, the effects of
isoprenaline and elevated [Ca2+]o on the response to 1 Hz stimulation were
quantitatively the same. CONCLUSIONS: Facilitation is sustained during increased
activity, but appears transient due to overlapping depression. Both responses are
promoted by increased submembrane [Ca2+]. Isoprenaline appears to modulate
facilitation and depression as a consequence of increased Ca2+ influx, rather
than cAMP-dependent phosphorylation. The apparent block of facilitation by
isoprenaline may result from masking by the enhanced depression.
PMID- 10690315
TI - Stimulation of L-type Ca2+ current in human atrial myocytes by insulin.
AB - OBJECTIVE: The L-type calcium current (ICa,L) in isolated human atrial myocytes
was investigated as a possible target of insulin in the regulation of cardiac
function. METHODS: Atrial myocytes were obtained from patients undergoing cardiac
surgery. Using the whole-cell configuration of the patch-clamp technique, we
investigated the stimulation of ICa,L by insulin in single human atrial myocytes.
RESULTS: We found a dose-dependent stimulation of ICa,L by insulin at
concentrations of 100 nM, 1 microM and 10 microM. Maximum stimulation of ICa,L
over basal ICa,L was 140 +/- 12% (n = 11) at 10 microM insulin. The maximum
conductance of ICa,L was increased by 10 microM insulin from 4.0 +/- 0.3 nS to
8.3 +/- 1.0 nS (n = 6). The stimulation of ICa,L by insulin was dose-dependent
and reversible. Isoproterenol (10 nM) that stimulates ICa,L by 271 +/- 48% (n =
10) over basal ICa,L acted faster than insulin. The half-maximum stimulation of
ICa,L by isoproterenol and insulin (10 microM) was reached after 31 +/- 2 s and
52 +/- 5 s, respectively. The insulin effect shown was totally reversed by
acetylcholine (3 microM) which is known to inhibit adenylyl cyclase activity/cAMP
production via Gi-proteins. Also, the selective insulin receptor tyrosine kinase
inhibitor (hydroxy-2-naphthanelyl-methyl)phosphonic acid completely inhibited the
insulin induced effect. CONCLUSION: Our data show that insulin stimulates the L
type calcium current in isolated human atrial myocytes in a dose-dependent and
reversible manner which appears to involve the insulin receptor tyrosine kinase.
Insulin regulation of ICa,L in human atrial myocytes may be an interesting system
for the analysis of the metabolic syndrome in man.
PMID- 10690316
TI - Role of Ca2+ availability to myofilaments and their sensitivity to Ca2+ in
myocyte contractile dysfunction in heart failure.
AB - OBJECTIVE: Contractile function is depressed at the isolated myocyte level in
heart failure (HF), which could result from the decreased availability of
intracellular calcium ([Ca2+]i) to the myofibrils and/or the depressed
sensitivity of myofilaments to [Ca2+]i. However, the cellular basis of
contractile dysfunction remains unestablished. METHODS: We isolated left
ventricular myocytes from dogs with rapid pacing-induced HF. Cell shortening and
[Ca2+]i transients were measured by indo-1 fluorescence and the myofilament Ca2+
sensitivity was analyzed by the shortening-[Ca2+]i relation in intact myocytes as
well as by the pCa tension relation in skinned cells. RESULTS: Peak cell
shortening magnitude was depressed in HF, associated with a parallel decrease of
[Ca2+]i transient amplitude. There was a significant positive correlation between
these two variables (r = 0.71, P < 0.01). In contrast, myofibrillar sensitivity
to Ca2+, determined by both intact and skinned myocytes, was comparable between
control and HF. Further, there was no significant difference in Ca2+ sensitivity
between control and HF even at shorter (1.8 microns) or longer (2.2 microns)
sarcomere length. CONCLUSIONS: Using both intact and skinned cellular
preparations, a potential defect in myocyte contractile function in HF was a
reduction in Ca2+ availability to the myofilaments, rather than the inherent
defects in myofilament sensitivity to Ca2+.
PMID- 10690317
TI - Vasoconstriction by in situ formed angiotensin II: role of ACE and chymase.
AB - OBJECTIVE: To assess the importance, for vasoconstriction, of in situ angiotensin
(Ang) II generation, as opposed to ang II delivery to AT receptors via the organ
bath fluid. METHODS: Ang I and II concentration-response curves in human and
porcine coronary arteries (HCAs, PCAs) were constructed in relation to estimates
of the clearances of Ang I and II (ClAngI, ClAngII) from the organ bath and the
release of newly formed Ang II (RAngII) into the bath fluid. HCAs were from 25
heart valve donors (age 5-54 years), and PCAs from 14 pigs (age 3 months).
RESULTS: Ang I- and II-evoked constrictions were inhibited by the AT1 receptor
antagonist, irbesartan, and were not influenced by the AT2 receptor antagonist,
PD123319. In HCAs Ang II was only three times more potent than Ang I, wheres, in
the experiments with Ang I, comparison of ClAngI with ClAngII and RAngII
indicated that most of the arterially produced Ang II did not reach the bath
fluid. Also in PCAs Ang I and II showed similar potency. In HCAs both the ACE
inhibitor, captopril, and the chymase inhibitor, chymostatin, inhibited Ang I
evoked vasoconstriction, while only chymostatin had a significant effect on
ClAngI. In PCAs Ang I-evoked vasoconstriction was almost completely ACE
dependent. CONCLUSIONS: This study points towards the functional importance of in
situ ACE- and chymase-dependent Ang II generation, as opposed to Ang II delivery
via the circulation. It also indicates that functionally relevant changes in
local Ang I-II conversion are not necessarily reflected by detectable changes in
circulating Ang II.
PMID- 10690318
TI - Maturation of the response to bradykinin in resistance and conduit pulmonary
arteries.
AB - OBJECTIVE: Immaturity of the endothelial-dependent relaxation is thought to be
characteristic of the newborn pulmonary elastic arteries. In adulthood, the
reactivity of different pulmonary arterial segments varies. Therefore, we
investigated the presence of endothelial heterogeneity in perinatal porcine
pulmonary arteries and compared it with the adult by studying the bradykinin-,
substance P- and acetylcholine-induced relaxations in different arteries.
METHODS: Three types of pulmonary arteries (large conduit elastic, distal
branching and resistance-sized; in situ diameters 0.7-1.7, 0.3-0.5 and 0.1-0.2
mm, respectively) were isolated from lungs of adult (nine months), young (60-84
h), newborn (4 min) and near-term foetal pigs. They were mounted for isometric
force recording, contracted first with K+ = 125 mmol/l (reference contraction).
Cumulative concentration-response curves to acetylcholine, substance P or
bradykinin were obtained from prostaglandin F2 alpha (30 mumol/l) precontracted
vessels. The effects of captopril and O2(95 or 8%) were also determined.
Experiments were terminated by adding 100 mumol/l papaverine, obtaining maximal
relaxation, which was used for normalising relaxations. RESULTS: (i)
Acetylcholine: In resistance arteries, relaxations were absent in the newborn and
the adult. In conduit arteries, they were present from 60-84 h onward. (ii)
Substance P: In resistance arteries, relaxations were only present in the adult.
In the other two types of arteries, rudimentary relaxations were present from the
mature foetal stage onward. (iii) Bradykinin: In resistance arteries, identical
relaxations were present at all ages which, in the foetus and the adult, were
insensitive to changes in O2 levels (95 to 8%). In conduit arteries,
concentration-dependent relaxations were present from birth, increasing in
amplitude with age and these were potentiated by captopril. Foetal conduit
arteries relaxed to the single application of 0.1 mumol/l bradykinin, indicating
age-dependent tachyphylaxis. CONCLUSIONS: (i) Bradykinin is unique among
endothelium-dependent vasodilators in being able to relax all vascular segments,
at all ages, subject to tachyphylaxis and bradykinin-breakdown but independent of
the prevailing O2 concentration. (ii) Heterogeneity of the relaxations between
conduit and resistance arteries is evident from the mature foetal stage onward.
(iii) The type of agonist, the type of vessel and the age each independently
determine the presence or absence of endothelial relaxations. Therefore, the
perinatal pulmonary circulation is not immature with respect to endothelial
dependent relaxation; rather, the nature of this process changes within the
perinatal period and between birth and adulthood.
PMID- 10690319
TI - A role for a glibenclamide-sensitive, relatively ATP-insensitive K+ current in
regulating membrane potential and current in rat aorta.
AB - OBJECTIVE: ATP-sensitive K+ channels have been classified based on their
inhibition by cytoplasmic ATP. Recent evidence in vascular smooth muscle has
suggested that these channels show weak sensitivity to intracellular ATP.
However, it is not known whether these channels regulate the resting K+
conductance in vascular smooth muscles. Therefore, the aim of the present
investigation was to characterize this current in rat aorta myocytes and to
examine whether it contributes to setting the membrane potential. METHODS: The
conventional and nystatin-permeablised whole cell patch clamp techniques were
used to characterize the effect of glibenclamide on membrane potential and K+
current in enzymatically dispersed rat aorta myocytes. RESULTS: The mean resting
potential measured in current clamp mode using the permeabilized patch approach
was -54 +/- 5 mV (n = 8). Glibenclamide (10 microM) caused a reversible 24-mV
depolarization in these cells. In symmetrical K+ (135 mM) solution an inward
glibenclamide-sensitive (10 microM) current (-4.1 +/- 0.7 pA/pF; n = 5),
hereafter termed Iglib, was observed at a membrane potential of -80 mV when cells
held at -60 mV were ramped from -80 to +80 mV. In the absence of any nucleotide
in the pipette solution, Iglib measured by the conventional whole-cell method was
-23.69 +/- 4.65 pA/pF (n = 9). With 1 and 3 mM ATP in the pipette, the average
current density was -25 +/- 6.3 pA/pF (n = 8), and -9.4 +/- 2.7 pA/pF (n = 9),
respectively. In the absence of ATP, 1 mM GDP significantly (P < 0.01) increased
Iglib (-44.8 +/- 8.4 pA/pF; n = 13). Inclusion of 1 mM ATP in the GDP-containing
pipette solution had no significant effect on the current amplitude (-56.4 +/-
10.7 pA/pF; n = 7). Iglib fell to -11.0 +/- 2.9 pA/pF (n = 10) if 1 mM GDP and 3
mM ATP were present. In symmetrical K+, the Iglib observed in the presence of 1
mM ATP in the pipette was increased by more than two-fold in the presence of 10
microM levcromakalim. In PSS containing 5 mM K+, a significant glibenclamide
sensitive current was observed at -45 mV membrane potential when cells dialyzed
with 1 mM ATP were ramped between -80 to 30 mV. CONCLUSION: These results
demonstrate that Iglib channels in rat aorta myocytes differ from classical KATP
channels, being relatively insensitive to intracellular ATP. Iglib therefore
appears to have an important role in contributing to the maintenance of the
resting potential in rat aortic smooth muscle.
PMID- 10690320
TI - Alterations in c-fos expression, cell proliferation and apoptosis in pressure
distended human saphenous vein.
AB - OBJECTIVES: Saphenous vein graft failures, resulting from thrombosis and the
abnormal proliferation, migration and apoptosis of vascular smooth muscle cells
(VSMC) are major limitations of coronary artery bypass surgery. We investigated
whether surgical trauma of human saphenous vein induces the early response gene c
fos and causes alterations in rates of proliferation and apoptosis. METHODS:
Surgically prepared human vein consisted of distended (at 350 mmHg for 2 min) or
non-distended segments of vein maintained in serum free RPMI at 37 degrees C and
5% CO2 for various time intervals. c-fos expression was detected by Northern
analysis. Cell proliferation and apoptosis were determined by [3H]thymidine
incorporation combined with proliferation cell nuclear antigen (PCNA)
immunostaining and TUNEL, respectively. Labelling indices for proliferation and
apoptosis were correlated with vessel was thicknesses. RESULTS: Control, freshly
isolated vein expressed no c-fos. Surgically prepared vein synthesized c-fos 1 h
following harvesting. There was a significant increase in c-fos in distended
compared to non-distended vein. c-Fos protein increased in surgically prepared
vein 24 h after harvesting. There was a significant increase in vascular cell
proliferation in the non-distended compared to the distended vein: mean (S.E.M.)
1279 (218) vs. 863 (155) dpm/microgram DNA, P < 0.05, n = 6. In addition, the
apoptotic index was significantly lower in the media of non-distended vs.
distended vein 0.82 (0.2) vs. 5.5 (1.5), P < 0.05, n = 5. CONCLUSIONS: These
findings demonstrate that surgical preparation of human saphenous vein increases
expression of c-fos mRNA and apoptosis and reduces proliferation when compared
with non-distended vein. These changes may influence the failure of saphenous
vein grafts.
PMID- 10690321
TI - Comment on "Interactions between endothelin-1 and the renin-angiotensin
aldosterone system".
PMID- 10690322
TI - NO in the cardiovascular system.
PMID- 10690323
TI - Molecular control of nitric oxide synthases in the cardiovascular system.
AB - Nitric oxide plays an important role in cardiovascular homeostasis. In this
review, the regulation of the three nitric oxide synthase isoforms in the
cardiovascular system are examined at molecular and cellular levels. In addition,
recent information gleaned from the use of NOS knockout mice are discussed.
PMID- 10690324
TI - Enzymatic function of nitric oxide synthases.
AB - Nitric oxide (NO) is synthesised from L-arginine by the enzyme NO synthase (NOS).
The complex reaction involves the transfer of electrons from NADPH, via the
flavins FAD and FMN in the carboxy-terminal reductase domain, to the haem in the
amino-terminal oxygenase domain, where the substrate L-arginine is oxidised to L
citrulline and NO. The haem is essential for dimerisation as well as NO
production. The pteridine tetrahydrobiopterin (BH4) is a key feature of NOS,
affecting dimerisation and electron transfer, although its full role in catalysis
remains to be determined. NOS can also catalyse superoxide anion production,
depending on substrate and cofactor availability. There are three main isoforms
of the enzyme, named neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial
NOS (eNOS), which differ in their dependence on Ca2+, as well as in their
expression and activities. These unique features give rise to the distinct
subcellular localisations and mechanistic features which are responsible for the
physiological and pathophysiological roles of each isoform.
PMID- 10690325
TI - Signal transduction of eNOS activation.
AB - Consistent with its classification as a Ca2+/calmodulin-dependent enzyme the
constitutive endothelial nitric oxide (NO) synthase (eNOS) can be activated by
receptor-dependent and -independent agonists as a consequence of an increase in
the intracellular concentration of free Ca2+ ([Ca2+]i) and the association of the
Ca2+/calmodulin complex with eNOS. Additional post-translational mechanisms
regulate the activity of eNOS, including the interaction of eNOS with caveolin-1,
heat shock protein 90 (Hsp90), or membrane phospholipids, as well as enzyme
translocation and phosphorylation. In response to fluid shear stress the
maintained production of NO by native and cultured endothelial cells is
associated with only a transient increase in [Ca2+]i. In the absence of
extracellular Ca2+ and in the presence of calmodulin antagonists, shear stress
stimulates a maintained production of NO which is insensitive to the removal of
extracellular Ca2+, but sensitive to tyrosine kinase inhibitors, Hsp90-binding
proteins and phosphatidylinositol 3-kinase inhibitors. A pharmacologically
identical activation of eNOS can be induced by protein tyrosine phosphatase
inhibitors suggesting that the phosphorylation of eNOS, and possibly that of an
associated regulatory protein(s), is crucial for its Ca(2+)-independent
activation.
PMID- 10690326
TI - Biological significance of endogenous methylarginines that inhibit nitric oxide
synthases.
AB - The guanidino-methylated arginine analogue NG monomethyl-L-arginine (L-NMMA) has
been the standard nitric oxide synthase inhibitor used to evaluate the role of
the L-arginine:nitric oxide pathway. However, L-NMMA and other methylated
arginine residues are also synthesised in vivo by the action of a family of
enzymes known as protein arginine methyltransferases. Proteolysis of proteins
containing methylated arginine residues releases free methylarginine residues
into the cytosol from where they may pass out of the cell into plasma. Of the
three known methylarginine residues produced in mammals only asymmetrically
methylated forms (L-NMMA and asymmetric dimethylarginine (ADMA)) but not
symmetrically methylated arginine (symmetric dimethylarginine (SDMA)) inhibit
nitric oxide synthase (NOS). We and others have proposed that endogenously
produced asymmetrically methylated arginines may modulate NO production and that
the accumulation of these residues in disease states may contribute to pathology.
The activity of the enzyme dimethylarginine dimethylaminohydrolase that
metabolises asymmetric methylarginines may be of critical importance in affecting
NO pathways in health or disease.
PMID- 10690327
TI - Interactions among ACE, kinins and NO.
PMID- 10690328
TI - Interactions between NO and reactive oxygen species: pathophysiological
importance in atherosclerosis, hypertension, diabetes and heart failure.
AB - There is a growing body of evidence suggesting that numerous pathological
conditions are associated with increased vascular production of reactive oxygen
species. This form of vascular oxidant stress and particularly interactions
between NO and oxygen-derived radicals represent a common pathological mechanism
present in many so-called risk factors for atherosclerosis. Furthermore, reactive
oxygen species seem to serve important cellular signalling mechanisms responsible
for many of the features of vascular lesion formation. The mechanisms whereby
vascular cells produce reactive oxygen species are only presently coming to
light, and almost certainly will prove to be a focus for future therapies.
PMID- 10690329
TI - Nitric oxide and coronary endothelial dysfunction in humans.
PMID- 10690330
TI - Nitric oxide and the proliferation of vascular smooth muscle cells.
PMID- 10690331
TI - NO and cardiac diastolic function.
PMID- 10690332
TI - Regulation of cardiac beta-adrenergic response by nitric oxide.
PMID- 10690333
TI - Nitric oxide, nitrates and ischaemic preconditioning.
PMID- 10690334
TI - Inhaled nitric oxide in cardiology practice.
AB - Inhaled nitric oxide allows selective pulmonary vasodilatation with rapidity of
action. It is effective in the acute post-operative management of pulmonary
hypertension in cardiac surgical patients and is also valuable in assessing the
pulmonary vasodilator capacity in patients with chronic pulmonary hypertension.
This review examines the current role of inhaled nitric oxide in cardiac
medicine, discussing issues concerning its administration and toxicity, as well
as a summary of clinical studies in cardiac patients. New roles, as a modifier of
platelet and leukocyte function, post-thrombolysis and following lung
transplantation are described. New agents and alternative therapies, which
prolong pulmonary activity, are also discussed.
PMID- 10690335
TI - Role of nitric oxide in the neural control of cardiovascular function.
AB - The discovery in 1990 that nitric oxide (NO) acts as a neuromodulator within the
central and peripheral nervous system triggered intensive research which
considerably extended our understanding how this factor regulates cardiovascular
functions. In addition to its direct effects on blood vessels NO has additional
targets at all levels of the neural control of circulation. When not scavenged by
hemoglobin, NO is relatively stable and diffuses over large distances (> 500
microns) so that one NO-producing cell can influence several thousands of
adjacent cells in vivo. In different brain regions, NO and its metabolites have
excitatory as well as inhibitory effects. The modulation of autonomic functions
by these factors is therefore highly complex and often variable between the
different levels from the brain to postganglionic nerve endings. This review is
focused on the available evidence derived from animal studies and will summarize
the current discussion about (i) the modulation of the generation of sympathetic
and parasympathetic activities within the brain stem by NO; (ii) the actions of
NO on cardiovascular reflexes and (iii) the role of NO as a modulator of
autonomic functions within the target organs. Finally, the available evidence
from human studies and some pathophysiological implications of altered NO
mediated modulation of the neural control of circulation will be discussed.
PMID- 10690336
TI - Inducible nitric oxide synthase and vascular injury.
AB - The role nitric oxide (NO) plays in the cardiovascular system is complex and
diverse. Even more controversial is the role that the inducible NO synthase
enzyme (iNOS) serves in mediating different aspects of cardiovascular
pathophysiology. Following arterial injury, NO has been shown to serve many
vasoprotective roles, including inhibition of platelet aggregation and adherence
to the site of injury, inhibition of leukocyte adherence, inhibition of vascular
smooth muscle cell (VSMC) proliferation and migration, and stimulation of
endothelial cell (EC) growth. These properties function together to preserve a
normal vascular environment following injury. In this review, we discuss what is
known about the involvement of iNOS in the vascular injury response.
Additionally, we discuss the beneficial role of iNOS gene transfer to the
vasculature in preventing the development of neointimal thickening. Lastly, the
pathophysiology of transplant vasculopathy is discussed as well as the role of
iNOS in this setting.
PMID- 10690337
TI - Nitric oxide and penile erection: is erectile dysfunction another manifestation
of vascular disease?
AB - There is convincing evidence that the prevalence of erectile dysfunction is
increased among men with ischaemic heart disease. This association may be
attributed to the fact that both erectile dysfunction and ischaemic heart disease
share similar risk factors (e.g. hypertension, dyslipidaemia, diabetes and
smoking). Nitric oxide (NO) activity is adversely affected, in penile and
vascular tissue, by these risk factors. It is therefore not surprising that a
defect in NO activity is thought to play a role in the pathogenesis of both
erectile dysfunction and ischaemic heart disease. We consider this evidence and
propose that defective NO activity provides a unifying explanation for the
association between these two conditions. Further research in this area may
improve our understanding of the pathogenesis of cardiovascular diseases as a
whole.
PMID- 10690338
TI - 17 Beta-estradiol stimulates expression of endothelial and inducible NO synthase
in rat myocardium in-vitro and in-vivo.
AB - OBJECTIVES: NO production has been attributed to play a major role in cardiac
diseases such as cardiac hypertrophy and cardiac remodeling after myocardial
infarction which display significant gender-based differences. Therefore we
assessed the effect of 17 beta-estradiol (E2) on estrogen receptor (ER) alpha and
beta and endothelial and inducible NO synthase in neonatal and adult rat
cardiomyocytes. METHODS: The presence of ER alpha and ER beta was demonstrated by
immunofluorescence and western blot analysis as well as the expression pattern of
inducible NO synthase (iNOS) and endothelial NOS (eNOS) in isolated
cardiomyocytes from neonatal and adult rats. Furthermore, regulation of
myocardial iNOS and eNOS expression by estrogen was evaluated in the myocardium
from ovariectomized or sham-operated adult Wistar-Kyoto rats. RESULTS: Incubation
with E2 led to translocalization of the ER into the nucleus and increased
receptor protein expression. E2 stimulated expression of iNOS and eNOS in both
neonatal and adult cardiac myocytes. Coincubation with the pure anti-estrogen ICI
182,780 inhibited upregulation of ER and NOS expression. In ovariectomized rats
myocardial iNOS and eNOS protein levels were significantly lower compared to sham
operated female animals. CONCLUSION: Taken together, these results show that E2
stimulates the expression of iNOS/eNOS in neonatal and adult cardiomyocytes in
vivo and in-vitro. These novel findings provide a potential mechanism of how
estrogen may modulate NOS expression and NO formation in the myocardium.
PMID- 10690339
TI - Nitric oxide synthase expression and role during cardiomyogenesis.
AB - OBJECTIVE: The aim of the present study was the investigation of the expression
of NOS during cardiomyogenesis and its functional role. DESIGN: The qualitative
and quantitative expression of NOS isoforms during different stages of cardiac
development was evaluated using immunocytochemistry and dot blots, respectively.
The functional relevance of NOS expression during cardiomyogenesis was
investigated using the in vitro ES cell-differentiation model and selective
pharmacological agents. RESULTS: On day 7.5 of embryonic development (E7.5) none
of the NOS isoforms were expressed in the embryo, whereas the inducible (iNOS),
as well as the endothelial (eNOS) isoforms were detected in the extraembryonic
parts. In contrast, starting from E9.5 rat and murine embryos displayed prominent
iNOS and eNOS expression. This was correlated with high expression of soluble
guanylylcyclase (sGC) as well as high cyclic GMP (cGMP) content. During further
development after E14.5 both, iNOS as well as eNOS, started to be downregulated
and shortly prior to birth reduced staining for eNOS was found, whereas iNOS was
hardly detectable. We further investigated whether NO plays a role for
cardiomyogenesis, using in vitro ES cell-derived cardiomyocytes differentiating
within embryoid bodies (EBs). The NOS expression pattern in these cells
paralleled the one detected in vivo. We demonstrate that continuous incubation of
EBs with the NOS inhibitors L-NMMA (2-10 mM) or L-NA (2-10 mM) for 4 to 9 days
after plating resulted in a pronounced differentiation arrest of cardiomyocytes,
whereas this effect could be reversed by coapplication of the NO-donor spermine
NONOate (10 microM). CONCLUSIONS: Both, iNOS and eNOS isoforms are prominently
expressed during early stages of cardiomyogenesis. Around E14.5 NOS expression
starts to decline. Moreover, the NO-generation is required for cardiomyogenesis
since NOS inhibitors prevent the maturation of terminally differentiated
cardiomyocytes using the ES cell system.
PMID- 10690340
TI - Repetitive myocardial stunning in pigs is associated with the increased
expression of inducible and constitutive nitric oxide synthases.
AB - OBJECTIVES: Nitric oxide (NO) has complex effects on myocardial function
particularly following ischaemia-reperfusion. The goal of this study was to
examine the result of repetitive myocardial stunning on myocardial NO release and
expression of inducible (iNOS) and constitutive (eNOS) NO synthases. METHODS AND
RESULTS: Propofol anaesthetised pigs underwent ten, 2-min episodes of circumflex
artery occlusion (n = 6) or acted as sham operated controls (n = 4). Measurements
of segment shortening demonstrated a fall in function in the ischaemic territory
to 52.5 +/- 7.3% (mean +/- S.E.M.) of baseline shortening 30 min after the
stunning stimulus, recovering to 92 +/- 8.7% 5.5 h later. Function remained
stable in sham controls. The change in venous-arterial [NO] between baseline and
6 h reperfusion was found to be significantly different between the two groups
(0.2 +/- 0.7 in stunned vs. -4.3 +/- 1.6 microM in shams; P < 0.02). Western
blotting and band optical density used to compare tissue from stunned territory
(S), non-stunned territory (IC) and sham control animals (SC) demonstrated this
was associated with an increase in the expression of both iNOS (S: 93 +/- 13.4,
IC: 37 +/- 2.4 and SC: 25 +/- 4 [arbitrary units], P < 0.01 and P = 0.031) and
eNOS (S: 104 +/- 7.4, IC; 62.5 +/- 7.4 and SC; 75.7 +/- 0.6, P < 0.03 and P <
0.01) in stunned myocardium. Immunocytochemistry localised iNOS reactivity to
vascular smooth muscle cells and cardiomyocytes in stunned tissue and eNOS
reactivity to endothelial cells. CONCLUSION: Recovery from repetitive myocardial
stunning is associated with the increased expression of both iNOS and eNOS and
would be compatible with a protective role for both these enzymes. This finding
has possible relevance for both the late window of ischaemic preconditioning and
myocardial hibernation.
PMID- 10690341
TI - Inducible nitric oxide synthase activation after ischemia/reperfusion contributes
to myocardial dysfunction and extent of infarct size in rabbits: evidence for a
late phase of nitric oxide-mediated reperfusion injury.
AB - BACKGROUND: Ischemia/reperfusion (I/R) leads to the induction of inducible nitric
oxide synthase. The present study investigated the effects of selective and
continuous inhibition of iNOS on myocardial performance, infarct size and
histomorphological changes after I/R in rabbits. METHODS AND RESULTS:
Ischemia/reperfusion (I/R) was induced by occlusion of the circumflex coronary
artery for 30 min followed by 48 h of reperfusion. Sham animals (group A) served
as control. Three groups were subjected to I/R: (B) placebo; (C) aminoguanidine
(AMG; 10 mg/kg bolus) given prior to and 48 h after I/R to test its acute
effects; (D) AMG (300 mg/kg/day s.c.) to test effects of continuous treatment.
Hemodynamics, myocardial blood flow, infarct size, iNOS activity, cGMP levels,
immunohistochemical analysis of iNOS expression and AMG tissue levels were
determined. Continuous AMG treatment improved myocardial performance
(hemodynamics and blood flow) compared to placebo group. iNOS was highest in
placebo-treated animals. AMG tissue levels were highest in tissues affected by
I/R. Infarct size (% of the circumflex region) was significantly smaller in group
D when compared to group B. CONCLUSIONS: This is the first study showing that
activation of myocardial iNOS isozyme during 48 h of reperfusion contributes to a
late phase of I/R-induced injury in rabbits. Selective and continuous modulation
of iNOS by AMG over this time period exerts protective effects with respect to
myocardial performance, coronary blood flow, cellular infiltration and reduction
of infarct size; this may be a novel therapeutic approach in the clinical
situation to limit irreversible myocardial injury associated with ischemia and
reperfusion.
PMID- 10690342
TI - Changes in extracellular pH mediate the chronotropic responses to L-arginine.
AB - We have recently shown that exogenous nitric oxide (NO) elicits a positive
chronotropic response by stimulating the hyperpolarization activated current,
I(f). OBJECTIVE: To examine whether L-arginine (L-Arg) can mimic the chronotropic
effect of NO by enhancing its endogenous production. METHODS: In spontaneously
beating guinea pig atria we evaluated the heart rate (HR) response to increasing
concentrations of L-Arg (1 mumol/l to 10 mmol/l), and compared it with that for D
Arg or L-lysine (L-Lys) (all in free base (FB) or hydrochloride (HCl)
formulation). RESULTS: L-ArgFB > 100 mumol/l caused a reversible dose-dependent
increase in HR (peak effect +64 +/- 7 bpm at 10 mmol/l, P < 0.05, n = 8).
However, a similar HR response occurred with D-ArgFB (n = 7) or L-LysFB (n = 6).
All FB formulations increased the perfusate pH (peak [pH]o = 8.61 +/- 0.03).
Although alkalinization can stimulate NO release from the endothelium, this is
unlikely to have contributed to HR changes in our preparation, since neither NG
methyl-L-arginine, (100-500 mumol/l, which per se reduced HR by 8 +/- 1%, P <
0.05, n = 9) nor NO scavenging (fresh 5% red blood cells, n = 9) caused a
rightward shift of the concentration-response curve to L-ArgFB. Furthermore, as
opposed to FB formulations, L-ArgHCl, D-ArgHCl or L-LysHCl > 1 mmol/l
significantly decreased HR and [pH]o (n = 17). The chronotropic effects of L-ArFB
or L-ArgHCl were reproduced by changing [pH]o with NaOH (n = 8) or HCl (n = 7),
whereas the HR increase with L-ArgFB was prevented by clamping [pH]o at 7.42 +/-
0.07 (n = 10). CONCLUSIONS: In vitro, L-Arg can markedly affect HR through a pH
mediated, NO-independent mechanism. Our data show that the opposing changes in
[pH]o induced by different formulations of L-Arg can importantly confound the
assessment of the biological effects of this amino acid.
PMID- 10690343
TI - Metabolic vasodilation in the human forearm is preserved in hypercholesterolemia
despite impairment of endothelium-dependent and independent vasodilation.
AB - OBJECTIVE: Hypercholesterolemia has been shown to impair endothelium-mediated,
nitric oxide (NO)-dependent responses to acetylcholine (ACh), serotonin,
substance P and flow-mediated dilation. We have recently shown that NO
contributes to metabolic vasodilation in the human forearm. We sought to
determine whether metabolic vasodilation is impaired in healthy subjects with
hypercholesterolemia. METHODS: We compared the forearm blood flow (FBF) responses
to isotonic exercise, ACh and the endothelium-independent vasodilator sodium
nitroprusside in young, otherwise healthy volunteers with hypercholesterolemia
and controls before and after the NO inhibitor NG-monomethyl-L-arginine (L-NMMA).
FBF was measured using venous occlusion plethysmography. Hypercholesterolemic (n
= 20) and control (n = 20) subjects were age- and gender-matched. RESULTS: Total
cholesterol (6.9 +/- 0.3 vs. 4.6 +/- 0.1 mmol/l, P < 0.0001), low density
lipoprotein (4.9 +/- 0.4 vs. 2.7 +/- 0.1 mmol/l, P < 0.001) and triglyceride (1.3
+/- 0.2 vs. 0.8 +/- 0.1 mmol/l, P = 0.005) levels were higher in the
hypercholesterolemic group. Basal FBF and resistance were similar in the two
groups. Hypercholesterolemia impaired the peak FBF response to ACh (11.1 +/- 1.9
vs. 17.6 +/- 2.2 ml/100 ml/min, P = 0.03), and reduced the peak response to
sodium nitroprusside (6.0 +/- 0.4 vs. 8.1 +/- 0.6 ml/100 ml/min, P < 0.01).
However, hypercholesterolemia did not affect peak hyperemic FBF (13.1 +/- 1.0 vs.
13.2 +/- 1.0 ml/100 ml/min, P = 1.0) or the FBF volume repayment during the 1 or
5 min after exercise. Resting FBF was reduced by L-NMMA to a similar degree (by
33% vs. 40%, P = 0.17) in both groups. Although L-NMMA reduced peak hyperemic FBF
(by 16% vs. 17%, P = 0.93) and the volume repaid after exercise in both groups,
there were no differences between the two groups. CONCLUSIONS: Exercise-induced
metabolic vasodilation is in part dependent on NO release. Hypercholesterolemia
impairs NO-mediated vasodilation, but is not associated with a reduction in
exercise-induced hyperemia. This may indicate that multiple compensatory
mechanisms are operative in skeletal muscle metabolic vasodilation.
PMID- 10690344
TI - L-arginine and L-NAME have no effects on the reendothelialization process after
arterial balloon injury.
AB - OBJECTIVE: Growth regulatory properties of nitric oxide (NO) in cultured
endothelial cells is controversial. The aim of our study was to investigate the
effect of L-arginine, the endogenous NO precursor, and L-NAME, an inhibitor of NO
synthase on the reendothelialization process after angioplasty. METHODS: Fifty
five New Zealand White rabbits underwent denudation of the left iliac artery.
After injury the rabbits were randomized in three groups: L-arginine 2.25% (L
arginine, n = 19); NG-nitro-L-arginine methyl ester 15 mg/kg/day (L-NAME, n =
19); and placebo (controls, n = 17). Treatment was solubilized in drinking water.
Reendothelialization was evaluated at 4 weeks by macroscopic evaluation of Evans
blue staining and endothelial-specific immunostaining (CD-31) on cross sections.
Intimal hyperplasia was evaluated by morphometric analysis. RESULTS: Despite a
significant increase in plasma arginine (P = 0.001) and a reduction in intimal
hyperplasia (P = 0.003) with L-arginine, neither agent had a significant effect
on reendothelialization at 4 weeks (controls = 36 +/- 4%, L-arginine = 43 +/- 3%,
L-NAME = 33 +/- 4%; NS). CONCLUSION: These results suggest that, in spite of
previously demonstrated effects on neointimal hyperplasia, the NO pathway does
not influence the regrowth of macrovascular endothelial cells in vivo.
PMID- 10690345
TI - Sympathectomy potentiates the vasoconstrictor response to nitric oxide synthase
inhibition in humans.
AB - OBJECTIVE: Nitric oxide exerts its cardiovascular actions at least in part by
modulation of the sympathetic vasoconstrictor tone. There is increasing evidence
that nitric oxide inhibits central neural sympathetic outflow, and preliminary
evidence suggests that it may also modulate peripheral sympathetic
vasoconstrictor tone. METHODS: To test this latter concept, in six subjects
having undergone thoracic sympathectomy for hyperhydrosis, we compared the
vascular responses to systemic L-NMMA infusion (1 mg/kg/min over 10 min) in the
innervated and the denervated limb. We also studied vascular responses to the
infusion of the non-nitric-oxide-dependent vasoconstrictor phenylephrine.
RESULTS: L-NMMA infusion evoked a roughly 3-fold larger increase in vascular
resistance in the denervated forearm than in the innervated calf. In the
denervated forearm, vascular resistance increased by 58 +/- 10 percent (mean +/-
SE), whereas in the innervated calf it increased only by 21 +/- 6 percent (P <
0.01, forearm vs. calf). This augmented vasoconstrictor response was specific for
L-NMMA, and not related to augmented non-specific vasoconstrictor responsiveness
secondary to sympathectomy, because phenylephrine infusion increased vascular
resistance similarly in the denervated forearm and the innervated calf (by 24 +/-
7, and 29 +/- 8 percent, respectively). The augmented vasoconstrictor response
was related specifically to denervation, because in control subjects, the
vasoconstrictor responses to L-NMMA were comparable in the forearm and the calf.
CONCLUSIONS: These findings indicate that in the absence of sympathetic
innervation, the vasoconstrictor responses to nitric oxide synthase inhibition
are augmented.
PMID- 10690346
TI - Inducible nitric oxide synthase colocalizes with signs of lipid
oxidation/peroxidation in human atherosclerotic plaques.
AB - OBJECTIVE: Advanced human atherosclerotic plaques are characterized by the
abundant presence of the autofluorescent non-soluble lipid pigment ceroid,
consisting of oxidized lipoproteins. The aim of the present study was to examine
the topographical and cellular distribution of inducible nitric oxide synthase
(iNOS or NOS II) within different stages of atherosclerosis and its
colocalization with ceroid deposits and nitrotyrosine. METHODS AND RESULTS:
Different stages of atherosclerosis were studied by immunohistochemistry on whole
mount longitudinal sections of carotid endarterectomy specimens. In the adaptive
intimal thickening the predominant cell type were smooth muscle cells. The fatty
streaks contained both smooth muscle cells and macrophages with an extremely low
NOS II immunoreactivity. The advanced atherosclerotic plaques however, showed a
very dense infiltration by macrophages, of which a subpopulation expressed NOS II
as a vesicular immunoreactivity in their cytoplasm. These were mainly present
around the necrotic core, in association with ceroid accumulation and
nitrotyrosine. Fluorescence quenching microscopy showed the presence of NOS II on
autofluorescent ceroid vesicles in the macrophages. Large extracellular ceroid
granules were not NOS II immunoreactive. NOS II mRNA was detected by RT-PCR and
the protein by Western blot in the plaque tissue but not in mammary arteries used
as controls. CONCLUSION: Ceroid, nitrotyrosine and NOS II colocalized in late
stages of atherosclerosis and were found around the necrotic core in the plaque.
This could suggest that NOS II expression in macrophages is involved in oxidation
and peroxidation of lipids, leading to ceroid formation.
PMID- 10690347
TI - Effects of endothelin receptor antagonists and nitric oxide on myogenic tone and
alpha-adrenergic-dependent contractions of rabbit resistance arteries.
AB - Regulation of vascular contractions by endothelium-derived endothelin-1 (ET-1)
and nitric oxide (NO) may vary depending on the stimulus. OBJECTIVES: To
investigate if ET-1 receptor stimulation and NO contributed to a similar extent
to the regulation of pressure- and alpha-adrenergic receptor (AR) agonist-induced
smooth muscle contraction. METHODS: Rabbit mesenteric arteries (150-200 microns)
were isolated, cannulated and pressurized. Changes in diameter were recorded as a
function of the perfusion pressure (PP) or alpha-AR agonist addition at a PP of
60 mmHg. All experiments were performed in the presence of indomethacin (10 mumol
1(-1)). RESULTS: At a PP of 60 mmHg, myogenic tone (MT) developed to represent 17
+/- 1% of the minimal diameter. The magnitude of the MT was increased by 140% (P
< 0.05) by the inhibition of NO production with N omega-nitro-L-arginine (L
NOARG). Bosentan, an ETA/B receptor antagonist, and BQ 123, a selective ETA
receptor antagonist, decreased (P < 0.05) MT either alone or in combination with
L-NOARG by approximately 30%. Phenylephrine (Phe), an alpha 1-AR agonist, induced
contraction; the sensitivity to Phe (pD2, 6.2 +/- 0.2) was unaffected by bosentan
or BQ 123 alone but increased (P < 0.05) by L-NOARG (pD2, 7.3 +/- 0.5). Further
addition of bosentan or BQ 123 restored the sensitivity to Phe to its control
value. Oxymetazoline (OXY), an alpha 2-AR agonist, induced contraction; the
sensitivity to OXY (pD = 2, 7.7 +/- 0.2) was unaffected by L-NOARG, bosentan or
BQ 123. CONCLUSION: Our results indicate that pressure-induced tone is
independently regulated by endothelium-derived NO and ET-1. In contrast, alpha 1
AR stimulation-induced tone is sensitive to ET-1 in the absence of NO, whereas
occupation of alpha 2-AR mediates a contraction unregulated by the endothelium.
PMID- 10690348
TI - NOS inhibition potentiates norepinephrine but not sympathetic nerve-mediated co
transmission in resistance arteries.
AB - OBJECTIVE: The in vitro interaction between sympathetic nerves and basal nitric
oxide release was studied in a resistance artery, since these interact powerfully
in large vessels. METHODS: The pharmacological interaction between L-NAME and
vasoconstriction to field stimulation of sympathetic nerves or exogenous
norepinephrine was studied in rabbit cutaneous resistance arteries in wire
myographs. RESULTS: Relaxation of norepinephrine-induced tone by acetylcholine,
but not sodium nitroprusside, was blocked by N omega-nitro-L-arginine methyl
ester (L-NAME: 100 microM), indicating that the agonist-induced release of nitric
oxide could oppose the vasoconstrictor effect of norepinephrine and confirming
that L-NAME had no effect on endothelium-independent vasodilatation. L-NAME
increased norepinephrine potency indicating basal NO release. With short bursts
of electrical field stimulation purinergic transmission was dominant at low
frequencies and adrenergic at high frequencies. L-NAME had no effect on nerve
mediated responses, even after blocking the purinergic component with alpha,beta
methylene ATP (3 microM), suggesting that the influence of spontaneously released
nitric oxide does not extend to the vascular smooth muscle cells under adrenergic
nervous control. CONCLUSION(S): This resistance artery exhibits a highly
effective nitric oxide-mediated vasodilatation to acetylcholine. It has basal
release of nitric oxide which antagonises exogenous norepinephrine. However,
basal nitric oxide did not influence adrenergic nerve transmission, which
contrasts with previous studies of larger arteries and veins. We speculate that
in small resistance arteries there may be a spatial limitation to the zones of
vascular smooth muscle influenced by the adrenergic nerves and by basal nitric
oxide from the endothelium, respectively. The role of endogenous nitric oxide in
modulating vascular tone may thus be less in resistance arteries than in
conducting arteries or capacitance vessels and purinergic transmission appears to
be particularly resistant.
PMID- 10690349
TI - Nitroglycerin-mediated vasorelaxation is modulated by endothelial calcium
activated potassium channels.
AB - OBJECTIVE: Recent in vitro data suggest, large conductance calcium-activated K+
channels (BKCa) modulate the vascular response to nitric oxide (NO). The in vivo
implications and the characteristics of this interaction are not clear. This
study firstly investigates whether modulation of BKCa affects the vascular
response to nitroglycerin (NTG)-derived NO in vivo and in the isolated heart and
secondly examines the influence of endothelial BKCa on NTG-mediated vasodilation
in vitro. METHODS: The hypotensive effect of NTG was measured in conscious,
chronically catheterized rats during i.v. infusions of iberiotoxin (IbTX, a
selective inhibitor of BKCa) or placebo. Similarly, NTG-induced flow-changes in
the isolated perfused rat heart were examined before and after IbTX treatment
(0.1 microM). Concentration-relaxation curves to NTG in the presence of various
K+ channel modulating agents were performed in vitro on porcine coronary arteries
with and without intact endothelium. RESULTS: I.v. infusion of IbTX reduced the
in vivo hypotensive effect of NTG by 55% (before IbTX: 32.0 +/- 3.0 mmHg, vs.
after IbTX: 14.5 +/- 3.2 mmHg, P < 0.05) and nearly abolished NTG-induced
increase in coronary flow in the isolated perfused heart (P < 0.05). In vitro,
this effect depended on an intact endothelium (endothelium intact segments; NTG:
pD2 = 5.8 +/- 0.1, Emax = 97.6 +/- 3.2% vs. NTG + IbTX: pD2 = 4.9 +/- 0.2, Emax =
49.7 +/- 6.2%, P < 0.05; endothelium denuded segments; NTG: pD2 = 6.9 +/- 0.1,
Emax = 104.0 +/- 1.4% vs. NTG + IbTX: pD2 = 6.7 +/- 0.1, Emax = 100 +/- 1.2%, P >
0.05). CONCLUSION: The results suggest, that modulation of endothelial BKCa
significantly affects NTG-induced vasorelaxation in vitro, in the isolated
perfused heart and in vivo.
PMID- 10690350
TI - Role of basal nitric oxide synthesis in vasoconstrictor hyporeactivity in the
perfused rat hindlimb after myocardial infarction: effect of captopril.
AB - OBJECTIVES: The contribution of vascular changes to the development of heart
failure is largely unknown. In the present study, we evaluated endothelial and
vascular contractile function in the rat hindlimb vascular bed after myocardial
infarction (MI), including the modulatory role of basal nitric oxide (NO)
production and the effects of treatment with the angiotensin converting enzyme
inhibitor captopril on vascular function. METHODS: MI was induced in male Wistar
rats by ligation of the left coronary artery. Acetylcholine-induced dilatations
were assessed in the ex vivo perfused hindlimb at various time points. At 2 and 5
weeks post-MI, vascular contractile function in the perfused hindlimb was
assessed from resistance changes induced by 35 mM and 125 mM potassium (K+) and
the maximum increase in resistance (delta Rmax, 125 mM K+ and 3 mg
phenylephrine). Basal NO synthesis was blocked for 2 weeks with L-nitro-arginine
methylester (L-NAME) in sham and MI rats and similar contractility experiments
were performed. The effect of captopril treatment from 2 to 5 weeks post-MI on
vasoconstrictor responses was also tested. RESULTS: Acetylcholine-induced
dilatations in the presence of 10 microM indomethacin were not different between
sham and MI rats. Vasoconstrictor responses to K+ and delta Rmax were reduced at
2 weeks after MI. This reduction in vasoconstrictor ability was similar to that
seen in L-NAME-treated sham rats, while chronic L-NAME treatment did not affect
vasoconstrictor reactivity in MI rats. Similarly, L-NAME induced an increase in
mean arterial pressure in sham rats, but not in MI rats. At 5 weeks after MI,
vasoconstriction to 125 mM K+ and delta Rmax were still reduced in MI rats; this
response was however partially restored after captopril treatment. CONCLUSION:
The development of vascular contractile hyporeactivity in the rat hindlimb after
MI may be due to reduced basal NO production. Delayed treatment with captopril
improves peripheral vascular contractile function in this setting.
PMID- 10690351
TI - Estrogen receptor-alpha gene transfer into bovine aortic endothelial cells
induces eNOS gene expression and inhibits cell migration.
AB - OBJECTIVES: It has been suggested that estrogen may improve endothelial cell
function to delay the onset of atherosclerosis in pre-menopausal females, though
its mechanism of action is not fully understood. We examined the hypothesis that
human estrogen receptor-alpha (ER alpha) gene transfection improves the
endothelial cell function. METHODS: A replication deficient adenoviral vector was
used to transfect the ER alpha gene into bovine aortic endothelial cells (BAEC)
and a GFP gene containing vector was used as control. Expression of the eNOS gene
was determined by Northern blot analysis and enzyme activity assay; cell
migration was assayed using a Transwell apparatus; and tyrosine phosphorylation
of FAK was estimated by Western blot analysis. RESULTS: ER alpha gene
transfection of endothelial cells produced a 2-3-fold increase in eNOS mRNA and
protein levels as well as a significant increase (P < 0.05) in NOS activity as
measured by citrulline assay and nitrite accumulation in the media in response to
bradykinin stimulation. Treatment of cells with estrogen blocking agent ICI
182780 inhibited eNOS induction in response to ER alpha transfection. ER alpha
gene transfection significantly inhibited (P < 0.05) bFGF-induced chemotactic
migration of endothelial cells but increased cell attachment to fibronectin,
laminin, and type I and IV collagens. ER alpha gene transfer also inhibited bFGF
stimulated tyrosine phosphorylation of FAK. CONCLUSION: Our results suggest that
the atheroprotective effects of estrogen may in part be mediated by ER alpha
induced upregulation of eNOS gene expression and maintenance of endothelial cell
function and integrity.
PMID- 10690352
TI - Gene transfer of endothelial nitric oxide synthase improves nitric oxide
dependent endothelial function in a hypertensive rat model.
AB - OBJECTIVE: We have shown previously that there is a relative nitric oxide
deficiency at the level of vascular endothelium in the stroke-prone spontaneously
hypertensive rat (SHRSP), a model of human essential hypertension, as compared to
its normotensive reference strain Wistar Kyoto (WKY) rat. The aim of the current
study was to investigate whether adenoviral-mediated gene transfer of an
endothelial nitric oxide synthase (eNOS) cDNA (AdCMVeNOS) into carotid arteries
of the SHRSP may improve endothelial function. METHODS: Enzyme activity of the
recombinant eNOS protein encoded by AdCMVeNOS was tested using a Griess assay in
endothelial cells in culture. Left carotid arteries of SHRSP were surgically
isolated and exposed to either the AdCMVeNOS or control beta-galactosidase
containing virus, (2 x 10(9) pfu/ml) ex vivo and in vivo. The vessels were
harvested 24 h after surgery and analysed by Western blotting,
immunohistochemistry and by examining endothelial function ex vivo. RESULTS:
Cultured endothelial cells showed almost 100% transduction with both viruses and
a dose response of eNOS expression showed a five-fold increase in nitrite
production for AdCMVeNOS with no change for beta-galactosidase-containing virus.
Western blotting demonstrated a significant increase of eNOS expression in
vessels infused with AdCMVeNOS when compared to controls. Immunohistochemistry
showed highly positive staining with monoclonal antibodies against eNOS in the
intact endothelial cells of the AdCMVeNOS infused vessels. The areas under the
curve of the concentration responses to phenylephrine (10(-9) to 3 x 10(-6) M) in
the absence and presence of NG-nitroarginine methyl ester (100 microM) showed
increased basal nitric oxide bioavailability in the carotid arteries infused with
AdCMVeNOS compared to the control (n = 6 for each; P = 0.0069; 95% CI, 0.864 to
3.277). CONCLUSIONS: Our results show that AdCMVeNOS is an effective tool for
vascular gene transfer and that it can improve endothelial NO availability in the
SHRSP, a genetic model of essential hypertension and endothelial dysfunction.
PMID- 10690354
TI - A pedigree-based study of mitochondrial D-loop DNA sequence variation among
Arabian horses.
AB - Through DNA sequence comparisons of a mitochondrial D-loop hypervariable region,
we investigated matrilineal diversity for Arabian horses in the United States.
Sixty-two horses were tested. From published pedigrees they traced in the
maternal line to 34 mares acquired primarily in the mid to late 19th century from
nomadic Bedouin tribes. Compared with the reference sequence (GenBank X79547),
these samples showed 27 haplotypes with altogether 31 base substitution sites
within 397 bp of sequence. Based on examination of pedigrees from a random
sampling of 200 horses in current studbooks of the Arabian Horse Registry of
America, we estimated that this study defined the expected mtDNA haplotypes for
at least 89% of Arabian horses registered in the US. The reliability of the
studbook recorded maternal lineages of Arabian pedigrees was demonstrated by
haplotype concordance among multiple samplings in 14 lines. Single base
differences observed within two maternal lines were interpreted as representing
alternative fixations of past heteroplasmy. The study also demonstrated the
utility of mtDNA sequence studies to resolve historical maternity questions
without access to biological material from the horses whose relationship was in
question, provided that representatives of the relevant female lines were
available for comparison. The data call into question the traditional assumption
that Arabian horses of the same strain necessarily share a common maternal
ancestry.
PMID- 10690353
TI - Highly efficient liposome-mediated gene transfer of inducible nitric oxide
synthase in vivo and in vitro in vascular smooth muscle cells.
AB - OBJECTIVE: The efficient introduction of regulatory genes into vascular smooth
muscle cells (SMCs) is one of the most promising options for gene therapy of
cardiovascular diseases. Cationic liposome-mediated gene transfer may become a
favorable transfection technique with regard to patient's safety for in vivo
administration. However, this method until now has its limitation in a low
transfection efficiency. Therefore, the present study was designed to improve
cationic liposome-mediated transfection of rabbit vascular SMCs in vitro and in
vivo, in order to enhance transfection efficiency and present an optimized system
which may offer a potential therapeutic benefit for in vivo application. METHODS
AND RESULTS: Optimized lipofection of rabbit SMCs with the mammalian expression
vector pE-N1 and the reporter gene green fluorescent protein resulted in a mean
transfection efficiency of about 50%. The unique transfection of rabbit SMCs in
vitro and in vivo with the inducible isoform of human nitric oxide synthase
(NOSII), using the same vector, resulted in a successful transient transcription
and translation of a functionally active human NOSII in rabbit SMC, persisting 5
6 days. We could further demonstrate that the transfection procedure and the
transgene product did neither induce necrosis nor apoptosis under the conditions
chosen and did not result in the induction of endogenous NOSII of transfected
SMCs. CONCLUSION(S): These findings indicate potential therapeutic relevance for
this nonviral gene transfer system for in vivo gene therapy for cardiovascular
diseases.
PMID- 10690355
TI - Construction and evaluation of a porcine bacterial artificial chromosome library.
AB - A porcine bacterial artificial chromosome (BAC) library consisting of 103,488
clones has been constructed. The average insert size in the BAC vector was
calculated to be 133 kb based on the examination of 189 randomly selected clones,
indicating that the library contained 4.4 genome equivalents. The library can be
screened by two-step PCR. The first screening step is performed on 22 superpools,
each containing 4704 clones (49 x 96 well plates). In the second screening step,
49 plates comprising a superpool are arrayed in a 7 x 7 matrix and 4D-PCR is
performed. Screening of the library superpools by PCR for 125 marker sequences
selected from different regions of swine genome revealed 123 sequences,
indicating that the library is not biased. Subsequent screenings (4D-PCR) were
successfully applied for identification of clones containing each marker
sequence. This porcine BAC library and the PCR screening system are useful for
isolation of genomic DNA fragments containing desired sequences.
PMID- 10690357
TI - Integration of the genetic and physical maps of the chicken macrochromosomes.
AB - A large amount of genetic mapping information has been obtained in the chicken
from the East Lansing, Compton and Wageningen reference populations. Physical
mapping information has however, been more limited. We have mapped 14 new clones,
both genetically and physically, and all 14 have been assigned to
macrochromosomes. The orientation of linkage groups E01C01C11W01 (Chr 1),
E06C02W02 (Chr 2), E02C03W03 (Chr 3), E05C04W04 (Chr 4), E07E34C05W05 (Chr 5),
E11C10W06 (Chr 6), E45C07W07 (Chr 7) and E43C12W11 (Chr 8) has been established.
Here we present integrated maps of the eight macrochromosomes and the Z
chromosome of the chicken and correlate genetic with physical distances for
chromosomes 1-3 and the Z sex chromosome.
PMID- 10690356
TI - Chediak-Higashi syndrome mutation and genetic testing in Japanese black cattle
(Wagyu).
AB - Chediak-Higashi Syndrome (CHS) is an autosomal recessive disorder that affects
several species including mice, humans, and cattle. Evidence based on clinical
characteristics and somatic cell genetics suggests that mutations in a common
gene cause CHS in the three species. The CHS locus on human chromosome 1 and
mouse chromosome 13 encodes a lysosomal trafficking regulator formerly known as
LYST, now known as CHS1, and is defective in CHS patients and beige mice,
respectively. We have mapped the CHS locus to the proximal region of bovine
chromosome 28 by linkage analysis using microsatellite markers previously mapped
to this chromosome. Furthermore, we have identified a missense A:T-->G:C mutation
that results in replacement of a histidine with an arginine residue at codon 2015
of the CHS1 gene. This mutation is the most likely cause of CHS in Wagyu cattle.
In addition, we describe quick, inexpensive, PCR based tests that will permit
elimination of the CHS mutation from Wagyu breeding herds.
PMID- 10690358
TI - Identification and characterization of a new allele for the beta subunit of
follicle-stimulating hormone in Chinese pig breeds.
AB - During evaluation of follicle-stimulating hormone-beta (FSHB) expression in
anterior pituitary glands by an RNase protection assay (RPA), the expected
fragment of 205 nucleotides at positions 759-963 was not detected in one boar
that had moderate plasma and pituitary FSH concentrations. After subcloning and
sequencing, mRNA from this boar lacked an 11-bp fragment (5'-CATTTGGAAAC-3') at
nucleotide positions 807-817 of the 3'-untranslated region (3'-UTR, D allele).
Wild-type FSHB (WT allele) was present in pituitary RNA and genomic DNA in both
Meishan (MS) and White Composite (WC) pigs; whereas the D allele was present only
in MS pigs (P < 0.01; 5/6 MS vs. 0/6 WC). Also, we found the D allele in five
other Chinese breeds but absent in ten American Landrace, 11 Yorkshire and 17
Berkshire pigs. Additionally, the D allele had one silent nucleotide change in
the coding region plus six, single nucleotide changes in the 3'-UTR.
PMID- 10690359
TI - Microsatellite analysis reveals substantial genetic differentiation between
contemporary New World and Old World Holstein Friesian populations.
AB - Genotypic data from 39 microsatellite loci typed in 211 animals were used to
assess the genetic differentiation between Old World and New World Holstein
Friesian cattle populations. Gene diversities were similar in all five Holstein
Friesian populations surveyed, ranging from 0.43 to 0.48. A tree of individuals
based on the proportion of shared alleles indicated a clear distinction between
Old World and New World Holstein Friesian populations. Similarly, genetic
differentiation between populations, as measured by FST, was highly significant.
Using the split decomposition method, we were able to visualize the significant
introgression of New World Holstein Friesian into European Holstein Friesian
populations.
PMID- 10690360
TI - The genetic structure of Spanish Celtic horse breeds inferred from microsatellite
data.
AB - Partition of the genetic variability, genetic structure and relationships among
seven Spanish Celtic horse breeds were studied using PCR amplification of 13
microsatellites on 481 random individuals. In addition, 60 thoroughbred horses
were included. The average observed heterozygosity and the mean number of alleles
were higher for the Atlantic horse breeds than for the Balearic Islands breeds.
Only eight percentage of the total genetic variability could be attributed to
differences among breeds (mean FST approximately 0.08; P < 0.01). Atlantic breeds
clearly form a separate cluster from the Balearic Islands breeds and among the
former only two form a clear clustering, while the rest of Atlantic breeds (Jaca
Navarra, Caballo Gallego and Pottoka) are not consistently differentiated.
Multivariate analysis showed that Asturcon populations, Losina and Balearic
Islands breeds are clearly separated from each other and from the rest of the
breeds. In addition to this, the use of the microsatellites proved to be useful
for breed assignment.
PMID- 10690361
TI - Biochemical, molecular and physiological characterization of a new beta-casein
variant detected in Korean cattle.
AB - There are seven known genetic variants of bovine beta-casein (beta-CN)--A1, A2,
A3, B, C, D and E. In this study, we identified a new genetic variant (named beta
CN H) which migrates slower than the other variants in acidic starch gel
electrophoresis. We confirmed through protein and DNA sequence analyses that the
H variant differs at five residues from the A2 sequence: Arg25/Cys, Leu88/Ile,
Gln117/Glu, Glu175/Gln and Gln195/Glu. Of these substitutions the 25th residue
was contained in the casein phosphopeptide (CPP) region. In rats, calcium
solubilizing effect of the CPP of bovine variant H was increased by approximately
23% compared with that of the CPP of non-H. Using extensive Korean Bos taurus
pedigrees, we confirmed that beta-CN H was controlled by a codominant allele.
PMID- 10690362
TI - Nomenclature for factors of the dog major histocompatibility system (DLA), 1998:
first report of the ISAG DLA Nomenclature Committee.
AB - A Nomenclature committee for Factors of the Dog Major Histocompatibility System
or Dog Leukocyte Antigen (DLA) has been convened under the auspices of the
International Society for Animal Genetics (ISAG) to define a sequence based
nomenclature for the genes of the DLA system. The remit of this committee
includes: assignment of gene names rules for naming alleles assignment of names
to published alleles assignment of names to new alleles rules for acceptance of
new alleles DLA Nomenclature Committee, rules for acceptance, DLA genes and
alleles, sequence based nomenclature.
PMID- 10690363
TI - Development and characterization of expressed sequence tags for the turkey
(Meleagris gallopavo) genome and comparative sequence analysis with other birds.
AB - Twenty-one randomly selected clones from a turkey (Meleagris gallopavo) pituitary
complementary DNA (cDNA) library were sequenced to develop expressed sequence
tags (ESTs) for this economically important avian species whose genome is among
the least understood. Primers specific for the ESTs were used to produce
amplicons from the genomic DNA of turkey, chicken (Gallus gallus), guinea fowl
(Numidia meleagris), pigeon (Columba domestica), and quail (Corturnix japonica).
The amplicons were sequenced and analyzed for sequence variation within- and
similarity among-species and with GenBank database sequences. The proportion of
shared bases between the turkey sequence and the consensus sequence from each of
the other species ranged from 72% to 93% between turkey and pigeon and quail and
between turkey and chicken, respectively. The total number of single nucleotide
polymorphisms (SNPs) observed ranged from 3 in quail to 18 in chicken out of 4898
and 5265 bases analyzed, respectively. The most frequent nucleotide variation
observed was a C-->T transition. Linkage analysis of one such SNP in the
backcross progeny of the East Lansing reference DNA panel, localized TUS0005, the
chicken sequence derived from primers specific for turkey TUT2E EST, to
chromosome 4. The ESTs reported, as well as the SNPs may provide a useful
resource for ongoing efforts to develop high utility genome maps for the turkey
and chicken. The primers described can also be used as a tool in future
investigations directed at further understanding the biology of the guinea fowl,
pigeon and quail and their relatedness to the turkey.
PMID- 10690364
TI - Tth111I PCR/RFLP marker in the canine rod transducin alpha (GNAT1) gene.
PMID- 10690365
TI - Ten equine microsatellite loci: TKY25, TKY26, TKY27, TKY28, TKY29, TKY267,
TKY268, TKY269, TKY270 and TKY271.
PMID- 10690366
TI - Physical assignment of the porcine erythropoietin receptor gene to SSC2.
PMID- 10690367
TI - Identification of a MaeI RFLP in the insulin-like growth factor-1 (IGF1) gene of
swamp buffaloes (Bubalus b. bubalis kerebau).
PMID- 10690368
TI - A DNA polymorphism in the bovine c-kit gene.
PMID- 10690369
TI - Variable microsatellites in the Pacific oyster Crassostrea gigas and other cupped
oyster species.
PMID- 10690370
TI - Four microsatellite markers in the Japanese flounder, Paralichthys olivaceus.
PMID- 10690371
TI - Two bovine dinucleotide repeat polymorphisms: RM084 and RM171.
PMID- 10690372
TI - Four highly polymorphic dinucleotide microsatellites in rainbow trout
(Oncorhynchus mykiss).
PMID- 10690373
TI - A diallelic short tandem repeat (CCCCG)4 or 5, located in intron 1 of rabbit
alpha-globin gene.
PMID- 10690374
TI - South American camelid microsatellite amplification in Camelus dromedarius.
PMID- 10690375
TI - A single nucleotide (T-->G) polymorphism within intron 23 of the canine BRCA1
gene.
PMID- 10690376
TI - Seven novel cosmid-derived canine microsatellites.
PMID- 10690377
TI - Characterization of ten equine dinucleotide microsatellite loci: NVHEQ21,
NVHEQ54, NVHEQ67, NVHEQ70, NVHEQ75, NVHEQ77, NVHEQ79, NVHEQ81, NVHEQ82 and
NVHEQ83.
PMID- 10690378
TI - New mutation in exon 2 of the bovine leptin gene.
PMID- 10690379
TI - 'Old Kerr's almanac'.
PMID- 10690380
TI - The control of acute menopausal symptoms in breast cancer survivors.
PMID- 10690381
TI - Recurrent squamous-cell carcinoma of the head and neck: overview of current
therapy and future prospects.
AB - Locoregional recurrence is the most common cause of failure after head and neck
cancer surgery. It is a disease which causes significant morbidity especially on
speech and swallowing. There are many different treatments available including
surgery, reirradiation and chemotherapy. However, none of these have produced any
significant survival benefit. Because of this, there has been considerable
interest in the development of new biological therapies such as gene therapy and
immunotherapy for this disease. The objectives of this article are to provide an
overview of the currently available therapies for recurrent head and neck cancer
including gene therapy and immunotherapy. Prevention of recurrent disease by the
detection and treatment of minimal residual disease is also discussed.
PMID- 10690382
TI - A pilot trial assessing the efficacy of paroxetine hydrochloride (Paxil) in
controlling hot flashes in breast cancer survivors.
AB - BACKGROUND: Many breast cancer survivors suffer debilitating hot flashes.
Estrogen, the drug of choice in perimenopausal women, is generally not
recommenced to breast cancer survivors. Nonhormonal treatments are mostly
disappointing. Anecdotal reports in our institution suggested that the selective
serotonin-reuptake inhibitor, paroxetine hydrochloride, might be efficacious in
alleviating hot flashes. PATIENTS AND METHODS: Thirty women with prior breast
cancer who were suffering at least two hot flashes a day entered a single
institution pilot trial to evaluate paroxetine's efficacy in reducing the
frequency and severity of hot flashes. After completing daily diaries for one
week on no therapy, the women received open-label paroxetine, 10 mg daily for one
week, followed by four weeks of paroxetine, 20 mg daily. The women completed hot
flash daily diaries throughout the study period, and a health-related symptom
assessment questionnaire and a quality-of-life rating scale in the first and
sixth week of the study. RESULTS: Twenty-seven women completed the six-week study
period. The mean reduction of hot flash frequency was 67% (95% confidence
interval (95% CI): 56%-79%). The mean reduction in hot flash severity score was
75% (95% CI: 66%-85%). There was a statistically significant improvement in
depression, sleep, anxiety, and quality of life scores. Furthermore, 25 (83%) of
the study participants chose to continue paroxetine therapy at the end of study.
The most common adverse effect was somnolence, resulting in drug discontinuation
in two women, and dose reduction in two women. One woman discontinued drug due to
anxiety. CONCLUSIONS: Paroxetine hydrochloride is a promising new treatment for
hot flashes in breast cancer survivors, and warrants further evaluation in a
double-blind randomized placebo-controlled trial.
PMID- 10690383
TI - A clinical model for quality of life assessment in cancer patients receiving
chemotherapy.
AB - BACKGROUND: The pattern of symptoms experienced by cancer patients during
chemotherapy is very complex. Consequently, quality of life (QOL) assessment has
to be carefully planned to capture clinically relevant changes. PATIENTS AND
METHODS: A clinical model of changes in symptoms experienced by symptomatic
metastatic patients during several courses of chemotherapy has been developed.
The model differentiates cancer-related symptoms, acute side-effects, chronic
side-effects and symptoms not related to cancer. The model was used to predict
changes in each of these four symptom groups. Three time points were selected
(post-cycle 2, pre-cycle 3, post-cycle 5) and an appropriate window around each
time point was set. The model predictions were tested empirically with 56
patients with advanced ovarian cancer who completed the EORTC QLQ-C30 plus
disease specific items during a six-cycle course of chemotherapy. RESULTS: The
changes observed in the sample were in accordance with the changes predicted by
the clinical model. Results from patients who did not complete the questionnaire
within the specified time windows tended to dilute the findings from the group
who did. CONCLUSIONS: A clinical model is useful in the planning of QOL
assessments in order to capture clinically relevant effects. Such models also
facilitate the interpretation of QOL studies, particularly when cyclic short-term
effects and chronic side-effects are overlaid on disease symptoms, as is the case
with chemotherapy for cancer.
PMID- 10690384
TI - Assessment of hospitalised cancer patients' needs by the Needs Evaluation
Questionnaire.
AB - BACKGROUND: Cancer disease modifies the order and the nature of needs connected
with the state of health. The aim of this study was to evaluate the informative,
psychological, social and practical needs of hospitalised cancer patients by
means of the Needs Evaluation Questionnaire (NEQ), an instrument designed
concisely for the convenience of patients and medical staff. PATIENTS AND
METHODS: Different samples of consecutive hospitalised cancer patients were
involved in the various phases of designing the instrument: 30 patients for items
identification, 101 patients for completeness and acceptability evaluation, 423
patients for construct validity and prevalence of needs; content and reliability
analysis were performed on 2 subsamples of, respectively, 60 and 88 of the
patients from the last sample. RESULTS: The validation analysis showed rather
good reliability, structure validity and internal consistency of the
questionnaire. The prevalence analysis showed that the most common needs were:
'more information about my future conditions' (74%); 'more information about my
diagnosis' (56%); 'more information about the exams I am undergoing' (52%); 'more
explanations on treatments' (51%); 'to have a better dialogue with clinicians'
(57%); 'better services from the hospital' (bathrooms, meals, cleaning) (56%).
CONCLUSIONS: The NEQ, self-completed by patients, has proven to be a useful
clinical tool for obtaining a systematic and undistorted overview of the
principal needs with respect to the state of health of patients. This instrument,
which can also be administered by persons not belonging to the health care system
such as volunteers, and inserted into the patients' hospital charts, could be
used by the medical staff to identify the real needs of patients at an early
stage.
PMID- 10690385
TI - Patient participation in medical decision-making: a French study in adjuvant
radio-chemotherapy for early breast cancer.
AB - BACKGROUND: Shared decision-making is increasingly advocated as an ideal model.
However, very few studies have tested the feasibility of giving patients the
opportunity to participate in the choice of treatment. PATIENTS AND METHODS:
Women, with non-metastatic breast cancer, eligible for non-intensified adjuvant
chemotherapy attending our hospital were proposed two administrations of
chemotherapy and radiotherapy: a sequential and a concomitant one. Two patient
questionnaires were used to elicit motivations for their choice and their degree
of comfort with the process of decision-making and one questionnaire to test
physicians' ability to predict patients' choice. RESULTS: Participation rate in
the study was 75.3% (n = 64). Majority (64%) of patients chose the concomitant
treatment. Multivariate analysis revealed that patients with a lower level of
education, who discussed the choice with social circle, and who most feared side
effects were more likely to choose the sequential treatment. Physicians were able
to predict patients' choice in 66% of cases. 89% of patients declared that they
were fully satisfied with having participated in the choice of treatment and 79%
supported shared decision-making. CONCLUSIONS: Results are in favour of promoting
active participation of cancer-patients in medical decision-making. The adequate
degree of such participation remains however to be elicited and tested for
therapeutic choices implying more difficult trade-offs between quantity and
quality of life.
PMID- 10690386
TI - Mature B-cell lymphoma/leukemia in children and adolescents: intergroup
pathologist consensus with the revised European-American Lymphoma Classification.
AB - BACKGROUND: The Revised European-American Lymphoma (R.E.A.L.) Classification
criteria were evaluated in the international protocol FAB LMB 96 Treatment of
Mature B-cell Lymphoma/Leukemia: A SFOP LMB 96/CCG-5961/UKCCSG NHL 9600
Cooperative Study. This includes B-lineage lymphomas: Burkitt's lymphoma
(including ALL-L3); high-grade B-cell lymphoma, Burkitt-like; diffuse large B
cell lymphoma (excluding anaplastic large cell Ki-1 lymphoma). PATIENTS AND
METHODS: Cases were independently reviewed by eight hematopathologists from the
three cooperative national groups (two SFOP, two CCG, four UKCCSG), without prior
discussion of classification criteria or guidelines for case rejection. Consensus
diagnosis was determined by each national cooperative group, and final consensus
diagnosis established when at least two national consensus diagnoses were in
agreement, or following group agreement at a multiheaded microscope. RESULTS: Two
hundred eight cases were reviewed, with final consensus diagnosis established in
two hundred three. The percent agreement of each group's national consensus
diagnosis with final consensus diagnosis was 86%, 86% and 71%. The percent
agreement of the group's national consensus diagnosis with final consensus
diagnosis for Burkitt's and diffuse large B-cell lymphoma were 88% and 80%,
respectively, but only 42% for Burkitt-like lymphoma. CONCLUSIONS: International
panel review of mature B-cell lymphoma/leukemia in children and adolescents
highlighted difficulties in subclassification, particularly with Burkitt-like,
which is a 'provisional entity' in the R.E.A.L. Classification. The absence of
previous discussion of classification and guidelines for case rejection may in
part explain the discrepancy between pathologists. These results underline that
morphology may need to be complemented by other studies, such as molecular
genetic and cytogenetics, to discriminate between the mature B-cell lymphomas.
PMID- 10690388
TI - Hodgkin's disease: correlation between causes of death at autopsy and clinical
diagnosis.
AB - PURPOSE: The causes of mortality in Hodgkin's disease patients are insufficiently
known. Autopsy study is the fundamental procedure in the investigation of these
causes. The present study analyzes the autopsies performed in a series of
patients diagnosed as having Hodgkin's disease, determining the cause of death in
each case and comparing the premortem clinical data and the postmortem findings.
PATIENTS AND METHODS: A total of 486 patients diagnosed as having Hodgkin's
disease between 1967 and 1996 were assessed. Autopsy was performed in 40 of the
144 deceased patients (28%). We reviewed the pathological findings, effects of
treatment, discordance between the clinical diagnosis and the outcome of autopsy,
and cause of death in each case. RESULTS: The most common clinical causes of
death in those patients with autopsy study were tumor progression (37%) and
infections (43%) in those patients with autopsy study. The rate of discordance
between the clinical and autopsy diagnoses in this study was 43%. The most
frequent location of residual Hodgkin's disease was in the lymph nodes.
CONCLUSIONS: Autopsy study in Hodgkin's disease confirms a high rate of
discrepancy between final clinical diagnosis and postmortem lesions despite
advances in diagnostic methods. Autopsy revealed causes of death directly related
to the treatment, as well as some lesions directly related to patient death and
secondary to treatment. Infectious processes are likely to remain undetected and
their symptoms can mimic tumor progression.
PMID- 10690387
TI - Relapses of childhood anaplastic large-cell lymphoma: treatment results in a
series of 41 children--a report from the French Society of Pediatric Oncology.
AB - PURPOSE: To study response to chemotherapy and the outcome of children treated
for a relapsed anaplastic large-cell lymphoma (ALCL) and to evaluate the role of
bone marrow transplantation (BMT) in these patients. PATIENTS AND METHODS:
Clinical data concerning the 41 relapses that occurred in 119 patients with ALCL
enrolled in 3 consecutive studies since 1975 were analysed. First-line treatment
consisted of intensive chemotherapy according to the COPAD protocol for the first
series of 12 patients treated between 1975 and 1989 and to the SFOP (French
Society of Pediatric Oncology) HM protocols for the 30 patients treated between
1989 and 1997. Twenty-eight patients were treated with CV(B)A (CCNU, vinblastine,
ara-C with or without bleomycin), and the others with miscellaneous protocols for
recurrent disease. Fifteen patients underwent autologous BMT and 1 allogeneic BMT
while in CR2. RESULTS: Thirty-six of forty-one (88%) patients achieved CR2. With
a median follow-up of 5 years, 12 patients died, 9 of their disease and 29
patients are alive in CR2 (20 patients), CR3 (5 patients), CR4 (2 patients), CR5
(1 patient) or CR6 (1 patient). Overall and disease-free survival are
respectively 69% (53%-82%) and 44% (29%-61%) at three years. In univariate
analysis, patients treated with ABMT while in CR2 did not appear to have a better
outcome than the other. Remarkably, a long-lasting remission was obtained in 8 of
13 patients treated with weekly vinblastine for a relapse including 6 relapses
occurring after ABMT. CONCLUSIONS: Relapsed ALCL are highly chemosensitive but
over 40% of the patients experience several relapses. Prolonged conventional
chemotherapy based on vinblastine might, in some cases, be as efficient as short
intensive treatment with ABMT.
PMID- 10690389
TI - Second primary malignancies following the treatment of early stage ovarian
cancer: update of a study by the National Cancer Institute of Canada--Clinical
Trials Group (NCIC-CTG).
AB - BACKGROUND: Ovarian cancer is the leading cause of death from gynecological
malignancies and the fourth most frequent fatal malignancy in women. Despite
improved surgical techniques as many as 20% of women with early stage disease
will eventually relapse and die from their disease. The post-operative management
of these women remains controversial. Here we present the long term follow-up
data of our previously published study, as well as the incidence of second
primary malignancies in these women. PATIENTS AND METHODS: Two hundred fifty
seven eligible patients with stage I, IIA 'high risk' ovarian carcinoma and IIB,
IIIO (disease confined to pelvis) were randomized to either whole abdominal
radiotherapy 2.250 rads in ten fractions (107 patients), melphalan 8 mg/m2/d x 4
weeks x 18 courses (106 patients) or intraperitoneal chromic phosphate 10-20 mCi
(44 patients). All patients were initially treated with pelvic radiotherapy.
RESULTS: Overall survival estimates at 10 years were: 45% in the whole abdominal
radiotherapy arm; 49% in the melphalan arm and 50% in the intraperitoneal chromic
phosphate arm (P = 0.30). Relapse-free survival estimates at 10 years were: 50%
in the whole abdominal radiotherapy arm, 62% in the melphalan arm and 51% in the
chromic phosphate arm (P = 0.147). Long term follow-up has not demonstrated a
significant difference between treatment arms. Second primary malignancies
developed in 29 women (11%) after 2,229 person years of follow-up. This compares
to 18.7 second primary malignancies which would have been expected in this group
of age-matched controls and was statistically significant (P = 0.018). There was
no significant difference in the total number of second primary malignancies
between treatment arms. Melphalan appeared to be associated with an increased
risk of developing leukemia/myelodysplastic syndrome compared to the whole
abdominal radiotherapy arm (P = 0.06). CONCLUSIONS: Long-term follow-up has not
demonstrated a significant difference in overall or disease free survival between
treatment arms. An excess of second primary malignancies (35%) was observed
suggesting that lifelong surveillance is required in this population. Further
research with newer treatment programs are needed to improve the cure rates in
this population.
PMID- 10690392
TI - BRCA2 germ-line mutations in Spanish male breast cancer patients.
AB - BACKGROUND: Mutations in the BRCA2 gene account for the majority of the families
with male and female breast cancer cases, and a number of BRCA2 mutations have
been reported in males with breast cancer. The aim of this study was to
characterise BRCA2 germ-line mutations in Spanish male breast cancer patients.
PATIENTS AND METHODS: We screened DNA from 11 affected men and 6 women with
breast cancer (BC) who had an affected male relative (father or brother). Exons 2
9 and 12-27 were screened by SSCP, and exons 10 and 11 were screened by PTT. PCR
products with a variant band were sequenced. RESULTS: Three BRCA2 frameshift
mutations were identified (17.6%): the 3374delA in codon 1049 (exon 11),
6857delAA in codon 2010 (exon 11), and 9254delATCAT in codon 3009 (exon 23).
These mutations were present in patients with affected first-degree relatives (3
of 9, 33%). The proportion of male patients with a family history of BC in at
least one first-degree relative was 53%. CONCLUSIONS: There is an association
between BRCA2 mutations and male breast cancer, especially in those with a family
history of BC. The high prevalence of BRCA2 mutations among males should be
considered when estimating risk for female relatives. All new male cases of BC
should be regarded as being possibly inherited and should be fully investigated.
PMID- 10690391
TI - A dose-finding study of gemcitabine and vinorelbine in advanced previously
treated malignancies.
AB - PURPOSE: Gemcitabine and vinorelbine are active drugs with broad spectrum of
activity and manageable toxicity in clinical trials. The aims of this study were
to describe the toxicity, to determine the dose-limiting toxicity, and to define
the doses of gemcitabine and vinorelbine to be recommended for phase II studies
in patients with advanced cancers. PATIENTS AND METHODS: Drugs were given as 30
min infusions on day 1 and 8 (vinorelbine before gemcitabine) every 3 weeks.
Thirty-six patients (male:female ratio 25:11; mean age 54, PS > 60) were treated
including 1 retroperitoneal sarcoma, 7 head and neck, 10 lung, 4 thyroid, 6
pancreatic, 1 bladder, 2 ovary, 2 gastric, 1 rectum, 1 unknown primary, and 1
renal cell carcinoma. Doses of gemcitabine/vinorelbine ranged from 800/20 mg/m2
to 1500/30 mg/m2. RESULTS: The dose-limiting toxicity was neutropenia. A
transient grade 2-3 elevation of transaminases was frequently observed at several
dose-levels, although this toxicity did not appear to be dose dependant and was
reversible at day 21 before the next cycle. Other toxicities were mild and easily
manageable, consisting of fatigue and flu-like syndromes. Since the MTD was not
reach at the higher dose-level, the recommended dose level of the gemcitabine
vinorelbine combination was 1500/30 mg/m2. One toxic death due to hematologic
toxicity was reported in a heavily pretreated patient who underwent prior
chemotherapy and pelvic radiotherapy. A total of 12 patients were treated at the
recommended dose level which was associated with grade 3-4 neutropenia in 3 of 12
patients and in 22.9% of cycles. CONCLUSIONS: This study estimates that the
recommended dose for phase II studies of gemcitabine-vinorelbine is 1500/30 mg/m2
at day 1 and 8 every three weeks. A careful monitoring of the hematologic
toxicity is recommended in heavily pretreated patients and in patients who
received pelvic radiotherapy. Partial responses observed in a patient with an
advanced cisplatin-5-fluorouracil-resistant pancreatic adenocarcinoma and in a
patient with mesothelioma support further evaluation of this combination in
patients with tumors refractory to classical antitumor agents.
PMID- 10690390
TI - Liposomal vincristine in relapsed non-Hodgkin's lymphomas: early results of an
ongoing phase II trial.
AB - OBJECTIVE: Vincristine is an active agent in lymphomas, but is often neurotoxic,
and the resulting dose reductions have been associated with lower remission and
survival rates in Hodgkin's disease. Liposomal vincristine (Onco-TCS) has
prolonged half-life, reaches higher concentration in tumors and lymph nodes than
in nerves, and administered at full doses appears to be less neurotoxic, and more
active then free vincristine in mice bearing L-1210 and P-388 leukemias. We
therefore explored its activity in relapsed non-Hodgkin's lymphomas (NHL) and
acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Eligible patients had
histologically proven relapse, age > or = 16 years, normal renal function,
neutrophils > 500/microliter, platelets > 50,000/microliter, and no HIV
infection, central nervous system disease, or serious neuropathy. Patients were
treated with 2.0 mg/m2 of liposomal vincristine i.v. over 60 minutes q 14 days.
Responders received up to 12 injections. RESULTS: Of the 51 registered patients,
35 are currently evaluable for response. Median age was 62 years (range 19-86),
and 21 were male. The median number of prior regimens was 3 (range 1-10) and had
included vincristine in all patients, of whom 51% were refractory to their last
regimen. Serum LDH was high in 46%, and beta 2-microglobulin > 3.0 mg/l in 63% of
patients. Of the 155 administered injections, 138 (89%) were at the 2.0 mg/m2
level. The median injected dose was 3.8 mg (range 2.6-4.8 mg), and median number
of injections was 4 (range 1-12). Responses were seen in 14 of 34 (41%) patients
with NHL (95% confidence intervals (95% CI) 25%-59%). Response rates were 10% for
indolent, 71% for transformed, and 47% for aggressive NHL, but the 95% confidence
intervals overlapped. Median progression-free survival was 5.5 months for
responders. Grade 3-4 motor or sensory neuropathy was seen in 11, and caused
termination of therapy in five patients. All five had prior neuropathy, two had
previously received paclitaxel, one platinum, and two paclitaxel and platinum.
Fever was detected in three patients, but there were no toxic deaths.
CONCLUSIONS: Liposomal vincristine is active and well tolerated in this heavily
pretreated population with relapsed NHL, but can be neurotoxic in a fraction of
patients heavily exposed to prior neurotoxic agents. These data, if confirmed,
would suggest a potential role for liposomal vincristine in the combination
therapy of previously untreated patients with NHL.
PMID- 10690393
TI - Paclitaxel plus vinorelbine: an active regimen in metastatic breast cancer
patients with prior anthracycline exposure.
AB - PURPOSE: To evaluate the anti-tumour activity and tolerance of the combination of
paclitaxel plus vinorelbine in metastatic breast cancer (MBC) patients previously
treated with anthracyclines. PATIENTS AND METHODS: Fifty-six MBC patients who
have had at least one previous anthracycline-containing chemotherapy regimen were
enrolled in this phase II trial. Patients received paclitaxel (135 mg/m2 over one
hour infusion) and vinorelbine (30 mg/m2) both on day 1 of each three-week course
of therapy (maximum eight courses or until disease progression was evident).
RESULTS: Six complete and nineteen partial responses were observed among the
fifty-four assessable patients (response rate of 46%, 95% CI: 33%-60%). Responses
were observed in all disease sites and in all subsets of patients. The response
rates when paclitaxel plus vinorelbine were used as first, second and third-line
chemotherapy for metastases were 67%, 41% and 35%, respectively. The response
rate among anthracycline-refractory patients was 46% (6 of 13). Median time to
progression in the overall patient group was 28 weeks. The main toxicities (CTC
grade 2 or more) were alopecia, myelosuppression and peripheral neuropathy (85%,
46% and 19% of patients, respectively). Nine patients (17%) had neutropenic fever
in fifteen of the three hundred twenty-eight courses administered (5%).
CONCLUSIONS: The combination of paclitaxel and vinorelbine on day 1 every three
weeks is active in MBC patients with prior anthracycline exposure. The regimen is
safe, well tolerated and convenient for the patients.
PMID- 10690394
TI - Epstein-Barr virus association in classical Hodgkin's disease provides survival
advantage to patients and correlates with higher expression of proliferation
markers in Reed-Sternberg cells.
AB - BACKGROUND: Most Epstein-Barr virus (EBV) associated lymphoproliferative
disorders have high proliferation indices. However, classical Hodgkin's disease
(cHD) is heterogeneous, with respect to proliferation index of the Reed-Sternberg
cell (RS cell), and EBV association. Hence, we investigated whether cHD with and
without EBV-association differ with respect to the proliferation index of the RS
cells. Further we investigated whether this would have a bearing on patients
survival. PATIENTS AND METHODS: We investigated 110 cases of cHD for: a) EBV
association by immunohistochemical demonstration of EBV-latent membrane protein-1
and EBV encoded nuclear RNA 1 by mRNA in situ hybridisation; b) Proliferating
cell nuclear antigen (PCNA) expression in the RS cells. RESULTS: EBV association
was noted in 86 of 110 cases (78%). Higher PCNA expression (P = 0.004) and
younger age (P = 0.001) correlated independently with EBV association. The 10
year relapse free survival (RFS) of EBV+ and EBV- patients were 60% and 44%,
respectively (P = 0.03). The 10 year overall survival (OS) of EBV+ and EBV-
patients were 85% and 64%, respectively (P = 0.03). EBV association maintained
its significant impact on RFS and OS within Cox proportional hazard model.
CONCLUSIONS: Our study suggests that EBV is likely to confer a higher PCNA
expression and also contribute towards maintaining the RS cells of cHD in cell
cycle. Hence, RS cells in EBV associated cHD would be more responsive to
chemotherapy and radiotherapy associated DNA damage. Thus, EBV-association
provides survival advantage to cHD patients treated with standard chemotherapy
and radiotherapy protocols.
PMID- 10690395
TI - Parathyroid hormone-related protein in metastatic breast cancer induced
hypercalcemia: a case report.
PMID- 10690396
TI - Phase II study of the multitargeted antifolate LY231514 (ALIMTA, MTA, pemetrexed
disodium) in patients with advanced pancreatic cancer.
AB - PURPOSE: To determine the safety and activity of LY231514 (ALIMTA, MTA,
pemetrexed disodium, Eli Lilly and Co., Indianapolis, IN) in chemotherapy-naive
patients with advanced pancreatic cancer. PATIENTS AND METHODS: Patients with
unresectable or metastatic pancreatic cancer received LY231514 600 mg/m2 as a 10
minute infusion every three weeks. RESULTS: Forty-two patients were enrolled in
this phase II trial. The median age was 60.3 (range 37-77) years; 79% had
metastatic disease. Neutropenia was common (40% of patients > or = grade 3) but
infectious complications were rare. Significant anemia or thrombocytopenia
occurred in < 20% of patients. Non-hematologic toxicities included grade 2 or 3
skin reaction which was ameliorated by dexamethasone. Elevations of bilirubin or
transaminases were infrequent (< 25% of patients) and did not require dose
reductions or treatment delays. Thirty-five patients received two cycles of
therapy and were evaluable for response. One complete (duration 16.2 months) and
one partial (duration 6.9 months) were observed resulting in an objective
response rate of 5.7% for evaluable patients. In addition, 17 patients (40%) had
stable disease that lasted > or = 6 months in 5 patients. The median survival was
6.5 months, with 28% of patients alive at one year. CONCLUSIONS: LY231514 is a
well-tolerated agent with minimal objective antitumor activity in pancreatic
cancer. The median and one year survival times, which may be important indicators
in phase II trials of new agents, are of interest. Combination trials of LY231514
in pancreatic cancer are planned.
PMID- 10690397
TI - Socio-economic deprivation and stage of disease at presentation in women with
breast cancer.
AB - BACKGROUND: This study describes and compares the pathological prognostic factors
and surgeon assessment of stage of breast cancer of women living in affluent and
deprived areas to assess whether clinical stage at presentation may explain the
known poorer survival outcomes for deprived women. PATIENTS AND METHODS: A
population-based review of the case records of 417 women with breast cancer was
carried out. RESULTS: No difference in pathological criteria was found between
the 88% of women living in affluent and deprived areas for whom such data were
available. Clinical assessment of the remaining 50 cases showed that women living
in deprived areas were more likely to present with locally advanced or metastatic
disease. CONCLUSION: The poorer survival of women from deprived areas with breast
cancer may be explained by more deprived women presenting with advanced cancers.
PMID- 10690398
TI - A phase I-II study of gemcitabine and paclitaxel in advanced non-small-cell lung
cancer patients.
AB - Thirty patients with chemotherapy-naive advanced non-small-cell lung cancer
(NSCLC) were given escalating doses of paclitaxel (150, 175, 200 mg/m2) on day 1
in three consecutive cycles, together with a fixed dose of gemcitabine 1000 mg/m2
on days 1 and 8; cycles were repeated every three weeks. The dose escalation of
paclitaxel was feasible in the majority of patients. Subsequently, 30 other NSCLC
patients received a dose of 200 mg/m2 paclitaxel with gemcitabine 1000 mg/m2 in a
phase II study. The major side effect was mild myelosuppression. A response rate
of 24% was achieved in 49 fully evaluable patients. This regimen proved to be
safe and easy to administer on an out-patient setting, and constitutes now one of
the arms of the current EORTC randomized study for advanced NSCLC.
PMID- 10690399
TI - A phase II study of pegylated liposomal doxorubicin for treatment of advanced
hepatocellular carcinoma.
AB - BACKGROUND: Pegylated liposomal doxorubicin has an enhanced efficacy and reduced
toxicity compared with free doxorubicin. The efficacy and toxicity of pegylated
liposomal doxorubicin was investigated in patients with hepatocellular carcinoma.
PATIENTS AND METHODS: Patients with histologically confirmed, locally advanced or
metastatic hepatocellular carcinoma and a Karnofsky index > 60% were included in
this prospective single-arm study. Exclusion criteria were liver cirrhosis stage
Child-Pugh C, previous chemotherapy, or chemoembolization. Pegylated liposomal
doxorubicin was given in a dose of 30 mg/m2 every three weeks until progression
of disease. After inclusion of five patients the dose could be escalated to 40
mg/m2 in absence of toxicity grade 3 and 4. RESULTS: Sixteen patients were
evaluable for response. No objective response was achieved. The median survival
time was 140 days (95% confidence interval: 126-154 days). Treatment toxicities
grade > or = 3 comprised increased liver enzymes in patients with preexisting
grade 1 or 2 elevation (n = 6), hematologic toxicity (n = 5), and
hypersensitivity (n = 2). CONCLUSIONS: Pegylated liposomal doxorubicin is not
effective for treatment of advanced hepatocellular carcinoma. The favorable
toxicity profile was confirmed even in patients with underlying liver disease.
PMID- 10690400
TI - Combination chemotherapy with irinotecan and adriamycin for refractory and
relapsed non-Hodgkin's lymphoma.
AB - Twenty-five patients with relapsed or refractory non-Hodgkin's lymphoma were
treated by combination chemotherapy with irinotecan hydrochloride (CPT-11) and
adriamycin (ADM): CPT-11, 25 mg/m2 on days 1 and 2; ADM, 40 mg/m2 on day 3. Nine
(36%) of twenty-five patients achieved CR. Fairly good responses were seen in
relapsed B-cell lymphomas (4 of 8 in diffuse large B-cell lymphoma and 2 of 2 in
follicular lymphoma grade 1), and substantial responses in T-cell lymphomas (1 of
4 in peripheral T-cell lymphoma and 2 of 7 in adult T-cell leukemia/lymphoma).
Leukopenia was frequent but tolerable, and diarrhea minimal. Combination
chemotherapy with a reduced dose CPT-11 and ADM was useful in the treatment of
relapsed non-Hodgkin's lymphoma.
PMID- 10690401
TI - Incidence of venous thromboembolism in breast cancer patients during chemotherapy
with vinorelbine, cisplatin, 5-fluorouracil as continuous infusion (ViFuP
regimen): is prophylaxis required?
PMID- 10690402
TI - History of plant population genetics.
AB - This review of plant population genetics focuses on the genetic foundations of
the processes that have led to documentable improvements in cultivated plants
since the earliest domestications took place perhaps 13,000 years ago. Nearly all
human civilizations have depended heavily on inbreeding plants (particularly
wheat, barley, soybeans and other inbreeding legumes), as well as outbreeding
vegetatively propagated species (white potatoes, yams) as their dietary standbys.
The principal exception is maize (corn), an annual seed-produced outbreeder in
nature. It is noteworthy that maize joined wheat, rice, and barley as a truly
major crop worldwide only after its conversion to self-pollination combined with
hybridization between favorably interacting inbred lines increased yield of maize
several-fold in the twentieth century.
PMID- 10690403
TI - Fas ligand-induced apoptosis.
AB - The immune response is regulated not only by cell proliferation and
differentiation, but also by programmed cell death, or apoptosis. In response to
various stimuli, death factors bind to their respective receptors and activate
the apoptotic death program in target cells. A cascade of specific proteases
termed caspases mediates the apoptotic process. The activated caspases cleave
various cellular components, a process that leads to morphological changes of the
cells and nuclei, as well as to degradation of the chromosomal DNA. Loss-of
function mutations in the signaling molecules involved in apoptosis cause hyper
proliferation of cells in mouse and human. In contrast, exaggeration of this
death cascade causes the destruction of various tissues.
PMID- 10690405
TI - Molecular genetics of human retinal disease.
AB - The past decade has witnessed extraordinary progress in retinal disease gene
identification, the analysis of animal and tissue culture models of disease
processes, and the integration of this information with clinical observations and
with retinal biochemistry and physiology. During this period over twenty retinal
disease genes were identified and for many of these genes there are now
significant insights into their role in disease. This review presents an overview
of the basic and clinical biology of the retina, summarizes recent progress in
understanding the molecular mechanisms of inherited retinal diseases, and offers
an assessment of the role that genetics will play in the next phase of research
in this area.
PMID- 10690406
TI - Lentivirus replication and regulation.
AB - Lentiviruses are associated with chronic diseases of the hematological and
neurological systems in animals and man. In particular, human immunodeficiency
virus type 1 (HIV-1) is the etiological agent of the global AIDS epidemic. The
genomes of lentiviruses are complex, encoding a number of regulatory and
accessory proteins not found in other retroviruses. This complexity is reflected
in their replication cycle, which reveals intricate regulatory pathways and
unique mechanisms for viral persistence. In this review, we highlight some of
these unique features for HIV-1, with particular focus on the transcriptional and
posttranscriptional control of gene expression. Although our understanding of the
biology of HIV-1 is far from complete, the knowledge gained thus far has already
led to novel strategies for both virus intervention and exploiting the
lentiviruses for therapeutic applications.
PMID- 10690404
TI - Mechanisms of stationary phase mutation: a decade of adaptive mutation.
AB - A decade of research on adaptive mutation has revealed a plethora of mutagenic
mechanisms that may be important in evolution. The DNA synthesis associated with
recombination could be an important source of spontaneous mutation in cells that
are not proliferating. The movement of insertion elements can be responsive to
environmental conditions. Insertion elements not only activate and inactivate
genes, they also provide sequence homology that allows large-scale genomic
rearrangements. Some conjugative plasmids can recombine with their host's
chromosome, and may acquire chromosomal genes that could then spread through the
population and even to other species. Finally, a subpopulation of transient
hypermutators could be a source of multiple variant alleles, providing a
mechanism for rapid evolution under adverse conditions.
PMID- 10690407
TI - Shufflons: multiple inversion systems and integrons.
AB - Conservative site-specific recombination functions to create biological diversity
in prokaryotes. Simple site-specific recombination systems consist of two
recombination sites and a recombinase gene. The plasmid R64 shufflon contains
seven recombination sites, which flank and separate four DNA segments. Site
specific recombinations mediated by the product of the rci gene between any two
inverted recombination sites result in the inversion of four DNA segments
independently or in groups. The shufflon functions as a biological switch to
select one of seven C-terminal segments of the PilV proteins, which is a minor
component of R64 thin pilus. The shufflon determines the recipient specificity in
liquid matings of plasmid R64. Other multiple inversion systems as well as
integrons, which are multiple insertion systems, are also described in this
review.
PMID- 10690408
TI - Messenger RNA stability and its role in control of gene expression in bacteria
and phages.
AB - The stability of mRNA in prokaryotes depends on multiple factors and it has not
yet been possible to describe the process of mRNA degradation in terms of a
unique pathway. However, important advances have been made in the past 10 years
with the characterization of the cis-acting RNA elements and the trans-acting
cellular proteins that control mRNA decay. The trans-acting proteins are mainly
four nucleases, two endo- (RNase E and RNase III) and two exonucleases (PNPase
and RNase II), and poly(A) polymerase. RNase E and PNPase are found in a
multienzyme complex called the degradosome. In addition to the host nucleases,
phage T4 encodes a specific endonuclease called RegB. The cis-acting elements
that protect mRNA from degradation are stable stem-loops at the 5' end of the
transcript and terminators or REP sequences at their 3' end. The rate-limiting
step in mRNA decay is usually an initial endonucleolytic cleavage that often
occurs at the 5' extremity. This initial step is followed by directional 3' to 5'
degradation by the two exonucleases. Several examples, reviewed here, indicate
that mRNA degradation is an important step at which gene expression can be
controlled. This regulation can be either global, as in the case of growth rate
dependent control, or specific, in response to changes in the environmental
conditions.
PMID- 10690409
TI - Mechanisms of mRNA surveillance in eukaryotes.
AB - A conserved mRNA degradation system, referred to as mRNA surveillance, exists in
eukaryotic cells to degrade aberrant mRNAs. A defining aspect of aberrant
transcripts is that the spatial relationship between the termination codon and
specific downstream sequence information has been altered. A key, yet unknown,
feature of the mRNA surveillance system is how this spatial relationship is
assessed in individual transcripts. Two views have emerged to describe how
discrimination between proper and improper termination might occur. In the first
view, a surveillance complex assembles onto the mRNA after translation
termination, and scans the mRNA in a 3' to 5' direction for a limited distance.
If specific downstream sequence information is encountered during this scanning,
then the surveillance complex targets the transcript for rapid decay. An
alternate view suggests that the downstream sequence information influences how
translation termination occurs. This view encompasses several ideas including:
(a) The architecture of the mRNP can alter the rate of key steps in translation
termination; (b) the discrimination between a proper and improper termination
occurs via an internal, Upf1-dependent, timing mechanism; and (c) proper
termination results in the restructuring of the mRNP to a form that promotes mRNA
stability. This proposed model for mRNA surveillance is similar to other systems
of kinetic proofreading that monitor the accuracy of other biogenic processes
such as translation and spliceosome assembly.
PMID- 10690410
TI - Ribosome synthesis in Saccharomyces cerevisiae.
AB - The synthesis of ribosomes is one of the major metabolic pathways in all cells.
In addition to around 75 individual ribosomal proteins and 4 ribosomal RNAs,
synthesis of a functional eukaryotic ribosome requires a remarkable number of
trans-acting factors. Here, we will discuss the recent, and often surprising,
advances in our understanding of ribosome synthesis in the yeast Saccharomyces
cerevisiae. These will underscore the unexpected complexity of eukaryotic
ribosome synthesis.
PMID- 10690411
TI - The French school of genetics: from physiological and population genetics to
regulatory molecular genetics.
AB - French genetics had unusual beginnings. There are clear indications that the
French biological establishment resisted Mendelian genetics strenuously from
about 1910 to 1940. From about 1930 to 1950 several unconventional research
programs with a strongly physiological orientation paved the way for the full
entrance of French biology into genetics after World War II. This review examines
some salient features of this history to clarify the strengths, weaknesses, and
distinctive features of French genetics until about 1965. We suggest that after
that data French genetics slowly merged into the international mainstream as
genetics has become a largely molecular discipline.
PMID- 10690412
TI - Mitochondrial genome evolution and the origin of eukaryotes.
AB - Recent results from ancestral (minimally derived) protists testify to the
tremendous diversity of the mitochondrial genome in various eukaryotic lineages,
but also reinforce the view that mitochondria, descendants of an endosymbiotic
alpha-Proteobacterium, arose only once in evolution. The serial endosymbiosis
theory, currently the most popular hypothesis to explain the origin of
mitochondria, postulates the capture of an alpha-proteobacterial endosymbiont by
a nucleus-containing eukaryotic host resembling extant amitochondriate protists.
New sequence data have challenged this scenario, instead raising the possibility
that the origin of the mitochondrion was coincident with, and contributed
substantially to, the origin of the nuclear genome of the eukaryotic cell.
Defining more precisely the alpha-proteobacterial ancestry of the mitochondrial
genome, and the contribution of the endosymbiotic event to the nuclear genome,
will be essential for a full understanding of the origin and evolution of the
eukaryotic cell as a whole.
PMID- 10690413
TI - Genetics of chemotaxis and thermotaxis in the nematode Caenorhabditis elegans.
AB - Molecular genetic analysis of chemotaxis and theramotaxis in Caenorhabditis
elegans has revealed the molecular bases of olfaction, taste, and
thermosensation, which, in turn, has demonstrated that sensory signaling in C.
elegans is very similar to that in vertebrates. A cyclic nucleotide-gated channel
(TAX-2/TAX-4) that is highly homologous to the olfactory and photoreceptor
channels in vertebrates is required for taste and thermosensation, in addition to
olfaction. A cation channel (OSM-9) that is closely related to a capsaicin
receptor channel is required for olfactory adaptation in one olfactory neuron and
olfactory sensation in the other olfactory neuron. A novel G alpha protein (ODR
3) is essential for olfactory responses in all olfactory neurons and aversive
responses in a polymodal sensory neuron. A G protein-coupled seven-transmembrane
receptor (ODR-10) is the first olfactory receptor whose ligand was elucidated.
Using chemotaxis and thermotaxis as behavioral paradigms, neural plasticity
including learning and memory can be studied genetically in C. elegans.
PMID- 10690414
TI - Bacterial cell division.
AB - Formation of the bacterial division septum is catalyzed by a number of essential
proteins that assemble into a ring structure at the future division site.
Assembly of proteins into the cytokinetic ring appears to occur in a hierarchial
order that is initiated by the FtsZ protein, a structural and functional analog
of eukaryotic tubulins. Placement of the division site at its correct location in
Escherichia coli requires a division inhibitor (MinC), that is responsible for
preventing septation at unwanted sites near the cell poles, and a topological
specificity protein (MinE), that forms a ring at midcell and protects the midcell
site from the division inhibitor. However, the mechanism responsible for
identifying the position of the midcell site or the polar sites used for spore
septum formation is still unclear. Regulation of the division process and its
coordination with other cell cycle events, such as chromosome replication, are
poorly understood. However, a protein has been identified in Caulobacter (CtrA)
that regulates both the initiation of chromosome regulation and the transcription
of ftsZ, and that may play an important role in the coordination process.
PMID- 10690415
TI - Toward an integrated genetic epidemiology of parasitic protozoa and other
pathogens.
AB - Due to the increase of human migrations, the appearance of emerging and
reemerging endemies, growing antibiotic resistance, and climatic changes,
infectious diseases most probably constitute the major challenge for medicine in
the next century. The advent of molecular methods of pathogen characterization
has considerably improved our knowledge of the epidemiology of these diseases.
However, the use of concepts of evolutionary genetics for interpreting "molecular
epidemiology" data remains limited, although the application of such methods
would broaden considerably the scope of this field of research, and allow
epidemiologic and taxonomic approaches to be ascertained on a much firmer basis.
In turn, pathogens, hosts, and vectors provide fascinating models for basic
research. The artificial character of the border between "basic" and "applied"
research is especially apparent with regard to the "integrated genetic
epidemiology of infectious diseases" concept. The goal of this chapter is to
evaluate the respective impact, on the transmission and pathogenicity of
infectious diseases, of the host's, the pathogen's, and the vector's (for vector
borne diseases) genetic diversity, and the interactions between these three
parameters (coevolution phenomena).
PMID- 10690416
TI - Plant retrotransposons.
AB - Retrotransposons are mobile genetic elements that transpose through reverse
transcription of an RNA intermediate. Retrotransposons are ubiquitous in plants
and play a major role in plant gene and genome evolution. In many cases,
retrotransposons comprise over 50% of nuclear DNA content, a situation that can
arise in just a few million years. Plant retrotransposons are structurally and
functionally similar to the retrotransposons and retroviruses that are found in
other eukaryotic organisms. However, there are important differences in the
genomic organization of retrotransposons in plants compared to some other
eukaryotes, including their often-high copy numbers, their extensively
heterogeneous populations, and their chromosomal dispersion patterns. Recent
studies are providing valuable insights into the mechanisms involved in
regulating the expression and transposition of retrotransposons. This review
describes the structure, genomic organization, expression, regulation, and
evolution of retrotransposons, and discusses both their contributions to plant
genome evolution and their use as genetic tools in plant biology.
PMID- 10690417
TI - Mammalian DNA mismatch repair.
AB - DNA mismatch repair (MMR) is one of multiple replication, repair, and
recombination processes that are required to maintain genomic stability in
prokaryotes and eukaryotes. In the wake of the discoveries that hereditary
nonpolyposis colorectal cancer (HNPCC) and other human cancers are associated
with mutations in MMR genes, intensive efforts are under way to elucidate the
biochemical functions of mammalian MutS and MutL homologs, and the consequences
of defects in these genes. Genetic studies in cultured mammalian cells and mice
are proving to be instrumental in defining the relationship between the functions
of MMR in mutation and tumor avoidance. Furthermore, these approaches have raised
awareness that MMR homologs contribute to DNA damage surveillance, transcription
coupled repair, and recombinogenic and meiotic processes.
PMID- 10690418
TI - Family values in the age of genomics: comparative analyses of temperate
bacteriophage HK022.
AB - HK022 is a temperate coliphage related to phage lambda. Its chromosome has been
completely sequenced, and several aspects of its life cycle have been intensively
studied. In the overall arrangement, expression, and function of most of its
genes, HK022 broadly resembles lambda and other members of the lambda family.
Upon closer view, significant differences emerge. The differences reveal
alternative strategies used by related phages to cope with similar problems and
illuminate previously unknown regulatory and structural motifs. HK022 prophages
protect lysogens from superinfection by producing a sequence-specific RNA binding
protein that prematurely terminates nascent transcripts of infecting phage. It
uses a novel RNA-based mechanism to antiterminate its own early transcription.
The HK022 protein shell is strengthened by a complex pattern of covalent subunit
interlinking to form a unitary structure that resembles chain-mail armour. Its
integrase and repressor proteins are similar to those of lambda, but the
differences provide insights into the evolution of biological specificity and the
elements needed for construction of a stable genetic switch.
PMID- 10690419
TI - Meiotic chromosomes: integrating structure and function.
AB - Meiotic chromosomes have been studied for many years, in part because of the
fundamental life processes they represent, but also because meiosis involves the
formation of homolog pairs, a feature which greatly facilitates the study of
chromosome behavior. The complex events involved in homolog juxtaposition
necessitate prolongation of prophase, thus permitting resolution of events that
are temporally compressed in the mitotic cycle. Furthermore, once homologs are
paired, the chromosomes are connected by a specific structure: the synaptonemal
complex. Finally, interaction of homologs includes recombination at the DNA
level, which is intimately linked to structural features of the chromosomes. In
consequence, recombination-related events report on diverse aspects of chromosome
morphogenesis, notably relationships between sisters, development of axial
structure, and variations in chromatin status. The current article reviews recent
information on these topics in an historical context. This juxtaposition has
suggested new relationships between structure and function. Additional issues
were addressed in a previous chapter (551).
PMID- 10690420
TI - [Pathogen microevolution in the course of an infectious process].
PMID- 10690421
TI - [Inhibition of the reproduction of strains of the herpes simplex virus type 1
with drug resistance].
AB - Inhibition of type-1 herpes simplex strains resistant to acyclovir,
phosphonoacetic acid and their combination by combined use of three drugs with
different mechanisms of action capable of suppressing reproduction of the
acyclovir resistant strain was studied. The combinations used were the following:
Ara-A + ribavirin + phosphonoformic acid, Xylo-A + ribavirin + phosphonoformic
acid and Ph-ACH + Ara-A + ribavirin. The former two combinations had a
synergistic action on the standard strain L2 whose drug susceptibility had not
undergone changes as well as on the acyclovir resistant strain. As for the strain
resistant to phosphonoacetic acid and to acyclovir + phosphonoacetic acid the
effect was additive. Ph-ACH + Ara-A + ribavirin had a marked synergistic action
on all the strains tested.
PMID- 10690422
TI - [The effect of heat shock on the growth and mycelial morphology of Streptomyces
chrysomallus].
AB - The effect of various conditions of heat shock (1 hour at 35, 38, 40, 42, 45 and
50 degrees C) on the growth and morphological features of Streptomyces
chrysomallus, an organism producing actinomycin, was studied. A definite
regularity in the mycelium morphological changes at high temperatures was
observed. After the shock at 35 and 38 degrees C the biomass volume and
morphological features of the streptomycete did not markedly differ from those in
the control. The shock at 40 degrees C induced the growth inhibition with
decreasing the biomass volume by 50 per cent and appearance of submerged spores.
When the shock conditions were more rigid (42, 45 and 50 degrees C) the mycelium
growth lacked. It is of interest that the temperature of 42 degrees C induced
abundant formation of the spores. With further increasing of the temperature to
45 and 50 degrees C the spore formation was not so abundant. The changes in the
growth and development of the streptomycete are discussed in relation to the
molecular mechanism of the cell protection from temperature shock.
PMID- 10690423
TI - [The in-vitro effect of the leukocytic cationic protein preparation Intercide on
Escherichia coli].
AB - Intercide is a cationic protein with the molecular weight of 11.0-11.5 kD from
human leukocytes. The in vitro effect of its different concentrations (0.6 to 1.8
mg/ml) on populations of Escherichia coli M17 and K12 and 120 E.coli isolates
from various sources such as water, feces of healthy humans and patients with
extraintestinal escherichiosis was studied. The experiments with the bacterial
suspensions and broth cultures demonstrated that Intercide had an antibacterial
action on both the stationary and growing cells. However, some strains of E.coli
were resistant to the lethal effect of Intercide. It was observed for the first
time that in a concentration of 1.8 mg/ml Intercide was able to stimulate the
biomass growth of some E.coli strains in broth culture. The factor analysis
showed that the Intercide stimulating effect was more often evident with respect
to extraintestinal escherichiosis pathogens with high anti-Intercide and
antilysozyme activities.
PMID- 10690424
TI - [A comparative analysis of the properties of bacteria in the genus Salmonella
isolated from children in Latvia].
AB - Since social and economic changes in Latvia in 1991 the incidence of
salmonellosis dramatically increased: more than 500 pediatric cases are
registered every year. Specification of the properties of the Salmonella strains
isolated in Latvia was undertaken. The study demonstrated that acute
salmonellosis in pediatric inpatients was mainly due to S.typhimurium (78 per
cent) and only in 22 per cent of the patients it was due to S.enteritidis. All
the S.typhimurium isolates showed high antibiotic resistance defined by specific
extended spectrum beta-lactamase (CTX-M-5).
PMID- 10690425
TI - [New natural immunosuppressants. A comparison by their mechanism of action with
cyclosporin A].
PMID- 10690426
TI - [The current approaches to enhancing the efficacy of antitumor chemotherapy by
individual treatment optimization and the selective decrease in the toxic side
effects of cytostatics].
PMID- 10690427
TI - [A broad-spectrum antimicrobial preparation--lomefloxacin (Maxaquin): the results
of 10 years of its use in the clinics of Russia].
PMID- 10690428
TI - Comparison of biochemical polymorphisms and short tandem repeat (STR) DNA markers
for paternity testing in rhesus monkeys (Macaca mulatta).
AB - Genetic markers are indispensable for molecular and statistical genetic research
involving nonhuman primates. Genetic markers must be used to ascertain parentage
and to confirm the accuracy of pedigrees based solely on housing or demographic
records; otherwise, the results of pedigree, linkage, or quantitative genetic
analyses may be unreliable. Until recently, most genetic markers used in nonhuman
primates were plasma proteins or isozyme polymorphisms, which were required in
large numbers, because levels of genetic variation revealed by these markers were
rather low. We compared the newer, PCR-amplified short tandem repeat markers
(STRs) with a panel of classical biochemical polymorphic markers, for paternity
determination among captive-bred rhesus monkeys. The STR markers exhibited an
average genetic diversity of 64% and an expected paternity exclusion probability
of 0.443. Both of these were greater than the average 54.5% genetic diversity and
0.298 exclusion probability exhibited by the biochemical markers. The STRs were
much more efficient than the biochemical markers for parentage determination,
since they required only half the amount of genetic typing data to resolve an
average paternity case. Thus, the results of applying these two classes of
genetic markers in paternity tests were somewhat different than expected on the
basis of theoretical exclusion probabilities. These differences were probably due
to inbreeding and other genetic differences among breeding colonies. Because they
are more informative and provide rapid and efficient genetic data, STRs are now
the method of choice for parentage determination and pedigree corroboration among
nonhuman primates.
PMID- 10690429
TI - Mitochondrial genetic variation in Chinese pigs and wild boars.
AB - The mitochondrial DNAs (mtDNAs) from 30 pig breeds (29 Chinese native breeds and
1 European breed) and wild boars were investigated for restriction fragment
length polymorphisms (RFLPs) to determine the phylogenetic relationships and
genetic diversity among pig breeds and wild boars. Of the 24 enzymes used, 8
(AvaI, BclI, BglII, EcoRI, EcoRV, ScaI, StuI, and XbaI) detected polymorphisms.
By combining the cleavage patterns for each enzyme, 108 individuals were sorted
into eight mtDNA mitotypes. There are two haplotype lineages in domestic pigs,
i.e., Chinese and European lineages. The pairwise nucleotide sequence divergence
was calculated to be 0.56% between Chinese pigs and European pigs, suggesting
that they might have diverged from a common ancestor approximately 280,000 years
ago. The wild boars showed more extensive genetic variation, four mitotypes were
detected in six wild boars. In addition, one of the Zhejiang wild boars was found
to share the same mitotype with Chinese native pigs. A UPGMA tree based on
genetic distance among mitotypes indicated that mtDNAs of Chinese pigs and
European pigs are clearly divided into two clusters, and Chinese wild boars are
more closely related to the Chinese pigs. Our results provide molecular evidence
to support the previous hypothesis that pigs may be derived from two maternal
origins, Asian and European wild boars. Chinese native pig breeds may have a
single origin.
PMID- 10690430
TI - Is the difference in alpha-amylase activity in the strains of Drosophila
melanogaster with different allozymes due to transcriptional or
posttranscriptional control?
AB - The alpha-amylase in Drosophila melanogaster is a highly polymorphic enzyme, at
both the allozyme level and the specific activity level. This enzyme changes its
specific activity drastically depending on both food conditions and developmental
stages, and it has been suggested that the ability to change its activity
depending on the source of food has positive correlation with fitness. But the
cause of the difference of specific activity among strains and food compositions
is not known. In order to investigate the cause of these differences, we measured
both the specific activity of amylase and the relative amount of Amy mRNA in
eight strains of D. melanogaster with different electromorphs, in two food
environments and two developmental stages. We found the following. First, the
food-dependent activity change is regulated at the transcription level. Second,
there was a significant correlation between specific activity and mRNA level
among strains. So 80 to 90% of the specific activity difference can be explained
by differences in the level of mRNAs, but the remaining part cannot. Finally,
there were significant differences in specific activity per mRNA both among
strains and between developmental stages. This suggests that there are
differences in the catalytic efficiency of each allozyme, strain- or stage
specific translation rate, enzyme stability, or differential use of two Amy loci.
PMID- 10690431
TI - Apolipoprotein E polymorphism and plasma lipid levels in Native Mongolian sheep.
AB - Apolipoprotein E (apoE) phenotypes were determined in 199 unrelated native sheep
(Khalkhas line) of Central Mongolia, using a polyacrylamide gel isoelectric
focusing-immunoblotting technique, and the plasma lipid levels in different
phenotypes were assayed enzymatically. Twenty-eight phenotypes were identified in
this sheep. In addition to all the previously detected seven apoE variants
composing the phenotypes, four new variants were discovered, which were called
E8, E9, E10, and E11. From the population data, these were found to be
genetically controlled by four codominant alleles, designated APOE8, APOE9,
APOE10, and APOE11, based on the same mode of inheritance as in the seven
variants. These alleles were detected at a low frequency, in the range of 0.005
to 0.0126. The Khalkhas sheep differed most significantly from the Baruwal and
Lampuchhre sheep of Nepal and the Vietnamese sheep with respect to the allele
frequencies found in some Asian local sheep previously examined. Type 1/1 and/or
2/7 sheep had significantly higher plasma levels of total cholesterol and low
density lipoprotein cholesterol than type 7/7 sheep (P < 0.05 and/or P < 0.02).
PMID- 10690432
TI - Inheritance of isozyme variants in seed tissues of Pinus merkusii Jungh. & De
Vriese.
PMID- 10690433
TI - Career directions. Real-world guidance from successful biomedical professionals.
AB - Talking to employers and successful biomedical professionals reveals a profile of
traits in common. Successful biomedical professionals exhibit a desire to excel
and a willingness to work hard. They push beyond personal comfort zones to
identify weaknesses and build skills that may not come easily. Whether on the job
or in the classroom, they are always learning. Short-term sacrifices are endured
for the long-term payoffs provided by academic degrees and certification.
Successful biomedical professionals challenge assumptions, especially their own,
in order to advance their careers. When it comes to important career decisions,
they solicit advice and do research. Ultimately, however, the decisions they make
must be in accord with their own internal guidance systems. Career management is
important to get right. Aside from the financial security and emotional
satisfaction provided by career choices, there is the practical matter that, in a
sense, the journey lasts a lifetime.
PMID- 10690434
TI - Impact of CDMA wireless phone power output and puncture rate on hearing aid
interference levels.
AB - Interference between digital wireless phones and hearing aids occurs when the
radiofrequency bursts from the phone transmission are demodulated by the hearing
aid amplifier. The amplified interference signal is heard as a "buzz" or "static"
by the hearing aid wearer. Most research and standards development activity has
focused on worst-case scenarios with the phone operating at its maximum power.
Since this power level is often not typical in urban and suburban settings, it is
of value to determine the impact of lower power levels on the overall level of
audible interference. Using a frequency analyzer, and several hearings aids and
code division multiple access (CDMA) phones, the audio frequency spectrum of
interference was recorded for each phone-aid combination and for a range of power
levels producing from no interference to maximum interference. As phone power is
increased, the interference signal becomes distinguishable from the ambient noise
level and a linear response region is observed in which a specified increase in
power output results in a proportional increase in the overall input referenced
interference level (OIRIL). As power is increased beyond the linear region, the
hearing aid enters a saturation region where an additional power increase results
in a reduction or no increase in the OIRIL. The numeric differences in
interference documented in this study were used in conjunction with the results
of a previous study by the authors to determine the impact of reduced power on
speech intelligibility and annoyance. The amount of improvement for a given power
reduction depends on the radiofrequency immunity of the hearing aid and is
substantial for hearing aids with poor immunity. For high-immunity aids, the
level of audible interference remains low even at high phone power levels.
PMID- 10690435
TI - Evolution of the optimum bidirectional (+/- biphasic) wave for defibrillation.
AB - Introduction of the asymmetric bidirectional (+/- biphasic) current waveform has
made it possible to achieve ventricular defibrillation with less energy and
current than are needed with a unidirectional (monophasic) waveform. The
symmetrical bidirectional (sinusoidal) waveform was used for the first human
heart defibrillation. Subsequent studies employed the underdamped and overdamped
sine waves, then the trapezoidal (monophasic) wave. Studies were then undertaken
to investigate the benefit of adding a second identical and inverted wave; little
success rewarded these efforts until it was discovered that the second inverted
wave needed to be much less in amplitude to lower the threshold for
defibrillation. However, there is no physiologic theory that explains the
mechanism of action of the bidirectional wave, nor does any theory predict the
optimum amplitude and time dimensions for the second inverted wave. The authors
analyze the research that shows that the threshold defibrillation energy is
lowest when the charge in the second, inverted phase is slightly more than a
third of that in the first phase. An ion-flux, spatial-K+ summation hypothesis is
presented that shows the effect on myocardial cells of adding the second inverted
current pulse.
PMID- 10690436
TI - A software tool for fetal blood flow analysis.
AB - Doppler ultrasonography is a widely used technique for determination of the fetal
blood flow pattern. Determination of the waveform qualities was done manually,
with considerable inter- and intraobserver variations. In order to limit the
variations and the time-consuming data entry, a Fetal Blood Flow Analysis
software program was developed to facilitate ease of determination of Doppler
signals. This article describes the development and unique features of the
software program, made specifically to meet the obstetric and gynecology
department's needs.
PMID- 10690437
TI - Leadership and personality types.
PMID- 10690438
TI - Internet addressing schemes.
PMID- 10690439
TI - Mutual recognition agreements and what they mean to industry and regulatory
bodies.
PMID- 10690440
TI - Exercise in cardiac rehabilitation.
PMID- 10690441
TI - The stigmatisation and denial of mental illness in athletes.
PMID- 10690442
TI - Exercise and the prevention of back pain disability.
PMID- 10690443
TI - The social patterning of exercise behaviours: the role of personal and local
resources.
PMID- 10690444
TI - Exercise in preventing falls and fall related injuries in older people: a review
of randomised controlled trials.
AB - OBJECTIVE: To assess the effectiveness of exercise programmes in preventing falls
(and/or lowering the risk of falls and fall related injuries) in older people.
DESIGN: A review of controlled clinical trials designed with the aim of lowering
the risk of falling and/or fall injuries through an exercise only intervention or
an intervention that included an exercise component. MAIN OUTCOME MEASURES:
Falls, fall related injuries, time between falls, costs, cost effectiveness.
SUBJECTS: A total of 4933 men and women aged 60 years and older. RESULTS: Eleven
trials meeting the criteria for inclusion were reviewed. Eight of these trials
had separate exercise interventions, and three used interventions with an
exercise programme component. Five trials showed a significant reduction in the
rate of falls or the risk of falling in the intervention group. CONCLUSIONS:
Exercise is effective in lowering falls risk in selected groups and should form
part of falls prevention programmes. Lowering fall related injuries will reduce
health care costs but there is little available information on the costs
associated with programme replication or the cost effectiveness of exercise
programmes aimed at preventing falls in older people.
PMID- 10690445
TI - Effects of one year of resistance training on the relation between muscular
strength and bone density in elderly women.
AB - OBJECTIVES: There is a paucity of long term studies on exercise training in
elderly women. The purpose of this study was to investigate the effects of one
year of progressive resistance exercise (PRE) on dynamic muscular strength and
the relations to bone mineral density (BMD) in elderly women. METHODS: Forty four
healthy sedentary women (mean age 68.8 years) volunteered for this study and were
randomly assigned to either an exercise group or a control group. The exercise
group were involved in three one hour sessions a week for 52 weeks of supervised
PRE to strengthen the large muscle groups of the body, while the control group
were instructed to continue their normal lifestyle. The exercise circuit included
three sets of eight repetitions at 75% of one repetition maximum focused on the
large muscle groups. BMD was measured by dual energy x ray absoptiometry (Lunar
DPX) at the lumbar spine and at three sites in the proximal femur. Other selected
parameters of physical fitness were also measured. RESULTS: Statistical analyses
(analysis of covariance) showed significant strength gains (p < 0.01) in
bilateral bench press (> 29%), bilateral leg press (> 19%), and unilateral biceps
curl (> 20%). No significant difference between groups was evident in body
weight, grip strength, flexibility, waist to hip ratio, or the sum of eight
skinfolds. Significant relations (p < 0.05) were recorded between dynamic leg
strength and the BMD of the femoral neck, Ward's triangle, and the lumbar spine.
CONCLUSIONS: Significant strength changes, after one year of PRE, were evident in
elderly women, and the muscle increases may parallel changes in BMD; however,
correlation coefficients were moderate.
PMID- 10690446
TI - Neutrophil function response to aerobic and anaerobic exercise in female judoka
and untrained subjects.
AB - OBJECTIVES: Recent studies have indicated reduced immunity in trained athletes.
AIM: To assess the effects of aerobic and anaerobic exercise on the phagocytic
process in 18-26 year old trained female judoka (n = 8) and untrained controls (n
= 7). METHODS: Each subject participated randomly in two different testing
sessions (aerobic, 20 minutes of treadmill running at 70-80% of maximal heart
rate; anaerobic, Wingate anaerobic test). Venous blood samples were drawn before,
immediately after, and 24 hours after each session. RESULTS: There were no
significant differences in basal values of net chemotaxis (chemotaxis--random
migration), bactericidal activity, and superoxide anion release between the
judoka and the untrained women. There was a significant decrease in net
chemotaxis 24 hours after the aerobic exercise in both the judoka (from 64 (19)
to 39 (13) cells/field, p < 0.02) and the untrained controls (from 60 (7) to 47
(12) cells/field, p < 0.05). Bactericidal activity and superoxide anion release
did not change significantly after aerobic exercise in either group. There were
no significant changes in net chemotaxis, bactericidal activity, and superoxide
anion release after anaerobic exercise in either the judoka or untrained women.
CONCLUSIONS: The decrease in net chemotaxis after aerobic, but not after
anaerobic, exercise, suggests that net chemotaxis is affected by the combination
of exercise intensity and duration, and not by the exercise intensity itself.
Similar effects of both exercise sessions in the judoka and the untrained women
suggest that training had no effect on neutrophil function response to aerobic
and anaerobic exercises.
PMID- 10690447
TI - Balance control, flexibility, and cardiorespiratory fitness among older Tai Chi
practitioners.
AB - BACKGROUND: Tai Chi Chuan (TTC) exercise has beneficial effects on the components
of physical condition and can produce a substantial reduction in the risk of
multiple falls. Previous studies have shown that short term TCC exercise did not
improve the scores in the single leg stance test with eyes closed and the sit and
reach test. There has apparently been no research into the effects of TCC on
total body rotation flexibility and heart rate responses at rest and after a
three minute step test. METHODS: In this cross sectional study, 28 male TCC
practitioners with an average age of 67.5 years old and 13.2 years of TCC
exercise experience were recruited to form the TCC group. Another 30 sedentary
men aged 66.2 were selected to serve as the control group. Measurements included
resting heart rate, left and right single leg stance with eyes closed, modified
sit and reach test, total body rotation test (left and right), and a three minute
step test. RESULTS: Compared with the sedentary group, the TCC group had
significantly better scores in resting heart rate, three minute step test heart
rate, modified sit and reach, total body rotation test on both right and left
side (p < 0.01), and both right and left leg standing with eyes closed (p <
0.05). According to the American Fitness Standards, the TCC group attained the
90th percentile rank for sit and reach and total body rotation test, right and
left. CONCLUSION: Long term regular TCC exercise has favourable effects on the
promotion of balance control, flexibility, and cardiovascular fitness in older
adults.
PMID- 10690448
TI - A comparison of lactate concentration in plasma collected from the toe, ear, and
fingertip after a simulated rowing exercise.
AB - OBJECTIVE: To examine the validity of using blood taken from the toe for the
assessment of plasma lactate concentration in rowers. To achieve this, values
were compared with those taken from the fingertip and earlobe. METHODS: Nine
subjects exercised at two separate submaximum workloads on the Concept II rowing
ergometer. The loads, each lasting four minutes, elicited mean (SD) heart rate
responses of 160.1 (8.5) and 180.1 (5.7) beats/min, which corresponded to 76.4
(6.1)% and 91.9 (4.7)% of the estimated heart rate maximum of the subjects. Blood
was simultaneously removed after the cessation of exercise by three experimenters
and was analysed for plasma lactate concentration. RESULTS: At 76.4% of estimated
heart rate maximum, the mean (SD) plasma lactate concentrations sampled from the
fingertip, toe, and earlobe were 6.36 (1.58), 5.81 (1.11), and 5.29 (1.24) mmol/l
respectively. At 91.9% of estimated heart rate maximum, respective values were
8.81 (2.30), 8.53 (1.37), and 8.41 (2.35) mmol/l. No significant differences (p >
0.05) were found between any of the sites at either work intensity. CONCLUSIONS:
The toe may offer a practical alternative for assessing the concentration of
lactate during rowing, having the advantage that repeated blood samples can be
removed without interruption of the rowing action.
PMID- 10690449
TI - Isokinetic performance and shoulder mobility in elite volleyball athletes from
the United Kingdom.
AB - OBJECTIVES: To evaluate the differences in strength and mobility of shoulder
rotator muscles in the dominant and non-dominant shoulders of elite volleyball
players. METHODS: Isokinetic muscle strength tests were performed at speeds of 60
and 120 degrees/s, and shoulder mobility was examined in ten players from the
England national men's volleyball squad. The subjects also completed a
questionnaire that included a visual prompt and analogue pain scale. RESULTS: The
range of motion of internal rotation on the dominant side was less than that on
the non-dominant side (p < 0.01). The average peak strength at 60 degrees/s
external eccentric contraction was lower than that of internal concentric
contraction in the dominant arm, but was higher in the non-dominant arm. Six of
the ten subjects reported a shoulder problem, described as a diffuse pain located
laterally on the dominant shoulder. CONCLUSIONS: These elite volleyball players
had a lower range of motion (internal rotation) and relative muscle imbalance in
the dominant compared with the non-dominant shoulder.
PMID- 10690450
TI - Factors associated with hip joint rotation in former elite athletes.
AB - OBJECTIVES: To study factors associated with passive hip rotation range of motion
(ROM) in former elite male athletes. METHODS: Athletes were interviewed about hip
pain, disability, lifetime occupational loading, and athletic training. The
passive hip rotation was measured with a Myrin inclinometer in 117 former elite
male long distance runners, soccer players, weight lifters, and shooters aged 45
68 years. Magnetic resonance imaging was used to detect hip osteoarthritis.
RESULTS: There were no differences in passive hip rotation ROM between the four
athlete groups nor between diverging lifetime loading patterns associated with
occupational or athletic activities. Among the subjects without hip
osteoarthritis, hip pain, and hip disability according to a stepwise linear
regression analysis, the only factor that was associated with the passive hip
rotation ROM was body mass index (BMI), explaining about 21% of its variation.
Subjects with high BMI had lower passive hip rotation ROM than those with low
BMI. There was no right-left difference in the mean passive hip rotation ROM in
subjects either with or without hip osteoarthritis as determined by magnetic
resonance imaging. Nevertheless, hip rotation ROM was clearly reduced in a few
hips with severe caput deformity. CONCLUSIONS: Long term loading appears to have
no association with passive hip rotation ROM. On the other hand, the hip rotation
value was lower in subjects with high BMI than in those with low BMI. A clear
right-left difference in hip rotation was found only in those subjects who,
according to our magnetic resonance imaging criteria, had severe hip
osteoarthritis. These findings should be taken into account when hip rotation ROM
is used in the clinical assessment of hip joints.
PMID- 10690451
TI - Correlation of bone scintigraphy and histological findings in medial tibial
syndrome.
AB - OBJECTIVE: To correlate bone scintigraphy and histopathological findings in
patients with medial tibial syndrome. METHODS: Twenty patients (32 limbs) with a
clinical diagnosis of medial tibial syndrome had surgery. Bone scintigraphy
before the operation was compared with the histological appearance of bone and
periosteal specimens obtained at surgery. RESULTS: Delayed bone scintigraphy
showed normal appearance in 11 limbs, characteristic diffuse tubular pattern
uptake in 16 limbs, and focal uptake in five. Periosteal histology disclosed
fibrous thickening as the most common finding associated with increased
vascularity, occasionally with chronic inflammatory cell infiltration,
haemosiderin, and acid mucopolysaccharide deposition. Loss of osteocytes was the
main finding of bone histology associated with some enlargement of lacunae and
lamellar structure disruption. A grading system was used to score normal and
abnormal histological appearance. For analysis the findings were regrouped to
provide tables using Fisher's exact test. There was no correlation between bone
scintigraphy and the histology of bone and periosteum, but two interesting
observations were noted. Those cases with periosteal thickening had mostly normal
bone scan appearance (p = 0.0028). Those cases with low levels of osteocyte loss
had mostly abnormal bone scintigraphy. CONCLUSION: Abnormal histological
appearance of bone and periosteum is a feature of medial tibial syndrome. These
histological findings show poor correlation with bone scintigraphy. The exact
pathogenesis of this syndrome remains unclear.
PMID- 10690452
TI - Sport related proximal femoral fractures: a retrospective review of 31 cases
treated in an eight year period.
AB - In an eight year period, 31 patients with proximal femoral fractures resulting
from sports accidents were treated by implantation of either a Gamma nail or a
dynamic hip screw. Return to work or sports and the time to bone healing did not
differ very much between the treatments. Gamma nailing was clearly the best with
regard to stability and time to full mobilisation (4.5 days), but required 39
minutes to perform compared with insertion of a dynamic hip screw (27 minutes).
The incidence of complications and malalignments did not differ very much between
the two, although, when Gamma nailing was first used in the authors' clinic, more
intraoperative complications occurred than with the dynamic hip screw. Stable
pertrochanteric fractures may be treated with a dynamic hip screw. Unstable
pertrochanteric or subtrochanteric fractures are treated with a Gamma nail at the
authors' institution.
PMID- 10690453
TI - Stages in the development of a research project: putting the idea together.
AB - We have considered some of the most important factors involved in designing a
viable study that will adequately address the research question. Although we do
not profess to be experts in all aspects of the above, we have learned through
experience that attention to many of the above points will help to avoid
frustration during the experimental process and when the study is presented for
external review and subsequent presentation and publication. Good luck in your
research.
PMID- 10690454
TI - Giant retinal tears resulting from eye gouging in rugby football.
AB - A 29 year old myopic man sustained two separate giant retinal tears in his right
eye following deliberate eye gouging during a rugby tackle. These were
successfully repaired by vitrectomy and intraocular silicone oil injection.
Although the postoperative course was complicated by pupil block glaucoma, he
regained corrected visual acuity of 6/5 after oil removal. This injury highlights
the potentially sight threatening nature of this type of rugby injury and the
importance of early referral for specialist treatment.
PMID- 10690455
TI - Redefining the overtraining syndrome as the unexplained underperformance
syndrome.
PMID- 10690456
TI - Upper airways obstruction.
PMID- 10690457
TI - Use of imaging data for predicting clinical outcome.
PMID- 10690458
TI - What is sports medicine? Medical students don't know.
PMID- 10690459
TI - [Gertrude Belle Elion (1918-1999): brilliant chemist, discoverer of modern
antivirals and Nobel Prize for medicine].
PMID- 10690460
TI - [Bacterial meningitis in the adult. Study of 85 cases observed in the infectious
disease unit of the Fondation Jeanne Ebori (F.J.E.), Libreville, Gabon].
AB - We conducted a retrospective review to specify the frequency, identify the
aetiological factors of bacterial meningitis in adults (BMA) and to evaluate the
therapeutic protocol used. This study was conducted on 85 (BMA) cases of
hospitalised patients between January 1991 and December 1995 (5 years) on our
service. The BMA represented 3% of all admissions for infectious diseases at the
Foundation Jeanne Ebori in Libreville. It occurred in an endemosporadic fashion.
All patients were Black Africans with an average age of 33 years (range: 16-60
years). Males predominated by a ratio of 2.4. Tha patients were seen late in the
evolution of the disease, as shown by the folloxing clinical signs: neuropsychic
problems (100%), 25 patients (29%) were in a profound coma, 5 (6%) had a
hemiplegia, 2 (2%) an hypoacousie and 1 (1%) seizure. Aetiological factors were
found in 17 cases (20%) to be in the ORL sphere (sinusitis: n = 8, ear infection:
n = 4), pneumopathies (n = 4) and one case of breach dure-mere. The predominant
germ was pneumocoque, isolated in 55 cases (65%), 15 cases had a LCR clear (18%).
Bacteria gram negative (6%) were identified in the immunocompromised HIV. Third
generation cephems had an efficiency higher than beta lactamines: 83% against
73%. The mortality was 18%; 3% of the remaining patients had neurological
deafness. The seriousness of the results of this survey calls for the urgent
implementation of a surveillance programme.
PMID- 10690461
TI - [Genotypic diversity of Mycobacterium tuberculosis in the Guiana-Antilles
region].
AB - This investigation dealt with 226 strains (1 isolate/patient) of Mycobacterium
tuberculosis isolated in the French West Indies and French Guiana over a three
year period (1994-1996). The genotypic diversity of the isolates was investigated
using various molecular markers; essentially two PCR-based rapid methods, namely
spoligotyping and double-repetitive-element (DRE)-PCR, as well as three
restriction fragment length polymorphism (RFLP)-based methods, namely IS6110
RFLP, DR-RFLP and PGRS-RFLP. Out of 226 isolates investigated, a total of 166
isolates were distributed in 31 spoligotype-defined clusters containing 2-31
strains, which corresponded to a rate of 73% of primary clustering. After
secondary typing with DRE-PCR, IS6110-RFLP, DR-RFLP and/or PGRS-RFLP, molecular
clonality was established for 73 isolates organised in 25 clusters (32% of
clustered isolates). Considering one reactivation case per cluster, the rate of
recent transmission was estimated to a minimal rate of 21%, however the available
epidemiologic information led to the positive conclusion for only 14% of cases.
The data obtained demonstrated the presence of common genotypes of M.
tuberculosis among the three overseas French territories, i.e. Guadeloupe,
Martinique and French Guiana. The results obtained during this retrospective
study clearly indicate the importance of future prospective epidemiological
investigations around the clustered cases of tuberculosis, so as to detect the
persisting foci of endemic disease and characterize the chain of transmission as
well as the subpopulations which are at an increased risk of contracting and/or
propagating the disease. Last but not least, the present study also deals with a
first phylogenetic approach of M. tuberculosis based on a comparison of the
spoligotyping results obtained locally with those reported elsewhere in the
world.
PMID- 10690462
TI - [Dientamoeba fragilis: pathogenic flagellate?].
AB - INTRODUCTION: D. fragilis is an intestinal protozoa whose pathogenic
characteristics are increasingly recognized. The aim of this study is to specify
the epidemiologic, biological and clinical aspects of this protozoa. MATERIAL
USED AND METHODOLOGY: Survey conducted on 27,058 parasitological test of stools
in parasitology-mycology laboratory of the Sfax University Hospital over a period
of 5 years. RESULTS: 11,254 parasitological test of stools were positive (41.6%)
of which 89.3% comprised protozoa. D. fragilis was found in 1497 cases (13.3% of
the positive cases). In 65% of these cases, it was associated with other
intestinal parasites in particular Blastocystis hominis (40.3%), Endolimax nanus
(24%), Entamoeba coli (6%), Giardia intestinalis (5.7%) and Enterobius
vermicularis (5%). Those patients having a parasitism with isolated D. fragilis
were predominantly female and young subjects (< 20 years). Clinical signs
included abdominal pain (88.5%), anorexia (50%), alternating diarrhoea and
constipation (40.4%) and diarrhoea (21%) with mucus in 7.6%. DISCUSSION: D.
fragilis is today classified in the group of flagellates and we share the opinion
of the majority of the authors as to its real pathogenic capacity.
PMID- 10690463
TI - [Ecology of Lymnaea truncatula Muller, intermediate host of Fasciola hepatica
Linne in the microclimate of Tozeur (southeast of Tunisia)].
AB - Systematic visits were carried out in the traditional Tozeur' oasis (Tunisia), in
1997/1998 in order to study the ecology of Lymnaea truncatula as well as its
density in relation to habitat characteristics in the hydrographical networks of
the oases. Lymnaea truncatula was enumerated on 1 m2 surface by habitat,
according to the quadrat method. Samples of soil, irrigation and draining water
were also analysed. The density of Lymnaea truncatula detected in autumn was
constantly higher. It depends on the nature of the habitat: 54.8% in the
secondary irrigation canals, 34.8% in those of draining, 7.6% in the seguia and
2.9% in the principal draining canal. Ecological factors--permanent dampness,
suitable luminosity, basic pH of soil and water, temperature between 10 and 28
degrees C--contribute to the multiplicity of snails.
PMID- 10690464
TI - [Human dirofilariasis in Corsica: a new local case. Review of reported cases].
AB - A case of human dirofilariasis with Dirofilaria (Nochtiella) repens, located in a
subcutaneous nodule of the arch of the foot is reported in a 64-year-old man
living in the surroundings of Porto Vecchio in Corsica. The histological
examination of this nodule has revealed a gravid female nematode, dead some weeks
or months before its surgical excision. It is the second case of human
dirofilariasis observed in a patient living on the island. The authors are
surprised by the number of patients reported in medical literature (10
altogether) as having contracted the infection probably during a short stay in
Corsica. This paper seeks to collect the fragmented available data on the
existence in Corsica of nematodes in dogs and its possible vectors.
PMID- 10690465
TI - [Malaria transmission in an area of future vaccination in equatorial forest of
south Cameroon].
AB - In order to describe malaria transmission in a future antigamete vaccine trial
area, a longitudinal entomological study was conducted, together with
parasitological and immunological surveys, from June 1997 to May 1998 in two
nearby villages in a tropical rain forest area 100 km east of Yaounde. Koundou is
located along the main road in an open and degraded environment combining
cultivated lands and forests; Ebolakounou is located 5 km from the road in forest
surroundings. Indoor mosquito night catches no human volunteers were performed
twice a month, in ten houses. We determined the entomological infection rate as
176 infected bites per human per year in Koundou (47.7% for An. moucheti, 47.3%
for An. gambiae and 5% for An. funestus) and only 17.7 infected bites/human/year
in Ebolakounou, with An. gambiae only. Transmission appears to be ten times
higher in the village situated in a degraded environment than in the village
situated in the rainforest.
PMID- 10690466
TI - [Variability of in vitro activity of proguanil and cycloguanil on erythrocyte
stages of Plasmodium falciparum as a function of culture conditions].
AB - The in vitro activity of proguanil, cycloguanil (active metabolite of proguanil),
pyrimethamine, and chloroquine was determined for 14 isolates of Plasmodium
falciparum and the chloroquine-resistant W2 clone. In vitro assays were performed
by using different types of RPMI 1640 culture medium and incubation period. The
use of the standard RPMI medium or RPMI medium containing low concentrations of
folate and para-aminobenzoic acid increases the 50% inhibitory concentrations of
cycloguanil and pyrimethamine, as compared with the use of folate- and para
aminobenzoic acid-free RPMI medium. The concentrations of folate and para
aminobenzoic acid did not affect the in vitro activity of proguanil and
chloroquine. However, prolongation of the incubation period from 42 to 66 hours
decreased the 50% inhibitory concentrations of all test compounds. The weak
antagonism in vitro between chloroquine and proguanil or cycloguanil does not
seem to have any repercussion on the in vivo efficacy of chloroquine-proguanil
combination.
PMID- 10690467
TI - [Chloroquine sensitivity of Plasmodium falciparum at the Gamkalley Clinic and the
Nigerian armed forces PMI (Niamey, Niger)].
AB - In vivo tests for Plasmodium falciparum were carried out in 1998 during the rainy
season among children in Niamey, in the Republic of Niger. Chloroquine was
prescribed at 25 mg/kg for 3 days in febrile patients with uncomplicated P.
falciparum malaria. Forty-five 1-5 year-olds and thirty-three 6-15 year-olds were
included in the study. A group of 53 adult patients was also surveyed to evaluate
the efficacy of chloroquine in semi-immune persons. Body temperature and blood
smears including parasitemia were recorded on days 0, 3, 7 and 14. Less than 10%
of the patients were delinquent. Around 75% of the patients were successfully
treated in the 1-5 year-olds and 6-15 year old age groups. Relapses were observed
in 20% of the 1-5 year-olds (early relapses 8.9%, late relapses 11.1%) and in
16.7% in the 1-15 year-olds (early relapses 6.4%, late relapses 10.3%). Among
adults, successful treatment was obtained in 86.8% of the cases and early and
late relapses were respectively observed in 3.8% and 1.9% of the cases. All the
patients with malaria relapses were cured with second-line treatments
(pyrimethamine-sulfadoxine or quinine). According to these results, chloroquine
resistance appears to be moderate in Niamey. Therefore chloroquine should remain
the first line treatment of uncomplicated P. falciparum malaria in this
population.
PMID- 10690468
TI - [Sleeping sickness in children at Bobo-Dioulasso Hospital Center: apropos of 3
cases].
AB - The authors report three observations of trypanosomiasis in children aged 3 to 13
years from Ivory Coast and Burkina Faso. Two cases were imported from Cote
d'Ivoire and one originated from an old endemic area of Bobo-Dioulasso region in
Burkina Faso. Clinical features were comparable to classical descriptions in
adults but neurological findings were dominant. Two children were at the
lymphatic stage. Treatment with melarsoprol in two cases and eflornithine in one
case led to complete recovery. Active epidemiologic surveillance of this zoonosis
should be maintained and the devastating pandemic of the beginning of the century
should be remembered.
PMID- 10690469
TI - [Public hospitals in Sub-Saharan African countries and their perspectives].
AB - Hospitals have a very important role to play within the care system of Sub
Saharan African countries, not only because they care for patients sent by other
health services, but also because they participate in the training of health
professionals. In spite of many reforms, they are trapped in a vicious circle,
which, to be broken, means moving from too highly stratified administrative
system to a system of enterprise. This system must focus on performance, while
guaranteeing necessary public service. Such change requires adopting new methods
and ways of thinking for providing a complete health service for the patients,
that is adequate access to quality health care. This will entail hospitals being
given a free hand in their management, effective measurements of quality and
expenditure evaluation being devised and supervision by the state Health
department. By allowing hospitals to attract more affluent members of society,
they will be better able to meet their obligations towards the poor.
PMID- 10690470
TI - [University and tropical medicine].
AB - Two "tropical medicine" coexist: a "clinical tropical medicine" concerning
imported tropical diseases in North countries who is worked at clinical
departments and travellers clinics and a multidisciplinary "international
health", concerning tropical countries development, who is the concern of South
and North Institutes cooperation. International health expansion compel to
collaborate with foreign universities and institutes in and beyond the French
speaking area. The scattering of practitioners, teachers and research workers in
the midst of various French institutions and distance from field limit the
academic policy of development. Harmonizing national and European tropical
medicine teachings belong to inter-academic gathering. Programming and financing
of international health come under an inter-ministerial agency.
PMID- 10690471
TI - [Reemergence of yellow fever in West Africa: lessons from the past, advocacy for
a control program].
AB - In French speaking West Africa, yellow fever vaccine became compulsory in 1941
for the entire African and European population. From 1941 to 1960, 146 million
doses were distributed and the number of yellow fever cases declined sharply. No
case was reported from 1954 to 1960. As a result of an interruption in systematic
immunization after 1960, ten major epidemics broke out in West Africa between
1965 and 1995 (over 200,000 cases and 40,000 deaths). In 1967, the WHO programme
for eradication of smallpox was initiated and it mobilized WHO's energy and
finances. The expanded programme of immunization (EPI) was initiated in 1977 but
it did not include the yellow fever vaccine. In 1978, Primary Health Care
advocated an immunization strategy through fixed health facilities. In 1986, to
amend this strategy, WHO recommended accelerating EPI progress and instituting
National Immunization Days (NIDs). In 1990, a recommendation was made to include
the yellow fever vaccine in the EPI. In 1997, the target of global poliomyelitis
eradication by the year 2000 reinforced the NID programme and led to the use of
mobile teams. At a time when a measles eradication programme is going to take
over from the poliomyelitis programme, we must firmly advocate not omitting the
yellow fever vaccine as was the case in 1977. Indeed, in yellow fever endemic
areas, WHO recommends a simultaneous association of yellow fever and measles
vaccines for nine month-old infants. This opportunity must be seized to initiate
a yellow fever control programme.
PMID- 10690472
TI - [Protective effect of clothing impregnated with permethrin against D. reticulatus
and D. marginatus in an open biotope of central western France].
AB - During the period of major tick activity, in April and May 1998, in the Saint
Maixent l'Ecole area of Poitou, a comparative study was carried out in order to
evaluate the protective effect of garments impregnated with permethrin cis/trans
25/75. Three groups of soldiers made up respectively of 208, 218 and 427 men were
involved for 2 or 3 days in this experiment. Respectively 107, 107 and 215 wore
impregnated uniforms. Out of a total of 319 ticks, 3 were lxodes ricinus, 305
Dermacentor marginatus and 11 D. reticulatus. There was a significant difference
in both the intensity (number of ticks per individual, P < 0.0001) and prevalence
(number of individuals with ticks, P < 0.001) of ticks on individuals between
impregnated and non impregnated uniforms. The repellent effect of permethrin on
ticks was observed at the site of preferential tick attachment (normally the head
of the host for these two species of Dermacentor in France) where the number of
ticks was significantly lower in impregnated uniforms.
PMID- 10690473
TI - [Oral receptivity of Aedes aegypti formosus from Franceville (Gabon, central
Africa) for type 2 dengue virus].
AB - Dengue is widely distributed in the tropics but epidemic activity was rarely
reported in Africa before the 1980's. In the past 15 years, increased epidemic
dengue fever has been reported both in East and West Africa, raising concern
about the ability of local populations of Aedes aegypti to transmit dengue
viruses. Ae. aegypti is present in two forms in Africa: Ae. aegypti aegypti and
Ae. aegypti formosus. This latter form, much darker, was not originally a local
species but is now colonizing artificial breeding sites within cities. We have
been able to demonstrate the oral susceptibility for dengue type 2 virus of Ae.
aegypti formosus collected in Franceville, Gabon (Central Africa). However, these
mosquitoes sampled exhibited lower infection rates than those of a control colony
of Ae. aegypti aegypti originating from French Polynesia.
PMID- 10690474
TI - [Present status of an arbovirus infection: yellow fever, its natural history of
hemorrhagic fever, Rift Valley fever].
AB - In the early 20th century, when it was discovered that the yellow fever virus was
transmitted in its urban cycle by Aedes aegypti, measures of control were
introduced leading to its disappearance. Progressive neglect of the disease,
however, led to a new outbreak in 1927 during which the etiological agent was
isolated; some years later a vaccine was discovered and yellow fever disappeared
again. In the 1960s, rare cases of encephalitis were observed in young children
after vaccination and the administration of the vaccine was forbidden for
children under 10 years. Five years later, a new outbreak of yellow fever in
Diourbel, Senegal, was linked to the presence of Aedes aegypti. In the late
1970s, the idea of a selvatic cycle for yellow fever arose. Thanks to new
investigative techniques in Senegal and Cote d'Ivoire, the yellow fever virus was
isolated from the reservoir of virus and vectors. The isolated virus was
identified in monkeys and several vectors: Aedes furcifer, Aedes taylori, Aedes
luteocephalus. Most importantly, the virus was isolated in male mosquitoes. Until
recently, the only known cycle had been that of Haddow in East Africa. The virus
circulate in the canopea between monkeys and Aedes africanus. These monkeys
infect Aedes bromeliae when they come to eat in banana plantations. This cycle
does not occur in West Africa. Vertical transmission is the main method of
maintenance of the virus through the dry season. "Reservoirs of virus" are often
mentioned in medical literature, monkeys having a short viremia whereas
mosquitoes remain infected throughout their life cycle. In such a selvatic cycle,
circulation can reach very high levels and no child would be able to escape an
infecting bite and yet no clinical cases of yellow fever have been reported. The
virulence--as it affects man--of the yellow fever virus in its wild cycle is very
low. In areas where the virus can circulate in epidemic form, two types of
circulation can be distinguished. Intermediate yellow fever--a term coined to
define epidemia which do not correspond exactly to urban yellow fever. The cycle
involves men and monkeys through wild vectors as Aedes furcifer but also through
Aedes aegypti and the mortality rate is much lower than for urban epidemics. In
urban yellow fever, man is the only vertebrate host involved in the circulation
of the virus, the vector being generally Aedes aegypti. This vector maintains a
selective pressure, increasing the transmission of virus capable of producing
high viremia in man. In the selvatic cycles, two cycles can be distinguished: one
of maintenance which does not increase the quantity of virus in circulation and
one of amplification which does increase this quantity. As we shall see, it
develops into an epizootic form but also in an epidemic form in man. When the
decrease in yellow fevers across Africa is considered, it appears that all major
epidemics occur in West Africa inspite of the presence of wild cycles of the
yellow fever virus in Central and East Africa. For the rare epidemics that have
occurred there, the vector has never been Aedes aegypti. In a recent outbreak in
Kenya, the vector was Aedes bromeliae. The examination of part of the gene
encoding for envelope protein showed the presence of two geographical types
corresponding to West-Africa and Central East-Africa. Clinically speaking, yellow
fever is an haemorrhagic fever with hepatitis similar to other haemorrhagic
fevers such as Rift Valley fever. When, in 1987, an outbreak of haemorrhagic
fever occurred in southern Mauritania, for several days it was thought to be
yellow fever. Four days later, the diagnosis was corrected by isolating and
identifying the virus as that of Rift Valley fever (RVFV). RVFV causes several
pathogenic syndromes in human beings: acute febrile illness, haemorrhagic fever,
haemorrhagic fever with hepatitis, nervous syndromes or ocular disease. Mortality
rate was high for haemorrhagic fever with hepatitis, reaching 36%. (ABST
PMID- 10690475
TI - [Poland: cholera to typhus, 1831-1950].
AB - In this article devoted to Poland's direct and indirect role in the elaboration
of contemporary international health structures and to her reputation as an
epidemic reservoir of Europe, we consider how Poland came to be perceived as the
cordon sanitaire of the West. Traditionally seen as upholding Western values, in
the 19th and 20th centuries the country became increasingly associated with
"Eastern plagues"-cholera and then typhus-coming from Russia and which could
spread to the rest of Europe if Poland did not manage to contain them. When
Poland was reconstituted as a nation-state in 1918, the new country won
international recognition through her successful attempts to contain a typhus
epidemic sweeping westwards from Russia. The Polish government convened the first
European, League sponsored, health conference following the First World War. A
Polish doctor, L. RAJCHMAN, was chosen to head up the League of Nations Health
Organisation (forerunner of the WHO) and later (1946) founded UNICEF. Finally, we
examine the key issue of exanthematous typhus in both world wars, exemplifying
how a disease can come to be "ideologized", in this case by Nazi Germany. Typhus
was the pretext used- in the name of "public health"-for segregating Polish
citizens of Jewish origin and even killing them. Paradoxically, typhus was in the
process of being eradicated when the war began and German policy of mass
resettlements, sequestration, and starvation only spurred the epidemic they
supposedly wished to control.
PMID- 10690476
TI - [Filariasis in Haiti: a century of history].
AB - Wuchereria bancrofti and Mansonella ozzardi are both endemic in Haiti. Over the
last hundred years, these human parasites have been by turn investigated and
disregarded. Between 1894 and 1914, Haitian physicians encouraged by Dr. Leon
AUDAIN studied the clinical and biological impact of W. bancrofti in the numerous
infested patients in Port-au-Prince. During the American occupation (1915-1934),
the presence of M. ozzardi was recognized by a Rockefeller mission and a first
investigation of filariasis distribution in the country was carried out. Between
1935 and 1971, interest in the parasites ceased. However, many studies of W.
bancrofti and M. ozzardi and their vectors have been conducted from 1972 until
today. Lymphatic filariasis remains a great health hazard in localized leeward
foci, where climatic conditions favourise the survival of the vector Culex
quinque-fasciatus. Urban foci have been remarkably stable for the last 70 years
in northern Haiti and along the Gulf of the Gonave coast. Parasitological indices
are high and the impact on public health is great. Ozzardiasis is prevalent in
the rural coastal areas of northern and southern Haiti, where the principal
vectors Culicoides furens and C. barbosai breed in abundance. The control of
lymphatic filariasis is now possible and should be a public health priority in
Haiti.
PMID- 10690478
TI - Modern medicine. Too much of a good thing?
PMID- 10690477
TI - [Apropos of the presumed place of transmission in Haiti for a child with
conjunctival bancroftosis].
PMID- 10690479
TI - Statement concerning euthanasia and physician-assisted suicide. Ethics Committee
of the College of Family Physicians of Canada.
PMID- 10690480
TI - Viagra and broken hearts.
PMID- 10690481
TI - Where are the Canadian data?
PMID- 10690482
TI - Bosnia and Herzegovina. The challenge of change.
PMID- 10690483
TI - Role and image of family physicians. Then and now.
PMID- 10690484
TI - Managing women with nausea and vomiting of pregnancy. Canadian consensus.
AB - QUESTION: I have a 30-year-old pregnant patient who is asthmatic and is taking
prednisone. Whenever she decreases her prednisone dose, her nausea increases
tremendously even though she is taking two tablets of doxylamine and pyridoxine
combination (Diclectin) daily. She is already at 26 weeks' gestation, and I
really do not want her to continue the prednisone beyond what is needed for her
asthma, but two attempts to taper prednisone off failed because of unbearable
nausea. ANSWER: Several controlled trials show the efficacy of prednisone for
nausea and vomiting of pregnancy (NVP), but your case is fascinating in proving
the point by challenge-rechallenge. You should try to decrease the prednisone
while increasing doxylamine and pyridoxine to its recommended dose of two tablets
before sleep, one in the morning, and on in the afternoon.
PMID- 10690485
TI - Ophthaproblem. Acute angle-closure glaucoma.
PMID- 10690486
TI - Palpitations. Deadly hens teeth.
PMID- 10690487
TI - Practice tips. Endometrial biopsy.
PMID- 10690488
TI - Walking or vigorous exercise? Which best helps prevent coronary heart disease in
women?
PMID- 10690489
TI - Olanzapine. Keep an eye on this neuroleptic.
AB - Olanzapine (Zyprexa), a neuroleptic, has obtained marketing authorization for
treatment of schizophrenia. The clinical file is satisfactory, but in the absence
of relevant trials, it has not yet been demonstrated that olanzapine has a
specific activity on the positive or negative symptoms of schizophrenia. The
global efficacy of olanzapine was not substantially different from that of
haloperidol in two of the three comparative trials published to date. The only
relevant comparative trial fails to demonstrate the superiority of olanzapine
over risperidone. Olanzapine has fewer adverse neurologic effects than
haloperidol, but there is no evidence that it differs from other recent
neuroleptics in this respect. Olanzapine can have anticholinergic adverse effects
and frequently causes weight gain. Active surveillance is required because
subclinical cases of elevated transaminase levels, increased blood pressure, and
QT prolongation were observed in clinical trials (2500 patients treated).
PMID- 10690490
TI - CPR or DNR? End-of-life decision making on a family practice teaching ward.
AB - OBJECTIVE: To determine the proportion of patients on a family practice ward who
had "code status" orders and end-of-life discussions documented on their charts
in the first week of admission. To examine the correlation between a tool
predicting the likelihood of benefit from cardiopulmonary resuscitation (CPR) and
actual end-of-life decisions made by family physicians and their patients.
DESIGN: Cross-sectional descriptive study using a retrospective chart review.
SETTING: A 14-bed teaching ward where family physicians admit and manage their
own patients in an urban tertiary care teaching hospital. PARTICIPANTS: Patients
admitted to the ward for 7 or more days between December 1, 1995, and August 31,
1996. MAIN OUTCOME MEASURES: Frequency of documented "do not resuscitate" (DNR)
or "full code" orders and documented end-of-life discussions. Prognosis-after
resuscitation (PAR) score. RESULTS: In the 103 charts reviewed, code status
orders were entered within 7 days for 60 patients (58%); 31 were DNR, and 29 were
full code. Discussion of code status was documented in 25% of charts. The PAR
score for 40% of patients was higher than 5, indicating they were unlikely to
survive to discharge from hospital should they require CPR. There was a
significant association between PAR scores done retrospectively and actual code
status decisions made by attending family physicians (P < .005). CONCLUSIONS: End
of-life discussions and decisions were not fully documented in patients' charts,
even though patients were being cared for in hospital by their family physicians.
A PAR score obtained during the first week of admission could assist physicians
in discussing end-of-life orders with their patients.
PMID- 10690491
TI - Preventive care for the elderly. Do family physicians comply with recommendations
of the Canadian Task Force on Preventive Health Care?
AB - OBJECTIVE: To assess to what extent family physicians perform the maneuvers for
elderly patients recommended by the Canadian Task Force on Preventive Health Care
(CTF), and to compare physicians' performance among patients who had structured
periodic health examinations with performance among those who did not. DESIGN:
Retrospective chart audit. SETTING: Family practice unit in a secondary care,
university-affiliated hospital in Toronto, Ont. PARTICIPANTS: Records of 136
community-dwelling patients aged 70 and older. Of 340 randomly selected charts,
108 were excluded and 51 were inaccessible; 100 had had PHEs, and a random sample
of 36 who had attended the clinic three or more times was chosen from the
remaining 81 [corrected]. MAIN OUTCOME MEASURES: Proportion of patients who
received the recommended screening maneuvers. RESULTS: Charts were audited for
100 patients who had structured periodic health examinations and 36 who did not
but who attended the clinic three or more times during an 18-month period.
Screening rates among patients who had structured examinations ranged from 28% of
patients screened for hearing impairment to 100% screened for hypertension.
Patients who did not have structured examinations were significantly less likely
to receive screening maneuvers. CONCLUSIONS: Screening rates were below desirable
levels in patients older than 70 years. Screening during structured health
examinations seems to be more effective than opportunistic screening for patients
70 and older.
PMID- 10690492
TI - Sons as sole caregivers for their elderly parents. How do they cope?
AB - OBJECTIVE: To examine the experiences of men who are sole caregivers for their
elderly parents. DESIGN: Semistructured in-depth interviews. SETTING: Family
practice clinic attached to a large tertiary care centre in north central
Toronto. PARTICIPANTS: A convenience sample of 10 men who identified themselves
as sole caregivers in that they had no particular women assisting them with
caregiving. METHOD: Interviews were analyzed by standard qualitative methods.
MAIN FINDINGS: Emerging themes were the spectrum of caregiving, the experience of
caregiving, and the use of formal support systems. Scope of care varied from very
little to total care, including personal care. Participants described positive
and negative aspects of and the nature of their relationships with those for whom
they cared. Avoiding institutionalization was seen as positive; effects on work
and social life were negative. Use of more than homemaking services was
associated with previous hospitalization; participants complained about
difficulties accessing services. CONCLUSIONS: The nature of sons' relationships
with their parents and the amount of time they have available can predict how
much caregiving they can undertake. Information about community support services
is not readily accessible to these men.
PMID- 10690493
TI - Surgical treatments for Parkinson's disease.
AB - OBJECTIVE: This article reviews surgical treatments for Parkinson's disease,
emphasizing aspects pertinent to family physicians: rationale for and description
of surgeries, patient selection issues, and outcome expectations. QUALITY OF
EVIDENCE: No published series describes long-term follow up of a randomized
controlled study of any surgery for Parkinson's disease. Some reports, however,
describe thorough but brief follow up of functioning in small numbers of patients
following surgery. MEDLINE articles were identified using Parkinson's disease,
surgery, pallidotomy, thalamotomy, stimulation, grafting, and transplantation as
search words. Articles chosen for this paper described patients with systematic
follow up using accepted validated rating scales. MAIN MESSAGE: Reported series
show impressive improvements to patients undergoing lesioning, stimulation, and
grafting surgery for Parkinson's disease. These patients are typically severely
disabled but highly selected, and follow up is brief. Stereotactic lesioning
(pallidotomy and thalamotomy), deep brain stimulation (thalamic, and elsewhere)
and grafting (striatal) can be performed safely, but results vary greatly among
centres. CONCLUSIONS: Certain Parkinson's disease patients might benefit from
surgery. Ideal candidates for pallidotomy experience motor fluctuations with
disabling levodopa-induced dyskinesias. Tremors resistant to antiparkinsonian
medications sometimes respond to thalamotomy or thalamic stimulation. Other
parkinsonian syndromes, dementias, and difficulties with gait and balance respond
poorly to unilateral pallidotomy. Bilateral deep brain stimulation procedures
could benefit "midline" dysfunction.
PMID- 10690494
TI - Caregivers for people with dementia. What is the family physician's role?
AB - OBJECTIVE: To examine the role of family physicians in providing support and care
to caregivers for people with dementia. QUALITY OF EVIDENCE: Data were obtained
from Alzheimer Society guidelines, published consensus statements, and guidelines
for family physicians caring for people with dementia and their caregivers. Most
of the reported findings and recommendations are based on information from expert
consensus statements and opinion. MAIN MESSAGE: Caring for people with dementia
causes substantial psychological and physical morbidity. Services developed for
caregivers (in-home respite and individual psychological interventions) and
comprehensive support programs are helpful in relieving caregiver distress. There
is a role for family physicians in following caregivers longitudinally to assess
their physical and emotional health and coping skills, to provide information and
assistance in dealing with problems as they arise, to assist caregivers in
mobilizing family and friends, and to facilitate referrals to appropriate
services and resources. CONCLUSIONS: Family physicians have an important role in
identifying caregiver problems and providing direct and ongoing support to
caregivers in their day-to-day role.
PMID- 10690495
TI - Managing benign prostatic hyperplasia in primary care. Patient-centred approach.
AB - PROBLEM ADDRESSED: Management of benign prostatic hyperplasia (BPH) is changing
from a surgical approach to a medical approach, and the role of primary care
physicians is expanding. OBJECTIVE OF PROGRAM: To introduce a patient-centred
approach to managing BPH in primary care through a continuing medical education
(CME) program. MAIN COMPONENTS OF PROGRAM: A practice-based, small group, peer
led CME program focused on application of the International Prostate Symptom
Score and Quality of Life Assessment in four case studies on prostatism,
including BPH. At 86 workshops held across Canada, 658 physicians participated in
discussions with case materials that included videos and a handbook. A before
after practice behaviour questionnaire was administered at each workshop to
evaluate "intent to change." CONCLUSIONS: Participating physicians showed
willingness to learn new skills for patient-centred management of BPH. These
results suggest that peer-led, small group CME can successfully encourage use of
new practice guidelines in primary are and teach physicians practical steps for
developing therapeutic alliances with their patients.
PMID- 10690496
TI - Managing sexual dysfunction. Using sildenafil for patients with cardiovascular
disease. Heart and Stroke Foundation of Canada. Canadian Cardiovascular Society.
PMID- 10690497
TI - Making choices.
PMID- 10690498
TI - Hugh Davson--his contribution to the physiology of the cerebrospinal fluid and
blood-brain barrier.
PMID- 10690499
TI - Neural induction of the blood-brain barrier: still an enigma.
AB - 1. The study of the blood-brain barrier and its various realms offers a myriad of
opportunities for scientific exploration. This review focuses on two of these
areas in particular: the induction of the blood-brain barrier and the molecular
mechanisms underlying this developmental process. 2. The creation of the blood
brain barrier is considered a specific step in the differentiation of cerebral
capillary endothelial cells, resulting in a number of biochemical and functional
alterations. Although the specific endothelial properties which maintain the
homeostasis in the central nervous system necessary for neuronal function have
been well described, the inductive mechanisms which trigger blood-brain barrier
establishment in capillary endothelial cells are unknown. 3. The timetable of
blood-brain barrier formation is still a matter of debate, caused largely by the
use of varying experimental systems and by the general difficulty of
quantitatively measuring the degree of blood-brain barrier "tightness." However,
there is a general consensus that a gradual formation of the blood-brain barrier
starts shortly after intraneural neovascularization and that the neural
microenvironment (neurons and/or astrocytes) plays a key role in inducing blood
brain barrier function in capillary endothelial cells. This view stems from
numerous in vitro experiments using mostly cocultures of capillary endothelial
cells and astrocytes and assays for easily measurable blood-brain barrier
markers. In vivo, there are great difficulties in proving the inductive influence
of the neuronal environment. Also dealt with in this article are brain tumors,
the least understood in vivo systems, and the induction or noninduction of
barrier function in the newly established tumor vascularization. 4. Finally, this
review tries to elucidate the question concerning the nature of the inductive
signal eliciting blood-brain barrier formation in the cerebral microvasculature.
PMID- 10690500
TI - Barriers in the immature brain.
AB - 1. The term "blood-brain barrier" describes a range of mechanisms that control
the exchange of molecules between the internal environment of the brain and the
rest of the body. 2. The underlying morphological feature of these barriers is
the presence of tight junctions which are present between cerebral endothelial
cells and between choroid plexus epithelial cells. These junctions are present in
blood vessels in fetal brain and are effective in restricting entry of proteins
from blood into brain and cerebrospinal fluid. However, some features of the
junctions appear to mature during brain development. 3. Although proteins do not
penetrate into the extracellular space of the immature brain, they do penetrate
into cerebrospinal fluid by a mechanism that is considered in the accompanying
review (Dziegielewska et al., 2000). 4. In the immature brain there are
additional morphological barriers at the interface between cerebrospinal fluid
and brain tissue: strap junctions at the inner neuroependymal surface and these
and other intercellular membrane specializations at the outer (piaarachnoid)
surface. These barriers disappear later in development and are absent in the
adult. 5. There is a decline in permeability to low molecular weight lipid
insoluble compounds during brain development which appears to be due mainly to a
decrease in the intrinsic permeability of the blood-brain and blood-cerebrospinal
fluid interfaces.
PMID- 10690501
TI - The nature and composition of the internal environment of the developing brain.
AB - 1. The fetal brain develops within its own environment, which is protected from
free exchange of most molecules among its extracellular fluid, blood plasma, and
cerebrospinal fluid (CSF) by a set of mechanisms described collectively as "brain
barriers." 2. There are high concentrations of proteins in fetal CSF, which are
due not to immaturity of the blood-CSF barrier (tight junctions between the
epithelial cells of the choroid plexus), but to a specialized transcellular
mechanism that specifically transfers some proteins across choroid plexus
epithelial cells in the immature brain. 3. The proteins in CSF are excluded from
the extracellular fluid of the immature brain by the presence of barriers at the
CSF-brain interfaces on the inner and outer surfaces. These barriers are not
present in the adult. 4. Some plasma proteins are present within the cells of the
developing brain. Their presence may be explained by a combination of specific
uptake from the CSF and synthesis in situ. 5. Information about the composition
of the CSF (electrolytes as well as proteins) in the developing brain is of
importance for the culture conditions used for experiments with fetal brain
tissue in vitro, as neurons in the developing brain are exposed to relatively
high concentrations of proteins only when they have cell surface membrane contact
with CSF. 6. The developmental importance of high protein concentrations in CSF
of the immature brain is not understood but may be involved in providing the
physical force (colloid osmotic pressure) for expansion of the cerebral
ventricles during brain development, as well as possibly having nutritive and
specific cell development functions.
PMID- 10690502
TI - Tight junctions of the blood-brain barrier.
AB - 1. The blood-brain barrier is essential for the maintenance and regulation of the
neural microenvironment. The blood-brain barrier endothelial cells comprise an
extremely low rate of transcytotic vesicles and a restrictive paracellular
diffusion barrier. The latter is realized by the tight junctions between the
endothelial cells of the brain microvasculature, which are subject of this
review. Morphologically, blood-brain barrier-tight junctions are more similar to
epithelial tight junctions than to endothelial tight junctions in peripheral
blood vessels. 2. Although blood-brain barrier-tight junctions share many
characteristics with epithelial tight junctions, there are also essential
differences. However, in contrast to tight junctions in epithelial systems,
structural and functional characteristics of tight junctions in endothelial cells
are highly sensitive to ambient factors. 3. Many ubiquitous molecular
constituents of tight junctions have been identified and characterized including
claudins, occludin, ZO-1, ZO-2, ZO-3, cingulin, and 7H6. Signaling pathways
involved in tight junction regulation comprise, among others, G-proteins, serine,
threonine, and tyrosine kinases, extra- and intracellular calcium levels, cAMP
levels, proteases, and TNF alpha. Common to most of these pathways is the
modulation of cytoskeletal elements which may define blood-brain barrier
characteristics. Additionally, cross-talk between components of the tight
junction- and the cadherin-catenin system suggests a close functional
interdependence of the two cell-cell contact systems. 4. Recent studies were able
to elucidate crucial aspects of the molecular basis of tight junction regulation.
An integration of new results into previous morphological work is the central
intention of this review.
PMID- 10690503
TI - Transferrin and transferrin receptor function in brain barrier systems.
AB - 1. Iron (Fe) is an essential component of virtually all types of cells and
organisms. In plasma and interstitial fluids, Fe is carried by transferrin. Iron
containing transferrin has a high affinity for the transferrin receptor, which is
present on all cells with a requirement for Fe. The degree of expression of
transferrin receptors on most types of cells is determined by the level of Fe
supply and their rate of proliferation. 2. The brain, like other organs, requires
Fe for metabolic processes and suffers from disturbed function when a Fe
deficiency or excess occurs. Hence, the transport of Fe across brain barrier
systems must be regulated. The interaction between transferrin and transferrin
receptor appears to serve this function in the blood-brain, blood-CSF, and
cellular-plasmalemma barriers. Transferrin is present in blood plasma and brain
extracellular fluids, and the transferrin receptor is present on brain capillary
endothelial cells, choroid plexus epithelial cells, neurons, and probably also
glial cells. 3. The rate of Fe transport from plasma to brain is developmentally
regulated, peaking in the first few weeks of postnatal life in the rat, after
which it decreases rapidly to low values. Two mechanisms for Fe transport across
the blood-brain barrier have been proposed. One is that the Fe-transferrin
complex is transported intact across the capillary wall by receptor-mediated
transcytosis. In the second, Fe transport is the result of receptor-mediated
endocytosis of Fe-transferrin by capillary endothelial cells, followed by release
of Fe from transferrin within the cell, recycling of transferrin to the blood,
and transport of Fe into the brain. Current evidence indicates that although some
transcytosis of transferrin does occur, the amount is quantitatively insufficient
to account for the rate of Fe transport, and the majority of Fe transport
probably occurs by the second of the above mechanisms. 4. An additional route of
Fe and transferrin transport from the blood to the brain is via the blood-CSF
barrier and from the CSF into the brain. Iron-containing transferrin is
transported through the blood-CSF barrier by a mechanism that appears to be
regulated by developmental stage and iron status. The transfer of transferrin
from blood to CSF is higher than that of albumin, which may be due to the
presence of transferrin receptors on choroid plexus epithelial cells so that
transferrin can be transported across the cells by a receptor-mediated process as
well as by nonselective mechanisms. 5. Transferrin receptors have been detected
in neurons in vivo and in cultured glial cells. Transferrin is present in the
brain interstitial fluid, and it is generally assumed that Fe which transverses
the blood-brain barrier is rapidly bound by brain transferrin and can then be
taken up by receptor-mediated endocytosis in brain cells. The uptake of
transferrin-bound Fe by neurons and glial cells is probably regulated by the
number of transferrin receptors present on cells, which changes during
development and in conditions with an altered iron status. 6. This review focuses
on the information available on the functions of transferrin and transferrin
receptor with respect to Fe transport across the blood-brain and blood-CSF
barriers and the cell membranes of neurons and glial cells.
PMID- 10690505
TI - Can molecular assessment improve classification of head and neck premalignancy?
PMID- 10690504
TI - The blood-brain barrier and bilirubin encephalopathy.
AB - 1. The pathogenesis of bilirubin encephalopathy is multifactorial, involving the
transport of bilirubin or albumin/bilirubin across the blood-brain barrier and
delivering bilirubin to target neurons. 2. The relative importance of the blood
brain barrier, unconjugated bilirubin levels, serum binding, and tissue
susceptibility in this process is only partially understood. Even at dangerously
high serum levels, bilirubin traverses the intact blood-brain barrier slowly,
requiring time for encephalopathy to occur, although deposition of bilirubin can
be rapid if a surge in plasma unbound bilirubin is produced by administering a
drug which competes with bilirubin for binding to albumin. 3. There may be
maturational changes in permeability both in the fetus and postnatally which
protect the brain from bilirubin. 4. Disruption or partial disruption of the
blood-brain barrier by disease or hypoxic ischemic injury will facilitate
transport of bilirubin/albumin into brain, but the relative affinities of albumin
and target neurons will determine whether the tissue bilirubin load is sufficient
for toxicity to occur.
PMID- 10690506
TI - Modulation of molecular targets to enhance radiation.
PMID- 10690507
TI - Targeted toxins.
AB - Targeted toxins, consisting of tumor-selective ligands coupled to polypeptide
toxins, represent a new class of cancer therapeutics that kills malignant cells
by inactivating cytosolic protein synthesis and inducing apoptosis. A number of
these molecules have been produced under good manufacturing practice conditions
and given systemically to patients with a variety of neoplasms. The promising
results to date and the remaining pharmacological hurdles are discussed.
PMID- 10690508
TI - Molecular determinants of response to TRAIL in killing of normal and cancer
cells.
AB - The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL or Apo2L) is a
potent inducer of death of cancer but not normal cells, which suggests its
potential use as a tumor-specific antineoplastic agent. TRAIL binds to the
proapoptotic death receptors DR4 and the p53-regulated proapoptotic KILLER/DR5 as
well as to the decoy receptors TRID and TRUNDD. In the present studies, we
identified a subgroup of TRAIL-resistant cancer cell lines characterized by low
or absent basal DR4 or high expression of the caspase activation inhibitor FLIP.
Four of five TRAIL-sensitive cell lines expressed high levels of DR4 mRNA and
protein, whereas six of six TRAIL-resistant cell lines expressed low or
undetectable levels of DR4 (chi 2; P < 0.01). FLIP expression appeared elevated
in five of six (83%) TRAIL-resistant cell lines and only one of five (20%) TRAIL
sensitive cells (chi 2; P < 0.05). Two TRAIL-resistant lines that expressed DR4
contained an A-to-G alteration in the death domain encoding arginine instead of
lysine at codon 441. The K441R polymorphism is present in 20% of the normal
population and can inhibit DR4-mediated cell killing in a dominant-negative
fashion. The expression level of KILLER/DR5, TRID, TRUNDD or TRID, and TRUNDD did
not correlate with TRAIL sensitivity (P > 0.05). These results suggest that the
major determinants for TRAIL sensitivity may be the expression level of DR4 and
FLIP. TRAIL-resistant cells became susceptible to TRAIL-mediated apoptosis in the
presence of doxorubicin. In TRAIL-sensitive cells, caspases 8, 9, and 3 were
activated after TRAIL treatment, but in TRAIL-resistant cells, they were
activated only by the combination of TRAIL and doxorubicin. Our results suggest:
(a) evaluation of tumor DR4 and FLIP expression and host DR4 codon 441 status
could be potentially useful predictors of TRAIL sensitivity, and (b) doxorubicin,
in combination with TRAIL, may effectively promote caspase activation in TRAIL
resistant tumors.
PMID- 10690509
TI - Genetic progression and clonal relationship of recurrent premalignant head and
neck lesions.
AB - We constructed a preliminary genetic progression model for head and neck squamous
cell carcinoma (HNSC) based on the frequency of genetic alterations in
preneoplastic and neoplastic lesions from single biopsy specimens. To firmly
establish the temporal order of established genetic events in HNSC, we sampled
serial biopsies from five patients with recurrent premalignant lesions at a
single anatomic site over a period of time (1 month to 144 months). These lesions
were examined by microsatellite analysis of the minimal regions of loss on the 10
most frequently lost chromosomal arms in HNSC. Each set of serial biopsies from
all five patients demonstrated LOH (loss of heterozygosity) of identical alleles
at multiple loci with identical boundaries between areas of LOH and retention of
heterozygosity, indicating a common clonal origin for each set. Three patients
demonstrated genetic progression (new regions of LOH) over time correlating with
histopathological progression, one patient demonstrated lack of genetic
progression associated with unchanged histopathological morphology, and one
patient demonstrated histopathological progression without detection of a
corresponding genetic progression event. For one of these patients with a
laryngeal tumor, at least four separate steps in progression to malignancy could
be determined, accompanied by spatial expansion of an increasingly altered clonal
population from the ipsilateral to the contralateral side, ultimately resulting
in a malignancy. Microsatellite-based genetic analysis of recurrent premalignant
lesions indicates that these lesions arise from a common clonal progenitor,
followed by outgrowth of clonal populations associated with progressive genetic
alterations and phenotypic progression to malignancy.
PMID- 10690510
TI - Characterization of intracellular prostate-specific antigen from laser capture
microdissected benign and malignant prostatic epithelium.
AB - The proportion of unbound serum prostate-specific antigen (PSA; percent-free PSA)
is reported to be lower in men with prostate cancer compared to men with benign
prostates (U. H. Stenman et al., Cancer Res., 51: 222-226, 1991; H. Lilja et al.,
Clin. Chem., 37: 1618-1625, 1991; D. L. Woodrum et al., J. Urol., 159: 5-12,
1998; W. J. Catalona et al., J. Am. Med. Assoc., 279: 1542-1547, 1998). The
majority of immunoreactive PSA in serum is complexed to alpha-1-antichymotrypsin
(ACT). Two major mechanistic questions have previously been unknown: (a) Does PSA
in human prostate cancer cells in tissue exist in a free or bound form? and (b)
Is PSA produced by malignant cells in the free form because it has lost the
ability to form a complex with ACT? Laser capture microdissection (LCM) enables
the acquisition of pure populations of defined cell types from tissue (M. R.
Emmert-Buck et al., Science, 274: 998-1001, 1996; R. F. Bonner et al., Science,
278: 1481-1483, 1997). This technology provides a unique opportunity to study
intracellular protein composition and structure from human cells. In this study,
we used LCM to assess the bound versus free form of intracellular PSA in both
benign and malignant epithelium procured from prostate tissue. One-dimensional
and two-dimensional PAGE were performed on cellular lysates from LCM-procured
benign and malignant prostate epithelium from frozen tissue specimens. Western
blotting analysis of one-dimensional PAGE gels revealed a strong band at M(r)
30,000 (expected molecular weight of unbound PSA) in all cases demonstrating that
the vast majority of intracellular tumor and normal PSA exists within cells in
the "free" form. Binding studies showed that PSA recovered from LCM-procured
cells retained the full ability to bind ACT, and two-dimensional PAGE Western
analysis demonstrated that the PSA/ACT complex was stable under strong reducing
conditions. We conclude that intracellular PSA exists in the "free" form and that
binding to ACT occurs exclusively outside of the cell.
PMID- 10690511
TI - Use of allelic loss to predict malignant risk for low-grade oral epithelial
dysplasia.
AB - One of the best approaches to identifying genetic changes critical to oral cancer
progression is to compare progressing and nonprogressing oral premalignant
lesions. However, such samples are rare, and they require long-term follow-up.
The current study used the large archive network and clinical database in British
Columbia to study loss of heterozygosity (LOH) in cases of early oral
premalignancies, comparing those with a history of progression to carcinoma in
situ or invasive cancer and those without a history of progression (referred to
as nonprogressing cases). Each of 116 cases was analyzed for LOH at 19
microsatellite loci on seven chromosome arms (3p, 4q, 8p, 9p, 11q, 13q, and 17p).
The progressing and nonprogressing cases showed dramatically different LOH
patterns of multiple allelic losses. An essential step for progression seems to
involve LOH at 3p and/or 9p because virtually all progressing cases showed such
loss. However, LOH at 3p and/or 9p also occurred in nonprogressing cases.
Individuals with LOH at 3p and/or 9p but at no other arms exhibit only a slight
increase of 3.8-fold in relative risk for developing cancer. In contrast,
individuals with additional losses (on 4q, 8p, 11q, or 17p), which appeared
uncommon in nonprogressing cases, showed 33-fold increases in relative cancer
risk. In conclusion, analysis of LOH at 3p and 9p could serve as an initial
screening for cancer risk of early premalignancies. Follow-up investigation for
additional losses would be essential for predicting cancer progression.
PMID- 10690512
TI - Successful surgical removal of occult metastases of medullary thyroid carcinoma
recurrences with the help of immunoscintigraphy and radioimmunoguided surgery.
AB - Patients with recurrent or metastatic medullary thyroid carcinoma (MTC) were
referred for pretargeted immunoscintigraphy (Affinity Enhancement System; AES)
and radioimmunoguided surgery (RIGS). Data collected from 13 patients establish
that whole-body AES immunoscintigraphy revealed metastases < 360 mg and RIGS
detected micrometastases (5-15 mg). All tissue samples removed by the surgeon
were diagnosed by histology and immunohistochemistry of calcitonin to check the
accuracy of IS and RIGS results. AES immunoscintigraphy is very sensitive. Of 34
metastases or recurrences detected, 22 had escaped physical examination or
conventional imaging. The accuracy of RIGS was 86%, its sensitivity 75%, and its
specificity was 90% (n = 208). IS and RIGS detected occult tumors that would have
escaped surgery, clearly demonstrating clinical benefit. Serum calcitonin
(normal, 10 pg/ml) and carcinoembryonic antigen (normal, 5 ng/ml) of two patients
were restored to normal. In patients whose tumors were discovered, progression of
their disease was slowed, as evidenced by the large decrease in serum calcitonin
and carcinoembryonic antigen, an important prognostic factor. Surgery was
canceled in one case where IS detected distant metastases out of surgical reach.
Thus, AES immunoscintigraphy and RIGS might be of valuable help for the surgical
management of medullary thyroid carcinoma.
PMID- 10690513
TI - Molecular remission induction with retinoic acid and anti-CD33 monoclonal
antibody HuM195 in acute promyelocytic leukemia.
AB - Despite achieving complete remission with retinoic acid (RA), most patients with
acute promyelocytic leukemia (APL) have minimal residual disease detectable by
reverse transcription-PCR (RT-PCR) amplification. HuM195, a humanized monoclonal
antibody reactive with the cell surface antigen CD33, specifically targets and
kills myeloid leukemia cells. We studied whether HuM195 could eliminate minimal
residual disease in patients with APL by using RT-PCR. After attaining clinical
complete remission with RA and/or chemotherapy, patients received HuM195 twice
weekly for 3 weeks. Patients in first remission were given consolidation
chemotherapy, generally with three cycles of idarubicin and cytarabine. Patients
in second or greater remission did not receive chemotherapy. All patients
received six monthly courses of maintenance with two doses of HuM195. Twenty-five
of 27 patients treated in first remission had positive RT-PCR determinations
before HuM195 treatment. Of the 22 patients evaluable for conversion of positive
RT-PCR assays, 11 (50%) became RT-PCR negative after HuM195 treatment without
additional therapy. Within the subset of patients who received RA alone as
induction, 8 of 18 evaluable patients (44%) had negative RT-PCR determinations
after HuM195 treatment but before chemotherapy. Among similar patients treated on
earlier studies, 7 of 34 patients (21%) induced into remission with RA and then
maintained on the drug for 1 month were RT-PCR negative before chemotherapy (P =
0.07). Twenty-five of 27 patients with newly diagnosed APL (93%) remain in
clinical complete remission for 7+ to 58+ months, with median follow-up of 29
months. Seven patients in second or third remission and one patient in molecular
relapse were also treated. Only one of these patients became RT-PCR negative
after treatment with HuM195. These data suggest that HuM195 has activity against
minimal residual disease in APL, particularly in newly diagnosed patients.
PMID- 10690514
TI - Angiogenesis, thymidine phosphorylase, and resistance of squamous cell head and
neck cancer to cytotoxic and radiation therapy.
AB - Thymidine phosphorylase (TP), an enzyme involved in the thymidine synthesis and
degradation, has been shown to promote tumor angiogenesis. Both TP expression and
tumor vascularization are putative postoperative prognostic markers of cancer.
Because of its bifunctional role, TP may have interactions with cytotoxic drugs
or radiation via pathways requiring thymidine or prodrug activation. The
microvessel score and TP expression were examined immunohistochemically on
paraffin-embedded bioptical material from 94 locally advanced squamous cell head
and neck carcinomas. All patients were treated with conventionally fractionated
radiotherapy combined with induction (platinum- and 5-fluorouracil-based) or
concurrent platinum chemotherapy. The follow-up of patients ranged from 6 to 108
months (median, 48 months). Nuclear TP expression was significantly associated
with increased microvessel score (P < 0.0001, r = 0.45). A low percentage of
cancer cells with nuclear TP expression in pretreatment biopsies was associated
with a high rate of CR after combined chemoradiotherapy (P = 0.006) and induction
chemotherapy (0.01). A better local relapse-free and overall survival was also
observed in these patients (P = 0.001 and P = 0.0005, respectively). Biospies on
the day after the delivery of 20 Gy of conventionally fractionated radiotherapy
showed residual cancer cell nests, frequently of high vascularization and of
intense nuclear TP reactivity. It is concluded that thymidine phosphorylase is
associated with angiogenesis, with resistance to radiotherapy and cytotoxic
therapy, and with poorer survival in squamous cell head and neck cancer. A strong
rationale is provided for subsequent clinical trials of concurrent radiotherapy
and chemotherapy with antiangiogenic agents or with specific TP inhibitors.
PMID- 10690515
TI - Phase I clinical and pharmacokinetic study of perillyl alcohol administered four
times a day.
AB - We conducted a phase I dose-escalation trial of perillyl alcohol (POH; NSC
641066) given p.o. on a continuous four times a day basis to characterize the
maximum tolerated dose, toxicities, pharmacokinetic profile, and antitumor
activity. Sixteen evaluable patients with advanced refractory malignancies were
treated at the following doses: level 1 (L1), 800 mg/m2/dose; L2, 1200
mg/m2/dose; L3, 1600 mg/m2/dose. POH was formulated in soft gelatin capsules
containing 250 mg of POH and 250 mg of soybean oil. The predominant toxicities
seen were gastrointestinal (nausea, vomiting, satiety, and eructation), which
were dose limiting. There appeared to be a dose-dependent increase in levels of
the two main metabolites, perillic acid and dihydroperillic acid. No significant
differences were seen whether the drug was taken with or without food. There was
a trend toward decreasing metabolite levels on day 29 compared with days 1 and 2.
Peak metabolite levels were seen 1-3 h post ingestion. Metabolite half-lives were
approximately 2 h. Approximately 9% of the total dose was recovered in the urine
in the first 24 h, the majority as perillic acid. Evidence of antitumor activity
was seen in a patient with metastatic colorectal cancer who has an ongoing near
complete response of > 2 years duration. Several other patients were on study for
> or = 6 months with stable disease. The maximum tolerated dose of POH given
continuously four times a day was 1200 mg/m2/dose. Gastrointestinal toxicity was
dose limiting, although significant interpatient variability in drug tolerance
was seen.
PMID- 10690516
TI - Phase I study of ONO-4007, a synthetic analogue of the lipid A moiety of
bacterial lipopolysaccharide.
AB - ONO-4007 is a synthetic analogue of the lipid A moiety of bacterial
lipopolysaccharide, which exhibits antitumor activity by the induction of
intratumoral tumor necrosis factor alpha, the potentiation of tumor-infiltrating
macrophages, and the inhibition of angiogenesis. Interleukin (IL)-1 alpha, IL-6,
and IL-12 induction by ONO-4007 activates cytotoxic natural killer cells to up
regulate IFN-gamma and nitric oxide synthase activity. ONO-4007 was given to 24
patients (13 males and 11 females; median age, 53 years) as a 30-min i.v.
infusion on day 1, followed on day 15 by a first treatment cycle consisting of
three weekly infusions at the same dose, followed by a rest period of 1 week.
Cohorts of six patients received up to a maximum of four treatment cycles at
increasing dose levels (75, 100, and 125 mg). The maximum tolerated dose was 125
mg, with grade 3 National Cancer Institute Common Toxicity Criteria toxicity
(rigors with cyanosis) occurring in two of six patients at this dose level. An
additional six patients were treated at 100 mg, the dose below the maximum
tolerated dose. Other toxicities included grade 2 National Cancer Institute
Common Toxicity Criteria myalgia, nausea, and hypotension. The pharmacokinetics
of ONO-4007 appeared to be independent of dose and showed linearity with respect
to time. ONO-4007 has a low systemic clearance (approximately 1.3 ml/min) and a
small volume of distribution (5-8 liters) with a long t1/2 of 74-95 h. The
administration of ONO-4007 was shown to result in a significant increase in
circulating levels of tumor necrosis factor alpha and IL-6. No objective
antitumor responses were observed. Seven patients maintained stable disease for
at least two cycles, whereas five patients maintained stable disease for the full
four-cycle duration of the study. Additional studies are required to determine
the antitumor activity of ONO-4007.
PMID- 10690517
TI - Phase II trial of yttrium-90-DOTA-biotin pretargeted by NR-LU-10
antibody/streptavidin in patients with metastatic colon cancer.
AB - A Phase II study of yttrium-90-tetra-azacyclododecanetetra-acetic acid-biotin
(90Y-DOTA-biotin) pretargeted by NR-LU-10 antibody/streptavidin (SA) was
performed. The primary objectives of the study were to evaluate the efficacy and
safety of this therapy in patients with metastatic colon cancer. Twenty-five
patients were treated with a single dose of 110 mCi/m2 (mean administered dose,
106.5 +/- 10.3 mCi/m2) of 90Y-DOTA-biotin. There were three components of the
therapy. Patients first received NR-LU-10/SA on day 1. A clearing agent (biotin
galactose-human serum albumin) was administered approximately 48 h after the NR
LU-10/SA to remove residual circulating unbound NR-LU-10/SA. Lastly, 24 h after
administration of clearing agent, patients received biotin-DOTA-labeled with 110
mCi/m2 90Y. All three components of the therapy were administered i.v. Both
hematological and nonhematological toxicities were observed. Diarrhea was the
most frequent grade 4 nonhematological toxicity (16%; with 16% grade 3 diarrhea).
Hematological toxicity was less severe with 8% grade 3 and 8% grade 4 neutropenia
and 8% grade 3 and 16% grade 4 thrombocytopenia. The overall response rate was
8%. Two partial responders had freedom from progression of 16 weeks. Four
patients (16%) had stable disease with freedom from progression of 10-20 weeks.
Despite the relatively disappointing results of this study in terms of
therapeutic efficacy and toxicity, proof of principle was obtained for the
pretargeting approach. In addition, valuable new information was obtained about
normal tissue tolerance to low-dose-rate irradiation that will help to provide
useful guidelines for future study designs.
PMID- 10690518
TI - Modulation of clinical drug resistance in a B cell lymphoma patient by the
protein kinase inhibitor 7-hydroxystaurosporine: presentation of a novel
therapeutic paradigm.
AB - Emerging evidence suggests that apoptosis is an important mechanism of tumor cell
death from antineoplastic therapy. 7-hydroxystaurosporine (UCN-01) is a novel
protein kinase inhibitor that increases chemotherapy-induced apoptosis in vitro
and is in early phases of clinical development. In this report, we present a 68
year-old patient with chemotherapy-resistant lymphoma treated with UCN-01 and
chemotherapy. He had a stage IV plasmacytoid lymphoma that failed to enter
remission with high-dose EPOCH II (etoposide, prednisone, vincristine,
cyclophosphamide, doxorubicin) chemotherapy. Due to disease progression and
transformation to large cell lymphoma in the liver and bone marrow, he received
UCN-01. Four weeks later, he received "standard-dose" EPOCH because of
progression, developed severe neutropenia for 9 days, and expired from Candida
sepsis on day 23. At autopsy, there was no histological evidence of residual
lymphoma, although PCR for immunoglobulin gene rearrangement analysis revealed a
faint clonal band in two of six nodes but none in the liver. Significantly, no B
cells were detected by immunohistochemistry in lymph nodes, and a polyclonal
ladder pattern associated with the presence of normal B cells was not seen in the
immunoglobulin gene rearrangement PCR assay. Profound peripheral lymphopenia (50
cells/microliter) was also observed. Pharmacokinetics showed UCN-01 salivary
concentrations, a surrogate for free drug concentrations, to be within an
effective range in vitro (45 nmol/L) as a modulator of DNA-damaging agent
cytotoxicity. In vitro, UCN-01 is synergistic with multiple cytotoxic agents and
increases fludarabine-induced apoptosis in a human breast cell line. These
results suggest that UCN-01 sensitized the lymphoma to the cytotoxic effects of
EPOCH, possibly by modulating the "threshold" for apoptosis, and may illustrate a
new paradigm for reversal of drug resistance.
PMID- 10690519
TI - A neoadjuvant clinical trial in colorectal cancer patients of the human anti
idiotypic antibody 105AD7, which mimics CD55.
AB - Thirty-five patients received 105AD7 human anti-idiotype vaccination prior to
surgery for colorectal carcinoma. Patients were immunized before and also
received one to two immunizations after surgical resection of their colorectal
cancer. The vaccine was well tolerated with no associated toxicity. Lymphocytic
infiltration within the resected tumors was quantified by immunohistochemistry
and image analysis. Enhanced infiltration of helper T cells (CD4) and natural
killer (NK) cells (CD56) were observed in the tumors from immunized patients when
compared with tumors from stage, grade, site, age, and sex matched unimmunized
patients. NK activity was increased in the blood, peaking 7-10 days post
immunization and then dropping rapidly and correlating with NK extravasation
within the tumor. Comparison of the amino acid sequences of 105AD7 anti-idiotype
and the antigen it mimics, CD55, has predicted that patients with HLA-DR1, HLA
DR3, and HLA-DR7 haplotypes should show helper T cell responses following 105AD7
vaccination. Eighty-three percent of patients expressing these haplotypes
responded to 105AD7, whereas 88% of patients who failed to express these
haplotypes were nonresponders. With a median follow-up of 4 years (range, 2.5-6
years) 65% of patients remained disease free. This trial shows that 105AD7
stimulates antitumor inflammatory responses allowing extravasation within tumor
deposits of both helper T cells and NK cells. This represents a way of evaluating
immune responses in patients both within the blood and at the tumor site. The
study confirms that immunization with a human anti-idiotypic antibody results in
immune responses in 83% of patients with a permissive haplotype.
PMID- 10690520
TI - Effect of food on the pharmacokinetics of oral MMI270B (CGS 27023A), a novel
matrix metalloproteinase inhibitor.
AB - MMI270B is a matrix metalloproteinase inhibitor (MMPI) with in vitro and in vivo
activity. To exert optimal target inhibition, MMPI must be given chronically, and
therefore, oral bioavailability is important. We analyzed the effect of food
intake on AUC0-8 h, Cmax, and Tmax. Seventeen patients were entered into the
study. Doses of MMI270B were 150, 400, and 600 mg. The first day, patients
ingested the drug in a fasted state and were not allowed to eat for 2 h. The
second day, patients ingested the drug 30 min after a light breakfast. Mean AUC0
8 h was not significantly influenced by food intake. Plasma concentrations were
well above the IC50 of several MMPs at all doses tested. Mean Cmax was
significantly decreased after food intake. Mean Tmax was significantly delayed
after food intake. Food intake did not result in a significant change in exposure
to MMI270B (AUC0-8 h) but did result in a significant, although not clinically
relevant, decrease in peak plasma levels and time to reach peak plasma levels. No
specific guidelines concerning the ingestion of MMI270B in either a fed or a
fasted state are recommended.
PMID- 10690521
TI - Detection and analysis of cancer cells in blood and bone marrow using a rare
event imaging system.
AB - An automated rare event detection system (Rare Event Imaging System) is described
for the recognition of cancer cells that appear at low frequencies (1 in 1
million) in peripheral blood (PB) or bone marrow (BM). The instrumentation
includes an automated fluorescence microscope (Nikon Microphot-FXA) with a cooled
charge coupled device camera and a 60-MHz Pentium personal computer. Main
features of the system are rapid analysis of large microscopic fields, including
a total cell count, detection of fluorescently labeled cells, and a display of
digitally stored images of the detected cells. Furthermore, the X,Y coordinates
of each identified object are stored and can be recalled for morphological
analysis of the cell using higher magnification or different fluorescent filter
sets. The preparation of the blood or BM samples for automated analysis consists
of lysis of the RBCs, attachment of sample cells onto adhesion slides, fixation,
and fluorescent labeling with anticytokeratin antibodies. Cytokeratin-positive
cells, however, were detected in 17% of the samples from healthy blood donors
using this procedure (mean number, approximately 7/10(6) mononuclear cells in
positive samples). To improve the specificity of the rare event detection, a
double-labeling protocol combining intracellular cytokeratin with epithelial cell
adhesion molecule (Ep-CAM) (breast, ovarian, colon, and lung carcinoma antigen)
or disialo-ganglioside (GD2) antigen (small cell lung carcinoma, neuroblastoma,
melanoma antigen) was developed. Examples of doubly labeled cultured cells and
cancer cells from breast and small cell lung cancer patients are shown. Using the
double-labeling protocol, no "positive" cells were seen in samples of healthy
blood donors. Automated rare event detection (cytokeratin single-staining) was
applied to 355 PB, BM, and stem cell (SC) samples from breast cancer patients
before autologous BM transplantation. Cytokeratin-positive cells were found in
52% of BM, 35% of PB, and 27% of SC samples at frequencies of 1-1020 positive
cells/10(6) mononuclear cells, thereby establishing the efficacy of the technique
in the detection of rare cancer cells in hematopoietic tissue samples of cancer
patients.
PMID- 10690522
TI - Prognostic significance of mutations to different structural and functional
regions of the p53 gene in breast cancer.
AB - Alteration to the p53 tumor suppressor gene is associated with more aggressive
disease in breast cancer, as evidenced by the shortened survival of patients with
mutation. Data obtained from in vitro experiments suggest that mutations to
different structural and functional domains of p53 may give rise to different
effects on its biological activities, notably transactivational and apoptotic
properties. We evaluated the prognostic significance of various types of p53
mutation in a series of 178 tumors identified by PCR-single-strand conformational
polymorphism screening as containing a mutant gene. Mutations within exon 4 were
associated with particularly poor prognosis, possibly relating to the importance
of this region in apoptosis. Mutations that caused denaturation of the protein
structure were also associated with poor survival, again perhaps because of
effects on apoptosis. In contrast, patients with mutations in the DNA contact
region showed similar survival to that of patients with normal p53, suggesting a
less important role for p53-mediated transactivation in determining tumor
aggressiveness. Other mutation groups associated with poor prognosis were single
base substitutions and transversion mutations. Mutations in exon 6, exon 7, or
the "hotspot" codons (175, 245, 248, 273) were associated with only a small
reduction in patient survival compared with normal p53. These results allow some
insight to be gained into the functional importance of various p53 domains in
terms of their influence on overall patient survival. Further work is required to
determine whether these domains are also important in influencing the response of
breast tumors to adjuvant therapies.
PMID- 10690523
TI - Quantitation of hTERT gene expression in sporadic breast tumors with a real-time
reverse transcription-polymerase chain reaction assay.
AB - Recent observations support the notion that telomerase expression is essential
for the formation of human tumor cells [W-C. Hahn et al., Nature (Lond.), 400:
464-468, 1999]. The expression pattern of hTERT, the human telomerase catalytic
subunit gene, is a rate-limiting determinant of the enzymatic activity of human
telomerase. We have developed a real-time quantitative RT-PCR assay based on Taq
Man fluorescence methodology to quantify the full range of hTERT mRNA copy
numbers. We validated the method on a series of 134 unilateral invasive primary
breast cancer patients with known long-term outcome. Three-quarters of the breast
tumors (75.4%; 101 of 134) were hTERT positive, i.e., contained detectable and
quantifiable hTERT mRNA. hTERT-positive patients had significantly shorter
relapse-free survival (P = 0.017) after surgery compared with hTERT-negative
patients. The prognostic significance of hTERT status persisted in Cox
multivariate regression analysis. When we subdivided hTERT-positive patients (n =
101) into three equal groups (tumors showing small, intermediate, or high
increase in hTERT mRNA content), we observed statistical (or a trend toward)
links between high hTERT mRNA levels and Scarff-Bloom-Richardson
histopathological grade III (P = 0.066), and negative estrogen (P = 0.002) and
progesterone (P = 0.048) receptor status, and therefore with higher
aggressiveness of breast tumors. High hTERT mRNA levels were also linked to MYC
gene overexpression (P = 0.007). These findings show that the quantitative
evaluation of hTERT mRNA can have important prognostic significance in human
breast cancer. In addition, our simple, rapid, and semiautomated assay method is
suitable for routine hTERT mRNA detection and quantification and will be a
powerful tool in large, randomized, prospective, cooperative group trials and in
the hTERT-based therapy project.
PMID- 10690524
TI - Altered expression of beta-catenin in renal cell cancer and transitional cell
cancer with the absence of beta-catenin gene mutations.
AB - Loss of normal beta-catenin expression and the beta-catenin gene mutations have
been shown to contribute to the malignant character of various cancers. Using PCR
single-strand conformation polymorphism and DNA direct sequencing, we examined
the presence of genetic alterations within the third exon of beta-catenin, which
are frequently observed in other tumors, in transitional cell cancer (TCC) and
renal cell cancer (RCC) cell lines, and in tumor specimens. The degrees of
expression and intracellular distribution of beta-catenin were detected by
immunohistochemical staining in 77 primary and 12 metastatic RCCs and in 81
primary TCCs. Western blot analysis was also applied to confirm the degree of
beta-catenin expression in the cell lines and some tumor samples. We failed to
reveal any genetic alterations, at least in the third exon of the beta-catenin
gene, in RCC and TCC. Reduced membranous immunoreactivity of beta-catenin was
observed in portions of RCC (15.5%) and TCC (24.7%) and was correlated with
advanced stages and nodal involvement in RCC and with advanced stages and
multiple tumors in TCC. Within the power limitations of this small study, beta
catenin abnormal expression was not correlated with recurrence or survival in
either RCC or TCC. Interstitial deletions and mutations in the third exon of beta
catenin do not play a significant role in RCC or TCC tumorigenesis. Down
regulation of normal beta-catenin expression might contribute to the malignant
character of RCC and TCC and result in tumor progression. However, this event is
not an independent prognostic factor for recurrence or tumor specific survival.
PMID- 10690525
TI - Serum total and free prostate-specific antigen for breast cancer diagnosis in
women.
AB - Prostate-specific antigen (PSA) is a serine protease expressed at high levels in
prostate epithelium, and elevated PSA in serum is a well-established marker of
prostate cancer. Recently, the relative proportions of free PSA and PSA complexed
to the serine protease inhibitor alpha 1-antichymotrypsin have become important
variables in distinguishing between prostate cancer and benign prostatic
hyperplasia. Numerous studies have demonstrated the production of PSA in female
tissues such as the breast, and low levels of PSA are present in female sera. The
objective of this study was to measure and compare the relative proportions of
free PSA and PSA complexed to the serine protease inhibitor alpha 1
antichymotrypsin in the serum of women with breast cancer or benign breast
disease or women with no known malignancies. PSA was measured with an established
immunoassay for total PSA and a novel immunoassay for free PSA, both of which had
a detection limit of 0.001 microgram/liter (1 ng/liter). The percentage of breast
cancer patients with free PSA as the predominant molecular form (> 50% of total
PSA) in serum was five times higher than that of healthy women or women with
benign breast disease, and PSA decreased in the serum of breast cancer patients
after surgery. The diagnostic use of free PSA for breast cancer is limited at
this point, due to the low diagnostic sensitivity (approximately 20%); however,
free PSA as the predominant molecular form shows a high diagnostic specificity
(approximately 96%) in comparison to women free of breast cancer or with benign
breast disease. These results suggest that the clinical applicability of free PSA
for breast cancer diagnosis and the biological mechanism behind its increase
should be further investigated.
PMID- 10690526
TI - Loss of imprinting of the IGF-II and H19 genes in epithelial ovarian cancer.
AB - To establish a possible role of genomic imprinting in the carcinogenesis of
epithelial ovarian cancer, we determined the imprinting status of both IGF-II and
H19 genes in 43 ovarian cancers, 7 low malignant potential ovarian tumors, and
their matched normal tissues. In ovarian cancer, loss of heterozygosity (LOH) of
IGF-II, H19 RsaI, and H19 AluI was found in 4 of 24 (16.7%), 3 of 20 (15%), and 1
of 16 (6.3%) samples, respectively. All patients with tumor specimens exhibiting
LOH are of advanced clinical stages. Loss of imprinting (LOI) was found in 5 of
20 (25%) for IGF-II and in 4 of 17 (23.5%) and 1 of 15 (6.7%) for the RsaI and
AluI sites of H19 gene with no LOH. However, no LOH was found in low malignant
potential tumors, and only one of them showed LOI in H19 AluI site.
Overexpression of IGF-II was demonstrated in all five LOI samples with normal
expression of H19. Three of the five tumor specimens exhibiting LOI were
transcribed from P1 promoter, whereas the remaining two were from the P3
promoter. These results suggested that LOH of both IGF-II and H19 genes was
associated with advanced ovarian cancer. LOI of IGF-II and H19 genes may be
involved in the development of ovarian cancer. Transcription of IGF-II from the
P1 promoter may account for the biallelic expression of the IGF-II gene.
PMID- 10690527
TI - Epigenetic regulation of gene expression in cervical cancer cells by the tumor
microenvironment.
AB - Evidence is accumulating that the adverse tumor microenvironment both modifies
the malignant progression of tumor cells and contributes to chemotherapy and
radiation resistance. We hypothesized that some of the effects on malignant
progression are mediated through the transcriptional regulation of genes
responsive to the stresses of the microenvironment, such as low oxygen or low
glucose conditions. To determine epigenetic changes in gene expression that were
consistent with that hypothesis, we used an in vitro subtractive hybridization
method, representational difference analysis, to identify hypoxia-induced cDNAs
from cultured human cervical epithelial cells. We identified 12 induced genes:
two novel genes (HIG1 and HIG2), three genes known to be hypoxia-inducible
(tissue factor, GAPDH, thioredoxin), and seven genes not previously identified as
hypoxia-inducible [HNRNP(a1), ribosomal L7, annexin V, lipocortin 2, Ku(70), PRPP
synthase, and acetoacetyl-CoA thiolase]. In cultured cells, HIG1 and HIG2
expression is induced by hypoxia and by glucose deprivation, but their expression
is not induced by serum deprivation, UV, or ionizing radiation. The putative HIG1
and HIG2 open reading frames are expressed in cells, as confirmed by epitope
tagging. In addition, tumor xenografts derived from human cervical cancer cells
display increased expression of HIG1 and HIG2 when they are deprived of oxygen.
Taken together, these data suggest a coordinated transcriptional response of
eukaryotic cells to microenvironmental stresses found in the solid tumor.
PMID- 10690528
TI - Immunohistochemically detected thymidylate synthase in colorectal cancer: an
independent prognostic factor of survival.
AB - Intratumoral thymidylate synthase (TS) expression and M(r) 53,000 phosphoprotein
(p53) overexpression were studied immunohistochemically in sections from stored
paraffin-embedded primary colorectal cancers in 70 patients who had undergone
surgery during the years 1987-1990. These cancers were classified according to
Dukes' stage A-D, using monoclonal antibodies TS 106 and DO-7. In patients with
Dukes' stage A-C tumors, univariate analyses showed that there was a significant
correlation (P = 0.048) between disease-free survival and TS expression and
between TS expression and time to death with colorectal cancer (P = 0.038). In
patients with Dukes' stage A-D tumors, overall survival was correlated to TS
expression (P = 0.015), Dukes' stage (P < 0.001), and level of tumor
differentiation (P = 0.044) but not to p53 overexpression. Patients with low
intratumoral TS expression survived significantly longer than patients with high
expression. Cox multivariate analysis showed that Dukes' stage (P < 0.001) and TS
expression (P = 0.043) could independently serve as prognostic factors for time
to death with colorectal cancer in patients with Dukes' stage A-D tumors.
PMID- 10690529
TI - Enhanced GBX2 expression stimulates growth of human prostate cancer cells via
transcriptional up-regulation of the interleukin 6 gene.
AB - Previous studies demonstrated that the GBX2 homeobox gene is consistently
overexpressed in cultured human prostate cancer cell lines. In this study, the
human GBX2 cDNA was cloned and a quantitative reverse transcription-PCR method
used to demonstrate that GBX2 mRNA expression is enhanced in approximately 70% of
human prostate cancer tissues compared with normal human prostate tissues.
Purified recombinant GBX2 protein binds specifically to an ATTA motif within the
promoter of the interleukin 6 (IL-6) gene. Using an antisense approach, down
regulation of the expression of GBX2 correlated with decreased expression of IL-6
and an inhibition of tumorigenicity of PC3 human prostate cancer cells. In
addition, in vitro growth of the antisense clones was partially restored by
exogenous addition of recombinant IL-6 protein to the culture media. These data
demonstrated that enhanced GBX2 expression results in a stimulation of malignant
growth of prostate cancer cells and that part of this stimulation involves up
regulation in the transcription of the IL-6 gene.
PMID- 10690530
TI - Vitamin D receptor polymorphisms are associated with altered prognosis in
patients with malignant melanoma.
AB - Calcitriol [1,25(OH)2D3], the hormonal derivative of vitamin D3, is an
antiproliferative and prodifferentiation factor for several cell types, including
cultured melanocytes and malignant melanoma (MM) cells. Several polymorphisms of
the vitamin D receptor (VDR) gene have been described including a FokI RFLP in
exon 2, BsmI, and ApaI polymorphisms in intron 8 and an adjacent TaqI RFLP in
exon 9. Alterations in vitamin D/1,25(OH)2D3 levels and polymorphisms of the VDR
have been shown to be associated with several systemic malignancies. We
hypothesize that polymorphism in this gene may be associated with altered
susceptibility and outcome in patients with MM. A hospital-based case-control
study, using 316 MM cases and 108 controls, was used to assess associations with
MM susceptibility. Breslow thickness, the most important single prognostic factor
in MM, was used as the outcome measure. Polymorphisms at the FokI and TaqI
restriction sites were determined using PCR-based methods. Polymorphism at the
FokI, but not TaqI, RFLP was associated with an altered risk of MM (P = 0.014).
More importantly, variant alleles were associated with increased Breslow
thickness. Thus, homozygosity for variant alleles at both RFLP (ttff genotype
combination) was significantly associated with thicker tumors. (> or = 3.5 mm; P
= 0.001; odds ratio = 31.5). Thus, polymorphisms of the VDR gene, which would be
expected to result in impaired function, are associated with susceptibility and
prognosis in MM. These data suggest that 1,25(OH)2D3, the ligand of the VDR, may
have a protective influence in MM, as has been proposed for other malignancies.
PMID- 10690531
TI - Cysteine proteinase inhibitors stefin A, stefin B, and cystatin C in sera from
patients with colorectal cancer: relation to prognosis.
AB - The levels of cysteine proteinase inhibitors stefin A, stefin B, and cystatin C
were determined using ELISAs in sera obtained preoperatively from 345 patients
with colorectal cancer and in control sera from 125 healthy blood donors. The
levels of stefin A and cystatin C were found to be moderately increased in
patient sera (1.4-fold and 1.6-fold, respectively; P < 0.0001), whereas the level
of stefin B remained statistically unchanged when compared with controls. The
medians were 4.3 ng/ml versus 3.2 ng/ml for stefin A, 1.2 ng/ml versus 1.7 ng/ml
for stefin B, and 679 ng/ml versus 425 ng/ml for cystatin C. In patient sera, a
weak correlation of cystatin C with age (r = 0.34; P < 0.001) and gender (P =
0.01) was found. Stefin A and cystatin C levels were independent of Dukes' stage,
whereas stefin B correlated significantly with Dukes' stage, its level being the
highest in stage D (P < 0.007). Stefin B and cystatin C correlated with survival,
whereas stefin A was not a significant prognostic factor in this study. Using
medians as cutoff values, patients with high levels of stefin B and patients with
high levels of cystatin C exhibited a significantly higher risk of death than
those with low levels of inhibitors (hazard ratio = 1.6; 95% confidence interval,
1.2-2.2; P = 0.002 for stefin B; hazard ratio = 1.3; 95% confidence interval, 1.0
1.8; P = 0.04 for cystatin C). Our results reveal a correlation between high
levels of extracellular cysteine proteinase inhibitors and short survival in
patients with colorectal cancer, and the data thus support previous studies
suggesting a contributing role of protease inhibitors in the progression of
cancer.
PMID- 10690532
TI - Expression levels of estrogen receptor-alpha, estrogen receptor-beta,
coactivators, and corepressors in breast cancer.
AB - Recent studies have indicated that a complex machinery of transactivation of
target genes by estrogen or antiestrogen through estrogen receptor (ER) exists.
However, the substantial roles of ER-beta, coactivators, and corepressors in the
development and progression of breast cancer remain to be elucidated. To obtain
some clue to these roles, we screened the expression levels of ER-alpha, ER-beta,
coactivators (SRC-1, TIF2, AIB1, CBP, and P/CAF) and corepressors (N-CoR and
SMRT) in 6 normal mammary glands, 6 intraductal carcinomas, 22 invasive ductal
carcinomas, and 7 breast cancer cell lines using a multiplex reverse
transcription-PCR. ER-alpha mRNA expression levels significantly correlated with
ER-alpha protein levels measured by enzyme immunoassay in the breast cancer
tissues and cell lines. A significant correlation of expression levels was
observed between ER-alpha and TIF2, AIB1, P/CAF, and N-CoR, and between ER-beta
and AIB1 and CBP in the tissue samples. A significant correlation was also
observed between ER-alpha and ER-beta and between ER-beta and CBP in the cell
lines. The expression levels of ER-alpha, TIF2, and CBP were significantly higher
in the intraductal carcinomas than those in the normal mammary glands. In
addition, the expression levels of ER-alpha and N-CoR were significantly higher
in the intraductal carcinomas than those in the invasive ductal carcinomas. These
findings suggest a positive correlation of expression levels among ER-alpha and
cofactors and among ER-beta and cofactors, an up-regulation of expression levels
of ER-alpha and cofactors during the development of intraductal carcinomas from
normal mammary glands, and a decrease in their expression levels during the
progression of breast cancer.
PMID- 10690533
TI - Increased expression of cyclooxygenase-2 protein in human gastric carcinoma.
AB - Gastric adenocarcinoma is one of the most common malignancies in the world, and
yet little is known about its molecular process of development and progression.
Recent studies have suggested that ingestion of nonsteroid anti-inflammatory
drugs reduces the risk of colon cancer, presumably by inhibiting the
cyclooxygenase (COX) enzyme. COX-2, one isoform of the COX enzyme, is the rate
limiting enzyme in prostaglandin synthesis, and the function of this enzyme is
thought to relate to inflammatory processes and carcinogenesis. To understand the
role of COX enzyme in gastric cancer, we measured COX-2 expression in 104 human
gastric carcinoma tissues by immunohistochemical analysis. We obtained tissue
specimens from 104 surgically resected gastric adenocarcinoma patients. We
performed immunohistochemical stain for human COX-2 with polyclonal antibody in
gastric carcinoma. After curative resection and extensive lymph node dissection,
all patients received adjuvant chemotherapy containing 5-fluorouracil. Expression
of COX-2 showed cytoplasmic staining, not only in cancer cells but also in
precancerous lesions such as metaplastic and adenomatous cells. We confirmed up
regulation of COX-2 in gastric cancer tissues compared with normal paired mucosa
using Western blot analysis. There was no correlation between clinicopathological
characteristics of gastric cancer patients and intensity of COX-2 protein
expression. This study indicates that COX-2 protein over-expression may
contribute to an early event of gastric cancer development, and it further
suggests that selective inhibition of COX-2 may provide a chemopreventive effect
against gastric carcinogenesis.
PMID- 10690534
TI - p53 gene mutations are associated with shortened survival in patients with
advanced non-small cell lung cancer: an analysis of medically managed patients.
AB - Mutations in the p53 gene are common in many cancers. Nevertheless, the
relationship between mutations of this tumor suppressor gene and patient survival
in non-small cell lung cancer (NSCLC) remains unclear. Interpretation of prior
studies of patient outcomes are complicated by the inclusion of both surgical and
nonsurgical patients. To better isolate the potential effects of p53 gene
mutations per se on tumor progression, we chose to examine patients with advanced
disease in whom surgery was not performed (stages IIIA, IIIB, and IV). We have
used PCR-denaturing gradient gel electrophoresis, a sensitive and specific method
for the detection of a variety of p53 mutations in cytology or biopsy specimens,
to evaluate the prognostic significance of p53 gene mutations in nonsurgical
patients with advanced NSCLC. In 70 consecutive medical patients, p53 mutations
were found in 29 cases (41%) at the time of initial diagnosis. Followed
prospectively, patients with p53 mutations had a significantly reduced survival
time after diagnosis than those without mutations (median survival, 17 versus 39
weeks; P = 0.0003) independent of other clinical factors. This abbreviated
survival occurred in both patients who received chemotherapy (n = 39, P = 0.002)
or best supportive care (n = 31, P = 0.018). These results indicate that
mutations of the p53 gene in patients with NSCLC who do not undergo surgical
resection portends a significantly worse prognosis.
PMID- 10690535
TI - Serum tumor marker CA 125 is an early and sensitive indicator of veno-occlusive
disease in children undergoing bone marrow transplantation.
AB - Veno-occlusive disease (VOD) is a potentially lethal complication of patients
undergoing bone marrow transplantation (BMT). The diagnosis of VOD is currently
based on clinical signs and unspecific laboratory findings. CA 125 is an
oncofetal antigen used as a tumor marker in various malignancies, especially in
those originating from the female reproductive tract or gastrointestinal organs,
whereas serum CA 125 levels are not increased in hematological malignancies.
Several pathophysiological alterations occurring in VOD may lead to elevations in
serum CA 125 levels. Therefore, we explored the behavior of this marker as a
diagnostic tool in VOD. Twenty-nine pediatric transplant patients were studied.
Eight patients (28%) developed clinical VOD, and a significant increase in serum
CA 125 was noted in all of them. During the 7 days preceding the diagnosis of
VOD, an increase of at least 57% in serum CA 125 from the pre-BMT value was
observed in 6 (86%) of 7 of the evaluable patients with VOD. In contrast, a
similar increase was noted in only 6 of the 21 non-VOD patients during the post
BMT period of 30 days. Accordingly, the sensitivity and specificity of serum CA
125 for predicting or detecting VOD were 86% and 71%, respectively. The serum
levels of CA 125 were not affected by the presence of Graft-versus-Host Disease
(GvHD) or a septic infection. In conclusion, serum CA 125 is of value as an early
marker of VOD in children undergoing BMT.
PMID- 10690536
TI - Mutational analysis of the transforming growth factor beta receptor type II gene
in hereditary nonpolyposis colorectal cancer and early-onset colorectal cancer
patients.
AB - Somatic mutations in the transforming growth factor beta receptor type II (TGF
beta RII) gene have been observed in various human cancers showing microsatellite
instability. Most of the mutations observed were additions or deletions of the
mononucleotide repeat sequence present in TGF-beta RII coding region, suggesting
that the TGF-beta RII may be a target gene of genomic instability in
tumorigenesis. Recently, we reported germ-line frameshift mutations in the
mononucleotide repeat sequence of the hMSH6 gene, which is believed to be one of
the target genes of genomic instability in tumorigenesis, suggesting the
possibility of germ-line mutation in mononucleotide repeat sequences. Moreover,
one case of germ-line mutation in the TGF-beta RII gene was identified in a
hereditary nonpolyposis colorectal cancer (HNPCC) kindred, indicating the
involvement of TGF-beta RII inactivation in tumorigenesis of HNPCC. However, germ
line mutation analysis of all of the coding sequences and the mononucleotide
repeat sequence of the TGF-beta RII in HNPCC patients has not yet been fully
elucidated. Therefore, to further investigate the presence of germ-line
mutations, we screened all of the coding region sequences and mononucleotide
repeat sequence of TGF-beta RII from 35 HNPCC, 44 suspected HNPCC, and 45
sporadic early-onset colorectal cancer patients. However, no pathogenic mutations
other than silent mutations, introgenic mutation, and polymorphisms were
identified. Two silent mutations at codons 309 (ACG to ACA) and 340 (CAT to CAC)
in the kinase domain located in exon 4 were detected. A 1-bp cytidine deletion
was observed 6 bases from the 3' end of intron. Two polymorphisms were identified
at codon 389 (AAC to AAT) and at the fourth-to-last base in intron 3. The
polymorphism at codon 389 was more frequent in HNPCC (20%; 7 of 35) and suspected
HNPCC patients (18%; 8 of 44) than in nonmalignant control group (10%; 5 of 50).
Moreover, the frequency was significantly higher in early-onset colorectal cancer
patients (31%; 14 of 45). This is the first report of a different frequency of
polymorphism in HNPCC, suspected HNPCC, early-onset colorectal cancer patients,
and healthy normal individuals. This result suggests that: (a) germ-line mutation
of the TGF-beta RII gene may be a rare event during tumorigenesis in HNPCC and
sporadic early-onset colorectal cancer; (b) the mononucleotide repeat sequence of
the TGF-beta RII gene is an apparent target of genomic instability but not of
germ-line mutation; and (c) the polymorphism of codon 389 (AAC to AAT) is
frequent, especially in early-onset colorectal cancer patients, in which it is
more frequent than in control group.
PMID- 10690537
TI - Topological analysis of p21WAF1/CIP1 expression in esophageal squamous dysplasia.
AB - In the normal stratified squamous epithelium of the esophagus, only the third to
the fifth layers of cells express the cyclin-dependent kinase inhibitor
p21WAF1/CIP1 (p21). Using immunohistochemical staining, we examined the
topological distribution of cells expressing p21, p53, Ki67, and cytokeratin 10
(CK10), a differentiation marker of esophageal squamous cell carcinoma (SCC), in
25 superficial SCCs and 72 dysplastic lesions of the esophagus. Image analysis of
p21, p53, and Ki67 expression was also performed in 48 dysplastic lesions. In
superficial SCCs, although Ki67- and p53-expressing cells were mainly distributed
in the deep layers of tumors despite tumor differentiation, the distribution of
p21 correlated with tumor differentiation. In dysplastic lesions, p53- and Ki67
coexpressing cells tended to locate in the same layers and expand in the lower
layers of epithelium with the progression of dysplasia. p21-expressing cells
shifted to the upper layers of the epithelium with the progression of dysplasia.
However, this change was heterogeneous; in some lesions, p21-expressing cells
were confined to the superficial layers of atypical cells (confined type),
whereas in others, p21-overexpressing cells were scattered among atypical cells
(scattered type). CK10 expression was observed in 25% of dysplastic lesions, and
the frequency of CK10 expression was significantly higher in the scattered than
in the confined type. Our results suggest that esophageal squamous dysplasia
represents the earliest pathological process in esophageal squamous
carcinogenesis. Our results also suggest that differentiation of esophageal SCC
is determined at the stage of dysplasia, and that p21 plays a critical role in
the differentiation process.
PMID- 10690538
TI - Expression of protein gene product 9.5 and tyrosine hydroxylase in childhood
small round cell tumors.
AB - Small round cell tumors of childhood can be histologically ambiguous, can require
tumor markers for an accurate diagnosis, and include neuroblastoma, peripheral
primitive neuroectodermal tumor (pPNET), Ewing's sarcoma (ES), lymphoma, and
rhabdomyosarcoma. Because the cell type of origin for ES remains controversial,
characterizing gene expression in ES can provide diagnostic markers and lead to
better understanding of tumor biology. We studied RNA expression of the neuronal
genes protein gene product 9.5 (PGP 9.5) and tyrosine hydroxylase (TH) by
Northern analysis in cell lines and tissue from small round cell tumors. PGP 9.5
showed strong expression in 17 of 17 neuroblastoma cell lines, 9 of 9 pPNET cell
lines, and 11 of 11 ES cell lines. PGP 9.5 was weakly expressed in 1 of 1
alveolar rhabdomyosarcoma cell lines but not in 1 of 1 embryonal
rhabdomyosarcomas, and weak expression was seen in 1 of 7 leukemia cell lines. In
tumor tissue, all 12 neuroblastomas expressed PGP 9.5, as did all 7 pPNET and all
7 ES. PGP 9.5 was very weakly expressed in 6 of 9 rhabdomyosarcomas and 1 of 9
lymphomas. TH was expressed only in neuroblastomas, and no TH expression was seen
in cell lines or tissue from other tumors. As high expression of PGP 9.5 was only
found in neural tumors; PGP 9.5 expression by ES provides further evidence for a
neural origin of this tumor, whereas TH expression is highly specific for
neuroblastomas. PGP 9.5 expression should allow sensitive detection of minimal
residual disease for ES and pPNET using reverse transcription-PCR, and the
variability in TH and PGP 9.5 expression levels in neuroblastomas indicates that
expression of both genes should be used for monitoring minimal residual disease
by reverse transcription-PCR.
PMID- 10690539
TI - Prognostic implication of microsatellite alteration profiles in early-stage non
small cell lung cancer.
AB - Development of non-small cell lung cancer (NSCLC) is a result of multiple
accumulated genetic abnormalities. Profiles of genetic abnormalities may
determine tumor behavior and impact on patient outcome. We used microsatellite
markers at 3p14, 9p21, and 10q24 to analyze tumor samples from 91 patients with
pathologically confirmed stage I NSCLC for microsatellite alterations. Loss of
heterozygosity at any single locus was not significantly associated with length
of survival. However, patients whose tumors had microsatellite instability (MI)
at 10q24 had shortened disease-specific survival. Among 31 such patients, 32% (10
of 31 patients) had died of the disease within 5 years after surgery compared
with 16% (9 of 58 patients) without MI at 10q24 (P = 0.07). Interestingly, in the
adenocarcinoma subtype, 71% (5 of 7 patients) of the patients with MI at 10q24
succumbed to the disease as compared with only 12% (3 of 26) of the
adenocarcinoma patients without such MI (P < 0.001), suggesting the presence of
distinct mechanisms in tumorigenesis among different subtypes of lung cancer. It
has been noticed that certain microsatellite alteration profiles provide
additional values for risk assessment. Of 23 patients who had MI at 10q24 and an
alteration at 3p14, 39% (9 of 23 patients) died of the disease within 5 years as
compared with only 15% (10 of 66 patients) of the patients without such a profile
(P = 0.02). Strikingly, among the 22 patients with no alteration at any loci
tested or with loss of heterozygosity at 10q24 and retention of at least one of
the other two loci, none died of lung cancer within 5 years after surgery,
whereas 28% (19 of 67 patients) of the patients outside these profiles did so (P
= 0.01). Our results support the hypothesis that microsatellite alterations can
be used as biomarkers for the genetic classification of pathological stage I
NSCLC, which may in turn influence treatment decisions dependent on an accurate
forecast of patient survival time.
PMID- 10690540
TI - Neurotensin receptor-1 mRNA analysis in normal pancreas and pancreatic disease.
AB - By autoradiography, neurotensin (NT) binding is specifically detectable in
pancreatic cancer, but not in the normal pancreas, chronic pancreatitis (CP), or
other pancreatic disorders. In the present study, we investigated whether this is
due to NT receptor-1 (NTR-1) mRNA up-regulation and whether NTR-1 mRNA could also
be used as a specific diagnostic marker and treatment target in pancreatic
cancer. Fifteen normal pancreas tissue samples, 20 CP samples, and 30 pancreatic
cancer samples were studied. Expression and localization of NTR-1 mRNA was
investigated by Northern blot analysis and in situ hybridization. Furthermore,
consecutive tissue sections were analyzed for NTR-1 mRNA expression and NT
binding. By Northern blot analysis, NTR-1 mRNA expression was 4.4-fold (P < 0.01)
and 3.0-fold (P < 0.01) higher in pancreatic cancer and CP tissue samples,
respectively, compared with normal controls. There was no difference in NTR-1
mRNA levels between CP and cancer samples (P > 0.05). In pancreatic cancer, the
NTR-1 mRNA levels were higher in advanced tumor stage (stages III and IV) than
early tumor stage (stages I and II; P < 0.05), but no difference was found
between well/moderately differentiated (grades 1 and 2) and poorly
differentiated/undifferentiated cancers (grades 3 and 4; P > 0.05). By in situ
hybridization, NTR-1 mRNA signals were weakly present in the cytoplasm of acinar
and ductal cells of the normal pancreas. Moderate to intense NTR-1 mRNA signals
were present in the cytoplasm of acinar cells dedifferentiating into tubular
complexes and degenerating acinar cells of CP samples. In the cancer samples, NTR
1 mRNA was moderately to intensely expressed in the cytoplasm of cancer cells.
When on consecutive tissue sections NTR-1 mRNA expression was compared with the
presence of NTR-1, measured by receptor autoradiography, a correlation was found
in carcinomas but not in CP samples, in which no receptors were detectable by
autoradiography. The enhanced expression of NTR-1 mRNA in pancreatic cancer cells
further suggests that neuroendocrine hormones might modulate pancreas cancer cell
behavior. However, its relatively high levels in CP excludes NTR-1 mRNA as a
specific parameter for pancreatic cancer and for the differentiation of
pancreatic cancer from CP.
PMID- 10690541
TI - Vascular endothelial growth factor expression in untreated osteosarcoma is
predictive of pulmonary metastasis and poor prognosis.
AB - To investigate the clinical significance of vascular endothelial growth factor
(VEGF) in osteosarcoma, we immunohistochemically stained biopsy specimens of 27
primary osteosarcomas using an antibody against VEGF and evaluated the
correlation between the expression of VEGF and local density of CD34-positive
microvessels, clinicopathological variables, and survival of patients. VEGF
staining was positive in 17 tumors (63.0%) in which the density of CD34-positive
microvessels was significantly higher than that in VEGF-negative 10 tumors (P <
0.05). In terms of clinicopathological variables, there was no correlation
between the expression of VEGF and histological subtype, stage, or response to
neoadjuvant chemotherapy, or, strikingly, to the development of pulmonary
metastasis (89% of VEGF-positive tumors versus 10% of VEGF-negative tumors; P <
0.0003). Moreover, patients with a VEGF-positive tumor were poorer in both
disease-free survival (P < 0.001) and overall survival (P < 0.03) compared to
those with a VEGF-negative tumor. These findings strongly suggest that VEGF
expression in untreated osteosarcoma is predictive of pulmonary metastasis and
poor prognosis in patients who underwent aggressive therapy and also provide the
basis for a therapeutic strategy targeting angiogeneic property of osteosarcoma.
PMID- 10690542
TI - Cathepsin B, a prognostic indicator in lymph node-negative breast carcinoma
patients: comparison with cathepsin D, cathepsin L, and other clinical
indicators.
AB - New prognosticators are needed for breast cancer patients after the initial
surgical treatment to make therapeutic decisions that ultimately will affect
their DFS. These consist of specific proteolytic enzymes including lysosomal
endopeptidases. In this study, the activity and protein concentrations of
cathepsins (Cats) D, B, and L were measured in 282 invasive breast tumor
cytosols. These potential biological prognostic indicators were compared with
other histopathological parameters, such as tumor size, lymph node involvement,
tumor-node-metastasis stage, histological grade, DNA analysis, and steroid
receptors. CatD protein concentration correlated with lymph node involvement.
CatB and CatL levels correlated significantly with Scarf-Bloom-Richardson
histological grade and were also higher in estrogen-negative tumors, and CatB was
higher in larger tumors. As prognostic markers, CatB concentration was
significant for increased risk for recurrence in the entire patient population
and specifically also in lymph node-negative patients as follows: high CatB
concentration (above 371 micrograms/g) in tumor cytosols was significant (P <
0.00) for high risk of recurrence but was of only borderline prognostic
significance (P < 0.06) for overall survival of all patients. In lymph node
negative patients, CatB (above 240 micrograms/g, P < 0.003) was highly
significant for recurrence-free survival, followed by CatL (above 20
micrograms/g, P < 0.049) and CatD (above 45 nmol/g, P < 0.044) concentrations.
For overall survival of node-negative patients, only CatB was a significant (P <
0.014) prognosticator. We conclude that CatB is useful as a prognostic indicator
in lymph node-negative patients. This suggests that selective adjuvant therapy
should be applied in this lower risk group of patients when high levels of CatB
are determined.
PMID- 10690543
TI - In multiple myeloma, circulating hyperdiploid B cells have clonotypic
immunoglobulin heavy chain rearrangements and may mediate spread of disease.
AB - DNA aneuploidy characterizes a proportion of malignant bone marrow (BM)-localized
plasma cells in multiple myeloma (MM). This analysis shows that for most MM
patients, circulating clonotypic B cells in MM are also hyperdiploid. Although
all normal B cells and some malignant B cells are diploid, hyperdiploidy is
likely to be exclusive to those that are malignant. Hyperdiploid MM B cells
express CD34 and have clonotypic IgH transcripts, confirming them as part of the
malignant clone. For MM, 92% (70/76) of patients had a DNA hyperdiploid subset [5
30% of peripheral blood mononuclear cells (PBMCs)] of CD19+ B cells. All CD19+
PBMCs in MM expressed CD19 and IgH variable diversity joining (VDJ) transcripts,
confirming them as B cells. DNA aneuploid cells were undetectable in T or B
lymphocytes from normal blood, spleen or thymus, or in blood from patients with B
chronic lymphocytic leukemia. In MM, untreated patients had the highest DNA index
(1.12). DNA hyperdiploid PBMCs were most frequent among untreated patients and
were significantly reduced after chemotherapy. Diploid B cells were significantly
more frequent after chemotherapy than at diagnosis. Of the hyperdiploid PBMCs, 81
+/- 3% expressed CD34 and CD19. In contrast to circulating CD34+ B cells, CD34- B
cells in MM are diploid. In MM, unlike hyperdiploid PBMC B cells, hyperdiploid BM
plasma cells lack both CD34 and CD19, suggesting that loss of CD34 correlates
with differentiation and BM anchoring. In situ reverse transcription-PCR of the
CD34+ (hyperdiploid) and CD34- (diploid) PBMC B-cell subsets was performed using
patient-specific primers to amplify clonotypic IgH VDJ transcripts. Confirming
previous work, CD34+ hyperdiploid MM PBMCs were clonotypic (86 +/- 5%). In
contrast, CD34- diploid MM PBMCs had few monoclonal cells (4.8 +/- 2%). The lack
of hyperdiploidy, together with the relative absence of cells having clonotypic
transcripts, suggests these polyclonal CD34- B cells are normal. After culture in
colchicine to arrest mitosis, hyperdiploid B cells were reduced and MM B cells
accumulated in a diploid G2-M, suggesting that hyperdiploid in MM may represent a
transient S-phase arrest rather than an aneuploid G0 phase. The DNA hyperdiploidy
of CD34+ clonotypic B cells suggests these cells may be clinically important
constituents of the myeloma clone and that they may play a direct role in the
spread of myeloma.
PMID- 10690544
TI - Significance of neuron-specific enolase levels before and during therapy for
small cell lung cancer.
AB - The level of serum neuron-specific enolase (NSE) has been implicated as a
prognostic factor for patients with small cell lung cancer (SCLC). A prospective
evaluation was undertaken to assess the prognostic significance of pretreatment
NSE and treatment-induced minimum NSE values in patients with SCLC. Patients from
two Phase III North Central Cancer Treatment Group trials [one for patients with
extensive stage SCLC and one for patients with limited stage SCLC] were asked to
enter this laboratory correlational trial. Both trials included treatment with
four to six cycles of etoposide and cisplatin, and 121 patients (71 extensive
stage SCLC and 50 limited stage SCLC) were entered into the present study of NSE.
Pretreatment NSE values and treatment-induced minimum NSE values were independent
predictors of time to progression and survival in multivariate analysis. Hazard
rate modeling allowed the formulation of specific relationships of NSE to time to
progression and survival. Pretreatment NSE levels inversely correlated with time
to progression and survival in these patients with SCLC. Pretreatment NSE
accounted for 28% of the variance in survival. Both pretreatment NSE and
treatment-induced minimum NSE were independent prognostic predictors of time to
progression and survival.
PMID- 10690545
TI - Alterations in the expression of the DNA repair/redox enzyme APE/ref-1 in
epithelial ovarian cancers.
AB - The DNA base excision repair pathway is responsible for the repair of alkylation
and oxidative DNA damage. A crucial step in the base excision repair pathway
involves the cleavage of an apurinic/apyrimidinic (AP) site in DNA by an AP
endonuclease (APE). The major AP endonuclease in mammalian cells is APE/ref-1, a
multifunctional enzyme that acts not only as an AP endonuclease but as a redox
modifying factor for a variety of transcription factors. The purpose of this
study was to determine the expression of APE/redox factor-1 (ref-1) in ovarian
tissues, particularly ovarian cancers. Formalin-fixed, paraffin-embedded
specimens of ovarian tissues (normal, various benign conditions, and epithelial
cancers) were studied using both polyclonal and monoclonal antibodies to APE/ref
1. The relationship between APE/ref-1 protein levels and DNA repair activity was
studied in ovarian Hey and Hey-C2 cell lines using Western blot and a specific AP
site oligonucleotide cleavage assay. Hey and Hey-C2 cells were fractionated, and
the nuclear and cytoplasmic extracts were quantitated for protein levels and
assessed for APE/ref-1 with Western blot. Normal ovarian tissues consistently
demonstrated strong nuclear staining of the surface epithelium, epithelial
inclusions, corpora lutea and albicantia, and stroma. Cytoplasmic staining was
absent. A similar pattern was seen for benign conditions including endometriosis.
Low malignant potential ovarian cancers stained in a pattern similar to normal
ovarian and nonneoplastic tissues; however, two specimens also had areas of
cytoplasmic staining. Epithelial ovarian cancers were remarkably different from
all other ovarian tissues studied. Both nuclear and cytoplasmic staining of the
malignant epithelium were seen and ranged from strong to weak, often with
considerable staining heterogeneity within the same tumor. The AP-site
oligonucleotide cleavage assay indicated that APE/ref-1 protein levels correlate
well with DNA repair activity. The increased levels of APE/ref-1 in the Hey-C2
cells was mainly attributable to increased cytoplasmic enzyme. APE/ref-1
immunoreactivity is altered in malignant ovarian tumors. Further studies will
determine whether the altered expression and subcellular location reflect changes
in redox regulatory functions.
PMID- 10690546
TI - Bladder cancer: allelic deletions at and around the retinoblastoma tumor
suppressor gene in relation to stage and grade.
AB - Inhibition of the retinoblastoma tumor suppressor gene (RB) is probably important
in the pathogenesis of urinary bladder cancer. Little information is available
concerning allelic loss on 13q11 to 13q32 and its relation to grade and stage. In
a population-based study, freshly frozen tissue was collected from all new cases
of urinary bladder cancer in the Stockholm region during 1995-1996. Here we
report the occurrence of loss of heterozygosity (LOH) at seven sites in 13q11 to
13q32 as analyzed in 236 cases by a fluorescent multiplex PCR-based on tumor DNA
and peripheral blood. For each site, about 30% of the cases were not informative
because of homozygosity. Replication errors were detected in 4% (17 cases). LOH
was found in 21 (at 13q11-12.1) to 32% (at 13q14.3 in RB) of the informative
cases. A correlation was found between the prevalence of LOH at all observed loci
and stage and grade, respectively, and it was statistically significant for
13q14.3. LOH at RB was found in Ta as well as grade 1 tumors. Also, a
statistically significant correlation was found between the number of loci with
LOH at 13q and tumor stage and grade, respectively. Typically an altered RB
function is related to the expected clinical course of urinary bladder cancer,
but allelic loss including the gene also occurs in low grade and low stage
tumors. An altered RB function probably is not necessary for a malignant
transformation of urothelial cells. The causal direction of the relation between
the quantity of the deleted DNA and tumor aggressiveness is not clear.
PMID- 10690547
TI - Prediction of clinical outcome from primary tamoxifen by expression of biologic
markers in breast cancer patients.
AB - The aim of this study was to evaluate pretreatment clinical features and
biological markers together with changes in these factors as predictors of
response and relapse in patients receiving tamoxifen for primary breast cancer.
Fine-needle aspiration cytology of the primary breast cancer was performed before
tamoxifen treatment in 54 patients and repeated after therapy on day 14, day 60,
or on both days in a subset of 35 patients. These samples were evaluated for
estrogen receptor (ER), progesterone receptor (PgR), Ki67, S-phase fraction and
ploidy. The overall response to tamoxifen was 57% (31 of 54 patients).
Pretreatment ER and PgR significantly predicted for response by univariate
analysis (P < 0.0001 and P < 0.003, respectively). By multivariate analysis, ER
expression was the only independent predictor of response, and it was associated
with 27 times the likelihood of response (95% confidence interval, 6-136).
Increase in PgR and decrease in Ki67 on day 14 significantly predicted for
response to tamoxifen (P < 0.03 and P < 0.04, respectively). Lack of ER, clinical
node-positive disease, and failure to decrease Ki67 on day 14 were significantly
associated with increased risk of relapse (P < 0.05). By multivariate analysis,
ER expression was the only independent predictor of relapse (P < 0.005).
Pretreatment and early changes in molecular marker expression may assist in the
prediction of response and clinical outcome in primary breast cancer patients
receiving tamoxifen.
PMID- 10690548
TI - Enhancement of angiogenesis, tumor growth, and metastasis by transfection of
vascular endothelial growth factor into LoVo human colon cancer cell line.
AB - The expression of vascular endothelial growth factor (VEGF), a highly potent
angiogenic molecule, is thought to be correlated with the development of colon
cancer; however, direct evidence for a role of VEGF in metastasis is lacking.
This study was designed to more directly establish the role of VEGF in the growth
and metastasis of human colon cancer using a genetically engineered cancer cell
line. A stable VEGF gene-transfected human colon cancer cell line, LoVo, was made
by genetic manipulation using eukaryotic expression constructs designed to
express the complete VEGF121 cDNA in the sense orientation. Transfected clones
were screened for VEGF121 mRNA expression by Northern blot analysis and for
VEGF121 protein expression by Western blot analysis. Consequently, we obtained
S17 cells that expressed a high level of both VEGF mRNA and VEGF protein. A
vector-transfected clone (V7 cell) was used as a control. The experiment with the
dorsal air sac method revealed that S17 cells elicited a stronger directional out
growth of capillaries than V7 cells. S17 cells formed faster-growing tumors than
did V7 cells when xenografted s.c. into nude mice, although there was no
significant difference in their in vitro proliferation. Tumors derived from S17
cells had more vascularity, as assessed by counting capillary vessels after
staining with factor VIII, than did tumors derived from V7 cells (P < 0.05). With
regard to the metastatic potential, S17 cells exhibited a higher capacity for
both hepatic metastasis after the splenic portal inoculation and peritoneal
dissemination after i.p. injection than did V7 cells. However, S17 cells showed
no apparent metastasis, despite their rapid growth after orthotopic implantation.
In conclusion, the present study showed clearly that VEGF plays an important role
in cancer growth due to stimulation of angiogenesis by accelerating cell growth
after reaching the target organs.
PMID- 10690549
TI - The combined use of an immunotoxin and a radioimmunoconjugate to treat
disseminated human B-cell lymphoma in immunodeficient mice.
AB - Immunoconjugates (ICs) consist of a targeting moiety and a toxic moiety and have
the specificity that traditional cancer therapy lacks. At appropriate doses, ICs
are safe and effective in treating various cancers in experimental animals and in
humans. However, because cures are rarely achieved using single agents, regimens
involving combinations of agents with different mechanisms of action must be
evaluated. In this study, we explored the efficacy and toxicity of a combination
of two IC therapies, radioimmunotherapy (RIT) and immunotoxin (IT) therapy, to
treat advanced, disseminated human lymphoma in immunodeficient mice. We proposed
to use the bystander effect of RIT to reduce large tumor burdens, followed by an
IT to eliminate residual tumor cells. Our results indicate that, when used alone,
both RIT and IT therapy were safe and effective, but not curative. When the two
therapies were combined, efficacy and toxicity became dependent on the temporal
order of administration. Thus, with the doses used in this study, when RIT was
administered after IT therapy, the regimen was curative. In contrast, when RIT
was administered before IT therapy, the combination was highly toxic or even
lethal. Both RIT and IT therapy induced pulmonary vascular leak, but with
different kinetics. When RIT was given prior to IT therapy, the pulmonary
vascular leak became life-threatening but not when the two agents were
administered in the reverse order.
PMID- 10690550
TI - Methionine depletion enhances the antitumoral efficacy of cytotoxic agents in
drug-resistant human tumor xenografts.
AB - Efficacy of chemotherapy is limited in numerous tumors by specific cellular
mechanisms that inactivate cytotoxic antitumoral drugs, such as ATP-dependent
drug efflux and/or drug detoxification by glutathione. In reducing ATP pools
and/or glutathione synthesis, it might be possible to enhance the efficacy of
drugs affected by such resistance mechanisms. Reduction of the ATP pool and
glutathione content is achievable in cancer cells by depleting the exogenous
methionine (Met) supply and ethionine. Thus, the rationale for the present study
was to use Met depletion to decrease the ATP and glutathione pools so as to
sensitize tumors refractory to cytotoxic anticancer drugs. Met depletion was
achieved by feeding mice a methionine-free diet supplemented with homocysteine.
The effects of Met depletion combined with ethionine and/or chemotherapeutic
agents were studied using human solid cancers xenografted into nude mice. TC71-MA
(a colon cancer) SCLC6 (a small cell lung cancer), and SNB19 (a glioma) were
found to be refractory to cisplatin, doxorubicin, and carmustine, respectively.
These three drugs are used to treat such tumors and are dependent for their
activity on the lack of cellular ATP- or glutathione-dependent mechanisms of
resistance. TC71-MA, SCLC6, and SNB19 were Met dependent because their
proliferation in vitro and growth in vivo were reduced by Met depletion.
Cisplatin was inactive in the treatment of TC71-MA colon cancer, whereas a
methionine-free diet, alone or in combination with ethionine, prolonged the
survival of mice by 2-fold and 2.8-fold, respectively. When all three approaches
were combined, survival was prolonged by 3.3-fold. Doxorubicin did not affect the
growth of SCLC6, a MDR1-MRP-expressing tumor. A Met-deprived diet and ethionine
slightly decreased SCLC6 growth and, in combination with doxorubicin, an
inhibition of 51% was obtained, with survival prolonged by 1.7-fold. Combined
treatment produced greater tumor growth inhibition (74%) in SCLC6-Dox, a SCLC6
tumor pretreated with doxorubicin. Growth of SNB19 glioma was not inhibited by
carmustine, but when it was combined with Met depletion, survival duration was
prolonged by 2-fold, with a growth inhibition of 80%. These results indicate the
potential of Met depletion to enhance the antitumoral effects of chemotherapeutic
agents on drug-refractory tumors.
PMID- 10690551
TI - Prolonged response to antisense cyclin D1 in a human squamous cancer xenograft
model.
AB - Local recurrence of squamous cell cancer (SCC) causes high morbidity and is often
readily accessible, making such patients potential candidates for gene therapy.
Cyclin D1 (CD1), critical in the G1-S transition in the cell cycle, is amplified
in 20-50% and overexpressed in up to 80% of head and neck SCC. Our earlier
studies indicated that CD1 expression increased with progression from low grade
to high grade dysplasia, and that treatment of established tumors with antisense
cyclin D1 (AS-cyclin D1) led to tumor regression during a one week evaluation
period. We hypothesized that: 1) CD1 expression increases with disease
progression to advanced SCC, and 2) AS-cyclin D1 therapy would lead to prolonged
tumor regression in a xenograft model of human SCC. CD1 expression, evaluated by
immunostain in 30 stage III/IV head and neck SCC, increased in the basal layer
from normal-dysplasia (P = 0.06) and from dysplasia-carcinoma (P = 0.004). In the
germinative layer CD1 expression increased from dysplasia-carcinoma (P = 0.002)
but not from normal-dysplasia. Western blotting of eight SCC and two transformed
keratinocyte cell lines demonstrated CD1 overexpression in 8/10 (80%) lines. An
11th cell line (A431) had previously been shown to overexpress cyclin D1. 8/9
(89%) cell lines overexpressing CD1 formed tumors in immunodeficient mice,
whereas 0/2 cell lines without CD1 overexpression formed a tumor. Three
established SCCs, one fast growing, one with moderate growth rate (with CD1
overexpression) and one slow growing (without increased CD1), shrank
significantly for 2-4 weeks after AS-cyclin D1 treatment, while tumors transduced
with control vector grew. Cyclin D1 expression increases in frequency with
disease progression, and antisense cyclin D1 was effective in a xenograft model
of human cancer, independent of tumor growth rate.
PMID- 10690552
TI - Characterization of an ovarian carcinoma cell line resistant to cisplatin and
flavopiridol.
AB - Flavopiridol, the first inhibitor of cyclin-dependent kinases to enter clinical
trials, has shown promising antineoplastic activity and is currently undergoing
Phase II testing. Little is known about mechanisms of resistance to this agent.
In the present study, we have characterized an ovarian carcinoma cell line [OV202
high passage (hp)] that spontaneously developed drug resistance upon prolonged
passage in tissue culture. Standard cytogenetic analysis and spectral karyotyping
revealed that OV202 hp and the parental low passage line OV202 shared several
marker chromosomes, confirming the relatedness of these cell lines.
Immunoblotting demonstrated that OV202 and OV202 hp contained similar levels of a
variety of polypeptides involved in cell cycle regulation, including cyclin
dependent kinases 2 and 4; cyclins A, D1, and E; and proliferating cell nuclear
antigen. Despite these similarities, OV202 hp was resistant to flavopiridol and
cisplatin, with increases of 5- and 3-fold, respectively, in the mean drug
concentrations required to inhibit colony formation by 90%. In contrast, OV202 hp
and OV202 displayed indistinguishable sensitivities to oxaliplatin, paclitaxel,
topotecan, 1,3-bis(2-chloroethyl)-1-nitrosourea, etoposide, doxorubicin,
vincristine, and 5-fluorouracil, suggesting that the spontaneously acquired
resistance was not attributable to altered P-glycoprotein levels or a general
failure to engage the cell death machinery. After incubation with cisplatin,
whole cell platinum and platinum-DNA adducts measured using mass spectrometry
were lower in OV202 hp cells than OV202 cells. Similarly, after flavopiridol
exposure, whole cell flavopiridol concentrations measured by a newly developed
high performance liquid chromatography assay were lower in OV202 hp cells. These
data are consistent with the hypothesis that acquisition of spontaneous
resistance to flavopiridol and cisplatin in OV202 hp cells is due, at least in
part, to reduced accumulation of the respective drugs. These observations not
only provide the first characterization of a flavopiridol-resistant cell line but
also raise the possibility that alterations in drug accumulation might be
important in determining sensitivity to this agent.
PMID- 10690553
TI - Mismatch repair and p53 independently affect sensitivity to N-(2-chloroethyl)-N'
cyclohexyl-N-nitrosourea.
AB - The contributions of defective mismatch repair (MMR) and the p53-response to cell
killing by N-(2-chloroethyl)-N'-cyclohexyl-N-nitrosourea (CCNU) were evaluated.
MMR defects were previously shown to be associated with CCNU sensitivity (G.
Aquilina et al., Cancer Res., 58: 135-141, 1998). Unexpectedly, eight MMR
deficient variants of the A2780 human ovarian carcinoma cell line were 3-fold
more resistant to CCNU than the MMR-proficient parental cells. The variants were
members of a preexisting subpopulation of drug-resistant A2780 cells. In addition
to deficient expression of the MMR protein hMLH1, an essential component of the
hMutL alpha repair complex, the variants exhibited alterations in the expression
of other genes that influence drug sensitivity. Although A2780 cells possess a
wild-type p53 gene, all of the clones contained a heterozygous G to T tranversion
at codon 172. This change resulted in a Val to Phe substitution and was
associated with a constitutive production of high levels of p53, which was
inactive as a transcriptional activator of bax and p21. The hMLH1/p53 defective
variants displayed a less prominent cell cycle arrest and reduced apoptosis after
CCNU treatment. In contrast, MMR-defective A2780 variants, which had a similar
hMutL alpha defect but retained a wild-type p53, did exhibit the expected CCNU
sensitivity. Expression of a dominant-negative p53val135 increased CCNU
resistance of both MMR-proficient and MMR-deficient A2780 cells. Thus, defective
MMR and p53 influence CCNU sensitivity in opposite directions. Their effects are
independent, and sensitization by defective MMR does not require a functional p53
response.
PMID- 10690554
TI - Induction of apoptosis in malignant B cells by phenylbutyrate or phenylacetate in
combination with chemotherapeutic agents.
AB - Phenylacetate (PA) and phenylbutyrate (PB) are aromatic fatty acids that are
presently undergoing evaluation as potential antineoplastic agents. In vitro, PA
and PB cause differentiation or growth inhibition of malignant cells. Clinical
trials of these drugs as single agents indicate that they are not
myelosuppressive; therefore, combinations with other chemotherapy agents may be
possible. The goals of this study were to determine whether PA and PB (a) are
cytotoxic to malignant B cells from patients with non-Hodgkin's lymphoma and B
cell chronic lymphocytic leukemia and (b) exhibit additive or synergistic
induction of apoptosis when administered to myeloma cell lines in combination
with conventional drugs. In the clinical specimens, cytotoxicity was measured by
the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and
percent apoptosis was measured using 7-aminoactinomycin D and flow cytometry.
Viability was decreased by > 50% in 7% (1/15) of non-Hodgkin's lymphoma samples
treated with 5 mM PA, 27% treated with 1 mM PB, and 60% treated with 2 mM PB.
Likewise, viability was decreased by > 50% in 44% (4/9) of chronic lymphocytic
leukemia samples treated with 5 mM PA, 67% treated with 1 mM PB, and 100% treated
with 2 mM PB. Studies in the myeloma cell lines demonstrated that PB treatment
induced activation of caspases 3, 7, and 9 accompanied by cleavage of their
substrates and internucleosomal DNA degradation. Combinations of PA or PB with
conventional drugs (cytarabine, topotecan, doxorubicin, etoposide, chlorambucil,
melphalan, fludarabine, carboplatin, and cisplatin) were examined for synergism
(combination index < 1 in median effect analysis) in inducing apoptosis of both
the MY5 and 8226 human myeloma cell lines. At concentrations that killed > 50% of
cells, most combinations were additive; however, PB was synergistic with
cytarabine, etoposide, and topotecan, with the combination index < 1 at each of
the 50, 75, and 95% apoptosis levels. These observations indicate that PA and PB
can induce apoptosis in malignant B cells and enhance the cytotoxicity of agents
used in the treatment of these malignancies.
PMID- 10690555
TI - Hairy cell leukemia, a B-cell neoplasm that is particularly sensitive to the
cytotoxic effect of anti-Tac(Fv)-PE38 (LMB-2).
AB - Anti-Tac(Fv)-PE38 (LMB-2) is a recombinant, single-chain immunotoxin composed of
the variable domains of the anti-Tac (anti-CD25) monoclonal antibody fused to a
truncated form of Pseudomonas exotoxin (PE). Until now, this agent has been
reported to be very cytotoxic toward T-cell but not B-cell leukemic cells freshly
obtained from patients and is being tested clinically in patients with CD25+
malignancies of both B- and T-cell origin. Hairy cell leukemia (HCL) is a B-cell
malignancy in which the cells are usually CD25+ and their ex vivo sensitivity to
LMB-2 was unknown. Malignant cells from the first HCL patient to be tested were
very sensitive to the cytotoxic effect of LMB-2 in vitro (IC50, 1.1 ng/ml), and
this patient responded clinically to LMB-2 administered systemically. Therefore,
we decided to assess the potential clinical utility of LMB-2 in other patients
with HCL. We tested fresh leukemic cells from nine additional CD25+ HCL patients.
LMB-2 was very cytotoxic ex vivo in all patients with IC50s as low as 0.5 ng/ml.
Malignant cells freshly obtained from patients with chronic lymphocytic leukemia
were also sensitive to LMB-2 but not as sensitive as cells from HCL patients.
These results indicate that CD25+ HCL is a B-cell neoplasm that is particularly
sensitive to LMB-2, and this agent may be useful in patients who have failed
standard therapies.
PMID- 10690556
TI - In vivo enhancement of tumor radioresponse by C225 antiepidermal growth factor
receptor antibody.
AB - Overexpression of epidermal growth factor receptor (EGFR) has been correlated
with tumor resistance to cytotoxic agents, including radiation (T. Akimoto et
al., Clin. Cancer Res., 5: 2884-2890, 1999), and thus is a candidate target for
anticancer treatment. This study investigated whether treatment with C225 anti
EGFR antibody would improve tumor response to radiotherapy. Nude mice bearing 8
mm-diameter A431 tumor xenografts in the hind leg were treated with C225
antibody, 18 Gy of single-dose local tumor irradiation, or both. C225 was given
i.p. at a dose of 1 mg/mouse 6 h before irradiation or 6 h before and 3 and 6
days after irradiation. Delay in tumor growth was the treatment end point. C225
dramatically improved the efficacy of local tumor irradiation, particularly when
multiple injections of C225 were administered. Tumor radioresponse was enhanced
by a factor of 1.59 by a single dose and by a factor of 3.62 by a doses of C225.
Histological analyses of tumors revealed that C225 caused a striking increase in
central tumor necrosis associated with hemorrhage and vascular thrombosis when
combined with radiotherapy. In addition, C225 induced heavy tumor infiltration
with granulocytes, increased tumor cell terminal differentiation, and inhibited
tumor angiogenesis. We conclude that C225 anti-EGFR antibody enhances tumor
radioresponse by multiple mechanisms that may involve direct and indirect actions
on tumor cell survival.
PMID- 10690557
TI - Regression of U-87 MG human glioblastomas in nude mice after treatment with a
cytotoxic somatostatin analog AN-238.
AB - Receptors for somatostatin (SST) found on brain tumors could be used for
targeting of chemotherapeutic agents. This study was conducted to investigate the
effects of targeted cytotoxic SST analogue AN-238, consisting of 2
pyrrolinodoxorubicin (AN-201), a potent derivative of doxorubicin (DOX) linked to
somatostatin analogue RC-121, on the growth of SST receptor-positive U-87 MG
human glioblastomas. Nude mice bearing U-87 MG xenografts received i.v. saline or
equimolar doses of AN-238 or AN-201 (150 nmol/kg). Experiments also included
groups that were administered RC-121 prior to the injection of AN-238, and groups
injected with AN-162, a cytotoxic SST analogue similar to AN-238 but containing
DOX instead of AN-201. Tumor volume, weight, and burden were determined. The
effect of AN-238 and AN-201 on the survival time of nude mice bearing
orthotopically implanted U-87 MG tumors was also evaluated. The binding of AN-238
to U-87 MG tumors was determined by radioreceptor assay and SST receptor (SSTR)
subtype by reverse transcription-PCR. Nineteen days after a single administration
of AN-238 the growth of U-87 MG tumors in nude mice was significantly inhibited
(P = 0.00168), whereas two injections of AN-238 produced the regression of tumors
(P = 0.0046). AN-201 was toxic and ineffective at the same dose. The antitumor
effect on AN-238 could be blocked by pretreatment of the tumor-bearing mice with
RC-121. The mean survival time of nude mice inoculated orthotopically with U-87
MG cells into the brain was significantly prolonged by treatment with AN-238 (P =
0.0099). AN-162 failed to inhibit significantly the growth of U-87 MG xenografts.
High affinity binding sites for SST and mRNA for SST-2 receptor subtype were
detected in U-87 MG tumors. Cytotoxic SST analogue AN-238 can be targeted to SST
receptors on U-87 MG human glioblastomas to produce powerful inhibition of
growth.
PMID- 10690558
TI - Overexpression of Bax enhances antitumor activity of chemotherapeutic agents in
human head and neck squamous cell carcinoma.
AB - Overexpression of the Bax protein in human head and neck squamous cell carcinoma
A253 cells was reported to result in an increased sensitivity to various
chemotherapeutic agents in vitro (Guo et al., Oncol. Res., 11: 91-99, 1999). In
the present study, the relationship between Bax expression and response to
chemotherapy was further investigated in vitro and in vivo model systems. For in
vitro study, A253, A253/Vec (pcDNA3 vector transfectant), and A253/Bax
(pcDNA3/Bax transfectant, expressing 50-fold higher Bax protein than A253 and
A253/Vec) cells were exposed to various concentrations of raltitrexed (a specific
thymidylate synthase inhibitor) and SN-38 (a topoisomerase I inhibitor) for 2 h,
and cell growth inhibition was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5
diphenyltetrazolium bromide clonogenic assay. Compared to A253/Vec, A253/Bax
cells exhibited 9.5- and 13.5-fold increases in sensitivity to raltitrexed and SN
38, respectively. For in vivo study, A253/Vec and A253/Bax tumor xenografts were
established by s.c. injection of tumor cells into nude mice. The antitumor
activity and toxicity of raltitrexed (i.v. push daily for 5 days) and irinotecan
(a prodrug of SN-38; i.v. push daily for 3 days) were evaluated. The maximum
tolerated doses of raltitrexed and irinotecan were 30 and 100 mg/kg/day,
respectively. At the maximum tolerated doses, minimal antitumor activity was
observed with raltitrexed, although irinotecan was more active than raltitrexed
against A253 or A253/Vec tumors. In contrast, both raltitrexed and irinotecan
were significantly more active against A253/Bax xenografts than against A253/Vec
xenografts; the yield for complete tumor regression (cure) was 40% and 100% with
raltitrexed and irinotecan, respectively, with no significant toxicity.
Furthermore, the observed increase of antitumor activity in A253/Bax tumors was
associated with an enhanced induction of apoptosis in vivo. The in vivo results
demonstrated a proof of the principal concept that selecting up-regulation of the
proapoptosis gene Bax can provide the basis for a greater therapeutic efficacy to
a variety of chemotherapeutic agents with different structures and mechanisms of
action.
PMID- 10690559
TI - Treatment of isografted 9L rat brain tumors with beta-5-o-carboranyl-2'
deoxyuridine neutron capture therapy.
AB - beta-5-o-Carboranyl-2'-deoxyuridine (D-CDU) is a nontoxic pyrimidine nucleoside
analogue designed for boron neutron capture therapy of brain tumors. In vitro
studies indicated that D-CDU accumulates to levels 92- and 117-fold higher than
the extracellular concentration in rat 9L and human U-251 glioma cells,
respectively, and persists for several hours at levels 5-fold higher than the
extracellular concentration. Furthermore, D-CDU was not toxic to rats injected
i.p. with up to 150 mg/kg. On the basis of these studies, D-CDU was evaluated as
a neutron capture therapy agent using rats bearing stereotactically implanted
intracranial 9L tumors at single i.p. doses of 30 mg/kg and 150 mg/kg of D-CDU
(20% 10B enriched), given 2 h before irradiation with thermal neutrons. Boron
concentrations in tumors 2 h after dosing were 2.3 +/- 1.6 and 7.4 +/- 1.3
micrograms boron/g tissue (mean +/- SD), corresponding to tumor/brain ratios of
11.5 +/- 3.6 and 6.8 +/- 2.0 micrograms boron/g tissue for the low and high
doses, respectively. All untreated animals died within 28 days, whereas half
survived at days 32, 55, and 38 for groups receiving neutrons only, 30 mg/kg D
CDU, and 150 mg/kg D-CDU, respectively. Odds ratios of all treatment groups
differed significantly from the untreated group (P < 0.002; logrank test). The
median survival time for the 30 mg/kg-treated group but not for the 150 mg/kg
treated group was significantly longer than for rats treated with neutrons only
(P = 0.036), which may correlate with the decreased tumor selectivity for D-CDU
observed at the higher dose. Additional pharmacodynamic studies are warranted to
determine optimal dosing strategies for D-CDU.
PMID- 10690560
TI - The topoisomerase I inhibitor DX-8951f is active in a severe combined
immunodeficient mouse model of human acute myelogenous leukemia.
AB - The severe combined immunodeficient (SCID) mouse model of human acute myelogenous
leukemia (AML) is a unique system for preclinical in vivo evaluation of the
activity and toxicity of new agents. The topoisomerase I (topo I) inhibitor
topotecan is active in patients with AML and myelodysplastic syndromes. DX-8951f
is a novel topo I inhibitor with more potent antitumor effects than topotecan or
CPT-11 in vitro. To study the in vivo activity of DX-8951f, 6-week-old female
SCID mice received injections into the tail vein with 2 x 10(7) exponentially
growing KBM-3 cells. In each experiment, three to five sets of five mice were
treated with DX-8951f doses ranging from 7.5 to 80 mg/kg and at schedules of 1,
3, and 5 days; a control set of five mice was treated with the drug vehicle
alone. One group received DX-8951f on day 7 of the inoculation with KBM-3 (early
treatment group). To study the activity of DX-8951f in advanced disease, a second
group was treated 1 month after the inoculation, when the animals were developing
symptoms (late-treatment group). The study end point was the duration of survival
until death from leukemia, which was assessed clinically and by the presence of
the human DQ alpha gene in tissue samples by PCR. Six experiments were conducted
with 170 animals. Survival was higher in both the early- and late-treatment
groups than in untreated controls, and the treated groups had significantly less
central nervous system disease. Significantly improved survival was observed in
animals treated early with 60 and 80 mg/kg as a single injection, with 15 and 20
mg/kg over 3 days, and with 7.5 and 10 mg/kg over 5 days. In the late-disease
model (treatment starting on days 28-35), improved survival was observed with a
single dose of 80 or 20 mg/kg over 5 days. Dose escalation was limited by
dilution problems at the 1-day schedule and by toxicity (mainly gastrointestinal)
of the prolonged schedules. Both efficacy and toxicity were dose schedule
dependent, increasing with higher doses and prolonged exposure. By establishing
the antileukemic activity of DX-8951f against human AML transplanted into SCID
mice at doses below the LD10, our data provide a rationale for clinical
evaluation of the drug in patients with AML and favor the use of prolonged
administration.
PMID- 10690562
TI - Glucose homeostasis in the micropremie.
AB - This article evaluates the current knowledge of the kinetics of glucose
homeostasis in the micropremie. Glucose production, glucose use, and glucose
oxidation are reviewed in detail. This article also evaluates the developmental
regulation of glucose homeostasis relative to some of the fundamental differences
known to exist in the neonate compared to the adult.
PMID- 10690561
TI - In vitro and in vivo activity of protein kinase C inhibitor chelerythrine
chloride induces tumor cell toxicity and growth delay in vivo.
AB - Although clonogenic or divisional death is the main mechanism by which DNA
damaging agents demonstrate antitumor activity, recent data indicate that
strategies specifically designed to trigger apoptosis may also prove to be useful
antitumor agents. Protein kinase C (PKC) isoenzymes are involved in the
regulation of cell proliferation, differentiation, and survival. Whereas
pharmacological inhibition of PKC activity triggers apoptosis in most mammalian
cells, cell line and tissue differences in sensitivities to these inhibitors
remain. Whereas PKC inhibitors have potential as antitumor agents, issue of
kinase specificity and solubility have remained obstacles to their clinical use.
In this report, we investigated the antitumor activity of the PKC inhibitor
chelerythrine chloride (chelerythrine), a selective inhibitor of group A and B
PKC isoforms. Chelerythrine exhibited cytotoxic activity against nine human tumor
cell lines tested in vitro. On the basis of the finding that radioresistant and
chemoresistant squamous cell carcinoma lines (HNSCC) undergo apoptosis rapidly
after treatment with chelerythrine in vitro, we assessed the effects of this
agent on p53-deficient SQ-20B HNSCC cells in vivo. The results demonstrate that
chelerythrine treatment of nude mice bearing SQ-20B is associated with
significant tumor growth delay. Significantly, treatment with chelerythrine
resulted in minimal toxicity. These findings demonstrate a potential for
chelerythrine as an antitumor drug against squamous cell carcinoma.
PMID- 10690563
TI - Protein metabolism in the extremely low-birth weight infant.
AB - Although extensive data are available on the impact of nutrient and protein
administration on growth, plasma amino acids, and nitrogen balance in the newborn
and growing infants, relatively few studies have carefully examined the dynamic
aspects of protein metabolism in vivo and particularly in the micropremie or ELBW
infant. These studies show that the very preterm infants, either because of
immaturity or because of the intercurrent illness, have high rates of protein
turnover and protein breakdown. This high rate of proteolysis is not as
responsive to nutrient administration. Intervention strategies aimed at promoting
nitrogen accretion, such as insulin, human growth hormone, or glutamine, have not
thus far resulted in enhanced protein accretion and growth. This may be, in part,
due to limitations in delivery of adequate calorie and nitrogen.
PMID- 10690564
TI - Lipid metabolism of the micropremie.
AB - Intravenous lipid emulsions often provide substance for the very low-birth weight
or extremely low-birth weight infant that need total parenteral nutrition. The
process used in this type of treatment as well as the effects of such treatment
are discussed at length in this article. Some of the main compounds of
representative lipid emulsions are listed and evaluated and the benefits and
consequences of their use are presented.
PMID- 10690565
TI - Essential fatty acid metabolism in the micropremie.
AB - Lipids are structural components of all tissues and are indispensable for cell
membrane synthesis. The brain, retina, and other neural tissues are particularly
rich in LCPUFAs, affecting neural structural development and function. LCPUFAs
serve also as specific precursors for eicosanoid production (prostaglandins,
prostacyclins, thromboxanes, and leukotrienes). These autocrine and paracrine
mediators are powerful regulators of numerous cell and tissue functions (e.g.,
thrombocyte aggregation, inflammatory reactions, and leukocyte functions,
vasoconstriction and vasodilatation, blood pressure, bronchial constriction,
uterine contraction). Dietary lipid intake affects cholesterol metabolism at an
early age and is associated with cardiovascular morbidity and mortality in later
life. Over recent years, the role of fatty acids in modulating signal
transduction and regulating gene expression have been described, emphasizing the
complex of fatty acid effects. Dietary fatty acids, especially LCPUFA, can have
significant effects in the modulation of developmental processes affecting the
clinical outcomes of extremely premature infants.
PMID- 10690566
TI - Vitamin metabolism and requirements in the micropremie.
AB - Vitamin metabolism and requirements are reviewed for the micropremie (1000 Pounds
g birthweight), for parenteral and enteral feedings. Recommendations are
presented in table format. Human milk fortifiers and special formulas for the
preterm infant are reviewed. For parenteral nutrition, only MVI Pediatric is
currently available in the United States. Two millimeters per kilogram is
recommended for the micropremie as the most satisfactory method of providing
supplemental vitamins in total parenteral nutrition solutions.
PMID- 10690567
TI - Trace elements of the micropremie.
AB - The current limited understanding of the ontogeny and mechanisms of the
metabolism of iron, zinc, copper, selenium, iodine, and manganese in the
micropremie are reviewed. The effects of early delivery on these processes are
considered, as are the suggested amounts of these trace elements required for
micropremies.
PMID- 10690568
TI - Water and electrolyte metabolism of the micropremie.
AB - There are five problem schemas presented in this article that indicate potential
contradictions in therapeutic goals: (1) shock and edema presenting upon
premature birth; (2) the hyperosmolar state, problematic in patients less than
750 g birth weight; (3) the respiratory distress syndrome and respiratory
failure, often complicated by patent ductus arteriosus; (4) bronchopulmonary
dysplasia, resulting from prematurity and mechanical ventilation; and (5) late
onset of hyponatremia, sometimes accompanied by growth failure in the recovering
premature. These five problems considered together comprise a developmental
continuum of illness and recovery, where appropriate fluid management has
recently been demonstrated to benefit outcomes greatly. Clinicians over the past
decade have encountered all of the fluid and electrolyte nightmares. Although
there are many different formulations for treating each of these scenarios,
recommending one approach for all patients is likely to be incorrect much of the
time.
PMID- 10690569
TI - Bone mineral metabolism in the micropremie.
AB - Environmental factors, nutritional supplies, hormonal status, diseases, and
treatments appear to affect postnatal skeletal growth and mineralization in VLBW
infants. Compared with their term counterparts, ELBW infants are at risk of
postnatal growth deficiency and osteopenia at the time of hospital discharge.
From recent data, DXA is becoming one of the reference techniques to evaluate
mineral status, whole-body composition, and effects of dietary manipulations on
weight gain composition and mineral accretion in preterm infants. Weight gain and
length increases need to be evaluated carefully during the first weeks of life,
in the intensive care unit and out of it, in the step down unit. Nutritional
survey is required to improve the nutritional supply and to maximize linear
growth. As the critical epoch of growth extends, during the first weeks or months
after discharge, follow-up and nutritional support need to be provided during the
first years to promote early catch-up growth and mineralization. Further studies
need to determine precisely the most optimal feeding regimen during this period
but also need to evaluate the long-term implications of such a policy on stature,
peak bone mass, and general health at adulthood.
PMID- 10690570
TI - Bilirubin and jaundice in the micropremie.
AB - Although it has been customary to treat neonatal jaundice at lower serum
bilirubin levels in low-birth weight infants than in term infants, the threshold
bilirubin levels and long-term benefits for early treatment of preterm infants
have not been validated. This article summarizes and evaluates existing evidence
and strategies for early treatment of bilirubin in micropremies and recommends a
conservative but flexible approach to early monitoring and phototherapy for
jaundice in extremely low-birth weight infants.
PMID- 10690571
TI - Energy expenditure in the extremely low-birth weight infant.
AB - Information about energy requirements of extremely low-birth weight infants is
sparse, despite the rapidly improving survival rates of this population.
Metabolizable energy intake can be estimated from energy balance studies and the
percentage of caloric intake that is actually absorbed by these infants is
approximately 87%. Data on energy expenditure in extremely premature infants is
limited; however, energy expenditure has been shown to increase with postnatal
age. Because both intake and expenditure are affected by multiple factors, there
is significant variability in estimates of the energy requirements in extremely
low-birth weight infants. At present, no valid recommendations can be made
regarding optimal energy requirements for the extremely low-birth weight infant,
except that their requirements probably exceed those of stable, growing very low
birth weight infants, currently estimated at 105 to 135 kcal.kg-1d-1.
PMID- 10690572
TI - Intravenous nutrition and postnatal growth of the micropremie.
AB - There is a growing body of evidence that early nutritional practices may affect
short-term growth and developmental outcome. In addition, they may play a role in
determining adult health and disease. There is much that needs to be learned
about safe and efficacious nutrient administration in the ELBW population; about
techniques to assess the effect of different nutritional strategies; and about
the long-term effects of these regimen or development outcome, growth, and
disease.
PMID- 10690573
TI - Enteral feeding of the micropremie.
AB - Clinical practice demands knowledge of gastrointestinal ontogeny and the factors
that affect our ability to use enteral feeding in the micropremie. The decisions
regarding milk type (when and how it should be given) are considered in the light
of current physiologic and clinical evidence. Special considerations apply in the
micropremie who is also small for gestational age and NEC must be avoided.
Trophic feeding now has an established role, allowing the infant to benefit from
enteral feeds even when full nutritive milk feeding is not possible.
PMID- 10690574
TI - Human milk feeding of the micropremie.
AB - There is increasing evidence that mother's milk is an appropriate feeding even
for LBW and VLBW infants. During early neonatal life, supplements in the form of
human milk fortifiers or single nutrients may be necessary to maintain an
adequate biochemical status especially for sodium, phosphorus, and protein. The
ideal amount and balance of supplemental nutrients to add to mother's milk for
small premature infants remain unknown. From research to date, it is clear that
growth responses to fortified mother's milk fed in early life may not be the most
important outcomes in relation to long-term growth and development. Infants who
receive human milk in early life may be at reduced risk for developing infections
and allergy as well as osteopenia and growth failure. Further studies are needed
to provide a better understanding of the role of human milk as the sole source of
nutrition in premature infants, especially the micropremie.
PMID- 10690575
TI - Personality disorders and depression: comorbidity.
AB - Depression and comorbid personality disorders relate to one another in three
distinct ways: 1) personality disorders may precede the development of depression
and render an individual vulnerable to depression; 2) depression may precede the
personality disorder and foster the development of the personality disorder; 3)
there may be an interface between personality disorders and depression, which has
been deemed depressive personality disorder. This article reviews data on the
comorbidity of depression, particularly chronic depression, and personality
disorders. This article also reviews data on the effect of comorbid personality
disorders on treatment for depression, and the effect that treatment for
depression has on personality disorders. Comorbid personality disorders generally
do not impede treatment for depression. Successful treatment for depression is
associated with improvement in personality disorders.
PMID- 10690576
TI - Factors differentiating personality-disordered individuals with and without a
history of unipolar mood disorder.
AB - The relationship between mood disorders and personality disorders has been of
longstanding interest to clinicians. Despite theoretical reasons to do so,
virtually no studies have examined factors that discriminate personality
disordered subjects with a history of mood disorder (PD/HMD) from personality
disordered subjects without a history of mood disorder (PD). This study examined
demographic variables, patterns of comorbidity, measures of life functioning,
personality traits, and early life experiences differentiating PD/HMD (n = 83)
from PD (n = 214). Diagnoses were assigned using structured clinical interviews
and a best-estimate procedure. The results suggest that subjects with borderline
personality disorder are more likely to have a life history of mood disorder than
are subjects with other personality disorders. In addition, PD/HMDs are more
likely to receive a diagnosis of anxiety disorder or alcoholism, to have lower
Global Assessment of Functioning (GAF) scores, and to have sought treatment than
PDs. On self-report measures of personality, PD/HMDs endorse higher levels of
trait anxiety and affective lability (e.g., Harm Avoidance, Neuroticism) than do
PDs. PD/HMDs are also more likely to report childhood physical and emotional
abuse than are PDs, and to describe their parents as using affectionless control.
No differences were found between Axis II clusters as a function of mood disorder
history. The discussion suggests a potential model in which early environmental
stress interacts with constitutional vulnerabilities to put individuals at an
increased risk for both mood and anxiety disorders as well as personality
disorders.
PMID- 10690577
TI - Relationship between depression and borderline personality disorder.
AB - The frequent occurrence of depressive symptoms in patients with borderline
personality disorder has generated considerable interest in the nature of the
relationship between borderline personality disorder and the depressive
disorders. Data from the perspectives of phenomenology, biology, family history,
course of illness, comorbidity patterns, and treatment response have been brought
to bear on the question. Reviews based on research available by 1985 and 1991,
respectively, arrived at differing conclusions: (1) that both disorders shared
common but non-specific sources, and (2) that the two disorders were unrelated
but co-occurred because of the high prevalence of each. Since the time of these
reviews, additional evidence has become available from a wider range of
biological investigations, better controlled comorbidity studies, studies of the
relationship of psychosocial stressors to the course of each disorder and
neuroimaging studies. In reviewing the more recent findings, we propose the less
parsimonious hypothesis that the disorders co-occur, both because they share some
common biological features and because the psychosocial sequella of each can
contribute to the development of the other.
PMID- 10690578
TI - Defense mechanisms and personality in depression.
AB - There is a longstanding belief that personality represents a structure that is
stable over time, and changes, if at all, very slowly. Nonetheless, clinical and
empirical evidence suggests that in patients with some Axis I disorders, the rate
of personality disorders using DSM criteria decreases after treatment, suggesting
that personality as assessed by phenomenological systems is state-dependent. An
alternative to the DSM phenomenological system of conceptualizing personality is
the dynamic concept of character, that is, a predictable pattern of both adaptive
and pathological defense mechanisms, and personality organization comprised of
object relations, ego strengths, and superego development. Data from this study
address the hypothesis that defense mechanisms and personality organization
remain relatively stable in patients treated for Axis I disorders, irrespective
of clinical improvement. Patients meeting DSM-IV criteria for major depressive
disorder (MDD) entered randomized, controlled medication trials. Defensive
functioning was evaluated with the Defense Style Questionnaire (DSQ) [Bond et
al., 1983: Arch Gen Psychiatry 40:333-338], and personality organization was
assessed with the Inventory of Personality Organization (IPO; Clarkin et al.,
unpublished), both at baseline and at the completion of the clinical trial. Data
were analyzed for whether an individual's pattern of defense mechanisms and
personality organization were stable over time regardless of response to
treatment of MDD. The question was also asked whether a predominant pattern of
defense mechanisms or level of personality organization predicts response to
treatment or dropout rate. Among treatment responders, nonresponders and drop
outs, baseline DSQ scores were similar except for "image-distorting" defenses,
which were significantly more prevalent among drop-outs compared to responders (P
= .016). Post-treatment DSQ values revealed a significant decrease in
"maladaptive" defenses (P = .01) in the entire sample, while intermediate and
"adaptive" defenses remained unchanged. This same pattern was found to hold true
in treatment responders. When comparing treatment responders and nonresponders at
the end of the trial, medication responders used significantly less "maladaptive"
defenses than did nonresponders (P = .003), and had a significantly higher, or
healthier level of "overall defensive functioning" (P = .04). Baseline and post
treatment IPO values did not show significant differences. Results of the study
address the question of whether there are personality characteristics that are
enduring and that can be appreciated irrespective of an Axis I disorder.
PMID- 10690579
TI - Co-occurrence of mood and personality disorders: a report from the Collaborative
Longitudinal Personality Disorders Study (CLPS).
AB - The purpose of this study was to examine the relationship of subtypes and
particular clinical features of mood disorders to co-occurrence with specific
personality disorders. Five hundred and seventy-one subjects recruited for the
Collaborative Longitudinal Personality Disorders Study (CLPS) were assessed with
the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and the
Diagnostic Interview for DSM-IV Personality Disorders (DIPD-IV). Percent co
occurrence rates for current and lifetime mood disorders with personality
disorders were calculated. Logistic regression analyses examined the effects of
clinical characteristics of depressive disorders (e.g., age at onset, recurrence,
symptom severity, double depression, and atypical features) on personality
disorder co-occurrence. In comparison with other DSM-IV personality disorders,
avoidant, borderline, and dependent personality disorders (PDs) were most
specifically associated with mood disorders, particularly depressive disorders.
Severity and recurrence of major depressive disorder and comorbid dysthymic
disorder predicted co-occurrence with borderline and to a lesser extent research
criteria depressive personality disorders. The results are consistent with the
view that a mood disorder with an insidious onset and recurrence, chronicity, and
progression in severity leads to a personality disorder diagnosis in young
adults.
PMID- 10690580
TI - Inflammatory bowel disease at the end of its first century.
PMID- 10690581
TI - The genetic background of inflammatory bowel disease.
AB - Available evidence indicates that genetic factors are essential in providing the
susceptibility to the majority of the various forms of inflammatory bowel disease
occurring in man. It is also clear that the genetic susceptibility to these
diseases is complex, and that more than one gene may predispose (the concept of
multilocus/oligogenic inheritance), and likely in different etiologic
combinations (the concept of genetic heterogeneity). Paradigms are now available
that should lead to the identification of a number of these predisposing genes.
These paradigms include the candidate gene approach, systematic genome wide
scans, and mouse human synteny. While genome wide scans are currently limited to
multiplex family linkage studies, both candidate genes and mouse human synteny
can be approached in either linkage or association paradigms. Eventually whole
genome association studies will be available as well. Identification of
inflammatory bowel disease predisposing genes should lead to their incorporation
in studies of natural history, investigation of environmental risk factors, and
especially utilization of genetic markers in clinical trials. This will allow us
to identify the best therapy available for the individual patient based on their
unique genetic constitution. With advances in molecular technology, the search
for genes influencing traits and diseases with a complex genetic background, such
as the inflammatory bowel diseases, has become a realistic task. Although
exogenous or infectious agents may contribute to the pathogenesis or may trigger
the onset of disease, and the immune system almost certainly mediates the tissue
damage, it is clear from available data that genetic factors determine the
susceptibility of a given individual to inflammatory bowel disease (reviewed
below). Thus, genetic studies are essential for the delineation of the basic
etiologies of the various forms of inflammatory bowel disease and thus can aid in
the development of radically new and specific therapies. In this review, we will
discuss the importance and complexity of genetic factors in inflammatory bowel
disease, methods and problems in the genetic dissection of complex traits, and
future directions of genetic studies in inflammatory bowel disease.
PMID- 10690582
TI - Inflammatory bowel disease: immunologic concepts.
AB - The past decade has been characterized by an enormous progress in the
understanding of the pathophysiology of chronic intestinal inflammation. Novel
drugs, which include tumor necrosis factor alpha binding proteins (i.e., the
monoclonal antibody infliximab), have been introduced into the therapeutic
management of Crohn's disease. With our increasing knowledge of disease
pathophysiology and the identification of key mediators, it is to be expected
that the efficacy of anti-inflammatory therapy will further increase. The
exploration of the genetic etiology of inflammatory bowel disease holds great
future promises.
PMID- 10690583
TI - Etiology and pathophysiology of inflammatory bowel disease--environmental
factors.
AB - Environmental factors play an important role in the pathophysiology of
inflammatory bowel disease. There is a strong and consistent association between
smoking and Crohn's disease, and between nonsmoking and ulcerative colitis.
Despite extensive research, the exact pathophysiological mechanisms for these
associations remain unclear. In spite of this, some clinical trials with nicotine
patches showed beneficial effects for the treatment of ulcerative colitis.
Associations of Crohn's disease and ulcerative colitis with other environmental
factors are weaker like the association with use of oral contraceptives or those
less well investigated such as the association with childhood hygiene. Most
studies suggesting a potential pathogenetic role of Mycobacterium
paratuberculosis or an effect of tuberculostatic therapy in Crohn's disease could
not be reproduced by others. Perinatal or childhood infections by viruses like
measles are heavily debated, but not proven to be causal for inflammatory bowel
disease. Coagulation disorders have been described as protecting from
inflammatory bowel disease, suggesting hypercoagulability to be a pathogenetic
factor. Some studies described that appendectomy may prevent the onset of
ulcerative colitis in man and mice. Other environmental factors such as hydrogen
sulfide, tonsillectomy, diet, blood transfusions, and Listeria also require
confirmation. There are, however, convincing data from genetic animal models and
twin studies that environmental factors as the intestinal bacterial flora
interact with susceptible hosts to cause inflammatory bowel disease. Inflammatory
bowel diseases have multifactorial etiologies, which require a differentiated
approach for treatment and prevention.
PMID- 10690584
TI - Diagnostic approach to IBD.
AB - Inflammatory bowel disease, with Crohn's disease and ulcerative colitis as the
two main disorders, is a heterogeneous group of disorders of unknown etiology.
Clinical initial presentation is sometimes misleading and causing diagnostic
delay which may be important. Identification of subgroups of patients on the
basis of genetic, immunologic and clinical markers will be important for exact
diagnosis, but also for new drug trials. The current diagnosis depends on
clinical, radiographic, endoscopic and laboratory data. The introduction of
serological markers such as pANCA and ASCA will allow an increase in the
diagnostic accuracy at initial diagnosis of inflammatory bowel disease and may
play a role in defining subgroups of the disease.
PMID- 10690585
TI - Complications of inflammatory bowel disease.
AB - Complications in inflammatory bowel disease determine the severity of disease as
well as the complexities of medical or surgical treatment opportunities.
Therefore, in known inflammatory bowel disease, the prevention, the early
detection and the adequate therapeutic response to certain complications are
important goals in the follow-up of inflammatory bowel disease patients. Disease
complications are separated into intestinal and extraintestinal complications.
Intestinal complications are somewhat disease specific, which means that they
occur exclusively in either Crohn's disease or ulcerative colitis (e.g., enteric
fistulas are particularly found in Crohn's disease and toxic megacolon in
ulcerative colitis). Most extraintestinal complications occur in both forms of
inflammatory bowel disease (e.g., anemia, thromboembolic events or osteoporosis).
The current knowledge on pathogenesis, diagnostic tools, prevention and treatment
of certain intestinal and extraintestinal complications is reviewed.
PMID- 10690586
TI - Chronic inflammatory bowel disease and cancer.
AB - Colorectal cancer represents the major cause for excess morbidity and mortality
by malignant disease in ulcerative colitis as well as in Crohn's disease. The
risk for ulcerative colitis associated colorectal cancer is increased at least 2
fold compared to the normal population and colorectal cancer is observed in 5.5
13.5% of all patients with ulcerative colitis and 0.4-0.8% of patients with
Crohn's disease. Established risk factors include long duration of the disease,
large extent of the disease, low activity of the disease, young age at onset,
presence of complicating primary sclerosing cholangitis or stenotic disease and
possibly lack of adequate surveillance, inadequate pharmacological therapy,
folate deficiency and non-smoking. Crohn's disease is associated with an
increased risk of colorectal carcinoma in patients with long-standing disease,
strictures and fistulae under the condition that the colon is involved, tumors of
the small intestine may occur occasionally. Extracolonic malignancies are rare,
with the exception of biliary tract cancer. Ulcerative colitis associated
colorectal cancer typically can occur in the entire colon, is often multifocal
and of undifferentiated histology. Stage distribution and prognosis of ulcerative
colitis associated colorectal cancer appears to be similar to that of sporadic
colorectal cancer with an overall survival of about 40% (15-65%) after 5 years
with tumor stage at diagnosis being the most important predictive parameter for
survival. Tumor markers helpful for the diagnosis of sporadic colorectal cancer
fail to differentiate between inflammatory response and malignant transformation.
In contrast the histologic evidence of dysplasia was shown to be a strong
indicator of underlying carcinoma or developing malignant transformation. The
presence of a surface projection termed dysplasia associated lesion or mass is
highly indicative of underlying or associated cancer. While the routinely
performed search for dysplasia is hampered by high interobserver variation the
demonstration of DNA-aneuploidy or genetic changes which may confirm the ongoing
malignant transformation has not yet become clinical routine. The genetic
alterations found in ulcerative colitis associated colorectal cancer involve many
of the same targets found in sporadic colorectal tumors and include multiple
sites of allelic deletion, microsatellite instabilities, and mutations of APC,
p53, Ki-ras as well as MSH2 and other genes. The progression of dysplasia to
carcinoma is generally accompanied by an accumulation of these mutations and the
similarities in the biology of colorectal cancer associated with ulcerative
colitis and sporadic colorectal cancer appear to outweigh their difference. In
regard to the management of dysplasia and cancer, the role of surveillance
programs for the early detection of ulcerative colitis associated colorectal
cancer at a curable stage is still under debate. Although these programs failed
at tumor prevention and lethal carcinomas are still found inadvertently in
patients under surveillance, the majority of surveillance programs could reduce
mortality by detecting more cancers at a still curable stage. Current
recommendations for surveillance include, therefore, biennial colonoscopy with
extensive biopsies after 8-10 years of total colitis or after 15-20 years of left
sided colitis. In the presence of cancer or unequivocal high-grade dysplasia
and/or dysplasia associated lesion or mass proctocolectomy is considered
adequate. The evidence of low-grade dysplasia should be confirmed before
proctocolectomy is considered.
PMID- 10690587
TI - Immunopharmacology of 5-aminosalicylic acid and of glucocorticoids in the therapy
of inflammatory bowel disease.
AB - Glucocorticoids as well as 5-aminosalicylic acid have been used successfully in
different formulations during the past 40 years for the treatment of both acute
and chronic inflammation in inflammatory bowel disease. The mechanism by which
the drugs exert their actions are only partially known. Recent studies of the
immunoregulation in the lamina propria provide evidence that numerous therapeutic
mechanisms contribute to the efficacy of these drugs including the inhibition of
arachidonic acid metabolism, a decrease in radical formation by oxygen radical
scavenging, an inhibition of both in vivo and in vitro activation of peripheral
and intestinal lymphocytes. Moreover direct immunoregulatory effects exerted by
the drug may be important in influencing the complex balance of pro-inflammatory
mechanisms during active intestinal inflammation. Such effects are the inhibition
of both peripheral and intestinal B lymphocyte immunoglobulin secretion as well
as the inhibition of pro-inflammatory cytokine production and their binding to
receptors. Some of these immunoregulatory effects appear to be mediated by an
inhibition of the activation of the nuclear factor kappa B transcription factor
family by steroids and (less potent) aminosalicylic acid. Activation of nuclear
factor kappa B appears to be pivotal for the sustained upregulation of
inflammation molecule expression in many inflammatory diseases. It seems,
therefore, most likely that the enormous therapeutic potency of steroids, as well
as the anti-inflammatory properties of 5-aminosalicylic acid, are not achieved by
a single action of the drug. The complex orchestration of numerous inhibitory
interactions with pro-inflammatory principles will add to the therapeutic
potential of steroids and of 5-aminosalicylic acid in the treatment of both acute
and chronic intestinal inflammation.
PMID- 10690588
TI - Treatment of ulcerative colitis.
AB - In recent years new standards for the treatment of ulcerative colitis have
evolved. This review updates evidence based therapy for the various clinical
situations as well as some novel approaches. The literature search was based on
Medline, Cochrane database (CD-ROM) and handsearch of relevant papers including
quoted literature. There is clear-cut evidence-based support for the use of local
5-aminosalicylates in mild/moderate distal and oral 5-aminosalicylates in
extensive ulcerative colitis. The administration of corticosteroids is definitely
indicated in severe disease. Fulminant attacks are treated by intravenous
cyclosporine or colectomy. In chronic active disease azathioprine is probably
helpful. Relapse prevention again is a domain of 5-aminosalicylates or, as a
novel development, E. coli Nissle. The various meta-analyses as well as the
controlled trials performed in the various clinical situations typical for the
manifestations of ulcerative colitis form a solid base of evidence to guide
individual treatment decisions.
PMID- 10690589
TI - Treatment of Crohn's disease.
AB - The treatment of Crohn's disease depends on disease location and disease
activity. It can be divided into medical and surgical treatment. While surgery is
reserved for complications such as abscesses or failure of pharmacological
treatment (fistulae, perianal disease, or strictures) medical treatment aims at
induction and maintenance of remission. In order to achieve these goals
supportive and therapeutic strategies must be used. Supportive measures include
substitution of vitamins, particularly fat-soluble vitamins, and minerals in
deficiencies due to resection or disease involvement of the small bowel. All
patients on long-term steroids should receive calcium and vitamin D in order to
prevent osteoporosis. Therapeutic options include drug treatment
(corticosteroids, antibiotics, salicylates, and immunosuppressives), nutrition
(parenteral or enteral), and endoscopy (dilatation of strictures). Depending on
disease location different pharmacologic preparations of salicylates or
corticosteroids should be used, e.g., enemas for distal colitis. The most potent
drugs for long-term control are immunosuppressive agents, particularly
azathioprine. It is the most widely investigated immunosuppressive agent in
Crohn's disease and should be the first line treatment for patients with steroid
refractory, chronic steroid dependent, fistulating, and stenosing courses. In the
future, more potent drugs and better risk stratification criteria should improve
the treatment of Crohn's disease.
PMID- 10690590
TI - Future developments in diagnosis and treatment of inflammatory bowel disease.
AB - The inflammatory bowel diseases ulcerative colitis and Crohn's disease are
probably syndromes rather than single entities. Neither the susceptibility genes
nor definite environmental factors have been found thus far. The "immune concept"
of these disorders might not include all patients. Consequently immune based new
approaches on alternative etiological/pathophysiological pathways may be
necessary. New developments in diagnostic techniques will probably improve
patient acceptance and may even help to prevent carcinoma development.
PMID- 10690591
TI - Trypsin level in gallbladder bile and ductitis and width of the cystic duct.
AB - BACKGROUND/AIMS: The change from laparotomy to laparoscopy for cholecystectomy
has raised the question of how to manage concomitant bile duct stones. The
present-day interest--and controversy--has focused on a transcystic approach
reported to be feasible in 66-96% of cases, but without explaining the necessary
prerequisite: the widening of the cystic duct. The cystic duct, wide mainly in
patients with bile duct stones, has been reported to be highly variable: from
strictured to very wide. The present study aims at comparing the trypsin level in
the gallbladder bile and the cystic duct morphology and width in patients with
and without bile duct stones. METHODOLOGY: A prospective series of 63 gallstone
patients, 30 with and 33 without bile duct stones (controls), underwent
cholecystectomy and bile duct clearance. The study includes the trypsin level in
the gallbladder bile, the width and morphology of the cystic duct, and the size
of the gallstones. RESULTS: The patients with bile duct stones had, in contrast
to the controls, higher trypsin levels in the gallbladder bile (P < 0.001) and
wider cystic ducts (P < 0.001) with more pronounced signs of chronic ductitis.
CONCLUSIONS: The obtained results strongly suggest that the increased trypsin
level, a sign of reflux of pancreatic juice, caused changes in the cystic duct
that facilitate gallstone migration, which also ought to render a transcystic
stone extraction feasible.
PMID- 10690592
TI - Synchronous carcinoma of the gallbladder in a patient with intrahepatic bile duct
carcinoma.
AB - An 83-year-old woman, diagnosed as having cholelithiasis, was admitted to the
Department of Surgery, Nippon Medical School, with right hypochondrial pain.
Ultrasonography and computed tomography revealed a mass in the gallbladder fundus
and a hypovascular tumor in the anterior segment of the liver. Magnetic resonance
imaging showed stenosis of the intrahepatic bile duct and dilatation of its
proximal portion. She was diagnosed as having intrahepatic bile duct carcinoma
combined with gallbladder carcinoma. At laparotomy, there was evidence of
multiple peritoneal metastases and intraoperative histological examination of the
gallbladder tumor revealed adenocarcinoma. Accordingly, only cholecystectomy and
needle biopsy of the liver tumor was performed. Histological examination of the
gallbladder revealed papillary adenocarcinoma invading the muscularis propria
with medullary growth or intermediate stroma. There was no microvessel invasion,
no perineural invasion and no lymph node involvement. On the other hand, the
liver tumor was a cholangiocarcinoma with a well-differentiated tubular pattern.
Therefore, this was a rare case of synchronous carcinoma of the gallbladder
associated with intrahepatic bile duct carcinoma.
PMID- 10690593
TI - Coexistence of primary biliary cirrhosis and myasthenia gravis: a case study.
AB - We present a case that suggests a relationship between primary biliary cirrhosis
and myasthenia gravis. A 43-year-old Japanese woman was admitted to the Nagoya
City University Medical School, First Department of Internal Medicine with
abnormal liver function in August 1991. She had had ptosis of the right eye since
1990. She had not been treated for liver disease. Ptosis of the right eye and
hepatomegaly were present. Serum laboratory examinations revealed elevated
biliary enzymes and IgM levels; tests were positive for antimitochondrial
antibody and antiacetylcholine antibody. Liver histology revealed chronic non
suppurative destructive cholangitis and led to a diagnosis of primary biliary
cirrhosis. The tensilon test was positive. Electromyography with repetitive motor
nerve stimulation revealed a neuromuscular junction defect; i.e., the primary
characteristic of myasthenia gravis. The patient was diagnosed with myasthenia
gravis. Although the development of myasthenia gravis has previously been
reported in patients with primary biliary cirrhosis during D-penicillamine
administration, this is a very rare case of the coexistence of both diseases
before such treatment.
PMID- 10690594
TI - A case of segmental primary sclerosing cholangitis.
AB - A 74-year-old man was admitted to the Yokohama City University School of Medicine
for investigation of high values of ALP and Y-GTP. Radiographic examinations,
including abdominal computed tomography and percutaneous transhepatic
cholangiography, strongly suggested bile duct cancer in the hepatic hilus. After
left lobectomy, pathological examination disclosed segmental primary sclerosing
cholangitis. Clinical examination cannot always distinguish primary sclerosing
cholangitis from cancer. We report a case of segmental primary sclerosing
cholangitis and discuss the diagnosis and the treatment of this disease.
PMID- 10690595
TI - Adenomyoma of the common bile duct: report of a case.
AB - We report a case of adenomyoma in the common bile duct accompanied by obstructive
jaundice. A 64-year-old woman presented with abdominal pain, fever, appetite loss
and jaundice. Endoscopic retrograde cholangiopancreatography revealed possible
stenosis in the distal common bile duct. We could not distinguish whether the
tumor was benign or malignant based on the clinical presentation, or biochemical,
radiographic, or endoscopic investigations. Pancreatoduodenectomy was performed.
The histological diagnosis was adenomyoma. The natural history of and optimal
treatment for, adenomyoma have not been established.
PMID- 10690596
TI - Primary carcinoid tumor of the gallbladder: resection of a case metastasizing to
the liver and analysis of outcomes.
AB - Gallbladder carcinoid tumor is a rare and aggressive neoplasm, usually lacking
specific symptoms, as they typically are unassociated with the carcinoid
syndrome, despite frequent hepatic spread. The patient was an 81-year-old man
with right upper quadrant pain who underwent radical surgery for carcinoid tumor
of the gallbladder with liver metastasis (preoperative diagnosis, carcinoma). We
analyzed the outcome of previously reported cases of gallbladder carcinoid.
Increasing tumor size and depth of invasion progressively compromised the 2-year
survival. These findings underscore the importance of early detection.
PMID- 10690597
TI - A new examination for both biliary and gastrointestinal function after
pancreatobiliary surgery--single-isotope two-day method.
AB - BACKGROUND/AIMS: There are no established tests for both biliary and
gastrointestinal function after pancreatobiliary surgery. In this study, mixing
of ingested food with bile after long-term postoperative period was evaluated.
METHODOLOGY: Sixteen patients having undergone Imanaga pancreatoduodenectomy
(postoperative years = 6.2 +/- 2.0) were evaluated concerning physiologic
function of biliary tract and residual stomach using gastric emptying and
hepatobiliary scintigraphy. RESULTS: At least 24 months after Imanaga
pancreatoduodenectomy, postoperative patients had reached 95.8 +/- 4.9% of the
pre-illness bodyweight. Gastric emptying half-time (GET1/2) ranged from 9-147 min
(mean: 60.6 +/- 35.0). The time of bile excretion from liver to jejunum ranged
from 5-45 min (mean: 11.3 +/- 7.8). Asynchrony time ranged from -5-40 min (mean:
11.3 +/- 7.8). There was no significant correlation between GET1/2 and recovery
of bodyweight (r = -0.042, P = 0.8809). Similarly, there was no significant
correlation between the time of bile excretion and recovery of bodyweight (r =
0.042, P = 0.8791). On the other hand, asynchrony time had a significant inverse
correlation with recovery of bodyweight (r = -0.590, P = 0.0146). CONCLUSIONS:
Single-isotope two-day method is an original and useful technique to evaluate
biliary and gastrointestinal physiologic function after long-term postoperative
period.
PMID- 10690598
TI - Surgical anatomy of the medial segment (S4) of the liver with special reference
to bile ducts and vessels.
AB - BACKGROUND/AIMS: Resection of the inferior area of the medial segment (S4a) plus
S5 with preservation of the superior area of the medial segment (S4b) is being
performed to manage hilar bile duct carcinoma and pT2 type gallbladder carcinoma,
and thus, attention has been focused on the surgical anatomy of the medial
segment of the liver to identify the specific vessels and bile ducts of the areas
of that segment to be resected and to be preserved. METHODOLOGY: Anatomical study
of the bile duct, portal vein, middle hepatic vein, and middle hepatic artery to
the medial segment branches of the liver (S4) was performed in a total of 171
specimens comprised of 71 adult cadavers, and 100 liver casts. RESULTS: 1) Two
main types of bile duct branches of the medial segment (B4) were recognized. Type
I included the branches which joined to the left hepatic duct on the hilar duct
side (35.5%), and type II included the branches that joined on the peripheral
side (54.6%). Several subtypes were also found in both types. The B2-B3
confluence was mostly on the left (41.7%) or posterior (42.7%) to the umbilical
portion (UP) of the portal vein, and to the right of the UP (hilar side) in only
15.6%. 2) The portal vein of the medial segment branches (P4): P4a branched from
the right angle and upper right border of the UP in every specimen. The most
common morphology was 1 large and 2-3 small branches (41%). P4b was almost always
found to branch posterior to the UP and lower than P4a, and the most common
morphology was 1 large and 0-1 small branches (57.8%). 3) The middle hepatic
vein: In 83.2% a common trunk was observed at the confluence with the inferior
vena cava, and 8 types of the middle hepatic vein were recognized. 4) The middle
hepatic artery: It arose from the left hepatic artery in 61.5%, from of the right
hepatic artery in 27.5%, from the proper hepatic artery in 5.5%, and from both
the left and the right hepatic artery in 5.5%. CONCLUSIONS: The detailed vascular
and bile duct anatomy of S4 is described. This study should be helpful in
identifying the specific vessels and bile ducts of the areas of the medial
segment to be resected and to be preserved, thereby facilitating resection of the
medial segment.
PMID- 10690599
TI - Gastric pseudotumor.
AB - The authors present a case report of a pseudotumor of the stomach and a brief
discussion about this very unusual entity. A 75-year-old female patient was
admitted with melena and a large epigastric tumor; she underwent upper
gastrointestinal endoscopy, abdominal ultrasound, magnetic resonance imaging,
guided needle aspiration and angiography. Preoperative diagnostic hypothesis
included a partially thrombosed aneurysm of the splenic artery, pancreatic cystic
neoplasm with gastric invasion and pancreatic pseudocyst complicated with
hemorrhage. Laparotomy revealed a gastric tumor and the patient was submitted to
a radical subtotal Billroth II gastrectomy. Only the pathologic examination
revealed the unexpected definitive diagnosis of an organized intramural gastric
hematoma. There were no postoperative complications and she remains asymptomatic
10 months after surgery.
PMID- 10690600
TI - Factors influencing bowel function after low anterior resection and sigmoid
colectomy.
AB - BACKGROUND/AIMS: The aim of this study was to evaluate the subjective bowel
function after low anterior resection and sigmoid colectomy and to clarify the
clinicopathologic factors influencing postoperative bowel habits. METHODOLOGY:
Eighty-six patients who underwent low anterior resection and sigmoid colectomy
replied to the questionnaire which consisted of 8 categories of bowel symptoms.
The patients were divided into 2 groups: good bowel function showing less than
half of symptoms (< 4) and poor bowel function showing more than half of symptoms
(> or = 4). RESULTS: After low anterior resection, patients were often
complicated with incomplete evacuation (75%), bowel movement at night (60%),
defecation more than twice a day (46%), and soiling (27%). The mean number of
defecation/day and frequency of patients with night stools was significantly
higher after low anterior resection than sigmoid colectomy (2.81 vs. 2.18, P <
0.05; and 60% vs. 29%, P < 0.05). Poor bowel function after low anterior
resection was frequent in patients with high ligation of the inferior mesenteric
artery (82%, P < 0.05), injury to the pelvic autonomic nerve (82%, P < 0.05), and
blood transfusion; while poor bowel function after sigmoid colectomy was frequent
in patients with resected colon measuring 25 cm or more (81%, P < 0.05).
CONCLUSIONS: These results indicate that poor bowel function after low anterior
resection is associated with high ligation of the inferior mesenteric artery and
injury to the pelvic autonomic nerve; while poor bowel function after sigmoid
colectomy correlates with length of the resected colon. Less aggressive surgery
is needed to preserve good bowel function.
PMID- 10690602
TI - Elevated carcinoembryonic antigen (CEA) levels in a patient with no malignancy.
AB - Carcinoembryonic antigen rarely exceeds serum levels of 10-12 ng/mL in benign
diseases and has never been found above 24 ng/ml. We report a case in which
carcinoembryonic antigen serum levels reached the value of 44.9 ng/ml without any
overt reason (after 22 months of follow-up). A decline of the carcinoembryonic
antigen to normal ranges was noticed after a radiolabeled anti-carcinoembryonic
antigen monoclonal antibody scan was performed. The reason for this phenomenon is
unclear.
PMID- 10690601
TI - BCL2 and BAX expression in hyperplastic and dysplastic rectal polyps.
AB - BACKGROUND/AIMS: Members of the gene family that includes BCL2 and BAX are
functionally antagonists in the apoptosis process and they have been observed in
normal and neoplastic tissues. The aim of this study is to investigate the
combined effects of BCL2 and BAX protein in normal mucosa, dysplastic and
hyperplastic polyps of the rectum. METHODOLOGY: We studied BCL2 and BAX protein
expression in 40 cases of adenomatous polyps all located in the rectum, with
different dysplastic gradings, and the mean time in 10 cases of normal rectal
mucosa. RESULTS: BCL2 expression was found more frequently in hyperplastic and in
low dysplastic polyps with moderate and strong positivity compared to moderate
and severe dysplasia. BAX expression was found in normal mucosa in hyperplastic
and dysplastic polyps, the immunoreactivity was prevalently moderate and strong.
CONCLUSIONS: These preliminary data suggest that BCL2 and BAX confirm a probably
different role in apoptosis. Nevertheless, it is important to know the relation
between the molecular pathways of apoptosis, the defective mismatch repair and
the tumor suppressor genes associated with an increased mutation rate in
cancerogenesis of the colorectum.
PMID- 10690603
TI - Occult colon cancer in a patient with an unexplained episode of pulmonary
embolism.
AB - The association between venous thromboembolism and cancer has been widely
documented and the main factor responsible for cancer-induced venous
thromboembolism is considered mostly linked to a hypercoagulation state induced
by the cancer itself. There is no consensus on investigative strategies for
occult cancer in a patient with a thrombophilic condition. We report a patient
who manifested an isolated episode of pulmonary embolism without specific evident
sources of venous thromboembolism. The routine clinical and laboratory work-up to
detect an occult cancer did not reveal any malignancy. A history of duodenal
ulcer in association with a recent slight alteration in bowel habits led us to
perform an esophagogastroduodenoscopy which was negative for malignancy, and a
barium enema followed by colonoscopy, which revealed the presence of a tumor
limited to the large intestine. An unexplained clinically evident
hypercoagulation state, even in the presence of mild clinical symptoms, needs
more thorough diagnostic strategies when simple methods of screening for occult
cancer are negative.
PMID- 10690604
TI - A prospective randomized trial from Turkey comparing octreotide versus injection
sclerotherapy in acute variceal bleeding.
AB - BACKGROUNDS/AIMS: Bleeding from gastroesophageal varices continues to be a life
threatening complication of chronic liver diseases and portal hypertension. The
purpose of this randomized prospective study is to compare the efficacy of
octreotide administration and emergency injection sclerotherapy for the control
of actively bleeding esophageal varices and prevention of early rebleeding in
patients with cirrhosis. METHODOLOGY: A total of 66 episodes of endoscopically
proven active variceal bleeding in 52 patients were included in this study.
Following admission to the hospital, the patients were resuscitated with blood
and plasma, and fiberoptic endoscopy was performed within 2 hours. Thirty-six
bleeds in 28 patients and 30 bleeds in 24 patients were randomized to endoscopic
variceal sclerotherapy (1% polidocanol) and to octreotide infusion (at 50
micrograms/h for 12 hours following the initial 50 micrograms i.v. bolus),
respectively. RESULTS: Bleeding was initially controlled within 6 hours in 75% of
episodes by endoscopic variceal sclerotherapy and in 73.3 by octreotide infusion
(P > 0.05). There were no significant differences between the 2 groups in early
rebleeding (within 72 hours of randomization) (22% vs. 22.7%), blood transfusion
(4.2 +/- 1.8 units vs. 4.8 +/- 2.9 units), or hospital mortality (3.6% vs. 3.3%).
Treatment failed in 9 episodes (25%) in the sclerotherapy group and in 8 episodes
(26.7%) in the octreotide group. CONCLUSIONS: We consider that Octreotide would
appear to be as effective as sclerotherapy in both the early control of variceal
hemorrhage and in the prevention of early recurrent bleeding and should therefore
be considered the treatment of choice in those centers where 24-hour endoscopy is
not available. Furthermore, even in hospitals that do have a 24-hour endoscopy
service there is good evidence that octreotide therapy should be commenced as
soon as a patient enters hospital with a suspected variceal bleed to achieve
rapid homeostasis. When initial hemostasis is achieved, elective endoscopic
therapies can be undertaken with greater success.
PMID- 10690605
TI - Comparison between digestive endoscopy and 24-hour esophageal pH monitoring for
the diagnosis of gastroesophageal reflux esophagitis: "presentation of 100
cases".
AB - BACKGROUND/AIMS: We present the results obtained from 100 new cases of clinical
esophagitis caused by gastroesophageal reflux at the Hospital of Caldas and at
the Service of Gastroenterology of VIME (Endoscopical Video Medicine) in
Manizales, Caldas, Colombia; between the months of June and November of 1996,
evaluated by digestive endoscopy and classified based on the New Savary-Miller 5
Grade Classification. METHODOLOGY: The patients were selected based on the
presence of symptomatology suggestive of esophagitis caused by gastroesophageal
reflux; an endoscopy was performed followed by 24-hour esophageal pH monitoring.
The patients were grouped according to their grade of esophagitis in the New
Savary-Miller Classification. The central analysis was focused on determining the
existing relationship between the observed esophagitis and the results obtained
by the 24-hour esophageal pH monitoring. RESULTS: Findings show that 51% and 48%
of patients with esophagitis grades 1 and 2 had a normal DeMeester's score (<
14.7) in channel 1. In channel 2 we found normal scores in 86% and 82% of
esophagitis grades 1 and 2, respectively. CONCLUSIONS: We ask whether the average
level of pathological reflux of 14.7 can be extrapolated to our population; also
whether endoscopical overdiagnosis of esophagitis caused by gastroesophageal
reflux exists, or if non-recognized causes of esophagitis exist. Another question
is if it is justified to order 24-hour esophageal pH monitoring in patients with
grades 1 and 2 esophagitis.
PMID- 10690606
TI - Diverticular disease of the small bowel.
AB - BACKGROUND/AIMS: The clinical picture of small bowel diverticula has not been
well-clarified because of its infrequent incidence and limited case number in
most published reports. We evaluated a large series of small bowel diverticula
and further compared the clinical picture of the diverticula at different parts
of small bowel. METHODOLOGY: The medical records of 88 patients with diverticular
disease of the small bowel were reviewed from 1979-1997. This study included all
diverticula from duodenum to ileum. RESULTS: The most common small bowel
diverticulum was duodenal diverticulum (45%), followed by Meckel's diverticulum
(23%). The most common clinical presentation was abdominal pain (48.9%), followed
by gastrointestinal bleeding (29.5%). However, among the Meckel's diverticula,
gastrointestinal bleeding (60%) was the most common presentation. The accurate
diagnostic rate for diverticula, overall, was 25.0%. Thirty-nine (44.3%) of the
diverticula were found incidentally. Twenty-three cases (26.1%) were diagnosed by
gastrointestinal barium study. Thirty-eight (42.1%) diverticula were left alone
without any sequela, and the remaining 55 (56.8%) diverticula needed either bowel
resection (30.7%) or diverticulectomy (26.1%). All of the Meckel's diverticula
were treated by surgery. Postoperative complication occurred in 9 (10.3%)
patients. Hospital mortality rate was 3.4%. CONCLUSIONS: Duodenal diverticulum
was the most common small bowel diverticulum. Abdominal pain and gastrointestinal
bleeding were the most common clinical presentations. The small bowel
diverticula, except for Meckel's diverticulum, did not need to be treated if
there were no significant symptoms.
PMID- 10690607
TI - Changing pattern of intestinal obstruction in Accra, Ghana.
AB - BACKGROUND/AIMS: Over the past 50 years acute intestinal obstruction has remained
among the commonest causes of the acute abdomen, along with peritonitis,
appendicitis and gastrointestinal perforations. However several observers have
noticed over the past 2 decades a shift in the etiological spectrum. The study
aims at ascertaining the precise nature of the change. METHODOLOGY: Published
data on intestinal obstruction from the Korle Bu Teaching Hospital over the past
50 years were reviewed, as the consistent report format permitted ready
comparison of the series. Emphasis was placed on clinical features, established
cause and resulting complications. RESULTS: The case load of intestinal
obstruction has dwindled over the past 3 decades, accounting for 0.7% of all
hospital admissions compared with 1.4% 30 years earlier. External hernias
together with adhesive bands still constitute the bulk of presenting cases, but
the proportions have changed with strangulated hernias accounting for 59.8%
instead of 77.6%. The change has paralleled a rise in elective hernia day case
surgery. The incidence of intussusception has almost doubled (7.4% from 4.0%) and
it still afflicts the very young. Colonic neoplasms have been commoner over the
past 2 decades although the incidence (3.3%) falls short of Western figures.
Overall mortality has remained unchanged at 9.4% and this has been associated
with a rise in resection rates to 18.3%. CONCLUSIONS: The patterns of intestinal
obstruction have been much influenced by changing attitudes regarding elective
hernia surgery and evolving financial policies.
PMID- 10690608
TI - Reduced levels of coagulation factor XIII in patients with advanced tumor
disease.
AB - BACKGROUND/AIMS: Coagulation factor XIII, which induces the stabilization of
fibrin the final step in the coagulation cascade, has various physiological
effects. Among these, its beneficial effect in gastrointestinal bleeding episodes
is well known. With the exception of inflammatory bowel disease, however, few
data are available about this effect, particularly with regard to its role in
diffuse bleeding in tumor patients. The study was designed to carry out
prospective follow-up investigations, gathering data concerning factor XIII
levels in patients with advanced gastrointestinal tumors and evaluating the
course of the disease as well as the incidence of bleeding. METHODOLOGY: Sixty
patients (22 women, 38 men; median age: 60; range: 29-79) with advanced
gastrointestinal tumors were followed-up prospectively. Factor XIII levels were
measured using chromogenic substrate. The correlation between the FXIII level and
the patients' survival was analyzed using the Cox model. RESULTS: Factor XIII
deficiency (below 70%) was seen in only 7 patients (11.6%), 6 of whom died within
a median of 1.5 months after the measurement. In all patients however, there was
a significant correlation (P = 0.0133) between FXIII levels and the risk of
death. Four bleeding episodes occurred in 3 patients, three times with FXIII
levels being below the lower normal range. When substitution was attempted, it
was only successful in 1 patient in whom the FXIII level was reduced.
CONCLUSIONS: FXIII may have predictive value as a marker for the prognosis in
these patients with advanced tumor disease. Bleeding episodes were rarely seen,
but when they do occur they may be associated with reduced levels of FXIII, and
substitution may be beneficial as an adjunct or even as the sole therapeutic
intervention.
PMID- 10690609
TI - Management of patients with HCV infection poorly tolerant to recombinant
interferon alpha.
AB - BACKGROUND/AIMS: To evaluate leukocyte interferon-alpha tolerability and efficacy
in the retreatment of patients poorly tolerant to recombinant interferon-alpha.
METHODOLOGY: Patients with chronic hepatitis C, poorly tolerant to a previous
interferon-alpha treatment (118 patients; 73 "relapsers": Group I; 45 "non
responders": Group II) were retreated with 6 MU tiw of leukocyte interferon-alpha
for 6 months and then followed-up for 12-34 months. Only patients with complete
regression of any previous interferon-related adverse event were included.
RESULTS: Three patients dropped out due to recurrence of a severe depressive
syndrome. In 86/115 patients (75%) no significant lifestyle changes versus
baseline were observed during retreatment, while 29 subjects experienced a
moderately negative interference on their living habits. The different influence
on the patients' quality of life of leukocyte interferon in comparison with the
previous treatment was significant (P < 0.001). In 98 patients the interferon
related adverse events significantly decreased. After 12 months of follow-up, a
sustained biochemical response was observed in 40 patients (Group I:31; Group
II:9), and a persistent virological response in 28 (Group I:23; Group II:5).
CONCLUSIONS: The good compliance with leukocyte interferon administration shown
by poorly tolerant patients, non-responders/relapsers to recombinant interferon,
permitted a retreatment with full doses, so increasing the chance to obtain a
larger number of sustained responses.
PMID- 10690610
TI - Surgical outcome in cirrhotic patients with hepatitis C-related hepatocellular
carcinoma.
AB - BACKGROUND/AIMS: The aim of this study was to clarify the surgical outcome in
cirrhotic patients with hepatitis C-related hepatocellular carcinoma (HCC).
METHODOLOGY: The surgical outcome of 26 HCVAb-positive cirrhotic patients with
hepatitis C antibody (the C-related HCC group) and 18 HCVAb-negative cirrhotic
patients with (the non-C-related HCC group) undergoing hepatectomy for HCC were
compared. The C-related HCC group was HCVAb[+], HBsAg[-] for hepatitis B surface
antigen in 25 patients and HCVAb[+], HBsAg[+] in 1, and the non C-related HCC
group was HCVAb[-], HBsAg[+] in 15 and HCVAb[-], HBsAg[-] in 3. RESULTS:
Preoperative aspartate and alanine aminotransferase in the C-related HCC group
were significantly (P < 0.01) higher than in the non-C-related HCC group. There
were no significant differences in the operative method, intraoperative blood
loss and weight of resected liver or pathological data between the 2 groups. In
the recurrence pattern, the incidence of multicentric occurrence in the C-related
HCC group (53.3%) was significantly (P < 0.05) higher than in the non-C-related
HCC group (7.7%). The mortality rate in both groups was 0% and no operative death
was encountered. The crude survival and disease-free survival rates at 3 years
were similar: 80.8% and 57.7% in the C-related HCC group and 77.8% and 55.6% in
the non-C-related HCC group, respectively. CONCLUSIONS: Although surgically
treated cirrhotic patients with C-related HCC showed worse preoperative hepatitis
status and a higher incidence of recurrence due to multicentricity compared with
non-C-related HCC, the mortality and prognosis of patients with C-related HCC did
not differ from that of non-C-related HCC. The indication of hepatic resection
and consideration for the high incidence of postoperative multicentric occurrence
in the patients with C-related HCC should therefore be more careful than in
patients with non-C-related HCC.
PMID- 10690611
TI - Management and outcome of liver recipients with post-transplant
lymphoproliferative disease.
AB - BACKGROUND/AIMS: The possibility of development of post-transplant
lymphoproliferative disease by patients receiving immunosuppressive therapy is
well known. However, elective treatment and outcome remain controversial. We
reviewed the management and outcome of our patients with post-transplant
lymphoproliferative disease. METHODOLOGY: Records of 457 patients who underwent
orthotopic liver transplantation from 1986 to 1997 were analyzed. Patients who
developed post-transplant lymphoproliferative disease were reviewed
retrospectively. Incidence, clinical presentation, risk factors and outcomes were
examined with special emphasis on ductopenic rejection and hilum involvement.
RESULTS: Eleven patients developed a post-transplant lymphoproliferative disease
(2.4%). These were B-cell non-Hodgkins lymphoma, Epstein-Barr virus-associated in
all cases. Five patients (45.5%) received monoclonal antibodies or antithymocyte
globulin. Seven patients (63.6%) developed a lymphoproliferative disease before 9
months post-transplant and 4 recipients (36.4%) after 20 months. No late
lymphomas regressed after withdrawal from immunosuppression. Six patients (54.5%)
were treated with chemotherapy. Eight patients (72.7%) had a tumoral remission.
Five patients (45.5%) developed chronic rejection after immunosuppressant
discontinuation. Four of them died as a consequence of ductopenic rejection and
retransplantation was required in another; 2 died due to graft hilum
infiltration. Five patients (45.5%) are alive after a follow-up of 36.5 +/- 32
months (range: 4-77 months). CONCLUSIONS: Patients with post-transplant
lymphoproliferative disease require a close follow-up in order to promptly treat
conditions that could lead to death. In our series, these were more closely
associated with a failing transplanted organ than with the lymphoma itself.
PMID- 10690612
TI - Role of iron load on fibrogenesis in chronic hepatitis C.
AB - BACKGROUND/AIMS: In chronic viral hepatitis, an enhanced iron load is related to
lower response to interferon. Furthermore, iron, through the production of oxygen
radicals, may stimulate hepatocyte necrosis and the activation of cells
responsible for synthesis and deposition of extracellular matrix. We investigated
the relationship between iron load, evaluated by serum assays, and liver
fibrogenesis in chronic active viral hepatitis. METHODOLOGY: Serum iron,
ferritin, transferrin saturation and serum markers of hepatic fibrogenesis
(Laminin and the amino-terminal peptide of procollagen III-NPIIIP-) were assayed
in 102 patients (47 females, 55 males, mean age 42.48 years) affected by chronic
hepatitis C virus and in 81 healthy controls (47 males, 34 females). In hepatitis
C virus patients (studied before alpha-interferon treatment) a semiquantitative
score for portal inflammation, necrosis and fibrosis was applied to liver biopsy.
RESULTS: Serum indices of iron load were higher in hepatitis C virus patients
than in controls, and were higher in cirrhotic than in chronic hepatitis cases.
Ferritin and serum iron were positively correlated with NPIIIP and laminin;
moreover cases with ferritin levels over the normal limit for sex and age had
higher levels of NPIIIP and laminin than cases with normal or poor iron status.
CONCLUSIONS: Our data suggest that even a mild increase of iron load stimulates
hepatic fibrogenesis, probably adding oxygen free radical injury to the damage of
viral infection.
PMID- 10690613
TI - Experimental and clinical studies on liver regeneration following transcatheter
portal embolization.
AB - BACKGROUND/AIMS: We studied compensatory hypertrophy following transcatheter
portal embolization experimentally in dogs and clinically under the condition of
cholestasis. METHODOLOGY: Experimental study: Sixteen dogs were used for this
study. Transcatheter portal embolization was performed in the left lobes (70% of
the total liver) using Gelfoam powder in dogs with 2-week obstructive jaundice.
Liver weight, liver blood flow and the intracellular adenosine triphosphate
content of isolated hepatocytes were measured after transcatheter portal
embolization. Clinical Study: transcatheter portal embolization of the right
portal branch was performed in 13 patients with cancer of the biliary tract and 3
patients with hepatocellular carcinoma before (extended) right lobectomy, using
Gelfoam powder and thrombin. Six patients who had a total bilirubin level > 5
mg/dLunderwent a percutaneous transhepatic biliary drainage before transcatheter
portal embolization. Liver function tests, a volumetric study with computed
tomography and immunohistochemical staining for profilerating cell nuclear
antigen and apoptosis in the resected livers were performed. RESULTS:
Experimental study: The weight ratio of the non-embolized lobes to the total
liver, 2 weeks after transcatheter portal embolization in the dogs with jaundice,
was significantly lower than that of the normal dogs with transcatheter portal
embolization (40.5 +/- 4.5% vs. 47.6 +/- 3.2%), but significantly larger than
that of the dogs without transcatheter portal embolization. The cellular
adenosine triphosphate content and tissue blood flow in the embolized lobes were
significantly lower than those in the nonembolized lobes in the normal and
cholestatic livers. Clinical study: The postoperative course in all patients was
uneventful, with no serious complication or liver dysfunction. Extended right
lobectomy with caudate lobectomy was equivalent to 65% before transcatheter
portal embolization and to 56% after, transcatheter portal embolization owing to
compensatory hypertrophy of the left lobe. However, there was no significant
difference in liver volume in the patients with or without obstructive jaundice.
Apoptosis was observed in the embolized lobe. CONCLUSIONS: Preoperative
transcatheter portal embolization with percutaneous transhepatic biliary drainage
for the purpose of liver regeneration would be useful for treating extended
hepatectomy with obstructive jaundice.
PMID- 10690614
TI - 13CO2 excretion in breath of normal subjects and cirrhotic patients after 13C
aminopyrine oral load. Comparison with MEGX test in functional differentiation
between chronic hepatitis and liver cirrhosis.
AB - BACKGROUND/AIMS: Liver function can be evaluated using 13C breath tests that
explore liver Cytochrome P450 activity. Aminopyrine is one of the first compounds
used in liver function testing. Lidocaine metabolism to monoethylglycinexylidide
is also a valid tool to assess liver function. Although liver Cytochrome P450
metabolizes both compounds, lidocaine metabolism is flow-dependent while
aminopyrine metabolism does not depend on liver blood flow. METHODOLOGY: The 1st
part of the study evaluated the appearance and disappearance rate of 13CO2 in the
breath of both normal subjects and in cirrhotic patients, so as to establish
optimal sampling times and to evaluate the amount of time needed before
performing a subsequent breath test. The 2nd part of the study compared the
aminopyrine breath test with the monoethylglycinexylidide test in patients with
chronic hepatitis or cirrhosis. RESULTS: Complete 13CO2 disappearance was
recorded 24 hours after the test in normal subjects, while it took 3 days to
disappear from the breath of cirrhotic patients. Breath sampling at 60, 120 and
180 min were equally valid in differentiating chronic hepatitis from cirrhosis.
The aminopyrine breath test and monoethylglycinexylidide test showed a good yet
not close correlation. CONCLUSIONS: This study showed that in cirrhotic patients
a 13C breath test can be performed 3 days after the previous one. In chronic
hepatitis and cirrhotic patients, the aminopyrine breath test and the
monoethylglycinexylidide test evaluated similar, but not identical, hepatic
subfunctions, suggesting that multiple 13C breath test using different substrates
could explore liver function better.
PMID- 10690615
TI - Prognostic factors following liver resection for hepatic metastases from
colorectal cancer.
AB - BACKGROUND/AIMS: We aimed to identify prognostic factors that may allow better
patient selection for liver resection for colorectal liver metastases.
METHODOLOGY: A retrospective analysis of the files of 120 patients undergoing
liver resection for colorectal metastases between 9/85 and 12/96 was performed.
Survival and disease-free survival were calculated, and a uni- and multivariate
analysis for the prognostic impact of various perioperative factors on survival
was performed. RESULTS: Perioperative morbidity and mortality were 28.3% and 5.8%
respectively. Median overall survival was 30 months with a 5-year survival rate
of 31%. Radicality was the prime prognostic determinant. In patients with R0
resection, a liver metastasis of > 3.5 cm in diameter was the only independent
factor associated with an adverse prognosis. CONCLUSIONS: Liver resection for
colorectal liver metastases should be attempted if complete resection with clear
margins is feasible and may be especially beneficial in patients with small (< or
= 3.5 cm) lesions.
PMID- 10690616
TI - The effect of albendazole on the prevention of secondary hydatidosis.
AB - BACKGROUND/AIMS: Secondary hydatidosis and recurrence are serious complications
in hydatid surgery. Although medical treatment and current surgical techniques
are more effective in the prevention of cyst formation resulting from spillage of
cystic liquid, secondary hydatidosis is still surgically important. Albendazole,
a derivative of benzoimidazole, is the most commonly used drug in the medical
treatment of echinococcosis. The effectiveness of pre-operative prolonged or
single dose applications is supported by the literature. METHODOLOGY: Twenty-two
cases of hepatic hydatidosis are evaluated and treated by surgery. Perioperative
albendazole treatment was given in a dose of 12-15 mg/kg/day in 4 divided doses.
The treatment began 5-20 days before the surgery and continued 3-7 months in a
cyclic monthly form, until latex agglutination tests were negative. In the
postoperative period, hematological, ultrasonography and computed tomography scan
evaluation was carried out. The follow-up period for 21 patients was 6-31 months
(mean: 20.52 months). RESULTS: There was no secondary hydatidosis, recurrence or
mortality in this study. Early and late morbidity rates were 4.54% and 13.63%
respectively. CONCLUSIONS: Our results support that perioperative albendazole
treatment is effective in the prevention of secondary hydatidosis.
PMID- 10690617
TI - Immunological analysis in xenogeneic fetal porcine liver transplantation into a
beagle.
AB - BACKGROUND/AIMS: While allogeneic organ transplantation has been performed
safely, a major barrier in xenogeneic transplantation is how to inhibit
hyperacute rejection. METHODOLOGY: We challenged xenogeneic fetal liver
transplantation from pig to dog. The graft was investigated by
immunohistochemical analysis on recipient's IgG, IgM and C3. RESULTS: In 1 of 4
cases, the graft escaped hyperacute rejection for about 4 hours after
transplantation, however, the recipient died next day due to hemorrhage from the
torn capsule of the liver due to the arterial blood pressure of the recipient.
Histologically, the parenchyma showed good countenance and no congestion nor
hemorrhage was shown in the vessels. On immunohistochemical analysis, canine IgG,
IgM and C3 were deposited on the sinusoidal epithelium of the fetal liver more
moderately than that of adult control. Fetal porcine liver showed less expression
of major histocompatability complex class I antigen than that of the adult one.
CONCLUSIONS: We consider that the hyperacute rejection occurred more slowly in
xenogeneic fetal liver transplantation than in the adult one due to not only less
expression of major histocompatability complex class I, but also lower expression
of the epitope recognized by a natural antibody of the recipient.
PMID- 10690618
TI - Marginal donors in liver transplantation.
AB - The use of marginal donors has become very common in many liver transplantation
units due to the increase in the number of possible recipients. Experience has
shown that previous donor protocols were too restrictive. Meanwhile, formerly
unknown factors influence current donor evaluation. Different donor factors
affecting the outcome of transplantation have been studied. Current absolute
contraindications are severe macrosteatosis, long ischemia, sepsis, some viral
infections and extra-CNS malignancy. Old age, mild to moderate steatosis, long
ICU stay, altered liver function tests, hypernatremia, hypotension and pressors,
moderately prolonged ischemia and sex mismatch are usually considered relative
contraindications. The result of this wider acceptance policy has been an
increasing number of usable livers without deleterious influences on graft and
patients survival.
PMID- 10690619
TI - Fat absorption after pylorus-preserving pancreatoduodenectomy reconstructed with
Billroth II pancreaticojejunostomy or Billroth I pancreaticogastrostomy.
AB - BACKGROUND/AIMS: The aim of this study was to determine whether Billroth I
pancreaticogastrostomy (PG-I) or Billroth II pancreaticojejunostomy (PJ-II) after
pylorus-preserving pancreatoduodenectomy is associated with better postoperative
fat absorption, based on residual pancreatic exocrine function. Several
reconstructive operations have been employed after pylorus-preserving
pancreatoduodenectomy to maximize postoperative nutrition. However, no single
institution study has been published comparing the reconstructive procedures with
respect to digestion and absorption of fat. METHODOLOGY: Fat absorption was
studied using the 13C-trioctanoin breath test in patients who were grouped
according to the degree of fibrosis of the pancreatic remnant, which was
determined by histologic examination of the resection specimen. The fibrosis was
graded: grade 0, < 10% fibrosis; grade 1, 10-30% fibrosis; and grade 2, > 30%
fibrosis. There were 22 patients in the PG-I group and 22 patients in the PJ-II
group. RESULTS: There were no significant differences between the PG-I and PJ-II
groups in the cumulative excretion of labeled carbon dioxide in the patients with
grade 0 pancreatic fibrosis. The cumulative excretion in the PG-I group was
better than in the PJ-II group in the patients with grade 1 and grade 2
pancreatic fibrosis. CONCLUSIONS: Fat absorption after PG-I is superior to that
after PJ-II in patients with disordered exocrine function of the pancreatic
remnant. Billroth I pancreaticogastrostomy allows more effective utilization of
the exocrine enzymes of the pancreatic remnant due to elimination of the blind
loop characteristic of the Billroth II pancreaticojejunostomy.
PMID- 10690620
TI - Appraisal of two-staged pancreatoduodenectomy: its technical aspects and outcome.
AB - BACKGROUND/AIMS: Leakage from the pancreaticoenteric anastomosis after
pancreatoduodenectomy is closely associated with intraabdominal hemorrhage, thus
contributing to mortality. Recently, two-staged pancreatoduodenectomy including
exteriorization of the pancreatic juice and second-look pancreaticojejunostomy
was performed in high-risk patients. METHODOLOGY: The authors reviewed 24
patients who underwent two-staged pancreatoduodenectomy from November 1994 to
April 1999. RESULTS: Oral intake could be instituted on the 6th (mean)
postoperative day. In 23 of the 24 patients, the pancreatic juice leakage stopped
within a mean of 10 days without any complications. In the remaining 1, the
leakage lasted over 4 weeks and intraabdominal bleeding from the gastroduodenal
artery occurred. The median interval between pancreatoduodenectomy and the second
operation was 124 days (range: 93-323 days). In 15 patients, a stent tube was
placed at the site of pancreaticojejunostomy: 1 patient developed acute
pancreatitis due to dislocation of the stent tube, in 3, pancreatic juice leakage
necessitated exteriorization of the juice, and the remaining 11 recovered
uneventfully. In the other 9 patients, the pancreatic juice was exteriorized: 1
patient had leakage and the other 8 recovered uneventfully. Overall, there was no
mortality. CONCLUSIONS: Our two-staged pancreatoduodenectomy is considered to
make pancreatoduodenectomy performable safely without any mortality. This
procedure is recommended for selected patients, including those who require
concomitant major hepatectomy or resection of other organs or who have liver
cirrhosis, and may be indicated for patients who have a soft and fragile pancreas
or pancreatic trauma.
PMID- 10690621
TI - Intraductal papillary-mucinous tumors: an entity which is infrequent and
difficult to diagnose.
AB - BACKGROUND/AIMS: Intraductal papillary-mucinous tumor of the pancreas is
currently considered to be a tumor which is an entity of its own, different from
classic pancreatic ductal carcinoma. It is basically characterized by slow growth
and low malignancy potential, as well as by the production of mucin. The aim of
this study is to contribute to world literature some clarification of its natural
history, clinical presentation, the most useful diagnostic tests, methods of
detection of stromal invasion and handling of treatment. METHODOLOGY: Of 297
pancreatectomies undertaken at the "12 de Octubre" hospital between May 1985 and
January 1998, only 1 case of Intraductal papillary-mucinous tumor was found. We
have revised 127 cases published in 10 series over the last 10 years. We also
contribute a review of our own case. RESULTS: These tumors, which are very
infrequent, produce non-specific symptoms, with long latency periods from the
first symptom up to stromal invasion. Endoscopic retrograde
cholangiopancreatography showed alterations in 100% of cases where this was
undertaken. Tumor-related mortality was zero amongst patients with non-invasive
tumor who underwent surgery. None of the cases published presented upper
gastrointestinal hemorrhage. This indicated the correct surgery and led us to our
diagnosis. CONCLUSIONS: We confirm the low frequency and difficulty of diagnosis,
the sensitivity of endoscopic retrograde cholangiopancreatography, the difficulty
of early detection of stromal invasion, and the high survival rate in cases where
resection is done before this occurs. Early diagnosis and treatment is therefore
of utmost importance.
PMID- 10690622
TI - Introduction of proton pump inhibitors--consequences for surgical treatment of
peptic ulcer.
AB - BACKGROUND/AIMS: This retrospective study analyzes the influence of different
factors on morbidity and mortality after surgical treatment of peptic ulcer.
METHODOLOGY: At the Municipal Hospital of Offenbach, Germany, from 1985-1996, 485
patients underwent surgery. RESULTS: Of the 485 patients, 70.7% (343) were
diagnosed to have duodenal ulcer and 29.2% (142) had suffered from gastric ulcer.
During this period, 79.2% (384) of the operations were performed under emergency
conditions because of acute complications (56% of these with perforation, 20%
with penetration, 24% with ulcer bleeding), whereas the rest was done electively.
Two hundred and ninety-one (60%) patients were male, the average age was 59 years
and 71.7% (348) of the patients had certain concomitant diseases. We observed
complications in 48% of the cases with a total postoperative mortality of 21%.
CONCLUSIONS: Between 1985 and 1996 the total number of ulcer surgeries performed
at the Municipal Hospital Offenbach per year has stayed almost constant. However,
a definite increase of acute operations in addition to a decrease of elective
interventions was noticed. The dissatisfying results of surgical treatment of
peptic ulcer after the introduction of proton pump inhibitors seems to be the
consequence of the negative selection of patients mentioned above. A connection
could be proved between the age and condition of the patient, the type of the
surgical intervention (acute or elective) and the morbidity and mortality after
the surgery.
PMID- 10690623
TI - Neutrophil functions and cytokine production in patients with gastric cancer.
AB - BACKGROUND/AIMS: One of the most important factors in the prevention of
postoperative infection is the patient's own capacity to protect against
infection. Neutrophils play a major role in this protection through phagocytosis
and superoxide generation. Inflammatory cytokines are suitable for estimating the
degree of surgical stress. The present study was designed to elucidate whether
neutrophil functions are impaired in gastric cancer patients, and are related
with cytokine production after surgery. METHODOLOGY: Phagocytosis and superoxide
generation by neutrophils was studied in 84 patients with gastric cancer by flow
cytometry. IL-6, IL-8 and tumor necrosis factor alpha were studied in 18 patients
with gastric cancer by enzyme-linked immunosolubent assay. RESULTS: In gastric
cancer patients phagocytosis was not impaired, whereas superoxide generation was
lower than benign diseases and it was inhibited relative to the clinical stage.
Moreover, superoxide generation was correlated with the nutritional parameters
and was more suppressed in 7 patients who suffered from postoperative infection
than in 40 patients whose postoperative course were uneventful. The fluctuation
of superoxide generation correlated well with the serum cytokine levels in the
postoperative course and its correlation was clarified in vitro. Nine patients
with gastric cancer received intravenous hyperalimentation, and their superoxide
generation was increased. CONCLUSIONS: Superoxide generation by neutrophils was
suppressed in gastric cancer patients and it is suggested that nutritional
support prevents postoperative infection via the augmentation of superoxide
generation.
PMID- 10690624
TI - Angiogenesis inhibitor, TNP-470, suppresses growth of peritoneal disseminating
foci.
AB - BACKGROUND/AIMS: Angiogenesis is critical not only for growth of primary tumors
but also for cells established at distant organs. We investigated the effects of
angiogenesis inhibitor, TNP-470, on the establishment and growth of
intraperitoneally inoculated human gastric cancer cell line, MKN-45, and survival
of nude mice with this tumor. METHODOLOGY: Human gastric cancer cell line, MKN
45, were injected into the peritoneal cavity of an ICR nude mouse and a model of
peritoneal dissemination was developed. TNP-470 was injected subcutaneously every
other day from day 1 until sacrifice or death. The effects of TNP-470 on MKN-45
cells were also examined in vitro. RESULTS: Although the number of disseminated
foci was not significantly different, the maximum size was significantly smaller
in a TNP-treated group than those of a control. Survival time was significantly
longer in a TNP-treated group. TNP-470 demonstrated no growth inhibition of MKN45
cells in vitro. CONCLUSIONS: Those results suggested that anti-angiogenic agent,
TNP-470, might be effective in treating peritoneal dissemination of gastric
cancer by inhibiting growth of the seeded tumor cells on the peritoneum.
PMID- 10690625
TI - CAg 25: a novel tumor-associated mucin antigen.
PMID- 10690626
TI - Measles IgA in the nasal washings of adult volunteers and children immunized
intranasally with measles vaccine L-16.
AB - Earlier it was determined that inspiration of aerosolized measles vaccines may be
as effective as its injection in induction of measles antibodies formation. In
the beginning of measles infection the measles virus penetrates through mucosa of
nose, mouth or eyes of children. So it seems rational to use a nasal spray of
measles vaccine to induce "mucosal immunity" in the nasopharinx. Local IgA
measles antibodies formation was observed only after measles vaccine spray
immunization of 6-7 year old children or adult volunteers. The same level of sera
measles antibodies was observed in immunized people after intranasal or
subcutaneous measles vaccination. Special investigation of measles vaccination
side effects in adults revealed that the injected vaccine suppressed lymphocytes
functional capacity much more than when intranasally introduced. Intranasal
measles vaccine spray introduction may be a useful method of child revaccination
in the process of measles eradication. This method is useful for investigation of
"mucosal immunity" in children or adults.
PMID- 10690627
TI - Characterization of monoclonal antibody CIBCNSH3 generated to the human EGF
receptor.
AB - Monoclonal antibody CIBCNSH3 of IgG1 isotype has been generated against human
epidermal growth factor receptor (EGFR) using MDA MB 468 breast carcinoma cell
line as immunogen. Earlier studies have revealed that this MAb blocked growth
factor-receptor interaction and thus inhibited cell proliferation and tumor
growth. In the present paper, this MAb has been extensively characterized to
evaluate its application in the study of human cancers. The results were compared
with those obtained using a control MAb ICR 62 specific to EGFR. Competitive
assay showed that this MAb bound to an epitope in the extracellular domain of the
EGFR to which MAb ICR 62 also bound. This MAb immunoprecipitated the 170 kD
glycoprotein. The specificity was further confirmed by the formation of a single
discrete band in western blot analysis. By flow cytometric analysis this
monoclonal antibody revealed high binding affinity with MDA MB 468 cells. By
immunocytochemical assay, out of 35 breast tumors studied, 40% were found to
exhibit strong cell membrane staining and in the case of 25 oral cancers studied,
56% were strong positive. High expression of EGFR was observed in MDA MB 468
cells and HN 5 cells. These studies clearly indicate that MAb CIBCNSH3 might
prove useful to identify tumors with high level of expression of EGFR associated
with poor prognosis.
PMID- 10690628
TI - Evaluation of the BT-1 serum assay for breast cancer.
AB - The BT-1 assay which identifies a novel breast tumor associated serum analyte was
performed for 143 patients previously diagnosed with breast cancer. Mucin tumor
markers CA15-3/CA27-29 values were available for 50 patients and there was very
minor overlap between patients positive by both tests. Patients' follow-up
clinical status at sample draw was compared to BT-1 assay results. 27% of
patients originally diagnosed as Stage II and 20% patients originally diagnosed
as Stage III who were evaluated 'no disease' had positive BT-1 values. 8%
patients diagnosed as Stage II had negative BT-1 results in samples drawn within
90 days of chemotherapy initiation, whereas 23% of patients diagnosed as Stage
III cancer were BT-1 test positive within 90 days of chemotherapy initiation. 50%
of patients tested before initial breast cancer surgery had positive BT-1 values,
suggesting that the BT-1 assay may be useful in identification women with more
advanced disease at diagnosis.
PMID- 10690629
TI - Limited usefulness of antithyroperoxidase and antithyroglobulin assays in
Jamaicans with Graves' disease.
AB - The clinical usefulness of commercially prepared haemagglutination kits for
thyroperoxidase (TPO) antibody and thyroglobulin (TG) antibody was evaluated in
145 consecutive Jamaicans with Graves' disease. Sixty two (43%) of the patients
were newly diagnosed, 12 (8%) were in remission and 71 (49%) had relapsed. Sera
from 65 (45%) patients were positive for thyroid antibodies. The TPO antibodies
were found in 43% (63/145), thyroglobulin antibodies in 12% (17/145) fifteen
(10%) patients had both anti-TPO and TG antibodies. Similar prevalences of TPO
antibody were found in newly diagnosed patients and those who had relapsed (44%
v. 41%) but the prevalence in the patients in remission was significantly higher
(75%; X2 = 4.8, P < 0.05). The prevalence of TPO antibody increased significantly
with age at onset before age 35 years compared to later onset (56% v. 32%; X2 =
8.09, P < 0.005). The presence of both TPO antibody (64% v. 31%; X2 = 13.1, P <
0.001) and TG antibody (22% v. 6%; X2 = 8.8, P < 0.005) correlated positively
with Graves' ophthalmopathy. Neither of the tests was adequately sensitive in
detecting GD in Jamaicans but we recommend testing for TPO antibody without TG
antibody as a cost-effective approach. The presence and titres of TPO antibody
and TG antibody do not correlate with disease activity and are not reliable
enough for monitoring antithyroid drug therapy in GD. There is a need for
antibody tests which are efficacious in diagnosing and monitoring antithyroid
drug therapy in GD, and suitable for use in developing countries.
PMID- 10690630
TI - From IgG monoclonals to IgM-like molecules.
AB - One problem in blood group testing is that IgG monoclonal antibodies, in contrast
to IgM, do not usually agglutinate erythrocytes. One of the reasons is the high
zeta potential induced by the negative charge of the cell surface. During the
last few years, we have produced a series of human monoclonal antibodies by the
conventional fusion technique directed against antigens of the Rh blood group
system. Some of these monoclonals, especially those directed against Rh-subgroups
such as the c-antigen, were mainly of the IgG-subtype and unsuitable for
agglutination tests. We have therefore tried to establish a molecular biological
method to make IgM-like molecules from IgG monoclonals. From the c-antigen
specific human hybridoma BS 240 (IgG subtype), we isolated mRNA that was
transcribed into cDNA and then amplified by PCR using family specific primers.
The heavy and light chain products were cloned into the pHen vector containing a
DNA linker fragment, a myc-tag for identification and a His-tag for purification.
After transformation in E.coli and phage rescue with helper phage, the culture
supernatant was screened for antigen positive recombinant phage antibodies as a
first control for specificity using c-antigen positive erythrocytes and anti-M13
antibodies as bridging antibodies (Coombs technique). Erythrocytes being negative
for the c-antigen served as a negative control. After changing the culture
conditions, soluble single chain fragments (scFv) were obtained from the
periplasmatic extract. Specificity was shown using the c-antigen positive and
negative erythrocytes and the 9E10 antibody (anti-myc) as a bridging antibody. To
obtain IgM-like molecules, DNA coding for the specific scFv was cloned into the
vector pSTE containing DNA coding for the monomer of core streptavidin. After
expression, purification and refolding of the monomer, the core streptavidin
combines to form tetrameric structures, termed scFv::strep, that are able to bind
biotin as shown using ELISA plates coated with biotinylated BSA. Binding was
detected with 9E10 and a peroxidase conjugated secondary antibody. In the
agglutination assay, the construct was able to agglutinate c-antigen positive
erythrocytes but not the negative erythrocytes. These experiments show that it is
possible to construct IgM-like agglutinating molecules from cells containing
secreting IgG antibodies. Experiments employing human antibody libraries instead
of hybridoma cell lines are now in progress.
PMID- 10690631
TI - Studies on p53 immunolocalisation in breast cancer and its prognostic
significance.
AB - Immunocytochemical localisation of mutant p53 in breast tumours serves as a
potential prognostic molecular marker. In order to study the expression of p53
protein in breast cancer which constitutes the second most common malignancy in
the South Indian female population, MAb CIBCVMC12 has been generated against
human p53 protein isolated and purified from bacterial cell lysate of E.coli
carrying the plasmid T 7-7 Hup53 grown in Luria broth to induce the expression of
p53. The positive clones selected by ELISA were found to exhibit strong staining
of nuclear p53 in both fresh and archival paraffin embedded breast tumour tissue
sections. Commercial MAb D 07 against p53 was used as control. In
immunoprecipitation, this MAb of IgG2b isotype was found to bind specifically to
a protein of 53 kD. Immuno cyto chemical assay of normal, benign and malignant
breast tissues of different histological types revealed that the majority of
tumour cells were strong positive in the case of infiltrating ductal and lobular
carcinomas, the staining being less intense for in situ carcinoma. The test for
normal and benign tissues was negative. The staining patterns were comparable
with those of control antibody. These results suggest that the MAb generated is
specific to p53. The p53 protein expression was compared with the estrogen
receptor (ER) status for 50 breast tumours which revealed that 38% of these were
p53 positive and of these two were ER+. Among the p53 negative tumours, 48% were
found to be ER+. A comparison of the p53 expression for 100 breast cancer
patients indicated that 57% of the tumours were p53 negative and these patients
had a longer overall 5 year survival rate and recurrent free interval which is
statistically very significant. These results might suggest that p53 positive
tumours are more aggressive biologically with poor prognosis.
PMID- 10690632
TI - Analysis of VH and VL genes of a monospecific human anti-myosin antibody produced
by a B cell from the primary repertoire.
AB - Epstein-Barr virus (EBV) transformation of B lymphocytes from a Glanzmann's
thrombasthenia patient with a serum antibody to the integrin alpha IIb beta 3,
led to the immortalization of a B cell secreting a monospecific IgM monochonal
antibody (MAb), B7, reactive with platelet myosin. Analysis of B7 V genes
revealed minimally mutated sequences: the immortalized B cell issued from the
primary repertoire, with no evidence of an in vivo selection by myosin. The V
genes were here compared with sequences of human MAbs available on databases to
more clearly understand the monospecificity of the B7 MAb. B7 V genes were
closely identical to rearranged V genes in clones with self-specificities, often
secreting polyreactive antibodies. In contrast, B7 is an unmutated monoreactive
human MAb able to recognize myosin with a high avidity. Comparison of the CDR3H
sequence with that of MAbs in databases supports a central role for the CDR3H
subdomain in determining monospecificity. Our results suggest the existence of a
monospecific autoreactive B cell compartment, besides the well-known polyspecific
one, susceptible to be the template of pathogenic autoreactivity, characterized
by antibodies of high affinity and specificity.
PMID- 10690633
TI - Is the HemK family of putative S-adenosylmethionine-dependent methyltransferases
a "missing" zeta subfamily of adenine methyltransferases? A hypothesis.
AB - Previous comparative studies revealed close similarity among various groups of S
adenosyl-L-methionine (AdoMet)-dependent methyltransferases (MTases), indicating
their common evolutionary origin. We present evidence for a remarkable similarity
between the sequence and predicted structure of HemK (a widespread family of
putative proteins encoded in genomes from bacteria to humans) and the catalytic
domain of the gamma-subfamily of adenine-specific DNA MTases (N6mA MTases). We
predict the structure and function of the putative catalytic domain of HemK
proteins and speculate that the target-recognizing function may be conferred by
the N-terminal variable region.
PMID- 10690634
TI - Speaking out of turn: a role for silent synapses in pain.
AB - Severe tissue or nerve injury can result in a chronic and inappropriate sensation
of pain, mediated in part by the sensitization of spinal dorsal horn neurons to
input from primary afferent fibers. Synaptic transmission at primary afferent
synapses is mainly glutamatergic. Although a functioning excitatory synapse
contains both alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA)
and N-methyl-D-aspartate (NMDA) receptors in the postsynaptic membrane, recent
evidence suggests that dorsal horn neurons contain some "silent" synapses, which
exhibit purely NMDA receptor-mediated evoked postsynaptic currents and do not
conduct signals at resting membrane potential. Serotonin, which is released onto
dorsal horn neurons by descending fibers from the rostroventral medulla,
potentiates sensory transmission by activating silent synapses on those neurons,
i.e., by recruiting functional AMPA receptors to the postsynaptic membrane. This
phenomenon may contribute to the hyperexcitability of dorsal horn neurons seen in
chronic pain conditions.
PMID- 10690635
TI - G beta gamma-mediated signaling: new therapeutic target for proliferative
vascular disease.
AB - Proliferation of vascular smooth muscle (VSM) severely affects the outcome of
coronary artery bypass and angioplasty procedures, causing the failure of venous
grafts or restenosis of the reopened vessel. Investigation into the mechanisms
underlying the process of VSM cellular proliferation has provided evidence that
intracellular signaling mechanisms triggered by extracellular hormonal factors
acting through G protein-coupled receptors, can mediate and sustain this
pathological process. Inhibition of common pathways of G protein-coupled receptor
signaling has recently proven effective in preventing VSM cellular activation and
proliferation. In particular, inhibition of the G beta gamma-mediated mitogen
activated protein (MAP) kinase signaling pathway results in the inhibition of VSM
proliferation in vitro. Moreover, use of adenoviral vectors to deliver a peptide
inhibitor of G beta gamma signaling in vivo has resulted in inhibition of intimal
hyperplasia in experimental models of vein-graft failure and restenosis.
PMID- 10690636
TI - Insulin-induced oxidative neuronal injury in cortical culture: mediation by
induced N-methyl-D-aspartate receptors.
AB - While effectively attenuating neuronal apoptosis in mouse cortical culture,
insulin paradoxically induced neuronal necrosis with 48 h of exposure. The
insulin neurotoxicity was blocked by an antioxidant but not by caspase
inhibitors. Exposure to insulin led to tyrosine phosphorylation of the insulin
receptor and the insulin-like growth factor-1 (IGF-1) receptor and activation of
protein kinase C (PKC) and phosphoinositide 3-kinase (PI3-kinase). Inhibitors of
tyrosine kinase and PKC, but not PI3-kinase, attenuated the insulin
neurotoxicity. Conversely, the inhibitor of PI3-kinase but not PKC reversed the
antiapoptotic effect of insulin. Suggesting that the gene activity-dependent
emergence of excitotoxicity contributed to insulin neurotoxicity, macromolecule
synthesis inhibitors and N-methyl-D-aspartate (NMDA) antagonists blocked it.
Consistently, exposure to insulin increased the level of the NR2A subunit of the
NMDA receptor without much altering NR1 or NR2B levels. The present study
suggests that insulin can be both neuroprotective and neurotoxic in the same cell
system but by way of different signaling cascades.
PMID- 10690637
TI - Direct transcriptional control of the chloroplast genes psbA and psaAB adjusts
photosynthesis to light energy distribution in plants.
AB - Two photosystems, I and II, absorb and convert light energy in photosynthesis in
chloroplasts of green plants. The genes psbA and psaAB of the cytoplasmic
chloroplast genome encode core components of photosystem II and photosystem I,
respectively. Here we show that the absolute amounts of photosystem I and
photosystem II respond, in a complementary manner, to changes in light quality
that preferentially excite each photosystem in mustard seedlings. We also show
that the initial response to altered energy distribution is a change in the rates
of transcription of psbA and psaAB. Changes in chlorophyll fluorescence emission
in vivo suggest that the signal initiating this change is the oxidation-reduction
state of plastoquinone, a component of the photosynthetic electron transport
chain that connects photosystem I and photosystem II. The results are consistent
with transcriptional effects observed previously with chloroplasts isolated in
vitro and demonstrate that redox control of chloroplast transcription initiates
long-term adjustments that compensate for imbalance in energy distribution and
adapt the whole plant to altered light environments.
PMID- 10690638
TI - Identification of nuclear matrix and associated proteins that bind the
haptoglobin gene cis-element.
AB - To identify the major nuclear matrix proteins that bind to the rat haptoglobin
gene cis-element, we isolated a soluble nuclear matrix protein fraction and
analysed it by gel retardation. Two major DNA-binding proteins exhibiting
different types of protein-DNA interactions were detected: a DNA sequence
specific 32-kDa isoform of transcription factor C/EBP beta, and a nuclear matrix
protein p55 that bound to the DNA nonspecifically. During increased transcription
of the haptoglobin gene in the course of the acute-phase reaction, the DNA
binding affinities and concentrations of these proteins in the soluble nuclear
matrix fraction were increased. These data lend further evidence that the nuclear
matrix is an active support structure that localizes gene regulatory proteins and
participates in transcriptional regulation.
PMID- 10690639
TI - Immunochemical determination of cellular content of translation release factor
RF4 in Escherichia coli.
AB - The biosynthesis of proteins in prokaryotes is terminated when a stop codon is
present in the A-site of the 70S ribosomal complex. Four different translation
termination factors are known to participate in the termination process. Release
factor RF1 and RF2 are responsible for the recognition of the stop codons, and
RF3 is known to accelerate the overall termination process. Release factor RF4 is
a protein involved in the release of the mRNA and tRNA from the ribosomal
complex. Furthermore, RF4 is involved in the proofreading in the elongation step
of protein biosynthesis. The cellular contents of RF1, RF2, and RF3 were
determined earlier. Here we report the cellular content of RF4 in Escherichia
coli to be approximately 16,500 molecules per cell. The cells were grown in a
rich medium and harvested in the beginning of the exponential growth phase. The
quantifications were performed by using Western immunoblotting with radioactive
iodinated streptavidin and biotinylated rabbit anti-mouse immunoglobulins plus a
highly specific monoclonal antibody against RF4 as first antibody.
PMID- 10690640
TI - Activation of the acidic isoform of phospholipase A2 from Naja mossambica
mossambica venom by oleoyl imidazolide requires the cooperative action of two
ionizing groups.
AB - The acidic phospholipase A2 isoform from the spitting cobra Naja mossambica
mossambica is activated irreversibly by treatment with a molar equivalent of
oleoyl imidazolide. The kinetics of the chemical modification of the enzyme can
also be monitored by measuring the large reduction of tryptophan fluorescence,
which is accompanied by a distinct red shift. The addition of a single molar
equivalent of oleic acid to the enzyme produces an instantaneous reduction in
fluorescence but with a barely detectable red shift, confirming that the response
to oleoyl imidazolide results from covalent modification of the protein rather
than hydrolysis of the reagent. The pH dependence of both activation and
fluorescence reduction by oleoyl imidazolide has an optimum rate near pH 8.0. We
propose that long-chain fatty acids and long-chain acyl imidazolides bind at a
single activation site and that the reaction of the imidazolides involves two
protein residues, one of which is a nonessential histidine residue and the other
a primary amino group.
PMID- 10690641
TI - 5'-upstream structure of the gene coding for chicken riboflavin-binding protein
and its relation to estrogen induction.
AB - To elucidate the mechanism of the estrogen-dependent induction of chicken
riboflavin-binding protein (RfBP), we analyzed the 5'-upstream structure of its
gene. A noncoding exon exists there, and around this sequence, 9 widely spaced
half-palindromic estrogen-response element (ERE) motifs (5'-GGTCA or 5'-TGACC)
were found. Furthermore, an imperfect ERE-like palindromic sequence (5'
ATGTCANNNTGACAT-3') was also found at the 2.25 kb upstream region. No consensus
palindromic ERE was observed. By luciferase reporter assay, the regions
containing the half ERE motifs and the imperfect ERE showed estrogen-dependent
enhancer activities, suggesting that these two characteristic sequences might
confer estrogen-inducibility upon the chicken RfBP gene. However the activities
were lower than that of a consensus ERE. It remains uncertain whether these
sequences act cooperatively.
PMID- 10690642
TI - Existence of multiple novel Gs alpha splice variants in acute leukemia patients.
AB - The alpha subunit of the stimulatory G protein, Gs alpha, is involved in
stimulation of the adenylate cyclase pathway of signal transduction. In this
study, we investigated the status of the Gs alpha gene in 29 acute leukemia
patients and identified three novel splice variants (designated Gs alpha L-1, Gs
alpha L-2, and Gs alpha L-3), possibly derived from aberrant splicing. All of the
splice variants have in-frame deletions, removing the functional domain
responsible for GTPase activity of Gs alpha, and would encode truncated proteins
of 160(Gs alpha L-1), 90(Gs alpha L-2) and 70(Gs alpha L-3) amino acids,
respectively. The data suggest that these novel products may be implicated in an
as-yet-unidentified signal transduction pathway in hematopoietic cells.
PMID- 10690643
TI - Rearrangement in the coding and 5' region of p53 gene in human oral tumors.
AB - Different postreplicative, transcriptional, and translational mechanisms
responsible for p53 gene inactivation are slowly unfolding. Rearrangement of the
p53 gene is a very rare event in human solid tumors and has been reported only in
osteosarcomas. From our laboratory we have recently reported rearrangement only
in the coding region of the p53 gene in breast tumors. In this report we have
undertaken a systemic investigation of p53 in oral tumors. Results have shown
rearrangement in the coding region of p53 in 20% of cases and in the 5' region of
p53 gene in approximately 8% of cases. No allelic loss and amplification of p53
gene was observed in these tumor samples. In our earlier studies on breast
tumors, we found no abnormality in the 5' region of p53. However, in the present
study we report for the first time rearrangement in the 5' region of p53 in oral
tumors. Correlation of p53 gene rearrangement with p53 expression of RNA and
protein indicates that rearrangement in the 5' region of p53 might not have a
role in p53 expression. However, rearrangement in the coding region of p53 might
play a critical role in controlling p53 gene activity in the process of
tumorigenesis.
PMID- 10690644
TI - Blockage of HIV-1 production through inhibition of proviral DNA synthesis by N,O
didecanoyl serinal dimethylacetal.
AB - Six serinal derivatives were synthesized and tested for their anti-human
immunodeficiency virus type-1 (HIV-1) activity against HIV-1-infected cells. Of
the 6 serinal derivatives tested, only N,O-didecanoyl serinal dimethylacetal
(DDSD) was found to strongly suppress progeny virus production from acute HIV-1
infected CEM cells, while not suppressing the HIV-1 p24 production from latent
HIV-1-infected ACH-2 cells after stimulation with phorbol 12-myristate 13
acetate. DDSD also inhibited the synthesis of HIV-1 proviral DNA at 20-50 microM,
not only 1 h but also 24 h after HIV-1 infection. Taken together, DDSD is a
potent inhibitor of HIV-1 production, and may become a unique leading compound
for chemotherapy of acquired immunodeficiency syndrome.
PMID- 10690645
TI - Real-time oligonucleotide hybridization kinetics monitored by resonant mirror
technique.
AB - The kinetics of hybridization of 11-meric and 14-meric oligonucleotides,
dTGGGAAGAGGG (ODN-11) and dTGGGAAGAGG GTCA (ODN-14), with 14-meric
oligonucleotide dpTGACCCTCT TCCCA (p14) attached to the surface of a cuvette was
studied by the resonant mirror method. The treatment of the experimental curves
with exponential equations leads to the following values for association (kas)
and dissociation (kdis) rate constants at 25 degrees C: kas = 219 +/- 39 and 183
+/- 162 M-1 s-1, kdis = (2.0 +/- 0.4) x 10(-3) and (4 +/- 1) x 10(-4) s-1 for the
duplexes (p14) x (ODN-11) and p14 x (ODN-14), respectively. The oligonucleotide
dTGCCTTGAATGGGAA GAGGGTCA (ODN-23), which forms a hairpin structure, does not
associate with p14. The data were compared with the results of melting curve
detection and temperature-jump experiments. The association rate constants for
ODN-11 and ODN-14 are much slower than those values in homogeneous aqueous
solution. The dissociation rate constants have the same magnitude values as
estimated by using association constants measured from melting curves but differ
from the values estimated in temperature-jump experiments.
PMID- 10690646
TI - Effect of rooperol on collagen synthesis and cell growth.
AB - The effect of rooperol on type I collagen synthesis in normal skin and lung
fibroblasts and cell growth in normal and transformed fibroblasts was
investigated. Low concentrations of rooperol selectively inhibited the growth of
transformed cells while stimulating collagen synthesis in normal fibroblasts.
Elevated collagen synthesis and deposition could impede tumour cell invasion and
metastasis, implying that rooperol may be useful as an antimetastatic agent in
the treatment of cancer.
PMID- 10690647
TI - Substitution of surface-exposed framework residues alters secretion of
recombinant fusion protein Fv/tumor necrosis factor in Escherichia coli.
AB - Substitution of hydrophobic residues with hydrophilic ones at surface-exposed
positions may influence the yield of antibody fragment expression in Escherichia
coli by reducing its aggregation potential. We introduced such substitutions at 8
surface-exposed framework region residues of a fusion protein Fv/Tumor Necrosis
Factor, which resulted in the expression of 10 mutant fusion proteins (Mut 1-10)
in E. coli. Our results showed that expression levels of Mut 1-3, with mutations
of A9S, T18K, and G41D, respectively, decreased by 4- to 8-fold, whereas
expression levels of Mut 4, 9, and 10, with mutations of S60D/S70D, T28D, and
G65D, respectively, were not affected. In contrast, mutation of F83A at light
chain residue 83, which is usually buried at the variable/constant domain
interface of antibody molecules but becomes surface-exposed in recombinant Fv
molecules, increased the expression level of Mut 5 by 4-fold. Our results suggest
that this important substitution of a hydrophobic residue with a hydrophilic one
may also be applied to increase the secretion of other recombinant Fv molecules
in E. coli periplasm.
PMID- 10690648
TI - Use of chimeric forms of neuronal nitric-oxide synthase as dominant negative
mutants.
AB - Because the functional form of neuronal nitric-oxide synthase (nNOS) is a
homodimer, we investigated whether we could disrupt dimer formation with inactive
nNOS chimeras acting as dominant negative mutants. To test this hypothesis, we
either expressed the heme and reductase regions of rat nNOS as single domains or
produced fusion proteins between the rat nNOS heme domain and various other
electron-shuttling proteins. A dominant negative potential of these constructs
was demonstrated by their ability to reduce NOS activity when transfected into a
cell line stably expressing rat nNOS. In the presence of these nNOS mutant
proteins, cellular levels of inactive nNOS monomers were significantly increased,
indicating that their mechanism of action is through the disruption of nNOS dimer
formation. These dominant negative mutants should prove valuable in analyzing the
role of nNOS in biological systems.
PMID- 10690649
TI - Biochemical properties of the protein tyrosine kinase of the bacterium
Acinetobacter johnsonii.
AB - The biochemical properties of the autophosphorylating protein tyrosine kinase of
Acinetobacter johnsonii were analyzed in vitro. The study shows that the optimal
pH value for the phosphorylation reaction is approximately 7. The enzyme activity
is stimulated by magnesium and, to a lesser extent, by manganese ions, whereas
calcium ions have no effect. The phosphorylation process is rapid reaching a
maximum in < 2 min, and the enzyme is modified at multiple sites. Interestingly,
the bacterial enzyme is insensitive to a series of molecules known to affect the
activity of eukaryotic protein tyrosine kinases: genistein, quercetin,
tosyllysine chloromethyl ketone, and vanadate. We concluded that, even though the
overall phosphorylation reaction catalyzed by the A. johnsonii enzyme is
identical to that occurring in eukaryotes, this bacterial kinase exhibits a
number of specific properties and therefore probably belongs to a separate group
in the general family of protein tyrosine kinases.
PMID- 10690650
TI - Cloning and characterization of manganese superoxide dismutase gene from Vibrio
parahaemolyticus and application to preliminary identification of Vibrio strains.
AB - The sodA gene coding for manganese superoxide dismutase (Mn-SOD) from the marine
microorganism Vibrio parahaemolyticus was cloned, sequenced, and overexpressed in
Escherichia coli by use of the pET20b (+) expression vector. The full-length gene
consisted of a 588-bp open reading frame and encoded a polypeptide of 196 amino
acid residues, with a calculated molecular mass of 21,713 Da. The recombinant
enzyme was efficiently purified from crude E. coli cell lysate by metal ion
affinity chromatography. The recombinant VPMn-SOD resisted thermo-denaturation up
to 60 degrees C and was insensitive to such inhibitors as EDTA, NaN3 and
diethyldithiocarbamic acid. The specificity of V. parahaemolyticus Mn-SOD gene
probe was analyzed by cross-species polymerase chain reaction to provide
information for Vibrio strain identification.
PMID- 10690651
TI - Characterization of cytostatically active glycosphingolipids isolated from
thioglycollate-elicited murine macrophages.
AB - Two acidic glycosphingolipids (gangliosides) derived from mouse macrophage
membranes and separated by thin-layer chromatography have a strong cytostatic
effect on human and mouse tumor cells. The structure of the two gangliosides,
named M phi G1 and M phi G2, was elucidated by application of physicochemical and
immunochemical methods. Gas chromatography and mass spectrometry of M phi G1 and
M phi G2 classified them as isomeric monosialogangliosides with ceramide moieties
composed of sphingosine as the long-chain base, C16 and C18 fatty acids,
respectively, and a lacto-tetraose backbone. For M phi G1, additional
immunochemical findings led to the proposed structure IV3NeuAc-nLcOse4Cer. The
immunochemical reactions of M phi G2 suggest a branched structure for the
oligosaccharide moiety.
PMID- 10690652
TI - Production of superoxide and nitric oxide by granulocytes in non-insulin
dependent diabetic patients with and without diabetic nephropathy.
AB - Production of the superoxide radical anion O2-. and the nitric oxide radical NO-.
by granulocytes was studied in 14 patients with type 2 diabetes without
nephropathy, 21 patients with type 2 diabetes and diabetic nephropathy, and 19
healthy subjects, both without and after stimulation with opsonized zymosan. O2-.
production by both resting and stimulated granulocytes was increased in type 2
diabetes patients without nephropathy but decreased in type 2 diabetes patients
with nephropathy, compared with healthy subjects. NO. generation was highly
augmented in type 2 diabetes patients without nephropathy by both resting and
stimulated cells; values for type 2 diabetes patients with nephropathy were
intermediate between the type 2 diabetes patients without nephropathy and the
healthy subjects. These data point to granulocytes as one of possible sources of
oxidative stress in type 2 diabetes.
PMID- 10690653
TI - Failure to attract and retain clinician/scientist faculty puts our profession at
risk.
PMID- 10690654
TI - The road to preventive dentistry--the personal scientific experience of a
Japanese dentist.
PMID- 10690655
TI - Her name is "Lucy", our three-million-year-old ancestor.
AB - Dental anthropology is a key discipline in studies to determine the evolutionary
history of our hominid ancestors, to identify the origin and dispersal of modern
humans, and to reconstruct the source of observed dental variation. A survey of
hominid and modern human evolutionary history, emphasizing results from powerful
multivariate dental morphometric methodologies, suggests a single African origin
of modern humans > 150,000 years before present from a Homo heidelbergensis
ancestor. A continuum among modern humanity is described, with, first, sub
Saharan Africans, then southeast Asian Negrito, and Australian aborigines at its
extant root. Other interpretations of the available data are possible.
Examinations of the progress of the evolution of teeth through time give
significant insight into dental morphogenetics and variation, and the biology of
dental evolution. The mechanisms of evolution which fashion a phenotype and the
methods of molecular and dental phylogenetics are reviewed and evaluated. This is
an exciting time for dental anthropology, with fascinating and challenging
questions to address, but anthropologists, not dentists, dominate the field. The
perspective of a dentist can meaningfully add to the dynamics of dental
anthropology.
PMID- 10690656
TI - Architecture of intact natural human plaque biofilms studied by confocal laser
scanning microscopy.
AB - Determination of the structure of human plaque will be of great benefit in the
prediction of its formation and also the effects of treatment. However, a problem
lies in the harvesting of undisturbed intact plaque samples from human volunteers
and the viewing of the biofilms in their natural state. In this study, we used an
in situ device for the in vivo generation of intact dental plaque biofilms on
natural tooth surfaces in human subjects. Two devices were placed in the mouths
of each of eight healthy volunteers and left to generate biofilm for 4 days.
Immediately upon removal from the mouth, the intact, undisturbed biofilms were
imaged by the non-invasive technique of confocal microscopy in both reflected
light and fluorescence mode. Depth measurements indicated that the plaque formed
in the devices was thicker round the edges at the enamel/nylon junction (range =
75-220 microm) than in the center of the devices (range = 35-215 microm). The
reflected-light confocal images showed a heterogeneous structure in all of the
plaque biofilms examined; channels and voids were clearly visible. This is in
contrast to images generated previously by electron microscopy, suggesting a more
compact structure. Staining of the biofilms with fluorescein in conjunction with
fluorescence imaging suggested that the voids were fluid-filled. This more open
architecture is consistent with recent models of biofilm structure from other
habitats and has important implications for the delivery of therapeutics to
desired targets within the plaque.
PMID- 10690657
TI - Electron microscopy, micro-analysis, and X-ray diffraction characterization of
the mineral-like tissue deposited by human cementum tumor-derived cells.
AB - The nature and characteristics of the mineralized-like tissue deposited by
cementoblasts are not well-known due to the difficulties in obtaining and
culturing cells representing the cementum phenotype. We hypothesized that a
putative cementoblastic cell line derived from a human cementoblastoma could
serve as a suitable model to study the physical, chemical, and morphological
features of the cementum-like tissue deposited in vitro. The cementoblastoma cell
line was studied by transmission electron, high resolution, scanning, and atomic
force microscopy and compared with human cellular cementum, human osteoblasts,
and human alveolar bone. The analyses of the crystals and mineral-like tissue in
the cell line were performed by x-ray diffraction microscopy and energy
dispersive x-ray micro-analysis. TEM examination of cementoblastoma cells
revealed the presence of electron-dense intracellular vesicles surrounded by a
membrane that contained filaments and needle-like structures. The diffraction
patterns obtained from the intracellular material and human cellular cementum
were similar, with D-spacings of 3.36 and 2.8, consistent with those of
hydroxyapatite (3.440 and 2.814). The composition of the mineral-like tissue had
a Ca/P ratio of 1.60 for cementoblastoma cells and 1.97 for human cellular
cementum. Na (5.29%) and Cl (1.47%) were present in the composition of
cementoblastoma cells. Human cellular cementum additionally contained Mg (4.95%).
Osteoblastic cells showed a Ca/P ratio of 1.6280. Na represented 4.52% and Cl
1.22% of its composition. Human alveolar bone had a Ca/P ratio value of 2.01. Na
(6.63%), Mg (2.10%), and Cl (0.84%) were also present. All samples examined
represented biological-type hydroxyapatite. Based on the compositional and
morphological features, these findings indicate that cementoblastoma-derived
cells express the human cellular cementum phenotype.
PMID- 10690658
TI - Quantification of periapical bone destruction in mice by micro-computed
tomography.
AB - Bacterial infections of the dental pulp result in tissue destruction and
periapical bone resorption. The availability of genetically engineered mouse
strains is a major advantage in the use of this model system for studies of
periapical pathogenesis. The main limitation of the mouse model is its small
size, and the necessity for laborious histologic analyses to quantify periapical
bone destruction. In the present study, we evaluated the use of a new technology,
high-resolution micro-computed tomography (micro-CT), for the rapid and non
invasive quantification of periapical bone destruction. Periapical lesions were
induced in the lower first molars of mice by exposing the pulp to the oral
environment. Mandibles were harvested on day 21 after pulp exposure, and were
subjected to micro-CT analysis, with 17-microm-thick radiographic sections.
Samples were then decalcified, embedded, and sectioned for histology. The cross
sectional area of periapical lesions was determined by image analysis of
corresponding micro-CT and histologic sections. The results showed a highly
significant correlation between micro-CT and histology (p < 0.0001), with mean
differences of 4. 1% (range, 0.9 to 7.2%) between the two methods. The mean error
associated with image analysis was 4.9% for images obtained by both micro-CT and
histology. The variability of replicate (n = 5) independent micro-CT
determinations was 3.4%, less than that associated with the image analysis error.
These results demonstrate that micro-CT imaging is a rapid, reproducible, and non
invasive method, that gives results that are closely comparable with those
obtained by histology. Micro-CT appears to have utility for the accurate
quantification of changes in bone architecture in small biological specimens.
PMID- 10690659
TI - Nominal shear or fracture mechanics in the assessment of composite-dentin
adhesion?
AB - This study addresses the anticipated problem of discriminating among high
performing dentin adhesives. The simplicity of the nominal shear bond test,
despite being heavily criticized, has made it a routine procedure for the
determination of bonding efficacy. A fracture mechanics approach has been
suggested as a better assessment of bonding efficacy (Versluis et al., 1997).
However, experimental complexity is a major limitation. It is hypothesized that a
new, simplified interfacial fracture toughness test (Lin, 1994) will evaluate
bonding agents differently if compared with the traditional shear bond test.
Therefore, the objective of this study was to compare the performances of six
dentin bonding agents subjected to the interfacial fracture toughness test
(critical plane strain energy release rate) or to the nominal shear bond test
(shear bond strength). Their performances were also characterized by scanning
electron micrography of the fracture surfaces for evidence of dentin cohesive
failure. Statistical analyses showed only marginal differences between these
determinants of the two tests. However, when the analysis was applied only to the
materials that had 100% frequency of dentin cohesive failure in shear testing,
which also had high bonding efficacy, the difference in adhesive strengths
between the two tests became significant. The reliability of the nominal shear
test is questioned when dentin cohesive failure occurs, which usually is
associated with high bonding efficacy. Since it is expected that bonding efficacy
will increase further, the interfacial fracture toughness test is the preferred
methodology to distinguish among high-performing dentin adhesives.
PMID- 10690660
TI - Acute-phase inflammatory response to periodontal disease in the US population.
AB - Moderate elevation of serum C-reactive protein (CRP) is a risk factor for
cardiovascular disease among apparently healthy individuals, although factors
that create this inflammatory response in the absence of systemic illness have
not been clarified. This study aimed to: (1) evaluate associations among
periodontal disease, established risk factors for elevated CRP, and CRP levels
within the US population; and (2) determine whether total tooth loss is
associated with reduced CRP. Data were obtained from the third National Health
and Nutrition Examination Survey. A random sample of the US population was
interviewed in their homes and examined at mobile examination centers. CRP was
quantified from peripheral blood samples and analyzed as a continuous variable
and as the prevalence of elevated CRP (> or = 10 mg/L). Some 12,949 people aged
18+ years who had periodontal examinations and an additional 1,817 edentulous
people aged 18+ years were included in the analysis. Dentate people with
extensive periodontal disease (> 10% of sites with periodontal pockets 4+ mm) had
an increase of approximately one-third in mean CRP and a doubling in prevalence
of elevated CRP compared with periodontally healthy people. Raised CRP levels
among people with extensive periodontal disease persisted in multivariate
analyses (P < 0.01), with established risk factors for elevated CRP (diabetes,
arthritis, emphysema, smoking, and anti-inflammatory medications) and
sociodemographic factors controlled for. However, CRP levels were similarly
raised in edentulous people. Furthermore, the established risk factors for
elevated CRP modified relationships between oral status and CRP levels.
Periodontal disease and edentulism were associated with systemic inflammatory
response in the US population, most notably among people who had no established
risk factors for elevated CRP.
PMID- 10690662
TI - A controlled study of the morphometric changes in the primary dentition of pre
term, very-low-birthweight children.
AB - The aim of the present investigation was to compare the dimensions of the primary
incisors from pre-term children and full-term controls. One hundred and eleven
pre-term children, consisting of 86 very-low-birthweight (< 1,500 g), 25 low
birthweight (from 1,500 to 2,500 g), and 169 full-term, normal-birthweight (>
2,500 g) children, donated a total of 572 maxillary and mandibular primary
central and lateral incisors for study. The teeth were measured by means of a
digital micrometer. The results showed that there was a dose-response effect of
birthweight on tooth size. The very-low-birthweight teeth showed the smallest
dimensions, the normal-birthweight controls the largest, and the low-birthweight
teeth intermediate dimensions (p < 0.001). In the maxillary primary central and
lateral incisors, and the mandibular primary central incisors, very-low
birthweight teeth were from 6 to 11% smaller in both mesiodistal and faciolingual
dimensions compared with normal-birthweight teeth (p < 0.001). The largest
differences were observed in the maxillary lateral incisors, where mean decreases
of 0.58 +/- 0.45 mm in mesiodistal and 0.50 +/- 0.40 mm in faciolingual
dimensions (11% reduction in both measurements) were observed. In addition, in
the mandibular and maxillary lateral incisors of very-low-birthweight children,
the left-sided teeth were significantly smaller than those on the right side in
both mesiodistal and faciolingual dimensions (p < 0.03).
PMID- 10690661
TI - Composition of plaque and saliva following use of an alpha-tricalcium-phosphate
containing chewing gum and a subsequent sucrose challenge.
AB - Previous studies demonstrated that the chewing of a 2.5% (mass fraction) alpha
tricalcium-phosphate-fortified (alpha-TCP) experimental chewing gum released
sufficient calcium and phosphate to eliminate any fall in the tooth mineral
saturation of plaque fluid after a sucrose rinse (Vogel et al., 1998). In
contrast, the chewing of a conventional sugar-free gum did not eliminate this
decrease in saturation. The purpose of this study was to examine if the release
of ions from plaque calcium-phosphate pools induced by this gum could provide
protection during subsequent exposure to cariogenic conditions. Fourteen subjects
accumulated plaque for 48 hrs, fasted overnight, chewed a control or experimental
gum for 15 min, and subsequently rinsed 1 min with a mass fraction 10% sucrose
solution. Before gum chewing, and at 7 min and 15 min afterward, whole plaque,
plaque fluid, and salivary samples were obtained and analyzed by micro-analytical
techniques. Additional samples were collected and analyzed at 25 min (7 min after
the sucrose rinse). Although the results confirmed the deposition of large
amounts of calcium and phosphates in plaque seen in the previous study, only a
small increase was seen in plaque-fluid-free calcium and phosphate before sucrose
administration. This suggests that few of the mineral ions were mobilized under
non-cariogenic conditions. However, 7 min after the sucrose rinsing, an increase
in these concentrations was seen which, based on hydroxyapatite ion activity
product calculations, indicated a decrease in the driving force for
demineralization compared with that seen with the control gum. These results
suggest that the chewing of the experimental gum deposits a labile mineral
reservoir in plaque that can resist a subsequent cariogenic challenge.
PMID- 10690664
TI - The expression of MMP-8 in human odontoblasts and dental pulp cells is down
regulated by TGF-beta1.
AB - Recent findings show that matrix metalloproteinase-8 (MMP-8) is expressed, in
addition to neutrophils, by human chondrocytes, cultured fibroblasts, and
endothelial cells. We investigated the expression of MMP-8 in other human
mesenchyme-derived cells, odontoblasts, and pulp tissue. Odontoblasts and pulp
tissue were collected from extracted human teeth for MMP-8 mRNA analysis with
reverse-transcription/polymerase chain-reaction (RT-PCR) and Southern blot. The
expression, localization, and secretion of MMP-8 protein were studied with
Western blot, immunohistochemistry, and immunofluorometric assay. The effect of
TGF-beta1 (10 ng/mL) on the expression, secretion, and concentration of secreted
MMP-8 was studied by odontoblast and pulp tissue culture methods (Tjaderhane et
al., 1998a). RT-PCR demonstrated MMP-8 mRNA expression in native and cultured
odontoblasts and pulp tissue and cultured pulp fibroblasts, with a 522-bp
transcript comparable with that of bone marrow cells. The specificity of PCR was
confirmed with Southern blot. Western blot with MMP-8-specific antibody detected
65- and 50-kDa proteins in native samples, representing latent and active forms
of mesenchymal-type MMP-8, and in the conditioned odontoblast culture media, 50
kDa protein was observed. TGF-beta down-regulated the MMP-8 mRNA and
concentration of secreted protein in both cultures. Immunohistochemical staining
detected MMP-8 in odontoblasts. These findings indicate that mesenchyme-derived
cells of the dentin-pulp complex express, synthesize, and activate MMP-8, which
may, in concert with odontoblast-derived gelatinases, participate in organization
of dentin organic matrix prior to mineralization.
PMID- 10690663
TI - Localization of EMSP1 expression during tooth formation and cloning of mouse
cDNA.
AB - Enamel matrix serine proteinase 1 (EMSP1) is a proteolytic enzyme that has been
isolated from the developing enamel of pig teeth. Its apparent function is to
degrade the organic matrix in preparation for enamel maturation. The expression
of EMSP1 has never been investigated in another organism besides the pig, and
EMSP1 expression in the enamel organ has never been specifically demonstrated in
ameloblasts. Here we report the expression of recombinant pig EMSP 1 (rpEMSP 1),
the generation of rabbit polyclonal antibodies against rpEMSP1, the
characterization of the antibodies and EMSP1 expression by Western blot and
immunohistochemical analyses, the cloning and characterization of a full-length
cDNA encoding mouse EMSP1, and the localization of EMSP1 expression in
ameloblasts in mouse day 14 first and second molars by in situ hybridization. The
full-length mouse EMSP1 cDNA clone has 1,237 nucleotides, excluding the poly(A+)
tail, and encodes a preproprotein of 255 amino acids. Mouse EMSP1 shares 75%
amino acid identity with pig EMSP1 and has three potential N-linked glycosylation
sites, two of which are conserved in the pig homologue. Western blot analysis
shows that the polyclonal antibodies are specific for EMSP1 and do not cross
react with trypsin. Immunohistochemistry of pig incisors shows discrete staining
in the surface enamel at the earliest part of the maturation stage. In mouse
molars, in situ hybridization gives a distinct and specific signal in maturation
stage ameloblasts, and in the junctional epithelium following tooth eruption. We
conclude that EMSP1 is expressed by pig and mouse ameloblasts during the early
maturation stage of amelogenesis.
PMID- 10690665
TI - Regional differences of metabolism in human masseter muscle by two-dimensional
31P-chemical shift imaging.
AB - Many reports have demonstrated significant region-dependent differences in the
fiber-type composition of the human masseter muscle. Therefore, it is considered
that there is intramuscular heterogeneity of metabolic activity in the muscle.
The present study was carried out, with two-dimensional Chemical Shift Imaging,
to detect differences between the deep and superficial parts of the human
masseter muscle at rest. Masseter muscle from 11 volunteers, from 20 to 27 years
old, was examined, and characteristic spectra of the inorganic phosphate (Pi),
phosphocreatine (PCr), and alpha-, beta-, and gamma-adenosine triphosphate (ATP)
from each part of the muscles were obtained. In this study, the deep and
superficial parts of the masseter muscle were distinguished by the existence of
aponeurosis. The Pi/PCr, PCr/beta-ATP, and Pi/beta-ATP ratios as well as the pH
in the deep and superficial parts were calculated from the peak spectra. Compared
with the deep part, the Pi/PCr of the superficial part was lower (p < 0.05) and
the PCr/beta-ATP was higher (p < 0.01). The Pi/beta-ATP and pH showed no
significant differences between the two parts. The results indicate that the
superficial part of the masseter muscle contains more PCr than the deep part, and
this may be related to functional differences between these two parts. In future
examinations of the metabolic activity of the human masseter muscle, the deep and
superficial parts must be measured separately.
PMID- 10690666
TI - Effects of organic acid anions on growth, glycolysis, and intracellular pH of
oral streptococci.
AB - Oral streptococci produce large quantities of organic acids as the end-products
of carbohydrate fermentation. In an approach to determine if oral streptococci
exhibit differential sensitivities to organic acid anions, we determined the
effects of formate, lactate, and acetate on intracellular pH maintenance,
glycolysis, and growth of Streptococcus mutans and Streptococcus sanguis. Growth
was determined as maximum culture optical density in the presence of the organic
acid anions at pH 7.1, 6.7, 6.3, and 6.1, and the effects of the anions on
glycolytic activity and intracellular pH were determined at pH 7.0 and 5.0. At pH
7.1, the organic acid anions had little effect on growth of either species. At
the lower pH values, all of the anions reduced the maximum culture optical
density of both species in a pH- and concentration-dependent manner, with S.
sanguis being more sensitive to growth inhibition than S. mutans. The organic
acid anions had little or no effect on glycolytic activity of either species at
pH 7.0. However, all of the organic acid anions tested reduced glycolytic
activity at pH 5.0 in a concentration-dependent manner, with S. sanguis being
more sensitive than S. mutans. The inhibition of glycolysis could be related to
the pKa of the organic acid, with formate and lactate being more inhibitory than
acetate. The organic acid anions decreased the intracellular pH of S. mutans and
S. sanguis, glycolyzing at an extracellular pH of 5.0, such that the reduction in
glycolytic activity caused by the organic acid anions could be directly
attributed to the fall in intracellular pH. In conclusion, the production of
lactic acid in plaque would not only lower pH, thereby having a disadvantageous
effect on less aciduric oral streptococci, such as S. sanguis, but would also
increase their sensitivity to the effects of low pH, helping S. mutans to become
more dominant.
PMID- 10690667
TI - Is laparoscopy the gold standard for the diagnosis of endometriosis?
PMID- 10690668
TI - Leptin, the ob gene product, in female health and disease.
AB - Leptin is a recently discovered hormone which is involved in the regulation of
body weight. It provides a molecular basis for the lipostatic theory of the
regulation of energy balance. White adipose tissue is the main site of leptin
synthesis and there is some evidence of ob gene expression in brown fat. Leptin
seems to play a key role in the control of body fat stores by coordinated
regulation of feeding behaviour, metabolic rate, autonomic nervous system
regulation and body energy balance in rodents, primates and humans. Apart from
the function of leptin in the central nervous system on the regulation of energy
balance, it may well be one of the hormonal factors that signal the body's
readiness for sexual maturation and reproduction to the brain. During late
pregnancy and at birth when maternal fat stores have been developed leptin levels
are high. Leptin could then be a messenger molecule signaling the adequacy of the
fat stores for reproduction and maintenance of pregnancy. At later stages of
gestation leptin could signal the expansion of fat stores in order to prepare the
expectant mother for the energy requirements of full term gestation, labour and
lactation. This overview focuses on those topics of leptin research which are of
particular interest in reproductive medicine and gynecology.
PMID- 10690669
TI - Appendix perforation by an intrauterine contraceptive device.
AB - Perforation of the uterus by an intrauterine contraceptive device (IUD) is a
rare, and serious complication, occurring in 1/350 to 1/2500 insertions.
Perforation by IUDs can involve several neighboring organs such as the bladder
and rectosigmoid. We report two cases of IUD perforations involving the appendix,
both inserted during lactation. The first case is an asymptomatic patient in
early pregnancy and the second is a woman whose original presentation was chronic
lower abdominal pain. The presence of copper in the abdominal cavity can lead to
adhesion formation and subsequent abdominal pain, bowel obstruction or
infertility. Thus, we believe that when an IUD is located in the abdominal cavity
it should be removed even in an asymptomatic patient. In addition, these cases
might suggest postponing the use of this contraceptive method in lactating women.
PMID- 10690670
TI - Obstetric brachial plexus injury: risk factors related to recovery.
AB - OBJECTIVE: To investigate if multivariate risk calculation can discriminate those
infants who do not recover after an obstetric brachial plexus injury (OBPI).
STUDY DESIGN: All liveborn infants without lethal congenital abnormalities from
1988 through 1996 with a gestational age > or =30 weeks were included. Outcome
variables were all OBPI and non-recovered OBPI. Risk calculation was performed by
univariate analysis for all infants and by multivariate logistic analysis for all
singleton infants delivered vaginally in cephalic presentation. RESULTS: A total
of 62 of 13 366 liveborn infants sustained an OBPI (0.46%). Seventeen (27%) did
not recover completely. Birth weight, female sex, second stage >60 min, diabetes,
multiparity, maternal age and non-Caucasian origin were important risk factors
for non-recovered OBPI. A model without birth weight, which can not be measured
accurately antepartum, is considerably less effective. Risk factors for all OBPI
and for non-recovered OBPI were similar. CONCLUSION: A predictive multivariate
model is of limited value due to the low incidence of non-recovered OBPI.
However, it may be useful to discriminate individual cases with exceptional risk.
PMID- 10690671
TI - Preliminary experience with twenty perineal repairs using Indermil tissue
adhesive.
AB - OBJECTIVE: To assess the use of Indermil tissue adhesive for perineal repair.
SETTING: Leeds General Infirmary, a teaching hospital with 4500 deliveries
annually. METHOD: Over a period of five months, 20 women who sustained either a
second degree tear or who had an episiotomy at vaginal delivery had their
perineal skin repaired with Indermil tissue adhesive. They were followed up prior
to discharge and then by telephone once discharged. RESULTS: Ten repairs followed
normal vaginal deliveries, six were after ventouse deliveries, three after
midcavity forceps delivery and one after a rotational forceps delivery. Three
women noticed a burning sensation during application of adhesive. At follow up,
13 women were completely without problems, two complained of a sharp sensation
from excess adhesive, one had silver nitrate applied at the six week check, two
had small defects in the skin which healed well and in two women the skin edges
broke down completely but did not need resuturing. CONCLUSION: Indermil tissue
adhesive appears to be a safe and effective method of skin closure for
episiotomies and second degree tears. The skin closure is quick and painless.
PMID- 10690672
TI - Diclofenac in the treatment of pain after caesarean delivery. An opioid-saving
strategy.
AB - OBJECTIVE: Pain relief of good quality after caesarean section (CS) results in
early mobilization and good early mother-child interaction. Patient-controlled
analgesia (PCA), with systemic opioids, gives a very high level of patient
satisfaction. However, opioids have well documented side-effects i.e. sedation,
nausea and respiratory depression. To minimize the risk of such negative effects
we studied how far the required dose of opioid could be decreased with a
multimodal strategy adding diclofenac. STUDY DESIGN: In a randomized double-blind
study, 50 parturients scheduled for elective CS under spinal anaesthesia,
received rectally either diclofenac (Suppositorium diclofenac) 50 mgx3 or placebo
1x3 during the first 24 h postoperatively. All patients had PCA with the
possibility of self-administered doses of ketobemidone 1 mg/6 min. RESULTS: In
the group receiving diclofenac rectally the consumption of ketobemidone was
reduced with 39% compared to the placebo group. CONCLUSION: A multimodal
analgetic strategy with the addition of 150 mg diclofenac during the first 24 h
after CS reduces the need for opioids significantly with maintained or improved
analgetic effect. This is expected to reduce the risk of negative side-effects of
systemic opioids.
PMID- 10690673
TI - Maternal neonatal outcome in quadruplet and quintuplet versus triplet gestations.
AB - OBJECTIVE: Examination and comparison of the natural histories of triplet versus
quadruplet and quintuplet gestations. STUDY DESIGN: A retrospective study of
sixty-four multifetal pregnancies (fifty-two sets of triplets, nine sets of
quadruplets and three sets of quintuplets) cared for during past 12 years in our
department. Quintuplets and quadruplets were compared with triplet pregnancies
according to gestational age, birthweight, pregnancy complications and perinatal
outcome. Student's t-test, Fisher exact test and chi2 test were used for
statistical analysis, considering P value of <0.05 as statistically significant.
RESULTS: Although mean gestational age at delivery between triplets and higher
order gestations was not significantly different, birthweight of quadruplets and
quintuplets was significantly lower. Pregnancy complications, including
intrauterine growth retardation, were equally distributed between the groups.
Early neonatal and perinatal mortality were significantly higher in quadruplets
and quintuplets than in triplets. Surprisingly, survival of growth retarded
fetuses was better than survival of their eutrophic counterparts. The spontaneous
loss rate was 11.5% for entire triplet gestation and 16.7% for quadru- and
quintuplet pregnancies. CONCLUSIONS: As the spontaneous loss rate of triplets and
higher order pregnancies observed in our study is quite similar to pregnancy loss
rate caused by multifetal pregnancy reduction, conservative management of
multifetal pregnancies in specialised tertiary centers seems to be a prudent
solution.
PMID- 10690674
TI - Mature cystic teratomas of the ovary: case series from one institution over 34
years.
AB - OBJECTIVE: To evaluate bilaterality, complications and malignant changes of
mature cystic teratomas of the ovary. STUDY DESIGN: Retrospective study of 501
patients operated at Hacettepe University Hospital between the years of 1964 and
1998. RESULTS: The median age was 35 years (range 13-76). One hundred and six
cases (21.1%) were asymptomatic. The mean tumor diameter was 7.0+/-4.5 cm. The
decision for cystectomy or oophorectomy was related with the patient age,
gravidity and parity. The bilaterality rate when both ovaries were evaluated
histopathologically was 13.2% (44/331). Total complication rate was 10.7%,
torsion being the most frequent (4.9%). The rate of malignant transformation was
1.4%. CONCLUSION: Ovarian mature cystic teratomas are common tumors especially
during the reproductive period with low rates of covert bilaterality,
complications and malignant transformation. The treatment should be directed on
the basis of age, fertility desire or presence of another pelvic pathology rather
than the size or bilaterality.
PMID- 10690675
TI - Role of appendectomy in predicting lymph node metastases in patients with ovarian
cancer.
AB - OBJECTIVE: The aim of this study was to assess the diagnostic accuracy of
appendectomy in predicting lymph node metastases in women undergoing
cytoreductive procedures for ovarian cancer. STUDY DESIGN: In 127 consecutive
patients with ovarian carcinoma appendectomy was performed in 30 patients over a
period of 5 years. Eight of them were found to have metastases to the appendix.
Pelvic and paraaortic lymphadenectomy was performed in 34 patients, in 24 of them
the appendix was removed during primary surgery. RESULTS: Among 19 patients
without metastases to the appendix the lymph nodes were positive in five cases
(26.3%) and among five patients with metastases to the appendix the lymph nodes
were positive in four cases (80.0%), which is not a significant difference.
Evaluation of the appendiceal metastases as a predictor of lymph node metastases
in patients with ovarian cancer gives a sensitivity of 44%, a specificity of 93%,
a positive predictive value of 80%, a negative predictive value of 74% and an
accuracy of 75%. CONCLUSION: The possibility of predicting retroperitoneal lymph
node metastases in ovarian cancer on the basis of histological examination of the
appendix is limited.
PMID- 10690676
TI - Inhibitory G protein alpha subunit (Gi alpha) expression and localization during
human trophoblast differentiation.
AB - OBJECTIVE: Cyclic adenosine monophosphate (cAMP) participates in the regulation
of processes associated with trophoblast syncytialization. As guanosine
triphosphate (GTP)-binding regulatory proteins (G-proteins) modulate adenylate
cyclase activity, the present study investigated the expression and regulation of
the alpha subunit of inhibitory G protein (Gi alpha) during human trophoblast
differentiation in vitro. STUDY DESIGN: Protein levels and the immunolocalization
of the protein at a subcellular-level were assessed. RESULTS: Expression of Gi
alpha protein decreased during syncytialization. Moreover, Gi alpha transmigrated
from a predominantly cell membrane-associated to a predominantly perinuclear
location during the process. CONCLUSION: These results suggest that Gi alpha is
regulated and may be implicated in cAMP-dependent events during the terminal
differentiation of human trophoblasts.
PMID- 10690677
TI - Two month glucocorticoid treatment increases estradiol-induced stromal and
myometrial cell proliferation in the uterus of ovariectomized rats.
AB - The present work was undertaken to examine the effect of 2 month glucocorticoid
treatment on estradiol-induced proliferation in the uterus. Ovariectomized rats
were treated with long-acting triamcinolone acetonide or saline for 60 days
followed by a single injection of estradiol dipropionate or vehicle.
Proliferation in the uterus was estimated by the mitotic index, bromodeoxyuridine
labelling index and proliferating cells nuclear antigen-labelling index 24, 36
and 48 h after the injection of estradiol or vehicle. Two month glucocorticoid
treatment resulted in an initial decrease in all the parameters for luminal and
glandular epithelia followed by an increase to 48 h after estradiol injection,
and in a large increase in all proliferative parameters for stromal and
myometrial cells at all periods of observation, compared with control rats
untreated with glucocorticoid. The 2 month glucocorticoid treatment protocol had
no significant effect on the parameters without estradiol administration.
Analysis of proliferation for myometrial cells was also performed after 1 month
treatment with glucocorticoid followed by estradiol or saline. Results showed no
significant influence of 1 month treatment with glucocorticoid on myometrial
cells.
PMID- 10690678
TI - Significance of chromosomal aberrations for the unsuccessful procedures of
assisted reproduction.
AB - Lymphocyte cultures from patients who had previously undergone at least three
unsuccessful procedures of assisted reproduction were analysed for cytogenetic
abnormalities. A total of 12,657 metaphases from 33 individuals (15 patients and
18 healthy controls with two normal offsprings) were studied. A significantly
higher incidence (P<0.001) of chromosome aberrations was found in the patients
(6.79+/-0.68%; x+/-SD) as compared to the controls (1.72+/-0.3%; P<0.001).
Chromosomal breakages, particularly at the centromere region, were also observed
with significantly increased frequency in the patients than in the controls
(6.18+/-0.65 vs. 1.42+/-0.27%, respectively; P<0.001). It is possible that the
high rate of centromere breakages in the ART patients (3.18+/-0.47 vs. 0.26+/
0.12%, P<0.001) may predispose to meiotic chromosomal abnormalities. A single
cell aberration was demonstrated in 0.61+/-0.21% of ART patients' lymphocytes
versus 0.3+/-0.12% in the controls (P<0.01). Structural rearrangements and
chromosomal breaks predominantly affected the bands containing genes for the
immune response and the cell cycle. Mosaic karyotypes were found in six patients.
One of them had a karyotype 46,XX/46,XX,r(14) and the others had sex chromosomal
mosaicisms. The prenatal diagnosis could be essential in these cases. It is
concluded that chromosomal aberrations could play a role in the repeated failure
of ART procedures.
PMID- 10690679
TI - EPH-gestosis (pre-eclampsia)-induced decrease of gelatinase activity may promote
an accumulation of collagen in the umbilical cord artery.
AB - It was found in our previous paper that edema, proteinuria, hypertension (EPH)
gestosis-associated accumulation of collagen in the umbilical cord artery (UCA)
is a result of increased biosynthesis and decreased degradation of this protein.
It is known that the activity of collagenolytic enzymes is a main factor
regulating collagen degradation rate in various tissues. For this reason it was
decided to evaluate the effect of EPH-gestosis on the activity of proteolytic
enzymes which may be involved in collagen degradation in the UCA wall.
Proteolytic activity against bovine serum albumin, reconstituted collagen fibres
and gelatin were evaluated. Latent forms of proteolytic enzymes were activated by
the action of trypsin, p-chloromercuric benzoate (PCMB) and p-aminophenylmercuric
acetate (APMA). A low activity of gelatinase (type IV collagenase) was detected
in the extracts from the wall of the umbilical cord artery. This enzyme increased
its activity several times after the action of trypsin, PCMB and APMA. EPH
gestosis results in a distinct reduction in gelatinase activity. Despite the
action of activating agents the gelatinase from EPH-gestosis UCAs was
considerably lower in comparison to control UCAs. It can be concluded that
gelatinase of the umbilical cord artery forms an inactive complex with a tissue
inhibitor of metalloproteinases. Such a complex dissociates under the action of
trypsin, PCMB or APMA or sodium dodecyl sulphate. The decrease of gelatinolytic
activity in the umbilical cord artery may be a factor that reduces the breakdown
of collagen in the arterial wall and promotes an accumulation of this protein.
The accumulation of collagen with simultaneous reduction in elastin content in
the UCA may be the factors which reduce the elasticity of arterial wall and
decrease the blood flow in the fetus of woman with EPH-gestosis.
PMID- 10690680
TI - Treatment outcome in women with a single ovary versus patients with two ovaries
undergoing in vitro fertilization and embryo transfer (IVF/ET).
AB - OBJECTIVE: To compare ovarian response and pregnancy rate between women with one
and two ovaries undergoing in vitro fertilization and embryo transfer (IVF/ET).
STUDY DESIGN: 20 IVF/ET treatment cycles in ten women with a single ovary were
compared with 60 IVF/ET cycles in 47 women with two ovaries. Both groups were
matched for age and treated for mechanical infertility. In both groups treatment
protocol included gonadotropin releasing hormone/human menopausal
gonadotropin/human chorionic gonadotropin (GnRH/hMG/hCG). RESULTS: Effective
daily dose of gonadotropins (3.7+/-0.7 vs. 3.6+/-1.0), mean 17beta-estradiol
levels on day of hCG administration (1136+/-467 vs. 1343+/-776), number of
retrieved oocytes (6.4+/-3.7 vs. 8.3+/-4.2) and number of embryos per transfer
(3.0+/-0.7 vs 2.9+/-1.2) were not statistically different between the groups. A
significantly higher pregnancy rate was observed among women with one ovary
(52.9%) as compared with those with two ovaries (20.8%), (P=0.015). Multivariate
logistic regression analysis demonstrated an odds ratio of 5.73 for patients with
a single ovary. CONCLUSION: Treatment outcome in patients with a single ovary
undergoing IVF/ET is comparable to those with two ovaries. The unexpected
significantly higher pregnancy rate observed among these patients need to be
further evaluated.
PMID- 10690681
TI - The Mirror syndrome.
AB - This is a case report illustrating a patient who developed pre-eclampsia with non
immunological hydrops fetalis associated with fetal tachycardia. It illustrates
how successful treatment of a fetal disorder can lead to resolution of the
maternal disorder.
PMID- 10690682
TI - A case report of acute pelvic thrombophlebitis missed by magnetic resonance
imaging of the pelvic veins.
AB - A 29-year-old woman presented post-natally with pulmonary hypertension.
Peripheral venous thrombosis was not detected by duplex ultrasound or
conventional MRI. Despite anticoagulation, the patient arrested. Autopsy revealed
right iliac vein thrombosis. The ability of conventional MRI to detect acute
pelvic thrombophlebitis depends on obtaining appropriate views.
PMID- 10690683
TI - Perinatal outcome in adolescent pregnancies: a case-control study from a Turkish
university hospital.
AB - OBJECTIVE: To determine whether adolescent pregnancy is associated with increased
risk for adverse pregnancy outcome. STUDY DESIGN: Retrospective case-control
study which enrolled 1460 singleton adolescent pregnancies and 2980 controls,
delivered at Hacettepe University Hospital between January 1990 and January 1998.
RESULTS: Significantly higher rate of perinatal and severe perinatal
complications were noted in adolescents. The presence of historical risks,
multiparity, young age and lack of prenatal care were significant predictors of
these complications. Exclusion of them except for age, revealed comparable
perinatal and severe perinatal complications in both groups. CONCLUSION:
Adolescent women who receive adequate prenatal care are at no greater risk of an
adverse obstetric outcome than adult women of a similar sociodemographic
background.
PMID- 10690684
TI - Borderline form of empty follicle syndrome: is it really an entity?
AB - We report two patients who were administered erroneously 1000 IU HCG instead of
10,000 IU for ovulation triggering in an assisted reproductive technology (ART)
cycle. In one case no oocyte was retrieved from eight mature follicles after
several washing attempts and retrieval day serum beta-HCG level was 21 mIU/ml. As
there was no follicle in the other ovary we did not try a rescue protocol. In the
other case two immature and one mature oocytes were retrieved from 15 mature
follicles located in both ovaries. Retrieval day serum beta-HCG level was 12
mIU/ml. ICSI was performed in one mature and two in vitro maturated oocytes and
the embryo transfer that was done 72 h after the retrieval yielded a healthy
singleton pregnancy. Our experience shows that a borderline form of EFS may be an
entity and it may be possible to see the formation of periovulatory events and
even to obtain a pregnancy in an ART cycle where the ovulation was triggered by
1000 IU HCG.
PMID- 10690685
TI - Epileptogenic activity of folic acid.
PMID- 10690686
TI - Anticoagulation of older patients.
PMID- 10690687
TI - Adverse drug reactions.
PMID- 10690688
TI - What's the use of cranberry juice?
PMID- 10690689
TI - Pacemaker syndrome in older people.
PMID- 10690690
TI - Beta-blocker use in elderly patients with coronary heart disease.
PMID- 10690691
TI - Non-drug strategies to resolve psycho-social difficulties after stroke.
PMID- 10690692
TI - A comparison of a low-dose warfarin induction regimen with the modified Fennerty
regimen in elderly inpatients.
AB - OBJECTIVES: To compare a new low-dose warfarin induction regimen with the
Fennerty regimen in elderly inpatients. DESIGN: Age-stratified, randomized
prospective study. SUBJECTS: 120 age-stratified elderly inpatients.
INTERVENTIONS: Each patient was randomized to either the new induction regimen or
to a modified Fennerty regimen. MAIN OUTCOMES MEASURES: Days to therapeutic
International Normalized Ratio (INR >2); days in the therapeutic range (INR 2-3)
during induction; number of patients with INR >4.5; ability of day 4 INR to
predict day 8 warfarin dose. RESULTS: The mean time to therapeutic INR was longer
for the new induction regimen than modified Fennerty regimen in patients aged 65
75 years [4.6 (mean) +/- 1.6 (SD) days vs 3.8 +/- 0.8 days; P = 0.03] and in
patients aged >75 years (4.5 +/- 1.4 days vs 3.5 +/- 0.7 days; P = 0.003).
Patients spent more time in the therapeutic INR range with the new induction
regimen [3.0 +/- 1.3 days vs 2.7 +/- 1.3 days (P = 0.03) for those aged 65-75
years and 2.9 +/- 1.1 days vs 2.4 +/- 1.3 days (P = 0.04 for those aged >75
years]. Fewer patients using the new regimen had INRs >4.5 in the first 8 days [1
(3%) vs 6 (20%) for 65-75 years (P < 0.05) and 1 (3%) vs 11 (37%) for >75 years
(P < 0.01)]. The ability to predict the maintenance dose to within 1 mg was 55%
for both regimens. CONCLUSION: The low-dose regimen has important clinical
advantages over the Fennerty regimen for anticoagulating elderly inpatients.
PMID- 10690693
TI - Contribution of adverse drug reactions to hospital admission of older patients.
AB - OBJECTIVE: To describe the severity of adverse drug reactions as a factor in
hospital admission of older patients, and to identify risk indicators for severe
adverse drug reactions in these patients. DESIGN: Observational cross-sectional
study. SETTING: Five wards in a university hospital in The Netherlands. SUBJECTS:
Patients aged 70 and over admitted to general medical wards. METHODS: Use of
statistical comparison and Kramer's algorithm. RESULTS: A severe adverse drug
reaction was present in 25 (24%) of 106 patients. Thirteen patients (12%; 95%
confidence interval 6.1-18.6%) were admitted probably because of an adverse drug
reaction. Risk indicators for a severe adverse drug reaction were a fall before
admission (odds ratio 51.3, P = 0.006), gastrointestinal bleeding or haematuria
(odds ratio 19.8, P < 0.001) and the use of three or more drugs (odds ratio 9.8,
P = 0.04). CONCLUSION: Adverse drug reactions are an important cause of hospital
admissions in older people. A fall before admission may indicate a severe adverse
drug reaction.
PMID- 10690694
TI - Measuring symptom change in patients with Parkinson's disease.
AB - BACKGROUND: The 39-item Parkinson's disease questionnaire (PDQ-39) is more
sensitive to functional change than other measures of health and disability. AIM:
To determine the ability of this scale to change over time and the concurrent
validity of some of its subscales. METHODS: We assessed a cohort of 67
Parkinson's patients for 18 months, using the PDQ-39, the GHQ-28 general health
questionnaire and the Office of Population and Census Surveys disability
instrument. RESULTS: The Office of Population and Census Surveys disability
instrument and GHQ-28 recorded no significant change, but the PDQ-39 showed
marked changes in levels of functioning. We also analysed changes on the PDQ-39
subscales as well as concurrent validity data for several subscales. This showed
concurrent validity with the Beck depression and anxiety inventories, the Barthel
index and the Royal Postgraduate Medical School severity scale. There was a high
level of concurrent validity for all comparisons except for the Barthel index.
CONCLUSION: The PDQ-39 is a sensitive tool for monitoring change in patients with
Parkinson's disease. It has high levels of concurrent validity with established
measures of mood and motor function.
PMID- 10690695
TI - The association between atrophic glossitis and protein-calorie malnutrition in
old age.
AB - AIM: To examine the relationship between atrophic glossitis (absence of papillae
in more than 50% of the tongue) and nutritional status. DESIGN: A randomized
population survey. SETTING: The medical department of Aker University Hospital,
and people living at home. PARTICIPANTS: 310 old people recently admitted to
hospital and 106 randomly selected elderly people at home. MEASURES: The presence
of atrophic glossitis and nutritional indices. RESULTS: Atrophic glossitis
occurred in 13.2% of men and 5.6% of women at home and in 26.6% of men and 37% of
women in hospital. The atrophic glossitis was related to reduced weight, body
mass index, triceps skinfold thickness, arm-muscle circumference, muscular
strength, activities of daily living and serum concentrations of cholesterol,
ascorbic acid, cholecalcidiol and B12, but not to levels of zinc or folate. In a
multiple logistic regression model, atrophic glossitis was related only to
cholesterol (P = 0.032), muscular strength (P = 0.018) and activities of daily
living (P = 0.03). CONCLUSION: Atrophic glossitis is common in elderly people and
is a marker for malnutrition and reduced muscle function.
PMID- 10690696
TI - Protein-energy oral supplementation in malnourished nursing-home residents. A
controlled trial.
AB - OBJECTIVES: To validate a nutritional intervention programme for elderly people
living in nursing homes. DESIGN: In a prospective, randomized, controlled study
of 88 residents, we determined nutritional status at day 0 and day 60 using a
record of dietary intake, anthropometry, hand-grip strength and mini-nutritional
assessment. Dietary intake, grip strength and body weight were also recorded at
day 30. We divided subjects into four groups according to their mini-nutritional
assessment score. Those with a score 24 received no oral supplementation. Those
at risk of malnutrition (with a score of 17-23.5) were randomized to oral
supplementation. Those with a score <17 received oral supplementation. We
recorded the amount of oral supplements consumed daily. RESULTS: Compliance with
oral supplementation was good, and daily intake averaged about 400 kcal. The
total energy intake on day 60 was significantly higher in both of the groups that
received supplements. Following supplementation, most subjects at risk of
malnutrition improved their mini-nutritional assessment score and increased their
weight (by 1.4 +/- 0.5 kg). Neither the mini-nutritional assessment score nor
weight improved in subjects at risk of malnutrition who did not receive
supplements. Supplementation in the malnourished group resulted in a mean mini
nutritional assessment score increase (from 13.9 +/- 2.6 to 17.1 +/- 3.9) and a
mean weight gain of 1.5 +/- 0.4 kg. CONCLUSION: Oral nutritional supplements are
well accepted and result in increased daily protein and energy intake, body
weight and nutritional status in most malnourished patients and in those at risk
of malnutrition.
PMID- 10690697
TI - Hip protectors improve falls self-efficacy.
AB - OBJECTIVES: To investigate the effect of use of external hip protectors on
subjects' fear of falling and falls self-efficacy (belief in their own ability to
avoid falling). DESIGN: Randomized controlled trial. SETTING: Aged-care health
services in Sydney, Australia. PARTICIPANTS: 131 women aged 75 years or older,
who had two or more falls or one fall requiring hospital admission in the
previous year and who live at home. Sixty-one subjects were in the intervention
group and 70 in the control group. INTERVENTION: Use of external hip protectors
and encouragement to use the protectors by an adherence nurse. MEASUREMENTS: At
the time of enrolment into a wider study examining the effect of hip protectors
on hip fractures, participants recruited at home completed an assessment of fear
of falling and falls efficacy as measured by the Falls Efficacy Scale and the
Modified Falls Efficacy Scale. At 4-month follow-up, these scales were
readministered by an observer who was not aware of the allocation of the
participant to intervention or control groups. RESULTS: Fear of falling and falls
self-efficacy, as measured by the Falls Efficacy and Modified Falls Efficacy
Scales, were similar at baseline in both groups. Fear of falling was present at
follow-up in 43% of subjects using hip protectors and 57% of the control group
(chi2 = 2.58, P = 0.11). Hip protector users had greater improvement in falls
self-efficacy at follow-up as measured by the Falls Efficacy Scale (t = 2.44, P =
0.016) and the Modified Falls Efficacy Scale (t = 2.08, P = 0.039). CONCLUSION:
Hip protectors improve falls self-efficacy. As users of hip protectors feel more
confident that they can complete tasks safely, they may become more physically
active and require less assistance with activities of daily living.
PMID- 10690698
TI - The Dutch pressure sore assessment score or the Norton scale for identifying at
risk nursing home patients?
AB - OBJECTIVE: To investigate the usefulness of a Dutch pressure sore risk assessment
scale--the Centraal Begeleidingsorgaan voor de Intercollegiale Toetsing (CBO;
National Organization for Quality Assurance in Hospitals) score--in the detection
of patients at risk of developing pressure sores after admission to a nursing
home. As the Norton score is the standard method of risk assessment, we also
investigated which score (Norton or CBO) has the stronger relationship to the
development of pressure sores. DESIGN: Longitudinal cohort design. PATIENTS: 220
nursing home patients, 80 men, 140 women, mean age 79 years (standard deviation
3). MEASURES: Admission assessments for the presence of pressure sores, CBO and
Norton scores, preventive measures and demographic characteristics. We made
observations every week for 4 weeks. MAIN OUTCOME MEASURE: Presence or absence of
pressure sores. MAIN RESULTS: 54 patients (25%) developed a pressure sore. A
significant, nonlinear relationship was found between the CBO score on admission
and the development of pressure ulcers for the first 2 weeks after admission.
Multiple logistic regression analysis showed that only mobility (odds ratio =
3.6, P = 0.0001) and mental state (odds ratio = 2.0, P = 0.03) showed a
significant relationship with the development of pressure ulcers. The CBO score
was no better in risk assessment than the Norton score. CONCLUSIONS: The CBO
score can be used for assessment of the risk of developing pressure ulcers in the
first 2 weeks after admission to a nursing home, but is no better than the Norton
score. Since the Norton score is easier to use, it is slightly preferable for use
in this setting. However, neither score is a good indicator of patients at risk.
Physicians should not depend solely on risk scores when prescribing preventive
measures.
PMID- 10690699
TI - Serum cholesterol concentrations and all-cause mortality in older people.
AB - OBJECTIVE: To study the impact of serum cholesterol concentrations on the total
risk of mortality in older people. DESIGN: Retrospective cohort study with a
follow-up of 8-10 years. SUBJECTS: A total of 989 subjects (367 men and 622
women) aged 65 and over, living in the Marshfield Epidemiologic Study Area at the
time of their first complete serum lipid assessment. METHODS: We calculated sex
specific mean levels of serum total cholesterol, low-density lipoprotein, high
density lipoprotein and triglycerides, and the ratio of total cholesterol to high
density lipoprotein, for subjects who died of all causes and for those who
survived to the end of follow-up, with adjustment for relevant covariates. We
obtained estimates of the risk factor-adjusted sex-specific relative risk for all
cause mortality with approximate quartiles of serum cholesterol concentrations by
proportional hazards regression models. We also evaluated the possible combined
effects of age, sex and cholesterol on all-cause mortality. RESULTS: A high level
of high-density lipoprotein was significantly associated with a low total risk of
mortality in older men. Conversely, an elevated ratio of total cholesterol to
high-density lipoprotein was directly related to an increased total risk of
mortality in older men. Age and high-density lipoprotein level had a significant
synergistic effect on all-cause mortality for the elderly men. We found little or
no association in women between all-cause mortality and any of the lipid measures
studied. CONCLUSIONS: An increased ratio of total cholesterol to high-density
lipoprotein appears to be associated with an increase in risk for all-cause
mortality in men aged 65 and over, while an elevated level of high-density
lipoprotein, considered alone, seems to be protective against mortality from all
causes in men aged 65-74 years, but this effect diminishes over the age of 75.
PMID- 10690700
TI - Reproductive longevity and increased life expectancy.
AB - BACKGROUND: Female life expectancy in developed countries has increased by 30
years in the twentieth century. AIM: To determine if there has been an increase
in reproductive longevity. METHODS: We analysed age-specific fertility data from
birth statistics for the USA, Canada, Japan, France, Sweden, the UK and
Australia. RESULTS: Since 1940, birth rates for women aged 35 and over have
declined. Among women aged 50 years and older, there has been no increase in
births. Fertility rates in 1990 were 0.0 to 0.044 per 1000 women, with total
numbers ranging from 0 to 60 births. CONCLUSION: The fertile years have not been
prolonged in the cohort of women whose life expectancy has increased so
dramatically this century. This suggests that reproductive senescence is tightly
controlled and not extended by factors that enhance female longevity. Other
physiological mechanisms may also be fixed within narrow age limits.
PMID- 10690701
TI - Do older hospital patients recognize adverse drug reactions?
AB - OBJECTIVE: To establish the relationship between subjective complaints of side
effects of drugs and the objective presence of adverse drug reactions in older
patients. DESIGN: Observational cross-sectional study. SETTING: Five medical
wards at the University Hospital Rotterdam Dijkzigt. SUBJECTS: Patients aged 70
and over admitted to the general medical wards over a 3-month period. METHODS:
Statistical comparison and Kramer's algorithm. RESULTS: Of 106 patients, 102 used
medication, and 93 of these were able to report whether they believed they were
experiencing drug side effects. Thirty-six [39% (95% confidence interval 28.8
48.6)] believed that they were experiencing side effects and the number of
diagnoses per patient and the proportion of patients with chronic obstructive
pulmonary disease was higher in these 36 'complainers' than in the group of the
'non-complainers'. We found a correct opinion (true positive and negative) about
the objective presence or absence of mild or severe adverse drug reactions in 79%
(95% confidence interval 70.2-86.8). Asking the patient about side effects of
drugs had a sensitivity of 0.70 and a specificity of 0.85 patients. The severe
adverse drug reactions in 21 patients were not recognized by 14 of them.
CONCLUSION: At hospital admission, older patients should be asked about drug side
effects because they are often correct in recognizing them. However, severe
adverse drug reactions are not easily recognized.
PMID- 10690702
TI - Myasthenia gravis and recurrent falls in an elderly patient.
AB - PRESENTATION: An elderly man had recurrent hospital admissions with falls.
OUTCOME: Acetylcholine receptor antibodies and single-fibre electromyogram were
useful in the diagnosis of myasthenia gravis. Treatment prevented further
hospital admissions.
PMID- 10690703
TI - Carotid sinus hypersensitivity--a modifiable risk factor for fractured neck of
femur.
PMID- 10690704
TI - Proximal femoral fracture while wearing correctly applied hip protectors.
PMID- 10690705
TI - Why do so few older people with aortic stenosis have valve replacement therapy?
PMID- 10690706
TI - Evaluation of an integrated care pathway for stroke unit rehabilitation.
PMID- 10690707
TI - Fetal biometry in different ethnic groups.
AB - OBJECTIVE: The aim of this study was to determine whether differences in
ultrasound-measured fetal biometry exist between pregnant woman of autochthonous
Belgian origin and migrant women from Morocco and Turkey. METHOD: A prospective
cross-sectional study was performed in which fetal biparietal diameter, head
circumference, abdominal circumference and femur length were measured in pregnant
women presenting between 18 and 40 weeks of gestation. Fetal weight was
calculated using the formulae by Shepard and Hadlock. Only uncomplicated
singleton pregnancies with a certain date of the last menstrual period, confirmed
by early ultrasound, were included. The father of the child had to be of the same
ethnic origin as the mother. Polynomial regression of the different measurements
was performed for women of autochthonous Belgian origin and for migrant women
from Morocco and from Turkey. RESULTS: Singleton fetuses numbering 524 were
examined, including 369 Belgian, 78 Moroccan and 77 Turkish. Polynomial
regression was performed for the three groups for the biparietal diameter, head
circumference, abdominal circumference, femur length and estimated fetal weight.
No significant difference between the three different ethnic groups could be
demonstrated for the biparietal diameter (P = 0.39). There was a significant
difference for the head circumference (P = 0.017), the abdominal circumference (P
= 0.0015), the femur length (P = 0.0014) and the estimated fetal weight for both
formulae (Shepard P = 0.047; Hadlock P = 0.0006). CONCLUSION: In this set of
cross-sectional data no significant difference for ultrasound-measured fetal
biparietal diameter between autochthonous Belgian women and migrant women from
Morocco and from Turkey could be demonstrated. Differences do exist for the head
circumference, the abdominal circumference, the femur length and the estimated
fetal weight. The use of adapted charts of fetal size for pregnant women of
Turkish or Moroccan origin should be considered.
PMID- 10690708
TI - Developmental changes of vitamin K epoxidase and reductase activities involved in
the vitamin K cycle in human liver.
AB - We examined the developmental changes in activities of vitamin K epoxidase, and
vitamin K-2,3-epoxide reductase and vitamin K reductase in the human autopsied
liver. The activity of epoxidase, which converts vitamin K hydroquinone to its
epoxide, showed a high value in the early prenatal period of 10-30 gestational
weeks but decreased rather rapidly in contrast with the reductase activities.
After birth, a significant decrease of the epoxidase activity was observed but no
such change was seen during the postnatal period. On the other hand, the
activities of vitamin K-2,3-epoxide reductase and vitamin K reductase, which
convert vitamin K-2,3-epoxide to its hydroquinone, showed a significantly low
value in the early prenatal period. The highest activity of vitamin K epoxidase
in the early prenatal period may be essential to the production of vitamin K
dependent ligands for growth factors expressed in the embryo.
PMID- 10690709
TI - Variation of the ganglioside compositions of human milk, cow's milk and infant
formulas.
AB - The ganglioside compositions of human milk, cow's milk and infant formulas were
compared. The results showed that there was a drastic change in the ganglioside
composition from the colostrum to later human milk, and that both the patterns
and contents of gangliosides in human milk, cow's milk and infant formulas
differed markedly. In human milk, the total lipid-bound sialic acid level was two
times higher than those in cow's milk and infant formulas. The major ganglioside
in the later human milk, GM3 (27.7%), was only a minor component in the
colostrum, cow's milk and infant formulas (3.3, 2.8 and 0.4-2.6%, respectively).
GD3 represented 49.0, 61.0 and 72.4-86.6%, respectively, of the colostrum, cow's
milk and infant formulas, compared to 31.8% of the later human milk gangliosides.
Another four gangliosides, which were assumed to be c-series gangliosides, were
detected in the colostrum and the later human milk. They represented 33-38% of
total lipid-bound sialic acid, and were tentatively designated as GX1, GX2, GX3
and GX4, respectively. However, only GX1 and GX2 were observed in cow's milk and
infant formulas. The variation of the gangliosides in human and cow's milk, and
infant formulas might have some biological significance regarding neonatal brain
development, allergies, infant growth and non-immunoglobulin prophylactic
activities against some bacterial toxins.
PMID- 10690710
TI - Visual-motor function of very low birth weight and full-term children at 3 1/2 to
4 years of age.
AB - Improvements in perinatal and neonatal management have not only led to a higher
survival rate of very low birth weight infants (VLBW; < or = 1,500 g or < 32
weeks gestational age), but also to a better outcome of these children. However
the percentage of VLBW children who need special education because of later
school problems remains high even in children considered neurologically normal
during infancy. We assessed 40 VLBW children and 83 healthy full-term children at
age 3 to 4 years by means of a simple and short test for visual-motor deficits.
The test included the copying and cutting-out of geometric shapes, the building
of models, the recognition of colours and the observation of the concentration
and cooperation during the test. All VLBW children had had a good perinatal
outcome and had been considered neurologically normal at one year of age. Most
VLBW children scored within 1 standard deviation (S.D.) of the test mean, but on
average the VLBW children scored significantly lower than the full-term infants
in the copying of figures, the cutting-out of geometric forms, the building of
models and in the overall concentration and cooperation during the test. Children
who attended a nursery school achieved significantly better test results. Girls
tended to have better results, but this was not statistically significant. Social
factors and age had a significantly greater impact on results than perinatal
factors. In summary, VLBW children scored significantly less in almost every test
item compared to their term peers. Our test battery could serve as a short
introductory test to screen for deficits in visual-motor skills, especially in
VLBW children.
PMID- 10690711
TI - Efficiency of left ventricular diastolic function increases in healthy full-term
infants during the first months of life. A prospective follow-up study.
AB - Postnatal changes in left ventricular diastolic filling and systolic cardiac
performance were studied monthly by serial echocardiographic measurements from
days 3-5 up to six months in 20 healthy full-term infants. The fractional
shortening area (FSA = (left ventricular end-diastolic area - end-systolic
area)/end-diastolic area) was assessed for systolic performance, and transmitral
pulsed-wave Doppler flow velocity patterns were analysed for diastolic function.
FSA remained stationary during the observation. After birth, left ventricular
peak early (E) and atrial (A) velocities and the respective integrals were lower
than at one month of age (47+/-5 vs. 63+/-6 cm/s and 44+/-6 vs. 57+/-5 cm/s and
3.33+/-0.40 vs. 4.05+/-0.53 cm and 2.74+/-0.40 vs. 3.18+/-0.53 cm; P < 0.05).
During the next five months, the early parameters (E velocity and E integral)
increased but the atrial indices (A velocity and A integral) did not change.
During the whole observation the E/A velocity ratio, the E/A integral ratio and
the early filling fraction (EFF) increased. The early filling deceleration time
was longer during the first month than later (87+/-10 vs. 72+/-13 ms; P < 0.05).
In conclusion, age-related changes were observed in the diastolic but not in the
systolic performance in healthy full-term infants during the first six months.
The most intensive changes took place in the early and atrial transmitral
parameters during the first month of life, suggesting an improvement in both left
ventricular relaxation and compliance. During the following five months, the
early mitral parameters increased but the atrial diastolic values remained
stable. These changes may mainly be determined by the improvement in left
ventricular relaxation.
PMID- 10690712
TI - Effect of epidermal growth factor on lung growth in experimental fetal pulmonary
hypoplasia.
AB - The purpose of this study was (1) to compare the expression of epithelial growth
factor receptor (EGFR) in the lung tissues of human fetuses with or without
pulmonary hypoplasia, and (2) to investigate the effects of EGF on lung growth in
experimental pulmonary hypoplasia in rabbits. Firstly, we investigated the
expression of EGFR in lung tissues of human fetuses with or without pulmonary
hypoplasia by immunohistochemistry. Secondly, the amniotic fluid was shunted into
the maternal abdominal cavity in a group of 12 fetal rabbits, another group (n =
12) received EGF injection (5 microg, i.p.) at day 25 of gestation. The third
group (n = 12) was only treated with EGF while littermates not operated on served
as the control group (n = 12). On day 29 of gestation, fetuses were delivered by
Cesarean section and the lungs removed. The body weight and wet lung and liver
weights were measured. As a measure of fetal lung growth, we determined the size
of lung acini, the number of terminal airspaces, and diameter of alveoli (n = 6,
each groups). We also measured the concentration of phosphatidylcholine (PC) and
the lecithin/sphingomyelin (L/S) ratio in lung lavage fluid at birth in some
fetuses (n = 6, each groups). In human fetuses with pulmonary hypoplasia, there
was a significant decrease in radial alveolar count and expression of EGFR
compared with fetuses without pulmonary hypoplasia. Amniotic shunt significantly
decreased fetal lung/body weight ratio compared with control. Injection of EGF in
the shunted group significantly increased lung/body weight ratio to the control
level. The concentration of PC and L/S ratio in lung fluid lavage from rabbit
fetuses with hypoplastic lungs was significantly higher than the other three
groups. Histopathological examination of fetuses with hypoplastic lungs treated
with EGF showed no significant change in the size of acini, number of terminal
airspaces or the diameter of alveoli compared with the control group. Our results
suggested that EGF was associated with lung growth and maturation of human lung
and that treatment of rabbit fetuses with hypoplastic lungs with EGF facilitated
lung growth and development.
PMID- 10690713
TI - Hepatic taurine, glycine and individual bile acids in early human fetus.
AB - OBJECTIVE: To examine 3alpha-hydroxy individual bile acid and the association
between taurine and taurine-conjugated bile acid in human fetal liver. METHODS:
Taurine, glycine and the individual bile acids in liver samples taken from 17
human fetuses whose abortion was induced from 12 to 23 weeks' gestation were
determined by high-performance liquid chromatography. RESULTS: The concentrations
of taurine, glycine and bile acids in early fetal life were not related to
gestational age. Hepatic taurine was statistically correlated with total taurine
conjugates (r = 0.798; P < 0.0001), but hepatic glycine was not correlated with
glycine-conjugates (r = -0.103; P > 0.05). Lithocholic acid was conjugated
exclusively with taurine. CONCLUSIONS: Our results supported that in human fetal
life there is a considerable bile acid pool in liver, and that taurine works
effectively on the bile acid metabolism depending on the hepatic taurine
concentration.
PMID- 10690714
TI - Conquering pain.
PMID- 10690715
TI - Microsurgical resection of brainstem, thalamic, and basal ganglia
angiographically occult vascular malformations.
AB - OBJECTIVE: To evaluate the clinical results for patients who underwent resection
of angiographically occult vascular malformations (AOVMs) of the brainstem,
thalamus, or basal ganglia, successfully resected after it exhibited rebleeding
and presented to a pial surface. METHODS: Between January 1990 and May 1998, 56
patients with 57 deep AOVMs underwent 63 operations, at Stanford University
Medical Center, to treat AOVMs of the brainstem (42 AOVMs), thalamus (5 AOVMs),
or basal ganglia (10 AOVMs). The surgical approach was suboccipital midline (27
operations), far lateral suboccipital (10 operations), transsylvian (9
operations), interhemispheric transcallosal or infracallosal (8 operations),
infratentorial supracerebellar (6 operations), or subtemporal (3 operations).
Four patients experienced recurrent bleeding from the same lesion after surgical
resection, requiring a second operation. One patient required a planned second
operation, using a different approach, to completely resect the lesion, and one
patient underwent two surgical procedures to resect two separate brainstem AOVMs.
One patient initially underwent exploration but not resection of her AOVM,
because it did not present to a pial or ependymal surface. The AOVM was
successfully resected after it exhibited rebleeding and presented to a pial
surface. RESULTS: The immediate outcomes after surgery were unchanged for 31
patients (55%), worsened for 16 (29%), and improved for 9 (16%). The long-term
outcomes were unchanged for 24 patients (43%), compared with their presenting
grade, worse for 3 (5%), and improved for 29 (52%). Patients who had undergone
previous radiotherapy or radiosurgery to treat these lesions experienced more
difficult postoperative courses, and radiation necrosis was observed for two
patients. CONCLUSION: AOVMs of the brainstem, thalamus, and basal ganglia can be
safely removed, with a long-term neurological morbidity rate of only 5% and a
complete lesion resection rate of 93% after the initial planned resection. The
use of cranial base surgical approaches and intraoperative electrophysiological
monitoring contributes to successful clinical outcomes.
PMID- 10690716
TI - Factors associated with intracranial hemorrhage in cases of cerebral
arteriovenous malformation.
AB - OBJECTIVE: The standard categorization of arteriovenous malformations (AVMs)
involves the Spetzler-Martin grading system, which uses a simple analysis of
size, location (superficial or deep), and the presence of deep or superficial
drainage. Hemodynamic risk factors are also thought to play important roles in
the pathogenesis of these lesions and to be associated with the intracranial
hemorrhage (ICH) rate. The actual hemodynamic factors for AVMs cannot be easily
measured, but angioarchitectural features can be assessed and used as surrogate
parameters. METHODS: The AVM angioarchitectural features for 662 patients were
analyzed, and their associations with ICH as a presenting sign were studied. A
cross-sectional analysis was used to qualify the strength of associations among
clinical features, angioarchitectural characteristics, and ICH before treatment.
RESULTS: The multivariate analysis indicated that arterial stenosis and arterial
ectasia were associated with lower ICH rates, whereas venous stenosis increased
the rate of ICH. The presence of angiogenesis modified the effects of arterial
and venous stenosis. Furthermore, the effect of venous stenosis depended on the
location of the nidus. The presented data do not support a direct positive
association between associated aneurysms and ICH. CONCLUSION: Certain
angiographic features seem to have prognostic potential with respect to the
occurrence of ICH among patients with AVMs. A discriminatory prognostic index is
proposed; its relevance must be proven in a future prospective study.
PMID- 10690717
TI - Ischemic events associated with unruptured intracranial aneurysms: multicenter
clinical study and review of the literature.
AB - OBJECTIVE: To determine the prevalence, clinical characteristics, and long-term
outcomes in cases involving transient ischemic attacks (TIAs) or ischemic strokes
secondary to embolization from unruptured intracranial aneurysms. METHODS: We
identified all available patients with intracranial aneurysms and ischemic
strokes in three university-affiliated hospitals, using either International
Classification of Diseases-9th Revision codes or local registries. Patients with
clinically or radiologically detected cerebral infarctions distal to intracranial
aneurysms, in the absence of other causes for the infarctions, were included. An
aneurysmal embolic source was considered highly probable by the primary
neurosurgeon/neurologist in all cases. Follow-up data for the patients were
acquired through reviews of clinical visits or telephone interviews. A review of
the literature was performed to identify characteristics of previously reported
patients. RESULTS: Ischemic strokes or TIAs attributable to embolization from the
aneurysmal sac were observed for 9 of 269 patients (3.3%) with unruptured
aneurysms. Of these nine patients, five were women and four were men (mean age,
62 yr; age range, 45-72 yr). Symptomatic aneurysms were located in the middle
cerebral artery (n = 4), internal carotid artery (n = 3), posterior cerebral
artery (n = 1), or vertebral artery (n = 1). The mean maximal diameter was 12.5
mm (range, 5-45 mm). Six patients underwent surgical treatment, of whom two
experienced postoperative cerebral infarctions referable to the distribution of
the artery harboring the aneurysm. Two patients were treated with aspirin, and
one patient received no treatment. The mean follow-up period was 38 months
(range, 1-60 mo). None of the patients experienced additional ischemic events
during the follow-up period. Among the 41 previously reported patients,
conservative treatment was used for 20 patients (mean follow-up period, 50.7 +/-
44.5 mo). Four of the 20 patients experienced recurrent TIAs, 1 patient
experienced worsening of symptoms, and 1 patient died during the follow-up
period. A total of 21 patients underwent surgical treatment (mean follow-up
period, 33.6 +/- 32.3 mo). Of these patients, only one experienced recurrent
TIAs. Two patients experienced postoperative seizures, and one patient died
during the follow-up period. All recurrent symptoms with either surgical or
conservative treatment were transient, and no patient experienced a major or
disabling stroke during the follow-up period. CONCLUSION: Ischemic events can
occur distal to both small and large unruptured intracranial aneurysms
(predominantly in the anterior circulation). The long-term risk of recurrent
ischemic events, particularly major or disabling strokes, seems to be low with
either surgical or conservative treatment.
PMID- 10690718
TI - Long-term outcomes for surgically resected craniopharyngiomas.
AB - OBJECTIVE: This retrospective study critically analyzed the long-term functional
outcomes and tumor recurrence rates for surgically treated craniopharyngiomas.
METHODS: This study used an outcome classification system that included
functioning vision, independent versus dependent living, Karnofsky Performance
Scale scores, academic levels, work status, and psychological status. Tumor
recurrence rates were analyzed with respect to the extent of surgical resection
and adjunctive radiotherapy. RESULTS: For 121 patients, with a mean follow-up
period of 10 years, the overall "good outcome" rate was 60.3%. Factors associated
with poor outcomes included lethargy at presentation, visual deterioration,
papilledema, tumor calcification, hydrocephalus, and tumor adhesiveness at
surgery. Gross total resection was associated with good outcomes (P = 0.017) and
decreased risk of recurrence (P = 0.024). Subtotal resection was associated with
increased risk of tumor recurrence (P = 0.0235). The highest risk of recurrence
was in the subtotal resection/no radiation group (P = 0.0001). There were no
differences in outcomes or recurrence rates between pediatric and adult patients.
There were also no differences in outcomes or recurrence rates between papillary
and adamantinous tumors. Approximately one-third of patients exhibited morbid
obesity, and permanent diabetes insipidus was observed for 25 patients.
CONCLUSION: A rigorous evaluation of outcomes for tumors such as
craniopharyngiomas must consider not only the extent of resection, as judged by
postoperative imaging, but also the long-term physical, intellectual, and
psychological functioning of the patients.
PMID- 10690719
TI - Using proton magnetic resonance spectroscopic imaging to predict in vivo the
response of recurrent malignant gliomas to tamoxifen chemotherapy.
AB - OBJECTIVE: Most patients with a malignant glioma spend considerable time on a
treatment protocol before their response (or nonresponse) to the therapy can be
determined. Because survival time in the absence of effective therapy is short,
the ability to predict the potential chemosensitivity of individual brain tumors
noninvasively would represent a significant advance in chemotherapy planning.
METHODS: Using proton magnetic resonance spectroscopic imaging (1H MRSI), we
studied 16 patients with a recurrent malignant glioma before and during treatment
with high-dose orally administered tamoxifen. We evaluated whether 1H MRSI data
could predict eventual therapeutic response to tamoxifen at the pretreatment and
early treatment stages. RESULTS: Seven patients responded to tamoxifen therapy
(three with glioblastomas multiforme; four with anaplastic astrocytomas), and
nine did not (six with glioblastomas multiforme; three with anaplastic
astrocytomas). Responders and nonresponders exhibited no differences in their
age, sex, tumor type, mean tumor volume, mean Karnofsky scale score, mean number
of weeks postradiotherapy, or mean amount of prior radiation exposure. Resonance
profiles across the five metabolites measured on 1H MRSI spectra (choline
containing compounds, creatine and phosphocreatine, N-acetyl groups, lactate, and
lipids) differed significantly between these two groups before and during
treatment. Furthermore, linear discriminant analyses based on patients' in vivo
biochemical information accurately predicted individual response to tamoxifen
both before and at very early treatment stages (2 and 4 wk). Similar analyses
based on patient sex, age, Karnofsky scale score, tumor type, and tumor volume
could not reliably predict the response to tamoxifen treatment at the same time
periods. CONCLUSION: It is possible to accurately predict the response of a tumor
to tamoxifen on the basis of noninvasively acquired in vivo biochemical
information. 1H MRSI has potential as a prognostic tool in the pharmacological
treatment of recurrent malignant gliomas.
PMID- 10690720
TI - A preliminary study of the prognostic value of proton magnetic resonance
spectroscopic imaging in gamma knife radiosurgery of recurrent malignant gliomas.
AB - OBJECTIVE: The goal of this study was to investigate the use of proton magnetic
resonance spectroscopic imaging as a prognostic indicator in gamma knife
radiosurgery of recurrent gliomas. METHODS: Thirty-six patients with recurrent
gliomas were studied with proton magnetic resonance spectroscopic imaging at the
time of radiosurgery, and with conventional magnetic resonance imaging
examinations at regular time intervals until the initiation of a new treatment
strategy. Patients were categorized on the basis of their initial spectroscopic
results, and their performance was assessed in terms of change in contrast
enhancing volume, time to further treatment, and survival. RESULTS: The trends in
the overall population were toward more extensive increase in the percent
contrast-enhancing volume, a decreased time to further treatment, and a reduced
survival time for patients with more extensive initial metabolic abnormalities.
Statistical analysis of the subpopulation of patients with glioblastoma
multiforme found a significant increase in relative contrast-enhancing volume (P
< 0.01, Wilcoxon signed-rank test), a decrease in time to further treatment (P <
0.01, log-rank test), and a reduction in survival time (P < 0.01, log-rank test)
for patients with regions containing tumor-suggestive spectra outside the gamma
knife target, compared with patients exhibiting spectral abnormalities restricted
to the gamma knife target. Further studies are needed to establish statistical
significance for patients with lower-grade lesions and to confirm the results
observed in this study. CONCLUSION: The pretreatment spectroscopic results
provided information that was predictive of outcome for this patient pool, both
in local control (change in contrast-enhancing volume) and global outcome (time
to further treatment and survival). This modality may have an important role in
improving the selection, planning, and treatment process for glioma patients.
PMID- 10690721
TI - In vivo proton magnetic resonance spectroscopy of central neurocytomas.
AB - OBJECTIVE: The authors report on the metabolic features of central neurocytomas
observed during in vivo single-voxel proton magnetic resonance spectroscopy.
METHODS: Volume-selective single-voxel proton magnetic resonance spectroscopy was
performed with a 1.5-T unit using a point-resolved spectroscopy sequence (TR/TE =
2000 ms/135 and 270 ms) to obtain spectra of a single 8-cc voxel. The subjects
were five patients in the Department of Neurosurgery of Seoul National University
Hospital whose central neurocytomas had been diagnosed histologically. The peak
intensities of compounds containing choline (Cho), N-acetylaspartate,
creatine/phosphocreatine, and lactate were analyzed. RESULTS: The ratios of Cho
to creatine/phosphocreatine and Cho to N-acetylaspartate were significantly
higher than ratios in normal brains. A lactate signal was present, and an
unidentified signal was also observed at 3.55 ppm, which might have been produced
by inositol or glycine. CONCLUSION: A combination of the signal at 3.55 ppm and a
prominent Cho peak seems to be a characteristic feature of central neurocytomas.
Volume-selective single-voxel proton magnetic resonance spectroscopy could
provide additional information to aid in diagnosing this condition.
PMID- 10690722
TI - The influence of hyperglycemia on neurological outcome in patients with severe
head injury.
AB - OBJECTIVE: Traumatic brain injury is associated with a stress response that
includes hyperglycemia, which has been shown to worsen neurological outcome
during cerebral ischemia and hypoxia. To better examine the relationship between
hyperglycemia and outcome after head injury, we studied the clinical course of
267 head-injured patients who were admitted for treatment in the neurosurgical
department of Asclepeion Hospital of Athens between January 1993 and November
1997. METHODS: We prospectively studied 267 patients with moderate or severe
craniocerebral injury (Glasgow Coma Scale scores, 3-12) who were treated
surgically for evacuation of an intracranial hematoma and/or placement of a
device for intracranial pressure monitoring under general anesthesia to determine
the relationship between serum glucose levels, severity of injury, and
neurological outcome. RESULTS: Patients with severe head injury had significantly
higher serum glucose levels than did those with moderate injury. Patients who
subsequently had an unfavorable outcome had significantly higher glucose levels
than did those with a better prognosis. Among the patients with more severe head
injury, a glucose level greater than 200 mg/dl was associated with a worse
outcome. In the same group of patients, a significant relationship was found
between postoperative glucose levels, pupillary reaction, and maximum
intracranial pressure during the first 24 hours. Multivariate analysis showed
that postoperative glucose levels were an independent predictor of outcome.
CONCLUSION: Early hyperglycemia is a frequent component of the stress response to
head injury, a significant indicator of its severity, and a reliable predictor of
outcome.
PMID- 10690723
TI - Outcome of unilateral and bilateral pallidotomy for Parkinson's disease: patient
assessment.
AB - OBJECTIVE: Pallidotomy has recently regained acceptance as a safe and effective
treatment for Parkinson's disease symptoms. The goal of this study was to obtain
the patients' perspective on their results after undergoing this procedure.
Special attention was focused on the potential complications and the respective
advantages and risks of unilateral versus bilateral pallidotomy. METHODS: Fifty
six patients were studied during a 2-year period; 44 completed the evaluation,
with a median follow-up of 7 months. Of these patients, 22 underwent unilateral
pallidotomy, and 17 had bilateral simultaneous pallidotomy. Five patients who
underwent staged bilateral pallidotomy were excluded from the statistical
analysis, because the number of patients was considered too small for analysis.
The procedures were performed with magnetic resonance imaging determination of
the target, combined with physiological confirmation, including microelectrode
recording. RESULTS: According to Visual Analog Scale scores, unilateral
pallidotomy significantly improved dyskinesias (P < 0.05) but no other symptoms.
Simultaneous bilateral pallidotomy improved slowness, rigidity, tremor, and
dyskinesias (P < 0.05) but worsened speech function (P < 0.05). According to the
patients' most frequently chosen answers to multiple-choice questions, unilateral
pallidotomy improved night sleep, muscle pain, freezing, overall "on," overall
"off," and the duration of "off periods," but it worsened the volume of the voice
and articulation, increased drooling, and reduced concentration. Bilateral
pallidotomy improved night sleep, muscle pain, freezing, overall "on," overall
"off," duration of "off periods," and the amount of medication taken, but it
increased drooling and worsened the volume of the voice, articulation, and
writing. Subjective visual disturbance was noted in 36 and 41% of patients who
underwent unilateral and simultaneous bilateral pallidotomy, respectively.
Globally, the result of the procedure was rated "good" or "excellent" by 64% of
the patients who underwent unilateral pallidotomy and by 76% of the patients who
underwent bilateral pallidotomy. An age less than 70 years was a positive
prognostic factor for the global outcome (P < 0.05), as were severe preoperative
dyskinesias (P < 0.05). CONCLUSION: This study confirms that, from a patient
standpoint, unilateral and simultaneous bilateral pallidotomy can reduce all the
key symptoms of Parkinson's disease (i.e., akinesia, tremor, and rigidity) and
the side effects of L-dopa treatment (i.e., dyskinesias). Preoperative severe
dyskinesias and younger age are positive prognostic factors for a successful
outcome. Simultaneous bilateral pallidotomy was more effective than unilateral
pallidotomy regarding tremor, rigidity, and dyskinesias, but it conferred a
higher risk of postoperative speech deterioration.
PMID- 10690724
TI - Recurrent trigeminal neuralgia attributable to veins after microvascular
decompression.
AB - OBJECTIVE: To demonstrate the cause of and optimal treatment for recurrent
trigeminal neuralgia (TN) in cases where veins were observed to be the offending
vessels during the initial microvascular decompression (MVD) procedure. METHODS:
An electronic search of patient records from 1988 to 1998 revealed that 393
patients were treated with MVD for TN caused by veins. The pain recurred in 122
patients (31.0%). Thirty-two (26.2%) of these patients underwent reoperations.
Clinical presentations, recurrence intervals, surgical findings, and clinical
outcomes were analyzed. RESULTS: Analysis of 32 consecutive cases of recurrent TN
initially attributable to veins revealed a female predominance (female/male =
26:5), with one female patient exhibiting bilateral TN caused by venous
compression. Patient ages ranged from 15 to 80 years, with a prevalence in the
seventh decade. The V2 distribution of the face was involved more frequently than
other divisions. For 24 patients (75%), recurrence occurred within 1 year after
the initial operation. At the time of the second MVD procedure, development of
new veins around the nerve root was observed in 28 cases (87.5%). After
successful subsequent MVD procedures, the pain was improved in 81.3% of the
cases. CONCLUSION: The recurrence rate for TN attributable to veins is high. If
pain recurs, it is likely to recur within 1 year after the initial operation. The
most common cause of recurrence is the development and regrowth of new veins.
Even fine new veins may cause pain recurrence; these veins may be located beneath
the felt near the root entry zone or distally, near Meckel's cave. Because of the
variable locations of vein recurrence, every effort must be made to identify
recollateralized veins. Given the high rate of pain relief after a second
operation, MVD remains the optimal treatment for the recurrence of TN
attributable to vein regrowth.
PMID- 10690725
TI - Percutaneous retrogasserian glycerol rhizolysis for treatment of chronic
intractable cluster headaches: long-term results.
AB - OBJECTIVE: To analyze the long-term effectiveness and safety of percutaneous
retrogasserian glycerol rhizolysis (PRGR) in the treatment of medically
refractive chronic cluster headache (CH). The current mainstay of surgical
intervention for these patients is percutaneous radiofrequency retrogasserian
rhizotomy (PRFR). However, when performed for V1 distribution pathology, PRFR can
lead to corneal anesthesia, which places the patient at risk for future visual
loss. It also increases the risk of facial dysesthesia. METHODS: In a
prospective, consecutive series, 18 patients with intractable CH were followed
for a mean of 5.2 years (range, 40-78 mo) after they had undergone PRGR,
performed using a standard technique. The significance of this technique as an
alternative to PRFR is that it should result in a lower rate of both corneal and
facial anesthesia and provide an acceptable degree of pain relief. RESULTS:
Fifteen patients (83%) obtained immediate pain relief after one or two
injections; the majority of them experienced relief after the first injection. CH
recurred in seven patients (39%) over the course of the study. Two of these
patients received a second injection, and both met with equal success. Two other
patients underwent PRFR. Excluding those who underwent PRFR, the overall daily
headache frequency decreased from 3.5 +/- 0.3 attacks per day preoperatively to
0.6 +/- 0.2 attacks per day at last follow-up. The severity of these headaches,
as assessed by verbal pain scales, also decreased from 10 preoperatively to 4.4
+/- 1.4 at follow-up. None of the patients, including those who required a second
procedure, experienced corneal anesthesia or facial dysesthesia. CONCLUSION: This
study provides the first long-term evaluation of PRGR for the treatment of
medically refractive chronic CH and lends support to both the safety and long
term efficacy of this procedure. Further investigations are needed to compare
directly the relative efficacy and safety of PRGR and PRFR.
PMID- 10690726
TI - Cowden disease and Lhermitte-Duclos disease: characterization of a new
phakomatosis.
AB - OBJECTIVE: Lhermitte-Duclos disease, or dysplastic gangliocytoma of the
cerebellum, is an unusual hamartomatous lesion that can cause progressive mass
effects in the posterior fossa. Cowden disease, or multiple hamartoma-neoplasia
syndrome, is a rare autosomal dominant disorder characterized by mucocutaneous
hamartomas and high incidences of systemic malignancies. We recently treated a
patient with manifestations of both Lhermitte-Duclos disease and Cowden disease,
and we were intrigued by the occurrence of these two rare disorders in the same
patient. The purpose of the present study was to examine the nature of the
association between Lhermitte-Duclos disease and Cowden disease. METHODS: The
records for all patients who had been diagnosed at our institution as having
Lhermitte-Duclos disease were reviewed, to determine whether these patients also
exhibited manifestations of Cowden disease. Data were obtained from multiple
sources, including patient interviews, correspondence with treating physicians,
and chart reviews. RESULTS: During the past 40 years, five patients were
diagnosed at Case Western Reserve University as having Lhermitte-Duclos disease.
All five patients exhibited manifestations of Cowden disease. Before this review,
Cowden disease had not been diagnosed for three of the patients. In our most
recent case, the diagnoses of both disorders were established preoperatively.
That patient was observed to have a deletion in the critical portion of Exon 5 of
the PTEN gene, the gene associated with Cowden disease. CONCLUSION: Inclusion of
Lhermitte-Duclos disease in the Cowden disease spectrum suggests that Cowden
disease is a true phakomatosis, with hamartomas arising from cutaneous and neural
ectoderm. Recent advances in molecular genetics may help to refine the current
descriptive classification of the phakomatoses. The association between Lhermitte
Duclos disease and Cowden disease has been under-recognized and under-reported.
Recognition of this association has direct clinical relevance, because diligent
long-term follow-up monitoring of individuals with Lhermitte-Duclos disease and
Cowden disease may lead to the early detection of malignancy.
PMID- 10690727
TI - Extreme lateral supracerebellar infratentorial approach to the posterolateral
mesencephalon: technique and clinical experience.
AB - OBJECTIVE: Lesions situated posterolaterally along the mesencephalon present
neurosurgeons with a special challenge. The midline and paramedian variations of
the supracerebellar infratentorial approaches do not adequately expose this
region. The subtemporal approach risks injury to the vein of Labbe. An extreme
lateral supracerebellar infratentorial approach with more radical resection of
bone superiorly and laterally, and skeletonization of the sigmoid and transverse
sinuses, was used to approach lesions at this location in eight METHODS: Five
cavernous malformations, two juvenile pilocytic astrocytomas, and one peripheral
superior cerebellar artery aneurysm located in this region were approached in
eight patients. In this extreme lateral approach, the sigmoid sinus is unroofed
more superiorly and the bone flap includes not only a posterior fossa craniotomy
but also a portion that extends just above the transverse sinus. The dural
opening is based along the transverse and sigmoid sinuses. After the
cerebrospinal fluid has been drained, the lateral aspect of the brainstem is
approached via the cerebellar surface. A proximal tentorial incision offers
additional rostral exposure where needed. RESULTS: Seven patients in this series
underwent successful resection of their lesion. The remaining patient's aneurysm
was clipped successfully with no major complications. CONCLUSION: The extreme
lateral supracerebellar infratentorial approach differs from the midline and
paramedian supracerebellar infratentorial variants in the area of exposure,
patient positioning, and location of the craniotomy. The technique is effective
for approaching the posterolateral mesencephalon.
PMID- 10690728
TI - Microelectrode-guided thalamotomy for Parkinson's disease.
AB - OBJECTIVE: To describe the outcomes in our first 40 microelectrode-guided
thalamotomies for parkinsonian tremor. METHODS: Twenty-four left-sided and 16
right-sided thalamotomies were performed between October 1984 and January 1996;
the mean follow-up period was 35.8 months (range, 1-152 mo). The results were
evaluated retrospectively and semiquantitatively by a disinterested observer
(MNL) and correlated with the quality of the microelectrode recording and the
number and size of radiofrequency lesions made. The first 20 and second 20
procedures were evaluated separately. RESULTS: At the last follow-up, the Unified
Parkinson's Disease Rating Scale showed no or virtually no tremor in the upper
limb in 75% of patients or in the lower limb in 73% of patients. No significant
persistent complications were found. These results were achieved at the expense
of having to repeat the procedure on 11 sides (in 5 because of technical problems
and in 6 for no obvious reason). Total or nearly total abolition of tremor
occurred after the first procedure in 40% of the first 20 operations and in 65%
of the second 20. Eight of the first 20 procedures and 2 of the second 20 failed
for technical reasons. Lesions were made larger in the second 20 procedures than
in the first 20. With the use of an electrode with a 1.1 x 3-mm bare tip for 60
seconds, it seems that lesions had to be created at 60 degrees C or more to
produce a successful result. CONCLUSION: Thalamotomy with microelectrode
recording is an effective procedure with which to treat tremor in patients with
Parkinson's disease and may involve fewer complications than conventional
techniques. The procedure appears to involve a learning curve.
PMID- 10690729
TI - Laminectomy versus percutaneous electrode placement for spinal cord stimulation.
AB - OBJECTIVE: The purpose of this study was to compare the long-term effectiveness
of spinal cord stimulation using laminectomy-style electrodes versus that using
percutaneously implanted electrodes. METHODS: Forty-one patients underwent an
initial trial period of spinal cord stimulation with temporary electrodes at Duke
Medical Center between December 1992 and January 1998. A permanent system was
implanted if trial stimulation reduced the patient's pain by more than 50%.
Median long-term follow-up after permanent electrode placement was 34 months
(range, 6-66 mo). Severity of pain was determined postoperatively by a
disinterested third party using a visual analog scale and a modified outcome
scale. RESULTS: Twenty-seven (66%) of the 41 patients participating in the trial
had permanent electrodes placed. Visual analog scores decreased an average of 4.6
among patients in whom electrodes were placed via laminectomy in the thoracic
region (two-tailed t test, P < 0.0001). Patients who underwent percutaneous
placement of thoracic electrodes had an average decrease of 3.1 in their visual
analog scores (two-tailed t test, P < 0.001). Electrodes placed through
laminectomy furnished significantly greater long-term pain relief than did those
placed percutaneously, as measured by a four-tier outcome grading scale (P =
0.02). CONCLUSION: Spinal cord stimulation is an effective treatment for chronic
pain in the lower back and lower extremities that is refractory to conservative
therapy. Electrodes placed via laminectomy in the thoracic region appear to be
associated with significantly better long-term effectiveness than are electrodes
placed percutaneously.
PMID- 10690730
TI - Reevaluation of syringosubarachnoid shunt for syringomyelia with Chiari
malformation.
AB - OBJECTIVE: The purpose of this study was to evaluate the effectiveness of
syringosubarachnoid (S-S) shunting for syringomyelia with Chiari malformation.
The authors describe the technical methods of performing the S-S shunt and the
clinical results, including shunt malfunction. METHODS: Forty-nine patients
underwent S-S shunting. These patients were divided into three groups according
to differences in the surgical technique used. Group I patients underwent
laminectomy plus midline myelotomy and had a shunt tube placed in the dorsal
subarachnoid space. Group II patients underwent laminectomy plus dorsal root
entry zone myelotomy and had a shunt tube placed in the dorsolateral subarachnoid
space. Group III patients underwent hemilaminectomy plus dorsal root entry zone
myelotomy and had a shunt tube placed in the ventrolateral subarachnoid space.
RESULTS: Clinical results were generally satisfactory, especially in terms of
pain relief, in all three groups. However, 10 patients among Groups I and II
required follow-up surgery because of shunt problems; no second surgery was
necessary for any patient in Group III. CONCLUSION: The S-S shunt was very
effective in deflating the syrinx, and the clinical results were satisfactory.
Therefore, even though foramen magnum decompression is a very effective
treatment, S-S shunting should be reevaluated and not rejected; it should be
considered as one of the major surgical options. To prevent the possibility of
cord injury by myelotomy or shunt malfunction, the dorsal root entry zone should
be selected as the myelotomy site, and the shunt tube should be inserted into the
ventral subarachnoid space at the cervical level.
PMID- 10690731
TI - A new technique for cranioplasty with L-shaped titanium plates and combination
ceramic implants composed of hydroxyapatite and tricalcium phosphate (Ceratite).
AB - OBJECTIVE: The use of hydroxyapatite-based ceramics for cranioplasties has
recently increased in Japan, because of the good cosmetic outcomes,
biocompatibility, strength, osteoconductive properties, and lack of risk of
disease transmission associated with these materials. However, miniplate fixation
has not been possible for ceramic implants. We describe a new technique for
miniplate fixation of ceramic implants. METHODS: Combination ceramic implants
composed of hydroxyapatite and tricalcium phosphate (Ceratite; NGK Spark Plug
Co., Aichi, Japan) were used for cranioplasties. A slot and a pair of holes were
cut in each Ceratite implant, for use as a fixation unit. We have also developed
a new L-shaped titanium plate (HOMS Engineering Inc., Nagano, Japan) that fits
into the fixation unit. We first insert an L-shaped titanium plate through the
slot from the back surface of the Ceratite implant. We then bend the plate
outward at the front surface of the Ceratite implant and fix it to the cranium of
the patient with titanium screws. The Ceratite implant is usually firmly fixed to
the cranium of the patient with three L-shaped titanium plates. RESULTS: Using L
shaped titanium plates and Ceratite implants, we successfully performed
cranioplasties for seven patients with cranial defects resulting from external
decompression craniotomies. The Ceratite implant exactly fit the bone window for
each patient. Surgical maneuvers were simple and easy for all patients,
permitting shorter operating times. All Ceratite implants were firmly fixed, and
no postoperative infections have occurred. CONCLUSION: Our new technique for
cranioplasty is simple and allows rigid fixation of Ceratite implants.
PMID- 10690732
TI - Retinoids inhibit human glioma cell proliferation and migration in primary cell
cultures but not in established cell lines.
AB - OBJECTIVE: Retinoids are known to exhibit a broad spectrum of biological
activities, and they participate in the onset of differentiation and the
inhibition of growth in a wide variety of cancer cells. Some of these vitamin A
derivatives are already in clinical use. However, data on retinoid actions in
glial tumors are rather sparse. Therefore, we studied the effects of the natural
retinoic acid (RA) forms all-trans-RA, 9-cis-RA, and 13-cis-RA on glioma cell
lines and primary cultures from patients with glioblastomas multiforme. METHODS:
Six human glioma cell lines, one rat glioma cell line, and 20 primary cultures
established from biopsies from patients with glioblastomas multiforme were
investigated. Tumor cell proliferation was assessed using 3-(4,5-dimethylthiazol
2-yl)-2,5-diphenyltetrazolium bromide and cell-counting assays. Random migration
out of tumor spheroids was quantified using a video-morphometry system. Invasion
was investigated using a confrontational coculture test system. Retinoid receptor
(RA receptor [RAR]alpha, -beta, and -gamma and retinoid X receptor [RXR]alpha,
beta, and -gamma) expression status was determined using reverse transcription
polymerase chain reaction studies. RESULTS: Treatment of five human glioma cell
lines with the different retinoids at concentrations up to 10(-5) mol/L produced
no reduction of proliferation, using various incubation times. For one human
glioma cell line (U343MG-A) and one rat glioma cell line (C6), which were
previously reported to be sensitive to retinoids, we could confirm strong
inhibitory effects on proliferation and clear changes in morphological features
after retinoid treatment. Application of the different retinoids to low-passage
primary cultures of human glioblastomas resulted in marked inhibition of
proliferation (30-95%) for all tested samples. Using three-dimensional spheroid
cultures, we detected retinoid-induced decreases in cell migration (24-65%).
Invasion was not affected by these vitamin A derivatives. In an analysis of the
expression patterns for retinoid receptors (RARs and RXRs), all primary culture
samples yielded positive results for RAR gamma and RXR alpha and negative results
for RAR alpha, RAR beta, and RXR gamma, whereas the results of RXR beta
expression were heterogeneous among different patients. The cell lines,
irrespective of their RA sensitivities, did not exhibit any major differences in
receptor expression. CONCLUSION: Retinoids strongly inhibit proliferation and
migration in primary cultures of human glioblastomas multiforme. Our data support
a clinical trial of retinoids for the treatment of human malignant gliomas. We
observed that most established cell lines were not sensitive to RA. This
difference between long-term cell lines and primary cultures cannot be explained
by different retinoid receptor expression patterns.
PMID- 10690733
TI - Induction of apoptosis in glioma cells by recombinant human Fas ligand.
AB - OBJECTIVE: Fas ligand (FasL) belongs to the tumor necrosis factor family and has
the ability to induce apoptosis in susceptible target cells by binding to its
receptor, Fas. It has been demonstrated recently that the FasL/Fas system plays a
pivotal role in the cytocidal activity of T lymphocytes in the immune system.
FasL may act as a cytotoxic effector molecule to Fas-expressing malignant tumor
cells. We reported previously that Fas is commonly expressed in human brain tumor
cells. In this study, we examine the possible application of FasL to therapy for
malignant brain tumors. METHODS: To develop an expression system yielding large
amounts of FasL, we constructed a baculovirus vector containing complementary
deoxyribonucleic acid of human FasL under the control of a polyhedrin promoter.
We produced human FasL in Spodoptera frugiperda (Sf9) insect cells infected by
the recombinant baculovirus carrying FasL complementary deoxyribonucleic acid and
studied the cytocidal activity of FasL against the T98G human glioblastoma cell
line. RESULTS: FasL expression in Sf9 cells was confirmed immunocytochemically
with rabbit antibody raised against the cytoplasmic domain of human FasL. The
FasL released into the supernatant of cultured Sf9 cells was also verified by
Western blotting, and it specifically induced apoptosis in T98G cells. The
induced apoptosis by recombinant human FasL was confirmed by annexin V
fluorescein isothiocyanate staining. CONCLUSION: The present results suggest that
the induction of apoptosis by the Fas/FasL system could be a new strategy for the
treatment of malignant brain tumors, which are resistant to conventional
therapies.
PMID- 10690734
TI - Thin and thick filament regulation of contractility in experimental cerebral
vasospasm.
AB - OBJECTIVE: Cerebral vasospasm is a potentially fatal consequence of aneurysmal
subarachnoid hemorrhage and influences the prognosis of the patient. The purpose
of this study was to evaluate the status of thin (actin) and thick (myosin)
filament regulation of smooth muscle contraction in the double-subarachnoid
hemorrhage canine model of cerebral vasospasm and to determine the effects of a
kinase inhibitor reported to be effective in vasospasm, HA1077, on thin and thick
filament regulation. METHODS: Cerebral vasospasm was assessed by vertebral
angiography. Myosin regulatory light chain phosphorylation was measured using
glycerol-urea gels, whereas protein levels of the thin filament-associated
protein calponin were measured by Western blot. RESULTS: The basilar arteries of
dogs in which subarachnoid hemorrhage was induced narrowed to 36% +/- 2.0% of
their size on the first day (n = 12). The phosphorylation of the regulatory light
chain tended to increase, but the change did not reach statistical significance
(35% +/- 5.9% [n = 12] versus 25% +/- 4.8% [n = 10] in control arteries). In
contrast to this increase, significant degradation of calponin was observed in
the samples from vasospastic dogs (85.4% +/- 5.45% [n = 5] versus 15.2% +/- 6.21%
[n = 5]; P < 0.01). Prophylactic treatment with intravenous injections of HA1077
at 0.67 mg/kg b.i.d. significantly inhibited vasospasm (diameters, 65% +/- 10.2%
of Day 1 diameters [n = 5]; P < 0.05), and calponin degradation (57.8% +/- 13.9%
[n = 4]) was substantially reduced. CONCLUSION: These data suggest that
degradation of the thin filament-associated protein calponin plays a role in
cerebral vasospasm and that the antivasospastic action of HA1077 is, at least in
part, due to prevention of calponin degradation.
PMID- 10690735
TI - In vivo animal models of cerebral vasospasm: a review.
AB - BACKGROUND: Cerebral vasospasm is delayed-onset cerebral arterial narrowing in
response to blood clots left in the subarachnoid space after spontaneous
aneurysmal subarachnoid hemorrhage (SAH). Ideally, studies on the pathogenesis
and treatment of cerebral vasospasm in humans should be conducted using human
cerebral arteries. Because in vivo experiments using human vessels are not
possible, and postmortem pathological examination of human arteries in vasospasm
provides only a limited amount of information, a number of animal models of
vasospasm have been developed. METHODS: The literature was searched to find all
references to in vivo animal models of SAH and vasospasm. An online search of the
medical database MEDLINE was initially performed using the key words "cerebral,"
"vasospasm," "subarachnoid," "hemorrhage," "animal," and "model." References were
checked to determine the first description of each in vivo animal model. RESULTS:
Fifty-seven models of SAH and vasospasm were identified. These models used one of
three techniques to simulate SAH: 1) an artery was punctured allowing blood to
escape and collect around the artery and its neighbors; 2) an artery was
surgically exposed, and autologous blood obtained from another site was placed
around the artery; or 3) blood from another site was injected into the
subarachnoid space and was allowed to collect around arteries. Each technique has
advantages and disadvantages. The majority of animal models of SAH and vasospasm
use intracranial arteries; however, extracranial arteries have also been used
recently in vasospasm experiments. These studies seem easier and less costly to
perform, but concerns exist regarding the physiological dissimilarity between
systemic and cerebral arteries. CONCLUSION: The model of SAH and vasospasm used
most frequently is the canine "two-hemorrhage" model, in which two injections of
blood into the dog's basal cistern performed 48 hours apart result in greater
arterial vasoconstriction than that effected by a single injection of blood. On
the basis of its ability to accurately predict what occurs in human SAH, the best
model of vasospasm seems to be the primate model in which a blood clot is
surgically placed around the large cerebral vessels at the base of the monkey's
brain.
PMID- 10690736
TI - A tribute to Dr. Fedor A. Serbinenko, founder of endovascular neurosurgery.
AB - From humble beginnings in the former Soviet Union, Fedor A. Serbinenko, M.D.,
Ph.D., became a leading figure at Moscow's famed Burdenko Neurosurgery Institute.
While there, he invented and perfected the technique of balloon embolization,
which was destined to change the practice of neurovascular surgery forever. We
present the life and achievements of the father of endovascular neurosurgery.
PMID- 10690737
TI - Origin and evolution of the Department of Neurosurgery, Neurological Institute,
Faculty of Medicine, Kyushu University.
AB - The Department of Neurosurgery at Kyushu University had its origins within the
First Department of Surgery and was established as a subspecialty at the
Neurological Institute more than 30 years ago under the leadership of Katsutoshi
Kitamura. Further development of the neurosurgical department has proceeded
during the chairmanship of Masashi Fukui. These leaders and many other dedicated
physicians and surgeons, nurses, investigators from other countries, and staff
members have contributed to the creation of a research-oriented neurosurgical
environment that interacts fruitfully with the other components of the
Neurological Institute. This article describes the development of neurosurgery
within Kyushu, which has been a highly cosmopolitan area throughout its long
history. More specifically, this account outlines the origin and growth of the
Department of Neurosurgery at Kyushu University.
PMID- 10690738
TI - Isolated cerebellar involvement in Rosai-Dorfman disease: case report.
AB - OBJECTIVE AND IMPORTANCE: Sinus histiocytosis or Rosai-Dorfman disease (RDD) is a
rare but well-recognized disorder characterized by an unusual proliferation of
histiocytic cells. Intracranial localization is a rare manifestation of RDD. Only
three cases of localization in the posterior fossa have been reported in the
literature. The present report describes the first case, to our knowledge, of
cerebellar localization of RDD. CLINICAL PRESENTATION: A 67-year-old woman was
admitted to our institution with a 5-month history of cerebellar ataxia. Her
medical history was unremarkable. The patient was alert and cooperative. No
cranial nerve deficits were evident; Romberg positivity to the left side was
recorded. No cutaneous abnormalities, lymphadenopathy, or hepatosplenomegaly were
revealed by physical examination. Routine hematological and biochemical studies
were normal except for the erythrocyte sedimentation rate, which was elevated.
Radiologically, the lesion appeared as a well-defined and avascular mass in the
right cerebellar lobe. Meningioma was considered the most likely diagnosis.
TECHNIQUE: The patient underwent a suboccipital craniotomy with complete excision
of the lesion. Microscopic examination of the operative specimen revealed the
presence of a mixed cellular population with predominant mature histiocytes. A
peculiar feature was the presence of lymphocytes and monocytes within the
cytoplasm of histiocytes (emperipolesis). Immunohistochemical study of the
histiocytes revealed strong positivity for S-100, CD-68 antigen, and vimentin.
CONCLUSION: Involvement of the central nervous system in RDD appears to have a
benign prognosis, especially in the absence of nodal diseases. Surgery is
essential for diagnosis, and, when total removal is achieved, the outcome is
generally good without risk of recurrence.
PMID- 10690739
TI - Radiographic evidence and surgical confirmation of a saccular aneurysm on a
hypoplastic duplicated A1 segment of the anterior cerebral artery: case report.
AB - OBJECTIVE AND IMPORTANCE: True duplication of the A1 segment of the anterior
cerebral artery is extremely rare, as is finding a true A1 segment saccular
aneurysm. We report the angiographic and surgical findings of such a case with
the additional association of a hypoplastic ipsilateral M1 segment of the middle
cerebral artery. CLINICAL PRESENTATION: A 68-year-old man presented with a Hunt
and Hess Grade II subarachnoid hemorrhage and symptoms of headache, nuchal
rigidity, and facial paresis. INTERVENTION: Angiographic evaluation with
superselective exploration revealed a small ruptured aneurysm located on a
duplicated hypoplastic A1 segment of the left anterior cerebral artery with
associated middle cerebral artery stenosis and secondary early moyamoya changes.
Surgical clipping of the aneurysm was performed successfully while sparing the
hypoplastic A1 segment. CONCLUSION: A1 aneurysms occurring on a duplicated
anterior cerebral artery segment probably develop from a congenital weakness of
the parent vessel and increased local shear stress. Superselective angiography
was helpful in the preoperative planning and facilitated the decision to treat
with surgical clipping instead of embolization.
PMID- 10690740
TI - Spontaneous spinal cord herniation: case report and review of the literature.
AB - OBJECTIVE AND IMPORTANCE: Spontaneous herniation of the spinal cord substance
through a previously uninjured and/or untouched dura is a very exceptional
occurrence. Spontaneous spinal cord herniation, which was first reported 25 years
ago, is a cause of myelopathy that is treatable but difficult to diagnose.
CLINICAL PRESENTATION: A 49-year-old female patient who presented with a 3-year
history of a burning sensation and hyperesthesia in her right leg and a 3-month
history of left leg stiffness was diagnosed as exhibiting signs of Brown-Sequard
syndrome. Magnetic resonance imaging of the thoracic spinal canal demonstrated S
shaped anterior kinking and transdural herniation of the spinal cord at the T3-T4
levels. INTERVENTION: The patient underwent surgery via a three-level
laminectomy. The herniated part of the spinal cord was microsurgically reduced,
and the dural defect was repaired with Gore-Tex membrane (WL Gore & Associates,
Flagstaff, AZ). The outcome of surgery was excellent. CONCLUSION: Review of the
world literature revealed 29 reported cases, with 27 of these cases being
published since 1990. The clinical features, radiological diagnosis, and
treatment options for this unique entity are summarized, with a synopsis of
numerous misconceptions that appeared in the literature. With more familiarity
with and increased awareness of this entity, more cases will be diagnosed.
PMID- 10690741
TI - Progressive spontaneous herniation of the thoracic spinal cord: case report.
AB - OBJECTIVE AND IMPORTANCE: We report one case of spontaneous thoracic spinal cord
herniation. To our knowledge, this is the first case involving radiological
documentation of the development of herniation. Clinical features and surgical
techniques are also presented. CLINICAL PRESENTATION: We describe the case of a
51-year-old female patient who experienced progressive Brown-Sequard syndrome for
2 years. Three magnetic resonance imaging examinations were performed; they
revealed the progressive development of anterolateral spinal cord herniation at
the level of T6 during those 2 years. INTERVENTION: After laminectomy at T6, the
herniated myelon was microsurgically removed and the neurological symptoms
improved. CONCLUSION: We present the possible causes, the proposed
pathophysiological mechanisms, and the clinical and radiological development of
this rare entity, with a review of the literature published to date. We propose
that a preexisting weakness of the ventral dural fibers, combined with abnormal
adhesion of the spinal cord to the anterior dural sleeve, leads to progressive
herniation throughout life. Microsurgical treatment may halt the exacerbation of
the neurological symptoms.
PMID- 10690742
TI - Endovascular treatment of a grade IV transverse sinus dural arteriovenous fistula
by sinus recanalization, angioplasty, and stent placement: technical case report.
AB - OBJECTIVE AND IMPORTANCE: The frequent association of dural arteriovenous
fistulae (DAVFs) and dural sinus thrombosis may render the treatment of these
complex lesions difficult. We report a case of DAVF eradicated by recanalization
of the chronically thrombosed transverse sinus (TS) and sigmoid sinus followed by
balloon angioplasty and stent deployment at the site of the fistula. CLINICAL
PRESENTATION: A 52-year-old man presented with a Type IV DAVF of the left TS with
widespread white matter changes secondary to venous hypertension. Arterial
feeders arose from the left internal carotid, external carotid, and vertebral
arteries. The distal segment of the left TS, the left sigmoid sinus, and the
proximal segment of the right TS were occluded. Reverse flow was observed in the
deep venous system and in the superior sagittal sinus. INTERVENTION: Endovascular
access was gained through the left internal jugular vein. Mechanical
recanalization of the thrombosed left TS and sigmoid sinus was followed by
balloon angioplasty and placement of six overlapping stents extending from the TS
to the proximal internal jugular vein. Angiograms performed after surgery showed
resaturation of antegrade venous drainage as well as complete eradication of the
fistulous connections. The patient was discharged with an improving clinical
CONCLUSION: Recanalization of a chronically occluded dural venous sinus through a
jugular approach is feasible. In addition to eradicating cerebral venous
hypertension by reestablishing antegrade venous drainage, balloon angioplasty and
stent deployment at the DAVF site produced complete closure of the fistula. This
may prove to be a new therapeutic strategy for management of DAVF.
PMID- 10690743
TI - Navigus trajectory guide.
PMID- 10690744
TI - Prognostic value and determinants of ultraearly angiographic vasospasm after
aneurysmal subarachnoid hemorrhage.
PMID- 10690745
TI - Patients with spinal cord cavernous malformations are at an increased risk for
multiple neuraxis cavernous malformations.
PMID- 10690746
TI - Stereotactic targeting of the globus pallidus internus for Parkinson's disease:
imaging versus electrophysiological mapping.
PMID- 10690747
TI - History of the operating microscope: from magnifying glass to microneurosurgery.
PMID- 10690748
TI - Flurothyl-induced seizures in rats activate Fos in brainstem catecholaminergic
neurons.
AB - Autonomic changes accompany seizures in both animals and humans. While ictal
autonomic dysfunction can be life-threatening, the participating neural networks
involved are poorly understood. In this study we examined the activation of Fos
following generalized seizures in brainstem structures known to mediate autonomic
function. Adult female rats were sacrificed 2 h after flurothyl-induced seizures.
Double-immunostaining for c-Fos and dopamine-beta-hydroxylase (DBH), and c-Fos
and phenylethanol-N-methyl-transferase (PNMT) were performed in brainstem slices.
Numbers of DBH-labeled neurons expressing Fos-like immunoreactivity (FLI)
(DBH/Fos) and PNMT labeled neurons expressing FLI (PNMT/Fos) were counted in the
noradrenergic (A1, A2, A5, A7) and adrenergic (C1, C2) cell groups localized in
pons and medulla oblongata. Among the experimental animals, the highest degree of
co-localization of DBH/Fos neurons was observed in the locus coeruleus (A6;
87.7%), and in the A1(72.8%) cell group located in the caudal ventrolateral
medulla (VLM). No co-localization of DBH/Fos neurons was observed in control
animals. The highest degree of co-localization of PNMT/Fos neurons was observed
in the C1 adrenergic cell group (84.2%) located in the rostral VLM. Control
animals showed very few (5.5%) PNMT/Fos co-localized neurons in the C1 adrenergic
cell group. Our results indicate that flurothyl-induced generalized seizures in
rats activate catecholaminergic neurons in the pons and medulla oblongata.
Further studies are necessary to determine whether activation of brainstem
catecholaminergic neurons contribute to the autonomic manifestations that
frequently accompany epileptic seizures.
PMID- 10690749
TI - Neocortical hyperexcitability after GABA withdrawal in vitro.
AB - The sharp interruption of the intracortical instillation of exogenous gamma
aminobutyric acid (GABA), generates an epileptic focus in mammals. Seizures
elicited by GABA withdrawal last several days or weeks. The present work reports
that GABA withdrawal-induced hyperexcitability can be produced in vitro: a sudden
withdrawal of GABA (5 mM; 120 min) or benzodiazepine (60 microM flunitrazepam)
from the superfusion, induced a gradual increase in the amplitude of the evoked
population spike (PS) recorded on neocortical slices. PS enhancement reached 150%
above the control value 2.5 h after GABA withdrawal. GABA withdrawal-induced
hyperexcitability was facilitated by progesterone. PS enhancement induced by GABA
withdrawal was associated with an impairment of GABA transmission occurring
before epileptiform discharges were fully established. Paired pulse inhibition
and evoked [3H]-GABA release appear decreased; suggesting that cortical
hyperexcitability as a result of GABA withdrawal involves pre-synaptic changes.
Specific muscimol binding decreased during GABA superfusion but recovered after
GABA withdrawal. However, the sensitivity of the post-synaptic response to 3alpha
OH-5alpha-pregnan-20-one or allopregnanolone (alloP) was enhanced after GABA
withdrawal, suggesting a functional change in the GABA(A) receptors. The changes
described may be the cellular correlates of the withdrawal syndromes appearing
after interruption of the administration of GABA(A) receptor agonists.
PMID- 10690750
TI - No association found between polymorphisms in genes encoding mGluR7 and mGluR8
and idiopathic generalised epilepsy in a case control study.
AB - The genes of two group III metabotropic glutamate receptors, mGluR7 and 8, are
candidate susceptibility genes for epilepsy. The Tyr433Phe polymorphism of mGluR7
and a novel polymorphism in the mGluR8 gene located 29 bp after the termination
codon (2756C/T) were investigated in case control association studies performed
on DNA from more than 100 patients with idiopathic generalised epilepsy (IGE). No
significant association was found with IGE for either polymorphism.
PMID- 10690751
TI - Running down phenomenon and acute interictal psychosis in medial temporal lobe
epilepsy.
AB - PURPOSE: To examine the relationship between presurgical acute interictal
psychosis and postsurgical running down phenomenon in a strictly homogeneous
group with medial temporal lobe epilepsy. METHODS: Forty patients with mesial
temporal sclerosis and an ultimate excellent surgical outcome, were divided into
running down positive and negative groups. Various clinical and laboratory data,
including presurgical psychotic episodes, were analyzed in the two groups.
RESULTS: Patients in the running down positive group exhibited a significantly
high incidence of presurgical history of acute interictal psychosis. CONCLUSION:
We hypothesize that areas of secondary epileptogenesis beyond the scope of the
primary epileptogenic zone, suggested by postsurgical running down phenomenon,
may play an important role in the blockage and shift of the habitual propagation
of seizure activity from the primary epileptogenic zone, to which Wolf attributed
acute interictal psychosis.
PMID- 10690752
TI - Acute behavioral and EEG effects of NW-1015 on electrically-induced
afterdischarge in conscious monkeys.
AB - NW-1015 is a novel Na+ and Ca2+ channel blocker with broad spectrum
anticonvulsant activity and an excellent safety margin. As the compound also
shows sigma-1 receptor ligand properties it was deemed important to determine
whether it possesses anticonvulsant properties in primates without causing
behavioral and EEG abnormalities. Thus, the effects of NW-1015 on limbic
electrically-induced afterdischarge (AD) were evaluated in four cynomolgus
monkeys, and its activity compared to a single effective dose of phenytoin (PHT).
The four male cynomolgus monkeys were chronically implanted for EEG recordings,
from cortex and limbic structures. AD was induced in limbic areas by electrical
stimulation. The effects of NW-1015 on the duration and the behavioral component
of the AD were randomly tested at doses from 25 to 75 mg/kg and compared with the
effects of PHT 50 mg/kg. Similarly to PHT, 50 mg/kg of NW-1015 significantly
shortened the EEG AD and almost abolished AD elicited behavioral seizure. Only
the behavioral effects of AD were reduced after administration of 25 mg/kg p.o.
NW-1015 did not cause EEG or interictal behavioral alterations at doses up to 75
mg/kg p.o. These data further confirm the broad-spectrum anticonvulsant activity
and a good safety profile of NW-1015 even in a primate model of complex partial
seizures and suggest that its affinity for sigma-1 receptors is behaviorally
irrelevant.
PMID- 10690753
TI - Felbamate block of recombinant N-methyl-D-aspartate receptors: selectivity for
the NR2B subunit.
AB - The anticonvulsant felbamate blocks N-methyl-D-asparate (NMDA) receptors but
fails to exhibit the neurobehavioral toxicity characteristic of other NMDA
receptor antagonists. To investigate the possibility that felbamate's favorable
toxicity profile could be related to NMDA receptor subtype selectivity, we
examined the specificity of felbamate block of recombinant NMDA receptors
composed of the NR1a subunit and various NR2 subunits. Felbamate produced a
rapid, concentration-dependent block of currents evoked by 50 microM NMDA and 10
microM glycine in human embryonic kidney 293 cells expressing the rat NR1a
subunit, and either the NR2A, NR2B or NR2C subunits; the IC50 values for block
were 2.6, 0.52 and 2.4 mM, respectively (holding potential, - 60 mV). The Hill
coefficient values were < 1 and, in kinetic analyses, onset and recovery from
block were well fit by double exponential functions, indicating binding to more
than one blocking site on the NMDA receptor channel complex. The higher affinity
of felbamate block of NMDA receptors containing the NR2B subunit could be
accounted for by more rapid association and slower dissociation from these sites.
We conclude that felbamate exhibits modest selectivity for NMDA receptors
composed of NR1a/NR2B subunits. This selectivity could, in part, account for the
more favorable clinical profile of felbamate in comparison with NMDA receptor
antagonists that do not show subunit selectivity.
PMID- 10690754
TI - Genetic variation of the human mu-opioid receptor and susceptibility to
idiopathic absence epilepsy.
AB - Pharmacological and autoradiological studies suggest that mu-opioid receptor
(OPRM) mediated neurotransmission is involved in the generation of absence
seizures. Mutation screening of the human OPRM gene identified a common amino
acid substitution polymorphism (Asn40Asp) that differentially modulates the
binding affinity of beta-endorphin and signal transduction of the receptor. The
present association study tested the candidate gene hypothesis that the Asn40Asp
substitution polymorphism in the N-terminal OPRM domain confers genetic
susceptibility to idiopathic absence epilepsy (IAE). The genotypes of the
Asn40Asp polymorphism were assessed by allele-specific polymerase chain reaction
in 72 German IAE patients and in 340 ethnically matched control subjects. The
frequency of the Asp40 allele was significantly increased in the IAE patients
[f(Asp40) = 0.139] compared to the controls [f(Asp40) = 0.078; chi2 = 5.467, df =
1, P = 0.019; OR = 2.03; 95%-CI: 1.12-3.68]. This allelic association suggests
that the functional Asp40 variant of OPRM modulates neuronal excitability
underlying the epileptogenesis of IAE.
PMID- 10690755
TI - CNS oxidative stress associated with the kainic acid rodent model of experimental
epilepsy.
AB - The role of oxidative stress in seizure-induced brain injury was investigated in
a kainic acid model of experimental epilepsy. Kainic acid (12.5 mg/kg) or saline
was injected intraperitoneally into 12-week-old male Fischer 344 rats and
sacrificed by decapitation at 4 and 24 h after injection. Markers of oxidative
stress including protein carbonyls, thiobarbituric acid reactive material
(TBARs), glutathione (GSH) and glutathione disulfide (GSSG) were measured in
hippocampus, cortex, cerebellum and basal ganglia. Four hours after treatment,
protein carbonyls were elevated by 103, 55, 52 and 32% in cortex, hippocampus,
basal ganglia and cerebellum, respectively. TBARs were increased by 30-45% in all
areas. After 24 h, elevated protein and lipid oxidative markers persisted in the
hippocampus and cerebellum; by contrast, in the cortex, TBARs almost normalized
to control values and protein carbonyls trended downward by one-half compared
with measurements at 4 h, although this reduction relative to the 4 h timepoint
did not reach statistical significance. In the basal ganglia, protein carbonyls
approached control values at 24 h. GSSG levels were only increased statistically
in the cortex after 4 h, GSH levels in all the regions were unchanged after
treatment with kainic acid. However, in cortex, GSH levels correlated negatively
with increases in protein and lipid oxidation (r = -0.69, P < 0.002). In
contrast, significant correlations between GSH, protein carbonyls and TBARs
measured in the hippocampus or cerebellum were not observed. Our data suggests
that kainic acid induced similar oxidative stress in all of the brain regions
that were examined, and that GSH plays a major antioxidant role in the cerebral
cortex but not the hippocampus.
PMID- 10690756
TI - A questionnaire survey about doctor-patient communication, compliance and locus
of control among south Indian people with epilepsy.
AB - To date, very few studies have investigated patients' views on the information
they receive from the doctor concerning epilepsy and its management. Little
information is available about the influence of doctor-patient communication and
locus of control on the compliance of persons with epilepsy. We investigated,
through a questionnaire-interview design, among patients attending the epilepsy
clinic of a tertiary referral center in South India, their views about the
provision of information by the doctor, and their compliance and locus of
control. We also determined the interrelation between doctor-patient
communication, compliance and locus of control. Our subjects comprised 200 adult
persons with epilepsy, 113 males and 87 females, mean age 30.5 (range 18-67)
years. Over one-third of the subjects received from the doctor insufficient
information about epilepsy and its treatment. There was a significant positive
correlation between effective doctor-patient communication and compliance. A
majority of our patients had an external locus of control, which negatively
influenced the compliance. Even in a comprehensive epilepsy clinic of a model
tertiary referral center in a developing country, a significant proportion of
patients do not receive optimal information about epilepsy from the doctor.
Knowledge about their disease will encourage people with epilepsy to make
informed choices, and achieve better compliance and personal control of their
problems. Educating primary and secondary care physicians about the importance of
doctor-patient communication in the management of epilepsy and educating the
public about the positive aspects of life in epilepsy cannot be overemphasized.
PMID- 10690757
TI - Report of the Coding Committee of the Association for European Paediatric
Cardiology.
PMID- 10690758
TI - The European Paediatric Cardiac Code Long List: structure and function.
PMID- 10690759
TI - Inhibitors on an elastase-like enzyme activity catalyzing Suc-Ala-Ala-Pro-Leu-pNA
amidolysis in human seminal plasma.
AB - The behavior of some proteinase inhibitors toward the Suc-Ala-Ala-Pro-Leu-pNA
amidolytic enzyme activity in human seminal plasma (HSP) was tested. [(2S, 3R)-3
Amino-2-hydroxy-5-methyl-hexanoyl]L-valyl-L-valyl-L-aspartic acid (Amastatin) and
3-[1-[(2-(hydroxymethyl)- -pyrolidinyl)-2-methylpropyl]-carbamoyl]
octanohydroxamic acid (Actinonin) showed strong inhibitory effects. No inhibition
of this present enzyme activity was seen with anti-human serum (whole), anti
human leukocyte elastase, phenyl-methyl sulfonyl fluoride, Elastatinal,
ethyeneglycol bis(beta-aminoethyl ethyl)N,N,N:N'-tetra acetic acid, and [L-3
trans-ethoxycarbonyl-oxirane-2-carbonyl]1-L-leucine(3-methylbutyl)a mido (E-64).
No relation was observed between human pancreatic elastase antigen and the Suc
Ala-Ala-Pro-Leu-pNA amidolytic enzyme enzyme activity in HSP. Two peaks of Suc
Ala-Ala-Leu-Pro-pNA amidolytic enzyme activity were separated by Cellulofine GCL
2000 gel filtration and these activities were completely abolished by addition of
Amastatin. Suc-Ala-Ala-Pro-Leu-pNA amidolytic enzyme activity in HSP is not an
elastase-like metalloproteinase but is rather an acyl amidase-like leucine
aminopeptidase.
PMID- 10690760
TI - Effect of immunization with synthetic peptide corresponding to region 1-17 of
human seminal plasma inhibin on fertility of male rats.
AB - Immunization of adult male rats with a synthetic peptide corresponding to the
region 1-17 of human seminal plasma inhibin (hSPI) resulted in agglutination of
epididymal sperm, severely affecting the fertility of the animals (75% reduction
in fertility as compared to control). This effect was found to be dependent on
the antibody titer to hSPI. There was a significant rise in circulating follicle
stimulating hormone levels, with luteinizing hormone and testosterone levels
remaining unaffected. The histology of the testes and other reproductive organs
revealed that these organs remained unaltered. The N-terminal 1-17 amino acid
peptide of hSPI may hold promise as an immunogen for male immunocontraception.
PMID- 10690761
TI - Antioxidative effect of melatonin on human spermatozoa.
AB - The ability of melatonin to suppress experimentally induced lipid peroxidation
(LPO) in sperm membrane was investigated in 41 samples of infertile men.
Iron/ascorbate (0.04/0.2 mmol)-induced LPO was measured by the formation of
malondialdehyde (MDA) using the thiobarbituric acid method. Sperm incubated in
the presence of melatonin (2-6 mmol) exhibited a concentration-dependent decrease
of MDA generated from hydroperoxide of the sperm plasma membrane in the presence
of promoter system. Addition of 6 mmol of melatonin significantly reduced the
rate of lipid peroxidation in sperm of unselected donors (mean +/- SE in control
samples = 26.4 +/- 2.9 vs. 6.5 +/- 1.1 nmol MDA/10(8) sperm in melatonin-treated
samples: n = 16, p < .005). Inhibitory effect of melatonin was also significant
in the presence of 0.015 mmol of ferrous ions (20.5 +/- 1.7 vs. 7.9 +/- 1.6 nmol
MDA/10(8) sperm in melatonin-treated samples: n = 7, p < .02) and (.005 mmol of
ferrous ions (20.2 +/- 2.8 vs. 9.9 +/- 2.4 nmol MDA/ 10(8) sperm: n = 6, p <
.05). Comparing the effect of melatonin with that of Trolox, an analog of vitamin
E. a similar effect at concentration of 0.1-0.2 mmol of Trolox was found (25.2 +/
2.9 vs. 11.8 +/- 1.2 nmol MDA/10(8) sperm in Trolox-treated samples: n = 7, p <
.005). The obtained data of in vitro experiments show that melatonin is 40-fold
less efficient than Trolox in achieving the 50% reduction in LPO (4 vs. 0.1
mmol). Since the physiological concentration of melatonin in human semen is at
the nanomolar level, its antioxidative role in vivo is probably of minor
importance.
PMID- 10690762
TI - Autostage sperm tracing system for semen evaluation.
AB - To overcome the limitation of the microscope field, the study proposed an
autostage sperm tracing system (ASTS), which could trace a particular sperm for a
long time and distance. The ASTS was constructed by assembling a commercial
microscope, an image frame grabber, a personal computer, and a motorized stage.
Its performance was tested by evaluating 6 semen samples and by comparing the
evaluation with those of other semen evaluations. The ASTS broke through the
limitation of the microscope field and traced a particular sperm as long as
possible. It analyzed the sperm track and calculated the motility parameters,
such as curvilinear velocity (Vcl), straight-line velocity (Vsl), and linearity
(L(in)). The sperm quality was then evaluated in real time, and the user could
decide to capture or abandon a particular sperm in the IVF The ASTS enables users
to evaluate sperm progression for a long time and to have the global quality of a
particular sperm in real time. Its open structure has the flexibility for
micromanipulating a semen sample, and has the potential application associated
with a modern IVF technique.
PMID- 10690763
TI - A study of to determine if limiting the contact of sperm with zona pellucida
reduces the rate of spontaneous abortions.
AB - A recent study suggested that oligoasthenozoospermia may be an etiologic factor
for spontaneous abortion (SAB) after in vitro fertilization-embryo transfer (IVF
ET). However, IVF-ET with intracytoplasmic sperm injection (ICSI) did not seem to
be associated with an increased SAB rate. The study presented herein compared the
rate of SAB in pregnancies achieved by IVF-ET according to the type of oocyte
insemination process. The 3 types evaluated were conventional insemination, which
exposed the oocyte to 25,000 sperm with prolonged contact (16-24 h), intermediate
contact with a short insemination protocol where contact with 25,000 sperm was
limited to 2 h, and very limited contact with ICSI, where only 1 sperm was
injected into the oocyte thus not exposing the zona pellucida to any sperm. The
patients were further subdivided into age groups of < or =39 or > or =40. SAB
rates after frozen ET were also evaluated. The clinical pregnancy and SAB rates
following fresh or frozen ET for conventional, ICSI, and short insemination
techniques for the 2 age groups were comparable. These data question whether
oligoasthenozoospermia may be a factor in causing SAB, and whether avoidance of
contact with the zona pellucida by using ICSI can negate this effect. A larger
study is needed.
PMID- 10690764
TI - Separation of sperm through a 12-layer percoll column decreases the percentage of
sperm staining with quinacrine.
AB - Previous methods of enriching sperm with a higher percentage of Y-bearing sperm
have been questioned because the claims that Y enrichment was present were based
on quinacrine staining of the Y chromosome, and the enrichment was not confirmed
by polymerase chain reaction (PCR) or fluorescent in situ hybridization (FISH)
techniques. A technique was evaluated that theoretically could increase the
percentage of X-bearing sperm by isolating a fraction of the "heaviest" sperm by
passing them through 12 layers of discontinuous Percoll gradient. Initially 12
specimens were checked both before and then after separation with 12 layers of
Percoll for percentage of Y sperm. The median for baseline Y percentage was 49%
and after processing the percentage of Y dropped to 10%. An additional 19
specimens were checked after separation only. The median was 19%. The sample with
the lowest preseparation % of quinacrine staining sperm was 45% and the highest
was 54%. After 12-layer Percoll, the lowest percentage was 3% and the highest was
24%. There have been claims that quinacrine staining can falsely increase
apparent Y-bearing sperm enrichment following certain separation procedures,
e.g.. albumin separation, by nonspecific staining of autosomal chromosomes. If
anything, then, it should falsely decrease X-bearing sperm enrichment. Thus, 12
layer Percoll separation may actually enrich for X-bearing sperm or possibly this
procedure somehow nonspecifically inhibits the ability of quinacrine to stain the
Y chromosome.
PMID- 10690765
TI - Ultrastructural investigation of human sperm using atomic force microscopy.
AB - Ultrastructural investigation of human sperm in its natural environment (without
fixation, dehydration, embedding, sectioning, etc.) was carried out by using
atomic force microscope (AFM) in its tapping mode. This technique permits the
examination of fine structural details of undamaged sperm and its topography with
precision. Moreover, it allows 3D reconstruction of images and enhances the
contrast to resolve details such as mitochondria that surround the axoneme at the
sperm middle piece. An organized structure has been found in the flageller
axoneme region. Ultrastructure also reveals folding and details of the depression
of the membrane that cannot be examined with conventional techniques.
PMID- 10690766
TI - A modified acrosome induction test.
AB - Many types of acrosome induction tests require special equipment and reagents
that are not available to most clinicians; thus, simpler tests seem desirable. A
modified acrosome induction test has been developed that uses basic reagents and
a light microscope, which are available in most office settings. A hypoosmotic
swelling test and a double stain (Bismark brown and rose Bengal) were combined to
evaluate the viable acrosome reaction (AR) among 74 infertile men and 42 control
men. The study included 34 infertile males without varicoceles, 20 with
nonrepaired varicoceles and 20 with repaired varicoceles. On each test day, a
specimen from a fertile donor was run as a control. The spontaneous acrosome
reaction was recorded in semen before and after capacitation. The final % viable
acrosome reaction equaled the capacitated value minus the spontaneous value for
whole semen. The mean % viable AR among the control specimens was 16% with no
values less than 10%. This mean value for controls was significantly greater than
the mean % viable AR in each patient group. There were no overlaps in the 95%
confidence intervals. When the study group was stratified according to normal
acrosome induction tests or >10% viable AR, 30 patients had a normal test and 44
had abnormal tests. Six patients with varicoceles and an abnormal acrosome
induction test had a varicocelectomy, and 2 (33%) converted their acrosome
induction test to normal after at least 6 months of follow-up. Nine patients had
in vitro fertilization (IVF), 3 had a poor result, and all had an abnormal
acrosome induction test. Six had a good result with IVF and all 6 had a normal
acrosome induction test. Thus, the acrosome induction test described in this
report may be performed in any office laboratory to detect subtle male factor
problems. The results may be helpful for planning IVF, intracytoplasmic sperm
injection, or varicocele surgery for infertile men.
PMID- 10690767
TI - Semen analysis at the turn of the century: an evaluation of potential uses of new
sperm function assays.
AB - Semen analysis is a critical assay in the evaluation of infertility and may yield
critical information regarding the etiology and prognosis of many types of
reduced male fertility. However, basic semen analysis does not directly measure
sperm fertilizing capacity, or many of the biochemical events both prior to and
subsequent to fertilization. In the last two decades numerous assays of sperm
function have been developed. These assays can be classified as: 1) Assays of
general biochemistry and ultrastructure, 2) Assays of zona binding and oocyte
penetration, and 3) Assays of postpenetration events. Sperm function assays not
only allow an accurate diagnosis of many infertilities not diagnosed by the semen
analysis, but can also lead to improved treatment modalities. In this review,
basic semen analysis and many sperm function assays are briefly reviewed. Novel
uses of sperm function are demonstrated in brief case studies.
PMID- 10690768
TI - Mechanism of ejection during ejaculation: identification of a urethrocavernosus
reflex.
AB - The ejaculatory mechanism involves 2 reflexes: the "glans-vasal," which seems to
bring the semen to the posterior urethra (emission phase of ejaculation), and the
"urethromuscular" which ejects it to the exterior (ejection phase). This study
investigated the mechanism of bulbocavernosus muscle (BCM) contraction, once the
seminal fluid reaches the bulbous urethra. The study included 14 healthy male
volunteers (mean age 37 +/- 10.2 SD years). To test the response of the BCM to
urethral distension, a 10F balloon-tipped catheter was introduced into the
prostatic urethra and filled with saline in increments of 0.25 mL: a needle
electrode recorded the response. The balloon was then withdrawn to lie in the
membranous. bulbous, and pendulous urethra and the test was repeated at each
site. The latency of the muscle response was calculated. The BCM response to each
of the anesthetized bulbous urethra and anesthetized BCM was recorded. Distension
of the prostatic, membraneous, or pendulous urethra effected no BCM EMG response.
Bulbous urethral distension with 0.25 mL of saline also produced no muscle
response, whereas distension with 0.5 mL and up to 1.5 mL caused increased EMG
activity of the BCM. The muscle response augmented with the increase of the
distending volume. The mean latency was 10 +/- 1.3 ms and showed no significant
change (p > .05) with the different distending volumes. Neither the anesthetized
bulbous urethra nor the anesthetized BCM responded to bulbous urethral
distension. The BCM contraction upon distension of the bulbous urethra is
probably reflex and mediated through the urethrocavernosus reflex. Small-volume
distension did not effect BCM contraction. The latter presumably propels the
semen from the posterior to the pendulous urethra. It is suggested that the
urethrocavernosus reflex be included in current andrologic investigations for
patients with ejaculatory disorders.
PMID- 10690769
TI - Porcine circoviruses: a review.
AB - Porcine circoviruses (PCV) are small nonenveloped DNA viruses containing a unique
single-stranded circular genome. Previously, no recognized link was found between
PCV infection of pigs and disease, and PCV was considered a nonpathogenic agent.
Over the last 5 years, a "novel" PCV, designated PCV2, has been associated with
various disease syndromes in pigs, primarily postweaning multisystemic wasting
syndrome (PMWS). Pigs with PMWS have a variety of clinical signs, including
debility, dyspnea, palpable lymphadenopathy, diarrhea, and pallor or icterus.
Lesions associated with the presence of PCV2 in a variety of cell types include
lymphohistiocytic to granulomatous interstitial pneumonia, hepatitis, nephritis,
myocarditis, enteritis, and pancreatitis. The lesions of PMWS have been
reproduced experimentally after inoculation of piglets with PCV2 cell culture
isolates, although the full expression of the disease syndrome may require the
presence of other agents such as porcine parvovirus or porcine reproductive and
respiratory syndrome (PRRS) virus. Recent reports have linked PCV2 to other
disorders in pigs, ranging from abortion and reproductive failure to "atypical"
PRRS. Available data indicate high seroprevalence of antibodies to PCV2
worldwide. The diagnosis of PCV2-associated disease is based on the direct
demonstration of PCV2 antigens or nucleic acid in affected tissues. PCV2 is now
regarded as an important emerging pathogen. Although vertical transmission has
been documented, the epidemiology of PCV2 infections is poorly understood, as is
the role of the immune response in controlling or augmenting disease.
PMID- 10690770
TI - Gas chromatography/mass spectrometry identification and quantification of
isazophos in a famphur pour-on and in bovine tissues after a toxic exposure.
AB - A sample identified as "Warbex pour-on," expected to contain 13.2% famphur, and
bovine tissue samples from 2 heifers that died after exhibiting signs of
organophosphate intoxication were analyzed by gas chromatography/mass
spectrometry (GC/MS). A product formulation problem was suspected because brain
cholinesterase activities were depressed in both animals. Electron impact (EI)
GC/MS of the pour-on revealed 9.7% famphur and an unidentified peak with
approximately 76% of the peak area of the famphur. The unidentified peak showed a
molecular ion at m/z 313, with a single Cl isotope cluster. Methane chemical
ionization (MeCI) MS confirmed the molecular weight at 313 (1 Cl). A search on
the molecular formula C9H17N3O3PSCl yielded a single match, isazophos. EI and
MeCI GC/MS of reference isazophos confirmed the identity of the suspect peak. The
concentration of isazophos in the pour-on was determined to be 6.0%. Famphur and
isazophos were identified by their EI spectra and GC retention times in extracts
of liver and brain from the 2 deceased animals. A GC/MS procedure utilizing
selected ion monitoring (SIM) was developed for quantification of isazophos in
liver, kidney, muscle, and fat of additional affected animals sacrificed at
various times after exposure. Isazophos remained in animal tissues for as long as
94 days after topical exposure. Isazophos was present in fetal liver 70 days
after exposure of the dam. High levels (6-3,500 ppm) of isazophos and famphur
remained on the skin at 39 days postexposure.
PMID- 10690771
TI - Coinfection by porcine circoviruses and porcine parvovirus in pigs with naturally
acquired postweaning multisystemic wasting syndrome.
AB - Postweaning multisystemic wasting syndrome (PMWS) is an emerging disease in
swine. Recently, the disease has been reproduced with inocula containing a newly
described porcine circovirus (PCV), designated PCV 2, and porcine parvovirus
(PPV). In order to determine if these viruses interact in naturally acquired
PMWS, affected tissues from field cases were examined by immunohistochemistry
(IHC) and polymerase chain reaction (PCR) for PCV 2 and PPV, as well as by PCR
for the other recognized porcine circovirus, PCV 1. Porcine circovirus 2 was
detected by PCR or IHC in affected fixed or frozen tissues from 69 of 69 cases of
PMWS collected over 3 years from 25 farms. Porcine parvovirus was detected in 12
of the same cases, and PCV 1 was detected in 9 of 69; however, an apparent
decrease was found in the sensitivity of the PCRs used to detect the latter 2
viruses when fixed tissue from the same cases were compared with the use of
frozen tissues. Porcine circovirus 2 was not detected by PCR in affected tissues
from 16 age-matched pigs that had Streptococcus suis-associated disease. Electron
microscopic examination of plasma pooled from 15 pigs with PMWS revealed the
presence of PCV and PPV, whereas these viruses were not observed in pooled plasma
from 5 age-matched clinically normal pigs. These results confirm and extend
previous findings documenting a consistent association of PCV 2 with PMWS. As
well, infection by PPV or PCV 1 or both may be an important cofactor in the
pathogenesis of some, but apparently not all, cases of PMWS.
PMID- 10690772
TI - Improvement of western blot test specificity for detecting equine serum
antibodies to Sarcocystis neurona.
AB - Equine protozoal myeloencephalitis (EPM) is a neurological disease of horses and
ponies caused by the apicomplexan protozoan parasite Sarcocystis neurona. The
purposes of this study were to develop the most stringent criteria possible for a
positive test result, to estimate the sensitivity and specificity of the EPM
Western blot antibody test, and to assess the ability of bovine antibodies to
Sarcocystis cruzi to act as a blocking agent to minimize false-positive results
in the western blot test for S. neurona. Sarcocystis neurona merozoites harvested
from equine dermal cell culture were heat denatured, and the proteins were
separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in a 12
20% linear gradient gel. Separated proteins were electrophoretically transferred
to polyvinylidene fluoride membranes and blocked in 1% bovine serum albumin and
0.5% Tween-Tris-buffered saline. Serum samples from 6 horses with S. neurona
infections (confirmed by culture from neural tissue) and 57 horses without
infections (horses from the Eastern Hemisphere, where S. neurona does not exist)
were tested by Western blot. Horses from both groups had reactivity to the 62-,
30-, 16-, 13-, 11-, 10.5-, and 10-kD bands. Testing was repeated with another
step. Blots were treated with bovine S. cruzi antibodies prior to loading the
equine samples. After this modification of the Western blot test, positive
infection status was significantly associated with reactivity to the 30- and 16
kD bands (P<0.001, Fisher's exact test). The S. cruzi antibody-blocked Western
blot had a sample sensitivity of 100% and sample specificity of 98%. It is
concluded that the specificity of the Western blot test is improved by blocking
proteins not specific to S. neurona and using reactivity to the 30- and 16-kD
bands as the criterion for a positive test.
PMID- 10690773
TI - Bovine viral diarrhea virus cytopathic and noncytopathic biotypes and type 1 and
2 genotypes in diagnostic laboratory accessions: clinical and necropsy samples
from cattle.
AB - One hundred three bovine samples submitted to the Oklahoma Animal Disease
Diagnostic Laboratory (OADDL) that were positive for bovine viral diarrhea virus
(BVDV) were typed by a nested reverse transcription-polymerase chain reaction for
BVDV genotypes. These BVDV samples included supernatants from virus isolation
(79), serums (17), and buffy coats (7). The biotype, cytopathic (CP) or
noncytopathic (NCP), was determined by cell culture virus isolation. Twenty-eight
of 103 samples were submitted for herd screening for BVDV, 32 from OADDL necropsy
cases, and 43 from live cattle with varied clinical conditions. Two samples
contained 2 bands indicating presence of both BVDV types 1 and 2. Of the 105 BVDV
samples, 26 were type 1 CP strains (24.8%), 38 were type 1 NCP strains (36.2%),
10 were type 2 CP strains (9.5%), and 31 were type 2 NCP strains (29.5%). From
the 105 BVDV isolates, NCP biotypes were isolated more frequently (69, 65.7%)
than CP biotypes (36, 34.3%), and type 1 genotypes were more frequently isolated
(64, 61.00%) than type 2 genotypes (41, 39.0%). The NCP strains were more common
than CP in herd screening samples. Cattle with respiratory disease history at
time of sampling had more NCP than CP biotypes and more type 1 than type 2
genotypes. Of the necropsy cases, more were type 1 than type 2 genotypes for the
respiratory cases with fibrinous pneumonia, more were type 1 than type 2
genotypes in cattle with enteritis/colitis without systemic lesions, and more
were CP than NCP biotypes in cattle with enteritis/colitis with systemic lesions.
No CP biotype was isolated from serum samples.
PMID- 10690774
TI - Common variable immunodeficiency in miniature dachshunds affected with
Pneumonocystis carinii pneumonia.
AB - Seven miniature dachshunds, all under the age of 1 year, were presented with
polypnea, tachypnea, and exercise intolerance as a result of Pneumocystis carinii
pneumonia, which was diagnosed on transtracheal aspirate cytology. In all of the
dogs, historical and clinical signs were suggestive of immune incompetence.
Immunological studies undertaken were leukogram parameters, serum immunoglobulin
fraction quantification, lymphocyte transformation assay. CD3 and CD79a
lymphocyte markers on lymphoid tissue, and anti-canine immunoglobulin G
immunoperoxidase staining. The immunological studies showed
hypogammaglobulinemia, deficiency of serum immunoglobulins A, G, and M, decreased
lymphocyte transformation response to phytohemagglutinin and pokeweed mitogens
and absence of B lymphocytes with presence of T lymphocytes in the lymphoid
tissue stained with CD3 and CD79a lymphocyte markers. The preceding findings
suggest that P. carinii pneumonia occurring in the miniature dachshund is a
result of both a T- and B-cell deficiency. This presentation is not the classic
primary severe combined immunodeficiency syndrome but rather combined variable
immunodeficiency, which has been well documented in humans but never in the dog.
PMID- 10690775
TI - Procedurally similar competitive immunoassay systems for the serodiagnosis of
Babesia equi, Babesia caballi, Trypanosoma equiperdum, and Burkholderia mallei
infection in horses.
AB - Procedurally similar competitive enzyme-linked immunoassay (cELISA) methods were
developed for the serodiagnosis of Babesia equi and Babesia caballi
(piroplasmosis), Trypanosoma equiperdum (dourine), and Burkholderia mallei
(glanders) infections in horses. Apparent test specificities for the B. equi, B.
caballi, T. equiperdum, and B. mallei cELISAs were 99.2%, 99.5%, 98.9%, and
98.9%, respectively. Concordances and kappa values between the complement
fixation (CF) and the cELISA procedures for the serodiagnosis of B. equi, B.
caballi, T. equiperdum, and B. mallei infections in experimentally exposed horses
were 76% and 0.55, 89% and 0.78, 97% and 0.95, and 70% and 0.44, respectively.
The cELISA method may be a technically more reproducible, objective, and
convenient approach for piroplasmosis, dourine, and glanders serodiagnosis in
qualifying animals for international movement and disease eradication programs
than the CF systems currently in use. Use of the cELISA method also obviated the
problems associated with testing hemolyzed or anticomplementary sera.
PMID- 10690776
TI - Correlation of two nonradioactive immunoassays to a radioimmunoassay technique
for thyroxine measurement in equine serum.
AB - The purpose of this study was to compare 2 different nonradioactive assay methods
with a conventional radioimmunoassay (RIA) measuring the concentration of serum
thyroxine (T4) in horses. Serum was obtained from 85 adult standardbred horses.
The T4 concentration of each sample was analyzed by RIA, chemiluminescent enzyme
immunoassay (CEI), and homogeneous enzyme immunoassay (HEI). The correlation
between the HEI method and RIA method was significantly greater (r = 0.89) than
the correlation between the CEI and the reference method (r = 0.53). In addition,
the precision of the HEI method was significantly greater than the CEI method;
within-run percentage coefficients of variation were 4.5% and 15.9%,
respectively, at mean T4 concentrations of 19-20 nmol/liter. On the basis of
these findings, the HEI method was evaluated further. Both between-run precision
and linearity were deemed adequate upon dilution by the HEI method. In addition,
recovery of L-thyroxine added to equine serum was linear over 6 concentrations
tested and averaged 79.6% with a manufacturer recommended data correction factor.
An in-house correction factor was calculated by linear regression analysis of the
RIA and HEI results from the original equine serum samples. Use of this
correction factor improved the average recovery to 94.2% while maintaining
excellent linearity (r2 = 0.9978). Although both nonradioactive methods of T4
analysis could likely substitute for the RIA reference method, the HEI method had
the highest correlation and precision. The HEI technique also yielded adequately
accurate results after correction of the data with an appropriate correction
factor. Individually derived in-house correction factors may improve the accuracy
of the HEI method to a greater extent than manufacturer suggested correction
factors.
PMID- 10690777
TI - Detection and differentiation of Mycobacterium avium and Mycobacterium genavense
by polymerase chain reaction and restriction enzyme digestion analysis.
PMID- 10690778
TI - Immunohistochemical detection of Mycobacterium paratuberculosis in formalin
fixed, paraffin-embedded bovine tissue sections.
PMID- 10690779
TI - Influence of storage and temperature on endospore and enterotoxin production by
Clostridium perfringens in dogs.
PMID- 10690780
TI - Isolation of avian paramyxovirus serotype 3 from domestic fowl in Israel: close
antigenic relationship with the psittacine strain of avian paramyxovirus serotype
3.
PMID- 10690781
TI - Pituitary abscess in young calves associated with the use of a controlled
suckling device.
PMID- 10690782
TI - Extradural myelolipoma in a dog.
PMID- 10690783
TI - Diagnostic performance of a reverse transcription-polymerase chain reaction test
for porcine reproductive and respiratory syndrome virus.
PMID- 10690785
TI - Isolation of Jamestown Canyon virus (California virus group) from vesicular
lesions of a horse.
PMID- 10690784
TI - Companion animals as reservoirs of eaeA+ Escherichia coli.
PMID- 10690786
TI - Improved plating media for the detection of Salmonella species with typical and
atypical hydrogen sulfide production.
AB - The Salmonella detection ability of 2 surfactant-supplemental media, xylose
lysine-tergitol (Nia-proof) 4 (XLT4) and Miller-Mallinson (MM) agar, was compared
against that of several commonly used plating media. XLT4 and MM appeared to be
the most efficient in detecting Salmonella in meat products and food animal
environments. MM was superior to XLT4 in detecting those increasingly more
prevalent strains of Salmonella possessing weak to ultraweak H2S production
characteristics.
PMID- 10690787
TI - Canine distemper virus infection in binturongs (Arctictis binturong).
PMID- 10690788
TI - Intrapelvic hemangiosarcoma in a horse.
PMID- 10690789
TI - Pneumococcal vaccines for the world.
PMID- 10690790
TI - A brief history of pneumococcal vaccines.
AB - Attempts to control pneumococcal infection by vaccination, undertaken initially
in 1911, have gone through 3 phases during the subsequent 8 decades. Initially,
vaccines of killed pneumococcal cells prepared in a variety of ways were used in
epidemic settings with inconclusive results, although administered to
approximately 1 million recipients. The discovery that adults injected with small
amounts of purified capsular polysaccharide developed antibodies to the
homologous capsular type led to the trial of a tetravalent vaccine that showed
conclusively its ability to prevent infection by the types represented in it.
With the advent of penicillin and other effective antipneumococcal drugs,
interest in prophylaxis waned. Interest in vaccination was revived only after
demonstration that some segments of the population remained at high risk of death
if infected and after the emergence of multidrug-resistant pneumococci. Infants
and young children, among whom the incidence of pneumococcal infection is high,
respond poorly to purified bacterial polysaccharides but develop satisfactory
responses to bacterial polysaccharides when these are linked chemically to a
protein. The early results of trials with such polysaccharide protein conjugate
vaccines give promise that control of a significant portion of pneumococcal
infection in the paediatric population will soon be feasible.
PMID- 10690791
TI - Epidemiology of pneumococcal infections in the elderly.
AB - The risk of invasive Streptococcus pneumoniae infection (primarily bacteraemia
and meningitis) is greatest among the very young and the very old. Persons in
certain racial groups, including African-Americans, American Indians, Native
Alaskans and Australian Aborigines, are also at increased risk of disease. Other
factors that appear to increase the risk of pneumococcal infection are lower
socioeconomic status, recent infection with influenza and possibly other viral
respiratory tract infections, chronic medical conditions, and immunosuppressive
medications. Reported annual incidences of invasive pneumococcal disease among
persons aged > or = 65 years in North America and Europe range from 25 to 90
cases/100,000 persons. In the US and Canada, these rates represent between 15,000
and 30,000 cases annually among the elderly. Mortality caused by pneumococcal
infections is highest among the elderly, with nearly 1 in 5 cases resulting in
death. Worldwide, S. pneumoniae is the leading cause of community-acquired
pneumonia requiring hospitalisation. The high fatality rates, as well as recent
outbreaks of pneumococcal infection among unvaccinated nursing home residents and
the emergence of drug-resistant pneumococcal strains, highlight the importance of
preventing invasive infection by vaccination.
PMID- 10690792
TI - Pneumococcal vaccination for older adults: the first 20 years.
AB - During the 20 years following its licensure, pneumococcal vaccine has not been
widely used. Although the vaccine was shown to be efficacious in South African
gold miners, clinical trials of 'pneumonia vaccine' in older adults that have
attempted to demonstrate vaccine efficacy in preventing pneumonia have been
inconclusive. Retrospective studies have convincingly demonstrated the
effectiveness of vaccination in preventing invasive pneumococcal disease, but
these findings have only gradually gained acceptance, largely because some
observers reject the findings of observational studies or fail to appreciate the
importance of invasive disease. In the 1980s, pneumococcal vaccine was used only
in the US, but other countries began vaccination in the mid-1990s, in part due to
a better understanding of the disease and the vaccine, but also because of
concern about antimicrobial resistance. With greater understanding of the global
importance of pneumococcal disease and the promise of conjugate and protein
vaccines, during the next 20 years pneumococcal vaccines will become the most
important vaccines for adults and children worldwide.
PMID- 10690793
TI - Assessing the potential cost effectiveness of pneumococcal vaccines in the US:
methodological issues and current evidence.
AB - Pneumococcal disease imposes a notable burden on society, particularly in the
elderly and those at high risk of complications. Preventive strategies,
especially vaccines, are possibly the best way to minimise such a burden. We
report on the conduct and results of a preliminary exploratory review of the
economics of pneumococcal vaccines in the elderly population in the US. After
extensive electronic and manual searches, we identified 5 economic evaluations
that fulfilled our study criteria. From these we extracted key economic variables
and assessed the quality of the studies against the criteria in the checklist for
authors and peer reviewers of economic submissions to the British Medical
Journal. We found variation of quality of study design such as a lack of clarity
in the treatment of indirect costs and a failure to present the data on resource
use and costs separately. We carried out supplementary searches to assess the
quality of the epidemiological and efficacy evidence upon which the economic
models were based and found contradictory evidence of effects of the vaccines,
which included the results of 2 meta-analyses. One of these meta-analyses
reported that retrospective studies, especially case-control studies, tended to
underestimate the protective efficacy of the vaccine by as much as 20%. We
believe that a well resourced Cochrane review of the clinical evidence of the
effects of the vaccines should be carried out before any further economic
studies. No more economic modelling should take place before such a review is
undertaken.
PMID- 10690795
TI - Safety of simultaneous pneumococcal and influenza vaccination in elderly patients
in Brazil.
PMID- 10690794
TI - Pneumococcal vaccine in the elderly: the Norwegian experience.
AB - Pneumococcal infections have increased during the last 10 to 15 years in Norway.
Their incidence is now about 20 per 100,000 population for all age groups, but is
2 to 3 times higher among the elderly. In 1996, the Advisory Board of Infectious
Disease Control, National Institute of Public Health, Norway, recommended that
pneumococcal polysaccharide vaccine should be administered to all individuals
aged > or = 65 years. This recommendation has led to an increased use of
pneumococcal vaccine, with a marked peak during the influenza vaccination season.
PMID- 10690796
TI - Potential biochemical markers of uterine receptivity.
AB - Implantation in humans is a complex process that involves embryo apposition and
attachment to the maternal endometrial epithelium, traversing adjacent cells of
the epithelial lining, and invasion into the endometrial stroma. These processes
involve a variety of molecules which are not unique in themselves, but play
unique roles in the process of implantation. The molecular dialogue that occurs
between the implanting conceptus and the endometrium involves cell-cell and cell
extracellular matrix interactions, mediated by lectins, integrins, matrix
degrading enzymes and their inhibitors, prostaglandins, and a variety of growth
factors, cytokines, and angiogenic peptides, their receptors and modulatory
proteins. It is likely that each of these, when appropriately expressed or
inhibited, contributes to endometrial receptivity or non-receptivity to an
implanting conceptus. Currently, a working definition of a receptive versus a non
receptive endometrium is incomplete. While histological normality of the
endometrium does not necessarily imply functional normality, temporal and spatial
expression of particular biochemical principles in the endometrium are highly
suggestive of functional roles of these principles in implantation and
endometrial receptivity. These potential markers of endometrial receptivity are
discussed herein. It is envisioned that as regulation of these markers is
elucidated, their expression may be manipulated to improve implantation rates and
fertility or to limit implantation for successful contraception.
PMID- 10690797
TI - MUC-1 glycosylation in endometrium: possible roles of the apical glycocalyx at
implantation.
AB - MUC-1 is a major epithelial apical surface glycoprotein in human endometrium. It
has a large, extended and highly glycosylated ectodomain that contains keratan
sulphate chains. MUC-1 is abundant at the luminal epithelial surface in the
receptive phase, but keratan sulphate disappears at this time. MUC-1 has been
shown experimentally to inhibit cell-cell interactions by steric hindrance of
binding interactions mediated by receptors, including integrins and cadherins, so
its high abundance at the time of implantation is unexpected. Here, various
models for MUC-1 function in implantation are considered and its expression in
different species compared. The possible evolutionary advantages of a maternal
'barrier' to implantation are discussed.
PMID- 10690798
TI - Immunological aspects of implantation and implantation failure.
AB - The human endometrium contains a significant proportion of leukocytes (8-35% of
all cells), the absolute numbers and proportions varying during both the
menstrual cycle and early in pregnancy. T cells, macrophages and a population of
phenotypically unusual large granular lymphocytes (LGL) are commonly present,
although B cells are absent. Relative T cell numbers decrease significantly in
first trimester decidua, and hence are unlikely to play an important role in
maintenance of human pregnancy, but T cells could be important in implantation
where their relative numbers are greater. In addition to producing cytokines,
local tissue macrophages may provide an immediate antigen non-specific host
defence to infection. Most attention has, nevertheless, focused on a role for LGL
in implantation and maintenance of pregnancy since, at the time of implantation,
LGL comprise 70-80% of the total endometrial leukocyte population. Although
endometrial LGL have been shown to express natural killer (NK) cell-type
cytotoxicity against classical NK cell targets, such cytotoxicity against
trophoblast is induced only after activation by interleukin (IL)-2. Selective
expression of the unusual class I human leukocyte antigen (HLA) molecule, HLA-G,
by extravillous cytotrophoblast may assist in protecting invasive cytotrophoblast
from potential maternal NK cell attack, probably via interactions with killer
inhibitory receptor molecules on LGL. Many cytokines have been demonstrated to be
expressed at the maternal-fetal interface although, currently, in mice only two
(IL-11 and leukaemia inhibitory factor) appear to be absolutely essential for
successful pregnancy outcome. Immune effector cells and cytokines may also play a
role in human pregnancy pathologies, such as recurrent early pregnancy loss.
PMID- 10690799
TI - Cell-surface morphological events relevant to human implantation.
AB - Morphological evidence on early stages of human implantation is limited to very
few sporadic observations. The nature of implantation which requires the presence
of both maternal and embryonic tissues, combined with the currently existing
ethical constraints on human studies, appear to preclude generation of new data.
However, research on relevant animal and in-vitro models as well as studies on
human endometrium and in-vitro embryos, allow some indirect insights to this
phenomenon. This review summarizes information on cell-surface morphological
events relevant to implantation initiation, derived from scanning electron
microscopy studies on the above systems. A central part of this article deals
with the formation of epithelial cell projections known as pinopodes, for there
is increasing evidence suggesting that these structures are closely associated
with the development of endometrial receptivity for blastocyst implantation in
humans.
PMID- 10690800
TI - Blastocyst invasion and the stromal response in primates.
AB - One of the most remarkable processes associated with the establishment of
pregnancy in the primate is the process of decidualization. This transformation
of a stromal fibroblast to a fully differentiated decidual cell is required for
implantation and embryo survival in early pregnancy. Although the morphological
and biochemical characteristics of the primate decidual cell have been
extensively studied, the precise cellular, biochemical and molecular signals
required for this transformation have yet to be elucidated. During
decidualization, stromal cells first proliferate and then differentiate. Based on
our extensive in-vivo and ongoing in-vitro studies, we have suggested that the
process of decidualization in the baboon can be divided into two distinct phases.
The initial proliferative phase is characterized by the expression of the
cytoskeletal protein alpha smooth muscle actin (alphaSMA) in the stromal
fibroblasts and is independent of the presence of the conceptus. The second phase
of differentiation is characterized by the expression of insulin-like growth
factor binding protein-1 (IGFBP-1) and the down-regulation of alphaSMA in the
decidualized stromal fibroblast. The expression of IGFBP-1 is dependent on the
presence of the conceptus in vivo and is regulated by hormones and cAMP in vitro.
We have postulated that, during the initial phase of stromal cell
differentiation, alphaSMA expression is regulated by the interaction between
stromal cell integrins with the secreted extracellular matrix proteins (ECM). In
response to pregnancy a trophoblast 'factor', mediated by cAMP signal
transduction, induces IGFBP-1 expression in decidualizing stromal fibroblasts.
This induction of IGFBP-1 is associated with the disappearance of alphaSMA and de
novo protein synthesis. Our comparative studies suggest that the process of
decidualization in the human and baboon involve similar mechanisms. However, the
metabolic pathways required for decidualization in the two species appear to
differ in their degree of sensitivity to external stimuli. This review focuses on
the cellular events that may potentially regulate decidualization in the primate
and its role in regulating trophoblast migration.
PMID- 10690801
TI - Invasive cytotrophoblast apoptosis in pre-eclampsia.
AB - Pre-eclampsia is a serious pregnancy complication diagnosed by signs of
widespread maternal endothelial dysfunction. In normal pregnancy, a subpopulation
of placental cytotrophoblast stem cells executes a differentiation programme that
leads to invasion of the uterus and its vasculature. This process attaches the
conceptus to the uterine wall and starts the flow of maternal blood to the
placenta. In pre-eclampsia, cytotrophoblasts fail to differentiate along the
invasive pathway. The functional consequences of this abnormality negatively
affect interstitial and endovascular invasion, thereby compromising blood flow to
the maternal-fetal interface. To determine whether abnormal differentiation
and/or hypoxia leads to apoptosis of invasive cytotrophoblasts, we used the TUNEL
(terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling) method
to label DNA strand breaks in tissue sections of the placenta and the uterine
wall to which it attaches. Control samples (n = 9) showed little or no apoptosis
in any location, but in samples from patients with pre-eclampsia, 15-50% of the
cytotrophoblast subpopulation that invaded the uterine wall was labelled (8/9
samples). These same cells failed to stain for Bcl-2, a survival factor normally
expressed by trophoblasts in both the placenta and the uterine wall. Our results
show that pre-eclampsia is associated with widespread apoptosis of
cytotrophoblasts that invade the uterus. The magnitude of programmed cell death
in this population may account for the sudden onset of symptoms in some patients,
as well as the associated coagulopathies.
PMID- 10690802
TI - The relevance of the peritoneal fluid in endometriosis-associated infertility.
AB - Endometriosis, one of the most prevalent gynaecological disorders, may affect
fertility. Extensive research has been done in an attempt to understand the
pathogenesis of endometriosis and its association with reproductive failure. It
has been suggested that the disease affects almost any step of reproduction, but
data are mostly controversial so it is difficult to draw clear conclusions from
studies that have been done so far. Not only is peritoneal fluid in close
proximity to endometriotic lesions, but it is also the environment in which early
reproductive events take place. Studies on the peritoneal fluid in endometriosis
have provided significant data towards an understanding of this disease.
Immunological factors play a key role in determining the occurrence of
endometriosis as well as its heterogenous symptoms. Since data also indicate that
there are immunological differences between infertile and fertile women with
endometriosis, recent studies have been designed to take these differences into
consideration. This review will discuss the mechanisms by which endometriosis may
affect fertility, and an emphasis will be placed on the relevance of the
peritoneal fluid.
PMID- 10690803
TI - Is the endometrium or oocyte/embryo affected in endometriosis?
AB - One of the most puzzling problems of endometriosis is determining which
mechanisms link this spectrum of conditions to infertility. There is conflicting
evidence about the effect of endometriosis on the endometrium and on
oocyte/embryo quality. Clinical studies reveal that implantation rates seem to be
lower in women with endometriosis, while spontaneous abortion rates show variable
results which are difficult to interpret due to the design of the studies.
Biochemical markers (integrins and other cell adhesion molecules), morphological
markers (pinopodes), apoptosis and ultrasound studies confirm that not only does
the endometrium from women with endometriosis behave differently from the
endometrium of women without endometriosis, but ectopic endometrium also behaves
differently from eutopic endometrium. Data from oocyte donation programmes
suggest that oocyte quality may be hampered in women with endometriosis. Recent
reports have focused on the molecular mechanisms that may be altered, such as
ovarian steroid production, or inadequate luteal function. In this review, we
analyse the most recent literature dealing with the different mechanisms which
affect the endometrium and oocyte/embryo quality and which thereby might cause
infertility.
PMID- 10690804
TI - Role of the IGF system in trophoblast invasion and pre-eclampsia.
AB - Insulin-like growth factor-II (IGF-II) and IGF binding protein-1 (IGFBP-1) appear
to play an important role in paracrine interactions at the maternal-fetal
interface in human pregnancy. Patterns of expression of IGF-II and IGFBP-1 at the
decidual-trophoblast interface suggest paracrine interactions occur between the
IGF-II-expressing invading cytotrophoblast and maternal decidua-derived IGFBP-1.
Autocrine/paracrine actions of trophoblast-derived IGF-II may be important in
invasion, and for both trophoblast and decidual function. The actions of IGFBP-1
in binding IGF, and as an integrin ligand, suggest it may have multiple roles in
the interactions between the invading trophoblast and the maternal decidua.
Abundant decidual IGFBP-1 may interact with the IGF-II-expressing, protease
secreting trophoblast to modulate invasion. In-vitro studies of trophoblast
decidual cell interactions in invasion, and clinical observations in a
gestational disorder with shallow placental invasion such as pre-eclampsia, have
provided new insights into the possible role(s) of IGFBP-1 in trophoblast
invasion. The precise mechanisms underlying IGF and IGFBP-1 action at the
decidual-trophoblast interface remain to be elucidated. The potential predictive
value of serum IGFBP-1 concentrations in pre-eclampsia also remains to be
established.
PMID- 10690805
TI - Pinopodes as markers of endometrial receptivity in clinical practice.
AB - Clinical evidence indicates the existence in the human of a narrow window of
uterine receptivity which opens during the mid-luteal phase. At the same time,
formation of pinopodes on the apical membranes of the endometrial epithelial
cells occurs. To develop a specific marker for receptivity in clinical practice,
the kinetics of pinopode formation has been investigated through sequential
endometrial biopsying in natural, hormone replacement and stimulated cycles. The
results show that pinopodes last <48 h in all cycles, and the timing of their
formation depends both on the hormonal treatment applied and on the patient's
individual response. On average, pinopodes form earlier in stimulated cycles and
later in hormone replacement cycles, compared with natural cycles. Pinopode
expression is strongly correlated with implantation following embryo transfer and
furthermore, detection of pinopodes in assessment cycles may be extremely useful
for the assessment of receptivity on an individual basis to optimize embryo
transfer, resulting in increased implantation rates. Finally, pinopodes seem to
be correlated well with other cellular and molecular events occurring in the mid
luteal endometrium.
PMID- 10690806
TI - Ovarian stimulation and endometrial receptivity.
AB - Endometrial receptivity is a limiting step in the success of in-vitro
fertilization (IVF). To investigate this issue, we selected a specific population
of high responder patients in whom implantation was impaired, even when good
quality embryos were transferred. We present a series of studies showing that
high oestradiol concentrations on the day of human chorionic gonadotrophin (HCG)
administration are detrimental to uterine receptivity. In addition, we suggest
clinical strategies to improve endometrial receptivity in high responder patients
using a step-down regimen.
PMID- 10690807
TI - Use of co-culture of human embryos on Vero cells to improve clinical implantation
rate.
AB - Co-culture of human embryos (n = 384 cycles) to the blastocyst stage using Vero
cell monolayers was carried out between August 1995 and December 1997. A total of
2868 zygotes were co-cultured and 1027 embryos reached the blastocyst stage
(blastocyst formation rate 35.8%). The blastocysts were frozen in 43.7% of
patients. A mean of 1.8 blastocysts was transferred per patient and 95
pregnancies were obtained (pregnancy rate/cycle 24.7%). The blastocyst
implantation rate was 23.6%. Miscarriage occurred in 15 patients (15.7%) and
ectopic pregnancy in three (3.1%) patients. The multiple pregnancy rate was
32.6%. No differences were observed in the blastocyst rate between poor, normal
or high response patients. Blastocyst formation was significantly lower when
frozen donor spermatozoa were used. Significantly higher pregnancy rates per
transfer and blastocyst implantation rates were attained when embryos were
transferred on days 5 or 6 compared with day 7. No advantage was observed when co
culture was used in first cycle IVF patients, in comparison with conventional day
2 replacements. The use of blastocysts for preimplantation genetic diagnosis
(PGD) increases the diagnostic reliability and widens diagnostic possibilities. A
total of 215 cycles with frozen-thawed co-cultured blastocysts were carried out,
with a pregnancy rate of 22.7% per replacement.
PMID- 10690808
TI - The mechanism of accommodation in primates.
PMID- 10690809
TI - Underestimation of intraocular lens power for cataract surgery after myopic PRK.
PMID- 10690810
TI - Augmentation of filtering blebs with perfluoropropane gas bubble.
PMID- 10690811
TI - Augmentation of filtering blebs with perfluoropropane gas bubble.
PMID- 10690812
TI - Sclerosing sweat duct carcinoma of the eyelid margin: unusual presentation of a
rare tumor.
PMID- 10690813
TI - Acute corneal necrosis after excimer laser keratectomy for hyperopia.
PMID- 10690814
TI - Intraocular lens power calculation after corneal refractive surgery remains
challenging.
PMID- 10690815
TI - To my dismay
PMID- 10690816
TI - The National Eye Institute's low vision education program: improving quality of
life.
PMID- 10690817
TI - The South Asian cataract management study: complications, vision outcomes, and
corneal endothelial cell loss in a randomized multicenter clinical trial
comparing intracapsular cataract extraction with and without anterior chamber
intraocular lens implantation.
AB - OBJECTIVE: To determine clinical outcomes of primary intracapsular cataract
surgery with and without implantation of anterior chamber lenses. DESIGN: A
multicenter randomized clinical trial. PARTICIPANTS: One thousand two hundred
twenty-nine male and female patients 40-75 years of age with senile cataract.
METHODS: Study patients were recruited from screening eye camps and outpatient
clinics. Randomization to the two treatment groups was performed after screening
for predetermined inclusion and exclusion criteria. Demographics, visual acuity,
intraocular pressures, and corneal endothelial cell data were recorded before
surgery and at 6 weeks, 12 months, and 24 months after surgery. Monitoring of the
study was secured by a standardized image documentation procedure on all patients
using the IMAGEnet digital imaging system. Analysis of corneal endothelial cell
images was performed with the Cell Soft software (Topcon Corporation, Japan).
MAIN OUTCOME MEASURES: Visual acuity and central corneal endothelial cell loss.
RESULTS: The patients were randomized to intraocular lens (IOL; n = 616) and no
IOL (n = 613) implantation. Surgical complications were reported in 177 (14.4%)
patients (IOL = 14.8%; no IOL = 14.0%). The most frequent complication observed
was vitreous loss which occurred in 10.3% of eyes (IOL = 11.2%; no IOL = 9.5%).
At the final examination (2 years after surgery), 88% of the operated eyes had a
best corrected vision of 6/18 or better (IOL = 88.8%; no IOL = 86.6%). Analysis
of corneal endothelial cell data showed a small but significantly greater cell
loss 6 weeks after surgery in eyes with IOL compared with those without IOL, but
no overall difference was found between the treatment groups in the long term
follow-up. CONCLUSIONS: The findings indicate that there is a rationale for the
use of anterior chamber intraocular lenses in primary intracapsular cataract
surgery.
PMID- 10690818
TI - Inflammation after sclerocorneal versus clear corneal tunnel phacoemulsification.
AB - OBJECTIVE: To compare the postoperative inflammation after phacoemulsification
followed by intraocular lens (IOL) implantation by means of sclerocorneal versus
clear corneal tunnel incision. DESIGN: Randomized controlled clinical trial.
PARTICIPANTS: One hundred eyes of 100 patients were examined at a German
University eye hospital. INTERVENTION: One hundred eyes with cataract
necessitating phacoemulsification with posterior chamber IOL implantation were
randomly assigned to receive a temporal sclerocorneal or clear corneal tunnel
incision by a single surgeon. MAIN OUTCOME MEASURES: Preoperative and
postoperative inflammation was evaluated by measurement of flare using laser
flare photometry. Statistical inference was mainly based on nonparametric group
comparisons by use of two sample Wilcoxon tests. RESULTS: Mean anterior chamber
flare in the group with sclerocorneal tunnel increased from 7.5 photon counts/ms
preoperatively to 19.6 at 6 hours postoperatively and decreased to 11.1 (day 1),
11.7 (day 2), 11.6 (day 3), and 9.2 (5 months) during the postoperative course.
The mean flare in the clear corneal tunnel incision group increased from 7.7
preoperatively to 12.9 at 6 hours postoperatively and then decreased to 9.2 (day
1), 9.8 (day 2), 9.1 (day 3), and 9.2 (5 months). Individual postoperative flare
changes were significantly lower in the clear corneal tunnel group at the day of
surgery (P<0.0001), as well as at day 1 (P = 0.0011), day 2 (P = 0.0079), and day
3 (P = 0.0020). After 5 months, no statistically significant difference was
found. CONCLUSIONS: After phacoemulsification and foldable IOL implantation,
postoperative alteration in the blood-aqueous barrier was statistically
significantly lower with the clear corneal tunnel incision group compared with
the sclerocorneal incision group, in the first 3 days postoperatively.
PMID- 10690819
TI - Subjective visual experience during phacoemulsification and intraocular lens
implantation under topical anesthesia.
AB - OBJECTIVE: The aim of this study was to investigate the subjective visual
experience of patients during phacoemulsification and intraocular lens (IOL)
implantation under topical anesthesia. DESIGN: Postoperative questionnaire
survey. PARTICIPANTS: The study cohort consisted of 52 patients with cataracts.
There were 18 male (34.6%) and 34 female (65.4%) patients. Their mean (+/- SD)
age was 67.5 (+/-10.8) years. INTERVENTION: The patients underwent routine
phacoemulsification and IOL implantation under topical anesthesia. MAIN OUTCOME
MEASURES: The patients were interviewed on the same day after their operation
regarding their visual experience in the operated eye during surgery. RESULTS:
All patients (100%) reported that they could see at least some light during the
surgery. Some patients reported they could also see one or more colors (50
patients, 96.2%), movements (32 patients, 61.5%), flashes (24 patients, 46.2%),
the surgeon's fingers/hands (13 patients, 25%), instruments (12 patients, 23.1%),
and/or the surgeon (4 patients, 7.7%). The colors seen included red (24 patients,
46.2%), yellow (23 patients, 44.2%), blue (12 patients, 23.1%), green (7
patients, 13.5%), and orange (6 patients, 11.5%). Eight patients (15.4%) saw the
spectrum of colors similar to that of the rainbow. Twenty-four patients (46.2%)
reported that the brightness of light changed during the course of the operation.
Eight patients (15.4%) found their visual experience frightening. There was no
statistically significant association between those who found the visual
experience frightening and the sex or age of the patient, a history of cataract
operation in the fellow eye, the type of visual sensation experienced, or the
presence of coexisting ocular pathology. CONCLUSION: All patients undergoing
phacoemulsification under topical anesthesia experience a variety of visual
sensations that may be frightening in a small proportion of patients.
PMID- 10690820
TI - Photorefractive keratectomy versus laser in situ keratomileusis: a control
matched study.
AB - OBJECTIVE: Photorefractive keratectomy (PRK) and laser in situ keratomileusis
(LASIK) outcomes were compared at 1, 3, 6, and 12 months after surgery. DESIGN:
Retrospective, nonrandomized, comparative study. PARTICIPANTS: One hundred seven
LASIK-treated eyes (58 patients) and 107 PRK-treated eyes (91 patients) having
myopia between -1 and -9.50 diopters (D). All LASIK-treated eyes were analyzed
retrospectively and matched with PRK-treated eyes having sphere within +/-0.25 D,
+/-1 D of cylinder, and +/-7 years of age. INTERVENTION: For PRK and LASIK, the
refractive surgery was performed with the slit-scanning excimer laser Nidek EC
5000, (Nidek Co. Tokyo, Japan) MAIN OUTCOME MEASURES: Manifest refraction, best
spectacle and uncorrected Snellen visual acuity, haze, halos, and keratometry
were evaluated before surgery and up to 12 months after surgery. RESULTS: Seventy
percent of eyes were evaluated at the 12-month postoperative exam. Of these eyes,
83% of LASIK cases and 86% of PRK cases had uncorrected visual acuities of 20/20
or better. Refractions within +/-0.5 D represented 78% of the LASIK eyes and 83%
of the PRK eyes at that follow-up. Patients who underwent LASIK reported halos
twice as often as patients who underwent PRK using a subjective scale. The odds
ratio of high halos for LASIK versus PRK was 3.50 (95% confidence interval, 1.89
6.46; P<0.0001). At 1 month after surgery, 64% of the LASIK eyes were within +/
0.50 D compared with 77% of the PRK eyes. No eye lost 2 Snellen lines of best
corrected visual acuity at 6 or 12 months after surgery. Ten PRK eyes (9.3%) and
three LASIK eyes (2.8%) were retreated. CONCLUSIONS: PRK and LASIK achieved equal
refractive outcomes at all postoperative follow-ups, but LASIK patients were
twice as likely to experience halos.
PMID- 10690821
TI - Incidence of vitreoretinal pathologic conditions within 24 months after laser in
situ keratomileusis.
AB - OBJECTIVE: To report for the first time a case series of vitreoretinal pathologic
conditions after laser in situ keratomileusis (LASIK) and to determine its
incidence. DESIGN: Case series. PARTICIPANTS: Five refractive surgeons and 29,916
eyes that underwent surgical correction of ametropia (83.2% were myopic) ranging
from -0.75 to -29.00 diopters (D; mean: -6.19 D) and from +1.00 to +6.00 D (mean:
+3.23 D) participated in this retrospective study. MAIN OUTCOME MEASURES:
Vitreoretinal complications after LASIK. RESULTS: The clinical findings of 20
eyes (17 patients) with LASIK-related vitreoretinal pathologic conditions are
presented. Fourteen eyes experienced rhegmatogenous retinal detachments (RDs).
Two eyes experienced corneoscleral perforations with the surgical microkeratome
when a corneal flap was being performed (one experienced a vitreous hemorrhage
and the other later experienced an RD). In four eyes, retinal tears without RDs
were found. In one eye, a juxtafoveal choroidal neovascular membrane (CNVM)
developed. Retinal tears were treated with argon laser retinopexy or cryotherapy.
Corneoscleral perforations were sutured, and the RD was managed with vitrectomy.
The remaining RDs were managed with vitrectomy, cryoretinopexy, scleral buckling,
argon laser retinopexy, or pneumatic retinopexy techniques. The CNVM was
surgically removed. The incidence of vitreoretinal pathologic conditions
determined in our study was 0.06%. CONCLUSIONS: Serious complications after LASIK
are infrequent. Vitreoretinal pathologic conditions, if managed promptly, will
still result in good vision. It is very important to inform patients that LASIK
only corrects the refractive aspect of myopia. Complications of the myopic eye
will persist.
PMID- 10690822
TI - A randomized trial of low-dose, topical mitomycin-C in the treatment of severe
vernal keratoconjunctivitis.
AB - OBJECTIVE: To evaluate the efficacy and safety of low-dose, topical mitomycin-C
in patients with severe vernal keratoconjunctivitis. DESIGN: Placebo-controlled,
double-masked, randomized clinical trial. PARTICIPANTS: Twenty-six patients with
vernal keratoconjunctivitis refractory to combination of steroid and mast-cell
stabilizer treatment. INTERVENTION: Patients were randomly assigned (2:1) to
treatment with topical 0.01% mitomycin-C eye drops (n = 17) or placebo (n = 9)
three times daily for 2 weeks. MAIN OUTCOME MEASURES: Symptoms (itching, tearing,
photophobia, ropy mucous discharge, foreign body sensation) and signs
(conjunctival hyperemia, epithelial punctate keratitis, Trantas' dots, limbal
edema, and palpebral conjunctival giant papillae) of vernal keratoconjunctivitis
recorded on the day of enrollment and at the end of the treatment period.
RESULTS: There was a statistically significant decrease in ropy mucous discharge,
photophobia, conjunctival hyperemia, and limbal edema in the mitomycin-C treated
group compared with the placebo group at the end of the 2-week treatment period.
In addition, none of the 17 treated patients, but all 9 of the placebo patients,
required medication during the 4-week posttreatment follow-up period. No adverse
effects of treatment with mitomycin-C were observed. CONCLUSIONS: Short-term, low
dose, topical mitomycin-C may be considered in the acute exacerbation periods of
patients with severe vernal keratoconjunctivitis refractory to conventional
treatment.
PMID- 10690823
TI - Limbal-conjunctival autograft transplantation for the treatment of recurrent
pterygium.
AB - OBJECTIVE: Different investigators have recently emphasized the importance of the
limbus and its stem cells in the pathogenesis of the pterygium. In this article
we examine the usefulness of limbal-conjunctival autograft transplantation for
the treatment of advanced recurrent pterygium. DESIGN: Prospective noncomparative
case series. PARTICIPANTS: Seven patients with advanced recurrent pterygium. All
had previously been treated a minimum of two times by simple excision (two of
them with intraoperative mitomycin C). INTERVENTION: Limbal-conjunctival
autograft transplantation after pterygium excision was performed in all cases.
MAIN OUTCOME MEASURES: Pterygium recurrences and complications with a minimal
follow-up period of 14 months. RESULTS: There were no recurrences of pterygial
growth beyond the limbal edge. In addition, no significant complications were
noted. Only one case of limited pseudopterygium in the donor site and one case of
graft retraction were recorded. No further surgical interventions were needed in
any case. CONCLUSIONS: Limbal-conjunctival autograft transplantation is a
promising technique for the treatment of advanced recurrent pterygium.
PMID- 10690824
TI - Conjunctival vasculature in the assessment of anemia.
AB - OBJECTIVE: To assess the correlation of the bulbar conjunctival blood column
(BCBC) with anemia. DESIGN: A prospective, randomized, masked, two observer case
series. PARTICIPANTS: Inpatients on hospital wards; outpatients in both the
Hematology-Oncology and Ophthalmology Clinics. METHODS: Observations of the
palpebral conjunctival hue (PCH) and BCBC by two observers masked to the
patient's diagnosis, laboratory test results, and other's observations. The PCH
and BCBC were correlated by slit-lamp examination with serum hemoglobin values.
Different threshold levels for anemia were defined as hemoglobin <10, <11, and
<12 mg/dl. MAIN OUTCOME MEASURES: The parameters included determination of (1)
the conjunctival hue, assessed as pink or pale and (2) the bulbar conjunctival
blood column, assessed as full (normal), granular, or discontinuous. These data
were compared against the patient's hemoglobin level. RESULTS: Mean hemoglobin
was 11.0+/-2.2 mg/dl. Sensitivity of the BCBC and PCH for anemia was 83%-94% and
38%, respectively, regardless of the definition of anemia. Specificity of BCBC
improved with increasing hemoglobin threshold levels for anemia: 56% (hemoglobin
<10 mg/dl) to 73% (hemoglobin <12 mg/dl); specificity for PCH ranged from 82% to
94%. The BCBC was significantly (P<0.03) associated with anemia for hemoglobin
<11 mg/dl for both observers (logistic regression, Spearman correlation). There
was a significant (P<0.05) association of PCH with anemia only for hemoglobin <10
mg/dl with logistic regression (one observer only) and with Spearman correlation
(both observers). CONCLUSIONS: The BCBC is significantly associated with anemia,
with higher sensitivity and only slightly less specificity than PCH.
PMID- 10690825
TI - Oral acyclovir for the management of herpes simplex virus keratitis in children.
AB - PURPOSE: To evaluate the use of oral acyclovir in pediatric patients with herpes
simplex virus (HSV) keratitis. DESIGN: Retrospective noncomparative case series.
PARTICIPANTS: Seven pediatric patients seen at the University of Minnesota
Hospitals and Clinics with herpes simplex virus (HSV) infectious epithelial
keratitis between January 1992 and October 1998. Patient ages ranged from 6 weeks
to 5 years at time of presentation with a median of 1.7 and mean of 1.9 years.
INTERVENTION: All patients received oral acyclovir; six of seven patients also
received topical antiviral medications. Three of seven patients had topical
antiviral therapy fail before being placed on oral acyclovir, and the remaining
four patients were placed on oral acyclovir primarily. RESULTS: All patients
showed resolution of HSV infectious epithelial keratitis. Three patients have
been maintained on prophylactic dosage of oral acyclovir because of recurrent
disease or because they have been chronically treated with topical
corticosteroids for immune stromal keratitis. All patients tolerated acyclovir
well, and there were no adverse reactions. CONCLUSIONS: Oral acyclovir is useful
in treating HSV infectious epithelial keratitis in pediatric patients. It is
beneficial in treating infectious epithelial keratitis and prophylactically
either while treating with topical corticosteroids for immune stromal keratitis
or for preventing recurrent infectious epithelial keratitis.
PMID- 10690826
TI - Comparison of the efficacy of betaxolol-brinzolamide and timolol-dorzolamide as
suppressors of aqueous humor flow in human subjects.
AB - OBJECTIVE: To compare the efficacy of combinations of betaxolol-brinzolamide and
timolol-dorzolamide as suppressors of aqueous humor flow and ocular hypotensive
agents. DESIGN: Placebo-controlled, masked comparison of the two drug
combinations. PARTICIPANTS: Twenty-five normal human volunteers with the fellow
eye serving as control. METHODS OR TESTING: Fluorophotometric measurement of
aqueous humor flow and pneumatonometric measurement of intraocular pressure. MAIN
OUTCOME MEASURES: Aqueous humor flow and intraocular pressure. RESULTS: The
betaxolol-brinzolamide combination lowered aqueous flow 39% to 44%, and the
timololdorzolamide combination lowered aqueous flow 51%. The betaxolol
brinzolamide combination lowered intraocular pressure 14% to 19%, and the timolol
dorzolamide combination lowered it 18% to 24%. CONCLUSIONS: Both drug
combinations were effective; the timolol-dorzolamide combination appeared to be
the more effective of the two after short-term exposure (24 hours).
PMID- 10690827
TI - Frequency doubling technique in patients with ocular hypertension and glaucoma:
correlation with octopus perimeter indices.
AB - PURPOSE: To ascertain whether frequency doubling technique (FDT) (Welch-Allyn,
Skaneateles, NY; Zeiss-Humphrey, San Leandro, CA) indices provide results
comparable with those of standard Octopus threshold perimeters (Interzeag AG, CH
8952 Schlieren, CH) in patients with glaucoma and in patients suspected of having
ocular hypertension, glaucoma, or both. DESIGN: A comparative, consecutive, case
series. PARTICIPANTS: Thirty-nine glaucomatous patients and 41 patients with
ocular hypertension or suspected glaucoma were recruited consecutively. METHODS:
The visual field of the study participants were assessed by FDT program C-20 full
threshold and Octopus program dG1X. Only one eye of each participant was selected
randomly. Pearson's r correlation coefficient was calculated among the FDT and
Octopus indices. MAIN OUTCOME MEASURES: Using Octopus perimeter, mean defect
(MD), mean sensitivity (MS), loss variance (LV), and corrected loss variance
(CLV) were calculated and used for correlation. For the FDT, mean deviation (FDT
MD) and pattern standard deviation (FDT-PSD) were calculated and used for
correlation. Also, the time required to perform the visual field test was
considered. RESULTS: In the entire population, a statistically significant
correlation (Pearson's r, P<0.001) was found between FDT-MD and both MS (0.77)
and MD (-0.80) and between FDT-PSD and both LV (0.50) and CLV (0.45). When the
glaucoma group was considered alone, similar significant correlation was found
between the indices. In the suspected ocular hypertension and glaucoma suspect
group, no significant correlation was found. A significant (P<0.001) difference
was found between FDT and Octopus for the time needed to perform the visual field
test. CONCLUSIONS: This new technique could be used both to screen populations
and to observe glaucomatous visual field progression in early and moderate
stages. The FDT is a faster way to analyze the visual field and captures
threshold values for each point, but it is important to remember that this is a
new technique and its limits are still unknown.
PMID- 10690828
TI - Outcome of trabeculectomy with mitomycin-C in the iridocorneal endothelial
syndrome.
AB - PURPOSE: Eyes with iridocorneal endothelial (ICE) syndrome have a high risk of
failure in glaucoma filtering surgery failing. We investigated the efficacy of
trabeculectomy with intraoperative mitomycin-C application in these patients.
DESIGN: Retrospective nonrandomized comparative trial with historical controls.
PARTICIPANTS AND CONTROLS: Ten patients with unilateral iridocorneal endothelial
(ICE) syndrome were reviewed. Their intraocular pressures could not be controlled
medically. In five eyes, this was the primary surgery performed. Five of the
patients had undergone prior intraocular pressure-(IOP) lowering surgery that had
failed at the time enrolled. Results were compared with previously published case
series of similar patients treated with trabeculectomy alone or trabeculectomy
and subconjunctival 5-fluorouracil injections. INTERVENTION: Intervention
consisted of trabeculectomy with a limbus-based conjunctival flap and mitomycin-C
application. The dosage of mitomycin-C was 0.4 mg/ml for 1 to 4 minutes (mean,
1.9 min). MAIN OUTCOME MEASURES: Adequate control of IOP (without medication
lower than 21 mm Hg). RESULTS: In eight eyes the IOP remained well controlled
(mean IOP, 12.1 mm Hg) over the entire length of available of follow-up (mean,
14.9 months). Two eyes required implantation of an aqueous tube shunt at 4 and 11
months, respectively, after trabeculectomy with mitomycin-C. One eye experienced
visual loss of 3 Snellen lines because of hypotony maculopathy. CONCLUSIONS:
Trabeculectomy with mitomycin-C application offers a reasonable intermediate-term
success rate in ICE patients, who are otherwise at high risk for failure of
filtering surgery.
PMID- 10690829
TI - Simultaneous subconjunctival and subscleral mitomycin-C application in
trabeculectomy.
AB - OBJECTIVE: To establish the efficacy and safety of simultaneous subconjunctival
and subscleral application of mitomycin-C in trabeculectomy. DESIGN: A
prospective, randomized study. PARTICIPANTS: Sixty-eight patients (68 eyes) with
refractory glaucomas were included in the study. INTERVENTION: Eyes were randomly
assigned to receive intraoperative mitomycin-C (0.3 mg/ml) applied under the
conjunctival flap (group 1), scleral flap (group 2), or under both flaps (group
3). MAIN OUTCOME MEASURES: Mean intraocular pressure (IOP), postoperative
medications, visual acuity, filtering bleb appearance, and complications.
RESULTS: There was a significant difference in IOP at 6, 9, and 12 months after
surgery among the three groups (P = 0.021, 0.026, and 0.033, respectively ANOVA).
At 12 months, the mean IOP in group 3 was 9.8+/-3.7 mm Hg compared with 13.4+/
5.5 mm Hg in group 2. (P = 0.015) and 12.4+/-4.4 mm Hg in group 1 (P = 0.039).
Success rate (21 mm Hg or less), number of antiglaucoma medications, and
complications showed no statistical significant difference between the three
groups at each postoperative visit. CONCLUSIONS: Mitomycin-C applied under the
scleral flap may have an additional beneficial effect when combined with
simultaneous subconjunctival exposure.
PMID- 10690830
TI - Determinants of glaucoma awareness in a general eye clinic.
AB - PURPOSE: Heightened public awareness about glaucoma may increase the chance of
identifying undetected cases. To ascertain determinants of glaucoma awareness, we
surveyed a population visiting a general eye clinic. DESIGN: Cross-sectional
study. PARTICIPANTS: 1197 general eye clinic patients and their companions.
METHODS: We designed and administered a questionnaire about glaucoma to general
eye clinic patients and their companions. We created multivariate logistic
regression models to ascertain the effect of demographic and clinical features on
the likelihood of being unaware of glaucoma. MAIN OUTCOME MEASURES: Adjusted odds
ratio (OR) with 95% confidence intervals of survey attributes associated with
self-perceived unfamiliarity with glaucoma. RESULTS: Glaucoma awareness overall
(72%) approached that found in the subgroup self-reporting a diagnosis of
glaucoma (80%). Survey attributes associated with an increased likelihood of
being unaware of glaucoma were African American race (OR = 1.69 [1.28-2.20],
Hispanic ethnicity (OR = 2.13 [1.46-3.02]), and less than a college education (OR
= 1.67 [1.37-2.05]). Age was also a determinant of glaucoma awareness (for ages
50-64 years, OR = 0.60 [0.44-0.80] and for ages 65-79 years, OR = 0.56 [0.41
0.75] compared with ages less than 35 years). A self-report of glaucoma was not a
determinant of glaucoma awareness (OR = 0.63 [0.33-1.17]), although there was a
trend toward enhanced glaucoma awareness in this subgroup. Finally, respondents
with a history of employment in the health field (OR = 0.63 [0.49-0.82]) myopia
(OR = 0.68 [0.56-0.82]), glaucoma in a first-degree relative (OR = 0.68 [0.53
0.87]), and respondents who reported having a dilated eye examination (OR = 0.53
[0.42-0.66]) were less likely to be unaware of glaucoma than those who did not
have these attributes. CONCLUSIONS: Although glaucoma awareness in this
population was high, Hispanics, African Americans, and those with less than a
college education were more likely to be unfamiliar with the disease.
Interestingly, a self-report of having glaucoma was not a statistically
significant determinant of glaucoma awareness.
PMID- 10690831
TI - Outcomes of sequential tube shunts in complicated glaucoma.
AB - OBJECTIVE: To evaluate intraocular pressure (IOP) control, change in visual
acuity, and complications in eyes that have undergone a second glaucoma tube
shunt procedure. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS:
Twenty-two eyes of 22 patients that have undergone sequential tube implants for
management of glaucoma. METHODS: Parameters analyzed included IOP, visual acuity,
and number of hypotensive agent before each shunt procedure and at last follow-up
visit. The overall IOP lowering effect attributable to each tube shunt was
calculated. Any ocular complications after the second tube shunt were recorded.
Success was defined as an IOP between 6 and 21 mm Hg and a 20% reduction in IOP
from the second tube shunt procedure. Qualified successes met one of these two
requirements at the last follow-up visit. Total failures did not meet any of the
above criteria, required additional surgical intervention to lower IOP, or both.
MAIN OUTCOME MEASURES: Intraocular pressure control, visual acuity preservation,
and complications. RESULTS: At the last follow-up visit, the average percent
reduction in IOP from both tube shunt procedures was 42+/-21%. The average
percent IOP reduction from the second tube shunt was 33+/-17%. Eleven (50%)
patients met the criteria for success, 8 (36.4%) patients were qualified
successes, and 3 (13.6%) were failures. The median number of hypotensive agents
decreased from two to one. Ten patients experienced new or worse pseudophakic
bullous keratopathy after the second tube shunt, six of whom underwent
penetrating keratoplasty. Thirteen (59%) patients maintained visual acuity within
one line of their second tube shunt pre-operative Snellen visual acuity. Seven
(32%) patients lost more than 2 lines, and one patient lost light perception.
CONCLUSIONS: Although corneal morbidity is a common complication, a second tube
shunt does not cause higher-than-expected rates of other complications associated
with tube shunt surgery. Eyes that undergo a second tube shunt procedure can
achieve pressure control, require fewer hypotensive agents, and may maintain
stable visual acuity.
PMID- 10690832
TI - Prevention of cellulitis after open lacrimal surgery: a prospective study of
three methods.
AB - OBJECTIVE: Soft-tissue cellulitis after open lacrimal surgery, almost exclusively
caused by infection, is associated with a reduced surgical success rate,
inconvenience for the patient, and may predispose to secondary hemorrhage.
Although postoperative oral antibiotics have been shown to significantly reduce
the infection rate, this investigation was designed to compare this regimen with
two other methods for the prevention of postoperative infection. DESIGN: A
prospective nonrandomized comparative trial of three methods for prevention of
postoperative infection. PARTICIPANTS: Patients, recruited over a 16-month period
from the Lacrimal Clinic at Moorfields Eye Hospital, who required primary open
dacryocystorhinostomy. METHOD: Two hundred and sixty-five patients were assigned,
on the basis of hospital number, to one of three groups: to receive either an
intravenous broad-spectrum antibiotic immediately after induction of anesthesia
(group 1), intraoperative lavage of the rhinostomy site just after suture of the
anterior mucosal flaps (group 2), or a postoperative course of oral antibiotics
(group 3). OUTCOME MEASURES: Cellulitis was considered to be present when there
was marked tenderness along a swollen and erythematous incision line, evidence of
frank pus from the suture line, or late postoperative hemorrhage occurred.
Patients were reviewed within a week of surgery. RESULTS: Signs of infective
cellulitis occurred in 1 of 127 (0.8%) cases in group 1, 7 of 41 (18%) cases in
group 2, and 2 of 127 (1.5%) cases in group 3. Whereas the infection rate in
group 2 was significantly greater than that in group 1 (P << 0.001) or group 3
(P<0.001), no significant difference was found between that in groups 1 and 3
(0.75>P>0.5; chi-square test with Yates' correction). CONCLUSION: Compared with
intraoperative saline lavage, intraoperative or postoperative broad-spectrum
antibiotics have comparable efficacy in the prevention of postoperative soft
tissue cellulitis after open lacrimal surgery. Intraoperative administration of
antibiotics has the advantages of compliance and economics.
PMID- 10690833
TI - The surgical management of hypotony.
AB - OBJECTIVE: To study the effect of dissecting epiciliary proliferative tissue in
eyes that are hypotonous. DESIGN: Retrospective noncomparative case series.
PARTICIPANTS: Eight patients (nine eyes). MAIN OUTCOME MEASURES: Normalization of
intraocular pressure and preservation of vision. METHODS: A chart review was
conducted to locate all surgical procedures performed primarily for hypotony.
Nine procedures on eight eyes of eight patients seen in the vitreoretinal service
of the Wilmer Ophthalmological Institute were identified and included in this
study. Six of these eyes had undergone prior surgery for retinal detachment in
association with proliferative vitreoretinopathy, one had undergone surgery for
retinal detachment in the setting of a ruptured globe, and two had undergone
cataract surgery and coined the diagnoses of uveitis (juvenile rheumatoid
arthritis and sarcoid). Dissection and removal of the epiciliary proliferative
tissue and lens capsule was undertaken by two surgeons (EdJ and MSH) using either
a pars plana or limbal approach. The main outcome measures were intraocular
pressure (IOP) and visual acuity after an average follow-up of 26 months (range,
9-48 months). RESULTS: In the immediate postoperative period, all patients showed
an increase in IOP (average increase of 6.3 mm Hg; range, 3-14 mmHg). This
average increase in IOP decreased to 5.2 mmHg at 6 months and 4.2 mm Hg at 12 or
more months of follow-up. The rate of the IOP decrease appeared to lessen with
time, suggesting long-term stabilization. Visual acuity remained stable in all
patients, although the final level of vision was low. CONCLUSIONS: Surgical
intervention for hypotony with greater than 1 year follow-up continues to show
elevated IOP in some patients, despite the fact that the large initial increase
in IOP is not sustained. No eye had phthisis develop or became painful. However,
no eye had marked improvement in vision. Further study is needed to uncover the
main contributing factors that result in hypotony before IOP can be maintained
for prolonged periods in more hypotonous eyes and before these eyes can regain
more vision.
PMID- 10690834
TI - A comparison of dense versus less dense diode laser photocoagulation patterns for
threshold retinopathy of prematurity.
AB - OBJECTIVE: To determine if the density of diode laser photocoagulation for the
treatment of zone 1 or zone 2 threshold retinopathy of prematurity (ROP) affects
the rate of progression of the disease. DESIGN: Retrospective, nonrandomized,
comparative trial (n = 12) and prospective, randomized, clinical trial (n = 46).
PARTICIPANTS: Two surgeons treated a total of 107 eyes from 58 patients with zone
1 or zone 2 threshold ROP within 72 hours of diagnosis. The two consecutive
groups of patients were treated with two different diode laser photocoagulation
patterns between May 1995 and October 1997 and were observed for at least 3
months. INTERVENTION: All patients underwent diode laser photocoagulation of the
peripheral avascular retina extending from the ridge of extraretinal
proliferation to the ora serrata. One cohort received a near confluent laser
pattern, whereas the second cohort received a pattern of laser spots placed 1 to
1.5 burn widths apart. MAIN OUTCOME MEASURES: Anatomic outcome, rate of
progression to stage 4 or 5 retinopathy of prematurity, postoperative
complications, and timing and frequency of retreatment. RESULTS: For analysis,
the retrospective and randomized outcome data were grouped. The rate of
progression in the near confluent laser treatment group was 3.6% overall, 0% of
zone 1 eyes, and 3.8% of zone 2 eyes. The rate of progression in the less dense
treatment group was 29% overall, 44% of zone 1 eyes, and 21 % of zone 2 eyes.
Mean time to retreatment was 16 days in cohort 1 and 24 days in cohort 2.
CONCLUSIONS: A dense pattern of diode laser treatment for threshold ROP and
prompt retreatment for residual plus disease significantly reduce the rate of
progression in eyes with zone 2 disease (P = 0.02) and may be beneficial in eyes
with zone 1 disease.
PMID- 10690835
TI - Laser photocoagulation spot-size errors stemming from the refractive state of the
surgeon's eye.
AB - PURPOSE: Meaningful errors in photocoagulation spot size may result from several
factors. In this article we discuss one major factor, namely, fluctuations in the
surgeon's accommodative state, coupled with an inaccurate setting of the slit
lamp oculars. DESIGN: Experimental study. METHODS: We analyzed and tested the
optics of slit-lamp mounted lasers. Varying the ocular setting is correlated with
measurements of the actual spot size obtained with each system. MAIN OUTCOME
MEASURE: The spot size obtained. RESULTS: Three distinct, but related, phenomena
that may lead to spot size errors are defined: (1) focusing the laser spot as
opposed to focusing the retinal image; (2) instrument misalignment; (3)
inadvertent accommodation. CONCLUSION: The ocular setting must be meticulously
calibrated to produce a true spot-sized burn. At the 50 microm setting, each
diopter of induced accommodation, or erroneous ocular setting, almost doubles the
actual spot size obtained. With large (500 microm) spot size settings, the
defocused delivery system is more prone to spot-size errors in contrast with
parfocal lasers.
PMID- 10690836
TI - Peripapillary chorioretinal atrophy: Bruch's membrane changes and photoreceptor
loss.
AB - PURPOSE: To determine relationships among Bruch's membrane ultrastructure,
photoreceptor degeneration, and choriocapillaris atrophy with respect to zones of
retinal pigment epithelium (RPE) degeneration and atrophy adjacent to the optic
nerve head, as a function of age. DESIGN: Human tissue study using
clinicopathologic correlation. TISSUES: Eyes from patients 36 to 93 years of age
lacking clinical evidence of glaucoma, optic nerve abnormalities, severe myopia,
age-related macular degeneration, or other macular or peripapillary chorioretinal
pathologic condition. METHODS: Sections through the retina-choroid complex at the
temporal aspect of the optic nerve head were used for light microscopic
histopathologic analysis (n = 17), electron microscopy (n = 9), carbonic
anhydrase histochemical analysis (n = 7), and lipid histochemical analysis (n =
22). Retinal whole mounts were used for photoreceptor counts (n = 5). MAIN
OUTCOME MEASURES: We determined the width of RPE degeneration and atrophy, the
number of eyes with abnormalities of inner Bruch's membrane, and the number of
rod and cone photoreceptors within 1 mm of the disc margin. We determined whether
Bruch's membrane changes, photoreceptor degeneration, and choriocapillaris
atrophy were associated with RPE degeneration and atrophy. RESULTS: All eyes had
peripapillary RPE atrophy, degeneration, or both. The zone of RPE atrophy widened
significantly after age 75. Thickening of inner Bruch's membrane and
abnormalities of the RPE basal lamina were associated with degenerating and
atrophic RPE in all eyes. The RPE basal lamina was narrow, reduplicated, or
thickened as a basal laminar deposit. All eyes exhibited degeneration and loss of
rods but not cones at the peripapillary termination of Bruch's membrane.
Diminution of choriocapillaris coverage of Bruch's membrane was associated with
RPE degeneration. Complete loss of the choriocapillaris was associated with RPE
atrophy. CONCLUSIONS: Our results suggest that peripapillary chorioretinal
atrophy is an age-related degeneration of the RPE-Bruch's membrane complex that
resembles that found in the macula and periphery of normal eyes.
PMID- 10690837
TI - Circumscribed choroidal hemangioma: characteristic features with indocyanine
green videoangiography.
AB - OBJECTIVE: To determine the characteristic features of indocyanine green
videoangiography (ICG-V) of circumscribed choroidal hemangioma. DESIGN:
Prospective, observational case series. PARTICIPANTS: Twenty-five eyes of 25
consecutive patients with circumscribed choroidal hemangioma. INTERVENTION:
Indocyanine green videoangiography and intravenous fluorescein angiography (IVFA)
were prospectively performed and reviewed. The specific features on ICG-V were
compared with features of IVFA. MAIN OUTCOME MEASURES: The behavior of
circumscribed choroidal hemangioma cases was observed with ICG-V and IVFA.
RESULTS: On ICG-V, earliest hyperfluorescence of circumscribed choroidal
hemangioma was achieved at a mean of 27.6 seconds (range, 13-62 seconds), whereas
maximum hyperfluorescence occurred at 222 seconds (range, 33-707 seconds). In the
late frames, all eyes demonstrated a relative decrease in fluorescence, including
18 eyes (72%) that demonstrated "washout" of the dye. Other findings on ICG-V
included intrinsic vessels in 19 eyes (76%), a late hyperfluorescent rim in 19
eyes (76%), and late frame hot spots in 14 eyes (56%). On IVFA, the earliest
hyperfluorescence was achieved at a mean of 24 seconds (range, 10-66 seconds),
whereas maximum hyperfluorescence occurred at a mean of 76.3 seconds (range, 21
720 seconds). Increasing hyperfluorescence in the late frames was found in all
cases. Other findings included intrinsic vessels in 12 eyes (48%) and hot spots
in the late frames in 9 eyes (36%). CONCLUSIONS: Circumscribed choroidal
hemangioma have specific characteristics on ICG-V that are not visualized with
IVFA. We believe that ICG-V may become an important noninvasive tool for the
diagnosis of choroidal hemangioma.
PMID- 10690838
TI - Transpupillary thermotherapy for circumscribed choroidal hemangiomas.
AB - PURPOSE: Various treatments have been described for circumscribed choroidal
hemangiomas. We present our results with transpupillary thermotherapy (TTT) with
infrared laser that indicate that the therapy is a new, effective treatment for
this pathologic condition. DESIGN: Noncomparative, prospective, interventional
case series. PARTICIPANTS: The treatment and follow-up of eight eyes of eight
patients with circumscribed choroidal hemangiomas are presented. Each case was
treated when the visual acuity (VA) decreased because of serous retinal
detachment that affected the macula. METHODS: Infrared diode laser was used at
810 nm and power between 800 and 1200 mW with a beam diameter of 2 or 3 mm
depending on the diameter of the hemangioma, with 3 to 6 minutes of exposure
time. MAIN OUTCOME MEASURES: The final VA, the presence of serous subretinal
fluid, funduscopic appearance of the tumor, and the degree of hyperfluorescence
observed during fluorescein angiography were the main parameters. RESULTS: In all
eight cases, total reabsorption of the serous retinal detachment was achieved
after one or repeated applications of TTT. Mild choroidal atrophy and minimal
hyperpigmentation of the retinal pigment epithelium were observed in the treated
eyes. CONCLUSIONS: TTT can be considered an acceptable therapeutic option for
choroidal hemangiomas and serous retinal detachment, and we believe that the role
of this therapy will expand in the management of these patients.
PMID- 10690839
TI - Stereotactic radiation therapy for malignant choroidal tumors: preliminary, short
term results.
AB - PURPOSE: To evaluate the role of stereotactic radiation therapy (SRT) in the
treatment of malignant choroidal tumors. DESIGN: Prospective, noncomparative case
series. PARTICIPANTS: Ten patients with unifocal choroidal metastasis (three lung
carcinoma, three breast carcinoma, three colon carcinoma, one cutaneous melanoma)
and five patients with primary choroidal melanoma underwent single-dose or
fractionated SRT. METHODS: Before treatment, computed tomography (CT) scans of
the orbit were obtained with the patient wearing an individualized immobilization
mask. An integrated macro-CCD-camera system viewed the eye for detection of
movements. Three-dimensional computer-based treatment planning was carried out.
Dose distribution was calculated and displayed in isodose lines on the CT data
set. For SRT, a dedicated stereotactic linear accelerator (6 MV) was used. Total
doses for choroidal metastases were 12 to 20 Gy in a single dose or 30 Gy over 10
days (3 Gy each session), and total doses for choroidal melanoma were 50 Gy over
5 or 10 days (10 or 5 Gy each session). MAIN OUTCOME MEASURES: Best corrected
visual acuity (ETDRS-chart), biomicroscopy, ultrasound examination, fluorescein
angiography, and magnetic resonance imaging (MRI) were performed before treatment
and at regular intervals after completion of SRT. RESULTS: During a follow-up
period from 1 to 34 months (median, 6.5 months), local tumor control was achieved
in all eyes. A decrease in tumor size on ultrasonography or MRI was noted in
eight patients. No persistent side effects were observed during follow-up.
CONCLUSIONS: Stereotactic radiation therapy allows steep dose gradients outside
the target volume by minimizing the field of exposure. Thus only low radiation
doses affect surrounding radiosensitive ocular structures. Our initial findings
suggest that this technique may be effective in controlling tumor growth. Further
studies are needed to compare treatment efficacy and safety with conventional
treatment methods.
PMID- 10690840
TI - Determination of surgeon's absorbed dose in iodine 125 and ruthenium 106
ophthalmic plaque surgery.
AB - OBJECTIVE: Validation of dosimetry and exposition time to an ophthalmic surgeon
during radioactive plaque operations. DESIGN: Experimental study in which
videotaped operations and dosimetric measurements were used to model dosimetry.
METHODS: We used thermoluminescence detectors for high sensitivity readings in
radiation fields. Typical intersurgical mobility was videotaped and distances to
the plaque was evaluated. MAIN OUTCOME MEASURE: Estimated radiation received by
surgeons. RESULTS: All simulated plaque operations have a maximum dose rate of 6
mGy per minute (value in the inner eyeball). Mean dose rate is 2 mGy per minute
(average of approximately all measurements). The surgeon's fingers receive a dose
from 2 to 6 mSv from plaque operation. CONCLUSIONS: Results suggest that
radioactive plaque operations are safe for the surgeon but that the time for
plaque handling should be minimized. A surgeon should not exceed 100 to 200
operations per year.
PMID- 10690841
TI - Endothelial cell loss in irradiated optic nerves.
AB - OBJECTIVE: Radiation optic neuropathy usually occurs months to years after
exposure of the anterior visual pathways to ionizing radiation. It is
characterized by high signal on gadolinium-enhanced T1-weighted magnetic
resonance imaging. Radiation-induced endothelial cell damage resulting in blood
nerve barrier breakdown is hypothesized to produce this pattern, but histologic
evidence of this in the optic nerve is lacking. We attempted to evaluate the
effect of radiation on endothelial cells in the optic nerve. DESIGN: Case
controlled histologic study. METHODS: We studied the optic nerves of 16
enucleated eyes from patients with uveal melanoma treated with proton beam
irradiation, 6 from normal eyes and 5 from eyes with unirradiated uveal
melanomas. Binding of Ulex europaeus agglutinin I (UEA-I) lectin was used to
identify endothelial cells in single paraffin sections. Transverse and
longitudinal sections of vessels were counted in masked fashion. RESULTS: There
were 49.4+/-6.9 transversely sectioned endothelial cells per millimeter of nerve
in 6 optic nerves exposed to 0 to 1000 cGyE ("low-dose") compared with 17.3+/-5.3
in 10 nerves exposed to 5500 to 7000 cGyE ("high-dose") (P = 0.002).
Longitudinally sectioned vessels stained with UEA-I were separately identified,
with 11.5+/-2.1 in the low-dose group and 5.6+/-1.6 in the high-dose group (P =
0.044). The thickness and staining of the endothelial cell layer appeared greater
in the high-dose group. Endothelial cell counts did not correlate with age,
gender, acuity, or interval after irradiation. CONCLUSIONS: Increased radiation
dosage to the optic nerve correlates with smaller numbers of endothelial cells.
PMID- 10690842
TI - Infrared scanning laser tomography of macular cysts.
AB - OBJECTIVE: To perform three-dimensional, noninvasive, quantitative analysis of
cystoid macular edema and macular cysts using infrared scanning laser tomography
and to correlate findings with visual acuity (VA) as a basis for interventional
studies. DESIGN: Cross-sectional, nonrandomized study. PARTICIPANTS: Seventeen
patients (29-86 years of age) with macular cysts associated with a broad spectrum
of diseases. INTERVENTION: Confocal infrared imaging with scanning laser
tomography with the TopSS (790 nm) (Laser Diagnostic Technologies, San Diego, CA)
with digitized images was used to perform three-dimensional, quantitative
analysis of cysts in the central 5 degrees of the macula. MAIN OUTCOME MEASURES:
Measurements of macular cyst number, area, volume, depth, slope, height of the
surrounding macular elevation, and correlation with VA. RESULTS: Scanning laser
tomography detected macular cysts in all patients. The number per patient ranged
from 1 through 15. Cysts were accompanied by surrounding macular elevation in 16
patients (mean macular height, 216 microm). The area covered by cysts in the
central 5 degrees was 0.087 to 0.969 mm2, and volume was 0.007 to 0.549 mm3.
Visual acuity was significantly poorer in patients with greater cyst area (P =
0.0007), cyst volume (P = 0.0009), macular thickening (P = 0.0002), and cyst
depth (P = 0.0013). Cyst number, average slope, and maximum slope, however, did
not correlate significantly with VA. Grouping of macular cysts according to
macular height and average cyst depth revealed that cysts in a more thickened
retina were significantly deeper, had steeper slopes, and corresponded to worse
VA. Macular height and average cyst depth were highly associated with each other,
suggesting that in eyes with surrounding macular edema, cysts were deeper and may
reflect more widespread tissue destruction. Individual confocal tomographic
images provided additional information. Neither ophthalmoscopy nor fluorescein
angiography delineated features such as retinal folds that suggested vitreous
traction or changes in deeper layers that suggested occult choroidal new vessels.
CONCLUSIONS: Infrared scanning laser tomography is a rapid and noninvasive
imaging method that provides quantitative analysis of macular cysts in addition
to qualitative information not seen clinically. Because poor VA is related to
severe involvement of the central retina, scanning laser tomography could provide
an objective outcome measure for interventional studies.
PMID- 10690843
TI - A longitudinal study of visual function in carriers of X-linked recessive
retinitis pigmentosa.
AB - OBJECTIVE: This study was carried out to evaluate the progression of visual
function impairment in carriers of X-linked recessive retinitis pigmentosa. We
also assessed the relationship between the retinal findings at presentation and
the extent of deterioration. DESIGN: Observational, retrospective, case series.
PARTICIPANTS: Twenty-seven carriers of X-linked recessive retinitis pigmentosa.
METHODS: Each carrier was clinically categorized into one of four grades (grades
0 through 3) depending on the presence or absence of a tapetal-like retinal
reflex and the extent of peripheral pigmentary degeneration. A complete
ophthalmologic examination was performed and data for visual acuity, visual field
area, and electroretinographic measurements were collected on the most recent
visit in both eyes. These were then compared with similar data obtained on their
initial visits. MAIN OUTCOME MEASURES: A comparison of visual function was
carried out between the initial visit and the most recent visit on each carrier.
The visual acuity was measured with Snellen's acuity charts. The visual fields to
targets V-4-e and II-4-e were planimeterized and used for the analysis. The
electroretinographic (ERG) measures used were light-adapted single-flash b-wave
amplitudes and 30-Hz red flicker for cone function, dark-adapted maximal b-wave
amplitudes, and response to a low intensity blue-flash for rod function. RESULTS:
None of the 11 carriers with a tapetal-like reflex only (grade 1) showed any
significant change in visual acuity or fields as compared with 3 of 7 (43%)
carriers with diffuse peripheral pigmentary findings (grade 3) who showed
significant deterioration in visual acuity in at least one eye, and 6 of 7 (86%)
who showed a significant decrease in visual field area with at least one target
size in at least one eye. By comparison, only 1 of 10 carriers with a grade 1
fundus finding demonstrated a significant decrease in maximal dark-adapted ERG
function as compared with 5 of 6 (83%) carriers with grade 3 in response to a
single-flash stimulus and with 4 of 5 (80%) carriers in response to a single
flash blue stimulus. For the single-flash photopic response, none of the 10
carriers with grade 1 showed any significant deterioration, whereas 2 of 4 (50%)
with grade 3 did show such deterioration. The ERG responses for carriers with
grade 2 were in between the extent of decrease in ERG amplitudes of those in
carriers with grades 1 and 3. CONCLUSIONS: In our cohort of X-linked retinitis
pigmentosa carriers, those with only a tapetal-like retinal reflex at
presentation had a better prognosis to retain visual function than those with
peripheral retinal pigmentation. These data are useful in counseling such
carriers as to their visual prognosis.
PMID- 10690844
TI - HSV-1--induced acute retinal necrosis syndrome presenting with severe
inflammatory orbitopathy, proptosis, and optic nerve involvement.
AB - OBJECTIVE: To present a unique case in which orbital inflammation, proptosis, and
optic neuritis were the initial symptoms of acute retinal necrosis (ARN). The
clinical presentation of ARN, as well as the currently recommended diagnostic
procedures and guidelines for medical treatment of ARN, are summarized. DESIGN:
Interventional case report. TESTING: Polymerase chain reaction (PCR) techniques
were made on the vitreous for cytomegalovirus, Epstein-Barr virus, herpes simplex
virus (HSV), varicella zoster virus, and toxoplasmosis. A full laboratory
evaluation was made together with HLA-typing and serologic tests measuring
convalescent titers for HSV and other micro-organisms. Magnetic resonance imaging
scan, computed tomography (CT) scan, and fluorescein angiographic examination
were performed. The patient was treated with acyclovir and oral prednisone. MAIN
OUTCOME MEASURES: The patient was evaluated for initial and final visual acuity
and for degree of proptosis, periocular edema, and vitreitis. RESULTS: The first
symptoms and signs of ARN were eye pain, headache, proptosis, and a swollen optic
nerve on CT scan. Other than increased C-reactive protein, all blood samples were
normal. PCR was positive for HSV-type I in two separate vitreous biopsies. The
patient had the strongly ARN-related specificity HLA-DQ7. CONCLUSIONS: This is
the first report of HSV-induced ARN presenting with inflammatory orbitopathy and
optic neuritis. Polymerase chain reaction for HSV-1 was positive more than 4
weeks after debut of symptoms, which is a new finding. The combination of severe
vitreitis and retinal whitening, with or without proptosis, should alert the
clinician to the possibility of herpes infection and treatment with intravenous
acyclovir started promptly.
PMID- 10690845
TI - Impact of large angle horizontal strabismus on ability to obtain employment.
AB - OBJECTIVE: To determine if large angle esotropia and exotropia could impact a
person's ability to obtain employment. DESIGN: Laboratory experiment.
PARTICIPANTS: Seventy-nine respondents unaware of the purpose of the study.
METHODS: Photographs of two men and two women were digitally altered to create
photographs of the same individual in an orthotropic, esotropic, and exotropic
state. The photographs were then randomly affixed to similarly qualified job
resumes. The 79 study respondents, unaware of the purpose of the study, were
asked to (1) rate each individual applicant on selected job qualification
variables, and (2) rank the applicants against each other in order of hiring
preference. MAIN OUTCOME MEASURES: Individual applicant rating and hiring
preference scores. RESULTS: Women with normal ocular alignment received greater
hiring preference scores than did strabismic women (P = 0.007). No difference in
hiring preference scores was noted between strabismic and non-strabismic male
applicants (P = 0.47). CONCLUSIONS: Large angle horizontal strabismus appeared to
be vocationally significant for female applicants, reducing a strabismic female
applicant's ability to obtain employment. The presence of strabismus did not
appear to influence hiring decisions of male applicants.
PMID- 10690846
TI - Clinical review 111: familial sex reversal: a review.
PMID- 10690847
TI - Therapeutic controversy: prevention and treatment of diabetes in children.
PMID- 10690848
TI - Reversal of hypoglycemia unawareness in a long-term type 1 diabetic patient by
improvement of beta-adrenergic sensitivity after prevention of hypoglycemia.
AB - The purpose of this study was to assess the effect of strict avoidance of
hypoglycemia on beta-adrenergic sensitivity in a type 1 diabetic patient with
hypoglycemia unawareness and a diabetes duration of 55 yr. beta-Adrenergic
sensitivity was determined by an isoproterenol test and was expressed as the
lowest dose of isoproterenol that increases the heart rate by 25 beats/min
(IC25). Plasma epinephrine and symptom responses to hypoglycemia were determined
during a 3-h hypoglycemic (3 mmol/L) clamp. Initially, the patient had a near
normal counterregulatory plasma epinephrine response to hypoglycemia but reduced
beta-adrenergic sensitivity (IC25, 2 microg) compared to 10 hypoglycemia aware,
type 1 diabetic patients (0.65 +/- 0.14 microg) and 10 normal control subjects
(1.13 +/- 0.21 microg). After 1 yr of strict avoidance of blood glucose levels
below 4 mmol/L, the IC25 decreased to 0.25 microg, reflecting improved beta
adrenergic sensitivity. In conclusion, the reduced beta-adrenergic sensitivity in
this patient was probably the reason for hypoglycemia unawareness and was
reversed by strict avoidance of hypoglycemia.
PMID- 10690849
TI - Criteria for cure of acromegaly: a consensus statement.
AB - In February 1999, a workshop was held in Cortina, Italy to develop a consensus
defining the criteria for cure of acromegaly. The workshop was sponsored by the
University of Brescia and hosted by the Italian Society of Endocrinology. Invited
international participants included endocrinologists, neurosurgeons, and
radiotherapists skilled in the management of acromegaly. This statement
summarizes the consensus achieved in these discussions.
PMID- 10690850
TI - Tumor necrosis factor-alpha inhibits leptin production in subcutaneous and
omental adipocytes from morbidly obese humans.
AB - This study was undertaken to examine the regulation of leptin production from
human adipocytes by tumor necrosis factor-alpha (TNFalpha). Adipocytes were
isolated from adipose tissue obtained during bariatric surgical procedures (17
women and 3 men; body mass index, 52.5 +/- 2.4 kg/m2; age, 40 +/- 3 yr) and
cultured in suspension. Leptin release from sc adipocytes was inhibited 17.7 +/-
5.2% (P < 0.01), 21.6 +/- 4.3% (P < 0.005), and 37.1 +/- 7.2% (P < 0.05) by 1,
10, and 100 ng/mL TNFalpha, respectively, after 48 h in culture. At 100 ng/mL,
significant inhibition of leptin release (25.8 +/- 9.7%; P < 0.05) was detected
by 24 h. TNFalpha (10 ng/mL) had no effect on dexamethasone (0.1 micromol/L)
stimulated leptin production in sc adipocytes. In omental adipocytes TNFalpha
inhibited leptin release 21.0 +/- 9.6% and 40.8 +/- 6.3% at 10 and 100 ng/mL by
48 h (P < 0.05). Significant inhibition ofleptin release from omental adipocytes
was observed at 24 h with 100 ng/mL TNFalpha (P < 0.05). Anti-TNFalpha antibody
completely blocked TNFalpha inhibition of leptin release. The ob messenger
ribonucleic acid was significantly reduced (23.6 +/- 5.9%) after 48 h of TNFalpha
(100 ng/mL) treatment (P < 0.025). TNFalpha had no effect on glucose uptake or
lactate production in sc and omental adipocytes. The data suggest that the direct
paracrine effect of adipose-derived TNFalpha is inhibition of leptin production.
PMID- 10690851
TI - A population-based study of chronic autoimmune hypothyroidism in Danish twins.
AB - Hashimoto's thyroiditis (HT), atrophic thyroiditis (AT), and Graves' disease are
autoimmune thyroid diseases in which genetic factors are suspected to play an
important role in disease susceptibility. In a recent population-based twin study
we rendered it probable that a substantial part of the susceptibility to Graves'
disease is attributable to genetic factors. At present there are no population
based twin studies supporting such a genetic influence in the etiology of HT/AT.
To elucidate whether there is a genetic influence in the etiology of HT/AT, we
studied the distribution of HT/AT in a population-based sample of 2945 Danish
female-female twin pairs (5890 individuals) born between 1953 and 1972.
Information on hypothyroidism was obtained from a nationwide questionnaire survey
in 1994. Information from hospitals, out-patient clinics, general practitioners,
and specialists was sought to verify the diagnosis. The overall prevalence of
autoimmune hypothyroidism was 0.41% (24 of 5890). The prevalence did not differ
between monozygotic and dizygotic twins (0.42% and 0.40%, respectively). The
crude proband-wise concordance rates were significantly higher for monozygotic
compared to dizygotic twin pairs: 0.55 (95% confidence interval, 0.23-0.83) vs.
0.0 (95% confidence interval, 0.0-0.25; P = 0.01). All of the healthy cotwins (n
= 15) of twins with clinically overt autoimmune hypothyroidism were biochemically
euthyroid. Overall, regardless of zygosity 53% (8 of 15) of the healthy cotwins
were positive for antithyroid antibodies. The prevalence of autoantibodies among
the monozygotic cotwins was 80% (4 of 5) and 40% (4 of 10) among dizygotic
cotwins (P = 0.36). In conclusion, the higher concordance rate in monozygotic
compared to dizygotic pairs indicates that genetic factors play a role in the
etiology of HT/AT among Caucasian women living in areas with borderline iodine
deficiency. However, the fact that the concordance rate among MZ twins was below
1 suggests that environmental factors also are of etiological importance.
PMID- 10690852
TI - Detection of minimal levels of serum anti-Mullerian hormone during follow-up of
patients with ovarian granulosa cell tumor by means of a highly sensitive enzyme
linked immunosorbent assay.
AB - Granulosa cell tumors (GCT) are ovarian neoplasms that tend to recur and spread
in the pelvis and the abdomen several years after the initial treatment. Anti
Mulerian hormone (AMH) is a reliable serum marker of these tumors. To enhance the
availability and the sensitivity of serum AMH determination, we developed an
ultrasensitive enzyme-linked immunosorbent assay. In this work we compare the
results of serum AMH levels, obtained using the ultrasensitive and the
traditional assays, in 31 patients with ovarian GCT followed up for up to 7 yr.
The ultrasensitive enzyme-linked immunosorbent assay has a significantly higher
sensitivity than the traditional one. This resulted in the detection of low serum
AMH levels, which were undetectable with the traditional assay, in several cases
including one patient in whom a recurrence of a GCT had developed and two
patients in whom the treatment had not been completely successful. These cases
highlight the importance of the availability of a highly sensitive assay allowing
evaluation with high precision of the results of treatment and to detect the
recurrences of GCT at an early, preclinical stage.
PMID- 10690853
TI - Decrease of free thyroxine levels after controlled ovarian hyperstimulation.
AB - Controlled ovarian hyperstimulation could lead to opposing effects on thyroid
function. Therefore, in a prospective study of 65 women undergoing controlled
ovarian hyperstimulation, thyroid hormones, T4-binding globulin, TPO antibodies,
gonadotropins, estradiol, and PRL were measured before and after controlled
ovarian hyperstimulation. After ovarian stimulation (mean +/- SE of mean): free
T4 decreased, 14.4 +/- 0.2 vs. 12.9 +/- 0.2 pmol/L (P < 0.0001); thyroid
stimulating hormone increased, 2.3 +/- 0.3 vs. 3.0 +/- 0.4 mU/L (P < 0.0001); T4
binding globulin increased, 25.2 +/- 0.7 vs. 33.9 +/- 0.9 mg/L (P < 0.0001);
total T4 increased, 98.1 +/- 2.3 vs. 114.6 +/- 2.5 nmol/L (P < 0.0001); total T3
increased, 2.0 +/- 0.04 vs. 2.3 +/- 0.07 nmol/L (P < 0.0001); TPO antibodies
decreased, 370 +/- 233 U/mL vs. 355 +/- 224 U/mL (P < 0.0001); LH decreased, 8.1
+/- 1.1 vs. 0.4 +/-0.1 U/L (P < 0.0001); FSH did not change, 6.5 +/- 0.6 vs. 7.9
+/- 0.9 U/L (P = 0.08); human CG increased, <2 +/- 0.0 vs. 195 +/- 16 U/L (P <
0.0001); estradiol increased, 359.3 +/- 25.9 pmol/L vs. 3491.8 +/-298.3 pmol/L (P
< 0.0001); and PRL increased, 0.23 +/- 0.02 vs. 0.95 +/- 0.06 U/L (P < 0.0001).
Because low maternal free T4 and elevated maternal thyroid-stimulating hormone
levels during early gestation have been reported to be associated with impaired
psychomotor development in the offspring, our findings indicate the need for
additional studies in the children of women who where exposed to high levels of
estrogens around the time of conception.
PMID- 10690854
TI - Use of long-term intravenous phosphate infusion in the palliative treatment of
tumor-induced osteomalacia.
AB - Tumor-induced osteomalacia is characterized by paraneoplastic defects in vitamin
D metabolism, proximal renal tubular functions, and phosphate transport. The
resulting hypophosphatemia can cause generalized pain and muscle weakness, which
significantly affect the quality of life of the patients. Palliative treatment
with calcium, vitamin D, and phosphate replacement is indicated for patients in
whom the causative tumor cannot be completely resected. In this report we
describe a case of tumor-induced osteomalacia in whom adequate oral doses of
phosphate could not be used because of gastrointestinal side-effects. Long term
(3-6 months) iv phosphate infusion delivered by ambulatory infusion pumps in
combination with oral calcium and vitamin D was used successfully to decrease
pain and increase muscle strength. Careful monitoring of serum calcium,
phosphate, and creatinine levels and reliable microinfusion technology have
allowed the long term use of iv phosphate infusion without serious morbidity.
This patient received repeated (three times) phosphate infusions over 8 yr,
resulting in laboratory and symptomatic improvement after each course. However,
this patient did suffer two episodes of central venous catheter-related
infection. Because of potentially serious complications, such as severe
hypocalcemia, calcified right ventricular thrombi, and nephrocalcinosis, long
term iv phosphate infusion should be reserved for patients who cannot tolerate
adequate doses of oral phosphate and for whom the benefits outweigh the risks.
PMID- 10690855
TI - Successful use of pulsatile gonadotropin-releasing hormone (GnRH) for ovulation
induction and pregnancy in a patient with GnRH receptor mutations.
AB - GnRH receptor mutations have recently been identified in a small number of
familial cases of nonanosmic hypogonadotropic hypogonadism. In the present report
we studied a kindred in which two sisters with primary amenorrhea were affected
with GnRH deficiency due to a compound heterozygote mutation (Gln(106)Arg,
Arg(262)Gln) and performed extensive phenotyping studies. Baseline patterns of
gonadotropin secretion and gonadotropin responsiveness to exogenous pulsatile
GnRH were examined in the proband. Low amplitude pulses of both LH and free alpha
subunit (FAS) were detected during 24 h of every 10 min blood sampling. The
proband then received exogenous pulsatile GnRH i.v. for ovulation induction, and
daily blood samples for gonadotropins and sex steroids were monitored. At the
conventional GnRH replacement dose for women with hypogonadotropic hypogonadism
(75 ng/kg), no follicular development occurred. At a GnRH dose of 100 ng/kg, the
level and pattern of gonadotropin secretion more closely mimicked the follicular
phase of normal women; a single dominant follicle was recruited, and an
endogenous LH surge was elicited. However, the luteal phase was inadequate, as
assessed by progesterone levels. At a GnRH dose of 250 ng/kg, the gonadotropin
and sex steroid dynamics reproduced those of normal ovulatory women in both the
follicular and luteal phases, and the proband conceived. The FAS responses to
both conventional and high dose GnRH were within the normal range. The following
conclusions were made: 1) Increased doses of GnRH may be used effectively for
ovulation induction in some patients with GnRH receptor mutations. 2) Higher
doses of GnRH are required for normal luteal phase dynamics than for normal
follicular phase function. 3) Hypersecretion of FAS in response to exogenous
GnRH, which is a feature of congenital hypogonadotropic hypogonadism, was not
seen in this patient with a GnRH receptor mutation.
PMID- 10690856
TI - Anemia in children with cartilage-hair hypoplasia is related to body growth and
to the insulin-like growth factor system.
AB - Cartilage-hair hypoplasia (CHH) is a metaphyseal chondrodysplasia characterized
by severe short-limbed short stature, hypoplastic hair, and defective immunity.
The patients also have anemia. As GH may regulate both body growth and
erythropoiesis, we used CHH as a clinical model to study their
interrelationships. Retrospective analysis of hematological data of 114 patients
showed that the severity of the anemia and macrocytosis in CHH varies with age.
The anemia was most severe in early childhood. A prospective study of 21 patients
with CHH showed that height correlates with hemoglobin (P = 0.006) and mean
corpuscular volume of red blood cells (P < 0.0001). The individual hemoglobin
levels correlated with the GH parameters [P = 0.035 for insulin-like growth
factor I (IGF-I) and P = 0.002 for IGF-binding protein-3], and the mean
corpuscular volume of red blood cell values correlated with fetal hemoglobin.
Bone marrow cultures obtained from six patients with CHH showed reduced or
totally absent erythroid colony formation, which was not influenced by GH or IGF
I in vitro or by GH treatment in vivo. In patients with CHH, we observed an
association between erythropoiesis and growth. We conclude that body growth and
erythropoiesis share common regulators. One of these is the GH-IGF-I axis; other
factors, as not yet identified, may also be important.
PMID- 10690857
TI - Near final height in pubertal growth hormone (GH)-deficient patients treated with
GH alone or in combination with luteinizing hormone-releasing hormone analog:
results of a prospective, randomized trial.
AB - To study the effects of delaying puberty in GH-deficient (GHD) children, we
studied 21 GHD (9 boys, 14 girls), treatment-naive, pubertal patients in a
prospective, randomized trial. Their chronological age was 14.3 +/- 1.6 yr, and
their bone age was 11.3 +/- 1.1 yr (mean +/- SD) at the beginning of the study.
Four patients who developed hypogonadotropic hypogonadism were subsequently
excluded from the study. Patients were randomly assigned to receive GH + LH
releasing hormone analog (LHRH-A) (n = 7), or GH alone (n = 10). GH and LHRH-A
treatment started simultaneously in each patient. GH (Nutropin) was administered
at a dose of 0.1 U/kg x day sc, until patients reached a bone age (BA) of 14 yr
in girls and 16 yr in boys, and LHRH-A (Lupron depot) was administered at a dose
of 300 microg/ kg every 28 days in during 3 yr. We defined GH deficiency as
patients with a growth velocity less than 4 cm/yr, BA delay more than 1 yr in
relationship to chronological age, GH response to two stimulation tests less than
7 microg/L, associated with low serum insulin-like growth factor I and insulin
like growth factor binding protein 3 levels. Statistical analysis was performed
by ANOVA or Kruskall Wallis when variances were not homogeneous. We observed a
significant decrease in the rate of BA maturation in the group treated with
GH+LHRH-A (1.5 +/- 0.2 yr) compared with the group treated with GH alone (4.2 +/
0.5 yr) during the 3 years of LHRH-A therapy (P < 0.05). This delay in BA
maturation produced a significant gain in final height in the group treated with
GH+LHRH-A, which reached - 1.3 +/- 0.5 SD score compared with -2.7 +/- 0.3 SD
score (P < 0.05) in the group treated with GH alone. These results indicate that
delaying puberty with LHRH-A in GHD children during treatment with GH increases
final height.
PMID- 10690858
TI - Hypopituitary females have a high incidence of cardiovascular morbidity and an
increased prevalence of cardiovascular risk factors.
AB - We recently reported that female patients with hypopituitarism receiving
controlled thyroid and steroid hormone substitution, but without GH replacement,
had a more than 2-fold increase in cardiovascular mortality compared to the
general population. In the present study we investigated the incidence of
cardiovascular disease as well as the prevalence of cardiovascular risk factors
in 33 females with hypopituitarism for 6-46 yr (median, 18) compared to those in
33 control subjects recruited from the general population in the same
geographical area and matched for sex, age, smoking habits, educational level,
and residence location. The patients were with a very high probability GH
deficient, as 29 had subnormal serum insulin-like growth factor I levels, and the
other 4 were GH deficient, as assessed by an insulin tolerance test. The
incidence of cardiovascular disease was significantly higher among the
hypopituitary patients (incidence ratio, 3.7; 95% confidence interval, 1.2-11.3),
and the consumption of cardioactive drugs was also significantly higher (P =
0.002). Hypopituitary patients had a lower degree of physical exercise during
their spare time (P = 0.02), a higher waist/hip ratio (P = 0.01), lower high
density lipoprotein cholesterol (P = 0.002), and higher low density/high density
lipoprotein ratio (P = 0.009). Furthermore, the patients had a significantly
increased left atrium size (P = 0.05), but no difference was observed for other
cardiac measures. In the patients, serum insulin-like growth factor I levels
significantly correlated with left ventricular mass index (r = 0.48; P = 0.006),
suggesting that GH has a strong impact on cardiac size. More episodes of
bradycardia (P = 0.05), but no increased occurrence of extrasystolies, were
encountered in the patients during 24-h continuous electrocardiogram monitoring.
Carotid artery intima-media thickness and plaque numbers did not differ between
patients and controls. In conclusion, hypopituitary females exhibit an increased
incidence of cardiovascular disease, higher cardioactive drug consumption, and an
increased prevalence of cardiovascular risk factors. The increased cardiovascular
morbidity could not be ascribed to inadequate estrogen or thyroid hormone
treatment, and unsubstituted GH deficiency is probably an important contributing
factor.
PMID- 10690859
TI - Decreased prorenin processing develops before autonomic dysfunction in type 1
diabetes.
AB - It is well documented that diabetic patients with chronic complications have
decreased renin secretion and elevations in the renin precursor prorenin. It is
uncertain, however, whether the abnormal processing of prorenin is reflective of
microvascular disease, hypertension, or autonomic neuropathy. Dechaux et al.
(Transplant Proc. 18:1598-1599, 1986) observed abnormalities in prorenin
processing in uncomplicated diabetes and suggested that it was the result of
subclinical autonomic neuropathy. To test this hypothesis, we measured renin,
prorenin, and autonomic function in early type 1 diabetes at a time when there is
little or no microvascular disease or hypervolemia. Thirty-seven patients (10
males, 27 females) enrolled 2-22 months after diagnosis in a longitudinal study
in which renin, prorenin, and autonomic function were measured annually for 3
years. Forty-one age-matched control subjects were also studied. PRA in the
diabetic patients at the time of the second and third evaluations was 1.71 +/-
0.24 ng angiotensin I/mL x h and 1.67 +/- 0.24 ng angiotensin I/mL x h,
respectively, significantly lower (P < 0.05) than that of the control subjects in
whom PRA was 2.96 +/- 0.38 ng angiotensin I/mL x h. Prorenin was not different in
the diabetic patients in comparison with controls. The renin to prorenin ratio in
the diabetic patients at the time of the first, second, and third evaluations was
0.260 +/- 0.03, 0.235 +/- 0.05, and 0.227 0.05, respectively, significantly lower
(P < 0.01) than in control subjects in whom the renin to prorenin ratio was 0.475
+/- 0.08. Despite this, at the time of the first and second evaluations, there
was no evidence of autonomic dysfunction and no correlation between any test of
autonomic function and the renin to prorenin ratio. At the time of the third
evaluation, however, the intermediate frequency (0.04-0.15 Hz) power spectra
while patients were supine (an index of sympathetic modulation of heart rate
variability) showed a highly significant (P < .001) correlation with the renin to
prorenin ratio. High frequency (0.15-0.40 Hz) spectra from supine patients at the
third evaluation also correlated with the renin to prorenin ratio (P < 0.01). We
conclude abnormal processing of prorenin develops in diabetic patients prior to
microvascular disease, even before the first evidence of autonomic dysfunction.
Although the latter may play a contributory role, additional as yet unidentified
mechanisms seem to interrupt the processing of prorenin in early diabetes.
PMID- 10690860
TI - The influence of thinness and smoking on bone loss and response to hormone
replacement therapy in early postmenopausal women.
AB - We studied the influence of thinness and smoking in 153 early postmenopausal
women from a 3-yr period, comparing treatments of 1 or 2 mg estradiol with
placebo. The baseline body mass index (BMI) was significantly associated with
bone resorption (r = -0.26, P < 0.01 for urinary CrossLaps with 21% difference
between extreme tertiles) with a consequent association between BMI and bone
mineral density (BMD; r = 0.38, P < 0.001 for BMD of hip with 10% difference
between extreme tertiles). A low BMI led to an increased rate of loss (r = 0.45,
P < 0.01 for BMD of spine), whereas response to treatment with either 1 or 2 mg
estradiol was independent of BMI. Smoking was associated with a 4% lower BMD at
baseline compared with that in nonsmokers. This effect was additive with that of
BMI. For smokers the increase in serum estradiol during hormone replacement
therapy was only half of that in nonsmokers. For women treated with placebo or 2
mg estradiol, serum FSH levels were similar in smokers and nonsmokers, but during
treatment with 1 mg estradiol, serum FSH was significantly less suppressed in
smokers. This was mirrored in the BMD response, where smokers responded similarly
to 2 mg estradiol and placebo as did nonsmokers, whereas smokers receiving 1 mg
estradiol experienced only half the increase compared to nonsmokers. In
conclusion, thinness and smoking are important risk factors for osteoporosis
development, but are counteracted by hormone replacement therapy.
PMID- 10690861
TI - Carrier analysis and prenatal diagnosis of congenital adrenal hyperplasia caused
by 21-hydroxylase deficiency in Chinese.
AB - Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder
mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. We screened
1,000 healthy people, using a previously developed differential PCR method
combined with single-strand conformation polymorphism and amplification-created
restriction site methods for the carrier detection of the CYP21 gene deficiency.
Our results indicated that the rate of occurrence of the heterozygous CAH carrier
was about 12 in 1,000, with a gene frequency of 0.0060 and an incidence frequency
of 1 in 28,000 in the Chinese population. In addition, 9 cases of CAH families
were performed with prenatal diagnosis. Among them, 3 cases were diagnosed as the
severe form, 4 cases carried the heterozygous mutation, and 2 were normal. This
is the first report of carrier frequency analysis and prenatal diagnosis of 21
hydroxylase deficiency in Chinese.
PMID- 10690862
TI - Exogenous 20K growth hormone (GH) suppresses endogenous 22K GH secretion in
normal men.
AB - The physiological and pharmacological functions of the 20-kDa human GH (20K-hGH)
isoform are unknown. We conducted a pharmacokinetic study of recombinant 20K-hGH
in human subjects (Phase I clinical trial). Placebo or 20K-hGH was administered
sc to normal men (20-31 yr of age, n = 6-8 per group) at 2100 h. Serum 20K- and
22K-hGH levels were monitored every 30 min for 24 h by specific enzyme-linked
immunosorbent assays. Serum free fatty acid, insulin-like growth factor I,
insulin, and glucose levels were measured for 24 h. In the placebo group, the
secretion profiles of endogenous 20K- and 22K-hGH were pulsatile and similar to
each other. The proportion of 20K- to 22K-hGH was fairly constant. In the 20K-hGH
treated groups, serum 20K-hGH levels increased in a dose-dependent manner over
the dose range of 0.01-0.1 mg/kg. Maximum serum 20K-hGH levels were reached at 3
4 h and decreased with half-lives of 2-3 h. Marked suppression of endogenous 22K
hGH secretion was observed in a time-dependent manner. Serum free fatty acid and
insulin-like growth factor I levels were significantly elevated (P < 0.01) at 4,
8, and 12 h and at 8, 12, and 24 h after 20K-hGH administration, respectively.
Serum insulin and glucose levels did not change significantly within 24 h. These
results suggested that: 1) regulation of 20K-hGH secretion is physiologically the
same as that of 22K-hGH; 2) the pharmacokinetics after sc injection of 20K-hGH
are comparable with those of 22K-hGH; 3) 20K-hGH regulates hGH secretion through
"GH-induced negative feedback mechanisms"; and 4) administration of 20K-hGH is
expected to exert GH actions (growth-promoting activity and lipolytic activity).
Monitoring of serum 20K- and 22K-hGH levels may be useful in evaluating the
effects of administered GH isoforms on their own release from the pituitary.
PMID- 10690863
TI - Relationship between serum inhibin A and B and ovarian follicle development after
a daily fixed dose administration of recombinant follicle-stimulating hormone.
AB - The aim of this study was to investigate the relationship of serum inhibin A and
inhibin B to ovarian follicular development in women undergoing pituitary down
regulation and ovarian stimulation with a fixed daily dose of recombinant human
FSH in an in vitro fertilization program. Thirty-eight patients were treated
randomly with either 100 or 200 IU/day recombinant human FSH (Puregon) for a
period of 9-14 days. Serum FSH, inhibin A, inhibin B, 17beta-estradiol, and
follicular size and number were determined before FSH treatment and every second
day from days 4-6 throughout FSH treatment. Serum FSH increased in a dose-related
manner to reach a maximum by days 4-6 and remained unchanged over the duration of
treatment. Serum inhibin A and 17beta-estradiol also increased with increasing
FSH dose and continued to rise throughout the FSH treatment period. By contrast,
serum inhibin B was increased by days 4-6 at both doses of FSH to reach a maximum
by days 7-8, remaining unchanged thereafter. Serum inhibin B and, to a lesser
extent, inhibin A correlated significantly with the number of oocytes retrieved
even when assessed early (days 4-6) in the treatment period (inhibin B vs. number
of oocytes: r = 0.89; P < 0.001; inhibin A vs. number of oocytes: r = 0.61; P <
0.05). Serum inhibin A, inhibin B, and 17beta-estradiol were weakly correlated
with the number of follicles less than 11 mm when assessed on a daily basis;
stronger correlations were observed with the greater than 11-mm follicles during
the late stages of treatment. It is concluded that serum inhibin B levels
determined during the early stages (e.g. days 4-6) of fixed dose FSH treatment
provide an early indicator of the number of recruited follicles that are destined
to form mature oocytes. In this context, serum inhibin B may be of predictive
value in monitoring ovarian hyperstimulation treatment for in vitro
fertilization.
PMID- 10690864
TI - The effect of hormone replacement therapy on cardiovascular hemodynamics in women
with Turner's syndrome.
AB - Women with Turner's syndrome, the majority of whom are estrogen deficient, have
an increased incidence of coronary artery disease. The aim of this study was to
assess the effects of hormone replacement therapy (HRT) on central arterial
hemodynamics, insulin sensitivity, and lipids in adults with Turner's syndrome.
Twenty-one women with Turner's syndrome were studied prospectively, on and off 3
months of estradiol valerate in combination with levonorgestrel. The following
measurements were made: body mass index, waist/hip ratio, serum lipids, fasting
insulin and glucose, and mean arterial blood pressure. Aortic root pressure and
waveforms were estimated noninvasively and the augmentation index (AI), a measure
of aortic stiffness, was calculated. The AI was significantly lower during
estrogen therapy (22% vs. 15%; P = 0.008), suggesting a reduction in central
arterial stiffness. Fasting insulin and glucose concentrations were also
significantly lower during HRT (P = 0.01 and P = 0.0004, respectively). There was
no difference in body mass index, serum lipids, or brachial and aortic blood
pressures on and off treatment. Total cholesterol was correlated with the AI (r =
0.4; P = 0.03). These results suggest that HRT in women with Turner's syndrome
has a favorable effect on central arterial hemodynamics and insulin sensitivity.
The lack of effect on serum lipids suggests that the effects of HRT on aortic
compliance may be mediated by an improvement in endothelial function.
PMID- 10690865
TI - Adult height in short normal girls treated with gonadotropin-releasing hormone
analogs and growth hormone.
AB - Combined treatment with GH and GnRH analogs (GnRHa) has been proposed to improve
final adult height in true precocious puberty, GH deficiency, and short normal
subjects with early or normal timing of puberty with still controversial results.
We treated 12 girls with idiopathic short stature and normal or early puberty
with GH and GnRHa and followed them to adult height; 12 girls comparable for
auxological and laboratory characteristics treated with GH alone served to better
evaluate the efficacy of addition of GnRHa. At the start of combined treatment,
the chronological age of the girls (CA; mean +/- SD) was 10.2 +/- 0.9 yr, bone
age (BA) was 10.6 +/- 1.9 yr, height SD score for BA was - 1.81 +/- 0.8, PAH was
146.3 +/- 5.0 cm. PAH was significantly lower than target height (TH 152.7 +/-
3.6 cm; P < 0.005). GH was given at a dose of 0.3 mg/kg x week, sc, 6 days
weekly, and GnRHa (depot-triptorelin) was given at a dose of 100 microg/kg every
21 days, im. The 12 girls were treated with GH alone at the same dose; at the
start of therapy their CA was 10.7 +/- 1.0, BA was 10.1 +/- 1.4 yr, height SD
score for BA was - 1.65 +/- 0.8, PAH was 145.6 +/- 4.4 cm, and TH was 155.8 +/-
4.6 cm. Pubertal Tanner stage in both groups was B2P2 or B3P3. LHRH test and
pelvic ultrasound showed the beginning of puberty. The GH response to standard
provocative tests was 10 g/L or more. The mean period of treatment was 4.6 +/-
1.7 yr in the group treated with GH plus GnRHa and 4.9 +/- 1.4 yr in the group
treated with GH alone; both groups discontinued treatment at comparable CA and
BA. Adult height was considered to be attained when growth during the preceding
year was less than 1 cm, with a BA of over 15 yr. Patients in the group treated
with GH plus GnRHa showed an adult height significantly higher (P < 0.001) than
the pretreatment PAH (156.3 +/- 5.9 vs. 146.3 +/- 5 cm); the gain in centimeters
calculated between pretreatment PAH and adult height was 10 +/- 2.9 cm, and 7 of
12 girls had a gain over 10 cm. Target height was significantly exceeded. Height
SD score for BA increased from - 1.81 +/-0.8 to -0.85 +/- 1.0. The GH alone group
reached an adult height higher than the pretreatment PAH (151.7 +/- 2.7 vs. 145.6
+/- 4.4 cm); the gain in final height vs. pretreatment PAH was 6.1 +/- 4.4 cm,
and 5 of 12 girls did not gain more than 4 cm. TH was even not reached. The
height SD score did not significantly change. No adverse effects were observed in
either group. All of the girls showed good compliance and were satisfied with the
results. Our experience suggests that the combination of GH and GnRHa is
significantly more effective in improving adult height than GH alone in girls
with idiopathic short stature, early or normal onset of puberty, and low PAH well
below the third percentile and TH. As the cost-benefit of such invasive treatment
must be seriously considered, further studies are needed due to the small sample
of our patients as well as in other studies reported to date.
PMID- 10690866
TI - Opposite variations in maternal and neonatal thyroid function induced by iodine
supplementation during pregnancy.
AB - Whereas the consequences of extremes in iodine intake are well described, much
less is known about the effect of more moderate variations in maternal iodine
intake on fetal thyroid function. The present study performed in Denmark with
mild to moderate iodine deficiency dealt with the effect of maternal iodine
supplementation on thyroid function in the mother at term and in the
fetus/neonate. Serum was collected consecutively from pregnant women at term (n =
144) and from cord blood (n = 139). Forty-nine women had a regular intake of
vitamin and mineral tablets with iodine (150 microg/day) during pregnancy, and 95
took no artificial iodine supplementation. Iodine supplementation (+I) induced
opposite variations in thyroid function in the mother and the fetus. In +I
mothers, TSH was 7.6% lower than in mothers with no supplementation (P < 0.05).
In cord blood, on the contrary, TSH was 27.3% higher in the +I group (P < 0.05).
The variations were caused by opposite shifts in TSH frequency distribution in
mothers and neonates. The association between iodine supplementation and high
serum TSH in the neonates was further substantiated by an inverse correlation
between thyroglobulin and TSH in cord blood (P < 0.001), whereas no specific
pattern was observed in the mothers. High serum thyroglobulin was a marker of low
iodine intake in both mothers and neonates. The results suggest that the fetal
thyroid, at least in areas of mild iodine deficiency, is more sensitive to the
inhibitory effect of iodine than hitherto anticipated.
PMID- 10690867
TI - Abnormal heart rate variability in adults with growth hormone deficiency.
AB - GH-deficient (GHD) patients have increased risk of cardiovascular death and may
have cardiac structural abnormalities. In non-GHD patients these are associated
with cardiac autonomic dysfunction, and it is possible that autonomic dysfunction
is also present in GHD patients. Power spectral analysis (PSA) of heart rate
variability (HRV) indirectly measures cardiac autonomic tone and generates peaks
at 3 frequency bands, very low frequency (VLF), low frequency (LF) and high
frequency (HF). The area under the LF curve is considered to reflect
predominantly cardiac sympathetic activity, whereas HF indicates parasympathetic
activity. PSA of HRV was performed in 14 normotensive GHD patients (5 men and 9
women; mean age, 35.2 yr) and 19 healthy controls (9 men and 10 women; mean age,
38.3 yr). GHD patients had 26% lower normalized LF power (P < 0.004), 39% higher
normalized HF power (P < 0.001), 28% lower normalized VLF power (P < 0.046), and
51% lower LF/HF ratio (an index of sympathovagal balance; P < 0.001) compared to
controls. These data indicate that heart rate variability is abnormal in patients
with GHD. The decreased sympathetic tone could be a consequence of reduced
central sympathetic tone or altered cardiac responsiveness to autonomic control
and may contribute to the increased cardiovascular risk in GHD patients.
PMID- 10690868
TI - Growth hormone replacement therapy is not associated with retinal changes.
AB - GH and/or growth factors are thought to play a role in the pathogenesis of
diabetic retinopathy. In addition, the occurence of retinal changes mimicking
diabetic retinopathy in two GH-deficient (GHD) patients receiving GH replacement
therapy (GHRT) has recently been reported. The present study was performed to
evaluate whether this was a coincidence or whether GHRT might regularly induce
retinal changes. Sixty-one GHD patients on GHRT with a mean age of 42.5 +/-17.3
yr were examined by one ophthalmologist (AR). The mean duration of GHRT was 8.4
+/- 3.7 yr in childhood onset and 3.5 +/- 2.1yr in adult onset patients. Plasma
insulin-like growth factor I concentrations were 76.4 +/- 49.6 ng/mL before GHRT
and 244.3 +/- 119.2 ng/mL while receiving GHRT with a dose of 1.7 +/- 0.7 IU/day.
After pupil dilatation with tropicamide, fundus examinations of both eyes were
performed using a Volk 90 diopter fundus lens with a slit lamp (Haag Streit,
Bern, Switzerland). In none of the patients were vascular or retinal changes like
macular edema, microaneurysms, hemorrhages, hard exsudates, cotton wool spots,
preproliferative signs, or proliferations found. The optic discs were also normal
in all patients. We conclude, therefore, that long-term GHRT can be administered
safely in GHD patients without an increased risk of retinal changes.
PMID- 10690869
TI - A survey on adrenal incidentaloma in Italy. Study Group on Adrenal Tumors of the
Italian Society of Endocrinology.
AB - The aim of this study was to perform a national survey on occasionally discovered
adrenal masses [adrenal incidentalomas (AI)] under the auspices of the Italian
Society of Endocrinology. This multicentric and retrospective evaluation of
patients with AI includes 1096 cases collected in 26 centers between 1980 and
1995. Relevant information was obtained by means of a specifically tailored
questionnaire. Of the 1096 forms received, 1004 were retained for final analysis.
Patients were 420 males and 584 females, aged between 15-86 yr (median, 58 yr).
Mass size (computed tomography measurement) ranged from 0.5-25 cm (median, 3.0
cm). Hormonal work-up demonstrated that 85% of the masses were nonhypersecretory,
9.2% were defined as subclinical Cushing's syndrome, 4.2% were pheochromocytomas,
and 1.6% were aldosteronomas. Adrenalectomy was performed in 380 patients with
removal of 198 cortical adenomas (52%), 47 cortical carcinomas (12%), 42
pheochromocytomas (11%), and other less frequent tumor types. Patients with
carcinoma were significantly younger than patients with adenoma (median, 46;
range, 17-84; vs. 57, 16-83 yr; P = 0.05). Adenomas were significantly smaller
than carcinomas (3.5, 1-15 vs. 7.5, 2.6-25 cm; P < 0.001), and a cut-off at 4.0
cm had the highest sensitivity (93%) in differentiating between benign and
malignant tumors. Hormonal work-up of patients with subclinical Cushing's
syndrome showed low baseline ACTH in 79%, cortisol unsuppressibility after 1 mg
dexamethasone in 73%, above normal urinary free cortisol in 75%, disturbed
cortisol rhythm in 43%, and blunted ACTH response to CRH in 55%. Only 43% of
patients with pheochromocytoma were hypertensive, and 86% showed elevated urinary
catecholamines. All patients with aldosteronoma were hypertensive and had
suppressed upright PRA. These results indicate that mass size is the most
reliable variable in separating benign from malignant AI. Adrenalectomy should be
recommended for AI greater than 4.0 cm because of the increased risk of
malignancy, especially in young patients. Endocrine evaluation should be
performed in all patients to identify silent states of hormone excess.
PMID- 10690870
TI - Hysterectomy, oophorectomy, and endogenous sex hormone levels in older women: the
Rancho Bernardo Study.
AB - This study examines the cross-sectional association of hysterectomy and
oophorectomy status, chronological age, and years since menopause with plasma
levels of total and bioavailable testosterone and estradiol, androstenedione,
estrone, and sex hormone-binding globulin (SHBG) in community-dwelling
postmenopausal women who were not using estrogen replacement therapy. Six hundred
and eighty-four women, aged 50-89 yr, were surveyed for hysterectomy and
oophorectomy status and had plasma obtained between 1984-1987. Of these, 438
(67%) had not undergone hysterectomy or oophorectomy (intact), 123 (18%) reported
hysterectomy with bilateral oophorectomy, and 123 (18%) reported hysterectomy
with conservation of 1 or both ovaries. After adjustment for age and body mass
index, both total and bioavailable testosterone levels were reduced by more than
40% (P < 0.001) in hysterectomized women with bilateral oophorectomy compared to
those in intact women, with intermediate levels observed in hysterectomized women
with ovarian conservation. Androstenedione levels were about 10% lower in
hysterectomized women with or without ovarian conservation compared to those in
intact women (P = 0.039). Total estradiol levels tended to be lower (P = 0.095)
in bilaterally oophorectomized women. Levels of bioavailable estradiol, estrone,
and SHBG did not differ by hysterectomy and oophorectomy status. Among intact
women, total, but not bioavailable, testosterone levels increased with age (P =
0.015), reaching premenopausal levels for the 70-79 decade with relatively stable
levels thereafter. Among oophorectomized women, total and bioavailable
testosterone levels did not vary with age and were 40-50% lower than those in
intact women throughout the 50-89 yr age range. Androstenedione levels decreased
27% and SHBG levels increased 30% (P < 0.001) with age in intact, but not
oophorectomized, women. Levels of other hormones did not vary with age.
Stratification by years since menopause or surgery yielded similar results. These
results demonstrate that the postmenopausal ovary remains a critical source of
androgen throughout the lifespan of older women. The clinical consequences of
lower testosterone levels years after oophorectomy are unknown. Reconsideration
of prophylactic oophorectomy and clinical trials to evaluate the effects of
androgen replacement after oophorectomy are needed.
PMID- 10690871
TI - Adrenal suppression, evaluated by a low dose adrenocorticotropin test, and growth
in asthmatic children treated with inhaled steroids.
AB - The aim of the present study was to evaluate the prevalence of adrenal
suppression and growth retardation in children using moderate doses of budesonide
or fluticasone propionate. Seventy-five asthmatic children were randomly divided
into three treatment groups: 30 to the fluticasone propionate (FP), 30 to the
budesonide (BUD), and 15 to the cromone (CROM) group. FP doses were 500
microg/day during the first 2 months and 200 microg/day thereafter. The
respective BUD doses were 800 and 400 microg/day. A low dose ACTH (0.5
microg/1.73 m2) test was performed before treatment and 2, 4, and 6 months later.
The test was considered abnormal if the stimulated serum cortisol concentration
was more than 2 SD lower than the pretreatment mean (<330 nmol/L). The low dose
ACTH test was abnormal after both the high and low steroid doses in 23% of the
children. At the 4 month measurement there were more abnormal tests in the BUD (n
= 9) than in the FP (n = 5) group (P < 0.05). At that time also the stimulated
concentration of serum cortisol was lower in the BUD than in the CROM group (P <
0.01), whereas the difference between the FP and CROM groups was not significant.
During the study year the mean decrease in height SD score was 0.23 in the
children treated with BUD, 0.03 in the children treated with FP, and 0.09 in the
children treated with CROM; the difference between the BUD and FP groups was
significant (P < 0.05). In conclusion, the low dose ACTH test revealed mild
adrenal suppression in a quarter of the children using moderate doses of inhaled
steroids. A FP dose of 200 microg/day caused less adrenal and growth suppression
than did a BUD dose of 400 microg/day.
PMID- 10690872
TI - Phenotypic features, androgen receptor binding, and mutational analysis in 278
clinical cases reported as androgen insensitivity syndrome.
AB - Androgen insensitivity syndrome (AIS) is the most common single entity that
results in male under-masculinization, but large cohort studies of AIS have
rarely been performed. Over the last decade, nationwide cooperation between
pediatric endocrinologists in the United Kingdom has allowed the creation of a
database of cases of intersex and ambiguous genitalia where detailed clinical
information on every notified case has been collected via a questionnaire. Among
the 816 entries recorded by January 1999, there were 105 clinically diagnosed
cases of complete AIS (CAIS) and 173 cases of partial AIS (PAIS). A
masculinization score was devised by scoring the external phenotype, and a score
of 12 represented normal masculinization. Androgen receptor (AR) binding was
determined by studying binding capacity (Bmax) and receptor affinity (K(d)), and
cases were classified as either zero, abnormal, or normal binding. Mutation
screening of all eight exons of the AR gene was performed by single-strand
conformational polymorphism analysis, followed by direct DNA sequencing. All
cases of PAIS presented within the first month of birth. The median age at
presentation of children with CAIS was 1 yr (P10,P90: 0.1,10.4). The testes were
palpable in the labioscrotal folds or the inguinal region in 77% and 41% of cases
of CAIS and PAIS, respectively. There was marked overlap between the
masculinization score of those children with PAIS reared as girls [2.5(P10,P90:1,
6)] and those reared as boys [3(P10,P90:2, 7.5)]. Gonadectomy was performed
prepubertally in 66% and postpubertally in 29% of the cases of CAIS. The median
age of the latter group was older at 14 yr (P10,P90:0.1,18). No cases of
malignancy or carcinoma in situ were reported in the 121 cases of AIS where
histology results were available. Biochemical endocrine investigations were
reported to have been performed in a greater number of cases of PAIS than CAIS
(98% vs. 48%). AR binding was abnormal in 44 of 51 (86%) and 40 of 113 (35%)
cases of CAIS and PAIS, respectively. Zero binding was encountered in 29 of 43
(67%) and 1 of 55 (2%) cases of CAIS and PAIS, respectively. Mutational analysis
of the AR gene, performed in 102 index cases was positive in 57 of 69 (83%) cases
of CAIS and 12 of 43 (28%) cases of PAIS. In 24 of these cases, the mutation
identified was novel. The mutations in PAIS cases were all missense, whereas in
CAIS the mutations were more diverse. AR binding was only normal in 3 of 69
mutation-positive cases. In the PAIS group, mutation-positive cases had a
significantly higher Kd and Bmax compared to the mutation negative cases. The
clinical diagnosis of AIS can be confirmed in a significant number of cases by a
combination of androgen-binding studies and mutational analysis. There is some
correlation between the phenotypic features and the abnormalities discovered on
mutational analysis of the AR gene, but there is a need to improve this further
by developing optimal bioassays of AR function. The phenotypic heterogeneity
among clinically diagnosed cases of AIS emphasizes the need for appropriate
comprehensive evaluation of male under-masculinization.
PMID- 10690873
TI - Measurement of urinary melatonin: a useful tool for monitoring serum melatonin
after its oral administration.
AB - The relevance of measuring urinary melatonin (MLT) for human pineal research is
sometimes questioned, and the relationship among serum levels of MLT, urinary
excretion of the unmetabolized hormone, and excretion of MLTs main metabolite, 6
hydroxymelatonin sulfate (aMT6s), is still uncertain. We applied a well
established RIA for measuring MLT in serum to urine samples, characterized its
criteria of performance in this body fluid, and used it for human studies. In 16
adolescents, the endogenous overnight MLT secretion, expressed as the area under
the concentration time curve, correlated significantly with the amounts of
urinary aMT6s (r = 0.86; P < 0.0001) and urinary MLT (r = 0.70; P = 0.0027)
excreted during a 16-h observation period. Oral administration of 3 mg exogenous
MLT in 17 healthy volunteers resulted in peak MLT serum levels differing 28-fold
among subjects (940-27,240 pg/ mL; range). In this study urinary MLT, but not
aMT6s, excretion was associated with blood MLT concentrations (r = 0.76; P =
0.0004 vs. r = 0.02; P = 0.93, respectively). Thus, endogenous MLT production can
be assessed accurately by measuring either aMT6s or MLT excretion. After oral
application of MLT, however, only measurement of MLT excretion is a reliable
marker of serum concentrations. Determination of MLT in urine may prove to be a
useful tool for drug monitoring after oral administration of the pineal hormone.
PMID- 10690874
TI - Diagnosis of thyroid malignant lymphoma by reverse transcription-polymerase chain
reaction detecting the monoclonality of immunoglobulin heavy chain messenger
ribonucleic acid.
AB - Distinguishing between thyroid malignant lymphoma and lymphocytic thyroiditis
(Hashimoto's thyroiditis) is quite difficult and problematic. Molecular
techniques to detect clonal lymphoid proliferation based on Ig heavy chain (IgH)
gene rearrangement may be used to facilitate more accurate diagnosis of malignant
lymphoma. We recently established a method for diagnosing thyroid tumors by
analyzing ribonucleic acids (RNAs) extracted from the needles used for fine
needle aspiration biopsy (aspiration biopsy-RT-PCR). By applying the aspiration
biopsy-RT-PCR method to detection of the monoclonality of IgH messenger RNA
(mRNA), an accurate molecular-based diagnosis of malignant lymphoma can be
established as an adjunct to cytological diagnosis. We first studied RNAs from
fresh tissues samples of 8 cases of Hashimoto's thyroiditis and 18 malignant
lymphomas to detect the monoclonality of IgH mRNA by seminested RT-PCR.
Monoclonality was detected in 8 of 18 (44.4%) malignant lymphomas, but in none of
the 8 cases of Hashimoto's thyroiditis. We then studied aspirates from 10 cases
of thyroid malignant lymphoma, 4 cases of Hashimoto's thyroiditis, and 1 case
each of adenomatous goiter and papillary carcinoma. Monoclonality was detected in
the aspirates from 4 of 10 malignant lymphomas (40%), but not from other tissues.
Thus, RT-PCR detection of monoclonality of IgH mRNA in addition to cytological
examination may be useful in diagnosing thyroid malignant lymphoma.
PMID- 10690875
TI - Free androgen index and leptin are the most prominent endocrine predictors of
ovarian response during clomiphene citrate induction of ovulation in
normogonadotropic oligoamenorrheic infertility.
AB - We have previously demonstrated that obese hyperandrogenic amenorrheic women are
less likely to ovulate after clomiphene citrate (CC) medication. The present
study was designed to identify whether additional endocrine screening
characteristics, all potentially involved in ovarian dysfunction in 182
normogonadotropic oligoamenorrheic infertile women, are associated with ovarian
response, which may improve overall prediction of CC-resistant anovulation.
Standardized endocrine screening took place before initiation of CC medication
(50 mg/day; increasing doses up to 150 mg/day if required) from cycle days 3-7.
Screening included serum assays for fasting insulin and glucose, insulin-like
growth factor I (IGF-I), IGF-binding protein-1 (IGFBP-1), IGFBP-3, free IGF-I,
inhibin B, leptin, and vascular endothelial growth factor. Forty-two women (22%
of the total group) did not ovulate at the end of follow-up (a total number of
325 cycles were analyzed). Fasting serum insulin, insulin/glucose ratio, IGFBP-1,
and leptin were all significantly different in univariate analyses (P < or =
0.02), comparing CC responders vs. nonresponders. Forward stepwise multivariate
analyses in combination with factors reported earlier for prediction of patients
remaining anovulatory after CC revealed a prediction model including 1) free
androgen index (FAI = testosterone/sex hormone-binding globulin ratio), 2) cycle
history (oligomenorrhea or amenorrhea), 3) leptin level, and 4) mean ovarian
volume. These data suggest that decreased insulin sensitivity, hyperandrogenemia,
and obesity, all associated with polycystic ovary syndrome, are prominent factors
involved in ovarian dysfunction, preventing these ovaries from responding to
stimulation by raised endogenous FSH levels due to CC medication. By using leptin
instead of body mass index or waist to hip ratio, the previous model for
prediction of patients remaining anovulatory after CC medication could be
slightly improved (area under the curve from 0.82-0.85). This may indicate that
leptin is more directly involved in ovarian dysfunction in these patients. The
capability of insulin and IGFBP-1 to predict patients who remain anovulatory
after CC disappears when FAI enters into the model due to a significant
correlation between FAI and these endocrine parameters. This suggests that
markers for insulin sensitivity (e.g. IGFBP-1 and insulin) are associated with
abnormal ovarian function through its correlation with androgens, whereas leptin
is directly involved in ovarian dysfunction.
PMID- 10690876
TI - Is leptin associated with hypertensive retinopathy?
AB - Previous studies have demonstrated that elevated plasma leptin concentrations are
associated with essential hypertension. It has also recently been shown that
leptin plays a promoting role in angiogenesis, and the vascular endothelium
expresses the long form of leptin receptor. Those data led us to hypothesize that
leptin might contribute to end-organ damage in hypertension. Thus, in the present
study we evaluated the relationship between plasma leptin concentrations and
hypertensive retinopathy (HR). One hundred and eleven patients newly diagnosed
with essential hypertension [EHT; mean age, 43.5 +/-10.7 yr; body mass index
(BMI), 28.1 +/- 4.4 kg/m2; male/female ratio, 71/40] and 79 healthy normotensive
control subjects (NT; mean age, 43.6 +/- 9.2 yr; BMI, 28.2 +/- 3.3 kg/m2;
male/female ratio, 50/29) were enrolled in the study. For the assessment of
retinopathy according to the Keith-Wagener classification, direct and indirect
ophthalmoscopy were performed in all subjects after dilatation of the pupils.
Plasma leptin levels were significantly higher in EHT (11.8 +/- 11.1 ng/mL) than
in NT (7.2 +/- 5.1 ng/mL) (P = 0.003). Plasma leptin concentrations were strongly
correlated with BMI in both EHT (r = 0.45; P = 0.001) and NT (r = 0.38; P =
0.001) groups. Plasma leptin in patients with grade 2 HR (24.8 +/- 15.8 ng/mL; n
= 22) was significantly higher than that in patients with grade 1 HR (16.1 +/-
4.9 ng/mL; n = 29; P = 0.001), grade 0 HR (5.1 +/- 3.1 ng/mL; n = 60; P = 0.001),
and NT (P = 0.001). Plasma leptin in patients with grade 1 HR was also
significantly higher than that in patients without retinopathy (P = 0.001) or in
NT (P = 0.001). The estimated threshold of plasma leptin concentration for HR was
10.2 ng/mL. This critical leptin level served largely to separate patients with
retinopathy from those without retinopathy. In summary, our results show that
plasma leptin concentrations increase progressively with higher grades of
hypertensive retinopathy even after correction for BMI, suggesting that a
critical leptin level is needed for the development of retinopathy. Elevated
concentrations of plasma leptin might be secondary to release of leptin by the
vascular endothelium damaged by high blood pressure, as an epiphenomenon.
However, a pathogenic role for leptin in hypertensive retinopathy cannot be
excluded.
PMID- 10690877
TI - Association analysis of the cytotoxic T lymphocyte antigen-4 (CTLA-4) and
autoimmune regulator-1 (AIRE-1) genes in sporadic autoimmune Addison's disease.
AB - Although autoimmune Addison's disease (AAD) may occur as a component of the
monogenic autoimmune polyendocrinopathy type 1 syndrome (APS1), it is most
commonly found as an isolated disorder or associated with the autoimmune
polyendocrinopathy type 2 syndrome (APS2). It is likely that sporadic (non-APS1)
AAD is inherited as a complex trait; however, apart from the major
histocompatibility complex, the susceptibility genes remain unknown. We have
examined polymorphisms at two non-major histocompatibility complex candidate
susceptibility loci in sporadic (non-APS1) AAD: the cytotoxic T lymphocyte
antigen-4 (CTLA-4) gene and the autoimmune regulator (AIRE-1) gene. DNA samples
from AAD subjects (n = 90) and local controls (n = 144 for CTLA-4; n = 576 for
AIRE-1) were analyzed for the CTLA-4A/G polymorphism in exon 1 of the CTLA-4 gene
and for the common mutant AIRE-1 allele (964de113) in United Kingdom subjects
with APS1, by using the restriction enzymes Bst7II and BsrBI, respectively. There
was an association of the G allele at CTLA-4A/G in AAD subjects (P = 0.008 vs.
controls), which was stronger in subjects with AAD as a component of APS2 than in
subjects with isolated AAD. In contrast, the mutant AIRE-1 964del13 allele was
carried in one each of the 576 (0.2%) control subjects and the 90 (1.1%) AAD
subjects as a heterozygote (P = 0.254, not significant), suggesting that this
common AIRE-1 gene abnormality does not have a major role in sporadic (non-APS1)
AAD.
PMID- 10690878
TI - Disturbed neuroendocrine-immune interactions in chronic fatigue syndrome.
AB - The present study was designed to investigate the interaction between
neuroendocrine mediators and the immune system in chronic fatigue syndrome (CFS).
We examined the sensitivity of the immune system to the glucocorticoid agonist
dexamethasone and the beta2-adrenergic agonist terbutaline in 15 adolescent girls
with CFS and 14 age- and sex-matched controls. Dexamethasone inhibits T-cell
proliferation in healthy controls and in CFS patients. However, the maximal
effect of dexamethasone on T-cell proliferation is significantly reduced in CFS
patients as compared with controls. The beta2-adrenergic receptor agonist
terbutaline inhibits tumor necrosis factor-alpha production and enhances
interleukin-10 production by monocytes. Our data demonstrate that the capacity of
a beta2-adrenergic agonist to regulate the production of these two cytokines is
also reduced in CFS patients. We did not observe differences in baseline or CRH
induced cortisol and ACTH between CFS patients and controls. Baseline
noradrenaline was similar in CFS and controls, whereas baseline adrenaline levels
were significantly higher in CFS patients. We conclude that CFS is accompanied by
a relative resistance of the immune system to regulation by the neuroendocrine
system. Based on these data, we suggest CFS should be viewed as a disease of
deficient neuroendocrine-immune communication.
PMID- 10690879
TI - Response of leucine metabolism to hyperinsulinemia in hypothyroid patients before
and after thyroxine replacement.
AB - We have investigated the effect of hypothyroidism and insulin on protein
metabolism in humans. Six hypothyroid patients were studied in a postabsorptive
state before and after 5 months of regular treatment for hypothyroidism (153 +/-
17 microg/day of L-T4). The effect of insulin was assessed under hyperinsulinemic
euglycemic and eukalemic conditions. Insulin was infused for 140 min at 0.0063 +/
0.0002 nmol/kg x min. An amino acid infusion was used to blunt insulin-induced
hypoaminoacidemia. Whole body protein turnover was measured using L-[1-13C]
leucine. When compared to L-T4-induced subclinical thyrotoxic state,
hypothyroidism induced a significant decrease (P < 0.05) in leucine endogenous
appearance rate (a reflection of proteolysis; 0.89 +/- 0.09 vs. 1.33 +/- 0.05
micromol/kg x min), oxidation (0.19 +/- 0.02 vs. 0.25 +/- 0.03 micromol/kg x
min), and nonoxidative disposal (a reflection of protein synthesis; 0.87 +/- 0.11
vs. 1.30 +/- 0.05 micromol/ kg x min). Insulin lowered proteolysis during both
the subclinical thyrotoxic and hypothyroid states. Hypothyroidism impaired the
antiproteolytic effects of insulin. Thyroid hormones are, therefore, essential
for the normal antiproteolytic action of insulin.
PMID- 10690880
TI - Isolated familial somatotropinomas: establishment of linkage to chromosome
11q13.1-11q13.3 and evidence for a potential second locus at chromosome 2p16-12.
AB - The majority of somatotropinomas are sporadic, although a small number occur with
a familial aggregation, either as a component of an endocrine neoplasia complex
that includes multiple endocrine neoplasia type 1 (MEN-1) and Carney complex
(CNC) or as isolated familial somatotropinomas (IFS). IFS is defined as the
occurrence of at least two cases of acromegaly or gigantism in a family that does
not exhibit MEN-1 or CNC. This rare disease is associated with loss of
heterozygosity (LOH) on chromosome 11q13, the locus of the MEN-1 gene, although
the MEN-1 sequence and expression appear normal. These data suggest the presence
of another tumor suppressor gene located at 11q13 that is important in the
control of somatotrope proliferation. To establish linkage of IFS to 11q13 and to
define the candidate interval of the IFS gene, we performed haplotype and
allelotype analyses on two families with IFS. Collectively, allelic retention in
one tumor and a recombinant haplotype in an affected individual mapped the tumor
suppressor gene involved in the pathogenesis of IFS to a region of 8.6 cM between
polymorphic microsatellite markers D11S1335 and INT-2 located at chromosome
11q13.1-13.3. Maximum two-point LOD scores for five markers within this region
were 3.0 or more at theta = 0.0. As somatotropinomas are the predominant
pituitary tumor subtype associated with CNC and arise before 30 yr of age, which
is strikingly similar to the age at diagnosis for IFS, we explored the
possibility that the putative CNC genes might also contribute to the pathogenesis
of IFS. Although the genetic defect responsible for the complex is unknown, CNC
has been mapped by linkage analysis to chromosomes 2p15-16 and 17q23-24 in
different kindreds. Two-point LOD scores less than -2.0 were obtained using
marker D17S949 from chromosome 17q23-24, excluding linkage. However, LOD scores
of 2.5 were obtained for markers within 2p16-12; therefore, linkage of IFS to
chromosome 2p cannot be excluded. This report establishes linkage of the tumor
suppressor gene involved in the pathogenesis of IFS to chromosome 11q13.1-13.3
and identifies a potential second locus at chromosome 2p16-12.
PMID- 10690881
TI - Normal reproductive function in leptin-deficient patients with lipoatropic
diabetes.
AB - To further examine the relationships between leptin and female reproductive axis,
we conducted hormonal studies in two patients with lipoatropic diabetes that
occurred before puberty. Despite complete atrophy of sc and visceral adipose
tissue, menarche occurred in these two patients between 11-12 yr of age, followed
by regular menstrual cycles. One patient had been pregnant three times, giving
birth to children who did not develop the disease. In our two patients, repeated
analysis revealed leptin levels below 1 ng/mL (normal range for 20 insulin
treated diabetic women, 2-23 ng/mL for body mass index of 14-39 kg/m2; personal
data). We measured peripheral levels of estradiol, progesterone, FSH, LH, free
testosterone, and androstenedione within the first 5 days of the menstrual cycle,
and we tested the reactivity of pituitary after iv injection of 100 microg GnRH.
The variation in body temperature in the morning before arising was also
analyzed. We showed that 1) all measured levels of hormones were in the normal
range for both patients; and 2) low levels of leptin did not impair the
development of reproductive function in one patient and was associated with
normal gonadal function in both patients. We conclude that puberty and fertility
can occur despite chronic low serum levels of leptin. This suggests that leptin
is not fundamental to the maintenance of normal reproductive function in humans.
PMID- 10690882
TI - Alendronate and estrogen effects in postmenopausal women with low bone mineral
density. Alendronate/Estrogen Study Group.
AB - The bisphosphonate alendronate and conjugated equine estrogens are both widely
used for the treatment of postmenopausal osteoporosis. Acting by different
mechanisms, these two agents decrease bone resorption and thereby increase or
preserve bone mineral density (BMD). The comparative and combined effects of
these medications have not been rigorously studied. This prospective, double
blind, placebo-controlled, randomized clinical trial examined the effects of oral
alendronate and conjugated estrogen, in combination and separately, on BMD,
biochemical markers of bone turnover, safety, and tolerability in 425
hysterectomized postmenopausal women with low bone mass. In addition, bone biopsy
with histomorphometry was performed in a subset of subjects. Treatment included
placebo, alendronate (10 mg daily), conjugated equine estrogen (CEE; 0.625 mg
daily), or alendronate (10 mg daily) plus CEE (0.625 mg daily) for 2 yr. All of
the women received a supplement of 500 mg calcium daily. At 2 yr, placebo-treated
patients showed a mean 0.6% loss in lumbar spine BMD, compared with mean
increases in women receiving alendronate, CEE, and alendronate plus CEE of 6.0%
(P < 0.001 vs. placebo), 6.0% (P < 0.001 vs. placebo), and 8.3% (P < 0.001 vs.
placebo and CEE; P = 0.022 vs. alendronate), respectively. The corresponding
changes in total proximal femur bone mineral density were +4.0%, +3.4%, +4.7%,
and +0.3% for the alendronate, estrogen, alendronate plus estrogen, and placebo
groups, respectively. Both alendronate and CEE significantly decreased
biochemical markers of bone turnover, specifically urinary N-telopeptide of type
I collagen and serum bone-specific alkaline phosphatase. The alendronate plus CEE
combination produced slightly greater decreases in these markers than either
treatment alone, but the mean absolute values remained within the normal
premenopausal range. Alendronate, alone or in combination with CEE, was well
tolerated. In the subset of patients who underwent bone biopsies,
histomorphometry showed normal bone histology with the expected decrease in bone
turnover, which was somewhat more pronounced in the combination group. Thus,
alendronate and estrogen produced favorable effects on BMD. Combined use of
alendronate and estrogen produced somewhat larger increases in BMD than either
agent alone and was well tolerated.
PMID- 10690883
TI - Behavioral effects of prenatal versus postnatal androgen excess in children with
21-hydroxylase-deficient congenital adrenal hyperplasia.
AB - Systematic behavioral studies show that females with congenital adrenal
hyperplasia due to 21-hydroxylase deficiency (CAH) are masculinized and
defeminized in several ways; compared to their sisters, they play more with boys'
toys, are more likely to use aggression when provoked, and show less interest in
infants. We studied the extent to which these behavioral changes could be
attributed to high levels of androgens in the prenatal vs. postnatal periods in
23 girls with CAH, aged 3-12 yr. Sex-atypical behavior was significantly
associated with degree of inferred prenatal, but not postnatal, androgen excess;
marked boy-typical play was associated with severe salt-wasting CAH, early age at
diagnosis, and moderate genital masculinization at birth, but not with bone age
advance, concurrent or cumulative high levels of 17-hydroxyprogesterone, or
accelerated growth velocity in early childhood. Aggression and interest in
infants were not consistently associated with indicators of prenatal or postnatal
androgen excess, probably because those behaviors were measured less reliably
than was toy play. The results are consistent with the idea that behavioral
masculinization in girls with CAH results from high levels of androgens during
fetal development and not in postnatal life.
PMID- 10690884
TI - Interleukin-1 receptor antagonist ribonucleic acid and protein expression by
cultured Graves' and normal orbital fibroblasts is differentially modulated by
dexamethasone and irradiation.
AB - Recent data have indicated that orbital fibroblasts (OF) can be stimulated to
produce marked quantities of interleukin-1 receptor antagonist (IL-1RA), a
powerful inhibitor of the proinflammatory activities of interleukin-1 in the
orbital tissues in Graves' ophthalmopathy (GO). We examined whether the
beneficial effects of dexamethasone or irradiation, the two main therapeutic
modalities applied in patients with active GO, may be related to their capacity
to alter IL-1RA ribonucleic acid (RNA) and protein expression in OF. Early
passages of cultured OF were obtained from orbital connective tissue and
extraocular muscle of patients with severe active GO and five control subjects.
Modulation of the two variants of IL-1RA, intracellular IL-1RA (icIL-1RA) and
soluble IL-1RA (sIL-1RA), was studied after exposure of OF to increasing
concentrations of dexamethasone (10(-10)-(10(-6) mol/L)), the glucocorticoid
receptor antagonist RU 38486 (10(-3) mol/L), or combinations thereof.
Alternatively, cell monolayers were exposed to increasing doses of UV irradiation
(0.1-1 J/cm2) or ionizing irradiation (0.2-2 Gy). The IL-1RA gene and protein
variants were analyzed by RT-PCR, immunocytochemistry, immunoblotting, and enzyme
linked immunosorbent assay. Dexamethasone inhibited IL-1RA RNA steady state
levels in GO OF and control OF in a dose-dependent manner. Combined exposure of
OF to dexamethasone and RU 38486 completely restored baseline levels of IL-1RA
RNA. By contrast, low doses of UV and ionizing irradiation dose dependently up
regulated IL-1RA-specific transcripts in GO OF and control OF, whereas higher
doses were less effective. Immunoblotting and enzyme-linked immunosorbent assay
revealed suppression of IL-1RA immunoreactivity after treatment with
dexamethasone and enhanced expression of IL-1RA by GO OF and normal OF after low
doses of UV and ionizing irradiation. Our results indicate that, in contrast to
dexamethasone, low doses of irradiation stimulate expression of the IL-1RA gene
and protein variants in OF. Induction by irradiation of IL-1RA expression in
target cells of the orbital immune process represents an as yet unrecognized
mechanism by which orbital radiotherapy may exert some of its beneficial
therapeutic effects in patients with active GO.
PMID- 10690885
TI - Asp361Val Mutant of alkaline phosphatase found in patients with dominantly
inherited hypophosphatasia inhibits the activity of the wild-type enzyme.
AB - Hypophosphatasia is characterized by the hypomineralization of bone associated
with the mutation of the tissue-nonspecific alkaline phosphatase (TNSALP) gene.
Although the disease is usually autosomal recessive, an autosomal dominant form
is also recognized. Approximately 50 mutations have been found in the TNSALP gene
in patients with hypophosphatasia. However, the mutations identified to date do
not seem to account for the dominantly inherited form of the disease. We have
examined a German family in which the father and all 4 children were affected
with hypophosphatasia, whereas the mother was healthy. The affected members of
this family showed premature loss of deciduous teeth at or shortly before 2 yr of
age and low levels of serum ALP with elevated levels of urinary
phosphoethanolamine. DNA analysis by direct sequencing revealed a heterozygous
missense mutation that caused the conversion of amino acid Asp to Val at position
361 (D361V) in the patients. Another substitution was detected in exon 12 (Val to
Ala conversion at codon 505: V505A) in 1 allele of the mother and 3 children,
indicating no association of the substitution with the disease. Reconstruction
experiments demonstrated that the D361V mutant protein lost its enzymatic
activity and that it inhibited the function of wild-type enzyme when coexpressed
in COS-7 cells. On the other hand, the V505A mutant exhibited enzymatic
activities equal to those of the wild-type ALP. It is likely that the mutant
D361V protein forms dimers with the wild-type protein, and the protein-protein
interaction contributes to the dominant effect of the mutant D361V. The mutation
that causes D361V is the first one proven to be associated with the dominant form
of hypophosphatasia.
PMID- 10690886
TI - Intramuscular glycogen and intramyocellular lipid utilization during prolonged
exercise and recovery in man: a 13C and 1H nuclear magnetic resonance
spectroscopy study.
AB - Depletion of muscle glycogen is considered a limiting performance factor during
prolonged exercise, whereas the role of the intramyocellular lipid (IMCL) pool is
not yet fully understood. We examined 1) intramyocellular glycogen and lipid
utilization during prolonged exercise, 2) resynthesis of muscle glycogen and
lipids during recovery, and 3) changes in glycogen content between nonexercising
and exercising muscles during recovery. Subjects ran on a treadmill at submaximal
intensity until exhaustion. Glycogen concentrations were assessed in thigh, calf,
and nonexercising forearm muscle, and IMCL content was measured in soleus muscle
using magnetic resonance spectroscopy techniques. At the time of exhaustion,
glycogen depletion was 2-fold greater in calf than in thigh muscles, but a
significant amount of glycogen was left in both leg muscles. The glycogen
concentration in nonexercising forearm muscle decreased during the initial 5 h of
recovery to 73% of the baseline value. Duringthe exercise, the IMCL content
decreased to 67% and subsequently during recovery increased to 83% of the
baseline value. In summary, we found during prolonged running 1) significantly
greater muscle glycogen utilization in the calf muscle group than in the thigh
muscle group, 2) significant utilization of IMCL in the soleus muscle, and 3) a
decrease in glycogen content in nonexercising muscle and an increase in glycogen
content in recovering muscles during the postexercise phase. These latter data
are consistent with the hypothesis that there is transfer of glycogen by the
glucose-lactate and the glucose-->alanine cycle from the resting muscle (forearm)
to recovering muscles (thigh and calf) after running exercise.
PMID- 10690887
TI - Processing of procorticotropin-releasing hormone (pro-CRH): molecular forms of
CRH in normal and preeclamptic pregnancy.
AB - This study examined the different molecular forms of CRH in normal and
preeclampsia maternal plasma and protease-blocked placental extracts using
antibodies to different regions of the CRH precursor, pro-CRH. In the absence of
protease inhibitors, chromatographed normal placental extracts contained four
peaks of immunoreactivity corresponding to unprocessed approximately 19-kDa pro
CRH, its approximately 8-kDa intermediate metabolite, pro-CRH125-194, its
approximately 2.8-kDa midportion fragment, pro-CRH125-151, and 4.75-kDa CRH1-41.
However, if protease inhibitors were included in the extraction medium, only pro
CRH and pro-CRH125-194 were found. Pro-CRH processing was more extensive in
protease-blocked preeclampsia placentas than in those from normal pregnancy, with
three peaks corresponding to pro-CRH, proCRH125-194, and mature CRH1-41 peptide
found. Using quantitative competitive PCR, the messenger ribonucleic acid levels
of CRH precursor in preeclampsia placentas were 1.7-fold higher than those in
normal placentas (37.83 +/- 3.48 vs. 21.83 +/- 2.59 attomoles/microg total
ribonucleic acid, respectively; P < 0.005). Preeclampsia placentas contained
significantly more CRH1-41 cross-reactivity (4.72 +/- 1.22 pmol/g) than normal
term placentas (1.52 +/- 0.39 pmol/g; P < 0.048) extracted in medium containing
protease inhibitors. The content of pro-CRH(125+/-151)-reactive species in these
extracts followed the same pattern, with more immunoreactivity detected in
preeclampsia placentas (4.23 +/- 1.39 pmol/g) than in those from normal term
pregnancies (1.44 +/- 0.32 pmol/g; P < 0.01). Sequential plasma samples from 10
women with normal pregnancy and 5 women with preeclampsia were assayed for pro
CRH(125-151)- and CRH(1-41)-immunoreactive species In normal pregnancy, maternal
plasma CRH(1-41) immunoreactivity rose with increasing gestational age, reaching
460 +/- 48 pmol/L at term. In women with preeclampsia, CRH(1-41) levels at each
gestational age point were higher than those at the equivalent stage of normal
pregnancy. In contrast, the levels of pro-CRH(125-151)-immunoreactive species
remained barely detectable throughout normal and preeclamptic pregnancy. Both pro
CRH and CRH(1-41), but not pro-CRH(125-151), were shown to bind to the plasma CRH
binding protein. Our findings highlight the importance of protection of placental
tissue from degrading enzymes during extraction and show that most of the CRH in
the human placenta exists as unprocessed pro-CRH, with very little in the form of
CRH(1-41) except in preeclampsia. Our studies using maternal plasma indicate that
CRH(1-41) is the only one of the pro-CRH fragments studied to be maintained in
significant amounts in the maternal circulation and also the only fragment
studied for which a specific plasma binding protein exists.
PMID- 10690888
TI - Expression of oncofetal fibronectin messenger ribonucleic acid in fibroblasts in
the thyroid: a possible cause of false positive results in molecular-based
diagnosis of thyroid carcinomas.
AB - Oncofetal fibronectin (onfFN) messenger ribonucleic acid (mRNA) is abundantly
expressed in thyroid papillary and anaplastic carcinomas. These carcinomas can be
preoperatively diagnosed by the detection of onfFN mRNA in fine needle aspiration
biopsies (FNABs). However, previous reports have noted that the expression of
onfFN mRNA was observed in 3.7% of the FNABs that were diagnosed as negative
cytology. To clarify this discrepancy, we examined the expression of onfFN mRNA
in fibroblasts in the thyroid. By RT-PCR and real-time quantitative RT-PCR
analyses, we detected a high copy number of onfFN mRNA in cultured fibroblasts
obtained from the normal thyroid tissues dissected surgically. Thus, we conclude
that the contaminated fibroblasts in FNABs due to tumor necrosis or acute or
chronic inflammation may be a cause of false positive results in molecular-based
diagnosis of thyroid carcinomas.
PMID- 10690889
TI - Carbohydrate metabolism during long-term growth hormone (GH) treatment and after
discontinuation of GH treatment in girls with Turner syndrome participating in a
randomized dose-response study. Dutch Advisory Group on Growth Hormone.
AB - To assess possible side-effects of GH treatment with supraphysiological doses on
carbohydrate (CH) metabolism in girls with Turner syndrome (TS) during long term
GH treatment and after discontinuation of GH treatment, the results of oral
glucose tolerance tests and hemoglobin A1c measurements were analyzed in 68 girls
with TS participating in a randomized dose-response trial. These previously
untreated girls, aged 2-11 yr, were randomly assigned to 1 of 3 GH dosage groups:
group A, 4 IU/m2 x day (-0.045 mg/kg x day); group B, first year ,4 IU/m2 day;
thereafter, 6 IU/m2 x day (approximately 0.0675 mg/kg x day); group C, first
year, 4 IU/m2 x day; second year, 6 IU/m2 x day; thereafter, 8 IU/m2 x day
(approximately 0.090 mg/kg x day). After the first 4 yr, girls 12 yr of age or
older started with 5 microg/kg BW-day 17beta-estradiol for induction of puberty.
To assess the effects of long term high dose GH treatment on CH metabolism, the 7
yr data from the oral glucose tolerance tests in 9 girls of group C were
evaluated (group C1). To determine whether the changes in CH metabolism during GH
treatment would persist after discontinuation of GH treatment, the data for 28
girls who had reached adult height (group A, n = 9; group B, n = 10; group C, n =
9) were evaluated at baseline, after 4 yr of GH treatment, and 6 months after
discontinuation of GH. Seven-year data for group C1 showed that glucose levels
did not significantly change during GH treatment, whereas fasting insulin levels
as well as glucose-induced insulin levels increased significantly. The data for
the 28 girls who were treated with GH for a mean (SD) period of 85.3 (13.3)
months demonstrated that the GH-induced higher insulin levels decreased to values
close to or equal to pretreatment values after discontinuation of GH treatment.
Changes in CH variables were not significantly related to the GH dose. Hemoglobin
A1c levels never showed an abnormal value. The prevalence of impaired glucose
tolerance was low, and none of the girls developed diabetes mellitus. In
conclusion, long term GH treatment with dosages up to 8 IU/m2 x day in girls with
TS has no adverse effects on glucose levels, but induced higher levels of
insulin, indicating relative insulin resistance. The increased insulin levels
during long term GH treatment decreased after discontinuation of GH treatment to
values close to or equal to pretreatment values. Although the reversibility of
the effects of long term GH is reassuring, the consequence of long term
hyperinsulinism is still unknown.
PMID- 10690890
TI - Relationship between disease duration and predominant orbital T cell subset in
Graves' ophthalmopathy.
AB - We sought to determine whether the predominant orbital T helper (T(H)) cell
subset in orbital T cell clones established from patients with Graves'
ophthalmopathy (GO) might be related to disease duration. A total of 117 clones
were established from orbital adipose/connective tissues of 6 GO patients, and
cytokine production was measured in 57 CD3+CD4+ clones. T(H)1-type clones were
predominant in cultures from patients with recent onset (<2 yr) Graves'
hyperthyroidism (n = 44; TH1/TH0/TH2 = 57/29/14%) or GO (n = 53 clones;
TH1/TH0/TH2 = 47/30/23%). In contrast, TH2-type clones predominated in cultures
from patients with more remote onset (>2 yr) hyperthyroidism (n = 13; TH1/TH0/TH2
= 0/31/69%; P < 0.005) or GO (n = 4; TH1/TH0/TH2 = 0/25/75%; P = 0.05). In
addition, we established T cell clones from 1 TH1-dominant patient with recent
onset thyroid and eye disease using either IL-2 (12.5 ng/mL) alone or IL-2 plus
IL-4 (5 ng/mL) and found no shift toward recovery of TH2-type clones in the
latter. In conclusion, although the CD3+CD4+ clones characterized were not
necessarily tissue antigen specific, our findings suggest that cell-mediated (TH1
type) immune reactions may predominate in the orbit in early GO, whereas humoral
immunity (TH2-type) might play the greater role in later stages of the disease.
PMID- 10690891
TI - Human somatostatin receptor subtypes in acromegaly: distinct patterns of
messenger ribonucleic acid expression and hormone suppression identify different
tumoral phenotypes.
AB - Recently, studies using somatostatin (SRIF) analogs preferential for either the
SRIF receptor 2 (SSTR2) or the SSTR5 subtype demonstrated a variable suppression
of GH and PRL release from GH-secreting human adenomas. These data suggested the
concept of SSTR subtype specificity in such tumors. In the present study the
quantitative expression of messenger ribonucleic acid (mRNA) for the 5 SSTR
subtypes and the inhibitory effects of SRIF14; SRIF28; octreotide; the SSTR2
preferential analog, BIM-23197; and the SSTR5-preferential analog, BIM-23268, on
GH and PRL secretion were analyzed in cells cultured from 15 acromegalic tumors.
RT-PCR analysis revealed a consistent pattern of SSTR2 and SSTR5 mRNA expression.
SSTR5 mRNA was expressed at a higher level (1052 +/- 405 pg/pg glyceraldehyde-3
phosphate dehydrogenase) than SSTR2 mRNA (100 +/- 30 pg/pg glyceraldehyde-3
phosphate dehydrogenase). However, only SSTR2 mRNA expression correlated with the
degree of GH inhibition induced by SRIF14, SRIF28, and BIM-23197. The SSTR5
preferential compound inhibited GH release in only 7 of 15 cases. In cells
cultured from the 10 mixed adenomas that secreted both GH and PRL, RT-PCR
analysis revealed a consistent coexpression of SSTR5, SSTR2, and SSTR1 mRNA. In
all cases SRIF14, SRIF28, and the SSTR5-preferential analog, BIM-23268,
significantly suppressed PRL secretion, with a mean maximal inhibition of 48 +/-
4%. In contrast, the SSTR2-preferential analogs, BIM-23197 and octreotide, were
effective in suppressing PRL in only 6 of 10 cases. In cells cultured from
adenomas taken from patients partially responsive to the SRIF analog, octreotide,
partial additivity in suppressing both GH and PRL secretion was observed when the
SSTR2- and SSTR5-preferring analogs, BIM-23197 and BIM-23268, were tested in
combination. Our data show a highly variable ratio of the SSTR2 and SSTR5
transcripts, according to tumors. The SSTR2-preferring compound consistently
inhibits GH release, whereas the SSTR5-preferring compound is the main inhibitor
of PRL secretion. When both drugs are combined, the partial additivity observed
in mixed GH- plus PRL-secreting adenomas may be of interest in the therapeutic
approach of such tumors.
PMID- 10690892
TI - Plasma free fatty acids and endothelium-dependent vasodilation: effect of chain
length and cyclooxygenase inhibition.
AB - Free fatty acids (FFA) are known to interfere with glucose metabolism. Moreover,
it has been shown that they are able to impair the endothelium-dependent
vasodilation. Therefore, we sought to determine whether their negative effect on
endothelial function depends on their chain length or on their ability to modify
PG production. Fourteen normal volunteers were studied under baseline conditions
and then randomly allocated to two of the following four studies: 1) long chain
triglyceride (LCT) emulsion and heparin infusion (n = 7), 2) infusion of an
emulsion containing 56% medium chain triglycerides (MCT) and 44% LCT plus heparin
(n = 7), 3) infusion of LCT and heparin preceded by an i.v. bolus of 900 mg
lysine-salicylate (ASA; n = 7), and 4) after an i.v. bolus of ASA (n = 7). Basal
forearm blood flow (FBF), endothelium-dependent vasodilation in response to
intraarterial acetylcholine (Ach), and endothelium-independent vasodilation in
response to intraarterial nitroprusside were assessed by venous occlusion
plethysmography. Both LCT and MCT infusions significantly increased basal FBF
from 1.58 +/- 0.35 to 2.60 +/- 0.76 and 2.28 +/- 0.56 mL/min 100 mL tissue,
respectively (both P < 0.05). This increase was also observed for LCT plus
heparin, but not after ASA alone. The percent increase in FBF during Ach was
lowered during both LCT (252 +/- 34% of the ratio infused/control arm at maximal
Ach dose) and MCT (255 +/- 41%) compared to the baseline conditions (436 +/- 44%;
both P < 0.05). The response to Ach was also lower during LCT plus ASA, whereas
it was similar to baseline with ASA alone. No differences were observed in the
response to nitroprusside among the experimental conditions. In conclusion, 1)
the effect of FFA on endothelium-dependent vasodilation is independent of their
chain length; 2) both LCT and MCT increase baseline FBF, independently from
cyclooxygenase inhibition; and 3) acute ASA administration does not affect
endothelium-dependent vasodilation. The FFA effect on the endothelial response to
Ach may contribute to altered endothelial function and, hence, to the development
and progression of atherosclerotic cardiovascular disease.
PMID- 10690893
TI - Effects of cortisol and growth hormone on lipolysis in human adipose tissue.
AB - The in vitro effects of cortisol and GH on basal and stimulated lipolysis in
human adipose tissue were studied using a tissue incubation technique. After
preincubation for 3 days in control medium containing insulin, adipose tissue
pieces were exposed to cortisol for 3 days. GH was added to the cortisol
containing medium during the last 24 h (day 6). Adipocytes were then isolated,
and lipolysis was studied in the absence and presence of isoprenaline,
noradrenaline, forskolin, and N-6-monobutyryl-cAMP. Cortisol reduced the basal
rate of lipolysis (P < 0.01) and the sensitivity to isoprenaline compared to the
control values (P < 0.01). Addition of GH to the cortisol-containing medium
increased the basal rate of lipolysis (P < 0.01) and the sensitivity to
isoprenaline (P < 0.01) to the control level and increased the maximum
isoprenaline-induced lipolytic activity (P < 0.01). Similar effects were obtained
in the presence of noradrenaline. Maximum forskolin-induced lipolytic activity
was reduced after exposure of the tissue to cortisol (P < 0.05), whereas addition
of GH antagonized this effect (P < 0.01). Induction of the maximum lipolytic
activity with N-6-monobutyryl-cAMP was not influenced by the preceding hormone
exposure. Addition of GH alone during the last 24 h of incubation increased the
basal rate of lipolysis (P < 0.05) and resulted in a borderline significant
increase in the maximum isoprenaline-induced lipolytic activity (P = 0.055),
suggesting that GH induces lipolysis also in the absence of glucocorticoids.
Thus, cortisol and GH have opposite effects on the basal lipolytic activity in
human adipose tissue in vitro as well as on the sensitivity to catecholamines, GH
being the lipolytic and cortisol the antilipolytic agent. The present findings
are in agreement with in vivo observations.
PMID- 10690894
TI - Leptin, nutrition, and reproduction: timing is everything.
PMID- 10690895
TI - Circulating concentrations of nocturnal leptin, growth hormone, and insulin-like
growth factor-I increase before the onset of puberty in agonadal male monkeys:
potential signals for the initiation of puberty.
AB - The factor(s) responsible for initiating the developmental increase in nocturnal
gonadotropin-releasing hormone secretion, defining the onset of puberty, are not
known. Although signals regulating prepubertal growth seem to be obvious
candidates to control such a process, it is unclear whether prepubertal
alterations occur in these growth-related factors such that they might provide
the brain information on changing body size. Using samples analyzed previously
describing the initiation of nocturnal pulsatile LH secretion in agonadal male
monkeys (Endocrinology 139: 2774-2783, 1998), developmental changes in plasma
concentrations of leptin, GH, and insulin-like growth factor I (IGF-I) were
determined to test the hypothesis that an increase in circulating levels of one
or all of these growth-derived signals precedes the onset of puberty. Hormone
concentrations were determined in five juvenile males at 10-day intervals from
approximately 60 days before and 50 days after the initiation of pulsatile
nocturnal LH secretion. Leptin concentrations were determined in samples obtained
at 1000 and 2200 h, 36 and 48 h before the nocturnal assessment of pulsatile LH.
Mean nocturnal GH concentrations were determined from the sequential samples
collected at night. IGF-I was determined in the 1000- or 2200-h presequential
samples. Although daytime leptin concentrations did not increase developmentally,
nocturnal leptin levels increased significantly during the 30 days before the
onset of puberty. Furthermore, both nocturnal GH and IGF-I concentrations showed
a significant sustained increase from the early prepubertal period to the 30 days
preceding the onset of puberty. These data are the first to demonstrate an
increase in nocturnal leptin and GH-induced IGF-I secretion prior to the onset of
puberty in the agonadal male monkey and that these developmental changes occur
independent of the gonadal influences. These findings provide justification for
empirical investigation of the role of leptin and the GH axis, in particular IGF
I, in regulating developmental increases in pulsatile nocturnal gonadotropin
releasing hormone secretion initiating puberty in primates.
PMID- 10690896
TI - The skin produces urocortin.
AB - Since the skin produces POMC peptides, in the present work we investigated local
production of urocortin, a peptide related to CRH, the normal endogenous
stimulant for POMC. Urocortin immunoreactivity was detected by direct RIA in
extracts of human skin, mouse skin (C57BL-6 strain), cultured cells from
established lines of human melanoma and squamous cell carcinoma, human
keratinocytes (Ha-CaT), and hamster melanomas. Addition of a reverse phase high
performance liquid chromatography step before the RIA confirmed the presence of
urocortin, as the immunoreactivity eluted at the same retention time as urocortin
standard in extracts from HaCaT keratinocytes and mouse skin. Using the tandem
technique of liquid chromatography-mass spectrometry, we identified a peptide
with the same mass and retention time as the urocortin standard in human skin
extracts. The urocortin antigen could be immunolocalized to normal keratinocytes
of the epidermis and hair follicle, epithelium of sweat and sebaceous glands,
dermal skeletal muscle, and nevocytes; it was also detected in melanoma and basal
cell carcinoma cells. RT-PCR amplification of ribonucleic acid from human skin,
cultured keratinocytes, and melanoma cells showed a 145-kb fragment from the
coding region of exon 2 of the urocortin gene in all of the tested sources.
Lastly, sequencing of the amplified fragment confirmed 100% homology with the
known sequence of the urocortin gene. In conclusion, we now demonstrate that
human skin and mouse skin as well as cultured keratinocytes and melanoma cells
exhibit functional expression of the urocortin gene with actual production of
urocortin peptide.
PMID- 10690897
TI - Tumor necrosis factor-alpha promotes proliferation of endometriotic stromal cells
by inducing interleukin-8 gene and protein expression.
AB - Endometriosis, a common disease among women of reproductive age, is characterized
by the presence of endometrial-like tissue outside the uterus. We and others
showed that several cytokine levels, including interleukin-8 (IL-8) and tumor
necrosis factor-alpha (TNFalpha), are elevated in the peritoneal fluid of women
with endometriosis compared with those in women without endometriosis. We also
demonstrated that the addition of IL-8 to the culture medium stimulated the
proliferation of cultured endometriotic stromal cells. TNFalpha is a multipotent
cytokine that induces IL-8 production in various cell types. Therefore, we
hypothesized that TNFalpha may also contribute to the pathogenesis of
endometriosis by inducing the production of IL-8. To test this hypothesis, we
analyzed the peritoneal fluid concentrations of IL-8 and TNFalpha using enzyme
linked immunosorbent assay (ELISA). We observed a significant correlation between
the levels of TNFalpha and IL-8 in the peritoneal fluid of endometriosis
patients. We also obtained the endometriotic stromal cells from chocolate cyst
linings of the ovary. The expression of the receptors for TNFalpha (TNFR) was
examined by RT-PCR. We observed the expression of both TNFR-I and TNFR-II genes
in endometriotic stromal cells. The expression of IL-8 gene and protein was
analyzed by Northern blot hybridization and enzyme-linked immunosorbent assay,
respectively. TNFalpha induced the gene and protein expression of IL-8 in
endometriotic stromal cells in a dose-dependent fashion. The addition of TNFalpha
promoted the proliferation of the endometriotic stromal cells, and the
stimulatory effects of TNFalpha were abolished by adding anti-IL-8 antibody. We
demonstrated for the first time that TNFalpha stimulated proliferation of
endometriotic stromal cells through induction of IL-8 gene and protein
expression. We concluded that the TNFalpha may be one of the essential factors
for the pathogenesis of endometriosis.
PMID- 10690898
TI - Interferon-gamma induces interleukin-1 converting enzyme expression in pancreatic
islets by an interferon regulatory factor-1-dependent mechanism.
AB - Whereas nitric oxide (NO) production is associated with the toxic effect of
cytokines on rodent pancreatic beta-cells, cytokine-induced apoptosis in human
islets may occur independently of NO. The cysteine protease interleukin (IL)-1
converting enzyme (ICE) is a key proapoptotic caspase. Our aim was therefore to
analyze the effect of cytokines on ICE expression in human, rat, and mouse islets
and rat insulinoma cells. ICE messenger RNA (mRNA) expression was highly up
regulated after 6-, 24-, and 72-h exposure of human islets to interferon
(IFN)gamma, tumor necrosis factor (TNF)alpha + IFNgamma or IL-1beta + TNFalpha +
IFNgamma, paralleled by increased iNOS (the inducible form of NO synthase)
expression and NO production after exposure to the combined cytokines but not to
IFNgamma or TNFalpha + IFNgamma. Cytokine-induced NO-independent ICE
transcription was confirmed using iNOS inhibitors. Exposure of rat and mouse
islets, or rat insulinoma cells, for 24 h to IFNgamma alone or in combination
with the two other cytokines also resulted in a highly significant ICE mRNA
expression. ICE transcription was not inducible in islets from IFN regulatory
factor-1 knock-out mice, suggesting a key-role of this transcription-factor in
cytokine-mediated ICE expression in pancreatic islets. In conclusion, cytokines
and IFNgamma in particular increase ICE mRNA expression in pancreatic islet cells
and beta-cell lines, independently of NO synthesis, suggesting that ICE up
regulation may be involved in cytokine-induced NO-independent apoptosis of human
islets.
PMID- 10690899
TI - Regulated CYP19 aromatase transcription in breast stromal fibroblasts.
AB - Extraglandular estrogen synthesis mediates the proliferation of estrogen
responsive breast cancer in postmenopausal women. Aromatase, the cytochrome P450
Cyp19 enzyme, catalyzes the rate-limiting step in estrogen biosynthesis. Activity
is present in both normal and neoplastic breast tissue, and Cyp19 protein is
localized by immunohistochemistry predominantly in breast stromal fibroblasts. In
cultured breast stromal fibroblasts, both activity and Cyp19 messenger
ribonucleic acid are increased to a substantial degree by hormonal and growth
factor regulators of transcription. Transcriptional regulation of CYP19 is
complex in breast tissues, in which exon switching in the usage of alternative
first exons occurs from predominantly EI.4 in breast tissue from cancer-free
women to predominantly EI.3 and PII in breast tumors and quadrants with or
without tumor. The present study questioned whether the first exon switch occurs
as a result of an inherent difference between fibroblasts in normal and tumor
tissues or because of differences in local regulators between these tissues. To
distinguish between these two possibilities, we examined fibroblasts cultured
from breast tumor, benign breast, and reduction mammoplasty tissues for the
ability of various CYP19 transcriptional regulators to modulate first exon EI.3,
EI.4, and PII usage. A semiquantitative RT-PCR method was used to identify
transcripts containing six of the nine known CYP19 first exons. Combinations of
cAMP and Dex regulated transcription from first exons EI.3, EI.4, and PII in
fibroblasts cultured from all tissues, but not in reduction mammoplasty
epithelial cells. These results provide evidence that the fibroblasts from these
breast tissues are not inherently different in transcriptional regulation of
CYP19 first exon usage and that transcriptional regulatory molecules are likely
to mediate the exon switch phenomenon.
PMID- 10690900
TI - Androgen influences transforming growth factor-beta1 gene expression in human
adrenocortical cells.
AB - Sex steroid hormones have been shown to affect adrenocortical function and
trophism, yet little is known about androgen action in human adrenocortical
gland. In this study we examined the effects of androgens on transforming growth
factor-beta1 (TGF/beta1) production by the human adrenocortical cell line, NCI
H295, which we recently demonstrated to express androgen receptor and whose
growth is significantly reduced by dihydrotestosterone (DHT) treatment. TGFbeta1
is an important regulator of human adrenal development, with marked effects on
steroid-producing cell function, and the production of distinct TGFbeta subtypes
has been suggested to be regulated by steroid hormones in several tissues. To
address potential TGFbeta1 induction by DHT, quantitative PCR and enzyme-linked
immunoadsorbent assay were performed in NCI-H295 cells treated with DHT (from 10(
12)-10(-9) mol/L). DHT led to a significant dose-dependent increase in TGFbeta1
messenger ribonucleic acid expression and in biologically active TGFbeta1 protein
levels in the conditioned media of NCI-H295 cells, demonstrating that androgen
can induce TGFbeta1 expression and production. TGFbeta1 (10(-7)-10(-6) mol/L) was
capable of significantly reducing cell proliferation (P < 0.05) after 24 h of
treatment, as assessed by measuring [3H]thymidine incorporation in NCI-H295
cells. The addition of TGFbeta1-neutralizing antibody to cell cultures treated
with different DHT concentrations (10(-9) and 10(-10) mol/L) blocked the
inhibitory effect of TGF/beta1 on adrenocortical cell proliferation. These
findings suggest that TGFbeta1 exerts an inhibitory action on adrenocortical cell
proliferation. Therefore, it might be reasonable to suppose that DHT could also
influence human adrenocortical cell growth by involving TGFbeta1.
PMID- 10690901
TI - No evidence for linkage at candidate type 2 diabetes susceptibility loci on
chromosomes 12 and 20 in United Kingdom Caucasians.
AB - Several studies have identified evidence for linkage between type 2 diabetes and
the regions on chromosomes 12 and 20 containing the maturity-onset diabetes of
the young (MODY) genes, hepatocyte nuclear factor-1alpha (HNF-1alpha) and HNF
4alpha. Two studies examining the HNF-1alpha region have demonstrated evidence
for linkage at genome-wide levels of significance, whereas four studies examining
the HNF-4alpha locus have resulted in evidence for linkage at more suggestive
levels of significance. The demonstration of linkage to these regions in
additional patient series will strengthen the evidence that susceptibility
alleles exist at these loci. We therefore assessed the evidence for linkage to
these regions using a large cohort of United Kingdom Caucasian type 2 diabetes
affected sibling pairs. A maximum total of 315 affected full sibling pairs were
typed for microsatellite markers across the MODY regions and, in a subset of
families, for markers spanning the whole of chromosome 20. Evidence for linkage
was assessed using a multipoint, mode of inheritance-free method. Linkage
analysis did not reveal any significant evidence for excess allele sharing at any
of the regions studied. Loci contributing sibling recurrence risks, relative to
the general population risk, of 1.75 and 1.25 could be excluded for the HNF
1alpha and HNF-4alpha regions, respectively. We have not confirmed in United
Kingdom Caucasians the evidence for linkage previously reported on 12q and 20q.
Our results highlight further the problems of replicating previous positive
linkage results across different ethnic groups.
PMID- 10690902
TI - Increased major histocompatibility complex (MHC) expression in nontoxic goiters
is associated with iodide depletion, enhanced ability of the follicular
thyroglobulin to increase MHC gene expression, and thyroid autoantibodies.
AB - Recent studies suggest that thyroglobulin (TG) accumulated in the follicular
lumen of colloid nodular goiters can increase major histocompatibility complex
(MHC) class I gene expression in FRTL-5 thyrocytes. Iodide deficiency, also
present in these patients, was separately suggested to enhance thyroidal MHC
class I and class II gene expression in vivo and in vitro. To test the clinical
relevance of these observations, we examined 41 nontoxic goiters surgically
removed from patients who had compression problems. Northern analysis revealed
that there was a mean 3.9-fold increase in MHC class I expression and a 8.3-fold
increase in class II expression by comparison to 9 normal glands. In situ
hybridization showed that thyrocytes were the main source of class I and class II
transcripts; histological examination revealed that lymphocytic infiltration was
minimal to non-existent. The iodine content of the 41 nontoxic goiters was
significantly lower than in normal glands, consistent with increased MHC class I
and class II. There is also a profound accumulation of TG in the follicles of the
nontoxic goiters, and TG purified from the follicles of these glands increased
MHC class I gene expression in FRTL-5 thyroid cells significantly more than TG
from normal glands per mg protein. Nearly all patients with nontoxic goiter had
low, but significantly elevated, levels of antibodies against thyroid peroxidase
and/or against TG in their sera compared with those in normal individuals.
Moreover, there was a positive correlation between the titer of the serum
antibodies against thyroid peroxidase and against TG and MHC class I and class II
expression in the thyroid. The data support the possibility that the TG
accumulated in the follicular lumen of nontoxic goiters together with relative
iodine deficiency contributes to increased MHC expression in thyroid cells in
vivo and that increased MHC gene expression contributes to the ability of thyroid
antigens to trigger an autoimmune reaction.
PMID- 10690903
TI - Vitamin D receptor as a candidate tumor-suppressor gene in severe
hyperparathyroidism of uremia.
AB - Most chronic renal failure patients with severe refractory hyperparathyroidism
harbor at least one monoclonal parathyroid tumor, but the specific acquired
genetic defects that confer this clonal selective advantage remain poorly
understood. Somatic inactivation of the vitamin D receptor (VDR) gene could
contribute to clonal outgrowth, because a parathyroid cell containing this lesion
would have an impaired response to the antiproliferative influence of 1,25
dihydroxyvitamin D3. Furthermore, diminished expression of VDR protein has been
described in uremia-associated parathyroid tumors. Therefore, to assess VDR gene
inactivation's potential pathogenetic role in this disease, we rigorously
analyzed the VDR gene in 59 parathyroid tumors surgically resected from uremic
patients. First, Southern blotting and/or PCR analyses of 29 tumor samples from
14 genetically informative patients revealed no allelic losses at the VDR locus.
Next, direct DNA sequencing of all VDR splice junctions, associated intronic
sequences, and virtually the entire VDR-coding region for all 59 tumors revealed
no acquired mutations. Last, 37 tumor DNA samples were subjected to comparative
genomic hybridization, and no chromosomal losses in the VDR region (12cen-q12)
were observed. These observations suggest that inactivating defects within the
VDR gene do not commonly contribute to the primary pathogenesis of severe
refractory hyperparathyroidism in uremia.
PMID- 10690904
TI - Ovarian hyperthecosis in the setting of portal hypertension.
AB - Hepatocellular dysfunction and perturbed portal hemodynamics alter steroid
metabolism. Men with liver disease have gynecomastia, although women similarly
affected rarely show virilization. We report a 10-yr-old girl with portal
hypertension and shunting associated with precocious puberty and ovarian
hyperandrogenism. This was one of premature twin girls; neither had clitoromegaly
or genital ambiguity. In one child, neonatal respiratory problems led to
umbilical vein catheterization with subsequent development of portal
hypertension. Pubic hair was first noted at age 6 yr, breasts at 7 yr, and severe
acne and clitoromegaly at 10 yr. Baseline sex hormones were elevated:
androstenedione (A), 413 ng/dL; testosterone (T), 226 ng/dL; and estradiol (E2),
160 pg/mL. Liver transaminases were within the normal range, however, the
coagulation profile was mildly abnormal. Cosyntropin adrenal stimulation revealed
no steroidogenic defect. Dexamethasone suppression reduced A and T slightly. LH
releasing hormone stimulation produced a pubertal rise in LH and FSH. Pelvic
sonography showed a large right ovary with numerous follicles. Surgical
exploration revealed symmetrically enlarged ovaries with dense capsules.
Histology of ovarian wedge resections showed hyperthecosis; immunohistochemistry
showed stromal cells expressing steroidogenic enzymes and proteins. One month
postoperatively, A and T were unchanged from baseline, whereas E2 decreased to 56
pg/mL. A single dose of depot leuprolide acetate significantly reduced T.
Subsequent treatment with oral contraceptives reduced T to 50 ng/dL, and cyclical
menses occurred. We conclude that precocious puberty and ovarian hyperthecosis
were induced in this young girl by elevated circulating levels of sex hormones, a
consequence of portasystemic shunting and impaired hepatic steroid metabolism.
PMID- 10690905
TI - Molecular basis off hurthle cell papillary thyroid carcinoma.
AB - Among thyroid neoplasms, Hurthle cell tumors (HCTs) have traditionally been a
distinct diagnostic category. Hurthle cell adenomas are encapsulated follicular
lesions with benign behavior. Hurthle cell carcinomas exhibit unequivocal
capsular and/or vascular invasion; they are aggressive tumors with a poor
prognosis. Recently, Hurthle cell papillary thyroid carcinomas (PTCs) have been
identified on morphological grounds. We hypothesize that a subset of HCTs
represent PTC with clinical, histological, and immunohistochemical features based
on specific molecular events. ret/PTC gene rearrangements give rise to novel
oncogenes that are unique to PTC. We studied a group (n = 50) of HCTs for ret/PTC
gene rearrangements. Tumors were examined for papillary differentiation by light
microscopic evaluation of nuclear features, by RT-PCR for ret/PTC gene
rearrangements, and by immunohistochemistry for ret. Among 24 noninvasive tumors,
13 contained ribonucleic acid for ret/PTC-1, -2, or -3, and 9 of these were
immunoreactive for ret. Among 19 Hurthle cell carcinomas, 15 had focal nuclear
hypochromasia with grooves and/or inclusions; expressed transcripts of ret/PTC-1,
-2, or-3; and exhibited ret positivity. Tumors with ret/PTC gene rearrangements
tended to have lymph node metastases rather than hematogenous spread. Our results
indicate that a subset of HCTs exhibit features of PTC that are attributable to
specific gene rearrangements, resulting in expression of ret/PTC oncogenes. These
data support subclassification of HCTs into three groups: Hurthle cell adenomas,
Hurthle cell carcinomas, and Hurthle cell PTC.
PMID- 10690906
TI - The localization of the functional glucocorticoid receptor alpha in human bone.
AB - Glucocorticoids have well-documented effects on the skeleton, although their
mechanism of action is still poorly understood. The actions of glucocorticoids on
bone cells are mediated, in part, directly via specific receptors. The presence
of these receptors has been demonstrated in both rodent and human osteoblastic
cells in vitro, but their presence in human bone in vivo has not been reported.
In this study, we have used specific affinity purified polyclonal antibodies to
the functional glucocorticoid receptor alpha (GRalpha) to investigate its
expression in both developing and adult human bone using sections of neonatal
rib, calvarial, and vertebral bones, tibial growth plates from adolescents, and
iliac crest biopsies from adults who were to undergo liver transplantation. In
the tibial growth plates, GRalpha was predominantly expressed in the hypertrophic
chondrocytes within the cartilage. In the primary spongiosa, the receptor was
highly expressed by osteoblasts at sites of bone modeling. Within the bone
marrow, receptors were also detected in mononuclear cells and in endothelial
cells of blood vessels. In the neonatal rib and vertebrae, GRalpha was widely
distributed at sites of endochondral bone formation in resting, proliferating,
mature, and hypertrophic chondrocytes. They were also highly expressed in
osteoblasts at sites of bone modeling. At sites of intramembranous ossification
in neonatal calvarial bone and rib periosteum, GRa was widely expressed in cells
within the fibrous tissue and in osteoblasts at both the bone-forming surface and
at modeling sites. In the iliac crests from adults, GRalpha was predominantly
expressed in osteocytes. The receptors were not detected in osteoclasts. Our
results show for the first time the presence of the functional GRalpha in human
bone in situ and suggest that the actions of glucocorticoids on bone may be
mediated, in part, directly via the GR at different stages of life. The absence
of receptor expression in osteoclasts also suggests that the effects of
glucocorticoids on bone resorption may be mediated indirectly.
PMID- 10690907
TI - Alpha1 connexin 43 gap junctions are decreased in human adrenocortical tumors.
AB - Gap junctional communication disorders have been implicated in the etiology of
benign and malignant tumors. Understanding the type, distribution, and frequency
of gap junctions in adrenal disorders should provide insight into the role of gap
junctions in adrenal carcinogenesis as well as information that may be useful in
developing improved diagnosis and treatment of adrenal diseases. Using
immunocytochemical techniques, we have characterized and compared alpha1
connexins 43 gap junction protein levels in normal adrenal glands to those in
benign and malignant adrenocortical human tumors. In addition, gap junction
protein levels were studied in a human adrenal cancer cell line (H295). In both
normal and neoplastic adrenal tissues, only alpha1 connexin 43 could be detected,
whereas beta1 connexin 32 and beta2 connexin 26 were not found. In the normal
adrenal gland, the zona fasciculata was demonstrated to have the highest number
of gap junctions per cell (mean +/- SEM, 13.78 +/- 1.93). In contrast, in benign
adrenocortical adenomas, the number of gap junctions per cell compared to that
detected in normal adrenal glands was significantly reduced (mean +/- SEM, 4.6 +/
1.17; P < or = 0.05), and the lowest number was found in malignant
adrenocortical tumors (1.42 +/- 0.58; P < or = 0.05). Similarly, there were few
or no alpha1 connexin 43 gap junctions in the H295 population. There was a
progressive decrease in gap junction plaques in adrenocortical cancer cell
populations compared to those in normal cell populations. Therefore, analysis of
gap junction protein may be helpful for the differential diagnosis of benign and
malignant adrenal tumors. The induction of gap junctions in malignant cells may
provide a novel therapeutic strategy for adrenal cancer.
PMID- 10690908
TI - Estradiol amplifies interleukin-1-induced monocyte chemotactic protein-1
expression by ectopic endometrial cells of women with endometriosis.
AB - Endometriosis, one of the most frequently occurring gynecological disorders, is
estrogen dependent and is often associated with immunological changes. These
include increased macrophage activation and infiltration into the endometriotic
implants themselves as well as the peritoneal cavity where the implants often
develop. Despite the critical role estrogens play in the development of
endometriosis, the biochemical mechanisms of their action remain unclear. In the
present study we report that estradiol (E2) enhances endometriotic cell
responsiveness to the proinflammatory cytokine interleukin-1beta by up-regulating
interleukin-1-induced monocyte chemotactic protein-1 (MCP-1) expression at the
level of both protein secretion and messenger ribonucleic acid (mRNA) synthesis,
whereas progesterone had no significant effects. According to mRNA half-life
experiments, E2 action does not seem to be due to increased MCP-1 mRNA stability
but, rather, to a higher level of transcription, as shown by run-on analysis.
Interestingly, immunohistochemical analysis of MCP-1 expression in endometriotic
tissue showed intense immunostaining in both epithelial glands and stroma
regardless of the menstrual cycle phase, which is consistent with the cell
culture data and indicates that MCP-1 expression is not subject to cyclic
variation. The findings of the present study for the first time provide evidence
that E2 up-regulates, although in an indirect way, the expression of a potent
chemotactic and activating factor by ectopic endometrial cells, which may occur
locally in the inflammatory site and contribute to peritoneal macrophage
recruitment and activation, and reveal a new means of E2 action in the
pathophysiology of endometriosis.
PMID- 10690909
TI - Association of impaired phosphatidylinositol 3-kinase activity in GLUT1
containing vesicles with malinsertion of glucose transporters into the plasma
membrane of fibroblasts from a patient with severe insulin resistance and
clinical features of Werner syndrome.
AB - The purpose of this study was to examine the molecular mechanism responsible for
the defective insulin-stimulated glucose transport in cultured fibroblasts from a
patient (VH) with clinical features of Werner syndrome and severe insulin
resistance. Thus, in cells derived from VH, the subcellular distribution,
structure, functional activity, as well as plasma membrane insertion of GLUT1
glucose transporters were analyzed. Furthermore, the insulin signal transduction
pathway leading to activation of phosphatidylinositol (PI) 3-kinase as well as
components of GLUT1-containing membrane vesicles were characterized. In
fibroblasts derived from VH, GLUT1 glucose transporters were overexpressed by 8
fold in plasma membranes (PM) and by 5-fold in high density microsomes,
respectively. Exofacial photolabeling revealed that only 14% of the overexpressed
PM-GLUT1 transporters were properly inserted into the plasma membrane. The
complementary DNA structure of the patient's insulin receptor and the GLUT1
glucose transporter, the intrinsic activity of plasma membrane glucose
transporters, the tyrosine phosphorylation, as well as the protein expression of
insulin receptor substrate-1/2 and p85 alpha/beta- and p110 alpha/beta-subunits
of PI 3-kinase were normal. However, insulin-stimulated association of the p85
subunit of PI 3-kinase was defective in fibroblasts derived from VH compared to
those from controls, and this defect was associated with a reduced IRS-1
dependent activation of PI 3-kinase by 50.2% and 63.6% after incubation for 5 and
10 min with 100 nmol/L insulin, respectively. Furthermore, immunodetection of
small GTP-binding Rab proteins in subcellular membrane fractions indicated a
decreased expression of Rab4 in total cellular homogenates as well as in high
density microsomes by 70% and 58%, respectively. After preparation of GLUT1
containing vesicles, Rab4 was not detected to be a component of these vesicles.
Analysis of the PI 3-kinase in GLUT1-containing membrane vesicles revealed
insulin-dependent targeting of the p85 subunit to the vesicles immunoadsorbed
from VH and control fibroblasts. Importantly, the association of the p85 subunit
as well as the p85-immunoprecipitable PI 3-kinase activity were markedly reduced
in GLUT1-vesicles derived from the patient. In conclusion, impaired PI 3-kinase
activity in GLUT1-containing membrane vesicles derived from fibroblasts of VH is
associated with a defective docking and/or fusion process of glucose transporters
with the plasma membrane and thus might contribute to the molecular defect
causing insulin resistance in this patient.
PMID- 10690910
TI - Preoperative calcitonin levels are predictive of tumor size and postoperative
calcitonin normalization in medullary thyroid carcinoma. Groupe d'Etudes des
Tumeurs a Calcitonine (GETC).
AB - Medullary thyroid carcinoma (MTC) is a calcitonin (CT)-secreting endocrine tumor.
Although plasma CT level is a specific and sensitive marker of MTC, its
preoperative usefulness in predicting tumor size and postoperative CT
normalization has not been documented. From a nationwide database set up by the
French CT Tumor Study Group, 226 MTC patients were selected according to the
following criteria: preoperative CT level determination by an immunoradiometric
assay (normal value, < 10 pg/mL) within the 6 months prior to surgery, total
thyroidectomy and diagnosis of MTC ascertained by histological report including
tumor size. Patients were 129 females and 97 males (female/male ratio, 1.3). One
hundred and twelve patients (49.6%) had the sporadic variety of the disease, 74
(32.7%) had multiple endocrine neoplasia 2A, three (1.3%) had multiple endocrine
neoplasia 2B, and 37 (16.4%) had familial MTC. Median age at diagnosis was 44.8
yr (range, 4.9-80.1 yr). Complete neck dissection was performed in 159 patients
(70.4%). Postoperative CT normalization was ascertained by negative response of
CT to pentagastrin stimulation (< 10 pg/mL) in 94 patients. Seventy-one patients
were considered as not cured because of residual tumor tissue and/or elevated CT
levels. Median tumor size was 11.0 mm (range, 0.2-80.0 mm), significantly larger
in females (15.0 vs. 8.0 mm, P < 0.05), and in sporadic forms (15.0 vs. 7.0 mm, P
< 0.05). Tumor size was significantly correlated (r2 = 0.52, P < 0.01) with
preoperative CT levels, the relationship being more straight in familial (r2 =
0.71) than in sporadic (r2 = 0.36) forms. Furthermore, preoperative CT levels
under 50 pg/mL appeared to be predictive of postoperative CT normalization (44 of
45 patients). However, higher CT levels did not mean absence of postoperative CT
normalization (50 of 120 patients). We conclude that low preoperative CT levels
are predictive of tumor size and postoperative CT normalization.
PMID- 10690911
TI - Comment on growth hormone therapy and retinal changes mimicking diabetic
retinopathy.
PMID- 10690912
TI - Emotion and psychopathy: startling new insights.
AB - Abnormal affective response in psychopaths is conceptualized within a broad
theory of emotion that emphasizes reciprocal appetitive and defensive
motivational systems. The startle response is proposed as a specific measure of
the directional component of emotional activation. I review the literature that
indicates that criminal psychopaths do not show the expected potentiation of the
startle reflex that normally occurs during processing of aversive stimuli such as
unpleasant photographs or punishment cues. Evidence is presented to demonstrate
that this deviant response pattern is specific to individuals who display the
classic affective symptoms of psychopathy. The core emotional deviation in
psychopathy could be a deficit in fear response, which is defined as a failure of
aversive cues to prime normal defensive actions. This emotional deficit may
represent an extreme variant of normal temperament.
PMID- 10690913
TI - The effect of D-amphetamine, clonidine, and yohimbine on human information
processing.
AB - Twelve subjects were tested with D-amphetamine, yohimbine, clonidine, and a
placebo on a task with two levels of stimulus and two levels of response
complexity. The purpose of this study was to test the hypothesis that
noradrenergic drugs affect early stimulus processes. D-amphetamine speeded
reaction time (RT), clonidine slowed it, and yohimbine had no effect. D
amphetamine and yohimbine decreased N1 latency and clonidine increased it. D
amphetamine and yohimbine decreased P3 latency and clonidine increased it but, in
each case, only when latency estimates were based on single trials, not on
averages. D-amphetamine's effect on RT, not P3, as measured by the average, is
consistent with previous results. Single trial measures appear more sensitive.
Speeding of N1 and single-trial P3 data indicate that noradrenergic drugs affect
processing of early (visual) information. D-amphetamine's speeding of single
trial P3 estimates was attributed to its noradrenergic actions. Yohimbine's
speeding of P3 without changing RT is consistent with neural net (parallel)
simulations but not with a serial model. These findings support the assumption
that different neurotransmitters modulate specific cognitive processes.
PMID- 10690914
TI - Energy expenditure and motor performance relationships in humans learning a motor
task.
AB - The ability of human subjects to learn minimum energy-demanding variants of
biological motion was examined in three adult males trained to walk on hands and
feet (creep) on a motor-driven treadmill at constant speed (0.64 m/s) for 16 3
min trials. Two subjects systematically decreased oxygen consumption and heart
rate over trials. Following this acquisition phase, subjects completed walking
and creeping trials at positive and negative treadmill grades and selected a
freely chosen creeping grade that felt "most comfortable." One subject selected a
grade that was more efficient than those imposed. Oxygen-consumption curves for
walking and creeping converged with increasing positive grade, indicating that
increased grade influences the metabolic energy viability of the task (creeping
or walking). The acquisition data provide empirical support for the "principle of
least effort" and lend support to the concept of a "comfort mode" in the
execution of motor tasks.
PMID- 10690915
TI - Focusing on the N400: an exploration of selective attention during reading.
AB - In a series of two experiments, subjects read sentences wherein words were
flanked in the lower visual field by irrelevant words (i.e., flankers). The
visual angle between the words in the sentence and the flanker words was
manipulated (i.e., 0.57 degrees, 0.97 degrees, 1.37 degrees). Sentence endings
were either congruent or incongruent; incongruent endings elicited a large N400
component. Flanker effects were observed for sentence final words on
electrophysiological measures during the reading task and on subsequent
recognition memory performance for sentence final and new words. For both
measures, the flanker effect interacted with the congruency of the sentence
ending as well as the visual angle between the sentence final word and its
flanker. The largest and earliest flanker effects were observed for congruent
endings at the smallest visual angle (0.57 degrees); congruent endings and
flankers in intermediate visual angle (0.97 degrees) conditions displayed a
similar flanker-related negativity but with a longer onset latency (490 vs. 280
ms). Congruent endings and their flankers in the largest visual angle (1.57
degrees) conditions revealed no flanker effect.
PMID- 10690916
TI - Suspense and surprise: on the relationship between expectancies and P3.
AB - Few theories of the P3 component have emphasized the distinction between its
parietal and frontocentral parts. This study used a new paradigm for testing the
predictions that the parietal P3 is evoked by awaited stimuli (suspense) and the
frontal P3 by unexpected stimuli (surprise). Subjects had to make simple
responses whenever a yellow ring appeared. This signal appeared on the screen
within a clock, most frequently when the pointer was at 12 o'clock (every 6 s)
but sometimes also at other times. The suspense process should therefore have its
minimum shortly after 12 o'clock and then steadily increase until 12 o'clock, and
the parietal P3 should accordingly be smallest with stimuli shortly after 12
o'clock, then gradually increase and be largest with 12 o'clock stimuli. Further,
the stimuli presented at times other than 12 o'clock should evoke large frontal
P3s because they were unexpected. The results confirmed parts of these
predictions. A frontocentral and a parietocentral component could indeed be
discerned. The frontal P3 was largest with non-12 o'clock stimuli, whereas the
parietal P3 was large with all stimuli. The parietal result was not predicted,
but these results taken together pose more problems for the usual view, which
assumes that the parietal P3 is evoked by unexpected stimuli, than for our
assumption that the parietal P3 reflects suspense, and the frontocentral P3
reflects surprise. Generalizing to other paradigms, we assume that different
topographies of P3 in different paradigms or in different groups of subjects
might be due to different mixtures of these two components.
PMID- 10690917
TI - The effect of monocular viewing on heartbeat discrimination.
AB - In monocular viewing conditions, an activational imbalance between the cerebral
hemispheres was assumed to develop, the direction of which depends on the side of
the viewing eye. This assumption was based on the morphological differences
between the nasal and the temporal hemiretinas and on physiological data. It was
assumed that the hemisphere receiving visual information via the nasal optic
fibers, that is, the hemisphere contralateral to the viewing eye, would be the
more activated one. Because heartbeat perception is regarded as a predominantly
right hemispheric function, it was predicted that during right hemispheric
activation created by left monocular viewing heartbeat discrimination performance
would be better than during left hemispheric activation created by right
monocular viewing. This hypothesis was tested on 30 male right-handed university
students who performed a Whitehead-type heartbeat discrimination task while
viewing only with the left or with the right eye. Heartbeat perception was more
accurate when viewing with the left eye. Additionally, respiratory manipulation
during heartbeat discrimination improved performance on this task.
PMID- 10690918
TI - Nonconscious associative learning: Pavlovian conditioning of skin conductance
responses to masked fear-relevant facial stimuli.
AB - We examined the possibility of nonconscious associative learning in a context of
skin conductance conditioning, using emotional facial expressions as stimuli. In
the first experiment, subjects were conditioned to a backwardly masked angry face
that was followed by electric shock, with a masked happy face as the
nonreinforced stimulus. In spite of the effectively masked conditioned stimuli,
differential conditioned skin conductance responses were observed in a subsequent
nonmasked extinction phase. This effect could not be attributed to differential
sensitization or pseudo-conditioning. In the second experiment, the differential
responding during extinction was replicated with angry but not with happy faces
as conditioned stimuli. It was concluded that with fear-relevant facial
expressions as the conditioned stimulus, associative learning was possible even
in conditions where the subjects remained unaware of the conditioned stimulus and
its relationship to the unconditioned stimulus.
PMID- 10690919
TI - Developmental dyslexia and attention dysfunction in adults: brain potential
indices of information processing.
AB - Event-related brain potentials (ERPs) were recorded from a group of 13 men with
severe developmental dyslexia and 15 matched normal controls. Auditory and visual
stimuli, presented in separate reaction time tasks of graded difficulty, were
used to elicit ERPs. No group differences in P300 were seen under relatively
undemanding task conditions. However, as task demands increased, visual P300 was
reduced in the dyslexic men as compared with the normal readers. An Abbreviated
Conners Parent Rating Scale was used to assess retrospectively childhood symptoms
of attention-deficit hyperactivity disorder (ADHD). Additional analyses revealed
that the dyslexics with a history of many symptoms of ADHD in childhood (high
ADHD) accounted for the group differences in P300; the dyslexics with a history
of few or no such symptoms (low ADHD) were indistinguishable from the controls at
all electrode sites. Furthermore, whereas the low-ADHD dyslexics showed the same
hemispheric asymmetry in auditory P300 as did the controls (right > left),
auditory P300 was more symmetrically distributed in the high-ADHD dyslexics. The
results are interpreted as suggesting that a distinct brain organization may
characterize dyslexic men with a history of concomitant deficits in attention.
PMID- 10690920
TI - The roles of stimulus novelty and significance in determining the electrodermal
orienting response: interactive versus additive approaches.
AB - Two competing approaches for the roles of stimulus significance and novelty in
determining orienting responses (ORs) were tested and compared. According to the
first, ORs to significant stimuli are determined by sets and expectations and are
relatively independent of the contrast between the test stimulus and preceding
stimuli, whereas responses to nonsignificant test stimuli are products of a
Sokolovian match/mismatch process. According to an alternative approach, novelty
and significance contribute independently and additively to the OR. Stimulus
significance and novelty were independently manipulated in two experiments, and
the electrodermal component of the OR was measured while sequences comprising
compound pictorial or verbal stimuli were presented. Each sequence included a
test stimulus that was either significant or neutral and was preceded by several
control stimuli. Novelty was manipulated by varying the contrast between the test
and the control stimuli. The results revealing no interaction between stimulus
significance and novelty were interpreted as supporting the theory proposed by
Cati and Ben-Shakhar (1990).
PMID- 10690921
TI - Individual differences in the autonomic origins of heart rate reactivity: the
psychometrics of respiratory sinus arrhythmia and preejection period.
AB - Heart rate reactivity has been conceptualized, at least implicitly, as a
unidimensional construct ranging from low to high, reflecting individual
differences in adrenergic reactivity to daily stressors. However, an individual's
classification as high in heart rate reactivity ignores possible individual
differences in the autonomic origins of this reactivity. Sixty-eight women were
exposed to orthostatic and speech stressors to determine the psychometric
properties (postural stability, convergent and discriminant validity) of heart
rate, preejection period, and respiratory sinus arrhythmia. Results revealed that
(a) basal, stress, simple reactivity (stress - baseline), and residualized change
indices of heart rate, preejection period, and respiratory sinus arrhythmia were
stable across postures and (b) heart rate reactivity was significantly related to
preejection period and respiratory sinus arrhythmia reactivity, whereas the
latter two measures were unrelated. Reactivity classifications may therefore be
significantly improved by attention to concurrent estimates of the activity of
both autonomic branches.
PMID- 10690922
TI - Statistical mechanic prediction of non-Gomperzian ageing in extremely aged
populations.
AB - Observations of large populations of ageing organisms have suggested that the
exponential increase in the rate of age-related mortality (Gompertz rule)
declines in extreme old age, and that the mortality of the extremely long-lived
is independent of age. I show that this phenomenon is an expected outcome of
ageing being the effect of stochastic failure of highly interconnected networks
of elements with constant failure rates, and does not require the postulation of
a separate 'long-lived' population of individuals.
PMID- 10690923
TI - Satellite cell numbers in senile rat levator ani muscle.
AB - Ageing in skeletal muscle results in motor frailty and a reduced capacity for
self repair after injury. The contractile characteristics of muscle are
determined principally by the myosin heavy chain (MHC) composition of its
myofibers. During the restorative process, satellite cells play a central role.
The present study compares the levator ani muscle of very old (32 months) and
young (4 months) male WI/HicksCar rats in terms of structural integrity, MHC and
satellite cell content. Myofiber typing was carried out by indirect
immunohistochemistry using a panel of anti-MHC antibodies. Single myofibers for
nuclear enumeration were isolated by an enzymatic technique while fiber cross
sectional areas and satellite cell frequencies were determined by computerized
planimetry and electron microscopy. In both groups of rats, the myofiber
population was homogeneously MHC type IIb-reactive. Cross-sectional data
reflected a marked degree of atrophy in the muscle of the senile rats (710.05 +/-
63.6 microm2, compared with 1519.98 +/- 79.0 microm2 in young). The myofiber
population was reduced by only about 6.7% with ageing and the representation of
satellite cells, as a fraction of total sublaminal nuclei, was relatively stable
(1.15 versus 1.91% in young; P > 0.05). The results indicate that ageing had a
considerable atrophic effect on the levator ani muscle but induced neither MHC
isoform transition nor massive depletion of the satellite cell pool. They suggest
that the well-documented impairment of the restorative capacity of senile muscle
could be due more to alterations in the nature of microenvironmental cues than to
quantitative aspects of its cellular capacity to respond.
PMID- 10690924
TI - Aging affects the regeneration of the CD8+ T cell compartment in bone marrow
transplanted mice.
AB - A chimeric mouse model has been used to determine the effect of aging on the
differentiation of CD8+ T cells and on the regeneration capacity of the mature
peripheral T cell pool after radiation induced depletion. Bone marrow cells from
Thy 1.1+ mice were transplanted into lethally irradiated young or aged mice (Thy
1.2+). After 6 weeks, splenic CD8+ T cells were subjected to phenotypic and
functional examinations by flow cytometry. Both young and aged mice were able to
develop donor derived (Thy 1.1+) CD8+ T cells. Although the absolute number of T
cells was reduced in aged recipients, the ratio of CD4+ to CD8+ T cells of donor
origin was the same in young Thy 1.1+ control mice as it was in both young and
aged chimeric mice, indicating that aging has no effect on the ratio of CD4+ to
CD8+ T cells produced by the thymus. However, the percentage of CD8+ cells in the
total Thy 1.2+ (host-origin) T cell population was significantly higher in young
chimeric mice than in age-matched Thy 1.2+ control mice (P < 0.01), suggesting
that a significant over expansion of the Thy 1.2+ CD8+ subset occurred in young
mice during regeneration. The Thy 1.1+ CD8+ T cells that developed in young hosts
were of a naive phenotype with a majority of cells expressing a low level of
CD44. In contrast, the majority of those that developed in the aged host
displayed a memory phenotype with a high percentage of cells being CD44hi. In
addition, the production of IL-4 and IFN-gamma by Thy 1.1+ CD8+ T cells was
affected by the age of the host. A greater fraction of aged Thy 1.1+ CD8+ T cells
could be induced to produce either IFN-gamma or IL-4 than young CD8+ T cells.
These results suggested that the aged microenvironment has a significant effect
on newly developed CD8+ T cells and that the age of the microenvironment also
influences the regeneration capacity of CD8+ T cells.
PMID- 10690925
TI - Evidence for increased nitric oxide production in the auditory brain stem of the
aged dwarf hamster (Phodopus sungorus): an NADPH-diaphorase histochemical study.
AB - Age-related changes of the auditory system such as presbyacusis are believed to
be due, at least in part, to alterations of central structures. The superior
olivary complex (SOC), a group of interrelated brain stem nuclei, projects to a
variety of neuronal structures including the cochlea and the inferior colliculus
(IC). The soluble gas nitric oxide (NO), believed to function as a neuroactive
substance within the SOC and cochlea, is thought to be involved in ageing
processes. Since it is unknown whether NO-production is altered in the ageing
auditory system, the present study was conducted to investigate whether the
number of NO-producing cells in the SOC is changed with increasing age. The
histochemical detection of NADPH-diaphorase activity (NADPH-d), a marker for
neurons containing NOS, was utilized to investigate the numbers of NO-producing
cells in the SOC of adult and senile Djungarian dwarf hamsters (Phodopus
sungorus). Our results demonstrate that the number of stained neurons was almost
doubled in the SOC of senile hamsters. The most distinct changes were observed in
the medial nucleus of the trapezoid body. In contrast, NO-producing preganglionic
sympathetic neurons of the spinal intermediolateral nucleus, which was studied
for comparison, did not exhibit significant differences between adult and senile
animals. It is concluded that the increase of NO-production in the ageing
auditory brain stem, as revealed by our data, may be related to hearing
impairments with increasing age.
PMID- 10690926
TI - A beta and perlecan in rat brain: glial activation, gradual clearance and limited
neurotoxicity.
AB - A beta1-40 and perlecan (A beta + perlecan) were infused into rat hippocampus for
1 week via osmotic pumps. At the end of the infusion a deposit of A beta
immunoreactive material was found surrounding the infusion site. No neurons could
be identified within this A beta deposit. The neuron-free area resulting from A
beta + perlecan was significantly larger than that found after infusions of A
beta40-1 and perlecan (reverse A beta + perlecan), perlecan alone or phosphate
buffered saline vehicle. Following infusion of A beta + perlecan, the glial cells
segregated in a manner similar to that associated with compacted amyloid plaques
in Alzheimer's disease (AD). Activated microglia/macrophages were prevalent
within the A beta deposit while the perimeter of the deposit was delimited by
reactive astrocytes. Thioflavin S and Congo red staining indicated a beta-pleated
sheet conformation of the A beta deposits, implying formation of fibrils. Intact,
apparently healthy neurons were found immediately adjacent to the A beta +
perlecan deposit. In contrast, reverse A beta peptide did not form congophilic
deposits despite the presence of perlecan. Apoptotic profiles visualized with
bisbenzamide or TUNEL staining of fragmented DNA were not seen at any of the
infusion sites, yet were readily seen in hippocampal sections from animals
treated with kainic acid. At 8 weeks, A beta immunoreactivity, Thioflavin S and
Congo red staining was reduced, indicating that A beta was being cleared. There
also was no evidence of neuron loss by Nissl or TUNEL staining. The zone of
apparent necrosis did not expand between 1 and 8 weeks, and in some instances
appeared to contract. The consistency of the A beta + perlecan infusion method in
producing reliable A beta amyloid deposits permits estimates of the rate at which
fibrillar A beta amyloid can be removed from the brain, and may provide a useful
model to study this process in vivo. However, the absence of clearly identifiable
degenerating/dying neurons at the 1 or 8 week survival times suggests that either
fibrillar A beta + perlecan slowly displaced the brain parenchyma during
infusion, or neurons were killed very gradually during the process of clearing
the A beta.
PMID- 10690927
TI - Age-related changes in myelopoietic response to lipopolysaccharide in senescence
accelerated (SAM) mice.
AB - The effects of in vivo lipopolysaccharide (LPS) administration on myelopoiesis
were examined in senescence-accelerated (SAM) mice. Young mice injected with LPS
exhibited: (a) increased femoral proliferative pool size; (b) transient reduction
in femoral non-proliferative pool size and number of femoral colony forming unit
granulocyte macrophages (CFU-GMs); (c) marked increase in splenic CFU-GMs; and
(d) transient increase in S-phase of femoral CFU-GMs. The responses of old mice
after LPS administration differed from those of young mice in the following
points: (a) no recovery of the femoral non-proliferative pool or femoral CFU-GMs,
(b) less significant augmentation of the femoral proliferative pool and splenic
CFU-GMs, and (c) prolonged reduction in S-phase of femoral CFU-GM. Injection of
LPS into mice resulted in a hyperproduction of colony-stimulating activity (CSA)
in bone followed by production of colony-inhibitory activity (CIA) in young mice
and in contrast, an excessive CIA secretion from bone without an increase in CSA
levels in old mice. These imbalances in the regulatory factors derived from non
hemopoietic cells in the bones may lead to an inappropriate response of
myelopoiesis in aged SAM mice after LPS administration, which may play a key role
in infections.
PMID- 10690928
TI - The immunology of animal papillomaviruses.
AB - Papillomaviruses are species- and tissue-specific double-stranded DNA viruses.
These viruses cause epithelial tumours in many animals, including man. Typically,
the benign warts undergo spontaneous, immune-mediated regression, most likely
effected by T-cells (especially CD4, but also CD8 subsets), whereas humoral
immunity can prevent new infections. Some papillomavirus infections fail to
regress spontaneously and others progress to malignant epithelial tumours.
Additionally, the impact of these lesions is greater in immunosuppressed
individuals. Many therapies are ineffective, and there is much interest in the
potential for immunological intervention in papillomavirus infections of man and
animals. Vaccination can be achieved with 'live' virus, formalin-inactivated
virus, synthetic virus-like particles, and DNA vaccination. There has been much
recent progress in the development of such vaccines for papillomavirus infections
in the rabbit, ox and dog. Success in these animal models suggests that similar
approaches may prove useful for prophylactic or therapeutic vaccination against
the important human papillomaviruses involved in the development of cutaneous and
anogenital warts, laryngeal papillomatosis, and cervical cancer.
PMID- 10690929
TI - Differential cytochemical staining characteristics of channel catfish leukocytes
identify cell populations in lymphoid organs.
AB - This is one of the first characterizations of channel catfish (Ictalurus
punctatus) leukocytes by enzyme cytochemistry. Leukocytes demonstrated
cytoplasmic staining patterns very similar to mammalian leukocytes when stained
with acid phosphatase, alpha-naphthyl butyrate esterase, beta-glucuronidase,
alpha-naphthyl acetate esterase, Sudan Black B and anti-immunoglobulin specific
immunohistochemistry. Lymphocytes, monocytes, macrophages, neutrophils, and
surface immunoglobulin positive (surface Ig+) cells were present in channel
catfish renal hematopoietic tissue and spleen and demonstrated distinctive
cytoplasmic foci staining patterns, cytoplasmic blushing or cell membrane
staining. Monocytes, macrophages, lymphocytes and surface Ig+ cells were present
in the thymus. Thymic and splenic cellular organization appeared very similar to
these same mammalian tissues. In the thymus, acid phosphatase positive cells were
distributed throughout the parenchyma, while alpha-naphthyl butyrate esterase and
beta-glucuronidase positive cells were concentrated in the cortex and the
medulla, respectively. Surface immunoglobulin positive cells occurred in the
cortex. In the spleen, acid phosphatase positive cells were scattered throughout
the parenchyma, while alpha-naphthyl butyrate esterase positive cells were
scattered throughout the parenchyma and adjacent to splenic arterioles. Beta
glucuronidase and surface immunoglobulin positive cells were restricted to
immediately adjacent to splenic arterioles. Sudan Black B positive cells were
scattered throughout the parenchyma, while alpha-naphthyl acetate esterase
positive cells occurred adjacent to peri-arteriole lymphoid sheaths and appear
very similar to mammalian metallophils.
PMID- 10690930
TI - Identification of Ostertagia ostertagi specific cells in bovine abomasal lymph
nodes.
AB - To investigate the contribution of different bovine cell subpopulations in the
development of in vitro induced responses by Ostertagia ostertagi third larval
antigen extract (L3), bovine abomasal lymph node cell suspensions were depleted
of specific cell populations. The depleted cell suspensions were subsequently
assayed for their proliferative responses to O. ostertagi L3 antigen extract.
Proliferative responses to O. ostertagi L3 antigen extract were restricted to a
CD2+ CD4- CD8- cell population and MHC II+ cells different from B-cells were of
major importance. Depletion of CD4, CD8, CD4CD8, IgM or CD21 positive cells did
not decrease proliferation to L3 antigen extract. Depletion of gammadelta T
cells, which also comprise a subpopulation of CD2+ CD4- CD8- cells, reduced
proliferation to L3 antigen extract only in one animal. The results suggest that
either gammadelta T-cells could be involved in the proliferation or that another
as yet unidentified population is important for proliferation. The precise role
of these populations during infection with O. ostertagi and the mechanism by
which these cells may influence the host immune response are important issues
that remain to be elucidated.
PMID- 10690931
TI - Characterisation of monoclonal antibodies to ovine interleukin-6 and the
development of a sensitive capture ELISA.
AB - A purified recombinant ovine (rOv) interleukin-6 (IL-6) was used to generate
specific murine monoclonal antibodies (mAbs) and a polyclonal rabbit antisera to
this cytokine. From the 31 initial hybridoma cell lines generated, three stable
clones were established which secreted mAbs to rOvIL-6, as judged by a direct
enzyme-linked immunosorbent assay (ELISA) and Western blotting. Their specificity
was further confirmed by demonstrating that none of the mAbs recognised any of
the six other irrelevant recombinant ovine cytokines tested by direct ELISA. All
three mAbs displayed cross-reactivity with human and African green monkey IL-6 as
demonstrated by direct ELISA and Western blotting. In contrast, the polyclonal
antibodies only cross-reacted with bovine IL-6 and not with either of the human
or monkey homologues. By combining a mAb with the polyclonal antisera a
sensitive, IL-6-specific, capture ELISA was developed that had a sensitivity of
150 pg/ml. This detection system was unequivocally validated by demonstrating
that native OvIL-6 could be detected in efferent lymph draining from a stimulated
popliteal lymph node. In addition, one of the mAbs was shown to allow the
detection of OvIL-6 by intracellular cytokine staining and flow cytometry.
PMID- 10690932
TI - A standardized gating technique for the generation of flow cytometry data for
normal canine and normal feline blood lymphocytes.
AB - Flow cytometry is becoming a commonly used technique to characterize a variety of
cells. It provides a powerful application to rapidly determine the relative
percentages of T-lymphocyte subsets and B-lymphocytes. The effectiveness of its
application, however, is dependent on standardization, especially in a clinical
setting. Application of flow cytometry to veterinary diagnostics has been limited
by the unavailability of reagents and by the unstandardized characterization of
normal values using antibodies not commercially available, but typically provided
through the generosity of other researchers. This paper presents a standardized
gating protocol, and average values and ranges observed for normal canine and
feline blood lymphocytes using commercially available antibodies to cell surface
markers for CD5, CD3, CD4, CD8, MHC II, and B lymphocytes. The averages for these
markers on gated lymphocytes were as follows: Canine CD5 83.3%, Canine CD4 45.0%,
Canine CD8 28.8%, Canine MHC II 98.0%, Canine B Cell 12.9%, Canine CD4/CD8 ratio
1.87, Feline T lymphocytes 77.3%, Feline CD4 44.5%, Feline CD8 25.7%, Feline B
Cell 24.1%, Feline CD4/CD8 Ratio 1.75. Normal values were also established for a
mixed breed group of dogs, and old versus young dogs. This information will
provide researchers and clinicians with a standardized protocol for gating, which
establishes a basis for comparison between techniques, and a measure of
phenotypic percentages for flow cytometry in normal dogs and cats based on this
standardization and commercially available antibodies.
PMID- 10690933
TI - Cloning, sequencing, and analysis of cDNA encoding bovine granulocyte-colony
stimulating factor.
AB - Neutrophils play a critical role in defending against bacterial infections.
Hematopoietic growth factors are a class of regulatory cytokines that are
required for stimulation, proliferation, and differentiation of blood cells.
Granulocyte colony stimulating factor (G-CSF) is a cytokine that induces
proliferation and maturation of precursor myeloid cells in the bone marrow into
fully differentiated neutrophils. G-CSF also modulates the functional activity of
mature neutrophils. Treatment with G-CSF significantly enhances neutrophil
phagocytic activity and killing of bacteria and fungi. We have isolated and
sequenced a cDNA clone encoding bovine G-CSF (bG-CSF) from an endothelial cell
cDNA library using primers designed from ovine G-CSF. The full length cDNA is
1460 nucleotides with 585 nucleotides comprising the open reading frame. Sequence
analysis shows 95% identity with ovine, 89% with porcine, 85% with human, and 76%
with murine G-CSF. The deduced G-CSF protein consists of 174 amino acids with 95%
identity to ovine, 86% to porcine, 81% to human, and 71% to murine. The signal
peptide of G-CSF is 21 amino acids long which is nine amino acids shorter than
that of human and murine G-CSF. RT-PCR analysis shows that neither freshly
isolated nor ConA stimulated neutrophils express G-CSF mRNA. Mononuclear cells,
however, expressed G-CSF mRNA after 48 h incubation with or without ConA
stimulation.
PMID- 10690935
TI - Effect of insulin on human aortic endothelial nitric oxide synthase.
AB - It has recently been shown that insulin induces vasodilation in human arteries
and veins in vivo. This effect of insulin has been shown to be a direct one on
the human vein. In view of these observations and the fact that insulin-induced
vasodilation is impaired in insulin-resistant states like type 2 diabetes and
obesity, we have investigated the hypothesis that insulin may induce the
expression of endothelial nitric oxide synthase (e-NOS) in endothelial cells
grown from human aortae (HAECs), human lower-limb veins, and human umbilical
veins (HUVECs), and microvascular endothelial cells (MVECs) from human adipose
tissue. The expression of e-NOS was maximal in HAECs, and therefore, further
experiments were performed on these cells. When cells reached 90% confluence,
they were induced with different concentrations of insulin (0, 25, 100, and 1,000
microU/mL) for 6 days. The cells were homogenized and e-NOS expression was
examined by Western blotting. A dose-dependent induction by insulin of e-NOS in
the endothelial cells was clearly demonstrated. There was no detectable level of
the inducible NOS isoform (i-NOS), and this effect of insulin was independent of
cell proliferation. We conclude that insulin induces a dose-dependent induction
of e-NOS in human aortic cells (and possibly arterial/endothelial cells), and
this effect may contribute to the overall vasodilatory effect of insulin.
PMID- 10690934
TI - Positive reactions to common allergens in 42 atopic dogs in Japan.
AB - Clinically important allergens for the diagnosis and treatment of atopic
dermatitis vary geographically. In order to identify the most prevalent allergens
in atopic dogs in Japan, 42 dogs with a clinical diagnosis of atopy were tested
using both in vivo (intradermal skin test (IDST)) and in vitro (antigen-specific
IgE assay) allergy tests. Allergens used for IDST included 26 allergen extracts
from eight allergen groups: trees, weeds, grasses, house dust mites (HDM), molds,
foods, epithelia, and arthropods. Immunodot assay was used to measure antigen
specific IgE against 24 allergens from these eight groups and against fish such
as cod and sole. In the 42 dogs, the most common positive allergen reaction was
to HDM on both IDST (29/42 dogs or 69%) and in vitro testing (23/42 or 54.8%).
The second most frequent positive allergen reaction was to Japanese cedar pollen
(21/42 or 50.0% for IDST and 7/42 or 16.7% for in vitro testing). In both tests,
less than 20% of dogs had positive reactions to molds or foods. Positive
reactions to cat epithelia were frequently found on IDST, but rarely found on in
vitro testing. Agreement between the two tests was found in 26 instances: HDM (21
dogs), Japanese cedar pollen (five dogs) and wheat (one dog). In this study, the
two most common allergens involved in atopic dermatitis in dogs in Japan were HDM
and Japanese cedar pollen.
PMID- 10690936
TI - Insulin regulation of plasma free fatty acid concentrations is abnormal in
healthy subjects with muscle insulin resistance.
AB - This study evaluated the ability of insulin to regulate free fatty acid (FFA)
concentrations in healthy nondiabetic subjects selected to be either insulin
resistant or -sensitive on the basis of insulin-mediated glucose disposal by
muscle. Comparisons of steady-state plasma glucose (SSPG), insulin (SSPI), and
FFA concentrations were made at the end of 3 infusion periods: (1) under basal
insulin conditions (approximately 10 microU/mL), (2) in response to isoproterenol
induced stimulation of lipolysis at the same basal insulin concentration, and (3)
following inhibition of isoproterenol-induced lipolysis by a 2-fold increase in
the insulin concentration. The results showed that steady-state FFA
concentrations were significantly higher under basal conditions (360 +/- 73 v 158
+/- 36 microEq/L, P = .02), in response to isoproterenol-induced lipolysis (809
+/- 92 v433 +/- 65 microEq/L, P = .005), and following insulin inhibition of
isoproterenol-induced lipolysis (309 +/- 65 v 159 +/- 37 microEq/L, P = .06).
These differences were found despite the fact that SSPG concentrations were also
higher in insulin-resistant individuals during all 3 infusion periods. These
results demonstrate that the ability of insulin to regulate plasma FFA
concentrations is impaired in healthy subjects with muscle insulin resistance,
indicating that insulin-resistant individuals share defects in the ability of
insulin to stimulate muscle glucose disposal and to inhibit adipose tissue
lipolysis.
PMID- 10690937
TI - Effects of galanin on growth hormone and prolactin secretion in anorexia nervosa.
AB - Galanin (GAL) elicits growth hormone (GH) release in normal subjects through
interaction with hypothalamic somatostatin. GAL also stimulates GH-releasing
hormone (GHRH) secretion in vitro. In rats, GAL is able to stimulate prolactin
(PRL) release, but this effect is not clear in humans. We have thus investigated
GAL effects on GH and PRL release in patients with anorexia nervosa (AN), known
to have altered regulation of the GH-insulin-like growth factor axis and PRL
dynamics, and compared the effects of GHRH and GAL on GH and PRL secretion in AN
and normal healthy subjects. Eight women with AN (15 to 27 years; body mass index
[BMI], 17 to 19.5 kg/m2) were treated with (1) GHRH 50 microg intravenous (IV)
injection, (2) porcine GAL 500 microg infusion from -10 to +30 minutes, and (3)
135-minutes saline infusion as a control, respectively. Both peptides induced a
significant increase in plasma GH in AN patients (peak level, 27.41 +/- 5.50
microg/L after GAL and 18.97 +/- 2.67 microg/L after GHRH). When data for AN
patients and the control group were compared, GH peak levels after GAL were
significantly higher in AN patients (27.41 +/- 5.50 v 13.64 +/- 2.32 microg/L),
while GH peak levels after GHRH were not different between the 2 groups (18.97 +/
2.67 v 15.98 +/- 3.88 microg/L). PRL levels significantly increased after both
GHRH (peak, 11.70 +/- 2.80 microg/L) and GAL (peak, 18.02 +/- 5.10 microg/L)
treatment in AN patients, but not in normal subjects. We conclude that GAL
stimulates exaggerated GH release in AN patients as compared with normal
controls, suggesting a dual hypothalamic interaction via both an increase in
endogenous GHRH and a decrease in somatostatin secretion. Finally, GAL may act as
a PRL secretagogue in AN patients.
PMID- 10690938
TI - Evaluation of oxidative stress before and after control of glycemia and after
vitamin E supplementation in diabetic patients.
AB - The present study evaluates the presence of oxidative stress in the uncontrolled
diabetic state. Glycemic control reduced the oxidative stress, but total
normalization of the parameters of oxidative stress was not achieved, indicating
continued oxidant injury despite optimal control of the diabetes. Vitamin E
supplementation for 4 weeks in these patients further reduced the oxidative
stress, suggesting that vitamin E supplementation might be helpful in reducing
free-radical-induced oxidant injury.
PMID- 10690939
TI - Inhibitory effect of troglitazone on tumor necrosis factor alpha-induced
expression of monocyte chemoattractant protein-1 in human mesangial cells.
AB - Insulin resistance is one of the risk factors for the progression of
atherosclerosis and glomerulosclerosis. Recently, the new oral insulin
sensitizing agent troglitazone has been thought to offer potential in the
treatment of diabetes. If adopted for this use, it might be helpful in protecting
against the development of atherosclerosis and microvascular complications via
its improvement of insulin resistance. However, it has not yet been clarified
whether troglitazone acts directly on the vascular cells and inhibits the
progression of atherosclerosis, including glomerulosclerosis. Meanwhile, monocyte
chemoattractant protein-1 (MCP-1) is known to play an important role in the
pathogenesis of atherosclerosis and glomerulosclerosis through the induction of
monocyte migration. Therefore, we investigated the effect of troglitazone on the
expression of MCP-1 in human mesangial cells (HMCs). HMCs were treated with or
without troglitazone (1 or 10 micromol/L) in the presence or absence of tumor
necrosis factor alpha (TNF-alpha) at various concentrations (50 or 500 ng/mL),
and then MCP-1 secretion from the HMCs was measured. We found that TNF-alpha
increased the secretion of MCP-1 by 55-fold versus the control and troglitazone
significantly inhibited this TNF-alpha-induced increase in MCP-1 secretion
(49.3%). Moreover, Northern blot analysis showed that troglitazone decreased the
MCP-1 mRNA level in HMCs. We demonstrated that alpha-tocopherol also inhibited
TNF-alpha-induced MCP-1 production in HMCs, although its effects were not as
strong as troglitazone. The present study indicates that troglitazone may prevent
the progression of atherosclerosis by inhibiting MCP-1 expression in mesangial
cells.
PMID- 10690941
TI - Metabolism of [1,3-13C]glycerol-1,2,3-tris(methylsuccinate) and glycerol-1,2,3
tris(methyl[2,3-13C]succinate) in rat hepatocytes.
AB - Hepatocytes prepared from overnight-fasted rats were incubated for 120 minutes in
the presence of 2.5 mmol/L [1,3-13C]glycerol-1,2,3-tris(methylsuccinate) or
glycerol-1,2,3-tris(methyl[2,3-13C]succinate). The identification and
quantification of 13C-enriched metabolites by a recently developed method for the
deconvolution of nuclear magnetic resonance (NMR) spectra with multiplet
structures and constraints documented a virtually complete recovery of [1,3
13C]glycerol-1,2,3-tris(methylsuccinate) in 13C-labeled glycerol, lactic acid,
and glucose. In hepatocytes exposed to [1,3-13C]glycerol-1,2,3
tris(methylsuccinate), glucose was symmetrically labeled, with the vast majority
of hexose molecules being enriched with 13C on both C1 and C3 and/or C6 and C4.
The respective abundance of glucose isotopomers labeled either on both C3 and C4
or on only 1 of these 2 C atoms indicated that the triose phosphates generated
from [1,3-13C]glycerol represented 44% +/- 1% of the total amount of triose
phosphates incorporated into the hexose. In hepatocytes exposed to glycerol-1,2,3
tris(methyl[2,3-13C]succinate), the recovery of [2,3-13C]succinate, [2,3
13C]fumarate, and either double- or single-labeled malate, lactate, alanine, and
glucose accounted for about half the initial 13C content of the ester. The
majority of the glucose molecules were now labeled in both C, and C2 or C6 and
C5, with a preferential labeling of C6-C5 relative to C1-C2, the paired C6/C1 and
C5/C2 ratios averaging 1.33 +/-0.04. These findings show that glycerol-1,2,3
tris(methylsuccinate) is efficiently and extensively metabolized in hepatocytes.
They reinforce the concept that the asymmetry of glucose 13C-labeling by triose
phosphates generated from Krebs cycle intermediates is modulated by the
availability of glycerol-derived triose phosphates. Lastly, the present study
indicates that the latter triose esters, under the present experimental
conditions which do not aim at duplicating the physiological in vivo situation,
are largely directly channelled in the gluconeogenic pathway, with only a limited
intrahepatic contribution of the "indirect" pathway involving their back-and
forth interconversion to and from pyruvate.
PMID- 10690940
TI - Lipid and apolipoprotein levels and distribution in patients with
hypertriglyceridemia: effect of triglyceride reductions with atorvastatin.
AB - Atorvastatin is a new hepatic hydroxymethyl glutaryl coenzyme A (HMG-CoA)
reductase inhibitor that has been demonstrated to be efficacious in reducing both
triglyceride (TG) and cholesterol (CHOL) levels in humans. Twenty-seven (N = 27)
patients with primary hypertriglyceridemia (TG > 350 mg/dL) were studied before
and after 4 weeks on atorvastatin treatment at a dosage of either 20 (n = 16) or
80 (n = 11) mg/d. The present report examines changes in the plasma levels of
several apolipoproteins, including apolipoprotein C-II (apoC-II), apoC-III, and
apoE, after atorvastatin. Dose-dependent reductions in both CHOL (20.3% v 43.1%)
and TG (26.5% v 45.8%) for the low and high dose, respectively, have been
reported in these individuals. In addition to the reductions in apoB commonly
associated with the use of HMG-CoA reductase inhibitors, significant reductions
in apoE (37% and 49%), apoC-II (28% and 42%), and apoC-III (18% and 30%) were
observed with this agent at the 20- and 80-mg/d dosage, respectively. Using fast
protein liquid chromatography (FPLC) to fractionate whole plasma according to
particle size, the effect of atorvastatin on lipid and apolipoprotein
distribution in 20 lipoprotein fractions was also determined. Our results
indicate that after 4 weeks on atorvastatin, (1) there was a 2-fold increase in
the CHOL content as assessed by the CHOL/apoB ratio for 13 subfractions from very
low-density lipoprotein (VLDL) to small low-density lipoprotein (LDL); (2) there
was a statistically significant reduction in the percentage of plasma apoB
associated with VLDL-sized particles (30.5% v 26.8%); (3) there was a
preferential reduction in plasma apoE from non-apoB-containing lipoproteins with
treatment; (4) the losses of apoC-II and apoC-III, on the other hand, were
comparable for all lipoprotein fractions; and (5) the fraction of plasma TG
associated with HDL was increased after treatment. These changes in lipids and
apolipoproteins did not depend on the dose of atorvastatin. There was, on the
other hand, a dose-dependent reduction in cholesteryl ester transfer protein
(CETP) activity, defined as the percentage of 3H-cholesteryl oleate transferred
from high-density lipoprotein (HDL) to LDL. CETP activity was reduced by 10.3%
and 26.4% with the low and high dose of atorvastatin. Together, these composition
data would be consistent with a net reduction in the number of TG-rich
lipoproteins that may be explained by (1) a reduction in VLDL synthesis, (2) a
preferential removal of VLDL without conversion to LDL, and (3) a preferential
accelerated removal of a subpopulation of LDL.
PMID- 10690942
TI - Pathogenic factors of glucose intolerance in obese Japanese adolescents with type
2 diabetes.
AB - We attempted to identify the pathogenic factors involved in the progression to
type 2 diabetes in obese Japanese adolescents. Subjects included 18 nondiabetic
obese adolescents, 12 obese adolescents with type 2 diabetes on diet therapy, 10
obese adolescents with type 2 diabetes manifesting ketosis at onset or with a
history of treatment with hypoglycemic agents, and 26 non-obese adolescent
control subjects. The first-phase insulin response (FPIR), glucose disappearance
constant (Kg), glucose effectiveness (Sg), and insulin sensitivity (S(I)) were
obtained using an insulin-modified frequently sampled intravenous glucose
tolerance test (FSIGT) and a minimal model analysis. The disposition index (DI,
by FPIR x S(I)) was determined to assess any endogenous insulin effect. The
results showed that Kg was decreased significantly (P = .0006) with the
progression to severe diabetes in the obese groups. Although S(I) and Sg did not
differ significantly among the 3 obese groups, both parameters were significantly
lower in each obese group versus the non-obese controls. As a result of the
significant decrease in FPIR (P < .0001), the DI decreased (P = .0006) with the
progression to severe diabetes in the obese groups. In conclusion, an early
manifestation of type 2 diabetes with occasional ketosis at onset may result from
beta-cell dysfunction to glucose stimulation. This finding is demonstrated by the
relatively low FPIR to decreased S(I) in obese Japanese adolescents, as well as
the low Sg as a synergic role in glucose intolerance. The present findings from a
Japanese population for pathogenic factors aside from obesity may help us to gain
a better understanding of the progression to adolescent, early-onset, obese type
2 diabetes and its severity.
PMID- 10690943
TI - Effect of parathyroid adenoma excision on interleukin-6 (IL-6) and IL-2 receptor
levels.
AB - 1,25-Dihydroxycholecalciferol [1,25(OH)2D], besides its role in calcium and
phosphorus homeostasis, is also an important immunoregulatory molecule. Plasma
levels of this hormone may be normal or elevated in patients with primary
hyperparathyroidism. 1,25(OH)2D has been reported to inhibit production of the
cytokines interleukin-2 (IL-2) and IL-6. In the present study, we examined the
effect of parathyroid adenoma excision on serum IL-2 receptor (IL-2R) levels and
the release and production of IL-2R and IL-6 by peripheral blood lymphocytes
(each measurement was performed twice). Ten patients (5 females and 5 males aged
45 to 78 years) with primary hyperparathyroidism were enrolled in the study. The
diagnosis of primary hyperparathyroidism was based on the presence of
asymptomatic hypercalcemia, hypophosphatemia, and elevated serum intact PTH
levels. Three weeks after removal of the parathyroid adenoma, there was a
significant increase in the serum level of IL-2R, as well as the PHA-stimulated
peripheral blood lymphocyte production of IL-6 and release of IL-2R. The results
indicate that the removal of a parathyroid adenoma in patients with primary
hyperparathyroidism causes a significant increase in IL-2R and IL-6 levels. The
mechanism by which hyperparathyroidism may affect these cytokines and how they
seem related to the levels of vitamin D is discussed.
PMID- 10690944
TI - Low-dose epinephrine supports plasma glucose in fasted elderly patients with type
2 diabetes.
AB - Recent studies indicate that endogenous epinephrine provides protection against
hypoglycemia in fasted elderly patients with type 2 diabetes treated with
sulfonylureas. To establish a dose-response relationship and further characterize
this hormonal action, 10 subjects with type 2 diabetes aged 67 +/- 1.3 years and
receiving glyburide 20 mg daily were studied on 3 separate occasions. Saline
placebo, half dose epinephrine ([Epi] 0.375 microg/min), and full dose Epi (0.75
microg/min) were infused during the final 10 hours of a 28-hour fast in a paired,
randomized single-blind study to simulate physiologic epinephrine levels.
Substrate and hormonal parameters and glucose production (Rd), disposal (Rd), and
metabolic clearance rates were determined every 30 minutes. In the placebo study,
the mean decline in plasma glucose during the final 10 hours of fasting was -2.7
+/- 0.6 mmol/L, compared with -0.3 +/- 0.3 mmol/L in the half dose Epi study and
an actual increase in glucose of 1.0 +/- 0.8 mmol/L in the full dose Epi study (P
< .001). There was a similar decline in the glucose Ra in all 3 studies, and the
glucose Rd was not significantly different among the 3 study conditions. The
baseline-adjusted metabolic clearance rate of glucose was significantly decreased
during the epinephrine studies compared with the placebo study (P = .01). The
concentration of other counterregulatory hormones did not differ between the
studies. We conclude that low physiologic concentrations of epinephrine prevent
the progressive decline in plasma glucose observed during fasting in elderly
sulfonylurea-treated patients with type 2 diabetes. This finding may be
attributable to a relative insulin resistance induced by epinephrine, resulting
in a decreased rate of glucose clearance by cells.
PMID- 10690945
TI - Genome-wide search for genes related to the fat-free body mass in the Quebec
family study.
AB - Fat-free mass (FFM) consists mostly of skeletal muscle and bone tissues, and
identification of the genes and molecular mechanisms involved in the control of
FFM would have implications for the understanding of sarcopenia and potentially
osteoporesis associated with aging, as well as the response to starvation,
refeeding, anorexia, and any other conditions in which lean body mass is
important. A genome-wide search for genes related to body leanness has been
completed in the Quebec Family Study (QFS). Microsatellite markers (N = 292) from
the 22 autosomal chromosomes were typed. The mean spacing of the markers was 11.9
centimorgans (cM) (range, <0.1 to 41). FFM was calculated from percent body fat,
derived from underwater weighing, and body weight and was adjusted by regression
for age and sex effects before analysis. A maximum of 336 sib pairs or 609 pairs
of extended relatives were analyzed using single-point Haseman-Elston regression
(SIBPAL and RELPAL) and multipoint variance component (SEGPATH) linkage analyses.
Significant linkages were observed on chromosomes 15q25-q26 for a CA repeat
within the insulin-like growth factor 1 receptor (IGF1R) gene (Lod score = 3.56)
and at 18q12 with D18S877 (Lod score = 3.53) and D18S535 (Lod score = 3.58), 2
markers located 10 cM apart. A moderately significant linkage was also observed
on chromosome 7p15.3 with the marker D7S1808 (Lod score = 2.72). The most obvious
candidate genes within the regions identified by these linkages include the IGF1R
on 15q and neuropeptide Y (NPY) and growth hormone-releasing hormone (GHRH)
receptor on 7p. On 18q, the melanocortin receptor 4 (MC4R) is not likely the
candidate gene for the observed linkage. This study represents the first genome
wide search for genes that may be involved in the regulation of the lean
component of body mass in humans.
PMID- 10690946
TI - Stevioside acts directly on pancreatic beta cells to secrete insulin: actions
independent of cyclic adenosine monophosphate and adenosine triphosphate
sensitive K+-channel activity.
AB - The natural sweetener stevioside, which is found in the plant Stevia rebaudiana
Bertoni, has been used for many years in the treatment of diabetes among Indians
in Paraguay and Brazil. However, the mechanism for the blood glucose-lowering
effect remains unknown. To elucidate the impact of stevioside and its aglucon
steviol on insulin release from normal mouse islets and the beta-cell line INS-1
were used. Both stevioside and steviol (1 nmol/L to 1 mmol/L) dose-dependently
enhanced insulin secretion from incubated mouse islets in the presence of 16.7
mmol/L glucose (P < .05). The insulinotropic effects of stevioside and steviol
were critically dependent on the prevailing glucose concentration, ie, stevioside
(1 mmol/L) and steviol (1 micromol/L) only potentiated insulin secretion at or
above 8.3 mmol/L glucose (P < .05). Interestingly, the insulinotropic effects of
both stevioside and steviol were preserved in the absence of extracellular Ca2+.
During perifusion of islets, stevioside (1 mmol/L) and steviol (1 micromol/L) had
a long-lasting and apparently reversible insulinotropic effect in the presence of
16.7 mmol/L glucose (P < .05). To determine if stevioside and steviol act
directly on beta cells, the effects on INS-1 cells were also investigated.
Stevioside and steviol both potentiated insulin secretion from INS-1 cells (P <
.05). Neither stevioside (1 to 100 micromol/L) nor steviol (10 nmol/L to 10
micromol/L) influenced the plasma membrane K+ adenosine triphosphate ((K+)ATP)
sensitive channel activity, nor did they alter cyclic adenosine monophosphate
(cAMP) levels in islets. In conclusion, stevioside and steviol stimulate insulin
secretion via a direct action on beta cells. The results indicate that the
compounds may have a potential role as antihyperglycemic agents in the treatment
of type 2 diabetes mellitus.
PMID- 10690947
TI - A tale of two homocysteines--and two hemodialysis units.
AB - Pharmacologic doses of folic acid are commonly used to reduce the
hyperhomocysteinemia of end-stage renal disease (ESRD). Vitamin B12 acts at the
same metabolic locus as folic acid, but information is lacking about the specific
effects of high doses of this vitamin on homocysteine levels in renal failure. We
therefore compared the plasma homocysteine concentrations of maintenance
hemodialysis patients in two McGill University-affiliated urban tertiary-care
medical centers that differed in the use of vitamin B12 and folic acid therapy.
Patients in the first hemodialysis unit are routinely prescribed high-dose folic
acid (HI-F, 6 mg/d), whereas those in the second unit receive high-dose vitamin
B12 in the form of a monthly 1-mg intravenous injection, along with conventional
oral folic acid (HI-B12, 1 mg/d). Predialysis homocysteine was 23.4 +/- 6.8
micromol/L (mean +/- SD) in the HI-F unit and 18.2 +/- 6.1 micromol/L in the HI
B12 unit (P < .002). Postdialysis homocysteine was 14.5 +/- 4.1 in the HI-F unit
and 10.6 +/- 3.4 micromol/L in the HI-B12 unit (P = .0001). Multiple regression
analysis indicated that high-dose parenteral vitamin B12 was associated with a
lower homocysteine concentration even after controlling for the potential
confounders of sex, serum urea, serum creatinine, urea reduction ratio, and
plasma cysteine. Because this was a cross-sectional observational study, we
cannot exclude the possibility that unidentified factors, rather than the
different vitamin therapies, account for the different homocysteine levels in the
two units. Careful prospective studies of the homocysteine-lowering effect of
high-dose parenteral vitamin B12 in ESRD should be undertaken.
PMID- 10690948
TI - Insulin resistance directly correlates with increased saturated fatty acids in
skeletal muscle triglycerides.
AB - A close relationship between elevated plasma free fatty acid (FFA) levels and
insulin resistance is commonly reported in obese subjects. The aim of the present
study was to evaluate the role of intramuscular triglyceride (mTG) and FFA levels
in insulin sensitivity in 30 nondiabetic normal-weight or obese subjects (18 with
body mass index [BMI] = 21.8 +/- 3.3 kg/m2 and 12 with BMI = 34.6 +/- 2.7 kg/m2)
who underwent minor abdominal surgery. Body composition was estimated by isotopic
dilution, substrate oxidation by indirect calorimetry, and whole-body glucose
uptake by euglycemic-hyperinsulinemic clamp (EHC). Glucose uptake (M) value
negatively correlated with the MTG level (R2 = -.56, P < .0001), which was
increased in obese patients (11.6 +/- 2.2 v 6.2 +/- 1.4 micromol/g wet weight
muscle tissue, P < .0001). The TG fatty acid profile was significantly different
in the 2 groups: an increased concentration of saturated fat was present in obese
patients (unsaturated to saturated ratio, 1.89 +/- 0.40 v2.19 +/- 0.07, P <
.0001). Stepwise linear regression analysis of total mTGs and palmitic and oleic
fractions on the M value showed that only TGs and palmitic acid were
significantly related to glucose uptake (R2 = .66, P < .0001). Furthermore, among
the other anthropometric variables, only the BMI was significantly correlated
with MTGs (R2 = .71, P < .0001). In conclusion, not only the MTG concentration
but also the FFA pattern seems to affect insulin-mediated glucose uptake. A
pivotal role might be played by a high saturated fatty acid content in the TGs.
PMID- 10690949
TI - Peroxidation indices and total antioxidant capacity in plasma during
hyperhomocysteinemia induced by methionine oral loading.
AB - Hyperhomocysteinemia is a risk factor for vascular disease, although its
mechanism of action is not fully clear. Different experimental studies have
suggested that homocysteine (Hcy) exerts a pro-oxidant effect in the presence of
metal ions (Fe and Cu). To test for a similar effect in vivo, we studied plasma
markers of lipid and protein oxidation during hyperhomocysteinemia induced by an
oral methionine load. Twenty-nine subjects (aged 61 +/- 25 years; 17 women), 25
of whom underwent oral methionine (100 mg/kg) loading, were studied; in every
case, we measured total plasma Hcy, malondialdehyde (MDA), conjugated dienes
(DIE), and oxidized protein ([PTOX] carbonylic groups) in basal conditions and 4,
6, 8, and 24 hours after methionine loading. Four participants acted as controls.
In every case, we also measured total plasma antioxidant capacity (ANTOX) in
basal conditions and 8 hours after methionine loading. Eight hours after
methionine loading, plasma Hcy increased from 17.6 +/- 11.4 to 54.3 +/- 31.6
nmol/mL, PTOX from 0.33 +/- 0.18 to 0.71 +/- 0.33 nmol/mg protein, DIE from 493
+/- 163 to 590 +/-202 optical density units, and MDA from 1.66 +/- 0.81 to 2.1 +/
0.93 nmol/mL. There was a significant correlation (Spearman's r) between Hcy and
both PTOX (r = .86, P = .01) and MDA (r = .47, P < .05) 8 hours after methionine
loading. No significant modifications of the plasma parameters were found during
the observation period in controls. ANTOX at 8 hours was significantly (paired
ttest) reduced in probands (from 1.74 +/- 0.59 to 1.14 +/- 0.55 mmol/mL, P =
.014); no significant difference was observed for plasma ANTOX in controls.
Hyperhomocysteinemia due to oral methionine loading induced an increase in plasma
oxidation markers. In the absence of hyperhomocysteinemia, no significant
modifications were observed. These findings, together with the decrease in ANTOX
and the corresponding increase in total plasma Hcy, are consistent with a pro
oxidant effect of acute hyperhomocysteinemia in vivo.
PMID- 10690950
TI - production rates of testosterone in patients with Cushing's syndrome.
AB - Testosterone production rates were determined in 16 patients with Cushing's
syndrome (4 men and 12 women) using the stable-isotope dilution technique and
mass spectrometry. 1alpha,2alpha-D-Testosterone was infused for 10 hours at a
dose of 20 microg/h (men) and 0.4 microg/h (women) and blood samples were
obtained at 20-minute intervals during the last 4 hours of the observation
period. Estimated production rates in men with Cushing's syndrome were 27, 73,
150, and 180 microg/h (mean, 106 +/- 70 microg/h; healthy men [n = 12], 210 +/-
70 microg/h). In the 12 women with Cushing's syndrome, testosterone production
rates were 0.3 to 22.3 microg/h (healthy women [n = 5], 4.3 +/- 1.9 microg/h).
There was no difference in testosterone production rates in female patients with
central (n = 8) versus adrenal (n = 4) Cushing's syndrome. In summary,
testosterone production rates are subnormal or low-normal in male patients with
endogenous hypercortisolism, but not in female patients with the same disorder.
We conclude that testosterone production in men, but not in women, is
predominantly of gonadal origin and hence susceptible to a glucocorticoid-induced
suppression of gonadotropin secretion.
PMID- 10690951
TI - Changes in phosphatidylcholine fatty acid composition are associated with altered
skeletal muscle insulin responsiveness in normal man.
AB - The fatty acid composition of skeletal muscle cell membrane phospholipids (PLs)
is known to influence insulin responsiveness in man. We have recently shown that
the fatty acid composition of phosphatidylcholine (PC), and not
phosphatidylethanolamine (PE), from skeletal muscle membranes is of particular
importance in this relationship. Efforts to alter the PL fatty acid composition
in animal models have demonstrated induction of insulin resistance. However, it
has been more difficult to determine if changes in insulin sensitivity are
associated with changes in the skeletal muscle membrane fatty acid composition of
PL in man. Using nicotinic acid (NA), an agent known to induce insulin resistance
in man, 9 normal subjects were studied before and after treatment for 1 month.
Skeletal muscle membrane fatty acid composition of PC and PE from biopsies of
vastus lateralis was correlated with insulin responsiveness using a 3-step
hyperinsulinemic-euglycemic clamp. Treatment with NA was associated with a 25%
increase in the half-maximal insulin concentration ([ED50] 52.0 +/- 7.5 to 64.6
+/- 9.0 microU/mL, P < .05), consistent with decreased peripheral insulin
sensitivity. Significant changes in the fatty acid composition of PC, but not PE,
were also observed after NA administration. An increase in the percentage of 16:0
(21% +/- 0.3% to 21.7% +/- 0.4%, P < .05) and decreases in 18:0 (6.2% +/- 0.5% to
5.1% +/- 0.4%, P = .01), long-chain n-3 fatty acids (1.7% +/- 0.2% to 1.4% +/-
0.1%, P < .01), and total polyunsaturated fatty acids ([PUFAs] 8.7% +/- 0.8% to
8.0% +/- 0.8%, P < .05) are consistent with a decrease in fatty acid length and
unsaturation in PC following NA administration. The change in ED50 was
significantly correlated with the change in PUFAs (r = -.65, P < .05). These
studies suggest that the induction of insulin resistance with NA is associated
with changes in the fatty acid composition of PC in man.
PMID- 10690952
TI - Regulation of lipolysis and leptin biosynthesis in rodent adipose tissue by
growth hormone.
AB - The present study examined the effects of growth hormone (GH) on lipolysis and
leptin release by cultured adipose tissue from rats and mice incubated for 24
hours in primary culture. A stimulation of leptin release by GH in rat adipose
tissue was found in the presence of 25 nmol/L dexamethasone, and this was
accompanied by a 28% increase in leptin mRNA content. GH stimulated lipolysis in
rat adipose tissue in the presence of 0.1 nmol/L CL 316,243. In contrast, basal
lipolysis in mouse adipose tissue was stimulated by GH, but this was not
accompanied by an increase in leptin release. However, in the presence of insulin
plus triiodothyronine (T3), the stimulation of lipolysis by GH was abolished and
GH increased leptin release. These results indicate that GH can stimulate leptin
release by both mouse and rat adipose tissue in the absence of a stimulation of
lipolysis. In contrast, under conditions in which lipolysis is stimulated by GH,
there is no effect on leptin release.
PMID- 10690953
TI - Relation of plasma lipids to insulin resistance, nonesterified fatty acid levels,
and body fat in men from three ethnic groups: relevance to variation in risk of
diabetes and coronary disease.
AB - Afro-Caribbean men in the United Kingdom have a favorable lipoprotein profile and
are at low risk of coronary heart disease (CHD) compared with Europeans and South
Asians, but are at high risk of non-insulin-dependent diabetes mellitus (NIDDM)
compared with Europeans. To investigate these differences, a cross-sectional
comparison was undertaken for measures of lipoprotein metabolism, body
composition, and insulin's glucoregulatory and antilipolytic actions in 92
healthy men (42 to 61 years) of Afro-Caribbean, South Asian, or European origin.
Afro-Caribbean men were more insulin-resistant than Europeans (insulin
sensitivity [Si], 1.96 v3.01 min(-1) x microU(-1) x mL, P < .01). They
nevertheless had a more favorable lipoprotein profile, with lower levels of very
low-density lipoprotein (VLDL) cholesterol (0.21 v 0.40 mmol/L, P < .01) and
triglycerides (0.34 v 0.74 mmol/L, P < .01), lower serum total triglycerides,
higher high-density lipoprotein 2 (HDL2) cholesterol, and larger low-density
lipoprotein (LDL) particle size. These differences were not accounted for by
differences in nonesterified fatty acid (NEFA) levels, the sensitivity of
suppression of NEFA levels to insulin, or body composition. South Asians were
also more insulin-resistant than Europeans but had a less favorable lipoprotein
profile. Afro-Caribbean men in the United Kingdom are as insulin-resistant as
South Asian men but less susceptible to the lipid disturbances that
characteristically accompany insulin resistance. This favorable lipid pattern may
relate to more effective VLDL metabolism rather than a reduced supply of NEFA as
substrate for triglyceride synthesis.
PMID- 10690954
TI - Age-related differences in the secretion of calcitonin in male rats.
AB - The mechanism of hypercalcitoninemia associated with aging was investigated in
male rats. To mimic some of the hormonal changes with aging, orchidectomized
(Orch) and hyperprolactinemic rats were used to mimic the physiological status of
aging. Orch and haloperidol-induced hyperprolactinemic rats aged 3, 8, and 17
months were infused with CaCl2 and then bled from a jugular catheter following
the CaCl2 challenge. Rat thyroid gland was incubated with Locke's medium at 37
degrees C for 30 minutes. Compared with 8- and 3-month-old rats, 17-month-old
rats exhibited the lowest levels of plasma testosterone and the highest levels of
plasma prolactin (PRL) and calcitonin (CT). The release of CT in the thyroid
glands in vitro was highest in 17-month-old rats. Orchidectomy decreased rat
plasma CT and thyroid CT release in vitro. Hyperprolactinemic rats had higher
levels of plasma PRL and CT compared with control animals. The release of thyroid
CT in vitro was greater in hyperprolactinemic rats. These results suggest that
the hypersecretion of CT in 17-month-old rats may be due in part to
hyperprolactinemia.
PMID- 10690955
TI - Leptin during and after preeclamptic or normal pregnancy: its relation to serum
insulin and insulin sensitivity.
AB - Hyperleptinemia may be part of the insulin resistance syndrome. We studied serum
leptin in preeclampsia, which is an insulin-resistant state, and sought
associations between leptin and insulin or insulin sensitivity during and after
pregnancy. Twenty-two proteinuric preeclamptic women and 16 normotensive controls
were studied during the third trimester. Leptin was higher in preeclampsia (mean
+/- SE, 34.6 +/- 3.9 v 20.0 +/- 3.3 microg/L, P = .002) and correlated directly
with the level of proteinuria (r = .47, P = .03) and normal pregnancy (r = .52, P
= .04), whereas insulin sensitivity as assessed by an intravenous glucose
tolerance test showed no relationship to leptin. Leptin was 19.0 +/- 3.6 microg/L
in 14 preeclamptic women and 10.1 +/- 2.0 microg/L (P = .11) in 11 controls 3
months after delivery. Leptin correlated directly with insulin both in
preeclamptic puerperal women (r = .63, P = .02) and in controls (r = .81, P =
.003). Leptin and insulin sensitivity correlated only in preeclamptic puerperal
women (r = -.59, P = .02). In conclusion, (1) serum leptin is elevated in
preeclampsia, (2) insulin is an important determinant of serum leptin in
preeclamptic and normotensive women both during pregnancy and in the puerperium,
and (3) hyperleptinemia may be part of the insulin resistance syndrome also in
women with prior preeclampsia.
PMID- 10690956
TI - Endothelin-1 (ET-1)-potentiated insulin secretion: involvement of protein kinase
C and the ET(A) receptor subtype.
AB - Endothelin-1 (ET-1), a potent vasoconstrictor peptide of endothelial origin, is
capable of influencing hormone secretion from endocrine tissues, eg, pancreatic
islet cells. We have shown a direct stimulatory effect of ET-1 on insulin
secretion from isolated mouse islets of Langerhans. However, it is unknown as to
whether the peptide acts through specific receptors on the islet cells and which
mechanisms are involved in this insulinotropic action. We have therefore used the
specific ET(A) receptor antagonist BQ123, the ET(B) receptor agonist BQ3020, and
classic alpha- and beta-adrenergic and cholinergic antagonists. ET-1 (100 nmol/L)
stimulated insulin secretion from islets incubated at 8.3, 11.1, 16.7, and 25
mmol/L glucose (P < .05). At 3.3 mmol/L glucose, no alteration in insulin
secretion was found. The cholinergic receptor antagonist atropine (5 micromol/L)
or the adrenergic receptor antagonists propranolol (5 micromol/L) or phentolamine
(5 micromol/L) did not affect ET-1 (100 nmol/L)-stimulated insulin secretion.
BQ123 (10 pmol/L to 10 nmol/L) and BQ3020 (1 nmol/L to 1 micromol/L) had no
effect on glucose (16.7 mmol/L)-stimulated insulin secretion, but BQ123
counteracted the stimulatory effect of ET-1 (100 nmol/L) at concentrations of 1
nmol/L to 10 micromol/L (P < .01). We also studied the relative role of protein
kinase C (PKC) and a Wortmannin-sensitive pathway for ET-1-induced insulin
secretion using 12-O-tetradecanoyl phorbol-13-acetate (TPA), Calphostin C, and
Wortmannin, respectively. At 5.6 mmol/L glucose, ET-1 (100 nmol/L) had no effect
per se, whereas in the presence of 1 micromol/L TPA, which acutely stimulates
PKC, the peptide did potentiate insulin secretion (P < .05). Furthermore, the
insulinotropic effect of ET-1 at 16.7 mmol/L glucose was counteracted by the PKC
inhibitor Calphostin C (P < .05) and by downregulation of PKC by 24 hours of
exposure of islets to TPA (0.5 micromol/L, P < .05). Wortmannin (1 micromol/L)
did not alter ET-1-potentiated insulin secretion. In conclusion, our results
suggest that ET-1 acts through specific ET-1 receptors, most likely the ETA
subtype. Furthermore, PKC plays an essential role in the insulinotropic action of
ET-1 in mouse islets.
PMID- 10690957
TI - Selective consumption of thyroxine-binding globulin during cardiac bypass
surgery.
AB - A study of serum thyroid hormone binding proteins and thyroid hormone
concentrations during and after coronary artery bypass graft (CABG) surgery shows
a marked difference in the response of thyroxine binding globulin (TBG) and
transthyretin (TTR). The effects of CABG on TBG and TTR were compared in 32
patients during the day of surgery. In a few of these patients, additional
determinations were performed to 5 days. When corrected for dilution, TTR
concentrations decline gradually after surgery, with no significant decrease over
the first 24 hours. In contrast, a rapid decrease of TBG to a mean level of 60%
of the preoperative control at 12 hours after the start of surgery appears to
account for the concomitant decrease of serum T4. The rate at which the TBG
concentration decreased far exceeds the reported fractional clearance of TBG and
therefore implies accelerated consumption rather than inhibition of production.
TBG is a member of the serine protease inhibitor (SERPIN) superfamily. We propose
that its rapid consumption is due to protease cleavage at inflammatory sites.
This may explain the previously observed accumulation of thyroxine iodine at such
sites.
PMID- 10690958
TI - Changes in adenylyl cyclase isoforms as a mechanism for thyroid hormone
modulation of cardiac beta-adrenergic receptor responsiveness.
AB - Although thyroid hormones are known to modulate cardiac beta-adrenergic receptor
expression, the physiologic implications of these changes in the cardiac
manifestations of altered thyroid hormone metabolism have been disputed. This
study examined whether thyroid hormone modulates signaling via the cyclic
adenosine monophosphate (cAMP) pathway by regulating cardiac adenylyl cyclase
(AC) isoform expression. Northern blot analyses and AC enzyme assays were
performed on preparations from hypothyroid, euthyroid, and hyperthyroid rat
ventricles. Steady-state levels of cardiac AC mRNA types V and VI in hypothyroid
ventricles were 173% +/- 8% and 149% +/- 12%, respectively, of the values in
euthyroid ventricles (P < .01). This increase in AC mRNA isoforms was accompanied
by a 1.5-fold increase (P < .05) in the activation of catalytic AC by forskolin
and Mn. In contrast, the relative abundance of transcripts for types V and VI AC
was similar in hyperthyroid and euthyroid ventricles, but catalytic AC activation
by forskolin and Mn was significantly reduced by 35% in membranes obtained from
hyperthyroid ventricles. AC activation through beta-adrenergic receptor
stimulation by isoproterenol was not altered by thyroid hormone status. Thus, the
effect of thyroid hormone to repress AC catalytic activity would be anticipated
to offset the increase in beta-adrenergic receptor expression in hyperthyroidism.
These studies identify cardiac AC enzymes as important targets for thyroid
hormone-dependent regulation of signaling via the cAMP pathway, and support the
finding that cardiac adrenergic responsiveness is unaltered in thyroid disease
states.
PMID- 10690959
TI - Molecular scanning analysis of hepatocyte nuclear factor 1alpha (TCF1) gene in
typical familial type 2 diabetes in African Americans.
AB - Type 2 diabetes mellitus (T2DM) is strongly inherited, but the major genes for
this disease have been elusive. In contrast, early-onset, autosomal-dominant
diabetes results from at least 5 loci, of which hepatocyte nuclear factor 1a
(HNF1alpha or TCF1) is the most common cause. Mutations in HNF1alpha also cause
later-onset diabetes in some Caucasian populations, but the role of these
mutations has not been tested in African American populations. We used a variety
of screening methods, including both single-strand conformation polymorphism
(SSCP) analysis and dideoxy fingerprint analysis, to search for mutations in 51
African American subjects with onset of diabetes before age 50 years. Potential
mutations were confirmed by direct sequencing. We identified 21 different
variants, of which 11 were unique to African Americans. Four mutations either
altered the amino acid sequence (Gly52Ala and Gly574Ser) or were close to a
splice site (intron 1 and intron 10). A 5-nucleotide insertion in intron 1 was
present in both diabetic members of a small family, but Gly52Ala, Gly574Ser, and
the intron 10 mutation did not segregate with diabetes. Gly574Ser was present in
2 large families and 5% of controls, all of which appeared to share the same
common HNF1alpha haplotype. Surprisingly, radioactive SSCP analysis under 2 room
temperature conditions performed as well as methods using fluorescent labeling
that were expected to be more sensitive. We conclude that in African American
individuals under age 50, variation in the HNF1a gene is common but unlikely to
be a significant cause of T2DM.
PMID- 10690961
TI - Roll over Pick and tell Alzheimer the news!
PMID- 10690960
TI - Brain atrophy as a surrogate marker in MS: faster, simpler, better?
PMID- 10690962
TI - A stimulating view of human visual cortex.
PMID- 10690963
TI - Neurology in the next two decades: report of the Workforce Task Force of the
American Academy of Neurology.
PMID- 10690964
TI - HMG-CoA reductase inhibitors (statins): a promising approach to stroke
prevention.
AB - Statins represent a promising class of agents to prevent stroke. In randomized
trials of middle-aged patients with coronary artery disease, statins reduce the
incidence of stroke. The reduction in stroke may not be solely related to
cholesterol or low-density lipoprotein reduction but may involve nonsterol
mechanisms effects on endothelial cells, macrophages, platelets, and smooth
muscle cells. Statins also reduce the size of cerebral infarction in a murine
stroke model, suggesting a neuroprotective effect. The best current evidence for
stroke prevention is with pravastatin and simvastatin. Pravastatin reduces the
risk of stroke in patients with coronary artery disease and average cholesterol
levels; simvastatin reduces the risk of the combined endpoint of stroke and
transient ischemic attack in hypercholesterolemic patients with coronary artery
disease. Future studies of statins are needed in stroke populations, particularly
the elderly.
PMID- 10690965
TI - Brain embolism is a dynamic process with variable characteristics.
PMID- 10690966
TI - Intrarater and interrater reliability of the MS functional composite outcome
measure.
AB - OBJECTIVE: To assess practice effects, and intrarater and interrater reliability
of the MS functional composite (MSFC) outcome measure. BACKGROUND: To address the
poor reliability and insensitivity to change of available MS clinical rating
scales, the National MS Society's Clinical Outcomes Assessment Task Force
developed the MSFC, a multidimensional quantitative clinical outcome measure that
includes tests of leg function/ambulation (Timed 25-Foot Walk), arm function
(Nine-Hole Peg Test), and cognitive function (Paced Auditory Serial Addition
Test). METHODS: Ten patients with secondary progressive MS underwent six testing
sessions over a 2-week period. The MSFC was administered by the same examining
technician in the first five sessions and by the other technician in the sixth.
Patients were reassessed by both technicians after 6 months (sessions 7 and 8).
The MSFC score was calculated as the mean of the Z scores of the three
components. A pooled dataset derived from secondary progressive MS patients in
the placebo arms of previous clinical trials and natural history studies served
as the reference population to standardize scores. RESULTS: Practice effects were
evident initially but stabilized by the fourth administration. The intraclass
correlation coefficient (ICC) was 0.97 for the MSFC for session 4 versus session
5 (intrarater reliability). The ICC was 0.95 for session 5 versus session 6
(interrater reliability), and was 0.96 for session 7 versus session 8 when
patients were reassessed 6 months later. CONCLUSIONS: The MS functional composite
(MSFC) outcome measure had excellent intrarater and interrater reliability when
standardized procedures were used to train examining technicians and to assess
patients. Prebaseline testing sessions should be included in clinical trials
employing the MSFC to compensate for practice effects.
PMID- 10690967
TI - Progressive cerebral atrophy in MS: a serial study using registered, volumetric
MRI.
AB - OBJECTIVE: To assess the potential of registered volumetric MRI in measuring
rates of atrophy in MS. BACKGROUND: Pathologic and imaging studies suggest that
the development of permanent neurologic impairment in MS is associated with
progressive brain and spinal cord atrophy. Atrophy has been suggested as a
potential marker of disease progression. Conventional atrophy measurements
requiring manual outlining are time-consuming and subject to reproducibility
problems. Registration of serial MRI may offer a useful alternative in that
cerebral losses may be measured directly from automated subtraction of brain
volumes. METHODS: Twenty-six patients with MS and 26 age- and gender-matched
controls had two volumetric brain MR studies 1 year apart. Baseline brain and
ventricular volumes were measured using semiautomated techniques, and follow-up
scans were registered to baseline. Rates of cerebral atrophy were calculated
directly from the registered scans. RESULTS: Baseline brain volumes in the MS
group were smaller (mean difference 78 mL [95% CI 13 to 143; p = 0.02]) and
ventricular volumes greater (mean difference 12 mL [95% CI 6 to 18; p < 0.001])
than controls. The rate of cerebral atrophy in the MS group (0.8% per year) was
over twice that of controls (0.3%), and the rate of ventricular enlargement was
five times greater than the controls (1.6 versus 0.3 mL/year). CONCLUSION:
Progressive cerebral atrophy is an important feature of MS. Registration-based
measurements are sensitive and reproducible, allowing progressive atrophy to be
detected within 1 year and may have potential as a marker of progression in
monitoring therapeutic trials.
PMID- 10690968
TI - Glatiramer acetate (Copaxone) treatment in relapsing-remitting MS: quantitative
MR assessment.
AB - OBJECTIVE: To evaluate the efficacy of glatiramer acetate (GA, Copaxone; Teva
Pharmaceutical Industries, Ltd., Petah Tiqva, Israel) by MRI-based measures in
patients with relapsing-remitting (RR) MS. METHODS: Twenty-seven patients with
clinically definite RR-MS were treated with either 20 mg of GA by daily
subcutaneous self-injection (n = 14) or placebo (n = 13) for approximately 24
months. Axial dual-echo fast-spin-echo T2-weighted images and T1-weighted images
before and after gadolinium (Gd) were acquired at 1.5 tesla and transferred into
an image processing computer system. The main outcome measures were the number of
Gd-enhanced T1 and T2 lesions and their volume as well as brain parenchyma
volume. RESULTS: The values of age, disease duration, Expanded Disability Status
Scale (EDSS) score, the number of T1- and T2-weighted lesions, and their volume
were similar between GA- and placebo-receiving groups at the entry of this study.
There was a decrease in the number of T1-enhanced lesions (p = 0.03) and a
significant percent annual decrease of their volume in GA recipients compared
with those of placebo recipients. There were no significant differences between
changes in the two groups in the number of T2 lesions and their volume. The loss
of brain tissue was significantly smaller in the GA group compared with that of
the placebo group. CONCLUSIONS: These results show that GA treatment may decrease
both lesion inflammation and the rate of brain atrophy in RR-MS.
PMID- 10690969
TI - Mitral annulus calcareous brain emboli.
PMID- 10690970
TI - Familial frontotemporal dementia with ubiquitin-positive, tau-negative
inclusions.
AB - OBJECTIVE: To describe the clinical features, neuropathology, and genetic studies
in a family with autosomal dominant frontotemporal dementia (FTD). BACKGROUND:
Clinical Pick's disease, or FTD with parkinsonism, has been described in several
families linked to chromosome 17 (FTDP-17). Most of these have shown tau protein
mutations. The clinical and pathologic variations in these families resemble the
spectrum of sporadic FTD or "Pick complex." METHODS: Clinical and behavioral
analysis of the affected members with extensive histochemical and neuropathologic
description of three cases, genetic analysis of three clinically affected members
and seven at risk members to assess linkage to chromosome 17, and sequencing of
the tau gene in two patients were performed. RESULTS: The clinical pattern shows
a highly stereotypic disinhibition dementia with late extrapyramidal features,
progressive mutism, and terminal dysphagia in three generations of affected
individuals. Neuropathology showed frontotemporal atrophy, and microscopically
tau- and synuclein-negative and ubiquitin-positive neuronal inclusions, in the
background of superficial cortical spongiosis, neuronal loss, and gliosis. Tau
expression was restricted to oligodendroglia. All exons and surrounding introns
of the tau gene were sequenced, and no mutation or disease-related polymorphisms
were detected in either of two affected pedigree members. CONCLUSION: This family
with autosomal dominant frontotemporal dementia (FTD) shows no tau expression in
neurons. The ubiquitin-positive, tau-negative inclusions have been described
before in FTD with and without motor neuron disease, but not in a familial form.
The clinical and some pathologic features are similar to those of several of the
families included in descriptions of FTD with parkinsonism linked to chromosome
17, but the linkage to tau has been excluded. The defect in this family, however,
could be functionally related to tau mutations.
PMID- 10690971
TI - Memory impairment on free and cued selective reminding predicts dementia.
AB - OBJECTIVE: To estimate the relative rates of dementia in initially nondemented
subjects with and without memory impairment defined by baseline free recall from
the Free and Cued Selective Reminding (FCSR) test. BACKGROUND: Our approach to
identifying persons at high risk for future dementia is to show the presence of
memory impairment not caused by other cognitive deficits by using a memory test
that controls attention and cognitive processing. When the conditions of testing
are not adequately controlled, prediction is reduced because age-associated
memory deficits due to other cognitive deficits are confused with dementia
associated memory deficits. METHODS: Longitudinal evaluation of 264 initially
nondemented, elderly community volunteers from the Einstein Aging Study with
clinical and psychometric examinations every 12 to 18 months for up to 10 years.
MAIN OUTCOME MEASURES: Dementia was defined by an algorithmic definition that
required a Blessed Information Memory and Concentration score >8 and clinical
evidence of functional decline. RESULTS: Thirty-two incident cases of dementia
developed during follow-up. Survival analyses indicated that subjects with
impaired free recall at baseline had dementia develop (relative risk = 75.2, 95%
CI = 9.9 to 567) over 5 years of follow-up at dramatically higher rates than
subjects with intact free recall after adjusting for age, gender, and education.
CONCLUSION: Poor performance on free recall from FCSR predicts future dementia.
These findings support the existence of a preclinical phase of dementia
characterized by memory impairment, which is present for at least 5 years before
diagnosis.
PMID- 10690972
TI - Endogenous estrogen levels and Alzheimer's disease among postmenopausal women.
AB - BACKGROUND: Although several studies have suggested that hormone replacement
therapy lowers the risk of AD among postmenopausal women, few studies have
evaluated the relationship of endogenous estrogen levels and AD. The current
study investigated whether serum estrone and estradiol levels were related to the
presence of AD among postmenopausal women not currently taking hormone
replacement therapy. METHODS: Using a case-control design, we examined an
ethnically diverse sample of postmenopausal women who met National Institute of
Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and
Related Disorders Association criteria for AD (n = 50) and nondemented controls
(n = 93). All women were participants in a study of aging and dementia and were
seen consecutively between August 1997 and October 1998. RESULTS: Patients with
AD had lower estradiol (F[1,141] = 8.3, p = 0.005) levels than did normal
controls. Patients also had lower estrone levels; however, this comparison did
not quite meet significance criteria (F[1,141] = 3.6, p = 0.06). Compared to
estradiol levels >20 pg/mL, women with AD were four to six times more likely to
have levels <20 pg/mL after adjusting for age, years of education, presence of an
APOE-epsilon4 allele, ethnicity, and body mass index. There were no significant
differences in frequency of AD among women within different quartiles of estrone
after adjusting for potential confounds. CONCLUSIONS: The results of this
preliminary case-control study suggest that estradiol levels may decline
significantly in women in whom AD develops.
PMID- 10690973
TI - White matter volumes and periventricular white matter hyperintensities in aging
and dementia.
AB - OBJECTIVE: To determine the relationship between MRI periventricular white matter
hyperintensities, cerebral white matter volumes, neuropathologic findings, and
cognitive status in aged individuals. BACKGROUND: The significance of
periventricular white matter hyperintensities seen on MR images in aged
individuals remains controversial. The Nun Study is a longitudinal cohort aging
study in which all 678 initially enrolled participants agreed to autopsy
neuropathologic examination. METHODS: We used MRI to measure white matter volumes
of the cerebral hemispheres in 52 formaldehyde-fixed brains for correlation with
white matter and neocortical pathology, postmortem MRI observations, and
cognitive measures. RESULTS: Reduced white matter volume is associated with
dementia, but periventricular white matter hyperintensities were not related to
white matter volume, stroke, or dementia. CONCLUSIONS: Our results do not support
the hypothesis that periventricular hyperintensities seen on MR images have
deleterious consequences in these aged individuals.
PMID- 10690974
TI - Pure hippocampal sclerosis: a rare cause of dementia mimicking Alzheimer's
disease.
AB - OBJECTIVES: To identify patients with pure hippocampal sclerosis (HS) as a cause
of dementia, to determine whether they have had histories of hypotension or
hypoxia, and to compare the clinical features of patients with pure HS with a
control group of AD patients without HS. METHODS: In a retrospective study, the
authors reviewed all 1771 cases received in their dementia brain bank from 1978
through 1996 to identify those patients with pure HS, defined as severe
degeneration and gliosis of the CA1 sector and subiculum of the hippocampal
formation in the absence of other significant dementing disease such as
Alzheimer's changes. The control group included all patients received during the
same period with severe AD without HS, infarcts, or other dementing disease.
RESULTS: Seven pure HS cases (0.4%) were identified. None had any episodes of
syncope, hypotension, or hypoxia reported in association with dementia onset. Six
had memory loss as the primary presenting symptom, and all became progressively
demented. Forty-five AD patients without HS were identified for the control
group. There were no clear clinical differences between the two groups with
regard to sex, age at onset, risk factors for vascular disease, symptoms of
cerebrovascular disease, treatment with tranquilizing medications, treatment for
depression, or nursing home placement. There was a tendency for heart disease to
be more prevalent and the duration of illness to be shorter in the patients with
pure HS. CONCLUSIONS: Pure hippocampal sclerosis (HS) occurred in only 0.4% of
our dementia patients. Clinically, the seven patients with pure HS were similar
to our AD control group. Further research is needed to determine the causes of HS
and why HS appears to mimic AD.
PMID- 10690975
TI - Mapping of functional organization in human visual cortex: electrical cortical
stimulation.
AB - OBJECTIVES: To investigate the pattern of functional organization in the human
visual cortex through electrical cortical stimulation. METHODS: Electrical
cortical stimulation was applied to the occipital cortex and adjacent cortices
using subdural grid electrodes in 23 epilepsy patients. Diverse visual responses
were recorded. These responses were divided into different categories according
to the specific response modalities, such as form, color, and motion. Form visual
responses were further subdivided into simple, intermediate, and complex
responses. The cortical localization of subdural electrodes was identified using
MRI-CT coregistration. The cortical distribution of different visual responses
was projected into three-dimensional surface renderings of the brain. The
distribution and frequency of subdural electrodes showing different visual
responses were quantified by calculating the percentage of the number of
electrodes showing one specific type of visual response at the corresponding
anatomic region to the total number of electrodes in all brain regions that
produced the same response. RESULTS: Simple form responses were obtained mostly
at the occipital pole and the inferior occipital gyrus (47.4%) and the striate
cortex (42.4%). Intermediate form responses occurred mainly on the peristriate
cortex (52.5%) and the lateral occipital (28.0%) and fusiform gyri (19.5%).
Complex forms were produced by stimulation of the basal temporo-occipital region
(57.6%) and the lateral temporal or lateral temporo-occipital junctional region
(42.4%). Color responses occurred on the basal occipital area, mostly at the
fusiform (40.0%) and lingual gyri (36.0%). Moving sensations were evoked by
stimulation of the basal temporo-occipital (28.4%) and the mesial parieto
occipital or temporo-parieto-occipital junctional regions (23.9%). CONCLUSIONS:
Different modalities of vision, such as form, color, and moving sensation,
appeared to be distributed and organized in different areas of the human visual
cortex.
PMID- 10690976
TI - Palinopsia and polyopia in the absence of drugs or cerebral disease.
AB - OBJECTIVE: To report the occurrence of palinopsia and polyopia in patients who
neither used drugs nor had diseases of the cerebral hemispheres, a group in which
these visual symptoms have not been reported. METHOD: The patient records in the
database of an academic neuro-ophthalmology unit were reviewed. RESULTS:
Seventeen patients were identified in the database with the diagnosis of
palinopsia or polyopia, of whom eight had diseases of the cerebral hemispheres,
leaving nine patients for analysis. No patients with a history of drug toxicity
were identified. In one patient the symptoms presented during an initial episode
of demyelinative optic neuritis in the absence of clinical or laboratory evidence
of cerebral lesions. In another patient they developed immediately after laser
treatment of diabetic macular edema. A third patient developed the symptoms in
association with visual loss from Leber's hereditary optic neuropathy. The other
six patients were healthy individuals. CONCLUSION: Palinopsia and related visual
symptoms can occur in otherwise healthy individuals and in patients with disease
apparently confined to the eye or the optic nerve.
PMID- 10690977
TI - Dissociation of smooth pursuit and vestibulo-ocular reflex cancellation in SCA-6.
AB - OBJECTIVE: To study gaze in SCA-6 patients during pursuit and passive whole-body
rotation. BACKGROUND: Smooth pursuit and vestibularly induced eye movements
interact to maintain the accuracy of eye movements in space (i.e., gaze).
Previous studies have implicated the cerebellum, particularly the floccular lobe
and dorsal vermis, in the control of gaze velocity during pursuit and vestibulo
ocular reflex (VOR) cancellation. SCA-6 has recently been identified genetically
and characterized as pure cerebellar ataxia that affects the cerebellar cortex
selectively. METHODS: Using infrared oculography, eye movements of five SCA-6
patients and five age-matched normal control subjects were recorded during
sinusoidal pursuit and passive whole-body rotation in the horizontal plane
(amplitude, +/- 10 deg; frequency, 0.2 Hz). Eye and gaze gain (eye and gaze
velocity/stimulus velocity) were calculated after deleting saccades. RESULTS: Eye
gain of all SCA-6 patients during pursuit was significantly lower than those of
the control subjects (mean +/- SD, 0.26+/-0.06 versus 0.91+/-0.07). In contrast,
eye gain of the patients was not significantly different from that of the control
subjects either during VOR cancellation, when the subjects tracked a target that
moved with the same amplitude and phase, like a chair (0.21+/-0.05 versus 0.12+/
0.07), or during visually enhanced VOR (x1), when the target remained stationary
in space (0.85+/-0.06 versus 0.95+/-0.05). Moreover, there was no significant
difference in mean VOR gain in total darkness between the two groups. Gaze gain
of patients (0.26+/-0.06 versus 0.81+/-0.06) but not control subjects (0.91+/
0.07 versus 0.88+/-0.08), was significantly different during pursuit and VOR
cancellation. CONCLUSION: SCA-6 patients show dissociation in the control of gaze
tracking during smooth pursuit and VOR cancellation.
PMID- 10690978
TI - Neuropsychological and clinical correlates of antisaccade task performance in
schizophrenia.
AB - OBJECTIVES: To elucidate pathophysiologic mechanisms involved in abnormal
antisaccade task performance in schizophrenia by investigating a possible
relationship among antisaccade task performance, neuropsychological test results,
and symptomatology in a group of young patients with recent-onset schizophrenia;
to compare the effects of olanzapine and risperidone on antisaccades and
reflexive saccades. BACKGROUND: Patients with schizophrenia consistently perform
worse than controls on the antisaccade task in which the subject is required to
inhibit a reflexive saccade to a suddenly appearing visual target and look in the
opposite direction. METHODS: In 37 young (mean age 21 years), medicated patients
with recent-onset schizophrenia the authors assessed antisaccades, reflexive
saccades, neuropsychological test performance, and symptomatology. A subgroup of
18 patients was treated with olanzapine, and 15 patients were treated with
risperidone. Reflexive-saccade and antisaccade task results were compared with
those obtained in 13 control subjects. RESULTS: The antisaccade error rate was
significantly higher in the patients than in the control subjects. In the
patients, poor working memory function was related to increased antisaccade error
rate. Severity of disorganization symptoms at intake was related to prolonged
mean latency of the correct antisaccades. Patients on risperidone had a prolonged
mean latency in the reflexive saccade task compared with patients using
olanzapine. CONCLUSIONS: Abnormal antisaccade task performance is already present
in early schizophrenia and may reflect working memory dysfunction. In future
studies, medication effects should be considered in interpreting eye movement
test results of patients with schizophrenia.
PMID- 10690979
TI - Randomized pilot trial of postoperative aspirin in subarachnoid hemorrhage.
AB - OBJECTIVE: To assess the safety and feasibility of a clinical trial on the
effectiveness of acetylsalicylic acid (ASA) in subarachnoid hemorrhage (SAH).
BACKGROUND: Several studies have indicated that increased platelet activity might
be involved in the pathogenesis of delayed cerebral ischemia (DCI) after SAH.
METHOD: Fifty patients who had early surgery (< or =4 days) for a ruptured
aneurysm were enrolled in this randomized, double-blind, placebo-controlled
trial. Trial medication, consisting of suppositories with 100 mg ASA versus
placebo, was started immediately after surgical clipping of the aneurysm and
continued for 21 days. End points were functional outcome and quality of life at
4 months, clinical deterioration after operation, development of DCI, hypodense
lesion on postoperative CT, and hemorrhagic complications. RESULTS: One-third of
all patients with aneurysmal SAH were eligible for the trial. Fifteen of 26
patients receiving placebo deteriorated clinically versus 10 of 24 patients
receiving ASA; 4 patients in each group deteriorated from DCI. Postoperative
hypodensities on CT were observed in 27 patients, distributed equally in both
groups. Functional outcome and quality-of-life scores were slightly in favor of
patients who had received ASA, but not to a significant degree (p = 0.22). Two
patients in the ASA group had an asymptomatic hemorrhagic complication, and one
patient in the placebo group had a fatal and another a symptomatic hemorrhagic
complication. CONCLUSION: This pilot study shows that a clinical trial of
acetylsalicylic acid (ASA) in subarachnoid hemorrhage (SAH) is feasible and
probably safe. The effectiveness of ASA on functional outcome and delayed
cerebral ischemia has to be studied in a larger trial.
PMID- 10690980
TI - Benign prognosis of never-symptomatic carotid occlusion.
AB - OBJECTIVE: To determine the prognosis of asymptomatic carotid artery occlusion.
BACKGROUND: As opposed to symptomatic carotid occlusion, little information is
available on the prognosis of asymptomatic carotid occlusion. METHOD: Thirty
never-symptomatic and 81 symptomatic patients with carotid occlusion underwent
baseline assessment of 15 risk factors together with PET measurements of oxygen
extraction fraction (OEF). Every 6-month telephone contact recorded interval
medical treatment and subsequent stroke occurrence during an average follow-up of
32 months. Patients, treating physicians, and an end point adjudicator were
blinded to PET results. RESULTS: Ischemic stroke occurred in 1 of 30 of never
symptomatic patients (3.3%) and 15 of 81 of symptomatic patients (18.5%; p =
0.03). No strokes in the carotid territory distal to the occluded vessel occurred
in the never-symptomatic patients. Multivariate analysis of baseline risk factors
for all 111 patients revealed that age, plasma fibrinogen level, and PET findings
of high OEF distal to the occluded carotid artery were the only independent
predictors of subsequent stroke (p < 0.05). Previous ipsilateral hemispheric or
retinal symptoms was not a significant predictive variable. The lower risk of
stroke in never-symptomatic patients was associated with a lower incidence of
high OEF (4 of 30) as opposed to symptomatic patients (39 of 81; p = 0.002), but
there was no significant difference in age or fibrinogen level. CONCLUSIONS:
Never-symptomatic carotid occlusion carries a very low risk of subsequent
ischemic stroke. This benign prognosis is associated with a low incidence of
cerebral hemodynamic compromise in these patients. These data support further the
importance of hemodynamic factors in the pathogenesis of ischemic stroke in
patients with carotid occlusion.
PMID- 10690981
TI - Early lacunar strokes complicating polyarteritis nodosa: thrombotic
microangiopathy.
AB - OBJECTIVE: To determine the patterns and mechanisms of polyarteritis nodosa (PAN)
associated strokes (PANAS). BACKGROUND: Strokes are reputed to be rare
complications of PAN and to occur at a late stage (2 to 3 years). The cause of
stroke is unknown but may be related either to atherosclerosis-like occlusive
vasculopathy, caused possibly by hypertension or corticosteroid (CS) use, or to
vasculitic arterial occlusion. METHODS: Clinical and radiologic patterns,
latencies, and current therapy at onset in 15 PANAS patients (4 of the authors'
and 11 published cases) were analyzed. RESULTS: A lacunar stroke syndrome (11/15
cases, 73%) was the most frequent stroke pattern in PANAS (multiple, small, deep
infarcts in 6, [55%], pontine lacunae in 3 [27%], and leukoaraiosis in 2 [18%]),
followed by pure lobar hematoma and bilateral, possibly cardioembolic, large
ischemic infarcts (2 cases each). A stroke latency shorter than that previously
established (within 8 months in 73% of cases; mean latency, 6.5 months) and a
close relationship between the use of CS and stroke in PAN also were found. Of
the 77% of first-time or recurrent lacunar strokes that developed despite CS
therapy, 80% appeared within 6 months and 50% within 3 weeks of CS initiation.
CONCLUSION: Early lacunar stroke syndrome, related to deep small- or pontine
penetrating artery thrombotic microangiopathy rather than vasculitis, was the
most frequent PANAS pattern. This vasculopathy may be aggravated by
corticosteroid (CS) therapy enhancement of either platelet thromboxane A2
production or arterial wall fibrosis. Thus, antiplatelet drugs in association
with CS may be advisable for preventing stroke occurrence or recurrence in PAN.
PMID- 10690982
TI - Somatosensory potentials, CSF creatine kinase BB activity, and awakening after
cardiac arrest.
AB - OBJECTIVE: To examine the utility of somatosensory evoked potential (SEP) peaks
and CSF creatine kinase BB isoenzyme activity (CKBB) in predicting nonawakening
from coma due to cardiac arrest. BACKGROUND: Accurate predictors of neurologic
outcome in patients comatose after cardiac arrest are needed to improve medical
decision making. METHODS: A total of 72 comatose patients had bilateral median
SEPs, and of these, 52 had CSF and CKBB. Awakening was defined as following
commands or having comprehensible speech. Both short (N1) and long (N3) latency
SEP peaks were analyzed. Nonparametric analyses were used. RESULTS: For patients
who had both tests, CKBB > or = 205 U/L predicted nonawakening with a sensitivity
of 49% and a specificity of 100%. Bilateral absence of the N1 peak predicted
nonawakening with a sensitivity of 53% and a specificity of 100%. Using CKBB > or
= 205 U/L, bilaterally absent SEP N1 peaks, or both predicted nonawakening with a
sensitivity of 69% and a specificity of 100%. Using CKBB > or = 205 U/L,
bilaterally absent N1 peaks, bilateral N3 > or = 176 msec or absent, or some
combination predicted nonawakening with a sensitivity of 78% and a specificity of
100%. CONCLUSION: The combination of an absent N1 peak and elevated CKBB performs
better than either alone in predicting nonawakening after cardiac arrest.
Prolonged or absent N3 latency may increase sensitivity. These results should be
interpreted with caution given the small number of patients and the possibility
of a self-fulfilling prophecy.
PMID- 10690983
TI - Neuropsychological effects of valproate in traumatic brain injury: a randomized
trial.
AB - OBJECTIVES: To examine the neuropsychological side effects of valproate (VPA)
given to prevent posttraumatic seizures. METHODS: In a randomized, double-masked,
parallel group clinical trial, we compared the seizure prevention and
neuropsychological effects of 1 or 6 months of VPA to 1 week of phenytoin. We
studied 279 adult subjects who were randomized within 24 hours of injury and
examined with a battery of neuropsychological measures at 1, 6, and 12 months
after injury. We examined drug effects cross-sectionally at 1, 6, and 12 months
and longitudinally by examining differential change from 1 to 6 months and from 6
to 12 months as a function of protocol-dictated changes in treatment. RESULTS: No
significant adverse or beneficial neuropsychological effects of VPA were
detected. CONCLUSIONS: Valproate (VPA) appears to have a benign
neuropsychological side effects profile, making it a cognitively safe
antiepileptic drug to use for controlling established seizures or stabilizing
mood. However, based on this study, VPA should not be used for prophylaxis of
posttraumatic seizures because it does not prevent posttraumatic seizures, there
was a trend toward more deaths in the VPA groups, and it did not have positive
effects on cognition.
PMID- 10690984
TI - Is geomagnetic activity a risk factor for sudden unexplained death in epilepsies?
AB - OBJECTIVE: To test the hypothesis that sudden unexplained death (SUD) in epilepsy
is related to geomagnetic activity. BACKGROUND: Prior studies presume that
geomagnetic activity (with average amplitudes above 50 nanotesla [nT]) is
associated with SUD in epileptic human patients and in epileptic laboratory rats.
METHODS: In a retrospective study, 46 epileptic patients with definite SUD were
compared with 108 epileptic patients with known cause of death (KCD) who died
between 1981 and 1992. A complete postmortem examination was performed in all
cases. The time of the day and date of death, as well as two international
geomagnetic indices concerning Bartels' planetary 3-hour signs (Kp) and the mean
planetary daily amplitudes (Ap) at time of death, were assessed. RESULTS: Among
45 SUD individuals, the local time (37.8%) and the universal time of death
(35.6%) peaked within the critical period between 3 to 9 AM. However, the SUD and
KCD group did not substantially differ in regard to the distribution of local or
universal time of death (p > 0.2, Fisher test). Neither the Kp signs at death and
2 hours before death nor the Ap values showed considerable differences between
the SUD and KCD series (p > 0.2, Mann-Whitney test). Merely 4.3% of SUD patients
and 3.7% of KCD patients were associated with Ap indices above 50 nT (p > 0.2,
Fisher test). CONCLUSION: The results do not support the hypothesis that
geomagnetic activity is related to occurrence of sudden unexplained death in
epileptic patients.
PMID- 10690985
TI - Bilateral frontal polymicrogyria: a newly recognized brain malformation syndrome.
AB - BACKGROUND AND OBJECTIVE: Polymicrogyria is a brain malformation characterized by
abnormal cortical lamination, excessive cortical folding, and fusion of the
cortical molecular layer. Two distinct bilateral localized forms have been
described: bilateral perisylvian polymicrogyria, which has proved to be
genetically heterogeneous, and bilateral parasagittal parieto-occipital
polymicrogyria, which has been described only in sporadic patients. We describe
13 patients with symmetric polymicrogyria of both frontal lobes back to the
precentral sulcus: bilateral frontal polymicrogyria (BFP). METHODS: Review of
clinical records, brain MRI, and EEG results of 13 patients; correlation with
other regional polymicrogyrias. RESULTS: The abnormal cortex extended from the
frontal poles anteriorly to the precentral gyrus posteriorly and to the frontal
operculum inferiorly and was relatively symmetric in all 13 patients. All
patients presented with developmental delay and mild spastic quadriparesis, but
variably impaired language development (12/13), mental retardation (11/13), and
epilepsy (5/13) also occurred. BFP was sporadic in 13 of 13 patients, but 2 of 13
had consanguineous parents. CONCLUSIONS: BFP extends the spectrum of the
recognized bilateral symmetric regional polymicrogyria syndromes.
PMID- 10690986
TI - Brain volume in children with neurofibromatosis type 1: relation to
neuropsychological status.
AB - OBJECTIVE: To determine characteristics of brain morphology in children and
adolescents with neurofibromatosis type 1 and relate these characteristics to
neuropsychological functioning. BACKGROUND: Neurofibromatosis type 1 is
associated with numerous CNS abnormalities and cognitive impairment. Abnormal
high signal intensity visible on brain MRI, brain tumors, and macrocephaly are
common. Research into links between neuroanatomic and cognitive features has been
inconclusive. METHODS: Fifty-two children and adolescents with neurofibromatosis
type 1 were compared with 19 control subjects on several quantitative
neuroanatomic and neuropsychological measures. RESULTS: Total brain volume,
especially gray matter, was significantly greater for neurofibromatosis type 1
subjects than the control subjects. Group differences in the ratio of gray matter
to white matter were more prominent in younger than in older subjects. Volume of
gray matter in the subjects with neurofibromatosis type 1 was related to their
degree of learning disability. Corpus callosum size was significantly larger for
subjects in the neurofibromatosis type 1 group, and diminished performance on
measures of academic achievement and visual-spatial and motor skills were
associated with greater regional corpus callosum size. CONCLUSIONS: Neuroanatomic
morphology and the developmental pattern of gray matter and white matter in
subjects with neurofibromatosis type 1 differed from in control subjects. Some of
these differences are related to the neuropsychological status of the
neurofibromatosis type 1 group. We propose that delayed developmental apoptosis
results in macrocephaly and a delay in the development of appropriate neuronal
connections in children with neurofibromatosis type 1. We further propose that
these morphologic delays are related to the cognitive profile of
neurofibromatosis type 1.
PMID- 10690987
TI - Cerebrovascular changes in the basal ganglia with HIV dementia.
AB - BACKGROUND: HIV dementia is a form of subcortical dementia. Clinical, radiologic,
pathologic, and biochemical studies suggest a major contribution of basal ganglia
dysfunction to the pathogenesis of this disorder. Many investigators have
proposed a contribution of a disrupted blood-brain barrier (BBB) to the
pathogenesis of HIV dementia. OBJECTIVE: To identify microvascular abnormalities
in vivo in basal ganglia or white matter of persons with HIV dementia. METHODS:
Time course of MRI postcontrast enhancement was determined in basal ganglia and
white matter of HIV-infected persons without dementia (Memorial Sloan Kettering
[MSK] score of 0; n = 4); HIV-infected persons with mild dementia (MSK score of
0.5; n = 2); and HIV-infected persons with moderate-to-severe dementia (MSK > or
= 1.0; n = 6). RESULTS: Increased basal ganglia enhancement was observed in
individuals with moderate-to-severe dementia relative to nondemented individuals,
both immediately and 30 minutes after contrast administration. Decline of basal
ganglia enhancement was slower in the moderately to severely demented patients
and, when normalized to intravascular enhancement of sagittal sinus, suggested
leakage of contrast agent, consistent with increased permeability of BBB. A
significant correlation between the postcontrast fractional enhancement at 30
minutes (FE30) and the MSK score was noted. White matter showed no significant
differences in postcontrast enhancement among the three groups. CONCLUSION:
Increased early enhancement in basal ganglia of the HIV dementia group is
consistent with increased regional cerebral blood volume (rCBV). Increased late
enhancement is strongly suggestive of BBB disruption. Similar abnormalities were
absent in the white matter adjacent to the caudate nucleus.
PMID- 10690988
TI - Cerebrospinal fluid HIV RNA originates from both local CNS and systemic sources.
AB - OBJECTIVE: To identify the sources of HIV virions in CSF by modeling treatment
associated HIV dynamics. BACKGROUND: We postulated a model in which cell-free CSF
virions originate from two major sources, namely, systemic non-CNS and CNS
tissues, the latter including brain parenchyma and meninges. The model predicted
that with initiation of antiretroviral therapy, the acute-phase decline in CSF
HIV RNA levels would be controlled by the kinetics of the dominant virion source
(systemic versus CNS). Based on prior observations, we hypothesized that the
dominant source of CSF virions would shift from systemic to CNS in more advanced
disease. METHODS: Three patient groups were studied: Group 1 (n = 5):
nondemented, with early HIV disease (CD4+ lymphocytes > or = 400/microL) or
pleocytosis (CSF leukocytes > or = 4/microL); Group 2 (n = 5): nondemented, with
advanced HIV disease (CD4+ < 400/microL) and no pleocytosis; Group 3 (n = 2):
patients with HIV-associated dementia (HAD). All patients began a new, highly
active antiretroviral treatment regimen and underwent serial lumbar punctures and
phlebotomies. RESULTS: For patients in Group 2, the rate of decline in CSF HIV
RNA was slower than in plasma (p < 0.00001). For Group 1, the rate of decline in
CSF was not different from plasma (p > 0.25). Patients with HAD showed high CSF
HIV RNA after 5 to 6 weeks of treatment despite a 100-fold decrease in plasma HIV
RNA. CONCLUSIONS: CSF and plasma HIV dynamics became increasingly independent in
advanced HIV disease, and the compartmental discrepancy was largest in HAD. Our
findings suggest that viral replication in CNS tissues may constitute a major,
independent source of CSF HIV RNA. In patients with HAD, brain parenchyma itself
may be the principal CNS tissue source, and CNS-targeted treatment strategies may
be required to eradicate this infection.
PMID- 10690989
TI - Functional consequences of chloride channel gene (CLCN1) mutations causing
myotonia congenita.
AB - OBJECTIVE: To determine the functional consequences of missense mutations within
the skeletal muscle chloride channel gene CLCN1 that cause myotonia congenita.
BACKGROUND: Myotonia congenita is a genetic muscle disease associated with
abnormalities in the skeletal muscle voltage-gated chloride (ClC-1) channel. In
order to understand the molecular basis of this inherited disease, it is
important to determine the physiologic consequences of mutations found in
patients affected by it. METHODS: The authors used a mammalian cell (human
embryonic kidney 293) expression system and the whole-cell voltage-clamp
technique to functionally express and physiologically characterize five CLCN1
mutations. RESULTS: The I329T mutation shifted the voltage dependence of open
probability of ClC-1 channels to the right by 192 mV, and the R338Q mutation
shifted it to the right by 38 mV. In addition, the I329T ClC-1 channels
deactivated to a lesser extent than normal at negative potentials. The V165G,
F167L, and F413C ClC-1 channels also shifted the voltage dependence of open
probability, but only by +14 to +20 mV. CONCLUSIONS: The functional consequences
of these mutations form the physiologic argument that these are disease-causing
mutations and could lead to myotonia congenita by impairing the ability of the
skeletal muscle voltage-gated chloride channels to maintain normal muscle
excitability. Understanding of genetic and physiologic defects may ultimately
lead to better diagnosis and treatment of patients with myotonia congenita.
PMID- 10690990
TI - Psychometric evaluation of a new sensory scale in immune-mediated
polyneuropathies. Inflammatory Neuropathy Cause and Treatment (INCAT) Group.
AB - OBJECTIVE: To perform a psychometric evaluation of the inflammatory neuropathy
cause and treatment (INCAT) sensory sumscore (ISS) in sensory-motor immune
mediated polyneuropathies. This new sensory scale was evaluated to strive for
uniformity in assessing sensory deficit in these disorders. METHODS: The ISS
comprises vibration and pinprick sense plus a two-point discrimination value and
ranges from 0 (normal sensation) to 20 (maximum sensory deficit). Before its
clinical use, a panel of expert neurologists concluded that the ISS has face and
content validity. The construct validity of the ISS was investigated by
correlation and regression studies with additional scales (Nine-Hole Peg Test, 10
Meter Walking Test, a disability sumscore). All scales were applied in 113
patients with a stable neurologic condition (83 patients who experienced Guillain
Barre syndrome [GBS] in the past, 22 with chronic inflammatory demyelinating
polyneuropathy [CIDP], 8 patients with a monoclonal gammopathy associated
polyneuropathy), and 10 patients with recently diagnosed GBS or CIDP with
changing clinical conditions. Reliability of the ISS was evaluated in the stable
patients. Its responsiveness was investigated in the patients examined
longitudinally. RESULTS: A moderate to good validity was obtained for the ISS
(stable group: r = 0.38 to 0.56, p < or = 0.006; longitudinal group: R = 0.60 to
0.82, p < or = 0.007, except for the association with the 10-Meter Walking Test
[p = 0.08]). Acceptable internal consistency, and inter- and intraobserver
reliability were demonstrated for the ISS (alpha = 0.68 to 0.87; R = 0.85 to
0.89, p < 0.0001). Standardized response mean scores for the ISS were high (> or
=0.8), indicating good responsiveness. CONCLUSIONS: All psychometric requirements
are provided for the the inflammatory neuropathy cause and treatment sensory
sumscore. The use of this scale is therefore suggested for bedside evaluation of
sensory deficit in the individual patient with a sensory-motor immune-mediated
polyneuropathy as well as in clinical trials.
PMID- 10690991
TI - Molecular and clinical analyses of spinocerebellar ataxia type 8 in Japan.
AB - OBJECTIVE: To clarify the molecular and clinical features of the newly identified
spinocerebellar ataxia type 8 (SCA8). METHODS: We analyzed the CTG repeat region
of the SCA8 gene in a series of Japanese patients with cerebellar ataxia. We also
investigated the frequency of the CTG repeat length in Japanese normal elderly
subjects older than age 79. Morphometric measurements on the cerebral MRI were
compared between patients with SCA8 and SCA6. RESULTS: The number of the combined
CTA/CTG repeats of six affected SCA8 alleles was 106.3+/-24.4 (mean +/- SD)
ranging from 89 to 155 and that of normal elderly subjects was 24.3+/-4.4 (n =
104 alleles) ranging from 15 to 34. The mean age at onset of the SCA8 cases was
53.8+/-19.7 years, with a range from 20 to 73 years. One father and daughter from
an SCA8 family showed remarkable paternal anticipation. The number increase from
father to daughter was + 16 CTG repeats, with a 31-year acceleration of onset.
The six identified SCA8 patients were clinically characterized by high
frequencies of incoordination of trunk and limbs, ataxic dysarthria, impaired
smooth pursuit, and horizontal nystagmus, and the MRI showed significant atrophy
of the cerebellar vermis and hemispheres compared with that of normal controls.
There was no significant difference between SCA8 and SCA6 on the morphometric MRI
study. CONCLUSIONS: The CTG repeat expansions in the SCA8 alleles were much
greater than the range of repeats in normal elderly subjects. The SCA8 phenotype
manifested by cerebellar symptoms and atrophy corresponded to features of the
autosomal dominant cerebellar ataxia type III (ADCA III).
PMID- 10690992
TI - Lasting cortical activation after repetitive TMS of the motor cortex: a glucose
metabolic study.
AB - OBJECTIVE: Cerebral [18F]fluorodeoxy-D-glucose PET ([18F]FDG-PET) was used to
visualize the lasting neuronal activation after repetitive transcranial magnetic
stimulation (rTMS) over the left hand area of the primary motor cortex (M1HAND).
BACKGROUND: Applied over M1HAND, rTMS has been shown to produce a modulation of
corticomotor excitability beyond the time of stimulation itself. METHODS: Eight
right-handed subjects underwent nonquantitative [18F]FDG-PET measurements during
two experimental conditions: at rest and after focal subthreshold 5-Hz rTMS over
the left M1HAND. In the post-rTMS condition, [18F]FDG was injected immediately
after the administration of 1,800 magnetic pulses over the left M1HAND. Relative
differences in normalized regional cerebral metabolic rate of glucose (normalized
rCMRglc) between conditions were determined using a voxel-by-voxel Student's t
test and volume-of-interest (VOI) analysis. Analysis was a priori restricted to
the M1HAND, the supplementary motor area (SMA), and the primary auditory cortex
of both hemispheres. RESULTS: A 5-Hz rTMS of the left M1HAND caused a lasting
relative increase in normalized rCMRglc within the M1HAND bilaterally and the
SMA. The magnitude and the topographic pattern of persisting relative rCMRglc
increases within these motor cortical areas demonstrated considerable
interindividual variations. CONCLUSIONS: Subthreshold 5-Hz repetitive
transcranial magnetic stimulation (rTMS) over the hand area of the primary motor
cortex is associated with a persisting neuronal activation in a distinct set of
motor cortical areas beyond the time of stimulation. The current findings
demonstrate that [18F]FDG-PET can localize and quantify regional net changes in
synaptic cortical activity after rTMS and thus might elucidate the mechanisms
underlying rTMS-associated therapeutic effects.
PMID- 10690994
TI - Psychogenic status epilepticus in children: psychiatric and other risk factors.
AB - The authors studied six children with repetitive psychogenic seizures severe
enough to mimic status epilepticus. All received IV antiepileptic drugs in an
emergency setting. Most had a family history of epilepsy. Affective and anxiety
disorders predominated as comorbid psychiatric diagnoses. Acutely stressful
situations precipitated all episodes of nonepileptic status epilepticus. With
aggressive psychotherapeutic intervention and pharmacologic treatment of their
underlying psychiatric diagnosis, the patients improved.
PMID- 10690993
TI - Involvement of the ventrolateral medulla in parkinsonism with autonomic failure.
AB - OBJECTIVE: To determine whether patients with PD and autonomic failure (AF),
manifested primarily with orthostatic hypotension (OH), have a consistent loss of
tyrosine hydroxylase (TH) neurons in the rostral ventrolateral medulla (RVLM),
similar to that occurring in patients with multiple system atrophy (MSA) and AF,
and to determine whether there is loss of nicotinamide, adenine dinucleotide
phosphate (NADPH) diaphorase (NADPH-d) RVLM neurons in both groups of patients.
METHODS: The numbers of TH and NADPH-d neurons in the RVLM was assessed in brain
sections obtained at autopsy from five patients with suspected PD and OH, six
patients with MSA, two patients with corticobasal ganglionic degeneration and no
AF, and 10 control subjects with no history of neurologic disease. Cell numbers
were compared among groups and correlated with their final neuropathologic
diagnosis. RESULTS: The number of TH neurons in the RVLM of patients with PD and
OH were not significantly different from control subjects, and there were marked
individual variations. The TH cell numbers in the RVLM were significantly higher
(p < 0.06) in patients with PD than in patients with MSA, despite a similar
degree of severity of OH. As a group, patients with PD and OH had reduced numbers
of NADPH-d cells in the RVLM compared with control subjects, but again there were
marked individual variations. NADPH-d cell numbers were reduced consistently and
more markedly in patients with MSA. CONCLUSION: Unlike the case in patients with
MSA, the number of TH neurons in the RVLM is highly variable in patients with PD
and is unlikely to contribute significantly to the pathophysiology of OH. As a
group, patients with PD have reduced numbers of NADPH-d neurons in the RVLM, but
some patients had cell counts similar to control subjects. On the other hand,
NADPH-d cell depletion in the RVLM is a consistent finding in MSA and may
contribute to cardiorespiratory dysfunction in this disorder.
PMID- 10690995
TI - "Pressure to laugh": an unusual epileptic symptom associated with small
hypothalamic hamartomas.
AB - Gelastic seizures are the hallmark of the epilepsy syndrome associated with
hypothalamic hamartomas. Patients typically develop cognitive deterioration and
refractory seizures. The authors describe three patients with small hypothalamic
hamartomas without these features and thus identify a mild end to the clinical
spectrum. All had the unusual symptom of "pressure to laugh," often without
actual laughter. This symptom could be dismissed as psychogenic but should be
recognized as a clue to the presence of this unusual lesion.
PMID- 10690996
TI - Stable weight during lamotrigine therapy: a review of 32 studies.
AB - A side effect associated with the use of some antiepileptic drugs (AEDs) is
change in body weight. To evaluate the effect of lamotrigine on body weight in
adult patients with epilepsy, we conducted a retrospective review of data from
463 patients treated with lamotrigine in 32 clinical trials. Mean daily dose was
259 (+/-155) mg and duration of therapy was 318 (+/-87) days. The mean change in
body weight was 0.5 (+/-5) kg. Lamotrigine was associated with stable body weight
in patients with epilepsy.
PMID- 10690997
TI - Bilateral focal motor status epilepticus with retained consciousness after
stroke.
AB - Bilateral motor seizures with retained consciousness are rare and often mistaken
for pseudoseizures. In the few reported cases, the seizures were brief and the
underlying lesion usually was a tumor. Here the authors describe a patient with
bilateral focal motor status epilepticus with retained consciousness after a
stroke. A seizure should be considered as the possible cause of continuous
bilateral limb movements with retained consciousness.
PMID- 10690998
TI - Amnesic confabulatory syndrome after focal basal forebrain damage.
AB - A 73-year-old woman developed amnesic confabulatory syndrome after a right focal
basal forebrain hemorrhage. The confabulation, despite persistent antegrade
amnesia, gradually subsided with improvement of the frontal executive function.
The lesion appeared to disrupt connections of the medial and lateral limbic
circuits important for memory. Simultaneous dysfunctioning of the two circuits
involving the medial temporal and frontal lobes may be necessary for the
development of this syndrome.
PMID- 10690999
TI - Relationship between motor and language activation using fMRI.
AB - The authors examined laterality ratios (i.e., [L-R]/[L+R]) from functional MRI
(fMRI) scans obtained in 12 healthy volunteers during unimanual left- and right
hand finger movements and during a verb generation language task. The language
and right-hand motor asymmetry ratios were correlated (rho = 0.71, p = 0.005) as
were the left- and right-hand ratios (rho = -0.68, p = 0.008). Subjects with
greater relative left hemisphere lateralization of language exhibit greater
relative unilateral hemisphere activation during right-hand movements.
PMID- 10691000
TI - Residual function in motor cortex contralateral to amputated hand.
AB - OBJECTIVE: To investigate residual function of the motor cortex corresponding to
the hand of the amputated arm (MCamp). METHODS: Focal transcranial magnetic
stimulation (TMS) of MCamp was performed in 10 patients 22 to 52 years after arm
amputation to inhibit tonic muscle contraction in the intact hand ipsilateral to
cortex stimulation. RESULTS: In all patients, onset latency, degree, and duration
of this inhibition were normal. CONCLUSION: The presence of motor inhibition in
the residual hand of amputees originating from the hand motor representation of
MCamp indicates residual cortical motor representation of the lost hand
irrespective of whether the effect is mediated by commissural or ipsilateral
corticospinal connections.
PMID- 10691001
TI - Cerebral CO2 reactivity, cholesterol, and high-density lipoprotein cholesterol in
the elderly.
AB - Cholesterol and its subfractions play a role in the development of
atherosclerosis. Cerebral CO2 reactivity reflects the compensatory capacity of
cerebral arterioles. The authors investigated the relationship between total
cholesterol, high-density lipoprotein (HDL), their ratio, and cerebral CO2
reactivity in 826 participants from the Rotterdam Study. Cerebral CO2 reactivity
increased significantly with increasing levels of HDL and decreased significantly
with an increasing total cholesterol/HDL ratio. This suggests that blood lipids
may also affect smaller cerebral blood vessels.
PMID- 10691002
TI - Language disturbances in corticobasal degeneration.
AB - To characterize the language deficits in corticobasal degeneration (CBD) and
their relation to neuroradiologic findings, the authors administered a
standardized battery of neurobehavioral tests and performed MRI studies on 15
patients with CBD. Eight patients (53%) had classifiable aphasias, including
anomic, Broca's and transcortical motor aphasias. The aphasias were associated
primarily with left frontal and parietal cortical damage and subcortical white
matter and corpus callosum abnormalities. Our findings demonstrate that language
disturbances in CBD are more frequent than previously considered.
PMID- 10691003
TI - Role of brain biopsy in the management of focal brain lesions in HIV-infected
patients. Gruppo Italiano Cooperativo AIDS & Tumori.
AB - In this multicenter, retrospective study of 160 brain biopsies in the assessment
of HIV-related focal brain lesions, diagnostic sensitivity was acceptable (87%),
but the procedure carried considerable morbidity (7.5%) and mortality (3.1%).
Moreover, it is not always possible to initiate the changes in therapy indicated
by the results, and overall survival remains poor, with a median of 2 months.
Criteria for brain biopsy for the diagnosis of focal brain lesions should be
redefined to include selected patients for whom a less invasive approach does not
yield a definitive diagnosis.
PMID- 10691004
TI - Longitudinal study of neurotoxicity with occupational exposure to aluminum dust.
AB - Two cross-sectional studies were conducted at a German aluminum (Al) powder plant
to evaluate possible nervous system effects from occupational Al exposure. The
investigation included biological monitoring, a neuropsychological test battery,
and event-related P300 potentials. Neurophysiologic findings in workers
chronically exposed to Al dust did not differ from non-Al-exposed controls from
the same plant. The authors suggest that chronic exposure to Al dust, at the
levels documented in this study, does not induce measurable cognitive decline.
PMID- 10691005
TI - Chronic ophthalmoplegia with anti-GQ1b antibody.
AB - Anti-GQ1b antibodies are typically found in patients with the Miller Fisher
syndrome, all of whom will have, by definition, acute ophthalmoplegia. The
authors describe three patients with chronic ophthalmoplegia in the presence of
persistently high titers of immunoglobulin G anti-GQ1b antibody detected in an
ELISA, one of whom improved with immunotherapy. Anti-GQ1b antibodies may be
associated with some cases of chronic ophthalmoplegia of unknown cause.
PMID- 10691006
TI - Potential role of LIF as a modifier gene in the pathogenesis of amyotrophic
lateral sclerosis.
AB - Leukemia inhibitory factor (lif) is a potent survival factor for motoneurons in
cell culture and in vivo. The authors screened 104 patients with ALS and 338
control subjects for mutations in the LIF gene. In four ALS patients, but in no
control subject, a G-to-A point mutation at position 3400 was identified, which
leads to an amino acid exchange of valine to methionine at position 64 of the
mature lif protein. This region of the lif protein (AB loop) interacts with the
lif receptor. The authors suggest that LIF could act as a modifier gene which, in
combination with other genetic predispositions, might lead to motoneuron disease.
PMID- 10691007
TI - mtDNA A3243G MELAS mutation is not associated with multigenerational female
migraine.
AB - The authors searched for mitochondrial DNA (mtDNA) A3243G mutation in peripheral
blood leukocytes from female migraine patients with pure matrilinear history of
migraine along two or three generations. The current study was designed to
exclude any male transmission of the disease. The mutation was absent in all
patients. We conclude that mtDNA A3243G mutation does not contribute to the
pathogenesis of pure matrilinear multigenerational migraine with or without aura.
PMID- 10691008
TI - A successful pregnancy in a heterozygote for OTC deficiency treated with sodium
phenylbutyrate.
PMID- 10691009
TI - Immunoglobulin therapy for idiopathic chronic sensory ataxic neuropathy.
PMID- 10691010
TI - Stroke treatment with tissue plasminogen activator in the setting of aortic
dissection.
PMID- 10691011
TI - Delayed myelopathic presentation of the acquired hepatocerebral degeneration
syndrome.
PMID- 10691012
TI - Cerebellar degeneration associated with HIV infection.
PMID- 10691013
TI - Acute deterioration from thrombosis and rerupture of a giant intracranial
aneurysm.
PMID- 10691014
TI - Charcot-Marie-Tooth disease type 2 with restless legs syndrome.
PMID- 10691015
TI - Dementia is a major predictor of death among the Italian elderly.
PMID- 10691016
TI - Contrast agent neurotoxicity presenting as subarachnoid hemorrhage.
PMID- 10691017
TI - Detecting drug effects on short-term memory function using a combined delayed
matching and non-matching to position task.
AB - Operant delayed non-matching-to-position (DNMTP) and delayed matching-to-position
(DMTP) have become standard techniques to investigate drug effects on short-term
memory function in rats. However, these two tasks are normally conducted in
isolation. Using two standard drugs, the 5HT1A agonist 8-hydroxy-2-(di-n
propylamino)tetralin (8-OH-DPAT), and the muscarinic antagonist scopolamine, this
study looked at a two-choice operant task that essentially involved a mixed
DNMTP/DMTP paradigm. Thus, DNMTP trials were interspersed with DMTP trials in a
random sequence for the duration of a session. 8-OH-DPAT (0.03 mg/kg) slightly
but significantly improved response accuracy in a delay-dependent fashion during
DMTP but not DNMTP trials. The highest dose of 8-OH-DPAT (0.1 mg/kg) impaired
accuracy during DNMTP trials independent of delay and had no significant effect
during DMTP trials. Scopolamine (0.1 mg/kg) produced delay-dependent deficits in
accuracy during DMTP trials but delay-independent impairments during DNMTP
trials. Because both 8-OH-DPAT and scopolamine produced delay-dependent effects
with DMTP trials types and either had no effect (8-OH-DPAT) or produced delay
independent impairments (scopolamine) during DNMTP trials types, it is suggested
that DMTP trials had a greater dependence on short-term working memory function
than DNMTP trials that probably relied more on positional (mediating) strategies
for solving the task. Therefore, we believe that this mixed DNMTP/DMTP task
offers greater potential for more reliable and discerning interpretation of data
regarding short-term memory function in rodents than either of the paradigms
performed in isolation.
PMID- 10691018
TI - Analysis of dextrorphan, a metabolite of dextromethorphan, using gas
chromatography with electron-capture detection.
AB - Dextromethorphan, a constituent of many over-the-counter cough syrups, is used as
a probe drug for phenotyping subjects for their cytochrome P450 2D6 (CYP2D6)
enzyme activity and for measuring CYP2D6 activity of preparations such as
microsomes. In such studies, formation of the metabolite dextrorphan is used as
indicator of the activity of this CYP enzyme. The present report describes an
electron-capture gas chromatographic procedure developed for detection and
quantification of dextrorphan in human liver microsomal preparations in vitro.
After basification of the incubation mixture, dextrorphan was derivatized with
pentafluorobenzoyl chloride under aqueous conditions prior to analysis on a gas
chromatograph equipped with a capillary column, an electron capture detector, and
a printer-integrator. Para-hydroxymephenytoin was carried through the procedure
as internal standard. The procedure, which involves the derivatization of
dextrorphan under aqueous conditions, is rapid and involves the use of the
relatively economical procedure of electron-capture gas chromatography. The
derivative is stable and possesses excellent chromatographic properties.
PMID- 10691019
TI - Evaluation of erectile response by continuous measurement of penile diameter in
rats.
AB - The present study was performed to determine whether measurement of penile
diameter in an in vivo rat model is useful for pharmacologic and physiologic
investigations on penile erection. Penile erection induced by electrical
stimulation of the cavernous nerve was monitored by measuring the penile diameter
sonomicrometrically with a pair of 10-MHz piezoelectric crystals glued to the
opposite surfaces of the adventitia of the penile erectile chamber in
anesthetized rats. Using this method, we examined the effects of a nitric oxide
(NO) synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), and a
well-known phosphodiesterase 5 (PDE5) inhibitor, zaprinast, on the maximal
developed penile diameter (D-max) and the time from the maximum response to 50%
recovery (T50%) of the maximum response as an index of the duration of penile
erection. An intravenous injection of L-NAME at a dose of 10 mg/kg significantly
inhibited D-max produced by cavernous electrical stimulation at 5 to 50 V,
without affecting T50%. Sequential intravenous infusions of 10, 30, 100, and 300
microg/kg/min of zaprinast at 30-min intervals did not show any effect on D-max,
heart rate, and systolic arterial pressure, although doses of 100 and 300
microg/kg/min significantly prolonged T50% and the maximum dose decreased
diastolic arterial pressure. Moreover, zaprinast produced a more prominent
increase in cyclic guanosine monophosphate (cGMP) levels than cyclic adenosine
monophosphate levels in the plasma taken at the end of the maximum dose infusion.
Measurement of murine penile diameter with a sonomicrometrical device, indicating
that a NO-cGMP-PDE5 pathway plays a pivotal role in the penile diameter increase
and its maintenance, would be useful for pharmacologic and physiologic
investigations on penile erection.
PMID- 10691020
TI - Methodologic aspects of acetylcholine-evoked relaxation of rabbit aorta.
AB - The acetylcholine-evoked relaxation of rabbit isolated thoracic aorta
precontracted by phenylephrine was studied. Phenylephrine caused a steady
contraction that was maintained for 6 h. In the presence of calcium disodium
ethylenediaminetetraacetate (EDTA) and ascorbic acid the contraction decreased
with time. N(G)-Nitro-L-arginine abolished the inhibitory effect of EDTA and
ascorbic acid. Acetylcholine evoked a rapid concentration-dependent relaxation
that recovered spontaneously and slowly, but fully, with time. Relaxation evoked
by equieffective concentrations of carbachol and acetylcholine had the same time
course. Cumulative addition of acetylcholine (10(-7)-3 x 10(-5) M) caused a
marked relaxation that was reverted slightly at high concentrations. The
relaxation was the same with rings derived from the upper, middle, and lower part
of the thoracic aorta. Two consecutive concentration-response curves for
acetylcholine obtained at a 2-h interval demonstrated a slight development of
tachyphylaxis. The relaxation was inversely related to precontractile tension
evoked by phenylephrine when expressed as a percentage, but independent when
expressed as g tension. Storage of aorta in cold salt solution for 24 h did not
alter the relaxation. EDTA and ascorbic acid did not alter the relaxation. It is
concluded that (1) EDTA and ascorbic acid can not be used with impunity to
stabilize catecholamines used as preconstriction agents; (2) the reversal of the
acetylcholine-evoked relaxation is not due to hydrolysis of acetylcholine; (3)
the relaxation is uniform in all segments of thoracic aorta; (4) cold storage of
aorta does not alter the relaxation; and (5) acetylcholine releases the same
amount of relaxing factor, irrespective of the precontractile tension.
PMID- 10691021
TI - Wall stress-induced dysrhythmias in the isolated working rat heart perfused
through a cannula placed in the left ventricle via aorta.
AB - The purpose of the present study was to determine if our recently introduced
novel working rat heart preparation could be used to study wall stress-induced
dysrhythmias. A double cannula, which consisted of an outer cannula that, was
inserted in the aorta and an inner cannula that was advanced into the left
ventricle was used. The perfusion flowed through the inner cannula into the left
ventricle and was ejected from there into the aorta. Afterload was changed
suddenly from 60 to 160 Hg of pressure by turning a valve so that the fluid was
diverted to a column set at a different height. A sudden increase of aortic
pressure that lasted for 10 sec caused cardiac ectopic beats. Wall stress-induced
dysrhythmias were more sustained during perfusion with low potassium and low
magnesium Krebs-Henseleit solution. Bradykinin (1 microg) or epinephrine (10
microg) was injected as a bolus via an in-line injection port placed at the inner
cannula. Bradykinin significantly reduced the incidence of ectopic beats and
epinephrine increased the incidence of nonsustained runs of VT. This "working"
heart preparation is a convenient tool to study wall stress-induced dysrhythmias.
PMID- 10691022
TI - A new in vitro model for ethanol-induced gastric mucosal damage.
AB - A new in vitro model for ethanol-induced gastric damage is described. The stomach
was dissected from the rat, a polyethylene cannula introduced into the remnants
of the esophagus, and the pyloric end tied off. With the cardiac and pyloric
regions of the stomach secured by thread to a vertical glass rod or tube, the
whole was suspended in an organ bath containing aerated Krebs solution. Fifteen
minutes later, ethanol was introduced via the esophageal cannula. After an
additional 60 min, the stomach was removed from the Krebs solution, opened along
the mid line, and the lesions studied. Comparisons were made with a conventional
in vivo model. Results show that the lesion number, length, and total lesion area
obtained by the in vitro model were comparable to those obtained in the older in
vivo model. Histopathologically, lesions induced by both models were also
comparable. Clonazepam, a drug previously used in the in vivo model, was tested
in this model. Results indicate that clonazpam protected against ethanol-induced
gastric damage in vitro. The new model provides a method to study the action of
drugs on the stomach alone and to exclude in indirect actions of drugs via other
sites in the body.
PMID- 10691023
TI - The mechanism of thrombin-induced prostacyclin synthesis in human endothelial
cells with reference to the gene transcription of prostacyclin-related enzymes
and Ca2+ kinetics.
AB - This study was designed to evaluate the effect of thrombin on prostacyclin (PGI2)
production in cultured human vascular endothelial cells in association with
intracellular Ca2+ and with the gene expression of prostaglandin H2 synthase
(PGHS) and phospholipase A2 (PLA2) using competitive polymerase chain reaction.
Thrombin enhanced the PGI2 synthesis dependent with time. Additionally, thrombin
increased the intracellular Ca2+, which stimulates PLA2, resulting in arachidonic
acid cleavage from membrane phospholipids and its subsequent conversion into PGI2
through the PGHS pathway. The elevation of intracellular Ca2+ was a result of
Ca2+ influx and Ca2+ release from its intracellular storage sites. In this study,
PGHS-1 mRNA was constitutively expressed, whereas PGHS-2 mRNA was not. With the
stimulation of thrombin, cytosolic PLA2 (cPLA2) mRNA increased 9-fold at 15 min,
PGHS-1 mRNA increased 3.4-fold at 180 min, and PGHS-2 mRNA increased 38-fold at
60 min. These results suggest that the elevation of intracellular Ca2+ and the
expression of cPLA2, PGHS-1, and PGHS-2 mRNA cause PGI2 generation.
PMID- 10691024
TI - A time course study for the development of an immunocompromised wound model,
using hydrocortisone.
AB - Although wound healing is essentially a physiologic process, some chronic wounds
exhibit considerable delay in healing. Often these do not heal perfectly in
individuals with low immune profiles. Thus, the present study was undertaken to
develop an excision wound model in the immunocompromised state induced by
pretreatment with hydrocortisone (HC) 40 mg/kg intramuscularly in male rats.
Wounds of 8-mm diameter were made on the preshaved dorsal surface of rats using
an Acuderm biopsy punch, following pretreatment with HC. After 14 days HC-treated
animals exhibited atrophy of spleen and adrenal glands and a significant
reduction of circulating lymphocytes and increase in neutrophils; these changes
are indicative of immunosuppressive state of animals. The cell proliferation was
significantly affected as shown by decreases in DNA (23%) and protein (11%).
Furthermore, there were also significant reductions in tensile strength (37%) and
hydroxyproline (33%) contents. These results were further supported by lack of
contraction of wound edges. It is concluded that animals primed with HC 1 week
prior to wounding developed prolonged immunosuppression, which significantly
impaired the wound healing as compared with other groups. Thus, this can be
experimentally employed as an immunocompromised wound model for evaluating
compounds as novel wound healers suitable for immunocompromised subjects.
PMID- 10691025
TI - A new method for recording surface compound potentials in sympathetic ganglia
from mouse, rat, and guinea pig--application to muscarinic and nicotinic
depolarizations.
AB - We present a new method for electrophysiologic investigations in isolated
autonomous ganglia of a variety of laboratory animals. This method enables
determination of surface compound potentials in ganglia and changes induced by
pharmacologic compounds. Advantages of our methods are as following: (1) the
method is relatively simple and does not require sophisticated experimental
setups, with minor modifications it is adaptable to investigate ganglia of
varying sizes; (2) the signal amplitude is comparable or even higher when
compared with signals obtained by other methods: (3) the apparatus allows fast
addition and removal of the investigational compounds and thus the determination
of acute and subacute desensitizing effects; and (4) fast preparation and minor
tissue injuries during preparation of the ganglia allow determination of surface
potential changes over a time period of up to 2 days without qualitative changes
of the parameters. In this report we demonstrate the validity of this method
using superior cervical ganglia from rat, mouse, and guinea pig. Agonists used to
trigger potential changes are the cholinergic agonists acetylcholine, muscarine,
nicotine, and carbachol. The possibility of receptor desensitization by these
compounds is investigated by repeated application over 5 h.
PMID- 10691026
TI - Inhibition of the action of the topoisomerase II poison amsacrine by simple
aniline derivatives: evidence for drug-protein interactions.
AB - The action of the anticancer drug amsacrine appears to involve molecular
interactions with both DNA and topoisomerase II. It has been shown previously
that DNA intercalators can inhibit the action of amsacrine and several other
topoisomerase II poisons, presumably as a result of interference with the DNA
binding sites for the enzyme. We show here that drug molecules such as N
phenylmethanesulfonamide, which mimic the anilino side chain of amsacrine,
inhibit the cytotoxicity against cultured Lewis lung murine carcinoma of
amsacrine, amsacrine analogues including asulacrine and DACA (N-[2
(dimethylamino)-ethyl]acridine-4-carboxamide dihydrochloride), and etoposide. In
contrast, the cytotoxicity of doxorubicin was slightly increased by co-incubation
with N-phenylmethanesulfonamide. The cytotoxicity of amsacrine was also modulated
in human Jurkat leukemia, HCT-8 colon, and HT-29 colon cell lines. Because o
AMSA, an amsacrine analogue containing a methoxy group in the ortho rather than
in the meta position, is known to be inactive as an antitumor drug, the abilities
of the ortho and meta methoxy-substituted derivatives of methyl-N-phenylcarbamate
to reverse the cytotoxicity of amsacrine, asulacrine, and DACA were compared. The
ortho substitution decreased activity while meta substitution slightly increased
it, suggesting that the side chains were binding to a similar site to that
occupied by amsacrine. To determine whether the side chain variants actively
inhibited the formation of DNA-topoisomerase II covalent complexes, cultured
cells were treated with amsacrine or asulacrine, harvested, and lysed directly on
acrylamide gels before electrophoresis and Western blotting to identify non-DNA
bound topoisomerase II. Extractable topoisomerase II was depleted in cells
incubated with amsacrine but partially restored by coculture with methyl-N
phenylcarbamate. The findings are consistent with the hypothesis that low
molecular weight molecules can modulate the effects of topoisomerase II poisons
by directly interacting with the enzyme.
PMID- 10691028
TI - Influence of static magnetic field on the antiproliferative effects of vitamin D
on human breast cancer cells.
AB - We describe the effect of a 0.2 tesla (T) static magnetic field generated by a
magnetic resonance tomograph and of vitamin D treatment on a human breast cancer
cell line (MCF-7). Cell damage and proliferation were monitored by measuring the
incorporation of [3H]thymidine in duplicating DNA and by the clonogenic assay.
[3H]Thymidine incorporation in MCF-7 was stimulated by vitamin D at low doses
(10(-12)-10(-10) M), whereas it was inhibited at higher concentrations (10(-9)
10(-6) M). Magnetic field treatment (0.2 T) decreased [3H]thymidine incorporation
in human breast cancer cells, eliminating the proproliferative effect of low
doses of vitamin D, and enhanced the vitamin D antiproliferative effect, further
reducing [3H]thymidine incorporation, from -12.5% (P < 0.05) to -66.7% (P <
0.001), over the range of 10(-9) to 10(-6) M. In the clonogenic assay, ability of
MCF-7 to form colonies was inhibited by vitamin D 10(-9) M and above, whereas 3-h
exposure to 0.2 T magnetic field had no effect on the number of cell colonies
formed. In conclusion, vitamin D treatment yields a permanent antiproliferative
effect, while magnetic field exposure only temporarily slows down cellular
growth. These findings suggest that therapy with vitamin D may prove beneficial
for chemoprevention or treatment of breast cancer. Static magnetic field, alone
or in combination, does not appear to represent an effective candidate for breast
cancer therapy, at least at the intensity used in the present study.
PMID- 10691027
TI - The protective effect of estrogen against chemically induced murine colon
carcinogenesis is associated with decreased CpG island methylation and increased
mRNA and protein expression of the colonic vitamin D receptor.
AB - Epidemiological studies suggest that estrogen prevents neoplastic transformation
in the intestinal mucosa. Estrogen was shown to increase the expression of
vitamin D receptors (VDR) in a variety of tissues. 1,25-Dihydroxyvitamin D [1,25
(OH)2D] and several of its analogues are known as potent antineoplastic and
prodifferentiative in many cell types, including colon-derived cells. The present
study was designed to examine the effect of estradiol (E2) on dimethylhydrazine
(DMH)-induced colon cancer in rats, and the possibility that E2 may exert its
protective effect on the colon through modulation of the vitamin D-endocrine
system. The in vivo effect of E2 on DMH-induced colorectal cancer was studied in
four groups of ovariectomized female rats: (I) untreated control, (II) E2
treated, (III) DMH treated, and (IV) combined E2 and DMH treated. Significantly
higher uterine weights and higher colonic estrogen receptor content confirmed the
effectiveness of ovariectomy and E2 replacement. The number of malignant tumors
in group IV was 2.3+/-1.1 (mean +/- SE) per rat, compared with 8.1+/-1.9 in group
III (P < 0.001). Exposure to estrogen was associated with a marked increase in
VDR mRNA content and VDR protein expression in the normal colonic mucosa. In
tumor extracts VDR protein expression was considerably lower compared with normal
mucosa. Estrogen treatment did not affect serum levels of 25(OH)D, 1,25(OH)2D,
and PTH. Significant CpG island methylation in the VDR gene was observed in
colonic tissue DNA harvested from rats treated with DMH, but not in colonic
mucosae from rats treated with DMH + E2. The highest frequency of CpG methylation
in the VDR gene was detected in DNA extracted from cancer tissue rims. In
summary, the protective effect of estrogen against chemically induced colonic
carcinogenesis is associated with reduced methylation of the VDR gene and with
upregulation of both VDR gene transcription and protein expression. We suggest
that estrogen may interfere with the process of CpG DNA methylation in the
colonic mucosa to prevent silencing of the VDR gene. Increased VDR activity could
be one of the mechanisms by which estrogen protects against neoplastic
transformation in the colon.
PMID- 10691029
TI - Growth inhibition of a human ovarian tumor by a novel paclitaxel derivative in
SCID mice.
AB - We report here the toxicity and therapeutic effects of 2'-alpha-bromohexadecanoyl
paclitaxel (BrC16HT), a prodrug form of paclitaxel, in mice. Paclitaxel is the
active ingredient of Taxol. The maximum tolerated dose, at a one dose per day for
5-day schedule, was 37.5 mg/kg for BrC16HT compared to 12.5 for Taxol
administered IP, and was 12.5-25 mg/kg for either agent administered IV. Dose
dependent therapeutic effects were found for BrC16HT against a human ovarian
tumor (OVCAR-3) grown in SCID mice. IP treatments with BrC16HT against early or
established IP-implanted OVCAR-3 tumor increased mean survival times more than
treatment with Taxol. Long-term survivors were found only in groups treated with
BrC16HT. Intravenously administered BrC16HT was more effective than Taxol against
SC OVCAR-3 tumor. Early treatment (25 mg/kg x 5) completely inhibited tumor
growth through 120 days after tumor implantation. Pharmacokinetic studies suggest
that BrC16HT is slowly hydrolyzed to paclitaxel and circulates longer than
paclitaxel from Taxol. Thus, BrC16HT may provide sustained levels of paclitaxel,
which may contribute to the increased efficacy of BrC16HT compared to Taxol.
PMID- 10691030
TI - Identification of seven genes regulated by wild-type p53 in a colon cancer cell
line carrying a well-controlled wild-type p53 expression system.
AB - We applied a differential display method to screen mRNAs isolated from a newly
established cell line that carried a wild-type p53 transgene under control of the
lactose operon. To investigate the p53 signaling pathway, we looked for genes
whose expression was significantly induced or suppressed by induction of wild
type p53 protein, and identified seven. DNA sequence analyses revealed that the
two genes that were upregulated encoded isozyme 6 of aldehyde dehydrogenase
(ALDH6) and subunit I of cytochrome c oxidase (COI). The five genes that were
downregulated encoded protein-tyrosine kinase (Syk), high mobility group
chromosomal protein 17 (HMG-17), transferrin receptor, human alpha-tubulin, and
sds22-like protein. The results indicated that genes related to cell cycle
regulation, cell respiration, and cytoskeletal structure are involved in the
process of growth arrest induced by wild-type p53.
PMID- 10691031
TI - Neuroprotective interactions in rats between paclitaxel and cisplatin.
AB - Paclitaxel and cisplatin are associated with dose-limiting neurotoxicity that may
result from their differing effects on microtubule stability in peripheral
nerves. We hypothesized that such different actions of paclitaxel and cisplatin
could be exploited to minimize their neurotoxicity by giving them in combination.
Paclitaxel (9-18 micromol/kg/week or 7.7-15.4 mg/kg/week) and cisplatin (5-10
micromol/kg/week or 1.5-3 mg/kg/week) were given alone and in combination to
female Wistar rats. Treatment was given once per week for a total of 7-10 weeks.
Paclitaxel and cisplatin were given 24 h apart when they were given in
combination. Changes in sensory nerve conduction velocity (SNCV) and dorsal root
ganglia (DRG) morphology were measured. The nature of their interaction was
analyzed using an isobologram. Their antitumor activity alone or in combination
was also determined in C57B1/6 mice bearing colon 38 tumors. Reductions in SNCV
occurred with paclitaxel alone (P = 0.009), cisplatin alone (P = 0.012), and
cisplatin given 24 h before paclitaxel (P < 0.0001). In contrast, there was no
significant change in SNCV with paclitaxel given 24 h before cisplatin (P =
0.11). An isobologram showed that the SNCV effects of the drug combinations were
less than additive or antagonistic. Cisplatin-induced morphometric changes in DRG
neurons were less marked when cisplatin was given with paclitaxel (P = 0.004).
Concentrations of platinum in dorsal root ganglia, sural nerves, and sciatic
nerves were not altered by giving paclitaxel before cisplatin. Tumor growth
delays (TGD) were greater after treatment with paclitaxel (23.4 micromol/kg or 20
mg/kg) given 24 h before cisplatin (23.3 micromol/kg or 7 mg/kg) (TGD = 7.5 days)
than after paclitaxel (23.4 micromol/kg or 20 mg/kg) (TGD = 2.0 days) or
cisplatin (23.3 micromol/kg or 7 mg/kg) (TGD = 3.5 days) alone. Paclitaxel and
cisplatin antagonized each other's neurotoxicity in Wistar rats. Combining
cytotoxic agents with opposing effects on peripheral nerves has potential for
minimizing neurotoxicity in patients.
PMID- 10691032
TI - Supplementation with soybean lipids reduces goat serum-induced apoptosis in the B
cell hybridoma CC9C10.
PMID- 10691033
TI - In situ labeling of adherent cells with PKH26.
PMID- 10691034
TI - Primary cultures of midgut cells from Heliothis virescens can be frozen and
stored.
PMID- 10691035
TI - Activation of the epidermal platelet-activating factor receptor results in ICAM-1
expression.
PMID- 10691036
TI - The effect of retinoic acid on the proportion of insulin cells in the developing
chick pancreas.
AB - We assessed the potential role of all-trans-retinoic acid on the developing chick
pancreas, specifically with regard to the proportions of insulin cells. The
endodermal component of the dorsal pancreatic bud of 5-d-old chick embryos was
cultured on Matrigel. Retinoic acid (10(-6) or 10(-5) M) was added to a standard
serum-free medium, Ham's F12 containing insulin, transferrin and selenium
(F12.ITS). Control grafts were cultured in F12.ITS alone or in F12.ITS with DMSO
(the diluent for retinoic acid). After 7 d the explants were retrieved, freeze
dried, vapor-fixed, and embedded in resin. Endocrine cell types were identified
by immunocytochemistry. The numbers of insulin cells were expressed as a
proportion of the sum of insulin plus glucagon cells. Retinoic acid had a dose
related effect; the proportion of insulin cells in explants treated with the
lower dose of retinoic acid (10(-6) M) was more than twice the proportion of
insulin cells in explants treated with the higher dose (10(-5) M) of retinoic
acid and more than three times that of the control grafts.
PMID- 10691037
TI - Partial cloning and sequencing of chick fibrillin-1 cDNA.
AB - The recent identification of numerous matrix genes and gene products has allowed
a detailed examination of their roles in development. Two of these extracellular
matrix proteins, fibrillin-1 and fibrillin-2, are components of the elastin
associated microfibrils. Given what is known about the distribution of the
fibrillins in normal tissues and the abnormalities that result when mutations
occur, a basic hypothesis has emerged: fibrillin-1 is primarily responsible for
load bearing and providing structural integrity, whereas fibrillin-2 may be a
director of elastogenesis. Nevertheless, examination of phenotypes in disorders
caused by mutations in fibrillin-1 or fibrillin-2 suggests some common functions.
To better understand these similar and diverse roles, it would be helpful to
examine these proteins during chick development. To accomplish this goal, it is
first necessary to characterize the chick homologs of the known fibrillins. In
this study, the partial chick FBN1 cDNA was identified by polymerase chain
reaction-aided cloning as a first step toward elucidating these goals. Sequence
analysis indicated that there is striking conservation between chick and
mammalian fibrillin-1 at the DNA and protein levels. Antisense and sense
riboprobes were synthesized and used in in situ hybridization in stage 14 chick
embryos and high levels of FBN1 transcripts were observed in the heart.
PMID- 10691038
TI - Establishment and characterization of a caprine mammary epithelial cell line
(CMEC).
AB - We describe the establishment of a continuous, nontransformed cell line obtained
from primary culture of a lactating (114 days postparturition) Anglo-Nubian
(Capra hircus) goat mammary gland biopsy. These cells (CMEC), have been cultured
in the presence of supraphysiologic concentrations of insulin and hydrocortisone
for more than 560 population doublings (over 80 passages) without any sign of
senescence while maintaining a normal/near-normal diploid chromosome modal number
of 2n = 60 and are responsive to contact inhibition of proliferation.
Cytoskeletal analysis indicates that CMECs are epithelial, without detectable
fibroblastic or myoepithelial cells. When grown at low density on plastic
substratum, the cells tend to form island monolayer aggregates with the
characteristic cobblestone morphology of epithelial cells. With increasing
density, the cells organize into lumen-like structures with various morphology
consisting of large and small vacuolized and nonvacuolized cells. Postconfluent
cultures form epithelial raised dome-like structures, implying a process of
contact-induced differentiation. This is corroborated by positive
immunocytochemistry to lactation-specific proteins: beta-casein and alpha
lactalbumin, which were predominantly expressed in dome-forming cells. We also
observed an overall modulation of cytokeratin 18/19 expression associated with
number of days post subculture and with the expression of lactation-specific
proteins. Postconfluent cultures which contain lactation-specific, antibody
reactive, dome-like structures showed a decreased expression of keratin 18 and no
(null) expression for keratin 19. Lastly, cells cultured within a collagen matrix
show morphological differentiation with the organization of branching duct-like
and acini-like structures. This study suggests that CMECs are a useful in vitro
model for study of mammary gland development and differentiation, in particular,
direct modulation of epithelial cells grown on plastic substratum or
extracellular matrix without the influence of stromal elements or the necessity
and variability associated with primary cell culture or tissue explants.
PMID- 10691039
TI - Organization of extracellular matrix components during differentiation of
adipocytes in long-term culture.
AB - Scanning electron microscopy (SEM) observation showed that fully differentiated
spherical adipocytes were embraced by a network of collagens and fibroblastic
preadipocytes. The properties of both the collagen networks and the preadipocytes
allow the adipocytes to be interconnected, forming a fat-cell cluster, which can
anchor to the bottom of a culture dish. In this network structure, collagen
fibrils and fibrillar bundles were closely arranged and stratified. We found that
immunostained collagens appeared to form extracellular network structures, which
can be observed by SEM. The extracellular network of fibronectin was the first to
develop among the extracellular matrix (ECM) components, though it became
degraded with the progress of adipocyte differentiation. The type I collagen
network was the last to develop and remained well organized through the late
stage of adipocyte differentiation. The extracellular networks of type III, V,
and VI collagen developed by the mid-stage and remained in the late stage of
adipocyte differentiation. The network structures of type IV collagen and laminin
became degraded during the differentiation process and localized at the surface
of spherical cells. In addition to these basement membrane components, types III,
V, and VI collagens also showed pericellular spherical staining patterns. These
results demonstrated that the constitution and distribution of the ECM are
altered during adipocyte differentiation, suggesting that the organization of
each ECM component into a suitable structure is a requirement for the
differentiation and maintenance of unilocular adipocytes.
PMID- 10691040
TI - Establishment of astrocyte cell lines from sheep genetically susceptible to
scrapie.
AB - Primary cultures of the brain from sheep embryos were used to establish cell
lines after transfection by the simian virus 40 (SV40) large T gene. Two of the
lines (A15 and 4A6) displayed astroglial properties. They expressed the glial
fibrillary acidic protein (GFAP), intermediate filament protein vimentin, and S
100 (beta-subunit) protein. While numerous rodent and human glial cell lines are
available, this is to our knowledge the first description of ovine cell lines
with astrocyte features. In addition, these cell lines were derived from sheep
embryos chosen for their genetic susceptibility to scrapie (PrP genotype: VV136,
QQ171). Therefore, they could be attractive tissue culture models for the study
of propagation and pathogenesis of the scrapie agent ex vivo.
PMID- 10691041
TI - Simultaneous measures of contraction and intracellular calcium in single,
cultured smooth muscle cells.
AB - Simple methods are presented for quantitating contraction and intracellular
calcium simultaneously in single, cultured smooth muscle cells. These methods are
the first to demonstrate that reliable velocities of cell shortening can be
measured in cultured smooth muscle cells and that cells in vitro exhibit
shortening velocities comparable to those measured in the fastest phasic muscles
in situ. Temporal relationships between changes in intracellular calcium and
shortening within single cells were determined with a resolution of 100 ms and
were consistent with measures in more "classical" preparations. Intracellular
calcium rose quickly and transiently 10-fold above the basal level of 80-90 nM in
response to the muscarinic agonist, carbachol. Shortening of the cells occurred
200 ms after intracellular calcium began to rise. The sensitivity and reliability
of these methods allowed the effects of different stimuli to be easily resolved.
The present report demonstrates that genuine contractility need not be ignored in
cultured smooth muscle cells and that the temporal relations between shortening
and intracellular calcium mobilization can be quantitatively assessed in
controlled in vitro environments.
PMID- 10691042
TI - Modulatory effect of rat small intestinal epithelial cell-conditioned medium on
lymphocyte proliferation.
AB - The small intestinal epithelium plays an important role in the mucosal host
defense. Intestinal epithelial cells have been known to release substances that
suppress lymphocyte proliferation, suggesting an immunoregulatory function. We
investigated how intestinal epithelial cells affect lymphocyte proliferation.
Serum-free medium that was conditioned by incubating epithelial cells,
particularly crypt cells, of the rat small intestine affected proliferation of
allogeneic spleen lymphocytes stimulated with concanavalin A, as assessed by
measuring cellular [3H]thymidine incorporation. Less than 1% and greater than 2%
of the conditioned medium enhanced and suppressed, respectively, lymphocyte
proliferation. The causative substances found in the conditioned medium were
dialyzable and heat-stable. Suppression was not due to toxicity to splenocytes.
Exposure of splenocytes to a suppressive concentration of the conditioned medium
beginning at 30 min before an onset of lectin stimulation decreased the
suppression of lymphocyte proliferation. Splenocyte exposure to the suppressive
concentration of the conditioned medium beginning at 30 min to 4 h after the
onset of the stimulation inversely strengthened the suppression. A brief exposure
of splenocytes to the conditioned medium for the last 4 h during a total 72-h
culture period still suppressed lymphocyte proliferation. Thus, intestinal
epithelial cells produce low-molecular-weight lymphocyte proliferation-modulating
substances that suppress the proliferation of lectin-activated lymphocytes, but
not resting ones, by affecting earlier intracellular events and the following DNA
synthesis when incubated in culture medium.
PMID- 10691043
TI - Cytotoxicity of TNT and its metabolites.
AB - The production and storage of explosives has resulted in the environmental
accumulation of 2,4,6-trinitrotoluene (TNT). The biotransformation products of
the nitroaromatic compound TNT and metabolites in mammalian cells in culture and
their cytotoxicity are studied. We report after our analysis by reverse phase
high performance liquid chromatography (HPLC) that the most prevalent
biotransformation product of TNT in the NG108 neuroblastoma cells is primarily
monoamino-dinitrotoluene (2Am-DNT). It causes toxic effects based on trypan blue
exclusion and LDH-release colorimetric assays.
PMID- 10691044
TI - Diagnosis of myocardial infarction: integration of serum markers and clinical
descriptors using information theory.
AB - OBJECTIVE: We examine the use of information theory applied to a single cardiac
troponin T (cTnT) (first generation monoclonal; Boehringer Mannheim Corp.,
Indianapolis, Indiana) used with the character of chest pain, electrocardiography
(ECG) and serial ECG changes in the evaluation of acute myocardial infarction
(AMI). We combined a single measure of cTnT (blinded to the investigators) with a
creatine kinase MB isoenzyme (CK-MB) measurement to discover the best decision
value for this test in a study of 293 consecutive patients presenting to the
emergency department with symptoms warranting exclusion of AMI. METHODS: The
decision value for determining whether cTnT is positive or negative was
determined independently of the final diagnosis by examining the information in
the cTnT and CKMB data. Using information theory, an autocorrelation matrix with
a one-to-one pairing of the CKMB and troponin T was constructed. The effective
information, also known as Kullback entropy, assigned the values for troponin T
and for CKMB that have the lowest frequency of misclassification error. The
Kullback entropy is determined by subtracting the data entropy from the maximum
entropy of the data set in which the information has been destroyed. The
assignment of the optimum decision values was made independently of the clinical
diagnoses without the construction of a receiver-operator characteristic curve
(ROC). The final diagnosis of AMI was independently determined by the clinicians
and entered into the medical record. RESULTS: The decision value for cTnT was 0.1
ng/ml as determined by the the information in the data. The method was validated
within the same study by mapping the results so obtained into the diagnoses
obtained independently by the clinicians using all of the methods at their
disposal. The cTnT was different in AMI (n = 60) compared with non-AMI patients
(n = 233) (2.08 +/- 0.21 vs. 0.07 +/- 0.10; p < .0001). CONCLUSION: Information
theory provides a strong framework and methodology for determining the decision
value for cTnT which minimizes misclassification errors at 0.1 ng/ml. The result
has a strong correlation with other features in detecting AMI in patients
presenting with chest pain.
PMID- 10691045
TI - A 70-year-old man with isolated weight loss and a pellagra-like syndrome due to
celiac disease.
AB - An elderly man was diagnosed with celiac disease, which presented with three
notable features: first, presentation at the age of 70 with no prior
gastrointestinal symptomatology or positive family history; second, triggering of
all symptoms following recent myocardial infarction and infective endocarditis;
third, presentation with marked (more than 20 percent) weight loss and pellagra
like skin lesions despite nearly normal examination and laboratory tests. Thus,
celiac disease may present as a pellagra-like syndrome in the elderly with
predominant weight loss that is enhanced by the related taste disturbances.
PMID- 10691046
TI - Advancing technologies in clinical medicine: the Yale-Mount Everest telemedicine
project.
PMID- 10691047
TI - Technical and cultural challenges of remote health care on Everest.
PMID- 10691048
TI - For once then, something...
PMID- 10691049
TI - Relationships among serum cystatin C, serum creatinine, lean tissue mass and
glomerular filtration rate in healthy adults.
AB - In an effort to increase our knowledge of the optimal use of serum cystatin C and
creatinine as glomerular filtration rate (GFR) markers, these variables, as well
as lean tissue mass and GFR, were determined in a population of 42 healthy young
adults (men and women with normal GFR). Dual-energy X-ray absorptiometry and
measurement of the plasma clearance of iohexol were used to measure lean tissue
mass and GFR, respectively. Serum creatinine was significantly correlated to lean
tissue mass (r=0.65; p < 0.0001) but not to GFR (1/creatinine vs. GFR: r=0.11;
p=0.106). In contrast, serum cystatin C correlated with GFR (1/cystatin C vs.
GFR: r=0.32; p=0.0387), especially in men (1/cystatin C vs. GFR: r=0.64;
p=0.0055), but not to lean tissue mass. These results might explain previous
observations that serum cystatin C seems to be a better marker for GFR than serum
creatinine, particularly for individuals with small to moderate decreases in GFR.
However, the results also show that the serum concentrations of both creatinine
and cystatin C are determined not only by GFR, but also by other factors. Since
these additional factors differ for cystatin C and creatinine, it seems justified
to use serum creatinine and cystatin C in conjunction to estimate GFR, at least
until it is known in what situations serum creatinine or cystatin C is the
preferable marker.
PMID- 10691050
TI - Importance of assay conditions in visualization and quantitation of serum
alkaline phosphatase isoenzymes separated by electrophoresis.
AB - The importance of separation and identification of serum alkaline phosphatase
(ALP; E.C. 3.1.3.1) fractions/isoenzymes has been frequently reported. Each serum
ALP fraction/isoenzyme quantitation has both practical and theoretical
importance. In the present work, serum was collected from Wistar rats and, in
identical experimental conditions, total serum ALP activity and serum ALP
electrophoretic fractions/isoenzymes activities were quantified. Different
results for both kinds of ALP activity were obtained when different buffers or
mixture of these buffers (carbonate/bicarbonate; 2-amino-2-methyl-1-propanol/HCl;
Veronal, sodium diethylbarbiturate/HCl), pH conditions (9.4 and 10.4) and
substrates (alpha- and beta-naphthyl phosphates) were used. Higher total serum
ALP activity was always observed with beta-naphthyl phosphate, independently of
the buffer (or mixture of buffers) and pH used. Electrophoresis allowed the
separation of two serum ALP fractions. Activity of both serum ALP electrophoretic
fractions was always higher with beta-naphthyl phosphate, except with
carbonate/bicarbonate pH 10.4. The effect of a change in pH was buffer- (or
mixture of buffers) and substrate-dependent; the addition of a second buffer (to
that previously used) was not always accompanied by an increase or decrease (of
the same magnitude) in our results. The results obtained with different buffers
(or mixture of buffers) were not identical with substrates and pH values. It is
concluded that (i) from the same electrophoretic separation of serum ALP
fractions/isoenzymes, different values for its activity can be obtained by
changing the assay conditions used for ALP visualization (revelation, staining);
(ii) the same assay conditions for quantitation of total serum ALP and serum ALP
electrophoretic fractions/isoenzymes should be used; (iii) the choice of assay
conditions should take into account the biochemical problem being studied in each
case.
PMID- 10691051
TI - Metabolic syndrome is associated with changes in D-mannose metabolism.
AB - Serum mannose concentration increases in diabetic patients and correlates closely
with blood glucose. In patients with glomerulonephritis, serum mannose and
mannose/glucose ratio positively correlate with dyslipidemia and the extent of
urinary protein excretion. We investigated whether changes in serum mannose mark
subjects with features of metabolic syndrome, including obesity, hypertension,
glucose intolerance, and dyslipidemia. The study comprised 20 patients with mean
age of 68 (SD 11) years, body mass index 27.2 (SD 5.1) kg/m2, blood glucose 6.2
(SD 1.6) mmol/L, serum total cholesterol 6.3 (SD 1.2) mmol/L, triglyceride 2.0
(SD 0.08) mmol/L, uric acid 320 (SD 109) micromol/L, mannose 60.0 (SD 17)
micromol/L, and mannose/glucose ratio 9.7 (SD 1.8) micromol/mmol. Serum mannose
correlated with blood glucose (r=0.758, p=0.012), triglyceride (r=0.478,
p=0.023), and HDL-cholesterol (r = approximately 0.427, p=0.022). Mannose/glucose
ratio correlated with BMI (r=0.581, p=0.033), mannose (r=0.491, p=0.035), and
uric acid (r=0.608, p=0.027). The rate of VLDL lipoprotein turnover may be
instrumental in the regulation of serum mannose concentration. We conclude that
an altered mannose metabolism is a novel consideration among the metabolic
abnormalities in the metabolic syndrome.
PMID- 10691052
TI - Variant transthyretin (TTR) amyloidosis in Argentina. Detection of the trait by
electrospray ionization mass spectrometry of lyophilized TTR immunoprecipitate.
AB - We have developed a quick and reliable diagnostic method for detecting variant
forms of transthyretin (TTR); namely, centrifugal concentration followed by
electrospray ionization mass spectrometry (ESI-MS). Argentinian patients from
three families with neuropathic amyloidosis and their relatives were screened for
mutated TTR by ESI-MS. In order to facilitate transportation, we investigated the
impact storage had on lyophilized anti-TTR-antibody precipitates' mass spectra.
For this investigation, plasma samples from three Swedish patients with known TTR
amyloidosis were analysed. We detected identical, additional peaks corresponding
to a variant form of TTR in 10 members of the families, and also in a lyophilized
sample sent unfrozen by mail from Argentina. All except one symptomatic subject
had additional peaks, the exception having undergone a liver transplantation for
the disease. All patients were early onset cases, i.e. below 35 years of age, and
family history suggests an aggressive, rapidly progressing disease. Lyophilized
anti-TTR-antibody precipitates stored at room temperature for 1 week exhibited
only minor differences compared with plasma samples stored at -70 degrees C. In a
new Argentinian study on familial amyloidotic polyneuropathy, the variant TTR was
quickly identified and typed by ESI-MS. To facilitate transportation, dry-frozen
samples can be used and the quality of the spectra is similar to that of samples
stored at -70 degrees C.
PMID- 10691053
TI - Accuracy of pleural fluid pH and PCO2 measurement in a blood gas analyser.
Analysis of bias and precision.
AB - Pleural fluid pH measurements are used in the management of parapneumonic
effusions. This study evaluated the accuracy of the pleural fluid pH and PCO2
measurement in a blood gas analyser (BGA) and the error induced by altering the
aerobic environment and temperature of sample storage prior to analysis. The pH
electrodes in a pH meter and a BGA were initially evaluated using aqueous
reference solutions. The accuracy of pH and PCO2 electrodes was then assessed in
pleural fluid tonometered to a known PCO2. The effects of aerobic compared to
anaerobic storage and storage temperature, 0 degrees C vs 37 degrees C of pleural
fluid were evaluated for errors in pH and PCO2 measurement. The BGA and the pH
meter measured pleural pH with negligible bias and imprecision (0.01+/-0.01 pH
units). The PCO2 measurement bias and imprecision of the BGA was small: 1.8+/
0.57 torr (0.2+/-0.08 kPa) at 2% CO2, 0.1+/-0.93 torr (-0.01+/-0.1 kPa) at 5% CO2
and -3.77+/-0.81 (-0.5+/-0.1 kPa) torr at 10% CO2 level. Aerobic storage resulted
in a clinically important overestimation of pleural fluid pH by both the pH meter
and the BGA of 0.14-0.16 pH units (p<0.05). No significant differences were
detected when storage at 0 degrees C was compared to that at 37 degrees C. A BGA
is reliable for pleural fluid pH measurements. Pleural fluid PCO2 measurements in
a BGA have a concentration-dependent bias and imprecision. Anaerobic storage of
specimens for pleural pH and PCO2 analysis is mandatory.
PMID- 10691054
TI - Hepatic and renal extraction of circulating type I procollagen aminopropeptide in
patients with normal liver function and in patients with alcoholic cirrhosis.
AB - The circulating level and splanchnic and renal extraction of serum type I
procollagen aminoterminal propeptide (PINP) was studied in 20 patients with
normal liver function and in 15 patients with alcoholic liver cirrhosis. In
patients with alcoholic cirrhosis, the concentration of PINP in the femoral
artery blood was significantly higher than in the group of patients with normal
liver function (median 145 microg/l, 95% CI 98-195 versus 57 microg/l, 95% CI 42
92, p<0.001). A significant decrease in the concentration of PINP between the
femoral artery (median 57 microg/l, 95% CI 42-92) and the hepatic vein (median 45
microg/l, 95% CI 40-70, p<0.001) was found in patients with normal liver
function. In this group we also observed a significantly higher concentration of
PINP in femoral artery blood (median 60 microg/l, 95% CI 45-87) as compared with
that in renal vein (median 50 microg/l, 95% CI 40-65, p<0.001). In contrast,
serum-PINP did not differ between arterial and hepatic or venous venous blood in
patients with alcoholic cirrhosis. Size-chromatography revealed no significant
change in the ratio of the high and low molecular forms of PINP following
extraction in liver and kidney. It is concluded that circulating PINP is
extracted in the normal liver and kidney, and that the serum concentration of
PINP is significantly higher in patients with alcoholic cirrhosis than in
patients with normal liver function. Both the hepatic and the renal clearance of
PINP are seriously impaired/reduced in patients with alcoholic cirrhosis.
PMID- 10691055
TI - Sensitive and quantitative one-step polymerase chain reaction using capillary
electrophoresis and fluorescence detection for measuring cytokeratin 19
expression.
AB - An improved quantitative assay to measure cytokeratin 19 (CK19) expression has
been developed. The assay utilizes reverse transcription and a one-step
polymerase chain reaction (PCR), with capillary electrophoresis and fluorescent
labelling, to separate and detect the PCR products. Calibration curves were
constructed from a serial dilution of CK19 cDNA coamplified with a fixed amount
of CK19 internal standard, which was found to be linear between 10 and 500
molecules. Quantitative measurement of CK19 in samples was carried out by
coamplifying the cDNA with a fixed amount of internal standard. The values were
calculated from the calibration curve. The integrity of RNA and cDNA synthesis
was checked by quantitative measurement of the breakpoint cluster region (BCR)
gene expression. The assay is sensitive, detecting < 10 CK19 transcripts, and
reproducible with a coefficient of variation of approximately 10%. CK19
expression showed overlapping values when measured in samples from peripheral
blood and bone marrow in operable breast cancer patients, in healthy volunteers
or patients without epithelial cancer and in blood samples from patients with
metastatic breast cancer. As the assay is easier to perform than traditional
quantitative competitive PCR assays, it might be useful for quantitative
measurement of other specific transcripts.
PMID- 10691056
TI - Rapid MEN 2A gene carrier identification using primer-specific PCR amplification.
AB - DNA testing is of great importance in families with multiple endocrine neoplasia
(MEN) type 2A to identify non-mutant carrying family members and asymptomatic
mutation carriers, and also to confirm the diagnosis in patients who already show
clinical or biochemical signs of disease. Several point mutations of the RET
proto-oncogene on exons 10 and 11 are associated with the disease, which is
characterized by medullary thyroid carcinoma, pheochromocytoma and
hyperparathyroidism. The aim of the present study was to develop and evaluate a
simple method, which indicates the mutational status of members of families where
the site of the point mutation is known. The method is illustrated by the
detection of mutation TGC-->TAC of codon 611, which is one of the well-known
mutations associated with MEN 2A. The method involves the PCR technique with
allele-specific primers and detection of the amplified sequences with
biotinylated probes. There was a clear-cut difference between the readings from
affected and unaffected subjects. The subjects had been evaluated independently
and all subjects harboring the mutation also had clinical disease. The method
provides a simple and reliable diagnostic tool for DNA screening of members of
families with a known mutation of the RET-gene.
PMID- 10691057
TI - Computerized measurement of LDL particle size in human serum. Reproducibility
studies and evaluation of LDL particle size in relation to metabolic variables
and the occurrence of atherosclerosis.
AB - OBJECTIVES: The main aims of the present research project were to develop and
evaluate a new software program for evaluation of LDL particle size applied to
the gradient gel electrophoresis methodology without the use of previous
ultracentrifugation, and to investigate the relationships among LDL particle
size, metabolic variables and atherosclerosis, as measured by ultrasound, in
subjects with different degrees of insulin resistance. METHODS: LDL particle size
was determined by polyacrylamide gradient gel electrophoresis. RESULTS:
Coefficient of variation for between-assay experiments was 0.3% (r = 0.99) for
measurement of LDL peak particle size. LDL peak particle size was negatively
correlated to serum triglycerides, apolipoprotein B, fasting insulin, BMI and
diastolic blood pressure and positively correlated to HDL. Furthermore, subjects
with moderate to large plaques in the carotid artery had smaller LDL particles
compared to subjects without plaques. CONCLUSIONS: This project resulted in a
highly reproducible, computerized method for the analysis of LDL particle size.
The data suggest that it is possible to assess LDL particle size in serum without
the use of previous ultra-centrifugation. LDL particle size was associated with
metabolic variables and the occurrence of moderate to large plaques in the
carotid artery.
PMID- 10691058
TI - Improved method for non-denaturing polyacrylamide gradient gel electrophoresis
for detection of small-sized LDL produced during postprandial
hypertriglyceridaemia.
AB - A reliable method for detection of small-sized low-density lipoprotein (LDL)
produced during transient hypertriglyceridaemia induced by ingestion of fat is
described. Electrophoresis using a commercial non-denaturing 2.0-16%
polyacrylamide gradient gel is commonly utilized to determine the size of LDL
particles, but it failed to detect a minor change in LDL size induced during
postprandial hypertriglyceridaemia. Detection of small-sized LDL was achieved by
adjusting the polyacrylamide concentration. Electrophoresis using a non
denaturing 1.5-10% polyacrylamide gradient gel gave the best resolution for
detecting small-sized LDL induced during postprandial hypertriglyceridaemia. This
improved method may be useful for elucidating the underlying mechanism of
production of small-sized LDL (small dense LDL) in subjects with chronic
hypertriglyceridaemia.
PMID- 10691059
TI - The disease profile of Texas prison inmates.
PMID- 10691060
TI - The disease profile of Texas prison inmates.
AB - PURPOSE: Whereas prison inmates are reported to exhibit poorer overall health
status and higher rates of health care utilization than the general population,
no current information exists on the overall disease profile of the U.S. prison
population. The present study examined the prevalence of major acute and chronic
conditions in one of the nation's largest prison populations. METHODS: The study
population consisted of 170,215 Texas Department of Criminal Justice (TDCJ)
inmates who were incarcerated between August 1997 and July 1998. Information on
medical conditions and sociodemographic factors was obtained from an institution
wide medical information system. RESULTS: Infectious diseases (29.6%) constituted
the most prevalent major disease category among inmates. This was followed by
diseases of the musculoskeletal system and connective tissue (15.3%), diseases of
the circulatory system (14.0%), mental disorders (10.8%), and diseases of the
respiratory system (6.3%). Among the specific conditions examined, evidence of
tuberculosis infection without active pulmonary disease (20.1%) was found to be
the most prevalent condition, followed by hypertension (9.8%), asthma (5.2%), low
back pain (5.1%), and viral hepatitis (5.0%). CONCLUSIONS: The present study
shows that for a number of conditions, the prison population exhibited prevalence
rates that were substantially higher than those reported for the general
population. Moreover, estimates for a number of diseases varied substantially
according to age, race, and gender. Understanding the disease profile in U.S.
incarcerated populations will permit correctional administrators to develop more
efficient health care delivery systems for prison inmates.
PMID- 10691061
TI - Application of computer tomography-oriented criteria for stroke subtype
classification in a prospective study.
AB - PURPOSE: To apply stroke subclassification criteria based on computer tomography
(CT) to strokes in the Nurses' Health Study and to assess reliability and
validity of the criteria. METHODS: Among 121,701 women aged 30-55 years at entry,
subclassification criteria were applied to 1369 incident strokes which occurred
from 1976 to 1994. Reproducibility of the subclassification criteria was assessed
in a systematic sample of 100 strokes reviewed by two independent reviewers. As a
validation, relative risks (RR) for stroke subtypes were examined in a
prospective analysis of 112,282 women aged 34 to 59 years, free of cardiovascular
disease and cancer in 1980, with follow-up through 1994. RESULTS: Strokes were
subclassified as follows: 226 subarachnoid hemorrhages, 135 intraparenchymal
hemorrhages, 103 embolic, 217 large-artery occlusive, 309 lacunar, and 97 other
thrombotic infarctions, as well as 282 strokes of undetermined type. No
intercoder discrepancies were found in classification of subarachnoid hemorrhage,
intraparenchymal hemorrhage, or embolic infarction, whereas there were four
discrepancies relative to subclassification of thrombotic infarction, mostly due
to inconsistent documentation of CT findings. In multivariate models,
associations of older age (> 60 years), current smoking, history of diabetes, and
high cholesterol with stroke subtypes were consistent with previous
epidemiologic, clinical, or pathologic findings. CONCLUSIONS: Stroke diagnostic
criteria based primarily on CT were found to have a high rate of reliability and
validity. These stroke subclassification criteria may be useful in examining
whether associations for various lifestyle and health behaviors differ with
stroke subtypes.
PMID- 10691062
TI - Measuring the projected public health impact of lung cancer through lifetime and
age-conditional risk estimates.
AB - PURPOSE: Lifetime and age-conditional probability (risk) estimates of developing
lung cancer in the United States are presented by age, race, and gender. Effects
on the risk estimates of an aging population and changing tobacco use are
identified. METHODS: Risk estimates were derived by applying cross-sectional,
population-based incidence rates of malignant lung cancer and mortality rates
from other causes to a hypothetical cohort. The cohort was aged through a double
decrement life table to determine the expected proportion of the population that
would develop the disease across age intervals. Incidence and mortality data were
obtained from the Surveillance, Epidemiology, and End Results (SEER) Program and
the National Centers for Health Statistics, respectively. RESULTS: Among all
cancers, risk estimates of developing lung cancer within 10 years, conditioned on
being free of the disease at age 50, 60, or 70, ranked second to prostate cancer
for men and second to breast cancer for women. For men, despite higher incidence
rates of lung cancer for blacks than whites across most age groups, the risk of
developing this disease over the life-span becomes similar, because white men are
more likely to live to older ages where lung cancer is common. For women, lung
cancer incidence rates are similar between Whites and Blacks, but an older age
distribution among white women explains their greater lifetime risk of being
diagnosed with the disease. Changes in the age distribution between the mid 1970s
and the mid 1990s had little impact on the short-term risk estimates of
developing lung cancer for younger ages but had a large influence on long-term
risk estimates, particularly for the older age groups. CONCLUSIONS: Declining
lung cancer among younger age groups may be attributed to declining tobacco use
among the cohorts, but several more years may be required before the trends begin
to fall in older age groups, particularly in women. In the meantime, an aging
population is contributing to more people being diagnosed with lung cancer.
Consequently, the projected risk of developing lung cancer will remain high for
several years to come.
PMID- 10691063
TI - Endometrial cancer in Olmsted County, MN: trends in incidence, risk factors and
survival.
AB - PURPOSE: We updated an earlier study in this community from 1945-1974 in order to
assess trends in the incidence of, risk factors for, and survival from
endometrial cancer in 1975-1991. METHODS: Incidence rates were based on all new
cases of endometrial cancer diagnosed among Olmsted County, Minnesota, women
during the years 1975-1991, with the population denominator from decennial census
data. Risk factors were assessed with conditional logistic regression comparing
the incidence cases to age- and gender-matched controls with intact uteri seen
the same year the case was diagnosed. Survival was assessed using the Kaplan
Meier method. RESULTS: The incidence of endometrial cancer (age-adjusted to 1970
United States total) in 1975-1991 was 14.3 per 100,000 person-years, which is
slightly increased from 1965-74. The rate was 21.7 per 100,000 person-years after
adjustment for hysterectomy prevalence. As in the previous study, conjugated
estrogen use for six months or more (odds ratio [OR] 2.71; 95% confidence
interval [CI] 1.14-6.46) and body mass index (OR 1.06; 95% CI 1.01-1.11)
increased the risk of endometrial cancer. The five-year relative survival rate
(82%) was not improved over the earlier study. CONCLUSIONS: A small increase in
endometrial cancer incidence was linked to the same risk factors identified in an
earlier study in this community. No improvement in survival was seen.
PMID- 10691064
TI - Serum vitamins, carotenoids, and angina pectoris: findings from the National
Health and Nutrition Examination Survey III.
AB - PURPOSE: Whether various vitamins and carotenoids can protect against ischemic
heart disease remains an unsettled question. METHODS: We performed a cross
sectional analysis of data from National Health and Nutrition Examination Survey
III (1988-1994) and examined the associations between serum vitamins A, C, E, and
B12, serum folate, red blood cell folate, serum carotenoids, and angina pectoris
in a representative population-based sample of 11,327 men and women aged 35->90
years. RESULTS: After adjusting for age, sex, race or ethnicity, education,
smoking status, systolic blood pressure, serum cholesterol, high-density
lipoprotein cholesterol, history of diabetes mellitus, body mass index, and
physical activity with multiple logistic regression analysis, no significant
associations were present for any of the serum vitamin concentrations and angina
pectoris. Significant linear trends were observed for serum concentrations of
alpha-carotene (p < 0.001), beta-carotene (p = 0.026), and beta-cryptoxanthin (p
= 0.003). Compared with participants with carotenoid concentrations in the lowest
quartile, participants with concentrations in the highest quartile had odds
ratios for angina pectoris of 0.45 (95% confidence interval (CI) 0.31-0.65), 0.57
(95% CI 0.38-0.86), and 0.57 (95% CI 0.38-0.84) for alpha-carotene, beta
carotene, and beta-cryptoxanthin, respectively. CONCLUSIONS: These results
provide little support for a cross-sectional association between angina pectoris
and serum and red blood cell folate concentrations or concentrations of vitamins
A, C, E, and B12. Several serum carotenoid concentrations were associated with a
reduced risk for angina pectoris, however.
PMID- 10691065
TI - Effects on subject response of information brochures and small cash incentives in
a mail-based case-control study.
AB - PURPOSE: To investigate the impact on subject response of an information brochure
and cash incentives included with mailed questionnaires in case-control studies.
METHODS: A randomized trial was carried out within a case-control study
investigating cancer in the Province of Ontario. Brochures were included with
half of the mailed questionnaires sent to 7487 cases and 2561 controls. Controls
were also sent cash incentives of $2, $5, or no money. RESULTS: With the
brochure, response changed from 75.0% to 75.8% in cases, and from 70.3% to 71.1%
in controls. Adjusting for differences in age, residence, sex, and cancer
site/status, the change was 0.2% [95% confidence interval (CI) = -1.7-2.1] in
cases, and 0.6% (95% CI = -3.1-4.3) in controls. The $2 and $5 incentives
increased overall response in controls from 61.9% to 72.8% and 77.2%,
respectively, i.e., by 10.9% (95% CI = 6.1-15.6) and 15.1% (95% CI = 10.4-19.7),
after adjustment. This effect was largely confined to urban areas (for $2 and $5,
respectively: 5.5% and 14.2% in Toronto, 15.3% and 20.4% in other urban areas vs.
2.7% and 1.0% in rural areas; p = 0.02). Response time showed little or no
improvement when the brochure was included, but was markedly reduced for both the
$2 and $5 incentives. CONCLUSIONS: Cash incentives can improve subject response
in epidemiologic studies, whereas information brochures do not appear to have an
effect.
PMID- 10691067
TI - Bier block exsanguination: a volumetric comparison and venous pressure study.
AB - OBJECTIVES: Intravenous regional anesthesia (IVRA) is a useful ED anesthetic
technique. However, venous pressure elevation during injection can cause
anesthetic leakage and toxicity. This is minimized by preinjection limb
exsanguination. Although standard, Esmarch exsanguination is intolerable with
limb trauma. Thus, the authors' objective was to study alternative methods.
METHODS: Volunteers had upper limb exsanguination performed by Esmarch bandage,
arm elevation/arterial compression (AE/AC), and a pneumatic vinyl splint.
Resultant volume changes, measured by volume displacement, were normalized, and
expressed as percent decreases from baseline. Volume changes of all three methods
were compared. The physiologic effectiveness of the AE/AC method was tested by
measuring IV pressures during simulated IVRA. Attainment of maximum venous
pressure (MVP) indicated leakage under the tourniquet. RESULTS: All methods
reduced limb volume compared with baseline (p < 0.05). No difference occurred
between AE/AC and vinyl splint exsanguination (p > 0.99), but neither method was
as effective as Esmarch (p < 0.05). Gender differences were noted in absolute
volumes exsanguinated, but there was no difference in percent exsanguination. The
AE/AC method was the simplest procedure to perform. Peak IV pressure during
simulated IVRA after AE/AC was 85 mm Hg (males), and 199 mm Hg (females) (p <
0.05). The MVP was not reached. CONCLUSIONS: While Esmarch was the most effective
exsanguinating method, the two alternatives provided significant and equivalent
decreases in limb volume. The AE/AC technique was physiologically effective in
preventing attainment of MVP. Further studies are indicated to determine the
clinical effectiveness of this technique in providing anesthesia for patients
with limb trauma.
PMID- 10691066
TI - Design of Physicians' Health Study II--a randomized trial of beta-carotene,
vitamins E and C, and multivitamins, in prevention of cancer, cardiovascular
disease, and eye disease, and review of results of completed trials.
AB - PURPOSE: To assess the balance of benefits and risks of supplementation with beta
carotene, vitamin E, vitamin C, and multivitamins on cancer, cardiovascular
(CVD), and eye diseases. DESIGN: Physicians' Health Study II (PHS II) is a
randomized, double-blind, placebo-controlled trial enrolling 15,000 willing and
eligible physicians aged 55 years and older. PHS II will utilize a 2 x 2 x 2 x 2
factorial design to test alternate day beta-carotene, alternate day vitamin E,
daily vitamin C, and a daily multivitamin, in the prevention of total and
prostate cancer, CVD, and the age-related eye diseases, cataract and macular
degeneration. PRIOR RESULTS: The final results of the recently completed
Physicians' Health Study I (PHS I), a randomized, double-blind, placebo
controlled trial in 22,071 healthy US male physicians, indicated that beta
carotene supplementation (50 mg on alternate days) had no significant benefit or
harm on cancer or CVD during more than 12 years of treatment and follow-up. In
regards to cancer, there were possible benefits on total and prostate cancer in
those with low baseline levels assigned to beta-carotene, a finding compatible
with the Chinese Cancer Prevention Study for combined treatment with beta
carotene, vitamin E, and selenium in a poorly nourished population. Further, with
respect to CVD, there were apparent benefits of beta-carotene supplementation on
subsequent vascular events among a small subgroup of 333 men with prior angina or
revascularization. The currently available data from randomized trials of primary
prevention are sparse and inconsistent for vitamin E and non-existent for vitamin
C and multivitamins. For eye diseases, namely cataract and age-related macular
degeneration, there are no completed large-scale randomized trials of antioxidant
vitamins. CONCLUSIONS: PHS II is unique in several respects. PHS II is the only
primary prevention trial in apparently healthy men testing the balance of
benefits and risks of vitamin E on cancer and CVD. In addition, PHS II is the
only primary prevention trial in apparently healthy men to test the balance of
benefits and risks of vitamin C, multivitamins, as well as any single antioxidant
vitamin, alone and in combination, on cancer, CVD, and eye diseases. Finally, PHS
II is the only trial testing a priori the hypotheses that beta-carotene and
vitamin E may reduce the risks of prostate cancer. Thus, PHS II will add unique
as well as importantly relevant and complementary information to the totality of
evidence from other completed and ongoing large-scale randomized trials on the
balance of benefits and risks of beta-carotene, vitamin E, vitamin C, and
multivitamins alone and in combination on prevention of cancer, CVD and eye
diseases.
PMID- 10691068
TI - The effects of epidermal debridement of partial-thickness burns on infection and
reepithelialization in swine.
AB - OBJECTIVE: Early postburn debridement of burn blisters is controversial. This
study was conducted to compare rates of infection and reepithelialization in
debrided vs nondebrided second-degree burns in swine. METHODS: This was a
prospective, blinded, controlled, experimental trial using isoflurane
anesthetized swine. Standardized partial-thickness burns were inflicted by
applying an aluminum bar preheated to 80 degrees C to the backs and flanks of two
young pigs for 20 seconds. In half of the burns the necrotic epidermis was
manually debrided. All burns were randomly treated with octylcyanoacrylate spray
(OCA) or dry gauze (C). Full-thickness biopsies were taken at 7, 10, and 14 days
for blinded histopathologic evaluation. The primary outcomes were the proportions
of infected burns at days 7 and 10 and the proportion of completely
reepithelialized burns at day 14. Burns were considered infected in the presence
of intradermal neutrophils containing bacteria (intraobserver agreement, K =
1.00). A secondary outcome was the proportion of burns with the presence of scar
tissue (abnormal collagen under polarized light; intraobserver correlation, K =
0.93). Chi-square tests were used for group comparisons. This study had 90% power
to detect a 40-percentage-point difference in infection rates (alpha = 0.05).
RESULTS: A total of 126 biopsies from 42 burns were available for review.
Infection rates were higher in the debrided burns both at day 7 (55% vs 4.5%, p <
0.001) and at day 10 (65% vs 9%, p < 0.001) after injury. The proportion of
nondebrided burns that were completely reepithelialized was higher at days 10
(68% vs 0%, p < 0.001) and 14 (100% vs 65%, p = 0.003). The presence of scar
tissue was more common in debrided burns (75% vs 4.5%, p < 0.001). Burns treated
with OCA had fewer infections than controls (4% vs 55%, p < 0.001). Fewer OCA
treated debrided burns were reepithelialized at 14 days than those that were not
debrided (30% vs 100%, p = 0.001). CONCLUSIONS: Under the current study
conditions, early postburn epidermal debridement of second-degree burns resulted
in more infections and slower reepithelialization rates in swine. The effects of
early postburn epidermal debridement in humans should be explored.
PMID- 10691069
TI - Lower-extremity Doppler for deep venous thrombosis--can emergency physicians be
accurate and fast?
AB - Clinical diagnosis of lower-extremity (LE) deep venous thrombosis (DVT) requires
confirmation by an imaging study before committing the patient to anticoagulation
therapy. Studies have shown that demonstrating compressibility of leg veins under
ultrasound is accurate for ruling out DVTs when performed by vascular
specialists. Although LE Doppler has become the preferred test for diagnosing
DVTs, it is not always available 24 hours per day. OBJECTIVES: To evaluate the
accuracy and speed with which emergency physicians (EPs) could perform LE color
duplex ultrasonography for the detection of DVT. METHODS: Patients presenting to
an urban community emergency department (ED) between August 1, 1998, and March 3,
1999, were enrolled into this prospective study. The EPs, who underwent brief and
standardized training, scanned patients at high risk for DVT with leg pain,
swelling, or both. Physicians performed color duplex ultrasound examinations with
compression at the common femoral and popliteal veins. The time until completion
of the ED scan was recorded with a standardized method. The vascular laboratory
performed a complete duplex ultrasound examination within eight hours. RESULTS:
One hundred twelve patients were enrolled in the study, with 34 positive for DVT.
The median examination time was 3 minutes 28 seconds (95% CI = 2 min 45 sec to 4
min 2 sec; IQR 3 min 9 sec). Times ranged from 1:02 to 18:20 minutes. The ED
results had a high correlation with vascular laboratory studies, giving a kappa
of 0.9 and a 98% agreement (95% CI = 95.4% to 100%). CONCLUSION: Emergency
physicians can perform LE duplex ultrasound examinations accurately and quickly.
PMID- 10691070
TI - Out-of-hospital intravenous cannulation: the perspective of patients treated by
London Ambulance Service paramedics.
AB - OBJECTIVES: Previous research has highlighted concern about infection rates in
field-placed intravenous (IV) cannulae. In a study of IV placement by London
Ambulance Service (LAS) paramedics, 17% of placements were judged to be
inappropriate. Large variations in rates of IV placement between LAS paramedics
were found. The authors' hypothesis was that placement of an IV carries
disadvantages-pain, discomfort, distress, and infection-which may be unacceptable
to patients. METHODS: This was a survey of all patients having an IV placed by
LAS paramedics and transported to one of three London emergency departments (EDs)
over a three-week period in December 1996. Patients were excluded if they had a
self-inflicted injury/illness, were less than 14 years old, had no known address,
or were visitors to the UK, or if their family doctor suggested it was not
appropriate to contact the patient. Pain, discomfort, and distress; infection;
satisfaction; understanding of the reason for cannulation; and out-of-hospital
cannula use were all ascertained and analyzed with chi-square analysis. RESULTS:
Thirty-nine percent of the respondents experienced some discomfort, 39% some
pain, and 17% some distress. No patient reported an infection. Distress was more
likely to be reported if there was no understanding of why the IV cannula was
placed (chi2 [1] 6.1; p < 0.05). Further unstructured information revealed
satisfaction with the IV cannulation and with general care. CONCLUSIONS: Despite
the disadvantages of IV placement being reported by some respondents, overall
levels of satisfaction were high, suggesting that these disadvantages were not
unacceptable to patients. However, in the context of the 24,000 patients
cannulated each year by LAS paramedics, "costs" to the patient are considerable.
PMID- 10691071
TI - Traumatic brain injuries evaluated in U.S. emergency departments, 1992-1994.
AB - OBJECTIVE: To describe the incidence and patient characteristics of traumatic
brain injuries (TBIs) treated in U.S. emergency departments (EDs). METHODS: A
secondary analysis was performed on data from the National Hospital Ambulatory
Medical Care Survey administered from 1992 to 1994. An ED visit was determined to
represent a case of TBI if the case record contained ICD-9-CM codes of 800.0
801.9, 803.0-804.9, or 850.0-854.1. RESULTS: The average annual estimate of new
TBI treated in U.S. EDs was 1,144,807, equaling 444 per 100,000 persons (95% CI =
390 to 498), which represents approximately 3,136 new cases of TBI per day and
accounts for 1.3% of all ED visits. Males were 1.6 times as likely as females to
suffer TBI until the age of 65 years, when the female rate exceeded the male. The
rate for blacks was 35% higher than that for whites. The highest overall
incidence rate of TBI occurred in the less-than-5-year age group (1,091 per
100,000), closely followed by the more-than-85-year age group (1,026 per
100,000). Falls represented the most common mechanism of TBI injury, followed by
motor vehicle-related trauma. CONCLUSIONS: This study underscores the ongoing
need for effective surveillance of all types of TBI and evaluation of prevention
strategies targeting high-risk individuals. It serves as a clinically grounded
and ED-based corroboration of prior survey research, providing a basis for
comparison of incidence rates over time and a tool with which to measure the
efficacy of future interventions.
PMID- 10691072
TI - Pantomography vs mandibular series for the detection of mandibular fractures.
AB - OBJECTIVE: The two primary radiographic techniques used for the evaluation of
mandible injury are a pantomographic series (PS) and the standard four-view
mandibular series (MS). Despite a tenuous foundation, there is apparent bias in
favor of PS compared with MS. Many emergency departments do not have ready access
to the specialized equipment necessary to perform a pantomographic study. The
hypothesis of this study was that a high-quality standard MS is as sensitive and
specific as a PS in the detection of mandibular fractures. METHODS: This was a
prospective, blinded study of 54 patients presenting with acute mandibular injury
comparing MS and PS. The study design used two board-certified emergency
physicians and a single staff radiologist who read a series of MS and PS films in
a randomized fashion without access to clinical information or identifying
patient data. The absolute number of fractures present was determined by a
neuroradiologist with access to both MS and PS simultaneously as well as
pertinent clinical information. RESULTS: Thirty patients had 47 mandibular
fractures. The sensitivity for fracture detection for each physician was 0.85,
0.77, and 0.89 with MS and 0.79, 0.74, and 0.83 with PS (p > or = 0.51, p > or =
1.00, and p > or = 0.51, respectively, McNemar's binomial test). The specificity
for fracture detection for each physician was 0.88, 0.92, and 0.96 for MS and
0.96, 1.00, and 0.92 for PS (p > 0.625, p > 0.50, and p = 1.00, respectively,
McNemar's binomial test). CONCLUSIONS: A standard mandibular series is as
sensitive and specific as pantomography in the detection of mandibular fractures.
PMID- 10691074
TI - Primary closure of mammalian bites.
AB - OBJECTIVE: Suturing of bite wounds remains controversial. The authors evaluated
the incidence of wound infection in 145 mammalian bite wounds treated with
primary closure. METHODS: Consecutive patients with bite wounds receiving primary
closure at a university hospital ED had structured closed-question data sheets
completed at the time of wound management and suture removal. Infection was
determined at the time of suture removal using a previously validated definition.
Data included demographics; medical history; time from injury to evaluation;
wound characteristics and location; details of wound cleansing methods,
debridement, foreign body removal, and wound closure methods; use of antibiotics;
and follow-up wound evaluation. Proportions and 95% confidence intervals were
calculated. RESULTS: One hundred forty-five mammalian bite patients were
enrolled: 88 dog, 45 cat, and 12 human bites. Patients had a mean (+/-SD) age of
21 +/- 20 years; 58% were male; 86% were white; and they presented a mean (+/-SD)
of 1.8 +/- 1.2 hours after injury. Bites occurred on the head and neck (57%),
upper extremity (36%), and lower extremity (6%). Wounds had a mean length and
width of 2.5 cm and 4.8 mm, respectively. Twelve percent involved structures deep
to subcutaneous tissue. After primary wound closure, wound infections occurred in
eight patients (5.5%; 95% confidence interval = 1.8% to 9.2%). CONCLUSIONS: The
data suggest that carefully selected mammalian bite wounds can be sutured with
approximately a 6% rate of infection. This infection rate may be acceptable in
lacerations where cosmesis is a primary concern.
PMID- 10691073
TI - Evaluation of the physician's ability to recognize the presence or absence of
anemia, fever, and jaundice.
AB - OBJECTIVE: The evaluation of the patient through a comprehensive history and
physical examination is considered the cornerstone of medical diagnosis, but many
studies suggest that physicians have inadequate physical examination skills. It
is unknown whether these skills are reliable and whether they can be adequately
acquired through training. The objective of this study was to evaluate the
ability of the clinician to detect the presence and discriminate the extent of
clinical anemia, fever, and jaundice in an ED or hospitalized patient. METHODS:
This was a prospective observational study of a convenience sample of patients
presenting to the ED or admitted to the hospital who had a rectal temperature
measurement within 30 minutes prior to the observation, serum hematocrit
measurement on the day of observation, or serum bilirubin measurement one day
prior to the day of observation. Observers' (emergency medicine attending
physicians', resident physicians', and rotating medical students') estimated
serum hematocrit, rectal temperature, and serum bilirubin values were obtained
after each observation. Sensitivity, specificity, positive predictive value,
negative predictive value, and mean absolute difference between actual and
estimated values were calculated for each observer. RESULTS: The physicians
detected the presence or absence of anemia, fever, and jaundice in patients with
sensitivities and specificities of approximately 70%. Their predictions varied
from the measured value on average by 6.0 +/- 4.6% for serum hematocrit, 1.3 +
1.1 degrees F for rectal temperature, and 3.4 +/- 5.3 mg/dL for serum bilirubin.
Observer accuracy decreased when evaluating patients with high and low measured
values. CONCLUSIONS: The ability to correctly perform and interpret the physical
examination appears to be independent of the observer level of training, patient
ethnicity, or patient gender. The examination for pallor, warmth, and jaundice is
unreliable in predicting the corresponding laboratory or electronic measurement.
Certain anemic, febrile, or jaundiced patients may not be reliably detected
solely by a focused physical examination.
PMID- 10691075
TI - The focused abdominal sonography for trauma (FAST) examination: considerations
and recommendations for training physicians in the use of a new clinical tool.
AB - Focused abdominal sonography for trauma (FAST) is being used by growing numbers
of emergency physicians and surgeons because it has proven to be an accurate,
rapid, and repeatable bedside test for evaluating abdominal trauma victims.
Controversy exists about the optimal means of FAST education and the number of
examinations necessary to demonstrate competency. Most FAST educators agree that
FAST education should consist of three phases: didactic, practical, and
experiential. This article summarizes options and preliminary recommendations
suitable for developing a FAST curriculum.
PMID- 10691076
TI - Clinicopathological conference: multisystem failure in a child.
PMID- 10691077
TI - Do emergency medical services dispatch nature and severity codes agree with
paramedic field findings?
AB - Emergency medical services (EMS) systems increasingly seek to triage patients to
alternative EMS resources. Emergency medical services dispatchers may be asked to
perform this triage. New protocols may be necessary. Alternatively, existing
protocols may be sufficient for this task. For an existing dispatch protocol to
be sufficient, it at least must accurately categorize patient condition and
severity based on an external standard. OBJECTIVE: To examine the extent to which
nature codes (NCs), or patient condition codes, and severity codes (SCs)
currently assigned in one urban 911 center agree with paramedic field findings.
The null hypothesis was that there is no routine agreement (75%) between
dispatcher-assigned NC or SC and paramedic-assigned NC or SC for the same patient
using the same protocol. METHODS: Emergency medical services dispatch nature and
severity code data and matching out-of-hospital data were prospectively gathered
over six months. Dispatch data included the NC: caller-identified problem, and
the SC: dispatcher-assessed severity. Each NC is modified by one of three SCs (1,
3, or 9): 1 is emergent, 3 is urgent, and 9 is neither. Paramedics verified
and/or corrected dispatcher-assigned NCs and SCs using the same dispatch
protocol. RESULTS: One thousand forty usable cases fell into 33 unique NC/SC
combinations. The designation of SC 1 was assigned 275 times, SC 3 was assigned
736 times, and SC 9 was assigned 24 times. The SC was missing five times. The
overall NC agreement was 0.70 (95% CI = 0.697 to 0.703). The overall SC agreement
was 0.65 (95% CI = 0.645 to 0.655). The NC agreement exceeded 75% for ten (59%)
NC/SC combinations. The SC agreement exceeded 75% for five (29%) NC/SC
combinations. There was both NC and SC agreement for four (24%) combinations:
urgent breathing problems, urgent diabetic problems, urgent falls, and urgent
overdoses. The greatest NC/SC disagreement occurred within emergent and urgent
traffic crashes. Paramedics adjusted SC toward lower severity 29% of the time and
toward higher severity 5.4% of the time. There was no upward SC adjustment for
eight (47%) combinations. CONCLUSIONS: Certain dispatcher-assigned NC and SC
codes and NC/SC combinations achieved the study threshold. Overall agreement
failed to achieve the threshold. The lowest SC level was rarely assigned,
preventing a meaningful analysis of all severity levels.
PMID- 10691078
TI - Rattlesnake venom-induced thrombocytopenia response to Antivenin (Crotalidae)
Polyvalent: a case series.
AB - OBJECTIVE: To test the hypothesis that rattlesnake venom-induced thrombocytopenia
would improve following Antivenin (Crotalidae) Polyvalent administration, and
that the degree of platelet increase would correlate with the dosage of
antivenom. METHODS: The authors conducted a retrospective review of all patients
admitted for rattlesnake envenomation at two southern California hospitals
between 1980 and 1998. Patients were included if platelet count was less than 150
x 10(9)/L following a rattlesnake bite. Patients were excluded if they received
platelet transfusion. The relationship between Antivenin (Crotalidae) Polyvalent
administration and venom-induced thrombocytopenia was evaluated by linear
regression and paired t-test. RESULTS: The authors identified 103 cases of
rattlesnake envenomation. Seventeen cases met inclusion criteria for
thrombocytopenia. Two patients were excluded because they received platelet
transfusions. One additional patient was excluded from paired t-test only because
no antivenom was given. Thrombocytopenia usually improved between presentation
and discharge (mean difference, 44 x 10(9)/L), although complete resolution was
often not achieved. A statistically significant partial improvement in platelet
counts immediately after antivenom administration was observed in a subset of
patients with severe thrombocytopenia (platelet count <100 x 10(9)/L) (mean
difference, 64 x 10(9)/L). Using regression analysis, the authors did not detect
a linear relationship between the amount of Antivenin (Crotalidae) Polyvalent
administered and the degree of improvement. CONCLUSIONS: Although rattlesnake
venom-induced thrombocytopenia usually improves immediately after Antivenin
(Crotalidae) Polyvalent administration and by the time of discharge, the degree
of improvement is frequently incomplete and of uncertain clinical significance in
the absence of life-threatening bleeding. The authors found no correlation
between the degree of improvement and the dosage of Antivenin (Crotalidae)
Polyvalent.
PMID- 10691079
TI - Whose turf is it, anyway? Diagnostic ultrasonography in the emergency department.
PMID- 10691080
TI - Outcomes research and emergency medical services: the time has come.
PMID- 10691081
TI - The clinicopathological conference.
PMID- 10691082
TI - Research fundamentals: statistical considerations in research design: a simple
person's approach.
AB - A basic understanding of statistical methodology is essential, both for designing
quality research projects and for evaluating the medical literature. Careful
statistical planning, including the selection of study endpoints, the
determination of the required sample size, and the selection of statistical tests
to be used in the data analysis, is important to ensure a successful research
project. The purpose of this article is to provide a basic review of statistical
terms and methods for both the researcher and the clinician, as well as to
clarify questions that need to be answered prior to embarking on an experimental
study. The advantages of collaborating with statistical consultants, and some
guidelines for such collaborations, are discussed as well.
PMID- 10691083
TI - Gestational outcome in patients with first-trimester pregnancy complications and
ultrasound-confirmed live intrauterine pregnancy.
PMID- 10691084
TI - A truly emergent problem: button battery in the nose.
PMID- 10691085
TI - Radial head subluxation.
PMID- 10691086
TI - Resident self-scheduling: a painful method of reinventing the wheel.
PMID- 10691087
TI - Pneumocystis carinii infection in young non-immunosuppressed rabbits. Kinetics of
infection and of the primary specific immune response.
AB - The aim of this study was to determine the kinetics, the dissemination of the
infection and the immunological response to Pneumocystis carinii primary
infection in a non-immunosuppressed rabbit model. For this purpose, we developed
a nested PCR that amplified a portion of the mitochondrial large-subunit rRNA
gene of rabbit-derived P. carinii. The PCR detected P. carinii DNA in lung and
bronchoalveolar lavage fluids from 14- to 45-day-old rabbits but not in their
serum. No P. carinii DNA was detected in extrapulmonary organs from 28-day-old
rabbits with P. carinii pneumonia. ELISA and immunoblotting analysis showed that
5-day-old pups had elevated specific IgG. The IgG concentration sharply
decreased, reaching a trough on day 21, and from then onwards progressively
increased as the infection cleared. Conversely, the specific IgM concentration
increased during the infection and peaked on day 28. IgG mainly recognized a 50
kDa subunit of P. carinii organisms; IgM recognized first a 45-kDa subunit on day
21, whereas from day 28 onwards it also recognized the 50-kDa subunit. A P.
carinii-specific splenocyte proliferative response was observed on day 45. These
findings suggest that P. carinii primary infection is a time-limited and a lung
limited event and contribute new information on the relationship between the
kinetics of primary P. carinii infection and the immunological response in a
model that mimics the primary infections in humans.
PMID- 10691088
TI - The role of tumor necrosis factor (TNF)-alpha in the antitumor effect of
intrapleural injection of Lactobacillus casei strain Shirota in mice.
AB - The involvement of several cytokines in the antitumor effect induced by
intrapleural (i.pl.) injection of heat-killed cells of Lactobacillus casei strain
Shirota (LC 9018) in mice was investigated. Injection of LC 9018 i.pl. into Meth
A fibrosarcoma (Meth A)-bearing mice not only significantly prolonged the
survival of the mice, but also effectively inhibited the accumulation of
malignant pleural fluid in the thoracic cavity. In the thoracic cavity of tumor
bearing mice treated with LC 9018, we observed large amounts of several cytokines
including interleukin (IL)-1beta, interferon (IFN)-gamma, IL-12 and tumor
necrosis factor (TNF)-alpha. Both anti-IFN-gamma and anti-IL-12 monoclonal
antibody (mAb) treatments partially diminished the antitumor activity of LC 9018
in vivo, while the treatment of anti-IL-1beta mAb did not influence the survival
of the mice. However, anti-TNF-alpha mAb treatment completely abolished the
antitumor effect of LC 9018 in vivo, suggesting that in this model LC 9018 has a
survival-prolonging effect involving certain cytokines. Moreover, i.pl. injection
of mouse recombinant TNF-alpha into Meth A-bearing mice pretreated with anti-TNF
alpha mAb partially restored the survival-enhancing effect of LC 9018. These
results led us to conclude that TNF-alpha induced by i.pl. injection of LC 9018
plays an important role in the antitumor effect of LC 9018 in vivo.
PMID- 10691089
TI - Rat dorsal root ganglia neurons as a model for Listeria monocytogenes infections
in culture.
AB - Neurotropism of Listeria monocytogenes was studied in rat dorsal root ganglia
(DRG) and hippocampal neurons in culture. Using a system in which the DRG neurons
can grow relatively free from other cells, it was observed that such DRG neurons,
in contrast to hippocampal neurons, can be effectively infected by L.
monocytogenes. The bacteria aligned along DRG axons, but not along hippocampal
neurites. A mutant deficient in internalin, a protein required for entry into E
cadherin-expressing cells, did not interact with DRG neurons. Axonal migration of
bacteria was studied in the DRG neurons grown in a double-chamber system, where
either the neurites or the nerve cell bodies were exposed to the bacteria. The
data suggest that L. monocytogenes can infect both axons and DRG nerve cell
bodies, and that the bacteria can migrate in a retrograde as well as anterograde
direction. These results support the notion that L. monocytogenes can spread via
primary sensory neurons to the central nervous system. Infection of DRG primary
sensory neurons, as employed in the present study, provides a model for analysis
of bacterial and neuronal factors of importance for neurovirulence of L.
monocytogenes.
PMID- 10691090
TI - A membrane-located glycosphingolipid of monocyte/granulocyte lineage cells
induces growth arrest and triggers the lytic viral cycle in Epstein-Barr virus
genome-positive Burkitt lymphoma lines.
AB - Gangliosides are known to influence cell growth and differentiation. The neolacto
series ganglioside IV3NeuAc-nLc4 (2-->3-sialosylparagloboside) is present in
members of the monocyte/granulocyte lineage, but is not found in cells that
belong to the lymphocyte lineage. In this study we demonstrated that IV3NeuAc
nLc4 inhibits the proliferation of Epstein-Barr virus (EBV) genome-positive
Burkitt lymphoma cells of the lines Raji and P3HR-1K. IV3NeuAc-nLc4-induced
growth inhibition is associated with an increase in G0/G1 phase cells and a
reduced expression of CD21 and HLA-DR antigens on Raji cells. These data suggest
that IV3NeuAc-nLc4 may affect differentiation of lymphoma cells. Additionally,
the increased expression of viral mRNA species which are characteristic for the
lytic viral cycle in the non-producer line Raji and the enhanced release of
virions from the producer line P3HR-1K demonstrate that IV3NeuAc-nLc4 activates
the replication of EBV. Growth inhibition and termination of the viral latency
suggest that IV3NeuAc-nLc4 present in monocyte/granulocyte lineage cells may be
an effector of the natural defense against EBV persistency and transformation.
PMID- 10691091
TI - The ferric uptake regulator (Fur) homologue of Helicobacter pylori: functional
analysis of the coding gene and controlled production of the recombinant protein
in Escherichia coli.
AB - A homologue of the ferric uptake regulator protein Fur has recently been
identified within the Helicobacter pylori genome. The promoterless gene on a
plasmid did partially complement a fur-negative mutant of Escherichia coli, and
was strongly positive in the Fur titration assay (FURTA). The genetic and
functional characterization of the complete fur homologue performed in this study
revealed that the gene is conserved among H. pylori strains ( > 95% identity),
and does not carry nucleotide transitions in iron-resistant mutants of H. pylori.
The fur homologue on a plasmid mediated full iron-dependent ferric uptake
regulator activity in the fur-deficient mutant strains H1681 and H1780 of E.
coli. Immunoblot analysis revealed that Fur from H. pylori cross-reacts with
antibodies raised against Fur from E. coli. The fact that inactivation of the fur
gene abolished the FURTA-positive phenotype in the E. coli indicator strain
H1717, indicated that this phenotype is rather caused by the encoded protein than
by real Fur titration. Subcloning of the fur gene into an expression vector
allowed controlled production in E. coli, and purification of a recombinant
version of the H. pylori Fur protein. In summary, the results confirm the
function of the H. pylori Fur homologue as iron-dependent transcriptional
repressor by its ability to interact with the Fur-regulated promoters of the
genes fiu and fhuF in E. coli.
PMID- 10691092
TI - Influence of the genetic background on the pattern of lesions developed by
resistant and susceptible mice infected with Paracoccidioides brasiliensis.
AB - To compare the sequential evolution of lesions developed by resistant (A/Sn) and
susceptible (B10.A) mice to Paracoccidioides brasiliensis infection we inoculated
a virulent isolate of the fungus and collected the pancreas/peripancreatic
omentum monthly (from 1 to 6 months) post infection. After fixation, tissue
sections were stained by conventional methods for light microscopy to investigate
the cellular composition, the extracellular matrix (ECM) patterns and the
morphology of the yeasts in the lesions. In both strains, the fungal lesions were
localized mostly in the omentum; a few lesions in the pancreatic parenchyma were
observed, mostly in B10.A mice. In both strains, macrophages and plasmocytes were
the predominant cells in all lesions, followed by neutrophils (PMN) and
macrophages transformed into giant and epithelioid cells. Remarkable differences
were observed between resistant and susceptible mice, specially related to the
ECM structure of the granulomatous lesions. In A/Sn mice, from the 1st month on,
the coexistence of two types of lesions was observed: one type showed a well
defined encapsulated nodule, constituted mainly of type I collagen. Neutrophils
were abundant in areas of massive fungal destruction and few viable yeasts were
observed. The other type showed residual characteristics, with sparse collagen
deposits and presence of xantomatous-like macrophages, containing degenerated
fungi. Such residual lesions predominated after the 2nd month and were the only
type observed from the 4th month on, indicating the control of the infection. In
B10.A mice, on the contrary, only one type of lesion was observed, showing less
tendency to encapsulation and the formation of multiple small granulomatous foci,
individualized by reticular type III collagen fibers. There were many plasmocytes
in the periphery and large numbers of budding yeasts, with no evidence of fungal
destruction. In the course of the infection the lesions progressively increased
in number and size. Altogether, the comparative histopathological analysis
demonstrates the influence of the genetic pattern of the host on the lesions
developed by resistant and susceptible mice to P. brasiliensis infection.
PMID- 10691093
TI - Hantavirus Dobrava infection with pulmonary manifestation.
AB - Dobrava virus infection was diagnosed serologically by enzyme-linked
immunosorbent and immunofluorescence assays. To determine which hantavirus
serotype was involved, sera were analyzed by a focus reduction neutralization
test. The clinical data indicated that only pulmonary manifestation was present.
Our data support the presence of Dobrava virus infection outside the Balkan
region. In conclusion, a previously healthy adult with unexplained pulmonary
perfusion failure should be investigated for hantavirus infection.
PMID- 10691094
TI - Soluble fibrin species in arterial thrombi.
AB - The aim of this study was to characterize soluble fibrin(ogen) species in human,
arterial, in-vivo-formed thrombi, using the immunoblotting technique. Specimens
were collected via intra-arterial catheters in six patients scheduled for
catheter-directed thrombolysis. Unreduced and reduced samples of the supernatants
from the arterial thrombi-derived specimens were electrophoresed on
polyacrylamide gels and immunoblotted, using specific mono- and polyclonal anti
fibrin(ogen) antibodies. The reduced samples disclosed substantial amounts of
high molecular weight material, consistent with alpha-chain polymers and
gammagamma-dimers, as well as lower molecular weight material, such as alpha-,
beta- and gamma-chains. No fibrinogen with intact fibrinopeptide A was
detectable, and des-AABB fibrin represented a major fibrin derivative in the
soluble part of the arterial thrombi. The alpha-chains were C-terminally
degraded, most of them distal to position 259. In conclusion, we have
demonstrated the presence of cross-linked fibrin derivatives in soluble, arterial
thrombus-related material, without signs of fibrinogen-fibrin hybrids. The fibrin
derivatives were C-terminally degraded, thus representing X-oligomeric material,
most probably originating from plasmin degradation of insoluble thrombus fibrin.
The present study supports the hypothesis of a dynamic equilibrium between
clotting and lysis in thrombi.
PMID- 10691095
TI - Absorption and antithrombotic activity of unfractioned heparin after
intraduodenal administration in rats.
AB - In the search for a more acceptable route of heparin administration that can also
be used for long-term treatment, we evaluated the bioavailability and
antithrombotic activity of intraduodenal administration of unfractioned heparin
(UFH) in rats. A radioiodinate derivative of UFH was administered intraduodenally
in rats in conjunction with unlabeled UFH. We found that radioactivity increases
very rapidly in plasma, as well as on the surface of aortic and caval segments,
so that peak radioactivity was already achieved within 5 min of drug
administration. Subsequently, plasma radioactivity declined rapidly, although 1.5
2.5% of the total radioactivity administered was still circulating 3 h after drug
administration. The plasma anti-Xa activity was much lower and longer lasting
than expected from the radioactivity counts in both peripheral and portal blood,
and its level was very similar in the two circulatory districts, never exceeding
023 U/ml. This suggests that extensive degradation of the drug already occurs
during its gastrointestinal absorption. Nevertheless, in a stasis-induced venous
thrombosis model, intraduodenal UFH prevented thrombus formation in a dose
dependent way (ED50, 2000 IU/kg). The maximum antithrombotic effect was observed
when the drug was administered 30-60 min before ligature of the vena cava, and a
40% reduction of thrombus weight was still present at 180 min. Since
antithrombotic kinetics does not match the kinetics of either the plasma or
vessel-bound radioactivity but approaches what is found in anti-Xa activity, the
antithrombotic activity of oral heparin may be dependent on the release of
unlabeled endogenous glycosaminoglycans deposited in the vessels.
PMID- 10691096
TI - Characterization of immortalized human umbilical and iliac vein endothelial cell
lines after transfection with SV40 large T-antigen.
AB - Most in vitro studies of human endothelial cells have relied on cells derived
from human umbilical veins (HUVEC); however, heterogeneity of primary cultured
endothelial cells can make critical interpretation of results difficult. Several
endothelial cell lines have been produced to serve as a more constant source of
endothelial cells. In this study, we characterized the endothelial cell lines
EVLB3 and EVLC2 derived from HUVEC, and EVLK1 and EVLK2 derived from human iliac
vein endothelial cells (HIVEC). These cell lines maintained the typical
endothelial cell cobblestone morphology and appeared to be growth factor
independent. They lost PECAM-1 and von Willebrand factor, GP96 was reduced to the
level of vascular smooth muscle cells (SMC), but aSMC-actin was far less than in
vascular SMC. Antigen levels of tissue-type plasminogen activator (tPA) and
plasminogen activator inhibitor (PAI-1) were comparable with young endothelial
cells, and mRNA was present for tPA, PAI-1, tissue factor (TF), tissue factor
pathway inhibitor and thrombomodulin. This study revealed that mRNA and protein
expression of coagulation and fibrinolytic factors was influenced by the stage of
cell confluence. No differences could be detected between the endothelial cell
lines derived from HUVEC and HIVEC. These cell lines may be a useful tool for
studies on cellular interactions of fibrinolytic components or exploring the
regulation of TF expression.
PMID- 10691097
TI - Use of phage display for the generation of human antibodies that neutralize
factor IXa function.
AB - The use of libraries of phage-displayed human single-chain antibody fragments
(scFv) has become a new, powerful tool in rapidly obtaining therapeutically
useful antibodies. Here, we describe the generation of human scFv and F(ab')2
directed against the gamma-carboxyglutamic acid (Gla) domain of coagulation
factor IX. A large library of human scFv, displayed either on M13 phage or
expressed as soluble proteins, was screened for binding to human Gla-domain
peptide (Tyr1-Lys43). Among a panel of scFv that bound to the factor IX-Gla
domain, six scFv clones recognized full-length factor IX and exhibited strong
inhibitory activity of factor IX in vitro. After reformatting as F(ab')2, the
affinity for factor IX of three selected clones was determined: 10C12 Kd = 1.6
nmol/l, 13D1 Kd = 2.9 nmol/l, and 13H6 Kd = 0.46 nmol/l. The antibodies
specifically bound to factor IX and not to other coagulation factors, as assessed
by enzyme-linked immunosorbent-type and human plasma clotting assays. The
complementarity determining region amino acid sequences of clones 10C12 and 13D1
only differed at a single residue, whereas 13H6 showed little homology,
suggesting that 13H6 binds to a different epitope within the factor IX-Gla
domain. Despite the slightly lower affinity of 10C12 F(ab')2 versus 13H6 F(ab')2,
10C12 was consistently more potent than 13H6 in prolonging the activated partial
thromboplastin time (APTT), in inhibiting platelet-mediated plasma clotting, and
in inhibiting factor X activation by the intrinsic Xase complex. Finally, 10C12
F(ab')2 also recognized and neutralized factor IX/factor IXa of different
species, as demonstrated by the specific APTT prolongation of dog, mouse, baboon
and rabbit plasma. In summary, the results validate the usefulness of scFv phage
displayed libraries to rapidly generate fully human antibodies as potential new
therapeutics for thrombotic disorders.
PMID- 10691098
TI - Plasma fibrinogen, haemostatic factors and prediction of peripheral arterial
disease in the Edinburgh Artery Study.
AB - The role of fibrinogen and other haemostatic factors in prediction of peripheral
arterial disease (PAD) has not been established. We examined the associations of
plasma fibrinogen, von Willebrand Factor (vWF), tissue plasminogen activator (t
PA) antigen, fibrin D-dimer, and factor VII with the development and clinical
progression of PAD. In the Edinburgh Artery Study, 1592 men and women, aged
between 55 and 74 years, were followed prospectively over 5 years to detect the
onset of PAD, and the deterioration of established PAD. At baseline, 418
individuals had evidence of PAD and 60 (14.4%) subsequently deteriorated. 1080
subjects had no baseline disease, but 59 (5.5%) developed PAD during follow-up.
Median levels of fibrinogen and vWF were higher in the group developing disease
compared with the group which did not (2.78 g/l versus 2.57 g/l, P< or =0.01; 116
IU/dl versus 104 IU/dl, P< or =0.05; respectively). After adjusting for age and
sex, fibrinogen (P< or =0.01) and vWF (P< or =0.05) were significantly associated
with the risk of developing PAD. The association between fibrinogen and
development of disease remained after adjusting for cardiovascular risk factors
and baseline ischaemic heart disease (relative risk, 1.35, 95% confidence
interval, 1.05, 1.73; P< or =0.05). None of the haemostatic factors were
significantly associated with progression of PAD. In conclusion, plasma
fibrinogen levels are related to the future onset of PAD, providing further
evidence of a possible role of elevated fibrinogen in the development of
atherosclerotic disease.
PMID- 10691099
TI - Pharmacologic modulation of thrombin generation associated with human clots by
human purified antithrombin alone or in the presence of low molecular weight
heparin or unfractionated heparin.
AB - Procoagulant activities associated with human clots may contribute to thrombus
extension. We investigate the inhibition of clot-associated factor Xa and
thrombin activities by purified human antithrombin either alone or as combination
with a low molecular weight heparin (enoxaparin) as compared with unfractionated
heparin (UFH). The standard clots were prepared by recalcification of frozen
platelet-poor human plasma. Clot-associated thrombin was measured on the clot
after clot incubation in recalcified buffer or recalcified prothrombin solution.
The enzymatic reaction was measured using a specific substrate for thrombin (CBS
3447). The thrombin concentration was determined both on the clots and in the
reaction mixtures. In parallel, prothrombin fragment 1.2 and thrombin
antithrombin complexes (TAT) were measured using enzyme-linked immunosorbent
assay methods. We demonstrated that in the presence of purified human prothrombin
and antithrombin (AT), a partial inhibition of clot associated thrombin activity
correlated with an increase of TAT complexes. However, antithrombin was unable to
inhibit thrombin generation induced by the clot-associated factor Xa. Enoxaparin
(low molecular weight heparin) and UFH did not enhance clot-bound thrombin
inhibition induced by AT. We conclude that clot-bound thrombin is accessible to
human antithrombin alone. AT is also able to inhibit thrombin generated by factor
Xa-associated clot. However, neither a low molecular weight heparin or UFH
enhanced the effect of AT alone.
PMID- 10691100
TI - Platelet activation during angiotensin II infusion in healthy volunteers.
AB - The present study was undertaken to evaluate the effects of an intravenous
infusion of angiotensin II (10 ng/kg per min) on platelet function and
coagulation in vivo in 18 healthy males. The infusion increased mean arterial
pressure by 23+/-2 mm Hg. Plasma beta-thromboglobulin levels, reflecting platelet
secretion, increased by 66+/-24% during the infusion, as did also platelet
surface expression of P-selectin as measured by flow cytometry. Platelet
fibrinogen binding increased, whereas platelet aggregability, assessed by ex vivo
filtragometry, was unaltered. Angiotensin II caused mild activation of the
coagulation cascade with increases in plasma levels of thrombin-antithrombin
complex and prothrombin fragment F1 + 2. In conclusion, angiotensin II has mild
platelet-activating effects in vivo and also enhances coagulation. Markers of
platelet secretion are significantly increased, whereas markers of platelet
aggregability are less affected. The clinical relevance of these findings remains
to be clarified.
PMID- 10691101
TI - Plasma viscosity, fibrinogen and the metabolic syndrome: effect of obesity and
cardiorespiratory fitness.
AB - The association between both plasma viscosity and fibrinogen concentration with
clustering of metabolic risk markers was examined within a cross-sectional study
of employed middle-aged men. Analyses were performed on a subsample of 629 non
smokers (46.7+/-7.8 years) without diabetes. The effect of obesity and
cardiorespiratory fitness on these haemorheological parameters and their
association with the metabolic syndrome was also investigated. The cohort was
grouped by the number of metabolic markers present. Metabolic markers included
high-density lipoprotein-cholesterol (<1.13 mmol/l), triglycerides (> or =1.805
mmol/l), glucose (> or =5.5 mmol/l) and diastolic blood pressure (> or =90 mm
Hg). The age-adjusted odds ratio for hyperviscosity (> or =1.67 mPa/s) was 2.08
[95% confidence interval (CI), 1.06-4.05; P = 0.031] for the subjects with the
metabolic syndrome (three or more metabolic markers) when compared with those
with no metabolic abnormalities. The comparable age-adjusted odds ratio for
hyperfibrinogenaemia (> or = 3.47 g/l) was non-significantly higher at 1.69 (95%
CI, 0.87-3.27; P = 0.119). The mean age-adjusted plasma viscosity level and the
prevalence of hyperviscosity increased significantly from 1.629 to 1.692 mPa/s (P
= 0.0005) and from 21.0 to 36.0% with accumulating metabolic markers (P = 0.006).
Plasma viscosity and fibrinogen concentration both increased with higher
quartiles of skinfolds (P = 0.003 and P = 0.01, respectively) following
adjustment for age, lipids and leucocyte count. Plasma viscosity was also
significantly lower with higher levels of predicted maximum oxygen consumption
(VO2max) (P = 0.0005). The odds ratio for hyperviscosity in subjects with the
metabolic syndrome as compared with those with no metabolic markers was
attenuated following adjustment for age, sum of skinfolds and predicted maximum
oxygen consumption (VO2max) (1.44; 95% CI, 0.72-2.90; P = 0.307). These cross
sectional results suggest that plasma viscosity is associated with increased
clustering of metabolic markers in middle-aged men of high socio-economic status.
Obesity and poor cardiorespiratory fitness may be important in the development of
haemorheological abnormalities associated with the metabolic syndrome.
PMID- 10691102
TI - A kinetic model of the circulatory regulation of tissue plasminogen activator
during orthotopic liver transplantation.
AB - To better understand the regulation of tissue plasminogen activator (t-PA) and
plasminogen activator inhibitor 1 (PAI-1) during liver transplantation, we used a
computer model of the human circulatory system to simultaneously evaluate the
effect of t-PA secretion, t-PA inhibition by PAI-1, hepatic clearance of t-PA,
blood loss, transfusion and hemodynamics on t-PA and PAI-1 levels during liver
transplantation in three patients that differed in severity of liver disease,
blood loss and anhepatic changes in t-PA. Higher preoperative t-PA levels were
primarily related to underlying liver disease and reduced hepatic clearance.
During the anhepatic stage, when hepatic t-PA clearance was eliminated: (1) the
expected rise in t-PA was modulated by the extent of bleeding, which acted as an
alternate t-PA clearance mechanism; and (2) the ratio of t-PA:PAI-1 was increased
due both to lower t-PA clearance and reduced PAI-1 secretion. Recirculation of
the new liver was associated with renewed clearance of t-PA, an acute phase
increase in PAI-1 and a drop in the t-PA:PAI-1 ratio. Understanding fibrinolytic
regulation required simultaneous analysis of t-PA secretion, inhibition and
clearance. Anhepatic t-PA levels could be predicted based on preoperative liver
function and surgical blood loss, which acted as an alternate t-PA clearance
mechanism.
PMID- 10691103
TI - Mutations in a potential phospholipid binding loop in the C2 domain of factor V
affecting the assembly of the prothrombinase complex.
AB - Activated factor V (FVa) serves as a cofactor to activated factor X in the
prothrombinase complex. FVa is homologous to activated factor VIII (FVIIIa), the
light chains of both proteins being formed by similar domains (A3-C1-C2).
Interaction of FVa and FVIIIa with negatively charged phospholipid membranes is
crucial for the function of both cofactors. In both proteins, the C2 domains are
important for membrane binding but a detailed understanding of the binding
mechanisms is missing. Recently, knowledge has been gained into the three
dimensional structures of the C domains facilitating studies of structure
function relationships. Structural analysis of the C2 domain in FVa predicted a
surface-exposed loop (K2060, K2061, S2062, W2063, W2064) to be involved in
membrane binding. Three double mutants were created, K2060Q-K2061Q, W2063Y-W2064Y
and W2063A-W2064A, and expressed in a transient expression system. In addition, a
FV variant in which all four residues were mutated, K2060Q-K2061Q-W2063A-W2064A,
was produced. Mutagenesis of the two lysines showed no functional consequences,
whereas mutagenesis of the two tryptophanes yielded FVa with impaired ability to
interact with the phospholipid, as demonstrated by a poor functional activity at
limiting phospholipid concentrations. A molecular model of FVa, anchored at the
surface of a phospholipid membrane, was developed and used as a template for the
interpretation of the mutagenesis experiments.
PMID- 10691104
TI - Deep venous thrombosis prophylaxis in trauma: cost analysis.
AB - Deep vein thrombosis and pulmonary embolism are major risks in patients
experiencing major trauma. Currently, the American College of Chest Physicians
recommends low molecular weight heparin as prophylaxis in trauma patients with
identifiable risk factors in the absence of contraindications. Enoxaparin is the
only low molecular weight heparin available in the US that has been evaluated to
date in this indication. The purpose of this study was to perform incremental
cost-effectiveness ratio calculations for enoxaparin versus no prophylaxis as
thromboembolic prophylaxis in trauma patients. These calculations demonstrate
that a cost of $279.43 would be incurred for each thromboembolic event avoided if
enoxaparin 30 mg every 12 h were routinely used as prophylaxis in this
population, compared with no prophylaxis. Sensitivity analyses demonstrate that
if the incidence of proximal vein thrombosis in patients prophylaxed with
enoxaparin approached 1.8%, if the actual rate of these thrombi exceeded 19.4% in
untreated patients, or if the cost of the drug was decreased to $15.25 per dose,
a cost saving would be experienced in routine prophylaxis with this agent.
PMID- 10691105
TI - Right atrial and ventricular thrombi in Behcet's disease: a case report and
review of literature.
AB - Behcet's disease is a chronic multi-system disease presenting with recurrent oral
and genital ulceration, and relapsing uveitis. Cardiac involvement is an
extremely rare manifestation of this disorder. We report an unusual case of
Behcet's disease characterized by a mural cardiac thrombi in the right atrium and
right ventricle along with transient protein C and S deficiency.
PMID- 10691106
TI - Guinea pig platelets do not respond to GYPGKF, a protease-activated receptor-4
activating peptide: a property distinct from human platelets.
PMID- 10691107
TI - Felbamate in experimental model of status epilepticus.
AB - PURPOSE: To examine the putative seizure-protective properties of felbamate in an
animal model of self-sustaining status epilepticus (SSSE). METHODS: SSSE was
induced by 30-min stimulation of the perforant path (PPS) through permanently
implanted electrodes in free-running male adult Wistar rats. Felbamate (FBM; 50,
100, and 200 mg/kg), dizepam (DZP; 10 mg/kg), or phenytoin (PHT; 50 mg/kg) were
injected i.v. 10 min after SSSE induction. Electrographic manifestations of SSSE
and the severity of SSSE-induced neuronal injury were analyzed. RESULTS:
Felbamate injected during the early stages of SSSE (10 min after the end of PPS),
shortened the duration of seizures in a dose-dependent manner. Total time spent
in seizures after FBM and 290 +/- 251 min (50 mg/kg), 15.3 +/- 9 min (100 mg/kg),
and 7 +/- 1 min (200 mg/kg), whereas control animals spent 410 +/- 133 min
seizing. This effect of FBM was stronger than that of DZP (10 mg/kg, 95 +/- 22
min) and comparable to that of PHT (50 mg/kg, 6.3 +/- 2.5 min). In the applied
doses, FBM (200 mg/kg) was more effective than PHT (50 mg/kg) or DZP (10 mg/kg)
in shortening seizure duration and decreasing spike frequency, when administered
on the pleateau of SSSE (injection 40 min after the end of PPS). Anticonvulsant
action of FBM was confirmed by milder neuronal injury compared with control
animals. CONCLUSIONS: Felbamate, a clinically available AED with a moderate
affinity for the glycine site of the NMDA receptor, displayed a potent seizure
protective effect in an animal model of SSSE. These results suggest that FBM
might be useful when standard AEDs fail in the treatment of refractory cases of
SE.
PMID- 10691108
TI - Effects of vigabatrin on sleep-wakefulness cycle in amygdala-kindled rats.
AB - PURPOSE: Our aim was to study the effect of prolonged administration of
vigabatrin (VGB) on sleep-wakefulness cycle in kindled seizure-induced rats.
METHODS: Adult male Wistar rats were implanted stereotaxically with electrodes
for kindling and polysomnography. The rats were divided into two groups, kindled
and VGB-treated kindled rats. VGB was administered intraperitonially every day
for 21 days, and polysomnographic recordings were taken after doses 1, 7, 14, and
21. The drug effects were evaluated by comparing the records of kindled and drug
treated kindled rats. RESULTS: The VGB-administered kindled rats showed an
increase in total sleep time (TST) due to an increase in total non-rapid eye
movement (NREM) and light slow-wave sleep stage I (SI) with a decrease in
wakefulness. The number of episodes and REM onset latencies were found to be
decreased after drug treatment. CONCLUSIONS: It can therefore be concluded that
VGB has a somnolence-inducing effect and that it might mediate its anticonvulsant
effect by altering sleep architecture through sleep-regulating areas.
PMID- 10691109
TI - Evidence favoring genetic heterogeneity for febrile convulsions.
AB - PURPOSE: Two large Canadian kindreds appearing to segregate febrile convulsions
as an autosomal dominant trait were evaluated for linkage to three known FC loci,
as well as other epilepsy loci. METHODS: Members of the two families were
genotyped with microsatellite markers linked to the previously identified febrile
convulsion loci, FEB1, FEB2, and GEFS+, and we performed two-point linkage
analyses by assuming an autosomal dominant mode of inheritance. RESULTS: We
report the exclusion of the FC trait in our families to FEB1 on 8q13-21 and to a
second febrile convulsion locus on 19p13. Furthermore, we also excluded the GEFS+
locus on 19q13.1 as the cause of febrile convulsions in both kindreds.
Microsatellite markers linked to juvenile myoclonic epilepsy (EJM1), benign
neonatal familial convulsions EBN1 and EBN2, autosomal dominant nocturnal frontal
lobe epilepsy (ADNFLE), idiopathic generalized epilepsy (EGI), progressive
myoclonic epilepsy of Unverricht-Lundborg (EPM1), and partial epilepsy with
auditory features (EPT), were also excluded as potential loci linked to the FC
trait in our families. CONCLUSIONS: These findings favor considerable genetic
heterogeneity for febrile convulsions.
PMID- 10691110
TI - Expression of 5alpha-reductase and 3alpha-hydroxisteroid oxidoreductase in the
hippocampus of patients with chronic temporal lobe epilepsy.
AB - PURPOSE: The hippocampus is one of the principal target areas for neurosteroidal
action, and the major neuroendocrine conversion of progesterone appears to be
5alpha-reduction and 3alpha-hydroxysteroid oxidoreduction, leading to the potent
neurosteroid 3alpha,5alpha-tetrahydroxyprogesterone. To investigate whether the
human hippocampus is equipped with the enzymes 5alpha-reductase and 3alpha
hydroxysteroid oxidoreductase (3alpha-HSOR), we studied the expression of 5alpha
reductase types 1 and 2 and 3alpha-HSOR types 1 and 2 in the resected hippocampi
of patients with medically intractable chronic temporal lobe epilepsy. METHODS:
We studied tissue specimens from the hippocampi of 13 women, 25 men, and four
children. Quantification of different mRNAs was achieved by competitive reverse
transcription-polymerase chain reaction (RT-PCR). RESULTS: 5Alpha-reductase 1
mRNA and 3alpha-HSOR 2 mRNA were expressed in hippocampi of children and adults,
whereas 5alpha-reductase 2 mRNA and 3alpha-HSOR 1 mRNA were not expressed.
Neither 5alpha-reductase 1 mRNA nor 3alpha-HSOR 2 mRNA concentrations in
hippocampal tissue showed any statistically significant differences between women
and men or between children and adults. CONCLUSIONS: This study demonstrates for
the first time mRNA expression of the type 1 isozyme of 5alpha-reductase and the
type 2 isozyme of 3alpha-HSOR in the human hippocampus. The finding that both
5alpha-reductase and 3alpha-HSOR are present in the hippocampus leads us to
assume the synthesis of neuroactive steroids in this human brain area.
PMID- 10691111
TI - The potential for vigabatrin-induced intramyelinic edema in humans.
AB - PURPOSE: Vigabatrin (Sabril, Hoechst Marion Roussel) is an antiepilepsy drug
(AED) presently marketed in 64 countries for the treatment of partial and
secondarily generalized seizures. Vigabatrin (VGB) is marketed in a subset of
these countries for the treatment of infantile spasms. Clinical experience in
humans has shown that VGB provides effective seizure control with a wide margin
of safety. However, animal toxicity studies raised concern when prolonged
administration of VGB was shown to induce intramyelinic edema (IME) in some
laboratory animal species. METHODS: Animal and human data were reviewed with
respect to the potential for VGB-induced IME. Surveillance of patients receiving
VGB in clinical trials or by prescription has been conducted for >15 years to
identify patients developing clinical abnormalities that might be IME related.
RESULTS: The histologic lesions of VGB-induced IME in animals are reliably
reproduced and correlate with changes in multimodality evoked potentials (EPs)
and magnetic resonance imaging (MRI). Numerous studies of the effects of VGB on
EP and MRI in epilepsy patients have demonstrated no clear-cut IME-related
changes in these modalities. Additionally, autopsy and surgical brain samples
from VGB-treated patients have been scrutinized for potential IME histopathology.
In an estimated 350,000 patient-years of VGB exposure (approximately 175,000
patients exposed for 2 years at an average dose of 2 g/day), no definite case of
VGB-induced IME has been identified. CONCLUSIONS: Comprehensive review of a
variety of sources of data failed to identify any definite case of IME in humans
treated with VGB.
PMID- 10691112
TI - Subacute electrical stimulation of the hippocampus blocks intractable temporal
lobe seizures and paroxysmal EEG activities.
AB - PURPOSE: To investigate the clinical, electroencephalographic (EEG), and
histopathologic effects of subacute electrical stimulation of the hippocampal
formation or gyrus (SAHCS) on 10 patients with intractable temporal lobe
seizures. METHODS: Bilateral, depth, hippocampal or unilateral, subdural,
basotemporal electrodes were implanted in all 10 patients for a topographic
diagnosis of the site and extent of the epileptic focus before a temporal
lobectomy. In all patients, antiepileptic drugs (AEDs) were discontinued from 48
to 72 h before a program of continuous SAHCS, which was performed for 2-3 weeks.
Stimulation parameters were biphasic Lilly wave pulses, 130/s in frequency, 450
micros in duration, and 200-400 microA in amplitude. The stimuli were delivered
23 of every 24 h for the 2-3-week SAHCS period. The effects of SAHCS on the
number of clinical seizures per day and the percentage of interictal EEG spikes
per 10-second samples of maximal paroxysmal activity at the epileptic focus were
determined daily during the 16 days of SAHCS. At the completion of this program,
patients underwent an en bloc temporal lobectomy, and the histopathologic effects
of SAHCS on the stimulated tissue were analyzed by means of light-microscopy
studies. RESULTS: In seven patients whose stimulation electrode contacts were
placed within the hippocampal formation or gyrus and who experienced no
interruption in the stimulation program, SAHCS abolished clinical seizures and
significantly decreased the number of interictal EEG spikes at the focus after 5
6 days. The most evident and fast responses were found by stimulating either the
anterior pes hippocampus close to the amygdala or the anterior parahippocampal
gyrus close to the entorhinal cortex. Other surface, hippocampal, and
basotemporal EEG signs predicted and accompanied this antiepileptic response.
These included an electropositive DC shift and monomorphic delta activity at the
medial hippocampal and parahippocampal regions, and a normalization of the
background EEG activity and signs of slow-wave sleep in surface. depth, and
subdural regions. In contrast, no evident antiepileptic responses or no responses
at all were found in three patients when stimulation was either interrupted or
when it was administered outside the hippocampus. Light microscopy analysis of
the stimulated hippocampal tissue showed histopathological abnormalities
attributable to the depth-electrode penetration damage or to the pial surface
reaction to the subdural, Silastic electrode plate. However, no evident
histopathological differences were found between the stimulated and nonstimulated
hippocampal tissue. CONCLUSIONS: SAHCS appears to be a safe procedure that can
suppress temporal lobe epileptogenesis with no additional damage to the
stimulated tissue.
PMID- 10691113
TI - The impact of a single seizure on health status and health care utilization.
AB - PURPOSE: To assess the health status of patients after a single seizure. METHODS:
We compared single-seizure patients (SS) with patients who had well-controlled
epilepsy (WC), and uncomplicated hypertension (HT). Patients were adults screened
from emergency and outpatient units of two urban teaching hospitals using
predefined criteria. The 83 patients (SS, 30; WC, 29; HT, 24) were interviewed by
phone about functional status (SF-36), comorbid illness, cause of illness, number
of visits to health providers, and drug side effects. RESULTS: No significant
differences were found among groups for health status, SF-36 domain, or
occurrence of drug side effects. SS patients had significantly lower scores on
vitality (p < 0.03) and a trend toward lower role physical function (p < 0.07)
compared with age-adjusted population norms. SS reported more visits to health
providers than WC or HT, and the number of visits remained high at interview 1
year later. Patient knowledge of the "reason" for the seizure was not associated
with health status or number of visits. CONCLUSIONS: Health status of patients
within 1 year of a single seizure is similar to that of patients with well
controlled epilepsy or hypertension, but SS patients have greater health care
utilization.
PMID- 10691114
TI - Moderators of the effect of preoperative emotional adjustment on postoperative
depression after surgery for temporal lobe epilepsy.
AB - PURPOSE: Other outcome measures besides seizure control must be considered when
assessing the benefit of epilepsy surgery. We investigated the effect of
preoperative psychosocial adjustment on postoperative depression in epilepsy
patients followed up prospectively for 2 years after temporal lobectomy. METHODS:
The Washington Psychosocial Seizure Inventory (WPSI) evaluated psychosocial
functioning; the Centre for Epidemiological Studies Depression Scale (CES-D)
measured depression. Both were completed at baseline and follow-up. RESULTS:
Follow-up occurred in 39 temporal lobectomy patients at 2 years after surgery.
Greatest improvement in depression scores was limited to patients with good
seizure outcomes (seizure free, or marked reduction in seizure frequency), and
seizure outcome was a significant predictor of postoperative depression. Despite
this, preoperative scores on the emotional adjustment scale of the WPSI were most
highly correlated with depression 2 years after surgery. To clarify this
relation, moderated hierarchic regression suggested that good preoperative
emotional adjustment (WPSI) was generally associated with less depression after
surgery. Moreover, poorer preoperative adjustment combined with older age,
generalized seizures, the finding of preoperative neurologic deficits, a family
history of psychiatric illness, and/or a family history of seizures was related
to higher depression scores 2 years after surgery. CONCLUSIONS: Depression after
temporal lobectomy is dependent on a complex interaction of variables and can
have a significant effect on indices of postoperative adjustment. The WPSI
emotional adjustment scale may help to predict which patients are likely to be
chronically depressed after surgery.
PMID- 10691115
TI - Induction of partial epileptic seizures by flumazenil.
AB - PURPOSE: This study addressed the efficacy of flumazenil (FMZ) to induce or
activate interictal or ictal epileptic discharges in patients with medically
intractable partial epilepsies. METHODS: Flumazenil, 1 mg, was injected
intravenously in 67 patients undergoing presurgical monitoring for epilepsy
surgery, 49 of whom had been treated with benzodiazepines (BZDs) before
flumazenil was given. Continuous video electroencephalogram (EEG) monitoring with
surface or intracranial electrodes was used to evaluate interictal EEG activity,
ictal discharges, and the occurrence and semiology of clinically manifest
epileptic seizures. RESULTS: Interictal epileptiform potentials did not change in
frequency or distribution after FMZ. In patients not pretreated with BZDs,
epileptic seizures could not be provoked. In eight of the 49 patients pretreated
with BZDs, epileptic seizures occurred within 30 min of FMZ application. Seizure
semiology and regional EEG onset were identical to seizures recorded without FMZ.
Patients operated on according to seizure-onset localization with FMZ had a >75%
reduction in seizure frequency or became seizure free. CONCLUSIONS: Seizure
induction by FMZ seems to be a valid method for evaluating seizure semiology and
localization of the seizure-onset zone during presurgical monitoring of patients
with medically intractable localization-related epilepsies.
PMID- 10691116
TI - Planned ictal FDG PET imaging for localization of extratemporal epileptic foci.
AB - PURPOSE: This work demonstrates the feasibility of planned ictal positron
emission tomography (PET) with [18F]fluoro-2-deoxy-glucose (FDG) for localization
of epileptic activity in patients with frequent partial seizures of extratemporal
origin. METHODS: Ictal PET imaging was performed in four patients (two men and
two women, ages 28-61) with continuous or very frequent (every 3-15 min) partial
seizures. All patients had abnormalities apparent on magnetic resonance (MR) or
computed tomographic (CT) imaging, two with extensive brain lesions that
precluded precise localization of the seizure focus with interictal PET or single
photon emission tomography (SPECT) imaging. RESULTS: Ictal PET imaging
demonstrated a restricted area of focal hypermetabolism concordant with surface
electroencephalographic (EEG) recording in all cases. The PET images were
registered to MR imaging data for further anatomic localization of hypermetabolic
regions in three cases. The ictal PET data were used to guide neurosurgical
intervention in one case. CONCLUSIONS: We conclude that planned ictal PET imaging
may be a useful and potentially superior approach to ictal SPECT for identifying
the epileptic focus in a selected group of patients with continuous or frequent
simple partial seizures.
PMID- 10691117
TI - Spindles-inducing mechanism modulates sleep activation of interictal epileptiform
discharges in the Landau-Kleffner syndrome.
AB - PURPOSE: Landau-Kleffner syndrome (LKS) is characterized by a marked increase of
interictal epileptiform discharges (IEDs) during sleep. During nonrapid eye
movement (NREM) sleep, neuronal membrane potential oscillations lead to the
appearance of spindles and delta waves in the surface EEG and might develop into
paroxysmal synchronization. Spectral analysis allows the quantitative description
of the dynamics of delta (slow-wave activity, SWA, 0.5-4.5 Hz) and sigma activity
(SA, 12.0-16.0 Hz) and can be used to assess the relation between SA, SWA, and
IEDs during sleep. METHODS: We performed six overnight continuous EEG
polysomnographic studies in three patients with LKS. The temporal series of SWA
and SA were obtained from a spike-free derivation lead. The IEDs count was
performed on the most active lead. Relations between sigma and SWA and time
series of IEDs were tested by means of correlation techniques after data
normalization. RESULTS: Our results revealed a significantly higher correlation
between IEDs and SA with respect to SWA in all the subjects, in total sleep time.
The same analysis limited to NREM sleep highlights the better correlation between
SA and IEDs. CONCLUSIONS: Our data suggest that neural mechanisms involved in the
generation of sleep spindles facilitate IEDs production in LKS.
PMID- 10691118
TI - Contralateral EEG slowing and amobarbital distribution in Wada test: an
intracarotid SPECT study.
AB - PURPOSE: To relate the occurrence of contralateral electroencephalogram slowing
(CES) to amobarbital distribution, we performed electroencephalogram (EEG)
monitoring and intracarotid single photon emission computed tomography (SPECT)
during an intracarotid amobarbital procedure (IAP). METHODS: IAP was performed on
22 patients with temporal lobe epilepsy. CES was defined as the occurrence of
significant EEG slowing on the contralateral hemisphere (>50% of the ipsilateral
hemisphere slowing) after amobarbital injection. To map the distribution of the
amobarbital, we injected a mixture of amobarbital and (99m)technetium
ethylcysteinate dimer (99mTc-ECD) into the internal carotid artery and performed
a brain SPECT 2 h later. In the SPECT images, regions of interest were determined
by ipsilateral and contralateral anterior cerebral artery territories (iACA,
cACA), ipsilateral and contralateral middle cerebral artery territories (iMCA,
cMCA), and ipsilateral and contralateral posterior cerebral artery territories
(iPCA, cPCA), as well as ipsilateral and contralateral anterior and posterior
mesial temporal regions (iAMT, cAMT, iPMT, cPMT). The perfusion of amobarbital
was interpreted visually in each region. RESULTS: Amobarbital was distributed in
the iMCA in all the patients; in the iACA in 20 (90.9%) patients; in the iAMT in
14 (63.5%); and in the iPCA and iPMT in only two (9.1%). CES was observed in 13
(59.1%) patients. Cross-perfusion of amobarbital in limited areas of the cACA
were observed in only four of 13 patients. Wada retention memory scores (WRMS)
showed no significant difference between the CES- (n = 9) and CES+ (n = 13)
groups. CONCLUSIONS: Amobarbital rarely perfused the iPCA territory and the iPMT
region and was rarely delivered to the contralateral hemisphere. The occurrence
of CES was not related to the cross-perfusion of amobarbital. CES appears to be
produced by a transient functional disconnection from the ipsilateral hemisphere.
PMID- 10691119
TI - Frequency of bitemporal independent interictal epileptiform discharges in
temporal lobe epilepsy.
AB - PURPOSE: Bitemporal interictal epileptiform discharges (IEDs) occur in < or =42%
of scalp EEGs in patients with temporal lobe epilepsy (TLE) studied with routine
EEGs or partial analysis of long-term recordings. METHODS: Twenty-eight patients
with TLE demonstrating exclusively unilateral temporal IEDs on routine EEGs
underwent 24-h continuous recording. The entire record was visually inspected for
epileptiform discharges. We used continuous EEG to assess the significance of
long-term recording in detecting bilateral IEDs. RESULTS: Twenty-two patients had
left temporal IEDs; 21 had right temporal IEDs. Seventeen (61%) patients had IEDs
originating from both the right and left temporal lobes. The probability of
detecting bilateral independent IEDs was correlated with the duration of
continuous EEG recording. There was no correlation between the number of IEDs
originating from one side and the probability of detecting independent IEDs on
the other side. The frequencies of IEDs were not correlated with the length of
time since onset of epilepsy. CONCLUSIONS: The findings suggest that when long
term recordings are performed, the incidence of bilateral discharges in TLE is
higher than previously reported in the literature and supports the view that TLE
is commonly a bilateral disease.
PMID- 10691120
TI - The value of early postictal EEG in children with complex febrile seizures.
AB - PURPOSE: To assess the usefulness of an early postictal EEG in neurologically
normal children with complex febrile seizures. METHODS: We conducted a
retrospective chart review of all neurologically normal children who were
hospitalized over a period of 2.5 years after complex febrile seizures, and had
an EEG up to 1 week after the seizure. RESULTS: Thirty-three patients (mean age,
17.8 months) qualified for inclusion into the study. Twenty-four patients were
qualified as complex cases based on one factor (prolonged in 9, repetitive in 13,
and focal in 2). Nine other patients had two complex factors: in six patients,
the seizures were long and repetitive; in two patients, the seizures were focal
and repetitive; and in one patient, the seizures were long, focal, and
repetitive. Thirteen (39%) patients experienced prior febrile seizures. All 33
patients had a normal postictal sleep EEG. Our results indicate with a 95%
probability that the true rate of abnormalities in an early postictal EEG
performed on otherwise normal children with complex febrile seizures is 8.6% or
less. CONCLUSIONS: The yield of abnormalities of an early postictal EEG in this
population is low and similar to the reported rate of abnormalities in children
with simple febrile seizures. The routine practice of obtaining an early EEG in
neurologically normal children with complex febrile seizures is not justified.
PMID- 10691121
TI - A multicenter randomized controlled trial on the clinical impact of therapeutic
drug monitoring in patients with newly diagnosed epilepsy. The Italian TDM Study
Group in Epilepsy.
AB - PURPOSE: To assess the clinical impact of monitoring serum concentrations of
antiepileptic drugs (AEDs) in patients with newly diagnosed epilepsy. METHODS:
One-hundred eighty patients with partial or idiopathic generalized nonabsence
epilepsy, aged 6 to 65 years, requiring initiation of treatment with
carbamazepine (CBZ), valproate (VPA), phenytoin (PHT), phenobarbital (PB), or
primidone (PRM) were randomly allocated to two groups according to an open,
prospective parallel-group design. In one group, dosage was adjusted to achieve
serum AED concentration within a target range (10-20 microg/ml for PHT, 15-40
microg/ml for PB, 4-11 microg/ml for CBZ, and 40-100 microg/ml for VPA), whereas
in the other group, dosage was adjusted on clinical grounds. Patients were
followed up for 24 months or until a change in therapeutic strategy was
clinically indicated. RESULTS: Baseline characteristics did not differ between
the two groups. Most patients with partial epilepsy were treated with CBZ,
whereas generalized epilepsies were most commonly managed with PB or VPA. PHT was
used only in a small minority of patients. A total of 116 patients completed 2
year follow-up, and there were no differences in exit rate from any cause between
the monitored group and the control group. The proportion of assessable patients
with mean serum drug levels outside the target range (mostly below range) during
the first 6 months of the study was 8% in the monitored group compared with 25%
in the control group (p < 0.01). There were no significant differences between
the monitored group and the control group with respect to patients achieving 12
month remission (60% vs. 61%), patients remaining seizure free since initiation
of treatment (38% vs. 41%), and time to first seizure or 12-month remission.
Frequency of adverse effects was almost identical in the two groups. CONCLUSIONS:
Only a small minority of patients were treated with PHT, the drug for which serum
concentration measurements are most likely to be useful. With the AEDs most
commonly used in this study, early implementation of serum AED level monitoring
did not improve overall therapeutic outcome. and the majority of patients could
be satisfactorily treated by adjusting dose on clinical grounds. Monitoring the
serum levels of these drugs in selected patients and in special situations is
likely to be more rewarding than routine measurements in a large clinic
population.
PMID- 10691122
TI - Remote memory in epilepsy.
AB - PURPOSE: There is now a considerable amount of research relating to memory
functioning in epilepsy. The majority of studies have focused on the retention of
new information, and few reports have measured memory for past events. This study
aims to redress this and measure the efficiency of remote memory in epilepsy.
METHODS: A remote memory questionnaire was prepared and administered to three
groups of patients with epilepsy and a control group without epilepsy. The
questionnaire assessed knowledge of public events that occurred between 1980 and
1991, inclusive. The epilepsy groups comprised 33 patients with temporal lobe
epilepsy (TLE), 33 with extratemporal epilepsy (ExTE), and 10 with primary
generalized epilepsy (PGE). Thirty control subjects were tested. RESULTS:
Patients with TLE performed significantly less well on the questionnaire than all
other groups (p = 0.001), but no effect of laterality was recorded; patients with
extratemporal or primary generalised epilepsy did not differ from controls.
Performance on the questionnaire was not determined by verbal IQ, educational
achievement, social class, or drug treatment, but was related to the number of
generalised convulsions that had occurred since 1980. The strongest
neuropsychological predictors of performance on this questionnaire were measures
of verbal memory. CONCLUSIONS: The study demonstrated weak memory for past events
in patients with TLE, thereby providing evidence of a broader memory disturbance
in this group than has been previously highlighted. A test of remote memory, such
as the one designed for this study, is easy to administer and provides clinically
important information not available from conventional neuropsychological tests.
PMID- 10691123
TI - Slow-frequency repetitive transcranial magnetic stimulation in a patient with
focal cortical dysplasia.
AB - PURPOSE: To evaluate the effect of slow-frequency repetitive transcranial
magnetic stimulation (SF-rTMS) on interictal epileptiform activity and seizure
frequency in a patient with medically refractory partial seizures due to focal
cortical dysplasia. METHODS: A 9-cm circular coil was positioned over the area of
cortical dysplasia. One hundred stimuli given at 0.5 Hz at 5% below motor
threshold were given biweekly for four consecutive weeks. The EEG was recorded
for 30 min before and after the first 100 stimuli. The number of seizures during
the month of stimulation was compared with that of the month before stimulation.
RESULTS: Stimulation was associated with a 70% reduction in the frequency of
seizures and a 77% reduction in the frequency of interictal spikes. No seizures
occurred during stimulation. CONCLUSIONS: SF-rTMS was safe and well tolerated in
this patient. The reduction in seizures and interictal spikes associated with SF
rTMS supports the concept of SF-rTMS-induced cortical inhibition.
PMID- 10691124
TI - Seizures provoked by blows to the head.
AB - The nonepileptic nature of convulsions occurring within seconds of head injury
has been commented on. However, we have recently seen a patient in whom
relatively trivial blows to the head did seem to give rise to epileptic seizures.
PMID- 10691125
TI - Can early postnatal closed head injury induce cortical dysplasia.
AB - PURPOSE: Increased availability of surgically resected epileptogenic tissues
reveals often unsuspected cortical dysplasia (CD). There is some controversy
about the ontogenic stages in which these occur. Although most take place during
neuroblast proliferation and migration, there is some evidence for some CD
occurring during postmigrational intrinsic cortical organization. It has been
shown that various kinds of focal cortical manipulations in rats, if performed
within 3-4 postnatal days, lead to the genesis of various cortical malformations
including a four-layered microgyrus or an unlayered CD. It is not known whether
such events also might occur in the human brain. METHODS: Two children sustained
minor head trauma within 4 postnatal days and later developed intractable
epilepsy, which was relieved by surgery. Neuropathologic analysis of the resected
tissues revealed an unsuspected microdysplastic cortex immediately adjacent to a
focal, modest meningeal fibrosis, presumably secondary to the old closed head
trauma. RESULTS: The main histologic features were a disorganized, unlayered
cortex; abnormal clusters of neurons, often with complex, randomly oriented
proximal dendritic patterns with absent apical orientation; the presence of a
number of heterotopic small and large neurons in the white matter; absence of
inflammatory infiltrates, of hemosiderine, of reactive gliosis, or of an
excessive number of blood vessels. The morphologic features in these surgical
specimens suggest that these focal malformations occur because of a regional
disorder of postmigrational intrinsic cortical remodeling. CONCLUSIONS: The
clinical histories and the pathologic findings lend some support to the
hypothesis that minor morbid events occuring in the immediate postnatal period
may lead to microdysplasia in the human similar to those induced in rat pups. The
animal model could be helpful to clarify the genesis of some cases of CD and of
the epileptogenicity often manifesting later in life.
PMID- 10691126
TI - Hemicranial volume deficits in patients with temporal lobe epilepsy with and
without hippocampal sclerosis.
PMID- 10691127
TI - Hemicranial volume deficits in patients with temporal lobe epilepsy with and
without hippocampal sclerosis.
PMID- 10691128
TI - Chromosome of the enterohemorrhagic Escherichia coli O157:H7; comparative
analysis with K-12 MG1655 revealed the acquisition of a large amount of foreign
DNAs.
AB - A complete Xba I and Bln I cleavage map was constructed for the chromosome of an
enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain isolated from an
outbreak in Sakai City, Japan, in 1996. A comparative chromosome analysis with E.
coli K-12 strain MG1655 was made. The EHEC chromosome was approximately 5600 kb
in length, 1 Mb larger than that of MG1655. Despite the marked difference in
chromosome length, the location and direction of seven rRNA operons of the EHEC
strain were similar to those for MG1655. Overall organization of genes common in
both strains is also highly conserved. Chromosome expansion was observed
throughout the EHEC chromosome, albeit in an uneven manner. A large portion of
the chromosome enlargement was observed in the region surrounding the replication
terminus, particularly in a segment containing the terA locus. Sample sequencing
of 3627 random shotgun clones suggested the presence of approximately 1550 kb
strain-specific DNAs on the EHEC chromosome, most of which are likely to be of
foreign origin.
PMID- 10691129
TI - A large scale structural analysis of cDNAs in a unicellular green alga,
Chlamydomonas reinhardtii. I. Generation of 3433 non-redundant expressed sequence
tags.
AB - To understand genetic information carried in a unicellular green alga,
Chlamydomonas reinhardtii, normalized and size-selected cDNA libraries were
constructed from cells at photoautotrophic growth, and a total of 11,571 5'-end
sequence tags were established. These sequences were grouped into 3433
independent EST species. Similarity search against the public non-redundant
protein database indicated that 817 groups showed significant similarity to
registered sequences, of which 140 were of previously identified C. reinhardtii
genes, but the remaining 2616 species were novel sequences. The coverage of full
length protein coding regions was estimated to be over 60%. These cDNA clones and
EST sequence information will provide a powerful source for the future genome
wide functional analysis of uncharacterized genes.
PMID- 10691130
TI - Isolation and mapping of rFUS6, a rice orthologue of Arabidopsis thaliana FUS6.
AB - COP9 complex is one of the most important components that act in repressing
photomorphogenesis in Arabidopsis thaliana. FUS6 has been identified as one of
eight subunits of the COP9 complex in Arabidopsis. Using Arabidopsis Fus6 cDNA as
a probe, we screened a rice root cDNA library and a rice genomic library. A 1730
bp cDNA was obtained, which has an open reading frame corresponding to 441-amino
acid. This 441 amino acids putative protein has 67% identity with Arabidopsis
COP11/FUS6 (AtFUS6) and 40% identity with human GPS1, an AtFUS6 orthologue. So we
designated this novel gene as rFUS6. The 6.2-kb genomic sequence of rFUS6 was
also obtained. Sequence comparison showed that the rFUS6 gene had six exons and
five introns. Sequence inspection of the 5'-flanking region revealed the presence
of some potential light-regulated cis-elements such as a G-box, GT-1 binding
sites, and a TGACG motif. Southern hybridization with rice total DNA showed that
rFUS6 was perhaps a single copy gene. The rFUS6 locus was mapped by hybridization
with a rice BAC library membrane and the results showed that rFUS6 had a locus at
16.3 cM of chromosome 1.
PMID- 10691131
TI - Structural analysis and complete physical map of Arabidopsis thaliana chromosome
5 including centromeric and telomeric regions.
AB - Previously, we have reported a fine physical map of Arabidopsis thaliana
chromosome 5, except for the centromeric and telomeric regions, by ordering
clones from YAC, P1, TAC, and BAC libraries of the genome consisting of the two
contigs of upper arm and lower arm, 11.6 M bases and 14.2 M bases, respectively.
Here, the remaining centromeric and telomeric regions of chromosome 5 are
completely characterized by the ordering of clones and PCR amplifications.
Chromosome 5 of Arabidopsis thaliana ecotype Columbia is about 28.4 M bases long.
The centromeric region is estimated at about 2 M bases long between two 5S-rDNA
clusters. The 180-bp repeat region mainly consists of blocks of 180-bp tandem
family and various type retroelements dispersed over a 500-kb region. The
telomeric regions of chromosome 5 are characterized by PCR cloning, sequencing
and hybridization. The telomere repeats at both ends are about 2.5-kb long and
interestingly, telomere-associated repeats (approximately 700 bp) are found near
both ends of chromosome 5.
PMID- 10691132
TI - Sequence analysis of a total of three megabases of DNA in two regions of
chromosome 8p.
AB - Large-scale sequencing of genomic regions and in silico gene trapping together
represent a highly efficient and powerful approach for identifying novel genes.
We performed megabase-level sequence analyses of two genomic regions on human
chromosome 8p (8p11.2 and 8p22-->p21.3), after covering those segments with
sequence-ready contigs composed of 74 cosmids, 14 BACs, and three PAC clones. We
determined continuous nucleotide sequences of 1,856,753 bases on 8p11.2 and
1,210,381 bases on 8p22-->p21.3 by combining the shotgun and primer-walking
methods. In silico gene trapping identified four novel genes in the 8p11.2 region
and, in the 8p22-->p21.3 region, six known genes (PRLTS, PCM1, MTAMR7, HCAT2,
HFREP-1 and PHP) and three novel genes. The distribution of Alu and LINE1
repetitive elements and the densities of predicted exons were different in each
region, and Alu-rich portions contained more exonic sequences than LINE1-rich
areas.
PMID- 10691133
TI - Sequence-ready 1-Mb YAC, BAC and cosmid contigs covering the distal imprinted
region of mouse chromosome 7.
AB - We have constructed approximately 1-Mb contigs of yeast artificial chromosome
(YAC), bacterial artificial chromosome (BAC) and cosmid clones covering the
imprinted region in mouse chromosome band 7F4/F5. This region is syntenic to
human chromosome 11p15.5, which is associated with Beckwith-Wiedemann syndrome
(BWS) and certain childhood and adult tumors. These contigs provide the basis for
genomic sequencing, identification of genes and their regulatory elements, and
functional studies in transgenic and knockout mice, which should be of help to
understand not only the mechanisms of imprinting but also the molecular events
involved in the genesis of BWS and tumors.
PMID- 10691134
TI - A binary vector plasmid for gene expression in plant cells that is stably
maintained in Agrobacterium cells.
PMID- 10691135
TI - Computer-assisted three-dimensional surgical planning and simulation: 3D color
facial model generation.
AB - A scheme for texture mapping a 3D individualized color photo-realistic facial
model from real color portraits and CT data is described. First, 3D CT images
including both soft and hard tissues should be reconstructed from sequential CT
slices, using a surface rendering technique. Facial features are extracted from
3D soft tissue. A generic mesh is individualized by correspondence matching and
interpolation from those feature vertices. Three digitized color portraits with
the "third" dimension from reconstructed soft tissue are blended and texture
mapped onto the 3D head model (mesh). A color simulated human head generated from
frontal, right and left real color portraits can be viewed from an arbitrary
angle in an inexpensive and user-friendly conventional personal computer. This
scheme is the basic procedure in 3D computer-assisted simulation surgery.
PMID- 10691137
TI - Laser scanning of the ear identifying the shape and position in subjects with
normal facial symmetry.
AB - The objective of the present study was to discover if dimensional measurements of
the ear could be determined with a laser scanning technique and whether or not
the location of landmarks of the ear could be reliably measured with respect to
those on the midline of the face. Computer-generated images were created from
laser scans of 20 subjects. Dimensional measurements were made between landmarks
on the ear and face. Differences between repeated dimensional measurements of the
ear were very small, as were those measurements made between landmarks on the ear
to the midline of the face. Differences between dimensions of the left and right
ears were observed, but were of a small magnitude. The results suggest that the
dimensions of the ear and its position with respect to landmarks in the midline
of the face can be reliably measured on normal subjects and that laser scanning
is a useful technique for planning and monitoring facial reconstruction of the
ear.
PMID- 10691136
TI - Computer-assisted three-dimensional surgical planning and simulation: 3D virtual
osteotomy.
AB - A computer-assisted three-dimensional virtual osteotomy system for orthognathic
surgery (CAVOS) is presented. The virtual reality workbench is used for surgical
planning. The surgeon immerses in a virtual reality environment with stereo
eyewear, holds a virtual "scalpel" (3D Mouse) and operates on a "real" patient
(3D visualization) to obtain pre-surgical prediction (3D bony segment movements).
Virtual surgery on a computer-generated 3D head model is simulated and can be
visualized from any arbitrary viewing point in a personal computer system.
PMID- 10691138
TI - Three-layer closure of an oroantral-cutaneous defect.
AB - Reconstruction of oroantral defects, which are usually caused by tumor resection,
is challenging. These defects become an even more difficult problem when they
comprise multiple layers including oral mucosa, subcutaneous tissue, muscle and
skin. This paper describes such a case in which a three-layer closure using a
palatal flap, a buccal fat pad flap and a local skin flap was successfully
performed.
PMID- 10691139
TI - Tooth-borne distraction to widen the mandible. Technical note.
AB - Based on reported animal studies, the case report presented demonstrates the use
of tooth-borne distraction osteogenesis for mandibular widening of 1 cm in order
to avoid extraoral distraction devices. Detrimental side effects on healthy
anchoring teeth are not likely.
PMID- 10691140
TI - Traumatic optic neuropathy. A case report.
AB - A case of visual loss following cranio-maxillofacial trauma is reported. The
patient had a sudden partial blindness associated with a fracture of the roof,
medial and lateral orbital walls. Access to the orbit was achieved through a
transethmoidal approach using the Howarth-Lynch medial incision and resecting the
bone fragments which impinged on the optic nerve. The patient had total return of
visual acuity, without surgical complications. The role of orbital and optic
decompression in the management of patients with traumatic optic neuropathy is
discussed. Its indications are controversial and the procedure should be
considered only within the context of the specific needs of the individual
patient.
PMID- 10691141
TI - The role of vital tissue staining in the marginal control of oral squamous cell
carcinoma.
AB - Since vital staining has been advocated as a sensitive method of displaying
epithelial atypia, 14 oral squamous cell carcinomas were stained immediately
preoperatively with toluidine blue and then resected 1 cm outside clinically
abnormal or positively staining tissue. The integrity of the entire tissue margin
was histologically examined in each case. Whilst vital staining delineated all 14
invasive carcinomas at the centre of each resected specimen, 10 foci of carcinoma
in-situ or severe dysplasia were identified not to have stained at the resection
margins. Toluidine blue may, therefore, be an adjunct in identifying invasive
tumour at mucosal resection margins. However, it would appear to be of no benefit
in delineating positive resection margins due to carcinoma-in-situ or severe
dysplasia, and hence it may be of little value in reducing the incidence of local
recurrences.
PMID- 10691142
TI - Nuclear DNA content, an adjunct to p53 and Ki-67 as a marker of resistance to
radiation therapy in oral cavity and pharyngeal squamous cell carcinoma.
AB - Factors of prognosis and radioresistance in oral cavity and pharyngeal squamous
cell carcinoma (OCPSCC) are limited. In the present study, the usefulness of
tumor DNA content in predicting radioresistance in patients with OCPSCC has been
investigated. Radioresistance has been defined as local recurrence or tumor
persistence after radiation therapy. DNA-ploidy analysis was performed by static
cytometry on smears of cell suspensions obtained from formalin-fixed paraffin
embedded material and stained with Feulgen. DNA-ploidy was correlated with the
proliferation rate (Ki-67) and p53 protein accumulation obtained by
immunohistochemistry. The follow-up of patients ranged from 8 to 62 months.
Radioresistance was more common in non-diploid tumors; 14/28 (50%) non-diploid
tumors recurred, whereas only 3 (10.7%) out of 28 diploid tumors had local
failure (P=0.0019). Proliferation rate and p53 accumulation, evaluated by
immunohistochemistry, also added prognostic information. Twelve out of 14
failures were from non-diploid tumors with a low proliferation rate (Ki-67<20%),
whereas none of 20 p53-negative diploid tumors developed recurrences. This study
showed that non-diploid tumors responded poorly to radiotherapy. DNA content
appeared, therefore, as a significant prognostic marker for the evaluation of
OCPSCC in patients receiving radiation therapy. This study also showed that DNA
content adds information to p53 accumulation and the proliferation rate (Ki-67)
for the purposes of determining patient management.
PMID- 10691143
TI - Chromatic analysis of autofluorescence emitted from squamous cell carcinomas
arising in the oral cavity: a preliminary study.
AB - Chromatic analysis was carried out to characterize the color quality of
autofluorescence emitted from oral squamous cell carcinomas (SCC) and to
objectively compare autofluorescence among various tissues. The following
specimens were studied: 33 SCC, 3 epithelial dysplasias, 39 benign lesions, 31
dorsa of the tongue and 18 dental plaques. Autofluorescence depicted on
fluorescence photographs was measured with a chroma meter. Chromatic values of
autofluorescence differed significantly between SCC and non-cancerous tissues and
between different stages of SCC. Autofluorescence of SCC tended to shift from
orange to reddish orange with advancement of stage. These results suggest that
autofluorescence of oral SCC chromatically differs from that of other tissues and
depends on the stage of cancer.
PMID- 10691144
TI - Traumatic cervical cystic hygroma.
AB - An unusual case of traumatic cervical cystic lymphangioma in an adult man is
presented.
PMID- 10691145
TI - Diffuse chronic sclerosing osteomyelitis and the synovitis, acne, pustolosis,
hyperostosis, osteitis (SAPHO) syndrome in two sisters.
AB - Two sisters with diffuse chronic sclerosing osteomyelitis of the mandible and the
humerus and the synovitis, acne, pustolosis, hyperostosis and osteitis syndrome
(SAPHO syndrome) are presented. The diagnoses of diffuse chronic sclerosing
osteomyelitis at the age of 12 years and 27 years, respectively, were based on
typical medical history, clinical symptoms and radiographic, histologic and
scintigraphic findings. Because skin lesions and scintigraphic enhancement of the
sternoclavicular joints with hyperostosis were present, a SAPHO syndrome was
diagnosed in both sisters. Microbiological cultures of biopsy specimens revealed
coagulase-negative Staphylococcus aureus at the humerus and Haemophilus
parainfluenzae, Streptococcus, Actinomyces and Veilonella species at the
mandible. Repeated operative procedures, including decortications, resection and
reconstruction, and multiple histologic and microbiologic studies were performed
over a period of up to 20 years. Since HLA typing yielded identical gene loci, we
suggest that hereditary and autoimmune factors may play a role in the
pathogenesis of these cases.
PMID- 10691146
TI - Biomechanical and histological studies of particulate hydroxylapatite implanted
in femur bone defects of adult dogs.
AB - The purpose of this study was to investigate the biomechanical behavior and the
histology of particulate hydroxylapatite (HA) implanted in bone defects created
in femurs of 48 adult mongrel dogs. The bone defects, measuring 10 x 10 x 25 mm
with or without HA implantation, were allowed to heal until the end of the 1st,
2nd, 3rd, 6th, 9th and 12th months after surgery. The harvested tissue specimens
from the implant sites were processed into long cubic or rectangular prismatic
forms. Their mechanical strengths were assessed using compression and shearing
tests to measure the maximal compressive and shear stress by force loading on the
middle portions of the specimens. Histological sections of each stage were
processed with both decalcified and nondecalcified methods. The results showed
that the mechanical strength of the tested specimens was closely related to the
tissue regeneration within the bone defect. Progressive regeneration of new bone
was observed at each stage, with complete bone formation at the 9-month period. A
consistent increase in both maximal compressive stress and maximal shear stress
was noted at each stage, responsive to the ossification and maturation of the
regenerating tissue within the bone defect. This animal model provides a novel
approach to directly estimate the tissue strength of the HA-implanted bone
defect.
PMID- 10691147
TI - Osteoinduction by recombinant human bone morphogenetic protein-2 at
intramuscular, intermuscular, subcutaneous and intrafatty sites.
AB - To compare the osteoinductive activity of recombinant human bone morphogenetic
protein-2 (rhBMP-2) at various sites in rats, 5 microg of rhBMP-2 were implanted
into various sites, using atelopeptide type-I collagen (CL) as a carrier (BMP
groups). CL implantation was used as a control. Forty Wistar rats were divided
into intramuscular, intermuscular, subcutaneous and intrafatty site groups (IrM,
IeM, SC and IF, respectively). Bone formation was evaluated radiographically,
histologically and biochemically 21 days after implantation. In the BMP groups,
the alkaline phosphatase activity and calcium content at all sites were higher
than those in the control groups. Among the BMP groups, the new bone formation
was highest in the IrM and lowest in the IF radiographically, histologically and
biochemically. Five microg of rhBMP-2, a relatively low dose, induced adequate
new bone formation in all sites. The variations of osteoinductive activity of
rhBMP-2 in various sites may be due to differences in the blood supply.
PMID- 10691148
TI - An image-based approach for designing and manufacturing craniofacial scaffolds.
AB - Bone tissue engineering (BTE), which combines biomaterial scaffolds with
biologically active factors, holds tremendous promise for reconstructing
craniofacial defects. A significant challenge in craniofacial reconstructive BTE
applications is the complex patient-specific geometry that must be reconstructed.
In this paper, we present an image-based approach for designing and manufacturing
patient-specific craniofacial biomaterial scaffolds directly from CT or MRI data.
In this approach, voxel density distribution is used to define scaffold topology.
The scaffold design topology is created using image processing techniques. This
voxel density distribution is then converted to data that can be used to drive a
Solid Free-Form Fabrication machine to either directly build the scaffold or
build a mold for the scaffold. Several preliminary applications for craniofacial
surgery, including a mandibular condyle scaffold, an orbital floor scaffold, and
a general mandibular defect scaffold, are illustrated. Finally, we show
applications to in vivo models.
PMID- 10691149
TI - Unusual periosteal reaction caused by an accidentally displaced dental root.
PMID- 10691150
TI - The effect of suction drainage on microvascular anastomosis.
PMID- 10691151
TI - Standardization of HbA1c measurement--the issues.
PMID- 10691152
TI - Standardization of HbA1c measurements--a consensus statement.
PMID- 10691153
TI - Freezing method affects the concentration and variability of urine proteins and
the interpretation of data on microalbuminuria. The Oxford Regional Prospective
Study Group.
AB - AIMS: Microalbuminuria and, to a lesser extent, renal tubular proteins are widely
used in the early detection of incipient nephropathy in diabetes mellitus. Recent
reports have indicated detrimental effects of storage at -20 degrees C on urine
proteins. This study investigated the effects of storage on the measurement of
urine proteins and discusses implications for the interpretation of data.
METHODS: Two-hundred and sixty-eight specimens, collected from children with Type
1 diabetes, split into duplicate aliquots and stored at -20 degrees C and -70
degrees C, respectively, for 6-8 months, were analysed for albumin, retinol
binding protein, N-acetyl glucosaminidase and creatinine, in the same assays to
eliminate inter-assay variability. Two independent non-diabetic cohorts of
children provided urine specimens, which were stored at -20 degrees C for one
cohort and -70 degrees C for the other, to determine normal ranges for urine
proteins. RESULTS: Storage at -20 degrees C led to a variable underestimation of
all three urine proteins in 20% of specimens. Creatinine was unaffected. This
underestimation was greater in more concentrated urine (r2 = 0.38, P < 0.001, n =
262). Consequently storage at -20 degrees C increased the variance of the
albumin/ creatinine ratio more than the variance of albumin concentration.
Temperature of storage affected the normal range, which was 0.1-2.1 mg/mmol at
20 degrees C compared to 0.3-3.1 mg/mmol at -70 degrees C. The prevalence of
microalbuminuria (> 2SD above the geometric mean in non-diabetic specimens stored
at -20 degrees C) was 27% after storage at -70 degrees C vs. 24% after -20
degrees C. The prevalence of microalbuminuria (>2SD above the geometric mean in
nondiabetic specimens stored at -70 degrees C) was 21% after storage at -70
degrees C vs. 17% after -20 degrees C. CONCLUSIONS: Urine proteins are
significantly but variably underestimated after storage at -20 degrees C. These
effects account for increased variance and differences in the normal range, but
have less effect on the detection of microalbuminuria than might be predicted.
PMID- 10691154
TI - Predicting the occurrence of diabetes mellitus in recipients of heart
transplants.
AB - AIMS: To establish the incidence of post-transplant diabetes mellitus (PTDM) and
factors predictive of its development. METHODS: This was a retrospective review
(using hospital records and transplant database) of 97 consecutive adult patients
who underwent cardiac transplantation at St Vincent's Hospital, Sydney,
Australia. RESULTS: Mean follow-up was 27 months. Excluding five patients who had
pre-existing diabetes, the cumulative incidence of PTDM was 15.7%. Pre-transplant
random blood glucose (5.6 +/- 0.8 vs. 5.2 +/- 0.6 mmol/l, P<0.05), family history
(46% vs. 15%, P<0.05) and a continuing requirement for insulin on the second post
transplant day (54% vs. 15%, P< 0.01) differed in those who developed PTDM as
opposed to those who remained free of diabetes. Patients who developed PTDM had
received slightly higher mean doses of prednisolone at three months (0.21 +/-
0.03 vs. 0.19 +/- 0.03 mg. kg(-1)/day(-1), P<0.01). Of the factors identifiable
prior to initial hospital discharge, only family history of diabetes mellitus and
second post-transplant day insulin requirement independently predicted the
occurrence of PTDM. CONCLUSIONS: A family history of diabetes and the need for
insulin beyond the first 24 h after transplantation are factors identifiable
prior to hospital discharge, which predict patients at risk of developing PTDM.
In such patients, consideration to minimizing the dose of glucocorticoids should
be given where possible.
PMID- 10691155
TI - Acarbose treatment does not change the habitual diet of patients with Type 2
diabetes mellitus. The Finnish Acargbos Study Group.
AB - AIMS: It has been speculated that acarbose treatment in patients with Type 2
diabetes mellitus might induce changes in diet as a result of its adverse
gastrointestinal effects. The aim of this study was to determine whether poor
metabolic control can be improved by acarbose, and whether this might be because
the acarbose supplementation provokes changes in diet. METHODS: Poorly controlled
Type 2 diabetic patients treated with oral hypoglycaemic agents (OHA) were
randomized into either acarbose (100 mg t.d.s.) or placebo treatment. The double
blind treatment lasted for 24 weeks. Four-day food diaries and blood samples for
efficacy analysis were collected at 0, 4, 12, and 24 weeks. Thirty-six acarbose
and 39 placebo-treated patients completed the trial and were included in the
final analyses. RESULTS: At 24 weeks the baseline adjusted means of fasting, 1
and 2-h postprandial blood glucose values were 9.3 vs. 10.5 (P=0.02), 11.6 vs.
14.5 (P<0.001) and 11.0 vs. 13.7 mmol/l (P<0.001) and HbA1 9.3% vs. 10.2%
(P=0.002) in the acarbose and placebo groups, respectively. No significant
differences in nutrient intakes between groups were observed. The energy intake
and energy proportion of fat and carbohydrates remained unchanged in both groups.
CONCLUSIONS: Acarbose significantly improves metabolic control in Type 2 diabetic
patients poorly controlled with oral hypoglycaemic agents. This effect seems not
to be a result of concomitant involuntary dietary changes, since acarbose did not
induce modifications in diet during the study.
PMID- 10691156
TI - Universal vs. risk factor-based screening for gestational diabetes mellitus:
detection rates, gestation at diagnosis and outcome.
AB - AIMS: Gestational diabetes mellitus (GDM) is associated with adverse maternal and
fetal outcome. Screening for GDM is therefore recommended but the best screening
method remains controversial. This prospective, randomized study compared a risk
factor-based screening programme with a universally based one. METHODS: Subjects
were randomized at booking to one of two groups: the risk factor group had a 3-h
100-g oral glucose tolerance test (OGTT) at 32 weeks if any risk factor for GDM
was present; the universal group had a 50-g glucose challenge test performed and
if their plasma glucose at 1 h was > or = 7.8 mmol/l, a formal 3-h 100-g OGTT was
then performed. RESULTS: Universal screening detected a prevalence of GDM of
2.7%, significantly more than the 1.45% detected in the risk factor screened
group (P<0.03). Universal screening facilitated earlier diagnosis than risk
factor screening - mean gestation 30 +/- 2.6 weeks vs. 33 +/- 3.7 weeks (P<0.05).
A higher rate of spontaneous vaginal delivery at term, and lower rates of
macrosomia, Caesarean section, prematurity, pre-eclampsia and admission to
neonatal intensive care unit were observed in the universally screened, early
diagnosis group. CONCLUSIONS: Universal screening for GDM is superior to risk
factor based screening-detecting more cases, facilitating early diagnosis and is
associated with improved pregnancy outcome.
PMID- 10691157
TI - Perinatal mortality in Type 2 diabetes mellitus.
AB - AIMS: In many parts of the world the number of pregnancies in women with Type 2
diabetes mellitus (DM) now exceeds that in women with Type 1 DM, but there are
few data published on perinatal mortality in Type 2 DM. This study reports
observational data on perinatal mortality in Type 2 DM from a population with a
high background rate of this disorder. METHODS: Over a 12-year period (1985-1997)
at the Diabetes Clinic at National Women's Hospital, Auckland, there were 434
pregnancies in women with Type 2 DM (256 known and 178 diagnosed with gestational
diabetes mellitus (GDM), but confirmed to have Type 2 DM early post-partum), 160
pregnancies in women with Type 1 DM and 932 in women with GDM. Perinatal
mortality was classified as either intermediate fetal death (20-28 weeks'
gestation), late fetal death (28 weeks' gestation to term) or early neonatal
death (up to 1 month post-partum). RESULTS: The perinatal mortality in Type 2DM
was 46.1/1,000, significantly higher than the rates for the general population
(12.5), Type 1 DM (12.5) and GDM (8.9) (P < 0.0001). Congenital malformations
accounted for only 10% of the perinatal mortality. There was a seven-fold
increase in the rate of late fetal death and 2.5-fold increase in the rates of
intermediate fetal and late neonatal death. Subjects with Type 2 DM were
significantly older and more obese than subjects with Type 1 DM, and presented
later to the diabetes service. CONCLUSIONS: Perinatal mortality in Type 2 DM is
significantly increased, mainly owing to an excess of late fetal death. Maternal
factors such as obesity may be important contributors to the high perinatal
mortality. Women diagnosed with GDM who have unrecognized Type 2 DM are also at
high risk, but perinatal mortality is low in women with milder degrees of glucose
intolerance in pregnancy.
PMID- 10691158
TI - Addition of low-dose rosiglitazone to sulphonylurea therapy improves glycaemic
control in Type 2 diabetic patients.
AB - AIMS: This study was designed to test the efficacy and safety of low-dose
rosiglitazone, a potent, insulin-sensitizing thiazolidinedione, in combination
with sulphonylurea in Type 2 diabetic patients. METHODS: For the intention-to
treat analysis, 574 patients (59% male, mean age 61 years) were available,
randomized to receive 26 weeks of twice-daily placebo (n = 192), rosiglitazone 1
mg (n = 199) or rosiglitazone 2 mg (n = 183) in addition to existing
sulphonylurea treatment with gliclazide (47.6% of patients), glibenclamide
(41.8%) or glipizide (9.4%) (two patients were taking carbutamide or
glimepiride). Change in haemoglobin A1c (HbA1c), fasting plasma glucose (FPG),
fructosamine, insulin, C-peptide, albumin, and lipids were measured, and safety
was evaluated. RESULTS: Mean baseline HbA1c was 9.2% and FPG was 11.4 mmol/l.
Rosiglitazone at doses of 1 and 2 mg b.d. plus sulphonylurea produced significant
decreases, compared with sulphonylurea plus placebo, in HbA1c (-0.59% and -1.03%,
respectively; both P<0.0001) and FPG (1.35 mmol/l and 2.44 mmol/l, respectively;
both P<0.0001). Both HDL-cholesterol and LDL-cholesterol increased and
potentially beneficial decreases in non-esterified fatty acids and gamma glutamyl
transpeptidase levels were seen in both rosiglitazone groups. The overall
incidence of adverse experiences was similar in all three treatment groups, with
no significant cardiac events, hypoglycaemia or hepatotoxicity. CONCLUSIONS:
Overall, the combination of rosiglitazone and a sulphonylurea was safe, well
tolerated and effective in patients with Type 2 diabetes.
PMID- 10691159
TI - Placental size and large-for-gestational-age infants in women with abnormal
glucose tolerance in pregnancy.
AB - AIMS: To determine if the placental size is disproportionately increased in the
large-for-gestational age infants in pregnancies complicated by impaired glucose
tolerance. METHODS: A retrospective study was performed on 568 consecutive
singleton pregnancies complicated by gestational impaired glucose tolerance
controlled with diet and who delivered within a 15-month period. The cases were
categorized by the infant birthweight percentile into three groups, i.e. small
for-gestational age (< 10th percentile), appropriate-for-gestational age (10th to
90th percentile) and large-for-gestational age (> 90th percentile). Maternal and
infant anthropometric data, glycaemic status, and placental weight-to-birthweight
ratio were compared among the three groups. RESULTS: The infant body mass index
and placental weight showed a significantly increasing trend from the small-for
gestational age to the large-for-gestational age groups, but there was no
significant difference in the placental weight-to-birthweight ratio, values of
the oral glucose tolerance test, or haemoglobin A1c among the three groups. On
the other hand, the maternal body mass index before pregnancy and at delivery
were significantly higher in the large-for-gestational age group. The placental
weight, but not the ratio, was significantly correlated with the maternal body
mass index before pregnancy and at delivery (P < 0.001). CONCLUSIONS: The results
indicate that the placenta is not disproportionately bigger, and therefore
unlikely to be the cause, in large-for-gestational age infants. Maternal size
appeared to be the major determinant of birthweight percentile ranking in
pregnancies with gestational impaired glucose tolerance.
PMID- 10691160
TI - Leisure-time physical activity at weekends and the risk of Type 2 diabetes
mellitus in Japanese men: the Osaka Health Survey.
AB - AIMS: To investigate association between leisure-time physical activity at
weekends and the risk of developing Type 2 diabetes mellitus (DM). METHODS:
Prospective examination of 6,013 Japanese men aged 35-60 years who were free of
DM, impaired fasting glycaemia, or hypertension at study entry. Type 2 DM was
defined by a fasting plasma glucose level > or = 7.0 mmol/l or a 2-h post-load
plasma glucose level > or =11.1 mmol/l. Data on physical activity obtained from
questionnaires consisted of overall leisure-time physical activity weekly and
leisure-time physical activity at weekends. RESULTS: During the 59,966 person
years follow-up, 444 cases developed Type 2 DM. Regular physical exercise at
least once a week was associated with a reduced risk of Type 2 DM. After
adjustments for age, body mass index, daily alcohol consumption, smoking habits,
blood pressure levels and a parental history of Type 2 DM, men who engaged in
regular physical exercise at least once a week had a relative risk of Type 2 DM
of 0.75 (95% CI, 0.61-0.93) compared with men engaging in exercise less often.
Even vigorous activity only once a week at weekends was associated with a reduced
risk of Type 2 DM. Men who engaged in vigorous activity at least once a week at
weekends had a multiple-adjusted relative risk of Type 2 DM of 0.55 (95% CI, 0.35
0.88) compared with sedentary men. CONCLUSIONS: Regular physical exercise at
least once a week and vigorous activity even only once a week at weekends are
associated with a decreased risk of Type 2 DM.
PMID- 10691161
TI - Incidence of Type 1 diabetes mellitus in children aged 0-14 in Japan, 1986-1990,
including an analysis for seasonality of onset and month of birth: JDS study. The
Data Committee for Childhood Diabetes of the Japan Diabetes Society (JDS).
AB - AIMS: To detect the incidence of childhood Type 1 diabetes mellitus (DM) (0-14
years) in Japan and to find out whether there is a seasonal pattern in the onset
of disease and month of birth of children with diabetes. METHODS: Ascertained
data for the period 1986-1990 could be collected in 35 out of 47 local government
areas representing 69.4% of the childhood population (aged 0-14 years) of Japan.
RESULTS: A total of 1,260 children with Type 1 DM were identified (738 girls, 522
boys). With age there was a progressive increase in incidence from 0.7 to
2.1/10(5) in boys and from 0.6 to 3.5/10(5) in girls. With the exception of 1987,
when a coxsackie B3 virus epidemic was registered, no seasonal variation in the
month of onset was observed, nor was a seasonal pattern of the month of birth
registered in this cohort. CONCLUSIONS: Compared to European countries, the USA
and Israel, the Japanese cohort of children with diabetes presents the following
differences: the incidence is much lower, there is a preponderance of girls and
there is (with one exception) no seasonal pattern.
PMID- 10691162
TI - Type 1 diabetes mellitus in Czech children diagnosed in 1990-1997: a significant
increase in incidence and male predominance in the age group 0-4 years.
Collaborators of the Czech Childhood Diabetes Registry.
AB - AIMS: To overview total, age-and sex-specific incidence rates of type 1 diabetes
mellitus and their trends in Czech children 0-14 years of age in the period of
1990-1997. METHODS: Type 1 DM cases were ascertained by two independent sources,
data of general population were obtained from the annual demographic reports of
the State Statistic Bureau. Incidence rates were computed using both
ascertainment sources combined. RESULTS: In the study period 1.1.1990-31.12.1997,
the total incidence was 10.1 (95% CI 9.6-10.6) per 100,000/year in both sexes,
10.0 (95% CI 9.4-10.7) in boys, and 10.2 (95% CI 9.5-11.0) in girls. The total
age-standardized incidence was 9.9 (95% CI 9.4-10.4). The total incidence had a
significant increasing trend over the study period (P= 10(-4), annual increment
4.3%). A significant increasing trend was also found in the groups of children 0
4 (P = 0.033, increment 6.9%) and 5-9 years at diagnosis (P = 0.038, increment
4.8%). Statistically significant male predominance was observed in the group
diagnosed at age 0-4 years (boys/girls ratio of incidence 1.33, P = 0.035).
CONCLUSIONS: We report the first population-based epidemiological data on
incidence of childhood Type 1 DM in the Czech Republic. The incidence has
increased significantly during the last 8 years. The present incidence is at an
intermediate level compared to other European countries.
PMID- 10691163
TI - The care of students with insulin-treated diabetes mellitus living in university
accommodation: scope for improvement?
AB - Concern has been expressed about the welfare of young adults with Type 1 diabetes
mellitus who leave home to attend university or college for tertiary education.
This has been highlighted by the local experience in Edinburgh of two male
students with Type 1 diabetes, both of whom died from metabolic complications of
diabetes during their first term at universities distant from their homes. One
student died following the development of cerebral oedema secondary to diabetic
ketoacidosis, which was probably precipitated by prolonged coma after an episode
of severe hypoglycaemia. Another student, who was found 'dead in bed', had a
history of previous severe hypoglycaemia. At a Fatal Accident Inquiry in
Edinburgh, held following the death of the first student, recommendations were
made to improve the care and personal safety of students with diabetes living in
university accommodation. Despite the report being circulated to all Scottish
universities, the second student died within three years of the inquiry. Further
efforts to protect the welfare of students with Type 1 diabetes who are attending
centres for tertiary education away from their home environment may require the
more active participation by diabetes healthcare professionals.
PMID- 10691164
TI - 'Sausage toe': a reliable sign of underlying osteomyelitis.
AB - AIMS: To follow-up patients with a 'sausage' deformity of the toe associated with
local neuropathic ulceration to confirm the diagnosis of underlying
osteomyelitis. This was based on our observation that some diabetic patients with
suspected pedal osteomyelitis with a local neuropathic ulcer have a 'sausage'
deformity of a toe. METHODS: Over a period of 2 years, 14 patients with foot
ulcers, who were observed to have the 'sausage' deformity of a toe in the
diabetic foot clinic were followed up and investigated. RESULTS: Underlying
osteomyelitis was confirmed in six on the very first X-ray examination. A further
seven had osteomyelitis diagnosed on bone scanning. Both the X-ray and the bone
scan were equivocal in one patient, whose ulcer only healed after an 8-week
course of antibiotics. Antibiotic therapy was successful in 11 patients and three
patients required amputation of the affected toe. Following successful treatment,
there was full resolution of the 'sausage toe' in the majority. CONCLUSIONS: The
appearance of a 'sausage toe' should alert the physician of the possibility of
underlying osteomyelitis in diabetic foot, so that prompt treatment can be
commenced with antibiotics.
PMID- 10691165
TI - Adult learning and continuing education.
PMID- 10691166
TI - Persistent vomiting in patients with diabetes.
PMID- 10691167
TI - Metformin: a useful adjunct to insulin therapy?
PMID- 10691168
TI - Type 1 diabetes mellitus and hepatic sinusoidal fibrosis.
PMID- 10691169
TI - Electrocardiographic findings in a middle-aged African population in the
Seychelles islands.
AB - This study describes major electrocardiogram (ECG) measurements and diagnoses in
a population of African individuals; most reference data have been collected in
Caucasian populations and evidence exists for interethnic differences in ECG
findings. This study was conducted in the Seychelles islands (Indian Ocean) and
included 709 black individuals (343 men and 366 women) aged 25 to 64 years
randomly selected from the general population. Resting ECG were recorded by using
a validated ECG unit equipped with a measurement and interpretation software
(Cardiovit AT-6, Schiller, Switzerland). The epidemiology of 14 basic ECG
measurements, 6 composite criteria for left ventricular hypertrophy and 19
specific ECG diagnoses including abnormal rhythms, conduction abnormalities,
repolarization abnormalities, and myocardial infarction were examined.
Substantial gender and age differences were found for several ECG parameters.
Moreover, tracings recorded in African individuals of the Seychelles differed
from those collected similarly in Caucasian populations in many respects. For
instance, heart rate was approximately 5 beats per minute lower in the African
individuals than in selected Caucasian populations, prevalence of first degree
atrio-ventricular block was especially high (4.8%), and the average Sokolow-Lyon
voltage was markedly higher in African individuals of the Seychelles compared
with black and white Americans. The integrated interpretation software detected
"old myocardial infarction" in 3.8% of men and 0% of women and "old myocardial
infarction possible" in 6.1% and 3%, respectively. Cardiac infarction injury
scores are also provided. In conclusion, the study provides reference values for
ECG findings in a specific population of people of African descent and stresses
the need to systematically consider gender, age, and ethnicity when interpreting
ECG tracings in individuals.
PMID- 10691170
TI - Influence of autonomic tone on the filtered QRS duration from signal averaged
electrocardiograms in healthy volunteers.
AB - We recently reported that signal averaged electrocardiograms (SAECG) measurements
possess a circadian rhythm and are closely related to heart rate or heart rate
variability in healthy volunteers. This study determines the influence of
autonomic tone on the filtered QRS (f-QRS) duration from SAECG by using
pharmacologic autonomic blockade and exercise in healthy volunteers. Eleven
healthy male volunteers were studied. Three protocols were designed to study the
effects of exercise (Ex) under control conditions, beta adrenergic blockade or
double blockade. SAECGs and heart rate variability (LF and HF: low and high
frequency power, LF/HF ratio) were determined from Holter recordings. Ex
significantly decreased the f-QRS duration and HF and significantly increased
heart rate and LF/HF. Ex during beta adrenergic blockade significantly increased
heart rate and decreased f-QRS duration and HF, but did not change LF/HF. Ex
during double blockade did not affect the f-QRS duration, HF, or LF/HF. The
changes in f-QRS duration induced during Ex, autonomic blockade, or both were
inversely correlated with changes in heart rate and LF/HF and positively
correlated with changes in HF. These data suggest that f-QRS duration in healthy
subjects is shortened by Ex with increased sympathetic tone or decreased
parasympathetic tone or the combination.
PMID- 10691171
TI - Positional changes of spatial QRS- and ST-segment variables in normal subjects:
implications for continuous vectorcardiography monitoring during myocardial
ischemia.
AB - Electrocardiographic QRS- and ST-segment changes are to be expected during
changes in body posture. We prospectively analyzed the influence of changes in
body position on continuous vectorcardiography monitoring of QRS-vector
difference (QRS-VD) and ST change-vector magnitude (STC-VM) according to the
currently used criteria of myocardial ischemia in 21 normal subjects. Fifteen
(71%) and 6 (29%) subjects had significant positional QRS-VD and STC-VM changes,
respectively. Vectorcardiography changes were most frequent and pronounced in the
left lateral position. An alternative to the existing criterion of ischemia is
proposed to improve the specificity of STC-VM. Subjects with positional QRS-VD
changes had higher mean STC-VM values as compared with those without such
changes. Otherwise no characteristics among those with positional
vectorcardiography changes could be identified. There was no statistically
significant association between positional QRS-VD and STC-VM changes (R = .13, P
= .57). We conclude that the clinical use of QRS-VD in its present form for
continuous vectorcardiography monitoring of myocardial ischemia seems to be of
limited practical value, because of the presence of frequent "pseudo-ischemic"
changes. STC-VM seems to have a significant potential of continuous
vectorcardiography monitoring. However, an indicator of body position change or
even an algorithm enabling on-line correction for positional vectorcardiography
changes seems to be essential to improve the accuracy of this technique in
identifying myocardial ischemia.
PMID- 10691172
TI - Age-related changes in the magnitude of ventricular depolarization vector:
analyses by magnetocardiogram.
AB - The magnetocardiogram has the beneficial feature that permits the strength and
location of the current dipole to be estimated. This study examines the issue of
whether the magnitude of the heart current during depolarization phase was
influenced by the age of healthy subjects. The magnetocardiograms were recorded
by means of a second-derivative SQUID (superconducting quantum interference
device) magnetometer (BT Corp, Model BMP, San Diego, CA) in 150 healthy subjects.
The subjects were subgrouped into 5 age-based categories according to the age.
The current dipole of the maximum QRS complex was determined from isofield
contour maps during the ventricular depolarization phase, and no significant
differences were observed in the magnitude in the current source for any age
category. However, the amplitudes of the RV5 and SV1 + RV5 in the standard
electrocardiogram were larger in 65 to 74-year-old women than other age groups,
and the SV1 + RV5 was smaller for the 45 to 74-year-old men than for the men aged
25 to 44 years. These findings suggest that the age-associated changes in the QRS
complex observed by the electrocardiogram are caused by increased electric
resistance and not by the heart current itself. The results additionally suggest
that no effects of aging were observed in the actual heart current of the heart
during the depolarization phase.
PMID- 10691173
TI - Temporal evolution of traditional versus transformed ECG-based indexes in
patients with induced myocardial ischemia.
AB - The time course of changes in the electrocardiogram as a result of myocardial
ischemia induced during prolonged coronary angioplasty has been studied. We have
analyzed the electrocardiogram evolution during the occlusion in terms of the
Ischemic Changes Sensor, which is a parameter that describes the capacity of
different indexes to detect induced changes. Traditional indexes at specific time
locations (ST level, T wave amplitude and position, and durations of QT interval
and QRS complex) and global indexes (based on the Karhunen-Loeve transform as
applied to the QRS complex, ST-T complex, ST segment and T wave) have been
considered. The global indexes better detected ischemic changes than the
traditional indexes. The most sensitive were the index for the ST-T complex (89%)
in the Karhunen-Loeve transform-derived group and for the ST level (61%) in the
traditional group. Changes in the ventricular repolarization period usually
appeared earlier (77% of patients) than changes in the depolarization period (23%
of patients). A similar percentage of patients exhibited the earliest ischemic
changes in the T wave (41%) and in the ST segment (36%). The evolution of the
Ischemic Changes Sensor parameters showed that the majority (60%) of the total
changes occurred during the first minute of occlusion. The results suggest that
the use of global electrocardiogram indexes better reflect ischemic changes than
do traditional indexes, such as the ST segment deviation.
PMID- 10691174
TI - Cardiac rupture and admission electrocardiography in acute anterior myocardial
infarction: implication of ST elevation in aVL.
AB - This study determines the usefulness of electrocardiography in the emergency room
for assessing the risk of cardiac rupture after acute anterior myocardial
infarction (MI). The presence of ST segment elevation on the admission 12-lead
electrocardiography was evaluated in 325 consecutive anterior MI patients. A
forward-stepwise logistic regression analysis for cardiac rupture was performed
with the covariates of age, gender, hypertension, history of MI, reperfusion
therapy by coronary angioplasty, and ST segment elevations in leads I, aVL, V1
V6. Cardiac rupture occurred in 16 patients, including 7 with left ventricular
free wall rupture (FWR) and 9 with ventricular septal perforation (VSP). For FWR,
ST elevation in lead aVL was the only independent predictor (odds ratio = 12.1, P
= .0215). For VSP, female gender (odds ratio = 5.32, P = .0201) was the
independent predictor. In conclusion, in patients with acute anterior MI, ST
segment elevation in lead aVL on the admission electrocardiography is a
significant risk factor for left ventricular FWR.
PMID- 10691175
TI - Simulated torsade de pointes--the role of conduction defects and mechanism of QRS
rotation.
AB - A possible mechanism of torsade de pointes consisting of moving sites of reentry
in the presence of disparate recovery of excitability has been previously
proposed. This study evaluates the role of conduction defects in that mechanism.
A computer model that simulated propagation, cycle length dependent recovery of
excitability, and slow propagation during incomplete recovery and in conduction
defects was used. Localized conduction defects consisting of slow propagation
were shown to allow reentry at changing locations in the presence of uniform
recovery properties. Later activation within defects resulted in later recovery,
which permitted independent antegrade propagation adjacent to the defects.
Retrograde propagation in the defects then resulted in reentry. The location of
serial reentry changed because retrograde propagation and antegrade recovery had
opposing directions and met distal to the origin of antegrade excitation. This
mechanism was similar to that produced by disparate recovery and the combination
of conduction defects and disparate recovery permitted the mechanism to occur
with less marked disparity than otherwise required. The study also showed
bidirectional serial reentry around a localized conduction defect or region of
disparate recovery, which resulted in rotation of QRS peaks around the
isoelectric line. The study provided evidence that either conduction defects or
disparate recovery of excitability may be a substrate for torsade de pointes. It
also indicated that combination of these factors might permit torsade de pointes
when neither alone does so. This provides a possible explanation for the special
propensity of quinidine and other drugs that slow conduction as well as prolong
recovery to result in torsade de pointes. Findings also suggested a more explicit
mechanism for rotation of QRS peaks about the electrocardiogram baseline than was
previously available.
PMID- 10691176
TI - Heart transplantation: influence of the surgical technique on sinus function.
AB - This study analyzes the influence of the surgical technique on the development of
sinus dysfunction. Cycle length, corrected sinus node recovery time, and
sinoatrial conduction time were determined in 4 groups of dogs under the
following conditions: group 1, controls; group 2, subjected to heterotopic heart
transplantation with conservation of atrial anatomy; group 3, subjected to
orthotopic heart transplantation by using a standard technique; and group 4,
treated as in group 3, but with an ischemic time of 24 hours. The cycle length
was prolonged in all the treated groups when compared with the controls (P <
.01), an effect attributed to the disconnection of the autonomic nervous system
during the transplantation procedure. The corrected sinus node recovery time and
sinoatrial conduction time were significantly longer in all the animals in groups
3 and 4 when compared with those of groups 1 and 2 (P < .01); however, there were
no significant differences between groups 3 and 4 or between groups 1 and 2.
These results suggest that the atrial anatomy play a more relevant role than the
ischemic time in the origin of sinus dysfunction occurring after orthotopic heart
transplantation.
PMID- 10691177
TI - Marked anterograde decremental conduction over a rapidly conducting accessory
pathway after radiofrequency ablation.
AB - We report on a patient with the Wolff-Parkinson-White syndrome who temporarily
exhibited a marked anterograde decremental conduction over a rapidly conducting
accessory atrioventricular pathway after successful radiofrequency ablation. By
recording the intracardiac electrogram via the ablation catheter placed at the
successful ablation site, we were able to exclude the possibility of the
occurrence of anterograde decremental conduction in the atrial or ventricular
myocardium between the accessory pathway and the recording electrodes.
PMID- 10691178
TI - Simultaneous alterations of QRS configuration and tachycardia cycle length during
radiofrequency ablation of idiopathic left ventricular tachycardia.
AB - Idiopathic left ventricular tachycardia is characterized by a QRS morphology of
right bundle branch block pattern and left axis deviation. Alterations in the QRS
configuration and tachycardia cycle length, as well as shifting of the earliest
activation site occurred after eliminating the original tachycardia by
radiofrequency current in an 18-year-old man with idiopathic left ventricular
tachycardia. Activation mapping and entrainment mapping during tachycardia
identified 2 putative tachycardia exits, 15 mm apart. Elimination of both
tachycardias was accomplished after applying radiofrequency current to each exit
separately. We proposed that the first radiofrequency application might have
altered the exit site and the zone of slow conduction adjacent to the exit site,
such that the ventricular tachycardia had a different QRS morphology and became
slower in this patient.
PMID- 10691179
TI - Sinus escape-capture bigeminy and sinus extrasystolic bigeminy.
AB - Blocking conduction between the sinus node and the atria (SA block) can be
responsible for symptomatic rhythm problems. However, in atrial escape-capture
bigeminy with SA block, when atrial escape P waves originate in a site within or
close to the sinus node, the diagnosis of SA block is not easy.
Electrocardiograms were selected from 7 people with atrial bigeminy because (1)
all atrial deflections (P waves) were almost the same in shape and in length of
PR intervals, (2) comparatively long PP intervals alternated with comparatively
short PP intervals, and (3) occasionally the atrial bigeminy changed to normal
regular sinus rhythm in which 2 or more sinus P waves were found in succession.
An attempt is made to clarify the mechanism for these cases. When regular sinus
rhythm changed to bigeminal rhythm, the long PP interval introduced the bigeminy
in 3 cases, indicating the presence of "sinus" escape-capture bigeminy; whereas
the short PP interval introduced the bigeminy in the other 4 cases, indicating
the presence of "sinus" extrasystolic bigeminy. In cases of sinus escape-capture
bigeminy associated with SA block, the cases may occasionally be diagnosed
wrongly as ordinary sinus arrhythmia not associated with SA block. Therefore, it
seems that sinus escape-capture bigeminy is not so rare as is generally believed.
Patients with SA block often require implantation of the artificial pacemaker.
Thus, the authors believe that differentiation of sinus escape-capture bigeminy
from other forms of "sinus" bigeminy is clinically important.
PMID- 10691180
TI - Concealed conduction in the reentrant pathway as a mechanism of stable
ventricular quadrigeminy.
AB - This is the first report on the stable occurrence of ventricular quadrigeminy as
a manifestation of concealed bigeminy in a case of fixed and late coupled
ventricular extrasystoles. A 46-year-old man is reported in whom the period of
ventricular bigeminy alternated with the period of ventricular quadrigeminy.
Coupling intervals of the extrasystoles were fixed and much longer than sinus QT
intervals. When the heart rate is decreased, the period of bigeminy changed to
the period of quadrigeminy without gradual decrease in coupling of the preceding
extrasystoles. Once such a change occurred, stable quadrigeminy is maintained for
a period. These findings suggest the possibility that concealed electrotonic
conduction of blocked impulses and interference of conducted impulses may occur
in the reentrant extrasystolic pathway as a mechanism of stable ventricular
quadrigeminy.
PMID- 10691181
TI - Affinity labeling of oxaloacetate decarboxylase by novel dichlorotriazine linked
alpha-ketoacids.
AB - The 4-aminophenyloxanilic acid and beta-mercaptopyruvic acid linked to the
reactive diclorotriazine ring, were studied as active site-direct affinity labels
towards oxaloacetate decarboxylase (EC 4.1.1.3, OXAD). Oxaloacetate decarboxylase
when incubated with 4-aminophenyloxanilic-diclorotriazine (APOD) or beta
mercaptopyruvic-diclorotriazine (MPD) at pH 7.0 and 25 degrees C shows a time
dependent and concentration-dependent loss of enzyme activity. The inhibition was
irreversible and activity cannot be recovered either by extensive dialysis or gel
filtration chromatography. The enzyme inactivation following the Kitz & Wilson
kinetics for time-dependent irreversible inhibition. The observed rate of enzyme
inactivation (k(obs)) exhibits a non-linear dependence on APOD or MPD
concentration with maximum rate of inactivation (k3) of 0.013 min(-1) and 0.0046
min(-1) and K(D) equal to 20.3 and 156 microM respectively. The inactivation of
oxaloacetate decarboxylase by APOD and MPD is competitively inhibited by OXAD
substrate and inhibitors, such as oxaloacetate, ADP and oxalic acid whereas Mn+2
enhances the rate of inactivation. The rate of inactivation of OXAD by APOD shows
a pH dependence with an inflection point at 6.8, indicating a possible histidine
derivatization by the label. These results show that APOD and MPD demonstrate the
characteristics of an active-site probe towards the oxaloacetate binding site of
oxaloacetate decarboxylase.
PMID- 10691182
TI - Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by
sodium (2,2'-bipyridine) oxodiperoxovanadate.
AB - Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme,
which catalyzes the nonspecific hydrolysis of phosphate monoesters. The kinetics
of inhibition of the enzyme by sodium (2, 2'-bipyridine) oxodiperoxovanadate,
pV(bipy), has been studied. The time course of the hydrolysis of p-nitrophenyl
phosphate catalyzed by the enzyme in the presence of different pV(bipy)
concentrations showed that at each pV(bipy) concentration, the rate decreased
with increasing time until a straight line was approached, the straight line
slopes are the same for all concentrations. The results suggest that the
inhibition of the enzyme by pV(bipy) is a slow, reversible reaction with
fractional remaining activity. The microscopic rate constants are determined for
the reaction of inhibitor with the enzyme.
PMID- 10691183
TI - Kinetics of formation of antibody-ferric porphyrin complex with peroxidase
activity.
AB - The antibody 2B4 combines with ferric mesoporphyrin to form an antibody-ferric
mesoporphyrin complex which has a peroxidase activity. Formation of the complex
was investigated by measuring the absorption in the Soret region after mixing the
antibody and ferric mesoporphyrin. A rapid increase and a gradual decrease in the
absorption were observed, and the respective first-order rate constants were
obtained. From the dependence of values of the rate constants on the
concentration of ferric mesoporphyrin, the complex formation was explained by a
plausible mechanism, in which the antibody associated with ferric mesoporphyrin
to form the first complex followed by a conformational change to the second
complex. The first complex had almost the same peroxidase activity as that of the
second complex. Our results suggests that the antibody acquires the peroxidase
activity as soon as ferric mesoporphyrin is incorporated into its binding site,
and that there will be no protein ligand to the iron center of ferric
mesoporphyrin in the complex.
PMID- 10691184
TI - Determination of amino acid sequences of two subunits in sarcosine oxidase from
Corynebacterium sp. U-96.
AB - The primary structures of the C and D subunits of sarcosine oxidase from
Corynebacterium sp. U-96 were determined by sequencing the peptide fragments
derived from their enzymatic digestions. The C and D subunits were shown to be
composed of 199 and 92 residues, respectively. Each amino acid sequence showed a
high homology with the sequence of the corresponding subunit from Corynebacterium
sp. P-1. However, there were some differences between these two species, that is,
four N-terminal residues were truncated in the C subunit, but six C-terminal
residues were truncated in the D subunit. The D subunit contained three cysteine
residues, but no disulfide bonds are in the subunit. Overall sequences of both
subunit showed no homology with any other protein in the data base.
PMID- 10691185
TI - Molecular composition of progenitor toxin produced by Clostridium botulinum type
C strain 6813.
AB - The molecular composition of the purified progenitor toxin produced by a
Clostridium botulinum type C strain 6813 (C-6813) was analyzed. The strain
produced two types of progenitor toxins (M and L). Purified L toxin is formed by
conjugation of the M toxin (composed of a neurotoxin and a non-toxic
nonhemagglutinin) with additional hemagglutinin (HA) components. The dual
cleavage sites at loop region of the dichain structure neurotoxin were identified
between Arg444-Ser445 and Lys449-Thr450 by the analyses of C-terminal of the
light chain and N-terminal of the heavy chain. Analysis of partial amino acid
sequences of fragments generated by limited proteolysis of the neurotoxin has
shown to that the neurotoxin protein produced by C-6813 was a hybrid molecule
composed of type C and D neurotoxins as previously reported. HA components
consist of a mixture of several subcomponents with molecular weights of 70-, 55-,
33-, 26 through 21- and 17-kDa. The N-terminal amino acid sequences of 70-, 55-,
and 26 through 21-kDa proteins indicated that the 70-kDa protein was intact HA-70
gene product, and other 55- and 26 through 21-kDa proteins were derived from the
70-kDa protein by modification with proteolysis after translation of HA-70 gene.
Furthermore, several amino acid differences were exhibited in the amino acid
sequence as compared with the deduced sequence from the nucleotide sequence of
the HA-70 gene which was common among type C (strains C-St and C-468) and D
progenitor toxins (strains D-CB16 and D-1873).
PMID- 10691186
TI - Synthesis of aminobenzyltriethylenetetraaminohexaacetic acid: conjugation of the
chelator to protein by an alkylamine linkage.
AB - The conjugation of a chelating agent to an antibody as an anchoring site for a
radionuclide is the first step in the successful preparation of a radiolabeled
antibody for a diagnostic and therapeutic application. The high affinity of the
protein bound chelator towards radionuclide ensures a higher selectivity in the
delivery of the radionuclide to the targeted tissue. 4
Aminobenzylderivativetriethlenetetraaminohexaacetic acid (TTHA), a hexadentate
chelating agent has been now prepared for conjugation with proteins in view of
the higher affinity of TTHA metal ions as compared to DTPA. The latent
crosslinking potential of alpha-hydroxy aldehydes has been used to conjugate the
new chelating agent to proteins through an alkylamine linkage. On incubation of
amino benzyl TTHA with glycoladehyde at neutral pH and room temperature, the
reagent is converted to oxo ethyl amino benzyl TTHA. On addition of albumin to
this reaction mixture, the oxo ethylamino benzyl TTHA generates reversible schiff
base adducts with the amino groups of albumin. The reduction of the Schiff base
adducts of the chelator with the protein by sodium cyanoborohydride stabilizes
the schiff base adducts as stable alkylamine linkages. 4-Thiocyanatobenzyl TTHA
has also been prepared and conjugated to albumin through a thiocarbamoyl linkage.
Both preparations of TTHA conjugated albumin complexed with 99mTc and 111In, with
high affinity and no decomposition of the complex was noticed for at least up to
6 hrs after the preparation. The radiolabels complexed with these TTHA -albumin
conjugates could not be 'chased' out by free DTPA. A comparison of the
biodistribution of 111In, bound to the TTHA conjugated through an alkylamine and
a thiocarbamoyl linkage showed that 111In complexed with alkylamine linked TTHA
was retained in blood to a level nearly 17% higher compared to that seen with
thicarbamoyl linked TTHA, one hr after the injection into mice. Thus, the
alkylamine linkage appears to be more stable under the in vivo conditions. The
glycolaldehyde mediated alkylation procedure offers a mild, simple and rapid
method for preparation of drug-protein (antibody) conjugates.
PMID- 10691187
TI - Unfolding of hirudin characterized by the composition of denatured scrambled
isomers.
AB - The native core structure of hirudin, a thrombin specific inhibitor, contains 24
hydrogen bonds, two stretches of beta-sheet and three disulfide bonds. Hirudin
unfolds in the presence of denaturant and thiol catalyst by shuffling its native
disulfide bonds and converting to scrambled structures that consist of 11
identified isomers. The composition of scrambled isomers, which characterizes the
structure of denatured hirudin, varies as a function of denaturing conditions.
The unfolding pathway of hirudin has been constructed by quantitative analysis of
scrambled isomers unfolded under increasing concentrations of various
denaturants. The results demonstrate a progressive expansion of the polypeptide
chain and the existence of a structurally defined stable intermediate along the
pathway of unfolding.
PMID- 10691188
TI - Identification of protein C epitopes altered during its nanoencapsulation.
AB - Protein C is a plasmatic inhibitor which regulates the blood coagulation
mechanism by modulating the anticoagulant response. The improvement of its
bioavailability would be beneficial for the treatment of the disorders caused by
its homozygous deficiency or by an other plasmatic inhibitor deficiency. In this
context, the protein C encapsulation into biodegradable nanoparticles could be
used to approach the problem. However, the method used to prepare the
nanoparticles requires the use of ultrasonication and of an organic solvent such
as methylene chloride which interferes with protein activity. Sodium dodecyl
sulfate polyacrylamide gel electrophoresis showed that neither ultrasonication
nor methylene chloride, singly or in combination, led to protein C aggregation or
cleavage. Thus, a binding study using an ELISA assay with four characterized
monoclonal antibodies was carried out to identify the epitopes damaged by these
experimental constraints. The correlation between the immunological assay and a
functional one i.e. by the means of the assay of its anticoagulant activity
(activated partial thromboplastin time) made it possible to show that protein C
amino acids 166-169 of the activation peptide were probably altered after
ultrasonication and methylene chloride treatment. Indeed, it is likely that these
residues were no longer surface-exposed but had moved inside the protein core.
PMID- 10691189
TI - Conformational changes at the active site of pantetheine hydrolase during
denaturation by guanidine hydrochloride.
AB - Conformational changes at the active site of pantetheine hydrolase (EC3.5.1.-)
during guanidine hydrochloride (GndHCl) denaturation were investigated by UV and
circular dichroism spectroscopy and by electron spin resonance spectroscopy,
following the spectral behaviour of the nitroxide radicals (N-(1-oxyl-2,2,5,5,
tetramethyl-3-pyrrolidinyl) iodacetamide) covalently linked to the two active
site cysteine residues. At low denaturant concentrations (0.2 M) no
conformational changes may be observed, whereas the catalytic activity, is
strongly affected. The results indicate that the active site of pantetheine
hydrolase is labile and unfolds under conditions in which no global tertiary
structure modifications can be observed.
PMID- 10691190
TI - Attractor control of the redox reactions of bovine cytochrome c.
AB - Although the conformational changes accompanying the oxidation of ferrocytochrome
c by the transfer of an electron to cytochrome a are small, they may contribute
to the regulation of the electron transfer by transient storage of the liberated
energy as strain and atomic vibrations. Both the electron transfer and the
conformational changes seem to be controlled by an attractor, i.e. by a
manifestation of a deterministic chaos. The putative attractor is regular and is,
for the reaction involving the inner monomer of ferricytochrome c (I), of the
order of 3.03 +/- 0.03. The conformational changes involving the outer monomer of
ferricytochrome c (O) seem also to be controlled by a regular attractor, but its
order is 4.2 +/- 0.2. The low order of the coupled reactions of electron transfer
and conformational change suggests that it is essential to the electron transfer
process in the respiratory chain. Since the order of attractors of other proteins
correlates with the vectorial description of the function (1.0 for myoglobin, 2.0
for chymotrypsin and lysozyme, 3.0 for an abenzyme), the value for cyt. c
indicates that not only the electron transfer, but also an additional reaction,
e.g. the conformational change, are essential for the function of this protein.
Hence, the study of protein attractors may yield information on important
details, which could not be obtained by other methods.
PMID- 10691191
TI - Differences of reconstitution process between tobacco mosaic virus and cucumber
green mottle mosaic virus by synchrotron small angle X-ray scattering using low
temperature quenching.
AB - The differences of the reconstitution process of tobacco mosaic virus (TMV) and
its mutant, cucumber green mottle mosaic virus (CGMMV) were investigated by the
solution X-ray scattering measurements with the synchrotron radiation source
using low-temperature quenching. The reconstitution in an aqueous solution is
completely stopped below 5 degrees C. The TMV and CGMMV assembly was traced by
the small-angle X-ray scattering (SAXS) measurements at 5 degrees C on a series
of solutions prepared by low-temperature quenching after incubation at 20 degrees
C for an appropriate interval between 0 and 60 min. The SAXS results were
analyzed by the Guinier plot, the Kratky plot and the distance distribution
function. The incubation of RNA and protein of CGMMV did not reconstitute at the
initial reaction stages below 5 min and then began to reconstitute gradually.
After 60 min, the radius of gyration for CGMMV reconstitution process reached
almost the value for the initial stage of TMV reconstitution process. This is due
to the fact the formation of double-layered disk in CGMMV protein is much slower
than in TMV protein.
PMID- 10691192
TI - Pivot residue: an analysis of domain motion in proteins.
AB - In this study, we present an approach to identify some residues that represent
the pivot points to experience conformational changes between open (unligand) and
closed (ligand) forms of a protein. First, an angle, theta, formed by 4
consecutive Ca atoms in polypeptide backbones was introduced. The difference of
this angle, deltatheta, from the equivalent residues between the open and the
closed form was used to represent the local torsion changes in the protein
structure, and the residue with the maximum among deltatheta was identified to be
a pivot residue. We demonstrate the ability of our method by identifying the
pivot residues from five proteins, Lysozyme mutates, Lactoferrin, Lay/Arg/Orn
binding protein, Calmodulin and Catabolit gene activator protein. These pivot
residues are located at the hinges in the proteins, they are hinge points for the
domain motion. These examples also show that the pivot residues are useful to
distinguish the mechanism between shear motion and hinge motion in a protein.
PMID- 10691193
TI - New aspects in the molecular basis of polymer-associated infections due to
staphylococci.
AB - Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, cause
the majority of infections associated with both temporarily inserted and
permanently implanted foreign bodies. In recent years, the pathogenesis of
polymer-associated staphylococcal infection has become better understood, due in
part to the characterization of further associated factors. The bacterial factors
involved in the two phases of biofilm formation, i.e. the rapid adherence of
bacteria to the polymer surface and the subsequent, more prolonged, accumulation
phase, are presented in this review. The biofilm present on infected devices
plays an important role in the pathogenicity of the infecting organism by
protecting the embedded staphylococci and reducing the efficacy of host defenses
and antimicrobial killing.
PMID- 10691194
TI - New directions for future studies of community-acquired pneumonia: optimizing
impact on patient care.
PMID- 10691195
TI - Prospective study of community-acquired pneumonia of bacterial etiology in
adults.
AB - The aim of this study was to prospectively analyze the bacterial etiology of
community-acquired pneumonia in adults in Spain. From May 1994 to February 1996,
392 episodes of CAP diagnosed in the emergency department of a 600-bed university
hospital were studied. An etiological diagnosis based on noninvasive
microbiological investigations was achieved in 228 cases (58%); 173 of these
diagnoses were definitive and 55 probable. Streptococcus pneumoniae, which caused
23.9% of the episodes, was the predominant pathogen observed, followed by
Chlamydia pneumoniae (13.5%) and Legionella pneumophila (12.5%). Other less
frequent pathogens found were Haemophilus influenzae (2.3%), Pseudomonas
aeruginosa (1.5%), Mycoplasma pneumoniae (1.3%), Coxiella burnetii (1%),
Moraxella catarrhalis (2 cases), Nocardia spp. (2 cases), and Staphylococcus
aureus (2 cases). Streptococcus pneumoniae was significantly more frequent in
patients with underlying disease and/or age > or =60 years (28% vs. 13%, P =
0.002), while Legionella pneumophila was more frequent in patients below 60 years
of age and without underlying disease (20% vs. 9%, P = 0.006). Likewise,
Streptococcus pneumoniae and Legionella pneumophila were the most frequent
etiologies in patients requiring admission to the intensive care unit, occurring
in 29% and 26.3% of the patients, respectively. In addition to Streptococcus
pneumoniae, other microorganisms such as Chlamydia pneumoniae and Legionella spp.
should be seriously considered in adults with community-acquired pneumonia when
initiating empiric treatment or ordering rapid diagnostic tests.
PMID- 10691196
TI - Multiple mycoplasmal infections detected in blood of patients with chronic
fatigue syndrome and/or fibromyalgia syndrome.
AB - The aim of this study was to investigate the presence of different mycoplasmal
species in blood samples from patients with chronic fatigue syndrome and/or
fibromyalgia syndrome. Previously, more than 60% of patients with chronic fatigue
syndrome/fibromyalgia syndrome were found to have mycoplasmal blood infections,
such as Mycoplasma fermentans infection. In this study, patients with chronic
fatigue syndrome/fibromyalgia syndrome were examined for multiple mycoplasmal
infections in their blood. A total of 91 patients diagnosed with chronic fatigue
syndrome/fibromyalgia syndrome and with a positive test for any mycoplasmal
infection were investigated for the presence of Mycoplasma fermentans, Mycoplasma
pneumoniae, Mycoplasma hominis and Mycoplasma penetrans in blood using forensic
polymerase chain reaction. Among these mycoplasma-positive patients, infections
were detected with Mycoplasma pneumoniae (54/91), Mycoplasma fermentans (44/91),
Mycoplasma hominis (28/91) and Mycoplasma penetrans (18/91). Multiple mycoplasmal
infections were found in 48 of 91 patients, with double infections being detected
in 30.8% and triple infections in 22%, but only when one of the species was
Mycoplasma pneumoniae or Mycoplasma fermentans. Patients infected with more than
one mycoplasmal species generally had a longer history of illness, suggesting
that they may have contracted additional mycoplasmal infections with time.
PMID- 10691197
TI - Meropenem alone and in combination with vancomycin in experimental meningitis
caused by a penicillin-resistant pneumococcal strain.
AB - In a rabbit model of meningitis caused by a pneumococcus highly resistant to
penicillin (MIC, 4 microg/ml), meropenem, a broad-spectrum carbapenem, was
bactericidal (-0.48+/-0.14 deltalog10 cfu/ml h) and slightly superior to
ceftriaxone (-0.34+/-0.23 deltalog10 cfu/ml x h) and vancomycin (-0.39+/-0.19
deltalog10 cfu/ml x h). Although the combination of vancomycin with ceftriaxone
was significantly more active than ceftriaxone alone (-0.55+/-0.19 deltalog10
cfu/ml x h), only an insignificant gain was observed by the addition of
vancomycin to meropenem (-0.55+/-0.28 deltalog10 cfu/ml x h).
PMID- 10691198
TI - Mutations in the basal core promoter and precore/core gene of hepatitis B virus
in patients with chronic active but not acute hepatitis B.
AB - Around 5-10% of adults infected with hepatitis B virus (HBV) develop a chronic
liver disease such as chronic active hepatitis (CAH), and it is unclear whether
the clinical outcome depends solely on the immune response or whether viral
factors also play a role. In this study, a search was therefore made for
nucleotide mutations in the basic core promoter (BCP) and amino-acid
substitutions in the precore/core region of HBV infecting patients with CAH or
with acute hepatitis. The nucleotide sequences of the BCP and of the precore/core
region were determined in virus from ten patients with CAH and ten with acute
hepatitis. The precore/core sequences were also analysed in 14 additional
patients (6 with CAH, 8 with acute hepatitis). In seven of the ten patients with
CAH, five types of mutations were found in the BCP. Deletions in the precore/core
region were observed in six patients. In all six patients where only the
precore/core region was studied, amino-acid substitutions were present. In
contrast, in the ten patients with acute hepatitis studied for BCP, a mutation
was found in the BCP of one patient only. Of the 18 patients in whom the
precore/core was studied, three had an amino-acid substitution in this region.
The results show a clear link between CAH and both HBV BCP and precore/core
region mutations, suggesting these mutations may play a role in the persistence
of HBV infection.
PMID- 10691199
TI - Cell-culture system for continuous production of Toxoplasma gondii tachyzoites.
AB - The aim of this study was to identify a sustainable cell line and culture method
that could continuously provide a sufficient quantity of Toxoplasma gondii
tachyzoites to serve the needs of a general hospital laboratory. Three continuous
cell lines (HeLa, LLC and Vero) and three cell-culture methods (culture in
conventional flasks, culture in membrane-based flasks and an automated culture
system) were investigated. In multiplicity-of-infection and time-course
experiments, HeLa was the cell line of choice. Harvests from HeLa cells had
significantly higher tachyzoite yields than those from LLC cells (P<0.00005) or
Vero cells (P<0.05). Membrane-based flasks gave higher yields (6.15x10(6)
tachyzoites/ml) than conventional flasks (1-2x10(6) tachyzoites/ml) initially,
but these were not sustained. The automated cell-culture system was unsuitable
for parasite culture. Continuous passage in 25 cm2 flasks was successful,
yielding 1x10(6) tachyzoites/ml; viability exceeded 90% after 96-120 h of
infection throughout 38 passes, during which time the viability improved and the
time to harvest became more consistent. Toxoplasma gondii grown in continuous
culture in HeLa cells can provide a regular supply of viable tachyzoites.
Demonstration that HeLa-derived tachyzoites could be used for the dye test
confirms the potential of this in vitro system for use in general hospital
laboratories.
PMID- 10691200
TI - Efficacy of treatment with paromomycin, azithromycin, and nitazoxanide in a
patient with disseminated cryptosporidiosis.
AB - A 24-year-old HIV-positive heterosexual woman with disseminated cryptosporidiosis
was monitored from January 1998 to May 1999. During this period, consecutive
stool, sputum, and bile examinations showed the constant presence of
Cryptosporidium oocysts. Although the patient was repeatedly treated with oral
paromomycin and azithromycin and, finally, nitazoxanide, her condition continued
to deteriorate. In order to monitor the in vitro susceptibility of the parasite,
specimens from various sites were collected periodically. When the first clinical
isolate was tested, the antimicrobial agents used (azithromycin at a
concentration of 8 mg/l, paromomycin at of 1 mg/ml, and nitazoxanide at 10 mg/l)
produced a decrease in parasite counts of 26.5%, 63.4%, and 67.2%, respectively.
Subsequent isolates of Cryptosporidium parvum showed similar susceptibilities.
This case demonstrates that failure of clinical treatment corresponded to
inadequate growth inhibition of the parasite in vitro.
PMID- 10691201
TI - Role of Haemophilus influenzae in intra-amniotic infection in patients with
preterm rupture of membranes.
AB - Haemophilus spp. were isolated from the amniotic fluid of eight of 110
consecutive women with preterm premature rupture of membranes (PROM) between 1992
and 1998. Isolates were nontypeable and classified according to biochemical test
results as Haemophilus influenzae biotype I (n = 1), biotype II (n = 4), biotype
III (n = 1) or biotype IV (n = 2). Primers recognizing specific sequences in the
16S rRNA of the cryptic genospecies of Haemophilus were employed to amplify the
DNA of the eight isolates. One isolate classified as Haemophilus influenzae
biotype II was confirmed as belonging to the genital cryptic species. Infectious
morbidity occurred in five women and two newborns and was associated in most
cases with biotype II.
PMID- 10691202
TI - Pulmonary adiaspiromycosis in a patient with acquired immunodeficiency syndrome.
AB - Adiaspiromycosis is a noninfectious, nonarthropod-transmitted fungal infection
that occurs worldwide in lower vertebrates, especially rodents. However, humans
may become accidental hosts. Reported here is a case of adiaspiromycosis of the
lung in an HIV-positive, 40-year-old, bisexual man who first presented with cough
and dyspnea. Cultures of a bronchoalveolar lavage and protected brush specimen
revealed the presence of fungal elements that were identified as Emmonsia parva
var. parva. The patient was successfully treated with amphotericin B and
thereafter with fluconazole. This organism should be added to the list of
pathogens that cause pulmonary infection in AIDS patients.
PMID- 10691203
TI - Evaluation of a rapid immunochromatographic assay for the detection of Legionella
antigen in urine samples.
AB - A new immunochromatographic membrane assay for detecting Legionella pneumophila
serogroup 1 antigen in urine samples (Binax Now Legionella Urinary Antigen Test;
Binax, USA) was evaluated. Its sensitivity, specificity and level of agreement
with the Binax enzyme immunoassay were compared using nonconcentrated and
concentrated urine samples. The overall agreement between the two tests was
98.1%; the specificity of both was 100%. The sensitivity of the
immunochromatographic assay was 55.5% in nonconcentrated urine and 97.2% in
concentrated urine in comparison with the enzyme immunoassay, using concentrated
urine as the reference test. This immunochromatographic assay screens
successfully for Legionella pneumophila serogroup 1 soluble antigen in
concentrated urine samples.
PMID- 10691204
TI - Role of blood culture systems in the evaluation of epidemiological features of
coagulase-negative staphylococcal bloodstream infection in critically ill
patients.
AB - The impact of blood culture systems on the detection of coagulase-negative
staphylococcal bloodstream infections in critically ill patients prior to and
following the introduction of the Bactec 9240 blood culture system (Becton
Dickinson Diagnostic Instrument Systems, USA), which replaced the Bactec NR 730
(Becton Dickinson Diagnostic Instrument Systems), was investigated over a 3-year
period. Following the introduction of the new culture system, the incidence of
bloodstream infections doubled (P<0.001). Patient demographics, severity of
illness, and mortality remained unchanged, while the annual standardized
mortality ratio decreased significantly. These data suggest that blood culture
systems may have a major impact on the perceived incidence of coagulase-negative
staphylococcal bloodstream infections in this population.
PMID- 10691205
TI - Evaluation of an automated system for identification of Enterobacteriaceae and
nonfermenting bacilli.
AB - The performance of the Vitek 2 (bioMerieux, France), a new fully automated system
allowing rapid identification of microorganisms and susceptibility testing, and
the Vitek 2 ID-GNB card (bioMerieux) was evaluated using 502 clinical isolates
and stock collection strains of gram-negative rods belonging to 70 taxa. The
number of isolates correctly identified to species and genus levels was 430
(85.7%) and 485 (96.6%), respectively. Clinical isolates of both
Enterobacteriaceae and non-Enterobacteriaceae were better identified at the
species level (95.3% and 74%, respectively) than stock collection strains (86.4%
and 52.2%, respectively). The Vitek 2 ID-GNB card provides after 3 h a highly
acceptable level of accuracy for identification of Enterobacteriaceae and non
Enterobacteriaceae, including most atypical strains encountered in clinical
situations.
PMID- 10691206
TI - Comparative in vitro activity of quinolones against Stenotrophomonas maltophilia.
AB - The susceptibility of 109 Stenotrophomonas maltophilia isolates, all
characterized by pulsed-field gel electrophoresis, to nine quinolones was
studied. Grepafloxacin, trovafloxacin, and moxifloxacin displayed similar
intrinsic activities (MIC90, 0.5 microg/ml), which were lower than those of
ofloxacin and ciprofloxacin (MIC90, 4 microg/ml), norfloxacin (MIC90, 64
microg/ml), and nalidixic acid (MIC90, 32 microg/ml). Nalidixic acid was
generally one- to twofold dilutions more active than norfloxacin. According to
the criteria of the National Committee for Clinical Laboratory Standards (NCCLS),
the percentage of isolates susceptible to ciprofloxacin (breakpoint < or = 1
microg/ml) was 76.1%. Using the NCCLS breakpoint for comparative purposes, the
percentage of isolates susceptible to grepafloxacin, moxifloxacin, and
trovafloxacin was 95.4, 96.4, and 96.4%, respectively. These results indicate
that new quinolones may potentially be used for the management of
Stenotrophomonas maltophilia infections.
PMID- 10691207
TI - Comparison of two automated systems for the isolation of mycobacteria from
clinical specimens.
AB - The Bactec MGIT 960 (Becton-Dickinson, UK) automated mycobacterial liquid culture
system was compared with the Bactec 9000 MB (Becton-Dickinson) in order to assess
ease of use, diagnostic reliability and safety features. One thousand twenty-nine
clinical specimens were cultured in parallel, yielding a total of 125 (12.1%)
mycobacterial isolates, including 71 Mycobacterium tuberculosis and 18
Mycobacterium avium. The Bactec MGIT 960 demonstrated a mycobacterial recovery
rate and speed of detection equivalent to that of the Bactec 9000 MB for
clinically important isolates. The Bactec MGIT 960 integrates smoothly into
laboratory workflow, does not require needle inoculation and has a much larger
capacity than the Bactec 9000 MB.
PMID- 10691208
TI - Antimicrobial susceptibilities and biotypes of Arcanobacterium haemolyticum blood
isolates.
AB - Isolates obtained from the blood of ten patients with Arcanobacterium
haemolyticum septicaemia were biotyped as smooth or rough using morphological and
biochemical criteria, and their susceptibilities to 18 antibacterial agents were
determined. Nine of the clinical cases included here have not been reported
previously and are discussed in brief. One of the strains was highly resistant to
macrolides and clindamycin. With one exception, the strains belonged to the
smooth biotype. The data presented here indicates that the treatment of systemic
Arcanobacterium haemolyticum infections should be based on the antibacterial
susceptibility profiles of individual strains and on the site of the infection.
PMID- 10691209
TI - Bacteriology and clinical course of camel-bite wound infections.
PMID- 10691210
TI - Lack of effect of antibiotic resistance on susceptibility of microorganisms to
chlorhexidine gluconate or povidone iodine.
PMID- 10691211
TI - Rostral spread of epidural morphine: the expected and the unexpected.
PMID- 10691212
TI - The direct search procedure: a new approach to evaluating clinical regimens.
PMID- 10691213
TI - Dopamine: one size does not fit all.
PMID- 10691214
TI - Improving splanchnic perfusion during cardiopulmonary bypass.
PMID- 10691215
TI - Preemptive hyperalgesia, not analgesia?
PMID- 10691216
TI - Lumbar epidural morphine in humans and supraspinal analgesia to experimental heat
pain.
AB - BACKGROUND: Epidural administration of morphine is a common analgesic technique
to manage pain. Morphine spreads from the epidural space to the cerebrospinal
fluid and then rostrally, causing side effects mediated by the brain stem.
However, data on the rostral spread of morphine-mediated analgesia are sparse.
This study examined the rostral spread of analgesic effects on heat and
electrical pain after epidural administration of morphine. METHODS: In a
randomized, double-blinded, placebo-controlled, crossover study, 5 mg morphine or
saline placebo were injected into the lumbar epidural space in nine healthy
volunteers. Correct needle placement was confirmed with fluoroscopy. Analgesia to
experimental nociceptive heat and electrical stimuli was measured at lumbar (L4),
thoracic (T10), cervical (C2), and trigeminal (V2) levels before and 2, 5, 10,
and 24 h after epidural injection. Plasma samples for assaying morphine
concentrations were drawn before and after each analgesic evaluation. RESULTS:
Epidural morphine significantly attenuated experimental heat pain at all
dermatomes tested compared with saline placebo. Analgesic effects were
significant at L4 after 2, 5, and 10 h, at T10 after 5, 10, and 24 h, and at V2
after 10 h. Electrical pain was attenuated at the lumbar and thoracic but not at
the cervical dermatome. Analgesic effects were significant at L4 after 2, 5, and
10 h and at T10 after 5 and 10 h. Morphine plasma concentrations were below the
detection limit (1 ng/ml) in eight of the nine subjects 10 h after epidural
injection. CONCLUSIONS: Lumbar epidural injection of morphine attenuated
cutaneous heat pain up to the trigeminal dermatome during a 24-h observation
period. In a clinical context, this implies that some types of pain may be
attenuated up to the supraspinal level after lumbar epidural administration of
morphine.
PMID- 10691217
TI - A direct search procedure to optimize combinations of epidural bupivacaine,
fentanyl, and clonidine for postoperative analgesia.
AB - BACKGROUND: The authors applied an optimization model (direct search) to find the
optimal combination of bupivacaine dose, fentanyl dose, clonidine dose, and
infusion rate for continuous postoperative epidural analgesia. METHODS: One
hundred ninety patients undergoing 48-h thoracic epidural analgesia after major
abdominal surgery were studied. Combinations of the variables of bupivacaine
dose, fentanyl dose, clonidine dose, and infusion rate were investigated to
optimize the analgesic effect (monitored by verbal descriptor pain score) under
restrictions dictated by the incidence and severity of side effects. Six
combinations were empirically chosen and investigated. Then a stepwise
optimization model was applied to determine subsequent combinations until no
decrease in the pain score after three consecutive steps was obtained. RESULTS:
Twenty combinations were analyzed. The optimization procedure led to a reduction
in the incidence of side effects and in the mean pain scores. The three best
combinations of bupivacaine dose (mg/h), fentanyl dose (microg/h), clonidine dose
(microg/h), and infusion rate (ml/h) were: 9-21-5-7, 8-30-0-9, and 13-25-0-9,
respectively. CONCLUSIONS: Given the variables investigated, the aforementioned
combinations may be the optimal ones to provide postoperative analgesia after
major abdominal surgery. Using the direct search method, the enormous number of
possible combinations of a therapeutic strategy can be reduced to a small number
of potentially useful ones. This is accomplished using a scientific rather than
an arbitrary procedure.
PMID- 10691218
TI - Pharmacokinetics of dopamine in healthy male subjects.
AB - BACKGROUND: Dopamine is an agonist of alpha, beta, and dopaminergic receptors
with varying hemodynamic effects depending on the dose of drug being
administered. The purpose of this study was to measure plasma concentrations of
dopamine in a homogeneous group of healthy male subjects to develop a
pharmacokinetic model for the drug. Our hypothesis was that dopamine
concentrations can be predicted from the infusion dose using a population-based
pharmacokinetic model. METHODS: Nine healthy male volunteers aged 23 to 45 yr
were studied in a clinical research facility within our academic medical center.
After placement of venous and arterial catheters, dopamine was infused at 10
microg x kg(-1) x min(-1) for 10 min, followed by a 30-min washout period.
Subsequently, dopamine was infused at 3 microg x kg(-1) x min(-1) for 90 min,
followed by another 30-min washout period. Timed arterial blood samples were
centrifuged, and the plasma was analyzed by high-performance liquid
chromatography. Mixed-effects pharmacokinetic models using NONMEM software
(NONMEM Project Group, University of California, San Francisco, CA) were used to
determine the optimal compartmental pharmacokinetic model for dopamine. RESULTS:
Plasma concentrations of dopamine varied from 12,300 to 201,500 ng/l after 10 min
of dopamine infusion at 10 microg x kg(-1) x min(-1). Similarly, steady-state
dopamine concentrations varied from 1,880 to 18,300 ng/l in these same subjects
receiving 3-microg x kg(-1) x min(-1) infusions for 90 min. A two-compartment
model adjusted for body weight was the best model based on the Schwartz-Bayesian
criterion. CONCLUSIONS: Despite a homogeneous population of healthy male subjects
and weight-based dosing, there was 10- to 75-fold intersubject variability in
plasma dopamine concentrations, making standard pharmacokinetic modeling of less
utility than for other drugs. The data suggest marked intraindividual and
interindividual variability in dopamine distribution and/or metabolism. Thus,
plasma dopamine concentrations in patients receiving dopamine infusion at
identical rates may vary profoundly. Our data suggest that dosing dopamine based
on body weight does not yield predictable blood concentrations.
PMID- 10691219
TI - Efficacy of neurolytic celiac plexus block in varying locations of pancreatic
cancer: influence on pain relief.
AB - BACKGROUND: Neurolytic celiac plexus block (NCPB) is an effective way of treating
severe pain in some patients with pancreatic malignancy. However, there are no
studies to date that evaluate the effectiveness of NCPB related to the site of
primary pancreas cancer. The aim of the study was to assess the effectiveness of
NCPB in pancreatic cancer pain, depending on the location of the pancreatic
tumor. METHODS: The prospective study was conducted in 50 consecutive patients
diagnosed with pancreatic cancer. The patients were categorized into two
different groups depending on tumor localization: group 1: patients with the
cancer of the head of the pancreas and group 2: patients with the cancer of the
body and tail of the pancreas. The qualitative and quantitative pain analyses
were performed before and after NCPB. The patients underwent prognostic celiac
plexus block with bupivacaine, followed by neurolysis during fluoroscopic control
within the next 24 h. RESULTS: After NCPB, 37 patients (74%) had effective pain
relief during the first 3 months or until death. Of the 37 patients who had
effective pain relief, 33 (92%) were from group 1 and 4 (29%) were from group 2.
In the remaining 13 patients (3 patients from group 1 and 10 patients from group
2), pain relief after NCPB was not satisfactory. Those patients were scheduled
for repeated retrocrural neurolysis during computed tomography control. Computed
tomography showed massive growth of the tumor around the celiac axis with
metastases. After repeated neurolysis, pain relief clinically still was not
satisfactory, necessitating additional opioid treatment. CONCLUSION: In this
study, unilateral transcrural celiac plexus neurolysis has been shown to provide
effective pain relief in 74% of patients with pancreatic cancer pain. Neurolysis
was more effective in cases with tumor involving the head of the pancreas. In the
cases with advanced tumor proliferation, regardless of the technique used, the
analgesic effects of NCPB were not satisfactory.
PMID- 10691220
TI - Preemptive intravenous morphine-6-glucuronide is ineffective for postoperative
pain relief.
AB - BACKGROUND: Morphine-6-glucuronide (M-6-G), a major metabolite of morphine, is
reported to be more potent than morphine when administered intrathecally;
however, its efficiency remains under debate when administered intravenously.
This study was designed to assess the analgesic efficiency of intravenous M-6-G
for the treatment of acute postoperative pain. METHODS: After informed consent
was obtained, 37 adults (American Society of Anesthesiologists physical status I
II) who were scheduled for elective open knee surgery were enrolled in the study.
General anesthesia was induced with thiopental, alfentanil, and vecuronium and
was maintained with a mixture of nitrous oxide/isoflurane and bolus doses of
alfentanil. At skin closure, patients were randomized into three groups: (1)
morphine group (n = 13), which received morphine 0.15 mg/kg; (2) M-6-G group (n =
12), which received M-6-G 0.1 mg/kg; and (3) placebo group (n = 12), which
received saline. At the time of extubation, plasma concentration of morphine and
M-6-G was measured. Postoperative analgesic efficiency was assessed by the
cumulative dose of morphine delivered by patient-controlled analgesia. Opioid
related side effects were also evaluated. RESULTS: No difference was noted in
patient characteristics and opioid-related side effects. Morphine requirements
(mean +/- SD) during the first 24 h in the M-6-G group (41+/-9 mg) and the
placebo group (49+/-8 mg) were significantly greater (P<0.05) compared with the
morphine group (29+/-8 mg). CONCLUSION: A single intravenous bolus dose of M-6-G
was found to be ineffective in the treatment of acute postoperative pain. This
might be related to the low permeability of the blood-brain barrier for M-6-G.
PMID- 10691221
TI - Low-dose clonidine and neostigmine prolong the duration of intrathecal
bupivacaine-fentanyl for labor analgesia.
AB - BACKGROUND: Intrathecal (IT) opioid and local anesthetic combinations are popular
for labor analgesia because of rapid, effective pain relief, but the duration of
analgesia is limited. This study was undertaken to determine whether the addition
of clonidine and neostigmine to IT bupivacaine-fentanyl would increase the
duration of analgesia without increasing side effects for patients in labor.
METHODS: Forty-five healthy parturients in active labor were randomized to
receive a 2-ml IT dose of one of the following dextrose-containing solutions
using the combined spinal-epidural technique: (1) bupivacaine 2.5 mg and fentanyl
25 microg (BF); (2) BF plus clonidine 30 microg (BFC); or (3) BFC plus
neostigmine 10 microg (BFCN). Pain, sensory levels, motor block, side effects,
maternal vital signs, and fetal heart rate were systematically assessed. RESULTS:
Patients administered BFCN had significantly longer analgesia (165+/-32 min) than
those who received BF (90+/-21 min; P<0.001) or BFC (123+/-21 min; P<0.001). Pain
scores, block characteristics, maternal vital signs, Apgar scores, maternal
satisfaction, and side effects were similar among groups except for nausea, which
was significantly greater in the BFCN group (P<0.05 as compared with BFC).
CONCLUSIONS: The addition of clonidine and neostigmine significantly increased
the duration of analgesia from IT bupivacaine-fentanyl during labor, but
neostigmine caused more nausea. Although serious side effects were not observed
in this study, safety must be further addressed before the routine use of
multiple IT drugs is advocated.
PMID- 10691222
TI - Bedside assessment of cerebral blood flow by double-indicator dilution technique.
AB - BACKGROUND: Currently, quantitative measurement of global cerebral blood flow
(CBF) at bedside is not widely performed. The aim of the present study was to
evaluate a newly developed method for bedside measurement of CBF based on
thermodilution in a clinical setting. METHODS: The investigation was performed in
14 anesthetized patients before coronary bypass surgery. CBF was altered by
hypocapnia, normocapnia, and hypercapnia. CBF was measured simultaneously by the
Kety-Schmidt inert-gas technique with argon and a newly developed transcerebral
double-indicator dilution technique (TCID). For TCID, bolus injections of ice
cold indocyanine green were performed via a central venous line, and the
resulting thermo-dye dilution curves were recorded simultaneously in the aorta
and the jugular bulb using combined fiberoptic thermistor catheters. CBF was
calculated from the mean transit times of the indicators through the brain.
RESULTS: Both methods of measurement of CBF indicate a decrease during hypocapnia
and an increase during hypercapnia, whereas cerebral metabolic rate remained
unchanged. Bias between CBF(TCID) and CBFargon was -7.1+/-2.2 (SEM) ml x min(-1)
x 100 g(-1); precision (+/- 2 x SD of differences) between methods was 26.6 ml x
min(-1) x 100 g(-1). CONCLUSIONS: In the clinical setting, TCID was feasible and
less time-consuming than alternative methods. The authors conclude that TCID is
an alternative method to measure global CBF at bedside and offers a new
opportunity to monitor cerebral perfusion of patients.
PMID- 10691223
TI - Pharmacokinetics of rapacuronium in infants and children with intravenous and
intramuscular administration.
AB - BACKGROUND: A nondepolarizing muscle relaxant with an onset and offset profile
similar to succinylcholine is desirable for pediatric anesthesia. The onset and
offset of rapacuronium are rapid in children. In the current study, the authors
determined its pharmacokinetic characteristics in children. In addition to
administering rapacuronium by the usual intravenous route, the authors also gave
rapacuronium intramuscularly to determine uptake characteristics and
bioavailability. METHODS: Forty unpremedicated patients aged 2 months to 3 yr
were anesthetized with halothane, 0.82-1.0% end-tidal concentration. When
anesthetic conditions were stable, rapacuronium was injected either into a
peripheral vein (2 mg/kg for infants, 3 mg/kg for children) or a deltoid muscle
(2.8 mg/kg for infants, 4.8 mg/kg for children). Four venous plasma samples were
obtained from each subject 2-240 min after rapacuronium administration. A mixed
effects population pharmacokinetic analysis was applied to these values to
determine bioavailability, absorption rate constant, and time to peak plasma
concentration with intramuscular administration. RESULTS: Plasma clearance was
4.77 ml x kg(-1) x min(-1) + 8.48 ml/min. Intramuscular bioavailability averaged
56%. Absorption from the intramuscular depot had two rate constants: 0.0491 min(
1) (72.4% of absorbed drug) and 0.0110 min(-1) (27.6% of the absorbed drug).
Simulation indicated that plasma concentration peaks 4.0 and 5.0 min after
intramuscular rapacuronium in infants and children, respectively, and that, at 30
min, less than 25% of the administered dose remains to be absorbed from the
intramuscular depot. CONCLUSIONS: In infants and children, rapacuronium's
clearance and steady state distribution volume are less than in adults. After
intramuscular administration, bioavailability is 56%, and plasma rapacuronium
concentrations peak within 4 or 5 min.
PMID- 10691224
TI - Walking with labor epidural analgesia: the impact of bupivacaine concentration
and a lidocaine-epinephrine test dose.
AB - BACKGROUND: Regional analgesia techniques for labor that permit ambulation are
popular among parturients. This study evaluated the influence of bupivacaine
bolus concentration and a 3-ml 1.5% lidocaine-epinephrine test dose, on analgesic
effectiveness and the ability to walk after block placement. METHODS: Using a
randomized double-blind study design, epidural analgesia was initiated in 60
parturients undergoing labor as follows: Group TD/B.0625 received a 3-ml
lidocaine-epinephrine test dose + 12 ml bupivacaine, 0.0625%; group TD/B.125
received a 3-ml test dose + 12 ml bupivacaine, 0.125%; group B.0625 received 15
ml bupivacaine, 0.0625% (no test dose); and group B.125 received 15 ml
bupivacaine, 0.125% (no test dose). Initial boluses in all groups contained 10
microg sufentanil. Bupivacaine, 0.0625%, with 0.33 microg/ml sufentanil was
infused throughout labor at 13.5-15 ml/h. Analgesia balance, proprioception,
motor block, and patient ability to stand and walk were evaluated at various
intervals. RESULTS: A bolus of 0.125% bupivacaine containing sufentanil, without
a previous test dose, proved to be optimal with respect to analgesia and early
ambulation. When a test dose was given before bupivacaine, 0.125%, fewer women
walked within 1 h of block placement. Bupivacaine, 0.0625%, with sufentanil, with
or without a test dose, provided inadequate analgesia, necessitating additional
bupivacaine, which impaired the ability to walk. A high percentage of women in
all groups (73-93%) walked at some stage during labor. CONCLUSIONS: Omitting a
lidocaine-epinephrine test dose and using 0.125% bupivacaine for the initial
bolus should permit ambulation in the early postblock period for most parturients
who elect this option.
PMID- 10691225
TI - The pharmacodynamic effect of a remifentanil bolus on ventilatory control.
AB - BACKGROUND: In doses typically administered during conscious sedation,
remifentanil may be associated with ventilatory depression. However, the time
course of ventilatory depression after an initial dose of remifentanil has not
been determined previously. METHODS: In eight healthy volunteers, the authors
determined the time course of the ventilatory response to carbon dioxide using
the dual isohypercapnic technique. Subjects breathed via mask from a to-and-fro
circuit with variable carbon dioxide absorption, allowing the authors to maintain
end-tidal pressure of carbon dioxide (PET(CO2)) at approximately 46 or 56 mm Hg
(alternate subjects). After 6 min of equilibration, subjects received 0.5
microg/kg remifentanil over 5 s, and minute ventilation (V(E)) was recorded
during the next 20 min. Two hours later, the study was repeated using the other
carbon dioxide tension (56 or 46 mm Hg). The V(E) data were used to construct two
point carbon dioxide response curves at 30-s intervals after remifentanil
administration. Using published pharmacokinetic values for remifentanil and the
method of collapsing hysteresis loops, the authors estimated the effect-site
equilibration rate constant (k(eo)), the effect-site concentration producing 50%
respiratory depression (EC50), and the shape parameter of the concentration
response curve (gamma). RESULTS: The slope of the carbon dioxide response
decreased from 0.99 [95% confidence limits 0.72 to 1.26] to a nadir of 0.27 l x
min(-1) x mm Hg(-1) [-0.12 to 0.66] 2 min after remifentanil (P<0.001); within 5
min, it recovered to approximately 0.6 l x min(-1) x mm Hg(-1), and within 15 min
of injection, slope returned to baseline. The computed ventilation at PET = 50 mm
Hg (VE50) decreased from 12.9 [9.8 to 15.9] to 6.1 l/min [4.8 to 7.4] 2.5 min
after remifentanil injection (P<0.001). This was caused primarily by a decrease
in tidal volume rather than in respiratory rate. Estimated pharmacodynamic
parameters based on computed mean values of VE50 included k(eo) = 0.24 min(-1)
(T1/2 = 2.9 min), EC50 = 1.12 ng/ml, and gamma = 1.74. CONCLUSIONS: After
administration of 0.5 microg/kg remifentanil, there was a decrease in slope and
downward shift of the carbon dioxide ventilatory response curve. This reached its
nadir approximately 2.5 min after injection, consistent with the computed onset
half-time of 2.9 min. The onset of respiratory depression appears to be somewhat
slower than previously reported for the onset of remifentanil-induced
electroencephalographic slowing. Recovery of ventilatory drive after a small dose
essentially was complete within 15 min.
PMID- 10691226
TI - Comparison of plasma compartment versus two methods for effect compartment-
controlled target-controlled infusion for propofol.
AB - BACKGROUND: Target-controlled infusion (TCI) systems can control the
concentration in the plasma or at the site of drug effect. A TCI system that
targets the effect site should be able to accurately predict the time course of
drug effect. The authors tested this by comparing the performance of three
control algorithms: plasmacontrol TCI versus two algorithms for effect-site
control TCI. METHODS: One-hundred twenty healthy women patients received propofol
via TCI for 12-min at a target concentration of 5.4 microg/ml. In all three
groups, the plasma concentrations were computed using pharmacokinetics previously
reported. In group I, the TCI device controlled the plasma concentration. In
groups II and III, the TCI device controlled the effect-site concentration. In
group II, the effect site was computed using a half-life for plasma effect-site
equilibration (t1/2k(eo)) of 3.5 min. In group III, plasma effect-site
equilibration rate constant (k(eo)) was computed to yield a time to peak effect
of 1.6 min after bolus injection, yielding a t1/2keo of 34 s. the time course of
propofol was measured using the bispectral index. Blood pressure, ventilation,
and time of loss of consciousness were measured. RESULTS: The time course of
propofol drug effect, as measured by the bispectral index, was best predicted in
group III. Targeting the effect-site concentration shortened the time to loss of
consciousness compared with the targeting plasma concentration without causing
hypotension. The incidence of apnea was less in group III than in group II.
CONCLUSION: Effect compartment-controlled TCI can be safely applied in clinical
practice. A biophase model combining the Marsh kinetics and a time to peak effect
of 1.6 min accurately predicted the time course of propofol drug effect.
PMID- 10691227
TI - Critical oxygen delivery in conscious humans is less than 7.3 ml O2 x kg(-1) x
min(-1).
AB - BACKGROUND: The "critical" level of oxygen delivery (DO2) is the value below
which DO2 fails to satisfy the metabolic need for oxygen. No prospective data in
healthy, conscious humans define this value. The authors reduced DO2 in healthy
volunteers in an attempt to determine the critical DO2. METHODS: With
Institutional Review Board approval and informed consent, the authors studied
eight healthy, conscious volunteers, aged 19-25 yr. Hemodynamic measurements were
obtained at steady state before and after profound acute isovolemic hemodilution
with 5% albumin and autologous plasma, and again at the reduced hemoglobin
concentration after additional reduction of DO2 by an infusion of a beta
adrenergic antagonist, esmolol. RESULTS: Reduction of hemoglobin from 12.5+/-0.8
g/dl to 4.8+/-0.2 g/dl (mean +/- SD) increased heart rate, stroke volume index,
and cardiac index, and reduced DO2 (14.0+/-2.9 to 9.9+/-20 ml O2 x kg(-1) x min(
1); all P<0.001). Oxygen consumption (VO2; 3.0+/-0.5 to 3.4+/-0.6 ml O2 x kg(-1)
x min(-1); P<0.05) and plasma lactate concentration (0.50+/-0.10 to 0.62+/-0.16
mM; P<0.05; n = 7) increased slightly. Esmolol decreased heart rate, stroke
volume index, and cardiac index, and further decreased DO2 (to 7.3+/-1.4 ml O2 x
kg(-1) x min(-1); all P<0.01 vs. before esmolol). VO2 (3.2+/-0.6 ml O2 x kg(-1) x
min(-1); P>0.05) and plasma lactate (0.66+/-0.14 mM; P>0.05) did not change
further. No value of plasma lactate exceeded the normal range. CONCLUSIONS: A
decrease in DO2 to 7.3+/-1.4 ml O2 x kg(-1) min(-1) in resting, healthy,
conscious humans does not produce evidence of inadequate systemic oxygenation.
The critical DO2 in healthy, resting, conscious humans appears to be less than
this value.
PMID- 10691228
TI - Female gender associates with increased duration of intubation and length of stay
after coronary artery surgery. CABG Clinical Benchmarking Database Participants.
AB - BACKGROUND: Females have worse outcome than do males after coronary artery bypass
grafting; however, gender effects on length of stay (LOS) outcomes, such as
duration of intubation or intensive care unit (ICU) LOS, have not been evaluated
previously. The authors hypothesized that adjustment for pertinent preoperative
covariates would eliminate any significant effect of gender on duration of
intubation, LOS in the ICU after extubation, total ICU LOS, postoperative
(exclusive of ICU) LOS, or total postoperative LOS. METHODS: Patients undergoing
elective or urgent primary coronary artery bypass grafting surgery at 51 academic
health centers in 1995 and 1997 were studied. Unique multivariable statistical
models were developed for duration of intubation, ICU LOS after extubation, total
ICU LOS, and postoperative (exclusive of ICU and total) LOS to test for
independent associations with gender. Preoperative but not intraoperative or
postoperative variables were included in the model. P> or =0.01 was considered
significant. RESULTS: All LOSs were of significantly longer duration in females
than in males in both the 1995 (n = 1,064) and 1997 (n = 910) data collections.
After covariate adjustment, female sex remained associated with significantly
longer duration ICU LOS and total postoperative LOS in both the 1995 (female:male
ratios 1.30:1 and 1.13:1, respectively) and the 1997 (female:male ratios 1.19:1
and 1.12:1, respectively) data sets. After covariate adjustment, duration of
intubation and ICU LOS after extubation were of significantly longer duration in
women than men in 1995 (female:male ratios 1.22:1 and 1.39:1, respectively), but
the differences were not significant in 1997. CONCLUSIONS: Even in the context of
accelerated recovery programs, these analyses show that female sex has powerful
associations with increased LOS intervals for coronary artery bypass grafting
surgery, even after adjustment for preoperative covariates. These effects could
result from differences in the ways in which men and women respond to coronary
artery disease, anesthesia, and coronary artery bypass grafting surgery, or to
bias on the part of healthcare workers.
PMID- 10691229
TI - Risk of surgery and anesthesia for ischemic stroke.
AB - BACKGROUND: The goal of this study was to determine if the combination of surgery
and anesthesia is an independent risk factor for the development of incident
(first-time) ischemic stroke. METHODS: All residents of Rochester, MN, with
incident ischemic stroke from 1960 through 1984 (1,455 cases and 1,455 age- and
gender-matched controls) were used to identify risk factors associated with
ischemic stroke. Cases and controls undergoing surgery involving general
anesthesia or central neuroaxis blockade before their stroke/index date of
diagnosis were identified. A conditional logistic regression model was used to
estimate the odds ratio of surgery and anesthesia for ischemic stroke while
adjusting for other known risk factors. RESULTS: There were 59 cases and 17
controls having surgery within 30 days before their stroke/index date. After
adjusting for previously identified risk factors, surgery within 30 days before
the stroke/index date (perioperative period) was found to be an independent risk
factor for stroke (P<0.001; odds ratio, 3.9; 95% confidence interval, 2.1-7.4).
In an analysis that excluded matched pairs where the case and/or control
underwent surgery considered "high risk" for stroke (cardiac, neurologic, or
vascular procedures), "non-high-risk surgery" was also found to be an independent
risk factor for perioperative stroke (P = 0.002; odds ratio, 2.9; 95% confidence
interval, 1.5-5.7). CONCLUSION: Our results suggest that there is an increased
risk of ischemic stroke in the 30 days after surgery and anesthesia. This risk
remains elevated even after excluding surgeries (cardiac, neurologic, and
vascular surgeries) considered to be high risk for ischemic stroke.
PMID- 10691230
TI - Comparison of intravenous or epidural patient-controlled analgesia in the elderly
after major abdominal surgery.
AB - BACKGROUND: Patient-controlled analgesia (PCA) with intravenous morphine and
patient-controlled epidural analgesia (PCEA), using an opioid either alone or in
combination with a local anesthetic, are two major advances in the management of
pain after major surgery. However, these techniques have been evaluated poorly in
elderly people. This prospective, randomized study compared the effectiveness on
postoperative pain and safety of PCEA and PCA after major abdominal surgery in
the elderly patient. METHODS: Seventy patients older than 70 yr of age and
undergoing major abdominal surgery were assigned randomly to receive either
combined epidural analgesia and general anesthesia followed by postoperative
PCEA, using a mixture of 0.125% bupivacaine and sufentanil (PCEA group), or
general anesthesia followed by PCA with intravenous morphine (PCA group). Pain
intensity was tested three times daily using a visual analog scale. Postoperative
evaluation included mental status, cardiorespiratory and gastrointestinal
functions, and patient satisfaction scores. RESULTS: Pain relief was better at
rest (P = 0.001) and after coughing (P = 0.002) in the PCEA group during the 5
postoperative days. Satisfaction scores were better in the PCEA group. Although
incidence of delirium was comparable in the PCA and PCEA groups (24% vs. 26%,
respectively), mental status was improved on the fourth and fifth postoperative
days in the PCEA group. The PCEA group recovered bowel function more quickly than
did the PCA group. Cardiopulmonary complications were similar in the two groups.
CONCLUSION: After major abdominal surgery in the elderly patient, patient
controlled analgesia, regardless of the route (epidural or parenteral), is
effective. The epidural route using local anesthetics and an opioid provides
better pain relief and improves mental status and bowel activity.
PMID- 10691231
TI - Hypoxic brain tissue following subarachnoid hemorrhage.
AB - BACKGROUND: Subarachnoid hemorrhage can lead to cerebral ischemia and
irreversible brain injury. The purpose of this study was to determine whether
subarachnoid hemorrhage produces changes in brain tissue oxygen pressure, carbon
dioxide pressure, or pH during surgery for cerebral aneurysm clipping. METHODS:
After institutional review board approval and patient consent, 30 patients
undergoing craniotomy for cerebral aneurysm clipping were studied, 15 without and
15 with subarachnoid hemorrhage. Patients with subarachnoid hemorrhage were
prospectively separated into groups with modest (Fisher grade 1 or 2; n = 8) and
severe bleeds (Fisher grade 3; n = 7). After a craniotomy, a probe was inserted
into cortex tissue supplied by the artery associated with the aneurysm. Baseline
measures were made in the presence of a 4% end-tidal desflurane level. The end
tidal desflurane level was increased to 9% before clipping of the aneurysm, and a
second tissue measurement was made. RESULTS: The median time of surgery after
subarachnoid hemorrhage was 2 days, ranging from 1 to 13 days. During baseline
anesthesia, brain tissue oxygen pressure was 17+/-9 mm Hg (mean +/- SD) in
control patients, 13+/-9 mm Hg in those with Fisher grade 1 or 2 hemorrhage, and
7+/-6 mm Hg in those with Fisher grade 3 hemorrhage (P<0.05 compared with
control). Brain tissue pH was 7.10+/-0.10 in control patients, 7.14+/-0.13 in
those with Fisher grade 1 or 2 hemorrhage, and 6.95+/-0.18 in those with with
Fisher grade 3 hemorrhage (P<0.05). At a 9% end-tidal desflurane level, brain
tissue oxygen pressure increased to 19+/-9 mm Hg and brain tissue pH increased to
7.11+/-0.11 in patients with Fisher grade 3 hemorrhage (P<0.05 for both
increases). CONCLUSION: These results show that subarachnoid hemorrhage can
significantly decrease brain tissue oxygen pressure and pH related to the
severity of the bleed. Increasing the desflurane concentration to 9% increased
brain tissue oxygen pressure in all patients and brain tissue pH in patients with
subarachnoid hemorrhage with baseline acidosis.
PMID- 10691232
TI - Efficacy of two methods for reducing postbypass afterdrop.
AB - BACKGROUND: Afterdrop, defined as the precipitous reduction in core temperature
after cardiopulmonary bypass, results from redistribution of body heat to
inadequately warmed peripheral tissues. The authors tested two methods of
ameliorating afterdrop: (1) forced-air warming of peripheral tissues and (2)
nitroprusside-induced vasodilation. METHODS: Patients were cooled during
cardiopulmonary bypass to approximately 32 degrees C and subsequently rewarmed to
a nasopharyngeal temperature near 37 degrees C and a rectal temperature near 36
degrees C. Patients in the forced-air protocol (n = 20) were assigned randomly to
forced-air warming or passive insulation on the legs. Active heating started with
rewarming while undergoing bypass and was continued for the remainder of surgery.
Patients in the nitroprusside protocol (n = 30) were assigned randomly to either
a control group or sodium nitroprusside administration. Pump flow during
rewarming was maintained at 2.5 l x m(-2) x min(-1) in the control patients and
at 3.0 l x m(-2) x min(-1) in those assigned to sodium nitroprusside. Sodium
nitroprusside was titrated to maintain a mean arterial pressure near 60 mm Hg. In
all cases, a nasopharyngeal probe evaluated core (trunk and head) temperature and
heat content. Peripheral compartment (arm and leg) temperature and heat content
were estimated using fourth-order regressions and integration over volume from 18
intramuscular needle thermocouples, nine skin temperatures, and "deep" hand and
foot temperature. RESULTS: In patients warmed with forced air, peripheral tissue
temperature was higher at the end of warming and remained higher until the end of
surgery. The core temperature afterdrop was reduced from 1.2+/-0.2 degrees C to
0.5+/-0.2 degrees C by forced-air warming. The duration of afterdrop also was
reduced, from 50+/-11 to 27+/-14 min. In the nitroprusside group, a rectal
temperature of 36 degrees C was reached after 30+/-7 min of rewarming. This was
only slightly faster than the 40+/-13 min necessary in the control group. The
afterdrop was 0.8+/-0.3 degrees C with nitroprusside and lasted 34+/-10 min which
was similar to the 1.1+/-0.3 degrees C afterdrop that lasted 44+/-13 min in the
control group. CONCLUSIONS: Cutaneous warming reduced the core temperature
afterdrop by 60%. However, heat-balance data indicate that this reduction
resulted primarily because forced-air heating prevented the typical decrease in
body heat content after discontinuation of bypass, rather than by reducing
redistribution. Nitroprusside administration slightly increased peripheral tissue
temperature and heat content at the end of rewarming. However, the core-to
peripheral temperature gradient was low in both groups. Consequently, there was
little redistribution in either case.
PMID- 10691233
TI - Relative importance of flow versus pressure in splanchnic perfusion during
cardiopulmonary bypass in rabbits.
AB - BACKGROUND: Decreased gastrointestinal perfusion has been reported during
cardiopulmonary bypass (CPB). Conflicting results have been published concerning
thresholds of pressure and flow to avoid splanchnic ischemia during CPB. This
study compared splanchnic perfusion during independent and randomized variations
of CPB pump flow or arterial pressure. METHODS: Ten rabbits were studied during
mild hypothermic (36 degrees C) nonpulsatile CPB using neonatal oxygenators.
Simultaneous measurements of tissue blood flow in four different splanchnic areas
(gastric, jejunum, ileum, and liver) were performed by laser Doppler flowmetry
(LDF) before CPB (T0) and during a 4-step factorial experimental block design.
Pressure and flow were alternatively high or low in random order. RESULTS: Laser
Doppler flowmetry was significantly lower than pre-CPB value but was better
preserved (analysis of covariance) in all organs, except liver, when CPB flow was
high, whatever the pressure. Splanchnic LDF values in the low- versus high-flow
groups expressed as perfusion unit were (mean +/- SD): stomach, 94+/-66 versus
137+/-75; jejunum, 118+/-78 versus 172+/-75; ileum, 95+/-72 versus 146+/-83; and
liver, 79+/-72 versus 108+/-118. No significant difference of LDF was observed
between the high- and low-pressure groups, whatever the flow, except for liver:
stomach, 115+/-64 versus 117+/-83; jejunum, 141+/-80 versus 148+/-83; ileum,
127+/-87 versus 114+/-76; liver, 114+/-88 versus 73+/-70. CONCLUSION: Prevention
of splanchnic ischemia during CPB should focus on preservation of high CPB blood
flow rather than on high pressure.
PMID- 10691234
TI - Long-lasting hyperalgesia induced by fentanyl in rats: preventive effect of
ketamine.
AB - BACKGROUND: It has been reported that mu-opioid receptor activation leads to a
sustained increase in glutamate synaptic effectiveness at the N-methyl-D
aspartate (NMDA) receptor level, a system associated with central
hypersensitivity to pain. One hypothesis is that postoperative pain may result
partly from the activation of NMDA pain facilitatory processes induced by opiate
treatment per se. The authors tested here the effectiveness of the opiate
analgesic fentanyl for eliciting a delayed enhancement in pain sensitivity.
METHODS: The consequences of four bolus injections (every 15 min) of fentanyl (20
100 microg/kg per injection, subcutaneously) on immediate (for several hours) and
long-term (for several days) sensitivity to nociceptive stimuli in the rat (paw
pressure vocalization test) were evaluated. The effects of the combination of the
NMDA-receptor antagonist ketamine (10 mg/kg, subcutaneously) with fentanyl also
were assessed. RESULTS: Fentanyl administration exhibited a biphasic time
dependent effect: first, an early response (for 2-5 h) associated with a marked
increase in nociceptive threshold (analgesia), and second, a later response
associated with sustained lowering of the nociceptive threshold (5 days for the
longest effect) below the basal value (30% of decrease for the maximal effect)
indicative of hyperalgesia. The higher the fentanyl dose used, the more
pronounced was the fentanyl-induced hyperalgesia. Ketamine pretreatment, which
had no analgesic effect on its own, enhanced the earlier response (analgesia) and
prevented the development of long-lasting hyperalgesia. CONCLUSIONS: Fentanyl
activates NMDA pain facilitatory processes, which oppose analgesia and lead to
long-lasting enhancement in pain sensitivity.
PMID- 10691235
TI - Norepinephrine facilitates inhibitory transmission in substantia gelatinosa of
adult rat spinal cord (part 1): effects on axon terminals of GABAergic and
glycinergic neurons.
AB - BACKGROUND: The activation of descending norepinephrine-containing fibers from
the brain stem inhibits nociceptive transmission at the spinal level. How these
descending noradrenergic pathways exert the analgesic effect is not understood
fully. Membrane hyperpolarization of substantia gelatinosa (Rexed lamina II)
neurons by the activation of alpha2 receptors may account for depression of pain
transmission. In addition, it is possible that norepinephrine affects transmitter
release in the substantia gelatinosa. METHODS: Adult male Sprague-Dawley rats (9
10 weeks of age, 250-300 g) were used in this study. Transverse spinal cord
slices were cut from the isolated lumbar cord. The blind whole-cell patch-clamp
technique was used to record from neurons. The effects of norepinephrine on the
frequency and amplitude of miniature excitatory and inhibitory postsynaptic
currents were evaluated. RESULTS: In the majority of substantia gelatinosa
neurons tested, norepinephrine (10-100 microM) dose-dependently increased the
frequency of gamma-aminobutyric acid (GABA)ergic and glycinergic miniature
inhibitory postsynaptic currents; miniature excitatory postsynaptic currents were
unaffected. This augmentation was mimicked by an alpha1-receptor agonist,
phenylephrine (10-60 microM), and inhibited by alpha1-receptor antagonists
prazosin (0.5 microM) and 2-(2,6-dimethoxyphenoxyethyl) amino-methyl-1,4
benzodioxane (0.5 microM). Neither postsynaptic responsiveness to exogenously
applied GABA and glycine nor the kinetics of GABAergic and glycinergic inhibitory
postsynaptic currents were affected by norepinephrine. CONCLUSION: These results
suggest that norepinephrine enhances inhibitory synaptic transmission in the
substantia gelatinosa through activation of presynaptic alpha1 receptors, thus
providing a mechanism underlying the clinical use of alpha1 agonists with local
anesthetics in spinal anesthesia.
PMID- 10691236
TI - Norepinephrine facilitates inhibitory transmission in substantia gelatinosa of
adult rat spinal cord (part 2): effects on somatodendritic sites of GABAergic
neurons.
AB - BACKGROUND: It has been reported previously that norepinephrine, when applied to
the spinal cord dorsal horn, excites a subpopulation of dorsal horn neurons,
presumably inhibitory interneurons. In the current study, the authors tested
whether norepinephrine could activate inhibitory interneurons, specifically those
that are "GABAergic." METHODS: A transverse slice was obtained from a segment of
the lumbar spinal cord isolated from adult male Sprague-Dawley rats. Whole-cell
patch-clamp recordings were made from substantia gelatinosa neurons using the
blind patch-clamp technique. The effects of norepinephrine on spontaneous
GABAergic inhibitory postsynaptic currents were studied. RESULTS: In the majority
of substantia gelatinosa neurons tested, norepinephrine (10-60 microM)
significantly increased both the frequency and the amplitude of GABAergic
inhibitory postsynaptic currents. These increases were blocked by tetrodotoxin (1
microM). The effects of norepinephrine were mimicked by the alpha1-receptor
agonist phenylephrine (10-80 microM) and inhibited by the alpha1-receptor
antagonist WB-4101 (0.5 microM). Primary-afferent-evoked polysynaptic excitatory
postsynaptic potentials or excitatory postsynaptic currents in wide-dynamic-range
neurons of the deep dorsal horn were also attenuated by phenylephrine (40
microM). CONCLUSION: The observations suggest that GABAergic interneurons possess
somatodendritic alpha1 receptors, and activation of these receptors excites
inhibitory interneurons. The alpha1 actions reported herein may contribute to the
analgesic action of intrathecally administered phenylephrine.
PMID- 10691237
TI - Intrathecally administered cGMP-dependent protein kinase Ialpha inhibitor
significantly reduced the threshold for isoflurane anesthesia: implication for a
novel role of cGMP-dependent protein kinase Ialpha.
AB - BACKGROUND: Inhalational anesthetics have been shown to inhibit the nitric oxide
(NO)-cyclic guanosine monophosphate (cGMP) pathway. Previous studies indicated
that inhibition of the NO-cGMP pathway decreased the level of consciousness and
augmented anesthesia, analgesia, or sedation. The current study investigated the
possible involvement of cGMP-dependent protein kinases (PKGs) as major effectors
for the NO-cGMP pathway in the anesthetic state. METHODS: After initial baseline
determination of the minimum alveolar concentration (MAC), a selective cGMP
dependent protein kinase Ialpha inhibitor, Rp-8-p-CPT-cGMPS, or an NO donor, (NOC
12), were injected intrathecally. Ten minutes later, MAC measurement was
repeated. The rats also were evaluated for the presence of locomotor dysfunction
by intrathecal administration of Rp-8-p-CPT-cGMPS and NOC-12 in conscious rats.
RESULTS: Rp-8-p-CPT-cGMPS at 25, 50, 100, and 200 microg/10 microl produced a
significant decrease from isoflurane control MAC of -4+/-3.1%, 16+/-4.5%, 30+/
5.0%, and 21+/-2.2%, respectively, which was not accompanied by significant
changes in either blood pressure or heart rate. In contrast, NOC-12 at 100
microg/10 microl caused an increase from isoflurane control MAC of 23+/-5.8%,
which was accompanied by significant decrease in blood pressure but not in heart
rate. Rp-8-p-CPT-cGMPS (100 microg/10 microl) produced a significant reversal of
isoflurane MAC increase induced by NOC-12 (100 microg/10 microl), which was
accompanied by significant reversal of the reduction of blood pressure induced by
NOC-12. Locomotor activity was not changed. CONCLUSIONS: The results indicate
that cGMP-dependent protein kinase Ialpha inhibitor not only markedly reduces MAC
for isoflurane, but also completely blocks the NO-induced increase in isoflurane
MAC, which suggests that cGMP-dependent protein kinase Ialpha may mediate the
action for the NO-cGMP pathway in anesthetic mechanisms at the spinal cord level.
PMID- 10691238
TI - Synergistic effect between intrathecal non-NMDA antagonist and gabapentin on
allodynia induced by spinal nerve ligation in rats.
AB - BACKGROUND: Glutamate and non-N-methyl-D-aspartate (NMDA) receptors have been
implicated in the development of neuroplasticity in the spinal cord in
neuropathic pain. The spinal cord has been identified as one of the sites of the
analgesic action of gabapentin. In the current study, the authors determined the
antiallodynic effect of intrathecal 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)
in a rat model of neuropathic pain. Also tested was a hypothesis that intrathecal
injection of CNQX and gabapentin produces a synergistic effect on allodynia in
neuropathic rats. METHODS: Allodynia was produced in rats by ligation of the left
L5 and L6 spinal nerves. Allodynia was determined by application of von Frey
filaments to the left hind paw. Through an implanted intrathecal catheter, 10-100
microg gabapentin or 0.5-8 microg CNQX disodium (a water-soluble formulation of
CNQX) was injected in conscious rats. Isobolographic analysis was performed
comparing the interaction of intrathecal gabapentin and CNQX using the ED50 dose
ratio of 15:1. RESULTS: Intrathecal treatment with gabapentin or CNQX produced a
dose-dependent increase in the withdrawal threshold to mechanical stimulation.
The ED50 for gabapentin and CNQX was 45.9+/-4.65 and 3.4+/-0.22 microg,
respectively. Intrathecal injection of a combination of CNQX and gabapentin
produced a strong synergistic antiallodynic effect in neuropathic rats.
CONCLUSIONS: This study shows that intrathecal administration of CNQX exhibits an
antiallodynic effect in this rat model of neuropathic pain. Furthermore, CNQX and
gabapentin, when combined intrathecally, produce a potent synergistic
antiallodynic effect on neuropathic pain in spinal nerve-ligated rats.
PMID- 10691239
TI - Actions of midazolam on GABAergic transmission in substantia gelatinosa neurons
of adult rat spinal cord slices.
AB - BACKGROUND: Although intrathecal administration of midazolam has been found to
produce analgesia, how midazolam exerts this effect is not understood fully at
the neuronal level in the spinal cord. METHODS: The effects of midazolam on
either electrically evoked or spontaneous inhibitory transmission and on a
response to exogenous gamma-aminobutyric acid (GABA), a GABA(A)-receptor agonist,
muscimol, or glycine were evaluated in substantia gelatinosa neurons of adult rat
spinal cord slices by using the whole-cell patch-clamp technique. RESULTS: Bath
applied midazolam (1 microM) prolonged the decay phase of evoked and miniature
inhibitory postsynaptic currents (IPSCs), mediated by GABA(A) receptors, without
a change in amplitudes, while not affecting glycine receptor-mediated miniature
inhibitory postsynaptic currents in both the decay phase and the amplitude.
Either GABA- or muscimol-induced currents were enhanced in amplitude by midazolam
(0.1 microM) in a manner sensitive to a benzodiazepine receptor antagonist,
flumazenil (1 microM); glycine currents were, however, unaltered by midazolam.
CONCLUSIONS: Midazolam augmented both the duration of GABA-mediated synaptic
current and the amplitude of GABA-induced current by acting on the GABA(A)
benzodiazepine receptor in substantia gelatinosa neurons; this would increase the
inhibitory GABAergic transmission. This may be a possible mechanism for
antinociception by midazolam.
PMID- 10691240
TI - Xenon does not alter cardiac function or major cation currents in isolated guinea
pig hearts or myocytes.
AB - BACKGROUND: The noble gas xenon (Xe) has been used as an inhalational anesthetic
agent in clinical trials with little or no physiologic side effects. Like nitrous
oxide, Xe is believed to exert minimal unwanted cardiovascular effects, and like
nitrous oxide, the vapor concentration to achieve 1 minimum alveolar
concentration (MAC) for Xe in humans is high, i.e., 70-80%. In the current study,
concentrations of up to 80% Xe were examined for possible myocardial effects in
isolated, erythrocyte-perfused guinea pig hearts and for possible effects on
altering major cation currents in isolated guinea pig cardiomyocytes. METHODS:
Isolated guinea pigs hearts were perfused at 70 mm Hg via the Langendorff
technique initially with a salt solution at 37 degrees C. Hearts were then
perfused with fresh filtered (40-microm pore) and washed canine erythrocytes
diluted in the salt solution equilibrated with 20% O2 in nitrogen (control), with
20% O2, 40% Xe, and 40% N2, (0.5 MAC), or with 20% O2 and 80% Xe (1 MAC),
respectively. Hearts were perfused with 80% Xe for 15 min, and bradykinin was
injected into the blood perfusate to test endothelium-dependent vasodilatory
responses. Using the whole-cell patch-clamp technique, 80% Xe was tested for
effects on the cardiac ion currents, the Na+, the L-type Ca2+, and the inward
rectifier K+ channel, in guinea pig myocytes suffused with a salt solution
equilibrated with the same combinations of Xe, oxygen, and nitrogen as above.
RESULTS: In isolated hearts, heart rate, atrioventricular conduction time, left
ventricular pressure, coronary flow, oxygen extraction, oxygen consumption,
cardiac efficiency, and flow responses to bradykinin were not significantly
(repeated measures analysis of variance, P>0.05) altered by 40% or 80% Xe
compared with controls. In isolated cardiomyocytes, the amplitudes of the Na+,
the L-type Ca2+, and the inward-rectifier K+ channel over a range of voltages
also were not altered by 80% Xe compared with controls. CONCLUSIONS: Unlike
hydrocarbon-based gaseous anesthetics, Xe does not significantly alter any
measured electrical, mechanical, or metabolic factors, or the nitric oxide
dependent flow response in isolated hearts, at least partly because Xe does not
alter the major cation currents as shown here for cardiac myocytes. The authors'
results indicate that Xe, at approximately 1 MAC for humans, has no
physiologically important effects on the guinea pig heart.
PMID- 10691241
TI - Bupivacaine inhibits acylcarnitine exchange in cardiac mitochondria.
AB - BACKGROUND: The authors previously reported that secondary carnitine deficiency
may sensitize the heart to bupivacaine-induced arrhythmias. In this study, the
authors tested whether bupivacaine inhibits carnitine metabolism in cardiac
mitochondria. METHODS: Rat cardiac interfibrillar mitochondria were prepared
using a differential centrifugation technique. Rates of adenosine diphosphate
stimulated (state III) and adenosine diphosphate-limited (state IV) oxygen
consumption were measured using a Clark electrode, using lipid or nonlipid
substrates with varying concentrations of a local anesthetic. RESULTS: State III
respiration supported by the nonlipid substrate pyruvate (plus malate) is
minimally affected by bupivacaine concentrations up to 2 mM. Lower concentrations
of bupivacaine inhibited respiration when the available substrates were
palmitoylcarnitine or acetylcarnitine; bupivacaine concentration causing 50%
reduction in respiration (IC50 +/- SD) was 0.78+/-0.17 mM and 0.37+/-0.03 mM for
palmitoylcarnitine and acetylcarnitine, respectively. Respiration was equally
inhibited by bupivacaine when the substrates were palmitoylcarnitine alone, or
palmitoyl-CoA plus carnitine. Bupivacaine (IC50 = 0.26+/-0.06 mM) and etidocaine
(IC50 = 0.30+/-0.12 mM) inhibit carnitine-stimulated pyruvate oxidation
similarly, whereas the lidocaine IC50 is greater by a factor of roughly 5, (IC50
= 1.4+/-0.26 mM), and ropivacaine is intermediate, IC50 = 0.5+/-0.28 mM.
CONCLUSIONS: Bupivacaine inhibits mitochondrial state III respiration when
acylcarnitines are the available substrate. The substrate specificity of this
effect rules out bupivacaine inhibition of carnitine palmitoyl transferases I and
II, carnitine acetyltransferase, and fatty acid beta-oxidation. The authors
hypothesize that differential inhibition of carnitine-stimulated pyruvate
oxidation by various local anesthetics supports the clinical relevance of
inhibition of carnitine-acylcarnitine translocase by local anesthetics with a
cardiotoxic profile.
PMID- 10691242
TI - Differential effects of anesthetic and nonanesthetic cyclobutanes on neuronal
voltage-gated sodium channels.
AB - BACKGROUND: Despite their key role in the generation and propagation of action
potentials in excitable cells, voltage-gated sodium (Na+) channels have been
considered to be insensitive to general anesthetics. The authors tested the
sensitivity of neuronal Na+ channels to structurally similar anesthetic (1-chloro
1,2,2-trifluorocyclobutane; F3) and nonanesthetic (1,2
dichlorohexafluorocyclobutane; F6) polyhalogenated cyclobutanes by neurochemical
and electrophysiologic methods. METHODS: Synaptosomes (pinched-off nerve
terminals) from adult rat cerebral cortex were used to determine the effects of
F3 and F6 on 4-aminopyridine- or veratridine-evoked (Na+ channel-dependent)
glutamate release (using an enzyme-coupled spectrofluorimetric assay) and
increases in intracellular Ca2+ ([Ca2+]i) (using ion-specific
spectrofluorimetry). Effects of F3 and F6 on Na+ currents were evaluated directly
in rat lumbar dorsal root ganglion neurons by whole-cell patch-clamp recording.
RESULTS: F3 inhibited glutamate release evoked by 4-aminopyridine (inhibitory
concentration of 50% [IC50] = 0.77 mM [approximately 0.8 minimum alveolar
concentration (MAC)] or veratridine (IC50 = 0.42 mM [approximately 0.4 MAC]), and
veratridine-evoked increases in [Ca2+]i (IC50 = 0.5 mM [approximately 0.5 MAC])
in synaptosomes; F6 had no significant effects up to 0.05 mM (approximately twice
the predicted MAC). F3 caused reversible membrane potential-independent
inhibition of peak Na+ currents (70+/-9% block at 0.6 mM [approximately 0.6
MAC]), and a hyperpolarizing shift in the voltage-dependence of steady state
inactivation in dorsal root ganglion neurons (-21+/-9.3 mV at 0.6 mM). F6
inhibited peak Na+ currents to a lesser extent (16+/-2% block at 0.018 mM
[predicted MAC]) and had minimal effects on steady state inactivation.
CONCLUSIONS: The anesthetic cyclobutane F3 significantly inhibited Na+ channel
mediated glutamate release and increases in [Ca2+]i. In contrast, the
nonanesthetic cyclobutane F6 had no significant effects at predicted anesthetic
concentrations. F3 inhibited dorsal root ganglion neuron Na+ channels with a
potency and by mechanisms similar to those of conventional volatile anesthetics;
F6 was less effective and did not produce voltage-dependent block. This
concordance between anesthetic activity and Na+ channel inhibition supports a
role for presynaptic Na+ channels as targets for general anesthetic effects and
suggests that shifting the voltage-dependence of Na+ channel inactivation is an
important property of volatile anesthetic compounds.
PMID- 10691243
TI - Propofol-induced modifications of cardiomyocyte calcium transient and
sarcoplasmic reticulum function in rats.
AB - BACKGROUND: Propofol is considered to be an anesthetic agent with few or no
negative inotropic effects. This study evaluated a possible direct depressant
effect of propofol on sarcoplasmic reticulum Ca2+ accumulation and
cardiomyocytes. METHODS: The effects of propofol on intracellular Ca2+ transients
were evaluated in isolated rat cardiomyocytes using a microfluorometric technique
with Indo-1. Sarcoplasmic reticulum function was also assessed by measuring the
oxalate-stimulated Ca2+ uptake from homogenates of rat ventricles. RESULTS: The
Ca2+ uptake capacity of the sarcoplasmic reticulum was decreased by propofol (10(
4) M). Large concentrations of propofol decreased the rate of decrease of the
intracellular Ca2+ transient, which resulted in an increase of diastolic Ca2+
when the diastolic interval was decreased. The increased diastolic Ca2+ also
resulted in a decrease in Ca2+ transient. This effect appeared for lower doses
(10(-5) M) after a short diastolic pause rather than after a long (2- to 3-min)
rest (appearing at 10(-4) M). CONCLUSIONS: For doses more than 10(-5) M, propofol
induces a Ca2+ uptake capacity impairment of the sarcoplasmic reticulum. This is
probably responsible for a slowing of the decrease of the Ca2+ transient, which
in turn increases the diastolic Ca2+ for high heart rate. These diastolic
modifications may participate in the slight negative inotropic effect of the
drug.
PMID- 10691244
TI - Primate pleuroesophageal tissue barrier frequency response and esophageal
pressure waveform bandwidth in health and acute lung injury.
AB - BACKGROUND: Dynamic intraesophageal pressure (Pes) is used to estimate
intrapleural pressure (Ppl) to calculate lung compliance and resistance. This
study investigated the nonhuman primate Ppl-Pes tissue barrier frequency response
and the dynamic response requirements of Pes manometers. METHODS: In healthy
monkeys and monkeys with acute lung injury undergoing ventilation, simultaneous
Ppl and Pes were measured directly to determine the Ppl-Pes tissue barrier
amplitude frequency response, using the swept-sine wave technique. The bandwidths
of physiologic Pes waveforms acquired during conventional mechanical ventilation
were calculated using digital low-pass signal filtering. RESULTS: The Ppl-Pes
tissue barrier is amplitude-uniform within the bandwidth of conventional Pes
waveforms in healthy and acute lung injury lungs, and does not significantly
attenuate Ppl-Pes signal transmission between 1 and 40 Hz. At Pes frequencies
higher than conventional clinical regions of interest the Ppl-Pes barrier
resonates significantly, is pressure amplitude dependent at low-pressure offsets,
and is significantly altered by acute lung injury. Allowing for 5% or less Pes
waveform error, the maximum Pes bandwidths during conventional ventilation were
1.9 Hz and 3.4 Hz for physiologic and extreme-case waveforms in healthy lungs and
4.6 Hz and 8.5 Hz during acute lung injury. CONCLUSIONS: In monkeys, the Ppl-Pes
tissue barrier has a frequency response suitable for Ppl estimation during low
frequency mechanical ventilation, and Pes manometers should have a minimum
uniform frequency response up to 8.5 Hz. However, the Ppl-Pes tissue barrier
adversely affects the accurate estimation of dynamic Ppl at high frequencies,
with varied airway pressure amplitudes and offsets, such as the Ppl encountered
during high-frequency oscillatory ventilation.
PMID- 10691245
TI - Isoflurane action in the spinal cord blunts electroencephalographic and thalamic
reticular formation responses to noxious stimulation in goats.
AB - BACKGROUND: Isoflurane depresses the electroencephalographic (EEG) activity and
exerts part of its anesthetic effect in the spinal cord. The authors hypothesized
that isoflurane would indirectly depress the EEG and subcortical response to
noxious stimulation in part by a spinal cord action. METHODS: Depth electrodes
were inserted into the midbrain reticular formation (MRF) and thalamus of six of
seven isoflurane-anesthetized goats, and needle-electrodes were placed into the
skull periosteum. In five of seven goats, an MRF microelectrode recorded single
unit activity. The jugular veins and carotid arteries were isolated to permit
cranial bypass and differential isoflurane delivery. A noxious mechanical
stimulus (1 min) was applied to a forelimb dewclaw at each of two cranial-torso
isoflurane combinations: 1.1+/-0.3%-1.2+/-0.3% and 1.1+/-0.3-0.3+/-0.1% (mean +/-
SD). RESULTS: When cranial-torso isoflurane was 1.1-1.2%, the noxious stimulus
did not alter the EEG. When torso isoflurane was decreased to 0.3%, the noxious
stimulus activated the MRF, thalamic, and bifrontal-hemispheric regions
(decreased high-amplitude, low-frequency power). For all channels combined, total
(-33+/-15%), delta(-51+/-22%), theta (-33+/-19%), and alpha (-26+/-16%) power
decreased after the noxious stimulus (P<0.05); beta power was unchanged. The MRF
unit responses to the noxious stimulus were significantly higher when the spinal
cord isoflurane concentration was 0.3% (1,286+/-1,317 impulses/min) as compared
with 1.2% (489+/-437 impulses/min, P<0.05). CONCLUSIONS: Isoflurane blunted the
EEG and MRF-thalamic response to noxious stimulation in part via an action in the
spinal cord.
PMID- 10691246
TI - Midazolam selectively potentiates the A(2A) - but not A1- receptor--mediated
effects of adenosine: role of nucleoside transport inhibition and clinical
implications.
AB - BACKGROUND: Inhibition of adenosine metabolism offers a unique approach to
harness the cardioprotective properties of adenosine in a site- and event
specific manner. Benzodiazepines inhibit adenosine metabolism by blocking
nucleoside transporter. Therefore, the authors studied the binding affinities of
structurally different benzodiazepines to nucleoside transporter and
benzodiazepine-induced potentiation of A1-adenosine (negative dromotropy) and A2A
adenosine (coronary vasodilation) receptor-mediated effects. METHODS: In
membranes from porcine striatum and guinea pig ventricle, competition binding
assays to displace [3H]nitrobenzylmercaptopurine riboside ([3H]NBMPR) from
nucleoside transporter were performed using alprazolam, chlorodiazepoxide,
diazepam, flurazepam, and midazolam. The augmentation by the most potent
benzodiazepine of A1- and A2A-adenosine receptor-mediated responses, elicited by
exogenous administration of adenosine or brief periods of global hypoxia, was
subsequently studied in guinea pig Langendorff-perfused hearts. RESULTS: All
benzodiazepines completely displaced [3H]NBMPR in a concentration-dependent
manner with Hill coefficients not significantly different from unity in both
striatal and ventricular membranes. Midazolam was the most potent inhibitor of
nucleoside transporter (ventricle:pKi = 5.22+/-0.41, Ki = 6 microM). In isolated
hearts, midazolam (5, 10, 20 microM) significantly augmented coronary flow in a
concentration-dependent manner in the presence of adenosine (30 nM), an effect
reversed by ZM 241385, a selective A2A-receptor antagonist. In contrast,
midazolam did not increase the effect of adenosine (30 nM) on atrioventricular
conduction. Similarly, midazolam potentiated A2A- but not A1-receptor-mediated
effects of endogenous adenosine released during hypoxia. CONCLUSIONS:
Structurally distinct benzodiazepines inhibit nucleoside transporter to different
degrees. Midazolam selectively augments A2A- but not A1-receptor-mediated effects
of adenosine by inhibiting nucleoside transporter.
PMID- 10691247
TI - Perioperative heat balance.
AB - Hypothermia during general anesthesia develops with a characteristic three-phase
pattern. The initial rapid reduction in core temperature after induction of
anesthesia results from an internal redistribution of body heat. Redistribution
results because anesthetics inhibit the tonic vasoconstriction that normally
maintains a large core-to-peripheral temperature gradient. Core temperature then
decreases linearly at a rate determined by the difference between heat loss and
production. However, when surgical patients become sufficiently hypothermic, they
again trigger thermoregulatory vasoconstriction, which restricts core-to
peripheral flow of heat. Constraint of metabolic heat, in turn, maintains a core
temperature plateau (despite continued systemic heat loss) and eventually
reestablishes the normal core-to-peripheral temperature gradient. Together, these
mechanisms indicate that alterations in the distribution of body heat contribute
more to changes in core temperature than to systemic heat imbalance in most
patients. Just as with general anesthesia, redistribution of body heat is the
major initial cause of hypothermia in patients administered spinal or epidural
anesthesia. However, redistribution during neuraxial anesthesia is typically
restricted to the legs. Consequently, redistribution decreases core temperature
about half as much during major conduction anesthesia. As during general
anesthesia, core temperature subsequently decreases linearly at a rate determined
by the inequality between heat loss and production. The major difference,
however, is that the linear hypothermia phase is not discontinued by reemergence
of thermoregulatory vasoconstriction because constriction in the legs is blocked
peripherally. As a result, in patients undergoing large operations with neuraxial
anesthesia, there is the potential of development of serious hypothermia.
Hypothermic cardiopulmonary bypass is associated with enormous changes in body
heat content. Furthermore, rapid cooling and rewarming produces large core-to
peripheral, longitudinal, and radial tissue temperature gradients. Inadequate
rewarming of peripheral tissues typically produces a considerable core-to
peripheral gradient at the end of bypass. Subsequently, redistribution of heat
from the core to the cooler arms and legs produces an afterdrop. Afterdrop
magnitude can be reduced by prolonging rewarming, pharmacologic vasodilation, or
peripheral warming. Postoperative return to normothermia occurs when brain
anesthetic concentration decreases sufficiently to again trigger normal
thermoregulatory defenses. However, residual anesthesia and opioids given for
treatment of postoperative pain decreases the effectiveness of these responses.
Consequently, return to normothermia often needs 2-5 h, depending on the degree
of hypothermia and the age of the patient.
PMID- 10691248
TI - Awareness during anesthesia.
PMID- 10691249
TI - Erroneous conclusion from processed electroencephalogram with changing anesthetic
depth.
PMID- 10691251
TI - Angina as an indication for noncardiac surgery: the case of the coronary
subclavian steal syndrome.
PMID- 10691250
TI - Uneventful propofol anesthesia in a patient with coexisting hereditary
coproporphyria and hereditary angioneurotic edema.
PMID- 10691252
TI - Ulnar neuropathy in medical patients.
PMID- 10691253
TI - Reversible catecholamine-induced cardiomyopathy by subcutaneous injections of
epinephrine solution in an anesthetized patient.
PMID- 10691254
TI - Pharyngeal mucosa pressures.
PMID- 10691255
TI - Spinal anesthesia in preeclamptic patients--"supportive" evidence.
PMID- 10691256
TI - Saline infusion, acidosis, and the Stewart approach.
PMID- 10691257
TI - Article supports findings of previous comparison.
PMID- 10691258
TI - Avoiding latrogenic hyperchloremic acidosis--call for a new crystalloid fluid.
PMID- 10691259
TI - Dynamic response to volatile anesthetics has been examined before.
PMID- 10691260
TI - Chemical skinning artifact appears to increase sensitivity of masseter muscle to
halothane and succinylcholine.
PMID- 10691261
TI - Fatal hydrocephalus in a patient with neurofibromatosis.
PMID- 10691262
TI - Security system for transducer holders.
PMID- 10691263
TI - An easy formula to remember the laryngeal mask airway size-patient weight
relationship.
PMID- 10691264
TI - Paraplegia after cystectomy and epidural anesthesia.
PMID- 10691265
TI - Extrahepatic biliary obstruction: magnetic resonance imaging compared with
endoscopic ultrasonography.
AB - BACKGROUND AND STUDY AIMS: The aim of this study was to compare prospectively the
diagnostic efficacy of magnetic resonance (MR) imaging and endoscopic
ultrasonography (EUS) in extrahepatic biliary obstruction. PATIENTS AND METHODS:
A total of 50 patients with suspected benign or malignant extrahepatic biliary
obstruction underwent MR imaging, including MR cholangiopancreatography, and EUS,
within a median time delay of 1 day. The final diagnosis was established by
endoscopic retrograde cholangiopancreatography in 37 cases, intraoperative
cholangiography in nine cases, and clinical and biochemical follow-up in four
cases. RESULTS: In total, 33 patients had extrahepatic biliary obstruction, of
benign origin in 21 cases and of malignant origin in 12 cases, whereas 17 had no
evidence of obstruction. The sensitivity and specificity of MR imaging were 91%
and 94 %, respectively. There were one false-positive and three false-negative
results, all related to choledochal sludge. The corresponding values for EUS were
97% and 88%. There were two false-positive results and one false-negative result.
False-positive diagnoses were related to the presumed presence of biliary sludge
and choledocholithiasis, whereas the false-negative diagnosis occurred in one
patient with a final diagnosis of sludge. No significant difference in
sensitivity and specificity was observed between the two imaging methods
(P>0.05). CONCLUSION: In our study MR imaging was as accurate as EUS in the
diagnosis of extrahepatic biliary obstruction.
PMID- 10691266
TI - Analysis of the risk factors associated with endoscopic sphincterotomy
techniques: preliminary results of a prospective study, with emphasis on the
reduced risk of acute pancreatitis with low-dose anticoagulation treatment.
AB - BACKGROUND AND STUDY AIMS: The aim of the present study was to analyze the risk
factors associated with complications of endoscopic sphincterotomy (ES). PATIENTS
AND METHODS: In all consecutive endoscopic sphincterotomies carried out between
September 1994 and December 1996, the possible risk factors (12 patient-related
factors and 12 procedure-related ones), as well as the concomitant medical
treatment, indications, techniques, and success of endoscopic sphincterotomy were
evaluated prospectively. Risk factors were analyzed on an exploratory basis using
univariate methods. "Potential risk factors" (univariate, P<0.1) underwent
multivariate analysis to determine independent "risk factors" (multivariate,
P<0.05). In addition, the complication rate was calculated according to the
number of potential risk factors present. RESULTS: A total of 438 patients who
underwent ES were analyzed. Complications occurred in 7.5% (n = 33; acute
pancreatitis 4.3%, hemorrhage 2.3 %, cholangitis 0.9%, technical 0.2%).
Statistical analysis of the complications identified three independent risk
factors (coagulopathy, patient age (< or =60 years, pancreas divisum), and one
protective factor (pancreatic duct obstruction). The frequency of acute
pancreatitis was increased by two independent risk factors (pancreas divisum, ES
frequency <40 procedures/year) and was reduced if low-dose anticoagulation
(unfractionated heparin or low molecular weight heparin) was administered (0.9%,
one of 115 vs. 5.8%, 18 of 313; P<0.05). The effect of anticoagulation was not
confounded by the presence or absence of other potential risk factors for acute
pancreatitis. Neither the risk nor the severity of hemorrhage were increased by
low-dose anticoagulation. Due to the low number of events, only potential risk
factors for hemorrhage were identified (coagulopathy, intensive-care treatment).
The overall complication rate and the incidence of pancreatitis and hemorrhage
increased significantly depending on the number of simultaneous potential risk
factors present (P<0.0001). CONCLUSIONS: Patients at risk for complications after
endoscopic sphincterotomy can be identified by risk factor analysis. These data
suggest the hypothesis that low-dose anticoagulation prior to endoscopic
sphincterotomy reduces the risk of acute pancreatitis after sphincterotomy.
PMID- 10691267
TI - Video manometry of the sphincter of Oddi: a new aid for interpreting manometric
tracings and excluding manometric artefacts.
AB - BACKGROUND AND STUDY AIMS: Endoscopic sphincter of Oddi manometry (ESOM) allows
direct assessment of motor function in the sphincter of Oddi. However, variations
in examination conditions and duodenal motility may have a critical effect on the
results of ESOM. The aim of the present study was to develop a new method
sphincter of Oddi video manometry-based on simultaneous ESOM and real-time
endoscopic image analysis, and to investigate the usefulness of video manometry
for detecting manometric artefacts during ESOM. PATIENTS AND METHODS: Seven
consecutive patients who had undergone cholecystectomy and were referred with a
suspicion of sphincter of Oddi dysfunction were investigated. Sphincter of Oddi
pressure and endoscopic images (20 frames/s) were recorded simultaneously on a
Synectics PC Polygraf computer system with a time-correlated basis, and then
compared. RESULTS: On ESOM, 69 sphincter of Oddi phasic contractions were
identified, with an average amplitude of 153.9+/-85.0 mm Hg and a duration of
7.9+/-1.2 seconds. Visual analysis of the real-time endoscopic images, replayed
in cine loop by the computer, revealed 236 separate duodenal contractions, with
an average frequency of 3.5+/-2.4/min (range: 1-12/min). On the ESOM tracing, 78%
of the duodenal contractions had a corresponding pressure wave with an average
duration of 2.8+/-0.4 seconds and an amplitude of 71.9+/-16.7 mm Hg. Other
artefacts on the ESOM tracings, such as catheter movements, pseudocontractions,
hyperventilation, or retching, were also easily recognized using simultaneous
ESOM and real-time endoscopic image analysis. CONCLUSIONS: Video manometry of the
sphincter of Oddi is a promising new method for improving the analysis and
documentation of ESOM tracings. It has several advantages over the conventional
technique, allowing visual detection of duodenal activity and enabling enhanced
recognition of other manometric artefacts.
PMID- 10691268
TI - Extension of squamous epithelium into the proximal stomach: a newly recognized
mucosal abnormality.
AB - BACKGROUND AND STUDY AIMS: The presence of squamous epithelium in the stomach has
been rarely noted in the past with only sporadic case reports of squamous cell
carcinoma of the stomach and a variety of other pathological processes. We report
the documentation, over a period of 9 months, of squamous epithelium extending
beyond the esophagogastric junction and into the proximal stomach in 16 patients
who underwent upper endoscopy. PATIENTS AND METHODS: This newly recognized
mucosal abnormality was systematically identified by both antegrade and
retrograde views of the esophagogastric junction during routine upper endoscopy.
Other associated mucosal abnormalities were also evaluated (Barrett's esophagus,
erosive esophagitis, etc.). Biopsies were obtained from the distal esophagus,
cardia, antrum and the squamous extension. Additionally, all patients underwent a
detailed interview. RESULTS: Of the patients, 14 were Caucasian and two Hispanic;
all were males, with a mean age 61.2+/-4.2. Indications for upper endoscopy
included dysphagia, Barrett's esophagus surveillance, failure of antireflux
treatment and anemia. Heartburn was reported by 12 patients (75%). None of the
patients reported a history of corrosive injury, foreign body ingestion or
surgery. A total of 12 patients had a solitary tongue of squamous cell extension,
three had two tongues and in addition, two had squamous islands. Hiatal hernia
was present in all patients, Barrett's esophagus in six (37.5 %), and esophageal
stricture in four. CONCLUSION: Squamous cell extension into the proximal stomach
is a newly recognized mucosal abnormality with presently unknown clinical
significance. This mucosal abnormality may represent an esophageal mucosal
response to proximal gastric injury.
PMID- 10691269
TI - Cardiopulmonary complications during gastroscopy in patients with chronic
respiratory failure undergoing long-term home oxygen therapy.
AB - BACKGROUND AND STUDY AIMS: Gastric ulcer and hemorrhage are major complications
in patients with chronic respiratory failure, but upper GI endoscopy tends to be
avoided because of possible cardiopulmonary events. This study was designed to
evaluate hypoxemia and subsequent cardiac complications during gastroscopic
procedures in patients with chronic respiratory failure undergoing long-term home
oxygen therapy (LHOT). PATIENTS AND METHODS: Gastroscopy was carried out in 10
patients undergoing LHOT and 10 age-matched control subjects without pulmonary
diseases. Oxygen saturation and cardiac arrhythmias before and during gastroscopy
were monitored. Patients were given 10 mg intramuscular scopolamine butylbromide
and local anesthesia using 100-300 mg lidocaine gel 15 minutes before the
procedure. Each patient continued to receive oxygen via a nasal cannula in the
same dosage as their daily use. RESULTS: Decrease in oxygen saturation during
endoscopic procedure was significantly greater in patients undergoing LHOT (from
95.9+/-0.9 to 93.4+/-1.7%) compared with control subjects (from 96.7+/-0.4 to
96.2+/-0.4%). There was a significant correlation between the degree of hypoxemia
and the oxygen dosage required for their daily treatment in the patients (r =
0.727, P<0.02). CONCLUSIONS: These results indicate that the degree of
respiratory failure influences the degree of decrease in oxygen saturation during
gastroscopy. It is suggested that use of the nasal route for oxygen supply may be
one of the major causes of the hypoxemia.
PMID- 10691270
TI - A blinded, randomized comparison of a novel, low-dose, triple regimen with fleet
phospho-soda: a study of colon cleanliness, speed and success of colonoscopy.
AB - BACKGROUND AND STUDY AIMS: A clean colon is essential for an efficient
examination. The aim of this study was to compare a novel low-dose, low volume
triple regimen with Fleet Phospho-soda. METHODS: A blinded, experienced
colonoscopist examined 132 consecutive patients randomly allocated to receive
either a triple regimen consisting of senna syrup (sennoside B), Picolax (sodium
picosulphate), and Klean Prep (polyethylene glycol 3350), or Fleet Phospho-soda
(sodium dihydrogen phosphate and disodium phosphate dodecahydrate). The
colonoscopist recorded cleanliness according to a scoring system (1-very clean to
4-solid stools), and time taken to reach the caecum. RESULTS: In the triple
regimen group (n = 81), 73% scored 1 or 2 compared with 57% in the Fleet Phospho
soda group (n = 51, p = 0.037 Mann-Whitney U-test). Examination to caecum was
achieved in 95% of the triple regimen group and 89% of the Fleet Phospho-soda
group. Among those examined as far as the caecum, the time to reach the caecum
was 11 minutes (range 5-50) in the triple regimen group compared with 16 minutes
(range 5-65) in the Fleet Phospho-soda group (p = 0.08, Mann-Whitney U-test).
Patient tolerability was not assessed in this study. CONCLUSIONS: This novel
triple regimen produces a cleaner colon than Fleet Phospho-soda, is associated
with a trend towards a quicker and more efficient colonic examination, and is
also 30% cheaper per patient.
PMID- 10691271
TI - Does hyperbaric oxygen enhance the effect of photodynamic therapy in patients
with advanced esophageal carcinoma? A clinical pilot study.
AB - BACKGROUND AND STUDY AIMS: Experimental studies have shown that the cytotoxicity
of porphyrins and related substances is mediated mainly by singlet oxygen and
that hypoxic cells are less affected by porphyrins and light. In a clinical pilot
study we assessed the use of photodynamic therapy (PDT) under hyperbaric oxygen
(HBO), compared with PDT under normobaric conditions, in patients with advanced
esophageal carcinoma. PATIENTS AND METHODS: After diagnostic work-up and staging,
photosensitization in all patients was carried out using hematoporphyrine
derivate (HpD) (2 mg/kg bodyweight 48 hours prior to PDT). We then applied light
at 630 nm (KTP-Nd: YAG laser with DYE box) at dose of 300 J/cm, delivered by a
fiber with a radial light-diffusing cylinder (length 1 cm), inserted through the
biopsy channel of the endoscope. Of the patients, 14 (12 with stage III cancers,
and two with stage IV cancers) were treated by PDT alone, and 17 patients (15
with stage III cancers, and two with stage IV cancers) received PDT under HBO at
a level of 2 absolute atmospheric pressures (ATA). Transcutaneous PO2 levels of
500-750 mm Hg under HBO, compared with transcutaneous PO2 levels of 60-75 mm Hg
under normobaric conditions, were measured. RESULTS: Improvements regarding
dysphagia and stenosis diameter were obtained in both treatment arms with no
significant differences (P = 0.36 and 0.14, respectively). The tumor length also
decreased in both groups and showed a significant difference in favour of the
PDT/ HBO group (P = 0.002). Kaplan-Meier statistics showed median overall
survival for the PDT group and the PDT/HBO group as 7.0 and 12 months
respectively. The 12-month survival rate was 28.6% for the PDT group and 41.2%
for the PDT/HBO group. Logrank test showed a difference in survival in favor of
the PDT/HBO group (P = 0.059). No major treatment-related complication occurred,
and the 30-day mortality rate was 0%. CONCLUSIONS: Combined PDT/HBO represents a
new approach in the treatment of esophageal cancer which, in this pilot study,
appears to have enhanced the efficiency of PDT.
PMID- 10691272
TI - Thermoplastic stents: a new concept for endoluminal prosthesis.
AB - BACKGROUND AND STUDY AIMS: Intraluminal stenting of organs with stenoses or
fistulae in anatomically difficult locations (for instance cardia, pylorus, large
bowel), with a tendency to kinking or increased motility, still carries a high
risk of stent dislocation. In the search for a solution, we report on the use of
a new thermoplastic stent in animal experiments. MATERIAL AND METHODS: The new
stent consists of a plastic-coated wire mesh which can be heated electrically.
Once it is warmed up to 55 C, its size and shape can be changed. After being
expanded by a dilatation balloon across the stenosed area, the stent can be
fitted onto the inner organ surface. This guarantees a low dislocation risk and
high stability. In an animal experiment, stents were endoscopically placed in the
trachea and the surgically stenosed esophagus of two dogs. The animals were
observed for 3 months. RESULTS: The thermostents were implanted easily and
without complications. It was possible to mold the thermostent evenly onto the
intraluminal wall. No stent dislocation, bleeding or perforation was observed.
Upon histologic evaluation, granulation tissue was found to be growing through
the wire mesh of the stent. CONCLUSION: It was shown that the stent described
here can be implanted without major problems. The greater effort of the
implantation procedure, in comparison with self-expanding stents, is compensated
by the special mechanical characteristics of the stent. These characteristics may
permit implantation in anatomically difficult locations where up to now stenting
has been impossible or inadequate.
PMID- 10691273
TI - Sigmoid stiffener for decompression tube placement in colonic pseudo-obstruction.
AB - BACKGROUND AND STUDY AIMS: Decompression tube placement improves outcome in
colonic pseudo-obstruction (CP) which is refractory to conservative measures,
especially if the decompression tube is placed proximal to the hepatic flexure.
We evaluate the ability of a sigmoid stiffener to facilitate more proximal
colonoscopy and decompression tube placement. PATIENTS AND METHODS: A sigmoid
stiffener is used in the standard fashion during colonoscopic decompression for
pseudo-obstruction. After cecal wire placement, the colonoscope is withdrawn,
leaving the stiffener and wire in place. By passing through the stiffener, an
over-wire decompression tube can avoid sigmoid looping. We compared proximal
extent of colonoscopy, tube position, endoscopy time, and patient outcomes using
a sigmoid stiffener, with a control group of patients treated previously.
Patients with colonic ischemia were excluded. RESULTS: Using this technique, nine
consecutive colonoscopies and decompression tube placements reached the right
colon. Significantly, only three of seven control colonoscopies and two control
decompression tubes did so. However, improvements in procedural time and patient
outcome did not reach statistical significance. No complications occurred.
CONCLUSION: The use of a sigmoid stiffener during colonic decompression allows
more proximal colonoscopy and decompression tube placement, with possible
clinical benefit. We do not use this technique in the setting of left colon
ischemia.
PMID- 10691274
TI - Development of a speech-based dialogue system for report dictation and machine
control in the endoscopic laboratory.
AB - BACKGROUND AND STUDY AIMS: Reporting and machine control based on speech
technology can enhance work efficiency in the gastrointestinal endoscopy
laboratory. MATERIALS AND METHODS: The status and activation of endoscopy
laboratory equipment were described as a multivariate parameter and function
system. Speech recognition, text evaluation and action definition engines were
installed. Special programs were developed for the grammatical analysis of
command sentences, and a rule-based expert system for the definition of machine
answers. A speech backup engine provides feedback to the user. Techniques were
applied based on the "Hidden Markov" model of discrete word, user-independent
speech recognition and on phoneme-based speech synthesis. Speech samples were
collected from three male low-tone investigators. RESULTS: The dictation module
and machine control modules were incorporated in a personal computer (PC)
simulation program. Altogether 100 unidentified patient records were analyzed.
The sentences were grouped according to keywords, which indicate the main topics
of a gastrointestinal endoscopy report. They were: "endoscope", "esophagus",
"cardia", "fundus", "corpus", "antrum", "pylorus", "bulbus", and "postbulbar
section", in addition to the major pathological findings: "erosion",
"ulceration", and "malignancy". "Biopsy" and "diagnosis" were also included. We
implemented wireless speech communication control commands for equipment
including an endoscopy unit, video, monitor, printer, and PC. The recognition
rate was 95%. CONCLUSIONS: Speech technology may soon become an integrated part
of our daily routine in the endoscopy laboratory. A central speech and laboratory
computer could be the most efficient alternative to having separate speech
recognition units in all items of equipment.
PMID- 10691275
TI - Interventional endoscopic ultrasonography: state of the art at the new millenium.
PMID- 10691277
TI - Guidelines on cleaning and disinfection in GI endoscopy. Update 1999. The
European Society of Gastrointestinal Endoscopy.
PMID- 10691276
TI - A little girl with pancreatitis.
PMID- 10691278
TI - Protocol for reprocessing endoscopic accessories. European Society of
Gastrointestinal Endoscopy.
PMID- 10691279
TI - Simple hemostatic procedure for hemorrhagic duodenal ulcer: two cases of arterial
hemorrhage quickly controlled by balloon compression.
AB - We utilized balloon compression in two cases of arterial hemorrhage from duodenal
ulcers. The bleeding was quickly controlled in both cases. The advantages of this
technique are its simplicity and ease of performance, and the fact that it does
not require precise identification of the bleeding point in the duodenal bulb. No
serious complications, such as perforation or stenosis, are associated with this
technique. During the healing of the ulcer, balloon expansion may result in
decreased duodenal bulb deformity. The following points, however, should be
clarified in future studies: a) the stability of the duodenal bulb after longer
term balloon compression, and b) the optimum amount of cold water to be injected
into the balloon and the optimum compression time.
PMID- 10691280
TI - Gut perforation caused by biliary endoprosthesis.
AB - Two cases are reported of perforation of the gut caused by biliary
endoprosthesies in the three-year period 1993-1995. The first patient was an 81
year-old man who had perforation of the terminal ileum caused by a straight 10
French/7 cm stent which had been dislodged from the bile duct; he underwent
laparotomy but did not recover. The second patient was an 86-year-old man who had
perforation of the sigmoid colon caused by a straight 7 French/5 cm stent left in
the duodenum during a stent exchange procedure; he was successfully treated
laparoscopically. Two cases of gut perforation in a three-year period is a rather
high rate of this rare complication of placement of biliary endoprostheses.
PMID- 10691281
TI - Multiple pulmonary glue emboli following gastric variceal obliteration.
PMID- 10691282
TI - Laparoscopic repair of diaphragmatic iatrogenic hernia.
PMID- 10691283
TI - Surgical clips incorporated into a duodenal ulcer: a rare complication after
elective laparoscopic cholecystectomy.
PMID- 10691284
TI - Gastroileocutaneous fistula: an unusual complication of percutaneous endoscopic
gastrostomy.
PMID- 10691285
TI - Experience of laparoscopic cecoplication for mobile cecum.
PMID- 10691286
TI - Composite carcinoma-carcinoid tumor of the rectum treated by endoscopic removal.
PMID- 10691287
TI - Esophageal aspergillosis: an unusual endoscopic finding.
PMID- 10691289
TI - Par-4: an emerging pivotal player in neuronal apoptosis and neurodegenerative
disorders.
AB - Prostate apoptosis response-4 (Par-4) is a 38-kDa protein initially identified as
the product of a gene upregulated in prostate tumor cells undergoing apoptosis.
Par-4 contains both a death domain and a leucine zipper domain, and has been
shown to interact with several proteins known to modulate apoptosis, including
protein kinase Czeta, Bcl-2, and caspase-8. A rapid increase in Par-4 levels
occurs in neurons undergoing apoptosis in a variety of paradigms, including
trophic factor withdrawal, and exposure to oxidative and metabolic insults. Par
4, which can be induced at the translational level, acts at an early stage of the
apoptotic cascade prior to caspase activation and mitochondrial dysfunction. The
mechanism whereby Par-4 promotes apoptosis may involve inhibition of the
antiapoptotic transcription factor NF-kappaB and suppression of Bcl-2 expression
and/or function. Studies of postmortem tissues from patients and animal models of
neurodegenerative disorders, including Alzheimer's, Parkinson's, and Huntington's
diseases, amyotrophic lateral sclerosis (ALS), and HIV encephalitis, have
documented increased levels of Par-4 in vulnerable neurons. Manipulations that
block Par-4 expression or function prevent neuronal cell death in models of each
disorder, suggesting a critical role for Par-4 in the neurodegenerative process.
Interestingly, Par-4 levels rapidly increase in synaptic terminals following
various insults, and such local increases in Par-4 levels appear to play
important roles in synaptic dysfunction and degeneration. A better understanding
of the molecular and cellular biology of Par-4 will help clarify mechanisms of
neuronal apoptosis, and may lead to the development of novel preventative and
therapeutic strategies for neurodegenerative disorders.
PMID- 10691288
TI - Inherited and experimentally induced changes in gating kinetics of muscle
nicotinic acetylcholine receptor.
AB - Ligand-gated ion channels (LGIC) allow rapid responses in the nervous system. The
nicotonic acetylcholine receptor (AChR) has been the model for structure-function
relationship studies on this superfamily. The AChR undergoes the following
functional events: 1. Binding of the neurotransmitter. 2. Opening of the ion
channel. 3. Conduction of ions across the pore. 4. Desensitization. The
equilibrium among these processes can be perturbed by alteration in the primary
structure of the AChR or by the presence of pharmacological agents. Changes in
the primary sequence leading to modifications in gating kinetics may occur in
association with physiological or pathological processes. Such changes can also
be genetically engineered to gain insights into structure-function relationships.
PMID- 10691290
TI - The regulation of hippocampal nicotinic acetylcholine receptors (nAChRs) after a
protracted treatment with selective or nonselective nAChR agonists.
AB - In rats, 1 mg/kg twice daily for 10 d of nicotine, a nonselective agonist of
nicotinic acetylcholine receptors (nAChRs), fails to change alpha4 and beta2
nAChR subunit mRNA but significantly decreased alpha7 nAChR subunit mRNA and
protein expression, which is associated with a 35-40% decrease in the number of
125I-alpha-Bgtx binding sites in hippocampus. In addition, this schedule of
nicotine treatment produced a 40% increase in the number of high- (K(D) 1 nM),
but decreased by 25% the number of low-affinity (K(D) 30 nM) binding sites for 3H
epibatidine in hippocampus. In contrast, repeated treatment with lobeline (2.7
mg/kg twice daily for 10 d), which selectively binds to high-affinity binding
nAChRs, fails to change the expression of high- or low-affinity nAChRs. These
data suggest that a simultaneous upregulation of high-affinity nAChRs and
downregulation of low-affinity nAChRs is elicited by ligands that can bind to
both low- and high-affinity nAChRs, but not by selective agonists of high
affinity nAChRs. One might infer that in hippocampus, high- and low-affinity
nAChRs may be located in the same cells. When these two receptor types are
stimulated simultaneously by nonselective ligands for high- and low-affinity
nAChRs, they interact, bringing about an increase in binding site density of the
high-affinity nAChRs.
PMID- 10691291
TI - Expression of aspartoacylase activity in cultured rat macroglial cells is limited
to oligodendrocytes.
AB - N-acetyl-L-aspartate (NAA) is an important osmolyte in the vertebrate brain and
eye, and its cyclical metabolism is accomplished in two separate compartments. In
the brain, NAA is synthesized primarily in neurons, and after its regulated
release, NAA is hydrolyzed by aspartoacylase, which is present in a glial
associated compartment. However, the precise nature of this hydrolytic
compartment has remained obscure. It has been proposed that one role of
aspartoacylase in the central nervous system (CNS) is as part of a molecular
water pump (MWP) that uses the NAA intercompartmental cycle to remove nerve cell
metabolic water against a water gradient and that oligodendrocytes comprise the
second compartment in this metabolic sequence. The absence of aspartoacylase
activity in Canavan disease (CD), a rare early onset genetic spongiform
leukodystrophy, is associated with CNS edema, intramyelinic swelling and a
progressive loss of oligdendrocytes. In order to evaluate the MWP hypothesis and
its possible relationship to the etiology of CD further, both oligodendrocytes
and astrocytes obtained from neonatal rat brain were grown in culture and tested
for the presence of aspartoacylase activity. The results of this study show for
the first time that aspartoacylase activity is expressed only in
oligodendrocytes. The meaning of this observation in understanding the function
of the NAA metabolic cycle is discussed.
PMID- 10691292
TI - Anandamides inhibit binding to the muscarinic acetylcholine receptor.
AB - Loss of memory and cholinergic transmission are associated with both Alzheimer's
disease (AD) and marijuana use. The human brain muscarinic acetylcholine receptor
(mAChR), which is involved in memory function and is inhibited by arachidonic
acid, is also inhibited by anandamides. Two agonists of the cannabinoid receptor
derived from arachidonic acid, anandamide (AEA) and R-methanandamide, inhibit
ligand binding to the mAChR. Binding of the mAChR antagonist [3H]quinuclidinyl
benzilate ([3H]QNB) is inhibited up to 89% by AEA (half-maximal inhibition at 50
microM). Binding of the more polar antagonist [N-methyl-3H]scopolamine ([3H]NMS)
is inhibited by AEA up to 76% (half-maximal inhibition at 44 microM). R
methanandamide inhibits more than 90% of both [3H]QNB binding (I50 = 34 microM)
and [3H]NMS binding (I50 = 15 microM) to the mAChR. Both AEA and R-methanandamide
stimulate mAChR binding of the agonist [3H]oxotremorine-M at low concentrations
(25-75 microM), but significantly inhibit agonist binding at higher
concentrations (I50 = 150 microM). The cannabinoid antagonist SR141716A did not
alter AEA or R-methanandamide inhibition of [3H]NMS binding to the mAChR, even at
concentrations as high as 1 microM. Further, the cannabinoid agonist WIN 55212-2
does not alter antagonist binding to the mAChR. This demonstrates that mAChR
inhibition by the anandamides is not mediated by the cannabinoid receptor. Since
AEA and R-methanandamide are structurally similar to arachidonic acid, they may
interact with the mAChR in a similar manner to inhibit receptor function.
PMID- 10691293
TI - Reactive oxidant species in piriform cortex extracellular fluid during seizures
induced by systemic kainic acid in rats.
AB - Kainic acid (KA) administered systemically to rats produces seizures and brain
damage. We measured an increase in reactive oxidant species (ROS) during KA
induced seizures in the extracellular fluid (ECF) of the piriform cortex, a brain
region known to be subsequently damaged. Intracerebral microdialysis samples were
collected and assayed for isoluminol-dependent chemiluminescence before and after
injection of KA (16 mg/kg, i.p.). Hydrogen peroxide (H2O2) concentrations were
calculated from catalase-sensitive chemiluminescence, the difference between
total and catalase-resistant chemiluminescence. During generalized tonic-clonic
seizures, both total and catalase-resistant chemiluminescence increased
significantly in samples from brain ECF. Catalase-resistant chemiluminescence,
most likely produced by ascorbic acid, increased for a full hour during sustained
seizure activity. H2O2 concentrations showed a trend towards elevation during
seizures. Increased ROS suggest that oxidative stress occurs in brain ECF during
sustained seizure activity.
PMID- 10691294
TI - Region-specific changes in prodynorphin mRNA and ir-dynorphin A levels after
kindled seizures.
AB - The opioid peptide dynorphin is thought to be implicated in specific types of
seizures. In particular, complex partial seizures have been shown to cause
release of dynorphin, activation of prodynorphin gene expression, and new peptide
synthesis in the hippocampus. In this study, the kinetics of the seizure-induced
changes in prodynorphin mRNA and ir-dynorphin A levels in the hippocampus have
been compared with those induced in the temporal and frontal cortex, i.e., in
other regions involved in the pathophysiology of complex partial seizures.
Experiments have been run using kindling, one of the most valuable models of
partial epilepsy. In the hippocampus (1) prodynorphin mRNA levels transiently
increase (threefold) 1 h after kindled seizures, and return to baseline by 2 h,
and (2) dynorphin A levels are slightly decreased at 1 h, but increase (twofold)
at 2 h and return to baseline by 6 h. In the temporal and in the frontal cortex,
a late (beginning at 2 h) and prolonged (up to 24 h) decrease in both
prodynorphin mRNA and ir-dynorphin A levels have been observed. These data
suggest that differential changes in dynorphin metabolism occur in different
brain areas after seizures. The mechanisms and functional implications of this
observation remain to be investigated.
PMID- 10691295
TI - Increased vulnerability of neuronal cell lines to sodium nitroprusside-mediated
toxicity is caused by the decreased level of nitric oxide metabolites.
AB - Nitric oxide (NO) is an unstable radical produced during the oxidative
deamination catalyzed by NO synthase (NOS) that converts L-arginine to L
citrulline. NO is also generated nonenzymatically from a group of compounds,
called NO donors, such as sodium nitroprusside (SNP). NO directly or through its
metabolites has been implicated in several disorders, including Alzheimer's
disease (AD). Since NO is a highly labile unstable free gas, we measured the
stable end products, nitrite and nitrate (NOx). Here, we investigated the effect
of SNP-mediated NO release in different cell types and its effect on the beta
amyloid precursor protein (betaAPP). When different cell types were induced with
SNP, a significant level of NOx was detected in a time and dose-dependent manner
over the spontaneous release of NOx by SNP. The astrocytes, glial, and epithelial
cell lines released significantly higher level of NOx as compared to neuronal
cells following the exposure of SNP. The latter group of cells was more sensitive
to NO-mediated cytotoxicity, as demonstrated by the lactate dehydrogenase assay.
The SNP-mediated toxicity is known to be caused by the accumulation of cyanide
ions and we report that the ability of cells to protect against it depends on the
levels of nitric oxide metabolites. Cell lines, such as astrocytic and
epithelial, that produce more NOx are better protected against the SNP-induced
toxicity than the less NOx-protecting neuronal cell lines. The possibility of
differential susceptibility of neurons and astrocytes resulting from the
different content of reduced glutathione is also discussed. The release of NOx
was prevented by cotreatment with a NO scavenger and superoxide dismutase but not
by a NOS inhibitor. The activity of NOS was decreased when cytosolic extracts
were incubated with SNP. In the conditioned medium of SNP-induced cells, the
level of soluble betaAPP (sAPP) was decreased, and this decrease was more
apparent in neuronal than astrocytic cell lines. Taken together, these results
suggest that the SNP-derived NO release is independent of the NOS pathway, that
various cell types metabolize SNP differently, and that neuronal cell lines are
more vulnerable with SNP treatment with lowered sAPP secretion. Since the
neuronal cell lines lack a nitric-oxide-generated protective mechanism, we
speculate that these cells may be the first targets of neurodegeneration by
several toxic agents, including the cyanides and peroxynitrites.
PMID- 10691296
TI - Histamine release from mast cells of EAE rats by Gi protein-dependent and IgE
dependent pathways.
AB - We investigated both Gi protein-dependent and IgE-dependent pathways that control
release of histamine by PMCs derived from EAE or Complete Freund's Adjuvant (CFA)
immunized rats. The number and histamine content of MCs per rat were the same
between normal and EAE rats. Activation of Gi pathway by substance P (SP), DSA,
48/80, and mastoparan resulted in a dose-dependent increase in release of
histamine by PMCs in normal, EAE-, and CFA-immunized rats. In EAE and CFA rats,
however, the induction was decreased by 10-20% compared to normal rats. The
histamine release induced by MP was decreased at a concentration of 3 microM, but
not at 10 microM in severe active EAE rats. Activation of the IgE pathway by MAM
and concanavalin A (Con A) in the presence of phosphatidylserine led to dose
dependent histamine release in normal rats, and a 10-25% lower level of induction
was observed in EAE rats. In CFA rats, the induction of histamine release was
equivalent to normal rats. There was an increase in intracellular calcium stores
following activation of both pathways in normal rats, whereas depletion of
calcium stores by ryanodine reduced the level of induction by 48/80 and MP by 9
11% in normal rats. In EAE rats, 48/80, Con A, and MAM induced a smaller
increase, but SP and MP induced larger or similar increases in calcium stores
compared to normal rats. It was unlikely that the calcium stores of the PMCs from
EAE rats were depleted, because MP stimulated calcium movement subsequent to the
release of histamine. These results suggested that the Gi pathway may not be
correlated to clinical manifestation of EAE, but cold be involved in the
inflammatory process, and that the IgE pathway is better associated with clinical
symptoms of EAE and may be more directly related to disease outcome.
PMID- 10691297
TI - The growth-associated protein GAP-43 is increased in the hippocampus and in the
gyrus cinguli in schizophrenia.
AB - Schizophrenia is a common and severe psychiatric disorder of unknown etiology.
Numerous neuropathological studies have found subtle structural changes in limbic
structures, especially medial temporal lobe structures and the gyrus cinguli. To
test the hypothesis that synaptic disturbances are involved in the pathogenesis
of schizophrenia, we studied the growth-associated protein 43 (GAP-43), a protein
localized to presynaptic terminals, suggested to be involved in establishment and
remodeling of synaptic connections, in postmortem brain tissue, using
quantitative Western blotting immunohistochemistry. The material consisted of
brain tissue from 17 schizophrenics (80 +/- 11 yr), diagnosed according to the
DSM-III-R criteria, and 20 age-matched controls (75 +/- 13 yr). Quantitative
analyses showed increased GAP-43 protein levels in schizophrenic compared to
control brains, both in the hippocampus (2.43 +/- 0.78 vs 1.00 +/- 0.29; p <
0.0001) and in the gyrus cinguli (1.52 +/- 0.21 vs 1.00 +/- 0.35; p < 0.0001).
Also by immunohistochemistry, increased GAP-43 staining was found in
schizophrenic compared with control brains, throughout all layers of the gyrus
cinguli and the hippocampus. Anomalous synaptic sprouting and reorganization,
with resultant "miswiring," as well as a defect in synaptic pruning have been
hypothesized to be pathogenetic factors in schizophrenia. We suggest that a
decreased synaptic density, whether caused by disturbed development or
damage/degeneration, may elicit a reactive synaptogenesis (reflected by an
increase in GAP-43), which may be functional or anomalous. Synaptic pathology in
the limbic system may be of importance in the development of psychotic symptoms
in schizophrenia.
PMID- 10691299
TI - Increased expression of prion protein is associated with changes in dopamine
metabolism and MAO activity in PC12 cells.
AB - Prion diseases of humans and animals occur following infection with infectious
agents containing PrP(Sc) or in situations in which there is a mutation of the
prion protein (PrP) gene. The cellular prion protein (PrP(C)) is a
sialoglycoprotein that is expressed predominantly in neurons. PrP(C) is converted
into a pathogenic form of PrP (PrP(Sc)), which is distinguishable from PrP(C) by
its relative resistance to protease digestion. A number of postulates have been
advanced for the function of normal PrP (PrP(C)), but this issue has not been
resolved. To investigate the function(s) of PrP(C), we established clonal PC12
cell lines, which have elevated PrP(C) expression. The results show that there
were alterations in dopamine metabolism and in monoamine oxidase (MAO) activity
in transfected PC12 cells that overexpress PrP(C). There was an increase in
concentration of DOPAC, a metabolite of dopamine, and in MAO activity in cells
overexpressing PrP(C). MAO is involved in oxidative degradation of dopamine (DA).
Our data suggest that PrP(C) plays a role in DA metabolism by regulating MAO
activity.
PMID- 10691298
TI - Mice transgenic for a human amyloid precursor protein promoter-lacZ reporter
construct.
AB - Transgenic mouse lines were generated that expressed a 2-kb amyloid precursor
protein (APP) promoter/beta-galactosidase reporter gene construction. In brain,
hippocampal pyramidal neurons, neurons in the deeper layers of cerebral cortex,
and neurons in several thalamic nuclei were heavily labeled by beta-galactosidase
histochemistry. In general, molecular layers and white matter regions did not
express the reporter gene. When compared with in situ hybridization for
endogenous murine APP RNA, the striatum and outer layers of cerebral cortex had
little reporter expression. Thus, the match between reporter expression and
endogenous APP expression in brain was not perfect. A similar mismatch between
the relative expression of the reporter gene and endogenous APP RNA distribution
was found in homogenates from several organs. Although prior work in transgenic
mice found similar mismatches in reporter gene distribution, none had tested the
APP promoter construct in response to neuronal injury. Kainic acid injections
successfully increased murine APP expression in the transgenic mice, but had no
effect on the reporter gene expression. Based on these data and those collected
by others, we conclude that the 2-kb region upstream of the APP transcription
initiation site contains some elements responsible for the tissue-specific
expression of this gene, but does not contain all the cis-acting elements
sufficient for either the differential tissue distribution of this gene or the
regulation of this gene subsequent to neural damage.
PMID- 10691300
TI - Chronic lead intoxication affects the myelin membrane status in the central
nervous system of adult rats.
AB - The aim of the experiments presented here was to discern whether prolonged
consumption of leaden water, which imitates an environmental exposure, affects
the structure of myelin in the central nervous system of adult rats and whether
the observed morphological destruction is reflected in biophysical and/or
biochemical changes. The results indicated that during chronic lead (Pb)
intoxication, the Pb level of the myelin fraction increases significantly.
Electron microscopy studies show that myelin in control experiments is built up
of ordered layers, whereas in a Pb-intoxicated sample, this order is destroyed in
large areas of all preparations. Morphological disturbances in Pb-intoxicated in
vivo myelin were reflected by changes in myelin membrane fluidity measured by
spectrofluorometry and electron paramagnetic resonance (EPR). Prolonged Pb
toxicity also caused significant changes in the morphological structure of
oligodendrocytes, an increase of phosphatidylethanolamine, and decrease of
protein SH group levels. Simultaneously, we found that the protein and total
phospholipid content and levels of phosphatidylinositol, sphingomyelin,
phosphatidyloserine, cholesterol, and the pattern of total myelin protein
obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)
in Pb-intoxicated myelin did not change compared to control values. Also, Pb
intoxication did not induce peroxidation by itself and did not accelerate
peroxidation produced by iron (Fe) in brain myelin.
PMID- 10691301
TI - Activity-dependent interaction of the intracellular domain of rat trkA with
intermediate filament proteins, the beta-6 proteasomal subunit, Ras-GRF1, and the
p162 subunit of eIF3.
AB - Many responses to nerve growth factor (NGF) are regulated through the receptor
tyrosine kinase trkA. To understand more fully the functions of trkA in NGF
responsive cells, we have expressed the intracellular domain of rat trkA as a
fusion protein with the yeast gal4 transcription factor, and used the fusion
protein to probe rat and mouse cDNA libraries by the yeast two-hybrid system. We
have identified a direct interaction between the intracellular domain of trkA and
two members of the intermediate filament (IF) family of proteins, the guanine
nucleotide exchange protein Ras-GRF1, the p162 subunit of eIF3, and the beta-6
proteasome subunit. The interactions are dependent on an active trkA kinase, and
RasGRF1, the beta-6 proteasomal subunit, and peripherin are directly
phosphorylated by trkA. The interaction with trkA is not affected by mutations at
either Tyr499 or Tyr794, the two major phosphotyrosine residues essential to the
activation and receptor binding of Shc, FRS-2/SNT, and phospholipase Cgamma-1,
and it is highly specific in vitro for trkA, with little or no binding observed
with trkB and/or trkC. The results show that trkA may play a regulatory role in a
variety of cellular functions in addition to neuritogenesis, including regulated
protein degradation and transcriptional activation.
PMID- 10691302
TI - Aberrant stress response associated with severe hypoglycemia in a transgenic
mouse model of Alzheimer's disease.
AB - Patients with Alzheimer's disease (AD) exhibit alterations in glucose metabolism
and dysregulation of the stress-responsive hypothalamic-pituitary-adrenal (HPA)
neuroendocrine system. The mechanisms responsible for these alterations and their
possible contributions to the neurodegenerative process in AD are unknown. We now
report that transgenic mice expressing a mutant form of human amyloid precursor
protein (APP) that causes inherited early-onset AD exhibit increased sensitivity
to physiological stressors, which is associated with aberrancies in HPA function
and regulation of blood glucose levels. Specifically, APP mutant mice exhibit
severe hypoglycemia and death following food restriction, and sustained
elevations of plasma glucocorticoid levels and hypoglycemia following restraint
stress. The alterations in HPA function and glucose regulation were evident in
relatively young mice prior to overt deposition of amyloid beta-peptide (A beta).
However, diffuse accumulations of A beta were present in the hypothalamus of
older mice, suggesting a role for soluble forms of A beta in dysregulation of HPA
function. Our data demonstrate disturbances in neuroendocrine function in APP
mutant mice similar to those seen in AD patients. These impairments in stress
response, glucocorticoid signaling, and regulation of blood glucose should be
considered in interpretations of data from past and future studies of APP mutant
mice.
PMID- 10691303
TI - Immunolocalization of tenascin-C in human type II fiber atrophy.
AB - Tenascin-C is a multifunctional extracellular matrix glycoprotein with
stimulatory and anti-adhesive or inhibitory properties for axon growth. Its
location and discontinuous expression are restricted in innervated muscle
tissues. Tenascin-C accumulated interstitially among human denervated muscle
fibers and close to normal-sized fibers. To expand our knowledge of the
expression of tenascin-C in human neuromuscular disorders, we investigated
immunohistologically 20 human muscle specimens with type II myofiber atrophy of
children and adults. Tenascin-C immunoreactivity in adult type II atrophy was
frequent, and accumulation in children was sparse and weak. In both groups,
tenascin-C immunoreactivity was found: 1. Interstitially around normal-sized type
II muscle fibers. 2. Around atrophic type II muscle fibers. 3. Around small
caliber myofibers with centrally located nuclei. These results indicate that
tenascin-C immunoreactivity: (1) is detectable around early denervated and
reinnervated muscle fibers and, therefore, (2) may reflect in part the
molecularly ongoing process of denervation and reinnervation in human type II
fiber atrophy.
PMID- 10691304
TI - Expression of vascular endothelial growth factor (VEGF) and platelet-derived
growth factor receptor-beta (PDGFR-beta) in human gliomas.
AB - The growth of solid tumors is highly dependent on vascular proliferation.
Vascular endothelial growth factor (VEGF), the main mediator of angiogenesis, and
platelet-derived growth factor receptor-beta (PDGFR-beta), receptor for the
potent mitogen PDGF, are two indicators of the angiogenic potential of human
gliomas. We studied a series of 57 surgical biopsies of astrocytic neoplasms by
immunohistochemistry to elucidate the relationship between tumor proliferation,
quantified as Ki67-LI, and the expression of these two proteins. Ki67-LI
increases throughout histological malignancy, although staining in endothelial
cells has rarely been recorded. Elevated amounts of VEGF-positive tumor cells
(VEGF-LI) were found in anaplastic astrocytomas and glioblastomas, mainly around
areas of necrosis, cysts, or edema. Endothelium of blood vessels was consistently
stained. PDGFR-beta positivity was found in glomeruloid formations and in tumor
cells, excluding pilocytic astrocytomas. Multinucleated giant cells and
perivascular tumor cells were positive in glioblastomas. In addition, peritumoral
microglia-like cells were also stained in some cases. Statistical correlation was
only found between PDGFR-beta and Ki67 LIs. In conclusion, VEGF as permeability
factor is involved in the development of secondary neoplastic changes, whereas
PDGFR-beta is directly correlated to proliferation indexes. Strong expression of
VEGF and PDGFR-beta found in endothelium and tumor cells would seem to support a
combined role in tumoral neoangiogenesis.
PMID- 10691305
TI - Fibroblast growth factor receptor 4 (FGFR4) is expressed in adult rat and human
retinal photoreceptors and neurons.
AB - The fibroblast growth factor (FGF) family, with its prototype members acidic FGF
(FGF-1) and basic FGF (FGF-2), binds to four related receptor tyrosine kinases,
termed FGFR1, R2, R3, and R4, expressed on most types of cells in tissue culture.
In many respects, the FGFR appear similar to other growth factor receptors; thus,
dimerization of receptor monomers on ligand binding is likely to be a requisite
for activation of the kinase domains, leading to receptor trans-phosphorylation.
Within the central nervous system (CNS), including retina, FGFR1 and R2 have been
widely described as the predominant forms. FGFR4 is reported to be strongly
expressed only during early stages of development, and apart from one small
region (the lateral habenular nucleus) is not detectable in adult CNS. Screening
of different neural and nonneural tissues by reverse transcriptase-polymerase
chain reaction (RT-PCR) revealed that whereas FGFR1 and R2 were strongly
expressed in adult cortex, cerebellum, retina, and kidney, robust FGFR4
expression was only seen in retina and kidney. FGFR4 mRNA was present within
fractions of the outer and inner nuclear layers isolated from adult rat retinas,
and could also be detected in pure photoreceptor cultures prepared from young rat
retinas. On the contrary, FGFR4 mRNA could not be detected in primary cultures of
retinal Muller glia or pigment epithelium, indicating specific enrichment in
retinal neurons. In situ hybridization studies of adult rat retina showed FGFR4
expression in all retinal cellular layers, especially prominent in the outer
nuclear layer. FGFR4 protein was detected by immunoblotting of homogenates of rat
retina, with specific antibody binding to bands at 115, 47, and 30 kDa. FGFR4
mRNA and protein were also reliably detected in postmortem adult human retina.
The potential roles of these signal transduction molecules in FGF-induced
biological responses in the retina are discussed.
PMID- 10691307
TI - Substitutions of tyrosine 601 in the human thyrotropin receptor result in
increase or loss of basal activation of the cyclic adenosine monophosphate
pathway and disrupt coupling to Gq/11.
AB - Constitutively activating mutations of the thyrotropin (TSH) receptor have been
identified as a molecular cause of toxic adenomas, nonautoimmune familial
hyperthyroidism, and sporadic congenital hyperthyroidism. By analyzing genomic
DNA from a toxic adenoma, we detected a novel somatic mutation in codon 601,
tyrosine to asparagine (Y601N), a residue located in the carboxyterminal part of
the fifth transmembrane helix. This codon is also notable for the presence of a
polymorphic variant, Y601H. These two naturally occurring substitutions (Y601N
and Y601H) were analyzed together with an artificial mutation, Y601F, to study
the role of this residue for receptor function further. Transient transfection
assays revealed that the Y601N mutation results in constitutive activation of the
cyclic adenosine monophosphate (cAMP) pathway, but that it is unable to couple to
Gq/11. Y601H and Y601F do not display basal activity while retaining
responsiveness to TSH, but also lose the ability to induce inositol phosphate
accumulation in response to TSH. These studies define Y601N as a mutation that
selectively activates the cAMP pathway, and they confirm that Y601H is not a
silent polymorphism. In conclusion, residue Y601 has an important role for the
characteristic constitutive basal activity of the TSH receptor and coupling to
Gq/11.
PMID- 10691306
TI - Activity-dependent neurotrophic factor-14 requires protein kinase C and mitogen
associated protein kinase kinase activation to protect the developing mouse brain
against excitotoxicity.
AB - Activity-dependent neurotrophic factor (ADNF) is a newly identified compound that
prevents in vitro neuronal death when present in fentomolar concentrations. ADNF
14, a 14 amino acid peptide derived from ADNF, has the same effects on growth as
the parent molecule. However, the transduction pathways and target cells for
these highly potent trophic factors are still unknown. We previously described a
mouse model of excitotoxic lesions of the developing neocortex mimicking several
hypoxic or hypoxic-like brain lesions observed in human fetuses and neonates. In
this model, cotreatment with the excitotoxin ibotenate and ADNF-14 prevented both
neuronal death in pups injected on the day of birth and white matter cystic
lesions in pups treated 5 d after birth. In the present study, coadministration
of ibotenate, ADNF-14, and selective transduction pathway inhibitors showed that
activation of protein kinase C (PKC) and mitogen-associated protein kinase kinase
was critical for neuroprotection. Immunocytochemistry revealed that ADNF-14
activated PKC and mitogen-associated protein kinase in cortical neurons on the
day of birth and in white matter astrocytes on the fifth postnatal day. Taken in
concert, these data identify PKC and mitogen-associated protein kinase pathways
as critical to ADNF-14-induced neuroprotection of the developing brain against
excitotoxic damage.
PMID- 10691308
TI - Quantitative analysis of DNA binding affinity and dimerization properties of wild
type and mutant thyroid hormone receptor beta1.
AB - Thyroid hormone (triiodothyronine [T3]) actions are mediated through binding of
thyroid hormone receptors (TRs) to specific DNA sequences (thyroid hormone
response elements [TREs]) as monomers, homodimers, and heterodimers with thyroid
hormone receptor auxiliary proteins (TRAPs). We quantitatively characterized
dimerization of wild-type (WT) and mutant TRbetas by coimmunoprecipitation, and
binding to DNA by electrophoretic gel mobility shift assays (EMSA). Binding
affinities of TR retinoid X receptor-alpha (RXRalpha) heterodimers to DNA were
determined by competing with excess nonradiolabeled TREs in EMSA. TRs in vitro
synthesized in reticulocyte lysates (RL), and human RXRalpha expressed in a Sf9
cell-baculovirus system (BAC), were coincubated with 32P-labeled rat malic enzyme
(ME), palindromic (PAL), or chicken lysozyme F2 (F2) TREs. The mutant TRbetas
tested were R316H and G345R, which have nondetectable T3 binding and have
previously been reported to show weak and potent dominant negative effect,
respectively. Scatchard analysis showed no significant differences in Kas between
WT and mutant TR-RXRalpha heterodimers binding to DNA. We measured affinity of
heterodimerization between TRs and RXRalpha in solution in the absence of DNA,
and by coimmunoprecipitation using anti-TRbeta1WT specific antibodies. 35S
labeled RL-RXRalpha was incubated with BAC-WT or TRbeta or R316H in the absence
or presence of increasing amounts of nonlabeled BAC-RXRalpha. Displacement curves
were obtained by counting radioactivity of precipitated 35S-RXRalpha, that was
analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)
and autoradiography. Kds of WT and TRbeta R316H heterodimerizing with RXRalpha
were approximately the same. Binding affinity of TR homodimers for F2-TRE was
studied because this TRE binds homodimers strongly. Scatchard analysis clearly
showed that DNA binding affinity of BAC-WT homodimers did not differ with or
without 100 nM T3, but maximal binding capacity (MBC) was reduced three-fold to
fourfold in the presence of 100 nM T3. In contrast, BACTRbeta-R316H homodimers
showed a fivefold reduction in DNA binding affinity for F2, both in the presence
and absence of T3, and approximately the same MBC as WT in the absence of T3.
Mutant RL-G345R homodimers showed approximately the same Ka as RL-WT homodimers
for binding to F2 and the same MBC in the presence and absence of T3. These
results indicate that (1) T3 reduced TRbeta homodimerization in solution but does
not effect DNA binding of formed homodimers; (2) T3 does not influence DNA
binding affinity of TR/RxR heterodimers; and (3) TRbeta mutant R316H homodimers
have reduced DNA binding affinity but homodimerization and heterodimerization in
solution does not differ from WT TRbeta.
PMID- 10691309
TI - N-ras mutation in poorly differentiated thyroid carcinomas: correlation with bone
metastases and inverse correlation to thyroglobulin expression.
AB - Codon 61 of the N-ras oncogene was screened for mutations in 99 surgically
resected thyroid carcinomas by a polymerase chain resection (PCR)-based method
(PCR-primer introduced restriction with enrichment of mutant alleles [PCR
PIREMA]). A point mutation of the N-ras oncogene at the codon 61 was detected in
16 of 99 (16.2%) thyroid carcinomas examined by this method. No RAS alteration
was detected in the group of 11 medullary thyroid carcinomas, while 3 of 31
(10.0%) papillary carcinomas, 2 of 5 (40%) follicular carcinomas, 8 of 44 (18.2%)
poorly differentiated carcinomas, and 3 of 5 (60%) undifferentiated carcinomas
showed an activation of N-RAS proto-oncogene. Interestingly, two primary
follicular tumors and their corresponding bone metastases, showed N-ras
mutations. In the same cases we evaluated the expression of thyroglobulin by
immunohistochemical analysis. Although the majority of well-differentiated
carcinomas expressed a high level of thyroglobulin, the expression of the same
antigen was absent or only occasional weakly positive in 33 of 44 poorly
differentiated carcinomas. Interestingly, N-ras mutation was restricted to the
group of tumours with low or absent thyroglobulin expression, suggesting that
this genetic change is prevalent in less differentiated tumors.
PMID- 10691310
TI - Molecular alterations involving p53 codons 167 and 183 in papillary thyroid
carcinomas from chernobyl-contaminated regions of belarus.
AB - After the Chernobyl accident in 1986, there was a significant increase in the
incidence of papillary thyroid carcinoma in fallout-exposed children from
Belarus. We studied the p53 gene from 24 papillary thyroid carcinoma cases
presenting in 1996. All subjects lived in contaminated regions of Belarus at the
time of the accident and were under age 20 when exposed to fallout. Exons 5
through 9 of p53 were amplified from genomic tumor DNA using the polymerase chain
reaction (PCR). The PCR products were analyzed by direct DNA sequencing using an
automated sequencer. Five cases each exhibited two molecular alterations within
exon 5. Alterations were confirmed by sequencing in both directions. One
alteration, involving codon 167 (CAG-->CAT) in all five cases, resulted in the
substitution of HIS for GLN. The second alteration, involving codon 183 (TCA-
>TGA) in all five cases, resulted in a premature termination codon. Leukocyte DNA
from each of the positive cases was analyzed and found to contain only wild-type
p53 sequence. These results suggest that mutations involving codons 167 and 183
in the p53 locus are important in the pathogenesis of a subset (21%) of radiation
induced papillary thyroid carcinomas from Belarus.
PMID- 10691311
TI - Accuracy of free thyroxine measurements across natural ranges of thyroxine
binding to serum proteins.
AB - Systemic inaccuracies, proportional to the concentrations of serum proteins and
the thyroxine (T4) they carry, have been reported in direct free T4 immunoassays.
However, analytical recoveries of free T4 have not been carefully examined in
most current methods, and they have not previously been examined across the
pathophysiological range of serum T4 binding. In the present study we
investigated ranges of serum T4 binding using free and total T4 measurements from
1359 individuals. Carefully characterized, gravimetrically calibrated, serum
based free T4 test solutions were then prepared with a constant normal free T4
concentration (12 ng/L) and varied serum T4 binding (approximately 300:1 to
24,000:1, ng protein bound T4: ng free T4). These standardized test solutions
were analyzed using five T4 analog based free T4 methods. Analytical recoveries
were calculated as ratios of actual free T4 measurements to the target value, and
expressed as a percent of the target. Analytical recoveries were directly
proportional to the extent of serum T4 binding and ranged 2% to 155%, 25% to
131%, 53% to 106%, 37% to 93%, and 37% to 73%, lowest to highest, in different
methods. These systemic inaccuracies will confound interpretations of free T4
test results in clinical conditions with altered T4 binding. Future
investigations into free T4 status must examine the analytical recovery of the
free T4 method(s) used, as they relate to the extent of serum T4 binding in the
clinical condition(s) studied.
PMID- 10691312
TI - Functions of thyroid hormone receptors in mice.
AB - Thyroid hormone receptors (TRs) play a central role in mediating the actions of
thyroid hormone in development and homeostasis in vertebrate species. The TRs are
nuclear receptors that act as ligand-regulated transcription factors. There are
two TR genes (TRalpha and TRbeta), each capable of generating different variant
products, suggesting a potentially complex array of TR pathways. Targeted
mutagenesis in the mouse has indicated that there are specific individual
functions for the TR genes in vivo. The deletion of combinations of TRalpha and
TRbeta variants has revealed that additional functions are convergently regulated
by both TR genes and indicates that control of an extended range of functions is
facilitated by a network of specific and common TR pathways. The TR-deficient
mouse models have allowed investigation of the TR pathways underlying many
functions of thyroid hormone and provide a unique perspective on receptor
mediated mechanisms of biological control.
PMID- 10691313
TI - Preparation and culture of a serum-free human thyroid follicle system and its
application for measuring thyroid hormone secretion, iodide uptake and
organification, cyclic adenosine monophosphate formation, gene expression, and
cell growth.
AB - We describe a system of human thyroid follicles cultured in collagen suspended in
serum-free medium. The method allows measurement of thyroid hormone secretion,
iodide uptake and organification, cyclic adenosine monophosphate (cAMP)
formation, gene expression, as well as cell growth. The system is superior to
follicles freely suspended in cultured medium and also, as demonstrated by
parallel experiments, to monolayer culture systems. A detailed description of the
optimal conditions of the method is provided that, over a period of 8 years, has
proven to be a powerful tool for measuring thyroid cell function, gene expression
and cell proliferation.
PMID- 10691314
TI - Potential repercussions for the progeny of maternal hypothyroxinemia during
pregnancy.
PMID- 10691315
TI - Fine-needle aspiration of thyroid nodules in radiation-exposed patients.
AB - External radiation used to treat benign conditions in the head and neck area
results in an increased risk of thyroid cancer in exposed individuals. Fine
needle aspiration (FNA) biopsy is the standard procedure used to evaluate
suspicious thyroid nodules. Its accuracy has been extensively studied, but little
is known about FNA in irradiated patients. We analyzed the FNA experience of 136
irradiated subjects. Fifty-two had surgery enabling a comparison of the
histologic diagnosis with the FNA results. In these 52 patients with a total of
53 FNAs, 20 were reported as benign, 14 as follicular neoplasms, 6 as papillary
cancer, and 13 as inadequate samples. Seven malignant nodules were aspirated; 4
were reported as papillary cancer, 1 was reported as benign and 2 had inadequate
specimens. An additional 11 patients had thyroid cancer in foci that were not
subjected to FNA. For the nodules that were aspirated, and considering an FNA
report of follicular neoplasm as a false-positive when a follicular adenoma or a
colloid nodule was found at surgery, the calculated sensitivity was 80%,
specificity 54%, positive predictive value 20%, and negative predictive value
95%. Of the 14 follicular neoplasm FNA diagnoses, 10 were colloid nodules (71%),
and 4 only were follicular adenomas. We conclude that the sensitivity of FNA in
irradiated patients is similar to what is reported for the general population.
However, smaller malignant nodules are common and are not diagnosed by the FNA.
Also, the FNA diagnosis of follicular neoplasm is often inaccurate and inadequate
aspirations are frequent in this patient group.
PMID- 10691316
TI - Postpartum thyroiditis: epidemiology and clinical evolution in a nonselected
population.
AB - Postpartum thyroiditis (PPT) presents in approximately 5% of women. Its
incidence, clinical characteristics, and evolution were studied in a nonselected
population of Mediterranean women. Six hundred five healthy women, recruited
between the 36th week of pregnancy and the 4th postpartum day, underwent initial
clinical and biological evaluation and postpartum at 1 (n = 605), 3 (n = 552), 6
(n = 574), 9 (n = 431), and 12 (n = 444) months. PPT was diagnosed in women with
transient hyperthyroidism between 1 and 3 months postpartum and/or hypothyroidism
between 3 and 6 months postpartum. Permanent hypothyroidism was considered if it
was overt and persisted one year after diagnosis. The incidence rate of PPT was
7.8%. Eighty-two percent of PPT patients had hormone abnormalities at the 6th
month postpartum, 8.8% showed depression and 51% goiter. PPT was manifest as
hyperthyroidism plus hypothyroidism in 35.5% of patients, because only transient
hyperthyroidism in 22.2% and as hypothyroidism alone in 42.3%. Five patients with
hypothyroidism during PPT (0.82% of the initial population, 11.1% of PPT
patients, and 15.6% of hypothyroidism PPT patients) presented permanent
hypothyroidism after a follow-up of 39.8 (4.2) months. PPT was found in 7.8% of
general Mediterranean population. We recommend evaluation at the 6th postpartum
month to diagnose the majority of PPT women and indefinite follow-up of
hypothyroid PPT patients to detect permanent hypothyroidism.
PMID- 10691317
TI - The blood spot thyrotropin method is not adequate to screen for hypothyroidism in
the elderly living in abundant-iodine intake areas: comparison to sensitive
thyrotropin measurements.
AB - We investigated whether the blood spot thyrotropin (TSH) method was adequate for
screening elderly subjects with abundant iodine intake (median excretion 330
microg/g creatinine) for hypothyroidism. In 97 healthy adults (group A), 210
nursing home residents (group B) and 265 elderly subjects living at home (group
C) serum (sensitivity < 0.02 mU/L, cost 1.2 U.S. dollars [USD]) and blood spot
TSH (sensitivity < 1.0 mU/L, cost 0.4 USD) were measured, and the sensitivity and
specificity of different blood spot TSH cutoff points to detect cases with
elevated serum TSH were calculated. Elevated (> 3.5 mU/L) serum TSH levels (group
A, 6.2%; group B, 16.2%; group C, 22.3%; B > A, p = 0.025; C > A, p < 0.001) were
detected with the required sensitivity of greater than 0.9 only if the cutoff
point of the blood spot TSH was set as low as 2.5 mU/L, but this led to a
considerable loss of specificity. At cutoff point 2.5 mU/L, the rate of
positivity was 39.3% and the cost of blood spot screening/person increased to
0.88 USD, considering that positive cases have to be rechecked by serum TSH to
exclude false positivity. Cases with significantly elevated (> 10.0 mU/L) serum
TSH (group A, 1.03%; group B, 2.85%; group C, 2.20%) were detected at blood spot
cutoff points 10.0-4.0 mU/L with a sensitivity of 1.0 and without considerable
loss of specificity. We conclude that while screening for hypothyroidism in the
elderly population with abundant iodine intake is justified by the high
prevalence of elevated ultrasensitive serum TSH values, the sensitivity of the
blood spot method is insufficient to detect the subclinical hypothyroidism
accurately and would, therefore, fail to detect most affected subjects.
PMID- 10691318
TI - Administration of interferon-gamma in healthy subjects does not modulate thyroid
hormone metabolism.
AB - Cytokines, such as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL-2),
IL-6, and interferon-alpha (IFN-alpha), alter human thyroid hormone metabolism
and may be involved in the pathogenesis the euthyroid sick syndrome. Experimental
data suggest that interferon-gamma (IFN-gamma) could be another cytokine that
might influence thyroid hormone metabolism. To evaluate whether IFN-gamma can be
involved in the pathogenesis of the alterations in thyroid hormone metabolism in
humans with nonendocrine illness, we measured thyroid hormone concentrations in
six healthy volunteers during 24 hours in a placebo controlled trial: once after
subcutaneous administration of IFN-gamma (Immukine, [Boehringer Ingelheim GmbH,
Ingelheim/Rheim, Germany] 100 microg/m2 subcutaneous) and once after the
administration of saline (control). In addition, we measured cytokine
concentrations in plasma (TNF-alpha and IL-6). IFN-gamma did not induce effects
on any of the measured thyroid hormone and thyroid-stimulating hormone (TSH)
plasma concentrations. Moreover, IFN-gamma did not affect TNF-alpha plasma
levels. Only a modest but significant elevation of plasma IL-6 levels was
detected after administration of IFN-gamma (p < 0.05 vs. control). It is
concluded that IFN-gamma administration to healthy humans does not result in
short term alterations of thyroid hormone metabolism. These data do therefore not
support a role of IFN-gamma in the pathogenesis of the euthyroid sick syndrome in
humans as might be deduced from in vitro and in vivo animal studies.
PMID- 10691319
TI - Unusual malabsorption of levothyroxine.
AB - We report a 50-year-old woman, with overt hypothyroidism undergoing thyrotropin
(TSH)-stimulating hormone suppressive levothyroxine (LT4) treatment after
subtotal thyroidectomy. At her first visit to our department, the laboratory
results revealed a borderline low free thyroxine (FT4) level accompanied by a
clearly elevated TSH level. Both parameters did not significantly change during
therapy with an oral dose of 500 microg of LT4. Investigations revealed
malabsorption of oral administrated LT4. Thyroid serum hormone levels only became
normal during parenteral therapy with LT4.
PMID- 10691320
TI - Managed care and the practicing thyroidologist: an overview.
PMID- 10691321
TI - Unilateral ophthalmopathy in a patient with Hashimoto's thyroiditis.
PMID- 10691322
TI - Thyrotoxicosis after interferon-alpha therapy.
PMID- 10691323
TI - Use of colony-stimulating factors for the treatment of antithyroid drug-induced
agranulocytosis: a retrospective study in twelve patients.
PMID- 10691324
TI - Bucharioside and buchariol from Salvia bucharica.
AB - A new monoterpene-glycoside (2-exo-beta-D-glucopyranosyl-1,8-cineol) named
bucharioside from the methanol-soluble part and a new sesquiterpenoid (4,10-epoxy
6alpha-hydroxyguaiane) named buchariol from the hexane-soluble part of Salvia
bucharica were obtained. Their structures were elucidated with the help of NMR
spectroscopy including 1D and 2D experiments.
PMID- 10691325
TI - [Treatment of gastric phytobezoars with cellulase].
PMID- 10691326
TI - Metabolic interactions between mibefradil and HMG-CoA reductase inhibitors:
linking in vitro with in vivo information.
PMID- 10691327
TI - Oochroconis gallopava endophthalmitis in fludarabine treated chronic lymphocytic
leukaemia.
PMID- 10691328
TI - Vancomycin and ceftazidime incompatibility upon intravitreal injection.
PMID- 10691329
TI - Acute zonal occult outer retinopathy.
PMID- 10691330
TI - Linear naevus sebaceous syndrome, optic disc staphyloma, and non-rhegmatogenous
retinal detachment.
PMID- 10691331
TI - Can leucocoria be the first manifestation of protrin C deficiency?
PMID- 10691332
TI - Proceedings of the Sheffield Meeting of the Society for Research into
Hydrocephalus and Spina Bifida. 1999.
PMID- 10691333
TI - Photo quiz. Infection due to Exophiala jeanselmei.
PMID- 10691334
TI - Role of muscle-derived cells in hematopoietic reconstitution of irradiated mice.
PMID- 10691335
TI - Inheritance of chromosomally integrated viral DNA?
PMID- 10691336
TI - Detection of vascular endothelial growth factor in AIDS-related primary effusion
lymphomas.
PMID- 10691337
TI - X-linked thrombocytopenia identified by flow cytometric demonstration of
defective Wiskott-Aldrich syndrome protein in lymphocytes.
PMID- 10691338
TI - Proceedings of the 5th International Potsdam Symposium on Tick-borne Diseases:
Tick-borne Encephalitis and Lyme Borreliosis. Berlin, Germany, February 26-27,
1999.
PMID- 10691339
TI - Commentary on Garety and Freeman II: 'Cognitive approaches to delusions--A
critical review of theories and evidence'.
PMID- 10691341
TI - Leishmania braziliensis promastigotes and amastigotes interact differently with
host macrophages.
AB - In vitro and in vivo ultrastructral studies reveal that the parasite entrance
into the macrophage occurs by phagocytosis. The early stage of phagocytosis
exhibited different ultrastructural characteristics in both forms of the
parasite. Long and prominent projections from peritoneal exudate macrophages made
focal contacts with the promastigote surface. The amastigotes, in turn, laid on
cup-shaped extensions of the macrophage membrane. Later stages of the
phagocytosis are characterized by progressive and complete engulfment of both
promastigotes and amastigotes.
PMID- 10691340
TI - Nuclear industry family study:methods and description of a United Kingdom study
linking occupational information held by employers to reproduction and child
health.
AB - OBJECTIVE: To describe the methods used in the nuclear industry family study for
which a comprehensive database has been assembled that links employment in the
nuclear industry and dosimetry records to information on employees' reproductive
health and the health of their children. To discuss the response rates and
characteristics of the study population. METHODS: Occupational cohort design
leading to a retrospective cohort study of reproductive outcomes reported by 46
396 current and former employees of both sexes in the nuclear industry. Employees
of nuclear establishments in the United Kingdom operated by the Atomic Energy
Authority, the Atomic Weapons Establishment, and British Nuclear Fuels were
surveyed with postal questionnaires ot collect information on pregnancies,
children,and periods of infertility. Information on employment and monitoring for
ionising radiation was supplied by the employing nuclear authority and was linked
to pregnancies and periods of infertility with unique personal identification
numbers. RESULTS: The design and completion of this study resulted in high
quality data on a representative population of the Atomic Energy Authority,
Atomic Weapons Establishment, and British Nuclear Fuels workforces. The response
to the survey was extremely good (82% for male workers and 88% for female
workers, excluding undelivered questionnaires), and a unique relational database
has been created which will enable infertility, pregnancy, and child health
outcomes to be examined with respect to the employment and radiation monitoring
characteristics of parents. CONCLUSION: This is the first United Kingdom study to
link detailed reproductive history data to occupational information held by
employers. The methods developed for the study were found to be feasible and
successful. The design can be adapted for other investigations of reproductive
hazards to men and women in the workplace and is currently in use to survey over
100 000 armed forces personnel in an investigation of reproductive outcome among
veterans of the Gulf war.
PMID- 10691342
TI - Current awareness in geriatric psychiatry.
PMID- 10691343
TI - Synthesis of (E)-9-(1-pyrenyl)-4-hydroxynon-2-enal, a fluorescent probe of the
(E)-4-hydroxynon-2-enal with retained biological properties.
AB - (E)-9-(1-pyrenyl)-4-hydroxynon-2-enal (FHNE), a fluorescent probe of (E)-4
hydroxynon-2-enal (HNE) is synthesised in seven steps and in 35% overall yield,
starting from commercially available 1-pyrencarboxyaldehyde. When incubated with
cultured HeLa cells this fluorescent probe penetrates cells and particularly
concentrates in the region surrounding the nucleus. As the parent compound, HNE
it is able to induce the activation of heat shock factor (HSF) and is able to
induce the binding of HSF to heat shock element (HSE).
PMID- 10691344
TI - Alar again: science, the media, and the public's right to know.
PMID- 10691345
TI - Transitional cell carcinoma of the bladder in a patient on clean intermittent
catheterization.
PMID- 10691346
TI - Vegans, vegetarians and BPH.
PMID- 10691347
TI - The pubofascial anchor sling procedure for recurrent genuine urinary stress
incontinence.
PMID- 10691348
TI - Extra-urethral urinary incontinence after incompetent vaginal obstetrics.
PMID- 10691349
TI - Penile surgical techniques described by Oribasius (4th century CE)
PMID- 10691350
TI - [Sampling studies in treatment follow-up. Evaluation of patient intake within the
scope of comprehensive quality management at the Alt/Neuotting District
Hospital].
PMID- 10691351
TI - [Treatment of mentally incompetent patients. Legal requirements in surgery].
PMID- 10691352
TI - [The current status of endoscopy in surgery].
PMID- 10691353
TI - [Continuous patient information during wound management].
PMID- 10691354
TI - [What is the outlook for January 1, 2000?].
PMID- 10691355
TI - [Distal radius fractures. II].
PMID- 10691356
TI - [Comment on B. Kreklau and G. Muhr: Preventive surgery on the musculoskeletal
system].
PMID- 10691357
TI - [Comment on the position paper "Transplantation surgery in visceral surgery"].
PMID- 10691358
TI - [Deviation stoma. Comment on the contribution by H. R. Roosen and R. Schissel].
PMID- 10691359
TI - [The future of medicine at the threshold of the third millennium].
PMID- 10691360
TI - A less polluting pig.
PMID- 10691361
TI - Protein protection from the sun.
PMID- 10691362
TI - NRC: not enough data.
PMID- 10691363
TI - Vitamin E vs. PCBs.
PMID- 10691364
TI - Sins of the father. Parental smoking and childhood cancer.
PMID- 10691365
TI - Catch the drift. Assessing risk from pesticide spraying.
PMID- 10691366
TI - Malformed frogs. Making the leap to humans.
PMID- 10691367
TI - The complement system has associations also with glucose metabolism.
PMID- 10691368
TI - A pH-sensitive channel regulates urea access to Helicobacter pylori urease.
PMID- 10691369
TI - C. difficile epidemic raises difficult questions about antibiotic-prescribing
practices.
PMID- 10691370
TI - Early negative results not the last word on secretin/autism story.
PMID- 10691371
TI - Image of the month. Adherent, yellow exudate speckled with black spots in the
distal two thirds of the esophagus. Diagnosis: This distinctive endoscopic image
shows an acute necrotizing esophagitis, also known as the black esophagus.
PMID- 10691372
TI - Abraham Vater of the ampulla (papilla) of Vater.
PMID- 10691373
TI - Sensitivity of cold-preserved rat liver to single-pass reperfusion.
PMID- 10691374
TI - H. pylori and risk of ulcer bleeding among users of NSAIDS.
PMID- 10691375
TI - Enterokinase in cerulein pancreatitis.
PMID- 10691376
TI - Lack of effect of acid suppression therapy on gastric atrophy.
PMID- 10691377
TI - Role of the CDP-choline and the alternative pathway for phosphatidylcholine
biosynthesis.
PMID- 10691378
TI - Amino acid sequence of EC2 domain in CD81 is highly conserved in Japanese
subjects.
PMID- 10691379
TI - Lamivudine treatment for children with interferon refractory chronic hepatitis B.
PMID- 10691380
TI - Herbal products for liver diseases.
PMID- 10691381
TI - Inhibition of the cyclooxygenase/lipoxygenase pathways to improve interferon alfa
efficacy in chronic hepatitis C: a wrong track.
PMID- 10691382
TI - Immune therapy of hepatitis B virus chronic infection.
PMID- 10691383
TI - Iron and fibrosis in nonalcoholic fatty liver disease.
PMID- 10691384
TI - Gastroenterology on the Internet--I.
PMID- 10691385
TI - Lung volume reduction for patients with severe COPD.
PMID- 10691386
TI - Selective decontamination of the digestive tract in critically ill patients.
PMID- 10691387
TI - Decompressive craniectomy to treat intracranial hypertension in head injury
patients.
PMID- 10691388
TI - Alcohol, thiamin and fibromyalgia.
PMID- 10691389
TI - The power of grassroots commitment.
PMID- 10691391
TI - Eight faces of validity.
PMID- 10691390
TI - Folic acid and Down syndrome.
PMID- 10691392
TI - Surgical-site complications associated with a morphine nerve paste used for
postoperative pain control after laminectomy.
PMID- 10691393
TI - Proceedings of the 4th International Conference of the Hospital Infection
Society. Edinburgh, 13-17 September 1998.
PMID- 10691394
TI - Risk aversion and costs: a comparison of family physicians and general
internists.
PMID- 10691395
TI - [Resection of osteoid osteoma].
PMID- 10691396
TI - [Clinical medical surveillance strategy of persons exposed to asbestos. French
Occupational Health Society, Society of French-speaking Pneumologists, Society of
Thoracic Imaging].
PMID- 10691397
TI - [Case no.1. Diagnosis: Balo concentric sclerosis].
PMID- 10691398
TI - [Case no. 2. Congenital portocaval anastomosis].
PMID- 10691399
TI - [Case no.3. Diagnosis: cervical vertebral calcinosis associated with systemic
scleroderma].
PMID- 10691400
TI - [Case no. 4. Subdural sarcoma].
PMID- 10691402
TI - [Case no. 1. Diagnosis: mucoepidermoid carcinoma of the left bronchus].
PMID- 10691401
TI - [Case no. 5. Diagnosis: dural arteriovenous fistula of the posterior fossa with
perimedullary venous drainage].
PMID- 10691403
TI - [Case no. 2. Diagnosis: ileal, retroperitoneal and pulmonary metastases from a
malignant melanoma].
PMID- 10691404
TI - [Case no. 3. Diagnosis: urinoma].
PMID- 10691405
TI - [Case no. 4. Diagnosis: bilateral breast lymphoma type B].
PMID- 10691406
TI - [Case no. 5. Diagnosis: disseminated pulmonary and medullary tuberculosis in
chronic renal insufficiency with pathologic signs associated with secondary
hyperparathyroidism].
PMID- 10691407
TI - [Case no. 6. Diagnosis: multiple endocrine neoplasia type 1].
PMID- 10691408
TI - [Case no. 7. Diagnosis: acute retrococecal appendicitis].
PMID- 10691409
TI - [Case no. 8. Diagnosis: esophageal metastasis from treated breast cancer
(infiltrating lobular type)].
PMID- 10691410
TI - Risk of multisystem disease in isolated ocular angioma (haemangioblastoma)
PMID- 10691411
TI - Confirmation of the assignment of the Sanjad-Sakati (congenital
hypoparathyroidism) syndrome (OMIM 241410) locus to chromosome lq42-43.
PMID- 10691412
TI - Molecular diagnosis is important to confirm suspected pseudoachondroplasia.
PMID- 10691413
TI - Biallelic expression of IGFBP1 and IGFBP3, two candidate genes for the Silver
Russell syndrome.
PMID- 10691414
TI - Mutational analysis of the human pancreatic secretory trypsin inhibitor (PSTI)
gene in hereditary and sporadic chronic pancreatitis.
PMID- 10691415
TI - A case of inv dup(8p) with early onset breast cancer.
PMID- 10691416
TI - Appendiceal carcinoma complicating adenomatous polyposis in a young woman with a
de novo constitutional reciprocal translocation t(5;8)(q22;p23.1)
PMID- 10691417
TI - NF2 gene deletion in a family with a mild phenotype.
PMID- 10691418
TI - Absence of fragile X syndrome in Nova Scotia.
PMID- 10691419
TI - The mystery of addiction.
PMID- 10691420
TI - The globalization of Chinese medicine.
PMID- 10691421
TI - The development of dentistry, 1000-2000.
PMID- 10691422
TI - Crowning achievements in dentistry.
PMID- 10691423
TI - Diagnosis: the doctor and the urine glass.
PMID- 10691424
TI - Medical diagnosis in the Internet age.
PMID- 10691425
TI - Disease and stigma.
PMID- 10691426
TI - The "geneticisation" of disease stigma.
PMID- 10691427
TI - Doctors' status: changes in the past millennium.
PMID- 10691428
TI - Status of the doctor--present and future.
PMID- 10691429
TI - Economic development and disease.
PMID- 10691430
TI - Addiction and the truth in magic realism.
PMID- 10691431
TI - Economics and health.
PMID- 10691432
TI - Early observations of genetic diseases.
PMID- 10691433
TI - Gene therapy and beyond.
PMID- 10691434
TI - Magic and the origins of modern science.
PMID- 10691435
TI - Traditional healing practice using medicinal herbs.
PMID- 10691436
TI - Health care in hospitals: the past 1000 years.
PMID- 10691437
TI - Hospitals in developing countries: a weak link in a weak chain.
PMID- 10691438
TI - Child mortality: social and medical responses.
PMID- 10691439
TI - Evidence-based and value-based paediatrics.
PMID- 10691440
TI - Influenza--a continuing detective story.
PMID- 10691441
TI - Ageing: old visions, new times?
PMID- 10691442
TI - Prevention and control of influenza.
PMID- 10691443
TI - The long road to malaria eradication.
PMID- 10691444
TI - Antimalarial drug policy: making systematic change.
PMID- 10691445
TI - The history of medical teaching.
PMID- 10691446
TI - Medical education for the doctors of tomorrow.
PMID- 10691447
TI - Nine centuries of cranial surgery.
PMID- 10691448
TI - The next 100 years of neurosurgery.
PMID- 10691449
TI - The Potato Eaters.
PMID- 10691450
TI - Food and nutrition for all.
PMID- 10691451
TI - A millennium of obstetrics and gynaecology.
PMID- 10691452
TI - Ageing in the 21st century.
PMID- 10691453
TI - The brave new world of making babies.
PMID- 10691454
TI - Origin and evolution of medical oncology.
PMID- 10691455
TI - The future of oncology: more of the same?
PMID- 10691456
TI - Old news in ophthalmology.
PMID- 10691457
TI - A mission for vision.
PMID- 10691458
TI - "Orthopaedics"--before and after the word.
PMID- 10691459
TI - Computer-assisted tools and interventional technologies.
PMID- 10691461
TI - Today's patient: passive or involved?
PMID- 10691460
TI - Subjectivity and ethics: the patient.
PMID- 10691462
TI - Perception of disease and its meanings.
PMID- 10691463
TI - The hope of anaesthesia.
PMID- 10691464
TI - The concept of disease: from Newton back to Aristotle.
PMID- 10691465
TI - "Pharmacocentricity": from elixirs to magic bullets.
PMID- 10691466
TI - New directions in pharmacology.
PMID- 10691468
TI - Can plagues be predicted, prevented?
PMID- 10691467
TI - Poisoners and "plague-smearers".
PMID- 10691469
TI - The "alter ego" in psychiatry.
PMID- 10691470
TI - Changing boundaries in psychiatry.
PMID- 10691471
TI - Transformations in social medicine.
PMID- 10691473
TI - Trials and errors in clinical research.
PMID- 10691472
TI - Public health: the outlook for contrasting populations.
PMID- 10691474
TI - The two pillars of anaesthesia.
PMID- 10691475
TI - Biomedical research: crossing the 1 s Rubicon.
PMID- 10691476
TI - The wages of sin.
PMID- 10691477
TI - The staying power of sexually transmitted diseases.
PMID- 10691478
TI - Pandora's box opened: 1000 years of war and disease.
PMID- 10691479
TI - Weapons for the future.
PMID- 10691480
TI - Women and doctors in medicine.
PMID- 10691481
TI - Finale.
PMID- 10691482
TI - The changing heart.
PMID- 10691483
TI - Cardiology: where to go from here?
PMID- 10691484
TI - The past 1000 years of Chinese medicine.
PMID- 10691485
TI - Domestic violence.
PMID- 10691486
TI - Domestic violence.
PMID- 10691487
TI - Domestic violence.
PMID- 10691488
TI - Domestic violence.
PMID- 10691489
TI - The long-QT syndrome.
PMID- 10691490
TI - AIDS in the 21st century.
PMID- 10691491
TI - AIDS in the 21st century.
PMID- 10691492
TI - Racial differences in the treatment of early-stage lung cancer.
PMID- 10691493
TI - Racial differences in the treatment of early-stage lung cancer.
PMID- 10691494
TI - Racial differences in the treatment of early-stage lung cancer.
PMID- 10691495
TI - The unintended consequences of measuring quality on the quality of medical care.
PMID- 10691496
TI - The unintended consequences of measuring quality on the quality of medical care.
PMID- 10691497
TI - The unintended consequences of measuring quality on the quality of medical care.
PMID- 10691498
TI - Diagnosis of scombroid poisoning by measurement of plasma histamine.
PMID- 10691499
TI - Disclosure of authors' conflicts of interest: a follow-up.
PMID- 10691500
TI - Behcet's disease.
PMID- 10691501
TI - Behcet's disease.
PMID- 10691502
TI - Behcet's disease.
PMID- 10691503
TI - Behcet's disease.
PMID- 10691504
TI - Behcet's disease.
PMID- 10691505
TI - Behcet's disease.
PMID- 10691506
TI - Absence of benefit of eradicating Helicobacter pylori in patients with nonulcer
dyspepsia.
PMID- 10691507
TI - Absence of benefit of eradicating Helicobacter pylori in patients with nonulcer
dyspepsia.
PMID- 10691508
TI - Electrocardiographic artifact.
PMID- 10691509
TI - Electrocardiographic artifact.
PMID- 10691510
TI - Electrocardiographic artifact.
PMID- 10691511
TI - Electrocardiographic artifact.
PMID- 10691512
TI - Lamivudine for the treatment of chronic hepatitis B.
PMID- 10691513
TI - Myocardial infarction in a patient with hypertrophic cardiomyopathy.
PMID- 10691514
TI - Canadian biomedical collaboration keeps on growing.
PMID- 10691515
TI - [Accidental fall of an infant from a baby carrier].
PMID- 10691516
TI - Hemolytic uremic syndrome associated with invasive Streptococcus pneumoniae
infection.
PMID- 10691517
TI - Urinary tract infection guidelines questioned.
PMID- 10691518
TI - Urinary tract infection guidelines questioned.
PMID- 10691519
TI - Urinary tract infection guidelines questioned.
PMID- 10691520
TI - Urinary tract infection guidelines questioned.
PMID- 10691521
TI - Benign enlargement of the mandibulofacial lymph node.
PMID- 10691522
TI - Response to the joint statement on HIV screening.
PMID- 10691524
TI - Programmed proteolysis and the control of cell division. A discussion meeting,
November 4-5, 1998.
PMID- 10691523
TI - Article captures the essence and meaning of alopecia.
PMID- 10691525
TI - 21st Annual Winter Neuropeptide Conference. Breckenridge, Colorado, USA. January
29-February 1, 2000. Abstracts.
PMID- 10691526
TI - 2001 budget. Clinton seeks 'major lift' in U.S. research programs.
PMID- 10691527
TI - Patents. Company gets rights to cloned human embryos.
PMID- 10691528
TI - Cell biology. Generating new yeast prions.
PMID- 10691529
TI - Scientific publishing. Publishers discuss European e-print site.
PMID- 10691530
TI - Restoration ecology. Bringing the Salton Sea back to life.
PMID- 10691531
TI - FDA halts all gene therapy trials at Penn.
PMID- 10691532
TI - Intellectual property. NIH cuts deal on use of OncoMouse.
PMID- 10691533
TI - Pasteur Institute. New chief promises renewal and openness.
PMID- 10691534
TI - Meeting. Society for Integrative and Comparative Biology. An integrative science
finds a home.
PMID- 10691535
TI - Restoration ecology. Returning America's forests to their 'natural' roots.
PMID- 10691536
TI - Unseemly competition.
PMID- 10691537
TI - E-knowledge hullabaloo--or when will the glass spill over?
PMID- 10691538
TI - Gene therapy on trial.
PMID- 10691539
TI - Sickle cell anemia therapy: progress since Pauling.
PMID- 10691540
TI - Oversight mechanisms for clinical research.
PMID- 10691541
TI - Perspectives: epidemiology. Simple rules with complex dynamics.
PMID- 10691542
TI - HIV infection and dementia.
PMID- 10691543
TI - Perspectives: earth science and evolution. Genomics and the geosciences.
PMID- 10691544
TI - 2001 budget. How NSF came up with the biggest boost in history.
PMID- 10691545
TI - Biotechnology. Both sides claim victory in trade pact.
PMID- 10691546
TI - A face-off over tumor blood supply.
PMID- 10691547
TI - Plant biotechnology. Consumer power heralds hard times for researchers.
PMID- 10691548
TI - Neuroscience. Cold numbers unmake the quantum mind.
PMID- 10691549
TI - Ecology. How climate change alters rhythms of the wild.
PMID- 10691550
TI - Lunch selections expanding.
PMID- 10691551
TI - Antibiotic rotation.
PMID- 10691552
TI - Herbicide use on roundup ready crops.
PMID- 10691553
TI - Benefits of membership.
PMID- 10691554
TI - From Turin to Stockholm via St. Louis and Rio de Janeiro.
PMID- 10691555
TI - A life in science.
PMID- 10691556
TI - Perspectives: neurobiology. Regeneration in the Nogo zone.
PMID- 10691557
TI - Perspectives: drug delivery. Regulating export of ER cargo.
PMID- 10691558
TI - Perspectives: behavior. Measuring beelines to food.
PMID- 10691559
TI - Perspectives: biosynthetic pathways. Biosynthesis meets bioinformatics.
PMID- 10691560
TI - HIV transmission. AIDS researchers look to Africa for new insights.
PMID- 10691561
TI - Scientific advice. Academies get together to tackle the big issues.
PMID- 10691562
TI - Neurobiology. A new clue to how alcohol damages brains.
PMID- 10691563
TI - Stem cells. Wisconsin to distribute embryonic cell lines.
PMID- 10691564
TI - Stem cells. Report would open up research in Japan.
PMID- 10691565
TI - Human genetics. Start-up claims piece of Iceland gene pie.
PMID- 10691567
TI - Plan to reduce number of new grants tempers enthusiasm for NIH budget hike.
PMID- 10691566
TI - Balancing the science budget.
PMID- 10691568
TI - AIDS research. Vaccine studies stymied by shortage of animals.
PMID- 10691569
TI - Veterinary perspective on gene therapy with adenoviruses.
PMID- 10691570
TI - Luzia is not alone.
PMID- 10691571
TI - Economics of bushmeat.
PMID- 10691572
TI - Perspectives: signal transduction. Signals to move cells.
PMID- 10691573
TI - Perspectives: evolution. Is bigger better in cricket?
PMID- 10691574
TI - Proceedings of the 11th Japanese-German Cooperative Symposium on Protozoan
Diseases. August 29-31, 1998.
PMID- 10691575
TI - Morphology of Toxoplasma tachyzoites in the brain of an AIDS patient.
PMID- 10691576
TI - [Advance directives: words pass, writing remains?].
PMID- 10691577
TI - [Tumescence local anesthesia. Interview with Prof. Dr. Werner Mang on the
developmental state of this new local anesthesia method. Interview by Werner
Rossling/Hinrich Kuster].
PMID- 10691578
TI - [Gene therapy. Basis and preliminary therapy concept for the treatment of
malignant diseases of the urogenital system].
PMID- 10691579
TI - [Therapy of common PCA (acinar adenocarcinoma). German Society of Urology].
PMID- 10691580
TI - [Research support for urology. A guideline--II. German Society of Urology].
PMID- 10691581
TI - [Aleksandr Vasil'evich Mel'nikov (1889-1958)].
PMID- 10691582
TI - Inhaled corticosteroids?
PMID- 10691583
TI - Dizziness among older adults: a possible geriatric syndrome.
AB - BACKGROUND: In previous studies of dizziness, the prevalence of specific causes
has varied widely and either no or multiple causes have been identified.
Dizziness might be better considered a geriatric syndrome that results from
impairment or disease in multiple systems. OBJECTIVE: To determine the
predisposing characteristics and situational factors associated with dizziness.
DESIGN: Population-based, cross-sectional study. SETTING: Community.
PARTICIPANTS: Probability sample of 1087 community-living persons in New Haven,
Connecticut, who were at least 72 years of age. MEASUREMENTS: Episodes of
dizziness that occurred for at least 1 month; manifestations of dizziness; and
predisposing demographic, medical, neurologic, sensory, and psychological
characteristics. RESULTS: 261 participants (24%) reported dizziness; 56% of dizzy
persons described several sensations and 74% reported several triggering
activities. The adjusted relative risks for characteristics associated with
dizziness were 1.69 (95% CI, 1.24 to 2.30) for anxiety, 1.36 (CI, 1.02 to 1.80)
for depressive symptoms, 1.27 (CI, 0.99 to 1.63) for impaired hearing, 1.30 (CI,
1.01 to 1.68) for five or more medications, 1.31 (CI, 0.92 to 1.87) for postural
hypotension, 1.34 (CI, 0.95 to 1.90) for impaired balance, and 1.31 (CI, 1.00 to
1.71) for past myocardial infarction. The adjusted relative risk for dizziness
was 1.38 (CI, 1.27 to 1.49) for each additional characteristic. CONCLUSIONS: The
association among characteristics in multiple domains (cardiovascular,
neurologic, sensory, psychological, and medication-related) and dizziness,
coupled with the multiplicity of sensations and triggering activities, suggests
that dizziness may be a geriatric syndrome, similar to delirium and falling. If
so, an impairment reduction strategy, proven effective for other geriatric
syndromes, may be effective in reducing the symptoms and disabilities associated
with dizziness.
PMID- 10691584
TI - Low fractional calcium absorption increases the risk for hip fracture in women
with low calcium intake. Study of Osteoporotic Fractures Research Group.
AB - BACKGROUND: Decreased ability to absorb calcium with age limits adaptation to low
calcium intake and is thought to lead to secondary hyperparathyroidism and
increased risk for hip and other fractures. However, the associations between
fractional calcium absorption, dietary calcium intake, and risk for fracture have
never been studied. OBJECTIVE: To determine whether low fractional calcium
absorption in women with low calcium intake increases the risk for subsequent hip
and other nonspine fractures. DESIGN: Prospective cohort study. SETTING: Four
clinical centers in Baltimore County, Maryland; Portland, Oregon; Minneapolis,
Minnesota; and the Monongahela Valley, Pennsylvania. PARTICIPANTS: 5452 nonblack
women 69 years of age or older participating in the fourth examination of the
Study of Osteoporotic Fractures. MEASUREMENTS: Fractional calcium absorption was
measured by using a 3-hour single isotope (45Ca) technique. Incident fractures
were identified prospectively and were confirmed by radiographic report. RESULTS:
During an average of 4.8 years, 729 women (13%) experienced at least one nonspine
fracture; 153 of these women had hip fractures. After adjustment for age, women
with lower fractional calcium absorption were at increased risk for hip fracture
(relative risk per 1-SD [7.7%] decrease in fractional calcium absorption, 1.24
[95% CI, 1.05 to 1.48]). Women with low fractional calcium absorption and low
calcium intake were at greatest risk for subsequent hip fracture; among women
whose dietary calcium intake was less than 400 mg/d, those who had fractional
calcium absorption at or below the median value of 32.3% had a 2.5-fold (CI, 1.29
fold to 4.69-fold) increase in risk for hip fracture compared with those who had
greater absorption efficiency. Fractional calcium absorption was not related to
risk for other nonspine fractures (relative risk per 1-SD [7.7%] decrease in
fractional calcium absorption, 1.05 [CI, 0.96 to 1.14]). CONCLUSIONS: In elderly
women, low fractional calcium absorption in the setting of low calcium intake
increases the risk for hip fracture. Our findings support the hypothesis of type
II osteoporosis, which postulates that decreased calcium absorption is an
important risk factor for hip fracture in older persons.
PMID- 10691585
TI - Effects of fexofenadine, diphenhydramine, and alcohol on driving performance. A
randomized, placebo-controlled trial in the Iowa driving simulator.
AB - BACKGROUND: Sedating antihistamines may impair driving performance as seriously
as alcohol. OBJECTIVE: To compare the effects of fexofenadine, diphenhydramine,
alcohol, and placebo on driving performance. DESIGN: Randomized, double-blind,
double-dummy, four-treatment, four-period crossover trial. SETTING: The Iowa
Driving Simulator. PARTICIPANTS: 40 licensed drivers with seasonal allergic
rhinitis who were 25 to 44 years of age. INTERVENTION: One dose of fexofenadine
(60 mg), diphenhydramine (50 mg), alcohol (approximately 0.1% blood alcohol
concentration), or placebo, given at weekly intervals before participants drove
for 1 hour in the Iowa Driving Simulator. MEASUREMENTS: The primary end point was
coherence, a continuous measure of participants' ability to match the varying
speed of a vehicle that they were following. Secondary end points were drowsiness
and other driving measures, including lane keeping and response to a vehicle that
unexpectedly blocked the lane ahead. RESULTS: Participants had significantly
better coherence after taking alcohol or fexofenadine than after taking
diphenhydramine. Lane keeping (steering instability and crossing the center line)
was impaired after alcohol and diphenhydramine use compared with fexofenadine
use. Mean response time to the blocking vehicle was slowest after alcohol use
(2.21 seconds) compared with fexofenadine use (1.95 seconds). Self-reported
drowsiness did not predict lack of coherence and was weakly associated with
minimum following distance, steering instability, and leftlane excursion.
CONCLUSIONS: Participants had similar performance when treated with fexofenadine
or placebo. After alcohol use, participants performed the primary task well but
not the secondary tasks; as a result, overall driving performance was poorer.
After participants took diphenhydramine, driving performance was poorest,
indicating that diphenhydramine had a greater impact on driving than alcohol did.
Drowsiness ratings were not a good predictor of impairment, suggesting that
drivers cannot use drowsiness to indicate when they should not drive.
PMID- 10691586
TI - Recombinant human thrombopoietin attenuates carboplatin-induced severe
thrombocytopenia and the need for platelet transfusions in patients with
gynecologic cancer.
AB - BACKGROUND: Thrombocytopenia is a significant problem in the treatment of cancer.
OBJECTIVE: To assess the clinical safety of therapy with recombinant human
thrombopoietin (rhTPO) and its ability to ameliorate chemotherapy-induced severe
thrombocytopenia. DESIGN: Phase I/II clinical cohort study. SETTING: The
University of Texas M.D. Anderson Cancer Center, Houston, Texas. PATIENTS: 29
patients with gynecologic cancer. INTERVENTION: Recombinant human thrombopoietin
was given before chemotherapy and after a second cycle of carboplatin therapy.
MEASUREMENTS: Peripheral blood counts and platelet transfusions. RESULTS:
Administration of rhTPO after chemotherapy significantly reduced the degree and
duration of thrombocytopenia and enhanced platelet recovery. In patients who
received the optimal biological dose of rhTPO (1.2 microg/kg of body weight) in
cycle 2 (carboplatin plus rhTPO), the mean platelet count nadir was higher
(44x10(9) cells/L and 20x10(9) cells/L; P = 0.002) and the duration of
thrombocytopenia was shorter (days with a platelet count <20x10(9) cells/L, 1 and
4 [P = 0.002]; days with a platelet count <50x10(9) cells/L, 4 and 7 [P = 0.006])
than in cycle 1 (carboplatin only). The need for platelet transfusion in this
group was reduced from 75% of patients in cycle 1 to 25% of patients in cycle 2
(P = 0.013). CONCLUSIONS: Therapy with rhTPO seems to be safe and may attenuate
chemotherapy-induced severe thrombocytopenia and reduce the need for platelet
transfusions.
PMID- 10691587
TI - Increased susceptibility to pulmonary emphysema among HIV-seropositive smokers.
AB - BACKGROUND: Previous uncontrolled reports have suggested that HIV-seropositive
persons develop an accelerated form of emphysema. OBJECTIVE: To characterize the
risk for emphysema in a stable HIV-seropositive outpatient population. DESIGN:
Controlled, cross-sectional analysis. SETTING: Midwestern urban community.
PARTICIPANTS: HIV-seropositive persons (n = 114) without AIDS-related pulmonary
complications and HIV-seronegative controls (n = 44), matched for age and smoking
history. MEASUREMENTS: Measurement of pulmonary function, bronchoalveolar lavage,
and high-resolution computed tomography of the chest. RESULTS: The incidence of
emphysema was 15% (17 of 114) in the HIV-seropositive group compared with 2% (1
of 44) in the HIV-seronegative group (P = 0.025). The incidence of emphysema in
participants with a smoking history of 12 pack-years or greater was 37% (14 of 38
persons) in the HIV-seropositive group compared with 0% (0 of 14 persons) in the
HIV-seronegative group (P = 0.011). The percentage of cytotoxic lymphocytes in
lavage fluid was much higher in HIV-seropositive smokers with emphysema.
CONCLUSIONS: Infection with HIV accelerates the onset of smoking-induced
emphysema. The results of this study support the emerging concept that cytotoxic
lymphocytes may have an important role in emphysema pathogenesis.
PMID- 10691588
TI - Developing and implementing computerized protocols for standardization of
clinical decisions.
AB - Humans have only a limited ability to incorporate information in decision making.
In certain situations, the mismatch between this limitation and the availability
of extensive information contributes to the varying performance and high error
rate of clinical decision makers. Variation in clinical practice is due in part
to clinicians' poor compliance with guidelines and recommended therapies. The use
of decision-support tools is a response to both the information revolution and
poor compliance. Computerized protocols used to deliver decision support can be
configured to contain much more detail than textual guidelines or paper-based
flow diagrams. Such protocols can generate patient-specific instructions for
therapy that can be carried out with little interclinician variability; however,
clinicians must be willing to modify personal styles of clinical management.
Protocols need not be perfect. Several defensible and reasonable approaches are
available for clinical problems. However, one of these reasonable approaches must
be chosen and incorporated into the protocol to promote consistent clinical
decisions. This reasoning is the basis of an explicit method of decision support
that allows the rigorous evaluation of interventions, including use of the
protocols themselves. Computerized protocols for mechanical ventilation and
management of intravenous fluid and hemodynamic factors in patients with the
acute respiratory distress syndrome provide case studies for this discussion.
PMID- 10691589
TI - Update in hospital medicine.
PMID- 10691590
TI - Prevention of intravascular catheter-related infections.
AB - PURPOSE: To review the literature on prevention of intravascular catheter-related
infections. DATA SOURCES: The MEDLINE database, conference proceedings, and
bibliographies of review articles and book chapters were searched for relevant
articles. Primary authors were contacted directly if data were incomplete. STUDY
SELECTION: Studies met the following criteria unless otherwise stated: Trials
were prospective and randomized; catheters were inserted into new sites, not into
old sites over guidewires; catheter cultures were done by using semi-quantitative
or quantitative methods; and, for prospective studies, catheter-related
bloodstream infection was confirmed by microbial growth from percutaneously drawn
blood cultures that matched catheter cultures. DATA EXTRACTION: Data on
population, methods, preventive strategy, and outcome (measured as catheter
related bloodstream infections) were gathered. The quality of the data was graded
by using preestablished criteria. DATA SYNTHESIS: The recommended preventive
strategies with the strongest supportive evidence are full barrier precautions
during central venous catheter insertion; subcutaneous tunneling short-term
catheters inserted in the internal jugular or femoral veins when catheters are
not used for drawing blood; contamination shields for pulmonary artery catheters;
povidone-iodine ointment applied to insertion sites of hemodialysis catheters;
specialized nursing teams caring for patients with short-term peripheral venous
catheters, especially at institutions with a high incidence of catheter-related
infection; no routine replacement of central venous catheters; antiseptic
chamberfilled hub or hub-protective antiseptic sponge for central venous
catheters; and use of chlorhexidine-silver sulfadiazine-impregnated or
minocycline-rifampin-impregnated short-term central venous catheters if the rate
of infection is high despite adherence to other strategies that do not
incorporate antimicrobial agents (for example, maximal barrier precautions).
CONCLUSIONS: Simple interventions can reduce the risk for serious catheter
related infection. Adequately powered randomized trials are needed.
PMID- 10691591
TI - Occam's razor, geriatric syndromes, and the dizzy patient.
PMID- 10691592
TI - Nonsedating antihistamines should be preferred over sedating antihistamines in
patients who drive.
PMID- 10691593
TI - Responding to intractable terminal suffering: the role of terminal sedation and
voluntary refusal of food and fluids. ACP-ASIM End-of-Life Care Consensus Panel.
American College of Physicians-American Society of Internal Medicine.
AB - When provided by a skilled, multidisciplinary team, palliative care is highly
effective at addressing the physical, psychological, social, and spiritual needs
of dying patients and their families. However, some patients who have witnessed
harsh death want reassurance that they can escape if their suffering becomes
intolerable. In addition, a small percentage of terminally ill patients receiving
comprehensive care reach a point at which their suffering becomes severe and
unacceptable despite unrestrained palliative efforts; some of these patients
request that death be hastened. This paper presents terminal sedation and
voluntary refusal of hydration and nutrition as potential last resorts that can
be used to address the needs of such patients. These two practices allow
clinicians to address a much wider range of intractable end-of-life suffering
than physician-assisted suicide (even if it were legal) and can also provide
alternatives for patients, families, and clinicians who are morally opposed to
physician-assisted suicide. This paper will define the two practices, distinguish
them from more standard palliative care interventions and from physician-assisted
suicide, illustrate them with a real clinical scenario, provide potential
guidelines and practicalities, and explore their moral and legal status. Although
medicine cannot sanitize dying or provide perfect answers for all challenging end
of-life clinical problems, terminal sedation and voluntary refusal of hydration
and nutrition substantially increase patients' choices at this inherently
challenging time.
PMID- 10691594
TI - Trends in tuberculosis transmission.
PMID- 10691595
TI - Mycophenolate mofetil-induced dyshidrotic eczema.
PMID- 10691596
TI - Venlafaxine-associated hepatitis.
PMID- 10691597
TI - Hydroxyurea-induced leg ulcers treated with Apligraf.
PMID- 10691598
TI - Importance of proper identification of stinging insects.
PMID- 10691599
TI - Understanding adherence to HIV medication.
PMID- 10691600
TI - Use of statins and fibrates in hyperlipidemic patients with neuromuscular
disorders.
PMID- 10691602
TI - Editor's change of address
PMID- 10691601
TI - Richard Lower: anatomist and physiologist.
PMID- 10691603
TI - Biotransformation of beta-myrcene by the larvae of common cutworm (Spodoptera
litura).
AB - beta-Myrcene was mixed in an artificial diet at a concentration of 1 mg/g of
diet, and the diet was fed to the last instar larvae of common cutworm
(Spodoptera litura). Metabolites were recovered from frass and analyzed
spectroscopically. beta-Myrcene was transformed mainly to myrcene-3(10)-glycol
and myrcene-1,2-glycol. Each pair of double bonds of beta-myrcene was converted
to the corresponding diol by oxidation, respectively. The 3,10- and 1,2-double
bonds of beta-myrcene were respectively oxidized.
PMID- 10691604
TI - Determination of polycyclic aromatic hydrocarbons in commercial liquid smoke
flavorings of different compositions by gas chromatography-mass spectrometry.
AB - The presence of polycyclic aromatic hydrocarbons (PAHs) in five commercial liquid
smoke flavorings, used in the European food industry, was studied. The samples
were subjected to an alkaline treatment, extracted with cyclohexane, cleaned up
by means of solid-phase extraction tubes, and analyzed by gas chromatography-mass
spectrometry. Three different procedures for the cleanup were tested. The results
revealed the presence of 34 PAHs, some of them with methyl substituents. In all
cases, the concentrations of compounds of low molecular weight were much higher
than those of high molecular weight. Relationships between smoke flavoring
compositions and PAH levels were also studied. Three of the samples contained
high levels of both total and carcinogenic PAHs. Benzo[a]pyrene was also detected
in these three samples, but its concentration did not exceed the 10 microg/kg
level fixed by the FAO/WHO. Finally, a relation was found, first between the
concentrations of total carcinogenic PAHs and benzo[a]pyrene and also between the
concentrations of pyrene and benzo[a]pyrene. The latter ratio reveals that pyrene
concentration could be very useful in predicting the level of benzo[a]pyrene and,
consequently, in estimating the carcinogenicity arising from the presence of
benzo[a]pyrene and other carcinogenic PAHs.
PMID- 10691605
TI - Product and redox potential analysis of sauerkraut fermentation.
AB - The relationships between the redox potential of the brine, during fermentation
of white cabbage into sauerkraut of two early and two late fermentation
processes, and the changes in the amount of sugars, organic acids, the redox
potential of the brine and of the ascorbic acid redox couple, and pH are
described. The trend in the change of the redox potential of the brine is the
same for all four fermentation processes studied. In the first phase a sharp
decrease in redox potential is followed by an increase in redox potential. In the
second phase the redox potential is rather constant. This second phase is
followed by another decrease in redox potential, which stabilizes at a minimum
value, the third phase. It was observed that sugar fermentation and acid
production mainly took place during the first and third phases, probably
representing, respectively, the heterogeneous and homogeneous fermentation
processes.
PMID- 10691606
TI - Antioxidant activity in fruits and leaves of blackberry, raspberry, and
strawberry varies with cultivar and developmental stage.
AB - Fruits and leaves from different cultivars of thornless blackberry (Rubus sp.),
red raspberry (Rubus idaeus L.), black raspberry (Rubus occidentalis L.), and
strawberry (Fragaria x ananassa D.) plants were analyzed for total antioxidant
capacity (oxygen radical absorbance capacity, ORAC) and total phenolic content.
In addition, fruits were analyzed for total anthocyanin content. Blackberries and
strawberries had the highest ORAC values during the green stages, whereas red
raspberries had the highest ORAC activity at the ripe stage. Total anthocyanin
content increased with maturity for all three species of fruits. Compared with
fruits, leaves were found to have higher ORAC values. In fruits, ORAC values
ranged from 7.8 to 33.7 micromol of Trolox equivalents (TE)/g of fresh berries
(35. 0-162.1 micromol of TE/g of dry matter), whereas in leaves, ORAC values
ranged from 69.7 to 182.2 micromol of TE/g of fresh leaves (205.0-728.8 micromol
of TE/g of dry matter). As the leaves become older, the ORAC values and total
phenolic contents decreased. The results showed a linear correlation between
total phenolic content and ORAC activity for fruits and leaves. For ripe berries,
a linear relationship existed between ORAC values and anthocyanin content. Of the
ripe fruits tested, on the basis of wet weight of fruit, cv. Jewel black
raspberry and blackberries may be the richest source for antioxidants. On the
basis of the dry weight of fruit, strawberries had the highest ORAC activity
followed by black raspberries (cv. Jewel), blackberries, and red raspberries.
PMID- 10691607
TI - Low-density lipoprotein antioxidant activity of phenolic compounds and polyphenol
oxidase activity in selected clingstone peach cultivars.
AB - The antioxidant potential of eight clingstone peach cultivars was investigated by
determining phenolic compounds and inhibition of low-density lipoprotein (LDL)
oxidation. Cultivars low in polyphenol oxidase (PPO) were also selected to
minimize enzymatic browning. Inhibition of LDL oxidation varied from 17.0 to
37.1% in peach flesh extract, from 15.2 to 49.8% in whole peach extract, and from
18.2 to 48.1% in peel extract. Total phenols were 432.8-768.1 mg/kg in flesh
extract, 483.3-803.0 mg/kg in whole extract, and 910.9-1922.9 mg/kg in peel
extract. The correlation coefficient between relative LDL antioxidant activity
and concentration of total phenols was 0.76. Peel PPO activity was higher than
flesh activity in most cultivars. The lowest PPO and specific activities were
found in the Walgant cultivar, followed by Kakamas and 18-8-23. These three
cultivars combine the desirable characteristics of strong antioxidant activity,
low PPO activity, and lower susceptibility to browning reactions.
PMID- 10691608
TI - Transglycosylation of neohesperidin dihydrochalcone by Bacillus
stearothermophilus maltogenic amylase.
AB - Neohesperidin dihydrochalcone (NHDC), a sweet compound derived from citrus
fruits, was modified to a series of its oligosaccharides by transglycosylation
activity of Bacillus stearothermophilus maltogenic amylase (BSMA). Maltotriose as
a donor was reacted with NHDC as an acceptor to glycosylate for the purpose of
increasing the solubility of NHDC. Maltosyl-NHDC was a major transglycosylation
product among the several transfer products by TLC analysis. The structure of the
major transglycosylation product was determined to be maltosyl-alpha-(1,6)
neohesperidin dihydrochalcone by MALDI-TOF/MS and (1)H and (13)C NMR. Maltosyl
NHDC was 700 times more soluble in water and 7 times less sweet than NHDC.
PMID- 10691609
TI - Selectivity of celite-immobilized patatin (lipid acyl hydrolase) from potato
(Solanum tuberosum L.) tubers in esterification reactions As influenced by water
activity and glycerol analogues as alcohol acceptors.
AB - Lipid acyl hydrolase (LAH; patatin) was purified from potato tubers by ammonium
sulfate fractionation followed by anion-exchange and affinity chromatography. The
major protein band of 40-43 kDa on SDS-PAGE appeared to be patatin, and it
stained positive for lipase activity on native PAGE. Selectivity of a Celite
immobilized potato LAH in esterification reactions with n-acyl fatty acids (FA;
C4, C6, C8, C10, C12, C14, C16, and C18) and alcohol acceptors (n-propanol, 2
propanol, 1,3-propanediol, and glycerol; 1,2-propanediol was not sufficiently
reactive) was studied in isooctane. Immobilized LAH was highly selective for
medium chain FAs (C8/C10) with a secondary optimum for chain lengths of C14/16.
Water activity (a(w)) influenced activity and FA selectivity of the enzyme.
Initial rates of ester synthesis were greatest at a(w) of 0.90 for all alcohol
acceptors except for glycerol, where greatest initial rates were observed at a(w)
of 0.19. Immobilized LAH preparations exhibited a bell-shape pH profile with
optimum activity at pH 6-7 for ester synthesis, and no effect of pH on FA
selectivity was observed.
PMID- 10691610
TI - Rapid separation of lysozyme from chicken egg white by reductants and thermal
treatment.
AB - Reductants (0.1-2.0% ascorbic acid, cysteine, or cystine and 0.04-1. 0% beta
mercaptoethanol) were added to 5-fold diluted, salted duck egg whites
(commercially and laboratory prepared) and fresh egg whites (chicken and duck),
and subsequently the mixtures were heated at 70 degrees C for 1-10 min. The
maximal recovery and purification fold of lysozyme obtained from fresh chicken
egg whites added with 1. 0% ascorbic acid were 78% and 2.4, respectively. Storage
tests showed that the obtained lyophilized lysozyme powder after dialysis was
stable when refrigerated at 4 degrees C for 3 months.
PMID- 10691611
TI - Temperature and exposure time during ethylene conditioning affect ripening of
Bartlett pears.
AB - Freshly harvested early- and mid-season Bartlett pears (Pyrus communis) were
treated with ethylene (air plus 10 Pa C(2)H(4)) or air at 5, 10, and 20 degrees C
for 24 and 48 h (experiment 1) and at 5 and 10 degrees C for 48, 72, and 96 h and
at 20 degrees C for 24 h (experiment 2). Following C(2)H(4) or air treatment at
different temperatures and durations, pears were transferred to 20 degrees C in
air for ripening. Bartlett pears were evaluated for firmness, color, respiration,
C(2)H(4) production, and activities of 1-aminocyclopropane-1-carboxylic acid
synthase (ACC-S) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACC-O).
Ethylene action was temperature dependent. The duration of C(2)H(4) conditioning
needed to fully induce ripening was longer at lower temperatures: 72 h at 5
degrees C, 48 h at 10 degrees C, and 24 h at 20 degrees C. Cold storage in air
for as little as 3-4 days at 5 or 10 degrees C appeared to hasten subsequent
ripening, but to a lesser extent than pears kept for 2 weeks at -1 degrees C in
air. Despite a significant increase in ACC-S activity in pears treated with
C(2)H(4) at 5 degrees C, there was not a simultaneous increase in ACC-O activity,
resulting in low C(2)H(4) production that was insufficient to generate the
threshold endogenous levels of C(2)H(4) required for ripening. Contrary to
previous findings with pears, these data indicate that ACC-O could be a rate
limiting step in C(2)H(4) biosynthesis.
PMID- 10691612
TI - Purification and characterization of a stable cysteine protease ervatamin B, with
two disulfide bridges, from the latex of Ervatamia coronaria.
AB - Latex of the medicinal plant Ervatamia coronaria was found to contain at least
three cysteine proteases with high proteolytic activity, called ervatamins. One
of these proteases, named ervatamin B, has been purified to homogeneity using ion
exchange chromatography and crystallization. The molecular mass of the enzyme was
estimated to be 26 000 Da by SDS-PAGE and gel filtration. The extinction
coefficient (epsilon(1%)(280 nm)) of the enzyme was 20.5 with 7 tryptophan and 10
tyrosine residues per molecule. The enzyme hydrolyzed denatured natural
substrates such as casein, azoalbumin, and azocasein with a high specific
activity. In addition, it showed amidolytic activity toward N-succinyl-alanine
alanine-alanine-p-nitroanilide with an apparent K(m) and K(cat) of 6.6 +/- 0.5 mM
and 1.87 x 10(2) s(-)(1), respectively. The pH optima was 6.0-6.5 with azocasein
as substrate and 7.0-7.5 with azoalbumin as substrate. The temperature optimum
was around 50-55 degrees C. The enzyme was basic with an isoelectric point of
9.35 and had no carbohydrate content. Both the proteolytic and amidolytic
activity of the enzyme was strongly inhibited by thiol-specific inhibitors.
Interestingly, the enzyme had only two disulfide bridges versus three as in most
plant cysteine proteases of the papain superfamily. The enzyme was relatively
stable toward pH, denaturants, temperature, and organic solvents. Polyclonal
antibodies raised against the pure enzyme gave a single precipitin line in
Ouchterlony's double immunodiffusion and typical color in ELISA. Other related
proteases do not cross-react with the antisera to ervatamin B showing that the
enzyme is immunologically distinct. The N-terminal sequence showed conserved
amino acid residues and considerable similarity to typical plant cysteine
proteases.
PMID- 10691613
TI - Antioxidative and anti-glycation activity of garcinol from Garcinia indica fruit
rind.
AB - Garcinol, a polyisoprenylated benzophenone derivative, was purified from Garcinia
indica fruit rind, and its antioxidative activity, chelating activity, free
radical scavenging activity, and anti-glycation activity were studied. Garcinol
exhibited moderate antioxidative activity in the micellar linoleic acid
peroxidation system and also exhibited chelating activity at almost the same
level as citrate. It also showed nearly 3 times greater DPPH (1, 1-diphenyl-2
picrylhydrazyl) free radical scavenging activity than DL-alpha-tocopherol by
weight in aqueous ethanol solution. In a phenazine methosulfate/NADH-nitroblue
tetrazolium system, garcinol exhibited superoxide anion scavenging activity and
suppressed protein glycation in a bovine serum albumin/fructose system. Thus,
garcinol might be beneficial as a potent antioxidant and a glycation inhibitor
under specified conditions.
PMID- 10691614
TI - Protein insolubilization and thiol oxidation in sulfite-treated wheat gluten
films during aging at various temperatures and relative humidities.
AB - Gluten films were prepared by casting an acidic and ethanolic solution of gluten
previously treated with sodium sulfite. The effects of sulfitolysis on proteins
were investigated by SE-HPLC and thiol/disulfide content measurements. During
sulfitolysis, insoluble glutenin macropolymer was converted into its constitutive
subunits. About 10% of gluten disulfide bonds were cleaved, of which three
fourths originated from interchain disulfide bonds. Oxidation of thiol groups
released during sulfitolysis was followed for various temperatures (T) and
relative humidities. Oxidation was shown to be a second-order rate process
occurring below the glass transition temperature (T(g)) and related to T - T(g).
Thiol oxidation ensured the formation of interchain bonds between specific
classes of gluten proteins according to an ordered process. Intrachain bonds were
also formed and through thiol/disulfide-exchange reactions were finally converted
to interchain bonds. Thus, fully oxidized gluten films had more insoluble
glutenin macropolymers than native gluten.
PMID- 10691615
TI - Development of oxidized odor and volatile aldehydes in fermented cucumber tissue
exposed to oxygen.
AB - Changes in volatile compounds in fermented cucumber tissue during exposure to
oxygen were investigated by purge and trap sampling, followed by GC-MS. Hexanal
and a series of trans unsaturated aldehydes, (E)-2-pentenal, (E)-2-hexenal, (E)-2
heptenal, and (E)-2-octenal, increased in fermented cucumber slurries exposed to
oxygen. Sensory evaluation of oxidized odor was correlated with the increase in
aldehyde concentrations. Other identified volatile components present after
fermentation did not show major changes during exposure to oxygen. There was no
decrease in the formation of aldehydes in fermented cucumber samples that were
heated to inactivate enzymes before exposure to oxygen. These results indicated
that the formation of aldehydes in oxygen was due to nonenzymatic reactions.
PMID- 10691616
TI - Orthokinetic flocculation of caseinate-stabilized emulsions: influence of calcium
concentration, shear rate, and protein content.
AB - Calcium-induced flocculation of caseinate-stabilized soybean oil-in-water
emulsions in conditions of Couette flow was studied. A concentrated emulsion (20%
oil, 0.5-2.0% sodium caseinate in 20 mM imidazole, pH 7) was diluted 20 times in
buffer containing concentrations of CaCl(2) between 9 and 17 mM and sheared at
rates between 335 and 1340 s(-)(1). The average particle size (d(43)), measured
by integrated light scattering, increased in a sigmoidal manner with shearing
time. An increased shear rate resulted in an increased flocculation rate, because
of the increased number of collisions between particles, but a decreased value of
the maximum d(43), because higher shear rates increasingly disrupted the flocs.
The flocculation rate was increased by increasing the calcium concentration,
indicating an increased collision efficiency. The orthokinetic stability of the
emulsions was increased with increased protein content, and it is postulated that
the increased surface coverage and hydrodynamic thickness of the adsorbed protein
layer increased steric repulsion between droplets, so that higher calcium
concentrations were necessary to induce sufficient conformational change of the
proteins to allow flocculation. At high caseinate concentrations, calcium may
also induce precipitation of unadsorbed caseins from the serum to the oil-water
interface, thereby increasing steric repulsion and hence increasing orthokinetic
stability.
PMID- 10691617
TI - Protein binding in deactivation of ferrylmyoglobin by chlorogenate and ascorbate.
AB - Kinetics of reduction of iron(IV) in ferrylmyoglobin by chlorogenate in neutral
or moderately acidic aqueous solutions (0.16 M NaCl) to yield metmyoglobin was
studied using stopped flow absorption spectroscopy. The reaction occurs by direct
bimolecular electron transfer with (2.7 +/- 0.3) x 10(3) M(-)(1).s(-)(1) at 25.0
degrees C (DeltaH( )(#) = 59 +/- 6 kJ.mol(-)(1), DeltaS(#) = 15 +/- 22 J. mol(
)(1).K(-)(1)) for protonated ferrylmyoglobin (pK(a) = 4.95) and with 216 +/- 50
M(-)(1).s(-)(1) (DeltaH( )(#) = 73 +/- 8 kJ. mol(-)(1), DeltaS( )(#) = 41 +/- 30
J.mol(-)(1).K(-)(1)) for nonprotonated ferrylmyoglobin in parallel with reduction
of a chlorogenate/ferrylmyoglobin complex by a second chlorogenate molecule with
(8.6 +/- 1.1) x 10(2) M(-)(1).s(-)(1) (DeltaH( )(#) = 74 +/- 8 kJ.mol(-)(1),
DeltaS( )(#) = 59 +/- 28 J.mol(-)(1).K(-)(1)) for protonated ferrylmyoglobin and
with 61 +/- 9 M(-)(1).s(-)(1) (DeltaH( )(#) = 82 +/- 12 kJ.mol(-)(1), DeltaS(
)(#) = 63 +/- 41 J. mol(-)(1).K(-)(1)) for nonprotonated ferrylmyoglobin.
Previously published data on ascorbate reduction of ferrylmyoglobin are
reevaluated according to a similar mechanism. For both protonated and
nonprotonated ferrylmyoglobin the binding constant of chlorogenate is
approximately 300 M(-)(1), and the modulation of ferrylmyoglobin as an oxidant by
chlorogenate (or ascorbate) leads to a novel antioxidant interaction for
reduction of ferrylmyoglobin by ascorbate in mixtures with chlorogenate.
PMID- 10691618
TI - Iron-accelerated cumene hydroperoxide decomposition in hexadecane and trilaurin
emulsions.
AB - Free radicals arising from lipid peroxides accelerate the oxidative deterioration
of foods. To elucidate how lipid peroxides impact oxidative reactions in food
emulsions, the stability of cumene hydroperoxide was studied in hexadecane or
trilaurin emulsions stabilized by anionic (sodium dodecyl sulfate; SDS), nonionic
(Tween 20), and cationic (dodecyltrimethylammonium bromide; DTAB) surfactants.
Fe(2+) rapidly (within 10 min) decomposed between 10 and 31% of the cumene
hydroperoxide in Tween 20- and DTAB-stabilized emulsions at pH 3.0 and 7.0 and in
the SDS-stabilized emulsion at pH 7.0 with no further decomposition of peroxides
occurring for up to 3 h. In SDS-stabilized emulsions at pH 3.0, Fe(2+) decreased
peroxides by 90% after 3 h. Decomposition of peroxides in the absence of added
iron and by Fe(3+) was observed only in SDS-stabilized emulsions at pH 3.0. These
results suggest that peroxide decomposition by iron redox cycling occurs when
iron emulsion droplet interactions are high.
PMID- 10691619
TI - Relationship among antioxidant activity, vasodilation capacity, and phenolic
content of red wines.
AB - The relationship among antioxidant activity, based on the electron-spin resonance
determination of the reduction of Fremy's radical, vasodilation activity, and
phenolic content was investigated in 16 red wines. The wines were selected to
provide a range of origins, grape varieties, and vinification methods. Sensitive
and selective HPLC methods were used for the analysis of the major phenolics in
red wine: free and conjugated myricetin, quercetin, kaempferol, and isorhamnetin;
(+)-catechin, (-)-epicatechin, gallic acid, p-coumaric acid, caffeic acid,
caftaric acid, trans-resveratrol, cis-resveratrol, and trans-resveratrol
glucoside. Total anthocyanins were measured using a colorimetric assay. The total
phenolic content of the wines was determined according to the Folin-Ciocalteu
colorimetric assay and also by the cumulative measurements obtained by HPLC. The
16 wines exhibited a wide range in the values of all parameters investigated.
However, the total phenol contents, measured both by HPLC and colorimetrically,
correlated very strongly with the antioxidant activity and vasodilation activity.
In addition, the antioxidant activity was associated with gallic acid, total
resveratrol, and total catechin. In contrast, only the total anthocyanins were
correlated with vasodilation activity. The results demonstrate that the different
phenolic profiles of wines can produce varying antioxidant and vasodilatant
activities, which opens up the possibility that some red wines may provide
enhanced health benefits for the consumer.
PMID- 10691620
TI - Unsaponifiable lipid constituents of some underutilized tropical seed oils.
AB - Sterols, triterpene alcohols, and hydrocarbons present in the unsaponifiable
fraction of some underutilized tropical seed oils have been examined. The seeds
include Telfairia occidentalis (TLO), Andenopus breviflorus (ADB), Cucumeropsis
edulis (CME), Antiaris africana (ATF), and Monodora tenuifolia (MNT). The oil
content of the seeds was high (34.7-68.8%), whereas triacylglycerols comprised
the dominant lipid group in the oils (65.4-73.9%). The percentage of
unsaponifiables ranged from 1.1 to 7.9%. Ten sterols were identified in the
fractions. In the Cucurbitaceae oils (TLO, CME, and ADB), Delta(7)-sterols
constituted the dominant sterols. These include 24-ethylcholesta-7,22E,25-trienol
(7), 24-ethylcholesta-7,25-dienol (9), 24Z-ethylidenecholes-7-enol (10), and 24
ethylcholesta-7, 24-dienol (11). However Delta(5)-sterols (1-5) occurred at the
highest concentration in the other two samples (ATF and MNT). Fifteeen triterpene
alcohols were detected in the fractions. Olean-12-enol (16), isomultiflorenol
(8), and lupeol (23) were the dominant alcohols in the Cucurbitaceae family,
whereas alpha-amyrin (urs-12-enol) (20) was the dominant triterpene alcohol in
ATF and MNT. A mixture of C(18)-C(34) n-alkanes, squalene, and some monoterpenes
was detected in the hydrocarbon fraction.
PMID- 10691621
TI - Isolation and structural elucidation of two new glycosides from sage (Salvia
officinalis L.).
AB - Six compounds, 1-O-(2,3, 4-trihydroxy-3-methyl)butyl-6-O-feruloyl-beta-D
glucopyranoside, ethyl beta-D-glucopyranosyl tuberonate, p-hydroxybenzoic acid, (
)-hydroxyjasmonic acid, caffeic acid, and 4-hydroxyacetophenone 4-O-[5-O-(3, 5
dimethoxy-4-hydroxybenzoyl)-beta-D-apiofrunosyl]-(1-->2)-beta-D- glu
copyranoside, were isolated from the n-butanol-soluble fraction of sage leaf
extracts. Their structures were determined by spectral methods (MS, NMR, and 2D
NMR), and their antioxidant activities were measured. Among them, two new
glycosides were elucidated. All of these compounds showed DPPH free radical
scavenging activity at the concentration of 30 mM, and caffeic acid was the most
active compound.
PMID- 10691622
TI - Use of two-dimensional electrophoresis to evaluate proteolysis in salmon (Salmo
salar) muscle as affected by a lactic fermentation.
AB - Two-dimensional electrophoresis was used to study proteolysis in salmon fillets
inoculated or not with the starter culture Lactobacillus sake LAD. Protein
fragments appeared increasingly with time in both samples, indicating that the
main quantitative changes were due to endogenous enzymes. In the most acidic zone
(pI = 4-6. 20) particularly, proteolysis was overall independent from processing.
In contrast, fermentation had a significant effect in the pH range 6.20-8.35,
suggesting a specificity of the bacterial proteases of L. sake toward alkaline to
slightly acidic proteins. Furthermore, fragments surrounding tropomyosin
(apparent pI = 4.70) appeared in fermented samples, indicating that the protein
may be a suitable substrate for the metabolism of L. sake LAD.
PMID- 10691623
TI - Distribution and characterization of enzymes causing starch degradation in rice
(Oryza sativa cv. koshihikari).
AB - The thermal dependency and stability of enzymes producing reducing sugar (RS)
were examined in bran, the exterior 13% part (outer endosperm), and the remaining
inner endosperm of rice grains. RS-producing enzymes in the inner endosperm
showed a higher optimum temperature than those in other parts of the rice grain.
Diethylaminoethyl-Sephacel chromatography of crude extracts revealed two peaks of
RS-producing activity with different optimum temperatures (60 and 37 degrees C)
in all three parts. alpha-Glucosidase (EC 3.2.1.20) and alpha-amylase (EC
3.2.1.1) isoform G were thought to be major components of the RS-producing
activities with high and low optimum temperatures, respectively. The peak with a
high optimum temperature was a more abundant component in the inner endosperm,
compared with other parts of the rice grain. Thus, different parts of rice were
found to have distinct enzyme sets having different thermal dependency and to be
involved in starch degradation to various sugars.
PMID- 10691624
TI - Isolation and identification of stilbenes in two varieties of Polygonum
cuspidatum.
AB - The roots of two varieties of Polygonum cuspidatum (Hu Zhang and Mexican Bamboo)
were analyzed for resveratrol and analogues. The roots of each variety were dried
and ground into a powder. The powdered roots were then extracted with methanol
and ethyl acetate. The ethyl acetate fraction of the Mexican Bamboo was then
subjected to fractionation and purification using silica gel column
chromatography and semipreparative HPLC. In addition to resveratrol (3,5,4'
trihydroxystilbene), three stilbene glucosides were identified by (1)H NMR, (13)C
NMR, and MS. The stilbene glucosides were shown to be a piceatannol glucoside
(3,5,3', 4'-tetrahydroxystilbene 4'-O-beta-D-glucopyranoside), resveratroloside
(3,5,4'-trihydroxystilbene 4'-O-beta-D-glucopyranoside), and piceid (3,5,4'
trihydroxystilbene 3-O-beta-D-glucopyranoside). The levels of the piceatannol
glucoside and piceid were twice as high in the Mexican Bamboo as compared to the
Hu Zhang.
PMID- 10691625
TI - Purification and partial characterization of a second cysteine proteinase
inhibitor from ungerminated barley (Hordeum vulgare L.).
AB - It was previously shown that ungerminated barley contains inhibitors that
suppress the activities of green malt cysteine proteinases. This paper reports
the purification and partial characterization of a second barley cysteine
endoproteinase inhibitor, a protein called lipid transfer protein 2 (LTP2). The
chromatographically purified inhibitor had a molecular mass of 7112. The amino
acid composition and sequence data of the purified inhibitor indicated that it
was a protein whose gene, but not the protein itself, was isolated earlier from
barley aleurone tissue. The purified protein inhibited the activities of
electrophoretically separated green malt cysteine proteinases but not the
activities of the serine- or metalloproteinases. The purified LTP2 inhibited the
same proteases as the LTP1 that was characterized previously but was present in
the mature seed in much smaller amounts. Neither LTP1 nor LTP2 has been proven to
transport lipids in vivo, and it seems possible that both serve to keep cysteine
endoproteinases that are synthesized during barley seed development inactive
until the plant needs them. The small amount of LTP2 in the seed made it
impossible to determine whether it, like LTP1, is involved in beer foam
formation. Because of its proteinase-inhibiting ability and its resistance to
heat inactivation, some of the LTP2 may persist in beer.
PMID- 10691626
TI - Lipophilization of lysozyme by short and middle chain fatty acids.
AB - Hen egg white lysozyme was lipophilized with short and middle chain saturated
fatty acids (caproic, capric, or myristic acid). The yield, bactericidal
properties, and structural properties of lipophilized lysozymes were
investigated. The yield of lipophilization of lysozyme greatly increased with the
decrease in the chain length of fatty acid. Lipophilization broadened the
bactericidal action of lysozyme to Gram-negative bacteria with little loss of
enzymatic activity. The bactericidal activity increased in proportion to the
number of bound short chain fatty acids. The thermal stability of lipophilized
lysozyme decreased in proportion to the chain length and number of bound fatty
acids.
PMID- 10691627
TI - Isolation of homogeneous fractions from wheat water-soluble arabinoxylans.
Influence of the structure on their macromolecular characteristics.
AB - Water-soluble arabinoxylans from wheat flour were purified and fractionated by
graded ethanol precipitation. Six fractions were obtained at 20% (F20), 30%
(F30), 40% (F40), 50% (F50), 60% (F60), and 70% (F70) saturation with ethanol.
Neutral sugars and (1)H NMR analyses revealed differences in structural
characteristics. The Ara/Xyl ratio and the amount of Xylp residues disubstituted
increased with ethanol concentration. Ferulic acid content was higher in
fractions precipitated at low ethanol percentage. Fractions were refractionated
by SEC, leading to 46 subfractions with low polydispersity index. Substitution
degree was apparently linearly related to the amount of disubstituted Xylp.
Macromolecular characteristics (M(w), [eta], R(G), q, nu) determined by
multiangle laser light scattering and viscosimetry were similar among all
fractions. A rather flexible conformation was determined for the arabinoxylans,
in conflict with the admitted rodlike conformation. The substitution degree had
no influence on the conformation or on the rigidity of the polymers. Evidence for
the presence of ferulic acid dimers in the water-soluble arabinoxylans is
provided, which probably explains the unexpected conformation and macromolecular
characteristics.
PMID- 10691628
TI - Kinetics and mechanism of the primary steps of degradation of carotenoids by acid
in homogeneous solution.
AB - The kinetics of reaction between trifluoroacetic acid as an acid of medium
strength and the carotenoids beta-carotene, zeaxanthin, canthaxanthin, and
astaxanthin has been examined in detail including the effects of dioxygen, acid
concentration, and carotenoid structure. Reaction between acid and carotenoid
leads to species absorbing in the red and near-infrared (NIR) spectral regions,
intermediates that subsequently disappear. ESR experiments clearly show that
these species are not carotenoid radicals, although their NIR absorption is
similar to the absorption of carotenoid radical cations. Under most reaction
conditions, the disappearance of carotenoids follows pseudo-zero-order kinetics,
whereas the reaction order is >1 with respect to acid, and the long-lived (hours)
intermediates are suggested to be mono- (700 nm) and diprotonated carotenoid (
approximately 950 nm). Acid induces cis/trans-isomerization via the protonated
intermediates, which also decay to nonradical species with shorter conjugated
systems-most probably carotenoid esters. Slow protonization of the methine carbon
is the primary step in the degradation, but dioxygen increases the rate as a
result of formation of a charge-transfer complex with the carotenoids as
indicated by a red-shift of the NIR absorption bands. Carotenoids with carbonyl
groups (astaxanthin and canthaxanthin) have slower rates of degradation than beta
carotene and zeaxanthin, indicating preferential nondegradative protonation of
the carbonyl groups.
PMID- 10691629
TI - HPLC detection of soluble carbohydrates involved in mannitol and trehalose
metabolism in the edible mushroom Agaricus bisporus.
AB - A convenient and sensitive method was developed to separate and detect various
types of carbohydrates (polyols, mono- and disaccharides, and phosphorylated
sugars) simultaneously using high-performance liquid chromatography (HPLC). The
method consists of a chromatographic separation on a CarboPac PA1 anion-exchange
analytical column followed by pulsed amperometric detection. In a single run (43
min) 13 carbohydrates were readily resolved. Calibration plots were linear over
the ranges of 5-25 microM to 1. 0-1.5 mM. The reliable and fast analysis
technique, avoiding derivatization steps and long run times, was used to
determine the levels of carbohydrates involved in mannitol and trehalose
metabolism in the edible mushroom Agaricus bisporus. Moreover, the method was
used to study the trehalose phosphorylase reaction.
PMID- 10691630
TI - Effect of calcium on the oxidation of linoleic acid by potato (Solanum tuberosum
var. Desiree) tuber 5-lipoxygenase.
AB - When the effect of calcium on the oxidation of linoleic acid by potato tuber 5
lipoxygenase (LOX) was investigated, it was seen to promote the enzyme's activity
at pH values higher than the optimum pH of 6.3, resulting in an enzyme activation
at alkaline pH. Kinetic analysis of calcium activation at different pH values
revealed that the cation abolished the inhibition by high substrate
concentration, which occurs in the absence of Ca(2+), thus leading to activation
at high substrate concentration. Studies were conducted to investigate the
influence of Ca(2+) on the physicochemical nature of the substrate and its effect
on the LOX activity expression. It was concluded that the aggregation mode rather
than the aggregation state of linoleic acid is responsible for potato 5-LOX
changes.
PMID- 10691631
TI - Enzymatic assay for the determination of olive oil polyphenol content: assay
conditions and validation of the method.
AB - A new spectrophotometric assay for the determination of the polyphenolic content
of olive oil is presented. It is a substrate-recycling assay for phenolic
compounds that employs tyrosinase in the presence of excess NADH. The reaction of
various phenols with the enzyme produces an o-quinone, which is detected by
recycling between reactions with the enzyme and NADH. The method offers some
advantages over the classical methods employed to determine the polyphenolic
content of olive oil, that is, ease and reproducibility of the analysis, highly
increased sensitivity, and selectivity toward phenolic compounds. The amount of
total polyphenols was determined in virgin olive oils both with the Folin
Ciocalteu reagent and with the proposed enzymatic method. The results suggest a
better estimation of the polyphenol content, as compared with the colorimetric
method. This has to be attributed to the different reactivities of the two
methods toward phenols and catechols. Finally, the enzymatic method demonstrates
that there is a linear relationship between the olive oil phenolic content and
the antioxidative capacity of oil extracts.
PMID- 10691632
TI - Effect of electron microscopy fixation pH on the ultrastructure of soybean
protein bodies.
AB - Cotyledon tissues from mature soybeans were systematically prepared for
transmission electron microscopy employing fixation buffer pH's of 7.2, 6.4, and
5.6. Tissue fixed at pH 7.2 showed few membrane-bound internal protein body
structures. Portions of the same tissue fixed at pH 6.4 revealed numerous
membrane-bound crystalloid structures and stacks of membranous sacks. Tissue
prepared at pH 5.6 also contained numerous membrane-bound crystalloid structures
and examples of membrane-bound globoid structures. This is the first
investigation to document the effect of fixation pH on the subcellular structure
of soybean protein bodies and the first to show membrane-bound crystalloid or
globoid structures in soybeans.
PMID- 10691633
TI - Synthesis of haptens and conjugates for ELISAs of phytoestrogens. Development of
the immunological tests.
AB - Seven carboxylic acid haptens of isoflavonoids were synthesized, with the spacer
arm on the oxygen atom at the C7 position for one series, with formononetin,
daidzein, equol, biochanin A, and genistein, and at the C8 position for a second
series, with only formononetin and daidzein. The different haptens were coupled
to bovine serum albumin (BSA) and to swine thyroglobulin (Thyr). Polyclonal
antibodies were generated against the BSA conjugates. Enzyme-linked immunosorbent
assays (ELISAs) were developed based on competition between free phytoestrogens
and the Thyr-hapten conjugates for specific antibodies. IC(50) values of the
standard curves ranged between 0.8 and 20 ng/mL that is, 0.3 and 9.2 pmol/well.
The antibodies obtained should be useful for assays in vegetable matter as well
as in biological fluids after a separation step. These ELISAs should be valuable
also in the food industry to control phytoestrogen concentrations prior to and
after processing.
PMID- 10691634
TI - Simultaneous stopped-flow determination of butylated hydroxyanisole and propyl
gallate using a T-format luminescence spectrometer.
AB - A simple and fast luminescent method is used for the first time to resolve a
mixture of two synthetic antioxidants, propyl gallate (PG) and butylated
hydroxyanisole (BHA), by the joint use of the stopped-flow mixing technique and a
T-format luminescence spectrometer. The determination of these compounds involves
two different and independent reactions. On the one hand, PG determination is
based on an energy transfer process that involves the formation of a lanthanide
chelate with terbium in the presence of Triton X-100 and tri-n-octylphosphine
oxide. On the other hand, BHA is determined using a reaction between the oxidized
form of Nile Blue and the antioxidant. Both systems are excited at the same
excitation wavelength (310 nm), and the emission wavelengths are 545 and 665 nm
for PG and BHA, respectively. The absence of overlap in the emission spectra
makes it possible to measure separately the analytes in each channel of the
instrument. Initial rate and equilibrium signal are used as analytical parameters
and measured in 0.1 and 1 s for PG and BHA, respectively. Calibration graphs are
linear over the range 0.09-3.5 microg mL(-)(1) for PG and 0.3-15 microg mL(-)(1)
for BHA. The relative standard deviations of both systems are close to 2%. The
proposed method is applied to the determination of these two antioxidants in
several commercial food samples with recoveries ranging between 94.8 and 102.9%
for PG and between 94.1 and 102.1% for BHA.
PMID- 10691635
TI - Acetonitrile as a buffer additive for free zone capillary electrophoresis
separation and characterization of maize (Zeamays L. ) and sorghum (Sorghum
bicolor L. Moench) storage proteins.
AB - An improved method for separating and characterizing maize (Zea mays L.) and
sorghum (Sorghum bicolor L. Moench) storage proteins by free zone capillary
electrophoresis (FZCE) was developed. Previous electrophoretic methods for
analyzing these proteins required high concentrations of urea to maintain protein
solubility during separation. To overcome disadvantages of urea, we developed a
FZCE method that mimicked reversed-phase high-performance liquid chromatography
(RP-HPLC) in that it used high levels of acetonitrile (ACN) at low pH. The
optimized FZCE buffer system consisted of 80 mM phosphate-glycine buffer, nominal
pH 2.5, containing 60% ACN and a cellulose derivative to dynamically coat
capillary walls. Resolution was similar to or higher than that previously
achieved by FZCE buffers utilizing 8 M urea as a buffer additive. ACN
concentrations of at least 50% were necessary to achieve acceptable separations;
this ACN concentration is approximately that necessary to extract these storage
proteins. ACN was equally effective as traditional ethanol solvents and 8 M urea
for solubilizing maize and sorghum proteins. The ACN-based FZCE buffer system
gave high repeatability (<0.3% relative standard deviation, measured over 15
consecutive injections) for migration time. Subclasses of maize and sorghum
storage proteins were identified, and genotypes of each cereal were successfully
differentiated using ACN-containing buffers. This FZCE method may be applicable
for the analysis of other hydrophobic proteins without the use of urea.
PMID- 10691636
TI - Comparison of protein surface hydrophobicity measured at various pH values using
three different fluorescent probes.
AB - The influence of type of fluorescent probe on the surface hydrophobicity values
determined for three native and heated proteins was assessed using uncharged [6
propionyl-2-(N, N-dimethylamino)naphthalene or PRODAN] versus anionic aliphatic
(cis-parinaric acid or CPA) and aromatic (1-anilinonaphthalene-8-sulfonic acid or
ANS) probes. Surface hydrophobicities of whey protein isolate, beta
lactoglobulin, and bovine serum albumin under heated (80 degrees C for 30 min)
and unheated conditions and at varying pH values (3.0, 5.0, 7.0, and 9. 0) were
measured using ANS, CPA, and PRODAN. ANS and CPA yielded opposing results for the
effects of pH and heating on protein hydrophobicity. Hydrophobicity was lower at
pH 3.0 than at other pH values for all proteins measured by PRODAN, whereas the
values measured by ANS and CPA at pH 3.0 were quite high compared to those at
other pH values, suggesting the influence of electrostatic interactions on
anionic probe-protein binding. These results suggest that the presence or absence
of a permanent charge as well as the aromatic and aliphatic nature of fluorescent
probes can affect protein hydrophobicity values measured under various pH
conditions.
PMID- 10691637
TI - Functional scFv antibody sequences against the organophosphorus pesticide
chlorpyrifos.
AB - Two functional single-chain Fv (scFv) antibodies that recognize specifically the
widely used organophosphorus pesticide chlorpyrifos-ethyl were derived from two
murine hybridoma cell lines. It is shown that the functional scFvs could be
isolated without any rounds of selection, with a success rate dependent on the
efficiency of amplification of the functional light chain gene family by the
specific primers. Besides four new functional immunoglobulin variable gene
sequences, the isolation of a new pseudogene is reported.
PMID- 10691638
TI - Separation and purification of anthocyanins by high-speed countercurrent
chromatography and screening for antioxidant activity.
AB - The all-liquid chromatographic technique of high-speed countercurrent
chromatography (HSCCC) has been applied for separations of anthocyanins. The
biphasic mixture of tert-butyl methyl ether/n-butanol/acetonitrile/water
(2:2:1:5) acidified with trifluoroacetic acid was found to be a suitable solvent
system for anthocyanin separation. In some cases, enrichment of the pigments on
Amberlite XAD-7 resin prior to HSCCC has been carried out. The anthocyanin
mixtures from red cabbage, black currant, black chokeberry, and roselle were
successfully fractionated using HSCCC. Peak purity control was done by nuclear
magnetic resonance spectroscopy as well as electrospray ionization ion trap
multiple mass spectrometry. Finally, antioxidant activity of the purified
pigments was determined using the Trolox equivalent antioxidant capacity test.
PMID- 10691639
TI - Ultrafast capillary electrophoretic analysis of cereal storage proteins and its
applications to protein characterization and cultivar differentiation.
AB - Free zone capillary electrophoresis conditions have been improved to allow rapid
(2-8 min) separations of grain proteins from several cereals (wheat, oats, rice,
barley, and rye) with high resolution and reproducibility. This new method
utilized the isoelectric compound iminodiacetic acid (IDA) in conjunction with
20% acetonitrile and 0.05% hydroxypropylmethylcellulose. Cultivars of all cereals
tested could be differentiated in 3 min, including wheat, using either prolamin
or glutelin protein patterns. Resolution was similar to or higher than that of
separations in other acidic buffers. Migration time repeatability was excellent
with run-to-run variability <1% RSD, day-to-day <1.4% RSD, and capillary-to
capillary <3.3% RSD. Because larger inner diameter capillaries (50 microm) could
be used with this buffer, sensitivity was improved and capillary rinse times
could be reduced when compared to smaller capillaries (25 microm i.d.). This also
served to reduce total separation time so that the majority of cereal storage
protein from several types of cereals could be analyzed with total analysis times
of 2-8 min with extremely high resolution and repeatability. This method would
allow unattended, high-throughput ( approximately 180-400 samples/24 h) analysis
of cereal proteins without the generation of much organic solvent waste as well
as automated data analysis and storage.
PMID- 10691640
TI - LC-ESI-MS study of the flavonoid glycoside malonates of red clover (Trifolium
pratense).
AB - High-performance liquid chromatography-electrospray ionization-mass spectrometry
(LC-ESI-MS) was applied to the analysis of the flavonoids and their glycoside
malonates of the flowers and leaves of red clover (Trifolium pratense). Through
LC-MS comparative studies on the plant extracts and their malonate-free extracts,
approximately 20 flavonoid glycoside malonates were detected in the flower
extract. Eight were identified as genistin 6' '-O-malonate (39), formononetin 7-O
beta-D-glucoside 6' '-O-malonate (40), biochanin A 7-O-beta-D-glucoside 6' '-O
malonate (41), trifoside 6' '-O-malonate (42), irilone 4'-O-beta-D-glucoside 6' '
O-malonate (43), pratensein 7-O-beta-D-glucoside 6' '-O-malonate (44),
isoquercitrin 6' '-O-malonate (45), and 3-methylquercetin 7-O-beta-D-glucoside 6'
'-O-malonate (46). About 15 other flavonoids and clovamides were proved to be
present in this extract. The study also found that the flowers contained flavones
as the major flavonoids, whereas the leaves had isoflavones as the major
flavonoids. This is the first detection of the six malonates (39 and 42-46) in
the extracts of red clover, and among them, 42, 43, and 46 are new compounds.
PMID- 10691641
TI - Determination of spinosad and its metabolites in citrus crops and orange
processed commodities by HPLC with UV detection.
AB - Spinosad is an insect control agent that is derived from a naturally occurring
organism and is effective on a wide variety of crops, including citrus crops. A
method is described for the determination of spinosad and its metabolites in
citrus crops and orange processed commodities. The method determines residues of
the active ingredients (spinosyns A and D) and three minor metabolites (spinosyn
B, spinosyn K, and N-demethylspinosyn D). For dried orange pulp and orange oil,
the method has a limit of quantitation (LOQ) of 0.02 microg/g and a limit of
detection (LOD) of 0.006 microg/g. For all other sample matrices (whole fruit,
edible fruit, juice, and peel), the method has an LOQ of 0.01 microg/g and an LOD
of 0.003 microg/g. The analytes are extracted from the various sample types using
appropriate solvents, and the extracts are purified by liquid-liquid partitioning
and/or solid-phase extraction. All five analytes are determined simultaneously in
the purified extracts by reversed-phase high-performance liquid chromatography
with ultraviolet detection at 250 nm.
PMID- 10691642
TI - Isolation of novel glucosides related to gingerdiol from ginger and their
antioxidative activities.
AB - Two novel glucosides of 6-gingerdiol were isolated from fresh ginger (Zingiber
officinale Roscoe). Their structures were determined as 1-(4-O-beta-D
glucopyranosyl-3-methoxyphenyl)-3,5-dihydroxydecane (1) and 5-O-beta-D
glucopyranosyl-3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)deca ne (2) by HRFAB-MS and
NMR analyses, and the absolute configurations of both aglycons were identified as
(3S,5S) by a comparison with synthetic compounds. After incubating these
glucosides with acetone powder prepared from fresh ginger, they were confirmed to
have been hydrolyzed to 6-gingerdiol by HPLC. This result suggests that these
glucosides are the precursors or intermediates of 6-gingerdiol. To recognize
their function, their antioxidative activities were investigated and compared to
that of their aglycon, 6-gingerdiol, by a linoleic acid model system and by their
DPPH radical-scavenging ability. Although 1 did not indicate any activity, 2 had
as strong activity as the aglycon in both measurements.
PMID- 10691643
TI - First report of the characterization of the threatened plant species Amaranthus
pumilus (Seabeach amaranth).
AB - This paper reports the first ever investigation of the chemical
components/composition of the seeds of Amaranthus pumilus (a threatened amaranth
species) and compares the results to those of the more commonly cultivated
Amaranthus hypochondriacus (Plainsman). This study clearly revealed that much
genetic diversity exists between these species, indicating that potential
breeding possibilities for the improvement of more commonly cultivated amaranth
lines do exist. A. pumilus offers a much larger and more desirable seed size and
weight (2-3-fold higher), permitting greater biomass production, in addition to
lower levels (half) of free carbohydrate for improved value/performance in
diabetic-type diets. In addition to the higher edible oil content found in A.
pumilus, its lower saturated/unsaturated ratio (one of the lowest thus far
measured) makes it potentially a better source of nutritional oil. In addition to
the 2-fold-higher quantity of vitamin E found in A. pumilus, the higher levels of
squalene also found may one day serve as a renewable crop source of this compound
and may diminish the world's dependence upon marine animals. Considering the
imminent danger posed to the survival of the seabeach amaranth in its native
environment, it is hoped this study will raise public awareness of the importance
of this species and thereby protect it from reaching extinction.
PMID- 10691644
TI - Composition of suberin extracted upon gradual alkaline methanolysis of Quercus
suber L. cork.
AB - The monomeric composition of suberin extracts obtained by gradual alkaline
methanolysis of Quercus suber cork was determined by gas chromatography-mass
spectrometry (GC-MS). Results show that 1-alkanols and alkanoic and alpha,omega
alkanedioic acids are preferentially removed upon mild alkaline conditions,
whereas mid-chain-modified omega-hydroxyalkanoic acids are preferentially removed
under stronger alkaline conditions. Saturated omega-hydroxyalkanoic acids are
found to be abundant in all suberin extracts. These results are consistent with
two distinct suberin fractions with different locations in cork cell walls and/or
esterification degrees. It is proposed that these fractions correlate with the
two main suberin peaks in the solid state (13)C NMR spectra of cork and suberin
extracts. Quantitative GC-MS analysis showed that suberin monomers comprise
approximately 30% (w/w) of the suberin extracts, the remaining comprising
nonvolatile structures with high M(n) values, as measured by vapor pressure
osmometry. The presence of a large fraction of high molecular weight aliphatic
structures in suberin extracts is supported by the corresponding NMR spectra.
PMID- 10691645
TI - N-Nitrosation of myosmine yields HPB (4-hydroxy-1-(3-pyridyl)-1-butanone) and NNN
(N-nitrosonornicotine).
AB - N-Nitrosonornicotine (NNN) is formed by synthetic or biological N-nitrosation of
the tobacco alkaloid nornicotine. Following metabolic activation of NNN, DNA and
protein adducts are formed releasing 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB), an
actual biomarker to differentiate between tobacco smokers and passive smokers.
NNN and HPB can be prepared in a new one-step reaction by N-nitrosation of the
nicotinoid myosmine which has been found not only in tobacco but also in nut
products. The reaction was tested also in human gastric juice. The formation rate
of NNN and HPB depends on the pH value in the reaction solutions. This is
important under the aspect of myosmine uptake by humans from other biological
sources and subsequent biological activation. The new reaction pathway indicates
that human exposure to nicotinoid nitrosation products seems to be not restricted
exclusively to tobacco.
PMID- 10691646
TI - Phase behavior and component partitioning in low water content amorphous
carbohydrates and their potential impact on encapsulation of flavors.
AB - The compositions at which amorphous ethanol-maltose-water mixtures exhibit liquid
liquid separation have been determined in the temperature range from 20 to 80
degrees C. At water contents below approximately 20% w/w two phases were
observed, with the maltose-rich phase slightly richer in water. Partition
coefficients of organic nonelectrolytes ranging in hydrophobicity from 1, 2
ethanediol and 1,2-propanediol to benzyl alcohol and propyl acetate have been
measured for octanol/sorbitol, benzyl alcohol/sorbitol, and 1-butanol/sorbitol
mixtures. Linear correlations were found between the log partition coefficients
in the various solvent systems. Replacing water with sorbitol results in more
organic partitioning into the octanol. Replacing octanol with benzyl alcohol or 1
butanol also results in more organic partitioning into the hydrophobic phase. The
results establish a relationship with partition coefficients for octanol/water
mixtures, which are well studied experimentally and for which predictive
approaches exist. The implications of these results for flavor retention and
encapsulation are discussed.
PMID- 10691647
TI - Identification of impact odorants in Bordeaux red grape juice, in the commercial
yeast used for its fermentation, and in the produced wine.
AB - The aroma extract dilution analysis method was used to detect the impact odorants
of Bordeaux Cabernet Sauvignon and Merlot wines extracts, as well as those of the
extracts of the corresponding Cabernet Sauvignon juice and dry yeasts used for
its fermentation. The wines and the yeasts were extracted using dichloromethane,
and the juice was extracted using Amberlite XAD-2. Structural identification of
the impact odorants using gas chromatography-mass spectrometry and atomic
emission detection (sulfur acquisition) was achieved after enrichment of these
extracts by silica gel and Affi-Gel 501 chromatography. The same odorants (with
the exception of dimethyl sulfide among 48) were detected in both wine extracts,
with about the same flavor dilution (FD) factors. The 18 impact odorants detected
in the Cabernet Sauvignon juice and dry yeast extracts were also found in the
wine extracts. The odorants with the highest FD factors were 3
(methylsulfanyl)propanal, (E,Z)-nona-2, 6-dienal, and decanal in the juice
extract, 2-methyl-3-sulfanylfuran, 3-(methylsulfanyl)propanal, 2-/3
methylbutanoic acids, and phenylethanal in the dry yeast extract, and 2-/3
methylbutanols, 2-phenylethanol, 2-methyl-3-sulfanylfuran, acetic acid, 3
(methylsulfanyl)propanal, 2-/3-methylbutanoic acids, beta-damascenone, 3
sulfanylhexan-1-ol, Furaneol, and homofuraneol in the wine extracts.
Determination of the odor thresholds of some of these impact odorants was carried
out.
PMID- 10691649
TI - Volatile compounds from Escherichia coli O157:H7 and their absorption by
strawberry fruit.
AB - Volatile compounds emitted by cultures of two strains of the pathogenic bacterium
Escherichia coliO157:H7 and a nonpathogenic strain of E. coli were trapped on
Super-Q porous polymer and identified by GC-MS. The predominant compound produced
by all three strains was indole with lesser amounts of other components including
methyl ketones, 2-heptanone, 2-nonanone, 2-undecanone, and 2-tridecanone. The
vapor-phase profiles of these strains were similar for most chemicals identified
but differed with regard to ketones. Strawberry fruit was shown to be a suitable
host for E. coli O157:H7 with the population of the bacterium either increasing
or remaining stable after 3 days depending on inoculation level. Headspace
analysis of the volatile compounds from inoculated fruit yielded no detectable
quantity of indole. Strawberry fruit readily absorbed indole and other volatile
compounds produced by the bacteria and in some cases metabolized the compounds to
new volatile products. Thus, headspace "marker" compounds indicating possible
bacterial contamination of fruit were largely removed from the vapor phase by the
strawberries.
PMID- 10691648
TI - Study of interactions between food phenolics and aromatic flavors using one- and
two-dimensional (1)H NMR spectroscopy.
AB - Changes in flavor release and aroma characteristics in a medium including food
phenolics may be attributed to an intermolecular interaction between flavor
compounds and phenolics. To investigate the interaction, one- and two-dimensional
NMR studies have been carried out on the binding of two phenolics, gallic acid
and naringin, with three aroma compounds, 2-methylpyrazine, vanillin, and ethyl
benzoate. Evaluation of thermodynamic parameters and intermolecular nuclear
Overhauser effects reveals that gallic acid can interact more strongly with
aromatic flavors than naringin. The supramolecular complexation is also dependent
on the structural nature of the flavors, with 2-methylpyrazine and vanillin
interacting more strongly than ethyl benzoate. The interaction is principally pi
pi stacking between the galloyl ring and the aromatic ring of the aroma
compounds, but secondary hydrogen-bonding effects help to stabilize the complex
and enhance the specificity.
PMID- 10691650
TI - 3-Mercapto-2-methylpentan-1-ol, a new powerful aroma compound.
AB - 3-Mercapto-2-methylpentan-1-ol was first detected in a complex thermally
processed flavor and finally isolated from raw onions. The chemical structure of
this new compound was identified by MS and (1)H NMR measurement and synthesis of
the proposed structure. Sensory evaluation at different concentrations indicated
that the flavor quality is strongly dependent on concentration. At low
concentration (0.5 ppb) a pleasant meat broth, sweaty, onion, and leek-like odor
can be perceived. On the basis of some isolation experiments and volatiles
occurring in raw onions, a formation pathway is proposed. As one intermediate 3
mercapto-2-methylpentanal, another new strong flavor compound, was suggested. The
presence of this compound in raw onions was confirmed by synthesis and comparison
of MS and chromatographic data.
PMID- 10691651
TI - Enantioselective syntheses and sensory properties of the 3-mercapto-2
methylpentanols.
AB - 3-Mercapto-2-methylpentanol, a new powerful flavor compound, exhibits two
stereocenters giving rise to two pairs of diastereomers. To determine differences
in the sensory properties, all four diastereomers and enantiomers were stereo-
and enantioselectively synthesized. A highly diastereoselective aldol reaction
using a chiral auxiliary was one of the key steps in the synthesis. Further
derivatization yielded the enantiopure compounds. Odor thresholds in air and
water were determined.
PMID- 10691652
TI - Distribution of S-Alk(en)ylcysteine sulfoxides in some Allium species.
Identification Of a new flavor precursor: S-ethylcysteine sulfoxide (Ethiin).
AB - The content of S-alk(en)ylcysteine sulfoxides, important nonvolatile flavor
precursors, was determined in 15 different Allium species by means of gas
chromatography. The method employed is based on derivatization of S
alk(en)ylcysteine sulfoxides with ethyl chloroformate followed by their reduction
with sodium iodide. The total content of S-alk(en)ylcysteine sulfoxides varied
considerably in the wide range between 0.02 and 1.3% fresh weight. Not only the
total content but also relative proportions of individual derivatives varied to a
great extent. A novel S-alkylcysteine derivative, S-ethylcysteine sulfoxide
(ethiin), not previously reported to occur in Allium species, was found in most
of the samples examined in trace amounts. None of the other S-alk(en)ylcysteine
sulfoxides, for example, isopropyl, (Z)-1-propenyl, butyl, or pentyl, were
detected in any of the samples analyzed, limiting possible levels of each of
these components to =1 ppm in fresh weight.
PMID- 10691653
TI - Quantitative model studies on the formation of aroma-active aldehydes and acids
by strecker-type reactions.
AB - Application of aroma extract dilution analysis on the volatiles formed by
reacting glucose and L-phenylalanine (30 min, 100 degrees C) revealed the
Strecker aldehyde, phenylacetaldehyde (PA), and, in addition, phenylacetic acid
(PAA) as the two key odorants among the volatiles formed. Quantitative
measurements on alpha-dicarbonyl formation revealed that the 3-deoxyosone and
glyoxal were formed as the first prominent sugar degradation products, whereas 2
oxopropanal became predominant after approximately 4 h at 100 degrees C. Among
the four alpha-dicarbonyls analyzed, 2-oxopropanal proved to be the most
effective in generating PA as well as PAA from phenylalanine, but the reaction
parameters significantly influenced the ratio of both odorants; for example, at
pH 3.0 the ratio of PA to PAA was 3:1, whereas at pH 9.0 the ratio was 1:5.
Furthermore, in the presence of oxygen and copper ions the formation of the acid
was further increased. 3-Deoxyosone and glucosone were found to be effective
precursors of phenylacetaldehyde, but neither was very effective in acid
generation. On the basis of the results, a new oxygen-dependent formation pathway
of the Strecker reaction is proposed.
PMID- 10691654
TI - Sensory investigation of yogurt flavor perception: mutual influence of volatiles
and acidity.
AB - The sensory properties of traditional acidic and mild, less acidic yogurts were
characterized by a trained panel using a descriptive approach. Many of the
descriptive attributes varied almost linearly with pH, showing either a positive
or negative correlation with increasing acidity. The panel was very sensitive to
acidity differences, as demonstrated by the linear relationship between acidity
perception and pH. Important flavor differences were found between the two
classes of yogurt. They were mainly due to differences in acidity and not to
different concentrations of the three impact aroma compounds, acetaldehyde, 2,3
butanedione, and 2, 3-pentanedione. This emphasizes the importance of acidity in
yogurt flavor. Deodorization and impact aroma compound addition had much less
influence on yogurt flavor than pH variations.
PMID- 10691655
TI - Chemical and microbiological characteristics of ewes' milk cheese manufactured
with extracts from flowers of Cynara cardunculus and Cynara humilis as
coagulants.
AB - The chemical and microbial characteristics as well as the flavor and aroma of Los
Pedroches cheese made using aqueous extracts of Cynara cardunculus L. flowers
were compared with those of cheeses manufactured with extracts of Cynara humilis
L. throughout ripening. The two thistle species assayed were found to have no
appreciable effect on the moisture, fat, protein, and NaCl contents of the cheese
or on its water activity, flavor, and aroma; however, the use of C. humilis
resulted in reduced lactic acid content (p < 0.001) and higher pH values (p <
0.05) relative to those of cheese specimens produced with C. cardunculus. The
protein breakdown of the cheeses was assessed in terms of soluble nitrogen (SN),
nonprotein nitrogen (NPN), and amino acid nitrogen (AAN). Proteolysis was more
marked and rapid in cheese containing C. cardunculus as coagulant, the SN and NPN
contents of which were significantly higher (p < 0. 01) than those of the cheese
obtained with the species C. humilis; AAN contents were similar in both species
of Cynara throughout ripening. Although total viable, coliform, and lactobacilli
counts were similar in cheeses produced with both types of plant coagulant
throughout ripening, enterobacteria and yeasts counts (p < 0.01) and molds counts
(p < 0.05) were higher in cheese produced with C. humilis than in cheese obtained
with C. cardunculus.
PMID- 10691656
TI - Purification and characterization of a mannan-binding lectin specifically
expressed in corms of saffron plant (Crocus sativus L.).
AB - Despite the economical interest of Crocus sativus, its biochemistry has been
poorly studied. Herein, we have isolated a lectin present in saffron corm by gel
filtration, anion-exchange, and reversed-phase chromatography. One- and two
dimensional PAGE, MALDI-MS, and N-terminal amino acid sequence analyses indicated
that the native protein forms noncovalently linked aggregates of about 80 kDa
apparent molecular mass, mainly composed of two charged heterogeneous (pI's, 6.69
6.93) basic subunits of approximately 12 kDa. Their N-terminal sequences shared
25% similarity and were homologous to the N- and C-terminal domains of
monocotyledonous mannose-binding lectins, respectively. An additional polypeptide
of around 28 kDa apparent molecular mass was also detected, probably
corresponding to a precursor processed into two mature subunits. In addition, the
N-terminal domain subunit exhibited 56% similarity with curculin, a sweet protein
with taste-modifying activity. The native lectin specifically interacts with a
yeast mannan and is a major corm protein specifically expressed in this organ.
PMID- 10691657
TI - Effects of microwave heat, packaging, and storage temperature on fatty acid and
proximate compositions in rice bran.
AB - The effect of microwave heat, packaging methods, and storage temperatures on
proximate and fatty acid compositions of rice bran during 16 weeks of storage was
examined. Freshly milled raw rice bran was adjusted to 21% moisture content and
microwave heated for 3 min. Raw and microwave-heated brans were packed in zipper
top bags and/or vacuum-sealed bags and stored at 4-5 and/or 25 degrees C for 16
weeks. The moisture content decreased significantly from an initial 8.4 to 6.4%
in microwave-heated samples regardless of packaging methods and storage
temperatures. Protein, fat, linoleic, and linolenic contents did not change
significantly in all raw and microwave-heated samples during 16 weeks of storage.
The microwave-heated rice bran packed in zipper-top bags can be stored at 4-5
degrees C for up to 16 weeks without adverse effect on proximate and fatty acid
composition quality under the conditions employed in this study.
PMID- 10691658
TI - Presence of 2-furoylmethyl derivatives in hydrolysates of processed tomato
products.
AB - Acid hydrolysis of Amadori compounds yields the corresponding 2-furoylmethylamino
acids (2-FM-AA) that can be analyzed by ion-pair HPLC. The relative proportions
of the different 2-FM-AA present in the hydrolysates of tomato products were
determined to assess their usefulness as indicators of quality. In the
lyophilized tomato samples stored at 50 degrees C and a(w) = 0.44 the formation
of 2-FM derivatives of alanine, gamma-aminobutyric acid (GABA), asparagine,
aspartic acid, glutamic acid, lysine, serine, and threonine was detected. In
commercial tomato products the most abundant 2-FM-AA was 2-FM-GABA (from traces
to 26.4 mg/100 g of dry matter) followed by 2-FM-lysine (furosine). Differences
in 2-FM-AA contents among samples may be related to processing and storage
conditions.
PMID- 10691659
TI - Influence of high-intensity ultrasound and heat treatment in continuous flow on
fat, proteins, and native enzymes of milk.
AB - The effect of continuous flow high-intensity ultrasound (with and without heat
generation) on alkaline phosphatase, gamma-glutamyltranspeptidase,
lactoperoxidase, whey proteins (alpha-lactalbumin and beta-lactoglobulin),
casein, and fat was studied in milk. Results were compared with those obtained
using a conventional heating system having similar processing conditions. Hardly
any effect on enzymes was observed when ultrasound was applied without heat
generation. The highest denaturation of enzyme and whey proteins was found in
samples subjected to ultrasound and heat. At 61, 70, and 75.5 degrees C a
synergistic effect between ultrasound and heat was observed for the inactivation
of alkaline phosphatase, gamma-glutamyltranspeptidase, and lactoperoxidase,
respectively. A noticeable synergism between ultrasound and heat was detected for
alpha-lactalbumin and beta-lactoglobulin denaturation. No changes in the casein
were observed after any of the conditions assayed. As a consequence of ultrasound
effects, a substantial reduction (up to 81.5%) in the size of the fat globule was
observed. When 70 and 75.5 degrees C were achieved during high-intensity
ultrasonic homogenization, a better particle distribution was observed as
compared to that obtained at lower temperatures. This work describes the
influence of continuous flow high-intensity ultrasound on important milk
components as a first step for future processing applications.
PMID- 10691660
TI - Autoxidation in xylose/lysine model systems.
AB - The volatiles produced in xylose/lysine model systems added with an antioxidant
(alpha-tocopherol, 2,6-di-tert-butyl-4-methylphenol, or rosemary extract) or a
free radical initiator (alpha, alpha'-azobis(isobutyronitrile), AIBN) were
analyzed to investigate the effects of the presence of free radicals on the
Maillard reaction. The pH was maintained constant at 4 or 6, by adding a base,
and the data were compared by principal component analysis (PCA). The additives
were more effective at pH 4 than pH 6. At pH 4, the model system added with AIBN
is very well-discriminated by PCA from the models with the antioxidants and the
reference model system, indicating that the volatiles are sensitive to compounds
that can interfere in an opposite way with free radical formation.
PMID- 10691661
TI - Analysis of annatto (Bixa orellana) food coloring formulations. 2. Determination
of aromatic hydrocarbon thermal degradation products by gas chromatography.
AB - Twenty samples of commercial annatto formulations have been analyzed for m-xylene
and toluene using ambient alkaline hydrolysis, followed by solvent extraction and
capillary gas chromatography. Fifteen of the samples contained <5 mg/kg toluene,
four samples contained between 5 and 10 mg/kg toluene, and one sample contained
12 mg/kg toluene. The amounts found of m-xylene were 200 mg/kg (one sample), 160
mg/kg (one sample), between 30 and 88 mg/kg (four samples), between 7 and 25
mg/kg (seven samples), and <5 mg/kg (seven samples). Bixin-in-oil formulations
contained the highest m-xylene concentrations and also gave the largest increase
in headspace m-xylene concentration when heated in closed systems. The results
are evidence for the thermal degradation of annatto during source extraction and
processing, resulting in contamination by internal generation of both bixin and
norbixin types with aromatic hydrocarbons. Two samples of norbixin of known
production history (i. e., thermal versus nonthermal processes) were analyzed
specifically to identify possible differences in their degradation component
profiles. They were found to differ significantly in m-xylene content, which is
consistent with their respective production histories.
PMID- 10691662
TI - Distribution of aflatoxin in almonds. 2. Distribution in almonds with heavy
insect damage.
AB - The aflatoxin distribution function in individual insect-damaged NePlus Ultra
almonds was determined and found to be the sum of two distributions.
Substantially all almonds exhibited a positive aflatoxin level between 0.02 ng/g
(the detection level) and 0.3 ng/g, the precise form of this distribution
depending on the lot studied. In addition, 1/1000 of the nuts showed
contamination between 60 and 600 000 ng/g, independent of the lot. The latter
distribution showed a smooth decrease with log concentration in this range, with
no evidence of a minimum, as had been found previously for pistachios. No
distribution data between 0.3 and 60 ng/g could be obtained. The distribution
below 0.3 ng/g was assigned to contamination during post-harvest storage. The
distribution above 60 ng/g was tentatively assigned to navel orange worm damage
occurring when insects enter the kernel during split hulls late in the growing
season. Considerable additional work will be required to verify these
assignments.
PMID- 10691663
TI - Technological processes to decrease the allergenicity of peach juice and nectar.
AB - Among vegetable foods peach (Prunus persica) has been recognized as a significant
cause of allergy. The protein, which is considered to be the major peach
allergen, has been named Pru p 1. Because peaches are consumed both as fresh
fruits and after processing to obtain peach juice, nectar, jam, syrupy peach,
etc., research was carried out to identify a technological process for production
of hypo- or nonallergenic peach-based products. SDS-PAGE and immunoblotting
analysis of extracts prepared from four commercial peach nectars showed that the
Pru p 1 was not removed, and neither was its allergenic activity decreased by
technological treatments carried out for nectar production. Some treatments
oriented toward a removal of or, at least, a decrease in the allergenic power
were assumed and verified at laboratory scale. A variable considered was heat
treatment at 121 degrees C for 10 and 30 min: this treatment was not able to
decrease the allergenicity of the Pru p 1 protein. Furthermore, the protein band
was still present even after 60-min reaction with two different acidic proteases.
The two technological treatments that were found to decrease the major allergen
of peach were chemical lye peeling of fruits and ultrafiltration of juice through
membranes with suitable cutoff. On the basis of the results obtained from this
research, a processing flow sheet was defined to obtain hypoallergenic or
probably nonallergenic limpid juices and nectars. These products may represent,
besides finished foods, intermediates to obtain various products after addition
of further ingredients such as pectins, sugars, and fiber.
PMID- 10691664
TI - Conversion of cephapirin to deacetylcephapirin in milk and tissues of treated
animals.
AB - Cephapirin is one of six beta-lactam antibiotics approved for use in the
treatment of food-producing animals in the United States. When used for treatment
of mastitis by intramammary infusion, it is partially converted to a
microbiologically active metabolite identified as deacetylcephapirin (DACEP). The
degradation was followed in four cows with naturally acquired mastitis which were
treated with cephapirin. DACEP persisted longer than the parent compound in the
milk. When a calf was treated with cephapirin by intramuscular injection, the
compound was almost completely converted to DACEP in tissues. The deacetyl form
must be considered in the determination of residues in treated animals.
PMID- 10691665
TI - Antifeedant and mosquitocidal compounds from Delphinium x cultorum cv. Magic
fountains flowers.
AB - Six volatile compounds, ethylmethylbenzene (1), 1-isopentyl-2,4, 5
trimethylbenzene (2), 2-(hex-3-ene-2-one)phenylmethyl ketone (3), E and Z isomers
of 3-butylidene-3H-isobenzofuran-1-one (4 and 5), and 2-penten-1-ylbenzoic acid
(6), were isolated from the mosquitocidal hexane extract of Delphinium x cultorum
cv. Magic Fountains flowers. In addition, the ethyl acetate extract, which
displayed corn earworm antifeedant activity, yielded 4-hydroxybenzoic acid (7)
and bis(4-hydroxyphenyl)methanol (8). However, compounds 7 and 8 were not
biologically active.
PMID- 10691666
TI - Isoform patterns of chitinase and beta-1,3-glucanase in maturing corn kernels
(Zea mays L.) associated with Aspergillus flavus milk stage infection.
AB - Isoform patterns of chitinase and beta-1,3-glucanase of maturing kernels of
yellow dent corn (Pioneer 3394) infected with Aspergillus flavus at the milk
stage were investigated through polyacrylamide gel electrophoresis (PAGE).
Proteins on the sodium dodecyl sulfate (SDS) gel with an apparent molecular mass
range of 23-46 kDa were differentially present in the kernels infected with both
aflatoxin-producing and non-aflatoxin-producing strains of A. flavus. From in-gel
(native PAGE) enzyme activity assays, three bands corresponding to chitinase
isoforms and two bands corresponding to beta-1,3-glucanase isoforms were detected
in the infected kernels. One chitinase isoform of 29 kDa was present only in the
infected kernels, and another one of 28 kDa was present in both infected and
noninfected kernels. They were judged to be acidic on the basis of their
migration on an acrylamide isoelectric focusing (IEF) gel. For the beta-1,3
glucanase, one isoform of 35 kDa was present in both infected and noninfected
kernels, but another one, a 33 kDa isoform, was present only in the infected
kernels. Both acidic and basic beta-1,3-glucanase isoforms were detected in the
IEF gel. The results of this study are the first to demonstrate patterns of
enhanced or inducible proteins in maturing corn kernels in response to A. flavus
infection at the milk stage. The results also indicate that only particular
isoforms of the two hydrolytic enzymes are involved in the maturing corn kernels
infected at the milk stage with A. flavus.
PMID- 10691667
TI - Microbial glucosylation of thaxtomin A, a partial detoxification.
AB - Thaxtomin A (1) and B (2), the two major phytotoxins associated with the common
scab of potato disease, were transformed into C-14 linked beta-glucosides (3) and
(4), respectively, when individually incubated with cultures of Bacillus mycoides
in oatmeal broth at 26 degrees C. These biotransformation products when assayed
on aseptically produced potato minitubers proved to be much less phytotoxic than
the parent compounds.
PMID- 10691668
TI - Methyl jasmonate reduces chilling injury and maintains postharvest quality of
mango fruit.
AB - Exposure of mango (Mangifera indica cv. Tommy Atkins) fruit to methyl jasmonate
(MJ) vapors (10(-)(4) M) for 24 h at 25 degrees C reduced chilling injury during
subsequent storage for 21 days at 7 degrees C and after 5 days of shelf life at
20 degrees C. The chilling tolerance induced by MJ was positively correlated with
the reduction in the percent ion leakage of mango tissue. The overall quality of
MJ-treated fruit was also better than that of control fruit. MJ treatment
increased the total soluble solids but did not affect titratable acidity or pH.
MJ also did not change the normal climacteric rise in respiration, water loss,
and softening rates. The efficacy of MJ to reduce chilling injury and decay of
mango could be related to the tolerance induced at low temperature. It was
concluded that MJ treatment may prevent chilling injury symptoms of mango without
altering the ripening process.
PMID- 10691669
TI - Reducing phosphine after the smoking process using an oxidative treatment.
AB - This article gives a description of the setup in a laboratory of a pilot system
to reduce phosphine following the smoking process of foodstuffs. At present, this
fumigant is released into the atmosphere and causes serious damage to the
environment due to its transformation into aggressive compounds. However,
phosphine may prove a good alternative to methyl bromide, which will legally be
used as a fumigant until the year 2002, provided it is made inert after the
smoking process and transformed into nontoxic and easily disposable substances.
Oxidant solutions containing potassium permanganate or potassium bichromate in
suitable concentrations proved moderately effective in reducing phosphine. The
addition of traces of silver nitrate as a catalyst to the oxidant solutions
increased the efficiency in reducing the fumigant, although not completely. Thus
it was necessary to use a recycling system to decontaminate air from phosphine,
as such an apparatus ensures the complete reduction of phosphine. The
mathematical function describing how the concentration of phosphine varies in the
smoking chamber also makes it possible to estimate the time necessary to reduce a
phosphine concentration from any initial value to a fixed final value.
PMID- 10691670
TI - Enantiomeric synthesis of (S)-2-methylbutanoic acid methyl ester, apple flavor,
using lipases in organic solvent.
AB - Enantiomeric selective synthesis of (S)-2-methylbutanoic acid methyl ester, which
is known as a major apple and strawberry flavor, was performed from racemic 2
methylbutanoic acid using lipases in organic solvent. Among 20 lipases, lipase IM
20 (immobilized lipase of Rhizomucor miehei), lipase AP (Aspergillus niger), and
lipase FAP-15 (Aspergillus javanicus) exhibited higher enzymatic activities and
enantioselectivities and were selected for the synthesis of (S)-2-methylbutanoic
acid methyl ester. Using these enzymes, the reaction conditions such as
temperature and lyophilizing pH were optimized, and kinetic parameters were
determined. All of the reactions were performed in isooctane, which was
identified as the best reaction media for nonaqueous systems. At 20 degrees C
maximum enantiomeric excess was observed, while synthetic activity increased as
the temperature increased. Only lipases lyophilized at pH 5.5, 6. 0, 6.5, and 7.0
showed synthetic activity. In this pH range, enantioselectivities were not
influenced by the lyophilizing pH. The K(M,S) and K(M,R) values for ester
synthetic activity of lipase were 1120 and 1240 mM, respectively. Enzyme activity
was inhibited by (S)-2-methylbutanoic amide, and its K(i) was calculated as 84
mM. (S)-2-Methylbutanoic amide acted as a competitive inhibitor.
PMID- 10691671
TI - Enhanced organically bound chromium yeast production.
AB - This paper describes continuous and fed-batch fermentation protocols for enhanced
production of organically bound chromium yeast. During continuous fermentation,
several inorganic chromium compounds were evaluated. Sodium chromate demonstrated
the best chromium incorporation into yeast biomass without any precipitation in
the fermentation medium. During fed-batch fermentation, several sodium chromate
concentrations were evaluated at 1.1, 3.5, 5.9, 7.1, 8.3, and 10.8 g/L with
continuous or single-dose addition. For single-dose addition of sodium chromate,
some precipitation was observed for all concentrations, which reduced the
available chromium in the fermentation medium. Adapted strain C11-1, obtained
during continuous fermentation, produced higher biomass than the wild type but
significantly lowered chromium incorporation. Pilot-scale fermentation
demonstrated similar total chromium incorporation (2966 ppm) with lower biomass
production compared to benchtop fermentation performed at the same sodium
chromate addition.
PMID- 10691672
TI - Development of a monoclonal antibody-based cELISA for the analysis of
sulfadimethoxine. 1. Development and characterization of monoclonal antibodies
and molecular modeling studies of antibody recognition.
AB - Sulfonamide antibiotics are used to treat a variety of bacterial and protozoan
infections in cattle, swine, and poultry. Current residue methods for the
analysis of sulfonamides in animal-based food products include bioassays,
chromatographic methods (HPLC, GLC), and immunoassays. Most immunoassays have
employed highly specific polyclonal antibodies. In this paper, we describe the
isolation of monoclonal antibodies against sulfadimethoxine (SDM) that vary in
their sensitivities and cross-reactivities against a large number of
sulfonamides. The most sensitive monoclonal antibody, designated SDM-18, exhibits
an IC(50) value for SDM of 1.53 ppb. Another monoclonal antibody, designated SDM
44, exhibits IC(50) values for six sulfonamides well below the established
threshold level of 100 ppb for animal tissues. Molecular modeling studies of the
cross-reactive drugs suggest that, depending on the monoclonal antibody, both
steric and electronic features govern antibody binding. Due to the diversity of
these monoclonal antibodies, it should be possible to design both compound- and
class-specific monoclonal antibody-based immunoassays.
PMID- 10691673
TI - Development of a monoclonal antibody-based cELISA for the analysis of
sulfadimethoxine. 2. Evaluation of rapid extraction methods and implications for
the analysis of incurred residues in chicken liver tissue.
AB - Several rapid extraction methods were evaluated for use with a monoclonal
antibody-based competitive inhibition ELISA (cELISA) to detect sulfadimethoxine
(SDM) in chicken liver tissue. These methods included extraction of the samples
with (1) aqueous buffer with or without ultrafiltration, (2) acetonitrile/water,
(3) methanol/water, or (4) acetone. The organic extraction methods were evaluated
with or without solvent evaporation prior to dilution into assay buffer for the
cELISA. The aqueous-based extraction methods were compatible with the cELISA.
However, of the organic extraction methods, only the acetone liver extract with
solvent evaporation prior to analysis was compatible with the cELISA. The cELISA
method coupled to aqueous- or acetone-based sample extraction as well as an HPLC
method was evaluated for the analysis of chicken liver tissues fortified with SDM
at levels from 0.2 to 0.025 ppm. Mean SDM recoveries for the HPLC method and for
the cELISA method using samples prepared by aqueous extraction, aqueous
extraction and ultrafiltration, or acetone extraction, evaporation, and
reconstitution were 68.9, 95.7, 60.1, and 52.5%, respectively. For the analysis
of samples obtained from an SDM incurred residue study, HPLC and cELISA analysis
of the same organic extract gave results that were highly correlated (R(2) =
0.976; p < 0.0001). However, results obtained from the analysis of aqueous
extracts by cELISA did not correlate well with those obtained by HPLC (R(2) =
0.61, p > 0. 0006). This was attributed to the coextraction of cross-reactive SDM
related residues that were not quantified by the HPLC method. The presence of
these residues should be considered during data interpretation when ELISA methods
coupled with rapid aqueous extraction of samples are used in SDM residue
monitoring programs.
PMID- 10691674
TI - Effect of temperature and/or pressure on tomato pectinesterase activity.
AB - The activity of tomato pectinesterase (PE) was studied as a function of pressure
(0.1-900 MPa) and temperature (20-75 degrees C). Tomato PE was rather heat labile
at atmospheric pressure (inactivation in the temperature domain 57-65 degrees C),
but it was very pressure resistant. Even at 900 MPa and 60 degrees C the
inactivation was slower as compared to the same treatment at atmospheric
pressure. At atmospheric pressure, optimal catalytic activity of PE was found at
neutral pH and a temperature of 55 degrees C. Increasing pressure up to 300 MPa
increased the enzyme activity as compared to atmospheric pressure. A maximal
enzyme activity was found at 100-200 MPa combined with a temperature of 60-65
degrees C. The presence of Ca(2+) ions (60 mM) decreased the enzyme activity at
atmospheric pressure in the temperature range 45-60 degrees C but increased
enzyme activity at elevated pressure (up to 300 MPa). Maximal enzyme activity in
the presence of Ca(2+) ions was noted at 200-300 MPa in combination with a
temperature of 65-70 degrees C.
PMID- 10691675
TI - Effect of gamma-irradiation on phenolic compounds and phenylalanine ammonia-lyase
activity during storage in relation to peel injury from peel of Citrus clementina
hort. Ex. tanaka.
AB - The influence of gamma-irradiation on the content of phenolic compounds was
evaluated on Moroccan Citrus fruits (Citrus clementina Hort. ex. Tanaka) treated
at a mean dose of 0.3 kGy and stored for 49 days at 3 degrees C. The results show
that irradiation has enhanced the synthesis of total phenolic compounds and is
correlated with phenylalanine ammonia-lyase activity (PAL) during storage.
Accumulation of phenolic compounds in cells is demonstrated and may be explained
by the enhancement of PAL activity. HPLC/UV (diode array detector) analysis
demonstrated that hesperidin was the major flavanone and nobiletin and
heptamethoxyflavone were the major polymethoxylated flavones. Hesperidin is also
the major phenolic compound in clementines. Irradiation stimulates the
biosynthesis of hesperidin after 14 days of storage, corresponding to the maximum
of PAL activity. p-Coumaric acid was also identified, and its content was
particularly high in irradiated fruits after 49 days of storage. Accumulation of
flavonoids and p-coumaric acid could be related to a better resistance. The
percentage of losses due to peel injury "pitting" during storage was between 1
and 5% after 49 days of storage. The connections between irradiation, enzyme
activity, phenolic content, and peel injury are briefly discussed.
PMID- 10691676
TI - Specificity of papaya lipase in esterification with respect to the chemical
structure of substrates.
AB - Esterification, catalyzed by papaya (Carica papaya) lipase (CPL), was studied
with various alcohols and carboxylic acids under competitive conditions. Acids
studied were straight-chain saturates of different chain lengths, with octanoic
acid as the reference. Alcohols chosen were aliphatic straight-chain, branched,
secondary, tertiary, terpene, and aromatic alcohols of different chain lengths,
using 1-hexanol as the reference. The initial reaction rate increased with
increasing chain length of the acid from C4:0 to C18:0, followed by a slight
decrease with C20:0. In the case of alcohols, an optimum chain length of 8 carbon
atoms was obtained for the straight-chain aliphatic group (C2 to C16). Ethanol, 1
propanol, and secondary and tertiary alcohols showed rather low reactivity.
Branching of the alcohols was found not to affect the reactivity in
esterification; among the terpenes, beta-citronellol [(2E)-3, 7-dimethyl-6
octenol] and geraniol [(2E)-3,7-dimethylocta-2, 6-dien-1-ol] were found to be
more reactive than nerol [(2Z)-3, 7-dimethylocta-2,6-dien-1-ol]. The highest
reaction rate was found for the aromatic benzyl alcohol (phenylmethanol).
PMID- 10691677
TI - Immunological characterization of recombinant soy protein allergen produced by
Escherichia coli expression system.
AB - To elucidate the molecular mechanism of the allergenicity of soybean P34 protein
recognized as the most allergenic protein in soybean, the protein was expressed
in Escherichia coli transformed with a plasmid carrying P34 cDNA. SDS-PAGE
pattern showed that the molecular weight of the recombinant P34 was approximately
2 kDa less than that of the native soybean P34. The difference in the molecular
mass between these two proteins could be due to the native P34 in soybean being
glycosylated at position Asn(170), whereas the recombinant protein generated in
E. coli lacks this post-translational modification. Immunoblot analysis showed
that both soybean and recombinant P34 proteins cross-reacted not only with
polyclonal and monoclonal antibodies produced against P34 and crude soybean
protein but also with patients' sera. The results suggest that the recombinant
P34 is immunologically reactive, indicating that both proteins have similar
epitope structures. Thus, the recombinant P34 produced by the E. coli expression
system can be used as a standard allergen for molecular design to reduce the
allergenic structure.
PMID- 10691678
TI - Interaction of curcumin with phosphatidylcholine: A spectrofluorometric study
PMID- 10691679
TI - Structure-physicochemical function relationships of soybean beta-conglycinin
constituent subunits
PMID- 10691680
TI - The PPARs: from orphan receptors to drug discovery.
PMID- 10691681
TI - Novel ligands lacking a positive charge for the delta- and mu-opioid receptors.
AB - Recently we reported using minilibraries to replace Lys(9) [somatostatin (SRIF)
numbering] of the potent somatostatin agonist L-363,301 (c[-Pro-Phe-D-Trp-Lys-Thr
Phe-]) to generate the potent neurokinin receptor (NK-1) antagonist c[-Pro-Phe-D
Trp-p-F-Phe-Thr-Phe-]. This novel cyclic hexapeptide did not bind the SRIF
receptor. Thus, a single mutation converted L-363,301, a SRIF agonist with
potency ca. 2-8 times the potency of SRIF in laboratory animals,(24) into a
selective NK-1 receptor antagonist with an IC(50) of 2 nM in vitro. During the
screening of the same libraries for ligands of the delta-opioid receptor, we
identified four compounds (1-4) which represent a new class of delta-opioid
antagonists, some of which were also NK-1 receptor antagonists. The most potent
delta-opioid antagonist, c[-Pro-1-Nal-D-Trp-Tyr-Thr-Phe-] (2), showed a K(e)
value of 128 nM in the mouse vas deferens assay and a delta-receptor binding
affinity constant of 152 nM in the rat brain membrane binding assay. These
results are of interest because they represent a novel class of delta-opioid
antagonists and, like two previously reported delta-opioid antagonists, they lack
a positive charge. To examine further the requirement for a positive charge in
the delta-opioid ligands, we prepared two analogues of the beta-casomorphin
derived mixed mu-agonist/delta-antagonist, H-Dmt-c[-D-Orn-2-Nal-D-Pro-Gly-] (7),
in which we eliminated the positive charge either through formylation of the
primary amino group (5) or by the deletion of this N-terminal amino group (6).
These latter compounds proved to be delta-opioid antagonists with K(e) values in
the 16-120 nM range, as well as fairly potent mu-opioid antagonists (K(e)
approximately 200 nM). These six compounds provide the most convincing evidence
to date that there is no requirement for a positive charge in mu- and delta
opioid receptor antagonists. In addition, cyclic hexapeptide 4 lacks a phenolic
hydroxyl group. Taken together, these data suggest that the prevailing
assumptions about delta- and mu-opioid receptor binding need revision and that
the receptors for these opioid ligands have much in common with the NK-1 and
somatostatin receptors.
PMID- 10691682
TI - Phenyl beta-methoxyacrylates: a new antimalarial pharmacophore.
AB - Phenyl beta-methoxyacrylates, linked to an aromatic ring via an olefinic bridge,
have been identified as novel, potentially inexpensive, antimalarial agents. The
compounds are believed to exert their activity by inhibition of mitochondrial
electron transport at the cytochrome bc(1) complex. A series of compounds have
been synthesized to define structure-activity relationships affecting
antimalarial activity. It was found that the beta-methoxyacrylate was required
ortho to the linker and the optimal bridge was (E,E)-butadiene. Compounds in
which the second aromatic ring was ortho-substituted or ortho,para-disubstituted
gave optimal potency. Several compounds were identified with potency that is
superior to that of chloroquine both in culture and in a murine malaria model.
PMID- 10691683
TI - Opiate aromatic pharmacophore structure-activity relationships in CTAP analogues
determined by topographical bias, two-dimensional NMR, and biological activity
assays.
AB - Topographically constrained analogues of the highly mu-opioid-receptor-selective
antagonist CTAP (H-D-Phe-c[Cys-Tyr-D-Trp-Arg-Thr-Pen]-Thr-NH(2), 1) were prepared
by solid-phase peptide synthesis. Replacement of the D-Phe residue with
conformationally biased beta-methyl derivatives of phenylalanine or tryptophan
(2R,3R; 2R,3S; 2S,3R; 2S,3S) yielded peptides that displayed widely varying types
of biological activities. In an effort to correlate the observed biological
activities of these analogues with their structures, two-dimensional (1)H NMR and
molecular modeling was performed. Unlike the parent (1), which is essentially a
pure mu antagonist with weak delta agonist activities in the MVD bioassay, the
diastereomeric beta-MePhe(1)-containing peptides exhibited simultaneous delta
agonism and mu antagonism by the (2R,3R)-containing isomer 2; mu antagonism by
the (2R,3S)-containing isomer 3; weak mu agonism by the (2S,3R)-containing isomer
4; and delta agonism by the (2S,3S)-containing isomer 5. Incorporation of beta
MeTrp isomers into position 1 led to peptides that were mu antagonists (2R,3R),
8; (2R,3S), 9, or essentially inactive (<10%) in the MVD and GPI assays (2S,3R),
10; (2S,3S), 11. Interestingly, in vivo antinociceptive activity was predicted by
neither MVD nor GPI bioactivity. When D-Trp was incorporated in position 1, the
result (7) is a partial, yet relatively potent mu agonist which also displayed
weak delta agonist activity. Molecular modeling based on 2D NMR revealed that low
energy conformers of peptides with similar biological activities had similar
aromatic pharmacophore orientations and interaromatic distances. Peptides that
exhibit mu antagonism have interaromatic distances of 7.0-7.9 A and have their
amino terminal aromatic moiety pointing in a direction opposite to the direction
that the amino terminus points. Peptides with delta opioid activity displayed an
interaromatic distance of <7 A and had their amino terminal aromatic moiety
pointing in the same direction as the amino terminus.
PMID- 10691684
TI - Chiral nonsteroidal affinity ligands for the androgen receptor. 1. Bicalutamide
analogues bearing electrophilic groups in the B aromatic ring.
AB - A series of chiral analogues of bicalutamide bearing electrophilic groups
(isothiocyanate, N-chloroacetyl, and N-bromoacetyl) on aromatic ring B of the
parent molecule were synthesized. These compounds were designed as affinity
ligands for the androgen receptor (AR). We prepared the (R)- and (S)-optical
isomers of these compounds as pure enantiomers. The AR binding affinities of
these compounds were measured in a competitive binding assay with the
radiolabeled high-affinity AR ligand, [(3)H]mibolerone. In accordance with our
previous results for the enantiomers of bicalutamide, we found that all (R)
isomers demonstrated much higher binding affinity to the AR as compared to their
corresponding (S)-isomers. The para-substituted affinity ligands in ring B bound
the AR with higher affinities than the corresponding meta-substituted analogues.
Oxidation of thioester affinity ligands to their sulfonyl analogues for the para
substituted compounds decreased AR binding affinities and similar modification
increased binding affinities for corresponding meta-analogues. The least potent
para-substituted sulfonyl compounds had higher AR binding affinities than the
most potent meta-substituted sulfonyl compounds. Overall, the para-substituted
unoxidized molecules demonstrated the highest AR binding affinity. Subsequent
research using AR exchange assays and Scatchard analyses showed that the
isothiocyanate affinity ligands (R)-7, (R)-9, and (R)-10 reported herein are the
first specific chemoaffinity ligands for the AR.
PMID- 10691685
TI - Synthesis and human beta-adrenoceptor activity of 1-(3,5-diiodo-4- methoxybenzyl)
1,2,3,4-tetrahydroisoquinolin-6-ol derivatives in vitro.
AB - Trimetoquinol (1, TMQ) is a potent nonselective beta-adrenergic receptor (AR)
agonist and a thromboxane A(2)/prostaglandin endoperoxide (TP) receptor
antagonist, while 3',5'-diiodo-TMQ (2) exhibits beta(3)-AR selectivity. In search
of selective beta(3)-AR agonists as potential drugs for the treatment of human
obesity and type II diabetes mellitus, a series of 1-(3, 5-diiodo-4
methoxybenzyl)-1,2,3,4-tetrahydroisoquinolin-6-ols has been prepared and
evaluated for their biological activities at human beta(1)-, beta(2)-, and
beta(3)-ARs expressed in Chinese hamster ovary (CHO) cells. The compounds have
been synthesized by the Bischler-Napieralski cyclization of corresponding amides
followed by NaBH(4) reduction, and the halogens in the aromatic ring A were
introduced by direct halogenation of protected compound 11. Whereas halogen
substitution in ring A reduced either potency or intrinsic activity on beta(3)
AR, the non-halogen-substituted compounds 8 and 10 were potent, selective, nearly
full agonists for beta(3)-AR.
PMID- 10691686
TI - Binding and preliminary evaluation of 5-hydroxy- and 10-hydroxy-2,3, 12,12a
tetrahydro-1H-[1]benzoxepino[2,3,4-ij]isoquinolines as dopamine receptor ligands.
AB - The N-methyl, N-ethyl, and N-n-propyl derivatives of 5-hydoxy- and 10-hydroxy
2,3,12,12a-tetrahydro-1H-[1]benzoxepino[2,3, 4-ij]isoquinolines were prepared as
monophenolic ligands for the dopamine receptor and evaluated for their affinity
at D(1)-like and D(2)-like subtypes. All compounds showed very low D(1)
affinities. This could be ascribed to the absence of a catechol nucleus or of the
beta-phenyldopamine pharmacophore. Only the N-methyl-5-hydroxy- (5a), N-methyl-10
hydroxy- (6a), and N-methyl-4-bromo-10-methoxy-2,3, 12,12a-tetrahydro-1H
[1]benzoxepino[2,3,4-ij]isoquinolines (26a) bound the D(2) receptors with low
affinity, in the same range as dopamine. In compounds 5a and 6a, the 2-(3
hydroxyphenyl)ethylamine moiety does not meet the requirements of the D(2)
agonist pharmacophore: namely, the 2-(3-hydroxyphenyl)ethylamine does not reach
the trans, fully extended conformation. The three compounds did not interact with
recombinant human D(4) receptors, and only 5a showed low affinity for rat
recombinant D(3) receptors. Analysis of the influence of Na(+) on [(3)H]spiperone
binding showed that 5a displays a potential dopamine D(2) agonist profile,
whereas 6a probably has a dopamine D(2) antagonist activity. The D(2) agonist
activity of 5a was proved by the effects on prolactin release from primary
cultures of rat anterior pituitary cells.
PMID- 10691687
TI - Hypocholesterolemic and hypolipidemic activity of some novel morpholine
derivatives with antioxidant activity.
AB - In this investigation, we study the synthesis and the evaluation of antioxidant
and hypocholesterolemic activity of a number of 2-biphenylyl morpholine
derivatives, which are structurally similar to some substituted morpholines
possessing antioxidant activity, as well as to hypocholesterolemic 3-biaryl
quinuclidines. The novel derivatives are found to inhibit the ferrous/ascorbate
induced lipid peroxidation of microsomal membrane lipids, the most potent
derivative, 2-(4-biphenyl)-4-methyl-octahydro-1,4-benzoxazin-2-ol (compound 7),
having an IC(50) value of 250 microM. In addition, these compounds demonstrate
hypocholesterolemic and hypolipidemic action. The most active compound (7)
decreases total cholesterol, low density lipoprotein, and triglycerides in plasma
of Triton WR-1339 induced hyperlipidemic rats by 54%, 51%, and 49%, respectively,
at 28 micromol/kg (ip). The above results indicate that the new molecules may be
proven useful as leads for the design of novel compounds as potentially
antiatherogenic factors.
PMID- 10691688
TI - Steroidal affinity labels of the estrogen receptor alpha. 4. Electrophilic 11beta
aryl derivatives of estradiol.
AB - Ten electrophilic estradiol 11beta-aryl derivatives were synthesized, with three
different types of 11beta-substituent: (i) pOO(CH(2))(2)X (compounds: 6, X =
OSO(2)CH(3); 7, X = I; 13, X = NHCOCH(2)Cl; 15, X = N(CH(3))COCH(2)Br; and 16, X
= N(CH(3))COCH(2)Cl); (ii) pOO(CH(2))(5)X (compounds: 17, X = I; 20, X =
NHCOCH(2)Br; and 22, X = N(CH(3))COCH(2)Br); and (iii) pOC(triple bond)CCH(2)X
(compounds: 27, X = NHCOCH(2)Cl; and 29, X = N(CH(3))COCH(2)Cl). The range of
their apparent affinity constants for binding the lamb uterine estrogen receptor
alpha (ERalpha) was 3-40% that of estradiol. Six electrophiles, chloroacetamides
13, 16, 27, and 29, iodide 17, and bromoacetamide 20 (whose arm linking the
electrophilic carbon to the 11beta-phenyl group includes at least six bonds),
were able to irreversibly inhibit the binding of [(3)H]estradiol to ER (25-60%
decrease in binding sites), with the following compound effectiveness order: 17 <
13 < 16 approximately 20 approximately 27 approximately 29. Mesylate 6, iodide 7
(whose linking arm includes only three bonds), and bromoacetamides 15 and 22
(which differ from 16 by the Cl to Br change and from 20 by the NH to NCH(3)
change, respectively) were much less effective (<10% decrease in binding sites,
if any). The fact that the inactivation of estradiol-binding sites by the six
electrophiles was totally prevented by estradiol indicated that they were ER
affinity labeling agents. When ER was modified by methyl methanethiosulfonate, an
SH-specific reagent, the different compounds led to very contrasting results in
ER affinity labeling. With modified ER, iodide 17 and chloroacetamides 27 and 29
were practically inactive, chloroacetamides 13 and 16 and bromoacetamide 20 were
still active but less effective than on the native ER, whereas tertiary
bromoacetamides 15 and 22, found to be practically inactive on native ER, became
the most effective electrophiles ( approximately 45% and approximately 65%
binding sites inactivated, respectively). The results indicate that in the
steroid-filled hormone-binding pocket: (i) nucleophilic residues are localized on
the beta-side but relatively remote from the steroid nucleus (distance from C-11
> "seven bonds"); (ii) relatively discrete changes in the electrophilic
functionality, such as Cl to Br or NH to NCH(3) of haloacetamido compounds, can
markedly modify the positioning of the electrophilic center which could no longer
react with the nucleophilic residues; and (iii) cysteine residues (probably
homologues of human ERalpha cysteine 381 and/or cysteine 530) are, at least
partly, the covalent attachment sites of the electrophiles. Moreover,
modification of cysteine residues by methyl methanethiosulfonate changes the
structure of the hormone-binding pocket, whose labeling by the various
electrophiles is profoundly altered.
PMID- 10691689
TI - Inhibitors of topoisomerase II based on the benzodiimidazole and
dipyrroloimidazobenzimidazole ring systems: controlling DT-diaphorase reductive
inactivation with steric bulk.
AB - Described herein are the synthesis, cytotoxic properties, and topoisomerase II
inhibition assays of benzodiimidazole and dipyrroloimidazobenzimidazole
structural variants of the pyrrolo[1, 2-a]benzimidazole or APBI ring system.
These ring variants were designed to inhibit topoisomerase II, much as the APBIs
are able to do. Since only the quinone form of the APBIs can intercalate DNA, two
electron reduction to the hydroquinone by DT-diaphorase is known to deactivate
these compounds. Indeed, the APBIs possess a high inverse correlation with the
cellular concentration of DT-diaphorase. Therefore one feature of the ABPI
structural variants is the excessive bulk about the quinone ring, which was
predicted to diminish DT-diaphorase substrate activity. Another feature is the
presence of one or two alkylating centers, which would permit alkylation of DNA
and/or topoisomerase II. Inhibition assays for topoisomerase II-mediated
relaxation of supercoiled DNA indicate that the benzodiimidazole and
dipyrroloimidazobenzimidazole quinone ring systems are catalytic inhibitors of
topoisomerase II. Both quinone systems exhibit cytotoxicity perhaps due to the
lack of inactivation by DT-diaphorase as well as topoisomerase II inhibition. One
quinone displayed the novel feature of cytotoxicity selectively against melanoma
cell lines. In conclusion, the benzodiimidazole and dipyrroloimidazobenzimidazole
quinone ring systems will be subjected to future analogue development and
structure-activity studies.
PMID- 10691690
TI - Synthesis, biodistribution, and primate imaging of fluorine-18 labeled 2beta
carbo-1'-fluoro-2-propoxy-3beta-(4-chlorophenyl)tr opanes. Ligands for the
imaging of dopamine transporters by positron emission tomography.
AB - 2beta-(R)-Carbo-1-fluoro-2-propoxy-3beta-(4-chlorophenyl) tro pane ((R)-FIPCT, R
6) and 2beta-(S)-carbo-1-fluoro-2-propoxy-3beta-(4-chlorophenyl) tro pane ((S)
FIPCT, S-6) were prepared and evaluated in vitro and in vivo for dopamine
transporter (DAT) selectivity and specificity. High specific activity [(18)F](R)
FIPCT and [(18)F](S)-FIPCT were synthesized in 5% radiochemical yield (decay
corrected to end of bombardment (EOB)) by preparation of the precursors 2beta
carbo-R-1-mesyloxy-2-propoxy-3beta-(4-chlorop hen yl)tropane (R-12) and 2beta
carbo-S-1-mesyloxy-2-propoxy-3beta-(4-chlorop hen yl)tropane (S-12) followed by
treatment with no carrier-added potassium[(18)F]fluoride and kyrptofix K222 in
acetonitrile. Competition binding in cells stably expressing the transfected
human DAT and serotonin transporter (SERT) labeled by [(3)H]WIN 35428 and
[(3)H]citalopram, respectively, demonstrated the following order of DAT affinity
(K(i) in nM): GBR 12909 (0.36) > CIT (0.48) > (S)-FIPCT (0.67) >> (R)-FIPCT
(3.2). The affinity of (S)-FIPCT and (R)-FIPCT for SERT was 127- and 20-fold
lower, respectively, than for DAT. In vivo biodistribution studies were performed
in male rats and demonstrated that the brain uptake of [(18)F](R)-FIPCT and
[(18)F](S)-FIPCT were selective and specific for DAT rich regions (caudate and
putamen). PET brain imaging studies in monkeys demonstrated high [(18)F](R)-FIPCT
and [(18)F](S)-FIPCT uptake in the caudate and putamen which resulted in caudate
to-cerebellum and putamen-to-cerebellum ratios of 2.5-3.5 at 115 min. [(18)F](R)
FIPCT uptake in the caudate/putamen achieved transient equilibrium at 75 min. In
an imaging experiment with [(18)F](S)-FIPCT in a rhesus monkey with its left
hemisphere lesioned with MPTP, radioactivity was reduced to background in the
caudate and putamen of the lesioned hemisphere. The high specific activity one
step radiolabeling preparation and high specificity and selectivity of [(18)F](R)
FIPCT and [(18)F](S)-FIPCT for DAT indicate [(18)F](R)-FIPCT and [(18)F](S)-FIPCT
are potential radioligands for mapping brain DAT in humans using PET.
PMID- 10691691
TI - Diamino benzo[b]thiophene derivatives as a novel class of active site directed
thrombin inhibitors. 5. Potency, efficacy, and pharmacokinetic properties of
modified C-3 side chain derivatives.
AB - A systematic investigation of the structure-activity relationships of the C-3
side chain of the screening hit 1a led to the identification of the potent
thrombin inhibitors 23c, 28c, and 31c. Their activities (1240, 903, and 1271 x
10(6) L/mol, respectively) represent 2200- and 2900-fold increases in potency
over the starting lead 1a. This activity enhancement was accomplished with an
increase of thrombin selectivity. The in vitro anticoagulant profiles of
derivatives 28c and 31c were determined, and they compare favorably with the
clinical agent H-R-1-[4aS, 8aS]perhydroisoquinolyl-prolyl-arginyl aldehyde (D-Piq
Pro-Arg-H; 32). The more potent members of this series have been studied in an
arterial/venous shunt (AV shunt) model of thrombosis and were found to be
efficacious in reducing clot formation. However, their efficacy is currently
limited by their rapid and extensive distribution following administration.
PMID- 10691692
TI - Inhibitors of tripeptidyl peptidase II. 2. Generation of the first novel lead
inhibitor of cholecystokinin-8-inactivating peptidase: a strategy for the design
of peptidase inhibitors.
AB - The cholecystokinin-8 (CCK-8)-inactivating peptidase is a serine peptidase which
has been shown to be a membrane-bound isoform of tripeptidyl peptidase II (EC
3.4.14.10). It cleaves the neurotransmitter CCK-8 sulfate at the Met-Gly bond to
give Asp-Tyr(SO(3)H)-Met-OH + Gly-Trp-Met-Asp-Phe-NH(2). In seeking a reversible
inhibitor of this peptidase, the enzymatic binding subsites were characterized
using a fluorimetric assay based on the hydrolysis of the artificial substrate
Ala-Ala-Phe-amidomethylcoumarin. A series of di- and tripeptides having various
alkyl or aryl side chains was studied to determine the accessible volume for
binding and to probe the potential for hydrophobic interactions. From this
initial study the tripeptides Ile-Pro-Ile-OH (K(i) = 1 microM) and Ala-Pro-Ala-OH
(K(i) = 3 microM) and dipeptide amide Val-Nvl-NHBu (K(i) = 3 microM) emerged as
leads. Comparison of these structures led to the synthesis of Val-Pro-NHBu (K(i)
= 0.57 microM) which served for later optimization in the design of butabindide,
a potent reversible competitive and selective inhibitor of the CCK-8-inactivating
peptidase. The strategy for this work is explicitly described since it
illustrates a possible general approach for peptidase inhibitor design.
PMID- 10691693
TI - Palladium-catalyzed cross-coupling reactions for the synthesis of 6, 8
disubstituted 1,7-naphthyridines: a novel class of potent and selective
phosphodiesterase type 4D inhibitors.
AB - Recently, four subtypes of the human phosphodiesterase type 4 (PDE4A-D) enzyme
have been described. So far, only very few PDE4 subtype-selective inhibitors are
known. Herein, we describe the synthesis of 6,8-disubstituted 1,7-naphthyridines
and their characterization as potent and selective inhibitors of PDE4D which
suppress the oxidative burst in human eosinophils with IC(50) values as low as
0.7 nM. SAR development and the extended use of palladium-catalyzed cross
coupling reactions led to compound 11 which inhibited human PDE4D with an IC(50)
value of 1 nM. Thus, compound 11 was 55, 175, and 1000 times more potent in
inhibiting PDE4D over PDE4B, PDE4A, and PDE4C. In a Brown Norway rat model of
allergic asthma, compound 11 when given by the oral route (1 mg/kg) reduced by
more than 50% the influx of eosinophils, T-cells, and neutrophils into
bronchoalveolar lavage fluid (BALF) samples obtained from antigen-challenged
animals. Thus, PDE4D-selective inhibitors of the 1,7-naphthyridine class have the
potential as an oral therapy for treating asthma.
PMID- 10691694
TI - Benzyl derivatives of 2,1,3-benzo- and benzothieno[3,2-a]thiadiazine 2,2
dioxides: first phosphodiesterase 7 inhibitors.
AB - The synthesis of a new family of benzyl derivatives of 2,1,3-benzo- and
benzothieno[3,2-a]thiadiazine 2,2-dioxides was achieved. The biological data
revealed the first heterocyclic family of compounds with PDE 7 inhibitory
properties appearing to be a new objective for the treatment of T-cell-dependent
disorders. The IC(50) values or percent inhibition values of the compounds
against PDE 7 were calculated by testing them against human recombinant PDE 7
expressed in S. cerevisiae. In this expression system the only cyclic nucleotide
hydrolyzing activity present in cell extracts corresponded to human PDE 7.
Isoenzyme selectivity PDE 7 versus PDE 4 and PDE 3 was also measured. Considering
simultaneously inhibition of the three different isoenzymes, monobenzyl
derivatives 15 and 23 showed interesting PDE 7 potency (around 10 microM);
although not statistically significant, a trend toward selectivity with respect
to PDE 3 and PDE 4 was obtained. Benzothiadiazine 16, although less potent at PDE
7 (IC(50) = 25 microM), also showed a trend of selectivity toward PDE 3 and PDE
4. These compounds are considered the best leads for further optimization.
PMID- 10691695
TI - Heteroarylmethoxyphenylalkoxyiminoalkylcarboxylic acids as leukotriene
biosynthesis inhibitors.
AB - A novel series of heteroarylmethoxyphenylalkoxyiminoalkylcarboxylic acids was
studied as leukotriene biosynthesis inhibitors. A hypothesis of structure
activity optimization by insertion of an oxime moiety was investigated using REV
5901 as a starting point. A systematic structure-activity optimization showed
that the spatial arrangement and stereochemistry of the oxime insertion unit
proved to be important for inhibitory activity. The promising lead, S-(E)-11,
inhibited LTB(4) biosynthesis in the intact human neutrophil with IC(50) of 8 nM
and had superior oral activity in vivo, in a rat pleurisy model (ED(50) = 0.14
mg/kg) and rat anaphylaxis model (ED(50) = 0.13 mg/kg). In a model of lung
inflammation, S-(E)-11 blocked LTE(4) biosynthesis (ED(50) of 0.1 mg/kg) and
eosinophil influx (ED(50) of 0.2 mg/kg). S-(E)-11 (A-93178) was selected for
further preclinical evaluation.
PMID- 10691696
TI - A new class of conformationally rigid analogues of 4-amino-5-halopentanoic acids,
potent inactivators of gamma-aminobutyric acid aminotransferase.
AB - Recently, we found (Qiu, J.; Pingsterhaus, J. M.; Silverman, R. B. J. Med. Chem.
1999, 42, 4725-4728) that conformationally rigid analogues of the GABA
aminotransferase (GABA-AT) inactivator vigabatrin were not inactivators of GABA
AT. To determine if this is a general phenomenon of GABA-AT inactivators, several
mono- and di-halogen-substituted conformationally rigid analogues (7-15) of other
GABA-AT inactivators, 4-amino-5-halopentanoic acids, were synthesized as
potential inactivators of GABA-AT. Four of them, (+)-7, (-)-9, (+)-10, and (+)
15, were inactivators, although not as potent as the corresponding open-chain
analogues. The maximal inactivation rate constants, k(inact), for the fluoro- and
bromo-substituted analogues were comparable, indicating that cleavage of the C-X
bond is not rate determining. Consistent with that observation is the finding
that [3-(2)H]-10 exhibits a deuterium isotope effect on inactivation of 3.3,
suggesting that C-H bond cleavage is the rate-determining step. The rate of
inactivation of GABA-AT by the fluorinated analogue 7 is 1/15 that of
inactivation by the corresponding open-chain analogue, 4-amino-5-fluoropentanoic
acid (3a). Whereas inactivation by 3a releases only one fluoride ion,
inactivation by 7 releases 148 fluoride ions, accounting for the less efficient
inactivation rate. Inactivation leads to covalent attachment of 2 equiv of
inactivator after gel filtration; upon urea denaturation, 1 equiv of
radioactivity remains bound to the enzyme. This suggests that, unlike the open
chain anlogue, the conformationally rigid analogue becomes, at least partially,
attached to an active-site residue. It appears that the conformational constraint
has a larger effect on inactivators that inactivate by a Michael addition
mechanism than by an enamine mechanism.
PMID- 10691697
TI - Structure-activity relationship studies on 1-[2-(4
Phenylphenoxy)ethyl]pyrrolidine (SC-22716), a potent inhibitor of leukotriene
A(4) (LTA(4)) hydrolase.
AB - Leukotriene B(4) (LTB(4)) is a pro-inflammatory mediator that has been implicated
in the pathogenesis of a number of diseases including inflammatory bowel disease
(IBD) and psoriasis. Since the action of LTA(4) hydrolase is the rate-limiting
step for LTB(4) production, this enzyme represents an attractive pharmacological
target for the suppression of LTB(4) production. From an in-house screening
program, SC-22716 (1, 1-[2-(4-phenylphenoxy)ethyl]pyrrolidine) was identified as
a potent inhibitor of LTA(4) hydrolase. Structure-activity relationship (SAR)
studies around this structural class resulted in the identification of a number
of novel, potent inhibitors of LTA(4) hydrolase, several of which demonstrated
good oral activity in a mouse ex vivo whole blood assay.
PMID- 10691698
TI - The cyclohexene ring system as a furanose mimic: synthesis and antiviral activity
of both enantiomers of cyclohexenylguanine.
AB - Both enantiomers of cyclohexenylguanine were synthesized in a stereospecific way
starting from the same starting material: R-(-)-carvone. Both compounds showed
potent and selective anti-herpesvirus activity (HSV-1, HSV-2, VZV, CMV). The
binding of both cyclohexene nucleosides in the active site of HSV-1 thymidine
kinase was investigated, and a model for the binding of both enantiomers is
proposed. The amino acids involved in binding of the optical antipodes are the
same, but the interaction energy of both enantiomers is slightly different. This
may be attributed to the interaction of the secondary hydroxyl function of the
nucleoside analogues with Glu-225. Structural analysis has demonstrated the
flexibility of the cyclohexenyl system, and this may be considered as an
important conformational characteristic explaining the potent antiviral activity.
PMID- 10691699
TI - Acyclic analogues of deoxyadenosine 3',5'-bisphosphates as P2Y(1) receptor
antagonists.
AB - P2Y(1) receptors are activated by ADP and occur on endothelial cells, smooth
muscle, epithelial cells, lungs, pancreas, platelets, and in the central nervous
system. With the aid of molecular modeling, we have designed nucleotide analogues
that act as selective antagonists at this subtype. The present study has tested
the hypothesis that acyclic modifications of the ribose ring, proven highly
successful for nucleoside antiviral agents such as gancyclovir, are generalizable
to P2Y receptor ligands. Specifically, the binding site of the P2Y(1) receptor
was found to be sufficiently accommodating to allow the substitution of the
ribose group with acyclic aliphatic and aromatic chains attached to the 9
position of adenine. Three groups of adenine derivatives having diverse side
chain structures, each containing two symmetrical phosphate or phosphonate
groups, were prepared. Biological activity was demonstrated by the ability of the
acyclic derivatives to act as agonists or antagonists in the stimulation of
phospholipase C in turkey erythrocyte membranes. An acyclic N(6)-methyladenine
derivative, 2-[2-(6-methylamino-purin-9-yl)-ethyl]-propane-1, 3
bisoxy(diammoniumphosphate) (10), containing an isopentyl bisphosphate moiety,
was a full antagonist at the P2Y(1) receptor with an IC(50) value of 1.60 micro?.
The corresponding 2-Cl derivative (11) was even more potent with an IC(50) value
of 0.84 microM. Homologation of the ethylene group at the 9-position to 3-5
methylene units or inclusion of cis- or trans-olefinic groups greatly reduced
antagonist potency at the P2Y(1) receptor. Analogues containing a diethanolamine
amide group and an aryl di(methylphosphonate) were both less potent than 10 as
antagonists, with IC(50) values of 14 and 16 microM, respectively, and no agonist
activity was observed for these analogues. Thus, the ribose moiety is clearly not
essential for recognition by the turkey P2Y(1) receptor, although a cyclic
structure appears to be important for receptor activation, and the acyclic
approach to the design of P2 receptor antagonists is valid.
PMID- 10691700
TI - Conjugated enynes as nonaromatic catechol bioisosteres: synthesis, binding
experiments, and computational studies of novel dopamine receptor agonists
recognizing preferentially the D(3) subtype.
AB - To evaluate nonaromatic catechol bioisosteres, the conformationally restrained
enynes 1 and enediynes 2 were synthesized via palladium-catalyzed coupling as the
key reaction step. Subsequent receptor binding studies at the dopamine receptor
subtypes D(1), D(2 long), D(2 short), D(3), and D(4) showed highly interesting
binding profiles for the enynes 1a and 1b when compared to dopamine. At the
guanine nucleotide-sensitive high-affinity binding site of the D(3) receptor, the
target compound 1b (K(i) = 5.2 nM) was 10-fold more potent than dopamine but less
potent at the D(2) and D(4) subtypes. In contrast to dopamine the agonists 1a and
1b showed strong selectivity for the receptors of the D(2) family (D(2)-D(4)). As
far as we know, this study represents the first report on nonaromatic dopamine
agonists. Comparison of molecular electrostatic potentials, derived from
semiempirical molecular orbital calculations, and lipophilicity maps was
performed.
PMID- 10691701
TI - Identification of deoxymiroestrol as the actual rejuvenating principle of "Kwao
Keur", Pueraria mirifica. The known miroestrol may be an artifact.
AB - Miroestrol (1) has been isolated previously as an active principle from "Kwao
Keur" (Pueraria mirifica), a rejuvenating folk medicine from Thailand.
Reinvestigation using bioassay-guided purification has resulted in the isolation
of a new potent phytoestrogen, deoxymiroestrol (2). The facile aerial oxidation
of 2 into 1 suggests the possibility that 1 may be an artifact.
PMID- 10691702
TI - New circulin macrocyclic polypeptides from Chassalia parvifolia.
AB - Four new macrocyclic polypeptides were isolated and identified from an extract of
the tropical tree Chassalia parvifolia. Circulins C-F are 29-30 amino acid cyclic
peptides in which the entire primary amino acid chain is covalently cyclized via
peptide bonds. Their structures were deduced from a combination of FABMS
analyses, N-terminal Edman degradation, endoproteinase digestion, and amino acid
analyses. All the peptides share a high degree of sequence homology and contain
six cysteine residues forming three intramolecular disulfide bridges. Circulins C
F inhibited the cytopathic effects of in vitro HIV-1 infection with EC(50) values
of 50-275 nM.
PMID- 10691703
TI - Rearrangement of O-cinnamoyltaxicin I to a novel C-13 spiro-taxane.
AB - During the large-scale synthesis of an O-cinnamoyltaxicin I acetonide, an
intermediate for the semisynthesis of 7-deoxypaclitaxel derivatives, side-product
3 was formed via a vinylogous retro-aldol reaction and a long-range hydride shift
from O-cinnamoyltaxicin I (1) under alkaline reaction conditions. Compound 3 has
two hemi-acetal bridges at C-1,C-9 and C-10,C-13. Compound 4 was formed from side
product 3 under acidic reaction conditions and is the first C-13 spiro-taxane
described in the literature. This spiro-taxane has two acetal bridges between C
1, C-13 and C-10,C-13.
PMID- 10691704
TI - Secobotrytriendiol and related sesquiterpenoids: new phytotoxic metabolites from
Botrytis cinerea.
AB - Six new sesquiterpenoid metabolites (1, 3-7) have been isolated from Botrytis
cinerea. Their structures were elucidated by means of MS and extensive NMR
studies. The phytotoxic activities of these new products have been evaluated.
PMID- 10691705
TI - Biosynthesis of 4'-O-methylpyridoxine (Ginkgotoxin) from primary precursors.
AB - Cell suspension cultures of Ginkgo biloba and Albizia tanganyicensis were
investigated for the presence of 4'-O-methylpyridoxine (ginkgotoxin, 2), the 4'-O
methyl derivative of vitamin B(6) (pyridoxine, 1). The cultures produced the
toxin even in the absence of vitamin B(6) (a common additive to plant cell
culture media). This indicates that the pyridoxine ring system of ginkgotoxin is
synthesized de novo by the cultured cells. A feeding experiment with D-[U
(13)C(6)]glucose revealed that the mode of incorporation of label into the
pyridoxine moiety of 2 matched that observed for 1 in Escherichia coli. Thus, the
data obtained in this investigation provide independent proof supporting the
current hypothesis on vitamin B(6) biosynthesis. The 4'-O-methyl group of
ginkgotoxin (2) was labeled from L-[methyl-(13)C(1)]methionine. This indicates
that ginkgotoxin is likely to be derived by 4'-O-methylation of pyridoxine (1).
The G. biloba cell suspension culture may be a suitable system to get further
insight into vitamin B(6) and/or ginkgotoxin biosynthesis.
PMID- 10691706
TI - Quinolizidine alkaloids from Sophora alopecuroides.
AB - A new matrine-type alkaloid, 7alpha-hydroxysophoramine (1), was isolated from the
aerial parts of Sophora alopecuroides together with eight known alkaloids, 12beta
hydroxysophocarpine (2), sophoramine (3), 14beta-hydroxymatrine, matrine,
sophoridine, sophocarpine, adenocarpine, and baptifoline. The structures of
compounds 1-3 were confirmed through single-crystal X-ray diffraction analysis.
PMID- 10691707
TI - Novel polycyclic guanidine alkaloids from two marine sponges of the genus
Monanchora.
AB - Two marine sponges of the genus Monanchora (Poecilosclerida, Crambeidae) have
been found to contain new polycyclic guanidine alkaloids bearing the (5,6,8b)
triazaperhydroacenaphthylene skeleton. Their structures have been determined by
detailed spectroscopic analysis. Dehydrobatzelladine C (1) has been isolated from
M. arbuscula and crambescidins 359 (2) and 431 (3) from M. unguiculata. The
chemotaxonomic implications of these findings are discussed.
PMID- 10691708
TI - Yanucamides A and B, two new depsipeptides from an assemblage of the marine
cyanobacteria Lyngbya majuscula and Schizothrix species.
AB - Yanucamides A (1) and B (2) were isolated from the lipid extract of a Lyngbya
majuscula and Schizothrixsp. assemblage collected at Yanuca Island, Fiji. The
structures of compounds 1 and 2 were determined by spectroscopic methods. Both
compounds contain a unique 2,2-dimethyl-3-hydroxy-7-octynoic acid, which has
previously been described only as a component of kulolide-1 (3) and kulokainalide
1 (4), metabolites from the marine mollusk Philinopsis speciosa. Thus, the
isolation of the yanucamides from this cyanobacterial assemblage supports the
hypothesis that the kulolides and related metabolites are of cyanobacterial
origin.
PMID- 10691709
TI - New quinolizidine alkaloids from Ulex jussiaei.
AB - From an acidic extract of Ulex jussiaei four new quinolizidine alkaloids,
jussiaeiines A (1), B (2), C (3), and D (4), were isolated and characterized by
spectroscopic methods together with (-)-cytisine, (-)-N-methylcytisine, and (-)
anagyrine. The proposed biosynthetic origin of these new alkaloids is briefly
discussed.
PMID- 10691710
TI - New isomalabaricane triterpenes from the marine sponge Stelletta globostellata
that induce morphological changes in rat fibroblasts.
AB - Three new isomalabaricane triterpenes, 29-hydroxystelliferin D (2), 3-epi-29
hydroxystelliferin E (3), and 3-epi-29-hydroxystelliferin A (4), were isolated
from the marine sponge Stelletta globostellata. Their structures, including
absolute stereochemistry, were determined on the basis of spectral data and
chemical methods. Rat fibroblasts treated with 0.2 microM of 2-4 exhibited
unusual morphological characteristics, followed by death in 5 days.
PMID- 10691711
TI - New triterpenoid sulfates from the red alga Tricleocarpa fragilis.
AB - Ten new sulfated terpenoids, including six cycloartenol sulfates (1-6), two 29
nor-cycloartenol sulfates (7,8), and two 29-nor-lanosterol sulfates (9,10), were
isolated from brine shrimp-toxic fractions of the methanolic extract of the red
alga Tricleocarpa fragilis collected in Hawaiian waters. Structures 1-10 were
elucidated by spectral methods, and the absolute stereochemistry for compound 1
at C23 was determined by Mosher analysis. Compounds 7 and 10 showed brine shrimp
toxicity at 50 microg/mL, while 1 and 3 showed substantial activity at 17
microg/mL. Compounds 2, 4, 5, and 9 were inactive. In cytotoxicity assays,
compounds 1-10 were inactive at concentrations tested.
PMID- 10691712
TI - Isolation and biochemical characterization of a new topoisomerase I inhibitor
from Ocotea leucoxylon.
AB - In a continuation of our search for potential tumor inhibitors from plants, we
found that a crude extract from Ocotea leucoxylon showed selective activity
typical of inhibitors of the enzyme topoisomerase I in a yeast assay for DNA
damaging agents. Using a bioassay-directed fractionation approach, the major
bioactive compound was isolated and identified as the known aporphine alkaloid
dicentrinone (4); the inactive alkaloid dicentrine (3) was also isolated.
Compound 4 showed selective bioactivity against the rad52 repair-deficient yeast
strain RS322 (IC(12) 49 microg/mL) and was inactive against the rad52- and topo1
deficient strain RS321 (IC(12) > 2000 microg/mL) and against the repair
proficient strain RJ03 (IC(12) > 2000 microg/mL). Biochemical studies with
recombinant human topoisomerase I indicated that dicentrinone (4) is an inhibitor
of the human enzyme. Colony formation studies suggest that it is weakly
cytotoxic, but that its mechanism of toxicity differs from that of camptothecin
and its derivatives.
PMID- 10691713
TI - Three new diterpenoids based on the novel sarcopetalane skeleton from Croton
sarcopetalus.
AB - The roots of Croton sarcopetalus afforded three new diterpenoids (2-4) with a
novel carbon skeleton that seems to be derived biosynthetically from a pimarane
precursor. The essential oil of the roots gave trans-methylisoeugenol as the main
constituent, along with 22 further compounds.
PMID- 10691714
TI - Grindelane diterpenoids from Stevia subpubescens.
AB - Four new 9R,13R-epoxylabdane diterpenes (1-4) and a known clerodane derivative,
3,4beta-epoxy-5beta,10beta-cis-17alpha, 20alpha-clerod-13(14)-en-15,16-olide,
were isolated from the leaves of Stevia subpubescens. The structures, which
correspond to the grindelane class of diterpenoids, were elucidated by NMR data,
chemical correlation, and single-crystal X-ray diffraction analysis of
monoacetate 5. The absolute configuration of 1-4 is based on the optical activity
of ketone 3 as compared with data of closely related substances.
PMID- 10691715
TI - Ferrocene-based electroactive derivatizing reagents for the rapid selective
screening of alcohols and phenols in natural product mixtures using electrospray
tandem mass spectrometry.
AB - The alcohols and phenols of oil of cloves, lemon oil, rose absolut, and oil of
peppermint were derivatized with ferroceneoyl azide to generate their
ferroceneoyl carbamates. These derivatives are selectively detected at the
attomole level, in nanomolar concentrations by electrospray-tandem mass
spectrometry (ES-MS/MS) without the need for sample cleanup. The ES-MS/MS
analyses of the four essential oils revealed all the expected alcohols, and, in
the case of lemon oil, it detected alpha-terpineol as a trace component that was
not readily observed by GC-MS. The ES-MS/MS analyses complements the more
conventional GC-MS analysis. The ES-MS method has the advantage of speed,
selectivity, and sensitivity over GC-MS for detection of a targeted alcohol of a
specific mass or structural type. The ES-MS method does not require a
chromatographic separation of the components to accomplish its task. In contrast,
GC-MS remains the preferred method for the determination of the total
constituents of an oil. The ES-MS method may produce artifact ions, especially if
the sample is wet and an excess of the ferroceneoyl azide is used; however, the
artifacts did not interfere with the analyses.
PMID- 10691716
TI - Inhibitory effects on HIV-1 protease of constituents from the wood of Xanthoceras
sorbifolia.
AB - From a methanolic extract of the wood of Xanthoceras sorbifolia, two new
compounds, 29-hydroxy-3-oxotirucalla-7,24-dien-21-oic acid (3, xanthocerasic
acid) and epigallocatechin-(4beta-->8, 2beta-->O-7)-epicatechin (6), were
isolated, together with 11 known compounds. Of the isolated compounds, 3
oxotirucalla-7, 24-dien-21-oic acid (2), oleanolic acid (4), and 6 were found to
be inhibitory substances against human immunodeficiency virus (HIV-1) protease,
with their 50% inhibitory concentrations (IC(50)) being 20, 10, and 70 microg/mL,
respectively. Condensed tannins of high molecular weights with epicatechin and
epiafzelechin as the main extender units were found to be the most active
principles of this plant (IC(50) values ca. 6.0 microg/mL).
PMID- 10691717
TI - Artoindonesianin C, a new xanthone derivative from Artocarpus teysmanii.
AB - A new xanthone derivative, artoindonesianin C (1), was isolated from Artocarpus
teysmanii, together with two known prenylated flavonoids, cycloartobiloxanthone
and artonin J. The structure of artoindonesianin C (1) was determined on the
basis of MS and NMR evidence and by comparison with known related compounds.
PMID- 10691718
TI - Efficient synthesis of octandrenolone and related dipyranoacetophenones.
AB - Octandrenolone (1) was prepared in high yield by condensation of 2', 4',6'
trihydroxyacetophenone with 3-chloro-3-methylbut-1-yne in the presence of a
catalytic amount of copper(I) iodide. Methylation of 1 afforded O
methyloctandrenolone (2). Oxidation of 2 with m-chloroperoxybenzoic acid followed
by hydrolysis gave the racemic trans-(+)-1-(9,10-dihydro-9,10-dihydroxy-5-methoxy
2,2,8, 8-tetramethyl-2H,8H-benzo[1,2-b:3,4-b']dipyran-6-yl)ethanone (3), which
confirmed the structure of the natural product previously isolated from Melicope
erromangensis.
PMID- 10691719
TI - Retamatrioside, a new flavonol triglycoside from Retama sphaerocarpa.
AB - A new flavonol triglycoside, retamatrioside (1), has been isolated from the
aerial parts of Retama sphaerocarpa. The structure of 1 has been determined as
rhamnazin 3-O-beta-D-glucopyranosyl-(1-->5)-[beta-D-apiofuranosyl(1-->2)]-al pha
L-arabinofuranoside, using spectroscopic methods.
PMID- 10691720
TI - Triterpenoid saponins from Bongardia chrysogonum.
AB - Two new triterpenoid saponins, 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D
glucopyranosyl-(1-->4)-alph a-L-arabinopyranosyl]-hederagenin (1) and 3-O-[beta-D
glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-alph a-L-arabinopyranosyl]
hederagenin 28-O-[beta-L-glucopyranosyl-(1-->6)-beta-L-glucopyranosyl] ester (2),
together with five known saponins, were isolated from an ethanolic extract of the
tubers of Bongardia chrysogonum. The structures of 1 and 2 were determined on the
basis of spectroscopic studies.
PMID- 10691721
TI - New xenicane diterpenoids from the gorgonian Acalycigorgia inermis.
AB - Acalycixeniolides D-G [corrected] (1-4), four new diterpenoids of the xenicane
class, have been isolated from the gorgonian Acalycigorgia inermis. The
structures of these compounds have been determined by combined spectroscopic
methods. These compounds exhibited cytotoxicity against a human leukemia cell
line.
PMID- 10691722
TI - A new bioactive triene aldehyde from the marine sponge Leucetta microraphis.
AB - A new triene aldehyde, (2E,6Z,9Z)-2-methyl-2,6,9-icosatrienal (1), was isolated
from a MeOH extract of the Okinawan marine sponge Leucetta microraphis. The
structure of 1 was determined by spectroscopic analysis. Three imidazole
alkaloids, leucettamine B, preclathridine A, and (9E)-clathridine 9-N-(2
sulfoethyl)imine, were also obtained and identified. Compound 1 showed moderate
growth-inhibitory activity toward HeLa S3 cells.
PMID- 10691723
TI - 1,9-Dimethylhypoxanthine from a southern Australian marine sponge spongosorites
species.
AB - A Spongosorites sp. collected off southern Australia has yielded 1, 9
dimethylhypoxanthine (4). The structure for 4 was solved by spectroscopic
analysis.
PMID- 10691724
TI - Chemistry of verongida sponges. 10. Secondary metabolite composition of the
caribbean sponge Verongula gigantea.
AB - A detailed analysis of the secondary metabolites of the Caribbean sponge
Verongula gigantea has been performed. A number of bromotyrosine derivatives, 1,
2, and 6-17, were identified, one of which (17) is a novel compound. Its
structure was determined on the basis of spectroscopic evidence. Additionally,
aureol (18) and 5, 6-dibromo-N,N-dimethyltryptamine (19) were isolated from one
of the five analyzed specimens.
PMID- 10691725
TI - Nonpolar components of the latex of Euphorbia peplus.
AB - The less polar fractions of the latex of Euphorbia peplus were found to contain
obtusifoliol, cycloartenol, 24-methylenecycloartanol, lanosterol, and 24
methylenelanosterol in the free and esterified triterpene alcohol fractions; 9
cis-tricosene as the major component of the hydrocarbon fraction; and a new
acyclic triterpene alcohol named peplusol (1). The structure of 1 was determined
as the R-isomer of (all-E)-2-(5,9-dimethyl-1-methylene-4,8-decadienyl)-5,9, 13
trimethyl-4,8,12-tetradecatrien-1-ol by spectral and chemical methods.
PMID- 10691726
TI - Structure and antibacterial activity ofp6 new labdane diterpenoid from Salvia
leriaefolia.
AB - Phytochemical investigation of the choloroform extract of Salvia leriaefolia
afforded 8(17),12E,14-labdatrien-6,19-olide (1), and its structure was determined
by a combination of spectral methods. Compound 1 was found to possess
antibacterial activity against Staphylococcus aureus.
PMID- 10691727
TI - Polyhalogenated monoterpenes from a tasmanian collection of the red seaweed
Plocamium cartilagineum.
AB - Two new polyhalogenated monoterpenes (3E, 7E)-8-bromo-(2E)-chloromethylene-(5R,
6R)-dichloro-6-methyloctadien-1-al (1) and (1Z,3E,7E)-8,9-dibromo-(1Z,5R*, 6R*,9)
tetrachloro-6-methyloctatriene [corrected] (2), together with two known compounds
(3 and 4), were isolated and identified from the red alga Plocamium cartilagineum
collected along the eastern coast of Tasmania. The structures were established by
spectroscopic techniques.
PMID- 10691728
TI - Cernuosides A and B, two sucrase inhibitors from Pulsatilla cernua.
AB - Two oleanane-type oligoglycosides, cernuosides A (1) and B (2), were isolated
from the roots of Pulsatilla cernua (Ranunculaceae). Structure elucidation was
accomplished by 1D and 2D NMR (DQF-COSY, TOCSY, HMQC, HMBC, and ROESY) methods,
FABMS, and hydrolysis. Both compounds showed moderate activity against sucrase.
PMID- 10691729
TI - Dolastatin 3 and two novel cyclic peptides from a palauan collection of Lyngbya
majuscula.
AB - A collection of Lyngbya majuscula from Palau contained the peptides dolastatin 3
(1), homodolastatin 3 (2), and kororamide (3), together with aplysiatoxin (4),
debromoaplysiatoxin (5), and oscillatoxin A (6). The structures of the new
peptides homodolastatin 3 (2) and kororamide (3) were determined by
interpretation of spectroscopic data and chemical degradation.
PMID- 10691730
TI - Isolation of the pharmacologically active saponin ginsenoside Rb1 from ginseng by
immunoaffinity column chromatography.
AB - Immunoaffinity column chromatography using an anti-ginsenoside Rb1 monoclonal
antibody has made possible a single-step separation of ginsenoside Rb1 from a
crude extract of ginseng roots (Panax ginseng). The combination of immunoaffinity
column chromatography and an enzyme-linked immunosorbent assay (ELISA) was also
investigated.
PMID- 10691731
TI - Loss of PTEN facilitates HIF-1-mediated gene expression.
AB - In glioblastoma-derived cell lines, PTEN does not significantly alter apoptotic
sensitivity or cause complete inhibition of DNA synthesis. However, in these cell
lines PTEN regulates hypoxia- and IGF-1-induced angiogenic gene expression by
regulating Akt activation of HIF-1 activity. Restoration of wild-type PTEN to
glioblastoma cell lines lacking functional PTEN ablates hypoxia and IGF-1
induction of HIF-1-regulated genes. In addition, Akt activation leads to HIF
1alpha stabilization, whereas PTEN attenuates hypoxia-mediated HIF-1alpha
stabilization. We propose that loss of PTEN during malignant progression
contributes to tumor expansion through the deregulation of Akt activity and HIF-1
regulated gene expression.
PMID- 10691732
TI - ATR disruption leads to chromosomal fragmentation and early embryonic lethality.
AB - Although a small decrease in survival and increase in tumor incidence was
observed in ATR(+/-) mice, ATR(-/-) embryos die early in development, subsequent
to the blastocyst stage and prior to 7.5 days p.c. In culture, ATR(-/-)
blastocysts cells continue to cycle into mitosis for 2 days but subsequently fail
to expand and die of caspase-dependent apoptosis. Importantly, caspase
independent chromosome breaks are observed in ATR(-/-) cells prior to widespread
apoptosis, implying that apoptosis is caused by a loss of genomic integrity.
These data show that ATR is essential for early embryonic development and must
function in processes other than regulation of p53.
PMID- 10691734
TI - Translation by ribosome shunting on adenovirus and hsp70 mRNAs facilitated by
complementarity to 18S rRNA.
AB - Translation initiation on eukaryotic mRNAs involves 40S ribosome association with
mRNA caps (m(7)GpppN), mediated by initiation factor eIF4F. 40S eukaryotic
ribosomes and initiation factors undergo 5' scanning to the initiation codon,
with no known role for complementarity between eukaryotic 18S rRNA and the 5'
noncoding region of mRNAs. We demonstrate that the 5' noncoding region of human
adenovirus late mRNAs, known as the tripartite leader, utilizes a striking
complementarity to 18S rRNA to facilitate a novel form of translation initiation
referred to as ribosome shunting, in which 40S ribosomes bind the cap and bypass
large segments of the mRNA to reach the initiation codon. Related elements are
also shown to promote ribosome shunting in adenovirus IVa2 intermediate phase
mRNA during virus infection and in human heat shock protein 70 (hsp70) mRNA for
selective translation during heat shock. The importance of mRNA complementarity
to 18S rRNA suggests that ribosome shunting may involve either specific RNA
structural features or a prokaryotic-like interaction between mRNA and rRNA.
PMID- 10691733
TI - The carboxyl terminus of vertebrate poly(A) polymerase interacts with U2AF 65 to
couple 3'-end processing and splicing.
AB - Although it has been established that the processing factors involved in pre-mRNA
splicing and 3'-end formation can influence each other positively, the molecular
basis of this coupling interaction was not known. Stimulation of pre-mRNA
splicing by an adjacent cis-linked cleavage and polyadenylation site in HeLa cell
nuclear extract is shown to occur at an early step in splicing, the binding of
U2AF 65 to the pyrimidine tract of the intron 3' splice site. The carboxyl
terminus of poly(A) polymerase (PAP) previously has been implicated indirectly in
the coupling process. We demonstrate that a fusion protein containing the 20
carboxy-terminal amino acids of PAP, when tethered downstream of an intron,
increases splicing efficiency and, like the entire 3'-end formation machinery,
stimulates U2AF 65 binding to the intron. The carboxy-terminal domain of PAP
makes a direct and specific interaction with residues 17-47 of U2AF 65,
implicating this interaction in the coupling of splicing and 3'-end formation.
PMID- 10691735
TI - The p23 molecular chaperones act at a late step in intracellular receptor action
to differentially affect ligand efficacies.
AB - Multiple molecular chaperones, including Hsp90 and p23, interact with members of
the intracellular receptor (IR) family. To investigate p23 function, we compared
the effects of three p23 proteins on IR activities, yeast p23 (sba1p) and the two
human p23 homologs, p23 and tsp23. We found that Sba1p was indistinguishable from
human p23 in assays of seven IR activities in both animal cells and in yeast; in
contrast, certain effects of tsp23 were specific to that homolog. Transcriptional
activation by two IRs was increased by expression of any of the p23 species,
whereas activation by five other IRs was decreased by Sba1p or p23, and
unaffected by tsp23. p23 was expressed in all tissues examined except striated
and cardiac muscle, whereas tsp23 accumulated in a complementary pattern; hence,
p23 proteins might contribute to tissue-specific differences in IR activities.
Unlike Hsp90, which acts on IR aporeceptors to stimulate ligand potency (i.e.,
hormone-binding affinity), p23 proteins acted on IR holoreceptors to alter ligand
efficiencies (i.e., transcriptional activation activity). Moreover, the p23
effects developed slowly, requiring prolonged exposure to hormone. In vitro, p23
interacted preferentially with hormone-receptor-response element ternary
complexes, and stimulated receptor-DNA dissociation. The dissociation was
reversed by addition of a fragment of the GRIP1 coactivator, suggesting that the
two reactions may be in competition in vivo. Our findings suggest that p23
functions at one or more late steps in IR-mediated signal transduction, perhaps
including receptor recycling and/or reversal of the response.
PMID- 10691736
TI - Homeodomain and winged-helix transcription factors recruit activated Smads to
distinct promoter elements via a common Smad interaction motif.
AB - We have investigated the regulation of the activin-inducible distal element (DE)
of the Xenopus goosecoid promoter. The results show that paired-like homeodomain
transcription factors of the Mix family, Mixer and Milk, but not Mix.1, mediate
activin/TGF-beta-induced transcription through the DE by interacting with the
effector domain of Smad2, thereby recruiting active Smad2/Smad4 complexes to the
Mixer/Milk-binding site. We identify a short motif in the carboxyl termini of
Mixer and Milk, which is demonstrated to be both necessary and sufficient for
interaction with the effector domain of Smad2 and is required for mediating
activin/TGF-beta-induced transcription. This motif is not confined to these
homeodomain proteins, but is also present in the Smad2-interacting winged-helix
proteins Xenopus Fast-1, human Fast-1, and mouse Fast-2. We demonstrate directly
that transcription factors of different DNA-binding specificity recruit activated
Smads to distinct promoter elements via a common mechanism. These observations,
together with the temporal and spatial expression patterns of Mixer and Milk,
lead us to propose a model for mesoendoderm formation in Xenopus in which these
homeodomain transcription factor/Smad complexes play a role in initiating and
maintaining transcription of target genes in response to endogenous activin-like
signals.
PMID- 10691737
TI - Yeast heterochromatin is a dynamic structure that requires silencers
continuously.
AB - Transcriptional silencing of the HM loci in yeast requires cis-acting elements,
termed silencers, that function during S-phase passage to establish the silent
state. To study the role of the regulatory elements in maintenance of repression,
site-specific recombination was used to uncouple preassembled silent chromatin
fragments from silencers. DNA rings excised from HMR were initially silent but
ultimately reactivated, even in G(1)- or G(2)/M-arrested cells. In contrast, DNA
rings bearing HML-derived sequence were stably repressed due to the presence of a
protosilencing element. These data show that silencers (or protosilencers) are
required continuously for maintenance of silent chromatin. Reactivation of
unstably repressed rings was blocked by overexpression of silencing proteins
Sir3p and Sir4p, and chromatin immunoprecipitation studies showed that
overexpressed Sir3p was incorporated into silent chromatin. Importantly, the
protein was incorporated even when expressed outside of S phase, during G(1)
arrest. That silencing factors can associate with and stabilize preassembled
silent chromatin in non-S-phase cells demonstrates that heterochromatin in yeast
is dynamic.
PMID- 10691738
TI - Mammalian hepatocyte differentiation requires the transcription factor HNF
4alpha.
AB - HNF-4alpha is a transcription factor of the nuclear hormone receptor family that
is expressed in the hepatic diverticulum at the onset of liver development. Mouse
embryos lacking HNF-4alpha fail to complete gastrulation due to dysfunction of
the visceral endoderm. This early embryonic lethality has so far prevented any
analyses of the contribution of HNF-4alpha toward liver development and
hepatocyte differentiation. However, we have shown that complementation of HNF
4alpha(-/-) embryos with a tetraploid embryo-derived wild-type visceral endoderm
rescues this early developmental arrest and allows HNF-4alpha(-/-) embryos to
proceed normally through midgestation stages of development. Examination of these
rescued embryos revealed that HNF-4alpha was dispensable for specification and
early development of the liver. However, HNF-4alpha(-/-) fetal livers failed to
express a large array of genes whose expression in differentiated hepatocytes is
essential for a functional hepatic parenchyma, including genes encoding several
apolipoproteins, metabolic proteins, and serum factors. In addition, we have
demonstrated that HNF-4alpha is essential for expression of the transcription
factors HNF-1alpha and PXR within the fetal liver. We therefore conclude that HNF
4alpha is both essential for hepatocyte differentiation during mammalian liver
development and also crucial for metabolic regulation and liver function.
PMID- 10691739
TI - A Kruppel-like zinc finger protein is involved in nitrogen-fixing root nodule
organogenesis.
AB - Mechanisms regulating plant host differentiation of the nitrogen-fixing root
nodules remain mostly unknown. Sinorhizobium meliloti induces this process in
Medicago sativa in which the Mszpt2-1 gene is expressed in vascular bundles of
roots and nodules. This gene codes for a Kruppel-like zinc finger protein, a
class of transcription factors involved in many animal developmental processes.
Expression of Mszpt2-1 in yeast cells conferred osmotic tolerance. Antisense
plants grew normally but developed nonfunctional nodules, in which
differentiation of the nitrogen-fixing zone and bacterial invasion were arrested.
Hence, a vascular bundle-associated Kruppel-like gene is required for the
formation of the central nitrogen-fixing zone of the root nodule.
PMID- 10691740
TI - The stringent response in Myxococcus xanthus is regulated by SocE and the CsgA C
signaling protein.
AB - Myxococcus xanthus fruiting body development is induced by amino acid limitation.
The decision to grow or develop is established by the RelA-dependent stringent
response and A-signaling. We identified two new members of this regulatory
hierarchy, socE and the C-signaling gene csgA. SocE depletion arrests growth and
induces sporulation under conditions that normally favor growth as well as
curtailing DNA and stable RNA synthesis, inhibiting cell elongation, and inducing
accumulations of the stringent nucleotides ppGpp and pppGpp [(p)ppGpp]. This
system separates C-signaling, which does not occur under these conditions, from
CsgA enzyme activity. Amino acid substitutions in the CsgA coenzyme binding
pocket or catalytic site eliminate growth arrest. relA mutation also eliminates
growth arrest. Eleven pseudorevertants selected for growth following SocE
depletion contained mutations in csgA or relA. These results suggest that CsgA
induces the stringent response and while SocE inhibits it. Unlike the csgA
mutant, wild-type and socE csgA cells maintained high levels of (p)ppGpp
throughout development. We suggest that CsgA maintains growth arrest throughout
development to divert carbon from A-signaling and other sources into
developmental macromolecular synthesis.
PMID- 10691742
TI - A hard road: finding ways to reduce teen tobacco use.
PMID- 10691741
TI - Progression of meiotic DNA replication is modulated by interchromosomal
interaction proteins, negatively by Spo11p and positively by Rec8p.
AB - Spo11p is a key mediator of interhomolog interactions during meiosis. Deletion of
the SPO11 gene decreases the length of S phase by approximately 25%. Rec8p is a
key coordinator of meiotic interhomolog and intersister interactions. Deletion of
the REC8 gene increases S-phase length, by approximately 10% in wild-type and
approximately 30% in a spo11Delta background. Thus, the progression of DNA
replication is modulated by interchromosomal interaction proteins. The spo11
Y135F DSB (double strand break) catalysis-defective mutant is normal for S-phase
modulation and DSB-independent homolog pairing but is defective for later events,
formation of DSBs, and synaptonemal complexes. Thus, earlier and later functions
of Spo11 are defined. We propose that meiotic S-phase progression is linked
directly to development of specific chromosomal features required for meiotic
interhomolog interactions and that this feedback process is built upon a more
fundamental mechanism, common to all cell types, by which S-phase progression is
coupled to development of nascent intersister connections and/or related aspects
of chromosome morphogenesis. Roles for Rec8 and/or Spo11 in progression through
other stages of meiosis are also revealed.
PMID- 10691743
TI - From social taboo to "torch of freedom": the marketing of cigarettes to women.
PMID- 10691744
TI - Asia: choppy seas for BAT butt boat.
PMID- 10691745
TI - India: movie shoots at women.
PMID- 10691747
TI - Australia: philip morris exploits SIDS research
PMID- 10691746
TI - Czech Republic: Gauloises dates for students.
PMID- 10691748
TI - Litigation: a tobacco lawyer's view
PMID- 10691749
TI - South africa: one life, waste it!
PMID- 10691751
TI - UK: no cigarette under the stiff upper lip
PMID- 10691752
TI - Holy smoke!
PMID- 10691750
TI - It's true. It kills. It's great!
PMID- 10691753
TI - Hong kong: down at the fair.
PMID- 10691754
TI - Smoke signs: patterns of tobacco billboard advertising in a metropolitan region.
AB - OBJECTIVE: To use geographic information systems data and analyses to describe
locations and characteristics of tobacco billboards in a large metropolitan area,
and to assess the extent to which tobacco companies are locating billboards in
close proximity to minority neighbourhoods and schools. DESIGN: Observational
study of billboards in a large metropolitan region. SETTING: City and county of
St Louis, Missouri. PARTICIPANTS: All stationary billboards in the city and
county of St Louis were eligible to be observed, with the exception of bus stop
and street side retail advertising signs (for example, cigarette advertising at
gas stations). A total of 1239 non-blank billboards were observed. All data were
collected in early 1998. MAIN OUTCOME MEASURES: Tobacco and non-tobacco billboard
geographic distribution; billboard type and product brand frequencies; and
billboard neighbourhood characteristics. RESULTS: Almost 20% of the billboards
contained tobacco advertising. Four of the top five and nine of the top 22 brands
displayed on billboards were tobacco products. Billboards were located in all
areas of St Louis except for the communities with the highest average incomes.
Tobacco billboards were more likely to be found in low income areas and areas
with a higher percentage of African Americans. Images of African American figures
on tobacco billboards were concentrated in the most heavily African American
populated regions of the city. Approximately 74% of all billboards in the city of
St Louis were within 2000 feet (700 metres) of public school property.
CONCLUSIONS: Tobacco products were the single most heavily advertised type of
product on billboards in St Louis. The geographic distribution of tobacco
billboards, as well as the types of images found on these billboards, is
consistent with the hypothesis that tobacco companies are targeting poor and
minority communities with their advertising. Methods employing geographic
information systems are a powerful technique for examining outdoor tobacco
advertising.
PMID- 10691755
TI - A randomised controlled trial of a community intervention to prevent adolescent
tobacco use.
AB - OBJECTIVE: Experimental evaluation of comprehensive community wide programme to
prevent adolescent tobacco use. DESIGN: Eight pairs of small Oregon communities
(population 1700 to 13 500) were randomly assigned to receive a school based
prevention programme or the school based programme plus a community programme.
Effects were assessed through five annual surveys (time 1-5) of seventh and ninth
grade (ages 12-15 years) students. INTERVENTION: The community programme
included: (a) media advocacy, (b) youth anti-tobacco activities, (c) family
communications about tobacco use, and (d) reduction of youth access to tobacco.
MAIN OUTCOME MEASURE: The prevalence of self reported smoking and smokeless
tobacco use in the week before assessment. RESULTS: The community programme had
significant effects on the prevalence of weekly cigarette use at times 2 and 5
and the effect approached significance at time 4. An effect on the slope of
prevalence across time points was evident only when time 2 data points were
eliminated from the analysis. The intervention affected the prevalence of
smokeless tobacco among grade 9 boys at time 2. There were also significant
effects on the slope of alcohol use among ninth graders and the quadratic slope
of marijuana for all students. CONCLUSION: The results suggest that comprehensive
community wide interventions can improve on the preventive effect of school based
tobacco prevention programmes and that effective tobacco prevention may prevent
other substance use.
PMID- 10691756
TI - Competence skills help deter smoking among inner city adolescents.
AB - OBJECTIVE: To test whether higher levels of general competence are linked to more
frequent use of refusal assertiveness that is in turn related to less subsequent
smoking among inner city adolescents. METHODS: Longitudinal study conducted
during three year middle school or junior high school period. A sample of 1459
students attending 22 middle (ages 11-14 years) and junior high (ages 12-15
years) schools in New York City participated. Students completed surveys at
baseline, one year follow up, and two year follow up. The students self reported
smoking, decision making skills, personal efficacy, and refusal assertiveness.
Teams of three to five data collectors administered the questionnaire following a
standardised protocol. These data were collected in school during a regular 40
minute class period. RESULTS: Based on the tested structural equation model,
decision making and personal efficacy (that is, general competence) predicted
higher refusal assertiveness and this greater assertiveness predicted less
smoking at the two year follow up. The tested model had a good fit and was
parsimonious and consistent with theory. CONCLUSIONS: Adolescent smoking
prevention programmes often teach refusal skills in order to help youth resist
peer pressure to smoke. The present findings suggest that teaching general
competence skills as well may help to reduce smoking because youth with better
personal efficacy and decision making skills are better able to implement smoking
refusal strategies.
PMID- 10691757
TI - Effect of an eight week smoking ban on women at US navy recruit training command.
AB - OBJECTIVE: To examine the effect of a unique organisational smoking ban on female
United States Navy recruits, a population with historically high smoking rates.
SETTING AND DESIGN: Study participants were female recruits (n = 5503) entering
the Navy recruit training command between March 1996 and March 1997 (12
consecutive months). Participants completed smoking surveys at entry to recruit
training (baseline) and again at graduation from training after exposure to an
eight week, 24 hour a day smoking ban. Effects of the ban on baseline to
graduation changes in perceptions of being a smoker were examined, and relapse
rates among baseline ever smokers was assessed three months after leaving recruit
training. RESULTS: Among all recruits, 41.4% reported being smokers at entry
(that is, reported any smoking in the 30 days before entering recruit training).
As a result of the ban, there was a significant reduction (from about 41% to 25%,
p < 0.001) in the percentage of all women recruits who reported themselves as
smokers, a much larger change than expected had no ban been in place. Relapse at
the three month follow up varied according to the type of smoker at entry into
the Navy, with rates ranging from 89% relapse among baseline daily smokers to 31%
among baseline experimenters. CONCLUSIONS: Findings suggest that the ban provides
some smokers who desire to quit with an external impetus and support to do so.
However, high relapse rates indicate that more than an organisationally mandated
smoking ban during recruit training is needed to help younger smokers, more
regular smokers, and those who intend to continue smoking to quit after joining
the Navy.
PMID- 10691759
TI - Exposure of black youths to cigarette advertising in magazines.
AB - OBJECTIVE: To estimate the potential exposure of black adolescents to brand
specific advertising in magazines. DESIGN: A probit regression analysis was
conducted of pooled 1990 and 1994 data on brand specific advertising in 36
popular US magazines to examine the relationship between the presence or absence
of advertising in each magazine for each of 12 cigarette brands, and the
proportion of each magazine's youth (ages 12-17 years) readers who were black.
MAIN OUTCOME MEASURES: The presence or absence of advertising in each magazine in
1990 and 1994, for each of 12 cigarette brands. RESULTS: After controlling for
total magazine readership and the percentage of young adult, Hispanic, and female
readers, black youth cigarette brands (those whose market share among black
youths exceeded their overall market share) were more likely than other brands to
advertise in magazines with a higher percentage of black youth readers. Holding
all other variables constant at their sample means, the probability of a non
black youth brand advertising in a magazine decreased over the observed range of
percentage black youth readership from 0.65 (95% confidence interval (CI) 0.55 to
0.75) for magazines with 5% black youth readers to 0.33 (95% CI 0.00 to 0.69) for
magazines with 91% black youth readers. In contrast, the probability of a black
youth brand advertising in a magazine increased from 0.40 (95% CI 0.17 to 0.62)
at 5% black youth readership to 1.00 (95% CI 0.97 to 1.00) at 91% black youth
readership. CONCLUSIONS: Black youths are more likely than white youths to be
exposed to magazine advertising by cigarette brands popular among black
adolescents.
PMID- 10691758
TI - Investing in youth tobacco control: a review of smoking prevention and control
strategies.
AB - OBJECTIVE: To provide a comprehensive review of interventions and policies aimed
at reducing youth cigarette smoking in the United States, including strategies
that have undergone evaluation and emerging innovations that have not yet been
assessed for efficacy. DATA SOURCES: Medline literature searches, books, reports,
electronic list servers, and interviews with tobacco control advocates. DATA
SYNTHESIS: Interventions and policy approaches that have been assessed or
evaluated were categorised using a typology with seven categories (school based,
community interventions, mass media/public education, advertising restrictions,
youth access restrictions, tobacco excise taxes, and direct restrictions on
smoking). Novel and largely untested interventions were described using nine
categories. CONCLUSIONS: Youth smoking prevention and control efforts have had
mixed results. However, this review suggests a number of prevention strategies
that are promising, especially if conducted in a coordinated way to take
advantage of potential synergies across interventions. Several types of
strategies warrant additional attention and evaluation, including aggressive
media campaigns, teen smoking cessation programmes, social environment changes,
community interventions, and increasing cigarette prices. A significant
proportion of the resources obtained from the recent settlement between 46 US
states and the tobacco industry should be devoted to expanding, improving and
evaluating "youth centred" tobacco prevention and control activities.
PMID- 10691760
TI - Case study of attempts to enact self service tobacco display ordinances: a tale
of three communities.
AB - OBJECTIVE: To examine self service tobacco displays (SSTDs) and youth retail
tobacco access by comparing longitudinal illegal tobacco sales rates in three
communities in Santa Barbara County, California, that considered or implemented
ordinances banning SSTDs. A confirmatory survey was also conducted to
substantiate the longitudinal data. DESIGN: A longitudinal case study design was
utilised. Five undercover tobacco buys were conducted between 1994 and 1997 (n =
332). In addition, one confirmatory survey was conducted in a geographically
separated area, which had no ordinances banning SSTDs (n = 57). RESULTS:
Decreases in youth buy rates were reported in all three communities. Most
notably, the first city to enact a SSTD ban, Carpinteria, achieved a 0% sales
rate, which was maintained throughout the study period. In contrast, Santa
Barbara and Goleta experienced considerable drops in their illegal sales rates,
but neither community obtained results as dramatic as those found in Carpinteria.
The confirmatory survey showed that 32.1% of stores with SSTDs sold cigarettes to
minors; this compares to a sales rate of 3.4% in stores without SSTDs (chi(2) (1)
= 8.11, p = 0.004). CONCLUSIONS: Efforts to enact self service bans are likely to
meet with retail and tobacco industry opposition, as was the case in this study's
three communities. The process of community debate, resultant publicity
surrounding the issue, and enactment of SSTD ordinances may serve to not only
increase merchant awareness of youth tobacco laws and their penalties but also
may contribute to reduced youth cigarette sales rates. Implications and
limitations of the findings are discussed.
PMID- 10691761
TI - The economics of tobacco: myths and realities.
PMID- 10691762
TI - Reflections on the saga of tar content: why did we measure the wrong thing?
PMID- 10691763
TI - Banning smoking outdoors is seldom ethically justifiable.
PMID- 10691764
TI - Banning outdoor smoking is scientifically justifiable.
PMID- 10691765
TI - Outdoor smoking bans: more than meets the eye.
PMID- 10691766
TI - How I nearly became a Marlboro man.
PMID- 10691767
TI - Abreast of the West: German effort to distract poles from the truth about
smoking.
PMID- 10691769
TI - Tobacco and women's health
PMID- 10691768
TI - Only naughty the first time.
PMID- 10691771
TI - Smoke and mirrors: a history of denial
PMID- 10691770
TI - Double indemnity: making sense of the US settlement
PMID- 10691772
TI - Up from the ashes: the fight for a new tobacco Act
PMID- 10691774
TI - Introduction to the Fourth Acta Physiologica Scandinavica International Symposium
on vasodilators in the development of hypertension: NO and dopamine.
PMID- 10691773
TI - Catecholamine biosynthesis and physiological regulation in neuroendocrine cells.
AB - The catecholamines are widely distributed in mammals and their levels and
physiological functions are regulated at many sites. These include their release
from neuroendocrine cells, the type and sensitivity of the multiple receptors in
target cells, the efficacy of the reuptake system in the secretory cells, and the
rates of catecholamine biosynthesis and degradation. In the present review the
main focus will be on the more recent studies on the biosynthesis in
neuroendocrine cells which involves a specific set of enzymes, with special
reference to physiologically important regulatory mechanisms. Eight enzymes of
the biosynthetic pathway have now been identified, cloned, expressed as
recombinant proteins, characterized with respect to catalytic and regulatory
properties, and some of them also crystallized. The identification of the
tyrosine hydroxylase catalysed reaction as the rate-limiting step in the normal
catecholamine biosynthesis has attracted most attention, both in terms of
transcriptional and post-translational regulation. In certain human genetic
disorders of catecholamine biosynthesis other enzymes in the pathway may become
rate-limiting, notably those involved in the biosynthesis/regeneration of the
natural co-factor tetrahydrobiopterin in the tyrosine hydroxylase reaction. The
enzymes involved seem to be regulated by a variety of physiological factors, both
on a long-term scale and a short-term basis, and include the relative rates of
synthesis, degradation and state of activation of the biosynthetic enzymes,
notably of tyrosine hydroxylase. Multiple surface receptors and signalling
pathways are activated in response to extracellular stimuli and play an essential
role in the regulation of catecholamine biosynthesis.
PMID- 10691775
TI - Biological effects of arginine metabolites.
AB - Arginine and its metabolites exert physiological effects on the vasculature and
on the kidney and also provide important influences on the regulation of cell
proliferation. We summarize the known information regarding two major metabolites
of arginine: (a) nitric oxide (NO) and (b) agmatine, decarboxylated arginine.
Both agents appear to interact in producing vasodilation and increases in
glomerular filtration rate (GFR) in the kidney. There is evidence for inter
regulation of arginine pathways in the sense that agmatine is capable of
inhibiting inducible nitric oxide synthase (iNOS), the inflammatory NOS isoform.
Both NO and agmatine influence cell proliferation via effects on polyamine
synthesis. In addition, both NO and agmatine exert inhibitory effects on
ornithine decarboxylase (ODC) and the putrescine transporter by significantly
different mechanisms. Therefore, arginine and arginine metabolites exert both
vascular regulatory functions and impact on the regulation of cell proliferation.
Significant inter-regulation among arginine pathways occurs within the three
metabolic major pathways within the cell: (1) nitric oxide synthase (2) arginase
and ornithine decarboxylase, and (3) arginine decarboxylase.
PMID- 10691776
TI - Protein-protein interactions controlling nitric oxide synthases.
AB - Nitric oxide (NO) biosynthesis is tightly regulated by a variety of mechanisms
ranging from transcriptional to post-translational controls. Calmodulin has long
been known to be an allosteric modulator of the three major NO synthases (NOS).
Recent studies indicate that other proteins directly associate with NOS isoforms
and regulate their activity or spatial distribution in the cell. Several proteins
residing in or recruited to plasmalemmal caveolae of endothelial cells serve as
allosteric regulators of endothelial NOS (eNOS). Caveolins, the resident
scaffolding proteins of caveolae, and calmodulin undergo reciprocal Ca2+
dependent association and dissociation with eNOS in the caveolar membrane that
inhibits (caveolins) and activates (calmodulin) eNOS activity. Other caveolar
proteins appear to contribute to the eNOS-membrane complex, including the
bradykinin B2 receptor, the angiotensin AT1 receptor, the CAT1 arginine
transporter, and Hsp90. Direct interactions of a variety of proteins bearing PDZ
domains with the PDZ domain of neuronal NOS (nNOS) have been shown to influence
the subcellular distribution and/or activity of the enzyme in brain and muscle.
One of these proteins, PSD-93, co-localizes with a subpopulation of nNOS in the
macula densa. Although considerable emphasis has been placed on transcription as
the principal step of regulation for inducible NOS (iNOS), our laboratory has
recently defined a regulatory interaction of iNOS with Rho family GTPases. While
the role of protein-eNOS interactions in the control of vascular tone has been
increasingly clarified, the interactions and regulatory importance of protein
association with nNOS and iNOS in the vasculature and kidney remains to be
explored.
PMID- 10691777
TI - A pivotal role of nitric oxide in endothelial cell dysfunction.
AB - The functional role of the vascular endothelium is a subject of growing interest
and appreciation. Some of the key functions of the endothelium are modulated by
the activity and expression of endothelial nitric oxide synthase (eNOS),
suggesting a role for this enzyme in endothelial dysfunction. Several well-known
angiogenic stimulators exert their effect only in the presence of the functional
eNOS. In this setting NO production is responsible for the scalar podokinetic
cell motility, which is a prerequisite for the acquisition of vectorial movement
when guidance cues are applied. The mode of this NO action appears to lie in the
accelerated turnover of focal adhesions through the process of
activation/inactivation of protein tyrosine phosphatases. Localization of eNOS to
the caveolar domains, in the proximity of clustered beta1 integrins, provides an
additional level of regulatory complexity through the modulation of caveolar
dynamics and the state of caveolin oligomerization. Therefore, eNOS serves
various important functions in the endothelium and is a putative target for
therapeutic interventions.
PMID- 10691778
TI - Mode of nitric oxide action on the renal vasculature.
AB - Our study aimed to characterize the essential cellular pathways along which
nitric oxide (NO) exerts its well-known vasodilatatory properties in the kidney.
Using the isolated perfused rat kidney model we examined the roles of potassium
channels, cGMP-protein kinase activity and cAMP-phosphodiesterases (PDE) in the
effect of NO on renovascular resistance. We found that neither potassium channel
activity nor G-kinase activity was essential for the vasodilatatory effect of NO.
The effect of NO, however, was essentially mimicked by pharmacological inhibition
of PDE-3, which is a cGMP-inhibitable PDE. As PDE-3 is strongly expressed in
renal preglomerular vessels and NO stimulates cGMP formation in renal vessels, it
appears likely that inhibition of cAMP degradation and consequently the cAMP
pathway are crucially involved in mediating the effects of NO on renal vascular
resistance.
PMID- 10691779
TI - Interactions of the renin-angiotensin system and neuronal nitric oxide synthase
in regulation of cyclooxygenase-2 in the macula densa.
AB - Cyclooxygenase-2 (COX-2) expression in rat kidney is localized to the macula
densa and the immediately proximal cTALH and increases after salt restriction.
Either ACE inhibitors or AT1 receptor blockers increase COX-2 expression in both
control and salt-restricted animals, suggesting that the RAS activation feedback
inhibits renal cortical COX-2 expression. To determine whether increased COX-2
expression in response to ACE inhibition mediated increases in renin production,
rats were treated with Captopril for 1 week with or without the specific COX-2
inhibitor, SC58236. Plasma renin activity increased significantly in the
Captopril group. This increase was partially reversed by simultaneous treatment
with SC58236. Kidney renin activity also increased in the Captopril group
compared with control, which was also significantly inhibited by SC58236
treatment. Because of the localization of bNOS to MD and surrounding cTALH, the
current study investigated the role of NO in the regulation of COX-2 expression.
Rats were fed a normal diet, low salt diet or low salt diet combined with
captopril and half of them were treated with the neuronal NOS inhibitor, 7-NI,
and half with vehicle. After 7 days, mRNA was extracted and the microsome
proteins purified from renal cortex. COX-2 mRNA expression was measured by
Northern-blot and normalized with GAPDH. 7-NI treatment decreased COX-2 mRNA and
immunoreactive COX-2 expression in each group. In summary, these studies indicate
that COX-2 from macula densa/cTALH is a regulator of renin production and
release. Angiotensin II may be a negative regulator of cTALH/macula densa COX-2
expression, and NO may mediate increased renal cortical COX-2 expression seen in
volume depletion. These studies suggest important interactions between the NO and
COX-2 systems in the regulation of arteriolar tone and the renin-angiotensin
system by the macula densa.
PMID- 10691780
TI - The autoinhibitory control element and calmodulin conspire to provide
physiological modulation of endothelial and neuronal nitric oxide synthase
activity.
AB - NO production by the endothelial and neuronal isoforms of nitric oxide synthase
(cNOS) is regulated on a moment-to-moment basis by calmodulin binding, triggered
by transient elevations in intracellular-free calcium levels. Nonetheless,
additional modes of cNOS regulation are implicit in the discoveries of stimuli
that elicit a sustained increase in cNOS activity despite undetectable or
transient increases in intracellular Ca2+ in endothelial cells; such stimuli
include shear-stress, oestrogen, insulin or insulin-like growth factor treatment
of endothelial cells. Recently, we identified a peptide insertion within the FMN
binding domain of mammalian NOSs that is unique to calcium-dependent isoforms,
and not shared with inducible NOS or ancestral flavoproteins. Evidence suggests
that this insertion serves as a fundamental control element, analogous to
intrinsic autoinhibitory peptides that have been demonstrated to regulate
activity of other calmodulin-dependent enzymes. Thus, the peptide insertion of
cNOSs appears to function as structural element that is displaced upon calmodulin
binding, resulting in dysinhibition of NO synthesis. Once displaced, the peptide
may also be subject to transient chemical modifications and protein-protein
interactions that modulate autoinhibitory function. Herein we summarize our
present knowledge and speculate on mechanisms by which calmodulin and the
autoinhibitory peptide conspire to regulate cNOS activity.
PMID- 10691781
TI - Nitric oxide: a physiological mediator of the type 2 (AT2) angiotensin receptor.
AB - Virtually all of the biological actions of angiotensin II (ANG II) have been
thought to be mediated by the type 1 (AT1) angiotensin receptor and the function
of the type 2 (AT2) receptor is unknown. We now describe a novel physiological
action of ANG II to release nitric oxide (NO) mediated by the AT2 receptor in
both the kidney and gastrointestinal tract. We present an integrated model for a
counter-regulatory protective action of the AT2 receptor mediated by nitric
oxide. In the kidney, ANG II at the AT2 receptor stimulates a vasodilator cascade
of bradykinin (BK), NO and cyclic GMP which is tonically activated only during
conditions of increased ANG II, such as sodium depletion. In the absence of the
AT2 receptor, pressor and antinatriuretic hypersensitivity to ANG II is
associated with BK and NO deficiency. In angiotensin-dependent hypertension, the
hypotensive effect at AT1 receptor blockade is due at least in part to AT2
receptor stimulation and consequent increased activity of the vasodilator
cascade. In the gastrointestinal tract, physiological quantities of ANG II
stimulate the AT2 receptor releasing NO and cGMP leading to increased sodium and
water absorption. In conclusion, NO is an important physiological mediator of ANG
II at the AT2 receptor.
PMID- 10691782
TI - Intracellular localization of dimethylarginine dimethylaminohydrolase
overexpressed in an endothelial cell line.
AB - Methylarginines are endogenous inhibitors of nitric oxide synthase (NOS) and have
been implicated in the regulation of the nitric oxide pathway in health and
disease. Cellular concentrations of free methylarginines are determined in part
by the activity of dimethylarginine dimethylaminohydrolase (DDAH). There are two
isoforms of DDAH which have distinct tissue distributions with some relationship
to NOS isoforms. We have determined the intracellular localization of both DDAH
isoforms by overexpression of epitope-tagged DDAH in an immortalized endothelial
cell line. Immunofluorescence confocal microscopy and immunoblotting indicate
that both isoforms are predominantly cytosolic with no specific association with
organelles or the plasma membrane. These data suggest that the key role for DDAH
may be to ensure that under normal conditions the levels of methylarginines are
kept low throughout the whole cell.
PMID- 10691783
TI - Phosphorylation and activation of the endothelial nitric oxide synthase by fluid
shear stress.
AB - Fluid shear stress activates the endothelial nitric oxide (NO) synthase (eNOS) by
a mechanism which does not require an increase in the intracellular concentration
of free Ca2+ ([Ca2+]i), and is sensitive to several kinase inhibitors. Although
phosphorylation of eNOS has been suggested to regulate enzyme activity, the
mechanism of eNOS activation is still unclear. Here we demonstrate that fluid
shear stress elicits the phosphorylation of eNOS on tyrosine and serine residues.
Inhibition of phosphatidylinositol 3-kinase (PI3K), using wortmannin or a
dominant negative mutant of its downstream target, Akt (protein kinase B),
prevented the maintained serine phosphorylation and activation of eNOS. Enhancing
eNOS phosphorylation by inhibiting serine/threonine phosphatases, increased eNOS
activity by approximately twofold, as assessed by the accumulation of
intracellular cyclic GMP, without increasing the intracellular concentration of
free Ca2+. These data suggest that shear stress activates a pathway involving
PI3K and the serine/threonine kinase Akt, which phosphorylates eNOS. This
phosphorylation directly increases eNOS activity at resting [Ca2+]i, thus
rendering the shear stress-induced activation of eNOS apparently Ca2+
independent.
PMID- 10691785
TI - Exocytosis and endocytosis in juxtaglomerular cells.
AB - The cellular events related to secretion of renin are not well understood. Here
we review some of the evidence that has led to the current understanding of renin
secretion as a process that involves exocytosis as the predominant mode of
secretion. This is based on the observation of occasional fusion events between
secretory granules and cell membrane and measurement of intermittent secretion of
renin from single afferent arterioles, with a renin content of each secretion
episode that corresponds to the renin content of one secretory granule. More
recently it has been demonstrated that the afferent arterioles lose a large
number of renin granules after acute stimulation without changing the average
granular volume. Current electrophysiological techniques have now permitted
direct measurements of cell membrane capacitance in juxtaglomerular (JG) cells as
a measure of net addition (exocytosis) or removal (endocytosis) of membrane
material. With this technique we have shown that cAMP, which is a vasodilator and
stimulates renin secretion, enhances net exocytosis at low concentrations, while
at higher concentrations membrane retrieval processes are also stimulated. We
suggest that both exocytosis and endocytosis are regulated processes in the JG
cells and both may be important for the long-term control of renin secretion at
the single cell level.
PMID- 10691784
TI - Impaired effect by NO synthase inhibition on tubuloglomerular feedback in rats
after chronic renal denervation.
AB - Acute unilateral renal denervation (aDNX) is associated with reduced
tubuloglomerular feedback (TGF) sensitivity. Six days after denervation (cDNX)
TGF sensitivity is somewhat restored, but TGF reactivity increased. This study
aimed to investigate if the increased TGF reactivity that was seen in cDNX
kidneys was owing to reduced production of nitric oxide (NO). TGF characteristics
were determined with micropuncture experiments in anaesthetized rats, using the
stop-flow pressure (PSF) technique. Maximal drop in PSF (DeltaPSF) was used as an
index of TGF reactivity and the loop of Henle perfusion rate that elicited half
maximal DeltaPSF, the turning point (TP) was used as a measure of TGF
sensitivity. In cDNX kidneys, TP was higher than in control rats (25.4 +/- 1.5 nL
min-1 vs. 19.1 +/- 1.1 nL min-1), but clearly lower than in aDNX rats (37. 3 +/-
3.1 nL min-1). TGF was more reactive in cDNX rats (DeltaPSF=14. 7 +/- 1.1 mmHg)
than in aDNX (7.9 +/- 1.1 mmHg) and control rats (9. 6 +/- 0.9 mmHg).
Intratubular inhibition of NO synthase N omega-nitro-L-arginine (L-NA) in sham
DNX animals, decreased TP to 13.9 +/- 2.2 nL min-1 and DeltaPSF was increased
with 92%. In cDNX kidneys TP was not significantly reduced by L-NA, and TGF
reactivity was only moderately increased by 31%. Intratubular infusion of L
arginine (L-Arg) reduced DeltaPSF from 10.2 +/- 0.7 to 6.5 +/- 0.6 mmHg in sham
DNX kidneys, but TP was unaffected. In cDNX kidneys, there was no effect on
either DeltaPSF or TP by the addition of L-Arg. However, when NO was delivered
via sodium nitroprusside in the tubular perfusate, a clear reduction of DeltaPSF
was seen in both sham-DNX and cDNX kidneys (from 9.9 +/- 0.5 to 4.4 +/- 1.0 and
from14.9 +/- 1.3 to 8.1 +/- 1.5 mmHg, respectively). This indicates that cDNX is
a state of low renal NO production and that this low level of NO resets TGF to a
higher sensitivity and more pronounced reactivity.
PMID- 10691786
TI - Advanced glycosylation end-products and NO-dependent vasodilation in renal
afferent arterioles from diabetic rats.
AB - Systemic pressor responses to acetylcholine (ACh) are reduced in DM, an effect
thought to be related to quenching of nitric oxide (NO) by advanced glycosylation
end-products (AGE). We studied the effects of AGE in juxtamedullary (JM) afferent
arterioles (AA) from rats with 40-50 days diabetes mellitus (DM) induced via
streptozotocin. JM AA were perfused in vitro with solutions containing fresh RBCs
suspended in either 6% bovine albumin or 6% AGE-albumin in euglycaemic Krebs
Ringer. Autoregulatory responses were evident in the DM vessels: AA constricted
31 +/- 2% (n=9) when perfusion pressure (PP) was raised from 60 to 140 mmHg. ACh
(10 microM) caused a 43 +/- 15% dilation and Ca2+-channel blockade elicited a 95
+/- 14% dilation at 100 mmHg PP, indicating substantial basal vascular tone in DM
AA. L-NAME (0.1 mM) constricted DM AA by 21 +/- 2% (n=9) at 100 mmHg PP,
indicating significant basal NO production in DM vessels. Segments of renal
resistance arteries from DM rats perfused in vitro responded to muscarinic
stimulation and elevated glucose levels with significant increments in NO
production, as measured with an NO-sensitive electrode. This observation shows
that the renal endothelial NO system is intact in DM. While AGE in the perfusate
dilated control AA, they had no effect on DM AA at all PP levels, although they
blunted ACh-induced dilation. Hence, although AGE do appear to have vasoactive
properties in the absence of hyperglycaemia, the results of this study are
inconsistent with substantial NO quenching by AGE.
PMID- 10691787
TI - Endogenous nitric oxide and epoxyeicosatrienoic acids modulate angiotensin II
induced constriction in the rabbit afferent arteriole.
AB - Nitric oxide (NO) and epoxyeicosatrienoic acids (EETs), cytochrome P450
epoxygenase metabolites of arachidonic acid, are released by the vascular
endothelium and play important roles in the control of glomerular haemodynamics.
We examined whether endogenous NO or EETs modulate angiotensin II- (AngII)
induced constriction in isolated microperfused afferent arteriole (Af-Art) of the
rabbit kidney. When Af-Arts were treated with NG-nitro-L-arginine methyl ester (L
NAME, an inhibitor of NO synthese; 10-4 mol L-1) or miconazole (an inhibitor of
P450 epoxygenase; 10-6 mol L-1), basal diameter was decreased by 34.5 +/- 2.2 and
13.9 +/- 3.2%, respectively. AngII added to both the bath and lumen decreased the
diameter of Af-Arts in a dose-dependent manner. Pretreatment with either L-NAME
or miconazole also augmented the constrictor response to AngII. AngII at 10-8 mol
L-1 decreased the diameter to 39.2 +/- 1.4, 32.9 +/- 3.6, and 12.7 +/- 4.6%, in
control, L-NAME-, and miconazole-treated group, respectively. In order to study
whether the AngII type2 (AT2) receptor modulates AngII action via NO or EETs, we
repeated the experiments in the presence of PD123319 (an AT2 receptor antagonist;
10-7 mol L-1). In the presence of PD123319, L-NAME still augmented the
constrictor response to AngII, however, miconazole had no effect. In the presence
of PD123319, AngII at 10-8 mol L-1 decreased the diameter to 25.0 +/- 4.6, 9.4 +/
4.0, and 26.0 +/- 3.3%, in control, L-NAME-, and miconazole-treated group,
respectively. These results suggest that (1) tonic release of NO and EETs
attenuates the vasoconstrictor response to AngII in Af-Arts and (2) AT2 receptor
seems to be coupled to EETs rather than the NO pathway.
PMID- 10691788
TI - Chronic increases in transmural pressure reduce NO-mediated dilations in isolated
resistance arteries of the hamster.
AB - It is unclear whether the impairment of NO-mediated dilation in hypertension is
the cause or the consequence of high blood pressure. We therefore studied in
isolated resistance arteries whether elevated transmural pressure affects NO
mediated dilation. Arteries (n=5-7) were perfused at hydrostatic pressures of
either 45, 120 or 160 mmHg for 48 h. Subsequently, diameter and calcium responses
(fura 2) were studied at a transmural pressure of 45 mmHg. Pre-exposure to 120
and 160 mmHg reduced resting diameters and minimal diameters after stimulation
with noradrenaline and significantly increased corresponding intracellular free
calcium levels in vascular smooth muscle. Moreover, the NO-mediated dilation in
response to acetylcholine was significantly reduced although the increase in
endothelial calcium was not altered. Dilations induced by the NO donor SNP were
not affected. It is concluded that chronically elevated pressure per se impairs
endothelial NO production by a mechanism distal to receptor-dependent calcium
increases.
PMID- 10691789
TI - Interaction between nitric oxide and oxygen radicals in regulation of
tubuloglomerular feedback.
AB - NADPH oxidase, nitric oxide synthase (NOS) and cyclooxygenase are oxidases that
are expressed in the juxtaglomerular apparatus (JGA) or blood vessels and can
generate oxygen radicals (O-2) during partial reduction of molecular oxygen. O-2
interacts rapidly and irreversibly with nitric oxide (NO) to yield peroxynitrite
(ONOO-), thereby restricting the half-life, diffusion distance and bioactivity of
NO in tissues. NO generated by a neuronal (n) NOS isoform that is heavily
expressed in macula densa (MD) cells, is generated during NaCl reabsorption at
the MD and blunts the expression of the tubuloglomerular feedback (TGF) response.
Therefore, we tested the hypothesis that O-2 formed in the JGA of the normal rat
limits NO signalling. Tempol is a membrane-permeable superoxide dismutase (SOD)
mimetic. Maximal TGF responses were assessed from the fall in proximal stop flow
pressure during orthograde perfusion of artificial tubular fluid (ATF) into the
loop of Henle. Microperfusion of tempol (10-4 M) into the efferent arteriole (EA)
of Wistar-Kyoto rats blunted maximal TGF response (8. 2 +/- 0.4 vs. 6.4 +/- 0.4
mmHg; n=8; P < 0.05). Graded doses of the NO donor compound, S-nitroso
acetylpenicillamine (SNAP; 10-7-10-4 M) microperfused into the lumen of the MD
produces graded buffering of TGF. During EA microperfusion of tempol, responses
to luminal SNAP at 10-6 M and greater were enhanced significantly (P < 0.05 or
<0. 01). In conclusion, O-2 generated in the JGA can be metabolized by a membrane
permeable SOD mimetic. O-2 enhances the basal TGF response and limits NO
signalling from the macula densa. Therefore, O-2 and NO interact in the JGA to
modulate the TGF response.
PMID- 10691790
TI - Concerted actions of renal endothelial and macula densa NO systems in the
maintenance of extracellular fluid volume.
AB - It is now clear that nitric oxide (NO) exerts a substantial influence on renal
function and that the kidney has a high capacity to produce NO. However, there
are at least two different NO systems in the kidney. The interplay between NO
generated by the endothelium and by the macula densa is considered in this
review. It seems that endothelial NO increases in response to an increase in
perfusion pressure and an increase in distal delivery, whereas macula densa NO
decreases upon a sustained increase in distal delivery. Furthermore, evidence is
accumulating that macula densa NO may well mediate renin release. Though
seemingly in contrast, both the response of the endothelial NO and of the macula
densa NO system seem appropriate to restore a perturbation of fluid balance. The
function of the tubuloglomerular feedback (TGF) mechanism is likely to be
influenced by both sources of NO, because of the close proximity of these NO
producing cells to the vascular smooth muscle cells of the afferent arteriole.
The endothelial NO system seems to be responsible for short-term, dampening
actions to increased afferent arteriolar tone elicited by activation of the TGF
system. The macula densa NO system, on the other hand, is probably adapting TGF
responses to sustained increases in distal delivery. The analysis presented in
this paper is an attempt to integrate the function of the two NO systems into
physiological regulation. The exact role of the medullary NOS enzymes remains to
be further elucidated.
PMID- 10691791
TI - Nitric oxide and preglomerular vascular lesions in lyon spontaneously
hypertensive rats.
AB - Accumulation of Sudan black-stainable (SB+) lipids is a hallmark of the focal
inflammato-proliferative lesions that develop along preglomerular vessels in N G
nitro-L-arginine methyl ester (L-NAME) and angiotensin II hypertensive rats. We
extended our findings to genetically hypertensive Lyon (LH) rats aged 14 and 30
weeks and to age-matched normotensive (LN) rats. Vessels were isolated by HCl
maceration. Despite high systolic blood pressure (SBP), hypercholesterolaemia,
albuminuria and increased interlobular and afferent arteriolar media thickness,
SB+ lesions were rarely found in LH rats, regardless of age. To probe nitric
oxide as a potential source of vascular protection, 14-week-old LN and LH rats
received L-NAME for 10 days (20 mg kg-1 day-1, per os), which increased SBP to
174 +/- 5 and to >200 mmHg, respectively. It induced formation of focal SB+
lesions less frequently in LN than LH rats, in which they affected 39 +/- 7, 44
+/- 5 and 15 +/- 5% of arcuate arterial branches, interlobular arteries and
afferent arterioles, respectively. Immunoreactive endothelin-1 was found to
accumulate at the level of SB+ lesions. Co-administered with L-NAME, hydralazine
(15 mg kg-1 day-1, per os) limited SBP rise to approximately 10 mmHg in both LN
and LH rats. As a result, SB+ lesions were rare in LN rats, but were frequent in
LH rats. In conclusion, preglomerular SB+ lesions are spontaneously lacking in LH
rats. Endogenous nitric oxide production provides protection against vascular
barotrauma. Endothelin-1 likely plays an autocrine/paracrine role in vascular
lesion formation.
PMID- 10691792
TI - Nitric oxide-angiotensin II interactions in angiotensin II-dependent
hypertension.
AB - Many studies indicate that renal haemodynamic function in angiotensin II- (ANG
II) dependent hypertension is not reduced as much as would be predicted from the
elevated ANG II levels suggesting that counteracting renoprotective mechanisms
are activated. One important renoprotective effect is mediated by increased
levels of nitric oxide. Recent studies using the ANG II-infused hypertensive rat
model have shown that inhibition of nitric oxide synthesis (NOS) causes greater
decreases in renal blood flow and glomerular filtration rate in ANG II-infused
hypertensive rats than in control rats. This augmented nitric oxide-dependent
influence is localized primarily in the cortex and to the preglomerular
vasculature. The differential effects on the renal cortex and medulla are also
reflected by the differences in NOS activities and protein expression. Ca2+
dependent NOS activity was significantly greater in the cortex but not the
medulla of the ANG II-infused hypertensive rats compared with control rats. This
was associated with marked activation of endothelial NOS protein levels and
smaller increases in neuronal NOS protein levels in the cortex but not in the
medulla. In contrast, the Ca2+-independent NOS activity and the inducible NOS
protein levels in the cortex were significantly lower in the ANG II-infused
hypertensive rats. These data support the hypothesis that cortical Ca2+-dependent
NOS, primarily endothelial NOS, is stimulated during the early phases of ANG II
induced hypertension and exerts a renoprotective effect on cortical
haemodynamics.
PMID- 10691793
TI - Control of arterial blood pressure and renal sodium excretion by nitric oxide
synthase in the renal medulla.
AB - Work in our laboratory has focused on the role of nitric oxide synthase (NOS) in
the regulation of renal medullary function. Biochemical studies demonstrated that
the renal medulla is enriched in immunoreactive NOS protein and NOS enzymatic
activity when compared with the renal cortex. Further experiments showed large
amounts of NOS activity in the inner medullary collecting ducts, while moderate
NOS activity was found in glomeruli and vasa recta and minimal NOS activity was
detected in other nephron segments examined. In subsequent functional studies,
selective renal medullary infusion of NOS stimulators (bradykinin or
acetylcholine) or inhibitors (L-NAME) preferentially altered medullary blood
flow. The alterations in medullary flow were associated with parallel changes in
sodium and water excretion. Similar to the effects observed in anaesthetized
rats, chronic infusion of L-NAME directly into the renal medullary interstitial
space of conscious, uninephrectomized SD rats selectively decreased renal
medullary blood flow throughout a 5-day L-NAME infusion period. The decrease in
medullary blood flow was associated with retention of sodium and the development
of hypertension, and the effects were reversible. In contrast to the effects of
chronic NOS inhibition, renal medullary infusion of NOS substrate L-arginine
prevented the development of sodium-sensitive hypertension in the Dahl salt
sensitive rat placed on a high sodium diet. The data reviewed in this paper
indicate that NOS isoforms expressed in the renal medulla have a potent influence
on renal medullary tubular and vascular function with consequential effects on
fluid and electrolyte homeostasis and arterial blood pressure.
PMID- 10691794
TI - Blood pressure control in eNOS knock-out mice: comparison with other species
under NO blockade.
AB - Changes in arterial blood pressure (ABP) lead to changes in vascular shear
stress. This mechanical stimulus increases cytosolic Ca2+ in endothelial cells,
which in turn activates the endothelial isoform of the nitric oxide synthase. The
subsequently formed NO reaches the adjacent vascular smooth muscle cells, where
it reduces vascular resistance in order to maintain ABP at its initial level.
Thus, NO may play an important role as a physiological blood pressure buffer.
Previous data on the importance of eNOS for blood pressure control are reviewed
with special emphasis on the fact that endogenous nitric oxide can buffer blood
pressure variability (BPV) in dogs, rats and mice. In previous studies where all
isoforms of the nitric oxide synthase were blocked pharmacologically, increases
in blood pressure and variability were observed. Thus, we set out to clarify
which isoform of the nitric oxide synthase is responsible for this BPV
controlling effect. Hence, blood pressure control was studied in knock-out mice
lacking specifically the gene for endothelial nitric oxide synthase with their
respective wild-type controls. One day after surgery, under resting conditions,
blood pressure was increased by 47 mmHg (P < 0.05), heart rate was lower (-77
beats min-1, P < 0.05), and BPV doubled (P < 0.05). Based on these results, we
conclude that chronic blood pressure levels are influenced by eNOS and that there
is a blood pressure buffering effect of endogenous nitric oxide which is mediated
by the endothelial isoform of the nitric oxide synthase.
PMID- 10691795
TI - Abnormal pressure-natriuresis in hypertension: role of nitric oxide.
AB - The kidneys have a critical role in long-term control of arterial pressure by
regulating extracellular fluid and plasma volume. According to the renal body
fluid feedback mechanism for long-term control, persistent hypertension can only
occur as a result of a reduction in renal sodium excretory function or a
hypertensive shift in the pressure-natriuresis relationship. Although an abnormal
relationship between renal perfusion pressure and renal sodium excretion has been
identified in every type of hypertension where it has been sought, factors
responsible for this effect are still unclear. Nitric oxide (NO) is produced
within the kidney and plays an important role in the control of many intrarenal
processes which regulate the renal response to changes in perfusion pressure and
thus, help determine plasma volume and blood pressure. Numerous studies have
shown that long-term inhibition of NO synthesis results in a chronic rightward
shift and marked attenuation in renal pressure-natriuresis. Recent studies have
shown that certain animal models of genetic hypertension and forms of human
hypertension areas are associated with a decrease in NO synthesis. Reductions in
NO synthesis reduces renal sodium excretory function not only through direct
actions on the renal vasculature, but through modulation of other vasoconstrictor
processes and through direct and indirect alterations in tubular sodium
transport. The causes and consequences of the dysregulation of NO in hypertension
and other renal disease processes remain an important area of investigation.
PMID- 10691796
TI - Renal NO production and the development of hypertension.
AB - The juxtaglomerular apparatus (JGA) has the very important functions of detecting
the fluid flow rate to the distal tubule and thus controlling the glomerular
filtration rate (GFR) (tubuloglomerular feedback mechanism [TGF]) and renin
release from the afferent arteriole. In studies of the TGF it has been evident
that the sensitivity of this mechanism can be reset. Volume expansion will reset
it to a low sensitivity leading to a high GFR and urine excretion rate, while
dehydration will sensitize the TGF mechanism, giving rise to a low GFR and low
urine excretion rate. Furthermore, we have found that in animals that
spontaneously develop hypertension there is initially a sensitization of the TGF,
leading to a reduced GFR and urine excretion rate, with fluid volume retention in
the body and a consequent rise in blood pressure. When the pressure is raised,
the TGF characteristics are normalized. In the macula densa (MD) cells in the
JGA, there is a large production of NO from neuronal NOS. This production
continuously reduces TGF sensitivity and is apparently impaired in animals that
spontaneously develop hypertension. When we added an nNOS inhibitor to the
drinking water for several weeks while measuring blood pressure, we found an
increase in blood pressure after 3-4 weeks of treatment. This effect was
abolished by a high salt diet. From these investigations, it also appeared as if
nNOS-derived NO inhibited renin release. Experiments have also indicated that NO
may resensitize inhibited G-protein coupled purinergic receptors.
PMID- 10691797
TI - Plasma from ESRD patients inhibits nitric oxide synthase activity in cultured
human and bovine endothelial cells.
AB - Our recent observations of reduced total nitric oxide synthesis in renal failure
patients on peritoneal dialysis and haemodialysis suggest that hypertension in
end-stage renal disease involves lack of vasodilatory endothelial NO. To directly
test this, uraemic plasma was obtained from dialysis patients and incubated with
cultured vascular endothelial cells, to determine the effect on nitric oxide
synthase (NOS) activity in comparison with plasma from subjects with normal renal
function. After incubation for 6 h with 20% uraemic plasma from peritoneal
dialysis and immediately prehaemodialysis patients, NOS activity was reduced in
human dermal microvascular endothelial cells. Haemodialysis did not remove the
NOS-inhibitory activity of uraemic plasma nor did it activate inducible NOS, as
NOS activity was always similar in control and dexamethasone pretreated cells.
Nitric oxide production (accumulation of nitrite and nitrate) was lower in cells
incubated with uraemic vs. normal plasma and excess arginine increased nitric
oxide production by cells previously exposed to uraemic medium. This inhibitory
effect was not associated with co-factor deficiency but did correlate with plasma
concentrations of endogenous NOS inhibitors. These in vitro findings suggest that
low endothelial NOS activity may contribute to hypertension in end stage renal
disease patients.
PMID- 10691798
TI - Role of nitric oxide in haemodialysis hypotension.
AB - To investigate the possible involvement of nitric oxide (NO) in haemodialysis
hypotension, we measured plasma concentrations of nitrate anion (NO3-), a
metabolite of NO, in 114 patients undergoing maintenance haemodialysis. Mean
plasma NO3- concentrations before dialysis were greater in subjects with lower
blood pressure (155 +/- 16 micromol L-1) than in those with middle (117 +/- 8
micromol L-1) or higher blood pressure (105 +/- 12 micromol L-1) before dialysis.
Further, mean plasma NO3- concentrations before dialysis were greater in subjects
with lower blood pressure (186 +/- 13 micromol L-1) than in those with middle
(112 +/- 7 micromol L-1) or higher blood pressure (64 +/- 11 micromol L-1) after
dialysis. Plasma NO3- concentrations before dialysis were inversely correlated
with mean blood pressure before dialysis (r=0.318, P=0.0006), and showed a strong
inverse correlation with mean blood pressure after dialysis (r=0.608, P=0.0001).
In the selected participants who had equal range of mean blood pressure before
dialysis, mean plasma NO3- concentrations were greater in subjects with severe
hypotension during dialysis (180 +/- 14 micromol L-1) than in those with mild
hypotension (99 +/- 11 micromol L-1) or without hypotension (53 +/- 12 micromol L
1); plasma NO3- concentrations before dialysis were inversely correlated with
changes in mean blood pressure during dialysis and mean blood pressure after
dialysis. Results indicate that enhanced NO production may be involved in acute
hypotension during dialysis, and suggest the possible involvement of NO in the
pathogenesis of chronic hypotension associated with maintenance haemodialysis.
PMID- 10691799
TI - Genetic mechanisms underlying the regulation of urinary sodium excretion and
arterial blood pressure: the role of adducin.
PMID- 10691800
TI - Differentiation of vasoactive renal sympathetic nerve fibres.
AB - Activation of renal sympathetic nerves produces marked changes in renal
haemodynamics, tubular ion and water transport and renin secretion. This review
examines information indicating that these effects are mediated by functionally
specific groups of renal sympathetic nerve fibres separately innervating the
renal vessels, tubules and juxtaglomerular granular cells.
PMID- 10691801
TI - Vasoconstrictor responses in thromboxane receptor knockout mice: tubuloglomerular
feedback and ureteral obstruction.
AB - The role of thromboxane (TP) in the vasoconstriction induced by tubuloglomerular
feedback or 18-h ureteral obstruction was studied in wild type mice (TP +/+), and
in heterozygous (TP +/-) and homozygous TP receptor knockout mice (TPR -/-). TGF
function was assessed from the response of stop flow pressure (PSF) to a maximum
increase in loop of Henle flow rate (0-30 nL min-1). PSF fell by 6.4 +/- 0.4 mmHg
in wild-type mice, by 6.1 +/- 0.6 mmHg in TP +/-, and by 7.9 +/- 0.7 mmHg in TP
/- mice. In the presence of the TP receptor agonist U46,619 (10-5 M) the PSF
reduction increased to 10. 4 +/- 0.8 mmHg in TP +/+, and to 10.6 +/- 2.8 mmHg in
TP +/-, but was unchanged at 7.7 +/- 0.7 mmHg in TP -/-. Mean arterial blood
pressures were comparable between groups (103 +/- 3 mmHg in TP +/+, 113 +/- 4.6
in TP +/- and 113 +/- 2.4 mmHg in TP -/- mice). Intratubular pressure following
unilateral ureteral obstruction was significantly higher in TP -/- than in TP +/+
mice both in the early phase (0-3 h) and late phase (18 h) of obstruction. These
results indicate that chronic TP receptor deficiency does not significantly alter
maximum TGF responses in mice, and that it is accompanied by exaggerated
vasodilatation during short-term unilateral ureteral obstruction and attenuated
vasoconstriction during longer lasting obstruction. We conclude that thromboxane
is primarily a regulator of renal vascular tone under pathophysiological
conditions.
PMID- 10691802
TI - Renal sodium/calcium exchange; a vasodilator that is defective in salt-sensitive
hypertension.
AB - The Na+ : Ca2+ exchanger is an important plasma membrane ion transport pathway
that plays a major role in controlling [Ca2+]i. In smooth muscle cells, it may
function as a Ca2+ extrusion pathway and may help lower [Ca2+]i in response to
vasoconstrictor-induced increases in [Ca2+]i. It may also extrude [Ca2+]i and
lead to vasodilation in response to vasodilators. Our recent studies have been
performed to determine the existence and regulation of the Na+ : Ca2+ exchanger
in renal contractile cells which include afferent and efferent arterioles and
mesangial cells. Exchanger activity is present in all three of these contractile
elements but is higher in afferent arterioles vs. efferent arterioles. We have
also examined the role of altered regulation of the exchanger in the SHR and in
salt-sensitive hypertension. With the establishment of high blood pressure, Na+ :
Ca2+ exchanger activity is reduced in afferent but not in efferent arterioles in
both models of hypertension. Other works in cultured mesangial cells and freshly
dissected afferent arterioles, have shown that protein kinase C (PKC) up
regulates the Na+ : Ca2+ exchanger from Dahl/Rapp salt-resistant rats while it
fails to do so in arterioles and mesangial cells from salt-sensitive rats. This
defect in PKC regulation of Na+ : Ca2+ exchange is the result of a loss of PKC
mediated translocation of the exchanger to the plasma membrane in S mesangial
cells. Thus, a defect in the PKC-Na+ : Ca2+ exchanger-translocation pathway may
cause dysregulation of [Ca2+]i and help explain the dramatic decrease in GFR that
occurs in this model of hypertension.
PMID- 10691803
TI - Intrarenal dopamine coordinates the effect of antinatriuretic and natriuretic
factors.
AB - The precision by which sodium balance is regulated suggests an intricate
interaction between modulatory factors released from intra- and extrarenal
sources. Intrarenally produced dopamine has a central role in this interactive
network. Dopamine, produced in renal tubular cells acts as an autocrine and
paracrine factor to inhibit the activity of Na+,K+-ATPase as well as of a number
of sodium influx pathways. The natriuretic effect of dopamine is most prominent
under high salt diet. The antinatriuretic effects of noradrenaline, acting on
alpha-adrenoceptors and angiotensin II are opposed by dopamine as well as by
atrial natriuretic peptide (ANP). Several lines of evidence have suggested that
ANP acts via the renal dopamine system and recent studies from our laboratory
have shown that this effect is attributed to recruitment of silent D1 receptors
from the interior of the cell towards the plasma membrane. Taken together, the
observations suggest that dopamine coordinates the effects of antinatriuretic and
natriuretic factors and indicate that an intact renal dopamine system is of major
importance for the maintenance of sodium homeostasis and normal blood pressure.
PMID- 10691804
TI - Dopamine D(3) receptors in the rat kidney: role in physiology and
pathophysiology.
AB - It is well accepted that dopamine receptors play an important role in the
regulation of cardiovascular and kidney function. Most of the knowledge on the
renal actions of dopamine has been accumulated focussing on the prototypes of the
two known dopamine receptor subfamilies, i.e. D1 and D2. The dopamine D3 receptor
is a member of the D2-like subfamily and has been intensively studied in the
neurosciences. Recently, the peripheral actions of this receptor subtype have
also raised considerable interest as well because its effects on kidney function
appear to be different from that of the other dopamine receptors. This short
overview will summarize the data reported and add new results on the role of D3
receptors in the regulation of renal function as well as their potential
pathophysiological implications.
PMID- 10691805
TI - Effect of salt intake on jejunal dopamine, Na+,K+-ATPase activity and electrolyte
transport.
AB - The present study addresses the question of the relevance of salt intake on
jejunal dopamine, Na+,K+-ATPase activity and electrolyte transport. Low salt, but
not high salt, intake for 2 weeks increased dopamine levels in the jejunal mucosa
accompanied by a marked decrease in L-3,4-dihydroxyphenylalanine tissue levels.
By contrast, in rats fasted for 72 h the effect of refeeding for 24 h with a low
salt diet failed to change dopamine tissue levels, although it significantly
increased those of L-3,4-dihydroxyphenylalanine. By contrast, high salt intake
markedly increased the tissue levels of both dopamine and L-3,4
dihydroxyphenylalanine, without changes in dopamine/L-3,4-dihydroxyphenylalanine
tissue ratios. Tissue levels of both L-3,4-dihydroxyphenylalanine and dopamine in
control conditions (normal salt intake for 2 weeks) were markedly higher (P <
0.05) than in rats submitted to 72 h fasting plus 24 h refeeding. The effect of
fasting for 72 h followed by 24 h refeeding was a marked decrease in jejunal
Na+,K+-ATPase activity, particularly evident for rats fed a normal salt and high
salt diets during the refeeding period. Basal short circuit current was similar
in rats fed a normal salt diet for 2 weeks and 24 h, and the type of diet failed
to alter basal short circuit current after refeeding with normal, low and high
salt diets. On the other hand, the effect of prolonged low salt intake was a
marked decrease in jejunal Na+, K+-ATPase activity and basal short circuit
current, whereas high salt intake failed to alter enzyme activity and basal short
circuit current. In rats fed for 2 weeks a high salt diet ouabain was found to be
more potent in reducing jejunal short circuit current than in rats fed normal and
low salt diets. The effect of furosemide was more marked in rats fed for 2 weeks
high and low salt diets than in animals receiving a normal salt intake. Dopamine
(up to 1 micromol L-1) was found not to alter Na+,K+-ATPase and basal short
circuit current in jejunal epithelial sheets, in rats fed with normal, low and
high salt diets for 2 weeks and 24 h.
PMID- 10691806
TI - Chemical hypoxia-induced increases in dopamine D1A receptor mRNA in renal
epithelial cells are mediated by nitric oxide.
AB - Nitric oxide (NO) and dopamine (DA) have similar effects on renal function, with
both having natriuretic and diuretic effects mediated by vascular and tubular
mechanisms. Renal ischaemia or hypoxia have been shown to influence the activity
of both systems. However, it is not known whether there is any crosstalk between
the NO and dopaminergic systems in the kidney. Here using the porcine proximal
tubule-like renal epithelial LLC-PK1 cell line as a model system, we determined
whether exposure of cells to chemical hypoxia altered the steady-state levels of
D1A receptor mRNA and whether the changes involved the NO system. Exposure of LLC
PK1 cells to chemical hypoxia resulted in a marked increase in D1A receptor mRNA
levels as measured by reverse transcription-polymerase chain reaction (RT-PCR).
The increased levels of D1A receptor mRNA following hypoxia were blocked by the
NO synthase inhibitors NG-nitro-L-arginine methylester (L-NAME) or NG-monomethyl
L-arginine (L-NMMA). Further evidence that the NO system exerted positive effects
on D1A receptor gene expression came from finding that the NO donor sodium
nitroprusside, the NO precursor L-arginine and the guanosine 3', 5'-cyclic
monophosphate (cyclic GMP) analogue 8-Br-cGMP all increased D1A receptor mRNA
levels in LLC-PK1 cells. These results indicate that expression of the D1A
receptor in LLC-PK1 cells can be positively regulated by the NO system. Such an
interaction between the renal NO and DA systems may contribute to the reported
protective effects that NO and DA exert upon the kidney under conditions of
ischaemia.
PMID- 10691807
TI - The collecting duct, dopamine and vasopressin-dependent hypertension.
AB - AVP not only increases osmotic water permeability (Pf) in the rat cortical
collecting duct (CCD), but also acts synergistically with aldosterone to augment
sodium reabsorption (JNa). These effects are inhibited by catecholamines via
alpha2 adrenergic receptors, and by dopamine. We review here studies designed to
determine the mechanism and receptor involved in dopamine action. The inhibitory
effect of dopamine on Na+ and water transport was found to be reversible, and was
not produced by agonists specific to D1A and D1B receptors. D2-type (D2, D3 or
D4) receptors and activation of the GTP-binding protein Gi were implicated by the
observation that dopamine had no inhibitory effect when JNa and Pf were
stimulated by a cyclic AMP analogue plus isobutylmethylxanthine. The only
dopaminergic antagonist that reversed the inhibitory effect of dopamine was
clozapine, which is relatively D4-specific. We also found that dopamine or D1
specific agonists by themselves had no effect on cAMP production. However,
dopamine inhibited the high rate of AVP-dependent cAMP production, and this
effect of dopamine was reversed by clozapine but not other antagonists or by
inhibitors of protein kinase C. The D4 receptor was observed in western blots of
renal cortical proteins, and it was localized to the collecting duct by RT-PCR
and immuno-histochemistry using a D4-specific antibody. These results show that
at least a portion of the natriuretic effect of dopamine can be attributed to
inhibition of AVP-dependent Na+ reabsorption by the CCD, and they introduce
another signalling system as a candidate in the aetiology of low-renin, salt
dependent hypertension.
PMID- 10691808
TI - D1 dopamine receptor signalling defect in spontaneous hypertension.
AB - Dopamine modulates cardiovascular function by actions in the central and
peripheral nervous system, by altering the secretion/release of prolactin, pro
opiomelanocortin, vasopressin, aldosterone, and renin, and by directly affecting
renal function. Dopamine produced by the renal proximal tubule exerts an
autocrine/paracrine action via two classes of dopamine receptors, D1-like (D1 and
D5) and D2-like (D2, D3, and D4), that are differentially expressed along the
nephron. The autocrine/paracrine function of dopamine, manifested by tubular
rather than by haemodynamic mechanisms, becomes most evident during extracellular
fluid volume expansion. This renal autocrine/paracrine function is lost in
essential hypertension and in some animal models of genetic hypertension. The
molecular basis for the dopaminergic dysfunction in hypertension may involve an
abnormal post-translational modification of dopamine receptors.
PMID- 10691809
TI - Defective renal dopamine D1-like receptor signal transduction in obese
hypertensive rats.
AB - It is reported that dopamine promotes renal sodium excretion via activation of D1
like dopamine receptors located on the proximal tubules. In spontaneously
hypertensive rats the natriuretic and diuretic response to exogenously
administered and endogenously produced dopamine is reduced, which results from a
diminished dopamine-induced inhibition of the enzyme, Na+,K+-ATPase. The present
study was designed to examine dopamine-receptor mediated inhibition of Na+,K+
ATPase and its associated signal transduction pathway in the proximal tubules of
Zucker obese and lean control rats. The obese animals were hypertensive,
hyperinsulinaemic and hyperglycaemic compared with the lean rats. While dopamine
caused inhibition of Na+,K+-ATPase activity in lean rats, this effect was
significantly attenuated in the obese animals. There was significant reduction in
D1-like receptor numbers in the basolateral membranes of obese rats compared with
lean rats with no change in the affinity to the ligand [3H]SCH 23390 between the
two groups of rats. Dopamine failed to stimulate G proteins as measured by
[35S]GTPgammaS binding in the obese rats. Also, dopamine was unable to cause
phospholipase-C activation in obese rats, but it did activate phospholipase-C in
lean rats. These results show that reduction in D1-like receptor numbers and a
defect in receptor-G protein coupling may account for the inability of dopamine
to activate the D1-like receptor-coupled signal transduction pathway and cause
inhibition of Na+,K+-ATPase in the obese hypertensive rats.
PMID- 10691810
TI - Renal dopamine and noradrenaline excretion during CNS-induced natriuresis in
spontaneously hypertensive rats: influence of dietary sodium.
AB - Abnormalities in dopamine (DA) and noradrenaline (NA) activities and sodium
handling may be involved in the pathogenesis of hypertension. The present study
was designed to investigate whether any differences exist between normotensive
Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) in urinary
excretion of DA, NA and sodium after 15 weeks on a low, medium or high sodium
diet and during a subsequent elevation of the cerebroventricular fluid sodium
concentration (CNS-induced natriuresis). Seven features were noted: (1) Basal
sodium and DA excretion after the diet regimen was correlated to the dietary
sodium content in both strains, except that sodium and DA excretion in SHR showed
no further increase after the high sodium diet over and above that after medium
sodium diet. (2) For any given sodium diet, SHR excreted more DA and NA as
compared with WKY. (3) Blood pressure in SHR, as opposed to that in WKY, was
higher after medium and high sodium diet than after low sodium diet. (4) During
CNS-induced natriuresis NA excretion decreased or remained unchanged in WKY, but
increased in SHR. (5) The DA/NA excretion ratio during CNS-induced natriuresis
increased in WKY while decreased in SHR, which would not favour a
natriuretic/vasodilatory response in the latter. (6) The ability of SHR to
respond with CNS-induced natriuresis was attenuated after high sodium diet. (7)
The magnitude of CNS-induced natriuresis was in both strains correlated to the
sodium diet; the higher the dietary sodium content, the greater the natriuretic
response. In conclusion, the study shows some clear differences in the
catecholamine and sodium handling between WKY and SHR which may be involved in
the pathogenesis of hypertension in SHR. Furthermore, increased sodium in the
diet sensitizes the brain and kidney to increase the ability to respond with
natriuresis for a given sodium stimulus.
PMID- 10691811
TI - Do we do what they say we do? coding errors in urology.
AB - OBJECTIVE: To determine the accuracy of routine data coding in a large
multispeciality urological unit. Materials and methods From the clinical records,
the diagnosis and procedure codes were ascribed to 106 finished consultant
episodes (FCEs) in urology, by two urological trainees. The codes were compared
with those ascribed by professional hospital coders (and of which the trainees
were unaware) from information written on the audit form by junior medical staff.
Where there were discrepancies in codes an error was recorded and the stage in
the coding process in which it occurred was determined. RESULTS: Forty-eight
coding errors were found in 38 of the 106 (36%) FCEs; 34 (71%) were caused by
inaccurate coding and 14 (29%) were the result of the incorrect completion of
audit forms. CONCLUSION: The clinical codes generated from the authors'
department do not accurately reflect the clinical practice. If coding errors of
this magnitude are typical of urology units in general, the concept of hospital
performance tables (which will be generated using routine clinical data) is
untenable unless data recording is given higher priority.
PMID- 10691812
TI - Statistical problems with 'optimal' thresholds in studies of new prognostic
factors in urology.
PMID- 10691813
TI - Ethical and legal aspects of clinical hydration and nutritional support.
PMID- 10691814
TI - Reduction of radiation exposure to patients in the follow-up of shockwave
lithotripsy.
AB - OBJECTIVES: To assess, in patients undergoing extracorporeal shock wave
lithotripsy (ESWL), if a policy of using unilateral X-rays of the kidney, ureter
and bladder (hemi-KUB) whenever possible and appropriate during diagnosis and
follow-up, was successful in reducing the radiation exposure associated with
ESWL. PATIENTS AND METHODS: Two groups of patients of statistically comparable
size and demography were assessed retrospectively before and after the
implementation of the policy. All had undergone ESWL for radio-opaque upper
urinary tract stones and all were finally rendered stone-free. The number and
type of all radiological procedures from initial diagnosis of the stone to
documented stone-free status were recorded and the dose calculated. RESULTS: The
appropriate use of hemi-KUB X-rays resulted in a significant mean reduction of
radiation exposure after treatment of 2.28 mSv per patient (P<0.05). Furthermore,
as expected, the radiation dose was clearly but not closely correlated with stone
size (r = 0.419). CONCLUSIONS: The appropriate use of hemi-KUB X-rays during the
follow-up after ESWL is a simple and effective way of significantly reducing the
radiation exposure of such patients.
PMID- 10691815
TI - The indwelling ureteric stent: a 'friendly' procedure with unfriendly high
morbidity.
AB - OBJECTIVE: To review the morbidity and complications of ureteric stent insertion
and to evaluate specifically the effect of an indwelling ureteric stent on the
changes in hydronephrosis after stenting. PATIENTS AND METHODS: In a prospective
study, 110 renal units with a stent in place were evaluated in 90 patients. Of
the 110 stents, 52 were left in place for 3 months, 23 for 6, 11 for 9, 19 for 12
and five (forgotten stents) for 13-30 months. The patients were followed using
plain abdominal X-ray at 1 and 30 days after stenting. They were further followed
using ultrasonography and plain films every 3 months until the scheduled date for
stent removal or the appearance of complications. RESULTS: Thirty-four patients
had fever and bacteriuria after stent insertion. Of the 110 stents, 11 (10%)
fragmented and nine (8%) migrated. Seventeen patients complained of flank pain on
voiding. In 21 renal units (19%) there was no change in the severity of
hydronephrosis, whereas in six (5.5%) hydronephrosis developed or worsened after
stenting. CONCLUSION: Although ureteric stenting is undoubtedly an important
procedure to relieve ureteric obstruction, the indications for stent insertion
should be considered carefully in every patient. The close follow-up of stented
patients is valuable for the early detection of morbidity or complications and in
such cases the stent should be removed or exchanged as soon as possible.
PMID- 10691816
TI - Evidence for the autoregulation of vesical circulation by intravesical potassium
chloride and distension in the normal human bladder.
AB - OBJECTIVES: To determine the influence of distension and intravesical KCl on
vesical blood flow in the normal human bladder. Subjects and methods Nine normal
volunteers underwent comparative cystometry (NaCl vs 0.2 mol/L KCl; filling rate
50 mL/min). Peak systolic blood flow velocity (PSBFV) and end-diastolic blood
flow velocity (EDBFV) were measured in several intramural arteries at a filling
volume of 50 mL and at maximum cystometric capacity (Cmax). For these
measurements a colour Doppler unit fitted with an endorectal probe was used. The
resistance index (RI) was defined as (PSBFV-EDBFV)/PSBFV. RESULTS: In the
presence of NaCl, the mean PSBFV increased significantly from 9 cm/s at 50 mL to
17 cm/s at Cmax (512 mL). Compared with NaCl, KCl induced a significantly higher
mean PSBFV at 50 mL (15 cm/s). With increasing distension the rise in PSBFV with
KCl filling (Cmax 478 mL) was nearly parallel to that obtained on NaCl filling
(mean 22 cm/s); the RI did not change. CONCLUSIONS: Bladder distension and
intravesical KCl significantly increased the PSBFV. The unchanged RI indicated a
concomitant increase in perfusion rates. Hence, the composition of urine (high
potassium concentrations and hyperosmolarity) and its storage govern the
autoregulation (independent of cardiac output) of vesical circulation, probably
by reflexive pathways. These findings provide further evidence for prevesical
arteriovenous shunts.
PMID- 10691817
TI - Oxybutynin for detrusor instability with adjuvant salivary stimulant pastilles to
improve compliance: results of a multicentre, randomized controlled trial.
AB - OBJECTIVE: To test the hypothesis that compliance with oxybutynin would be
improved if the severity of dry mouth could be reduced, thus leading to improved
urinary symptom response and improved outcome, in a randomized, controlled trial
of oxybutynin with or without salivary stimulant pastilles in patients with
detrusor instability. PATIENTS AND METHODS: Sixty-seven women with detrusor
instability were randomized to a variable dose regimen of oxybutynin with (37) or
without (30) salivary stimulant pastilles for 8 weeks. Patients were asked to
complete a baseline voiding diary. In weeks 1 and 2, patients were encouraged to
adjust the dose of oxybutynin themselves to achieve optimum symptomatic control.
A second diary was completed in the sixth week and patients were reviewed at 8
weeks. The outcome measures were the compliance rate, follow-up attendance rate,
maximum dose of medication, changes in voiding and incontinence episodes, and
changes in severity of urgency and of dry mouth symptoms between the first and
sixth week. RESULTS: Of the 67 women, 32 (47%) completed the study; the
proportion completing was the same in both groups. Four patients had stopped the
medication and there was no difference in the distribution of maximum dosage
achieved between the groups. Both groups reported a reduced severity of urgency
symptoms and increased severity of dry mouth. There were no differences in
reported symptom change between the groups during the study. CONCLUSIONS: The
combination of oxybutynin and salivary stimulant pastilles does not improve
compliance or symptom relief compared with oxybutynin alone; it does not allow a
greater dose of oxybutynin to be tolerated.
PMID- 10691818
TI - A randomized double-blind placebo-controlled crossover trial of the efficacy of L
arginine in the treatment of interstitial cystitis.
AB - OBJECTIVES: To determine, in a double-blind placebo-controlled crossover study,
whether L-arginine improves the symptoms of interstitial cystitis (IC), a chronic
condition in which nitric oxide (NO) may be important, as previous open pilot
studies suggested that L-arginine reduced the pain and frequency associated with
IC. PATIENTS AND METHODS: Patients fulfilling the standard diagnostic criteria
for IC were randomized to receive L-arginine (2.4 g/day) or placebo for one
month. After a 2-week 'washout' period they received the other medication.
Patients were assessed at each stage using a validated symptom index, a voiding
diary, urine analysis and records of adverse events. Patients were asked about
overall efficacy at the close of the study. The results were compared using a t
test, with significance indicated at P<0.05. RESULTS: Sixteen (16) patients (mean
age 51.3 years) were enrolled; the mean duration of IC was 5.4 years, the IC
symptom index score 29.1, their nocturnal frequency 3.5 (voided volume 182 mL)
and daytime frequency 12.7 (124 mL). Patients on placebo showed no differences in
any recorded variable over the baseline values. L-arginine caused a statistically
significant reduction in the overall symptom score of 2.2 over baseline, but
there was no difference in voided volume, frequency or nocturia. As there was no
significant difference for any variable between L-arginine and placebo, this
reduction in score should be regarded with caution. Three patients withdrew
because of side-effects (severe headaches, night sweats and flushing).
CONCLUSION: Oral L-arginine produces a statistically significant improvement in
the IC symptom index in patients with IC, but the effect is small. This effect
may not be clinically significant as there were no improvements in the other
variables assessed and no significant difference between the response to L
arginine and placebo. From these results the use of L-arginine cannot be
recommended for treating IC.
PMID- 10691819
TI - The changing pattern of mortality and morbidity from radical cystectomy.
AB - OBJECTIVES: To examine the morbidity and mortality of radical cystectomy as
currently practised, and to compare the findings with historical data. PATIENTS
AND METHODS: The operative mortality and early and late complications were
recorded in 101 consecutive patients (median age 65 years, range 38-81; 33 aged
>70 years) undergoing radical cystectomy between April 1992 and October 1997.
Fifteen patients had relapsed after previous radical radiotherapy. RESULTS: The
median postoperative stay was 14 days (range 8-44). There were two deaths within
60 days of surgery (of patients aged 46 and 59 years) from respiratory failure
and sepsis, respectively. The mortality in the elderly was not more than in other
age groups. The early morbidity included two cases of lower limb insufficiency,
both in the salvage cystectomy group, where the morbidity was significantly
higher than in those undergoing primary cystectomy (chi-squared, P<0.01). Three
patients underwent early re-exploration. There were four clinically significant
episodes of deep vein thrombosis and two pulmonary emboli that were not fatal.
CONCLUSION: As currently practised, radical cystectomy is associated with a lower
mortality (<2%) and morbidity than described previously. The added morbidity of
salvage cystectomy and the acceptable mortality of primary cystectomy suggests
that the treatment of choice for muscle-invasive disease is primary cystectomy,
with external beam radiotherapy reserved for those patients unfit for major
surgical intervention. Age alone should no longer be considered a
contraindication to cystectomy.
PMID- 10691820
TI - Surveillance for bladder cancer: the management of 4.8 million people. South-west
Urologists.
AB - OBJECTIVE: To document the workload of bladder cancer surveillance on the British
urologist. Methods Thirty-one consultant urologists serving a population of 4.8
million were sent postal questionnaires eliciting their views on the management
of superficial bladder cancer. The number, type and outcome of cystoscopies
performed over a 6-week period throughout the region was then assessed
prospectively. Results One person in 1450 in the South-west region is undergoing
follow-up for bladder cancer. Of the responding consultants, 36% would give a
single dose of intravesical chemotherapy within 24 h of resection for a G1/2 pTa
tumour and 84% would perform the first check cystoscopy at 3-4 months. Over the 6
week period of the study, 696 cystoscopies were performed; there was considerable
variation among centres in the choice of cystoscopy type, with 3-80% being rigid
cystoscopies. Overall, there was a positive finding in 31% of the assessments.
CONCLUSION: This study documents the practice of a significant number of UK
urologists in the management of superficial bladder cancer. There are
considerable variations among individuals in the type and timing of check
cystoscopy.
PMID- 10691821
TI - Diagnosis and prediction of recurrence and progression in superficial bladder
cancers with DNA image cytometry and urinary cytology.
AB - OBJECTIVE: To investigate the roles of urinary cytology and image cytometric
analysis of nuclear DNA ploidy pattern in the diagnosis and prediction of
recurrence and/or progression of superficial bladder cancers. PATIENTS AND
METHODS: Aliquots of catheterized urine from 92 patients with primary (23) or
previous (69) superficial bladder cancers were assessed using urine cytology and
image-analysis cytometry independently. RESULTS: Of the 23 primary superficial
transitional cell carcinomas (TCCs), 11 (48%) were detected by urinary cytology
while 12 (52%) were detected by image-analysis cytometry (P>0.05) and 13 (57%)
were revealed by combined cytology and cytometry. Of 42 recurrent superficial
TCCs, 29 (69%) were detected by urinary cytology, whilst 19 (45%) were diagnosed
by cytometry (P<0.05) and 29 (69%) by combined cytology and cytometry. The degree
of ploidy in relation to pathological stage and/or grade showed an increasing
frequency of aneuploid pattern in more invasive and undifferentiated tumours, but
with no statistical significance (P>0.05). The positivity of DNA image cytometry
had no significant association (P>0.05) with tumour recurrence and/or
progression. CONCLUSIONS: DNA image cytometry can provide a limited but not
significant advantage over urinary cytology in the detection of primary
superficial TCCs, but it does not seem to be indicated for the prediction of
tumour recurrence and/or progression.
PMID- 10691822
TI - Does endoscopic laser ablation of the prostate stand the test of time? Five-year
results from a multicentre randomized controlled trial of endoscopic laser
ablation against transurethral resection of the prostate.
AB - OBJECTIVE: To determine the long-term objective and subjective outcome of
patients with benign prostatic enlargement (BPE) treated by endoscopic laser
ablation of the prostate (ELAP), as part of a multicentre randomized controlled
trial of ELAP against TURP. PATIENTS AND METHODS: Initially, 151 patients with
BPE were randomized to undergo either ELAP or TURP, starting in March 1992. ELAP
was performed using the Urolasetrade mark fibre (Bard, Covington, GA, USA) in
conjunction with a Nd:YAG laser source. All patients who had originally
participated in the study were approached 5 years later to obtain a urological
history, American Urological Association (AUA) symptom score and two measurements
of urinary flow rate, with an ultrasonographic assessment of the postvoid
residual urine volume (PVR). RESULTS: The mean duration of follow-up was 61
months; 109 patients were traced, comprising 69 who were alive and well, and had
undergone no further bladder outlet surgery, 26 who had required revision
surgery, 12 who were dead or terminally ill and three who had dementia. Both ELAP
and TURP produced sustained improvements in mean AUA score, maximum flow rate and
PVR, with respective values at 5 years of 6.3, 17.8 mL/s and 76 mL, and 6.5, 20.0
mL/s and 55 mL. Eighteen of 47 ELAP patients (38%) and eight of 51 (16%) TURP
patients underwent revision surgery within the follow-up. CONCLUSION: ELAP and
TURP produced similar subjective and objective outcomes at 5 years. The re
operation rate after ELAP was more than double that after TURP and suggests that
ELAP should not be used routinely in the management of men with BPE.
PMID- 10691823
TI - The development and validation of a quality-of-life measure to assess partner
morbidity in benign prostatic enlargement.
AB - OBJECTIVE: To investigate morbidity in the partners of patients with benign
prostatic enlargement (BPE) by developing and validating a disease-specific
questionnaire. PATIENTS AND METHODS: Phase 1 of the study comprised preliminary
interviews with 15 patients who had newly diagnosed BPE, and with their partners,
to determine the relevant issues for the partners. In phase 2, using these
issues, a questionnaire was produced and tested on the 15 partners. In phase 3
the questionnaire was completed by 90 further partners, 50 at interview and the
next 40 by post. As part of the validation process, the partners were also asked
to complete the Short-Form-36 questionnaire, and the patients the Internation
Prostate Symptom Score (IPSS) and the ICSmale questionnaires. RESULTS: In phase 1
all 15 of the partners were affected by the patients' disease and nine issues
were identified. In phase 2, of the 90 partners, only one had no morbidity from
the patient's symptoms; 71% were worried that the patient may have cancer and 69%
concerned that the patient may require an operation. Only six partners were
present at the patients' urological consultation. The partners' questionnaire
scores were related significantly to the Mental Health and Vitality domains of
the SF36 and with the patients' IPSS. CONCLUSIONS: The study confirmed the
presence of significant morbidity in the partners of patients with BPE. The
degree of partner morbidity was related to the severity of the patients'
symptoms. Many of the questionnaire issues can be addressed in the consulting
room by open discussion with patient and partner.
PMID- 10691824
TI - The pharmacovigilance of tamsulosin: event data on 12484 patients.
AB - OBJECTIVE: To determine drug effectiveness and adverse effects in a
noninterventional observational cohort study of over 10 000 patients treated with
tamsulosin in general medical practice. METHODS: Using prescription-event
monitoring, data were collected of all prescriptions for tamsulosin issued
nationally during June 1996 to January 1998. For each patient entered into the
cohort a computerized longitudinal record of exposure was constructed. The
outcome data, patient information and an opinion about the effectiveness of the
drug were provided by the prescriber, using a standard questionnaire sent 6
months after the initial prescription for tamsulosin. The incidence of each of
almost 2000 events listed in the Drug Safety Research Unit computerized
dictionary was calculated and scrutinized by medical assessors for possible
adverse reactions, and any difference determined between the incidence of each
event in the first month and subsequent months of exposure. All deaths were
followed up to detect possibly drug-related causes. RESULTS: Event data were
obtained on 12484 patients, from the 52.9% of questionnaires returned and that
contained valid event data. Tamsulosin was reported to have been effective in
7428 (78.3%) of the 9487 patients in whom the general practitioners expressed an
opinion about effectiveness. Suspected adverse drug reactions were reported in
only 171 (1.4%) of the cohort. Dizziness, headache, malaise and hypotension were
common to the reported adverse reactions, reasons for stopping the drug and
events of greatest incidence density. None of the 282 deaths that occurred in
this elderly cohort were attributed to the drug. CONCLUSION: This study suggests
that tamsulosin has a highly acceptable benefit-to-risk ratio. No untoward
features not already mentioned in the prescribing guidance were identified.
PMID- 10691825
TI - The role of prostaglandin synthesis in prostate cancer.
PMID- 10691826
TI - Rising incidence of prostate cancer in Scotland: increased risk or increased
detection?
AB - OBJECTIVE: To assess the extent to which the increasing incidence of prostate
cancer in Scotland can be explained by increased detection, particularly through
transurethral resection of the prostate (TURP) and use of the prostate-specific
antigen (PSA) test. Subjects and methods This population-based study was confined
to men resident in Scotland and aged > or =50 years. Temporal trends were
examined in age-specific and age-standardized incidence, mortality and TURP
rates, and PSA testing rates during 1981-1996. Also analysed were the
geographical variations in age-standardized incidence and mortality rates during
two distinct periods, 1984-1986 (before PSA testing) and 1994-1996 (after PSA
testing). Finally, incidence rates and relative survival at 5 years were
calculated by age group and 5-year periods of diagnosis during 1968-1992.
RESULTS: The incidence of prostate cancer in men aged > or = 50 years increased
from an age-standardized rate of 142.0 per 100 000 in 1981 to 240.9 in 1996, with
the steepest increase occurring between 1992 and 1993. The mortality rate
increased similarly until 1993, but was relatively stable thereafter, falling
slightly in 1996. In 1981-1988, incidence rates were closely correlated with TURP
rates (r = 0.98, P<0.001). In 1989-1996, incidence was closely correlated with
PSA testing rates (r = 0.98, P<0.001). By 1994-1996, incidence rates varied
substantially between Scottish mainland health boards (range 167.7-303.0 per 100
000), with much less variation in mortality rates (90.7-110.0). Relative survival
has increased recently in all age groups although, in the era before PSA testing,
survival was reasonably stable despite increasing incidence. CONCLUSION: Although
there may have been a true increase in risk, much of the observed increase in the
incidence of prostate cancer in Scotland between 1981 and 1996 has been caused by
increased detection, leading recently to considerable variation among different
areas of the country. The extent to which this represents the early diagnosis of
tumours which would eventually cause symptoms or be life-threatening, or
detection of latent disease which would never have become symptomatic, is not
clear. There is no evidence so far that the increased incidence is associated
with any substantial reduction in mortality.
PMID- 10691827
TI - Trends in the curative treatment of localized prostate cancer after the
introduction of prostate-specific antigen: data from the Rotterdam Cancer
Registry.
AB - OBJECTIVE: To investigate changes in the incidence and treatment of prostate
cancer over the period in which new diagnostic tools were introduced and the
attitude towards treatment was changing. PATIENTS AND METHODS: Information on the
extent of disease and treatment of patients diagnosed with prostate cancer within
the Rotterdam region was retrieved from the Rotterdam Cancer Registry. RESULTS:
In the period 1989-95, 4344 patients were diagnosed with prostate cancer and the
age-standardized incidence increased from 62 to 125 per 100 000 men. This
increase mainly comprised tumours localized to the prostate, while the incidence
of advanced cancers remained stable. The proportion of poorly differentiated
tumours decreased from 33% in 1989 to 24% in 1995. In the same period the number
of patients receiving radiotherapy increased from 80 to 258, while the annual
number of radical prostatectomies rose from 17 to 159. Radiotherapy was the
preferred type of treatment in patients over 70 years of age, whereas radical
prostatectomy was used more frequently in younger patients with localized
tumours. CONCLUSION: While the value of screening for prostate cancer remains in
debate, incidence and treatment patterns are changing rapidly. Information on
patterns of care is needed to interpret future mortality data and to plan
resources for adequate health care.
PMID- 10691828
TI - PC-SPES, a dietary supplement for the treatment of hormone-refractory prostate
cancer.
AB - OBJECTIVE: To assess the effectiveness of PC-SPES, a dietary supplement
containing eight herbal extracts, which is a popular alternative therapy among
patients with hormone-refractory prostate cancer; anecdotal reports claim that
this agent provides relief of metastatic pain, improvements in quality of life
and reduction of prostatic specific antigen (PSA) level. PATIENTS AND METHODS:
Sixteen men treated for advanced metastatic prostate cancer (stage D3) with
either orchidectomy or a luteinizing-hormone releasing hormone agonist, with or
without anti-androgen, were enrolled into a prospective clinical trial to
evaluate the possible toxic and beneficial effects of PC-SPES. After hormone
ablative therapy had failed, and with established disease progression, all
patients received supplemental treatment with PC-SPES (2.88 g daily) for 5
months. Hormonal therapy was continued throughout the trial to avoid the known
withdrawal effect of anti-androgen on PSA levels. RESULTS: The supplemental
intake of PC-SPES was associated with significant (P<0.05-0.01) improvements in
quality-of-life measures, reductions in patient's pain ratings (P<0.05-0.01), and
a decline in PSA levels (P<0.01), with no major side-effects. CONCLUSIONS: These
results support the anecdotal reports of the beneficial effects of PC-SPES as a
comparable alternative to current management regimens in hormone-refractory
prostate cancer. However, no conclusions can be drawn about the long-term effects
of this new herbal therapy.
PMID- 10691829
TI - The transverse colonic reservoir: the Unicamp technique.
AB - OBJECTIVE: To present the results of a continent and nonrefluxing transverse
colonic urinary reservoir technique. PATIENTS AND METHODS: Twenty patients who
had received high doses of irradiation underwent construction of transverse
colonic reservoir as a primary form of urinary diversion. Fourteen patients had a
vesicovaginal fistula after definitive radiation therapy for gynaecological
tumours and six had radiation therapy for invasive bladder cancer as a definitive
treatment. They were followed for a median (range) of 4.5(1-8) years. Intravenous
pyelography before diversion showed mild hydronephrosis in 10 patients. RESULTS:
After diversion, hydronephrosis improved in four patients and no upper tract
deteriorated. All but one of the pouchograms showed no ureteric reflux. All the
patients required clean intermittent self-catheterization every 3-4 h. Persistent
asymptomatic bacteriuria was present in 14 patients, although clinical urinary
tract infections were not reported. A moderate metabolic acidosis was present in
12 patients, but none required treatment. The urodynamic evaluation revealed a
median (range) reservoir capacity of 450 (350-600) mL, with no contractions or
contractions of <35 cm H2O. CONCLUSION: These results suggest that the Unicamp
technique for constructing a transverse colonic reservoir is a safe and effective
diversion, and is recommended as an alternative method for patients treated by
pelvic irradiation.
PMID- 10691830
TI - Artificial sphincter insertion after radiotherapy: is it worthwhile?
AB - OBJECTIVE: To determine the influence of radiotherapy on the outcome of
artificial urinary sphincter implantation. PATIENTS AND METHODS: A series of 72
men who had an artificial urinary sphincter inserted were reviewed
retrospectively, analysing in detail the information from 15 patients with a past
history of pelvic radiotherapy. RESULTS: In those who had undergone radiotherapy,
the complication rate was higher, both for re-operation (eight of 15) and
infection (three); 11 of the 15 patients were continent after surgery, compared
with 51 (89%) of the 57 in the unirradiated group. CONCLUSIONS: An artificial
sphincter can be inserted after pelvic radiotherapy reasonably successfully, but
at the cost of a high complication and re-operation rate. Patients with a
previous history of radiotherapy should be informed of the higher risk of
surgical revision associated with insertion of the prosthesis.
PMID- 10691831
TI - Priapism in adult Nigerians.
AB - OBJECTIVES: To review the presentation and treatment of adult Nigerians with
priapism. PATIENTS AND METHODS: Thirty-five men (mean age 35 years, range 20-54)
were seen over a 12-year period. All patients underwent an immediate modified or
conventional cavernospongiosus shunt and were assessed at 2, 6 and 12 weeks after
discharge for erection, orgasm and fibrosis of corpora cavernosa. RESULTS: Ten
patients initially presented to traditional healers and 13 presented early to
qualified medical practitioners, and were managed conservatively. As a result, 21
of the 35 patients presented to the author's hospital 6-10 days after the onset
of erection. Many did not realise that priapism was abnormal, or had no money to
attend hospital. After surgical treatment detumescence was obtained in all
patients and maintained. At 12 weeks, 14 patients had normal erections, 13
reduced erections and eight no erections. A local aphrodisiac was identified as
the commonest predisposing factor, followed by sickle-cell disease. CONCLUSION:
This study shows clearly that even if a patient with priapism presents late,
vigorous treatment in the form of an adequate shunt should be undertaken as soon
as possible, as this is the only chance the patient has to regain potency.
PMID- 10691832
TI - The Mitrofanoff procedure: does it last?
AB - OBJECTIVE: To examine the long-term effectiveness of the Mitrofanoff principle
and establish if the catheterizing channel is sufficiently robust for long-term
use. PATIENTS AND METHODS: Ten patients who had undergone Mitrofanoff
reconstruction between 1989 and 1991 (minimum follow-up 10 years) were offered
reinterview by one of the authors (J.F.), which involved a structured
questionnaire assessing catheterization, continence and complications. RESULTS:
One patient had died; nine patients were alive and eight agreed to the structured
interview. All the patients had their original stoma and all were completely
continent. Four of the patients had experienced stenosis, four had had stones and
four had been ill with urinary tract infection(s). CONCLUSION: Despite the
complications of infection, stones and some episodic stenosis, the Mitrofanoff
channel remains functional for long periods without sustaining structural damage.
PMID- 10691833
TI - Bladder neck reconstruction in classic bladder exstrophy: the role of osteotomy
in the development of continence.
AB - OBJECTIVE: To assess the role of osteotomy at the time of bladder neck
reconstruction (BNR) for continence in classic bladder exstrophy, in which
closure of the pelvic ring and reconstitution of the pelvic diaphragm may affect
eventual continence. PATIENTS AND METHODS: The results of using osteotomy at the
time of BNR in 29 children were reviewed. The mean bladder capacity before BNR
was 76 mL. The indications for osteotomy were a wide pubic diastasis and a soft
intersymphyseal bar. After osteotomy, all children were maintained in external
fixation and lower-extremity traction for 6-8 weeks. RESULTS: Complications of
osteotomy were limited to a partial femoral nerve palsy (one patient) and delayed
union of fragments (one patient). Complications of BNR included urethral
stricture (five patients) and bladder calculi (six patients). Continence results
were modest, with 11 of 29 children (38%) dry during the day (dry interval >3 h)
and eight of 29 (28%) dry at night. Eight children had daytime dry intervals of
approximately 3 h. The mean preoperative bladder capacity in children who were
dry both day and night was 101 mL. CONCLUSIONS: The preoperative bladder capacity
remains a key determinant for the attainment of continence after BNR in the
reconstruction of classic bladder exstrophy. Osteotomy allows pelvic closure and
thus improves cosmesis of the mons and stabilizes the BNR in patients with a soft
intersymphyseal bar, but seems to have no effect on continence when performed at
the time of bladder neck plasty.
PMID- 10691834
TI - Is only meatoplasty a legitimate surgical solution for extreme distal
hypospadias? A long-term follow-up after adolescence.
AB - OBJECTIVE: To review the long-term outcome of glanular hypospadias repair for
extreme distal hypospadias based on simple dorsal Browne meatoplasty and
circumcision, with particular attention to patient satisfaction. PATIENTS AND
METHODS: A review of medical records identified 124 patients who underwent
surgery for hypospadias between 1970 and 1979. Their age at operation ranged from
3 months to 13 years. The operation, performed as a day-case, included dorsal
Browne meatoplasty for meatal advancement, based upon the Heineke-Mikulicz
principle, using three absorbable sutures and often circumcision. There were no
immediate complications. A questionnaire was sent to 111 patients whose present
address was available. Two patients had died since the operation and of the 109
remaining patients, 43 (39%) replied. RESULTS: The patients were aged 16-31 years
at the time of assessment, giving a follow-up of 18 (13-23) years. Seven of the
43 patients were married. Seven patients had complained of some difficulties with
urination, four reporting a poor urinary flow. The stream was directed forward in
32 patients and to some degree downwards in 11, still enabling all the patients
to urinate while standing with a single stream. Thirty-two patients had had
sexual experience, with no functional problems. Twenty-three defined their penile
appearance as normal and 20 as abnormal. Overall, 24 (56%) reported complete
satisfaction, 11 (25%) partial satisfaction and eight (19%) were dissatisfied
with the surgical result. CONCLUSION: As there are few published reports about
the long-term outcome and patient satisfaction after hypospadias repair, it is
difficult to draw clear conclusions. However, this simple procedure is a
legitimate surgical option for extremely distal glanular hypospadias.
PMID- 10691835
TI - Comparison of marker protein expression in benign prostatic hyperplasia in vivo
and in vitro.
AB - OBJECTIVE: To use multiple immunofluorescence to compare the in vivo and in vitro
expression of tissue-specific proteins in BPH. Materials and methods Pure
populations of prostate epithelial and stromal cells were produced using standard
methods. Serum-free media for epithelial cells were compared. Co-localization of
proteins was compared in frozen-tissue sections and cultured cells by
simultaneous multiple immunofluorescence, and recorded using a high-resolution
charge-coupled device camera. RESULTS: In contrast to the other serum-free media
tested, epithelial cells grew without squamous differentiation or vacuolation in
prostate epithelial growth medium (PrEGM, Clonetics, BioWhittaker UK Ltd., Berks,
UK). These cells were predominantly of a basal phenotype, with some cells showing
a luminal phenotype. Most of the stromal cells had features of myofibroblasts,
but smooth muscle cells and fibroblasts also were present. CONCLUSION: PrEGM is a
commercially available serum-free medium in which primary cultures of prostate
epithelial cells can be propagated reproducibly. This study provides a
comprehensive description of tissue-specific protein expression in BPH in vivo
and in vitro. The use of simultaneous multiple immunofluorescence to study co
localization has resulted in a more precise definition of phenotype than has
previously been possible, thereby establishing the relevance of the in vitro
model system BPH.
PMID- 10691836
TI - Analysis of CD44 isoform v10 expression and its prognostic value in renal cell
carcinoma.
AB - OBJECTIVE: To examine the expression of CD44 isoform v10 (CD44v10) in patients
with renal cell carcinoma (RCC), analyse its role in RCC and its relationship
with conventional clinical-histopathological experience. Materials and methods
Sixty-four RCC specimens and five metastatic specimens were analysed
immunohistochemically using a CD44v10 specific antibody. The expression of
CD44v10 was compared with the histological grade and clinical or pathological
stage of the tumours. RESULTS: Of the 64 primary tumour specimens, 22 (34%)
expressed CD44v10 protein; all of these positive specimens were clear-cell and
mixed-cell RCC. Staining was also positive in four of five metastatic specimens
and negative in all four cases of granular cell carcinoma. CD44v10 expression was
significantly correlated with the histological grade (P<0.0001), clinical stage
(P = 0.0050) and pathological stage (P = 0.0143) of the tumours. The prognosis
for patients with clear-cell RCC who were CD44v10-positive was worse than for
patients who were CD44v10-negative (P<0.0001). In subgroups with different tumour
stage (< or =pT2 or > or =pT3), the prognosis for patients with positive CD44v10
expression was also worse than for those with no expression (P<0.05). CONCLUSION:
The expression of CD44v10 correlated significantly with histological grade,
clinical and pathological stage, and with survival in patients with clear-cell
RCC. CD44v10 protein may play a role in the progression of clear-cell and mixed
cell RCC, and thus the analysis of CD44v10 expression may provide useful
prognostic information.
PMID- 10691837
TI - Comparative physiology and biochemistry of rat and rabbit urinary bladder.
AB - OBJECTIVE: To compare directly the biochemistry and contractile responses of rat
and rabbit bladder to different stimuli. Materials and methods Sexually mature
male New Zealand White rabbits and Sprague Dawley rats were compared. Each
bladder was excised while the animal was anaesthetized; longitudinal bladder
strips were cut and then mounted in an organ bath. Tension (2 g) was placed on
all strips and each underwent field stimulation (FS) for a total of 20 s at 1-32
Hz, 1 ms and 80 V and was exposed to carbachol (100 micromol/L), ATP (2 mmol/L)
and KCl (120 mmol/L). The tension was monitored continually using a polygraph and
data stored digitally in a computer. The responses to each stimulus were
determined as the maximum tension generated, maximum rate of tension generation
and duration to a maximum response. The Ca2+- ATPase activity of the rat and
rabbit bladder was determined. Bladder pressures were then predicted from the
strip data using Laplace's law and compared with published values. RESULTS:
Contractile responses (per unit tissue mass) of rat bladder strips were
significantly greater than those of rabbit bladder strips at all frequencies of
FS and to carbachol, KCl and ATP. The rate of contractile force generated by rat
bladder strips in response to all stimuli were significantly greater than that
generated by rabbit strips. Rabbit bladder strips took significantly longer to
generate maximum tension than did rat bladder strips in response to
pharmacological stimuli. In response to FS, rat strips took significantly longer
than rabbit strips to generate maximum tension. Although the predicted rat
bladder pressures were significantly greater than those for rabbit, the predicted
pressures for both the rat and rabbit were significantly lower than the pressure
responses of the isolated whole bladder model. The contractile data correlated
well with the Ca2+-ATPase activity data; rat bladder had seven times the enzyme
activity of rabbit bladder. CONCLUSION: Per unit mass, rat bladder is capable of
generating more than five times the tension of rabbit bladder. Similarly, the
rate of tension generation by rat bladder is three to five times greater than
that by rabbit bladder. The duration to maximum tension generated in response to
FS compared with pharmacological stimuli was affected by the inherent difference
in the rate of contractile response to electrical activation compared with agents
which diffuse through tissue, and by the difference in size between rat and
rabbit bladder smooth muscle cells.
PMID- 10691838
TI - Telomerase activity as a potential marker in preneoplastic bladder lesions.
AB - OBJECTIVE: To assess telomerase activity (involved in cell immortalization and
detectable in most malignant tumours but not in normal somatic tissues) as a
marker in cancer diagnosis. PATIENTS AND METHODS: Tissue telomerase activity was
assayed by two different techniques, the telomeric repeat amplification protocol
polymerase chain reaction (TRAP-PCR) and a telomerase PCR-enzyme linked
immunosorbent assay. Malignant and inflammatory bladder lesions and their
adjacent normal tissues were assessed for telomerase activity in a group of 18
patients, 14 of whom had urothelial carcinoma and four a nonspecific inflammatory
lesion of the bladder. RESULTS: Eleven of the 14 tumour samples analysed were
telomerase-positive and two of the three telomerase-negative tumour samples had a
detectable 'telomerase inhibitor'. In the apparently normal tissues next to
bladder tumours, four of the 14 specimens were telomerase-positive.
Interestingly, these lesions were always next to high-grade muscle-invasive
bladder tumours (pT2G3). Two of the four nonspecific inflammatory lesions (one of
cystitis glandularis and one of severe dysplasia), known to be preneoplastic
lesions, were also telomerase-positive. CONCLUSION: These results strongly
suggest that the reactivation of telomerase may be an early event in bladder
carcinogenesis, preceding morphological changes related to malignant
transformation. Telomerase activity may therefore be useful both as an indicator
of malignant potential in preneoplastic lesions, e.g. cystitis glandularis and
severe dysplasia, and as a prognostic marker of bladder tumour relapse or
progression.
PMID- 10691839
TI - Gastrinaemia and G-cell density in the antral gastrocystoplasty: an experimental
study in rats.
AB - OBJECTIVE: To evaluate gastrinaemia and G-cell density in the antrum incorporated
into the bladder of rats after antrocystoplasty. Materials and methods Thirty-two
adult, female Wistar EPM-1 rats (body weight 200-220 g) were divided into four
equal groups that underwent; group 1, no treatment (controls); group 2, a sham
operation; group 3, antrectomy; and group 4, antrocystoplasty. The rats were
assessed 2 months after treatment, and gastrinaemia and the G-cell density
determined in the antrum mucosa incorporated into the bladder. RESULTS: Compared
with group 1, serum gastrin was significantly lower in group 3 (P<0.05) and the G
cell density lower in group 4 (P<0.05), although there was no decrease in
gastrinaemia in group 4. CONCLUSION: Antrocystoplasty in rats did not affect
gastrinaemia but reduced the number of G cells in the antrum incorporated into
the bladder.
PMID- 10691840
TI - Heat-induced apoptosis in human prostatic stromal cells.
AB - OBJECTIVE: To determine whether heat, used in transurethral microwave
thermotherapy (TUMT) for benign prostatic hyperplasia and which causes necrotic
lesions within the adenoma, induces apoptosis in benign human prostatic stromal
cells. Materials and methods Prostatic stromal cells were cultured from benign
human prostatic tissue. The origin of the cells was identified by
immunohistochemical staining and transmission electron microscopy. Cell cultures
were exposed to moderate hyperthermia (47 degrees C) for 1 h and any apoptosis
detected by light microscopy, transmission electron microscopy and the
measurement of induced caspase-3-like activity. RESULTS: The cultures contained a
mixed population of smooth muscle cells and myofibroblasts. Twenty-four hours
after heat exposure, 76% of the cells were apoptotic and the caspase activity had
increased, whereas only 14% of the cells were necrotic. CONCLUSION: Moderate
hyperthermia induces apoptosis in cultured human prostatic stromal cells.
PMID- 10691841
TI - Prostate selectivity of JTH-601-G1, an active metabolite of JTH-601, in dogs.
AB - OBJECTIVE: To evaluate the effect of JTH-601-G1, an active metabolite and
glucuronide conjugate of JTH-601 (an alpha1-adrenoceptor antagonist), on smooth
muscle contraction in canine prostate and artery, and to examine the effect of
JTH-601-G1 on prostatic urethral pressure and blood pressure in anaesthetized
dogs. Materials and methods Male beagle dogs were used in both an in vitro and an
in vivo study. In the former, the prostate and right common carotid artery were
isolated, and smooth muscle strips from the prostate and open-ring strips from
the carotid artery prepared. The effects of JTH-601-G1 on phenylephrine- and
noradrenaline-induced contraction were assessed in these tissues. In the in vivo
study, four dogs were anaesthetized and the change in urethral pressure, blood
pressure and heart rate measured continuously. Vehicle (saline) and JTH-601-G1
were then infused intravenously in increasing doses (0.33-3.3 microg/kg/min for
30 min). In three other dogs, the effect of JTH-601-G1 infusion at a higher rate
(25 microg/kg/min for 3 h) on blood pressure was evaluated, and the plasma
concentration of JTH-601-G1 measured using high-performance liquid chromatography
mass spectrometry. RESULTS: Of the distinct metabolites of JTH-601, JTH-601-G1
had the most potent alpha1-adrenoceptor antagonistic effect in isolated canine
prostate. JTH-601-G1 also antagonized alpha1-adrenoceptor agonist-induced
contraction in common carotid artery, but the pA2 value in the artery was
approximately 25 times higher than that in the prostate. In anaesthetized dogs,
JTH-601-G1 decreased urethral pressure in a dose-dependent manner; at the highest
dose, urethral pressure decreased by 24.5% and blood pressure by 7.0%. However,
there was no significant change in heart rate at any dose. The plasma
concentration of JTH-601-G1 increased with the dose of JTH-601-G1, but the
concentration of both JTH-601 and other metabolites was below the detection
limit. The higher JTH-601-G1 infusion rate caused blood pressure to decrease by
only 6-10% even at JTH-601-G1 plasma concentrations of approximately 1500 ng/mL
during the infusion. Although there was a negative correlation between mean blood
pressure and plasma JTH-601-G1 concentration, the decrease in blood pressure was
small compared with the reduction in urethral pressure. CONCLUSION: JTH-601-G1
appears to be a major active metabolite of JTH-601 but with a higher selectivity
for canine prostate than artery. The results also indicate that in addition to
the alpha1A-adrenoceptor, the alpha1L-adrenoceptor plays an important prostatic
selective role in smooth muscle contraction via the alpha1-adrenoceptor.
PMID- 10691842
TI - Using an instructional model to teach clean intermittent catheterization to
children.
PMID- 10691843
TI - Development of a urethrorectal fistula after transurethral microwave
thermotherapy for benign prostatic hyperplasia.
PMID- 10691844
TI - Perivesical inflammation after early mitomycin C instillation.
PMID- 10691845
TI - The management of high-risk lymphoblastic leukaemia in children.
PMID- 10691846
TI - DDAVP is not a panacea for children with bleeding disorders.
PMID- 10691847
TI - Immunoplatelet counting: a proposed new reference procedure.
AB - Given the high degree of interoperator error and poor precision of manual
platelet counting, it has recently been proposed that an immunoplatelet counting
method could become the new reference procedure. Platelets are identified
immunologically with a suitable monoclonal antibody, and the platelet count is
derived from the ratio of fluorescent platelet events to collected red blood cell
(RBC) events that are also counted by a reliable and calibrated standard
impedance counter (RBC ratio). In this study, we have set up a rapid and simple
method for immunoplatelet counting and simultaneously compared the RBC ratio with
the bead ratio derived from two different preparations of commercial calibration
beads (Trucount and FlowCount beads). Comparison of the level of imprecision of
the RBC ratio with either the manual count or bead ratios revealed a superior
coefficient of variation of < 5% even in samples with a platelet count < 20 x
10(9)/l. The RBC ratio correlated extremely well with the existing manual phase
reference method (r2 = 0.93) and especially well with three different commercial
impedance counters and a dual-angle optical counter (r2 = 0.98-0.99). However, at
< 100 x 10(9)/l, the correlation of the RBC ratio with the dual-angle optical
count (ADVIA 120) (r2 = 0.96) was superior to all impedance counters. This
suggests that automated optical counting methods may be more accurate at
determining platelet counts in thrombocytopenic samples. As the RBC ratio is
rapid, cheap and relatively easy to perform, we propose that this method could
replace the manual count as a new international reference method.
PMID- 10691848
TI - Defective fibrinogen polymerization associated with a novel gamma279Ala-->Asp
mutation.
AB - A woman with menorrhagia was investigated for a suspected fibrinogen mutation
when coagulation tests revealed prolonged thrombin (55 s) and reptilase (43 s)
times together with a functional and an antigenic fibrinogen concentration of 0.7
and 2.8 mg/ml respectively. Heterozygosity for a gamma-chain mutation was
suggested by a doublet gamma band on SDS-PAGE and an increased negative charge
was observed on isoelectric focusing of HPLC-isolated gamma-chains. Electrospray
ionization mass spectrometry revealed a gamma-chain mass of 48 411 Da, which was
20 Da more than the control value of 48 391 Da. Because the normal and variant
gamma-chains were not resolved, this implied a 40-Da increase in 50% of the gamma
molecules. An increased negative charge and a 44-Da increase in mass was verified
when DNA sequencing showed heterozygosity for an Ala (GCC)-->Asp (GAC)
substitution at codon 279 of the gamma-gene. Fibrin polymerization curves
indicated a delay in the onset, and a decrease in the rate, of polymerization.
Examination of crystal structures showed that the adjacent Tyr-gamma280 side
chain is involved in bonding across the D-D interface, and from the proximity of
the gamma279Ala-->Asp mutation it would appear that this perturbs the end-to-end
DD interactions between fibrin units of the growing polymer.
PMID- 10691849
TI - Intracellular accumulation of factor VIII induced by missense mutations Arg593-
>Cys and Asn618-->Ser explains cross-reacting material-reduced haemophilia A.
AB - Patients with cross-reacting material (CRM)-reduced haemophilia A exhibit reduced
levels of factor VIII antigen. In this study, we determined the molecular basis
of the genetic defect in the factor VIII gene induced by either the Arg593-->Cys
or the Asn618-->Ser missense mutation, identified in two CRM-reduced haemophilia
A patients. We introduced either the Arg593-->Cys or the Asn618-->Ser mutation
into a B-domain-deleted factor VIII cDNA and expressed the modified cDNAs in C127
cells. Reduced levels of factor VIII activity and factor VIII antigen in
conditioned medium of transfected cells indicated that the secretion of both
factor VIII variants was impaired. The ratio of factor VIII antigen present in
cell extract to that in conditioned medium was 1.9 and 2.4 times higher for
rFVIII-R593C and rFVIII-N618S, respectively, than for rFVIII. Metabolic labelling
and immunoprecipitation of transfected cells revealed that rFVIII-R593C and
rFVIII-N618S persisted somewhat longer inside the cell than factor rFVIII.
Intracellular accumulation and subsequent degradation of factor VIII-R593C and
factor VIII-N618S may explain the reduced levels of both factor VIII activity and
antigen in plasma of mild haemophilia A patients with corresponding genetic
defects.
PMID- 10691850
TI - A novel polymorphism in intron 1a of the human factor VII gene (G73A): study of a
healthy Italian population and of 190 young survivors of myocardial infarction.
AB - We have identified a novel polymorphism located in intron 1a of the human factor
VII gene, caused by the nucleotide change G to A at position + 73. In a
population of 128 healthy individuals from northern Italy, the variant A73 allele
had a frequency of 0.21, whereas the frequency of the previously reported 10 bp
insertion allele located at -323 in the promoter region was 0.17 and that of the
Q353 allele in the catalytic region of the factor VII gene was 0. 20. In 75% of
the healthy individuals, the A73 allele was present together with the 10 bp
insertion and the Q353 alleles, indicating a strong linkage disequilibrium. The
concomitant presence of A73 with both the 10 bp and the Q353 alleles was
associated with the lowest factor VII levels, measured as coagulant activity,
activated factor VII and factor VII antigen. The G73A polymorphism was also
evaluated in 190 survivors of myocardial infarction who had experienced the event
before the age of 45 years and in 179 individuals with a negative exercise test
matched with patients for sex, age and geographical origin. Patients carrying the
A73 allele associated with lower factor VII levels tended to have a lower risk of
myocardial infarction (adjusted odds ratio 0.54; 95% confidence intervals 0.29
0.99). In conclusion, we found a novel variant allele in intron 1a of the human
factor VII gene that is often associated in healthy individuals with the 10 bp
and Q353 alleles in the promoter and catalytic region of the same gene. This
intronic mutation, alone or in association with other factor VII gene
polymorphisms, might confer protection against myocardial infarction in the
young.
PMID- 10691851
TI - Combined alpha interferon and ribavirin for the treatment of hepatitis C in
patients with hereditary bleeding disorders.
AB - Patients with hereditary bleeding disorders who received non-virally inactivated
plasma-derived clotting factor concentrates before the mid-1980s invariably
became infected with hepatitis C virus (HCV). Therapy with interferon alpha (IFN
alpha) alone has been disappointing in this group. We conducted an open-label
study, using a combination of IFN-alpha2b (3 million units three times per week)
and ribavirin 1-1.2 g/d in 28 patients with hereditary bleeding disorders. Twenty
one of the 28 patients had liver biopsy-confirmed chronic hepatitis (median
histological activity index 5; range 1-10) and all patients were HCV RNA positive
by PCR. Virological response rate to therapy at 3 months was 82% (23 out of 28).
Three HIV co-infected patients showed an early virological response with loss of
HCV RNA, but two subsequently relapsed after 3 and 6 months of therapy. Four
patients stopped treatment early (one at 4, one at 7 and two at 9 months) because
of treatment-related side effects, although three of these have maintained a
virological response. Seventeen patients completed the 48-week course. Twenty of
the 28 (71%) treated have had a durable virological response with a median follow
up of 16 months (range 1-24). Combination therapy represents a significant
advance in the treatment of hepatitis C in patients with hereditary bleeding
disorders.
PMID- 10691852
TI - Type 1 von Willebrand disease - a clinical retrospective study of the diagnosis,
the influence of the ABO blood group and the role of the bleeding history.
AB - This clinical retrospective study investigated the difficulties in diagnosing
type 1 von Willebrand disease (VWD). A total of 246 patients previously diagnosed
with type 1 VWD were reclassified into 'possible' type 1 VWD (patients with low
levels of VWF adjusted for the blood group and either a significant bleeding
history or family history) and 'definite' type 1 VWD, requiring low levels of von
Willebrand factor (VWF), a bleeding history and inheritance. On reclassification,
only 144/246 (59%) patients had low VWF levels adjusted for blood group, 88/246
(36%) patients met all the criteria for 'definite' type 1 VWD and 51/246 (21%)
patients were 'possible' type 1 VWD. A significant proportion of patients,
102/246 (42%), remained an indeterminate group with blood type O, VWF levels
between 35 and 50 U/dl and personal and/or family bleeding history. This subgroup
might require reclassification as 'not VWD'. However, a similar bleeding tendency
was found in two matched groups of patients of blood groups O and non-O and VWF
levels between 35 and 50 U/dl. These results suggest that the use of ABO adjusted
ranges for VWF levels might not be essential for diagnosis, because bleeding
symptoms may depend on the VWF level regardless of the ABO type. Of the
diagnostic criteria, the bleeding history was of prime importance in the clinical
decision to diagnose and treat type 1 VWD. These observations could help in the
reconsideration of how the criteria for diagnosing type 1 VWD could be adjusted
in order to maximize their clinical relevance.
PMID- 10691853
TI - Type II protein C deficiency: identification and molecular modelling of two
natural mutants with low anticoagulant and normal amidolytic activity.
AB - Two mutations in exons 3 and 9 of the protein C gene were identified by
amplification and sequencing from symptomatic probands referred for venous
thromboembolism and thrombophilia screening. The phenotype associated with the
mutations is a type II protein C deficiency with normal amidolytic activity. In
one family, the mutation in exon 3 (G3545-->A), which predicts an R9 to H
substitution in the Gla domain, was identified. A mutation in exon 9 (G10899-
>A), which predicts an R352 to W substitution in the catalytic site, was
identified in the second family and has been reported previously in association
with type II deficiency with low amidolytic activity. Western blotting of the
purified proteins from the probands' plasma did not show any abnormal migratory
pattern. Molecular modelling suggested a possible impairment in the recently
described Na+ binding pocket for the R352-->W mutant. No conclusions could be
drawn relative to the R9-->H mutant.
PMID- 10691854
TI - Prevalence of the post-thrombotic syndrome in young women with previous venous
thromboembolism.
AB - The prevalence of mild, moderate and severe post-thrombotic syndrome (PTS) among
43 young women with a previous single episode of deep vein thrombosis (DVT) was
67%, 7% and 0% respectively. Subjects were assessed at a mean 51 months after the
event. Moderate PTS was more common in women with recurrent (n = 9) DVT (44%, P <
0.001). Chronic venous insufficiency, assessed by light reflection rheography
(LRR), was significantly (P < 0.05) more prevalent in women with single previous
DVT (n = 40), recurrent DVT (n = 9) and isolated pulmonary embolism (PE) (n = 19)
compared with healthy age-matched controls (odds ratios 10.9, 52.4 and 3.8
respectively). LRR findings correlated with moderate, but not mild, PTS. There
was no correlation between development of PTS and body mass index.
PMID- 10691855
TI - Human osteoblast-like cells and osteosarcoma cell lines synthesize macrophage
inhibitory protein 1alpha in response to interleukin 1beta and tumour necrosis
factor alpha stimulation in vitro.
AB - Recent investigations have demonstrated that macrophage inhibitory protein 1alpha
(MIP-1alpha) plays a critical role in haematopoiesis. In part, MIP-1alpha limits
the differentiation of early haematopoietic cells, thereby ensuring that
sufficient quantities of blood precursors are available to meet haematopoietic
demands. MIP-1alpha is produced by cells of the marrow microenvironment (marrow
stromal cells) in response to a variety of stimuli, including interleukin 1beta
(IL-1beta) and tumour necrosis factor alpha (TNF-alpha). Our recent
investigations demonstrated that normal human osteoblast-like cells (HOBs)
maintain the early phenotype of haematopoietic precursors, like other members of
the bone marrow stroma. Although the precise molecular mechanisms for these
observations have not been determined, the production of MIP-1alpha remains one
such possibility. In the present study, we investigated whether cells of the
osteoblast lineage under basal, IL-1beta and/or TNF-alpha stimulation produce MIP
1alpha. We observed that IL-1beta and TNF-alpha stimulated HOBs and human
osteosarcoma cells to rapidly express MIP-1alpha mRNA and to secrete large
quantities of the protein. MIP-1alpha mRNA and protein was not, however, detected
under basal conditions. Perhaps more importantly, enriched human CD34+ bone
marrow cells in co-culture may be capable of stimulating the expression of MIP
1alpha mRNA by HOBs in vitro. These findings suggest that human osteoblast-like
cells may produce MIP-1alpha in vivo to support haematopoiesis at sites where
osteoblasts and haematopoietic cells are closely associated.
PMID- 10691856
TI - Oral magnesium pidolate: effects of long-term administration in patients with
sickle cell disease.
AB - Prevention of erythrocyte dehydration by specific blockade of the transport
pathways promoting loss of potassium (K) is a potential therapeutic strategy for
sickle cell (SS) disease. Dietary magnesium (Mg) pidolate supplementation over a
4-week period has been shown to inhibit K-Cl co-transport and reduce dehydration.
We report here the results in 17 of 20 patients with SS disease treated in an
open-label unblinded study of the effects of long-term (6 months) oral Mg
pidolate administration (540 mg Mg/d). A significant decrease (P < 0.0025) was
observed with Mg therapy in the distribution widths for red cell mean cell
haemoglobin concentration (MCHC) (haemoglobin distribution width; HDW),
reticulocyte mean cell volume (red cell distribution width of reticulocytes;
RDWr) and MCHC (reticulocyte HDW; HDWr), activity of red cell K-Cl co-transport,
Na/Mg exchanger and Ca2+-activated (Gardos) K+ channel, whereas red cell K and Mg
contents were significantly increased. Hb levels and absolute reticulocyte counts
did not change with Mg therapy. Two patients did not complete the trial because
of diarrhoea and one did not complete the trial for unrelated reasons. Although
the median number of painful days in a 6-month period decreased from 15 (range 0
60) in the year before the trial to 1 (range 0-18; P < 0.0005) during the period
of Mg therapy, no firm conclusion on therapeutic efficacy could be drawn from
this unblinded open-label trial.
PMID- 10691857
TI - Jamaican Sbeta+-thalassaemia: mutations and haematology.
AB - The sickling disorders are a common cause of morbidity and mortality in Jamaica.
Sickle cell beta+-thalassaemia is the fourth commonest form, occurring in one in
every 3000 births. This is a heterogeneous condition, producing HbS, HbF and HbA2
with variable amounts of HbA, depending on the mutation and, within a defined
population, only a few beta-thalassaemia mutations occur at high frequency. This
study establishes the frequency of beta-thalassaemia mutations in Sbeta+
thalassaemia patients in Jamaica. In addition, comparison of the haematological
phenotypes is possible by looking at the 'average steady-state haematology' of
the different mutational groups. Blood samples from 132 unrelated Sbeta+
thalassaemia patients attending the MRC Sickle Cell Unit at the University of the
West Indies were analysed by amplification refractory mutation system (ARMS)
polymerase chain reaction (PCR) or sequencing to determine the nature and
frequencies of the underlying beta-thalassaemia mutations. Ten mutations were
identified, four of which accounted for 93% of patients studied. These were -29(A
--> G) in 71 (54%), -88(C --> T) in 27 (20%), polyA(T --> C) in 17 (13%) and IVS1
5(G --> C) in nine (7%). The six remaining mutations found at low frequency were
C24(T --> A) in two patients and one each of IVS2-848(C --> A), -90(C --> T),
IVS1-5(G --> T), IVS1-5(G --> A) and IVS1-6 (T --> C). In one individual, no
mutation was found. The three commonest mutations were all associated with
haemoglobin levels of greater than 10 g/dl, whereas IVS1-5 (G --> C) had a more
severe haematological phenotype. The predominance of -29(A --> G) and -88(C -->
T) is in keeping with other studies on populations of African origin. IVS1-5(G -
> C) is found chiefly in Indian populations, and all affected families
acknowledged Indian ancestry, reflecting the prominent Indian community in
Jamaica.
PMID- 10691858
TI - Rapid detection of alpha-thalassaemia deletions and alpha-globin gene
triplication by multiplex polymerase chain reactions.
AB - We describe a sensitive, reliable and reproducible method, based on three
multiplex PCR assays, for the rapid detection of seven common alpha-thalassaemia
deletions and one alpha-globin gene triplication. The new assay detects the
alpha0 deletions - -SEA, - (alpha)20.5, - -MED, - -FIL and - -THAI in the first
multiplex PCR, the second multiplex detects the -alpha3.7 deletion and
alphaalphaalphaanti3.7 variant, the third multiplex detects the -alpha4.2
deletion. This simple multiplex method should greatly facilitate the genetic
screening and molecular diagnosis of these determinants in populations where
alpha-thalassaemias are prevalent.
PMID- 10691859
TI - Dyserythropoiesis associated with a fas-deficient condition in childhood.
AB - Defective lymphocyte apoptosis caused by mutations of the Fas gene can result in
an autoimmune lymphoproliferative syndrome (ALPS) in humans. We report two cases
of dyserythropoiesis associated with a Fas-deficient condition in childhood. In
both cases, dyserythropoiesis predominated on the more mature erythroblasts, and
was associated with a lymphoproliferative syndrome as well as with haemolytic
anaemia, hypergammaglobulinaemia and the expansion of an unusual population of
CD4- CD8- T cells that express the alpha/beta T-cell receptor. The regression of
dyserythropoiesis under steroid therapy suggested that it resulted from an
autoimmune mechanism, itself secondary to the lymphocyte Fas apoptosis
deficiency. Fas-defective apoptosis may be a new aetiology for childhood
dyserythropoiesis.
PMID- 10691860
TI - Safety profile of the oral iron chelator deferiprone: a multicentre study.
AB - In previous trials, the orally active iron chelator deferiprone (L1) has been
associated with sporadic agranulocytosis, milder forms of neutropenia and other
side-effects. To determine the incidence of these events, we performed a
multicentre prospective study of the chelator. Blood counts were performed
weekly, and confirmed neutropenia mandated discontinuation of therapy. Among 187
patients with thalassaemia major, the incidence of agranulocytosis (neutrophils <
0.5 x 109/l) was 0.6/100 patient-years, and the incidence of milder forms of
neutropenia (neutrophils 0.5-1.5 x 109/l) was 5.4/100 patient-years. All cases of
neutropenia resolved after interruption of therapy. Neutropenia occurred
predominantly in non-splenectomized patients. Nausea and/or vomiting occurred
early in therapy, was usually transient and caused discontinuation of deferiprone
in three patients. Mild to moderate joint pain and/or swelling did not require
permanent cessation of deferiprone and occurred more commonly in patients with
higher ferritin levels. Mean alanine transaminase (ALT) levels rose during
therapy. Increased ALT levels were generally transient and occurred more commonly
in patients with hepatitis C. Persistent changes in immunological studies were
infrequent, although sporadic abnormalities occurred commonly. Mean zinc levels
decreased during therapy. Ferritin levels did not change in the overall group but
decreased in those patients with baseline levels > 2500 microgram/l. This study
characterized the safety profile of deferiprone, and, under the specific
conditions of monitoring, demonstrated that agranulocytosis is less common than
previously predicted.
PMID- 10691861
TI - Excessive apoptosis of bone marrow erythroblasts in a patient with autoimmune
haemolytic anaemia with reticulocytopenia.
AB - We report a patient with autoimmune haemolytic anaemia (AIHA) with
reticulocytopenia, who showed excessive apoptosis of erythroblasts.
Ultrastructural analysis of bone marrow cells showed that 50% of erythroblasts
had characteristic features of apoptosis, which was confirmed by staining with
Annexin-V. In addition, in contrast to normal erythroblasts, Ig staining of the
entire erythroblast population could be shown. These data show that apoptosis may
contribute to the mechanism of reticulocytopenia in AIHA.
PMID- 10691862
TI - High FUS/TLS expression in acute myeloid leukaemia samples.
AB - Retinoic acid has the ability to induce differentiation in some myeloid leukaemia
cell lines and has been used to induce remission in acute promyelocytic leukaemia
patients. We have analysed changes in gene expression, by differential display,
in HL60 cells exposed to all-trans retinoic acid (ATRA) for only 1 h. Only about
0.4% of the genes examined by this technique showed changes in expression level,
and all four of the gene fragments identified were downregulated during the short
1 h exposure. Two of the fragments were novel, a third was MYC and the fourth was
the FUS proto-oncogene. Northern analysis showed that FUS was downregulated
within 1 h only during induced neutrophil differentiation but not at all during
induced monocyte differentiation. Unlike the sensitive cell lines, ATRA-resistant
cell lines did not show a downregulation of FUS over a 24 h period of exposure to
ATRA. Using a semiquantitative PCR analysis, no difference in FUS levels was
observed between ATRA-sensitive and -resistant cell lines. A similar analysis was
carried out on primary acute myeloid leukaemia (AML), peripheral stem cell
harvests (PBSC) and cord blood samples. The PBSC and cord blood samples had FUS
levels that were similar or generally less than the cell lines. However, much
higher levels were seen in 63% of the AML samples examined. The data presented
are consistent with previous reports for a role for FUS in the promotion and
maintenance of cellular proliferation.
PMID- 10691863
TI - Constitutive activation of FLT3 in acute myeloid leukaemia and its consequences
for growth of 32D cells.
AB - The receptor tyrosine kinase Flt3 is expressed on leukaemic blasts of most cases
with acute myeloid leukaemia (AML). In order to evaluate the presence and
significance of constitutive activation of Flt3 for leukaemogenesis, we (1)
analysed the expression and activation status of the receptor in AML blasts; and
(2) evaluated the functional consequences of constitutively active Flt3 in a
myeloid progenitor cell line. Immunoprecipitation studies revealed Flt3
expression in a high proportion of AML cases (27/32) with ligand-dependent Flt3
autophosphorylation in 18, constitutive autophosphorylation in three and no
autophosphorylation in six cases. Only one out of three samples with
constitutively active Flt3 but 3/18 samples with ligand-dependent
autophosphorylated Flt3 contained the recently described internal tandem repeat
(ITR) mutations. To test the significance of Flt3 activation in myeloid cell
function, we also characterized the biochemical and biological effects of the
activating mutation D838V of Flt3 (FLt3D838V) on the factor-dependent myeloid
progenitor cell line 32Dcl3: cells transfected with wild-type Flt3 (32D/Flt3)
grew FLt3 ligand (FL) dependent, and the receptor was ligand dependently
autophosphorylated. In contrast, the receptor was constitutively
autophosphorylated in 32D/Flt3D838V cells, which grew independently of FL. We
conclude that, in some AML samples, Flt3 is constitutively activated and that
this does not correlate with ITR mutations in the juxtamembrane domain.
Furthermore, constitutively active Flt3 confers factor independence to the
myeloid progenitor cell line 32D. It remains to be determined whether activation
of Flt3 is leukaemogenic in vivo and whether strategies aimed at inhibition of
Flt3 activation could inhibit leukaemogenesis.
PMID- 10691864
TI - Cell density-dependent VP-16 sensitivity of leukaemic cells is accompanied by the
translocation of topoisomerase IIalpha from the nucleus to the cytoplasm.
AB - The resistance of several leukaemic and myeloma cell lines (CCRF, L1210, HL-60,
KG-1a and RPMI 8226) to VP-16 was found to increase with cell density and to be
maximal (3.5- to 39-fold) in plateau phase cell cultures, as measured by
clonogenic and MTT assays. Non-transformed confluent Flow 2000 human fibroblasts
and Chinese hamster ovary (CHO) cells were also five- and 15-fold resistant to VP
16 respectively. The transition from log to plateau phase was accompanied by a
drastic decrease in topoisomerase (topo) IIalpha content in CHO cells and human
fibroblasts, while the leukaemic cells maintained constant cellular levels of
topo IIalpha and topo IIbeta. However, the nuclear topo IIalpha content was found
to decrease as a result of translocation of the enzyme to the cytoplasmic
compartment in the leukaemic cells. This was confirmed by subcellular
fractionation experiments, Western blotting analyses and immunocytochemistry
studies. The quantity of topo IIalpha in plateau phase cytoplasmic fractions
ranged from 18% in L1210 cells to 50% in HL-60 and 8226 cells, as measured by
both immunoblotting and quantification of the label in immunofluorescent images.
The cytoplasmic fraction from plateau phase cells retained topo II catalytic
activity, as measured by the decatenation of kinetoplast DNA. The nuclear
cytoplasmic ratio of topo IIalpha may be critical in determining the sensitivity
of leukaemic cells to topo II inhibitors. Cytoplasmic trafficking of topo IIalpha
was observed in plasma cells obtained from patients with multiple myeloma, and
perhaps contributes to drug resistance in this disease.
PMID- 10691865
TI - Incidence, characterization and prognostic significance of chromosomal
abnormalities in 640 patients with primary myelodysplastic syndromes. Grupo
Cooperativo Espanol de Citogenetica Hematologica.
AB - Recently, a consensus International Prognostic Scoring System (IPSS) for
predicting outcome and planning therapy in the myelodysplastic syndromes (MDS)
has been developed. However, the intermediate-risk cytogenetic subgroup defined
by the IPSS includes a miscellaneous number of different single abnormalities for
which real prognosis at present is uncertain. The main aims of this study were to
evaluate in an independent series the prognostic value of the IPSS and to
identify chromosomal abnormalities with a previously unrecognized good or poor
prognosis in 640 patients. In univariate analyses, cases with single 1q
abnormalities experienced poor survival, whereas those with trisomy 8 had a
higher risk of acute leukaemic transformation than the remaining patients (P =
0.004 and P = 0.009 respectively). Patients with single del(12p) had a similar
survival to patients with a normal karyotype and showed some trend for a better
survival than other cases belonging to the IPSS intermediate-risk cytogenetic
subgroup (P = 0.045). Multivariate analyses demonstrated that IPSS cytogenetic
prognostic subgroup, proportion of bone marrow blasts and haemoglobin level were
the main prognostic factors for survival, and the first two characteristics and
platelet count were the best predictors of acute leukaemic transformation risk. A
large international co-operative study should be carried out to clarify these
findings.
PMID- 10691866
TI - Cladribine with or without prednisone in the treatment of previously treated and
untreated B-cell chronic lymphocytic leukaemia - updated results of the
multicentre study of 378 patients.
AB - Between January 1992 and January 1999, we treated 378 B-chronic lymphocytic
leukaemia (CLL) patients with cladribine (2-CdA), and 255 of the patients were
also treated with prednisone. A total of 194 patients were previously untreated,
and 184 had relapsed or refractory disease after previous other therapy. Complete
response (CR) was obtained in 111 (29.4%) and partial response (PR) in 138
(36.5%) patients, giving an overall response (OR) rate of 65.9%. CR and OR were
achieved more frequently in patients in whom 2-CdA was a first-line treatment
(45.4% and 82.5% respectively) than in the pretreated group (12.5% and 48.4%
respectively) (P < 0.0001). The median duration of OR for previously untreated
patients was 14.7 months and for pretreated patients 13.5 months (P = 0.09). The
median survival evaluated from the beginning of 2-CdA treatment was shorter in
the pretreated group (16.3 months) than in the untreated group (19.4 months) (P <
0.0001). A total of 117 (63.9%) patients died in the pretreated group and 63
(32.6%) in the untreated group. In pretreated patients, 2-CdA + prednisone (P)
and 2-CdA alone resulted in similar OR (51.0% and 45.0% respectively; P = 0.4).
In contrast, in untreated patients, 2-CdA + P produced a higher OR (85.4%) than 2
CdA alone (72.1%) (P = 0.04). Infections and fever of unknown origin, observed in
91 (49.4%) pretreated and 74 (38.1%) untreated patients (P = 0.03), were the most
frequent toxic effects. Our results indicate that 2-CdA is an effective,
relatively well-tolerated drug, especially in previously untreated CLL.
PMID- 10691867
TI - The diagnosis of low-grade peripheral B-cell neoplasms in bone marrow trephines.
AB - The aim of this study was to establish how effective is the use of
immunohistochemistry on formalin-fixed bone marrow in diagnosing low-grade B-cell
neoplasms. We investigated a series of 41 consecutive patients with bone marrow
involvement for whom no other diagnostic tissues were available. The sections
were stained with the following antibodies: CD3, CD20, CD79a, CD5, CD10, CD23,
anti-cyclin D1 and kappa and lambda light chains. Antigen retrieval was performed
using either a microwave oven or a pressure cooker. Labelling was performed with
an avidin-biotin-peroxidase labelling system. A final diagnosis was reached in 37
out of 41 cases (90%): B-chronic lymphocytic leukaemia (15 cases), follicular
lymphoma (10 cases), mantle-cell lymphoma (eight cases) and lymphoplasmacytoid
lymphoma/immunocytoma (four cases). In the remaining four cases, a generic
diagnosis of low-grade B-cell neoplasm was made. The immunophenotyping of
formalin-fixed marrow is a useful technique for diagnosing most of the low-grade
B-cell neoplasms.
PMID- 10691868
TI - Recurrent B-cell non-Hodgkin's lymphoma in two brothers with X-linked
lymphoproliferative disease without evidence for Epstein-Barr virus infection.
AB - We present two male siblings suffering from recurrent manifestations of B-cell
non-Hodgkin's lymphoma (NHL) and recurrent infections of the lower respiratory
tract associated with bronchiectasis. Immunodeficiency could not be demonstrated
by any laboratory investigation. In both patients, lymphomas developed without
evidence for Epstein-Barr virus (EBV) infection, i.e. no antibody response to EBV
specific antigens, negative EBV-PCR (polymerase chain reaction) in peripheral
blood cells, and absence of latent membrane protein (LMP) and EBV-encoded RNA
(EBER) in lymphoma cells. Molecular analysis of the SH2D1A, the gene for X-linked
lymphoproliferative disease (XLP) led to the identification of a deletion in the
first exon in both patients. Therefore, we postulate that the genetic defect and
the following dysregulation of the B-/T-cell interaction rendered these patients
susceptible to the early onset of B-cell NHL and that EBV infection is not an
obligate prerequisite.
PMID- 10691869
TI - Human myeloma cells promote the production of interleukin 6 by primary human
osteoblasts.
AB - Interleukin-6 (IL-6) is an important growth and survival factor for myeloma
cells. However, the identity of the cells producing IL-6 in vivo remains unclear.
Myeloma cells are found closely associated with sites of active bone turnover,
and cells of the osteogenic lineage, including bone marrow osteoprogenitors,
osteoblasts and bone lining cells, may therefore be ideally placed to synthesize
IL-6. We have examined the possibility that human osteogenic cells may produce IL
6 in response to stimulation by myeloma cells. Primary human osteoblasts (hOBs)
were isolated from normal donors, co-cultured with the human myeloma cell lines,
JJN-3, RPMI-8226 and NCI-H929, and the amount of IL-6 released was determined by
enzyme-linked immunosorbent assay (ELISA). All myeloma cells stimulated a
significant increase in the production of IL-6 when cultured with hOBs (P <
0.05). Prior fixation of hOBs completely abrogated release of IL-6 in the co
cultures. In contrast, fixed myeloma cells retained the ability to induce IL-6
production, suggesting that hOBs were the principal source of IL-6. Physical
separation of myeloma cells from hOBs using transwell inserts caused a partial
inhibition of IL-6 release (P < 0.05), whereas the addition of media conditioned
by myeloma cells to cultures of hOBs stimulated a significant increase in IL-6
production (P < 0.05). hOBs secreted greater amounts of IL-6 than human bone
marrow stromal cells (hBMSCs) (2.2- to 3.5-fold, P < 0.05), but incubating hBMSCs
with dexamethasone to stimulate osteoblastic differentiation resulted in an
increase in their ability to produce IL-6 (1.7- to 4. 8-fold, P < 0.05) and to
respond to myeloma cells (P < 0.05). These data clearly indicate that cells of
the osteoblast lineage release significant amounts of IL-6 in response to
stimulation by myeloma cells and may contribute to the IL-6 that promotes the
proliferation and survival of myeloma cells in vivo.
PMID- 10691870
TI - Therapy with thalidomide in refractory multiple myeloma patients - the revival of
an old drug.
AB - We have treated 17 refractory or relapsed multiple myeloma patients resistant to
chemotherapy with thalidomide at a dose of 200-800 mg/day. Eleven patients
responded, five of whom had a very good partial response (> 75% decline in M
protein) and another five exhibited a partial response (> 50% decline in M
protein). Except for one patient, treatment was well tolerated with only mild
side-effects. Thalidomide should be included in the therapeutic options for
refractory myeloma.
PMID- 10691871
TI - Lamivudine allows completion of chemotherapy in lymphoma patients with hepatitis
B reactivation.
AB - Reactivation of hepatitis B virus in patients receiving chemotherapy for non
Hodgkin's lymphoma (NHL) may give rise to hepatitis, hepatic failure and death,
and prevent further chemotherapy. We report four patients with NHL in whom
hepatitis flare-up was observed after two (three patients) and six (one patient)
cycles of chemotherapy. After spontaneous recovery, they were treated with
Lamivudine (100 mg/day), which enabled completion of chemotherapy without further
hepatitis B reactivation. In one patient, high-dose chemotherapy and autologous
stem cell transplantation was also performed. These data suggest a possible role
for Lamivudine in preventing hepatitis B reactivation during chemotherapy
administration to chronic carriers of the hepatitis B virus. Moreover, it enabled
the completion of both standard and high-dose chemotherapy in patients with
previous hepatitis B reactivation.
PMID- 10691872
TI - T-prolymphocytic leukaemia with spontaneous remission.
AB - T-prolymphocytic leukaemia (T-PLL) is a rare dis-order with a poor prognosis. A
69-year-old man was diagnosed as having a small-cell variant of T-PLL according
to the French-American-British classification by haematological, immunological
and ultrastructural studies, although the cells had a CD7- phenotype and no
chromosomal abnormality. He had no symptoms or organomegaly. The number of his
lymphocytes, 53.7 x 109/l at the time of diagnosis, gradually decreased without
therapy, and he was in complete remission 39 months later. A rearranged band in
the T-cell antigen receptor-beta gene, which was detected at the time of
diagnosis, decreased or disappeared. This is the first report of a T-PLL case
with spontaneous complete remission.
PMID- 10691873
TI - Second allogeneic haematopoietic stem cell transplantation in relapsed acute and
chronic leukaemias for patients who underwent a first allogeneic bone marrow
transplantation: a survey of the Societe Francaise de Greffe de moelle (SFGM).
AB - Although recurrent malignancy is the most frequent indication for second stem
cell transplantation (2nd SCT), there are few reports that include sufficiently
large numbers of patients to enable prognostic factor analysis. This
retrospective study includes 150 patients who underwent a 2nd SCT for relapsed
acute myeloblastic leukaemia (n = 61), acute lymphoblastic leukaemia (n = 47) or
chronic myeloid leukaemia (n = 42) after a first allogeneic transplant (including
26 T-cell-depleted). The median interval between the first transplant and
relapse, and between relapse and second transplant was 17 months and 5 months
respectively. After the 2nd SCT, engraftment occurred in 93% of cases, 32% of
patients developed acute graft-vs.-host disease (GVHD) >/= grade II and 38%
chronic GVHD. The 5-year overall and disease-free survival were 32 +/- 8% and 30
+/- 8%, respectively, with a risk of relapse of 44 +/- 12% and a transplant
related mortality of 45 +/- 9%. In a multivariate analysis, five factors were
associated with a better outcome after 2nd SCT: age < 16 years at second
transplant; relapse occurring more than 12 months after the first transplant;
transplantation from a female donor; absence of acute GVHD; and the occurrence of
chronic GVHD. The best candidates for a second transplant are likely to be
patients with acute leukaemia in remission before transplant, in whom the HLA
identical donor was female and who relapsed more than 1 year after the first
transplant.
PMID- 10691874
TI - CD34+ cell dose predicts relapse and survival after T-cell-depleted HLA-identical
haematopoietic stem cell transplantation (HSCT) for haematological malignancies.
AB - Seventy-eight patients with haematological malignancies, received T-cell-depleted
stem cell transplants and cyclosporin followed by delayed add-back of donor
lymphocytes to prevent leukaemia relapse. The source of stem cells was bone
marrow in 50 patients and granulocyte colony-stimulating factor (G-CSF)-mobilized
peripheral blood in 28 patients. In univariate analysis, only the CD34+ cell dose
(but not the stem cell source or the T lymphocyte dose) and disease status were
predictive for transplant-related mortality, relapse and survival. Patients
receiving >/= 3 x 106 CD34+ cells/kg had an overall actuarial survival of 68%
compared with 52%, 35% and 10%, respectively, for cell doses of 2-2.99, 1-1.99
and < 1 x 106/kg. Multivariate analysis of risk factors for relapse identified
disease risk and CD34+ cell dose as the only factors. Relapse was 62.5% in 38
patients at high risk of relapse vs. 25% for 40 patients at intermediate or low
risk. CD34+ cell doses of >/= 3 x 106/kg were associated with a 13.5% relapse vs.
48% for recipients of lower doses. This favourable effect of CD34+ cell dose on
relapse was apparent in both high- and intermediate- plus low-risk groups. Our
results support the potential benefit of a high stem cell dose in lowering
transplant-related mortality (TRM) and in reducing relapse after allogeneic
marrow or blood stem cell transplants.
PMID- 10691875
TI - Reconstitution of the cellular immune response after autologous peripheral blood
stem cell transplantation in patients with non-Hodgkin's lymphoma.
AB - Peripheral blood stem cell (PBSC) transplants may be depleted of lymphoid
progenitors, thereby disabling the cellular immune response against viral
pathogens after autologous PBSC transplantation (PBSCT). To monitor the cellular
immune reconstitution after autologous PBSCT, we investigated the cytolytic
activity (CLA) of peripheral blood T lymphocytes against Epstein-Barr virus (EBV)
in 13 patients with non-Hodgkin's lymphoma or multiple myeloma. The individual
EBV-directed CLA (EBV-CLA) was determined by calculating the number of cytolytic
effector cells in 106 T cells needed to lyse 25% of autologous EBV-transformed B
lymphoblastoid cells, expressed as lytic units (LU25). During the first 6 months
after PBSCT, the EBV-CLA was only 14.6% of the response of healthy controls
(median 4. 8 vs. 32.9 LU25). Thereafter, the EBV-CLA increased to 28.15 LU25
(median) or 86% of healthy controls. Monthly follow-up analyses in five selected
patients showed that the EBV-CLA was barely detectable at 4 weeks and recovered
at 8-12 weeks after PBSCT in four out of five patients. Effector cells consisted
mostly of CD8-positive T lymphocytes, with small CD4- and CD3/CD56-positive
lymphocyte fractions. These results suggest that the reconstitution of the
cellular immune response against EBV takes 8-12 weeks after autologous PBSCT.
PMID- 10691876
TI - Incubation of murine bone marrow cells in hypoxia ensures the maintenance of
marrow-repopulating ability together with the expansion of committed progenitors.
AB - We developed previously a hypoxic culture system in which progenitors endowed
with marrow-repopulating ability (MRA), unlike committed progenitors, were
selected and maintained better than in air. We report here an improvement to this
system targeted at combining the maintenance of progenitors sustaining MRA with
the numerical expansion of multipotent and committed progenitors. Murine bone
marrow cells were incubated at 1% oxygen in liquid medium supplemented with stem
cell factor, granulocyte colony-stimulating factor, interleukin-6 and interleukin
3. In day 8 hypoxic cultures, the numbers of high proliferative potential and
granulocyte/macrophage colony-forming cells (HPP-CFC and CFU-GM) were increased
with respect to time zero. Colonies generated by HPP-CFC derived from hypoxic
cultures exhibited a high replating ability, whereas colonies generated by HPP
CFC derived from control cultures exhibited a low replating ability. MRA was
fully maintained in hypoxia and markedly reduced in air. Thus, severe hypoxia is
able to ensure a full maintenance of progenitors sustaining MRA, together with a
significant expansion of in vitro-detectable clonogenic progenitors, including
those endowed with replating ability. This system could contribute to the
improvement of current techniques for the in vitro treatment of human
haematopoietic cell populations before transplantation.
PMID- 10691877
TI - Induction of remission after donor leucocyte infusion for the treatment of
relapsed chronic idiopathic myelofibrosis following allogeneic transplantation:
evidence for a 'graft vs. myelofibrosis' effect.
AB - A 54-year-old man showed evidence of disease progression and a reduction in donor
chimaerism by molecular microsatellite analysis 6 months after an allogeneic
peripheral blood stem cell transplant for chronic idiopathic myelofibrosis. He
was treated with a single infusion of donor leucocyte infusions (DLI), which led
to the development of mild acute graft versus host disease (GVHD) and the rapid
restoration of full donor haemopoiesis. This subsequently led to a progressive
reduction in marrow fibrosis from grade IV to grade I over the following 6
months. We believe that this is the first report to provide clear evidence for
the efficacy of DLI in this setting, which also provides evidence for the
existence of a T-cell-mediated 'graft vs. myelofibrosis' effect similar to that
seen against other haematological malignancies.
PMID- 10691878
TI - A study of the iron and HFE status of blood donors, including a group who failed
the initial screen for anaemia.
AB - A complete data set (age, weight, diet and recent donation history; venous blood
cell count, serum ferritin and soluble transferrin receptor concentrations and
transferrin saturation; HFE genotype) was obtained from 113 male and 122 female
blood donors. Progressive iron depletion and deficiency - most apparent from
serum concentrations of soluble transferrin receptor divided by the logarithm of
ferritin concentrations (the TfR-F index) - developed in men donating up to six
times in 2 years, although the serum ferritin alone was also informative;
however, no prediction could be made for those iron-depleted individuals who will
develop iron deficiency after donation. Iron stores in the groups of donors with
'low-normal' haemoglobin (Hb) concentrations were indistinguishable from those in
donors with higher Hb values, whereas donors failing the anaemia screen had
reduced stores. This supports the UK policy of accepting donations from people
whose Hb concentration is up to 0. 5 g/dl below the recommended European
threshold. Women eating red meat once a week sustained higher ferritin
concentrations, and the iron status of first-time women donors resembled that of
men donating twice each year. Homozygosity for either HFE variant allowed greater
iron retention in the face of regular donation, but among heterozygotes the
findings were inconclusive.
PMID- 10691879
TI - A rapid one-stage whole-blood HPA-1a phenotyping assay using a recombinant
monoclonal IgG1 anti-HPA-1a.
AB - Severe neonatal alloimmune thrombocytopenia and patients with HPA-1a-specific
antibodies require transfusion of HPA-1a-negative platelets. Identifying HPA-1a
negative donors requires simple and reliable typing methods. Most existing
techniques use polyclonal antibodies, are time consuming and involve platelet
isolation. We have used a horseradish peroxidase (HRP)-conjugated recombinant
IgG1 anti-HPA-1a (CAMTRAN007) to develop a rapid and reliable enzyme-linked
immunosorbent assay (ELISA), which eliminates sample preparation and reduces the
incubation and wash steps associated with traditional sandwich ELISAs. The assay
uses simultaneous incubation of the monoclonal antibody RFGP56 to capture
GPIIbIIIa from whole blood and the recombinant IgG1 antibody to detect captured
HPA-1a antigen. It allows 96 samples to be typed in less than 1 h and can be used
on stored samples. Initial testing of 85 samples of known HPA-1a genotype
demonstrated that HPA-1a-negative samples had OD values of < 0.266, whereas HPA
1a-positive samples had OD values of > 0.6. Testing of 1862 random donor samples
in two blood centres confirmed these OD cut-off values and identified 45 HPA-1a
negative samples (2.4%), all except one giving OD values of < 0.2. The remaining
HPA-1a-negative sample had an OD value of 0.303. The HPA-1a status on all the
negative samples and an equivalent number of randomly selected positive samples
was confirmed by flow cytometry and polymerase chain reaction with sequence
specific primers (PCR- SSP).
PMID- 10691880
TI - New genotypes in Fy(a-b-) individuals: nonsense mutations (Trp to stop) in the
coding sequence of either FY A or FY B.
AB - Duffy blood group antigens are carried on a glycoprotein that is predicted to
pass through the erythrocyte membrane seven times and is a promiscuous chemokine
receptor. The Fy(a- b-) phenotype is present in two-thirds of African-American
Blacks but is rare in Caucasians. In Blacks, the phenotype is due to a non
functional GATA-1 motif in the FY B, which silences the gene in erythrocytes but
not in other tissues, and these patients do not generally make anti-Fyb or anti
Fy3. We describe here the molecular analysis of FY in three unrelated Caucasians
who were studied because they had strong anti-Fy3 in their serum. Each was found
to have a point mutation that was predicted to change a tryptophan to a premature
stop codon in the coding sequence. In one patient (patient 1), the nonsense
mutation was at nucleotide 287 of the major transcript in FY A; in another
(patient 2), it was at nucleotide 407 in the major transcript of FY B; and in a
third (patient 3), it was at nucleotide 408 of the major transcript of FY A.
PMID- 10691881
TI - Prevention of worsening of severe thrombocytopenia after red cell transfusions by
the use of leucocyte-depleted blood.
AB - Platelet counts were measured before and after red cell transfusions in 30
patients with anaemia and severe thrombocytopenia resulting from haematological
diseases. There was a mean reduction of 1.1 x 109/l (P = 0.43) in the platelet
count after transfusions of 2-3 units of leucocyte-depleted red cell concentrates
(20 patients). However, there was a mean reduction of 2.7 x 109/l (P = 0.03),
approximately 10%, in the platelet count after transfusions of non-leucocyte
depleted red cell concentrates (10 patients). The findings suggest that the
forthcoming introduction of universal leucocyte depletion of red cell
concentrates will minimize the worsening of thrombocytopenia that occurs in
severely thrombocytopenic patients receiving standard non-leucocyte-depleted red
cell concentrates.
PMID- 10691882
TI - Comparing near misses with actual mistransfusion events: a more accurate
reflection of transfusion errors.
AB - In a retrospective review of transfusion errors in a large teaching hospital, we
found the true incidence of errors to be at least four times the actual
mistransfusion events detected. Seventy-five per cent of the errors were detected
as near misses. The mistransfusions equated to 1/8610 compatibility procedures,
and 1/27 007 units of blood issued, whereas the number of true transfusion errors
equates to 1/2153 compatibility procedures and 1/6752 units of blood issued. The
major error-prone activities included patient identification at phlebotomy and
the final infusion of the blood product at the bedside. Of the cases, 95.2% were
due to non-compliance with existing guidelines. Potential disasters were avoided
only by the vigilance of the blood bank staff and the systems in place to detect
errors.
PMID- 10691883
TI - Changes in interferon-gamma production following specific allergen immunotherapy:
biology vs methodology.
PMID- 10691884
TI - Fibroblasts: a cell type central to eosinophil recruitment?
PMID- 10691885
TI - Immunoglobulin E and allergic disease in Africa.
PMID- 10691886
TI - Oilseed rape - allergen or irritant?
PMID- 10691887
TI - Airway inflammatory and antioxidant responses to oxidative and particulate air
pollutants - experimental exposure studies in humans.
PMID- 10691888
TI - gammadelta T cells in allergic airway diseases.
PMID- 10691889
TI - Complementary DNA cloning and expression of a newly recognized high molecular
mass allergen phl p 13 from timothy grass pollen (Phleum pratense).
AB - BACKGROUND: Grass pollen extracts contain a range of different allergenic
components that can be classified as having low, middle or high molecular mass.
Almost 75% of patients allergic to grass pollen display immunoglobulin (Ig) E
reactivity to allergens in the high molecular mass range of 55-60 kDa. These
proteins have not yet been fully characterized on the protein and DNA level.
OBJECTIVE: The aim of this study was to identify and characterize an allergen of
the high molecular mass fraction of Phleum pratense pollen by N-terminal protein
sequencing and molecular cloning. METHODS: A previously uncharacterized allergen
which migrates as a double band with a molecular mass of 55-60 kDa was
biochemically purified and investigated by N-terminal sequencing. Subsequently, a
DNA primer was designed to amplify the corresponding cDNA using PCR. The cloned
cDNA and deduced amino acid sequence were compared with sequence data bases.
Immunoblots carrying the recombinant expression product were developed with
monoclonal antibodies and sera derived from allergic subjects. The IgE-binding
capacity of natural and recombinant allergen was determined using EAST. RESULTS:
The nucleic acid sequence as well as the deduced amino acid sequence consisting
of 394 amino acids indicated homology with pollen specific polygalacturonases.
Four potential sites for glycosylation and 16 cysteine residues were found. The
recombinant expression product exhibited the same molecular size as the natural
allergen and was clearly IgE-reactive. CONCLUSION: The newly characterized
allergen Phl p 13, which shows homology with polygalacturonases, is clearly
different from the allergen designated as Phl p 4 and therefore the high
molecular mass fraction is composed of at least two different allergens. A
possible reason why this important allergen has not been detected until now is
that Phl p 13 and Phl p 4 are hardly separable by one dimensional SDS-PAGE.
PMID- 10691890
TI - Allergen-specific production of interferon-gamma by peripheral blood mononuclear
cells and CD8 T cells in allergic disease and following immunotherapy.
AB - BACKGROUND: CD8 T cells are important immunoregulatory cells in animal models of
allergic disease, but their role in human allergic immune responses has not been
defined. With the development of novel immunotherapeutic reagents, it is clearly
important to ascertain whether CD8 T-cell responses are altered following
conventional allergen-specific immunotherapy (SIT) and hence targets for future
developments/strategies. OBJECTIVE: To study the allergen-specific cytokine
release of freshly isolated CD8 T cells from the blood of separate groups of
house dust mite- (HDM) allergic patients, patients post-SIT and control nonatopic
donors. METHODS: CD8 T cells were isolated by positive selection with
immunomagnetic beads and cultured with the affinity purified major mite allergen
Der p 1 or with different mitogens, using irradiated autologous peripheral blood
mononuclear cells as antigen-presenting cells (APCs). Supernatants were collected
at a number of time points and assayed by ELISA for the cytokines interleukin
(IL) -4, IL-5 and interferon-gamma (IFNgamma). RESULTS: CD8 T cells stimulated
with Der p 1 produced significant quantities of IFNgamma with cells from HDM
allergic subjects releasing considerably more IFNgamma than cells from nonatopic
subjects, an average of 804 +/- 283 pg/mL of supernatant compared with 30.2 +/-
18.8 pg/mL (P = 0.006). The cytokine was detected in cultures of 16/17 of the
allergic subjects and 4/7 of the nonatopic. CD8 T cells from 6/10 patients who
had received HDM-SIT released IFNgamma at an average of 363 +/- 202 pg/mL, which
was less than the allergic group but still higher than the nonatopic (P = 0.05).
Equivalent levels of IFNgamma were detected when the cells were stimulated with
the mitogen PHA and this was the same in all groups. Reliable allergen-specific
release of significant quantities of IL-4 or IL-5 was not detected from CD8 T
cells. CONCLUSION: Allergen-specific IFNgamma is produced at far greater levels
from CD8 T cells of HDM-sensitive allergic patients than from nonatopic control
individuals and this level is reduced following SIT.
PMID- 10691891
TI - T-cell cytokine pattern at three time points during specific immunotherapy for
mite-sensitive asthma.
AB - BACKGROUND: Several lines of evidence indicate that specific immunotherapy may
act by modifying the patterns of cytokines produced by helper T cells. However,
different protocols have been used and different results obtained. OBJECTIVES: To
quantify the effect of specific immunotherapy on the TH1/TH2 T-cell cytokine
pattern at the single cell level. METHODS: We examined the interferon
gamma/interleukin-4 ratio in peripheral blood CD4+ and CD8+ T cells from 12
subjects with house dust mite-sensitive asthma using a flow cytometric method of
intracellular cytokine detection. Cytokine production was determined following
stimulation with phorbol myristate acetate/ionomycin, a policlonal activator.
Subjects were examined at three occasions: before specific immunotherapy, after
the 3-months dose increase phase and after 1 year of treatment. During the
treatment year patients kept a diary in which they recorded: (a) symptoms of
asthma according to a 0-3 grading (0 = absent, 1 = mild, 2 = moderate, 3 =
severe); (b) number of puffs (100 microg) per day of salbutamol required to
control symptoms; and (c) peak expiratory flow. RESULTS: Specific immunotherapy
improved clinical indices of disease activity including symptom scores and
medication use during the treatment year, and had a marked effect in increasing
the interferon-gamma/interleukin-4 ratio in peripheral blood CD4+ T cells already
after the dose increase phase (5.47 +/- 1.5 vs 4.07 +/- 1.49%, P = 0.03) with and
a further rise after 1 year's treatment (16.12 +/- 2.8 vs 4.07 +/- 1.49 and 16.12
+/- 2.8 vs 5.47 +/- 1.5%, P = 0.001 and P = 0.002, respectively). There were no
significant changes in the interferon-gamma/interleukin-4 ratio in peripheral
blood CD8+ T cells at the three times of the study. CONCLUSIONS: These data add
to view that the efficacy of specific immunotherapy may be attributed to a
modified cytokine secretion of CD4+ T cells.
PMID- 10691892
TI - Interleukin-13 and tumour necrosis factor-alpha synergistically induce eotaxin
production in human nasal fibroblasts.
AB - BACKGROUND: There is increasing evidence that eotaxin is a key mediator in the
development of tissue eosinophilia. However, the mechanism involved in the
production of eotaxin has yet to be clarified. Most recently, it has been shown
that interleukin (IL) -4 induces eotaxin in dermal fibroblasts. A novel cytokine
termed IL-13, which binds to the alpha-chain of the IL-4 receptor, shares many
biological activities with IL-4. It is known that fibroblasts express the IL-4
receptor and produce collagen type I upon stimulation with IL-4. OBJECTIVE: We
investigated whether IL-13, as well as IL-4, are able to induce eotaxin
production in human nasal mucosal fibroblasts (HNMFs). Furthermore, we
investigated the effect of costimulation of IL-13 and TNFalpha on eotaxin
production. METHODS: HNMFs, isolated from inferior nasal mucosa samples, were
stimulated by various kind of cytokines for 1-36 h at 37 degrees C in 5% CO2. The
change in the expression of eotaxin mRNA was then evaluated by reverse
transcriptase-polymerase chain reaction and the Southern blot analysis. The
amount of eotaxin in the culture media was measured by ELISA. RESULTS: IL-13 as
well as IL-4 dose-dependently induced eotaxin expression in HNMFs. Furthermore,
IL-13 and TNFalpha synergistically induced eotaxin expression in HNMFs, while
they hardly induced eotaxin expression in endothelial cells, epithelial cells or
eosinophils. The synergy was observed when pre-incubation of HNMFs with IL-13 was
followed by a stimulation with TNFalpha, or HNMFs were simultaneously stimulated
with IL-13 and TNFalpha. CONCLUSION: These results strongly indicate that IL-13,
as well as IL-4, may be important in eotaxin-mediated eosinophilic inflammation
in nasal mucosa. In addition, in nasal mucosa, fibroblasts are the major cell
source for eotaxin.
PMID- 10691893
TI - Total and specific IgE (house dust mite and intestinal helminths) in asthmatics
and controls from Gondar, Ethiopia.
AB - BACKGROUND: The role, if any, of parasitosis in the development of asthma remains
incompletely understood; both 'protective' and 'predictive' associations have
been reported. We report a study which examined immunoglobulin (Ig) E responses
to two common helminths in asthmatics living in Ethiopia. OBJECTIVE: To compare
the frequencies of specific IgE antibodies to Ascaris and Necator species and to
Der p 1 among 84 adult asthmatics and a referent group of nonasthmatics. METHODS:
A case-control analysis. RESULTS: Total IgE levels were not different between the
two groups. The presence of specific IgE to Der p 1 was strongly associated with
asthma (P = 0.001). Raised levels of Ascaris-(P = 0.010) and Necator- (P = 0.001)
specific IgE antibodies were more common among referents; there were no
associations between specific IgE production to Der p 1 and either of the two
parasites. CONCLUSION: These findings confirm the association between Der p 1
sensitization and asthma among urban, adult Ethiopians. While they also indicate
a negative relationship with two indicators of helminth infestation it appears
that this is not mediated through the immunological response to common
aeroallergens.
PMID- 10691894
TI - Detection of immunoglobulin antibodies in the sera of patients using purified
latex allergens.
AB - BACKGROUND: Latex allergy is largely an occupational allergy due to sensitization
to natural rubber latex allergens present in a number of health care and
household products. Although several purified allergens are currently available
for study, information on the usefulness of these purified, native or recombinant
allergens in the demonstration of specific immunoglobulin (Ig) E in the sera of
patients is lacking. OBJECTIVE: To evaluate the purified latex allergens and to
demonstrate specific IgE antibody in the sera of health care workers and spina
bifida patients with clinical latex allergy. METHODS: Two radioallergosorbent and
an enzyme-linked immunosorbent assay (ELISA) using latex proteins Hev b 1, 2, 3,
4, 6 and 7 along with two glove extracts and Malaysian nonammoniated latex (MNA)
were evaluated to demonstrate IgE in the sera of health care workers and spina
bifida with latex allergy and controls with no history of latex allergy. RESULTS:
ELISA using the purified latex allergens demonstrated specific IgE in 32-65%
health care workers and 54-100% of spina bifida patients with latex allergy. The
corresponding figures for RAST were 13-48 and 23-85 for RAST-1 and 19-61 and 36
57 for RAST-2. These results were comparable with the results obtained with glove
extracts and crude rubber latex proteins. CONCLUSIONS: When used simultaneously,
latex proteins Hev b 2 and Hev b 7 reacted significantly with specific serum IgE
in 80% of health care workers and 92% of spina bifida patients with latex allergy
by ELISA technique, while this combination gave lower positivity when the RASTs
were used. By the addition of Hev b 3, specific IgE was detected in all spina
bifida patients with latex allergy. Both RASTs failed to show specific IgE in the
control subjects, while the ELISA showed significant latex-specific IgE in 22% of
controls.
PMID- 10691896
TI - Indoor determinants of Der p 1 and Der f 1 concentrations in house dust are
different.
AB - BACKGROUND: Exposure to mite allergens is a major risk factor for sensitization
and the development of asthma. Der p 1 and Der f 1 content in homes and probably
the proportion of both antigens is highly variable even in the same geographical
area. OBJECTIVE: We investigated specific indoor determinants of Der p 1 and Der
f 1 concentrations in house dust of two German cities, Erfurt and Hamburg (n =
405 homes). METHODS: Mite allergen levels were determined using monoclonal
antibodies against Der p 1 and Der f 1 by the ELISA method. Indoor relative
humidity and temperature were monitored continuously in the homes over 1 week.
The characteristics of homes and occupants were assessed by questionnaire to
obtain information on factors which may have an impact on the mite antigen
concentration in house dust. These determinants were studied by multivariate
regression analysis. RESULTS: The correlation between concentrations of Der p 1
and Der f 1 inside the homes was weak (r = 0.29-0.35), indicating that different
determinants are relevant. Concentrations of the allergens were significantly
higher on lower floors (ratios 2-8 times, Der p 1, Der f 1), on old mattresses
(ratios 3-13 times, Der p 1, Der f 1), in post-war buildings (ratio 6 times, Der
p 1), for non-central heating (ratio 2 times, Der p 1), for old carpets (ratio 3
times, Der p 1) and for the presence of a dog in the house (ratio 3 times, Der f
1). Furthermore, mite concentration increases with raising relative humidity
(ratio 1.03 per 1%, Der p 1) and with decreasing temperature (ratio 0.86 per 1
degrees C, Der p 1) indoors. CONCLUSION: Both Der p 1 and Der f 1 concentrations
should be measured in house dust, since they are only weakly correlated and have
different determinants.
PMID- 10691895
TI - Sensitization to oilseed rape is not due to cross-reactivity with grass pollen.
AB - BACKGROUND: Oilseed rape is an important crop grown in the UK which can cause
specific immunological sensitization with clinical symptoms in a relatively small
number of the general population. Individuals with immunoglobulin (Ig) E-mediated
allergy to oilseed rape have also been found to be sensitized to other pollen
allergens, most frequently being grass pollen. Cross-reactivity between common
grass and oilseed rape would have important implications, especially as their
flowering period coincides. OBJECTIVE: We have investigated whether the
cosensitization found in individuals sensitized to both oilseed rape and grass
pollen is due to cross-reactivity. METHODS: Cross-reactivity between oilseed rape
and grass pollen was determined using RAST, RAST inhibition, Western blotting and
inhibition studies with Western blotting. RESULTS: Competitive RAST inhibition
studies between pollen of oilseed rape and grass failed to show any cross
reactivity between the pollen types. Self-inhibition with oilseed rape resulted
in 90% inhibition, whereas there was less than 10% inhibition with grass pollen.
Western blotting revealed allergens of similar molecular weight in both oilseed
rape and grass pollen. Despite allergens of similar molecular weights being
present in both pollen types, inhibition immunoblot studies confirmed that the
allergens in the two allergens were immunologically distinct. CONCLUSION: The
allergens of oilseed rape and grass pollen, although similar in molecular
weights, are immunologically distinct and there is no evidence of cross
reactivity between them. Individuals allergic to grass pollen will not
necessarily develop a specific nasal or airway response to inhaled oilseed rape
pollens.
PMID- 10691897
TI - The role of costimulatory molecules (B7-1 and B7-2) on allergen-stimulated B
cells in cedar pollinosis subjects.
AB - BACKGROUND: B7-1 (CD80) and B7-2 (CD86), which are costimulatory molecules in T
cell activation, play important roles in the differentiation of TH1- or TH2
phenotypes. These molecules were also suggested to play important roles in
sensitization to a cedar pollen antigen by blocking studies using neutralizing
antibodies, but there have been very few studies concerning the effects following
induction by antigen. OBJECTIVE: In this study, we investigated the roles of B7-1
and B7-2 in the differentiation of TH1 and TH2 subsets after stimulation with the
antigen in subjects with cedar pollinosis. METHODS: Skin-prick test was performed
in nine subjects with pollinosis and in nine normal controls. Peripheral blood
mononuclear cells (PBMCs) were isolated and stimulated with Japanese cedar pollen
extract. After in vitro stimulation, the expression of CD80 and CD86 on CD19+
cells was analysed by two-colour flow cytometry. Culture supernatants were
collected for all subjects and the production of type 1 and type 2 cytokines was
measured by ELISA. RESULTS: After in vitro stimulation, the expression of CD80
(B7-1) was upregulated in both pollinosis and control subjects, but no
significant difference was observed between the two groups. On the other hand,
CD86 (B7-2) was significantly upregulated following stimulation in pollinosis
subjects (P = 0.02). A significantly higher level of IL-5 (P = 0.04) was produced
by PBMCs of pollinosis subjects than by those of normal controls. A significantly
higher level of interferon (IFN)-gamma (P = 0.03) was produced by PBMCs of normal
controls than by those of pollinosis subjects. CONCLUSION: These results
indicated that TH2 response was predominant in pollinosis subjects, and that
CD19+ cells of pollinosis subjects expressed higher levels of B7-2 than those of
control subjects after in vitro stimulation. In pollinosis subjects, B7-2 rather
than B7-1 may be the costimulatory molecule involved in allergen-induced
activation of PBMCs.
PMID- 10691898
TI - Family patterns of asthma, atopy and airway hyperresponsiveness: an
epidemiological study.
AB - BACKGROUND: The patterns of inheritance of asthma have largely been explored
using data of symptom history collected by questionnaires which are subject to
bias and which may therefore distort the measured relationship. OBJECTIVE: The
purpose of this study was to examine family patterns of allergic disease using
objective measurements of atopy and of airway hyperresponsiveness (AHR). METHODS:
A large random sample of children aged 8-11 years was studied and 3 months later,
their parents were also invited for study. Of the sample of 1655 children, both
parents of 661 children were studied. In all subjects, respiratory illness
history was measured by questionnaire, atopy by skin tests and AHR by
responsiveness to histamine. RESULTS: The odds ratio for a child to have AHR if
either parent had the same condition was approximately 2. 0, which was the same
as the odds ratio for wheeze or diagnosed asthma in the presence of the same
condition in either parent. The odds ratio for atopy was smaller (approximately
1.4, NS) but the risk of a nonatopic child having AHR if the parent had AHR was
3.0 (P = 0.01). The correlation between weal size in the child and parent was
poor and the severity of AHR in the child was only modestly correlated with the
severity of AHR in the parent (R = 0.51, P = 0.04). CONCLUSION: The use of
objective measurements did not strengthen the association between atopic or
asthmatic conditions in the parent and child, but did suggest that atopy and AHR
are inherited independently.
PMID- 10691899
TI - Infant feeding patterns affect the subsequent immunological features in cow's
milk allergy.
AB - BACKGROUND: The first exposure to food antigens provokes an immune reaction in an
infant, its type depending on the quantity and frequency of doses and the age at
introduction, and also being influenced by genetic factors. Most infants develop
tolerance to food antigens, but in a small minority they provoke adverse
symptoms. OBJECTIVE: To study the effects of breast and formula feeding and other
environmental and genetic factors on the subsequent type of cow's milk allergy
classified by the presence or absence of immunoglobulin (Ig) E antibodies to
cow's milk. METHODS: A cohort of 6209 infants was followed prospectively from
birth for symptoms of cow's milk allergy. The infant-feeding regimen was recorded
at the maternity hospital and at home. At a mean age of 6.7 months, a total of
118 infants (1.9%) reacted adversely to a challenge with cow's milk. Before the
challenge, the response to a skin-prick test with cow's milk and serum IgE cow's
milk antibodies was measured. RESULTS: At challenge, 75 (64%) infants showed IgE
positive reactions to cow's milk, their most common symptom being acute-onset
urticaria. Significant risk factors for the presence of IgE cow's milk antibodies
in allergic infants were long breast-feeding (odds ratio [OR] 3.9, 95% confidence
interval [CI] 1.6-9.8), exposure to cow's milk at the maternity hospital (OR 3.5,
95% CI 1.2-10.1) and breast-feeding during the first 2 months at home either
exclusively (OR 5.1, 95% CI 1.6-16.4) or combined with infrequent exposure to
small amounts of cow's milk (OR 5.7, 95% CI 1.5-21.6). Fifty infants had their
first adverse symptoms during exclusive breast-feeding, and 32 infants were
sensitized during exclusive breast-feeding. Most of the infants in both cases
were IgE-positive: 37 and 23, respectively. CONCLUSIONS: In infants who are prone
to developing cow's milk allergy, prolonged breast-feeding exclusively or
combined with infrequent exposure to small amounts of cow's milk during the first
2 months of life induces development of IgE-mediated response to cow's milk.
PMID- 10691900
TI - Clinical relevance of food additives in adult patients with atopic dermatitis.
AB - BACKGROUND: Adverse reactions to food play an important role in the pathogenesis
of atopic dermatitis (AD). In infancy and childhood, food allergies are observed
in up to 30%, whereas nonallergic hypersensitivity reactions (pseudoallergic
reactions) towards food additives have been reported to occur between 2 and 7%.
By contrast, sensitizations towards food allergens are rarely of clinical
relevance in adults and little data is available on nonallergic hypersensitivity
reactions. To date the role of pseudoallergic reactions as an aggravating factor
in AD of adult patients remains controversial. However, many adult patients
report on food-related aggravation of the disease and nonallergic
hypersensitivity reactions have been incriminated repeatedly. OBJECTIVE: To
elucidate the relevance of food additives in adult patients suffering from AD.
METHODS: Fifty patients were monitored over 4 weeks under regular diet followed
by 6 weeks of a diet omitting known pseudoallergens. Skin status of patients was
assessed every 2 weeks by a standardized scoring, and serum eosinophilic cationic
protein (ECP) was determined before and after diet. RESULTS: Nine of fifty
patients dropped out, 26 showed a significant improvement of the Costa-score by
57%. In 23/26 patients a corresponding reduction of serum ECP level by 52% on
average was determined. Responder patients (24/26) were orally challenged with
food rich in pseudoallergens followed by double-blind exposure to food additives
(n = 15). A worsening of the eczema was seen in 19/24 patients after intake of
pseudoallergen-rich food and in 6/15 patients after exposure to food additives.
CONCLUSION: These results indicate that a subgroup of adult patients with AD
clinically improve on low-pseudoallergen diet but only a small subgroup respond
to oral provocation with food additives.
PMID- 10691901
TI - Late asthmatic reaction with airway inflammation but without airway
hyperresponsiveness.
PMID- 10691902
TI - Window pane condensation and high indoor vapour contribution - markers of an
unhealthy indoor climate?
AB - OBJECTIVE: The aim of this study was to investigate whether window pane
condensation and indoor vapour contribution >/= 3 g/m3 could be used as
indicators of defective air change rate, high indoor humidity and high mite
allergen concentration in mattress dust. METHODS: Actual ventilation rate, indoor
temperature, air humidity (AIH/RH) and concentrations of mite allergen were
measured in 59 houses and compared with received outdoor temperatures and air
humidity. Indoor vapour contribution defined as the difference between the indoor
and the outdoor vapour concentration was calculated. Sensitivity, specificity,
predictive values and accuracy were calculated for window pane condensation and
high vapour contribution (>/= 3 g/m3), as indicators of defective ventilation (<
0.5 ACH), high indoor humidity (>/= 7 g/kg and >/= 45% RH) and high mite allergen
concentration in mattress dust (>/= 2 microg/g). RESULTS: All houses with high
humidity and high mite allergen concentrations were positive for the two
indicators (high sensitivity), but with a specificity of only 50% so that half of
the houses with reported condensation and high vapour contribution turned out to
be low pollution houses with adequate high ventilation levels. Both indicators
had high negative predictive values and absence of the two indicators almost
certainly (97-100%) excluded high indoor pollution with high humidity and high
mite concentrations. Overall more than 70% of the dwellings were correctly
classified by the two indicators. CONCLUSION: Absence of window pane condensation
on double-glazed windows and low indoor vapour contribution (< 3 g/m3) during the
winter are true markers of a dwelling without high indoor air humidity and
without high mite allergen concentrations in mattress dust in houses in a cold
temperate climate with subzero outdoor temperatures. The presence of the two
indicators is associated with a 18-45% risk of high humidity and mite allergen
concentrations so in this latter group further measurements are needed for
correct classification.
PMID- 10691903
TI - Airborne endotoxin exposure and the development of airway antigen-specific
allergic responses.
AB - BACKGROUND AND OBJECTIVE: Repeated exposure of aerosolized antigen via
respiratory tract can induce immunoglobulin (Ig) E isotype-specific tolerance to
this antigen. However, the atopic individuals often produce a higher titre of IgE
in response to airborne environmental allergens. The mechanisms of this
differential regulation of airway allergen-specific immune responses are not
fully understood. This study investigated the role of airborne endotoxin on the
initiation of antigen-specific airway allergic responses. METHODS: ELISA methods
for detection of isotypes of antigen-specific antibodies and competitive reverse
transcription polymerase chain reaction for detection mRNA of cytokines were
used. In addition, Liu stain method was used to analyse the amounts of
eosinophils in bronchoalveolar lavage fluid. RESULTS: Mice pre-exposed with
airborne endotoxin mounted significantly higher amounts of OVA-specific IgE
antibody responses to inhaled OVA than those OVA-only sensitized mice. Inhaled
endotoxin could downregulate repeated airway antigen exposure-induced IgE isotype
specific tolerance and increase antigen-induced lung eosinophils infiltration.
CONCLUSIONS: These data show that airborne endotoxin exposure could potentiate
allergen-specific airway inflammation. The results should have potential
implications for understanding the development of allergen-induced airway
allergic responses.
PMID- 10691904
TI - Altered in vitro apoptosis of cultured mast cells prepared from an inbred strain
of mice, NC/Kuj.
AB - BACKGROUND: An inbred strain of mice, NC, develops dermatitis associated with
highly elevated serum IgE and dermal mast cell hyperplasia. OBJECTIVES AND
METHODS: To clarify the mechanisms for the dermal mast cell hyperplasia in NC, we
prepared bone marrow-derived mast cells (BMMCs) from three strains of mice,
NC/Kuj, C57BL/6 and BALB/c, and compare histamine contents, histamine release
abilities, adhesive properties and apoptosis of the BMMCs. RESULTS: Compared with
BMMCs obtained from C57BL/6 and BALB/c, NC/Kuj BMMC possessed higher histamine
content and higher adhesive ability to plastic plates, although histamine release
from BMMCs was found to be similar in the three strains. The most intriguing
finding is the lack of apoptosis in the BMMCs from NC/Kuj upon growth factor
deprivation as determined by DNA ladder formation and loss of membrane
phospholipid asymmetry. CONCLUSION: The altered in vitro properties of mast cells
in NC/Kuj partially account for an increase of dermal mast cells, which might be
involved in the development of skin lesions in NC.
PMID- 10691905
TI - Bronchoprotective effects of atrial natriuretic peptide against propranolol
induced bronchoconstriction after allergic reaction in guinea pigs.
AB - OBJECTIVE: To study the effects of intravenous atrial natriuretic peptide (ANP)
on antigen-induced bronchoconstriction, propranolol-induced bronchoconstriction
(PIB) after antigen challenge, and histamine-induced bronchoconstriction in
guinea pigs. METHODS: Allergic bronchoconstriction was evoked by inhalation of
ovalbumin (OA) and PIB was caused when 10 mg/mL of propranolol was inhaled 20 min
after OA challenge in passively sensitized and artificially ventilated guinea
pigs. 25, 50, 100 and 200 microg/mL of histamine were inhaled for 20 s at 5-min
intervals in non-sensitized guinea pigs. RESULTS: Pretreatment with ANP in doses
of 0.1 and 1.0 nmol/kg injected intravenously 15 min after antigen challenge
reduced PIB in a dose-dependent manner, and 5 min before antigen challenge
significantly attenuated PIB but not antigen-induced bronchoconstriction.
Intravenous ANP significantly reduced bronchial responses to increasing
concentrations of inhaled histamine in a dose-dependent manner. CONCLUSION: These
results suggest that ANP possesses protective effects against propranolol-induced
and histamine-induced bronchoconstriction, albeit by a non-specific mechanism in
guinea pig in vivo.
PMID- 10691906
TI - Possible mechanism of bronchoprotection by SIN-1 in anaesthetized guinea pigs:
roles of nitric oxide and peroxynitrite.
AB - BACKGROUND: S-morpholinosydnonimine (SIN-1) is thought to generate peroxynitrite.
Recent reports suggested that peroxynitrite possessed a potent vascular relaxant
activity via guanylate cyclase activation. However, no previous studies have
examined the relaxant effect of peroxynitrite on airway smooth muscle. OBJECTIVE:
To determine the mechanism of bronchoprotection by SIN-1, considering in
particular the involvement of nitric oxide (NO) and peroxynitrite. METHODS:
Peroxynitrite formation was assayed by monitoring the oxidizing activity of
dihydrorhodamine 123, and NO was measured polarographically as a redox current in
vitro. We examined the effect of SIN-1 delivered to the airway by ultrasonic
nebulization against bronchoconstriction induced by acetylcholine in
anaesthetized guinea pigs. RESULTS: SIN-1 produced peroxynitrite in a time- and
concentration-dependent manner, but did not produce NO in vitro. However, when
mixed with glutathione (GSH) and bronchoalveolar lavage fluid (BALF),
peroxynitrite formation by SIN-1 was inhibited and SIN-1 induced the release of
NO. SNAP (S-nitroso-N-acetyl-penicillamine) and SIN-1 each inhibited
acetylcholine-induced bronchoconstriction in a dose-dependent manner in vivo.
Though GSH alone did not have any effect on baseline airway resistance and
acetylcholine-induced bronchoconstriction, pretreatment with GSH significantly
enhanced SNAP- and SIN-1-induced bronchoprotection. In addition, pretreatment
with carboxy-PTIO, a NO scavenger, completely inhibited bronchoprotective effect
of SNAP on acetylcholine-induced bronchoconstriction, but partially inhibited SIN
1-induced bronchoprotection. CONCLUSION: These findings demonstrated that SIN-1
is a potent peroxynitrite-releasing compound and caused significant
bronchoprotection against acetylcholine. The mechanism of bronchoprotection by
SIN-1 appears to be mediated by peroxynitrite but also at least in part through
NO regeneration, which may involve GSH and airway thiols as a consequence of
exposure to peroxynitrite.
PMID- 10691907
TI - Early B cell defects.
PMID- 10691908
TI - Clonal expansion of T cells infiltrating in the airways of non-atopic asthmatics.
AB - CD4+ T cells are thought to play an important role in airway inflammation in both
atopic and non-atopic asthma. However, the mechanism by which T cells are
activated in non-atopic asthma, where there is no causative antigen identified,
is unknown. To elucidate this issue, we analysed T cell receptor (TCR) Vbeta gene
clonotypes of T cells in the bronchoalveolar lavage fluids (BALF) of non-atopic
asthmatics using polymerase chain reaction single-strand conformation
polymorphism (PCR-SSCP) analysis and a sequencing method. We found that the
numbers of TCR Vbeta gene clonotypes of T cells in the BALF of non-atopic
asthmatics were significantly increased compared with those of peripheral blood
lymphocytes (PBL). We also found that there were several shared amino acid motifs
in complementarity-determining region 3 (CDR3) of TCR Vbeta genes from those T
cell clones in BALF of non-atopic asthmatics, whereas these shared motifs were
not found in the same Vbeta family genes from PBL in the patients. Moreover, a
conserved amino acid sequence was detected in two patients who shared a common
HLA-DR allele. These results indicate that the infiltrating T cells in the
airways of non-atopic asthmatics recognize relatively limited epitopes of
antigens and are clonally expanded by antigen-driven stimulation.
PMID- 10691909
TI - Targeted Fc2'-3-PE40 chimeric protein abolishes passive cutaneous anaphylaxis in
mice.
AB - The alarming increase in the incidence of allergic diseases in the past decade
has led to a clear call for more effective treatment. Recently, we reported on
the construction of a chimeric protein for targeted elimination of cells
expressing FcepsilonRI receptors. This chimeric protein, designated Fc2'-3-PE40,
is composed of a Fc fragment of mouse IgE attached to a truncated form of
Pseudomonas exotoxin. The Fc2'-3-PE40 chimeric protein was found to be highly
cytotoxic to mouse mast cell lines and primary mouse mast cells. We now
demonstrate that Fc2'-3-PE40 successfully prevents the development of passive
cutaneous anaphylaxis reaction (PCA) in mice. Treatment with Fc2'-3-PE40 for 7
days prevented the PCA reaction in mice by 80% compared with that in control mice
given only PBS. Fc2'-3-PE40M, the mutated, enzymatically inactive analogue of
Fc2'-3-PE40, did not display this activity. Fc2'-3-PE40 was also effective when
given as a single dose 16 h before antigen exposure, resulting in complete
inhibition of the PCA reaction. Moreover, treatment with Fc2'-3-PE40 did not
cause mast cell degranulation, as the serum histamine values of mice treated with
Fc2'-3-PE40 were within the range obtained for control, untreated mice. Thus, the
Fc2'-3-PE40 chimeric protein offers a novel approach to the treatment of allergic
disorders.
PMID- 10691910
TI - CD4-CD8- T cells bearing invariant Valpha24JalphaQ TCR alpha-chain are decreased
in patients with atopic diseases.
AB - Atopic disorders are caused by disregulated activation of T helper 2 (Th2) cells
that produce IL-4 and IL-5. Because the presence of IL-4 potently augments the
differentiation of naive T cells into Th2 cells, it is important to seek the cell
population which provides IL-4 for naive T cells. Recently, a unique
subpopulation of T cells, natural killer (NK) T cells, has been shown to produce
a large amount of IL-4 upon activation, suggesting their regulatory role in
initiation of Th2 cell differentiation. To determine whether NK T cells play a
regulatory role in human Th2 cell-mediated atopic diseases, we analysed the
frequency of invariant Valpha24JalphaQ CD4-CD8- double-negative (DN) T cells,
human NK T cells, in patients with atopic asthma and atopic dermatitis. We also
studied cytokine production from Valpha24+ Vbeta11+ DN T cells, which comprise
most of Valpha24JalphaQ DN T cells. We found that the invariant Valpha24JalphaQ
DN T cells were greatly diminished in patients with asthma and atopic dermatitis.
On the other hand, there was no significant difference in Valpha24+ CD4+ T cells
possessing invariant Valpha24JalphaQ TCR between healthy subjects and atopic
patients. We also found that Valpha24+ Vbeta11+ DN T cells from healthy subjects
predominantly produced interferon-gamma (IFN-gamma) but not IL-4 upon activation.
These results suggest that NK T cells may not be essential for human atopic
disease and that the disappearance of NK T cells, most of which produce IFN
gamma, may be involved in the pathogenesis of atopic diseases.
PMID- 10691911
TI - Interferon-alpha (IFN-alpha) stimulates anti-melanoma cytotoxic T lymphocyte
(CTL) generation in mixed lymphocyte tumour cultures (MLTC).
AB - IFN-alpha administration after primary tumour resection improves the survival of
melanoma patients at high risk of relapse. To investigate whether this response
might be due to stimulation of anti-tumour immunity, the effect of IFN-alpha on
anti-melanoma CTL generation in MLTC was measured. IFN-alpha increased both
allogeneic and autologous anti-melanoma CTL generation from peripheral blood
lymphocytes stimulated with irradiated primary melanoma cultures. IFN-alpha up
regulated MHC class I expression on primary melanoma cultures, whereas IFN-gamma
up-regulated both MHC class I and II expression. However, the effect of IFN-alpha
on anti-melanoma CTL generation was often more potent than that of IFN-gamma,
equalling the effect of the optimal combination of IL-2 and IL-12. Pre-treatment
of primary melanoma cultures with IFN-gamma was sufficient for CTL generation in
MLTC, whereas IFN-alpha needed to be present during the MLTC. While direct anti
proliferative effects of IFN-alpha on some tumour cells have been described, IFN
alpha did not inhibit proliferation of primary melanoma cultures. These results
suggest that the clinical effects of IFN-alpha in melanoma patients may be immune
mediated.
PMID- 10691912
TI - Autoimmunity to glutamic acid decarboxylase in patients with autoimmune
polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED).
AB - Antibodies to glutamic acid decarboxylase (GAD) occur frequently in patients with
APECED, although clinical insulin-dependent diabetes mellitus (IDDM) is seen only
in a subgroup of the patients. We studied the cellular immunity to GAD,
antibodies to GAD and their association with the HLA DQB1 risk alleles for IDDM
in patients with APECED. Proliferation responses to GAD were enhanced in the
patients with APECED when compared with the control subjects (P = 0.004), but
autoimmunity to GAD was not associated with IDDM in APECED. The levels of
interferon-gamma (IFN-gamma) secreted by GAD-stimulated T cells were higher in
the patients than in control subjects (P = 0. 001). A negative correlation (r = -
0.436, P = 0.03) existed between the antibody levels and the stimulation indices
(SIs) to GAD. In 14 non-diabetic patients no difference in insulin secretion was
observed in intravenous glucose tolerance test (IVGTT) between the patients with
and without T cell reactivity to GAD. We conclude that cellular immunity to GAD
detected as T cell proliferation response to GAD or IFN-gamma secretion by GAD
stimulated T cells was frequent in patients with APECED (69%) and was not
restricted to the patients with clinically detectable beta-cell damage.
PMID- 10691913
TI - IL-10 enhances IL-2-induced proliferation and cytotoxicity by human intestinal
lymphocytes.
AB - IL-10 modulation of human intestinal T lymphocyte functions was studied for the
first time. Lymphocyte proliferation was determined by 3H-thymidine
incorporation; cytokine production, by ELISA; expression of surface markers, by
immunofluorescence and flow cytometric analysis; and cytotoxicity, by lysis of
51Cr-labelled target cells. IL-10 blocked phytohaemagglutinin (PHA)-induced
activation and proliferation of CD8+ T cells from the epithelium and lamina
propria. It was a greater inhibitor of IL-2, interferon-gamma, and tumour
necrosis factor-alpha production than were IL-4 or transforming growth factor
beta. In contrast, IL-10 enhanced IL-2-stimulated proliferation of both CD4+ and
CD8+ T cells by increasing cell division after activation. It also augmented IL-2
but not IL-15-induced cytotoxicity of intestinal lymphocytes against colon
cancer by a mechanism independent of natural killer cells. In conclusion, IL-10
blocking of proinflammatory cytokine secretion probably reduces intestinal
inflammation. IL-10 augmentation of IL-2-induced cytotoxicity may help to
maintain host defence.
PMID- 10691914
TI - Proliferative responses of blood mononuclear cells (BMNC) in a cohort of elderly
humans: role of lymphocyte phenotype and cytokine production.
AB - Age-related impaired T cell function is associated with increased mortality risk.
The purpose of the present study was therefore to identify factors associated
with the age-related decreased phytohaemagglutinin (PHA)-induced proliferative
response of lymphocytes in a cohort of 174 81-year-old humans and in 91 young
controls. Decreased proliferation was associated with a reduced number of true
naive CD4+ cells (CD62L+CD45RO-). Furthermore, a low IL-2-stimulated
proliferation was correlated with a decreased PHA response in the elderly cohort,
whereas reciprocal interactions of IL-10- and IL-2-producing cells were of
importance in both elderly and young subjects. Accordingly, a minimum of true
naive CD4+ cells was required for a normal proliferative response to PHA, perhaps
by providing sufficient IL-2 which is critical for growth of naive as well as
memory cells.
PMID- 10691915
TI - Prednisolone inhibits cytokine-induced adhesive and cytotoxic interactions
between endothelial cells and neutrophils in vitro.
AB - We assessed whether prednisolone influenced the ability of human
polymorphonuclear neutrophils (PMN) to adhere to and cause lysis of human
umbilical vein endothelial cells (HUVEC) in vitro (as measured by the release of
51Cr). Pretreatment of the endothelium with IL-1beta or tumour necrosis factor
alpha (TNF-alpha) caused prominent endothelial E-selectin expression and
endothelial hyperadhesiveness for neutrophils, as well as PMN-mediated
cytotoxicity. All these processes were dose-dependently reduced when prednisolone
was added to the assay system. This protective effect remained when HUVEC alone
were pretreated with the drug prior to washing and cytokine activation. Likewise,
when HUVEC cytotoxicity was induced by the nitric oxide (NO) donor S-nitroso
acetyl-penicillamine (SNAP), prednisolone reduced cell injury significantly. In
contrast, prednisolone did not interfere with signalling systems between TNF
alpha-stimulated HUVEC and quiescent PMN such as IL-8 generation and release of
cytosolic Ca2 + in the PMN. Thus, in this in vitro model of vasculitis,
prednisolone dose-dependently reduced cytokine-induced E-selectin expression and
HUVEC hyperadhesiveness for neutrophils, as well as reducing neutrophil-dependent
cytotoxicity against HUVEC via NO-dependent steps.
PMID- 10691916
TI - PPD-specific IgG1 antibody subclass upregulate tumour necrosis factor expression
in PPD-stimulated monocytes: possible link with disease pathogenesis in
tuberculosis.
AB - Cachexia is a prominent feature of advanced tuberculosis, in association with
increased expression of the monokine tumour necrosis factor (TNF)-alpha.
Monocytes, have high affinity receptors (mannose, complement and Fc gamma1 and
gamma111) which mediate antigen uptake and subsequent cytokine activation.
Several mycobacterial proteins, including PPD, can stimulate TNF-alpha secretion
from monocytes. However, the role of various receptors in stimulating or
regulating TNF-alpha secretion is still unclear. We have previously shown
selective augmentation of opsonic antibodies (IgG1 and IgG3) in tuberculosis
patients with advanced pulmonary disease. We now analyse the role of opsonizing
antibodies in modulating TNF-alpha expression in antigen stimulated monocytes.
PPD was used as the prototypic mycobacterial antigen to stimulate monocytes from
PPD skin test negative donors (n = 7) in the presence of plasma from tuberculosis
patients (n = 8), containing known amounts of IgG1 and IgG3 anti-PPD antibodies.
TNF-alpha secretion was enhanced in the presence of TB plasma (4/8) but not in
the presence of control plasma. Using Spearman Rank analysis (two-tailed Fisher
exact test), a significant correlation (rho = 0.762; P = 0. 04) was observed
between IgG1 antibodies and enhancement of TNF-alpha secretion. No significant
association was observed with IgG2 (rho = 0.310; P = 0.41), IgG3 (rho = 0.089; P
= 0.81) or IgG4 (rho = - 0.357; P = 0.347) subclass antibodies. Absorption of
IgG1 with protein 'A' removed the enhancement of TNF-alpha secretion activity
from the plasma samples. Our results therefore indicate that IgG1 antibodies may
enhance the chronic release of TNF-alpha in TB patients with progressive disease
and, for the first time, show a direct link between disease pathogenesis and
raised antibody levels.
PMID- 10691917
TI - Bacteroides fragilis enterotoxin induces the expression of IL-8 and transforming
growth factor-beta (TGF-beta) by human colonic epithelial cells.
AB - Bacteroides fragilis toxin (BFT) has been shown to be capable of inducing
intestinal mucosal inflammation in animals. Such inflammation may be responsible
for diarrhoea, which occurs in some, but not all human carriers of
enterotoxigenic strains of B. fragilis (ETBF). We have studied responses to BFT
by different human intestinal epithelial cell lines and subsequently investigated
the expression of IL-8 and TGF-beta by T84 cells. The latter were selected
because their responses to BFT, characterized by morphological changes and cell
death by apoptosis, were similar to those we have recently observed in primary
human colonocytes. We show that BFT dose-dependently increased the expression of
transcripts and protein of the polymorphonuclear cell chemoattractant IL-8. BFT
also dose-dependently induced the release of TGF-beta, which has been shown to
enhance the repair of the injured intestinal epithelium. However, the secreted
TGF-beta was almost exclusively in the biologically inactive form, as determined
by Mv1Lu bioassay. Our studies therefore suggest that exposure of colonic
epithelial cells in vivo to high concentrations of BFT can initiate an
inflammatory response via secreted IL-8. BFT-induced release of latent TGF-beta
may facilitate the subsequent repair of the injured epithelium, following its
activation by proteases from neighbouring cells. Variation in cytokine responses
by colonic epithelial cells in vivo could be an important determinant in the
development of mucosal disease and symptoms in response to ETBF.
PMID- 10691918
TI - Expression of HLA-DR, costimulatory molecules B7-1, B7-2, intercellular adhesion
molecule-1 (ICAM-1) and Fas ligand (FasL) on gastric epithelial cells in
Helicobacter pylori gastritis; influence of H. pylori eradication.
AB - There is evidence that Helicobacter pylori infection up-regulates the expression
of HLA class II molecules by gastric epithelial cells (GEC). In this study we
evaluated whether GEC are capable of expression of costimulatory molecules in H.
pylori gastritis. The expression of FasL by GEC, before and after eradication of
H. pylori, was also studied. Thirty patients (23 men) aged 27-81 years (53.67 +/-
13.99 years (mean +/- s.d.)) with dyspepsia were studied. Upper gastrointestinal
endoscopy was performed and six biopsies were obtained (antrum, n = 3; corpus, n
= 3) for Campylobacter-Like Organisms (CLO) test and histology; 23 (16 men) were
H. pylori+ and seven (all men) were H. pylori- by both methods and served as
controls. Helicobacter pylori eradication therapy was given to H. pylori+
patients and all patients were re-endoscoped after 116 +/- 9 days. Formalin-fixed
paraffin-embedded tissue sections were stained by the ABC immunoalkaline
phosphatase method. In H. pylori gastritis HLA-DR was expressed and correlated
with disease activity (P < 0.01). No HLA-DR was observed in controls. In H.
pylori-eradicated patients significant decrease of HLA-DR was found (antrum, P <
0. 001). ICAM-1 was expressed by GEC in 80% of H. pylori+ patients; ICAM-1
expression did not correlate with gastritis parameters and decreased
significantly after eradication (antrum, P < 0.01). B7-1 and B7-2 were expressed
on H. pylori+ samples and their expression decreased after eradication, albeit
not significantly. Weak epithelial expression of both B7 molecules was observed
in all the controls. FasL was steadily expressed by GEC in both H. pylori+ and H.
pylori- patients and remained almost unchanged after eradication. These findings
suggest that GEC may acquire antigen-presenting cell properties in H. pylori
infection through de novo expression of HLA-DR and costimulatory molecules. This
seems to be attenuated after eradication and resolution of mucosal inflammation.
The same cells exhibit the capacity to control the inflammatory process, probably
by inducing apoptotic cell death to Fas-bearing infiltrating lymphocytes.
PMID- 10691919
TI - Mechanisms of the in vitro fungicidal effects of human neutrophils against
Penicillium marneffei induced by granulocyte-macrophage colony-stimulating factor
(GM-CSF).
AB - We examined the in vitro fungicidal activity of human neutrophils against conidia
and yeast cells of Penicillium marneffei. Neutrophils showed a small but
significant anti-fungal effect against the yeast form of P. marneffei. Treatment
of neutrophils with GM-CSF significantly augmented their anti-fungal activity. In
contrast, the conidia form resisted killing even by stimulated neutrophils.
Neutrophil fungicidal effect was not inhibited by superoxide dismutase (SOD),
while the same treatment significantly suppressed the killing of Candida albicans
by GM-CSF-stimulated neutrophils. For effective killing of P. marneffei yeast
cells by GM-CSF-stimulated neutrophils, direct contact between the two was
essential; interference in such interaction by separation using a 0. 45-microm
pored membrane prevented such an effect. Addition of colchicine attenuated GM-CSF
stimulated neutrophil fungicidal activity in a dose-dependent manner. This effect
did not appear to be mediated by interference with neutrophil mobility toward
yeast cells, because similar results were obtained when the cultures were set in
round-bottomed wells which facilitate their direct contact. Finally, granular
extracts derived from unstimulated neutrophils significantly suppressed the
growth of microorganisms. Pretreatment of neutrophils with GM-CSF markedly
enhanced this effect. The fungicidal activity of granular lysates was strongly,
but not completely, reduced by heat treatment. Considered together, our results
indicate that GM-CSF-stimulated neutrophils killed the yeast form of P. marneffei
present in close proximity, probably in a superoxide anion-independent mechanism,
but through exocytosis of granular enzymes which were largely heat-labile.
PMID- 10691920
TI - Interferons and interferon (IFN)-inducible protein 10 during highly active anti
retroviral therapy (HAART)-possible immunosuppressive role of IFN-alpha in HIV
infection.
AB - Interferons play an important, but incompletely understood role in HIV-related
disease. We investigated the effect of HAART on plasma levels of IFN-alpha, IFN
gamma, neopterin and interferon-inducible protein 10 (IP-10) in 41 HIV-infected
patients during 78 weeks of therapy. At baseline HIV-infected patients had raised
levels of both IP-10 and IFN-alpha compared with healthy controls (n = 19), with
particularly high levels in advanced disease. HAART induced a marked decrease in
levels of both IFN-alpha, neopterin and IP-10, though not to normal
concentrations. In contrast, IFN-gamma levels were low throughout the study, and
not different from controls. While neopterin and IP-10 remained significantly
decreased compared with baseline levels throughout the study, IFN-alpha levels
returned to baseline at the end of the study. Persistently high IP-10 and IFN
alpha levels were associated with immunological treatment failure and even high
baseline levels of IFN-alpha appeared to predict immunological relapse.
Furthermore, we found a markedly suppressive effect of exogenously added IFN
alpha on phytohaemagglutinin-stimulated lymphocyte proliferation in both patients
and controls, and this suppressive effect seemed not to involve enhanced
lymphocyte apoptosis. Our findings suggest a pathogenic role of IFN-alpha in HIV
infection, which may be a potential target for immunomodulating therapy in
combination with HAART.
PMID- 10691921
TI - HIV-1 co-receptor expression on trophoblastic cells from early placentas and
permissivity to infection by several HIV-1 primary isolates.
AB - We examined CD4 and major HIV-1 co-receptor expression by trophoblast cells (TC)
from early placentas, and the permissiveness of TC for infection by several
natural HIV-1 isolates in vitro. Ten early placentas (4-6 weeks of gestation)
from HIV- women were obtained after elective abortion. CD4 and HIV-1 co-receptor
expression by TC was examined in terms of both mRNA and protein. The same TC were
then challenged with three clinical HIV isolates of known phenotype, two
originating from mothers who transmitted the virus to their child and one from a
vertically infected newborn. TC infection was detected by polymerase chain
reaction. CD4 expression was detected in five of the 10 placentas, while membrane
protein expression of CCR3, CXCR4 and CCR5 was detected in every case, despite
quantitative differences among individuals. Bonzo, GPR1 and ChemR23 mRNAs were
detected in all TC preparations. TC from seven out of eight placentas were
permissive to HIV entry, but no productive viral replication was detected
(reverse transcriptase activity in culture supernatants). Interestingly, the
addition of chemokine(s) or a CD4-blocking antibody to the cultures failed to
inhibit TC virus entry. These data point to marked interindividual variability in
HIV co-receptor expression by trophoblast cells and show that TC from early
placentas can be infected in vitro by clinical HIV-1 isolates. They also suggest
that viral entry in vitro might occur through a mechanism independent of both CD4
and chemokine receptors.
PMID- 10691922
TI - CD4+ and CD8+ T lymphocyte regeneration after anti-retroviral therapy in HIV-1
infected children and adult patients.
AB - Previous studies have shown a slow recovery of naive CD4+ T cell counts after
anti-retroviral therapy in HIV-1-infected adults, which is in accordance with
thymus atrophy after puberty. Here we investigate whether or not different
patterns of naive CD4+ and CD8+ T cell repopulation are present in adult and
child patients undergoing anti-retroviral treatment. Thus, 25 adults under highly
active anti-retroviral therapy and 10 children under combined anti-retroviral
therapy were retrospectively analysed for T cell subpopulations at baseline (T0)
and around week 12 (T1) and week 24 (T2) of anti-retroviral treatment. Mean serum
HIV-1 RNA levels dropped in both groups. Recovery of T cells in adults was
characterized by a heterogeneous response between patients, with only 44% of them
increasing their naive CD4+ and CD8+ T cell counts at T1, and changes in mean
total CD4+ T cells were mainly shaped by memory cells. Otherwise, children were
characterized by an early increase in naive T cells. Thus, at T1, all children
analysed had a strong rise in CD4+ (from 389 +/- 116 to 569 +/- 121 cells/microl;
P < 0.01), and nine out of 10 also in naive CD8+ T cells (from 244 +/- 58 to 473
+/- 85 cells/microl; P < 0.05). However, no significant correlation between age
and naive repopulation was observed (P = 0. 22) in children. Thus, children had
the earlier and greater increases in naive T cell subsets than adults, probably
due to a more active thymus, with the potential for immune reconstitution when
HIV-1 replication is controlled.
PMID- 10691923
TI - CD28 costimulation and CD28 expression in T lymphocyte subsets in HIV-1 infection
with and without progression to AIDS.
AB - In a prospective study of 152 HIV-1 patients (with and without progression to
AIDS) we examined CD28 MoAb costimulation and CD3 MoAb response using whole blood
culture at baseline and up to either the time of AIDS diagnosis or the end of the
observation period. CD28 antigen expression on both CD4+ and CD8+ T lymphocytes
was also studied in both groups of patients. In patients who progressed to AIDS,
CD28 MoAb costimulation was found to be decreased. Univariate time-dependent
analysis showed that decreases in (i) absolute numbers of either CD4+, CD4+CD28+,
CD8+CD28+ T cells, (ii) CD28 MoAb costimulation, and (iii) CD3 MoAb response, and
an increase in CD8+CD28- %, are significant predictors for progression to AIDS.
In addition, multivariate time-dependent analysis demonstrated that a decrease in
CD28 MoAb costimulation (but not a decrease in CD3 MoAb response) was predictive
for progression to AIDS, as were decreases in the percentage of CD4+ T cells and
the absolute number of CD4+CD28+ T cells. Thus, CD28 MoAb costimulation can be
considered a useful assay for monitoring HIV-1 infection. Furthermore, apart from
the early increase in the percentage of CD8+CD28- T cells and an increase in the
percentage of CD28- on CD8+ T cells in both groups of patients at baseline
compared with normal controls, a negative correlation was found to exist between
the percentages of CD4+ or CD4+CD28+ T cells and the percentage of CD8+CD28- T
cells; this suggests that these cells are probably mutually regulated.
PMID- 10691924
TI - Trypanosoma cruzi-induced immunosuppression: B cells undergo spontaneous
apoptosis and lipopolysaccharide (LPS) arrests their proliferation during acute
infection.
AB - Acute infection with Trypanosoma cruzi is characterized by multiple
manifestations of immunosuppression of both cellular and humoral responses. B
cells isolated at the acute stage of infection have shown marked impairment in
their response to polyclonal activators in vitro. The present work aims at
studying the B cell compartment in the context of acute T. cruzi infection to
provide evidence for B cell activation, spontaneous apoptosis and arrest of the
cell cycle upon mitogenic stimulation as a mechanism underlying B cell
hyporesponse. We found that B cells from acutely infected mice, which fail to
respond to the mitogen LPS, showed spontaneous proliferation and production of
IgM, indicating a high level of B cell activation. Furthermore, these activated B
cells also exhibited an increase in Fas expression and apoptosis in cultures
without an exogenous stimulus. On the other hand, B cells from early acute and
chronic infected mice did not present activation or apoptosis, and were able to
respond properly to the mitogen. Upon in vitro stimulation with LPS, B cells from
hyporesponder mice failed to progress through the cell cycle (G0/G1 arrest), nor
did they increase the levels of apoptosis. These results indicate that B cell
apoptosis and cell cycle arrest could be the mechanisms that control intense B
cell expansion, but at the same time could be delaying the emergence of a
specific immune response against the parasite.
PMID- 10691925
TI - Cross-reactivity of anti-galactocerebroside autoantibodies with a Trypanosoma
brucei proteolipidic epitope.
AB - Pathogenic mechanisms of the demyelinating encephalopathy featuring the nervous
phase of human African trypanosomiasis (HAT) are largely unknown. They might
include autoimmune disorders. A variety of autoantibodies is detected during the
disease and we have previously evidenced anti-galactocerebroside (GalC)
antibodies in the serum and cerebrospinal fluid (CSF) from patients in the
nervous stage (stage II) of HAT. We now show that anti-GalC antibodies recognize
an antigen located on the parasite membrane and common to different strains of
trypanosomes. By using affinity chromatography with a rabbit anti-GalC antiserum,
a 52-kD proteolipid was isolated from the membrane of Trypanosoma brucei (T. b.)
brucei AnTat 1.9, AnTat 1. 1E, and T. b. rhodesiense Etat 1.2/R and Etat 1.2/S.
Antibodies directed against this antigen were found in the CSF from patients with
nervous stage HAT. These CSF also contained anti-GalC antibodies and adsorption
with the proteolipid decreased anti-GalC reactivity. Immunization of mice with
this antigen induced the production of antibodies which cross-reacted with GalC
but no protection from experimental infection with T. b. brucei. These data
support the hypothesis that anti-GalC antibodies detected in the CSF from HAT
patients might be induced by molecular mimicry with a parasite antigen.
PMID- 10691926
TI - The development of post-kala-azar dermal leishmaniasis (PKDL) is associated with
acquisition of Leishmania reactivity by peripheral blood mononuclear cells
(PBMC).
AB - PKDL develops in about 50% of Sudanese patients treated for visceral
leishmaniasis (kala-azar). Patients with kala-azar were entered into this study
and followed for a period of up to 2 years. During follow up 12 patients
developed PKDL and eight did not. Proliferative responses and cytokine production
to Leishmania donovani and control antigens were measured in vitro using PBMC
isolated at the time of diagnosis of kala-azar, after treatment of visceral
leishmaniasis, during follow up, and at the time of diagnosis of PKDL.
Proliferative responses and interferon-gamma (IFN-gamma) production were low at
diagnosis and increased after treatment of kala-azar in both patients who
developed (group 1) and those who did not develop PKDL later (group 2). In group
1, development of PKDL was always associated by an increased PBMC response to
Leishmania antigen in proliferation and IFN-gamma production assays. There were
no differences in Leishmania antigen-induced production of IL-4, IL-5 and IL-10
between or within the two groups. We have previously shown that Leishmania
parasites spread to the skin during visceral leishmaniasis and proposed that PKDL
was the result of an immunological attack on parasites, which have survived in
the skin despite the drug treatment. The finding that PKDL develops after
treatment of kala-azar as Leishmania-reactive T cells start to circulate in
peripheral blood in sufficient numbers to be detected in in vitro assays supports
this hypothesis.
PMID- 10691927
TI - Autoantibodies to DEK oncoprotein in systemic lupus erythematosus (SLE).
AB - Autoantibodies against the transcriptional DEK protein have been considered
characteristic of the pauciarticular onset subtype of juvenile rheumatoid
arthritis (JRA) associated with iridocyclitis in young girls. In this study we
investigated the presence of anti-DEK autoantibodies in the sera of 288 patients
with SLE using a recombinant DEK protein as autoantigenic target. Thirty sera
(10.4%) were positive against DEK protein by immunoblotting. Patients with anti
DEK autoantibodies show a lower frequency of cutaneous manifestation, exhibit
more frequently certain markers of a chronic inflammatory status like anaemia and
positivity for C-reactive protein, as well as a higher frequency of anti-double
stranded DNA autoantibodies. In contrast to JRA patients positive for anti-DEK
autoantibodies, no association with erosive arthritis nor iridocyclitis were
found in SLE. In conclusion, our results show that 10.4% of SLE patients from our
area show antibodies against DEK protein, although this feature did not clearly
establish a clinical subset of the disease.
PMID- 10691928
TI - Human monoclonal anti-phospholipid antibodies selectively bind to membrane
phospholipid and beta2-glycoprotein I (beta2-GPI) on apoptotic cells.
AB - The ability of an anti-phospholipid (LJ1) and an anti-beta2-GPI (RSP-57) human
MoAb to bind to apoptotic but not viable cells was demonstrated in this study.
Both MoAbs were derived from patients with systemic lupus erythematosus and anti
phospholipid antibody syndrome. The parallel analysis of the specificity and
affinity of four anti-phospholipid human MoAbs suggests that the binding of LJ1
MoAb to apoptotic cells is a specific property of this MoAb. RSP-57 MoAb
recognizes apoptotic cells through beta2-GPI which becomes available for binding
after the interaction with negatively charged phospholipids. This observation
provides evidence that the binding of human anti-phospholipid antibodies to
apoptotic cells occurs in both a beta2-GPI-dependent and independent way and
involves a restricted group of epitopes. The finding that LJ1 and RSP-57 MoAbs
bind apoptotic cells underlines the property of these MoAbs to act as cell
membrane markers of apoptosis. Major pathological implications derive from the
observation that LJ1 and RSP-57 MoAbs recognize epitopes expressed on 'early'
apoptotic cells. The interference with the in vivo clearance and processing of
apoptotic cells is a potential pathogenic mechanism of these antibodies.
PMID- 10691929
TI - In the rheumatoid pannus, anti-filaggrin autoantibodies are produced by local
plasma cells and constitute a higher proportion of IgG than in synovial fluid and
serum.
AB - IgG anti-filaggrin autoantibodies (AFA) are the most specific serological markers
of rheumatoid arthritis (RA). They include the so-called 'anti-keratin
antibodies' (AKA) and anti-perinuclear factor (APF), and recognize human
epidermal filaggrin and other (pro)filaggrin-related proteins of various
epithelial tissues. In this study we demonstrate that AFA are produced in
rheumatoid synovial joints. In 31 RA patients, AFA levels were assayed at equal
IgG concentrations in paired synovial fluids (SF) and sera. AFA titre-like values
determined by indirect immunofluorescence and immunoblotting and AFA
concentrations determined by ELISA were non-significantly different in serum and
SF, clearly indicating that AFA are not concentrated in SF. In contrast, we
demonstrated that AFA are enriched in RA synovial membranes, since the ELISA
determined AFA in low ionic-strength extracts of synovial tissue from four RA
patients represented a 7.5-fold higher proportion of total IgG than in paired
sera. When small synovial tissue explants from RA patients were cultured for a
period of 5 weeks, the profile of IgG and AFA released in the culture
supernatants was first consistent with passive diffusion of the tissue
infiltrating IgG (including AFA) over the first day of culture, then with a de
novo synthesis of IgG and AFA. Therefore, AFA-secreting plasma cells are present
in the synovial tissue of RA patients and AFA can represent a significant
proportion of the IgG secreted within the rheumatoid pannus.
PMID- 10691930
TI - PERB11 (MIC): a polymorphic MHC gene is expressed in skin and single nucleotide
polymorphisms are associated with psoriasis.
AB - The susceptibility genes for psoriasis remain to be identified. At least one of
these must be in the major histocompatibility complex (MHC) to explain
associations with alleles at human leucocyte antigen (HLA)-A, -B, -C, -DR, -DQ
and C4. In fact, most of these alleles are components of just two ancestral
haplotypes (AHs) designated 13.1 and 57.1. Although relevant MHC gene(s) could be
within a region of at least 4 Mb, most studies have favoured the area near HLA-B
and -C. This region contains a large number of non-HLA genes, many of which are
duplicated and polymorphic. Members of one such gene family, PERB11.1 and
PERB11.2, are expressed in the skin and are encoded in the region between tumour
necrosis factor and HLA-B. To investigate the relationship of PERB11.1 alleles to
psoriasis, sequence based typing was performed on 97 patients classified
according to age of onset and family history. The frequency of the PERB11.1*06
allele is 44% in type I psoriasis but only 7% in controls (Pc = 0.003 by Fisher's
exact test, two-tailed). The major determinant of this association is a single
nucleotide polymorphism (SNP) within intron 4. In normal and affected skin,
expression of PERB11 is mainly in the basal layer of the epidermis including
ducts and follicles. PERB11 is also present in the upper keratin layers but there
is relative deficiency in the intermediate layers. These findings suggest a
possible role for PERB11 and other MHC genes in the pathogenesis of psoriasis.
PMID- 10691931
TI - Cytomegalovirus immune globulin intravenous (human) administration modulates
immune response to alloantigens in sensitized renal transplant candidates.
AB - One of the important parameters for prolonged waiting time for potential renal
transplant recipients is the presence of preformed antibodies to human leucocyte
antigen (HLA) antigens, which is often caused by previous transplants, pregnancy
or transfusions. In vivo administration of specific and unselected polyclonal
intravenous immunoglobulin (IVIGs) preparations have been shown to inhibit anti
HLA alloantibodies in highly sensitized patients. We sought to determine whether
Cytogam (Medimmune Inc., Gaithersburg, MD, USA), a hyperimmune
anticytomegalovirus immunoglobulin would (1) effect either in vitro or in vivo
alloreactivity, and (2) whether Cytogam therapy could reduce the titre of
preformed anti-HLA antibodies in highly sensitized patients. Alloreactivity was
assessed by mixed lymphocyte reaction (MLR) and cytotoxic T lymphocyte (CTL)
assay. A complement dependent microlymphocytotoxicity assay was done to assess
for panel reactive antibody (PRA) status and the presence of anti-idiotypic
antibodies in the Cytogam preparation. The MLR was inhibited by Cytogam in vitro
in a dose-dependent fashion ranging from 31-92%. Significant inhibition of the
MLR responses was not observed in recipients who received Cytogam in vivo (50
mg/kg). This could be a result of adminstration of a low dose of IVIG. However,
CTL activity against the alloantigens in all individuals assessed was
significantly inhibited after in vivo administration of Cytogam. Three of five
individuals experienced a decrease of 5-32% in the PRA status at 4 weeks post
administration of Cytogam. Cytogam also blocked the anti-HLA antibody titres in a
microlymphocytotoxicity assay, suggesting the presence of anti-idiotypic
antibodies. Our study was based on a single prophylactic dose of Cytogam (50
mg/kg), however, higher dose administration could be feasible by removing more
fluid at dialysis, but should be given intradialytically to avoid volume
overload. Overall, our results suggest that Cytogam can modulate the in vivo and
in vitro T cell responses against the alloantigens.
PMID- 10691932
TI - Staphylococcal acid phosphatase binds to endothelial cells via charge
interaction; a pathogenic role in Wegener's granulomatosis?
AB - The majority of patients with Wegener's granulomatosis (WG) are chronic nasal
carriers of Staphylococcus aureus. Chronic nasal carriage of S. aureus is
associated with an increased risk of developing a relapse of the disease. The
mechanism by which this occurs is still unknown. We hypothesized that a cationic
protein of S. aureus, staphylococcal acid phosphatase (SAcP), acts as a planted
antigen and initiates glomerulonephritis and vasculitis in patients with WG. In
order to test the hypothesis that SAcP can act as a planted antigen in WG, we
studied the ability of SAcP to bind to human umbilical vein endothelial cells
(HUVEC) and human glomerular endothelial cells. We also studied whether this
binding can be prevented by preincubation with an anionic protein, and whether
binding of SAcP activates endothelial cells. We also evaluated whether antibodies
in sera of patients with WG are able to bind to endothelial cell-bound SAcP. The
results show that SAcP can act as a planted antigen by binding to both types of
endothelial cells in a concentration-dependent manner. Binding of concentrations
as low as 4 microg/ml can be detected on HUVEC within 5 min of incubation.
Binding of SAcP to endothelial cells was charge-dependent but did not activate
endothelial cells. Finally, endothelial cell-bound SAcP was recognized by sera of
patients with WG. The data suggest a possible pathogenic role for SAcP by acting
as a planted antigen thereby initiating glomerulonephritis and vasculitis in
patients with WG.
PMID- 10691933
TI - Neutrophil FcgammaRIIIb allelic polymorphism in anti-neutrophil cytoplasmic
antibody (ANCA)-positive systemic vasculitis.
AB - Neutrophils constitutively express FcgammaRIIa and FcgammaRIIIb receptors. Both
receptors exhibit allelic variants which have different quantitative functional
capacities: the biallelic FcgammaRIIa-R131 and -H131 alleles, and the neutrophil
antigen (NA) NA1/NA2 alleles. ANCA activation of neutrophils requires ligation of
FcgammaRIIa receptor, but recent data have shown that ANCA can also bind
FcgammaRIIIb receptor. The aim of this study was to determine whether the
FcgammaRIIIb polymorphism was a risk factor for the development of ANCA
associated systemic vasculitis, or the associated nephritis. FcgammaRIIIb
receptor genotyping was determined by allele-specific polymerase chain reaction.
Genomic DNA was extracted from 101 Caucasian patients with ANCA+ vasculitis (of
whom 84 had renal disease) and 100 ethnically matched controls. Of the patients
with ANCA+ systemic vasculitis, 71 had ANCA with specificity for proteinase 3 and
30 with specificity for myeloperoxidase (MPO). Overall no significant difference
in genotype distribution or allele frequencies was found between patients and
controls, or between patients with renal disease and controls. However, there was
a trend for an increase in homozygosity for the NA1 allele in patients with a
vasculitis and this was significant in patients who had anti-MPO antibodies. The
FcgammaRIIIb receptor polymorphism is not a major factor predisposing to the
development of ANCA+ systemic vasculitis or the associated nephritis. The over
representation of the FcgammaRIIIb homozygous NA1 allele in patients with anti
MPO antibodies may have implications for disease susceptibility.
PMID- 10691934
TI - History of dermabrasion.
PMID- 10691935
TI - Laser skin resurfacing of the face with a combined CO2/Er:YAG laser.
AB - BACKGROUND: A combined, dual-wavelength CO2/Er:YAG laser system having the
ability to deliver both clean ablation of skin with the erbium wavelength and a
simultaneous deeper penetrating subablative thermal pulse of CO2 was developed
for full-face resurfacing. The CO2 component can be pulsed from 1 to 100 msec at
a power of 1-10 W with the Er:YAG component pulsed at 350 microsec at 1.7 J/cm2
through either a computer pattern generator with 3 mm diameter spot size or
through a noncollimated spot ranging from 0.2 to 8 mm in diameter. Our previous
study using this laser on the neck using a 4-8 mm diameter spot with Er:YAG
fluence at 1.7 J and the CO2 at 5 W with a 50 msec pulse at a frequency of 10 Hz
showed a higher degree of overall patient satisfaction, as well as improvement in
skin texture and skin color, compared to patients treated with an Er:YAG laser
alone. OBJECTIVE: This study evaluated the CO2/Er:YAG laser treatment modality in
facial resurfacing. METHODS: Ten patients were treated with four passes at 1.7 J
with a 4 mm diameter spot and the CO2 at 5 W with a 50-msec pulse at a frequency
of 10 Hz. Photoaging scores as well as thermal damage and new collagen formation
were compared immediately before and after treatment as well as at 2 weeks and 3
months postoperatively. RESULTS: The average pretreatment periorbital score was
6.2 The average posttreatment periorbital scores were 4.2 (P =.0239) at 2 weeks
postoperatively (32% improvement) and 3.8 (P =.0028) at 3 months postoperatively
(38% improvement). The average pretreatment perioral score was 5.9. The average
posttreatment perioral scores were 3.0 (P =.0001) at 2 weeks postoperatively (49%
improvement) and 3.3 (P =.0009) at 3 months postoperatively (44% improvement).
The average pretreatment cheek score was 4.7. The average posttreatment cheek
scores were 2.7 (P =.0066) at 2 weeks postoperatively (43% improvement) and 3.8
(P =. 0152) at 3 months postoperatively (36% improvement). The average
pretreatment forehead score was 4.7. The average posttreatment forehead scores
were 3.8 (P =.0340) at 2 weeks postoperatively (33% improvement) and 3.6 (P
=.0147) at 3 months postoperatively (37% improvement). The average depth of
collagen measured in the dermis pretreatment was 29 microm. The average depth of
collagen 3 months posttreatment was 54 microm. This is an average increase of 25
microm or an 86% increase in collagen (P =.006). The average thermal damage
immediately after treatment was 20 microm. CONCLUSION: The CO2/Er:YAG laser
utilized with four passes at the above-mentioned parameters results in a similar
degree of improvement as other forms of laser resurfacing with high-energy, short
pulsed CO2 lasers.
PMID- 10691936
TI - Sclerotherapy for treatment of hemangiomas.
AB - BACKGROUND: While sclerotherapy in chronic venous insufficiency and in
hemorrhoids is well established, the use of sclerotherapy for hemangiomas of the
skin is widely unknown. OBJECTIVE: The aim of the study was to analyze the
clinical value of sclerotherapy with polidocanol in a larger population. METHODS:
Over a period of 20 years (1975-1995) we performed sclerotherapy of hemangiomas
and vascular malformations in a total of 157 patients. Their ages ranged from 3
months to 75 years. Among these were 87 (55.4%) children and adolescents (up to
the age of 18). Sclerotherapy with polidocanol was carried out mostly at
monstrous or rapidly growing cavernous hemangiomas mainly localized in the face.
RESULTS: One to three injections was usually sufficient to obtain the sclerosis
effect; aesthetically, long-term results were convincing. Severe complications
were not observed. CONCLUSION: Sclerotherapy of hemangiomas is a relatively
simple, effective, and inexpensive method that is a valuable and promising
treatment.
PMID- 10691937
TI - Evaluation of a long-pulse Q-switched Nd:YAG laser for hair removal.
AB - BACKGROUND: Hirsutism and hypertrichosis are common problems for which a
permanent solution has been elusive. Laser-assisted hair removal is a promising
technique. However, the optimal wavelength, pulse duration, and fluence continue
to require further investigation. OBJECTIVE: To determine if the long-pulse Q
switched Nd:YAG laser is safe and effective in reducing facial and non-facial
trunk hair. METHODS: Fifteen patients were treated with a 30 msec pulsed Q
switched Nd:YAG laser at fluences between 125 and 150 J/cm2. The reduction of
hair density was assessed at baseline and at 7, 30, and 90 days after treatment.
Potential complications were also evaluated. RESULTS: The average hair reduction
was 36% at 7 days, 52% at 30 days, and 59% at 90 days. No significant
complications or adverse events were reported. CONCLUSION: The long-pulse Q
switched Nd:YAG laser provides a safe and effective means of hair removal.
PMID- 10691938
TI - Treatment of facial skin using combinations of CO2, Q-switched alexandrite,
flashlamp-pumped pulsed dye, and Er:YAG lasers in the same treatment session.
AB - BACKGROUND: Many patients who seek facial CO2 laser resurfacing for improvement
of photodamage are also concerned with "dark circles" under their eyes
(periorbital hyperpigmentation) and/or telangiectasia as well as various types of
deep scars on their faces. CO2 laser resurfacing alone provides limited
improvement for these problems. OBJECTIVE: The purpose of this study was to
demonstrate the conjunctive therapeutic effects of the CO2, Q-switched
alexandrite, Er:YAG, and/or flashlamp-pumped pulsed dye lasers on facial skin
treatments. METHOD: Thirty patients who underwent CO2 laser resurfacing were
treated with additional lasers specific for their cosmetic concerns. Twenty
patients with facial telangiectasias were treated with the pulsed dye laser
immediately prior to CO2 laser resurfacing. Eleven patients with periorbital
hyperpigmentation were treated with the Q-switched alexandrite laser immediately
following use of the pulsed CO2 laser. Eight patients having sharply defined acne
scars were treated with the Er:YAG laser following use of the CO2 laser. All
patients had peripheral feathering performed with the Er:YAG laser. Nine patients
were treated with all four lasers. RESULTS: In addition to significant
improvement of the wrinkle scores from the CO2 laser resurfacing, patients had 75
100% clearing of the periorbital hyperpigmentation. All patients with facial
telangiectasia showed virtually 100% improvement. All deep wrinkles and sharply
defined scars responded with combined CO2/Er:YAG laser better than with CO2 laser
resurfacing alone. All feathering was more uniform, with a more subtle transition
to nontreated skin. There were no complications that could be attributed to the
simultaneous use of multiple lasers. CONCLUSIONS: For patients who present with
multiple cosmetic complaints, combined treatment using appropriate lasers offers
excellent therapeutic outcome.
PMID- 10691939
TI - The use of conscious sedation for outpatient dermatologic surgical procedures.
AB - BACKGROUND: Dermatologic surgery has undergone increasing levels of
sophistication over the past few decades. Commensurate with this demand, an
established anesthesia technique called conscious sedation has been employed.
OBJECTIVES: Methods for performing office-based conscious sedation are described.
Recommendations are made regarding prerequisites for conscious sedation in an
office setting, patient selection, complications management, and postoperative
discharge requirements. CONCLUSION: The goals of anesthesia are to provide for
patient safety and comfort, to increase patient acceptance of the procedure, and
to enhance the surgeon's efficiency and satisfaction.
PMID- 10691940
TI - Pedunculated malignant melanoma.
AB - BACKGROUND: The pedunculated melanoma is an unusual variant of nodular melanoma
that presents a challenge in staging and management. OBJECTIVE: We discuss the
clinical and histopathologic characteristics of a case of pedunculated melanoma
and present a brief review of the literature. METHODS: Routine stain with
hematoxylin and eosin was performed on tissue specimens. RESULTS: The
pedunculated melanoma was excised. Sentinel lymph node dissection was performed
and was negative for the presence of melanoma. CONCLUSIONS: Pedunculated melanoma
is a rare type of melanoma. Conventional staging methods for melanoma may not be
reliable in this type of tumor. Complete workup, possibly including sentinel
lymph node dissection, should be performed in all patients with pedunculated
melanomas.
PMID- 10691941
TI - Alexandrite laser hair removal is safe for Fitzpatrick skin types IV-VI.
AB - BACKGROUND: Various lasers have been developed for epilation of unwanted hair.
Most studies, however, have been done in white patients with minimal reference to
dark-skinned individuals. OBJECTIVE: To determine the safety profile of a long
pulsed alexandrite laser for hair removal in patients with Fitzpatrick skin types
IV-VI exclusively. METHODS: Prospective clinical evaluation conducted from June
1998 to April 1999 at a referral private clinic. Prelaser skin testing was
performed starting at 16 J/cm2 and energy fluence selected according to response.
Complications were recorded at each visit. RESULTS: One hundred and fifty
patients are reported (18 men and 132 women) ranging in age from 15 to 50 years,
for a total of 550 treatment sites. Complications occurred in only 2% of cases.
CONCLUSION: The long-pulsed alexandrite laser is safe for hair removal in darker
skin tones. Prelaser skin testing was not helpful in this study, as there was no
relationship between skin reaction and the incidence of complications.
PMID- 10691942
TI - Cutaneous hypersensitivity reaction to injectable hyaluronic acid gel.
AB - BACKGROUND: Injectable hyaluronic acid gel is a non-animal biomaterial used for
soft tissue augmentation. OBJECTIVE: The dermal implantation of this naturally
occurring polysaccharide is reported to be well tolerated by patients, with a
longer duration in tissue than bovine collagen without any major local or
systemic side effects. We report a case of an acute hypersensitivity reaction in
a woman after her third injection for improvement of melolabial fold wrinkles.
METHODS: An adverse granulomatous-like response to the intradermal injection of a
modified hyaluronic acid gel is described. RESULTS: The patient developed
indurated and erythematous papulocystic nodules in the melolabial folds
bilaterally at the sites of injection. CONCLUSION: Injectable hyaluronic acid gel
can be associated with severe allergic reactions and patients should be warned of
this possible treatment side effect.
PMID- 10691943
TI - Applicability of the sentinel node technique to Merkel cell carcinoma.
AB - BACKGROUND: Merkel cell carcinoma (MCC) resembles malignant melanoma in several
ways. Both are cutaneous lesions of the same embryonic origin. Both have an
unpredictable biologic behavior, early regional lymph node involvement, early
distant metastases, and high recurrence rate. OBJECTIVE: To apply the sentinel
node technique described for melanoma to MCC in light of the common biologic
features of these two tumors. METHODS: Preoperative lymphoscintigraphy,
intraoperative lymphatic mapping, and sentinel node biopsy and frozen section
histology were performed to guide the surgical treatment of three patients with
MCC. RESULTS: Application of this approach in patients with MCC is feasible,
reproducible, and seems reliable. CONCLUSION: The use of the sentinel node
technique for MCC will reduce the number of unnecessary lymphadenectomies, will
enable identification of microscopic metastases to lymph nodes, and will improve
the stratification and accrual of patients into adjuvant treatment protocols. It
may even lead to a survival benefit.
PMID- 10691944
TI - Electrosurgical suspension apparatus.
AB - BACKGROUND: Dermatologic surgeons commonly employ electrosurgery. OBJECTIVE: We
describe a novel, yet simple, electrosurgical suspension apparatus and variations
that facilitate the performance of excision and repair, Mohs micrographic
surgery, cosmetic surgery, and other forms of dermatologic surgery. METHODS: The
described techniques result from more than a decade of use and refinements in
electrosurgical suspension apparatuses. RESULTS: The use of an electrosurgical
suspension device has eliminated electrosurgical needle stick injuries,
facilitated surgery, and reduced the risk of surgical field contamination via the
electrosurgical handpiece or wiring. CONCLUSION: The use of a suspended
electrosurgical handpiece results in reduced surgical time, eliminates many of
the inconveniences associated with the current use of electrosurgery, and
facilitates the use of electrosurgery as a tool of the dermatologic surgeon.
PMID- 10691945
TI - Wire scalpel for surgical correction of soft tissue contour defects by
subcutaneous dissection.
AB - BACKGROUND: Increasing demand exists for cosmetic correction of soft tissue
contour defects. Treatments include simple tissue augmentation techniques or more
complex surgeries with consequent relevant recuperation time for the patient. The
search for new simple techniques to correct scars and age-related wrinkles and
folds is therefore one of the main goals of cosmetic dermatologic surgery.
OBJECTIVE: To improve the cosmetic outcome of patients suffering from soft tissue
contour defects by the use of a novel surgical instrument and technique,
subcutaneous dissection by wire scalpel. METHODS: Fifty-four patients were
treated with the wire scalpel technique with no skin incisions to correct a total
of 132 depressed cosmetic defects of the face. Forehead lines, glabellar,
nasolabial and oral commissure folds, upper lip wrinkles, and acne scars were
treated. A 2-month to 4-year follow-up allowed subjective and photographic
evaluation of results. RESULTS: Good or satisfactory results were obtained in
79.7% and 16.6% of the cases, respectively. Minor complications did not change
the overall positive outcome of the surgery. CONCLUSION: Subcutaneous dissection
by wire scalpel is a simple, safe, and effective method to improve the contour
appearance of patients affected with scars or age-related contour defects.
PMID- 10691946
TI - Sporadic Bazex-Dupre-Christol-like syndrome: early onset basal cell carcinoma,
hypohidrosis, hypotrichosis, and prominent milia.
AB - BACKGROUND: We present the case of a 32-year-old woman with a large recurrent
multifocal basal cell carcinoma on the scalp. Conspicuous accompanying symptoms
were multiple periorbital milia, hypotrichosis of the body and the scalp, and
hypohidrosis. The sparse hair of the scalp showed further abnormalities such as
pili torti, as well as flattened, irregularly curly hairs. OBJECTIVE: In 1964,
Bazex et al. described a syndrome characterized by congenital hypotrichosis,
follicular atrophoderma, and basocellular neoplasms that included basal cell nevi
and early onset basal cell carcinomas. The Bazex-Dupre-Christol syndrome is a
rare X-linked dominant disease. A sporadic occurrence with the typical
constellation of these symptoms has not yet been reported. The lack of a positive
family history and no signs of follicular atrophoderma argues for a sporadic
occurrence of a Bazex-Dupre-Christol-like syndrome. The case reported shares
several features with the classic Bazex-Dupre-Christol syndrome. CONCLUSION: Our
report documents the necessity to look for early development of basal cell
carcinomas in patients who show signs of the epidermal malformations described.
PMID- 10691948
TI - Follicular unit hair transplanting--end of the evolution or a good thing taken
too far?
PMID- 10691947
TI - Placement of intravenous cannulae prior to ambulatory phlebectomy.
AB - BACKGROUND: Ambulatory phlebectomy (AP) is a popular outpatient procedure for the
removal of varicose veins. One of the major obstacles of AP is the disappearance
and shift of the veins to be removed when the patient is positioned horizontally.
OBJECTIVE: We aimed to verify the usefulness of preoperative placement of
intravenous cannulae. METHODS: Forty-three vein segments of four consecutive
patients with varicose veins were treated by AP with preoperative placement of
intravenous cannulae. The procedures including anesthesia, incision, and
exteriorization of the veins were performed with intravenous cannula in situ. We
compared the courses of cannula and preoperative conventional marking of the
veins. The time spent with extracting a vein was also compared with that spent
with conventional procedure. RESULTS: The preoperative cannulation provides
excellent fixation of varicose veins to their original position, at least at the
puncture sites. The disagreement of courses between cannula and preoperative
conventional marking was noticed in 47.8% of the vein segments from the knees and
thighs, and in 15% from the lower legs. The time spent for extracting a vein was
reduced by more than half with our method. CONCLUSION: Intravenous cannulation
prior to AP is a simple procedure, but significantly improves the technique of AP
by more accurately guiding the site of anesthesia and incision.
PMID- 10691949
TI - In support of follicular unit transplantation.
PMID- 10691950
TI - Sharquie's metal ring in skin surgery.
PMID- 10691951
TI - Is curettage useful prior to performing Mohs or excisional surgery? When and how
do you use it?
PMID- 10691952
TI - Commentary
PMID- 10691953
TI - Lessons on dermoscopy. Diagnosis: dysplastic nevus (so-called Clark nevus).
PMID- 10691954
TI - Regarding successful treatment of spider leg veins.
PMID- 10691955
TI - Response
PMID- 10691956
TI - Regarding invasion of the lacrimal system by basal cell carcinoma.
PMID- 10691957
TI - Regarding the use of topical retinoid acid after dermasanding.
PMID- 10691958
TI - Regarding TCA-based Blue Peel.
PMID- 10691959
TI - Response
PMID- 10691960
TI - The art but not the science...
PMID- 10691961
TI - Laser skin resurfacing: perspectives at the millennium.
PMID- 10691962
TI - Reactive oxygen species released from granulocytes stimulate 5-lipoxygenase
activity in a B-lymphocytic cell line.
AB - B-lymphocytes express 5-lipoxygenase (5-LO) protein but cellular leukotriene
production is suppressed by selenium-dependent peroxidases. Thus it was of
interest to check whether reactive oxygen species (ROS) which are released under
inflammatory conditions can stimulate B-lymphocyte 5-LO and counteract peroxidase
mediated suppression of cellular 5-LO activity. It was found that 5-LO in the
Epstein-Barr virus-transformed B-lymphocytic cell line BL41-E95-A is activated by
addition of hydrogen peroxide or xanthine/xanthine oxidase and after increasing
the oxidative state of the cell by azodicarboxylic acid bis(dimethylamide).
Generation of endogenous ROS from mitochondria by antimycin A also lead to a
threefold upregulation of 5-LO activity in B-cells. There was almost no
detectable endogenous superoxide formation in BL41-E95-A cells after stimulation
with 4beta-phorbol 12-myristate 13-acetate. Co-incubation experiments with BL41
E95-A cells and granulocytes demonstrated that granulocyte-derived ROS can
activate B-lymphocyte 5-LO. Addition of superoxide dismutase and/or catalase to
the B-lymphocyte/granulocyte co-incubations and to B-lymphocyte homogenates
revealed that the 5-LO activation is due to the superoxide-derived release of
hydroperoxides or hydrogen peroxide from granulocytes. The data suggest that ROS
formation plays an important role in the regulation of cellular 5-LO activity in
B-lymphocytes. As leukotrienes affect B-cell functions like cell proliferation,
activation and maturation, this finding provides a new link between the formation
of ROS and the regulation of immune responses.
PMID- 10691963
TI - Kinetic characterization of the substrate specificity and mechanism of mushroom
tyrosinase.
AB - This paper reports a quantitative study of the effect of ring substituents in the
1-position of the aromatic ring on the rate of monophenol hydroxylation and o
diphenol oxidation catalyzed by tyrosinase. A possible correlation between the
electron density of the carbon atom supporting the oxygen from the monophenolic
hydroxyl group and the V Mmax values for each monophenol was found. In the case
of o-diphenols the same effect was observed but the size of the side-chain became
very important. NMR studies on the monophenols justified the sequence of the V
Mmax values obtained. As regards the o-diphenols, on the other hand, only a fair
correlation between NMR and V Dmax values was observed due to the effect of the
molecular size of the ring substituent. From these data, it can be concluded that
the redox step (k33) is not the rate-determining step of the reaction mechanism.
Thus, the monophenols are converted into diphenols, but the order of
specificities towards monophenols is different to that of o-diphenols. The rate
limiting step of the monophenolase activity could be the nucleophilic attack
(k51) of the oxygen atom of the hydroxyl group on the copper atoms of the active
site of the enzyme. This step could also be similar to or have a lower rate of
attack than the electrophilic attack (k52) of the oxygen atom of the active site
of oxytyrosinase on the C-3 of the monophenolic ring. However, the rate-limiting
step in the diphenolase activity of tyrosinase could be related to both the
nucleophilic power of the oxygen atom belonging to the hydroxyl group at the
carbon atom in the 3-position (k32) and to the size of the substituent side
chain. On the basis of the results obtained, kinetic and structural models
describing the monophenolase and diphenolase reaction mechanisms for tyrosinase
are proposed.
PMID- 10691964
TI - Stabilization of NAD-dependent formate dehydrogenase from Candida boidinii by
site-directed mutagenesis of cysteine residues.
AB - The gene of the NAD-dependent formate dehydrogenase (FDH) from the yeast Candida
boidinii was cloned by PCR using genomic DNA as a template. Expression of the
gene in Escherichia coli yielded functional FDH with about 20% of the soluble
cell protein. To confirm the hypothesis of a thiol-coupled inactivation process,
both cysteine residues in the primary structure of the enzyme have been exchanged
by site-directed mutagenesis using a homology model based on the 3D structure of
FDH from Pseudomonas sp. 101 and from related dehydrogenases. Compared to the wt
enzyme, most of the mutants were significantly more stable towards oxidative
stress in the presence of Cu(II) ions, whereas the temperature optima and kinetic
constants of the enzymatic reaction are not significantly altered by the
mutations. Determination of the Tm values revealed that the stability at
temperatures above 50 degrees C is optimal for the native and the recombinant wt
enzyme (Tm 57 degrees C), whereas the Tm values of the mutant enzymes vary in the
range 44-52 degrees C. Best results in initial tests concerning the application
of the enzyme for regeneration of NADH in biotransformation of trimethyl pyruvate
to Ltert leucine were obtained with two mutants, FDHC23S and FDHC23S/C262A, which
are significantly more stable than the wt enzyme.
PMID- 10691965
TI - The role of the membrane-bound tumour antigen, melanotransferrin (p97), in iron
uptake by the human malignant melanoma cell.
AB - Melanotransferrin (MTf) is a membrane-bound transferrin (Tf) homologue with
several characteristics in common with serum Tf. MTf is found at high levels in
melanoma cells and previous studies have shown that MTf can bind Fe. In addition,
Chinese hamster ovary cells transfected with MTf transport Fe from 59Fe-citrate
at greater rates than control cells. However, the role of MTf in the Fe uptake
process of human melanoma cells remains unknown. In the present study we have
characterized the role of MTf in Fe uptake by SK-Mel-28 melanoma cells in order
to understand its function. Initial studies examined whether modulation of
intracellular Fe levels using the Fe chelator desferrioxamine (DFO) or the Fe
donor ferric ammonium citrate (FAC) could change MTf mRNA levels. In contrast to
transferrin receptor (TfR) mRNA that increased after exposure to DFO and
decreased after incubation with FAC, there was no change in MTf mRNA levels. In
addition, compared to control cells, there was no alteration of 125I-labelled
anti-MTf mAb-binding in cells exposed to DFO or FAC, suggesting no change in the
number of MTf sites. Further studies examined the ability of DFO and FAC to
modulate Fe uptake from 59Fe-citrate which is bound by MTf. In contrast to the
effect of DFO or FAC at increasing and decreasing Fe uptake from 59Fe-Tf,
respectively, DFO had no influence on 59Fe-citrate uptake, whereas FAC markedly
increased it. Collectively, these studies suggest that MTf is not regulated in a
manner similar to the TfR in response to cellular Fe levels. MTf can be removed
from the membrane by phosphatidylinositol-specific phospholipase C (PtdIns-PLC).
Preincubation of melanoma cells with PtdIns-PLC reduced anti-MTf mAb binding to
3% of the control, while PtdIns-PLC only slightly reduced 59Fe uptake from 59Fe
citrate. These results suggest that MTf played only a minor role in Fe uptake
from 59Fe-citrate by these cells. The expression of MTf mRNA (poly A+) was also
examined in 50 human tissues and found to be markedly different to Tf mRNA or TfR
mRNA. Surprisingly, MTf mRNA expression was widespread in normal tissues, and was
observed at its highest levels in the salivary gland. In contrast to
expectations, MTf mRNA expression was generally greater in adult than fetal
tissues.
PMID- 10691966
TI - N-Linked glycans of proteins from mitral valves of normal pigs and pigs affected
by endocardiosis.
AB - Endocardiosis, a degenerative and dystrophic process affecting cardiac valves and
described in many mammalian species, is characterized by the accumulation of
glycosaminoglycans, in particular hyaluronic acid, in the extracellular matrix.
The glycoprotein patterns of pig mitral valves in normal animals and animals
affected by endocardiosis were investigated. A different N-linked glycosylation
pattern of glycoproteins was detected in affected valves compared with normal
ones. In either normal or pathological species, the detected N-linked glycans
were of the complex type. However, in samples from affected valves, sialic acid
showed a prevalence of the alpha2,6 linkage to the galactosyl residue, whereas in
normal samples the most frequent linkage was of the alpha2,3 type. In normal
valves, the majority of complex oligosaccharides presented two outer branches
with different degrees of fucosylation and sialylation, whereas in pathological
samples we noted an increased number of glycans having up to four outer branches.
PMID- 10691967
TI - Immunological detection of alkaline-diaminobenzidine-negativeperoxisomes of the
nematode Caenorhabditis elegans purification and unique pH optima of peroxisomal
catalase.
AB - We purified catalase-2 of the nematode Caenorhabditis elegans and identified
peroxisomes in this organism. The peroxisomes of C. elegans were not detectable
by cytochemical staining using 3, 3'-diaminobenzidine, a commonly used method
depending on the peroxidase activity of peroxisomal catalase at pH 9 in which
genuine peroxidases are inactive. The cDNA sequences of C. elegans predict two
catalases very similar to each other throughout the molecule, except for the
short C-terminal sequence; catalase-2 (500 residues long) carries a peroxisomal
targeting signal 1-like sequence (Ser-His-Ile), whereas catalase-1 does not. The
catalase purified to near homogeneity from the homogenate of C. elegans cells
consisted of a subunit of 57 kDa and was specifically recognized by anti
(catalase-2) serum but not by anti-(catalase-1) serum. Subcellular fractionation
and indirect immunoelectron microscopy of the nematode detected catalase-2 inside
vesicles judged to be peroxisomes using morphological criteria. The purified
enzyme (220 kDa) was tetrameric, similar to many catalases from various sources,
but exhibited unique pH optima for catalase (pH 6) and peroxidase (pH 4)
activities; the latter value is unusually low and explains why the peroxidase
activity was undetectable using the standard alkaline diaminobenzidine-staining
method. These results indicate that catalase-2 is peroxisomal and verify that it
can be used as a marker enzyme for C. elegans peroxisomes.
PMID- 10691968
TI - A novel alpha-amylase gene is transiently upregulated during low temperature
exposure in apple fruit.
AB - An alpha-amylase gene product was isolated from apple fruit by reverse
transcriptase PCR using redundant primers, followed by 5' and 3' RACE. The gene
is a member of a small gene family. It encodes a putative 46.9 kDa protein that
is most similar to an alpha-amylase gene from potato (GenBank accession M79328).
In apple fruit this new gene was expressed at low levels, as detected by reverse
transcriptase PCR, in a number of plant tissues and during fruit development.
Highest levels of mRNA for this transcript were observed 3 to 9 days after
placing apple fruit at 0.5 degrees C. Phylogenetic analysis of amino acid
sequence places the potato and apple proteins as a distinct and separate new
subgroup within the plant alpha-amylases, which appears to have diverged prior to
the split between monocotyledonous and dicotyledonous plants. These two divergent
alpha-amylases lack the standard signal peptide structures found in all other
plant alpha-amylases, and have sequence differences within the B-domain and C
domain. However, comparisons with structures of known starch hydrolases suggest
that these differences are unlikely to affect the enzymatic alpha-1,4-amylase
function of the protein. This is the first report of upregulation of a
dicotyledonous alpha-amylase in response to low temperature, and confirms the
presence of a new family of alpha-amylases in plants.
PMID- 10691969
TI - High resolution x-ray analysis of two mutants of a curaremimetic snake toxin.
AB - A previous mutational analysis of erabutoxin a (Ea), a curaremimetic toxin from
sea snake venom, showed that the substitutions S8G and S8T caused, respectively,
176-fold and 780-fold affinity decreases for the nicotinic acetylcholine receptor
(AchR). In view of the fact that the side-chain of Ser8 is buried in the wild
type toxin, we wondered whether these affinity changes reflect a direct binding
contribution of S8 to the receptor and/or conformational changes that could have
occurred in Ea as a result of the introduced mutations. To approach this
question, we solved X-ray structures of the two mutants S8G and S8T at high
resolution (0.18 nm and 0.17 nm, with R factors of 18.0% and 17.9%,
respectively). The data show that none of the mutations significantly modified
the toxin structure. Even within the site where the toxin binds to the receptor
the backbone conformation remained unchanged. Therefore, the low affinities of
the mutants S8T and S8G cannot be explained by a large conformational change of
the toxin structure. Although we cannot exclude the possibility that undetectable
structural changes have occurred in the toxin mutants, our data support the view
that, although buried between loop I and II, S8 is part of the functional epitope
of the toxin.
PMID- 10691970
TI - Expression and regulation of alkaline phosphatases in human breast cancer MCF-7
cells.
AB - The effect of retinoic acid and dexamethasone on alkaline phosphatase (AP)
expression was investigated in human breast cancer MCF-7 cells. Cellular AP
activity was induced significantly by retinoic acid or dexamethasone in a time
dependent and dose-dependent fashion. A marked synergistic induction of AP
activity was observed when the cells were incubated with both agents
simultaneously. Two AP isozymes, tissue-nonspecific (TNAP) and intestinal (IAP),
were shown to be expressed in MCF-7 cells as confirmed by the differential rate
of thermal inactivation of these isozymes and RT-PCR. Based on the two-isozyme
thermal-inactivation model, the specific activities for TNAP and IAP in each
sample were analyzed. TNAP activity was induced only by retinoic acid and IAP
activity was induced only by dexamethasone. Whereas dexamethasone conferred no
significant effect on TNAP activity, retinoic acid was shown to inhibit IAP
activity by approximately 50%. Interestingly, TNAP was found to be the only
isozyme activity superinduced when the cells were costimulated with retinoic acid
and dexamethasone. Northern blot and RT-PCR analysis were then used to
demonstrate that the steady-state TNAP mRNA level was also superinduced, which
indicates that the superinduction is regulated at the transcriptional or post
transcriptional levels. In the presence of the glucocorticoid receptor antagonist
RU486, the dexamethasone-mediated induction of IAP activity was blocked
completely as expected. However, the ability of RU486 to antagonize the action of
glucocorticoid was greatly compromised in dexamethasone-mediated superinduction
of TNAP activity. Furthermore, in the presence of retinoic acid, RU486 behaved as
an agonist, and conferred superinduction of TNAP gene expression in the same way
as dexamethasone. Taken together, these observations suggest that the induction
of IAP activity by dexamethasone and the superinduction of TNAP by dexamethasone
were mediated through distinct regulatory pathways. In addition, retinoic acid
plays an essential role in the superinduction of TNAP gene expression by enabling
dexamethasone to exert its agonist activity, which otherwise has no effect.
PMID- 10691971
TI - Ligand binding inhibitors of A1 adenosine receptor from Rana rugosa are
phospholipase A2s.
AB - Inhibitors of the A1 adenosine receptor were isolated from the skin extract of
Korean frog, Rana rugosa. The frog-skin extract was prepared by an electrical
shock and fractionated with C4 followed by C18 reverse-phase HPLC. Two A1
receptor inhibitors were isolated using a filter binding assay and the molecular
masses of the proteins were estimated by matrix-assisted laser desorption
ionization time-of-flight mass spectrometry to be 15 347 and 15 404 Da,
respectively. The inhibitory activity was also measured against other membrane
receptors, such as the A2 adenosine receptor, muscarinic acetylcholine receptor
and capsaicin receptor. Ligand binding to the A2 and muscarinic receptors was
also severely inhibited by these proteins. However, they did not inhibit the
functional activation of the capsaicin receptor by its ligand, capsaicin,
suggesting that inhibition of ligand-receptor binding occurs specifically. Their
N-terminal sequences were determined by Edman degradation. Surprisingly, they
showed sequence similarity to the secretory protein, phospholipase A2 from
various organisms. The phospholipase A2 activity of both proteins was tested
using Dole's assay technique. Both proteins showed phospholipase A2 activity, and
therefore, they were designated as PLA2-R1 and PLA2-R2, respectively. In
addition, their ligand-binding inhibitory activity depended on their
phospholipase A2 activity. This is the first finding that the frog secretes a
phospholipase A2 similar to that of snake venoms, which posess inhibitory
activity against the adenosine A1, adenosine A2 and muscarinic receptors.
PMID- 10691972
TI - Characterization of the 5'-flanking region of the human multidrug resistance
protein 2 (MRP2) gene and its regulation in comparison withthe multidrug
resistance protein 3 (MRP3) gene.
AB - The multidrug resistance proteins MRP2 (symbol ABCC2) and MRP3 (symbol ABCC3) are
conjugate export pumps expressed in hepatocytes. MRP2 is localized exclusively to
the apical membrane and MRP3 to the basolateral membrane. MRP2 mRNA is expressed
at a high level under normal conditions, whereas MRP3 mRNA expression is low and
increases only when secretion across the apical membrane by MRP2 is impaired. We
studied some of the regulatory properties of the two human genes using transient
transfection assays with promoter-luciferase constructs in HepG2 cells and cloned
fragments of 1229 nucleotides and 1287 nucleotides of the MRP2 and MRP3 5'
flanking regions, respectively. The sequence between nucleotides -517 and -197
was decisive for basal MRP2 expression. Basal promoter activity of MRP3 was only
4% of that measured for MRP2. At submicromolar concentrations, the histone
deacetylase inhibitor trichostatin A reduced the MRP2 reporter gene activity and
expression of the protein. Disruption of microtubules with nocodazole decreased
gene and protein expression of MRP2 and increased MRP3 reporter gene activity.
The genotoxic 2-acetylaminofluorene decreased the activity of the human MRP2
reporter gene construct, but increased MRP3 gene activity and enhanced the
amounts of mRNA and protein of MRP2 and MRP3. Thus, regulation of the expression
of these ATP-dependent conjugate export pumps is not co-ordinate, but in part
inverse. The inverse regulation of the two MRP isoforms is consistent with their
distinct localization, their different mRNA expression under normal and
pathophysiological conditions, and their different directions of substrate
transport in polarized cells.
PMID- 10691973
TI - Purification, cloning and sequence analyses for pro-metalloprotease-disintegrin
variants from Deinagkistrodon acutus venom and subclassification of the small
venom metalloproteases.
AB - Acidic and basic hemorrhagic metalloproteases were purified from the venom of
Deinagkistrodon acutus (from Fujian Province, China) using gel filtration and
anion exchange on FPLC and reversed-phase HPLC. Their hemorrhagic activities and
N-terminal sequences were characterized. Extensive screening of the venom gland
cDNA after PCR amplification resulted in the identification and sequencing of a
total of seven cDNA clones encoding the multidomain precursors of six acidic and
one alkaline low molecular mass metalloproteases. Two of the precursors contain a
processable disintegrin domain. Disintegrins of 5 kDa were also purified from the
venom. The partial amino-acid sequences and molecular masses determined by
electrospray ionization mass spectrometry of the purified proteins specifically
match those deduced from two of the cDNA sequences. Moreover, phylogenetic
analyses based on 30 complete sequences of low molecular mass venom
metalloproteases revealed that they may be classified into three functional
subtypes: acidic hemorrhagins, basic and moderate hemorrhagins, and
nonhemorrhagic enzymes. Subtype-specific amino-acid substitutions in the C
terminal regions of the enzymes were highlighted to explore the structure
activity relationships of the enzymes.
PMID- 10691974
TI - Structural investigations of the CuA centre of nitrous oxide reductase from
Pseudomonas stutzeri by site-directed mutagenesis and X-ray absorption
spectroscopy.
AB - Nitrous oxide reductase is the terminal component of a respiratory chain that
utilizes N2O in lieu of oxygen. It is a homodimer carrying in each subunit the
electron transfer site, CuA, and the substrate-reducing catalytic centre, CuZ.
Spectroscopic data have provided robust evidence for CuA as a binuclear, mixed
valence metal site. To provide further structural information on the CuA centre
of N2O reductase, site directed mutagenesis and Cu K-edge X-ray absorption
spectroscopic investigation have been undertaken. Candidate amino acids as
ligands for the CuA centre of the enzyme from Pseudomonas stutzeri ATCC14405 were
substituted by evolutionary conserved residues or amino acids similar to the wild
type residues. The mutations identified the amino acids His583, Cys618, Cys622
and Met629 as ligands of Cu1, and Cys618, Cys622 and His626 as the minimal set of
ligands for Cu2 of the CuA centre. Other amino acid substitutions indicated
His494 as a likely ligand of CuZ, and an indirect role for Asp580, compatible
with a docking function for the electron donor. Cu binding and spectroscopic
properties of recombinant N2O reductase proteins point at intersubunit or
interdomain interaction of CuA and CuZ. Cu K-edge X-ray absorption spectra have
been recorded to investigate the local environment of the Cu centres in N2O
reductase. Cu K-edge Extended X-ray Absorption Fine Structure (EXAFS) for
binuclear Cu chemical systems show clear evidence for Cu backscattering at
approximately 2.5 A. The Cu K-edge EXAFS of the CuA centre of N2O reductase is
very similar to that of the CuA centre of cytochrome c oxidase and the optimum
simulation of the experimental data involves backscattering from a histidine
group with Cu-N of 1.92 A, two sulfur atoms at 2.24 A and a Cu atom at 2. 43 A,
and allows for the presence of a further light atom (oxygen or nitrogen) at 2.05
A. The interpretation of the CuA EXAFS is in line with ligands assigned by site
directed mutagenesis. By a difference spectrum approach, using the Cu K-edge
EXAFS of the holoenzyme and that of the CuA-only form, histidine was identified
as a major contributor to the backscattering. A structural model for the CuA
centre of N2O reductase has been generated on the basis of the atomic coordinates
for the homologous domain of cytochrome c oxidase and incorporating our current
results and previous spectroscopic data.
PMID- 10691975
TI - Use of proteoliposomes to generate phage antibodies against native AMPA receptor.
AB - To isolate antibodies against ionotropic glutamate receptors (GluRs), we prepared
a phage antibody library from mice immunized with proteoliposomes containing
purified alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), a
selective GluRD receptor. Specific binders were selected by repeated rounds of
affinity panning against immobilized GluRD liposomes. Using this approach, we
obtained a panel of high-affinity antibody fragments that immunoprecipitated both
recombinant and native GluRD receptors, but not GluR6, a kainate receptor subunit
with a 40% sequence similarity. The antibody fragments showed subunit
selectivity, some being strictly specific for GluRD, whereas others also
recognized the GluRB and GluRC but not GluRA subunits. Further experiments
indicated that the epitopes recognized were conformational in nature and reside
in the N-terminal extracellular 400-residue X domain of GluRD. Our results
suggest that proteoliposomes, in combination with phage display technology,
provide an effective tool for the generation of high-affinity conformation
sensitive monoclonal antibodies against predetermined membrane proteins.
PMID- 10691976
TI - Structure and dynamics of lipid-associated states of apocytochrome c.
AB - Apocytochrome c (apocyt c), which in aqueous solution is largely unstructured,
acquires an alpha-helical conformation upon association with lipid membranes. The
extent of alpha-helix induced in apocyt c is lipid-dependent and this folding
process is driven by both electrostatic and hydrophobic lipid-protein
interactions. The structural and dynamic properties of apocyt c in lipid
membranes were investigated by attenuated total reflection Fourier transform
infrared spectroscopy combined with amide H-D exchange kinetics. Apocyt c
acquires a higher content of alpha-helical structure with negatively charged
membranes than with zwitterionic ones. For all membranes studied here, the
helices of these partially folded states of apocyt c have a preferential
orientation perpendicular to the plane of the lipid membrane. The H-D exchange
revealed that a small fraction of amide protons of apocyt c, possibly associated
with a stable folded domain protected by the lipid, remained protected from
exchange over 20 min. However, a large fraction of amide protons exchanged in
less than 20 min, indicating that the helical states of apocyt c in lipid
membranes are very dynamic.
PMID- 10691977
TI - The gene encoding polyneuridine aldehyde esterase of monoterpenoid indole
alkaloid biosynthesis in plants is an ortholog of the alpha/betahydrolase super
family.
AB - The biosynthesis of the anti-arrhythmic alkaloid ajmaline is catalysed by more
than 10 specific enzymes. In this multistep process polyneuridine aldehyde
esterase (PNAE) catalyses a central reaction by transforming polyneuridine
aldehyde into epi-vellosimine, which is the immediate precursor for the synthesis
of the ajmalane skeleton. PNAE was purified from cell suspension cultures of
Rauvolfia serpentina. The N-terminal sequence and endoproteinase LysC fragments
of the purified protein were used for primer design and for the amplification of
specific PCR products leading to the isolation of PNAE-encoding cDNA from a R.
serpentina library. The PNAE cDNA was fused with a C-terminal His-tag, expressed
in Escherichia coli and purified to homogeneity using Ni-affinity chromatography.
The pure enzyme shows extraordinary substrate specificity, completely different
to other esterases. Sequence alignments indicate that PNAE is a new member of the
alpha/beta hydrolase super family.
PMID- 10691978
TI - Inactivation of calcineurin by hydrogen peroxide and phenylarsine oxide. Evidence
for a dithiol-disulfide equilibrium and implications for redox regulation.
AB - Calcineurin (CaN) is a Ca2+-and calmodulin (CaM)-dependent serine/threonine
phosphatase containing a dinuclear Fe-Zn center in the active site. Recent
studies have indicated that CaN is a possible candidate for redox regulation. The
inactivation of bovine brain CaN and of the catalytic CaN A-subunit from
Dictyostelium by the vicinal dithiol reagents phenylarsine oxide (PAO) and
melarsen oxide (MEL) and by H2O2 was investigated. PAO and MEL inhibited CaN with
an IC50 of 3-8 microM and the inactivation was reversed by 2, 3-dimercapto-1
propane sulfonic acid. The treatment of isolated CaN with hydrogen peroxide
resulted in a concentration-dependent inactivation. Analysis of the free thiol
content performed on the H2O2 inactivated enzyme demonstrated that only two or
three of the 14 Cys residues in CaN are modified. The inactivation of CaN by H2O2
could be reversed with 1,4-dithiothreitol and with the dithiol oxidoreductase
thioredoxin. We propose that a bridging of two closely spaced Cys residues in the
catalytic CaN A-subunit by PAO/MEL or the oxidative formation of a disulfide
bridge by H2O2 involving the same Cys residues causes the inactivation. Our data
implicate a possible involvement of thioredoxin in the redox control of CaN
activity under physiological conditions. The low temperature EPR spectrum of the
native enzyme was consistent with a Fe3+-Zn2+ dinuclear centre. Upon H2O2
mediated inactivation of the enzyme no significant changes in the EPR spectrum
were observed ruling out that Fe2+ is present in the active enzyme and that the
dinuclear metal centre is the target for the oxidative inactivation of CaN.
PMID- 10691979
TI - DNase I hypersensitive sites and transcriptional activation of the lamin A/C
gene.
AB - The lamin A/C gene encodes subtypes of nuclear lamins, which are involved in
nuclear envelope formation, and was recently identified as the responsible gene
for the autosomal dominant Emery-Dreifuss muscular dystrophy. Expression of the
lamin A/C gene is developmentally regulated but little is known about the
regulatory mechanism. Previous studies of lamin A/C expression suggested that the
chromatin structure is important for the regulation of its expression. To
elucidate the regulatory mechanism of the lamin A/C gene expression, we have
analysed the functional region of the mouse lamin A/C promoter and the chromatin
structure of the gene in terms of nucleosome structure and DNase I
hypersensitivity. Our analyses revealed disruption of the nucleosome array at the
promoter region and the presence of multiple DNase I hypersensitive sites (HSs)
which were specifically associated with expression of the lamin A/C gene.
Inclusion of a segment which contained the HSs in a lamin A/C promoter-luciferase
reporter plasmid showed no effect on the transfected promoter activity in
transient expression assays. On the other hand, substantial enhancement of the
promoter activity was detected when the transfected DNA was stably integrated
into the genome, suggesting the importance of the HSs in the regulation of lamin
A/C expression.
PMID- 10691980
TI - Molecular mode of interaction of plant amine oxidase with the mechanism-based
inhibitor 2-butyne-1,4-diamine.
AB - 2-Butyne-1,4-diamine (DABI) is a mechanism-based inhibitor of copper-containing
plant amine oxidases; the number of turnovers that leads to enzyme inactivation
is approximately 20. The product of DABI oxidation is a very reactive aminoallene
that reacts with an essential nucleophilic group at the enzyme active site,
forming a covalently bound pyrrole and producing an inactive enzyme. The
inactivated enzyme shows a new absorption maximum at 295 nm and gives coloured
derivatives with p-dimethylaminobenzaldehyde and p-dimethylaminocinnamaldehyde
that are spectrally similar to the products of pyrrole treated with the above
reagents. Resonance Raman spectra of the p-dimethylaminobenzaldehyde adduct of
pyrrole and the inactivated enzyme show very high degree of similarity,
supporting the idea that the product of inactivation is indeed a bound pyrrole.
The bound pyrrole is formed already in the anaerobic step of the reaction, while
the topa semiquinone radical is not affected, as shown by the EPR and stopped
flow absorption measurements. Peptides containing the DABI binding site were
obtained by proteolysis of inactivated enzyme, isolated by HPLC and analysed by
amino acid sequencing and MS. The crystal structure of the amine oxidase from pea
has been determined; inhibition is caused mainly by the highly reactive DABI
product, 4-amino-2-butynal, binding to a nucleophilic residue at the entrance to
the substrate channel. As other DABI labelled peptides were also found and no
free DABI product was detected by MS after complete inhibition of the enzyme, it
is likely that the DABI product binds also to other solvent exposed nucleophilic
residues on the enzyme surface.
PMID- 10691981
TI - Biochemical and functional characterization of the Tn-specific lectin from Salvia
sclarea seeds.
AB - SSL, the lectin isolated from Salvia sclarea seeds, recognizes the Tn antigen
(GalNAcalpha-O-Ser/Thr), a specific marker of many human carcinomas. Two
dimensional electrophoresis, amino-acid and amino-sugar analysis, and MALDI-TOF
MS showed that SSL is an acidic (pI 5.5), 60-61-kDa dimeric glycoprotein composed
of apparently identical subunits linked by a single disulfide bond. The apparent
molecular mass of SSL in solution determined by equilibrium sedimentation
analytical ultracentrifugation was 59 +/- 9 kDa. This value did not change in the
pH range 2.5-8.5, indicating that SSL does not associate into higher order
structures. Tandem mass spectrometry and methylation analysis of N-glycans
released from SSL by hydrazinolysis indicated that SSL possesses 2-3
glycosylation sites occupied with the typical plant glycans Manalpha1
6[(Manalpha1-3)(Xylbeta1-2)]Manbeta1-4 -GlcNAcbeta1-4(Fucalp ha1-3)GlcNAc and
[(Manalpha1-3/6)(Xylbeta1-2)]Manbeta1-4-GlcNAcbeta1 -4(Fucalpha1-3)Glc NAc. The
influence of adjacent Tn structures on the binding of two Tn-specific lectins
(SSL and the isolectin B4 from Vicia villosa) and an anti-Tn monoclonal antibody
(mAb 83D4) was evaluated using synthetic Tn glycopeptides. The binding of both
lectins to the synthetic Tn glycopeptides was independent of the density of Tn
structures. On the other hand, mAb 83D4 only reacted with glycopeptides
displaying two or three consecutive Tn structures.
PMID- 10691982
TI - His230 of serine hydroxymethyltransferase facilitates the proton abstraction step
in catalysis.
AB - The three-dimensional structures of rabbit and human liver cytosolic serine
hydroxymethyltransferase revealed that H231 interacts with the O3' of pyridoxal
5'-phosphate and other residues at the active site such as S203, K257, H357 and
R402 (numbering as per the human enzyme). This and the conserved nature of H231
in all serine hydroxymethyltransferases highlights its importance in catalysis
and/or maintenance of oligomeric structure of the enzyme. In an attempt to
decipher the role of H230 (H231 of the human enzyme) in the catalytic mechanism
and/or maintenance of oligomeric structure of sheep liver serine
hydroxymethyltransferase, the residue was mutated to arginine, phenylalanine,
alanine, asparagine or tyrosine. Our results suggest that the nature of the amino
acid substitution has a marked effect on the catalytic activity of the enzyme.
H230R and H230F mutant proteins were completely inactive, dimeric and did not
bind pyridoxal-5'-phosphate. On the other hand, mutation to alanine and
asparagine retained the oligomeric structure and ability to bind pyridoxal-5'
phosphate. These mutants had only 2-3% catalytic activity. The side reactions
like transamination and 5,6,7, 8-tetrahydrofolate independent aldol cleavage were
much more severely affected. They were able to form the external aldimine with
glycine and serine but the quinonoid intermediate was not observed upon the
addition of 5,6,7,8-tetrahydrofolate. Mutation to tyrosine did not affect the
oligomeric structure and pyridoxal-5'-phosphate binding. The H230Y enzyme was 10%
active and showed a correspondingly lower amount of quinonoid intermediate. The
kcat / Km values for L-serine and Lallothreonine were 10-fold and 174-fold less
for this mutant enzyme compared to the wild-type protein. These results suggest
that H230 is involved in the step prior to the formation of the quinonoid
intermediate, possibly in orienting the pyridine ring of the cofactor, in order
to facilitate effective proton abstraction.
PMID- 10691983
TI - Structure-function relationships of temporins, small antimicrobial peptides from
amphibian skin.
AB - Temporins, antimicrobial peptides of 10-13 residues, were isolated from
secretions of Rana temporaria [Simmaco, M., Mignogna, G., Canofeni, S., Miele,
R., Mangoni, M.L. & Barra, D. (1996) Eur. J. Biochem. 242, 788-792]. These
molecules are specific to this amphibian species, which is also able to secrete
on its skin other antimicrobial peptides similar to those found in different Rana
species. The effect of temporins A, B and D (13 residues, net charge +2), and H
(10 residues, net charge +1 and +2, respectively) against both artificial
membranes of differing lipid composition and bacteria has been investigated in
order to gain insight into their mechanisms of action. The results indicate that:
the lytic activity of temporins is not greatly affected by the membrane
composition; temporins A and B allow the leakage of large-size molecules from the
bacterial cells; temporin H renders both the outer and inner membrane of bacteria
permeable to hydrophobic substances of low molecular mass; and temporin D,
although devoid of antibacterial activity, has a cytotoxic effect on
erythrocytes. The results allow important conclusions to be drawn about the
minimal structural requirements for lytic efficiency and specificity of
temporins.
PMID- 10691984
TI - Characterization of a novel type VII beta-turn conformation for a bio-active
tetrapeptide rigin A synergy between theoretical and experimental results.
AB - The conformational analysis of an immunomodulating tetrapeptide rigin (H-Gly-Gln
Pro-Arg-OH), shown to possess diverse immunological activity, has been
investigated both theoretically and experimentally for its conformational
preferences. Unrestrained molecular dynamics simulation studies in implicit
dimethylsulfoxide provide strong support for the existence of a significant
population of ordered reverse turn structures for the major trans isomer. Of the
three different energy minimized families, generated from computer molecular
modelling, only one could be complemented by most of the 1D and 2D 1H NMR
parameters obtained in dimethylsulfoxide-d6. A variable temperature NMR
experiment in dimethylsulfoxide-d6 revealed that the preferred conformation is
not stabilized by an intramolecular hydrogen bonding interaction. An analysis of
the 2D ROESY experiment provides evidence in favour of an uncommonly observed,
rather ill-defined type VII beta-turn structure. A survey of the observed
specific inter-and intra-residue NOE connectivities and their comparison with one
of the predicted low-energy conformations, demonstrates synergy between the
theoretical molecular modelling and experimentally determined NMR spectral data.
The primary structure, rather than long-range interactions, appears to be
critical in determining the folding behaviour of the bio-active rigin. The
present structural attributes may be valuable in peptide drug design and
development of the rigin analogs having more effective stimulating activity.
PMID- 10691985
TI - Trypanosoma brucei contains a 2,3-bisphosphoglycerate independent
phosphoglycerate mutase.
AB - Assays of phosphoglycerate mutase (PGAM) activity in lysates of bloodstream form
Trypanosoma brucei appeared not to require exogenous 2,3-bisphosphoglycerate,
thus suggesting that this protist contains an enzyme belonging to the class of
cofactor-independent PGAMs. A gene encoding a polypeptide with motifs
characteristic for this class of enzymes was cloned. The predicted T. brucei PGAM
polypeptide contains 549 amino acids, with Mr 60 557 and pI 5.5. Comparison with
15 cofactor-independent PGAM sequences available in databases showed that the
amino-acid sequence of the trypanosome enzyme has 59-62% identity with plant
PGAMs and 29-35% with eubacterial enzymes. A low 28% identity was observed with
the only available invertebrate sequence. The trypanosome enzyme has been
expressed in Escherichia coli, purified to homogeneity and subjected to
preliminary kinetic analysis. Previous studies have shown that cofactor-dependent
and -independent PGAMs are not homologous. It has been inferred that the cofactor
independent PGAMs are in fact homologous to a family of metalloenzymes containing
alkaline phosphatases and sulphatases. Prediction of the secondary structure of
T. brucei PGAM and threading the sequence into the known crystal structure of E.
coli alkaline phosphatase (AP) confirmed this homology, despite the very low
sequence identity. Generally, a good match between predicted (PGAM) and actual
(AP) secondary structure elements was observed. In contrast to trypanosomes,
glycolysis in all vertebrates involves a cofactor-dependent PGAM. The presence of
distinct nonhomologous PGAMs in the parasite and its human host offers great
potential for the design of selective inhibitors which could form leads for new
trypanocidal drugs.
PMID- 10691986
TI - The transbilayer distribution of phospholipids in disc membranes is a dynamic
equilibrium evidence for rapid flip and flop movement.
AB - We studied the transbilayer redistribution of phospholipids in bovine rod outer
segment membranes on thoroughly washed, Ficoll-floated osmotically intact disc
vesicles; freshly prepared membranes separated from the disc stack by osmotic
shock; and intact disc stacks with a permeabilized plasma membrane (A-discs, B
discs C-discs, respectively). In all cases, spin-labelled phospholipid analogues
(SL-PL) with choline, serine and ethanolamine head groups (PtdCho, PtdSer and
PtdEtn, respectively) were taken up into the outer leaflet of the membranes by >
90% and within less than 30 s after SL-PL addition, as deduced from the
disappearance of spin-label from the suspension medium and from the specific ESR
spectrum of membrane-associated spin-label. Using BSA extraction, the amount of
SL-PL in the outer leaflet of the bilayer was determined. It decreased with a
mean half-time of < 5 min at 25 degrees C, indicating rapid redistribution of all
spin-labelled phospholipids into the inner leaflet of the disc membranes. After 1
h, PtdCho and PtdEtn were distributed almost symmetrically, whereas PtdSer was 35
: 65% (in/out). Using subsequent incubation with BSA, the outward movement (flop)
of the analogues was observed directly, demonstrating that inward and outward
movements proceed in thermodynamic equilibrium. No effect of N-ethylmaleimide or
ATP on the redistribution could be measured, which makes it unlikely that energy
consuming translocase or flippase processes are involved in the redistribution in
the dark. We reason that the solubilization zone around the photoreceptor
rhodopsin may be the locus of rapid redistribution of the highly unsaturated disc
phospholipid.
PMID- 10691987
TI - Ribonucleases expressed by human pancreatic adenocarcinoma cell lines.
AB - Human ribonucleases have been considered as a possible tumor marker for
pancreatic cancer, and elevated serum levels of ribonuclease activity in patients
with pancreatic cancer have been reported by many authors. The reason for this
elevation is unknown. In this study, we demonstrate that human pancreatic
adenocarcinoma cell lines synthesize and secrete different ribonucleases. We
isolated and characterized human pancreatic, or secretory, ribonuclease (RNase 1)
from the conditioned media of the human pancreatic adenocarcinoma cell lines
Capan-1, MDAPanc-3, IBF-CP3 and Panc-1, and the ampullary adenocarcinoma cell
line MDAAmp-7, which represent a wide range of differentiation stages. Only one
of these cell lines, Panc-1, produces significant amounts of nonsecretory
ribonuclease. We then established a purification procedure for both secretory and
nonsecretory ribonucleases, consisting of concentration of the supernatant by
tangential filtration, anion-exchange and cation-exchange liquid chromatography
and C4 RP-HPLC. Ribonuclease activity fractions were monitored using both the
spectrophotometric and negative-staining zymogram techniques. The results of N
terminal sequence analysis, kinetic analysis and endoglycosidase digestion
studies indicate that the main ribonuclease secreted by all the cell lines is the
secretory-type ribonuclease and that it is composed of several differently N
glycosylated forms. Northern blot analyses confirm that some of the cell lines
express secretory ribonuclease mRNA. The mRNA levels produced by Panc-1 and
MDAPanc-28 are too low to be detected. Similar levels of expression of
nonsecretory ribonuclease are found by Northern blot analysis in all the cell
lines except Panc-1, which expresses higher levels. Here, we describe, for the
first time, that several human pancreatic cancer cell lines with different
degrees of differentiation express and secrete ribonucleases. This fact indicates
that one origin of the elevated serum RNase levels in patients with pancreatic
cancer are tumor cells. Analysis of the oligosaccharide moiety of the RNase 1
secreted by Capan-1 shows that it is highly glycosylated and its N-glycan chains
are significantly different from that of the RNase 1 produced by normal pancreas.
These results renew the possibility of using human serum RNase 1 determination as
a tumor marker.
PMID- 10691988
TI - Assessment of amino-acid substitutions at tryptophan 16 in alpha-galactosidase.
AB - The tryptophan residue at position 16 of coffee bean alpha-galactosidase has
previously been shown to be essential for enzyme activity. The potential role of
this residue in the catalytic mechanism has been further studied by using site
directed mutagenesis to substitute every other amino acid for tryptophan at that
site. Mutant enzymes were expressed in Pichia pastoris, a methylotrophic yeast
strain, and their kinetic parameters were calculated. Only amino acids containing
aromatic rings (phenylalanine and tyrosine) were able to support a significant
amount of enzyme activity, but the kinetics and pH profiles of these mutants
differed from wild-type. Substitution of arginine, lysine, methionine, or
cysteine at position 16 allowed a small amount of enzyme activity with the
optimal pH shifted towards more acidic. All other residues abolished enzyme
activity. Our data support the hypothesis that tryptophan 16 is affecting the pKa
of a carboxyl group at the active site that participates in catalysis. We also
describe an assay for continuously measuring enzyme kinetics using fluorogenic 4
methylumbelliferyl substrates. This is useful in screening enzymes from colonies
and determining the enzyme kinetics when the enzyme concentration is not known.
PMID- 10691989
TI - Contribution of C-tail residues of potato carboxypeptidase inhibitor to the
binding to carboxypeptidase A A mutagenesis analysis.
AB - The role of each residue of the potato carboxypeptidase inhibitor (PCI) C
terminal tail, in the interaction with carboxypeptidase A (CPA), has been studied
by the analysis of two main kinds of site-directed mutants: the point
substitution of each C-terminal residue by glycine and the sequential deletions
of the C-terminal residues. The mutant PCI-CPA interactions have been
characterized by the measurement of their inhibition constant, Ki, in several
cases, by their kinetic association and dissociation constants determined by
presteady-state analysis, and by computational approaches. The role of Pro36
appears to be mainly the restriction of the mobility of the PCI C-tail. In
addition, and unexpectedly, both Gly35 and Pro36 have been found to be important
for folding of the protein core. Val38 has the greatest enthalpic contribution to
the PCI-CPA interaction. Although Tyr37 has a minor contribution to the binding
energy of the whole inhibitor, it has been found to be essential for the
interaction with the enzyme following the cleavage of the C-terminal Gly39 by
CPA. The energetic contribution of the PCI secondary binding site has been
evaluated to be about half of the total free energy of dissociation of the PCI
CPA complex.
PMID- 10691990
TI - Nucleotide and amino-acid sequences of a new-type pectate lyase from an
alkaliphilic strain of Bacillus.
AB - A pectate lyase (pectate transeliminase; EC 4.2.2.2), designated Pel-15E, was
purified to homogeneity from a culture broth of alkaliphilic Bacillus sp. strain
KSM-P15. The purified enzyme had a molecular mass of approximately 33 kDa, as
determined by SDS/PAGE, and a pI of approximately pH 9.2. Pel-15E exhibited
optimum activity at pH 10.5 and 50-55 degrees C in glycine/NaOH buffer. Pel-15E
had an absolute requirement for Ca2+ ions for manifestation of the enzymatic
activity and trans-eliminated poly(galacturonic) acid, most likely by endo-type
cleavage. A gene for the enzyme, which was cloned using the shotgun method and
sequenced, contained a 960-bp ORF encoding 320 amino acids. The mature enzyme
(286 amino acids, 32 085 Da) from the deduced amino-acid sequence showed quite
low homology to known Pels from various microorganisms with 16.1-20.4% identity.
Furthermore, we were not able to find any conserved regions in the sequence of
Pel-15E when aligned with the sequences of other enzymes from the established Pel
superfamily. However, Pel-15E had some regions that were homologous to PelA from
Azospirillum irakense with 39.8% identity. Based on their amino-acid sequence
homology, Pel-15E and PelA appear to belong to a new class of Pel family,
although the enzymatic properties of both enzymes were quite different.
PMID- 10691991
TI - Amino-acid sequence and glycan structures of cysteine proteases with proline
specificity from ginger rhizome Zingiber officinale.
AB - The ginger proteases (GP-I and GP-II), isolated from the ginger rhizome Zingiber
officinale, have an unusual substrate specificity preference for cleaving
peptides with a proline residue at the P2 position. The complete amino-acid
sequence of GP-II, a glycoprotein containing 221 amino acids, and about 98% that
of GP-I have been determined. Both proteases, which are 82% similar, have
cysteine residues at positions 27 and histidines at position 161, corresponding
to the essential cysteine-histidine diads found in the papain family of cysteine
proteases, and six corresponding cysteine residues that form the three invariant
disulfide linkages seen in this family of proteins. The sequence homology with
other members (papain, bromelain, actinidin, protease omega, etc.) of this family
is approximately 50%. GP-II has two predicted glycosylation sites at Asn99 and
Asn156. Analyisis by electrospray and collision-induced dissociation MS showed
that both sites were occupied by the glycans (Man)3(Xyl)1(Fuc)1(GlcNAc)2 and
(Man)3(Xyl)1(Fuc)1(GlcNAc)3, in a ratio of approximately 7 : 1. Both glycans are
xylose containing biantennary complex types that share the common core structural
unit, Man1-->6(Man1-->3) (Xyl1-->2)Man1-->4GlcNAc1-->4(Fuc1-->3)GlcNAc for the
major form, with an additional N-acetylglucosamine residue being linked, in the
minor form, to one of the terminal mannose units of the core structure.
PMID- 10691992
TI - In vitro study of proteolytic degradation of rat histidine decarboxylase.
AB - Mammalian ornithine decarboxylase (ODC) is a very unstable protein which is
degraded in an ATP-dependent manner by proteasome 26S, after making contact with
the regulatory protein antizyme. PEST regions are sequences described as signals
for protein degradation. The C-terminal PEST region of mammalian ODC is essential
for its degradation by proteasome 26S. Mammalian histidine decarboxylase (HDC) is
also a short-lived protein. The full primary sequence of mammalian HDC contains
PEST-regions at both the N- and C-termini. Rat ODC and different truncated and
full versions of rat HDC were expressed in vitro. In vitro degradation of rat ODC
and rat 1-512 HDC were compared. Like ODC, rat 1-512 HDC is degraded mainly by an
ATP-dependent mechanism. However, antizyme has no effect on the degradation of 1
512 HDC. The use of the inhibitors MG-132 and lactacystine significantly
inhibited the degradation of 1-512 HDC, suggesting that a ubiquitin-dependent,
proteasome 26S proteolytic pathway is involved. Results obtained with the
different modifications of rat HDC containing all three PEST regions (full
version, 1-656 HDC), only the N-terminal PEST region (1-512 HDC), or no PEST
region (69-512 HDC), indicate that the N-terminal (1-69) fragment, but not the C
terminal fragment, determines that the HDC protein is a proteasome substrate in
vitro.
PMID- 10691993
TI - Exhaled nitric oxide during incremental and constant workload exercise in chronic
cardiac failure.
AB - BACKGROUND: Nitric oxide (NO) is present in exhaled breath and produced by the
pulmonary vascular endothelium as a potent vasodilator. Exercise is normally
associated with pulmonary vasodilatation and a decrease in pulmonary vascular
resistance to accommodate the increase in cardiac output. If production of NO is
impaired in patients with chronic congestive cardiac failure (CCF), this might
contribute to their exercise intolerance. PATIENTS AND METHODS: We quantified NO
production (V NO) in 12 patients with chronic stable CCF and 12 controls, at rest
and during incremental cardiopulmonary exercise on a treadmill, and at a later
date during constant workload exercise. RESULTS: Patients had reduced V NO
compared with controls during incremental exercise [381 (180) vs. 777 (275) nL
min-1; mean (SD); P < 0.0001] but at constant workload V NO was similar between
the two groups [353 (124) vs. 389 (189) nL min-1; P = 0.25]. Plasma levels of
nitrate, the stable end-product of NO production, were significantly higher in
patients [resting value 46.1 (21.6) vs. 23.0 (10.0) microM; P = 0.004] and were
not influenced by exercise. CONCLUSION: Impaired NO-mediated pulmonary
vasodilatation does not appear to contribute to exercise limitation in CCF.
Alternatively, the lower NO production observed during maximal exercise in the
patient group compared with controls may reflect a reduced incremental response
of a system that is already abnormally activated in heart failure.
PMID- 10691994
TI - Platelet factor 4 and beta-thromboglobulin in inflammatory bowel disease and
giant cell arteritis.
AB - BACKGROUND: As platelet factors are important in the inflammatory response, we
examined the course of platelet factor 4 and beta-thromboglobulin in relation to
disease activity in inflammatory bowel disease and in giant cell arteritis.
PATIENTS AND METHODS: In a prospective study, the platelet count, platelet factor
4 and beta-thromboglobulin were measured in 20 patients with Crohn's disease, 18
with ulcerative colitis and 19 with giant cell arteritis, during active and
inactive disease, as well as in 51 controls without inflammation. RESULTS:
Platelet counts were significantly higher in active vs. inactive Crohn's disease,
ulcerative colitis and giant cell arteritis. Levels of platelet factor 4 and beta
thromboglobulin were significantly higher in active inflammatory bowel disease
and giant cell arteritis, as well as in inactive inflammatory bowel disease and
giant cell arteritis, than in the non-inflammatory controls. A positive
correlation was found between the Crohn's disease activity index and the platelet
count, platelet factor 4 and beta-thromboglobulin. Also, a positive correlation
was found between the ulcerative colitis activity index and beta-thromboglobulin.
However, even after 12 months of follow-up, in Crohn's disease and ulcerative
colitis the mean levels of platelet factor 4 and beta-thromboglobulin were
significantly higher than the levels of the controls. CONCLUSION: Platelet
factors were correlated with inflammatory bowel disease activity. Levels of
platelet factor 4 and beta-thromboglobulin, however, were markedly raised for a
long time in clinically inactive inflammatory bowel disease, which might point to
a pre-thrombotic state of disease.
PMID- 10691995
TI - A metabolic syndrome of hypertension, hyperinsulinaemia and hypercholesterolaemia
in the New Zealand obese mouse.
AB - BACKGROUND: New Zealand obese (NZO) mice exhibit a polygenic obesity associated
with hyperinsulinaemia and hyperglycaemia. Here we show that the strain presents
additional features of a metabolic syndrome, i.e. elevated blood pressure, serum
cholesterol and serum triglyceride levels. MATERIALS AND METHODS: A back-cross
model of NZO mice with the lean Swiss Jackson Laboratory (SJL) strain was
established in order to investigate further the correlation between hypertension,
obesity, serum insulin and hyperglycaemia. RESULTS: Systolic blood pressure was
significantly elevated at 6 weeks of age and appeared to parallel the weight gain
of the animals. Serum insulin levels, presumably reflecting insulin resistance,
and systolic blood pressure values were significantly correlated with the body
mass index (r2 = 0.707 and 0.486, respectively) in the back-cross mice. In
contrast, blood pressure was only weakly correlated with serum insulin (r2 =
0.288) in non-diabetic mice, and was independent of serum insulin levels in
diabetic animals. CONCLUSION: The data are consistent with the concept that
hypertension and insulin resistance are a characteristic consequence of the
genetic constellation leading to obesity in the NZO strain, and that these traits
reflect related mechanisms. It appears unlikely, however, that hypertension is a
direct consequence of hyperinsulinaemia.
PMID- 10691996
TI - Effect of tauroursodeoxycholic acid on bile acid-induced apoptosis in primary
human hepatocytes.
AB - BACKGROUND/AIMS: The accumulation of endogenous bile acids contributes to
hepatocellular damage during cholestatic liver disease. To evaluate the potential
role of apoptotic cell death due to increased concentrations of bile acids,
primary human hepatocytes were treated with hydrophobic and hydrophilic bile
acids. Because the Fas receptor-ligand system may mediate apoptosis in human
liver cells, the effect of toxic bile acids on hepatocellular Fas receptor
expression was evaluated. MATERIALS AND METHODS: Primary human hepatocytes were
incubated with 50 and 100 microM glycochenodeoxycholic acid (GCDCA) and co
incubated with equimolar concentrations of tauroursodeoxycholic acid (TUDCA). To
evaluate cytolytic and apoptotic effects, morphological alterations,
hepatocellular enzyme release, nuclear DNA fragmentation and hepatocellular Fas
receptor expression were evaluated. RESULTS: Apoptotic cell death was
significantly increased after exposure to 50 microM GCDCA. Bile acid-induced
apoptosis was not accompanied by hepatocellular Fas receptor overexpression.
Tauroursodeoxycholic acid reduced apoptosis, as indicated by a significant
reduction of oligonucleosomal DNA cleavage. Fas receptor expression was not
significantly affected by tauroursodeoxycholic acid. At higher concentrations,
direct cytolytic cell destruction was observed. CONCLUSION: Primary human
hepatocytes represent a suitable model to study bile acid-induced apoptotic cell
death. In these hepatocytes, already low bile acid concentrations might induce
apoptotic cell death, which is not triggered by hepatocellular Fas receptor
overexpression. Apoptotic DNA fragmentation was significantly reduced by co
incubation with tauroursodeoxycholic acid. The reduction of bile acid-induced
apoptosis by ursodeoxycholic acid and its conjugates may contribute to the
beneficial effects of these hydrophilic bile acids used for medical treatment of
several cholestatic liver diseases.
PMID- 10691997
TI - Speed of sound, bone mineral density and bone strength in oophorectomized rats.
AB - BACKGROUND: The aim of this study was to determine the sensitivity of bone
mineral density (BMD), ultrasounds (SOS) and resistance to torsion (T) to detect
experimental osteopenia induced in rats 3 and 6 months after ooforectomy.
MATERIALS AND METHODS: Seventy-four rats were used, divided into four groups,
ooforectomized rats analysed 3 and 6 months after the operation and their
respective control groups, in which BMD (Hologic QDR 1000 S/N 277), SOS (DBM
Sonic 1200) and T (adapted test machine) were determined in the right femur.
RESULTS: The results of the three techniques distinguished the ooforectomized
groups from the controls, both 3 and 6 months after the ooforectomy, obtaining
more significant differences with BMD (P = 0.0006, P = 0. 001, respectively) than
SOS and T, where a significance of only P = 0.05 was obtained. In the correlation
study among the three techniques, a significant correlation was observed between
BMD and SOS (r = 0.39, P = 0.0008), as well as between BMD and T (r = 0.31, P =
0.03). However, significance was not observed between the SOS and T tests.
CONCLUSION: In the study of sensitivity and specificity of the techniques used to
detect the osteopenia caused by the ooforectomy, by means of calculation of the
area under the receiver operation characteristic (ROC) curve, it was proven that
although the three techniques distinguished between the two analysed populations,
BMD presented an area under the ROC curve that was superior (0.87, 0.85) to that
obtained with SOS (0.73, 0.67) and T (0.73, 0.68), both 3 and 6 months after the
operation.
PMID- 10691998
TI - Potential aetiological factors concerning the development of osteonecrosis of the
femoral head.
AB - BACKGROUND: The aetiology and pathogenesis of non-traumatic osteonecrosis (ON) of
the femoral head have not been fully elucidated. The present study was conducted
to evaluate the possible correlation of relevant haematological and biochemical
factors with the development of ON. PATIENTS AND METHODS: Our investigation
consisted of measurement of haematological indices and assessment of the
biochemical and lipid profile of a study population of 68 patients with non
traumatic ON of the femoral head and 36 healthy controls. The disease was
considered idiopathic in 17 and secondary in 51 patients. RESULTS: There were no
statistically significant differences in the parameters measured among the
idiopathic ON, secondary ON and control groups, except for globulins alpha1,
alpha2 and beta, which were significantly increased in both patient groups, and
apolipoprotein B (Apo B), which was increased in patients with idiopathic disease
compared with the control group. Both patient groups presented increased von
Willebrand factor (VWF) and lipoprotein (a) [Lp(a)] levels and decreased protein
C and S concentrations, but without statistical significance. However, both
patient groups exhibited a greater proportion of abnormal values of any of these
parameters, in 58.9% of the idiopathic and in 62.7% of the secondary ON patients,
compared with 8.3% of the controls. CONCLUSION: Our study underlines the
potential association of abnormal values of protein C, protein S, VWF and Lp(a)
with ON. To our knowledge this is the first reported association of VWF with the
disease. The majority of both idiopathic and secondary ON patients in our series
exhibits a thrombotic potential that adds further support to the postulation that
intravascular coagulation is a major pathogenetic mechanism leading to the
disease.
PMID- 10691999
TI - Expression of keratinocyte growth factor and its receptor in colorectal cancer.
AB - BACKGROUND AND AIMS: The mesenchymal derived keratinocyte growth factor
stimulates growth, differentiation and migration of intestinal epithelial cells.
In the human gastrointestinal tract an overexpression of this growth factor has
been reported in inflammatory bowel disease and pancreatic cancer. In the present
study we investigated expression patterns of keratinocyte growth factor and
receptor in normal and neoplastic colonic mucosa and in metastases. Furthermore,
biological effects on normal intestinal and colorectal cancer cell lines were
determined. MATERIALS AND METHODS: Expression patterns were analysed at the mRNA
level by reverse transcription-polymerase chain reaction (RT-PCR) and at the
protein level by Western blotting. Localization of ligand and receptor in normal
intestinal mucosa and cancer tissue was investigated by immunohistochemistry.
Mitogenic effects of keratinocyte growth factor were assayed by [3H]thymidine
incorporation in normal (Intestine-407, IEC-6, IEC-18) and colorectal cancer cell
lines (Colo320, LoVo, SW403, SW707). RESULTS: mRNA expression of keratinocyte
growth factor and receptor was detected in the majority of normal and cancer
samples without significant alterations. At the protein level keratinocyte growth
factor expression did not differ between normal and malignant specimens, whereas
protein expression of the receptor was increased up to twofold in well- to
moderately differentiated colorectal cancers. DNA synthesis was significantly
stimulated by keratinocyte growth factor in all three normal intestinal cell
lines, whereas this growth factor did not significantly alter the [3H]thymidine
incorporation in the colorectal cancer cell lines. CONCLUSION: Keratinocyte
growth factor and its receptor were detected in the majority of samples from
normal and neoplastic colonic mucosa, with an overexpression of the receptor seen
in the more differentiated tumour samples. Keratinocyte growth factor is a strong
mitogen for normal intestinal cells, whereas it is less effective in neoplastic
cells.
PMID- 10692000
TI - Lymphocyte responses following open and minimally invasive thoracic surgery.
AB - BACKGROUND: Immunosuppression associated with surgery may predispose to increased
tumour growth or recurrence. Lymphocytes are central components of the immune
network, signalling specific and non-specific responses in tumour
immunosurveillance. This study was therefore designed to compare the effects of
minimally invasive and conventional approaches to major thoracic surgery on
lymphocyte populations and oxidative activity. PATIENTS AND METHODS: The effects
of conventional and minimally invasive video-assisted thoracic surgery (VATS) on
the numbers and types of circulating lymphocytes and on lymphocyte oxidation were
compared in a prospective randomized study of 41 patients undergoing lobectomy
for peripheral bronchogenic carcinoma. Blood taken pre-operatively and on days 2
and 7 post-operatively was analysed for T (CD4, CD8), B (CD19) and natural killer
(NK) (CD56, CD16) cell counts and for lymphocyte oxidative activity. Leucocyte
numbers were compared with pre-surgical values and oxidative rate with healthy
donor controls. RESULTS: Lymphocyte counts fell after surgery; VATS was
associated with less effect on circulating T (CD4) cells at 2 days and on NK
lymphocytes at 7 days post-surgery. Lymphocyte oxidation was less suppressed in
the VATS group 2 days after surgery. In general, post-surgical changes in key
cells of cellular immunity were smaller in the VATS group, and recovery to normal
levels was more rapid. CONCLUSION: The degree of invasiveness of thoracic surgery
may influence the extent of immunosuppression in patients undergoing pulmonary
lobectomy for pulmonary neoplasm.
PMID- 10692001
TI - Assessment of bilirubin toxicity to erythrocytes. Implication in neonatal
jaundice management.
AB - BACKGROUND: Neonatal hyperbilirubinaemia remains one of the most common clinical
conditions requiring therapeutic intervention. Nevertheless, reliable indicators
of bilirubin toxicity are still missing. This prompted us to investigate (a) the
progression of cytotoxic events produced by increasing concentrations of
bilirubin; (b) the relevance of the membrane lipid package on bilirubin binding
to erythrocytes; and (c) the reliability of chloroform extraction compared with
albumin extraction to evaluate erythrocyte-bound bilirubin and cytotoxicity.
MATERIALS AND METHODS: Morphological alterations, free bilirubin, erythrocyte
bound bilirubin (albumin- and chloroform-extractable), haemolysis and membrane
released lipids, were determined in human erythrocytes at 4 degrees C or 37
degrees C, after 4 h incubation at pH 7.4, with increasing molar ratios of
bilirubin to albumin (0.5-5). The reversibility of cytotoxicity by albumin
washing was assessed by morphological analysis. RESULTS: Decreased free
bilirubin, lower erythrocyte-bound bilirubin concentration by albumin extraction
(superficial/non-aggregated bilirubin) and higher values by chloroform extraction
(deep/aggregated bilirubin) were observed for 37 degrees C vs. 4 degrees C, at
molar ratios > 1. Echinocytosis increased with bilirubin concentration and
temperature and was not fully reversed by albumin washing. Haemolysis was already
significant at a molar ratio of 1, and was enhanced by temperature at molar
ratios 3 and 5 (P < 0.01). The loss of membrane lipids was remarkable at molar
ratios > or = 0.5, both at 4 degrees C and 37 degrees C (P < 0.01), although
correlation with bilirubin concentration was only significant at 37 degrees C (r
= 0.971; P < 0.01). CONCLUSIONS: These results suggest that increased lipid
fluidity and high bilirubin concentrations promote membrane bilirubin
translocation and toxicity. They also show that albumin is not able to displace
the bilirubin located deeply or aggregated within the membrane, which in turn is
removed by chloroform. Accordingly, chloroform-extractable rather than albumin
extractable bilirubin is a more accurate parameter to assess erythrocyte-bound
bilirubin during severe hyperbilirubinaemia.
PMID- 10692002
TI - Non-transferrin-bound iron is present in serum of hereditary haemochromatosis
heterozygotes.
AB - BACKGROUND: Hereditary haemochromatosis (HH) is a common autosomal recessive
disease. Recently, HH heterozygosity has been identified as an independent risk
factor for myocardial infarction and cardiovascular mortality. Iron may play an
important role in atherogenesis by catalyzing peroxidation of low-density
lipoprotein (LDL), an essential step in atherogenesis. In iron overload
conditions, non-transferrin-bound iron (NTBI) is found in serum, which can
catalyze lipid peroxidation. We investigated whether sera of HH heterozygotes
contain more NTBI than sera of normal controls. METHODS: In 27 treated HH
homozygotes, 22 HH heterozygotes and 17 healthy control subjects, conventional
parameters of iron status (serum iron, transferrin saturation, serum ferritin)
were measured. NTBI was detected using HPLC after addition of nitrilotriacetic
acid and pretreatment with cobalt. RESULTS: The conventional parameters of iron
status were similar in the HH heterozygous group and the control group. NTBI was
significantly higher in homozygotes compared to heterozygotes (1.79 micromol L-1
vs. 0.51 micromol L-1, 95% CI of the difference = 0.6-1.95, P < 0.001), and
controls (1.79 micromol L-1 vs. - 0.3 micromol L-1, 95% CI of the difference =
1.36-2.81, P < 0.001). The difference in NTBI between the heterozygous subjects
and control subjects was also significant (0.51 micromol L-1 vs. - 0. 3 micromol
L-1, 95% CI of the difference = 0.05-1.57, P < 0.05). CONCLUSION: Phlebotomy
treated HH homozygotes maintain a high and potentially harmful serum NTBI. HH
heterozygotes have a higher serum NTBI than normal controls. The reported
increased risk of cardiovascular events in heterozygous haemochromatosis may be
explained by NTBI-catalyzed LDL peroxidation.
PMID- 10692003
TI - Decreased vitamin A levels in common variable immunodeficiency: vitamin A
supplementation in vivo enhances immunoglobulin production and downregulates
inflammatory responses.
AB - BACKGROUND: Vitamin A has a broad range of immunological effects, and vitamin A
deficiency is associated with recurrent infections. Common variable
immunodeficiency (CVI) is a group of B-cell deficiency syndromes with impaired
antibody production and recurrent bacterial infections as the major
manifestations, but the immunological dysfunctions may also include T cells and
macrophages. In the present study we examined the possible role of vitamin A
deficiency in CVI. PATIENTS AND METHODS: We analysed plasma vitamin A levels in
20 CVI patients and 16 controls, and examined the relationships between vitamin A
and clinical, immunological and metabolic parameters in CVI. In the six CVI
patients with the lowest vitamin A levels we also studied the effect of vitamin A
supplementation in vivo on several immunological functions in these patients.
RESULTS: (i) The majority of CVI patients had decreased vitamin A levels compared
with healthy controls, as found in both cross-sectional and longitudinal testing.
(ii) Low vitamin A levels were associated with the occurrence of chronic
bacterial infections and splenomegaly as well as high neopterin levels. Decreased
levels of carrier protein and malabsorption were not observed. (iii) Vitamin A
supplementation in patients with low vitamin A levels resulted in increased
interleukin-10 (IL-10) and decreased tumour necrosis factor-alpha (TNFalpha)
levels, as found in both plasma and monocyte supernatants, possibly favouring
anti-inflammatory net effects. (iv) Vitamin A supplementation in vivo also
enhanced anti-CD40-stimulated IgG production, serum IgA levels and
phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cell (PBMC)
proliferation. CONCLUSION: A considerable subgroup of CVI patients appears to be
characterized by low vitamin A levels. Our findings support a possible role for
vitamin A supplementation in CVI, perhaps resulting in enhanced immunoglobulin
synthesis and downregulated inflammatory responses.
PMID- 10692004
TI - Encapsulated fish oil enriched in alpha-tocopherol alters plasma phospholipid and
mononuclear cell fatty acid compositions but not mononuclear cell functions.
AB - BACKGROUND: Several studies have reported that dietary fish oil (FO)
supplementation alters cytokine production and other functional activities of
peripheral blood mononuclear cells (PBMC). However, few of these studies have
been placebo controlled and few have related the functional changes to
alterations in PBMC fatty acid composition PATIENTS AND METHODS: Healthy subjects
supplemented their diets with 9 g day-1 of encapsulated placebo oil (3 : 1 mix of
coconut and soybean oils), olive oil (OO), safflower oil (SO), evening primrose
oil (EPO) or FO [providing 2.1 g eicosapentaenoic acid (EPA) plus 1.1 g
docosahexaenoic acid (DHA) per day] for 12 weeks; the capsules also provided 205
mg alpha-tocopherol per day. Blood was sampled at 4-weekly intervals and plasma
and PBMC prepared. Plasma phospholipid and PBMC fatty acid composition, plasma
alpha-tocopherol and thiobarbituric acid-reactive substance concentrations,
plasma total antioxidant capacity, the proportions of different PBMC subsets, the
proportions of PBMC expressing the adhesion molecules CD2, CD11b and CD54, and
PBMC functions (lymphocyte proliferation, natural killer cell activity, cytokine
production) were measured. All measurements were repeated after a 'washout'
period of 8 weeks. RESULTS: The placebo, OO and SO capsules had no effect on
plasma phospholipid or PBMC fatty acid composition. The proportion of dihomo
gamma-linolenic acid in plasma phospholipids was elevated in subjects taking EPO
and was decreased in subjects taking FO. There was no appearance of gamma
linolenic acid in the plasma phospholipids or PBMC in subjects taking EPO. There
was a marked increase in the proportion of EPA in the plasma phospholipids (10
fold) and PBMC (four-fold) of subjects taking FO supplements; this increase was
maximal after 4 weeks of supplementation. There was an increase in the proportion
of DHA in plasma phospholipids and PBMC, and an approximately 20% decrease in the
proportion of arachidonic acid in plasma phospholipids and PBMC, during FO
supplementation. Plasma concentrations of alpha-tocopherol were significantly
elevated during supplementation in all subjects and returned to baseline values
after the washout period. There were no effects of supplementation with any of
the capsules on total plasma antioxidant activity or plasma thiobarbituric acid
reactive substances or on the proportion of different PBMC subsets, on the
proportion of PBMC expressing adhesion molecules, on natural killer cell
activity, on the proliferation of mitogen-stimulated whole blood cultures or
PBMC, or on the ex vivo production of a range of cytokines by whole blood
cultures or PBMC cultures stimulated by either concanavalin A or
lipopolysaccharide. CONCLUSION: Supplementation of the diet with 3.2 g EPA plus
DHA per day markedly alters plasma phospholipid and PBMC fatty acid compositions.
The lack of effect of FO upon PBMC functions may relate to the level of alpha
tocopherol included in the supplements.
PMID- 10692005
TI - The evolutionary ecology of resistance to parasitoids by Drosophila.
AB - Parasitoids are the most important natural enemies of many insect species. Larvae
of many Drosophila species can defend themselves against attack by parasitoids
through a cellular immune response called encapsulation. The paper reviews recent
studies of the evolutionary biology and ecological genetics of resistance in
Drosophila, concentrating on D. melanogaster. The physiological basis of
encapsulation, and the genes known to interfere with resistance are briefly
summarized. Evidence for within- and between-population genetic variation in
resistance from isofemale line, artificial selection and classical genetic
studies are reviewed. There is now firm evidence that resistance is costly to
Drosophila, and the nature of this cost is discussed, and the possibility that it
may involve a reduction in metabolic rate considered. Comparative data on
encapsulation and metabolic rates across seven Drosophila species provides
support for this hypothesis. Finally, the possible population and community
ecological consequences of evolution in the levels of host resistance are
examined.
PMID- 10692006
TI - Spatial models for hybrid zones.
AB - We introduce a spatially explicit model of natural hybrid zones that allows us to
consider how patterns of allele frequencies and linkage disequilibria change over
time. We examine the influence of hybrid zone origins on patterns of variation at
two loci, a locus under selection in a two-patch environment, and a linked
neutral locus. We consider several possible starting conditions that represent
explicit realizations of two alternative scenarios for hybrid zone origins:
primary intergradation and secondary contact. Our results indicate that in some
circumstances, differences in hybrid zone origins will result in substantially
different patterns of variation that may persist for thousands of generations.
Our conclusions are generally similar to those previously derived from partial
differential equations, but there are also some important differences.
PMID- 10692007
TI - Reduction in fitness of flea beetles which are homozygous for an autosomal gene
conferring resistance to defences in Barbarea vulgaris.
AB - Major resistance genes are present in Danish flea beetle (Phyllotreta nemorum)
populations, enabling the beetles to utilize a defended plant, Barbarea vulgaris
ssp. arcuata, as a host plant, whereas this plant is unsuitable for beetles
lacking the resistance genes. Two lines of beetles carrying a resistance gene
have been established which are near-isogenic with a susceptible line. Larval
survival of offspring from crosses between flea beetles carrying resistance genes
and susceptible beetles, tested in bioassays on the defended B. vulgaris, and sex
ratios of the survivors, were consistent with the presence of a dominant,
autosomal resistance gene in each of the lines. An attempt to produce pure
breeding lines for the autosomal genes revealed that beetles that are homozygous
for the resistance gene suffer a high mortality. This result was repeatable for
both lines, and when both resistant males and females were used in the crosses.
The high mortality was also independent of the plant (defended B. vulgaris or
suitable radish) on which the beetles were reared. The results suggest that the
time of death of homozygous resistant beetles is variable. The spread and
maintenance of resistance genes in flea beetle populations are discussed.
PMID- 10692008
TI - Absence of single-locus complementary sex determination in the braconid wasps
Asobara tabida and Alysia manducator.
AB - In species with single-locus complementary sex determination (sl-CSD), sex is
determined by multiple alleles at a single locus. In the haplodiploid
Hymenoptera, sl-CSD results in females, if individuals are heterozygous at the
sex locus, and in males, if individuals are hemizygous (haploid males) or
homozygous (diploid males). Several hymenopteran species have been shown to have
sl-CSD, but in several others sl-CSD is absent and the phylogenetic distribution
remains unclear. In the family Braconidae, all four species tested so far were
shown to possess sl-CSD. In this study, inbreeding experiments were used to test
for the presence of sl-CSD in two species belonging to a subfamily of the
Braconidae, Asobara tabida and Alysia manducator (Alysiinae). In both species
inbreeding experiments showed no difference in brood size or sex ratio compared
to the (outbred) control group. Furthermore, the sex ratios found in the
inbreeding treatment differed significantly from the sex ratios expected under sl
CSD. Therefore, we conclude that sl-CSD is absent in these species. This study is
the first to show the lack of sl-CSD in species of the Braconidae family and that
hymenopteran sex-determining mechanisms can vary, even within a family.
PMID- 10692009
TI - Phylogenetic information in inter-SINE and inter-SSR fingerprints of the
artiodactyla and evolution of the bov-tA SINE.
AB - Various interspersed repeated sequences and elements (IRSs) can be utilized to
generate PCR-based multilocus fingerprint profiles by amplifying the interelement
segments, using primers matching the elements themselves. We assessed the utility
of inter-IRS fingerprinting in phylogenetic comparisons among six artiodactyl
species using several primers derived from two abundant genomic components: the
Bov-tA short interspersed nuclear elements (SINEs) and simple sequence repeats or
microsatellites (SSRs). Character- and distance-based analyses of the fingerprint
data produced trees conforming to the established phylogenetic relationships of
species. The strength of phylogenetic signal from different primers varied;
combining data from different experiments resulted in robust trees. Within the
Cervidae, the hierarchical relationship [(Odocoileus, Rangifer) Alces] was
strongly supported. Both methods appear useful tools for systematic studies at
time scales <30 Myr. To elucidate the material basis of inter-SINE fingerprints,
we obtained the first sequences of the 'bovid' Bov-tA element also from two
cervids (reindeer and white-tailed deer) and analysed their relationship to a
number of paralogous bovid elements. The differences among sequences, both intra-
and interspecific, were relatively high (mean 18.5%); the sequences showed no
clear clustering with the species from which they had been isolated. Most
individual elements probably date back to the cervid-bovid ancestor >25 Myr ago,
which is in line with the observed fingerprint distributions.
PMID- 10692010
TI - Chromosomal localization of cotransformed transgenes in the hexaploid cultivated
oat Avena sativa L. using fluorescence in situ hybridization.
AB - Fluorescence in situ hybridization (FISH) was used to localize two transgenes
(gus and bar), carried on plasmids pACT-1F and pUBA, respectively, on mitotic
metaphase squashes of T1 plants of the cultivated hexaploid oat Avena sativa L.
cotransformed by microprojectile bombardment of embryogenic callus. Among the
eight progeny analysed by FISH in each of two lines, we detected plants null,
hetero- and homozygous for the two genes in one line, and plants null and
heterozygous for the two genes in the other line. Our results demonstrated that
in the two independent transformation events, the gus and bar genes had inserted
in the same position relative to each other. In each transformation event, the
insertions occurred on D satellite (SAT) chromosomes bearing a C genome
translocation.
PMID- 10692011
TI - Do Wolbachia influence fecundity in Nasonia vitripennis?
AB - This paper reports the influence of a vertically transmitted symbiont, Wolbachia,
on host fitness in the parasitic wasp, Nasonia vitripennis. We measured
fecundities of uninfected strains and strains infected with either two Wolbachia
variants (wAv,wBv) or one (wAv or wBv). Preliminary tests suggested that double
infected females produce more offspring on average than uninfected females.
However, further studies failed to yield consistent fitness effects. To control
for host genetic effects, the genotype of the double-infected and uninfected
strain was 'replaced' with three different host genetic backgrounds by
introgression. Contrary to previous results, we found no convincing evidence for
positive fitness effects of Wolbachia in Nasonia vitripennis, once host genetic
background was controlled for. It can be concluded that under the experimental
design used here, the fecundity effects associated with Wolbachia in N.
vitripennis are small or absent.
PMID- 10692012
TI - MCE activities and malathion resistances in field populations of the australian
sheep blowfly (Lucilia cuprina).
AB - Malathion resistance has been shown to be the result of a single point mutation
in the LcalphaE7 gene in four independently isolated chromosomes of Lucilia
cuprina. The resultant amino acid substitution specifies high malathion
carboxylesterase (MCE) activity. We have assayed MCE activities and resistance to
malathion in three sets of field-derived samples, two sets of isogenic lines and
five mass populations, and show that resistance to malathion in these samples is
associated with high MCE activity in both sets of isogenic lines and four of the
five mass populations. Additional mechanisms contributing to MCE activity or
malathion resistance may be present in one of the mass populations. A second
point mutation in LcalphaE7 is responsible for conferring diazinon resistance by
encoding an increased organophosphate (OP) hydrolase activity. We also assayed
diazinon resistances from the same three samples and show that diazinon and
malathion resistances were in complete disequilibrium, with two exceptions. One
exception involves the mass population with additional resistance mechanism(s)
and the other involves three isogenic lines that are resistant to both
insecticides. The molecular data for these lines suggest that they carry a
duplication of the LcalphaE7 gene.
PMID- 10692013
TI - Quantitative genetics of female choice in an ultrasonic pyralid moth, Achroia
grisella: variation and evolvability of preference along multiple dimensions of
the male advertisement signal.
AB - The mating system of Achroia grisella (Lepidoptera: Pyralidae) is characterized
by male ultrasonic advertisement signalling to which females orientate. Although
males provide no direct, somatic benefits to their mates, females prefer males
whose signal characters are more exaggerated than the population means. Previous
studies showed that the signal characters influencing mate attraction are highly
repeatable and heritable. We measured the phenotypic and additive genetic
variances (heritability) of female preference in A. grisella, as this additive
genetic variance is one of the genetic assumptions of indirect models of sexual
selection. We determined the preference index of female A. grisella by repeated
phonotaxis trials in which a choice of simulated male signals was presented.
These playback experiments showed that female preference indices varied but were
repeatable within individuals. Specifically, females differ in the relative
importance of the several signal characters during mate assessment. A subsequent
half-sib breeding design revealed an amount of additive genetic variance for the
female preference index (h(s)2 = 0.212, SE = 0.1347, P = 0.0611; CVA = 0.1826).
Our study highlights the importance of careful preparation of test signals and
experimental design for quantifying individual variation in (female) preference
along multiple signal dimensions.
PMID- 10692014
TI - Virulence and molecular diversity of parthenogenetic root-knot nematodes,
Meloidogyne spp.
AB - Root-knot nematodes (RKN) are sedentary endoparasites causing severe damage to a
wide variety of crops, including tomato. Among them, the parthenogenetic species
Meloidogyne arenaria, M. incognita and M. javanica are of particular economic
importance. The genetic diversity and relationships of 17 populations belonging
to these three major species, either avirulent or virulent against the tomato Mi
resistance gene, were investigated in order to determine whether (a)virulence of
the nematodes could be related to their molecular fingerprints. Genomic
polymorphisms between populations were assessed by using amplified fragment
length polymorphism (AFLP) markers, and data were treated by means of a multiple
correspondence analysis. A total of 1550 polymorphic amplified DNA fragments were
identified and used to compute the relationships between the populations. As
expected, the three RKN species were clearly distributed into distinct groups,
but combination of data for virulence phenotypes and DNA markers showed that
clustering of populations was not associated with their (a)virulence against the
tomato Mi resistance gene. Such a lack of correlation indicates that most of the
observed DNA polymorphism is independent of virulence, which is presumably under
host selection. This result demonstrates that virulent populations do not share a
common origin, and strongly suggests that they might have appeared late after the
establishment of these clonal lineages, as the result of independent mutational
events.
PMID- 10692015
TI - Reproductive characteristics of the flower-breeding Drosophila hibisci Bock
(Drosophilidae) in eastern Australia: within-population genetic determinants of
ovariole number.
AB - Genetic variation for ovariole number in the flower-breeding Drosophila hibisci
was studied within populations obtained from three separate sites in the centre
of the species distribution along the east coast of Australia. Heritability for
ovariole number (adjusted for body size), derived from isofemale lines from each
site, was estimated to be h2+/-SE = 0.564+/-0.160. The variance of ovariole
number within sites (sigma2(within) = 2.039) was comparable to the variance
between sites (sigma2(between) = 2.048) obtained from an earlier study of
populations sampled over 14 degrees of latitude. Two isofemale lines (from within
one site) that differed by an average of 4.6 ovarioles were used to generate F1,
F2 and backcross generations. Analysis of mean ovariole number for these
generations showed that only additive gene effects were important and that
dominance, digenic epistasis and maternal effects were not significant. This
within-population result contrasted with earlier results between populations that
revealed additive and digenic epistasis for the same trait. High heritability
within populations and the relatively large within-population variation for
ovariole number suggest that substantial microhabitat variation is influencing
this fitness-related trait.
PMID- 10692016
TI - Are the same genes responsible for intra- and interspecific variability for sex
comb tooth number in Drosophila?
AB - The identification of genes contributing to speciation has the potential to
provide important insights into the mechanisms of evolution. One of the most
interesting unresolved puzzles is the relationship between intraspecific
variability in morphological traits and their interspecific divergence.
Intraspecific polymorphisms without major detrimental side-effects may serve as a
substrate for selection response during speciation. The same quantitative trait
loci (QTLs) may, then, account for the trait variability both within and between
species. In contrast, the vast majority of intraspecific variants could be
deleterious mutations that have not yet been selected out. In this case
intraspecific variation would not ultimately generate interspecific trait
differences. In previous work, QTLs responsible for morphological differences
between animal species, including those for the secondary sexual trait sex comb
tooth number, have been mapped with the resolution of chromosome segments. Here,
we mapped QTLs for which alleles segregated between two laboratory lines of
Drosophila melanogaster. The two QTLs identified mapped to the X chromosome and
accounted for only 8% of the between-line differences, implying that a large
number of small-effect genes modify sex combs. One intraspecific QTL mapped to
the same interval as the QTL for interspecific differences between D. simulans
and D. mauritiana. Whether or not these effects result from the same genes
requires further examination.
PMID- 10692017
TI - Differences in genetic structure between two Japanese beech (Fagus crenata Blume)
stands.
AB - To examine the effects of forest cutting on within-population genetic structure,
the genetic structure and variability of two Japanese beech (Fagus crenata Blume)
stands with contrasting histories in relation to cutting were investigated. Six
hundred and sixty beech trees, covering two hectares in total, were mapped and
genetically analysed using nine isozyme loci encoding eight enzyme systems. The
proportion of polymorphic loci, the average number of alleles per locus, the
effective number of alleles per locus, the expected heterozygosity and the
observed heterozygosity were 78, 3.3, 1.31, 0.200 and 0.189, respectively, in a
secondary stand (designated AK) cut during the 1920s. Corresponding figures were
78, 3.3, 1.33, 0.203 and 0.193, respectively, in a primary stand designated KU.
The inbreeding coefficient and the grand mean of the number of alleles in common
(NAC) were 0.055 and 1.684 in AK, and 0. 042 and 1.649 in KU, respectively. The
genetic variability was slightly but significantly lower in AK. The genetic
structure of the two stands was strikingly different. The proportions of
positively significant Moran's I and SND values found in the shortest distance
class were 0.86 and 0.38 for AK, and 0.14 and 0.29 for KU, respectively.
Furthermore, significant linkage disequilibrium was observed in AK, but none at
all in KU. To examine which, if any, differences in the genetic structure would
be likely to influence succeeding generations, we simulated a self-thinning
process. The simulation suggested that reduced genetic variability and linkage
disequilibrium would have significant influence in the AK stand for several
generations.
PMID- 10692018
TI - The effect of ecological factors on the mating system of a South American shrub
species (Helicteres brevispira).
AB - Mating systems are influenced by several ecological factors, including plant
density, number of flowers per plant, and pollinator movements. In this study, we
investigated the simultaneous effects of these three factors on the mating system
of a self-compatible Brazilian shrub species: Helicteres brevispira St. Hil.
Outcrossing rate is directly correlated with plant density. Changes in the number
of flowers per plant affect outcrossing rate through their effect on the density
of flowers. Variation in foraging behaviour of hummingbird pollinators is a
consequence of the interaction between plant density and number of flowers per
plant. Territorialist pollinators are common in high density areas but visit few
flowers on each plant, thereby promoting outcrossing. In areas of low plant
density, trapliners and rare territorialists visit several flowers per plant,
thus increasing selfing. Our results indicate that outcrossing rate is a dynamic
parameter, with the extent of variation depending on a number of ecological
factors. In successional species such as those in the genus Helicteres,
demographic changes may be accompanied by alterations in mating system
parameters, with concomitant effects on the genetic structure of populations.
PMID- 10692019
TI - MtDNA variation in Apis cerana populations from the Philippines.
AB - The cavity-nesting honeybee Apis cerana occurs in Asia, from Afghanistan to China
and from Japan to southern Indonesia. Based on morphometric values, this species
can be grouped into four subspecies: A. c. cerana, A. c. indica, A. c. japonica
and A. c. himalaya. In order to analyse the geographical variability of A. c.
indica from the Philippine Islands, 47 colonies from different locations in three
of the larger islands (Mindanao, Luzon and Palawan) and four of the Visayan
Islands (Panay, Negros, Cebu and Leyte) were studied. Genetic variation was
estimated by restriction and sequence analysis of PCR-amplified fragments of the
tRNAleu-COII region. We found four different haplotypes, Ce1, Ce2, Ce3 and Ce4,
that discriminate among the bee populations from different islands. The Ce1
haplotype is present in Mindanao and Visayan Islands, Ce2 is restricted to Luzon,
and both Ce3 and Ce4 are only present in Palawan. Phylogenetic analysis of the
sequences shows a great intraspecific variability, is in accordance with the
geological history of these islands and partially agrees with some previous
morphological and molecular studies.
PMID- 10692020
TI - Surgical pathology of renal epithelial neoplasms: recent advances and current
status.
PMID- 10692021
TI - Metaplastic carcinoma of the breast arising within complex sclerosing lesion: a
report of five cases.
AB - AIMS: This study presents a series of five cases in which metaplastic carcinoma,
predominantly low-grade adenosquamous carcinoma, of the breast is seen arising
within a background of a complex sclerosing lesion. This association has been
recognized previously but has not been documented in detail. This study describes
the characteristics of the components present in each case and discusses the
existing literature. This observation adds further evidence to support an
association between some types of invasive breast carcinoma and sclerosing
lesions of the breast. METHODS AND RESULTS: Four of these cases were received as
referral cases for opinion. The fifth was received as part of the routine
surgical workload within our own institution. Two patients presented following
mammographic screening and three symptomatically; their mean age was 62 years
(range 49-68). The mean lesion size was 16 mm (range 7-24). All five lesions
showed features of a complex sclerosing lesion/radial scar in the form of central
sclerosis with elastosis and radiating benign entrapped tubules. One had
associated benign papillary structures and two had focal benign squamous
metaplasia. Four cases showed coexisting but distinct areas of low-grade
adenosquamous carcinoma with glandular and squamous epithelial differentiation in
a spindle cell background. One case had associated undifferentiated spindle cell
carcinoma. Detailed immunophenotypic characteristics of two cases are presented.
CONCLUSIONS: This series illustrates a postulated but previously unconfirmed
association between an unusual form of metaplastic breast carcinoma
(adenosquamous carcinoma) and complex sclerosing lesions. The mechanisms of
induction of breast carcinoma are poorly understood but these observations
further emphasize the potential for sclerosing lesion of the breast to be
associated with, and possibly give rise to, invasive carcinoma of different
types. The precise nature of the interaction between the pathological processes
remains unclear.
PMID- 10692022
TI - Leiomyosarcomas of the oral cavity: an unusual topographic subset easily mistaken
for nonmesenchymal tumours.
AB - AIMS: Oral leiomyosarcoma is rare and poorly documented. We aimed to characterize
these lesions clinicopathologically in order to facilitate their distinction from
other spindle cell neoplasms in the oral cavity. METHODS AND RESULTS: Ten cases
of oral leiomyosarcoma were retrieved and studied histologically and
immunohistochemically. Clinical data were obtained from referring pathologists
and prior literature concerning 46 comparable cases was reviewed. Nine out of 10
cases occurred in adults; 50% arose in the jaws and four showed bone involvement.
Histological appearances were similar to leiomyosarcomas elsewhere. In addition
to myogenic markers, two cases were also keratin-positive. Four patients
developed local recurrence or metastatic disease and three died of tumour (median
follow-up 37 months). CONCLUSIONS: Leiomyosarcoma is under-recognized in the
mouth, often being mistaken for a spindle-celled epithelial neoplasm. Aside from
an unusual but infrequent tendency to spread to lymph nodes and a location
specific differential diagnosis, its clinicopathological features are comparable
to leiomyosarcomas at other locations.
PMID- 10692023
TI - Paratesticular liposarcoma with smooth muscle differentiation mimicking
angiomyolipoma.
AB - AIMS: To discuss the differential diagnosis of a case of well-differentiated
liposarcoma which had areas resembling angiomyolipoma-a feature which, to our
knowledge, has not been reported previously. METHODS AND RESULTS: A tumour in the
paratesticular region had apparently been present for 40 years, but had grown
recently. A fat component containing lipoblasts was admixed with areas resembling
angiomyolipoma, i.e. desmin positive, but HMB45-negative smooth muscle
proliferation with atypia and thick-walled blood vessels devoid of elastin.
CONCLUSION: The diagnosis of liposarcoma, rather than angiomyolipoma with adipose
atypia, in this case is based on the fact that smooth muscle differentiation is
documented in liposarcoma, lack of HMB45 staining and recent clonality studies
which suggest that the fat in angiomyolipoma is not neoplastic.
PMID- 10692024
TI - Multinucleated stromal cells of the anal mucosa: a common finding.
AB - AIMS: To document the presence, morphology, immunophenotype and ultrastructure of
multinucleated stromal cells within the anal mucosa and to discuss possible
pathogenetic mechanisms for this occurrence. METHODS AND RESULTS: Multiple
sections of normal anal mucosa from 30 abdominoperineal resection specimens were
analysed by light microscopic, electron microscopic and immunohistochemical
methods. Multinucleated stromal cells were found in 22 cases (73%). They
contained two to five nuclei, arranged in a linear fashion or in a rosette or
grape-like pattern. They stained positive for vimentin and negative for actin,
desmin and oestrogen/progesterone receptors. Ultrastructural examination
confirmed their fibroblastic lineage. Mast cells were frequently observed in the
immediate vicinity of mono- and multinucleated cells. CONCLUSIONS: Multinucleated
stromal cells are a common occurrence in the normal anal mucosa. They should not
be misinterpreted as neoplastic cells. Mast cells may play a role in their
morphogenesis.
PMID- 10692025
TI - CD101 expression by Langerhans cell histiocytosis cells.
AB - AIMS: Our objective was to study the expression of a recently identified cell
surface molecule, CD101 and in Langerhans cell histiocytosis (LCH) patients as
CD101 has been shown to be present on dendritic cells. We wanted to determine if
CD101 expression could be helpful for the diagnosis of LCH in conjunction with
other markers (CD1a, S100 protein), and could be predictive of the evolution and
dissemination of the disease. METHODS AND RESULTS: The expression of CD101 was
studied by immunohistochemical technique in 11 cases of Langerhans cell
histiocytosis on frozen sections. The expression of CD101 was positive in nine
cases, high in six cases and low in three cases. There was no expression in the
other two cases. No correlation with the evolution, the localization or the
dissemination of the disease could be evidenced. CONCLUSIONS: CD101 is a new
phenotypic marker that might be useful in combination with other markers for the
diagnosis of LCH. However, as the anti-CD101 antibody works only in frozen
sections, its value is limited compared to anti-CD1a antibody.
PMID- 10692026
TI - Variation in the histological pattern of nodal involvement by gamma/delta T-cell
lymphoma.
AB - AIMS: Gamma-delta (gammadelta) T-cell non-Hodgkin's lymphomas (NHLs) usually
present with liver, spleen and marrow infiltration. Lymph node involvement by
gammadelta T-cell NHL has been rarely documented so far; its histological pattern
needs to be further defined. METHODS AND RESULTS: Two cases of nodal gammadelta T
cell NHL are reported: case 1, a 44-year-old man, presented with cytomegalovirus
retinitis and superficial lymphadenopathies. Histological analysis of an inguinal
lymph node showed complete destruction by a diffuse pleomorphic lymphoid
proliferation, which was positive for CD2, CD3, CD43, CD45, TIA-1 and granzyme B,
and displayed a gammadelta phenotype (deltaTCR1+, Vdelta1+, Vdelta2-, Vdelta3-,
betaF1-). Bone marrow was normal. Case 2, a male 24-year-old patient with a
history of renal transplantation, presented with hepatosplenomegaly and
supraclavicular lymph node enlargement. Lymph node architecture was globally
preserved. Peripheral sinuses contained scattered nests of medium-sized irregular
lymphoid cells. Bone-marrow was infiltrated. Phenotype showed positivity for CD2,
CD3, CD45 and TIA1 and expression of gammadelta TCR (deltaTCR1+, deltaV1+,
deltaV2-, deltaV3-, betaF1-). Both patients died a short time after diagnosis.
CONCLUSIONS: These observations suggest that at least two forms of nodal
gammadelta T-cell NHL may be encountered: one mimicking classical alphabeta T
cell NHL, with diffuse pleomorphic cell proliferation, and one displaying
sinusoidal neoplastic infiltration suggesting a close relationship with
hepatosplenic gammadelta T-cell NHL.
PMID- 10692027
TI - Giant lamellar bodies as a feature of pulmonary low-grade MALT lymphomas.
AB - AIMS: Giant lamellar bodies (GLBs) are rare pulmonary inclusions, most frequently
described in sclerosing haemangiomas. Following a recent report of their presence
in a case of pulmonary lymphoma of MALT origin, our aims were to determine their
frequency in pulmonary lymphoproliferative disorders, examine their structure and
investigate their aetiology further. METHODS AND RESULTS: We reviewed a series of
29 pulmonary lymphomas (23 low-grade, six high-grade) and 18 cases of reactive
pulmonary lymphoid hyperplasia. Five of 23 (22%) low-grade lymphomas contained
GLBs, 4/4 of which stained for surfactant apoprotein A but not for surfactant
apoprotein B. No GLBs were seen in 18 cases of reactive pulmonary lymphoid
hyperplasia or six high-grade primary pulmonary lymphomas. Ultrastructural
examination revealed concentrically arranged extracellular material forming
roughly spherical structures up to 25 microm in diameter. The GLBs were often
surrounded by foamy cells and cholesterol clefts, supporting an origin, at least
in part, from products of cell breakdown and surfactant degradation. CONCLUSION:
These findings support the idea that the presence of lamellar bodies is in part
due to stasis of products arising from degradation of surfactant, in association
with certain types of chronic pulmonary pathology. Given their absence in
reactive pulmonary lymphoid hyperplasia, the presence of GLBs as an epiphenomenon
in a pulmonary lymphoid infiltrate should warrant careful investigation with
regard to the diagnosis of low-grade MALT lymphoma.
PMID- 10692028
TI - Reduced expression of the cell-cycle inhibitor p27Kip1 is associated with
progression and lymph node metastasis of gastric carcinoma.
AB - AIMS: p27Kip1 (p27), a cyclin-dependent kinase inhibitor, plays an important role
as inhibiting the progression of the cell cycle. Decreased expression of p27 is
associated with high histological grade and aggressiveness of several human
tumours. We aimed to evaluate the role of p27 in the progression and metastasis
of gastric carcinoma. METHODS AND RESULTS: We analysed the expression of p27 in
67 primary gastric carcinomas and 31 lymph node metastases by
immunohistochemistry. Reduced expression of p27 was found more frequently in
advanced gastric cancer (40.9%) than in early gastric cancer (15.6%) (P < 0.001).
Decreased p27 expression correlated with large tumour size, high histological
grade, lymphatic invasion, advanced stage, deep invasion, lymph node metastasis
and recurrence. The expression of p27 showed an inverse correlation with the Ki67
labelling index. There was a significant reduction of p27 expression in
metastatic tumour cells in lymph nodes (mean positive cells: 3. 7%) when compared
to the corresponding primary gastric carcinomas (mean positive cells: 8.1%) (P =
0.008). CONCLUSIONS: Alterations of p27 expression may play an important role in
the progression and metastasis to lymph node of tumour cells in human gastric
carcinoma.
PMID- 10692029
TI - Epstein-Barr virus and gastric carcinoma in Western patients: comparison of
pathological parameters and p53 expression in EBV-positive and negative tumours.
AB - AIMS: The presence of Epstein-Barr virus (EBV) was studied in 56 gastric
carcinomas from Western patients by in-situ hybridization for EBV-encoded RNAs
(EBER). EBV-positive and negative carcinomas were compared for various
pathological parameters including p53 overexpression. METHODS AND RESULTS: EBERs
transcripts were detected in seven cases overall: four cases of 52 conventional
carcinomas (7. 7%) and three cases of four gastric carcinomas with lymphoid
stroma (75%). EBER positivity was diffuse in five cases and restricted to a
localized area of the tumour in two cases of conventional carcinoma. A monoclonal
EBV genomic pattern was demonstrated in the case tested by Southern blot
analysis. By immunohistochemical analysis, neither EBV latent or lytic cycle
proteins nor C3d/EBV receptor were expressed by neoplastic cells. EBER positivity
was significantly correlated with prominent lymphoid reaction (P = 0.0002) which
was associated with numerous PS100-positive dendritic cells and with HLA-DR
expression by tumour cells (P = 0.03). p53 immunoreactivity in more than 30% of
tumour cells was detected in 25 out 49 EBV-negative cases and was absent in EBV
positive cases except in one case with focal EBER-positivity. CONCLUSIONS: Focal
staining for EBER is an unusual finding in the setting of gastric carcinoma and
these results suggest that there might be two types of EBV-associated gastric
carcinoma in which the viral infection will play a different role. The presence
of a stromal lymphoid reaction which is strongly correlated with EBV positivity,
is associated with antigen-presenting ability by HLA-DR-positive tumour cells or
abundant dendritic cells. The function of p53 appears preserved in all EBV
associated carcinomas except in one case with focal EBER expression whereas the
immunohistochemical pattern of p53 is suggestive of a mutational phenomenon in
51% of EBV-negative cases.
PMID- 10692030
TI - Delayed appearance of decorin in healing burn scars.
AB - AIMS: We have previously shown that hypertrophic scar tissue from burn patients
contains abnormally high amounts of the proteoglycans versican and biglycan and
reduced amounts of decorin, in comparison with normal dermis or mature scar. The
lack of decorin may account for the poor organization of collagen fibrils in the
nodular areas of these scars. Decorin has also been reported to neutralize the
fibrogenic growth factor TGF-beta1. This study was conducted to monitor the time
course of expression of decorin in healing burn wounds by in-situ hybridization
to determine whether its absence from hypertrophic scars could result from
reduced synthesis. METHODS AND RESULTS: Scar tissue from 19 patients and normal
dermis from six patients, was fixed in paraformaldehyde, embedded in paraffin and
sectioned. Digoxigenin-labelled cRNA probes were prepared from a plasmid
containing a 622-bp insert of human decorin cDNA and used for in-situ
hybridization. Total numbers of connective tissue cells and cells positive for
decorin mRNA were counted in 10 random fields in the upper (papillary), middle
and lower (reticular) one-thirds of the dermis. In all regions the number and
percentages of cells with decorin mRNA were low during the first 12 months after
injury (eight samples), much higher between 12 and 36 months (seven samples) and
low and similar to those in normal skin after 36 months (five samples). The
differences between intermediate and early or late stage samples were
statistically significant (one-way ANOVA). Immunohistochemistry showed little
staining for decorin in early stage samples and much stronger staining in mid
stage. Late stage tissue showed intense staining for decorin, almost comparable
to that in normal dermis. CONCLUSION: Expression of decorin in burn wounds is
suppressed for about 12 months and then increases at a time when resolution of
hypertrophic scarring is generally considered to occur.
PMID- 10692031
TI - Specific markers for pulmonary tumours.
PMID- 10692032
TI - Antiviral protection after DNA vaccination is short lived and not enhanced by CpG
DNA.
AB - In this study, we investigated the potential of a DNA vaccine expressing the
minimal cytotoxic T lymphocyte (CTL) epitope gp33 of the lymphocytic
choriomeningitis virus glycoprotein to protect against infection of a non
lymphoid organ and compared this to protection against a systemic infection.
Furthermore, since immune stimulatory sequences have been shown to augment CTL
responses, we examined the capacity of CpG DNA to enhance CTL memory. The data
show that DNA vaccination with a gp33-based gene construct induced short-lived
gp33-specific CTL which protected against a systemic infection but not against a
peripheral infection. Immune stimulatory sequences were incapable of either
prolonging CTL memory or promoting protection against infection of a peripheral
organ.
PMID- 10692033
TI - CpG-oligodeoxynucleotides enhance T-cell receptor-triggered interferon-gamma
production and up-regulation of CD69 via induction of antigen-presenting cell
derived interferon type I and interleukin-12.
AB - Bacterial cytidine-phosphate-guanosine (CpG-DNA) activates antigen-presenting
cells (APC) and drives T helper 1 (Th1)-polarized immune responses in the mouse.
Claims have been made that CpG-DNA costimulates murine T cells. We examined the
direct and indirect effects of CpG-oligodeoxynucleotides (CpG-ODN) on human T
cell activation. CpG-ODN failed to costimulate purified human T cells activated
with alpha-CD3 or alpha-T-cell receptor (TCR)alphabeta antibodies. In contrast,
CpG-ODN sequence-specifically caused increased expression of CD69 on CD4 and CD8
T cells when peripheral blood mononuclear cells (PBMC) were stimulated via alpha
CD3. CpG-ODN and alpha-CD3 stimulation synergized to induce interferon-gamma (IFN
gamma) in T cells and natural killer (NK) cells, as shown by intracellular
fluorescence-activated cell sorter (FACS) staining. These effects of CpG-ODN on
human T cells were caused by the release of IFN type I (IFN-I) and interleukin-12
(IL-12) from PBMC. Enhancement of CD69 expression on alpha-CD3-triggered T cells
could be reproduced in a coculture transwell system of purified T cells and PBMC,
was inhibited by neutralizing antibodies to IFN-I and could be mimicked by adding
exogenous IFN-I. Furthermore, neutralization of either IFN-I or IL-12 diminished,
and in combination abolished, IFN-gamma production. These findings show that CpG
ODN potentiate TCR-triggered activation of human T cells in an APC-dependent
manner.
PMID- 10692034
TI - Inhibition of immunoglobulin E response to Japanese cedar pollen allergen (Cry j
1) in mice by DNA immunization: different outcomes dependent on the plasmid DNA
inoculation method.
AB - To develop a new immunotherapy for Japanese cedar (Cryptomeria japonica; CJ)
pollinosis, we evaluated the use of DNA immunization by inoculating mice with
plasmid DNA encoding Cry j 1 as a CJ pollen major allergen (pCACJ1). Repeated
intramuscular (i.m.) inoculation of BALB/c mice with pCACJ1 produced anti-Cry j 1
antibody responses, which were predominately of the immunoglobulin G2a (IgG2a)
type. Furthermore, this inoculation suppressed immunoglobulin E (IgE) and IgG1
antibody responses to subsequent alum-precipitated Cry j 1 injections. Splenic T
cells isolated from mice inoculated with pCACJ1 i.m. secreted interferon-gamma
(IFN-gamma), but not interleukin (IL)-4, in vitro upon stimulation with Cry j 1
as well as with p277-288, a peptide corresponding to the T-cell epitope of Cry j
1. In contrast, inoculation of BALB/c mice with pCACJ1 by gene gun injection
caused response predominantly of the IgG1 type, and enhanced production of anti
Cry j 1 IgE antibodies to subsequent alum-precipitated Cry j 1 injections.
Splenic T cells isolated from pCACJ1-innoculated mice by gene gun injection
secreted both IFN-gamma and IL-4 in vitro, upon stimulation with Cry j 1 as well
as with p277-288. These findings suggest that i.m. inoculation with pCACJ1
effectively elicits Cry j 1-specific T helper 1 (Th1)-type immune responses,
resulting in inhibition of the IgE response to Cry j 1.
PMID- 10692035
TI - Vgamma1+ gammadelta T cells play protective roles at an early phase of murine
cytomegalovirus infection through production of interferon-gamma.
AB - Cytomegalovirus (CMV) causes severe opportunistic infection in immunocompromised
hosts. The importance of conventional alphabeta T cells in protection against CMV
infection has been well documented. However, the role of the second T-cell
population (which express the gammadelta T-cell receptor) in CMV infection is not
known. In the present study, we analysed the function and protective role of
gammadelta T cells in a murine cytomegalovirus (MCMV) infection model. After
intraperitoneal infection with MCMV, the number of gammadelta T cells increased
in the liver and peritoneal cavity from day 3, and reached a peak on day 5. The
gammadelta T cells showed an activated T-cell phenotype and predominantly
expressed Vgamma1, which is known to be expressed by heat-shock protein 65 (hsp
65)-specific gammadelta T cells. Analysis of cytokine expression demonstrated
that the MCMV-induced gammadelta T cells expressed interferon-gamma (IFN-gamma)
and tumour necrosis factor-alpha (TNF-alpha) but not interleukin-4 (IL-4),
implying their participation in the cell-mediated immune response against MCMV.
Depletion of gammadelta T cells by anti-T-cell receptor (TCR) gammadelta
monoclonal antibody (mAb) treatment resulted in significant increase of virus
titre and decrease of IFN-gamma in the liver on day 3 after MCMV infection, which
further supports the importance of gammadelta T cells in early protection against
infection. Finally, the MCMV-induced gammadelta T cells produced IFN-gamma in
vitro in response to hsp 65. Our results suggest that gammadelta T cells
participate in early protection against MCMV infection through recognition of hsp
65 and production of IFN-gamma.
PMID- 10692036
TI - Bovine tuberculosis: immune responses in the peripheral blood and at the site of
active disease.
AB - This report describes a comparison of immune responses in the peripheral blood
and at the site of active disease in cattle 20 weeks after experimental infection
with Mycobacterium bovis. Lymphocyte proliferation, and the production of
interferon-gamma (IFN-gamma) and interleukin (IL)-2 were measured in response to
tuberculin and a number of mycobacterial antigens, including ESAT-6, MPB64,
MPB70, MPB83, hsp 16.1, hsp 65, hsp 70 and the 38 000 MW lipoprotein antigen. The
level of transforming growth factor-beta (TGF-beta) was measured following
stimulation of cells with tuberculin. Our results suggest little difference in
the responses of peripheral blood and lymph node cells to most of the antigens
used. However, tuberculin purified protein derivative (PPD) and ESAT-6 elicited
stronger responses in the peripheral blood compared with lymph node cells.
Investigation of the responding T-cell subpopulations in the peripheral blood
showed that both CD4+ and, to a lesser extent, gammadelta T-cell receptor
positive (TCR+) T cells contributed to these responses. This is the first report
to compare peripheral and local immune responses in bovine tuberculosis. Unlike
cases of human tuberculosis where immune activity at the site of disease and
anergy in the peripheral blood have been reported, our results suggest that for
bovine tuberculosis immune responses occurring in the peripheral blood reflect
those at the site of disease.
PMID- 10692037
TI - Minor role played by type I tumour necrosis factor receptor in the control of
Mycobacterium avium proliferation in infected mice.
AB - Control of mycobacterial growth depends on the concerted activity of different
cytokines acting in different stages of the development of innate and adaptive
immune responses. Tumour necrosis factor-alpha (TNF-alpha) has been shown to play
a protective role in Mycobacterium avium infections. Here we assessed the growth
of this mycobacterial species in wild-type mice and in mice with a genetically
engineered disruption of the type I receptor for TNF-alpha (p55-KO mice). p55-KO
mice infected with a low-virulence strain of M. avium exhibited a slightly
delayed capacity to eliminate the micro-organisms from the liver as compared with
wild-type animals. However, either the growth of this strain in the other organs
studied (spleen and lung) or the growth of two other strains of M. avium with
intermediate or high virulence, failed to be affected by mutation of the TNF
alpha receptor. p55-KO mice were also as protected by the administration of
recombinant interleukin-12 as the heterozygous p55 +/- mice. We conclude that
signalling through the type I TNF receptor plays a small role in vivo in the
induction of mycobacteriostasis during M. avium infection but may improve
survival during infection with virulent mycobacteria, independently of the extent
of their proliferation.
PMID- 10692038
TI - Relationship between disease severity and responses by blood mononuclear cells
from patients with rheumatoid arthritis to human heat-shock protein 60.
AB - The hypothesis that T-cell responses to the 60 000 MW family of heat-shock
proteins (hsp) may be related to the severity of rheumatoid arthritis (RA) was
examined. Peripheral blood mononuclear cells (PBMC) from most normal individuals
and both early and established RA patients proliferated in vitro in response to
human hsp 60 and mycobacterial hsp 65 as well as tetanus toxoid (TT) and
mycobacterial purified protein derivative (PPD). PBMC from some patients with
established RA gave responses to hsp 60 that were above the normal range and/or
peaked earlier than PBMC from normal individuals. The responses of PBMC from
established RA to hsp 65, but not PPD or TT, were also higher than those from
normal individuals, but the peak responses to all three antigens appeared
delayed. Thus a selective increase in responsiveness to hsp 60 develops with
disease duration in many RA patients. Six assessments of disease activity and
severity were made but apart from rheumatoid factor titre, they were unrelated to
the proliferative response. Similarly, disease activity and severity did not
differ between those RA patients whose hsp 60 stimulated cells produced
interferon-gamma and those who did not, although patients whose hsp 60-stimulated
T cells produced interleukin-4 (IL-4) and/or IL-10, appeared to have less disease
activity and severity than those who did not. Significant negative correlations
were found between IL-10 production by hsp 60-stimulated cells and disease
assessments. It is considered that RA is less severe in those patients whose hsp
60-stimulated cells produce T-helper 2 type cytokines.
PMID- 10692039
TI - Repeat bacterial challenge in a subcutaneous chamber model results in augmented
tumour necrosis factor-alpha and interferon-gamma response, and suppression of
interleukin-10.
AB - The present study compared the effect of a single or a repeat challenge with the
Gram-negative pathogen Porphyromonas gingivalis on the local inflammatory
response within subcutaneous chamber model in mice. Subcutaneous chambers were
implanted 2 weeks prior to the final challenge. The repeat-challenge (REP) group
received two intrachamber bacterial injections 14 days apart, while the single
injection group (SIN) received only a single bacterial challenge. Injection of
saline was used as the control. The cellular contents of the chamber exudates
were used for differential cell counts, and the supernatants were analysed for
tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), and
interleukin (IL)-10 levels. Immunoglobulin G1 (IgG1) and IgG2a levels to P.
gingivalis in the exudates were also determined. The results showed that the
leucocyte counts increased significantly post-challenge, and the REP group showed
the highest number of lymphocytes and neutrophils. Both P. gingivalis-challenged
groups exhibited significant increase in TNF-alpha and IL-10 levels at day 1 post
challenge. TNF-alpha levels in the chamber exudate were threefold higher in the
REP group compared with the SIN group on day 1 post-challenge (P < 0.05). In
contrast, IL-10 levels were significantly lower in the REP group 1 day post
challenge compared with the SIN group. The REP group had significantly higher
levels of IFN-gamma at baseline, and this difference remained significant 1 day
post-challenge. Analysis of antibody levels to P. gingivalis showed that while
the control and the SIN groups had no anti-P. gingivalis IgG in the chamber
exudate during the 7-day study period, the REP group showed high anti-P.
gingivalis IgG levels. In addition, the titres of IgG2a were fivefold higher than
the IgG1 titres. The results showed that a repeat local challenge with P.
gingivalis augmented the proinflammatory cytokines TNF-alpha and IFN-gamma, while
inhibiting the accumulation of the anti-inflammatory cytokine IL-10. This shift
towards a T helper 1 (Th1)-dominant response was reflected in the relatively high
anti-P. gingivalis IgG2a titres in the local inflammatory environment 7 days post
challenge.
PMID- 10692040
TI - Recessive expression of the H2A-controlled immune response phenotype depends
critically on antigen dose.
AB - Major histocompatibility complex (MHC) alleles acting as immune response genes
are coexpressed in heterozygous individuals and therefore control of immune
responses is usually codominant. As an exception to this rule, however, several
examples of recessive immune responses have been ascribed to regulatory, e.g.
suppressive, interactions. We report here that the recessive phenotype of both
antibody and T-cell responses to the mycobacterial 16 000-MW antigen depends
critically on a low antigen dose for immunization. On the basis of similar
responses in hemi- and heterozygous mice, we suggest that the mechanism of
recessive MHC control does not involve regulation by the low-responder allele. We
also demonstrated mixed haplotype restriction of peptide recognition for a
significant fraction of high-antigen-dose primed T cells. Their paucity under
limiting antigen dose conditions may lead to the recessive expression of MHC
control. In conclusion, our results suggest that recessive MHC control can be
explained as a simple gene dosage effect under conditions where antigen is
limiting, without a need for regulatory mechanisms.
PMID- 10692041
TI - Human invariant valpha24+ natural killer T cells activated by alpha
galactosylceramide (KRN7000) have cytotoxic anti-tumour activity through
mechanisms distinct from T cells and natural killer cells.
AB - Human Valpha24 + NKT cells, a subpopulation of natural killer cell receptor (NKR
P1A) expressing T cells with an invariant T-cell receptor (TCR; Valpha24JalphaQ)
are stimulated by the glycolipid, alpha-galactosylceramide (KRN7000), in a CD1d
dependent, TCR-mediated fashion. Little is known about Valpha24 + NKT-cell
function. The murine counterpart, Valpha14 + NKT cells, appear to have an
important role in controlling malignancy. There are no human data examining the
role of Valpha24 + NKT cells in controlling human malignancy. We report that
Valpha24 + NKT cells have perforin-mediated cytotoxicity against haemopoietic
malignancies. Valpha24 TCR, CD1d and alpha-galactosylceramide may all play a role
in cytotoxicity but are not absolute requirements. The greatest cytotoxicity was
observed against the U937 tumour cell line (95 +/- 5% lysis). THP-1, Molt4, C1R
cells and allogeneic mismatched dendritic cells were also sensitive to Valpha24 +
NKT cytotoxicity but neither the NK target, K562, nor lymphokine-activated killer
sensitive Daudi cells, were sensitive. These results indicate a killing pattern
distinct from conventional major histocompatibility complex-restricted T cells,
NK cells and other cytotoxic lymphoid cells previously described. We conclude
that human Valpha24 + NKT cells have cytotoxic anti-tumour activity against
haemopoietic malignancies through effector mechanisms distinct from conventional
T cells and NK cells and that their specific stimulator KRN7000 may have
therapeutic potential.
PMID- 10692042
TI - Increasing the frequency of T-cell precursors specific for a cryptic epitope of
hen-egg lysozyme converts it to an immunodominant epitope.
AB - Efforts to understand the mechanisms that govern how immunodominant T-cell
epitopes are selected from protein antigens have focused mostly on differences in
the efficiency of processing and presentation of peptide/major histocompatibility
complex (MHC) complexes by antigen-presenting cells, while little attention has
been directed at the role of the T-cell repertoire. In this report, the influence
of the T-cell repertoire on immunodominance was investigated using transgenic
mice that express the beta chain from a T-cell receptor specific for a cryptic Ek
restricted epitope of hen-egg lysozyme, HEL85-96. In these mice, the frequency of
HEL85-96-specific T-cell precursors is increased 10-20-fold over non-transgenic
mice. Transgenic mice respond as well as non-transgenic controls to intact HEL,
even though they respond poorly or not at all to a variety of other antigens,
including the dominant H-2k restricted epitopes of HEL. Following immunization
with native HEL, the only HEL peptide that could recall a response in vitro in
the transgenic mice was HEL85-96. Therefore, this normally cryptic epitope is the
sole immunodominant epitope in the transgenic mice, and this alteration in immune
response is due solely to an increase in the frequency of specific T-cell
precursors. An analysis of four additional H-2k restricted cryptic epitopes of
HEL suggests that three are similarly limited by T-cell frequency, and that only
one is consistent with a defect in efficient antigen presentation. This indicates
that there are at least two different types of cryptic epitopes, one in which
crypticity is caused by inefficient processing or presentation, and another in
which the frequency of specific T-cell progenitors is limiting.
PMID- 10692043
TI - In vivo rapid reduction of alloantigen-activated CD8+ mature cytotoxic T cells by
inhibitors of acidification of intracellular organelles, prodigiosin 25-C and
concanamycin B.
AB - Prodigiosin (PrG) 25-C and concanamycin B (CMB) are immunosuppressants that
specifically inhibit the induction of cytotoxic T cells (CTL) without affecting
the function of B cells and helper T cells in vivo. Both compounds inhibit
acidification of intracellular organelles and induce destruction of cytotoxic
granules and degradation of perforin in vitro. Here we show that a single
intraperitoneal (i.p.) injection of PrG 25-C, and of CMB, into mice eliminates
cytotoxic activity 7 days after alloantigen stimulation (when mature CTL activity
has been detected in control mice), with minimal effect on the alloantigen
specific antibody titre in serum. FK506 did not suppress the cytotoxic activity
with this administration schedule. Suppression was accompanied by a decrease in
the CD8+ population and in perforin expression of spleen cells induced by
alloantigen stimulation. The suppression of CTL activity and decrease in CD8+
cell number was detected as early as 7 hr after the injection of compounds. These
results suggest that inhibitors of acidification of intracellular organelles
suppress CTL activity in vivo by reducing the number of mature CD8+ CTL.
PMID- 10692044
TI - T-cell apoptosis and differential human leucocyte antigen class II expression in
human thymus.
AB - Relatively little is known of the details of human leucocyte antigen (HLA)
expression and thymocyte selection in human thymus. In both humans and mice major
histocompatibility complex (MHC) molecules have been described which show a
highly restricted thymic expression. Such patterns may offer clues about cellular
interactions in thymic selection because transgenic mice with MHC expression
targeted to specific thymic sites show altered T-cell receptor (TCR) repertoire
selection. We have analysed human thymic HLA class II expression, relating the
expression pattern to sites of thymocyte apoptosis. While HLA-DQ is poorly
expressed by most peripheral antigen-presenting cells (APC), thymus stains
strongly for HLA-DQ as well as for HLA-DR. HLA-DM is abundant in medulla but
weakly expressed by cortical cells. Class II expression in Hassall's corpuscles
(HC) is unusual in several respects: we have previously shown them to be
encircled by HLA-DO+ epithelial cells and here further demonstrate that HC are
negative for HLA-DR and HLA-DP, but often positive for HLA-DQ and HLA-DM.
Transcriptional control of HLA class II products at this site is thus unlike
cells that have previously been studied. Apoptotic thymocytes are restricted to
the cortex and the corticomedullary junction. However, a minority of apoptotic
cells are visible in the medulla, these being found in the HLA-DQ positive HC.
The apoptotic thymocytes in HC can be CD4+ single positive (SP), CD8+ SP or
CD4+CD8+ double-positive (DP). This study thus shows that the HC within human
thymic medulla are noteworthy both for their unusual hierarchy of HLA class II
expression and because they are the only medullary site of thymocyte apoptosis.
We propose that HC are a site at which mature thymocytes receive
activation/tolerization signals from peptides reprocessed from apoptotic cells.
The differential HLA transcriptional control at this site may indicate that
specific T-cell subpopulations are affected.
PMID- 10692045
TI - Characterization and role in experimental systemic lupus erythematosus of T-cell
lines specific to peptides based on complementarity-determining region-1 and
complementarity-determining region-3 of a pathogenic anti-DNA monoclonal
antibody.
AB - Peptides based on the complementarity-determining region 1 (CDR1) and CDR3 of an
anti-DNA monoclonal antibody (mAb) carrying the 16/6 idiotype (Id) were shown to
induce experimental systemic lupus erythematosus (SLE) in susceptible mouse
strains. In the present study, T-cell lines specific to the pCDR1 and pCDR3
peptides were established in BALB/c and in SJL mice, respectively. The T-cell
lines were characterized and analysed for their pathogenicity upon administration
to syngeneic mouse strains. Both T-cell lines expressed the alphabeta T-cell
receptor (TCR) and the CD4+ CD8- phenotype. Additionally, both cell lines
secreted interleukin (IL)-4 and IL-10 upon stimulation with their specific
peptide, thus belonged to the T helper 2 (Th2) subset. Upon immunization, the
pCDR3-specific T-cell line induced experimental SLE in SJL mice. The animals
produced high levels of autoimmune anti-DNA and antinuclear protein antibodies,
as well as anti-16/6 Id antibodies (Abs). Furthermore, the mice developed
clinical manifestations, including leukopenia, proteinuria and accumulation of
immune complex deposits in their kidneys. The pCDR1-specific T-cell line failed
to induce SLE when injected into BALB/c mice. It is thus suggested that pCDR3 is
an immunodominant epitope in experimental SLE and that pCDR3-specific T cells
initiate autoimmunity, leading to SLE, probably via epitope spreading.
PMID- 10692046
TI - Human B-cell lines constitutively express and secrete interleukin-16.
AB - Interleukin-16 (IL-16), produced by activated CD8+ T lymphocytes, is inhibitory
to human immunodeficiency virus-1 (HIV-1) replication. In an attempt to determine
whether human B cells express and secrete IL-16, a wide panel of B-cell lines
derived from patients with acquired immune deficiency syndrome (AIDS)-associated
B-cell lymphomas (AABCL) (n = 5) and from non-AABCLs (n = 8) were studied. Using
reverse transcription-polymerase chain reaction (RT-PCR) analysis, we were able
to observe ubiquitous expression of IL-16 mRNA. Kinetic studies on constitutive
mRNA turnover and secretion for IL-16 suggests that the optimum expression is at
24 hr. Interestingly, we report, for the first time, IL-16 secretion by human B
cell lines.
PMID- 10692047
TI - Activation of bovine B cells via surface immunoglobulin M cross-linking or CD40
ligation results in different B-cell phenotypes.
AB - Experiments reported herein demonstrate that activation of bovine B cells via
surface immunoglobulin M (sIgM) cross-linking, analogous to T-cell independent
(TI-2) antigenic stimulation, results in the expression of CD5. Interestingly, in
the presence of CD40 ligand, sIgM-mediated induction of CD5 on B cells was
inhibited. These findings indicate that activation of bovine B cells via B-cell
receptor (BCR) cross-linking results in a CD5+ B-cell phenotype and that CD40
signalling is inhibitory to this process. Analysis of cytokine mRNA indicates
that bovine B cells constitutively express tumour necrosis factor-alpha (TNF
alpha) and interleukin (IL)-1beta transcripts in vitro, while IL-10 mRNA
expression is induced following sIgM cross-linking. IL-12 p40 transcripts were
produced by B cells activated by CD40, but not by BCR, ligation. Analysis of
cytokine receptor mRNA indicates that activation through CD40, in the presence or
absence of IgM cross-linking, results in increased IL-4 receptor-alpha (IL
4Ralpha), IL-13Ralpha1 and interferon-alpha receptor 1 (IFN-alphaR1) mRNA levels.
Overall, these findings suggest that activation of bovine B cells through BCR
cross-linking yields an activation phenotype that differs substantially from that
of B cells activated through CD40.
PMID- 10692048
TI - CD40-CD40 ligand (CD154) engagement is required but may not be sufficient for
human T helper 1 cell induction of interleukin-2- or interleukin-15-driven,
contact-dependent, interleukin-1beta production by monocytes.
AB - To investigate whether antigen-independent, interleukin-2 (IL-2) or IL-15
activation of polarized T helper (Th) cells would result in contact-dependent
activation of monocytes, living Th1 and Th2 cell clones were co-cultured with THP
1 cells or fresh peripheral blood monocytes. Under these conditions IL-1beta
production was induced almost exclusively by Th1 cells and was dependent on the
presence and dose of IL-2 or IL-15, and on cell-cell contact, as demonstrated by
double-chamber cultures. Low levels of IL-1 receptor antagonist (IL-1Ra) were
induced by Th1 and higher levels by Th2 cells. IL-10 production was similar in
Th1/monocyte and Th2/monocyte co-cultures, thus arguing against preferential down
regulation of IL-1beta production by anti-inflammatory IL-10 in Th2 co-cultures.
In addition, IL-4 and IL-10 neutralization did not result in enhanced IL-1beta
production in Th2/monocyte co-cultures. Preferential expression on Th1 cells of
CD11b correlated with their capacity to induce IL-1beta production by THP-1 cells
in the presence of IL-2 or IL-15, but anti-CD11b monoclonal antibody could not
inhibit this activity. Blockade of the CD40-CD40 ligand interaction resulted in
inhibition of IL-1beta-inducing capacity while IL-1Ra induction was unaffected, a
result previously unknown. This differential effect indicates the selective
relevance of CD40-CD40 ligand engagement in inflammatory monocyte responses upon
activation by T cells. CD40 ligand expression levels did not differ in Th1 and
Th2 cell clones, thus indicating that additional, unidentified molecule(s)
preferentially expressed by Th1 cells are involved in their IL-1beta induction
capacity.
PMID- 10692049
TI - Inhibition of contact sensitivity in human CD4+ transgenic mice by human CD4
specific monoclonal antibodies: CD4+ T-cell depletion is not required.
AB - Clenoliximab and keliximab are monkey/human chimeric monoclonal antibodies (mAbs)
of the immunoglobulin G4 (IgG4) and IgG1 isotypes, respectively, that recognize
the same epitope on human CD4. The two mAbs possess identical idiotypes and
exhibit equal affinities for CD4. Upon administration of these mAbs to mice that
express a human CD4 transgene, but not mouse CD4 (HuCD4/Tg mice), clenoliximab
and keliximab exhibited similar kinetics of binding to CD4, and induced the same
degree of CD4 modulation from the cell surface, although only keliximab mediated
CD4+ T-cell depletion. Epicutaneous sensitization and challenge of HuCD4/Tg mice
with the hapten oxazolone resulted in a contact sensitivity response
characterized by tissue swelling, and the presence of interferon-gamma (IFN
gamma) and interleukin-4 (IL-4) in the local tissue. Administration of a single 2
mg dose of either clenoliximab or keliximab to HuCD4/Tg mice prior to
sensitization significantly reduced post-challenge tissue swelling, and levels of
IFN-gamma and IL-4, indicating that CD4+ T-cell depletion is not required for
anti-CD4 mAb-mediated inhibition of contact sensitivity. Administration of either
mAb prior to challenge failed to inhibit the contact sensitivity response,
indicating differential sensitivity of the afferent and efferent phases of the
response to inhibition by CD4-specific mAbs. Collectively, these data indicate
that CD4 functions as a positive regulatory molecule in the contact sensitivity
response.
PMID- 10692050
TI - Studies on delayed systemic effects of ultraviolet B radiation on the induction
of contact hypersensitivity, 3. Dendritic cells from secondary lymphoid organs
are deficient in interleukin-12 production and capacity to promote activation and
differentiation of T helper type 1 cells.
AB - Ultraviolet-B radiation (UVR) of mouse skin promotes both local and systemic
immune aberrations that are thought to be important in the pathogenesis of
cutaneous malignancies. Acute, low-dose UVR regimens inhibit the induction of
contact hypersensitivity (CH) in genetically susceptible mice by TNF-alpha
dependent mechanisms. In addition, these regimens also promote the development of
tolerance when hapten is applied to the UVR-exposed site at the completion of the
radiation treatment protocol. A third immune abnormality is also observed in mice
exposed to acute, low-dose UVR. This abnormality, which develops within 48-72 hr
of the completion of the UVR regimen, has been described among antigen-presenting
cells within secondary lymphoid organs, including lymph nodes that do not drain
the site of irradiation. Dendritic cells (DCs) from lymph nodes and spleens of
mice exposed to UVR lack the capacity to induce CH if they are derivatized with
hapten and injected intracutaneously into naive mice. The DC defect is related to
the production of and systemic dissemination of interleukin-10 (IL-10) by
keratinocytes within the epidermis of the UVR-exposed skin. We have now examined
the nature of the functional aberration that exists among DCs within the
secondary lymphoid organs of UVR-exposed mice by examining the capacity of DCs to
express co-stimulatory molecules, and their ability to activate ovalbumin (OVA)
specific DO11.10 T-cell receptor transgenic T cells in vitro. Our results
indicate that DCs from UVR-exposed mice produced insufficient amounts of IL-12.
When pulsed with OVA, these cells were capable of inducing proliferation among
DO11.10 T cells in vitro, but the responding cells produced neither IFN-gamma nor
IL-10 and IL-4. A similar antigen-presenting cell defect was generated in mice
treated with a subcutaneous injection of IL-10. We conclude that acute, low-dose
UVR creates an IL-10-dependent functional deficit in DCs in secondary lymphoid
organs, and that this defect robs UVR-exposed mice of the capacity to develop CH
when hapten is painted epicutaneously.
PMID- 10692051
TI - Modulation of CD11C+ splenic dendritic cell functions in murine visceral
leishmaniasis: correlation with parasite replication in the spleen.
AB - BALB/c mice resolve Leishmania donovani infection in the liver over an 8-12-week
period. However, after an initial phase of 2-4 weeks where increases in parasite
load are not readily detectable, parasite numbers in the spleen begin to increase
reaching maximum levels at 16 weeks post-infection. Thereafter, parasite
replication in the spleen is controlled and BALB/c mice maintain this residual
parasite load in the spleen for many months, without further increase. We
evaluated functions of CD11C+ splenic dendritic cells throughout the course of L.
donovani infection in the spleen of BALB/c mice. Unlike the dendritic cell (DC)
specific antigen DEC-205, CD11C was not up-regulated on macrophages during
visceral leishmaniasis. No appreciable impairment of splenic DC functions was
observed when this antigen-presenting cell subset was purified from 30-day post
infected mice. Significant impairment in inducing allogeneic mixed lymphocyte
reaction (MLR) and presenting L. donovani antigens or keyhole limpet haemocyanin
(KLH) to specific T cells was observed with CD11C+ splenic DC purified from 60
day post-infected mice. Functional impairment of splenic DC at 60 days post
infection correlated with their reduced surface expression of major
histocompatibility complex (MHC) class II molecules, impairment of interleukin-12
(IL-12) production and to their ability to suppress interferon-gamma (IFN-gamma)
production by Leishmania antigen-primed T cells. Of interest, the impairment of
splenic DC in presenting Leishmania antigens or KLH to specific T cells was
corrected at 120 days post-infection, and correlated with their up-regulation of
MHC class II expression, IL-12 production, induction of IFN-gamma by Leishmania
antigen-primed T cells and the onset of control over splenic parasite replication
in vivo. These results indicate that functional integrity of DC may be important
in controlling L. donovani infection.
PMID- 10692052
TI - Demonstration that platelet-activating factor is capable of activating mast cells
and inducing a chemotactic response.
AB - Platelet-activating factor (PAF) is generated in a variety of inflammatory
conditions in which mast cells accumulate. However, little is known about the
ability of PAF to influence mast cell function directly. In this study we examine
the ability of PAF to activate mast cells and regulate mast cell chemotaxis. PAF
was found to induce intracellular calcium mobilization and chemotactic responses
in both murine and human mast cells. PAF induced transient increases in
intracellular Ca2+ concentrations with a 50% effective dose of 1 nM and induced
significant migratory responses at PAF concentrations of 1 nM to 1 microM in the
human leukaemia mast cell line (HMC-1). Using signal transduction inhibitors,
both PAF-induced calcium mobilization and migration of mast cells were shown to
require activation of pertussis toxin-sensitive G proteins. PAF-induced calcium
and chemotactic responses were cross-desensitized by C5a. Together, these data
demonstrate that PAF is capable of activating distinct signalling pathways in
mast cells associated with calcium mobilization and cell migration; and that PAF
may thus contribute to the regulation of mast cell responses and hyperplasia at
sites of inflammation.
PMID- 10692053
TI - Soluble L-selectin levels in type I diabetes mellitus: a surrogate marker for
disease activity?
AB - L-selectin (CD62L) is a cell adhesion molecule which plays a key role in the
initiation of leucocyte migration from blood vessels to sites of local
inflammation. The aim of this study was to investigate T-lymphocyte expression of
CD62L antigen and serum levels of soluble L-selectin (sL-selectin) in subjects
with clinical and preclinical type I diabetes to determine whether they could
provide surrogate markers for disease activity. CD62L selectin expression on
memory T lymphocytes was studied by cytometric analysis in 22 patients with newly
diagnosed type I diabetes, 20 first-degree relatives of patients with type I
diabetes, 14 patients with Graves' disease, and 22 healthy controls. sL-selectin
levels were measured by enzyme-linked immunosorbent assay (ELISA) in enlarged
groups of subjects in these categories, as well as in patients with long-standing
type I diabetes, treated Graves' disease and type II (non-insulin dependent)
diabetes. L-selectin levels were also related to islet autoantibodies, human
leucocyte antigen (HLA) genotype and L-selectin T668C gene polymorphisms. L
selectin expression on memory T lymphocytes was reduced in newly diagnosed
diabetes and islet autoantibody positive siblings compared with controls. sL
selectin levels were significantly raised in newly diagnosed type I diabetes
compared with controls, with intermediate levels in family members, both with and
without islet autoantibodies, and in long-standing type I diabetes. Levels were
also raised in patients with untreated Graves' disease. Patients with type II
diabetes had sL-selectin levels which did not differ from controls. sL-selectin
levels correlated with the presence of diabetes-associated HLA alleles in both
family members and controls; levels also fell with increasing age in family
members. Multiple regression analysis showed that HLA genotype and age were
independent determinants of sL-selectin levels. sL-selectin levels are raised at
the time of diagnosis of type I diabetes and Graves' disease and appear to be
modulated by disease activity, but levels are determined predominantly by HLA
associated genetic susceptibility and age. sL-selectin may provide a late marker
of autoimmune destruction of islets and sequential measurement may be useful in
monitoring disease activity and the effect of interventions preceding type I
diabetes.
PMID- 10692055
TI - Review article: a therapeutic update on dermatomyositis/polymyositis.
PMID- 10692054
TI - Production and functional characterization of a soluble recombinant form of mouse
CD59.
AB - This report describes the engineering, expression, purification and functional
characterization of a soluble recombinant form of murine CD59 (srMoCD59). We
report the expression in Chinese hamster ovary (CHO) cells of a modified mouse
CD59 cDNA that had been truncated at D-74, resulting in the loss of the
glycosylphosphatidyl inositol (GPI) anchor, and containing six additional C
terminal histidines. The expressed srMoCD59 was purified from tissue culture
supernatant by means of its poly-histidine tag using immobilized metal affinity
chromatography. In comparison with CD59 on mouse erythrocytes, the srMoCD59 had a
reduced molecular weight (18-20 000 as compared with 20-28 000 for GPI-anchored
srMoCD59). The terminal complement inhibitory capacity of this soluble
recombinant protein was assessed using two methods: a cobra venom factor (CVF)
triggered 'reactive-lysis' system and a C5b-7 site assay. In both assays,
srMoCD59 inhibited lysis by the sera from all three species tested in the rank
order mouse > rat >> human. The amount of srMoCD59 required to produce 50%
inhibition of lysis in the C5b-7 site assay, using purified terminal components
to develop lysis, was 10-fold less than that required in the same assay when EDTA
serum was used as a source of C8 and C9, or in the CVF reactive lysis system.
These data indicate that the presence of serum markedly interfered with the
activity of srMoCD59 and have important implications for the use of recombinant
soluble CD59 analogues as therapeutic agents in complement-mediated diseases.
PMID- 10692056
TI - Review article: endocrinopathies and the skin.
PMID- 10692057
TI - Commentary: onychomycosis: an epidemio-etiologic perspective.
PMID- 10692058
TI - Epidemiology of pemphigus in Sofia, Bulgaria. A 16-year retrospective study (1980
1995).
AB - BACKGROUND: Pemphigus is a disease showing an uneven geographical distribution.
In Bulgaria pemphigus has always represented a substantial part of diagnosed
bullous diseases, but previous epidemiological data are incomplete. Our purpose
was to evaluate retrospectively the incidence and prevalence of pemphigus in the
district of Sofia (the capital of Bulgaria; population 1 200 000) for a sixteen
year period. METHODS: The files of all the newly registered patients with
pemphigus in the City Hospital of Dermatology in Sofia during the period Jan 1
1980 to Dec 31 1995, were collected and analysed with regard to personal
statistics, ethnic origin, profession, history of the disease including age and
season of onset, symptoms, clinical diagnosis, severity, laboratory findings,
associated illnesses, therapy, and cure rate. Special attention was paid to
smoking, alcohol abuse, and the presence of triggering factors such as emotional
stress, drug intake, underlying diseases, neoplasias, or others. RESULTS: During
the 16-year period studied, 74 newly diagnosed cases of pemphigus occurred in the
district of Sofia, giving a prevalence of 0.38 per 100 000 inhabitants and a mean
incidence of 0.47/100 000/year for the overall population and 0.51/100 000/year
for the population aged above 20 years. The most common clinical variant is
pemphigus vulgaris, frequently occurring in the fifth-sixth decades. The vast
majority of the patients are workers or professionals. CONCLUSIONS: The results
of the present retrospective study reveal a relatively high prevalence and
incidence of pemphigus in Bulgaria, compared to that encountered in other
countries. Our data is similar to that reported from Greece. Whether the Balkan
Peninsula represents a focus of population groups with high susceptibility to
pemphigus is a problem which could be highlighted by further epidemiological
studies in this geographic area.
PMID- 10692059
TI - Search for evidence of a Th2 profile in HIV+ patients.
AB - BACKGROUND: Hypersensitivity dermatoses are common in human immunodeficiency
virus-positive (HIV+) patients, particularly as the disease progresses. Studies
have shown that a switch to T-helper 2 (Th2) might represent a turning point in
HIV. This study investigated whether increases in the number of skin mast cells,
immunoglobulin E (IgE) serum levels, and eosinophilia, involved in the Th2
response in allergic disease, might also be present in HIV+ patients. If so,
these alterations might explain one of the mechanisms of skin hypersensitivity in
these patients. METHODS: Forty-five skin biopsies from the normal skin of the
upper arm of HIV+ patients and 15 controls were included in the study. HIV+
individuals were classified into three equal categories according to their
immunologic status: Category I (< 200/microL), Category II (200-499/microL), and
Category III (> 500/microL). Anti-tryptase antibody was employed in tissue
sections to show mast cells; IgE serum levels and eosinophils in peripheral blood
count were investigated; delayed-type hypersensitivity (DTH) skin tests
(candidin, trichophytin, and PPD 2U) were evaluated. RESULTS: Normal cutaneous
mast cell and eosinophil counts were the same in all categories and in the
control group, but increased IgE levels (P < 0. 01) and DTH skin test anergy (P <
0.006) were observed among acquired immunodeficiency syndrome (AIDS) patients.
CONCLUSIONS: The density of skin mast cells in HIV infection was not modified in
the course of the disease. Mast cells do not seem to be primarily responsible for
triggering hypersensitivity dermatoses among AIDS patients, although data in
support of the Th2 response, as seen in increased IgE serum levels and DTH
anergy, are present.
PMID- 10692060
TI - Cytodiagnosis of cutaneous basal and squamous cell carcinoma.
AB - OBJECTIVE: We performed a prospective study to evaluate the diagnostic accuracy
of cytologic examination in basal cell carcinomas (BCCs) and squamous cell
carcinomas (SCCs), in order to assess its clinical value. Study design Samples
were taken by the "scraping" technique which involves scraping with a scalpel
blade directly over the skin tumor surface, smearing the cells onto several glass
slides, and fixing them with "citospray." The specimens were stained with the
Papanicolaou stain. Punch biopsies were taken to confirm the clinical and
cytologic impression. RESULTS: We collected 45 skin tumors in total, clinically
presumed to be either BCC (n = 15) or SCC (n = 30). Imprint cytology demonstrated
to be of help in the rapid diagnosis of skin tumors. CONCLUSIONS: Cytologic
examination is easy to perform, saves time, provides a rapid diagnosis, and can
be considered, under experienced hands, reliable in the confirmation of malignant
skin tumors. Cytology does not give much information about tumor patterns or
subtypes which can be related to aggressive behavior and can be very important in
further therapeutic decisions. Therefore, histopathologic confirmation is
mandatory before any therapeutic maneuver.
PMID- 10692061
TI - Comparison of histopathologic and clinical evaluations of pathergy test in
Behcet's disease.
AB - BACKGROUND: The pathergy test, an important test in the diagnosis of Behcet's
disease, is currently applied with disposable/sharp needles and evaluated only
clinically (no histopathologic evaluation). In this study, the usefulness of the
pathergy test conducted intradermally and intravenously with disposable/sharp
needles in the diagnosis and determination of the activation of the disease is
studied in comparison with the test conducted with nondisposable/blunt needles.
In addition, histopathologic evaluation of the pathergy test is compared with the
clinical evaluation. METHODS: The study group consists of 43 Behcet's disease
patients together with 15 patients with dermatosis as the control group. The
pathergy test was applied to the Behcet's disease patients and the control group
intradermally and intravenously with disposable/sharp and nondisposable/blunt
needles. RESULTS: The results of the pathergy test on the patients and the
control group were evaluated clinically and histopathologically. CONCLUSIONS:
Clinical evaluation of the pathergy test conducted intradermally with
nondisposable/blunt needles is sufficient for both the diagnosis and
determination of the activation of Behcet's disease. Histopathologic evaluation
of the test is not found to be more sensitive than the clinical evaluation.
PMID- 10692062
TI - Lichenoid and granulomatous dermatitis.
AB - BACKGROUND: The prototypic lichenoid eruptions, lichen planus (LP), lichenoid
drug eruptions, secondary syphilis, and collagen vascular disease, are defined
histologically by a band-like lymphocytic infiltrate in close apposition to the
epidermis. We describe a novel form of lichenoid dermatitis with a granulomatous
component. DESIGN: Skin biopsies from 40 patients demonstrating a band-like
lymphocytic infiltrate with concomitant granulomatous inflammation were
encountered over 4 years. Clinicians were contacted to elucidate underlying
triggers and medical illnesses. RESULTS: A lichenoid dermatitis, a linear
eruption, vasculitis, annular erythema, and erythroderma were among the clinical
presentations. A drug-based etiology was implicated in 14 cases: the drugs
included antibiotics, lipid-lowering agents, anti-inflammatory drugs,
antihistamines, hydroxychloroquine sulfate, and angiotensin-converting enzyme
inhibitors. Over one-third of patients with drug-related eruptions had other
medical illnesses associated with cutaneous granulomatous inflammation, namely
rheumatoid arthritis (RA), Crohn's disease, hepatitis C, diabetes mellitus, and
thyroiditis. A microbial trigger was implicated in 12 patients in the context of
infective id reactions to herpes zoster, Epstein-Barr virus (EBV), or
streptococci, or active infections by Mycobacterium tuberculosis, M. leprae,
fungi, and spirochetes. The remainder had hepatobiliary disease and RA without
obvious exogenous triggers, cutaneous T-cell lymphoma (CTCL), and idiopathic
lichenoid eruptions (i.e. LP, lichen nitidus, and lichen striatus). One patient
with LP had underlying multicentric reticulohistiocytosis. The histiocytic
infiltrate assumed one or more of five light microscopic patterns: (i)
superficially disposed loose histiocytic aggregates; (ii) cohesive granulomata
within zones of band-like lymphocytic infiltration with or without deeper dermal
extension; (iii) a diffuse interstitial pattern; (iv) scattered singly disposed
giant cells; and (v) granulomatous vasculitis. Additional features included
lymphocytic eccrine hidradenitis in those patients with drug reactions,
hepatobiliary disease, and antecedent viral illnesses, tissue eosinophilia and
erythrocyte extravasation in drug hypersensitivity, granulomatous vasculitis in
patients with microbial triggers, drug hypersensitivity or RA, and lymphoid
atypia in lesions of CTCL or drug hypersensitivity. CONCLUSIONS: The cutaneous
lichenoid and granulomatous reaction may reflect hepatobiliary disease,
endocrinopathy, RA, Crohn's disease, infection, or a drug reaction. One-fifth of
cases represent idiopathic lichenoid disorders. Lymphoproliferative disease or
pseudolymphomatous drug reactions must be considered in those cases showing
lymphoid atypia.
PMID- 10692063
TI - Oral lichen planus: different clinical features in HCV-positive and HCV-negative
patients.
AB - BACKGROUND: Hepatitis C virus (HCV) infection induces variable dermatologic
manifestations. OBJECTIVE: To determine whether differences exist in the clinical
features and behavior of oral lichen planus (OLP) between HCV-positive (HCV+ve)
and HCV-negative (HCV-ve) patients. METHODS: Two hundred and sixty three patients
(156 women and 107 men), with a mean age of 55.5 years, with OLP (76 HCV+ve and
187 HCV-ve) were clinically evaluated. Previously, all local factors that could
modify the clinical characteristics were removed and were monitored carefully
following morphology. RESULTS: In both groups, the prevalent clinical form of OLP
was the mixed form (33.1% in HCV-ve and 35.5% in HCV+ve patients), in which
reticular-plaque lesions coexist with atrophic-erosive ones. The reticular form
was more frequent in HCV+ve (25%) than in HCV-ve (18. 7%) patients, whereas
plaque lesions were more prevalent in HCV-ve (15.5%) than in HCV+ve (5.2%)
patients (P < 0.01, chi-squared test). There were no significant differences in
the frequency of erosive (27.2% in HCV-ve and 27.6% in HCV+ve) and atrophic (5.3%
in HCV-ve and 5.2% in HCV+ve) forms between the two groups. CONCLUSIONS: Our
findings show that there were statistically significant differences between OLP
HCV-ve and OLP-HCV+ve groups for reticular and plaque clinical forms. These
findings underline the importance of liver examination in all OLP patients,
including cases with mild, asymptomatic keratotic forms of the disease.
PMID- 10692064
TI - Dermatomyositis presenting as panniculitis.
PMID- 10692065
TI - T-cell chronic lymphocytic leukemia mimicking dermatomyositis.
PMID- 10692066
TI - Sympathectomy-induced ichthyosis-like eruption.
PMID- 10692067
TI - Recessive dystrophic epidermolysis bullosa complicated with nephrotic syndrome
due to secondary amyloidosis.
PMID- 10692068
TI - An epidemic of porphyria cutanea tarda?
PMID- 10692069
TI - Pityriasis lichenoides-like exanthem and primary infection by Epstein-Barr virus.
PMID- 10692070
TI - Effects of environmental conditions on microbial proteolysis in a pork myofibril
model system.
AB - A number of bacterial strains used for meat fermentations were screened for
proteolytic activity. A strain of Micrococcus which was found to be proteolytic
was evaluated for the effects of environmental conditions on its proteolytic
activity against pork myofibrillar proteins using response surface methodology.
Three strains of micrococci were also tested for the ability to produce free
amino acids from pork myofibrils. Analysis of the effects of environmental
conditions showed that proteolytic activity would be minimal under conditions
normally found in fermented sausages, thereby suggesting that proteolysis in
these products is largely due to endogenous meat enzymes. The three strains of
micrococci were shown to produce free amino acids from pork myofibrils, thereby
demonstrating the presence of peptidase activity in these strains.
PMID- 10692071
TI - Influence of water activity and nutrients on growth and production of
squalestatin S1 by a Phoma sp.
AB - This study investigated the effects of temperature, nutrient status and water
activity (aW) on the production of squalestatin S1 by a Phoma sp. The fungus was
grown on malt extract (MEA), wheat extract (WEA), oat extract (OEA) and oil seed
rape extract (OSREA) agars at 15, 20 and 25 degrees C and 0.998, 0.995, 0.990,
0.980 and 0.960 aW levels. The growth rate and secondary metabolite formation
were followed over a total of 30 d. The maximum growth rate was observed at 25
degrees C and 0.998-0.990 aW for all media types, which was significantly reduced
(P = 0.05) for most media at 0.96 aw. The growth rate was greatest for WEA and
OEA but the growth form was an effuse exploitative type compared with the dense
assimilative type on the richer MEA. The lipid-based OSREA appeared to be a poor
growth substrate for this fungus. In contrast to the growth rate data,
squalestatin S1 production was maximal for all media types at slightly reduced aw
in the range 0.990-0.980. There was greater production of the secondary
metabolite under significant water stress (0.960 aW) compared with that with
freely available water (0.998 aW). Maximum production was observed in WEA.
Production began earlier in WEA and OEA compared with MEA. Squalestatin S1
production was not significantly affected by incubation temperature (P = 0.05).
This study has shown that nutritionally depleted substrates may be usefully
employed in the production of squalestatin S1 and perhaps also for other
secondary metabolites.
PMID- 10692072
TI - Diversity among lactococci isolated from ewes' raw milk and cheese.
AB - The technological and genetic characteristics of lactococci present in ewes' raw
milk and 1-d-old ewes' raw milk cheeses sampled over a 1-year period were
investigated. The proportion of lactic acid bacteria isolates from milk samples
able to decrease milk pH by more than 1.25 units after 6 h incubation at 30
degrees C reached 14.5% in spring vs 10.7% in summer, 8.3% in autumn and 3.0% in
winter. In 1-d-old cheese samples, the proportion of lactic acid bacteria able to
lower milk pH by more than 1.25 units increased up to 32.3% in spring vs 23.4% in
summer, 8.0% in autumn and 10.3% in winter. Fast acid-producing lactic acid
bacteria mainly belonged to the genus Lactococcus. Using polymerase chain
reaction protocols, fast acid-producing lactococci were grouped as 61 Lactococcus
lactis subsp. lactis, 13 L. lactis subsp. cremoris and 14 L. lactis subsp. lactis
biovar diacetylactis. Randomly amplified polymorphic DNA (RAPD) fingerprinting of
fast acid-producing lactococci, using two primers, resulted in 21 different RAPD
patterns for L. lactis subsp. lactis isolates, nine RAPD patterns for L. lactis
subsp. cremoris isolates and three RAPD patterns for L. lactis subsp. lactis
biovar diacetylactis isolates. Up to 19 different RAPD patterns were found for L.
lactis isolates from cheeses made in a particular month.
PMID- 10692073
TI - Response to NaCl of nitrate assimilation and nitrogenase activity of the
cyanobacterium Anabaena sp. PCC 7120 and its mutants.
AB - The presence of NaCl in the nutrient solution promoted nitrate uptake in parent
Anabaena sp. PCC 7120, mutants SP7 (defective in nitrate reductase activity) and
SP17 (partially defective in nitrate reductase activity), but not in the mutant
SP9 (defective in nitrate transport and reduction). Nitrate reductase activity of
the parent and mutant SP17 increased with increasing concentration of nitrate in
saline medium, while mutants SP7 and SP9 did not respond to the altered salinity.
Although Na+ was not required for nitrate reductase activity, its presence in the
nutrient solution enhanced nitrate reduction. Complete removal of Na+ from the
nutrient solution markedly reduced nitrogenase activity in all the strains, while
raising the concentration of NaCl to 50 mmol l-1 or above, was equally toxic to
nitrogenase activity. External NaCl at 200 mmol l-1 brought down the nitrogenase
activity to the same residual level as observed without Na+.
PMID- 10692074
TI - Evaluation of different PCR-based DNA fingerprinting techniques for assessing the
genetic variability of isolates of the fungus Epicoccum nigrum.
AB - Thirty-six strains of the fungus Epicoccum nigrum, isolated from different
substrata and ecosystems of Europe, America and Africa, were analysed using 14
molecular markers included in 5 different genetic fingerprinting techniques: AP
PCR, tDNA-PCR, microsatellite-primed PCR, ARDRA and AFLP. All of the techniques
used were able to differentiate the isolates, showing a high genetic diversity
within the species. However, the different techniques detected different levels
of similarity among the strains; ARDRA shows the most homogeneous results whilst
AP-PCR shows the most heterogeneous. The similarity indices achieved for each
strain were compared for the different techniques. The distribution obtained by
microsatellite-primed PCR was similar to those shown by AP-PCR techniques. tDNA
PCR and AFLP rendered similar distributions, and ARDRA showed remarkably
different results from the other techniques. The results also reveal the lack of
an overall correlation between geographical or ecological origin of the isolates
and their genotypes.
PMID- 10692075
TI - Studies on strong and weak killer phenotypes of wine yeasts: production, activity
of toxin in must, and its effect in mixed culture fermentation.
AB - Two different killer phenotypes were detected among K+ (killer) yeasts isolated
from spontaneous wine fermentations using a plate bioassay. The two phenotypes
differed in their degree of killer activity, and were designated as SK+(strong
killer) and WK+(weak killer). Strains showing either phenotype were assayed for
expression of killer activity under different growth conditions. Growth in must
negatively affected expression of the killer activity of both phenotypes. The
supernatant fluids from must cultures showed a lower killing effect than those
from yeast phosphate dextrose broth (YPDB) cultures. The ability of the two K+
phenotypes to prevail on K-sensitive yeasts was studied in mixed-culture
fermentation experiments. Under these conditions, only strains showing SK+
phenotype were able to prevail on the K-sensitive yeasts. These results suggest
that the K+ phenotype could play a relevant role in spontaneous fermentations
provided that the strain exhibits an SK+ phenotype, and that the latter phenotype
should be preferred when selected K + strains are to be used as fermentation
starters.
PMID- 10692076
TI - Cluster organization of the genes of Streptomyces pristinaespiralis involved in
pristinamycin biosynthesis and resistance elucidated by pulsed-field gel
electrophoresis.
AB - Streptomyces pristinaespiralis synthesizes pristinamycin, a member of the
streptogramin antibiotic family which consists of a mixture of two types of
chemically unrelated compounds named pristinamycins I and pristinamycins II. In
order to estimate the size of the Strep. pristinaespiralis chromosome and to
elucidate the organization of the pristinamycin biosynthetic and resistance genes
already identified, it was decided to use the pulsed-field gel electrophoresis
technique. Results indicate that the Strep. pristinaespiralis chromosome is
linear and about 7580 kb, as previously shown for several other Streptomyces
species. By hybridization, it could be shown that the biosynthetic and resistance
genes for pristinamycins I and pristinamycins II, except for the multidrug
resistance gene ptr, are interspersed and seem to be organized as a single large
cluster, covering less than 200 kb corresponding to 2.6% of the total size of the
chromosome. The consequences and significance of such a genetic organization are
discussed.
PMID- 10692077
TI - Rapid detection and quantification of yeast species during spontaneous wine
fermentation by PCR-RFLP analysis of the rDNA ITS region.
AB - PCR-RFLP analysis of the rDNA-ITS (internal transcribed spacer) region was
applied to 174 yeast strains belonging to 30 species of oenological significance
and including 27 type strains in order to define a rapid identification protocol
for yeast colonies. DraI-or HaeIII-PCR-RFLP patterns were species-specific with
the exception of teleomorphic and anamorphic forms. An improved protocol taking
about 30 h was used for the detection and quantification of yeast species
occurring in the course of a spontaneous wine fermentation at industrial level.
Wine samples were taken and plated daily on an agar medium and the developed
colonies were analysed by PCR-RFLP after 24 h of incubation. A representative
sample of these colonies was also identified by traditional methods. Both
procedures gave identical results. However, PCR-RFLP analysis allowed a more
precise enumeration of the yeast populations, proving to be a reliable and simple
method for monitoring the development of the yeast community throughout wine
fermentation.
PMID- 10692078
TI - 21st Century: Review: Ageing and medicine.
AB - Throughout the world, populations are ageing. The response of the health services
needs to be based on a knowledge of the nature of human ageing and the principles
of rational health care for older people. Ageing comes about from interactions
between intrinsic (genetic) and extrinsic (environment and lifestyle) factors.
Health care has to be responsive to the general needs of older people, but also
to recognize the heterogeneity produced by different rates and patterns of
individual ageing. There are now real possibilities of improving the course of
human ageing through modulation of both intrinsic and extrinsic processes. There
is also a need to adapt social institutions to what is a permanent change in
demography.
PMID- 10692079
TI - Molecular aspects of the inherited porphyrias.
AB - The porphyrias are diseases due to marked deficiencies of enzymes of the haem
biosynthetic pathway (Fig. 1). Except for the first enzyme of the pathway, delta
aminolevulinate synthase (ALAS), deficiencies in seven other enzymes are
associated with the various forms of porphyria (Fig. 2). Porphyrias can be
classified as either hepatic or erythroid, depending on the major site of
production of porphyrins or their precursors. The pathogenesis of all inherited
porphyrias has now been defined at the molecular level, and it is clear that
there is a great deal of genetic heterogeneity in each porphyria [1].
PMID- 10692080
TI - Cortisol axis abnormalities early after stroke--relationships to cytokines and
leptin.
AB - OBJECTIVE: To assess the relationships between circulating levels of
proinflammatory cytokines and adrenocortical hormones and leptin early after
stroke. DESIGN: Blood samples were collected four times daily the first two days
after stroke, twice daily the next 4 days and four times at day 7. Cognitive
function and functional outcome was measured at admittance and at day 7. SETTING:
Consecutive inclusion of patients admitted to the stroke unit at Umea University
Hospital. SUBJECTS: Eight men and 4 women with acute stroke and 10 healthy
volunteers. MAIN OUTCOME MEASURES: Levels and diurnal variations of plasma
proinflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor-alpha
(TNF-alpha), serum adrenocortical hormones (cortisol and DHEA) and leptin, and
MMSE, SSS, and ADL scores. RESULTS: A significant correlation was present between
IL-6 and cortisol levels the first two days after stroke (P < 0.05). In patients
with a disturbed diurnal rhythm of cortisol, cortisol and leptin levels were
increased (68% and 81% increase, respectively), whilst DHEA levels were
unaltered. Half of the patients displayed an abnormal diurnal rhythmicity of
leptin at the end of the week. Median TNF-alpha levels for the first two days
after stroke also correlated to median leptin levels at the end of the week (P <
0.05). Median IL-6 levels correlated to severity of paresis on days 1 and 7 and
to MMSE scores on day 7 (P < 0.05). CONCLUSIONS: Neuroendocrine disturbances are
common and often profound early after stroke. Cytokines seem to be important
modulators of these disturbances, including diurnal rhythmicity of cortisol and
leptin.
PMID- 10692081
TI - The hypothalamic-pituitary-adrenal axis activity as a predictor of cardiovascular
disease, type 2 diabetes and stroke.
AB - OBJECTIVES: The hypothalamic-pituitary-adrenal (HPA) axis, the mediator of
cortisol, plays a central role in the homeostatic processes. In this study, we
addressed the potential impact of HPA axis activity on established
anthropometric, metabolic and haemodynamic risk factors for cardiovascular
disease (CVD), type 2 diabetes mellitus and stroke. DESIGN: A cross-sectional
study. SUBJECTS: A subgroup of 284 men from a population sample of 1040 at the
age of 51 years. MAIN OUTCOME MEASURES: Anthropometric measurements included body
mass index (BMI, kg m-2), waist/hip circumference ratio (WHR) and abdominal
sagittal diameter (D). Overnight fasting values of blood glucose, serum insulin,
triglycerides, total, low (LDL) and high density (HDL) lipoprotein cholesterol,
as well as resting heart rate and blood pressure, were also determined. By using
repeated diurnal salivary cortisol measurements during everyday conditions,
methods were developed to characterize the status of the HPA axis, and set in
relation to the anthropometric, metabolic and haemodynamic measurements. RESULTS:
In bivariate analyses, risk factors intercorrelated in clusters of anthropometric
(BMI, WHR, D), metabolic (insulin, glucose and their ratio, triglycerides,
cholesterol [total and LDL], HDL cholesterol [negative]) and haemodynamic
(systolic and diastolic blood pressure and heart rate) measurements. This was
also the case in the two-dimensional scaling analysis, where, however, HDL
separated out. A normal HPA axis status, characterized by high variability and
morning cortisol values, as well as a clear response to a standardized lunch and
dexamethasone suppression test, was then introduced by a statistical weighting
procedure. This did not essentially change the results of either the bivariate
correlation matrix or the two-dimensional scaling analysis. A similar
introduction of a pathological HPA axis, characterized by low variability and
morning cortisol values, a poor lunch-induced cortisol response and a blunted
dexamethasone suppression of cortisol, changed the results markedly. Now strong
and consistent correlations were found not only within but also between different
clusters of risk factors, which also congregated into one distinct cluster, again
except for HDL cholesterol. CONCLUSIONS: These results disclose the prospect of
an overriding function of a pathological HPA axis on other, established risk
factors for CVD, type 2 diabetes and stroke. Its close association to HPA axis
dysfunction may explain the previously reported powerful risk indication of
abdominal obesity for the diseases mentioned. The HPA axis abnormality has been
reported to be a characteristic consequence of frequently repeated or chronic
environmental stress challenges.
PMID- 10692082
TI - Independent effects of obesity and cortisol in predicting cardiovascular risk
factors in men and women.
AB - OBJECTIVES: Recent data suggest that higher plasma cortisol may be associated
with hypertension and insulin resistance in otherwise healthy men, as it is in
Cushing's syndrome. However, obesity in women is associated with lower plasma
cortisol concentrations. This study sought to establish whether plasma cortisol
is associated with cardiovascular risk factors in women as it is in men, and
whether these relationships in either sex are confounded by obesity. DESIGN: A
population-based cross-sectional study. SETTING: The MONICA study in northern
Sweden. SUBJECTS: From a target cohort of 2500, 1921 subjects took part and 226
were randomly selected because they attended between 07.00 and 09.00 h after an
overnight fast. A 75 g oral glucose tolerance test was performed and blood
sampled at baseline and 2 h after glucose. RESULTS: Plasma cortisol was lower in
relatively obese subjects: in men, this was observed only in the 2 h sample (r =
0.23, P = 0.02) and in women only in the fasting sample (r = -0.26, P < 0.01).
Simple regression analysis did not identify relationships between plasma cortisol
and blood pressure, serum lipids, fasting insulin or glucose tolerance. However,
after adjusting for the effect of obesity by multiple regression, higher plasma
cortisol was independently associated with higher diastolic blood pressure in men
(r = 0.21, P = 0.04) but not in women, and higher fasting serum triglyceride
levels in women (r = 0.28, P < 0. 001) but not in men. CONCLUSIONS: Increasing
obesity and plasma cortisol concentrations make independent and sex-specific
contributions to variations in blood pressure and aspects of the insulin
resistance syndrome. Adverse cardiovascular risk is greatest in those with the
combination of obesity and failure to downregulate plasma cortisol levels.
PMID- 10692083
TI - Tissue-type plasminogen activator and C-reactive protein in acute coronary heart
disease. A nested case-control study.
AB - OBJECTIVES: To study the importance of inflammation and fibrinolysis for
evolution of ischaemic heart disease in a cohort of initially healthy subjects.
DESIGN: Nested case-control study. Follow-up periods 7-15 years. SUBJECTS:
Included in the study were 133 cases with coronary heart disease and 258
controls. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Subjects with ischaemic
heart disease identified in 1991 by the Danish National Hospital Register.
Protein concentration of C-reactive protein (CRP) and tissue-type plasminogen
activator (t-PA) were measured with ELISA methods in stored serum samples.
RESULTS: CRP and t-PA concentrations were both significantly higher in cases than
in controls (P < 0.001 and P < 0. 001). This difference between cases and
controls for CRP and t-PA was present in both men (CRP: P = 0.022; t-PA: P =
0.001) and women (CRP: P = 0.013; t-PA: P = 0.005) and it was present in both the
7-9 years follow-up cohort (CRP: P = 0.014; t-PA: P = 0.001) and the 15 years
follow-up cohort (CRP: P = 0.027; t-PA: P = 0.012). The best predictor of CRP was
t-PA, whilst the best predictor of t-PA was triglycerides. In a logistic
regression analysis model, t-PA still came out as independent predictor of
coronary heart disease, whilst such a significance disappeared for CRP. With the
use of ROC curves we determined that AUC for t-PA was 0.62, and for CRP 0.59,
indicating that none of these two analytes has a high prognostic power in
predicting future coronary events in an initially healthy population. CONCLUSION:
We conclude that moderate increases in serum concentrations of CRP and t-PA are
present for up to 15 years before the presence of clinical overt coronary heart
disease; that a low-grade inflammation is determined by other risk factors and
that t-PA is an independent risk factor for evolution of coronary heart disease.
PMID- 10692084
TI - Helicobacter pylori CagA seropositivity does not influence inflammatory
parameters, lipid concentrations and haemostatic factors in healthy individuals.
AB - BACKGROUND: H. pylori CagA seropositivity has been recently associated with
ischaemic heart disease. OBJECTIVE: To evaluate whether H. pylori virulence has
any effect on certain circulating coagulation factors and on markers of systemic
inflammation in healthy individuals. DESIGN: Prospective cohort study. SETTING:
Haematology and gastroenterology unit at a university teaching hospital.
SUBJECTS: A total of 494 consecutive asymptomatic blood donors attending a blood
bank. MEASUREMENTS: Blood analysis for haemostatic factors, lipids
concentrations, inflammatory parameters as well as determination of anti H.
pylori IgG and CagA reactivity by ELISA assayes. RESULTS: The overall prevalence
of H. pylori infection was 53%; 56% of H. pylori positive sera expressed CagA
reactivity. CagA seropositive subjects did not differ significantly from CagA
negative or H. pylori negative subjects in values for lipids, haemostatic
factors, or inflammatory parameters. CONCLUSIONS: CagA seropositivity is not
associated with increased systemic inflammation or with raised concentrations of
haemostatic factors - predictors of ischaemic heart disease - in healthy
individuals.
PMID- 10692085
TI - Coronary artery disease and arterial hypertension: clinical, angiographic and
follow-up data.
AB - OBJECTIVES: To evaluate how the presence of arterial hypertension affects
coronary atherosclerosis and prognosis in patients with, or at high risk of,
ischaemic heart disease. DESIGN: Retrospective analysis of clinical records and
follow-up data. SETTINGS: Single referral centre for ischaemic heart disease.
SUBJECTS: All consecutive patients (n = 1700, 38% with hypertension) undergoing
coronary angiography for the evaluation of ischaemic heart disease during 1983
92. RESULTS: On angiography, the likelihood of having three-vessel disease was
higher amongst hypertensives (odds ratio = 1.41; 95% confidence interval [CI] =
1.08-1.85) after adjustment for age, sex, and angina symptoms. The sum of all
visible stenoses (an index of overall atherosclerotic involvement) was 19% higher
in hypertensives (262 +/- 204 vs. 220 +/- 194 units, P < 0.005). By multivariate
analysis, the presence of hypertension made a modest (+ 28 units), albeit
statistically significant, independent contribution to the total atherosclerosis
score. On follow-up (median = 96 months), cardiovascular mortality was slightly
higher in the hypertensive patients than in the normotensive group (P < 0.05 in a
Kaplan-Meier analysis), but a proportional hazard analysis adjusting for age and
gender showed no significant independent contribution of hypertension.
Hypertensive patients, however, remained at higher risk of non-fatal myocardial
infarction following discharge (adjusted odds ratio = 1.21, 95% CI = 1.03-1.46; P
< 0.05). CONCLUSIONS: In this referral population, hypertension is a risk factor
for presence of three-vessel disease. Distribution, severity and extension of
coronary stenosis are similar to those of normotensive patients, and prognosis is
only marginally affected.
PMID- 10692086
TI - Heart rate and mortality.
AB - OBJECTIVES: Increased heart rate has shown to be associated with risk of
mortality from cardiovascular diseases in some studies, but not in others.
Increased heart rate has also been linked to causes of death other than
cardiovascular. To clarify the role of heart rate as a predictor of death we
studied its predictive value in a large population study. DESIGN: A prospective
population study with a follow-up time of 23 years. SUBJECTS AND METHODS: The
study population comprised 5598 men and 5119 women 30-59 years of age on entry.
Heart rate was measured from resting ECGs. MAIN OUTCOME MEASURE: Mortality from
specified causes. RESULTS: A total of 1848 men and 840 women died during the
follow-up period. Increased heart rate was significantly associated with death
from all causes, cardiovascular causes, and natural noncardiovascular,
nonmalignant causes of death. Increased heart rate was associated with death from
cancer in men with heart disease but not in men without heart disease on entry
into the study. The increase in cardiovascular mortality with high heart rate was
explained by the close association between heart rate and blood pressure.
Adjustment for risk factors did not alter the significance of the association
between increased heart rate and mortality from noncardiovascular causes.
CONCLUSIONS: High heart rate is simple to observe clinically and a significant if
nonspecific predictor of mortality. Increased risk of mortality from
cardiovascular diseases can be explained by association with high blood pressure.
The increased mortality risk associated with high heart rate related mainly to a
group of diseases of noncardiovascular or nonmalignant origin.
PMID- 10692087
TI - Psychosocial variables in relation to various risk factors in patients with
stable angina pectoris.
AB - OBJECTIVES: To evaluate relationships between psychosocial variables and common
risk factors such as age, concomitant diseases (hypertension, diabetes mellitus,
myocardial infarction, heart failure) and smoking habits in patients with stable
angina pectoris. SETTING: University Hospital. SUBJECTS: Participants in the
Angina Prognosis Study in Stockholm (APSIS), which comprised 809 patients (248
females) <70 years of age, with chronic stable angina pectoris, of whom 767 (236
females) participated in the present report. Patients with angina pectoris
occurring only at rest constituted one group, patients with angina pectoris on
effort with or without angina at rest were stratified according to signs of
marked ischaemia on exercise and/or clinical signs of heart failure. METHODS:
Psychosomatic symptoms, job strain, Type-A behaviour, sleep disturbances and
overall life satisfaction were evaluated by a structured interview, which also
included questions regarding how the patients usually felt, and health related
problems, according to a standardized check-list. RESULTS: Age correlated with
several psychosomatic symptoms and tendency to worry. When adjusted for age and
sex, patients with previous myocardial infarction and heart failure described
more psychosomatic symptoms, but worried less about the future than patients
without these diseases. In the group with angina pectoris at rest only there were
fewer smokers than amongst other groups, regardless of risk stratification.
CONCLUSIONS: Smoking habits and concomitant diseases influence psychosocial
variables in patients with stable angina pectoris. The severity of angina
pectoris does not seem to relate to life satisfaction and attitudes towards the
future.
PMID- 10692088
TI - Clinical assessment of suspected deep vein thrombosis: comparison between a score
and empirical assessment.
AB - OBJECTIVES: To assess the accuracy and agreement of two methods of clinical
evaluation: a formal score based on a number of items of fixed value (the so
called Wells' score), and an empirical assessment based on a predefined list of
items that can be weighted individually. Clinical probability is essential to
manage suspected deep vein thrombosis (DVT) and should be assessed before any
diagnostic test. DESIGN: An open, nonrandomised, one-centre study. SETTING: One
centre in Switzerland (a university hospital delivering primary-tertiary care).
SUBJECTS: Two hundred and seventy outpatients with a prevalence of DVT of 21.1%
(final diagnosis), out of an initial population of 328 patients, of which 52 had
to be excluded because of a history of DVT (score not applicable) or because of
insufficient clinical information (n = 6). RESULTS: Agreement between the two
assessment tools was poor (kappa value of 0.32), but accuracy was excellent, with
a prevalence of DVT of 1.3%, 18.1%, and 100% (empirical assessment), and 3.2%,
19.4%, and 73.9% (Wells' score), for a low, intermediate or high clinical
probability estimate, respectively. The main differences between the two methods
were that (i) the empirical method performed slightly better in categorizing
patients in the high probability class, and (ii) Wells' score categorized more
patients in the low probability class. When applied to two validated diagnostic
strategies, the empirical assessment required slightly fewer phlebograms in both
strategies, and Wells' score required fewer repeat ultrasonograms (in the
strategy that requires this procedure). CONCLUSIONS: Clinical probability
assessment can be done with a similar accuracy either empirically or using a
score. Institutions should incorporate clinical probability assessment with
either method depending upon their diagnostic strategy for suspected DVT.
PMID- 10692089
TI - Silent cerebral infarction: a potential risk for pneumonia in the elderly.
AB - OBJECTIVE: To determine whether patients who have silent cerebral infarction are
more likely to develop pneumonia than are controls without silent cerebral
infarction. DESIGN: We examined 269 community-residing participants of the senior
day-care centre without history of previous stroke, and then followed them over a
two-year period to assess pneumonia. On the basis of computerized tomography
scans, they were divided into two groups: no infarction (n = 102) and cerebral
hemispheric infarction (n = 167). Cerebral infarcts were further divided into
deep and superficial infarcts. RESULTS: The incidence of pneumonia was
significantly higher in subjects with silent cerebral infarction (19.8%) than in
controls (4. 9%) (odds ratio, 4.67 [95% CI, 1.87-11.67]; P < 0.01). Deep infarcts
were more closely associated with the incidence of pneumonia (29.1%) than
superficial infarcts (7.6%) (odds ratio, 5.00 [CI, 1.91-13.08]; P < 0.01).
CONCLUSIONS: Elderly subjects with silent cerebral infarction were more likely to
develop pneumonia than were controls without silent cerebral infarction. Amongst
hemispheric silent cerebral infarcts, those located in the deep brain structures
may be an important predictor of the development of pneumonia.
PMID- 10692090
TI - Commonly recommended daily intake of vitamin D is not sufficient if sunlight
exposure is limited.
AB - OBJECTIVES: Sunlight exposure of the skin is known to be the most important
source of vitamin D. The aims of this study were: (i) to estimate vitamin D
status amongst sunlight-deprived individuals (veiled Arab women, veiled ethnic
Danish Moslem women and Danish controls); and (ii) through food intake analysis
to estimate the oral intake of vitamin D necessary to keep a normal vitamin D
status in sunlight-deprived individuals. DESIGN: Cross-sectional study amongst
randomly selected Moslem women of Arab origin living in Denmark. Age-matched
Danish women were included as controls. To control for racial differences, a
group of veiled ethnic Danish Moslem women (all Caucasians) was included.
SETTING: Primary Health Care Centre, City Vest and Department of Endocrinology
and Metabolism C, University Hospital of Aarhus, Aarhus Amtssygehus, Aarhus,
Denmark. SUBJECTS: Sixty-nine Arab women (60 veiled, nine non-veiled) and 44 age
matched Danish controls were randomly selected amongst patients contacting the
primary health care centre for reasons other than vitamin D deficiency. Ten
ethnic Danish Moslem women were included through a direct contact with their
community. MAIN OUTCOME MEASURES: Serum levels of 25-hydroxyvitamin D were used
as estimates of vitamin D status. Intact parathyroid hormone (PTH) was used to
control for secondary hyperparathyroidism. Alkaline phosphatase and bone-specific
alkaline phosphatase were used as markers for osteomalacic bone involvement. Oral
intake of vitamin D and calcium were estimated through a historical food intake
interview performed by a trained clinical dietician. RESULTS: Veiled Arab women
displayed extremely low values of 25-hydroxyvitamin D: 7.1 +/- 1.1 nmol L-1,
compared with 17.5 +/- 2. 3 (P < 0.002) in ethnic Danish Moslems and 47.1 +/- 4.6
(P < 10-17) in Danish controls. PTH was increased amongst veiled Arab women: 15.
6 +/- 1.8 pmol L-1, compared with 5.7 +/- 1.4 in ethnic Danish Moslems and 2.7 +/
0.3 (P < 10-6) in Danish controls. The vitamin D intake (including food
supplementation) was very low amongst Arab women: 1.04 microg day-1, compared
with 13.53 amongst ethnic Danish Moslems and 7.49 amongst Danish controls (P <
0.0005). CONCLUSIONS: Severe vitamin D deficiency is prevalent amongst sunlight
deprived individuals living in Denmark. In veiled Arab women, vitamin D
deficiency is the result of a combination of limitations in sunlight exposure and
a low oral intake of vitamin D. The oral intake of vitamin D amongst veiled
ethnic Danish Moslems was, however, very high, at 13.53 microgram (approximately
600 IU), but they were still vitamin D-deficient. Our results suggest that the
daily oral intake of vitamin D in sunlight-deprived individuals should exceed 600
IU; most probably it should be 1000 IU day-1 to secure a normal level of 25
hydroxyvitamin D. This finding is in contrast with the commonly used RDA
(recommended daily allowance) for adults in Europe: 200 IU day-1.
PMID- 10692091
TI - Calcaneal ultrasound measurements are determined by age and physical activity.
Studies in two Swedish random population samples.
AB - AIM: To present reference values and correlations with body composition, blood
variables and lifestyle factors. SUBJECTS: Two random population samples from
Goteborg, Sweden, one comprising 184 men and 455 women aged 25-64 years (MONICA)
and the other 860 women aged 55-82 years (BEDA) were studied. METHODS: Calcaneal
ultrasound measurement (LUNAR Achilles) and bioimpedance were measured. Smoking
habits, coffee consumption, physical activity, psychological stress, education
and marital status, as well as blood lipids, blood pressure, and fractures were
studied. RESULTS: Broadband ultrasound attenuation and stiffness were higher in
men than in women (P < 0. 001), but speed of sound did not differ between sexes.
Speed of sound, broadband ultrasound attenuation and stiffness decreased with age
(P < 0.001). In both sexes speed of sound, broadband ultrasound attenuation and
stiffness correlated positively to body size variables, and negatively with
smoking in women after adjustment for age. Speed of sound, broadband ultrasound
attenuation and stiffness were positively related to physical activity in both
sexes, and these relationships were the only ones that remained in multivariate
analyses in addition to age (negative). Osteoporotic fractures increased with
age. Speed of sound, broadband ultrasound attenuation and stiffness were lower
amongst women with osteoporotic fractures. CONCLUSION: Speed of sound, broadband
ultrasound attenuation and stiffness decreased with age and increased with
physical activity, but body weight and height were not correlated in multivariate
analyses. Osteoporotic fractures increased with age and were associated with
lower calcaneal ultrasound values.
PMID- 10692092
TI - Increased plasma concentrations of TGF-beta1 after hormone replacement therapy.
AB - OBJECTIVES AND DESIGN: Hormone replacement therapy (HRT) in postmenopausal women
may reduce the cardiovascular risk. A dominant protective role of transforming
growth factor beta (TGF-beta1) on coronary arteries has been proposed. Lp(a)
lipoprotein may block the activation of latent TGF-beta1. Given this background,
we examined the effects of HRT on TGF-beta1 and Lp(a) lipoprotein in 99
postmenopausal women. The women had angiographically documented coronary heart
disease (CHD) and were randomized to either sequential transdermal 17beta
oestradiol for 14 weeks and then medroxyprogesterone (MPA) for 14 days (HRT) or
to a control group (C). RESULTS: Serum levels of TGF-beta1 were increased in the
HRT group compared with the C group after 3 months' treatment and this effect was
sustained after 12 months. There was a significant reduction in Lp(a) lipoprotein
serum levels after 3 months' treatment in the HRT group compared with the C
group. However, after 12 months, no significant difference in changes in Lp(a)
lipoprotein serum levels was detected between the two groups. CONCLUSION: The
novel observation that transdermal 17beta-oestradiol in postmenopausal women
increases levels of TGF-beta1 and lowers the concentration of Lp(a) lipoprotein
suggests yet another possible mechanism for the cardioprotective effect of HRT.
Whereas combination therapy of oestradiol and MPA preserves the beneficial effect
on TGF-beta1, it reduces the unopposed oestradiol effects on Lp(a) lipoprotein.
PMID- 10692093
TI - Plasma total homocysteine levels in subjects with hyperinsulinemia.
AB - OBJECTIVES: Hyperhomocysteinemia as well as insulin resistance are considered to
be risk factors for the development of coronary artery disease. This study was
aimed at determining whether any relationship between plasma insulin and glucose
levels and total plasma homocysteine (tHcy) concentrations exists in a population
based survey performed 10 years apart. DESIGN AND SETTING: A cross-sectional
study was undertaken during the years 1986-87 to examine risk factors for
diabetes and for coronary artery disease (CAD) in the Jewish population of
Jerusalem. Ten years later two groups of individuals were invited for re
examination. SUBJECTS: Two groups of individuals were examined: the first one
consisted of nondiabetic subjects (n = 86), who had hyperinsulinemia 10 years
previously (at the first visit), the second group consisted of normoinsulinemic
nondiabetic individuals (n = 265) who had initially normal glucose and insulin
levels. MAIN OUTCOME MEASURES: Metabolic, biochemical and anthropomorphic
features were determined. Fasting and post load glucose, as well as insulin
concentrations on fasting and 2 h post glucose load were measured at the first
and second visits. Plasma tHcy and folic acid were determined only at the second
visit. RESULTS: The results demonstrated a significant negative correlation
between plasma tHcy levels and insulin levels at the second visit. No difference
was found in folic acid levels between these two groups. CONCLUSIONS: In general,
hyperinsulinemia and hyperhomocysteinemia are both related to an increased
incidence of CAD. In our population most of the subjects examined had tHcy levels
within the normal range and only a few demonstrated very high levels. However,
negative association between insulin levels and tHcy concentrations was found.
Possible explanations for this finding are discussed.
PMID- 10692094
TI - Coronary vasospasm associated with uncontrolled carcinoid tumour.
AB - We report on a 74-year-old carcinoid patient who, following acute myocardial
infarction (MI) and percutaneous transluminal coronary angioplasty, suffered
recurrent episodes of chest pain and ST-segment elevation on ECG. This was
accompanied by elevation of urinary 5-hydroxy-indole acetic acid. A review of the
patient's file revealed that during the 3 weeks prior to the MI, she had been
treated inadvertently with a fivefold lower dosage of octreotide. Following the
correction of octreotide dosage, episodes of chest pain resolved immediately. We
therefore suggest that this patient suffered from recurrent coronary vasospasm
due to uncontrolled carcinoid tumour.
PMID- 10692095
TI - In this issue
PMID- 10692096
TI - Antibodies to human papillomavirus type 5 are generated in epidermal repair
processes.
AB - We reported previously that patients with psoriasis harbored at a very high
frequency DNA sequences of the oncogenic human papillomavirus type 5 (HPV5)
associated with epidermodysplasia verruciformis. Moreover anti-HPV5 antibodies
were detected in 25% of the cases. Our aim was to find out whether keratinocyte
hyperproliferation and/or autoimmunity could be responsible for HPV5 expression
in psoriasis. We found that epidermal repair in patients with extensive second
degree burns (n = 19) is frequently associated with the generation of anti-HPV5
antibodies. In patients with autoimmune bullous diseases (n = 118), a condition
in which keratinocyte proliferation is involved in repair mechanisms, the
prevalence of anti-HPV5 antibodies (15%-25%) was similar to that reported in
psoriasis and significantly higher than that (5%) observed in individuals with no
known history of human papillomavirus infection (n = 119). A high detection rate
(57.9%) of HPV5 DNA was observed in patients with bullous diseases. Anti-HPV5
antibodies were found in patients with autoimmune connective tissue disorders
with cutaneous involvement (n = 40) as frequently as in patients with bullous
diseases. HPV5 DNA was detected in one of the 10 patients studied. In contrast,
the prevalence of anti-HPV5 antibodies in patients with autoimmune neurological
disorders (n = 47) and in patients with common warts (n = 28) or invasive
carcinomas of the skin (n = 40) was as low as in the general population. It is
worth stressing that a similar prevalence of antibodies against HPV1 was found in
all groups studied. Our data strongly suggest that extensive keratinocyte
proliferation is a major factor for the generation of anti-HPV5 antibodies and
that autoimmunity may contribute to this phenomenon. It remains to be determined
whether HPV5 and other human papillomavirus genotypes associated with
epidermodysplasia verruciformis contribute to the hyperproliferation of
keratinocytes occurring in epidermal repair and in psoriasis.
PMID- 10692097
TI - Signaling of mechanical stretch in human keratinocytes via MAP kinases.
AB - Cells within human skin are permanently exposed to mechanical stretching. Here we
present evidence that alterations in cell shape trigger biochemical signaling via
MAP kinases in human keratinocytes. In an in vitro attempt we demonstrate a fast
but transient activation of extracellular signal-regulated kinases 1/2 in
response to cell stretch. This activation is reversed by preincubation with
functional blocking antibodies directed towards beta1-integrins. As a second
member of MAP kinases, stress-activated protein kinase/c-JUN NH2-terminal kinase
was activated in a slower fashion, peaking at 1 h after the initial stimulus. The
delay in signal transmission suggests that extracellular signal-regulated kinases
1/2 and stress-activated protein kinase/c-JUN NH2-terminal kinase do not share
the same signaling pathway. p38 was not activated by cell stretching. The
contribution of cytoskeletal elements in signal perception and transduction was
evaluated by selective disruption of either actin filaments, microtubules, or
keratin filaments but showed no clear effect on stretch-induced activation of
extracellular signal-regulated kinases 1/2 and stress-activated protein kinase/c
JUN NH2-terminal kinase. In conclusion we found evidence of a cell-shape
dependent activation of MAP kinases in human keratinocytes disclosing beta1
integrins as putative mechano-transducers. It is likely that alterations of skin
mechanics in vivo underlying pathogenic processes like wound formation and
healing trigger physiologic responses via the MAP kinase pathway.
PMID- 10692098
TI - Adhesive properties of human basal epidermal cells: an analysis of keratinocyte
stem cells, transit amplifying cells, and postmitotic differentiating cells.
AB - The basal layer of human epidermis is a heterogeneous population of proliferative
and differentiating cells that can be divided into at least three functionally
discrete compartments: keratinocyte stem cells, transit amplifying cells, and
postmitotic differentiating cells. Basal cells adhere to the underlying basement
membrane via integrins, and although decreased adhesion is a key event in
epidermal differentiation, the specific role of particular integrins is poorly
understood. We report here on the comparative expression and function of the
beta1 versus alpha6beta4 integrins in keratinocyte stem cells, transit amplifying
cells, and postmitotic differentiating cells of neonatal human foreskin
epidermis. Adhesion assays demonstrate that both keratinocyte stem cells and
transit amplifying cells comprise rapidly adhering cells that exhibit high levels
of functional beta1 and alpha6beta4 integrins. Interestingly, a proportion of
basal cells that have begun to differentiate in vivo within the basal layer as
determined by their expression of the differentiation-specific markers K10 and
involucrin also retain high levels of activated beta1 integrin, but downregulate
alpha6beta4 expression selectively (termed alpha6dimbeta1bri). These cells also
retain their adhesive capacity, indicating that induction of differentiation in
vivo does not correlate with decreased beta1 integrin expression or function. We
have previously reported on the use of alpha6 integrin in conjunction with a
proliferation associated marker (10G7 ag) to separate keratinocyte stem cells
(phenotype alpha6bri10G7dim) from other basal cells (Li et al. Proc Natl Acad Sci
95:3902-3907 1998). A comparison of the long-term proliferative potential of
beta1bri10G7dim cells with alpha6bri10G7dim showed that selection of
alpha6bri10G7dim allows the isolation of a purer fraction of keratinocyte stem
cells.
PMID- 10692099
TI - Kinesin and kinectin can associate with the melanosomal surface and form a link
with microtubules in normal human melanocytes.
AB - Microtubuli play an important role in the organization of organelles and membrane
traffic. They are present in melanocytic dendrites through which melanosomes are
transported towards keratinocytes. Besides the actin-based motility systems,
microtubuli-associated motor proteins also play a critical role in melanosome
movement, as has recently been confirmed in mouse melanocytes. We investigated
the in vitro expression of two forms of human conventional kinesin and its
receptor kinectin in normal human epidermal melanocytes, keratinocytes, and
dermal fibroblasts by reverse transcription polymerase chain reaction and
northern blot analysis. In an attempt to gain insight into the subcellular
distribution of kinesin and kinectin in melanocytes, double immunofluorescent
staining and immunogold electron microscopy were performed. In all studied skin
cells ubiquitous and neuronal kinesin are expressed, as well as the kinectin
receptor. Immunofluorescent staining shows distinct but partially overlapping
distributions for kinesin heavy chain and melanosomes, suggesting that kinesin is
associated with some but not all of the melanosomes. Similar observations for
kinectin indicate that this receptor can colocalize with melanosomes, which was
confirmed by immunoelectron microscopy. The latter technique allowed us to
demonstrate a close association between kinesin heavy chain, microtubuli, and
melanosomes. The combined data from reverse transcription polymerase chain
reaction, northern blot analysis, double immunofluorescent staining, and
immunogold electron microscopy suggest that kinesins and kinectin have an
important role in microtubuli-based melanosome transport in human melanocytes.
PMID- 10692100
TI - Pro-opiomelanocortin-related peptides, prohormone convertases 1 and 2 and the
regulatory peptide 7B2 are present in melanosomes of human melanocytes.
AB - Recently, it has been shown that alpha-melanocyte stimulating hormone can
directly activate tyrosinase by removing the allosteric regulator 6(R)-L-erythro
5,6,7,8 tetrahydrobiopterin resulting in a stable alpha-melanocyte stimulating
hormone/6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin complex. As melanin production
occurs in the melanosome, a specific organelle of the melanocyte, it seemed
important to investigate whether these organelles themselves actually produce pro
opiomelanocortin-related peptides in their acidic environment. The presence of
alpha-melanocyte stimulating hormone and adrenocorticotropin in the epidermis and
melanocytes has been shown by several investigators. In order to follow possible
pro-opiomelanocortin processing in the melanosome, human melanocytes were
established in MCDB 153 medium and utilized for immunohistochemistry, immunogold
electron microscopy, and western blotting. For this purpose antibodies against
alpha-melanocyte stimulating hormone, adrenocorticotropin, prohormone convertases
1 and 2 (PC1 and PC2) and the PC2 regulatory protein 7B2 were used. Our results
demonstrated the presence of the entire system for pro-opiomelanocortin
processing in the melanosome. Considering the pH optima of these convertases, the
results are in agreement with an autocrine intramelanosomal production of pro-
opiomelanocortin-related peptides and an autocrine production and recycling of
the cofactor 6(R)-L- erythro 5,6,7,8 tetrahydrobiopterin in melanocytes. Based on
these novel observations, we would like to propose that the pigmentation process
may not necessarily involve a melanocortin-1 receptor-mediated mechanism.
PMID- 10692101
TI - Kinesin participates in melanosomal movement along melanocyte dendrites.
AB - Movement of melanosomes along melanocyte dendrites is necessary for the transfer
of melanin pigment from melanocytes to basal and suprabasal keratinocytes, an
event critical to epidermal photoprotection and maintenance of normal skin color.
Recent murine data suggest that in melanocyte dendrites the microtubule
associated melanosome movement is bidirectional and that actin-associated myosin
V secures the peripheral melanosomes, preparing them to be transferred to
surrounding keratinocytes. We now report that human melanocytes express high
levels of kinesin, a molecule that participates in microtubule-associated
transport of organelles in other cell types, and that ultrastructurally kinesin
molecules are closely associated with melanosomes. To determine whether kinesin
participates in melanosomal transport, cultured melanocytes were treated with
sense or antisense oligonucleotides complementary to kinesin heavy chain
sequences. Antisense oligonucleotides decreased kinesin protein levels and
inhibited the bidirectional movement of the melanosomes, promoting their backward
movement. Furthermore, guinea pigs were exposed to ultraviolet B irradiation,
known to enhance transport of melanosomes from melanocytes to epidermal
keratinocytes, and then were treated with kinesin sense or antisense
oligonucleotides. The areas that were treated with kinesin antisense
oligonucleotides showed significantly less pigmentation clinically and
histologically than control (sense) oligonucleotide-treated areas. As observed
ultrastructurally, in antisense-treated areas melanosomes remained in melanocyte
dendrites but over several days were not transferred to the surrounding
keratinocytes. Our study supports a major role for kinesin in microtubule
associated anterograde melanosomal transport in human melanocyte dendrites.
PMID- 10692102
TI - Normal growth and differentiation in a spontaneously immortalized near-diploid
human keratinocyte cell line, NIKS.
AB - We report the isolation and characterization of a spontaneously immortalized
human keratinocyte cell line, NIKS. The cell line is not tumorigenic in athymic
nude mice and maintains cell-type-specific requirements for growth in vitro. NIKS
cells express steady-state levels of transforming growth factor-alpha,
transforming growth factor-beta1, epidermal growth factor receptor, c-myc, and
keratin 14 mRNAs comparable with the parental BC-1-Ep keratinocyte strain. BC-1
Ep and NIKS keratinocytes produce similar levels of cornified envelopes and
nucleosomal fragmentation in response to loss of substrata attachment. DNA
fingerprinting results confirm that the NIKS cells originated from the parental
BC-1-Ep keratinocytes. NIKS cells contain 47 chromosomes due to an extra
isochromosome of the long arm of chromosome 8, and the near-diploid karyotype
appears to be stable with repeated passage. A fully stratified squamous
epithelium is formed by the NIKS keratinocytes in organotypic culture.
Ultrastructural analysis of both the parental and immortalized keratinocytes
reveals abundant desmosomes, hemidesmosomes, and the production of a basal
lamina. Our findings with the NIKS cells support the observation that spontaneous
immortalization is not linked to alterations in squamous differentiation or the
ability to undergo apoptosis. The NIKS human keratinocyte cell line is an
important new tool for the study of growth and differentiation in stratified
squamous epithelia.
PMID- 10692103
TI - Dual-mode regulation of hair growth cycle by two Fgf-5 gene products.
AB - As the result of alternative mRNA splicing, Fgf-5, the gene encoding fibroblast
growth factor-5, translates to both long and short forms of the protein,
respectively, designated fibroblast growth factor-5 and fibroblast growth factor
5S. We previously showed that localization of fibroblast growth factor-5 and the
level of fibroblast growth factor-5S in murine skin are hair-cycle dependent. In
this study, we examined the effect of fibroblast growth factor-5 and fibroblast
growth factor-5S on the hair growth cycle in mice. Once the anagen phase of the
hair growth cycle was induced in the dorsal skin by depilation during telogen,
and effects of subcutaneous injection of fibroblast growth factor-5 and
fibroblast growth factor-5S into the affected region were analyzed. We found that
fibroblast growth factor-5 inhibited hair growth during anagen and promoted the
transition from anagen to catagen. Interestingly, whereas fibroblast growth
factor-5S alone exerted no effect on hair growth, it significantly inhibited the
catagen-promoting activity of fibroblast growth factor-5 when the two proteins
were injected simultaneously. Because neither fibroblast growth factor-5 nor
fibroblast growth factor-5S affected skin thickness, it is postulated that
changes in skin thickness during hair cycle are separately regulated by factors
other than those regulating hair and follicle growth. The present results,
together with our earlier findings that fibroblast growth factor-5-producing
cells gather around dermal papillae during catagen, whereas fibroblast growth
factor-5S is abundantly expressed in the hair follicles only during the latter
half of anagen, suggests that the mouse hair growth cycle is regulated by the two
Fgf-5 gene products acting in concert: fibroblast growth factor-5 induces
catagen, whereas fibroblast growth factor-5S antagonizes this activity during
anagen.
PMID- 10692104
TI - Characterization of a 300 kbp region of human DNA containing the type II hair
keratin gene domain.
AB - Screening of an arrayed human genomic P1 artificial chromosome DNA library by
means of the polymerase chain reaction with a specific primer pair from the human
type II hair keratin hHb5 yielded two P1 artificial chromosome clones covering
approximately 300 kb of genomic DNA. The contig contained six type II hair
keratin genes, hHb1-hHb6, and four keratin pseudogenes psihHbA-psihHbD. This hair
keratin gene domain was flanked by type II epithelial keratins K6b/K6hf and K7,
respectively. The keratin genes/pseudogene are 5-14 kbp in size with intergenic
distances of 5-19 kbp of DNA and do not exhibit a single direction of
transcription. With one exception, type II hair keratin genes are organized into
nine exons and eight introns, with strictly conserved exon-intron boundaries. The
functional hair keratin genes are grouped into two distinct subclusters near the
extremities of the hair keratin gene domain. One subcluster encodes the highly
related hair keratins hHb1, hHb3, and hHb6; The second cluster encodes the
structurally less related hair keratins hHb2, hHb4, and hHb5. Reverse
transcription-polymerase chain reaction shows that all hair keratin genes are
expressed in the hair follicle. Pseudogene psihHbD is also transcriptionally
expressed, albeit with alterations in splicing and frameshift mutations, leading
to premature stop codons in the splice forms analyzed. Evolutionary tree analysis
revealed a divergence of the type II hair keratin genes from the epithelial
keratins, followed by their segregation into the members of the two subclusters
over time. We assume that the approximately 200 kbp DNA domain contains the
entire complement of human type II hair keratin genes.
PMID- 10692105
TI - New function for NF1 tumor suppressor.
AB - The expression and subcellular localization of neurofibromatosis type 1 tumor
suppressor was studied in keratinocytes induced to differentiate by increased
Ca2+ concentration of the culture medium. Differentiating keratinocytes became
intensely immunoreactive for neurofibromatosis type 1 protein, which was
apparently associated with cellular fibrils. Double immunolabeling with
antibodies to cytokeratin 14 and neurofibromatosis type 1 protein suggested an
association of intermediate type cytoskeleton and neurofibromatosis type 1
protein. The presence of neurofibromatosis type 1 protein in cell preparations
treated with cytoskeletal buffer indicated a high affinity interaction between
intermediate filaments and neurofibromatosis type 1 protein. Further studies
utilizing double immunolabelings revealed that the intense neurofibromatosis type
1 tumor suppressor signal on intermediate filaments was temporally limited to the
period in keratinocyte differentiation in which the formation of desmosomes takes
place. Keratinocytes were also cultured from nine patients with type 1
neurofibromatosis and were studied with respect to cell morphology, and
association of neurofibromatosis type 1 protein with intermediate cytoskeleton.
The results showed that keratinocytes cultured from patients with
neurofibromatosis type 1 displayed a highly variable cell size and morphology
compared to controls. The latter findings represent predicted alterations in a
situation where cytoskeletal organization is disturbed. Furthermore,
differentiating neurofibromatosis type 1 keratinocytes were characterized by a
reduced number of cytokeratin bundles that were decorated neurofibromatosis type
1 protein. The results of this study suggest that neurofibromatosis type 1 tumor
suppressor exerts its effects in part by controlling organization of cytoskeleton
during the formation of cellular contacts.
PMID- 10692106
TI - Vitamin A antagonizes decreased cell growth and elevated collagen-degrading
matrix metalloproteinases and stimulates collagen accumulation in naturally aged
human skin.
AB - Damage to human skin due to ultraviolet light from the sun (photoaging) and
damage occurring as a consequence of the passage of time (chronologic or natural
aging) are considered to be distinct entities. Photoaging is caused in part by
damage to skin connective tissue by increased elaboration of collagen-degrading
matrix metalloproteinases, and by reduced collagen synthesis. As matrix
metalloproteinase levels are known to rise in fibroblasts as a function of age,
and as oxidant stress is believed to underlie changes associated with both
photoaging and natural aging, we determined whether natural skin aging, like
photoaging, gives rise to increased matrix metalloproteinases and reduced
collagen synthesis. In addition, we determined whether topical vitamin A
(retinol) could stimulate new collagen deposition in sun-protected aged skin, as
it does in photoaged skin. Sun-protected skin samples were obtained from 72
individuals in four age groups: 18-29 y, 30-59 y, 60-79 y, and 80+ y. Histologic
and cellular markers of connective tissue abnormalities were significantly
elevated in the 60-79 y and 80+ y groups, compared with the two younger age
groups. Increased matrix metalloproteinase levels and decreased collagen
synthesis/expression were associated with this connective tissue damage. In a
separate group of 53 individuals (80+ y of age), topical application of 1%
vitamin A for 7 d increased fibroblast growth and collagen synthesis, and
concomitantly reduced the levels of matrix-degrading matrix metalloproteinases.
Our findings indicate that naturally aged, sun-protected skin and photoaged skin
share important molecular features including connective tissue damage, elevated
matrix metalloproteinase levels, and reduced collagen production. In addition,
vitamin A treatment reduces matrix metalloproteinase expression and stimulates
collagen synthesis in naturally aged, sun-protected skin, as it does in photoaged
skin.
PMID- 10692107
TI - Keratin 4 upregulation by retinoic acid in vivo: a sensitive marker for retinoid
bioactivity in human epidermis.
AB - Retinoids affect keratinocyte differentiation and modulate the expression of many
epidermal proteins, among them cellular retinoic acid-binding protein II and the
family of cytokeratins. The upregulation of the former protein is a well-known
phenomenon, whereas the retinoid-induced regulation of epidermal keratin
expression is more complex and only partially understood. We studied the effect
of topical retinoids on the expression in healthy skin of cellular retinoic acid
binding protein II, tazarotene-induced genes 1 and 2, several epidermal keratins
(K1, K2e, and K10), and two mucous keratins (K4 and K13) known to appear in
epidermis under certain abnormal conditions. Reverse transcription-polymerase
chain reaction experiments showed that the K4 expression was the one most overtly
induced by 2 wk of open treatment with 0.05% of retinoic acid and tazarotene.
Using real-time quantitative polymerase chain reaction (TaqMan) and normalization
of the mRNA values to beta-actin, the increase in K4 was found to be 100-1000
fold. In comparison, the expression of K13 and cellular retinoic acid-binding
protein II was increased 10-50-fold, the K1 and K10 mRNA levels remained
unchanged, and the K2e level decreased by a factor of 100-1000. In parallel
biopsies, immunohistochemistry showed no change in K1, K2e, or K10 staining, but
a strong de novo appearance of K4 in the granular layer after retinoid treatment.
In a separate study, occlusive application of 0.025% retinoic acid in four
healthy subjects produced a maximal K4 mRNA signal after 48 h and strong K4
staining after 80 h. Finally, a dose-response study showed that the de novo
appearance of K4 can be utilized as a sensitive test for retinoid bioactivity in
epidermis in vivo.
PMID- 10692108
TI - Suppression of vitamin D receptor and induction of retinoid X receptor alpha
expression during squamous differentiation of cultured keratinocytes.
AB - To gain more insight in the role of the vitamin D system in epidermal
differentiation, we studied the expression of the vitamin D receptor and its
heterodimeric partner retinoid X receptor alpha in cultured normal human
keratinocytes during squamous differentiation, as triggered by different
approaches. Northern and western blot analysis allowed us to investigate mRNA and
protein levels of these nuclear receptors and of markers for growth control (c
myc, cyclin D1, p21WAF1) and differentiation (keratinocyte transglutaminase,
small proline rich proteins). Growing cells to postconfluence was a potent
stimulus for growth arrest and differentiation with concomitant suppression of
vitamin D receptor and induction of retinoid X receptor alpha, at both the mRNA
and the protein level. These changes could be prevented by concomitant treatment
with epidermal growth factor or keratinocyte growth factor. Subjecting the cells
to a calcium switch leading to stratification and differentiation lowered vitamin
D receptor protein levels without affecting vitamin D receptor mRNA and induced
both retinoid X receptor alpha mRNA and protein. Interferon-gamma and the
phorbolester 12-O-tetradecanoyl phorbol 13-acetate, two well-known inducers of
keratinocyte differentiation, both inhibited vitamin D receptor expression but
only interferon-gamma induced retinoid X receptor alpha. The decreased vitamin D
receptor expression was accompanied by reduced vitamin D responsiveness (as
assessed by 24-hydroxylase mRNA induction) in postconfluent, high calcium, and 12
O-tetradecanoyl phorbol 13-acetate treated keratinocytes but not with interferon
gamma treatment. Taken together, our results associate vitamin D receptor
expression with undifferentiated, proliferating keratinocytes, whereas retinoid X
receptor alpha expression appears to be related to the differentiated phenotype.
Therefore, proliferating and differentiating keratinocytes may be differentially
targeted by active vitamin D metabolites.
PMID- 10692109
TI - Protective role of copper, zinc superoxide dismutase against UVB-induced injury
of the human keratinocyte cell line HaCaT.
AB - On the basis of our recent observation that copper, zinc-superoxide dismutase and
manganese-superoxide dismutase change differently following a single exposure to
ultraviolet-B irradiation in the human keratinocyte cell line HaCaT, we have
examined the possible role of endogenous copper,zinc-superoxide dismutase or
manganese-superoxide dismutase against ultraviolet-B-induced reactive-oxygen-
species-mediated keratinocyte injury in vitro. To evaluate the individual
defensive roles of copper, zinc-superoxide dismutase and manganese-super-oxide
dismutase, we treated HaCaT cells with diethyldithiocarbamate, a chelating agent
of ionic copper that inactivates copper,zinc-superoxide dismutase activities,
tumor necrosis factor alpha, which enhances manganese-superoxide dismutase
levels, or transforming growth factor beta1, which inhibits manganese-superoxide
dismutase levels. After the treatment with each reagent, HaCaT cells in the three
different conditions were exposed to a single dose of ultraviolet-B irradiation.
We assessed ultraviolet-B-induced cytotoxicity by measuring both lactate
dehydrogenase leakage and cell viability using trypan blue dye exclusion assay.
The lactate dehydrogenase leakage in the supernatant from damaged HaCaT cells
whose copper,zinc-superoxide dismutase levels were inactivated by
diethyldithiocarbamate was significantly increased and the cell viability was
significantly decreased in comparison with untreated groups at 8 and 24 h after
ultraviolet-B irradiation. On the other hand, the lactate dehydrogenase release
and cell viability for HaCaT cells whose manganese-superoxide dismutase levels
were enhanced by tumor necrosis factor alpha or inhibited by transforming growth
factor beta1 showed no significant difference from untreated groups. Furthermore,
increased production of intracellular peroxides in HaCaT cells treated with
diethyldithiocarbamate was observed by flow cytometric analysis at 8 h after
ultraviolet-B irradiation. These results suggest that copper,zinc-superoxide
dismutase may play a primary protective role against ultraviolet-B-induced injury
of the human keratinocyte cell line HaCaT.
PMID- 10692110
TI - Ultraviolet B-induced suppression of immune responses in interleukin-4-/- mice:
relationship to dermal mast cells.
AB - Ultraviolet B radiation is immunosuppressive by multiple mechanisms. In
interleukin-4-/- mice, ultraviolet B radiation was not able to suppress delayed
type hypersensitivity or contact hypersensitivity responses when the sensitizing
antigen was applied to nonirradiated sites. In contrast, ultraviolet B
significantly suppressed contact hypersensitivity responses to haptens applied to
irradiated sites in interleukin-4-/- mice. In mast cell depleted Wf/Wf mice,
ultraviolet B radiation also significantly suppressed contact hypersensitivity
responses to sensitizing antigens applied to irradiated but not to unirradiated
sites. In both interleukin-4-/- mice and Wf/Wf mice, the mast cell product,
histamine, was immunosuppressive implicating mast cells as the dysfunctional cell
in interleukin-4-/- mice. The prevalence of dermal mast cells was similar in wild
type and interleukin-4-/- mice. Dermal mast cells of interleukin-4-/- mice,
however, express very low levels of c-kit and did not significantly degranulate
in response to ultraviolet B. Ultraviolet radiation induced significant and
similar levels of serum interleukin-10 in wild-type and interleukin-4-/- mice. We
conclude that interleukin-4 indirectly affects ultraviolet B suppression of
contact hypersensitivity and delayed-type hypersensitivity responses to
sensitizing antigens applied at sites other than those irradiated by providing a
critical differentiative signal for dermal mast cells. This study further
emphasizes the central role of mast cells in the initial processes by which
ultraviolet B radiation is immunomodulatory for immune responses to sensitizing
antigens applied to nonirradiated sites.
PMID- 10692111
TI - p53-dependent apoptosis in melanoma cells after treatment with camptothecin.
AB - Cutaneous malignant melanoma is a life-threatening cancer with poor prognosis due
to a high metastasis potential. The main obstacle in treatment of metastatic
melanoma is the resistance to chemotherapy. Recent studies indicated that
apoptosis is a common mechanism of action for various cytotoxic agents. As p53
plays an important part in apoptosis, we investigated the role of p53 in
chemosensitivity of melanoma cells. Previously, we found that melanoma cell lines
containing wild-type p53 have significantly higher response rates to chemotherapy
than cell lines with a mutant p53 gene. To confirm the role of p53 in melanoma
chemosensitivity further, we transfected an expression vector, pED1, which
carries a mutant p53 gene, into a wild-type p53 melanoma cell line, MMAN. We
examined the effect of mutant p53 on camptothecin-induced apoptosis and the
expression of genes which are known to be involved in apoptosis or drug
resistance, such as bcl-2, bax, bak, p21waf1, and P-glycoprotein. Our results
indicate that overexpression of the mutant p53 increased the growth rate of MMAN
cells, reduced the sensitivity to camptothecin, and lowered drug-induced
apoptosis by 2-3-fold. Flow cytometry indicated that the camptothecin-induced
apoptosis is not associated with G1 arrest. Furthermore, camptothecin treatment
reduced bcl-2 and P-glycoprotein expression in wild-type p53 MMAN cells, but not
cells overexpressing mutant p53. These results demonstrate that p53 mutational
status is a determinant of melanoma chemosensitivity. p53 may downregulate bcl-2
and P-glycoprotein to induce apoptosis in melanoma cells after chemotherapy.
PMID- 10692112
TI - alpha-melanocyte-stimulating hormone modulates nitric oxide production in
melanocytes.
AB - We have previously observed that melanocytes produce nitric oxide in response to
ultraviolet radiation and lipopolysaccharide and in this study have examined how
these responses are affected by alpha-melanocyte-stimulating hormone. Nitric
oxide production by cultured cells was measured electrochemically in real time
using an ISO-nitric oxide sensor probe. B16 mouse melanoma cells released nitric
oxide in response to lipopolysaccharide and the effects were enhanced in cells
that had been grown in the presence of 10-11-10-9 M alpha-melanocyte-stimulating
hormone prior to stimulation. At concentrations in excess of 10-9 M alpha
melanocyte-stimulating hormone decreased nitric oxide production. Preincubation
with lipopolysaccharide, a well-known inducer of inducible nitric oxide synthase,
also increased nitric oxide production but this response was reduced by alpha
melanocyte-stimulating hormone. alpha-Melanocyte-stimulating hormone also
increased the levels of nitric oxide produced in response to ultraviolet
radiation (20-100 mJ per cm2) in B16 cells. The same effect was seen in human
melanocytes and as this was inhibited by aminoguanidine would appear to involve
an induction of inducible nitric oxide synthase. Reverse transcription-polymerase
chain reaction showed that melanocytic cells express inducible nitric oxide
synthase mRNA. Western blotting analysis and immunocytochemistry confirmed the
presence of inducible nitric oxide synthase protein in B16 cells and FM55 human
melanoma cells and that the levels were increased in response to alpha-melanocyte
stimulating hormone. alpha-Melanocyte-stimulating hormone, however, decreased
inducible nitric oxide synthase protein expression, which occurred in response to
lipopolysaccharide. These results suggest that alpha-melanocyte-stimulating
hormone regulates nitric oxide production in melanocytic cells by modulating the
induction of inducible nitric oxide synthase. Additional experiments showed that
nitric oxide increased melanin production by B16 cells and human melanocytes.
This is in keeping with a melanogenic role for nitric oxide but whether its
production by melanocytes in response to alpha-melanocyte-stimulating hormone is
associated with such a role or whether it has some other significance relating to
melanocyte differentiation or in mediating immunomodulatory actions of alpha
melanocyte-stimulating hormone remains to be seen.
PMID- 10692113
TI - beta-endorphin stimulates cytokeratin 16 expression and downregulates mu-opiate
receptor expression in human epidermis.
AB - It has been reported that opioid peptides modulate the differentiation of normal
human keratinocytes and that mu-opiate receptors are expressed in human
epidermis. The regulation of keratinocyte differentiation is particularly
important in psoriasis, and one of the markers for hyperproliferative and
differentiating skin diseases is cytokeratin 16. The finding that the endogenous
mu-opiate receptor ligand beta-endorphin is increased in serum of patients with
psoriasis indicates that the mu-opiate system may play an important role in the
pathophysiology of the skin. In this study, we addressed the question whether
there is a link between mu-opiate receptor regulation and cytokeratin 16
expression in normal and psoriatic skin. Firstly, we demonstrate that beta
endorphin concentrations between 16 and 1000 nM significantly downregulate mu
opiate receptor expression in epidermis of cultured human skin after 48 h.
Secondly, we show that beta-endorphin regulates cytokeratin 16 expression in the
epidermis of skin organ cultures exposed to 41-125 nM beta-endorphin for 48 h,
leading to elevated cytokeratin 16 production. As expected, the expression of
cytokeratin 16 was detected primarily in the suprabasal layer. The same pattern
was observed in psoriatic lesional skin, i.e., mu-opiate receptor expression was
significantly downregulated and cytokeratin 16 expression upregulated. These
results suggest that the mu-opiate receptor system and its ligand beta-endorphin
are involved in the pathogenesis of psoriasis, especially in terms of
differentiation.
PMID- 10692114
TI - The transepidermal oxygen flux from the environment is in balance with the
capillary oxygen supply.
AB - It has been known since the nineteenth century that oxygen is taken up by the
human skin. With a newly developed sensor it became possible to examine the
influence of the vascular supply on the oxygen flux into the skin, tcJ(O2).
tcJ(O2) was measured optically by determining the oxygen partial pressure
difference, DeltapO2 across a diffusion test membrane, which itself was brought
into close contact to the skin surface. Under these conditions DeltapO2 is
proportional to the tcJ(O2). The skin perfusion was varied by the application of
a hyperemizing ointment on the abdomen of 12 volunteers and by suprasystolic
occlusion at the thigh of 20 volunteers. The tcJ(O2) was measured at a
temperature of 33 degrees C of the humid skin. It was compared with the skin
perfusion monitored by laser Doppler flow, and the capillary oxygen supply
measured by transcutaneous partial pressure of oxygen, tcpO2, at an electrode
temperature of 37 degrees C. The transcutaneous O2 flux produced a distinct
DeltapO2 of 81.8 +/- 8.2 Torr (abdomen) and 72.8 +/- 12.3 Torr (ankle). In
hyperemic skin on the abdomen the O2 flux was reduced (DeltapO2 = 57.7 +/- 10.6
Torr). The tcpO2 increased from 8.7 +/- 10.7 to 35.1 +/- 16.9 Torr. During
suprasystolic occlusion, DeltapO2 increased by 6.4 +/- 2.3 Torr, whereas laser
Doppler flow and tcpO2 decreased significantly. These results indicate that the
total oxygen supply of the epidermis and the upper dermis is guaranteed even if
the perfusion varies.
PMID- 10692115
TI - Regulation of cutaneous allergic reaction by odorant inhalation.
AB - Olfactory stimuli modulate emotional conditions and the whole body immune system.
Effects of odorant inhalation on cutaneous immune reaction were examined. Contact
hypersensitivity to 2,4, 6-trinitrochlorobenzene was elicited in C57BL/6 mice.
The reaction was suppressed at both the induction and elicitation phases by
exposure to an odorant, citralva. Topical application of citralva or lyral/lilial
did not affect the reaction. The suppressive effect of citralva was more potent
than that of another odorant, lyral/lilial. Citralva decreased the number of
epidermal Langerhans cells, whereas lyral/lilial had a weak effect. Citralva but
not lyral/lilial induced plasma corticosterone. Glucocorticoid receptor
antagonist abrogated the suppressive effect of citralva on contact
hypersensitivity. Serum interleukin-12 was downregulated by exposure to citralva
or lyral/lilial. These data demonstrate that olfactory stimuli regulate the
cutaneous immune system.
PMID- 10692116
TI - Oxysterols induce differentiation in human keratinocytes and increase Ap-1
dependent involucrin transcription.
AB - Ligands and activators of the nuclear hormone receptor superfamily are important
in the regulation of epidermal development and differentiation. Previously, we
showed that naturally occurring fatty acids, as well as synthetic ligands for the
peroxisome proliferator-activated receptor, induce keratinocyte differentiation
in vitro. Here we asked whether oxysterols, another class of lipids formed de
novo in the epidermis and that activate liver X-activated receptor, regulate
keratinocyte differentiation. mRNA and protein levels of involucrin and
transglutaminase 1, markers of differentiation, increased 2- to 3-fold in normal
human keratinocytes incubated in the presence of 25- or 22R-hydroxycholesterol in
low calcium. In high calcium, which alone induces differentiation, mRNA levels
were further increased by oxysterols. Rates of cornified envelope formation, an
indicator of terminal differentiation, also increased 2-fold with oxysterol
treatment. In contrast, the rate of DNA synthesis was inhibited approximately 50%
by oxysterols. Transcriptional regulation was assessed in keratinocytes
transfected with either transglutaminase 1 or involucrin promoter-luciferase
constructs. 22R-hydroxycholesterol increased transglutaminase 1 and involucrin
promoter activity 2- to 3-fold. Either deletion of the -2452 bp to -1880 bp
region of the involucrin promoter, or mutation of the AP-1 site within this
region, abolished oxysterol responsiveness. Moreover, increased AP-1 DNA binding
was observed in oxysterol-treated keratinocytes by gel shift analyses. Finally,
we demonstrated the presence of liver X-activated receptor alpha and beta mRNAs,
and showed that oxysterols stimulate a liver X-activated receptor response
element transfected into keratinocytes. These data suggest that oxysterols induce
keratinocyte differentiation, in part through increased AP-1-dependent
transcription of the involucrin gene, an effect that may be mediated by liver X
activated receptor.
PMID- 10692117
TI - Stereoselective biosynthesis of hepoxilin B3 in human epidermis.
AB - We previously reported that normal human epidermis forms 12-oxo-eicosatetraenoic
acid and hepoxilin B3 as major eicosanoids and that hepoxilins and trioxilins are
dramatically elevated in psoriatic lesions. We also observed that normal
epidermis only synthesized one of the two possible 10-hydroxy- epimers of
hepoxilin B3, suggesting its enzymatic origin. This study investigated the
enzymatic pathways involved in the formation of hepoxilin B3 in human epidermis.
Human epidermal fragments or cell fractions were incubated with [14C]-arachidonic
acid or authentic 12(S)-hydroperoxyeicosatetraenoic acid. Products were analyzed
by high-performance liquid chromatography, gas chromatography-mass spectrometry
or a combination of both techniques. Esculetin and nordihydroguaiaretic acid
inhibited formation of hepoxilin B3, 12-oxo-eicosatetraenoic acid, trioxilins,
and 12-hydroxyeicosatetraenoic acid in a concentration-dependent manner. 12
Lipoxygenase activity was mainly located in the microsomal fraction (100,000 x g
pellet) and 12-hydroxyeicosatetraenoic acid, hepoxilin B3, and 12-oxo
eicosatetraenoic acid were formed. The hepoxilin B3-synthesizing activity was not
observed in subcellular fractions incubated with authentic 12(S)
hydroperoxyeicosatetraenoic acid, although it was located at least in the
microsomal fraction when incubated with arachidonic acid. Similar results were
obtained using preparations of recombinant platelet-type 12-lipoxygenase that
yielded 12-oxo-eicosatetraenoic acid and hepoxilin B3 in addition to 12
hydroxyeicosatetraenoic acid, when incubated with arachidonic acid but not when
incubated with 12-hydroperoxyeicosatetraenoic acid. Nevertheless, recombinant 12
lipoxygenase produced a lower ratio of 12-oxo-eicosatetraenoic acid and hepoxilin
B3-12-hydroxyeicosatetraenoic acid than epidermis. Our results support the
concept that 12-lipoxygenase catalyzes the formation of hepoxilin B3 and 12-oxo
eicosatetraenoic acid.
PMID- 10692118
TI - Langerhans cells migrate to local lymph nodes following cutaneous infection with
an arbovirus.
AB - Whereas there has been recent interest in interactions between dendritic cells
and pathogenic viruses, the role of dendritic cells in the initiation of
protective immunity to such organisms has not been elucidated. The aim of this
study was to examine whether a resident dendritic cell population in the skin,
Langerhans cells, respond to cutaneous viral infections which are effectively
cleared by the immune system. We therefore characterized the ability of
Langerhans cells to migrate to local draining lymph nodes following infection
with the arthropod-borne viruses, West Nile virus or Semliki Forest virus. The
data show that major histocompatibility complex class II+/NLDC145+/E-cadherin+
Langerhans cell numbers are increased in the draining lymph nodes of infected
mice and this increase is accompanied by a concomitant decrease in the Langerhans
cell density in the epidermis. Langerhans cell migration is associated with an
accumulation of leukocytes in the lymph node, which is one of the earliest events
in the initiation of an immune response. Both the migratory response and the
draining lymph node leukocyte accumulation were abrogated if ultraviolet
inactivated instead of live viruses were used, suggesting the activation and
subsequent migration of Langerhans cells requires a live, replicating antigen.
Our findings are likely to have wider implications for the development of
epidermally delivered vaccines and suggest that mobilization of dendritic cells
may be involved in the development of immune responses to arthropod-borne
viruses.
PMID- 10692119
TI - Formation of antigenic quinolone photoadducts on Langerhans cells initiates
photoallergy to systemically administered quinolone in mice.
AB - Quinolone antibacterial agents are well known to cause photoallergy as a side
effect. Murine photoallergy to fluoroquinolones is a T cell-mediated immune
response, evoked either by systemic fluoroquinolone and subsequent exposure of
skin to ultraviolet A light or by subcutaneous injection of fluoroquinolone
photomodified epidermal cells. In this photosensitivity, epidermal Langerhans
cells may be photomodified initially with the drug and thus present photohaptenic
moieties to sensitize and restimulate T cells. Although we have shown that
Langerhans cells photocoupled in vitro with fluoroquinolones are capable of
stimulating sensitized T cells, it remains unclear whether systemically given
fluoroquinolone photomodifies Langerhans cells upon ultraviolet A irradiation of
the skin and the Langerhans cells become photohapten-bearing, T cell-stimulatory
cells. In a murine model of fleroxacin photoallergy induced by intraperitoneal
injection of the drugs plus ultraviolet A irradiation of skin, we found that
Langerhans cells as well as keratinocytes are photoderivatized with fleroxacin as
demonstrated with a fluoroquinolone-specific monoclonal antibody. Langerhans-cell
enriched epidermal cells prepared from mice treated with fleroxacin and
ultraviolet A induced proliferation of sensitized T cells, indicating that
photomodified Langerhans cells are functional. There was an optimal range of
ultraviolet A dose to quantitatively and qualitatively form fleroxacin
photomodified Langerhans cells, as excess ultraviolet A rather reduced the
photoantigen-presenting capacity of Langerhans cells presumably because of drug
phototoxicity. Our study suggests that Langerhans cells serve as photoantigen
presenting cells in drug photoallergy.
PMID- 10692120
TI - Skin CD4+ T cells produce interferon-gamma in vitro in response to streptococcal
antigens in chronic plaque psoriasis.
AB - Recently, we have demonstrated that group A streptococcal antigen reactive T
cells are present in the skin lesions of chronic plaque psoriasis. To determine
the cytokine profile (interferon-gamma, interleukin-4 and interleukin-10) of
these T cells in response to streptococcal antigens, T cell lines were cultured
from untreated lesional skin of 13 patients with chronic plaque psoriasis and 12
patients with other inflammatory skin diseases. T cell lines were incubated with
or without a sonicated heat-killed mixture of group A streptococcal isolates for
18 h in the presence of a transport inhibitor, stained for surface CD4 or CD8 and
intracellular cytokine expression, and analyzed by flow cytometry. Psoriatic T
cell lines were grown from 10 of 13 patients and were predominately CD4+ (64%
85%) with 10%-32% CD8+ T cells. Variable numbers of CD4+ T cells produced
interferon-gamma (0.8%-35%, median 13.9) in eight of 10 T cell lines (p < 0.02).
In contrast, CD4+ T cells in five of 12 T cell lines obtained from disease
controls did not produce or produced minimal interferon-gamma in response to
group A streptococcal isolates; this was significantly different from the
psoriatic T cell lines (p < 0.05). Small numbers of interleukin-10 positive (0.8%
1.3%) and interleukin-4 positive (2.1%-2.5%) CD4+ T cells induced by group A
streptococcal isolates were also present in two out of five and three out of five
psoriatic T cell lines, respectively. This was significantly less in each case
than the numbers of CD4+/interferon-gamma+ T cells (p < 0.05). Cytokine-positive
CD8+ T cells were rarely observed. These findings demonstrate that a
subpopulation of CD4+ T cells in chronic plaque psoriasis skin lesions produces
interferon-gamma in response to streptococcal antigens and may be relevant to the
pathogenesis of psoriasis.
PMID- 10692121
TI - CD40 ligation alters the cell cycle of differentiating keratinocytes.
AB - CD40 is expressed in normal human keratinocytes, especially in the basal cell
layer. We have recently reported that CD40 ligation strongly inhibits
keratinocyte proliferation and induces their differentiation. In this study, the
CD40 pathway that prevents keratinocyte growth was investigated. We first
reported that interferon-gamma treatment potentiated the CD40-mediated inhibition
of keratinocyte proliferation. CD40-CD40 ligand interactions, in the presence or
absence of interferon-gamma, neither enhanced spontaneous keratinocyte apoptosis,
nor did it enhance apoptosis induced by various agents. More importantly, we
showed that CD40 signaling altered the keratinocyte cell cycle, as demonstrated
by a decreasing number of cells in the G1 and S phases and an accumulation in
G2/M phase of the cell cycle. Furthermore, western blot analysis of cell cycle
regulatory proteins, showed a decrease in cyclin A and E expression in CD40
activated keratinocytes. Collectively, these results indicate that CD40 ligation
inhibits keratinocyte renewal by a mechanism independent of cell apoptosis and
that modulation of the keratinocyte cell cycle is an additional outcome of CD40
signaling.
PMID- 10692122
TI - Psoriasis, its treatment, and cancer in a cohort of Finnish patients.
AB - This study was designed to estimate the relative cancer risk of patients with
moderate to severe psoriasis, with reference to different treatments. A cohort of
5687 hospitalized patients with psoriasis obtained from the Finnish Hospital
Discharge Register in 1973-84 was linked with the records of the Finnish Cancer
Registry. Standardized incidence ratios for cancer were calculated by dividing
the observed number of cases by the expected cases, which were based on the
national sex-specific and age-specific cancer incidence rates. By the end of
1995, 533 cancer cases were observed in the cohort. The overall cancer incidence
was increased (standardized incidence ratio 1.3, 95% confidence interval 1.2
1.4). The estimated relative risks were highest for Hodgkin's disease
(standardized incidence ratio 3.3, 95% confidence interval 1.4-6.4), squamous
cell skin carcinoma (standardized incidence ratio 3.2, 95% confidence interval
2.3-4.4), non-Hodgkin's lymphoma (standardized incidence ratio 2.2, 95%
confidence interval 1.4-3.4), and laryngeal cancer (standardized incidence ratio
2.9, 95% confidence interval 1.5-5.0). The role of prior oral antipsoriatic
medications or phototherapy on the development of these cancers was assessed in a
nested case-control study, for which 67 cases and 199 sex and age matched
controls were selected from the psoriasis cohort. The relative risks were
estimated using conditional logistic regression analysis. Oral 8-methoxy-psoralen
plus ultraviolet-A radiation therapy and the use of retinoids were associated
with an increased risk of squamous cell skin carcinoma (relative risk adjusted
for the other treatment variables 6.5, 95% confidence interval 1.4-31, and 7.4,
95% confidence interval 1.4-40, respectively), whereas none of the treatments
could be linked with the occurrence of non-Hodgkin's lymphoma.
PMID- 10692123
TI - Mutation report: a novel partial deletion of exons 2-10 of the STS gene in
recessive X-linked ichthyosis.
AB - X-linked ichthyosis is an inherited disease due to steroid sulfatase deficiency.
Onset is at birth or early after birth with dark, regular, and adherent scales of
skin. Approximately 85%-90% of X-linked ichthyosis patients have large deletions
of the STS gene and flanking sequences. Three patients have been identified with
partial deletions of the gene. Two deletions have been found at the 3' extreme
and the other one implicating exons 2-5. This study describes a novel partial
deletion of the STS gene in an X-linked ichthyosis patient. The subject was
classified through steroid sulfatase assay in leukocytes using 7-[3H]
dehydroepiandrosterone sulfate as a substrate. Exons 1, 2, 5, and 7-10, and 3'
flanking sequences DXS1131, DXS1133, DXS237, DXS1132, DXF22S1, and DXS278 of the
STS gene were analyzed through polymerase chain reaction. The DNA analysis showed
that exon 1 and 3' flanking sequences from DXS237 to DXS278 were present. In this
study we report the fourth partial deletion of the STS gene and the first
spanning exons 2-10 in X-linked ichthyosis patients.
PMID- 10692124
TI - Interleukin-1 and cutaneous inflammation: a crucial link between innate and
acquired immunity.
AB - As our primary interface with the environment, the skin is constantly subjected
to injury and invasion by pathogens. The fundamental force driving the evolution
of the immune system has been the need to protect the host against overwhelming
infection. The ability of T and B cells to recombine antigen receptor genes
during development provides an efficient, flexible, and powerful immune system
with nearly unlimited specificity for antigen. The capacity to expand subsets of
antigen-specific lymphocytes that become activated by environmental antigens
(memory response) is termed "acquired" immunity. Immunologic memory, although a
fundamental aspect of mammalian biology, is a relatively recent evolutionary
event that permits organisms to live for years to decades. "Innate" immunity,
mediated by genes that remain in germ line conformation and encode for proteins
that recognize conserved structural patterns on microorganisms, is a much more
ancient system of host defense. Defensins and other antimicrobial peptides,
complement and opsonins, and endocytic receptors are all considered components of
the innate immune system. None of these, however, are signal-transducing
receptors. Most recently, a large family of cell surface receptors that mediate
signaling through the NF-kappaB transcription factor has been identified. This
family of proteins shares striking homology with plant and Drosophila genes that
mediate innate immunity. In mammals, this family includes the type I interleukin
1 receptor, the interleukin-18 receptor, and a growing family of Toll-like
receptors, two of which were recently identified as signal-transducing receptors
for bacterial endotoxin. In this review, we discuss how interleukin-1 links the
innate and acquired immune systems to provide synergistic host defense activities
in skin.
PMID- 10692125
TI - A wavefront generator for complex pupil function synthesis and point spread
function engineering.
AB - We describe a simple method to produce an arbitrary complex optical field using a
ferroelectric liquid crystal spatial light modulator. The system is configured so
as to act as a pupil plane filter in a confocal microscope. The ability to tune
the complex pupil function permits the system to be used both to modify the
imaging performance by effectively engineering the point spread function as well
as to remove optical aberrations present in the optical system.
PMID- 10692126
TI - Image processing experiments for computer-based three-dimensional reconstruction
of neurones from electron micrographs from serial ultrathin sections.
AB - This study examined an image processing technique that uses a computer to
reconstruct a three-dimensional image of neurones from electron micrographs of
serial ultrathin sections. The major problems involved were: (a) a distortion of
features in electron micrographs; (b) a significant change of cross-section
features of neurones in electron micrographs of neighbouring sections; and (c)
disagreement between the electron microscopic section face and the coordinate
plane desired for the reconstruction. Electron micrographs of a retinal bipolar
cell stained with a biotinylated tracer were used. We corrected the distortion of
features by means of a warp, a widely used algorithm in morphing image
processing. The change of features between neighbouring electron micrographs was
minimized by filling the gaps with an interpolated image produced by a dissolve,
another algorithm in morphing, as well as the warp. The distortion of the three
dimensional reconstructed image made by piling up features was corrected by
making the image with a wire frame model. Furthermore, in order to estimate a
closed contour of features, an active contour model, Snakes, was applied to the
electron microscope features. Snakes successfully detected the contour of the
target feature, but in some electron microscope images broke into the target
feature.
PMID- 10692127
TI - ER-Tracker dye and BODIPY-brefeldin A differentiate the endoplasmic reticulum and
golgi bodies from the tubular-vacuole system in living hyphae of Pisolithus
tinctorius.
AB - Two fluorochromes, ER-TrackerTM Blue-White DPX dye and the fluorescent brefeldin
A (BFA) derivative, BODIPY-BFA, label the endoplasmic reticulum (ER) in hyphal
tips of Pisolithus tinctorius and allow its differentiation from the tubular
vacuole system at the light microscope level in living cells. The ER-Tracker dye
labels a reticulate network similar in distribution to ER as seen in electron
micrographs of freeze-substituted hyphae. BODIPY-BFA stains a thicker axially
aligned structure with an expanded region at the apex, which is similar to that
seen when hyphae are stained with ER-Tracker dye in the presence of unconjugated
BFA. This structure is considered to be ER modified by BFA, a view supported by
ultrastructural observations of the effect of BFA on the fungal ER. Both
fluorescent probes also stain punctate structures, which are most likely to be
Golgi bodies. Neither probe labels the tubular-vacuole system.
PMID- 10692128
TI - Unsupervised approval criteria for automated EBSP investigation of deformed
metals.
AB - Unsupervised approval criteria have been investigated for orientations gathered
from cold deformed samples (medium to high strain range) using the electron
backscattering pattern technique. For such samples, the dislocation cell-size is
on the order of the available step-size and pattern quality is generally low.
Approval criteria for assessing the validity of measured orientations under these
conditions were determined using, as a calibration, channel die cold deformed
single crystals of stable orientations. In all cases, approval criteria based on
an indexing confidence measure are found to be preferable. Different criteria are
suggested, depending on whether the orientation data are subsequently to be used
for texture analysis, or for a misorientation angle-based analysis. The latter is
illustrated by an investigation of the number of deformation generated high angle
boundaries introduced during a 90% cold reduction of a polycrystalline sample.
PMID- 10692129
TI - Grain size distribution analysis in polycrystalline LiF thin films by
mathematical morphology techniques on AFM images and X-ray diffraction data.
AB - The influence of the deposition temperature on the grain size of polycrystalline
lithium fluoride (LiF) thin films is studied using a mathematical morphology
method. On atomic force microscopy images of the LiF surface, the grain sizes and
shapes are determined by applying the watershed technique, together with a shape
factor algorithm. Also, the domain size of the film structure, determined by an X
ray diffraction data analysis, is compared and correlated with the mean grain
size as a function of the deposition temperature. In both cases a linear increase
with temperature and a very good agreement among the two structural parameters
(grain and domain size) was found.
PMID- 10692130
TI - Compact water-window transmission X-ray microscopy.
AB - We demonstrate sub-100 nm resolution water-window soft X-ray full-field
transmission microscopy with a compact system. The microscope operates at lambda
= 3.37 nm and is based on a 100 Hz table-top regenerative debris-free droplet
target laser-plasma X-ray source in combination with normal-incidence multilayer
condenser optics for sample illumination. High-spatial-resolution imaging is
performed with a 7.3% efficiency nickel zone plate and a 1024 x 1024 pixel CCD
detector. Images of dry test samples are recorded with exposure times of a few
minutes and show features smaller than 60 nm.
PMID- 10692131
TI - Analysis of spherical aberration of a water immersion objective: application to
specimens with refractive indices 1.33-1.40.
AB - The method of using immersion medium to correct spherical aberration for water
immersion objectives when the samples are not water is investigated. Spherical
aberration is measured by an interferometer converted from a confocal microscope
for samples with different refractive indices. When the proper refractive index
of the immersion medium and thickness of cover slip are selected, the measured
spherical aberration approaches zero. A theoretical model can be used for
prediction of the immersion medium to correct spherical aberration for various
samples. Using the thinnest available cover slip (100 microm), the zero spherical
aberration condition can be applied to samples with refractive index as high as
1.40. Confocal images in the condition of almost no spherical aberration are
included to demonstrate the improvement of axial resolution due to this
correction.
PMID- 10692132
TI - Retrospective shading correction based on entropy minimization.
AB - Shading is a prominent phenomenon in microscopy, manifesting itself via spurious
intensity variations not present in the original scene. The elimination of
shading effects is frequently necessary for subsequent image processing tasks,
especially if quantitative analysis is the final goal. While most of the shading
effects may be minimized by setting up the image acquisition conditions carefully
and capturing additional calibration images, object-dependent shading calls for
retrospective correction. In this paper a novel method for retrospective shading
correction is proposed. Firstly, the image formation process and the
corresponding shading effects are described by a linear image formation model,
which consists of an additive and a multiplicative parametric component.
Secondly, shading correction is performed by the inverse of the image formation
model, whose shading components are estimated retrospectively by minimizing the
entropy of the acquired images. A number of tests, performed on artificial and
real microscopical images, show that this approach is efficient for a variety of
differently structured images and as such may have applications in and beyond the
field of microscopical imaging.
PMID- 10692133
TI - Iterative thresholding for segmentation of cells from noisy images.
AB - We introduce an iterative thresholding algorithm for the segmentation of cells
from noisy cell images. The thresholding image, which is initially a constant,
changes iteratively with both the previous segmentation and image local activity.
Experimental results for both synthesized and real cell images are provided to
demonstrate the performance of the algorithm.
PMID- 10692134
TI - An investigation of segmentation methods and texture analysis applied to
tomographic images of human vertebral cancellous bone.
AB - The goal of this study is to determine architectural and textural parameters on
computed tomographic (CT) images, allowing us to explain the mechanical
compressive properties of bone. Although the resolution (150 microm) is of the
same order of magnitude as the trabecular thickness, this method enables the
possibility of perfecting an in vivo peripheral CT system with an acceptable
radiation dose for the patient. This study was performed on L2 vertebrae
cancellous bone specimens taken after necropsy in 22 subjects aged 47-95 years
(mean: 79 years). The segmentation process is a crucial point in the
determination of accurate architectural parameters. In this paper the use of two
different segmentation methods is investigated, based on an edge enhancement and
a region growing approach. The images are compared and the architectural
parameters extracted from the images segmented by both methods lead to a
quantitative evaluation. The parameters are found to be globally robust towards
the segmentation process, although some of them are much more sensitive to the
approach used. Highly significant correlations (P < 0.0005) have been obtained
between the two segmentation methods for all the parameters, with rho ranging
from 0.70 to 0.93. In order to improve the assessment of bone architecture,
texture analysis (run length method) was investigated. New features are obtained
from an image reduced to 16 grey-levels. Textural parameters in addition to
architectural parameters in a multivariate regression model increase
significantly (P = 0.01) the prediction of the maximum compressive strength
(variation of r2 from 0.75 up to 0.89).
PMID- 10692136
TI - New Developments for the Journal of Neuroendocrinology.
PMID- 10692135
TI - A simplified method of cleaning ixodid ticks for microscopy.
AB - The cleaning of ixodid ticks for microscopy can be achieved quickly and
efficiently using a combination of a wax solvent and an ultrasonic cleaner. The
technique involves minimum handling of specimens, produces no detectable damage
and is suitable for cleaning many specimens at the same time.
PMID- 10692137
TI - Environmental oestrogens: a hazard to human reproductive health?
PMID- 10692138
TI - Influence of neonatal rearing conditions on stress-induced adrenocorticotropin
responses and norepinepherine release in the hypothalamic paraventricular
nucleus.
AB - Postnatal rearing conditions influence the development of hypothalamic-pituitary
adrenal (HPA) responses to stress in the rat. Thus, postnatal handling dampens
HPA responsivity to stress, while prolonged periods of maternal separation have
the opposite effect. HPA responses to stress are initiated by the release of
corticotropin-releasing factor and/or arginine vasopressin from the neurones of
the paraventricular nucleus of the hypothalamus (PVNh). A major source of input
to the PVNh arises from brainstem noradrenergic neurones with signalling
occurring via alpha1 adrenoreceptors. We examined the noradrenergic response to
stress in the PVNh in adult animals exposed to daily periods of handling or
maternal separation over the first 2 weeks of life using microdialysis in
conscious animals. Maternal separation increased, while handling greatly
decreased and norepinepherine responses to restraint stress in the PVNh as
compared to non-handled controls; the same pattern was observed for plasma
adrenocorticotropic hormone (ACTH) responses to stress. Rearing condition did not
affect either alpha1 or alpha2 receptor levels in the PVNh. However, alpha2
receptor binding levels in the noradrenergic cell body regions of the locus
coeruleus and the n. tractus solitarius were significantly increased in handled
animals. These alpha2 receptors are principally located on noradrenergic neurones
(i.e. autoreceptors) and inhibit noradrenaline release at terminal sites. The
effects on alpha2 receptor levels could serve as a mechanism for the differences
in stress-induced noradrenaline levels in the PVNh and in HPA activity among
handled vs non-handled and maternal separation animals. Thus, early life events
may serve to influence the differentiation of noradrenergic neurones and thus
alter HPA responses stress in adulthood.
PMID- 10692139
TI - Effects of chronic stress on hypothalamic lnterleukin-1beta, interleukin-2, and
gonadotrophin-releasing hormone gene expression in ovariectomized rats.
AB - The influence of chronic stress on the expression of interleukin (IL)-1beta and
IL-2 mRNAs in ovariectomized rat brains, and the physiological consequences of
the expression of these cytokines on hypothalamic-pituitary-gonadal (HPG)
activity were investigated. Using polymerase chain reaction (PCR)-assisted
semiquantitative analysis, we demonstrated alterated expression of IL-1beta and
IL-2 mRNA during repeated cold stress; the expression of both IL-beta and IL-2
mRNA increased in the medial preoptic area and ventromedial hypothalamus, and
decreased in the lateral hypothalamic area. In the arcuate nucleus/median
eminence, IL-2 mRNA expression was dramatically decreased, in contrast to the
increase in IL-1beta mRNA expression. Concomitant analysis of GnRH mRNA
expression indicated significant suppression of GnRH synthesis in the chronic
phase, and a strong negative correlation with cytokine expression in the medial
preoptic area. Similar results were obtained in intact females exposed to this
stress. These results, together with previous pharmacological studies, suggest
that chronic stress may induce reproductive dysfunction through the effects of
stress-induced expression of endogenous cytokines.
PMID- 10692140
TI - Interleukin-3 and interleukin-6 stimulate bovine adrenal cortisol secretion
through different pathways.
AB - Several interleukins have been reported to play a major role in the regulation of
steroid secretion at all three levels of the hypothalamic-pituitary-adrenal axis.
The objective of this study was to investigate the effect of interleukin-3 (IL-3)
and interleukin-6 (IL-6) on cortisol secretion of bovine adrenocortical cells in
primary culture under serum-free conditions. Both IL-3 and IL-6 stimulated basal
cortisol secretion dose-dependently to a similar extent at a similar time course.
After incubation with IL-3 or IL-6 at concentrations of 100 microg/l, a maximum
4.1-fold increase of the cortisol secretion was reached after 12 h (P<0.01).
Coincubation of IL-3 and IL-6 (100 microg/l) revealed no significant synergism.
To elucidate a possible involvement of arachidonic acid metabolites in the signal
transduction, we coincubated IL-3 or IL-6 together with the cyclo-oxygenase
inhibitor indometacin or the lipoxygenase inhibitor nordihydroguaiaretic acid
(NDGA). Coincubation with indometacin completely abolished the stimulatory effect
of IL-6 but had no effect on IL-3 stimulated cortisol secretion. In contrast,
specific inhibition of the lipoxygenase system by nordihydroguaiaretic acid
blocked IL-3 stimulated steroidogenesis while the effect of IL-6 was not
affected. Neither IL-3 nor IL-6 altered cAMP levels significantly, whereas ACTH
significantly induced cAMP levels in parallel to its steroidogenic effect. In
conclusion, our data indicate that IL-3 and IL-6 stimulate the steroid secretion
of bovine adrenocortical cells to a similar extent and with a similar time
course. However, the effects of IL-3 and IL-6 are mediated through different,
cAMP-independent pathways. While the stimulatory effect of IL-3 seems to be
dependent on the lipoxygenase pathway, the effect of IL-6 on adrenocortical
cortisol secretion is mediated through the cyclo-oxygenase pathway.
PMID- 10692141
TI - Anatomically specific changes in the expression of somatostatin, growth hormone
releasing hormone and growth hormone receptor mRNA in diabetic rats.
AB - Growth hormone (GH) secretion is altered in poorly controlled diabetic animals.
However, modifications in the hypothalamic neuropeptides that control GH
secretion, somatostatin and GH-releasing hormone (GHRH), as well as changes in
the sensitivity of the hypothalamus and pituitary to the feedback effects of GH,
are less clear. We have used RNase protection assays and in-situ hybridization to
address whether the mRNA expression of GH, somatostatin and GHRH, as well as of
the GH receptor (GHR) in the hypothalamus and anterior pituitary, are altered in
streptozotocin-induced diabetic rats. After induction of diabetes, rats were
treated with insulin twice daily for 3 weeks to obtain either poorly controlled
(mean plasma glucose >300 mg/dl) or well-controlled diabetic rats. Although no
significant change in pituitary GH mRNA expression was found, the hypothalamic
expression of GHRH and somatostatin mRNA was reduced in poorly-controlled
diabetic rats and returned to control values with normalisation of plasma glucose
concentrations (P<0.0001 and P<0.002, respectively). Somatostatin mRNA expression
was reduced only in the central portion of the periventricular nucleus, with no
change being seen in the other areas of the periventricular nucleus or in the
arcuate, suprachiasmatic or paraventricular nuclei. A significant decline in GHRH
mRNA expression was observed in both the arcuate nucleus and ventromedial
hypothalamus. Anterior pituitary GHR mRNA expression was significantly reduced in
both well and poorly-controlled diabetic rats, while there was no change in the
hypothalamus. To examine whether the evolution time of the diabetes influences
these parameters, in a subsequent experiment, diabetic rats received no insulin
for 2 months. A significant decline in GHRH and somatostatin mRNA expression was
also observed in these rats. In addition, pituitary GH mRNA expression declined
significantly in long-term diabetic rats. These results demonstrate that: (1) the
expression of both GHRH and somatostatin declines specifically in anatomical
areas involved in anterior pituitary hormone control; (2) GHR mRNA expression is
decreased in the pituitary of diabetic rats, but not in the hypothalamus, and
does not return to control values with normalisation of mean blood glucose
concentrations; and (3) the evolution time of the diabetes is important for
detecting some changes, including the decrease in pituitary GH mRNA expression.
PMID- 10692142
TI - Regulation of GABAA receptor by protein tyrosine kinases in frog pituitary
melanotrophs.
AB - The effects of protein tyrosine kinase (PTK) and PTK inhibitors on the GABAA
receptor function were studied in cultured frog pituitary melanotrophs by using
the patch-clamp technique. Extracellular application of the PTK inhibitors
genistein (10-9 to 10-5 M) or lavendustin A (10-12 to 10-7 M) provoked a bell
shaped potentiation of the whole-cell current induced by GABA (3x10-6 M). In
contrast, at high concentrations, genistein (10-4 M) and lavendustin A (10-5 M)
reversibly reduced the GABA-evoked current. Daidzein and lavendustin B, the
inactive analogs of genistein and lavendustin A, respectively, did not modify the
current induced by GABA. In the inside-out configuration, bath application of the
recombinant PTK pp60c-src (75 U/ml) inhibited the GABA-activated chloride
current, and the inhibitory effect of pp60c-src was prevented by genistein (10-7
M). Immunoblotting revealed that genistein, at doses of 10-7 M or 10-4 M,
markedly inhibited tyrosine phosphorylation of the beta2/beta3 subunits of the
GABAA receptor. Extracellular application of the PKA activator Bt2cAMP (10-3 M),
the PKA/PKC inhibitor H7 (10-5 M) and the Cam KII inhibitor W7 (10-5 M)
reversibly diminished the whole-cell GABA-induced current. Internal application
of H7 and W7 (10-4 M) did not modify the dose-dependent effects of genistein.
Internal application of sodium orthovanadate (10-4 M), a protein tyrosine
phosphatase inhibitor, decreased the GABA-evoked current and markedly reduced the
potentiating effect of genistein. The present study provides the first evidence
that, in frog pituitary melanotrophs, the GABAA receptor is phosphorylated at
least on its beta2/beta3 subunits by an endogenous PTK. Our data also demonstrate
that tyrosine phosphorylation exerts an inhibitory effect on GABAA receptor
function.
PMID- 10692143
TI - The influence of gonadal steroids on pre-pro melanin-concentrating hormone mRNA
in female rats.
AB - Melanin-concentrating hormone (MCH) may have a regulatory role in the control of
luteinizing hormone (LH) release. We have investigated if gonadal steroids induce
changes in the expression of pre-pro MCH (ppMCH) that are associated with changes
in the pattern of LH release. Using quantitative in-situ hybridization
histochemistry we have determined the effect of administration of either
oestradiol benzoate (5 microg/rat) or oestradiol benzoate followed 44 or 48 h
later by progesterone (0.5 mg/rat) to ovariectomized rats on the expression of
ppMCH in the medial and lateral zona incerta and the lateral hypothalamus. The
prevalence of ppMCH transcripts in the intact female rat at 12.00 and 19.00 h on
proestrus and the first day of dioestrus was also examined. Oestrogen reduced the
intensity of hybridization signal for ppMCH mRNA and this was associated with
both a decrease in the number of cells in which the message was detected in the
medial zona incerta and a negative feedback effect on LH release in
ovariectomized rats. Progesterone administration to oestradiol benzoate-primed
rats did not alter the reduced expression in the medial zona incerta in spite of
its positive feedback effect on LH release. We suggest that progesterone may act
only on post-translational events. Expression in the MCH cell bodies of the
lateral zona incerta were not affected but there was a transient decrease 4 h
after progesterone treatment in the oestradiol benzoate-primed rats in expression
in the lateral hypothalamus. No changes in ppMCH mRNA were seen in intact animals
on proestrus or the first day of dioestrus indicating that gonadal steroids are
not important in the modulation of ppMCH gene expression during the oestrous
cycle. In other steroid-dependent physiological situations, however, oestrogen
may influence the expression of ppMCH in a subpopulation of cell bodies in the
medial zona incerta.
PMID- 10692144
TI - Potentiation effect of vasopressin on melatonin secretion as determined by trans
pineal microdialysis in the Rat.
AB - The mammalian pineal gland is known to receive a noradrenergic innervation
originating from the superior cervical ganglion which corresponds to the primary
regulatory input for melatonin synthesis. However, many peptidergic fibers
containing peptides such as vasopressin and oxytocin have also been found in the
rat pineal gland. The present study was performed to investigate the possible
role of vasopressin and oxytocin on melatonin secretion in vivo. Therefore, both
neuropeptides were delivered for 2 h through a trans-pineal microdialysis probe
directly into the gland at different times during the nocturnal phase of the
light:dark cycle. At the same time pineal dialysates were collected continuously.
Melatonin concentrations were measured by radioimmunoassay. Melatonin synthesis
potentiation was achieved when vasopressin was infused locally in the pineal,
during the onset of nocturnal melatonin secretion. In order to assess the
possible role of a physiological increase of endogenous circulating vasopressin
on pineal metabolism, melatonin synthesis was recorded in the same animals before
and after a prolonged dehydration period. Night time melatonin concentration was
increased after the water deprivation vs control conditions. Contrary to that,
oxytocin seems not to affect pineal metabolism in the rat since no significant
change was observed on melatonin secretion in response to a local oxytocin
infusion. These results show that vasopressin can modulate melatonin synthesis in
the rat pineal whereas no effect was obtained with oxytocin, at least under the
present experimental conditions.
PMID- 10692145
TI - Metabolic influences on circadian rhythmicity in Siberian and Syrian hamsters
exposed to long photoperiods.
AB - Calorie restriction and other situations of reduced glucose availability in
rodents alter the entraining effects of light on the circadian pacemaker located
in the suprachiasmatic nuclei. Siberian and Syrian hamsters are photoperiodic
species that are sexually active when exposed to long summer-like photoperiods,
while both species show opposite changes in body mass when transferred from long
to short or short to long days. Because metabolic cues may fine tune the
photoperiodic responses via the suprachiasmatic nuclei, we tested whether timed
calorie restriction can alter the photic synchronization of the light-entrainable
pacemaker in these two hamster species exposed to long photoperiods. Siberian and
Syrian hamsters were exposed to 16 h:8 h light:dark cycles and received daily
hypocaloric (75% of daily food intake) or normocaloric diet (100% of daily food
intake) 4 h after light onset. Four weeks later, hamsters were transferred to
constant darkness and fed ad libitum. The onset of the nocturnal pattern of
locomotor activity was phase advanced by 1.5 h in calorie-restricted Siberian
hamsters, but not in Syrian hamsters. The lack of phase change in calorie
restricted Syrian hamsters was also observed in individuals exposed to 14 h:10 h
dim light:dark cycles and fed with lower hypocaloric food (i.e. 60% of daily food
intake) 2 h after light onset. Moreover, in hamsters housed in constant darkness
and fed ad lib., light-induced phase shifts of the locomotor activity in Siberian
hamsters, but not in Syrian hamsters were significantly reduced when glucose
utilization was blocked by pretreatment with 500 mg/kg i.p. 2-deoxy-D-glucose.
Taken together, these results show that the photic synchronization of the light
entrainable pacemaker can be modulated by metabolic cues in Siberian hamsters,
but not in Syrian hamsters maintained on long days.
PMID- 10692146
TI - Differential effects of placental restriction on IGF-II, ACTH receptor and
steroidogenic enzyme mRNA levels in the foetal sheep adrenal.
AB - We have investigated the effects of restriction of placental growth on foetal
adrenal growth and adrenal expression of mRNAs for Insulin-like Growth Factor II
(IGF-II), the IGF binding protein IGFBP-2, Steroidogenic Factor 1 (SF-1) and
adrenocorticotrophic hormone (ACTH) receptor (ACTH-R) and the steroidogenic
cytochrome P-450 enzymes: cholesterol side chain cleavage (CYP11A1), 17alpha
hydroxylase (CYP17) and 21-hydroxylase (CYP21A1); and 3beta-hydroxysteroid
dehydrogenase/Delta5Delta4 isomerase (3betaHSD). Endometrial caruncles were
removed from non-pregnant ewes before mating (placental restriction group; PR).
The total adrenal: foetal weight ratio was higher in PR (n=6 foetuses) than in
control foetuses (n=6 foetuses). There was no difference in plasma ACTH
concentrations between the PR and control foetuses between 130 and 140 days
gestation. Adrenal IGF-II mRNA levels were lower (P<0.05) in the PR group,
however, adrenal IGFBP-2 mRNA levels were not different between the PR and
control groups. Adrenal ACTH-R mRNA levels were also lower whilst CYP11A1 mRNA
levels were increased (P<0.005) in the PR group. We conclude that foetal adrenal
growth and steroidogenesis are stimulated as a consequence of foetal growth
restriction and that factors other than ACTH are important in foetal adrenal
activation during chronic, sustained hypoxaemia.
PMID- 10692147
TI - Thyroid hormone acts centrally to programme photostimulated male american tree
sparrows (Spizella arborea) for vernal and autumnal components of seasonality.
AB - Thyroid hormone and long days interact to programme American tree sparrows
(Spizella arborea) for seasonality (i.e. thyroid hormone-dependent photoperiodic
gonadal growth, photorefractoriness, and postnuptial moult). This study explored
in radiothyroidectomized (THX) males given thyroid hormone replacement therapy
whether thyroid hormone acts within the brain and, additionally, the identity of
the putative tissue-active thyroid hormone. The minimum dose (30 ng) of L
thyroxine (T4) that restored all components of seasonality when given i.c.v.
daily during the first 21 days of photostimulation restored no component of
seasonality when given s.c. The same dose of L-triiodothyronine (T3) also was
ineffective when administered s.c., but restored photoperiodic testicular growth
(though neither photorefractoriness nor postnuptial moult) when admiministered
i.c.v. Three of seven birds given a 10-fold lower dose of T4 (3 ng) exhibited
thyroid hormone-dependent photoperiodic testicular growth, albeit damped. The
other four birds given 3 ng T4 and all birds given 3 ng T3 responded like THX
controls, exhibiting only slight thyroid hormone-independent photoperiodic
testicular growth. The highest dose (300 ng) of T3 restored all components of
seasonality only when administered i.c.v. daily during the first 49 days of
photostimulation. This demonstration in American tree sparrows is the first in
any species that the thyroid-dependent transition from the breeding season to the
non-breeding season can be effected by T3. The same dose of reverse T3
administered daily over the same 49 days restored photoperiodic testicular growth
in only half of 10 subjects and photorefractoriness and moult in none.
Collectively, the data support the hypothesis that thyroid hormone acts centrally
to programme photostimulated male American tree sparrows for all components of
seasonality. The most parsimonious interpretation of the data, including the
threshold-like effect of 3 ng T4, favours T4 as the tissue-active thyroid hormone
for vernal as well as autumnal events, but does not entirely exclude T3.
PMID- 10692148
TI - Families of transmembrane sugar transport proteins.
AB - We describe here 20 families of secondary (pmf-driven) carriers which, in
addition to nine families within the ATP-dependent ABC superfamily, and seven
families of Gram-negative bacterial outer membrane porins, largely account for
the stereospecific transport of sugars and their derivatives into and out of all
living cells on earth. Family characteristics as well as struc-tural and
functional properties of the family constituents are described. By reference to
our website (http://www-biology.ucsd.edu/ approximately msaier/transport/),
phylogenetic relationships, detailed substrate specificity information and both
primary and secondary references are also available. This review provides a
comprehensive guide to the diversity of carriers that mediate the transport of
sugar-containing molecules across cell and organellar membranes.
PMID- 10692149
TI - Outer-membrane phospholipase A: known structure, unknown biological function.
AB - Outer-membrane phospholipase A (OMPLA) is one of the few enzymes present in the
outer membrane of Gram-negative bacteria. The enzymatic activity of OMPLA is
strictly regulated to prevent uncontrolled breakdown of the surrounding
phospholipids. The activity of OMPLA can be induced by membrane perturbation and
concurs with dimerization of the enzyme. The recently elucidated crystal
structures of the inactive, monomeric and an inhibited dimeric form of the enzyme
provide detailed structural insight into the functional properties of the enzyme.
OMPLA is a serine hydrolase with a unique Asn-156-His-142-Ser-144 catalytic
triad. Only in the dimeric state, complete substrate binding pockets and
functional oxyanion holes are formed. A model is proposed for the activation of
OMPLA in which membrane perturbation causes the formation of non-bilayer
structures, resulting in the presentation of phospholipids to the active site of
OMPLA and leading to the formation of the active dimeric species. Possible roles
for OMPLA in maintaining the cell envelope integrity and in pathogenicity are
discussed.
PMID- 10692150
TI - Lipopolysaccharide core phosphates are required for viability and intrinsic drug
resistance in Pseudomonas aeruginosa.
AB - Pseudomonas aeruginosa is an opportunistic pathogen that is notorious for its
intrinsic drug resistance. We have used chemical and genetic techniques to
characterize three putative kinase genes that are involved in the addition of
phosphate to the inner core region of P. aeruginosa lipopolysaccharide. The first
gene is a waaP homologue, whereas the other two (wapP and wapQ) are unique to P.
aeruginosa. Repeated attempts using a variety of membrane-stabilizing conditions
to generate waaP:Gm (Gm, gentamicin) or wapP:Gm mutants were unsuccessful. We
were able to generate a chromosomal waaP mutant that had a wild-type copy of
either waaPPa or waaPEc in trans, but were unable to cure this plasmid-borne copy
of the gene. These results are consistent with the fact that P. aeruginosa
mutants lacking inner core heptose (Hep) or phosphate have never been isolated
and demonstrate the requirement of Hep-linked phosphate for P. aeruginosa
viability. A wapQ:Gm mutant was isolated and it had an unaltered minimum
inhibitory concentration (MIC) for novobiocin and only a small decrease in the
MIC for sodium dodecyl sulphate (SDS), suggesting that the loss of a phosphate
group transferred by WapQ may only be having a small impact on outer-membrane
permeability. Nuclear magnetic resonance and methylation linkage analysis showed
that WaaPPa could add one phosphate to O4 of HepI in a Salmonella typhimurium
waaP mutant. The expression of WaaPPa increased the outer-membrane integrity of
these complemented mutants, as evidenced by 35-fold and 75-fold increases in the
MIC for novobiocin and SDS respectively. The S. typhimurium waaP mutant
transformed with both waaP and wapP had over 250-fold and 1000-fold increases,
respectively, in these MICs. The inner core phosphates of P. aeruginosa appear to
be playing a key role in the intrinsic drug resistance of this bacterium.
PMID- 10692151
TI - DNA methylation-dependent regulation of pef expression in Salmonella typhimurium.
AB - Plasmid-encoded fimbriae (Pef) expressed by Salmonella typhimurium mediate
adhesion to mouse intestinal epithelium. The pef operon shares features with the
Escherichia coli pyelonephritis-associated pilus (pap) operon, which is under
methylation-dependent transcriptional regulation. These features include
conserved DNA GATC box sites in the upstream regulatory region as well as
homologues of the PapI and PapB regulatory proteins. Unlike Pap fimbriae, which
are expressed in a variety of laboratory media, Pef fimbriae were expressed only
in acidic, rich broth under standing culture conditions. Analysis of S.
typhimurium grown under these conditions indicated that Pef production was
regulated by a phase variation mechanism, in which the bacterial population was
skewed between fimbrial expression (phase ON) and non-expression (phase OFF)
states. Leucine-responsive regulatory protein (Lrp) and DNA adenine methylase
(Dam) were required for pef transcription. In contrast, the histone-like protein
(H-NS) and the stationary-phase sigma factor (RpoS) repressed pef transcription.
Methylation of the pef GATC II site appeared to be required for pef fimbrial
expression based on analysis of a GCTC II mutant that did not express Pef
fimbriae. Analysis of the DNA methylation states of pef GATC sites indicated
that, under acidic growth conditions, which induced Pef production, most GATC I
sites were non-methylated, whereas GATC II and GATC X were predominantly
methylated. The methylation protection at GATC I and GATC II was dependent upon
Lrp and was modulated by PefI. Together, these results indicate that Pef
production is regulated by DNA methylation, which is the first example of
methylation-dependent gene regulation outside of E. coli.
PMID- 10692152
TI - Phosphorylation of the flagellar regulatory protein FlrC is necessary for Vibrio
cholerae motility and enhanced colonization.
AB - The human pathogen Vibrio cholerae specifically expresses virulence factors
within the host, including cholera toxin (CT) and the toxin co-regulated pilus
(TCP), which allow it to colonize the intestine and cause disease. V. cholerae is
a highly motile organism by virtue of a polar flagellum, and motility has been
inferred to be an important aspect of virulence, yet the exact role of motility
in pathogenesis has remained undefined. The two-component regulatory system
FlrB/FlrC is required for polar flagellar synthesis; FlrC is a sigma54-dependent
transcriptional activator. We demonstrate that the transcriptional activity of
FlrC affects both motility and colonization of V. cholerae. In a purified in
vitro reaction, FlrB transfers phosphate to the wild-type FlrC protein, but not
to a mutant form in which the aspartate residue at amino acid position 54 has
been changed to alanine (D54A), consistent with this being the site of
phosphorylation of FlrC. The wild-type FlrC protein, but not the D54A protein,
activates sigma54-dependent transcription in a heterologous system, demonstrating
that phospho-FlrC is the transcriptionally active form. A V. cholerae strain
containing a chromosomal flrCD54A allele did not synthesize a flagellum and had
no detectable levels of transcription of the critical sigma54-dependent flagellin
gene flaA. The V. cholerae flrCD54A mutant strain was also defective in its
ability to colonize the infant mouse small intestine, approximately 50-fold worse
than an isogenic wild-type strain. Another mutation of FlrC (methionine 114 to
isoleucine; M114I) confers constitutive transcriptional activity in the absence
of phosphorylation, but a V. cholerae flrCM114I mutant strain, although
flagellated and motile, was also defective in its ability to colonize. The
strains carrying D54A or M114I mutant FlrC proteins expressed normal levels of CT
and TCP under in vitro inducing conditions. Our results show that FlrC 'locked'
into either an inactive (D54A) or an active (M114I) state results in colonization
defects, thereby demonstrating a requirement for modulation of FlrC activity
during V. cholerae pathogenesis. Thus, the sigma54-dependent transcriptional
activity of the flagellar regulatory protein FlrC contributes not only to
motility, but also to colonization of V. cholerae.
PMID- 10692153
TI - Two roles for integration host factor at an enhancer-dependent nifA promoter.
AB - Control of transcription in prokaryotes often involves direct contact of
regulatory proteins with RNA polymerase. For the sigma54 RNA polymerase,
regulatory proteins bound to distally located enhancers engage the polymerase via
DNA looping. The sigma54-dependent nifA promoter of Herbaspirillum seropedicae
(Hs) is activated under nitrogen-limiting growth conditions. Potential enhancers
for the nitrogen control activators NTRC and NIFA and binding sites for
integration host factor (IHF) and sigma54-holoenzyme were identified. DNA
footprinting experiments showed that these sites functioned for protein binding.
Their involvement in the promoter regulation was explored. In vitro, activation
of the Hs nifA promoter by NTRC is stimulated by the DNA bending protein IHF. In
marked contrast, activation by NIFA is greatly reduced by IHF, thus diminishing
potentially destabilizing autoactivation of the nifA promoter by NIFA.
Additionally, high levels of NIFA appear to limit NTRC-dependent activation. This
inhibition is IHF dependent. Therefore, IHF acts positively and negatively at the
nifA promoter to restrict transcription activation to NTRC and one signal
transduction pathway.
PMID- 10692154
TI - A new mechanism for the control of a prokaryotic transcriptional regulator:
antagonistic binding of positive and negative effectors.
AB - MalT, the transcriptional activator of the Escherichia coli maltose regulon, self
associates, binds promoter DNA and activates initiation of transcription only in
the presence of ATP and maltotriose, the inducer. In vivo studies have revealed
that MalT action is negatively controlled by the MalY protein. Using a
biochemical approach, we analyse here the mechanism whereby MalY represses MalT
activity. We show that MalY inhibits transcription activation by MalT in a
purified transcription system. In vitro, a constitutive MalT variant (which is
partially active in the absence of maltotriose) is less sensitive than wild-type
MalT to repression by MalY, as observed in vivo. We demonstrate that MalY forms a
complex with MalT only in the absence of maltotriose and that, conversely, MalY
inhibits maltotriose binding by MalT. Together, these results establish that MalY
acts directly upon MalT without the help of any factor, and that MalY is a
negative effector of MalT competing with the inducer for MalT binding.
PMID- 10692155
TI - In vivo and in vitro studies of transmembrane beta-strand deletion, insertion or
substitution mutants of the Escherichia coli K-12 maltoporin.
AB - LamB of Escherichia coli K12, also called maltoporin, is an outer membrane
protein, which specifically facilitates the diffusion of maltose and maltodextrin
through the bacterial outer membrane. Each monomer is composed of an 18-stranded
antiparallel beta-barrel. In the present work, on the basis of the known X-ray
structure of LamB, the effects of modifications of the beta-barrel domain of
maltoporin were studied in vivo and in vitro. We show that: (i) the substitution
of the pair of strands beta13-beta14 of the E. coli maltoporin with the
corresponding pair of strands from the functionally related maltoporin of
Salmonella typhimurium yielded a protein active in vivo and in vitro; and (ii)
the removal of one pair of beta-strands (deletion beta13-beta14) from the E. coli
maltoporin, or its replacement by a pair of strands from the general porin OmpF
of E. coli, leads to recombinant proteins that lost in vivo maltoporin activities
but still kept channel formation and carbohydrate binding in vitro. We also
inserted into deletion beta13-beta14 the portion of the E. coli LamB protein
comprising strands beta13 to beta16. This resulted in a protein expected to have
20 beta-strands and which completely lost all LamB-specific activities in vivo
and in vitro.
PMID- 10692156
TI - A positive feedback mechanism controls expression of AlkS, the transcriptional
regulator of the Pseudomonas oleovorans alkane degradation pathway.
AB - The AlkS regulator, encoded by the alkS gene of the Pseudomonas oleovorans OCT
plasmid, activates the expression of a set of enzymes that allow assimilation of
alkanes. We show that the AlkS protein regulates, both negatively and positively,
the expression of its own gene. In the absence of alkanes, alkS is expressed from
promoter PalkS1, which is recognized by sigmaS-RNA polymerase, and whose activity
is very low in the exponential phase of growth and considerably higher in
stationary phase. AlkS was found to downregulate this promoter, limiting
expression of alkS in stationary phase when alkanes were absent. In the presence
of alkanes, AlkS repressed PalkS1 more strongly and simultaneously activated a
second promoter for alkS, named PalkS2, located 38 bp downstream from PalkS1.
Activation of PalkS2 allowed efficient transcription of alkS when alkanes were
present. Transcription from PalkS2 was modulated by catabolite repression when
cells were provided with a preferred carbon source. We propose that the
expression of alkS is regulated by a positive feedback mechanism, which leads to
a rapid increase in alkS transcription when alkanes are present. This mechanism
should allow a rapid induction of the pathway, as well as a fast switch-off when
alkanes are depleted. An improved model for the regulation of the pathway is
proposed.
PMID- 10692157
TI - CtsR controls class III heat shock gene expression in the human pathogen Listeria
monocytogenes.
AB - Stress proteins play an important role in virulence, yet little is known about
the regulation of stress response in pathogens. In the facultative intracellular
pathogen Listeria monocytogenes, the Clp ATPases, including ClpC, ClpP and ClpE,
are required for stress survival and intracellular growth. The first gene of the
clpC operon of L. monocytogenes encodes a homologue of the Bacillus subtilis CtsR
repressor of stress response genes. An L. monocytogenes ctsR-deleted mutant
displayed enhanced survival under stress conditions (growth in the presence of 2%
NaCl or at 42 degrees C), but its level of virulence in the mouse was not
affected. The virulence of a wild-type strain constitutively expressing CtsR is
significantly attenuated, presumably because of repression of the stress
response. Regulation of the L. monocytogenes clpC, clpP and clpE genes was
investigated using transcriptional fusions in B. subtilis as a host. The L.
monocytogenes ctsR gene was placed under the control of an inducible promoter,
and regulation by CtsR and heat shock was demonstrated in vivo in B. subtilis.
The purified CtsR protein of L. monocytogenes binds specifically to the clpC,
clpP and clpE regulatory regions, and the extent of the CtsR binding sites was
defined by DNase I footprinting. Our results demonstrate that this human pathogen
possesses a CtsR regulon controlling class III heat shock genes, strikingly
similar to that of the saprophyte B. subtilis. This is the first description of a
stress response regulatory gene in a pathogen.
PMID- 10692158
TI - The asgE locus is required for cell-cell signalling during Myxococcus xanthus
development.
AB - In response to starvation, Myxococcus xanthus undergoes a multicellular
developmental process that produces a dome-shaped fruiting body structure filled
with differentiated cells called myxospores. Two insertion mutants that block the
final stages of fruiting body morphogenesis and reduce sporulation efficiency
were isolated and characterized. DNA sequence analysis revealed that the
chromosomal insertions are located in open reading frames ORF2 and asgE, which
are separated by 68 bp. The sporulation defect of cells carrying the asgE
insertion can be rescued phenotypically when co-developed with wild-type cells,
whereas the sporulation efficiency of cells carrying the ORF2 insertion was not
improved when mixed with wild-type cells. Thus, the asgE insertion mutant appears
to belong to a class of developmental mutants that are unable to produce cell
cell signals required for M. xanthus development, but they retain the ability to
respond to them when they are provided by wild-type cells. Several lines of
evidence indicate that asgE cells fail to produce normal levels of A-factor, a
cell density signal. A-factor consists of a mixture of heat-stable amino acids
and peptides, and at least two heat-labile extracellular proteases. The asgE
mutant yielded about 10-fold less heat-labile A-factor and about twofold less
heat-stable A-factor than wild-type cells, suggesting that the primary defect of
asgE cells is in the production or release of heat-labile A-factor.
PMID- 10692159
TI - Interactions between Pho85 cyclin-dependent kinase complexes and the Swi5
transcription factor in budding yeast.
AB - Pho85 is a cyclin-dependent protein kinase (Cdk) in budding yeast with roles in
cell metabolism and cell cycle progression. Activation of Pho85 occurs through
association with Pho85 cyclins (Pcls), of which 10 are known. When complexed with
the G1 cyclins, Pcl1 and Pcl2, Pho85 is required for cell cycle progression in
the absence of the Cdc28-dependent cyclins, Cln1 and Cln2. To identify potential
targets of Pcl2-Pho85, we performed a two-hybrid screen using the Pcl2 cyclin as
bait and recovered the transcription factor Swi5 as a Pcl2-interacting protein.
We performed both biochemical and genetic tests to discover the biological
significance of the interaction between Pcl2 and Swi5 seen in the two-hybrid
assay. We found that Swi5 interacts in vitro with Pho85 cyclins and is
phosphorylated in vitro by the Pho80-Pho85 kinase. We discovered that a subset of
genes that are controlled by Swi5 and a homologous transcription factor, Ace2,
was misregulated in a pho85 deletion strain; expression of the ASH1 and CTS1
genes was reduced in an ace2 deletion strain, whereas expression of both genes
was increased in an ace2Delta pho85Delta double mutant. We also found that
overexpression of SWI5 caused cell lethality in a pho85 deletion strain. Our
results are consistent with misregulation of Swi5 activity in vivo in the absence
of Pho85 and implicate Swi5 as a potential substrate of Pho85 cyclin-dependent
kinase complexes.
PMID- 10692160
TI - IHF redistributes bound initiator protein, DnaA, on supercoiled oriC of
Escherichia coli.
AB - In Escherichia coli, initiation of chromosome replication requires that DnaA
binds to R boxes (9-mer repeats) in oriC, the unique chromosomal replication
origin. At the time of initiation, integration host factor (IHF) also binds to a
specific site in oriC. IHF stimulates open complex formation by DnaA on
supercoiled oriC in cell-free replication systems, but it is unclear whether this
stimulation involves specific changes in the oriC nucleoprotein complex. Using
dimethylsulphate (DMS) footprinting on supercoiled oriC plasmids, we observed
that IHF redistributed prebound DnaA, stimulating binding to sites R2, R3 and
R5(M), as well as to three previously unidentified non-R sites with consensus
sequence (A/T)G(G/C) (A/T)N(G/C)G(A/T)(A/T)(T/C)A. Redistribution was dependent
on IHF binding to its cognate site and also required a functional R4 box. By
reducing the DnaA level required to separate DNA strands and trigger initiation
of DNA replication at each origin, IHF eliminates competition between strong and
weak sites for free DnaA and enhances the precision of initiation synchrony
during the cell cycle.
PMID- 10692161
TI - Involvement of differential efficiency of transcription by esigmas and esigma70
RNA polymerase holoenzymes in growth phase regulation of the Escherichia coli
osmE promoter.
AB - Transcription of the gene osmE of Escherichia coli is inducible by elevated
osmotic pressure and during the decelerating phase of growth. osmE expression is
directed by a single promoter, osmEp. Decelerating phase induction of osmEp is
dependent on the sigmas (RpoS) factor, whereas its osmotic induction is
independent of sigmas. Purified Esigmas and Esigma70 were both able to transcribe
osmEp in vitro on supercoiled templates. In the presence of rpoD800, a mutation
resulting in a thermosensitive sigma70 factor, a shift to non-permissive
temperature abolished induction of osmEp after an osmotic shock during
exponential phase, but did not affect the decelerating phase induction. Point
mutations affecting osmEp activity were isolated. Down-promoter mutations
decreased transcription in both the presence and the absence of sigmas,
indicating that the two forms of RNA polymerase holoenzyme recognize very similar
sequence determinants on the osmE promoter. Three up-promoter mutations brought
osmEp closer to the consensus of Esigma70-dependent promoters. The two variant
promoters exhibiting the highest efficiency became essentially independent of
sigmas in vivo. Our data suggest that Esigmas transcribes wild-type osmEp with a
higher efficiency than Esigma70. A model in which an intrinsic differential
recognition contributes to growth phase-dependent regulation is proposed.
Generalization of this model to other sigmas-dependent promoters is discussed.
PMID- 10692162
TI - Identification of novel VirR/VirS-regulated genes in Clostridium perfringens.
AB - Novel genes that are regulated in Clostridium perfringens by the two-component
regulatory system, VirR/VirS, were identified using a differential display
method. A plasmid library was constructed from C. perfringens chromosomal DNA,
and the plasmids were hybridized with cDNA probes prepared from total RNA of wild
type strain 13 and its virR mutant derivative TS133. Three clones were identified
that carry newly identified VirR/VirS-regulated genes, two of which were
positively regulated and one of which was negatively regulated. Genes located on
the identified clones were deduced by nucleotide sequencing, and the target genes
of the VirR/VirS system were identified with a set of Northern hybridizations. A
4.9 kb mRNA transcribing the metB (cystathionine gamma-synthase), cysK (cysteine
synthase) and ygaG (hypothetical protein) genes was negatively regulated, whereas
1.6 and 6.0 kb transcripts encoding ptp (protein tyrosine phosphatase) and cpd
(2',3'-cyclic nucleotide 2'-phosphodiesterase) respectively, were shown to be
positively regulated by the VirR/VirS system. The other gene, hyp7, whose
transcript was positively regulated by the VirR/VirS system, was shown to
activate the transcription of the colA (kappa-toxin) and plc (alpha-toxin) genes,
but not the pfoA (theta-toxin) gene in C. perfringens. These results suggested
that the global regulatory system VirR/VirS could regulate various genes, other
than toxin genes, both positively and negatively and that the hyp7 gene might
encode a novel regulatory factor for toxin production in C. perfringens.
PMID- 10692163
TI - Evolutionary conservation of prion-forming abilities of the yeast Sup35 protein.
AB - Saccharomyces cerevisiae prion [PSI ] is a self-propagating isoform of the
eukaryotic release factor eRF3 (Sup35p). Sup35p consists of the evolutionary
conserved release factor domain (Sup35C) and two evolutionary variable regions -
Sup35N, which serves as a prion-forming domain in S. cerevisiae, and Sup35M.
Here, we demonstrate that the prion form of Sup35p is not observed among
industrial and natural strains of yeast. Moreover, the prion ([PSI + ]) state of
the endogenous S. cerevisiae Sup35p cannot be transmitted to the next generations
via heterologous Sup35p or Sup35NM, originating from the distantly related yeast
species Pichia methanolica. This suggests the existence of a 'species barrier' in
yeast prion conversion. However, the chimeric Sup35p, containing the Sup35NM
region of Pichia, can be turned into a prion in S. cerevisiae by overproduction
of the identical Pichia Sup35NM. Therefore, the prion-forming potential of
Sup35NM is conserved in evolution. In the heterologous system, overproduction of
Pichia Sup35p or Sup35NM induced formation of the prion form of S. cerevisiae
Sup35p, albeit less efficiently than overproduction of the endogenous Sup35p.
This implies that prion induction by protein overproduction does not require
strict correspondence of the 'inducer' and 'inducee' sequences, and can overcome
the 'species barrier'.
PMID- 10692164
TI - Phase variation of Ag43 in Escherichia coli: Dam-dependent methylation abrogates
OxyR binding and OxyR-mediated repression of transcription.
AB - It has been shown previously that phase variation of the outer membrane protein
Antigen43 (Ag43) of Escherichia coli requires the DNA-methylating enzyme
deoxyadenosine methyltransferase (Dam) and the global regulator OxyR. In this
study, we analysed the regulation of the Ag43 encoding gene (agn) using isolates
containing a fusion of the agn regulatory region to the reporter gene lacZ. Our
results indicate that phase variation of Ag43 is regulated at the level of
transcription. Repression of agn'-lacZ transcription required OxyR, whereas
activation required Dam. The regulatory region of agn contains three GATC
sequences, which are target sites for Dam-dependent methylation. In vivo, the
methylation state of these GATC sequences correlated with the transcription state
of agn'-lacZ. These GATC sequences were not protected from Dam-dependent
methylation in an oxyR background, suggesting that OxyR binding results in Dam
dependent methylation protection in OFF cells. In vitro, both oxidized OxyR and
OxyR(C199S), which is locked in the reduced conformation, bound to the agn
regulatory region, but methylation of the three GATC sequences abrogated this
binding. In vivo, OxyR(C199S) was sufficient to repress Ag43 transcription. Our
data support a model in which OxyR-mediated repression of transcription is
alleviated by methylation of three GATC sequences in its binding site. In
addition, we show that, in an oxyR background, Dam was still required for full
activation, suggesting that the model concerning the role of Dam in agn
regulation is incomplete. These results show that Dam-dependent phase variation
in E. coli is not limited to the previously identified regulatory system of the
family of pap-like fimbrial operons.
PMID- 10692165
TI - Identification of a unique domain essential for Escherichia coli DNA
topoisomerase III-catalysed decatenation of replication intermediates.
AB - A 17-amino-acid residue domain has been identified in Escherichia coli DNA
topoisomerase III (Topo III) that is essential for Topo III-mediated resolution
of DNA replication intermediates in vitro. Deletion of this domain reduced Topo
III-catalysed resolution of DNA replication intermediates and decatenation of
multiply linked plasmid DNA dimers by four orders of magnitude, whereas reducing
Topo III-catalysed relaxation of negatively supercoiled DNA substrates only 20
fold. The presence of this domain has been detected in multiple plasmid-encoded
topoisomerases, raising the possibility that these enzymes may also be
decatenases.
PMID- 10692166
TI - Delineation of pilin domains required for bacterial association into
microcolonies and intestinal colonization by Vibrio cholerae.
AB - The toxin-co-regulated pilus (TCP), a type 4 pilus that is expressed by epidemic
strains of Vibrio cholerae O1 and O139, is required for colonization of the human
intestine. The TCP structure is assembled as a polymer of repeating subunits of
TcpA pilin that form long fibres, which laterally associate into bundles.
Previous passive immunization studies have suggested that the C-terminal region
of TcpA is exposed on the surface of the pilus fibre and has a critical role in
mediating the colonization functions of TCP. In the present study, we have used
site-directed mutagenesis to delineate two domains within the C-terminal region
that contribute to TCP structure and function. Alterations in the first domain,
termed the structural domain, result in altered pilus stability or morphology.
Alterations in the second domain, termed the interaction domain, affect
colonization and/or infection by CTX-bacteriophage without affecting pilus
morphology. In vitro and in vivo analyses of the tcpA mutants revealed that a
major function of TCP is to mediate bacterial interaction through direct pilus
pilus contact required for microcolony formation and productive intestinal
colonization. The importance of this function is supported by the finding that
intragenic suppressor mutations that restore colonization ability to colonization
deficient mutants simultaneously restore pilus-mediated bacterial interactions.
The alterations resulting from the suppressor mutations also provide insight into
the molecular interactions between pilin subunits within and between pilus
fibres.
PMID- 10692167
TI - A novel mechanism for control of antigenic variation in the haemagglutinin gene
family of mycoplasma synoviae.
AB - High-frequency phase and antigenic variation of homologous lipoprotein
haemagglutinins has been seen in both the major avian mycoplasma pathogens,
Mycoplasma synoviae and Mycoplasma gallisepticum. The expression and, hence,
antigenic variation of the pMGA gene family (encoding these lipoproteins in M.
gallisepticum) is controlled by variation in the length of a trinucleotide repeat
motif 5' to the promoter of each gene. However, such a mechanism was not detected
in preliminary observations on M. synoviae. Thus, the basis for control of
variation in the vlhA gene family (which encodes the homologous haemagglutinin in
M. synoviae) was investigated to enable comparison with its homologue in M.
gallisepticum and with other lipoprotein gene families in mycoplasmas. The start
point of transcription was identified 119 bp upstream of the initiation codon,
but features associated with control of transcription in other mycoplasma
lipoprotein genes were not seen. Comparison of three copies of vlhA revealed
considerable sequence divergence at the 3' end of the gene, but conservation of
the 5' end. Southern blot analysis of M. synoviae genomic DNA revealed that the
promoter region and part of the conserved 5' coding sequence occurred as a single
copy, whereas the remainder of the coding sequence occurred as multiple copies. A
9.7 kb fragment of the genome was found to contain eight tandemly repeated
regions partially homologous to vlhA, all lacking the putative promoter region
and the single-copy 5' end of vlhA, but extending over one of four distinct
overlapping regions of the 3' coding sequence. Examination of sequential clones
of M. synoviae established that unidirectional recombination occurs between the
pseudogenes and the expressed vlhA, with duplication of pseudogene sequence and
loss of the corresponding region previously seen in the expressed gene.
Expression of the 5' end of two variants of the vlhA gene showed that they
differed in their reaction with monoclonal antibodies specific for this region.
These data suggest that the control of vlhA antigenic variation in M. synoviae is
achieved by multiple gene conversion events using a repertoire of coding
sequences to generate a chimeric expressed gene, with the greatest potential for
variation generated in the region encoding the haemagglutinin. Thus, completely
distinct mechanisms have been adopted to control antigenic variation in
homologous gene families.
PMID- 10692168
TI - Transfer RNA modification, temperature and DNA superhelicity have a common target
in the regulatory network of the virulence of Shigella flexneri: the expression
of the virF gene.
AB - Full expression of the virulence genes of Shigella flexneri requires the presence
of two modified nucleosides in the tRNA [queuosine, Q34, present in the wobble
position (position 34) and 2-methylthio-N6-isopentenyladenosine (ms2i6A37,
adjacent to and 3' of the anticodon)]. The synthesis of these two nucleosides
depends on the products of the tgt and miaA genes respectively. We have shown
that the intracellular concentration of the virulence-related transcriptional
regulator VirF is reduced in the absence of either of these modified nucleosides.
The intracellular concentration of VirF is correlated with the expression of the
virulence genes. Overproduction of VirF in the tgt and the miaA mutants
suppressed the less virulent (tgt) or the avirulent (miaA) phenotypes
respectively, caused by the tRNA modification deficiency. This suggests that the
primary result of undermodification of the tRNA is a poor translation of virF
mRNA and not of any other mRNA whose product acts downstream of the action of
VirF. Shigella showed no virulence phenotypes at 30 degrees C, but forced
synthesis of VirF at 30 degrees C induced the virulence phenotype at this low
temperature. In addition, removal of the known gene silencer H-NS by a mutation
in its structural gene hns increased the synthesis of VirF at low temperature and
thus induced a virulent phenotype at 30 degrees C. Conversely, decreased
expression of VirF at 37 degrees C induced by the addition of novobiocin, a known
inhibitor of gyrase, led to an avirulent phenotype. We conclude that tRNA
modification, temperature and superhelicity have the same target - the expression
of VirF - to influence the expression of the central regulatory gene virB and
thereby the virulence of Shigella. These results further strengthen the
suggestion that the concentration of VirF is the critical factor in the
regulation of virulence in Shigella. In addition, they emphasize the role of the
bacterial translational machinery in the regulation of the expression of
virulence genes which appears here quantitatively as important as the well
established regulation on the transcriptional level.
PMID- 10692169
TI - The essential protein fap7 is involved in the oxidative stress response of
Saccharomyces cerevisiae.
AB - Pos9 (Skn7) is an important transcription factor that, together with Yap1,
induces the expression of oxidative stress target genes in Saccharomyces
cerevisiae. The activation of Pos9 upon an oxidative stress signal occurs post
translationally. In a mutant screen for factors involved in the activation of a
Pos9-dependent reporter gene upon oxidative stress, we identified the mutant fap7
1 (for factor activating Pos9). This point mutant failed to activate a Gal4-Pos9
hybrid transcription factor, assayed by hydrogen peroxide-induced GAL1-lacZ
reporter gene activities. Additionally, the fap7-1 mutant strain was sensitive to
oxidative stress and revealed slow growth on glucose compared with the wild type.
The fap7-1 mutation also affected the induction of the Pos9 target gene TPX1 and
of a synthetic promoter previously identified to be regulated in a Yap1- and Pos9
dependent manner. This lack of induction was specific as the fap7-1 mutant
response to other stresses such as sodium chloride or co-application of both
hydrogen peroxide and sodium chloride was not affected, as tested with the Pos9
independent expression pattern of a TPS2-lacZ reporter system. We identified the
gene YDL166c to be allelic to the FAP7 gene and to be essential. Fluorescence
microscopy of Fap7-GFP fusion proteins indicated a nuclear localization of the
Fap7 protein. Our data suggest that Fap7 is a nuclear factor important for Pos9
dependent target gene transcription upon oxidative stress.
PMID- 10692170
TI - The putative invasion protein chaperone SicA acts together with InvF to activate
the expression of Salmonella typhimurium virulence genes.
AB - SigD and SigE (Salmonella invasion gene) are proteins needed for optimal invasion
of Salmonella typhimurium into eukaryotic cells in vitro. SigD is a secreted
protein and SigE is a putative chaperone required for SigD stability and/or
secretion. SigD is secreted by a type III secretion apparatus encoded within a
pathogenicity island on the Salmonella chromosome known as Salmonella
pathogenicity island 1 (SPI1). The expression of sigDE, which is not linked to
SPI1, is co-ordinately regulated with the SPI1 genes and is dependent on the
transcriptional regulators SirA, HilA and InvF. These three proteins alone are
unable to activate transcription from the sigD promoter in Escherichia coli,
therefore it is likely that other factors are needed for expression. A screen for
genes required for the expression of a sigD-lacZYA reporter fusion found a mutant
with a transposon insertion in spaS, an SPI1 gene which encodes a putative inner
membrane component of the type III secretion system. The expression of a SPI1
operon encoding a putative chaperone (SicA) and several secreted proteins (Sips
B, C, D and A) was also reduced in this mutant. The regulation defect of the spaS
mutant was complemented by sicA and not by spaS. Because sicA is encoded
immediately downstream of spaS, the mutation in spaS was likely to be polar on
the expression of sicA. In addition, a sicA disruption mutant was as defective as
an invF deletion mutant for the expression of sigD, sicA and sipC reporter
fusions. The introduction of plasmids encoding invF and sicA into a non
pathogenic E. coli K-12 strain stimulated the transcription of both a sicA- and a
sigD-lacZYA promoter fusion. This result suggests that InvF and SicA are
sufficient for the expression of these genes. This is the first demonstration of
a positive regulatory role for a putative type III secretion system chaperone in
the expression of virulence genes.
PMID- 10692171
TI - Application of short tandem repeat of genomic DNA and mitochondrial DNA for
identification of mixed-up tissue specimens.
AB - Deoxyribonucleic acid (DNA) typing methods, short tandem repeat of genomic DNA
and mitochondrial DNA with the use of polymerase chain reaction amplification,
were applied to formalin-fixed, paraffin-embedded tissues submitted for
diagnosis, to identify and sort out mixed-up tissue specimens. These techniques
were found to be reliable, reproducible and specific for personal identification,
and thus to eliminate the need for further examinations and to prevent
unnecessary surgery.
PMID- 10692172
TI - Immunohistochemical detection of cytokeratin and epithelial membrane antigen in
leiomyosarcoma: a systematic study of 100 cases.
AB - Although 'aberrant' expression of the epithelial markers, cytokeratin (CK) and
epithelial membrane antigen (EMA), in leiomyosarcoma has been described
previously, there has not been a study of this phenomenon with
clinicopathological correlation in a large series of lesions at different
anatomical sites. We investigated systematically the immunohistochemical
reactivity for CK and EMA in 100 cases of leiomyosarcoma. CK and EMA were
positive in 38% and 44% of the cases, respectively. Although staining was usually
focal, extensive immunoreactivity was observed in 11% with CK and 6% with EMA.
There was no correlation between immunoreactivity for CK and EMA in
leiomyosarcomas and non-neoplastic smooth muscle at the same location.
Immunoreactivity for CK and EMA was not correlated with the location, age, sex,
histological grade, or histological features, except for more frequent EMA
positivity in vascular and uterine tumors than in soft tissue cases. These
results indicate that CK and/or EMA-positive leiomyosarcomas do not have
distinctive clinicopathological features differing from those of negative cases.
However, the considerable frequency of immunoreactivity for these epithelial
markers in leiomyosarcoma, occasionally with diffuse and strong immunopositivity,
should be recognized as a potentially serious diagnostic pitfall in the
differential diagnosis of other malignant spindle cell neoplasms.
PMID- 10692173
TI - Existence and distribution of melanocytes and HMB-45-positive cells in the human
minor salivary glands.
AB - The existence and distribution of melanocytes in the human minor salivary glands
were investigated in a series of autopsy and biopsy materials. The cells with the
following characteristics were regarded as melanocytes; spindle-shaped or
dendritic cells with fine granular pigments: (i) stained brownish-black by
hematoxylin-eosin stain, and black by Masson-Fontana's silver impregnation
method; and (ii) disappeared after treatment with peroxide and potassium
permanganate solution. In addition, the expression of antigen identified by anti
HMB-45 antibody in serial sections with melanocytes was examined. Melanocytes
were found in eight (1.8%) of 445 cases, and there was no relationship between
the existence of melanocytes and significant diseases of the subjects. Various
numbers of melanocytes were distributed in fibrous tissue around the interlobular
ducts, intralobular ducts and acini, but were not in direct contact with the
epithelia. Neither melanocytes nor melanin granules were found in the salivary
gland epithelia. HMB-45-positive cells without intracytoplasmic fine granules
were found solitarily or in small groups in periductal and periacinar fibrous
tissues with or without slight infiltration of small mononuclear cells.
PMID- 10692174
TI - Functional aspects of megamitochondria isolated from hydrazine- and ethanol
treated rat livers.
AB - It is essential to analyze functions of megamitochondria (MG) to elucidate the
mechanism of the formation of MG induced under various pathological conditions.
The MG fraction obtained by a routine isolation procedure for normal mitochondria
always consists of a mixed population of mitochondria enlarged to various degrees
and also normal-sized ones. The purpose of the present study is to answer the
question of whether or not data obtained from the MG fraction consisting of such
a heterogeneous population of mitochondria with respect to their sizes really
reflect functions of MG. In the present study mitochondria were obtained from the
livers of rats treated with a 1% hydrazine diet for 8 days and those given 32%
ethanol in drinking water for up to 2 months using various isolation procedures.
Results obtained are summarized as follows: (i) mitochondria enlarged to various
degrees and normal-sized ones are sometimes connected with each other by a narrow
stalk in the hepatocyte of hydrazine-treated animals, and such connections are
maintained to some extent when mitochondria are isolated; and (ii) mitochondria
obtained from experimental animals by a routine isolation procedure for
mitochondria ((700-7000)gR2"') and those obtained by alternative isolation
procedure yielding the heavy ((500-2000)gR2"') and light ((2000-7000)gR2"')
fractions show some functional similarities: decreases in the content of
cytochrome a + a3; decreases in oxygen consumptions and phosphorylating
abilities; decreases in monoamine oxidase and cytochrome c oxidase activities;
lowered membrane potential of mitochondria; decreases in the rate of the
generation of reactive oxygen species. These results may suggest that
mitochondria enlarged to various degrees and normal-sized ones are functionally
similar to each other and that the MG fraction obtained by a routine isolation
procedure for normal mitochondria can be applied to the study of the function of
MG.
PMID- 10692175
TI - Endotoxin priming and liver damage by experimental duodenal obstruction in the
rat.
AB - To verify whether endotoxin (LPS) might act as a priming cofactor of liver injury
caused by obstructing the duodenum, four groups of male Wistar rats were studied.
The first two groups comprised rats in which a closed duodenal loop (CDL) was
created: CDL, n = 6 and CDL + LPS, n = 7; the next two groups comprised sham
operated animals: Sham n = 6 and Sham + LPS, n = 6. LPS, 400 microg/kg
bodyweight, was administered i.p. to the rats belonging to groups CDL + LPS and
Sham + LPS, 24 h before laparotomy. Twenty-four hours after laparotomy the
animals were killed. Damage to bile ducts, extent and grading of coagulative and
lytic spotty necrosis in liver tissue were evaluated morphologically. Coagulative
necrosis was severe in four of seven rats of the group CDL + LPS, mild in six of
six rats of group CDL, and absent in four of six and five of six rats of groups
Sham and Sham + LPS (chi2 32.8, P = 0.0001). The animals of group CDL + LPS had
more frequently diffuse lytic spotty necrosis than the animals in the three other
groups (chi2 9.57 P<0.01). The results of our study indicate that, in rodents
subjected to a closed duodenal loop, priming with LPS exacerbates liver injury
due to cholate stasis.
PMID- 10692176
TI - Primary hepatic leiomyosarcoma in a patient with hepatitis C virus-related liver
cirrhosis.
AB - We describe an autopsy case of primary hepatic leiomyosarcoma in a 68-year-old
man with hepatitis C virus-related liver cirrhosis. The patient, who had a
history of acute hepatitis 20 years previously, died of a ruptured hepatic tumor.
At autopsy, a well-circumscribed 14 x 16 x 15 cm tumor replaced the medial site
of the right hepatic lobe with multiple intrahepatic and distant metastases.
Histologically the tumor, which had extensive central necrosis, consisted
predominantly of well or moderately differentiated spindle-shaped cells, which
were positive for smooth muscle actin and vimentin on immunohistochemical
staining. In addition, clusters of markedly atypical cells and myxoid change of
the matrix were discretely found in the focal and small areas of the tumor. These
findings indicated that many sections were necessary for the histologically
accurate estimation of primary hepatic smooth muscle tumor. The histological
examination of a non-tumorous lesion showed liver cirrhosis. Hepatitis C virus
was detected in the cytoplasm of cirrhotic hepatocytes by immunohistochemistry
and reverse transcriptase-polymerase chain reaction, but not in the tumor cells.
This suggested that the virus was not directly involved in the development of
primary hepatic leiomyosarcoma.
PMID- 10692177
TI - Adenocarcinoma of the renal pelvis with vimentin-positive intracytoplasmic
inclusions.
AB - A case of mucus-producing papillary adenocarcinoma of the renal pelvis associated
with multiple renal calculi in a 16-year-old male is reported. The majority of
the tumor cells contained large, round or cone-shaped, vimentin-positive
intracytoplasmic inclusions, which exhibited some morphological and
immunohistochemical resemblance to inclusions found in malignant rhabdoid tumor
of the kidney. An intracytoplasmic accumulation of mucus was also noted in some
tumor cells. The patient is free from recurrence and metastasis after a
nephrectomy.
PMID- 10692178
TI - Micropapillary variant of transitional cell carcinoma of the ureter.
AB - Micropapillary variant of transitional cell carcinoma (TCC) is a rare entity,
having a distinct micropapillary component mimicking papillary serous carcinoma
of the ovary and has been reported exclusively in the urinary bladder. We
experienced a case of micropapillary variant of TCC in the ureter. The tumor
showed a predominant proportion of micropapillary component and accompanied a TCC
in situ lesion and a high-grade TCC. A metastatic lesion in the regional lymph
node also showed an entirely micropapillary pattern. Initially, our case was
confused with adenocarcinoma, especially metastatic, because the micropapillary
architecture resembled an abortive glandular structure and tumor cell nests were
predominantly located in empty spaces mimicking vascular invasion. The patient
died with peritoneal metastases 20 months after the initial diagnosis. We report
the first case of a micropapillary variant of TCC occurring in the ureter.
PMID- 10692179
TI - Anaplastic carcinoma of the pancreas with rhabdoid features.
AB - The malignant rhabdoid tumor (MRT) is histologically characterized by the
invasive proliferation of polygonal to ovoid cells with abundant eosinophilic
cytoplasm and eccentric vesicular nuclei with a prominent nucleolus. MRT
frequently occurs in the kidney, but may also arise in other organs. However, MRT
should be strictly distinguished from carcinomas with rhabdoid features. A post
mortem examination of a 68-year-old woman found an anaplastic carcinoma of the
pancreas with rhabdoid features displaying extensive invasion into the
neighboring tissues. To the best of our knowledge, this is the first case of a
pancreatic tumor with rhabdoid features. Pathologists should consider that
carcinomas showing rhabdoid features may also appear in the pancreas. As
pancreatic tumors with rhabdoid features have characteristic histopathological
features and poor prognosis compared to other pancreatic tumors, careful
histopathological differential diagnosis is important.
PMID- 10692180
TI - Sebaceous carcinoma of the breast.
AB - We report on a rare distinctive variant of infiltrating ductal carcinoma
characterized by sebaceous differentiation of tumor cells. The neoplasm was
identified in a lumpectomy specimen from a 45-year-old woman with extensive
metastatic disease. In addition to conventional in situ and invasive ductal
components, approximately half of the tumor cells exhibited a phenotype
resembling tumors of the sebaceous skin appendage with coarsely vacuolated
cytoplasm and peripherally displaced nuclei. The sebaceous moiety was also
present in the distant metastatic deposits. There was no evidence of mucin
production by tumor cells. Ultrastructurally, empty-appearing non-membrane bound
vacuoles attested to the sebaceous cells' lipid content. The immunoprofile of the
lesion included positivity for cytokeratin and epithelial membrane antigen.
Vimentin, S100 protein and carcinoembryonic antigen were not expressed. Most
tumor cell nuclei reacted with antibodies to oestrogen and progesterone receptors
but failed to show overexpression of the HER2/neu protein. The MIB-1 labeling
index averaged 16%. At variance with sebaceous breast carcinomas on record, the
present case is notable for its prolonged clinical course.
PMID- 10692181
TI - Signet-ring cell carcinoma of the breast.
AB - Primary signet-ring cell carcinoma of the breast is a very rare tumor and is not
recognized as an independent entity of the World Health Organization
classification of breast tumor. Primary signet-ring cell carcinoma of the breast
is usually considered as a variant of mucinous carcinoma or lobular carcinoma and
usually originates from the lobular epithelium. A case of primary signet-ring
cell carcinoma of the breast in a 68-year-old woman is presented. Histologically,
the majority of neoplastic cells had an intracytoplasmic mucin collection. The
histological presence of ductal carcinoma in situ, absence of lobular lesion and
immunoreactivity for estrogen and progesterone receptors implicated the tumor
cells arising from ductal epithelium. The papillary or organoid growth pattern is
characteristic in this case. The patient underwent a modified radical mastectomy
and was subsequently followed up for 6 months.
PMID- 10692182
TI - Blastomatous tumor with teratoid features of nasal cavity: report of a case and
review of the literature.
AB - A case of blastomatous tumor with teratoid features is presented. The polypoid
mass was observed in the left nasal cavity of a 72-year-old man. Histologically,
the lesion was composed of neuroepithelial cells with blastomatous appearance,
cystic squamous nests filled with keratin materials, many mucous glands, complex
tubular and glandular structures with edematous fibroblastic stroma. Sinonasal
neoplasms including teratoid components and immature neuroepithelium are
exceedingly rare. We suggest that the term 'immature teratoma' is more suitable
than blastoma or blastomatous tumor when there is no carcinomatous or sarcomatous
component besides the immature neuroepithelium and teratoid elements.
PMID- 10692183
TI - Uterus-like mass of the small bowel mesentery.
AB - A case of a uterus-like mass arising from the mesentery is reported. A mass
measuring 14x11 cm was noted in the small bowel mesentery of a 59-year-old woman.
Histologically, the lesion consisted of endometrial-type and fallopian tube-type
mucosa surrounded by thick bundles of smooth muscle cells. Since the first report
by Cozzutto in 1981, 10 cases of uterus-like mass, that included seven ovarian
and three extraovarian cases, have been reported. To our knowledge, the present
lesion was the first case originating from the mesenteric region. Three
hypotheses of this rare lesion: (i) congenital anomaly; (ii) metaplasia; and
(iii) heterotopia theories are reviewed.
PMID- 10692185
TI - We Are Marching, Marching ellipsis.
PMID- 10692184
TI - Proliferative activity and subtyping of calcifying odontogenic cyst.
PMID- 10692186
TI - Prediction of short- and long-term outcomes by troponin T levels in low-risk
patients evaluated for acute coronary syndromes.
AB - STUDY OBJECTIVE: Recent reports suggest a short series of cardiac troponin (cTnT)
testing effectively identifies patients at risk for cardiac events. However,
there are few studies validating this strategy. The purpose of this study was to
determine the ability of cTnT levels to predict short- and long-term outcomes in
low-risk patients with suspected acute coronary syndromes. METHODS: This
prospective longitudinal study was conducted in a 20-bed emergency department
observation unit. Patients at low risk for acute coronary ischemia, with a normal
creatine kinase-isoenzyme subunit MB (CKMB) index, were admitted to an
observation unit for chest pain evaluation. Serum cTnT levels were measured at
baseline and at 4, 8, and 16 hours after admission. The main outcome measures
were adverse cardiac events (death, acute myocardial infarction, unstable angina,
revascularization) during the index visit and within 6 months after discharge.
Using manufacturer's recommendations, the cTnT level was considered abnormal if
it exceeded 0.2 microg/L. RESULTS: Two hundred sixty-six patients were evaluated.
Twenty-one (7.9%) had an adverse event during their index hospitalization.
Troponin testing identified only 2 (9.5%) of these patients. Twenty (7.5%) had a
cardiac event within 6 months; none were identified by cTnT testing. The
sensitivity and specificity were 9.5% and 99.2%, respectively, at the index
visit, and 0% and 98.4% at 6 months. The positive and negative predictive values
were 50% and 93%, respectively, at the index visit; and 0% and 92% at 6 months.
CONCLUSION: Determination of troponin T levels has a low sensitivity and high
specificity for predicting outcomes in low-risk patients evaluated for suspected
acute coronary syndromes. This study does not support a strategy of relying
solely on troponin testing for disposition decisions.
PMID- 10692187
TI - Emergency airway management in penetrating neck injury.
AB - STUDY OBJECTIVES: Airway management in the context of penetrating neck injury is
a challenging scenario. Management decisionmaking has not been well studied and
the initial airway approach remains controversial. We examined various initial
emergency airway techniques and their success in the setting of penetrating neck
trauma. METHODS: A retrospective study was conducted of emergency department
intubations in penetrating neck injury from January 1, 1993, to December 31,
1996, at a Level I trauma center. Cases of out-of-hospital traumatic arrest or
out-of-hospital intubation were excluded. Successful airway management was
defined as endotracheal tube placement confirmed by clinical evaluation, pulse
oximetry, chest radiography, and end-tidal CO(2) detection. RESULTS: During the
study period, 748 consecutive patients with penetrating neck injury were
evaluated in the ED. Of these, 82 (11%) were deemed to require immediate airway
management. Twenty-four of the 82 were excluded because of out-of-hospital
traumatic arrest or out-of-hospital intubation, resulting in a study population
of 58 patients. Of these 58 patients, 39 had initial rapid sequence intubation
using succinylcholine with a 100% success rate. Five comatose patients had
successful orotracheal intubation without paralysis, and 2 patients underwent
successful emergency tracheostomy. The remaining 12 patients had initial
fiberoptic intubation by otolaryngology clinicians, which was unsuccessful in 3
patients. All 3 of these patients were subsequently successfully orotracheally
intubated using the rapid sequence intubation technique. Therefore, oral
endotracheal intubation was the definitive method of airway management in 47
(81%) of the 58 patients and was successful in all cases. CONCLUSION: Rapid
sequence intubation was the most commonly performed initial technique by
emergency physicians and was safe and effective in all cases attempted.
Furthermore, rapid sequence intubation methodology resulted in successful
intubation of the fiberoptic intubation failures. Physicians with airway
expertise should consider using rapid sequence intubation as an initial airway
technique in managing patients with penetrating neck injury who require airway
control.
PMID- 10692188
TI - Use of alternative therapies among emergency department patients.
AB - STUDY OBJECTIVE: To assess emergency department patients' use of alternative
therapies. METHODS: This study used a cross-sectional observational survey of a
convenience sample of ED patients. A trained research assistant administered a
written questionnaire asking patients about alternative therapies. RESULTS: Of
the 139 patients surveyed, 78 (56%) had tried alternative therapies in the past,
68 (87%) of whom believed that they were effective. The most frequently tried
alternative therapies were massage therapy (31%), chiropractic (30%), herbs
(24%), meditation (19%), and acupuncture (15%). Most patients (70%) who tried
alternative therapies did not inform their physicians of such practice.
CONCLUSION: Most ED patients in our sample had tried alternative therapies and
among these patients, most did not inform their physicians. Herbal therapy in
particular had been tried by about 1 in 4 patients. Emergency physicians should
routinely question their patients regarding the use of alternative therapies,
particularly herbal preparations, which may cause adverse effects.
PMID- 10692189
TI - Does adjunctive midazolam reduce recovery agitation after ketamine sedation for
pediatric procedures? A randomized, double-blind, placebo-controlled trial.
AB - STUDY OBJECTIVE: Despite widespread use of adjunctive benzodiazepines during
ketamine sedation, their efficacy in reducing recovery agitation in children has
never been studied. We wished to characterize the nature and severity of recovery
agitation after ketamine sedation in children treated in the emergency department
and to determine whether the addition of adjunctive midazolam reduces the
magnitude of such recovery agitation. METHODS: The study was a randomized, double
blind, clinical trial of adjunctive midazolam versus placebo during ketamine
sedation. We enrolled 104 children aged 12 months to 15 years (median age, 6
years) at a combined university medical center and children's hospital. Subjects
received either intravenous midazolam (0.05 mg/kg up to 2 mg) or placebo after
intravenous administration of a ketamine loading dose (1.5 mg/kg). Treating
physicians and nurses independently noted the presence of crying, hallucinations,
and nightmares during recovery and graded recovery agitation by using a 100-mm
visual analog scale. Preprocedure agitation and external stimulation during
recovery were also graded. The time from ketamine injection until each subject
met the recovery criteria was recorded. RESULTS: Fifty-three subjects received
midazolam, and 51 received placebo. Potentially confounding variables were
similar between the groups. Sedation efficacy, adverse effects, and recovery time
were also similar between groups. Interobserver agreement between physician and
nurse assessments was substantial. Median physician assessment of recovery
agitation was 4 mm (interquartile range, 2 to 19) in the midazolam group and 5 mm
(interquartile range, 3 to 14) in the placebo group (difference -1; 95%
confidence interval -3 to 2; P =.705). Recovery agitation was moderately
correlated with preprocedure agitation (rho=0.486) but not with external
stimulation during recovery (rho=0.147). CONCLUSION: Recovery agitation is common
but generally of very low magnitude after ketamine sedation in children in the
ED. We observed a median physician rating of 5 mm on a 100-mm visual analog
scale, a score that we believe to be clinically insignificant. The degree of
recovery agitation after ketamine sedation is significantly related to the degree
of preprocedure agitation. In this study, concurrent midazolam did not diminish
such agitation and had no measurably beneficial effect. Use of adjunctive
benzodiazepines in pediatric ketamine sedation appears unnecessary.
PMID- 10692190
TI - Prospective evaluation of mild to moderate pediatric acetaminophen exposures.
AB - STUDY OBJECTIVE: To determine whether pediatric patients with acute, mild to
moderate acetaminophen exposures, treated with home monitoring alone, develop
systemic signs of hepatic injury. METHODS: A prospective, observational study of
calls to a regional poison center over a 25-month period was performed. Patients
were eligible for the study if they were younger than 7 years and had an acute
maximum possible acetaminophen exposure of up to 200 mg/kg. Exclusion criteria
included previous decontamination measures, possibility of ingestion of an
extended-release preparation, health or medication issues that could increase
susceptibility to hepatotoxicity, current symptoms of hepatotoxicity, and
indeterminable ingestions. Study protocol included reviewing the signs and
symptoms of early and late acetaminophen toxicity, a 4- to 6-hour follow-up call,
and a 72-hour follow-up call. Outcome measures were defined as a verbal report by
the patient's parent or guardian of the presence or absence of signs or symptoms
of hepatotoxicity. RESULTS: A total of 1,039 patients were enrolled in the study,
including 519 girls and 520 boys, with exposures ranging from 20 to 200 mg/kg.
Eighteen patients were lost to follow-up; data were incomplete for 2 patients. At
72-hour follow-up, the remaining 1,019 patients were all doing well, without
signs or symptoms of hepatotoxicity. CONCLUSION: On the basis of these data,
pediatric patients with acute acetaminophen exposures of up to 200 mg/kg, treated
with home monitoring alone, do not develop signs or symptoms of hepatic injury.
PMID- 10692191
TI - Injury prevention and emergency medical services for children in a managed care
environment.
AB - Each year, 1 in 5 US children receives medical care as a result of injury.
Injuries are the leading cause of medical spending for children ages 5 to 21
years, accounting for more than 20% of hospital admissions and days spent in the
hospital. Pediatric injuries become an important issue for managed care
organizations because of concern for member safety and increasing medical costs
related to treatment. Because effective prevention decreases health care
consumption, injury prevention often costs less than treating injuries. Simple
devices, such as bicycle helmets, smoke detectors, and child safety seats, help
keep children safe and save money. Appropriate emergency care at the scene of an
injury, poison control centers that dispense expert advice over the telephone,
and triaged regional trauma systems improve the outcome and save money at the
same time. This article continues the white paper series by the Emergency Medical
Services for Children Managed Care Task Force.
PMID- 10692192
TI - Adolescent injury in the emergency department: opportunity for alcohol
interventions?
AB - STUDY OBJECTIVE: Alcohol, the most commonly used substance among adolescents, is
frequently associated with injury. Little is known regarding the drinking
characteristics of injured adolescents. Such data are critical for developing
emergency department interventions to decrease alcohol-related injury among
adolescents. We sought to describe the drinking characteristics of injured
adolescents and to describe the relationship of injury severity and mechanisms
with drinking characteristics. METHODS: This study was a prospective cohort study
performed in a university hospital (sampled May 1, 1995, to July 15, 1995) and a
large urban teaching hospital (sampled May 1, 1996, to August 1, 1996). The
participants were aged 12 to 20 years, presenting within 6 hours of an injury. We
performed a saliva alcohol test and self-administered questionnaire. Age, sex, E
code, injury severity score (ISS), and ED disposition were recorded. An alcohol
frequency/quantity index was calculated. Descriptive statistics and 95%
confidence intervals were calculated. RESULTS: Two hundred sixty-three patients
with a mean age of 17 years and a mean ISS of 2.1 (SD 3.5) were recruited. One
hundred fifty-two (50%) were males, and 33 (13%) were admitted. Ten (4%) patients
had a positive saliva alcohol test response. On average, within the last year,
these adolescents had 1.7 adverse alcohol consequences. Sixty percent drank in
unsupervised settings, and 36% reported drinking 5 or more drinks in a row.
CONCLUSION: Alcohol use/misuse is a substantial problem among injured adolescents
regardless of severity or mechanism of injury. ED physicians should consider
screening/intervention or primary prevention of alcohol problems for all injured
adolescents.
PMID- 10692193
TI - Lethality of firearm-related injuries in the United States population.
AB - STUDY OBJECTIVE: To characterize differences in the lethality of firearm-related
injuries in selected demographic subgroups using national representative data on
fatal and nonfatal firearm-related injuries. We also characterize the lethality
of firearm-related injuries by intent of injury and anatomic location of the
gunshot wound. METHODS: We analyzed case-fatality rates (CFRs) of firearm-related
injuries in the United States by using death data from the National Vital
Statistics System and data on nonfatal injuries treated in US hospital emergency
departments from the National Electronic Injury Surveillance System. National
estimates of crude and age-adjusted CFRs are presented by sex, race/ethnicity,
age, intent, and primary body part affected. RESULTS: Each year during the study
period (July 1992 through December 1995), an estimated 132,687 persons sustained
gunshot wounds that resulted in death or treatment in an ED. The overall age
adjusted CFR among persons who sustained firearm-related injuries was 31.7% (95%
confidence interval [CI] 27.7 to 35.6). The age-adjusted CFR for persons who were
alive when they arrived for treatment in an ED (11. 3%; 95% CI 9.4 to 13.2) was
about one third as large as the overall CFR. The age-adjusted CFR varied by sex,
race/ethnicity, and age, but these differences depended on intent of injury. For
assaultive injuries, the age-adjusted CFR was 1.4 times higher for females (28.
7%) than males (20.6%). For intentionally self-inflicted injuries, the age
adjusted CFR was 1.1 higher for males (77.7%) than females (69.1%). For assaults,
the age-adjusted CFR was 1.5 times higher for whites (29.5%) than blacks (19.2%).
For assaultive and intentionally self-inflicted injuries among persons 15 years
and older, the age-specific CFR increased with age. Persons shot in the head (age
adjusted CFR, 61.0%) were 3.3 times as likely to die as those shot in other body
parts (age-adjusted CFR, 18.7%). CONCLUSION: The lethality of firearm-related
injuries was influenced strongly by the intent of injury and body part affected.
The high lethality of firearm-related injuries relative to other major causes of
injury emphasizes the need to continue prevention efforts and efforts to improve
access to care and treatment (including emergency medical and acute care
services) to reduce the number and increase survivability of firearm-related
injuries.
PMID- 10692194
TI - Effect of state legislation prohibiting denial of emergency department patient
claims.
AB - STUDY OBJECTIVE: On July 1, 1996, two Florida state laws were implemented to
prevent denial of legitimate patient claims. Our objective was to determine
whether the laws have been effective in reducing inappropriate denials as
measured by the proportion of claims and charges denied. METHODS: A comprehensive
set of claims for in-state emergency physician services from a physician billing
company were analyzed for the period January 1996 through June 1997, covering 6
months before and 12 months after the effective date of state legislation. The
number of facilities included in the data varied from 55 to 67 (mean 63). Denials
were classified into 6 categories by payer type. Gross denials were those claims
that were completely not paid by the payer, net denials represented the amount
denied after patient payments. Downcoding was not examined in this study. Main
outcome measures were the proportion of claims and charges denied before and
after July 1, 1996. RESULTS: The classification of relative proportions of
primary payers did not change appreciably over the study period. The proportion
of denied claims decreased significantly (Kruskal-Wallis P <.001), starting 2
months after implementation. CONCLUSION: After initiation of state legislation,
payers continue to inappropriately deny claims, although the number of claims and
total charges denied has decreased. In response to this legislation, payers are
denying larger claims and patient copayments have increased.
PMID- 10692195
TI - Managed care organization authorization denials: lack of patient knowledge and
timely alternative ambulatory care.
AB - STUDY OBJECTIVE: To assess patient knowledge of managed care organization (MCO)
regulations, availability of alternative ambulatory care, and patient outcome
after MCO insurance authorization denial for an emergency department visit.
METHODS: A medical screening examination and a follow-up structured interview
were conducted with patients denied authorization for ED visits. The study was
conducted at a large urban hospital with 36,000 annual ED visits and 40% MCO
patients. RESULTS: During a 7-month period, 151 patients did not receive MCO
authorization for ED care. The interview response rate was 75% (104/138) with 13
patients excluded. Eighty-three percent (86/104) of respondents came to the ED
because they believed their problem was an emergency. Four percent (4/104) of the
respondents had been instructed to go to the ED but were later denied
authorization, whereas 85.6% (89/104) did not know that the MCO could deny
payment. Only 37% (38/104) of the respondents reported having received
instruction on the MCO preauthorization process, whereas of the 19% who contacted
their MCO as instructed, all resulted in scheduling difficulties. Although 57%
(59/104) received follow-up within 24 hours, 11% (11/104) of the respondents had
a subsequent return visit to the ED with a subsequent admission rate of 4%
(4/104). CONCLUSION: Few patients are aware of the need for MCO preauthorization
for ED care, and almost half do not receive alternative care within 24 hours. A
significant number of patients (11%) returned to the ED with an admission rate of
4%.
PMID- 10692196
TI - Inadequate hospital reimbursement for victims of motor vehicle crashes due to
health reform legislation.
AB - STUDY OBJECTIVE: Effective for 1997, health reform legislation in New York
resulted in a change in hospital reimbursement for victims of motor vehicle
crashes. We evaluated the impact of this change from no-fault to Medicaid rates
on the financial viability of a regional trauma center within an academic medical
center. METHODS: This study represents a retrospective review of the trauma
registry for all motor vehicle-related injuries (meeting the statewide definition
of trauma) admitted to a regional trauma center for a 9-month period just before
the legislation implementation date. Charges, costs, and projected reimbursement
were calculated by standard hospital accounting methods. Profit or loss
(reimbursement minus costs) was calculated by standard hospital accounting
methods for each admission using no-fault and Medicaid reimbursement rates.
RESULTS: One hundred seventy-three cases during the 9-month period generated
total charges of $4,112,174, total costs of $3,447,110, and estimated total
profit of $800,084 ($4,625 per case) using no-fault reimbursement and a total
loss of $184,154 ($1,064 per case) using Medicaid reimbursement. For the 31
patients with diagnosis-related groups (DRGs) that were specifically created in
New York to ensure adequate reimbursement for multiple significant trauma (730
through 734 and 792 through 794), no-fault reimbursement resulted in an average
profit of $371 per case and Medicaid generated a loss of $6,118 per case. Actual
payments for the study population were almost $500,000 less than estimated.
CONCLUSION: Changes in rates of no-fault insurance payments to hospitals will
result in inadequate reimbursement for motor vehicle crash victims admitted to a
regional trauma center, undermining the viability of the regional trauma system.
PMID- 10692197
TI - Effect of a state definition of an "emergency medical condition" legislation on
medicaid managed care organization reimbursement.
AB - STUDY OBJECTIVE: The state of Michigan passed Public Act 136 of 1997 requiring
Medicaid managed care organizations (MMCOs) to pay for emergency services
whenever presenting symptoms constituted an "emergency medical condition." The
objective of this study was to evaluate MMCO reimbursement before and after
enactment of this state law. METHODS: We conducted a retrospective comparison of
reimbursement for lacerations needing repair (identified using Current Procedural
Terminology codes from computerized billing data) for 2 time periods (before the
state law was applicable [January through March 1998] and after the state law was
applicable [April through June 1998]) from MMCO enrollees in 7 different MMCOs
presenting to 4 urban emergency departments. Three months after billing
submission was allowed for payment. Only refusal of reimbursement was evaluated.
Data were analyzed using chi(2) and Fisher's exact test (values of P <.05 were
considered significant). RESULTS: The total number of MMCO patients
evaluated/total number of ED patients evaluated for the 2 periods was
1,769/32,646 and 3, 376/30,901, respectively (P <.05). The number of MMCO
lacerations with no reimbursement/total number of MMCO lacerations for the 2
periods was 4/135 (3%) and 78/196 (40%), respectively (P <.001). CONCLUSION:
Reimbursement by MMCOs for a procedure chosen to reflect a state-defined
"emergency medical condition" is inadequate and significantly decreased during
the 2 periods, with a significant increase in MMCO patients evaluated.
PMID- 10692198
TI - Reimbursement impact of medicaid managed care organizations replacing standard
medicaid.
AB - STUDY OBJECTIVE: To evaluate the reimbursement difference for Medicaid managed
care organization (MMCO) enrollees compared with Medicaid enrollees for emergency
department patients with disease conditions that appear to meet the "prudent
layperson" definition of an emergency medical condition. METHODS: This study used
a retrospective reimbursement review of computerized billing data of
reimbursement denials for 4 procedures (using Current Procedural Terminology
codes for endotracheal intubation, cardiopulmonary resuscitation, central line
placement, and lumbar puncture) and 1 International Classification of Diseases,
ninth revision condition (chest pain) on MMCO patients from 7 MMCOs compared with
standard Medicaid patients presenting to 4 EDs during a 6-month period (January
through June 1998). Exclusion criteria were late bills that did not allow at
least 90 days for payment and bills submitted on behalf of patients that were not
covered at the time of service by Medicaid or MMCO. Data were analyzed using
Fisher's exact test. RESULTS: The total number of MMCO and Medicaid patients
evaluated/total ED patients evaluated was 5,153/63,552 and 6,020/63, 552,
respectively. The number of nonreimbursed procedures/total number of procedures
performed on MMCO and Medicaid patients was 35/93 and 14/88, respectively (P
<.05). The number of nonreimbursed chest pain patients/total chest pain patients
evaluated for MMCO and Medicaid enrollees was 65/277 and 12/199, respectively (P
<.05). CONCLUSION: MMCOs reimburse significantly less than Medicaid does for ED
patients with conditions that a prudent layperson would consider an emergency.
PMID- 10692199
TI - Analysis of insurance payment denials using the prudent layperson standard.
AB - STUDY OBJECTIVES: To review a sample of emergency department payment denials
characterized as "not a medical emergency" and to determine medical necessity for
each visit using an arbitrary "prudent layperson" standard. METHODS: This study
was conducted at a university hospital and was an analysis of a convenience
sample of ED payment denials classified as "not a medical emergency" by 2 managed
care providers. Each corresponding visit was analyzed if the bill was still
outstanding in September 1998. ED records were analyzed for chief complaint and
risk factors for morbidity. Any minor disorder lasting 1 day or more and with
normal vital signs recorded was considered to not meet the prudent layperson
standard of an emergency. Visits for minor trauma that occurred the same day that
also required radiographs or suturing were considered emergencies. RESULTS: Two
hundred ED visits were retrospectively reviewed. Payer 1 denied 44 visits, of
which 38 (86%) met the prudent layperson standard; payer 2 denied 156 visits, of
which 113 (62%) met the standard (P >.05). CONCLUSION: A large proportion of ED
visits for which payment is denied as "not a medical emergency" may meet the
prudent layperson definition of an emergency.
PMID- 10692200
TI - The uninsured: emergency medicine's challenge to our political leaders.
PMID- 10692201
TI - Midazolam with ketamine: who benefits?
PMID- 10692202
TI - Cerebral arterial gas embolism by helium: an unusual case successfully treated
with hyperbaric oxygen and lidocaine.
AB - A 27-year-old man inhaled helium from an unregulated pressurized cylinder and
underwent cerebral arterial gas embolism (CAGE), leaving him blind and with
radiologic evidence initially suggesting cortical infarction. There was complete
recovery of vision and substantial regression of the radiologic changes after 4
hyperbaric oxygen treatments and a 54-hour lidocaine infusion, which began 6
hours after the accident. This is the second reported case of CAGE occurring by
this mechanism and the first case of unequivocal CAGE in which lidocaine has been
used as an adjunctive treatment with hyperbaric oxygen.
PMID- 10692203
TI - Controversial company: the prudent layperson standard and the patients' bill of
rights.
PMID- 10692204
TI - Use of pulsed-field gel electrophoresis for investigation of a cluster of
invasive group A streptococcal illness - Spokane, Washington, 1999.
PMID- 10692205
TI - Mooki and Ben.
PMID- 10692206
TI - Methanol intoxication.
PMID- 10692207
TI - Potential for duragesic patch abuse.
PMID- 10692208
TI - Disaster medical education for all physicians and physician extenders.
PMID- 10692209
TI - Disaster Medical Education for All Physicians and Physician Extenders.
PMID- 10692211
TI - Esophageal cytology in the follow-up of patients with treated upper aerodigestive
tract malignancies.
AB - BACKGROUND: Patients with an history of carcinoma of the upper aerodigestive
tract are at high risk for recurrence or the development of new tumors in this
region. In the majority of follow-up protocols, these patients undergo radiologic
and endoscopic evaluation as a means of surveillance for the early detection of
recurrence. The brush biopsy-capsule technique represents a noninvasive and
inexpensive screening device for this patient population. In the current study,
the authors retrospectively assessed the sensitivity, specificity, and predictive
value of esophageal brush-capsule cytology for the detection of malignant lesions
of the upper aerodigestive tract in this high risk patient population. METHODS:
Cytologic specimens from 334 patients with previously treated upper aerodigestive
malignancies were available for review. The cytologic, endoscopic, and clinical
follow-up of each case were studied over a follow-up period of 3 years. Gold
standard was the clinical follow-up for the negative cases (who were not
submitted to biopsy) and biopsy for the positive cases. Sensitivity, specificity,
and predictive value were calculated. RESULTS: Using cytology 33 malignancies
were detected in 25 patients during a 3-year follow-up period. The test was found
to have a sensitivity of 88.7% and a specificity of 90.7%. In 66% of cases the
malignancies were located in the oropharynx; the others were located in the
esophagus. In 70% of cases the malignancies were detected at an early stage.
CONCLUSIONS: Esophageal brush-capsule cytology is a simple noninvasive technique
that has been proven to be useful in the early detection of metachronous and
recurrent neoplasms in the follow-up of patients with previously treated
carcinomas of the ear, nose, and throat.
PMID- 10692210
TI - Molecular biology in cytopathology: current applications and future directions.
AB - The use of molecular techniques in cytopathology has become an accepted and
billable practice for certain applications. Other applications still are in the
developmental or experimental stages but may soon be clinically useful. The
current study provides a review of these techniques including molecular detection
of clonality, in situ hybridization, loss of heterozygosity, and single base
mutation detection. A number of new molecular techniques recently have been
described that may have a dramatic impact on diagnostic pathology. These
techniques, in situ detection of single base mutations and microarray technology,
are introduced and discussed in the context of potential applications to
cytopathology in the future.
PMID- 10692212
TI - Epithelial cells and other cytologic features of pseudomyxoma peritonei in
patients with ovarian and/or appendiceal mucinous neoplasms: a study of 12
patients including 5 men.
AB - BACKGROUND: Pseudomyxoma peritonei (PP) is a rare condition. Cytologic evaluation
of peritoneal fluid often is an initial diagnostic test for possible ovarian
and/or appendiceal primary tumors. Previous studies suggest that patients with PP
who have epithelial cells (ECs) in their peritoneal fluid usually have a less
favorable prognosis than patients with acellular PP. To the authors' knowledge,
few reports of PP in the cytologic literature cite the presence of ECs. METHODS:
Twelve cases of PP diagnosed by cytologic examination at the University of Texas
M. D. Anderson Cancer Center over 15 years were identified. In all cases, primary
tumors were confirmed histologically. All available cytologic smears and cell
block sections were reviewed for cytomorphology, with particular attention given
to the presence of ECs. A correlation between the presence of ECs and patient
outcome also was sought (median follow-up, 26 months). RESULTS: Two patients had
ovarian neoplasms, six patients (one female and five males) had appendiceal
neoplasms, and four patients had synchronous ovarian and appendiceal tumors.
Cytologic features included mucin pools (12 of 12 patients), ECs (11 of 12
patients), mesothelial or mesothelial-like cells (10 of 12 patients), histiocytes
(11 of 12 patients), and fibroblast-like or spindle cells (6 of 12 patients). ECs
were columnar with mucinous features in the majority of cases, and the number of
ECs in each case was variable, ranging from 1+ (rare) to 3+ (many). Of the 11
patients with available follow-up data, 6 had recurrent disease, 4 had persistent
disease, and 1 patient with acellular PP was alive without clinical evidence of
disease after 24 months of follow-up. CONCLUSIONS: Unlike previous PP cytology
reports, the current study frequently identified ECs (92%). Because of the
potential prognostic implication of ECs in patients with PP, a diligent search
for ECs is warranted. Indication of the presence or absence of ECs in the
cytology report may be useful when PP is diagnosed.
PMID- 10692213
TI - Cytology of thymomas: emphasis on morphology and correlation with histologic
subtypes.
AB - BACKGROUND: Aspirates of thymomas are distinguishable from other lesions and fine
needle aspiration (FNA) is a proven method for investigating mediastinal masses.
METHODS: Thirty-four cytology specimens of thymomas from 31 patients were
examined. Corresponding surgical materials were available in 32 cases. Ten cases
were benign and 22 were malignant. Cytologic features of these thymomas were
correlated with various histologic classification systems and with biologic
behavior. Dual epithelial and lymphoid populations and irregular cohesive tissue
fragments of varying proportions of lymphoid and epithelial cells were
characteristic of all aspirates. RESULTS: Using the Lattes-Bernatz
classification, 10 cases predominately were lymphocytic, 3 cases predominately
were epithelial, 3 cases predominately were spindle, 15 cases predominately were
mixed, and 1 case was a thymic carcinoma. In the Muller-Hermelink classification,
3 cases were medullary, 12 were mixed, 8 predominately were cortical, 2 were
cortical, 6 were well differentiated thymic carcinoma, and 1 was a poorly
differentiated thymic carcinoma. In the majority of the cases the epithelial
cells were round to oval. Spindle cells and a mixture of round to oval and
spindle cells also were observed. No cytologic feature was found to correlate
significantly with any classification scheme. Necrosis was present in 5 of the 32
aspirates, most frequently in malignant tumors. Thymomas showing predominately
spindle cells frequently were encapsulated. Tumors with predominantly round to
oval cells or a mixed population behaved more aggressively than those with
spindle cells. Tumors that were well encapsulated and benign clinically tended to
possess benign-appearing nuclei. Among the 22 invasive or malignant lesions, 8
exhibited moderate to marked cytologic atypia and 14 showed little or no atypia.
No atypia was observed in benign tumors. CONCLUSIONS: The presence of cytologic
atypia of epithelial cells may be helpful in predicting aggressiveness. However,
the absence of atypia and necrosis may not imply a benign course. Correlation
with clinical and radiographic findings should be sought.
PMID- 10692214
TI - Cytologic features of proliferative breast disease: a study designed to minimize
sampling error.
AB - BACKGROUND: Assessment of cytologic features that allow accurate classification
of proliferative breast disease has been hampered by sampling errors when fine
needle aspirations have been compared with their corresponding histologic
sections. METHODS: To allow for optimal cytohistologic correlation, 2 smears (1
hematoxylin and eosin-stained and 1 Diff-Quik-stained) were prepared from each of
98 breast biopsies without mass lesions and compared with the corresponding
histologic sections of the scraped area. Each smear was reviewed in a blinded
fashion and assessed for cellularity, background elements, cytoarchitectural
features of cell groups, and nuclear features by 2 reviewers. Smears were then
classified as nonproliferative breast disease (NPBD), proliferative breast
disease without atypia (PBD) or with atypia (PBDA), or DCIS, based on review of
the corresponding histologic sections. RESULTS: When comparing NPBD/PBD (n = 86)
with PBDA/DCIS (n = 12), smears from PBDA/DCIS were significantly (by the Fisher
exact test or Wilcoxon rank sum P values with adjustment for multiple
comparisons) more likely to be cellular; contain single cells and necrosis;
exhibit nuclear overlap and cytoplasmic vacuoles; have large nuclei,
macronucleoli, pleomorphism, clumped chromatin, and hyperchromasia; and were less
likely to have complex cell groups, monolayers, swirling, cohesion, and
myoepithelial cells in epithelial sheets and the smear background. When NPBD (n =
53) and PBD (n = 33) were similarly compared, smears from PBD were more likely to
exhibit larger and more complex cell groups, but they were otherwise similar to
smears from NPBD. CONCLUSIONS: There are many cytologic features that will allow
a distinction of NPBD/PBD from PBDA/DCIS, but relatively few that can aid in
separating NPBD from PBD.
PMID- 10692215
TI - Intranuclear holes (cytoplasmic pseudoinclusions) in parathyroid neoplasms, or
"holes happen".
AB - BACKGROUND: A parathyroid adenoma demonstrating intranuclear holes on aspiration
cytology prompted a review of parathyroid neoplasms to determine the frequency of
this phenomenon. METHODS: Aspiration cytology slides from 30 parathyroid adenomas
and 1 parathyroid carcinoma were reviewed. In addition, histologic slides from
136 parathyroid adenomas and 7 parathyroid carcinomas were reviewed. Twenty-two
cases had both cytologic and histologic slides available for review. The presence
and approximate frequency of intranuclear holes were recorded. RESULTS: On
cytologic smears, intranuclear holes were found in 3 of the 31 cases reviewed (2
adenomas and 1 carcinoma). The holes were frequent in only one adenoma (the index
case) and moderate-rare in the other two cases. Review of tissue slides showed
holes in 9 of 136 adenomas and 3 of 7 carcinomas; 2 adenomas and 2 carcinomas had
frequent holes, whereas the remainder had holes infrequently. CONCLUSIONS:
Intranuclear holes do occur in parathyroid neoplasia, in rare cases with
considerable frequency. When intranuclear holes are observed in aspiration
cytology specimens from the thyroid region, various thyroid and parathyroid
conditions must be considered.
PMID- 10692216
TI - Fine-needle aspiration cytology of bone: accuracy and pitfalls of cytodiagnosis.
AB - BACKGROUND: Fine-needle aspiration cytology has proved to be an accurate, cost
effective, and safe technique for diagnosing inflammatory and neoplastic lesions
at different body sites. Its applicability in bone pathology, however, has been
controversial due to a high percentage of inadequate samples and nonspecific
results in the diagnosis of primary bone lesions. In this study, the diagnostic
accuracy of the technique and its capacity for diagnosing primary bone lesions
were assessed. In addition, the authors analyzed the diagnostic limitations with
focus on specimen adequacy. METHODS: The authors reviewed 314 consecutive fine
needle aspirations of bone from 308 patients. Direct or cytospin smears from
aspirated material were fixed in 95% alcohol and stained by a modified
Papanicolaou technique. Ninety-seven smears (31%) initially were considered
unsatisfactory and excluded from the study. A diagnosis was rendered in 217 cases
(69%), which were classified into 4 categories: primary bone lesions (benign and
malignant) (42%), metastatic bone tumors (37%), suspicious for malignancy (5%),
and negative (16%). RESULTS: The overall accuracy was 95%. Seventy-eight percent
of primary bone lesions were correctly diagnosed by cytology. All cases diagnosed
as metastatic by cytology were correct. The authors encountered difficulties
diagnosing fibro-osseous lesions. Thirteen percent of cases were erroneously
diagnosed as "negative" or "inflammatory conditions." On review, the absence of
adequate cytologic material was noted in all of them. This sampling error could
have been avoided by the presence of an on-site cytopathologist. CONCLUSIONS:
Fine-needle aspiration of bone is a simple, reliable, and accurate diagnostic
technique that can facilitate patient management and preoperative decision-making
and/or avoid unnecessary invasive procedures for patients with primary or
metastatic bone lesions. However, the radiologist, cytopathologist, and
orthopedic surgeon should work together for optimal results. Moreover, a
definitive pathologic diagnosis should not be issued if diagnostic material is
not adequate and/or clinicoradiologic information is incompatible.
PMID- 10692217
TI - Cytologic differential diagnosis among reactive mesothelial cells, malignant
mesothelioma, and adenocarcinoma: utility of combined E-cadherin and calretinin
immunostaining.
AB - BACKGROUND: The differential diagnosis between reactive mesothelial cells (RMs),
malignant mesotheliomas (MMs), and adenocarcinomas (ACs) is often difficult in
cytologic specimens, and the utility of various immunohistochemical markers have
been explored. Because recent immunohistologic studies have suggested that E
cadherin (E-cad) and calretinin (Cal) may be useful markers for epithelial and
mesothelial differentiations, respectively, the authors investigated their
utility in cytologic diagnosis. METHODS: In this retrospective study,
immunostaining was performed on smears retrieved from Papanicolaou-stained slides
of effusions using the labeled streptavidin-biotin method. Sixteen cases of RM, 9
cases of MM, and 52 cases of AC from various sites, including 13 pulmonary
primaries, were examined with primary antibodies against E-cad and Cal. RESULTS:
The positive rates for E-cad and Cal, respectively, were as follows: RM, 0/16
(0%) and 16/16 (100%); MM, 9/9 (100%) and 8/8 (100%); and AC, 45/52 (86.5%) and
0/51 (0%). The E-cad expression by neoplastic cells was strongest in the
intercellular junctions, and poorly differentiated neoplastic cells in the single
cell form showed the weakest expression. CONCLUSIONS: In contrast to the results
of previous immunohistochemical studies, the current study indicates that MMs
constantly express E-cad, whereas RMs lack its expression in cytologic specimens,
which would be useful in the differential diagnosis between the two. On the other
hand, E-cad expression is not reliable for distinguishing AC from MM. The Cal
expression can be a very useful marker for the distinction between AC and the
mesothelial lineage. The combined immunostaining for E-cad and Cal has utility in
differential diagnosis among RM, MM, and AC.
PMID- 10692218
TI - Comparison of the results of immunocytochemical assays for biologic variables on
preoperative fine-needle aspirates and on surgical specimens of primary breast
carcinomas.
AB - BACKGROUND: Fine-needle aspiration biopsy (FNAB) is a well-documented procedure
for the diagnosis and biologic characterization of breast carcinoma. In order to
compare the immunocytochemical expression of biologic parameters on cytology and
on histology, estrogen receptor (ER) and progesterone receptor (PgR) status, p53
protein expression, and Ki67 growth fraction were evaluated on presurgical fine
needle aspirates (FNAs) from breast carcinoma patients and on the corresponding
surgical samples prior to any systemic therapy. METHODS: FNAs were performed on
104 patients with primary breast carcinoma at the time of diagnosis and subjected
to immunocytochemical evaluation of ER, PgR, p53, and Ki67. The same parameters
were immunohistochemically evaluated on the corresponding paraffin embedded
sections. RESULTS: ER, PgR, p53, and Ki67 were evaluable on FNAs and on paired
tissue sections in 100, 97, 68, and 84 cases, respectively. Concordance between
cytology and histology was 89% for ER, 78% for PgR, 79% for p53, and 70% for
Ki67. CONCLUSIONS: The concordance between the results of immunocytochemical
evaluation of ER, PgR, p53, and Ki67, on both cytology and histology, underscores
the reliability of the biologic characterization of breast carcinoma by FNAB.
This approach could be particularly useful in predicting prognosis and response
to treatment in patients who are candidates for neoadjuvant chemotherapy and/or
endocrine therapy.
PMID- 10692219
TI - Utility of liquid-based cytology for cervical carcinoma screening.
PMID- 10692220
TI - Author reply
PMID- 10692221
TI - Multiplex polymerase chain reaction-based analysis of T-cell receptor gamma gene
rearrangements for the determination of T-lymphocyte clonality.
AB - Determination of the frequency of mutations at hprt or other loci in human
lymphocytes provides a useful biomarker for human exposure to mutagens. One
problem, however, is distinguishing between unique mutants and sibling mutants
arising as progeny of an earlier mutant cell. We have developed a multiplex
polymerase chain reaction (PCR)-based method to analyze T-cell receptor (TCR)
gamma gene rearrangements for determination of T-cell clonality in mutational
spectrum analysis. PCR primers for different subgroups of the V gene segment of
the TCR gamma gene were selected at different sites in the TCR gamma gene so that
the size of PCR products could define which V subgroup was involved in rearranged
TCR gamma genes; gamma genes involving different V and J subgroups could be
determined directly by PCR. Mutant T-lymphocytes with rearranged TCR gamma genes
containing the same V and J subgroups were analyzed using PCR-based denaturing
polyacrylamide gel electrophoresis. All of the 161 hprt mutant clones analyzed
contained rearranged TCR gamma genes. Rearrangements among all subgroups of the V
and J gene segments of the TCR gamma gene could be detected. VgammaI and
Jgamma1/2 subgroups were involved in 69 and 71% of rearranged TCR gamma genes,
respectively. This PCR-based analysis of TCR gamma gene rearrangements provides a
simple and comprehensive method for identifying the clonality of mutant T
lymphocytes in human hprt mutant lymphocyte assay and mutational spectrum
analysis.
PMID- 10692222
TI - Phthalates demonstrate genotoxicity on human mucosa of the upper aerodigestive
tract.
AB - Various phthalate compounds are used as softeners and plasticizers in a wide
range of plastic materials. There has been a growing concern regarding a possible
health hazard to humans. The mucosa of the upper aerodigestive tract is the organ
of first contact for the majority of xenobiotics, such as phthalates, entering
the body. Still, there is a lack of information concerning possible
carcinogenicity of phthalates in the upper aerodigestive tract. This motivated us
to investigate their genotoxic effects on human epithelia: human mucosal cells
derived from biopsies harvested during surgery of the oropharynx and the inferior
nasal turbinate, respectively. The alkaline version of the microgel
electrophoresis assay was used to detect single-strand breaks in the DNA
following incubation with dibutylphthalate (DBP) and diisobutylphthalate (DiBP).
DNA damage was induced by both DBP and DiBP in oropharyngeal and nasal mucosa,
though the effect of DiBP was more pronounced than that of DBP. Nasal mucosa
proved to be more sensitive than oropharyngeal epithelia. The results demonstrate
genotoxic effects of phthalates on human mucosal cells of the upper aerodigestive
tract, in contrast to earlier findings in animal models.
PMID- 10692223
TI - Use of catalytic topoisomerase II inhibitors to probe mechanisms of chemical
induced clastogenicity in Chinese hamster V79 cells.
AB - Determination of the clastogenic potential of new chemical entities, particularly
pharmaceuticals, is an important part of the overall safety assessment of such
drugs. It is appreciated that clastogenicity can arise from perturbation of many
different cellular processes distinct from direct DNA/drug interactions. One such
alternative clastogenic process is inhibition of DNA topoisomerase II, during
which process the topoisomerase/DNA/drug ternary complex forms stable DNA double
strand breaks (cleavable complex), which become templates for recombinational,
mutagenic, and chromosomal fragmentation events. Without extensive
experimentation, it is generally not possible to distinguish clastogenicity
arising from direct drug/DNA interaction from that arising from inhibition of
topoisomerase II. In the present investigation, we demonstrate that specific
catalytic inhibitors of DNA topoisomerase II reduce the clastogenicity of
topoisomerase poisons but not that arising via non-topoisomerase-dependent
mechanisms. In particular, it is shown that catalytic topoisomerase II inhibitors
such as chloroquine, sodium azide, and A-74932, as well as certain intercalating
agents such as 9-aminoacridine and ethidium bromide, strongly antagonize the
formation of micronuclei induced by the DNA gyrase inhibitor clinafloxacin and
the antitumor topoisomerase II poison etoposide. These catalytic inhibitors are
also shown to antagonize the clastogenicity of experimental compounds and novel
pharmaceuticals presumed to be DNA intercalating agents by virtue of their
response in a cell-based bleomycin amplification assay. We extend our previous
hypothesis, suggesting that the clastogenicity of some nonstructurally alerting
drugs may be due to an as yet unappreciated propensity for DNA intercalation. It
is further proposed that intercalation-dependent inhibition of DNA topoisomerase
II may be responsible for this clastogenicity and that this may be detected in
intact mammalian cells with the use of catalytic topoisomerase inhibitors.
PMID- 10692224
TI - Oxidative mutagenesis in Escherichia coli strains lacking ROS-scavenging enzymes
and/or 8-oxoguanine defenses.
AB - Escherichia coli strains with different combinations of null mutations in the
katG, katE, sodA, sodB, fpg, and mutY genes were constructed to compare their
spontaneous mutation frequencies and sensitivities to various oxidants with those
of bacteria solely deficient in catalase (katG katE) or cytosolic superoxide
dismutase (sodA sodB) and the parental strain possessing a full complement of
these enzymes. The MutY DNA glycosylase represented the major protection against
the mutagenic consequences of processes associated with normal aerobic
metabolism. Spontaneous mutagenesis in MutY-lacking bacteria was not influenced
by the absence of (A)BC excinuclease or the presence of MucAB proteins, a result
consistent with 8-oxoguanine being a principal premutational lesion. In contrast,
catalase and SOD represented the major protection against the genotoxic
consequences of bursts of oxidative stress caused by reactive-oxygen-generating
compounds. Therefore, only bacteria simultaneously defective in both katG and
katE or sodA and sodB genes were hypersensitive with respect to mutability by
peroxide and superoxide, respectively. These data suggest that oxidative lesions
other than 8-oxoguanine contribute to mutagenesis by hydrogen peroxide and redox
cycling chemicals.
PMID- 10692225
TI - UV-induced mutagenesis of human p53: analysis using a double-selection method in
yeast.
AB - Comparison of the mutation patterns of p53 in human tumors with those of
selectable genes in model systems is a powerful approach to identify potential
etiological factors for specific tumor types. Recently, we validated use of a
yeast assay to permit direct determination of the mutation spectrum induced in
human p53 by carcinogens that would reduce uncertainties inherent in comparing
spectra induced in different target genes. Here, we describe modifications in the
assay designed to facilitate screening for mutants and to permit intracellular
exposure of the gene instead of in vitro treatment. This was accomplished by
introducing growth-based selection for transactivation-deficient p53 mutants into
yeast already possessing red/white colony color selection. This improved model
system was able to detect cells harboring p53 mutations among cells with wild
type p53 at a frequency of 10(-4) or less. Additionally, UV light was used to
verify that the majority of mutagenized cells with the appropriate phenotype on
selective medium contained mutations in p53, not elsewhere in the genome.
Sequence analysis of UV-induced mutations revealed that the nature of the
mutations was similar to those obtained in previous studies of this mutagen. This
system will prove useful in the determination of the ability of environmental
agents to mutate the human p53 gene, and thus may contribute to hazard
identification.
PMID- 10692226
TI - Nitric oxide-induced mutations in the HPRT gene of human lymphoblastoid TK6 cells
and in Salmonella typhimurium.
AB - Characterization of mutations induced by NO in different experimental systems
will facilitate elucidation of mechanisms underlying its genotoxicity. The
mutagenic specificity of NO in human cells is of particular interest in view of
its potential role in inflammation-associated carcinogenesis. We compared
mutagenesis in human lymphoblastoid TK6 cells and in Salmonella typhimurium
induced by exposure to NO delivered into the medium at rates approximating its
production by activated macrophages. Exposure of TK6 cells continuously for 60
min decreased viability by 88%, and survivors exhibited a sixfold increase in
mutant fraction in the hprt gene. Independent mutants were isolated and mutations
characterized by RT-PCR and DNA sequencing. Among a total of 68 mutants analyzed,
RT-PCR products were obtained in 41 (60%), and cDNA sequencing revealed that 26
(63%) of them contained mutations located in the hprt coding region. Base
substitutions were present in 18 mutants, 12 occurring at A:T base pairs. Seven
mutants contained deletions of 1-27 bp and one a 13-bp insertion; the 15
remaining RT-PCR products contained whole-exon deletions, 14 involving single
exons. Six tester strains of S. typhimurium, each containing one of the six
possible point mutations in the target codon of a gene in the histidine
biosynthetic pathway, were similarly treated with NO and induction of mutation
was detected by reversion to histidine auxotrophy. Significant increases were
observed in frequencies of each of the six possible base mutations, with the
highest occurring in G:C --> A:T transitions. The pattern of NO-induced hprt
mutations in TK6 cells was similar to a recently published spectrum in
spontaneous mutants, suggesting that reactive species derived from NO may
contribute to spontaneous mutagenesis of the endogenous hprt gene in human cells.
PMID- 10692227
TI - Mutagenic potential of adenine N(6) adducts of monoepoxide and diolepoxide
derivatives of butadiene.
AB - To determine the biological effects of specific DNA adducts resulting from the
interaction of 1,3-butadiene metabolites with DNA, deoxyoligonucleotides have
been synthesized with four different adducts at the N(6) position of adenine,
centrally located within the human N-ras codon 61. The adducts are those arising
from adduction by either the R or S stereoisomer of the monoepoxide (BDO) or the
(R,R) or (S,S) isomer of the diolepoxide (BDE). The diolepoxide can arise from
partial hydrolysis of the diepoxide (BDO(2)) or from epoxidation of hydrolyzed
monoepoxide. These adducted oligonucleotides were used in in vivo and in vitro
assays designed both to determine their mutagenic potency and to examine specific
interactions with Escherichia coli polymerases. Each adducted oligonucleotide was
ligated into a single-stranded vector M13mp7L2 that was subsequently used to
transfect E. coli. The resulting mutagenic spectrum for these modified DNAs was
stereoisomer specific. Both monoepoxide lesions were nonmutagenic, but the
mutagenic spectra for the modified DNAs containing BDE adducts were stereoisomer
specific. The mutations generated by adducts of the R,R enantiomer of the
diolepoxide were exclusively A --> G, whereas adducts of the S,S enantiomer of
the diolepoxide yielded exclusively A --> C mutations. None of the four
modifications resulted in significant blocks to in vivo phage replication, as
evidenced by no decrease in plaque-forming ability. Consistent with these data,
when each of three purified E. coli polymerases was used to replicate DNAs
containing these adducted deoxyoligonucleotides, the individual polymerases
appeared to be virtually unaffected, such that all lesions were readily bypassed.
Whereas previous animal model studies identified the mutagenic spectrum related
to butadiene exposure, these studies begin to establish the specific lesions
responsible for mutagenesis. This is the first report of stereoselectivity
related to butadiene-induced mutagenesis.
PMID- 10692228
TI - Genetically modified Chinese hamster ovary cells for investigating
sulfotransferase-mediated cytotoxicity and mutation by 2-amino-1-methyl-6-
phenylimidazo[4,5-b]pyridine.
AB - To test the hypothesis that the sulfotransferase gene plays a role in the phase
II bioactivation of PhIP, a heterocyclic amine found in cooked meats, we
transfected the UV5P3 cell line with cDNA plasmids of human aryl
sulfotransferases (HAST1 and HAST3). UV5P3 is a nucleotide excision repair
deficient and P4501A2-expressing CHO cell line that we have previously developed.
Functionally transformed clones were identified by the differential cytotoxicity
(DC) assay that used PhIP as the cytotoxic agent. Two clones designated 5P3H1 and
5P3H3, expressing HAST1 and HAST3, respectively, were chosen for further
characterization. Correct fragment sizes of the sulfotransferase cDNAs were
identified in both cell lines by polymerase chain reaction. Immunoblot analysis
confirmed the expression of the sulfotransferase proteins. The addition of the
sulfotransferase inhibitor DCNP decreased the cytotoxic effects of PhIP in a dose
dependent manner. The increase in cell growth was 6. 5-fold for 5P3H1 and 2.4
fold for 5P3H3, relative to values obtained without DCNP. Based on D(50) values,
the dose that reduced the survival to 50% relative to untreated controls, the
cytotoxic effect of PhIP was increased threefold for 5P3H1 and 1.87-fold for
5P3H3 cell lines over the parental UV5P3 line. There was also a small increase in
the mutation response at the aprt locus. These newly established 5P3H1 and 5P3H3
sulfotransferase-expressing cells provide valuable mechanistic information of the
bioactivation of PhIP and related compounds. Environ. Mol. Mutagen. 35:57-65,
2000. Published 2000 Wiley-Liss, Inc.
PMID- 10692229
TI - Effect of stable integration of the Escherichia coli ada gene on the sensitivity
of Saccharomyces cerevisiae to the toxic and mutagenic effects of alkylating
agents.
PMID- 10692230
TI - New bioactive flavonoids and stilbenes in Cube resin insecticide
PMID- 10692231
TI - Annocherin and (2,4)-cis- and trans-annocherinones, monotetrahydrofuran
annonaceous acetogenins with a C-7 carbonyl group from annona cherimolia seeds
PMID- 10692232
TI - Biased retellings of events yield biased memories.
AB - When people retell events, they take different perspectives for different
audiences and purposes. In four experiments, we examined the effects of this
postevent reorganization of events on memory for the original events. In each
experiment, participants read a story, wrote a biased letter about one of the
story characters, and later remembered the original story. Participants' letters
contained more story details and more elaborations relevant to the purpose of
their retellings. More importantly, the letter perspective affected the amount of
information recalled (Experiments 1, 3, and 4) and the direction of the errors in
recall (Experiments 1 and 3) and recognition (Experiment 2). Selective rehearsal
plays an important role in these bias effects: retelling involves selectively
retrieving and using story information, with consequent differences in memory.
However, biased memory occurred even when the biased letters contained little, if
any, specific information (Experiment 4) or contained the same amount and kinds
of story information as a neutral control condition (Experiment 3). Biased memory
is a consequence of the reorganizing schema guiding the retelling perspective, in
addition to the effects of rehearsing specific information in retelling.
PMID- 10692233
TI - Representation versus process in simplicity of serial pattern completion.
AB - This study deals with the question whether preferred extrapolations of serial
patterns are determined by the extrapolation process or the representation of
serial patterns. Three experiments are reported. The first deals with series of
letters from the alphabet. Each series gave rise to extrapolations with varying
frequencies, and we investigated how well these frequencies are predicted by the
information loads, stemming from three models. The model of Klahr and Wallace
(1970) is mainly concerned with the process of extrapolation. The model of Simon
and Kotovsky (1963) describes both the process and the representation of
extrapolated series. A third model is introduced here that exclusively deals with
the representation of series. The outcome indirectly indicates that the preferred
extrapolation is determined by the simplest representation of a series and not by
the simplest process towards this representation. To strengthen the last
conclusion two experiments are added dealing with bar graph stimuli. They are
designed to experimentally disentangle representation and process complexity. In
the second experiment the task was to judge the complexity of each series after
having extrapolated the series. In the third experiment, subjects had to judge
complexity of extrapolated series without the task to extrapolate the series. The
predictions from the three models make plausible that the complexity judgments of
second experiment reflect the process of extrapolation and the complexity
judgments of the third experiment still reflect the representation of series. The
latter results again support the assumption that the preferred extrapolation is
determined by the simplest representation of a series.
PMID- 10692234
TI - Low-dose IL-2 reduces lymphocyte apoptosis and increases naive CD4 cells in HIV-1
patients treated with HAART.
AB - During HIV disease an increased in vitro apoptosis of peripheral blood
mononuclear cells has been demonstrated. This can be reversed in vitro by
interleukin (IL)-2. Recent trials with highly active antiretroviral therapy
(HAART) and IL-2 in HIV-1-infected patients showed promising immunological and
clinical results. Here we investigated the effects of subcutaneous low-dose IL-2
administration in combination with HAART on in vitro apoptosis and the
relationship between apoptosis, CD4(+) counts, and HIV replication. Twenty-two
asymptomatic HIV patients were randomized for HAART (arm I) and HAART plus IL-2
(arm II). Spontaneous apoptosis was decreased in both arms after 28 weeks of
therapy but the reduction was highly significant only in arm II (P = 0.05 vs P =
0.001). As the percentage of apoptosis decreased, there was a significantly
higher increase of both CD4(+) and CD4(+) naive T cells in arm II vs arm I. HIV
plasma viremia was reduced in all patients after therapy. Our data suggest that
intermittent therapy with low-dose subcutaneous IL-2 in addition to HAART induces
a positive immunomodulation in asymptomatic HIV-infected patients.
PMID- 10692235
TI - Functional subsets within clonally expanded CD8(+) memory T cells in elderly
humans.
AB - With advancing age, healthy humans frequently demonstrate large clonal expansions
of CD8(+) T cells in the peripheral blood, which persist for long periods of time
and appear to be maintained as a population of memory cells. We studied nine
large T cell clones in five elderly individuals. We noted that in most cases the
expanded clones were dominated by cells that did not express CD28, a pivotal
molecule in T cell activation, and these clones proliferated poorly in culture.
However, nearly all of the clonal expansions had CD28(+) fractions and some of
these cells appeared to lose CD28 gene expression with stimulation in culture.
CD28(+) cells demonstrated greater proliferation in both bulk and limiting
dilution cultures compared to CD28(-) cells bearing the same TCR, whereas CD28(-)
cells showed increased perforin expression. Together, these data suggest that
loss of CD28 expression marks functional differentiation to cytotoxic memory
cells within these clonal expansions and likely within CD8(+) memory populations
in general.
PMID- 10692236
TI - Human mast cells express the hyaluronic-acid-binding isoform of CD44 and adhere
to hyaluronic acid.
AB - CD44 is expressed in various isoforms on multiple cell lineages including those
of hematopoietic origin and is believed in part to mediate cell adhesion to
hyaluronic acid. Elevated levels of soluble CD44 (sCD44) have been identified in
the serum of some patients with specific neoplasms. We thus sought to determine
whether human mast cells express functional CD44 and whether sCD44 might be
associated with systemic mast cell disease. Using a standard assay, CD34(+)
derived cultured human mast cells were first demonstrated to adhere to hyaluronic
acid-coated surfaces. Human mast cells were then found by flow cytometry to
express CD44S, but not the v5, v6, v7, and v8 isoforms, and to shed CD44S
following activation induced by PMA or aggregation of FcvarepsilonRI. However,
CD44S was not found to be consistently elevated in serum obtained from patients
with mastocytosis or individuals experiencing anaphylaxis. Thus, human cultured
mast cells express and shed CD44S, which appears to mediate the attachment of
these cells to hyaluronic acid.
PMID- 10692238
TI - Fatal Mycobacterium bovis BCG infection in TNF-LT-alpha-deficient mice.
AB - Neutralization of TNF or disruption of TNF-R1 leads to fatal Mycobacterium bovis
BCG infection. Here we used TNF-LT-alpha-deficient mice to test whether a
complete disruption of TNF and LT-alpha reduces further host resistance to BCG
infection. The bacterial burden especially in the lungs of TNF-LT-alpha-deficient
mice was significantly increased and the mice succumbed to infection between 8
and 10 weeks. In the absence of TNF-LT-alpha the granulomatous response was
severely impaired and delayed. The cells in the granulomas of TNF-LT-alpha
deficient mice expressed low levels of MHC class II and ICAM-1. They contained a
few T cells and F4/80-positive macrophages expressing little iNOS and acid
phosphatase activity. By contrast, the lethal action of endotoxin was
dramatically reduced in BCG-infected TNF-LT-alpha-deficient mice. In summary, in
the absence of TNF-LT-alpha the recruitment and activation of mononuclear cells
in response to BCG infection were significantly delayed and reduced resulting in
immature granulomas allowing uncontrolled fatal infection.
PMID- 10692237
TI - NFAT1 enhances HIV-1 gene expression in primary human CD4 T cells.
AB - Cyclosporin A (CsA) is a potent inhibitor of the NFAT family of transcription
factors that enhance T cell activation. The observation that human
immunodeficiency virus type 1 (HIV-1)-positive transplant recipients have a
reduced HIV-1 viral burden during treatment with CsA suggested that NFAT may play
a direct role in enhancing transcription of the HIV-1 viral genome. Two sets of
NFAT binding sites were identified in the HIV-1 long terminal repeat (LTR)
promoter by in vitro footprinting with full-length recombinant NFAT protein, and
gel shift analysis of nuclear protein from polyclonally activated primary CD4 T
cells revealed specific binding of NFAT1 to the NFkappaB binding sites of the HIV
1 LTR. Activation of primary CD4 T cells transiently transfected with a HIV-1 LTR
luciferase reporter plasmid, lacking the NFAT binding sites in the upstream
putative negative regulatory element but maintaining the NFkappaB/NFAT sites,
demonstrated increased HIV-1 gene expression when cotransfected with a NFAT1
expression vector. Moreover, CsA, FK506, and a dominant-negative NFAT1 protein
independently inhibited HIV-1 LTR promoter activity in CD4 T cells stimulated
with phorbol ester and calcium ionophore. In primary human CD4 T cells, CsA also
inhibited promoter activity directed by multimers of binding sites for NFAT,
while having no effect on NFkappaB multimer-driven promoter activity. Increasing
NFAT1 levels in CD4 T cells transiently transfected with a HIV-1 provirus also
increased p24 protein expression. Thus, NFAT may be a target for prevention of
HIV-1 LTR-directed gene expression in human CD4 T cells.
PMID- 10692239
TI - IL-12-Dependent enhancement of CTL response to weak class I-restricted peptide
immunogens requires coimmunization with T helper cell immunogens.
AB - The effect of in vivo administration of rmIL-12 on the CTL response to
immunization with a weakly immunogenic class I-restricted peptide emulsified in
incomplete Freund's adjuvant was investigated. In the absence of IL-12, peptide
specific CTL responses were significantly greater following coimmunization with
class I-restricted peptide and T helper cell antigens than following immunization
with the class I-restricted peptide alone. IL-12-dependent enhancement of the CTL
response to peptide immunization was demonstrated in the presence of, but not in
the absence of, coimmunization with T helper cell antigen. These findings
indicate that IL-12 enhancement of the CTL response to weak class I-restricted
immunogens is T helper cell dependent. Treatment with rmIL-12 also enhanced the
CTL response to immunization with cDNA encoding both CTL and T helper cell
epitopes. These findings are relevant to the design of vaccines containing tumor
associated class I-restricted peptides currently being tested as an immunotherapy
for cancer patients.
PMID- 10692240
TI - Interleukin-6 release by cultured peripheral blood mononuclear cells inversely
correlates with height velocity, bone age, insulin-like growth factor-I, and
insulin-like growth factor binding protein-3 serum levels in children with
perinatal HIV-1 infection.
AB - Spontaneous and phytohemagglutinin (PHA)-stimulated interleukin (IL)-6 release by
cultured peripheral blood mononuclear cells was related to height velocity, bone
age, insulin-like growth factor-I (IGF-I), and IGF binding protein-3 (IGFBP-3)
serum level standard deviation scores (SDS) of 32 children [aged 91 (median;
range 13-151) months] with human immunodeficiency virus-type 1 (HIV-1) perinatal
infection and severe disease. Spontaneous and PHA-stimulated IL-6 release
inversely correlated with height velocity, bone age, IGF-I, and IGFBP-3 SDS. Ten
children with height velocity SDS = -2, compared to 22 children with height
velocity SDS > -2, showed higher spontaneous and PHA-stimulated IL-6 release and
lower IGF-I and IGFBP-3 SDS (irrespective of CD4-positive T-lymphocyte counts,
viral load, liver disease, or nutrition status). IL-6 overproduction may be a
mechanism of IGF-I and IGFBP-3 down-regulation and impaired linear growth in
children with perinatal HIV-1 infection. Growth-promoting strategies, including
targeted anticytokine treatments, could be devised for such children.
PMID- 10692245
TI - To be, or not to be, that is the question. Apoptosis in human trophoblast.
AB - Apoptosis, the morphology of cell suicide, may result from programmed cell death
or may be a response to exogenous stimuli. Apoptosis can be induced in cultured
trophoblast and can be identified in the trophoblast of placental villi. The
trophoblast regulates maternal-fetal gas, nutrient and waste product exchange;
therefore, the presence of apoptosis in this key cellular interface highlights
the importance of understanding what controls apoptosis in the placenta. In this
review, we describe the signal transduction pathways that trigger apoptosis in
other systems, identify key genetic controls for the process and outline the
final common pathway which effects execution in cells committed to suicide.
Multiplicity, redundancy and cross talk among pathways characterize the surface
membrane signals and exogenous stimuli that trigger apoptosis in other cells. As
each step in the apoptotic process is discussed, we describe what is known about
the step in human placental villi. Recent studies suggest that a further
understanding of receptor-mediated signalling pathways, the Bcl-2 regulators and
the caspases and substrates involved in placental apoptosis will surely provide
insights into both normal placental development and the placental dysfunction
associated with some abnormal pregnancies.
PMID- 10692246
TI - Glucose transporters in the human placenta.
AB - The availability of antibodies and cDNA probes specific for the various members
of the facilitated-diffusion glucose transporter (GLUT) family has enabled
researchers to obtain a much clearer picture of the mechanisms for placental
uptake and transplacental transport of glucose. This review examines studies of
human placental glucose transport with the aim of providing a model which
describes the transporter isoforms present in the placenta, their cellular
localization and functional significance. The GLUT1 glucose transporter, present
on both the microvillous and basal membranes of the syncytial barrier, is the
primary isoform involved in the transplacental movement of glucose. Although
GLUT3 mRNA is widely distributed, GLUT3 protein is localized to the arterial
component of the vascular endothelium, where it may play a role in enhancing
transplacental glucose transport. This data is in contrast to the situation in
other mammalian species, such as the mouse, rat and sheep, where GLUT3 protein is
not only present in those epithelial cells which carry out transplacental
transport but becomes an increasingly prominent isoform as gestation progresses.
The asymmetric distribution of GLUT1 in the human syncytiotrophoblast
(microvillous>basal) means that basal GLUT1 acts as the rate limiting step in
transplacental transfer. Changes in basal GLUT1 therefore have the potential to
cause alterations in transplacental transport of glucose. Although there appear
to be no changes in syncytial GLUT1 expression in intrauterine growth
retardation, in diabetic pregnancies increases in basal GLUT1 expression and
activity have been observed, with significant consequences for the maternal-fetal
flux of glucose. Little is known of glucose transporter regulation in the
placenta save for the effects of hyper- and hypoglycemia. GLUT1 expression and
activity appear to be inversely related to extracellular glucose concentration,
however within the physiological range, GLUT1 expression is relatively refractory
to glucose concentration. Information is still needed on gestational development,
on the expression and activity in well-defined conditions of intrauterine growth
retardation, on the mechanisms and consequences of the changes observed in
diabetic pregnancy and on the role of external agents other than glucose in
regulating placental glucose transport.
PMID- 10692247
TI - Expression of endothelial nitric oxide synthase by extravillous trophoblast cells
in the human placenta.
AB - Previous reports have documented the expression of endothelial nitric oxide
synthase (eNOS) expression by the syncytiotrophoblast layer of the villus in the
human placenta. In contrast, the underlying villous cytotrophoblast cells do not
express the enzyme. Because extravillous cytotrophoblasts have not been as
extensively investigated, our objective was to test whether these cells express
eNOS. Using both a mouse monoclonal and a rabbit polyclonal antibody, we
demonstrated immunoreactive eNOS in trophoblast cell columns emanating from
anchoring villi in second trimester placentae. Cytokeratin positive trophoblast
cells lying beneath remnant anchoring villi, lining decidual blood vessels and
scattered throughout the basal plate of normal term and pre-eclamptic placentae
also expressed immunoreactive eNOS. By Western analysis, the monoclonal and
polyclonal antibodies were shown to be absolutely and relatively specific for
eNOS, respectively. The finding of immunoreactive eNOS expression by extravillous
trophoblast cells was substantiated by in situ hybridization. Using riboprobes
generated from a bovine eNOS cDNA, we demonstrated specific hybridization in the
endothelium of blood vessels in the umbilical cord, thus validating the in situ
hybridization methodology, as well as specific hybridization in the extravillous
trophoblast cells of the basal plate in normal term placenta. In conclusion,
several different populations of extravillous trophoblast cells in the basal
plate of the human placenta express eNOS.
PMID- 10692248
TI - Human placenta, chorion, amnion and decidua express different variants of
corticotropin-releasing factor receptor messenger RNA.
AB - Human placenta is a major source of corticotropin-releasing factor (CRF), and
local effects of CRF in fetal membranes and placenta have been shown, i.e.,
adrenocorticotropic hormone (ACTH) and oxytocin release from cultured placental
cells, as well as prostaglandin release from amnion, chorion and decidua. Two
distinct CRF receptors (CRF-R1 and CRF-R2) have been characterized: CRF-R1
consists of two isoforms (CRF-R1alpha and CRF-R1beta) while CRF-R2 has at least
three different splice variants (CRF-R2alpha, CRF-R2beta and CRF-R2gamma). To
date, CRF-R1 receptor has been identified in human placenta and in pregnant
myometrium, while no evidence for placental CRF-R2 receptor isoforms has been
provided. The present study investigated whether the different isoforms of CRF-R1
and CRF-R2 receptor mRNA are expressed in fetal membranes and placenta. Tissues
were collected after spontaneous vaginal delivery (38-40 weeks) or elective
caesarean section (39-41 weeks). The gene expression of CRF receptors was first
studied by reverse transcriptase-polymerase chain reaction (RT-PCR), and the
presence of CRF-R1alpha, but not of CRF-R1beta, in human placental trophoblast,
amnion/chorion and decidua was shown. In addition, among the three CRF-R2 splice
variants, only CRF-R2beta mRNA was expressed by trophoblast and fetal membranes.
By using in situ hybridization, CRF-R1 and CRF-R2 probes positively hybridized
trophoblast and related membranes. CRF-R1 was localized in the
syncytiotrophoblast cells, chorionic trophoblast and decidua with a small amount
in the amnion. CRF-R2 probe mainly hybridized syncytiotrophoblast cells, but
cytotrophoblast also contained discreet amounts of CRF-R2 mRNA signal. The CRF-R2
hybridization signal was also observed within the structure of the villi (blood
vessels), chorionic trophoblast and decidual cells, but it was faint or absent in
the amniotic epithelium. There was no significant difference in the distribution
of CRF-R1 or CRF-R2 mRNA signal between placentas collected from vaginal delivery
or caesarean section. The evidence that intrauterine tissues differently express
CRF-R1alpha and CRF-R2beta supports possible different local roles of CRF and
related peptides into intrauterine tissues during pregnancy.
PMID- 10692249
TI - Activin A exerts both pro- and anti-inflammatory effects on human term
gestational tissues.
AB - There is a growing appreciation of the importance of activin as a modulator of
immune function. The aim of the present study was to determine whether activin A
exerts any effects on cytokine and prostaglandin (PG) production by the tissues
of pregnancy. Explant cultures were established for amnion, choriodecidual and
placental tissues derived from pregnancies delivered at term by Caesarean section
(n=5 placentae). Explants were treated with activin A (0.5, 5 and 50 ng/ml) in
serum-free Ham's F12/DME media for 24 h (n=3-4 replicates). Production rates of
interleukin (IL)-1beta, IL-6, IL-8, tumour necrosis factor-alpha (TNF-alpha) and
PGE(2)were determined using immunoassay. Differences between treatment groups
were analysed by ANOVA followed by Dunnett's test;P< 0.05 was considered to be
significant. Amnion IL-6 production exhibited biphasic responses to activin A: at
5 ng/ml activin A, IL-6 production was significantly stimulated (to 246+/-74.6
per cent of control (mean+/-sem), while at 50 ng/ml it was significantly
inhibited (to 46+/-7.4 per cent of control). IL-8 and PGE(2)production by amnion
showed significant responses to activin A that were similar to those of IL-6. No
significant effects of activin A were observed on choriodecidual and placental IL
6, IL-8 and PGE(2)production. However, TNF-alpha production was significantly
inhibited by 50 ng/ml activin A in both choriodecidual and placental explants (to
43+/-9.7 per cent and 51+/-6.7 per cent of control, respectively). Placental IL
1beta production was not altered by treatment with activin A at any
concentration. These findings support the concept of activin as an immune
modulator in tissues of pregnancy.
PMID- 10692250
TI - Myofibroblast differentiation in the connective tissues of the amnion and chorion
of term human fetal membranes-implications for fetal membrane rupture and labour.
AB - An area of the fetal membranes, within the rupture tear after spontaneous
delivery at term, exhibits altered morphology compared to more distal sites. It
is characterized by marked swelling of the amniotic and chorionic connective
tissue layers, consistent with structural weakness, and a marked reduction of the
thickness of both the cytotrophoblast and decidual layers. These features, albeit
less extreme, have been identified in fetal membranes in the lower uterine pole
in patients prior to labour. In this study of pre-labour, labour-affected and
post-labour term fetal membranes, we report that these regions are associated
with an alteration in the phenotype of the vimentin positive mesenchymal cell
population of the chorionic connective tissue reticular layer, and are consistent
with myofibroblastic differentiation, i.e. alpha-smooth muscle actin (alpha-sma)
expression. In the reticular layer of the lower uterine pole biopsies in the
labour-affected group the numbers and densities of alpha-sma immunoreactive
positive cells were 17-fold (P=0.04) and 8.5-fold (P=0.02) higher than in mid
zone biopsies. After delivery, in rupture line biopsies the numbers and densities
were 50-fold (P=0. 002) and 36-fold (P=0.003) higher compared to mid zone
biopsies. The percentage of the vimentin positive population positive for alpha
sma was 2-5 per cent in mid-zone biopsies compared to 49 per cent (P=0.03) in the
labour-affected 'cervical' biopsies and 69 per cent (P=0.05) in the rupture line
biopsies. Within the tear sites, alpha-sma positive cells were also detected
within the fibroblastic layer of the amniotic connective tissue. Although there
was no significant difference between the numbers and density of alpha-sma cells
in the reticular layers between mid and lower uterine pole biopsies in the pre
labour group, in a proportion of patients the biopsies were similar to labour
affected biopsies indicating that this alteration occurs prior to clinically
apparent labour in these patients. The incidence of alpha-sma positive cells in
the reticular layer correlated with morphological changes within the fetal
membranes, for example thickness of reticular (r(2)=0.349, P=0.0006) and amniotic
connective tissue layers (r(2)=0.389, P=0.0002). This suggests that cellular
activities associated with myofibroblastic differentiation in the reticular layer
of the chorion may be associated with the observed connective tissue changes,
fetal membrane rupture and labour.
PMID- 10692251
TI - The roles of the cyclo-oxygenases types one and two in prostaglandin synthesis in
human fetal membranes at term.
AB - The aim of this study was to determine the relative contributions of cyclo
oxygenase (COX) types 1 and 2 to prostaglandin synthesis at term. METHODS: Fetal
membranes were collected from 6 pregnancies after elective caesarean section at
term, prior to labour. The presence of COX-1 and COX-2 protein was determined
using Western analysis. The relative contributions of the two isoforms of COX to
prostaglandin synthesis were determined by incubation of fetal membrane discs
with either a COX-2 selective inhibitor, SC236, or a COX-1 selective inhibitor,
SC560, and measurement of prostaglandin release during 24 h using enzyme-linked
immuno-sorbent assay (ELISA). RESULTS: Both COX-1 and COX-2 protein were
demonstrated in amnion and chorion-decidua. The COX-2 selective inhibitor, SC
236, significantly reduced prostaglandin synthesis, both in its COX-2 specific
and higher, non-specific concentration ranges. The COX-1 selective inhibitor, SC
560, had no effect upon prostaglandin synthesis in its COX-1 specific
concentration range, but did significantly reduce prostaglandin synthesis at
higher, non-selective concentrations. CONCLUSIONS: Fetal membranes contain both
COX-1 and COX-2 at term, but only COX-2 contributes towards prostaglandin
synthesis. COX-2 selective NSAI drugs will be as effective as non-selective
agents in inhibition of fetal membrane prostaglandin synthesis and may represent
a new strategy for tocolysis.
PMID- 10692252
TI - Expression of the p53 gene and apoptosis in gestational trophoblastic disease.
AB - In order to understand the involvement of the p53 tumour suppressor gene in the
pathogenesis of gestational trophoblastic disease (GTD), we investigated its
genetic status, protein expression and its role in apoptosis in samples of
complete and partial hydatidiform mole as compared with those of normal placenta.
Direct sequencing of polymerase chain reaction (PCR) products of the coding and
non-coding regions of the p53 gene demonstrated no mutations in any of the
studied samples. Immunohistochemical studies revealed increased expression of the
p53 protein predominantly in the nuclei of villous cytotrophoblasts. This over
expression of p53 was found in all samples of complete mole, in 50 per cent of
partial mole samples and in about 30 per cent of normal placenta cases, although
no significant difference in the staining intensity and pattern was observed. An
in situ detection of DNA nicking (TUNEL) staining, demonstrating apoptosis, was
also detected predominantly in villous cytotrophoblasts and in stromal areas. The
per centage of apoptotic cells in all studied samples, determined by flow
cytometry, demonstrated a significant increase in apoptotic cells in samples of
complete and partial hydatidiform mole compared with those of normal placenta (P<
0.0003 and P< 0.004, respectively). In conclusion, the current study may provide
a possible explanation to the pathogenesis of GTD, probably associated with
extensive p53-dependent apoptosis to modulate excessive trophoblastic
proliferation.
PMID- 10692253
TI - Expression of aminopeptidase A in human gestational choriocarcinoma cell lines
and tissues.
AB - Aminopeptidase A (AP-A), a cell-surface metallopeptidase hydrolyzing peptide with
N-terminal acidic residues, has been proved to be identical to the B cell
differentiation antigen BP-1 and to the kidney differentiation antigen gp160,
suggesting recognition of AP-A as a differentiation-related marker on certain
normal and transformed cells. AP-A has also been purified from human placenta and
been shown to be localized in the trophoblasts. In the present study, we examined
the expression and enzymatic activity of AP-A in human gestational
choriocarcinoma, a neoplastic transformant from trophoblasts which comprises a
heterogenous population of trophoblastic cells in different stages of
differentiation. Flow cytometry and immunoblot analysis demonstrated that AP-A
was expressed in five choriocarcinoma cell lines which were secreting low or
moderate levels of human chorionic gonadotropin (hCG), while two high hCG
secreting cell lines lacked AP-A expression. The AP-A enzymatic activity
correlated with cell-surface levels of AP-A and was abrogated by amastatin, an
inhibitor of AP-A. Immunohistochemical analysis revealed that AP-A was present in
seven of eight choriocarcinoma tissues and was localized on the cell membrane of
cytotrophoblastic choriocarcinoma cells, but not on cells with
syncytiotrophoblast-like features. These results demonstrate that AP-A is
expressed on most choriocarcinomas and its expression is restricted to low hCG
secreting, cytotrophoblastic cells and down-regulated as a function of cell
differentiation, suggesting an involvement of AP-A in the
differentiation/maturation process of neoplastic trophoblasts.
PMID- 10692254
TI - The cellular mechanism by which the human endogenous retrovirus ERV-3 env gene
affects proliferation and differentiation in a human placental trophoblast model,
BeWo.
AB - The env region of the human endogenous retrovirus ERV-3 is expressed during
differentiation of trophoblast and the choriocarcinoma BeWo. Stable transfectants
with ERV-3 env exhibit most aspects of trophoblast differentiation, including
inhibition of cell proliferation, changes in cell morphology, and increased
production of beta-hCG mRNA. In this study, the cellular mechanism of induction
of BeWo cell differentiation by ERV-3 env was investigated. In BeWo cells stably
transfected with ERV-3 env, the production of beta-hCG mRNA and hCG protein was
increased. Intracellular cAMP level was markedly increased over that of vector
transfected cells. The effect on beta-hCG protein production was inhibited by
H89, a protein kinase A (PKA) inhibitor, while protein kinase C (PKC) and protein
tyrosine kinase (PTK) inhibitors had no effect. The expression of a major cell
cycle promoter, cyclin B, was markedly reduced while expression of p21, a
negative regulator of the cell cycle, was up-regulated. Inhibition of ERV-3 env
induced hCG production with H89 had no significant effect on cell growth when
compared with cells transfected with vector alone.
PMID- 10692255
TI - The molar vesicle fluid contains the beta-core fragment of human chorionic
gonadotropin.
AB - The human chorionic gonadotropin (hCG) beta-core fragment (beta-CF) is a major
molecular form of hCG beta subunit (hCGbeta) immunoreactivity in the urine of
pregnant women and patients with trophoblastic disease. The majority of evidence
supports the fact that the beta-CF is a degradative product of intact hCG and
free hCGbeta in the kidneys. We found a beta-CF-like substance in the fluid of
molar vesicles from a patient with complete hydatidiform mole. The molar fluid
beta-CF (mbeta-CF) was indistinguishable from the beta-CF in the patient's urine
(ubeta-CF) by immunoreactivity and by elution profile on gel chromatography. The
binding study to lectins, however, showed that mbeta-CF contains a carbohydrate
moiety that differs from that of ubeta-CF. Immunohistochemistry with anti-beta-CF
antibody demonstrated a strong immunoreactivity in a large number of macrophages
in the molar villous stroma. In vitro incubation of intact hCG with peritoneal
macrophages showed a slow increase of intact hCG in the cell cytosol with the
appearance of beta-CF-like substance in the cell supernatant. In conclusion, the
source of beta-CF in molar fluid is likely to be macrophages existing in the
villous stroma. Thus macrophages may ingest intact hCG and act as a local
regulator of gonadotropic hormones.
PMID- 10692256
TI - Ontogeny of aquaporins 1 and 3 in ovine placenta and fetal membranes.
AB - A sensitive and highly reproducible method has been used to show that Aquaporin 3
(AQP(3)) mRNA is present in the ovine placenta and chorion from at least 60 days
of gestation (term=145-150d) with levels increasing substantially (>16 fold) at
100 days, and remaining constant thereafter. By immuno- and hybridization
histochemistry, the epithelial cells expressing AQP(3)were found to be the
trophoblast cells. Some AQP(3)was expressed in fibroblasts of the amnion and
allantois but none was expressed in the epithelia of these membranes. AQP(1)was
expressed in endothelial cells of fetal and maternal blood vessels but not in any
epithelial cell of the ovine placenta and fetal membranes. The level of
AQP(3)expression is consistent with known ovine placental permeabilities to
water, glycerol and urea.
PMID- 10692257
TI - Relationship between nutritionally-mediated placental growth restriction and
fetal growth, body composition and endocrine status during late gestation in
adolescent sheep.
AB - The aim was to investigate the consequences of nutritionally-mediated placental
growth restriction on fetal organ growth, conformation, body composition and
endocrine status during late gestation. Embryos recovered from superovulated
adult ewes inseminated by a single sire were transferred in singleton to the
uterus of peripubertal adolescent recipients. Post-transfer, adolescent dams were
offered a high (H) or moderate (M) level of a complete diet to promote rapid or
moderate maternal growth rates, respectively (n=7 per group). After day 100 of
gestation the feed intake of the M dams was adjusted weekly to maintain body
condition score. Liveweight gain during the first 100 days of gestation was 301+/
24 and 90+/-4.6 g/day for the H and M groups, respectively. Maternal plasma
concentrations of insulin, IGF-I and urea were significantly higher and non
esterified fatty acid concentrations significantly lower in H compared with M
dams prior to slaughter on day 128 of gestation. At this stage of gestation,
total placentome weight was 50 per cent lower in H compared with M groups (P<
0.001) and was associated with a 37 per cent reduction in fetal weight (P< 0.01).
All variables of fetal conformation and absolute fetal organ weights, with the
exception of the adrenal glands, were lower (P< 0. 05) in the fetuses from H
intake dams. However, relative fetal organ weights expressed as g/kg fetal body
weight, with the exception of the gut, were not influenced by maternal dietary
intake. Furthermore, fetal weight but not maternal nutritional group were
predictive of individual organ weight for all organs dissected. Together these
results imply that growth restriction in the fetuses derived from H intake dams
was largely symmetrical. Fetal plasma concentrations of insulin, IGF-I and
glucose were attenuated (P< 0.05) in fetuses from H compared with M groups. The
lower fetal body weight in the former group was associated with a reduction in
absolute but not relative crude protein (P< 0.01) and fat content (P< 0.05).
Total fetal liver glycogen content but not concentration was (P< 0.05) reduced in
H versus M groups. The lower mass of both the placenta and fetal liver was due to
a reduction in cell number rather than an alteration in cell size. Thus, over
nourishing adolescent sheep is associated with a major restriction in placental
growth which mediates a gradual slowing of fetal growth during the final third of
pregnancy.
PMID- 10692258
TI - Transfer and metabolism of prostaglandin E(2)in the dual perfused human placenta.
AB - Prostaglandins (PGs) are potent paracrine hormones that are important for the
control of several functions in the uterus and fetus during pregnancy and
parturition. PGs are rapidly metabolized to inactive metabolites by prostaglandin
dehydrogenase (PGDH). However, the regulation of transfer and metabolism of PGs
across the placenta is not well understood. This study used an in vitro dual
perfused human placental cotyledon preparation to examine the production of the
potent vasoactive and myometrial stimulants PGE(2)and PGF(2alpha), transfer of
PGs from the maternal to the fetal circulation and the metabolism of PGs by PGDH.
Secretion of PGE(2)was greater into the fetal compared to the maternal
circulation. PGE(2)output was higher than PGF(2alpha)and concentrations of
PGE(2)and PGF(2alpha)metabolites (PGEM and PGFM) were greater in both fetal and
maternal outputs when compared to the primary prostaglandins. Infusion of
PGE(2)into the maternal circulation did not result in increased PGE(2)efflux but
PGEM was output was increased, demonstrating a rapid and efficient metabolism by
the placenta. There was no significant transfer of PGE(2)across to the fetal
circulation, although there was some transfer but in the form of inactivated
PGEM. There was no significant interconversion of PGE(2)to PGF(2alpha)by the 9
keto-reductase pathway. Expression of PGDH as detected by immunoblot was high in
placenta. This PGDH was localized throughout the syncytiotrophoblast at the fetal
maternal interface and also in extravillous trophoblast cells. The presence of
PGDH at this site acts to stabilize output of primary PG from the placenta and
also as a barrier preventing transfer to the fetal circulation, resulting in the
separation of PG homeostasis in the fetus and mother.
PMID- 10692259
TI - Enhanced expression of intercellular adhesion molecule-1 (ICAM-1) in amnion with
term and preterm labour.
AB - To evaluate the association between intercellular adhesion molecule-1 (ICAM-1) in
the amnion and preterm labour and delivery, we have assessed ICAM-1 mRNA
abundance by Northern analysis and protein levels by enzyme-linked immunosorbent
assay (ELISA), in samples of this tissue after term and preterm delivery. The
median ICAM-1 mRNA expression following preterm delivery (PTD, n=30) was 24 times
greater (P< 0.05) than following elective caesarean section prior to labour at
term (CST, n=14). ICAM-1 expression following vaginal delivery after spontaneous
labour at term (SLT, n=11) was seven times greater than in the CST group (P<
0.05). The concentration of ICAM-1 protein in the PTD samples (n=31) was four
fold greater than (P< 0.05) in CST (n=14). It was also three-fold greater than in
the SLT (n=15) samples (P< 0.05). The results were substantially the same when a
preterm spontaneous labour group (PTL) (n=26), exclusive of deliveries
complicated by pre-eclampsia (n=1) or intrauterine growth restriction (n=3), was
compared to the CST and SLT groups. The ICAM-1 mRNA expression did not differ
significantly (P=0.93) between PTL with (n=12) or without (n=14) indicators of
intrauterine infection. The results were similar when ICAM-1 protein
concentrations were compared (P=0.43) between these two groups. These findings
indicate that ICAM-1 is expressed by the human amnion and that this expression is
elevated with preterm labour and delivery.
PMID- 10692260
TI - The human placenta is encircled by a ring of smooth muscle cells.
AB - The marginal zone of the human term placenta was studied by transmission electron
microscopy and immunohistochemistry using antibodies against cytoskeletal
filaments, extracellular matrix molecules and endothelial markers. The marginal
sinus of the intervillous space is separated from the chorionic and basal plates
by a layer of cells expressing vimentin, desmin, alpha- and gamma-smooth muscle
actins, and smooth muscle myosin. Also ultrastructurally, these cells share all
features with smooth muscle cells. This muscular ring is continuous with the
media of uteroplacental veins entering the marginal sinus. In the basal plate the
muscle cells may extend far into the central parts of the placenta. The muscular
ring is separated from the intervillous space by a layer of endothelial cells.
They are continuous with the maternal endothelium of the marginal uteroplacental
veins. Moreover this endothelium covers neighbouring parts of the chorionic and
basal plates, locally extending to the surfaces of large stem villi. The data
suggest (1) that the marginal zone of the intervillous space ('marginal sinus')
represents the dilated and merged parts of uteroplacental veins and (2) that
lateral growth of the human placenta partly takes place by expansion into the
uteroplacental veins. The functional importance of this muscular ring remains
unknown.
PMID- 10692261
TI - The effect of oxytocin, prostaglandin E2 and acetylsalicylic acid on flow
distribution and on the transfer of alanine, glucose and water in isolated
perfused guinea pig placentae.
AB - The influence of oxytocin (OXY), sulproston (SUL) and acetylsalicylic acid (ASA)
on L-alanine- (ALA), D-glucose- (GLU) or water- (H(2)O) uptake (maternal side) in
the isolated perfused guinea pig placenta was investigated. Uptake was measured
with a single injection, paired tracer dilution method. 'T50' values were derived
from venous concentration curves (extracellular marker) as the distance (sec)
between two concentration values at 50 per cent of peak concentration. T50 values
were regarded to reflect the change of flow distribution on the maternal side. On
average, there was a significant apparent inhibition of GLU uptake (by 27.2 per
cent from control values) by OXY as well as of ALA uptake by OXY (26. 0 per
cent), by ASA (56.6 per cent), and by SUL (56.7 per cent). The respective mean
T50 values decreased significantly in the above groups by 15.9 per cent, 18.7 per
cent (ns), 42.2 per cent and 56.7 per cent. However, it was not possible to
generate dose-response curves whereas significant correlations of uptake values
with T50 values were found. There was no dose-response relationship between T50
values and OXY or ASA concentrations but decreased mean T50 values were found.
For SUL a weak correlation of T50 and SUL concentration was found. The r -value
of GLU uptake and T50 was 0.57, for H(2)O uptake this value was 0.70, for ALA
uptake the r -values were 0.51 (OXY), 0.35 (SUL) and 0.31 (ASA). Correlation of
uptake and concentrations were not significant. We conclude that the 'inhibitory'
effects of OXY, ASA and probably SUL on placental transfer are unspecific and the
consequence of flow shifts from the placental exchange area to the uterine
muscle.
PMID- 10692262
TI - Advanced glycation end products: a Nephrologist's perspective.
AB - Advanced glycation end products (AGEs) are a heterogeneous group of molecules
that accumulate in plasma and tissues with advancing age, diabetes, and renal
failure. There is emerging evidence that AGEs are potential uremic toxins and may
have a role in the pathogenesis of vascular and renal complications associated
with diabetes and aging. AGEs are formed when a carbonyl of a reducing sugar
condenses with a reactive amino group in target protein. These toxic molecules
interact with specific receptors and elicit pleiotropic responses. AGEs
accelerate atherosclerosis through cross-linking of proteins, modification of
matrix components, platelet aggregation, defective vascular relaxation, and
abnormal lipoprotein metabolism. In vivo and in vitro studies indicate that AGEs
have a vital role in the pathogenesis of diabetic nephropathy and the progression
of renal failure. The complications of normal aging, such as loss of renal
function, Alzheimer's disease, skin changes, and cataracts, may also be mediated
by progressive glycation of long-lived proteins. AGEs accumulate in renal failure
as a result of decreased excretion and increased generation resulting from
oxidative and carbonyl stress of uremia. AGE-modified beta(2)-microglobulin is
the principal pathogenic component of dialysis-related amyloidosis in patients
undergoing dialysis. Available dialytic modalities are not capable of normalizing
AGE levels in patients with end-stage renal disease. A number of reports
indicated that restoration of euglycemia with islet-cell transplantation
normalized and prevented further glycosylation of proteins. Aminoguanidine (AGN),
a nucleophilic compound, not only decreases the formation of AGEs but also
inhibits their action. A number of studies have shown that treatment with AGN
improves neuropathy and delays the onset of retinopathy and nephropathy. N
Phenacylthiazolium bromide is a prototype AGE cross-link breaker that reacts with
and can cleave covalent AGE-derived protein cross-links. Thus, there is an
exciting possibility that the complications of diabetes, uremia, and aging may be
prevented with these novel agents.
PMID- 10692263
TI - ACE inhibition improves glomerular size selectivity in patients with idiopathic
membranous nephropathy and persistent nephrotic syndrome.
AB - Patients with idiopathic membranous nephropathy (IMN) and persistent nephrotic
range proteinuria are at risk for progression to end-stage renal failure. Whether
angiotensin-converting enzyme (ACE) inhibitors are also renoprotective in these
patients remains elusive. In 14 patients with IMN (patients) and persistent
proteinuria (protein > 3 g/24 h for >6 months), we studied mean arterial pressure
(MAP), urinary protein excretion, glomerular filtration rate (GFR), renal plasma
flow (RPF), and albumin and neutral dextran fractional clearance after 2 months
washout from previous antihypertensive treatment (basal), after 2 months of
enalapril (2.5 to 20 mg/d) therapy (posttreatment), and 2 months after enalapril
withdrawal (recovery). MAP, proteinuria, and GFR were also measured at the same
time points in 6 patients with IMN and persistent overt proteinuria maintained on
conventional treatment throughout the study period (controls). Basal MAP,
proteinuria, and GFR were similar in the two study groups. However, in patients
at the end of the treatment period, MAP (posttreatment, 99.6 +/- 11.2 versus
basal, 103.3 +/- 12.1 mm Hg; P < 0.05), proteinuria (posttreatment protein, 5.0
+/- 2.9 versus basal, 7.1 +/- 4.9 g/24 h; P < 0.05), albumin fractional clearance
(posttreatment median, 1.7 x 10(-3); range, 0.2 to 22.7 x 10(-3) versus basal
median, 4.1 x 10(-3); range, 0.4 to 22. 1 x 10(-3); P < 0.05), and fractional
clearance of largest neutral dextrans (radii from 62 to 66 A) were significantly
less than basal values. At recovery, MAP significantly increased to 106.6 +/-
11.7 mm Hg (P < 0.001 versus enalapril), but all other parameters remained less
than basal values. GFR and RPF were similar at each evaluation. Changes in
proteinuria after treatment withdrawal positively correlated (r = 0.72; P < 0.01)
with baseline GFR. Theoretical analysis of dextran-sieving data indicated that
ACE inhibitor treatment significantly improved glomerular membrane size-selective
dysfunction. This effect persisted more than 2 months after treatment withdrawal.
No patient had symptomatic hypotension, acute renal function deterioration, or
hyperkalemia during enalapril treatment. Thus, in patients with IMN and long-term
nephrotic syndrome, ACE inhibitor treatment, but not conventional therapy,
improves glomerular barrier size selectivity. The antiproteinuric effect of ACE
inhibition is long lasting, especially in patients with more severe renal
insufficiency. This is the premise of a long-term renoprotective effect that may
limit the need for treatment with more toxic drugs.
PMID- 10692264
TI - Outcome of IgA nephropathy in adults graded by chronic histological lesions.
AB - This prognostic study of primary immunoglobulin A (IgA) nephropathy focused on
chronic irreversible glomerular sclerosis and interstitial fibrosis, based on the
premise that this disease is characterized by a protracted and, for many,
progressive course. We used a chronicity-based histological grading system to
assess the biopsy specimens of 126 adults with IgA nephropathy over a median
follow-up of 10 years. Our grading system included a glomerular grading (GG) of 1
to 3 based on the extent of glomerular sclerosis, a tubulointerstitial grading
(TIG) of 1 to 3 based on the degree of tubular loss or interstitial fibrosis, and
the evaluation of hyaline arteriolosclerosis (HA). These three histological
parameters were correlated with each other and with serum creatinine level,
degree of proteinuria, and blood pressure at the time of renal biopsy. Univariate
analysis showed that these three histological and three clinical parameters were
significantly correlated with renal survival. By multivariate analysis using the
Cox regression model, GG, serum creatinine level, and degree of proteinuria
represented independent prognostic factors of renal survival. For a subset of
patients at a relatively early stage of disease with a serum creatinine level
less than 130 micromol/L at the time of biopsy, all three histological features
and degree of proteinuria were significantly correlated with renal survival, and
GG was the only independent prognostic factor for renal outcome. This study shows
that glomerular sclerosis represents the most important prognostic factor in
adult patients with primary IgA nephropathy and has a strong predictive value.
Our chronicity-based histological grading system not only correlates well with
the natural history of IgA nephropathy but is also reproducible and relatively
simple to apply.
PMID- 10692265
TI - Complement activation through the lectin pathway in patients with Henoch
Schonlein purpura nephritis.
AB - Henoch-Schonlein purpura nephritis (HSPN) is considered a form of systemic
vasculitis of the small blood vessels with immune pathogenesis. In this disorder,
the complement system is recognized as an important mechanism of glomerular
injury. The aim of this study is to determine whether the lectin pathway, a novel
pathway of complement activation, is related to the pathogenesis of HSPN. Renal
biopsy material from 10 patients with HSPN was studied immunohistochemically and
examined for a clinicopathologic correlation. Serum levels of complement
components, including mannose-binding lectin (MBL), and plasma levels of
complement activation products were also evaluated in these patients and compared
with levels in patients with immunoglobulin A (IgA) nephropathy or mesangial
proliferative glomerulonephritis (GN) without IgA deposition (non-IgA GN).
Glomerular deposition of components of the pathway, MBL and MBL-associated serine
protease (MASP-1), as well as C3b/C3c, C5b-9, and C4-binding protein (C4-bp), was
detected in 8 of 10 patients. Although no significant correlation was found
between glomerular deposition of MBL/MASP-1 and histological or clinical
findings, the biopsies on all patients with MBL/MASP-1 deposits were performed
within 20 weeks from the onset of disease. Levels of plasma C4d, the activation
fragment of C4, and C4-bp, a soluble regulatory protein of the pathway, were
greater in patients with HSPN than in those with non-IgA GN. However, there was
no difference in serum MBL levels between the three groups of patients (HSPN, IgA
nephropathy, and non-IgA GN). These results suggest that complement activation
through the lectin pathway was involved at the onset of HSPN, and this mechanism
might be important in the disease pathogenesis.
PMID- 10692266
TI - Role of T lymphocytes in renal disease in HIV-transgenic mice.
AB - The pathogenesis of human immunodeficiency virus (HIV)-associated focal segmental
glomerulosclerosis (FSGS) has remained obscure. It has been proposed that renal
parenchymal cells may be infected with HIV-1. If such infection occurs, the
target cells would be expected to express viral proteins and thus could be
targets for cytotoxic T lymphocytes. We previously described mice transgenic for
a gag-pol-deleted HIV-1 genome that developed FSGS. In the present study, we
tested the requirement for functional T cells in the evolution of renal disease
in this model. We bred the HIV-transgenic mice (T26) with athymic nude mice to
produce athymic T26 mice. We confirmed by flow cytometry of peripheral blood,
thymus, lymph node, and spleen that the athymic T26 mice lacked mature T cells.
The athymic T26 mice developed renal disease characterized by FSGS, tubular
atrophy and dilatation, and interstitial infiltrate that was qualitatively
identical to that seen in the parental T26 mice. Quantitative assessment of the
athymic T26 mouse kidneys showed that glomerulosclerosis, tubular injury, and
interstitial infiltrate were less severe compared with the parental T26 mouse
kidneys. Although T26 mouse kidneys had a mixed cellular infiltrate composed of
CD4 cells, CD8 cells, and macrophages, interstitial infiltrates within the
athymic T26 mouse kidneys included macrophages but lacked both CD4 and CD8 cells.
The renal expression of the HIV transgene was 1. 7-fold greater in T26 mice
compared with athymic T26 mice. We conclude that mature T cells are not
absolutely required for the development of HIV-associated nephropathy in
transgenic mice but that, in their absence, renal disease is significantly
milder. These data suggest that T-cell-mediated cytotoxicity directed against
renal cells expressing virally encoded proteins is not an essential feature of
renal pathogenesis in this model.
PMID- 10692267
TI - Characteristics of albumin processing during renal passage in anti-Thy1 and anti
glomerular basement membrane glomerulonephritis.
AB - Recent studies have shown that glomerular-filtered albumin appears to be
processed by two distinct cellular pathways. The major pathway, a high-capacity
retrieval pathway, returns most of the filtered albumin to the blood supply
intact. The albumin not taken up by the retrieval pathway is degraded by
lysosomes during renal passage and excreted as fragments in urine. We studied the
interplay of the albumin retrieval pathway and the degradation pathway in the
disease models of anti-Thy1 nephritis, a model of mild proteinuria, and anti
glomerular basement membrane (anti-GBM) disease, a model of severe proteinuria.
This is achieved by investigating the integrity of urinary albumin and its
excretion rate. Total albumin excretion (intact plus fragments) did not change
significantly in the rats with anti-Thy1 nephritis. However, it was established
that intact albumin excretion had a strong positive correlation with increasing
total-protein excretion, which showed that the degradation pathway was being
predominantly affected in this disease. For the rats with anti-GBM disease, total
protein excretion increased 26-fold compared with the control group, and intact
albumin excretion increased 250-fold. The profound changes in albumin excretion
in anti-GBM disease are consistent with inhibition primarily of the retrieval
pathway.
PMID- 10692268
TI - Effect of antihypertensive therapy on renal function and urinary albumin
excretion in hypertensive patients with autosomal dominant polycystic kidney
disease.
AB - Hypertensive patients with autosomal dominant polycystic kidney disease (ADPKD)
have a faster progression to end-stage renal disease (ESRD) than their
normotensive counterparts. The aim of this prospective, randomized study is to
compare the effects of the calcium channel blocker amlodipine and the angiotensin
converting enzyme inhibitor enalapril as first-line therapy on blood pressure,
renal function, and urinary albumin excretion in hypertensive patients with
ADPKD. Twenty-four patients with ADPKD with hypertension with creatinine
clearances (Ccrs) greater than 50 mL/min/1.73 m(2) were included in the study.
Twelve patients received amlodipine (mean dose, 9 mg/d), and 12 patients received
enalapril (mean dose, 17 mg/d). The patients were followed up for 5 years.
Baseline mean arterial pressures, which were 109 +/- 3 mm Hg in the amlodipine
group and 108 +/- 3 mm Hg in the enalapril group, decreased significantly after 1
year of follow-up (amlodipine, 96 +/- 3 mm Hg; P < 0.005; enalapril, 89 +/- 2 mm
Hg; P < 0.0005) and remained stable at year 5 (amlodipine, 97 +/- 3 mm Hg; P <
0.0005 versus baseline; enalapril, 94 +/- 3 mm Hg; P < 0.005 versus baseline).
Ccrs, which were 83 +/- 5 mL/min/1.73 m(2) in the amlodipine group and 77 +/- 6
mL/min/1.73 m(2) in the enalapril group, remained stable after 1 year of follow
up and decreased significantly at year 3 in both groups (amlodipine, 67 +/- 5
mL/min/1.73 m(2); P < 0.01 versus year 1 and baseline; enalapril, 58 +/- 4
mL/min/1.73 m(2); P < 0.05 versus year 1 and P < 0.0005 versus baseline) with no
significant change thereafter. No change was observed in urinary albumin
creatinine ratio in the amlodipine group (baseline, 68 +/- 21 mg/g; year 1, 52 +/
21 mg/g; year 5, 148 +/- 74 mg/g), whereas it decreased significantly in the
enalapril group at year 1 (baseline, 23 +/- 4 mg/g; year 1, 13 +/- 3 mg/g; P <
0.05) and remained stable until the end of the study at year 5 (14 +/- 6 mg/g).
The investigators concluded that blood pressure was similar in both groups but
only enalapril had a significant effect to sustain decreased urinary albumin
excretion for a 5-year follow-up. Although proteinuria has been considered a
surrogate of renal disease progression, further studies will be necessary to
confirm this hypothesis in ADPKD, because after 5 years, no differences in renal
function were observed between the enalapril and amlodipine groups. In comparison
with patients with ADPKD with uncontrolled hypertension, effective control of
blood pressure, as undertaken in the present study, should delay the onset of
ESRD by approximately 15 years.
PMID- 10692269
TI - Etiologies and outcome of acute renal insufficiency in older adults: a renal
biopsy study of 259 cases.
AB - Acute renal insufficiency is a common problem, yet one that is frequently
reversible with proper diagnosis and treatment. Although it has been argued that
a renal biopsy is not needed for diagnosis in most cases of acute renal failure
in the elderly, other studies have shown frequent disagreements between clinical
and renal biopsy diagnoses in such cases. To investigate the causes of acute
renal insufficiency in patients aged at least 60 years who underwent a renal
biopsy and possible correlations between biopsy findings and renal survival, we
first identified all native renal biopsy specimens from patients aged 60 years or
older processed at The University of Chicago Medical Center (Chicago, IL) from
1991 through 1998 and reviewed the clinical records to determine the indication
for the biopsy. We then reviewed again the records of those patients who
underwent biopsy because of acute renal insufficiency, recorded the primary renal
biopsy diagnosis in each of these cases, and obtained follow-up information for
patients who underwent biopsy before July 1996. During the study period, 1,065 of
4,264 biopsy specimens (25.0%) received were obtained from patients aged 60 years
or older, and acute renal insufficiency was the indication for biopsy in 259 of
these patients (24.3%). The most frequent primary diagnoses on these latter
biopsy specimens were pauci-immune crescentic glomerulonephritis (GN) with or
without arteritis, 31.2% of biopsy specimens; acute interstitial nephritis,
18.6%; acute tubular necrosis (ATN) with nephrotic syndrome, 7.5%; atheroemboli,
7.1%; ATN alone, 6.7%; light chain cast nephropathy (LCCN), 5.9%; postinfectious
GN, 5.5%; anti-glomerular basement membrane antibody nephritis, 4.0%; and
immunoglobulin A (IgA) nephropathy and/or Henoch-Schonlein nephritis, 3.6%. Eight
biopsy specimens (3.2%) showed only benign nephrosclerosis without an apparent
cause of acute renal insufficiency, and another six specimens were inadequate.
The renal biopsy diagnosis was in agreement with the prebiopsy clinical diagnosis
(or differential diagnosis) in 107 of the 161 cases (67%) in which such
information was provided. The distribution of diagnoses was similar in patients
in the age groups of 60 to 69, 70 to 79, and 80 years or older, although younger
age correlated significantly with improved renal and patient survival. The
relative risk for progression to end-stage renal disease (ESRD) also increased
according to diagnostic categories: LCCN (greatest risk) > GN other than pauci
immune > atheroemboli congruent with pauci-immune crescentic GN >
tubulointerstitial diseases other than LCCN (the latter category including ATN
with nephrotic syndrome). Development of ESRD correlated significantly with
decreased patient survival. In summary, renal biopsy in patients aged 60 years or
older with acute renal insufficiency uncovered the cause in greater than 90% of
the cases and provided clinically useful information with respect to expectation
for renal survival and potential treatment options.
PMID- 10692270
TI - Current indications for renal biopsy: a questionnaire-based survey.
AB - Indications for renal biopsy are still ill defined. We recently sent a detailed
questionnaire to 360 nephrologists in different areas of the world with the aim
of providing information on this critical issue by evaluating the replies. The
questionnaire was organized in four sections that included questions on renal
biopsy indications in patients with normal renal function, renal insufficiency,
and a transplanted kidney. In addition, the questions included methods applied to
each renal biopsy procedure and to specimen processing. We received 166 replies;
North Europe (50 replies), South Europe (47 replies), North America (31 replies),
Australia and New Zealand (24 replies), and other countries (14 replies). In
patients with normal renal function, primary indications for renal biopsy were
microhematuria associated with proteinuria, particularly greater than 1 g/d of
protein. In chronic renal insufficiency, kidney dimension was the major parameter
considered before renal biopsy, whereas the presence of diabetes or serological
abnormalities was not considered critical. In the course of acute renal failure
(ARF) of unknown origin, 20% of the respondents would perform renal biopsy in the
early stages, 26% after 1 week of nonrecovery, and 40% after 4 weeks. In a
transplanted kidney, the majority of nephrologists would perform a renal biopsy
in the case of graft failure after surgery, ARF after initial good function, slow
progressive deterioration of renal function, and onset of nephrotic proteinuria.
The last section provided comprehensive information on the technical aspects of
renal biopsy. This survey represents the first attempt to provide a reliable
consensus that can be used in developing guidelines on the use of kidney biopsy.
PMID- 10692271
TI - Effect of 22-oxacalcitriol on bone histology of hemodialyzed patients with severe
secondary hyperparathyroidism.
AB - To examine the effectiveness of 22-oxacalcitriol (OCT) injection on the
improvement of severe osteitis fibrosa, we studied 10 hemodialyzed patients (age,
59 +/- 12 years). The initial OCT dose was 5 microg and was administered three
times weekly at the end of each hemodialysis session. OCT doses (1, 3, 5, 10, 15,
and 20 microg) were changed in subsequent weeks to maintain serum calcium levels
at less than 11.5 mg/dL. Administration of OCT significantly suppressed serum
intact parathyroid hormone (PTH) from an initial level of 1,193 +/- 584 to 775 +/
552 pg/mL in the 24th week (n = 10). OCT increased PTH levels again to 857 +/-
635 pg/mL in the 48th week (n = 7). Among the 10 patients, 5 patients (high
responders) showed more than a 50% suppression of serum intact PTH levels at the
end of the study. The rest of the patients had hypercalcemia and did not receive
increased OCT doses (low responders). At the start of the treatment, the only
difference between high and low responders was serum calcium level. Serum calcium
levels (adjusted for serum albumin level) increased from 9.7 +/- 0.7 mg/dL (n =
10) at the beginning to 10.5 +/- 0.6 mg/dL (n = 10) in the 24th week and to 11. 1
+/- 0.7 mg/dL (n = 7) in the 48th week. Six patients (1 to 6) agreed to undergo a
second bone biopsy in the 24th week of OCT administration. In bone
histomorphometric measurements, OCT significantly changed bone marrow fibrosis,
mineralization (labeled mineralizing surface and bone formation rate), and
osteoid formation (osteoid volume and thickness). In conclusion, intravenous OCT
effectively suppressed PTH secretion and improved the bone histological
characteristics of severe osteitis fibrosa, especially in patients with initial
serum calcium levels less than 10 mg/dL. With concerns about OCT causing adynamic
bone, additional bone histological data are needed to ensure the long-term safety
of OCT.
PMID- 10692272
TI - Presence of sonographically detectable parathyroid glands can predict resistance
to oral pulsed-dose calcitriol treatment of secondary hyperparathyroidism.
AB - Oral pulsed-dose calcitriol administration has been shown to be effective therapy
for patients with secondary hyperparathyroidism. However, this effect is not
consistently observed in the clinical setting. This study was undertaken to
examine whether enlarged parathyroid glands can serve as a clinical marker that
predicts the suppressive effect of calcitriol. Thirty-five patients undergoing
chronic hemodialysis (HD) were examined (age, 51.9 +/- 14.9 years; duration of
HD, 72.0 +/- 56.0 months). Based on the volume of parathyroid glands measured
using an ultrasonographic scanner, patients were divided into two groups: 15
patients with undetectable parathyroid glands (ND group) and 20 patients with
detectable parathyroid glands (D group; mean volume of parathyroid glands, 261. 9
+/- 347.5 mm(3)). No significant differences were found in serum ionized calcium
(Ca(++)) or parathyroid hormone (PTH) levels before calcitriol administration
between the two groups. For each patient, 8 microg of calcitriol was administered
orally at the end of the HD session, and the changes in serum PTH levels were
determined 44 hours after dosing. No significant differences were found between
the two groups in serum Ca(++) levels. However, a significant decrease in serum
PTH levels was observed in the ND group, whereas no significant changes were
found in the D group. The results of the study show that the suppressive effect
on PTH through calcitriol therapy was reduced in patients with detectable
enlarged parathyroid glands. This may indicate that the size of parathyroid
glands is one factor determining the therapeutic potential of pulsed-dose
calcitriol administration for secondary hyperparathyroidism.
PMID- 10692273
TI - C-Reactive protein predicts all-cause and cardiovascular mortality in
hemodialysis patients.
AB - Hypoalbuminemia predicts death in dialysis patients. Although hypoalbuminemia has
been attributed to malnutrition, evidence of inflammation (C-reactive protein
[CRP] and cytokine levels) has recently been recognized to predict albumin
concentration in dialysis patients. We measured CRP and albumin levels in October
1995 in 91 hemodialysis (HD) patients. During a 34-month follow-up period, we
determined the incidence and cause of death. Patients were divided into four
groups based on serum albumin levels (<3.5 [lowest quartile], 3.5 to 3.8, 3.9 to
4.0, and >4.0 g/dL [highest quartile]). Survival differed among the four groups
(P = 0.0063). Patients with albumin levels greater than 4.0 g/dL had the greatest
survival. Kaplan-Meier survival estimates of patients from varying CRP quartiles
(<2.6, 2.6 to 5.2, 5.3 to 11.5, and >11.5 microg/mL) differed among the four
groups (P < 0.0001). The group with the greatest CRP level (>11.5 microg/mL) had
the lowest survival. Multivariate analysis using the Cox proportional hazards
model showed that only CRP level (chi-square = 21.11; P < 0.0001) and age (chi
square = 5.44; P = 0.020) predicted death. Albumin level (chi-square = 0.16; P =
0.69) was not predictive. Only when CRP was excluded from the model did low serum
albumin level (chi-square = 12. 04; P = 0.0004) predict death. CRP level (chi
square = 16.79; P < 0. 0001) and age (chi-square = 6.38; P = 0.012) also
superceded albumin level (chi-square = 0.45; P = 0.51) in predicting
cardiovascular mortality. Although values for blood urea nitrogen, creatinine,
and normalized protein catabolic rate were significantly less among patients who
died, these parameters, as well as cholesterol level and diabetes, were not
important predictors of death in multivariate analysis. The acute-phase response
or the cause of the acute-phase response is largely responsible for the effect of
hypoalbuminemia on mortality in HD patients.
PMID- 10692274
TI - New ultrasound approaches to dialysis access monitoring.
AB - The failure of dialysis access is a frequent source of morbidity and
hospitalization. Traditional methods of graft surveillance include: (1) clinical
examination, (2) venous line pressure measurements during dialysis, (3) urea or
tracer recirculation measurement, (4) continuous wave (CW) Doppler methods, (5)
duplex ultrasonography, and (6) radiograph angiography. All these methods require
special training and/or laboratory tests. The purpose of this study was to test a
simple continuous-wave Doppler method that could be applied to measure the flow
rate in dialysis access every time the patient undergoes dialysis. Twenty
dialysis patients, 15 with polytetrafluoroethylene grafts and 5 with
arteriovenous fistulae, were studied. Two hundred fifty-three examinations were
performed over an 8-month period. Doppler waveforms of the access flow were
obtained with the pump on, with the pump off, and with the pump on again.
Systolic and diastolic Doppler frequency measurements were made, and the pump-on
and pump-off measurements were compared. In an access functioning normally, the
Doppler frequencies are higher with the pump off than with the pump on. In 22% of
the cases, there were abnormal findings in which the Doppler frequencies were
lower with the pump off than with the pump on. This occurs if the needles are
incorrectly placed, suggesting that recirculation is occurring. Recirculation
also occurs if there is stenosis of the access. Examining the hemodialysis access
during each dialysis session with an inexpensive directional Doppler may identify
a significant stenosis and improve the efficiency of dialysis by detecting those
patients in whom the arterial and venous needles are reversed.
PMID- 10692275
TI - Physical functioning and health-related quality-of-life changes with exercise
training in hemodialysis patients.
AB - The Renal Exercise Demonstration Project was designed to test the effects of two
different approaches to exercise programming on the levels of physical activity,
physical functioning, and self-reported health status in hemodialysis patients.
Two hundred eighty-six patients were recruited for participation. Intervention
patients were given individually prescribed exercise for 8 weeks of independent
home exercise, followed by 8 weeks of incenter cycling during dialysis. Physical
performance testing was performed at baseline and after each intervention using
gait speed, sit-to-stand test, and 6-minute walk. The Medical Outcomes Study
Short Form 36-item (SF-36) questionnaire was used to assess self-reported health
status. The intervention group showed increased participation in physical
activity. There were significant differences between the intervention and
nonintervention groups in change over time in normal and fast gait speed, sit-to
stand test scores, and the physical scales on the SF-36, including the physical
component scale. The intervention group improved in these test results, whereas
the nonintervention group either did not change or declined over the duration of
the study. It is clear that improvements in physical functioning result from
exercise counseling and encouragement in hemodialysis patients. Because self
reported physical functioning is highly predictive of outcomes in hemodialysis
patients, more attention to patients' levels of physical activity is warranted.
PMID- 10692277
TI - Prolonged sulfonylurea-induced hypoglycemia in diabetic patients with end-stage
renal disease.
AB - Renal impairment is a recognized risk factor for prolonged hypoglycemia, but
predisposing characteristics in patients with advanced renal impairment have not
been studied. We observed prolonged hypoglycemia in a number of patients with end
stage renal disease (ESRD) and conducted a case-control study at two Canadian
centers to identify such risk factors. Through hospital, pharmacy, and dialysis
program records, we retrospectively identified 7 case patients and 31 controls
with ESRD and type 2 diabetes using oral hypoglycemic monotherapy. Control
patients had no history of hospital admission for prolonged hypoglycemia. All
case patients and 28 controls were receiving glyburide (glibenclamide in Europe);
the remainder were treated with tolbutamide. Duration of intravenous treatment
for hypoglycemia ranged from 28 to 256 hours, with 83 g to 2 kg of glucose
administered per episode. Preceding treatment with glyburide varied from 2 days
to 13 years. Univariate analyses showed a recent decline in oral intake (odds
ratio [OR], 81; 95% confidence interval [CI], 3.6 to 1,840), previous
hypoglycemic episodes (OR, 15; 95% CI, 0.77 to 297), longer duration of diabetes
(22 versus 12 years; P = 0.008), and a history of cerebrovascular disease (OR, 7.
0; 95% CI, 1.0 to 47) to be associated with prolonged hypoglycemia. No
association between prolonged hypoglycemia and age, sex, beta blockers,
angiotensin-converting enzyme inhibitors, oral hypoglycemic dose, or duration of
treatment was identified. This study describes the potentially devastating effect
of sulfonylurea-based oral hypoglycemic therapy in ESRD. Patients at greatest
risk appear to be those with reduced intake, previous hypoglycemic episodes, and
longer duration of diabetes. We describe the mechanisms for observed hypoglycemia
and suggest that alternative drugs may be considered in this patient group.
PMID- 10692276
TI - Dialysate made from dry chemicals using citric acid increases dialysis dose.
AB - A new dry dialysate concentrate acidified with citric acid (citrate dialysate)
has been used in two separate clinical studies of hemodialysis patients. The
first compared a single treatment using this dialysate, with one dialysis using
regular standard dialysate acidified with acetic acid (regular dialysate) in a
prospective, randomized, crossover study of 74 dialyses. Changes in blood levels
of electrolytes and other blood constituents during dialysis were calculated by
subtracting postdialysis from predialysis blood concentrations. Compared with
acetic acid dialysate, citrate dialysate was associated with significantly
greater decreases in total and ionized calcium, magnesium, and chloride levels.
Citrate dialysate was also associated with greater increases in serum sodium and
citrate concentrations, although their postdialysis concentrations remained
within or just outside normal ranges. Changes in other blood constituents were
similar with both dialysates. The second study used citrate dialysate exclusively
for all dialyses over a 12-week period in 25 patients. Predialysis blood samples
were drawn at the start of the study and at 4-week intervals thereafter, and
postdialysis blood samples were obtained after the first and last dialysis.
Repeated-measure analysis showed that although predialysis blood concentrations
of magnesium, potassium, and citrate remained within the normal range, there was
a significant declining trend over the course of the study. At the same time,
predialysis serum bicarbonate levels increased, and significantly more patients
had a predialysis bicarbonate concentration within the normal range at the end of
the study than at the start (15 versus 8 patients; P = 0.001, chi-square). In 19
patients (excluding 3 patients for whom the type of dialyzer was changed during
the study), the dose of dialysis for the first and last dialysis was calculated
by urea reduction ratio and Kt/V. There was a significant increase in both
measurements without changes in dialysis time, blood and dialysate flows, or
dialyzer used. The urea reduction ratio increased from 68% +/- 5.9% to 73% +/-
5.3% (P < 0. 03), and the Kt/V from 1.23 +/- 0.19 to 1.34 +/- 0.20 (P = 0.01)
from the first to last dialysis, respectively. In conclusion, this citric acid
dialysate was well tolerated, and intradialytic changes in blood chemistries were
similar to those seen with regular dialysate. Using dialysate containing citric
instead of acetic acid increases the delivered dialysis dose.
PMID- 10692278
TI - A multicenter study of noncompliance with continuous ambulatory peritoneal
dialysis exchanges in US and Canadian patients.
AB - Recent evidence suggested that noncompliance (NC) with continuous ambulatory
peritoneal dialysis (CAPD) exchanges may be more common in US than in Canadian
dialysis centers. This issue was investigated using a questionnaire-based method
in 656 CAPD patients at 14 centers in the United States and Canada. NC was
defined as missing more than one exchange per week or more than two exchanges per
month. Patients were ensured of the confidentiality of their individual results.
Mean patient age was 56 +/- 16 years, 52% were women, and 39% had diabetes. The
overall admitted rate of NC was 13%, with a rate of 18% in the United States and
7% in Canada (P < 0.001). NC was more common in younger patients (P < 0.0001),
those without diabetes (P < 0.001), and employed patients (P < 0.05). It was also
more common in black and Hispanic than in Asian and white patients (P < 0.001).
NC was more common in patients prescribed more than four exchanges daily (P <
0.0001) but was not affected by dwell volume. On multiple regression analysis,
the independent predictors of NC, in order of importance, were being prescribed
more than four exchanges per day, black race, being employed, younger age, and
not having diabetes. Being treated in a US unit did not quite achieve
significance as a multivariate independent predictor. These findings suggest that
NC is not uncommon in CAPD patients and is more frequent in US than in Canadian
patients. However, country of residence is less powerful as a predictor of NC
than a variety of other demographic and prescription factors.
PMID- 10692279
TI - Multicenter cross-sectional study for dialysis dose and physician's subjective
judgment in Japanese peritoneal dialysis patients. Group for the Water and
Electrocyte Balance Study in CAPD.
AB - The purpose of this study was to investigate the state of dialysis and nutrition
among Japanese peritoneal dialysis (PD) patients. Two hundred thirty-nine
Japanese PD patients from 21 centers, 79 female and 160 male, were evaluated to
determine their status of dialysis and nutrition. Mean age of the patients was 50
years; mean duration on PD, 4.2 years; mean body weight, 58 kg; and body surface
area (BSA), 1.61 m(2). Sixty-three percent of the patients had no residual renal
function. Mean daily delivered volume was 6.9 L for female continuous ambulatory
peritoneal dialysis (CAPD), 8.1 L for male CAPD, 10.5 L for female automated
peritoneal dialysis (APD), and 10.7 L for male APD. Total (dialysis and kidney)
mean weekly values for creatinine clearance (Ccr), Kt/V, and beta2 microglobulin
(beta2MG) clearance were 56 L/1.75 m(2), 1.80, and 11 L/1.73 m(2), respectively.
Fifty percent of the patients who had no residual renal function (RRF) and 17% of
the patients with RRF did not achieve 50 L/wk/1.73 m(2) of Ccr. With regard to
nutritional parameters, mean values for plasma total protein, serum albumin, and
normalized protein catabolic rate (nPCR) were 6.5 g/dL, 3.6 g/dL, and 0.97 g/kg
BW/d. Mean daily protein loss was 5.8 g. Although a significant number of
patients did not achieve 50 or 60 L/wk/1.73 m(2) of Ccr, the physicians
determined that 72% of the patients received adequate dialysis and 71% were well
nourished according to clinical and laboratory features. In conclusion, the daily
prescribed volume and the delivered dialysis dose were lower than expected. The
discrepancy between the actual delivered dialysis dose and the physicians'
evaluation should be explored in the future.
PMID- 10692280
TI - Ultrasound detection of microembolic signals in hemodialysis accesses.
AB - Microembolic signals (MES) detected by ultrasound, thought to be of gaseous or
solid origin, have been described with decompression illness and in the
intracranial and cardiopulmonary circulation. We describe the first reported
cases of MES occurring in hemodialysis accesses. Two hemodialysis patients, one
with a synthetic graft and one with an arteriovenous fistula, showed MES during a
dialysis session detected by duplex ultrasound. We postulate that these MES
represent cavitation bubbles developing from turbulent blood flow around the
venous needle in the access. However, other potential causes exist, including air
introduced into the circulation from the dialysis circuit or microemboli arising
from thrombus or atheroma.
PMID- 10692281
TI - Access recirculation in a native fistula in spite of a seemingly adequate access
flow.
AB - True access recirculation (AR) measured by ultrasound dilution technique is
usually absent in well-working shunts. It occurs with low access flows (Qa). High
access flow rates are assumed to prevent AR. Two major exceptions to these rules
are known: presence of intra-access strictures and inadvertently reversed blood
lines. We present an additional exception in which true access recirculation
occurred in a native arteriovenous (AV) fistula with correct placement of
bloodlines. Surprisingly, access blood flow exceeded pump blood flow (Qb) almost
threefold. The situation was clarified by a magnetic resonance angiogram showing
a collateral forming a functional loop. This loop led to true access
recirculation in one branch, although overall blood flow through both branches
appeared to be adequate. The different findings in this shunt over time give
insight into the often complex pathophysiology of native fistulae. This case
proves that seemingly adequate access flow does not necessarily prevent access
recirculation in native AV fistulae. We suggest monitoring both access flow and
recirculation in hemodialysis accesses on a regular basis.
PMID- 10692282
TI - Thin basement membrane disease and acute renal failure secondary to gross
hematuria and tubular necrosis.
AB - A patient with thin basement membrane disease (TBMD), macroscopic hematuria, and
acute renal failure is described. A renal biopsy showed massive occlusion of
renal tubules by red blood cells and casts. This was accompanied by tubular cell
damage consistent with acute tubular necrosis. The patient was receiving warfarin
because of a history of deep venous thrombosis at the time he developed the acute
renal failure. The possible relationship of the warfarin therapy to the TBMD,
intratubular hemorrhage, and acute renal failure are discussed.
PMID- 10692283
TI - Thrombocytopenia after kidney transplantation.
AB - We report a case of posttransplant malaria in which the patient developed
progressive thrombocytopenia after receiving living related donor kidney
transplantation. The donor, who flew in from Sri Lanka for the procedure, had
suffered from malaria 18 months earlier. Malaria should be suspected in
transplant patients receiving organs from donors originating from countries with
a high prevalence of malaria.
PMID- 10692284
TI - Long-term cyclophosphamide treatment for recurrent type I membranoproliferative
glomerulonephritis after transplantation.
AB - The incidence of recurrent type I membranoproliferative glomerulonephritis (MPGN)
after renal transplant is approximately 30%, and the rate of graft loss due to
recurrent MPGN type I is higher than 50%. The treatment of this disease has not
been defined. We report a case of recurrent MPGN type diagnosed 4 months after a
cadaveric renal transplantation. The patient was treated with cyclophosphamide
and was able to maintain her graft function. Cyclophosphamide was interrupted
three times during the course. Each time her renal function deteriorated and her
serum albumin decreased. The patient currently has a functional renal graft 3
years after transplantation while receiving low-dose therapy with
cyclophosphamide. We suggest treating recurrent type I MPGN with cyclophosphamide
while continuing the calcineurin inhibitor and prednisone.
PMID- 10692285
TI - Renal biopsy in the elderly.
PMID- 10692286
TI - Hypertension, proteinuria, and progression of autosomal dominant polycystic
kidney disease: where do we go from here?
PMID- 10692287
TI - IgA1 glycosylation and the pathogenesis of IgA nephropathy.
PMID- 10692288
TI - Acute renal failure with interstitial nephritis in a patient with AIDS.
PMID- 10692289
TI - Risk for posttransplant diabetes mellitus with current immunosuppressive
medications.
PMID- 10692290
TI - Hypertension in the hemodialysis patient.
PMID- 10692294
TI - Disappearance of nodular mesangial lesions in a patient with light chain
nephropathy after long-term chemotherapy.
AB - A 64-year-old man developed multiple myeloma (kappa light chain type), nephrotic
syndrome, and renal insufficiency in 1993. A renal biopsy showed typical
histological findings of light chain nephropathy: nodular glomerulosclerosis with
deposition of kappa light chains in the mesangial area and subendothelial space
of the glomerular capillary walls. Long-term intermittent MEVP chemotherapy
(melphalan, 4 mg/d for 4 days; cyclophosphamide, 100 mg/d for 4 days;
vincristine, 1 mg/d; prednisolone, 40 mg/d for 4 days) diminished proteinuria and
improved renal function. In April 1999, a follow-up biopsy showed remarkable
diminution of nodular lesions and disappearance of kappa light chain deposits.
Although the prognosis of light chain nephropathy has been considered poor, long
term successful chemotherapy can clear light chain deposits and restore renal
function.
PMID- 10692295
TI - De novo ANCA-associated vasculitis occurring 14 years after kidney
transplantation.
AB - A cadaveric kidney transplant recipient, with no history of a connective tissue
disease, was admitted with malaise, arthralgias, diplopia, mild headache, and a
painful left eye. The patient was on maintenance immunosuppression for 14 years
with cyclosporine and methylprednisolone. Initial laboratory data indicated an
elevated serum creatinine from baseline, 2+ proteinuria, and 50 to 100 red blood
cells (RBCs)/high-power field (HPF) in the urine. Renal biopsy was consistent
with necrotizing vasculitis involving glomerular capillaries, with crescent
formation and an absence of immune complexes. Perinuclear antineutrophil
cytoplasmic autoantibodies (P-ANCA) and anti-myeloperoxidase (MPO) were found to
be elevated. To the best of our knowledge, this is the first reported case of an
ANCA-associated small vessel vasculitis (SVV) developing in a renal transplant
recipient without history of connective tissue disease.
PMID- 10692296
TI - Extensive intraglomerular thrombi of monoclonal IgM-kappa in a patient with
malignant lymphoma.
AB - We describe an 80-year-old man who developed malignant lymphoma (ML) complicated
by extensive intraglomerular thrombi of immunoglobulin M (IgM)-kappa monoclonal
immunoglobulin. The clinical picture was characterized by nephrotic syndrome and
systemic lymphadenopathy. Laboratory examination showed mild anemia and a small
amount of monoclonal IgM-kappa in the blood. The histopathologic findings and
surface immunoglobulin analysis of the lymph node biopsy specimen were consistent
with CD5-positive diffuse large B-cell (type, IgM-kappa) lymphoma. The subsequent
renal biopsy showed a massive deposition of amorphous material in the glomerular
capillary lumens, subendothelial areas, and mesangium. Nodular glomerulosclerosis
was not found. An immunofluorescent study showed that the deposits consisted of
IgM-kappa monoclonal immunoglobulin. Ultrastructurally, the deposits were
composed of granular electron-dense material. Chemotherapy was effective for both
the ML and nephrotic syndrome, and the patient's urine analysis results returned
to normal. The histopathologic manifestations of this case are rare, and the
pathogenesis of these glomerular lesions was obviously associated with ML.
PMID- 10692297
TI - Reactivation of tuberculosis after conversion from azathioprine to mycophenolate
mofetil 16 years after renal transplantation.
AB - The incidence of tuberculosis among transplant recipients is greater than in the
general population. Mycophenolate mofetil (MMF) is a potent immunosuppressive
agent that has become part of most standard immunosuppressive protocols after
renal transplantation. We have recently shown that conversion from azathioprine
(AZA) to MMF in patients with chronic allograft dysfunction may be beneficial.
Here, we report a patient with a history of pulmonary tuberculosis during his
childhood. This patient was converted from AZA to MMF therapy 16 years after
allogenic renal transplantation because of chronic allograft dysfunction. Two
months later, he developed axillary lymph node tuberculosis caused by
Mycobacterium tuberculosis. Because he denied contact with infectious persons, we
diagnosed reactivation of old dormant tuberculosis. After surgical extirpation,
quadruple antituberculous therapy was administered for 3 months (isoniazid,
rifampicin, ethambutol, and pyrazinamide), followed by dual therapy for 3 months
(isoniazid and rifampicin), and monotherapy for another 3 months (isoniazid). In
the follow-up period, he remained asymptomatic with stable graft function. We
conclude that MMF therapy in renal allograft recipients may cause reactivation of
old dormant tuberculosis, even in the very late posttransplantation period. In
these patients, close monitoring and isoniazid prophylaxis may be useful.
PMID- 10692298
TI - Physiologic and pathophysiologic renal consequences of H(+)-stimulated endothelin
secretion.
PMID- 10692299
TI - How yeast cells synchronize their glycolytic oscillations: a perturbation
analytic treatment.
AB - Of all the lifeforms that obtain their energy from glycolysis, yeast cells are
among the most basic. Under certain conditions the concentrations of the
glycolytic intermediates in yeast cells can oscillate. Individual yeast cells in
a suspension can synchronize their oscillations to get in phase with each other.
Although the glycolytic oscillations originate in the upper part of the
glycolytic chain, the signaling agent in this synchronization appears to be
acetaldehyde, a membrane-permeating metabolite at the bottom of the anaerobic
part of the glycolytic chain. Here we address the issue of how a metabolite
remote from the pacemaking origin of the oscillation may nevertheless control the
synchronization. We present a quantitative model for glycolytic oscillations and
their synchronization in terms of chemical kinetics. We show that, in essence,
the common acetaldehyde concentration can be modeled as a small perturbation on
the "pacemaker" whose effect on the period of the oscillations of cells in the
same suspension is indeed such that a synchronization develops.
PMID- 10692300
TI - Kinetics of desolvation-mediated protein-protein binding.
AB - The role of desolvation in protein binding kinetics is investigated using
Brownian dynamics simulations in complexes in which the electrostatic
interactions are relatively weak. We find that partial desolvation, modeled by a
short-range atomic contact potential, is not only a major contributor to the
binding free energy but also substantially increases the diffusion-limited rate
for complexes in which long-range electrostatics is weak. This rate enhancement
is mostly due to weakly specific pathways leading to a low free-energy attractor,
i.e., a precursor state before docking. For alpha-chymotrypsin and human
leukocyte elastase, both interacting with turkey ovomucoid third domain, we find
that the forward rate constant associated with a collision within a solid angle
phi around their corresponding attractor approaches 10(7) and 10(6) M(-1)s(-1),
respectively, in the limit phi approximately 2 degrees. Because these estimates
agree well with experiments, we conclude that the final bound conformation must
be preceded by a small set of well-defined diffusion-accessible precursor states.
The inclusion of the otherwise repulsive desolvation interaction also explains
the lack of aggregation in proteins by restricting nonspecific association times
to approximately 4 ns. Under the same reaction conditions but without short range
forces, the association rate would be only approximately 10(3) M(-1)s(-1).
Although desolvation increases these rates by three orders of magnitude,
desolvation-mediated association is still at least 100-fold slower than the
electrostatically assisted binding in complexes such as barnase and barstar.
PMID- 10692301
TI - Quantal potential fields around individual active zones of amphibian motor-nerve
terminals.
AB - The release of a quantum from a nerve terminal is accompanied by the flow of
extracellular current, which creates a field around the site of transmitter
action. We provide a solution for the extent of this field for the case of a
quantum released from a site on an amphibian motor-nerve terminal branch onto the
receptor patch of a muscle fiber and compare this with measurements of the field
using three extracellular electrodes. Numerical solution of the equations for the
quantal potential field in cylindrical coordinates show that the density of the
field at the peak of the quantal current gives rise to a peak extracellular
potential, which declines approximately as the inverse of the distance from the
source at distances greater than about 4 microm from the source along the length
of the fiber. The peak extracellular potential declines to 20% of its initial
value in a distance of about 6 microm, both along the length of the fiber and in
the circumferential direction around the fiber. Simultaneous recordings of
quantal potential fields, made with three electrodes placed in a line at right
angles to an FM1-43 visualized branch, gave determinations of the field strengths
in accord with the numerical solutions. In addition, the three electrodes were
placed so as to straddle the visualized release sites of a branch. The positions
of these sites were correctly predicted on the basis of the theory and
independently ascertained by FM1-43 staining of the sites. It is concluded that
quantal potential fields at the neuromuscular junction that can be measured with
available recording techniques are restricted to regions within about 10 microm
of the release site.
PMID- 10692302
TI - Effect of voltage drop within the synaptic cleft on the current and voltage
generated at a single synapse.
AB - In a model of a single synapse with a circular contact zone and a single
concentric zone containing receptor-gated channels, we studied the dependence of
the synaptic current on the synaptic cleft width and on the relative size of the
receptor zone. During synaptic excitation, the extracellular current entered the
cleft and flowed into the postsynaptic cell through receptor channels distributed
homogeneously over the receptor zone. The membrane potential and channel currents
were smaller toward the cleft center if compared to the cleft edges. This radial
gradient was due to the voltage drop produced by the synaptic current on the
cleft resistance. The total synaptic current conducted by the same number of open
channels was sensitive to changes in the receptor zone radius and the cleft
width. We conclude that synaptic geometry may affect synaptic currents by
defining the volume resistor of the cleft. The in-series connection of the
resistances of the intracleft medium and the receptor channels plays the role of
the synaptic voltage divider. This voltage dividing effect should be taken into
account when the conductance of single channels or synaptic contacts is estimated
from experimental measurements of voltage-current relationships.
PMID- 10692303
TI - Backbone dipoles generate positive potentials in all proteins: origins and
implications of the effect.
AB - Asymmetry in packing the peptide amide dipole results in larger positive than
negative regions in proteins of all folding motifs. The average side chain
potential in 305 proteins is 109 +/- 30 mV (2. 5 +/- 0.7 kcal/mol/e). Because the
backbone has zero net charge, the non-zero potential is unexpected. The larger
oxygen at the negative and smaller proton at the positive end of the amide dipole
yield positive potentials because: 1) at allowed phi and psi angles residues come
off the backbone into the positive end of their own amide dipole, avoiding the
large oxygen; and 2) amide dipoles with their carbonyl oxygen surface exposed and
amine proton buried make the protein interior more positive. Twice as many amides
have their oxygens exposed than their amine protons. The distribution of acidic
and basic residues shows the importance of the bias toward positive backbone
potentials. Thirty percent of the Asp, Glu, Lys, and Arg are buried. Sixty
percent of buried residues are acids, only 40% bases. The positive backbone
potential stabilizes ionization of 20% of the acids by >3 pH units (-4.1
kcal/mol). Only 6.5% of the bases are equivalently stabilized by negative
regions. The backbone stabilizes bound anions such as phosphates and rarely
stabilizes bound cations.
PMID- 10692304
TI - Transduction of intracellular and intercellular dynamics in yeast glycolytic
oscillations.
AB - Under certain well-defined conditions, a population of yeast cells exhibits
glycolytic oscillations that synchronize through intercellular acetaldehyde. This
implies that the dynamic phenomenon of the oscillation propagates within and
between cells. We here develop a method to establish by which route dynamics
propagate through a biological reaction network. Application of the method to
yeast demonstrates how the oscillations and the synchronization signal can be
transduced. That transduction is not so much through the backbone of glycolysis,
as via the Gibbs energy and redox coenzyme couples (ATP/ADP, and NADH/NAD), and
via both intra- and intercellular acetaldehyde.
PMID- 10692305
TI - A model for the lipid pretransition: coupling of ripple formation with the chain
melting transition.
AB - Below the thermotropic chain-melting transition, lipid membrane c(P) traces
display a transition of low enthalpy called the lipid pretransition. It is linked
to the formation of periodic membrane ripples. In the literature, these two
transitions are usually regarded as independent events. Here, we present a model
that is based on the assumption that both pretransition and main transition are
caused by the same physical effect, namely chain melting. The splitting of the
melting process into two peaks is found to be a consequence of the coupling of
structural changes and chain-melting events. On the basis of this concept, we
performed Monte Carlo simulations using two coupled monolayer lattices. In this
calculation, ripples are considered to be one-dimensional defects of fluid lipid
molecules. Because lipids change their area by approximately 24% upon melting,
line defects are the only ones that are topologically possible in a triangular
lattice. The formation of a fluid line defect on one monolayer leads to a local
bending of the membrane. Geometric constraints result in the formation of
periodic patterns of gel and fluid domains. This model, for the first time, is
able to predict heat capacity profiles, which are comparable to the experimental
c(P) traces that we obtained using calorimetry. The basic assumptions are in
agreement with a large number of experimental observations.
PMID- 10692306
TI - Properties of the stochastic energization-relaxation channel model for vectorial
ion transport.
AB - A model for the primary active transport by an ion pump protein is proposed. The
model, the "energization-relaxation channel model," describes an ion pump as a
multiion channel that undergoes stochastic transitions between two conformational
states by external energy supply. When the potential profile along ion transport
pathway is asymmetrical, a net ion flux is induced by the transitions. In this
model, the coupling of the conformational change and ion transport is stochastic
and loose. The model qualitatively reproduces known properties of active
transport such as the effect of ion concentration gradient and membrane potential
on the rate of transport and the inhibition of ion transport at high ion
concentration. We further examined the effect of various parameters on the ion
transport properties of this model. The efficiency of the coupling was almost
100% under some conditions.
PMID- 10692307
TI - Mechanism of lateral movement of filopodia and radial actin bundles across
neuronal growth cones.
AB - We investigated the motion of filopodia and actin bundles in lamellipodia of
motile cells, using time-lapse sequences of polarized light images. We measured
the velocity of retrograde flow of the actin network and the lateral motion of
filopodia and actin bundles of the lamellipodium. Upon noting that laterally
moving filopodia and actin bundles are always tilted with respect to the
direction of retrograde flow, we propose a simple geometric model for the
mechanism of lateral motion. The model establishes a relationship between the
speed of lateral motion of actin bundles, their tilt angle with respect to the
direction of retrograde flow, and the speed of retrograde flow in the
lamellipodium. Our experimental results verify the quantitative predictions of
the model. Furthermore, our observations support the hypothesis that lateral
movement of filopodia is caused by retrograde flow of tilted actin bundles and by
their growth through actin polymerization at the tip of the bundles inside the
filopodia. Therefore we conclude that the lateral motion of tilted filopodia and
actin bundles does not require a separate motile mechanism but is the result of
retrograde flow and the assembly of actin filaments and bundles near the leading
edge of the lamellipodium.
PMID- 10692308
TI - Rigidity of triskelion arms and clathrin nets.
AB - Statistical analysis is applied to a set of electron micrographic images (Kocsis,
E., B. L. Trus, C. J. Steer, M. E. Bisher, and A. C. Steven. 1991. J. Struct.
Biol. 107:6-14), from which quantitative measures are obtained to support the
notion that the three arms of a triskelion have statistically identical
properties and exhibit independent structural fluctuations. Additionally, a study
of local contour fluctuations, which indicates that the elastic properties of a
triskelion arm are approximately constant over the entire arm length, is used
along with a small deformation statistical mechanics theory to derive an
effective, average flexural rigidity for the arms. This result is used to
estimate the bending energy necessary to deform a clathrin patch, and comparison
is made with the deformation energy of an equivalent area of non-clathrin-coated
membrane. We estimate that the rigidity of the clathrin lattice is at least
comparable to that of a typical membrane. Hence, the natural curvature of a
clathrin cage can stabilize, and perhaps propel, the formation of intracellular
coated vesicles.
PMID- 10692309
TI - Time and force dependence of the rupture of glycoprotein IIb-IIIa-fibrinogen
bonds between latex spheres.
AB - We studied the shear-induced breakup of doublets of aldehyde/sulfate (A/S) latex
spheres covalently linked with purified platelet GPIIb-IIIa receptor, and cross
linked by fibrinogen. Flow cytometry with fluorescein isothiocyanate-fibrinogen
showed than an average of 22,500 molecules of active GPIIb-IIIa were captured per
sphere, with a mean K(d) = 56 nM for fibrinogen binding. The spheres, suspended
in buffered 19% Ficoll 400 containing 120 or 240 pM fibrinogen, were subjected to
Couette flow in a counter-rotating cone-plate rheoscope. Doublets, formed by two
body collisions at low shear rate (G = 8 s(-1)) for < or =15 min, were subjected
to shear stress from 0.6 to 2.9 Nm(-2), their rotations recorded until they broke
up or were lost to view. Although breakup was time dependent, occurring mostly in
the first 2 rotations after the onset of shear, the percentage of doublets broken
up after 10 rotations were almost independent of normal hydrodynamic force, F(n):
at 240 pN, 15.6, 16.0, and 17.0% broke up in the force range 70-150 pN, 150-230
pN, and 230-310 pN. Unexpectedly, at both [fibrinogen], the initial rate of
breakup was highest in the lowest force range, and computer simulation using a
stochastic model of breakup was unable to simulate the time course of breakup.
When pre-sheared at low G for >15 min, no doublets broke up within 10 rotations
at 70 < F(n) < 310 pN; it required >3 min shear (>1110 rotations) at F(n) = 210
pN for significant breakup to occur. Other published work has shown that binding
of fibrinogen to GPIIb-IIIa immobilized on plane surfaces exhibits an initial
fast reversible process with relative low affinity succeeded by transformation of
GPIIb-IIIa to a stable high-affinity complex. We postulate that most doublet
breakups observed within 10 rotations were from a population of young doublets
having low numbers of bonds, by dissociation of the initial receptor complex
relatively unresponsive to force. The remaining, older doublets with GPIIb-IIIa
in the high-affinity complex were not broken up in the time or range of forces
studied.
PMID- 10692310
TI - Response kinetics of tethered Rhodobacter sphaeroides to changes in light
intensity.
AB - Rhodobacter sphaeroides can swim toward a wide range of attractants (a process
known as taxis), propelled by a single rotating flagellum. The reversals of motor
direction that cause tumbles in Eschericia coli taxis are replaced by brief motor
stops, and taxis is controlled by a complex sensory system with multiple
homologues of the E. coli sensory proteins. We tethered photosynthetically grown
cells of R. sphaeroides by their flagella and measured the response of the
flagellar motor to changes in light intensity. The unstimulated bias (probability
of not being stopped) was significantly larger than the bias of tethered E. coli
but similar to the probability of not tumbling in swimming E. coli. Otherwise,
the step and impulse responses were the same as those of tethered E. coli to
chemical attractants. This indicates that the single motor and multiple sensory
signaling pathways in R. sphaeroides generate the same swimming response as
several motors and a single pathway in E. coli, and that the response of the
single motor is directly observable in the swimming pattern. Photo-responses were
larger in the presence of cyanide or the uncoupler carbonyl cyanide 4
trifluoromethoxyphenylhydrazone (FCCP), consistent with the photo-response being
detected via changes in the rate of electron transport.
PMID- 10692311
TI - Direct observation of trapping and release of nitric oxide by glutathione and
cysteine with electron paramagnetic resonance spectroscopy.
AB - While the biosynthesis of nitric oxide (NO) is well established, one of the key
issues that remains to be solved is whether NO participates in the biological
responses right after generation through biosynthesis or there is a "secret
passage" via which NO itself is trapped, transported, and released to exert its
functions. It has been shown that NO reacts with thiol-containing biomolecules
(RSH), like cysteine (Cys), glutathione (GSH), etc., to form S-nitrosothiols
(RSNOs), which then release nitrogen compounds, including NO. The direct
observation of trapping of NO and its release by RSNO has not been well
documented, as most of the detection techniques measure the content of NO as well
as nitrite and nitrate. Here we use spin-trapping electron paramagnetic resonance
(EPR) technique to measure NO content directly in the reaction time course of
samples of GSH and Cys ( approximately mM) mixed with NO ( approximately microM)
in the presence of metal ion chelator, which pertains to physiological
conditions. We demonstrate that NO is readily trapped by these thiols in less
than 10 min and approximately 70-90% is released afterward. These data imply that
approximately 10-30% of the reaction product of NO does not exist in the free
radical form. The NO release versus time curves are slightly pH dependent in the
presence of metal ion chelator. Because GSH and Cys exist in high molar
concentrations in blood and in mammalian cells, the trapping and release passage
of NO by these thiols may provide a mechanism for temporal and spatial
sequestration of NO to overcome its concentration gradient-dependent diffusion,
so as to exert its multiple biological effects by reacting with various targets
through regeneration.
PMID- 10692312
TI - Coexpression of alpha and beta subunits of the rod cyclic GMP-gated channel
restores native sensitivity to cyclic AMP: role of D604/N1201.
AB - Coexpression of the betawt and alphawt subunits of the bovine rod channel
restores two characteristics of the native channels: higher sensitivity to cAMP
and potentiation of cGMP-induced currents by low cAMP concentrations. To test
whether the increased sensitivity to cAMP is due to the uncharged nature of the
asparagine residue (N1201) situated in place of aspartate D604 in the beta
subunit as previously suggested (, Neuron. 15:619-625), we compared currents from
wild-type (alphawt and alphawt/betawt) and from mutated channels (alphaD604N,
alphaD604N/betawt, and alphawt/betaN1201D). The results show that the sensitivity
to cAMP and cAMP potentiation is partly but not entirely determined by the charge
of residue 1201 in the beta subunit. The D604N mutation in the alpha subunit and,
to a lesser extent, coexpression of the betawt subunit with the alphawt subunit
reduce the open probability for cGMP compared to that of the alphawt channel.
Interpretation of the data with the MWC allosteric model (model of Monod, Wyman,
Changeux;, J. Mol. Biol. 12:88-118) suggests that the D604N mutation in the alpha
subunits and coassembly of alpha and beta subunits alter the free energy of
gating by cAMP more than that of cAMP binding.
PMID- 10692313
TI - Calcium currents in hair cells isolated from semicircular canals of the frog.
AB - L-type and R-type Ca(2+) currents were detected in frog semicircular canal hair
cells. The former was noninactivating and nifedipine-sensitive (5 microM); the
latter, partially inactivated, was resistant to omega-conotoxin GVIA (5 microM),
omega-conotoxin MVIIC (5 microM), and omega-agatoxin IVA (0.4 microM), but was
sensitive to mibefradil (10 microM). Both currents were sensitive to Ni(2+) and
Cd(2+) (>10 microM). In some cells the L-type current amplitude increased almost
twofold upon repetitive stimulation, whereas the R-type current remained
unaffected. Eventually, run-down occurred for both currents, but was prevented by
the protease inhibitor calpastatin. The R-type current peak component ran down
first, without changing its plateau, suggesting that two channel types generate
the R-type current. This peak component appeared at -40 mV, reached a maximal
value at -30 mV, and became undetectable for voltages > or =0 mV, suggestive of a
novel transient current: its inactivation was indeed reversibly removed when
Ba(2+) was the charge carrier. The L-type current and the R-type current plateau
were appreciable at -60 mV and peaked at -20 mV: the former current did not
reverse for voltages up to +60 mV, the latter reversed between +30 and +60 mV due
to an outward Cs(+) current flowing through the same Ca(2+) channel. The
physiological role of these currents on hair cell function is discussed.
PMID- 10692314
TI - Histidine(118) in the S2-S3 linker specifically controls activation of the KAT1
channel expressed in Xenopus oocytes.
AB - The guard cell K(+) channel KAT1, cloned from Arabidopsis thaliana, is activated
by hyperpolarization and regulated by a variety of physiological factors. Low
internal pH accelerated the activation kinetics of the KAT1 channel expressed in
Xenopus oocytes with a pK of approximately 6, similar to guard cells in vivo.
Mutations of histidine-118 located in the putative cytoplasmic linker between the
S2 and S3 segments profoundly affected the gating behavior and pH dependence. At
pH 7.2, substitution with a negatively charged amino acid (glutamate, aspartate)
specifically slowed the activation time course, whereas that with a positively
charged amino acid (lysine, arginine) accelerated. These mutations did not alter
the channel's deactivation time course or the gating behavior after the first
opening. Introducing an uncharged amino acid (alanine, asparagine) at position
118 did not have any obvious effect on the activation kinetics at pH 7.2. The
charged substitutions markedly decreased the sensitivity of the KAT1 channel to
internal pH in the physiological range. We propose a linear kinetic scheme to
account for the KAT1 activation time course at the voltages where the opening
transitions dominate. Changes in one forward rate constant in the model
adequately account for the effects of the mutations at position 118 in the S2-S3
linker segment. These results provide a molecular and biophysical basis for the
diversity in the activation kinetics of inward rectifiers among different plant
species.
PMID- 10692315
TI - Molecular cloning of cDNA encoding a drosophila ryanodine receptor and functional
studies of the carboxyl-terminal calcium release channel.
AB - Ryanodine is a plant alkaloid that was originally used as an insecticide. To
study the function and regulation of the ryanodine receptor (RyR) from insect
cells, we have cloned the entire cDNA sequence of RyR from the fruit fly
Drosophila melanogaster. The primary sequence of the Drosophila RyR contains 5134
amino acids, which shares approximately 45% identity with RyRs from mammalian
cells, with a large cytoplasmic domain at the amino-terminal end and a small
transmembrane domain at the carboxyl-terminal end. To characterize the Ca(2+)
release channel activity of the cloned Drosophila RyR, we expressed both full
length and a deletion mutant of Drosophila RyR lacking amino acids 277-3650
(Drosophila RyR-C) in Chinese hamster ovary cells. For subcellular localization
of the expressed Drosophila RyR and Drosophila RyR-C proteins, green fluorescent
protein (GFP)-Drosophila RyR and GFP-Drosophila RyR-C fusion constructs were
generated. Confocal microscopic imaging identified GFP-Drosophila RyR and GFP
Drosophila RyR-C on the endoplasmic reticulum membranes of transfected cells.
Upon reconstitution into the lipid bilayer membrane, Drosophila RyR-C formed a
large conductance cation-selective channel, which was sensitive to modulation by
ryanodine. Opening of the Drosophila RyR-C channel required the presence of
microM concentration of Ca(2+) in the cytosolic solution, but the channel was
insensitive to inhibition by Ca(2+) at concentrations as high as 20 mM. Our data
are consistent with our previous observation with the mammalian RyR that the
conduction pore of the calcium release channel resides within the carboxyl
terminal end of the protein and further demonstrate that structural and
functional features are essentially shared by mammalian and insect RyRs.
PMID- 10692316
TI - Functional expression of the L-type calcium channel in mice skeletal muscle
during prenatal myogenesis.
AB - The densities of skeletal muscle intramembrane charge movement and macroscopic L
type Ca(2+) current have been shown to increase during prenatal development. In
the present work, the electrophysiological characteristics of L-type Ca(2+)
channels were analyzed over the embryonic period E14 to E19 using the whole-cell
and cell-attached procedures. At the macroscopic level, the whole-cell L-type
Ca(2+) conductance increased 100% between E14 and E19. This enhancement was
accompanied by a small negative shift of the voltage dependence and a marked
acceleration of the inactivation kinetics. At the single-channel level, the
unitary conductance decreased significantly from 13.2 +/- 0.1 pS (n = 8) at E14
to 10.7 +/- 0.3 pS (n = 7) at E18 and the open probability was multiplied by 2.
No significant change of the density of functional channels was observed during
the same period. In contrast to the density of intramembrane charge movement,
which, under the same conditions, has been shown to increase between 16 and 19
days, L-type Ca(2+) channels properties change mostly between 14 and 16 days.
Taken together, these results suggest that the two functions of the
dihydropyridine receptor are carried by two different proteins which could be
differentially regulated by subunit composition and/or degree of phosphorylation.
PMID- 10692317
TI - Conformation, independent of charge, in the R domain affects cystic fibrosis
transmembrane conductance regulator channel openings.
AB - The R domain of cystic fibrosis transmembrane conductance regulator (CFTR), when
phosphorylated, undergoes conformational change, and the chloride channel opens.
We investigated the contribution of R domain conformation, apart from the changes
induced by phosphorylation, to channel opening, by testing the effect of the
peptidyl-prolyl isomerase, cyclophilin A, on the CFTR channel. When it was
applied after the channel had been opened by PKA phosphorylation, cyclophilin A
increased the open probability of wild-type CFTR (from P(o) = 0.197 +/- 0.010 to
P(o) = 0.436 +/- 0. 029) by increasing the number of channel openings, not open
time. Three highly conserved proline residues in the R domain, at positions 740,
750, and 759, were considered as candidate targets for cyclophilin A. Mutations
of these prolines to alanines (P3A mutant) resulted in a channel unresponsive to
cyclophilin A but with pore properties similar to the wild type, under strict
control of PKA and ATP, but with significantly increased open probability (P(o) =
0.577 +/- 0.090) compared to wild-type CFTR, again due to an increase in the
number of channel openings and not open time. Mutation of each of the proline
residues separately and in pairs demonstrated that all three proline mutations
are required for maximal P(o). When P3A was expressed in 293 HEK cells and tested
by SPQ assay, chloride efflux was significantly increased compared to cells
transfected with wild-type CFTR. Thus, treatments favoring the trans-peptidyl
conformation about conserved proline residues in the R domain of CFTR affect
openings of CFTR, above and beyond the effect of PKA phosphorylation.
PMID- 10692318
TI - Kinetics studies of the cardiac Ca-ATPase expressed in Sf21 cells: new insights
on Ca-ATPase regulation by phospholamban.
AB - Kinetics studies of the cardiac Ca-ATPase expressed in Sf21 cells (Spodoptera
frugiperda insect cells) have been carried out to test the hypotheses that
phospholamban inhibits Ca-ATPase cycling by decreasing the rate of the E1.Ca to
E1'.Ca transition and/or the rate of phosphoenzyme hydrolysis. Three sample types
were studied: Ca-ATPase expressed alone, Ca-ATPase coexpressed with wild-type
phospholamban (the natural pentameric inhibitor), and Ca-ATPase coexpressed with
the L37A-phospholamban mutant (a more potent monomeric inhibitor, in which
Leu(37) is replaced by Ala). Phospholamban coupling to the Ca-ATPase was
controlled using a monoclonal antibody against phospholamban. Gel electrophoresis
and immunoblotting confirmed an equivalent ratio of Ca-ATPase and phospholamban
in each sample (1 mol Ca-ATPase to 1.5 mol phospholamban). Steady-state ATPase
activity assays at 37 degrees C, using 5 mM MgATP, showed that the phospholamban
containing samples had nearly equivalent maximum activity ( approximately 0.75
micromol. nmol Ca-ATPase(-1).min(-1) at 15 microM Ca(2+)), but that wild-type
phospholamban and L37A-phospholamban increased the Ca-ATPase K(Ca) values by 200
nM and 400 nM, respectively. When steady-state Ca-ATPase phosphoenzyme levels
were measured at 0 degrees C, using 1 microM MgATP, the K(Ca) values also shifted
by 200 nM and 400 nM, respectively, similar to the results obtained by measuring
ATP hydrolysis at 37 degrees C. Measurements of the time course of phosphoenzyme
formation at 0 degrees C, using 1 microM MgATP and 268 nM ionized [Ca(2+)],
indicated that L37A-phospholamban decreased the steady-state phosphoenzyme level
to a greater extent (45%) than did wild-type phospholamban (33%), but neither
wild-type nor L37A-phospholamban had any effect on the apparent rate of
phosphoenzyme formation relative to that of Ca-ATPase expressed alone.
Measurements of inorganic phosphate (P(i)) release concomitant with the
phosphoenzyme formation studies showed that L37A-phospholamban decreased the
steady-state rate of P(i) release to a greater extent (45%) than did wild-type
phospholamban (33%). However, independent measurements of Ca-ATPase
dephosphorylation after the addition of 5 mM EGTA to the phosphorylated enzyme
showed that neither wild-type phospholamban nor L37A-phospholamban had any effect
on the rate of phosphoenzyme decay relative to Ca-ATPase expressed alone.
Computer simulation of the kinetics data indicated that phospholamban and L37A
phospholamban decreased twofold and fourfold, respectively, the equilibrium
binding of the first Ca(2+) ion to the Ca-ATPase E1 intermediate, rather than
inhibiting rate of the E.Ca to E'.Ca transition or the rate of phosphoenzyme
decay. Therefore, we conclude that phospholamban inhibits Ca-ATPase cycling by
decreasing Ca-ATPase Ca(2+) binding to the E1 intermediate.
PMID- 10692319
TI - Electrostatic interactions regulate desensitization of the nicotinic
acetylcholine receptor.
AB - To determine the importance of electrostatic interactions for agonist binding to
the nicotinic acetylcholine receptor (AChR), we examined the affinity of the
fluorescent agonist dansyl-C6-choline for the AChR. Increasing ionic strength
decreased the binding affinity in a noncompetitive manner and increased the Hill
coefficient of binding. Small cations did not compete directly for dansyl-C6
choline binding. The sensitivity to ionic strength was reduced in the presence of
proadifen, a noncompetitive antagonist that desensitizes the receptor. Moreover,
at low ionic strength, the dansyl-C6-choline affinities were similar in the
absence or presence of proadifen, a result consistent with the receptor being
desensitized at low ionic strength. Similar ionic strength effects were observed
for the binding of the noncompetitive antagonist [(3)H]ethidium when examined in
the presence and absence of agonist to desensitize the AChR. Therefore, ionic
strength modulates binding affinity through at least two mechanisms: by
influencing the conformation of the AChR and by electrostatic effects at the
binding sites. The results show that charge-charge interactions regulate the
desensitization of the receptor. Analysis of dansyl-C6-choline binding to the
desensitized conformation using the Debye-Huckel equation was consistent with the
presence of five to nine negative charges within 20 A of the acetylcholine
binding sites.
PMID- 10692320
TI - Protonation of lysine residues inverts cation/anion selectivity in a model
channel.
AB - A dimeric alamethicin analog with lysine at position 18 in the sequence (alm-K18)
was previously shown to form stable anion-selective channels in membranes at pH
7.0 [Starostin, A. V., R. Butan, V. Borisenko, D. A. James, H. Wenschuh, M. S.
Sansom, and G. A. Woolley. 1999. Biochemistry. 38:6144-6150]. To probe the charge
state of the conducting channel and how this might influence cation versus anion
selectivity, we performed a series of single-channel selectivity measurements at
different pH values. At pH 7.0 and below, only anion-selective channels were
found with P(K(+))/P(Cl(-)) = 0. 25. From pH 8-10, a mixture of anion-selective,
non-selective, and cation-selective channels was found. At pH > 11 only cation
selective channels were found with P(K(+))/P(Cl(-)) = 4. In contrast, native
alamethicin-Q18 channels (with Gln in place of Lys at position 18) were cation
selective (P(K(+))/P(Cl(-)) = 4) at all pH values. Continuum electrostatics
calculations were then carried out using an octameric model of the alm-K18
channel embedded in a low dielectric slab to simulate a membrane. Although the
calculations can account for the apparent pK(a) of the channel, they fail to
correctly predict the degree of selectivity. Although a switch from cation- to
anion-selectivity as the channel becomes protonated is indicated, the degree of
anion-selectivity is severely overestimated, suggesting that the continuum
approach does not adequately represent some aspect of the electrostatics of
permeation in these channels. Side-chain conformational changes upon protonation,
conformational changes, and deprotonation caused by permeating cations and
counterion binding by lysine residues upon protonation are considered as possible
sources of the overestimation.
PMID- 10692321
TI - Amino acid residues 4425-4621 localized on the three-dimensional structure of the
skeletal muscle ryanodine receptor.
AB - We have localized a region contained within the sequence of amino acid residues
4425-4621 on the three-dimensional structure of the skeletal muscle ryanodine
receptor (RyR). Mouse monoclonal antibodies raised against a peptide comprising
these residues have been complexed with ryanodine receptors and imaged in the
frozen-hydrated state by cryoelectron microscopy. These images, along with images
of antibody-free ryanodine receptor, were used to compute two-dimensional
averaged images and three-dimensional reconstructions. Two-dimensional averages
of immunocomplexes in which the ryanodine receptor was in the fourfold
symmetrical orientation disclosed four symmetrical regions of density located on
the edges of the receptor's cytoplasmic assembly that were absent from control
averages of receptor without added antibody. Three-dimensional reconstructions
revealed the antibody-binding sites to be on the so-called handle domains of the
ryanodine receptor's cytoplasmic assembly, near their junction with the
transmembrane assembly. This study is the first to demonstrate epitope mapping on
the three-dimensional structure of the ryanodine receptor.
PMID- 10692322
TI - Protein-induced membrane disorder: a molecular dynamics study of melittin in a
dipalmitoylphosphatidylcholine bilayer.
AB - A molecular dynamics simulation of melittin in a hydrated
dipalmitoylphosphatidylcholine (DPPC) bilayer was performed. The 19, 000-atom
system included a 72-DPPC phospholipid bilayer, a 26-amino acid peptide, and more
than 3000 water molecules. The N-terminus of the peptide was protonated and
embedded in the membrane in a transbilayer orientation perpendicular to the
surface. The simulation results show that the peptide affects the lower
(intracellular) layer of the bilayer more strongly than the upper (extracellular)
layer. The simulation results can be interpreted as indicating an increased level
of disorder and structural deformation for lower-layer phospholipids in the
immediate vicinity of the peptide. This conclusion is supported by the calculated
deuterium order parameters, the observed deformation at the intracellular
interface, and an increase in fractional free volume. The upper layer was less
affected by the embedded peptide, except for an acquired tilt relative to the
bilayer normal. The effect of melittin on the surrounding membrane is localized
to its immediate vicinity, and its asymmetry with respect to the two layers may
result from the fact that it is not fully transmembranal. Melittin's hydrophilic
C-terminus anchors it at the extracellular interface, leaving the N-terminus
"loose" in the lower layer of the membrane. In general, the simulation supports a
role for local deformation and water penetration in melittin-induced lysis. As
for the peptide, like other membrane-embedded polypeptides, melittin adopts a
significant 25 degree tilt relative to the membrane normal. This tilt is
correlated with a comparable tilt of the lipids in the upper membrane layer. The
peptide itself retains an overall helical structure throughout the simulation
(with the exception of the three N-terminal residues), adopting a 30 degree
intrahelical bend angle.
PMID- 10692323
TI - Cholesterol effects on the phosphatidylcholine bilayer polar region: a molecular
simulation study.
AB - A molecular dynamics (MD) simulation of a fully hydrated, liquid-crystalline
dimyristoylphosphatidylcholine (DMPC)-Chol bilayer membrane containing
approximately 22 mol% Chol was carried out for 4.3 ns. The bilayer reached
thermal equilibrium after 2.3 ns of MD simulation. A 2.0-ns trajectory generated
during 2.3-4.3 ns of MD simulation was used for analyses to determine the effects
of Chol on the membrane/water interfacial region. In this region, 70% of Chol
molecules are linked to DMPC molecules via short-distance interactions, where the
Chol hydroxyl group (OH-Chol) is 1) charge paired to methyl groups of the DMPC
choline moiety ( approximately 34%), via the hydroxyl oxygen atom (Och); 2) water
bridged to carbonyl ( approximately 19%) and nonester phosphate ( approximately
14%) oxygen atoms, via both Och and the hydroxyl hydrogen atom (Hch); and 3)
directly hydrogen (H) bonded to carbonyl ( approximately 11%) and nonester
phosphate ( approximately 5%) oxygen atoms, via Hch ( approximately 17% of DMPC
Chol links are multiple). DMPC's gamma-chain carbonyl oxygen atom is involved in
44% of water bridges and 51% of direct H bonds formed between DMPC and Chol. On
average, a Chol molecule forms 0.9 links with DMPC molecules, while a DMPC
molecule forms 2.2 and 0.3 links with DMPC and Chol molecules, respectively. OH
Chol makes hydrogen bonds with 1.1 water molecules, preferentially via Hch. The
average number of water molecules H bonded to the DMPC headgroup is increased by
7% in the presence of Chol. These results indicate that inclusion of Chol
decreases interlipid links and increases hydration in the polar region of the
membrane.
PMID- 10692324
TI - Studies of archaebacterial bipolar tetraether liposomes by perylene fluorescence.
AB - Membrane packing and dynamics of bipolar tetraether liposomes composed of the
polar lipid fraction E (PLFE) from the thermoacidophilic archaebacterium
Sulfolobus acidocaldarius have been studied by perylene fluorescence. At a probe
to-PLFE lipid ratio of 1:400, we have detected an unusual fluorescence intensity
increase with increasing temperature, while the fluorescence lifetime changed
little. As the ratio was decreased, the intensity anomaly was diminished. At
1:3200 and 1:6400, the anomaly disappeared. A remarkable perylene intensity
anomaly was also observed in bilayers composed of saturated monopolar diester
phosphatidylcholines at their main phase transition temperatures. These results
suggest that the intensity anomaly may be due to probe aggregation caused by
tight membrane packing. At the same probe-to-lipid ratio (1:400), however, 1, 2
diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) and 1, 2-diphytanoyl-sn-glycero-3
phosphoglycerol (DPhPG) liposomes did not exhibit any intensity anomaly with
increasing temperature. This suggests that DPhPC and DPhPG liposomes are more
loosely packed than PLFE liposomes; thus the branched methyl groups are not the
contributing factor of the tight membrane packing found in PLFE liposomes. Using
a multiexcitation method, we have also determined the average (R), in-plane
(R(ip)), and out-of-plane (R(op)) rotational rates of perylene in PLFE liposomes
at various temperatures (20-65 degrees C). R and R(ip), determined at two
different probe-to-lipid ratios (1:400 and 1:3200), both undergo an abrupt
increase when the temperature is elevated to approximately 48 degrees C. These
data suggest that PLFE liposomes are rigid and tightly packed at low
temperatures, but they begin to possess appreciable "membrane fluidity" at
temperatures close to the minimum growth temperature ( approximately 50 degrees
C) of thermoacidophilic archaebacteria.
PMID- 10692325
TI - Interaction of phosphatidylserine synthase from E. coli with lipid bilayers:
coupled plasmon-waveguide resonance spectroscopy studies.
AB - The interaction of phosphatidylserine (PS) synthase from Escherichia coli with
lipid membranes was studied with a recently developed variant of the surface
plasmon resonance technique, referred to as coupled plasmon-waveguide resonance
spectroscopy. The features of the new technique are increased sensitivity and
spectral resolution, and a unique ability to directly measure the structural
anisotropy of lipid and proteolipid films. Solid-supported lipid bilayers with
the following compositions were used: 1-palmitoyl-2-oleoyl-sn-glycero-3
phosphocholine (POPC); POPC-1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (POPA)
(80:20, mol/mol); POPC-POPA (60:40, mol/mol); and POPC-1-palmitoyl-2-oleoyl-sn
glycero-3-[phospho-rac-(1-glycerol)] (POPG) (75:25, mol/mol). Addition of either
POPA or POPG to a POPC bilayer causes a considerable increase of both the bilayer
thickness and its optical anisotropy. PS synthase exhibits a biphasic interaction
with the bilayers. The first phase, occurring at low protein concentrations,
involves both electrostatic and hydrophobic interactions, although it is
dominated by the latter, and the enzyme causes a local decrease of the ordering
of the lipid molecules. The second phase, occurring at high protein
concentrations, is predominantly controlled by electrostatic interactions, and
results in a cooperative binding of the enzyme to the membrane surface. Addition
of the anionic lipids to a POPC bilayer causes a 5- to 15-fold decrease in the
protein concentration at which the first binding phase occurs. The results
reported herein lend experimental support to a previously suggested mechanism for
the regulation of the polar head group composition in E. coli membranes.
PMID- 10692326
TI - Kinetic and structural study of the interaction of myelin basic protein with
dipalmitoylphosphatidylglycerol layers.
AB - The interaction of myelin basic protein (MBP) with
dipalmitoylphosphatidylglycerol films has been investigated by means of a
microgravimetric gauge sensitive to the changes in load and structural
modifications of the layer deposited onto its surface. Fourier transform infrared
spectroscopy, circular dichroism, and x-ray diffraction have confirmed protein
uptake by the lipid phase along with a global disordering effect onto the lipid
alkyl chains and have shown a temporal evolution of the structure of water
penetrating the lipid phase together with the protein. These effects are clearly
related to the temporal variation of the microgravimetric gauge signal. Finally,
measurements carried out on pre-annealed samples point out the role of mesoscopic
morphology in determining the pathways through which MBP penetrates the lipid
multilayer. The results obtained in our model system could be useful in
clarifying the mechanisms of the myelinating and demyelinating processes that
take place in the natural membrane.
PMID- 10692327
TI - Molecular and mesoscopic properties of hydrophilic polymer-grafted phospholipids
mixed with phosphatidylcholine in aqueous dispersion: interaction of dipalmitoyl
N-poly(ethylene glycol)phosphatidylethanolamine with
dipalmitoylphosphatidylcholine studied by spectrophotometry and spin-label
electron spin resonance.
AB - Spin-label electron spin resonance (ESR) spectroscopy, together with optical
density measurements, has been used to investigate, at both the molecular and
supramolecular levels, the interactions of N-poly(ethylene glycol)
phosphatidylethanolamines (PEG-PE) with phosphatidylcholine (PC) in aqueous
dispersions. PEG-PEs are micelle-forming hydrophilic polymer-grafted lipids that
are used extensively for steric stabilization of PC liposomes to increase their
lifetimes in the blood circulation. All lipids had dipalmitoyl (C16:0) chains,
and the polymer polar group of the PEG-PE lipids had a mean molecular mass of
either 350 or 2000 Da. PC/PEG-PE mixtures were investigated over the entire range
of relative compositions. Spin-label ESR was used quantitatively to investigate
bilayer-micelle conversion with increasing PEG-PE content by measurements at
temperatures for which the bilayer membrane component of the mixture was in the
gel phase. Both saturation transfer ESR and optical density measurements were
used to obtain information on the dependence of lipid aggregate size on PEG-PE
content. It is found that the stable state of lipid aggregation is strongly
dependent not only on PEG-PE content but also on the size of the hydrophilic
polar group. These biophysical properties may be used for optimized design of
sterically stabilized liposomes.
PMID- 10692328
TI - The effect of removing the N-terminal extension of the Drosophila myosin
regulatory light chain upon flight ability and the contractile dynamics of
indirect flight muscle.
AB - The Drosophila myosin regulatory light chain (DMLC2) is homologous to MLC2s of
vertebrate organisms, except for the presence of a unique 46-amino acid N
terminal extension. To study the role of the DMLC2 N-terminal extension in
Drosophila flight muscle, we constructed a truncated form of the Dmlc2 gene
lacking amino acids 2-46 (Dmlc2(Delta2-46)). The mutant gene was expressed in
vivo, with no wild-type Dmlc2 gene expression, via P-element-mediated germline
transformation. Expression of the truncated DMLC2 rescues the recessive lethality
and dominant flightless phenotype of the Dmlc2 null, with no discernible effect
on indirect flight muscle (IFM) sarcomere assembly. Homozygous Dmlc2(Delta2-46)
flies have reduced IFM dynamic stiffness and elastic modulus at the frequency of
maximum power output. The viscous modulus, a measure of the fly's ability to
perform oscillatory work, was not significantly affected in Dmlc2(Delta2-46) IFM.
In vivo flight performance measurements of Dmlc2(Delta2-46) flies using a visual
closed-loop flight arena show deficits in maximum metabolic power (P(*)(CO(2))),
mechanical power (P(*)(mech)), and flight force. However, mutant flies were
capable of generating flight force levels comparable to body weight, thus
enabling them to fly, albeit with diminished performance. The reduction in
elastic modulus in Dmlc2(Delta2-46) skinned fibers is consistent with the N
terminal extension being a link between the thick and thin filaments that is
parallel to the cross-bridges. Removal of this parallel link causes an
unfavorable shift in the resonant properties of the flight system, thus leading
to attenuated flight performance.
PMID- 10692329
TI - Dynamics at Lys-553 of the acto-myosin interface in the weakly and strongly bound
states.
AB - Lys-553 of skeletal muscle myosin subfragment 1 (S1) was specifically labeled
with the fluorescent probe FHS (6-[fluorescein-5(and 6)-carboxamido]hexanoic acid
succinimidyl ester) and fluorescence quenching experiments were carried out to
determine the accessibility of this probe at Lys-553 in both the strongly and
weakly actin-bound states of the MgATPase cycle. Solvent quenchers of varying
charge [nitromethane, (2,2,6, 6-tetramethyl-1-piperinyloxy) (TEMPO), iodide (I(
)), and thallium (Tl(+))] were used to assess both the steric and electrostatic
accessibilities of the FHS probe at Lys-553. In the strongly bound rigor
(nucleotide-free) and MgADP states, actin offered no protection from solvent
quenching of FHS by nitromethane, TEMPO, or thallium, but did decrease the Stern
Volmer constant by almost a factor of two when iodide was used as the quencher.
The protection from iodide quenching was almost fully reversed with the addition
of 150 mM KCl, suggesting this effect is ionic in nature rather than steric.
Conversely, actin offered no protection from iodide quenching at low ionic
strength during steady-state ATP hydrolysis, even with a significant fraction of
the myosin heads bound to actin. Thus, the lower 50 kD subdomain of myosin
containing Lys-553 appears to interact differently with actin in the weakly and
strongly bound states.
PMID- 10692330
TI - Detection of fluorescently labeled actin-bound cross-bridges in actively
contracting myofibrils.
AB - Myosin subfragment 1 (S1) can be specifically modified at Lys-553 with the
fluorescent probe FHS (6-[fluorescein-5(and 6)-carboxamido]hexanoic acid
succinimidyl ester) (Bertrand, R., J. Derancourt, and R. Kassab. 1995.
Biochemistry. 34:9500-9507), and solvent quenching of FHS-S1 with iodide has been
shown to be sensitive to actin binding at low ionic strength (MacLean, Chrin, and
Berger, 2000. Biophys. J. 000-000). In order to extend these results and examine
the fraction of actin-bound myosin heads within the myofilament lattice during
calcium activation, we have modified skeletal muscle myofibrils, mildly cross
linked with EDC (1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide) to prevent
shortening, with FHS. The myosin heavy chain appears to be the predominant site
of labeling, and the iodide quenching patterns are consistent with those obtained
for myosin S1 in solution, suggesting that Lys-553 is indeed the primary site of
FHS incorporation in skeletal muscle myofibrils. The iodide quenching results
from calcium-activated FHS-myofibrils indicate that during isometric contraction
29% of the myosin heads are strongly bound to actin within the myofilament
lattice at low ionic strength. These results suggest that myosin can be
specifically modified with FHS in more complex and physiologically relevant
preparations, allowing the real time examination of cross-bridge interactions
with actin in in vitro motility assays and during isometric and isotonic
contractions within single muscle fibers.
PMID- 10692331
TI - Cross-bridge attachment during high-speed active shortening of skinned fibers of
the rabbit psoas muscle: implications for cross-bridge action during maximum
velocity of filament sliding.
AB - To characterize the kinetics of cross-bridge attachment to actin during unloaded
contraction (maximum velocity of filament sliding), ramp-shaped stretches with
different stretch-velocities (2-40,000 nm per half-sarcomere per s) were applied
to actively contracting skinned fibers of the rabbit psoas muscle. Apparent fiber
stiffness observed during such stretches was plotted versus the speed of the
imposed stretch (stiffness-speed relation) to derive the rate constants for cross
bridge dissociation from actin. The stiffness-speed relation obtained for
unloaded shortening conditions was shifted by about two orders of magnitude to
faster stretch velocities compared to isometric conditions and was almost
identical to the stiffness-speed relation observed in the presence of MgATPgammaS
at high Ca(2+) concentrations, i.e., under conditions where cross-bridges are
weakly attached to the fully Ca(2+) activated thin filaments. These data together
with several control experiments suggest that, in contrast to previous
assumptions, most of the fiber stiffness observed during high-speed shortening
results from weak cross-bridge attachment to actin. The fraction of strongly
attached cross-bridges during unloaded shortening appears to be as low as some 1
5% of the fraction present during isometric contraction. This is about an order
of magnitude less than previous estimates in which contribution of weak cross
bridge attachment to observed fiber stiffness was not considered. Our findings
imply that 1) the interaction distance of strongly attached cross-bridges during
high-speed shortening is well within the range consistent with conventional cross
bridge models, i.e., that no repetitive power strokes need to be assumed, and 2)
that a significant part of the negative forces that limit the maximum speed of
filament sliding might originate from weak cross-bridge interactions with actin.
PMID- 10692332
TI - CaATP as a substrate to investigate the myosin lever arm hypothesis of force
generation.
AB - In an effort to test the lever arm model of force generation, the effects of
replacing magnesium with calcium as the ATP-chelated divalent cation were
determined for several myosin and actomyosin reactions. The isometric force
produced by glycerinated muscle fibers when CaATP is the substrate is 20% of the
value obtained with MgATP. For myosin subfragment 1 (S1), the degree of lever arm
rotation, determined using transient electric birefringence to measure rates of
rotational Brownian motion in solution, is not significantly changed when calcium
replaces magnesium in an S1-ADP-vanadate complex. Actin activates S1 CaATPase
activity, although less than it does MgATPase activity. The increase in actin
affinity when S1. CaADP. P(i) is converted to S1. CaADP is somewhat greater than
it is for the magnesium case. The ionic strength dependence of actin binding
indicates that the change in apparent electrostatic charge at the acto-S1
interface for the S1. CaADP. P(i) to S1. CaADP step is similar to the change when
magnesium is bound. In general, CaATP is an inferior substrate compared to MgATP,
but all the data are consistent with force production by a lever arm mechanism
for both substrates. Possible reasons for the reduced magnitude of force when
CaATP is the substrate are discussed.
PMID- 10692333
TI - Structural implications of the chemical modification of Cys(10) on actin.
AB - Cys(10) is located in subdomain 1 of actin, which has an important role in the
interaction of actin with myosin- and actin-binding proteins. Cys(10) was
modified with fluorescence probes N-(iodoacetyl)N'-(5-sulfo-1-naphthyl)ethylene
diamine (IAEDANS), 7-diethylamino-3-(4'-maleimidylphenyl)-4-methylcoumarin (CPM),
or monobromo bimane (MBB) by the method of, J. Biol. Chem. 266:5508-5513). The
specificity of Cys(10) modification was verified by showing that the 33-kDa
subtilisin fragment of actin (residues 48-375), which contains all of the actin
thiols but Cys(10), is not fluorescent. Cys(10) modification exposed a new site
on actin to subtilisin cleavage. Edman degradation revealed this site to be
between Ala(19) and Gly(20). The modification slightly increased the rate of
epsilonATP-ATP exchange and decreased the rates of G-actin ATPase and
polymerization. The activation of S1 ATPase by Cys(10)-modified F-actin showed
small probe-dependent changes in the values of V(max) and K(M). The sliding speed
of actin filaments in the in vitro motility assay remained unchanged upon
modification of Cys(10). These results indicate that although the labeling of
Cys(10) perturbs the structure of subdomain 1, the modified actin remains fully
functional. The binding of S1 to actin filaments decreases the accessibility of
Cys(10) probes to acrylamide and nitromethane quenchers. Because Cys(10) does not
participate directly in either actin polymerization or S1 binding, our results
indicate that actin-actin and actin-myosin interactions induce dynamic,
allosteric changes in actin structure.
PMID- 10692334
TI - Morphology and transverse stiffness of Drosophila myofibrils measured by atomic
force microscopy.
AB - Atomic force microscopy was used to investigate the surface morphology and
transverse stiffness of myofibrils from Drosophila indirect flight muscle exposed
to different physiologic solutions. I- and A-bands were clearly observed, and
thick filaments were resolved along the periphery of the myofibril. Interfilament
spacings correlated well with estimates from previous x-ray diffraction studies.
Transverse stiffness was measured by using a blunt tip to indent a small section
of the myofibrillar surface in the region of myofilament overlap. At 10 nm
indention, the effective transverse stiffness (K( perpendicular)) of myofibrils
in rigor solution (ATP-free, pCa 4.5) was 10.3 +/- 5.0 pN nm(-1) (mean +/- SEM, n
= 8); in activating solution (pCa 4.5), 5.9 +/- 3.1 pN nm(-1); and in relaxing
solution (pCa 8), 4.4 +/- 2.0 pN nm(-1). The apparent transverse Young's modulus
(E( perpendicular)) was 94 +/- 41 kPa in the rigor state and 40 +/- 17 kPa in the
relaxed state. The value of E( perpendicular) for calcium-activated myofibrils
(55 +/- 29 kPa) was approximately a tenth that of Young's modulus in the
longitudinal direction, a difference that at least partly reflects the transverse
flexibility of the myosin molecule.
PMID- 10692335
TI - Dynamic bending rigidity of a 200-bp DNA in 4 mM ionic strength: a transient
polarization grating study.
AB - DNA may exhibit three different kinds of bends: 1) permanent bends; 2) slowly
relaxing bends due to fluctuations in a prevailing equilibrium between
differently curved secondary conformations; and 3) rapidly relaxing dynamic bends
within a single potential-of-mean-force basin. The dynamic bending rigidity
(kappa(d)), or equivalently the dynamic persistence length, P(d) =
kappa(d)/k(B)T, governs the rapidly relaxing bends, which are responsible for the
flexural dynamics of DNA on a short time scale, t < or = 10(-5) s. However, all
three kinds of bends contribute to the total equilibrium persistence length,
P(tot), according to 1/P(tot) congruent with 1/P(pb) + 1/P(sr) + 1/P(d), where
P(pb) is the contribution of the permanent bends and P(sr) is the contribution of
the slowly relaxing bends. Both P(d) and P(tot) are determined for the same 200
bp DNA in 4 mM ionic strength by measuring its optical anisotropy, r(t), from 0
to 10 micros. Time-resolved fluorescence polarization anisotropy (FPA)
measurements yield r(t) for DNA/ethidium complexes (1 dye/200 bp) from 0 to 120
ns. A new transient polarization grating (TPG) experiment provides r(t) for
DNA/methylene blue complexes (1 dye/100 bp) over a much longer time span, from 20
ns to 10 micros. Accurate data in the very tail of the decay enable a model
independent determination of the relaxation time (tau(R)) of the end-over-end
tumbling motion, from which P(tot) = 500 A is estimated. The FPA data are used to
obtain the best-fit pairs of P(d) and torsion elastic constant (alpha) values
that fit those data equally well, and which are used to eliminate alpha as an
independent variable. When the relevant theory is fitted to the entire TPG signal
(S(t)), the end-over-end rotational diffusion coefficient is fixed at its
measured value and alpha is eliminated in favor of P(d). Neither a true minimum
in chi-squared nor a satisfactory fit could be obtained for P(d) anywhere in the
range 500-5000 A, unless an adjustable amplitude of azimuthal wobble of the
methylene blue was admitted. In that case, a well-defined global minimum and a
reasonably good fit emerged at P(d) = 2000 A and (1/2) = 25
degrees. The discrimination against P(d) values <1600 A is very great. By
combining the values, P(tot) = 500 A and P(d) = 2000 A with a literature
estimate, P(pb) = 1370 A, a value P(sr) = 1300 A is estimated for the
contribution of slowly relaxing bends. This value is analyzed in terms of a
simple model in which the DNA is divided up into domains containing m bp, each of
which experiences an all-or-none equilibrium between a straight and a uniformly
curved conformation. With an appropriate estimate of the average bend angle per
basepair of the curved conformation, a lower bound estimate, m = 55 bp, is
obtained for the domain size of the coherently bent state. Previous measurements
suggest that this coherent bend is not directional, or phase-locked, to the
azimuthal orientation of the filament.
PMID- 10692336
TI - Unraveling photoexcited conformational changes of bacteriorhodopsin by time
resolved electron paramagnetic resonance spectroscopy.
AB - By means of time-resolved electron paramagnetic resonance (EPR) spectroscopy, the
photoexcited structural changes of site-directed spin-labeled bacteriorhodopsin
are studied. A complete set of cysteine mutants of the C-D loop, positions 100
107, and of the E-F loop, including the first alpha-helical turns of helices E
and F, positions 154-171, was modified with a methanethiosulfonate spin label.
The EPR spectral changes occurring during the photocycle are consistent with a
small movement of helix C and an outward tilt of helix F. These helix movements
are accompanied by a rearrangement of the E-F loop and of the C-terminal turn of
helix E. The kinetic analysis of the transient EPR data and the absorbance
changes in the visible spectrum reveals that the conformational change occurs
during the lifetime of the M intermediate. Prominent rearrangements of nitroxide
side chains in the vicinity of D96 may indicate the preparation of the
reprotonation of the Schiff base. All structural changes reverse with the
recovery of the bacteriorhodopsin initial state.
PMID- 10692337
TI - Structural changes of the sarcoplasmic reticulum Ca(2+)-ATPase upon nucleotide
binding studied by fourier transform infrared spectroscopy.
AB - Changes in the vibrational spectrum of the sarcoplasmic reticulum Ca(2+)-ATPase
upon nucleotide binding were recorded in H(2)O and (2)H(2)O at -7 degrees C and
pH 7.0. The reaction cycle was triggered by the photochemical release of
nucleotides (ATP, ADP, and AMP-PNP) from a biologically inactive precursor (caged
ATP, P(3)-1-(2-nitrophenyl) adenosine 5'-triphosphate, and related caged
compounds). Infrared absorbance changes due to ATP release and two steps of the
Ca(2+)-ATPase reaction cycle, ATP binding and phosphorylation, were followed in
real time. Under the conditions used in our experiments, the rate of ATP binding
was limited by the rate of ATP release (k(app) congruent with 3 s(-1) in H(2)O
and k(app) congruent with 7 s(-1) in (2)H(2)O). Bands in the amide I and II
regions of the infrared spectrum show that the conformation of the Ca(2+)-ATPase
changes upon nucleotide binding. The observation of bands in the amide I region
can be assigned to perturbations of alpha-helical and beta-sheet structures.
According to similar band profiles in the nucleotide binding spectra, ATP, AMP
PNP, and ADP induce similar conformational changes. However, subtle differences
between ATP and AMP-PNP are observed; these are most likely due to the
protonation state of the gamma-phosphate group. Differences between the ATP and
ADP binding spectra indicate the significance of the gamma-phosphate group in the
interactions between the Ca(2+)-ATPase and the nucleotide. Nucleotide binding
affects Asp or Glu residues, and bands characteristic of their protonated side
chains are observed at 1716 cm(-1) (H(2)O) and 1706 cm(-1) ((2)H(2)O) and seem to
depend on the charge of the phosphate groups. Bands at 1516 cm(-1) (H(2)O) and
1514 cm(-1) ((2)H(2)O) are tentatively assigned to a protonated Tyr residue
affected by nucleotide binding. Possible changes in Arg, Trp, and Lys absorption
and in the nucleoside are discussed. The spectra are compared with those of
nucleotide binding to arginine kinase, creatine kinase, and H-ras P21.
PMID- 10692338
TI - Induced fit in arginine kinase.
AB - Creatine kinase (CK) and arginine kinase (AK) are related enzymes that reversibly
transfer a phosphoryl group between a guanidino compound and ADP. In the
buffering of ATP energy levels, they are central to energy metabolism and have
been paradigms of classical enzymology. Comparison of the open substrate-free
structure of CK and the closed substrate-bound structure of AK reveals
differences that are consistent with prior biophysical evidence of substrate
induced conformational changes. Large and small domains undergo a hinged 13
degrees rotation. Several loops become ordered and adopt different positions in
the presence of substrate, including one (residues 309-319) that moves 15 A to
fold over the substrates. The conformational changes appear to be necessary in
aligning the two substrates for catalysis, in configuring the active site only
when productive phosphoryl transfer is possible, and excluding water from the
active site to avoid wasteful ATP hydrolysis.
PMID- 10692339
TI - Properties and crystal structure of a beta-barrel folding mutant.
AB - A mutant of a beta-barrel protein, rat intestinal fatty acid binding protein, was
predicted to be more stable than the wild-type protein due to a novel hydrogen
bond. Equilibrium denaturation studies indicated the opposite: the V60N mutant
protein was less stable. The folding transitions followed by CD and fluorescence
were reversible and two-state for both mutant and wild-type protein. However, the
rates of denaturation and renaturation of V60N were faster. During unfolding, the
initial rate was associated with 75-80% of the fluorescence and all of the CD
amplitude change. A subsequent rate accounted for the remaining fluorescence
change for both proteins; thus the intermediate state lacked secondary structure.
During folding, one rate was detected by both fluorescence and CD after an
initial burst phase for both wild-type and mutant. An additional slower folding
rate was detected by fluorescence for the mutant protein. The structure of the
V60N mutant has been obtained and is nearly identical to prior crystal structures
of IFABP. Analysis of mean differences in hydrogen bond and van der Waals
interactions did not readily account for the stability loss due to the mutation.
However, significant average differences of the solvent accessible surface and
crystallographic displacement factors suggest entropic destabilization.
PMID- 10692340
TI - Spectral fluctuation of a single fluorophore conjugated to a protein molecule.
AB - We have measured the fluorescence spectra of a single fluorophore attached to a
single protein molecule in aqueous solution using a total internal reflection
fluorescence microscope. The most reactive cysteine residue of myosin subfragment
1 (S1) was labeled with tetramethylrhodamine. The spectral shift induced by a
change in solvent from aqueous buffer to methanol in both single-molecule and
bulk measurements were similar, indicating that, even at the single molecule
level, the fluorescence spectrum is sensitive to microenvironmental changes of
fluorophores. The time dependence of the fluorescence spectra of fluorophores
attached to S1 molecules solely showed a fluctuation with time over a time scale
of seconds. Because the fluorescence spectra of the same fluorophores directly
conjugated to a glass surface remained constant, the spectral fluctuation
observed for the fluorophores attached to S1 is most likely due to slow
spontaneous conformational changes in the S1 molecule. Thus, single-molecule
fluorescence spectroscopy appears to be a powerful tool to study the dynamic
behavior of single biomolecules.
PMID- 10692341
TI - Spectroscopy of individual light-harvesting 2 complexes of Rhodopseudomonas
acidophila: diagonal disorder, intercomplex heterogeneity, spectral diffusion,
and energy transfer in the B800 band.
AB - This paper reports a detailed spectroscopic study of the B800 absorption band of
individual light-harvesting 2 (LH2) complexes of the photosynthetic purple
bacterium Rhodopseudomonas acidophila at 1. 2 K. By applying single-molecule
detection techniques to this system, details and properties can be revealed that
remain obscured in conventional ensemble experiments. For instance, from
fluorescence-excitation spectra of the individual complexes a more direct measure
of the diagonal disorder could be obtained. Further spectral diffusion phenomena
and homogeneous linewidths of individual bacteriochlorophyll a (BChl a) molecules
are observed, revealing valuable information on excited-state dynamics. This work
demonstrates that it is possible to obtain detailed spectral information on
individual pigment-protein complexes, providing direct insight into their
electronic structure and into the mechanisms underlying the highly efficient
energy transfer processes in these systems.
PMID- 10692342
TI - Scanning electrochemical microscopy as a local probe of oxygen permeability in
cartilage.
AB - The use of scanning electrochemical microscopy, a high-resolution chemical
imaging technique, to probe the distribution and mobility of solutes in articular
cartilage is described. In this application, a mobile ultramicroelectrode is
positioned close ( approximately 1 microm) to the cartilage sample surface, which
has been equilibrated in a bathing solution containing the solute of interest.
The solute is electrolyzed at a diffusion-limited rate, and the current response
measured as the ultramicroelectrode is scanned across the sample surface. The
topography of the samples was determined using Ru(CN)(6)(4-), a solute to which
the cartilage matrix was impermeable. This revealed a number of pit-like
depressions corresponding to the distribution of chondrocytes, which were also
observed by atomic force and light microscopy. Subsequent imaging of the same
area of the cartilage sample for the diffusion-limited reduction of oxygen
indicated enhanced, but heterogeneous, permeability of oxygen across the
cartilage surface. In particular, areas of high permeability were observed in the
cellular and pericellular regions. This is the first time that inhomogeneities in
the permeability of cartilage toward simple solutes, such as oxygen, have been
observed on a micrometer scale.
PMID- 10692343
TI - One- and two-photon excited fluorescence lifetimes and anisotropy decays of green
fluorescent proteins.
AB - We have used one- (OPE) and two-photon (TPE) excitation with time-correlated
single-photon counting techniques to determine time-resolved fluorescence
intensity and anisotropy decays of the wild-type Green Fluorescent Protein (GFP)
and two red-shifted mutants, S65T-GFP and RSGFP. WT-GFP and S65T-GFP exhibited a
predominant approximately 3 ns monoexponential fluorescence decay, whereas for
RSGFP the main lifetimes were approximately 1.1 ns (main component) and
approximately 3.3 ns. The anisotropy decay of WT-GFP and S65T-GFP was also
monoexponential (global rotational correlation time of 16 +/- 1 ns). The
approximately 1.1 ns lifetime of RSGFP was associated with a faster rotational
depolarization, evaluated as an additional approximately 13 ns component. This
feature we attribute tentatively to a greater rotational freedom of the anionic
chromophore. With OPE, the initial anisotropy was close to the theoretical limit
of 0.4; with TPE it was higher, approaching the TPE theoretical limit of 0.57 for
the colinear case. The measured power dependence of the fluorescence signals
provided direct evidence for TPE. The general independence of fluorescence decay
times, rotation correlation times, and steady-state emission spectra on the
excitation mode indicates that the fluorescence originated from the same distinct
excited singlet states (A*, I*, B*). However, we observed a relative enhancement
of blue fluorescence peaked at approximately 440 nm for TPE compared to OPE,
indicating different relative excitation efficiencies. We infer that the two
lifetimes of RSGFP represent the deactivation of two substates of the
deprotonated intermediate (I*), distinguished by their origin (i.e., from A* or
B*) and by nonradiative decay rates reflecting different internal environments of
the excited-state chromophore.
PMID- 10692344
TI - High-resolution imaging of antibodies by tapping-mode atomic force microscopy:
attractive and repulsive tip-sample interaction regimes.
AB - A force microscope operated with an amplitude modulation feedback (usually known
as tapping-mode atomic force microscope) has two tip-sample interaction regimes,
attractive and repulsive. We have studied the performance of those regimes to
imaging single antibody molecules. The attractive interaction regime allows
determination of the basic morphologies of the antibodies on the support. More
importantly, this regime is able to resolve the characteristic Y-shaped domain
structure of antibodies and the hinge region between domains. Imaging in the
repulsive interaction regime is associated with the irreversible deformation of
the molecules. This causes a significant loss in resolution and contrast. Two
major physical differences distinguish the repulsive interaction regime from the
attractive interaction regime: the existence of tip-sample contact and the
strength of the forces involved.
PMID- 10692345
TI - Size-distribution analysis of macromolecules by sedimentation velocity
ultracentrifugation and lamm equation modeling.
AB - A new method for the size-distribution analysis of polymers by sedimentation
velocity analytical ultracentrifugation is described. It exploits the ability of
Lamm equation modeling to discriminate between the spreading of the sedimentation
boundary arising from sample heterogeneity and from diffusion. Finite element
solutions of the Lamm equation for a large number of discrete noninteracting
species are combined with maximum entropy regularization to represent a
continuous size-distribution. As in the program CONTIN, the parameter governing
the regularization constraint is adjusted by variance analysis to a predefined
confidence level. Estimates of the partial specific volume and the frictional
ratio of the macromolecules are used to calculate the diffusion coefficients,
resulting in relatively high-resolution sedimentation coefficient distributions
c(s) or molar mass distributions c(M). It can be applied to interference optical
data that exhibit systematic noise components, and it does not require solution
or solvent plateaus to be established. More details on the size-distribution can
be obtained than from van Holde-Weischet analysis. The sensitivity to the values
of the regularization parameter and to the shape parameters is explored with the
help of simulated sedimentation data of discrete and continuous model size
distributions, and by applications to experimental data of continuous and
discrete protein mixtures.
PMID- 10692346
TI - Factors governing the assembly of cationic phospholipid-DNA complexes.
AB - The interaction of DNA with a novel cationic phospholipid transfection reagent,
1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EDOPC), was investigated by
monitoring thermal effects, particle size, vesicle rupture, and lipid mixing. By
isothermal titration calorimetry, the heat of interaction between large
unilamellar EDOPC vesicles and plasmid DNA was endothermic at both physiological
and low ionic strength, although the heat absorbed was slightly larger at the
higher ionic strength. The energetic driving force for DNA-EDOPC association is
thus an increase in entropy, presumably due to release of counterions and water.
The estimated minimum entropy gain per released counterion was 1.4 cal/mole-
degrees K (about 0.7 kT), consistent with previous theoretical predictions. All
experimental approaches revealed significant differences in the DNA-lipid
particle, depending upon whether complexes were formed by the addition of DNA to
lipid or vice versa. When EDOPC vesicles were titrated with DNA at physiological
ionic strength, particle size increased, vesicles ruptured, and membrane lipids
became mixed as the amount of DNA was added up to a 1.6:1 (+:-) charge ratio.
This charge ratio also corresponded to the calorimetric end point. In contrast,
when lipid was added to DNA, vesicles remained separate and intact until a charge
ratio of 1:1 (+:-) was exceeded. Under such conditions, the calorimetric end
point was 3:1 (+:-). Thus it is clear that fundamental differences in DNA
cationic lipid complexes exist, depending upon their mode of formation. A model
is proposed to explain the major differences between these two situations.
Significant effects of ionic strength were observed; these are rationalized in
terms of the model. The implications of the analysis are that considerable
control can be exerted over the structure of the complex by exploiting vectorial
preparation methods and manipulating ionic strength.
PMID- 10692347
TI - Detergent-induced conformational changes of Humicola lanuginosa lipase studied by
fluorescence spectroscopy.
AB - Detergent (pentaoxyethylene octyl ether, C(8)E(5))-induced conformational changes
of Humicola lanuginosa lipase (HLL) were investigated by stationary and time
resolved fluorescence intensity and anisotropy measurements. Activation of HLL is
characterized by opening of a surface loop (the "lid") residing directly over the
enzyme active site. The interaction of HLL with C(8)E(5) increases fluorescence
intensities, prolongs fluorescence lifetimes, and decreases the values of steady
state anisotropy, residual anisotropy, and the short rotational correlation time.
Based on these data, we propose the following model. Already below critical
micellar concentration (CMC) the detergent can intercalate into the active site
accommodating cleft, while the lid remains closed. Occupation of the cleft by
C(8)E(5) also blocks the entry of the monomeric substrate, and inhibition of
catalytic activity at [C(8)E(5)] less than or equal to CMC is evident. At a
threshold concentration close to CMC the cooperativity of the hydrophobicity
driven binding of C(8)E(5) to the lipase increases because of an increase in the
number of C(8)E(5) molecules present in the premicellar nucleates on the
hydrophobic surface of HLL. These aggregates contacting the lipase should have
long enough residence times to allow the lid to open completely and expose the
hydrophobic cleft. Concomitantly, the cleft becomes filled with C(8)E(5) and the
"open" conformation of HLL becomes stable.
PMID- 10692348
TI - Growing an actin gel on spherical surfaces.
AB - Inspired by the motility of the bacteria Listeria monocytogenes, we have
experimentally studied the growth of an actin gel around spherical beads grafted
with ActA, a protein known to be the promoter of bacteria movement. On ActA
grafted beads F-actin is formed in a spherical manner, whereas on the bacteria a
"comet-like" tail of F-actin is produced. We show experimentally that the
stationary thickness of the gel depends on the radius of the beads. Moreover, the
actin gel is not formed if the ActA surface density is too low. To interpret our
results, we propose a theoretical model to explain how the mechanical stress (due
to spherical geometry) limits the growth of the actin gel. Our model also takes
into account treadmilling of actin. We deduce from our work that the force
exerted by the actin gel on the bacteria is of the order of 10 pN. Finally, we
estimate from our theoretical model possible conditions for developing actin
comet tails.
PMID- 10692349
TI - Signaling components in bacterial locomotion and sensory reception.
PMID- 10692350
TI - Three new NifA-regulated genes in the Bradyrhizobium japonicum symbiotic gene
region discovered by competitive DNA-RNA hybridization.
AB - The so-called symbiotic region of the Bradyrhizobium japonicum chromosome (C.
Kundig, H. Hennecke, and M. Gottfert, J. Bacteriol. 175:613-622, 1993) was
screened for the presence of genes controlled by the nitrogen fixation regulatory
protein NifA. Southern blots of restriction enzyme-digested cosmids that
represent an ordered, overlapping library of the symbiotic region were
competitively hybridized with in vitro-labeled RNA from anaerobically grown wild
type cells and an excess of RNA isolated either from anaerobically grown nifA and
rpoN mutant cells or from aerobically grown wild-type cells. In addition to the
previously characterized nif and fix gene clusters, we identified three new NifA
regulated genes that were named nrgA, nrgB, and nrgC (nrg stands for NifA
regulated gene). The latter two probably form an operon, nrgBC. The proteins
encoded by nrgC and nrgA exhibited amino acid sequence similarity to bacterial
hydroxylases and N-acetyltransferases, respectively. The product of nrgB showed
no significant similarity to any protein with a database entry. Primer extension
experiments and expression studies with translational lacZ fusions revealed the
presence of a functional -24/-12-type promoter upstream of nrgA and nrgBC and
proved the NifA- and RpoN (sigma(54))-dependent transcription of the respective
genes. Null mutations introduced into nrgA and nrgBC resulted in mutant strains
that exhibited wild-type-like symbiotic properties, including nitrogen fixation,
when tested on soybean, cowpea, or mung bean host plants. Thus, the discovery of
nrgA and nrgBC further emphasizes the previously suggested role of NifA as an
activator of anaerobically induced genes other than the classical nitrogen
fixation genes.
PMID- 10692351
TI - Functional analysis of PvdS, an iron starvation sigma factor of Pseudomonas
aeruginosa.
AB - In Pseudomonas aeruginosa, iron modulates gene expression through a cascade of
negative and positive regulatory proteins. The master regulator Fur is involved
in iron-dependent repression of several genes. One of these genes, pvdS, was
predicted to encode a putative sigma factor responsible for the transcription of
a subset of genes of the Fur regulon. PvdS appears to belong to a structurally
and functionally distinct subgroup of the extracytoplasmic function family of
alternative sigma factors. Members of this subgroup, also including PbrA from
Pseudomonas fluorescens, PfrI and PupI from Pseudomonas putida, and FecI from
Escherichia coli, are controlled by the Fur repressor, and they activate
transcription of genes for the biosynthesis or the uptake of siderophores.
Evidence is provided that the PvdS protein of P. aeruginosa is endowed with
biochemical properties of eubacterial sigma factors, as it spontaneously forms
1:1 complexes with the core fraction of RNA polymerase (RNAP, alpha(2)betabeta'
subunits), thereby promoting in vitro binding of the PvdS-RNAP holoenzyme to the
promoter region of the pvdA gene. These functional features of PvdS are
consistent with the presence of structural domains predicted to be involved in
core RNAP binding, promoter recognition, and open complex formation. The activity
of pyoverdin biosynthetic (pvd) promoters was significantly lower in E. coli
overexpressing the multicopy pvdS gene than in wild-type P. aeruginosa PAO1
carrying the single gene copy, and pvd::lacZ transcriptional fusions were silent
in both pfrI (the pvdS homologue) and pfrA (a positive regulator of pseudobactin
biosynthetic genes) mutants of P. putida WCS358, while they are expressed at PAO1
levels in wild-type WCS358. Moreover, the PvdS-RNAP holoenzyme purified from E.
coli lacked the ability to generate in vitro transcripts from the pvdA promoter.
These observations suggest that at least one additional positive regulator could
be required for full activity of the PvdS-dependent transcription complex both in
vivo and in vitro. This is consistent with the presence of a putative activator
binding site (the iron starvation box) at variable distance from the
transcription initiation sites of promoters controlled by the iron starvation
sigma factors PvdS, PfrI, and PbrA of fluorescent pseudomonads.
PMID- 10692352
TI - The TetA(K) tetracycline/H(+) antiporter from Staphylococcus aureus: mutagenesis
and functional analysis of motif C.
AB - Conserved motif C, identified within members of the major facilitator superfamily
(MFS) of transport proteins that mediate drug export, was examined in the
tetracycline resistance efflux protein TetA(K) from Staphylococcus aureus; motif
C is contained within transmembrane segment 5. Using site-directed mutagenesis,
the importance of the conserved glycine (G151, G155, G159, and G160) and proline
(P156) residues within this motif was investigated. Over 40 individual amino acid
replacements were introduced; however, only alanine and serine substitutions for
glycine at G151, G155, and G160 were found to retain significant levels of
tetracycline resistance and transport activity in cells expressing mutant
proteins. Notably, P156 and G159 appear to be crucial, as amino acid replacements
at these positions either significantly reduced or abolished tetracycline/H(+)
activity. The highly conserved nature of motif C and its distribution throughout
drug exporters imply that the residues of motif C play a similar role in all MFS
proteins that function as antiporters.
PMID- 10692353
TI - A novel spore peptidoglycan hydrolase of Bacillus cereus: biochemical
characterization and nucleotide sequence of the corresponding gene, sleL.
AB - The exudate of germinated spores of B. cereus IFO 13597 in 0.15 M KCl-50 mM
potassium phosphate (pH 7.0) contained a spore-lytic enzyme which has substrate
specificity for fragmented spore cortex from wild-type organisms (cortical
fragment-lytic enzyme [CFLE]), in addition to a previously characterized
germination-specific hydrolase which acts on intact spore cortex (spore cortex
lytic enzyme [SCLE]) (R. Moriyama, S. Kudoh, S. Miyata, S. Nonobe, A. Hattori,
and S. Makino, J. Bacteriol. 178:5330-5332, 1996). CFLE was not capable of
degrading isolated cortical fragments from spores of Bacillus subtilis ADD1,
which lacks muramic acid delta-lactam. This suggests that CFLE cooperates with
SCLE in cortex hydrolysis during germination. CFLE was purified in an active form
and identified as a 48-kDa protein which functions as an N-acetylglucosaminidase.
Immunochemical studies suggested that the mature enzyme is localized on a rather
peripheral region of the dormant spore, probably the exterior of the cortex
layer. A gene encoding the enzyme, sleL, was cloned in Escherichia coli, and the
nucleotide sequence was determined. The gene encodes a protein of 430 amino acids
with a deduced molecular weight of 48,136. The N-terminal region contains a
repeated motif common to several peptidoglycan binding proteins. Inspection of
the data banks showed no similarity of CFLE with N-acetylglucosaminidases found
so far, suggesting that CFLE is a novel type of N-acetylglucosaminidase. The B.
subtilis genome sequence contains genes, yaaH and ydhD, which encode putative
proteins showing similarity to SleL.
PMID- 10692354
TI - A gene cluster involved in metal homeostasis in the cyanobacterium Synechocystis
sp. strain PCC 6803.
AB - A gene cluster composed of nine open reading frames (ORFs) involved in Ni(2+),
Co(2+), and Zn(2+) sensing and tolerance in the cyanobacterium Synechocystis sp.
strain PCC 6803 has been identified. The cluster includes an Ni(2+) response
operon and a Co(2+) response system, as well as a Zn(2+) response system
previously described. Expression of the Ni(2+) response operon (nrs) was induced
in the presence of Ni(2+) and Co(2+). Reduced Ni(2+) tolerance was observed
following disruption of two ORFs of the operon (nrsA and nrsD). We also show that
the nrsD gene encodes a putative Ni(2+) permease whose carboxy-terminal region is
a metal binding domain. The Co(2+) response system is composed of two divergently
transcribed genes, corR and corT, mutants of which showed decreased Co(2+)
tolerance. Additionally, corR mutants showed an absence of Co(2+)-dependent
induction of corT, indicating that CorR is a transcriptional activator of corT.
To our knowledge, CorR is the first Co(2+)-sensing transcription factor
described. Our data suggest that this region of the Synechocystis sp. strain PCC
6803 genome is involved in sensing and homeostasis of Ni(2+), Co(2+), and Zn(2+).
PMID- 10692355
TI - Evolution of drug resistance in experimental populations of Candida albicans.
AB - Adaptation to inhibitory concentrations of the antifungal agent fluconazole was
monitored in replicated experimental populations founded from a single, drug
sensitive cell of the yeast Candida albicans and reared over 330 generations. The
concentration of fluconazole was maintained at twice the MIC in six populations;
no fluconazole was added to another six populations. All six replicate
populations grown with fluconazole adapted to the presence of drug as indicated
by an increase in MIC; none of the six populations grown without fluconazole
showed any change in MIC. In all populations evolved with drug, increased
fluconazole resistance was accompanied by increased resistance to ketoconazole
and itraconazole; these populations contained ergosterol in their cell membranes
and were amphotericin sensitive. The increase in fluconazole MIC in the six
populations evolved with drug followed different trajectories, and these
populations achieved different levels of resistance, with distinct overexpression
patterns of four genes involved in azole resistance: the ATP-binding cassette
transporter genes, CDR1 and CDR2; the gene encoding the target enzyme of the
azoles in the ergosterol biosynthetic pathway, ERG11; and the major facilitator
gene, MDR1. Selective sweeps in these populations were accompanied by additional
genomic changes with no known relationship to drug resistance: loss of
heterozygosity in two of the five marker genes assayed and alterations in DNA
fingerprints and electrophoretic karyotypes. These results show that chance, in
the form of mutations that confer an adaptive advantage, is a determinant in the
evolution of azole drug resistance in experimental populations of C. albicans.
PMID- 10692356
TI - Molecular basis for the temperature sensitivity of Escherichia coli pth(Ts).
AB - The gene pth, encoding peptidyl-tRNA hydrolase (Pth), is essential for protein
synthesis and viability of Escherichia coli. Two pth mutants have been studied in
depth: a pth(Ts) mutant isolated as temperature sensitive and a pth(rap) mutant
selected as nonpermissive for bacteriophage lambda vegetative growth. Here we
show that each mutant protein is defective in a different way. The Pth(Ts)
protein was very unstable in vivo, both at 43 degrees C and at permissive
temperatures, but its specific activity was comparable to that of the wild-type
enzyme, Pth(wt). Conversely, the mutant Pth(rap) protein had the same stability
as Pth(wt), but its specific activity was low. The thermosensitivity of the
pth(Ts) mutant, presumably, ensues after Pth(Ts) protein levels are reduced at 43
degrees C. Conditions that increased the cellular Pth(Ts) concentration, a rise
in gene copy number or diminished protein degradation, allowed cell growth at a
nonpermissive temperature. Antibiotic-mediated inhibition of mRNA and protein
synthesis, but not of peptidyl-tRNA drop-off, reduced pth(Ts) cell viability even
at a permissive temperature. Based on these results, we suggest that Pth(Ts)
protein, being unstable in vivo, supports cell viability only if its
concentration is maintained above a threshold that allows general protein
synthesis.
PMID- 10692357
TI - The RofA binding site in Streptococcus pyogenes is utilized in multiple
transcriptional pathways.
AB - Understanding the regulation of adhesins defines a pathogenic bacterium's
interaction with the local environment within the host. In certain strains of
Streptococcus pyogenes, transcription of prtF, the gene which encodes the
fibronectin-binding adhesin protein F, is activated by RofA under anaerobic
conditions. RofA binds specifically to DNA in its target promoters and
autoregulates its own expression. In this study, we have used DNase I protection
assays to further investigate the interaction of RofA with its target promoters.
In the region between rofA and the gene which encodes protein F (prtF), RofA
binds to two distinct sites: a smaller site (17 bp) adjacent to the rofA
promoter, and a larger site (40 bp) adjacent to the prtF promoter. Analysis of
fusions to a novel reporter gene whose product consists of the fusion of the N
terminal secretion domain of protein F with the C-terminal enzymatic domain of
the enterococcal alkaline phosphatase (PhoZ) revealed that the small RofA binding
site had no direct role in control of prtF transcription but contributed to
regulation of rofA. Comparison in several strains representing different patterns
of prtF expression indicated that the larger site was required for activation of
rofA and of prtF in all strains by both RofA-dependent and -independent pathways.
Thus, it would appear that a common recognition sequence provides separate
entries to a final common pathway in S. pyogenes virulence gene expression. The
identification of multiple RofA-like proteins and promoters with RofA binding
sites implies the existence of a widespread interacting regulatory network.
PMID- 10692358
TI - TraG from RP4 and TraG and VirD4 from Ti plasmids confer relaxosome specificity
to the conjugal transfer system of pTiC58.
AB - Plasmid conjugation systems are composed of two components, the DNA transfer and
replication system, or Dtr, and the mating pair formation system, or Mpf. During
conjugal transfer an essential factor, called the coupling protein, is thought to
interface the Dtr, in the form of the relaxosome, with the Mpf, in the form of
the mating bridge. These proteins, such as TraG from the IncP1 plasmid RP4
(TraG(RP4)) and TraG and VirD4 from the conjugal transfer and T-DNA transfer
systems of Ti plasmids, are believed to dictate specificity of the interactions
that can occur between different Dtr and Mpf components. The Ti plasmids of
Agrobacterium tumefaciens do not mobilize vectors containing the oriT of RP4, but
these IncP1 plasmid derivatives lack the trans-acting Dtr functions and
TraG(RP4). A. tumefaciens donors transferred a chimeric plasmid that contains the
oriT and Dtr genes of RP4 and the Mpf genes of pTiC58, indicating that the Ti
plasmid mating bridge can interact with the RP4 relaxosome. However, the Ti
plasmid did not mobilize transfer from an IncQ relaxosome. The Ti plasmid did
mobilize such plasmids if TraG(RP4) was expressed in the donors. Mutations in
traG(RP4) with defined effects on the RP4 transfer system exhibited similar
phenotypes for Ti plasmid-mediated mobilization of the IncQ vector. When provided
with VirD4, the tra system of pTiC58 mobilized plasmids from the IncQ relaxosome.
However, neither TraG(RP4) nor VirD4 restored transfer to a traG mutant of the Ti
plasmid. VirD4 also failed to complement a traG(RP4) mutant for transfer from the
RP4 relaxosome or for RP4-mediated mobilization from the IncQ relaxosome.
TraG(RP4)-mediated mobilization of the IncQ plasmid by pTiC58 did not inhibit Ti
plasmid transfer, suggesting that the relaxosomes of the two plasmids do not
compete for the same mating bridge. We conclude that TraG(RP4) and VirD4 couples
the IncQ but not the Ti plasmid relaxosome to the Ti plasmid mating bridge.
However, VirD4 cannot couple the IncP1 or the IncQ relaxosome to the RP4 mating
bridge. These results support a model in which the coupling proteins specify the
interactions between Dtr and Mpf components of mating systems.
PMID- 10692359
TI - Association of the cytoplasmic membrane protein XpsN with the outer membrane
protein XpsD in the type II protein secretion apparatus of Xanthomonas campestris
pv. campestris.
AB - An xps gene cluster composed of 11 open reading frames is required for the type
II protein secretion in Xanthomonas campestris pv. campestris. Immediately
upstream of the xpsD gene, which encodes an outer membrane protein that serves as
the secretion channel by forming multimers, there exists an open reading frame
(previously designated ORF2) that could encode a protein of 261 amino acid
residues. Its N-terminal hydrophobic region is a likely membrane-anchoring
sequence. Antibody raised against this protein could detect in the wild-type
strain of X. campestris pv. campestris a protein band with an apparent molecular
mass of 36 kDa by Western blotting. Its aberrant slow migration in sodium dodecyl
sulfate-polyacrylamide gels might be due to its high proline content. We
designated this protein XpsN. By constructing a mutant strain with an in-frame
deletion of the chromosomal xpsN gene, we demonstrated that it is required for
the secretion of extracellular enzyme by X. campestris pv. campestris.
Subcellular fractionation studies indicated that the XpsN protein was tightly
associated with the membrane. Sucrose gradient sedimentation followed by
immunoblot analysis revealed that it primarily appeared in the cytoplasmic
membrane fractions. Immune precipitation experiments indicated that the XpsN
protein was coprecipitated with the XpsD protein. In addition, the XpsN protein
was co-eluted with the (His)(6)-tagged XpsD protein from the metal affinity
chromatography column. All observations suggested that the XpsN protein forms a
stable complex with the XpsD protein. In addition, immune precipitation analysis
of the XpsN protein with various truncated XpsD proteins revealed that the C
terminal region of the XpsD protein between residues 650 and 759 was likely to be
involved in complex formation between the two.
PMID- 10692360
TI - ssrA (tmRNA) plays a role in Salmonella enterica serovar Typhimurium
pathogenesis.
AB - Escherichia coli ssrA encodes a small stable RNA molecule, tmRNA, that has many
diverse functions, including tagging abnormal proteins for degradation,
supporting phage growth, and modulating the activity of DNA binding proteins.
Here we show that ssrA plays a role in Salmonella enterica serovar Typhimurium
pathogenesis and in the expression of several genes known to be induced during
infection. Moreover, the phage-like attachment site, attL, encoded within ssrA,
serves as the site of integration of a region of Salmonella-specific sequence;
adjacent to the 5' end of ssrA is another region of Salmonella-specific sequence
with extensive homology to predicted proteins encoded within the unlinked
Salmonella pathogenicity island SPI4. S. enterica serovar Typhimurium ssrA
mutants fail to support the growth of phage P22 and are delayed in their ability
to form viable phage particles following induction of a phage P22 lysogen. These
data indicate that ssrA plays a role in the pathogenesis of Salmonella, serves as
an attachment site for Salmonella-specific sequences, and is required for the
growth of phage P22.
PMID- 10692361
TI - Components of the RP4 conjugative transfer apparatus form an envelope structure
bridging inner and outer membranes of donor cells: implications for related
macromolecule transport systems.
AB - During bacterial conjugation, the single-stranded DNA molecule is transferred
through the cell envelopes of the donor and the recipient cell. A membrane
spanning transfer apparatus encoded by conjugative plasmids has been proposed to
facilitate protein and DNA transport. For the IncPalpha plasmid RP4, a thorough
sequence analysis of the gene products of the transfer regions Tra1 and Tra2
revealed typical features of mainly inner membrane proteins. We localized
essential RP4 transfer functions to Escherichia coli cell fractions by
immunological detection with specific polyclonal antisera. Each of the gene
products of the RP4 mating pair formation (Mpf) system, specified by the Tra2
core region and by traF of the Tra1 region, was found in the outer membrane
fraction with one exception, the TrbB protein, which behaved like a soluble
protein. The membrane preparation from Mpf-containing cells had an additional
membrane fraction whose density was intermediate between those of the cytoplasmic
and outer membranes, suggesting the presence of attachment zones between the two
E. coli membranes. The Tra1 region is known to encode the components of the RP4
relaxosome. Several gene products of this transfer region, including the relaxase
TraI, were detected in the soluble fraction, but also in the inner membrane
fraction. This indicates that the nucleoprotein complex is associated with and/or
assembled facing the cytoplasmic site of the E. coli cell envelope. The Tra1
protein TraG was predominantly localized to the cytoplasmic membrane, supporting
its potential role as an interface between the RP4 Mpf system and the relaxosome.
PMID- 10692362
TI - Identification of the active site of HetR protease and its requirement for
heterocyst differentiation in the cyanobacterium Anabaena sp. strain PCC 7120.
AB - HetR is a serine-type protease required for heterocyst differentiation in
heterocystous cyanobacteria under conditions of nitrogen deprivation. We have
identified the active Ser residue of HetR from Anabaena sp. strain PCC 7120 by
site-specific mutagenesis. By changing the S152 residue to an Ala residue, the
mutant protein cannot be labeled by Dansyl fluoride, a specific serine-type
protein inhibitor. The mutant protein showed no autodegradation in vitro. The
mutant hetR gene was introduced into Anabaena strain 884a, a hetR mutant. The
resultant strain, Anabaena strain S152A, could not form heterocysts under
conditions of nitrogen deprivation even though the up-regulation of the mutant
hetR gene was induced upon removal of combined nitrogen. The Anabaena strain 216,
which carries a mutant hetR gene encoding S179N HetR and could not form
heterocysts, also produced HetR protein upon induction. Sequence comparison shows
that Ser152 is conserved in all cyanobacterial HetR. Immunoblotting was used to
study HetR induction in both the wild-type and mutant strains. The amount of
mutant HetR in strain S152A and in strain 216 increased continuously for 24 h
after nitrogen step-down, while the amount of HetR in wild-type cells reached a
maximum level within 6 h after nitrogen step-down. Our results show the Ser152 is
the active site of HetR. The protease activity is required for heterocyst
differentiation and might be needed for repression of HetR overproduction under
conditions of nitrogen deprivation.
PMID- 10692363
TI - EFG1 null mutants of Candida albicans switch but cannot express the complete
phenotype of white-phase budding cells.
AB - The Candida albicans gene EFG1 encodes a putative trans-acting factor. In strain
WO-1, which undergoes the white-opaque transition, EFG1 is transcribed as a 3.2
kb mRNA in white-phase cells and a less-abundant 2.2-kb mRNA in opaque-phase
cells. cDNA sequencing and 5' rapid amplification of cDNA ends analysis
demonstrate that the major difference in molecular mass of the two transcripts is
due to different transcription start sites. EFG1 null mutants form opaque-phase
colonies and express the opaque-phase cell phenotype at 25 degrees C. When
shifted from 25 to 42 degrees C, mutant opaque-phase cells undergo phenotypic
commitment to the white phase, which includes deactivation of the opaque-phase
specific gene OP4 and activation of the white-phase-specific gene WH11, as do
wild-type opaque-phase cells. After the commitment event, EFG1 null mutant cells
form daughter cells which have the smooth (pimpleless) surface of white-phase
cells but the elongate morphology of opaque-phase cells. Taken together, these
results demonstrate that EFG1 expression is not essential for the switch event
per se, but is essential for a subset of phenotypic characteristics necessary for
the full expression of the phenotype of white-phase cells. These results
demonstrate that EFG1 is not the site of the switch event, but is, rather,
downstream of the switch event.
PMID- 10692364
TI - Expression of ykdA, encoding a Bacillus subtilis homologue of HtrA, is heat shock
inducible and negatively autoregulated.
AB - There are three members of the HtrA family of serine proteases, YkdA, YvtA, and
YyxA, encoded in the chromosome of Bacillus subtilis. In this study, we report on
the promoter structure and regulation of ykdA expression. The ykdA gene is heat
inducible, exhibiting a biphasic pattern of expression during a 60-min interval
after heat shock. Increased expression after heat shock occurs at the
transcriptional level. The heat-shock-inducible promoter has a single mismatch
with a SigA-type -10 motif, but does not exhibit similarity to a SigA -35 region.
There are six octamer repeats with a consensus TTTTCACA positioned at, and
upstream of, the normal position of a -35 region. While repeats V and VI appear
dispensable, repeat IV is essential for normal thermoinducible expression. This
promoter structure is also found in the control region of yvtA, encoding a second
member of this family of proteases. Expression of ykdA is negatively
autoregulated both during the growth cycle and during heat shock. Our evidence
suggests that YkdA protease activity is not required for this form of regulation.
Null mutants of ykdA display increased tolerance to heat and are 80-fold more
resistant to 10 mM hydrogen peroxide than wild-type cells. However, ykdA
expression is not induced by hydrogen peroxide. These results indicate that the
regulon to which YkdA belongs is linked to the oxidative stress response in B.
subtilis.
PMID- 10692365
TI - Specificity mutants of the binding protein of the oligopeptide transport system
of Lactococcus lactis.
AB - The kinetic properties of wild-type and mutant oligopeptide binding proteins of
Lactococcus lactis were determined. To observe the properties of the mutant
proteins in vivo, the oppA gene was deleted from the chromosome of L. lactis to
produce a strain that was totally defective in oligopeptide transport. Amplified
expression of the oppA gene resulted in an 8- to 12-fold increase in OppA protein
relative to the wild-type level. The amplified expression was paralleled by
increased bradykinin binding activity, but had relatively little effect on the
overall transport of bradykinin via Opp. Several site-directed mutants were
constructed on the basis of a comparison of the primary sequences of OppA from
Salmonella enterica serovar Typhimurium and L. lactis, taking into account the
known structure of the serovar Typhimurium protein. Putative peptide binding-site
residues were mutated. All the mutant OppA proteins exhibited a decreased binding
affinity for the high-affinity peptide bradykinin. Except for OppA(D471R), the
mutant OppA proteins displayed highly defective bradykinin uptake, whereas the
transport of the low-affinity substrate KYGK was barely affected. Cells
expressing OppA(D471R) had a similar K(m) for transport, whereas the V(max) was
increased more than twofold as compared to the wild-type protein. The data are
discussed in the light of a kinetic model and imply that the rate of transport is
determined to a large extent by the donation of the peptide from the OppA protein
to the translocator complex.
PMID- 10692366
TI - Evolution of arginine biosynthesis in the bacterial domain: novel gene-enzyme
relationships from psychrophilic Moritella strains (Vibrionaceae) and
evolutionary significance of N-alpha-acetyl ornithinase.
AB - In the arginine biosynthetic pathway of the vast majority of prokaryotes, the
formation of ornithine is catalyzed by an enzyme transferring the acetyl group of
N-alpha-acetylornithine to glutamate (ornithine acetyltransferase [OATase]) (argJ
encoded). Only two exceptions had been reported-the Enterobacteriaceae and
Myxococcus xanthus (members of the gamma and delta groups of the class
Proteobacteria, respectively)-in which ornithine is produced from N-alpha
acetylornithine by a deacylase, acetylornithinase (AOase) (argE encoded). We have
investigated the gene-enzyme relationship in the arginine regulons of two
psychrophilic Moritella strains belonging to the Vibrionaceae, a family
phylogenetically related to the Enterobacteriaceae. Most of the arg genes were
found to be clustered in one continuous sequence divergently transcribed in two
wings, argE and argCBFGH(A) ["H(A)" indicates that the argininosuccinase gene
consists of a part homologous to known argH sequences and of a 3' extension able
to complement an Escherichia coli mutant deficient in the argA gene, encoding N
alpha-acetylglutamate synthetase, the first enzyme committed to the pathway].
Phylogenetic evidence suggests that this new clustering pattern arose in an
ancestor common to Vibrionaceae and Enterobacteriaceae, where OATase was lost and
replaced by a deacylase. The AOase and ornithine carbamoyltransferase of these
psychrophilic strains both display distinctly cold-adapted activity profiles,
providing the first cold-active examples of such enzymes.
PMID- 10692367
TI - Functionality of purified sigma(N) (sigma(54)) and a NifA-like protein from the
hyperthermophile Aquifex aeolicus.
AB - The genome sequence of the extremely thermophilic bacterium Aquifex aeolicus
encodes alternative sigma factor sigma(N) (sigma(54), RpoN) and five potential
sigma(N)-dependent transcriptional activators. Although A. aeolicus possesses no
recognizable nitrogenase genes, two of the activators have a high degree of
sequence similarity to NifA proteins from nitrogen-fixing proteobacteria. We
identified five putative sigma(N)-dependent promoters upstream of operons
implicated in functions including sulfur respiration, nitrogen assimilation,
nitrate reductase, and nitrite reductase activity. We cloned, overexpressed (in
Escherichia coli), and purified A. aeolicus sigma(N) and the NifA homologue,
AQ_218. Purified A. aeolicus sigma(N) bound to E. coli core RNA polymerase and
bound specifically to a DNA fragment containing E. coli promoter glnHp2 and to
several A. aeolicus DNA fragments containing putative sigma(N)-dependent
promoters. When combined with E. coli core RNA polymerase, A. aeolicus sigma(N)
supported A. aeolicus NifA-dependent transcription from the glnHp2 promoter. The
E. coli activator PspFDeltaHTH did not stimulate transcription. The NifA
homologue, AQ_218, bound specifically to a DNA sequence centered about 100 bp
upstream of the A. aeolicus glnBA operon and so is likely to be involved in the
regulation of nitrogen assimilation in this organism. These results argue that
the sigma(N) enhancer-dependent transcription system operates in at least one
extreme environment, and that the activator and sigma(N) have coevolved.
PMID- 10692368
TI - Transcriptional and mutational analysis of the uptake hydrogenase of the
filamentous cyanobacterium Anabaena variabilis ATCC 29413.
AB - A 10-kb DNA region of the cyanobacterium Anabaena variabilis ATCC 29413
containing the structural genes of the uptake hydrogenase (hupSL) was cloned and
sequenced. In contrast to the hupL gene of Anabaena sp. strain PCC 7120, which is
interrupted by a 10.5-kb DNA fragment in vegetative cells, there is no programmed
rearrangement within the hupL gene during the heterocyst differentiation of A.
variabilis. The hupSL genes were transcribed as a 2.7-kb operon and were induced
only under nitrogen-fixing conditions, as shown by Northern blot experiments and
reverse transcriptase PCR. Primer extension experiments with a fluorescence
labeled oligonucleotide primer confirmed these results and identified the 5'
start of the mRNA transcript 103 bp upstream of the ATG initiation codon. A
consensus sequence in the promoter that is recognized by the fumarate nitrate
reductase regulator (Fnr) could be detected. The hupSL operon in A. variabilis
was interrupted by an interposon deletion (mutant strain AVM13). Under N(2)
fixing conditions, the mutant strain exhibited significantly increased rates in
H(2) accumulation and produced three times more hydrogen than the wild type.
These results indicate that the uptake hydrogenase is catalytically active in the
wild type and that the enzyme reoxidizes the H(2) developed by the nitrogenase.
The Nif phenotype of the mutant strain showed a slight decrease of acetylene
reduction compared to that of the wild type.
PMID- 10692369
TI - Global regulatory mutations in csrA and rpoS cause severe central carbon stress
in Escherichia coli in the presence of acetate.
AB - The csrA gene encodes a small RNA-binding protein, which acts as a global
regulator in Escherichia coli and other bacteria (T. Romeo, Mol. Microbiol.
29:1321-1330, 1998). Its key regulatory role in central carbon metabolism, both
as an activator of glycolysis and as a potent repressor of glycogen biosynthesis
and gluconeogenesis, prompted us to examine the involvement of csrA in acetate
metabolism and the tricarboxylic acid (TCA) cycle. We found that growth of csrA
rpoS mutant strains was very poor on acetate as a sole carbon source.
Surprisingly, growth also was inhibited specifically by the addition of modest
amounts of acetate to rich media (e.g., tryptone broth). Cultures grown in the
presence of >/=25 mM acetate consisted substantially of glycogen biosynthesis
(glg) mutants, which were no longer inhibited by acetate. Several classes of glg
mutations were mapped to known and novel loci. Several hypotheses were examined
to provide further insight into the effects of acetate on growth and metabolism
in these strains. We determined that csrA positively regulates acs (acetyl
coenzyme A synthetase; Acs) expression and isocitrate lyase activity without
affecting key TCA cycle enzymes or phosphotransacetylase. TCA cycle intermediates
or pyruvate, but not glucose, galactose, or glycerol, restored growth and
prevented the glg mutations in the presence of acetate. Furthermore, amino acid
uptake was inhibited by acetate specifically in the csrA rpoS strain. We conclude
that central carbon flux imbalance, inhibition of amino acid uptake, and a
deficiency in acetate metabolism apparently are combined to cause metabolic
stress by depleting the TCA cycle.
PMID- 10692370
TI - Substrate specificity of naphthalene dioxygenase: effect of specific amino acids
at the active site of the enzyme.
AB - The three-component naphthalene dioxygenase (NDO) enzyme system carries out the
first step in the aerobic degradation of naphthalene by Pseudomonas sp. strain
NCIB 9816-4. The three-dimensional structure of NDO revealed that several of the
amino acids at the active site of the oxygenase are hydrophobic, which is
consistent with the enzyme's preference for aromatic hydrocarbon substrates.
Although NDO catalyzes cis-dihydroxylation of a wide range of substrates, it is
highly regio- and enantioselective. Site-directed mutagenesis was used to
determine the contributions of several active-site residues to these aspects of
catalysis. Amino acid substitutions at Asn-201, Phe-202, Val-260, Trp-316, Thr
351, Trp-358, and Met-366 had little or no effect on product formation with
naphthalene or biphenyl as substrates and had slight but significant effects on
product formation from phenanthrene. Amino acid substitutions at Phe-352 resulted
in the formation of cis-naphthalene dihydrodiol with altered stereochemistry [92
to 96% (+)-1R,2S], compared to the enantiomerically pure [>99% (+)-1R,2S] product
formed by the wild-type enzyme. Substitutions at position 352 changed the site of
oxidation of biphenyl and phenanthrene. Substitution of alanine for Asp-362, a
ligand to the active-site iron, resulted in a completely inactive enzyme.
PMID- 10692371
TI - Penicillin-binding protein-related factor A is required for proper chromosome
segregation in Bacillus subtilis.
AB - Previous work has shown that the ponA gene, encoding penicillin-binding protein 1
(PBP1), is in a two-gene operon with prfA (PBP-related factor A) (also called
recU), which encodes a putative 206-residue basic protein (pI = 10.1) with no
significant sequence homology to proteins with known functions. Inactivation of
prfA results in cells that grow slower and vary significantly in length relative
to wild-type cells. We now show that prfA mutant cells have a defect in
chromosome segregation resulting in the production of approximately 0.9 to 3%
anucleate cells in prfA cultures grown at 30 or 37 degrees C in rich medium and
that the lack of PrfA exacerbates the chromosome segregation defect in smc and
spoOJ mutant cells. In addition, overexpression of prfA was found to be toxic for
and cause nucleoid condensation in Escherichia coli.
PMID- 10692372
TI - Analysis of Escherichia coli RecA interactions with LexA, lambda CI, and UmuD by
site-directed mutagenesis of recA.
AB - An early event in the induction of the SOS system of Escherichia coli is RecA
mediated cleavage of the LexA repressor. RecA acts indirectly as a coprotease to
stimulate repressor self-cleavage, presumably by forming a complex with LexA. How
complex formation leads to cleavage is not known. As an approach to this
question, it would be desirable to identify the protein-protein interaction sites
on each protein. It was previously proposed that LexA and other cleavable
substrates, such as phage lambda CI repressor and E. coli UmuD, bind to a cleft
located between two RecA monomers in the crystal structure. To test this model,
and to map the interface between RecA and its substrates, we carried out alanine
scanning mutagenesis of RecA. Twenty double mutations were made, and cells
carrying them were characterized for RecA-dependent repair functions and for
coprotease activity towards LexA, lambda CI, and UmuD. One mutation in the cleft
region had partial defects in cleavage of CI and (as expected from previous data)
of UmuD. Two mutations in the cleft region conferred constitutive cleavage
towards CI but not towards LexA or UmuD. By contrast, no mutations in the cleft
region or elsewhere in RecA were found to specifically impair the cleavage of
LexA. Our data are consistent with binding of CI and UmuD to the cleft between
two RecA monomers but do not provide support for the model in which LexA binds in
this cleft.
PMID- 10692373
TI - Transposon insertions in the Flavobacterium johnsoniae ftsX gene disrupt gliding
motility and cell division.
AB - Flavobacterium johnsoniae is a gram-negative bacterium that exhibits gliding
motility. To determine the mechanism of flavobacterial gliding motility, we
isolated 33 nongliding mutants by Tn4351 mutagenesis. Seventeen of these mutants
exhibited filamentous cell morphology. The region of DNA surrounding the
transposon insertion in the filamentous mutant CJ101-207 was cloned and
sequenced. The transposon was inserted in a gene that was similar to Escherichia
coli ftsX. Two of the remaining 16 filamentous mutants also carried insertions in
ftsX. Introduction of the wild-type F. johnsoniae ftsX gene restored motility and
normal cell morphology to each of the three ftsX mutants. CJ101-207 appears to be
blocked at a late stage of cell division, since the filaments produced cross
walls but cells failed to separate. In E. coli, FtsX is thought to function with
FtsE in translocating proteins involved in potassium transport, and perhaps
proteins involved in cell division, into the cytoplasmic membrane. Mutations in
F. johnsoniae ftsX may prevent translocation of proteins involved in cell
division and proteins involved in gliding motility into the cytoplasmic membrane,
thus resulting in defects in both processes. Alternatively, the loss of gliding
motility may be an indirect result of the defect in cell division. The inability
to complete cell division may alter the cell architecture and disrupt gliding
motility by preventing the synthesis, assembly, or functioning of the motility
apparatus.
PMID- 10692375
TI - Role of cell shape in determination of the division plane in Schizosaccharomyces
pombe: random orientation of septa in spherical cells.
AB - The establishment of growth polarity in Schizosaccharomyces pombe cells is a
combined function of the cytoplasmic cytoskeleton and the shape of the cell wall
inherited from the mother cell. The septum that divides the cylindrical cell into
two siblings is formed midway between the growing poles and perpendicularly to
the axis that connects them. Since the daughter cells also extend at their ends
and form their septa at right angles to the longitudinal axis, their septal
(division) planes lie parallel to those of the mother cell. To gain a better
understanding of how this regularity is ensured, we investigated septation in
spherical cells that do not inherit morphologically predetermined cell ends to
establish poles for growth. We studied four mutants (defining four novel genes),
over 95% of whose cells displayed a completely spherical morphology and a
deficiency in mating and showed a random distribution of cytoplasmic
microtubules, Tea1p, and F-actin, indicating that the cytoplasmic cytoskeleton
was poorly polarized or apolar. Septum positioning was examined by visualizing
septa and division scars by calcofluor staining and by the analysis of electron
microscopic images. Freeze-substitution, freeze-etching, and scanning electron
microscopy were used. We found that the elongated bipolar shape is not essential
for the determination of a division plane that can separate the postmitotic
nuclei. However, it seems to be necessary for the maintenance of the parallel
orientation of septa over the generations. In the spherical cells, the division
scars and septa usually lie at angles to each other on the cell surface. We
hypothesize that the shape of the cell indirectly affects the positioning of the
septum by directing the extension of the spindle.
PMID- 10692374
TI - Biochemical and physical properties of the Methanococcus jannaschii 20S
proteasome and PAN, a homolog of the ATPase (Rpt) subunits of the eucaryal 26S
proteasome.
AB - The 20S proteasome is a self-compartmentalized protease which degrades unfolded
polypeptides and has been purified from eucaryotes, gram-positive actinomycetes,
and archaea. Energy-dependent complexes, such as the 19S cap of the eucaryal 26S
proteasome, are assumed to be responsible for the recognition and/or unfolding of
substrate proteins which are then translocated into the central chamber of the
20S proteasome and hydrolyzed to polypeptide products of 3 to 30 residues. All
archaeal genomes which have been sequenced are predicted to encode proteins with
up to approximately 50% identity to the six ATPase subunits of the 19S cap. In
this study, one of these archaeal homologs which has been named PAN for
proteasome-activating nucleotidase was characterized from the hyperthermophile
Methanococcus jannaschii. In addition, the M. jannaschii 20S proteasome was
purified as a 700-kDa complex by in vitro assembly of the alpha and beta subunits
and has an unusually high rate of peptide and unfolded-polypeptide hydrolysis at
100 degrees C. The 550-kDa PAN complex was required for CTP- or ATP-dependent
degradation of beta-casein by archaeal 20S proteasomes. A 500-kDa complex of
PAN(Delta1-73), which has a deletion of residues 1 to 73 of the deduced protein
and disrupts the predicted N-terminal coiled-coil, also facilitated this energy
dependent proteolysis. However, this deletion increased the types of nucleotides
hydrolyzed to include not only ATP and CTP but also ITP, GTP, TTP, and UTP. The
temperature optimum for nucleotide (ATP) hydrolysis was reduced from 80 degrees C
for the full-length protein to 65 degrees C for PAN(Delta1-73). Both PAN protein
complexes were stable in the absence of ATP and were inhibited by N
ethylmaleimide and p-chloromercuriphenyl-sulfonic acid. Kinetic analysis reveals
that the PAN protein has a relatively high V(max) for ATP and CTP hydrolysis of
3.5 and 5.8 micromol of P(i) per min per mg of protein as well as a relatively
low affinity for CTP and ATP with K(m) values of 307 and 497 microM compared to
other proteins of the AAA family. Based on electron micrographs, PAN and
PAN(Delta1-73) apparently associate with the ends of the 20S proteasome cylinder.
These results suggest that the M. jannaschii as well as related archaeal 20S
proteasomes require a nucleotidase complex such as PAN to mediate the energy
dependent hydrolysis of folded-substrate proteins and that the N-terminal 73
amino acid residues of PAN are not absolutely required for this reaction.
PMID- 10692376
TI - Dual roles of Bradyrhizobium japonicum nickelin protein in nickel storage and GTP
dependent Ni mobilization.
AB - The hydrogenase accessory protein HypB, or nickelin, has two functions in the
N(2)-fixing, H(2)-oxidizing bacterium Bradyrhizobium japonicum. One function of
HypB involves the mobilization of nickel into hydrogenase. HypB also carries out
a nickel storage/sequestering function in B. japonicum, binding nine nickel ions
per monomer. Here we report that the two roles (nickel mobilization and storage)
of HypB can be separated in vitro and in vivo using molecular and biochemical
approaches. The role of HypB in hydrogenase maturation is completely dependent on
its intrinsic GTPase activity; strains which produce a HypB protein that is
severely deficient in GTPase activity but that fully retains nickel-sequestering
ability cannot produce active hydrogenase even upon prolonged nickel
supplementation. A HypB protein that lacks the nickel-binding polyhistidine
region near the N terminus lacks only the nickel storage capacity function; it is
still able to bind a single nickel ion and also retains complete GTPase activity.
PMID- 10692377
TI - Identification of genes in the RosR regulon of Rhizobium etli.
AB - RosR is a determinant of nodulation competitiveness and cell surface
characteristics of Rhizobium etli and has sequence similarity to a family of
transcriptional repressors. To understand how RosR affects these phenotypes, we
mutagenized a rosR mutant derivative of R. etli strain CE3 with a mini-Tn5 that
contains a promoterless gusA gene at one end, which acts as a transcriptional
reporter. Using a mass-mating technique, we introduced rosR into each mutant in
trans and screened for mutants that expressed different levels of beta
glucuronidase activity in the presence and absence of rosR. A screen of 18,000
mutants identified 52 insertions in genes negatively regulated by RosR and 1
insertion in a gene positively regulated by RosR. Nucleotide sequence analysis of
the regions flanking the insertions suggests that RosR regulates genes of diverse
function, including those involved in polysaccharide production and in
carbohydrate metabolism and those in a region containing sequence similarity to
virC1 and virD3 from Agrobacterium tumefaciens. Two of the mutants produced
colonies with altered morphology and were more competitive in nodulation than was
CE3DeltarosR, the rosR parent. One mutant that contained an insertion in a gene
with similarity to exsH of Sinorhizobium meliloti did not nodulate the plant host
Phaseolus vulgaris without rosR. These results indicate that RosR directly or
indirectly influences expression of diverse genes in R. etli, some of which
affect the cell surface and nodulation competitiveness.
PMID- 10692378
TI - Penicillin binding protein 5 affects cell diameter, contour, and morphology of
Escherichia coli.
AB - Although general physiological functions have been ascribed to the high-molecular
weight penicillin binding proteins (PBPs) of Escherichia coli, the low-molecular
weight PBPs have no well-defined biological roles. When we examined the
morphology of a set of E. coli mutants lacking multiple PBPs, we observed that
strains expressing active PBP 5 produced cells of normal shape, while mutants
lacking PBP 5 produced cells with altered diameters, contours, and topological
features. These morphological effects were visible in untreated cells, but the
defects were exacerbated in cells forced to filament by inactivation of PBP 3 or
FtsZ. After filamentation, cellular diameter varied erratically along the length
of individual filaments and many filaments exhibited extensive branching. Also,
in general, the mean diameter of cells lacking PBP 5 was significantly increased
compared to that of cells from isogenic strains expressing active PBP 5.
Expression of cloned PBP 5 reversed the effects observed in DeltadacA mutants.
Although deletion of PBP 5 was required for these phenotypes, the absence of
additional PBPs magnified the effects. The greatest morphological alterations
required that at least three PBPs in addition to PBP 5 be deleted from a single
strain. In the extreme cases in which six or seven PBPs were deleted from a
single mutant, cells and cell filaments expressing PBP 5 retained a normal
morphology but cells and filaments lacking PBP 5 were aberrant. In no case did
mutation of another PBP produce the same drastic morphological effects. We
conclude that among the low-molecular-weight PBPs, PBP 5 plays a principle role
in determining cell diameter, surface uniformity, and overall topology of the
peptidoglycan sacculus.
PMID- 10692379
TI - Membrane topology of the NixA nickel transporter of Helicobacter pylori: two
nickel transport-specific motifs within transmembrane helices II and III.
AB - NixA, the high-affinity cytoplasmic membrane nickel transport protein of
Helicobacter pylori, imports Ni(2+) into the cell for insertion into the active
site of the urease metalloenzyme, which is required for gastric colonization.
NixA fractionates with the cytoplasmic membrane, and protein cross-linking
studies suggest that NixA functions as a monomer. A preliminary topological model
of NixA with seven transmembrane domains was previously proposed based on
hydropathy, charge dispersion, and homology to other transporters. To test the
proposed topology of NixA and relate critical residues to specific structural
elements, a series of 21 NixA-LacZ and 21 NixA-PhoA fusions were created along
the entire length of the protein. Expression of reporter fusions was confirmed by
Western blotting with beta-galactosidase- and alkaline phosphatase-specific
antisera. The activities of reporter fusions near to and upstream of the
predicted translational initiation demonstrated the presence of an additional
amino-terminal transmembrane domain including a membrane localization signal.
Activities of fusions immediately adjacent to motifs which have been shown to be
requisite for Ni(2+) transport localized these motifs entirely within
transmembrane domains II and III. Fusion activities localized six additional Asp
and Glu residues which reduced Ni(2+) transport by >90% when mutated within or
immediately adjacent to transmembrane domains II, V, VI, and VII. All fusions
strongly support a model of NixA in which the amino and carboxy termini are
located in the cytoplasm and the protein possesses eight transmembrane domains.
PMID- 10692380
TI - Vibrio cholerae VibF is required for vibriobactin synthesis and is a member of
the family of nonribosomal peptide synthetases.
AB - A 7.5-kbp fragment of chromosomal DNA downstream of the Vibrio cholerae
vibriobactin outer membrane receptor, viuA, and the vibriobactin utilization
gene, viuB, was recovered from a Sau3A lambda library of O395 chromosomal DNA. By
analogy with the genetic organization of the Escherichia coli enterobactin gene
cluster, in which the enterobactin biosynthetic and transport genes lie adjacent
to the enterobactin outer membrane receptor, fepA, and the utilization gene, fes,
the cloned DNA was examined for the ability to restore siderophore synthesis to
E. coli ent mutants. Cross-feeding studies demonstrated that an E. coli entF
mutant complemented with the cloned DNA regained the ability to synthesize
enterobactin and to grow in low-iron medium. Sequence analysis of the cloned
chromosomal DNA revealed an open reading frame downstream of viuB which encoded a
deduced protein of greater than 2,158 amino acids, homologous to Yersinia sp.
HMWP2, Vibrio anguillarum AngR, and E. coli EntF. A mutant with an in-frame
deletion of this gene, named vibF, was created with classical V. cholerae strain
O395 by in vivo marker exchange. In cross-feeding studies, this mutant was unable
to synthesize ferric vibriobactin but was able to utilize exogenous siderophore.
Complementation of the mutant with a cloned vibF fragment restored vibriobactin
synthesis to normal. The expression of the vibF promoter was found to be
negatively regulated by iron at the transcriptional level, under the control of
the V. cholerae fur gene. Expression of vibF was not autoregulatory and neither
affected nor was affected by the expression of irgA or viuA. The promoter of vibF
was located by primer extension and was found to contain a dyad symmetric
nucleotide sequence highly homologous to the E. coli Fur binding consensus
sequence. A footprint of purified V. cholerae Fur on the vibF promoter,
overlapping the Fur binding consensus sequence, was observed using DNase I
footprinting. The protein product of vibF is homologous to the multifunctional
nonribosomal protein synthetases and is necessary for the biosynthesis of
vibriobactin.
PMID- 10692381
TI - CTXphi infection of Vibrio cholerae requires the tolQRA gene products.
AB - CTXphi is a lysogenic filamentous bacteriophage that encodes cholera toxin.
Filamentous phages that infect Escherichia coli require both a pilus and the
products of tolQRA in order to enter host cells. We have previously shown that
toxin-coregulated pilus (TCP), a type IV pilus that is an essential Vibrio
cholerae intestinal colonization factor, serves as a receptor for CTXphi. To test
whether CTXphi also depends upon tol gene products to infect V. cholerae, we
identified and inactivated the V. cholerae tolQRAB orthologues. The predicted
amino acid sequences of V. cholerae TolQ, TolR, TolA, and TolB showed significant
similarity to the corresponding E. coli sequences. V. cholerae strains with
insertion mutations in tolQ, tolR, or tolA were reduced in their efficiency of
CTXphi uptake by 4 orders of magnitude, whereas a strain with an insertion
mutation in tolB showed no reduction in CTXphi entry. We could detect CTXphi
infection of TCP(-) V. cholerae, albeit at very low frequencies. However, strains
with mutations in both tcpA and either tolQ, tolR, or tolA were completely
resistant to CTXphi infection. Thus, CTXphi, like the E. coli filamentous phages,
uses both a pilus and TolQRA to enter its host. This suggests that the pathway
for filamentous phage entry into cells is conserved between host bacterial
species.
PMID- 10692382
TI - Glutathione is involved in environmental stress responses in Rhizobium tropici,
including acid tolerance.
AB - The isolation of rhizobial strains which exhibit an intrinsic tolerance to acidic
conditions has been reported and has facilitated studies on the basic mechanisms
underlying acid tolerance. Rhizobium tropici strain CIAT899 displays a high
intrinsic tolerance to acidity and therefore was used in this work to study the
molecular basis of bacterial responses to acid conditions and other environmental
stresses. We generated a collection of R. tropici CIAT899 mutants affected in
acid tolerance using Tn5-luxAB mutagenesis, and one mutant strain (CIAT899-13T2),
which fails to grow under acid conditions, was characterized in detail. Strain
CIAT899-13T2 was found to contain a single Tn5-luxAB insertion in a gene showing
a high degree of similarity with the Escherichia coli gshB gene, encoding the
enzyme glutathione synthetase. Intracellular potassium pools and intracellular pH
levels were found to be lower in the mutant than in the parent. The glutathione
deficient mutant was shown to be sensitive to weak organic acids, osmotic and
oxidative stresses, and the presence of methylglyoxal. Glutathione restores
responses to these stresses almost to wild-type levels. Our data show that in R.
tropici the production of glutathione is essential for growth in extreme
environmental conditions. The mutant strain CIAT899-13T2 induced effective
nodules; however, it was found to be outcompeted by the wild-type strain in
coinoculation experiments.
PMID- 10692383
TI - AcrD of Escherichia coli is an aminoglycoside efflux pump.
AB - AcrD, a transporter belonging to the resistance-nodulation-division family, was
shown to participate in the efflux of aminoglycosides. Deletion of the acrD gene
decreased the MICs of amikacin, gentamicin, neomycin, kanamycin, and tobramycin
by a factor of two to eight, and DeltaacrD cells accumulated higher levels of
[(3)H]dihydrostreptomycin and [(3)H]gentamicin than did the parent strain.
PMID- 10692384
TI - Isolation of an inner membrane-derived subfraction that supports in vitro
replication of a mini-RK2 plasmid in Escherichia coli.
AB - Previous results have demonstrated that the inner, but not the outer, membrane
fraction of Escherichia coli is the site of membrane-associated DNA replication
of plasmid RK2, a broad-host-range plasmid capable of replication in a wide
variety of gram-negative hosts (K. Michaels, J. Mei, and W. Firshein, Plasmid
32:19-31, 1994). To resolve the inner membrane replication site further, the
procedure of Ishidate et al. (K. Ishidate, E. S. Creeger, J. Zrike, S. Deb, G.
Glauner, T. J. MacAlister, and L. I. Rothfield, J. Biol. Chem. 261:428-443, 1986)
was used to separate the inner membrane into a number of subfractions, of which
only one, a small subfraction containing only 10% of the entire membrane, was
found to synthesize DNA inhibited by antibody prepared against the plasmid
encoded initiation protein TrfA. This is the same subfraction that was also found
to bind oriV and TrfA to the greatest extent in filter binding assays (J. Mei, S.
Benashski, and W. Firshein, J. Bacteriol. 177:6766-6772, 1995).
PMID- 10692385
TI - Activation of SoxR by overproduction of desulfoferrodoxin: multiple ways to
induce the soxRS regulon.
AB - The soxRS response, which protects cells against superoxide toxicity, is
triggered by the oxidation of SoxR, a transcription factor. Superoxide excess and
NADPH depletion induce the regulon. Unexpectedly, we found that the
overproduction of desulfoferrodoxin, a superoxide reductase from sulfate-reducing
bacteria, also induced this response. We suggest that desulfoferrodoxin
interferes with the reducing pathway that keeps SoxR in its inactive form.
PMID- 10692386
TI - Nitrate assimilation genes of the marine diazotrophic, filamentous cyanobacterium
Trichodesmium sp. strain WH9601.
AB - A 4.0-kb DNA fragment of Trichodesmium sp. strain WH9601 contained gene sequences
encoding the nitrate reduction enzymes, nirA and narB. A third gene positioned
between nirA and narB encodes a putative membrane protein with similarity to the
nitrate permeases of Bacillus subtilis (NasA) and Emericella nidulans (CrnA). The
gene was shown to functionally complement a DeltanasA mutant of B. subtilis and
was assigned the name napA (nitrate permease). NapA was involved in both nitrate
and nitrite uptake by the complemented B. subtilis cells. napA is distinct from
the nrt genes that encode the nitrate transporter of freshwater cyanobacteria.
PMID- 10692387
TI - Membrane association of the Escherichia coli enterobactin synthase proteins
EntB/G, EntE, and EntF.
AB - The cytosolic proteins EntE, EntF, and EntB/G, which are Escherichia coli enzymes
necessary for the final stage of enterobactin synthesis, are released by osmotic
shock. Here, consistent with the idea that cytoplasmic proteins found in
shockates have an affinity for membranes, a small fraction of each was found in
membrane preparations. Two procedures demonstrated that the enzymes were enriched
in a minor membrane fraction of buoyant density intermediate between that of
cytoplasmic and outer membranes, providing indirect support for the notion that
these proteins have a role in enterobactin excretion as well as synthesis.
PMID- 10692388
TI - The right end of the vir region of an octopine-type Ti plasmid contains four new
members of the vir regulon that are not essential for pathogenesis.
AB - We sequenced the virD-virE, virE-virF, and virF-T-DNA intergenic regions of an
octopine Ti plasmid. Four newly described genes were induced by the vir gene
inducer acetosyringone, two of which are conserved in the nopaline-type Ti
plasmid pTiC58. One gene resembles a family of phosphatase genes. Each of these
genes is dispensable for tumorigenesis.
PMID- 10692389
TI - Mechanism and cellular applications of a green fluorescent protein-based halide
sensor.
AB - We report the application of a targetable green fluorescent protein-based
cellular halide indicator. Fluorescence titrations of the purified recombinant
yellow fluorescent protein YFP-H148Q indicated a pK(a) of 7.14 in the absence of
Cl(-), which increased to 7.86 at 150 mM Cl(-). At pH 7.5, YFP-H148Q fluorescence
decreased maximally by approximately 2-fold with a K(D) of 100 mM Cl(-). YFP
H148Q had a fluorescence lifetime of 3.1 ns that was independent of pH and [Cl(
)]. Circular dichroism and absorption spectroscopy revealed distinct Cl(-)
dependent spectral changes indicating Cl(-)/YFP binding. Stopped-flow kinetic
analysis showed a biexponential time course of YFP-H148Q fluorescence (time
constants <100 ms) in response to changes in pH or [Cl(-)], establishing a 1:1
YFP-H148Q/Cl(-) binding mechanism. Photobleaching analysis revealed a millisecond
triplet state relaxation process that was insensitive to anions and aqueous-phase
quenchers. The anion selectivity sequence for YFP-H148Q quenching (ClO(4)(-)
approximately I(-) > SCN(-) > NO(3)(-) > Cl(-) > Br(-) > formate > acetate)
indicated strong binding of weakly hydrated chaotropic ions. The biophysical data
suggest that YFP-H148Q anion sensitivity involves ground state anion binding to a
site close to the tri-amino acid chromophore. YFP-H148Q transfected mammalian
cells were brightly fluorescent with cytoplasmic/nuclear staining. Ionophore
calibrations indicated similar YFP-H148Q pH and anion sensitivities in cells and
aqueous solutions. Cyclic AMP-regulated Cl(-) transport through plasma membrane
cystic fibrosis transmembrane conductance regulator Cl(-) channels was assayed
with excellent sensitivity from the time course of YFP-H148Q fluorescence in
response to extracellular Cl(-)/I(-) exchange. The green fluorescent protein
based halide sensor described here should have numerous applications, such as
anion channel cloning by screening of mammalian expression libraries and
discovery of compounds that correct the cystic fibrosis phenotype by screening of
combinatorial libraries.
PMID- 10692390
TI - p53 regulates the expression of the tumor suppressor gene maspin.
AB - Maspin has been shown to inhibit tumor cell invasion and metastasis in breast
tumor cells. Maspin expression was detected in normal breast and prostate
epithelial cells, whereas tumor cells exhibited reduced or no expression.
However, the regulatory mechanism of maspin expression remains unknown. We report
here a rapid and robust induction of maspin expression in prostate cancer cells
(LNCaP, DU145, and PC3) and breast tumor cells (MCF7) following wild type p53
expression from an adenovirus p53 expression vector (AdWTp53). p53 activates the
maspin promoter by binding directly to the p53 consensus-binding site present in
the maspin promoter. DNA-damaging agents and cytotoxic drugs induced endogenous
maspin expression in cells containing the wild type p53. Maspin expression was
refractory to the DNA-damaging agents in cells containing mutant p53. These
results, combined with recent studies of the tumor metastasis suppressor gene
KAI1 and plasminogen activator inhibitor 1 (PAI1), define a new category of
molecular targets of p53 that have the potential to negatively regulate tumor
invasion and/or metastasis.
PMID- 10692391
TI - Phosphorylation of a Src kinase at the autophosphorylation site in the absence of
Src kinase activity.
AB - Exposure of cells to oxidants increases the phosphorylation of the Src family
tyrosine protein kinase Lck at Tyr-394, a conserved residue in the activation
loop of the catalytic domain. Kinase-deficient Lck expressed in fibroblasts that
do not express any endogenous Lck has been shown to be phosphorylated at Tyr-394
following H(2)O(2) treatment to an extent indistinguishable from that seen with
wild type Lck. This finding indicates that a kinase other than Lck itself is
capable of phosphorylating Tyr-394. Because fibroblasts express other Src family
members, it remained to be determined whether the phosphorylation of Tyr-394 was
carried out by another Src family kinase or by an unrelated tyrosine protein
kinase. We examined here whether Tyr-394 in kinase-deficient Lck was
phosphorylated following exposure of cells devoid of endogenous Src family kinase
activity to H(2)O(2). Strikingly, treatment of such cells with H(2)O(2) led to
the phosphorylation of Tyr-394 to an extent identical to that seen with wild type
Lck, demonstrating that Src family kinases are not required for H(2)O(2)-induced
phosphorylation of Lck. Furthermore, this efficient phosphorylation of Lck at Tyr
394 in non-lymphoid cells suggests the existence of an ubiquitous activator of
Src family kinases.
PMID- 10692392
TI - VRAP is an adaptor protein that binds KDR, a receptor for vascular endothelial
cell growth factor.
AB - A protein that binds the intracellular domain of KDR (KDR-IC), a receptor for
vascular endothelial cell growth factor (VEGF), was identified by two-hybrid
screening. Two-hybrid mapping showed that the VEGF receptor-associated protein
(VRAP) interacted with tyrosine 951 in the kinase insert domain of KDR. Northern
blot analysis identified multiple VRAP transcripts in peripheral leukocytes,
spleen, thymus, heart, lung, and human umbilical vein endothelial cells (HUVEC).
The predominant VRAP mRNA encodes a 389-amino acid protein that contains an SH2
domain and a C-terminal proline-rich motif. In HUVEC, VEGF promotes association
of VRAP with KDR. Phospholipase C gamma and phosphatidylinositol 3-kinase,
effector proteins that are downstream of KDR and important to VEGF-induced
endothelial cell survival and proliferative responses, associate constitutively
with VRAP. These observations identify VRAP as an adaptor that recruits
cytoplasmic signaling proteins to KDR, which plays an important role in normal
and pathological angiogenesis.
PMID- 10692393
TI - Inositol tetrakisphosphate as a frequency regulator in calcium oscillations in
HeLa cells.
AB - Cellular signaling mediated by inositol (1,4,5)trisphosphate (Ins(1, 4,5)P(3))
results in oscillatory intracellular calcium (Ca(2+)) release. Because the
amplitude of the Ca(2+) spikes is relatively invariant, the extent of the agonist
mediated effects must reside in their ability to regulate the oscillating
frequency. Using electroporation techniques, we show that Ins(1,4,5)P(3),
Ins(1,3,4, 5)P(4), and Ins(1,3,4,6)P(4) cause a rapid intracellular Ca(2+)
release in resting HeLa cells and a transient increase in the frequency of
ongoing Ca(2+) oscillations stimulated by histamine. Two poorly metabolizable
analogs of Ins(1,4,5)P(3), Ins(2,4,5)P(3), and 2,3-dideoxy-Ins(1,4,5)P(3), gave a
single Ca(2+) spike and failed to alter the frequency of ongoing oscillations.
Complete inhibition of Ins(1,4,5)P(3) 3-kinase (IP3K) by either adriamycin or its
specific antibody blocked Ca(2+) oscillations. Partial inhibition of IP3K causes
a significant reduction in frequency. Taken together, our results indicate that
Ins(1,3,4,5)P(4) is the frequency regulator in vivo, and IP3K, which
phosphorylates Ins(1,4, 5)P(3) to Ins(1,3,4,5)P(4), plays a major regulatory role
in intracellular Ca(2+) oscillations.
PMID- 10692394
TI - Apaf-1 oligomerizes into biologically active approximately 700-kDa and inactive
approximately 1.4-MDa apoptosome complexes.
AB - Apaf-1, by binding to and activating caspase-9, plays a critical role in
apoptosis. Oligomerization of Apaf-1, in the presence of dATP and cytochrome c,
is required for the activation of caspase-9 and produces a caspase activating
apoptosome complex. Reconstitution studies with recombinant proteins have
indicated that the size of this complex is very large in the order of
approximately 1.4 MDa. We now demonstrate that dATP activation of cell lysates
results in the formation of two large Apaf-1-containing apoptosome complexes with
M(r) values of approximately 1.4 MDa and approximately 700 kDa. Kinetic analysis
demonstrates that in vitro the approximately 700-kDa complex is produced more
rapidly than the approximately 1.4 MDa complex and exhibits a much greater
ability to activate effector caspases. Significantly, in human tumor monocytic
cells undergoing apoptosis after treatment with either etoposide or N-tosyl-l
phenylalanyl chloromethyl ketone (TPCK), the approximately 700-kDa Apaf-1
containing apoptosome complex was predominately formed. This complex processed
effector caspases. Thus, the approximately 700-kDa complex appears to be the
correctly formed and biologically active apoptosome complex, which is assembled
during apoptosis.
PMID- 10692395
TI - Human PC4 is a substrate-specific inhibitor of RNA polymerase II phosphorylation.
AB - The activity of cyclin-dependent protein kinases (cdks) is physiologically
regulated by phosphorylation, association with the specific cyclin subunits, and
repression by specific cdk inhibitors. All three physiological regulatory
mechanisms are specific for one or more cdks, but none is known to be substrate
specific. In contrast, synthetic cdk peptide inhibitors that specifically inhibit
cdk phosphorylation of only some substrates, "aptamers," have been described.
Here, we show that PC4, a naturally occurring transcriptional coactivator,
competitively inhibits cdk-1, -2, and -7-mediated phosphorylation of the largest
subunit of RNA polymerase II (RNAPII), but it does not inhibit phosphorylation of
other substrates of the same kinases. Interestingly, the phosphorylated form of
PC4 is devoid of kinase inhibitory activity. We also show that wild-type PC4 but
not the kinase inhibitory-deficient mutant of PC4 represses transcription in
vivo. Our results point to a novel role for PC4 as a specific inhibitor of RNAPII
phosphorylation.
PMID- 10692396
TI - Smad6 is a Smad1/5-induced smad inhibitor. Characterization of bone morphogenetic
protein-responsive element in the mouse Smad6 promoter.
AB - Smad6 is an inhibitory Smad that is induced by bone morphogenetic proteins (BMPs)
and interferes with BMP signaling. We have isolated the mouse Smad6 promoter and
identified the regions responsible for transcriptional activation by BMPs. The
proximal BMP-responsive element (PBE) in the Smad6 promoter is important for the
transcriptional activation by BMPs and contains a 28-base pair GC-rich sequence
including four overlapping copies of the GCCGnCGC-like motif, which is a binding
site for Drosophila Mad and Medea. We generated a luciferase reporter construct
(3GC2-Lux) containing three repeats of the GC-rich sequence derived from the PBE.
BMPs and BMP receptors induced transcriptional activation of 3GC2-Lux in various
cell types, and this activation was enhanced by cotransfection of BMP-responsive
Smads, i.e. Smad1 or Smad5. Moreover, direct DNA binding of BMP-responsive Smads
and common-partner Smad4 to the GC-rich sequence of PBE was observed. These
results indicate that the expression of Smad6 is regulated by the effects of BMP
activated Smad1/5 on the Smad6 promoter.
PMID- 10692397
TI - Coordinate copper- and oxygen-responsive Cyc6 and Cpx1 expression in
Chlamydomonas is mediated by the same element.
AB - Chlamydomonas reinhardtii activates the transcription of the Cyc6 and the Cpx1
genes (encoding cytochrome c(6) and coprogen oxidase) in response to copper
deficiency. Mutational analysis of promoter regions of the Cyc6 and Cpx1 genes
revealed a four nucleotide sequence, GTAC, which was absolutely essential for
copper responsiveness. The Cyc6 promoter contains two copper response elements,
each with a functionally important GTAC sequence, whereas the Cpx1 promoter
contains only one. This may contribute to the stronger and more tightly regulated
expression of the Cyc6 gene. Mutation or deletion of sequences flanking the GTACs
implicates additional nucleotides contributing to copper-responsive expression,
but none are absolutely essential. Metal ion selectivity of Cpx1 expression is
identical to that described previously for Cyc6 and is restricted to the copper
deficiency-induced Cpx1 transcript. The Cyc6 and Cpx1 genes are also induced by
oxygen deficiency. Reporter gene constructs indicate that the induction occurs at
the level of transcription and requires the same GTAC sequence that is critical
for copper responsiveness. We suggest that components of the copper-responsive
signal transduction pathway are used for some of the changes in gene expression
in hypoxic cells.
PMID- 10692398
TI - Molecular and functional properties of the human alpha(1G) subunit that forms T
type calcium channels.
AB - We describe here several novel properties of the human alpha(1G) subunit that
forms T-type calcium channels. The partial intron/exon structure of the
corresponding gene CACNA1G was defined and several alpha(1G) isoforms were
identified, especially two isoforms that exhibit a distinct III-IV loop: alpha(1G
a) and alpha(1G-b). Northern blot and dot blot analyses indicated that alpha(1G)
mRNA is predominantly expressed in the brain, especially in thalamus, cerebellum,
and substantia nigra. Additional experiments have also provided evidence that
alpha(1G) mRNA is expressed at a higher level during fetal life in nonneuronal
tissues (i.e. kidney, heart, and lung). Functional expression in HEK 293 cells of
a full-length cDNA encoding the shortest alpha(1G) isoform identified to date,
alpha(1G-b), resulted in transient, low threshold activated Ca(2+) currents with
the expected permeability ratio (I(Sr) > I(Ca) >/= I(Ba)) and channel conductance
( approximately 7 pS). These properties, together with slowly deactivating tail
currents, are typical of those of native T-type Ca(2+) channels. This alpha(1G)
related current was inhibited by mibefradil (IC(50) = 2 microM) and weakly
blocked by Ni(2+) ions (IC(50) = 148 microM) and amiloride (IC(50) > 1 mM). We
showed that steady state activation and inactivation properties of this current
can generate a "window current" in the range of -65 to -55 mV. Using neuronal
action potential waveforms, we show that alpha(1G) channels produce a massive and
sustained Ca(2+) influx due to their slow deactivation properties. These latter
properties would account for the specificity of Ca(2+) influx via T-type channels
that occurs in the range of physiological resting membrane potentials, differing
considerably from the behavior of other Ca(2+) channels.
PMID- 10692399
TI - Evidence for interactions between helices 5 and 8 and a role for the interdomain
loop in tetracycline resistance mediated by hybrid Tet proteins.
AB - An interdomain hybrid Tet protein consisting of a class C alpha domain and a
class B beta domain (Tet(C/B)) lacks detectable efflux ability and provides only
minimal levels of resistance to tetracycline (Tc) (3 microg/ml) compared with
intact class B (256 microg/ml) and class C (64 microg/ml). Twenty-one
independently isolated mutants of the Tet(C/B) protein with increased Tc
resistance were generated by random chemical mutagenesis. Nine mutants with a Glu
substitution for Gly-152 in helix 5 of the class C alpha domain produced a
resistance of 48 microg/ml, whereas another 9 with an Asp replacement of Gly-247
in helix 8 of the class B beta domain mediated resistance at 32 microg/ml. The
third type of mutation, found in 3 mutants expressing 24 microg/ml resistance,
was a S202F replacement in the putative interdomain cytoplasmic loop of Tet(C/B).
The latter underscores a previously unappreciated function of the interdomain
cytoplasmic loop. All three types of Tet(C/B) mutant proteins were expressed in
amounts comparable with that of the original protein and demonstrated restored
energy-dependent efflux of tetracycline. Site-directed mutational analysis
demonstrated that a Gly-247 to Asn mutation could also facilitate Tc resistance
by the Tet(C/B) hybrid, and a negatively charged side chain at position 152 was
required for Tet(C/B) activity. These mutations appear to promote the necessary
functional interactions between the interclass domains that do not occur in the
Tet(C/B) hybrid protein and suggest a direct association between helix 5 and
helix 8 in the function of Tet efflux proteins.
PMID- 10692400
TI - Identification of a key region of kinin B(1) receptor for high affinity binding
of peptide antagonists.
AB - To investigate the molecular basis for the specificity of ligand recognition in
human kinin B(1) (B(1)R) and B(2) (B(2)R) receptors, we constructed a series of
chimeric receptors by progressively replacing, from the N to the C terminus, the
human B(2)R domains by their B(1) counterparts. The chimeric construct possessing
the C-terminal tail and the transmembrane domain VII (TM VII) of the B(2)R
(construct 6) displayed 7- and 20- fold decreased affinities for the B(1) agonist
[(3)H]desArg(10)-kallidin (desArg(10)-KD) and the B(1) antagonist
[(3)H]desArg(10)-[Leu(9)]-KD respectively, as compared with the wild-type B(1)R.
Moreover, the substitution of the B(1) TM VII by its B(2) homologue TM increased
the affinity for the pseudopeptide antagonists, Hoe140 and NPC 567. High affinity
for desArg(10)-KD binding was fully regained when the B(2) residue Thr(287) was
replaced in construct 6 by the corresponding B(1) Leu(294) residue. When the B(2)
residue Tyr(295) was exchanged with the corresponding B(1) Phe(302), high
affinity binding for both agonist and antagonist was recovered. Moreover, the
L294T and F302Y mutant B(1)R exhibited 69- and 6.5-fold increases, respectively,
in their affinities for the B(2) receptor antagonist, Hoe140. Therefore we
proposed that Leu(294) and Phe(302) residues, which may not be directly involved
in the binding of B(1)R ligands and, hence, their Thr(287) and Tyr(295) B(2)
counterparts, are localized in a receptor region, which plays a pivotal role in
the binding selectivity of the peptide or pseudopeptide kinin ligands.
PMID- 10692401
TI - The multifunctional character of a geminivirus replication protein is reflected
by its complex oligomerization properties.
AB - Tomato golden mosaic virus (TGMV), a member of the geminivirus family, encodes
one essential replication protein, AL1, and recruits the rest of the DNA
replication apparatus from its plant host. TGMV AL1 is an oligomeric protein that
binds double-stranded DNA and catalyzes cleavage and ligation of single-stranded
DNA. The oligomerization domain, which is required for DNA binding, maps to a
region that displays strong sequence and structural homology to other geminivirus
Rep proteins. To assess the importance of conserved residues, we generated a
series of site-directed mutations and analyzed their impact on AL1 function in
vitro and in vivo. Two-hybrid experiments revealed that mutation of amino acids
157-159 inhibited AL1-AL1 interactions, whereas mutations at nearby residues
reduced complex stability. Changes at positions 157-159 also disrupted
interaction between the full-length mutant protein and a glutathione S
transferase-AL1 oligomerization domain fusion in insect cells. The mutations had
no detectable effect on oligomerization when both proteins contained full-length
AL1 sequences, indicating that AL1 complexes can be stabilized by amino acids
outside of the oligomerization domain. Nearly all of the oligomerization domain
mutants were inhibited or severely attenuated in their ability to support AL1
directed viral DNA replication. In contrast, the same mutants were enhanced for
AL1-mediated transcriptional repression. The replication-defective AL1 mutants
also interfered with replication of a TGMV A DNA encoding wild type AL1. Full
length mutant AL1 was more effective in the interference assays than truncated
proteins containing the oligomerization domain. Together, these results suggested
that different AL1 complexes mediate viral replication and transcriptional
regulation and that replication interference involves multiple domains of the AL1
protein.
PMID- 10692402
TI - Enhanced electron flux and reduced calmodulin dissociation may explain "calcium
independent" eNOS activation by phosphorylation.
AB - Bovine endothelial nitric oxide synthase (eNOS) is phosphorylated directly by the
protein kinase Akt at serine 1179. Mutation of this residue to the negatively
charged aspartate (S1179D eNOS) increases nitric oxide (NO) production
constitutively, in the absence of agonist challenge. Here, we examine the
potential mechanism of how aspartate at 1179 increases eNOS activity using
purified proteins. Examination of NO production and cytochrome c reduction
resulted in no substantial changes in the K(m)/EC(50) for L-arginine, calmodulin,
and calcium, whereas there was a 2-fold increase in the rate of NO production for
S1179D and a 2-4-fold increase in reductase activity (based on cytochrome c
reduction). The observed increase in activity for both assays of NOS function
indicates that a faster rate of electron flux through the reductase domain is
likely the rate-limiting step in NO formation from eNOS. In addition, S1179D eNOS
did show an increased resistance to inactivation by EGTA compared with wild type
eNOS. These results suggest that a negative charge imposed at serine 1179, either
by phosphorylation or by replacement with aspartate, increases eNOS catalytic
activity by increasing electron flux at the reductase domain and by reducing
calmodulin dissociation from activated eNOS when calcium levels are low.
PMID- 10692403
TI - Free [ADP] and aerobic muscle work follow at least second order kinetics in rat
gastrocnemius in vivo.
AB - The relationship between free cytosolic [ADP] (and [P(i)]) and steady-state
aerobic muscle work in rat gastrocnemius muscle in vivo using (31)P NMR was
investigated. Anesthetized rats were ventilated and placed in a custom-built
cradle fitted with a force transducer that could be placed into a 7-tesla NMR
magnet. Muscle work was induced by supramaximal sciatic nerve stimulation that
activated all fibers. Muscles were stimulated at 0.1, 0.2, 0.3, 0.4, 0.5, 0.8,
1.0, and 2.0 Hz until twitch force, phosphocreatine, and P(i) were unchanged
between two consecutive spectra acquired in 4-min blocks (8-12 min). Parallel
bench experiments were performed to measure total tissue glycogen, lactate, total
creatine, and pyruvate in freeze-clamped muscles after 10 min of stimulation at
each frequency. Up to 0.5 Hz, there was no significant change in muscle glycogen,
lactate, and the lactate/pyruvate ratios between 8-12 min. At 0.8 Hz, there was a
17% fall in glycogen and a 65% rise in the muscle lactate with a concomitant fall
in pH. Above this frequency, glycogen fell rapidly, lactate continued to rise,
and ATP and pH declined. On the basis of these force and metabolic measurements,
we estimated the maximal mitochondrial capacity (V(max)) to be 0.8 Hz. Free [ADP]
was then calculated at each submaximal workload from measuring all the reactants
of the creatine kinase equilibrium after adjusting the K'(CK) to the muscle temp
(30 degrees C), pH, and pMg. We show that ADP (and P(i)) and tension-time
integral follow a Hill relationship with at least a second order function. The
K(0.5) values for free [ADP] and [P(i)] were 48 microM and 9 mM, respectively.
Our data did not fit any form of the Michaelis-Menten equation. We therefore
conclude that free cytosolic [ADP] and [P(i)] could potentially control steady
state oxidative phosphorylation in skeletal muscle in vivo.
PMID- 10692404
TI - Regulation of cloned cardiac L-type calcium channels by cGMP-dependent protein
kinase.
AB - We have studied the effect of 8-bromo-cyclic GMP (8-Br-cGMP) on cloned cardiac L
type calcium channel currents to determine the site and mechanism of action
underlying the functional effect. Rabbit cardiac alpha(1C) subunit, in the
presence or absence of beta(1) subunit (rabbit skeletal muscle) or beta(2)
subunit (rat cardiac/brain), was expressed in Xenopus oocytes, and two-electrode
voltage-clamp recordings were made 2 or 3 days later. Application of 8-Br-cGMP
caused decreases in calcium channel currents in cells expressing the alpha(1C)
subunit, whether or not a beta subunit was co-expressed. No inhibition of
currents by 8-Br-cGMP was observed in the presence of the protein kinase G
inhibitor KT5823. Substitutions of serine residues by alanine were made at
residues Ser(533) and Ser(1371) on the alpha(1C) subunit. As for wild type, the
mutant S1371A exhibited inhibition of calcium channel currents by 8-Br-cGMP,
whereas no effect of 8-Br-cGMP was observed for mutant S533A. Inhibition of
calcium currents by 8-Br-cGMP was also observed in the additional presence of the
alpha(2)delta subunit for wild type channels but not for the mutant S533A. These
results indicate that cGMP causes inhibition of L-type calcium channel currents
by phosphorylation of the alpha(1C) subunit at position Ser(533) via the action
of protein kinase G.
PMID- 10692405
TI - Transient translocation and activation of protein phosphatase 2A during mast cell
secretion.
AB - Okadaic acid inhibits secretion from mast cells, suggesting a regulatory role for
protein Ser/Thr phosphatases type I (PP1) and/or 2A (PP2A) in the secretory
process. In unstimulated RBL-2H3 cells, okadaic acid pretreatment inhibited PP2A
activity in both cytosol and membrane fractions, but inhibition of secretion
correlated with inhibition of membrane-bound rather than cytosolic PP2A activity.
Okadaic acid had very little effect on PP1 activity. Stimulation of RBL-2H3 cells
by antigen led to the activity and amount of PP2A in the membrane fraction
increasing nearly 2-fold. In contrast, there was little change in the activity or
distribution of PP1. Importantly, the translocation of PP2A was transient,
coinciding with or marginally preceding the peak rate of secretion, suggesting a
link between PP2A translocation, activity, and secretion. Phorbol 12-myristate 13
acetate plus the calcium ionophore A23187 induced a slower, prolonged rate of
secretion that coincided with a similarly protracted translocation of PP2A to the
membrane fraction. PP2A translocation is not the only event required for
secretion as translocation was also induced by phorbol 12-myristate 13-acetate,
without resulting in secretion. These results indicate that increased protein
dephosphorylation in the membrane fraction mediated by PP2A is required for mast
cell secretion. To our knowledge, this is the first demonstration of a signal
mediated, rapid, transient translocation and activation of PP2A in membranes in
any system.
PMID- 10692406
TI - ARA9 modifies agonist signaling through an increase in cytosolic aryl hydrocarbon
receptor.
AB - The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor
that mediates the effects of agonists like 2,3, 7,8-tetrachlorodibenzo-p-dioxin.
In the current model for AHR signaling, the unliganded receptor is found in the
cytosol as part of a complex with a dimer of the 90-kDa heat shock protein and an
immunophilin-like molecule, ARA9. In yeast, expression of ARA9 results in an
increase in the maximal agonist response and a leftward shift in the AHR dose
response curve. To better understand the mechanism by which ARA9 modifies AHR
signal transduction, we performed a series of coexpression experiments in yeast
and mammalian cells. Our results demonstrate that ARA9's influence on AHR
signaling is not due to inhibition of a membrane pump or modification of the
receptor's transactivation properties. Using receptor photoaffinity labeling
experiments, we were able to show that ARA9 enhances AHR signal transduction by
increasing the available AHR binding sites within the cytosolic compartment of
the cell. Our evidence suggests that ARA9's effects are related to its role as a
cellular chaperone; i.e. we observed that expression of ARA9 increases the
fraction of AHR in the cytosol and also stabilized the receptor under heat
stress.
PMID- 10692407
TI - Membrane perturbation and fusion pore formation in influenza hemagglutinin
mediated membrane fusion. A new model for fusion.
AB - Low pH-induced fusion mediated by the hemagglutinin (HA) of influenza virus
involves conformational changes in the protein that lead to the insertion of a
"fusion peptide" domain of this protein into the target membrane and is thought
to perturb the membrane, triggering fusion. By using whole virus, purified HA, or
HA ectodomains, we found that shortly after insertion, pores of less than 26 A in
diameter were formed in liposomal membranes. As measured by a novel assay, these
pores stay open, or continue to close and open, for minutes to hours and persist
after pH neutralization. With virus and purified HA, larger pores, allowing the
leakage of dextrans, were seen at times well after insertion. For virus, dextran
leakage was simultaneous with lipid mixing and the formation of "fusion pores,"
allowing the transfer of dextrans from the liposomal to the viral interior or
vice versa. Pores did not form in the viral membrane in the absence of a target
membrane. Based on these data, we propose a new model for fusion, in which HA
initially forms a proteinaceous pore in the target, but not in the viral
membrane, before a lipidic hemifusion intermediate is formed.
PMID- 10692408
TI - HeLa cells are phenotypically limiting in cyclin E/CDK2 for efficient human
papillomavirus DNA replication.
AB - Human papillomaviral (HPV) origin-containing plasmids replicate efficiently in
human 293 cells or cell extracts in the presence of HPV origin-recognition
protein E2 and replication initiation protein E1, whereas cervical carcinoma
derived, HPV-18-positive HeLa cells or cell extracts support HPV DNA replication
poorly. We recently showed that HPV-11 E1 interacts with cyclin/cyclin-dependent
kinase (cdk) complexes through an RXL motif and is a substrate for these kinases.
E1 mutations in this motif or in candidate cdk phosphorylation sites are impaired
in replication, suggesting a role for cdks in HPV replication. We now demonstrate
that one limiting activity in HeLa cells is cyclin E/CDK2. Purified cyclin E/CDK2
or cyclin E/CDK3 complex, but not other cdks, partially complemented HeLa cell
extracts. Cyclin E/CDK2 expression vectors also enhanced transient HPV
replication in HeLa cells. HeLa cell-derived HPV-18 E1 protein is truncated at
the carboxyl terminus but can associate with cyclin E/CDK2. This truncated E1 was
replication-incompetent and inhibited cell-free HPV replication. These results
indicate that HeLa cells are phenotypically limiting in cyclin E/CDK2 for
efficient HPV replication, most likely due to sequestration by the endogenous,
defective HPV-18 E1 protein. Further analyses of the regulation of HPV E1 and HPV
replication by cyclin E may shed light on the roles of cyclin E/CDK2 in cellular
DNA replication.
PMID- 10692409
TI - Mutational analysis of basic residues in the rat vesicular acetylcholine
transporter. Identification of a transmembrane ion pair and evidence that
histidine is not involved in proton translocation.
AB - The function of positively charged residues and the interaction of positively and
negatively charged residues of the rat vesicular acetylcholine transporter
(rVAChT) were studied. Changing Lys-131 in transmembrane domain helix 2 (TM2) to
Ala or Leu eliminated transport activity, with no effect on vesamicol binding.
However, replacement by His or Arg retained transport activity, suggesting a
positive charge in this position is critical. Mutation of His-444 in TM12 or His
413 in the cytoplasmic loop between TM10 and TM11 was without effect on ACh
transport, but vesamicol binding was reduced with His-413 mutants. Changing His
338 in TM8 to Ala or Lys did not effect ACh transport, however replacement with
Cys or Arg abolished activity. Mutation of both of the transmembrane histidines
or all three of the luminal loop histidines showed no change in acetylcholine
transport. The mutant H338A/D398N between oppositely charged residues in
transmembrane domains showed no vesamicol binding, however the charge reversal
mutant H338D/D398H restored binding. This suggests that His-338 forms an ion pair
with Asp-398. The charge neutralizing mutant K131A/D425N or the charge exchanged
mutant K131D/D425K did not restore ACh transport. Taken together these results
provide new insights into the tertiary structure in VAChT.
PMID- 10692410
TI - RNA and DNA hydrolysis are catalyzed by the influenza virus endonuclease.
AB - The influenza virus polymerase complex contains a metal ion-dependent
endonuclease activity, which generates short capped RNA primer molecules from
capped RNA precursors. Previous studies have provided evidence for a two-metal
ion mechanism of RNA cleavage, and the data are consistent with a direct
interaction of a divalent metal ion with the catalytic water molecule. To refine
the model of this active site, we have generated a series of DNA, RNA, and DNA
RNA chimeric molecules to study the role of the 2'-hydroxy groups on nucleic acid
substrates of the endonuclease. We could observe specific cleavage of nucleic
acid substrates devoid of any 2'-hydroxy groups if they contained a cap structure
(m7GpppG) at the 5'-end. The capped DNA endonuclease products were functional as
primers for transcription initiation by the influenza virus polymerase. The
apparent cleavage rates were about 5 times lower with capped DNA substrates as
compared with capped RNA substrates. Cleavage rates with DNA substrates could be
increased to RNA levels by substituting the deoxyribosyl moieties immediately 5'
and 3' of the cleavage site with ribosyl moieties. Similarly, cleavage rates of
RNA substrates could be lowered to DNA levels by exchanging the same two ribosyl
groups with deoxyribosyl groups at the cleavage site. These results demonstrate
that the 2'-hydroxy groups are not essential for binding and cleavage of nucleic
acids by the influenza virus endonuclease, but small differences of the nucleic
acid conformation in the endonuclease active site can influence the overall rate
of hydrolysis. The observed relative cleavage rates with DNA and RNA substrates
argue against a direct interaction of a catalytic metal ion with a 2'-hydroxy
group in the endonuclease active site.
PMID- 10692411
TI - Diffusible ligand all-trans-retinal activates opsin via a palmitoylation
dependent mechanism.
AB - In rhodopsin's function as a photoreceptor, 11-cis-retinal is covalently bound to
Lys(296) via a protonated Schiff base. 11-cis/all-trans photoisomerization and
relaxation through intermediates lead to the metarhodopsin II photoproduct, which
couples to transducin (G(t)). Here we have analyzed a different signaling state
that arises from noncovalent binding of all-trans-retinal (atr) to the
aporeceptor opsin and enhances the very low opsin activity by several orders of
magnitude. Like with metarhodopsin II, coupling of G(t) to opsin-atr is sensitive
to competition by synthetic peptides from the COOH termini of both G(t)alpha and
G(t)gamma. However, atr does not compete with 11-cis-retinal incorporation into
the Lys(296) binding site and formation of the light-sensitive pigment. Blue
light illumination fails to photorevert opsin-atr to the ground state. Thus
noncovalently bound atr has no access to the light-dependent binding site and
reaction pathway. Moreover, in contrast to light-dependent signaling, removal of
the palmitoyl anchors at Cys(322) and Cys(323) in the rhodopsin COOH terminus
impairs the atr-stimulated activity. Repalmitoylation by autoacylation with
palmitoyl-coenzyme A restores most of the original activity. We hypothesize that
the palmitoyl moieties are part of a second binding pocket for the chromophore,
mediating hydrophobic interactions that can activate a large part of the
catalytic receptor/G-protein interface.
PMID- 10692412
TI - cDNA cloning, purification, and characterization of mouse liver selenocysteine
lyase. Candidate for selenium delivery protein in selenoprotein synthesis.
AB - Selenocysteine lyase (SCL) (EC 4.4.1.16) is a pyridoxal 5'-phosphate-dependent
enzyme that specifically catalyzes the decomposition of L-selenocysteine to L
alanine and elemental selenium. The enzyme was proposed to function as a selenium
delivery protein to selenophosphate synthetase in selenoprotein biosynthesis
(Lacourciere, G. M., and Stadtman, T. C. (1998) J. Biol. Chem. 273, 30921-30926).
We purified SCL from pig liver and determined its partial amino acid sequences.
Mouse cDNA clones encoding peptides resembling pig SCL were found in the
expressed sequence tag data base, and their sequences were used as probes to
isolate full-length mouse liver cDNA. The cDNA for mouse SCL (mSCL) was
determined to be 2,172 base pairs in length, containing an open reading frame
encoding a polypeptide chain of 432 amino acid residues (M(r) 47, 201). We also
determined the sequence of the N-terminal region of putative human SCL. These
enzymes were shown to be distantly related in primary structure to NifS, which
catalyzes the desulfurization of L-cysteine to provide sulfur for iron-sulfur
clusters. The recombinant mSCL overproduced in Escherichia coli was a homodimer
with the subunit M(r) of 47,000. The enzyme was pyridoxal phosphate-dependent and
highly specific to L-selenocysteine (the k(cat)/K(m) value for L-selenocysteine
was about 4,200 times higher than that for L-cysteine). Reverse transcriptase
polymerase chain reaction and Western blot analyses revealed that mSCL is
cytosolic and predominantly exists in the liver, kidney, and testis, where mouse
selenophosphate synthetase is also abundant, supporting the view that mSCL
functions in cooperation with selenophosphate synthetase in selenoprotein
synthesis. This is the first report of the primary structure of mammalian SCL.
PMID- 10692413
TI - Biosynthetic studies of the glycopeptide teicoplanin by (1)H and (13)C NMR.
AB - The biosynthesis of the glycopeptide antibiotic teicoplanin was studied by
growing a teicoplanin producing strain of Actinoplanes teichomyceticus (ATCC
31121) on glucose containing either 34.0% [1-(13)C]glucose or 9.7% [U
(13)C]glucose. The fractional enrichment pattern of teicoplanin produced in the
medium containing [1-(13)C]glucose was obtained from a one-dimensional (13)C
spectrum. The enrichment pattern showed characteristic peaks indicating that
amino acids 3 and 7 are derived from acetate, whereas amino acids 1, 2, 4, 5, and
6 are derived from tyrosine. Multiplet structures in heteronuclear single quantum
coherence spectra of teicoplanin produced in the medium containing [U
(13)C]glucose showed characteristic coupling patterns supporting these results.
Fractional enrichment patterns and multiplet structures of the three sugars in
teicoplanin showed that about 50% of the sugars have the same labeling pattern as
the glucose substrate whereas the rest have a labeling pattern showing that they
are reassembled, probably from precursors in the primary metabolism.
PMID- 10692414
TI - Distant downstream sequence determinants can control N-tail translocation during
protein insertion into the endoplasmic reticulum membrane.
AB - We have studied the membrane insertion of ProW, an Escherichia coli inner
membrane protein with seven transmembrane segments and a large periplasmic N
terminal tail, into endoplasmic reticulum (ER)-derived dog pancreas microsomes.
Strikingly, significant levels of N-tail translocation is seen only when a
minimum of four of the transmembrane segments are present; for constructs with
fewer transmembrane segments, the N-tail remains mostly nontranslocated and the
majority of the molecules adopt an "inverted" topology where normally
nontranslocated parts are translocated and vice versa. N-tail translocation can
also be promoted by shortening of the N-tail and by the addition of positively
charged residues immediately downstream of the first trasnmembrane segment. We
conclude that as many as four consecutive transmembrane segments may be
collectively involved in determining membrane protein topology in the ER and that
the effects of downstream sequence determinants may vary depending on the size
and charge of the N-tail. We also provide evidence to suggest that the ProW N
tail is translocated across the ER membrane in a C-to-N-terminal direction.
PMID- 10692415
TI - Hydrolysis of nucleoside triphosphates other than ATP by nitrogenase.
AB - The hydrolysis of ATP to ADP and P(i) is an integral part of all substrate
reduction reactions catalyzed by nitrogenase. In this work, evidence is presented
that nitrogenases isolated from Azotobacter vinelandii and Clostridium
pasteurianum can hydrolyze MgGTP, MgITP, and MgUTP to their respective nucleoside
diphosphates at rates comparable to those measured for MgATP hydrolysis. The
reactions were dependent on the presence of both the iron (Fe) protein and the
molybdenum-iron (MoFe) protein. The oxidation state of nitrogenase was found to
greatly influence the nucleotide hydrolysis rates. MgATP hydrolysis rates were 20
times higher under dithionite reducing conditions (approximately 4,000 nmol of
MgADP formed per min/mg of Fe protein) as compared with indigo disulfonate
oxidizing conditions (200 nmol of MgADP formed per min/mg of Fe protein). In
contrast, MgGTP, MgITP, and MgUTP hydrolysis rates were significantly higher
under oxidizing conditions (1,400-2,000 nmol of MgNDP formed per min/mg of Fe
protein) as compared with reducing conditions (80-230 nmol of MgNDP formed per
min/mg of Fe protein). The K(m) values for MgATP, MgGTP, MgUTP, and MgITP
hydrolysis were found to be similar (330-540 microM) for both the reduced and
oxidized states of nitrogenase. Incubation of Fe and MoFe proteins with each of
the MgNTP molecules and AlF(4)(-) resulted in the formation of non-dissociating
protein-protein complexes, presumably with trapped AlF(4)(-) x MgNDP. The
implications of these results in understanding how nucleotide hydrolysis is
coupled to substrate reduction in nitrogenase are discussed.
PMID- 10692416
TI - Effects of interferon-gamma and lipopolysaccharide on macrophage iron metabolism
are mediated by nitric oxide-induced degradation of iron regulatory protein 2.
AB - Iron regulatory proteins (IRP-1 and IRP-2) control the synthesis of transferrin
receptors (TfR) and ferritin by binding to iron-responsive elements, which are
located in the 3'-untranslated region and the 5'-untranslated region of their
respective mRNAs. Cellular iron levels affect binding of IRPs to iron-responsive
elements and consequently expression of TfR and ferritin. Moreover, NO(*), a
redox species of nitric oxide that interacts primarily with iron, can activate
IRP-1 RNA binding activity resulting in an increase in TfR mRNA levels. Recently
we found that treatment of RAW 264.7 cells (a murine macrophage cell line) with
NO(+) (nitrosonium ion, which causes S-nitrosylation of thiol groups) resulted in
a rapid decrease in RNA binding of IRP-2 followed by IRP-2 degradation, and these
changes were associated with a decrease in TfR mRNA levels (Kim, S., and Ponka,
P. (1999) J. Biol. Chem. 274, 33035-33042). In this study, we demonstrated that
stimulation of RAW 264.7 cells with lipopolysaccharide (LPS) and interferon-gamma
(IFN-gamma) increased IRP-1 binding activity, whereas RNA binding of IRP-2
decreased and was followed by a degradation of this protein. Moreover, the
decrease of IRP-2 binding/protein levels was associated with a decrease in TfR
mRNA levels in LPS/IFN-gamma-treated cells, and these changes were prevented by
inhibitors of inducible nitric oxide synthase. Furthermore, LPS/IFN-gamma
stimulated RAW 264.7 cells showed increased rates of ferritin synthesis. These
results suggest that NO(+)-mediated degradation of IRP-2 plays a major role in
iron metabolism during inflammation.
PMID- 10692417
TI - Reconstitution of the Ste24p-dependent N-terminal proteolytic step in yeast a
factor biogenesis.
AB - The yeast mating pheromone a-factor precursor contains an N-terminal extension
and a C-terminal CAAX motif within which multiple posttranslational processing
events occur. A recently discovered component in a-factor processing is
Ste24p/Afc1p, a multispanning endoplasmic reticulum membrane protein that
contains an HEXXH metalloprotease motif. Our in vivo genetic characterization of
this protein has demonstrated roles for Ste24p in both the N-terminal and C
terminal proteolytic processing of the a-factor precursor. Here, we present
evidence that the N-terminal proteolysis of the a-factor precursor P1 can be
accurately reconstituted in vitro using yeast membranes. We show that this
activity is dependent on Ste24p and is abolished by mutation of the Ste24p HEXXH
metalloprotease motif or by mutation of the a-factor P1 substrate at a residue
adjacent to the N-terminal P1 cleavage site. We also demonstrate that N-terminal
proteolysis of the P1 a-factor precursor requires Zn(2+) as a co-factor and can
be inhibited by the addition of the metalloprotease inhibitor 1,10
orthophenanthroline. Our results are consistent with Ste24p itself being the P1-
>P2 a-factor protease or a limiting activator of this activity. Interestingly, we
also show that the human Ste24 homolog expressed in yeast can efficiently promote
the N-terminal processing of a-factor in vivo and in vitro, thus establishing a
factor as a surrogate substrate in the absence of known human substrates. The
results reported here, together with the previously reported in vitro
reconstitution of Ste24p-dependent CAAX processing, provide a system for
examining the potential bifunctional roles of yeast Ste24p and its homologs.
PMID- 10692418
TI - Substitution of leucine 28 with histidine in the Escherichia coli transcription
factor FNR results in increased stability of the [4Fe-4S](2+) cluster to oxygen.
AB - To understand the role of the [4Fe-4S](2+) cluster in controlling the activity of
the Escherichia coli transcription factor FNR (fumarate nitrate reduction) during
changes in O(2) availability, we have characterized a mutant FNR protein
containing a substitution of Leu-28 with His (FNR-L28H) which, unlike its wild
type (WT) counterpart, is functional under aerobic growth conditions. The His-28
substitution appears to stabilize the [4Fe-4S](2+) cluster of FNR-L28H in the
presence of O(2) because air-exposed FNR-L28H did not undergo the rapid [4Fe
4S](2+) to [2Fe-2S](2+) cluster conversion or concomitant loss in site-specific
DNA binding and dimerization, which are characteristic of WT-FNR under these
conditions. This increased cluster stability was not a result of His-28 replacing
the WT-FNR cluster ligands because substitution of any of these four Cys residues
(cysteine 20, 23, 29, or 122) with Ser resulted in [4Fe-4S](2+) cluster-deficient
preparations of FNR-L28H. The Mossbauer spectra of FNR-L28H indicated that the
coordination environment of the [4Fe-4S](2+) cluster did not differ from that of
WT-FNR. Whole cell Mossbauer spectroscopy showed that aerobically grown cells
overexpressing FNR-L28H had levels of the FNR species containing the [4Fe-4S](2+)
cluster similar to those of cells grown under anaerobic conditions. Thus, the
increase in cluster stability is sufficient to allow accumulation of the [4Fe
4S](2+) cluster form of FNR-L28H under aerobic conditions and provides a
reasonable explanation for why this mutant protein is functional under aerobic
growth conditions. From these results, we present a model to explain how WT-FNR
is normally inactivated under aerobic growth conditions.
PMID- 10692419
TI - Identification and characterization of a novel cAMP receptor protein in the
cyanobacterium Synechocystis sp. PCC 6803.
AB - Three open reading frames of Synechocystis sp. PCC 6803 encoding a domain
homologous with the cAMP binding domain of bacterial cAMP receptor protein were
analyzed. These three open reading frames, sll1371, sll1924, and slr0593, which
were named sycrp1, sycrp2, and sypk, respectively, were expressed in Escherichia
coli as His-tagged or glutathione S-transferase fusion proteins and purified, and
their biochemical properties were investigated. The results obtained for
equilibrium dialysis measurements using these recombinant proteins suggest that
SYCRP1 and SYPK show a binding affinity for cAMP while SYCRP2 does not. The
dissociation constant of His-tagged SYCRP1 for cAMP is approximately 3 microM. A
cross-linking experiment using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide
revealed that His-tagged SYCRP1 forms a homodimer, and the presence or absence of
cAMP does not affect the formation of the homodimer. The amino acid sequence
reveals that SYCRP1 has a domain similar to the DNA binding domain of bacterial
cAMP receptor protein in the COOH-terminal region. Consistent with this, His
tagged SYCRP1 forms a complex with DNA that contains the consensus sequence for
E. coli cAMP receptor protein in the presence of cAMP. These results strongly
suggest that SYCRP1 is a novel cAMP receptor protein.
PMID- 10692420
TI - Retroviral transfection of Madin-Darby canine kidney cells with human MDR1
results in a major increase in globotriaosylceramide and 10(5)- to 10(6)-fold
increased cell sensitivity to verocytotoxin. Role of p-glycoprotein in glycolipid
synthesis.
AB - Retroviral infection of the Madin-Darby canine kidney (MDCK) renal cell line with
human MDR1 cDNA, encoding the P-glycoprotein (P-gp) multidrug resistance efflux
pump, induces a major accumulation of the glycosphingolipid (GSL),
globotriaosylceramide (Galalpha1-4Galbeta1-4glucosylceramide-Gb(3)), the receptor
for the E. coli-derived verotoxin (VT), to effect a approximately million-fold
increase in cell sensitivity to VT. The shorter chain fatty acid isoforms of
Gb(3) (primarily C16 and C18) are elevated and VT is internalized to the
endoplasmic reticulum/nuclear envelope as we have reported for other
hypersensitive cell lines. P-gp (but not MRP) inhibitors, e.g. ketoconazole or
cyclosporin A (CsA) prevented the increased Gb(3) and VT sensitivity, concomitant
with increased vinblastine sensitivity. Gb(3) synthase was not significantly
elevated in MDR1-MDCK cells and was not affected by CsA. In MDR1-MDCK cells,
synthesis of fluorescent N-[7-(4-nitrobenzo-2-oxa-1,3-diazole)]-aminocaproyl
(NBD)-lactosylceramide (LacCer) and NBD-Gb(3) via NBD-glucosylceramide (GlcCer)
from exogenous NBD-C(6)-ceramide, was prevented by CsA. We therefore propose that
P-gp can mediate GlcCer translocation across the bilayer, from the cytosolic face
of the Golgi to the lumen, to provide increased substrate for the lumenal
synthesis of LacCer and subsequently Gb(3). These results provide a molecular
mechanism for the observed increased sensitivity of multidrug-resistant tumors to
VT and emphasize the potential of verotoxin as an antineoplastic. Two strains (I
and II) of MDCK cells, which differ in their glycolipid profile, have been
described. The original MDR1-MDCK parental cell was not specified, but the MDR1
MDCK GSL phenotype and glycolipid synthase activities indicate MDCK-I cells.
However, the partial drug resistance of MDCK-I cells precludes their being the
parental cell. We speculate that the retroviral transfection per se, or the
subsequent selection for drug resistance, selected a subpopulation of MDCK-I
cells in the parental MDCK-II cell culture and that drug resistance in MDR1-MDCK
cells is thus a result of both MDR1 expression and a second, previously
unrecognized, component, likely the high level of GlcCer synthesis in these
cells.
PMID- 10692421
TI - Functional heterogeneity of small ubiquitin-related protein modifiers SUMO-1
versus SUMO-2/3.
AB - Post-translational modification marked by the covalent attachment of the
ubiquitin-like protein SUMO-1/SMT3C has been implicated in a wide variety of
cellular processes. Recently, two cDNAs encoding proteins related to SUMO-1 have
been identified in human and mouse. The functions and regulation of these
proteins, known as SUMO-2/SMT3A and SUMO-3/SMT3B, remain largely uncharacterized.
We describe herein quantitative and qualitative distinctions between SUMO-1 and
SUMO-2/3 in vertebrate cells. Much of this was accomplished through the
application of an antibody that recognizes SUMO-2 and -3, but not SUMO-1. This
antibody detected multiple SUMO-2/3-modified proteins and revealed that,
together, SUMO-2 and -3 constitute a greater percentage of total cellular protein
modification than does SUMO-1. Intriguingly, we found that there was a large pool
of free, non-conjugated SUMO-2/3 and that the conjugation of SUMO-2/3 to high
molecular mass proteins was induced when the cells were subjected to protein
damaging stimuli such as acute temperature fluctuation. In addition, we
demonstrated that SUMO-2/3 conjugated poorly, if at all, to a major SUMO-1
substrate, the Ran GTPase-activating protein RanGAP1. Together, these results
support the concept of important distinctions between the SUMO-2/3 and SUMO-1
conjugation pathways and suggest a role for SUMO-2/3 in the cellular responses to
environmental stress.
PMID- 10692422
TI - Transcriptional activation of the cyclooxygenase-2 gene in endotoxin-treated RAW
264.7 macrophages.
AB - Cyclooxygenase-2 (COX-2), the enzyme primarily responsible for induced
prostaglandin synthesis, is an immediate early gene induced by endotoxin in
macrophages. We investigated the cis-acting elements of the COX-2 5'-flanking
sequence, the transcription factors and signaling pathways responsible for
transcriptional activation of the COX-2 gene in endotoxin-treated murine RAW
264.7 macrophages. Luciferase reporter constructs with alterations in presumptive
cis-acting transcriptional regulatory elements demonstrate that the cyclic AMP
response element and two nuclear factor interleukin-6 (CCAAT/enhancer-binding
protein (C/EBP)) sites of the COX-2 promoter are required for optimal endotoxin
dependent induction. In contrast, the E-box and NF-kappaB sites are not required
for endotoxin-dependent induction. Inhibition of endotoxin-induced NF-kappaB
activation by expression of an inhibitor-kappaB alpha mutant does not block
endotoxin-dependent COX-2 reporter activity. Overexpression of c-Jun, C/EBPbeta,
and C/EBPdelta enhances induction of the COX-2 reporter, while overexpression of
cyclic AMP-response element-binding protein or "dominant negative" C/EBPbeta
represses COX-2 induction. In addition, endotoxin rapidly and transiently elicits
c-Jun phosphorylation in RAW 264.7 macrophages. Cotransfection of the COX-2
reporter with dominant negative expression vectors shows that endotoxin-induced
COX-2 gene expression requires signaling through a Ras-independent pathway
involving the adapter protein ECSIT and the signaling kinases MEKK1 and JNK. In
contrast, endotoxin-induced COX-2 reporter activity is not blocked by
overexpression of dominant-negative forms of Raf-1, ERK1, or ERK2.
PMID- 10692423
TI - The catalytic subunit of phosphoinositide 3-kinase: requirements for
oncogenicity.
AB - The retroviral oncogene p3k (v-p3k) of avian sarcoma virus 16 (ASV16) codes for
the catalytic subunit of phosphoinositide (PI) 3-kinase, p110alpha. The v-P3k
protein is oncogenic in vivo and in vitro; its cellular counterpart, c-P3k, lacks
oncogenicity. Fusion of viral Gag sequences to the amino terminus of c-P3k
activates the transforming potential. Activation can also be achieved by the
addition of a myristylation signal to the amino terminus or of a farnesylation
signal to the carboxyl terminus of c-P3k. A mutated myristylation signal was
equally effective; it also caused a strong increase in the kinase activity of
P3k. Mutations that inactivate lipid kinase activity abolish oncogenicity. The
transforming activity of P3k is correlated with the ability to induce activating
phosphorylation in Akt. Point mutations and amino-terminal deletions recorded in
v-P3k were shown to be irrelevant to the activation of oncogenic potential.
Interactions of P3k with the regulatory subunit of PI 3-kinase, p85, or with Ras
are not required for transformation. These results support the conclusion that
the oncogenicity of P3k depends on constitutive lipid kinase activity. Akt is an
important and probably essential downstream component of the oncogenic signal
from P3k.
PMID- 10692424
TI - Alkyl-dihydroxyacetonephosphate synthase. Presence and role of flavin adenine
dinucleotide.
AB - Alkyl-dihydroxyacetonephosphate synthase is a peroxisomal enzyme involved in
ether lipid synthesis. It catalyzes the exchange of the acyl chain in acyl
dihydroxyacetonephosphate for a long chain fatty alcohol, yielding the first
ether linked intermediate, i.e. alkyl-dihydroxyacetonephosphate, in the pathway
of ether lipid biosynthesis. Although this reaction is not a net redox reaction,
the amino acid sequence of the enzyme suggested the presence of a flavin adenine
dinucleotide (FAD)-binding domain. In this study we show that alkyl
dihydroxyacetonephosphate synthase contains an essential FAD molecule as
cofactor, which is evidenced by fluorescence properties, UV-visible absorption
spectra and the observation that the enzyme activity is dependent on the presence
of this cofactor in a coupled in vitro transcription/translation assay.
Furthermore, we could demonstrate that the FAD cofactor directly participates in
catalysis. Upon incubation of the enzyme with the substrate palmitoyl
dihydroxyacetonephosphate, the flavin moiety is reduced, indicating that in this
initial step the substrate is oxidized. Stopped flow experiments show that the
reduction of the flavin moiety is a monophasic process yielding a oxygen stable,
reduced enzyme species. Upon addition of hexadecanol to the reduced enzyme
species, the flavin moiety is efficiently reoxidized. A hypothetical reaction
mechanism is proposed that is consistent with the data in this paper and with
previous studies.
PMID- 10692425
TI - Molecular determinants of pH sensitivity of the type IIa Na/P(i) cotransporter.
AB - Type II Na/P(i) cotransporters play key roles in epithelial P(i) transport and
thereby contribute to overall P(i) homeostasis. Renal proximal tubular brush
border membrane expresses the IIa isoform, whereas the IIb isoform is
preferentially expressed in small intestinal brush border membrane of mammals.
IIa and IIb proteins are predicted to contain eight transmembrane domains with
the N- and C-terminal tails facing the cytoplasm. They differ in their pH
dependences: the activity of IIa increases at higher pH, whereas the IIb shows no
or a slightly opposite pH dependence. To determine the structural domains
responsible for the difference in pH sensitivity, mouse IIa and IIb chimeras were
constructed, and their pH dependence was characterized. A region between the
fourth and fifth transmembrane domains was required for conferring pH sensitivity
to the IIa-mediated Na/P(i) cotransport. Sequence comparison (IIa versus IIb) of
the third extracellular loops revealed a stretch of three charged amino acids in
IIa (REK) replaced by uncharged residues in IIb (GNT). Introduction of the
uncharged GNT sequence (by REK) in IIa abolished its pH dependence, whereas
introduction of the charged REK stretch in IIb (by GNT) led to a pH dependence
similar to IIa. These findings suggest that charged residues within the third
extracellular loop are involved in the pH sensitivity of IIa Na/P(i)
cotransporter.
PMID- 10692426
TI - Selenoprotein P expression, purification, and immunochemical characterization.
AB - Most selenoproteins contain a single selenocysteine residue per polypeptide
chain, encoded by an in-frame UGA codon. Selenoprotein P is unique in that its
mRNA encodes 10-12 selenocysteine residues, depending on species. In addition to
the high number of selenocysteines, the protein is cysteine- and histidine-rich.
The function of selenoprotein P has remained elusive, in part due to the
inability to express the recombinant protein. This has been attributed to
presumed inefficient translation through the selenocysteine/stop codons. Herein,
we report for the first time the expression of recombinant rat selenoprotein P in
a transiently transfected human epithelial kidney cell line, as well as the
endogenously expressed protein from HepG2 and Chinese hamster ovary cells. The
majority of the expressed protein migrates with the predicted 57-kDa size of full
length glycosylated selenoprotein P. Based on the histidine-rich nature of
selenoprotein P, we have purified the recombinant and endogenously expressed
proteins using nickel-agarose affinity chromatography. We show that the
recombinant rat and endogenous human proteins react in Western blotting and
immunoprecipitation assays with commercial anti-histidine antibodies. The ability
to express, purify, and immunochemically detect the recombinant protein provides
a foundation for investigating the functions and efficiency of expression of this
intriguing protein.
PMID- 10692427
TI - Functional heterodimerization of prolactin and growth hormone receptors by ovine
placental lactogen.
AB - Although homo- or heterodimerization are common mechanisms for activation of
cytokine receptors, cross-talk between two distinct receptors in this superfamily
has been never shown. Here we show a physiologically relevant example indicating
that such an interaction does occurs, thus raising the hypothesis that
heterodimerization between distinct cytokine receptors may be a novel mechanism
contributing to the diversity of cytokine signaling. These findings were
documented using both surface plasmon resonance and gel filtration experiments
and show that ovine placental lactogen (PL) heterodimerizes the extracellular
domains (ECDs) of ruminant growth hormone receptor (GHR) and prolactin receptor
(PRLR). We also show that PL or PL analogues that exhibit little or no activity
in cells transfected with PRLRs and no activity in cells transfected with ovine
GHRs exhibit largely enhanced activity in cells cotransfected with both PRLRs and
GHRs. Furthermore, chimeric receptors consisting of cytosolic and transmembrane
part of ovine GHR or ovine PRLR and ECDs of human granulocyte-macrophage colony
stimulating factor receptor (GM-CSFR) alpha or beta were constructed. Upon
transfection into Chinese hamster ovary cells along with reporter luciferase gene
and stimulation by GM-CSF, a significant increase in luciferase activity occurred
when GM-CSFR-alpha-PRLR and GM-CSFR-beta-GHR or GM-CSFR-alpha-GHR and GM-CSRR
beta-PRLR were cotransfected. In conclusion, we show that ovine PL is capable of
functional heterodimerization of GHR and PRLR and that when their cytosolic
parts, coupled to the ECD of GM-CSF receptors, are heterodimerized by GM-CSF,
they are capable of transducing biological signal.
PMID- 10692428
TI - Kinetic and pharmacological properties of human brain Na(+)/H(+) exchanger
isoform 5 stably expressed in Chinese hamster ovary cells.
AB - The recently cloned Na(+)/H(+) exchanger isoform 5 (NHE5) is expressed
predominantly in brain, yet little is known about its functional properties. To
facilitate its characterization, a full-length cDNA encoding human NHE5 was
stably transfected into NHE-deficient Chinese hamster ovary AP-1 cells.
Pharmacological analyses revealed that H(+)(i)-activated (22)Na(+) influx
mediated by NHE5 was inhibited by several classes of drugs (amiloride compounds,
3-methylsulfonyl-4-piperidinobenzoyl guanidine methanesulfonate, cimetidine, and
harmaline) at half-maximal concentrations that were intermediate to those
determined for the high affinity NHE1 and the low affinity NHE3 isoforms, but
closer to the latter. Kinetic analyses showed that the extracellular Na(+)
dependence of NHE5 activity followed a simple hyperbolic relationship with an
apparent affinity constant (K(Na)) of 18.6 +/- 1.6 mM. By contrast to other NHE
isoforms, NHE5 also exhibited a first-order dependence on the intracellular H(+)
concentration, achieving half-maximal activation at pH 6.43 +/- 0.08.
Extracellular monovalent cations, such as H(+) and Li(+), but not K(+), acted as
effective competitive inhibitors of (22)Na(+) influx by NHE5. In addition, the
transport activity of NHE5 was highly dependent on cellular ATP levels. Overall,
these functional features distinguish NHE5 from other family members and closely
resemble those of an amiloride-resistant NHE isoform identified in hippocampal
neurons.
PMID- 10692429
TI - Dynamics of protein-tyrosine phosphatases in rat adipocytes.
AB - Protein-tyrosine phosphatases (PTPases) play a key role in maintaining the steady
state tyrosine phosphorylation of the insulin receptor (IR) and its substrate
proteins such as insulin receptor substrate 1 (IRS-1). However, the PTPase(s)
that inactivate IR and IRS-1 under physiological conditions remain unidentified.
Here, we analyze the subcellular distribution in rat adipocytes of several
PTPases thought to be involved in the counterregulation of insulin signaling. We
found that the transmembrane enzymes, protein-tyrosine phosphatase (PTP)-alpha
and leukocyte common antigen-related (LAR), were detected predominantly in the
plasma membrane and to a lesser extent in the heavy microsomes, a distribution
similar to that of insulin receptor. PTP-1B and IRS-1 were present in light
microsomes and cytosol, whereas SHPTP2/Syp was exclusively cytosolic. Insulin
induced a redistribution of PTP-alpha from the plasma membrane to the heavy
microsomes in a parallel fashion with the receptor. The distribution of PTP-1B in
the light microsomes from resting adipocytes was similar to that of IRS-1 as
determined by sucrose velocity gradient fractionation. Analysis of the catalytic
activity of partially purified rat adipocyte PTP-alpha and LAR and recombinant
PTP-1B showed that all three PTPases dephosphorylate IR. When a mix of IR/IRS-1
was used as a substrate, PTP-1B was particularly effective in dephosphorylating
IRS-1. Considering that IR and IRS-1 can be dephosphorylated in internal membrane
compartments from rat adipocytes (Kublaoui, B., Lee, J., and Pilch, P.F. (1995)
J. Biol. Chem. 270, 59-65) and that PTP-alpha and PTP-1B are the respective
PTPases in these fractions, we conclude that these PTPases are responsible for
the counterregulation of insulin signaling there, whereas both LAR and PTP-alpha
may act upon cell surface insulin receptors.
PMID- 10692430
TI - Reconstitution of virus-mediated expression of interferon alpha genes in human
fibroblast cells by ectopic interferon regulatory factor-7.
AB - Type I interferons constitute an important part of the innate immune response
against viral infection. Unlike the expression of interferon (IFN) B gene, the
expression of IFNA genes is restricted to the lymphoid cells. Both IFN regulatory
factor 3 and 7 (IRF-3 and IRF-7) were suggested to play positive roles in these
genes expression. However, their role in the differential expression of
individual subtypes of human IFNA genes is unknown. Using various IFNA reporter
constructs in transient transfection assay we found that overexpression of IRF-3
in virus infected 2FTGH cells selectively activated IFNA1 VRE, whereas IRF-7 was
able to activate IFNA1, A2, and A4. The binding of recombinant IRF-7 and IRF-3 to
these VREs correlated with their transcriptional activation. Nuclear proteins
from infected and uninfected IRF-7 expressing 2FTGH cells formed multiple DNA
protein complexes with IFNA1 VRE, in which two unique DNA-protein complexes
containing IRF-7 were detected. In 2FTGH cells, virus stimulated expression of
IFNB gene but none of the IFNA genes. Reconstitution of IRF-7 synthesis in these
cells resulted, upon virus infection, in the activation of seven endogenous IFNA
genes in which IFNA1 predominated. These studies suggest that IRF-7 is a critical
determinant for the induction of IFNA genes in infected cells.
PMID- 10692431
TI - The organization of aggrecan in human articular cartilage. Evidence for age
related changes in the rate of aggregation of newly synthesized molecules.
AB - The effect of age on the incorporation of newly synthesized aggrecan into the
extracellular matrix of human articular cartilage was investigated. This property
was measured in a pulse-chase explant culture system by determining the
distribution of radiolabeled molecules ([(35)S]sulfate-labeled) between a
nondissociating extract (phosphate-buffered saline), which extracts mainly
nonaggregated macromolecules, and a dissociating extract (4 M GnHCl) containing
mainly aggrecan that was complexed in situ with hyaluronan. The rate of
incorporation of aggrecan into aggregates was much slower in mature cartilage
than in tissue obtained from younger individuals. Furthermore, autoradiography
showed that in mature cartilage, newly synthesized aggrecan is not transported
from the pericellular environment within the first 18 h of chase culture, whereas
in immature cartilage, it moves into the intercellular space during the same
period, i.e. aggrecan is processed in the extracellular space very differently in
young and adult articular cartilage. Experiments were also performed to show that
the interaction of link protein with newly synthesized aggrecan depends on the
maturity of the G(1) domain of aggrecan. This investigation has shown that the
extracellular aggregation of aggrecan in adult human articular cartilage involves
a number of intermediate structures. These have not been identified in the very
young cartilage obtained from laboratory animals or in porcine and bovine
articular cartilage obtained from the abattoir.
PMID- 10692432
TI - The C terminus of SNAP25 is essential for Ca(2+)-dependent binding of
synaptotagmin to SNARE complexes.
AB - The plasma membrane soluble N-ethylmaleimide-sensitive factor attachment protein
receptor (SNARE) proteins syntaxin and synaptosome-associated protein of 25 kDa
(SNAP25) and the vesicle SNARE protein vesicle-associated membrane protein (VAMP)
are essential for a late Ca(2+)-dependent step in regulated exocytosis, but their
precise roles and regulation by Ca(2+) are poorly understood. Botulinum
neurotoxin (BoNT) E, a protease that cleaves SNAP25 at Arg(180)-Ile(181),
completely inhibits this late step in PC12 cell membranes, whereas BoNT A, which
cleaves SNAP25 at Gln(197)-Arg(198), is only partially inhibitory. The difference
in toxin effectiveness was found to result from a reversal of BoNT A but not BoNT
E inhibition by elevated Ca(2+) concentrations. BoNT A treatment essentially
increased the Ca(2+) concentration required to activate exocytosis, which
suggested a role for the C terminus of SNAP25 in the Ca(2+) regulation of
exocytosis. Synaptotagmin, a proposed Ca(2+) sensor for exocytosis, was found to
bind SNAP25 in a Ca(2+)-stimulated manner. Ca(2+)-dependent binding was abolished
by BoNT E treatment, whereas BoNT A treatment increased the Ca(2+) concentration
required for binding. The C terminus of SNAP25 was also essential for Ca(2+)
dependent synaptotagmin binding to SNAP25. syntaxin and SNAP25.syntaxin.VAMP
SNARE complexes. These results clarify classical observations on the Ca(2+)
reversal of BoNT A inhibition of neurosecretion, and they suggest that an
essential role for the C terminus of SNAP25 in regulated exocytosis is to mediate
Ca(2+)-dependent interactions between synaptotagmin and SNARE protein complexes.
PMID- 10692433
TI - Cdk2-dependent and -independent pathways in E2F-mediated S phase induction.
AB - The transcription factor E2F plays an important role in G(1) to S phase
transition in the higher eukaryotic cell cycle. Although a number of E2F
inducible genes have been identified, the biochemical cascades from E2F to the S
phase entry remain to be investigated. In this study, we generated stably
transfected mouse NIH3T3 cells that express exogenous human E2F-1 under the
control of a heavy metal-inducible metallothionein promoter and analyzed the
molecular mechanism of the E2F-1-mediated initiation of chromosomal DNA
replication. Ectopic E2F-1 expression in cells arrested in G(0)/G(1) by serum
deprivation enabled them to progress through G(1) and to enter S phase. During
the G(1) progression, mouse cyclin E, but little of cyclin D1, was induced to
express, which subsequently activated Cdk2. Experiments using the Cdk inhibitory
proteins p27, p18, and p19 proved that the activity of Cdk2, but not of Cdk4, was
required for S phase entry mediated by E2F-1. Minichromosome maintenance proteins
(MCM) 4 and 7, the components of the DNA-replication initiation complex (RC),
were constitutively expressed during the cell cycle, although the MCM genes are
well known E2F-inducible genes. However, tight association of these two proteins
with chromatin depended upon ectopic E2F-1 expression. In contrast, the Cdc45
protein, another RC component, which turned out to be a transcriptional target of
E2Fs, was induced to express and subsequently bound to chromatin in response to
E2F-1. Experiments utilizing a chemical Cdk-specific inhibitor, butyrolactone I,
revealed that Cdk2 activity was required only for chromatin binding of the Cdc45
proteins, and not for the expression of Cdc45 or chromatin binding of MCM4 and
7. These results indicate that at least two separate pathways function downstream
of E2F to initiate S phase; one depends upon the activity of Cdk2 and the other
does not.
PMID- 10692434
TI - Dityrosine formation outcompetes tyrosine nitration at low steady-state
concentrations of peroxynitrite. Implications for tyrosine modification by nitric
oxide/superoxide in vivo.
AB - Formation of peroxynitrite from NO and O-(*2) is considered an important trigger
for cellular tyrosine nitration under pathophysiological conditions. However,
this view has been questioned by a recent report indicating that NO and O-(*2)
generated simultaneously from (Z)-1-(N-[3-aminopropyl]-N-[4-(3
aminopropylammonio)butyl]-amino) diazen-1-ium-1,2-diolate] (SPER/NO) and
hypoxanthine/xanthine oxidase, respectively, exhibit much lower nitrating
efficiency than authentic peroxynitrite (Pfeiffer, S. and Mayer, B. (1998) J.
Biol. Chem. 273, 27280-27285). The present study extends those earlier findings
to several alternative NO/O-(*2)-generating systems and provides evidence that
the apparent lack of tyrosine nitration by NO/O-(*2) is due to a pronounced
decrease of nitration efficiency at low steady-state concentrations of authentic
peroxynitrite. The decrease in the yields of 3-nitrotyrosine was accompanied by
an increase in the recovery of dityrosine, showing that dimerization of tyrosine
radicals outcompetes the nitration reaction at low peroxynitrite concentrations.
The observed inverse dependence on peroxynitrite concentration of dityrosine
formation and tyrosine nitration is predicted by a kinetic model assuming that
radical formation by peroxynitrous acid homolysis results in the generation of
tyrosyl radicals that either dimerize to yield dityrosine or combine with
(*)NO(2) radical to form 3-nitrotyrosine. The present results demonstrate that
very high fluxes (>2 microM/s) of NO/O-(*2) are required to render peroxynitrite
an efficient trigger of tyrosine nitration and that dityrosine is a major product
of tyrosine modification caused by low steady-state concentrations of
peroxynitrite.
PMID- 10692435
TI - DNA methyltransferase inhibition induces the transcription of the tumor
suppressor p21(WAF1/CIP1/sdi1).
AB - Previous lines of evidence have shown that inhibition of DNA methyltransferase
(MeTase) can arrest tumor cell growth; however, the mechanisms involved were not
clear. In this manuscript we show that out of 16 known tumor suppressors and cell
cycle regulators, the cyclin-dependent kinase inhibitor p21 is the only tumor
suppressor induced in the human lung cancer cell line, A549, following inhibition
of DNA MeTase by a novel DNA MeTase antagonist or antisense oligonucleotides. The
rapid induction of p21 expression points to a mechanism that does not involve
demethylation of p21 promoter. Consistent with this hypothesis, we show that part
of the CpG island upstream of the endogenous p21 gene is unmethylated and that
the expression of unmethylated p21 promoter luciferase reporter constructs is
induced following inhibition of DNA MeTase. These results are consistent with the
hypothesis that the level of DNA MeTase in a cell can control the expression of a
nodal tumor suppressor by a mechanism that does not involve DNA methylation.
PMID- 10692436
TI - Ca(2+)-dependent and Ca(2+)-independent calmodulin binding sites in erythrocyte
protein 4.1. Implications for regulation of protein 4.1 interactions with
transmembrane proteins.
AB - In vitro protein binding assays identified two distinct calmodulin (CaM) binding
sites within the NH(2)-terminal 30-kDa domain of erythrocyte protein 4.1 (4.1R):
a Ca(2+)-independent binding site (A(264)KKLWKVCVEHHTFFRL) and a Ca(2+)-dependent
binding site (A(181)KKLSMYGVDLHKAKDL). Synthetic peptides corresponding to these
sequences bound CaM in vitro; conversely, deletion of these peptides from a 30
kDa construct reduced binding to CaM. Thus, 4.1R is a unique CaM-binding protein
in that it has distinct Ca(2+)-dependent and Ca(2+)-independent high affinity CaM
binding sites. CaM bound to 4.1R at a stoichiometry of 1:1 both in the presence
and absence of Ca(2+), implying that one CaM molecule binds to two distinct sites
in the same molecule of 4.1R. Interactions of 4.1R with membrane proteins such as
band 3 is regulated by Ca(2+) and CaM. While the intrinsic affinity of the 30-kDa
domain for the cytoplasmic tail of erythrocyte membrane band 3 was not altered by
elimination of one or both CaM binding sites, the ability of Ca(2+)/CaM to down
regulate 4. 1R-band 3 interaction was abrogated by such deletions. Thus,
regulation of protein 4.1 binding to membrane proteins by Ca(2+) and CaM requires
binding of CaM to both Ca(2+)-independent and Ca(2+)-dependent sites in protein
4.1.
PMID- 10692437
TI - NBP-45, a novel nucleosomal binding protein with a tissue-specific and
developmentally regulated expression.
AB - Here we characterize a novel murine nuclear protein, which we named NBP-45, that
is related to the ubiquitous nuclear proteins HMG-14/-17, binds specifically to
nucleosome core particles, and can function as a transcriptional activator. NBP
45 mRNA is expressed at low levels and in variable amounts in all mouse tissues
tested but is especially abundant in RNA extracted from 7-day-old mouse embryos,
suggesting that it functions in early embryonic development. NBP-45 is composed
of 406 amino acids and is encoded by a single size transcript. The region
spanning the N-terminal 85 amino acids contains three segments that are highly
homologous to functionally important domains in the HMG-14/-17 protein family:
the nuclear localization signal, the nucleosome binding domain, and the chromatin
unfolding domain. The protein region spanning the C-terminal 321 amino acids has
a 42% content of negatively charged residues. The first 23 amino acids contain a
region necessary for nuclear entry of the protein, the region spanning residues
12-40 is the main nucleosomal binding domain of the protein, and the negatively
charged, C-terminal domain is necessary for transcription activation. The
functional domains of NBP-45 are indicative of a nuclear protein that binds to
nucleosomes, thereby creating a chromatin region of high local negative charge.
Our studies establish the nucleosomal binding domain as a protein motif that is
present in other than just the ubiquitous HMG-14/-17 proteins. We suggest that
the nucleosomal binding domain motif is a protein module that facilitates binding
to nucleosomes in chromatin.
PMID- 10692438
TI - Importance of the hinge region between alpha-helix F and the main part of
serpins, based upon identification of the epitope of plasminogen activator
inhibitor type 1 neutralizing antibodies.
AB - The serpin plasminogen activator inhibitor type 1 (PAI-1) is an important protein
in the regulation of fibrinolysis and inhibits its target proteinases through
formation of a covalent complex. In the present study, we have identified the
epitope of two PAI-1 neutralizing monoclonal antibodies (MA-33H1F7 and MA
55F4C12). Based upon differential cross-reactivity data of these monoclonals with
PAI-1 from different species and on a sequence alignment between these PAI-1s,
combined with the three-dimensional structure, we predicted that the residues
Glu(128)-Val(129)-Glu(130)-Arg(131) and Lys(154) (at the hinge region between
alpha-helix F and the main part of the PAI-1-molecule) might form the major site
of interaction. Therefore a variety of alanine mutants were generated and
evaluated for their affinity toward both monoclonal antibodies. The affinity
constants of MA-55F4C12 and MA-33H1F7 for PAI-1 were 2.7 +/- 1.6 x 10(9) M(-1)
and 5.4 +/- 1.7 x 10(9) M(-1), respectively, but decreased between 13- and 270
fold upon mutation of Lys(154) to Ala(154) or Glu(128)-Val(129)-Glu(130)-Arg(131)
to Ala-Ala-Ala-Ala. The combined mutations (PAI-1-EVER/K), however, resulted in
an absence of binding to either of the antibodies. Both antibodies bound to PAI-1
wt/t-PA complexes with a similar affinity as to PAI-1-wt (K(A) = 4-5 x 10(9) M(
1)). The epitope localization reveals the molecular basis for the neutralizing
properties of both monoclonal antibodies. In addition, it provides new insights
into the validity of various models that have been proposed for the
serpin/proteinase complex, excluding full insertion of the reactive-site loop.
PMID- 10692439
TI - Cardiovascular basic helix loop helix factor 1, a novel transcriptional repressor
expressed preferentially in the developing and adult cardiovascular system.
AB - We have cloned a cardiovascular-restricted basic helix-loop-helix factor that
interacts with arylhydrocarbon receptor nuclear translocator (ARNT) in a yeast
two-hybrid screen. Cardiovascular helix-loop-helix factor 1 (CHF1) is distantly
related to the hairy family of transcriptional repressors. We analyzed its
expression pattern during mouse embryo development. At day 8.5, the expression of
CHF1 is first detected in the primitive ventricle of the primordial heart tube
and persists throughout gestation. In rat hearts, this expression is down
regulated after birth, concurrent with terminal differentiation of
cardiomyocytes. In the developing vasculature, CHF1 first appears in the dorsal
aorta at day 9.0, which precedes the reported expression of smooth muscle cell
markers, and persists into adulthood. In an in vitro system of smooth muscle cell
differentiation, CHF1 mRNA was barely detectable in undifferentiated cells but
was induced highly in differentiated smooth muscle cells. To determine whether
CHF1 might affect the function of ARNT, we performed transfection studies. Co
transfection of CHF1 inhibited ARNT/EPAS1-dependent transcription by 85%, and
this inhibition is dose-dependent. In electrophoretic mobility studies, CHF1
inhibited the binding of the ARNT/EPAS1 heterodimer to its target site. Our data
suggest that CHF1 functions as a transcriptional repressor and may play an
important role in cardiovascular development.
PMID- 10692440
TI - G protein modulation of N-type calcium channels is facilitated by physical
interactions between syntaxin 1A and Gbetagamma.
AB - The direct modulation of N-type calcium channels by G protein betagamma subunits
is considered a key factor in the regulation of neurotransmission. Some of the
molecular determinants that govern the binding interaction of N-type channels and
Gbetagamma have recently been identified (see, i.e., Zamponi, G. W., Bourinet,
E., Nelson, D., Nargeot, J., and Snutch, T. P. (1997) Nature 385, 442-446);
however, little is known about cellular mechanisms that modulate this
interaction. Here we report that a protein of the presynaptic vesicle release
complex, syntaxin 1A, mediates a crucial role in the tonic inhibition of N-type
channels by Gbetagamma. When syntaxin 1A was coexpressed with (N-type) alpha(1B)
+ alpha(2)-delta + beta(1b) channels in tsA-201 cells, the channels underwent a
18 mV negative shift in half-inactivation potential, as well as a pronounced
tonic G protein inhibition as assessed by its reversal by strong membrane
depolarizations. This tonic inhibition was dramatically attenuated following
incubation with botulinum toxin C, indicating that syntaxin 1A expression was
indeed responsible for the enhanced G protein modulation. However, when G protein
betagamma subunits were concomitantly coexpressed, the toxin became ineffective
in removing G protein inhibition, suggesting that syntaxin 1A optimizes, rather
than being required for G protein modulation of N-type channels. We also
demonstrate that Gbetagamma physically binds to syntaxin 1A, and that syntaxin 1A
can simultaneously interact with Gbetagamma and the synprint motif of the N-type
channel II-III linker. Taken together, our experiments suggest a mechanism by
which syntaxin 1A mediates a colocalization of G protein betagamma subunits and N
type calcium channels, thus resulting in more effective G protein coupling to,
and regulation of, the channel. Thus, the interactions between syntaxin, G
proteins, and N-type calcium channels are part of the structural specialization
of the presynaptic terminal.
PMID- 10692441
TI - An isoform of kalirin, a brain-specific GDP/GTP exchange factor, is enriched in
the postsynaptic density fraction.
AB - Communication between membranes and the actin cytoskeleton is an important aspect
of neuronal function. Regulators of actin cytoskeletal dynamics include the Rho
like small GTP-binding proteins and their exchange factors. Kalirin is a brain
specific protein, first identified through its interaction with peptidylglycine
alpha-amidating monooxygenase. In this study, we cloned rat Kalirin-7, a 7
kilobase mRNA form of Kalirin. Kalirin-7 contains nine spectrin-like repeats, a
Dbl homology domain, and a pleckstrin homology domain. We found that the majority
of Kalirin-7 protein is associated with synaptosomal membranes, but a fraction is
cytosolic. We also detected higher molecular weight Kalirin proteins. In rat
cerebral cortex, Kalirin-7 is highly enriched in the postsynaptic density
fraction. In primary cultures of neurons, Kalirin-7 is detected in spine-like
structures, while other forms of Kalirin are visualized in the cell soma and
throughout the neurites. Kalirin-7 and its Dbl homology-pleckstrin homology
domain induce formation of lamellipodia and membrane ruffling, when transiently
expressed in fibroblasts, indicative of Rac1 activation. Using Rac1, the Dbl
homology-pleckstrin homology domain catalyzed the in vitro exchange of bound GDP
with GTP. Kalirin-7 is the first guanine-nucleotide exchange factor identified in
the postsynaptic density, where it is positioned optimally to regulate signal
transduction pathways connecting membrane proteins and the actin cytoskeleton.
PMID- 10692442
TI - Chat, a Cas/HEF1-associated adaptor protein that integrates multiple signaling
pathways.
AB - Cas (Crk-associated substrate) and HEF1 (human enhancer of filamentation) are
related adaptor proteins that function in integrin-mediated cell adhesion and
antigen receptor signaling pathways. We report here a molecular cloning of Chat
(Cas/HEF1-associated signal transducer) that associates with Cas and HEF1. Chat
is a 78-kDa signaling molecule with an N-terminal SH2 domain and is expressed in
a wide range of tissues. In hematopoietic cells, a 115-kDa isoform of Chat (Chat
H) was specifically expressed. Chat is associated with Cas in brain, and Chat-H
is associated with HEF1 in splenocytes. Deletion analyses revealed that Chat and
Cas are associated with each other by their C-terminal domains. Treatment of PC12
cells with epidermal growth factor or nerve growth factor increased the
phosphorylation level of Chat. This increase was suppressed by an inhibitor of
mitogen-activated protein (MAP) kinase kinase, PD98059, suggesting the
phosphorylation of Chat by MAP kinase. In Chat-overexpressed COS7 cells, the
activity of c-Jun N-terminal kinase was up-regulated. After the epidermal growth
factor stimulation, Chat and Cas were colocalized with actin filaments at
ruffling membranes. These findings suggest that Chat transduces signals of
tyrosine kinases and MAP kinase to Cas signaling pathway.
PMID- 10692443
TI - Differential roles of the Src homology 2 domains of phospholipase C-gamma1 (PLC
gamma1) in platelet-derived growth factor-induced activation of PLC-gamma1 in
intact cells.
AB - Upon stimulation of cells with platelet-derived growth factor (PDGF),
phospholipase C-gamma1 (PLC-gamma1) binds to the tyrosine-phosphorylated PDGF
receptor through one or both of its Src homology 2 (SH2) domains, is
phosphorylated by the receptor kinase, and is thereby activated to hydrolyze
phosphatidylinositol 4, 5-bisphosphate. Association of PLC-gamma1 with the
insoluble subcellular fraction is also enhanced in PDGF-stimulated cells. The
individual roles of the two SH2 domains of PLC-gamma1 in mediating the
interaction between the enzyme and the PDGF receptor have now been investigated
by functionally disabling each domain. A critical Arg residue in each SH2 domain
was mutated to Ala. Both wild-type and mutant PLC-gamma1 proteins were
transiently expressed in a PLC-gamma1-deficient fibroblast cell line, and these
transfected cells were stimulated with PDGF. The mutant protein in which the COOH
terminal SH2 domain was disabled bound to the PDGF receptor. Accordingly, it was
phosphorylated by the receptor, catalyzed the production of inositol phosphates,
and mobilized intracellular calcium to extents similar to (but slightly less
than) those observed with the wild-type enzyme. In contrast, the mutant in which
the NH(2)-terminal SH2 domain was impaired did not bind to the PDGF receptor and
consequently was neither phosphorylated nor activated. These results suggest that
the NH(2)-terminal SH2 domain, but not the COOH-terminal SH2 domain, of PLC
gamma1 is required for PDGF-induced activation of PLC-gamma1. Functional
impairment of the SH2 domains did not affect the PDGF-induced redistribution of
PLC-gamma1, suggesting that recruitment of PLC-gamma1 to the particulate fraction
does not involve the SH2 domains.
PMID- 10692444
TI - Calcineurin is downstream of the inositol 1,4,5-trisphosphate receptor in the
apoptotic and cell growth pathways.
AB - The inositol 1,4,5-trisphosphate receptor (IP(3)R) is a calcium (Ca(2+)) release
channel found on the endoplasmic reticulum of virtually all types of cells. Human
T lymphocytes (Jurkat) that are made deficient in IP(3)R do not generate Ca(2+)
signals in response to T cell receptor stimulation, fail to translocate the
nuclear factor for activated T cells to the nucleus, and are remarkably resistant
to induction of apoptosis with CD95 (Fas), dexamethasone, gamma irradiation, and
T cell receptor stimulation using anti-CD3 antibody. Expression of constitutively
active calcineurin A in IP(3)R-deficient T cells restored nuclear factor for
activated T cells translocation to the nucleus and dephosphorylation of Bad and
rendered the cells sensitive to apoptotic inducers. Induction of apoptosis
required both active calcineurin A (DeltaCnA) and activation-dependent
colocalization of CnA with its substrate. Thus, the Ca(2+)-dependent phosphatase
calcineurin (CnA) is downstream of the IP(3)R in both the cell growth and
apoptotic signaling pathways.
PMID- 10692445
TI - NFkappaB mediates apoptosis through transcriptional activation of Fas (CD95) in
adenoviral hepatitis.
AB - NFkappaB is an essential survival factor in several physiological conditions such
as embryonal liver development and liver regeneration. However, NFkappaB is also
a main mediator of the cellular response to a variety of extracellular stress
stimuli, and it has been shown that some viral-induced host cell apoptosis
appears to be dependent on NFkappaB activation. The activation of NFkappaB upon
viral infection may be a rapid way of initiating an innate immune response
against the viral particles. We have assessed the role of NFkB during the early
phase of adenoviral hepatitis in a nude mouse model using an adenoviral vector
expressing a mutant form of IkappaBalpha. Administration of a LacZ-expressing
adenoviral vector induces NFkB DNA and correlates with the up-regulation of Fas
(CD95) mRNA, but not FasL (CD95L) mRNA, during the early phase of adenoviral
hepatitis. The rapid increase in NFkappaB DNA binding after adenoviral infection
of the liver could be very effectively inhibited by IkappaBalpha. Compared with
the LacZ control virus, the IkappaBalpha-expressing adenoviral vector inhibits
the increase of Fas (CD95) mRNA expression, in particular in the very early phase
of the hepatitis. Reporter gene experiments in hepatoma cell lines with a Fas
promoter-luciferase construct indicated that the repression of Fas (CD95) mRNA by
IkappaBalpha was transcriptionally mediated. The functional relevance of the
NFkappaB-dependent increase in Fas (CD95) transcription was assessed by caspase 3
assays and terminal dUTP nick-end labeling tests. Compared with the control,
IkappaBalpha adenoviral infection resulted in reduced caspase 3 activity during
the early phase of viral hepatitis and in a prevention of liver cell apoptosis 24
h after adenoviral administration. Therefore our study demonstrates a new pro
apoptotic function of NFkappaB in Fas (CD95)-mediated apoptosis of hepatocytes.
Interestingly, NFkappaB mediates liver cell apoptosis upon viral infection even
in a phase where tumor necrosis factor-alpha is already induced, as shown by the
time curves of tumor necrosis factor-alpha serum levels. Therefore, the pro- or
anti-apoptotic role of NFkappaB appears to be more determined by the nature of
the death stimulus than by the origin of the tissue.
PMID- 10692446
TI - A novel phosphatidylinositol-phospholipase C of Trypanosoma cruzi that is lipid
modified and activated during trypomastigote to amastigote differentiation.
AB - The phosphoinositide (PI)-specific phospholipase C gene (TcPI-PLC) of the
protozoan parasite Trypanosoma cruzi was cloned, sequenced, expressed in
Escherichia coli, and the protein product (TcPI-PLC) was shown to have enzymatic
characteristics similar to those of mammalian delta-type PI-PLCs. The TcPI-PLC
gene is expressed at high levels in the epimastigote and amastigote stages of the
parasite, and its expression is induced during the differentiation of
trypomastigotes into amastigotes, where TcPI-PLC associates with the plasma
membrane and increases its catalytic activity. In contrast to other PI-PLCs
described so far, the deduced amino acid sequence of TcPI-PLC revealed some
unique features such as an N-myristoylation consensus sequence at its amino
terminal end, lack of an apparent pleckstrin homology domain and a highly charged
linker region between the catalytic X and Y domains. TcPI-PLC is lipid modified
in vivo, as demonstrated by metabolic labeling with [(3)H]myristate and
[(3)H]palmitate and fatty acid analysis of the immunoprecipitated protein, and
may constitute the first example of a new group of PI-PLCs.
PMID- 10692447
TI - Cholesterol oxidation switches the internalization pathway of endothelin receptor
type A from caveolae to clathrin-coated pits in Chinese hamster ovary cells.
AB - We investigated the mechanism of endothelin receptor type A (ETA) internalization
in Chinese hamster ovary cells using two assays; flow cytometric quantification
of cell surface myc-ETA and in situ localization of Cy5-labeled ET-1. In both
assays, agonist-dependent internalization of myc-ETA was inhibited by nystatin
and filipin, both of which disrupt internalization via caveolae, whereas it was
barely affected by chlorpromazine and hypertonic sucrose, both of which disrupt
internalization via clathrin-coated pits. In addition to myc-ETA, ET-1 caused
intracellular translocation of caveolin-1 and this translocation was also blocked
by nystatin but not by chlorpromazine. These results strongly argue that ETA is
internalized via caveolae but not clathrin-coated pits. Treatment of the cells
with cholesterol oxidase reduced cellular cholesterol and caused intracellular
translocation of caveolin-1 but did not affect cell surface localization of myc
ETA. In cholesterol oxidase-treated cells, however, both chlorpromazine and
hypertonic sucrose effectively blocked ET-1-induced myc-ETA internalization and
nystatin was less effective than in untreated cells. Accordingly, expression of a
dominant negative form of beta-arrestin blocked myc-ETA internalization in
cholesterol oxidase-treated cells but not in untreated cells. These results
suggest that, in Chinese hamster ovary cells, 1) agonist-occupied ETA can be
internalized either via caveolae or clathrin-coated pits; 2) of the two, the
former is the default pathway; and 3) the oxidative state of cell surface
cholesterol is one of the factors involved in the pathway selection.
PMID- 10692448
TI - The human 20-kDa 5'-(CGG)(n)-3'-binding protein is targeted to the nucleus and
affects the activity of the FMR1 promoter.
AB - Previous reports have described the human DNA CGG repeat-binding protein (CGGBP1
or p20), which binds specifically to nonmethylated, but not to methylated, 5'
(CGG)(n)-3' repeats in the promoter of the fragile X mental retardation 1 (FMR1)
gene. The results of transfection experiments into human HeLa cells using a p20
green fluorescent protein fusion construct indicate that the p20 protein is
targeted to the nucleus. By deletion analyses, a nuclear localization signal has
been found between amino acids 80 and 84. Deletions between amino acids 69 and 71
and between 95 and 167 interfere with 5'-(CGG)(n)-3' binding. The results of
electrophoretic mobility shift assays using DNA with 5'-(CGG)(n)-3' repeats of
different lengths render it likely that oligomers of the p20 protein bind to the
repeat. In cotransfection experiments, the activity of the FMR1 promoter is
reduced by the presence of p20. Upon transfection of the p20 cDNA construct into
HeLa cells, transcription of the endogenous FMR1 gene is decreased. The green
fluorescent protein-p20 fusion protein associates preferentially with the
telomeres of the short arms of human chromosomes 13, 14, 15, 21, and 22. Their
telomeres carry the genes for the 28 S rRNA, which contain 5'-(CGG)(n)-3'
repeats. The translated region of the p20 gene from three healthy, five fragile X
syndrome, and five premutation-carrying individuals has been sequenced, but
mutations have not been detected.
PMID- 10692449
TI - Cloning and functional characterization of novel large conductance calcium
activated potassium channel beta subunits, hKCNMB3 and hKCNMB4.
AB - We present the cloning and characterization of two novel calcium-activated
potassium channel beta subunits, hKCNMB3 and hKCNMB4, that are enriched in the
testis and brain, respectively. We compare and contrast the steady state and
kinetic properties of these beta subunits with the previously cloned mouse beta1
(mKCNMB1) and the human beta2 subunit (hKCNMB2). Once inactivation is removed, we
find that hKCNMB2 has properties similar to mKCNMB1. hKCNMB2 slows Hslo1 channel
gating and shifts the current-voltage relationship to more negative potentials.
hKCNMB3 and hKCNMB4 have distinct effects on slo currents not observed with
mKCNMB1 and hKCNMB2. Although we found that hKCNMB3 does interact with Hslo
channels, its effects on Hslo1 channel properties were slight, increasing Hslo1
activation rates. In contrast, hKCNMB4 slows Hslo1 gating kinetics, and modulates
the apparent calcium sensitivity of Hslo1. We found that the different effects of
the beta subunits on some Hslo1 channel properties are calcium-dependent. mKCNMB1
and hKCNMB2 slow activation at 1 microM but not at 10 microM free calcium
concentrations. hKCNMB4 decreases Hslo1 channel openings at low calcium
concentrations but increases channel openings at high calcium concentrations.
These results suggest that beta subunits in diverse tissue types fine-tune slo
channel properties to the needs of a particular cell.
PMID- 10692450
TI - Thrombin inhibits tumor cell growth in association with up-regulation of
p21(waf/cip1) and caspases via a p53-independent, STAT-1-dependent pathway.
AB - Thrombin, a multifunctional protein, has been found to be involved in cellular
mitogenesis, tumor growth, and metastasis, in addition to its well known effects
on the initiation of platelet aggregation and secretion and the conversion of
fibrinogen to fibrin to form blood clots. These properties of thrombin rely on
its action as a serine protease, which cleaves the N-terminal region of a 7
transmembrane G protein receptor (protease-activated receptor, PAR-1), thus
exposing a tethered end hexapeptide sequence capable of activating its receptor.
Little is known about its effect on genes that regulate the cell cycle. This
study was undertaken to investigate the possible mechanisms by which thrombin
regulates tumor cell growth in several tumor cell lines: human CHRF
megakaryocyte, DU145 prostate, MDAMB231 and MCF7 breast, U3A fibrosarcoma, and 2
murine fibroblast cell lines, MEFp53(-/-) and CD STAT(-/-). We have found that
thrombin under the conditions of culture employed inhibits cell growth by both up
regulation of p21(waf/cip1) and induction of caspases via its PAR-1 receptor. The
increased expression of p21(waf/cip1) by thrombin was p53 independent, STAT1
dependent, and protein synthesis independent. This was associated with tyrosine
phosphorylation of JAK2 and STAT1, and nuclear translocation of STAT1. Induction
of apoptosis is also PAR-1-specific, STAT1-dependent, and associated with up
regulation of caspases 1, 2, and 3. Our study establishes, for the first time, a
link between PAR-1 receptor activation with the STAT signal pathway, which leads
to cell cycle control and apoptosis. This observation broadens our understanding
of the mechanism of PAR-1 activation and its effect on cell growth, and could
possibly lead to therapeutic approaches for the treatment of cancer.
PMID- 10692451
TI - Determination of the disulfide bond arrangement of Newcastle disease virus
hemagglutinin neuraminidase. Correlation with a beta-sheet propeller structural
fold predicted for paramyxoviridae attachment proteins.
AB - Disulfide bonds stabilize the structure and functions of the hemagglutinin
neuraminidase attachment glycoprotein (HN) of Newcastle disease virus. Until this
study, the disulfide linkages of this HN and structurally similar attachment
proteins of other members of the paramyxoviridae family were undefined. To define
these linkages, disulfide-linked peptides were produced by peptic digestion of
purified HN ectodomains of the Queensland strain of Newcastle disease virus,
isolated by reverse phase high performance liquid chromatography, and analyzed by
mass spectrometry. Analysis of peptides containing a single disulfide bond
revealed Cys(531)-Cys(542) and Cys(172)-Cys(196) linkages and that HN ectodomains
dimerize via Cys(123). Another peptide, with a chain containing Cys(186) linked
to a chain containing Cys(238), Cys(247), and Cys(251), was cleaved at Met(249)
with cyanogen bromide. Subsequent tandem mass spectrometry established Cys(186)
Cys(247) and Cys(238)-Cys(251) linkages. A glycopeptide with a chain containing
Cys(344) linked to a chain containing Cys(455), Cys(461), and Cys(465) was
treated sequentially with peptide-N-glycosidase F and trypsin. Further treatment
of this peptide by one round of manual Edman degradation or tandem mass
spectrometry established Cys(344)-Cys(461) and Cys(455)-Cys(465) linkages. These
data, establishing the disulfide linkages of all thirteen cysteines of this
protein, are consistent with published predictions that the paramyxoviridae HN
forms a beta-propeller structural fold.
PMID- 10692452
TI - Epsin binds to clathrin by associating directly with the clathrin-terminal
domain. Evidence for cooperative binding through two discrete sites.
AB - Epsin is a recently identified protein that appears to play an important role in
clathrin-mediated endocytosis. The central region of epsin 1, the so-called DPW
domain, binds to the heterotetrameric AP-2 adaptor complex by associating
directly with the globular appendage of the alpha subunit. We have found that
this central portion of epsin 1 also associates with clathrin. The interaction
with clathrin is direct and not mediated by epsin-bound AP-2. Alanine scanning
mutagenesis shows that clathrin binding depends on the sequence (257)LMDLADV
located within the epsin 1 DPW domain. This sequence, related to the known
clathrin-binding sequences in the adaptor beta subunits, amphiphysin, and beta
arrestin, facilitates the association of epsin 1 with the terminal domain of the
clathrin heavy chain. Unexpectedly, inhibiting the binding of AP-2 to the GST
epsin DPW fusion protein by progressively deleting DPW triplets but leaving the
LMDLADV sequence intact, diminishes the association of clathrin in parallel with
AP-2. Because the beta subunit of the AP-2 complex also contains a clathrin
binding site, optimal association with soluble clathrin appears to depend on the
presence of at least two distinct clathrin-binding sites, and we show that a
second clathrin-binding sequence (480)LVDLD, located within the carboxyl-terminal
segment of epsin 1, also interacts with clathrin directly. The LMDLADV and LVDLD
sequences act cooperatively in clathrin recruitment assays, suggesting that they
bind to different sites on the clathrin-terminal domain. The evolutionary
conservation of similar clathrin-binding sequences in several metazoan epsin-like
molecules suggests that the ability to establish multiple protein-protein
contacts within a developing clathrin-coated bud is an important aspect of epsin
function.
PMID- 10692453
TI - The role of the conserved box E residues in the active site of the Escherichia
coli type I signal peptidase.
AB - Type I signal peptidases are integral membrane proteins that function to remove
signal peptides from secreted and membrane proteins. These enzymes carry out
catalysis using a serine/lysine dyad instead of the prototypical
serine/histidine/aspartic acid triad found in most serine proteases. Site
directed scanning mutagenesis was used to obtain a qualitative assessment of
which residues in the fifth conserved region, Box E, of the Escherichia coli
signal peptidase I are critical for maintaining a functional enzyme. First, we
find that there is no requirement for activity for a salt bridge between the
invariant Asp-273 and the Arg-146 residues. In addition, we show that the
conserved Ser-278 is required for optimal activity as well as conserved salt
bridge partners Asp-280 and Arg-282. Finally, Gly-272 is essential for signal
peptidase I activity, consistent with it being located within van der Waals
proximity to Ser-278 and general base Lys-145 side-chain atoms. We propose that
replacement of the hydrogen side chain of Gly-272 with a methyl group results in
steric crowding, perturbation of the active site conformation, and specifically,
disruption of the Ser-90/Lys-145 hydrogen bond. A refined model is proposed for
the catalytic dyad mechanism of signal peptidase I in which the general base Lys
145 is positioned by Ser-278, which in turn is held in place by Asp-280.
PMID- 10692454
TI - A-Myb up-regulates Bcl-2 through a Cdx binding site in t(14;18) lymphoma cells.
AB - In follicular lymphoma, bcl-2 is translocated to the immunoglobulin heavy chain
locus leading to deregulation of bcl-2 expression. We examined the role of Myb
proteins in the regulation of bcl-2 expression in lymphoma cells. We showed that
A-Myb up-regulates bcl-2 promoter activity. Northern and Western analyses
demonstrated that A-Myb was expressed in the DHL-4 t(14;18) cell line. In
t(14;18) cells and mature B cells, A-Myb up-regulated bcl-2 expression, whereas B
and c-Myb had little effect on bcl-2 gene expression. Deletion analysis of the
bcl-2 5'-region identified a region responsive to A-Myb in t(14;18) cells. A
potential binding site for the Cdx homeodomain proteins was located in this
sequence. Analysis of the A-Myb-responsive region by UV cross-linking experiments
revealed that a 32-kDa protein formed a complex with this region, but direct
binding by Myb proteins could not be demonstrated. A-Myb could be recovered along
with Cdx2 when nuclear extracts were passed over the Cdx site. Mutagenesis of the
Cdx binding site abolished binding by the 32-kDa protein and significantly
reduced the ability of A-Myb to induce bcl-2 expression. A strong induction of
bcl-2 P2 promoter activity was observed in cotransfection studies of DHL-4 cells
with the A-Myb and Cdx2 expression vectors, and increased endogenous Bcl-2
protein expression was observed in B cells transfected with A-Myb and/or Cdx2
expression constructs.
PMID- 10692455
TI - Phosphatidylglycerol is involved in the dimerization of photosystem II.
AB - Photosystem II core dimers (450 kDa) and monomers (230 kDa) consisting of CP47,
CP43, the D1 and D2 proteins, the extrinsic 33-kDa subunit, and the low molecular
weight polypeptides PsbE, PsbF, PsbH, PsbI, PsbK, PsbL, PsbTc, and PsbW were
isolated by sucrose density gradient centrifugation. The photosystem II core
dimers were treated with phospholipase A2 (PL-A2), which cuts
phosphatidylglycerol (PG) and phosphatidylcholine molecules at the sn-2 position.
The PL-A2-treated dimers dissociated into two core monomers and further, yielding
a CP47-D1-D2 subcomplex and CP43. Thin layer chromatography showed that
photosystem II dimers contained four times more PG than their monomeric
counterparts but with similar levels of phosphatidylcholine. Consistent with this
was the finding that, compared with monomers, the dimers contained a higher level
of trans-hexadecanoic fatty acid (C16:1Delta3tr), which is specific to PG of the
thylakoid membrane. Moreover, treatment of dimers with PL-A2 increased the free
level of this fatty acid specific to PG compared with untreated dimers. Further
evidence that PG is involved in stabilizing the dimeric state of photosystem II
comes from reconstitution experiments. Using size exclusion chromatography, it
was shown that PG containing C16:1Delta3tr, but not other lipid classes, induced
significant dimerization of isolated photosystem II monomers. Moreover, this
dimerization was observed by electron crystallography when monomers were
reconstituted into thylakoid lipids containing PG. The unit cell parameters, p2
symmetry axis, and projection map of the reconstituted dimer was similar to that
observed for two-dimensional crystals of the native dimer.
PMID- 10692456
TI - Tissue specificity of E subunit isoforms of plant vacuolar H(+)-ATPase and
existence of isotype enzymes.
AB - Immunoblot analyses and partial amino acid sequencings revealed that both the 40-
(E1) and 37-kDa (E2) subunits of V-ATPase in the pea epicotyl were E subunit
isoforms. Similarly, both the 35- (D1) and 29-kDa (D2) subunits were D subunit
isoforms, although the similarity of the amino acid sequences is still unknown.
In immunoblot analyses, two or three E subunit isoforms with molecular masses
ranging from 29 to 40 kDa were detected in other plants. Two isotypes of V-ATPase
from the pea epicotyl were separated by ion exchange chromatography and had
subunit compositions differing only in the ratio of E1 and E2. There was a
difference in the V(max) and K(m) of ATP hydrolysis between the two isotypes. E1
was scarcely detected in crude membrane fractions from the leaf and cotyledon,
while E2 was detected in fractions from all of the tissues examined. The
compositions of D subunit isoforms in the leaf and epicotyl were different, and
the vacuolar membrane in the leaf did not contain D2. The efficiency of H(+)
pumping activity in the vacuolar membrane of the leaf was higher than that of the
epicotyl. The results suggest that the presence of the isoforms of D and E
subunits is characteristic to plants and that the isoforms are closely related to
the enzymatic properties.
PMID- 10692457
TI - Syntaxin 7 mediates endocytic trafficking to late endosomes.
AB - The lysosome functions are ensured by accurate membrane trafficking in the cell.
We found that mouse syntaxin 7 could complement yeast vam3 and pep12 mutants
defective in docking/fusion to vacuolar and prevacuolar membranes, respectively.
Immunohistochemical studies showed that syntaxin 7 is localized to late
endosomes, but not to early endosomes. Induced expression of mutant syntaxin 7
blocked endocytic transport from early to late endosomes but did not block the
transport of cathepsin D and lamp-2 from the trans-Golgi network to lysosomes.
Thus, syntaxin 7 mediates the endocytic trafficking from early endosomes to late
endosomes and lysosomes. These results also suggest that the biosynthetic pathway
utilizes a different machinery from that of the endocytic pathway in the
docking/fusion to late endosomes.
PMID- 10692458
TI - The 8-nucleotide-long RNA:DNA hybrid is a primary stability determinant of the
RNA polymerase II elongation complex.
AB - The sliding clamp model of transcription processivity, based on extensive studies
of Escherichia coli RNA polymerase, suggests that formation of a stable
elongation complex requires two distinct nucleic acid components: an 8-9-nt
transcript-template hybrid, and a DNA duplex immediately downstream from the
hybrid. Here, we address the minimal composition of the processive elongation
complex in the eukaryotes by developing a method for promoter-independent
assembly of functional elongation complex of S. cerevisiae RNA polymerase II from
synthetic DNA and RNA oligonucleotides. We show that only one of the nucleic acid
components, the 8-nt RNA:DNA hybrid, is necessary for the formation of a stable
elongation complex with RNA polymerase II. The double-strand DNA upstream and
downstream of the hybrid does not affect stability of the elongation complex.
This finding reveals a significant difference in processivity determinants of RNA
polymerase II and E. coli RNA polymerase. In addition, using the imperfect
RNA:DNA hybrid disturbed by the mismatches in the RNA, we show that nontemplate
DNA strand may reduce the elongation complex stability via the reduction of the
RNA:DNA hybrid length. The structure of a "minimal stable" elongation complex
suggests a key role of the RNA:DNA hybrid in RNA polymerase II processivity.
PMID- 10692459
TI - 5-hydroxyconiferyl aldehyde modulates enzymatic methylation for syringyl
monolignol formation, a new view of monolignol biosynthesis in angiosperms.
AB - S-Adenosyl-L-methionine-dependent caffeate O-methyltransferase (COMT, EC 2.1.1.6)
has traditionally been thought to catalyze the methylation of caffeate and 5-
hydroxyferulate for the biosynthesis of syringyl monolignol, a lignin constituent
of angiosperm wood that enables efficient lignin degradation for cellulose
production. However, recent recognition that coniferyl aldehyde prevents 5
hydroxyferulate biosynthesis in lignifying tissue, and that the hydroxylated form
of coniferyl aldehyde, 5-hydroxyconiferyl aldehyde, is an alternative COMT
substrate, demands a re-evaluation of the role of COMT during monolignol
biosynthesis. Based on recombinant aspen (Populus tremuloides) COMT enzyme
kinetics coupled with mass spectrometry analysis, this study establishes for the
first time that COMT is in fact a 5-hydroxyconiferyl aldehyde O-methyltransferase
(AldOMT), and that 5-hydroxyconiferyl aldehyde is both the preferred AldOMT
substrate and an inhibitor of caffeate and 5-hydroxyferulate methylation, as
measured by K(m) and K(i) values. 5-Hydroxyconiferyl aldehyde also inhibited the
caffeate and 5-hydroxyferulate methylation activities of xylem proteins from
various angiosperm tree species. The evidence that syringyl monolignol
biosynthesis is independent of caffeate and 5-hydroxyferulate methylation
supports our previous discovery that coniferyl aldehyde prevents ferulate 5
hydroxylation and at the same time ensures a coniferyl aldehyde 5-hydroxylase
(CAld5H)-mediated biosynthesis of 5-hydroxyconiferyl aldehyde. Together, our
results provide conclusive evidence for the presence of a CAld5H/AldOMT-catalyzed
coniferyl aldehyde 5-hydroxylation/methylation pathway that directs syringyl
monolignol biosynthesis in angiosperms.
PMID- 10692460
TI - Identification and characterization of Elongin A2, a new member of the Elongin
family of transcription elongation factors, specifically expressed in the testis.
AB - The Elongin complex stimulates the rate of transcription elongation by RNA
polymerase II by suppressing the transient pausing of the polymerase at many
sites along the DNA template. Elongin is composed of a transcriptionally active A
subunit and two small regulatory B and C subunits, the latter of which bind
stably to each other to form a binary complex that interacts with Elongin A and
strongly induces its transcriptional activity. To further understand the roles of
Elongin in transcriptional regulation, we attempted to identify Elongin-related
proteins. Here, we report on the cloning, expression, and characterization of
human Elongin A2, a novel transcription elongation factor that exhibited 47%
identity and 61% similarity to Elongin A. Biochemical studies have shown that
Elongin A2 stimulates the rate of transcription elongation by RNA polymerase II
and is capable of forming a stable complex with Elongin BC. However, in contrast
to Elongin A, its transcriptional activity is not activated by Elongin BC.
Northern blot analysis revealed that Elongin A2 mRNA was specifically expressed
in the testis, suggesting that Elongin A2 may regulate the transcription of
testis-specific genes.
PMID- 10692461
TI - Norepinephrine- and phorbol ester-induced phosphorylation of alpha(1a)-adrenergic
receptors. Functional aspects.
AB - Maximal adrenergic responses in Rat-1 fibroblasts expressing alpha(1a)-adrenergic
receptors are not blocked by activation of protein kinase C. In contrast,
activation of protein kinase C induces the phosphorylation of alpha(1b)
adrenoreceptors and blocks their actions. The effect of norepinephrine and
phorbol esters on alpha(1a)-adrenoreceptor phosphorylation and coupling to G
proteins were studied. Both stimuli lead to dose-dependent receptor
phosphorylation. Interestingly, protein kinase C activation affected to a much
lesser extent the actions of alpha(1a)-adrenergic receptors than those of the
alpha(1b) subtype (norepinephrine elicited increases in calcium in whole cells
and [(35)S]GTPgammaS binding to membranes). Basal phosphorylation of alpha(1a)
adrenergic receptors was much less than that observed with the alpha(1b) subtype.
The carboxyl terminus seems to be the main domain for receptor phosphorylation.
Therefore, chimeric receptors, where the carboxyl-terminal tails of alpha(1a) and
alpha(1b) adrenergic receptors were exchanged, were constructed and expressed.
alpha(1a)-Adrenoreceptors wearing the carboxyl tail of the alpha(1b) subtype had
a high basal phosphorylation and displayed a strong phosphorylation in response
to norepinephrine and phorbol esters. Our results demonstrate that stimulation of
alpha(1a)-adrenergic receptor, or activation of protein kinase C, leads to
alpha(1a)-adrenergic receptor phosphorylation. alpha(1a)-Adrenoreceptors are
affected to a much lesser extent than alpha(1b)-adrenoreceptors by protein kinase
C activation.
PMID- 10692462
TI - Deletion of the COOH terminus converts the ST5 p70 protein from an inhibitor of
RAS signaling to an activator with transforming activity in NIH-3T3 cells.
AB - Expression of the human protein ST5-p70 correlates with reduced tumorigenic
phenotype in mammalian cells, reverts their transformed phenotype, and restores
their contact-dependent growth. Furthermore, expression of p70 in COS-7 cells
suppresses activation of mitogen activated protein kinase MAPK/ERK2 by the
largest ST5 product, p126, in response to epidermal growth factor stimulation.
Here we show that deletions of the COOH-terminal region of p70 transform NIH3T3
cells and induce their anchorage-independent growth. Analysis of signaling
leading to MAPK/ERK2 stimulation revealed that in COS-7 cells, expression of
either p70-DeltaC1 or p70-DeltaC2 markedly enhanced ERK2 activity in a growth
factor-independent manner. Whereas wild-type p70 slightly inhibited ERK2
activation by RAS and MEK2, co-expression or p70-DeltaC1 or p70-DeltaC2 with
either protein stimulated ERK2 cooperatively. This activity was completely
blocked by the dominant negative mutants RAS17N or MEKAA, suggesting that p70
functions upstream of RAS. Unlike wild-type p70, expression of p70-DeltaC1 or p70
DeltaC2 mutant did not interfere with the ability of ST5-p126 to stimulate ERK2.
Taken together, the data suggest that the COOH-terminal tail, residues 489-609,
contains some of the critical determinants for the function of p70. Loss of this
region converts the protein from an inhibitor to a constitutive activator of the
RAS-ERK2 pathway.
PMID- 10692463
TI - Structural determinants required for apical sorting of an intestinal brush-border
membrane protein.
AB - The distinct protein and lipid constituents of the apical and basolateral
membranes in polarized cells are sorted by specific signals. O-Glycosylation of a
highly polarized intestinal brush-border protein sucrase isomaltase is implicated
in its apical sorting through interaction with sphingolipid-cholesterol
microdomains. We characterized the structural determinants required for this
mechanism by focusing on two major domains in pro-SI, the membrane anchor and the
Ser/Thr-rich stalk domain. Deletion mutants lacking either domain, pro
SI(DeltaST) (stalk-free) and pro-SI(DeltaMA) (membrane anchor-free), were
constructed and expressed in polarized Madin-Darby canine kidney cells. In the
absence of the membrane anchoring domain, pro-SI(DeltaMA) does not associate with
lipid rafts and the mutant is randomly delivered to both membranes. Therefore,
the O-glycosylated stalk region is not sufficient per se for the high fidelity of
apical sorting of pro-SI. Pro-SI(DeltaST) does not associate either with lipid
rafts and its targeting behavior is similar to that of pro-SI(DeltaMA). Only wild
type pro-SI containing both determinants, the stalk region and membrane anchor,
associates with lipid microdomains and is targeted correctly to the apical
membrane. However, not all sequences in the stalk region are required for apical
sorting. Only O-glycosylation of a stretch of 12 amino acids (Ala(37)-Pro(48))
juxtapose the membrane anchor is required in conjunction with the membrane
anchoring domain for correct targeting of pro-SI to the apical membrane. Other O
glycosylated domains within the stalk (Ala(49)-Pro(57)) are not sufficient for
apical sorting. We conclude that the recognition signal for apical sorting of pro
SI comprises O-glycosylation of the Ala(37)-Pro(48) stretch and requires the
presence of the membrane anchoring domain.
PMID- 10692464
TI - Biosynthesis and post-translational processing of lectin-like oxidized low
density lipoprotein receptor-1 (LOX-1). N-linked glycosylation affects cell
surface expression and ligand binding.
AB - LOX-1 (lectin-like oxidized low density lipoprotein receptor-1) is a type II
membrane protein belonging to the C-type lectin family that can act as a cell
surface receptor for atherogenic oxidized low density lipoprotein (Ox-LDL) and
may play crucial roles in atherogenesis. In this study, we show, by pulse-chase
labeling and glycosidase digestion, that LOX-1 is synthesized as a 40-kDa
precursor protein with N-linked high mannose carbohydrate chains (pre-LOX-1),
which is subsequently further glycosylated and processed into the 48-kDa mature
form within 40 min. Furthermore, when treated with an N-glycosylation inhibitor,
tunicamycin, both tumor necrosis factor-alpha-activated bovine aortic endothelial
cells and CHO-K1 cells stably expressing bovine LOX-1 (BLOX-1-CHO) exclusively
produced a 32-kDa deglycosylated form of LOX-1. Cell enzyme-linked immunosorbent
assay, flow cytometry, and immunofluorescence confocal microscopy demonstrated
that the deglycosylated form of LOX-1 is not efficiently transported to the cell
surface, but is retained in the endoplasmic reticulum or Golgi apparatus in tumor
necrosis factor-alpha-activated bovine aortic endothelial cells, but not in BLOX
1-CHO cells. Radiolabeled Ox-LDL binding studies revealed that the deglycosylated
form of LOX-1 expressed on the cell surface of BLOX-1-CHO cells has a reduced
affinity for Ox-LDL binding. Taken together, N-linked glycosylation appears to
play key roles in the cell-surface expression and ligand binding of LOX-1.
PMID- 10692465
TI - Binding of factor VIIa to tissue factor on keratinocytes induces gene expression.
AB - Binding of the zymogen serine protease Factor VII (FVII) to its cellular cofactor
tissue factor (TF) triggers blood coagulation. Several recent reports have
suggested that the formation of this complex may serve additional functions. We
have used cDNA arrays to study differential gene expression in response to the
interaction of activated FVII (FVIIa) with TF on a human keratinocyte cell line.
Of 931 mRNA species observed up to 6 h after FVIIa (10 nM) addition, 24 were
significantly up-regulated in what may resemble a wound-type response. Responders
included mRNA species coding for transcription regulators (c-fos, egr-1, ETR101,
BTEB2, c-myc, fra-1, and tristetraproline), growth factors (amphiregulin, hbEGF,
CTGF, and FGF-5), proinflammatory cytokines (IL-1beta, IL-8, LIF, and MIP2alpha),
proteins involved in cellular reorganization/migration (RhoE, uPAR, and
collagenases 1 and 3), and others (PAI-2, cyclophilin, GADD45, Jagged1, and
prostaglandin E(2) receptor). The transcriptional response to FVIIa was abrogated
by antibodies to TF and left unaffected by hirudin. The pattern of genes induced
suggests that the FVIIa.TF complex may play an active role in early wound repair
as well as hemostasis. The former is a novel function ascribed to the complex
that may also be contributing to the pathophysiology of unwarranted TF
expression.
PMID- 10692466
TI - Spatial requirements for 15-(R)-hydroxy-5Z,8Z,11Z, 13E-eicosatetraenoic acid
synthesis within the cyclooxygenase active site of murine COX-2. Why acetylated
COX-1 does not synthesize 15-(R)-hete.
AB - The two isoforms of cyclooxygenase, COX-1 and COX-2, are acetylated by aspirin at
Ser-530 and Ser-516, respectively, in the cyclooxygenase active site. Acetylated
COX-2 is essentially a lipoxygenase, making 15-(R)-hydroxyeicosatetraenoic acid
(15-HETE) and 11-(R)-hydroxyeicosatetraenoic acid (11-HETE), whereas acetylated
COX-1 is unable to oxidize arachidonic acid to any products. Because the COX
isoforms are structurally similar and share approximately 60% amino acid
identity, we postulated that differences within the cyclooxygenase active sites
must account for the inability of acetylated COX-1 to make 11- and 15-HETE.
Residues Val-434, Arg-513, and Val-523 were predicted by comparison of the COX-1
and -2 crystal structures to account for spatial and flexibility differences
observed between the COX isoforms. Site-directed mutagenesis of Val-434, Arg-513,
and Val-523 in mouse COX-2 to their COX-1 equivalents resulted in abrogation of
11- and 15-HETE production after aspirin treatment, confirming the hypothesis
that these residues are the major isoform selectivity determinants regulating
HETE production. The ability of aspirin-treated R513H mCOX-2 to make 15-HETE,
although in reduced amounts, indicates that this residue is not an alternate
binding site for the carboxylate of arachidonate and that it is not the only
specificity determinant regulating HETE production. Further experiments were
undertaken to ascertain whether the steric bulk imparted by the acetyl moiety on
Ser-530 prevented the omega-end of arachidonic acid from binding within the top
channel cavity in mCOX-2. Site-directed mutagenesis was performed to change Val
228, which resides at the junction of the main cyclooxygenase channel and the top
channel, and Gly-533, which is in the top channel. Both V228F and G533A produced
wild type-like product profiles, but, upon acetylation, neither was able to make
HETE products. This suggests that arachidonic acid orientates in a L-shaped
binding configuration in the production of both prostaglandin and HETE products.
PMID- 10692467
TI - Proteolytic processing and assembly of the C5 subunit into the proteasome
complex.
AB - Assembly of mammalian 20 S proteasomes from individual subunits is beginning to
be investigated. Proteasomes are made of four heptameric rings in the
configuration alpha7beta7beta7alpha7. By using anti-proteasome and anti-subunit
specific antibodies, we characterized the processing and assembly of the beta
subunit C5. The C5 precursor (25 kDa) remains as a free non-assembled polypeptide
in the cell. The conversion of the C5 precursor to mature C5 (23 kDa) occurs
concomitantly with its incorporation into 15 S proteasome intermediate and 20 S
mature proteasome complexes. This processing is dependent on proteasome activity
and takes place in the cytosol. These results are not fully compatible with the
hypothesis that postulates that assembly of proteasomes takes place via a "half
proteasome" intermediate that contains one full alpha-ring and one full beta-ring
of unprocessed beta subunit precursors.
PMID- 10692468
TI - Characterization of a repressor element and a juxtaposed tissue-restricted
activator element located on the distal neu gene promoter.
AB - The proto-oncogene neu (HER2 or c-erbB2) is overexpressed with or without gene
amplification in 20-30% of breast cancers. In patients, neu amplification or
overexpression in breast and ovarian cancer correlates with poor prognosis and
tumor resistance to chemotherapy. neu-induced transformation can be reversed by
the suppression of neu gene transcription. To further understand how neu gene
transcription is regulated and to identify a possible transcriptional
repressor(s) of neu, we identified a negative regulatory element known previously
to be located within a 1-kilobase (kb) DNA fragment of an unknown sequence,
upstream of the proximal neu gene promoter. One of several DNA fragments
subcloned from this region suppressed transcriptional activity of the proximal
neu gene promoter. Sequencing of the 1-kb fragment confirmed the location of the
repressor element to be between an AluI and a RsaI sites, around 1.4 kb upstream
to the translation start site. Various deletions were introduced into the AluI
RsaI fragment and subcloned into both the native neu promoter and a heterologous
thymidine kinase promoter. Subsequent transfections and reporter gene assays in
cell lines of various tissues of origin confirmed and narrowed the repressor
activity to a 120-base pair NlaIV-MslI fragment located between -1385 and -1266.
Importantly, specific protein binding activity to this element could be detected
with nuclear extracts isolated from these cell lines. In contrast, a 28-base pair
MslI-RsaI fragment (-1265 to -1238), located immediately 3' of the putative
repressor element, was found to form protein-DNA complexes with only nuclear
extracts isolated from a colon carcinoma cell line. This specific protein binding
activity correlated with a previously unknown transcriptional stimulatory
activity only in this cell line.
PMID- 10692469
TI - Synergy of SF1 and RAR in activation of Oct-3/4 promoter.
AB - The Oct-3/4 transcription factor is expressed in the earliest stages of
embryogenesis, and is thus likely to play an important role in regulation of
initial decisions in development. For the first time, we have shown that SF1 and
Oct-3/4 are co-expressed in embryonal carcinoma (EC) P19 cells, and their
expression is down-regulated with very similar kinetics following retinoic acid
(RA) induced differentiation of these cells, suggesting a functional relationship
between the two. Previously, we have shown that the Oct-3/4 promoter harbors an
RA-responsive element, RAREoct, which functions in EC cells as a binding site for
positive regulators of transcription, such as RAR and RXR. In this study we have
identified in the Oct-3/4 promoter two novel SF1-binding sites: SF1(a) and
SF1(b). The proximal site, SF1(a), is located within the RAREoct, and the distal
site, SF1(b), is located between nucleotide -193 and -209 of the Oct-3/4
promoter. Both sites contribute to activation of Oct-3/4 promoter in EC cells,
with SF1(a) playing a more crucial role. SF1, and its isoforms ELP2 and ELP3 bind
to both SF1 sites and activate the Oct-3/4 promoter. This activation depends on
the presence of SF1 DNA-binding domain. Thus, Oct-3/4 is the first EC-specific
gene reported that is regulated by SF1. Interestingly, SF1 and RAR form a novel
complex on the RAREoct sequence that synergistically activate the Oct-3/4
promoter. Both RARE and SF1 cis regulatory elements, as well as the SF1 DNA
binding domain, are needed for this synergism. SF1 and Oct-3/4 transcription
factors play a role in the same developmental regulatory cascade.
PMID- 10692470
TI - Inherited defects of sodium-dependent glutamate transport mediated by
glutamate/aspartate transporter in canine red cells due to a decreased level of
transporter protein expression.
AB - Canine red cells have a high affinity Na(+)/K(+)-dependent glutamate transporter.
We herein demonstrate that this transport is mediated by the canine homologue of
glutamate/aspartate transporter (GLAST), one of the glutamate transporter
subtypes abundant in the central nervous system. We also demonstrate that GLAST
is the most ubiquitous glutamate transporter among the transporter subtypes that
have been cloned to date. The GLAST protein content was extremely reduced in
variant red cells, low glutamate transport (LGlut) red cells characterized by an
inherited remarkable decrease in glutamate transport activity. All LGluT dogs
carried a missense mutation of Gly(492) to Ser (G492S) in either the heterozygous
or homozygous state. The GLAST protein with G492S mutation was fully functional
in glutamate transport in Xenopus oocytes. However, G492S GLAST exhibited a
marked decrease in activity after the addition of cycloheximide, while the wild
type showed no significant change, indicating that G492S GLAST was unstable
compared with the wild-type transporter. Moreover, LGluT dogs, but not normal
dogs, heterozygous for the G492S mutation showed a selective decrease in the
accumulation of GLAST mRNA from the normal allele. Based on these findings, we
conclude that a complicated heterologous combination of G492S mutation and some
transcriptional defect contributes to the pathogenesis of the LGluT red cell
phenotype.
PMID- 10692471
TI - Transforming growth factor-beta1 enhances Ha-ras-induced expression of
cyclooxygenase-2 in intestinal epithelial cells via stabilization of mRNA.
AB - Oncogenic ras induces the expression of cyclooxygenase-2 (COX-2) in a variety of
cells. Here we investigated the role of transforming growth factor-beta (TGF
beta) in the Ras-mediated induction of COX-2 in intestinal epithelial cells (RIE
1). RIE-1 cells were transfected with an inducible Ha-Ras(Val12) cDNA and are
referred as RIE-iRas cells. the addition of 5 mM isopropyl-1-thio-beta-D
galactopyranoside (IPTG) induced the expression of Ha-Ras(Val12), closely
followed by an increase in the expression of COX-2. Neutralizing anti-TGF-beta
antibody partially blocked the Ras-induced increase in COX-2. Combined treatment
with IPTG and TGF-beta1 resulted in a 20-50-fold increase in the levels of COX-2
mRNA. The t1/2 of COX-2 mRNA was increased from 13 to 24 min by Ha-Ras induction
alone. The addition of TGF-beta1 further stabilized the COX-2 mRNA (t1/2 > 50
min). Stable transfection of a luciferase reporter construct containing the COX-2
3'-untranslated region (3'-UTR) revealed that TGF-beta1 treatment and Ras
induction each stabilized the COX-2 3'-UTR. Combined treatment with IPTG and TGF
beta1 synergistically increased the luciferase activity. Furthermore, a conserved
AU-rich region located in the proximal COX-2 3'-UTR is required for maximal
stabilization of COX-2 3'-UTR by Ras or TGF-beta1 and is necessary for the
synergistic stabilization of COX-2 3'-UTR by oncogenic Ras and TGF-beta1.
PMID- 10692472
TI - The insect salivary protein, prolixin-S, inhibits factor IXa generation and Xase
complex formation in the blood coagulation pathway.
AB - Prolixin-S is a salivary anticoagulant of the blood-sucking insect, Rhodnius
prolixus, and known as an inhibitor of the intrinsic Xase. We report here its
inhibitory mechanisms with additional important anticoagulation activities. We
found prolixin-S specifically bound to factor IX/IXa in the presence of Ca(2+)
ions. Light scattering and surface plasmon resonance studies showed that prolixin
S interfered with factor IX/IXa binding to the phospholipid membrane, indicating
that prolixin-S inhibit Xase activity of factor IXa by interference with its Xase
complex formation. Furthermore, reconstitution experiments showed that prolixin-S
binding to factor IX strongly inhibited factor IXa generation by factor XIa. We
also found that prolixin-S inhibited factor IXa generation by factor VIIa-tissue
factor complex and factor IXalpha generation by factor Xa. These results suggest
that prolixin-S inhibits both intrinsic and extrinsic coagulations by sequential
inhibition of all coagulation pathways in which factor IX participates. It was
also suggested that prolixin-S may bind to factor IX/IXa by recognizing
conformational change of the Gla domain induced by Ca(2+) binding.
PMID- 10692473
TI - Correlated oscillations in glucose consumption, oxygen consumption, and
intracellular free Ca(2+) in single islets of Langerhans.
AB - Micron-sized sensors were used to monitor glucose and oxygen levels in the
extracellular space of single islets of Langerhans in real-time. At 10 mM
glucose, oscillations in intraislet glucose concentration were readily detected.
Changes in glucose level correspond to changes in glucose consumption by
glycolysis balanced by mass transport into the islet. Oscillations had a period
of 3.1 +/- 0.2 min and amplitude of 0.8 +/- 0.1 mM glucose (n = 21). Superimposed
on these oscillations were faster fluctuations in glucose level during the
periods of low glucose consumption. Oxygen level oscillations that were out of
phase with the glucose oscillations were also detected. Oscillations in both
oxygen and glucose consumption were strongly dependent upon extracellular Ca(2+)
and sensitive to nifedipine. Simultaneous measurements of glucose with
intracellular Ca(2+) ([Ca(2+)](i)) revealed that decreases in [Ca(2+)](i)
preceded increases in glucose consumption by 7.4 +/- 2.1 s during an oscillation
(n = 9). Conversely, increases in [Ca(2+)](i) preceded increases in oxygen
consumption by 1.5 +/- 0.2 s (n = 4). These results suggest that during
oscillations, bursts of glycolysis begin after Ca(2+) has stopped entering the
cell. Glycolysis stimulates further Ca(2+) entry, which in turn stimulates
increases in respiration. The data during oscillation are in contrast to the time
course of events during initial exposure to glucose. Under these conditions, a
burst of oxygen consumption precedes the initial rise in [Ca(2+)](i). A model to
explain these results is described.
PMID- 10692474
TI - Ionizing radiation exposure results in up-regulation of Ku70 via a p53/ataxia
telangiectasia-mutated protein-dependent mechanism.
AB - Genome damaging events, such as gamma-irradiation exposure, result in the
induction of pathways that activate DNA repair mechanisms, halt cell cycle
progression, and/or trigger apoptosis. We have investigated the effects of gamma
irradiation on cellular levels of the Ku autoantigens. Ku70 and Ku80 have been
shown to form a heterodimeric complex that can bind tightly to free DNA ends and
activate the protein kinase DNA-PKcs. We have found that irradiation results in
an up-regulation of cellular levels of Ku70, but not Ku80, and that this enhanced
level of Ku70 accumulates within the nucleus. Further, we uncovered that the
postirradiation up-regulation of Ku70 utilizes a mechanism that is dependent on
both p53 and damage response protein kinase ATM (ataxia-telangiectasia-mutated);
however, the activation of DNA-PK does not require Ku70 up-regulation. These
findings suggest that Ku70 up-regulation provides the cell with a means of
assuring either proper DNA repair or an appropriate response to DNA damage
independent of DNA-PKcs activation.
PMID- 10692475
TI - Upstream tissue inhibitor of metalloproteinases-1 (TIMP-1) element-1, a novel and
essential regulatory DNA motif in the human TIMP-1 gene promoter, directly
interacts with a 30-kDa nuclear protein.
AB - Elevated expression of the tissue inhibitor of metalloproteinases-1 (TIMP-1)
protein and mRNA has been reported in human diseases including cancers and tissue
fibrosis. Regulation of TIMP-1 gene expression is mainly mediated at the level of
gene transcription and involves the activation of several well known
transcription factors including those belonging to the AP-1, STAT, and Pea3/Ets
families. In the current study, we have used DNase-1 footprinting to identify a
new regulatory element (5'-TGTGGTTTCCG-3') present in the human TIMP-1 gene
promoter. Mutagenesis and transfection studies in culture-activated rat hepatic
stellate cells and the human Jurkat T cell line demonstrated that the new element
named upstream TIMP-1 element-1 (UTE-1) is essential for transcriptional activity
of the human TIMP-1 promoter. Electrophoretic mobility shift assay studies
revealed that UTE-1 can form protein-DNA complexes of distinct mobilities with
nuclear extracts from a variety of mammalian cell types and showed that induction
of a high mobility UTE-1 complex is associated with culture activation of freshly
isolated rat hepatic stellate cells. A combination of UV-cross-linking and
Southwestern blotting techniques demonstrated that UTE-1 directly interacts with
a 30-kDa nuclear protein that appears to be present in all cell types tested. We
conclude that UTE-1 is a novel regulatory element that in combination with its
cellular binding proteins may be an important component of the mechanisms
controlling TIMP-1 expression in normal and pathological states.
PMID- 10692477
TI - Functional expression of a multisubstrate deoxyribonucleoside kinase from
Drosophila melanogaster and its C-terminal deletion mutants.
AB - The occurrence of a deoxyribonucleoside kinase in Drosophila melanogaster (Dm
dNK) with remarkably broad substrate specificity has recently been indicated
(Munch-Petersen, B., Piskur, J., and Sondergaard, L. (1998) J. Biol. Chem. 273,
3926-3931). To prove that the capacity to phosphorylate all four
deoxyribonucleosides is in fact associated to one polypeptide chain, partially
sequenced cDNA clones, originating from the Berkeley Drosophila genome sequencing
project, were searched for homology with human deoxyribonucleoside kinases. The
total sequence of one cDNA clone and the corresponding genomic DNA was determined
and expressed in Escherichia coli as a glutathione S-transferase fusion protein.
The purified and thrombin cleaved recombinant protein phosphorylated the four
deoxyribonucleosides with high turnover and K(m) values similar to those of the
native Dm-dNK, as well as the four ribonucleosides and many therapeutical
nucleoside analogs. Dm-dNK has apparently the same origin as the mammalian
kinases, thymidine kinase 2, deoxycytidine kinase, deoxyguanosine kinase, and the
herpes viral thymidine kinases, but it has a unique C terminus that seems to be
important for catalytic activity and specificity. The C-terminal 20 amino acids
were dispensable for phosphorylation of deoxyribonucleosides but necessary for
full activity with purine ribonucleosides. Removal of the C-terminal 20 amino
acids increased the specific activity 2-fold, but 99% of the activity was lost
after removal of the C-terminal 30 amino acids.
PMID- 10692476
TI - Characterization of alpha-crystallin-plasma membrane binding.
AB - Alpha-crystallin, a large lenticular protein complex made up of two related
subunits (alphaA- and alphaB-crystallin), is known to associate increasingly with
fiber cell plasma membranes with age and/or the onset of cataract. To understand
better the binding mechanism, we developed a sensitive membrane binding assay
using lens plasma membranes and recombinant human alphaA- and alphaB-crystallins
conjugated to a small fluorescent tag (Alexa350). Both alphaA and alphaB
homopolymer complexes, as well as a reconstituted 3:1 heteromeric complex, bind
to lens membranes in a specific, saturable, and partially irreversible manner
that is sensitive to both time and temperature. The amount of alpha-crystallin
that binds to the membrane increases under acidic pH conditions and upon removal
of exposed intrinsic membrane protein domains but is not affected at high ionic
strength, suggesting that alpha-crystallin binds to the fiber cell plasma
membranes mainly through hydrophobic interactions. The binding capacity and
affinity for the reconstituted 3:1 heteromeric complex were measured to be 3. 45
+/- 0.11 ng/microg of membrane and 4.57 +/- 0.50 x 10(-4) microg(-1) of membrane,
respectively. The present membrane binding data support the hypothesis that the
physical properties of a mixed alpha-crystallin complex may hold particular
relevance for the function of alpha-crystallin within the lens.
PMID- 10692478
TI - Expression and function of calcium binding domain chimeras of the integrins
alpha(IIb) and alpha(5).
AB - To further identify amino acid domains involved in the ligand binding specificity
of alpha(IIb)beta(3), chimeras of the conserved calcium binding domains of
alpha(IIb) and the alpha subunit of the fibronectin receptor alpha(5)beta(1) were
constructed. Chimeras that replaced all four calcium binding domains, replaced
all but the second calcium binding domain of alpha(IIb) with those of alpha(5),
or deleted all four calcium binding domains were synthesized but not expressed on
the cell surface. Additional chimeras exchanged subsets or all of the variant
amino acids in the second calcium binding domain, a region implicated in ligand
binding. Cell surface expression of each second calcium binding domain mutant
complexed with beta(3) was observed. Each second calcium binding domain mutant
was able to 1) bind to immobilized fibrinogen, 2) form fibrinogen-dependent
aggregates after treatment with dithiothreitol, and 3) bind the activation
dependent antibody PAC1 after LIBS 6 treatment. Soluble fibrinogen binding
studies suggested that there were only small changes in either the K(d) or B(max)
of any mutant. We conclude that chimeras of alpha(IIb) containing the second
calcium binding domain sequences of alpha(5) are capable of complexing with
beta(3), that the complexes are expressed on the cell surface, and that mutant
complexes are capable of binding both immobilized and soluble fibrinogen,
suggesting that the second calcium binding domain does not determine ligand
binding specificity.
PMID- 10692479
TI - Cloning, expression, and substrate specificity of a fungal chymotrypsin. Evidence
for lateral gene transfer from an actinomycete bacterium.
AB - Unlike trypsins, chymotrypsins have not until now been found in fungi. Expressed
sequence tag analysis of the deuteromycete Metarhizium anisopliae identified two
trypsins (family S1) and a novel chymotrypsin (CHY1). CHY1 resembles actinomycete
(bacterial) chymotrypsins (family S2) rather than other eukaryote enzymes (family
S1) in being synthesized as a precursor species (374 amino acids, pI/MW:
5.07/38,279) containing a large N-terminal fragment (186 amino acids). Chy1 was
expressed in Pichia pastoris yielding an enzyme with a chymotrypsin specificity
for branched aliphatic and aromatic C-terminal amino acids. This is predictable
as key catalytic residues determining the specificity of Streptomyces griseus
chymotrypsins are conserved with CHY1. Mature (secreted) CHY1 (pI/MW:
8.29/18,499) shows closest overall amino acid identity to S. griseus protease C
(55%) and clustered with other secreted bacterial S2 chymotrypsins that diverged
widely from animal and endocellular bacterial enzymes in phylogenetic trees of
the chymotrypsin superfamily. Conversely, actinomycete chymotrypsins are much
more closely related to fungal proteases than to other eubacterial sequences.
Complete genomes of yeast, gram eubacteria, archaebacteria, and mitochondria do
not contain paralogous genes. Expressed sequence tag data bases from other fungi
also lack chymotrypsin homologs. In light of this patchy distribution, we
conclude that chy1 probably arose by lateral gene transfer from an actinomycete
bacterium.
PMID- 10692480
TI - Ca(2+) requirement for high-affinity gamma-aminobutyric acid (GABA) binding at
GABA(B) receptors: involvement of serine 269 of the GABA(B)R1 subunit.
AB - The gamma-aminobutyric acid (GABA) receptor type B (GABA(B)R) is constituted of
at least two homologous proteins, GABA(B)R1 and GABA(B)R2. These proteins share
sequence and structural similarity with metabotropic glutamate and Ca(2+)-sensing
receptors, both of which are sensitive to Ca(2+). Using rat brain membranes, we
report here that the affinity of GABA and 3-aminopropylphosphinic acid for the
GABA(B)R receptor is decreased by a factor >10 in the absence of Ca(2+). Such a
large effect of Ca(2+) is not observed with baclofen or the antagonists CGP64213
and CGP56999A. In contrast to baclofen, the potency of GABA in stimulating
GTPgammaS binding in rat brain membranes is also decreased by a factor >10 upon
Ca(2+) removal. The potency for Ca(2+) in regulating GABA affinity was 37 microM.
In cells expressing GABA(B)R1, the potency of GABA, but not of baclofen, in
displacing bound (125)I-CGP64213 was similarly decreased in the absence of
Ca(2+). To identify residues that are responsible for the Ca(2+) effect, the
pharmacological profile and the Ca(2+) sensitivity of a series of GABA(B)R1
mutants were examined. The mutation of Ser269 into Ala was found to decrease the
affinity of GABA, but not of baclofen, and the GABA affinity was found not to be
affected upon Ca(2+) removal. Finally, the effect of Ca(2+) on the GABA(B)
receptor function is no longer observed in cells coexpressing this GABA(B)R1
S269A mutant and the wild-type GABA(B)R2. Taken together, these results show that
Ser269, which is conserved in the GABA(B)R1 protein from Caenorhabditis elegans
to mammals, is critical for the Ca(2+)-effect on the heteromeric GABA(B)
receptor.
PMID- 10692481
TI - Structure-activity relationship of staurosporine analogs in regulating expression
of endothelial nitric-oxide synthase gene.
AB - In human umbilical vein endothelial cells and in human umbilical vein endothelial
cell-derived EA.hy 926 cells, staurosporine (Stsp) and its glycosidic
indolocarbazole analogs 7-hydroxystaurosporine (UCN-01) and 4'-N-benzoyl
staurosporine (CGP 41251) enhanced nitric-oxide synthase (NOS) III mRNA
expression (analyzed by RNase protection assay), protein expression (determined
by Western blot), and activity [measured by rat fetal lung fibroblast (RFL-6)
reporter cell assay] in a concentration- and time-dependent manner. In contrast,
the bisindolylmaleimide analogs GF 109203X, Ro 31-8220 and Go 6983 had no effect
on NOS III expression, and Go 6976, a methyl- and cyanoalkyl-substituted
nonglycosidic indolocarbazole derivative of Stsp, even reduced NOS III expression
in a concentration-dependent fashion. The up-regulation of NOS III expression by
Stsp and analogs appears to be a transcriptional event because Stsp, 7
hydroxystaurosporine, and CGP 41251 enhanced the activity of a 1.6-kb human NOS
III promoter fragment transiently transfected into EA.hy 926 endothelial cells.
Stsp and analogs did not affect the stability of the NOS III mRNA. Stsp is known
as a potent protein kinase (PK) inhibitor. Data obtained with other kinase
inhibitors (and stimulators) indicated, however, that the effect of Stsp and
analogs on NOS III expression was unrelated to the activities of PKC, PKA, PKG,
or tyrosine kinase(s). Stsp analogs such as CGP 41251 also counteracted the NOS
III mRNA-decreasing effect of tumor necrosis factor-alpha. These findings
demonstrate that Stsp analogs represent a new class of compounds positively
interacting with the transcription of the endothelial NOS III gene. Such
compounds may prove useful in the prophylaxis and therapy of vascular disease.
PMID- 10692482
TI - Allosteric interactions between the antagonist prazosin and amiloride analogs at
the human alpha(1A)-adrenergic receptor.
AB - It has been demonstrated previously that amilorides can interact with a well
defined allosteric site on the human alpha(2A)-adrenergic receptor. In this
study, the question was explored as to whether the human alpha(1A)-adrenergic
receptor also possesses an equivalent allosteric site. The six amilorides
examined strongly increased the dissociation rate of the antagonist
[(3)H]prazosin from the alpha(1A)-adrenergic receptor in a concentration
dependent manner. With the parent amiloride, the dissociation data were well
fitted by an equation derived from the ternary complex allosteric model,
compatible with amiloride acting at a defined allosteric site on the alpha(1A)
adrenergic receptor. In contrast, the dissociation data for [(3)H]prazosin in the
presence of the amiloride analogs were not compatible with the equation derived
from a one-allosteric-site model, but could be fitted well by an equation derived
from a two-allosteric-site model. However, certain individual parameters could
not be resolved. The observed dissociation rate constants increased steeply with
increasing amiloride analog concentration, and in some cases the data could be
fitted with a logistic equation. The slope factors calculated from such fits were
1.2 to 2.1. It is concluded that the structure-binding relationships of the
amilorides at the alpha(1A)- and alpha(2A)-adrenergic receptors are different.
The interactions of the five amiloride analogs, but not the parent amiloride,
with the alpha(1A)-adrenergic receptor are compatible with the presence of two
(but not one) allosteric sites, and is thus more complex than that found for the
alpha(2A)-adrenergic receptor.
PMID- 10692483
TI - Modulation of dopamine D(2) receptor signaling by actin-binding protein (ABP
280).
AB - Proteins that bind to G protein-coupled receptors have recently been identified
as regulators of receptor anchoring and signaling. In this study, actin-binding
protein 280 (ABP-280), a widely expressed cytoskeleton-associated protein that
plays an important role in regulating cell morphology and motility, was found to
associate with the third cytoplasmic loop of dopamine D(2) receptors. The
specificity of this interaction was originally identified in a yeast two-hybrid
screen and confirmed by protein binding. The functional significance of the D(2)
receptor-ABP-280 association was evaluated in human melanoma cells lacking ABP
280. D(2) receptor agonists were less potent in inhibiting forskolin-stimulated
cAMP production in these cells. Maximal inhibitory responses of D(2) receptor
activation were also reduced. Further yeast two-hybrid experiments showed that
ABP-280 association is critically dependent on the carboxyl domain of the D(2)
receptor third cytoplasmic loop, where there is a potential serine
phosphorylation site (S358). Serine 358 was replaced with aspartic acid to mimic
the effects of receptor phosphorylation. This mutant (D(2)S358D) displayed
compromised binding to ABP-280 and coupling to adenylate cyclase. PKC activation
also generated D(2) receptor signaling attenuation, but only in ABP-containing
cells, suggesting a PKC regulatory role in D(2)-ABP association. A mechanism for
these results may be derived from a role of ABP-280 in the clustering of D(2)
receptors, as determined by immunocytochemical analysis in ABP-deficient and
replete cells. Our results suggest a new molecular mechanism of modulating D(2)
receptor signaling by cytoskeletal protein interaction.
PMID- 10692484
TI - Characterization of protein kinase chk1 essential for the cell cycle checkpoint
after exposure of human head and neck carcinoma A253 cells to a novel
topoisomerase I inhibitor BNP1350.
AB - Cellular topoisomerase I is an important target in cancer chemotherapy. A novel
karenitecin, BNP1350, is a topoisomerase I-targeting anticancer agent with
significant antitumor activity against human head and neck carcinoma A253 cells
in vitro. As a basis for future clinical trials of BNP1350 in human head and neck
carcinoma, in vitro studies were carried out to investigate its effect on DNA
damage and cell cycle checkpoint response. The treatment of A253 cells with
BNP1350 caused biphasic profiles of DNA fragmentation displayed from 0 to 48 h
after 2-h exposure. Pulsed-field gel electrophoresis demonstrated that the first
wave of DNA damage was mainly megabase DNA fragmentation, but the second wave of
DNA damage was 50- to 300-kb DNA fragmentation in addition to megabase DNA
damage. The cell cycle checkpoint response was characterized after exposure to
0.07 and 0.7 microM concentrations of BNP1350, the IC(50) and IC(90) values,
respectively. After exposure to a low concentration of BNP1350 (IC(50)), A253
cells accumulated primarily in G(2) phase. In contrast, treatment with a high
concentration of BNP1350 (IC(90)) resulted in S phase accumulation. The
concentration-associated cell cycle perturbation by BNP1350 was correlated with
different profiles of cell cycle-regulatory protein expression. When treated with
the low concentration of BNP1350, cyclin B/cdc2 protein expression was up
regulated, whereas with the high concentration, no significant change was
observed at 24 and 48 h. In addition, increased phosphorylation of a G(2)
checkpoint kinase chk1 was observed when cells were treated with a low
concentration of BNP1350, whereas only slight inhibition of chk1 activity was
found in the cells treated with the higher concentration. Altered chk1
phosphorylation after DNA damage appears to be associated with specific phases of
cell cycle arrest induced by BNP1350. Because A253 cells do not express the p53
protein, the drug-induced alterations of the G(2) checkpoint kinase chk1 are not
p53-dependent.
PMID- 10692485
TI - Specific regulation of RGS2 messenger RNA by angiotensin II in cultured vascular
smooth muscle cells.
AB - The effects of angiotensin II (Ang II) are mediated primarily by Ang II type 1
receptors, which in turn are coupled to heterotrimeric G proteins. After receptor
activation, the G(alpha) and G(betagamma) subunits dissociate, contributing to
the signaling cascades involving protein kinase C (PKC) activation. Regulators of
G protein signaling (RGS proteins) comprise a class of proteins that have been
shown to negatively regulate the G(alpha) subunit. We examined which RGS
sequences were expressed in vascular smooth muscle cells and which of these were
regulated by Ang II. Reverse transcription-polymerase chain reaction showed that
of 16 RGS sequences screened, six RGS transcripts (RGS2, 3, 10, 11, and 12 and
GAIP) were present. Northern blot analysis demonstrated that RGS3, 10, and 12 and
GAIP were not regulated by Ang II at the mRNA level. In contrast, RGS2 mRNA was
rapidly and dose dependently increased (395 +/- 24% peak, 45 min) by Ang II but
returned to baseline level by 6 to 8 h. Phorbol-12-myristate-13-acetate, a PKC
activator, robustly increased RGS2. This signal was attenuated by the PKC
inhibitor GF 109203X (50 +/- 4%) and by phorbol-12, 13-dibutyrate-mediated down
regulation of PKC (48 +/- 13%). Tyrosine kinase inhibition and calcium
deprivation did not affect the up-regulation of RGS2 mRNA after Ang II
stimulation. Actinomycin D treatment inhibited both Ang II- and phorbol-12
myristate-13-acetate-stimulated RGS2 up-regulation, suggesting activation of
transcription by these agonists. The stability of RGS2 mRNA did not appear to be
affected by Ang II. Thus, RGS2 is a likely candidate for negative regulation of
the G proteins coupled to the Ang II type 1 receptor in vascular smooth muscle
cells. Regulation of this protein may be of critical importance in modulating the
role of Ang II in vascular disease.
PMID- 10692486
TI - Substrate-dependent regulation of human arylamine N-acetyltransferase-1 in
cultured cells.
AB - Arylamine N-acetyltransferase-1 (NAT1) is a polymorphically expressed enzyme that
is widely distributed throughout the body. In the present study, we provide
evidence for substrate-dependent regulation of this enzyme. Human peripheral
blood mononuclear cells cultured in medium supplemented with p-aminobenzoic acid
(PABA; 6 microM) for 24 h showed a significant decrease (50-80%) in NAT1
activity. The loss of activity was concentration-dependent (EC(50) approximately
2 microM) and selective because PABA had no effect on the activity of
constitutively expressed lactate dehydrogenase or aspartate aminotransferase.
PABA also induced down-regulation of NAT1 activity in several human cell lines
grown at confluence. Substrate-dependent down-regulation was not restricted to
PABA. Addition of other NAT1 substrates, such as p-aminosalicylic acid, ethyl-p
aminobenzoate, or p-aminophenol to peripheral blood mononuclear cells in culture
also resulted in significant (P <.05) decreases in NAT1 activity. However,
addition of the NAT2-selective substrates sulfamethazine, dapsone, or
procainamide did not alter NAT1 activity. Western blot analysis using a NAT1
specific antibody showed that the loss of NAT1 activity was associated with a
parallel reduction in the amount of NAT1 protein (r(2) = 0.95). Arylamines that
did not decrease NAT1 activity did not alter NAT1 protein levels.
Semiquantitative reverse transcriptase polymerase chain reaction of mRNA isolated
from treated and untreated cells revealed no effect of PABA on NAT1 mRNA levels.
We conclude that NAT1 can be down-regulated by arylamines that are themselves
NAT1 substrates. Because NAT1 is involved in the detoxification/activation of
various drugs and carcinogens, substrate-dependent regulation may have important
consequences with regard to drug toxicity and cancer risk.
PMID- 10692487
TI - A single glycine residue at the entrance to the first membrane-spanning domain of
the gamma-aminobutyric acid type A receptor beta(2) subunit affects allosteric
sensitivity to GABA and anesthetics.
AB - Site-directed mutagenesis of the gamma-aminobutyric acid type A (GABA(A))
receptor beta(2) subunit has demonstrated that conversion of a conserved glycine
residue located at the entrance to the first transmembrane domain into the
homologous rho(1) residue phenylalanine alters the modulating effects of four
different i.v. anesthetics: pentobarbital, alphaxalone, etomidate, and propofol.
Using the baculovirus expression system in Spodoptera frugiperda 9 cells,
anesthetic-induced enhancement of [(3)H]muscimol and [(3)H]flunitrazepam binding
in receptors containing the beta(2)(G219F) point mutation displayed a
significantly reduced efficacy in modulation by all four i.v. anesthetics tested.
Furthermore, GABA(A) receptors containing the alpha(1)(G223F) point mutation also
significantly decreased the maximal effect of etomidate- and propofol-induced
enhancement of ligand binding. Conversely, the homologous point mutation in
rho(1) receptors (F261G) changed the i.v. anesthetic-insensitive receptor to
confer anesthetic modulation of [(3)H]muscimol binding. Consistent with the
binding, functional analysis of pentobarbital-enhanced GABA currents recorded
with whole-cell patch clamp demonstrated the beta(2)(G219F) subunit mutation
eliminated the potentiating effect of the anesthetic. Similarly, propofol
enhanced GABA currents were potentiated less in alpha(1)beta(2)(G219F)gamma(2)
receptors than in alpha(1)beta(2)gamma(2) receptors. Although ligand binding
displayed comparable K(D) values for muscimol among wild-type,
alpha(1)beta(2)gamma(2), and mutant receptors, patch-clamp recordings showed that
alpha(1)beta(2)(G219F)gamma(2) receptors had a significantly more potent response
to GABA than did alpha(1)beta(2)gamma(2) or alpha(1)(G223F)beta(2)gamma(2). The
alpha(1)beta(2)(G219F)gamma(2) receptors also were more sensitive to direct
channel activation by pentobarbital and propofol in the absence of GABA. These
results suggest that the first transmembrane glycine residue on the beta(2)
subunit may be important for conformational or allosteric interactions of channel
gating by both GABA and anesthetics.
PMID- 10692488
TI - Inhibition of c-myc expression in cells by targeting an RNA-protein interaction
using antisense oligonucleotides.
AB - Antisense oligodeoxynucleotides (ODNs) are designed to bind to and inhibit a
target mRNA. We used a novel approach for the design of ODNs to the c-myc mRNA
using protein binding sites as targets for ODN action. Our strategy was to
identify ODNs that could interfere with the coding region determinant-binding
protein (CRD-BP), a protein that binds to the CRD region of the c-myc mRNA. Using
an in vitro gel shift assay, we show that ODN molecules can occlude the CRD-BP
from the mRNA. The best ODN, CRD-ODN4, was able to inhibit RNA binding of the CRD
BP by 75%. This effect was sequence-specific and concentration dependent. K562
cells treated with a 2'-O-methyl derivative of CRD-ODN4 showed a concentration
dependent decrease in both c-myc mRNA and protein levels, with a maximal 65%
inhibition of protein expression at 200 nM CRD-ODN4. In contrast, a 2'-O-methyl
ODN derivative targeting the translation initiation codon (antimyc-aug) reduced c
myc protein but actually increased mRNA levels, an effect resulting at least
partly from stabilization of the c-myc mRNA. CRD-ODN4 treatment did not alter the
c-myc mRNA half-life. CRD-ODN4 was more effective in inhibiting K562 cell growth
than antimyc-aug, reducing cell number by approximately 70% after 48 h of
exposure to 750 nM. The correlation between ODN effects on RNA-protein
interactions in vitro and those observed in cells supports the hypothesis that
CRD-ODN4 inhibits the interaction between the CRD-BP and the c-myc mRNA and that
disrupting this RNA-protein interaction reduces c-myc expression in cells.
PMID- 10692489
TI - Functional inactivation of the nociceptin receptor by alanine substitution of
glutamine 286 at the C terminus of transmembrane segment VI: evidence from a site
directed mutagenesis study of the ORL1 receptor transmembrane-binding domain.
AB - A site-directed mutagenesis approach has been used to gain insight into the
molecular events whereby the heptadecapeptide nociceptin binds and activates the
opioid receptor-like 1 (ORL1) receptor, a G protein-coupled receptor. Alanine
mutation, in the human ORL1 receptor, of transmembrane amino acid residues that
are conserved in opioid receptors, Asp(130) and Tyr(131) in transmembrane segment
(TM) III, Phe(220) and Phe(224) in TM V, and Trp(276) in TM VI, yields mutant
receptors with reduced affinity, and proportionally decreased reactivity, toward
nociceptin. Least to most deleterious in this respect are Ala substitutions of
Phe(220) approximately W276A < Tyr(131) << Phe(224) = Asp(130). The dramatic
effects of the D130A mutation on nociceptin binding and activity are not reversed
in the D130N mutant, whereas those of the Y131A mutation are totally suppressed
in Y131F. This suggests that a negative charge at position 130, and a phenyl ring
at position 131 in TM III, are critical for occupancy and/or activation of the
receptor by nociceptin. Alanine replacement of glutamine 286, located at the C
terminus of TM VI, yields a mutant receptor that binds nociceptin with nearly the
same affinity as does the wild-type receptor (K(d) values of 0.13 and 0.22 nM,
respectively) but, unlike the latter, is unable to mediate nociceptin inhibition
of forskolin-induced cAMP synthesis in recombinant Chinese hamster ovary cells
(ED(50) > 10,000 nM compared with 0.8 nM at the wild-type receptor). In all
respects, this mutant receptor appears to be functionally inactive, indicating
that residue Gln(286) may play a pivotal role in ORL1 receptor-mediated
transduction of the nociceptin signal.
PMID- 10692490
TI - Effect of p53 status on sensitivity to platinum complexes in a human ovarian
cancer cell line.
AB - Wild-type p53 is frequently mutated in late-stage ovarian cancer and has been
proposed as a determinant of cisplatin chemosensitivity. We have therefore
established a human ovarian cancer cell line differing only in p53 status and
characterized its response after treatment with different platinum complexes. The
wild-type p53-expressing cell line A2780 was stably transfected with HPV-16 E6
(E6) or an empty vector (VC) as control. Parental A2780 and VC had similar
cisplatin sensitivities, whereas E6 was 3- to 4-fold more sensitive as measured
by sulforhodamine B and clonogenic assay. E6 was 2- to 3-fold more sensitive to
transplatin and the novel cisplatin analog ZD0473 than VC, whereas the trans
platinum analog JM335 was approximately equitoxic. Platinum uptake was similar
for all of the cell lines after cisplatin. The removal of platinum-DNA adducts,
as measured by atomic absorption spectroscopy, was reduced in E6 compared with VC
after cisplatin but similar after JM335. After 10 microM cisplatin, the G(1)
population (0-96 h) was reduced in E6 cells compared with VC, whereas the S phase
(8-48 h) and G(2) phase (48-96 h) were increased. Similar proportions of VC and
E6 cells died by apoptosis, as detected by annexin V binding, but more E6 cells
died by necrosis relative to VC. Our results suggest that the loss of functional
p53 can increase cisplatin cytotoxicity in A2780, with loss of G(1)/S checkpoint
control and decreased cisplatin-DNA adduct repair, but these effects can be
circumvented by the use of JM335, which forms different DNA-platinum adducts.
PMID- 10692491
TI - Hematotoxicity of the chinese herbal medicine Tripterygium wilfordii hook f in
CD34-positive human bone marrow cells.
AB - T2, a chloroform/methanol extract of the herb Tripterygium wilfordii Hook f, has
been used in China for the treatment of autoimmune and inflammatory diseases for
many years. Recent experimental evidence has confirmed that T2 has potent anti
inflammatory and immunosuppressive activity, and a United States Food and Drug
Administration-approved clinical trial is currently exploring the efficacy of T2
in the treatment of rheumatoid arthritis. Despite the potential therapeutic
benefits of T2, there is ample documentation that T2 is toxic, targeting, among
other things, the hematopoietic system, and its use has resulted in cases of
leukopenia, thrombocytopenia, and aplastic anemia. This investigation was
undertaken to characterize the in vitro effects of T2 on primary human CD34
positive (CD34+) bone marrow cells. Our results demonstrate that T2 has a potent
inhibitory effect on the clonogenic response of human bone marrow cells to
exogenously added hematopoietic growth factors. The inhibition of colony
formation by T2 is not the result of direct cytotoxicity or increased apoptosis
and indicates a functional suppression of hematopoiesis. Additional experiments
demonstrate that T2 also alters transcriptional regulation in bone marrow cells
by inhibiting nuclear factor-kappaB. This transcription factor is found in CD34+
bone marrow cells and has been recently shown to be a requirement for colony
formation. These results demonstrate that therapeutic concentrations of T2 exert
a significant hematotoxic effect by inhibiting growth factor response in CD34+
bone marrow cells and suggest that inhibition of nuclear factor-kappaB may play a
role in the blood dyscrasias encountered with the use of this drug.
PMID- 10692492
TI - Calcium-independent receptor for alpha-latrotoxin and neurexin 1alpha
[corrected] facilitate toxin-induced channel formation: evidence that channel
formation results from tethering of toxin to membrane.
AB - alpha-Latrotoxin binding to the calcium-independent receptor for alpha-latrotoxin
(CIRL-1), a putative G-protein-coupled receptor, stimulates secretion from
chromaffin and PC12 cells. Using patch clamp techniques and
microspectrofluorimetry, we demonstrate that the interaction of alpha-latrotoxin
with CIRL-1 produces a high conductance channel that permits increases in
cytosolic Ca(2+). alpha-Latrotoxin interaction with CIRL-1 transiently expressed
in bovine chromaffin cells produced a 400-pS channel, which rarely closed under
Ca(2+)-free conditions. The major effect of overexpressing CIRL-1 was to greatly
increase the sensitivity of chromaffin cells to channel formation by alpha
latrotoxin. alpha-Latrotoxin interaction with CIRL-1 transiently overexpressed in
non-neuronal human embryonic kidney 293 (HEK293) cells produced channels that
were nearly identical with those observed in chromaffin cells. Channel currents
were reduced by millimolar Ca(2+). At alpha-latrotoxin concentrations below 500
pM, channel formation occurred many seconds after binding of toxin to CIRL-1
indicating distinct steps in channel formation. In all cases there was a rapid,
sequential addition of channels once the first channel appeared. An analysis of
CIRL-1 mutants indicated that channel formation in HEK293 cells is unlikely to be
transduced by a G-protein-dependent mechanism. alpha-Latrotoxin interaction with
a fusion construct composed of the extracellular domain of CIRL-1 anchored to the
membrane by the transmembrane domain of vesicular stomatitis virus glycoprotein,
and with neurexin 1alpha, an alpha-latrotoxin receptor structurally unrelated to
CIRL-1, produced channels virtually identical with those observed with wild-type
CIRL-1. We propose that alpha-latrotoxin receptors recruit toxin to facilitate
its insertion across the membrane and that alpha-latrotoxin itself controls the
conductance properties of the channels it produces.
PMID- 10692493
TI - Effect of 6-aminonicotinamide and other protein synthesis inhibitors on formation
of platinum-DNA adducts and cisplatin sensitivity.
AB - The present study was undertaken to examine the mechanistic basis for the recent
observation that the pyridine nucleotide derivative 6-aminonicotinamide (6AN, NSC
21206) enhances the accumulation and resulting cytotoxicity of cisplatin in a
variety of tumor cell lines. When A549 lung cancer cells or K562 leukemia cells
were treated with 62.5 microM 6AN for 21 h and then pulse-labeled with
[(35)S]methionine for 1 h, increased labeling of five polypeptides, one of which
corresponded to a M(r) approximately 78,000 glucose-regulated protein (GRP78),
was observed. Two subsequent observations, however, suggested that up-regulation
of these polypeptides was unlikely to explain the interaction between 6AN and
cisplatin: 1) the concentration of 6AN required to induce GRP78 was 4-fold higher
than the dose required to sensitize cells to cisplatin; and 2) simultaneous
treatment of cells with 6AN and cycloheximide prevented the increase in GRP78 but
not the sensitizing effect of 6AN. On the contrary, treatment with the protein
synthesis inhibitors cycloheximide, anisomycin, or puromycin as well as prolonged
exposure to the RNA synthesis inhibitor actinomycin D mimicked the biochemical
modulating effects of 6AN on cisplatin action. Conversely, 6AN inhibited protein
synthesis, whereas 18 6AN analogs that failed to enhance Pt-DNA adducts and
cisplatin cytotoxicity failed to inhibit protein synthesis. These observations
are consistent with a model in which 6AN and other inhibitors of protein
synthesis act as modulating agents by increasing cisplatin accumulation, thereby
enhancing the formation of Pt-DNA adducts and subsequent cisplatin-induced cell
death.
PMID- 10692494
TI - Identification of threonine residues controlling the agonist-dependent
phosphorylation and desensitization of the rat A(3) adenosine receptor.
AB - Activation of the A(3) adenosine receptor (A(3)AR) contributes to the
cardioprotective, bronchoconstrictive, and hypotensive effects of adenosine.
Agonist occupation of the A(3)AR results in a rapid desensitization of receptor
function, which is associated with the phosphorylation of the receptor protein by
one or more members of the G protein-coupled receptor kinase family of protein
kinases. Although we demonstrated previously that phosphorylation of the C
terminal 14 amino acids of the rat A(3)AR is crucial for rapid desensitization to
occur, the identity of the critical phosphorylation sites has remained unknown.
Here, we demonstrate that the simultaneous mutation of Thr(307), Thr(318), and
Thr(319) to Ala residues dramatically reduces agonist-stimulated phosphorylation
and rapid desensitization of the rat A(3)AR. Individual mutation of each residue
demonstrated that Thr(318) and Thr(319) are the major sites of phosphorylation.
Phosphorylation at Thr(318) appeared to be necessary to observe phosphorylation
at Thr(319), but not vice versa. However, the replacement of Thr(318) with a
glutamate residue demonstrated that the simple addition of negative charge at
position 318 was not sufficient to rescue phosphorylation at position 319. In
addition, the mutation of two predicted palmitoylation-site cysteine residues
proximal to the regulatory domain resulted in the appearance of an agonist
independent basal phosphorylation. Therefore, G protein-coupled receptor kinase
mediated phosphorylation of the C-terminal tail of the A(3)AR in situ appears to
follow a sequential mechanism, perhaps involving receptor depalmitoylation, with
phosphorylation at Thr(318) being particularly important.
PMID- 10692495
TI - Subtype-specific kinetics of inhibitory adenosine receptor internalization are
determined by sensitivity to phosphorylation by G protein-coupled receptor
kinases.
AB - Despite coupling to the same class of inhibitory G proteins and binding the same
physiological ligand, the human A(1) and rat A(3) adenosine receptors (ARs)
desensitize at different rates in response to sustained agonist exposure. This is
due to the ability of the A(3)AR, but not the A(1)AR, to serve as a substrate for
rapid phosphorylation and desensitization by members of the G protein-coupled
receptor kinase (GRK) family. The aim of this study was to investigate whether
these differences were also manifested in their abilities to undergo agonist
dependent receptor internalization. For the first time, we report that A(3)ARs
internalize profoundly in response to short-term exposure to agonist but not
activators of second messenger-regulated kinases. The A(3)AR-selective antagonist
MRS1523 blocked both A(3)AR phosphorylation and internalization. Moreover, in
contrast to the A(1)AR, which internalized quite slowly (t(1/2) = 90 min),
A(3)ARs internalized rapidly (t(1/2) = 10 min) over a time frame that followed
the onset of receptor phosphorylation. A nonphosphorylated A(3)AR mutant failed
to internalize over a 60-min time course, suggesting that receptor
phosphorylation was essential for rapid A(3)AR internalization to occur. In
addition, fusion onto the A(1)AR of the A(3)AR C-terminal domain containing the
sites for phosphorylation by GRKs conferred rapid agonist-induced internalization
kinetics (t(1/2) = 10 min) on the resulting chimeric AR. In conclusion, these
data suggest that GRK-stimulated phosphorylation of threonine residues within the
C-terminal domain of the A(3)AR is obligatory to observe rapid agonist-mediated
internalization of the receptor.
PMID- 10692497
TI - Calmodulin increases the sensitivity of type 3 inositol-1,4, 5-trisphosphate
receptors to Ca(2+) inhibition in human bronchial mucosal cells.
AB - Inositol-1,4,5-trisphosphate (IP(3)) releases Ca(2+) from intracellular stores by
binding to its receptor (IP(3)R), a multigene family of Ca(2+)-release channels
consisting of IP(3)R1, IP(3)R2, and IP(3)R3. IP(3)R1 is stimulated by low
cytoplasmic Ca(2+) concentrations and inhibited by high concentrations.
Discrepant reports appeared about the effect of cytoplasmic Ca(2+) on IP(3)R3,
showing either a bell-shaped dependence or only a stimulatory phase with no
negative feedback by high Ca(2+) concentrations. We investigated how calmodulin
interfered with the feedback of cytosolic Ca(2+) on the unidirectional IP(3)
induced Ca(2+) release in permeabilized 16HBE14o- bronchial mucosal cells, where
IP(3)R3 represents 93% of the receptors at the mRNA level and 81% at the protein
level. Calmodulin inhibited the Ca(2+) release induced by 1.5 microM IP(3) with
an IC(50) value of 9 microM. This inhibition was absolutely dependent on the
presence of cytosolic Ca(2+). Ca(2+) inhibited the IP(3)R with an IC(50) value of
0.92 microM Ca(2+) in the absence of calmodulin and with an IC(50) value of 0.15
microM Ca(2+) in its presence. It is concluded that: 1) IP(3)R3 can be inhibited
by calmodulin, 2) IP(3)R3 is inhibited by high Ca(2+) concentrations, and 3)
calmodulin shifts the inhibitory part of the Ca(2+)-response curve toward lower
Ca(2+) concentrations.
PMID- 10692496
TI - RPR112378 and RPR115781: two representatives of a new family of microtubule
assembly inhibitors.
AB - A screening program aimed at the discovery of new antimicrotubule agents yielded
RPR112378 and RPR115781, two natural compounds extracted from the Indian plant
Ottelia alismoides. We report their isolation, structural determination, and
mechanisms of action. RPR112378 is an efficient inhibitor of tubulin
polymerization (IC(50) = 1.2 microM) and is able to disassemble preformed
microtubules. Regarding tubulin activity, RPR115781 is 5-fold less active than
RPR112378. Tubulin-RPR112378 complexes, when isolated by gel filtration, were
able to block further tubulin addition to growing microtubules, a mechanism that
accounts for the substoichiometric effect of the drug. RPR112378 was found to
prevent colchicine binding but not vinblastine binding to tubulin. Although
colchicine binding is known to induce an increase of tubulin GTPase activity, no
such increase was observed with RPR112378. We show that RPR112378 is a highly
cytotoxic compound and that RPR115781 is 10, 000-fold less active as an inhibitor
of KB cell growth. Part of the cytotoxicity of RPR112378 is probably caused by a
reaction of addition with sulfhydryl groups, an observation that has not been
made with RPR115781. In conclusion, these molecules represent a new class of
inhibitors of microtubule assembly with potential therapeutic value.
PMID- 10692498
TI - A steroid derivative with paclitaxel-like effects on tubulin polymerization.
AB - The endogenous estrogen metabolite 2-methoxyestradiol has modest antimitotic
activity that may result from a weak interaction at the colchicine binding site
of tubulin, but it nevertheless has in vivo antitumor activity. Synthetic efforts
to improve activity led to compounds that increased inhibitory effects on cell
growth, tubulin polymerization, and binding of colchicine to tubulin. This
earlier work was directed at modifications in the steroid A ring, which is
probably analogous to the colchicine tropolonic C ring. One of the most active
analogs prepared was 2-ethoxyestradiol (2EE). We report here that different
modifications in the steroid B ring of 2EE yield compounds with two apparently
distinct modes of action. Simple expansion of the B ring to seven members
resulted in a compound comparable to 2EE in its ability to inhibit tubulin
polymerization and colchicine binding to tubulin. Acetylation of the hydroxyl
groups in this analog and in 2EE essentially abolished these inhibitory
properties. The introduction of a ketone functionality at C6, together with
acetylation of the hydroxyls at positions 3 and 17, produced a compound with
activity similar to that of paclitaxel, in that the agent enhanced tubulin
polymerization into polymers that were partially stable at 0 degrees C. The
acetyl group at C17, but not that at C3, was essential for this paclitaxel-like
activity.
PMID- 10692499
TI - Cloned human aquaporin-1 is a cyclic GMP-gated ion channel.
AB - Aquaporin-1 (AQP1) is a member of the membrane intrinsic protein (MIP) gene
family and is known to provide pathways for water flux across cell membranes. We
show here that cloned human AQP1 not only mediates water flux but also serves as
a cGMP-gated ion channel. Two-electrode voltage-clamp analyses showed consistent
activation of an ionic conductance in wild-type AQP1-expressing oocytes after the
direct injection of cGMP (50 nl of 100 mM). Current activation was not observed
in control (water-injected) oocytes or in AQP5-expressing oocytes with osmotic
water permeabilities equivalent to those seen with AQP1. Patch-clamp recordings
revealed large conductance channels (150 pS in K(+) saline) in excised patches
from AQP1-expressing oocytes after the application of cGMP to the internal side.
Amino acid sequence alignments between AQP1 and sensory cyclic-nucleotide-gated
channels showed similarities between the cyclic-nucleotide-gated binding domain
and the AQP1 carboxyl terminus that were not present in AQP5. Competitive
radioligand-binding assays with [(3)H]cGMP demonstrated specific binding (K(D) =
0.2 microM) in AQP1-expressing Sf9 cells but not in controls. These results
indicate that AQP1 channels have the capacity to participate in ionic signaling
after the activation of cGMP second-messenger pathways.
PMID- 10692500
TI - Catechol-O-methyltransferase inhibition attenuates levodopa toxicity in
mesencephalic dopamine neurons.
AB - Inhibition of catechol-O-methyltransferase (COMT; EC 2.1.1.6) is a new
therapeutic strategy in the treatment of Parkinson's disease. However, nothing is
known about the effects of COMT inhibition on levodopa (L-dopa)-induced toxicity
in dopamine (DA) neurons. Therefore we evaluated the effects of the selective
COMT inhibitors Ro 41-0960, OR-486, and tolcapone alone and in combination with L
dopa in primary mesencephalic cultures from rat. Neither COMT inhibitor affected
the growth of tyrosine hydroxylase immunoreactive (THir) cells with
concentrations up to 10 microM when studied alone. However, Ro 41-0960 reduced
the L-dopa-induced THir cell loss after 24 h in a dose-dependent manner, shifting
the TD(50) value from 21 microM in the absence to 71 microM in the presence of 1
microM Ro 41-0960 (P <.01) without affecting survival of non-DA neurons. OR-486
and the clinically used COMT inhibitor tolcapone showed similar effects. In
contrast, toxicity induced by D-dopa was not altered by COMT inhibitors.
Furthermore, the primary metabolite of L-dopa formed by COMT, 3-O-methyldopa, and
the methyl group donor S-adenosyl-L-methionine used by COMT did not alter THir
neuron survival and L-dopa-induced toxicity, respectively, with concentrations up
to 100 microM. These data demonstrate that COMT inhibition attenuates L-dopa
toxicity toward DA neurons in vitro, but probably not by preventing 3-O
methyldopa production or cellular S-adenosyl-L-methionine depletion.
PMID- 10692501
TI - myo-inositol 1,4,6-trisphosphorothioate and myo-inositol 1,3, 6
trisphosphorothioate: partial agonists with very low intrinsic activity at the
platelet myo-inositol 1,4,5-trisphosphate receptor.
AB - Racemic mixtures and enantiomerically pure D-isomers of both myo-inositol 1,3,6
trisphosphorothioate [Ins(1,3,6)PS(3)] and myo-inositol 1,4,6
trisphosphorothioate [Ins(1,4,6)PS(3)], prepared by total synthesis, were
examined in Ca(2+) flux and binding assays. Both D-Ins(1,3,6)PS(3) and D
Ins(1,4,6)PS(3) were shown to be low intrinsic activity partial agonists at the
platelet myo-inositol 1,4, 5-trisphosphate [Ins(1,4,5)P(3)] receptor, releasing
less than 20% of the Ins(1,4,5)P(3)-sensitive Ca(2+) store. D-Ins(1,4,6)PS(3)
displaced specifically bound [(3)H]Ins(1,4,5)P(3) from rat cerebellar membranes,
although displacement was some 34-fold weaker than by D-Ins(1,4,5)P(3). D
Ins(1,4,6)PS(3) displaced [(3)H]Ins(1,4, 5)P(3) from cerebellar membranes with
roughly twice the affinity of DL-Ins(1,4,6)PS(3) (IC(50) value = 1.4 +/- 0.35
microM compared with 2.15 +/- 0.13 microM), whereas D-Ins(1,3,6)PS(3) displaced
[(3)H]Ins(1,4,5)P(3) with roughly twice the affinity of DL-Ins(1,3, 6)PS(3)
(IC(50) value = 17.5 +/- 5.8 microM compared with 34 +/- 10 microM), confirming
that the activity of both these phosphorothioates resides in their D-enantiomers.
Increasing concentrations of either D-Ins(1,3,6)PS(3) or D-Ins(1,4,6)PS(3) were
able to partially antagonize Ca(2+) release induced by submaximal concentrations
of Ins(1,4,5)P(3), an inhibition that could be overcome by increasing the
concentration of Ins(1,4,5)P(3), suggesting competition for binding at the
Ins(1,4,5)P(3)-R. The only low-efficacy partial agonists at the Ins(1,4,5)P(3)-R
discovered to date have been phosphorothioates; the novel D-Ins(1,3,6)PS(3) and D
Ins(1,4,6)PS(3) can now be added to this small group of analogs. However, D
Ins(1,4,6)PS(3) has a relatively high affinity for the Ins(1,4,5)P(3)-R but
maintains the lowest efficacy of all the partial agonists thus far identified. As
such, it may be a useful tool for pharmacological intervention in the
polyphosphoinositide pathway and an important lead compound for the development
of further Ins(1,4,5)P(3)-R antagonists.
PMID- 10692502
TI - Potency of ligands correlates with affinity measured against agonist and inverse
agonists but not against neutral ligand in constitutively active chemokine
receptor.
AB - ORF-74, a 7TM receptor oncogene encoded by human herpes virus 8, shows 50%
constitutive activity in stimulating phosphatidylinositol turnover and binds a
large variety of CXC chemokines. These endogenous ligands cover a full spectrum
of pharmacological properties with growth-related oncogene (GRO)-alpha and -gamma
functioning as full agonists; GRObeta as a partial agonist; interleukin (IL)-8,
neutrophil-activating peptide (NAP)-2, and epithelial cell-derived activating
peptide (ENA)-78 as neutral ligands; granulocyte colony-stimulating factor (GCP)
2 as a partial inverse agonist; and interferon-gamma inducible protein (IP)-10
and stromal cell-derived factor (SDF)-1alpha as full inverse agonists. The
affinity for the agonists was independent of whether it was determined in
competition binding against the agonist (125)I-GROalpha, against the inverse
agonist (125)I-IP-10, or against the neutral ligand (125)I-IL-8. Similarly, the
affinities of the inverse agonists were within 1 order of magnitude independent
of the choice of radioligand. In contrast, the neutral ligands IL-8, NAP-2, and
ENA-78, which all displaced (125)I-IL-8 with single-digit nanomolar affinity
showed up to 1000-fold lower affinity against both the radioactive agonist and
against the radioactive inverse agonist. A close correlation was observed between
the EC(50) values for the ligands and their IC(50) values measured against either
radioactive agonist or radioactive inverse agonist, but a poor correlation was
found to the IC(50) value measured against the neutral ligand. It is concluded
that in ORF-74, ligands compete for binding more according to pharmacological
property than to structural homology and that both agonists and inverse agonists,
in contrast to neutral ligands, apparently bind with high affinity either to a
common conformation of the receptor or to readily interconvertible states, not
available for the neutral ligands.
PMID- 10692503
TI - Transcriptional induction of heme oxygenase-1 gene expression by okadaic acid in
primary rat hepatocyte cultures.
AB - Heme oxygenase (HO) catalyzes the rate-limiting enzymatic step of heme
degradation and regulates the cellular heme content. The gene expression of the
inducible isoform of HO, HO-1, is up-regulated in response to various agents
causing oxidative stress. To investigate the regulatory role of protein
phosphatases in the hepatic regulation of HO-1 gene expression, primary cultures
of rat hepatocytes were treated with okadaic acid (OA), which specifically
inhibits the serine threonine protein phosphatases 1 and 2A. Both protein
synthesis and mRNA expression of HO-1 were induced by OA in cultured hepatocytes,
but not in cultured tissue macrophages of rat liver. The HO-1 mRNA induction by
OA occurred in a time- and concentration-dependent manner. Simultaneous treatment
with OA plus dibutyryl cAMP caused a synergistic up-regulation of steady-state
levels of HO-1 mRNA, and the specific protein kinase A inhibitor KT5720 markedly
reduced the OA-dependent HO-1 mRNA induction. In contrast, the dibutyryl cAMP
dependent induction of the phosphoenolpyruvate carboxykinase mRNA expression and
enzyme activity was inhibited by simultaneous treatment with OA in hepatocytes.
The induction of the HO-1 gene expression by OA was transcriptional as determined
by studies with actinomycin D, nuclear run-off assay, and measurement of the half
life of HO-1 mRNA. Luciferase reporter constructs containing DNA sequences of the
rat HO-1 promoter 5'-flanking region were up-regulated by OA in transiently
transfected hepatocytes. Mutation of the cAMP response element/activator protein
1 (-665/-654) site obliterated the OA-dependent induction, suggesting that this
element is involved in the transcriptional induction of the rat HO-1 gene by OA.
PMID- 10692504
TI - The human glutathione transferase P1-1 specific inhibitor TER 117 designed for
overcoming cytostatic-drug resistance is also a strong inhibitor of glyoxalase I.
AB - gamma-L-Glutamyl-S-(benzyl)-L-cysteinyl-R-(-)-phenylglycine (TER 117) has
previously been developed for selective inhibition of human glutathione S
transferase P1-1 (GST P1-1) based on the postulated contribution of this
isoenzyme to the development of drug resistance in cancer cells. In the present
investigation, the inhibitory effect of TER 117 on the human glyoxalase system
was studied. Although designed as an inhibitor specific for GST P1-1, TER 117
also competitively inhibits glyoxalase I (K(I) = 0.56 microM). In contrast, no
inhibition of glyoxalase II was detected. Reduced glyoxalase activity is expected
to raise intracellular levels of toxic 2-oxoaldehydes otherwise eliminated by
glyoxalase I. The resulting toxicity would accompany the potentiation of
cytostatic drugs, caused by inhibition of the detoxication effected by GST P1-1.
TER 117 was designed for efficient inhibition of the most abundant form GST P1
1/Ile105. Therefore, the inhibitory effect of TER 117 on a second allelic variant
GST P1-1/Val105 was also studied. TER 117 was shown to competitively inhibit both
GST P1-1 variants. The apparent K(I) values at glutathione concentrations
relevant to the intracellular milieu were in the micromolar range for both enzyme
forms. Extrapolation to free enzyme produced K(I) values of approximately 0.1
microM for both isoenzymes, reflecting the high affinity of GST P1-1 for the
inhibitor. Thus, the allelic variation in position 105 of GST P1-1 does not
affect the inhibitory potency of TER 117. The inhibitory effects of TER 117 on
GST P1-1 and glyoxalase I activities may act in synergy in the cell and improve
the effectiveness of chemotherapy.
PMID- 10692505
TI - Functional importance of transmembrane helix 6 Trp(279) and exoloop 3 Val(299) of
rat gonadotropin-releasing hormone receptor.
AB - Previous studies have established that the interaction of gonadotropin-releasing
hormone (GnRH) with its receptor (GnRHR) would require partial entry of the N-
and C-terminal regions of ligand into the transmembrane core. The functional
significance of the conserved aromatic residue Trp(279) present in the
transmembrane helix 6, and Val(299) located in exoloop 3 of the rat GnRHR was
investigated by mutagenesis followed by expression in Chinese hamster ovary-K1
cells. Compared with wild-type, substitution of Trp(279) with Ser or Arg resulted
in a marked reduction or total abolition, respectively, of ligand binding and, in
both cases, abrogation of GnRH-induced inositol phosphate production. A total
absence of functionality was observed when Val(299) was simply replaced with Ala.
Mention should be made that an expression of all mutated and wild-type receptor
proteins was observed. Interestingly, the double mutant
[Trp(279)Arg/Val(299)Ala]GnRHR restored B(max) to wild type (504 +/- 43 versus
541 +/- 41 fmol/mg protein), but with a diminished affinity (4.95 +/- 1.05 versus
0.94 +/- 0.35 nM), and GnRH failed to induce inositol phosphate. No influence of
the mutations was seen on internalization of the receptor. The three-dimensional
model of GnRH binding to the rat GnRHR was built predicting that Trp(279) is
buried at 20 A in the transmembrane core of the receptor, directly in contact
with Trp(3) of GnRH. In contrast, Val(299) is located in a region that cannot be
precisely defined at the extracellular end of transmembrane helix 7. Although
models cannot provide any clue concerning the observed interactivity between the
two distal residues, altogether these data reveal the functional importance of
both GnRHR Trp(279) and Val(299) and suggest that Trp(279), interacting with GnRH
Trp(3), represents the bottom of the binding pocket.
PMID- 10692506
TI - Transport function and hepatocellular localization of mrp6 in rat liver.
AB - The multidrug resistance-associated proteins (Mrps) constitute a family of
cellular export pumps of the ATP-binding cassette transporter superfamily and
play an important role in hepatobiliary excretion. We investigated the transport
function and subcellular localization of mrp6, a novel member of the mrp family,
in rat liver. Transport studies in vesicles isolated from mrp6 expressing Sf9
cells identified the anionic cyclopentapeptide and endothelin receptor antagonist
BQ-123 as a substrate of mrp6 (K(m) approximately 17 microM). Besides BQ-123,
which is also a substrate of mrp2 (K(m) approximately 124 microM), no other
common substrates were found for mrp2, mrp6, and the canalicular bile salt export
pump Bsep. The cyclic peptides endothelin I and Arg(8)-vasopressin were
transported by mrp2 but not by mrp6. Using a polyclonal antiserum raised against
a C-terminal peptide, mrp6 was found to be localized at the lateral and, to a
lesser extent, at the canalicular plasma membrane of hepatocytes. The limited
overlap of the substrate specificity with the canalicular export pumps mrp2 and
Bsep indicates that mrp6 does not play a major role in canalicular organic anion
excretion. However, its dual localization at the lateral and canalicular plasma
membrane suggests that mrp6 might fulfill a "housekeeping" transport function
involved in the regulation of paracellular and/or transcellular solute movement
from blood into bile.
PMID- 10692507
TI - 5-Iodo-A-85380, an alpha4beta2 subtype-selective ligand for nicotinic
acetylcholine receptors.
AB - In an effort to develop selective radioligands for in vivo imaging of neuronal
nicotinic acetylcholine receptors (nAChRs), we synthesized 5-iodo-3-(2(S)
azetidinylmethoxy)pyridine (5-iodo-A-85380) and labeled it with (125)I and
(123)I. Here we present the results of experiments characterizing this
radioiodinated ligand in vitro. The affinity of 5-[(125)I]iodo-A-85380 for
alpha4beta2 nAChRs in rat and human brain is defined by K(d) values of 10 and 12
pM, respectively, similar to that of epibatidine (8 pM). In contrast to
epibatidine, however, 5-iodo-A-85380 is more selective in binding to the
alpha4beta2 subtype than to other nAChR subtypes. In rat adrenal glands, 5-iodo-A
85380 binds to nAChRs containing alpha3 and beta4 subunits with 1/1000th the
affinity of epibatidine, and exhibits 1/60th and 1/190th the affinity of
epibatidine at alpha7 and muscle-type nAChRs, respectively. Moreover, unlike
epibatidine and cytisine, 5-[(125)I]iodo-A-85380 shows no binding in any brain
regions in mice homozygous for a mutation in the beta2 subunit of nAChRs. Binding
of 5-[(125)I]iodo-A-85380 in rat brain is reversible, and is characterized by
high specificity and a slow rate of dissociation of the receptor-ligand complex
(t(1/2) for dissociation approximately 2 h). These properties, along with other
features observed previously in in vivo experiments (low toxicity, rapid
penetration of the blood-brain barrier, and a high ratio of specific to
nonspecific binding), suggest that this compound, labeled with (125)I or (123)I,
is superior to other radioligands available for in vitro and in vivo studies of
alpha4beta2 nAChRs, respectively.
PMID- 10692508
TI - Adrenomedullin as a renal regulator peptide.
PMID- 10692509
TI - Connective tissue growth factor: just another factor in renal fibrosis?
PMID- 10692510
TI - Cocaine use and kidney damage.
PMID- 10692511
TI - Multiple myeloma and renal failure.
PMID- 10692512
TI - At which stage of renal failure should dialysis be started?
PMID- 10692513
TI - Comparison of survival on CAPD and haemodialysis: statistical pitfalls.
PMID- 10692514
TI - Renal failure following cardiac transplantation.
PMID- 10692515
TI - Should renal transplantation be offered to older patients?
PMID- 10692516
TI - Tubular cell damage in acute renal failure-apoptosis, necrosis, or both.
PMID- 10692517
TI - BK-virus nephropathy in renal transplants-tubular necrosis, MHC-class II
expression and rejection in a puzzling game.
AB - We review BK-virus nephropathy (BKN) as a new complication that increasingly
affects renal allografts and causes dysfunction. Since starting in 1996, we have
seen 11 cases. Currently, the prevalence of BKN is 3% in our graft biopsies. The
diagnosis can only be made histologically. The virus affects tubular epithelial
cells that show characteristic intranuclear inclusion bodies. The major reason
for impaired graft function and a possible way for viral particles to gain access
to the blood via peritubular capillaries is necrosis of infected epithelial
cells. BK-virus DNA in the plasma, which can be detected by PCR, is closely
associated with nephropathy. BK-virus does not stimulate tubular MHC-class II
expression as judged by immunofluorescence double labelling. The inflammatory
response is inconsistent and the frequency of rejection episodes is not increased
during disease. Clinical manifestation of viral nephropathy evolves in several
stages. (i) Initial, asymptomatic and reversible activation of the virus, judged
by the presence of inclusion bearing cells in the urine. (ii) High dose
immunosuppressive drug regimens, often including tacrolimus. (iii) Tubular injury
and viraemia as additional promoting conditions. BKN nephropathy was associated
with graft loss in 45% of our patients. The remaining patients with persistent
viral nephropathy showed renal dysfunction (serum creatinine levels on average
150% above baseline readings). Currently, no established antiviral therapy is
available. We discuss attempts to lower immunosuppression as a means to control
viral replication. We propose a diagnostic algorithm for screening and monitoring
the disease.
PMID- 10692518
TI - In the queue for a cadaver donor kidney transplant: new rules and concepts in the
Eurotransplant International Foundation.
PMID- 10692519
TI - CyA and OxLDL cause endothelial dysfunction in isolated arteries through
endothelin-mediated stimulation of O(2)(-) formation.
AB - BACKGROUND: Cyclosporin A (CyA) and oxidized low-density lipoprotein (OxLDL)
cause endothelial dysfunction, partly through stimulation of O(2)(-) formation
(which can inactivate nitric oxide). We investigated whether CyA and OxLDL
potentiate their influence on oxidative stress, whether endothelin (ET) is a
mediator of CyA- and OxLDL-induced O(2)(-) formation, and whether enhanced
oxidative stress results in further attenuation of endothelium-dependent
vasodilation. METHODS AND RESULTS: Human LDL was oxidized by Cu(++). O(2)(-)
formation of isolated rat aortic rings was measured using a chemiluminescence
assay. Incubation (60 min) of aortic rings with CyA (10 ng-10 microg/ml) or with
OxLDL (300 microg/ml) caused a significant, dosedependent increase of the basal
O(2)(-) formation. Pretreatment of the aortic rings with CyA (10 ng/ml) further
enhanced the OxLDL-induced O(2)(-) formation by factor 1.9. The enhancement of
the OxLDL-induced stimulation of O(2)(-) formation by CyA could be completely
blocked by BQ123, a selective endothelin-1 (ET-1) receptor antagonist. Likewise,
exogenously applied ET-1 (1 nM) potentiated the OxLDL-induced O(2)(-) formation
by factor 1.8. Endothelium-dependent dilation was measured in isolated rings of
rabbit aorta superfused with physiological salt solution in an organ bath.
Incubation of the aortic rings with CyA (10 microg/ml, 60 min) or with OxLDL (300
microg/ml, 60 min) alone did not attenuate endothelium-dependent dilations.
However, coincubation of the aortic rings with CyA+OxLDL in the presence of
diethyl-dithio-carbamate, an inhibitor of the endogenous superoxide dismutase,
caused a 60% inhibition of acetylcholine-induced dilator responses. CONCLUSIONS:
Coincubation of isolated aortic rings with CyA and OxLDL causes a potent
enhancement of vascular O(2)(-) formation. ET-1 seems to be mediator of the CyA
induced O(2)(-) formation. Enhanced oxidative stress results in further
attenuation of endothelium dependent vasodilation.
PMID- 10692520
TI - Aminoguanidine ameliorates changes in the IGF system in experimental diabetic
nephropathy.
AB - BACKGROUND: Formation of advanced glycation end-products (AGEs) has been
implicated in the development of diabetic complications. As well as causing
changes in structural proteins, AGEs may also alter gene expression of growth
factors in vitro. The insulin-like growth factor (IGF) system, including IGF-I
and modulatory IGF binding proteins (IGFBPs), is dysregulated during the
development of diabetic nephropathy. METHODS: Quantitative in situ hybridization
histochemistry and immunohistochemistry were used to determine the effects of
aminoguanidine, an inhibitor of AGE formation, on gene expression of IGF-I and
IGFBPs in kidneys of long-term (8 months duration) streptozotocin-diabetic rats.
RESULTS: Diabetes was associated with increased renal expression of IGFBP-1 mRNA
(diabetes 824+/-236 vs control 264+/-76 arbitrary units, P<0.01) and decreased
expression of mRNAs for IGF-I (diabetes 39+/-7 vs control 185+/-23 arbitrary
units, P<0.001) and IGFBP-4 (diabetes 139+/-25 vs control 383+/-54 arbitrary
units, P<0.001). Aminoguanidine treatment inhibited the effects of diabetes on
renal expression of mRNA for IGF-I, IGFBP-1 and IGFBP-4. The changes in IGF-I and
IGFBP-1 mRNA levels were reflected in altered peptide levels. In diabetic
kidneys, IGFBP-5 mRNA levels were slightly decreased to 75% of control levels
(P<0.01); aminoguanidine had no effect on IGFBP-5 mRNA levels. CONCLUSIONS: These
results suggest that amelioration of changes in the renal IGF system by
aminoguanidine may contribute to the renoprotective effects of the latter, which
have been previously shown to inhibit structural and functional aspects of
diabetic nephropathy in the rat.
PMID- 10692521
TI - Glycoxidative modification of AA amyloid deposits in renal tissue.
AB - BACKGROUND: N(epsilon)-carboxymethyllysine (CML) is a product of the oxidative
modification of glycated proteins, which damages proteins with ageing, diabetes,
uraemia and Alzheimer's disease. In contrast, pyrraline is one of the advanced
glycation end products, which is independent of oxidative processes. CML has been
identified in beta-amyloid of Alzheimer's disease and beta(2)-microglobulin
associated amyloid. We investigated whether CML and pyrraline are formed in AA
and AL amyloid of the kidney. METHOD: Renal specimens from 19 cases of AA
amyloidosis and 14 cases of AL amyloidosis were investigated for
immunolocalization of CML, pyrraline, collagen type IV and laminin in amyloid
deposits. Renal biopsies of 10 age-matched cases with thin basement membrane
disease and normal renal function were used as controls. The fractional areas of
amyloid, CML, laminin and collagen IV in glomeruli and interstitium (%amyloid,
%CML, %laminin and %collagen, respectively) were calculated using the point
counting method. The correlation between these parameters was evaluated using
Spearman's rank correlation test. RESULTS: CML colocalized with AA amyloid, but
not AL amyloid, except in two cases of the latter with a long history of
nephropathy exceeding 14 years. In contrast, pyrraline was not observed in either
type of amyloid. Mean %CML in AA amyloid was significantly higher than %collagen
and %laminin in glomeruli and interstitium, indicating that AA amyloid is
modified by CML independent of colocalized extracellular matrix. %CML
significantly correlated with %amyloid both in glomeruli and interstitium in AA
amyloidosis. AL amyloid cases with a long history of nephropathy showed positive
staining for CML in glomeruli and interstitium but no staining for collagen IV
and laminin in amyloid deposits. CONCLUSION: CML modification may occur in
amyloid deposits of AA amyloidosis, independent of extracellular matrix
components. Glycoxidative modification may have a functional link to AA amyloid
deposition in renal tissues.
PMID- 10692522
TI - Citrate determines calcium oxalate crystallization kinetics and crystal
morphology-studies in the presence of Tamm-Horsfall protein of a healthy subject
and a severely recurrent calcium stone former.
AB - BACKGROUND: The aim of this study was to measure the effects of normal (nTHP) and
abnormal stone former Tamm-Horsfall protein (SF-THP) on calcium oxalate (CaOx)
nucleation and aggregation as well as on crystal morphology, in presence or
absence of citrate. METHODS: Nucleation and aggregation of CaOx crystals from a
supersaturated, stirred solution (200 mM NaCl, 10 mM Na-acetate, pH 5.70, 5 mM Ca
and 0.5 mM Ox) were studied by spectrophotometric time-course measurements of OD
at 620 nm (OD(620)). Measured parameters were induction time t(I) (time to induce
formation of detectable particles), S(N), (slope of increase of OD(620), mainly
due to crystal nucleation), and S(A), (slope of decrease of OD(620) after
equilibrium has been reached, due to crystal aggregation). Effects of citrate,
nTHP and SF-THP on these parameters were measured, and scanning electron
microscopy (SEM) was performed. RESULTS: At 1.5, 2.5 and 3.5 mM, citrate
increased t(I) and inhibited crystal nucleation (by 78-87%) as well as
aggregation (by 63-70%), and smaller CaOx crystals (length/width ratio 1.7+/-0.1)
than under standard conditions (length/width 3.9+/-0.5) were visible (P<0.001).
Normal THP at 30 and 40 mg/l inhibited crystal nucleation and, more strongly,
aggregation (inhibition 76-81%). SEM revealed a decrease in length/width ratio to
2.6+/-0.4 (P=0.051 vs standard conditions) and less aggregation than without
nTHP. At all concentrations tested, SF-THP reduced t(I) (P=0.0001 vs standard
conditions) and promoted aggregation (inhibition -48 to -33%); crystals were
elongated with a length/width ratio of 4.3+/-0.6 (P<0. 05 vs nTHP). When
simultaneously present with nTHP, citrate enhanced the inhibitory effects of
nTHP, producing the smallest (length/width 1.5+/-0.1) and least aggregated
crystals. Finally, 3.5 mM citrate turned promotory SF-THP into a crystallization
inhibitor with abundant small and clustered, but not aggregated crystals.
CONCLUSION: Citrate appears to be the main determinant of CaOx crystallization
rates and crystal morphology in the presence of nTHP as well as SF-THP. Its
effects appear to predominate over those of THP, since even promotory SF-THP is
turned into a crystallization inhibitor in the presence of citrate. This re
emphasizes at a morphological level what has been concluded from functional as
well from clinical studies, namely that citrate is needed in urine at equimolar
concentrations to calcium in order to prevent the formation of large crystal
aggregates in presence of abnormal THP.
PMID- 10692523
TI - Vitamin D metabolite requirements in dialysed children receiving recombinant
human growth hormone.
AB - BACKGROUND: The aim of the study was to assess the requirement of active vitamin
D in dialysed children during treatment with recombinant human growth hormone
(rhGH). METHODS: Twenty-six children (aged 5-15 years) were treated with rhGH for
6 months. The serum concentration of parathyroid hormone (PTH), alkaline
phosphatase (AP), and calcium and phosphorus were measured in two groups of
patients studied in the years 1994-1995 (group I) and 1995-1998 (group II)
respectively. Group I received a constant dose of alfacalcidol that was
sufficient to keep PTH below 200 pg/ml before rhGH treatment began. The serum PTH
level was checked every 3 months. Alfacalcidol was administered to group II
according to serum PTH levels checked on a monthly basis. RESULTS: In group I the
PTH level increased after 3 and 6 months of rhGH treatment from mean level 73+/
60; 155+/-156 and 344+/-249 pg/ml respectively; P<0.05. AP activity increased
after 6 months of treatment from 206+/-99 to 325+/-124 U/l respectively; P<0.01.
The calcium level decreased from baseline after 3 months of treatment from 2.36+/
0.21 to 2.17+/-0.12 mmol/l respectively; P<0.05. In group II AP activity
increased after 3 and 6 months of treatment from 272+/-169 to 332+/-192 and 404.
9+/-219.8 U/l respectively; P<0.01. The mean level of phosphorus decreased after
6 months from 2.15+/-0.28 to 1.70+/-0.39 mmol/l respectively; P<0.01. In group II
the mean dose of alfacalcidol increased by 60.9%. CONCLUSIONS: In children with
end-stage renal failure, higher doses of vitamin D are needed during rhGH
treatment. During rhGH treatment, frequent control of serum PTH level is
necessary.
PMID- 10692524
TI - Effects of dialyser and dialysate on the acute phase reaction in clinical
bicarbonate dialysis.
AB - BACKGROUND: In chronic haemodialysis (HD), morbidity may result from repetitive
induction of the acute phase response, caused by a bioincompatible dialysis
membrane and/or contaminated dialysate. In the present study, cytokine release
(interleukin-6, IL-6) and subsequent production of acute phase proteins (C
reactive protein, CRP and secretory phospholipase A(2), sPLA(2)) were assessed to
investigate whether the HD-induced acute phase reaction depends mainly on the
type of membrane or on the sterility of the dialysate. METHODS: In 11 patients,
IL-6, CRP and sPLA(2) levels were assessed in blood samples drawn before (t(0)),
at the end (t(180)) and 24 h after the start of HD (t(1440)). All patients were
dialysed on Cuprammonium (CU) and Polysulphon (PS) dialysers and seven patients
underwent an additional HD session on CU plus a dialysate filter (CUf). RESULTS:
IL-6 levels were increased significantly at t(180) compared with t(0) (P<0.02)
with both CU and CUf. At t(1440), IL-6 levels had returned to baseline. In
contrast, marked fluctuations did not occur during HD with PS. At t(180), IL-6
was significantly greater with CU and CUf devices, than with PS (P<0.02).
Following HD with CU and CUf, a significant increase in CRP was observed at
t(1440), compared with postdialysis values (P=0.05). In addition, sPLA(2)
values were markedly increased at t(1440), compared with t(180), but only
significant in the case of CU (P=0.01). IL-6 levels at t(180) were significantly
correlated with CRP (r=0.50, P<0.01) and sPLA(2) (r=0.47, P=0.01) values at
t(1440). During HD with PS membranes, neither CRP nor sPLA(2) values were
markedly changed. CONCLUSIONS: In contrast to PS, both CU and CUf resulted in
elevated IL-6 plasma levels at the end of HD, compared with t(0), which
correlated with increased CRP and sPLA(2) values 24 h later. Therefore, the type
of membrane, rather than the bacterial quality of the dialysate, seems to be
responsible for the induction of the acute phase response during clinical
bicarbonate HD.
PMID- 10692525
TI - Prevalence of Japanese dialysis patients with an A-to-G mutation at nucleotide
3243 of the mitochondrial tRNA(Leu(UUR)) gene.
AB - BACKGROUND: A high prevalence of an A-to-G mutation at nucleotide 3243 of the
mitochondrial genome in patients with diabetes mellitus (DM) and/or deafness has
been reported previously. We investigated the prevalence of this mutation in
Japanese dialysis patients with associated DM and/or deafness. METHODS: We
studied 106 dialysis patients with DM, 26 with DM and deafness, and 26 with
deafness alone, using peripheral leucocytes to detect an A-to-G transition at
nucleotide 3243 of the mitochondrial gene. RESULTS: We identified this transition
in 1 of 26 patients with DM and deafness. None of the 106 DM or 26 dialysis
patients with deafness but no DM was positive for this mutation. A 42-year-old
male patient on continuous ambulatory peritoneal dialysis (CAPD) who carried this
mutation had a 20-year history of sensory hearing loss as well as hypertrophic
cardiomyopathy. CONCLUSION: We found that a mitochondrial gene mutation at
nucleotide 3243 was present in one dialysis patient with NIDDM and deafness. The
prevalence of this mutation was found to be below 1% in diabetic end-stage renal
disease patients in Japan.
PMID- 10692526
TI - Protective effects of high-density lipoprotein against oxidative stress are
impaired in haemodialysis patients.
AB - INTRODUCTION: Cardiovascular diseases represent the major cause of mortality in
haemodialysis (HD) patients. Oxidized low-density lipoprotein (Ox-LDL) is a major
cardiovascular risk factor, implicated in atherosclerotic plaque formation. It
has been suggested that high-density lipoprotein (HD) has the capacity to reduce
the oxidative modifications of LDL. The aim of this study is to analyse the
protective effects of HDL in HD patients. METHODS: In vitro copper-induced LDL
oxidation was evaluated in 12 patients with chronic renal failure (mean age
61.0+/-12.8 years) and compared to 25 healthy subjects (mean age 57.3+/-19.2
years). LDL were incubated in oxygen-saturated PBS, LDL oxidation was initiated
by Cu (II) in the presence and absence of HDL and assessed by measuring the
absorbance (abs) increase at 234 nm due to conjugated diene formation. Duration
of lag time, maximum velocity (V(max.)) of lipid peroxidation, oxidation slope
and half-time of maximum diene formation (T (1/2)) were obtained by kinetic
modelling analysis. RESULTS: HDL (1.06+/-0.31 vs 1.23+/-0.39 mmol/l) and Apo AI
(1. 17+/-0.39 vs 1.49+/-0.20 g/l) levels were decreased in HD patients. In the
absence of HDL, LDL obtained from HD patients showed an enhanced susceptibility
to oxidation in vitro as demonstrated by the significant decrease in lag time
(54.5+/-22.2 vs 79.4+/-37.8 min) and a significant increase in V(max.) (0.026+/
0.006 vs 0.017+/-0. 005 abs/min). In all cases, HDL (from 0.1 to 2 microM)
prevented LDL oxidation in vitro; however, this effect was significantly reduced
in HD patients: increase in lag time 54.2% vs 150.4% in HD vs controls; increase
in T (1/2) 52.2% vs 124.6% in HD vs controls; decrease in V(max). 13.5% vs 38.5%
in HD vs controls. CONCLUSIONS: These results suggest that qualitative
abnormalities such as an impairment of HDL-associated enzymes are associated with
a decrease of HDL levels during HD. Hence, in addition to the known impairment of
reverse cholesterol transport, the reduction of HDL protective capacity against
oxidative stress could be involved in the development of HD-induced
atherosclerosis.
PMID- 10692527
TI - The contribution of residual renal function to overall nutritional status in
chronic haemodialysis patients.
AB - BACKGROUND: The benefits of residual renal function (RRF) in peritoneal dialysis
patients have been described frequently. However, previous reports have shown
that RRF diminished faster in haemodialysis (HD) patients than in peritoneal
dialysis patients, and in most of the studies in HD patients, RRF was ignored. In
this study, the RRF in chronic HD patients was studied to assess its impact on
patients' nutritional status. METHODS: In 41 chronic HD patients with at least a
2-year history of HD treatment, RRF was determined by a urine collection for 7
consecutive days. Nutritional parameters, such as percentage body fat, fat-free
mass index, serum albumin concentration and normalized protein catabolic rate,
were also measured. RESULTS: In all 41 patients, mean weekly total Kt/V urea was
4.88 and renal Kt/V urea was 0.65. RRF was well correlated with serum albumin
concentration, but dialysis Kt/V urea was not. One year after the start of this
study, RRF and nutritional indices were re-examined and patients were classified
into two groups: with RRF, preserved residual renal diuresis over 200 ml/day
(mean, 720 ml; range, 230-1640 ml), N=23; and without RRF, persistent anuria
(mean, 51 ml; range, 0-190 ml), N=18. At the start of this study, the mean serum
albumin concentration and mean normalized protein catabolic rate in patients with
RRF were 3.84 g/dl and 1.16 g/kg/day, respectively, which were significantly
higher than those in patients without RRF (P=0.02 and P=0.0002, respectively),
despite total (renal+dialysis) Kt/V urea being equal in both groups. During the 1
year study period, there was no significant change in total Kt/V urea in either
group. Mean serum albumin concentration increased to 4.05 g/dl in patients with
RRF, but did not change significantly (from 3.66 to 3.62 g/dl) in patients
without RRF. The same trend was observed in all other parameters. CONCLUSION:
Over half of our HD patients had sufficient RRF. RRF itself may have a beneficial
effect on nutritional parameters, and it is important to determine RRF over time,
even in chronic HD patients.
PMID- 10692528
TI - The function of permanent vascular access.
AB - BACKGROUND: Complications arising from vascular access (VA) are major causes of
morbidity in patients on renal replacement therapy (RRT). They contribute to
frustration of health care providers and to high medical cost. To prevent
failures in the future it will be helpful to identify the factors that are
related to VA malfunction. METHODS: In a retrospective analysis we analysed the
types, duration and primary rate of patency of 1033 permanent vascular accesses
in 544 consecutive patients established during a 13-year period in a tertiary
care hospital. Patient characteristics, incidence, and risk factors related to VA
failure were registered. In addition, VA outcomes in patients who started
haemodialysis with a catheter and in whom initial VA failure occurred were
analysed separately. RESULTS: Forty-five per cent of patients required a central
catheter at the start of HD, but 92% of them were being dialysed with an a-v
fistula at the last observation. The total number of complications was 0.24
episodes per patient per year at risk and the rate of thrombosis 0.1. A total of
52% of patients were dialysed throughout the observation period with their
initial a-v fistula; 9.3% had more than three episodes of VA failure. The
radiocephalic a-v fistula was the VA with the best median duration, exceeding 7
years, but also the type that had the highest initial failure rate, i.e. 25% of
patients and 13% of the events. The brachiocephalic a-v fistula was the second
most frequent type of VA, with a median duration of function of 3.6 years, in
contrast to the humerobasilic a-v fistula, which exceeded 5 years. Average
patency of the different types of grafts did not exceed 1 year, with the
exception of the autologous saphenous graft with a median duration of function of
1.4 years. Patients with glomerulonephritis had the best function rates for their
VA, the median exceeding the duration of the study, whereas in half of the
diabetic patients it was less than 1 year. The duration of patency of the VA was
twice in patients below age 65 years and in elderly males compared to elderly
females. Patients who started HD with a catheter, as well as those with initial
VA failure, had a higher rate of VA failure in the subsequent course on RRT.
CONCLUSION: The radiocephalic and the humerobasilic a-v fistulae are the two
types of VA with the longest duration of function, although a high rate of
initial failure is seen with the radiocephalic a-v fistula. Age, female gender,
presence of diabetic nephropathy, start of dialysis with a catheter, and failure
to wait for initial maturation of the VA are risk factors, and account for the
majority of VA failures during RRT.
PMID- 10692529
TI - Intestinal pseudo-obstruction following renal stone extracorporeal lithotripsy in
a diabetic patient.
PMID- 10692530
TI - Steroid-responsive nephrotic syndrome with minimal-change disease and IgA
deposits in a HIV-infected patient.
PMID- 10692531
TI - Unilateral acute renal cortical necrosis (ACN) following skipping with a rope.
PMID- 10692532
TI - Healing of Fournier's gangrene of the scrotum in a haemodialysis patient after
conservative therapy alone.
PMID- 10692533
TI - Intravenous recombinant erythropoietin does not lead to an increase in
cerebrospinal fluid erythropoietin concentration.
PMID- 10692534
TI - No marked apoptosis of parathyroid cells after intraparathyroid injections of
Calcijex-observation in a patient with tertiary hyperparathyroidism after
successful renal transplantation.
PMID- 10692535
TI - The lady who had a remote history of ovarian malignancy and developed thrombotic
microangiopathy.
PMID- 10692536
TI - Ocular clues to the nature of disease causing end-stage renal failure.
PMID- 10692537
TI - A man with proteinuria, familial history of kidney disease, painful extremities
and cutaneous lesions.
PMID- 10692539
TI - Update Seminar in Nephrology and Hypertension Bratislava, Slovak Republic, 5-7
November 1998.
PMID- 10692538
TI - Implant infection in a transsexual with renal failure.
PMID- 10692540
TI - European guidelines for renal anaemia-predicting 85% compliance.
PMID- 10692541
TI - How good are nephrologists at controlling blood pressure in renal patients?
PMID- 10692542
TI - Evidence-based nephrology: the case of contrast nephropathy.
PMID- 10692543
TI - Do corticosteroids improve survival in acute renal failure due to cholesterol
atheroembolism?
PMID- 10692544
TI - The renal safety of high doses of valacyclovir for prevention of cytomegalovirus
infection after renal transplantation.
PMID- 10692545
TI - Escape probability and trapping mechanism in purple bacteria: revisited.
AB - Despite intensive research for decades, the trapping mechanism in the core
complex of purple bacteria is still under discussion. In this article, it is
attempted to derive a conceptionally simple model that is consistent with all
basic experimental observations and that allows definite conclusions on the
trapping mechanism. Some experimental data reported in the literature are
conflicting or incomplete. Therefore we repeated two already published
experiments like the time-resolved fluorescence decay in LH1-only purple bacteria
Rhodospirillum rubrum and Rhodopseudomonas viridis chromatophores with open and
closed (Q(A)(-)) reaction centers. Furthermore, we measured fluorescence
excitation spectra for both species under the two redox-conditions. These data,
all measured at room temperature, were analyzed by a target analysis based on a
three-state model (antenna, primary donor, and radical pair). All states were
allowed to react reversibly and their decay channels were taken into
consideration. This leads to seven rate constants to be determined. It turns out
that a unique set of numerical values of these rate constants can be found, when
further experimental constraints are met simultaneously, i.e. the ratio of the
fluorescence yields in the open and closed (Q(A)(-)) states F(m)/F(o)
approximately 2 and the P(+)H(-)-recombination kinetics of 3-6 ns. The model
allows to define and to quantify escape probabilities and the transfer
equilibrium. We conclude that trapping in LH1-only purple bacteria is largely
transfer-to-the-trap-limited. Furthermore, the model predicts properties of the
reaction center (RC) in its native LH1-environment. Within the framework of our
model, the predicted P(+)H(-)-recombination kinetics are nearly indistinguishable
for a hypothetically isolated RC and an antenna-RC complex, which is in contrast
to published experimental data for physically isolated RCs. Therefore RC
preparations may display modified kinetic properties.
PMID- 10692546
TI - 31P magnetic resonance spectroscopy study of phosphocreatine recovery kinetics in
skeletal muscle: the issue of intersubject variability.
AB - We have analyzed by (31)P MRS the relationship between kinetic parameters of
phosphocreatine (PCr) recovery and end-of-exercise status under conditions of
moderate and large acidosis induced by dynamic exercise. Thirteen healthy
subjects performed muscular contractions at 0.47 Hz (low frequency, moderate
exercise) and 0.85 Hz (high frequency, heavy exercise). The rate constant of PCr
resynthesis (k(PCr)) varied greatly among subjects (variation coefficients: 43
vs. 57% for LF vs. HF exercises) and protocols (k(PCr) values: 1.3+/-0.5 min(-1)
vs. 0.9+/-0.5 min(-1) for LF vs. HF exercises, P<0.03). The large intersubject
variability can be captured into a linear relationship between k(PCr), the amount
of PCr consumed ([PCr(2)]) and pH reached at the end of exercise (pH(end))
(k(PCr)=-3.3+0.7 pH(end)-0.03 [PCr(2)]; P=0.0007; r=0.61). This dual relationship
illustrates that mitochondrial activity is affected by end-of-exercise metabolic
status and allows reliable comparisons between control, diseased and trained
muscles. In contrast to k(PCr), the initial rate of PCr recovery and the maximum
oxidative capacity were always constant whatever the metabolic conditions of end
of-exercise and can then be additionally used in the identification of
dysfunctions in the oxidative metabolic pathway.
PMID- 10692547
TI - Tyr(30) of amicyanin is not critical for electron transfer to cytochrome c-551i:
implications for predicting electron transfer pathways.
AB - A Pathways analysis of the methylamine dehydrogenase-amicyanin-cytochrome c-551i
protein electron transfer (ET) complex predicts two sets of ET pathways of
comparable efficiency from the type I copper of amicyanin to the heme of
cytochrome c-551i. In one pathway, the electron exits copper via the Cys(92)
copper ligand, and in the other, it exits via the Met(98) copper ligand. If the
Pathways algorithm is modified to include contributions from the anisotropy of
metal-ligand coupling, independent of differences in copper-ligand bond length,
then the pathways via Cys(92) are predicted to be at least 100-fold more strongly
coupled than the pathways via any of the other copper ligands. All of the favored
pathways via Cys(92) include a through-space jump from Cys(92) to the side chain
of Tyr(30). To determine whether or not the pathways via Cys(92) are
preferentially used for ET, Tyr(30) was changed to other amino acid residues by
site-directed mutagenesis. Some mutant proteins were very unstable suggesting a
role for Tyr(30) in stabilizing the protein structure. Y30F and Y30I mutant
amicyanins could be isolated and analyzed. For the Y30I mutant, the modified
Pathways analysis which favors ET via Cys(92) predicts a decrease in ET rate of
at least two orders of magnitude, whereas the standard Pathways analysis predicts
no change in ET rate since ET via Met(98) is not affected. Experimentally, the ET
rates of the Y30I and Y30F mutants were indistinguishable from that of wild-type
amicyanin. Likely explanations for these observations are discussed as are their
implications for predicting pathways for ET reactions of metalloproteins.
PMID- 10692548
TI - Mutations in the tether region of the iron-sulfur protein affect the activity and
assembly of the cytochrome bc(1) complex of yeast mitochondria.
AB - Resolution of the crystal structure of the mitochondrial cytochrome bc(1) complex
has indicated that the extra-membranous extrinsic domain of the iron-sulfur
protein containing the 2Fe2S cluster is connected by a tether to the
transmembrane helix that anchors the iron-sulfur protein to the complex. To
investigate the role of this tether in the cytochrome bc(1) complex, we have
mutated the conserved amino acid residues Ala-86, Ala-90, Ala-92, Lys-93 and Glu
95 and constructed deletion mutants DeltaVLA(88-90) and DeltaAMA(90-92) and an
insertion mutant I87AAA88 in the iron-sulfur protein of the yeast, Saccharomyces
cerevisiae. In cells grown at 30 degrees C, enzymatic activities of the bc(1)
complex were reduced 22-56% in mutants A86L, A90I, A92C, A92R and E95R, and the
deletion mutants, DeltaVLA(88-90) and DeltaAMA(90-92), while activity of the
insertion mutant was reduced 90%. No loss of cytochromes b or c-c(1), detected
spectrally, or the iron-sulfur protein, determined by quantitative
immunoblotting, was observed in these mutants with the exception of the mutants
of Ala-92 in which the loss of activity paralleled a loss in the amount of the
iron-sulfur protein. EPR spectroscopy revealed no changes in the iron-sulfur
cluster of mutants A86L, A90I, A92R or the deletion mutant DeltaVLA(88-90).
Greater losses of both protein and activity were observed in all of the mutants
of Ala-92 as well as in A90F grown at 37 degrees C. suggesting that these
conserved alanine residues may be involved in maintaining the stability of the
iron-sulfur protein and its assembly into the bc(1) complex. By contrast, no
significant loss of iron-sulfur protein was observed in the mutants of Ala-86 in
cells grown at either 30 degrees C or 37 degrees C despite the 50-70% loss of
enzymatic activity suggesting that Ala-86 may play a critical role in catalysis
in the bc(1) complex.
PMID- 10692549
TI - Growth of the yeast Saccharomyces cerevisiae on a non-fermentable substrate:
control of energetic yield by the amount of mitochondria.
AB - The purpose of this study was to investigate the long-term control of ATP
synthesis during the course of Saccharomyces cerevisiae batch grown on lactate, a
purely respiratory substrate. For this, we used a respirometric and on-line
calorimetric approach to analyse the energetic balances and the control of
energetic metabolism during growth. Enthalpic growth yields assessed by enthalpy
balance (taking account of substrate consumption, by-product accumulation,
biomass formation and heat dissipation) remained constant during the entire
exponential growth. Moreover, at the same time, a parallel decrease in basal
respiratory rate and enthalpy flux occurred. It is shown that the decrease in
respiration corresponds to a decrease in the amount of mitochondria per cell but
not to a change of steady state of oxidative phosphorylation. Taking into account
the part of energy used for maintenance, it can be concluded that mitochondria by
themselves are the major heat dissipative system in a fully aerobic metabolism,
and that the decrease in the amount of mitochondria when growth rate decreases
leads to an enthalpic growth yield constant.
PMID- 10692550
TI - Calcium regulation of oxidative phosphorylation in rat skeletal muscle
mitochondria.
AB - Activation of oxidative phosphorylation by physiological levels of calcium in
mitochondria from rat skeletal muscle was analysed using top-down elasticity and
regulation analysis. Oxidative phosphorylation was conceptually divided into
three subsystems (substrate oxidation, proton leak and phosphorylation) connected
by the membrane potential or the protonmotive force. Calcium directly activated
the phosphorylation subsystem and (with sub-saturating 2-oxoglutarate) the
substrate oxidation subsystem but had no effect on the proton leak kinetics. The
response of mitochondria respiring on 2-oxoglutarate at two physiological
concentrations of free calcium was quantified using control and regulation
analysis. The partial integrated response coefficients showed that direct
stimulation of substrate oxidation contributed 86% of the effect of calcium on
state 3 oxygen consumption, and direct activation of the phosphorylation
reactions caused 37% of the increase in phosphorylation flux. Calcium directly
activated phosphorylation more strongly than substrate oxidation (78% compared to
45%) to achieve homeostasis of mitochondrial membrane potential during large
increases in flux.
PMID- 10692551
TI - Fast energy transfer between BChl d and BChl c in chlorosomes of the green sulfur
bacterium Chlorobium limicola.
AB - We have studied energy transfer in chlorosomes of Chlorobium limicola UdG6040
containing a mixture of about 50% bacteriochlorophyll (BChl) c and BChl d each.
BChl d-depleted chlorosomes were obtained by acid treatment. The energy transfer
between the different pigment pools was studied using both steady-state and time
resolved fluorescence spectroscopy at room temperature and low temperature. The
steady-state emission of the intact chlorosome originated mainly from BChl c, as
judged by comparison of fluorescence emission spectra of intact and BChl d
depleted chlorosomes. This indicated that efficient energy transfer from BChl d
to BChl c takes place. At room temperature BChl c/d to BChl a excitation energy
transfer (EET) was characterized by two components of 27 and 74 ps. At low
temperature we could also observe EET from BChl d to BChl c with a time constant
of approximately 4 ps. Kinetic modeling of the low temperature data indicated
heterogeneous fluorescence kinetics and suggested the presence of an additional
BChl c pool, E790, which is more or less decoupled from the baseplate BChl a.
This E790 pool is either a low-lying exciton state of BChl c which acts as a trap
at low temperature or alternatively represents the red edge of a broad
inhomogeneous absorption band of BChl c. We present a refined model for the
organization of the spatially separated pigment pools in chlorosomes of Cb.
limicola UdG6040 in which BChl d is situated distal and BChl c proximal with
respect to the baseplate.
PMID- 10692552
TI - A covalent tandem dimer of the mitochondrial ADP/ATP carrier is functional in
vivo.
AB - The adenine nucleotide carrier, or Ancp, is an integral protein of the inner
mitochondrial membrane. It is established that the inactive Ancp bound to one of
its inhibitors (CATR or BA) is a dimer, but different contradictory models were
proposed over the past years to describe the organization of the active Ancp. In
order to decide in favor of a single model, it is necessary to establish the
orientations of the N- and C-termini and thus the parity of the Ancp
transmembrane segments (TMS). According to this, we have constructed a gene
encoding a covalent tandem dimer of the Saccharomyces cerevisiae Anc2p and we
demonstrate that it is stable and active in vivo as well as in vitro. The
properties of the isolated dimer are strongly similar to those of the native
Anc2p, as seen from nucleotide exchange and inhibitor binding experiments. We can
therefore conclude that the native Anc2p has an even number of TMS and that the N
and C-terminal regions are exposed to the same cellular compartment.
Furthermore, our results support the idea of a minimal dimeric functional
organization of the Ancp in the mitochondrial membrane and we can suggest that
TMS 1 of one monomer and TMS 6 of the other monomer in the native dimer are very
close to each other.
PMID- 10692553
TI - Effects of fluorescent pseudo-ATP and ATP-metal analogs on secondary structure of
Na(+)/K(+)-ATPase.
AB - The secondary structure of Na(+)/K(+)-ATPase after modification of the ATP
binding sites was analyzed. Consistently with recent reports, we found in trypsin
treated Na(+)/K(+)-ATPase additionally to alpha-helix also beta-sheet structures
in the transmembrane segments. However, binding of fluorescein 5'-isothiocyanate
(FITC), the pseudo-ATP analog, to the ATP-binding site did not affect the
secondary structure of undigested Na(+)/K(+)-ATPase. Consequently, fluorescence
intensity changes of FITC-labeled Na(+)/K(+)-ATPase commonly used to observe
conformational transitions of the enzyme reflect physiological changes of the
native structure. The metal complex analogues of ATP, Cr(H(2)O)(4)ATP and
Co(NH(3))(4)ATP, on the other hand, affected the secondary structure of
Na(+)/K(+)-ATPase. We propose that these changes in the secondary structure are
responsible for inhibition of backdoor phosphorylation.
PMID- 10692554
TI - Electrospray ionization and matrix-assisted laser desorption ionization mass
spectrometry. Emerging technologies in biomedical sciences.
AB - Tremendous progress in biomedical sciences has been made possible in part by
recent advances in bioanalytical methods, in particular biological mass
spectrometry. Since the introduction of electrospray ionization mass spectrometry
(ESI-MS) in 1984 and matrix-assisted laser desorption ionization mass
spectrometry (MALDI-MS) in 1988, the field of bioanalytical mass spectrometry has
seen rapid growth. In concert with separation techniques such as capillary
electrophoresis and high performance liquid chromatography, mass spectrometry
allows characterization of a large array of small organic molecules, peptides,
proteins, oligonucleotides, and RNA fragments. Thus, substantially more expedient
and definitive determination of molecular weight is now possible by mass
spectrometric analysis. In this commentary, general descriptions of ESI- and
MALDI-MS are presented. Furthermore, several recent developments and applications
in addressing difficult biological problems are discussed.
PMID- 10692555
TI - Active transport inhibition in rat small intestine by amphiphilic amines: an in
vitro study with various local anaesthetics.
AB - In the present investigation with rings of everted rat small intestine,
amphiphilic amines such as local anaesthetics (e.g. lidocaine, procaine,
tolycaine) were employed to study their effects on intestinal absorption of
methyl alpha-D-glucoside, L-leucine, D-fructose, and 2-deoxy-D-glucose. All the
amphiphilic amines tested, except for benzocaine, significantly inhibited Na(+)
dependent active uptake of methyl alpha-D-glucoside and L-leucine while leaving
uptake of D-fructose (facilitated diffusion) and 2-deoxy-D-glucose (passive
diffusion) unaffected. Increasing concentrations of lidocaine in the incubation
medium inhibited the uptake of methyl alpha-D-glucoside (IC(50) approximately 3.5
mmol/L) and L-leucine (IC(50) approximately 6 mmol/L) in a dose-dependent manner.
Complete reversibility of the inhibitory effect could only be achieved at short
term incubations (=2 min) and low lidocaine concentrations (=3 mmol/L),
otherwise inhibition became partially irreversible. Uptake kinetics of methyl
alpha-D-glucoside and L-leucine in the presence of lidocaine revealed a
significant increase in the apparent Michaelis constant, leaving the maximal
transport capacity essentially unaltered. Reducing the Na(+) concentration in the
incubation medium aggravated inhibition by lidocaine of the uptake of methyl
alpha-D-glucoside. Analysis of the inhibition kinetics by Dixon plots revealed a
competitive interaction between Na(+) and the amphiphiles. However, phlorizin
binding was not affected by lidocaine. Changing the pH of the incubation medium
from 5.6 to 8.0 increased the inhibitory effect of the amphiphiles, which
indicated that the non-ionised and, thus, more lipophilic form participates in
the mechanism of inhibition. However, benzocaine, a rather lipophilic local
anaesthetic with no aliphatic amino group, did not impair active uptake of methyl
alpha-D-glucoside. Whether the amphiphilic amines act by their partition into the
membrane matrix or directly interact with sodium binding sites remains to be
elucidated, however.
PMID- 10692556
TI - Pharmacological delta1- and delta2-opioid receptor subtypes in the human
neuroblastoma cell line SK-N-BE: no evidence for distinct molecular entities.
AB - The two pharmacological delta-opioid receptor subtypes, delta1 and delta2, have
been defined on the basis of pharmacological tools but remain to be characterized
at the molecular level, since only a single cDNA has been cloned. The present
study aimed to investigate the pharmacological properties of delta1- and delta2
opioid subtypes expressed in the human neuroblastoma cell line SK-N-BE and to
characterize their putative corresponding mRNAs. Binding experiments using
"selective" delta1- and delta2-opioid agonists and antagonists revealed the
presence of two binding sites, demonstrating the presence of these delta1-opioid
subtypes as they were previously described. The activation of these
pharmacological subtypes by the selective agonists induced the incorporation of
[alpha-(32)P]azidoanilide-GTP into Galpha(i2)/Galpha(0) subunits with the same
efficiency and potency and inhibited adenosine 3', 5'-cyclic monophosphate (cAMP)
accumulation with similar efficiency, while their sustained activation for 15 min
induced a cross-desensitization. The "selective" delta1 and delta2 antagonists, 7
benzylidenenaltrexone and naltrindole benzofuran, respectively, were found to be
as potent in blocking the inhibition of cAMP accumulation induced by both [D
Pen(2,5)]enkephalin and Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH(2). The possibility that
delta-opioid subtypes could arise from alternative splicing was ruled out by
reverse transcription-polymerase chain reaction (RT-PCR) experiments and the
sequencing of PCR products, which revealed the presence of a single transcript
encoding for the delta-opioid receptor. Different possibilities which could
account for the delta-opioid receptor heterogeneity observed in the SN-N-BE cell
line are discussed.
PMID- 10692557
TI - Reversible and syntopic interaction between angiotensin receptor antagonists on
Chinese hamster ovary cells expressing human angiotensin II type 1 receptors.
AB - Evidence for a competitive type of interaction between angiotensin II type 1
(AT(1)) antagonists on Chinese hamster ovary cells expressing the human AT(1)
receptor (CHO-AT(1)) was obtained by analyzing the binding of [(3)H]-2-ethoxy-1
[(2'-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl]-1H- ben zimidazoline-7-carboxylic
acid ([(3)H]candesartan) and by measuring the AT-induced production of inositol
phosphates. The AT(1) antagonists candesartan, 2-n-butyl-4-chloro-1-[(2'-(1H
tetrazol-5-yl)biphenyl-4-yl)methyl]+ ++imid azole-5-carboxylic acid (EXP3174), or
2-n-butyl-4-chloro-5-hydroxymethyl-1-[(2'-(1H-tetrazol-5-yl)bip hen yl- 4
yl)methyl]imidazole (losartan) produced a concentration-dependent increase in the
apparent K(d) values of [(3)H]candesartan in saturation binding experiments,
while the B(max) values were unchanged. Furthermore, the dissociation rate of the
radioligand initiated by 1 microM unlabelled candesartan was not changed in the
presence of 10 microM losartan, 10 microM EXP3174, or 10 microM irbesartan (2-n
butyl-4-spirocyclopentane-1-[(2'-(1H-tetrazol-5-yl)b iph enyl-4-yl) methyl]2
imidazolin-5-one)). Preincubation of the CHO-AT(1) cells with candesartan,
EXP3174, and irbesartan caused a reduction in the maximal AT-induced inositol
mono-, bis-, and trisphosphate production. This insurmountable effect was
reversed in the presence of 1 microM losartan. In line with this finding, the
insurmountable antagonist concentration-inhibition curves at 10 microM AT were
shifted to the right in the presence of losartan. For candesartan this effect was
concentration-dependent, yielding a pK(B) value for losartan of 7.7, which is
similar to the pK(B) from previously obtained AT concentration-response curves.
Finally, the dissociation rate of candesartan, EXP3174, irbesartan, and losartan
was determined by measuring the recovery of AT responses after antagonist
pretreatment and washing of the cells with medium containing 1 microM losartan to
prevent re-association of the insurmountable antagonists. In addition, similar
kinetic data were obtained from the slowing of the [(3)H]candesartan association
rate to antagonist preincubated cells.
PMID- 10692558
TI - BGP-15, a nicotinic amidoxime derivate protecting heart from ischemia reperfusion
injury through modulation of poly(ADP-ribose) polymerase.
AB - The protective effect of O-(3-piperidino-2-hydroxy-1-propyl)nicotinic amidoxime
(BGP-15) against ischemia-reperfusion-induced injury was studied in the
Langendorff heart perfusion system. To understand the molecular mechanism of the
cardioprotection, the effect of BGP-15 on ischemic-reperfusion-induced reactive
oxygen species (ROS) formation, lipid peroxidation single-strand DNA break
formation, NAD(+) catabolism, and endogenous ADP-ribosylation reactions were
investigated. These studies showed that BGP-15 significantly decreased leakage of
lactate dehydrogenase, creatine kinase, and aspartate aminotransferase in
reperfused hearts, and reduced the rate of NAD(+) catabolism. In addition, BGP-15
dramatically decreased the ischemia-reperfusion-induced self-ADP-ribosylation of
nuclear poly(ADP-ribose) polymerase(PARP) and the mono-ADP-ribosylation of an
endoplasmic reticulum chaperone GRP78. These data raise the possibility that BGP
15 may have a direct inhibitory effect on PARP. This hypothesis was tested on
isolated enzyme, and kinetic analysis showed a mixed-type (noncompetitive)
inhibition with a K(i) = 57 +/- 6 microM. Furthermore, BGP-15 decreased levels of
ROS, lipid peroxidation, and single-strand DNA breaks in reperfused hearts. These
data suggest that PARP may be an important molecular target of BGP-15 and that
BGP-15 decreases ROS levels and cell injury during ischemia-reperfusion in the
heart by inhibiting PARP activity.
PMID- 10692559
TI - Mechanisms underlying ketoconazole-induced Ca(2+) mobilization in Madin-Darby
canine kidney cells.
AB - The effect of ketoconazole on Ca(2+) signaling in Madin-Darby canine kidney
(MDCK) cells was investigated by using fura-2 as a Ca(2+) probe. Ketoconazole
evoked increases in cytosolic free Ca(2+) concentration ([Ca(2+)](i))
concentration dependently. The response was decreased by external Ca(2+) removal.
In Ca(2+)-free medium, pretreatment with ketoconazole abolished the [Ca(2+)](i)
rise induced by thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2+)
pump. Addition of 3 mM Ca(2+) induced a significant [Ca(2+)](i) rise after
preincubation with 150 microM ketoconazole in Ca(2+)-free medium. Pretreatment
with aristolochic acid (40 microM) to inhibit phospholipase A(2) inhibited the
150-microM-ketoconazole-induced internal Ca(2+) release by 37%, but inhibition of
phospholipase C with 1-(6-((17beta-3-methoxyestra-1,3, 5(10)-trien-17
yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122) (2 microM) had no effect.
Collectively, we found that ketoconazole increases [Ca(2+)](i) in MDCK cells by
releasing Ca(2+) from thapsigargin-sensitive pools in a manner independent of the
production of inositol-1,4,5-trisphosphate, followed by Ca(2+) influx from the
external space.
PMID- 10692560
TI - alpha-fluoro-beta-alanine: effects on the antitumor activity and toxicity of 5
fluorouracil.
AB - We have shown previously that (R)-5-fluoro-5,6-dihydrouracil (FUraH(2))
attenuates the antitumor activity of 5-fluorouracil (FUra) in rats bearing
advanced colorectal carcinoma. Presently, we found that alpha-fluoro-beta-alanine
(FBAL), the predominant catabolite of FUra that is formed rapidly via FUraH(2),
also decreased the antitumor activity and potentiated the toxicity of FUra. In
rats treated with Eniluracil (5-ethynyluracil, GW776), excess FBAL, in a 9:1
ratio to FUra, produced similar effects when administered 1 hr before,
simultaneously with, or 2 hr after FUra. FBAL also decreased the antitumor
activity of FUra in Eniluracil-treated mice bearing MOPC-315 myeloma at a 9:1
ratio with FUra, but not at a 2:1 ratio. FBAL did not affect the antitumor
activity of FUra in mice bearing Colon 38 tumors. We also evaluated the effect of
thymidylate synthase (TS) and thymidine kinase (TK) from tumor extracts after
FUra +/- Eniluracil +/- FBAL treatment. The activity of TK was similar among the
three groups at both 18 and 120 hr. There was also no difference in TS inhibition
( approximately 35%) at 18 hr. However, significantly more TS inhibition was
observed in the Eniluracil/FUra group than in the FUra-alone group at 120 hr.
FBAL did not alter the effect of Eniluracil/FUra in TS inhibition. Neither
FUraH(2) nor FBAL affected the IC(50) of FUra in culture. Thus, the effect of
FBAL did not result from direct competition with FUra uptake or immediate
anabolism. Either another downstream catabolite that is not formed in cell
culture is the active agent, or the effect requires the complexity of a living
organism or an established tumor.
PMID- 10692561
TI - Role of human liver microsomal CYP3A4 and CYP2B6 in catalyzing N
dechloroethylation of cyclophosphamide and ifosfamide.
AB - The anticancer alkylating agents cyclophosphamide (CPA) and ifosfamide (IFA) are
prodrugs that undergo extensive P450-catalyzed metabolism to yield both active (4
hydroxylated) and therapeutically inactive but neurotoxic (N-dechloroethylated)
metabolites. Whereas the human liver microsomal P450 catalysts of CPA and IFA 4
hydroxylation are well characterized, the P450 enzyme catalysts of the
alternative N-dechloroethylation pathway are poorly defined. Analysis of a panel
of fifteen human P450 cDNAs in the baculovirus expression system ('Supersomes')
demonstrated that CYP3A4 exhibited the highest N-dechloroethylation activity
toward both CPA and IFA, whereas CYP2B6 displayed high N-dechloroethylation
activity toward IFA, but not CPA. The contributions of each human P450 to overall
liver microsomal N-dechloroethylation were calculated using a recently described
relative substrate-activity factor method, and were found to be in excellent
agreement with the results of inhibition studies using the CYP3A inhibitor
troleandomycin and an inhibitory monoclonal antibody to CYP2B6. With CPA as
substrate, CYP3A4 was shown to catalyze >/=95% of liver microsomal N
dechloroethylation, whereas with IFA as substrate, CYP3A4 catalyzed an average of
approximately 70% of liver microsomal N-dechloroethylation (range = 40-90%), with
the balance of this activity catalyzed by CYP2B6 (range = 10-70%, dependent on
the CYP2B6 content of the liver). Because CYP2B6 can make a significant
contribution to human liver microsomal IFA N-dechloroethylation, but only a minor
contribution to IFA 4-hydroxylation, the selective inhibition of hepatic CYP2B6
activity in individuals with a high hepatic CYP2B6 content may provide a useful
approach to minimize the formation of therapeutically inactive but toxic N
dechloroethylated IFA metabolites.
PMID- 10692562
TI - Phosphono analogs of glutathione: inhibition of glutathione transferases,
metabolic stability, and uptake by cancer cells.
AB - Glutathione transferases (GSTs) have been shown to play an important role in
multiple drug resistance in cancer chemotherapy. The inactivation of GST isoforms
could lead to an enhanced activity of cytotoxic drugs. Thus, we have developed
glutathione phosphono analogs [(S)-gamma-glutamyl-(2RS)-(+/-)-2-amino
(dialkoxyphosphinyl)-ac etylgl ycines], which were previously shown to be
inhibitors of GSTP1-1. In the present study, the inhibition characteristics of
these analogs, including isoenzyme specificities, type of inhibition, and
determination of K(i) values, were determined. The inhibition of class alpha GSTs
was competitive towards GSH. A mixed-type, non-competitive inhibition of class mu
and pi GSTs was observed. The K(i) values varied between 880 +/- 210 and 0.45 +/-
0.1 microM. The inhibitors were most effective towards class mu GSTs. In order to
investigate the potential use of these GST inhibitors in intact cellular systems,
two additional approaches were examined. Firstly, the metabolic stability was
tested with purified gamma-glutamyl transpeptidase and cell homogenates as well
as during incubation of cell lines. No appreciable degradation was observed in
any of the tested systems. Secondly, to facilitate cellular uptake, three
derivatives were synthesized in which the glycine carboxylic group was
esterified. Uptake and a possible intracellular cleavage to the corresponding
free acids were monitored by HPLC analysis. The esters were effectively
transported into HT29 (colon cancer) and EPG85-257P (gastric cancer) cells,
respectively, and readily converted into the more active free acids. In
conclusion, the tested inhibitors may be regarded as model compounds for the
development of modulating agents in cancer chemotherapy.
PMID- 10692563
TI - Triapine (3-aminopyridine-2-carboxaldehyde- thiosemicarbazone): A potent
inhibitor of ribonucleotide reductase activity with broad spectrum antitumor
activity.
AB - Previous studies from our laboratories have shown that (a) Triapine() is a potent
inhibitor of ribonucleotide reductase activity and (b) hydroxyurea-resistant
L1210 leukemia cells are fully sensitive to Triapine. In an analogous manner,
Triapine was similarly active against the wild-type and a hydroxyurea-resistant
subline of the human KB nasopharyngeal carcinoma. Triapine was active in vivo
against the L1210 leukemia over a broad range of dosages and was curative for
some mice. This agent also caused pronounced inhibition of the growth of the
murine M109 lung carcinoma and human A2780 ovarian carcinoma xenografts in mice.
Optimum anticancer activity required twice daily dosing due to the duration of
inhibition of DNA synthesis which lasted about 10 hr in L1210 cells treated with
Triapine in vivo. DNA synthesis in normal mouse tissues (i.e. duodenum and bone
marrow) uniformly recovered faster than that in L1210 leukemia cells,
demonstrating a pharmacological basis for the therapeutic index of this agent.
Triapine was more potent than hydroxyurea in inhibiting DNA synthesis in L1210
cells in vivo, and the effects of Triapine were more pronounced. In addition, the
duration of the inhibition of DNA synthesis in leukemia cells from mice treated
with Triapine was considerably longer than in those from animals treated with
hydroxyurea. Combination of Triapine with various classes of agents that damage
DNA (e.g. etoposide, cisplatin, doxorubicin, and 1-acetyl-1,2-bis(methylsulfonyl)
2-(2-chloroethyl)hydrazine) resulted in synergistic inhibition of the L1210
leukemia, producing long-term survivors of tumor-bearing mice treated with
several dosage levels of the combinations, whereas no enhancement of survival was
found when Triapine was combined with gemcitabine or cytosine arabinoside. The
findings demonstrate the superiority of Triapine over hydroxyurea as an
anticancer agent and further suggest that prevention by Triapine of repair of DNA
lesions created by agents that damage DNA may result in efficacious drug
combinations for the treatment of cancer.
PMID- 10692564
TI - The relative importance of NADPH: cytochrome c (P450) reductase for determining
the sensitivity of human tumour cells to the indolequinone EO9 and related
analogues lacking functionality at the C-2 and C-3 positions.
AB - Analogues of EO9 (3-hydroxymethyl-5-aziridinyl-1-methyl-2[1H-indole-4-7
dione]prop-2-e n-1-ol) which lack functionality at either the C-2 or C-3 position
were synthesised. The aim was to establish the importance of each group towards
toxicity and to give an indication as to whether substitution at either position
altered activation and toxicity after metabolism by cellular NADPH: cytochrome c
(P450) reductase (P450R). MDA231 breast cancer cells were transfected with the
cDNA for human P450R and stable clones were isolated. These high P450R-expressing
clones were used to determine the aerobic and hypoxic toxicity of EO9 and the two
analogues that lacked functionality at either C-2 or C-3. The results showed that
P450R was strongly implicated in the bioactivation of EO9 and its analogues under
both of these conditions. This data also showed that the C-3 functionality was
primarily implicated in hypoxic toxicity.
PMID- 10692565
TI - Activation of transcription factors activator protein-1 and nuclear factor-kappaB
by 2,3,7,8-tetrachlorodibenzo-p-dioxin.
AB - 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD; dioxin), the prototype agonist of the
aromatic hydrocarbon (Ah) receptor, is a potent tumor promoter as well as a
complete liver carcinogen that produces an oxidative stress response in rodents
and in cultured cell lines. It has been proposed that TCDD promotes neoplastic
transformation through oxidative signal transduction pathways, which results in
activation of immediate-early response transcription factors. To set the stage
for a test of this hypothesis, we evaluated the effect of TCDD treatment on the
activation of several transcription factors, including those in the nuclear
factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) families, which are
activated by changes in the redox state of cells. In an extension of prior
results, we found that TCDD treatment produced a sustained overexpression of AP-1
for at least 72 hr in wild-type mouse hepatoma Hepa-1 cells, but not in the Ah
receptor-deficient derivative c35 or in cytochrome P450-1A1 (CYP1A1)-negative c37
cells. In addition, TCDD treatment caused a significant increase in the DNA
binding activity of NF-kappaB, but not in the activities of the other
transcription factors tested. AP-1 and NF-kappaB activation were blocked by the
thiol antioxidant N-acetylcysteine and by nordihydroguaiaretic acid, an
antioxidant and lipooxygenase inhibitor and an inhibitor of the epoxygenase
activity of CYP1A1, and did not take place in c35, c37, or in Ah nuclear
translator-deficient c4 cells. Hence, sustained activation of these two
transcription factors by TCDD is likely to result from a CYP1A1-dependent and Ah
receptor complex-dependent oxidative signal. Electrophoretic mobility supershift
analyses with specific antibodies showed that most of the increase in NF-kappaB
binding activity could be accounted for by increases in p50/p50 complexes. Since
these complexes are known to repress NF-kappaB-dependent gene transcription, our
results delineate a second molecular mechanism, in addition to the recently found
block of tumor necrosis factor-alpha-mediated p50/p65 activation, that may be
responsible for the immunosuppresive effects of TCDD.
PMID- 10692566
TI - No effect of carvedilol on nitric oxide generation in phagocytes but modulation
of production of superoxide ions.
AB - Since carvedilol has been claimed to possess antioxidative effects, this drug
might affect functional responses, including nitric oxide (NO) generation, of
polymorphonuclear neutrophils (PMN) and macrophages. When we assessed the effects
of carvedilol on PMN responses in vitro, we observed that carvedilol dose
dependently modulated generation of superoxide ions by NADPH oxidase when induced
by the formylpeptide formyl-methionyl-leucyl-phenylalanine (fMLP) or the phorbol
ester phorbol myristate acetate. This effect was not coupled to diminished
phospholipase C activity. In contrast to the effect on NADPH oxidase, neither the
fMLP-elicited NO generation by PMN nor the response of the murine macrophage cell
line J774 to lipopolysaccharide was affected. There was no evidence from cell
free assay systems that carvedilol is a scavenger for superoxide ions or NO.
Moreover, carvedilol did not affect other reactions dependent on NO, e.g.
spontaneous or fMLP-stimulated PMN migration or lipoxin A(4)-, fMLP-, or A23187
induced neutrophil cytotoxicity for human umbilical vein endothelial cells. Thus,
these effects point to the possibility that carvedilol modulates the NADPH
oxidase of PMN but leaves the nitric oxide synthase of phagocytes intact.
PMID- 10692567
TI - Effect of silymarin on biliary bile salt secretion in the rat.
AB - The effect of the hepatoprotector silymarin on bile secretion, with particular
regard to bile salt secretion, was studied in Wistar rats. Silymarin (25, 50,
100, and 150 mg/kg/day, i.p., for 5 days) induced a dose-dependent increase in
bile flow and bile salt secretion, the maximal effect being reached at a dose of
100 mg/kg/day (+17 and +49%, for bile flow and bile salt output, respectively; P
< 0.05). Assessment of bile salt composition in bile revealed that stimulation of
the bile salt secretion was accounted for mainly by an increase in the biliary
secretion of beta-muricholate and, to a lesser extent, of alpha-muricholate,
chenodeoxycholate, ursodeoxycholate, and deoxycholate. The maximum secretory rate
(T(m)) of bile salts, as assessed by infusing the non-hepatotoxic bile salt
tauroursodeoxycholate i.v. at stepwise-increasing rates, was not influenced by
silymarin. The flavonolignan also increased the endogenous bile salt pool size
(+53%, P < 0.05) and biliary bile acid excretion after bile acid pool depletion
(+54%, P < 0.05), a measure of de novo bile salt synthesis. These results suggest
that silymarin increases the biliary excretion and the endogenous pool of bile
salts by stimulating the synthesis, among others, of hepatoprotective bile salts,
such as beta-muricholate and ursodeoxycholate.
PMID- 10692568
TI - Vertebrate pseudogenes.
AB - Pseudogenes are commonly encountered during investigation of the genomes of a
wide range of life forms. This review concentrates on vertebrate, and in
particular mammalian, pseudogenes and describes their origin and subsequent
evolution. Consideration is also given to pseudogenes that are transcribed and to
the unusual group of genes that exist at the interface between functional genes
and non-functional pseudogenes. As the sequences of different genomes are
characterised, the recognition and interpretation of pseudogene sequences will
become more important and have a greater impact in the field of molecular
genetics.
PMID- 10692569
TI - Preparation and characterization of 'heparinocytes': erythrocytes with covalently
bound low molecular weight heparin.
AB - In an attempt to create the possibility of stable, long acting, intravascular
anticoagulation, low molecular weight heparin was modified by introducing a
sulfhydryl group into the molecule (LMWH-SH). Human erythrocytes were covalently
grafted with LMWH-SH by the use of a heterobifunctional coupling reagent which
reacts with the SH group of LMWH-SH and surface exposed amino groups of
erythrocytes now called 'heparinocytes' (HC). HC were morphologically
indistinguishable from untreated erythrocytes and displayed identical osmotic
resistance. The functionality of HC was analyzed by classical coagulation tests
in which they dose dependently inhibited clot formation. HC were also functional
in recalcified whole blood inhibiting thrombin formation as assessed by the
cleavage of the chromogenic substrate S-2238. The system appears applicable as a
potential autologous, long-term anticoagulant treatment or prophylaxis.
PMID- 10692570
TI - Different epitopes are required for gp130 activation by interleukin-6, oncostatin
M and leukemia inhibitory factor.
AB - Gp130 is the common signal transducing receptor subunit of interleukin (IL)-6, IL
11, leukemia inhibitory factor (LIF), oncostatin M (OSM), ciliary neurotrophic
factor and cardiotrophin-1. IL-6 and IL-11 induce gp130 homodimerization whereas
the others lead to the formation of heterodimers with LIFR or OSMR. Binding
epitopes for IL-6 and IL-11 are located in the immunoglobulin-like domain and the
cytokine binding module (CBM). Here we show that a gp130 mutant lacking domain 1,
although unresponsive to IL-6 and IL-11, can still activate signal transducer and
activator of transcription (STAT) transcription factors in response to LIF or
OSM. Moreover, point mutations in the CBM of gp130 (F191E and V252D) that
severely impair signal transduction in response to IL-6 and IL-11 differentially
interfere with gp130 activation in response to LIF and OSM. Thus, epitopes
involved in gp130 homodimerization are distinct from those leading to the
formation of gp130/LIFR or gp130/OSMR heterodimers. These findings may serve as
the base for rational design of gp130 antagonists that specifically interfere
with bioactivity of distinct IL-6-type cytokines.
PMID- 10692571
TI - Cytoskeleton alterations of erythrocytes from patients with Fanconi's anemia.
AB - Fanconi's anemia (FA) is a very rare genetically heterogeneous disease which has
been hypothesized to be defective in the detoxification of reactive oxygen
species. In this work we report the results obtained by morphometric and
biochemical analyses on the red blood cells (RBCs) from FA patients. With respect
to RBCs from healthy donors the following changes have been detected: (i) a
variety of ultrastructural alterations, mainly surface blebbing typical of
acanthocytes and stomatocytes; (ii) a significant quantitative increase of these
altered forms; (iii) modifications of spectrin cytoskeleton network; (iv) an
altered redox balance, e.g. a decreased catalase activity and significant
variations in the GSSG/GSH ratio. We hypothesize that remodeling of the redox
state occurring in FA patients results in cytoskeleton-associated alterations of
red blood cell integrity and function.
PMID- 10692572
TI - Caspase-induced inactivation of the anti-apoptotic TRAF1 during Fas ligand
mediated apoptosis.
AB - The activation of the transcription factor NF-kappaB often results in protection
against apoptosis. In particular, pro-apoptotic tumor necrosis factor (TNF)
signals are blocked by proteins that are induced by NF-kappaB such as TNFR
associated factor 1 (TRAF1). Here we show that TRAF1 is cleaved after Asp-163
when cells are induced to undergo apoptosis by Fas ligand (FasL). The C-terminal
cleavage product blocks the induction of NF-kappaB by TNF and therefore functions
as a dominant negative (DN) form of TRAF1. Our results suggest that the
generation of DN-TRAF1 is part of a pro-apoptotic amplification system to assure
rapid cell death.
PMID- 10692573
TI - Activation of a pro-apoptotic amplification loop through inhibition of NF-kappaB
dependent survival signals by caspase-mediated inactivation of RIP.
AB - Death domain containing members of the tumor necrosis factor receptor (TNFR)
superfamily can induce apoptosis or cell activation. However, the mechanisms by
which these opposing programs are selected remain unclear. Frequently, NF-kappaB
activation conveys protection against cell death. We show that the
serine/threonine kinase RIP that is required for TNF-induced NF-kappaB activation
is processed by caspase-8 into a dominant-negative (DN) fragment during death
receptor-induced apoptosis, thereby leading to a blockade of NF-kappaB-mediated
anti-apoptotic signals. Our results suggest that cleavage of RIP is part of an
amplification loop which is triggered by Fas and most likely by other death
receptors.
PMID- 10692574
TI - Characterization of recombinant mustard trypsin inhibitor 2 (MTI2) expressed in
Pichia pastoris.
AB - The mustard trypsin inhibitor MTI2 was expressed as secretory protein in the
yeast Pichia pastoris. In order to evaluate the influence of the C-terminal amino
acids of the precursor form on the inhibitor activity, the C-terminal precursor
and the mature protein were both expressed. A third His-tagged construct was also
designed to compare alternative purification procedures. Proteins were
efficiently expressed at levels of 40-160 mg/l in shake flasks. Equilibrium
dissociation constants demonstrated that the mature protein was a stronger
inhibitor of bovine beta-trypsin compared to the precursor and His-tagged forms
(0.01 nM vs. 0.58 nM and 0.71 nM, respectively). The recombinant proteins were
active inhibitors of Spodoptera exigua gut proteases.
PMID- 10692575
TI - Two different modes of cyclin clb2 proteolysis during mitosis in Saccharomyces
cerevisiae.
AB - Sister chromatid separation and mitotic exit are triggered by the anaphase
promoting complex (APC/C) which is a multi-subunit ubiquitin ligase required for
proteolytic degradation of various target proteins. Cdc20 and Cdh1 are substrate
specific activators of the APC/C. It was previously proposed that Cdh1 is
essential for proteolysis of the yeast mitotic cyclin Clb2. We show that Clb2
proteolysis is triggered by two different modes during mitosis. A fraction of
Clb2 is degraded during anaphase in the absence of Cdh1. However, a second
fraction of Clb2 remains stable during anaphase and is degraded in a Cdh1
dependent manner as cells exit from mitosis. Most of cyclin Clb3 is degraded
independently of Cdh1. Our data imply that degradation of mitotic cyclins is
initiated by a Cdh1-independent mechanism.
PMID- 10692576
TI - TFIIA-TAF regulatory interplay: NMR evidence for overlapping binding sites on
TBP.
AB - TATA box binding protein (TBP)-promoter interaction nucleates assembly of the RNA
polymerase II transcription initiation complex. Transcription factor IIA (TFIIA)
stabilizes the TBP-promoter complex whereas the N-terminal domain of the largest
TAF(II) inhibits TBP-promoter interaction. We have mapped the interaction sites
on TBP of Drosophila TAF(II)230 and yeast TFIIA (comprising two subunits, TOA1
and TOA2), using nuclear magnetic resonance (NMR), and also report structural
evidence that subdomain II of the TAF(II)230 N-terminal inhibitory domain and
TFIIA have overlapping binding sites on the convex surface of TBP. Together with
previous mutational and biochemical data, our NMR results indicate that subdomain
II augments subdomain I-mediated inhibition of TBP function by blocking TBP-TFIIA
interaction.
PMID- 10692577
TI - Semi-synthetic Rab proteins as tools for studying intermolecular interactions.
AB - Rab GTPases play a key role in the regulation of membrane traffic.
Posttranslational geranylgeranylation is critical for their biological activity
and is conferred by a Rab geranylgeranyl transferase (RabGGTase). To study the
interactions between Rab proteins and RabGGTase, we used in vitro ligation
methodology to generate a fluorescent semi-synthetic Rab7 protein. The obtained
protein was functionally active and was used to demonstrate a micromolar affinity
interaction of Rab7 with the RabGGTase in the absence of Rab escort protein
(REP). This finding is consistent with an earlier proposed model according to
which RabGGTase possesses two independent weak binding sites for REP and Rab
proteins.
PMID- 10692578
TI - Olive oil phenolics are dose-dependently absorbed in humans.
AB - Olive oil phenolic constituents have been shown, in vitro, to be endowed with
potent biological activities including, but not limited to, an antioxidant
action. To date, there is no information on the absorption and disposition of
such compounds in humans. We report that olive oil phenolics, namely tyrosol and
hydroxytyrosol, are dose-dependently absorbed in humans after ingestion and that
they are excreted in the urine as glucuronide conjugates. Furthermore, an
increase in the dose of phenolics administered increased the proportion of
conjugation with glucuronide.
PMID- 10692579
TI - Slow formation of [3Fe-4S](1+) clusters in mutant forms of Desulfovibrio
africanus ferredoxin III.
AB - Desulfovibrio africanus ferredoxin III (Da FdIII) readily interconverts between a
7Fe and an 8Fe form with Asp-14 believed to provide a cluster ligand in the
latter form. To investigate the factors important for cluster interconversion in
Fe/S cluster-containing proteins we have studied two variants of Da FdIII
produced by site-directed mutagenesis, Asp14Glu and Asp14His, with cluster
incorporation performed in vitro. Characterisation of these proteins by
UV/visible, EPR and (1)H NMR spectroscopies revealed that the formation of the
stable 7Fe form of these proteins takes some time to occur. Evidence is presented
which indicates the [4Fe-4S](2+) cluster is incorporated prior to the [3Fe
4S](1+) cluster.
PMID- 10692580
TI - Dietary flavonoid and isoflavone glycosides are hydrolysed by the lactase site of
lactase phlorizin hydrolase.
AB - Lactase phlorizin hydrolase (LPH; EC 3.2.1.62) is a membrane-bound, family 1 beta
glycosidase found on the brush border of the mammalian small intestine. LPH,
purified from sheep small intestine, was capable of hydrolysing a range of
flavonol and isoflavone glycosides. The catalytic efficiency (k(cat)/K(m)) for
the hydrolysis of quercetin-4'-glucoside, quercetin-3-glucoside, genistein-7
glucoside and daidzein-7-glucoside was 170, 137, 77 and 14 (mM(-1) s(-1))
respectively. The majority of the activity occurred at the lactase and not
phlorizin hydrolase site. The ability of LPH to deglycosylate dietary
(iso)flavonoid glycosides suggests a possible role for this enzyme in the
metabolism of these biologically active compounds.
PMID- 10692581
TI - Characterization of the nuclear transport of a novel leucine-rich acidic nuclear
protein-like protein.
AB - We previously reported that the nuclear localization signal (NLS) peptides
stimulate the in vitro phosphorylation of several proteins, including a 34 kDa
protein. In this study, we show that this specific 34 kDa protein is a novel
murine leucine-rich acidic nuclear protein (LANP)-like large protein (mLANP-L).
mLANP-L was found to have a basic type NLS. The co-injection of Q69LRan-GTP or
SV40 T-antigen NLS peptides prevented the nuclear import of mLANP-L. mLANP-L NLS
bound preferentially to Rch1 and NPI-1, but not to the Qip1 subfamily of importin
alpha. These findings suggest that mLANP-L is transported into the nucleus by
Rch1 and/or NPI-1.
PMID- 10692582
TI - Human mast cells take up and hydrolyze anandamide under the control of 5
lipoxygenase and do not express cannabinoid receptors.
AB - Human mast cells (HMC-1) take up anandamide (arachidonoyl-ethanolamide, AEA) with
a saturable process (K(m)=200+/-20 nM, V(max)=25+/-3 pmol min(-1) mg protein(
1)), enhanced two-fold over control by nitric oxide-donors. Internalized AEA was
hydrolyzed by a fatty acid amide hydrolase (FAAH), whose activity became
measurable only in the presence of 5-lipoxygenase, but not cyclooxygenase,
inhibitors. FAAH (K(m)=5.0+/-0.5 microM, V(max)=160+/-15 pmol min(-1) mg protein(
1)) was competitively inhibited by palmitoylethanolamide. HMC-1 cells did not
display a functional cannabinoid receptor on their surface and neither AEA nor
palmitoylethanolamide affected tryptase release from these cells.
PMID- 10692583
TI - A novel rod-like opsin isolated from the extra-retinal photoreceptors of teleost
fish.
AB - We have isolated a novel opsin from the pineal complex of Atlantic salmon (Salmo
salar) and from the brain of the puffer fish (Fugu rubripes). These extra-retinal
opsins share approximately 74% identity at the nucleotide and amino acid level
with rod-opsins from the retina of these species. By PCR, we have determined that
the novel rod-like opsin is not expressed in the salmon retina, and the retinal
rod-opsin is not expressed in the salmon pineal. Phylogenetic analysis suggests
that the rod-like opsins arose from a gene duplication event approximately 205
million years ago, a time of considerable adaptive radiation of the bony fish. In
view of the large differences in the coding sequences of the pineal/brain rod
like opsins, their extra-retinal sites of expression, and phylogenetic position
we have termed these novel opsins 'extra-retinal rod-like opsins' (ERrod-like
opsins). We speculate that the differences between retinal rod-opsins and ERrod
like opsins have arisen from their differing photosensory roles and/or genetic
drift after the gene duplication event in the Triassic.
PMID- 10692584
TI - Identification of lysophospholipid receptors in human platelets: the relation of
two agonists, lysophosphatidic acid and sphingosine 1-phosphate.
AB - Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (Sph-1-P) are known as
structurally related bio-active lipids activating platelets through their
respective receptors. Although the receptors for LPA and Sph-1-P have been
recently identified in various cells, the identification and characterization of
ones in platelets have been reported only preliminarily. In this report, we first
investigated the distinct modes of LPA and Sph-1-P actions in platelet activation
and found that LPA functioned as a much stronger agonist than Sph-1-P, and high
concentrations of Sph-1-P specifically desensitized LPA-induced intracellular
Ca(2+) mobilization. In order to identify the responsible receptors underlying
these observations, we analyzed the LPA and Sph-1-P receptors which might be
expressed in human platelets, by RT-PCR. We found for the first time that Edg2,
4, 6 and 7 mRNA are expressed in human platelets.
PMID- 10692585
TI - A novel Drosophila serpin that inhibits serine proteases.
AB - Serpins define a large protein family in which most members function as serine
protease inhibitors. Here we report the results of a search for serpins in
Drosophila melanogaster that are potentially required for oogenesis or
embryogenesis. We cloned and sequenced ovarian cDNAs that encode six distinct
proteins having extensive sequence similarity to mammalian serpins, including
residues important in the serpin inhibition mechanism. One of these new serpins
in recombinant form inactivates, and complexes with, trypsin-like proteases in
vitro. To our knowledge, these results represent the first evidence for a serpin
in Drosophila that functions as a serine protease inhibitor.
PMID- 10692586
TI - Origin of the 'inactivation' of ribonuclease A at low salt concentration.
AB - The effect of salt concentration on catalysis by ribonuclease A (RNase A) has
been reexamined. At low salt concentration, the enzyme is inhibited by low-level
contaminants in common buffers. When an uncontaminated buffer system is used or
H12A RNase A, an inactive variant, is added to absorb inhibitory contaminants,
enzymatic activity is manifested fully at low salt concentration. Catalysis by
RNase A does not have an optimal salt concentration. Instead, k(cat)/K(M)10(9) M(
1)s(-1) for RNA cleavage at low salt concentration. These findings highlight the
care that must accompany the determination of meaningful salt-rate profiles for
enzymatic catalysis.
PMID- 10692587
TI - Cloning of a mouse glucocorticoid modulatory element binding protein, a new
member of the KDWK family.
AB - A mouse cDNA that encodes a nuclear DNA binding protein was identified by yeast
two-hybrid screening using the activation domain 2 of the nuclear receptor
coactivator TIF2 as a bait. BLAST analysis revealed that the identified cDNA
encodes a KDWK domain and contains sequences almost identical to three tryptic
peptides of rat GMEB-1 which together with the GMEB-2 heterodimeric partner binds
to the GME/CRE sequence (glucocorticoid modulatory element) of the tyrosine
aminotransferase (TAT) promoter. Mouse GMEB-1 is ubiquitously expressed in all
the tissues examined. In vitro translated mGMEB-1 bound specifically to GME
oligonucleotides, either alone or as a heterodimer with rGMEB-2. Transient
transfection experiments with TAT promoter reporter genes suggest a potential
role for mGMEB-1 as a transcriptional regulator of the TAT promoter.
PMID- 10692588
TI - Radiation inactivation analysis of H(+)-pyrophosphatase from submitochondrial
particles of etiolated mung bean seedlings.
AB - Radiation inactivation analysis was employed to determine the functional masses
of enzymatic activity and proton translocation of H(+)-pyrophosphatase from
submitochondrial particles of etiolated mung bean seedlings. The activities of
H(+)-pyrophosphatase decayed as a simple exponential function with respect to
radiation dosage. D(37) values of 6.9+/-0.3 and 7.5+/-0.5 Mrad were obtained for
pyrophosphate hydrolysis and its associated proton translocation, yielding
molecular masses of 170+/-7 and 156+/-11 kDa, respectively. In the presence of
valinomycin and 50 mM KCl, the functional size of H(+)-pyrophosphatase of
tonoplast was decreased, while that of submitochondrial particles remained the
same, indicating that they are two distinct types of proton pump using PP(i) as
their energy source.
PMID- 10692589
TI - Isolation of recombinant BMP receptor IA ectodomain and its 2:1 complex with BMP
2.
AB - Bone morphogenetic protein-2 (BMP-2) is a member of the transforming growth
factor beta superfamily which induces bone formation and regeneration, and
important steps during early embryonic development. BMP-2 signals via
oligomerization of type I and type II serine/threonine kinase receptors. We
report here expression of the extracellular domain of the human type IA receptor
for BMP-2 (BMPR-IA) in Escherichia coli. This soluble form of BMPR-IA (sBMPR-IA)
was purified employing a BMP-2 affinity column. Gel filtration experiments and
analysis of gel filtration fractions by polyacrylamide electrophoresis and
densitometry reveal that BMP-2 forms a defined 1:2 complex with sBMPR-IA that can
be purified and hopefully used for crystallization studies.
PMID- 10692590
TI - Identification of active site serine and histidine residues in Escherichia coli
outer membrane protease OmpT.
AB - Escherichia coli outer membrane protease OmpT has been characterised as a serine
protease based on its inhibitor profile, but serine protease consensus sequences
are absent. By site-directed mutagenesis we substituted all conserved serines and
histidines. Substitution of His(101) and His(212) by Ala, Asn or Gln resulted in
variant enzymes with 0.01 and 9-20% residual enzymatic activity towards a
fluorogenic pentapeptide substrate, respectively. The mutations S140A and S201A
did not decrease activity, while variants S40A and S99A yielded 0.5 and 0.2%
residual activities, respectively. When measured with a dipeptide substrate the
variant S40A demonstrated full activity, whereas variant S99A displayed at least
500-fold reduced activity. We conclude that Ser(99) and His(212) are essential
active site residues. We propose that OmpT is a novel serine protease with
Ser(99) as the active site nucleophile and His(212) as general base.
PMID- 10692591
TI - The C-terminal tetrapeptide HWFW of the Chlorella HUP1 hexose/H(+)-symporter is
essential for full activity and an alpha-helical structure of the C-terminus.
AB - C-terminal tails of plant hexose/H(+)-symporters of the major facilitator
superfamily contain a highly conserved motif of four amino acids: HWFW. A
deletion of these four amino acids in the Chlorella HUP1 protein leads to a
decrease in transport activity by a factor of 3-4. The mutated tail is highly
sensitive to trypsin; it does not show alpha-helical conformation in contrast to
the wild type C-terminal peptide with an alpha-helical content of at least 15%.
The production of monoclonal antibody 416B8 recognizing an epitope within the
central loop of HUP1 protein has been a prerequisite for the experiments
described.
PMID- 10692592
TI - A novel covalent modification of nitrogenase in a cyanobacterium.
AB - In extracts of the unicellular cyanobacterium Gloeothece, the Fe-protein of
nitrogenase can be separated by SDS-PAGE into two antigenically identifiable
components. Unlike the situation in photosynthetic bacteria such as
Rhodospirillum rubrum, these two forms do not arise from covalent modification of
the protein by ADP-ribosylation. Rather, the Fe-protein of Gloeothece nitrogenase
is subjected to modification by palmitoylation.
PMID- 10692593
TI - Deficiency of a STE20/PAK family kinase LOK leads to the acceleration of LFA-1
clustering and cell adhesion of activated lymphocytes.
AB - Lymphocyte-oriented kinase (LOK) is a member of the STE20/p21-activated kinase
(PAK) family and expressed predominantly in lymphoid organs. Generation of LOK
deficient mice revealed that the leukocyte-function-associated antigen (LFA
1)/intercellular adhesion molecules (ICAM)-mediated aggregation of mitogen
stimulated T cells was greatly enhanced in the absence of LOK. Though levels of
total LFA-1 and ICAMs as well as the active form of LFA-1 on T cell blasts were
comparable in the presence and absence of LOK, clustering of active LFA-1
detected by binding of soluble ICAM-1 was accelerated in the absence of LOK.
These results suggest that LOK is potentially involved in the regulation of LFA-1
mediated lymphocyte adhesion.
PMID- 10692594
TI - Chronic ethanol ingestion increases efficiency of oxidative phosphorylation in
rat liver mitochondria.
AB - The efficiency of oxidative phosphorylation was compared between rats chronically
fed with ethanol and controls. (i) Results showed that the liver mitochondria
state 4 respiratory rate was strongly inhibited, while the corresponding proton
motive force was not affected; (ii) the cytochrome oxidase content and activity
were decreased and (iii) the oxidative-phosphorylation yield was increased in the
ethanol exposed group. Furthermore, oxidative phosphorylation at coupling site II
was not affected by ethanol. Cytochrome oxidase inhibition by sodium-azide
mimicked the effects of ethanol intoxication in control mitochondria. This
indicates that the decrease in cytochrome oxidase activity induced by ethanol
intoxication directly increases the efficiency of oxidative phosphorylation.
PMID- 10692595
TI - Purification and characterisation of epithiospecifier protein from Brassica
napus: enzymic intramolecular sulphur addition within alkenyl thiohydroximates
derived from alkenyl glucosinolate hydrolysis.
AB - Epithiospecifier protein (ESP), a ferrous ion dependent protein, has a potential
role in regulating the release of elemental sulphur, nitriles, isothiocyanates
and cyanoepithioalkanes from glucosinolates. Two classes of ESP polypeptides were
purified with molecular masses of 39 and 35 kDa, and we show that the previously
reported instability was conditionally dependent. The 39 kDa polypeptide was made
up of two distinct isozymes (5.00, 5.14) whilst several were present for the 35
kDa form of ESP (5.40-5.66). An anti-ESP antibody reacted with both the 39 and 35
kDa ESP forms in Brassica napus and strongly with a polypeptide corresponding to
the 35 kDa ESP form in Crambe abyssinica, but did not detect any ESP in Sinapis
alba or Raphanus sativus. A cytochrome P-450 mediated iron dependent epoxidation
type mechanism is suggested for ESP.
PMID- 10692596
TI - Clinical notes
PMID- 10692597
TI - Trigeminal neuralgia: opportunities for research and treatment.
AB - Trigeminal neuralgia was the focus of a recent workshop convened by the National
Institute of Neurological Disorders and Stroke (NINDS) and the National Institute
of Dental and Craniofacial Research (NIDCR). The workshop brought together basic
scientists, clinicians, epidemiologists, and patient advocates. New research
directions for epidemiology, diagnosis and assessment, pain mechanisms, and
treatment were identified. (The workshop was held in Rockville MD on September
14, 1999, with financial support from NINDS, NIDCR, the NIH Office of Rare
Diseases, and the NIH Pain Research Consortium.)
PMID- 10692598
TI - Effects of antagonists to high-threshold calcium channels upon spinal mechanisms
of pain, hyperalgesia and allodynia.
AB - High-threshold voltage-dependent calcium channels enable calcium ions to enter
neurons upon depolarization and thereby influence synaptic mediator/receptor
systems, membrane excitability levels, second and third messenger concentration,
and gene expression. These phenomena underlie several processes including those
of normal nociception and of hyperalgesia and allodynia. The present article
deals with the role of spinal L-, N- and P/Q-type calcium channels in short
lasting nociception as well as in the hyperalgesia and allodynia elicited by
chemical irritants of peripheral nociceptors, inflammatory and mechanical lesions
of peripheral tissues, and lesions of peripheral nerves. The studies summarized
herein are based on the spinal delivery of specific antagonists to high-threshold
calcium channels, and reveal that blockade of L-type, P/Q-type and, particularly,
N-type channels can prevent, attenuate, or both, subjective pain as well as
primary and/or secondary hyperalgesia and allodynia in a variety of experimental
and clinical conditions.
PMID- 10692599
TI - Pain-related cerebral activation is altered by a distracting cognitive task.
AB - It has previously been suggested that the activity in sensory regions of the
brain can be modulated by attentional mechanisms during parallel cognitive
processing. To investigate whether such attention-related modulations are present
in the processing of pain, the regional cerebral blood flow was measured using
[(15)O]butanol and positron emission tomography in conditions involving both pain
and parallel cognitive demands. The painful stimulus consisted of the standard
cold pressor test and the cognitive task was a computerised perceptual maze test.
The activations during the maze test reproduced findings in previous studies of
the same cognitive task. The cold pressor test evoked significant activity in the
contralateral S1, and bilaterally in the somatosensory association areas
(including S2), the ACC and the mid-insula. The activity in the somatosensory
association areas and periaqueductal gray/midbrain were significantly modified,
i.e. relatively decreased, when the subjects also were performing the maze task.
The altered activity was accompanied with significantly lower ratings of pain
during the cognitive task. In contrast, lateral orbitofrontal regions showed a
relative increase of activity during pain combined with the maze task as compared
to only pain, which suggests the possibility of the involvement of frontal cortex
in modulation of regions processing pain.
PMID- 10692600
TI - Pain and allodynia/hyperalgesia induced by intramuscular injection of serotonin
in patients with fibromyalgia and healthy individuals.
AB - The aim of this study was to investigate the effect of injection of serotonin (5
HT) into the masseter muscle on pain and allodynia/hyperalgesia. Twelve female
patients with fibromyalgia (FM) and 12 age-matched female healthy individuals
(HI) participated in the study. The current pain intensity (CPI) and the pressure
pain threshold (PPT) of the superficial masseter muscles were assessed
bilaterally. 5-HT in one of three randomized concentrations (10(-3), 10(-5), 10(
7) M) or isotonic saline was then injected into either of the two masseter
muscles in a double-blind manner. After the injections the CPI and PPT were
recorded ten times during 30 min. The injections were repeated twice with the
other concentrations of 5-HT after 1 and 2 weeks, respectively. In the FM-group
there was a non-significant increase of CPI after injection that lasted during
the entire 30-min period irrespective of whether 5-HT or saline was injected.
Neither did the PPT change significantly. In the HI-group pain developed
significantly after injection irrespective of whether 5-HT or saline was
injected, but significantly more so after 5-HT at 10(-3) M than saline injection.
CPI decreased quickly and then remained on a very low level for most of the
experiment. 5-HT at both 10(-5) M and 10(-3) M caused a significantly greater
decrease of PPT than saline. In conclusion, our results show that 5-HT injected
into the masseter muscle of healthy female subjects elicits pain and
allodynia/hyperalgesia, while no such responses occur in patients with
fibromyalgia.
PMID- 10692601
TI - Immunolocalization of SNS/PN3 and NaN/SNS2 sodium channels in human pain states.
AB - The tetrodotoxin-resistant (TTX-R) voltage-gated sodium channel SNS/PN3 and the
newly discovered NaN/SNS2 are expressed in sensory neurones, particularly in
nociceptors. Using specific antibodies, we have studied, for the first time in
humans, the presence of SNS/PN3 and NaN/SNS2 in peripheral nerves, including
tissues from patients with chronic neurogenic pain. In brachial plexus injury
patients, there was an acute decrease of SNS/PN3- and NaN/SNS2-like
immunoreactivity in sensory cell bodies of cervical dorsal root ganglia (DRG)
whose central axons had been avulsed from spinal cord, with gradual return of the
immunoreactivity to control levels over months. In contrast, there was increased
intensity of immunoreactivity to both channels in some peripheral nerve fibers
just proximal to the site of injury in brachial plexus trunks, and in neuromas.
These findings suggest that the expression of these sodium channels in neuronal
cell bodies is reduced after spinal cord root avulsion injury in man, but that
pre-synthesized channel proteins may undergo translocation with accumulation at
sites of nerve injury, as in animal models of peripheral axotomy. The latter may
contribute to positive symptoms, as our patients all showed a positive Tinel's
sign. Nerve terminals in distal limb neuromas and skin from patients with chronic
local hyperalgesia and allodynia all showed marked increases of SNS/PN3
immunoreactive fibers, but little or no NaN/SNS2-immunoreactivity, suggesting
that the former may be related to the persistent hypersensitive state. Axonal
immunoreactivity to both channels was similar to control nerves in sural nerve
biopsies in a selection of neuropathies, irrespective of nerve inflammation,
demyelination or spontaneous pain, including a patient with congenital
insensitivity to pain. Our studies suggest that the best target for SNS/PN3
blocking agents is likely to be chronic local hypersensitivity.
PMID- 10692602
TI - Age-related differences in the time course of capsaicin-induced hyperalgesia.
AB - The effect of age on hyperalgesia, one of the most common signs of injury, has
not been previously examined in humans. A psychophysical study was conducted in
10 young (26.9+/-4.6 years) and 10 older (79. 0+/-5.7 years) healthy volunteers
to investigate the effect of age on the development of hyperalgesia induced by
topical application of capsaicin (0.1 ml, 5 mg/ml). The capsaicin patch (diameter
2 cm) was applied for 1 h. The intensity of capsaicin-induced spontaneous
sensation, mechanical pain threshold, area of flare, heat and punctate
hyperalgesia were measured hourly for 3 h after the application. Older adults
took a longer period to report first pain. There was no age effect on the
magnitude of spontaneous sensation, flare size and area of heat hyperalgesia. The
area of heat hyperalgesia rapidly decreased over time in both age groups. In
marked contrast, the area of punctate hyperalgesia and associated reduction in
the mechanical pain threshold were maintained in older adults over the entire 3 h
test period, but resolved rapidly in young adults. We conclude that, given the
same intensity of noxious stimulation, older adults display a similar magnitude
of hyperalgesia as younger persons. However, once initiated, punctate
hyperalgesia appears to resolve more slowly in older people. This finding may
indicate age differences in the plasticity of spinal cord neurons following an
acute injury.
PMID- 10692603
TI - Intrathecal lithium reduces neuropathic pain responses in a rat model of
peripheral neuropathy.
AB - We tested the ability of lithium (Li(+)) to block heat hyperalgesia, cold
allodynia, mechanical allodynia and mechanical hyperalgesia in rats
experimentally subjected to painful peripheral neuropathy. Chronic constrictive
injury (CCI) to the sciatic nerve induced persistent hyperalgesia and allodynia.
Intrathecal injection of Li(+) (2.5-40 micromol) into the region of lumbar
enlargement dose-dependently reduced heat hyperalgesia, cold allodynia and
mechanical allodynia for 2-6 h after injection, but had no effect on mechanical
hyperalgesia. Li(+) had no significant effect on responses from control and sham
operated animals. Intrathecal injection of myo-inositol (2.5 mg) significantly
reversed both the anti-hyperalgesic and anti-allodynic effect of Li(+). These
findings suggest that intrathecal Li(+) suppresses neuropathic pain response in
CCI rats through the intracellular phosphatidylinositol (PI) second messenger
system in spinal cord neurons. Lithium (Li(+)) has already found widespread
clinical application; these results suggest that its therapeutic utility may be
extended to include treatment of neuropathic pain syndromes resulting from
peripheral nerve injury.
PMID- 10692604
TI - Morphine and NMDA receptor antagonism reduce c-fos expression in spinal
trigeminal nucleus produced by acute injury to the TMJ region.
AB - Pain management in temporomandibular disorders (TMDs) often involves
pharmacotherapy; however, the site of action for drugs that reduce TMD pain is
not known. To determine possible central neural targets of analgesic drugs
relevant in TMD pain, morphine or the N-methyl-D-aspartate receptor antagonist,
MK-801, was given alone or in combination prior to TMJ injury. The number of
neurons expressing the immediate early gene, c-fos, was quantified in the lower
brainstem and upper cervical spinal cord as an index of neural activation. It was
hypothesized that those neuronal groups most necessary for the sensory
discriminative aspects of acute TMJ injury should display the greatest reduction
in c-fos expression after drug treatment. Barbiturate-anesthetized male rats were
given morphine or MK-801 15 min prior to injection of mustard oil into the TMJ
region. Morphine given centrally (i.c.v.) or peripherally (i.v.) caused a marked
dose-related reduction in Fos-like immunoreactivity (Fos-LI) in laminae I-II at
the middle portions of subnucleus caudalis (mid-Vc) and at the subnucleus
caudalis/upper cervical spinal cord (Vc/C2) transition. Higher doses of morphine
also reduced Fos-LI in the dorsal paratrigeminal region (dPa5) and at the
subnucleus interpolaris/subnucleus caudalis (Vi/Vc-vl) transition. MK-801 given
i.v. reduced Fos-LI only in laminae I-II at the Vc/C2 transition. Combined
subthreshold doses of morphine and MK-801 reduced c-fos expression in the dPa5,
mid-Vc, and the Vc/C2 transition region, below that predicted from the effects of
either drug alone. These results suggest that neurons in laminae I-II of the mid
Vc and Vc/C2 transition and, to a lesser extent, in the dPa5 region play a
critical role in mediating the sensory and/or reflex aspects of pain after acute
injury to the TMJ region.
PMID- 10692605
TI - Differences between the sexes in post-surgical pain.
AB - It has been shown that women have a lower pain threshold and lower tolerance to
some forms of experimental pain then men. However, the evidence that clinical
pain is perceived differently by the two sexes is not yet as strong. The
placement of intraoral implants is a highly controlled surgical procedure that we
have used to investigate this possibility. Forty-eight edentulous (without teeth)
subjects (27 females), aged from 35 to 63 years, received two titanium implants
in the anterior mandible under local anesthesia. After the surgery, subjects
completed a pain diary three times each day, rating pain intensity and
unpleasantness on 100 mm visual analog scales (VAS). Once a day, they chose
verbal descriptors from the McGill Pain Questionnaire (MPQ). Age of subjects,
duration of surgery, the amount of local anesthetic used and the amount of pain
medication taken were not statistically different for the two groups (P>/=0.32).
Results showed that the senior surgeon produced significantly less pain than a
4th year resident (P=0.04). Although there were no significant differences
between sexes for mean daily ratings of intensity or unpleasantness over time
(P>/=0.10), most women experienced the highest intensity of pain during the day,
while most men had higher pain in the evening (P=0.025). Also, the relative
unpleasantness (unpleasantness/intensity ratio) increased significantly with time
for males, but not for females (P=0.016). Males and females did not differ in the
total number of words chosen from the MPQ (P=0.61), or in the averaged Pain
Rating Index (PRI) (P=0.53). However, women used significantly more evaluative
words than men (P=0.04), suggesting that woman found the overall intensity
greater. These results indicate that women find post-surgical pain more intense
than males, but that men are more disturbed than women by low levels of pain that
last several days.
PMID- 10692606
TI - Sociodemographic correlates of tooth pain among adults: United states, 1989.
AB - This study presents the sociodemographic distribution of tooth pain and the
dental care utilization of affected individuals. Data for adults 20 years of age
and over were derived from the 1989 National Health Interview Survey's
supplements on dental health, orofacial pain, and health insurance (n=33073).
Prevalence of tooth pain by socioeconomic status (SES) and adjusted odds ratios
of reporting tooth pain in the past 6 months and of having no dental visits in
the past year among persons reporting pain in the previous 6 months were computed
taking into account the survey's complex sample design. Tooth pain in the past 6
months was reported by 14.5% (95% CI 14.0, 15.0) of adults aged 20-64 years and
by 7.0% (95% CI 6.1, 7.9) of those 65 years and over. In the younger age group,
tooth pain was more likely to be reported by those with low SES than it was by
those with high SES; in the older age group, tooth pain was more likely reported
by non-Hispanic blacks than it was by non-Hispanic whites or Hispanics. Of those
reporting pain, younger and older non-Hispanic blacks and persons with lower
educational attainment were more likely not to have a dental visit in the
previous 12 months. Persons with low SES characteristics were more likely to
report tooth pain and to endure their pain without the benefit of dental care
while the pain was present.
PMID- 10692607
TI - Sex differences and phases of the estrous cycle alter the response of spinal cord
dynorphin neurons to peripheral inflammation and hyperalgesia.
AB - The neuromodulatory interactions of sex steroids with the opioid system may
result in sex differences in pain and analgesia. Dynorphin is an endogenous kappa
opioid peptide that is upregulated in an animal model of peripheral inflammation
and hyperalgesia and is possibly regulated by circulating levels of sex steroids.
The present study compared behavioral responses of male, cycling female, and
gonadectomized Sprague-Dawley rats in a model of persistent pain. Cycling female
rats were behaviorally tested over a 14-day period, and their estrous cycles were
monitored by daily vaginal smears. Thermal hyperalgesia was measured by paw
withdrawal latencies taken prior to and 24-72 h after rats received a unilateral
hindpaw injection of complete Freund's adjuvant (CFA). Prior to CFA
administration, there was no significant difference in paw withdrawal latencies
between male rats, cycling female rats, and ovariectomized female rats. Following
CFA administration, female rats in proestrus exhibited significantly increased
hyperalgesia compared with male rats, ovariectomized female rats, and female rats
in other estrous stages (P=0.05). Levels of spinal preprodynorphin (PPD) mRNA
induction in the L4-L5 segments were assessed by Northern blot analysis. PPD mRNA
expression ipsilateral to the injected paw was significantly higher in female
rats in diestrus (P=0.05) and proestrus (P=0.01) compared with rats in estrus
and intact male rats. Ovariectomized rats had significantly higher levels of PPD
mRNA expression compared with intact male rats (P=0.05). However, castrated
male rats had significantly lower levels of PPD mRNA expression than intact male
rats (P=0.05). PPD mRNA expression was not altered on the contralateral side of
the spinal cord in any group. These results suggest a hormonal regulatory
influence on the response of spinal cord dynorphin neurons to chronic
inflammation and furthermore, that the association of the endocrine and opioid
systems have the ability to influence an animal's sensitivity to pain.
PMID- 10692608
TI - A comparative trial of botulinum toxin type A and methylprednisolone for the
treatment of myofascial pain syndrome and pain from chronic muscle spasm.
AB - Myofascial pain syndrome (MPS) is a common illness, characterised by acute or
chronic focal pain, muscle stiffness and fatigue. The pathophysiology of MPS
remains unclear. Previous preliminary studies have demonstrated therapeutic
efficacy of the muscle relaxant botulinum toxin type A (BTX-A) in the treatment
of MPS. A single-centre, randomised trial compared the effects of BTX-A with the
steroid methylprednisolone (both administered intramuscularly with 0.5%
bupivacaine), in 40 patients suffering from chronic myofascial pain in the
piriformis, iliopsoas or scalenus anterior muscles. Thirty days after receiving
an injection of either BTX-A or steroid followed by post-injection physiotherapy,
pain severity had decreased significantly from baseline in both treatment groups,
with no significant difference between the two treatment groups. However, the
baseline pain score was significantly higher in the BTX-A treatment group
compared with the steroid group (7.9 vs. 7.3), and the reduction in pain score
between baseline and 30 days post-injection was greater in the BTX-A group
compared with the steroid group (-3.9 vs. -3.5; P=0.06). At 60 days post
injection, the pain severity score for the BTX-A-treated patients was
statistically significantly lower than the pain score for the steroid-treated
population (2.3 vs. 4.9). Furthermore, the reduction in pain score in the BTX-A
group at 60 days post-injection was greater than at 30 days (-5.5 vs. -3.9),
whereas the effect of the steroid had begun to wane. These results indicate the
superior efficacy of BTX-A over conventional steroid treatment in patients
suffering from MPS, when combined with appropriate physiotherapy.
PMID- 10692609
TI - Development and validation of a questionnaire to assess disabling foot pain.
AB - This study outlines the design and validation of a new self-administered
instrument for assessing foot pain and disability. The 19-item questionnaire was
tested on 45 rheumatology patients, 33 patients who had attended their general
practitioner with a foot-related problem and 1000 responders to a population
survey of foot disorders. Levels of reported disability were found to be greatest
for rheumatology patients and least for community subjects. In addition, the
instrument was able to detect differences in disability levels reported by
community subjects who did and did not consult with a health care professional
and those who did and did not have a history of past and current foot pain. A
good level of agreement was found when items on the questionnaire were compared
with similar items on the ambulation sub-scale of the Functional Limitation
Profile questionnaire. A Cronbach's alpha value of 0.99 and item-total
correlation values between 0.25 and 0.62 confirmed the internal consistency of
the instrument. Finally the results of a principal components analysis identified
three constructs that reflected disabilities that are associated with foot pain:
functional limitation, pain intensity and personal appearance. The design of the
foot disability questionnaire makes it a suitable instrument for assessing the
impact of painful foot conditions in both community and clinical populations.
PMID- 10692610
TI - Do beliefs, coping, and catastrophizing independently predict functioning in
patients with chronic pain?
AB - Physical and psychosocial disability in patients with chronic pain have been
shown to be associated with patients' pain-related beliefs, tendency to
catastrophize, and pain coping strategy use. However, little is known about
whether beliefs, catastrophizing, and coping strategies are independently
associated with patient adjustment. Identification of specific beliefs, cognitive
responses, and coping strategies strongly and independently associated with
physical and psychosocial functioning would suggest the importance of targeting
those variables for modification in treatment. One hundred sixty-nine patients
entering a multidisciplinary pain treatment program completed measures of pain,
beliefs, coping, catastrophizing, physical disability, and depression. Principal
components analyses were used to create belief and coping components, which were
then entered in multiple regression analyses predicting physical disability and
depression. Belief scores significantly and independently predicted both physical
disability and depression, after controlling for age, sex, pain intensity,
catastrophizing, and coping. Coping scores significantly and independently
predicted physical disability, but not depression, whereas catastrophizing
independently predicted depression, but not physical disability. These findings
suggest the importance of targeting specific pain-related beliefs and coping
strategies, as well as catastrophizing, for modification in the treatment of
patients with chronic pain.
PMID- 10692611
TI - Differences in pain expression between male and female newborn infants.
AB - The study of neonatal gender differences in pain expression is important since
neonatal pain behavior occurs prior to any learned reaction pattern. The
objective of this study was to verify the presence of gender differences in pain
expression in preterm and term newborn infants. Sixty-five consecutive neonates
(37 female and 28 male infants) with gestational age between 28 and 42 weeks and
with 25-120 h of life were studied. Healthy term neonates required a capillary
puncture for PKU screening and clinically stable premature infants needed a
capillary puncture for glucose dosage. The Neonatal Facial Coding System (NFCS)
and the Neonatal Infant Pain Scale (NIPS) were evaluated at bedside prior to the
puncture, when patients were at rest, during foot heating; during capillary
puncture; and at 1, 3, and 5 min after heel lancing. Results were analyzed by
repeated-measures ANOVA followed by the Multiple Comparison Method of Bonferroni.
A significant difference among the mean NFCS scores during the six study periods
was noted for the whole group of neonates (P<0.000001). Also, a significant
interaction between the NFCS score profile in female and male neonates at the
different study periods was observed (P=0.025). Regarding NIPS, ANOVA showed only
a significant difference among the mean NIPS scores during the six study periods
for the whole group of neonates (P<0.000001). No significant interactions between
gestational age and time, nor between gestational age and gender were noted, for
both NFCS and NIPS. In conclusion, recently born female neonates of all
gestational ages expressed more facial features of pain than male infants, during
the capillary puncture and 1 min afterwards. Maybe differences in pain processing
and/or pain expression among genders may explain this finding.
PMID- 10692612
TI - Synergistic interactions between two alpha(2)-adrenoceptor agonists,
dexmedetomidine and ST-91, in two substrains of Sprague-Dawley rats.
AB - Several lines of evidence indicate that the antinociception produced by
intrathecal administration of the alpha(2)-adrenoceptor agonists dexmedetomidine
or ST-91 is mediated by different subtypes of the alpha(2)-adrenoceptor. We
recently provided additional pharmacologic evidence for this idea, as well as for
differences in the function of these receptors between Harlan and Sasco rats, two
widely-used outbred substrains of Sprague-Dawley rat. The present study used
isobolographic analysis to further characterize the receptors at which
intrathecally administered ST-91 and dexmedetomidine act in these two substrains.
The rationale for these studies derives from the assumption that if
dexmedetomidine and ST-91 act as agonists at the same receptor then they should
interact in an additive manner. However, if they interact in a supra-additive
manner, then they must act at different subtypes of the alpha(2)-adrenoceptor. In
the tail-flick test, the dose-effect relationship for a 1:3 mixture of
dexmedetomidine and ST-91 was shifted significantly to the left of the
theoretical dose-additive line in both Harlan and Sasco Sprague-Dawley rats. A
similar finding was made in the hot-plate test despite the fact that the dose
response characteristics of the agonists were different in this test. Thus, in
Harlan rats, in which ST-91 is a full agonist and dexmedetomidine is essentially
inactive, the dose-effect relationship for the mixture of dexmedetomidine and ST
91 was shifted far to the left of the dose-additive line. Similarly, in Sasco
rats, in which ST-91 is a partial agonist and dexmedetomidine is inactive, co
administration of the two agonists also shifted the dose-response relationship to
the left of the dose-additive line. The consistent finding that these two
alpha(2)-adrenoceptor agonists interact in a supra-additive manner provides
strong evidence that dexmedetomidine and ST-91 produce antinociception by acting
at different alpha(2)-adrenoceptor subtypes in the spinal cord. This conclusion
is consistent with the earlier proposal that dexmedetomidine acts predominantly
at alpha(2A)-adrenoceptors whereas ST-91 acts predominantly at non-alpha(2A)
adrenoceptors. Recent anatomical evidence indicates that these non-alpha(2A)
adrenoceptors may be of the alpha(2C) type. The synergistic combination of an
alpha(2A)- and an alpha(2C)-adrenoceptor agonist may provide a unique and highly
effective drug combination for the treatment of pain without the sedation
produced by an equianalgesic dose of a single alpha(2)-adrenoceptor agonist.
PMID- 10692613
TI - Nociceptive and inflammatory effects of subcutaneous TNFalpha.
AB - Tumor necrosis factor alpha (TNF) is a potent pro-inflammatory cytokine that
produces pain and hyperalgesia following injection. Its algesic effects are due
to sensitizing actions on nociceptive primary afferents and to the upregulation
of other pro-inflammatory and algesic proteins. In anesthetized rats, we
investigated the effect of subcutaneously injected TNF on background activity and
mechanical sensitivity of C nociceptors of the sural nerve, as well as its
effects on cutaneous plasma extravasation. TNF sensitized C nociceptors dose
dependently; the optimal dose (5 ng) lowered threshold in 66.7% of the tested
fibers. This sensitization occurred within 30 min and could last for 2 or more
hours. Injected TNF had no effect on Abeta mechanoreceptive fibers. In addition,
TNF evoked ongoing activity in 14% of C nociceptors and caused significant and
dose-related increases in vascular permeability in glabrous skin. Our data
suggest that TNF released during disease or after tissue injury participates in
the generation of hyperalgesia and inflammation.
PMID- 10692614
TI - Brainstem pain modulating circuitry is sexually dimorphic with respect to mu and
kappa opioid receptor function.
AB - We have previously shown that activation of kappa opioid receptors within the
rostral ventral medulla in lightly anesthetized rats has an anti-mu opioid
analgesic action in male rats. Microinjections of the kappa opioid receptor
agonist, U69593, attenuated the increase in tail-flick latency produced by
activation of mu opioid receptors located within the ventrolateral periaqueductal
gray. There are sex differences in the pain modulating potency of opioid
analgesics, including kappa opioid agonists. In the present study, we examined
whether activation of kappa opioid receptors within the rostral ventral medulla
in lightly anesthetized female rats produces an anti-mu opioid analgesic effect
similar to that found in males. We found that in the RVM the same dose of kappa
opioid receptor agonist that reduces mu receptor-mediated increase in tail-flick
latency in male rats produces a moderate increase in tail-flick latency in female
rats. Additionally, we discovered that female rats are significantly more
sensitive to the mu opioid agonist, DAMGO, injected into the ventrolateral
periaqueductal gray. The results indicate that these two brain structures, which
mediate the analgesic effects of opioids, are sexually dimorphic with regard to
opioid receptor function.
PMID- 10692616
TI - Quantitative estimation of rare adverse events which follow a biological
progression: a new model applied to chronic NSAID use.
AB - Randomised controlled trials (RCTs) alone are unlikely to provide reliable
estimates of the incidence of rare events because of their limited size. Cohort,
case control, and other observational studies have large numbers but are
vulnerable to various kinds of bias. Wanting to estimate the risk of death from
bleeding or perforated gastroduodenal ulcers with chronic usage of non-steroidal
anti-inflammatory drugs (NSAIDs) with greater precision, we developed a model to
quantify the frequency of rare adverse events which follow a biological
progression. The model combined data from both RCTs and observational studies. We
searched systematically for any report of chronic (>/=2 months) use of NSAIDs
which gave information on gastroduodenal ulcer, bleed or perforation, death due
to these complications, or progression from one level of harm to the next.
Fifteen RCTs (19364 patients exposed to NSAIDs for 2-60 months), three cohort
studies (215076 patients redeeming a NSAID prescription over a 3-12 month
period), six case-control studies (2957 cases) and 20 case series (7406), and
case reports (4447) were analysed. In RCTs the incidence of bleeding or
perforation in 6822 patients exposed to NSAIDs was 0.69%; two deaths occurred. Of
11040 patients with bleeding or perforation with or without NSAID exposure across
all reports, 6-16% (average 12%) died; the risk was lowest in RCTs and highest in
case reports. Death from bleeding or perforation in all controls not exposed to
NSAIDs occurred in 18 out of 849489 (0.002%). From these numbers we calculated
the number-needed-to-treat for one patient to die due to gastroduodenal
complications with chronic (>/=2 months) NSAIDs as 1/((0.69x?6-16%, average 12%?)
0.002%))=909-2500 (average 1220). On average 1 in 1200 patients taking NSAIDs for
at least 2 months will die from gastroduodenal complications who would not have
died had they not taken NSAIDs. This extrapolates to about 2000 deaths each year
in the UK.
PMID- 10692615
TI - Effects of the I(1) imidazoline/alpha(2)-adrenergic receptor agonist moxonidine
in comparison with clonidine in the formalin test in rats.
AB - Moxonidine is a mixed I(1) imidazoline/alpha(2)moxonidine=morphine. The I(1)
imidazoline preferring antagonist efaroxan produced a dose-dependent antagonism
of both moxonidine (5.0 mg/kg) and clonidine (0.5 mg/kg). In addition, the
alpha(2)-adrenergic receptor antagonist yohimbine produced a dose-related
antagonism of moxonidine, but only partially antagonized clonidine. Prazosin
failed to block the effects of either moxonidine or clonidine, indicating a lack
of involvement of alpha(1) as well as alpha(2B) and alpha(2C) receptors. The
present results suggest that alpha(2)-adrenergic receptors play an important role
in mediating the effects of moxonidine in producing antinociception in the
formalin test. Further, the present results demonstrate that the mechanism of
action of moxonidine and clonidine differ in that clonidine, but not moxonidine,
produces an antinociceptive effect through a yohimbine-insensitive mechanism in
the formalin test.
PMID- 10692617
TI - Periaqueductal gray matter metabotropic glutamate receptors modulate formalin
induced nociception.
AB - The role played by periaqueductal gray (PAG) matter metabotropic glutamate
receptors (mGluRs) in the modulation of persistent noxious stimulation was
investigated in mice. The formalin test was used as a model of persistent pain.
Intra-PAG microinjections of (S)-3, 5-DHPG (25 and 50 nmol/mouse) and L-CCG-I (30
and 60 nmol/mouse), agonists of group I and group II mGluRs, respectively,
decreased the nociceptive response (-92+/-6% and -89+/-8%, respectively) during
the late phase. No change of the early nociceptive phase was observed after (S)
3,5-DHPG or L-CCG-I treatments. These effects were antagonized by a pretreatment
with CPCCOEt (40 nmol/mouse) and (2S)-alpha-EGlu (30 nmol/mouse). CPCCOEt is a
selective antagonist of group I mGlu receptors, while (2S)-alpha-EGlu is an
antagonist of group II. Intra-PAG microinjections of L-SOP (60 and 120
nmol/mouse), a selective agonist of group III mGluRs, induced an increase of the
nociceptive response (+95+/-7%) during the late hyperalgesic phase. (R,S)-alpha-M
SOP (70 nmol/mouse), a selective antagonist of group III mGluRs, completely
antagonized the L-SOP-induced effect. These results show that PAG mGluRs
participate in modulating the late hyperalgesic behaviours induced by formalin.
It seems, therefore, possible that group I and group II mGluRs positively
modulate PAG antinociceptive descending pathway following a persistent noxious
stimulation, while group III mGluRs modulate it negatively.
PMID- 10692618
TI - The impact of HIV infection on primary headache. Unexpected findings from
retrospective, cross-sectional, and prospective analyses.
AB - Headache is one of the most important factors influencing the quality of life in
patients infected with the human immunodeficiency virus type 1 (HIV). However,
only symptomatic headache but not changes or primary headache types during HIV
infection have been studied to date. Therefore, we aimed to determine the impact
of an HIV infection on frequency and semiology of different primary headache
types. Patients with confirmed HIV type 1 infection underwent a neurological
examination, neuroimaging or EEG, and a standardized interview. Time pattern and
symptoms of headaches (cross-sectional analysis), changes of headaches
preexisting to their infection (longitudinal retrospective analysis), and changes
of primary headaches during a 2-year follow-up (longitudinal prospective
analysis) were evaluated as were the correlations between these headache patterns
and different markers of HIV infection. One hundred thirty-one consecutive HIV
infected patients without evidence of a cerebral manifestation except mild
encephalopathy were enrolled. The point prevalence of migraine was 16.0%
(confidence interval (CI) 10.1-25.4%), of headache with a semiology of tension
type headache 45.8% (CI 33.7-62.2%), and of other headache types 6.1% (CI 3.0
12.5%). During the natural course of infection, the migraine frequency
significantly decreased in the retrospective and in the prospective analyses,
whereas the frequency of the headache with a semiology of tension-type headache
significantly increased in all three analyses. In 20% of all patients, the
tension-type headache could be considered as symptomatic due to the infection but
not due to focal or general cerebral lesions. Changes of primary headache were
significantly associated with different stages of the infection and with the
presence of mild encephalopathy but not with antiretroviral treatment or CD4 cell
count. HIV infection seems to be associated with a progressive decrease in
migraine frequency and intensity which probably is related to the immunological
state of the patients. Tension-type headache becomes more frequent during HIV
infection. However, this can in part be related to secondary headache caused by
the HIV in less than 50% of patients with tension-type headache. The progressing
immunological deficiency of HIV-infected patients seems to influence pain
processing of primary headache types in different ways.
PMID- 10692619
TI - Perceived pain before and after three exercise programs--a controlled clinical
trial of women with work-related trapezius myalgia.
AB - The effect of exercise on neck-shoulder pain was studied in 103 women with work
related trapezius myalgia randomized into three exercise groups and a control
group. One group trained strength, the second muscular endurance and the third co
ordination. The exercise groups met three times weekly for 10 weeks. Pain
assessment was made on three visual analogue scales, indicating pain at present,
pain in general and pain at worst. Pain thresholds were measured in the trapezius
muscle with a pressure algometer. A pain drawing was completed. The rated pain
decreased significantly (P<0.05) on the VAS describing pain at worst in the
strength and endurance groups. Pressure sensitivity decreased significantly
(P<0.05) in four triggerpoints in the exercise groups. No changes were seen in
the extent of painful body area in any group. Comparison of exercisers (n=82) and
controls (n=21) showed significantly larger pain reductions on VAS pain at
present and VAS pain at worst among exercisers. All three exercise programs
showed similar decreases of pain which indicates that the type of exercise is of
less importance to achieve pain reduction.
PMID- 10692620
TI - The cognitive and psychomotor effects of morphine in healthy subjects: a
randomized controlled trial of repeated (four) oral doses of dextropropoxyphene,
morphine, lorazepam and placebo.
AB - Ten healthy subjects (four male) of mean age 31 years (range 25-40) took part in
a randomized double-blind four-way crossover study to examine the cognitive and
psychomotor effects of repeated oral doses of dextropropoxyphene and morphine.
Four treatments were compared: dextropropoxyphene napsylate 100 mg, morphine
sulphate 10 mg, lorazepam 0.5 mg and placebo. Four doses of each drug were given
at 4-h intervals to each subject on four separate study days at least 1 week
apart. Cognitive function was assessed using choice reaction time, number
vigilance, memory scanning, immediate and delayed word recall, word recognition,
picture recognition, critical flicker fusion threshold (CFFT) and subjective
measures of alertness, calmness and contentment. Lorazepam impaired the speed of
responding on all tasks in which speed was recorded (except digit vigilance) and
increased subjective ratings of calmness. Morphine had one major effect, which
was to increase the accuracy of responding on the choice reaction time task, at
every assessment. Morphine produced some sporadic effects in other tests and an
increase in subjective calmness. Dextropropoxyphene impaired performance on
choice reaction time and picture recognition. These data show that oral morphine
may enhance performance in some measures of cognitive function, whereas
dextropropoxyphene (in usual therapeutic doses) seems more likely to cause
impairment. Neither opioid has substantial effects on cognition and psychomotor
function compared with lorazepam.
PMID- 10692621
TI - Low-dose lidocaine reduces secondary hyperalgesia by a central mode of action.
AB - Sodium channel blockers are approved for intravenous administration in the
treatment of neuropathic pain states. Preclinical studies have suggested
antihyperalgesic effects on the peripheral as well as the central nervous system.
The objective of this study was to determine mechanisms of action of low-dose
lidocaine in experimental induced, secondary hyperalgesia. In a first
experimental trial, participants (n=12) received lidocaine systemically (a bolus
injection of 2 mg/kg in 10 min followed by an intravenous infusion of 2 mg kg(
1)h(-1) for another 50 min). In a second trial, a modified intravenous regional
anesthesia (IVRA) was administered to exclude possible central analgesic effects.
In one arm, patients received an infusion of 40 ml lidocaine, 0.05%; in the other
arm 40 ml NaCl, 0.9%, served as a control. In both trials capsaicin, 20
microgram, was injected intradermally and time course of capsaicin-induced pain,
allodynia and hyperalgesia as well as axon reflex flare was determined. The
capsaicin-induced pain was slightly reduced after systemic and regional
application of the anesthetic. The area of pin-prick hyperalgesia was
significantly reduced by systemic lidocaine, whereas the inhibition of
hyperalgesia was absent during regional administration of lidocaine. In contrast,
capsaicin-induced flare was significantly decreased after both treatments. We
conclude that systemic lidocaine reduces pin-prick hyperalgesia by a central mode
of action, which could involve blockade of terminal branches of nociceptors. A
possible role for tetrodotoxin resistant sodium channels in the antihyperalgesic
effect of low-dose lidocaine is discussed.
PMID- 10692622
TI - Avoidance versus focused attention and the perception of pain: differential
effects for men and women.
AB - The aim of the current investigation was to compare the effects of two different
attentional strategies (focused vs. avoidance) on how males and females respond
to experimentally induced pain. One hundred healthy adults were instructed to
either attend towards or away from cold pressor pain. Measures of pain tolerance,
pain threshold and recovery were taken, as were self-report measures of sensory
and affective pain experiences. As expected, gender was found to moderate
tolerance to pain: males were found to be more tolerant to cold pressor pain than
females. With respect to the self-report measures, males reported less sensory
pain when they attended toward the pain than when they avoided it. However, a
similar effect was not found in women, suggesting that attentional focusing may
only be a useful strategy for males. These results are discussed in light of
previous research.
PMID- 10692624
TI - The role of 5-HT(1A)-receptors in fentanyl-induced bulbospinal inhibition of a
spinal withdrawal reflex in the rabbit.
AB - The sural to gastrocnemius withdrawal reflex is inhibited after injection of the
OP(3) (micro)-receptor-selective opioid fentanyl into the fourth ventricle of
decerebrated rabbits. This effect is abolished by complete section of the spinal
cord but not by the selective alpha(2)-adrenoceptor antagonist RX 821002 (Clarke
RW, Parry-Baggott C, Houghton AK, Ogilvie J. The involvement of bulbo-spinal
pathways in fentanyl-induced inhibition of spinal withdrawal reflexes in the
decerebrated rabbit. Pain 1998;78:197-207). We have now investigated the role of
5-HT(1A) receptors in mediating the descending inhibition activated by
intraventricular fentanyl. In the control state, intraventricular fentanyl (3-30
microgram/kg) inhibited gastrocnemius reflex responses to a median of 34% of pre
drug levels. After intrathecal administration of the selective 5-HT(1A) receptor
antagonist WAY-100635 (100 microgram), fentanyl reduced reflex responses to 83%
of pre-fentanyl values, significantly less inhibition than in the control state.
In a separate group of experiments, intravenous fentanyl (0.3-30 microgram/kg)
depressed the sural-gastrocnemius reflex to 17% of pre-drug controls. This
inhibition was not affected by intrathecal WAY-100635 (100 microgram), but
combined administration of the 5-HT(1A) antagonist with RX 821002 (100 microgram)
significantly reduced the effectiveness of i.v. fentanyl. After the highest dose
reflexes were 37% of pre-fentanyl levels. These data show that the bulbospinal
inhibition activated by fentanyl is mediated, at least in part, by activation of
spinal 5-HT(1A) receptors. That blockade of these receptors failed to influence
the inhibition induced by i.v. fentanyl might be taken to mean that the brain
stem action of fentanyl does not contribute significantly to the systemic actions
of this opioid. A more probable explanation is that, in the preparation used in
the present study, the bulbospinal and direct spinal actions of fentanyl occlude
each other to produce an overall inhibition that is less than the sum of the two
effects.
PMID- 10692623
TI - Do nerve growth factor-related mechanisms contribute to loss of cutaneous
nociception in leprosy?
AB - While sensory loss in leprosy skin is the consequence of invasion by M. leprae of
Schwann cells related to unmyelinated fibres, early loss of cutaneous pain
sensation, even in the presence of nerve fibres and inflammation, is a hallmark
of leprosy, and requires explanation. In normal skin, nerve growth factor (NGF)
is produced by basal keratinocytes, and acts via its high affinity receptor (trk
A) on nociceptor nerve fibres to increase their sensitivity, particularly in
inflammation. We have therefore studied NGF- and trk A-like immunoreactivity in
affected skin and mirror-site clinically-unaffected skin from patients with
leprosy, and compared these with non-leprosy, control skin, following
quantitative sensory testing at each site. Sensory tests were within normal
limits in clinically-unaffected leprosy skin, but markedly abnormal in affected
skin. Sub-epidermal PGP 9.5- and trk A- positive nerve fibres were reduced only
in affected leprosy skin, with fewer fibres contacting keratinocytes. However,
NGF-immunoreactivity in basal keratinocytes, and intra-epidermal PGP 9.5-positive
nerve fibres, were reduced in both sites compared to non-leprosy controls, as
were nerve fibres positive for the sensory neurone specific sodium channel
SNS/PN3, which is regulated by NGF, and may mediate inflammation-induced
hypersensitivity. Keratinocyte trk A expression (which mediates an autocrine role
for NGF) was increased in clinically affected and unaffected skin, suggesting a
compensatory mechanism secondary to reduced NGF secretion at both sites. We
conclude that decreased NGF- and SNS/PN3-immunoreactivity, and loss of intra
epidermal innervation, may be found without sensory loss on quantitative testing
in clinically-unaffected skin in leprosy; this appears to be a sub-clinical
change, and may explain the lack of cutaneous pain with inflammation. Sensory
loss occurred with reduced sub-epidermal nerve fibres in affected skin, but these
still showed trk A-staining, suggesting NGF treatment may restore pain sensation.
PMID- 10692625
TI - Intensity dependence of auditory evoked cortical potentials in migraine families.
AB - Intensity dependence of auditory evoked cortical potentials is abnormal in
migraine. This study investigated intensity dependence in migraine and healthy
families using group comparisons and analysis of individual differences.
Migraineurs were characterized by a steeper amplitude/stimulus function slope and
more pronounced difference between the amplitudes of N1-P2 on the more and the
less intensive tones than healthy age matched subjects. Apart from migraine, the
age of the participants was an important predictive variable of intensity
dependence. Analysis of individual differences revealed low sensitivity and
moderate specificity of intensity dependence for migraine. Familial prevalence of
intensity dependence among first-degree relatives in migraine families was equal
to that in healthy families. These findings support the assumption that high
intensity dependence reflects a functional CNS trait which is more pronounced and
prevalent in migraine, but may also be found in healthy individuals and in other
neuropsychiatric disorders. Increased intensity dependence is only one of several
factors contributing to the risk for this form of headache.
PMID- 10692626
TI - Delta opioid receptor mediated actions in the rostral ventromedial medulla on
tail flick latency and nociceptive modulatory neurons.
AB - The rostral ventromedial medulla (RVM) is critical for the modulation of dorsal
horn nociceptive transmission. Three classes of RVM neurons (ON, OFF, and
NEUTRAL) have been described that have distinct responses to noxious stimuli and
mu opioid receptor (MOR) agonists. The present study in barbiturate anesthetized
rats investigated the effects of the delta 2 opioid receptor (DOR2) agonist, [D
Ala2]deltorphin II (DELT), microinfused into the RVM on the tail flick reflex and
activity of RVM neurons. Tail flick latencies increased dose-dependently after
administration of DELT (0.6 nmol and 1.2 nmol). Furthermore, DELT inhibited the
tail flick related increase in ON cell activity and shortened the tail flick
related pause in OFF cell activity. The activity of NEUTRAL cells was not
affected. The antinociceptive effects and corresponding changes in ON and OFF
cell activity produced by DELT were antagonized by the DOR2 antagonist, naltriben
methanesulfonate, administered at the same site. These DOR2 mediated effects on
noxious stimulation-evoked changes in RVM neuronal activity are similar to those
reported for MOR agonists and suggest that both DOR2 and MOR produce analgesia
through activation of OFF cells.
PMID- 10692627
TI - Dorsal column-thalamic pathway is involved in thalamic hyperexcitability
following peripheral nerve injury: a lesion study in rats with experimental
mononeuropathy.
AB - A total of 68 neurons were recorded from the ventro-postero-lateral nucleus of
thalamus (VPL) in rats with a unilateral chronic constriction injury (CCI) of the
sciatic nerve (n=20), sham operation (n=24) and naive rats (n=24), and effects of
the lesion of dorsal column (DC) pathway [DC lesion or DC+gracile nucleus
lesions] on VPL nucleus neuronal activities were studied. In the VPL nucleus
contralateral to the CCI (receiving input from the injured nerve), response
latencies of low threshold mechanoreceptive (LTM) and wide dynamic range (WDR)
neurons to electrical stimulation of the sciatic nerve were significantly longer
than that in the contralateral VPL nucleus receiving input from the sham-operated
side (P<0.05). In contrast, response latencies of LTM and WDR neurons to DC
stimulation were not different between the sham operated and CCI sides (0.05).
Background activity of WDR neurons was significantly higher in the VPL nucleus
contralateral to the CCI side when compared to neurons in the VPL nucleus
contralateral to the sham operated side and in naive animals. Responses of LTM
and WDR neurons to innocuous mechanical stimulation of the receptive fields were
significantly decreased after DC and DC+gracile nucleus lesions in all animals.
However, the responses of WDR neurons to noxious stimuli were selectively reduced
only in rats with CCI by DC and DC+gracile nucleus lesions (P<0.05). The decrease
in noxious stimulus-evoked responses of WDR neurons in the VPL nucleus
contralateral to the CCI side after DC and DC+gracile nucleus lesions was greater
than that in the VPL nucleus contralateral to the sham operated side and naive
animals. These results indicated that DC and DC+gracile nucleus lesions produced
selective and stronger effect on noxious responses of VPL nucleus WDR neurons
receiving input from the site of nerve injury. The findings suggest that the
gracile nucleus-thalamic pathway conveys, or modulates, nociceptive information
to the VPL nucleus following peripheral nerve injury, resulting in an increase in
VPL nucleus response to noxious stimuli that contributes to the development of
mechanical hyperalgesia.
PMID- 10692628
TI - Prolonged ovarian sex steroid treatment of male rats produces antinociception:
identification of sex-based divergent analgesic mechanisms.
AB - Simulation of the pregnancy blood concentration profile of 17beta-estradiol
(E(2)) and progesterone (P) in nonpregnant ovariectomized rats has been shown to
result in a significant elevation of nociceptive response thresholds. The present
report demonstrates that spinal opioid antinociceptive responsiveness to these
ovarian steroids is not sex-specific. Treatment of orchidectomized sexually
mature males with an analogous regimen of E(2) and P also elicits an
antinociception, the robustness and temporal profile of which is comparable with
that previously observed in females. Neither E(2) nor P, alone, is sufficient to
produce antinociception in male rats, as was previously demonstrated in females.
Neurobiological substrates and antinociceptive mechanisms underlying ovarian sex
steroid antinociception do, however, exhibit sex specificity. In males, the
analgesia resulting from ovarian steroid treatment derives from the independent
contributions of spinal kappa and mu, not delta, opioid receptor pathways that
are additive, not synergistic. Spinal alpha(2)-noradrenergic receptor activity
and its attendant analgesic synergy with spinal opioid systems do not contribute
to ovarian sex steroid analgesia in males. This is in contrast to the previous
demonstrations that ovarian sex steroid-induced antinociception in females
results from antinociceptive synergy between activated spinal kappa/delta opioid
as well as alpha(2)-noradrenergic receptor systems. The current data reveal that
ovarian steroid-activated multiplicative spinal antinociceptive pathways that had
been demonstrated in female rats are not manifest in their male counterparts.
PMID- 10692629
TI - Debilitating chronic pain syndromes after presumed intraneural injections.
AB - This report presents seven patients with severe disability established at the
time of a peripheral nerve block. In most of the cases, the injection was
administered as a routine procedure by an experienced anesthesiologist. The
patient histories suggest that the condition, which can be resistant to all
treatment, in most cases could have been avoided if careful attention had been
given to the occurrence of pain during the nerve block. It is likely that the
risk of devastating iatrogenic disability can be minimized if a few basic
principles are respected during the administration of peripheral nerve blocks.
PMID- 10692630
TI - Ziconotide for the treatment of severe spasticity after spinal cord injury.
AB - Spasticity is a major clinical manifestation of spinal cord injury and upper
motor neuron syndrome.
PMID- 10692631
TI - Adverse effects associated with the intrathecal administration of ziconotide.
AB - The omega-conopeptide, ziconotide, is an N-type calcium-channel blocker that has
been shown to produce antinociception in animals using formalin and hot-plate
tests. Initial reports of intrathecal administration of ziconotide in cancer and
AIDS patients whose pain was unrelieved with opioids demonstrated analgesic
efficacy. Although adverse effects were reported, these appeared to be easily
managed through dose reduction or symptomatic treatment. This clinical report
describes the experiences of three patients with serious adverse effects
associated with intrathecal ziconotide.
PMID- 10692632
TI - Electroconvulsive therapy for phantom limb pain.
AB - Phantom limb pain is common in amputees. Although several treatments are
available, a significant number of patients are refractory. Electroconvulsive
therapy (ECT), which is usually given to patients with psychiatric disorders such
as major depression, has shown efficacy in patients with a variety of pain
syndromes occurring along with depression. Two patients are described herein with
severe phantom limb pain refractory to multiple therapies, without concurrent
psychiatric disorder, who received ECT. Both patients enjoyed substantial pain
relief. In one case, phantom pain was still in remission 3.5 years after ECT. It
is concluded that phantom limb patients who are refractory to multiple therapies
may respond to ECT.
PMID- 10692633
TI - Complete Freund's adjuvant-induced hyperalgesia: a human perception.
AB - Much of our current understanding about chronic pain and the mechanisms of
nociception has been derived from animal models (Bennett GJ. Animal models of
neuropathic pain. In: Gebhart, GF, Hammond DL, Jensen TS, editors. Progress in
pain research and management, vol. 2, Proceedings of the 7th World Congress of
Pain. Seattle, WA: IASP Press, 1994. pp. 495-510; Dubner R, Methods of assessing
pain in animals. In: Wall PD, Melzack R, editors. Textbook of pain, vol. 3.
Edinburgh: Churchill Livingstone, 1994. pp. 293-302). It has been argued in some
cases that animals do not perceive 'pain' as humans do, and thus extrapolation of
the results of studies in animals is invalid. Clearly, the animal models used in
the laboratory do not approach the complexity of chronic pain encountered in the
clinical setting. Human pain perception is more complex since it encompasses
lesion variability, as well as psychosocial, cultural, developmental, and
environmental variables. Where parallels exist, it is possible to gain insight
into certain aspects of human pain syndromes that are likely to lead to improved
therapeutic opportunities for individual patients. One such model that is
frequently used in animals to study pain associated with inflammation is the
subcutaneous injection of complete Freund's adjuvant (CFA). For ethical reasons,
however, little information is available from humans concerning pain associated
with this form of inflammation. Due to an inadvertent subcutaneous injection of
CFA into the terminal phalanx of this investigator, a study with an N of 1, was
conducted to compare the subjective effects of CFA-induced inflammation with
objective measurements.
PMID- 10692634
TI - Virtual reality as an adjunctive pain control during burn wound care in
adolescent patients.
AB - For daily burn wound care procedures, opioid analgesics alone are often
inadequate. Since most burn patients experience severe to excruciating pain
during wound care, analgesics that can be used in addition to opioids are needed.
This case report provides the first evidence that entering an immersive virtual
environment can serve as a powerful adjunctive, nonpharmacologic analgesic. Two
patients received virtual reality (VR) to distract them from high levels of pain
during wound care. The first was a 16-year-old male with a deep flash burn on his
right leg requiring surgery and staple placement. On two occasions, the patient
spent some of his wound care in VR, and some playing a video game. On a 100 mm
scale, he provided sensory and affective pain ratings, anxiety and subjective
estimates of time spent thinking about his pain during the procedure. For the
first session of wound care, these scores decreased 80 mm, 80 mm, 58 mm, and 93
mm, respectively, during VR treatment compared with the video game control
condition. For the second session involving staple removal, scores also
decreased. The second patient was a 17-year-old male with 33.5% total body
surface area deep flash burns on his face, neck, back, arms, hands and legs. He
had difficulty tolerating wound care pain with traditional opioids alone and
showed dramatic drops in pain ratings during VR compared to the video game (e.g.
a 47 mm drop in pain intensity during wound care). We contend that VR is a
uniquely attention-capturing medium capable of maximizing the amount of attention
drawn away from the 'real world', allowing patients to tolerate painful
procedures. These preliminary results suggest that immersive VR merits more
attention as a potentially viable form of treatment for acute pain.
PMID- 10692635
TI - Potassium transport in fungi and plants.
PMID- 10692636
TI - Regulation of plasma membrane H(+)-ATPase in fungi and plants.
AB - The plasma membrane H+-ATPase from fungi and plants is a proton pump which plays
a key role in the physiology of these organisms controlling essential functions
such as nutrient uptake and intracellular pH regulation. In fungal and plant
cells the activity of the proton pump is regulated by a large number of
environmental factors at both transcriptional and post-translational levels.
During the last years the powerful tools of molecular biology have been
successfully used in fungi and plants allowing the cloning of a wide diversity of
H+-ATPase genes and rapid progress on the molecular basis of reaction mechanism
and regulation of the proton pump. This review focuses on recent results on
regulation of plasma membrane H+-ATPase obtained by molecular approaches.
PMID- 10692637
TI - Topology and transport of membrane lipids in bacteria.
AB - The last two decades have witnessed a break-through in identifying and
understanding the functions of both the proteins and lipids of bacterial
membranes. This development was parallelled by increasing insights into the
biogenesis, topology, transport and sorting of membrane proteins. However,
progress in research on the membrane distribution and transport of lipids in
bacteria has been slow in that period. The development of novel biochemical in
vitro approaches and recent genetic studies have increased our understanding of
these subjects. The aim of this review is to present an overview of the current
knowledge of the distribution and transport of lipids in both Gram-positive and
Gram-negative bacteria. Special attention is paid to recently obtained results,
which are expected to inspire further research to finally unravel these poorly
understood phenomena.
PMID- 10692638
TI - Recent progress in sustained/controlled oral delivery of captopril: an overview.
AB - The development of oral sustained or controlled release dosage form of captopril
has been an interested topic of research for a long period of time. Difficulties
encountered with such topic based on the fact that the drug is freely water
soluble and for obvious reasons, such drug is difficult to be delivered orally in
a sustained or controlled release manner and, on another hand, the drug is
unstable in the alkaline pH of the intestine, which enabled the scientists to
localize the developed formulations at the targeted areas of the GIT. Due to its
effectiveness and intensive use as a drug of choice in the treatment of
hypertension and congestive heart failure, numerous sustained and controlled
release formulations of captopril have been made and reported. Despite of these
numerous attempts and works, very few have been successful and some of these
formulations have been patented. The clinical supportive data regarding the
efficacies of these developed formulations are not always available and,
furthermore, their claims rely only on in vitro data.
PMID- 10692639
TI - Studies of polymorphism in three compounds by single crystal X-ray diffraction.
AB - The role of single crystal diffraction in the quantitative determination of
polymorphism is demonstrated by the examination of three compounds. Two
polymorphs were found for each of the compounds bis(2-nitrophenyl) trisulphide
(1), 2-amino-5-nitrobenzophenone (2) and bis(2-nitrophenyl) sulphide (3). Only in
one polymorph of (1) does molecular symmetry correspond with crystallographic
symmetry. In (2) the polymorphs arise in the same crystal class and in the same
crystallographic space group whereas in (3) the two polymorphs exist in different
crystal classes and hence in different space groups. Crystallographic space group
transformation is also discussed.
PMID- 10692640
TI - TR146 cells grown on filters as a model of human buccal epithelium: IV.
Permeability of water, mannitol, testosterone and beta-adrenoceptor antagonists.
Comparison to human, monkey and porcine buccal mucosa.
AB - The objective of the present study was to evaluate the TR146 cell culture model
as an in vitro model of human buccal epithelium. For this purpose, the
permeability of water, mannitol and testosterone across the TR146 cell culture
model was compared to the permeability across human, monkey and porcine buccal
mucosa. Further, the permeability rates of ten beta-adrenoceptor antagonists
(acebutolol, alprenolol, atenolol, labetalol, metoprolol, oxprenolol, pindolol,
propranolol, timolol and tertatolol) across the TR146 cell culture model and
porcine buccal mucosa were related to their lipophilicity (logD(oct; 7.4)) and
capacity factor (k') and to their polar water accessible surface area (PWASA).
For water, mannitol, testosterone and some of the beta-adrenoceptor antagonists,
the permeability enhancement across the TR146 cell culture model in the presence
of sodium glycocholate (GC) was determined. The mannitol and testosterone
permeability across the TR146 cell culture model could be related to the
permeability across porcine and human buccal mucosa. The permeability of the beta
adrenoceptor antagonists across the TR146 cell culture model varied between 2.2 x
10(-6) cm/s (atenolol) and 165 x 10(-6) cm/s (metoprolol). For propranolol the
cellular permeability value (P(c)) was lower than expected, probably due to
accumulation in the TR146 cell layers. Limited correlation of permeability with
k' was observed both for the TR146 cell culture model and the porcine buccal
mucosa, although the porcine permeability values were approximately 100 times
less than the values determined with the TR146 cell culture model. The
permeability values were also found to decrease with increasing PWASA. The PWASA
value seemed to be more predictable for permeability than k'. The presence of
12.5 mM GC increased the permeability only for the hydrophilic atenolol, which
may help explain the mechanism for GC-induced enhancement. The present results
indicate that the TR146 cell culture model can be used as an in vitro model for
permeability studies and mechanistic studies of human buccal drug delivery of
drugs with different lipophilicity.
PMID- 10692641
TI - Evaluation of poly(2-hydroxyethyl methacrylate) gels as drug delivery systems at
different pH values.
AB - Studies of dynamic and equilibrium swelling, structural characterisation and
solute transport in swollen poly(2-hydroxyethyl methacrylate) gels (pHEMA) cross
linked with tripropyleneglycol diacrylate (TPGDA) were done for a wide range of
TPGDA concentrations. The influence of the pH on these pHEMA properties was
evaluated. In swelling studies it was found that in changing the pH from 6.5 to
12.0, a large increase in swelling occurred, from approximately 48 to 55%, for
the lowest concentration of TPGDA (1 mol%), and from 40 to 80% for the highest
concentration (10 mol%). Fourier transform infrared (FTIR) and differential
scanning calorimetry (DSC) measurements were made after the equilibrium swelling
of the gels at different pH values, to explain these results. The advantage of
using these gels as controlled drug delivery systems is illustrated using
salicylic acid (SA) as a model drug. The loading and the release of the SA were
made at different pH values and the results obtained showed that it is possible
to modulate the hydrogel performance by controlling an external factor, the pH at
which the drug loading and release were performed.
PMID- 10692642
TI - Parameters affecting the efficacy of a sustained release polymeric implant of
leuprolide.
AB - The objective of this study was to evaluate the formulation parameters critical
to the efficacy of an injectable polymeric implant of leuprolide acetate, formed
in situ, in suppressing and maintaining serum testosterone levels of animals in
the range 0.5 ng/ml for over 90 days. The formulation evaluated contained 45%
(w/w) 75/25 poly (DL-lactide-co-glycolide) polymer having an intrinsic viscosity
of 0.20 dl/g, dissolved in 55% (w/w) N-methyl-2-pyrrolidone with 3% (w/w)
leuprolide acetate added either as a homogeneous solution or a two-part
suspension (A/B) system, in which the drug was dispersed within the polymer
solution immediately prior to use. The formulation parameters evaluated in this
study included polymer molecular weight, polymer concentration, and drug loading.
Both rat and dog models were used to evaluate efficacy. Serum testosterone was
assayed by radioimmunoassay to determine efficacy, and retrieved implants from
the rats at the termination of the study were analyzed by HPLC for residual drug
content to determine the extent of drug release. With the candidate formulation,
testosterone levels in dogs diminished to the targeted levels of 0. 5 ng/ml by
day 14 and remained suppressed up to day 91, reproducing the results seen in
rats. Variations in polymer concentration (40-50%), and drug load (3-6% (w/w))
did not have a significant effect on the apparent level and duration of efficacy.
However, employing lower molecular weight polymer decreased the duration of
efficacy of the formulation.
PMID- 10692643
TI - Intestinal first-pass effect of bumetanide in rats.
AB - The intestinal first-pass effect of bumetanide was investigated after intravenous
and intraportal infusion, and intragastric and intraduodenal instillation of the
drug to rats. The AUC(0-->8 h) values of bumetanide after intragastric and
intraduodenal instillation of the drug, 10 and 20 mg/kg, were significantly
smaller than AUC values after intraportal administration, suggesting that the
gastrointestinal first-pass effect of bumetanide was considerable in rats.
However, the AUC(0-->8 h) values of bumetanide between intragastric and
intraduodenal instillation were comparable, suggesting that the gastric first
pass effect of bumetanide was almost negligible in rats. The AUC(0-->8 h) values
of bumetanide after intraduodenal instillation were significantly smaller than
AUC values after intraportal infusion at 10 (89.8 vs 569 microg min per ml) and
20 (304 vs 1230 microg min per ml) mg/kg, indicating that the first-pass organ(s)
of bumetanide was intestine. The F values were 15.8 and 24.7% after intraduodenal
instillation of bumetanide, 10 and 20 mg/kg, respectively. Approximately 76.1 and
76.5% of intraduodenally instilled bumetanide disappeared (as a result of
absorption and first-pass effect) after 10 and 20 mg/kg, respectively. Therefore,
it could be concluded that approximately 60. 3 and 51.8% of the oral dose of
bumetanide disappeared by intestinal first-pass effect at 10 and 20 mg/kg,
respectively.
PMID- 10692644
TI - Lecithin vesicular carriers for transdermal delivery of cyclosporin A.
AB - Two kinds of vesicles with and without the presence of sodium cholate (flexible
vesicles and conventional vesicles) were prepared, using cyclosporin A as model
drug. When applied onto the excised abdominal skin of mice non-occlusively, the
enhancing effects of vesicles on the penetration of cyclosporin A were assessed
by an in vitro permeation technique. The effect of sodium cholate micelles was
also studied. In vivo study was carried out by topical application of vesicles
onto the mice skin and drug serum concentration was detected. Results showed that
after 8 h of administration, flexible vesicles transported 1.16 microg of
cyclosporin A through per cm(2) mice skin and amounted to 1.88 microg 24 h later.
The residual amount in the skin was 1.78+/-0.51 microg/cm(2). However, flexible
vesicles failed to transport measurable amount of drug through pre-hydrated skin
while deposited 2.39+/-0.26 microg/cm(2) into the skin. Conventional vesicles
failed to transfer cyclosporin A into the receiver while accumulated 0. 72+/-0.19
microg/cm(2) of drug in the skin. Furthermore, 1 and 40% sodium cholate micelles
precluded the transport of cyclosporin A. In vivo studies indicated that with the
application of flexible vesicles, serum drug concentration of 53.43+/-9.24 ng/ml
was detected 2 h later. After the stratum corneum of mouse skin has been
destroyed by shaving, flexible vesicles transferred large amount of drug into
blood, up to 187.32+/-53.21 ng/ml after 1 h of application. Conventional vesicles
failed to deliver measurable amount of drug into the blood under normal skin
condition. In conclusion, flexible vesicle is better than conventional vesicle as
the carrier for transdermal delivery of cyclosporin A. Penetration and fusion
have been suggested to be two major functional mechanisms. Hydration is
detrimental to the enhancement effect. Stratum corneum constitutes main barrier
to the transport of lipophilic cyclosporin A.
PMID- 10692645
TI - Cellular transport processes of aminoguanidine, a nitric oxide synthase
inhibitor, in the opossum kidney cell culture line.
AB - Aminoguanidine has potential pharmacologic utility for diabetes and nitric oxide
mediated inflammation. Because aminoguanidine is positively charged at
physiologic pH (pK(a) approximately 10), it is unlikely that simple diffusion is
a predominant mechanism for cellular penetration. This study sought to determine
the transport processes by which aminoguanidine, a cationic compound, traverses
across cellular membranes. In cultured opossum kidney (OK) cell monolayers,
aminoguanidine transport involved both saturable and non-saturable diffusion
processes. At passage numbers below 67, the observed V(max) and K(m) for
saturable influx were significantly lower than that observed at passages greater
than 79 (V(max): low passage, 21.2+/-7.8 pmol/(min*mg protein), n=3; versus high
passage, 129.7+/-24.3 pmol/(min*mg protein), n=3, P<0.05; K(m): low passage,
23.7+/-10.8 microM, n=3; versus high passage, 101.7+/-5.6 microM, n=3, P<0.05;
mean+/-S.E.M.). Nonsaturable processes were not statistically different (k(ns):
low passage, 1.6+/-0.1 pmol/(min*mg protein*microM), n=3; high passage, 1.1+/-0.2
pmol/(min*mg protein*microM) n=3). Saturable influx was temperature dependent,
and independent of ATP energy, sodium gradients or changes in membrane potential.
Other organic cations competitively inhibited and trans-stimulated saturable
influx. Aminoguanidine influx was increased in the presence of an outwardly
directed proton gradient and was inhibited in the presence of an inwardly
directed proton gradient. Correspondingly, aminoguanidine efflux was trans79)
express a saturable, bi-directional carrier-mediated process to transport
aminoguanidine across cellular membranes.
PMID- 10692646
TI - Pharmacokinetic changes of cyclosporine after intravenous and oral administration
to rats with uranyl nitrate-induced acute renal failure.
AB - The effects of renal failure on the pharmacokinetics of cyclosporine were
investigated after intravenous, 30 mg/kg, and oral, 100 mg/kg, administration of
the drug using a rat model of uranyl nitrate-induced acute renal failure (U-ARF).
After intravenous administration to rats with U-ARF, the volume of distribution
at steady state (1.97 vs. 2.56 l/kg) was significantly smaller, and the area
under the blood concentration-time curve (348 vs. 296 microg h/ml) tended to be
greater and total body clearance (0.0851 vs. 0. 102 l/h per kg) tended to be
slower than those in control rats. After oral administration, the pharmacokinetic
parameters were not significantly different between the control rats and rats
with U-ARF, suggesting that U-ARF did not considerably affect the
pharmacokinetics of cyclosporine after oral administration.
PMID- 10692647
TI - Influence of the acid type on the physical and drug liberation properties of
chitosan-gelatin sponges.
AB - The influence of acid type used to dissolve chitosan on the resulting sponge
physical properties, and their consequent effect on the drug liberation were
investigated. Chitosan was dissolved in different acid solutions and chitosan
gelatin sponges were produced by frothing up the polymer solution and then freeze
drying the foam. Prednisolone was used as a model drug. Using tartaric or citric
acid resulted in instable, soft, elastic and disintegrating sponges with fast
drug release. Elastic but harder sponges from stable foams were obtained when
hydrochloric or lactic acid were used. The use of acetic or formic acid enabled
the production of stable foams, soft and elastic sponges and a slow drug release.
The rate of drug release was decreased by crosslinking the polymers with
glutaraldehyde, but only if acetic, formic or acetic acid were used. Therefore,
it is possible to manipulate the mechanical properties and the drug liberation
rate by using different acids to dissolve chitosan.
PMID- 10692648
TI - Synthesis and characterisation of mucoadhesive thiolated polymers.
AB - This study examined various factors influencing the mucoadhesive properties of
thiolated polymers (thiomers), which are capable of forming covalent bonds with
thiol sub-structures of the mucus glycoprotein. Mediated by a carbodiimide, L
cysteine was therefore covalently bound to polycarbophil (PCP) and to
carboxymethylcellulose (CMC). The resulting polymer conjugates displayed 12.3 and
22.3 micromol thiol groups per gram, respectively. Whereas the swelling behaviour
of tablets based on CMC was not markedly influenced by the immobilisation of
cysteine, it was improved significantly (P<0.05) in case of PCP. Tensile studies
carried out with the unmodified and thiolated polymers of pH 3, 5 and 7,
respectively, revealed that only if the polymer displays a pH-value of 5, the
total work of adhesion can be improved significantly due to the covalent
attachment of thiol groups. These results were in good agreement with a new
mucoadhesion test system described here taking also the cohesiveness of the
delivery system into account. The results represent helpful basic information in
order to improve the mucoadhesive properties of thiolated polymers.
PMID- 10692649
TI - A comparative in vitro study of percutaneous penetration of beta-blockers in
human skin.
AB - In vitro diffusion experiments with propranolol, oxprenolol, metoprolol and
atenolol were carried out using excised human abdominal skin. The main permeation
parameters (permeability coefficient, flow and lag time) were calculated and
compared as measurement of intrinsic permeability across human skin. A long lag
time and a low steady-state flow were found for all drugs assayed. Skin
permeability predicted at steady state did not reach therapeutic concentrations,
which indicated the need for appropriate chemical penetration enhancers or
vehicles to overcome limiting factors. The results, including those of celiprolol
and bisoprolol reported previously, correlated with physicochemical properties,
especially with lipophilicity, one of the main factors in drug permeability
prediction through human skin.
PMID- 10692650
TI - In vitro biocompatibility studies with the experimental anticancer agent
BIBX1382BS.
AB - The novel anticancer agent BIBX1382BS is a representative of the human epidermal
growth factor receptor (EGFR) tyrosine kinase inhibitors. BIBX1382BS, for
parenteral use, is formulated pharmaceutically as a lyophilized product
containing 100 mg BIBX1382BS per dosage unit. This in vitro study was performed
to establish the optimal intravenous administration conditions (infusion
concentration and infusion rate) for the forthcoming clinical absolute oral
bioavailability study of BIBX1382BS. BIBX1382BS infusion solutions have a low pH
in order to keep the substance in solution. We therefore decided to investigate
the hemolytic and precipitation potential of the drug in vitro. Also, the ratio
of formulation (F) solution volume and a blood simulans (B) volume necessary to
reach the physiological pH, expressed as the FB-ratio, was determined in vitro.
On the basis of the results obtained, it is advised to administer BIBX1382BS
infusion at a concentration of 1 mg/ml and a maximum infusion rate of 10 ml/min.
This article describes the in vitro biocompatibility screening program.
PMID- 10692651
TI - The role of the cardiovascular specialist in the prevention of cardiovascular
diseases - executive summary.
PMID- 10692652
TI - The global burden of cardiovascular diseases.
PMID- 10692653
TI - The burden of cardiovascular diseases in Canada.
PMID- 10692654
TI - Prevention and control of risk factors among children and youth.
PMID- 10692655
TI - Women and cardiovascular diseases.
PMID- 10692656
TI - Cardiovascular disease prevention in the elderly.
PMID- 10692657
TI - Cardiovascular diseases and aboriginal peoples.
PMID- 10692658
TI - Cardiovascular diseases in ethnic groups.
PMID- 10692659
TI - Lipids and cardiovascular diseases.
PMID- 10692660
TI - The 1999 Canadian recommendations for the management of hypertension. On behalf
of the Task Force for the Development of the 1999 Canadian Recommendations for
the Management of Hypertension.
PMID- 10692661
TI - Obesity and cardiovascular diseases.
PMID- 10692662
TI - Emerging risk factors associated with cardiovascular diseases.
PMID- 10692663
TI - Smoking.
PMID- 10692664
TI - Diet and the prevention of cardiovascular diseases.
PMID- 10692665
TI - Physical inactivity.
PMID- 10692666
TI - Psychosocial risks and cardiovascular diseases.
PMID- 10692667
TI - Socioeconomic factors and social support.
PMID- 10692668
TI - Risk factors for stroke.
PMID- 10692669
TI - Peripheral arterial disease.
PMID- 10692670
TI - Cardiac rehabilitation programs.
PMID- 10692671
TI - The cost effectiveness of preventing cardiovascular diseases.
PMID- 10692672
TI - Partnerships in cardiovascular disease prevention.
PMID- 10692673
TI - Apoptosis, bcl-2 expression and p53 accumulation in myelodysplastic syndrome,
myelodysplastic-syndrome-derived acute myelogenous leukemia and de novo acute
myelogenous leukemia.
AB - Apoptosis and its dysregulation have been implicated in dysplastic and
ineffective hematopoiesis and the neoplastic transformation of bone marrow in
myelodysplastic syndrome (MDS). To explore the role of apoptosis in hematological
disorders, we examined the frequency of apoptotic cells by the in situ end
labeling method in bone marrow specimens from 37 patients with MDS [refractory
anemia (RA) 10 cases, RA with excess of blasts (RAEB) 27 cases including 12 cases
with leukemic transformation], 12 patients with MDS-derived acute myelogenous
leukemia (AML) and 13 patients with de novo AML. In addition, we investigated the
relationship of apoptosis to the immunohistochemical expression of bcl-2 and p53
in these cases, and the association of apoptosis, bcl-2, and p53 with the
leukemic evolution of MDS by examining sequential bone marrow samples of the same
patient from the time of initial diagnosis to the time of overt leukemia. The
percentage frequency of apoptotic cells was significantly greater in MDS (RA:
9.46 +/- 2.99%, m +/- SD; RAEB: 5. 60 +/- 3.09) as compared with those in MDS
derived AML (0.62 +/- 0. 37), de novo AML (0.28 +/- 0.11) and controls (1.00 +/-
0.59). On the other hand, the cases of RAEB with leukemic transformation
exhibited a lower frequency of apoptotic cells and a higher frequency of bcl-2-
and p53-positive cells than those without transformation. When the RAEB cases
transformed to AML, the frequency of apoptotic cells was significantly reduced
(2.96 +/- 1. 54 --> 0.62 +/- 0.37), while the frequencies of bcl-2-positive cells
and p53-positive cells were greater (10.88 +/- 3.66 --> 30.54 +/- 7. 14, and
20.21 +/- 6.21 --> 32.34 +/- 14.71, respectively). In contrast to MDS-derived
AML, over a half of de novo AML cases showed few p53-positive cells. These
findings corroborate the earlier notion that apoptosis may play a substantial
role in dysplastic and ineffective hematopoiesis in MDS. It is also suggested
that the suppression of apoptosis associated with enhanced bcl-2 expression and
p53 accumulation increases the probability of developing leukemia in MDS, and
that oncogenetic development might be different between MDS-derived AML and de
novo AML.
PMID- 10692674
TI - Function and X chromosome inactivation analysis of B lymphocytes in
myelodysplastic syndromes with immunological abnormalities.
AB - To investigate the pathogenesis of immunological abnormalities (IA) in
myelodysplastic syndrome (MDS), we examined B cells for their ability to produce
cytokine and their X chromosome inactivation pattern (XCIP). An IA was defined as
being positive for at least one autoimmune laboratory test (e.g. antinuclear
antibody, rheumatoid factor). Seventy-three MDS patients [65 with refractory
anemia (RA), 3 with RA with excess blasts (RAEB), and 5 with RAEB in
transformation] were examined; 47 had IA and 26 had no IA. To examine the
function of B cells in MDS, the production of interleukin (IL)-6 and IL-10 was
measured in cultures of purified B cells with or without stimulators. Both IL-6
and IL-10 production rates in patients with IA were significantly higher than in
patients without IA and normal controls. The skewing of XCIP of B cells was
analyzed by using the polymerase chain reaction, and the skewing rate of B cell
XCIP was quantitatively assayed by compared to control T lymphocytes. The skewing
rate of B cells was higher in patients with IA than in those without IA and
normal controls. Therefore, a small population of B cells in patients with IA
might be derived from MDS clones, and be associated with the induction of IA.
PMID- 10692675
TI - Plasma thrombopoietin concentrations in response to platelet transfusion therapy.
AB - Studies performed in rabbit and mouse models and in a limited number of human
subjects, show that transfused platelets bind thrombopoietin (TPO) and decrease
its concentration in the circulation. The aim of the present study was to further
examine this relationship. The material comprised 12 patients receiving a total
of 21 transfusions, as part of the routine clinical treatment. Blood samples were
collected from the patients immediately before and 30 min after completion of the
platelet transfusion, and the corrected platelet count increment (CCI) was
calculated. A commercially available ELISA kit was used to determine plasma TPO
concentrations. Statistically significant reductions in median TPO concentration
were observed in response to the platelet transfusions. Patients who were
refractory to platelet transfusions showed the slightest decrease in TPO
concentration. As for the linear regression between change in TPO level and CCI,
only borderline significance was observed. Thus, our findings support the concept
that platelets can remove TPO from the circulation.
PMID- 10692676
TI - The synergistic effect of thrombopoietin in erythropoiesis and myelopoiesis from
human bone marrow cells.
AB - We sought to determine whether recombinant human thrombopoietin (TPO) acts
synergistically with recombinant human erythropoietin (EPO) and/or recombinant
human interleukin-3 (IL-3) on erythroid burst formation and granulocyte
macrophage colony formation from human bone marrow (BM). BM cells were from 5
adults and 15 children who underwent bone marrow examination because of a
clinical suspicion of malignancy; their bone marrows as well as the complete
blood counts were normal and were cultured in a methylcellulose system. TPO has a
synergistic effect with EPO or EPO + IL-3 on erythropoiesis of human BM, as the
addition of TPO to EPO significantly gave rise to more erythroid bursts (p =
0.0001) and the addition of TPO to EPO + IL-3 might give rise to more erythroid
bursts (p = 0.05). TPO also has a synergistic effect with recombinant human
granulocyte colony-stimulating factor (G-CSF) on myelopoiesis of human BM, since
the addition of TPO to G-CSF gave rise to significantly more granulocyte
macrophage colonies (p = 0. 0001). Besides its well-known significant role in
megakaryopoiesis, TPO also has synergistic effects on erythropoiesis and
myelopoiesis.
PMID- 10692677
TI - GM-CSF in sickle cell anemia patients with elevated Hb F.
AB - We estimated plasma GM-CSF levels in a group of 28 steady-state sickle cell
anemia (SS) patients in Kuwait, using an ELISA technique. There were 24 age
matched Hb AA controls, 14 of whom were healthy while 10 were acutely ill at the
time of the study. Five SS patients were also studied during 6 episodes of
painful crisis. Among the SS patients, 82.1% were homozygous for the Saudi
Arabia/India (SAI) haplotype with Hb F ranging from 15 to 35% and total Hb from
8.5 to 11 g/dl. Three patients (siblings) were SAI/Benin compound heterozygotes
with Hb F of 9-23% and total Hb >10 g/dl. One patient each was homozygous for the
Benin or the Bantu haplotype; they had Hb F <2% and total Hb of 6.6 and 7.2 g/dl,
respectively. Four (14. 3%) steady-state SS patients had detectable plasma GM-CSF
ranging from 75 to 1,817.6 pg/ml. These included the 2 patients with Hb F <2. 0%
and 2 with the SAI/Benin compound heterozygotes with Hb F of 11 and 9%,
respectively. Four (66.7%) SS patients in crisis, 6 (42.9%) healthy controls and
6 (60%) acutely ill controls had detectable plasma GM-CSF. A clearcut association
of GM-CSF with Hb F level or degree of anemia in steady-state SS patients could
not be established. The appearance of GM-CSF in the plasma of patients in crisis
and also among control subjects raises the possibility that other factors are
involved in the production of this cytokine in the subjects studied.
PMID- 10692678
TI - Efficacy of further attempts to mobilize CD34+ peripheral stem cells with
alternative procedures after primary failure.
AB - 19 patients who failed the target collection of at least 2.5 x 10(6) CD34+
cells/kg underwent further mobilization procedures either with granulocyte-colony
stimulating factor (G-CSF) alone after failure to chemotherapy plus G-CSF (group
1), or with chemotherapy plus G-CSF (group 2), or with high-dose G-CSF (24
microg/kg) alone (group 3) after failure to respond to standard dose of G-CSF (10
microg/kg) alone. In all groups, an increase in median CD34+ cell yield could be
observed following alternative procedures (1.1- to 1.9 x 10(6) kg; p = 0.02). The
highest increase in CD34+ cell harvest was achieved in group 1 (0.85 to 2.2 x
10(6) kg), followed by group 2 (1. 2 to 1.7) and group 3 (1.0 to 1.4), but
without statistically significant difference between the mobilization
technologies. All patients with more than 1.0 x 10(6) CD34+ cells/kg in the first
apheresis procedure reached the overall target of 2.5 x 10(6) CD34+ cells/kg
after a second or subsequent mobilization procedure. In contrast, only 3 of 8
patients (37%) with less than 1.0 x 10(6) CD34+ cells in the first harvest could
reach the target of 2.5 x 10(6) CD34+ cells after further mobilization attempts.
PMID- 10692679
TI - Effect of ozone on red blood cell enzymes and intermediates.
AB - Ozone autohemotherapy has been considered a form of alternative medicine and has
not yet been subjected to the rigors of well-designed clinical trials. Despite
encouraging anecdotal reports regarding the use of ozone in various disorders,
there has been a concern that ozone per se may adversely affect red cell
membranes and metabolites. The purpose of this study was to ascertain the effect
of ozone administration at a concentration commonly used in autohemotherapy on a
panel of red cell enzymes and intermediates, as well as its effect on red cell
integrity. Since these parameters were unaffected by ozone, we suggest that
clinical trials for the use of ozone autohemotherapy should be encouraged.
PMID- 10692680
TI - Are haemochromatosis mutations related to the severity of liver disease in
hepatitis C virus infection?
AB - It has been proposed that iron overload may adversely affect liver disease
outcome. The recent identification of 2 mutations in the HFE gene related to
hereditary haemochromatosis (Cys282Tyr and His63Asp) provided an opportunity to
test whether they are associated with hepatic iron accumulation and the activity
and severity of liver disease in hepatitis C virus (HCV) infection. We
investigated the prevalence of HFE mutations in 135 male patients with chronic
HCV hepatitis, and correlated genotype distribution with different parameters of
iron status and the activity and severity of liver disease. Of these 135
patients, 6 (4.4%) carried Cys282Tyr and 32 (23.7%) carried His63Asp, frequencies
which were similar to those observed in healthy controls. Serum iron levels and
transferrin saturation (but not ferritin levels or liver iron content) were
significantly higher in carriers than in non-carriers of HFE mutations. No
difference was observed in serum ALT, AST and GGT levels between carriers and non
carriers. Finally, scores for necroinflammatory activity and fibrosis in the
liver were significantly higher in HFE carriers than in non-carriers. Patients
with chronic HCV infection carrying HFE mutations tend to present more evident
body iron accumulation and a higher degree of necroinflammatory activity and
fibrosis in the liver. HFE gene mutations might be an additional factor to be
considered among those implicated in the determination of a worse prognosis of
the liver disease in chronic HCV infection.
PMID- 10692681
TI - Graft failure of autologous peripheral blood stem cell transplantation due to
acute metabolic acidosis associated with total parenteral nutrition in a patient
with relapsed breast cancer.
AB - A 32-year-old female had been diagnosed as having relapsed breast cancer and
liver metastasis. She underwent high-dose chemotherapy followed by autologous
peripheral blood stem cell transplantation (PBSCT) with 5.8 x 10(6)/kg CD34+
cells. She was supported by total parenteral nutrition (TPN) without vitamins
throughout these therapies. Hematopoietic recovery was not observed by day 28
after PBSCT, necessitating a second PBSCT on day 29 using the back-up material of
4.4 x 10(6)/kg CD34+ cells. On the next day, she suddenly developed severe
metabolic acidosis, heart failure and deep coma. After immediate infusion of
thiamine, heart failure and coma rapidly improved. The neutrophil count reached
0.5 x 10(9)/l on day 9 and the platelet count 50 x 10(9)/l on day 15 after the
second PBSCT. This is a rare graft failure due to acute metabolic acidosis or
thiamine deficiency associated with TPN.
PMID- 10692682
TI - Thrombotic thrombocytopenic purpura during interferon alpha treatment for chronic
myelogenous leukemia.
AB - Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome have
recently been observed in patients undergoing interferon alpha (IFN-alpha)
therapy. However, the relationship between disease and therapy has not been
established, essentially because of concomitant treatment or previous bone marrow
transplantation. We present a case of TTP developing during IFN-alpha therapy for
chronic myelogenous leukemia. In this case, IFN-alpha seems to be the only
etiological agent.
PMID- 10692704
TI - The relationship of patient education and hypertension treatment compliance.
PMID- 10692706
TI - Status of nurse practitioner practice. Report 1.
PMID- 10692705
TI - Athena found or lost: the precepting experiences of mentored and non-mentored
nurse practitioner students.
PMID- 10692707
TI - Prescriptive authority: a dilemma facing advanced practice nurses.
PMID- 10692708
TI - Nutrition information on the Internet.
PMID- 10692709
TI - Respiratory syncytial virus: understanding the threat to communities.
PMID- 10692710
TI - Management of tension-type headache.
AB - Tension-type headache is now the term used to describe headaches that have
previously been grouped under various ill-defined headings such as 'tension
headache', 'stress headache' and 'muscle contraction headache'. Tension-type
headaches are characterized by pain that is mild or moderate in severity,
bilateral in distribution, pressing or tightening in quality, and unaccompanied
by major systemic disturbance or neurological signs. While many people have mild,
infrequent tension-type headaches which they do not regard as an illness, a
minority have chronic and often daily symptoms. Here we review the management of
tension-type headaches in adults.
PMID- 10692711
TI - Management of ectopic pregnancy.
AB - Each year, around 11,000 women in the UK (around 1% of all pregnancies) present
with an ectopic pregnancy, in which a fertilised ovum implants elsewhere than in
the uterine cavity, usually a Fallopian tube. Left untreated, tubal ectopic
pregnancy can lead to rupture of the Fallopian tube and life-threatening
haemorrhage, and never results in a live birth. Improvements in management have
led to a fall in the mortality rate from 2.9 per 1000 ectopic pregnancies in the
early 1970s to 0.4 per 1000 in 1994-1996. Here we review the current management
of tubal ectopic pregnancy.
PMID- 10692712
TI - Tazarotene--a topical retinoid for psoriasis.
AB - Retinoids have been given systemically for severe psoriasis for several years.
Tazarotene (Zorac-Allergan), the first retinoid to be marketed as a topical
preparation for psoriasis, was recently licensed for mild-to-moderate plaque
psoriasis involving up to 10% of the body surface area. Here we assess its place
in the management of psoriasis.
PMID- 10692713
TI - Withdrawing patients from antidepressants.
AB - Around 1 in 5 people experience an episode of major depressive illness at some
time in their lives, and many experience relapse or recurrence. To prevent early
relapse, most experts now recommend several months' treatment for patients with
acute episodes of depression. Patients considered at high risk for recurrence of
severe depression may need long-term maintenance treatment. Doctors have to
advise their patients whether and when it is prudent to stop treatment, and must
be alert to potential problems when antidepressants are withdrawn. The two main
problems are relapse or recurrence of depression, and effects arising from
withdrawal of the drugs themselves. We discuss the withdrawal of antidepressant
drug treatment in adults with unipolar depression.
PMID- 10692714
TI - Nicotine replacement to aid smoking cessation.
AB - Cigarette smoking remains the commonest cause of preventable mortality in the UK,
accounting for about 120,000 deaths each year among people aged 35 years or more.
In all, smoking-related disease costs a typical health authority around 15
million Pounds a year. It is notoriously difficult to stop smoking but success
rates are increased if cigarettes are replaced by nicotine given as a medicine.
When reviewing nicotine replacement in 1993, we recommended a "combined approach,
using nicotine patches plus advice and support". Since then, other forms of
nicotine replacement have become available. Here we discuss current evidence on
the efficacy and safety of different forms of nicotine replacement and consider
the place of such therapy.
PMID- 10692715
TI - Who decides on treatment: the patient versus the state.
AB - In March this year, we held our seventh annual symposium entitled: 'Who decides
on treatment: the patient versus the State'. Within the NHS, there are many
levels at which treatment decisions are made. At one extreme, decisions involve
individuals at the point of 'delivery' and so are taken during the consultation
and involving the patient and prescriber. At the other extreme, decisions are a
national matter and taken by government. The symposium explored the changing
environments of decision-making and the contribution of those involved. Here we
summarise the talks and incorporate ideas that arose in discussion.
PMID- 10692716
TI - Defining optimal dosing for sumatriptan tablets in the acute treatment of
migraine.
AB - Oral sumatriptan, which is a well tolerated, effective acute treatment for
migraine, and is selectively available in different countries in 100 mg, 50 mg,
and 25 mg tablets. The first large dose-ranging study compared the 100 mg dose to
higher doses (200 mg and 300 mg) and found it to be just as efficacious and
better tolerated. The first studies comparing the 100 mg dose to lower doses (25
mg and 50 mg) found them all to be similar in effectiveness and tolerability.
However, a larger definitive study found that the 100 mg and 50 mg doses offered
better efficacy than the 25 mg dose, whereas the 25 mg and 50 mg doses were
better tolerated than the 100 mg dose. Thus the 50 mg dose appears to offer the
best ratio of efficacy to tolerability. Many patients, though, prefer or require
the 100 mg dose and tolerate it well. Allowed to select dosing themselves,
patients tend to migrate to the 100 mg dose.
PMID- 10692718
TI - Patient preference for oral sumatriptan 25 mg, 50 mg, or 100 mg in the acute
treatment of migraine: a double-blind, randomized, crossover study. Sumatriptan
Tablets S2CM11 Study Group.
AB - BACKGROUND: Dosing recommendations for oral sumatriptan have ranged from 25 mg to
100 mg. Patient dose preferences are clinically relevant (perhaps moreso than
traditional efficacy endpoints) and deserve study. METHODS: A multinational
randomized double-blind crossover study was conducted over 18 weeks to assess
patient dose preference, efficacy, and tolerability for oral sumatriptan (25 mg,
50 mg, and 100 mg) in the acute treatment of migraine; 257 patients treated three
attacks, using a different dose for each. RESULTS: The 100 mg dose was preferred
by 35% of patients, 31% the 50 mg dose, and 25% the 25 mg dose. Efficacy and
speed of action were the two main reasons given for preferring the higher doses.
Compared with the 25 mg dose, the 100 mg and 50 mg doses were significantly more
likely to provide headache relief at 2, 3, and 4 h after dosing and complete
headache resolution at 3 and 4 h after dosing (P < 0.027). Recurrence rates were
similar for the three doses, ranging from 33% to 38%, though the median time to
recurrence increased with dose, from 8.5 to 11.8 h. The 25 mg, 50 mg, and 100 mg
doses were all well tolerated, with adverse event incidences of 19%, 21%, and
30%, respectively. CONCLUSIONS: Patients preferred the 50 mg and 100 mg doses of
oral sumatriptan to the 25 mg dose, and the higher doses were more effective
against migraine; however, the 25 mg and 50 mg doses were better tolerated than
the 100 mg dose. Though the 50 mg dose probably has the best effectiveness-to
tolerability ratio, some patients clearly prefer a higher dose.
PMID- 10692717
TI - A double-blind placebo-controlled study assessing the efficacy and tolerability
of 50 mg sumatriptan tablets in the acute treatment of migraine. Sumatriptan
Tablets S2CM07 Study Group.
AB - BACKGROUND: Oral sumatriptan 50 mg has been found to have good efficacy and
tolerability in the acute treatment of migraine but has been less well studied
than the 100 mg dose. METHODS: This was a double-blind, parallel-group study
(Glaxo Wellcome protocol number S2CM07) comparing the efficacy and safety of
sumatriptan 50 mg tablets with placebo in the acute treatment of migraine.
Patients treated three migraine attacks with study medication; a second, optional
dose was available for treating recurrent headache. Of the 560 patients
randomized, 485 treated at least one attack, 411 at least two attacks, and 362
three attacks. The primary efficacy measure was the proportion of patients who
had obtained complete or almost complete headache relief at 4 h after dosing.
RESULTS: For all attacks, a significantly greater proportion of patients
experienced headache relief at 4 h with sumatriptan 50 mg tablets than with
placebo (59% to 62% versus 32% to 42%; P = 0.005). The same was true at 3 h
across all attacks, and at 2 h for attacks 1 and 2 (49% versus 23% and 45% versus
29%, respectively). Although sumatriptan and placebo were associated with similar
incidences of recurrence, sumatriptan was associated with a longer time to
recurrence. The incidence of adverse events with sumatriptan was similar to that
with placebo, and there was no increase in adverse events associated with use of
a second dose to treat recurrence. CONCLUSIONS: Sumatriptan 50 mg tablets are
well tolerated and efficacious in relieving migraine headache.
PMID- 10692719
TI - Patient-selected dosing in a six-month open-label study evaluating oral
sumatriptan in the acute treatment of migraine. Sumatriptan Tablets S2CM10 Study
Group.
AB - BACKGROUND: Dosing recommendations for oral sumatriptan as acute treatment for
migraine have ranged from 25 mg to 100 mg. Patient dose preferences have not been
studied in a setting mimicking clinical practice. METHODS: In an open-label study
evaluating patient acceptance and the relative efficacy and safety of 25 mg, 50
mg, and 100 mg doses of oral sumatriptan over a period of six months, 338
patients treated three migraine attacks with 50 mg sumatriptan and then were
allowed to double or halve the dose. After treating another three attacks, they
were again allowed to adjust the dose by one level. RESULTS: After migraine
attack 3, 37% of patients chose to continue with the 50 mg dose, 50% increased
the dose to 100 mg, and 12% decreased it to 25 mg. After attack 6, 8%, 33%, and
58% of patients chose the 25 mg, 50 mg, and 100 mg doses, respectively; only 3%
of those taking the 100 mg dose chose to reduce it. Overall, the mean percentages
of attacks per patient in which headache relief had been obtained 4 h after
dosing were 71%, 71%, and 80% for the 25 mg, 50 mg, and 100 mg doses,
respectively. Patients who decreased the dose to 25 mg after attack 3 experienced
decreases both in adverse events and percentage of attacks with headache relief,
whereas in those who increased the dose to 100 mg, likelihood of headache relief
increased but the incidence of adverse events did not. CONCLUSIONS: More patients
chose the 50 mg or 100 mg dose than the 25 mg dose. All three doses had similar
efficacy and tolerability.
PMID- 10692720
TI - Evidence in myocardial infarction.
PMID- 10692721
TI - Chronic heart failure: evidence for ACE inhibitors.
PMID- 10692722
TI - ACE inhibitors: the evidence in hypertension.
PMID- 10692723
TI - Structural basis of LV dysfunction: collagen matrix remodelling and the renin
angiotensin-aldosterone system.
PMID- 10692724
TI - The role of transcription factors in the pathogenesis of type 2 diabetes.
PMID- 10692725
TI - State of current therapy and patient care in Europe.
PMID- 10692726
TI - Optimisation of insulin treatment to improve cardiovascular risk.
PMID- 10692727
TI - The importance of postprandial hyperglycaemia.
PMID- 10692728
TI - The role of insulin treatment in type 2 diabetes.
PMID- 10692729
TI - Research advances in the treatment of type 2 diabetes mellitus.
PMID- 10692730
TI - American journal owners 2, principled editors 0.
PMID- 10692731
TI - Microalbuminuria: should lowering albumin excretion be a therapeutic goal?
PMID- 10692732
TI - Leg cramps in the elderly: prevalence, drug and disease associations.
AB - To determine the prevalence of leg cramps in elderly outpatients and their
association any underlying diseases and concomitant drug intake, we conducted a
cross-sectional study using an in-depth questionnaire. A total of 365 patients
aged 65 years and over (mean 78.5 years) attending our outpatient clinic
participated in the study. The prevalence of leg cramps was 50%. Cramps were
commoner in females (56%) than in males (40%). Although reported to occur anytime
throughout the 24 hours, cramps were most prevalent at night (62%). In many
patients, leg cramps were a long-standing complaint: 20% had been suffering with
them for more than 10 years, whereas only 9% of patients reported them first
starting within the last six months. Only 73 (40%) sufferers had informed their
practitioner; of these, 39 (53%) received treatment, of whom 26 gained benefit.
Leg cramps were strongly associated with peripheral vascular disease (odds ratio
2.9, 95% CI 1.89-4.55, p < 0.00001), arthritis (odds ratio 2.26, 95% CI 1.48
3.45, p = 0.0001) and female gender (odds ratio 1.96, 95% CI 1.28-3.03, p =
0.002). Heart failure, hypertension, diabetes mellitus and stroke were not
significantly associated. Except for a causal association with analgesic use, no
positive association could be shown with any other class of drugs, including
diuretics.
PMID- 10692734
TI - Does the eradication of Helicobacter pylori cure duodenal ulcer disease in
communities with a high prevalence rate? Comparison with long-term acid
suppression.
AB - The long-term effect of Helicobacter pylori eradication on the natural history of
duodenal ulcer has been investigated and compared with long-term acid suppression
treatment in an endemic community for infection. Seventy-three patients with
endoscopically verified H. pylori positive active duodenal ulcer disease were
included in this prospective study. Patients were divided into two groups. Group
A patients (n = 39) were given an omeprazole-based triple eradication regimen,
while group B patients (n = 34) were given omeprazole alone followed by long-term
famotidine 20 mg daily as maintenance treatment. A control endoscopy was
performed at the third month of treatment. The bacterium was eradicated in 32
(82%) of group A patients. All patients were followed up for two years and an
endoscopy performed at the end of each year. H. pylori recurred in 13 patients
and the reinfection rate was 44.8% over two years. Duodenal ulcer recurred in
seven of these patients at two years (24.1%). There was a close association
between H. pylori reinfection and ulcer relapse. Group B patients remained H.
pylori positive during the study and the ulcer recurred in five of these patients
(6.6%) despite continuous famotidine treatment. There was no statistically
significant difference in ulcer relapse rate between the groups. These results
suggested that H. pylori eradication is not an absolute solution for duodenal
ulcer disease in high endemic regions and continuous maintenance treatment with
H2-receptor antagonists is still an alternative approach in some chronic
recurrent cases.
PMID- 10692733
TI - A prospective audit of hospital-acquired deep vein thrombosis and pulmonary
embolism.
AB - The incidence of symptomatic deep vein thrombosis and pulmonary embolism acquired
in hospital was studied, and the effectiveness of current thromboprophylaxis was
assessed in an open study of 8648 admissions to the Doncaster Royal Infirmary
between April and July 1994. On admission, all patients were assessed for their
likely risk of thromboembolic problems according to THRIFT criteria. Treatment,
prophylaxis, complications and outcome were recorded on discharge. A high risk
sub-group was followed up for up to 42 days after discharge. The overall rate of
clinically apparent hospital-acquired thromboembolic complications was 0.4% (n =
35). The rate of clinically apparent thromboembolic disease in the high risk
group was 2.1% (n = 17). The incidence of thromboembolic problems appeared not to
be reduce by prophylaxis apparently even when stratified by risk group. These
findings suggest that thromboembolic complications may be less common than would
be expected from published literature. Thromboprophylaxis as currently practised
within our institution does not seem to affect the incidence of deep vein
thrombosis or pulmonary embolism, and these results would appear to argue against
a 'blanket' policy for pharmacological thromboprophylaxis.
PMID- 10692735
TI - An assessment of the efficacy of atorvastatin in treating patients with
dyslipidaemia to target LDL-cholesterol goals: the atorvastatin matrix study.
AB - A total of 531 patients from 57 hospital centres across the UK, who had
previously been treated with lipid-lowering agents in combination or alone, in
whom the degree of cholesterol reduction was insufficient to achieve European
Atherosclerosis Society target levels, were treated with atorvastatin over a 12
week period. The dose of atorvastatin (10, 20 or 80 mg/day) was determined by
assignment of risk based on entry level cholesterol levels and the presence of
other established CHD risk factors. Atorvastatin was successful in achieving
target LDL-cholesterol levels in 86% of mild risk patients, 88% of moderate risk
patients and 52% of high risk patients. Compliance with atorvastatin was 96% and
treatment was well tolerated. This study demonstrates that atorvastatin is
effective in achieving target lipid levels in a large proportion of patients and
that the dose required can be predicted by an assessment of the patient's risk
profile.
PMID- 10692736
TI - Tuberculous perforations of the small intestine.
AB - The hospital records of 58 patients operated on for tuberculous perforations of
the small intestines at our hospital between 1987 and 1996 were reviewed.
Clinical features were non-specific in the majority of the patients.
Pneumoperitoneum on abdominal radiographs was present in only 28 (48.3%)
patients. Forty-five (77.6%) were operated on within 36 hours of perforation.
Surgical management consisted of resection and end-to-end anastomosis (n = 45);
oval excision of the perforation and transverse anastomosis reinforced with an
omental patch (n = 7); ileo-transverse colostomy (n = 5); and peritoneal drainage
only (n = 1). There were 17 deaths (29.3%). Adverse prognostic factors were
operation beyond 36 hours (p < 0.01), multiple perforations (p < 0.001), and
faecal fistula formation (p < 0.01). Mortality was least with early resection and
end-to-end anastomosis of the perforated bowel segment. We conclude that a high
index of suspicion is essential for early diagnosis and optimal treatment of
patients with tuberculous intestinal perforations.
PMID- 10692737
TI - Treatment with carvedilol is associated with a significant reduction in
microalbuminuria: a multicentre randomised study.
AB - Patients with mild to moderate essential hypertension (n = 1570) were enrolled in
a large, multicentre, randomised, open-label study designed to evaluate the
safety and efficacy of different regimens of carvedilol. Reported here are the
effects of carvedilol on microalbuminuria (MAU) in a subset of 876 patients who
underwent MAU assessment (i.e. the Micral-Test) at baseline and at week 12. MAU
was present at baseline in 245 (28%) of these patients. Despite different
magnitudes of blood pressure reduction, improvements in MAU were similar in all
groups (range 54-60%), with complete disappearance occurring in 48-55% of
patients. The decrease in MAU did not correlate with the magnitude of blood
pressure reduction, suggesting a possible renal protective effect exerted by
carvedilol independent of blood pressure reduction mediated by beta-blockade and
vasodilatation.
PMID- 10692738
TI - Attention deficit hyperactivity disorder: possible causes and treatment.
AB - The possible causes of attention deficit hyperactivity disorder are considered,
and the drugs that may be of benefit in treating it. Accurate diagnosis is
essential for effective management. This includes the syndrome itself and
associated conditions. Theories of causation are discussed. These involve the
anatomical substrate but, equally importantly, the role of neurotransmitters; and
the use of tests such as positron emission tomography will undoubtedly increase
understanding. Genetic factors also play a part. Options for treatment are
considered. Evidence supports the effectiveness of stimulant drugs, such as
methylphenidate. Among the justifications for such treatment are the excessive
strains placed on family relationships by the condition, and the disruption of
the child's schooling. It must be carefully planned, and a constant watch kept
for adverse effects. These can include difficulty in sleeping, poor appetite,
loss of weight and tics. Drugs alone, however, are unlikely to help, and
attention must first be given to the situation at home and at school, and how
this can be improved. Treatment is often successful, and it can be a rewarding
condition to treat.
PMID- 10692739
TI - Unstable angina: a review and practical guide to management.
AB - The syndrome of increasing angina leading to myocardial infarction was first
recognised in the 1930s and the term unstable angina coined in 1971 by Fowler.
Since then the importance of acute coronary syndromes as a presentation of
ischaemic heart disease has been fully recognised. Recently several new
pharmacological agents have been developed for the treatment of these syndromes.
We aim to review the current treatments available for unstable angina and give a
practical guide to its management.
PMID- 10692740
TI - New therapeutic approaches for rheumatoid arthritis.
AB - Better understanding of the immunopathogenesis of rheumatoid arthritis over the
past few decades has promoted the innovation of new therapeutic approaches
targeting the disease more specifically. In addition, refinements in the non
steroidal anti-inflammatory drugs (NSAID) may offer advantages for patients with
RA. This brief review reports and analyses some of the important aspects of these
new therapies available for treatment of RA and in which situations you might
consider each. Before using any of these agents, physicians should become
thoroughly familiar with the package inserts.
PMID- 10692741
TI - Nutritional factors in osteoporosis.
AB - Nutritional factors are important but correctable factors in the pathogenesis of
osteoporosis. The rate of bone loss in the elderly can be reduced and the peak
bone mass in the young can possibly be increased by dietary manipulation, thereby
reducing the risk of fracture. Dietary manipulation likely to be of benefit are
increased calcium intake, increased vitamin D intake, moderate reduction in
intake of salt protein, caffeine and phosphate and increased intake of potassium
and magnesium. The possible mechanisms by which these dietary factors influence
bone metabolism are discussed.
PMID- 10692742
TI - Alcohol, drugs and stigma.
AB - Alcohol and drug-related problems are common in clinical populations but are
often stigmatized by the public and the professions. These attitudes may
interfere with patients obtaining effective help. The reasons for these barriers
are explored, including the views that these problems are self-inflicted--and
therefore less worthy of help--and the stereotypes and resistances that abound in
working with those who have become addicted. Training and public education may go
some way to improve this situation.
PMID- 10692743
TI - Naratriptan.
AB - The new 5-HT1B/1D agonist naratriptan, introduced in many countries in 1997 and
1998 for the acute treatment of migraine, was designed to complement the
sumatriptan portfolio of offerings (including the injection, the tablets, the
nasal spray, and in some countries, the suppository) by offering patients
excellent tolerability and a sustained duration of action. Clinical studies on
naratriptan, including more than 4000 patients treating more than 15,000 migraine
attacks, show that naratriptan tablets 2.5 mg are distinguished from other 5
HT1B/1D agonists for migraine on the basis of their excellent tolerability
profile, which does not differ from that of placebo. In addition to its
tolerability, naratriptan tablets 2.5 mg possess a long duration of action with a
low incidence of headache recurrence (17-28% in phase II and III clinical
trials). With its tolerability profile and long duration of action, naratriptan
tablets 2.5 mg may be particularly appropriate as a single-dose alternative to
NSAIDs and analgesics, which often are not effective in migraine but are used
because of tolerability considerations.
PMID- 10692744
TI - Acetazolamide-induced Gerstmann syndrome.
AB - Acute confusion induced by acetazolamide is a well known adverse drug reaction in
patients with renal impairment. We report a case of acetazolamide-induced
Gerstmann syndrome in a patient with normal renal function, to highlight
predisposing factors that are frequently overlooked.
PMID- 10692745
TI - A rare case of cutaneous kaposiform haemangioendothelioma.
AB - Kaposiform haemangioendothelioma is a rare vascular neoplasm with a wide
anatomical distribution. We describe an unusual case arising in the post
auricular skin of a male infant overlying a ventriculoperitoneal shunt.
PMID- 10692746
TI - Oral gastrografin in neonates: a note of caution.
AB - Hyperosmolar feeds are known to increase gastrointestinal permeability,
predisposing to absorption of toxins. They are also associated with necrotising
enterocolitis (NEC) in neonates. A case of a neonate with suspected NEC who died
following Gram-negative septicaemia possibly related to oral gastrografin is
reported. Hyperosmolarity of gastrografin may have caused complete loss of
mucosal integrity in the compromised bowel leading to Gram-negative septicaemia.
PMID- 10692747
TI - Fever, rash and worsening of asthma in response to intravenous hydrocortisone.
AB - We describe a case of a hypersensitivity reaction to intravenous hydrocortisone
in a 64-year-old female with asthma, and briefly review other cases.
PMID- 10692748
TI - Lipid-lowering drugs: do the differences matter?
PMID- 10692749
TI - IIb/IIIa or not IIb/IIIa? That is the question.
PMID- 10692750
TI - Cefaclor af versus amoxycillin/clavulanate in acute bacterial exacerbations of
chronic bronchitis: a randomised multicentre study.
AB - Cefaclor and amoxycillin/clavulanate are active against Haemophilus influenzae,
Streptococcus pneumoniae, Moraxella catarrhalis and Staphylococcus aureus-
pathogens commonly associated with acute exacerbations of chronic bronchitis
(AECB). This randomised, parallel-group, single-blind, multicentre study
investigated the comparative efficacy and safety of 7-day treatment regimens of
cefaclor AF (750 mg b.d. [n = 73]) and amoxycillin/clavulanate (875/125 mg b.d.
[n = 72]) in AECB. A favourable clinical response was obtained in 95.9% of
patients on cefaclor AF and 97.2% of patients on amoxycillin/clavulanate. There
were no statistically significant differences between the groups for improvement
in clinical response measured by pulmonary peak expiratory flow (PPEF), or for
common symptoms associated with AECB. Both agents were well tolerated, with no
statistically significant differences in overall safety; however, nausea and
vomiting, and abdominal pain, the most frequently occurring adverse events in the
amoxycillin/clavulanate group, were not reported in the cefaclor group. In
conclusion, cefaclor AF and amoxycillin/clavulanate have similar efficacy and
safety profiles in the treatment of AECB.
PMID- 10692751
TI - The effect of valsartan and captopril on lipid parameters in patients with type
II diabetes mellitus and nephropathy.
AB - The study compared valsartan 80 mg or 160 mg o.d. with captopril 25 mg t.i.d. or
placebo on plasma lipids in normotensive and treated hypertensive patients with
type II diabetes and microalbuminuria. One hundred and twenty-two adult
outpatients were randomised to receive either valsartan 80 mg or 160 mg,
captopril 25 mg or placebo for 360 days. Changes from baseline to endpoint in
plasma lipid parameters were measured. The primary criterion for tolerability was
the incidence of adverse events. All treatment groups showed minor changes in
lipid parameters. Triglyceride increased by 2.7% (valsartan 160 mg) to 9.1%
(placebo). Total cholesterol decreased under valsartan 80 mg, while other groups
showed increases of up to 0.031 mmol/l. Decreases in total cholesterol (p =
0.018), apolipoprotein B (p = 0.042) and apolipoprotein A1 (p = 0.025), were
significant for the comparison of 80 mg valsartan and captopril. Valsartan 80 mg
or 160 mg o.d. does not cause deleterious changes in the diabetic lipid profile
and, unlike captopril, is not associated with dry cough.
PMID- 10692752
TI - A dose-defining study of sumatriptan suppositories in the acute treatment of
migraine.
AB - In this dose-ranging, randomised, multinational, multicentre, double-blind,
placebo-controlled, parallel group study, 431 patients treated a single migraine
attack with study medication: sumatriptan suppository 6 mg, 12.5 mg, 25 mg, 50
mg, 100 mg, or placebo. Patients were treated in the clinic with a single dose in
suppository form. All doses of sumatriptan, except 6 mg, were significantly
better than placebo (p < 0.004) and achieved similar rates of headache relief
within two hours of dosing. The highest response rate was in the 25 mg group
(72%) compared with placebo (37%) (p < 0.001). Fewer patients required rescue
medication in the active groups (1% 100 mg to 13% 6 mg) compared with placebo
(17%), and more patients were able to work and function normally two hours after
dosing (41%, 100 mg; 20%, placebo). The overall incidence of adverse events was
similar in the placebo, 6 mg and 12.5 mg groups (14-17%) but higher in the 25 mg,
50 mg and 100 mg groups (25%, 32% and 29% respectively). Analysis of plasma
sumatriptan levels indicated rapid rectal absorption for all doses (median tmax =
1.0 hr). It is concluded that sumatriptan, in doses above 6 mg, is an effective
and well tolerated treatment for acute migraine. From this study doses of 12.5 mg
and 25 mg sumatriptan were identified as having the best efficacy/safety profile
and were evaluated further.
PMID- 10692753
TI - Rational prescribing: practice audit and drug switch in dyspepsia management.
AB - Growing demands on limited healthcare resources and budgets have led to an
increased focus on the costs associated with the purchase of drugs. Consequently,
approaches to treatment for various disease states are now dictated not only by
issues such as best medical benefits, but also by the cost of the drug that is
used. As such, drug-switching strategies have become increasingly common practice
where, although the clinical benefits offered by the various medications for a
specific condition may be similar, the cost differentials are notable.
Application of this switch procedure has recently been assessed in the context of
the management of acid-related gastrointestinal disorders and has demonstrated
that switching patients to therapy with the proton pump inhibitor lansoprazole
from H2-receptor antagonists or other proton pump inhibitors not only offers
therapeutic advantages but also has important financial implications in general
practice with regard to cost savings.
PMID- 10692754
TI - Dissolution of thrombus formed during direct coronary angioplasty with a single
10 mg intracoronary bolus dose of abciximab.
AB - Direct coronary angioplasty with stent implantation is an effective treatment for
acute myocardial infarction. The use of adjunctive abciximab, a platelet
glycoprotein IIb/IIIa receptor antagonist is expensive. We report on three cases
of direct coronary angioplasty complicated by extensive thrombus formation that
were successfully treated with attenuated dosing of abciximab via the
intracoronary route. All patients presented with acute myocardial infarction
complicated by cardiogenic shock or eminent cardiogenic shock. Abciximab was
administered after balloon dilatation when extensive thrombus formation was noted
and persisted despite repeated inflations. In all three patients a single 10 mg
vial of intracoronary abciximab was administered, resulting in complete
dissolution of thrombus, allowing successful deployment of stents. Thus, a single
10 mg intracoronary bolus dose of abciximab may be sufficient to achieve high
local concentrations of antiplatelet activity. This facilitates thrombus
dissolution and allows the safe deployment of a stent to normalise intracoronary
rheology.
PMID- 10692755
TI - Comparison of therapy with simvastatin 80 mg and atorvastatin 80 mg in patients
with familial hypercholesterolaemia.
AB - This study compared the efficacy of simvastatin 80 mg and atorvastatin 80 mg in
the treatment of 26 patients with familial hypercholesterolaemia over 12 weeks
using an open crossover trial format. Both, similarly, reduced LDL by 47 +/- 13%
and 43 +/- 16% and median triglycerides by 22% and 27% respectively. However,
atorvastatin reduced HDL by 2 +/- 24% compared with 8 +/- 30% increase with
simvastatin (p = 0.05) affecting the LDL:HDL ratio achieved (4.478 +/- 1.56 vs
3.74 +/- 0.93, p = 0.001). Atorvastatin raised median fibrinogen by 15% compared
with a non-significant 5% increase with simvastatin (p = 0.05). Simvastatin
reduced lipoprotein (a) by a median 20% compared with baseline (p = 0.05)
compared with 5% for atorvastatin. Side-effects, mostly gastrointestinal, were
seen in four patients (16%) with atorvastatin compared with one case of myalgia
with simvastatin (4%). We conclude both drugs are equally effective in LDL
reduction but that simvastatin is superior in raising HDL and causes fewer side
effects. These results require confirmation in larger studies.
PMID- 10692756
TI - Pivmecillinam for the treatment of acute uncomplicated urinary infection.
AB - Pivmecillinam is a beta-lactam antimicrobial marketed almost two decades ago. It
has been used widely for the treatment of acute cystitis in selected areas of the
world, particularly in Scandinavia. With increasing resistance of community
Escherichia coli isolates to trimethoprim and trimethoprim/sulphamethoxazole, as
previously observed for ampicillin and sulphonamides, reassessment of empiric
antimicrobial regimens for acute uncomplicated urinary infection is necessary.
Thus, it is timely to revisit the role of pivmecillinam for the treatment of
acute cystitis. Clinical studies document the efficacy of this antimicrobial with
short course therapy for acute cystitis, and clinical practice in countries where
it has been used for many years confirms its efficacy and tolerability. If this
agent were more widely used for empiric treatment for acute cystitis, use of
antimicrobials such as the quinolones might be avoided. Further trials to define
the comparative efficacy of pivmecillinam with other antimicrobials, and further
studies of community resistance in E. coli isolates to this agent are needed.
PMID- 10692757
TI - Glycoprotein IIb/IIIa antagonists: do they have a role in the management of
unstable angina?
AB - Plaque rupture, platelet aggregation and thrombosis have central roles in the
pathogenesis of acute coronary syndromes. Despite several trials showing the
benefit of aspirin and heparin in patients presenting with unstable angina and
acute myocardial infarction, these patients are still at risk. This has prompted
the development and evaluation of several new therapeutic agents including low
molecular weight heparin, new antiplatelet drugs (e.g. ticlopidine and
clopidogrel), direct thrombin inhibitors, and intravenous and oral glycoprotein
IIb/IIIa antagonists. The IIb/IIIa receptor is the final common pathway involved
in platelet aggregation. Thus, whatever the stimulus for platelet activation,
subsequent aggregation is mediated by the IIb/IIIa receptor binding fibrinogen. A
variety of antibody, peptide and non-peptide compounds that block the IIb/IIIa
receptor have been developed, and several studies have investigated the role of
these agents in patients with acute coronary syndromes both within and outside
the setting of percutaneous intervention. This article summarises the studies to
date using IIb/IIIa antagonists, and discusses their role in patients with non-ST
segment elevation acute coronary syndromes.
PMID- 10692758
TI - Parkinson's disease surgery: advances and future strategies.
AB - The recent resurgence of surgical treatment of Parkinson's disease has generated
enormous interest in the scientific community and with the general public. Both
ablation (pallidotomy, thalamotomy), deep brain stimulation (thalamus, pallidum,
subthalamus), and neural transplantation (human, porcine) have been demonstrated
to be effective for specific subsets of Parkinson's disease patients. Future
studies need to define better the ideal target sites and lesion volume of
ablation and stimulation procedures, and optimising graft survival in neural
transplantation. Numerous potential surgical interventions are currently being
evaluated.
PMID- 10692759
TI - The original sin of madness--or how psychiatrists can stigmatize their patients.
AB - A stigma is a mark of infamy or disgrace. People who are stigmatized are subject
to abuse and social exclusion. Negative attitudes towards people with mental
illness are attributed to stigma. In the literature, stigma is regarded as
something that is attached to a person--like a badge or label. This is undermined
by two facts. Firstly, it is the person who is regarded as disgraceful, not the
illness or diagnosis, and secondly, the diagnosis of mental illness is itself
evaluative. Mental illness is by definition bad, so to be diagnosed as mentally
ill is to be defined as bad (or somehow wrong). The stigmatization of the
mentally ill will not stop until this negative evaluation is removed from
diagnosis.
PMID- 10692760
TI - Calcium dobesilate: pharmacological profile related to its use in diabetic
retinopathy.
AB - Calcium dobesilate (Doxium) is used in the treatment of diabetic retinopathy.
Clinical studies show a slowdown of the progression of the disease after long
term oral treatment. The main action of the drug is related to a reduction of
microvascular permeability as measured by different parameters and methods
(vitreous fluorophotometry, retinal haemorrhages, skin capillary resistance,
blood albumin leakage, blood viscosity) leading to improved visual acuity. The
pharmacological activity may be explained in part by the antioxidant properties
of calcium dobesilate and its action on endothelium through the synthesis of
nitric oxide, increasing the endothelium-dependent relaxation. The antioxidant
effect was demonstrated in different in vitro and in vivo models by decreasing
the peritoneal permeability in rats induced by pro-oxidant substances. Moreover,
vascular leakage was also decreased by calcium dobesilate in a reperfusion model
in streptozotocin induced diabetic rats after ischaemia of the central artery of
the retina. Doxium may also preserve vascular endothelial function by acting
directly as antioxidant to protect lipids from peroxidation.
PMID- 10692761
TI - Local anaesthetic circumcision in adults.
AB - Circumcision is a simple operation often performed under general anaesthesia. In
this study, we assessed the suitability of local anaesthesia in 38 adult
patients, 79.4% of whom suffered little or no discomfort. Infiltration of local
anaesthesia caused moderate pain in 10 patients (29.4%) and severe pain in only
one. The circumcision itself caused moderate pain in three patients and severe
pain in another three (8.8%); 85% of patients expressed complete satisfaction.
PMID- 10692762
TI - Cystic lymphocytic hypophysitis, visual field defects and hypopituitarism.
AB - A 45-year-old man presented with anterior pituitary failure, requiring thyroxine,
hydrocortisone and androgen replacement. An MRI scan revealed a large cystic
pituitary mass and thickening of the pituitary stalk. Over three years, diabetes
insipidus and bitemporal hemianopia developed and the cystic mass had enlarged on
MR scanning. Transphenoidal resection was performed with normalisation of the
visual fields. Histology revealed lymphocytic hypophysitis, which is rare in men.
The presentation with cystic enlargement is unique.
PMID- 10692763
TI - Iatrogenically revealed myasthenia gravis.
AB - Myasthenia gravis is rare. When it presents unusually, making a diagnosis is
doubly difficult. We present an unusual case where an 'everyday' medication
unfortunately precipitated a myasthenic crisis in an unsuspecting individual.
PMID- 10692764
TI - Independence, journals and editors.
PMID- 10692765
TI - On the influence of diet and exercise on lipid fractions.
PMID- 10692766
TI - One-month mortality rate after liver transplantation for parenchymal cirrhosis:
analysis of risk factors in a ten year period.
AB - Accurate prediction of short-term survival rate after liver transplantation is
one way of selecting recipients and should improve organ allocation. We observed,
during the first ten years of our program a striking decline in postoperative
mortality with time, a well known observation in Europe as well as in the United
States. In 65 adults with parenchymal cirrhosis having received a liver
transplant between 1984 and 1994, we examined the possible influence of various
preoperative risk factors on one-month mortality rate which was 13.8% in this
series. Univariate analysis led to the identification of five significant risk
factors: date of transplantation, low serum sodium, previous history of jaundice,
ascites and encephalopathy. In the final multivariate analysis however, the date
of transplantation emerged as the sole predictive factor of early mortality rate.
Therefore, factors such as pretransplantation state of the patient and poor
hepatic reserve are counterbalanced by the improvement of surgical skill and
other technical aspects, as well as by better perioperative management which have
all contributed to the improved results of liver transplantation with time.
PMID- 10692767
TI - Histopathological assessment of the prophylactic effect of gingko-biloba extract
on intestinal ischemia-reperfusion injury.
AB - In this experimental study, the prophylactic effects of Gingko-Biloba Extract
(GBE) were examined after experimental ischemia on intestinal wall damage. 50
Wistar-Albino rats (2.5 month old) were gathered and separated into 5 groups
(n:10). Group 1 was subjected to a laparotomy (sham-operated group) whereas all
other experimental groups were subjected to an occlusion of their superior
mesenteric arteries for 30 minutes and a period of 20 minutes reperfusion
following occlusion. Group 2 was not given any prophylactic agent during the
experiment (untreated control group). GBE was administered in a dosage of 50
mg/kg (i.v.) as a prophylactic agent to Group 3 one hour prior to laparotomy
whereas Group 4 was given GBE at 50 mg/kg (i.v.) just before ischemia. Group 5
was given GBE in the same dosage just before reperfusion. Immediately after
reperfusion, a biopsy was taken from the ileum (10 cm proximity to ileocaecal
valve) for histopathological assessment. A significant prophylactic effect of GBE
was observed in Group 5 in which GBE was administered just before reperfusion.
PMID- 10692768
TI - Endoscopic therapy of Barrett's oesophagus: critical review.
AB - Barrett's oesophagus is known as one of the most important risk factor of
oesophageal adenocarcinoma. Because of the increasing incidence of these latter,
many endoscopic methods such as argon plasma coagulation, photodynamic therapy or
endoscopic mucosal resection are now in evaluation in order to eradicate
Barrett's oesophagus or to treat dysplasia and early cancers arising from this
metaplasia. The aim of this paper is to comment these techniques and discuss
their usefulness.
PMID- 10692769
TI - The role of the E-cadherin/catenin complex in gastrointestinal cancer.
AB - Cancer is a genetic disease. The unstable genome of cancer cells causes tumour
progression through multiple alterations in suppressor and promoter genes,
leading to loss of homeostatic and gain of oncogenic functions. Invasion is the
critical step in the acquisition of malignancy. It implicates a continuous
molecular conversation of the cancer cells with other cells and with the
extracellular matrix in which adhesion molecules are crucial. One of these, E
cadherin, is discussed in the present review. E-cadherin is a transmembrane
glycoprotein that forms a complex with cytoplasmic proteins, termed catenins
because they link E-cadherin to the actin cytoskeleton. E-cadherin/catenin
mediated intercellular adhesion and communication is mainly homophylic homotypic.
There is compelling evidence from experiments in vitro as well as in vivo to
accept that the E-cadherin/catenin complex acts as an invasion suppressor. The
mechanism of this action is not only through cell-cell adhesion but also through
transduction of signals to the cell's motility system. In the replication error
positive human colon cancer cell line HCT-8, the alpha E-catenin gene CTNNA1 is
an invasion suppressor gene. Here, the transition from the non-invasive to the
invasive state was prevented by introduction into the unstable non-invasive cells
of either an extra CTNNA1 or a wild type hMSH6 mismatch repair gene. beta-catenin
also participates at a complex which comprises the adenomatous polyposis cancer
protein APC. In colorectal cancer, mutation of either APC or beta-catenin is
oncogenic. Downregulation of the E-cadherin/catenin complex may occur in several
ways amongst which are gene mutations, methylation of 5'CpG dinucleotides within
the promotor region of E-cadherin, tyrosine phosphorylation of beta-catenin, cell
surface expression of proteoglycans sterically hindering E-cadherin and
proteolytic release of fragments from the extracellular part of E-cadherin.
Upregulation of the E-cadherin/catenin complex has been realized with a series of
agents, some of which can be used therapeutically. In most human gastrointestinal
cancers the E-cadherin/catenin or related complexes are disturbed and this
underscores their pivotal role in the progression of these tumours. Mutations of
the E-cadherin gene, including germline mutations, occur in diffuse gastric
carcinoma, CpG methylation around the promotor region of E-cadherin in
hepatocellular carcinomas and mutations of the APC tumour suppressor gene or in
the beta-catenin oncogene in most colorectal cancers. The literature agrees about
the disturbance of immunohistochemical patterns of E-cadherin and catenin
expression in gastrointestinal cancers. Conflicting opinions do, however, exist
about the prognostic value of such immunohistochemical aberrations. We doubt that
immunohistochemistry of E-cadherin or catenins add prognostic value to the
already used histological grading systems. In our opinion the major benefit from
understanding of the E-cadherin/catenin-mediated pathways of invasion will be the
development of new anti-invasive treatment strategies.
PMID- 10692770
TI - Haemochromatosis and HFE gene.
AB - The discovery of the HFE gene has improved classification and diagnosis of iron
overload. Most patients with a phenotypic diagnosis of haemochromatosis are
homozygote for the C282Y mutation. Among those with other genotypes, only
compound heterozygotes, who present the C282Y mutation on one chromosome and the
H63D on the other, may present with haemochromatosis, but with a low penetrance
and a mild expression. Other patients usually present with another cause of iron
overload, such as insulin resistance, alcoholic liver disease or liver cirrhosis.
The practical management of haemochromatosis has been greatly modified, since
liver biopsy is no more necessary for diagnosis in C282Y homozygotes, and is only
needed for exclusion of cirrhosis. Family screening has also greatly benefited
from genotyping.
PMID- 10692771
TI - Diagnosis and treatment of hepatocellular carcinoma.
AB - Several advances have been produced in the diagnosis and treatment of patients
with hepatocellular carcinoma. It is possible to diagnose the neoplasm at an
early stage when radical treatment options may be applied. The criteria to apply
them successfully have been refined and the expected outcome has been improved,
but we still lack a useful treatment for the vast majority of patients who are
still diagnosed at an advanced stage. Efforts have to be done during the next
years to develop such an option (perhaps based on gene manipulation) and until
then the management of this tumour will still constitute a challenge for
physicians taking care of patients with this neoplasm.
PMID- 10692772
TI - NSAID use and abuse in gastroenterology: refractory peptic ulcers.
AB - With current antiulcer therapies to eliminate H. pylori infection, non-steroidal
antiinflammatory drug use is the main factor involved in resistant peptic ulcers
which must be defined as those ulcers that do not heal after 6 (duodenal ulcers)
or 8 (gastric ulcers) weeks of treatment with proton pump inhibitors, despite H.
pylori eradication. NSAID use (especially aspirin abuse) in patients with
resistant ulcers is often surreptitious. Ulcers tend to complicate with stenosis
and bleeding, commonly change site, are multicentric and have poorly defined
margins. These patients should never undergo surgery unless they develop
uncontrolled complications, since ulcer recurrence is the rule. Analgesic abuse
and personality disorders might present in some of these patients. Refractory
ulcers with no evidence of NSAID use and no evidence of H. pylori infection are
rare but not exceptional. Smoking and genetic background seem important factors
in patients with this type of ulcers. Idiopathic basal gastric acid
hypersecretion might be important in a few patients, but the Zollinguer-Ellison
syndrome must be ruled out.
PMID- 10692773
TI - Novel nonsteroidal anti-inflammatory drugs.
AB - The authors first briefly review how the concept of COX-2 selectivity was brought
to light, then tested against the known gastrotoxicity ranking of currently used
NSAIDs, from the old classics to the most recent. One truly selective COX-2 agent
-celecoxib--is now being marketed in an ever increasing number of countries. So
far it seems to keep its main promises, i.e. high--albeit not total--safety
regarding gastrointestinal adverse effects, and undisturbed platelet function.
Association with warfarin drugs seems to raise no problems, but one should still
be wary of possible renal side-effects. Efficacy, at least as assessed in
osteoarthritis and rheumatoid patients, appears satisfactory. However, treatment
of intense inflammatory crises, such as gout or ankylosing spondylitis, has not
been assessed, as yet. Another COX-2 agent--rofecoxib--is on the brink of being
released. Its even more potent COX-2 selectivity raises new issues. What about
some COX-1 activity that several authors detected in rheumatic synovitis? On the
other hand, in particular circumstances, organs such as the stomach, the kidney
and small blood vessels, seem to have their homeostasis partly controlled by COX
2 mechanisms also. These questions should be answered soon, whilst clinical
experience with the COX-2 agent builds up.
PMID- 10692774
TI - Non-steroidal antiinflammatory drugs and the intestine.
PMID- 10692775
TI - Hepatitis C recurrence after liver transplantation.
AB - Hepatitis C-related cirrhosis is the major indication for liver transplantation
(LT). This disease recurs histologically in nearly all the HCV-infected patients
during the first postoperative year. Chronic hepatitis C evolves to cirrhosis in
20% of the cases within 5 years after LT. However, the 5-year survival for a HCV
infected recipient is still comparable to that of a patient grafted for another
indication; it will become worse later. High viremia after LT is associated with
a more severe liver recurrent disease. The influence of viral genotype remains
controversial. The impact of the type of immunosuppression on HCV recurrence is
unclear. Steroids, that increase viremia, might have a deleterious effect on the
outcome of chronic HCV-disease after LT. Antiviral combined therapy (Interferon +
Ribavirin) soon after transplantation, before disease recurrence, is probably the
best treatment at the present time; this remains still unproven.
Retransplantation for HCV recurrent cirrhosis allows a 60% survival at 1 year.
PMID- 10692776
TI - Multimodality treatment of cancer of the digestive tube: the standard in 1998.
Colorectal cancer.
PMID- 10692777
TI - Treatment of inflammatory bowel disease with azathioprine: how to use it in 1999.
AB - Azathioprine and 6-mercaptopurine are effective drugs in the management of
steroid dependent and chronic active inflammatory bowel diseases. They are also
well tolerated on the long term. However, their use is still hampered by some
drawbacks including delay before efficacy, 20-35% of non responders, relapse at
withdrawal of the drugs, possible bone marrow toxicity and other side effects.
During the last few years, these drawbacks have been challenged by important
studies showing that a better knowledge of the metabolism of these drugs may help
to improve their use.
PMID- 10692778
TI - New drugs in chronic hepatitis B.
PMID- 10692779
TI - A rare cause of biliary pain in Belgium.
AB - Ascaris lumbricoides is the most frequent human helminthic parasite. Usually
human ascariasis is poorly symptomatic but complications can arise due to worm
migration. Erratic worm migration into the biliary tree is a rare but threatening
condition regarding the associated complications: cholecystitis, pancreatitis,
obstruction of bile ducts, liver abcesses and recurrent pyogenic cholangitis. We
describe a case of a young belgian women suffering from recurrent biliary colics
over a period of eight months with repeated normal ultrasound findings. ERCP
proved being the only effective diagnostic procedure for a living biliary worm,
which was successfully removed with a balloon catheter.
PMID- 10692780
TI - Diffuse liver angiosarcoma and cerebral cavernous angiomas in a young patient.
AB - A case of a thirty-nine year old woman with cerebral cavernous angiomas who
developed anaemia and thrombocytopenia secondary to diffuse liver angiosarcoma is
reported. This unique association of liver angiosarcoma and cerebral cavernous
angiomas may suggest that this tumour may potentially develop from benign
vascular lesions. Hematologic abnormalities in angiosarcomas are moreover
reviewed based on recent literature search.
PMID- 10692781
TI - The mesencephalic trigeminal nucleus in the cat.
AB - This review is a concise summary of our current knowledge about the MTN
neuroanatomy which in turn is necessary to understand the neurochemistry of this
nucleus in the cat. In order to solve the puzzle of neurotransmitter related
changes in the synaptic and functional organization of the MTN, we provide a
comprehensive description of the neurotransmitter content of MTN neurons.
Particular emphasis is given to identifying the possible physiological
involvement of MTN inputs in the transmission of proprioceptive information at
the first synaptic relay. It is shown that under normal circumstances the large
MTN neuron subpopulation contains only Glu that is a strong candidate for a major
neurotransmitter in this brain region. However, certain small MTN neurons, most
likely interneurons, are found to be GABAergic. Furthermore, NOS immunoreactivity
can be detected in the caudal as well as the mesencephalic-pontine junction parts
of the MTN and this suggests a mediatory role for NO in some aspects of synaptic
transmission in the MTN. The divergent neurochemical content of the cells in the
nucleus, should it exist, is likely to be linked with different neuronal
functions. Remarkably, no immunoreactivity to any of the neuropeptides examined
is observed in the cell bodies of MTN neurons and only fibers and their terminals
show peptide-immunolabeling. Most of the labeled peptidergic fibers have
immunopositive varicosities that form pericellular basket-like arborizations
around unlabeled MTN perikarya. It is predicted that under normal conditions the
pericellular arborizations can function as an intranuclear key communication
medium between immunopositive projections and immunonegative MTN neurons in the
proprioceptive information processing. The levels of transmitter substances in
MTN neurons may vary in case of marked changes in the environmental conditions.
Axotomy-induced alterations include a long-lasting decrease in the content of
CaBPs produced in MTN neurons and/or de novo synthesis of GAL, NPY and CGRP, thus
implying the interactive nature and a previously unsuspected neurochemical
plasticity of MTN neurons. The newly synthesized neuropeptides can enhance
neuronal survival and neurite regeneration. Our results support the assumption
that a peptide involvement in the proprioceptive function develops mainly in
abnormal conditions. Taken together with the existing neuroanatomical and
electrophysiological data, the present results give strong evidence for the
occurrence of both excitatory (Gluergic) and inhibitory (GABAergic) transmission
in the cat MTN. In addition, evidence is also provided that the MTN receives
synaptic inputs from peptidergic and catecholaminergic fibers and these possibly
play a significant role in the integration and transmission of trigeminal
proprioceptive information. These findings have confirmed the existence of a
large number of synaptic contacts in the cat MTN with specific morphological
features of their boutons and with presumably different neurotransmitter release
from the synaptic vesicles. In this way, knowledge of the origin and
neurotransmitter nature of the fibers providing the synapses would facilitate the
understanding of the important role of MTN neurons responsible for proprioception
in this region.
PMID- 10692782
TI - Development and regenerative capacity of descending supraspinal pathways in
tetrapods: a comparative approach.
AB - Throughout tetrapods a basic pattern in the organization of descending
supraspinal pathways is present. The most notable difference between nonmammalian
tetrapods and mammals is the apparent absence of somatomotor cortical areas
giving rise to long descending projections to the spinal cord. The phylogenetic
constancy of descending supraspinal pathways, at least of those arising in the
brain stem, probably implies a comparable pattern of development, presumably a
developmental sequence in the formation of these central motor pathways. For
studies on the development of motor systems, anurans such as the clawed toad,
Xenopus laevis, chicken embryos, and opossums are very attractive animals.
Moreover, in these species as well as in rodents in vitro approaches can be used.
In the present survey, current knowledge on the neurogenesis, axonal outgrowth,
synaptogenesis, and developmental plasticity of the central motor pathways in
tetrapods including the sparse data available for man, is discussed. These data
are placed in the perspective of the development of the spinal cord and, where
possible, correlated with functional data. Emphasis is on the clawed toad, X.
laevis, chicken embryos, and opossum and rodent data. The outgrowth of axons of
descending supraspinal pathways can be regarded as the result of a series of
distinct processes, which may be expressed in a coordinated program: (1) the
outgrowth of axons and selection of pathways to their appropriate destination;
(2) dendritic outgrowth and formation of specific dendritic morphology; (3)
selection of specific targets and collateralization by axons; (4) elimination of
incorrect and redundant synapses, axonal and dendritic branches, and of
mismatched neurons; and (5) functional refinement of synaptic connections. Tracer
and transmitter immunohistochemistry in Xenopus laevis showed that from the
moment cell division stops, an axon is formed followed by dendrites which emerge
from the cell body. At the beginning of the cell differentiation phase the
production of the cell-specific neuroactive substances takes place. Initial
outgrowth is in a specific direction for each class of neuron. It is likely that
all descending supraspinal pathways arise in a similar way. In the spinal
projections of each of the descending supraspinal pathways three stages can be
distinguished: (1) an initial stage of outgrowth to the spinal cord, (2) a short
"waiting" period after which collaterals enter the spinal gray matter, and (3)
myelination of axons. An "overshoot" of spinal projections is particularly
evident for the mammalian corticospinal tract. The pattern of early descending
axonal tracts appears to be similar in all vertebrate groups. Early axons lay
down an axonal scaffold containing guidance cues that are available to later
generated growth cones. Throughout vertebrates including man, the fasciculus
longitudinalis medialis (flm) is the first descending pathway to be formed.
Interstitiospinal fibers "pioneer" this tract, and are joined by reticulospinal
fibers. Vestibulospinal fibers (the medial vestibulospinal tract) follow much
later. The lateral vestibulospinal tract takes a separate course through the
brain stem. Late-arriving fiber tracts such as the rubrospinal and corticospinal
tracts probably have their own mechanism of selecting the appropriate pathway.
The formation of the descending supraspinal pathways occurs according to a
developmental sequence. In all tetrapods studied, reticulospinal and
interstitiospinal fibers reach the spinal cord first, followed by vestibulospinal
fibers and, much later, by rubrospinal and, if present, corticospinal
projections. A special case is presented by anurans which in fact have two motor
systems, a primary, transient motor system and a secondary, definitive motor
system. Reticulospinal, interstitiospinal and vestibulospinal fibers innervate
the spinal cord very early in development, well before the development of the
hindlimbs. Rubrospinal fibers in
PMID- 10692783
TI - [Extracorporeal liver support systems].
AB - Acute liver failure is very life-threatening since the conventional medical
treatments have little effects on the clinical outcome. Artificial liver support
systems based on blood detoxification alone have proven ineffective because they
cannot correct the severe biochemical disorders. An effective liver support
system should be capable of carrying out essential functions such as phase I
reaction in which lipid-soluble toxic substance are rendered water-soluble by the
enzyme system of the cytochrome P450 and NADPH-cytochrome reductase, and are
therefore conjugated by the phase II reaction, before excretion. Liver support
systems should be capable of sustaining patients with fulminant liver failure
until an organ is available for liver transplantation (bridging treatment), or
improving the survival in patients for whom liver transplantation is not a
therapeutic option. Recent advances in cell biology and tissue culture techniques
have led the way for potential clinical use of isolated hepatocytes so that they
are now an important element of bioartificial liver support devices. Some of
these systems are currently under clinical investigation in the USA and Europe,
and the results of the prospective controlled trials will be soon available.
PMID- 10692784
TI - [General features and strategy in the diagnosis of prostatic carcinoma].
AB - Prostate cancer (PCa) is the most commonly diagnosed cancer in men as well as the
second leading cause of cancer death. Age, family history and race are proved
risk factors for developing a PCa. Prostate specific antigen (PSA) in combination
with the digital rectal examination (DRE) has proven to be an essential element
in early prostate cancer detection. Enthusiasm for using transrectal ultrasound
(TRUS) alone to identify early prostate cancer has not been demonstrated with
longer follow-up. The major role of TRUS today is to ensure accurate wide-area
sampling of prostate tissue in men with PCa suspicion. This is best accomplished
by targeted biopsy of TRUS-suspicious lesions and systematic biopsy of areas
without hypoechoic lesions. Urologists recommend digital rectal examination and a
PSA blood test annually starting at age 50.
PMID- 10692785
TI - [Staging and therapeutic options in local prostatic carcinoma].
AB - Since the introduction of prostate specific antigen (PSA) into widespread use in
clinical practice for early detection of prostate cancer (PCa), in combination
with digital rectal examination (DRE), there has been a marked increase in the
incidence of localized, potentially curable, disease coupled with a simultaneous
decline in regional and metastatic prostate cancer in the least years. After the
diagnosis of adenocarcinoma of the prostate has been histologically confirmed, an
accurate assessment of the stage--or extent--of the disease should be made. We
will provide a critical assessment of the currently employed PCa staging
modalities. Therapeutic options in locally defined PCa are analyzed.
Intracapsular PCa (T1a-T2b N0 M0) is preferably managed by radical prostatectomy,
"insignificant" cancers may be treated by watchful waiting. The outcome of
irradiation is not as predictable as radical surgery. Neoadjuvant treatment with
radical prostatectomy in locally advanced PCa is probably not as efficient as
believed; in some instances the value of adjuvant treatment is undecided. As it
seems irradiation in conjunction with androgen deprivation can equal efficacy of
surgery.
PMID- 10692786
TI - [Perineal radical prostatectomy].
AB - At the beginning of the 1980's. P. Walsh and other published their works which
dealt with the anatomy and technique of radical retropubic prostatectomy (Reiner
1979; Walsh 1982 + 1983). Since then this operative access carried through
simultaneously with an iliacal lymphadenectomy became more and popular. The
perineal approach become less important, many urologists had no longer the
opportunity to learn this operation. With the introduction of the laparoscopic
lymphadenectomy there has been a renewed interest in the radical perineal
prostatectomy. Because of exact operation-technique with permanent visual
control, generally less blood loss, small complication rates and a diminished
morbidity the perineal approach represents another example of "minimal invasive
surgery". There are an increasing number of patients with localized prostate
cancer in whom this is an appropriate treatment option.
PMID- 10692787
TI - [Current options in the treatment of urolithiasis].
AB - Until the 1980s, treatment of upper urinary tract often involved extensive
surgical procedures. With the introduction of the extracorporeal shock-wave
lithotripsy and refinements to endoscopic instruments and surgical techniques, it
has now become possible to destroy stones in most cases without open surgery.
Modern stone management can be divided into three steps. The first step covers
the treatment of acute pain and the drainage of an obstructed and possibly
infected kidney. The second step aims to either remove for destroy the stone. The
third step is directed towards the prophylaxis of stone recurrence.
PMID- 10692788
TI - [Sexual male dysfunction].
AB - Disorders of libido, erection orgasm and ejaculation are the most important
reasons for male sexual dysfunction (MSD), because of organic reasons, medical
therapies and social stressing factors, MSD is increasingly evaluated more
precisely and it is not limited on erectile dysfunction any longer. With the
appearance of the first oral acting substance on the market and the presence of
media a great pressure arose to the medical doctors to do prescriptions.
Therefore, it is very important to have consultation, diagnostics and treatment
of the MSD done with elaborated medical criteria.
PMID- 10692789
TI - [Arterial supply in the left colonic flexure].
AB - The authors study the behaviour of the middle colic, left colic superior, middle
and inferior and the first sigmoidal arteries in the territory of the terminal
portion of the transverse colon, the left colonic flexure and the descending
colon. The study was carried out on 1200 angiographies of the superior and
inferior mesenteric aa. and on 150 anatomical specimens, surgically extirpated in
the course of left emicolectomy operations. Contrary to what is believed by most
authors, the left flexure is a colonic tract very well supplied by blood while
the descending colon results to be poorly supplied, being served only by one
artery (the left sup. colic a.) often of limited caliber and with branches (the
middle and the inf. left colic aa.) sometimes totally or partially lacking. In
this last colonic tract the vascular continuity, represented by the arterial
arcades, is often interrupted. The Riolan's arcade, variously shaped, is to be
considered a constant vascular structure (only once it was lacking in this
study). Sometimes it is doubled by a second more internal arcade which must not
be confused with the intermesenteric arcade. In four of the observed cases, the
Riolan's arcade resulted strengthened by a second retroperitoneal arcade, derived
from a branching of the middle colic a., whose branches of division went to the
two colonic flexures and descended along the postero-lateral walls of the
ascending and descending colon, often parallel to the regular abdominal branches.
Exceptionally the colonic flexure is supplied by the only left colic a., which
behaves as a specific artery, by us called "dominant artery". The central
branches of the artery go to the flexure while the lateral ones join the branches
of the middle colic and the first sigmoidal aa., effecting tenuous connections,
surgically unreliable. In this case the arterial continuity of the Riolan's
arcade can be considered interrupted, at least for the surgical practice. The
intermesenteric arcade, in its three forms (direct, mixed and indirect), was
observed in 20% of the cases. The colic marginal a. is considered by the authors
a tier of arches formed by the colic aa. The left colonic flexure is also
supplied by particular vessels originated from the middle colic and the left
colic aa. (angular branches and arcades and bridge-branches) or from the superior
mesenteric a. (angular artery of Donati) and from other sources, particularly
from the splenic a. These vessels then join the colic "vasa recta" through the
phrenocolic ligament and the marginal omental vessels. This research shows that
the vascular continuity of the left colon is not a constant element, able to
reassure the surgeon, for possible interruptions that may occur in its
composition.
PMID- 10692790
TI - [Gynecomastia: diagnostic and surgical approach in the treatment of 61 patients].
AB - Gynaecomastia is a disease with a high incidence (approximately 65% of adult
males between 15 and 40 Ys.). In this paper the authors present their experience
about the medical and surgical treatment comparing different surgical techniques:
adenomammectomy, liposuction and liposuction associated with adenomammectomy. 61
patients ageing 17-42 Ys. (54 with bilateral gynaecomastia and 7 with monolateral
disease) were, treated in the Dept. of Plastic Surgery of the Niguarda Ca' Granda
Hospital in Milan from 1985 up to 1995. 26 patients were treated with
adenomammectomy; Suction assisted lipectomy was used alone in 4 cases and
associated with adenomammectomy in 34 cases. The authors suggest that the
associated method is the most effective, the aesthetic results being excellent
with an important reduction of post-operative complications (mostly referred as
haematoma, seroma).
PMID- 10692791
TI - [Acute biliary pancreatitis. Role of laparoscopy after 30 years of traditional
surgery experience].
AB - The authors herein show their own experience in the treatment of acute biliary
pancreatitis. Aim of this study is to evaluate the effectiveness and the safety
of the "early" laparoscopic approach to the mild to moderate acute biliary
pancreatitis. The authors studied sixty cases of laparoscopic cholecystectomy
with intraoperative colangiography for acute biliary pancreatitis (M/F 1:1.2;
mean age 59.6 yrs, range 29.79). The patients were divided in two groups on the
basis of the severity of the pancreatitis, defined through Ranson's score and
Balthazar classification. The mortality rate was nil. Intraoperative morbidity
rate was 6.6% in the group I (3/45), and 13.3% in the group II (2/15).
Postoperative morbidity rate was 6.7% (3/45) in the group I and 40% in the group
II (6/15). The authors show an original diagnostic and therapeutic algorithm for
the treatment of acute biliary pancreatitis. Early laparoscopic cholecystectomy
with I.O.C. is proposed as the gold standard treatment for mild to moderate acute
biliary pancreatitis. This approach appears to be effective and safe in their
experience. In case of severe acute biliary pancreatitis, further investigations
are mandatory to evaluate the role of laparoscopic approach.
PMID- 10692792
TI - [Role of curative local excision in rectal cancer].
AB - The aim of this retrospective study is to evaluate the results of local excision
(LE) for rectal cancer for curative purposes. From 1969 to December 1997, a total
of 456 operations were performed for surgical treatment of rectal carcinoma (262
males and 194 females, mean age 66 years). 20 patients (4.1%) underwent LE, 7
males and 13 females, median age 65 years. Patients were selected for LE if they
met the following criteria during preoperative staging: tumors staged as T1-T2,
N0, M0, grading G1 or G2, achievable location. As far as the type of LE is
concerned, 13 transanal excisions (Francillon technique), 2 Mason, 2 endoscopic
excisions and 3 TEM were performed. Among patients who underwent LE there was no
operative mortality. 13 tumors were T1 and 7 were T2; pathologic findings
included 20 adenocarcinoma, 14 G1 and 6 G2. There was no postoperative specific
morbidity, while aspecific morbidity was minimal (5%). There were no local
recurrences but 2 patients (10%) had secondary lesions. Five year overall
survival following LE was 87.4%. Comparing T1 and T2 tumors after APR and SSR (17
T1 and 42 T2, all adenocarcinoma), operative mortality and specific morbidity
were respectively 1.7% (p = 0.55) and 28% (p = 0.007). There were 5 (8.5%) local
recurrences (p = 0.17) and 6 (10.2%) metastatic lesions. Five year overall
survival was similar to LE (88.3%; p = 0.76). In conclusion the authors stress
the importance that IE for rectal carcinoma must be performed only in selected
patients provided there is correct preoperative staging. In these cases five year
overall survival, local recurrence and operative mortality were similar to APR
and SSR, while there was a statistically significative difference following LE in
terms of specific morbidity.
PMID- 10692793
TI - [Hernia repair with local anesthesia].
AB - The authors report the results of their own personal experience with inguinal and
femoral hernioplasties (424 cases) performed under loco-regional anaesthesia.
This anaesthetic approach together with the use of prosthetic techniques (tension
free and suture-less) represent the "Gold Standard" in the surgical treatment of
hernia. The absence of mortality, the remarkable reduction in terms of
postoperative complications, days of hospitalization (one day surgery) represent
outstanding advantages. The cooperation of the patient and the stress test at the
end of the operation are further advantages of the proposed technique.
PMID- 10692794
TI - [Retroperitoneal tumors].
AB - The retroperitoneal tumors are seldom met in their several histological
expressions. Authors totally considered 27 patients with retroperitoneal tumors
and they were observed from 1975 to 1996: 21 of them were primitively cured in
this Institute whereas 6 were affected with relapse or metastasis after a
surgical approach which had been performed by other structures. Their operability
resulted of 100% with an 87% resectability rate. The surgical mortality resulted
nil while the morbidity rate was of 44%. The global survival resulted of 60% to 5
years while the disease-free interval was of 35%. The outliving to 5 years
resulted of 65% with a 60% disease-free interval only in the patients who were
treated in first instance. The surgical therapy represents the only treatment
which can modify the clinical history of such neoplasms. Exeresis should be
aggressive enough in order to obtain a total extirpation of the mass and grant a
right margin of safety of sound tissue. Such radical proceeding should also be
pursued in the treatment of relapses and metastases. The therapeutical efficacy
is always linked to the precocity the diagnosis. A strict follow-up of the
patients who underwent a surgical operation for retroperitoneal neoplasm is
therefore necessary. A minority of the instances was only subjected to a
complementary radio and/or chemotherapic treatment. Such protections did not
significantly modify the outliving.
PMID- 10692795
TI - [Transclavicular approach for delivery of intrathoracic giant goiter. An
alternative surgical option].
AB - To remove the immerse portion of a cervical goitre it is necessary to treat
preventively the cervical thyroid arteries. In most cases it is afterwards it is
easy the blunt finger dissection of the mediastinal bulk following the correct
cleavage plane and its dislodging in the cervical area. But in very rare
instances, according also to the personal experience, remains some difficulty for
the passage of a too bulky and hard mediastinal mass through the rigid limits of
the upper thoracic outlet, or the immerse struma is too fragile for pulling it by
transfixion threads. Therefore, traditionally arises the opportunity of an
additional surgical access, through the breastbone or through the thoracic wall,
according to the circumstances. Our experience, completely occasional but
extremely positive of two of such cases, induces us to advance a proved
alternative surgical proposal. When the difficulty of the removal of the immerse
portion of the goitre comes only from the incongruence of the immerse volume and
the rigid limits of the upper thoracic outlet, our proposal is that to obtain an
amplification of the narrow passage breaking the continuity of the clavicle, by
its section beneath the periostium near the breastbone and removing this sternal
stump from the joint. The result is that of an widening of the upper thoracic
outlet, no more rigid, and making easy the transit of the immerse portion from
anterior mediastinum so dislodged in the neck. The rationale of this choice is
that all is requested in such cases is only to overcome the obstacle of the
incongruence among volume and bulk of the immerse portion and the bone limits
fixed from the narrow upper thoracic outlet. Both the traditional sternotomy and
the thoracotomy seems disproportional for this purpose, moreover with additional
problems during the operation. The true advantage of these classical solutions is
in treating under direct vision the anomalous arteries of the mediastinal goitre
in cases of ectopic localization. But this is not the case of an immerse cervical
goitre. It is therefore essential to note that this proposal applies only to the
migrated goitre and not to the ectopic ones. The recovery is extremely simple,
and both the aesthetics and the static of the scapular joint are not
substantially compromised.
PMID- 10692796
TI - [Autologous transfusion technique application table].
AB - The authors make a survey on the reasons leading to the application of different
methods of autologous transfusion. They underline, incidentally, the important
role played by the issues encountered in dealing with Jehovah's Witnesses as well
as the discovery and spread of new transfusion transmitted diseases like AIDS and
hepatitis C. They explain their experience, from which they have produced a Best
Autologous Transfusion Technique Application Table (Scheda di Applicazione
Ottimale delle Metodiche di Autotrasfusione, SAOMA), specific for every type, of
operation, through the analysis of many parameters (surgeon, anaesthetist,
transfusionist, general conditions of the patients, type of surgical operation).
Moreover the authors evaluate advantages and disadvantages of the different
autologous transfusion methods, including their cost efficiency aspects, and how
they can be combined depending on the type of surgical operation. As a conclusion
they attribute great importance to SAOMA to minimize homologous blood transfusion
risks, even though at times the clinical aspect is made to prevail over the
economic one.
PMID- 10692797
TI - [Splenic infarction caused by vascular pedicle torsion].
AB - We report a case of a spleen infarction caused by the vascular pedicle torsion. A
25 year-old-man, heterozygous for HbS, presented with severe abdominal pain
especially in the left upper quadrant in front and in the back, fever other
symptoms related to acute abdomen. First we excluded most common disease
(occlusive one and hematologic one) through conform investigation, then we
suspected a spleen problem. So we did further investigation with ultrasonography
which showed splenomegaly and the spleen looked twisted with its hilum in contact
with previous abdominal wall, moreover (here were are as of decreased signal
intensity characteristic of splenic infarction under the capsule and some blood
in the Douglas pouch. The patient underwent splenectomy urgently. During the
intervention we saw a splenomegaly like the ultrasonography showed, moreover
there were a long twisted vascular pedicle and many areas of infarctions, some of
which had ruptured causing emoperitoneum. The surgical intervention was
successful and the clinical spectrum was solved. The splenic infarction might be
clinically silent or to represent a surgical emergency. In front a case of acute
abdomen, after exclusion of most common etiology, we underline the importance to
suspect a spleen suffering, especially vascular one, when (here was no history of
trauma. Considering this fact, a simple not invasive examination like
ultrasonography is able to confirm this kind of hypothesis and to give soon
information to make the surgical choose.
PMID- 10692798
TI - [Obstructive jaundice caused by hydatid cyst rupture in main bile duct].
AB - Hydatid hepatic cyst rupture into bile duct is a complication of hydatid disease.
The rupture is more frequent in right or left epatic duct and occasionally in
common bile duct (7-9%). A 50-year old man came to emergency room owing to
jaundice, fever and abdominal pain. TC show an hydatid cyst with daughter's cyst
of left liver and dilatation of biliary tree. Laboratory data of significance
included an increased of liver function tests (Bilirubin, Alkaline ph., SGOT,
SGPT), VES and leukocytosis. The patients was surgically treated, by total
pericystectomy, colecystectomy and coledocotomy with lavage o common bile duct;
finally we placed one Kehr drainage and two abdominal drainage. After 15 days of
postoperative hospitalization patient was discharged. The best treatment of
hydatid cyst is total pericystectomy (when possible). An alternative surgical
treatment is possible for the presence of communication with biliary tree. ERCP
is very important for a correct diagnosis and for a complete surgical treatment.
PMID- 10692799
TI - [Gallbladder agenesis in the laparoscopic era: report of a case].
AB - The authors report an observed case and re-examine the incidence of this defect;
they underline the possibility of the diagnosis during the fetal age and the
association with one o more defects, sometimes incompatible with the life; in the
adult, on the contrary, may be evidence of an associated litiasic pathology of
the ++epato-choledocus or of the stenosis of the oddian sphincter. On the base of
the diagnostic previous experiences, they elaborate the proposal of an algorythm
and underline the utility of a laparoscopic diagnosis either in the pre-operative
doubious cases or in the intra-operative diagnosed cases.
PMID- 10692800
TI - Adenocarcinoma arising from a recurrent fistula-in-ano.
AB - Anal fistulas are frequent events which often recur after an inadequate surgical
treatment. Nevertheless their evolution into malignant diseases is infrequently
observed. The authors report one case of mucinous adenocarcinoma arising out of a
recurrent, long-lasting fistula-in-ano. As reported, abdomino-perineal resection
combined with radiotherapy can be the choice treatment. The difficulty is to
obtain a reliable differential diagnosis. No imaging technique nor histologic
examination can establish a definitive reliable diagnosis; nevertheless, as the
risk of adenocarcinoma developing from a long-lasting recurrent fistula-in-ano,
although small, is real, authors believe that operative exploration and biopsy of
recurrent abscesses and fistulas should be recommended.
PMID- 10692801
TI - Recruitment and retention of African American elders into community-based
research: lessons learned.
AB - Factors influencing the recruitment and retention of African Americans into
research studies are not well understood. Studies show that their numbers
continue to be low in clinical trials and other nursing studies. However, African
Americans have disproportionately high incidences of disease, illness, and death,
an important reason for their inclusion in ongoing research. Two urban, community
based intervention studies with elderly African American participants are used to
show different issues and strategies in recruitment and retention. The sample
selection and attrition experiences in the studies are examined using 3
theoretical approaches. Six concepts emerge as fundamental to successful
recruitment and retention of diverse population groups: (1) historical
cognizance; (2) sanctioning; (3) trust-building; (4) mutuality; (5) recognition
of heterogeneity; and (6) researcher self-reflection and introspection.
PMID- 10692802
TI - Being a case manager for persons with borderline personality disorder:
perspectives of community mental health center clinicians.
AB - The scope of case management has expanded to include persons with chronic,
nonpsychotic disorders, in particular, persons diagnosed with borderline
personality disorder. Despite more widespread use, literature about case
management for persons with this disorder is limited. To address this gap in
knowledge, a study of the day-to-day experiences of case managers who care for
persons with borderline personality disorder was conducted. Seventeen community
mental health center case managers gave their informed consent to participate in
individual, in-depth interviews. The interviews were analyzed using an
interpretive phenomenological research approach. The analysis showed a pattern of
monitoring self-involvement. The case managers monitored themselves in terms of
expressing concern and setting boundaries. These shared practices highlight a
central and unique component of being a case manager for persons with borderline
personality disorder, that is, the case manager's focus of attention is on self.
By focusing on the self, case managers seek to retain control of the nature of
the relationship. The author asserts that the matter to be resolved is not to
determine whether retaining or relinquishing control is better, but rather, how
best to help practitioners maintain a helpful relationship over time with persons
who have borderline personality disorder. In an effort to accomplish this goal,
questions about current helping practices and suggestions for working
collaboratively with persons who have this diagnosis are provided.
PMID- 10692803
TI - Psychological distress in non-Hispanic white and Hispanic abused women.
AB - Despite the increasing number of studies that have substantiated that women who
have been abused are psychologically distressed, existing research has little
focus on women from diverse ethnic backgrounds, and variables that may influence
the development of psychological distress have yet to be examined. This study was
conducted to examine the correlation of psychological distress with abuse and
psychosocial factors in a sample of 62 White and 62 Hispanic abused women. A set
of measures of posttraumatic stress disorder, depression, and anxiety showed that
White women experienced a higher prevalence of psychological distress than
Hispanics. Life changes significantly related to the severity of psychological
distress, whereas exposure to abuse was not consistently associated with it.
Implications for practice and research are discussed.
PMID- 10692804
TI - Arriving at readiness to recover emotionally after sexual assault.
AB - The purpose of this grounded theory study was to discover behaviors and processes
that lead survivors of sexual assault to seek help with emotional recovery. The
substantive theory Arriving at Readiness was developed from interviews with 11
women survivors of sexual assault. Eleven categories, each containing several
strategies, form the theory. The core variable is arriving at readiness. The
findings clarify why survivors often delay obtaining help with emotional
recovery. The theory can be used as a tool to make it more likely survivors will
be identified and receive help that is responsive to their needs.
PMID- 10692805
TI - Evaluating the effectiveness of progressive muscle relaxation in reducing the
aggressive behaviors of mentally handicapped patients.
AB - This article reports the results of a study on the evaluation of the
effectiveness of muscle relaxation training in reducing aggressive behavior in
mentally handicapped patients (MHPs). A pretest and posttest study design was
used. Findings showed that there was a reduction of 14.7% of aggressive behavior
in the subjects after the muscle relaxation training. Muscle relaxation training
appeared to be effective in reducing the frequency of some aggressive behaviors.
The strengths and limitations of using muscle relaxation training in reducing
aggressive behaviors are discussed.
PMID- 10692806
TI - [Cervix cancer and pregnancy. Experience of 5 years at the Gynecology-Obstetrics
Hospital No. 3, C. M. La Raza from the Mexican Institute of Social Security].
AB - Of the 300 clinical files of pregnant women, 22 were associated with cancer plus
pregnancy in 5 years. Of them 7 were excluded in the work. 15 patients with CaCu
and pregnancy were studied in the Gineco-Obstetric Hospital No. 3 C.M. La Raza of
the IMSS Mexico City in a period since 1st of January 1988 to 31st December of
1992. Early menarchia and sexual life, take an important roll in the mexican
women as predisponent factors, multideliver and tobacco too. The colposcopy with
manage cervix biopsy is the election method of diagnosis, with 99.5% of
confiability. In the 15 patients, the estirpe was epidermoid cancer in all of
them. The diagnosis of pregnancy age made in the first and third trimester of
gestation. Only in 3 patients (20%) were founded visible lesion, this rename the
necessity of make detection of CaCu during the pregnancy, because we will can
found the cases in preinvader stages or early invader, that cure highly, like the
cases seen in this work. Stages preinvader and early invaders during the
pregnancy are highly curatives. We concluded that they have worst prognosis of
survival, aggressivity and early relapse in patients with pregnancy stage by
stage. The last because in the Historical Literature review about this topic,
there was statistical relevance about pregnancy in the women with CaCu, using our
work for reference. CaCu does change his prognosis associated with the pregnancy.
PMID- 10692807
TI - [Epidemiology of preeclampsia-eclampsia at the General Hospital O'Horan.
(Epidemiology of preeclampsia-eclampsia of a sample, in Yucatan)].
AB - The objective was to describe the epidemiology of preeclampsia-eclampsia (P-E) at
the Hospital General O'Horan (HGOH) in Merida, Yucatan, Mexico, from 1995 to
1998. Patients with a discharge diagnosis of P-E were included. Their demographic
and clinical data were ascertained. To analyze information, descriptive
statistics were used. There were 143 patients. Preeclampsia was documented in 41%
and eclampsia in 59%. The mean age of the group was 24.4 +/- 7.3 years. It was
found that 76% came from rural area. In 79% schooling was no more than elementary
education. Seventy five per cent were married. Sexual life began at a mean age of
18.8 +/- 4.3 years. There was no prenatal care in 27% of the cases. Fifty five
per cent were primigravida and 43% multigravida. Nuliparity was documented in
52%. Two o more parities were documented in 48%. Complications were seen in 30%.
Overall mortality rate was 5%, more frequent eclamptic patients. At the HGOH, P-E
was frequently documented in women with both low socioeconomic status and fewer
years of schooling. Prenatal care was also irregular. Clinical evolution was
satisfactory in most of them, and the mortality rate was low, although it usually
occurred in young eclamptic women.
PMID- 10692808
TI - [Trends of perinatal mortality at the National Institute of Perinatology].
AB - The purpose of this study is to address the yearly fetal, neonatal, crude death
rates observed at the Instituto Nacional de Perinatologia from 1987 through 1997,
and the specific death rates for birth weight, gestation age, cause of death,
avoidability, and structure and process failures as proxy to quality of medical
care. Data come from death certificates following the WHO criteria which includes
the maternal medical history, pregnancy follow up, birth attendance, newborn
characteristics, autopsy findings, microbiological results, basic cause of death
(of both maternal and fetal/neonatal origin), death avoidability, and structure
and process issues. The death certificates were analyzed by the Perinatal
Mortality Committee and registered into a computerized database. The fetal
mortality rate during 1987 was 17.67 per 1000 births, whereas in 1997 it was 21.5
per 1000 births. There was an increasing tendency from 1987 to 1992, with the
highest rate being 34.13 during 1992. After 1992 this rate shows a decreasing
tendency. The neonatal mortality rate decreased from 42.82 in 1987 to 17.34 per
1000 live births in 1997. The highest rates were observed among the newborns with
the lowest birth weights and at the youngest gestational ages. The most frequent
cause of death of maternal origin, in both fetal and neonatal deaths, was
premature rupture of membranes. As for the most frequent fetal cause of death was
antepartum hypoxia, and among neonatal deaths prematurity and immaturity. The
percentage of avoidable perinatal deaths has declined dramatically from 27% in
1987 to less than 10% in 1996. Perinatal mortality at the Instituto Nacional de
Perinatologia has decreased during the period under assessment, due to the
reduction of the neonatal mortality rate. Improving the quality of medical care
focusing mainly on process issues will help lowering avoidable mortality rates.
PMID- 10692809
TI - [Bilateral renal agenesis (Potter's syndrome) in a girl born to a hyperthyroid
mother who received methimazole in early pregnancy].
AB - Bilateral kidney agenesias (Potter syndrome) in a newborn of a hyperthyroid woman
receiving methimazole during early pregnancy. This is a clinical case of a
hyperthyroid woman that received methimazole during early pregnancy who gave
birth to a girl with bilateral kidney agenesis. The initial clinical data was the
presence of oligohydramnios detected by an ultrasound (US) at 19 gestational
weeks. Another US at the term of the gestation showed anhydramnios, absence of
renal silhouettes and bladder, which was corroborated when the girl was born. She
died two days after she was born. Sufficient evidence exists that the methimazole
administered during the early pregnancy can cause diverse congenital
malformations including Potter's syndrome.
PMID- 10692810
TI - [Excretion of uric aid, sodium, and potassium in preeclampsia patients and its
behavior in acute hyperglycemia-hyperinsulinemia].
AB - The aim of the present research was to compare the uric acid, sodium and
potassium excretions among patients with mild preeclampsia and normotensive
pregnancy and to determine their behavior towards an acute physiologic state of
hyperglycemia-hyperinsulinemia. It was carried out a cuasi-experimental study
with parallel group in 25 patients with mild preeclampsia and in 25 patients with
normotensive pregnancy all of them in the third trimester of gestation. The
intervention consisted in administering an oral load of 50 grams of glucose in
order to achieve a physiologic state of hyperglycemia-hyperinsulinemia. The seric
levels of glucose, insulin, creatine, uric acid, sodium and potassium were
measured, as well as the last four in urine before the oral load (with at least 6
hours fasting) and 60 minutes after the load, besides that, the urinary
excretions of solutes were calculated with standard formulas. The urinary
excretions of uric acid, sodium and potassium in fasting, and so after the oral
glucose load were lower in the group of preeclampsia patients than in the
normotensive gestation group. Upon analyzing the influence of a physiologic state
of hyperglycemia-hyperinsulinemia, after the oral glucose load on determined
solutes and their urinary excretion, we found that there was a significant
decrease in the seric potassium level, without modifying its urinary excretion,
as much as in the preeclampsia group as in the normotensive group. The seric uric
acid and sodium levels diminished in the preeclampsia group and in normotensive
group respectively, without modifying their urinary excretion. In conclusion, in
the current study the urinary excretion of sodium, potassium and uric acid were
lower in the preeclampsia patients than the women with normotensive pregnancy and
a physiologic state of hyperglycemia-hyperinsulinemia didn't modify these
excretions.
PMID- 10692811
TI - Ozone exposure: a case report and discussion.
AB - A 45-year-old man working with ozone presents with evidence of sinusitis, mucus
membrane irritation, sleep disturbance and shortness of breath. Naturally
occurring or manmade, ozone may damage pulmonary alveolar type I cells at
significant exposure levels. EPA and OSHA regulate exposure concentrations.
Studies show dose responses with exposures. Supporting epidemiological studies
are reviewed briefly. Limiting potential for excess exposure is key to
prevention. Recognition of ozone as a potential exposure in the Oklahoma
workplace is key to symptom management.
PMID- 10692813
TI - A curriculum for stimulating the moral imagination.
PMID- 10692812
TI - Improving the health of Oklahomans through clinical prevention. Part 1:
Counseling to decrease major risk factors.
AB - Compared to other states, Oklahomans suffer higher levels of morbidity and
mortality from several common conditions--coronary heart disease, chronic lung
disease, stroke and injury. Unhealthy personal behaviors contribute significantly
to each of these conditions, thus rendering them at least partially preventable
by changing those behaviors. Research has shown that many patients will modify
unhealthy behaviors as a result of services provided by physicians or staff in
their offices, often with briefly delivered messages. In this report we will
discuss the most common preventable illnesses suffered by Oklahomans and the risk
factors associated with those illnesses. Physicians should make maximum use of
their ability to promote healthy behaviors by their patients, with emphasis on
the risk factors associated with significant morbidity in the state. They should
also focus on those risk factors patients are likely to change following
physician counseling, as determined by prevention research and described in the
U.S. Preventive Services Task Force document Guide to Clinical Preventive
Services. In general, physicians should consistently deliver messages that
address tobacco products, alcohol and other drugs, the use of seat belts, and
diet and exercise. Also, they should recommend that all women of childbearing age
who are capable of becoming pregnant take a multivitamin containing folic acid
daily.
PMID- 10692814
TI - AMA litigation center pushes for physician rights.
PMID- 10692815
TI - The economy of medical knowledge.
PMID- 10692816
TI - Palmoplantar keratoderma (Voerner) with composite keratohyalin granules: studies
on keratinization parameters and ultrastructures.
AB - A case of the Voerner type palmoplantar keratoderma was studied for abnormalities
of keratinization parameters. An enzyme and materials used to build the marginal
band or cellular envelope of the cornified cell were all abnormally expressed;
i.e. transglutaminase I (TGK), loricrin, and involucrin were abnormally
immunostained. In the normal controls, their expression was limited to the upper
epidermis, mainly in the granular layer. In the lesional skin, they were detected
from the suprabasal layer to the lower horny layer. Filaggrin, the protein of the
keratohyalin granule, was also expressed more widely than in controls.
Ultrastructural abnormalities included a significantly higher frequency of
composite keratohyalin granules than controls, early formation of a marginal band
in the midepidermis, and, most remarkably, the clumping of tonofilaments causing
vacuolization of the cytoplasm of affected keratinocytes.
PMID- 10692817
TI - Repeated 5-aminolevulinic acid-based photodynamic therapy following electro
curettage for pigmented basal cell carcinoma.
AB - 5-Aminolevulinic acid-based photodynamic therapy (ALA-PDT) in the standard manner
is ineffective for pigmented basal cell carcinoma (pBCC), because melanin absorbs
the photoactivating light interred for protoporphyrin IX. The objective of this
study was to assess the therapeutic outcome of pBCCs with repeated ALA-PDT
following removal of pigmentation with electro-curettage. After electro
curettage, 16 pBCCs were treated with a combination of topical application of 20%
ALA in O/W emulsion and topical instillation of 10% ALA solution, followed by
photoactivating light. ALA-PDT was performed more than three times. Fourteen of
16 pBCCs showed CR. Two pBCCs showing PR or NR were excised. Repeated ALA-PDT
following electro-curettage was effective for pBCC.
PMID- 10692818
TI - Giant nevus lipomatosus cutaneus superficials: case report and review of the
literature.
AB - Nevus lipomatosus superficialis is a rare disorder characterized by a nevoid
fatty growth within the papillary and reticular dermis. Lesions more often occur
in the sacral, abdominal, or pelvic regions. A 36-year-old Brazilian female with
giant nevus lipomatosus is reported. Our case seems to be the biggest reported in
the literature.
PMID- 10692819
TI - A case of actinic prurigo in Thailand.
AB - Actinic prurigo is a separate entity from the polymorphous light eruption that
affects American Indians. It has been reported mainly from North and South
America, with only few reported cases from Britain or Asia. We report a case of
actinic prurigo in a Thai girl who showed cheilitis and pruritic papules on
exposed areas for three years. We were able to induce populovesicular lesions by
three consecutive irradiations with 100 J/cm2 UVA and 2 minimal erythematous dose
of UVB. However, three weeks after irradiation, a prurigo papule developed at the
UVB irradiated site.
PMID- 10692820
TI - Trichotillomania and trichophagia leading to trichobezoar.
AB - A 14-year-old female presented with the complaints of loss of hair, scalp
pruritus, and pain in the abdomen. On careful work-up, she was found to have
trichotillomania as well as trichophagia. Investigations also revealed a
trichobezoar which completely filled the stomach. Hemogram showed moderate
hypochromic anemia. Her detailed psychiatric profile showed a few additional
features like obsessive hand washing, knuckle cracking, nose picking and body
rocking. Her trichobezoar was removed surgically, and she had an uneventful post
operative recovery. She is being maintained on fluoxetine and is doing well. The
role of a multi-disciplinary approach to trichotillomania patients is
highlighted.
PMID- 10692821
TI - Angiolymphoid hyperplasia with eosinophilia showing characteristics of Kimura's
disease.
AB - Angiolymphoid hyperplasia with eosinophilia (ALHE) is a rare benign condition
affecting principally the head and neck region of young females. We describe a 42
year-old female patient of ALHE showing the typical changes of endothelial cells
and features similar to Kimura's disease in histologic and immunohistochemical
findings.
PMID- 10692822
TI - A case of linear scleroderma and myasthenia gravis.
AB - We report a case of a 28-year-old woman with myasthenia gravis who developed
linear scleroderma seven years later. Myasthenia gravis and scleroderma are
rarely found in direct association with each other; there are only five such
reported cases, all of which were systemic scleroderma patients. Although
localized and systemic scleroderma are distinct entities, autoimmunity is
believed to be involved in the pathogenesis of both. Myasthenia gravis and
scleroderma may occur coincidentally, but an autoimmune predisposition seems to
be the more likely underlying cause, as evidenced by an increased incidence of
autoantibodies and autoimmune diseases.
PMID- 10692823
TI - Subcutaneous cysticercosis involving the eyelid: sonographic diagnosis.
AB - A 25-year-old man and a 14-year-old boy presented with neurocutaneous
cysticercosis involving the eyelid. Both patients had hundreds of scattered
subcutaneous cysticerci. They were arranged in clusters over the
sternocleidomastoid muscle in the neck. Such clustering of cysticerci is highly
suggestive of central nervous system (CNS) involvement, as both the
sternocleidomastoid muscle and the CNS are supplied by the carotid artery and
cysticerci travel via the hematogenous route. We used ultrasonography to diagnose
subcutaneous cysticercosis, which showed characteristic low reflective cysts and
high reflective scolices inside. Although subcutaneous cysticerci are
inconsequential, their verification is important in the diagnosis of more severe
CNS involvement. They may be confused with other painless swellings such as
lymphadenopathies, neurofibromas, and epidermoid cysts.
PMID- 10692824
TI - Large annular purpura and paraneoplastic purpura in a patient with Sjogren's
syndrome and cervical cancer.
AB - We report a 79-year-old female with anaphylactoid purpura on her legs and unusual
large annular purpura on the trunk. Histopathological characteristics of
leukocytoclastic vasculitis were observed in the upper and middle dermis of both
types of skin lesions. She was complicated by Sjogren's syndrome and advanced
cervical cancer. The annular purpura spontaneously resolved in a week and did not
recur. However, the anaphylactoid purpura relapsed more frequently and spread
more widely following the elevation of her serum SCC antigen levels from the
onset of purpura until her death. We consider that the characteristic annular
configuration was caused by the complication of Sjogren's syndrome and that the
recurrent anaphylactoid purpura indicated paraneoplastic vasculitis primarily
caused by the tumor specific protein immune complexes. Complication by Sjogren's
syndrome many also play a role in the development of allergic vasculitis.
PMID- 10692825
TI - Difficulties in treating steroid withdrawal: intermittent ACTH and low dose
systemic cyclosporin used to treat a senile erythroderma patient.
AB - The tapering or termination of prolonged strong topical and/or systemic
corticosteroid application for extensive generalized eczema has adverse effects
on the body and thus presents a very difficult situation. The present case is
that of a 68-year-old man with erythroderma following eczema, whose steroid
withdrawal was successfully treated with intermittent ACTH and low dose systemic
cyclosporin administration over a period of one year.
PMID- 10692826
TI - Pityrosporum folliculitis: renal transplantation case report.
AB - Pityrosporum folliculitis is caused by the fungus Pityrosporum ovale. It is
characterized by the presence of pruriginous follicular papulae and papulae
pustules in face, upper part of the trunk, and upper limb root. It is more
prevailing in places with hot and humid climates. Its incidence can be associated
with either immunosuppressive or chemotherapy states secondary to pathologies. We
report herewith a case of pityrosporum folliculitis in a patient who had
previously underwent kidney transplantation and these result of the itraconazol
therapeutics given.
PMID- 10692828
TI - Acquired vulvar smooth muscle hamartoma: a case report and review of the
literature.
AB - A 36-year-old Korean woman had had a flesh-colored, indurated plaque with
pruritus on the labium majora for five years. The lesion was not found in
association with hyperpigmented or hypertrichotic patches. Results of biopsy
specimens showed an excess of haphazardly oriented smooth-muscle bundles in the
mid to lower dermis with an unremarkable overlying epidermis. Our diagnosis was
an acquired smooth-muscle hamartoma in the vulva. Although there have been
previously reported cases of acquired smooth-muscle hamartoma, this was the first
reported case in the vulva. We also describe the characteristics differing
between our case and the six previously reported ones.
PMID- 10692827
TI - Malignant hidroacanthoma simplex: a case report.
AB - Hidroacanthoma simplex is a benign tumor of the skin originating from or showing
differentiation to the sweat glands. It grossly resembles seborrheic keratosis of
Bowen's disease and histologically shows intraepidermal focal growth of
epithelial cells. Malignant transformation of this tumor is rare. We report a
case of pigmented hidroacanthoma with malignant transformation in a 67-year-old
woman. There was a 20-year history of a skin lesion on the right thigh, which
first appeared as a small verrucous papule, progressed to a dark-brown colored
patch, and then to a pigmented plaque. Histologically, the primary tumor was
composed of small squamoid cells with marked cellular atypia. Most of the tumor
cells were located in the epidermis. Immunohistochemically, the cytoplasm of some
tumor cells showed a positive reaction for epithelial membrane antigen, but not
for either carcino-embryonic antigen or the S-100 protein.
PMID- 10692829
TI - Cultured Paget cells derived from the involved skin of a patient with
extramammary Paget's disease had an extended life span.
PMID- 10692830
TI - Melasma in men: a hormonal profile.
AB - Melasma in men is much less common than in women. In the present communication,
we evaluated circulating levels of LH, FSH, and testosterone in 15 men with
idiopathic melasma. When compared with eleven age matched control men, the
circulating LH was significantly higher and testosterone was markedly low in the
melasmic men. We conclude that male melasma involves subtle testicular
resistance.
PMID- 10692831
TI - Antipruritic effect of macrolide antibiotics.
PMID- 10692832
TI - Molluscum contagiosum appearing as a solitary lesion on the eyelid.
PMID- 10692833
TI - Clinical findings in Japanese children with obstructive sleep apnea syndrome:
focus on dental findings.
AB - We evaluated clinical findings including those on dentistry and in the oral
cavity of children with obstructive sleep apnea syndrome (OSA). This study
examined twenty-seven OSA children, who were advised by otolaryngologists to be
admitted for closer examination and showed an apnea index (AI) of 5 or more on
polysomnographs. Their clinical history was obtained from their mothers, and oral
findings were also evaluated. The patient consisted of 15 males (56%) and 12
females (44%). The mean body mass index (BMI) was 16.0 +/- 3.0. Of the clinical
findings related to sleeping and the duration of sleeping, snoring was the most
frequently observed finding (100%). The mean duration of sleep, calculated from
the time they went to bed (9.2 +/- 0.8 p.m.) and the time they got up (7.1 +/-
0.8 a.m.), was 9.9 +/- 1.0 hours. Of the clinical findings obtained during the
daytime, hyponasal speech was the most frequently observed finding (74%). In
terms of dentistry, oral breathing was the most frequently observed finding
(89%). The mean duration of meals was 31.7 +/- 13.8 minutes. Results of oral
examination revealed that Hellman's dental age was most frequently IIA. According
to the standardized grading classification, grade I was observed in 7%, II in
63%, and grade III in 30% of subjects.
PMID- 10692834
TI - Role of T cell subset on the immunosuppression induced by Actinobacillus
actinomycetemcomitans.
AB - Purified splenic T cells from C3H/HeN mice primed with sonic extract (SE) from
Actinobacillus actinomycetemcomitans were adoptively transferred to syngeneic
mice with sheep red blood cell (SRBC). The transfer of splenic T cells from mice,
primed with SE for 8 days, resulted in the dose-dependent inhibition of IgM anti
SRBC plaque forming cells (PFC) compared with normal and BSA-primed splenic T
cells. Furthermore, the transfer of cells from mice primed with 200 micrograms of
SE for 8 days to syngeneic mice caused the highest inhibition. Immunosuppression
did not depend on the B cell population in spleen from donor mice primed with SE.
Splenic T cells from SE-treated mice could suppress the T cell-dependent
proliferative responses of co-cultured normal spleen cells in vitro. Analysis of
T cell subsets of spleen cells from mice treated with immunosuppressive factor
(ISF) showed that the suppressor cell is susceptible to treatment with anti-CD8
and complement (C). SE-sensitized suppressor T cells also suppressed the
secondary IgG anti-SRBC-PFC response after immunization with SRBC in vivo
depending on sensitized periods induced by ISF. Treatment of T cells from mice
which primed with ISF for 8 days, with goat anti-mouse CD8 antibody and C
abrogated their suppressive effects, and secondary IgG response occurred. These
results indicate that the adoptive transfer of SE-induced T cells, which
increased suppressor function, caused the perfect blocking of the immunoresponse,
allowing promotion of secondary infection.
PMID- 10692835
TI - Characteristics of proportional analysis for soft tissue facial profile:
epidemiological possibilities of measurement item reduction.
AB - Lundstrom et al. proposed a proportional analysis system for the soft tissue
facial profile in the natural head position. To use this method for further
epidemiological investigation and to interpret the characteristics of this
analysis, each measurement (index) was identified in comparison to the other
indices using cluster and factor analyses. Facial profiles of 111 (mean age: 22.9
years) Japanese males were measured and 11 indices (8 horizontal, 2 vertical and
1 horizontal/vertical) were calculated. Almost all internal co-relationships
between each index were statistically significant (p < 0.05, 0.01). Variable
cluster analysis classified indices into four major clusters and clarified the
attributes of the 11 indices. The first cluster was index No. 1, 2, 3 and 7. The
second cluster was index No. 6. The 3rd cluster was index No. 4, 5, 11, 8 and 10.
The 4th cluster was index No. 9. These clusters are thought as vertical facial
balance, upper and lower jaw relation or horizontal/vertical balance, chin
morphology, and horizontal facial balance. From factor analysis, three factor
axes that explained the characteristics of 11 indices were found (accumulated
contribution rate: 76.5%). The heaviest loading factor was index No. 1,2 (0.95)
on axis I, 5 (0.83) on axis II and 6 (0.78) on axis III. Therefore, axis I, axis
II and axis III are thought to be based on the position of the soft tissue
Nasion, SLI and Pogonion, respectively. Common indices which are included in both
analyses are thought to be valid as a clue to reduce the number of measurement
parameters.
PMID- 10692836
TI - Co-aggregation as a virulent factor of Streptococcus sanguis isolated from
infective endocarditis.
AB - The pathogenicity of strains of the Streptococcus sanguis group, isolated from
infective endcarditis, was studied by measuring the development of subcutaneous
abscesses in mice after infection with S. sanguis and Actinomyces viscosus either
singly or as co-aggregated pairs. The pathogenicity of the co-aggregates was also
examined in various viable combinations of the two bacterial species. More
abscesses were formed by A. viscosus than the S. sanguis group including clinical
isolates. Abscess formation by co-aggregates of combinations of each isolate and
A. viscosus produced a higher percentage of abscess formation than those caused
by infection with a pure suspension of A. viscosus or tested streptococci. Co
aggregated cells were more resistant to phagocytosis and killing by neutrophils
in vivo. These results indicated that S. sanguis group streptococci isolated from
infective endocarditis are able to co-aggregate and resist phagocytosis. The
ability of co-aggregation of S. sanguis may serve as a survival mechanism in a
host defense system and may be linked with virulence of this bacteria.
PMID- 10692837
TI - Mandibular-position sensation during sedation by administration of nitrous-oxide
(N2O) gas.
AB - Our aim was to confirm the influence of N2O gas on mandibular-position sensation.
The subjects in this study were eight healthy adults. Each subject was asked to
hold the reference stick for five seconds between the central tooth in his or her
upper and lower jaws. Then, the reference stick was replaced by the test sticks
with different thickness, each of which the subjects were again asked to hold at
the same position for five seconds. The subjects were instructed to determine,
based on judgement of the interincisal distance, whether the thickness of each
test stick was larger or smaller than the reference stick. A series of trials was
administered to each subject using all eight sizes of test sticks. We compared
the ability of the subjects to discriminate mandibular position both before and
after the application of a vibrating stimulus to the masticatory muscles, and
before and during the administration of N2O gas. Discrimination ability was
significantly decreased after the application of the vibrating stimulus. However,
during the administration of N2O gas, no significant difference in discrimination
ability was observed between before and after the vibrating stimulus. The results
of this study indicated that N2O gas had an inhibitory effect on gamma-motor
neuron activity, which is presumed to be mediated to some extent through the
higher central nervous system. This is the case because the gamma-motor neurons
are generally activated by vibrating stimuli applied to the muscle causing
decreased discrimination ability of mandibular position. Thus, we conclude that
mandibular-position sensation was influenced by N2O gas during the administration
of N2O gas.
PMID- 10692838
TI - A case of an electrical burn in the oral cavity of an adult.
AB - Electrical burns in the oral cavity account for 2.2% of all electrical burns and
only 0.12% of all burns; thus, the incidence of electrical burns in the oral
cavity is relatively low. As this type of injury occurs in the oral cavity when
an individual sucks or chews on a live electrical wire, extension cord, plug, or
outlet, most cases occur in toddlers or preschool children, and adult cases are
extremely rare. Here we describe a case of an electrical burn in a 56-year-old
man who accidentally bit the electric wire of a cleaner while carrying out
repairs. Conservative treatment, without surgery, was performed. Two years after
the injury, a slight scar and a small tongue deformity remain, but no functional
disturbance has been observed.
PMID- 10692839
TI - Oral collision carcinoma: salivary duct carcinoma of minor salivary gland origin
and squamous cell carcinoma of the oral mucosa.
AB - This paper reports a case of oral collision carcinoma consisting of salivary duct
carcinoma of minor salivary gland origin and microinvasive squamous cell
carcinoma of the oral mucosa in a 65-year-old Japanese man. This is an
exceedingly rare example of collision carcinoma in the oral region.
PMID- 10692840
TI - Worsening of pre-existing TMJ dysfunction following sagittal split osteotomy: a
study of three cases.
AB - When patients seeking treatment for malocclusion also suffer from
temporomandibular joint (TMJ) disorders, it is hard to predict the result of
simultaneous treatment of both conditions, or to plan for its different goals,
because of unpredictable changes in the relationship between the disk, the fossa
and the condylar head. Prediction is harder in cases of presurgical TMJ
hypomobility, especially those with adhesion in the upper TMJ compartment.
Authors differ widely on the likely effect of orthognathic surgery on TMJ
disorders. This paper reports three cases in which TMJ disorders worsened after
treatment of malocclusion by sagittal split osteotomy. It examines how
presurgical diagnosis of TMJ disorders could assist treatment planning in such
cases. The results suggest that microbleeding in the upper TMJ compartment during
orthognathic surgery, as well as long-term postoperative intermaxillary fixation,
carries a risk of creating worse adhesion that adversely affects the outcome for
patients. Therefore, preoperative diagnosis of disk position and pathological
conditions in the upper TMJ compartment, as well as careful choice of method and
term of postoperative fixation, are essential in planning the treatment of
malocclusion with sagittal split osteotomy.
PMID- 10692841
TI - Control of early ovarian follicular development.
AB - Early follicular growth refers to the development of an ovarian follicle from the
primordial to early antral phase. In sheep and cows these phases of growth can be
classified by the configuration of granulosal cells in the largest cross-section
of the follicle as types 1 (primordial), 1a (transitory) 2 (primary), 3 and 4
(preantral) and 5 (early antral). Follicles classified as type 1 may be highly
variable within each species with respect to number of granulosal cells and
diameter of oocyte. Much of the variation in granulosal cell composition of type
1 follicles may occur at formation and this may account for the variability in
granulosal cell composition throughout subsequent stages of growth. There appear
to be important differences among species (for example sheep and cattle) in the
number and function of granulosal cells relative to the diameter of the oocyte
during the initiation of follicular growth. There is evidence that most, if not
all, of the growth phases from types 1 to 5 are gonadotrophin-independent and
that follicles develop in a hierarchical manner. In sheep, cows and pigs,
numerous growth factor, growth factor receptor and gonadotrophin receptor mRNAs
and peptides (for example c-kit, stem cell factor, GDF-9, beta B and beta A
activin/inhibin subunit, alpha inhibin subunit, follistatin, FGF-2, EGF, EGF-R,
TGF beta 1,2 and 3 FSH-R and LH-R) are expressed in a phase of growth (for
example types 1-5)-specific and cell-specific manner. However, the roles of many
of these factors remain to be determined.
PMID- 10692842
TI - Comparative patterns of follicle development and selection in ruminants.
AB - Expanding technological capabilities, particularly in ultrasonography and
molecular endocrinology, have bridged the gap between form and function of the
ovary, and have been a catalyst for intense research activity in this area during
the last decade. However, the study of follicular dynamics is still in its
infancy in ruminant species other than cattle, and controversy persists regarding
the pattern of follicular growth and the existence of follicular dominance. The
bovine model of ovarian function is presented as a foundation for concepts
surrounding the control of follicular development in ruminants, and to place in
context the results of recent studies in sheep, goats, muskoxen, cervids and
camelids. This comparative approach is used to determine important generalities
that appear to be applicable, as fundamental physiological phenomena, to all
ruminant species. Although clear differences in follicular dynamics are evident,
differences appear to be specific rather than general, and the following
conclusions are consistent with results reported in ruminant species to date: (1)
follicles grow in a wave-like fashion; (2) periodic surges in circulating FSH are
associated with follicular wave emergence; (3) selection of a dominant follicle
involves a decline in FSH and acquisition of LH responsiveness; (4) periodic
anovulatory follicular waves continue to emerge until occurrence of an LH surge
(that is, at the time of luteolysis during the ovulatory season or during
transition from the anovulatory season); (5) within species, there is a positive
relationship between the duration of the oestrous cycle and the number of
follicular waves; (6) progesterone suppresses LH secretion and growth of the
dominant follicle; (7) the duration of the interwave interval is a function of
follicular dominance, and is negatively correlated with circulating FSH; (8)
follicular dominance in all species is more pronounced during the first and last
follicular waves of the oestrous cycle; and (9) pregnancy, the prepubertal period
and seasonal anoestrus are characterized by regular, periodic surges in FSH and
emergence of anovulatory follicular waves.
PMID- 10692843
TI - Molecular mechanisms regulating follicular recruitment and selection.
AB - Ovarian follicular growth and development is an integrated process encompassing
both extraovarian signals, such as gonadotrophins and metabolic hormones, and
intraovarian factors. Follicular development has been classified into
gonadotrophin-independent and -dependent phases. In the latter, FSH provides the
primary drive for follicular recruitment and LH is required for continued
development of follicles to the preovulatory stage. A transient increase in
circulating FSH precedes the recruitment of a group of follicles, and these
recruited follicles are characterized by expression of mRNAs encoding P450scc and
P450arom in granulosal cells. As follicles mature, there is a transfer of
dependency from FSH to LH, which may be part of the mechanism(s) involved in
selection of follicles for continued growth. Indeed, changes in the pattern of
expression of mRNA for gonadotrophin receptors and steroid enzymes within
follicular cells appear to be closely linked to changes in peripheral
concentrations of gonadotrophins. The mechanism of selection of dominant
follicles still requires clarification, but seems to be linked to the timing of
mRNA expression encoding LHr and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD)
in granulosal cells. Additional intraovarian systems, including the ovarian IGF
and activin/inhibin systems, also exert a role. For example, it appears that the
development of follicular dominance in cows is associated with the FSH-dependent
inhibition of the expression of mRNA encoding insulin-like growth factor binding
protein 2 (IGFBP-2) in granulosal cells. In conclusion, the integration of these
endocrine signals and intraovarian factors within follicles determines whether
follicles continue to develop and become dominant or are diverted into apoptotic
pathways leading to atresia.
PMID- 10692844
TI - Role of growth hormone in development and maintenance of follicles and corpora
lutea.
AB - Growth hormone (GH) is a pituitary hormone that affects animal growth,
metabolism, lactation, and reproduction. Many of the effects of GH are mediated
by insulin-like growth factor I (IGF-I) which is synthesized in liver and ovary
in response to GH. Insulin-like growth factor I synergizes with gonadotrophins
(LH and FSH) to stimulate growth and differentiation of ovarian cells. There are
species differences in the effects of GH in reproductive biology. In most
species, ovarian follicles and corpora lutea are potential sites for GH action
because the GH receptor is found within granulosal cells as well as corpora
lutea. However, growth hormone does not control ovarian IGF-I in all species and,
in ruminants, endocrine IGF-I from liver may be the principal mediator of GH
action. In cattle, administration of GH increases the number of small antral
ovarian follicles but does not increase the number of large antral (dominant)
follicles. Growth hormone may antagonize some aspects of dominant follicular
function because dominant follicles are shorter-lived in GH-treated cattle. The
corpora lutea has increased growth and steroidogenesis in response to GH. Growth
hormone-induced steroidogenesis in cultured granulosal and luteal cells depends
on IGF-I release after GH treatment. Bovine and ovine granulosal cells do not
release IGF-I in response to GH in vitro and, therefore, are less responsive to
GH. These results demonstrate that GH is required for normal reproductive
function in ruminant as well as nonruminant species.
PMID- 10692845
TI - Regulation of follicle waves to maximize fertility in cattle.
AB - Cattle have recurrent follicular waves every 7-10 days in most physiological
situations; an FSH increase is associated with emergence of the wave and LH pulse
frequency determines the fate of the dominant follicle. To control oestrus with
hormones it is necessary to ensure that either induced corpus luteum regression
or the termination of a progestogen treatment coincides with the selection of the
dominant follicle during the wave, to give a precise onset of oestrus and high
fertility. The exogenous administration of progesterone or progestagen blocks the
normal turnover of the dominant follicle once the corpus luteum regresses. Thus,
the effects of duration of dominance of the preovulatory follicle on onset of
oestrus and fertility were examined. The variation in onset of oestrus was
reduced but occurred 5-9 h later after 4 versus 8 days of dominance; pregnancy
rate was also affected with dominance periods of 2-4, 4-8 and > 10 days resulting
in 0, 10-15% or 20-50% reduction in pregnancy rates, respectively. The necessity
for short duration of dominance of the preovulatory follicle means that to ensure
high fertility the follicular wave needs to be regulated when using hormones to
control oestrus. Two approaches were examined, namely the use of GnRH or
oestradiol at time of progesterone intravaginal releasing device insertion. The
effect of 250 micrograms of synthetic GnRH on the fate of an existing follicle
wave was to ovulate the dominant follicle (20/20 cows) and a new wave emerged 1.6
+/- 0.3 days later; however, there was no effect of GnRH on the wave if
administered before dominant follicle selection. The effect of oestradiol
concentrations on suppression of FSH in ovariectomized heifers showed that
increasing oestradiol to 10-15 pg ml-1 caused a 37 +/- 6.9% decrease in FSH for
24 h, with a subsequent increase to pretreatment values by 57 +/- 13 h. In cyclic
heifers, increasing oestradiol to > 10 pg ml-1 in conjunction with progesterone
treatment at emergence of the first wave of the cycle affected the current
follicle wave by either preventing dominant follicle selection or decreasing
diameter of the dominant follicle, without consistently affecting the interval to
new wave emergence. Increase of oestradiol after dominance, however, delayed new
wave emergence by 2-5 days. A better understanding of the hormonal control of
follicle waves will lead to development of improved hormonal regimens to control
oestrus sufficiently to give high pregnancy rates to a single AI without recourse
to detection of oestrus.
PMID- 10692846
TI - Regulation of GnRH receptor gene expression in sheep and cattle.
AB - The GnRH receptor plays a pivotal role in reproduction. This review summarizes
current knowledge of the regulation of GnRH receptor gene expression by endocrine
factors in sheep and cattle. Expression of the GnRH receptor gene, measured by
steady-state amounts of GnRH receptor messenger RNA (mRNA), is maximal during the
preovulatory period. The molecular events leading to maximal GnRH receptor gene
expression are probably triggered by decreased circulating concentrations of
progesterone at luteolysis. Because GnRH is a positive homologous regulator of
its own receptor, increased pulsatile GnRH after removal of negative feedback
effects of progesterone stimulates expression of the GnRH receptor gene early in
the preovulatory period. Oestradiol is also a positive regulator of GnRH receptor
gene expression, and increased serum concentrations of oestradiol from developing
follicles probably maintain high abundance of GnRH receptor mRNA later in the
preovulatory period. Since increased amount of GnRH receptor mRNA precedes
maximal numbers of GnRH receptors before the LH surge, increased expression of
the GnRH receptor gene is an important mechanism by which maximal sensitivity of
gonadotrophs to GnRH is achieved. Future efforts should be directed towards
elucidating the molecular mechanisms underlying transcriptional regulation of the
GnRH receptor gene in ruminants by endocrine factors.
PMID- 10692847
TI - Follicle-stimulating isohormones: regulation and biological significance.
AB - Follicle-stimulating hormone (FSH) is a key hormone in the regulation of
follicular development. Although the existence of FSH heterogeneity is well
established, the physiological significance of this pleomorphism remains unknown.
Observed changes in circulating FSH heterogeneity during critical reproductive
events such as puberty and reproductive cyclicity suggest that different
combinations of FSH isoforms reach the target sites during different
physiological states to influence a variety of biological end points such as
cellular growth, development, steroidogenesis and protein synthesis. Considering
that these FSH isoforms have different physicochemical properties and potential
to bind not only their cognate receptors but also structurally related, non-FSH
receptors with various affinities, the regulatory implications of FSH
heterogeneity in modulating the various FSH-induced functions are enormous.
However, assigning functional significance to FSH heterogeneity has been hampered
because of (1) difficulties associated with procurement of highly purified,
naturally occurring, circulating FSH isoforms; (2) absence of reference standards
that contain the entire repertoire of FSH isoforms present in biological fluids;
and (3) specificity issues inherent to the detection systems used. If particular
FSH isoforms do possess selective biological functions, specific combinations of
FSH isoforms could be generated to regulate fertility in farm animals and humans.
PMID- 10692848
TI - Endocrine and reproductive responses of male and female cattle to agonists of
gonadotrophin-releasing hormone.
AB - The pituitary response in cattle to treatment with GnRH agonist has two phases.
In the acute phase secretion of LH is increased, while the chronic phase is
characterized by a downregulation of GnRH receptors and insensitivity of
gonadotrophs to natural sequence GnRH. After long-term treatment with GnRH
agonist, cattle do not have pulsatile secretion of LH but maintain basal LH. This
is associated with reduced pituitary contents of LH, LH mRNA, FSH and FSH mRNA.
Long-term treatment of bulls with GnRH agonist results in an increase in
testicular LH receptors and high plasma testosterone. Heifers treated with a GnRH
agonist from early in the oestrous cycle develop a larger corpus luteum and
secrete more progesterone. Increased steroidogenesis is reflected in increased
steroid acute regulatory (StAR) protein and steroidogenic enzymes in the testes
and corpus luteum. GnRH agonists have potential as novel strategies for
reproductive management in cattle. A GnRH agonist bioimplant was recently used to
block the LH surge after FSH stimulation of follicle growth in heifers. Ovulation
was induced by injection of LH, and heifers were inseminated relative to the LH
injection. This GnRH agonist-LH protocol provides a model for studying the
gonadotrophin requirements for follicular growth and oocyte maturation in cattle,
and will enable controlled in vivo maturation of oocytes before recovery for in
vitro procedures.
PMID- 10692849
TI - Control of parturition in ruminants.
AB - Parturition is a process which, when set into motion, occurs to completion. This
review concerns the control of parturition in ruminants. Parturition is an
endocrine event, dependent upon the activation of the fetal hypothalamus
pituitary-adrenal (HPA) axis. In sheep and other ruminants, increases in plasma
concentrations of cortisol induce the activity of 17-hydroxylase and 17,20 lyase
in the placenta, increasing the biosynthesis of oestrogen relative to
progesterone. The increase in the so-called E:P ratio increases myometrial
activity and culminates in labour and delivery. Much work has been done to
identify the mechanism of the endogenous activation of the fetal HPA axis. Recent
work suggests that production of prostanoids within the fetal brain influences
fetal ACTH secretion, and that induction of prostanoid biosynthesis at the end of
gestation might be important in the process of parturition. Oestrogen and
androgens, secreted by the placenta at the end of gestation, augment activity of
the fetal HPA axis by increasing fetal ACTH secretion and by decreasing negative
feedback sensitivity to cortisol. Although significant progress has been made
concerning the neuroendocrinology of parturition, many significant questions
remain. Is parturition regulated or simply programmed? Is parturition the
ultimate result of neuronal maturation within the fetal hypothalamus, or is there
a complex interplay between the placenta and fetal hypothalamus? Answers to these
and other important questions await further research, but may provide key
information which will prove useful in understanding general principles of
parturition in many mammalian species.
PMID- 10692850
TI - Implications of recent advances in reproductive physiology for reproductive
management of goats.
AB - The control of reproduction in goats is interesting for technical reasons
(synchronization of kiddings, adjustment to forage availability or to economy),
and for genetic reasons (identification and dissemination of improved genotypes).
The use of short-light rhythms leads to markedly increased production of semen
per buck and prevents occurrence of a 'resting' season. Recent identification of
a bulbourethral lipase in goat spermatozoa opens new perspectives in sperm
preservation. Light plus 'short day' treatments also allow induction of out-of
season oestrous cycles and ovulations leading to enhanced fertility. Repeated use
of eCG provokes the production of antibodies, delays the timing of ovulation and
causes a reduction in fertility after fixed-time artificial insemination. All
steps of embryo production, freezing and transfer are now controlled and allow
the attainment of satisfactory numbers of kids born per donor female, which are
compatible with the development of the technique for exchanging genotypes between
countries. In vitro production of embryos allows high development rates to be
achieved after in vitro maturation and fertilization of oocytes, and will ensure
the production of synchronous populations of one-cell zygotes at the stage
required by new biotechnologies.
PMID- 10692851
TI - Comparative reproductive function in cervids: implications for management of farm
and zoo populations.
AB - The cervids represent a complex assemblage of taxa characterized by extreme
diversity in morphology, physiology, ecology and geographical distribution.
Farmed species (for example red deer and fallow deer) are usually the common
larger-bodied, gregarious and monotocous species that express marked reproductive
seasonality in their temperate environment. Their commercial importance has
facilitated considerable research into reproductive physiology and the
development of assisted reproductive technologies (ART). In contrast, the
remaining species, including many of tropical origin, show wide diversity in
reproductive patterns, have generally received little scientific scrutiny, and
include a number of endangered taxa that are reliant on ex situ conservation
efforts (such as captive breeding) to ensure their survival. Domestication and ex
situ management programmes have been associated with widespread translocation of
various cervid species around the world, often placing the animals in
environments that are not compatible with their evolved reproductive patterns.
For example, the summer calving/lactation pattern of red deer, attuned to
northern continental climatic patterns, is frequently misaligned with seasonal
changes in feed availability in the Australasian pastoral environment. Similarly,
seasonal or aseasonal calving patterns of tropical species translocated to
temperate regions are usually associated with increased perinatal mortality of
calves born in cool seasons. Conversely, temperate species in tropical zones may
exhibit aberrant reproductive patterns in the absence of biologically significant
photoperiod fluctuations. ARTs, which presently include artificial insemination,
embryo transfer and in vitro embryo production, have potential application to the
genetic management and population growth of various cervid species. Although
application to some farmed cervid species is widespread, these technologies are
rarely directly transferable from farmed to endangered species. Even within
species, ART protocols developed successfully for one genotype (i.e. subspecies)
may be ineffective in another (for example superovulation of red deer and
wapiti). Therefore, application to genetic management of endangered species
necessitates prior research into their reproductive patterns. This is often
difficult because of the rarity of the animals, a lack of suitable handling
facilities for the particular species, and the timid nature of the deer. More
recently, however, non-invasive reproductive profiling, based on remote
collection and monitoring of excreted steroid metabolites, has facilitated such
research.
PMID- 10692852
TI - Reproduction in water buffalo: comparative aspects and implications for
management.
AB - The domestic buffalo occupies an important niche in many ecologically
disadvantaged agricultural systems, providing milk, meat and draught power.
Although buffalo can adapt to harsh environments and live on low quality forage,
their reproductive efficiency is often compromised by such conditions. Climatic
stress depresses ovarian cyclicity, oestrous expression and conception rates.
Poor nutrition, usually related to seasonal fluctuations in availability and
quality of feed, delays puberty and increases the duration of postpartum
anoestrus. Management factors such as the system of grazing (free, tethered or
none) and sucking by calves (restricted or ad libitum) also modulate reproductive
functions. Finally, the skills and capabilities of farmers as well as the quality
of support services such as artificial insemination and disease control also
influence fertility. The relative importance of these factors vary greatly
depending on ecological conditions and production systems. Improvement of
reproductive efficiency therefore requires the identification of specific
limiting factors under a given situation and the development and field testing of
strategies for improvements and interventions that are sustainable with available
local resources. The application of modern reproductive technologies in buffaloes
requires an appreciation of their biology and reproductive physiology as well as
the potentials and limitations under each specific production system.
PMID- 10692853
TI - Reproduction in female South American domestic camelids.
AB - Alpacas and llamas are induced ovulators. They show marked reproductive
seasonality in the Andean region, but under Northern Hemisphere conditions of
feeding and management, they are non-seasonal breeders. Puberty is attained when
they reach 50% of adult body weight. When they are not exposed to a male, females
show successive waves of follicular maturation and atresia. Growth, maintenance
and regression of a follicle each require an average of 4 and 6 days in alpacas
and llamas, respectively. After sterile mating, progesterone concentrations in
blood were increased from day 5, reached maximum concentrations on day 7-8, and
declined rapidly at 9-10 days after mating. A fertile mating results in formation
of a corpus luteum that remains functional throughout gestation. The duration of
gestation is 340-346 days. Almost all fetuses were found to occupy the left
uterine horn, even though ovulation occurs from both ovaries with equal
frequency. Several methods of pregnancy diagnosis have been described. Mating is
recommended within 15-20 days after parturition to obtain good fertility rates
and one offspring per year. The factors that contribute to high rates of
embryonic mortality are unknown. Reproductive technologies, such as AI,
superovulation, embryo transfer and IVF, have not been used very extensively in
these species but can be successfully applied.
PMID- 10692854
TI - Growth and development of the corpus luteum.
AB - The mammalian corpus luteum, which plays a central role in the reproductive
process because of its production of hormones such as progesterone, is an
exceptionally dynamic organ. Growth and development of the corpus luteum are
extremely rapid, and even when the corpus luteum is functionally mature cellular
turnover remains high. Associated with this high rate of cell turnover, the
mature corpus luteum receives the greatest blood supply per unit tissue of any
organ, and also exhibits a relatively high metabolic rate. Central to the growth
and development of the corpus luteum, therefore, is luteal vascular growth, which
appears to be regulated primarily by the angiogenic growth factors, basic
fibroblast growth factor and vascular endothelial growth factor. In addition, the
corpus luteum is a complex tissue composed of parenchymal (small and large
steroidogenic) and nonparenchymal (for example fibroblasts, vascular smooth
muscle, pericytes and endothelial) cells. Recent studies evaluating the
expression, location and regulation of gap junctions in the corpus luteum
indicate an important role of gap junctional intercellular communication in the
coordination of function among these diverse cell types during luteal growth and
development. These studies will lead to an improved understanding not only of
luteal function but also of tissue growth and development in general.
PMID- 10692855
TI - Molecular regulation of luteal progesterone synthesis in domestic ruminants.
AB - Regulation of progesterone secretion from the corpus luteum during the oestrous
cycle requires the integration of multiple signals to achieve the appropriate
amount of progesterone to maximize reproductive efficiency. Development of a
mature corpus luteum capable of secreting sufficient amounts of progesterone is
dependent upon the pituitary hormones LH and growth hormone (GH). Continued
secretion of progesterone from the mature corpus luteum is also dependent upon
pituitary hormones. If pregnancy does not occur, prostaglandin F2 alpha (PGF2
alpha) of uterine origin causes a precipitous decrease in progesterone secretion
and demise of the corpus luteum. A major point of regulation of progesterone
secretion by both luteotrophic and luteolytic hormones appears to be regulation
of transport of cholesterol through the mitochondrial membranes to cytochrome
P450scc. It is likely that both luteotrophic and luteolytic hormones regulate
steroidogenic acute regulatory protein (StAR), which facilitates transport.
Regulation may be occurring through increases or decreases in gene transcription,
translation efficiency or post-translational modifications such as
phosphorylation. Thus, although synthesis of progesterone is a complex process,
both positive and negative regulation of the process appears to occur primarily
at a single step (transport of cholesterol to the inner mitochondrial membrane)
in the pathway.
PMID- 10692856
TI - Luteal peptides and their genes as important markers of ovarian differentiation.
AB - Secreted peptide hormones and components of the steroidogenic machinery are
molecules that are expressed usually in high amounts and in a time- and cell
specific fashion within the cells that give rise to the bovine corpus luteum.
They thus serve as useful markers for the events occurring within the nuclei of
these cells that result in differentiation and the expression of the specific
luteal phenotype. We have studied the bovine genes of three such luteal products:
oxytocin, the new relaxin-like factor (RLF), and the steroidogenic acute
regulatory protein (StAR). The oxytocin gene is expressed in the granulosal cells
of the preovulatory follicle and in the large luteal cells of the immediately
resulting early corpus luteum. The RLF gene is a major thecal cell product in
antral and atretic follicles. It is also transcribed in luteal cells, but only in
the mid- to late ovarian cycle and in pregnancy, following a temporal pattern of
expression very similar to that of relaxin in pigs. The StAR gene appears to be
upregulated only in the mid- to late ovarian cycle, several days after the
increase in steroidogenic enzymes associated with luteinization and progesterone
production. All three genes make use of the transcription factor SF-1 (Ad4BP)
and, although they all respond to LH activation of adenylate cyclase, none
utilize CRE-linked systems. Specific transcriptional activation must involve
other factors to encode the information for the widely diverse temporal and
cellular patterns of gene expression for these three genes.
PMID- 10692857
TI - Intraovarian regulation of luteolysis.
AB - The corpus luteum is a transient gland, which is only functional for 17-18 days
in the cyclic cow or for up to 200 days in the pregnant cow. Regression of the
corpus luteum is essential for normal cyclicity as it allows the development of a
new ovulatory follicle, whereas prevention of luteolysis is necessary for the
maintenance of pregnancy. Evidence acquired over the past three decades indicated
that PGF2 alpha is the luteolytic hormone in ruminants. Nevertheless, the
detailed mechanisms of PGF2 alpha action are just beginning to be clarified. A
pivotal role for an endothelial cell product endothelin 1 (ET-1) has been
documented in PGF2 alpha-induced luteal regression. ET-1 inhibited progesterone
production by luteal cells in a dose-dependent manner via selective ET-1 binding
sites (ETA). The inhibitory action of PGF2 alpha on progesterone secretion (in
vivo and in vitro) was blocked by a selective ETA receptor antagonist. This
implied that ET-1 (through ETA receptors present on steroidogenic cells) may have
mediated the inhibitory effect of PGF2 alpha. The involvement of ET-1 in luteal
regression was also suggested by the observation that the highest concentrations
of ET-1 coincide with uterine PGF2 alpha surges. Furthermore, PGF2 alpha
administration upregulated ET-1 expression within the corpus luteum. Later stages
of luteal regression, which involve programmed cell death (PCD), are presumably
mediated by immune cells. ET-1 may also be involved in this process by promoting
leukocyte migration and stimulating macrophages to release tumour necrosis factor
alpha (TNF alpha). The TNF alpha receptor type 1 (p55) is present on luteal cells
(endothelial and steroidogenic cells) and could initiate PCD and the structural
demise of the corpus luteum.
PMID- 10692858
TI - Regulation of gonadotrophin-releasing hormone secretion by testosterone in male
sheep.
AB - In males, including the ram, testosterone, acting via its primary metabolites
oestradiol and dihydrotestosterone (DHT), suppresses circulating LH
concentrations. This effect is due primarily, although not totally, to decreased
frequency of gonadotrophin-releasing hormone (GnRH) pulses. The arcuate
ventromedial region (ARC-VMR) of the mediobasal hypothalamus and possibly the
medial preoptic area (mPOA) are sites at which oestradiol acts to suppress GnRH,
but the site of DHT action is not known. Given that native GnRH neurones appear
to contain few or no oestrogen or androgen receptors, the effects of testosterone
metabolites probably are exerted by modulating activity of inhibitory
interneurone systems such as beta-endorphin, dopamine, and gamma-aminobutyric
acid (GABA). Although beta-endorphin clearly inhibits GnRH secretion, the
observation that testosterone treatment during a long-day photoperiod reduced
proopiomelanocortin (POMC) mRNA in the arcuate nucleus while coincidentally
suppressing GnRH release indicates that beta-endorphin does not mediate the
inhibitory effect of testosterone on GnRH. Activation of GABAA receptors in
either the mPOA or ARC-VMR suppressed LH, whereas activation of GABAB receptors
in the ARC-VMR increased LH pulse amplitude. Therefore, it is suggested that GABA
acts in both regions to regulate LH. Whereas testosterone affects GABA metabolism
in the rat hypothalamus, its effect in the ram hypothalamus is yet to be
determined. Testosterone treatment activated dopaminergic cells in the
retrochiasmatic A15 area in the same animals in which it suppressed POMC mRNA in
the arcuate nucleus. This dopaminergic system may partially mediate the negative
feedback effect of testosterone in the ram analogous to its role in partially
mediating the negative effect of oestrogen in the ewe. Future studies must
concentrate on determining how these and other putative inhibitory neuronal
systems interact and how they in turn are regulated by environmental factors such
as photoperiod.
PMID- 10692859
TI - Role of male-female interaction in regulating reproduction in sheep and goats.
AB - The induction of synchronous ovulatory activity in anovulatory sheep and goats
after the introduction of males, the 'male effect', has probably been used to
advantage since these species were domesticated and the underlying physiological
and behavioural mechanisms have been progressively elucidated over the past 50
years. Less well understood is the analogous effect of oestrous females on males.
This review examines the nature and importance of these male-female interactions
in sheep and goats, and describes the most important internal and external
factors influencing the reproductive outcomes of such interactions. It is
proposed that the male and female effects are both components of a self
reinforcing cycle of stimulation that, under ideal conditions, culminates in the
synchronous very rapid onset (within days) of fertile reproductive activity.
However, precisely because of the speed of this response, it is suggested that
mechanisms have evolved to limit its efficacy, and thus prevent conception at
inappropriate times. The complexity of these factors and the interactions between
them are highlighted, and a broad conceptual framework for understanding them is
proposed based upon an appreciation of variation in both the responsiveness of
the target animal and the quality of the signal from the signalling animal.
PMID- 10692860
TI - Sexual behaviour of rams: male orientation and its endocrine correlates.
AB - The components of heterosexual behaviour in rams are reviewed as a basis for
understanding partner preference behaviour. A small percentage of rams will not
mate with oestrous females and if given a choice will display courtship behaviour
towards another ram in preference to a female. Some of the endocrine profiles of
these male-oriented rams differ from those of heterosexual controls. These
differences include reduced serum concentrations of testosterone, oestradiol and
oestrone, reduced capacity to produce testosterone in vitro, and reduced capacity
to aromatize androgens in the preoptic-anterior hypothalamus of the brain. Our
observation that aromatase activity is significantly lower in the preoptic
anterior hypothalamic area of male-oriented rams than in female-oriented rams may
indicate an important neurochemical link to sexual behaviour that should be
investigated. The defect in steroid hormone production by the adult testes of the
male-oriented ram may represent a defect that can be traced to the fetal testes.
If this contention is correct, partner preference behaviour of rams may also be
traceable to fetal development and represent a phenomenon of sexual
differentiation.
PMID- 10692861
TI - The functional integrity and fate of cryopreserved ram spermatozoa in the female
tract.
AB - Cryopreservation advances capacitation-like changes in ram spermatozoa. These
changes are reflected in an increased fertilizing ability compared with fresh
spermatozoa, followed by an accelerated decline in fertilizing ability after
incubation in vitro or in vivo. Furthermore, frozen-thawed spermatozoa are
released earlier than fresh spermatozoa after binding to oviduct cells in vitro,
confirming their physiological readiness to participate in fertilization despite
their short lifespan. After insemination large numbers of spermatozoa are lost
from the female reproductive tract of the ewe via the vagina. Frozen-thawed
spermatozoa are expelled faster than fresh spermatozoa. The advanced membrane
status of frozen-thawed spermatozoa may provoke their rapid loss and possibly
makes them more vulnerable to attack by uterine leucocytes, or by some other
mechanism, as a high proportion of spermatozoa lost from the tract are
decapitated. The observed destabilization of the membranes of cryopreserved
spermatozoa is accompanied by impaired sperm transport, associated with
mitochondrial injury, necessitating intrauterine deposition of frozen-thawed
semen to obtain satisfactory fertility after artificial insemination. However,
the frozen-thawed spermatozoa that can participate in fertilization may
contribute to increased embryonic loss by the advancement of cleavage or through
a direct effect of cryopreservation on the male genome.
PMID- 10692862
TI - Uterine differentiation as a foundation for subsequent fertility.
AB - Uterine differentiation in cattle and sheep begins prenatally, but is completed
postnatally. Mechanisms regulating this process are not well defined. However,
studies of urogenital tract development in murine systems, particularly those
involving tissue recombination and targeted gene mutation, indicate that the
ideal uterine organizational programme evolves epigenetically through dynamic
cell-cell and cell-matrix interactions that define the microenvironmental context
within which gene expression occurs and may ensure adult tissue stability. In the
cow and ewe, transient postnatal exposure of the developing uterus to steroids
can produce immutable changes in adult uterine tissues that may alter the
embryotrophic potential of the uterine environment. Thus, success of steroid
sensitive postnatal events supporting uterine growth and development can dictate
the functional potential of the adult uterus. Studies to determine effects of
specific steroidal agents on patterns of uterine development during defined
neonatal periods, as well as the functional consequences of targeted neonatal
steroid exposure in the adult uterus, should enable identification of critical
developmental mechanisms and determinants of uterine integrity and function.
Extreme adult uterine phenotypes (lesion models) created in cattle and sheep by
strategic postnatal steroid exposure hold promise as powerful tools for the study
of factors affecting uterine function and the rapid identification of novel
uterine genes.
PMID- 10692863
TI - IGF paracrine and autocrine interactions between conceptus and oviduct.
AB - Development in vitro is influenced by embryo density, serum, somatic cell co
culture and the production of 'embryotrophic' paracrine and autocrine factors.
Research in our laboratory has focussed principally on the insulin-like growth
factor (IGF) family. We have demonstrated that pre-attachment bovine and ovine
embryos express mRNAs encoding a number of growth factor ligand and receptor
genes including all members of the IGF ligand and receptor family throughout this
developmental interval. In addition, early embryos express mRNAs encoding IGF
binding proteins (IGFBPs) 2-5 from the one-cell to the blastocyst stage and
IGFBP5 mRNA at the blastocyst stage. Cultured bovine blastocysts release up to 35
pg per embryo in 24 h, whereas release of IGF-I was below detectable values.
Analysis extended to bovine oviductal cultures has also demonstrated that mRNAs
encoding these IGF family members are present throughout an 8 day culture period.
Transcripts encoding IGFBPs 2-6 were also present. Release of both IGFs was
recorded over an 8 day culture period. IGF-II release was significantly greater
than that observed for IGF-I. Therefore, the IGFs are present throughout the
maternal environment during early embryo development. The oocyte, within the
follicle, is held in an environment high in IGFs and IGFBPs. The zygote, after
fertilization, is maintained in an IGF-rich environment while free-living in the
oviduct and the uterus. This review is focused on the IGF family and IGFBPs and
their roles in enhancing development up to the blastocyst stage.
PMID- 10692864
TI - The regulation of interferon-tau production and uterine hormone receptors during
early pregnancy.
AB - During early pregnancy the bovine embryo must produce a protein called interferon
tau which inhibits the development of the luteolytic mechanism. Failure to
inhibit luteolysis is the major cause of pregnancy loss in cows. The embryo must
produce sufficient quantities of interferon tau by about day 16 to prevent
luteolysis. Its ability to achieve this is largely dependent on the pattern of
maternal progesterone production. A late rise in progesterone after ovulation or
poor progesterone secretion during the luteal phase results in the development of
poor embryos capable of producing little or no interferon tau at the critical
time. The embryo inhibits luteolysis by preventing development of oxytocin
receptors on the luminal epithelium of the uterine endometrium and thus oxytocin
induced secretion of PGF2 alpha and by the induction of a prostaglandin synthesis
inhibitor within the endometrium. In sheep it has been hypothesised that
interferon tau acts to inhibit endometrial oestrogen receptors and thus oestrogen
induced up-regulation of oxytocin receptors. In cows, the embryo inhibits the
development of oxytocin receptors and the initiation of luteolysis without
causing any change in uterine oestrogen receptors. Thus in the cow, the mechanism
by which interferon tau inhibits oxytocin receptor development remains to be
determined.
PMID- 10692866
TI - Roles of extracellular matrix in follicular development.
AB - The cellular biology and changes in the extracellular matrix of ovarian follicles
during their development are reviewed. During growth of the bovine ovarian
follicle the follicular basal lamina doubles 19 times in surface area. It changes
in composition, having collagen IV alpha 1-26 and laminin alpha 1, beta 2 and
gamma 1 at the primordial stage, and collagen IV alpha 1 and alpha 2, reduced
amounts of alpha 3-alpha 5, and a higher content of laminin alpha 1, beta 2 and
gamma 1 at the antral stage. In atretic antral follicles laminin alpha 2 was also
detected. The follicular epithelium also changes from one layer to many layers
during follicular growth. It is clear that not all granulosal cells have equal
potential to divide, and we have evidence that the granulosal cells arise from a
population of stem cells. This finding has important ramifications and supports
the concept that different follicular growth factors can act on different subsets
of granulosal cells. In antral follicles, the replication of cells occurs in the
middle layers of the membrana granulosa, with older granulosal cells towards the
antrum and towards the basal lamina. The basal cells in the membrana granulosa
have also been observed to vary in shape between follicies. In smaller antral
follicles, they were either columnar or rounded, and in follicles > 5 mm the
cells were all rounded. The reasons for these changes in matrix and cell shapes
are discussed in relation to follicular development.
PMID- 10692865
TI - Mechanism of action of interferon-tau in the uterus during early pregnancy.
AB - Early pregnancy is maintained in ruminants through the actions of conceptus
derived interferon (IFN)-tau on the endometrium. IFN-tau alters uterine release
of PGF2 alpha' which results in rescue of the corpus luteum and continued release
of progesterone. The mechanism of action of IFN-tau includes inhibition of
oestradiol receptors, consequent reduction in oxytocin receptors, activation of a
cyclooxygenase inhibitor, and a shift in the PGs to favour PGE2 over PGF2 alpha'
IFN-tau also induces several endometrial proteins that may be critical for
survival of the developing embryo. One endometrial protein induced by pregnancy
and IFN-tau has been identified as bovine granulocyte chemotactic protein-2 (bGCP
2). This chemotactic cytokine (chemokine) has been used as a marker to delineate
IFN-tau from IFN-alpha responses in the endometrium. A second protein, called
ubiquitin cross-reactive protein (UCRP), resembles a tandem ubiquitin repeat.
UCRP becomes conjugated to cytosolic endometrial proteins in response to IFN-tau
and pregnancy. Proteins conjugated to UCRP are either modulated or targeted for
processing through the proteasome. The action of IFN-tau is mediated by induction
of signal transducer and activator of transcription 1 (STAT-1), STAT-2 and
interferon regulatory factor 1 (IRF-1) transcription factors. Induction of these
transcription factors, the alpha chemokines and UCRP is the prelude to maternal
recognition of pregnancy in ruminants.
PMID- 10692867
TI - Plasmin-tumour necrosis factor interaction in the ovulatory process.
AB - Collagen breakdown and apoptotic cell death within the apex of the preovulatory
ovine follicle are hallmarks of impending ovarian rupture. An integrative
mechanism is proposed whereby gonadotrophic stimulation of urokinase-type
plasminogen activator secretion by the follicular-contiguous ovarian surface
epithelium elicits a localized increase in tissue plasmin, which activates
collagenolysis and tumour necrosis factor alpha-induced cell death within the
formative ovulatory stigma.
PMID- 10692868
TI - Growth factors and extracellular matrix proteins in interactions of cumulus
oocyte complex, spermatozoa and oviduct.
AB - The expression and localization of selected growth factor systems and
extracellular matrix (ECM) components that may influence oocyte maturation and
fertilization within the mammalian oviduct are reported. Fibroblast growth factor
(FGF) and vascular endothelial growth factor (VEGF) systems could be detected by
use of RT-PCR, RNase protection assay (RPA) and immunohistochemistry in bovine
follicles, bovine cumulus-oocyte complexes (COC) and bovine and marmoset
oviducts. Two different subtypes of the FGF receptor (FGFR-1 and -2) were
identified in distinct cell types, indicating a functional difference. A complete
epidermal growth factor (EGF) system was found in the porcine, but not in the
bovine, oviduct. There were additional differences between bovine and primate
oviducts: FGF-1/2 and FGFR were increased in the marmoset around ovulation, in
contrast to an increase in FGF-1 in the cow. Immunohistochemistry revealed
accumulation and storage of FGF and VEGF on the surface of the epithelium,
possibly due to their binding property on heparanglycoproteins. Other ECM
components, matrix metalloproteinase 1 (MMP-1) and tissue inhibitor of
metalloproteinase 1 (TIMP-1), were found to be modulated in the ovarian follicle,
COC and oviduct during the cycle. An oviduct-mediated depletion of sperm surface
proteins (BSP1-3) was discovered as well as a sperm-induced novel oviductal mRNA
related to an anti-oxidant protein family. Associated systems of growth factors
and ECM components can be suggested as paracrine or autocrine mediators during
fertilization in a species-, cycle- and tissue-dependent manner.
PMID- 10692869
TI - Regulation of ovarian extracellular matrix remodelling by metalloproteinases and
their tissue inhibitors: effects on follicular development, ovulation and luteal
function.
AB - In most organs, remodelling of tissues after morphogenesis is minimal; however,
normal ovarian function depends upon cyclical remodelling of the extracellular
matrix (ECM). The ECM has a profound effect on cellular functions and probably
plays an important role in the processes of follicular development and atresia,
ovulation, and development, maintenance and regression of corpora lutea. Matrix
metalloproteinases (MMPs; collagenases, gelatinases, stromelysins and membrane
type MMPs) cleave specific components of the ECM and are inhibited by tissue
inhibitors of metalloproteinases (TIMPs). MMPs have been detected at all stages
of follicular development and probably modulate follicular expansion or atresia
within the ovarian stroma. In addition, increased MMP activity appears to be
required for ovulation since follicular rupture occurred in the absence of
plasminogen activator activity and inhibitors of MMPs blocked follicular rupture.
Development and luteolysis of the corpus luteum are accompanied by extensive
remodelling of the ECM. Differentiation and regression of luteal cells are
associated with construction and degradation of ECM, respectively. There is
increasing evidence that ECM components enhance luteinization; whereas loss of
ECM results in luteal cell death. Ovine large luteal cells may be the primary
type of cell responsible for controlling the extent of remodelling of luteal ECM
since they produce TIMP-1, TIMP-2 and plasminogen activator inhibitor 1. The
ratio of active MMPs to TIMPs may be important in maintaining an ECM
microenvironment conducive to the differentiation of follicular-derived cells
into luteal cells, and maintenance of the phenotype of luteal cells.
PMID- 10692870
TI - Nutrition and fetal growth: paradoxical effects in the overnourished adolescent
sheep.
AB - Inappropriate maternal nutrient intake at key developmental timepoints during
ovine pregnancy has a profound influence on the outcome of pregnancy and aspects
of postnatal productivity. However, the responses to alterations in maternal
nutrition in adult sheep are often highly variable and inconsistent between
studies. The growing adolescent sheep provides a new, robust and nutritionally
sensitive paradigm with which to study the causes, consequences and reversibility
of prenatal growth restriction. Overnourishing the adolescent dam to promote
rapid maternal growth throughout pregnancy results in a major restriction in
placental mass, and leads to a significant decrease in birthweight relative to
moderately fed, normally growing adolescents of equivalent gynaecological age.
Maternal insulin and IGF-I concentrations are increased from an early stage of
gestation in overnourished adolescent dams and these hormones ensure that the
anabolic drive required to promote maternal tissue synthesis is initiated at a
time when the nutrient requirements of the gravid uterus are low. The major
restriction in fetal growth in rapidly growing dams occurs irrespective of high
concentrations of essential nutrients in the maternal circulation and suggests
that the small size or altered metabolic and transport capacity of the placenta
is the primary constraint to fetal growth. The decrease in placental weight in
the overnourished animals reflects a significant reduction in both fetal
cotyledon number and mean cotyledon weight. The role of nutritionally mediated
alterations in progesterone and the components of the IGF system in this early
pregnancy placental phenomenon are being investigated. Nutritional switch-over
studies have demonstrated that reducing maternal nutrient intake at the end of
the first third of pregnancy can stimulate placental growth and enhance pregnancy
outcome, but increasing nutrient intake at this time has a deleterious effect on
placental development and fetal growth.
PMID- 10692871
TI - Placental transport of nutrients and its implications for fetal growth.
AB - Placental growth during early and mid-pregnancy has a powerful, constraining
influence on fetal growth during late pregnancy. Studies involving surgical and
environmental reduction of placental size in sheep have shown an associated
reduction in capacity to transport oxygen, glucose and amino acids. Oxygen
transport is limited by placental blood flow but transport of glucose and amino
acids is determined by the abundance and activity of specific transport proteins.
Glucose transporters include the GLUT1 and GLUT3 isoforms previously identified
in brain and other tissues; systems for active transport of amino acids have been
inferred but not characterized. Placental metabolism of glucose and amino acids
has major effects both on the quantity of carbon and nitrogen delivered to the
fetus, and on the composition of substrates involved. For example, the
uteroplacental tissues consume more than 60% of uterine glucose uptake during
late pregnancy, and the placenta substantially modifies the pattern of amino
acids delivered to fetal blood. The placenta also participates in the array of
metabolic adaptations of maternal and conceptus tissues to altered maternal
nutrient supply. Placental capacity for glucose transport in moderately
undernourished ewes is upregulated, partly by increased expression of the GLUT3
transport protein. During more severe glucose deprivation, placental transfer and
fetal uptake of glucose are constrained in proportion with maternal supply,
leading to fetal growth retardation.
PMID- 10692872
TI - Effects of energy balance on follicular development and first ovulation in
postpartum dairy cows.
AB - As milk production has increased during the past four decades, conception rates
in lactating cows have declined. Although reduced reproductive performance has
been associated with high milk yields, measures of postpartum ovarian activity
have been more closely related to energy balance. The relationship between daily
energy balance and postpartum reproductive activity is confirmed by longer
intervals to first ovulation in cows with greater body condition loss. Patterns
in daily energy balance, such as improvement from nadir, have been correlated
with enhanced follicular function and a shorter interval to first ovulation. Such
observations are consistent with increased LH pulse frequency following the
energy balance nadir in lactating dairy cows. Evidence indicates a primarily
hypothalamic locus for the modulation of LH secretion during negative energy
balance. Formation of follicular waves after parturition begins synchronously in
response to increased FSH in the first week postpartum, and is typically not a
limiting factor in reproductive recrudescence. Altered follicular responsiveness
to gonadotrophic support through changes in metabolic hormones such as insulin
like growth factor I (IGF-I) and insulin may contribute to impaired function of
dominant follicles early postpartum. Positive relationships between changes in
energy balance, peripheral IGF-I and function of dominant follicles support the
identification of IGF-I and the day of the energy balance nadir as metabolic
modulators of postpartum ovarian activity in dairy cows.
PMID- 10692873
TI - The role of leptin in nutritional status and reproductive function.
AB - Infertility associated with suboptimal nutrition is a major concern among
livestock producers. Undernourished prepubertal animals will not enter puberty
until they are well fed; similarly, adult, normally cyclic females will stop
cycling when faced with extreme undernutrition. Work in our laboratory has
focused on how body fat (or adiposity) of an animal can communicate to the brain
and regulate reproductive competence. In 1994, the discovery in rodents of the
obese (ob) gene product leptin, secreted as a hormone from adipocytes, provided a
unique opportunity to understand and hence regulate whole body compositional
changes. There is now evidence that similar mechanisms are functioning in
livestock species in which food intake, body composition, and reproductive
performance are of considerable economic importance. Leptin has been reported to
be a potent regulator of food intake and reproduction in rodents. There is
evidence indicating that at least some of the effects of leptin occur through
receptor-mediated regulation of the hypothalamic protein neuropeptide Y (NPY).
NPY is a potent stimulator of food intake, is present at high concentrations in
feed-restricted cattle and ewes, and is an inhibitor of LH secretion in these
livestock species. In our investigations in sheep, we have cloned a partial cDNA
corresponding to the ovine long-form leptin receptor, presumably the only fully
active form, and have localized the long-form leptin receptor in the ventromedial
and arcuate nuclei of the hypothalamus. Leptin receptor mRNA expression was
colocalized with NPY mRNA-containing cell bodies in those regions. We have also
determined that hypothalamic leptin receptor expression is greater in feed
restricted ewes than in well-fed ewes. These observations provide a foundation
for future investigations into the nutritional modulators of reproduction in
livestock.
PMID- 10692874
TI - Activation of primordial follicles in vitro.
AB - The resting pool of primordial follicles in mammalian ovaries is a potential
resource for the genetic manipulation of domestic animals, the preservation of
endangered species, and the amelioration of some forms of infertility in humans.
Exploitation of this large reservoir of follicles depends on the development of
methods for activating primordial follicles to begin growth in vitro and of
methods for sustaining follicular growth to the stage at which oocytes are
capable of meiotic maturation, fertilization and development to live young. It
has been shown that primordial follicles of rodents, cattle and primates can
initiate growth in vitro, even in serum-free medium. The signals that cause
primordial follicles to leave the resting pool or remain quiescent are unknown.
However, of interest is the observation that in cultures of whole rodent ovaries
an apparently normal number of follicles leaves the resting pool and begins to
grow, whereas in cultures of isolated bovine or primate ovarian cortex almost all
primordial follicles activate and develop into primary follicles. This finding
suggests that non-cortical portions of the ovary may regulate the flow of
follicles from the resting reservoir. In cattle, it has been difficult to sustain
follicular growth beyond the primary stage and the development of methods for
doing so are critical for achievement of the practical goal of use of the
primordial pool for embryo production. However, the development of murine
follicles in vitro from the primordial stage through oocyte maturation and
fertilization, and the birth of one pup, provides encouragement for efforts to
achieve similar results in large mammals.
PMID- 10692875
TI - Aspects of follicular and oocyte maturation that affect the developmental
potential of embryos.
AB - The ability to mature, be fertilized and finally to develop into a viable embryo
is acquired gradually by the oocyte during progressive differentiation throughout
folliculogenesis. This process starts with oocyte growth during the first steps
of follicular development. As the oocyte is close to its final size, other
modifications occur, less spectacular but at least as important in determining
the resulting ability of the oocyte to accomplish its reproductive purpose
(developmental competence). These modifications, referred to as 'oocyte
capacitation', are probably influenced by the follicle. The proportion of
developmentally competent oocytes increases with follicular size. However, the
relationship between follicular growth and oocyte competence is not very strict,
since a given oocyte may acquire its competence at any stage of follicular growth
and since some examples of functional disjunction between follicular size and
oocyte competence are described. Follicular atresia may impair the acquisition of
oocyte competence, as evidenced by the parallel study of follicular
characteristics and of the developmental potential of their oocytes treated
individually through in vitro maturation, fertilization and development. However,
when atresia is experimentally induced in large preovulatory follicles, oocytes
remain competent, indicating that once competence is acquired, it is no longer
sensitive to atresia. Oocyte maturation represents only the end of this long and
progressive process and validates the preparation of the oocyte by conferring its
final developmental ability. As evidenced by recent cloning experiments, the
cytoplasmic aspects of oocyte maturation are crucial for the acquisition of
developmental competence. This cytoplasmic maturation may be activated in vitro
by the use of complex media supplement (serum, follicular fluid) but the use of
defined media for maturation allowed the identification of some active factors
(such as epidermal growth factor, growth hormone, inhibin and activin). The study
of some differential models of oocyte competence (follicular size and atresia,
Booroola gene, prepubertal oocytes) will provide a better understanding of oocyte
capacitation and maturation, and allow the improvement of in vitro methods for
oocyte maturation, which represent the most limiting step of in vitro production
of embryos in large mammals.
PMID- 10692876
TI - Development of serum-free culture systems for the ruminant embryo and subsequent
assessment of embryo viability.
AB - The mammalian embryo undergoes considerable changes in its physiology and energy
metabolism as it proceeds from the zygote to the blastocyst stage. Complete
development of the mammalian zygote in vitro was restricted to a few strains of
mice and their F1 hybrids for many years, as the ruminant embryo arrested
development at the 8- to 16-cell stage. The introduction of co-culture of
ruminant embryos with somatic cells in the mid-1980s helped to alleviate this in
vitro induced arrest. However, such culture systems required the use of complex
tissue culture media and serum. Serum has subsequently been shown to induce
several abnormalities during embryo development in culture and has been
associated with the production of offspring with significantly greater birth
weights than normal, leading to both difficulties in pregnancy management and an
unacceptable frequency of neonatal death. Resurgence of interest in mammalian
embryo physiology has culminated in the formulation of defined embryo culture
media, capable of supporting a high percentage of viable blastocyst development
in vitro. Optimum embryo development in culture has been shown to take place not
in one, but two or more media, each designed to cater for the changing
requirements and metabolism of the embryo as it develops. The development of
viability assays to identify those embryos with the highest developmental
potential will further increase the efficiency of embryo transfer procedures.
Assays based upon nutrient uptake and subsequent utilization make promising
candidates.
PMID- 10692877
TI - Sexing mammalian spermatozoa and embryos--state of the art.
AB - Methods for sexing preimplantation embryos range from karyotyping to recording
speed of development in vitro. The only method used routinely on a commercial
scale is to biopsy embryos and amplify Y-chromosome-specific DNA using the
polymerase chain reaction. This method is effective for more than 90% of embryos
and is > 95% accurate. Within males, spermatozoa are essentially identical
phenotypically due to: (1) connection of spermatogenic cells by intercellular
bridges, (2) transcriptional inactivation of sex chromosomes during meiosis and
spermiogenesis, (3) severe limitation of all gene expression during the later
stages of spermiogenesis, and (4) coating all spermatozoa with common
macromolecules during and after spermiogenesis. One consequence is that no
convincing phenotypic difference has been detected between X- and Y-chromosome
bearing spermatozoa. The only consistently successful, nondestructive approach to
sexing spermatozoa is to quantify DNA in spermatozoa using a fluorescing DNA
binding dye followed by flow cytometry and cell sorting. X-chromosome-bearing
ruminant spermatozoa have about 4% more DNA compared with Y-chromosome-bearing
spermatozoa; accuracy of sorting can exceed 90% routinely, and sorting rates
currently exceed 10(3) live spermatozoa of each sex chromosome composition s-1.
Hundreds of apparently normal offspring from a number of species have been
produced from sexed semen, some via intrauterine artificial insemination.
PMID- 10692878
TI - Nuclear transfer from somatic cells: applications in farm animal species.
AB - The reconstruction of mammalian embryos by transfer of a blastomere nucleus to an
enucleated oocyte or zygote allows for the production of genetically identical
individuals. This has advantages for research (that is, as biological controls)
and commercial applications (that is, multiplication of genetically valuable
livestock). However, the number of offspring that can be produced from a single
embryo is limited both by the number of blastomeres (embryos at the 32-64-cell
stage are the most widely used in farm animal species) and the limited efficiency
of the nuclear transfer procedure. The ability to produce live offspring by
nuclear transfer from cells that can be propagated and maintained in culture
offers many advantages, including the production of many identical offspring over
an extended period (since cultured cells can be frozen and stored indefinitely)
and the ability to modify genetically or to select populations of cells of
specific genotypes or phenotypes before embryo reconstruction. This objective has
been achieved with the production of lambs using nuclei from cultured cells
established from embryonic, fetal and adult material. In addition, lambs
transgenic for human factor IX have been produced from fetal fibroblasts
transfected and selected in culture.
PMID- 10692879
TI - Death in custody.
PMID- 10692880
TI - Nutritional causes of impaired fetal growth and their treatment.
PMID- 10692881
TI - Multiple chemical sensitivity--is the environment really to blame?
PMID- 10692882
TI - Imprecision in medical communication: study of a doctor talking to patients with
serious illness.
AB - Uncertainty is believed to be a central feature in illness experiences.
Conversations between a consultant hematologist and 61 seriously ill patients
were transcribed, entered on a database and scrutinized for patterns of language
uncertainty by linguistic concordancing analysis. Transcripts were then discussed
in detail with the hematologist, and techniques of protocol analysis were used to
gain insight into his thought processes during consultations. The main findings
were that the doctor used many more expressions of uncertainty than did patients:
that evaluative terms were widely used to reassure rather than to worry patients;
and that patients and doctor together used certain key terms ambiguously, in a
manner which allowed the doctor to feel that facts were not misrepresented while
perhaps permitting the patient to feel reassured.
PMID- 10692883
TI - Attitudes to organ donation among South Asians in an English high street.
AB - In the UK, people of South Asian origin are at more than twice the risk of end
stage renal failure encountered in the Caucasian population but are under
represented among organ donors. Difficulties with matching mean that few donated
kidneys are suitable for transplantation to South Asian recipients. A survey of
attitudes in 100 South Asian adults was conducted in the main street of Southall,
Middlesex. 90 of those questioned were aware of organ transplantation and 69 had
heard about donor cards. However, the 16% who carried a donor card was lower than
the 28% reported in the general population. The main reason for the low organ
donation rate by South Asians seemed to be lack of knowledge, and this could be
remedied by more targeting of information in the Asian media.
PMID- 10692884
TI - Hysterosalpingo contrast sonography as a screening test for tubal patency in
infertile women.
AB - The most informative method for assessing tubal patency in subfertile women is
laparoscopy-and-dye. This investigation, however, puts a large burden on services
and a screening test is needed that identifies a high likelihood of occlusion. In
our infertility programme we introduced hysterosalpingo contrast sonography for
this purpose, operated entirely by ultrasonographers. A series of audits
indicated that this innovation speeded the process of investigation by several
weeks and reduced the number of laparoscopy-and-dye procedures by 75%. The
negative predictive value was 89% and the positive predictive value was 44%. The
main limitation of the method was the long period required for training, in those
without extensive experience of vaginal ultrasonography.
PMID- 10692885
TI - The dos and don'ts of examining the respiratory system: a survey of British
Thoracic Society members.
PMID- 10692886
TI - Recurrent renal cholesterol embolism.
PMID- 10692887
TI - Systemic vasculitis with multiple aneurysms complicating systemic lupus
erythematosus.
PMID- 10692888
TI - Aortic dissection with chronic haemopericardium.
PMID- 10692889
TI - Appendico-cutaneous fistula.
PMID- 10692890
TI - Caduceus, porcelain and palette: John Wall of Worcester.
PMID- 10692891
TI - I drink, therefore I am: alcohol and creativity.
PMID- 10692892
TI - Neurology in the National Gallery.
PMID- 10692893
TI - Multicentre research ethics committees.
PMID- 10692894
TI - Severe parkinsonism secondary to carbon monoxide poisoning.
PMID- 10692895
TI - Antioxidants in wine and tea.
PMID- 10692896
TI - Transport and temperature effects on blood potassium.
PMID- 10692897
TI - Transport and temperature effects on blood potassium
PMID- 10692898
TI - Infections prevent the development of asthma--true, false or both?
PMID- 10692899
TI - Multicentre research ethics committees: have they helped?
PMID- 10692900
TI - Replacement of damaged neural cells: a mirage?
PMID- 10692901
TI - Renal artery stenosis as a cause of renal impairment: implications for treatment
of hypertension and congestive heart failure.
PMID- 10692902
TI - Placebos and placebo effects in medicine: historical overview.
PMID- 10692903
TI - Management of acute bursitis: outcome study of a structured approach.
AB - In patients with septic bursitis the indications for admission and surgical
intervention remain unclear, and practice has varied widely. The effectiveness of
a conservative outpatient based approach was assessed by an outcome study in a
prospective case series. Consecutive patients attending an emergency department
with acute swelling of the olecranon or prepatellar bursa were managed according
to a structured approach, subjective and objective outcomes being assessed after
two to three days, and subsequently as required until clinical discharge. Long
term outcomes were assessed by telephone follow-up for up to eighteen months. 47
patients were included in the study: 22 had septic bursitis, 15 of the olecranon
bursa and 7 of the prepatellar bursa. The mean visual analogue pain scores of
those with septic bursitis improved from 4.8 at presentation to 1.7 at first
follow-up for olecranon bursitis, and from 3.8 to 2.7 for prepatellar bursitis.
Symptoms improved more slowly for patients with non-septic bursitis. No patients
were admitted initially, but 2 were admitted (two days each) after the first
follow-up appointment. One patient had incision and drainage on the third
attendance, and 3 patients developed discharging sinuses, which all healed
spontaneously. All patients made a good long-term symptomatic recovery and all
could lean on the elbow or kneel by the end of the follow-up period. The
management protocol, with specific criteria for admission and surgical
intervention, thus produced good results with little need for operation or
admission.
PMID- 10692904
TI - Switching to statins: a challenge for primary care.
AB - In 1997, doctors in England received official guidelines on the use of statins (3
hydroxy-3-methylglutaryl coenzyme A inhibitors) for primary and secondary
prevention of coronary heart disease (CHD). Six months later we determined the
status of patients who had been discharged from a specialist lipid clinic in
1989. 195 patients received questionnaires, with the consent of their general
practitioners, regarding morbidity in, the subsequent decade and present
medication, and were asked to have their cholesterol checked. Analysis was
confined to the 86 with a current cholesterol measurement. Of 61 patients who had
been discharged on a regimen of dietary advice and/or medication for primary
prevention of CHD, 8 had been changed to a statin and 6 had been started on one.
According to the new guidelines, none of these qualified for treatment. Of 25
patients who had been discharged on drugs for secondary prevention, all qualified
for a statin but only 14 were receiving one--in 6 cases without achieving the
recommended reductions in cholesterol. In many of the patients reviewed,
treatment had not been altered to conform with the new guidelines. If
hyperlipidaemic patients are to benefit promptly from advances in treatment, one
solution might be a central registry that arranged regular tests and reported
back to general practitioners. However, since many patients at risk do not have
very high cholesterol levels, a coordinated approach to CHD risk factors would be
preferable.
PMID- 10692905
TI - Family support in general practice.
AB - At a time when social services are overburdened in Britain, family support in
general practice offers one way to fill the gap. In the Well Family Project, a
'family support coordinator' worked within a general practice in Hackney, London.
In the first eighteen months she saw 113 clients. Evaluation was by
semistructured interviews with a sample of these clients and with professional
workers. Comments from those interviewed indicate that the family support was
valued. The general practice base was convenient and non-stigmatizing. By
adopting a proactive approach, the project was able to work with clients who had
previously 'slipped through the net'. Some of the professionals interviewed would
have liked to provide the same help, but were unable to do so because of time and
other constraints. Family support provided through general practice was well
received by vulnerable families. Although there was overlap with the remit of
health visitors and social workers, the protected time and the independence of
the coordinator enabled clients to obtain the help they wanted. The replicability
of this strategy now needs to be assessed.
PMID- 10692906
TI - Severe parkinsonism secondary to carbon monoxide poisoning.
PMID- 10692907
TI - Excision of a false left ventricular aneurysm.
PMID- 10692908
TI - Heart valve disease in seronegative rheumatoid arthritis.
PMID- 10692909
TI - Splenic perivascular fibrosis as an ultrasound finding.
PMID- 10692910
TI - The English inoculator: Jan Ingen-Housz.
PMID- 10692911
TI - Some unanswered questions about NICE.
PMID- 10692912
TI - Tiger bites.
PMID- 10692913
TI - Antenatal screening for HIV.
PMID- 10692914
TI - Coeliac disease in adults.
PMID- 10692915
TI - Euthanasia in the Netherlands.
PMID- 10692916
TI - Adverse reactions to herbal treatment.
PMID- 10692917
TI - Autoimmune enteropathy with goblet cell antibodies.
PMID- 10692918
TI - Contralateral extradural haematoma after ventriculoperitoneal shunt insertion.
PMID- 10692919
TI - A Harley Street address
PMID- 10692920
TI - Management of penile fracture.
PMID- 10692921
TI - Glaucoma surgery in the United Kingdom: why, who and when.
PMID- 10692922
TI - Can altering the pattern of laser photocoagulation for proliferative diabetic
retinopathy help retain visual fields for driving?
PMID- 10692923
TI - Bowman Lecture 1998. Diabetic retinopathy: some cellular, molecular and
therapeutic considerations.
PMID- 10692924
TI - The National Survey of Trabeculectomy. I. Sample and methods.
AB - PURPOSE: The National Survey of Trabeculectomy was designed to evaluate current
practices of glaucoma surgery in the United Kingdom and to determine the success
and complication rates of trabeculectomy on a national basis. This paper reports
the survey methods, levels of consultant activity, waiting times, indications for
surgery and the demographic and clinical characteristics of the patient sample.
METHODS: Consultant ophthalmologists performing trabeculectomy in the United
Kingdom were studied. Four consecutive patients undergoing trabeculectomy under
each consultant prior to 18 June 1996 were retrospectively sampled. Patients were
followed prospectively and evaluated 6 and 12 months after surgery. Data were
collected by self-administered postal questionnaires. To determine the effects of
selection and reporting bias a validation study of 14 randomly selected units was
also conducted. RESULTS: Three hundred and eighty-two consultants recruited 1454
eligible patients for analysis. The mean age of patients was 69.2 years (standard
deviation 10.9) and 51.7% were male. The underlying diagnosis was primary open
angle glaucoma in 89.2%, pseudoexfoliation glaucoma in 5.4%, normal tension
glaucoma in 3.8% and pigmentary glaucoma in 1.6%. There was advanced visual field
damage in 50.5% of the cohort by the time of listing. The main indications for
surgery were failure of medication to control intraocular pressure in 57.1%,
progressive visual field loss in 26.5% and progressive optic disc damage in 4.8%.
Primary surgery was undertaken in 4.8% of patients. In 80% trabeculectomy was
performed within 3 months of listing. However, almost a third of consultants
considered individual patient's waiting time too long. Validation studies
confirmed that systematic bias did not operate in the selection of patients for
the survey or in the reporting of outcomes. CONCLUSION: The findings of this
survey are representative of current practices of trabeculectomy by consultants
throughout the United Kingdom and show considerable variation in practice.
Failure to control intraocular pressure with topical medications was the main
indication for surgery. Advanced glaucomatous visual field damage was present at
the time of surgery in half the sample. Though most patients were operated on
within 3 months of listing, almost a third of consultants considered the wait
unacceptably long.
PMID- 10692925
TI - Altering the pattern of panretinal photocoagulation: could the visual field for
driving be preserved?
AB - PURPOSE: To identify the area of retina required to provide the visual field for
driving and to investigate whether the pattern of panretinal photocoagulation
(PRP) for proliferative diabetic retinopathy could be altered to avoid treatment
in this area whilst leaving the total number of burns constant. METHODS: A
mathematical model of the emmetropic eye is used to calculate retinal dimensions
corresponding to different angles of visual field. These are used to define
retinal regions that correspond to the UK DVLC visual field criteria and regions
that lie outside this area. Further calculation estimates the number of laser
burns applied within these regions for both 500 microns and 200 microns diameter
spot sizes and various burn spacings. RESULTS: Modelling of the number of burns
applied in the normal pattern of PRP agrees with the number required to control
proliferative retinopathy. Reducing burn spacing or extending treatment up to the
ora serrata allows application of sufficient burns to control the disease without
encroaching on areas of the retina that provide the driving field. CONCLUSION: It
is theoretically possible to alter the pattern of PRP to avoid treatment in
retinal areas concerned with the driving visual field whilst leaving the total
number of burns constant. This suggests that a clinical trial of such a pattern
PRP could be performed to assess adequate control of proliferative retinopathy
along with preservation of the visual field required for driving.
PMID- 10692926
TI - Low-dose midazolam infusion for oculoplastic surgery under local anesthesia.
AB - PURPOSE: Oculoplastic surgery with infiltration of local anaesthesia at the
operative site performed as a day-case procedure is both efficient and cost
effective. Patients considered unsuitable for this because of fear or
apprehension may, however, benefit from per-operative conscious sedation. We
sought to study the efficacy and safety of this using midazolam, a water-soluble
benzodiazepine. METHOD: We have performed a controlled clinical trial comparing
the effect of a low-dose intravenous infusion of midazolam (0.2 mg/ml of normal
saline at a rate of 1 mg/h) with saline placebo on 48 subjects undergoing
oculoplastic surgery with local anaesthesia. Patients were given pre- and post
operative questionnaires assessing, amongst other factors, anxiety levels, pain,
degree of reported amnesia and psychomotor recovery. RESULTS: Using the low-dose
midazolam infusion no adverse cardiorespiratory reactions occurred. Patients
receiving midazolam reported remembering significantly less about their operation
than controls (p = 0.04) and showed significantly lower state-anxiety after their
operation than before (p < 0.02). This change was not noted in the placebo group.
There was no significant difference in the psychomotor performance of patients
given midazolam compared with controls 2 h after surgery. CONCLUSIONS: A low-dose
continuous infusion of midazolam can be used to safely provide effective
anxiolysis and conscious sedation with good psychomotor recovery during
oculoplastic procedures in a day-case setting.
PMID- 10692927
TI - Missed orbital wall blow-out fracture as a cause of post-enucleation socket
syndrome.
AB - BACKGROUND: Post-enucleation socket syndrome (PESS: deep upper lid sulcus, ptosis
or upper lid retraction, enophthalmos and lower lid laxity) is a well-recognised
complication of a volume-deficient anophthalmic socket. A patient requiring
enucleation following severe ocular trauma may have an underlying orbital wall
blow-out fracture which if overlooked can cause severe volume deficit with poor
cosmesis and limited prosthesis motility. PURPOSE: To establish the prevalence of
an undiagnosed blow-out fracture in patients with PESS and a history of relevant
trauma. METHODS: Medical records and orbital computed tomography (CT) scans were
reviewed for all patients presenting with PESS and a history of relevant trauma.
RESULTS: Undiagnosed blow-out fractures were found in 15 (33%) of 45 patients
presenting between August 1993 and December 1996. These were significant enough
to warrant surgical repair in 13 (29%) patients. CONCLUSIONS: We suggest that any
patient presenting with PESS and a history of relevant trauma should be
considered to have an orbital wall blow-out fracture until proven otherwise by CT
scanning of the orbit. Similarly any patient requiring enucleation following
severe ocular trauma should undergo CT scanning to rule out a coexisting blow-out
fracture which could be repaired at the time of enucleation.
PMID- 10692928
TI - Corneal biopsy with tissue micro-homogenisation for isolation of organisms in
bacterial keratitis.
AB - PURPOSE: To evaluate a novel two-stage technique to increase yield of bacteria
isolated from infected corneal ulcers. METHODS: A new blade was designed to
remove friable material from infected corneal ulcers. The new blade was used in
combination with standard tissue micro-homogenisation equipment in a two-stage
technique intended to distribute biopsy samples evenly between relevant agar
plates. Patients with presumed-bacterial corneal ulcers underwent sequential
corneal sampling using the new two-stage technique and a scalpel blade, used
without micro-homogenisation (the order of sampling was varied between two
groups). Bacterial isolation rates were compared using the chi-squared test.
RESULTS: Twenty-four patients with presumed-bacterial corneal ulcers were
studied. The overall positive bacterial isolation rate was 88%, with identical
bacterial isolation rates for the new two-stage technique and the scalpel blade
(71%). The new technique isolated bacteria from three ulcers that had initially
been 'sterile' when sampled with a scalpel blade. Polymicrobial infections were
identified in two ulcers with the new blade where only a single organism had been
identified using the scalpel blade (not significantly different). CONCLUSIONS:
The new two-stage technique shows promise for improving bacterial isolation rates
from presumed-bacterial corneal ulcers.
PMID- 10692929
TI - Corneal topography in patients with congenital ptosis.
AB - PURPOSE: To determine the effect of congenital ptosis on corneal shape, and to
assess the role of these topographic changes in the development of amblyopia.
METHODS: Twenty-two patients with congenital ptosis were examined and a corneal
topographic examination performed in both the ptotic and normal eyes. The
qualitative corneal classification was done according to the colour-coded
topographic maps. The surface regularity index (SRI) and the surface asymmetry
index (SAI) were used as quantitative descriptors of the study. RESULTS: Ptotic
eyes had an increased incidence of astigmatism, bow tie pattern on corneal
topography, corneal asymmetry (SAI, p < 0.05) and corneal irregularity (SRI, p <
0.05). Lack of mirror-image symmetry with the fellow eye was higher in amblyopic
eyes. CONCLUSION: Eyes with congenital ptosis have an increased incidence of
astigmatism and a bow tie pattern on corneal topography. These features are
associated with the presence of amblyopia.
PMID- 10692931
TI - Per-operative retinoscopy as a predictor of final post-operative refraction.
AB - PURPOSE: To assess the accuracy of streak retinoscopy performed at the end of
cataract surgery as a predictor of final post-operative error. METHOD:
Retinoscopy was performed on 68 patients as they lay on the operating table after
routine cataract extraction and intraocular lens implantation. In each case the
predicted post-operative refraction by biometry and the retinoscopy at the end of
the operation were compared with the 6 week post-operative subjective refraction.
RESULTS: The retinoscopy had a mean difference of 0.6 D (standard deviation of
0.5 D). The post-operative refraction predicted by biometric measurements had a
mean difference of 1.6 D (standard deviation 0.6 D). When corrected for
systematic error, 8% of patients were found to have an error of greater than 2 D
as predicted by pre-operative biometry. Prediction by retinoscopy made no error
greater than 2 D. The accuracy in the retinoscopic prediction of post-operative
refraction was significantly better than the biometry using the F-test (p =
0.001). CONCLUSION: Retinoscopy at the end of cataract surgery may be a valuable
tool to alert the surgeon to an unexpected refractive error. This would enable
immediate intraocular lens exchange, if required.
PMID- 10692930
TI - Human aqueous and vitreous humour levels of ciprofloxacin following oral and
topical administration.
AB - PURPOSE: To assess aqueous and vitreous humour ciprofloxacin concentrations
following oral and topical administration of ciprofloxacin in patients with non
inflamed cornea and an intact crystalline lens, and to compare the concentrations
of the drug given by either route. METHODS: In this prospective study, 34
patients undergoing pars plana vitrectomy for various ocular pathologies were
divided into two groups. Eighteen patients received 2 drops of 0.3% ophthalmic
solution of ciprofloxacin every 30 min for 3 h and then every 60 min for the next
3 h, and 16 patients received a single oral dose of 1000 mg ciprofloxacin 6 h
before surgery. The aqueous and vitreous humour samples were simultaneously
harvested after oral or topical administration during pars plana vitrectomy to
assess penetration of the drug. These samples were assayed for ciprofloxacin
concentrations by a method described previously by us using high-performance
liquid chromatography. RESULTS: The aqueous and vitreous humour levels of
ciprofloxacin were 0.59 +/- 0.06 microgram/ml (mean +/- SEM) and 0.64 +/- 0.06
microgram/ml after oral and 0.44 +/- 0.07 microgram/ml and 0.22 +/- 0.04
microgram/ml after topical ciprofloxacin administration, respectively. Aqueous
humour levels were not statistically significantly different following oral and
topical administration (p = 0.069). However, the vitreous level of the drug after
oral administration was significantly higher than that after topical
administration (p < 0.001). CONCLUSION: Ocular bioavailability of ciprofloxacin
in aqueous humour following oral and topical administration is found to be
similar when the drug was applied as described above. Penetration of
ciprofloxacin into vitreous humour is less than that into aqueous humour after
topical administration.
PMID- 10692932
TI - Predictive value of family data for the management of infantile bilateral partial
cataract.
AB - PURPOSE: To examine the data on outcome of surgery performed over a wide age
range in members of a family affected by familial infantile bilateral partial
cataract, with the purpose of assessing their predictive value concerning the
timing of surgery. METHODS: A retrospective clinical study was carried out of a
family with dominant inheritance of familial infantile bilateral partial
cataract. The family spanned four generations and consisted of 53 members, 31 of
whom were examined in our department. Of these, 18 were affected. Cataract
surgery was performed in 26 eyes of 15 patients, whose ages ranged from 6 to 58
years at the time of operation. As the surgical procedures spanned the years from
1978 to 1996, different techniques were used. RESULTS: In 24 eyes (92%) the post
operative visual acuity was 6/9 or better. One eye achieved 6/12 and another
6/15. CONCLUSIONS: In this particular family there was no relationship between
the post-operative visual acuity and the age at which surgery was performed. In
deciding when to operate on family members with infantile bilateral partial
cataract with similar morphology, in addition to the commonly used criteria the
family data should also be taken into account. In infants and young children,
delaying surgery may allow better development of visual acuity aided by
accommodation, stabilisation of binocularity and more precise determination of
the power of an intraocular lens. Success of very early surgery in such cases may
not be attributable to the timing of the operation.
PMID- 10692933
TI - The results of adjustable suture technique in paediatric strabismus surgery.
AB - PURPOSE: Adjustable suture technique (AST) has been shown to be an effective
treatment method in adult strabismus. The application of AST is not well studied
in children due to potential poor cooperation during adjustment and the concern
that the adjustment process can not be completed. The present series evaluates
the efficacy and safety of this technique in a preselected group of children
between 7 and 15 years of age. METHODS: A retrospective review of 89 consecutive
children undergoing AST was completed to assess: (1) the ability to perform and
complete adjustment in children; (2) the frequency of need to perform adjustment;
and (3) accuracy of surgical alignment. Only patients with horizontal rectus
muscle surgery were included. RESULTS: All children successfully completed the
AST on the first post-operative day. Of the 89 patients, 24 (27%) required
further adjustment by the AST. The mean follow-up period was 13.1 months. Fifty
three patients (60%) had previous strabismus surgery (range 1 to 5 operations).
Sixty-six (74%) patients achieved successful alignment. Complications included
slipped muscles in 1 case and difficulty in recession of the lateral rectus
muscle in 1 patient. CONCLUSIONS: Twenty-seven per cent of the patients required
post-operative adjustment. The AST achieved an overall 74% successful alignment.
Application of the AST should be considered in children with horizontal
deviations over age 7 years, especially in the reoperations of esotropia.
PMID- 10692934
TI - Transscleral diode laser in the treatment of retinopathy of prematurity.
AB - PURPOSE: To assess the outcome of contact transscleral diode laser (TSDL) in the
treatment of threshold retinopathy of prematurity (ROP). METHOD: TSDL was
performed in 14 eyes of 8 babies who presented to the paediatric ophthalmic
service at King's College Hospital between 1996 and 1997 with threshold ROP
(median post-conceptual age 26 + 1 weeks, median birthweight 835 g) by a single
surgeon. Follow-up ranged from 9 to 41 weeks (median 21 weeks). RESULTS: In 11
eyes (79%) regression of ROP occurred after a single laser treatment with a good
anatomical outcome. In 3 eyes (21%) there was an unfavourable response with the
development of traction retinal detachment. These include both eyes of one baby
who rapidly progressed to stage IV ROP. One other eye developed a fibrotic band a
few months after treatment. No significant complications of laser treatment were
observed. CONCLUSION: These initial results indicate that TSDL photocoagulation
is an effective and technically straightforward alternative to cryotherapy in the
treatment of ROP.
PMID- 10692935
TI - Blue light induced apoptosis in rat retina.
AB - PURPOSE: To explore cell death in blue light induced retinal damage. METHODS:
Sprague-Dawley rats reared under cyclic light were exposed continuously to
diffuse blue light (400-480 nm) at 0.64 W/m2 for 3 or 6 h after 22 h of dark
adaptation. The rats were kept in darkness and killed immediately, 8, 16 and 24 h
following light exposure. The retinal damage by the blue light was examined with
a transmission electron microscope. The cell death was characterised by in situ
terminal dUTP nick end labelling (TUNEL) and gel electrophoresis. RESULTS: During
the 24 h following light exposure, photoreceptor cell death was characterised by
progressive condensation and margination of the chromatin, shrinkage or
convolution and fragmentation of the nucleus, condensation of the cytoplasm, and
formation of apoptotic bodies along with rapid removal of dying cells from
damaged areas in the absence of inflammatory response. The TUNEL-positive nuclei
were scattered individually in the outer nuclear layer just after light exposure.
A wave of massive TUNEL labelling of photoreceptor nuclei peaked at 8-16 h and
dropped at 24 h following light exposure. The distribution of TUNEL-positive
nuclei was located predominantly at the upper temporal region of the retina,
which was the most sensitive area to the damage caused by blue light.
Furthermore, the multiples of internucleosomal cleavage of 180-200 base pairs
were demonstrated at corresponding time points. CONCLUSION: Photoreceptor cell
apoptosis is seen early after the retina is damaged by blue light.
PMID- 10692936
TI - The use of combined intravenous pulse methylprednisolone and low-dose oral
cyclosporin A in the treatment of corneal graft rejection: addendum to previous
report.
PMID- 10692937
TI - Hypopyon keratitis in corneal epithelial basement membrane dystrophy.
PMID- 10692938
TI - Bilateral keratomalacia in a cachectic scleroderma patient.
PMID- 10692939
TI - Acanthamoeba keratitis following optical keratoplasty.
PMID- 10692940
TI - Mucocele arising from a lateral extension of a sphenoid sinus.
PMID- 10692941
TI - Aberrant lacrimal gland within the tarsal plate presenting as hyperlacrimation.
PMID- 10692942
TI - Desmoplastic trichilemmoma of the upper eyelid.
PMID- 10692943
TI - An unusual chorioretinal dystrophy?
PMID- 10692944
TI - Mitochondrial DNA disease masquerading as age-related mascular degeneration.
PMID- 10692945
TI - Candida endophthalmitis: a diagnostic dilemma.
PMID- 10692946
TI - Ocular Munchausen syndrome characterised by self-introduction of chalk
concretions into the conjunctival fornix.
PMID- 10692947
TI - An unusual presentation of Graves' disease.
PMID- 10692948
TI - Assessment of choroidal involvement in sarcoidosis with indocyanine green
angiography.
PMID- 10692949
TI - Intravitreal penetration of teicoplanin.
PMID- 10692950
TI - Primary empty sella: cause of visual failure or chance association?
PMID- 10692951
TI - Glaucoma screening by optometrists: positive predictive value of visual field
testing.
PMID- 10692952
TI - Post-operative myopic shift due to trapped intracapsular Healon.
PMID- 10692953
TI - Challenges to public health in the new millennium.
PMID- 10692954
TI - Drinking water and gastrointestinal disease: need of better understanding and an
improvement in public health surveillance.
PMID- 10692955
TI - The unseen face of humanitarian crisis in eastern Democratic Republic of Congo:
was nutritional relief properly targeted?
AB - STUDY OBJECTIVE: Comparison of children's nutritional status in refugee
populations with that of local host populations, one year after outbreak refugee
crisis in the North Kivu region of Democratic Republic of Congo. DESIGN: Cross
sectional surveys. SETTING: Temporary and other settlements, in the town of Goma
and surrounding rural areas. SUBJECTS: Anthropometric indicators of nutritional
status and presence or absence of oedema were measured among 5121 children aged 6
to 59 months recruited by cluster sampling with probability proportional to size,
between June and August 1995. RESULTS: Children in all locations demonstrated a
typical pattern of growth deficit relative to international reference. Prevalence
of acute malnutrition (wt/ht < -2 Z score) was higher among children in the rural
non-refugee populations (3.8 and 5.8%) than among those in the urban non-refugee
populations (1.4%) or in the refugee population living in temporary settlements
(1.7%). Presence of oedema was scarcely noticed in camps (0.4%) while it was a
common observation at least in the most remote rural areas (10.1%). As compared
with baseline data collected in 1989, there is evidence that nutritional status
was worsening in rural non-refugee populations. CONCLUSIONS: Children living in
the main town or in the refugee camps benefited the most from nutritional relief
while those in the rural non-refugee areas were ignored. This is a worrying case
of inequity in nutritional relief.
PMID- 10692956
TI - Women in hospital medicine in the United Kingdom: glass ceiling, preference,
prejudice or cohort effect?
AB - OBJECTIVE: To assess from official statistics whether there is evidence that the
careers of women doctors in hospitals do not progress in the same way as those of
men. DESIGN: The proportions of female hospital doctors overall (1963-96), and in
the specialties of medicine, surgery, obstetrics and gynaecology, pathology,
radiology/radiotherapy, anaesthetics and psychiatry (1974-1996) were examined.
Additionally data were examined on career preferences and intentions from pre
registration house officers, final year medical students, and medical school
applicants (1966-1991). ANALYSIS: Data were analysed according to cohort of entry
to medical school to assess the extent of disproportionate promotion. RESULTS:
The proportion of women in hospital career posts was largely explained by the
rapidly increasing proportion of women entering medical school during the past
three decades. In general there was little evidence for disproportionate
promotion of women in hospital careers, although in surgery, hospital medicine
and obstetrics and gynaecology, fewer women seemed to progress beyond the SHO
grade, and in anaesthetics there were deficits of women at each career stage.
Analyses of career preferences and intentions suggest that disproportionate
promotion cannot readily be explained as differential choice by women.
CONCLUSIONS: Although there is no evidence as such of a "glass ceiling" for women
doctors in hospital careers, and the current paucity of women consultants
primarily reflects historical trends in the numbers of women entering medical
school, there is evidence in some cases of disproportionate promotion that is
best interpreted as direct or indirect discrimination.
PMID- 10692957
TI - Nutrient intakes during pregnancy: the influence of smoking status and age.
AB - STUDY OBJECTIVE: To examine the relation of antioxidant and other nutrient
intakes in pregnancy to smoking and sociodemographic variables. DESIGN: Cohort
study. SETTING: St Mary's Maternity Hospital, Portsmouth. PARTICIPANTS: Pregnant
nulliparous women, with no existing complications of pregnancy, were recruited
from antenatal booking clinics. A total of 774 women completed seven day food
diaries, and supplied detailed data on their use of nutrient supplements. MAIN
RESULTS: Smokers had lower intakes of most micronutrients. After adjustment for
the confounding effects of maternal age, height, and education, only vitamin C
and carotenoid intakes remained significantly depressed. Age was strongly and
significantly associated with the intake of most nutrients, including
antioxidants, and this association was independent of other maternal factors.
Antioxidant intake was therefore lowest in young women who smoked: for example
smokers under 24 years had a mean vitamin C intake of 57 mg (SD 35) compared with
106 mg (SD 52) for non-smokers aged 28 and over (difference 49 mg, 95% CI 39,
59). The corresponding intakes of carotenoid equivalents were 1335 micrograms (SD
982) and 2093 micrograms (SD 1283) (difference 758 micrograms, 95% CI 496, 1020).
CONCLUSIONS: The study has identified, for the first time, young pregnant women
as a group at particular risk of low micronutrient intake. The health
implications of poor nutrition now need to be evaluated, particularly for those
women who smoke.
PMID- 10692958
TI - Social inequalities in health related behaviours in Barcelona.
AB - OBJECTIVE: This study describes social class inequalities in health related
behaviours (tobacco and alcohol consumption, physical activity) among a sample of
general population over 14 years old in Barcelona. DESIGN: Cross sectional study
(Barcelona Health Interview Survey). SETTING: Barcelona city (Spain).
PARTICIPANTS: A representative stratified sample of the non-institutionalised
population resident in Barcelona was obtained. This study refers to the 4171
respondents aged over 14. DATA: Social class was obtained from a Spanish
adaptation of the British Registrar General classification. In addition,
sociodemographic variables such as family structure and employment status were
used. As health related behaviours tobacco consumption, alcohol consumption,
usual physical activity and leisure time physical activity were analysed. Age
adjusted percentages were compared by social class. Multivariate analysis was
performed using logistic regression models. MAIN RESULTS: Women in the upper
social classes were more likely to smoke, the adjusted odds ratio (OR) for social
class V in reference to social class I was 0.36 (95% confidence intervals
(95%CI): 0.19, 0.67), while the opposite occurred among men although it was not
statistically significant in multivariate analysis. Smoking cessation was more
likely among men in the higher classes (OR for class V 0.41, 95%CI: 0.18, 0.90).
Excessive alcohol consumption among men showed no differences between classes,
while among women it was greater in the upper classes. Engaging in usual physical
activity classified as "light or none" in men decreased with lowering social
class (OR class IVa: 0.55 and OR class IVb: 0.47). Women of social classes IV and
V were less likely to have two or more health risk behaviours (OR for class V
0.33, 95% CI: 0.18, 0.62). CONCLUSION: Health damaging behaviours are
differentially distributed among social classes in Barcelona. Health policies
should take into account these inequalities.
PMID- 10692959
TI - Homocysteine, folate, vitamin B12, and cardiovascular risk in Indians, Malays,
and Chinese in Singapore.
AB - OBJECTIVE: To examine the hypothesis that the higher rates of coronary heart
disease (CHD) in Indians (South Asians) compared with Malays and Chinese is
partly attributable to differences in blood concentrations of homocysteine, and
related blood concentrations of folate and vitamin B12. DESIGN: Cross sectional
study of the general population. SETTING: Singapore. PARTICIPANTS: Random sample
of 726 fasting subjects aged 30 to 69 years. MAIN RESULTS: Mean plasma total
homocysteine concentrations did not show significant ethnic differences; values
were Indians (men 16.2 and women 11.5 mumol/l), Malays (men 15.0 and women 12.5
mumol/l), and Chinese (men 15.3 and women 12.2 mumol/l). Similarly, the
proportions with high plasma homocysteine (> 14.0 mumol/l) showed no important
ethnic differences being, Indians (men 60.0 and women 21.9%), Malays (men 53.9
and women 37.8%), and Chinese (men 56.6 and women 30.6%). Mean plasma folate
concentrations were lower in Indians (men 8.7 and women 10.9 nmol/l) and Malays
(men 8.5 and women 10.8 nmol/l), than Chinese (men 9.7 and women 13.8 nmol/l).
Similarly, the proportions with low plasma folate (< 6.8 nmol/l) were higher in
Indians (men 44.9 and women 36.6%) and Malays (men 45.3 and women 24.5%) than
Chinese (men 31.4 and women 12.6%). Mean plasma vitamin B12 concentrations were
lowest in Indians (men 352.5 and women 350.7 pmol/l), then Chinese (men 371.1 and
women 373.7 pmol/l), and then Malays (men 430.5 and women 486.0 pmol/l).
CONCLUSION: While there were ethnic differences for plasma folate and vitamin B12
(in particular lower levels in Indians), there was no evidence that homocysteine
plays any part in the differential ethnic risk from CHD in Singapore and in
particular the increased susceptibility of Indians to the disease.
PMID- 10692960
TI - Impairments, disabilities and needs assessment among non-fatal war injuries in
south Lebanon, Grapes of Wrath, 1996.
AB - STUDY OBJECTIVE: To examine the impact of non-fatal war related injuries on
physical disability in a group of war wounded civilians and to assess their
needs. DESIGN: Cross sectional study. Home interviews were conducted using a
structured interview schedule around one month after the injury, to assess
impairments, disabilities, and needs. STUDY POPULATION AND SETTING: War wounded
persons in towns and villages in South Lebanon during the attack "Grapes of
Wrath" in 1996. RESULTS: The majority of the study population were young and in
their productive age, mostly injured in the street or while hiding in open
shelters. Around half of the injuries resulted in impairments, but, there were no
age, gender or geographical differentials by severity of impairment. Almost one
third (29%) of the students enrolled in schools at the time of the injury
reported failure to continue their education and 42% of the working members lost
their jobs with no potential for 34% of them to resume their former jobs. The
impact of the injury on impairments, motor disabilities and physical independence
was highest for injuries to the lower limbs (age and sex adjusted risk ratio (RR)
1.62, 95% confidence intervals (CI) 1.25, 2.10; 2.98, 95% CI 2.09, 4.23; and
2.13, 95% CI 1.39, 3.27, respectively). Despite the acute and early relief
services provided by all those concerned at the time of the injury, when asked
about unmet needs, the majority of the impaired (66%) reported the need for
additional services, mostly medical in nature. The degree of disability was a
salient factor for the need for rehabilitative services but not for medical
services. CONCLUSIONS: The chronic and diverse needs of people with war injuries
are often neglected and underestimated by the governmental institutions and
relief agencies. Research funds as well as services should be allocated to tackle
the long term and continuous health and social needs of those injured and their
families.
PMID- 10692961
TI - Empowering the deaf. Let the deaf be deaf.
AB - Deafness is often regarded as just a one and only phenomenon. Accordingly, deaf
people are pictured as a unified body of people who share a single problem. From
a medical point of view, we find it usual to work with a classification of
deafness in which pathologies attributable to an inner ear disorder are
segregated from pathologies attributable to an outer/middle ear disorder. Medical
intervention is thus concerned more with the origin, degree, type of loss, onset,
and structural pathology of deafness than with communicative disability and the
implications there may be for the patient (mainly dependency, denial of abnormal
hearing behaviour, low self esteem, rejection of the prosthetic help, and the
breakdown of social relationships). In this paper, we argue that hearing loss is
a very complex phenomenon, which has many and serious consequences for people and
involves many factors and issues that should be carefully examined. The immediate
consequence of deafness is a breakdown in communication whereby the communicative
function needs to be either initiated or restored. In that sense, empowering
strategies--aimed at promoting not only a more traditional psychological
empowerment but also a community one--should primarily focus on the removal of
communication barriers.
PMID- 10692962
TI - Drinking water turbidity and gastrointestinal illness in the elderly of
Philadelphia.
AB - STUDY OBJECTIVE: To investigate the association between drinking water quality
and gastrointestinal illness in the elderly of Philadelphia. DESIGN: Within the
general population, children and the elderly are at highest risk for
gastrointestinal disease. This study investigates the potential association
between daily fluctuations in drinking water turbidity and subsequent hospital
admissions for gastrointestinal illness of elderly persons, controlling for time
trends, seasonal patterns, and temperature using Poisson regression analysis.
SETTING AND PARTICIPANTS: All residents of Philadelphia aged 65 and older in 1992
1993 were studied through their MEDICARE records. MAIN RESULTS: For
Philadelphia's population aged 65 and older, we found water quality 9 to 11 days
before the visit was associated with hospital admissions for gastrointestinal
illness, with an interquartile range increase in turbidity being associated with
a 9% increase (95% CI 5.3%, 12.7%). In the Belmont service area, there was also
an association evident at a lag of 4 to 6 days (9.1% increase, 95% CI 5.2, 13.3).
Both associations were stronger in those over 75 than in the population aged 65
74. This association occurred in a filtered water supply in compliance with US
standards. CONCLUSIONS: Elderly residents of Philadelphia remain at risk of
waterborne gastrointestinal illness under current water treatment practices.
Hospitalisations represent a very small percentage of total morbidity.
PMID- 10692963
TI - The Communicable Disease Surveillance System in the Kosovar refugee camps in the
former Yugoslav Republic of Macedonia April-August 1999.
PMID- 10692964
TI - Morbidity and health care utilisation among elderly people in Mmankgodi village,
Botswana.
AB - OBJECTIVE: To evaluate the health status among the elderly in a village in
Botswana and their pattern of health care utilisation. DESIGN: A descriptive
study where all persons 60 years and older were invited to participate, including
a medical examination, laboratory testing and a questionnaire aiming at gathering
sociodemographic data. SETTING: Mmankgodi village of Botswana. SUBJECTS: 419
persons were identified as elderly in the village, out of which 337 were
included. MAIN OUTCOME MEASURES: The general medical examination also included
eye status, vision and hearing tests, nutritional status, blood pressure and
registering of physical disabilities. Laboratory tests included haemoglobin,
blood glucose, HIV antibodies and serum lipids. The questionnaire contained
questions regarding family and civil status, self assessed general health, health
problems experienced during the previous month, and health care utilisation.
Questions also pertained to smoking, taking snuff, and alcohol consumption.
RESULTS: A majority (75%) of the elderly experienced good or only somewhat
reduced health, while one quarter suffered more serious health problems. The most
frequent health problems were related to the musculoskeletal system. Eye
diseases, including cataract and blindness, were also common. The concentration
of serum lipids is lower than the one found in the elderly population of Norway.
Nutritional status indicated a relatively high prevalence (7%) of malnutrition.
The majority of men were still married (87%), while most women were widowed
(71%). Women reported more health problems than men, and they also reported more
worries regarding their own life situation. There is a tendency for the elderly
to seek assistance from the established clinics and other health facilities for
their health problems. Worries are either kept to themselves or advice is sought
from relatives. Traditional healers were not often consulted for health problems
or worries. CONCLUSIONS: Major health problems were identified among the elderly
in this geographical area of Botswana. There is presently no health programme in
Botswana aimed at the elderly. Some of the diseases and conditions found in this
study could easily be identified and treated in the present health system through
a health care programme.
PMID- 10692965
TI - How does tuberculosis relate to HIV positive and HIV negative drug users?
AB - OBJECTIVES: (1) To compare the incidence of active tuberculosis in HIV positive
and HIV negative drug users. (2) To describe the main characteristics of the
tuberculosis cases. DESIGN: A prospective study was performed from 1986 to 1996
as part of an ongoing cohort study of HIV infection in Amsterdam drug users.
METHODS: Data from the cohort study, including HIV serostatus and CD4-cell
numbers, were completed with data from the tuberculosis registration of the
tuberculosis department of the Amsterdam Municipal Health Service. Analyses were
carried out with person time and survival methods. RESULTS: Of 872 participants,
24 persons developed culture confirmed tuberculosis during a total follow up
period of 4000 person years (0.60 per 100 py, 95% CI: 0.40, 0.90). Nineteen cases
were HIV positive (1.54 per 100 py, 95% CI: 0.86, 2.11) and five HIV negative
(0.18 per 100 py, 95% CI: 0.08, 0.43). Multivariately HIV infection (relative
risk: 12.9; 95% CI: 3.4, 48.8) and age above 33 years (RR: 6.8; 95% CI: 1.3,
35.0, as compared with age below 27) increased the risk for tuberculosis
substantially. Additional findings were: (1) 13 of 22 pulmonary tuberculosis
cases (59%) were detected by half yearly radiographic screening of the chest; (2)
tuberculosis occurred relatively early in the course of HIV infection at a mean
CD4 cell number of 390/microliter; (3) an estimated two thirds of the incidence
of tuberculosis observed among HIV positive cases was caused by reactivation; (4)
all but one patient completed the tuberculosis treatment. CONCLUSION: HIV
infection increases the risk for active tuberculosis in Amsterdam drug users 13
fold. The incidence of tuberculosis in HIV negative drug users is still six times
higher than in the overall Amsterdam population. In the absence of contact
tracing and screening with tuberculin skin tests, periodic chest radiographic
screening contributes substantially to early casefinding of active tuberculosis
in Amsterdam drug users.
PMID- 10692966
TI - Southern Oscillation Index and transmission of the Barmah Forest virus infection
in Queensland, Australia.
PMID- 10692967
TI - The effect of a direct payment or a lottery on questionnaire response rates: a
randomised controlled trial.
PMID- 10692968
TI - Air pollution and mortality in a cohort of patients with chronic obstructive
pulmonary disease: a time series analysis.
PMID- 10692969
TI - Hospital admissions for asthma and chronic obstructive airways disease in east
London hospitals and proximity of residence to main roads.
PMID- 10692970
TI - Non-fatal head injury among Scottish young people: the importance of assault.
PMID- 10692971
TI - Treatment with ivermectin: what works in one community may not work in another.
PMID- 10692972
TI - Interim report and recommendations of the World Health Organization Task-Force
for Osteoporosis.
PMID- 10692973
TI - Bone mineral density and vertebral fractures in men.
AB - In women, many studies indicate that the risk of vertebral fragility fractures
increases as bone mineral density (BMD) declines. In contrast, few studies are
available for BMD and vertebral fractures in men. It is uncertain that the
strength of the relationship between BMD and fractures is similar in magnitude in
middle-aged men and in postmenopausal women. In the present study, 200 men (mean
age 54.7 years) with lumbar osteopenia (T-score < -1.5) were recruited to examine
the relationships between spine BMD and hip BMD and the associations of BMD with
vertebral fractures. Lumbar BMD was assessed from L2 to L4, in the
anteroposterior view, using dual-energy X-ray densitometry. At the upper left
femur, hip BMD was measured at five regions of interest: femoral neck,
trochanter, intertrochanter, Ward's triangle and total hip. Spinal radiographs
were analyzed independently by two trained investigators and vertebral fracture
was defined as a reduction of at least 20% in the anterior, middle or posterior
vertebral height. Spinal radiographs evidenced at least one vertebral crush
fracture in 119 patients (59.5%). The results of logistic regression showed that
age, femoral and spine BMDs were significant predictors of the presence of a
vertebral fracture. Odds ratios for a decrease of 1 standard deviation ranged
from 1.8 (1.3-2.8) for spine BMD to 2.3 (1.5-3.6) for total hip BMD. For multiple
fractures odds ratios ranged from 1.7 (1.1-2.5) for spine BMD to 2.6 (1.7-4.3)
for total hip BMD. In all models, odds ratios were higher for hip BMD than for
spine BMD, particularly in younger men, under 50 years. A T-score < -2.5 in the
femur (total femoral site) was associated with a 2.7-fold increase in the risk of
vertebral fracture while a T-score < -2.5 in the spine was associated with only a
2-fold increase in risk. This study confirms the strong association of age and
BMD with vertebral fractures in middle-aged men, shows that the femoral area is
the best site of BMD measurement and suggests that a low femoral BMD could be
considered as an index of severity in young men with lumbar osteopenia.
PMID- 10692974
TI - Influence of heredity and environment on bone density in adolescent boys: a
parent-offspring study.
AB - The purpose of the present parent-offspring study was to investigate the
influence of heredity and environment on bone density in young men. Another aim
was to discover whether the same genetic factors influence bone mass, lean mass
and muscle strength. Fifty families including a father, mother and one son were
investigated. The mothers (aged 44.5 +/- 4.4 years) and fathers (aged 47.1 +/-
4.4 years) generally had a sedentary lifestyle with little physical activity. As
a contrast, all but three of the sons (aged 17.0 +/- 0.4 years) were active in
ice hockey training. Bone mineral density (BMD, g/cm2) of the total body, head,
lumbar spine and femoral neck was measured using dual-energy X-ray
absorptiometry. Muscle strength of the hamstrings and quadriceps muscles was also
measured in the boys. BMD values of different sites in the fathers, mothers and
sons were adjusted for weight, height, age, and any significant influence of
environment. Heritability estimates were obtained as regression coefficients with
the boys' adjusted BMD as dependent variable and the adjusted midparent bone
density (father BMD + mother BMD/2) as independent variable. Accordingly,
heritability explained 34-54% of the variation in the sons' BMD. Midparent BMD of
several sites also predicted the boys' lean mass and quadriceps strength, and
midparent-offspring differences in lean mass predicted midparent-offspring
differences in BMD of the total body, head and spine (beta = 0.30-0.51, p <
0.05). The sons were found to have almost 30% higher femoral neck BMD than their
fathers, and physical activity (hours/week) predicted BMD at several sites among
the sons beta = 0.26-0.34, p < 0.05). In conclusion, heritability is a main
determinant of the variance in BMD in young men. Based on the results we suggest
that the same genetic factors may influence bone mass, lean mass and muscle
strength by affecting body size. The present study also emphasizes the importance
of physical activity for the development and maintenance of BMD in men.
PMID- 10692975
TI - Efficiency of quantitative ultrasound measurements as compared with dual-energy X
ray absorptiometry in the assessment of corticosteroid-induced bone impairment.
AB - Bone loss due to corticosteroid treatment differs from that of postmenopausal
osteoporosis with regard to bone structure. Corticosteroids affect both
horizontal and vertical trabeculae while horizontal trabeculae are damaged in
postmenopausal osteoporosis. Dual-energy X-ray absorptiometry (DXA) is the gold
standard to evaluate bone loss. The place of quantitative ultrasound (QUS), a
technique that could theoretically provide information on bone structure, is not
well established in corticosteroid-induced bone impairment. The aim of the study
was to determine the usefulness of QUS in the assessment of corticosteroid
induced bone impairment. We hypothesized that the relationship between QUS and
DXA could be influenced by changes in bone structure and thus differ with regard
to corticosteroid treatment. Seventy-seven women with inflammatory diseases
chronically treated with corticosteroids (dose: 7.5-15 mg/day), 29 without
corticosteroids and 100 controls were investigated. Bone mineral density at the
lumbar spine (BMDL) was measured by DXA and QUS parameters were measured at the
calcaneus. Both the QUS parameters (SOS, BUA, Stiffness) and BMDL were
significantly lower (by 1.3% for SOS, 5.8% for BUA, 12.7% for Stiffness and 11%
for BMDL) in patients treated with corticosteroids compared with patients not
taking corticosteroids and with controls (p < 0.001, ANCOVA, with age and height
as covariates). Multiple linear regressions of Stiffness, SOS and BUA as
dependent variables on age, BMDL, corticosteroid treatment and a computed new
variable designed to test the interaction between BMDL and the treatment group
showed that Stiffness, SOS and BUA were dependent on age and BMDL (p < 0.001);
BUA and Stiffness were dependent on treatment group. Taking into account the age
of the patients, a significant difference was observed in the relation between
BUA and BMDL according to treatment with corticosteroids. A similar difference
was found in the subgroup of patients without fractures. SOS and BUA were
strongly correlated but their relation did not differ according to treatment.
Thus, QUS is useful in the assessment of corticosteroid-associated bone loss.
Furthermore, the observation of a significant difference in the relationship
between BUA and BMDL with regard to corticosteroid treatment might support the
hypothesis that QUS, especially BUA, could give additional information about bone
structure.
PMID- 10692976
TI - Treatment of reduced bone mineral density in athletic amenorrhea: a pilot study.
AB - There is considerable concern about the adverse effects on the skeleton of loss
of menstrual function as a result of athletic activity, as well as uncertainty as
to how it should be managed clinically. In a pilot intervention study 34 elite
middle and long-distance runners, aged 18-35 years, with menstrual irregularity
due to their athletic activity were randomized to three groups: (A) to receive
hormone replacement therapy (HRT) and 1000 mg calcium per day (n = 10), (B) to
receive 1000 mg calcium per day (n = 14), (C) a control group who received no
treatment (n = 10). Bone mineral density (BMD) was measured in the left hip and
lumbar spine (L2-4) using dual-energy X-ray absorptiometry. Results were first
analyzed according to whether menstruation returned, either naturally or
secondary to HRT (EU), and compared with those from subjects who remained
amenorrheic (AM). During the first year BMD increased in the EU group in Ward's
triangle (3.8%) and the lumbar spine (4.1%; both P < 0.05). BMD fell in the AM
group in all regions and the between-group differences were 5.6% (p < 0.02) in
Ward's triangle, 5.8% (p < 0.02) in L2-4 and 3.9% in the trochanter (p < 0.05).
An 'intention to treat' analysis was then performed. It was found that the mean
relative improvement at 1 year in spinal BMD was only 1.5%, due to return of
menses in some of the controls and withdrawals from treatment in the treatment
group. In consequence, a trial designed to show, with 80% power and 5%
significance, a measurable benefit in lumbar spine BMD resulting from allocation
to HRT treatment would require about 1150 athletes with amenorrhea or
oligomenorrhea. These numbers could be reduced substantially to 380 subjects by
confining the trial to completely amenorrheic athletes, who in this study were
less likely to regain menses. For these and other logistical reasons, an HRT
trial in amenorrheic athletes could only be successfully organized through
international collaboration. This study illustrates the major effects of
treatment withdrawals and instability of menstrual status on the design of
longitudinal studies on the bony effects of menstrual dysfunction prior to
menopause.
PMID- 10692977
TI - Premature greying of the hair is not associated with low bone mineral density.
AB - In two recent case-control studies premature greying of the hair was associated
with a lowering of bone mineral density (BMD) and osteopenia, suggesting that
this might be a clinically useful risk marker for osteoporosis. We report a
further re-examination of this proposal in 52 prematurely grey-haired women from
East Yorkshire who responded to an advertisement inviting them for bone
densitometry. Thirty-five had no clinical or drug history that could influence
bone density. All were Caucasian with a mean age of 52.8 years. In the group as a
whole the mean BMD values at the lumbar spine and femoral neck were no different
from those of a young adult, but there was a trend toward a greater than average
BMD than that of the local age-matched population (p = 0.097 and 0.218,
respectively). Twenty women were premenopausal, with an average age of 45.3
years. Mean BMD values at the lumbar spine and femoral neck in this group were no
different from those of young adults. There was, however, a trend toward a BMD
greater than that of the local age-matched population at the femoral neck (p =
0.117). Fifteen women were postmenopausal with an average age of 62.9 years and
an average age at menopause of 51.1 years. Mean BMD values at both the lumbar
spine and femoral neck in this group were lower than those of young adults, but
no different from those of the local age-matched population. In conclusion, our
group of prematurely grey-haired women had average BMD for their age, and we are
therefore unable to support the proposed clinical usefulness of premature greying
as a risk marker for osteoporosis.
PMID- 10692978
TI - Disproportionate, age-related bone loss in long bone ends: a structural analysis
based on dual-energy X-ray absorptiometry.
AB - The width of long bone diaphyses apparently increase with age, a phenomenon that
is suggested to have some positive impact on bone strength. On the other hand,
these changes in size that are site-specific may cause a deterioration in the
local mechanical integrity of the whole bone. Physical activity and calcium
intake are known to be able to modify bone mass and size. It is, however, not
known whether these lifestyle habits can modify the postulated disproportionate
changes in bone size. To address this question, bone mineral content (BMC)
derived estimates of cross-sectional areas (CSA) of femur and radius in 158
premenopausal (mean age 43, standard deviation 2 years) and 134 postmenopausal
(63 (2) years), clinically healthy women with contrasting long-term histories in
physical activity and calcium intake were determined from dual-energy X-ray
absorptiometry (DXA) data. The DXA-obtained BMC correlated strongly with the
actual CSA (r = 0.94) determined with peripheral quantitative computed
tomography. The ratios between functionally interrelated CSA data (i.e., (radial
shaft CSA/distal radius CSA), (trochanter CSA/femoral neck CSA), (femoral shaft
CSA/trochanter CSA) and (femoral shaft CSA/femoral neck CSA)) were considered
primary outcome variables. Neither physical activity nor calcium intake
separately or interactively were associated with any CSA ratio. Age showed no
interaction with physical activity or calcium intake but was independently
associated with all CSA ratios, except the ratio of femoral shaft CSA to
trochanteric CSA. This study indicated clearly that a preferential reduction in
the cross-sectional area occupied by bone mineral occurs disproportionately at
the long bone ends as compared with diaphyseal sites, and this apparently
inherent, age-associated relative loss seems not to be prevented by physical
activity or calcium intake. In particular, given the utmost clinical relevance of
the proximal femur region, an observed loss in femoral neck CSA of about 10% in
contrast to about a 5% loss in trochanteric CSA warrants further investigation
regarding its potential role as a predictor for hip fracture. Not only the local
differences in bone composition but also the biomechanical aspects are important
factors underlying these apparent changes in CSA at the studied skeletal sites.
PMID- 10692979
TI - VDR genotype and response to etidronate therapy in late postmenopausal women.
AB - Twenty-four late postmenopausal women with osteoporosis were studied. The
patients were separated in three subgroups according to the BsmI polymorphism of
the vitamin D receptor (VDR) gene: BB (n = 8), Bb (n = 10) and bb (n = 6). They
did not differ in age (mean ages were 66.0 years, 65.9 years and 63.9 years,
respectively), years after menopause (18.7 years, 18.1 years and 18.4 years) or
body weight (64.9 kg, 65.3 kg and 63.8 kg), the variables known to be associated
with bone mineral density (BMD). The results show that the response to
antiresorptive bisphosphonate therapy in combination with calcium supplementation
is modified by VDR genotype. The lumbar spine BMD increased significantly faster
in the BB and Bb groups (7.3% and 7.0%, respectively) compared with the bb group
(2.5%) during 1 year of cyclic etidronate therapy (400 mg/day) and calcium
supplementation (1000 mg/day). The biochemical marker of bone resorption (urinary
hydroxyproline excretion) as well as the bone formation marker (serum levels of
osteocalcin) decreased during the treatment. With respect to VDR genotype, a
significantly higher decrease in osteocalcin level was observed in bb as compared
with BB subjects. We conclude that the VDR genotype is involved in an
individual's response to cyclic etidronate therapy with calcium supplementation.
PMID- 10692980
TI - Bone mineral in pre- and postmenopausal women with insulin-dependent and non
insulin-dependent diabetes mellitus.
AB - The aim of the study was to compare bone mineral density (BMD) and bone turnover
in pre- and postmenopausal women with insulin-dependent diabetes mellitus (IDDM),
non-insulin-dependent diabetes mellitus (NIDDM) and normal reference women. In a
cross-sectional study 31 and 11 premenopausal and 22 and 21 postmenopausal IDDM
and NIDDM patients, respectively, were recruited from an outpatient clinic. BMD
in the forearm, spine, femur and total body and biochemical markers of bone
turnover were measured and compared with reference values obtained from
measurements of normal healthy pre- and postmenopausal women. Postmenopausally,
but not premenopausally, IDDM patients had lower BMD values than NIDDM patients.
Postmenopausal NIDDM patients had higher BMD value than normal women. The
differences in BMD between IDDM and NIDDM patients could be explained
statistically by differences in body weight between the NIDMM (obese) and IDDM
(lean) women. Markers of bone turnover were significantly higher postmenopausally
than premenopausally in both IDDM and NIDDM patients. Osteocalcin was
significantly lower in postmenopausal NIDDM compared with postmenopausal IDDM
patients and reference values. Otherwise there were no differences in the markers
of bone turnover between NIDDM and IDDM patients. In conclusion, postmenopausal
IDDM patients have a relatively decreased BMD, whereas NIDDM patients seem to be
relatively protected from postmenopausal bone loss.
PMID- 10692981
TI - Perception of osteoporosis by Belgian women who work in a university hospital.
AB - Campaigns to increase 'awareness' of osteoporosis have been organized. The aim of
this study was to assess how Belgian women who benefit from superior conditions
favoring 'awareness' perceive osteoporosis as being an important disease. A
survey sent to the private home of all the women working in a university hospital
in Brussels (n = 1154). From a list of 13 diseases the women were asked to rank,
by order of importance, the five which they found to be the most important for a
woman of their age. They were also asked about visits to physicians, and
screening procedures. The response rate was 55.4%. A high uptake of medical
visits and screening procedures was reported: 89% of the women had seen a general
practitioner or a gynecologist and 81.6% had undergone at least one gynecologic
examination during the previous year. Three times more women had ever undergone
mammography than a bone mineral density (BMD) measurement. Overall, 18.1%
reported having had a BMD measurement in the past. In women over 50 years, 61%
reported having had a BMD measurement and 92.7% having had a mammogram.
Osteoporosis was ranked among the five most important diseases by 19.4% of women
before the age of 50 years and by 39.3% after that age, far behind breast cancer
(respectively 86.3% and 77.7%) and uterine cancer (respectively 74.2% and 58.0%).
Thus even among a population of women who benefit from superior conditions for
information and screening, the perception of osteoporosis remains low, as does
the uptake of osteoporosis screening.
PMID- 10692982
TI - Calcaneal ultrasound attenuation in an elderly population: measurement position
and relationships with body size and past fractures.
AB - This study demonstrates, the relationship between past fracture, body size and
broadband ultrasound attenuation (BUA) and investigates two sites of BUA
measurement in a representative elderly population of men and women (n = 2106).
We measured BUA at a fixed position and at a consistent anatomic position within
the calcaneus. We found fixed BUA was less closely correlated with stature and
age than anatomic BUA. Both correlations were substantially weaker in men than in
women. Mean BUA was significantly lower in women with a past fracture compared
with nonfracturers (fixed BUA 63.3 vs 69.4 dB/MHz, p = 0.0004; anatomic BUA 77.6
vs 81.7 dB/MHz, p = 0.013). However, in women, the fixed BUA was better than the
anatomic BUA at discriminating between fracturers and nonfracturers (OR 1.38/SD
(95% CI 1.12-1.68) and OR 1.22/SD (0.99-1.52), respectively) when adjusted for
body size and age. There was no significant difference in either BUA in men with
or without a past fracture. In conclusion, currently the fixed position for BUA
measurement is preferable and, whilst we have demonstrated that it is possible to
locate an anatomically consistent point in the calcaneus, the position chosen by
this study did not provide a measurement with more discriminatory capability than
the fixed position. In women, BUA behaves similarly to bone mineral density in
relation to stature and in its strength of association with past fracture, while
the lack of association in men may reflect differing contributions by bone
strength to fracture risk in the sexes.
PMID- 10692983
TI - Incomplete renal tubular acidosis in 'primary' osteoporosis.
AB - Chronic metabolic acidosis may increase alkali mobilization from bone and thus
promote the development of osteoporosis. While it is undisputed that overt
metabolic acidosis is associated with metabolic bone disease, renal acidification
in patients with idiopathic osteoporosis has not been studied systematically. The
purpose of this study was to investigate the prevalence of renal acidification
defects in patients with 'primary' osteoporosis. Thirty-two women (including 10
premenopausal women) and 16 men who were referred to our department for
investigation of osteoporosis were enrolled in this study. Patients with obvious
or possible secondary osteoporosis were excluded. None of the patients had overt
metabolic acidosis. In random urine samples 12 of the 48 patients had pH levels
below 5.5 and were therefore considered to have normal renal acidification. The
remaining 36 patients underwent further testing by a short-course oral ammonium
chloride load. In this test nine of these 36 patients (7 men and 2 premenopausal
women) failed to lower urinary pH below 5.5 despite the induction of systemic
metabolic acidosis. In these patients, therefore, the diagnosis of incomplete
distal renal tubular acidosis was made (RTA I). Patients with incomplete RTA I
had significantly lower spontaneous plasma pH (7.38 +/- 0.0081 vs 7.41 +/- 0.004,
mean +/- SEM, p = 0.002), a lower serum bicarbonate concentration (21.9 +/- 0.49
mmol/l vs 23.1 +/- 0.24 mmol/l, p = 0.034), a lower base excess (-2.33 +/- 0.42
mmol/l vs -0.55 +/- 0.21 mmol/l, p = 0.001) and lower Z-scores in bone
densitometry (-2.18 +/- 0.27 vs -1.40 +/- 0.15, p = 0.028) than patients with
normal renal acidification. In conclusion, a high prevalence of incomplete RTA I
(in 44% of the male patients, 20% of the premenopausal female patients and 6% of
all female patients) was found in patients with osteoporosis who, without
testing, would have been diagnosed as having 'primary' osteoporosis. The mild
metabolic acidosis observed in these patients may have contributed to loss of
bone mass by a compensatory mobilization of alkali and calcium from bone. Because
of possible therapeutic consequences (e.g., administration of alkali salts and
high doses of vitamin D) we propose that measurements of urinary pH and, if
necessary, ammonium chloride testing should be included in the diagnostic
investigation especially of male and of premenopausal female patients with
osteoporosis. Since referral bias, although unlikely, cannot be excluded in our
study, the prevalence of RTA I in unselected patients with osteoporosis needs to
be determined at primary screening institutions.
PMID- 10692984
TI - Treatment of postmenopausal women with osteoporosis or low bone density with
raloxifene. Raloxifene Study Group.
AB - Raloxifene, a selective estrogen receptor modulator (SERM), has been shown to
improved bone mineral density (BMD) and serum lipid profiles in healthy
postmenopausal women. The objective of this study was to examine the effects of
raloxifene on BMD, biochemical markers of bone metabolism and serum lipids in
postmenopausal women with low bone density or osteoporosis. This Phase II,
multicenter, 24-month, double-masked study assessed the efficacy and safety of
raloxifene in 129 postmenopausal women (mean age +/- SD: 60.2 +/- 6.7 years) with
osteoporosis or low bone density (baseline mean lumbar spine BMD T-score: -2.8).
Women were randomly assigned to one of three treatment groups: placebo, 60 mg/day
raloxifene-HCl (RLX 60) or 150 mg/day raloxifene-HCL (RLX 150) and concomitantly
received 1000 mg/day calcium and 300 U/day vitamin D3. At 24 months, BMD was
significantly increased in the lumbar spine (+3.2%), femoral neck (+2.1%),
trochanter (+2.7%) and total hip (+1.6%) in the RLX 60 group compared with the
placebo group (p < 0.05). The RLX 150 group had increases in BMD similar to those
observed with RLX 60. A greater percentage of raloxifene-treated patients,
compared with those receiving placebo, had increased BMD (p < 0.05). Serum bone
specific alkaline phosphatase activity, serum osteocalcin, and urinary type I
collagen:creatinine ratio were significantly decreased in the RLX-treated groups,
compared with the placebo group (p < 0.01). RLX 60 treatment significantly
decreased serum levels of triglycerides, and total- and LDL-cholesterol levels (p
< 0.01). The rates of patient discontinuation and adverse events were not
significantly different among groups. In this study, raloxifene increased bone
density, decreased bone turnover, and improved the serum lipid profile with
minimal adverse events, and may be a safe and effective treatment for
postmenopausal women with osteoporosis or low bone density.
PMID- 10692985
TI - An early-life femoral shaft fracture and bone mineral density at adulthood.
AB - High peak bone mass and density in early adulthood is an important protective
factor against osteoporotic fractures in later life, but it is not known whether
injuries to growing bones adversely affect the attainment of peak bone mass and
density. The purpose of this study was therefore to examine with dual-energy X
ray absorptiometry the areal bone mineral density (BMD) of the injured and
uninjured extremity (the femoral neck, trochanter area of the femur, distal
femur, patella, proximal tibia and distal tibia), lumbar spine and distal radius
of young adults with a history of an early-life femoral shaft fracture and to
find out whether the fracture had affected the attainment of peak bone density of
these patients. Thus, the BMD and clinical status of 41 patients (28 men, 13
women) who had sustained a femoral shaft fracture in childhood or adolescence
(between 7 and 15 years of age, average 13 years before the study) were examined.
The fracture had led to a statistically significant difference in BMD between the
injured and uninjured side distal to the fracture site (men/women: distal femur,
3.7%/-3.9%; patella, -3.1%/-5.9%; proximal tibia, -2.0%/-4.6%; distal tibia,
3.4%/-5.2%), whereas the proximal femur did not show such differences. The male
patients' spinal BMD was significantly lower (-7.9%) than that in their age-,
height- and weight-matched healthy controls. The female patients' spinal BMD
tended to be fairly comparable (-1.6%) to that of the controls (NS). In summary,
this study indicates that early-life femoral shaft fracture results in a moderate
(-2% to -6%) long-term side-to-side BMD difference distal to the fracture site.
Patients' spinal BMD values also tend to be lower than that of controls. Thus, a
femoral shaft fracture sustained in childhood or adolescence seems to disturb
somewhat the attainment of peak bone density, the important predictor of
osteoporotic fractures in later life.
PMID- 10692986
TI - Toxicity of nitrogen oxides and related oxidants on mycobacteria: M. tuberculosis
is resistant to peroxynitrite anion.
AB - OBJECTIVE: To test the toxicity of reactive nitrogen intermediates (RNI),
including authentic nitric oxide (NO), nitrogen dioxide (NO2), and peroxynitrite
anion (ONOO-), a potent oxidant derived from NO and superoxide anion, on various
mycobacterial strains including M. tuberculosis. DESIGN: Relatively avirulent
mycobacteria including M. smegmatis and BCG, as well as the pathogenic M. Bovis
Ravenel and M. tuberculosis Erdman and the clinical isolate M160 (also known as
the C strain) were tested for their susceptibility to the toxic effects of NO,
NO2, and ONOO-, Deaerated, NO-saturated solutions as well as an anaerobic in
vitro system in which mycobacteria can be exposed to desired concentrations of
authentic NO or NO2, were employed in these studies. An in vitro ONOO- killing
assay was used to examine the adverse effects of this NO-derived oxidant on the
various strains of mycobacteria. RESULTS: Both NO and NO2 exhibit
antimycobacterial activity, with the former being more potent. Results obtained
using ONOO- killing assay revealed that while avirulent mycobacteria including
BCG and M. smegmatis are susceptible to this NO-derived oxidant, the virulent
Erdman strain of M. tuberculosis and M. bovis, as well as the clinical
tuberculous isolate M160, are remarkably resistant. CONCLUSION: These results
suggest that the interactions between RNI and various species of mycobacteria
could be highly specific. And since activated macrophages produce peroxynitrite,
the significance of the ONOO- resistance of M. tuberculosis strains in relation
to intracellular survival deserves further investigation.
PMID- 10692987
TI - Influence of HLA-DR antigens on lymphocyte response to Mycobacterium tuberculosis
culture filtrate antigens and mitogens in pulmonary tuberculosis.
AB - SETTING: Influence of HLA-DR antigens and lymphocyte responses in pulmonary TB
patients. OBJECTIVE: To elucidate the role of HLA-DR genes/gene products on
lymphocyte responses to Mycobacterium tuberculosis antigens and mitogens, the
present study was carried out in pulmonary tuberculosis during active and cured
stage of the disease. DESIGN: Serological determination of HLA-DR antigens was
carried out in 50 active TB patients, 44 cured TB patients and 58 normal healthy
control subjects. The influence of HLA-DR antigens on peripheral blood lymphocyte
responses to M. tuberculosis culture filtrate antigens and mitogens such as
phytohaemagglutinin (PHA) and concanavalin-A (Con-A) was studied in the patients
as well as normal healthy control subjects. RESULTS: Of all the DR antigens
studied, patients (active TB and cured TB) with DR2 antigen showed an increased
lymphocyte response (stimulation index) to a higher dose of antigenic (10
micrograms/ml) stimulation. A significantly lower lymphocyte response to antigen
and mitogens was seen in HLA-DR3 positive normal healthy subjects than non-DR3
(DR3 negative) subjects. CONCLUSION: The present study suggests that HLA-DR
genes/gene products may be playing an immunoregulatory role in eliciting an
immune response against M. tuberculosis antigens and mitogens induced lymphocyte
response in pulmonary TB patients and normal healthy subjects.
PMID- 10692988
TI - Effects of modulating TGF-beta 1 on immune responses to mycobacterial infection
in guinea pigs.
AB - SETTING: TGF-beta 1 has been implicated as an important mediator of immuno
suppression in clinical tuberculosis. OBJECTIVE: The objective was to determine
the role of TGF-beta 1 in experimental pulmonary tuberculosis in the guinea pig.
DESIGN: Groups of guinea pigs, maintained on either a low protein (LP) diet or an
isocaloric high protein (HP) diet, were challenged via the respiratory route with
virulent Mycobacterium tuberculosis H37Rv. Ten days post-infection, guinea pigs
were given daily intraperitoneal injections of recombinant human TGF-beta 1
(rhTGF-beta 1 tau for 10 consecutive days). Following the treatment, guinea pigs
were euthanized, and PPD-induced proliferation of peripheral blood mononuclear
cells (PBMCs) was assessed and disease resistance measured by recovery of
mycobacteria from the lungs and spleens. In a second set of experiments, groups
of HP and LP guinea pigs were vaccinated with attenuated M. tuberculosis H37Ra.
Six weeks later, the effects of rhTGF-beta 1 on lymphoproliferation and cytokine
production were determined. RESULTS: Protein deficiency significantly impaired
host anti-tuberculosis resistance, as expected. Treatment with rhTGF-beta 1
significantly increased mycobacterial loads in the tissues of guinea pigs and
decreased the PPD-induced proliferation of PBMCs from both LP and HP guinea pigs.
PPD-driven lymphoproliferation, TNF-alpha and IFN production were significantly
suppressed in vaccinated, protein-deficient guinea pigs, and rhTGF-beta 1 further
inhibited lymphoproliferation and cytokine production. CONCLUSION: Both in vivo
and in vitro results indicate that TGF-beta 1 exerts immunosuppressive activity
and exacerbates the progression of experimental pulmonary tuberculosis in both
normally nourished and protein-deficient guinea pigs.
PMID- 10692989
TI - Increased absolute number but not proportion of gamma/delta T-lymphocytes in the
bronchoalveolar lavage fluid of patients with active pulmonary tuberculosis.
AB - SETTING: The proportions and absolute cell count of gamma/delta T-lymphocytes in
the peripheral blood of patients with pulmonary tuberculosis (PTB) remains
controversial. Since PTB is an infections airway disease, bronchoalveolar T
lymphocytes should be a better indicator of local immune T-cell reaction after TB
infection than peripheral blood T-lymphocytes. OBJECTIVE: To quantitate the
absolute cell count and proportions of gamma/delta T-lymphocytes in the
bronchoalveolar lavage fluid (BALF) of patients with active PTB. DESIGN:
Bronchoalveolar lavage (BAL) and analysis of lymphocytes in the BALF was
performed in 25 patients with active PTB and 16 normal controls. All of the
patients were negative for HIV infection and none was immunocompromised. BALF and
blood were prepared for cell differential count and flow cytometry analysis using
monoclonal antibodies CD3, CD4, CD8, CD25, HLA-DR and gamma/delta as well as
alpha/beta T-lymphocyte receptors. RESULTS: The number of cells per volume of
recovered BALF was significantly higher in the patients with active PTB than in
normal controls. BALF from active PTB patients also showed increased percentage
of lymphocytes and neutrophils. The absolute number of total lymphocytes, CD3+
lymphocytes and CD3+ gamma/delta T-lymphocytes were significantly higher in the
BALF, but not in the blood, of patients with TB, however, the proportions of CD3+
gamma/delta T-lymphocytes in BALF of patients with TB was comparable to that of
normal controls. gamma/delta T-lymphocytes in the BALF rarely expressed CD4,
CD25, and HLA-DR in both groups. CONCLUSION: These results suggest that
gamma/delta T-lymphocytes are not the major subpopulation of CD3+ lymphocytes in
the BALF that react to mycobacterial infection in the patients with clinically
established active TB.
PMID- 10692990
TI - Association of functional mutant homozygotes of the mannose binding protein gene
with susceptibility to pulmonary tuberculosis in India.
AB - SETTING: Mannose binding protein gene polymorphism in pulmonary tuberculosis in
India. OBJECTIVE: To find out whether non-HLA genes such as mannose binding
protein (MBP) genes are associated in the susceptibility to pulmonary
tuberculosis. DESIGN: Genotyping of MBP 52, 54 and 57 wild and mutant alleles was
carried out in HLA-DR typed pulmonary tuberculosis patients (n = 202) and control
subjects (n = 109). Since HLA-DR2 is associated with pulmonary-TB, the
interaction of MBP genes on -DR2 and non-DR2 genes on the susceptibility was also
studied. RESULTS: A significantly increased genotype frequency of MBP functional
mutant homozygotes (including 52, 54 and 57) was seen in pulmonary tuberculosis
(PTB) patients (10.9%) than in control subjects (1.8%; P = 0.008; odds ratio:
6.5). Analysis of interaction of MBP genes and HLA-DR2 on the susceptibility to
PTB revealed that these genes are associated with PTB independent of each other.
CONCLUSION: The present study shows that functional mutants of MBP are associated
with PTB. Apart from HLA-DR2 association, association of non-HLA genes in the
susceptibility to PTB is evident. This suggests that multigenetic factors
(candidate genes) may be involved in the susceptibility/resistance to PTB.
PMID- 10692991
TI - Diagnostic efficacy of polymerase chain reaction in granulomatous uveitis.
AB - SETTING: The granulomatous uveitis, multifocal choroiditis and periphlebitis have
been suspected to be of tubercular origin but no definitive reports about
detection of etiological agents have been documented in the literature.
Conventional bacteriological methods are not generally helpful in diagnosing
ocular tuberculosis due to difficulty with potential morbidity associated with
obtaining the biopsy material from the eye. Thus, the diagnosis of ocular
tuberculosis is most often presumptive. OBJECTIVE: We evaluated the role of
polymerase chain reaction (PCR) for detection of Mycobacterium tuberculosis in
the aqueous humor samples obtained from eyes with active uveitis. METHODS:
Aqueous samples from 53 patients having cellular reaction in the anterior chamber
along with any one or more of the following: 1) active vasculitis; 2) anterior
vitreous cells; 3) snowball opacities; 4) snow banking in the pars plana; 5)
retinochoroiditis were withdrawn by anterior chamber paracentesis and subjected
to PCR. Seventeen samples from patients with definite clinical diagnoses other
than tuberculosis formed a disease control group. Fifteen aqueous samples
obtained from healthy subjects undergoing routine cataract surgery served as
healthy controls. PCR was performed using primers capable of amplifying a 150
b.p. segment from a conserved repetitive sequence in the genome of M.
tuberculosis. RESULTS: Twenty out of the 53 samples (37.7%) in the study group
were positive where as only one sample out of 17 in the disease control group
(5.7%) showed a weakly positive band. No sample from the healthy control group
showed a positive PCR. CONCLUSION: Our study shows that PCR can be effectively
used for the diagnosis of intraocular tuberculosis in the presence of uveitis.
PMID- 10692992
TI - Hypodense alveolar macrophages in patients with diabetes mellitus and active
pulmonary tuberculosis.
AB - SETTING: Alveolar macrophages (AM), a heterogeneous cell population, play a
critical role in eliminating mycobacterial infections in collaboration with
lymphocytes. Patients with diabetes mellitus (DM) show increased susceptibility
to pulmonary tuberculosis (TB) infection. It is still uncertain whether there is
a defect in T cell or AM activation in patients with DM against TB infection.
OBJECTIVE: To study the difference in activation status of AM and T cells between
patients with TB + DM and TB alone. METHOD: The heterogeneity of AM from 14
patients with TB + DM, 9 with TB alone, 10 normal subjects and 8 DM alone
patients, was studied using Percoll density fractionation. The intracellular H2O2
production of AM before and after stimulation with phorbol myristate acetate
(PMA) or F-Met-Leu-Phen (FMLP) was assayed by loading cells with 2',7'
dichlorofluorescin (DCFH) and analyzed by flow cytometry. Lymphocytes subsets
(CD3, CD4, CD8) and their activation status (CD25) in bronchoalveolar lavage were
also measured. RESULTS: The proportion of the least dense AM (< 1,030 g/ml) and
the magnitude of DCFH oxidation of AM was higher in TB patients than in normal
subjects, regardless of DM. Patients with TB + DM had a significantly lower
proportion of the least density AM fraction than TB alone patients, regardless of
disease extent. Among TB patients, the proportion of the least dense AM was
inversely correlated with the bacterial load on sputum and the disease extent on
chest radiograph. Stimulation of AM with PMA or FMLP induced an increase in the
hypodense AM subpopulations and enhanced intracellular H2O2 generation in
patients with TB + DM and to a similar extent in normal subjects, but not in
patients with TB alone. There was no significant difference in CD3 numbers,
CD4/CD8 ratio, and CD25+ cells between patients with TB alone and TB + DM. The
activation status of AM or T lymphocytes from DM alone patients was not
significantly different from those from normal subjects. CONCLUSION: Hypodense
subpopulations of AM increase in active TB patients and are related to the
disease severity as well as activation status of AM. AM in TB patients
complicated with DM was less activated, and may be contributory to the
susceptibility to mycobacterial infection.
PMID- 10692993
TI - Development of the Mycobacterium bovis BCG vaccine: review of the historical and
biochemical evidence for a genealogical tree.
AB - The original Mycobacterium bovis Bacillus Calmette Guerin vaccine strain has
developed into several different substrains which have been used for production
of BCG vaccines throughout the world since 1921. Based on the latest genetic and
antigenic knowledge, as well as the early literature reports on BCG vaccination,
we are able to fit the different pieces of the BCG puzzle together and outline
the origin of the different substrains of M. bovis BCG. The BCG vaccine
substrains analysed demonstrate two distinct patterns, with an abrupt change
consisting of a loss of several genes and altered biochemical characteristics in
strains originating from Institut Pasteur after 1927. Further evidence from the
literature is provided that a change occurred in virulence of the BCG parent
strain at Institut Pasteur in the late 1920s. Based on this information a
genealogical tree is proposed and discussed.
PMID- 10692994
TI - Immunogenicity and protective efficacy of DNA vaccines encoding secreted and non
secreted forms of Mycobacterium tuberculosis Ag85A.
AB - OBJECTIVE: To determine the efficacy of Ag85A-DNA against challenge with a highly
virulent human clinical isolate of Mycobacterium tuberculosis (CSU37) and to
compare the potencies of two types of Ag85A-DNA vaccines; those expressing
secreted and non-secreted forms of the protein. DESIGN: Ag85A-DNA vaccinated mice
were challenged with a highly virulent clinical isolate of M. tuberculosis
(CSU37) in order to compare the efficacy of these vaccines. In vitro studies were
also performed. RESULTS: Enhanced humoral and cellular responses were induced in
mice vaccinated with the secreted Ag85A-DNA compared to the non-secreted Ag85A
DNA. In addition, secreted Ag85A-DNA conferred protective immunity against
infection with M. tuberculosis (CSU37). CONCLUSIONS: DNA vaccines encoding M.
tuberculosis Ag85A have been shown to induce potent humoral and cellular immune
responses leading to protection from M. tuberculosis (Erdman) challenge in mouse
models. In this study we demonstrate that Ag85A can confer protection in a
rigorous challenge model using a highly virulent human clinical isolate of M.
tuberculosis (CSU37). This challenge model appears able to discriminate between
DNA vaccines of differing potencies, as the more immunogenic DNA construct
encoding a secreted form of Ag85A was protective, whereas the less immunogenic
DNA construct encoding a non-secreted form of Ag85A was not.
PMID- 10692995
TI - Mechanisms of vaccine-induced resistance in a guinea pig model of pulmonary
tuberculosis.
PMID- 10692996
TI - The molecular basis of isoniazid resistance in Mycobacterium tuberculosis.
PMID- 10692997
TI - Rapid kinetic spectrophotometric determination of phosalone (Zolone) in a
commercial formulation.
AB - A kinetic study of the degradation of phosalone in an alkaline medium was
undertaken by using a pneumatic stopped-flow system. A rapid semiautomatic method
is proposed for determining phosalone. Linear calibration graphs up to 8.0 x 10(
5) M (detection limit = 1.40 x 10(-6) M) were obtained, with a measurement period
of only 3.5 s per sample and a relative standard deviation of 1.4%. Several
pesticides were assayed as interference species, and several did not interfere
even at a 6:1, M:M foreign species/phosalone ratio. A strong interference (ratio
< 1) was generated by azinphos-methyl and carbaryl. The proposed method was
applied to the analysis of a commercial formulation, and the results were
validated by comparison with those for a chromatographic method.
PMID- 10692998
TI - Determination of histidine and related compounds in rumen fluid by liquid
chromatography.
AB - A liquid chromatographic procedure was developed for quantitative determination
of histidine (His), histidinol (HDL), histamine (HTM), urocanic acid (URA),
imidazolepyruvic acid (ImPA), imidazoleacetic acid (ImAA), and imidazolelactic
acid (ImLA) in rumen fluid. The method is based on direct injection analysis by
UV absorbance detection at 220 nm. The separation was performed under 2 different
chromatographic conditions on a LiChrospher 100 NH2 column. In the first
chromatographic system, the mobile phase used for isocratic elution was 67 mM
potassium phosphate buffer (monobasic and dibasic) pH 6.45-90% acetonitrile in
water (21 + 79); in the second system, an acetonitrile gradient in 63 mM
potassium phosphate buffer (monobasic) pH 3.0, obtained by addition of 60 mM
phosphoric acid, was used. Analyses of both systems were completed within 32 and
25 min, respectively. The limits of detection of these compounds were (microM):
His, 2.8; HDL, 3.7; HTM, 4.0; URA, 0.75; ImPA, 4.7; ImAA, 1.2; and ImLA, 1.3.
Recovery of these compounds added to rumen fluid was 97.4-103.0% within a 1-day
study and 95.4-99.0% on different day studies. Detectable levels of His were
found in the deproteinized rumen fluid of goats, with average concentrations of
16.10, 10.43, 11.14, and 13.62 microM in the rumen fluid collected before the
morning feeding and 2, 4, and 6 h after feeding, respectively. HDL, HTM, URA,
ImPA, ImAA, and ImLA were not detected in the rumen fluid before and after
feeding. Trp, Phe, and Tyr were also identified in the rumen fluid, with average
concentrations of 8.25, 29.04, and 12.6 microM, respectively, before the morning
feeding.
PMID- 10692999
TI - Rapid determination of nosiheptide in meat and egg by liquid chromatography with
fluorescence detection.
AB - A procedure was developed to determine nosiheptide residues in marketed meat and
egg. Acetonitrile was used for the extraction, and the extract was partitioned
with hexane to remove fat. The lower layer was reconstructed and quantitated by
liquid chromatography using fluorescence detection at 357 nm excitation and 500
nm emission. The mobile phase consisted of 0.025% phosphoric acid-acetonitrile
(50 + 50, v/v). Recoveries of nosiheptide from fortified samples ranged from 91.3
to 95.2% for swine muscle, 88.6 to 92.7% for chicken muscle, and 86.3 to 86.8%
for egg. The method was used to monitor swine and chicken muscle and egg (20
samples each) in the market. Nosiheptide was not determined in all 60 samples.
PMID- 10693000
TI - Determination of amoxicillin residues in animal tissues by solid-phase extraction
and liquid chromatography with fluorescence detection.
AB - Trace levels of amoxicillin residues were determined in animal tissues by liquid
chromatography (LC) with fluorescence detection. An improved solid-phase
extraction (SPE) procedure requiring less flammable solvent (diethyl ether) was
developed for sample preparation. Muscle samples of beef, pork, chicken, and
tilapia were extracted with a phosphate buffer followed by the modified SPE
procedure for cleanup and concentration prior to the LC-fluorescence analysis.
Average recoveries of fortified amoxicillin at 5, 10, and 20 micrograms/kg ranged
from 83.9 to 85.8% in beef, 86.1 to 88.1% in pork, 81.7 to 82.9% in chicken, and
92.5 to 95.4% in tilapia. Relative standard deviations were < 4%.
PMID- 10693001
TI - Simultaneous determination of residues of chloramphenicol, florfenicol,
florfenicol amine, and thiamphenicol in shrimp tissue by gas chromatography with
electron capture detection.
AB - A gas chromatographic (GC) method is presented for determining residues of
chloramphenicol (CAP), florfenicol (FF), florfenicol amine (FFa), and
thiamphenicol (TAP) in shrimp tissues, with meta-nitrochloramphenicol (mCAP) as
the internal standard. The composited shrimp is extracted with basic ethyl
acetate, followed by an acetonitrile-basic ethyl acetate mixture. This extract is
centrifuged, filtered, evaporated, and reconstituted in water; the reconstituted
extract is acidified, defatted with hexane, and passed through a propylsulfonic
acid (PRS) and C18 solid-phase extraction (SPE) system. The C18 SPE column is
eluted with methanol, and the PRS SPE column is eluted with basic MeOH plus
counter ion. The combined eluates are evaporated, reconstituted in acetonitrile,
and derivatized with Sylon BFT. After derivatization, the addition of toluene
directly to the sample, followed by the addition of basic water, quenches the
derivatization process. After centrifugation, the organic layer is carefully
removed, and the analytes are determined by GC with electron capture detection.
Shrimp tissues were fortified with fenicols (i.e., CAP, FF, FFa, and TAP) at 5,
10, 20, 40, and 80 ng/mL. Overall recoveries were 88, 101, 91, and 84% with
overall interassay (between-day) variabilities (i.e., relative standard
deviations) of 5.3, 9.4, 12.8, and 7.4% for CAP, FF, FFa, and TAP, respectively.
The method detection limits were calculated as 0.7, 1.4, 2.4, and 1.3 ng/g (ppb)
for CAP, FF, FFa, and TAP, respectively, based on a 10 g sample. The quantitation
limit as determined empirically by this method is the lower limit of the standard
curve, which is about 5 ng/g (ppb) for each analyte.
PMID- 10693002
TI - Simultaneous determination of eprinomectin, moxidectin, abamectin, doramectin,
and ivermectin in beef liver by LC with fluorescence detection.
AB - Eprinomectin, moxidectin, abamectin, doramectin, and ivermectin are drugs used to
control parasitic infections in both meat-producing and nonmeat-producing
animals. A number of analytical methods are available to analyze these
anthelmintic drugs individually. A multiresidue screening method was developed
for these drugs; however, the initial attempt to derivatize eprinomectin
following the method published by Merck scientists was unsuccessful because the
eprinomectin derivatization reaction was temperature- and time-dependent. The
optimum time and temperature for the completion of eprinomectin derivatization
were 90 min and 65 degrees C, respectively, without appreciable effect on the
remaining 4 drugs. Beef liver samples were fortified with 0, 25, 50, and 100 ppb
mixed standards of eprinomectin, moxidectin, abamectin, doramectin, and
ivermectin. Each set of 4 levels of recoveries was repeated 10 times with all 5
compounds. The average of 10 recoveries of 5 compounds at all 4 levels of
fortification was > 70%; the coefficient of variation was < 20%.
PMID- 10693003
TI - Confirmation of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin
in beef liver by liquid chromatography/positive ion atmospheric pressure chemical
ionization mass spectrometry.
AB - A liquid chromatographic (LC) multiresidue screening procedure was developed for
determination of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin
in beef liver at 0, 25, 50, and 100 ppb levels. A procedure using low resolution
LC/atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) was
developed with further purification steps added to the quantitative LC method to
confirm residues. Acetonitrile extracts of liver, prior to derivatization for LC
analysis, were further purified by using a C8 solid-phase extraction cartridge
and an alumina-B cartridge. The purified extract was analyzed by injection into
an LC/positive ion APCI MS. Identity of the compound was confirmed by comparison
of its retention time and relative intensity data with those of a standard or
recovery from a fortified control liver sample. Anthelmintic drugs in
acetonitrile extracts of liver containing eprinomectin, moxidectin, abamectin,
doramectin, and ivermectin at 25 ppb, the lowest level of fortification used in
the LC determinative method, were successfully confirmed.
PMID- 10693004
TI - Comparative photodegradation study of atrazine and desethylatrazine in water
samples containing titanium dioxide/hydrogen peroxide and ferric
chloride/hydrogen peroxide.
AB - Results are reported for a comparative photodegradation study of atrazine and
desethylatrazine in water using TiO2/H2O2, FeCl3/H2O2, and photolysis. Deionized
water and ground water spiked with atrazine or desethylatrazine at 36
micrograms/L were irradiated by using a xenon arc lamp and/or sunlight. After
irradiation, the water samples containing the spiked pesticides were
preconcentrated by using C18 solid-phase extraction disks and analyzed by gas
chromatography with nitrogen-phosphorus and mass spectrometric detection. A
relative percentage of 7% desethylatrazine was detected in samples removed after
20 and 4 min of sensitized photodegradation with TiO2 and Fe3+, respectively.
Atrazine and desethylatrazine did not degrade when solar irradiation (in winter)
and deionized water were used. Atrazine degraded faster than desethylatrazine
when a xenon arc lamp or sunlight plus FeCl3 was used, with half-lives varying
from 5 to 11 min and from 19 to 26 min, respectively. In other photodegradation
experiments, the degradation of atrazine was slightly higher than that of
desethylatrazine. This study shows that desethylatrazine has slightly higher
stability than atrazine in environmental water samples; this stability accounts
for the frequent detection of desethylatrazine together with atrazine in natural
waters.
PMID- 10693005
TI - New monitoring system for ninety pesticides and related compounds in river water
by solid-phase extraction with determination by gas chromatography/mass
spectrometry.
AB - A new monitoring system was established for the determination of 90 pesticides
and 10 pesticide degradation products in river water. The pesticides consisted of
18 fungicides, 30 insecticides, and 42 herbicides. The pesticides were extracted
with a solid-phase, styrene-divinylbenzene copolymer, eluted with acetone,
hexane, and ethyl acetate, and determined by gas chromatography/mass
spectrometry. Overall recoveries ranged from 72 to 118%. The limits of detection
were 0.01-0.1 microgram/L. This system determines most of the pesticides used in
Japan and was successfully applied to practical monitoring of water polluted with
pesticides and related compounds.
PMID- 10693006
TI - Detection of pork in heat-processed meat products by monoclonal antibody-based
ELISA.
AB - An enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody to a
porcine thermal-stable muscle protein was developed for detection of pork in
cooked meat products. The assay specifically detects porcine skeletal muscle, but
not cardiac muscle, smooth muscle, blood, and nonmuscle organs. No cross
reactivity was observed with common food proteins. Validity of the assay was
evaluated with laboratory formulated and commercial meat samples. The detection
limit was determined as 0.5% (w/w) pork in heterologous meat mixtures. Overall,
intra- and inter-assay coefficients of variation were 5.8 and 7.9%, respectively.
The accuracy in analyzing market samples was 100% as verified by product labeling
and confirmed by a commercial polycolonal antibody test kit.
PMID- 10693007
TI - Rapid determination of Listeria monocytogenes by automated enzyme-linked
immunoassay and nonradioactive DNA probe.
AB - A rapid and reliable analytical method was developed to detect and confirm the
presence of Listeria monocytogenes in raw and partially processed foods. Forty
nine food samples (25 mixed cut vegetable salad, 12 smoked salmon, and 12 sterile
smoked salmon) were individually inoculated with high levels [10-100 colony
forming units (cfu)/25 g sample] and low levels (1-10 cfu/25 g sample) of L.
monocytogenes, and were screened using the Vitek Immuno Diagnostic Assay (VIDAS)
Listeria monocytogenes (VIDAS LMO)]. Positive test results were confirmed as L.
monocytogenes by nonradioactive DNA probe. All samples inoculated with high
levels of L. monocytogenes were detected by VIDAS and 96% were confirmed as L.
monocytogenes by DNA probe. VIDAS LMO detected 89% of samples inoculated with low
levels of L. monocytogenes, and 87% of these were confirmed as positive by DNA
probe. In addition, 12 other samples (4 from each of mixed cut vegetable salad,
smoked salmon, and sterile smoked salmon) were inoculated with high levels of L.
ivanovii, L. seeligeri, L. welshimeri, L. innocua, L. grayi, and L. murrayi.
Samples were assayed by the same protocol and all gave negative results. Compared
with the cultural method, the VIDAS LMO nonradioactive DNA probe combination is
highly specific, discriminates between L. monocytogenes and all other Listeria
species, and reduces analytical time.
PMID- 10693008
TI - Determination of histamine in tomatoes by capillary electrophoresis.
AB - An improved capillary electrophoresis assay for histamine in crude extracts was
developed and used to determine histamine levels in a selection of tomato fruits
and pastes. Performance in terms of reproducibility and sensitivity was optimized
by use of a high sensitivity detector flow cell, sodium hydroxide rinses, and a
voltage gradient. The method was linear down to 0.2 microgram/mL (signal-to-noise
ratio = 4:1), which was below the endogenous level in all samples.
PMID- 10693009
TI - Determination of aflatoxins in grains and raw peanuts by a rapid procedure with
fluorometric analysis.
AB - A rapid, quantitative, inexpensive, and efficient method was developed to
determine aflatoxins in corn, corn meal, popcorn, rice, wheat, cottonseed, and
peanuts. Samples are ground and extracted with methanol-water (80 + 20). A
portion of the extract is cleaned up by passage through a solid-phase separatory
column, 500 microL purified extract is derivatized with a bromine reagent, and
fluorescence of the solution is immediately quantified with a calibrated
fluorometer containing a broad wavelength pulsed xenon light source. This method
can quantify aflatoxin from 5 to 5000 ppb without dilution and was linear when
applied to samples of noncontaminated corn spiked at 0 to 5000 micrograms
aflatoxin B1/g. Correlation coefficients of the method with LC for multiple
analyses for corn (n = 34), cottonseed (n = 32), and peanuts (n = 11) were 0.999,
0.995, and 0.980, respectively. Individual analyses may be conducted in less than
5 min, and grouping of samples is unnecessary. The sensitivity of the method for
corn is 5 ppb and the fluorometer, under the operating conditions, has a limit of
detection of 0.6 ng aflatoxin B1.
PMID- 10693010
TI - Determination of fumonisins B1 and B2 in various maize products by a combined SAX
+ C18 column and immunoaffinity column.
AB - Fumonisins B1 and B2 were determined in 42 samples of different maize products
from the Swedish market by 2 different methods based on cleanup steps using an
immunoaffinity column and a combination of SAX + C18 columns, respectively. A
simple "precipitation step" was included before the samples were added to the
main column(s), giving less column clogging, fewer interfering peaks, and better
recoveries for the different sample matrixes. Recovery, repeatability, and
results from the survey showed comparable results with the methods. The limit of
detection for both methods was 5 micrograms/kg for fumonisin B1 and 10
micrograms/kg for fumonisin B2. All 7 maize chips analyzed and 6 of 8 popcorn
samples contained fumonisins (B1 + B2) with averages of 180 and 115
micrograms/kg, respectively. All other samples except a maize flour sample
contained little or no fumonisins.
PMID- 10693011
TI - Capillary gas chromatography/mass spectrometry with chemical ionization and
negative ion detection for confirmation of identity of patulin in apple juice.
AB - Gas chromatography/mass spectrometry (GC/MS) with negative ion chemical
ionization permits detection of underivatized patulin in apple juice extracts
while minimizing co-extractive responses. The technique has been used with a
variety of capillary columns in quadrupole, ion trap, and magnetic sector GC/MS
instruments to confirm presumptive findings of patulin in apple juice at
concentrations ranging from 68 to 3700 micrograms/L. The demonstrated ability to
use any of these 3 mass spectrometers and several capillary columns to confirm
the identity of patulin are significant strengths of the technique.
PMID- 10693012
TI - Determination of low levels of mite and insect contaminants in food and
feedstuffs by a modified flotation method.
AB - Extraneous material was separated from feed and food products by a modified
technique in which kerosene is used in a specially designed flotation flask. This
technique, although effective for analyzing feed and foods, presented limitations
in the analysis of finely powdered materials. Some procedural modifications and
an increased in the capacity of the flotation flask from 500 to 750 mL allowed a
larger sample weight (20 g) to be analyzed for mites, insect fragments, and
rodent hairs, with considerably reduced residue interference. In trials with a
variety of products seeded with known numbers of mites, average recovery was 83%.
Recoveries of 89% were obtained from flour samples seeded with insect fragments
and rodent hairs. A new process of suspending extracted mites in a mixture of
industrial methylated spirit (46%) and glycerol (54%) by volume was used to allow
rapid and more precise estimates of mite populations in heavily infested samples.
PMID- 10693013
TI - Determination of vitamin K in milk and infant formulas by liquid chromatography:
collaborative study.
AB - A simple procedure for determination of vitamin K1 was developed for routine
compliance monitoring of supplemented infant formula and measurement of
endogenous levels in milk and milk powders. Samples are digested with lipase and
extracted into hexane; and aliquot is evaporated, reconstituted in methanol, and
analyzed by reversed-phase LC. Post-column zinc reduction of phylloquinone
facilitates detection by fluorescence. The procedure was subjected to an AOAC
collaborative study involving 8 materials, each in blind duplicate, across the
range of 5-120 micrograms/100 g solids and including NIST 1846 reference
material. Thirty-three laboratories returned valid data which were then
statistically analyzed for outliers and precision parameters. Mean RSDR (%) was
6.53 (4.33-10.94), with a mean HORRAT value of 0.33 (0.23-0.43) and RSDr:RSDR
ratio of 0.74. K1 isomers (cis and trans) were aggregated with conventional C18
columns, but may be selectively estimated with use of the C30 column.
PMID- 10693014
TI - Determination of choline in milk and infant formulas by enzymatic analysis:
collaborative study.
AB - A collaborative study was conducted on a coupled enzymatic-spectrophotometric
method for the determination of choline in infant formula and milk powders.
Twenty-nine laboratories participated in the analysis of 8 blind duplicates over
the range of 45-175 micrograms/100 g sample. After the combined acid hydrolysis
phospholipase release of choline, incubation with choline oxidase in the presence
of peroxidase and phenol generates a quinoneimine chromophore with 4
aminoantipyrine. Following raw data screening, overall mean RSDR was estimated at
5.14% (range, 4.26-6.34%) with a HORRAT value of 0.91 (range, 0.76-1.00) and an
overall mean RSDr:RSDR value of 0.53 (range, 0.42-0.74). The method was also
compared with alternative independent analytical techniques for several of the
collaborative study samples.
PMID- 10693015
TI - Determination of egg proteins in food products by enzyme immunoassay.
AB - An enzyme-linked immunosorbent assay (ELISA) was developed to determine the
presence of egg proteins in foods. The polyclonal antibodies developed were
specific to whole egg proteins and did not cross-react with any of the 38 nuts,
legumes, or other common food ingredients tested. The concentrations of egg
proteins that will inhibit 50% of antibody-antigen binding, IC50, were 3-7 ng/mL,
and the linear range was 0.5-62.5 ng/mL. The detection limit was 0.2 ppm for
various foods. Recoveries ranged from 67 to 96%. The intra- and inter-assay
coefficients of variation in this procedure were 10-13% for ice cream spiked at
0.8 and 1.6 ppm. The ELISA has been applied to ice creams, noodles, pasta, and
breads. Egg proteins were identified in all declared egg products, and no false
positives were found.
PMID- 10693016
TI - Recovery and sporicidal resistance of various B. subtilis spore preparations on
porcelain penicylinders compared with results from AOAC test methods.
AB - Sporicidal test results obtained from carriers inoculated with 4 types of defined
Bacillus subtilis spore preparations were compared with the standard AOAC
sporicidal test using soil extract nutrient broth (SENB) B. subtilis 19659
spores. Recoveries of spores inoculated on penicylinders from B. subtilis clean
spores (washed and suspended in water) and B. subtilis 19659 spores inoculated
from culture filtrates according to the AOAC method were compared. Spores were
exposed to 6 concentrations (0.5-3.0% w/v) of glutaraldehyde in phosphate buffer
(pH 7.5) for 10 h. Concentrations were established by titrimetry and liquid
chromatography. Recoveries of surviving spores were determined for 3 types of
clean B. subtilis var. niger preparations, one clean B. subtilis 19659
preparation, and the SENB B. subtilis 19659 filtrates. Spore carriers, inoculated
by the standard AOAC protocol, resulted in as much as a 2-log number difference
in runs 1-12, but not more than 0.5 log number for each clean spore preparation.
The SENB spores varied most in resistance to glutaraldehyde, with no growth in
recovery media from 3 different batches of 1, 1.5, and 2% glutaraldehyde.
Separate batches of SENB preparations of B. subtilis 19659 were resistant and
destroyed by 1.0% glutaraldehyde, with 3.98 and 6.0 log numbers of spores on
penicylinders, respectively. Clean spore preparations of B. subtilis 19659 on
porcelain penicylinders were more resistant to glutaraldehyde than were SENB
spores. Nutrient agar/Mg/Ca and nutrient agar/Mg spore preparations of B.
subtilis var. niger showed the most uniform resistance to glutaraldehyde. Spores
with calcium added showed increased resistance to glutaraldehyde. B. subtilis
19659 spores from the Columbia broth spore preparation were the most resistant
and were recovered after exposure to 3.0% glutaraldehyde.
PMID- 10693017
TI - Element and radionuclide concentrations in food: FDA Total Diet Study 1991-1996.
AB - Food purchased throughout the United States during 1991-1997 under the U.S. Food
and Drug Administration's Total Diet Study (TDS) program were analyzed for
elements and radionuclides. The program is described with emphasis on food
analysis and quality control, including independent interlaboratory exercises.
Analytical results are summarized for Cd, Pb, Ni, As, Hg, Se, Cu, Zn, Mn, Fe, Mg,
Ca, P, K, and Na and for 137Cs, 131I, 106Ru, and 90Sr. Concentration data are
provided to expand the information base used to support assessments of the safety
and nutritive value of the U.S. food supply and for their potential use in food
composition databases. For selected foods, comparisons were made with past TDS
results and with those reported in the literature. An extensive listing of the
analytical data is available on the FDA CFSAN Website.
PMID- 10693018
TI - Determination of malathion, coumaphos, and fluvalinate residues in honey by gas
chromatography with nitrogen-phosphorus or electron capture detectors.
AB - A rapid, reliable, and inexpensive extraction method was developed to determine
acaricide residues in honey by gas chromatography (GC) with nitrogen-phosphorus
(NP) or electron capture (EC) detectors. Because of the high selectivity of the
NP detector, no interfering peaks were present and no cleanup was necessary. A
simple cleanup step is proposed for the GC-ECD analysis. Recoveries from spiked
honey samples ranged from 79 to 94.4%, with coefficients of variation of 0.3
18.5%. The quantitation limit obtained was 0.015 mg/kg for malathion, 0.020 mg/kg
for coumaphos, and 0.005 mg/kg for fluvalinate. The method was used to determine
the disappearance of malathion and coumaphos residues from honey samples
collected from beehives treated with these acaricides. The disappearance of both
acaricides was rapid and followed a first-order model for the duration of the
experiment.
PMID- 10693019
TI - Determination of six metals in galician red wines (in northwestern Spain) by
capillary electrophoresis.
AB - A simple technique is described for the routine simultaneous capillary
electrophoretic determination of 6 cations in wine. Separation was achieved on a
fused silica capillary column with a UV-Cat-1, alpha-hydroxysobutyric acid and 18
crown-6-ether buffer at pH 4.5 and indirect UV detection at 214 nm. The content
of magnesium, sodium, potassium, calcium, manganese, and lithium was determined.
The method is quantitative, with recoveries in the 92-102% range, and linear over
more than one order of magnitude. The precision is better than 2.5-3.4%. The
method is sensible, with detection limits between 0.01 and 0.06 mg/L. Twenty-five
red wines with a Certified Brand of Origin from Galicia (north-western Spain)
were analyzed by the proposed method. Various wines showed very similar
electrophoretic profiles, but significant quantitative differences were observed.
PMID- 10693020
TI - Optimized determination of iron in grape juice, wines, and other alcoholic
beverages by atomic absorption spectrometry.
AB - This paper describes a study of the different methods of sample preparation for
the determination of iron in grape juice, wines, and other alcoholic beverages by
atomic absorption spectrometry with electrothermal atomization; results are also
reported for the practical application of these methods to the analysis of
commercial samples produced in Spain. The methods examined include
dealcoholization and dry and wet mineralization treatment using different acids
and/or mixtures of them, both with and without heating. The sensitivity,
detection limit, accuracy, precision, and selectivity of each method were
established. The best results were obtained for wet mineralization with heated
acid (HNO3-H2SO4); the results for table wines had an accuracy of 97.5-101.6%, a
relative standard deviation of 3.51%, a detection limit of 19.2 micrograms/L, and
a determination limit of 32.0 micrograms/L. The method was also sufficiently
sensitive and selective. It was applied to the determination of iron in grape
juice, different types of wines, and beverages with high alcoholic content, all
of which are produced and widely consumed in Spain. The values obtained ranged
from 3.394 +/- 2.15 mg/L for the juice, 2.938 +/- 1.47 mg/L for the white wines,
19.470 +/- 5.43 mg/L for the sweet wines, 0.311 +/- 0.07 mg/L for the brandies,
and 0.564 +/- 0.12 mg/L for the anisettes. Thus, the method is useful for routine
analysis in the quality control of these beverages.
PMID- 10693021
TI - Pesticide residues on fruits and vegetables from Ontario, Canada, 1991-1995.
AB - For the 5-year period 1991 to 1995, 1536 vegetable and 802 fruit samples were
analyzed. The purpose of this study was to determine if pesticides were present
on Ontario-produced fruits and vegetables, and if so, to determine if residues
violated maximum residue limits (MRLs). Overall, 31.5% of the samples had no
detectable pesticide residues, whereas 68.5% contained one or more residues. Most
of the residues were present at very low concentrations; 48% of the detections
were < 0.1 parts per million (ppm), and 86% were < 1 ppm. However, violations of
MRL were observed in only 3.2% of the vegetables samples and 3.1% of the fruit
samples. In addition, 4.8% of the samples contained a "technical" violation, that
is, there was no specified MRL for the pesticide-commodity combination and the
residues exceeded 0.1 ppm. Of the detectable residues, 63% were < 10% of the MRL,
whereas 89% were < 50% of the MRL. More fruit samples (91.4%) had a detectable
residue, compared with vegetable samples (56.6%). Fruit is often treated close to
harvest or post harvest to ensure that wholesome produce reaches the consumer.
Forty-six percent of the samples contained 2 or more residues, and 2% of all
samples had more than 5 different pesticides detected; fruit samples tended to
have more multiple residues. The most frequently found pesticides were captan,
the dithiocarbamate fungicides, endosulfan, azinphos-methyl, phosmet, parathion,
and iprodione. These pesticides were also used in the greatest quantity for crop
production. Overall, the data agree fairly closely with those reported for the
U.S. Department of Agriculture Pesticide Data Program because the 2 programs have
similar analytical goals and objectives.
PMID- 10693022
TI - Quantitative relationship of application rate and pesticide residues in
greenhouse tomatoes.
AB - The association between application rate of a pesticide and its residue in ripe
tomatoes was studied. The average residue level (R) of any pesticide in ripe
tomatoes remained in quantitative relation to its dose (D), expressed by the
following regression equation: R = 0.24 D (mg/kg), where the numerical factor,
0.24, represents the average residue in mg/kg after application of 1 kg active
ingredient per hectare with relative standard deviation of 23%. Quantitative
association between these 2 factors enables evaluation of greenhouse tomato
growers with respect to their observation of Good Agricultural Practice rules and
the Plant Protection Act, obligatory in Poland since 1996, and thus may be a
reliable basis for the registration of new agrochemicals.
PMID- 10693023
TI - Selective determination of chromium (VI) in powdered milk infant formulas by
electrothermal atomization atomic absorption spectrometry after ion exchange.
AB - A previously developed method was adapted to the selective determination of
hexavalent chromium in powdered milk infant formulas. The species in
reconstituted milk was separated on an ion-exchange column, Chromabond NH2, and
measured by electrothermal atomization atomic absorption spectrometry. The
detection limit was 1.8 micrograms/L, and the linearity range under optimized
conditions was 1.8-50.0 micrograms/L. The precision values were 4.1 and 6.5% for
the analytical and overall procedures, respectively. The procedure was validated
by the method of standard additions (5.0, 10.0, and 25.0 micrograms/L), and the
recoveries were all > 93%. The developed method is sensitive, accurate, and
precise for determination of Cr(VI) in powdered milks. It was applied to the
determination of Cr(VI) in 20 commercial brands, i.e., 7 infant formulas, 5
follow-up milks, and 8 dietetic milks. The values found ranged from < 10 to 75
ng/g.
PMID- 10693024
TI - Speciation of iodide, iodine, and iodate in environmental matrixes by inductively
coupled plasma atomic emission spectrometry using in situ chemical manipulation.
AB - Dissolved iodine, iodide, and iodate are determined in environmental matrixes by
in situ chemical manipulation and inductively coupled plasma atomic emission
spectrometry (ICPAES). The method uses equipment commonly available to most
laboratories involved in environmental inorganic analysis. Total dissolved
iodine, iodide, and iodate are determined by ICPAES using iodine vapor
generation. Total iodine is determined directly by ICPAES after filtration. Total
dissolved iodide (I-) is oxidized in situ to iodine by the addition of sodium
nitrite in sulfuric acid in a simplified continuous flow manifold. Iodate is
determined by prereduction at the instrument before analysis by the in situ
oxidation ICPAES procedure. A standard nebulizer produces the gas-liquid
separation of the total iodine, which is then quantified by ICPAES at 206.16 nm.
The instrument detection limit for the iodine analysis was 0.04 microgram/mL.
Recoveries from seawater, saltwater, and freshwater standard reference materials
ranged from 85 to 118% and averaged 98%. For samples containing both iodine and
iodide, the total is determined with in situ oxidation, iodine is determined
without the oxidizing reagents, and iodine is calculated from the difference. For
samples containing all 3 species, pre-reduction is used and the iodine and iodide
concentrations are subtracted for quantitation of iodate. The analysis is
selective for these 3 species (I-, I2, and IO3). A group of 20-30 samples may be
analyzed and quantitated for all 3 individual, commonly occurring iodide species
in less than 1 h. The procedure is considerably faster than any other reported
techniques. This method is especially well-suited to the analysis of small
environmental samples.
PMID- 10693025
TI - Improved determination of mercury complex with Thiomicher's ketone by beta
correction spectrophotometry.
AB - Determination of the mercury complex formed with Thiomicher's ketone (TMK) was
improved by beta-correction spectrophotometry in the presence of a nonionic
surfactant at pH 5. The complex formed was Hg(TMK)2, and its true molar
absorptivity is reported for the first time: epsilon Hg(TMK)2(560) = 1.04 x 10(5)
L/mol.cm. In addition, the stability constant of Hg(TMK)2 was equal to 3.64 x
10(10) at an ion strength of 0.01 at 20 degrees C. Results from analyses of
wastewater samples showed that the relative standard deviations were < or = 8.3%,
and the recoveries of mercury ranged from 90 to 110%.
PMID- 10693026
TI - Liquid chromatographic determination of vanillin and related aromatic compounds.
AB - This paper describes a reversed-phase liquid chromatographic method for the
determination of vanillin, associated natural aromatic compounds and/or synthetic
precursors, ethyl vanillin, and coumarin, a commonly encountered adulterant in
nonbeverage and beverage alcohol products using a ternary gradient mobile phase.
The compounds were separated on a Nova-Pak C18 column by using water, methanol,
and tetrahydrofuran as the mobile phase. Measurements were made by using a
photodiode array detector at 275 nm. The choice of the mobile phase and the
column provides baseline resolution of vanillin and the associated aromatic
compounds commonly found in vanilla-flavoring material. Because this method
provides low-level detection/quantitation, it is suitable for the
characterization of vanilla flavoring materials that are currently added to
vanilla flavored beverage alcohol products.
PMID- 10693027
TI - Determination of 4-hexylresorcinol in shrimp by liquid chromatography with
fluorescence detection.
AB - A method was developed to determine 4-hexylresorcinol in shrimp meat. The
procedure is based on extraction of test portions with methanol followed by
liquid chromatographic analysis of the extracts, using a reversed-phase column
and fluorimetric detection (excitation: 280 nm, and emission: 310 nm). The
confidence interval of the recovery in working range of 1.5-2.5 mg/kg was 81.6 +/
0.8%. The relative standard deviation in the working range was 2.1%. Limits of
quantitation and detection were 6.59 and 1.98 ng/mL extract, respectively,
corresponding to 0.26 and 0.08 mg/kg in shrimp.
PMID- 10693028
TI - Assessing ADHD and comorbid disorders in children: the Child Behavior Checklist
and the Devereux Scales of Mental Disorders.
AB - Evaluated discriminant validity and clinical utility of selected subscales of the
Devereux Scales of Mental Disorders (DSMD; Naglieri, LeBuffe, & Pfeiffer, 1994)
and the Child Behavior Checklist (CBCL; Achenbach, 1991a) in 228 children
referred to a clinic for the evaluation and treatment of attention deficit
hyperactivity disorder (ADHD). The DSMD is a multiaxial behavior rating scale
that measures symptomatology for a broad range of child psychopathology as
described in the Diagnostic and Statistical Manual of Mental Disorders (3rd ed.,
rev. [DSM-R-III] and 4th ed. [DSM-IV]; American Psychiatric Association, 1987,
1994). Discriminant function analyses as well as sensitivity, specificity, and
predictive power analyses were computed to evaluate the discriminant validity and
clinical utility of selected DSMD and CBCL subscales for assessing ADHD,
oppositional defiant disorder (ODD), and anxiety disorders. Results indicated
that the DSMD compared very favorably with the CBCL in the ability to
discriminate between children with ADHD and those without ADHD and between
children with comorbid ODD and anxiety disorders and children who did not meet
criteria for these disorders. The DSMD Attention subscale may be somewhat better
at ruling in ADHD combined subtype (ADHD-C) and ADHD inattentive subtype (ADHD-I)
than the CBCL Attention Problems subscale, but the CBCL Attention Problems
subscale may have slightly better utility than the DSMD Attention subscale in
ruling out these subtypes. Both the CBCL and DSMD were more useful for ruling out
than for ruling in ODD and anxiety disorders.
PMID- 10693030
TI - Social functioning and emotional regulation in the attention deficit
hyperactivity disorder subtypes.
AB - Compared 16 children with attention deficit hyperactivity disorder (ADHD)
combined type (ADHD-C), 14 children with ADHD predominantly inattentive type
(ADHD-I), and 17 controls on parent and teacher ratings of social status and
performance, self-report of social knowledge and performance, and observations of
behavior on an emotional regulation task. Analyses revealed distinct patterns of
social dysfunction between ADHD subgroups. Children with ADHD-C were rated as
showing more aggressive behavior; furthermore, they displayed emotional
dysregulation characterized by high intensity and high levels of both positive
and negative behavior. In contrast, children with ADHD-I were perceived as
displaying social passivity and showed deficits in social knowledge on the self
report measure but did not evidence problems in emotional regulation. Regression
analyses revealed that social performance, emotional regulation, and, to a lesser
degree, social knowledge, were predictive of social status. The application of
these findings to understanding the nature of the social deficits in the ADHD
subtypes and directions for future research are discussed.
PMID- 10693029
TI - Parenting practices and child disruptive behavior problems in early elementary
school. Conduct Problems Prevention Research Group.
AB - Examined the hypothesis that distinct parenting practices may be associated with
type and profile of a child's disruptive behavior problems (e.g., oppositional,
aggressive, hyperactive). Parents of 631 behaviorally disruptive children
described the extent to which they experienced warm and involved interactions
with their children and the extent to which their discipline strategies were
inconsistent and punitive and involved spanking and physical aggression. As
expected from a developmental perspective, parenting practices that included
punitive interactions were associated with elevated rates of all child disruptive
behavior problems. Low levels of warm involvement were particularly
characteristic of parents of children who showed elevated levels of oppositional
behaviors. Physically aggressive parenting was linked more specifically with
child aggression. In general, parenting practices contributed more to the
prediction of oppositional and aggressive behavior problems than to hyperactive
behavior problems, and parenting influences were fairly consistent across ethnic
groups and sex.
PMID- 10693031
TI - Fears, worries, and scary dreams in 4- to 12-year-old children: their content,
developmental pattern, and origins.
AB - Investigated anxiety symptoms in normal school children 4 to 12 years of age (N =
190). The percentages of children reporting fears, worries, and scary dreams were
75.8, 67.4, and 80.5%, respectively, indicating that these anxiety symptoms are
quite common among children. Inspection of the developmental pattern of these
phenomena revealed that fears and scary dreams were common among 4- to 6-year
olds, became even more prominent in 7- to 9-year-olds, and then decreased in
frequency in 10- to 12-year-olds. The developmental course of worry deviated from
this pattern. This phenomenon was clearly more prevalent in older children (i.e.,
7- to 12-year-olds) than in younger children. Furthermore, although the frequency
of certain types of fears, worries, and dreams were found to change across age
groups (e.g., the prevalence of fears and scary dreams pertaining to imaginary
creatures decreased with age, whereas worry about test performance increased with
age), the top intense fears, worries, and scary dreams remained relatively
unchanged across age levels. An examination of the origins of these common
anxiety phenomena showed that for fears and scary dreams, information was the
most commonly reported pathway, whereas for worry, conditioning experiences were
more prominent.
PMID- 10693032
TI - Family processes as resources for African American children exposed to a
constellation of sociodemographic risk factors. Family Health Project Group.
PMID- 10693034
TI - Concurrent and longitudinal correlates of depressive symptoms among low-income,
urban, African American children. Family Health Project Research Group.
PMID- 10693033
TI - Disentangling the impact of low cognitive ability and inattention on social
behavior and peer relationships. Conduct Problems Prevention Re search Group.
AB - Examined the shared and unique contributions of low cognitive ability and
inattention to the development of social behavior problems and peer relationships
of children at the time of school entry. Kindergarten and first-grade assessments
of cognitive ability, inattention and prosocial and aggressive behavior were
collected for a multisite, normative sample. Sociometric assessments of peer
relationships were collected at the end of first grade. Cognitive ability and
inattention both contributed to the prediction of social behavior and peer
relationships. Low cognitive ability was particularly predictive of prosocial
skill deficits, and social behavior mediated the relation between cognitive
ability and social preference. Inattention predicted both prosocial skill
deficits and elevated aggressive-disruptive behavior problems. Behavior problems
partially mediated the relation between inattention and social preference.
Identified subgroups of children with elevated levels of inattention or low
cognitive ability showed different patterns of peer problems, with low acceptance
characteristic of the low cognitive ability (only) group and high dislike ratings
characteristic of the inattentive and inattentive/low-ability group. Implications
are discussed for the design of early intervention and prevention programs.
PMID- 10693035
TI - Proactive and reactive aggression in delinquent adolescents: relations to
aggression outcome expectancies.
AB - Investigated whether the relation between aggression and the tendency to expect
positive outcomes for aggressive behavior is specific to the proactive subtype of
aggression (as opposed to the reactive subtype). In a sample of 86 incarcerated
adolescent boys ages 13 to 18, we measured outcome expectancies for aggression
using audiotaped hypothetical vignettes. For each participant, staff members
completed proactive and reactive aggression rating scales. Regression analyses
revealed that the relation between aggression and outcome expectancies was indeed
specific to proactive aggression. Furthermore, this finding was supported
regardless of whether outcome expectancies were assessed using vignettes
describing proactive-aggressive behavior or those describing reactive-aggressive
behavior. We discuss these findings and argue that interventions to reduce
proactive or reactive aggression should differ from each other by addressing the
specific social cognitive processes involved in each type of aggression.
PMID- 10693036
TI - Role of the working alliance in the treatment of delinquent boys in community
based programs.
AB - Examined the role of the working alliance in the treatment of delinquent boys in
community-based residential programs, clarifying the relation between therapeutic
process and behavioral change. Horvath and Greenberg's (1989) Working Alliance
Inventory was used to assess the therapeutic alliance between youth and staff
after 3 weeks in treatment and again after 3 months. Achenbach's (1991) Child
Behavior Checklist (CBCL; Youth Self-Report [YSR] and Teacher Report Form [TRF])
and recidivism scores were used to assess treatment progress and outcome. Results
indicated that a positive working alliance assessed after 3 months in treatment
related to positive psychological changes and predicted lower rates of
recidivism. Unexpectedly, a positive working alliance assessed early in treatment
was associated with negative outcomes (increased internalizing and externalizing
symptoms and higher rates of recidivism). This finding suggests that for some
delinquent youth initially optimistic assessments may be prognostic of slow
progress or treatment failure.
PMID- 10693037
TI - Personal adjustment and perceptions of grandchild behavior in custodial
grandmothers.
AB - Examined parenting stress, depression, parenting satisfaction, and perceptions of
child behavior in 35 custodial grandmothers seeking outpatient psychological
services for their grandchildren ages 3 to 12. These clinic grandmothers reported
significantly greater stress and depression, less parenting satisfaction, and
more negative perceptions of their grandchildren's behavior than did 35 nonclinic
custodial grandmothers. Also, similar to a comparison group of 35 clinic mothers
and to the empirical literature on clinic parents, the clinic grandmothers'
personal adjustment (i.e., stress and depression) was related significantly to
their perceptions of their grandchildren's behavior. Thus, assessment of
custodial grandmothers' adjustment, as well as grandchild behavior, in clinical
settings appears warranted.
PMID- 10693038
TI - Assessing peer network and dyadic loneliness.
AB - Describes the Peer Network and Dyadic Loneliness Scale (PNDLS), a new scale
designed to assess simultaneously children's loneliness at multiple levels of
peer relationships. Specifically, this scale measures loneliness associated with
(a) lack of involvement in a social network and (b) the absence of a close dyadic
friendship. Employing a sample of 209 5th-, 6th-, and 7th-grade boys and girls,
the psychometric properties, interscale correlations, and preliminary validity
data for the new scale are examined. Analyses revealed good internal consistency
and a pattern of relationships with other loneliness, friendship quality, mutual
best friendship, and sociometric social preference variables supporting the
validity of the new scale.
PMID- 10693039
TI - Resilient and stress-affected adolescents in an urban setting.
AB - Studied 185 seventh- and eighth-grade inner-city adolescents. Participants were
categorized as low and high in exposure to stressors (stressful events or
neighborhood disadvantage) and externally exhibited competence (self-, teacher,
and school reports). We predicted that resilient (high-stress/high-competence)
and stress-affected (high-stress/low-competence) youth would differ across three
domains of hypothesized protective resources: internal resources (i.e., coping
skills, perceived competence), familial support, and extrafamilial support. We
also predicted that there would be an emotional cost to resilient youth in terms
of experiencing internalizing problems (depression, anxiety). There were direct
effects for stressor level on several protective resources; however, the
hypothesized protective resources did not discriminate resilient from stress
affected youth. Both Resilient and stress-affected youth experienced equivalent
levels of internalizing symptoms, and these groups' scores were higher than those
of low-stress participants. These results are possibly reflective of the effects
of chronic stressors.
PMID- 10693040
TI - On our way to integrated bioethics: clinical/organizational/communal.
PMID- 10693041
TI - The postmodern prescription: an antidote to hard boundaries and closed systems in
healthcare organizations.
PMID- 10693042
TI - Organizational ethics: creating structural and cultural change in healthcare
organizations.
PMID- 10693043
TI - Making the most of disequilibrium: bridging the gap between clinical and
organizational ethics in a newly merged healthcare organization.
PMID- 10693044
TI - Integrated ethics: synecdoche in healthcare.
PMID- 10693045
TI - All in the family--siblings but not twins: the relationship of clinical and
organizational ethics analysis.
PMID- 10693046
TI - Linking professional and economic values in healthcare organizations.
PMID- 10693047
TI - Actively engaging organizational ethics in healthcare: four essential elements.
PMID- 10693048
TI - Confidentiality as an organizational ethics issue.
PMID- 10693049
TI - Organizational ethics and sentinel events: doing the right thing when the worst
thing happens.
PMID- 10693050
TI - The "impossible patient": organizational response to a clinical problem.
PMID- 10693051
TI - Determination of organochlorine and organophosphorus pesticide residues in low
moisture, nonfatty products using a solid phase extraction cleanup and gas
chromatography.
AB - A multiresidue solid-phase extraction (SPE) method for the isolation and
subsequent gas chromatographic determination of organochlorine and
organophosphorus pesticide residues in low-moisture, nonfatty products is
described. Residues are extracted from samples with an acetonitrile/water
mixture. Cleanup of the extract is performed using graphitized carbon black and
anion exchange SPE columns, and analysis is performed by gas chromatography with
Hall electrolytic conductivity and flame photometric detection. Recovery data was
obtained by fortifying corn, oats and wheat with pesticides. The average
recoveries were 79-123% for eight organochlorine and 51-122% for 28
organophosphorus pesticide residues. The limit of quantitation for chlorpyriphos
was 0.05 ppm using the Hall electrolytic conductivity detector and < 0.005 ppm
using the flame photometric detector.
PMID- 10693052
TI - Fate of metolachlor under subirrigation in a sandy soil: a lysimeter study.
AB - A three-year field lysimeter study was conducted to investigate the role of
subirrigation systems in reducing the risk of water pollution from metolachlor (2
chloro-N-(2-ethyl-6-methlphenyl)-N-(2-methoxy-1-methylethyl)ace tamide). Nine
large PVC lysimeters, 1 m long x 0.45 m diameter, were packed with a sandy soil.
Three water table management treatments, i.e. two subirrigation treatments with
constant water table depths of 0.4 and 0.8 m, respectively, and a free drainage
treatment in a completely randomized design with three replicates were used. Corn
(Zea mays L.) was grown in each lysimeter, and at the beginning of summer of each
year metolachlor was applied, at the locally recommended rate of 2.75 kg a.i./ha.
Soil and water samples were collected at different time intervals after each
natural or simulated rainfall event. Metolachlor was extracted from these samples
and analyzed using Gas Chromatography. Results obtained in this three year study,
(1993-1995), lead to the conclusion that metolachlor is quite mobile since it
leached to a depth of 0.85 m below the soil surface quite early in the growing
season. Metolachlor concentrations decreased with depth as well as with time. The
shallower water table in the 0.4 m subirrigation treatment showed less residues
in the soil solution than that of other treatments. However, a mass balance
study, supported by an independent laboratory investigation, shows that water
table management, statistically, has no significant effect on the reduction of
metolachlor residues in sandy soils.
PMID- 10693053
TI - Sorption of imidacloprid and its metabolites on tropical soils.
AB - The sorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2
imidazolid-inimine ) (IMI) and its metabolites imidacloprid-urea (1-[(6-chloro-3
pyridinyl)-methyl]-2-imidazol-idinone) (IU), imidacloprid-guanidine (1-[(6-chloro
3-pyridinyl)-methyl]-4,5-dihydro-1H-imidazol-2-amine) (IG), and imidacloprid
guanidine-olefin (1-[(6-chloro-3-pyridinyl)methyl]-1H-imidazol-2-amine) (IGO) was
determined on six typical Brazilian soils. Sorption of the chemicals on the soil
was characterized using the batch equilibration method. The range and order of
sorption (Kd) on the six soils was IG (4.75-134) > or = IGO (2.87-72.3) > IMI
(0.55-16.9) > IU (0.31-9.50). For IMI and IU, Kd was correlated with soil organic
carbon (OC) content and CEC, the latter due to the high correlation between OC
and cation exchange capacity (CEC) (R2 = 0.98). For IG and IGO, there was no
correlation of sorption to clay, pH, OC or CEC due to the high sorption on all
soils. Average Koc values were IU = 170, IMI = 362, IGO = 2433, and IG = 3500.
Although Kd and Koc values found were consistently lower than those found in
soils developed in non-tropical climates, imidacloprid and its metabolites were
still considered to be slightly mobile to immobile in Brazilian soils.
PMID- 10693054
TI - Monitoring of pesticide residues in a cotton crop soil.
AB - This paper reports on the residues of methyl parathion (O,O-dimethyl O-4
nitrophenyl phosphorothioate), trifluralin (alpha, alpha, alpha-trifluoro-2,6
dinitro-N,N-dipropyl-p-toluidine), endosulfan [(1, 4, 5, 6, 7, 7-hexachloro-8, 9,
10-trinorborn-5-en-2, 3-ylenebismethylene) sulfite] and dimethoate (O, O-dimethyl
S-methylcarbamoylmethyl phosphorodithioate) in a cotton crop soil. Soil samples
(0-15 cm) were collected at different periods from the cotton crop farm and
subjected to Soxhlet extraction. The extracted material was analysed after clean
up by a HP5890 II gas chromatograph equipped with a 63Ni electron-capture
detector (ECD-63Ni) and fitted with a 25 m x 0.2 mm i.d. fused silica capillary
column [Ultra-2 (5% phenylmethyl polysiloxane)]. The recoveries of the pesticide
residues from the spiked control soil were determined after Soxhlet extraction
and C18 cartridges clean-up by using radiotracer techniques with the
corresponding 14C-pesticides. The results show that in the cotton crop soil the
pesticide residues under study were present in the range of 0.1 to 0.4 mg.kg-1.
Endosulfan was found to be rapidly degraded in the soil and formed a sulfate
metabolite.
PMID- 10693055
TI - Photocatalytic oxidation of xenobiotics in water with immobilized TiO2 on
agitator.
AB - A novel photocatalytic oxidation reactor, using Degussa P-25 TiO2 as a stationary
phase with a thickness of 1.5-2.0 um on the blades of agitator, was developed to
study the photocatalytic oxidation of xenobiotics. Particularly in this device,
separation of photocatalyst from the purified water after oxidation reaction was
not necessary, and no other aeration equipment was required to supply oxygen. To
examine the efficiency of this device, photocatalytic degradation of xenobiotic
organics such as carbofuran was studied as an example. Results indicated that
carbofuran could be degraded completely with mineralization efficiency of 20%
after 6 hours of oxidation under the imposed conditions. The mineralization rate
of carbofuran was found to follow the pseudo-first order reaction kinetics.
Moreover, the rate constant of mineralization was found to be proportional to
TiO2 film area and the square root of UV light intensity. These results implied
the mineralization efficiency of carbofuran could be improved through increasing
TiO2 film area and UV light intensity. Accordingly, this novel device showed
potential application for degrading xenobiotics in water.
PMID- 10693056
TI - Effect of dimethoate on the immune system of female mice.
AB - The functional status of the immune system of female mice exposed to a single
oral dose of dimethoate (16 mg/kg) was evaluated by assessing cell mediated and
humoral immune responses, in addition to the effect of dimethoate on spleen and
body weights after different time intervals. The data showed that dimethoate
caused a time-depended decrease in spleen weights in the absence of a change in
body weights. The immunologic effect of dimethoate to female mice produced a dose
dependent decrease in the number of the rosette forming cells (total and active
erythrocyte rosette). The ability of splenocytes to proliferation in response to
mitogens; phytohemagglutinin (PHA) for T cell and lipopolysaccharide (LPS) for B
cell were significantly decreased at the different times. As compared to control,
a significant decrease in serum total immunoglobulins (Ig) and IgM was found,
while IgG was non-significant deceased. Results of this study also revealed that
dimethoate caused a significant decrease in the number of plaque forming cell
(PFC/10(6) splenocytes) in a time dependent manner.
PMID- 10693057
TI - Investigation of metal ions binding of humic substances using fluorescence
emission and synchronous-scan spectroscopy.
AB - The binding site interactions of IHSS humic substances, Suwannee River Humic
Acid, Suwannee River Fulvic Acid, Nordic Fulvic Acid, and Aldrich Humic Acid with
various metals ions and a herbicide, methyl viologen were investigated using
fluorescence emission and synchronous-scan spectroscopy. The metal ions used
were, Fe(III), Cr(III), Cr(VI), Pb(II), Cu(II) and Ni(II). Stern-Volmer
constants, Ksv for these quenchers were determined at pH 4 and 8 using an ionic
strength of 0.1 M. For all four humic substances, and at both pH studied, Fe(III)
was found to be the most efficient quencher. Quenching efficiency was found to be
3-10 times higher at pH 8. The bimolecular quenching rate constants were found to
exceed the maximum considered for diffusion controlled interactions, and indicate
that the fluorophore and quencher are in close physical association. Synchronous
scan spectra were found to change with pH and provided useful information on
binding site interactions between humic substances and these quenchers.
PMID- 10693058
TI - Glutamine synthetase and protease enzyme activities and growth response of
ruminal bacterium Prevotella ruminicola strain B(1)4 to nitrogen source and
concentration.
AB - The objective of this study was to determine the effects of varying nitrogen
sources and concentrations upon glutamine synthetase and protease activities in
Prevotella ruminicola strain B(1)4. Based on growth response it appears that
ammonium chloride or pepticase limited P. ruminicola becomes nitrogen limited
when nitrogen concentration is at 0.5 mM. However, when casein was provided as
the sole source of nitrogen P. ruminicola becomes nitrogen limited at 2.5 mM.
Glutamine synthetase activity was measured from mid-log phase cells grown in
either nitrogen-limited or non-limited conditions. No activity was detectable in
the non-limited treatments. However, in the N-limited treatments, pepticase had
the highest activity (20.76 units), followed by ammonium chloride (18.72 units)
and casein (14.42 units). Protease activity assays indicated that nitrogen
limited cultures had higher proteolytic activity than non-limited cultures.
Moreover, these activities appeared to follow the same response pattern as the
previously observed glutamine synthetase activities. The results of this study
indicate that P. ruminicola strain B(1)4 protease activity may be influenced by
nitrogen concentration such that activity increases when nitrogen availability
decreases.
PMID- 10693059
TI - Preventing neural tube defects: a major success story, with a chapter yet to be
written.
PMID- 10693060
TI - Interventions to increase breast screening uptake: do they make any difference?
AB - BACKGROUND: Breast screening has an important role in improving survival from
breast cancer through early detection and treatment. Increasing uptake of
screening in areas of low uptake is important in improving the effectiveness of
the national screening programme. This review looks at which initiatives to boost
uptake have been successful. OBJECTIVE: To evaluate the effectiveness of the
different interventions to increase breast screening uptake. METHOD: A systematic
review of interventions to promote breast screening uptake was undertaken.
Studies were included if uptake was used as an outcome measure of the
intervention and if relevant to the UK screening programme. RESULTS: Twenty eight
studies were found among 25 citations. Interventions were grouped into "person
directed", "system directed", "social network directed", and "multistrategy"
categories. Most were person directed. These interventions were more likely to be
effective in boosting uptake, be simple in design, and to have been evaluated by
a randomized trial design. Evidence of effectiveness in the other groups is
limited both by the number of studies and the study designs. A summary of the
interventions reviewed is presented. CONCLUSIONS: Simple, brief, and effective
interventions exist to boost breast screening uptake. More complicated approaches
are not necessarily any more effective. These findings also have implications for
other population based screening programmes of the future. In inner city areas
the best approach to raising uptake rates is likely to be multistrategy.
PMID- 10693061
TI - Quantifying the decline in the birth prevalence of neural tube defects in England
and Wales.
AB - In England and Wales there has been a large decline in the birth prevalence of
neural tube defects (NTDs) from the early 1970s (reported rates of about 3.2 per
1000 births) to the present (0.1 per 1000 births in 1997). The reported number of
terminations of NTD pregnancies increased from 0.02 per 1000 in 1970 to 0.66 per
1000 in 1997, much too small an increase to explain the decline in NTD births.
Some underreporting of NTD terminations is recognised. We estimated its extent
using 1976-80 data on reported central nervous system (CNS) defect terminations
and NTD births in an analysis in which the true total number of NTD pregnancies
during this short period was assumed to have either remained constant or else to
have been changing by a constant amount per year. The estimate was that 56% of
NTD terminations were not reported as such and this fitted the data well. In 1997
the estimated birth prevalence of NTDs was 0.14 per 1000 births, a fall of 96%
since 1970. This 96% was apportioned as 40% due to antenatal screening and
termination of pregnancy and 56% due to a decline in incidence. Over the period
1970-97 there was an increase in dietary folate, and this will have at least in
part caused the decline in incidence of NTDs.
PMID- 10693062
TI - Current status of neonatal screening in China.
PMID- 10693063
TI - Comparison of the CAPAS and Ewing tests for screening of hearing in infants.
AB - OBJECTIVE: To study the similarities and differences between the non-automated
labour intensive Ewing hearing test and the less labour intensive automated CAPAS
(Compact Amsterdam Paedo-Audiometrical Screening) hearing test. SETTING: A
multicentre study in which all the children born in the eastern part of the
Netherlands between 1 January 1996 and 1 April 1997 were routinely screened for
hearing impairment at 9 months of age. METHODS: Differences and similarities
between the two methods were described for the proportion of children who failed
every test, the percentage of referred children, the yield of bilateral and
unilateral otitis media with effusion (OME), the positive predictive value of the
third test result, and the yield of persistent OME after 4-6 months' follow up at
an ENT department. RESULTS: 12,603 infants were screened with the CAPAS test and
17,496 with the Ewing test. There were differences between the CAPAS and Ewing
tests respectively in the proportions of children lost to follow up (10.1% v
15.2%), the proportions of children referred diagnosed with OME (59% v 81%), the
yield of bilateral otitis media with effusion (2.4% v 3.0%), and the yield of
persistent OME after 4-6 months' follow up (1.1% v 1.6%). CONCLUSIONS: The CAPAS
test is more practical than the Ewing test, but the non-automated Ewing test
seems to be more reliable and valid for detecting conductive hearing loss.
PMID- 10693064
TI - Should genetic analysis in newborn screening and a heterozygote test for
hyperphenylalaninaemia be recommended? An Italian study.
AB - OBJECTIVE: To determine whether the introduction of genetic analysis for
phenylalanine hydroxylase (PAH) deficiency into regional screening programmes can
be supported by the benefit-cost ratio. METHOD: Tests for the genetic PAH locus
were carried out in 151 patients with hyperphenylalaninaemia originally from all
of the Italian regions. PAH mutations were identified by extraction of genomic
DNA from leucocytes (whole blood in EDTA), PAH exon amplification was determined
by polymerase chain reaction, restriction enzyme analysis was carried out for
some recognised mutations, and DNA sequence analysis for the other mutations.
RESULTS: It was found that the eight most common mutations in the population
accounted for 49% of the mutant alleles, which is well below the required
standard for effective population screening (90%). CONCLUSIONS: Genetic screening
for PAH deficiency in Italy does not increase the sensitivity of the methodology
and the benefit-cost ratio, and thus provides no advantage, particularly as the
correlation between genotype and the metabolic phenotype needed to optimise
dietary intervention is still being studied.
PMID- 10693065
TI - The target plot: a new way of displaying the performance of a screening test.
AB - OBJECTIVES: To produce a graphical method to represent the performance of a
screening test that illustrates the prevalence of the disorder being screened
for, as well as its discriminatory potential. CONCEPT: A target plot was
constructed in which the risk of the disorder is represented by a series of
concentric circles of constant risk (isorisks) equivalent to specified false
positive rates, with the highest risk in the centre and lower risks spreading
outwards towards the circumference. Dots were drawn to represent cases of the
disorder; these were of a size such that their total area as a proportion of the
area of the whole target plot equalled the prevalence of the disorder in the
screened population. The discriminatory power of the test was seen as the
clustering of dots around the centre or bull's eye of the target. The detection
rate could be estimated as the proportion of dots which fell within the isorisk
corresponding to a specified false positive rate. APPLICATION: The target plot
was applied to second trimester antenatal screening for Down's syndrome using
different combinations of screening markers, and also to screening for ischaemic
heart disease using protein components of cholesterol (apolipoproteins A I and B
and Lp(a) lipoprotein), systolic blood pressure, and smoking status. DISCUSSION:
The efficacy of the different methods of screening for Down's syndrome is readily
apparent using the target plot, as is the poorer performance of screening for
ischaemic heart disease. CONCLUSIONS: The target plot is a simple and
quantitative way of displaying the performance of a screening test that may be
useful in teaching and educational material.
PMID- 10693066
TI - High mammographic breast density and its implications for the early detection of
breast cancer.
AB - OBJECTIVES: Women with high mammographic breast density are at increased risk of
breast cancer. This study explores whether these women should receive intensified
screening (more frequent screening or screening with alternative techniques that
increase the length of the preclinical detectable phase) to reduce further breast
cancer mortality. METHODS: Mathematical models were used to estimate the effects
of intensified screening in women with high breast density. The effects were
expressed as a reduction in the number of interval cancers. RESULTS: If women
with > 25% breast density (comprising about one fifth of all women) are screened
annually instead of biennially, an 18% reduction in the total number of interval
cancers can be expected. Screening these women with alternative screening
techniques biennially may produce the same reduction, provided that these
techniques double the mean lead time. CONCLUSIONS: By screening women with dense
breasts more intensively, many more breast cancers can theoretically be detected
at an early stage. The results provide an early indication of what may be
expected from screening strategies. Next, cost-benefit analyses are needed.
PMID- 10693067
TI - Identifying and screening patients at high risk of colorectal cancer in general
practice.
AB - OBJECTIVES: To determine the feasibility and acceptability of selecting patients
at risk of colorectal cancer by taking family histories by means of a postal
questionnaire. To determine if this information could be translated into simple
risk categories to guide subsequent management. SETTING: Patients aged between 30
and 69 years inclusive, registered with a mixed suburban and rural training
general practice in south west England. METHOD: A postal questionnaire survey
seeking demographic information and family history of colorectal cancer was sent
to all eligible patients. Personal risk of colorectal cancer was stratified
according to predetermined criteria. Risk assessment was modified if necessary
after the general practitioner conferred with a geneticist. Patients were
subsequently offered colonoscopy (high risk) or faecal occult blood testing
(intermediate risk). RESULTS: Response to the questionnaire was 84.7%. 250
patients had a family history of colorectal cancer, of whom 52 were assigned to
the high risk group, 104 to the intermediate group, and 94 to the low risk group.
The geneticist reassigned five intermediate risk patients to the high risk group.
Of 27 patients who had a colonoscopy, two were found to have an adenocarcinoma
and a further two adenomatous polyps. In the group given faecal occult blood
testing, two patients presented with colorectal cancer before being screened.
CONCLUSIONS: A postal questionnaire is feasible and acceptable for the collection
of information about a family history of colorectal cancer from patients in
general practice. The personal risk of developing the disease according to
standard criteria can be estimated and then managed by a simple protocol.
PMID- 10693068
TI - Implementation of screening as a public health policy: issues in design and
evaluation.
AB - OBJECTIVE: To propose principles of design and measures of effect for cancer
screening as a public health policy. MATERIAL: Finnish routine screening
programme with mammography. DESIGN: Evaluation of mortality from breast cancer by
before-after time trends among Finnish women, by geographical (by municipalities)
comparisons, and by intention to screen at an individual level with individual
controls who were cluster randomised and matched for age. OUTCOME MEASURES:
Standardised mortality ratios (SMRs) from breast cancer (total), SMRs from breast
cancers diagnosed during the screening programme (refined), deaths prevented,
prolongation of life for each breast cancer detected, for each death prevented,
for each compliant woman, for each screen, and for each invitation. Relative
prolongation of life--that is, time gained versus time spent. RESULTS: SMRs only
at an individual level with deaths from cancers diagnosed during the screening
programme and individually selected controls showed 24% protection, whereas the
other SMR measures were too crude or biased because of dilution and selection.
Prolongation of life varied from 15 years for each death prevented to two days
for each woman screened, with approximation for the prolongation relative to time
spent of 3 to 1. CONCLUSIONS: A public health policy should be introduced
gradually. Those not covered immediately by the policy serve as controls and they
should be randomly allocated. The most relevant outcome measure is prolongation
of life, and for public health purposes it should be given per unit of
intervention, such as screen or invitation, and also related to the time spent
for the intervention. Such gains are often small in a Western society, which
implies that medicine, including research, should focus more on other aspects of
life than length.
PMID- 10693069
TI - Assessment of complete blood count variations among workers exposed to low levels
of benzene.
PMID- 10693070
TI - Education for the practice of occupational medicine: knowledge, competence, and
professionalism.
AB - The multistep process of education is delineated by the sequential phases: (1)
Knowledge Transfer, (2) Competence Development, and (3) Professional Inculcation.
The realities of practice modes and curricular time constraints are important
determinants of the breadth and depth of the information provided in the
Knowledge Transfer process. Accordingly, it is proposed that Phase 1, the
Knowledge Acquisition Process, be organized into two components: (1) Core
Knowledge, requiring both significant breadth and depth; and (2) Augmentive
Knowledge, providing wide breadth and appropriate but variable depth. This
curricular organizing proposition recognizes that: (1) the wide breadth of
multiple stores of knowledge inherent in the practice of PM and EOM considerably
exceeds many other medical specialities; (2) the duration of training is
inherently shorter; and (3) its practitioners generally operate as members of
teams consisting of other professionals (e.g., attorneys, engineers, business
administrators, industrial hygienists, sociologists, psychologists). Obviously,
it is unreasonable to expect the members of such teams to each have comparable
depth and breadth of knowledge. A broad knowledge base, implicit in Augmentive
Knowledge, provides the capacity for recognition, understanding, and application
of capabilities brought by other professionals. Facilitating communications
between team members, each possessing a broad knowledge base, enhances the
effectiveness of the knowledge, competence, and professionalism of collaborative
efforts. Phase 2, Competency, consists of the coherent integration of multiple
stores of information applicable to the management of a clearly defined task with
a clearly measurable outcome. The accomplishment of true competency is not based
on the simple possession of multiple stores of knowledge; rather it depends on
the facility and effectiveness with which information bases are marshaled,
integrated, and communicated. Clearly, the effectiveness of this process
increases with its interaction; it is unreasonable to expect a significant degree
of competence immediately upon graduation from a training program. Phase 3,
Professionalism, and its basic ethos provides the governing context for the sound
application of competencies. Although it is difficult to teach, only with its
accomplishment can the educational process be considered whole, albeit never
complete.
PMID- 10693071
TI - Personal exposure to atmospheric polycyclic aromatic hydrocarbons in a general
adult population and lung cancer risk assessment.
AB - Personal exposure to nine particulate-phase atmospheric polycyclic aromatic
hydrocarbons (PAHs) was assessed among adult non-smoking volunteers in the
Grenoble, France, metropolitan area. Using Toxic Equivalency Factors, the
associated total atmospheric PAHs lifelong cancer risk was estimated. For 48
hours continuously, 38 subjects without specific occupational exposure to
combustion sources carried a PM2.5 particles personal exposure monitor while at
home, at work, commuting, or involved in other activities. One phase of the study
took place in summer; a second in winter. The monitor set was composed of a pump
with an airflow of 4 L.mn-1, a 2.5-micron cyclone, and Teflon filters. The PAH
concentrations were determined on seven PM2.5 filters by using high performance
liquid chromatography with fluorimetric detection. The predominant PAHs are
fluoranthene and indeno pyrene. According to the compound, the personal exposure
estimates ranged from 0.13 to 1.67 ng/m3 (yearly means). The average benzo(a)
pyrene value is 0.67 ng/m3 (95% confidence interval = 0 to 2.1 ng/m3). Winter
exposures were 3 to 25 times greater than summer exposures. The total PAHs lung
cancer lifelong risk is 7.8 10(-5) and is driven by exposure to benzo(a) pyrene.
Although these risk estimates are 2 to 3 orders of magnitude lower than those
associated with specific occupational exposures in the coal or smelter
industries, they are of public health concern because they are spread over large
urban populations. Further personal exposure studies in adult or children
populations are needed.
PMID- 10693072
TI - Association of physical activity at work with mortality in Israeli industrial
employees: the CORDIS study.
AB - The objective of this study was to evaluate the association of physical activity
at work with the risk of all-cause cardiovascular disease and cancer mortality.
The cohort consisted of 3488 male, Israeli, industrial employees who participated
in an 8-year follow-up study. During this period 129 deaths were recorded: 54
from cardiovascular disease, 47 from cancer, and 28 from other causes. Physical
activity at work was assessed at entry on a 4-point scale (none, light, medium,
and high). Potential confounding demographic, anthropometric, and socioeconomic
variables, and health habits including leisure time physical activity were
accounted for. We found that the hazard ratio of all-cause mortality in workers
with a high physical workload was 1.82 (95% confidence interval, 1.18 to 2.81)
compared with workers having a low workload. A similar trend was noted for
cardiovascular disease and cancer mortality. We concluded that a high physical
workload is associated with increased mortality rates. Future studies should
differentiate between leisure time and work time physical activity.
PMID- 10693073
TI - Melatonin metabolite levels in workers exposed to 60-Hz magnetic fields: work in
substations and with 3-phase conductors.
AB - Melatonin suppression by 50/60-Hz magnetic fields represents a plausible
biological mechanism for explaining increased health risks in workers. Personal
exposure to magnetic fields and ambient light, and excretion of the melatonin
metabolite 6-hydroxymelatonin sulfate (6-OHMS), were measured over 3 consecutive
workdays in electric utility workers. There was a magnetic field-dependent
reduction in adjusted mean nocturnal and post-work 6-OHMS levels among men
working more than 2 hours per day in substation and 3-phase environments and no
effect among those working 2 hours or less. No changes were observed among men
working in 1-phase environments. The results suggest that circular or elliptical
magnetic field polarization, or another factor linked to substations and 3-phase
electricity, is associated with magnetic field induced melatonin suppression in
humans.
PMID- 10693074
TI - Decrease of suppressor-inducer (CD4+ CD45RA) T lymphocytes and increase of serum
immunoglobulin G due to perceived job stress in Japanese nuclear electric power
plant workers.
AB - To clarify the effects of perceived job stress on the immune system, a cross
sectional study was conducted in 116 male Japanese workers of a nuclear electric
power plant (age, 20 to 39; mean, 31 years). Perceived job stress, i.e.,
psychological job demand, job control, worksite social support, and job strain,
was assessed by means of the Japanese version of the Job Content Questionnaire.
The job strain score was calculated as the ratio of the job demand score to the
job control score. Blood samples were taken from all workers, and numbers of T
and natural killer cell subpopulations, B lymphocytes, total lymphocytes and
white blood cells, and serum concentrations of immunoglobulins (IgG, IgM, IgA,
IgE and IgD) in their blood were measured. The workers were divided into higher
and lower strain groups according to their job strain scores. The number of CD4+
CD45RA+ T lymphocytes in the higher strain group having the job strain score of
0.5 or more (41 workers) was significantly smaller than that in the lower strain
group having the score of less than 0.5 (75 workers). In contrast, the serum IgG
concentration in the former group was significantly higher than that in the
latter group (analysis of covariance with age and smoking as covariates). Also,
the numbers of total CD4+ T and total T (CD3+) lymphocytes and of white blood
cells in the former group were significantly smaller than those in the latter
group. After controlling for age and smoking by the partial correlation
coefficient in all 116 workers, the number of CD57+ CD16+ natural killer cells
was inversely correlated with job demand and with job strain; the number of CD8+
T lymphocytes was positively correlated with worksite social support; and serum
IgG and IgM concentrations were positively correlated with job strain. It is
suggested that higher job strain decreases the number of CD4+ CD45RA+ T
lymphocytes in male Japanese workers but increases serum IgG concentrations.
PMID- 10693075
TI - Association between aminolevulinate dehydrogenase genotype and blood lead levels
in Taiwan.
AB - This study was designed to evaluate the association between the aminolevulinate
dehydrogenase (ALAD) genotype and blood lead levels in a general population
environmentally exposed to lead. This study population of 660 subjects was
secondarily sampled from the 3000 random samples of Taiwanese general population
to study the distribution of blood lead levels in the Taiwanese population. A
simple assay based on the polymerase chain reaction-restriction fragment length
polymorphism technique was used to determine the genotype of the ALAD gene. This
study found that most of the Taiwanese population was ALAD 1-1 (95.4%). Only 4.6%
(30 subjects) of population were found to be 1-2 or 2-2. It has been hypothesized
that the ALAD2 allele is associated with increased absorption of lead. This study
found that individuals with ALAD2 alleles had 20% higher blood lead levels than
persons with ALAD1 alleles (7.83 +/- 5.95 vs 6.51 +/- 5.03 micrograms/dL).
However, the difference was not statistically significant, even after adjustment
for other risk factors of environmental exposure. The result supports the
previous finding that individuals with ALAD2 allele had higher blood lead levels.
The small sample size and large amount of variation in our study may account for
the insignificant association.
PMID- 10693076
TI - Work-related deaths in West Virginia from July 1996 through June 1999:
surveillance, investigation, and prevention.
AB - The National Institute for Occupational Safety and Health's Fatality Assessment
and Control Evaluation model is used to identify and describe work-related deaths
in West Virginia. Through a statewide surveillance network, this model identifies
work situations at high risk for fatal injury, investigates selected causes
(falls, machinery-related, and logging), and formulates and disseminates
prevention strategies to reduce the frequency and impact of those injuries. A
total of 163 persons died from work-related injuries from July 1996 through June
1999. Ninety-three percent were male, the mean age was 42, and 80% were West
Virginia residents. Fatalities occurred most frequently in the
transportation/public utilities (32), manufacturing (24), construction (23), and
mining (23) industries. Extension of Fatality Assessment and Control Evaluation
methodology to nonfatal injuries may contribute to a clearer understanding of the
causes of these traumatic incidents and help to develop better prevention
measures.
PMID- 10693077
TI - A framework for addressing health issues in or near a manufacturing facility.
AB - Clustering of health events in or around industrial facilities sometimes leads to
worker and community concerns that plant management or local health professionals
must address. We provide an eight-step process to deal with these concerns
systematically. We emphasize the use of good scientific practices with managerial
oversight for effective worker and community communication. This process is
directed to plant management and the local health professional and emphasizes the
practical aspects of the investigation.
PMID- 10693078
TI - The pervasiveness of the illness suffered by workers seeking compensation for
disabling arm pain.
AB - Disability from work-related arm pain has become prevalent in several countries
in recent years. Many of these individuals present with chronic musculoskeletal
symptoms that, for lack of a more specific diagnosis, are often labeled as a
repetitive strain injury or cumulative trauma disorder. Indemnity for such
conditions can be contentious; many of these sufferers are involved in litigation
in their quest for financial compensation for temporary or permanent disability.
This article describes our experience with 103 patients referred to a Health
Reference Center for Workers for the management of repetitive strain injury.
Their illness is far more global than the work-related arm pain that such
labeling implies. From the total group, 73 fulfilled the American College of
Rheumatology Criteria for the Classification of Fibromyalgia Syndrome. This means
that they were suffering pain above and below the diaphragm, far from the arm
pain for which they were referred. These 73 patients were clinically and
psychologically indistinguishable from 165 patients followed in our clinic at the
Federal University of Sao Paulo, Rheumatology Division, who also fulfilled these
criteria but did not consider their illness work-related. This observation calls
for longitudinal investigations that might offer insights as to whether the more
global aspects of the illness are antecedent, coincident, or confounding aspects
of the illness experience labeled repetitive strain injury or cumulative trauma
disorder.
PMID- 10693079
TI - Injury and employment patterns among Hispanic construction workers.
AB - This article describes non-fatal injuries among Hispanic construction workers
treated at an emergency department from 1990 to 1998. Medical and interview data
were analyzed to evaluate and explain the workers' apparently inflated risk of
injury. The majority of the injured Hispanic workers were employed in the less
skilled trades. Compared with other injured workers, Hispanics had a higher
proportion of serious injuries and were disadvantaged in terms of training and
union status. With the exception of union status, these differences largely
disappeared after controlling for trade. The physical, financial, and emotional
consequences were more apparent 1 year later for injured Hispanics, even after
controlling for trade. These observations suggest that minority status is a
predictor of trade and that trade is a predictor of injury risk. In addition to
reducing injury hazards, interventions should address the limited employment and
union membership options that are available to minority workers in the
construction industry.
PMID- 10693080
TI - Association of pesticide safety knowledge with beliefs and intentions among farm
pesticide applicators.
AB - Although a number of health hazards associated with pesticide exposure have been
well documented, relatively little is known about the knowledge and health
beliefs that may influence pesticide handling. This study measured knowledge
levels concerning pesticide safety and precautionary handling among applicators
and examined relationships between knowledge scores and intentions to use
handling precautions, perceptions of pesticide safety peer norms, and perceived
self-efficacy to prevent personal exposure. Telephone interviews were conducted
with a randomly selected sample of 164 dairy farmers who were pesticide
applicators residing in Wisconsin (response rate = 77.4%). The percentage of
correct responses to 18 knowledge items ranged from 100% to 45.7%. Knowledge
levels were positively related to intentions, beliefs, and self-efficacy
regarding use of personal protective gear but were not significantly related to
risk perceptions and peer norms concerning pesticide safety.
PMID- 10693081
TI - A cohort mortality study among gas generator utility workers.
AB - An earlier cohort study tracked the mortality experience through 1988 of male
employees at five utility companies in the United States. Workers employed by the
Pacific Gas and Electric Company (PG&E) were part of that study, but results for
PG&E employees overall or for those involved in gas generator plant operations
where hexavalent chromium compounds were used in open and closed systems from the
1950s to early 1980s were not reported. To evaluate risk of lung cancer and other
diseases, a cohort of 51,899 PG&E male workers was followed for mortality from
1971 through 1997. Observed numbers of deaths were compared with those expected
based on rates in the general California population, with standardized mortality
ratios (SMR) and corresponding 95% confidence intervals (CI) calculated for the
total cohort and for subsets defined by potential for gas generator plant
exposure. A total of 10,591 deaths were observed, a number significantly less
than expected (SMR, 0.89; 95% CI, 0.87 to 0.91). No significant excesses of total
or specific cancers were observed, with SMR typically near or below 1.0. Lung
cancer mortality in the entire cohort was close to expected (SMR, 0.98; 95% CI,
0.92 to 1.05), with no excess detected among persons who worked (SMR, 0.81; 95%
CI, 0.35 to 1.60) or trained (SMR, 0.57; 95% CI, 0.12 to 1.67) at gas generator
facilities. Furthermore, risk of lung cancer did not increase with increasing
duration of employment or time since hire. The study thus provides no evidence
that occupational exposures at PG&E facilities resulted in increased risk of lung
cancer or any other cause of death. The results indicate that any chromium
exposures were of insufficient magnitude to result in increased risk of lung
cancer.
PMID- 10693083
TI - Total ankle replacement revisited.
AB - The surgical treatment of painful, end-stage ankle arthritis includes ankle
arthrodesis and total ankle replacement. In the past decade, total ankle
replacement has become a viable alternative to ankle arthrodesis. Modern implant
designs either involve a syndesmosis fusion and resurfacing of the medial and
lateral recesses of the ankle joint or the use of a 3-component, mobile bearing
implant. In limited clinical series, the early results of both these prosthetic
design approaches are encouraging. In selected patients, ankle arthroplasty is an
effective approach to relieving pain and improving function. The purposes of this
paper are to review the clinical results from total ankle replacement and ankle
arthrodesis; discuss indications, contraindications, design features,
postoperative rehabilitation, and initial results for the major current total
ankle designs; and present concepts for future total ankle development. In
particular, this article explores the advantages and concerns with 2 prevalent
but different design approaches. It also discusses future directions for total
ankle replacement.
PMID- 10693082
TI - Neonatal thyroxine level and perchlorate in drinking water.
AB - Environmental contamination of drinking water has been observed for perchlorate,
a chemical able to affect thyroid function. This study examines whether that
exposure affected the thyroid function of newborns. Neonatal blood thyroxine (T4)
levels for days 1 to 4 of life were compared for newborns from the city of Las
Vegas, Nevada, which has perchlorate in its drinking water, and those from the
city of Reno, Nevada, which does not (detection limit, 4 micrograms/L [ppb]).
This study is based on blood T4 analyses from more than 23,000 newborns in these
two cities during the period April 1998 through June 1999. No difference was
found in the mean blood T4 levels of the newborns from these two cities. Drinking
water perchlorate levels measured monthly for Las Vegas ranged during this study
period from non-detectable for 8 months to levels of 9 to 15 ppb for 7 months.
Temporal differences in mean T4 level were noted in both cities but were
unrelated to the perchlorate exposure. This study was sufficiently sensitive to
detect the effects of gender, birth weight, and the day of life on which the
blood sample was taken on the neonatal T4 level, but it detected no effect from
environmental exposures to perchlorate that ranged up to 15 micrograms/L (ppb).
PMID- 10693084
TI - Posterior tibial tendon dysfunction.
AB - Posterior tibial tendon dysfunction is the most common cause of acquired flatfoot
deformity in adults. Although this term suggests pathology involving only the
posterior tibial tendon, the disorder includes a spectrum of pathologic changes
involving associated tendon, ligament, and joint structures of the ankle,
hindfoot, and midfoot. Early recognition and treatment is the key to prevention
of the debilitating, long-term consequences of this disorder. Conservative care
is possible in the earliest stages, whereas surgical reconstruction and
eventually arthrodeses become necessary in the latter stages. The purpose of this
article is to review the symptoms, physical examination, radiological
examination, classification, and treatment of posterior tibial tendon
dysfunction.
PMID- 10693085
TI - Differential diagnosis of calf pain and weakness: flexor hallucis longus strain.
PMID- 10693086
TI - Effects of a tendo-Achilles lengthening procedure on muscle function and gait
characteristics in a patient with diabetes mellitus.
AB - STUDY DESIGN: Case report with repeated measures. OBJECTIVES: To describe the
effects of a tendo-Achilles lengthening (TAL) and total contact casting (TCC) on
wound healing, motion, plantar pressure, and function in a patient with diabetes
mellitus, peripheral neuropathy, neuropathic ulcer, and limited dorsiflexion
range of motion (DFROM). BACKGROUND: Limited DFROM has been associated with
increased forefoot pressures and skin breakdown. A TAL was expected to increase
DFROM and reduce forefoot pressures during walking, but the influence on muscle
performance and function was unknown. METHODS AND MEASURES: The patient was a 42
year-old man with a 20-year history of type 1 diabetes (NIDDM) and a recurrent
neuropathic plantar ulcer. Outcome measures were DFROM, isokinetic plantar flexor
muscle peak torque, in-shoe and barefoot peak plantar pressure, physical
performance test (PPT) score, and peak ankle and hip moments during walking
obtained from an automated gait analysis. All tests were completed pre-TAL, 8
weeks post-TAL (after immobilization in a TCC), and 7 months post-TAL. RESULTS:
The wound healed in 40 days. The TAL resulted in a sustained increase in DFROM (0
to 18 degrees). Plantar flexor peak torque was reduced by 21% 8 weeks after the
TAL compared with the torque before surgery but recovered fully at 7 months.
Seven months following TAL, in-shoe forefoot peak plantar pressure was reduced by
55%, barefoot pressure decreased by 14%, PPT score increased by 24%, peak ankle
plantar flexor moment remained decreased by 30%, and the peak hip flexor moment
increased by 41% during walking. CONCLUSION: For this patient, a TAL resulted in
short-term deficits in peak plantar flexor torque, but a 7-month follow-up showed
improvements in ankle DFROM, walking ability, and a decrease in forefoot in-shoe
peak plantar pressure.
PMID- 10693087
TI - Factors associated with ulceration and amputation in the neuropathic foot.
AB - The purpose of this paper is to review selected literature on the relationship of
neuropathy and other related factors in foot ulceration and lower extremity
amputation. There is strong evidence that sensory loss and mechanical stress are
the primary cause of foot ulceration and common factors in the pathway to lower
extremity amputation. Foot stress results from extrinsic factors such as footwear
and intrinsic factors such as deformity and limited joint mobility. Understanding
the interplay of these factors is valuable in identifying persons whose feet are
at risk, effectively preventing and treating foot ulcerations and ultimately
preventing lower extremity amputation.
PMID- 10693088
TI - Against the myth of evidence-based practice.
PMID- 10693089
TI - Measurement of posterior shoulder tightness.
PMID- 10693090
TI - The perinatal history of the Section on Perinatal Pediatrics.
PMID- 10693091
TI - Section on Perinatal Pediatrics: the 1980s to the 1990s.
PMID- 10693092
TI - On the 25th anniversary of the Section on Perinatal Pediatrics: historical
foresight.
PMID- 10693093
TI - Moral and ethical dilemmas in critically ill newborns: a 20-year follow-up survey
of Massachusetts pediatricians.
AB - OBJECTIVE: To replicate the 1987 survey, referring to the original 1977 study,
regarding opinions about treatment for critically ill neonates. STUDY DESIGN: A
long-term follow-up survey of American Academy of Pediatrics Massachusetts
membership, maintaining the 1987 instrument, was initiated. RESULTS: A notable
demographic shift in respondents from a majority of male practitioners in 1977
(89.6%), to 73% in 1987, to more equal numbers of men and women in 1997 (55% and
45%, respectively; p < 0.001; 1987 vs 1997) was apparent. Pediatricians' attitude
changes over the 20-year period were relatively modest and were statistically
associated with active medical intervention. In 1997, 75% of respondents rejected
review committees as mediators, a marked change from 1987. Regardless of
healthcare maintenance organization affiliations, 95% indicated that restrictive
fiscal policies would not affect decision-making. CONCLUSION: This study
indicates stability and consensus in pediatricians' attitudes toward active
intervention for critically ill neonates compared with 1977 and 1987 surveys and
reveals several claims to professional autonomy.
PMID- 10693094
TI - Ibuprofen use to reduce the incidence and severity of bronchopulmonary dysplasia:
a pilot study.
AB - OBJECTIVE: To assess the safety and efficacy of ibuprofen in reducing the
incidence and severity of bronchopulmonary dysplasia (BPD) in preterm infants.
METHODS: A total of 18 premature infants between 23 and 28 weeks' gestation were
studied. Ibuprofen (10 mg/kg of loading dose followed by 5 mg/kg every 12 hours)
was administered intravenously or orally to nine infants on respiratory support
at > or = 7 days of age and was continued until 28 days of life or until the
infants were spontaneously breathing room air, whichever occurred earlier.
Ibuprofen levels in plasma were measured in five of these infants. The outcome
variables (BPD, ventilatory parameters, and complications) in the study group
were compared with those in nine matched controls treated conventionally.
RESULTS: The incidence of BPD at 36 weeks postconceptional age was similar in
both groups (eight of nine in each group). The percentage of oxygen requirement,
the ventilatory efficiency index, and steroid use were also similar in both
groups. One infant in the study group, who was also receiving steroids and
aminophylline, developed gastrointestinal hemorrhage. Reversible renal failure in
one infant and necrotizing enterocolitis in another infant were seen at 4 and 21
days, respectively, after the last dose of ibuprofen. There was no difference in
the incidence of intraventricular hemorrhage between the two groups. Plasma
levels of ibuprofen at 3 hours after the first dose ranged from 10.3 to 36
mg/liter. Study infants tolerated the feeds better and achieved the full enteral
goal earlier than controls (p = 0.04). CONCLUSION: Although a trend toward less
ventilator and hospital days in the ibuprofen group was observed in this pilot
study, the differences were not statistically significant. The incidence of BPD
was similar in both groups. In the study group, two infants developed
gastrointestinal complications and a third infant experienced reversible renal
failure. The plasma ibuprofen levels were low. Further studies are needed to
assess the use of ibuprofen for the prevention and/or treatment of BPD in preterm
infants.
PMID- 10693095
TI - Does supine positioning increase apnea, bradycardia, and desaturation in preterm
infants?
AB - OBJECTIVE: The purpose of this study was to determine the effects of prone and
supine positioning on the cardiorespiratory stability of preterm infants with
apnea and bradycardia. METHODS: A total of 22 preterm infants with symptomatic
apnea and bradycardia (gestational age of 26.9 +/- 1.8 weeks and birth weight of
865 +/- 235 gm) were monitored for 24 hours (in four sequential 6-hour blocks)
for apnea, bradycardia, and oxygen desaturation in alternating positions (prone
or supine) following randomization. Postconceptional age at the time of study was
31.9 +/- 3.0 weeks. Respiratory rate, heart rate, and transcutaneous oxygen
saturation were continuously monitored. All episodes of apnea (> or = 10
seconds), bradycardia (< 100 beats per minute), and oxygen desaturation (< 90%)
were recorded on an event monitor. Episodes of apnea, bradycardia, and oxygen
desaturation were defined as clinically significant if the following criteria
were met: apnea, > or = 15 seconds; bradycardia, < 90 beats per minute; and
oxygen desaturation, < 80%. All other recorded episodes were considered mild. The
episodes were analyzed for statistical significance using the paired t-test.
RESULTS: No significant differences (p > 0.05) in the incidence of clinically
significant apnea, bradycardia, or desaturation between supine and prone
positions were seen in these preterm infants. CONCLUSION: Our results suggest
that the cardiorespiratory stability of preterm infants is not significantly
compromised by supine positioning.
PMID- 10693096
TI - Impact of infants born at the threshold of viability on the neonatal mortality
rate in Colorado.
AB - OBJECTIVE: To determine the contribution of infants born at the threshold of
viability (< 750 gm) on neonatal mortality in Colorado. STUDY DESIGN: For the
period of January 1991 to December 1996, all Colorado live births who expired
were evaluated for gestational age, birth weight, gender, hospital level of care,
age at time of death, delivery room resuscitation, mechanical ventilation,
medical and surgical complications, and serious malformations. RESULTS: Although
infants weighing < 750 gm represent only 0.31% of all live births, they account
for 46.3% of deaths. While those infants weighing < 500 gm and with a gestation
of < 24 weeks almost always died (94.7%), the majority born in the 500- to 745-gm
category (55.8%) survived. The vast majority (88.5%) of deaths occurred on the
first day of life. A total of 38.4% of births in which the infant weighed < 750
gm occurred outside bona fide regional perinatal centers. CONCLUSION: Future
attempts to reduce the Colorado neonatal mortality rate would best focus on the
500- to 750-gm weight group through the re-regionalization of high-risk perinatal
care.
PMID- 10693097
TI - Nitroglycerin for rapid tocolysis: development of a protocol and a literature
review.
AB - OBJECTIVE: A protocol for nitroglycerin (NTG) use based on experiences with
regard to new and previously described obstetric cases is presented. The efficacy
of NTG tocolysis for obstetric emergencies is clinically evaluated. STUDY DESIGN:
Hemodynamically stable parturients requiring acute tocolysis were treated with
intravenous NTG and closely monitored. Clinical information was subsequently
abstracted from medical records and compared with data from previous reviews.
RESULTS: Tocolytic treatment was successful in all cases (22 of 22, 100%).
Complications were clinically insignificant. The most common problem was
transient hypotension, which occurred in 9 of 22 (41%) cases. CONCLUSION: NTG is
an effective tocolytic with minimal complications, rapid onset, and a brief half
life. These characteristics favor its use during select obstetric procedures.
However, strict adherence to protocols for administration is advised.
PMID- 10693098
TI - Postnatal care in low-income urban African American women: relationship to level
of prenatal care sought.
AB - OBJECTIVE: This study examined the relationship between level of prenatal care
utilization and postnatal patterns of health care behavior among high-risk
minority women. The primary hypothesis was that prenatal care utilization
predicts subsequent levels of both the maternal and child health services used in
the postnatal period. METHODS: The study population consisted of 297 low-income
African American women who were recruited at delivery at an urban tertiary
medical center in the Mid-Atlantic region. They were followed monthly for 1 year
using telephone interviews to determine their use of maternal and child health
services. Four levels of prenatal care were identified retrospectively based on
reviews of health records and screening interviews using the Kessner Index. Data
regarding pregnancy outcomes, maternal postnatal visits, and well-child and acute
care child visits were collected. RESULTS: Women who sought inadequate or no
prenatal care had greater infant morbidity and mortality in the postnatal period
and significantly lower levels of attendance at maternal postnatal visits, well
child visits, immunization completions, and acute care visits. CONCLUSION: This
study confirms that the level of prenatal care is indicative of the level of
postnatal care women seek for themselves and their children in the first year
after delivery.
PMID- 10693099
TI - Pulmonary function and electrolyte balance following spironolactone treatment in
preterm infants with chronic lung disease: a double-blind, placebo-controlled,
randomized trial.
AB - OBJECTIVE: To study the effect of spironolactone on dietary electrolyte
supplementation, pulmonary function, and electrolyte balance in premature infants
with chronic lung disease. STUDY DESIGN: A double-blind, randomized, and placebo
controlled trial was designed to study two groups of low birth weight infants
with chronic lung disease at Pennsylvania Hospital. The placebo group received
chlorothiazide and a placebo, and the spironolactone group received
chlorothiazide and spironolactone during the 2-week study period. A two-tailed t
test was used to determine equivalence between the two groups. RESULTS: Pulmonary
compliance, resistance and tidal volume, serum sodium and potassium, and FIO2,
were not statistically different between the two groups. The need for sodium
and/or potassium chloride did not differ between the two groups, nor did the
quantity of each salt. CONCLUSION: The addition of spironolactone did not reduce
the requirement for supplemental electrolytes, nor did it improve pulmonary
mechanics or electrolyte balance.
PMID- 10693100
TI - Gastrointestinal function and growth in premature infants: is non-nutritive
sucking vital?
AB - OBJECTIVE: To determine the importance of non-nutritive sucking (NNS) in the
development of gastrointestinal function and growth in premature infants. DATA
SOURCES: A systematic computerized search of MEDLINE, the Cumulative Index of
Nursing in Allied Health Literature, Health, Best Evidence, and the Cochrane
Library was performed. STUDY SELECTION: The search yielded eight randomized
controlled studies relative to the outcomes of interest: sucking response,
gastric emptying, weight gain, and time to discharge from hospital. DATA
EXTRACTION: Relevant articles were selected using published criteria for
detecting clinically sound studies and evidence-based information. DATA
SYNTHESIS: NNS reduces length of hospitalization; however, its effect on the
other variables was inconclusive. CONCLUSION: There is a lack of agreement
concerning the outcomes of interest, apart from the positive contribution of
early hospital discharge. The studies were methodologically flawed, which
compromised validity and estimation of the treatment effect. NNS cannot be
currently recommended as a beneficial intervention.
PMID- 10693101
TI - Fatal neonatal Salmonella enteritidis sepsis.
AB - A case history of a fatal neonatal infection caused by Salmonella enteritidis
group D is reported. The baby deteriorated rapidly at 24 hours after birth with
clinical signs and symptoms of an acute abdomen. Bloody diarrhea led to a
tentative diagnosis of midgut volvulus or necrotizing enterocolitis. Autopsy and
bacteriologic investigation revealed sepsis by S. enteritidis group D. The same
organism was found in cultures taken from stool and vaginal swabs from the
mother. This clearly confirmed transmission of the infection during delivery.
PMID- 10693102
TI - Acute suppurative parotitis: uncommon presentation in a premature infant.
PMID- 10693103
TI - Subdiaphragmatic pulmonary sequestration: a case report with review of the
literature.
PMID- 10693104
TI - Placental pathology casebook. Serpentine aneurysms of the placenta with fetal
consequences.
AB - Two cases of placental surface vessel aneurysms are presented. One case was
associated with severe fetal intrauterine growth restriction and fetal
thrombocytopenia. The other case was associated with "molar transformation" of
placental villous tissue.
PMID- 10693105
TI - Special imaging casebook. High imperforate anus with enterolithiasis and
dysraphism with large meningomyelocele.
PMID- 10693106
TI - Fetal heart rate monitoring casebook. Amnioinfusion as fetal therapy.
AB - Amniotic fluid (AF) plays multiple roles in fetal development and wellbeing. A
global consideration of the possibilities of AF manipulation allows for the
maximum benefits to be derived from assessing and selectively augmenting AF in
clinical practice.
PMID- 10693107
TI - Mental health: a report of the Surgeon General.
PMID- 10693108
TI - Abortion: a psychiatric patient's right to choose.
AB - 1. Competent mentally ill patients should be allowed to terminate pregnancy. 2.
It is the responsibility of the staff to provide the patient with a safe,
supportive, and respectful environment. 3. Early and frequent staff processing
opportunities should be offered to clarify any underlying issues.
PMID- 10693109
TI - Use of physical restraints on hospitalized psychogeriatric patients.
AB - 1. When making decisions about the use of physical restraints, minimizing the
physical risk of patients was determined to be the most important obligation. 2.
Nurses' understanding and consideration of important factors that influence
restraint use are essential to its reduction. 3. Nurses should be aware of their
ethical responsibilities to older patients and their families. They must ensure
the patient's right to be informed and respect their dignity.
PMID- 10693110
TI - Nurses' burnout: an existential psychodynamic perspective.
AB - 1. According to Psychodynamic Theory the reason why most people choose a career
has to do with childhood experiences. 2. Both qualitative and quantitative data
suggest that nurses' burnout is caused by a failure to derive existential
significance from work. 3. Nurses' sense of significance seems to be related to
control and is often caused by childhood experiences of lack of control.
PMID- 10693111
TI - Resolving alcohol problems using an online self-help approach: moderation
management.
AB - As illustrated by the emergent MM approach discussed in this article, a paradigm
shift is occurring in relation to how alcohol problems are defined and managed.
Moreover, one of the most interesting aspects of this transformation is the way
in which similar belief systems are simultaneously emerging from divergent lay
and professional groups. In spite of this flurry of activity and optimism,
however, nurses should not embrace new frameworks and treatment strategies.
Rather, the charge to our discipline and others is to think critically, research
the effectiveness of newly proposed treatment approaches, and recommend and
implement promising strategies with discernment.
PMID- 10693112
TI - A nurse's guide to mental health assessment reference sources.
AB - 1. As the research base on psychological testing has proliferated across various
disciplines, a comprehensive review of the testing literature is recommended. 2.
In researching literature on psychological tests, nurses need to rely on
traditional print as well as electronic databases and Internet sites. 3. In
reviewing test items or in using a test, nurses need to be aware of test-user
qualifications and publisher copyright restrictions.
PMID- 10693113
TI - Interaction effects of emotional status and sexual abuse on adult sexuality.
AB - This study examined the additive, interaction effects of emotional status with
sexual abuse on adult sexual functioning and sexual responsibility. The Golombok
Rust Inventory of Sexual Satisfaction (GRISS; Rust & Golombok, 1986), the
Personality Assessment Inventory (PAI; Morey, 1991), and a questionnaire
regarding sexual experiences, number of unwanted pregnancies, number of unsafe
sexual partners, and sexual abuse history, were administered to 200 psychology
students. One hundred and forty-three participants were retained in the study.
Two-way multivariate analyses of variance (MANOVA) were conducted for the sexual
functioning variables (as measured by the GRISS), while two-way analyses of
variance (ANOVA) were conducted for the sexual irresponsibility variables (as
measured by the sexual experiences questionnaire). It was found that women who
have high anxiety scores on the PAI and have a history of sexual abuse reported
higher numbers of unwanted pregnancies, while sexual abuse history was not
associated with numbers of unwanted pregnancies for women with lower levels of
anxiety. Results were not significant, however, for the sexual functioning
variables. In addition, depression and alcoholism did not have interacting effect
on the association between sexual abuse history and any of the sexuality
variables. These results may suggest that the effects of sexual abuse on adult
sexuality may not be as pervasive as was once thought.
PMID- 10693114
TI - The Arizona Sexual Experience Scale (ASEX): reliability and validity.
AB - Although sexual dysfunction is common in psychiatric patients, quantification of
sexual dysfunction is limited by the paucity of validated, user-friendly scales.
In order to address this problem, the authors have developed the Arizona Sexual
Experiences Scale (ASEX), a five-item rating scale that quantifies sex drive,
arousal, vaginal lubrication/penile erection, ability to reach orgasm, and
satisfaction from orgasm. Possible total scores range from 5 to 30, with the
higher scores indicating more sexual dysfunction. This study assesses the
internal consistency, test-retest reliability, and convergent and discriminant
validity of the ASEX.
PMID- 10693115
TI - A study using Viagra in a mental health practice.
AB - The clinical responses of 58 men who were given Viagra between April and December
1998 in a psychiatric outpatient setting were tracked through 2 follow-up visits.
Four categories of success and 3 categories of failure are defined to describe
the outcomes. Although 43% had ideal outcomes--cure or uncomplicated drug
dependent successes--50% again were able to have intercourse and 63% experienced
improved erections. Seventeen percent of the original sample did not benefit from
the drug; 21% were lost to follow-up. This intent-to-treat study adds more
evidence of Viagra's effectiveness and further clarifies the need to focus on
psychodynamic considerations when trying to assist the majority of patients who
did not have ideal outcomes.
PMID- 10693116
TI - The female sexual response: a different model.
AB - Clarification of women's sexual response during long-term relationships is
needed. I have presented a model that more accurately depicts the responsive
component of women's desire and the underlying motivational forces that trigger
it. The variety of arousal/orgasm responses is also acknowledged. The purpose is
both to prevent diagnosing dysfunction when the response is simply different from
the traditional human sex-response cycle and to more clearly define subgroups of
dysfunction. The latter would appear to be necessary before progress in newer
treatment modalities, including pharmacological, can be made.
PMID- 10693117
TI - Cognitive distraction and women's sexual functioning.
AB - Past research on the role of cognitive distraction in sexual dysfunction
typically has focused on males and has been conducted in the laboratory using
artificial stimuli. In the current study, young adult women (N = 74) with coital
experience completed questionnaires regarding cognitive distraction and their
sexuality. Those women who reported greater cognitive distraction during sexual
activity with a partner also reported relatively lower sexual esteem, less sexual
satisfaction, less consistent orgasms, and higher incidence of pretending orgasm
even after the women's general affect, sexual desire, general self-focus, general
sexual attitudes, and body dissatisfaction were statistically controlled. Results
are discussed with regard to directions for future research and implications for
sex therapy.
PMID- 10693118
TI - Female analogies to perversion.
AB - Unlike the intrapsychic mechanism for self-esteem regulation in males as a basic
component of perversion--extrapsychically (compensationally) culminating in an
output of sexual impulses--a functional stabilization of the female self-concept
seems more likely if conflict drives were to be focused on reproductional aspects
and not on sexuality. It therefore seems more suitable to use a new expression in
linguistic analogy to perversion: "reproversion." The case history gives an
example of a clinical manifestation of "reproverse" symptom formation. The
general survey describes the main points of view in regard to clinically oriented
differentiation, i.e., intensity, ego-proximity in the personality structure, and
one's own self-acceptance within "reproverse" symptom formation. Underlying
personality disturbances are also discussed. The significance of reproversion is
relevant to many different specialized medical fields. This is explained in
conclusion, using the examples of denied pregnancy and infanticide at birth based
on initial empirical results.
PMID- 10693119
TI - College students' reasons for nonuse of condoms within dating relationships.
AB - Two hundred ten heterosexual undergraduates in dating relationships were surveyed
about reasons for not using condoms every time for vaginal and anal sex and for
increasing or decreasing condom use during their relationships. Half of the
respondents reported consistent condom use in the first month of their
relationships, while only 34% reported consistent condom use in the past month.
Subjective assessments of partner safety and the belief that sufficient measures
were being taken to avoid pregnancy were important reasons for condom nonuse.
Study results suggest that interventions should emphasize the importance of
objectively assessing HIV/STD risk before reducing condom use within
relationships. Interventions also need to provide additional information on the
riskiness of heterosexual anal sex.
PMID- 10693120
TI - [Models of radiation dispersion in medical laser tomographic system].
AB - The prospects for developing a new noninvasive medical diagnostic technique, such
as optical (laser) tomography of biological tissues largely depend on the
feasibility of designing an adequate mathematical model for the reconstruction of
images of the spatial structure of objects that are in the highly scattering
medium (HSM). The basic difficulty is that it is necessary to effectively
describe the physical properties and the propagation pattern of photons of
different types in such a medium. This review considers methods for describing
the distribution of laser ultrashort pulses in HSM with particular emphasis on a
new nonstationary two-flux model of radiation transfer.
PMID- 10693121
TI - [Possibilities of localization of the areas of myocardial depolarization
impairment using ECG high-frequency filtration].
AB - The paper deals with the physiological processes of myocardial depolarization and
repolarization and the way of solving the problems in the three-dimensional
plotting the disorders occur. It reviews basic papers on this problem. Attempts
are made to explain the occurrence of recorded late myocardial potentials and the
technical ways of identifying the areas of impaired myocardial depolarization are
proposed. This approach may be considered to be offers for designing new devices
and computer programmes having promising capacities to visualize ECG.
PMID- 10693123
TI - [Organizing diagnosis of parameters of limb loading during transosseous
osteosynthesis by external fixation devices].
AB - The presented system for compression-traction osteosynthesis (CTS) involves a
modified Ilizarov apparatus, a set of force and length detectors, PC controlled
measuring system, a set of cables and original software. The system apparatus
allows for angular displacement of bone fragments in the range of +/- 30 degrees
or 0-60 degrees and lateral displacement of bone fragment edges in the joint
along any azimuth in the ring plane. It was mathematically proved that the axial
and angular displacement of the two apparatus ring blocks relative to each other
can be described with three parameters: axial displacement of the ring center,
the ring deflection (turn) angle and the ring axis turn azimuth (angle). Formulas
for calculation of the displacement of three pairs of displacement control nuts
so the plane of the fracture displacement angle (correction) cross the axis of
the required ring plane turn azimuth (angle) were deduced for the reciprocal
angular displacement of the bone fractures. No additional removable joints or the
apparatus reconstruction for angular fracture displacement are needed. The CTS
features the display of the current reciprocal position of bone fragment axes
during the course of apparatus loading on the PC monitor.
PMID- 10693122
TI - [Comparative effectiveness of the use of hematological methods to analyze the
procoagulant activity of biological materials].
AB - Whether clinical hematological methods by employing two parameters: (plasma
recalcification time (PRT) and activated partial thromboplastin time (ACTT) can
be used to examine the procoagulant activity of the surface of biological
materials was comparatively studied. The method PRT was shown to be sensitive and
reproducible while ACTT failed to significantly record differences in the
procoagulant activities of various materials. The authors chose the optimal
protocol for evaluating the blood compatibility of biological materials: the
surface area/plasma volume ratio is more than 150 cm2/ml, the incubation time of
samples is no less than 180 sec at 37 degrees C and continuous mixing.
PMID- 10693124
TI - [EEG-Expert automated diagnostic system].
AB - The system is designed to describe and collect data of virtual analysis of
electroencephalograms (EEG), as well as to make an expert conclusion on the
functional status of the brain and its particular regions. The system includes
three parallelly operating systems in the form of a EEC visual analysis schedule
as a questionnaire. A programme provides recommendations for describing the
level, pattern, and magnitude of the changes detected. Another programme
automatically makes an EEC description and a conclusion on cerebral function in
conformity with the signs given in the questionnaire and displays them on the
screen and sends them to the print. The system may be used for practice in the in
and outpatient settings, for training and postgraduate training of young
specialists, and for researches.
PMID- 10693125
TI - [New technological means in medical diagnosis].
AB - Diagnostic methods using a Pulsar radar measuring computer unit have been
developed. The methods are based on the contactless recording of respiratory
parameters and pulse and they evaluate human body's functions in real time from
the measurements of the duration of cardiac rhythms and calculate the
differential function of their distribution and the spectrum of a cardiac
rhythmogram.
PMID- 10693126
TI - [Mathematical processing of human platelet distribution according to size for
determination of cell heterogeneity].
AB - The paper proposes a method for mathematical treatment of the distribution of
human platelets by sizes to detect the heterogeneity of cell populations. Its use
allowed the authors to identify three platelet populations that have different
parameters of size distribution. The proposed method opens additional vistas for
analyzing the heterogeneity of platelet populations without sophisticating
experimental techniques.
PMID- 10693127
TI - [Microwave technology in dental and eye prosthesis].
AB - The paper outlines the specific features of using microwave technologies in
dental and eye prostheses designed in Russia in 1992-1998. Thermal, microwave,
and combined polymerizations of plastic materials used in prosthesis are
compared. A Denta microwave unit is presented, which realizes a combined
microwave technology.
PMID- 10693128
TI - [Use of impedance measurements of the permeability of skin capillaries to
estimate the activity of tuberculous process].
AB - The paper considers whether a new impedance measurement technique can be used to
estimate the activity of the process. Following 6 hours of intradermal tuberculin
administration, the permeability of capillaries proved to be of the maximum
informative value, which provides not only a judgement of the tuberculous origin
of the disease, but evaluates the activity of the process, by allowing for the
inclusion of this technique into a package of diagnostic measures in patients
having the suspected origin of the disease.
PMID- 10693129
TI - Manganese in natural waters and earth's crust: its availability to organisms.
PMID- 10693130
TI - Manganese transport in microorganisms.
PMID- 10693131
TI - Manganese uptake and transport in plants.
PMID- 10693132
TI - Manganese metabolism in animals and humans including the toxicity of manganese.
PMID- 10693133
TI - Interrelations between manganese and other metal ions in health and disease.
PMID- 10693134
TI - The use of manganese as a probe for elucidating the role of magnesium ions in
ribozymes.
PMID- 10693135
TI - Mn2+ as a probe of divalent metal ion binding and function in enzymes and other
proteins.
PMID- 10693136
TI - Enzymes and proteins containing manganese: an overview.
PMID- 10693137
TI - Manganese(II) in concanavalin A and other lectin proteins.
PMID- 10693138
TI - Manganese-activated phosphatases.
PMID- 10693139
TI - Manganese(II) as a probe for the mechanism and specificity of restriction
endonucleases.
PMID- 10693140
TI - Role of the binuclear manganese(II) site in xylose isomerase.
PMID- 10693141
TI - Arginase: a binuclear manganese metalloenzyme.
PMID- 10693142
TI - The use of model complexes to elucidate the structure and function of manganese
redox enzymes.
PMID- 10693143
TI - Manganese(II)-dependent extradiol-cleaving catechol dioxygenases.
PMID- 10693144
TI - Manganese catalases.
PMID- 10693145
TI - Manganese peroxidase.
PMID- 10693146
TI - Manganese superoxide dismutase.
PMID- 10693147
TI - Mechanistic aspects of the tyrosyl radical-manganese complex in photosynthetic
water oxidation.
PMID- 10693148
TI - The polypeptides of photosystem II and their influence on manganotyrosyl-based
oxygen evolution.
PMID- 10693149
TI - The effects of early rearing environment on the development of GABAA and central
benzodiazepine receptor levels and novelty-induced fearfulness in the rat.
AB - We compared the effects of handling or maternal separation from the day following
birth until postnatal day 14 on behavioral responses to novelty and on GABAA and
central benzodiazepine (CBZ) receptor levels in the rat. As adults, handled
animals showed reduced startle responsivity, increased exploration in a novel
open field, and decreased novelty-induced suppression of feeding relative to the
handled (H) and/or maternal separation (MS) groups. As compared with handled
animals, both nonhandled (NH) and MS animals displayed: (1) reduced GABAA
receptor levels in the locus coeruleus (LC) and the n. tractus solitarius (NTS);
(2) reduced CBZ receptor sites in the central and lateral n. of the amygdala, the
frontal cortex, and in the LC and NTS; and (3) reduced levels of the mRNA for the
gamma 2 subunit of the GABAA receptor complex, which confers high affinity BZ
binding, in the amygdaloid nuclei as well as in the LC and NTS. Both the amygdala
and the ascending noradrenergic systems have been considered as critical sites
for the anxiolytic effects of benzodiazepines. These data suggest that early life
events influence the development of the GABAA receptor system, thus altering the
expression of fearfulness in adulthood.
PMID- 10693150
TI - Behavioral effects of central administration of the novel CRF antagonist
astressin in rats.
AB - Astressin, a novel corticotropin releasing factor (CRF) antagonist, has been
found to be particularly potent at inhibiting the hypothalamo-pituitary-adrenal
axis. The aim of the present study was to determine the effects in rats of
astressin in attenuating the anxiogenic-like response produced by social stress
and intracerebroventricular (ICV) CRF administration on the elevated plus-maze,
and ICV CRF-induced locomotor activation in the rat. Astressin significantly
reversed the anxiogenic-like response induced by both social stress and ICV
rat/humanCRF (r/hCRF) on the elevated plus-maze, but failed to block the effects
of r/hCRF-induced locomotor activity in a familiar environment. When these
results were compared to previous studies performed with the same paradigms using
other CRF antagonists, astressin showed effects similar to those of D-PheCRF(12
41) on plus-maze performance. However, contrary to alpha-helicalCRF(9-41) and D
PheCRF(12-41), astressin had no effect on CRF-induced locomotor activity. These
results suggest that astressin may have a unique anti-CRF profile compared to
previously tested antagonists.
PMID- 10693151
TI - Seasonal variation in CSF 5-HIAA concentrations in male rhesus macaques.
AB - Seasonal changes in cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA)
concentrations were assessed on multiple occasions in 103 free-ranging male
rhesus macaques (Macaca mulatta). At the time of sampling subjects ranged between
the ages of 2 and 6 years. CSF samples were collected between the hours of 0900
and 1600 throughout the Fall, Winter, and Spring from 1990 through 1994. Data
were analyzed in a general linear mixed model with random intercepts. Results
indicated that CSF 5-HIAA concentrations decreased with age. CSF 5-HIAA
concentrations were significantly increased in the Fall (October and November),
which is the height of the breeding season, with no evidence of differences
between Winter and Spring. There was also some evidence that the seasonal
variation in CSF 5-HIAA concentrations was blunted in younger, more immature
subjects.
PMID- 10693152
TI - Increased ACTH concentrations associated with cholecystokinin tetrapeptide
induced panic attacks in patients with panic disorder.
AB - Preclinical findings on the role of corticotropin releasing hormone (CRH) in
stress and anxiety, on the interaction of CRH and cholecystokinin (CCK) in
modulating anxiety, as well as the blunted corticotropin (ACTH) response to CRH
in panic disorder suggest that CRH may play a role in panic disorder. To further
characterize the role of the hypothalamic-pituitary-adrenocortical (HPA) system
in panic disorder, we compared patients with and without CCK tetrapeptide (CCK-4)
induced panic attacks. Twenty-four patients with panic disorder were given
injections of CCK-4 (25 micrograms). Panic attacks, psychopathological changes,
as well as ACTH and cortisol secretion were recorded. Fifteen of the 24 patients
experienced a panic attack after CCK-4. ACTH secretion was significantly higher
in the patients with CCK-4-induced panic attacks than in those without such
attacks. The patients without CCK-4-induced attacks had a brief but less
pronounced increase in ACTH concentrations. Cortisol concentrations were not
significantly increased after CCK-4 administration. The increased ACTH
concentrations suggest that the activation of the HPA system in CCK-4-induced
panic attacks plays a physiological role. CRH may be involved in experimentally
occurring and perhaps in naturally-occurring panic attacks as well.
PMID- 10693154
TI - Atrophy and high intensity lesions: complementary neurobiological mechanisms in
late-life major depression.
AB - The primary objective of our study was to examine the role of atrophy, high
intensity lesions and medical comorbidity in the pathophysiology of major
depressive disorder in the elderly (late-life MDD). Our sample was comprised of
51 patients with late-life MDD and 30 non-depressed controls. All subjects were
scanned on 1.5 tesla magnetic resonance imaging scanner (MRI) and absolute and
normalized measures of brain and lesion volumes were obtained and used for
comparison between groups. Patients with MDD had significantly smaller frontal
lobe volumes, together with larger whole brain lesion volumes when compared with
controls (p < .05). Whole brain lesion volumes correlated significantly (r =
0.41, p = .006) with overall medical comorbidity. The odds ratio (OR) for
existing MDD increases significantly with a decrease in frontal lobe volume and
an increase in whole brain lesion volumes (p < .05). Our findings suggest that
atrophy and high intensity lesions represent relatively independent pathways to
late-life MDD. While medical disorders lead to neuropathological changes that are
captured on MR imaging as high intensity signals, atrophy may represent a
relatively autonomous phenomenon. These findings have broad implications for the
pathophysiology of mood disorders and suggest that complementary neurobiological
processes may lead to cumulative neuronal injury thereby predisposing to clinical
depression.
PMID- 10693153
TI - Serotonin function following remission from bulimia nervosa.
AB - Abnormal serotonergic regulation in bulimia nervosa is thought to contribute to
recurrent binge eating, depressed mood, and impulsivity. To follow-up on previous
studies showing decreased neuroendocrine responses in symptomatic patients, this
study assessed serotonin-mediated prolactin responses in individuals who had
remitted from bulimia nervosa. Subjects included 21 women with a history of
bulimia nervosa and 21 healthy female controls, as well as an additional
comparison group of 19 women with current bulimia nervosa. Placebo-controlled
neuroendocrine response studies utilized a single oral dose (60 mg) of the
indirect serotonin agonist d,l-fenfluramine. For the bulimia nervosa remitted
group, the fenfluramine-stimulated elevation in serum prolactin concentration was
not significantly different from the response in healthy controls, but was
significantly larger than the response in patients with current bulimia nervosa
(p < .01). These findings suggest that diminished serotonergic neuroendocrine
responsiveness in bulimia nervosa reflects a state-related abnormality. The
results are discussed in relationship to recent reports indicating that some
alterations in central nervous system serotonin regulation may persist in
symptomatically recovered individuals.
PMID- 10693155
TI - Peripheral markers of serotonergic and noradrenergic function in post-pubertal,
caucasian males with autistic disorder.
AB - Some studies have suggested that disorders in the peripheral and central
metabolism of serotonin (5-HT) and noradrenaline may play a role in the
pathophysiology of autistic disorder. This study examines serotonergic and
noradrenergic markers in a study group of 13 male, post-pubertal, caucasian
autistic patients (age 12-18 y; I.Q. > 55) and 13 matched volunteers. [3H]
paroxetine binding Kd values were significantly higher in patients with autism
than in healthy volunteers. Plasma concentrations of tryptophan, the precursor of
5-HT, were significantly lower in autistic patients than in healthy volunteers.
There were no significant differences between autistic and normal children in the
serum concentrations of 5-HT, or the 24-hr urinary excretion of 5-hydroxy
indoleacetic acid (5-HIAA), adrenaline, noradrenaline, and dopamine. There were
no significant differences in [3H]-rauwolscine binding Bmax or Kd values, or in
the serum concentrations of tyrosine, the precursor of noradrenaline, between
both study groups. There were highly significant positive correlations between
age and 24-hr urinary excretion of 5-HIAA and serum tryptophan. The results
suggest that: 1) serotonergic disturbances, such as defects in the 5-HT
transporter system and lowered plasma tryptophan, may play a role in the
pathophysiology of autism; 2) autism is not associated with alterations in the
noradrenergic system; and 3) the metabolism of serotonin in humans undergoes
significant changes between the ages of 12 and 18 years.
PMID- 10693156
TI - Putamen mitochondrial energy metabolism is highly correlated to emotional and
intellectual impairment in schizophrenics.
AB - In a recent study, we demonstrated that cytochrome-c oxidase (COX), an indicator
of neuronal activity, is increased in several brain regions from chronic,
medicated schizophrenics. In the present study, to address the functional
significance of those findings, we have measured COX activity in a group of
schizophrenics in whom antemortem geriatric measures of motor, intellectual, and
emotional impairment had been assessed. COX activity in the putamen was strongly
negatively correlated with emotional (r = -.76; p < .005) and intellectual
impairment (r = -0.76; p < .005), but not with motor impairment (r = 0.01). No
significant correlations could be found in the frontal cortex, thalamus, caudate
nucleus, globus pallidus, mesencephalon, or nucleus accumbens. Dopamine D2
receptor density in the putamen, measured with [3H]raclopride, was elevated in
schizophrenics as compared to controls, as were Kd values. In contrast to COX
activity, D2 receptor binding was moderately, but significantly positively
correlated with intellectual impairment (r = 0.64; p < .05) but not with motor
impairment. Results expose a unique anomaly in the effects of neuroleptics in
terms of increasing neuronal signaling in the putamen, which may underlie a
reversal of cognitive deficits in schizophrenics, while at the same time,
elevating D2 receptor density that seems to be detrimental.
PMID- 10693157
TI - The effects of a sub-anaesthetic dose of ketamine on human selective attention.
AB - A growing number of studies demonstrate that antagonists of the N-methyl-D
aspartate (NMDA) receptors can induce a broad range of psychophysiological
anomalies in healthy subjects similar to those observed in schizophrenia. In this
study, the effect of a sub-anaesthetic dose of the non-competitive NMDA
antagonist, ketamine, on human selective attention was explored. It was
hypothesized that ketamine would induce in healthy subjects psychophysiological
anomalies that are commonly observed in schizophrenic patients, such as reduced
P300 amplitude and a reduction of both mismatch negativity (MMN) and processing
negativity (PN). In a double-blind randomized placebo-controlled design, healthy
male volunteers (n = 18) were challenged with a sub-anaesthetic dose of ketamine
(0.3 mg/kg i.v.) after which they were tested in a selective attention task. In
this task, two types of stimuli were evenly presented to the left or right ear:
standard tones (80%) and deviant tones (20%) of either 1000 or 1100 Hz. The
duration of a stimulus (95 dB) was 50 ms, the interstimulus intervals were
randomized between 1750 and 2150 ms. The volunteer was instructed to push a
button as quickly as possible after hearing the deviant tone in a specified ear.
Ketamine did not alter performance of the subjects: in both the placebo and drug
condition their reaction times for and percentages of hits and false alarms did
not differ. Ketamine did, however, reduce PN and the P300 amplitude (both in
general and to deviant stimuli in particular). However, no drug effect on MMN was
found. In addition, ketamine enhanced the N100 amplitude to deviant stimuli. In
conclusion, ketamine induces some of the attentional deficits in healthy controls
that are observed in schizophrenic patients. Consequently, reduced glutamatergic
activity in the brain may be involved in some of the symptoms of schizophrenia.
PMID- 10693158
TI - Assessing the efficacy of treatments for the deficit syndrome of schizophrenia.
AB - The primary, enduring negative symptoms found in some patients with schizophrenia
have become the focus of clinical treatment trials, but there has been no
consensus on the best methods for approaching this area. In future trials, a
number of issues need to be considered, including analytic strategies, the
limitations in instruments used to measure negative symptoms, and study design.
An appropriate design for establishing the efficacy of treatments for the deficit
syndrome is proposed.
PMID- 10693159
TI - Effects of atypical neuroleptics on sustained attention deficits in
schizophrenia: a trial of risperidone versus haloperidol.
AB - To help determine whether sustained attention deficits as measured with the
Continuous Performance Test (CPT) are stable vulnerability indicators of
schizophrenia, we compared the CPT performance of schizophrenic patients before
and after treatment with risperidone or haloperidol. In this double blind trial,
56 schizophrenic patients were randomly assigned to a 12-week regimen of either
risperidone or haloperidol, after a 1-week washout period. The patients undertook
two sessions of the CPT (undegraded and 25% degraded) twice, one at the end of
the washout period and the other at the end of the study. Thirty-eight patients
completed the study, 19 in each group. Both groups experienced significant
improvements in clinical symptoms, and the risperidone group showed no change in
the severity of extrapyramidal symptoms. Despite those improvements, the CPT
performance indexes did not change significantly from the beginning to the end of
the study. These findings indicate that sustained attention deficits might be
stable vulnerability indicators of schizophrenia.
PMID- 10693160
TI - Adrenergic and noradrenergic plasma levels in Lesch-Nyhan disease.
AB - Noradrenergic dysfunction and abnormality in monoamine oxidase (MAO) enzyme
activity have been reported previously in Lesch-Nyhan (LN) disease. This study
examines peripheral indices of adrenergic, noradrenergic, and MAO function in
children and young adults with LN disease (n = 11), and healthy subjects (n = 9).
Blood samples, collected in identical conditions prior to a positron emission
tomography (PET) study, were assayed for concentrations of epinephrine (EPI),
norepinephrine (NE), and 3-methoxy-4-hydroxyphenylglycol (DHPG) (which results
from the degradation of NE by monoamine oxidase type A [MAO-A]). The LN subjects
had significantly higher EPI levels by 245% (p < .00) and lower DHPG levels by
42% (p < .00) compared to the control group. No group differences were noted in
NE plasma levels. Cognitive function (IQ tested by Stanford Binet Intelligence
Scale) was associated with EPI in the LN group (r = 0.77, p = .009), but not in
the control group. The abnormally high EPI plasma concentrations may indicate
another biochemical dysfunction secondary to the absence of the HPRT enzyme in LN
patients. Such a biochemical deficit is likely to originate from the adrenal
medulla, which is the primary site of EPI synthesis. The adrenal medulla may be
directly affected by the absence of hypoxanthine guanine phosphoribosyl
transferase (HPRT) enzyme, or may receive inappropriately high descending
activation input from the brain. The abnormally low DHPG levels, in the context
of normal NE levels, indicates low MAO activity, either as a primary deficit, or
as secondary adaptive changes to spare NE levels that would otherwise be too low
for adequate noradrenergic function.
PMID- 10693161
TI - Increased temporal cortex ER stress proteins in depressed subjects who died by
suicide.
AB - Regulation of ER stress proteins, such as the 78-kilodalton glucose regulated
protein (GRP78) by chronic treatment with mood stabilizing drugs suggests that
this family of proteins may be involved in the pathophysiology of mood disorders.
Indeed, increased levels of GRP78, GRP94, and calreticulin, a third member of the
ER stress protein family, were found in temporal cortex of subjects with major
depressive disorder who died by suicide compared with controls and subjects who
died by other means. No such differences were found in subjects with other
psychiatric disorders such as bipolar disorder or schizophrenia. These data
suggest a potential role for ER stress proteins in severe depression that merits
further study.
PMID- 10693162
TI - Changes in nutritional, functional, and inflammatory markers in advanced
pancreatic cancer.
AB - Weight loss and the acute-phase response have been associated with poor quality
of life and survival in advanced pancreatic cancer; however, little information
is available on changes in these factors over time and their interrelationships.
This study examined changes in weight, Karnofsky performance status, C-reactive
protein (CRP), and serum albumin in 25 patients with advanced pancreatic cancer
given supportive symptomatic treatment only. Patients were assessed at
approximately monthly intervals on a total of 70 occasions, allowing assessment
of changes over 37 intervals. Overall, patients had a median weight loss of 2.3
kg/28 days. Median CRP levels rose by 15 mg/l, and serum albumin fell by 1 g/l on
average over 28 days. Karnofsky performance status fell by 4 points every 28
days. The nine patients assessed close to death were compared with the 13
assessed close to diagnosis. The increase in CRP level and fall in weight and
performance status were significantly greater within eight weeks of death than
within eight weeks of diagnosis. Among patients close to diagnosis, 13% had an
elevated CRP compared with 100% of those close to death. In multivariate
analysis, Karnofsky performance status was significantly associated with percent
weight loss and CRP levels. These data further implicate the acute-phase protein
response as being associated with the progressive weight loss seen in patients
with advanced pancreatic cancer. Changes appear to accelerate close to death.
Moreover, the development of cachexia is associated with a reduction in patients'
functional capacity.
PMID- 10693163
TI - Vegetables, fruits, and related nutrients and risk of breast cancer: a case
control study in Uruguay.
AB - To evaluate whether the protective effect associated with vegetables and fruits
in breast cancer could be explained by nutrients and bioactive substances present
in these plant foods, we carried out a case-control study in Uruguay including
400 cases and 405 controls. The intake of vegetables, fruits, and related
nutrients was estimated with a food frequency questionnaire on 64 food items.
This questionnaire allowed the calculation of total energy intake, and nutrients
were calorie adjusted by the residuals method. Odds ratios for study variables
were estimated by unconditional multiple logistic regression. Total vegetable,
total fruit, dietary fiber, vitamin C, vitamin E, lycopene, folate, and total
phytosterol intakes were inversely associated with breast cancer risk [4th
quartile odds ratio for total vegetable intake = 0.41, 95% confidence interval =
0.26-0.65, p (for trend) = 0.004]. The association with total vegetable intake
was not independent of lycopene intake. The results related to vegetable and
nutrient intakes are consistent with antioxidant and antiestrogenic effects. This
could be mediated, among other nutrients, by dietary fiber and lycopene intake.
The role of other unmeasured phytochemicals, correlated with dietary fiber and
lycopene intakes, cannot be ruled out.
PMID- 10693164
TI - Effects of long-term treatment of colon adenocarcinoma with crocin, a carotenoid
from saffron (Crocus sativus L.): an experimental study in the rat.
AB - We used an experimental model in the rat to examine the effects of long-term
treatment with crocin, a glycosylated carotenoid from the stigmas of the saffron
crocus, on colon cancer. BD-IX rats were divided into four groups: Groups G1 and
G2, designated "cancer groups," were used to study the effects of crocin on the
progression of colon cancer, and Groups G3 and G4, designated "toxicity groups,"
were used to study the effects of the treatment on metabolic processes and the
parenchyma. DHD/K12-PROb cells were injected subcutaneously into the chest of
Group G1 and G2 animals. From 1 to 13 weeks after inoculation, animals in Groups
G2 and G4 received a weekly injection of crocin (400 mg/kg body wt s.c.). Animals
in Groups G1 and G3 received no treatment. In addition, lines of animal and human
colon adenocarcinoma cells (DHD/K12-PROb and HT-29) were used to perform assays
in vitro to examine the cytotoxicity of crocin. Life span was extended and tumor
growth was slower in crocin-treated female rats, but no significant antitumor
effect was found in male rats. Acute tubular necrosis was found in all kidney
samples from crocin-treated animals, but slight signs of nephrotoxicity were
found by biochemical analysis of the serum. In assays in vitro, crocin had a
potent cytotoxic effect on human and animal adenocarcinoma cells (HT-29 and
DHD/K12-PROb cells, 50% lethal dose = 0.4 and 1.0 mM, respectively). Treated
cells exhibited a remarkable loss of cytoplasm and wide cytoplasmic vacuole-like
areas. In conclusion, long-term treatment with crocin enhances survival
selectively in female rats with colon cancer without major toxic effects. The
effects of crocin might be related to its strong cytotoxic effect on cultured
tumor cells.
PMID- 10693165
TI - Longitudinal study of weight, appetite, performance status, and inflammation in
advanced gastrointestinal cancer.
AB - There is increasing evidence that, in most patients with advanced cancer, weight
loss is associated with an inflammatory response. To examine the temporal
relationship between weight loss, appetite, performance status, and the
inflammatory response, 50 patients with advanced gastrointestinal cancer with
weight loss were observed for six weeks. Patients were grouped according to
whether they had lost weight (> 3%, n = 16), were weight stable (< 3% change, n =
25), or gained weight (> 3%, n = 9). At baseline, the group that subsequently
lost weight had lower albumin and higher C-reactive protein concentrations (p <
0.05). On follow-up, there was an increase in C-reactive protein concentration
and reductions in triceps skinfold thickness and Karnofsky performance status in
the weight-losing group (p < 0.05). In contrast, Karnofsky performance status was
improved in the group that gained weight (p < 0.05). Over the six to eight weeks,
there was a difference in the changes of triceps skinfold thickness (p < 0.05)
and Karnofsky performance status (p < 0.01) between the two groups. These results
suggest that loss or gain of > 2.5 kg over a six- to eight-week period is
required to produce a significant alteration in performance status in weight
losing patients with gastrointestinal cancer. Moreover, the results suggest that
the presence of an inflammatory response is associated with further weight loss
and the deterioration of performance status.
PMID- 10693166
TI - Decreased growth of human prostate LNCaP tumors in SCID mice fed a low-fat, soy
protein diet with isoflavones.
AB - Epidemiological studies suggest that high intake of dietary fat is a risk factor
for the development of clinical prostate cancer. Soy protein has also been
proposed to play a role in the prevention of prostate cancer, and one of the
isoflavones in soy protein, genistein, inhibits the growth of human prostate
cancer cell lines in vitro. This study was designed to evaluate whether altering
dietary fat, soy protein, and isoflavone content affects the growth rate of a
human androgen-sensitive prostate cancer cell line (LNCaP) grown in severe
combined immunodeficient (SCID) mice. SCID mice were randomized into four dietary
groups: high-fat (42.0 kcal%) + casein, high-fat (42.0 kcal%) + soy protein +
isoflavone extract, low-fat (12.0 kcal%) + casein, and low-fat (12.0 kcal%) + soy
protein + isoflavone extract. After two weeks on these diets, the mice were
injected subcutaneously with 1 x 10(5) LNCaP tumor cells and placed in separate
cages (1 mouse/cage) to strictly control caloric intake. Isocaloric diets were
given 3 days/wk, and tumor sizes were measured once per week. The tumor growth
rates were slightly reduced in the group that received the low-fat + soy protein
+ isoflavone extract diet compared with the other groups combined (p < 0.05). In
addition, the final tumor weights were reduced by 15% in the group that received
the low-fat + soy protein + isoflavone extract diet compared with the other
groups combined (p < 0.05). In this xenograft model for prostate cancer, there
were statistically significant effects on tumor growth rate and final tumor
weight attributable to a low-fat + soy protein + isoflavone extract diet.
PMID- 10693167
TI - Colon cancer is induced by a single low dose of azoxymethane in fasted-refed
rats.
AB - We reported previously that fasting-refeeding enhanced the growth of
preneoplastic lesions in the colon of rats induced by 20 mg/kg of azoxymethane
(AOM). Here we studied whether fasting-refeeding could also affect 1) the
induction of colon cancer by the same dose of AOM and 2) the induction of foci by
lower doses of AOM that do not induce foci in fully fed rats. Fully fed and
fasted-refed rats were given AOM by single subcutaneous injection, and the
development of foci or tumors was evaluated three months or one year later. The
results of the long-term carcinogenesis experiments showed that the total
incidence of tumors was increased in the fasted-refed rats. Moreover, although
fully fed rats developed foci only when injected with 7.5, 10, or 20 mg/kg of the
carcinogen, a significant number of foci were also induced by 5 mg/kg in fasted
refed rats. The crypt multiplicity of foci was also higher when rats were exposed
to fasting-refeeding, even when the number of foci was unchanged. These data
suggest that growth perturbations induced by fasting-refeeding lead to the
development of preneoplastic lesions with doses of AOM too low to trigger foci in
fully fed rats and produce enhanced sensitivity to the development of intestinal
tumors.
PMID- 10693168
TI - High dietary iron enhances oxidative stress in liver but does not increase
aberrant crypt foci development in rats with low vitamin E status.
AB - The purpose of this study was to examine the effects of high-iron and low-vitamin
E diets on lipid peroxidation and aberrant crypt foci (ACF) development in rats.
In a 2 x 2 x 2 factorial design, male Sprague-Dawley rats were fed 45 or 450 mg
Fe/kg diet (adequate and high iron, respectively) and 15 or 100 IU vitamin E/kg
diet (low and adequate vitamin E, respectively) for three weeks, when they
received saline or azoxymethane (15 mg/kg for 2 wk). Diets were continued for an
additional six weeks. Serum alpha-tocopherol concentrations in rats fed low
vitamin E diets were decreased to 30% of concentrations observed in rats fed
adequate-vitamin E diets (p < 0.0001). Also, serum alpha-tocopherol
concentrations tended to be lower in rats supplemented with iron (p < 0.08).
Lipid peroxidation in liver was significantly elevated by high-iron diets after 3
and 10 weeks of treatment, but lipid peroxidation in colonic mucosa was not
altered by dietary iron or vitamin E. The total number of ACF and number of large
ACF (> or = 4 aberrant crypts/focus) were not significantly altered by iron or
vitamin E intakes. However, the size distribution of ACF was slightly altered,
such that iron-supplemented rats had 12% more ACF with two crypts per focus (p <
0.02) than rats fed adequate-iron diets. Our data suggest that high-iron diets
enhanced oxidative stress in liver, but not colon, of rats fed low-vitamin E
diets. Furthermore, a high-iron diet does not increase the total number of ACF,
even when vitamin E status is low.
PMID- 10693169
TI - A probiotic strain of L. acidophilus reduces DMH-induced large intestinal tumors
in male Sprague-Dawley rats.
AB - Probiotic bacteria strains were examined for their influence on 1,2
dimethylhydrazine (DMH)-induced intestinal tumors in 100 male Sprague-Dawley
rats. Lactobacillus acidophilus (Delvo Pro LA-1), Lactobacillus rhamnosus (GG),
Bifidobacterium animalis (CSCC1941), and Streptococcus thermophilus (DD145)
strains were examined for their influence when added as freeze-dried bacteria to
an experimental diet based on a high-fat semipurified (AIN-93) rodent diet. Four
bacterial treatments were compared: L. acidophilus, L. acidophilus + B. animalis,
L. rhamnosus, and S. thermophilus, the bacteria being added daily at 1% freeze
dried weight (10(10) colony-forming units/g) to the diet. Trends were observed in
the incidence of rats with large intestinal tumors for three treatments: 25%
lower than control for L. acidophilus, 20% lower for L. acidophilus + B. animalis
and L. rhamnosus treatments, and 10% lower for S. thermophilus. Large intestinal
tumor burden was significantly lower for treated rats with L. acidophilus than
for the control group (10 and 3 tumors/treatment group, respectively, p = 0.05).
Large intestinal tumor mass index was also lower for the L. acidophilus treatment
than for control (1.70 and 0.10, respectively, p < 0.05). Other treatments showed
no statistically significant change from control for these indexes of
tumorigenesis. For rats fed L. acidophilus, no adenocarcinomas were present in
the colons. Pulsed-field gel electrophoresis of bacterial chromosomal DNA
fragments was used to differentiate introduced (exogenous) bacterial strains from
indigenous bacteria of the same genera present in the feces. Survival during gut
passage and displacement of indigenous lactobacilli occurred with introduced L.
acidophilus and L. rhamnosus GG during the probiotic treatment period. However,
introduced strains of B. animalis and S. thermophilus were not able to be
isolated from feces. It is concluded that this strain of L. acidophilus supplied
as freeze-dried bacteria in the diet was protective, as seen by a small but
significant inhibition of tumors within the rat colon.
PMID- 10693170
TI - Effects of garlic oil and its organosulfur compounds on the activities of hepatic
drug-metabolizing and antioxidant enzymes in rats fed high- and low-fat diets.
AB - We examined the effects of garlic oil (GO) and two of its organosulfur compounds,
diallyl sulfide (DAS) and diallyl disulfide (DADS), on the drug-metabolizing and
antioxidant systems in rats and sought to determine whether these effects are
associated with dietary fat. Rats were fed a high-fat diet and received GO or
DADS (200 mg/kg body wt) or DAS (100 mg/kg) orally three times a week for seven
weeks. Control animals received corn oil alone. Another group of rats was fed a
low-fat diet, with or without GO. GO and DADS significantly reduced the body
weight gain of rats (p < 0.05). GO, however, dramatically increased the spleen
weight and spleen weight-to-body weight ratio (p < 0.05). DAS increased
glutathione S-transferase (GST) and 7-pentoxyresorufin O-dealkylase activities,
whereas DADS increased only GST activity (p < 0.05). Immunoblot assay showed GO-,
DAS-, and DADS-enhanced expression of the placental form of GST and cytochrome P
450 IIBI but suppressed cytochrome P-450 IIEI expression. Hepatic antioxidant
enzyme activities were also modulated by these garlic components. GO and DADS
inhibited glutathione peroxidase activity (p < 0.05), and DADS and DAS enhanced
glutathione reductase activity (p < 0.05). Only GO enhanced the superoxide
dismutase activity (p < 0.05). All these garlic components increased glutathione
levels in red blood cells (p < 0.05) but did not influence hepatic glutathione
levels. Although the amount of fat in the diet modulated drug-metabolizing and
antioxidant functions, no interactions between GO and dietary fat were observed.
These results indicate that GO and its allyl sulfide components, as well as
dietary lipid, modulate drug-metabolizing and antioxidant enzyme activities. The
action of GO appears to be independent of dietary lipid content.
PMID- 10693171
TI - Genistein inhibits NF-kappa B activation in prostate cancer cells.
AB - Prostate cancer is the second leading cause of cancer-related deaths in men in
the United States. Epidemiological studies indicate that susceptibility to
prostate cancer may be partly due to environmental influences, especially diet.
An association has been shown between decreased prostate cancer risk and
mortality with increased consumption of soy products, resulting in increased
levels of isoflavones. We previously demonstrated that the soy isoflavone
genistein inhibits cell growth and induces apoptosis in prostate cancer cells. To
further elucidate the molecular mechanism by which genistein elicits its
apoptotic effect, we investigated the role of a transcription factor, nuclear
factor-kappa B (NF-kappa B), in the androgen-sensitive cell line LNCaP and the
androgen-insensitive cell line PC3. Here we show that genistein decreases NF
kappa B DNA binding and abrogates NF-kappa B activation by DNA-damaging agents,
H2O2 and tumor necrosis factor-alpha, in prostate cancer cells regardless of
androgen sensitivity. Additionally, we have demonstrated that genistein reduces
phosphorylation of the inhibitory protein I kappa B alpha and blocks the nuclear
translocation of NF-kappa B, prohibiting DNA binding and preventing NF-kappa B
activation. These results provide a mechanism by which genistein induces
apoptosis in prostate cancer cells: the inactivation of NF-kappa B. Furthermore,
genistein's ability to abrogate NF-kappa B activation by DNA-damaging agents
strongly supports genistein's role as a chemopreventive agent.
PMID- 10693172
TI - Quercetin inhibits benzo[a]pyrene-induced DNA adducts in human Hep G2 cells by
altering cytochrome P-450 1A1 gene expression.
AB - Quercetin is one of the most abundant of the naturally occurring flavonoids. It
has been estimated that about 25-50 mg of quercetin are consumed from the daily
diet. The chemopreventive effect of quercetin on dietary carcinogen has been
intensely studied in animal models; however, knowledge regarding the molecular
mechanism is still limited. In this study, the human hepatoma Hep G2 cell line
was used to investigate how quercetin prevents benzo[a]pyrene (B[a]P)-induced DNA
adducts. The Hep G2 cells were treated with 10 microM B[a]P for 18 hours in the
presence or absence of quercetin. The DNA adduct levels, evaluated by 32P
postlabeling, decreased in a dose-dependent manner after treatment with
quercetin. Cytochrome P-450 1A1 (CYP1A1) and glutathione S-transferase
involvement have been well demonstrated in the modulation of B[a]P-induced DNA
damage. From the assays of both enzyme activities, quercetin inhibits CYP1A1
linked ethoxyresorufin O-dealkylase activity more effectively than glutathione S
transferase activity. To elucidate the molecular mechanisms, reverse
transcriptase-polymerase chain reaction and Western blot were used to evaluate
whether the decrease in CYP1A1 enzyme activity by quercetin is mediated because
of alterations of CYP1A1 transcription or mRNA stability. The results indicated
that quercetin significantly inhibits B[a]P-induced CYP1A1 mRNA and protein
expression. From these findings, we conclude that quercetin suppresses B[a]P
induced DNA damage in human Hep G2 cells by altering CYP1A1 gene expression. Thus
we suggest that dietary quercetin may have a long-term preventive effect on
chemical carcinogenesis, especially in people who eat a diet rich in fruits and
vegetables.
PMID- 10693173
TI - Role of nitric oxide and peroxynitrite in bile salt-induced apoptosis: relevance
to colon carcinogenesis.
AB - Previous work from our laboratory indicated that the bile salt sodium
deoxycholate (NaDOC) induced apoptosis in cultured cells and in normal goblet
cells of the colonic mucosa. We also reported that the normal-appearing flat
mucosa of patients with colon cancer exhibited apoptosis resistance. Using
immunofluorescence in conjunction with confocal microscopy, we now report that
high physiological concentrations (0.5 mM) of NaDOC result in the formation of
nitrotyrosine residues, a footprint for the formation of reactive nitrogen
species, including peroxynitrite, in plasma membrane-associated proteins of HT-29
cells. Because peroxynitrite is formed from the reaction between nitric oxide and
superoxide anion, we specifically looked at the role of nitric oxide and
superoxide anion in NaDOC-induced apoptosis. Pretreatment of cells with the
inhibitor/antioxidants, N-nitro-L-arginine methyl ester, an inhibitor of nitric
oxide synthase, copper (II) 3,5-diisopropyl salicylate hydrate, a superoxide
dismutase mimetic compound, and Trolox, a water-soluble analog of alpha
tocopherol, alone or in combination, sensitized cells to apoptosis induced by 0.5
mM NaDOC. These results suggest that nitric oxide may be part of a signaling
pathway that is responsible for apoptosis resistance. The results also indicate
that nitric oxide does not appear to protect cells against NaDOC-induced
apoptosis by scavenging superoxide anion.
PMID- 10693174
TI - Vitamin E (d-alpha-tocopheryl succinate) decreases mitotic accumulation in gamma
irradiated human tumor, but not in normal, cells.
AB - Previous studies have shown that treatment of tumor cells in vitro with d-alpha
tocopheryl succinate (alpha-TS), a most effective form of vitamin E, alone or in
combination with X-irradiation, reduced the growth of these cells more than that
produced by individual agents. However, it is unknown whether alpha-TS, alone or
in combination with gamma-irradiation, would produce similar effects on normal
cells. To study this, we have compared the effects of alpha-TS on three human
tumor cell lines, HeLa (cervical carcinoma), OVGI (ovarian carcinoma), and A549
(lung carcinoma), with the effects on three human normal fibroblast lines,
GM2149, AG1522, and HF19. Results showed that alpha-TS treatment of HeLa cells
for 20 hours caused inhibition of growth in a dose-dependent manner, but normal
human fibroblasts treated similarly with alpha-TS did not show such an effect.
alpha-TS treatment for 20 hours also decreased mitotic accumulation in all three
tumor cell lines but did not produce such an effect in any of the normal
fibroblasts. As expected, gamma-irradiation with 1 Gy decreased mitotic
accumulation in human tumor cells and normal fibroblasts; however, alpha-TS
treatment for 24 hours before, during, and after irradiation for the entire
experimental period further decreased mitotic accumulation in human tumor cells
but not in normal cells. These data suggest that effects of alpha-TS, alone or in
combination with gamma-irradiation, are selective for tumor cells. Therefore,
existing fear that antioxidants such as vitamin E may protect cancer cells from
free radical damage during radiation therapy is not justified.
PMID- 10693175
TI - Methylcobalamin decreases mRNA levels of androgen-induced growth factor in
androgen-dependent Shionogi carcinoma 115 cells.
AB - Methylcobalamin (MeCbl) is an important enzyme cofactor required for methionine
synthase activity. It also inhibits, in a dose-dependent manner, the
proliferation of an androgen-dependent cell line, SC-3, derived from an androgen
dependent mouse mammary tumor (Shionogi carcinoma 115). In SC-3 cells, androgen
induces the production of androgen-induced growth factor (AIGF), an autocrine
growth factor increasing the proliferation of SC-3 cells. MeCbl treatment
suppressed the androgen-induced, AIGF-mediated growth of SC-3 cells, as well as
the androgen-induced increase of AIGF mRNA. In SC-3 cells, androgen receptors
linked with androgen form complexes that tightly bind DNA and act as
transcription factors in the nucleus to regulate the expression of specific genes
such as AIGF. The number and dissociation constants of androgen receptors in
control and MeCbl-treated SC-3 cells were the same. Similarly, the extent of
binding of normal androgen receptors in nuclei from control and MeCbl-treated
cells was virtually identical. The androgen receptors from control and MeCbl
treated cells showed similar capacities for conversion to a form that tightly
binds to DNA on heat activation. These results suggest that the reduction of AIGF
mRNA, subsequent to the nuclear binding of androgen receptors, may be a partial
cause of the growth-inhibitory activity of MeCbl in SC-3 cells.
PMID- 10693176
TI - Glucocorticoid blockade does not abrogate tumor-induced cachexia.
AB - Cancer-induced cachexia is a common manifestation observed in patients with
malignancies. Elevated levels of circulating glucocorticoids and interleukin-6
(IL-6) have been observed in cancer patients with cachexia and are implicated as
major mediators in this process. The purpose of this study was to investigate the
role of circulating glucocorticoid levels as primary mediators in cancer-induced
cachexia. We evaluated whether inhibition of glucocorticoids with the receptor
antagonist RU-486 could abrogate the detrimental wasting of muscle and adipose
tissues seen in a well-characterized murine tumor-induced cachexia model. Mice
(12/group) were randomized to control, tumor-bearing, control + vehicle, or tumor
bearing + glucocorticoid receptor antagonist groups. Circulating serum
glucocorticoid and IL-6 levels were measured in addition to multiple body
composition parameters, such as total body weight, lean body mass, and adipose
content. The results of this study indicate a significant physiological
alteration in the tumor-bearing host that causes severe and detrimental changes
in body composition parameters. Regression analysis demonstrated a significant
correlation between increased circulating glucocorticoid levels and alterations
in body composition parameters. These observed defects were not abrogated with
the administration of a glucocorticoid receptor antagonist. We therefore conclude
that the untoward effects of tumor-induced cachexia are not mediated primarily by
the peripheral effects of high circulating glucocorticoid levels but may involve
a complex interaction with IL-6.
PMID- 10693177
TI - Plant polyphenols inhibit benzoyl peroxide-induced superoxide anion radical
production and diacylglyceride formation in murine peritoneal macrophages.
AB - Naturally occurring plant polyphenols, which include ellagic acid (EA), tannic
acid (TA), caffeic acid (CA), and ferulic acid (FA), were tested for their
superoxide anion radical (SOR)-scavenging activities. SOR were produced by
interaction of the tumor promoter benzoyl peroxide (BPO) with murine peritoneal
macrophages in vitro. The levels of SOR were assessed microscopically by counting
the number of formazan-positive cells per 250 cells produced by the reduction of
nitro blue tetrazolium. BPO at a concentration of 15 micrograms/1.85 x 10(6)
cells/0.5 ml induced maximum formation of SOR in resident and thioglycollate
elicited cells. All the tested polyphenols were able to inhibit the formation of
SOR induced by the tumor promoter to a variable degree. Inhibition of BPO-induced
SOR formation by polyphenols was in the following order: FA > TA > CA > EA. BPO
stimulated the accumulation of diacylglycerol (DAG) in resident and elicited
macrophages with concurrent release of choline equivalents from macrophages.
Polyphenols inhibited DAG accumulation, which paralleled the inhibition of
choline equivalent release. FA was observed to be the most effective and EA the
least effective inhibitor of SOR formation, DAG accumulation, and release of
choline equivalents. It is likely that inhibition of SOR formation might be due
to some interference in the cellular lipid metabolism and phospholipid equivalent
deacylation and choline release.
PMID- 10693178
TI - High intake of specific carotenoids and flavonoids does not reduce the risk of
bladder cancer.
AB - An analysis of a previously completed Spanish multicentric case-control study of
bladder cancer was carried out using new available data on the contents in foods
of specific carotenoids (alpha-carotene, beta-carotene, lutein, and lycopene) and
flavonoids (quercetin, kaempferol, myricetin, and luteolin) to investigate the
relationship of these phytochemicals with bladder cancer. The study included 497
cases first diagnosed with bladder cancer, 547 neighborhood controls, and 566
hospitals controls, matched by gender, age, area of residence, and hospital.
Usual food intake was estimated using a dietary history questionnaire
administered by trained interviewers. None of the specific carotenoids and none
of the specific flavonoids have been found to be significantly associated with
bladder cancer risk in this analysis. The adjusted odds ratios for subjects in
the highest quartile of intake with respect to subjects in the lowest quartile
were 1.36 (95% confidence interval = 0.94-1.95) for total carotenoid intake and
1.23 (95% confidence interval = 0.85-1.79) for total flavonoid intake. The
results of this study does not support the hypothesis that intake of specific
carotenoids and flavonoids is protective against bladder cancer risk.
PMID- 10693179
TI - Examination of the adolescent patient.
AB - Adolescent patients need knowledge and motivation to practice a healthy
lifestyle. The provider of adolescent health care is uniquely qualified to
provide factual health information and practical advice. Enlisting parental
support for confidential adolescent health services usually is not problematic
when parents and health care providers share common goals and responsibility. The
health care provider must develop rapport to foster high-risk health behavior
disclosure and must promote health messages that are stronger than those received
from peers, television, movies, and magazines. Adolescents who elect to abstain
from sexual activity need as much support as sexually active patients.
Depression, substance abuse, and eating disorders must be recognized and treated.
Preventative health care services for adolescents can be optimized when office
staff understand the special needs of these young women. The physician's concerns
regarding the health of adolescent patients will be welcomed by patients, their
parents, and the community.
PMID- 10693180
TI - Breast disorders in the pediatric and adolescent patient.
AB - Despite the wide range of breast abnormalities that affect patients in the
pediatric and adolescent populations, some conclusions can be drawn. Breast self
examination in the adolescent population is controversial but is recommended for
girls who carry the BRCA1 or BRCA2 gene beginning at age 18 to 21 years. All
girls with a disorder of breast size or symmetry should be given the opportunity
of consultation with a plastic surgeon to discuss reconstructive options.
Ultrasound is the most appropriate initial investigation in any adolescent
patient with a breast mass owing to the dense nature of breast tissue in this age
group. Although it is extremely rare in this population, breast cancer must
always be included in the differential diagnosis of a breast mass, particularly
in the patient with a prior history of childhood malignancy or chest irradiation.
PMID- 10693181
TI - Vulvar disorders in adolescents.
AB - Vulvar disorders are rare in the adolescent. When they occur, they may be
challenging and difficult to diagnose and treat. Biopsies and consultation with a
dermatologist in unclear cases should occur early in the evaluation to allow for
rapid diagnosis and appropriate treatment.
PMID- 10693182
TI - Congenital malformations of the genital tract.
AB - Congenital abnormalities of the genital tract are a source of major morbidity for
teenage girls. Careful counseling is as important as the surgical approach to
management. It is imperative that specialist centers are established worldwide to
deal with these problems. Centralization of services will ensure these girls
receive the highest quality care.
PMID- 10693183
TI - Abnormal uterine bleeding in adolescents.
AB - Irregular bleeding is a common complaint of adolescents and is responsible for
approximately 50% of gynecologic visits in that age group. Most abnormal bleeding
in adolescents is caused by immaturity of the hypothalamic-pituitary-ovarian axis
resulting in anovulation. Approximately 20% of adolescents have an underlying
disorder requiring targeted diagnostic testing. A thorough history and physical
examination and laboratory findings will often reveal the source of abnormal
bleeding. Appropriate treatment is then directed to the underlying cause.
PMID- 10693184
TI - Disorders of excessive hair growth in the adolescent.
AB - Virilization is most often the reflection of a serious underlying condition.
Diagnosis and management should be prompt, thorough, and comprehensive. Hirsutism
is the manifestation of a variety of disorders. It may be associated with serious
acute medical conditions, chronic disorders, or idiopathic. The diagnosis should
be methodical and adjusted to the nature of the clinical presentation. Several
therapeutic modalities are effective and produce satisfactory results for most
patients.
PMID- 10693185
TI - Eating disorders in adolescents and young adults.
AB - Eating disorders are relatively common and frequently result in gynecologic
abnormalities. The gynecologist must appreciate the various manifestations of
these complex health problems as well as the biopsychosocial approach needed to
help the adolescent or young adult woman recover from these chronic conditions.
By recognizing both the medical and gynecologic aspects of eating disorders, the
oversimplified viewpoint of considering these conditions as purely psychiatric
disorders can be avoided. Open and consistent communication with patients, with a
focus on health rather than dysfunction and mental illness, facilitates the
acceptance of a comprehensive approach involving the gynecologist, dietitian, and
mental health provider.
PMID- 10693186
TI - Female adolescent sexuality. Promoting healthy sexual development.
AB - Health care providers must recognize the specific challenges and rewards of
providing services for adolescents. Quality care begins with the establishment of
trust, respect, and confidentiality between the health care provider and the
adolescent. Data suggest that the normal age for beginning puberty is decreasing,
which has important clinical, educational, and social implications. The health
care provider should be aware of the broad range of potential sexual behaviors
involving adolescents, as well as the teen's acceptance of such behaviors, often
dictated by age, gender, culture, and education. When providing gynecologic care
to adolescent girls, the physician should not only provide contraception and
screen for sexually transmitted diseases but should contribute to the development
of the patient's sexual health. Especially when providing care for the younger
teen, the health care provider must focus on involving a member of the family or
another significant adult to provide needed support and guidance. Anticipatory
guidance for parents should focus on assessing their parenting styles and
promoting supervision. Although parents should strive to maintain open
communication with their adolescents, they may not accurately estimate the sexual
activity of and the sexual risk for their teenage children. Parents need to be
encouraged to consider the implications of their own sexual behaviors. The
provider should attempt to foster a comfortable environment in which youth may
seek help and support for appropriate medical care while reserving the right to
disclose their sexual identity when ready. Health care professionals cannot
exclude heterosexual behavior on the basis that a young woman self-identifies as
homosexual. Her reported sexual behaviors may not indicate her sexual
orientation. Self-definition of sexual orientation is a dynamic process including
factors such as fantasies, desires, and behaviors. Self-definition of sexual
identity is affected by individual variations in sex, gender, sexual roles, and
sexual orientation. Most adolescents want to discuss sexual-related issues with
their health care providers and will welcome direct questions about sexual
behaviors and possible risks when posed in a confidential and nonmoralistic
manner. Discussion of the physical, emotional, familial, and social changes
related to adolescence will encourage healthy sexual development.
PMID- 10693187
TI - Update on adolescent contraception.
AB - Recent advances in OCPs include less androgenic progestins and lower doses of
ethinyl estradiol. All low-dose OCPs are safe in terms of venous thrombosis risk
in appropriately chosen patients. DMPA is a safe and effective long-acting
contraceptive agent; clinical attention should be directed to its most common
side effect, irregular bleeding. DMPA does not seem to affect mood, and it is
uncertain what impact it has on weight changes. More research needs to be
conducted on its impact on adolescent bone metabolism. Norplant continues to be
the only subdermal contraceptive implant marketed in the United States. It
provides safe and effective contraception and has the best continuation rate of
all types of hormonal contraception. Its most common side effect is irregular
bleeding. Norplant may be especially well suited for adolescents who have
recently been pregnant or who are not tolerating other types of contraception.
Emergency postcoital contraception continues to be underused in the United
States, with a lack of awareness among patients and clinicians. Mechanisms of
action include a delay in ovulation and interference with implantation. Research
and public health groups are striving to increase patient and provider awareness
and use of emergency contraception.
PMID- 10693188
TI - Adolescents and sexually transmissible diseases.
AB - Sexually transmitted infections are alarmingly common among adolescents in the
United States. Behavioral, biologic, and health care access factors place
adolescent girls at high risk for many common infections. This population also
experiences a disproportionate burden related to the sequelae of STDs. The costs
are high for the individual adolescent and for society. Clinicians treating
adolescent girls should address the general lack of knowledge about the risks and
consequences of STDs. They should be prepared to offer confidential and
comprehensive counseling, screening, and treatment according to established
guidelines. Office policies that protect adolescent confidentiality are an
important component in providing effective care. Adolescence is a period during
which lifelong health behaviors are established. It provides a critical
opportunity for promoting responsible behaviors and reducing risks through health
promotion and prevention strategies.
PMID- 10693189
TI - Pelvic pain. A SAFE approach.
AB - The efficacy of a multidisciplinary approach for the treatment of chronic pain
has been well documented. A recent randomized prospective trial by Peters and co
workers confirmed that multidisciplinary management of chronic pelvic pain
resulted in greater improvement in pain severity, increased employment, and
improved functional health scores when compared with a traditional medical
approach. Unfortunately, many gynecologists do not have the luxury of working in
these types of settings. The SAFE approach allows the busy practitioner to
evaluate the nonorganic and organic nature of pelvic pain simultaneously to
manage these difficult patients better. Initially, it is important to set up
regular weekly visits with a prespecified time limit. During these sessions, one
should focus on compliance to treatment recommendations. Components of management
that have led to pain reduction should be defined. Over time, these short visits
can be spaced to bimonthly and monthly intervals; however, this strategy should
not be rushed. If possible, the gynecologist should coordinate the care of
difficult patients with a physical therapist and mental health provider who can
work in tandem on pain reduction strategies and focused psychotherapy. The
gynecologist should focus the patient's attention on improvements in pain reports
and in functioning at school or work and reinforce the consistent use of
medications, even if the recommended dose is low. Small improvements in health
beget larger improvements in daily functioning.
PMID- 10693190
TI - Reproductive health services for adolescents. Critical legal issues.
AB - The contemporary legal and policy environment has increased the challenges
associated with providing health care services to the adolescent population. The
issue of reproductive health care services is particularly intense because of the
controversial nature of services for contraception and abortion. As the debates
continue, one must remember the background against which they are occurring. The
current legal framework, developed over nearly 40 years, enables adolescents who
are minors to give their own consent for care in numerous circumstances and
provides them with a significant level of confidentiality protection,
particularly for reproductive health services. Laws have been enacted to expand
adolescents' financial access to health care, through targeted publicly funded
service programs and expanded health insurance coverage. This background provides
the foundation for addressing the current challenges and for protecting and
expanding adolescents' access to care.
PMID- 10693191
TI - 'A real call to action'.
PMID- 10693192
TI - Questioning APR cartridge use.
PMID- 10693193
TI - Questioning APR cartridge use.
PMID- 10693194
TI - Ten ways to deal with turf wars.
PMID- 10693196
TI - Ergonomics E-sources.
PMID- 10693195
TI - ASHRAE 62-1999 ventilation for acceptable indoor air quality, addendum n.
PMID- 10693197
TI - Fresh ideas for keeping crews safe.
PMID- 10693198
TI - Where workers need more than a brake.
PMID- 10693200
TI - Before the fire.
PMID- 10693199
TI - Small spaces, big hearts.
PMID- 10693201
TI - Unseen dangers.
PMID- 10693202
TI - Looming liability.
PMID- 10693203
TI - The S.P.I.C.E. model for return to work.
PMID- 10693204
TI - The aggression continuum: a paradigm shift.
PMID- 10693205
TI - Don't forget the "D" in the "ABCs" of emergency care.
PMID- 10693206
TI - Emergency cases with a twist.
PMID- 10693207
TI - A teenager acting strangely.
PMID- 10693208
TI - Bronchiolitis--or is it?
PMID- 10693209
TI - Hocus-pocus: a case of abdominal pain after blunt abdominal trauma.
PMID- 10693210
TI - An offbeat wheezer.
PMID- 10693211
TI - A lethargic infant: ingestion or deception?
PMID- 10693212
TI - A 12-year-old boy with protean pain.
PMID- 10693213
TI - The case of the red eye.
PMID- 10693214
TI - The case of the missing "olive".
PMID- 10693215
TI - Getting to the heart of the matter.
PMID- 10693217
TI - Ageing and safety promotion--what do we know and where are we going?
PMID- 10693216
TI - Health promotion for older people: what are the opportunities?
PMID- 10693218
TI - Dementia care: challenges for an ageing Europe.
PMID- 10693219
TI - Planning a breast cancer health promotion. Qualitative and quantitative data on
Puerto Rican elderly women.
PMID- 10693220
TI - The WHO perspective on active ageing.
PMID- 10693221
TI - Brief to the World Trade Organization: world trade and population health.
PMID- 10693222
TI - [Gerontology in the health promotion world].
PMID- 10693223
TI - Commentary: beyond preclassified reality.
PMID- 10693224
TI - Fabricated trauma exposure: an analysis of cognitive, behavioral, and emotional
factors.
AB - The 1995 Oklahoma City bombing was a disaster of unparalleled dimension in the
United States. The professional response included the development of systematic
clinical and research programs. This article describes the case of a child who,
as a participant in a research study, appeared to fabricate a story of bomb
related loss. The research and clinical records of this child were examined and
analyzed according to the factors and conditions that might underlie this
fabrication. These include issues related to memory and suggestibility, symptom
contagion, and mass hysteria. The report describes the role of psychological
vulnerability in trauma and this child's coping and adaptation.
PMID- 10693225
TI - Avoidance in trauma: conscious and unconscious defense, pathology, and health.
AB - Drawing from our work with children seen following the 1995 bombing of the Alfred
P. Murrah Federal Building in Oklahoma City, Oklahoma, this article describes
clinical aspects of avoidance in traumatized children and their families.
Avoidance in traumatized children and their families seems a final common pathway
arising from a number of diverse factors. The importance of particular factors
for assessment and treatment is emphasized.
PMID- 10693226
TI - Posttraumatic obsessive-compulsive disorder: a three-factor model.
AB - This paper presents a three-factor causal model of obsessive-compulsive disorder
(OCD), which posits that exposure to long-term traumatic stress generates an
inordinate degree of anxiety during the psychological development of the
premorbid OCD child. In response to these conditions the child evolves a distinct
cognitive style characterized by exaggerated threat appraisal and magical
beliefs, and experiences alterations in brain metabolism. An entire functional
brain system (a basal ganglia-orbitofrontal circuit) enters into a state of
enhanced responsiveness following exposure to protracted threat. Over time the
threshold for stimulation is dramatically lowered, resulting in a
hypersensitivity to cues that signify potential harm. Individuals adapt to this
hypersensitivity through a variety of strategies, which constitute OCD.
PMID- 10693227
TI - Posttraumatic stress disorder: cerebellar regulation of psychological,
interpersonal, and biological responses to trauma?
AB - Alteration in the sense of time is the most commonly reported peritraumatic
dissociative symptom. A case report of a trauma victim illustrates the
posttraumatic alteration in the sense of time as well as loss of spatial memory.
Recent studies of cerebellar function indicate the cerebellum may be critical to
both spatial memory and the sense of time. Identifying regulators of
psychological, interpersonal, and biological responses to traumatic events is
important in advancing our understanding of the effects of trauma. The cerebellum
may be part of the initial posttraumatic response.
PMID- 10693228
TI - Commentary: deconstructing self-destruction.
PMID- 10693229
TI - "You are not your body": commentary on "The motivations for self-injury in
psychiatric inpatients".
PMID- 10693230
TI - The motivations for self-injury in psychiatric inpatients.
AB - Nonsuicidal self-injurious behavior (SIB) occurs in both culturally appropriate
and culturally inappropriate forms. It is one of the diagnostic criteria for
borderline personality disorder, but it occurs in several psychiatric and
neurological populations. The personal intent of SIB in psychiatric populations
is incompletely understood. A self-report scale (Self-Injury Motivation Scale;
SIMS) to assess motivation for self-injury was developed. Relationships among
motivation for SIB, characteristics of SIB, and psychopathology were explored. A
semistructured interview and the SIMS, Dissociative Experiences Scale, Beck
Depression Inventory, Davidson Trauma Scale, and Millon Clinical Multiaxial
Inventory-II were given to 99 consecutively admitted inpatients. The SIMS had
good reliability and validity. A high SIMS score suggested distinct
psychopathology. Several factors on the SIMS differentiated motivations for SIB.
Patients with different SIMS factor profiles had different psychopathology.
PMID- 10693231
TI - Family boundary ambiguity predicts Alzheimer's outcomes.
AB - This study examines caregiver and patient relationship characteristics in the
etiology of behavior problems in Alzheimer's disease. Seventy-two caregivers and
patients were assessed twice, 12 months apart. Cross lag panel analysis was used
to test for one-way or reciprocal causal links among caregiver variables, patient
impairment measures, and patient behavior problems. Caregiver distancing from
patients (closeout) predicted increases in the frequency of behavior problems,
including activity disturbances, paranoia, and anxiety. These behaviors in turn
led to increased closeout of the patient by the caregiver. The reciprocal causal
associations found in this study suggest that dysfunctional family interactions
may underlie patient behavior problems and caregiver distress.
PMID- 10693232
TI - Adjunctive cognitive-behavioral therapy for rapid-cycling bipolar disorder: an
empirical case study.
AB - A basic biopsychosocial model of episode onset in rapid-cycling bipolar disorder
is presented with a special emphasis on cognitive and other psychosocial
contributors. A three-pronged, face-valid, cognitive-behavioral treatment
protocol meant to supplement medications is deduced from the available research
literature. The concrete treatment components focus on prevention of mood cycles,
early detection of cycle onset, and mood restabilization during cycles. The
treatment protocol was pilot tested on a rapid-cycling bipolar patient who first
received pharmacotherapy only followed by pharmacotherapy plus adjunctive
cognitive-behavioral therapy (CBT). Detailed treatment measures were collected
before, during, and after treatment. A comparison of Beck Depression Inventory
and Young Mania Scale scores in pharmacotherapy versus pharmacotherapy plus CBT
conditions suggest the addition of CBT produces significant clinical gains.
Scores on the Beck Anxiety Inventory and Hopelessness Scale provide further
support for the CBT treatment model. These preliminary results suggest cognitive
behavioral or similarly structured psychosocial treatment models could greatly
enhance the medical treatment of rapid-cycling bipolar patients and warrants
further controlled investigation.
PMID- 10693233
TI - Exploring the relationship between the person and the disorder among individuals
hospitalized for psychosis.
AB - Recent research has suggested that people suffering from severe mental illness
develop strategies to cope with their disorder. This study describes one specific
strategy of coping with psychosis--through the use of narrative or a story. The
report is based on bimonthly, semistructured research interviews conducted with
43 persons who were hospitalized for severe mental illness with psychotic
features over a 1-year period. Qualitative analysis revealed five distinct
categories, which seem to reflect different interactions between the
participants' sense of self in relation to their illness. Narrative theory helped
to identify subtleties in these interactions described by participants and
conceptualize the categories. Conceptual and clinical implications of this
process and future research opportunities are discussed.
PMID- 10693234
TI - Epidemiology of esophageal cancer, especially adenocarcinoma of the esophagus and
esophagogastric junction.
AB - The incidence of adenocarcinoma of the esophagus and esophagogastric junction
(EGJ) has been increasing over the past 15 years in western countries. Surgical
series and population-based studies show that, by 1994, adenocarcinomas of the
esophagus accounted for half of all esophageal cancer among white men. The causes
of this increase in incidence remain to be elucidated. Esophageal adenocarcinomas
and a portion of EGJ adenocarcinomas arise from long and short segments of
specialized intestinal metaplasia (Barrett's esophagus). The prevalence of long
segments of Barrett's esophagus (> 3 cm) in patients having endoscopy for reflux
symptoms is 3%, and 1% in those undergoing endoscopy for any clinical indication.
However, a silent majority of patients with Barrett's esophagus remain
unrecognized in the general population and may not be diagnosed unless
adenocarcinoma develops. Recent studies document a rise in the diagnosis of
specialized intestinal metaplasia of the cardia. Nearly all these patients have
associated carditis, and Helicobacter pylori infection has been linked to this
condition. The possible origin of EGJ adenocarcinomas in the sequence carditis-
specialized intestinal metaplasia needs to be clarified. Smoking and obesity are
additional risk factors for adenocarcinoma of the esophagus and EGJ. Current data
does not confirm H. pylori as a risk factor for cancer of the EGJ.
PMID- 10693235
TI - Modern pathology: prognostic parameters in squamous cell carcinoma of the
esophagus.
AB - In the present study the prognostic impact of new histological and molecular
parameters were tested retrospectively in a series of 149 patients with
esophageal squamous cell carcinoma (SCC) who underwent potentially curative
resection therapy. In addition, the prognostic value of various molecular markers
was investigated in a group of 38 patients with locally advanced esophageal SCC
treated using combined therapy modalities. In the surgically treated carcinomas,
the following morphological parameters proved to be prognostically significant in
univariate survival analysis and multivariate survival analysis: pattern of
invasion, inflammatory response, and lymph vessel invasion. In contrast, tumor
grading according to the criteria of the WHO and tumor cell proliferation did not
show significant prognostic impact. Concerning the prognostic influence of
molecular parameters, strong expression of the proliferation regulating molecule
p21WAF1 and weak expression of the apoptosis regulating molecule Bcl-XL were
predictors of poor survival in univariate and multivariate survival analysis. No
prognostic impact was shown in relation to the expression of p53 and the
apoptosis regulating molecules Bcl-2 and Bax. In the multimodally treated
esophageal cancer patients, strong expression of p21WAF1 and accumulation of p53
were predictors of poor survival, whereas expression of Bcl-2, Bax, and Bcl-XL
had no prognostic significance. In conclusion, morphological and molecular
parameters may provide important prognostic information for esophageal cancer
patients.
PMID- 10693236
TI - Malignant progression in Barrett's esophagus: pathology and molecular biology.
AB - Due to its increasing incidence, esophageal adenocarcinoma and its precursor
lesions have received increasing attention in recent years. The histopathologic
steps in the process of malignant progression in Barrett's esophagus are well
described and include the following: (a) metaplasia of the normal esophageal
squamous epithelium to a specialized intestinal glandular epithelium, (b)
development of dysplasia (classified histologically as low and high grade), and
(c) development of adenocarcinoma characterized by invasive and metastatic
potential. Intestinal metaplasia can be identified by the presence of goblet
cells, the detection of which can be aided by finding mucin stained by Alcian
blue at low pH. Despite this well-characterized sequence, the timing of the
development of dysplasia and the subsequent transition to carcinoma and the risk
of development of carcinoma in low- and high-grade dysplasia are not precisely
known. In addition, there are problems in the identification of dysplasia,
including sampling error and interobserver discrepancies among pathologists. A
better understanding of the mechanisms of these events would allow early
identification and elimination of high-risk lesions before adenocarcinoma with
its attendant poor prognosis were able to develop. In order to better understand
this process and to potentially identify early markers of malignant
transformation, a variety of molecular studies have been carried out in recent
years on adenocarcinoma and its precursor lesions in Barrett's esophagus. On the
phenotypic level, increased expression and changes in pattern of expression of
proliferation marker (Mib-1) Ki-67 antigen, overexpression of p53 protein,
overexpression of growth factors such as epidermal growth factor (EGF), c-erbB2,
and transforming growth factor (TGF)-a, decreased and abnormal expression of the
cell adhesion molecule E-cadherin, and, in carcinomas, increased expression of
serine proteases have all been described. A new area of interest is the family of
rab proteins, which play an important role in maintaining cell polarity in the
gastrointestinal tract. Increased expression of one of these proteins, rab11, has
been described in low-grade, but not high-grade dysplasia. In cytogenetic
studies, an increased S-phase fraction, followed by an increased tetraploid (4N)
fraction and then aneuploidy, has been described. So far, the specific genes
which have been most thoroughly investigated have been p53, APC, p16, and the
sites of probable tumor suppressor genes, including 3p (FHIT), 13q, and 18q. With
only a few exceptions (i.e., rab11 expression, and possibly mutations of FHIT),
the numerous molecular abnormalities which have been described occur late in
malignant progression, which means that the best marker which presently exists to
identify high-risk lesions in Barrett's esophagus is the histologic
identification of dysplasia in endoscopic biopsies, especially high-grade
dysplasia. We are presently beginning studies using laser microdissection and
competitive genomic hybridization (CGH), which could help to identify new
chromosomal areas that might contain genes that are crucial in the early phases
of malignant progression in Barrett's esophagus. In the future, identification of
such early molecular events which predispose to carcinoma development will allow
more precise and earlier risk assessment for individual patients, therefore,
enabling more effective therapy.
PMID- 10693237
TI - Malignant degeneration of Barrett's esophagus: clinical point of view.
AB - The incidence of adenocarcinoma of the distal esophagus is increasing at an
alarming rate. Intestinal metaplasia in the distal esophagus, i.e. Barrett's
esophagus, has been identified as the single most important risk factor for these
tumors. Barrett's esophagus develops as a consequence of chronic mucosal injury
in up to 10% of patients with long-lasting gastroesophageal reflux disease.
Experimental and clinical data indicate that adenocarcinoma of the distal
esophagus is a direct consequence of mixed (i.e., acid and bile) reflux into the
esophagus. Interestingly, Helicobacter pylori infection of the stomach appears to
exert a protective effect against the development of esophageal adenocarcinoma.
Neither aggressive medical acid suppression nor antireflux surgery can induce a
predictable regression of Barrett's esophagus or exert a protective effect
against its malignant degeneration. Endoscopic ablation of Barrett's esophagus,
although appealing, currently constitutes a potentially dangerous procedure
without proven benefit for the patient. Since the development of Barrett's
adenocarcinoma follows a multistep process from metaplasia through increasingly
severe grades of dysplasia, close endoscopic surveillance with extensive biopsies
currently remains the only means to identify patients at risk for malignant
degeneration and detect esophageal adenocarcinoma at an early and curable stage.
PMID- 10693238
TI - New diagnostic methods for esophageal carcinoma.
AB - The increasingly severe problem of esophageal carcinoma on world public health
merits the application of new endoscopic methods to assist in early detection and
screening. Older methods, such as tissue staining, combined with magnification
endoscopy, have shown promising results, while newer techniques capitalize on
measurements that discriminate benign from malignant cells based on a wide array
of different attributes, ranging from the molecular to the macroscopic level.
Instrumentation based on laser-induced fluorescence spectroscopy, ratio
fluorescence imaging, elastic scattering spectroscopy, Raman spectroscopy, and
optical coherence tomography is presently being tested and compared with standard
endoscopic techniques. Using pathologic interpretation of pinch biopsies as the
"gold standard," these techniques have shown the ability to identify dysplastic
or malignant regions of tissue that would not be visible to the unassisted
endoscopist and offer increased sensitivity for detection compared to rigorous
random biopsy protocols. The rapid speed of the instruments allows the provision
of information to the endoscopist almost instantaneously, potentially allowing
therapeutic decisions to be conducted within the confines of the same endoscopic
procedure, thereby achieving gains in efficiency and reductions in overall cost.
Large, multicenter trials will be necessary to determine the sensitivity and
specificity of individual and combined techniques, as well as their ability to
favorably influence the early detection, management, and overall outcome of this
disease.
PMID- 10693239
TI - Esophageal carcinoma: current staging strategies.
AB - A patient with suspected esophageal carcinoma represents a challenge to the
treating physicians. Most patients present with an advanced stage of disease, and
in the majority of cases only palliative treatment can be offered. Various
treatment modalities are available, which are applied according to the TNM stage
of the disease and the performance status of the patient. A precise histological
diagnosis and highly accurate tumor staging of a patient with esophageal
carcinoma is a prerequisite for the selection of the most suitable treatment
option. Endoscopic ultrasound (EUS) has emerged as the most accurate diagnostic
modality for locoregional staging. Problems in identifying early tumor stages or
tumor strictures can be generally overcome by using miniprobe sonography (MPS).
EUS/fine-needle aspiration biopsy (FNA) technology provides a valuable means of
identifying suspicious locoregional lymph nodes. Patients with a proximal tumor
(trachea bifurcation) should undergo bronchoscopy to rule out infiltration of the
tracheobronchial system. Ultrasound (US), computed tomography (CT), and possibly
magnetic resonance imaging (MRI) are the diagnostic tools of choice for extended
tumor staging. After excluding extended tumor stage and severe concomitant
diseases, diagnostic laparoscopy with intra-abdominal ultrasound should be
performed in patients with adenocarcinoma of the esophagus prior to
esophagectomy. Intra-abdominal metastases which can be missed preoperatively in
some cases have to be ruled out in order to avoid unnecessary surgery.
PMID- 10693240
TI - What's new in imaging? New magnetic resonance imaging of esophageal cancer using
an endoluminal surface coil and antibody-coated magnetite particles.
AB - An endoluminal surface coil: Esophageal cancer was studied by high resolution
magnetic resonance imaging (MRI) to determine the histopathologic basis for
signal intensity in these lesions and to determine the potential of this modality
for evaluating the depth of cancer invasion. In a basic study, 14 tumors were
examined with a 1.5-T superconductive MR system using a surface coil. The
esophageal wall could be differentiated into four layers on the T1-weighted
images and seven layers on the T2-weighted images. The signal intensity of the
tumor varied from low to intermediate on the T1- and T2-weighted images. The
submucosal layer is important in evaluating cancer invasion on the T2-weighted
images. In a clinical study, 30 patients with esophageal cancer were examined
with a 1.5-T superconductive MR system using an endoluminal surface coil. In
terms of depth of cancer invasion, the accuracy rate of MRI using the endoluminal
surface coil was 83%. In conclusion, MRI with an endoluminal surface coil will be
a useful examination for esophageal cancer in the future. Antibody-coated
magnetite particles: A highly specific and effective MRI contrast agent was
prepared by coating superparamagnetite particles with monoclonal antibodies
(MAbs) directed against epidermal growth factor receptors (EGFRs), which are
overexpressed in esophageal squamous cell carcinoma. The agent was shown to have
EGFR-specific MRI contrast capacity in vivo in athymic rats bearing TE8 or H69
tumors. Immunospecific MRI using magnetite particles coated with MAbs against
EGFR seems to be useful in the diagnosis of squamous cell carcinoma of the
esophagus.
PMID- 10693241
TI - Risk analysis in esophageal surgery.
AB - The postoperative mortality after esophagectomy still remains a major factor
influencing the prognosis of esophageal cancer and largely depends on the
patient's preoperative physiological status. A composite scoring system was
developed to predict the risk of esophagectomy, based on quantitative assessment
of preoperatively available physiological parameters. The scoring system was
reviewed retrospectively on operated patients and evaluated prospectively in two
subsequent patient groups. An initial retrospective multivariate analysis of 432
esophagectomy patients identified a compromised general status (p = 0.001) and
poor cardiac (p < 0.001), hepatic (p < 0.05), and respiratory (p < 0.05)
functions as independent predictors of a fatal postoperative course. Based on the
relative risks associated with individual impaired organ functions--general
status 3.6, cardiac function 2.8, hepatic function 2.1, pulmonary function 1.7--a
composite risk score was established. A prospective study in 121 patients
confirmed that this composite scoring system provides better identification of
high-risk patients than does any of the individual parameters alone. Including
this composite score into the process of patient selection and choice of
procedure resulted in a decrease of postoperative mortality from 9.4% (52/553) to
1.2% (4/323) (p = 0.001). The risk of death after esophagectomy for esophageal
cancer can be objectively assessed prior to surgery and quantified by a composite
risk score. This score provides a useful tool in refining the criteria of patient
selection for resection and choice of procedure, and markedly reduces
postoperative mortality when applied prospectively.
PMID- 10693242
TI - Neoadjuvant chemoradiation followed by surgery for resectable esophageal cancer.
AB - Neoadjuvant chemoradiation (NAC) therapy protocols were developed to improve
survival in patients with resectable esophageal cancer. Our experience with two
consecutive NAC therapy trials is reviewed. Both studies included patients with
localized squamous cell cancer and adenocarcinoma. Patients were treated with
cisplatinum 26 mg/m2/day (days 1-5 and 26-30), 5-Fluorouracil (5-FU) 300
mg/m2/day (days 1-30), concurrent radiotherapy (4400 cGy) followed by
esophagectomy. In the second trial, adjuvant taxol was added. The first protocol
had 50 patients. Two patients died, both before surgery, one from sepsis. There
was no residual viable tumor (CR) in 19 (40%) patients. The median survival time
was 31 months. The 5-year survival rate of 36% compared favorably with concurrent
5-year survival of 18% for surgery alone. Forty-one patients were enrolled in the
second trial. All underwent surgery. There were no treatment or operative deaths.
Survival data for this group is maturing. Combined results from both protocols
are: treatment mortality of 2.2%, complete response rate of 37%, and a median and
3-year disease-specific survival of 42 months and 54%, respectively. We conclude
that NAC followed by surgery improves survival over surgery alone and that CR is
predictive of improved survival.
PMID- 10693243
TI - Neoadjuvant therapy of squamous cell carcinoma of the esophagus.
AB - Because of the high risk of recurrence following surgery for squamous cell
carcinomas of the esophagus, treatment involving both systemic therapy and a
localized approach [either surgery alone or chemo/radiation and surgery] have
been extensively studied. Pilot trials have demonstrated safety for the use of
chemotherapy followed by operation, or for chemotherapy plus standard radiation
plus surgery. Larger scale phase III trials, in which either of these two
strategies is employed, have now been reported. For chemotherapy followed by
surgery, conflicting results have recently been noted. A US intergroup trial
showed no significant outcome for all patients treated. A smaller European study,
also using a cisplatin-based regimen, had a positive result. Similarly, for
chemoradiation followed by operation, two recent random assignment studies failed
to demonstrate a significant difference in outcome. However, recently newer
chemotherapy agents have been identified which hold promise for more effective
therapy. These include paclitaxel and irinotecan. Phase II trials, using these
agents prior to surgery, are underway or have been completed, and phase III
studies are in the advanced planning stage. Until these trials have demonstrated
superiority, surgery alone or chemoradiation without surgery remain the standard
of care, for patients with esophageal cancer.
PMID- 10693244
TI - Therapy of cervical esophageal carcinoma.
AB - Surgical treatment of cervical esophageal cancer is influenced by special
problems arising from the anatomical characteristics of this organ. The cervical
and thoracic extension of these tumors makes an extensive lymphadenectomy
necessary, and radical resections often may only be achieved by laryngectomy. The
extent of the resections performed determines the type of intestinal restoration
by gastric or colonic interposition and small bowel transplantation. The
patient's voice may be preserved by means of tracheopharyngeal shunts with
intestinal interposition. The advances of radiation therapy and chemotherapy will
enable less extended resections with greater rates of laryngeal preservation.
PMID- 10693245
TI - Esophageal cancer: a European perspective.
AB - A survey was conducted among a group of European surgeons in order to investigate
current attitudes and strategies in the management of squamous cell carcinoma of
the esophagus. The survey consisted of a questionnaire mailed to surgeons in
eight different countries with extensive clinical experience and scientific
interest in the field. Eight questionnaires including the data of 6146 operated
patients were available for analysis. A consensus emerged among the panelists
that protocols of induction therapy should be routinely used in patients with
locally advanced disease, especially in supracarinal tumors. Four of the surgeons
advocated bilateral neck dissection in these patients. A progressive improvement
in survival over the past three decades was noted. After 1990, the postoperative
mortality rate was 6.2% after surgery alone and 9.7% after chemoradiation therapy
followed by surgery. The 5-year survival rate after a complete resection was
38.5%. In the opinion of the panelists, esophagectomy remains the "gold standard"
of therapy and should be regarded as an integral component of the treatment plan
for patients with squamous cell carcinoma.
PMID- 10693246
TI - Significance of extended systemic lymph node dissection for thoracic esophageal
carcinoma in Japan.
AB - In 1986, several institutions in Japan began to employ extensive lymphadenectomy
for thoracic esophageal cancer. The aim of this article is to point out several
confusing factors concerning the use of the terms "tow-field" and "three-field"
lymph node dissection for thoracic esophageal cancer. In two-field nodal
dissection, two components are included with (modern two-field) or without
(traditional two-field) nodal dissection around both recurrent laryngeal nerve
chains in the upper mediastinum. We studied a series of 353 patients resected for
thoracic esophageal cancer in our institution. The patients were divided into
three groups. Group A was the traditional two-field group of patients who
underwent thoracoabdominal lymphadenectomy without upper mediastinal lymph node
dissection after preoperative irradiation; group B was the modern two-field
group, with additional upper mediastinal lymph node dissection; and group C was
the three-field group with additional neck lymph node dissection. Groups B and C
were operated on during the same period and did not received preoperative
irradiation. The 5-year survival rate in group B was 54.9%, which was better than
the 47.6% rate after three-field dissection (group C). The key to extensive
lymphadenectomy for thoracic esophageal cancer does not lie in "cervical
dissection" but in the meticulous dissection of the lymph nodes around the right
and left recurrent laryngeal nerves.
PMID- 10693247
TI - Gastric conditioning.
AB - The etiology of esophagogastric anastomotic leaks is often multifactorial.
However, occult ischemia of the gastric fundus is an important cause. In gastric
conditioning, preliminary partial gastric devascularization is carried out 2-3
weeks before construction of the esophagogastric anastomoses. Gastric vascularity
improves over this time. In animal studies, gastric conditioning has reduced the
incidence of anastomotic leaks. Clinically, the concept of gastric conditioning
can be used in several ways. Esophagectomy can be done at one stage, then a
cervical esophagogastric anastomosis can be completed as a second-stage
procedure. Pre-esophagectomy angiographic gastric artery embolization is another
method of gastric conditioning. Finally, laparoscopic partial gastric
devascularization can be done at the time of laparoscopic cancer staging. For
gastric conditioning to be clinically useful, the benefit from reduction in leaks
must be greater than the costs and morbidity of the conditioning procedure
itself.
PMID- 10693248
TI - Fundus rotation gastroplasty: a modified gastric tube.
AB - Anastomotic failure remains to be one of the main problems in esophageal surgery
with leakage rates up to 30% being reported currently. We addressed that problem
by modifying the gastric-tube formation in utilizing all of the gastric fundus
and omitting the resection of the lesser gastric curvature and accompanying
vessels. Experimentally, those fundus-rotation gastroplasties were significantly
longer and better perfused than conventional gastroplasties. In a clinical series
of 53 patients (45 male, eight female, range 42-83 years) undergoing esophageal
resection (49 malignancies, four non-malignant esophageal disease), four
anastomotic leakages were found (7.5%). Three patients died due to a bronchial
leak and adult respiratory distress syndrome, one with a complete gastric-tube
necrosis and one with a colon perforation, sepsis and multiorgan failure. Eight
patients developed a significant anastomotic stricture requiring repeated
endoscopic dilatations. From our experimental and clinical experience, we
conclude that the favorable length and perfusion of fundus-rotation
gastroplasties allow for safe anastomosis at either the cervical or thoracic
level.
PMID- 10693250
TI - Complications following esophageal surgery.
AB - Chronologically, complications can be classified as intraoperative, early, and
late. The authors analyze complications according to this classification on the
basis of more than 400 esophageal operations and related literary data. As
regards intraoperative complications, they deal only with those occurring at
transhiatal esophagectomy (e.g., tracheal tear, bleeding, pneumothorax, laryngeal
nerve injury). Among the early complications, they survey the incidence of
transplant necrosis and related mortality, further sequelae ensuing from subacute
ischemia of the replaced organ and analyze in detail the questions which arise
regarding anastomotic leakage. Firstly, they deal with those causative factors
that influence the frequency of anastomotic insufficiency, such as the technical
"know-how" of anastomosis making (e.g., one layer vs two layers; stapling or
manual suture; interrupted or running suture), the way of replacement using whole
stomach or tube-stomach and the consequences originating from the route of
replacement (e.g., anterior or posterior mediastinal route). Incidence and
management of chylothorax are also dealt with. While dealing with late
complications, the authors give a detailed comment on anastomotic strictures and
also other factors facilitating the development of late dysphagia, such as peptic
stricture and tumor of the organ remnant. Finally, some cases successfully
treated by surgery are presented (skin-tube formation in cases following
transplant necrosis; abolition of a pharyngogastric anastomosis stricture using a
free jejunal transplant and surgical solution of an anastomotic stricture from
median sternotomy approach).
PMID- 10693249
TI - Colon interposition.
AB - In the anatomy of the colon vasculature, the ascending branch of the left colic
artery is the primary supplying vessel (96.91%). Isoperistaltic transposition of
the transverse colon is preferred (83.58%). Riolan's vascular arcade is not a
major vessel of the colon. It can only be found in less than 10% of patients, and
whether or not this arcade is complete cannot be used as criterion to judge colon
blood supply. Animal experiments and clinical studies have confirmed the
superiority of one-layer over two-layer anastomosis. The former is simpler,
safer, and more reliable, with a lower incidence of anastomotic leak or
stricture. Based on a comprehensive evaluation of the disease type, patient age,
heart and lung functions, nutritional status, and accompanying diseases, three
colon transposition routes are available (anterosternal subcutaneous tunnel,
retrosternal tunnel, and esophageal bed passage). The advantages and
disadvantages of each route are analyzed, and the left-middle-left retrosternal
route is described. The indications for esophageal reconstruction with colon
operation (ERC) were collected and verified, increasing the number of indications
to seven categories of diseases. The main complications of ERC, i.e., colon
segment necrosis, anastomotic leak, recurrent laryngeal nerve injury, and
intestinal obstruction were systematically studied, and their causes and
prevention are detailed. The number of patients is the highest in a single unit
among all the published reports. The incidence of complications and deaths are
the lowest.
PMID- 10693251
TI - Photodynamic therapy.
AB - Photodynamic therapy (PDT) is a treatment modality that utilizes a
photosensitizing drug activated by laser-generated light and is proving effective
for oncologic and nononcologic applications in the gastrointestinal tract. This
article provides an overview of the most frequently used photosensitizers and
clinical PDT studies in the upper gastrointestinal tract. In the future, the best
indications for PDT in the esophagus will not comprise the palliative treatment
of obstructing tumors but precancerous lesions such as Barrett's esophagus with
or without dysplasia and early cancer. PDT might establish itself as a minimally
invasive treatment alternative compared with surgery for high-grade dysplasia or
early mucosal cancer of the esophagus.
PMID- 10693252
TI - Endoscopic mucosectomy: an alternative treatment for superficial esophageal
cancer.
AB - Recent trends in the management of superficial esophageal cancer consist of
improved detection, pretherapeutic staging and reliable criteria for curative
endoscopic therapy. The endoscopic treatment is legitimate when the cancer is at
an early stage, intra-epithelial or microinvasive (m1 or m2) and N0. Submucosal
cancer should not be treated with a curative intent by endotherapy. Concerning
squamous cell cancer, the oriental and occidental pathologists include high-grade
dysplasia in the same group as intramucosal cancer. The distinction is however
maintained for adenocarcinoma in the Barrett's esophagus. Indications of
endoscopic rather than surgical treatment rely on: (1) the small size of the
tumor (not more than 2 cm in diameter); (2) the endoscopic morphology in the type
0 of the Japanese classification with the flat subtypes IIa and IIb rather than
type IIc--there is high risk of submucosal invasion for the polypoid (type I) or
ulcerated superficial cancer (type III); and (3) the endoscopic ultrasound
staging, with confirmed integrity of the hyperechoic submucosal layer. The high
frequency (20 MHz) miniprobe is preferred to the standard (7.5 MHz) instrument.
The elective procedure for tumor eradication is endoscopic mucosectomy. The
technique is associated with a 6.8% risk of severe complications (hemorrhage or
perforation) and a recurrence rate of 3%-7%. The 5-year survival rate is similar
to that of surgery (over 80%). In the small group of patients with superficial
esophageal cancer (less than 10% of the disease) endoscopic treatment may now be
proposed in about 30% of cases, surgery is preferred for submucosal cancer and
for neoplasia with a large surface. Areas of high-grade dysplasia in the
Barrett's esophagus offer a new and increasing sector of indications. The
concurrent endoscopic procedure of destruction--photodynamic therapy--is
preferred for the destruction of lesions with poorly delineated limits.
PMID- 10693253
TI - Quality of life in patients with oesophageal cancer.
AB - There is a growing interest in assessing quality of life in patients with
oesophageal cancer because it provides detailed information of the patients'
perception of the benefits or harms of treatment. Yet few studies have
prospectively measured quality of life using validated appropriate instruments.
There are now several questionnaires for patients with cancer, although these are
not sufficiently sensitive to small but clinically important changes in quality
of life. It is therefore recommended that a disease-specific module is used in
conjunction with generic measures. The European Organisation into Research and
Treatment of Cancer (EORTC) QLQ-OES24 is currently completing an international
validation study. It is used with the EORTC QLQ-C30 core instrument and is
designed for patients undergoing potentially curative treatment or palliation of
malignant dysphagia. Studies that have assessed quality of life after
oesophagectomy have generally found that survivors do regain their former health.
Little is known about the effect of neoadjuvant chemoradiation on patients'
quality of life. Following endoscopic palliation of dysphagia, quality of life
can be maintained and improvement of swallowing is seen. A validated appropriate
assessment of quality of life should be included in future palliative trials and
in studies of new treatments which may marginally influence survival but cause
significant side effects.
PMID- 10693254
TI - [How to examine a patient with Parkinson disease].
PMID- 10693255
TI - [Anti-neuronal antibodies and central nervous system diseases: contribution to
diagnosis and pathophysiology].
AB - Antibodies against antigens found in the central nervous system have been
evidenced in several neurological diseases. The most well-known are associated
with paraneoplastic neurological diseases (Anti-Hu, Yo, Ri amphiphysin, Tr, CV2
and Ta antibodies). Some of these antibodies are specific for certain types of
cancer or neurological syndromes and are highly useful diagnostic tools for the
clinician. They have contributed to the hypothesis that these paraneoplastic
neurological syndromes involve autoimmune cross reactions between tumoral and
nervous system antigens. They are however most unlikely pathogenic on their own.
Anti voltage-dependent calcium channel antibodies associated with Lambert-Eaton
syndrome which is paraneoplastic in only 60 p. 100 of the cases are also observed
in cases of paraneoplastic cerebellar atrophy. Anti-GAD antibodies are seen in
non-paraneoplastic stiff man syndrome and in certain progressive cerebellar
atrophies. Antibodies reacting with different glutamate receptors are detected in
different neurological diseases including Rasmussen's encephalitis. Finally,
antibodies are described in diverse conditions such as amyotrophic lateral
sclerosis, Sydeham chorea or Gilles de la Tourette syndrome. The significance of
the antibodies observed outside the context of paraneoplastic syndromes is not
well understood, but the anti-GAD antibodies associated with progressive
cerebellar disorders and autoimmune polyendocrinopathies could be an expression
of the autoimmune nature of certain neurological degenerative processes affecting
the central nervous system.
PMID- 10693256
TI - [True neurological thoracic outlet syndrome].
AB - The thoracic outlet syndrome (TOS) encompasses various clinical entities
affecting the neurovascular bundle crossing the thoracic outlet. Unfortunately,
this term often proves to be confusing because many of these entities have little
in common beyond their known or presumed lesion site. Neurogenic TOS (true TOS)
is caused by compression of the lower trunk in the brachial plexus, the cervical
ribs or fibrous band. This syndrome is extremely rare. We consider that this
neurological form of TOS is a clearly defined neurological syndrome. We report 10
patients with true TOS. All were females. Stating the onset was difficult because
symptoms were progressive and insidious. Pain was the most frequently reported
symptom. Sensory deficit was slight or absent. All patients showed unilateral
severe atrophy of the thenar muscles. Wasting and weakness developed later. A
reduced amplitude of ulnar and median compound muscle action potential associated
with a normal amplitude of median sensory nerve action and a reduced amplitude of
ulnar sensory nerve action potential were indicative of a chronic axon loss in
the lower trunk of the brachial plexus. In all cases, we performed medial
antebrachial cutaneous sensory nerve action potential, a C8-T1 innervated nerve.
The absence of the medial antebrachial cutaneous sensory nerve action potential
in 9 patients and a reduction in amplitude of 50 p. 100 compared to the
unaffected side in the other patient, indicated the diagnostic value of this easy
and reproductible test. It confirmed a C8-T1 post-ganglionic radicular lesion or
a lower brachial plexus neuropathy. Radiography showed a rudimentary bilateral
cervical rib or an elongated C7 transverse process in all cases. Surgery was
performed in the affected side in 7 patients and in each case the lower part of
the brachial plexus was found to be stretched and angulated over a fibrous band,
which was removed. Pain was relieved after 1 to 4 weeks. A minimal motor
improvement was observed after one year. Electrophysiological results were
unchanged.
PMID- 10693257
TI - [Case study of 199 patients with multiple sclerosis: the use of EDMUS program].
AB - European Database Multiple Sclerosis (EDMUS) is a standardized tool which allows
the collection of clinical, biological, radiological and therapeutic data on
multiple sclerosis (MS). A descriptive analysis of 199 patients was done using
EDMUS (version 2.2). Most data agreed with previous published results, except a
low 0.4 sex ratio. At the beginning of MS, 42 p. 100 of MS patients developed
pyramidal and sensory involvements and 14 p. 100 retrobulbar optic neuritis.
Optic neuritis was the most frequent initial symptom of relapsing-remitting MS
(25.9 p. 100) but not in the chronic progressive form (5.5 p, 100; p < 0.01).
Surprisingly, relapsing-remitting form occurred more frequently whereas the
secondary progressive form was diagnosed less. The concordances between the three
disability scales, EGS (EDMUS Grading Scale), EDSS (Expanded Disability Status
Score) and AI (Hauser Ambulation Index) were correct. In clinical practice, EDMUS
is user-friendly and rapid. The lack of radiological data and the necessary
quantification of only one disability scale, EGS may be too restrictive. The
analysis of most of clinical data is possible by using integrated selection
within the software, but sometimes needs more complex procedures.
PMID- 10693258
TI - [Evaluation of motor speech function in the diagnosis of various forms of
dysarthria].
AB - Perceptual analysis is not sufficient enough to identify specific dysarthria
types. In order to improve the discrimination between dysarthria types, we
developed a standardized evaluation of different functions controlling speech
motor performances. This was applied to 90 patients suffering from hypokinetic,
spastic or ataxic dysarthria and 15 control subjects. A discriminate analysis
showed that 71.4 p. 100 of the cases were correctly classified. This model was
validated within a new group of 21 patients and showed that the less severe
dysarthric parkinsonian patients were difficult to distinguish from control
subjects. The discriminate analysis was then used for 20 patients with atypical
parkinsonism. Seven patients with progressive supranuclear palsy were considered
to have hypokinetic dysarthria. The 6 patients with multisystem atrophy and 7
with corticobasal degeneration were classified among the 3 dysarthric types. We
suggest that motor speech evaluation may contribute to differential diagnosis
within groups of patients suffering from atypical parkinsonism.
PMID- 10693259
TI - [Chemotherapy of malignant inoperable gliomas. The association of fotemustine
cisplatine-etoposide as neoadjuvants].
AB - Efficiency of chemotherapy (CT) on non removable HGG has not been proven and
neoadjuvant brain irradiation (RT) following biopsy is the standard treatment. We
aimed to define whether combination of polychemotherapy and radiotherapy is
synergistic in non removable HGG. It has been proven that F, CDDP and VP16 can
reach therapeutic levels in brain after intravenous standard dose injections. The
aim of this study was to assess that (i) neoadjuvant CT is safe; (ii) feasibility
and efficacions of F (100 mg/m2.d1)/CDDP (100 mg/m2.d1-3 TD)/VP16 (75 mg/m2.d1-3)
q21-28d regimen; (iii) Delayed RT is not unsafe: RT was performed when tumor
progression or toxicity appeared. This study included 16 patients with
symptomatic non removable HGG. Two of them had anaplastic gliomas and 14
glioblastomas multiforme. None of them had a prior chemotherapy regimen.
Objective response was evaluated with CT scan or MRI during chemotherapy.
Toxicity was moderate and mainly hematological (grade III-IV thrombopenia = 10/67
cycles; leukopenia = 13/67). Objective response rates were 5/16 (31 p. 100) (CR =
1; PR = 4; Median duration of response: 20 weeks). Median survival was 55 weeks
in the 14 grade IV patients. Three/16 patients are still alived with respectively
22, 30, 40 months survival: These results confirm the neoadjuvant chemotherapy
efficacy. It may be a useful tool before RT for non removable HGG.
PMID- 10693260
TI - [Periodic hypokalemic paralysis as the manifestation of Graves' disease: clinical
and electrophysiological study].
AB - A 30-year-old Vietnamese man experienced severe weakness of four limbs revealing
hypokalaemia. Tachycardia and goiter allowed to diagnose a Graves' disease.
Thyrotoxic hypokaliemic periodic paralysis is a rare complication of
hyperthyroidism in western populations. Electromyogram performed after resolution
of the paralysis episodes revealed marked abnormalities of the muscular
excitability. Duration of compound muscular action potential was markedly
increased after a brief exercise. This increase might indicate a delayed
repolarization of muscle fibres.
PMID- 10693261
TI - [Polyradiculoneuropathy in an adult with primitive hyperoxaluria].
AB - From the age of 31 a patient began to suffer from recurrent calcium oxalate
urolithiasis. Liver biopsy showed a decrease in catalytic activity of the hepatic
peroxisomal enzyme alanine: glyoxilate aminotransferase (AGT), which was
mistargeted from peroxisomes to mitochondria. The genetic analysis revealed a
mutation of the AGT gene. At age 47 he developed end-stage renal failure and
underwent hemodialysis. After 12 months of hemodialysis he presented a rapidly
declining clinical condition, a decrease of the residual renal function, a livedo
reticularis with painful of extremities, and shortly thereafter a general
weakness, which predominated on lower limbs. Apart from renal failure, routine
biological examination and CSF were normal. Nerve conduction studies and
electromyography supported the diagnosis of polyradiculoneuropathy. Pathological
studies revealed mixed demyelinating-axonal lesions and deposits of calcium
oxalate crystals within the media and the intima of epineural arterioles. A
combined liver-kidney transplant was rapidly performed. The patient's condition
improved in a few months and motor signs completely disappeared.
PMID- 10693262
TI - [Neurological features after consumption of a variety of neo-caledonian
shellfish].
AB - A few days after a seafood meal a patient suffered ataxia and stupor. His
examination revealed a confused patient with cerebellar signs and ocular
disturbances (hypotropia). Blood results, cerebrospinal fluid and brain CT scan
were unremarkable. The patient developed a septic shock and died 4 weeks after
admission. No necropsy was performed. Questioning his family confirmed that he
had eaten a shellfish meal a few hours before onset of the digestive signs.
Trocas (Tectus pyramis) were definitely identified. The clinical picture strongly
suggested a seafood poisoning, namely ciguatera. However, no toxicologic assay
was performed. To our knowledge, this poisoning has never been reported with
trocas. Nevertheless, the feeding habits of trocas would suggest similarity with
ciguatera poisoning.
PMID- 10693263
TI - [Cerebral ischemia in the course of infectious endocarditis: a signal and a
marker of progression].
PMID- 10693264
TI - [The opsoclonus-myoclonus syndrome].
PMID- 10693265
TI - [Electrodiagnosis of neuromuscular junction diseases].
PMID- 10693266
TI - [The first consensus conference in alcohology: objectives, indications and
modalities for weaning the alcohol dependent patient].
PMID- 10693267
TI - [The dominant motivation in the mechanisms of the conditioned reflex].
AB - It is substantiated that the mechanisms of dominant motivations play an essential
role in conditioning. It is shown that motivations change convergent and chemical
characteristics of single neurons of different brain structures and, especially,
their sensitivity to corresponding reinforcing stimuli. As a result, motivation
plays a role of an initial "canvas", against the background of which molecular
"engrams of reinforcement" are built. The processes of interaction between the
dominant motivation and reinforcement are mainly addressed to the apparatus of
the action result acceptor. It is shown that dominant motivations participate not
only in construction of molecular reinforcement engrams but also in their
forestalling retrieval.
PMID- 10693268
TI - I. P. Pavlov and the development of neuroscience.
AB - Ivan Petrovitch Pavlov significantly changed and developed our knowledge of the
brain functions and of the behaviour by his fundamental experimental and
theoretical work on the physiology and pathophysiology of the higher nervous
activity. He was one of the scientists who prepared the development of
neuroscience in our century. During the Pavlovian Conference, 1950 in Moscow
Stalin and the Communist Party tried to dogmatize his and his pupil's fundamental
theories. But his pupils continued to develop Pavlovian ideas in open discussions
with representatives of other schools in a very creative way, opening the doors
for a system approach to understand the integrative functional systems of brain
and behavior. Pavlov emphasized the high plasticity of the central nervous
system. He investigated the complex functional systems within the brain and
between the organism and its environment, and the designed models for pathology
of the higher nervous activity. During his last years, Pavlov freed himself from
the strong deterministic view and characterized the organism and its environment
as a self-organizing system.
PMID- 10693269
TI - [I. P. Pavlov's theory on higher nervous activity: the landmarks and trends in
its development].
AB - The theory of higher nervous activity created in Pavlovian time is compared with
the present-day state of the theory developing due to appearance of new methods,
techniques, facts, and concepts. Three principles of Pavlovian theory:
determinism; analysis and synthesis; structural approach, as well s types of
conditioned reflexes and techniques, types of higher nervous activity, and
inhibition problems are discussed. The theory of higher nervous activity is
schematically depicted as a tree, some branches of which are presented by facts
and concepts obtained and introduced by I.P. Pavlov and his followers during his
life, the others are formed by new facts and concepts advancing the theory. What
is obsolete in the theory, what are the most prominent tendencies of its
development and its new branches are discussed.
PMID- 10693270
TI - [A physiologist's dialog with a psychologist].
AB - The famous polemics between I. P. Pavlov and K. S. Lashley in the pages of the
"Psychological Review" in the thirties is discussed in this paper. The particular
significance of this polemics for development of contemporary neuroscience is
underlined, since the essentially novel concept of the brain activity mechanisms
has been advanced and intelligence nature has been advanced on the basis of the
synthesis of the two opposing theories, the localizationalism and
equipotentialism.
PMID- 10693271
TI - [Generators of the rhythmic alpha activity in the human EEG].
AB - An attempt to localize brain mechanisms of the rhythmic activity in the alpha
rhythm range was made using the equivalent dipole model. It is known that light
flickering stimuli with the frequency close to that of the individual alpha
rhythm induce an increase in its spectral power ("photic-driving" phenomenon). It
was shown that the activity of the neuronal structures generating the alpha
rhythm can be identified by specific frequency of the light stimulation and
localized by means of construction of dipole models. Two sources of the alpha
rhythm in the narrow-frequency bands with the maximal resonance responses in the
frequencies of 10.1 and 10.5 Hz were localized in the thalamic structures.
PMID- 10693272
TI - [The characteristics of the electrodermal activity during changes in the level of
human wakefulness].
AB - The wake-drowsiness transition during the performance of a monotonous psychomotor
test was studied using polygraphic recording, with particular emphasis on changes
in the electrodermal activity (EDA) and occurrence of electrodermal reactions
(EDR). It was found that decrease in wakefulness was accompanied by a drop of the
EDA. The EDR gradually disappeared for several minutes and did not reappear
without activation; their dependence on sex and individual features of a subject
significantly increased. It is suggested that discrepancies in the experimental
results of psychophysiological studies with EDA may be explained by an
insufficient control of the subject's alertness throughout the experiment.
Examples of such discrepancies are given: disagreement of sex differences in the
EDA, differentiation between EDA-labile and EDA-stable persons, on a possibility
of recording the "emotional" EDA from different parts of human body etc. The ways
of reproducibility of the results are discussed including the recording of
several wake-drowsiness transitions and better recognition of the EDR.
PMID- 10693273
TI - [The emotional assessment by test subjects of short musical fragments].
AB - Emotional estimation of 96 short (2-5 s) musical fragments was studied in 6
healthy subjects. Fragments were scored on a 5-point scale. Statistically
significant difference in estimations of specific musical fragments (positive,
negative, or indifferent) was found.
PMID- 10693274
TI - [A clinical and neuropsychological analysis of mental functions in 6- to 7-year
old children].
AB - The neuropsychological analysis of the state of higher mental functions (HMF) in
children aged 6-7-years entering the first class of the school providing general
education showed that the HMF of 52-73% of the future schoolchildren are
underdeveloped with respect to their age. The underdevelopment of the emotional
volitional sphere, of the dynamic organization of object activity, audio-speech
memory, sphere of images-representations, visually-image and verbally-logical
forms of thinking has been revealed. The experimental data suggest the absence of
the primary (structural) derangements of the studied HMF in the examined children
and dependence of the extent of their formation on the extent of readiness of the
voluntary organization of activity. Insufficient formation of the HMF with
respect to age is manifested in the lag of the formation of the internal
structure of the psychic process, i.e., the absence of interiorization of the
psychic processes and formation of the internal mental act. The
neuropsychological assessment of underdevelopment of the HMF in reference to age
suggests an insufficient age-related maturity of subcortical structures and
subcortical corticopetal pathways as well as a dysfunction of the frontal
neocortex and a secondary dysfunction of the posterofrontal and TPO areas, non
auditory cortical temporal regions of the left hemisphere due to underdevelopment
of connections of these areas with the frontal structures.
PMID- 10693275
TI - [The physiological indices of emotional reactions in the clinical picture of
local brain lesions].
AB - The psychophysiological correlates of recognition and reproduction of emotional
states were studied in patients with differently localized lesions of the brain
cortex. It was shown that the effect of different lesions are anisotropic. The
cross and reciprocal interaction between the posteriofrontal and temporal regions
of the left and right hemispheres was described. A relation was revealed between
the emotion sign and different autonomic indices. A quantitative estimation of
physiological reactions of healthy persons and patients with focal brain
pathology was carried out.
PMID- 10693276
TI - [A physiological analysis of dissociative learning against a background of
physostigmine and pentobarbital].
AB - Physostigmine (0.7-0.8 mg/kg, i.p.) decreased and pentobarbital (13.4-14.6 mg/kg)
increased the locomotor and emotional activity of rats in the "open field". Both
drugs induced the reversible amnesia to a conditioned reaction in a double T-maze
with positive (nutritional) reinforcement. These changes in behavioral activity
were correlated with dissociated learning of rats after the injection of the
drugs: physostigmine largely decreased the number of errors during learning as
compared with pentobarbital. However, in both cases rats reached the learning
criterion sooner than the control animals due to the shorter reaction latency
(physostigmine) and increase in general motor activity (pentobarbital).
PMID- 10693277
TI - [The transmission of coded information over neuronal systems exemplified by the
motor rhythmic dominant].
AB - Functional organization of neurons in rabbit's sensorimotor cortex was studied
before and within several days after formation of the rhythmical dominant focus.
Functional reorganization of neurons in cortical microareas took place during
actualization of the dominant. The number of functional interneuronal relations
within neuronal pairs of a certain type could be increased in comparison with the
control values and decreased within pairs of another type. As a result, the total
percent of the interneuronal correlations in cortical microareas in the control
animals and rabbits with the acting dominant was approximately equal. The total
percent of correlations between neurons of the adjacent cortical areas during the
actualization of the dominant was significantly higher than in the control due to
increased number of correlations with participation of small and medium-sized
neurons. A possibility of information circulation about the "stimulus image" in
the closed chain of neurons was exemplified by the real micronetwork. The data
suggest the reverberation of encoded information between adjacent microareas of
the sensorimotor cortex within several days after application of the stimulus,
which has formed the excitation focus.
PMID- 10693278
TI - [The neurochemical mechanisms of the formation and consolidation of haloperidol
induced catalepsy].
AB - In rat brain cortex, haloperidol initiates the long-term potentiation of K(+)
induced Ca(2+)-dependent noradrenaline (NA) and dopamine (DA) secretion in vitro
and in vivo. In both cases, the long-term potentiation is caused by the long-term
increase in catecholamine content in the NA and DA terminals, as it has been
shown in cortical tangential slices. Acute intraperitoneal haloperidol injection
(2.5 mg/kg) evokes catalepsy and increases the content of NA and DA in the brain
structures with localization of catecholamine receptors on terminals. This
increase appears to be caused, predominantly, by modification of the terminal DA
receptors, since only a trend to catecholamine increase is observed in the brain
structures with a mixed type of NA and DA receptor localization (on somata and
terminals). It is suggested that the long-term and diffuse action of haloperidol
after its acute administration consists in the anxiogenic reaction and
consolidation of catalepsy without an additional procedure of training and in the
absence of unconditioned stimulus.
PMID- 10693279
TI - [Generalized posttetanic changes in the excitatory postsynaptic and acetylcholine
evoked currents in snail neurons].
AB - Heteroreceptor posttetanic changes in excitatory postsynaptic currents (EPSC) and
inward currents evoked by the local iontophoretic application of acetylcholine
(ACh) on the dorsal surface of PLa3 and PRa3 Helix lucorum neurons were studied.
The following changes in the currents were revealed over the course of 1-1.5 h
after tetanization. The rhythmical ACh application (0.5-1.0 cps, 10-40 s) evokes
potentiation of the orthodromic EPSC. The tetanic orthodromic stimulation of one
of the nerves (n. intestinalis, n. pallialis dexter, or n. pallialis sinister; 1
5 cps, 1-2 min) causes the potentiation of the ACh current and also
heterosynaptic depression of the EPSC. It is concluded that activation of
subsynaptic and nonsynaptic neurotransmitter chemoreceptors evokes the
development of generalized posttetanic changes in neuronal responses.
PMID- 10693280
TI - [Latent contextual inhibition of the cardiac component in the startle reaction to
a sound stimulus in rats].
AB - Heart rate (HR), freezing score, and motor component were estimated during
acoustic startle (ASR) habituation (two sessions with 24-hour interval, 10 trials
in a session). It was shown that rats previously exposed to the experimental
context (once for 5 min 24 h before training) demonstrated HR decrease in
response to the first stimulus and tachycardia in response to the 4th-10th
stimuli during the first session. The interstimulus HR declined from the 4th to
the 6th trials. The same profile of cardiovascular response was observed in this
group at the beginning of the second session with the following (to the 7th
trial) habituation of tachycardia. These rats didn't demonstrate the intertrial
HR decrease during the second session. Nonadapted rats responded by bradycardia
to the 1st and 2nd trials of the first session. The response didn't change for
tachycardia with continuation of stimuli presentation. Tachycardia appeared only
in response to the 7th-10th trials of the second session and didn't habituate.
The intertrial HR level decreased in this group only during the second session.
The results are discussed in terms of contextual latent inhibition of the cardiac
acoustic startle response.
PMID- 10693281
TI - [The characteristics of the manifestation of hereditarily induced anxiety in male
C57Bl/6J and CBA/Lac mice].
AB - Behavior of male mice of C57Bl/6J and CBA/Lac strains was tested in the elevated
plus-maze and open field in order to estimate state anxiety in novel conditions.
The cube and partition tests were used to reveal trait anxiety in the familiar
conditions of the home cage. It is concluded that genetically defined state
anxiety is more pronounced in CBA/Lac mice and trait anxiety in C57Bl/6J strain.
PMID- 10693282
TI - [Anxiety and behavior in WAG/Rij strain rats with genetically induced absence
attacks].
AB - Behavior of nonlinear rats and animals from Wistar and WAG/Rij (with inborn
generalized absence epilepsy) strains was examined in the elevated plus-maze and
the hole board. WAG/Rij rats demonstrated low exploratory behavior in both tests.
In the elevated plus-maze, WAG/Rij rats were more balanced and more anxious than
Wistar and nonlinear rats. Administration of ethosuximide completely eliminated
spike-wave discharges but did not change behavioral interstrain differences.
Since the spike-wave patterns develop in WAG/Rij at the age of 3 months, the
behavior of young (2-moth-old) pups from different strains was compared and
significant differences were revealed. Correlation between the genetically
defined features (spike-wave discharges) and behavioral peculiarities in WAG/Rij
rats is supposed.
PMID- 10693283
TI - [The effect of alcoholization on the behavioral reactions of rats in an 8-arm
radial maze].
AB - The influence of 20% alcohol consumption on training of low-active rats in 8-arm
radial maze was studied. One group of animals was trained before and the other
group after the alcoholization. All the animals acquired the conditioned reaction
in the radial maze. However, the behavioral difference between the groups
consisted in spatially-motor asymmetry. The rats trained before the alcohol
consumption had less stereotyped behavior and more distinctly preferred to enter
the maze arms at the angle of 45 degrees than the animals trained after the
alcohol consumption. After the alcohol consumption, rats more frequently refused
from behavioral task performance in comparison with the animals trained after the
alcoholization. The influence of alcohol consumption of learning and memory in
low-active rats is discussed.
PMID- 10693284
TI - [The effect of different stages of the sex cycle on rat behavior in a plus maze].
AB - Anxiety and motor activity of female white rats in the elevated plus-maze were
studied at different stages of the reproduction cycle (estrus, diestrus,
pregnancy and lactation). The level of anxiety was lower, and that of locomotor
and exploratory activity was higher during estrus and lactation than during
diestrus and pregnancy. Exposure to chronic pain of threshold intensity did not
induce behavioral changes in pregnant rats. There was no difference between the
control and experimental animals in the level of plasma corticosterone.
PMID- 10693285
TI - [The brightness components of the visual evoked potential to color stimuli in the
rabbit].
AB - Two earliest components of visual evoked potentials (N85 and P130) which were
related with substitution of stimuli for those identical in spectra but different
in brightness were detected in rabbits. This finding suggests an analogy between
the N85 and P139 in rabbits and N87 and P120 in humans.
PMID- 10693286
TI - [The effect of scopolamine on the spatial organization of rat cortical
potentials].
AB - The influence of scopolamine (1 mg/kg, i.p.) on the spatial organization of the
neocortical electrical activity was studied in rats. A decrease in the spectral
power and coherence of brain potentials in the range of the dominant theta-rhythm
peak (6.00-7.25 Hz) and their increase in the adjacent low-frequency band were
observed. Both indices were decreased in the wide beta band (19.00-30.00 Hz). The
described changes took place over the whole areas of the right hemisphere and
parieto-temporal region of the left hemisphere. The obtained results are
discussed with respect to the role of the cholinergic brain system in the higher
nervous activity.
PMID- 10693287
TI - [Changes in the direct and interhemispheric responses of the pyramidal tract
after tetanization of the cortex and lateral hypothalamus].
AB - Changes in pyramidal tract response after unilateral neocortical and lateral
hypothalamic tetanization were analyzed in unanesthetized and nonimmobilized
rabbits. Membrane and synaptic modifications were revealed in intra- and
interhemispheric connections. Changes in excitability of callosal collaterals of
pyramidal tract neurons in contralateral hemisphere and changes in
somatodendritic excitability in ipsilateral hemisphere could be oppositely
directed. Plasticity of callosal connections may contribute to the
interhemispheric asymmetry during learning.
PMID- 10693288
TI - [The duration of the storage of the electrical characteristics of command neurons
in the acquisition of long-term sensitization in the snail].
AB - The retention of the long-term sensitization (LTS) of defensive reflex and
dynamics of change in electric characteristics (membrane potential (Vm) and
action potential generation threshold (Vt)) of command neurons of defensive
reflex was studied in a snail during behavioral tests. The membrane mechanisms
were analyzed by measuring electrical characteristics of the LPa3, RPa3, LPa2,
and RPa2 command neurons on the 1st, 4th, 7th, 10th, and 14th days after the LTS
formation and 1 month later. The membrane potential and threshold potential in
sensitized snails (-54.1 +/- 2.0 and 24.5 +/- 1.4 microV, respectively) were
significantly (p < 0.001) decreased in comparison with the control animals (-60.9
+/- 0.8 and 19.9 +/- 0.6 microV respectively). These changes retained within 14
days after the LTS formation. The results suggest the long-term retention of the
increased excitability of command neurons. A month after the LTS formation, the
duration of the defensive reflex returned to the initial level and the electric
characteristics of command neurons did not significantly differ from the control
(-61.1 +/- 2.0 and 19.3 +/- 1.4 microV, respectively).
PMID- 10693289
TI - [The interrelations of I. P. Pavlov and M. V. Nesterov].
PMID- 10693290
TI - Application of CT imaging for dental implant simulation.
AB - Accurate diagnosis and exact treatment planning are very important for successful
implant treatment. Pretreatment examination and simulations using CT can be
especially effective information sources, and diagnosis by CT imaging before
treatment substantially enhances the security and safety of the treatment plan.
New interactive CT software (SIM/Plant) which enables diagnosis of bone
morphology and quality, and also implant simulation on a personal computer
through multiplanar reformation of CT images, has been developed.
Stereolithography models (SLMs) are reproduced anatomical morphological models of
an individual patient's bone structure from the information obtained by the CT
scan, and is fabricated out of light cure resin. In this article, SLMs and
SIM/Plant for simulation of various examinations and diagnosis incorporating CT
information are described, and their features are introduced.
PMID- 10693291
TI - IL-6 levels in gingival crevicular fluid (GCF) from patients with non-insulin
dependent diabetes mellitus (NIDDM), adult periodontitis and healthy subjects.
AB - Cytokines play an important role in the pathology associated with chronic
inflammatory diseases. One of these cytokines, interleukin 6 (IL-6) is a major
mediator of the host response to tissue injury, infection and bone resorption. In
the present study, gingival crevicular fluid (GCF) level of IL-6 was determined
in patients with non-insulin dependent diabetes mellitus (NIDDM) with
periodontitis, adult periodontitis, and healthy controls by use of an enzyme
linked immunosorbent assay (ELISA). Twenty-four NIDDM patients with
periodontitis, twenty-four adult periodontitis and twenty-four healthy controls
were selected for the study. GCF sampling was performed on the vestibular aspects
of maxillary incisors and canine teeth. Plaque index (PI), gingival index (GI),
gingival bleeding time index (GBTI), probing depth (PD) and probing attachment
levels (PAL) were recorded from each sampling area and also the entire dentition.
NIDDM and adult periodontitis patients had numerous sites with radiographic
evidence of alveolar bone resorption, loss of attachment and pocket depth greater
than 3 mm. The mean GCF IL-6 level was 2.43 +/- 0.97 ng/ml in NIDDM patients,
1.31 +/- 0.92 ng/ml in adult periodontitis and 0.62 +/- 0.58 ng/ml in healthy
subjects, respectively (p < 0.05). GCF IL-6 levels were markedly higher in NIDDM
and adult periodontitis groups compared to the healthy controls. No correlation
was found between GCF IL-6 levels and all clinical parameters. These findings
suggested that GCF IL-6 levels were significantly higher in the area of
inflammation and periodontal destruction locally. The high IL-6 levels in NIDDM
patients might be due to different microbial flora in periodontal pockets and
altered immune system. Future studies are needed to evaluate the complex
interaction among IL-6 GCF levels, host response and local microbial environment
in the NIDDM patients.
PMID- 10693292
TI - The phenomenon of salivary protein adsorption onto Streptococcus mitis ATCC 903
cells.
AB - It is thought that salivary proteins on bacterial cells have some influence on
the adhesion of oral bacteria onto the surface of oral tissues and on bacterial
aggregation. Initially, this study sought to examine the phenomenon of salivary
protein adsorption to the surface of Streptococcus mitis ATCC 903 using 3H
labeled salivary proteins. We investigated the effects of hydrophobic level and
lectin-ligand binding on adsorption of salivary proteins, and also the influence
of cell surface components on adsorption. The results showed that the adsorption
of salivary proteins was clearly reduced by the presence of Tween 20, LiCl,
NaSCN, Hexadecane and some sugars. The adsorption was also affected by the pH
level, and protease treatment or heat treatment of cells also decreased the
volume of adsorbed proteins. Although the adsorption of proteins onto heat
treated cells was dramatically reduced by the presence of LiCl and NaSCN, the
presence of sugars had little influence on this adsorption. These findings
suggest that the main adsorption of salivary proteins is due to hydrophobic
factors, and the heat-sensitive surface components of the cells had some relation
to lectin-ligand binding. Therefore, it appears important to study the adsorption
of salivary proteins onto cells since the salivary proteins on bacterial cells
play an important role in their adherence to the saliva-coated oral tissues and
bacterial aggregation.
PMID- 10693293
TI - Clinicopathological studies of odontoma in 47 patients.
AB - A 14-year retrospective study was performed on 47 odontomas from the files of the
1st Department of Oral and Maxillofacial Surgery at Nihon University School of
Dentistry. Fifty-seven percent of the patients were male and 42.6% were female.
The age distribution was 8 to 48 years with a mean age of 22 +/- 9.0 years. There
were no particular symptoms associated with the odontomas, and 63.8% of our
patients had no symptoms. However, 12 patients complained of swelling and 9 of
pain. The tumor was found in the maxilla in 42.6% and in the mandible in 57.4%.
According to the WHO histological type classification, 53.2% of the tumors were
classified as compound odontoma and 46.8% as complex odontoma. The size of the
tumor ranged from 5 mm to 42 mm in diameter. The average complex odontoma was
much bigger than the average compound odontoma. Ghost cells were found 11 cases
in our series. In addition, odontogenic epithelium was found in 16 cases. Twenty
seven patients had impacted teeth in association with odontoma and 24 of the 27
teeth were removed at the time of surgical enucleation of the tumor, while 3
cases were treated by orthodontically assisted eruption. There was no recurrence
in any of the studied cases.
PMID- 10693294
TI - Histological assessment of root cementum at periodontally healthy and diseased
human teeth.
AB - This study aimed to investigate and compare the lipid and polysaccharide content
of the cemental surfaces of healthy and periodontally-involved teeth. Thirty
periodontally-involved single-rooted teeth from fifteen patients with localized
juvenile, adult and rapidly progressive periodontitis were included in the
experimental group and 5 healthy teeth were assessed in the control group. Frozen
serial sections were obtained and stained with hematoxylin-eosin for
morphological assessment. Oil-Red-O and Alcian Blue-Periodic Acid Schiff stains
were used to evaluate the presence of lipids, neutral and acidic polysaccharides
using light microscopy. It was found that with hematoxylin-eosin staining in the
experimental group, both the involved and uninvolved cementum surfaces of teeth,
which belong to all periodontitis groups, showed generally irregular surfaces
that contain some resorption areas. Alcian Blue-Periodic Acid Schiff positive
staining was observed only superficially and at the areas associated with
microbial dental plaque. However, Oil-Red-O staining was positive only
superficially at 5 teeth that belonged to localized juvenile and rapidly
progressive periodontitis groups. Apparent lipopolysaccharide staining into
cementum was not seen in any of the diseased teeth. The results presented here
suggest that endotoxin was only localized in superficial layers and associated
with only microbial colonization.
PMID- 10693295
TI - Treatment of ligature-induced peri-implantitis defects by regenerative
procedures: a clinical study in dogs.
AB - We carried out a clinical evaluation of the hard tissue fill following treatment
of ligature-induced peri-implantitis in dogs. Four dogs were used and their
mandibular premolars (P2, P3 and P4) were removed. After 3 months of healing, two
titanium implants were placed on each side of the mandible. After 3 months, the
abutment connection was performed, and experimental peri-implantitis was induced
by placement of cotton ligatures in a submarginal position. The ligatures and
abutments were removed after one month, and the peri-implant bone defects were
assigned randomly to one of the treatments: debridement (control), debridement
plus guided bone regeneration (GBR), debridement plus mineralized bone graft
(BG), and debridement plus guided bone regeneration associated with a mineralized
bone graft (GBR + BG). Clinical measurements of the peri-implant bone defects
before and 5 months after treatment revealed no statistically significant
differences between the defects treated by GBR, BG and GBR + BG. These 3
treatment methods provided more hard tissue fill than debridement alone (p <
0.05). Thus, it can be concluded that GBR, BG or a combination of the two
techniques can enhance the hard tissue fill in defects caused by peri-implantitis
in dogs.
PMID- 10693296
TI - Beta-lactamases producing anaerobic bacteria in dentoalveolar abscesses.
AB - Pus samples of 30 patients with closed dentoalveolar abscesses who had not
received antimicrobial therapy for at last two months were screened for the
presence of beta-lactamase-producing anaerobic bacteria. From these 30 pus
samples, a total of 112 bacterial strains were isolated; 83 of them were strict
anaerobes and 29 were aerobes. beta-lactamases activity of the selected anaerobic
bacteria was tested after identification of the isolates and was detected in 5 of
the total 83 (6%) strict anaerobic isolates, whereas these 5 strains were
isolated in 4 of the 30 (13.3%) pus samples. The species with beta-lactamase
activity were in the Prevotella intermedia (4 from 14 isolates) and the
Fusobacterium nucleatum (1 from 9 isolates) groups. None of the gram-positive and
the other gram-negative anaerobic strains were beta-lactamase positive.
PMID- 10693297
TI - Evaluation of human tooth structure with the ultrasonic imaging technique.
AB - In recent years, ultrasonic waves have been an interesting subject for studies
due to their wide range of applications in medical diagnoses. In this study, the
acoustic properties of the structure of human teeth was determined with the
ultrasonic imaging technique. This study may offer some fundamental findings
related to the clinical application of the ultrasonic imaging technique in the
further development of a virtual system for dental education and research. Twenty
freshly-extracted permanent human teeth (10 molars and 10 premolars) were used to
investigate their acoustic velocity and impedance by the ultrasonic image
analyzing system with a high-resolution focusing probe. Additionally, the
relationship between the acoustic properties and the hardness of the teeth was
evaluated. It was found that the acoustic properties of the human teeth were
influenced by factors related to their structure, such as degree of
calcification, distribution of dentinal tubules, and volume of the dentin matrix.
The acoustic velocity and impedance showed an apparent correspondence to the
hardness of tooth. This analyzing system provides visual information related to
tooth structure that can easily quantitatively evaluate their acoustic
properties. It is expected that this system will have a wide range of
applications and be further developed for clinical uses.
PMID- 10693299
TI - At the end of life: giving thanks and forgiving.
PMID- 10693298
TI - Supernumerary teeth with eumorphism in the lower incisor region: a report of five
cases and a review of the literature.
AB - Five cases of supernumerary teeth with eumorphism in the lower incisor region of
the permanent dentition are reported. The patients were two males and three
females. One (a 31-year-old woman) of them had bilateral supernumerary teeth. The
review of the English language literature yielded only one such bilateral
supernumerary teeth in the lower incisor region of the permanent dentition was
reported.
PMID- 10693300
TI - What constitutes high-quality HIV/AIDS palliative care?
AB - The study assessed the components of high-quality HIV palliative care using the
multidimensional model of quality assessment developed by Maxwell (4). Data
collection consisted of interviews with individual subjects and focus groups. The
interviews took place in three London health authorities. Seven service users and
74 providers of health care and voluntary services were interviewed. Maxwell's
model identifies the components of high-quality HIV palliative care as:
competent, skilled practitioners (effectiveness); confidential, non
discriminatory, and culturally sensitive care (acceptability); collaborative and
coordinated care (efficiency); flexible and responsive care (access and relevance
to need); and fair access for all clients (equity). Our results show that the six
dimensions of quality appear to be inextricably linked from the client's point of
view. Thus, service commissioners and providers need to examine all six of the
dimensions when assessing the quality of HIV services. These findings may serve
as a model for other palliative care services.
PMID- 10693301
TI - Age is not the crucial factor in determining how the palliative care needs of
people who die from cancer differ from those of people who die from other causes.
AB - A belief that the hospice philosophy is particularly applicable to younger people
may account in part for the continued focus of palliative care on cancer
patients, as it has been argued that age is the crucial factor in determining how
cancer and non-cancer patients differ. We conducted a secondary analysis of the
data from a UK population-based retrospective survey, the Regional Study of Care
for the Dying, to critically examine this proposition. The sample comprised 2062
cancer and 1471 non-cancer deaths. On average cancer patients were younger.
However, at all ages non-cancer and cancer patients differed significantly with,
for example, different patterns of dependency and symptomatology. The cause of
death--rather than age--is therefore the principal difference between cancer and
non-cancer patients. The debate within palliative care on whether and how to
provide services for non-cancer patients must move beyond a focus on group
differences such as age between these and cancer patients and focus instead on
understanding the varying problems non-cancer patients experience, and addressing
how best to organize palliative care services to meet the individual needs of
these patients.
PMID- 10693302
TI - Acupuncture for patients in hospital-based home care suffering from xerostomia.
AB - A total of 20 patients (17 cancer patients) in late-stage palliative care
reporting dryness of mouth and associated problems were treated for 5 weeks with
10 acupuncture treatments. Ten patients were also evaluated for speech problems
(articulation) and dysphagia caused by xerostomia. Subjective assessments used
Visual Analog Scales (VAS). Acupuncture had a dramatic effect on xerostomia and,
subsequently, on dysphagia and articulation, with subjects showing definite
improvement after 5 treatments. Release of neuropeptides that stimulate the
salivary glands and increased blood flow are possible explanations for the
effects.
PMID- 10693303
TI - Symptoms as meaningful "family culture" symbols in palliative care.
PMID- 10693304
TI - Terminal cancer syndrome: myth or reality?
PMID- 10693305
TI - Are some palliative care delivery systems more effective and efficient than
others? A systematic review of comparative studies.
PMID- 10693306
TI - Predictors of family satisfaction with an Australian palliative home care
service: a test of discrepancy theory.
AB - Five interesting findings emerged from this study: Although study results
demonstrate support for Porter's Discrepancy Theory, the most compelling outcome
is the finding that family care perceptions may be the best predictor of family
care satisfaction. Family members' age may be a predictor of family care
satisfaction. Family functioning may be a useful clinical indicator to identify
families who are less satisfied with care and in greater need of support. The
length of time that clients receive the care service may alter family care
satisfaction. Differences in findings reported in this study compared with
Canadian results point to the need for cross-cultural research in this area. This
research is the first Australian study to test discrepancy theory as a framework
for understanding family care satisfaction in a home hospice context. Results
from this study may assist health care providers to more sensitively address the
care perceptions of families in this care setting and extend theory development
research that is needed to guide palliative care practice with families.
PMID- 10693307
TI - Practitioners' attitudes towards ethical issues at the end of life: is the UK
actually more autonomy-minded than the US?
PMID- 10693308
TI - Traditions associated with dying in the west of Scotland.
PMID- 10693309
TI - Care for Chinese palliative patients.
PMID- 10693310
TI - Increased awareness of osteopathic medicine is essential to the profession's
survival.
PMID- 10693311
TI - 'Unity' benefits extend beyond AOA public relations programs.
PMID- 10693312
TI - In defense of Dr Kevorkian.
PMID- 10693313
TI - Osteopathy an independent system co-extensive with the science and art of
healing. 1901.
PMID- 10693314
TI - Troponin I sensitivity and specificity for the diagnosis of acute myocardial
infarction.
AB - This article describes the sensitivity and specificity of troponin I when
compared to creatine kinase-MB (CK-MB) and electrocardiography (ECG) for
diagnosing acute myocardial infarction (AMI). Two different lower levels for
defining positive results with troponin I were evaluated. A retrospective study
of 153 patients who presented to the emergency department of a community hospital
supplied the pool of patients for this study. Patients included in this study
were those for whom a CK-MB was ordered. The majority of these patients were
evaluated for chest pain or symptoms suggesting an acute cardiac event. Of the
153 patients studied, CK-MB results were positive in 91 (59%) patients; ECG
revealed AMI in 72 (47%) patients. There were 103 (67%) patients who had either
positive CK-MB or ECG results. Ninety (59%) patients had a troponin I level
greater than 2.0 ng/mL, and 18 (12%) patients had a troponin I level between 0.6
and 2.0 ng/mL. Seven patients whose troponin I level was between 0.6 and 2.0
ng/mL had negative CK-MB and ECG results. Therefore, 11 patients with troponin I
between 0.6 and 2.0 ng/mL had AMI. Five patients with positive troponin I results
(> 2.0 ng/mL) had negative CK-MB and ECG results. When a troponin I level greater
than 0.6 ng/mL was used as a positive value, compared to CK-MB and ECG using
either time zero or time 6 hours, the sensitivity was 94% and specificity was
81%. When troponin I greater than 2.0 ng/mL was used to define a positive test,
the sensitivity was 85% and specificity was 91% when compared to CK-MB and ECG.
PMID- 10693315
TI - Role of antileukotriene agents in asthma therapy.
AB - Leukotrienes are proinflammatory mediators with special significance in asthma.
Released by numerous cell types, particularly after exposure to allergens,
leukotrienes cause a potent contraction of bronchial smooth muscle, resulting in
reduced airway caliber. Further, they cause plasma to leak from the vessels,
resulting in edema, and enhance the secretion of mucus--both events that increase
airway obstruction. Thus, leukotrienes have been a target of basic research in
asthma. To date, a number of antileukotriene agents have been developed, and
three are currently being used in clinical practice in the United States:
zafirlukast and montelukast act by antagonizing the leukotriene receptor, and
zileuton inhibits leukotriene synthesis. Studies have shown that these agents
improve asthma symptoms, pulmonary function, and patient quality of life.
Antileukotriene agents have generally been associated with a low incidence of
side effects and good tolerability. Currently recommended for mild-to-moderate,
persistent asthma, these agents have enabled patients to reduce their use of
corticosteroids.
PMID- 10693316
TI - Advances in forensic assessment and treatment: an overview and introduction to
the special issue.
PMID- 10693317
TI - The quality of forensic psychological assessments, reports, and testimony:
acknowledging the gap between promise and practice.
AB - During the past decade, the field of forensic psychological assessment entered a
period of standard setting, reflected in the publication of specialty guidelines
for practice and in the proliferation of educational opportunities, training
programs, and credentialing and certification procedures for forensic examiners.
Representing significant efforts to advance the quality of psychological
assessments in legal contexts, these developments foreshadow the promise of
forensic assessment. During this same time period, new evidence emerged regarding
the quality of forensic practice. This article reviews this evidence and
evaluates current practice against the promise of forensic assessment. Forensic
reports appear to be of higher quality than those described by commentators in
the 1970s and early 1980s; nevertheless, the level of practice falls far short of
professional aspirations for the field. The review identifies significant areas
of weakness that demand the attention of professional organizations, accrediting
agencies, educators, lawmakers, practitioners, and consumers.
PMID- 10693318
TI - Psychopathy (PCL-R) as a predictor of violent recidivism among criminal offenders
with schizophrenia.
AB - Hare's Psychopathy Checklist--Revised (PCL-R) was used to test the hypothesis
that psychopathy predicts violent recidivism in a cohort subjected to forensic
psychiatric investigation and consisting of male violent offenders with
schizophrenia (N = 202). Psychopathy was assessed with retrospective file-based
ratings. Mean follow-up time after detainment was 51 months. Twenty-two percent
of the offenders had a PCL-R score > or = 26 (cutoff), and the base rate for
violent recidivism (reconvictions) during follow-up was 21%. Survival analysis
revealed that psychopathy was strongly associated to violent recidivism (log-rank
= 17.71, df = 1, p < 0.0001). The area under the curve (AUC) of the receiver
operating characteristics (ROC) of PCL-R total score to predict violent
recidivism varied between different time frames from .64 to .75. Cox regression
analyses revealed that other potential risk factors could not equally well or
better explain violent recidivism in the cohort than psychopathy as measured by
PCL-R.
PMID- 10693319
TI - Development and validation of the Validity Indicator Profile.
AB - The Validity Indicator Profile (VIP; Frederick, 1997) is a two-alternative forced
choice (2AFC) procedure intended to identify when the results of cognitive and
neuropsychological testing may be invalid because of malingering or other
problematic response styles. The test consists of 100 problems that assess
nonverbal abstraction capacity and 78 word-definition problems. The VIP attempts
to establish whether an individual's performance in an assessment battery should
be considered representative of his or her true overall capacities (valid or
invalid). Performances classified as valid are classified as "compliant" and
reflect a high effort to respond correctly. Performances classified as invalid
are subclassified as "careless" (low effort to respond correctly), "irrelevant"
(low effort to respond incorrectly), or "malingering" (high effort to respond
incorrectly). The VIP development sample included 944 nonclinical participants
and 104 adults undergoing neuropsychological evaluation. The cross-validation
sample consisted of 152 nonclinical participants, 61 brain-injured adults, 49
individuals considered to be at risk for malingering, and 100 randomly generated
VIP protocols. The nonverbal subtest of the VIP demonstrated an overall
classification rate of 79.8%, with 73.5% sensitivity and 85.7% specificity. The
verbal subtest of the VIP demonstrated an overall classification rate of 75.5%,
with 67.3% sensitivity and 83.1% specificity.
PMID- 10693320
TI - A classification tree approach to the development of actuarial violence risk
assessment tools.
AB - Since the 1970s, a wide body of research has suggested that the accuracy of
clinical risk assessments of violence might be increased if clinicians used
actuarial tools. Despite considerable progress in recent years in the development
of such tools for violence risk assessment, they remain primarily research
instruments, largely ignored in daily clinical practice. We argue that because
most existing actuarial tools are based on a main effects regression approach,
they do not adequately reflect the contingent nature of the clinical assessment
processes. To enhance the use of actuarial violence risk assessment tools, we
propose a classification tree rather than a main effects regression approach. In
addition, we suggest that by employing two decision thresholds for identifying
high- and low-risk cases--instead of the standard single threshold--the use of
actuarial tools to make dichotomous risk classification decisions may be further
enhanced. These claims are supported with empirical data from the MacArthur
Violence Risk Assessment Study.
PMID- 10693321
TI - The Spousal Assault Risk Assessment (SARA) Guide: reliability and validity in
adult male offenders.
AB - We evaluated the reliability and validity of judgments concerning risk for
violence made using the Spousal Assault Risk Assessment Guide (SARA; Kropp, Hart,
Webster, & Eaves, 1994, 1995, 1998). We analyzed SARA ratings in six samples of
adult male offenders (total N = 2681). The distribution of ratings indicated that
offenders were quite heterogeneous with respect to the presence of individual
risk factors and to overall perceived risk. Structural analyses of the risk
factors indicated moderate levels of internal consistency and item homogeneity.
Interrater reliability was high for judgments concerning the presence of
individual risk factors and for overall perceived risk. SARA ratings
significantly discriminated between offenders with and without a history of
spousal violence in one sample, and between recidivistic and nonrecidivistic
spousal assaulters in another. Finally, SARA ratings showed good convergent and
discriminant validity with respect to other measures related to risk for general
and violent criminality.
PMID- 10693322
TI - Improving risk assessments for sex offenders: a comparison of three actuarial
scales.
AB - The study compared the predictive accuracy of three sex offender risk-assessment
measures: the RRASOR (Hanson, 1997), Thornton's SACJ-Min (Grubin, 1998), and a
new scale, Static-99, created by combining the items from the RRASOR and SACJ
Min. Predictive accuracy was tested using four diverse datasets drawn from Canada
and the United Kingdom (total n = 1301). The RRASOR and the SACJ-Min showed
roughly equivalent predictive accuracy, and the combination of the two scales was
more accurate than either original scale. Static-99 showed moderate predictive
accuracy for both sexual recidivism (r = 0.33, ROC area = 0.71) and violent
(including sexual) recidivism (r = 0.32, ROC area = 0.69). The variation in the
predictive accuracy of Static-99 across the four samples was no more than would
be expected by chance.
PMID- 10693323
TI - Expert approaches to communicating violence risk.
AB - There has been virtually no empirical study of the way in which evaluating
clinicians communicate their conclusions about the risk of violence toward
others. Risk communication has become particularly important in recent years,
serving as the link between empirical data from recent studies and the
understanding and use of such data by evaluators and decision makers. The present
study considered how psychologists and psychiatrists, identified as experts in
violence risk assessment, responded to eight vignettes that systematically
measured preferences for risk communication. The vignettes involved the
presentation of the following factors in a 2 x 2 x 2 within-subjects design,
counterbalanced for order: (1) risk model (prediction vs. management), (2) risk
level (high vs. low risk of the individual being assessed), and (3) risk factors
(the predominance of static vs. dynamic risk factors). A total of 71 individuals
(41 psychologists, 2 sociologists, and 28 psychiatrists) responded to a survey
mailed to 100 individuals, for a response rate of 71%. Participants were asked to
rate the value of six forms of risk communication for each of the eight
vignettes. There were few significant differences between the ratings assigned by
psychologists and those assigned by psychiatrists. The most highly valued form of
risk communication involved identifying risk factors applicable to the individual
and specifying interventions to reduce risk. A repeated-measures multivariate
analysis of variance yielded a main effect for risk level and an interaction
between risk level and risk factors. The implications of these findings for
research and practice are discussed.
PMID- 10693324
TI - Distribution, density, and structure of muscle spindles in the vastus intermedius
and the peroneus longus muscles of sheep.
AB - Muscle spindles are not always distributed more in postural muscles with many
slow-twitch-oxidative (SO) myofibers than in locomotory muscles with few SO
myofibers. The purpose of present study was to examine the distribution, density,
and structure of muscle spindles in the vastus intermedius muscle: an antigravity
muscle and the peroneus longus muscle: a locomotory muscle in the sheep. Muscle
spindles were reconstructed from serial sections at 300 microns intervals
throughout the muscles. Myofiber types were classified into SO, fast-twitch
oxidative-glycolytic, and fast-twitch-glycolytic myofibers by differences in
histochemical reactivity. No significant difference in the density of muscle
spindles (DMS) existed between the vastus intermedius (DMS: 5.3) and peroneus
longus (DMS: 5.7) muscles. The muscle spindles were distributed more in the
distal portion than in the proximal portion of the vastus intermedius muscle. The
muscle spindles were distributed in the proximal and middle portion but hardly in
the distal portion of the peroneus longus muscle. Muscle spindles were classified
into simple, tandem, and compound muscle spindles. Most of the muscle spindles
were the simple type. The differences in size of the muscle spindle and numbers
of the intrafusal myofibers were not significant between the two muscles. The
results show that the density and structure of the muscle spindles do not differ
between the postural and locomotory muscles in the sheep.
PMID- 10693325
TI - Macrophages in the hamster parathyroid gland: immunohistochemical and
ultrastructural investigations.
AB - The distribution and morphology of the parathyroid macrophages in golden hamsters
from neonatal to senile periods were investigated using the monoclonal antibody
to ED2 and electron microscopy. The results showed that definite ED2-positive
cells were hardly detectable in the parathyroid gland of 1-day-old hamsters. A
few ED2-positive cells could be identified in the parathyroid gland of 10-day-old
hamsters. The ED2-positive cells were more densely and became conspicuous in 1-,
3-, and 12-month-old hamsters. The number of the cells seems to be increased with
aging. Ultrastructurally, we did not find any macrophages in parathyroid glands
of 1-day-old hamsters. In the 10-day-old hamster parathyroid gland, a few
macrophages existed only in the interstitial tissues. In the parathyroid gland of
1-, 3-, and 12-month-old hamsters, many macrophages were found in the
perivascular regions, some cells located among the parenchymal chief cells with
no obvious vascular association. These cells showed some physical contacts with
chief cells. These results suggest that the parathyroid macrophages exhibit
dramatical changes in their distribution and morphology from neonatal to senile
periods.
PMID- 10693326
TI - An odontometrical difference in the mandibular molars of two laboratory strains
of the musk shrew, Suncus murinus, derived from Bangladesh and Tokunoshima Island
of Japan.
AB - We investigated an odontometrical difference in the mandibular molars (M1, M2,
and M3) of two laboratory strains of the musk shrew (Suncus murinus) originating
in Bangladesh (BAN strain) and Tokunoshima Island of Japan (TKU strain). We used
skulls from two strains of shrews that were maintained under identical laboratory
conditions. Mesiodistal and buccolingual crown diameters in the trigonid and
talonid of the mandibular molars were measured with a measuring microscope,
calibrated to 0.001 mm. The crown proportion was expressed by the crown indices
calculated from the measurements. Size reduction was analyzed quantitatively
according to the reduction index. All crown dimensions were significantly larger
in BAN shrews than in TKU shrews (P < 0.01). Sexual differences were noted in the
talonid dimensions, while interstrain differences were clearly evident in the
trigonid dimensions. The crown indices in M1 showed the least interstrain
difference of the three molars. The crown indices showed that TKU shrews had
relatively larger buccolingual diameters and talonid diameters than BAN shrews,
and the reduction indices showed that TKU shrews had relatively larger M2 and M3
than BAN shrews. To extract the variance components of tooth shape, a principal
component analysis was performed after the variables were standardized. After
Varimax rotation, each factor was interpreted. The first three factors accounted
for 79.9% of all variances. The first component represented the mesiodistal crown
proportion of the trigonid-to-talonid crown component. The second and third
components represented the relative size of buccolingual diameters in the distal
molars for M1. The principal component scores showed that TKU shrews had
relatively larger talonids and distal molars than BAN shrews.
PMID- 10693327
TI - Sexual dimorphism of the human spinal cord in the aging process.
AB - There have been few morphometric studies on age-related changes in the human
spinal cord. The purpose of the present study was to determine the existence of
sexual dimorphism of the spinal cord between males and females during the aging
process. Spinal cords were removed from cadaver specimens, 26 males and 22
females for anatomic practice, the age at death ranged from 41 to 97 years for
males (average, 71.5 years) and from 59 to 92 years for females (average, 76.6
years). Spinal cord segments were embedded in celloidin after secondary fixation
and dehydration. Sections were stained with the Luxol fast blue-periodic acid
Schiff-hematoxylin and Kluver-Barrera methods. Morphometric analysis was
performed with an electronic optical planimeter and a computer. Each section was
enlarged 13.5 times to take a picture. The areas of the transverse section white
matter and gray matter of the spinal cord at segments C5 and L3 were measured.
Although there was no correlation between the total transverse area of the spinal
cord and age either in males or females, we noticed that the area of the gray
matter decreased faster in males than in females; while the area of the white
matter decreased faster in females than in males. The area ratio of the white
matter to the whole segment area of the spinal cord (W/T) at level C5 is larger
in males than that in females. Our results suggest that there could be a
difference between males and females in changes in the white and gray matters of
the spinal cord due to aging.
PMID- 10693328
TI - Morphology of the dorsal lingual papillae in the blackbuck, Antilope cervicapra.
AB - The dorsal lingual surface of a blackbuck (Antilope cervicapra) was examined by
scanning electron microscopy (SEM). The tongue was about 125 mm in length. There
were about 30 vallate papillae on both sides. Filiform, conical, fungiform and
vallate papillae were found. The filiform papillae were distributed over the
entire dorsal surface of the tongue, excepted for the lingual torus where conical
papillae were present. The fugiform papillae were present rounded bodies, and
more densely distributed on the tip and ventral surface of ligual apex. No
foliate papillae were seen on the dorsal surface. The vallate papillae were
located on both sides of the midline in the caudal part. Each papilla was
surrounded by a groove. These findings indicate that the tongue of the blackbuck
is similar to that of the formosan and japanese serow.
PMID- 10693329
TI - The variations of the subclavian artery and its branches.
AB - This study reports important variations in branches of the subclavian artery in a
singular cadaver. The origin of the left vertebral artery was from the aortic
arch. On the right side, no thyrocervical trunk was found. The two branches which
normally originate from the thyrocervical trunk had a different origin. The
transverse cervical artery arose directly from the subclavian artery and
suprascapular artery originated from the internal thoracic artery. This variation
provides a short route for posterior scapular anastomoses. An awareness of this
rare variation is important because this area is used for diagnostic and surgical
procedures.
PMID- 10693330
TI - A radiological method on the classification of human mandibular condyles.
AB - A radiological quantitative method applied in the classification of 210
mandibular condyles from 105 male and female subjects, aged 18-62 with no
temporomandibular disorders has been taken up in this study. Through coronal
sections, types of condyles were first determined by computer tomography (CT) per
anterio-posterior aspects and then divided into four main groups described as
flat, convex, angled and round. Then, using the parameters, every condyle type
was divided into three subgroups. Finally, the percentage of each group has been
estimated as follows: flat, 14.3%; convex, 35.2%; angled, 35.7% and round, 14.8%.
When the condylar type was compared with sex, it was observed that the angled
type (39.6%) in males and the convex type (40.3%) in females were higher than the
other types. In the analysis of the relationship between age and condylar types,
there appeared to be a trend toward an increase in the incidence of flat and a
decrease in the incidence of convex with an increase in the age of males. In
addition, following the determination of bilateral symmetry and asymmetry the
bilateral asymmetry was determined to be higher in both sexes (56.2%).
PMID- 10693331
TI - Variations of nerves located in deep gluteal region.
AB - The relation of the nerves with the piriformis muscle in the deep gluteal region
examined in 50 buttock from 18 male and 7 male newborn cadavers. The nerves were
found in usual position in 74% of sides, while one or more nerves perforated the
piriformis in 16% and, unusual location of the nerves with intact piriformis was
in 10% of sides. Abnormal located nerves are utilised in view of whether
originating from dorsal or ventral part of the sacral plexus.
PMID- 10693332
TI - [Effectiveness and adverse effects of sildenafil in erectile dysfunction].
AB - Sildenafil is a selective and by oral administration potent type-5
phosphodiesterase (PDE 5) inhibitor, which increases the erection by corpus
cavernosum smooth muscle relaxation. In a non-placebo controlled study, 134
patients with erectile dysfunction were treated with oral sildenafil. The aim of
the study was to estimate the efficacy and adverse effects of this treatment. 51
patients (38%) had psychogenic, and 83 (62%) organic origin of the erectile
dysfunction. 73 of them have already had some treatment for this problem before.
The effective dose was 50 mg for 84 patients (63%), 100 mg for 32 (24%) and 25 mg
for 4 patients. The treatment was effective for 120 patients (90%). The most
common adverse effect was flushing in 18 (13%) and headache in 9 (7%) cases, two
patients had headache and flushing together. Nasal congestion and visual
disturbances were complained by two patients. Two patients reported prolonged
(max. 2h) erections. Cardiological investigation was performed for cardiovascular
patients and for patients with risk factors. Exact criteria of the cardiological
opinion of sildenafil treatment are reviewed. Cardial or other serious adverse
effects were not observed. It was not necessary to stop the treatment because of
the adverse effects. The authors found, that sildenafil is an effective and safe
treatment for the erectile dysfunction.
PMID- 10693333
TI - [Dynamic MR examination of the breast--histological correlations].
AB - The authors outline dynamic MR mammography (dMRM) as a highly sensitive
diagnostic method for the examination of the breast. In a retrospective study
relating to 84 processed cases, in the knowledge of the cytological-histological
findings the diagnostic accuracy of the examinations was determined. The role of
the method in detecting benign and malignant changes of the breast has been
estimated. Misdiagnosed cases have been analysed and recommendations for the
application of the method are included. The MR proved to be positive in 32 cases
and negative in 3 cases of the analysed 35 malignant tumors. Benign lesions were
found at microscopy in 49 cases, of which MR correctly diagnosed 40. The
sensitivity and the specificity of dynamic MR mammography were 91% and 82%.
PMID- 10693334
TI - [Neuroendoscopic removal of a colloid cyst of the third ventricle].
AB - The removal of the benign and only slightly symptomatic but by virtue of their
localization potentially fatal lesions is a challenge for the neurosurgeons. Such
cases demand a therapy without any postoperative morbidity. The neuroendoscopy
meets these requirements and proves to be effective in more and more fields of
the art. This article reports a case when colloid cyst was resected entirely by
use of a neuroendoscope, firstly in Hungary.
PMID- 10693335
TI - [Immunomodulation with fumaric acid. Systemic therapy in psoriasis].
AB - The treatment of psoriasis vulgaris with fumaric acid esters has been
controversial for more than 30 years. Recently the fumaric acid derivatives are
marketed antipsoriatics in many European countries. In this paper the clinical
efficacy, the side effects as well as the mode of action of these highly potent
substances are summarized.
PMID- 10693336
TI - [A case of datura stramonium poisoning--general problems of differential
diagnosis].
AB - In past year drug abuse becomes more and more general in Hungary. In addition to
consume traditional drugs, other substances are used frequently too. One of them
is the Datura stramonium, which contains alkaloids (mostly atropine), and can
result in hallucinations. Therefore Datura stramonium is seemingly becoming
popular as a hallucinogenic drug. The consumption of any part of the plant causes
atropine intoxication, thus anticholinergic delirium. Differential diagnosis of
Datura intoxication can be difficult in the everyday medical practise. In our
paper the symptomatology, diagnosis, differential diagnosis, and therapy of
Datura intoxication are discussed and we report one of our cases.
PMID- 10693337
TI - [Changes in the parotid salivary gland of rats with experimental prostatitis].
AB - Experiments on 46 rats showed that infectious and allergic prostatitis led to
development of dystrophic changes in the acinar tissue and ducts of the parotid
glands. The cause of these changes is not clear; a humoral or neuroreflex
relationship of a reactive type is suggested.
PMID- 10693338
TI - [Hereditary pathology of the enamel and dentin. A review of molecular genetic
research].
AB - Mapped phenotype of imperfect amelogenesis, type II imperfect dentinogenesis,
hereditary opalescent dentin, Capdepont's dysplasia, and type II dentin dysplasia
is described for the first time in Russia. Classification of hereditary disorders
in dentin development is presented.
PMID- 10693339
TI - [An enamel adhesion study of Esterfill adhesives with chemical and light
hardening].
AB - The purpose of this work is to define the dependence of adhesive bond strength on
a way of cure of adhesive system, application of the primer and bond in two step
or in one step in vitro. Chemically curing "Esterfill bond" (AB) and both light
curing primer and bond, and composite hybrid light-curing restorative material
"Esterfill PHOTO" (EP) (DIAS LTD, Russia) were used. The shear bond strength was
measured according to recommendation of ISO 11405:1994. The apparatus for these
tests corresponds to ISO 10477, addition I. Shear bond strength was measured on
enamel of 83 extracted human molars. Teeth were divided into 7 groups. Before
using of adhesive system enamel was etched by 37% phosphoric acid during 60 sec.
For measuring of shear bond strength the post composite restorative material "EP"
(dentin) has been used. The received data show that the shear bond strength does
nat depend on the type of cure, the composition of the bonds being similar. Using
primer before application of the bond increases the shear bond strength
approximately by 4-5 MPa. The inclusion of the primer in the content of the bond
system increases the adhesion to enamel by 9 MPa.
PMID- 10693340
TI - [The evaluation of periodontal status by the chemical composition of the oral
media].
AB - Twelve patients aged 21-38 years with gingivitis and periodontitis and 9 subjects
with intact periodontium were examined. Air from the oral cavity was collected
with a special device, liquid samples were collected by gargling with sterile
water. Chemical composition of the air and washings was analyzed by chromato-mass
spectrometry, gas adsorption and gas liquid chromatography. Inflammation of
periodontal tissues was associated with a sharp increase in the oral air
concentration of methylethylketone. The concentrations of isovaleric, n-valeric,
and n-enanthic aldehydes increased appreciably. Ethanol predominated over n-butyl
alcohol. The levels of dimethylsulfide and isoprene increased several times. In
the washings from the oral cavity, the content of microorganism's vital activity
products (fatty acids) was increased. Possible metabolic mechanisms of the
detected shifts are discussed.
PMID- 10693341
TI - [The use of a cyanoacrylate-based composite material in operations on the
alveolar processes of the jaws].
AB - Improvement of methods for preventing inflammatory complications after surgery on
the jaw bones and induction of predictable regeneration of bone tissue at the
site of intervention is an important problem. Numerous experimental and clinical
studies in Russia and abroad demonstrated the efficacy of biodestroyed materials
on the basis of rapidly polymerized monomers--cyanacrylates. The products of
polycyanacrylate biodestruction are nontoxic and are not accumulated in the
organism. Addition of antiseptics and antibiotics in sufficient amounts to
polycyanacrylates prevents the development of inflammatory processes at the site
of the composite application. A new Russian composite material MK-9M was used in
44 patients operated on the alveolar process bone at Department of Oral and
Maxillofacial Surgery of Moscow Medical Stomatological Institute in 1997-1998.
Pronounced anti-inflammatory and osteoregenerating effect was attained in all
cases.
PMID- 10693342
TI - [The presentation of relative values in scientific research results].
PMID- 10693343
TI - [The pathogenesis of posttraumatic deformities of the mandible in the growing
organism].
AB - Experiments on developing animals showed that mandibular fractures of any
location can be complicated by pronounced growth disorders and abnormal
development of mandibular bone, leading to deformations of the site of fracture.
Abnormal mandibular development was particularly obvious after injuries to the
condyle and condylar process, after fractures of mandibular body and angle with
dissection of the neurovascular bundle, and in cases with osteomyelitis.
Disorders in endochondral bone formation (which is normally most active in the
condyle) caused by traumatic processes and disorders in neurotrophic regulation
and blood supply to the bone, developing in neurovascular obstruction, underlie
the mechanisms of posttraumatic mandibular deformations. These complications were
observed in patients with fractures of different sites because of improper
joining and fixation of fragments. Children should be regularly checked up after
mandibular fractures. Measures aimed at prevention of growth disorders and
development of mandibular bone lesions are obligatory at all stages of
examination.
PMID- 10693344
TI - [The clinical x-ray aspects of the diagnosis and treatment of the
temporomandibular joint pain dysfunction syndrome].
AB - Clinical and x-ray picture of the syndrome of painful dysfunction of the
temporomandibular joint is described. Differential diagnosis of this syndrome and
other articular diseases with similar clinical symptoms is presented. Treatment
strategy is described in brief.
PMID- 10693345
TI - [The clinico-microbiological evaluation of the efficacy of using new drug forms
of chlorhexidine--Corsodyl and Eludril--for the prevention of infectious
complications in operations for endosseous implantation].
AB - Prevention of infectious inflammatory complications of intraosseous implantation
is a pressing problem. Chlorohexidine dosage forms Corsodyl and Eludril were used
for this purpose. In the control group, furacillin was used. Microbiological
studies showed that instillations of Corsodyl and Eludril solutions during the
postoperative period did not modify normal oral microflora and led to
disappearance of the most aggressive anaerobic bacteria in 1-3 days. These drugs
are more effective that Listerine, and they are recommended for prevention of
infectious inflammatory complications after intraosseous implantation.
PMID- 10693346
TI - [The clinical picture, diagnosis and radiation treatment principles in cancer of
the buccal mucosa].
AB - Diagnosis and treatment of 228 patients with cancer of the buccal mucosa is
analyzed. There were 130 women and 98 men aged 65 years on average. 218 were
primary patients and 10 with relapses. Squamous-cell carcinomas with
hornification predominated: 217 cases (95%). Adenocarcinoma was diagnosed in 8
(3.5%) and poorly differentiated cancer in 3 patients. Metastases to the regional
lymph nodes were detected in 25% cases. For cosmetic reasons, radiotherapy (oral
x-ray therapy, interstitial method, long-distance gamma beam therapy) was the
method of choice.
PMID- 10693347
TI - [The use of computer technologies in rehabilitative and reconstructive surgery on
the facial supporting tissues].
PMID- 10693348
TI - [The x-ray stereometric assessment of mandibular asymmetries].
AB - The method of spatial appreciation of mandibular structure on the basis of
straight and lateral cephalogram is proposed. Asymmetry is appraised by
comparison of its right and left side. The analysis is based on linear and corner
sizes. Possibilities and perspectives of present line of research are outlined.
PMID- 10693349
TI - [Endoscopic technologies in maxillofacial surgery].
AB - Endoscopic operations in 107 patients with numerous maxillofacial diseases are
analyzed. Endoscopic technologies were used in diseases of the maxillary sinus,
temporomandibular joint, injuries to the facial nerve, and cysts of the jaws. New
methods for surgical treatment of mandibular fractures, zygomatico-orbital
complex, cysts of the jaws are proposed. The results of utilization of endoscopic
technologies in maxillofacial surgery are analyzed and their high efficacy and
good prospects are demonstrated.
PMID- 10693350
TI - [Impaired occlusion is the main etiological factor in the occurrence of
temporomandibular joint dysfunction].
AB - A homogeneous group of 104 subjects aged 21-34 years was examined. Forty-nine
(47%) subjects (study group) presented with symptoms of abnormalities of the
masticatory muscles and temporomandibular joint, 58 subjects (53%) without such
symptoms were controls. Clinical examination was carried out with evaluation of
occlusion, Angle's [correction of Engle's] class, and analysis of dental contacts
in the oral cavity in different types of occlusion. Disorders of occlusion were
detected in 31% of controls and in 73% patients in the study group. Disorders of
occlusion correlated with the number of symptoms of temporomandibular joint
dysfunction. The detected super-contacts of teeth are the main etiological
factors leading first to discoordination of the masticatory muscles and then to
functional disorders of the temporomandibular joint.
PMID- 10693351
TI - [The dynamics of the colonization by the microbial flora of the mouth of the
different materials used for dental prosthetics].
AB - Colonization of materials used for making dentures with oral microflora was
studied in 12 patients with chronic generalized medium severe periodontitis
during remission. Time course of dentures colonization with representatives of
oral microflora (S. sanguis, Peptostreptococcus sp., Prevotella oralis) and with
bacteria pathogenic for the periodontium (Prevotella melaninogenica, A.
naeslundii, Fusobacterium sp.) depends on the material from which the dentures
are made. Minimal colonization of bacteria pathogenic for the periodontium was
observed on cermet dentures.
PMID- 10693352
TI - [The classification of congenital clefts and defects of the palate after
uranoplasty. The clinico-embryo-pathogenetic principles].
AB - The authors suggest classifying palatal clefts as an individual nosological
entity resultant from impaired differentiation, growth, and fusion of primary
embryonal structures forming the palate as an anatomical structure. Definition of
the palatal interface on the basis of the embryo-pathogenetic principle underlies
the working classification of palatal defects developing after uranoplasty.
PMID- 10693353
TI - [Reconstruction of the hard palate in congenital clefts].
AB - Cleft palate advancement is linked with the new bone regeneration after palate
and alveolar process osteotomy and underdeveloped palatal process of the jaw
moving to a normal anatomy position.
PMID- 10693354
TI - [The expert evaluation of dental institutions during their licensing and
accreditation].
PMID- 10693355
TI - [The evolution of the concepts on the causes of the occurrence of dental caries].
PMID- 10693356
TI - [The 50th anniversary of the awarding of the State Prize in the Field of Medicine
to A. A. Limberg].
PMID- 10693357
TI - [Prof. B. M. Pashkov--the founder of the dermatostomatological direction in the
solution of the scientific problems of dentistry (on the centenary of his
birth)].
PMID- 10693358
TI - Hepatitis A vaccines.
PMID- 10693359
TI - Who pays the bill and who makes the profit in treating chronic disease?
PMID- 10693360
TI - Who should care for people with chronic diseases?
PMID- 10693361
TI - The epidemic of obesity.
PMID- 10693362
TI - Compensation awarded for death after illegible prescription.
PMID- 10693363
TI - HMO sues charity over domain name.
PMID- 10693364
TI - Ask patients which herbal drugs they smoke as well as eat.
PMID- 10693365
TI - Clinicians in private practice give generously in teaching time.
PMID- 10693366
TI - A cutaneous manifestation of a systemic disease.
PMID- 10693367
TI - Case-control study of 10 years of comprehensive diabetes care.
AB - OBJECTIVE: To describe the long-term clinical impact of a comprehensive
management program instituted throughout a health system for members with
diabetes mellitus. DESIGN: 10 year case-control evaluation. SETTING: Kaiser
Permanente Northwest, Portland, OR. PARTICIPANTS: Members of the health
maintenance organization between 1987 and 1996; members with diabetes were
compared with equal numbers of members without diabetes. The number of
participants with diabetes ranged from 5331 in 1987 to 13,099 in 1996. MAIN
OUTCOME MEASURES: Number in diabetes register, mortality, change in comorbidity,
rates of uptake of preventive health measures, use of pharmaceuticals, levels of
risk factors, hospital days per thousand per year, emergency room visits per
thousand per year. RESULTS: The prevalence of diabetes identified in this
population rose from 2.54% (7,895/310,819) in 1987 to 3.66% (14,741/402,754) in
1996, and the mean (SEM) age of members at the time of diagnosis fell slightly
from 62.9 (+/- 0.21) years to 62.0 (+/- 0.13) years (P < 0.05). By 1996, 10,885
of the 13,099 (83% +/- 0.3%) of members with diabetes had an annual laboratory
test to assess glycemic control, the annual screening rate for retinopathy was
67.6% (+/- 0.4%), the rate of uptake of influenza immunizations was 60.2%
(7,886/13,099) and the screening rate for nephropathy was 43% (5,698/13,099) (+/-
0.49%). The use of home glucose testing increased from 32.4% (1721/5331) of
members with diabetes to 53.0% (6,942/12,099); the use of lipid lowering drugs
increased from 3.5% (187/55,331) to 19.8% (2,594/13,099). The use of angiotensin
converting enzyme inhibitors increased from 8.5% to 34.8% of members with
diabetes. Mean blood pressure decreased from 144/82 mm Hg (+/- 0.8/0.4) to 138/79
mm Hg (+/- 0.3/0.15), and mean total cholesterol concentrations dropped from 243
mg/dL (+/- 4.2) to 215 mg/dL (+/- 0.6). By 1996, 56.4% (7,388/1,3099) (+/- 0.5%)
of members on the diabetes register had good to excellent glycemic control (HbA1c
< 8%). Mortality decreased from 4.8% (256/5331) (+/- 0.3%) to 3.6% (472/13,099)
(+/- 0.2%) among members with diabetes, this was a more rapid decrease than was
observed among those without diabetes (P < 0.01). The annual ratio of visits to
the emergency room by members with diabetes to members without fell from 2.5 to
1.8, and the ratio for the number of days spent in acute care in the hospital
dropped from 3.6 to 2.5. CONCLUSIONS: This centrally organized program based in a
primary care setting and utilizing a register of patients with diabetes was
associated with substantial improvements in the process and outcomes of care in a
large population of health maintenance organization members with diabetes.
PMID- 10693368
TI - Randomized, controlled trial of glucosamine for treating osteoarthritis of the
knee.
AB - OBJECTIVE: To determine the effectiveness of glucosamine in reducing pain from
osteoarthritis of the knee. DESIGN: Randomized, double-blind parallel trial of
glucosamine 500 mg three times daily or a placebo for 2 months. SETTING: Veterans
Affairs Medical Center, Prescott, AZ. PARTICIPANTS: Ninety-eight patients aged 34
to 81 being treated for osteoarthritis of the knee. MAIN OUTCOME MEASURES: Pain
intensity both at rest and while walking as assessed by a visual analog scale at
baseline and after 30 and 60 days of treatment. RESULTS: Forty-nine patients were
randomly allocated to each group. There was no statistical difference between the
two groups in scores on the visual analog scale at 30 days for resting (mean [SD]
score placebo group 3.5 [2.7] vs 3.3 [2.4] glucosamine group, P = 0.66) or
walking (5.1 [2.6] vs 5.3 [2.4], P = 0.69); there was also no difference at 60
days for resting (3.4 [2.5] vs 3.2 [2.5], P = 0.81) or walking (4.9 [2.2] vs 4.9
[2.8], P = 0.90). There was also no statistical difference between groups in the
mean change from baseline in scores on the visual analog scale (mean [SD] change
for walking at 60 days placebo group -1.5 [2.5] vs glucosamine group -1.4 [3.0],
P = 0.77). Two participants taking glucosamine and 4 taking placebo withdrew from
the study due to adverse side effects (P = 0.67). CONCLUSION: Glucosamine was no
better than placebo in reducing pain from osteoarthritis of the knee in this
group of patients.
PMID- 10693369
TI - Use of alternative products: where's the beef?
PMID- 10693370
TI - Magnesium sulfate is effective for severe acute asthma treated in the emergency
department.
PMID- 10693371
TI - Ovarian cancer screening was feasible but did not decrease incidence of index
cancer or mortality.
PMID- 10693372
TI - How medications affect thyroid function.
PMID- 10693373
TI - Use of opioids to treat chronic, noncancer pain.
PMID- 10693374
TI - Update on Alzheimer's disease: recent findings and treatments.
PMID- 10693375
TI - Chronic back pain: does bed rest help?
PMID- 10693376
TI - Emotional dimensions of chronic disease.
PMID- 10693377
TI - How to deal with medically unknown symptoms.
PMID- 10693378
TI - When AIDS became a chronic disease.
PMID- 10693379
TI - Individualized stepped care of chronic illness.
PMID- 10693380
TI - Speaker's corner. Living with thalassemia.
PMID- 10693381
TI - In favour of tolerance.
PMID- 10693382
TI - Hyperventilation and the body.
AB - Hyperventilation has rapid and far-ranging physiological effects via its
alteration of pH and depletion of CO2 in the body, resulting in respiratory
alkalosis, acute or chronic. The general effects on skeletal and smooth muscles,
as well as neural tissue, are summarized. A wide variety of symptoms such as
pain, tension, disturbances of consciousness, circulatory problems and
cardiovascular effects can confound treatment efforts but may respond to
alterations of breathing patterns. Suggestions are given for detecting this
condition.
PMID- 10693383
TI - It's a disaster: emergency departments' preparation for a chemical incident or
disaster.
AB - Nurses in the Accident & Emergency (A&E) Department have a significant role to
play in the treatment and resuscitation of victims of a chemical disaster.
Chemical disasters are unique because casualties are contaminated. Nursing staff
triage casualties and they have direct contact with contaminated patients, before
and during decontamination. Consequently they require adequate personal
protective equipment and information regarding isolation and decontamination. The
use of chemicals has increased since the turn of the century. Hazardous chemical
emergencies arise from accidents in production, storage, transportation and the
disposal of chemical substances. Their illegal manufacture and use by terrorists
makes the likelihood of a chemical disaster with mass casualties in Australia
very real. Emergency departments are ill-prepared to deal with this scenario, and
very few disaster plans include a comprehensive decontamination component. To
achieve an effective response with the best utilisation of resources, it is vital
for emergency services personnel and A&E departments to be prepared.
PMID- 10693384
TI - Fundamental issues in questionnaire design.
AB - The questionnaire is probably the most common form of data collection tool used
in nursing research. There is a misconception that anyone with a clear grasp of
English and a modicum of common sense can design an effective questionnaire.
Contrary to such common belief, this article will demonstrate that questionnaire
design is a complex and time consuming process, but a necessary labour to ensure
valid and reliable data is collected. In addition, meticulous construction is
more likely to yield data that can be utilized in the pursuit of objective,
quantitative and generalizable truths, upon which practice and policy decisions
can be formulated. This article examines a myriad of fundamental issues
surrounding questionnaire design, which encompass question wording, question
order, presentation, administration and data collection, amongst other issues.
PMID- 10693385
TI - Responding to autonomy and disempowerment at the time of a sudden death.
AB - This paper examines the difficulty of giving people choices and recognising their
autonomy at the time of a sudden death. It discusses how they achieve this whilst
disempowered and frightened.
PMID- 10693386
TI - Increasing patient numbers: the implications for New Zealand emergency
departments.
AB - Within the New Zealand (NZ) health care system, a number of changes have affected
the way health care is accessed and delivered. Emergency Departments (EDs) are
noticing increased attendance of patients with minor or non-urgent conditions.
This increase in patient volume, together with on-going fiscal constraints and
restructuring, has placed an added strain on the functioning of EDs. New Zealand
nurses need to question the role currently given to EDs and identify the issues
surrounding the increased use of these departments for primary health care. Is
this move feasible in the NZ environment, and what are the implications for
emergency nurses?
PMID- 10693387
TI - Accident prevention in the A&E department.
AB - Accident and Emergency units are often regarded as the 'shop window' of a health
service. While the priority is to attend to those in need of emergency services,
there may also be opportunities for health education amongst a 'captive
audience', particularly in relation to accident prevention. This report
illustrates how the influence of one A&E department was used amongst primary
school children to increase their awareness of cycle safety. Educational
materials were developed, a series of visits to schools was planned, which over
600 children attended, and a competition organised. Initial responses from the
children were very positive, and an analysis of subsequent cycle injury levels is
now under way. The project formed part of a wide ranging practice development
programme within a large district general hospital in Whitehaven in collaboration
with St Martin's College Department of Nursing. It combined the need to develop
quality services and staff in tandem. The outreach educational approach is now
being examined for adoption in other areas of the Trust.
PMID- 10693388
TI - Reflective narrative: Autonomous Practitioner course.
PMID- 10693389
TI - Farewell to A&E.
AB - Carolyn Stead's moving account of the sudden death of her baby son Dominic was
published in the January 1998 issue. It is reprinted on pages 170-174, before
this update, in which Carolyn outlines her subsequent experiences and emotions.
PMID- 10693390
TI - A classical dilemma.
PMID- 10693391
TI - Valuing nurse practitioners.
PMID- 10693392
TI - The faculty of emergency nursing. A personal view.
PMID- 10693393
TI - The 'millennium bug'. Its effect on the workplace and what is being done about
it.
PMID- 10693394
TI - Antifreeze poisoning.
PMID- 10693395
TI - Inhalation injuries.
PMID- 10693396
TI - Autonomous practitioner or handmaiden?
PMID- 10693397
TI - Training users of telemedicine.
PMID- 10693398
TI - Managing managed care: the next level for transcultural nurses.
PMID- 10693399
TI - Transcultural nursing and community-based care.
PMID- 10693400
TI - Voices of transcultural nursing.
PMID- 10693401
TI - From a practice perspective.
PMID- 10693402
TI - Response to the commentaries on defining transcultural nursing.
PMID- 10693403
TI - Nursing and anthropology: two worlds to blend.
PMID- 10693404
TI - Global perspectives in nursing and health.
PMID- 10693405
TI - Health promotion in cervical cancer prevention among the Yakama Indian women of
the Wa'Shat Longhouse.
AB - The purpose of this 3-year study was to gain a greater understanding of the
importance of the Wa'Shat Longhouse religion to the design of a culturally
appropriate health promotion (cervical cancer prevention) program with the Yakama
Indian people of eastern Washington. This descriptive study involved interviews
with 10 Wa'Shat members, observations, and participant observations of 30
community ceremonial activities. The framework of health promotion planning
guided the investigation. We found that (a) program goals needed to be holistic
and wellness oriented, (b) teaching methods needed to include circular symbols,
and (c) intervention strategies needed to be linked to the natural patterns of
communication of the Wa'Shat Longhouse and to involve elders. Storytelling,
talking circles, and use of role models were all found to be important teaching
methods. We confirm previous perspectives on the importance of religion, provide
greater depth in this understanding and outline implications for transcultural
nursing practice.
PMID- 10693406
TI - Transcultural nursing with Native Americans: critical knowledge, skills, and
attitudes.
AB - Native American nurses are in an ideal position to articulate how to serve Native
people in ways that respect indigenous cultures. Forty Native American nurses and
nursing students completed a survey on knowledge, skills, and attitudes/values
necessary for culturally competent service provision to Native patients. Four
knowledge themes, four skill themes, and three attitude/value themes were
identified. Nurses must know about and show respect for the culture and history
of Native groups, including culturally specific health beliefs and healing
practices. Skills must be tailored for work in a non-Western context, and
containment skills become particularly important. Additionally, respecting
diversity and traditions and being open-minded and nonethnocentric are
fundamental. This study provides valuable information nurses can use to enhance
their work with indigenous people.
PMID- 10693407
TI - Mexican American women's expressions of the meaning of culturally congruent
prenatal care.
AB - The purpose of this study was to describe, explicate, and systematically analyze
the meanings, expressions, and experiences of generic and professional care
during pregnancy of Mexican American women in their home and prenatal clinic
contexts. The ethnonursing method was used to describe cultural care among 16 key
and 34 general informants. Generic culture care was valued and considered
essential by informants for healthy childbearing. Six major themes were
synthesized from 30 cultural patterns: (a) generic culture care included the
protection of the mother and fetus by older Mexican American women and was
greatly influenced by religion and family beliefs and practices; (b) generic
culture care was family obligation for provision of filial (family) succorance,
sharing of self, and being with the childbearing mother; (c) culture care was
respect for familial caring roles in relation to age and gender; (d) childbearing
Mexican American women viewed culture care by professional nurses as concern for,
professional knowledge, protection, being attentive to, and explaining; (e)
culture care was use of the Spanish language in caring interactions in diverse
environmental contexts; and (f) professional prenatal care was valued by Mexican
American women and was influenced by legal, economic, and technological factors
in the social structure.
PMID- 10693408
TI - Intergenerational analysis of dietary practices and health perceptions of
Hispanic women and their adult daughters.
AB - This descriptive, correlational, two-group study investigated differences between
dietary practices, acculturation, and health perceptions in a convenience sample
of Hispanic mothers and their adult daughters (N = 76, 47 mother-daughter dyads).
Analysis (paired t tests) of the Block Screening Questionnaire, General
Acculturation Index, and Self-Rated Health Subindex of the Multilevel Assessment
Instrument showed significant differences: Daughters ate more fat (p = .04) and
were more acculturated than their mothers (p = .0001). The Pearson correlation
yielded a significant relationship for the 76 subjects between fat intake
(dietary practice) and health perception: The more fat (meat/snacks) intake, the
more negatively women perceived their health status (p = .0001).
PMID- 10693409
TI - A grounded theory study of the experience of type 2 diabetes mellitus in First
Nations adults in Canada.
AB - Diabetes among First Nations peoples has reached epidemic proportions, and
diabetes prevalence, complications, and mortality rates are higher than in
Whites. The purpose of this grounded theory study was to investigate the
experience of Type 2 diabetes in First Nations adults. Ten individuals living in
one reserve community, in southwestern Ontario, participated in this research.
Participants were interviewed on two occasions by a First Nations nurse. All
interviews were audiotaped and transcribed verbatim. A three-phase process of
integration emerged, similar to the process of integration discovered in prior
research with Type 1 diabetic Whites. However, there were some important
differences in the characteristics of these three phases. In addition, there were
surprising findings related to beliefs about the type of diabetes educator
desired by these First Nations clients.
PMID- 10693410
TI - Beliefs about childhood immunisation among Lebanese Muslim immigrants in
Australia.
AB - The aim of the study was to describe and analyse care values, beliefs, and
practices relating to immunisation by Lebanese Muslim immigrants in New South
Wales (NSW), Australia. This ethnonursing study explored the importance of care
related to immunisation, knowledge of informants relating to vaccines, diseases,
side effects, and contraindications. Family responsibilities relating to
immunisation care services as well as expectations and evaluations of care
services provided were also examined. Data were collected via observation
participation-reflection, including in-depth interviews. The findings revealed
significant care themes for Lebanese Muslim informants based on their cultural
values, beliefs, and practices related to health and immunisation. Culturally
congruent nursing care practices related to immunisation for Lebanese Muslims in
NSW, Australia, were identified.
PMID- 10693411
TI - From nurse to nurse anesthetist: the relationship of culture, race, and ethnicity
to professional socialization and career commitment of advanced practice nurses.
AB - The purpose of this study was to identify the relationship of culture, race, and
ethnicity on professional socialization and career commitment of student
registered nurse anesthetists. A 78-item, self-administered questionnaire was
mailed to the United States population of student nurse anesthetists (N = 2,008)
yielding a 56% response. Demographic data and the dimensions of socialization
were analyzed with chi-square and weighted least-squares linear analysis of
variance. Four scales assessed the relationship of age, gender,
culture/race/ethnicity, and views of culturally congruent care on the
socialization process. In all dimensions of socialization, culture and
race/ethnicity both correlated significantly (p < .05) for all nondominant groups
compared to the dominant European American White group. Responses from Asian
Pacific Islanders were most positively correlated to all dimensions of
socialization. Hispanics responded least positively to a life-time commitment to
the career in nurse anesthesia by culture (p = .003) and ethnicity (p = .009).
PMID- 10693412
TI - Interpreters: a double-edged sword in nursing practice.
AB - The provision of health services for all Australians is based on equality of
access to health care services, regardless of cultural origin or linguistic
skill, and on the responsibility of the health system to respond appropriately.
Lack of fluency in the English language and lack of bilingual or multilingual
nurses are major sources of miscommunication, even with the use of interpreters
and translated health information. Many immigrant women find the use of
interpreters unacceptable. Nurses are concerned with legal issues. These two
viewpoints make the use of interpreters a double-edged sword in practice. The
findings of recent research and the literature in relation to language skills and
the use of interpreters and translations in the Australian context are explored.
Potential resolutions for transcultural nursing practice are provided.
PMID- 10693413
TI - Founder's focus--faculty limit students' study of transcultural nursing: a
critical issue.
PMID- 10693414
TI - Pain as the fifth vital sign: will cultural variations be considered?
PMID- 10693415
TI - Transcultural nursing's role in a managed care environment.
PMID- 10693416
TI - Culturally competent managed health care: a family physician's perspective.
PMID- 10693417
TI - A framework for providing culturally competent health care services in managed
care organizations.
PMID- 10693418
TI - Managed care: a turning point for nursing.
PMID- 10693419
TI - Let us try to keep culturally competent care in managed care.
PMID- 10693420
TI - Managed care: pitfalls for cultural bias.
PMID- 10693421
TI - The personal experience of pregnancy for African-American women.
AB - This study describes the personal experiences of pregnancy for African-American
women. Data were obtained from two group interviews with four African-American
nurse-midwives who had experienced pregnancy and had extensive professional
experience in the provision of health care services to pregnant African
Americans. Three major themes were constructed from the interview narratives. The
first concerned the experience of pregnancy as a transition experience from
childhood to adulthood and from womanhood to motherhood, involving heightened
senses of maturity, self-esteem, and intimacy. The second identified stresses
experienced by African-American women, including the lack of material resources
and emotional support. The last theme concerned the provision of effective
support in pregnancy. The significance of interpersonal relationships with the
pregnant women's mothers, other significant women, and their partners was
described. Implications for practice included suggestions for the provision of
effective emotional support from health care professionals such as attentive
listening and the elimination of environmental factors that communicate lowered
personal value.
PMID- 10693422
TI - Developing an instrument to study the tuberculosis screening behaviors of Mexican
migrant farmworkers.
AB - This article details the use of qualitative data in the construction of a Spanish
language, quantitative research instrument designed for a study of Mexican
migrant farmworkers' participation in tuberculosis screening. In the qualitative
study, 19 Mexican migrant farmworkers were interviewed in Spanish to elicit their
explanatory models (EMs) about tuberculosis. The Tuberculosis Interview
Instrument (TII) was developed from the results of the qualitative study and
concepts from a theoretical framework consisting of a combination of the Health
Belief Model (HBM) and the Theory of Reasoned Action (TRA). After its
development, the TII was subjected to translation and back-translation procedures
to insure the equivalency of the English and Spanish versions, and it was
reviewed for content validity. Internal consistency reliability, based on the
responses of 206 subjects, was satisfactory for all subscales. Future testing of
the TII is recommended to evaluate its stability among Mexican migrant
farmworkers in other parts of the United States.
PMID- 10693423
TI - The health care meanings, values, and practices of Anglo-American males in the
rural midwest.
AB - Limited nursing knowledge exists to explain how culture influences men's health
care decisions and practices. The purpose of this collaborative research was to
explore the health care meanings, values, expressions, lived experiences, and
practices of Anglo-American adult males residing in the rural Midwest. Using the
ethnonursing research method, data were collected through interviews with 7 key
and 12 general informants residing in Iowa. Four culture values and five themes
were supported by the findings. Leininger's culture care modes were used to
explicate culturally meaningful nursing care actions and decisions that are in
harmony with the cultural values and practices of rural men.
PMID- 10693424
TI - Panamanians' practices for health promotion and the meaning of respect afforded
them by health care providers.
AB - This study describes and compares Panamanians' and Panamanian Americans'
practices for health promotion and wellness, disease and illness prevention, and
the meaning of respect afforded them by health care providers. Understanding a
person's beliefs and values when planning nursing and health care interventions
helps the caregiver provide culturally acceptable care that improves clients'
satisfaction and health status. Culturally respectful, acceptable, and
appropriate care conserves the utilization of human, material, and financial
resources. This sample comprised 70 subjects: 50 in the Republic of Panama and 20
from the DelMarVa Peninsula in the United States. This study uses selected
primary and secondary characteristics of culture and selected domains from the
Purnell Model for Cultural Competence as guides for questionnaire development,
data analysis, and discussion of the findings.
PMID- 10693425
TI - Disseminating the results of participant-focused research.
AB - Participant-focused research (PFR) includes the "subjects" as full partners in
the research process. As such, participants share in the products or outcomes of
research. PFR goes beyond the traditional research approach of disseminating
findings to other scientists and clinicians and includes participants and
community residents in sharing the skills, knowledge, and resources of the study
with the objective of empowering the participants. This article demonstrates the
use of PFR in disseminating the results or products of study to the participants
through two examples of long-term research projects conducted in Los Angeles. The
first example is a community-based study of HIV prevention with low-income Latina
women. The second example is an ethnographic study of health concerns and risks
among adolescents in juvenile detention. These examples provide two approaches to
dissemination of research findings and benefits to the participants and the
community.
PMID- 10693426
TI - The culture of the deaf.
AB - The population of the United States includes over 1 million deaf people, the
majority of whom have chosen to differentiate themselves in terms of a Deaf
culture. These Deaf people share unique values and norms and use sign language
for communication. The differences that exist between hearing and Deaf
individuals necessitate that the nurse understand this population. This article
will describe the Deaf culture using Leininger's Sunrise Model and present
specific nursing actions in the modes of culture care preservation and/or
maintenance, accommodation and/or negotiation, and repatterning or restructuring
that enable the nurse to provide culturally congruent care for Deaf clients.
PMID- 10693427
TI - People with disabilities--the same, but different: implications for health care
practice.
AB - Despite the author's experiences as a nurse and parent of a young adult with
physical disabilities, the author had much to learn about the culture surrounding
disability. The contemporary "minority-group" model for disability replaces a
medical model that views people with disabilities in need of remediation.
Disability rights advocates often criticize health professionals, citing
erroneous assumptions and failure to understand the perspectives of disabled
persons. The author illustrates applications for clinical practice by health
professionals with excerpts from a qualitative study that explored the spiritual
experiences of adults with physical disabilities and family members as well as
their responses to lived experience with disability.
PMID- 10693428
TI - [Living worlds of children with special need for support between institutions and
daily integrated assistance].
PMID- 10693429
TI - [Screening of newborns--meaningful management].
PMID- 10693430
TI - [Engagement of an outsider at the therapeutic education center Hochbend in
Tonisvorst--report of a student's practical training in the pediatric nursing
school at the Krefeld Hospital].
PMID- 10693431
TI - [Gentle care of prematures--their care in the premature unit].
PMID- 10693432
TI - [Evaluation of pediatric nursing education based on a modified "Oelke
curriculum"].
PMID- 10693433
TI - [Engagement instead of heroism. Delegates to the German Federation of Pediatric
Nurses--persons, scope of activities, range. Project--Part 2: Structure of
delegation].
PMID- 10693435
TI - [Letters on the topic: Babies, lopsided and crookes in the carrying cloth, in
"Kinderkrankenschwester", from 8/99, page 336]
PMID- 10693434
TI - [Professor Hellbrugge on his 80. birthday (10/23)].
PMID- 10693436
TI - [How long to use antibiotics therapy in acute otitis media?].
PMID- 10693438
TI - [The ideal mother].
PMID- 10693439
TI - [Understanding, phenomenologic-biographical diagnosis--an alternative to
traditional classification and diagnostic systems in nursing?].
PMID- 10693437
TI - [Viruses in otitis media].
PMID- 10693440
TI - [Care after a drowning accident].
PMID- 10693441
TI - [The ideal children's hospital. Children's Hospital-Image and Benchmarking study
Germany ].
PMID- 10693442
TI - [20 years of ambulatory pediatric care in Germany--development and current
situation].
PMID- 10693443
TI - [Self-induced illnesses: the Munchhausen syndrome].
PMID- 10693444
TI - [The counter-reformation].
PMID- 10693445
TI - [The pediatric hospital of the Erlangen-Nurnberg University presents its nursing
targets].
PMID- 10693446
TI - [Why healthy sleep is so important. Report from the 7. German Congress for Sleep
Research and Sleep Medicine in Dresden].
PMID- 10693447
TI - [Well taken care of].
PMID- 10693448
TI - [Perioperative therapy problems. Alcoholics in operative medicine--with special
regard to the preoperative alcohol withdrawal syndrome].
PMID- 10693449
TI - [Patients as customers].
PMID- 10693450
TI - [Highest quality, yet lower costs].
PMID- 10693451
TI - ["A dive into cold water". Civil servants in nursing and caring].
PMID- 10693452
TI - [Alzheimer's disease].
PMID- 10693454
TI - [Kidney failure and therapeutic possibilities].
PMID- 10693453
TI - [Baxter Healthcare is starting HomeChoice PRO].
PMID- 10693455
TI - [The first. enteral nutrition, especially designed for the elderly is presented
at the Reha in Dusseldorf].
PMID- 10693456
TI - [Glass, the stuff from which bottles are made].
PMID- 10693457
TI - [OptiPen Pro--more safety for Insulin injections].
PMID- 10693458
TI - [Development of a profession. The hypertension nurse].
PMID- 10693459
TI - [House-dust allergy: many recommendations are helping industry, not the
patients].
PMID- 10693460
TI - [Shaken by fate--but I won't give in].
PMID- 10693461
TI - [Growing impotence]
PMID- 10693462
TI - [Founding of the research group "Monastery Medicine". Mediator between historical
healing and modern medicine].
PMID- 10693464
TI - [Legal aspects of palliative care].
PMID- 10693463
TI - [Palliative medicine. The Dutch euthanasia model has failed].
PMID- 10693465
TI - [Special features in diagnosis and therapy of pulmonary diseases in the aged].
PMID- 10693466
TI - [Strict indications for transurethral indwelling bladder catheters in general
surgery].
PMID- 10693467
TI - [Hepatitis C more dangerous than AIDS. At last a breakthrough in therapy using
the new combination treatment].
PMID- 10693468
TI - [Viruses].
PMID- 10693469
TI - [New: Biatain foam dressings--for wounds with copious exudate].
PMID- 10693470
TI - [Hodgkin's disease: light in the darkness].
PMID- 10693471
TI - [Preservation of life--from inclination or obligation?] [In Process Citation]
PMID- 10693472
TI - [When do I need psychotherapy?].
PMID- 10693473
TI - Notes from England.
PMID- 10693474
TI - Beyond Pierre Robin sequence.
AB - The label Pierre Robin sequence is given to infants presenting with a triad of
specific congenital anomalies: micrognathia, glossoptosis, and cleft palate.
However, this label should be considered the first, not the final, step in the
diagnostic process. In approximately 80 percent of newborns with Pierre Robin
sequence, the triad of anomalies is part of an underlying genetic condition. This
article reviews the variable etiologies of and general clinical considerations
for Pierre Robin sequence. To illustrate how clinical management might vary based
on the identification of an underlying condition, three case examples of neonates
with Pierre Robin sequence and different underlying genetic conditions are
presented.
PMID- 10693475
TI - Adrenal insufficiency in the term and preterm neonate.
AB - The adrenal gland is part of the endocrine system and produces hormones that are
essential for survival. The adrenal cortex, the largest part of the adrenal
gland, produces three major hormones. Glucocorticoids regulate metabolism of
glucose, protein, and fat and allow the body to respond to stress by increasing
blood glucose levels and cardiac output. Mineralocorticoids regulate fluid and
electrolyte balance and help maintain blood pressure. Androgens are responsible
for sexual differentiation in the fetus. Insufficient production of these
hormones can occur for many reasons and can have a profound effect on the
newborn. It is important for neonatal nurses to be familiar with signs and
symptoms and appropriate treatment of adrenal insufficiency. This article
explores causes, signs and symptoms, and treatment of adrenal insufficiency in
the newborn.
PMID- 10693476
TI - Back to sleep: is there room in that crib for both AAP recommendations and
developmentally supportive care?
AB - This article offers one institution's approach to implementation of the
recommendations for infant sleep positioning as set forth by the American Academy
of Pediatrics. The guidelines are directed toward healthy infants in the first
year of life, a population not always encountered by the neonatal nurse. The
guidelines focus on supine sleep position and the minimization of additional
bedding, both of which can be challenging when contrasted with accomplishing
supportive positioning and the goals of developmentally supportive care for ill
or preterm infants. A multidisciplinary task force was formed to consider this
challenge. The outcome is an evidence-based policy that is presented as an
example for other clinicians. The policy addresses the following major
components: sleep position with specific clinical exceptions, the use of bedding
materials, play position during awake states, and parent education with
preparation for discharge. The article also outlines the process by which the
task force plans to implement and evaluate necessary practice changes.
PMID- 10693477
TI - Suspended mothering: women's experiences mothering an infant with a genetic
anomaly identified at birth.
AB - PURPOSE: To develop an understanding of the experiences of women who give birth
to an infant with a genetic anomaly not identified during the prenatal period.
DESIGN: Exploratory design using selected qualitative methods. SAMPLE: Seven
mothers of liveborn infants with a genetic anomaly characterized by physical
attributes evident at birth. MAIN OUTCOME VARIABLE: Mother's expressions of
suspended mothering. RESULTS: Two themes emerged that characterize the experience
of suspended mothering: diminished maternal role and false protection. PRACTICE
RECOMMENDATIONS: Facilitating maternal involvement in decision making requires
giving women unbiased information in a supportive manner.
PMID- 10693478
TI - Feeding with an umbilical arterial line.
PMID- 10693479
TI - Peripheral pulmonary stenosis murmurs.
PMID- 10693480
TI - A case study of antenatal distress and consequent neonatal respiratory distress.
PMID- 10693481
TI - Shared learning: a phenomena for celebration and a challenge to health educators.
PMID- 10693482
TI - The use of brief written educational material to promote reflection amongst
trained nurses: a pilot study.
AB - The UKCC (1995) suggest that in order for nurses to maintain their registration,
they must maintain a personal professional profile via reflection, and there are
numerous approaches to the teaching of reflection. Similarly, several models of
reflection exist. However, much of this activity has occurred without attempts to
establish the effectiveness of either reflection or attempts to teach it. The
current study attempted to examine whether written educational material could
significantly improve nurses' reflective ability. Nineteen practising nurses were
recruited from a variety of sources and offered an educational package, largely
based on Boud et al. (1985) model of reflection in learning. In a repeated
measures design study, these participants completed a reflective exercise before
and after offering of the educational material. Their scripts were rated, using
Wong et al.'s (1995) tool, by three raters, two of whom were unaware of whether
the scripts were completed before or after offering of the educational material.
An initial analysis showed that there were no statistically significant changes
in subjects' reflective ability following education. However, removal from the
analysis of 6 participants who had a pre-test ability at the highest possible
level (and for whom no improvement was, therefore, possible) resulted in a
significant improvement in participants' ability from pre- to post-test (z =
2.4450, P = 0.0145). Interrater reliability calculated using Cronbach's Alpha was
0.7210 for pretest reflective accounts and 0.7369 for post-test reflective
accounts.
PMID- 10693483
TI - Designing and implementing a 'dual diagnosis' module: a review of the literature
and some preliminary findings.
AB - People with a learning disability experience the full range of mental health
problems, with prevalence greater than in the general population. The literature
suggests that the move to community care has highlighted their special needs, as
they face a complexity of life experiences and risks. Nurses play a key role, and
must be equipped with appropriate knowledge and expertise to respond to the
mental health problems of people with a learning disability ('dual diagnosis').
Major national initiatives support research and propose access to appropriate
education for care professionals. In order to respond to locally identified
educational needs a 'dual diagnosis' module was developed for nurses working with
people with a learning disability who experienced mental health difficulties. The
aims were to increase knowledge, to consider implications for learning disability
nursing, to increase awareness of research and policy issues, and ultimately to
enhance practice. Preliminary findings suggest that participants have moved from
an entry position of professional bias and lack of knowledge and skill, to a
changed perspective and enhanced practice relating to the mental health needs of
clients with a learning disability. These changes are, however, speculative and
may be attributable to variables other than module completion. Implications for
further research and development are suggested.
PMID- 10693484
TI - Problem-based learning: an educational strategy to support nurses working in a
multicultural community.
AB - Physical dislocation of people from their homelands either as refugees,
immigrants or exiles has resulted in the creation of multicultural communities
which have diverse health needs. Like elsewhere, nurses in Australia have been
faced with the challenge of responding to an ever-changing migrant population. A
modified problem-based learning project was conducted in Melbourne to assist
nurses to enhance their practice of caring for children and families of non
English speaking backgrounds (NESB). Clinical nurses worked with the researchers
to develop and trial problem-based educational packages. The packages were
designed for use in the clinical areas and graduate nursing programs to assist
nurses overcome the cultural and communication difficulties they experienced when
caring for people of NESB.
PMID- 10693485
TI - Facilitating learning in the community with lecturer-practitioner posts.
AB - The purpose of this paper is to present a case study of the perspectives of their
role of a group of community lecturer-practitioners and a community teacher, who
referred to themselves as 'community facilitators'. A qualitative design was used
and data were collected by semi-structured interviews. These were transcribed and
content analysis was undertaken. All participants provided a liaison role between
the college and the community practitioners, prepared students for their clinical
experience and assisted in relating theory to practice. The participants
described how they managed the role and how they supported each other. Developing
small teams of facilitators may provide a bridge between teachers and
practitioners and can serve as a basis for further study of the lecturer
practitioner role.
PMID- 10693486
TI - Learning spiritual dimensions of care from a historical perspective.
AB - The purpose of this article is to bring to focus an historical perspective to the
subject of spirituality in nurse education. In doing so, the historical roots of
spirituality in nursing are traced and commented. Whilst acknowledging the
emerging perspectives on spirituality (Simsen 1986, Burnard 1986, 1987,
Narayanasamy 1991, 1993, Harrison 1993, Bradshaw 1994, Ross 1995, Oldnall 1996,
McSherry & Draper 1998) this paper attempts to address its historical dimension,
which is presently lacking in the nursing literature. In order to address this
historical gap in spirituality, this paper begins by looking at the spiritual
influences of nursing in ancient civilizations like Egypt, Mesopotamia, China,
Palestine, India, Greece and Rome and then examines the influence of
Christianity. After this, the spiritual dimension of nursing is portrayed as it
was in the Middle Ages, Renaissance, Eighteenth and Nineteenth centuries.
Finally, the emerging nursing theories and their positions on spirituality
(including those of humanists) are reviewed and commented. It is hoped that this
paper, through a brief review of events, has begun to highlight the significance
of the precursor to spirituality in nursing from an historical perspective. It is
concluded that contemporary literature suggests there is scope for development of
educational programmes to better equip nurses to meet patients' spiritual needs.
PMID- 10693487
TI - The development of NEdSERV: quantitative instrumentation to measure service
quality in nurse education.
AB - The political climate of health care provision and education for health care in
the latter years of the 20th century is evolving from the uncertainty of newly
created markets to a more clearly focused culture of collaboration, dissemination
of good practice, with an increased emphasis on quality provision and its
measurement. The need for provider units to prove and improve efficiency and
effectiveness through evidence-based quality strategies in order to stay firmly
in the market place has never been more necessary. The measurement of customer
expectations and perceptions of delivered service quality is widely utilized as a
basis for customer retention and business growth in both commercial and non
profit organizations. This paper describes the methodological development of
NEdSERV--quantitative instrumentation designed to measure and respond to ongoing
stakeholder expectations and perceptions of delivered service quality within
nurse education.
PMID- 10693488
TI - An exploratory study of nursing and medical students health promotion counselling
self-efficacy.
AB - Self-efficacy of nursing and medical students for client health promotion
counselling was examined in an exploratory study using Bandura's (1977) self
efficacy theoretical perspective. Third-year nursing students (n = 41) and fourth
year medical students (n = 60) were compared on their self-efficacy for engaging
in clients health promotion activities within 5 areas: smoking, exercise,
nutrition, sexually-transmitted diseases and injuries. Their self-efficacy about
their knowledge levels in the same 5 areas of health was also compared along with
their perceptions of the relative impact of various curricular learning
experiences on building health promotion counselling self efficacy. Self-efficacy
scores were high for both groups. Nursing students scored significantly higher on
both knowledge and ability to counsel patients in the areas of exercise,
nutrition and injury prevention. In both groups, confidence in knowledge for
health promotion activities was higher than ability to counsel patients. Learning
specific health promotion strategies in class and actual practice were strongly
associated with nursing students' self-efficacy while practice, feedback on
performance, and role modelling were strongest for medical students.
PMID- 10693489
TI - Achievement motivation, anxiety and academic success in first year Master of
Nursing students.
AB - Forty-one first semester master level nursing students from three Canadian
universities participated in this descriptive correlational study to identify the
influence of achievement motivation and anxiety on their academic success.
Academic success was determined by their first semester grade point average
(GPA). Participants had high achieving tendencies (M = 73.5) and academic ability
(M = 81.9), supporting Atkinson's (1957, 1964) achievement motivation theory
which was used as the framework. While state anxiety was negatively correlated,
trait anxiety was the only valid predictor of academic success. Academic ability
and inherent anxiety had a greater potential for predicting students who would
succeed, which has implications for nurse educators, administrators and
researchers. However, the need to assess both cognitive and non-cognitive
variables to determine master level nursing students' ability to succeed is
recommended.
PMID- 10693490
TI - Learning and teaching beyond 2000.
PMID- 10693491
TI - Insufficient evidence: the problems of evidence-based nursing.
AB - Evidence-based medicine was first proposed in the early 1990s as a means of
integrating clinical expertise with the best evidence from research. It has
recently gained a foothold in nursing, where despite calls for a broad and
nursing-oriented definition of what should count as evidence, it appears to be
propounding the randomized controlled trial (RCT) as the gold standard. This
paper challenges the wisdom of basing nursing practice on the findings of large
scale statistical research studies, and offers a number of logical objections to
the underpinning philosophy of evidence-based nursing and the randomized
controlled trial. It concludes by arguing for a rethinking of what should count
as evidence, and suggests a quasi-legal model based on reflection rather than
research, in which evidence is employed to understand and justify practice after
the event rather than being used deterministically to plan practice in advance.
PMID- 10693492
TI - Students' part-time work: towards an understanding of the implications for nurse
education.
AB - This paper reports on the subject of nursing students undertaking paid part-time
work, an area which has attracted minimal research. A questionnaire survey of 120
diploma students in one university investigated several aspects of part-time
work: incidence, nature, motivating factors, and effects on their professional
and personal lives. The results provide an insight into the work profile and the
students' perceptions of the positive and negative effects on their personal well
being and progression on the course. The findings raise issues which are of
interest to both academic and clinical staff, nursing students and employers.
PMID- 10693493
TI - Nurses' perceptions of the value of written reflection.
AB - Reflective writing is increasingly becoming a feature of professional practice as
nurses seek to provide evidence of their continuing development and competence.
This study reports the process and findings of a study using grounded theory to
explore how nurses are using and developing writing techniques as a tool for
facilitating and supporting their development in practice. Two focus group
interviews were conducted with 12 experienced nurses completing a professional
course which involved reflective writing as the assessment component over a
calendar year. These interviews generated the broad base of concepts and
categories which direct the later stages of a grounded theory study. These
preliminary categories suggest that firstly, the skills of reflective writing
need to be learnt rather than being assumed as a natural capacity; secondly, that
this leads to the acceptance of writing as a learning strategy in its own right;
thirdly, reflective writing is considered to be a tool which helps the
practitioner to develop analytical and critical abilities; finally, the nurses
identified their own personal, as well as professional growth as being
facilitated by reflective writing. Lincoln and Guba's (1985) criteria for
establishing rigour in qualitative studies, and Strauss and Corbin's (1990)
criteria for judging a grounded theory study are used as benchmarks throughout
the paper.
PMID- 10693494
TI - Attitudes of Hong Kong high school students towards the nursing profession.
AB - The increased development of hospital services in Hong Kong over the last decade
has given rise in the demand for more recruits to join the nursing profession.
Despite the advancement in education and the improvement in the working
conditions, the problems of attracting sufficient new recruits remain critical.
This study aimed to examine high school students' attitudes towards the nursing
profession and to identify the contributing factors affecting shortage of nurses
within the context of Hong Kong. A convenience sample of 375 high school students
was recruited. A questionnaire was used to measure their knowledge, attitudes and
intention to study nursing. Descriptive and inferential statistics were used to
describe their career preferences and to compare knowledge, attitudes and
intention scales between gender and nursing exposure groups. Results indicated
that the students were generally knowledgeable about nursing but were reluctant
to pursue nursing as a career. However, students who were socially acquainted
with a nurse demonstrated a slightly more positive attitude towards nursing and
slightly higher intention to pursue nursing as a career compared with those
having no social acquaintance with a nurse. Implications for promotion of nursing
profession and limitations of the study were discussed.
PMID- 10693495
TI - Change of outlook on elderly persons with dementia: a study of trainees during a
year of special education.
AB - In 1996 the Silvia Home Foundation started a non-governmental education programme
with an integrated day-care unit devoted to patients with dementia: Working
chairwoman of the foundation is HM Queen Silvia of Sweden. This study aims to
describe the trainees' changed outlook on elderly people with dementia during a
year of special education. Data were collected by interviews, informal
discussions and participant observations during the lessons. The investigation
focused on two questions: the trainees' outlook on the patients and their outlook
on the work with the patients. At the beginning of their education, the trainees
looked at the patients from a staff's perspective. During their education, this
was gradually toned down and they changed to a disease perspective, and
eventually to a human dignity perspective. After initially seeing dementia
patients as a homogeneous group, the trainees went on to see them as unique human
beings. Their outlook on their work also changed, from being task-oriented to a
more humanitarian approach.
PMID- 10693496
TI - Transfer of knowledge and skills: some implications for nursing and nurse
education.
AB - The construct of transfer has enormous importance to nursing as it begins to
highlight potential problems in the transfer of knowledge and skills from the
campus to the clinical area, from one part of the clinical area to another (e.g.
surgical to medical), and from community to the clinical area. Thus, any adequate
conceptualization of transfer must account for problems of practice-practice
transfer as well as theory-practice transfer. These potential problems are the
concern of educators, students and managers who have a responsibility for agency
nurses and bank nurses who may find themselves in different specialities on a
regular basis. Transfer has relevance to a whole raft of other issues ranging
from the application of theories to nursing practice, through to the validity of
claims that courses which develop intellectual skills prepare nurses for lifelong
learning.
PMID- 10693497
TI - Developing a distance learning honours degree in health promotion for delivery
using the Internet.
AB - Designing this programme for distance learning delivery, especially for the
Internet has been a major learning experience for all the staff involved.
However, addressing and resolving these issues has now provided us with a
template for developing other programmes in distance learning mode. This was an
endeavour that all our market research indicated we had to undertake since
institutions of higher education, especially schools of healthcare are no
different to commercial companies. Like commercial organizations, higher
education institutions, too, are consumer facing and are in direct competition
with other educational 'suppliers', i.e. other universities and colleges. If a
university is to compete and to 'sell' its products well, it too must consider
the Internet as a way of advertising its wares, streamlining its business model
and eventually conducting its business. In our case, this means delivery of
educational programmes. However, as Internet technologies are primarily designed
for research and business, there is currently a lag in the development of tools
that enable effective social learning. Our next programme via the Internet will
be even better for the experiences we've undergone and the lessons we've learnt
during this initiative.
PMID- 10693498
TI - Delphi technique: one cycle of an action research project to improve the pre
registration midwifery curriculum.
AB - Facilitating a unified interpretation of new or re-designed curricula can be
problematic in multi-sited universities. This paper discusses the use of the
Delphi technique when implementing an innovative pre-registration midwifery
curriculum. It formed one of the action research cycles of the author's doctoral
study and was used in an attempt to seek the views of all midwife teachers and
achieve a critical mass consensus. The most important issues that emerged from
the Delphi process were grouped into four categories. These four categories (the
teacher's base site, communications, staff development and administration issues)
formed the agenda for a staff away day. The outcome of the process was the
generation of a list of priorities and actions for curriculum implementation and
the identification of ways in which staff development needs might be met more
effectively. An unexpected, but equally important, outcome was the way it helped
with team building and agreement on positive actions for its further development.
PMID- 10693499
TI - Parenting by people with learning disabilities: the educational needs of the
community nurse.
AB - This article discusses some of the findings of a research project which was
designed to examine the role of community learning disability nurses in
supporting people with learning disabilities who become parents. The need for
information and help with the experience of pregnancy, childbirth, becoming
parents and bringing up children has been highlighted in a recently issued guide
for commissioning and providing services for people with learning disabilities
(NHS Executive 1998). This research, however, indicates that nurses do not feel
themselves to be adequately prepared for their role in supporting parenting.
Responses from a questionnaire survey of 266 practitioners revealed little
coverage of key issues relating to parenting on either pre-registration or post
basic courses and suggests, therefore, that some courses may not be meeting the
perceived needs of these nurses in this crucial aspect of their role. This is
likely to have significant consequences for this client group and suggests that
educationalists need to consider ways of including more extensive discussion of
parenting in educational provision for the multiplicity of professional groups
who support and care for adults with learning disabilities.
PMID- 10693500
TI - Specialist practice in community mental health nursing.
AB - Community mental health nurses (CMHNs) work in an increasingly complex health and
social care environment. Over recent years, the evolving direction of general
health service and specific mental health policy has directed CMHNs towards: the
provision of clinically-effective interventions; a closer attention to meeting
the needs of people experiencing severe and long-term mental health problems; the
simultaneous provision of services to meet the needs of people experiencing a
wide range of mental health problems presenting in primary care settings; greater
collaboration with workers representing other disciplines and agencies; and the
development of active partnerships with mental health service users. This paper
explores the context within which CMHNs practise, and within which education
programmes preparing specialist practitioners in community mental health nursing
have been developed. One recently-validated specialist practice course for CMHNs
is described in detail, with the intention of stimulating discussion and debate
surrounding the practice of, and the educational preparation for, community
mental health nursing.
PMID- 10693501
TI - UKCC Education Commission. A little fine tuning.
PMID- 10693502
TI - Party season.
PMID- 10693503
TI - Unfinished business. Interview by Charlotte Alderman.
PMID- 10693504
TI - Nature's prescription.
PMID- 10693505
TI - Smart moves. Interview by Dina Leifer.
PMID- 10693506
TI - Fighting the flu.
PMID- 10693507
TI - The painful truth.
PMID- 10693508
TI - Violence: a worldwide epidemic.
AB - Nurses are suffering from society's acceptance of violence worldwide, says the
International Council of Nurses. What is needed is a campaign of zero tolerance.
PMID- 10693509
TI - Laxatives and faecal incontinence in long-term care.
AB - High levels of faecal incontinence and laxative use in long-term care settings
for older people are revealed in this study. Further research, together with more
considered prescribing policies are needed, the authors suggest.
PMID- 10693510
TI - Investing in continence.
AB - Services for people with incontinence are dependent on location and available
resources. Sue Thomas urges nurses to be proactive in lobbying for more equity in
continence care.
PMID- 10693511
TI - Keeping the lines open.
AB - Central venous catheters (CVCs) often become occluded. Many of the guidelines for
the use of CVCs are ambiguous and do not offer clear guidelines for
practitioners. This article discusses the development of a local policy for
maintaining or increasing the patency of CVCs in acutely ill adults.
PMID- 10693512
TI - The benefits of hypodermoclysis.
AB - Hypodermoclysis (subcutaneous fluid administration) is a valuable means of
replacing fluids and maintaining hydration for older people and palliative care
patients. This literature review looks at three aspects of the therapy--client
groups, wound care and types of infusion fluids.
PMID- 10693513
TI - Assertiveness, power and influence.
AB - This article describes how nurses can use the concepts of assertiveness, power
and influence to maximise their effectiveness in delivering care and bringing
about change.
PMID- 10693515
TI - Learning disability nursing--holistic care at its best.
PMID- 10693514
TI - Giving injections.
PMID- 10693516
TI - A balance of power.
PMID- 10693517
TI - [We will have to work together].
PMID- 10693518
TI - [Accreditation, a landmark].
PMID- 10693519
TI - [The process of accreditation from the viewpoint of the nursing service].
PMID- 10693520
TI - [Accreditation. The Canadian model, the medical viewpoint].
PMID- 10693521
TI - [Accreditation. A tool to serve the improvement of quality].
PMID- 10693522
TI - [Accreditation. An admission strategy, a means of patient-centered care].
PMID- 10693523
TI - [Accreditation. Participation of the consumers in the evaluation of
satisfaction].
PMID- 10693524
TI - [Therapeutic impasse. The capacity to make everything fail].
PMID- 10693526
TI - [Surfing in nursing care].
PMID- 10693525
TI - [Short term therapy, another look at the change].
PMID- 10693528
TI - [The National Network of Hospital Documentors, a network to be discovered] [In
Process Citation]
PMID- 10693527
TI - [The birth of Nursing Convergence upsets the French nursing syndical scene] [In
Process Citation]
PMID- 10693529
TI - [A new decree for a unique competency] [In Process Citation]
PMID- 10693530
TI - [Finding a manageable distance].
PMID- 10693531
TI - [Sexual delinquency, reference points].
PMID- 10693532
TI - [The law of June 17, 1998].
PMID- 10693533
TI - [Respecting every type].
PMID- 10693534
TI - [The judge pronouncing the fine, focus of application. Interview by Francois
Hamon].
PMID- 10693535
TI - [Incarceration of sex delinquents. Interview by Francois Hamon].
PMID- 10693536
TI - [The pervert, the law and the therapist].
PMID- 10693537
TI - [Approach to the care of a pedophile].
PMID- 10693538
TI - [Psychotherapies of sex delinquents].
PMID- 10693539
TI - [1999, psychiatry of the stone age].
PMID- 10693540
TI - [A disarmed nursing team].
PMID- 10693542
TI - [We need a law to develop palliative care]
PMID- 10693541
TI - [Surfing in nursing care].
PMID- 10693543
TI - [Rare diseases and the health care system, 1. citizens' forum] [In Process
Citation]
PMID- 10693544
TI - Ultrasonography as adjunct to mammography in the evaluation of breast tumors.
AB - PURPOSE: The aims of the study was to analyze the features of cancers missed as
tumor on ultrasonography (US), to determine the predictive power of US tumor
descriptors in the differentiation of benign and malignant breast tumors, to
evaluate US as adjunct to mammography, and to assess the validity and reliability
of mammographic, US, and combined interpretation of breast tumors. MATERIAL AND
METHODS: Prospectively recorded mammographic and US findings of 355 malignant
breast tumors among 2,985 consecutive patients who underwent breast US were
compared with clinical findings and pathologic subtypes of the tumors. In
addition, a 10-year material of 95 invasive lobular carcinomas (ILCs) were
investigated. Three retrospective studies assessed the validity and reliability
of mammographic, US, and combined interpretation of 200 palpable mammographically
noncalcified breast masses by four radiologists. RESULTS: A total of 97.5% of the
palpable and 67.9% of the nonpalpable malignant neoplasms were detected as tumor
on US. Most carcinomas missed as tumor on US were ductal carcinomas in situ
(DCISs) and microinvasive ductal cancers dominated by DCIS manifesting with
suspicious calcifications on mammography. Irregular shape, irregular contour,
extensively hypoechogenicity, hyperechoic rim (halo), and distortion of the
surrounding tissue were the US features with the highest odds of predicting
carcinomas. A pseudocapsule is the strongest predictor of a benign tumor, the
odds of cancer being 0.03 in nonpalpable and 0.08 in palpable breast tumors. A
negative predictive value of 100% in palpable and 96% in nonpalpable tumors was
achieved using strict US criteria. In patients with ILC, US measurements
predicted tumor size more accurately than mammography. US as adjunct to
mammography correctly diagnosed ("upgraded") 9.5% of tumors with benign or
indeterminate mammographic diagnoses. Excluding mammographically conclusive
malignant tumors and carcinomas presenting with microcalcifications. US correctly
upgraded 42% of the palpable and 44% of the nonpalpable cancers. Combined
mammographic-US interpretation offers the highest diagnostic performance in
noncalcified breast tumors. The lowest interobserver agreement was found in US
interpretation. CONCLUSION: The impact of US in mixed cancer populations is
limited. US is, however, a valuable adjunct to mammography in patients with
nonconclusive mammographic findings. Negative predictive values on US approaching
100% may be achieved using strict criteria for a benign diagnosis. A considerable
interobserver variation in the US interpretation is a limiting factor for the
potential of breast US in the differentiation of benign and malignant breast
tumors.
PMID- 10693545
TI - Transplantation of tissue from lower animals to man, and a report of the case of
bone-transplantation at Charity Hospital, Blackwell's Island, N.Y. 1891.
PMID- 10693546
TI - Bone graft materials. An overview of the basic science.
AB - Autograft, allograft, and synthetic bone graft substitute materials play an
important role in reconstructive orthopaedic surgery, and understanding the
biologic effects of these materials is necessary for optimum use. Although
vascularized and cancellous autograft show optimum skeletal incorporation, host
morbidity limits autograft availability. Experimental studies have confirmed an
immune response to allograft bone, but the clinical significance of this response
in humans still is unclear. Small amounts of cancellous allograft in humans
usually are remodeled completely; large allografts become incorporated by
limited, surface intramembranous bone formation suggesting that these graft are
primarily osteoconductive. Several synthetic skeletal substitute materials also
are osteoconductive, and may show remodeling characteristics similar to
allograft. Demineralized bone matrix and some isolated or synthetic proteins can
induce endochondral bone formation, and therefore are osteoinductive. The extent
and distribution of remodeling of bone graft materials are influenced by many
factors, including the quality of the host site and the local mechanical
environment (strain). Graft materials are likely to become more specialized for
use in specific clinical applications, and composite preparations may soon
provide bone graft materials with efficacy that equals or exceeds that of
autogenous grafts.
PMID- 10693547
TI - Posterolateral and anterior interbody spinal fusion models in the sheep.
AB - Posterolateral and anterior interbody spinal arthrodesis is a frequent procedure,
but high nonunion rates are reported and harvesting autologous bone graft from
the iliac crest significantly increases morbidity. Bone graft substitutes are an
alternative, but to date clinical results are not conclusive. Bone substitutes
can be organic or inorganic, biologic or synthetic. They can have osteoconductive
properties, inductive properties or both. Animal experiments are essential to
investigating bone substitutes using biomechanical and histologic methods not
available in clinical studies. Few authors reported on instrumented anterior
fusion models, but none used the sheep model. In the current study posterolateral
and anterior interbody fusion models in sheep are described. Both models used
instrumented fusions, applying porous mineral scaffolds, alone or mixed with
bone. The surgical techniques are described step-by-step and potential
difficulties are highlighted. Preliminary results are reported for the
posterolateral fusion model using coralline graft substitutes. The coral granules
mixed with locally harvested bone had fusion outcomes similar to pure autologous
bone. The graft substitute showed marked resorption between 12 and 20 weeks. All
fusions had bone cortex and good trabecular connectivity. Histologic evaluation
suggests after 20 weeks nearly the entire surface of the substitute is covered
with new bone. Porous mineral bone substitutes mixed with locally harvested
autologous bone are thought to be a valid alternative for posterolateral fusions.
PMID- 10693548
TI - The use of allograft bone in lumbar spine surgery.
AB - Bone grafting is an integral part of many lumbar spinal surgeries. The two
choices of bone are autograft and allograft. Each source has its own advantages
and disadvantages. The current study is a literature review of allograft bone use
in lumbar spine surgery. Allograft bone can be procured in greater quantities
than autograft. With standard protocols of harvesting, the risk of disease
transfer is negligible. Only fresh-frozen and freeze-dried products are used.
Allografts are incorporated slower and to a lesser degree than autografts. Fresh
frozen grafts are stronger, more immunogenic and more completely incorporated
than freeze-dried grafts. Allografts used alone or combined with autografts for
posterior lumbar spinal procedures have decreased fusion rates compared with
autografts. If used anteriorly, allografts are well suited for reconstructive
procedures and have good fusion rates, especially if combined with posterior
fusions. If used in the proper situations, allograft bone can be used
successfully in lumbar spine surgeries.
PMID- 10693549
TI - Pseudarthrosis repair. Autogenous iliac crest versus femoral ring allograft.
AB - Pseudarthrosis repair in the lumbar spine is one of the most challenging problems
faced by spine surgeons. Historically high failure rates with posterior repair
have led to the use of anterior lumbar interbody fusion with tricortical iliac
crest autograft in these difficult cases. More recently, femoral ring allografts
packed with autograft bone have been advocated as another method that would
decrease donor site morbidity. Two series of patients underwent anterior lumbar
interbody fusion with anterior instrumentation to repair pseudarthrosis (Group I,
33 patients with tricortical autogenous iliac crest and Group II, 20 patients
with femoral ring allografts). At minimum 2-year followup, there was no
difference in fusion rates (Group I, 32 of 33 versus Group II, 20 of 20).
Patients in Group I had radiographic fusion develop more rapidly than patients in
Group II (12 months versus 18 months), but a significant proportion of patients
in Group I (35%) had an average of 2 mm of graft subsidence. Despite excellent
fusion rates in both groups, functional outcomes were not as good with only 28%
of patients in Group I and 36% of patients in Group II returning to work. Using
anterior instrumentation, anterior interbody fusion offers an excellent method to
repair pseudarthrosis using femoral ring allografts or autogenous iliac crest.
However, femoral ring allografts offer the potential to decrease donor site
morbidity, allowing the surgeon to treat multiple spine levels.
PMID- 10693550
TI - Anterior lumbar interbody fusion with osteoinductive growth factors.
AB - Anterior intervertebral fusion increasingly is used as a treatment for discogenic
or intersegmental pathologic diseases of the lumbar spine. This is in part
attributable to the evolution and refinement of laparoscopic and minimally
invasive surgical techniques that now can be used to access the anterior spinal
column. It also is attributable to the availability of newer generation
intervertebral fixation devices such as the threaded titanium cages or threaded
allograft bone dowels, both of which are technically simpler to implant.
Recently, limited clinical studies of intervertebral lumbar fusion have examined
the use of these devices combined with osteoinductive growth factors as
substitutes for autogenous bone graft. Early clinical results of lumbar fusion
using threaded intervertebral implants filled with recombinant human bone
morphogenetic protein-2 have been favorable. Higher fusion rates, shorter
operative times, and shorter hospital stays have been reported in the initial
series. Clinical trials involving larger cohorts with various spinal applications
for osteoinductive molecules currently are in progress.
PMID- 10693551
TI - Human bone morphogenetic protein allografting for reconstruction of femoral
nonunion.
AB - A composite inductive allograft consisting of an allogeneic, autolysed, antigen
free cortical bone carrier lyophilized with partially purified human bone
morphogenetic protein was implanted in 30 consecutive femoral reconstructions
that resulted from failure of fracture healing. There were 24 atrophic shortened
femoral nonunions, four equal length femoral nonunions, and two femoral
malunions. There were 10 men and 20 women with an average age of 47 years (range,
28-75 years). Allogeneic, autolysed antigen-free cortical bone was used as a
structural alloimplant and as a delivery system for partially purified human bone
morphogenetic protein. The composite implant of human bone morphogenetic
protein/allogeneic, autolysed antigen-free cortical bone was used in conjunction
with one-stage lengthening of the extremity, restoration of mechanical axis and
rotational alignment. In 26 of 30 femurs, the human bone morphogenetic
protein/allogeneic autolysed antigen-free cortical bone consisted of an
allogeneic cortical bone implant incorporated into a one-stage lengthening of
atrophic femoral nonunion. In four patients with equal length femoral nonunions,
the human bone morphogenetic protein/allogeneic, autolysed antigen-free implant
was placed as an medical femoral shaft onlay graft. Internal remodeling of the
implant occurred within 8 to 12 weeks after implantation. Lengthening defects
greater than 2 cm were supplemented with intercalary autogeneic bone graft.
Twenty-four femurs healed at an average of 6 months at an average followup of 55
months. Four of six plate fatigue failures were salvaged with repeat plating. Two
patients were lost to followup. The human bone morphogenetic protein/allogeneic,
autolysed antigen-free bone allograft is an excellent structural and delivery
system that induces host bone formation and implant remodeling allowing salvage
of difficult femoral nonunions.
PMID- 10693552
TI - Minor column structural acetabular allografts in revision hip arthroplasty.
AB - A minor column (shelf) allograft is used for uncontained defects that involve
less than 50% of the acetabulum. The prospectively collected records and
radiographs of 47 patients (51 hips) who had undergone minor column structural
acetabular allograft reconstruction during revision hip arthroplasty were
reviewed. The purpose was to identify the long-term results (minimum 5 years) and
factors that may influence longevity of the allograft and predispose the patient
to subsequent acetabular component failure. The mean duration of followup was 119
months (range, 68-195 months). There was one perioperative death and six patients
were lost to followup. Eleven patients (22%) required additional surgery. Three
acetabular cups could not be revised successfully, despite multiple attempts, and
the patients were treated with Girdlestone excisions. Eight patients underwent
successful revision surgery with only three requiring a repeat structural
allograft. Survival time for the acetabular cup as determined by Kaplan-Meier
analysis was 153 months (95% confidence interval; range, 136-169 months). Cup
failure was associated with more operative procedures performed before revision
surgery (mean, 3.2 procedures), and failure to restore the vertical center of hip
rotation to within 12 to 14 mm of the predicted value. The acetabular abduction
angle was not a predictor for failure. The current study shows that good results
can be achieved with structural acetabular allograft reconstruction with mid-term
to long-term implant survival (cup aseptic survival, 80.4% and allograft re
construction survival, 94.1%), especially if there is restoration of near normal
hip biomechanics.
PMID- 10693553
TI - Cancellous allograft in revision total hip arthroplasty. A clinical review.
AB - There are numerous indications for the use of cancellous allograft bone in the
context of revision hip arthroplasty. These indications range from the well
documented use of morselized bone chips to fill cavitary defects during
cementless acetabular reconstructions--in which complete or near-complete graft
remodeling is expected--to the use of particulate allografting with bipolar
hemiarthroplasty for acetabular revision, which largely has been abandoned
because of frequent component migration, graft resorption, and clinical failure.
Most other indications, including femoral and acetabular impaction allografting
techniques, curettage of osteolytic defects with component retention, and complex
reconstructions using acetabular reconstruction rings or cages with cancellous
donor bone, are controversial but are supported by published clinical series. The
current study reviews the literature on cancellous allografting in revision total
hip arthroplasty.
PMID- 10693554
TI - Circumferential allograft replacement of the proximal femur. A critical analysis.
AB - The use of proximal femoral structural allografts in revision hip arthroplasty
remains controversial. The current study constitutes the mean 8.8 years followup
(range, 3-12.5 years) of a consecutive series of 55 proximal femoral allografts
in 51 patients. In 46 patients the implant was cemented into the allograft and
the distal femur, and the host proximal femur was resected at the time of
reconstruction in all but seven patients. Five patients underwent revision
surgery for acetabular failure, and six additional patients underwent revision
surgery for failure of the proximal femoral allograft. Three patients underwent
successful revision surgery and had additional proximal femoral allografts.
Failure was caused by graft fracture in one patient, by deep infection in two
patients, and by junctional nonunion in three patients. Junctional nonunion was
seen in five patients (9%), two of whom were treated successfully with bone
grafting and bone grafting and plating, respectively. Instability was observed in
six patients (11%). Trochanteric nonunion was seen in 22 patients (43%) and
trochanteric escape was seen in 14 patients (27%). The mean Harris hip score
improved from 39 to 79 points. Resorption involving the full thickness of the
allograft in at least one zone was seen in seven patients. This progressed
rapidly and silently within the first 3 years but has yet to lead to the failure
of any of the reconstructions. Infection was ruled out in every case. Allograft
resorption was seen in seven patients and may be related to a combination of
factors. It is most likely that this is an immunologic problem of slow rejection,
but it is possible that the distal cement fixation led to stress shielding and
resorption attributable to mechanical disuse. The possible protective role of
retaining the bivalved host bone as a vascularized onlay autograft remains to be
clarified. Although these results justify the continued use of structural
allografts for selected patients, continued followup is warranted.
PMID- 10693555
TI - Results of onlay allografts.
AB - Cortical onlay strut allografts provide a method for bone restoration when
performing revision surgery in a patient with a structurally deficient femur.
Between 1986 and 1990, 251 patients underwent femoral revisions using structural
onlay bone grafts. The followup ranged between 8 and 12 years, with the average
followup being 9.5 years. All of the grafts united to the host bone. The revision
rate in the current series is 3%, with no complications related to the bone
graft. The average Harris hip score improved 45 points. Cortical onlay grafts are
used for patients with structurally deficient femurs. After union occurs, the
graft undergoes adaptive remodeling, secondary to physiologic load bearing. This
technique has proved to be a reliable method for bone restoration in the patient
with a structurally compromised femur.
PMID- 10693556
TI - Revision total knee arthroplasty by impaction bone grafting.
AB - The presence of bone loss in a failed total knee arthroplasty can present a
significant reconstructive challenge. Experience with the technique of using
impacted morselized allograft with revision components having fixed stems is
presented. Nineteen knees (21 patients) were reconstructed using impacted bone
graft alone in 14 knees, bone graft plus methylmethacrylate in five knees
(including one knee in which the replacement failed), and in three knees
morselized bone graft was used in conjunction with structural bone allograft.
Minimum followup ranged from 6 months to 62 months for the patients in the
current series. These patients represent a relatively small, but growing portion
of this surgeon's population of patients undergoing revision knee arthroplasty.
Patients with large defects were selected for the study. Histologic specimens
from the one failed knee arthroplasty revealed viable, incorporated bone graft.
Excluding the replacement that failed, the average improvement in Knee Society
combined knee and function scores was 87 points. The principles of revision and
primary total joint arthroplasty are applied for achieving a stable implant.
Specific to this technique, solid support of the implant-graft interface, graft
host bone interface, and the use of a tight, supportive stem is imperative. The
author's experience provides additional support for the use of bone grafting
techniques in patients with large bone defects who are undergoing revision total
knee replacement.
PMID- 10693557
TI - Surgical management of Sprengel's deformity in adults. A report of two cases.
AB - Sprengel's deformity is a congenital structural abnormality of the shoulder
girdle, and most patients with Sprengel's deformity receive surgical treatment as
a child or adolescent. Thus, it is uncommon to identify an adult with untreated
Sprengel's deformity. Two adult patients who had no previous surgical treatment
were treated with resection of an omovertebral bone and resection of the
superomedial border of the scapula. This procedure was not overly invasive or
technically demanding. In both patients resection of the omovertebral bone
provided an improved cosmetic appearance and reduction in neck pain, although
shoulder motion was improved in only one patient. Because the patient with a long
omovertebral bone adjacent to the levator scapulae muscle showed great
improvement in her shoulder motion, the size, shape, and position of the
omovertebral bone may predict improvement of shoulder motion after resection.
Thus, the surgical treatment of adults patients with Sprengel's deformity can
produce good surgical results.
PMID- 10693558
TI - Successful restoration of the trapezius muscle using pedicle latissimus dorsi. A
case report.
AB - Reconstruction of the trapezius muscle using a pedicle latissimus dorsi flap was
performed in a 27-year-old man with a large synovial sarcoma in his shoulder
girdle. Size and location of the tumor required combined resection of surrounding
muscles, including the trapezius, levator scapulae, and rhomboid major and minor.
Thus, an extensive defect of the suspending muscles of the scapula was created
after accomplishing an adequate resection of the tumor. The flap was performed to
restore the trapezius functionally because there were no adjacent muscles
available. The transferred muscle compensated for loss of the trapezius, thereby
recovering excellent shoulder function. Although an opportunity of its
application is thought to occur infrequently, the pedicle latissimus dorsi can
activate scapular motion successfully in the absence of the levator scapulae. The
technique may be extended to salvage failed conventional reconstruction after
spinal accessory nerve palsy.
PMID- 10693559
TI - Palmar approach in flexible implant arthroplasty of the proximal interphalangeal
joint.
AB - Joint replacement is an established method in the treatment of destroyed,
painful, proximal interphalangeal joints. A palmar approach was used in which the
main collateral ligaments were preserved, allowing immediate active
rehabilitation with enhanced primary lateral stability. Fifty-nine proximal
interphalangeal joint silicone arthroplasties in 38 patients with a minimum
followup of 12 months were reviewed. Thirty-eight of the 59 joints had
implantation from a palmar approach and 21 joints from a dorsal approach. The two
groups were well-matched in terms of indication, preoperative range of motion,
and patient age. No significant increase in the range of motion was found in
either of the patient groups, with an overall average range of motion of 51
degrees postoperatively. There was also no significant difference in the
postoperative stability in the two patient groups. The choice of surgical
approach at the proximal interphalangeal joint level for the silastic type of
implants does not appear to be important. With more sophisticated types of
implants in which the integrity of the collateral ligaments is crucial, a palmar
approach might be beneficial.
PMID- 10693560
TI - Hip and knee replacement after longstanding hip arthrodesis.
AB - This study determined whether patients with severe knee disease below a hip
arthrodesis can be treated successfully with total knee replacement alone or
whether such patients require total hip arthroplasty followed by knee
replacement. Eighteen patients who had hip arthrodesis for a mean of 33 years
underwent total hip replacement alone, total knee replacement alone, or a
combination of both. The Harris hip score improved from a mean of 55.3 to a mean
of 86.9 points at 45 months after total hip arthroplasty. The Hospital for
Special Surgery knee score improved from a mean of 33 to a mean of 78 points in
patients who had total knee replacement after total hip arthroplasty. The
Hospital for Special Surgery knee score improved from a mean of 35 to a mean of
44 points in patients having total knee replacement alone below a hip
arthrodesis. The followup after total knee replacement averaged 53 months. These
data suggest that a knee replacement alone in a patient with a fused hip is
unlikely to provide a satisfactory result. Patients with severe knee disease
below hip arthrodesis require total hip arthroplasty followed by knee
replacement. This applies even when severe osteoarthritis of the knee is the
primary complaint.
PMID- 10693561
TI - Influence of porous coating level on proximal femoral remodeling. A postmortem
analysis.
AB - This study used femurs retrieved at autopsy to compare the extent and location of
bone remodeling between four patients implanted with proximally porous coated
femoral prostheses and a matched group of four patients implanted with
extensively porous coated femoral prostheses. The femoral components studied were
large, cementless, straight, cobalt chrome stems and were identical except for
the amount of porous coating. The contralateral normal femur of each patient also
was retrieved, implanted with an identical prosthesis, and used as a control for
bone mineral content. Dual energy x-ray absorptiometric analysis showed marked
loss of bone mineral content in both groups of patients. The extensively coated
group had less bone loss on average (18.4%) than did the proximally coated group
(38.6%). There was no relationship between the extent of coating and the location
of bone mineral loss; specifically, proximal coating did not protect against loss
of bone mineral content proximally or distally in the femur. Videodensitometric
analysis of cross sections of periprosthetic bone also showed that the
extensively coated group tended to have less decrease in bone density than did
the proximally coated group (14.3% versus 28.4%). Although one cannot presume
that all proximally fixed stem designs would produce results similar to those
presented here, these findings show that decreasing the extent of porous coating
alone does not necessarily reduce proximal femoral bone loss.
PMID- 10693562
TI - Bilobed oblong porous coated acetabular components in revision total hip
arthroplasty.
AB - Thirty-eight oblong bilobed noncustom uncemented, porous-coated titanium
acetabular components were used to reconstruct failed hip arthroplasties with
large superior segmental acetabular bone deficiencies. No structural bone grafts
were used. All patients were followed up for 2 to 5 years (mean, 3 years) after
the operation. One patient (whose socket rested primarily on a structural bone
graft from a previous procedure) had revision surgery for acetabular loosening.
No other patients have had revision surgery or had another ipsilateral hip
operation. At latest followup, 35 patients had no or mild pain and two patients
had moderate pain. Two implants migrated more than 2 mm in the first year, then
stabilized. On the latest radiographs, two implants had bead shedding, but there
was no measurable migration or change in position. For selected patients with
large superolateral acetabular bone deficiencies, this implant facilitated a
complex reconstruction, provided good clinical results, and showed satisfactory
stability at early to midterm followup in most patients.
PMID- 10693563
TI - Subvastus and medial parapatellar approaches in total knee arthroplasty.
AB - This retrospective study compared the outcome of two consecutive groups of
patients having primary total knee arthroplasty. The arthroplasties were
performed in the first group (169 arthroplasties in 143 patients) from 1988 to
1992 using a medial parapatellar approach, and in the second group (167
arthroplasties in 148 patients) from 1992 to 1996 using a subvastus approach. The
patient outcomes were evaluated at 6 months, and were based on clinical and
radiographic measures, occurrence of intraoperative lateral retinacular release,
and incidence of postoperative patellar subluxation. There were no significant
differences between the two groups for range of motion, Knee Society knee and
function scores, and stair climbing ability. The patella tracked centrally in
significantly more knees with the subvastus approach (139 of 167 knees, 83%) than
with the parapatellar approach (107 of 169 knees, 63%). There were significantly
fewer knees in the subvastus group requiring a lateral retinacular release (62 of
167 knees, 37%), compared with the parapatellar group (113 of 169 knees, 67%).
The authors concluded that the subvastus approach led to improved patellar
tracking and stability. Although the surgical and rehabilitative protocols were
identical for both groups, the results may have been affected by changing
circumstances during the 9-year period of the study.
PMID- 10693564
TI - Effect of tourniquet use on activation of coagulation in total knee replacement.
AB - Total knee replacement often is performed with tourniquet application. The
advantages of a dry field, including fixation, are well known, but it still is
debatable if tourniquet application increases deep vein thrombosis. Measurement
of coagulation markers is a well accepted method of studying thrombogenesis
activation intraoperatively and postoperatively. Twenty patients undergoing total
knee replacement with subarachnoid anesthesia were assigned randomly to two
groups: either with tourniquet application (Group I) or without tourniquet
application (Group II). There were no differences between patients in the two
groups in terms of age, gender, diagnosis (all had osteoarthritis), operative
time, and total (intraoperative and postoperative) blood loss. Markers for
thrombin generation and fibrinolysis were measured. Blood samples were drawn at
four times: baseline before the operation; after bone cuts; after cement fixation
(Group II) or 2 minutes after tourniquet deflation (Group I); and 1 hour after
surgery. Markers of thrombin generation and fibrinolysis showed a significant
increase from baseline in all the patients. In Group II these markers started to
increase during surgery, whereas in Group I the increase occurred at the end of
the procedure when the tourniquet was deflated. The total amount of thrombin
generation was significantly higher in Group II (without tourniquet), whereas
fibrinolysis was significantly greater in Group I. Total knee replacement is
accompanied by a hypercoagulative state with or without the use of a tourniquet,
but it seems to be higher when the tourniquet is not used. In addition,
tourniquet application may increase fibrinolysis.
PMID- 10693565
TI - Axis location of tibial rotation and its change with flexion angle.
AB - The magnitude and location of the axis of tibial rotation were measured at 15
degrees increments between 0 degree and 90 degrees flexion using 24 normal
anatomic knee specimens, and their changes with flexion angle were investigated.
The magnitude of tibial rotation was small (8.3 degrees) at 0 degree flexion, but
increased rapidly as the flexion angle increased and reached a maximum rotation
(31.7 degrees) at 30 degrees flexion. It then decreased again with additional
flexion (24.8 degrees at 90 degrees flexion). The location of the axis was close
to the tibial insertion of the anterior cruciate ligament at 0 degree flexion,
gradually moving toward insertion of the posterior cruciate ligament (observed at
45 degrees and 60 degrees flexion), and then moved anteriorly again with
additional flexion: the axis was approximately equidistant from the two cruciate
insertions at 90 degrees flexion. The results showed that a relatively large
degree of tibial rotation was possible in a normal knee and that the location of
the axis remained approximately in the area between the two cruciate ligament
insertions throughout the range of flexion. However, the location of the axis
changed with the flexion angle within this area according to the changes in
direction and tension of the cruciate ligaments and the surrounding soft tissues.
PMID- 10693566
TI - Augmented amputations of the lower extremity.
AB - Ten patients who had amputations of a lower extremity for high-grade sarcomas
underwent bone augmentation with either allograft or autograft between 1988 and
1996. There were eight transfemoral amputations and two transtibial amputations.
The transferred segments consisted of one proximal tibia and six distal tibia
autografts, two allografts, one autograft talar dome and first metatarsal, and
one with a patellar cap of a supracondylar amputation. The average length of
followup was 54 months. There were no nonunions of any of the grafts. There were
three wound problems requiring additional operations. One autograft resorbed, and
one autograft had a late infection. There was one local recurrence. Augmentation
to provide length resulted in a 42% increase in bone length in those performed
purely for length. All patients were able to use standard prostheses. Functional
outcome was appropriate to the amputation level. Half of the patients avoided
more proximal levels of amputation because of the ability to augment the
osteotomy. The use of nonvascularized structural autografts or allografts is a
simple procedure that can produce a superior residual limb in patients undergoing
amputation. Its use should be considered in patients for whom traditional
amputation techniques will result in poor function, difficulty in fitting a
prosthesis, or greater than necessary anatomic loss.
PMID- 10693567
TI - Fixation of large segment femoral allografts using plates augmented with cerclage
wires.
AB - Results using plates augmented with cerclage wires to stabilize eight large
segment femoral allografts are described. Two patients had plates augmented with
cerclage wires placed at the time of tumor resection, and six patients had plates
augmented with cerclage fixation placed to manage allograft nonunions or
fractures. These internal fixation techniques spanned 10 osteotomy sites: two
metaphyseal and eight diaphyseal. The goal of operations that involved internal
fixation with plates augmented by cerclage fixation was to obtain osseous union.
Osseous union was achieved at both metaphyseal osteotomy sites and at one of the
diaphyseal osteotomy sites. Internal fixation of large segment allografts with
plates that are augmented with cerclage wires yield poor results when osseous
union is the goal of treatment.
PMID- 10693568
TI - Cemented hemiarthroplasties for elderly patients with intertrochanteric
fractures.
AB - The results of 55 consecutive hemiarthroplasties in 54 elderly patients with
intertrochanteric fractures were reviewed. The mean age of the patients was 84.2
years (range, 73-99 years). Standard cemented hemiarthroplasty was used and the
fractured posteromedial fragment was retained. Two patients were lost to followup
and 12 patients died within 6 months of their fractures. The mean length of
followup was 13.6 months (range, 6-24.6 months) for the remaining 40 patients (41
hips). Nineteen patients maintained the same walking category as before fracture
and eight of these patients had no increase in the dependency on walking aids.
The greatest deterioration of walking function occurred in the subgroup of six
patients who had a history of confusion and frequent falls. The medical
complications are comparable with those described in other series. There were few
surgical complications. The authors of this study think that the use of standard
cemented hemiarthroplasty is a reasonable alternative to a sliding screw device
for the treatment of intertrochanteric fractures. Longer-term studies with larger
numbers of patients are required to address the issues of late complications and
whether the reconstructions are durable enough for the long-surviving patients.
PMID- 10693569
TI - Adverse tissue reactions to bioabsorbable fixation devices.
AB - Among 2528 patients operated on using pins, rods, bolts, and screws made of
polyglycolic acid or polylactic acid, 108 (4.3%) were affected by a clinically
significant local inflammatory, sterile tissue reaction. The three most common
indications for the use of these fixation devices were a displaced malleolar
fracture, a chevron osteotomy for hallux valgus, and a displaced fracture of the
radial head. In 107 patients, the reaction was elicited by a polyglycolic acid
implant, and in one patient by a polylactic acid implant. The incidences were
5.3% (107 of 2037) and 0.2% (one of 491), respectively. The adverse tissue
responses to polyglycolic acid were seen 11 weeks after the operation, on
average, whereas the reaction to polylactic acid occurred 4.3 years after
fixation of an ankle fracture. The mild reactions consisted of a painful
erythematous papule of a few weeks' duration. Those of medium severity had a
sinus that discharged remnants of the implant for up to 6 months. In the patients
affected by severe reactions, extensive osteolytic lesions developed at the
implant tracks. The histopathologic picture was that of a nonspecific foreign
body reaction. In four patients with vigorous reactions, an arthrodesis of the
wrist or ankle later was necessary because of severe osteoarthritis. Several
markers of increased risk of the occurrence of a foreign body reaction were
found. These included a poorly vascularized bone section such as scaphoid, use of
a quinone dye as an additive in the polymer, and an implant geometry with large
surface area (screw versus pin or rod). For polyglycolic acid implants, the risk
of an adverse tissue response in a given clinical situation can be estimated from
the findings of this study. For slow degrading polymers like polylactic acid,
however, the ultimate biocompatibility still is unsettled, and additional
clinical research with long followup is required.
PMID- 10693570
TI - Effect of collagen denaturation on the toughness of bone.
AB - The purpose of this study was to explore the relationship between the integrity
of collagen and biomechanical properties of bone. In this study, age (range, 5-26
years old) and gender related changes in cortical bone samples from 33 baboon
femurs (15 males and 18 females) were examined. The percentage of denatured
collagen was determined using a selective digestion technique. The fracture
toughness, elastic modulus, yield and ultimate strength, and energy to fracture
of bone were determined in three-point bending configurations. The porosity and
weight fractions of the mineral and organic phase also were measured. A two-way
analysis of variance showed that age dependent changes were reflected primarily
in the amount of denatured collagen, fracture toughness, energy to fracture, and
elastic modulus, whereas gender had effects on the fracture toughness, elastic
modulus, and porosity of bone. In addition, regression analyses indicated that
the percentage of denatured collagen had an inverse correlation with the
toughness of bone and a positive correlation with its elastic modulus, whereas
mineral content had positive correlation with the strength and elastic modulus of
bone. The results of this study suggest collagen influences the toughness of
bone, whereas mineral content predominantly contributes to bone stiffness and
strength.
PMID- 10693571
TI - Bone graft incorporation. Effects of osteogenic protein-1 and impaction.
AB - Impaction of cancellous bone grafts in a bone chamber in rats in a previous study
led to decreased ingrowth of new bone after 6 weeks compared with unimpacted
grafts. The current study analyzes whether this decrease represented a final loss
of ingrowth or just a delay, if the decrease was influenced by immunologic
factors, and if it was possible to influence the inhibitory effect by adding a
bone morphogenetic protein. Bone chambers with impacted or unimpacted bone grafts
were implanted bilaterally in rat tibias. The mean bone ingrowth distance into
the graft was measured on histologic sections. Three experiments were done: (1)
the bone ingrowth into impacted and unimpacted grafts was studied at 6 and 12
weeks; (2) the immunologic influence was studied by comparing isogeneic grafts
with allogeneic grafts; and (3) the authors tried to influence the decrease in
bone ingrowth in impacted grafts by adding osteogenic protein-1. Bone ingrowth
into the impacted graft was decreased at 6 weeks but not at 12 weeks. No
difference was found between isografts and allografts at 6 weeks. With the
addition of osteogenic protein-1, the impacted grafts showed dramatically
increased bone ingrowth. Impacted bone grafts are incorporated at a slower rate
than were structural grafts. The delay can be reversed by adding osteogenic
protein-1, making ingrowth faster than in structural bone.
PMID- 10693572
TI - Does axial limb rotation affect the alignment measurements in deformed limbs?
AB - The long-term outcome of total knee arthroplasty and femoral or tibial osteotomy
is related to the ability of the surgeon to achieve the desired alignment based
on preoperative planning. This study evaluates the effect of axial rotation on
measured tibiofemoral angles and the angle formed between the anatomic and
mechanical axes of the femur in lower extremities with valgus and varus
deformities. A comparison study of the measured tibiofemoral angles indicated a
statistically significant effect in models with severe vagus or varus deformity
when rotated 10 degrees internally or externally. In the second part of the
study, the measured angle between the anatomic and mechanical axes of the femur
never varied by more than 1 degree, despite a 40 degrees are of rotation. The
results of the study indicate the tibiofemoral angle measurements are more
sensitive to axial limb rotation in lower extremities with valgus or varus
deformity than are normally aligned limbs. In preoperative planning of total knee
arthroplasty, the measured angle between the anatomic and mechanical axes of the
femur is less effected by limb rotation, regardless of the degree of valgus or
varus deformity.
PMID- 10693573
TI - Buttock pain in a 48-year-old man.
PMID- 10693574
TI - Orthopaedics, ethics, and industry. Appropriateness of gifts, grants, and awards.
AB - At the Academic Orthopaedic Society meeting in San Francisco on November 8 and 9,
1996, the membership addressed the issue of ethics and industry in an academic
setting. Using a Delphi panel technique, they arrived at a definition of conflict
of interest, and 41 separate points of acceptable and unacceptable behavior
related to gifts, research awards, and funding of various activities. The
Academic Orthopaedic Society Delphi Committee also mailed 191 questionnaires (157
department chairpersons and 34 program directors) to 157 training programs. The
respective department chairpersons and program directors were asked to copy and
distribute the questionnaires to staff (faculty) and house officers (residents
and fellows) to complete anonymously and return them for collation. Ninety-one
programs (58%) responded. Three hundred and fifty-two questionnaires were
returned (237 from staff, 115 from house officers), each of which expressed
agreement or lack of agreement with the Delphi panel report using a Likert scale
technique. With only modest (and usually predictable) disagreement on certain
items, the final statements by the Delphi panel were supported strongly by the
survive results. The Academic Orthopaedic Society believes that the major points
arrived at by the panelists should serve as the basis for ethical guidelines in
the relation between academic orthopaedic institutions and industry.
PMID- 10693575
TI - Klein's surgical strike at Medicare.
PMID- 10693576
TI - Caveat lector: be wary of media reports about excessive Ritalin use in BC.
PMID- 10693577
TI - Putting together the pieces of the physician supply puzzle.
PMID- 10693578
TI - Putting together the pieces of the physician supply puzzle.
PMID- 10693579
TI - Putting together the pieces of the physician supply puzzle.
PMID- 10693580
TI - Putting together the pieces of the physician supply puzzle.
PMID- 10693581
TI - Putting together the pieces of the physician supply puzzle.
PMID- 10693582
TI - Putting together the pieces of the physician supply puzzle.
PMID- 10693583
TI - Putting together the pieces of the physician supply puzzle.
PMID- 10693584
TI - Improving management of depression.
PMID- 10693585
TI - The move away from fee-for-service care.
PMID- 10693586
TI - Assessing quality of care.
PMID- 10693587
TI - Prevalence of anemia among James Bay Cree infants of northern Quebec.
AB - BACKGROUND: Anemia is common among First Nation infants in Canada, often as a
result of iron deficiency, which places them at risk for psychomotor impairment.
Prevalence data are unavailable, and the risk factors are unknown. This study
assessed the prevalence of anemia and associated risk factors among 9-month-old
Cree infants in northern Quebec. METHODS: Between January 1995 and October 1998,
6 of 9 Cree villages in the James Bay region adopted a screening protocol for
anemia in 9-month-old infants. Cross-sectional data were obtained from medical
charts. The data for babies of very low birth weight and those with fever or
infection were excluded. Among the 386 babies whose hemoglobin concentration was
known, the type of milk consumed at the time of screening was known for 354.
Associations between hemoglobin concentration and mean cell volume at 9 months,
and milk type and weight gain since birth were analysed. RESULTS: The mean
hemoglobin concentration of the 386 infants was 114.1 (standard deviation [SD]
10.6) g/L. The prevalence of anemia was 31.9% (95% confidence interval [CI] 27.2%
36.7%) with a hemoglobin cutoff value of 110 g/L, 17.6% 95% CI 13.9%-21.7%) with
a cutoff value of 105 g/L, and 7.8% (95% CI 5.3%-10.9%) with a cutoff value of
100 g/L. Babies exclusively fed formula at 9 months had a higher mean hemoglobin
concentration (118.5 [SD 9.9] g/L) than those exclusively fed breast milk (109.9
[SD 10.0] g/L), cow's milk (112.5 [SD 10.1] g/L) or more than one type of milk
(112.0 [SD 10.8] g/L) (p < 0.05). Compared with formula, the odds ratio (OR) for
anemia was 7.9 (95% CI 3.4-18.2) for breast milk, 5.0 (95% CI 2.0-12.7) for cow's
milk and 5.2 (95% CI 1.9-14.6) for mixed milks. Infants fed formula and those fed
cow's milk had significantly greater weight gains since birth, by 724 g and 624 g
respectively, than breast-fed infants (p < 0.05). When milk type was controlled
for, weight gain since birth was significantly associated with the presence of
microcytic erythrocytes (OR comparing highest tertile of weight gain to lowest
tertile 2.9, 95% CI 1.2-6.6). INTERPRETATION: Iron-deficiency anemia is highly
prevalent among James Bay Cree infants. Measures to increase iron intake are
required.
PMID- 10693588
TI - Gay and lesbian physicians in training: a qualitative study.
AB - BACKGROUND: Gay and lesbian physicians in training face considerable challenges
as they become professionalized. Qualitative research is necessary to understand
the social and cultural factors that influence their medical training. In this
study we explored the significance of gay or lesbian identity on the experiences
of medical training using naturalistic methods of inquiry. METHODS: Semi
structured interviews, focus groups and an e-mail listserv were used to explore
professional and personal issues of importance to 29 gay and lesbian medical
students and residents in 4 Canadian cities. Data, time, method and investigator
triangulation were used to identify and corroborate emerging themes. The domains
explored included career choice, "coming out," becoming a doctor, the environment
and career implications. RESULTS: Gay or lesbian medical students and residents
experienced significant challenges. For all participants, sexual orientation had
an effect on their decisions to enter and remain in medicine. Once in training,
the safety of a variety of learning environments was of paramount importance, and
it affected subsequent decisions about identity disclosure, residency and career
path. Respondents' assessment of professional and personal risk was influenced by
the presence of identifiable supports, curricula inclusive of gay and lesbian
sexuality and health issues and effective policies censuring discrimination based
on sexual orientation. The need for training programs to be proactive in
acknowledging and supporting diversity was identified. INTERPRETATION:
Considerable energy and emotion are spent by gay and lesbian medical students and
residents navigating training programs, which may be, at best, indifferent and,
at worst, hostile.
PMID- 10693589
TI - Use of physical and chemical restraints in medical teaching units.
PMID- 10693590
TI - Breast-feeding and anemia: let's be careful.
PMID- 10693591
TI - Education of medical students and house staff to prevent hazardous occupational
exposure.
PMID- 10693592
TI - Equity in health.
PMID- 10693593
TI - Tuberculosis: 13. Control of the disease among aboriginal people in Canada.
PMID- 10693594
TI - Safrole in betel quid may be a risk factor for hepatocellular carcinoma: case
report.
PMID- 10693595
TI - The Internet and evidence-based decision-making: a needed synergy for efficient
knowledge management in health care.
PMID- 10693596
TI - Septic shock: treating more than just blood pressure.
PMID- 10693597
TI - The urea breath test for Helicobacter pylori infection: taking the wind out of
the sails of endoscopy.
PMID- 10693598
TI - Is 79 too old for a heart transplant?
PMID- 10693599
TI - Candy killed after complaints from mentally disabled Americans.
PMID- 10693600
TI - Drug costs surpass spending on physicians.
PMID- 10693601
TI - Management practices in dental schools: an overview.
PMID- 10693602
TI - Patient support services.
PMID- 10693603
TI - Health and financial records.
PMID- 10693604
TI - Support services and staff responsibilities.
PMID- 10693605
TI - Implications and future challenges.
PMID- 10693606
TI - Studies of surgical outcome after patellar tendinopathy: clinical significance of
methodological deficiencies and guidelines for future studies. Victorian
Institute of Sport Tendon Study Group.
AB - Patellar tendinopathy is often treated surgically after failure of conservative
treatment but clinical experience suggests that results are not uniformly
excellent. The aim of this review was to (i) identify the different surgical
techniques that have been reported and compare their success rates, and (ii)
critically assess the methodology of studies that have reported surgical
outcomes. Twenty-three papers and two abstracts were included in the review.
Surgical procedures were categorized and outcomes summarized. Using ten criteria,
an overall methodology score was derived for each paper. Criteria for which
scores were generally low (indicating methodological deficiency) concerned the
type of study, subject selection process and outcome measures. We found a
negative correlation between papers' reported success rates and overall
methodology scores (r= -0.57, P<0.01). There was a positive correlation between
year of publication and overall methodology score (r=0.68, P<0.001). We conclude
that study methodology may influence reported surgical outcome. We suggest
practical guidelines for improving study design in this area of clinical
research, as improved study design would provide clinicians with a more rigorous
evidence-base for treating patients who have recalcitrant patellar tendinopathy.
PMID- 10693607
TI - Effects on the foetus of exercise in pregnancy.
AB - Maternal training during pregnancy has been the subject for numerous
investigations lately, which are presented in this survey. No studies in human
beings have shown any negative effect of training on the embryogenesis. During
physical training a small rise in foetal heart rate of 5-25 bpm is a common
finding. This could be due to a reduction in oxygen delivery or more likely
stimulation from maternal vasoactive hormones or training-induced uterine
contractions. Foetal growth seems to be influenced by maternal activity, as some
investigations have found significantly bigger babies born by moderately trained
females compared to non-trained or heavily trained women. In the latter group the
reduction could be explained by a reduced neonatal fat mass. Increased maternal
temperature during training has not been found to lead to any foetal
abnormalities. The results indicate that moderate training during pregnancy can
be recommended with observance of simple directives.
PMID- 10693608
TI - Estrogen-dependent tensile properties of the rabbit knee medial collateral
ligament.
AB - The influence of oophorectomy or continuous administration of estradiol on the
tensile properties of the rabbit knee medial collateral ligament was
investigated. Young postpubertal female New Zealand white rabbits were either
oophorectomized or underwent a sham operation. The sham-operated animals received
in addition a daily dosage of 4 mg 17beta-estradiol. After 5 months the animals
were killed, and the material properties of the bone-ligament-bone complex in one
knee were determined using a material testing machine and video system, and
compared to non-treated control animals. There was no difference in elastic
modulus between the groups. However, the ligaments from low-dose estrogen-treated
animals had a smaller cross-sectional area and a higher ultimate tensile strength
than those from controls or oophorectomized rabbits (P<0.04-0.0003).
PMID- 10693609
TI - Left ventricular mass, geometry and filling in elite female and male endurance
athletes.
AB - We compared echocardiographic findings in female (n=30) and male (n=30) endurance
athletes to age-matched female (n=15) and male (n=15) sedentary controls. The
differences between athletes and controls were similar in both sexes; only left
ventricular (LV) mass and septum thickness differed slightly more in men than in
women (67% vs 55%, P=0.004, and 36% vs 30%, P=0.03, respectively). LV wall
thicknesses were in the normal range in all women, while four (13%) male athletes
exceeded 13 mm. In conclusion, the effects of endurance training on
echocardiographic findings appear to be quite similar in women and men. However,
in female athletes with an abnormally thick left ventricular wall a thorough
cardiac evaluation is indicated. This contrasts with male athletes, in whom LV
wall thicknesses of over 13 mm are a not uncommon finding.
PMID- 10693610
TI - Relationship between perceived readiness to run and physiological variables
during repeated 2000 m bouts in middle-distance runners.
AB - The aim of this study was to investigate how heart rate (HR) and blood lactate
(LA) concentrations are associated with perceived readiness ratings (PRR) to
begin a new run during recovery after four different intensity steady-state 2000
m runs in college-level male middle-distance runners (n=15). A typical 4x2000 m
run test with stepwise increasing speed was used on the indoor track (150 m lap).
A new PRR scale was administered at each minute of recovery. The scale ranges
from 1 to 5 points (from "not at all ready to begin" to "completely ready to
begin"). Blood LA concentrations were measured immediately after runs and in the
3rd min of recovery after the first and second runs. In case of the third and
fourth runs, blood LA was measured immediately after the runs and in the 3rd and
6th min of recovery. HR was recorded at the end of every minute of recovery.
Highly significant inverse relationships were revealed between PRR, blood LA
concentrations and HR during recovery (r>0.9 as a rule). After the third and the
fourth 2000 m runs, where intensity was higher than LA threshold, PRR increased
during 6 min up to 4.8+/-0.4 and 4.5+/-0.6, respectively, while HR fell below 120
beats x min(-1). However, blood LA concentration remained high. The reliability
of the new PRR scale (tested on four runners), during recovery was very high
(r=0.98). These results suggest that the PRR scale can be used by runners to
determine the optimal duration of resting intervals between runs.
PMID- 10693611
TI - The continuity of physical activity--a retrospective and prospective study among
older people.
AB - This study investigated the continuity of life-span physical activity by
examining the predictors of the maintenance of a high level of physical activity
over 8 years among subjects aged 65-84 years at the baseline, in 1988, in
Jyvaskyla, Finland. Age, education, marital status and chronic conditions and
past physical activity were studied at the baseline. In men and women, self
reported competitive sport participation from as early as 10-19 years of age was
a significant predictor for maintaining activity in old age. Also women's
participation in recreational sports at the age of 40-64 years predicted
activity. We concluded that past physical activity is strongly connected to
maintaining a high level of physical activity in old age regardless of chronic
conditions that may develop.
PMID- 10693612
TI - Marathon with cystic fibrosis and bilateral lung transplant.
AB - The article presents studies performed before, during and after a marathon run
(42,195 m) in a 32-year-old man who underwent a bilateral lung transplantation
because of end-stage cystic fibrosis (CF) 15 months prior to the race. Before the
run his FEV1 was 81% predicted, compared with 19% predicted before the operation,
and his maximal oxygen uptake was 31.9 ml/kg(-1)/min(-1). He completed the New
York City Marathon 1998 without major problems in 7 h 8 min 50s. Pulmonary tests,
biochemical changes and endocrine responses indicated transient changes, mostly
as expected in healthy marathon runners. The case demonstrates that physiological
trainability and psychological will power following a successful bilateral lung
transplantation can transform a chronically ill CF patient into a robust marathon
runner.
PMID- 10693613
TI - Comparison between in-line and rollerskating injury. A prospective study.
AB - Rollerskating is an activity that has become increasingly popular over the past
several years among children and adults in Denmark. During a 7-month period in
1997, 300 in-line skaters and 107 roller skaters were treated in the Emergency
Department, Esbjerg County Hospital. Of these, 60.4% had minor injuries (sprains,
bruises, lacerations) and 39.6% fractures. There was no statistical significant
difference in the types of injury between skater groups. The most common serious
injury was fracture of the wrist, which occurred in both skater groups (25%,
n=102). Almost all of the fractures of the wrist and elbow occurred among skaters
who did not wear wrist or elbow guards Only 20% of the skaters used protective
equipment. In-line skaters used protective equipment more often than did roller
skaters. Of all accidents, 69% occurred on public roads (street and sidewalk).
PMID- 10693614
TI - A comparison of the STAI and CSAI-2 in five-day recalls of precompetition anxiety
in collegiate track and field athletes.
PMID- 10693615
TI - Topography-controlled excimer laser photorefractive keratectomy.
AB - PURPOSE: To assess whether photorefractive keratectomy (PRK) controlled by
videokeratography can successfully treat refractive errors in eyes with corneal
irregularities and improve spectacle-corrected visual acuity. METHODS: In a
prospective clinical study, PRK was performed in 10 eyes of 10 patients. Reason
for surgery was irregular astigmatism after penetrating keratoplasty, corneal
irregularity after corneal scarring, corneal astigmatism in keratoconus, and
decentration after myopic and hyperopic PRK. Excimer ablation was controlled by
preoperative videokeratography (Orbscan II, Orbtek) using the MEL-70 system from
Aesculap Meditec. Follow-up was 6 months. RESULTS: Concerning manifest
refraction, the sphere was reduced on average from +1.92 to +0.57 D, 6 months
postoperatively. Cylinder changed from -1.95 D on average to -0.30 D at 6 months
postoperatively. There was improvement of uncorrected visual acuity of 2 or more
lines in 5 eyes and no change in 5 eyes 6 months postoperatively. Spectacle
corrected visual acuity improved in 2 eyes by 2 to 3 lines, in 9 eyes by 1 to 3
lines, and showed no change in 1 eye. CONCLUSION: Videokeratography-controlled
PRK improved refractive errors in irregular corneas with improvement of spectacle
corrected visual acuity.
PMID- 10693616
TI - Corneal lathing using the excimer laser and a computer-controlled positioning
system.
AB - PURPOSE: To present the excimer laser corneal shaping system (ELCS-S), an add-on
device to the Keratom, a commercially available 193-nm excimer laser built by
Schwind. METHODS: The system is designed for the preparation of donor corneas
under sterile conditions using the ultraviolet laser to offer greatest possible
flexibility. Lenticules for planolamellar grafting and refractive
epikeratoplasty, as well as donor buttons for penetrating keratoplasty can be
computer-designed by the surgeon or technician and lathed with the system.
RESULTS: Using the excimer laser corneal shaping system (ELCS-S) on human donor
corneas, the central surface of the epikeratoplasty lenticule exhibited only
narrow, flat concentric notches corresponding to the single lathing steps.
Transmission electron microscopy revealed a damage zone of less than 0.3 microm
in close approximation to the treated surface. The final thickness revealed a
difference of less than +/-53 microm from the intended, initially programmed
value. Ultrastructural studies showed the perpendicular stromal surface of the
penetrating keratoplasty buttons to be smooth with minimal protrusion of
Descemet's membrane. Endothelial injury was observed in a zone averaging between
40 and 100 microm adjacent to the cutting edge only. CONCLUSION: The excimer
laser corneal shaping system (ELCS-S) allows a computer-controlled, surgeon
designed, sterile preparation of lamellar and penetrating corneal grafts with the
use of the excimer laser. This could offer significant advantages in comparison
to presently available systems for lamellar dissection and trephination.
PMID- 10693617
TI - Healing after photorefractive keratectomy in cat eyes with a scanning mid
infrared Nd:YAG pumped optical parametric oscillator laser.
AB - PURPOSE: To evaluate the healing characteristics of cat corneas treated with a
new scanning mid-infrared laser system. METHODS: Six adult cats were treated with
6-mm diameter photorefractive keratectomy (PRK) corrections. One eye in each
animal was untreated as a control and the other was treated with either a -3.00
or -6.00 diopter ablation. The laser was a new Nd:YAG pumped optical parametric
oscillator laser at 2.94 microm with a new scanning delivery system. The pulse
width was 7 nanoseconds, the repetition rate was 10 Hz, the size of the laser
spot on the eye was 1.0 mm, and the fluence was 150 mJ/cm2. Healing of the cat
corneas was followed for 4 months. Slit-lamp and corneal topography evaluations
were done at each follow-up examination. Histology was performed at the end of
the study. RESULTS: The corneal epithelium healed within 1 week. There was no
stromal haze in any eye after the epithelium healed. After the first 2 weeks,
slit-lamp examination could not identify which eye was treated. Corneal
topography showed corneal flattening. Light microscopy at 4 months revealed
normal epithelium and increased keratocyte density in the anterior third of the
cornea. Electron microscopy showed discontinuities in the basement membrane and
hemidesmosomes. The deep stroma and endothelium were normal. CONCLUSIONS: Cat
corneas treated with the new optical parametric oscillator laser healed normally
with no adverse effects. Increased keratocyte activity in the anterior stroma was
the only noticeable response besides the flattening shown by topography.
PMID- 10693618
TI - Histological comparison of corneal ablation with Er:YAG laser, Nd:YAG optical
parametric oscillator, and excimer laser.
AB - PURPOSE: To use histological techniques to assess and compare the ablation depth,
local damage, and surface quality of corneal ablations by a Q-switched Er:YAG
laser, an optical parametric oscillator laser at 2.94 microm, a long pulse Er:YAG
laser, and a 193-nm excimer laser. METHODS: Human cadaver eyes and in vivo cat
eyes were treated with a 6.0-mm diameter, 30-microm-deep phototherapeutic
keratectomy ablation and a 6.0-mm diameter, -5.00-D photorefractive keratectomy
ablation. Human cadaver eyes were also treated with a 5.0-mm diameter, -5.00-D
laser in situ keratomileusis (LASIK) ablation. Fluences and pulse widths used
were 200 mJ/cm2 and 70 ns for the Q-switched Er:YAG, 150 mJ/cm2 and 7 ns for the
optical parametric oscillator laser (OPO), 500 mJ/cm2 and 50 microseconds for the
long pulse Er:YAG, and 160 mj/cm2 and 20 ns for the excimer laser. In the
ablation rate study, 12 porcine eyes were ablated by the OPO laser with a range
of layers and at different fluences ranging from 60 to 150 mJ/cm2, all using a
1.5-mm spot on the eye. The ablation depth of these acute ablations was evaluated
by light microscopy examination. RESULTS: In the acute damage study, light
microscopy showed a thin surface layer in all samples with minimal thermal damage
except on the long pulse Er:YAG corneas. Transmission electron microscopy
revealed less than 0.3-microm surface damage for all specimens of both the
optical parametric oscillator and the excimer laser samples with no evidence of
collagen shrinkage. Transmission electron microscopy showed damage layers of 0.5
to 3 microm for Q-switched Er:YAG and 3 to 10 microm for long pulse Er:YAG.
Scanning electron microscopy showed smooth surfaces in all eyes, although the
excimer was the roughest. In the porcine eye study, ablations were produced in
both PTK and PRK modes with the ablation rate per layer increasing with the
fluence. At 120 mJ/cm2, the average ablation rate was 1.9 microm per layer.
CONCLUSIONS: The histology from the short pulse mid-infrared optical parametric
oscillator laser at 2.94 microm was comparable to the 193-nm excimer with a
smooth, damage-free, ablation zone when performing PRK and LASIK.
PMID- 10693619
TI - Limitations of erbium:YAG laser photorefractive keratectomy.
AB - PURPOSE: The erbium:YAG laser (lambda = 2.94 microm) has been considered
promising as an alternative to the ArF excimer laser in photorefractive
keratectomy (PRK). However, corneal application of this mid-infrared solid state
laser is still plagued with various disadvantages compared to that of the ArF
excimer laser (lambda = 193 nm). We discuss the limitations of PRK with the
erbium:YAG laser. METHODS: Measurements of ablation threshold, ablation
efficiency, and thermal damage were done to compare the process of erbium:YAG
laser photoevaporization to the ArF excimer laser. PRK procedures were performed
on fresh enucleated pig corneas to investigate the morphology and surface
roughness of the cornea after scanning-spot and fundamental mode photoablation.
Surface roughness was measured by using a tactile surface reprofiling system.
RESULTS: The ablation threshold and the ablation efficiencies for the erbium:YAG
laser are significantly higher compared to the ArF excimer laser. Collateral
thermal damage decreases with a reduction of laser pulse duration to a minimum of
approximately 5 microm. Scanning electron microscopy and surface roughness
measurements of the corneal surface after erbium:YAG laser treatment demonstrated
higher surface roughness compared to ArF excimer laser treatments. CONCLUSIONS:
The erbium:YAG laser is not at present an alternative to the ArF excimer laser
for photorefractive keratectomy.
PMID- 10693620
TI - Arcuate transverse keratotomy remains a useful adjunct to correct astigmatism in
conjunction with photorefractive keratectomy.
AB - PURPOSE: To retrospectively evaluate the effectiveness of paired, arcuate
transverse keratotomy (Arc-T) performed prior to or after photorefractive
keratectomy (PRK) to correct low to moderate amounts of natural or laser-induced
astigmatism. METHODS: Spherical PRK was performed in 730 eyes for myopia of -1.00
to -7.00 D. PRK with arcuate transverse keratotomy was performed in 150 of these
eyes; we studied 123 eyes that did not have PRK enhancement. Arc-T was performed
prior to PRK in all 37 study eyes with astigmatism of 1.50 D or more at the
preoperative examination. Arc-T keratotomy was performed after PRK in 86 study
eyes for residual astigmatism of +0.75 D or more and uncorrected visual acuity of
20/30 or worse. RESULTS: Arc-T before PRK group: PRK was performed at a mean 1.0
+/- 1.5 months after Arc-T. Mean astigmatism decreased from +2.40 +/- 0.6 D
(range, 1.00 to 4.00 D) before Arc-T to 0.60 +/- 0.60 D (range, 0 to 2.25 D)
after Arc-T (P < .0001). Net change in astigmatism was 1.80 +/- 0.60 D (range,
0.80 to 2.80 D) and mean reduction was 75%. Spherical equivalent refraction
changed from -4.10 +/- 1.90 D (range, -0.25 to -8.10 D) to -4.40 +/- 1.80 D after
Arc-T (P = .002). Mean change in spherical equivalent refraction after Arc-T was
0.30 +/- 0.50 D (range, -1.10 to +0.40 D). Arc-T after PRK group: Arc-T was
performed at a mean 3.5 +/- 1.9 months after PRK. Six months after Arc-T,
astigmatism was decreased from +1.50 +/- 0.60 D to 0.40 +/- 0.40 D (P = .04). Net
change in astigmatism at 6 months was 1.10 +/- 0.60 D and mean reduction was 74%.
Vector change in astigmatism magnitude was 1.30 +/- 0.60 D (range, 0 to 4.00 D)
at 6 months and vector change in astigmatism axis was 65 degrees +/- 68 degrees.
Spherical equivalent refraction did not change when Arc-T was performed after PRK
for eyes with low astigmatism (P = .4). Arc-T retreatment was performed in 6 of
37 (16%) eyes that had Arc-T before PRK and 18 of 86 (21%) eyes that had Arc-T
after PRK (P = .12). CONCLUSION: Arcuate transverse keratotomy performed prior to
PRK for high astigmatism or after PRK for lower levels of residual astigmatism
effectively improved visual outcome. Coupling was less predictable for high
levels of astigmatism correction with Arc-T.
PMID- 10693621
TI - Relative mydriasis after photorefractive keratectomy.
AB - PURPOSE: To report the incidence of anisocoria after unilateral excimer laser
photorefractive keratectomy (PRK) for myopia and subsequent corticosteroid
therapy in a retrospective and prospective study and to explore possible
etiologies. METHODS: The horizontal pupil diameter was determined in 6 patients
(6 eyes) at 21.8 +/- 12.6 months after unilateral wide-field excimer laser PRK
(retrospective group) as well as in 8 consecutive patients (8 eyes) before and
3.4 +/- 2.9 months after unilateral PRK (prospective group). The Schwind-Keratom
wide-field excimer laser was used. Measurements were done in an examination room
using Rosenbaum card comparison pupillometry and with a Goldmann perimeter at
31.5 asb. In the prospective group, the effect of fitting a hard contact lens of
zero diopter power and the application of 0.1% pilocarpine were evaluated.
RESULTS: Relative mydriasis was present in all treated eyes and the difference in
pupil diameter between the two eyes measured 0.25 to 1.75 mm (retrospective
group: +0.56 +/- 0.82 mm; prospective group: +0.72 +/- 0.29 mm). At the time of
pupil measurement, the retrospective group had a significantly longer mean
postoperative follow-up (21 mo) than the prospective group (3.4 mo) and
significantly more eyes still received topical corticosteroid treatment
(retrospective group, 1 of 6 eyes; prospective group, 7 of 8 eyes). The amount of
anisocoria did not correlate with the applied laser energy, ablation depth, or
refractive change, but showed a negative correlation with increasing time after
PRK. Neither hard contact lens fitting nor pilocarpine 0.1% reduced the amount of
anisocoria significantly. CONCLUSION: Unilateral PRK with wide-field excimer
laser ablation and subsequent application of topical corticosteroids regularly
resulted in a relative pupillary mydriasis. Neither an altered corneal profile
nor parasympathetic denervation is responsible for this. Weakening of the
pupillary sphincter of the treated eye may cause this phenomenon.
PMID- 10693622
TI - Photorefractive keratectomy for visual rehabilitation of anisometropia induced by
retinal detachment surgery.
AB - PURPOSE: To evaluate the efficacy of unilateral photorefractive keratectomy to
correct anisometropia induced by retinal detachment surgery. METHODS:
Photorefractive keratectomy was performed in 10 eyes of 10 patients with
anisometropia induced by previous retinal detachment surgery. The Aesculap
Meditec MEL 60 excimer laser was used. RESULTS: Preoperative mean spherical
equivalent refraction was -5.20 D. Mean postoperative spherical equivalent
refraction was -0.25 D after a mean follow-up of 12.9 months. Mean preoperative
spherical equivalent refraction difference between two eyes of 4.87 D was
decreased to a mean 0.60 D postoperatively (t-test, P < .0001). All patients were
free of anisometropic symptoms after laser surgery. CONCLUSION: Unilateral
photorefractive keratectomy seems to be an effective method to correct
anisometropia induced by conventional retinal detachment surgery, especially for
patients with spectacle and contact lens intolerance.
PMID- 10693623
TI - Lower intraoperative flap complication rate with the Hansatome microkeratome
compared to the Automated Corneal Shaper.
AB - PURPOSE: The purpose of this study was to retrospectively compare the incidence
of intraoperative flap complications, such as partial flaps, donut-shaped flaps,
central corneal cuts, and complete caps with the Hansatome and Automated Corneal
Shaper (ACS) microkeratomes. METHODS: All laser in situ keratomileusis (LASIK)
procedures performed by a single surgeon with the Hansatome or Automated Corneal
Shaper in which intraocular pressure was verified with a pneumotonometer were
reviewed. RESULTS: A total of 90 eyes had LASIK with the ACS microkeratome. Six
of the ACS eyes (6.7%) had intraoperative flap complications (4 partial flaps, 1
donut-shaped flap, 0 central corneal cuts, 1 complete cap). Partial flaps and
donut-shaped flaps were replaced without laser application and the procedure
repeated 2 to 3 months later. Two of these eyes lost 2 lines and one lost 1 line
of spectacle-corrected visual acuity at 6 months after repeat LASIK. The eye with
the donut-shaped flap was treated with transepithelial photorefractive
keratectomy (PRK) and had no change in spectacle-corrected visual acuity at 6
months after PRK. The eye with the complete cap had no change in spectacle
corrected visual acuity after laser ablation. Five hundred ninety-eight (598)
eyes had LASIK with the Hansatome microkeratome. Two of the Hansatome eyes (0.3%)
had a flap complication (1 partial flap and 1 donut-shaped flap). The first eye
retained spectacle-corrected visual acuity at 6 months after repeat LASIK. The
second eye had transepithelial PRK to eliminate the donut shaped flap with no
loss of spectacle-corrected visual acuity at 6 months after surgery. The
difference in flap complications between the two procedures was statistically
significant (P < .01). There were no flap displacements following surgery in
either group. CONCLUSION: Intraoperative flap complications are less likely to
occur with the Hansatome microkeratome than with the ACS microkeratome.
PMID- 10693624
TI - Evaluation of corneal flap dimensions and cut quality using the Automated Corneal
Shaper microkeratome.
AB - PURPOSE: To evaluate flap dimensions and cut deterioration with repeated blade
use in an automated microkeratome. METHODS: The Automated Corneal Shaper (Chiron
Adatomed, Munich, Germany), 160-microm plate attached, was used to make a corneal
flap in 90 pig cadaver eyes, reusing blades up to five times. Flap diameter was
measured by planimetry and thickness was calculated by ultrasound pachymetry.
Scanning electron microscopy of stromal beds and blade cutting edges was
performed to assess cut deterioration after repeated blade use. RESULTS: Mean
flap central thickness was 125 +/- 32 microm. Mean vertical flap diameter was 7.6
+/- 0.4 mm. No correlation was found between thickness and diameter (r = 0.15, P
= .45). Progressive thinning of the flap was observed in the direction of the
flap hinge. Smooth cuts (using new blades) with periodic chatter lines at the
keratectomy edge and in the stromal bed were observed with scanning electron
microscopy. Increasing tissue remnants on the stromal bed and decreasing cut
quality occurred with repeated blade use. Blades showed larger tissue remnants,
nicks, and even folds on the cutting edge proportional to the number of times
blades were used. CONCLUSION: Satisfactory cut quality and reproducibility were
obtained after a single use of stainless steel blades in the Automated Corneal
Shaper microkeratome. Cut quality was degraded dramatically by repeated use of
blades.
PMID- 10693625
TI - Photospallation: a new theory and mechanism for mid-infrared corneal ablations.
AB - PURPOSE: A new mechanism for ablating corneal tissue is proposed, based on
photospallation with short pulse mid-infrared (IR) laser radiation. METHODS: By
using a judicious combination of high absorption, short pulses, and low fluences,
ablation with this process can potentially remove tissue in a highly localized
manner with submicron collateral thermal damage characteristics similar to those
achieved by excimer lasers. We provide a brief qualitative overview of aspects of
the spallation process that distinguish it from the more familiar photoablation
and photothermal mechanisms. RESULTS: Results of preliminary parametric analysis
based on one-dimensional models of thermoelastic expansion are summarized.
CONCLUSION: These preliminary calculations lend support to the conjecture that
corneal tissue can be removed effectively with strongly absorbed nanosecond
pulses from a mid-IR laser, using operational fluence levels of less than 200
mJ/cm2.
PMID- 10693626
TI - Eggink wins 1999 Troutman Award.
PMID- 10693627
TI - Central nervous system complications in liver transplant recipients--incidence,
timing, and long-term follow-up.
AB - BACKGROUND: Neurological impairment is a major source of morbidity and mortality
following orthotopic liver transplantation (OLT). We reviewed our experience with
neurologic complications among our first 463 consecutive adult OLT recipients.
METHODS: Between September 1988 and October 1993, 463 adult patients underwent
OLT. Data on incidence, time of onset, and outcome of central nervous system
(CNS) complications was obtained from patient charts, including autopsy results
when available. CNS complications were classified by clinical presentation and by
etiology. RESULTS: 93 patients (20.1%) had CNS complications following OLT.
Encephalopathy (11.8%) and seizure (8.2%) were the leading complications. The
incidence of immunosuppressive drug-related complications was 5.6%; coma, 1.7%;
cerebral hemorrhage, 1.5%; central pontine myelinolysis (CPM), 1.2%; stroke,
0.6%; and primary CNS lymphoma, 0.2%. Most CNS events (80%) were encountered in
the first month after OLT. In the majority of cases, encephalopathy (70%) and
seizure (50%) presented in the first 2 wk. Although most CNS infections occurred
early, 2 patients developed tuberculous meningitis more than 1 yr post-OLT. In 12
patients, death was directly related to CNS complications (2.6%). CONCLUSIONS:
Most CNS complications occur early following OLT but may be seen even after 1 yr.
Patients may survive serious neurologic events, such as cerebral hemorrhage, CPM,
and meningitis.
PMID- 10693628
TI - Pulmonary Rhizopus infection in a diabetic renal transplant recipient.
AB - Infectious complications after renal transplantation remain a major cause of
morbidity and mortality. Mucormycosis is a rare infection in renal transplant
recipients; however, mortality is exceedingly high. Risk factors predisposing to
this disease include prolonged neutropenia, diabetes, and patients who are
immunosuppressed (Singh N, Gayowski T, Singh J, Yu LV. Invasive gastrointestinal
zygomycosis in a liver transplant recipient: case report and review of
zygomycosis in solid-organ transplant recipients, Clin Infect Dis 1995: 20: 617).
Life-threatening infections can occur, as this fungus has the propensity to
invade blood vessel endothelium, resulting in hematological dissemination. We
report a case of cavitary Rhizopus lung infection, 2 months after renal
transplantation, where the patient was treated successfully with Amphotericin B
and surgical resection of the lesions with preservation of his allograft
function. In this era of intensified immunosuppression, we may see an increased
incidence of mucormycosis in transplant population. Invasive diagnostic work-up
is mandatory in case of suspicion; Amphotericin B and, in selected cases,
surgical resection are the mainstays of therapy.
PMID- 10693629
TI - Iliac artery stenosis masquerading as diuretic resistant congestive heart
failure.
AB - Iliac artery stenosis is a rare cause of renal dysfunction in renal allograft
recipients. Its presence can mimic renovascular hypertension and yet alter the
very radiologic tests used to diagnose renal artery stenosis. We investigate a
case of iliac artery stenosis that presented with diuretic resistant fluid
overload, hypertension and limb claudication that exposed the pitfalls in the
diagnosis and management of this condition. Successful stent placement, 8 months
after transplant, resulted in return of the serum creatinine below the post
transplant nadir.
PMID- 10693630
TI - Influence of anti-rejection therapy on the timing of cytomegalovirus disease and
other infections in renal transplant recipients.
AB - Infections are an important cause of mortality and morbidity in renal transplant
recipients. To study the impact of anti-rejection therapy on the timing of
infections, the records of 599 consecutive renal transplants, performed prior to
31 December 1996 at the Royal Melbourne Hospital, were reviewed. Patients were
grouped according to acute rejection (AR) episode and treatment during the first
6 months after transplantation. Group 1 [n = 168 (35%)] patients did not
experience any episode of AR. Group 2 [n = 169 (35%)] patients had one or more
episodes of AR and received high doses of steroids. Group 3 [n = 141 (30%)]
patients had more than one episode of AR and received anti-lymphocyte antibodies
in addition to high doses of steroids. Infections were more common in Groups 2
and 3 but only cytomegalovirus (CMV) disease occurred earlier in patients treated
with lympholytics. Given the high incidence and early onset of CMV disease in
patients receiving lympholytics and considering that an effective prophylactic
protocol remains undetermined, pre-emptive treatment with ganciclovir in this
high risk group appears justified.
PMID- 10693632
TI - Commerce in transplantation: how does it affect European legislation?
AB - Commerce in transplantation is well known, if not well defined. Although the word
commerce suggests an exchange of money, in reality it often simply signifies a
non-profit-making transaction. Nevertheless, money, and therefore profit, may be
involved in some human organ transactions, and the buying and selling of organs
for transplantation remains common in too many countries. Clearly, if such
transactions were allowed to continue only those who could afford to pay would
benefit. They would probably also lead to an increase in the number of media
horror stories. A number of such stories have appeared in the past. Although they
are rarely based on hard evidence, they do influence politicians and, as a
consequence, affect legislation and the availability of organs for transplant.
They may also diminish the willingness of the general public to become organ
donors and contribute to the persistent poor supply of organ donors. Organ
exchange organizations, such as Eurotransplant, have made many efforts to prevent
unethical transactions. Nevertheless, stories of such transactions continue to
appear and are unlikely to abate while there is a high demand and poor supply of
organs for transplantation. An international donor surveillance committee--a
clearing house for information on malpractice--could be one solution to the
problem as it would prevent doctors from taking part in unethical transplant
procedures.
PMID- 10693631
TI - Cytomegalovirus immune globulin after liver transplantation: a cost-effectiveness
analysis.
AB - OBJECTIVE: Cytomegalovirus (CMV) immune globulin (CMVIG) has been shown to
significantly reduce severe CMV-associated disease complicating orthotopic liver
transplant (OLT). We evaluated the economic impact of severe CMV-associated
disease and calculated the marginal cost-effectiveness (C/E) of routine
prophylaxis with CMVIG after OLT. DESIGN: C/E analysis. SETTING: Four teaching
hospitals in Boston. PATIENTS: Patients who underwent OLT from January 1988
through June 1990. MEASUREMENTS: We gathered actual cost data of hospital care
for patients enrolled in a clinical trial of CMVIG prophylaxis in OLT. We
calculated average outpatient expenses from a separate group of patients
undergoing OLT and developed a regression model to estimate costs during the
first year post-transplant (R2 = 0.77). Based on this model, we calculated
variable costs (in 1999 US dollars) for all patients in the randomized trial.
From the published literature we obtained the probability of CMV outcomes and of
long-term survival after OLT. We then developed a decision analytical model to
determine an incremental C/E ratio, using a Markov simulation to estimate long
term survival and long-term costs. We discounted costs and life-years at 3% and
5% per yr. RESULTS: Based on the efficacy rate of 54% in the controlled trial, we
estimate that CMVIG will increase life expectancy by 0.65 discounted years at an
additional cost of $11,600, providing a marginal C/E ratio of $17,900/yr life
saved. Examining the confidence limits of efficacy, we estimate that CMVIG will
have a marginal C/E ratio of $66,200 gained/yr at an efficacy of 11% and $14,000
gained/yr at an efficacy of 83%. CONCLUSION: After OLT, prophylactic CMVIG has an
incremental C/E ratio comparable to that of other well-accepted medical therapies
and should be used routinely in these patients.
PMID- 10693633
TI - Delphi-panel analysis of appropriateness of high-dose chemotherapy and blood cell
or bone marrow autotransplants in women with breast cancer.
AB - BACKGROUND: There is controversy whether high-dose chemotherapy and a blood cell
or bone marrow autotransplant is a better treatment than conventional-dose
chemotherapy for women with local/regional or metastatic breast cancer. Subject
selection and time-to-treatment biases make definitive comparison impossible.
Recent results of randomized trials are contradictory. OBJECTIVE: Determine
appropriateness of high-dose chemotherapy and a blood cell or bone marrow
autotransplant in women with breast cancer. PANELISTS: Nine breast cancer experts
from diverse geographic sites and practice settings. EVIDENCE: Boolean MEDLINE
searches of 'breast cancer' and 'chemotherapy' and/or 'blood cell' or 'bone
marrow transplants'. PROCESS: We used a modified Delphi-panel group judgement
process. Clinical variables were permuted to define 2058 clinical settings. Each
panelist rated appropriateness of high-dose therapy and an autotransplant versus
conventional therapy on a 9-point ordinal scale (1: most inappropriate, 9: most
appropriate). An appropriateness index was developed based on median rating and
amount of disagreement. The relationship of appropriateness indices to the
permuted clinical variables was considered by analysis of variance and recursive
partitioning. CONCLUSIONS: In women with local/regional breast cancer
autotransplants were rated: 1) appropriate in those with > or = 10 cancer
involved lymph nodes; 2) uncertain in those with 4-9 cancer-involved nodes; and
3) inappropriate in women with < or = 3 cancer-involved lymph nodes. In women
with metastatic breast cancer autotransplants were rated: 1) appropriate in those
with metastases to 'favorable' sites (skin, lymph node, pleura) and a complete or
partial response to chemotherapy; 2) uncertain in women with metastases to
'unfavorable' sites (lung, liver, or central nervous system) and a complete
response to chemotherapy or those with bone metastases and a complete or partial
response or stable disease after chemotherapy; and 3) inappropriate in other
settings.
PMID- 10693634
TI - Preliminary experience with midodrine in kidney/pancreas transplant patients with
orthostatic hypotension.
AB - In an effort to ameliorate the problem of orthostatic hypotension in pancreas
transplant patients, current medical management consists of maximizing the
patient's hydration, altering antihypertensives, increasing sodium intake,
initiation of fludrocortisone, compression stockings, and behavioral
modifications. Despite these medical interventions, a subset of patients remains
symptomatic. Midodrine (ProAmatine), an alpha-adrenergic agonist, was approved
for the treatment of symptomatic orthostatic hypotension in the US. This
preliminary report attempts to assess the safety and efficacy of midodrine use in
kidney/pancreas (KP) or pancreas alone (PA) transplant recipients. A
retrospective review was performed of 7 KP and 1 PA recipient experiencing
symptomatic postural hypotension after maximizing other medical treatments. Blood
pressure, serum creatinine (SrCr), and objective responses to postural
hypotension were assessed at routine intervals. Pre-midodrine monitoring revealed
a mean orthostatic change in systolic blood pressure from sitting to standing of
43 mmHg (range 20-100 mmHg). Patients received a mean starting midodrine dose of
18 mg/d, which was titrated to a maximum dose of 30 mg/d. Systolic blood pressure
monitoring revealed a mean orthostatic change of 27 mmHg (range 0-81 mmHg) after
initiation of treatment with midodrine and a mean follow-up of 3.2 months. All
study patients reported improvement in symptoms of orthostatic hypotension. SrCr
was not affected based upon comparison of pre-treatment and current SrCr values
of 1.4 and 1.3 mg/dL, respectively. The most common side effect experienced was
supine hypertension. These preliminary results suggest that midodrine is safe and
effective in transplant recipients; however, the dosage should be titrated to
symptomatic relief or a maximum dose of 30 mg. Careful monitoring for supine
hypertension is necessary.
PMID- 10693635
TI - Quality of life in long-term survivors after liver transplantation: impact of
recurrent viral hepatitis C virus hepatitis.
AB - Post liver transplant recurrence of infection with hepatitis C virus (HCV) occurs
in approximately 50% of patients transplanted because of HCV-related liver
disease. The aim of this study was to assess long-term quality of life,
psychologic distress, and coping in patients with recurrent HCV after liver
transplantation in comparison to patients transplanted for other etiologies of
underlying liver disease. All liver transplant recipients transplanted at a
University affiliated Veterans Affairs Medical Center who had greater than 6
months follow-up were sent a questionnaire investigating quality of life
(assessed by Medical Outcomes study health survey SF-36), depression (assessed by
Beck Depression Inventory), total mood disturbance (assessed by Profile of Mood
States scale), coping (assessed by Billing and Moos Inventory of coping with
illnesses), and employment status. Lower Beck Depression Inventory score (p =
0.001), lower mood disturbance score (p = 0.0001), overall satisfaction with
present work (p = 0.0001), and lesser use of avoidant coping (p = 0.06) were
predictors of better quality of life in long-term survivors of liver
transplantation. At a mean follow-up of 4 yr after liver transplantation,
patients with histopathologically diagnosed recurrent viral HCV hepatitis had
significantly lower global quality of life score (mean score of 76.4 versus 86.2,
p = 0.011) and physical functioning score (mean score 20 versus 25, p = 0.015),
as compared to all other patients. In summary, quality of life and physical
functioning were significantly impaired in liver transplant recipients with
histopathologically diagnosed recurrent HCV hepatitis, as compared to those whose
HCV hepatitis had not recurred or those transplanted for other reasons.
PMID- 10693636
TI - Infusion of donor spleen cells and rejection in liver transplant recipients.
AB - Intact or inactivated donor lymphoid cells have been found to downregulate the
alloimmune response in a number of experimental models. We conducted a
randomized, prospective, double blind, and placebo-controlled trial to determine
whether heat-treated donor spleen cells would affect early rejection after liver
transplantation. Donor spleen was obtained during organ procurement for 40
patients undergoing liver transplantation. All patients were treated with
cyclosporine, azathioprine and steroids. The patients were randomized after
surgery to receive either heat-treated (45 degrees C for 1 h) spleen cells or
placebo. Patients underwent protocol biopsies at 1 wk, 4 and 12 months, or as
needed. Biopsies were reviewed in a blind fashion and scored according to the
Banff consensus criteria. Randomization resulted in 19 patients in the spleen
cell group and 21 in the placebo group. One-yr graft survival was 94 and 100%,
respectively. Early rejection was more frequent in the spleen cell group (61 vs.
35%, p, not significant). The histopathological rejection activity index at 7 d
was also higher for the patients in the spleen cell group: 39% of spleen cell
treated patients had a score of 4 or higher as opposed to 5% in the placebo group
(p < 0.01). The mean score was 2.9 +/- 2.8 for the spleen cell group versus 1.3 +
1.7 for the placebo group (p = 0.034). It is concluded that heat-treated donor
spleen cells given within 24 h after liver transplantation were not clinically
beneficial and increased the intensity of rejection in 7-d protocol liver
biopsies.
PMID- 10693637
TI - Immunization of renal transplant recipients with pneumococcal polysaccharide
vaccine.
AB - BACKGROUND: Streptococcus pneumoniae, a common pathogen leading to pneumonia, is
a cause of morbidity and mortality in immunosuppressed patients. Vaccination
against this agent can be recommended for immunosuppressed patients, including
those with chronic renal failure, nephrotic syndrome and renal transplant
recipients; however, a diminished immune response and loss of protective
antibodies have been observed. PATIENTS AND METHODS: In our prospective study,
the efficacy and side effects of polyvalent pneumococcal vaccination were
investigated in renal transplant recipients. A total of 21 patients (6 female, 15
male) with well-functioning renal allografts, who had transplant surgery at least
2 months before, were included in the study. The patients were stratified
according to the immunosuppressive protocol and 8 received double, while 13
received triple, immunosuppressive agents. After obtaining basal serum samples,
all cases were vaccinated with the 0.5 mL intramuscular administration of
polyvalent polysaccharide pneumococcal vaccine (Pneumo 23 Pasteur Merieux, lot
No: K 1131). RESULTS: Following a mean of 6 wk in all patients and also a mean of
12 wk in 12 patients, serum samples were again obtained to measure pneumococcal
antibodies. Antibody titers following 6 and 12 wk of vaccination were
significantly higher, as compared with basal values in all patients, except one.
These titers did not show any statistically significant difference between double
and triple therapies. There was no significant difference between the 12th and
6th wk postvaccination antibody titers. No systemic or local adverse effects were
observed. CONCLUSION: Pneumococcal vaccination is safe and effective in patients
with well-functioning renal allografts, at least in the short term. This
vaccination policy may be useful for preventing invasive pneumococcal disease in
immunosuppressed patients.
PMID- 10693638
TI - A longitudinal study of TGF-beta1 protein levels in renal allograft recipients
converted from CsA to MMF or AZA.
AB - Cyclosporine (CsA) is thought to enhance transforming growth factor (TGF)-beta1
production in vitro and in vivo and this may have a negative effect on long-term
graft survival. Therefore, we studied TGF-beta1, plasma levels in 30 patients
before kidney transplantation, after transplantation during CsA treatment and
after conversion from CsA to azathioprine (AZA) or mycophenolate mofetil (MMF).
We questioned whether TGF-beta1 plasma levels would decrease after the
discontinuation of CsA and whether the TGF-beta1 plasma levels did correlate with
CsA trough levels and kidney function, measured by serum creatinine levels. TGF
beta1 plasma levels measured 1 yr after transplantation were lower compared to
levels measured before transplantation, however not significantly (p = 0.08).
After conversion from CsA to MMF or AZA, a slight increase was observed in some
patients, but in the total group TGF-beta1 levels remained unaffected. No
correlation was found between the TGF-beta1 levels and CsA trough levels nor with
creatinine levels. In conclusion, we did not observe higher TGF-beta1 plasma
levels in plasma levels of patients receiving CsA treatment compared to blood
from the same patients while on AZA or MMF.
PMID- 10693639
TI - Administration of prostacyclin after liver transplantation: a placebo controlled
randomized trial.
AB - The shortage of suitable organs for liver grafts is responsible for the use of
marginal donors for liver transplantation (OLT). If these liver grafts function
poorly initially after OLT, a supportive therapy is necessary. The purpose of
this study was to evaluate the effects of prostacyclin (PGI2) on postoperative
liver graft function after OLT. A total of 30 adult recipients of primary OLT
were randomized to either receive PGI2 (4 ng/kg per min body weight, n = 15) or a
placebo for 6 d. To evaluate regional splanchnic oxygenation a fiberoptic
pulmonary-artery catheter was inserted into a hepatic vein and the difference
between mixed venous oxygen content and hepatic venous oxygen content was
determined (deltaO2). Measurements were performed directly after transplantation
and at 6, 12, 24 and 48 h postoperatively. A significant correlation between
deltaO2 and the level of transaminases (ALT/AST) was observed 24 and 48 h after
transplantation (p < 0.05). PGI2 treatment induced a significant decrease in
deltaO2 after 24 and 48 h after reperfusion (p < 0.05). Peak AST levels tended to
be lower in the PGI2 treatment group (418 +/- 99 vs. 638 +/- 156 U/L, p < 0.1).
These results suggest that administration of PGI2 after OLT improves hepatic
splanchnic oxygenation and may thereby reduce reperfusion injury after OLT.
PMID- 10693640
TI - Steroid withdrawal in pancreas transplant recipients.
AB - BACKGROUND: Numerous studies of steroid withdrawal have been carried out in
kidney and liver transplant recipients, but only a few in pancreas transplant
recipients. Yet, pancreas transplant recipients could have significant long-term
benefits from steroid withdrawal. METHODS: We performed a retrospective analysis
to determine the feasibility of steroid withdrawal in pancreas transplant
recipients. RESULTS: Of 360 recipients who underwent a pancreas transplant
between January 1, 1994 and June 30, 1998, 14 attempted steroid withdrawal (12
simultaneous pancreas-kidney [SPK]; 2 pancreas transplant alone [PTA]). Reasons
for steroid withdrawal were bone fractures (n = 3), psychiatric disorders (n =
2), severe acne (n = 1), recurrent infections (n = 4), and problems with
hypercholesterolemia or hypertension (n = 4). All 14 were maintained on
tacrolimus and mycophenolate mofetil (MMF) immunosuppression, except for 1 who
was on tacrolimus and azathioprine (AZA). Of the 14 recipients, 11 had no
episodes of acute rejection before steroid withdrawal. The remaining 3 had one or
more acute rejection episodes. Of the 14 recipients, 10 (72%) currently remain
off steroids (mean follow-up 18 months, range 5-51 months). However, 4 recipients
have resumed steroids: 2 after an acute rejection episode (at 2 and 21 months
post-withdrawal) and 2 because of leukopenia (WBC < 3000) and an inability to
tolerate full-dose MMF. Steroid withdrawal was unsuccessful in both PTA
recipients and in 2 of the 12 SPK recipients. All 14 recipients currently have a
functioning pancreas graft. However, 1 of the SPK recipients, in whom steroid
withdrawal failed, has developed chronic kidney rejection and is now back on
hemodialysis awaiting a retransplant. CONCLUSION: Steroid withdrawal is possible
in up to 70% of pancreas transplant recipients. Further studies are necessary to
define ideal candidates for steroid withdrawal. Based on the results of this
analysis, we have launched a prospective, randomized trial of steroid withdrawal
in pancreas transplant recipients.
PMID- 10693641
TI - Successful cadaveric renal transplantation of patients highly sensitized to HLA
Class I antigens.
AB - The purpose of our investigation was to evaluate long-term graft survival and the
role of histocompatibility in patients who were highly sensitized to human
leukocyte antigen (HLA) Class I antigens and received a cadaveric renal
transplant. Our multi-institutional study evaluated 7-yr graft outcomes and the
histocompatibility requirements of 61 (6.1%) highly sensitized (anti-human
globulin panel reactive antibody [AHG PRA], > or = 80%) cadaveric renal
transplantation patients, transplanted between 1988 and 1997, among 999
consecutive cadaveric renal transplants. One- and 7-yr graft survival in the high
PRA group (n = 61) was 76 and 59%, and was not significantly different from that
in the low PRA group (n = 938), 86 and 59% (Wilcoxon = 0.11; log-rank = 0.45)
(died with a functioning graft [DWFG] not censored). When those data were divided
into primary and regrafts, 1- and 7-yr graft outcomes for high and low PRA groups
were not significantly different [(primary, 1- and 7-yr survival: high PRA = 83
and 74%, n = 30, and low PRA = 87 and 61%, n = 825; log-rank = 0.37 for DWFG not
censored) (regrafts, 1- and 7-yr survival: high PRA = 70 and 42%, n = 31, and low
PRA = 80 and 43%, n = 113; log-rank = 0.36 for DWFG not censored)]. We did
observe a subgroup of the high PRA patient group that had inferior graft
outcomes. Graft outcome at 1 and 6 yr in the high PRA group for patients who had
one to two DR mismatches (65 and 50%, n = 41) was significantly worse than for
high PRA patients who had zero DR mismatches with their donors (100 and 78%, n =
20) (log-rank = 0.01 for DWFG not censored). Furthermore, the mean number of HLA
A and -B mismatches was significantly greater in the high PRA/DR-mismatched group
(1.7 +/- 1.2, n = 41) compared with the high PRA/zero DR-mismatched group (0.5 +/
1.1, n = 19) (p < 0.001). Overall, these data suggest that the patient who is
highly sensitized to HLA Class I antigens has a long-term graft outcome that is
equivalent to less sensitized patients, but that HLA-DR mismatching and a higher
degree of Class I mismatching may be poor prognostic indicators in such patients.
PMID- 10693642
TI - Monitoring of anti-HLA class I and II antibodies by flow cytometry in patients
after first cadaveric kidney transplantation.
AB - While the relevance of pre-formed anti-human leukocyte antigen (HLA) antibodies
has been studied extensively, the role of anti-HLA class I and II antibodies
produced after cadaveric kidney transplantation is still a matter of discussion.
As it has been proposed that they are involved in a considerable number of cases,
it should be investigated whether a post-transplant monitoring is a sensitive
parameter for the early diagnosis of acute rejection episodes. Additionally, it
has been suggested that antibodies are a major cause for chronic rejection; thus,
it would be of interest to correlate antibody detection and graft survival. We
retrospectively investigated 59 patients after a first cadaveric kidney
transplantation without known anti-HLA antibodies (complement-dependent
cytotoxicity [CDC] testing). The panel reactivity was determined with a new
highly sensitive and specific flow-cytometric technique (Flow-PRA Screening Test,
One Lambda, Canoga Park, USA) in sequentially collected serum samples pre- and
post-transplant. In patients with acute rejection episodes during the clinical
course, the last sample prior to rejection, and in patients without rejection,
the last sample prior to discharge, was analyzed. Furthermore, we analyzed 3-yr
graft survival and several clinical parameters such as cold ischemia time (CIT).
Twenty-four of 59 patients (41%) experienced acute rejections during the clinical
course. Five of 59 died with a functioning graft within the first 3 yr. Seven of
54 patients, still alive after 3 yr, lost their graft. Anti-HLA antibodies were
detectable in only 7/59 patients and a correlation between antibody positivity
and acute rejections (p = 0.32 and 0.54 for anti-HLA class I and II,
respectively) could not be identified (sensitivity 12.5 and 8.3%). However, we
found a significant correlation between the detection of anti-HLA class II and
graft loss within 3 yr (p = 0.005, specificity 97.9%). Additionally, anti-HLA
class II positive patients had significantly longer CIT (p = 0.003). Whether the
detection of anti-HLA class II antibodies in the early post-transplant phase is
of great value for the identification of patients at high risk for early graft
loss needs additional investigation. However, we found that anti-HLA antibodies
are detectable only in a minority of unsensitized patients and we conclude that
flow-cytometric monitoring with Flow PRA is not a sensitive parameter for the
early diagnosis of acute rejection episodes in patients after first cadaveric
kidney transplantation.
PMID- 10693643
TI - Should I accept this kidney?
AB - BACKGROUND: Transplant candidates frequently ask whether they should, based on
information available at the time, accept a cadaver kidney or wait for a
potentially better one. METHODS: We analyzed 937 first and second cadaver
transplants done between January 1, 1984 and December 31, 1997 to determine if
information available at the time an offer is made could be used to predict long
term graft survival. RESULTS: By Cox regression, risk factors for worse long-term
graft survival were older donor age, cardiovascular or cerebrovascular cause of
donor death, and delayed graft function (DGF). HLA-ABDR mismatch was marginally
significant. Whether DGF will occur is not known at the time of an offer, but
risk factors can be determined; we found these to be older donor age and > 10%
panel-reactive antibodies (PRA) at transplantation (by Cox regression). Using
these variables (PRA, ABDR mismatch, donor age, and donor cause of death) known
at the time of an offer, we calculated the relative risk of worse long-term graft
survival for each subgroup (Table 3 in manuscript). In general, older age and
donor death from cardiovascular or cerebrovascular disease were associated with
worse outcome. Kidneys from donors of < 50 yr had the best outcome, irrespective
of match. CONCLUSION: The data provided can be used to help guide patients as to
whether they are better off accepting an offered kidney or waiting for a
potentially better one. If an offer is declined, the next kidney may have a
potentially worse outcome.
PMID- 10693644
TI - The role of family and friend social support in reducing risk behaviors among HIV
positive Gay men.
AB - Researchers have intimated a link between social support and risk-taking
behaviors for HIV-positive persons, yet few have empirically examined this
assumption. This study examined HIV-positive Gay men regarding their perceptions
of family and friend social support, behavioral intentions, and risk-taking
behaviors. Results indicated that the more family members were perceived as
supportive the less likely participants intended to behave in risky ways. In
addition, family availability for support was more predictive of reduced risky
behaviors than the availability of friends. Implications for researchers and
helping professionals are discussed.
PMID- 10693645
TI - Sexual risk behaviors of Gay, Lesbian, and bisexual youths in New York City:
prevalence and correlates.
AB - The lifetime and recent sexual risk behaviors of 156 Gay, Lesbian, and bisexual
youths, recruited from Gay-focused organizations in New York City, were examined.
The data indicated seven reasons why the youths are at risk for HIV and other
STDs: They initiated sex during early adolescence; their first sexual partners
were older than they were; HIV barrier methods (e.g., condoms) were initiated
subsequent to sexual debut; many lifetime sexual partners and encounters were
reported; some youths exchanged sex for goods; many youths reported having had at
least one partner at risk for HIV; and the youths engaged in unprotected sexual
behaviors during the past 3 months. Significant gender differences emerged (e.g.,
the male youths reported more lifetime same-sex partners than the female youths;
the female youths reported more lifetime other-sex partners than the male
youths). Recent sexual risk behaviors (i.e., numbers of same-sex partners,
encounters, and unprotected sex during the past 3 months) were related
significantly to the youths' average degree of emotional involvement in or
average duration of intimate relationships.
PMID- 10693646
TI - Developing, implementing, and evaluating a condom promotion program targeting
sexually active adolescents.
AB - This article describes the development, implementation, and evaluation of the
Condom Campaign, a 1995 HIV prevention program promoting condom use among
sexually active adolescents in three King County, Washington, urban communities.
This program employed three main strategies: (a) mobilizing all levels of the
target communities to support and guide program development and implementation;
(b) creating and implementing a mass media campaign targeting sexually active
teenagers that promoted correct condom use and favorable attitudes toward
condoms; and (c) recruiting public agencies, community organizations, and
businesses to distribute condoms from bins and vending machines. We evaluated the
program through a series of cross-sectional interviews conducted in the three
communities chosen for their elevated levels of adolescent sexual risk behavior.
Overall, 73% of target youth reported exposure to the Condom Campaign; exposure
did not differ by age, gender, race, or level of sexual experience. Levels of
sexual activity remained stable throughout the media campaign.
PMID- 10693647
TI - What high-risk women are telling us about access to primary and reproductive
health care and HIV prevention services.
AB - Focus group discussions on barriers to health care and attitudes toward family
planning, reproductive health services, and condom use were conducted with 63
women at high risk for HIV due to their own injection drug use, sex with
injection drug users, sex industry work, or a history of multiple sexually
transmitted diseases. Barriers identified include the high cost of health care,
perceived poor quality of care and experiences of discrimination and
stigmatization, geographic accessibility, fear of legal/social services punitive
actions, misperceptions about the efficacy of birth control methods and condom
usage, lack of sterilization services, and lack of male involvement. Where
possible, findings from the focus groups are supported with quantitative survey
data from a sample of high-risk women (n = 723). Recommendations are made for
improving care for high-risk women.
PMID- 10693648
TI - The AIDS Memorial Quilt as preventative education: a developmental analysis of
the Quilt.
AB - This study consisted of a survey given to college students (N = 560) at a rural
university in the Pacific Northwest. The sample was randomly assigned into four
groups, following the Solomon four-group study design. The two levels of
treatment included interventions consisting of a visit to the AIDS Memorial Quilt
for the experimental groups and attendance at an unrelated event for the control
groups. Pretests were completed 4 weeks prior to interventions; posttests were
completed by the entire sample 4 weeks after the interventions. Results confirmed
expected differences among the four groups in terms of social distance,
perceptions of people with AIDS, self-efficacy, and discussion of risky behavior.
The results suggest that the AIDS Memorial Quilt addresses issues centrally
related to behavior change and indicates support for the message interpretation
process and stages of change models.
PMID- 10693649
TI - Oral health perceptions and adherence with dental treatment referrals among
caregivers of children with HIV.
AB - Results from a 3-year longitudinal study on the oral manifestations of AIDS (OMA)
among seropositive children and their siblings indicated poor adherence with
recommendations for dental treatment (Broder, Catalanotto, Reisine, &
Variagiannis, 1996). The purposes of this study were to (a) to examine oral
health behaviors, attitudes, and perceived barriers to care among caregivers of
children with HIV and their siblings who were referred for dental care, and (b)
develop and evaluate a 5-week summer pilot program to increase adherence with
referral for dental treatment. Telephone interviews with caregivers were
conducted to identify barriers to care and to implement services to increase
attendance in the dental clinic for their children. Interviews were completed
with 28 of the 38 (74%) caregivers recruited from the OMA study (previously
cited) who had children referred for dental treatment at the final (sixth) oral
health research exam. Twelve of their 58 children (21%) had obtained dental care
privately, 25 (62.5%) initiated treatment and 2 (6.3%) completed treatment at the
referred dental school during the 5-week pilot program. Although caregivers of
children with HIV and their siblings were responsive to the initial efforts of
the program's service coordinators, follow-up data from the coordinators' records
and chart abstraction revealed that the majority of the participants did not
appear for their second or third appointments. The interview reports suggested
that caregivers expect dental treatment, such as restorations, at each
appointment and do not regard exams/treatment planning as treatment.
Personal/family and health care delivery system factors were expressed barriers
to dental care. Implications for future programs and investigations are
discussed.
PMID- 10693650
TI - The herpesvirus proteases as targets for antiviral chemotherapy.
AB - Viruses of the family Herpesviridae are responsible for a diverse set of human
diseases. The available treatments are largely ineffective, with the exception of
a few drugs for treatment of herpes simplex virus (HSV) infections. For several
members of this DNA virus family, advances have been made recently in the
biochemistry and structural biology of the essential viral protease, revealing
common features that may be possible to exploit in the development of a new class
of anti-herpesvirus agents. The herpesvirus proteases have been identified as
belonging to a unique class of serine protease, with a Ser-His-His catalytic
triad. A new, single domain protein fold has been determined by X-ray
crystallography for the proteases of at least three different herpesviruses. Also
unique for serine proteases, dimerization has been shown to be required for
activity of the cytomegalovirus and HSV proteases. The dimerization requirement
seriously impacts methods needed for productive, functional analysis and
inhibitor discovery. The conserved functional and catalytic properties of the
herpesvirus proteases lead to common considerations for this group of proteases
in the early phases of inhibitor discovery. In general, classical serine protease
inhibitors that react with active site residues do not readily inactivate the
herpesvirus proteases. There has been progress however, with activated carbonyls
that exploit the selective nucleophilicity of the active site serine. In
addition, screening of chemical libraries has yielded novel structures as
starting points for drug development. Recent crystal structures of the
herpesvirus proteases now allow more direct interpretation of ligand structure
activity relationships. This review first describes basic functional aspects of
herpesvirus protease biology and enzymology. Then we discuss inhibitors
identified to date and the prospects for their future development.
PMID- 10693651
TI - Plant-derived and semi-synthetic calanolide compounds with in vitro activity
against both human immunodeficiency virus type 1 and human cytomegalovirus.
AB - Plant-derived and semi-synthetic calanolide compounds with anti-human
immunodeficiency virus type 1 (HIV-1) activity were tested for anti-human
cytomegalovirus (HCMV) activity in both cytopathic effect inhibition and plaque
reduction assays. The results indicated that the anti-HCMV activity of calanolide
compounds does not correlate with their activity against HIV-1. The semi
synthetic 12-keto derivatives tended to be more active against HCMV than the
corresponding 12-OH congeners, which were more active against HIV-1. It appeared
that the 7,8-unsaturated double bond in the chromene ring played a certain role
in maintaining activities against both HCMV and HIV-1. Saturation of the double
bond increased the EC50 values against both viruses, with concomitant increase in
toxicity. The calanolide compounds reported here are the first non-nucleoside
analogues capable of inhibiting both HIV-1 and HCMV and, therefore, may be useful
chemoprophylactic agents for HCMV in HIV-infected people or vice versa.
PMID- 10693652
TI - Importance of the alanine methyl ester side chain for the biological activity
profile of dual-function phenyl phosphate derivatives of bromo-methoxy
zidovudine.
AB - In a systematic search for developing a virucidal spermicide with potent anti
human immunodeficiency virus (HIV) and spermicidal activities, we synthesized and
evaluated 14 phosphoramidate derivatives of 5-bromo-6-methoxy-zidovudine (PP-BMZ)
with differing amino acid ester side chains and para substitutions on the phenyl
moiety. Anti-HIV activity was tested by measuring viral p24 antigen production as
a marker of viral replication in HIV-1-infected human peripheral blood
mononuclear cells. The effect of various PP-BMZ compounds on human sperm motion
kinematics was analysed by computer-assisted sperm analysis. Varying the Ala side
chain of the phosphoramidate group to other non-polar amino acids, including the
cyclic amino acids proline and tryptophan, led to significant alterations in both
anti-HIV and spermicidal activities. Our findings highlight the necessity of the
Ala side chain and the presence of an electron-withdrawing para-bromo substituent
on the phenyl moiety in addition to the bromo-methoxy functional groups on the
thymine ring for the PP-BMZ compounds to be effective virucidal spermicides.
These membrane permeable dual-function nucleoside analogues may provide the basis
for a new strategy aimed at prevention of the sexual transmission of HIV while
providing fertility control for women.
PMID- 10693653
TI - Prevention of murine influenza A virus pneumonitis by surfactant nano-emulsions.
AB - Non-ionic surfactant nano-emulsions have extensive anti-microbial activity and
are biocompatible with skin and mucous membranes at effective concentrations. Two
nano-emulsion formulations (8N8 and 20N10) made from soybean oil, tributyl
phosphate and Triton X-100, were tested for their ability to prevent murine
influenza virus pneumonia in vivo. In the initial study, CD-1 mice were
administered various dilutions of the nano-emulsions intranasally, and safe
dosages and concentrations were determined. Non-toxic concentrations of the nano
emulsions were then mixed with influenza virus and applied to the nares of mice.
Animals receiving mixtures of two different emulsions (8N8 or 20N10) and a LD50
of virus survived the challenge without evidence of viral infection. To determine
if the nano-emulsions could prevent influenza virus infection in vivo when used
as a prophylactic treatment, the nano-emulsions (8N8 at 1.0% and 20N10 at 1.0% or
0.2%) were applied to mouse nares 90 min before exposure to 5x10(5) p.f.u./ml
virus by nebulized aerosol. Animals pretreated with the nano-emulsions had
significantly decreased clinical signs of infection. Only 26.0% (8N8 at 1.0%),
31.25% (20N10 at 1.0%) and 37.0% (20N10 at 0.2%) of animals pretreated with nano
emulsion died from pneumonitis, whereas >80.0% of mock pretreated animals
succumbed to infection (P<0.005). These findings suggest that non-ionic
surfactant nano-emulsions have therapeutic potential for the prevention of
influenza virus infection in vivo.
PMID- 10693654
TI - A novel peptide aldehyde with activity against human cytomegalovirus in two
different in vivo models.
AB - Novel peptide aldehydes (PAs) were identified as potent inhibitors of human
cytomegalovirus (HCMV) in vitro. Although these compounds were highly effective
against HCMV, they did not exhibit any activity against murine cytomegalovirus
(MCMV). The purpose of this study was to test the antiviral activity of PA 8 as a
representative of this novel class of inhibitors against HCMV in vivo. Because of
the strict species specificity of HCMV we had to use two artificial animal
models. In the first model, HCMV-infected human cells were entrapped into agarose
plugs and transplanted into mice. In the second model, SCID mice were
transplanted with human tissues that were subsequently infected with a clinical
isolate of HCMV. In these two models the antiviral activity of PA 8 was clearly
demonstrated, ganciclovir only being slightly superior in its in vivo antiviral
activity.
PMID- 10693655
TI - TSAO-T analogues bearing amino acids at position N-3 of thymine: synthesis and
anti-human immunodeficiency virus activity.
AB - Novel analogues of the anti-HIV-1 lead compound [1-[2',5'-bis-O-(tert
butyldimethylsilyl)-beta-D-ribofuranosyl]thymine]- 3'-spiro-5'-(4"-amino-1",2"
oxathiole-2',2'-dioxide) (TSAO-T) bearing different amino acids at position N-3
of thymine were prepared and evaluated as inhibitors of HIV replication. The
synthesis of the target compounds was accomplished by coupling of the appropriate
TSAO intermediate with a conveniently protected (L) amino acid in the presence of
BOP and triethylamine, followed by deprotection of the amino acid moiety. Several
TSAO derivatives, bearing at N-3 position of the thymine base an L-amino acid
retaining the free carboxylic acid, acquired activity against HIV-2, in addition
to their inhibitory effect on HIV-1.
PMID- 10693656
TI - Antiviral effect of brassinosteroids against herpes virus and arenaviruses.
AB - A natural brassinosteroid and a series of synthetic derivatives were found to be
good inhibitors of herpes simplex virus type 1 (HSV-1) and arenavirus replication
in cell culture. The synthetic compounds tested were analogues of the 24(S)
ethylbrassinone. Compounds (22 R,23 R,24S)-2alpha, 3alpha,5alpha,22,23
pentahydroxy-stigmastan-6-one and (22R,23R,24S)-3beta-bromo-5alpha,22,23
trihydroxy stigmastan-6-one were cytotoxic at concentrations of 20-40 microM.
(22S,23S,24S)-2alpha,3alpha,22,23-tetrahydroxy-5alpha, stigmastan-6-one,
(22R,23R,24S)-3beta-acetoxy-22,23-dihydroxy-5alpha-choles tan-6-one,
(22S,23S,24S)-3beta-bromo-22,23-dihydroxy-5alpha-cholestan-6 -one and
(22S,23S,24S)-3beta-bromo-5alpha,22,23-trihydroxy-stigmastan -6-one were the most
active of the series against HSV-1, with selectivity index (SI) values
(CC50/EC50) ranging from 10.6 to 16.5. The majority of the compounds were potent
inhibitors of arenaviruses, (22S,23S,24S)-3beta-bromo-5alpha,22,23-trihydroxy
stigmastan -6-one being the most active, with SI values of 307.8 and 692.5 for
Tacaribe and Junin viruses, respectively. The antiviral activity of
brassinosteroid derivatives was not because of direct inactivation; time-of
addition experiments suggested that a late step in HSV-1 multiplication was
affected, whereas arenaviruses remained susceptible to the compounds throughout
the replicative cycle.
PMID- 10693657
TI - Predicting inpatient mortality for pediatric trauma patients with blunt injuries:
a better alternative.
AB - PURPOSE: The aim of this study was to identify significant independent predictors
of inpatient mortality rates for pediatric victims of blunt trauma and to develop
a formula for predicting the probability of inpatient mortality for these
patients. METHODS: Emergency department and inpatient data from 2,923 pediatric
victims of blunt injury in the New York State Trauma Registry in 1994 and 1995
were used to explore the relationship between patient risk factors and mortality
rate. A stepwise logistic regression model with P<.05 was developed using
survival status asthe dependent variable. Independent variables included are
elements of the Pediatric Trauma Score (PTS), additional elements from the
Revised Trauma Score (RTS), the motor response and eye opening components of the
Glasgow Coma Scale (GCS), age-specific systolic blood pressure, the AVPU score,
and 2 measures of anatomic injury severity (the Injury Severity Score [ISS] and
the International Classification of Disease, Ninth Revision-based Injury Severity
Score [ICISS]). RESULTS: The only significant independent predictors of severity
that emerged were the ICISS, no motor response (best motor response = 1) from the
GCS, and the unresponsive component from the AVPU score. The statistical model
exhibited an excellent fit (C statistic = .964). The specificity associated with
the prediction of inpatient mortality rate based on the presence of 1 or more of
these risk factors was .926, and the sensitivity was .944. CONCLUSION: The best
independent predictors of inpatient mortality rate for pediatric trauma patients
with blunt injuries include variables not specifically contained in the PTS or
the RTS: ICISS, no motor response (best motor response = 1) from the GCS, and the
unresponsive component of the AVPU score.
PMID- 10693658
TI - Pediatric airbag injuries: the Ohio experience.
AB - BACKGROUND/PURPOSE: We sought to determine if properly restrained children, less
than 13 years of age, placed in the front passenger seat are at greater risk for
trauma from airbag deployment than unrestrained children. METHODS: The charts of
children treated at any of 3 regional pediatric trauma centers in Ohio were
reviewed for airbag injuries sustained in motor vehicle crashes between January
1995 and September 1998. Injury Severity Scores (ISS) were compared with Mann
Whitney Rank Sum Test and outcome data with Fisher's Exact Tests. Statistical
significance was set at P< or =.05. RESULTS: Twenty-seven children aged 1 month
to 12 years sustained airbag-related injuries. Sixty-one percent were girls. ISS
ranged from 1 to 75 with a mean score (+/- SD) of 10 (14.5). All crashes were at
reported speeds of less than 45 mph, and 64% were head-on collisions. No
significant differences in the mean ISS (P = .074) occurred between groups. Both
groups had similar closed head, ocular and facial injuries, extremity fractures,
and number of deaths (P = 1.0). Abdominal organ injury was exclusive to the
restrained group. Decapitation only occurred among unrestrained children.
CONCLUSION: Our data showed that airbags, with or without proper safety
restraints, can lead to mortality or serious morbidity in children.
PMID- 10693659
TI - Evidence-based guidelines for resource utilization in children with isolated
spleen or liver injury. The APSA Trauma Committee.
AB - PURPOSE: This study is intended to resolve the disparity and reach consensus on
issues regarding the treatment of children with isolated spleen or liver
injuries. To maximize patient safety and assure efficient, cost-effective
utilization of resources, it was essential to determine current practice.
METHODS: Data from the case records of 856 children with isolated spleen or liver
injury treated at 32 pediatric surgical centers from July 1995 to June 1997 were
collected. The severity of injury was classified by computed tomography (CT)
grade and the data analyzed for intensive care unit (ICU) stay, length of
hospital stay, transfusion requirement, need for operation, pre- and
postdischarge imaging, and restriction of physical activity. Patients with grade
V injuries (2.8%) were excluded leaving 832 patients for detailed review. These
data and available literature were analyzed for consensus by the 1998 APSA Trauma
Committee. RESULTS: Resource utilization increased with injury severity (see
Table 2). Based on the data analysis, literature search, and consensus
conference, the authors propose guidelines (see Table 3) for the safe and optimal
utilization of resources in routine cases. It is important to emphasize that no
recommendation falls outside the 25th percentile of current practice at
participating centers. CONCLUSIONS: Diversity of treatment, with attendant
variation in resource utilization in children with isolated spleen and liver
injury of comparable severity is confirmed. This analysis has stimulated a
prospective outcomes study with the objective of validating the evidence-based
guidelines proposed. This evidence-based study design can bring order and
conformity to patient management resulting in optimal utilization of resources
while maximizing patient safety.
PMID- 10693660
TI - Multiple spontaneous small bowel anastomosis in premature infants with
multisegmental necrotizing enterocolitis.
AB - BACKGROUND/PURPOSE: Fulminant necrotizing enterocolitis (NEC) may result in
extensive bowel necrosis. Resection of involved segments may result in short
bowel syndrome. Multiple stomas result in complications and further loss of
intestinal length with closure. METHODS: Two patients with extensive
multisegmental NEC were treated with an intraluminal stent without anastomosis.
All necrotic intestine was resected and the remaining viable intestine was lined
up over a feeding tube without anastomosis of the intestinal segments. One
patient had a diverting jejunostomy and mucous fistula with the tube used to
orient the defunctionalized intervening intestinal segments. The second patient
had the bowel left in continuity with the tube brought into the jejunem proximal
to the first area of resection and distally brought out through the tip of the
appendix. Both tubes were brought through the abdominal wall and secured in a
loop. RESULTS: Contrast study findings showed that the intestinal segments had
auto-anastomosed. In the first case the tube was left in place and intestinal
continuity was restored. The patient is now 4 years old and takes full enteral
feeds. The latter patient had the enterostomy tube removed at the time of the
contrast study, but only tolerated partial feedings and died at 1 year of total
parenteral nutrition-related liver failure. CONCLUSION: The technique eliminates
nonviable bowel, maximizes length, avoids multiple stomas, and may help avoid
reoperation.
PMID- 10693661
TI - Diminished epidermal growth factor levels in infants with necrotizing
enterocolitis.
AB - BACKGROUND/PURPOSE: Because epidermal growth factor (EGF) is trophic to the
intestinal mucosa, and neonatal necrotizing enterocolitis (NEC) is associated
with a disrupted intestinal mucosal barrier, the authors sought to determine
whether diminished levels of EGF were present in infants with NEC. METHODS:
Saliva, serum, and urine specimens were obtained from infants with NEC during a 3
year period (February 1995 to May 1998). Control patients without NEC were chosen
based on similar postnatal age and birthweight. EGF levels were determined by
enzyme-linked immunosorbent assay (ELISA). Differences between groups were
compared using Mann-Whitney Rank sum test with P less than .05 considered
significant. Results are presented as mean values +/-SEM. RESULTS: Twenty-five
infants with NEC were compared with 19 control patients. Birth weight (1,616+/
238 g control v. 1,271+/-124 g NEC) and postnatal age (23+/-6 days control v.
22+/-3 days NEC) were similar. Infants with NEC had significantly lower levels of
EGF in both saliva (590+/-80 pg/mL control v. 239+/-41 pg/mL NEC; P<.001) and
serum (35+/-8 pg/mL control v. 5.6+/-1.9 pg/mL NEC; P<.001). Urinary EGF was also
lower in the NEC group, but was not statistically significant. CONCLUSIONS:
Premature infants with NEC have significantly diminished levels of salivary and
serum EGF. Reduced levels of this growth factor may distinguish infants at risk
for NEC and play a pivotal role in the pathogenesis of the perturbed intestinal
mucosal barrier that is central to this condition.
PMID- 10693662
TI - Erythropoietin and the incidence of necrotizing enterocolitis in infants with
very low birth weight.
AB - BACKGROUND/PURPOSE: The presence of erythropoietin (Epo) in human milk and the
expression of Epo receptors on intestinal villous enterocytes of neonates suggest
that Epo has a role in growth and development of the gastrointestinal tract. On
this basis, the authors hypothesized that recombinant Epo (rEpo) given for
prevention or treatment of the anemia of prematurity would protect against
necrotizing enterocolitis (NEC). METHODS: A retrospective cohort study was
conducted from a university neonatal intensive care unit of 483 very low birth
weight (500 to 1,250 g) neonates born from July 1, 1993 to January 1, 1998.
RESULTS: A total of 260 neonates received rEpo, and 223 did not (control group).
The rEpo and control groups were similar in gender distribution (52% v. 48%
boys), gestational age (26.8+/-2.1 v. 27.6+/-2.9 weeks; mean +/- SD), birth
weight (895+/-198 v. 911+/-208 g), 1 and 5 minute Apgar scores (4.2 and 6.1 v4.7
and 6.7), and incidence of severe intraventricular hemorrhage (8.9% v. 10.3%).
The rEpo group had a lower incidence of NEC (12 of 260, 4.6% v. 24 of 223, 10.8%;
P = .028, 95% confidence interval for difference: -0.108 to -0.015). CONCLUSION:
In very low birth weight infants, the incidence of NEC is lower in those who
received rEpo.
PMID- 10693663
TI - Myofibroblast induction with transforming growth factor-beta1 and -beta3 in
cutaneous fetal excisional wounds.
AB - BACKGROUND/PURPOSE: In a noncontractile fetal rabbit model, the authors recently
have shown the induction of excisional wound contraction with sustained-release
cellulose implants formulated with transforming growth factor (TGF)-beta. The
purpose of this study was to test the hypothesis that the excisional wound
contraction in this model is associated with the induction of myofibroblasts in
the surrounding dermis, demonstrated by the presence of alpha-smooth muscle
actin. METHODS: Cellulose discs were formulated with either 1.0 microg of TGF
beta1 (n = 6); 1.0 microg of TGF-beta3 (n = 9); 10 microg of TGF-beta3 (n = 6);
or their carrier protein, bovine serum albumin (BSA; n = 9), for sustained
release over 5 days. Each disc was implanted into a subcutaneous pocket on the
back of a fetal New Zealand White rabbit in utero on day 24 of gestation (term,
31 days). A full-thickness, 3-mm excisional wound (7.4 mm2) was then made next to
the implanted cellulose disc. All fetuses were harvested at 3 days. The amount of
alpha-smooth muscle (SM) actin in the dermis around the implants and wounds was
determined using immunohistochemical techniques. RESULTS: Excisional wounds
exposed to 1.0 microg of TGF-beta1 (5.6+/-2.0 mm2), 1.0 microg of TGF-beta3
(6.9+/-1.0 mm2), and 10 microg of TGF-beta3 (2.7+/-1.0 mm2) were significantly
smaller when compared with the BSA control group (12.8+/-1.1 mm2; P<.05).
Furthermore, there was a significant increase in staining for alpha-SM actin in
the TGF-beta1 (1.8+/-0.5) and 10 microg TGF-beta3 (2.8+/-0.2) groups in
comparison with the scant staining in the BSA control group (0.5+/-0.2; P<.05).
CONCLUSIONS: TGF-beta1 and -beta3 induce alpha-SM actin and contraction of
cutaneous excisional wounds in a fetal noncontractile model. This model of
inducible cutaneous excisional wound contraction may be useful in further
determining the role of the myofibroblast in wound contraction and the physiology
underlying this poorly understood aspect of wound healing.
PMID- 10693664
TI - TNP-470 inhibits intraabdominal adhesion formation.
AB - BACKGROUND/PURPOSE: Angiogenesis plays an integral role in wound healing and
tissue remodeling. The authors hypothesized that inhibition of angiogenesis would
reduce intraabdominal adhesion formation. METHODS: In 98 C57BL6/J mice, a 2-cm
midline laparotomy was performed and a 5 mm2 SILASTIC (Dow Corning, Midland, MI)
patch fixed to the right side of the peritoneum. Mice were injected with normal
saline (n = 54) or TNP-470, an inhibitor of angiogenesis (n = 44; 30 mg/kg every
other day over 6 days before surgery until 10 days after surgery). Animals were
killed on postoperative days 10, 15, 35, and 55. Adhesions to the SILASTIC (Dow
Corning) patch were scored based on their extent, type, and tenacity.
Angiogenesis was quantified digitally as the area of vascularized peritoneum over
the patch. RESULTS: At day 10, when TNP-470 was stopped, the percentage of
vascularized peritoneum over the patch was less in treatment animals than in
controls (P = .004). At day 35, the patch in treatment animals was completely
covered by vascularized peritoneum, similar to controls. Adhesions in TNP-470
animals were reduced at day 10 compared with controls (P<.05) and remained
reduced off treatment at day 55. CONCLUSIONS: Angiogenesis appears to play an
important role in the development of intraabdominal adhesions, because the extent
of early neovascularization correlates with adhesion formation. Perioperative
treatment with TNP-470, a potent endothelial cell inhibitor, reduced vessel
ingrowth over the patch and was associated with a sustained reduction in adhesion
formation.
PMID- 10693665
TI - Extracorporeal life support outcome for 128 pediatric patients with respiratory
failure.
AB - PURPOSE: The aim of this study was to describe a single-center experience with
pediatric extracorporeal life support (ECLS) and to determine variables
predictive of outcome in pediatric patients, both before the institution of ECLS
and while on support. METHODS: From October 1985 to September 1998 the authors
supported 128 children with severe acute hypoxemic respiratory failure(n = 121,
Pao2/FIo2 ratio = 58+/-29) or acute hypercarbic respiratory failure (n = 7, Paco2
= 128+/-37), despite maximal conventional ventilation. Mode of access included
venoarterial bypass (VA, n = 64), venovenous bypass (VV, n = 53), and VV to VA
bypass (n = 11). The techniques used included lung rest, pulmonary physiotherapy,
diuresis to dry weight using hemofiltration if needed, minimal anticoagulation,
and optimal systemic oxygen delivery. RESULTS: The median age was 1.4 years
(range, 2 weeks to 17 years). The mean duration of ECLS was 288+/-240 hours
(range, 4 to 1148 hours or 0.2 to 47.8 days). Lung compliance increased from
0.32+/-0.02 mL/cm H2O/kg to 0.59+/-0.03 mL/cm H2O/kg in survivors, but only
increased from 0.34+/-0.02 mL/cm H2O/kg to 0.35+/-0.02 mL/cm H2O/kg in
nonsurvivors (P<.002 comparing change between survivors and nonsurvivors). Mean
body weight decreased from 9%+/-2% over dry weight to 4%+/-2% in survivors,
whereas in nonsurvivors the mean body weight increased from 25%+/-5% over dry
weight to 35%+/-7% (P<.001). Outcome results by diagnosis were pneumonia, 73%;
acute respiratory distress syndrome, 67%; and airway support, 60%, with overall
lung recovery occurring in 77%, and hospital survival in 71%. Multivariate
logistic regression modelling of patients with hypoxemic respiratory failure
found the only pre-ECLS variable significantly associated with outcome to be pH
(P<.05). Variables during the course of ECLS significantly associated with
decreased survival were the presence of creatinine greater than 3.0 (P<.01), the
need for inotropes (P<.04), failure to return the patient to dry weight (P<.04),
and lung compliance that did not improve significantly. (P<.01). CONCLUSIONS:
ECLS provides life support in severe respiratory failure in children, allowing
time for injured lungs to recover. Pre-ECLS predictors, such as pH and variables
during ECLS, such as presence of renal failure, improvement in compliance, return
to dry weight, and the need for inotropes on ECLS, may be useful for predicting
outcome.
PMID- 10693666
TI - Antenatal dexamethasone enhances endothelin receptorB expression in hypoplastic
lung in nitrofen-induced diaphragmatic hernia in rats.
AB - BACKGROUND/PURPOSE: The hypoplastic lung and persistent pulmonary hypertension
(PPH) are the principle causes of high mortality and morbidity in infants with
congenital diaphragmatic hernia (CDH). Endothelin-1 (ET-1), which is produced by
vascular endothelial cells and some leukocytes, plays a key role in modulating
pulmonary vascular tone in PPH. Two different receptors (ET(A) and ET(B)) for ET
1 have been characterized. Binding of ET-1 to ET(A), which is present on smooth
muscle cells in fetal lung, results in vasoconstriction. However, binding of ET-1
to ET(B), which is present on endothelial cells results in vasodilation mediated
by endogenous nitric oxide. Antenatal glucocorticoid therapy has been shown to
prevent abnormal pulmonary arterial structural changes in animal model with CDH.
The aim of this study was to investigate the effect of antenatal glucocorticoid
administration on ET-1 system in nitrofen-induced CDH hypoplastic lung in rats.
METHODS: A CDH model was induced in pregnant rats after administration of
nitrofen on day 9.5 of gestation. Dexamethasone (Dex) was given intraperitoneally
on days 18.5 and 19.5 of gestation. Cesarean section was performed on day 21 of
gestation. Rat ET-1 protein expression was measured in solubilized lung tissue
extracts, by sandwich type enzyme-linked immunosorbent assay (ELISA) analysis.
Reverse transcription polymerase chain reaction was performed to evaluate the
relative amount of ET-1, ET(A), and ET(B) mRNA expression. RESULTS: The ET-1
protein and mRNA expression of ET-1 and both receptors were increased
significantly in CDH lung compared with controls. Although there was no
significant difference in ET(A) mRNA expression between CDH lung with Dex
treatment and without Dex treatment, ET(B) mRNA expression was elevated
significantly in CDH lung with Dex treatment compared with CDH lung without Dex
treatment. CONCLUSION: These findings suggest that antenatal glucocorticoid
therapy may modulate pulmonary vascular tone in CDH hypoplastic lung by
selectively upregulating local expression of ET(B).
PMID- 10693667
TI - Remodeling of pulmonary arteries in human congenital diaphragmatic hernia with or
without extracorporeal membrane oxygenation.
AB - PURPOSE: The aim of this study was to describe in detail the perinatal
developmental profile of the pulmonary vasculature in congenital diaphragmatic
hernia (CDH) and to examine the potential beneficial effects of extracorporeal
membrane oxygenation (ECMO) on the vascular morphology. Additionally the authors
aimed to identify the differences in pulmonary vascular morphology among CDH
cases according to the primary cause of death: either extreme lung hypoplasia
(LH) or persistent pulmonary hypertension (PPH). METHODS: The authors studied
autopsy sections from 30 high-risk CDH cases with respect to the pulmonary
arteries in relation to gestational age (GA) and ECMO treatment. They were
grouped into CDH-I: 20 cases with GA greater than 34 weeks who were not subjected
to ECMO and CDH-II: 10 cases with GA greater than 34 weeks, who were subjected to
ECMO for an average time of 237 hours. Five age-matched neonates who died from
placental insufficiency or birth asphyxia without evidence of lung hypoplasia
served as controls (CON). Medial and adventitial thicknesses of pulmonary
arteries were measured in lung sections stained with Elastic van Gieson by 2
investigators blinded for the clinical data. Immunohistological staining with
anti-alpha-smooth muscle actin (alpha-SMA) was performed to confirm the precise
location of the arterial media before morphometry. CDH cases were subgrouped and
compared according to the primary cause of death. Unpaired Student t test was
used for statistics, with significant P value < or =.05. RESULTS: In CDH
newborns, a significant increase in medial, adventitial, and total wall thickness
was found in pulmonary arteries with an external diameter of less than 200 microm
as compared with age-matched controls (P<.004, .0001, and .0009, respectively).
ECMO-treated CDH newborns showed a significantly thinner arterial adventitia than
CDH patients who did not receive this treatment (P<.0001), approaching normal
values. However, the medial thickness remained increased. Morphometrically, no
significant differences in CDH cases between patients dying of PPH or severe LH
could be determined. CONCLUSIONS: (1) In CDH, there is failure of the normal
arterial remodeling processes occurring in the perinatal period. (2) Pulmonary
vascular morphology in CDH does not differ between the groups with lung
hypoplasia or persistent pulmonary hypertension as primary cause of death. (3)
Adventitial thinning of these arteries might be one of the mechanisms by which
ECMO alters PPH in CDH cases.
PMID- 10693668
TI - Lung growth induced by tracheal occlusion in the sheep is augmented by airway
pressurization.
AB - BACKGROUND/PURPOSE: Prenatal tracheal occlusion (TO) has been shown to accelerate
lung growth, yet the mechanism for this effect is poorly understood. Increased
intratracheal pressure (ITP) with accumulation of lung fluid and secondary airway
distension (stretch) may provide a mechanical stimulus for growth. In this study,
ITP after TO is measured continuously, and the effect of altering ITP on lung
growth is examined. METHODS: Fetal lambs of 115 to 120 days of gestation (term,
145 days) underwent placement of an intratracheal catheter and an amniotic fluid
reference catheter. First, ITP was monitored continuously in normal controls (n =
4) and in fetuses undergoing TO (n = 6). In a subsequent study, 2 groups of
fetuses were compared. In the TO group (n = 5) ITP was monitored after TO. In the
pressurized group (n = 5) ITP was maintained at 7 to 8 mm Hg by a continuous
servo regulated pump that maintains a preset pressure by lactated Ringers
infusion. The animals were killed after 4 days, and lung growth was compared.
RESULTS: In the control animals, ITP remained constant at 0.4 to 1.5 mm Hg. In
the TO animals, ITP increased gradually during the initial 24 hours and plateaued
at 4 to 5 mm Hg. In the second set of animals, ITP in the pressurized group was
maintained at approximately 8 mm Hg using the infusion system. Lung volume
(135.7+/-17.4 v. 95.2+/-14.8 mL/kg; P<.01), lung weight to body weight (6.70+/
0.73 v. 5.33+/-0.77%; P<.05), whole right lung dry weight (3.10+/-0.22 v. 2.63+/
0.20 mg/kg; P<.05), and right lung DNA and protein contents (87.3+/-6.0 v. 74.6+/
8.1 mg/kg, 2,310+/-248 v. 1,860+/-196 mg/kg, respectively; P<.05) were increased
significantly in the pressurized group compared with the TO group. Morphometry
confirmed greater volume of respiratory region and increased alveolar surface
area in the pressurized lung. CONCLUSIONS: TO results in a gradual increase in
ITP over 15 to 24 hours, which plateaus at 4 to 5 mm Hg. Further increasing ITP
by infusion of crystalloid significantly augments lung growth beyond that
observed with TO alone. These data support the hypothesis that airway pressure
and secondary mechanical stretch are the primary stimuli of TO induced lung
growth.
PMID- 10693669
TI - Adrenocortical insufficiency in infants with congenital diaphragmatic hernia: a
pilot study.
AB - BACKGROUND/PURPOSE: Prior reports have documented that premature infants do not
have normal serum levels of cortisol. In contrast, full-term infants usually have
adequate cortisol levels. The stress response in critically ill infants may be
vital to their recovery. The purpose of this pilot study was to determine whether
critically ill full-term infants with congenital diaphragmatic hernia (CDH) show
a subnormal adrenal stress response. METHODS: Random serum cortisol levels in
infants with CDH (n = 10) were measured using fluorescent polarization
immunoassay. In addition, serum cortisol levels were measured after exogenous
adrenocorticotropic hormone stimulation (Cosyntropin stimulation test). RESULTS:
Six of the 10 infants studied died. Most (79%) of the cortisol levels were
subnormal (<7 microgm/dL). Although no significant differences in mean cortisol
levels from terminally ill infants compared with surviving infants were detected,
survivors tended to have higher cortisol levels. Cosyntropin stimulation resulted
in inappropriately low cortisol levels in 2 of the 4 fatally ill patients tested
(<30 microgm/dL) and normal responses in the 2 survivors tested. CONCLUSIONS:
Infants born with CDH may have an inadequate adrenal stress response despite a
life-threatening anomaly. A large-scale prospective study may be warranted to
confirm this apparent association. Corticosteroid therapy may be beneficial in
this population of patients.
PMID- 10693670
TI - New mouse models of congenital anorectal malformations.
AB - BACKGROUND/PURPOSE: The genetic, embryological, and pathogenetic aspects of
hindgut development remain poorly understood. Recently, the morphogenetic pathway
involving the Sonic hedgehog (Shh) gene has been shown essential to the normal
development of many midaxial organs, including the foregut. This study reports
genetically based murine models of congenital anorectal malformations (CAM)
involving the Shh-responsive transcription factors, Gli2 and Gli3. Its purpose is
to show the necessity of these 2 factors to normal hindgut development. METHODS:
Gli2-/- mutants were generated by a targeted deletion. Gli3-/- mutants are
spontaneous mutants involving the Gli3 gene. Gli2-/- Gli3+/- mutants were
generated by intercrossing double heterozygotes. Whole-mount midsagittal sections
of the embryos were analyzed on embryonic days (E) 11.5 and E13.5. RESULTS: Gli3
/- mutants had anal stenosis and ectopic anus, and Gli2-/- mutants showed
imperforate anus and rectourethral fistula. Gli2-/- Gli3+/- mutants had a cloacal
abnormality. CONCLUSIONS: The phenotypic abnormalities observed in these mutant
mice are identical to the spectrum of human CAM. The severity of the phenotype
appears to reflect the gene dose. Gli2 and Gli3 play an important role in the
normal development of murine hindgut. The results of this study provide, for the
first time, a molecular basis for CAM.
PMID- 10693671
TI - Home bowel preparation for elective colonic procedures in children: cost savings
with quality assurance and improvement.
AB - BACKGROUND/PURPOSE: The current health care environment pressures providers to
lower cost and demands quality care that is measured by outcomes and patient
satisfaction. Most insurers will not approve bed days for in-hospital
preoperative bowel preparations for elective colorectal procedures. This policy
does not take into account that infants and children are unable to tolerate large
volumes of enteral preparation, which adversely affects outcome because of an
inadequate preparation. This report describes a prospective evaluation of a
standard home bowel preparation regimen utilizing local and regional home health
care agency support. METHODS: For an elective colorectal procedure, pediatric
patients underwent a home bowel preparation using GoLYTELY (100 mL/kg) via a
nasogastric tube infused over 4 hours by a pediatric home health nurse trained in
this technique. During the bowel preparation, the nurse educated the family
members about the service and performed physiological monitoring to insure
safety. At the completion of the preparation, any unusual events were transmitted
to the staff surgeon for further instructions. Our initial 30 patients were
treated by our hospital home health agency personnel to insure safety. Since
then, 41 additional bowel preparations have been performed by statewide agencies.
RESULTS: Seventy-one patients underwent complete home bowel preparation (45 boys;
26 girls). The age range was 3 months to 9 years (average, 5 months). There was
one complication caused by incorrect mixing of GoLYTELY causing gastrointestinal
cramping. All 71 home bowel preparations were recorded as good at the time of the
colorectal procedure by the staff pediatric surgeon. The average cost for home
bowel preparation was $300 in network, and $350 out of network. This compares
with an inpatient hospital day cost of greater than $800 ($36,000 savings).
CONCLUSIONS: This technique offers the pediatric surgeon an opportunity to
maintain a high standard of quality care while using home health agency personnel
to minimize cost. This program is safe, effective, and associated with a good
outcome and a high degree of family satisfaction.
PMID- 10693672
TI - Transanal mucosectomy in the treatment of Hirschsprung's disease.
AB - BACKGROUND/PURPOSE: Transanal mucosectomy of the aganglionic segment of colon is
a critical step in minimally invasive surgery for Hirschsprung's disease. The
purpose of this study was to examine the outcome of patients undergoing transanal
mucosectomy. METHODS: From January 1979 to November 1998, 26 patients (ages 25
days to 17 years) underwent transanal mucosectomy for Hirschsprung's disease.
Seventeen (65%) had partial transanal mucosectomy (PTM; 1979 to 1998) and 9 (35%)
complete transanal mucosectomy (CTM; 1995 to 1998). In PTM, a 2- to 3-cm mucosal
dissection was begun 1 cm above the dentate line in conjunction with
transabdominal endorectal dissection (modified Soave). In CTM, the entire mucosal
dissection was performed transanally as part of a laparoscopically assisted Soave
procedure. Results were obtained by chart review and personal communication.
Patients were assessed clinically for continence where age appropriate (>3 years)
and for development of constipation, postoperative enterocolitis, and anal
stricture. RESULTS: One of 16 (6.2%) of the PTM group was incontinent versus none
(4 patients) in the CTM group. Five of 17 (29.4%) of the PTM group were
constipated versus 4 of 9 (44.4%) in the CTM group (t test, P = not significant).
Postoperative enterocolitis developed in 4 of 17 (23.5%) of the PTM group versus
6 of 9 (66.6%) in the CTM group (t test, P<.05). Three of 6 (50%) of the CTM
group versus none in the PTM group required hospitalization for bowel rest,
rectal washouts, and antibiotics. All patients were well at the time of the
report. Anal stricture was not seen in either group. CONCLUSIONS: Constipation
and postoperative enterocolitis are a significant feature of transanal
mucosectomy for Hirschsprung's disease deserving close surveillance, especially
in patients in whom the entire mucosal dissection was performed transanally.
Continence appears to be satisfactorily preserved from these preliminary results.
PMID- 10693673
TI - Historical changes in the postoperative treatment of appendicitis in children:
impact on medical outcome.
AB - BACKGROUND/PURPOSE: The introduction of managed care in the 1980s caused
increased pressure to reduce costs for hospitalized patients. The authors
hypothesized that these market forces have resulted in a decreased hospital stay
and utilization of sophisticated diagnostic testing in children treated for
appendicitis. If true, the impact of this paradigm shift on patient outcome is
unknown. METHODS: Hospital records for 913 pediatric patients treated for
appendicitis from 1974 to 1998 were reviewed retrospectively. Patients were
stratified into those with perforated appendicitis (PA) and nonperforated
appendicitis (NPA). Demographics, perioperative hospital course, diagnostic
testing, complications, and long-term outcomes were analyzed after stratification
into time intervals. RESULTS: Over time, children with NPA were treated with
shorter antibiotic courses (P<.05) and were placed on a regular diet earlier
(P<.05). These changes in treatment resulted in an earlier discharge (P<.05). The
amount of time to become afebrile with a normal white blood cell count (WBC) did
not change over time. Children with PA exhibited similar results with shorter
antibiotic courses (P<.05), earlier dietary intake (P<.05) and earlier hospital
discharge (P<.05) over time. In all children with appendicitis there was no
significant difference in the rate of wound infections, abscesses requiring
drains, readmission, or reoperations overtime. The utilization of abdominal
radiographs (83%) and ultrasonography (USN; 40%) was high and remained unchanged
over time. Utilization of computed tomography (CT scan) was low (4.3%) in the
early decades and was not used as a preoperative test from 1991 to 1994. Given
the high diagnostic accuracy of a pediatric surgeon for this disease, Bayesian
analysis indicates that USN utilization rates should be 15%. CONCLUSIONS: The
market pressures of managed care have resulted in a new treatment paradigm with
an earlier discharge of all children with appendicitis. There has been no
concomitant increase in the complication rate in either group as a result of this
paradigm shift. Bayesian analysis indicates that USN and abdominal radiographs
are overutilized in our institution.
PMID- 10693674
TI - Is the grass greener? Early results of the Nuss procedure.
AB - BACKGROUND/PURPOSE: Minimal access surgery (MIS, Nuss Procedure) is gaining
acceptance rapidly as the preferred method for pectus excavatum repair. This
shift in operative management has followed a single institution's evaluation of
the procedure. This report describes an additional experience with the Nuss
procedure. METHODS: Twenty-one patients with pectus excavatum underwent repair by
the Nuss Procedure. The patients ranged in age from 5 to 15 years (average, 8.2
years). There were 19 boys and 2 girls. RESULTS: In 1 patient (age 5 years) the
MIS procedure was aborted because of persistence of chest wall asymmetry. The
other 20 patients had completion of their procedure without intraoperative
complication. The operating times ranged from 45 to 90 minutes; however, there
was an additional anesthetic set-up time (average, 45 minutes). All cases
utilized a single support bar (11 to 17 inches). Patients underwent extubation in
the operating room and were admitted to a ward bed with an epidural catheter in
place for pain control and received intravenous analgesia. The hospital stay
ranged from 4 to 11 days and averaged 4.9 days. Early postoperative complications
included ileus (n = 1), bilateral pleural effusion (n = 2), atelectasis (n = 1),
fungal dermatitis (n = 1), pneumothorax (n = 1), and flipped pectus bar (n = 2).
Delayed complications included flipped pectus bar (n = 2), marked pectus
carinatum requiring bar removal (n = 1), mild carinatum (n = 1), mild bar
deviation (n = 1), progressive chest wall asymmetry (n = 3) with 1 requiring bar
removal and open pectus repair, pleural effusion (n = 1), and chronic persistent
pain requiring bar removal (n = 1). The length of follow-up is 3 to 20 months
with an average of 12.3 months. CONCLUSIONS: The Nuss Procedure is quick,
minimally invasive, and a technically easy method to learn; however, our data
indicate there is a significant learning curve. Although previous reports suggest
that few complications occur, we believe further assessment of patient selection
regarding age, presence of connective tissue disorder, and severe chest wall
asymmetry are still needed. Long-term follow-up also will be required to assure
both health professionals and the public that this is the procedure of choice for
patients with pectus excavatum.
PMID- 10693675
TI - Outcome analysis of minimally invasive repair of pectus excavatum: review of 251
cases.
AB - BACKGROUND/PURPOSE: Since the first report in 1997 by Dr Nuss of the technique
for minimally invasive repair of pectus excavatum (MIRPE), the popularity and
demand for this operation has increased dramatically. Many pediatric surgeons
became familiarized with MIRPE and have applied it to a large number of patients.
Outcomes and complications have not yet been defined. METHODS: A comprehensive
survey of APSA members was conducted to review technical problems, complications,
and outcomes of this new technique. RESULTS: Of the 74 survey responders, 31
(42%) currently use the MIRPE as their procedure of choice, and 251 cases were
reviewed. A total of 74.2% of surgeons relied on direct observation and written
documentation to obtain training in MIRPE. Less than 60% used the chest index in
the preoperative assessment. A total of 98% used the Walter Lorenz bar for the
MIRPE. The most common complication was bar displacement or rotation requiring
reoperation (9.2%). Pneumothorax requiring tube thoracostomy was reported in
4.8%. Less common problems included infectious complications (2%), pleural
effusion (2%), thoracic outlet obstruction (0.8%), cardiac injury (0.4%), sternal
erosion (0.4%), pericarditis (0.4%), and anterior thoracic artery pseudoaneurysm
(0.4%). Three patients (1.2%) required early strut removal. Reoperation using the
open modified Ravitch approach was performed in 2 patients (0.8%). Most surgeons
indicated that teenaged patients (>15 years old) were at higher risk for
complications. Thoracoscopy in combination with MIRPE was used by 61% of the
surgeons. Overall patient satisfaction was rated as excellent or good (96.5%).
CONCLUSIONS: The relatively high incidence of problems with MIRPE is probably
related to the learning curve associated with the introduction of this new
technique. Awareness of technical details, careful patient selection, use of a
stabilizing bar, and thoracoscopy likely will result in decreased complications.
Long-term results are yet to be determined. The development of a national
registry is of great importance for further outcome analysis of MIRPE.
PMID- 10693676
TI - Slide tracheoplasty for congenital tracheal stenosis: a case report.
AB - BACKGROUND/PURPOSE: A variety of techniques have been used to manage pediatric
congenital tracheal stenosis. The authors report the technique of slide
tracheoplasty for a child with long congenital tracheal stenosis. METHODS: A 2
year-old male presented with a history of stridor with feeding. Bronchoscopy
findings showed 50% stenosis from complete cartilaginous rings, extending from
2.5 cm below the vocal cords to 2 cm above the carina. Through a neck incision,
the trachea was exposed from the cricoid to both bronchi and transected at the
midpoint of the stenosis. The upper trachea was split anteriorly to the area of
stenosis just below the cricoid. The lower trachea was split posteriorly in the
midline. Posterior dissection allowed sliding and anastomosis of both tracheal
segments while the lateral vascular supply was left intact. A brace was placed to
maintain cervical flexion, and the patient underwent extubation in the operating
room. RESULTS: He recovered without complication and was dis charged on
postoperative day 4. CONCLUSION: Slide tracheoplasty offers several advantages
for tracheal reconstruction because it is performed with the native tracheal
tissues, can be accomplished through a transverse collar incision, and can repair
long stenoses without significant tracheal shortening.
PMID- 10693677
TI - A new method of treatment for complete tracheal rings in an infant: endoscopic
laser division and balloon dilation.
AB - PURPOSE: The authors describe a new technique for management of complete tracheal
rings in infants. METHODS: The procedure consists of rigid bronchoscopy with KTP
laser division, in the posterior midline, of the complete rings and gradual
advancement of the bronchoscope aided by endoscopic balloon dilation.
CONCLUSIONS: The laser division, coupled with balloon dilation, allows for
controlled separation of the cartilages posteriorly. The anterior esophageal wall
buttresses the posterior tracheal separation.
PMID- 10693678
TI - Management of parapneumonic collections in infants and children.
AB - BACKGROUND/PURPOSE: Video-assisted thoracoscopic surgery (VATS) has a recognized
role in treatment of empyema thoracis. The purpose of this report is to show the
value of initial VATS as the primary treatment of parapneumonic collections.
METHODS: A retrospective review was done of 139 children who required surgical
consultation for parapneumonic collections between January 1992 and July 1998.
Management options were (M1) thoracentesis, chest tube drainage, or fibrinolytic
therapy and delayed thoracotomy for unresolved collections; (M2) thoracentesis,
chest tube drainage, fibrinolytic therapy with delayed VATS if the child remained
ill; or (M3) primary VATS. Comparative data included age, duration of prehospital
illness, oxygen requirements, white blood cell count, bacterial culture results,
number of procedures performed per patient, duration of chest tube drainage,
complications, and length of stay. Kruskal-Wallis 1-way analysis was used, with
significance at P less than .05. RESULTS: A total of 60 children were treated by
M1, 38 by M2, and 41 by M3. Age, duration of prehospital illness, oxygen
requirements, white blood cell count, bacterial culture results, and complication
rates were comparable. The median length of stay was 12 days for M1, 11 days for
M2, and 7 days for M3, with M3 significantly shorter at P<.001. The number of
procedures was a median of 2 in M1, 2 in M2, and 1 in M3, with M3 significantly
fewer at P<.001. Duration of chest tube drainage was a median 5 days for M1 and 3
days for M2 and M3, with M1 significantly longer at P<.001. There were 9
thoracotomies in the M1 group, 3 in the M2 group, and none in the M3 group. One
child in M3 required a second VATS. CONCLUSIONS: Primary VATS has significantly
decreased the number of procedures, duration of chest tube drainage and length of
stay for children with parapneumonic effusions. Primary VATS appears to be of
value in management of bacterial pneumonia with effusion.
PMID- 10693679
TI - Thoracoscopic lung resection in children.
AB - PURPOSE: The aim of this study was to evaluate the technique of video-assisted
thoracic surgery (VATS) in lung resections in infants and children. METHODS: From
December 1992 to December 1998 113 consecutive patients, ages 3 weeks to 19
years, underwent VATS for biopsy or resection of various lung pathology. This
included 88 wedge biopsies, 12 resections of bullous or cystic disease, 9
lobectomies or segmental resections, and 4 bronchogenic cysts. RESULTS: All
procedures were completed successfully. Two patients with metastatic disease had
surgery converted to a standard thoracotomy for extensive resections. The average
operating time for a wedge biopsy of 2 sites was 26 minutes and 210 minutes for a
lobectomy. The average hospital stay after wedge resection was 1.1 days. There
were no complications related to the VATS approach. CONCLUSION: VATS is a safe
and effective technique in the diagnosis and treatment of pediatric pulmonary
disease.
PMID- 10693680
TI - The 'penny pincher': a new technique for fast and safe removal of esophageal
coins.
AB - BACKGROUND/PURPOSE: Considerable debate surrounds the choice of technique for the
removal of esophageal coins: endoscopic extraction versus dislodgement with a
Foley balloon versus dislodgement using bougienage. The "penny-pincher" (PP)
technique was developed as an alternative, incorporating the main advantages of
these various approaches. METHOD: The PP technique is based on the insertion of a
fluoroscopically guided device that consists of a grasping endoscopic forceps
covered by a soft rubber catheter. The forceps provides a firm hold on the coin.
The catheter protects the oropharynx and aligns the device with the coin. Once
the tip of the catheter is close to the upper edge of the coin, the previously
retracted radiopaque prongs of the grasping forceps are deployed and the edge of
the coin firmly grasped and extracted. The procedure is done without anesthesia
or sedation. RESULTS: Twenty coins were removed from 19 consecutive children with
a mean age of 34 months. Average lip-to-lip removal (including fluoroscopy) time
was 41 seconds. There were no complications, and all patients were discharged
shortly after coin removal. CONCLUSION: The penny-pincher method for the removal
of upper esophageal coins combines the simplicity, speed, and cost effectiveness
of balloon catheter or bougie coin dislodgement with the safety and secure
grasping of endoscopic or forceps removal.
PMID- 10693681
TI - Preoperative home care for esophageal atresia--a survey.
AB - BACKGROUND/PURPOSE: Long gap esophageal atresia may require months of
preoperative management before definitive repair. When 2 recent patients prompted
the authors to consider preoperative home care, no published protocol could be
identified. This survey is undertaken to determine pediatric surgeons' experience
with preoperative home care for long gap atresia. METHODS: A total of 543
surgeons were asked if any patients with long gap atresia had been treated
preoperatively at home. For patients sent home, information on nursing care,
insurance issues, complications, and timing or type of repair was requested.
RESULTS: A total of 380 surveys (70%) were returned. A total of 165 surveys
representing 348 patients were included. Forty-one of 165 surgeons (25%) treated
63 of 87 patients (72%) with long gap atresia and an intact upper pouch at home.
Home nursing care was provided for 44 patients (70%): 16 (36.4%) night shift, 2
(4.5%) day shift, 3 (6.8%) 24 hour, and 23 (52.3%) intermittent care. No
complications referable to preoperative home care were reported. CONCLUSIONS:
Significant hesitancy and practice variance exists regarding preoperative home
care of patients with long gap esophageal atresia. Many surgeons are satisfied
with the safety and cost effectiveness of this technique, although a prospective,
multicenter trial is needed to study it in a randomized, controlled fashion.
PMID- 10693682
TI - Split-liver transplantation: a comparison of ex vivo and in situ techniques.
AB - BACKGROUND/PURPOSE: The expanding applicability of liver transplantation as
treatment for end-stage liver disease has fostered a disproportionate increase in
liver transplant candidates in the face of an unchanging pool of donor organs.
This has resulted in disparities in pretransplant waiting times and deaths. The
splitting of a liver allograft allows for the transplantation of 2 recipients,
usually an adult and a child, thus providing a means to expand the cadaveric
donor pool. METHODS: The authors present their results on the performance of an
ex vivo (back table) split and in situ (in a hemodynamically stable cadaveric
donor) split to evaluate safety, applicability, and effectiveness. Between
November 1989 through April 1998, 54 split-liver transplant recipient operations
were performed (24 pediatric and 30 adult). Thirty donors were procured: the ex
vivo splitting yielded 25 grafts from 13 donors (donor age, 24.6+/-11 years), and
the in-situ technique yielded 29 grafts from 17 donors (mean donor age of 25.5+/
10.4 years). Five donors involved interinstitutional sharing for which the left
side of the graft was kept at the host hospital and the right side grafts were
utilized at our center. RESULTS: Overall 1-year patient survival was 85%, with a
graft survival of 72%. Patient survival was similar with ex vivo (74%) as
compared with the in situ splitting group (96%; P = .06), as was graft survival
in ex vivo (61 %) versus in situ (81%) splitting (P = .15). The pediatric
population benefited most from the in situ technique, with a 1-year patient
survival rate of 100% with the in situ technique versus the ex vivo technique
survival rate of 64% at 1 year (P = .02). The 1-year graft survival comparing
these 2 techniques was 83% for the in situ group versus 45% for the ex vivo
group. Analysis of the program evolution of split-liver transplantation suggested
a time-dependent learning curve, which was applicable to surgical splitting
technique, implantation, and recipient selection. CONCLUSIONS: The principle of
splitting livers from cadaveric donors is fundamentally sound and technically
feasible. The authors' outcomes analysis using 2 different procurement techniques
suggests that the in situ technique is clinically efficacious, can be used
alternatively with the ex vivo technique, and is comparable to whole-liver
allograft transplantation.
PMID- 10693683
TI - Composite liver--small bowel allografts with preservation of donor duodenum and
hepatic biliary system in children.
AB - BACKGROUND/PURPOSE: Liver and intestinal transplantation is commonly required for
children with intestinal failure who suffer concomitant total parenteral
nutrition (TPN)-induced liver failure. Retrieval of such composite allografts
using previously described "standard techniques" mandates reconstruction of the
biliary system with a defunctionalization loop of the proximal allograft jejunum.
The occasional posttransplant biliary complications have been associated with
significant morbidity and mortality. Also, size matching has limited the pool of
donor organs for this patient population. To improve outcome and increase the
donor pool the authors have utilized a duodenal-sparing composite liver small
bowel allograft technique (DLSBTx) by preserving the head of the pancreas and the
pancreatic-duodenal arteries. This precludes a biliary drainage procedure.
METHODS: Nine children (5 girls, 4 boys), with a mean age of 1.4 years (range, 1
to 17.4 years) received a DLSBTx. In 2 patients the liver was reduced; 1 patient
received the whole pancreas. The mean recipient weight at the time of
transplantation was 17.4 kg (range, 6.6 to 49.8 kg). The mean age and mean weight
for donors was 7.9 years (range, 3 days to 22 years) and 25 kg (range, 4 to 70
kg), respectively. All transplants were performed under tacrolimus and steroid
immunosuppression. RESULTS: With a mean follow-up of 419 days (range, 5 to 795
days), patient and graft survival rates are 78% and 67%, respectively. One
patient underwent a combined retransplantation with the standard technique 31
days after the primary allograft was destroyed by a native pancreatic fistula.
Currently, all surviving recipients are at home and off TPN. DLSBTx allowed the
expansion of the donor pool by transplanting 6 patients with donor to recipient
weight ratio > or =1 and utilizing 2 less than 5-kg donors, including a neonatal
donor. In 55% of the patients, chemical pancreatitis was observed during the
early postoperative period. None of the duodenal allografts experienced signs of
ischemia or leak. CONCLUSIONS: The technical advantages of this procedure include
avoidance of a biliary reconstruction and simplification of the operative
procedure. This, together with the feasibility of split or reduced liver grafting
promises to increase the donor pool from neonates to adults.
PMID- 10693684
TI - Pediatric recipients of three or more hepatic allografts: results and technical
challenges.
AB - BACKGROUND/PURPOSE: Children who require a liver transplant at an early age risk
chronic allograft rejection (CAR) and other causes of allograft loss. Multiple
retransplants may be required for long-term patient survival. The authors
evaluate this approach based on our results and technical difficulties. METHODS:
Charts of 7 children who received 3 or more liver transplants from 1989 to the
present were reviewed retrospectively. RESULTS: A total of 151 children required
liver transplantation at our institution since 1989. Of these, 4 boys and 3 girls
(mean age, 6.2 years; range, 3 to 14 years) have received 3 or more allografts.
The etiology of liver failure for the penultimate allograft was CAR (n = 6) and
hepatic artery thrombosis (HAT; n = 1). Five cases required modification of
portal vein or hepatic artery anastomoses. Two patients with vena caval
strictures required supradiaphragmatic vena caval reconstruction. The original
Roux-en-Y limb was adequate for biliary reconstruction in all cases. Five
children currently are alive (survival rate, 71%) with good graft function having
had a mean follow-up of 23 months (range, 2 to 48 mos.). CONCLUSIONS: The
operative procedure for the multiple hepatic transplant child is challenging. The
transplant team must be prepared for intraoperative issues such as extended organ
ischemia time during hepatectomy, extensive blood loss, and potential need for
creative organ revascularization techniques. Overall, multiple retransplant
results are good and justify the use of multiple allografts.
PMID- 10693685
TI - Extended left hepatectomy (left hepatic trisegmentectomy) in childhood.
AB - BACKGROUND/PURPOSE: Extended left hepatectomy, also referred to as left hepatic
trisegmentectomy, in which segments II, III, IV, V, and VIII are excised, is
rarely performed in children. Experience with 7 such resections is reported to
describe the anatomy, technique, indications, and outcomes of the operation.
METHODS: The medical records of all pediatric patients treated at our institution
over the last 15 years who underwent extended left hepatectomy were reviewed.
Demographic information as well as operative, pathological, and follow-up data
were analyzed. RESULTS: Seven patients underwent extended left hepatectomy over
this period. There were 5 boys and 2 girls ranging in age between 4 months and 9
years with a median age of 3.1 years. Follow-up ranged from 8 months to 5 years
with a median of 3.5 years. Diagnoses included hepatoblastoma (HB, n = 3), focal
nodular hyperplasia (FNH, n = 1), leiomyosarcoma (LMS, n = 1),
hepatocellularcarcinoma (HCC, n = 1), and metastatic neuroblastoma (NB, n = 1).
All surgical margins were grossly negative. Median operative blood loss was 13
mL/kg (range, 5 to 32 mL/kg), and mean hospital stay was 9 days (range, 7 to 12
days). No major intra- or postoperative complications were encountered, and there
was no perioperative mortality. The 3 HB patients, 1 FNH patient, 1 LMS patient,
and 1 NB patient are without evidence of disease, whereas the 1 child with HCC
died of recurrent and distant disease. The 6 surviving children have normal
hepatic function. CONCLUSION: Although technically challenging and rarely
performed, extended resection of the left hepatic lobe is feasible in children
and can yield curative results with minimal morbidity.
PMID- 10693686
TI - Aggressive surgery is unwarranted for biliary tract rhabdomyosarcoma.
AB - BACKGROUND/PURPOSE: Rhabdomyosarcoma (RMS) of the biliary tract is rare, and, in
addition to multiagent chemotherapy with or without radiotherapy (RT), some
investigators recommend aggressive surgery. To assess the role of surgery,
records of all 25 eligible patients with biliary RMS enrolled in IRSG studies I
through IV from 1972 to 1998 were reviewed. METHODS: Treatment included surgery
with or without vincristine, dactinomycin, cyclophosphamide, doxorubicin,
cisplatin, etoposide, ifosfamide, and with or without RT. Data evaluated included
clinical presentation, treatment, complications, and outcome. RESULTS: Diagnostic
imaging identified the primary tumor but failed to identify regional metastases.
Despite aggressive surgery, gross total resection at diagnosis was possible in
only 6 cases, 2 of which had negative surgical margins. Although only 6 (29%)
patients without distant metastases underwent gross total resection, estimated 5
year survival rate was 78% (95% CI 58%, 97%). Infectious complications were
common and frequently associated with external biliary drains. Five (20%) died
within the first 2 months, 3 of sepsis. CONCLUSIONS: Surgery is critical for
establishing an accurate diagnosis and determining the extent of regional
disease. Gross total resection is rarely possible despite aggressive surgery, and
outcome is good despite residual disease after surgery. External biliary drains
increase the risk of postoperative infectious complications.
PMID- 10693687
TI - Preoperative staging, prognostic factors, and outcome for extremity
rhabdomyosarcoma: a preliminary report from the Intergroup Rhabdomyosarcoma Study
IV (1991-1997).
AB - BACKGROUND: During the fourth Intergroup Rhabdomyosarcoma (RMS) Study (IRS IV,
1991-97), a preoperative staging system was evaluated prospectively for the first
time. The authors evaluated this staging system and the role of surgery in
extremity RMS in contemporary multimodal therapy. METHODS: A total of 139
patients (71 girls; median age, 6 years) were entered in IRS IV with extremity
site RMS. Stage was assigned by the IRSG Preoperative Staging System.
Postsurgical group was determined by tumor status after initial surgical
intervention. Multivariate analysis was performed using all pretreatment factors
that were significant by univariate analysis, including clinical Group (i.e., I
through IV), tumor invasiveness (T1,T2), nodal status (N0,N1), and tumor size (<
or > or =5 cm). Failure-free survival rates (FFS) and survival rates were
estimated using the Kaplan and Meier method. RESULTS: Preoperative staging and
clinical group distribution were as follows: Stage 2, n = 34; Stage 3, n = 73;
Stage 4, n = 32; Group I, n = 31; Group II, n = 21; Group III, n = 54; Group IV,
n = 33. Three-year FFS was 55%, and the overall survival rate was 70%. Eighty
seven patients had either unresectable, gross residual disease (Group III) or
metastases (Group IV). FFS was significantly worse for these patients with
advanced disease, compared with that for patients with complete resection or with
only microscopic residual tumor (i.e., Group I or II; Group I, 3-year FFS, 91%;
Group II, 72%; Group III, 50%; Group IV, 23%; P<.001). Lymph nodes were evaluated
surgically in 76 patients with positive results in 38. Clinically, 13 additional
patients had nodal disease. Both stage and group were highly predictive of
outcome and were highly correlated. By multivariate analysis, none of the other
variables were predictors of FFS. CONCLUSIONS: This review confirms the utility
of pretreatment staging for stratification of patients with extremity RMS with
widely different risks of relapse, thereby paving the way for development of risk
based therapy. Group (operative staging) remains the most important predictor of
FFS, emphasizing the importance of complete gross resection at initial surgical
intervention, when feasible without loss of limb function. The high incidence of
nodal disease in the patients who had lymph node biopsy confirms the need for
surgical evaluation of lymph nodes to ensure accurate staging in children with
extremity rhabdomyosarcoma.
PMID- 10693688
TI - Sonographic prognostic factors in fetuses with sacrococcygeal teratoma.
AB - BACKGROUND: A subset of fetuses with sacrococcygeal teratoma (SCT) develops
hydrops caused by high-output heart failure. Identification of fetuses at risk
for hydrops is important because fetal intervention may reverse the
pathophysiology of the disease. To date, no reliable sonographic prognostic
factors have been identified. METHODS: An experienced sonologist reviewed the
sonographic records of 17 fetuses with SCT referred to the authors' institution.
Size of the tumor was measured and corrected for fetal size. The appearance of
the tumor (solid versus cystic) and its vascularity were graded on a subjective
scale of 1 to 5. RESULTS: Only 4 of 12 fetuses that had hydrops survived; of the
survivors, 3 had undergone fetal intervention. All nonhydropic fetuses survived.
Fetuses with hydrops had tumors that were mainly solid and highly vascular,
whereas nonhydropic fetuses had predominantly cystic tumors with comparatively
less vascularity. There was no significant difference in tumor size between these
2 groups. CONCLUSIONS: Fetuses with SCT that are mainly solid in appearance and
are highly vascularized have a higher risk of getting hydrops in utero. Tumor
size is not an independent prognostic factor.
PMID- 10693689
TI - Testicular damage after surgical groin exploration for elective herniorrhaphy.
AB - BACKGROUND/PURPOSE: Controversy exists whether to explore the contralateral groin
in boys during unilateral herniorrhaphy. Proponents claim there is minimal risk
of injury to the cord structures and developing testicle with contralateral
exploration. However, findings have shown testicular atrophy occurred in 1% to 2%
of patients after herniorrhaphy, and vasal damage is possible after routine
manipulation of the spermatic cord. This study investigated the effect of routine
surgical exploration of the prepubertal groin on testicular development and
future fertility. METHODS: Twenty-four prepubertal Wistar rats were divided
equally into 2 groups. Group 1 (sham) rats underwent unilateral inguinoscrotal
incision only. Group 2 (experimental) rats underwent unilateral inguinoscrotal
exploration with manipulation of the cord structures as in human inguinal
exploration. At maturation, the fertility and fecundity of the males were
assessed. After mating, testes were examined for mass, volume, mean seminiferous
tubule diameter (MSTD), and mean testicular biopsy score (MTBS). The vasa were
examined for histological injury and vasal diameter. Statistical comparisons were
made by paired t test and Mann-Whitney rank sum test. RESULTS: There was a
difference between the volumes of the testes when comparing the operative and
nonoperative side of the 2 groups (experimental, deltavol = -0.063+/-0.123; sham,
deltavol = +0.067+/-0.137; P = .029). There also was a trend toward a smaller
testicular mass when comparing the two sides (experimental, deltamass = -0.045+/
0.101; sham, Amass = +0.048+/-0.123; P = .057) but did not reach significance.
The MSTD and MTBS were similar between the ipsilateral and contralateral testes
in both groups. Likewise, the MSTD and MTBS were similar when comparing the 2
groups. All male rats in both groups were fertile. The number of offspring
produced and the number of female rats impregnated were similar between the 2
groups. There was no histological evidence of vasal injury in any of the
experimental spermatic cords. The vasal diameters were similar between the 2
groups. CONCLUSION: Surgical manipulation of the prepubertal spermatic cord
imparts a small, but statistically significant morphological change in testicular
size without a deleterious effect on testicular development, fertility, or
fecundity.
PMID- 10693690
TI - Alternative method for repair of the difficult infant hernia.
AB - BACKGROUND: Inguinal hernia repair in the small infant is often technically
difficult. An alternative operative approach has been developed that can simplify
troublesome repairs, while decreasing the potential risks of damage to cord
structures and of recurrence. METHODS: Thirteen small infants (weight 1400-3000
grams) underwent inguinal hernia repair using a technique of direct closure of
the internal inguinal ring via a trans-hernial sac approach. Dissection of cord
structures from the sac was avoided. RESULTS: All hernia repairs remained intact
on follow-up of 4-28 months. One patient early in the series developed a
noncommunicating hydrocele, prompting the addition of sac eversion to the
original technique. CONCLUSIONS: An alternative method for simplified repair of
difficult infant hernias has been used with success. While it does not supplant
traditional repair technique for most patients, it should be considered for use
in selected situations.
PMID- 10693691
TI - Laparoscopic fundoplication in children with previous abdominal surgery.
AB - BACKGROUND/PURPOSE: In our institution, many children requiring antireflux
surgery for gastroesophageal reflux have had previous abdominal surgery, usually
gastrostomy tube or ventriculoperitoneal (VP) shunt placement. The authors review
their laparoscopic Nissen fundoplication (LNF) experience in children with
previous abdominal surgery assessing surgical outcome. METHODS: A total of 82
consecutive LNFs performed at our institution between January 1996 and September
1998 were reviewed. Follow-up ranged from 1 month to 32 months (average, 8.9
months). LNF was performed without dividing short gastric vessels (Rosetti
modification) through a standard 5-port technique. RESULTS: A total of 26 of 82
patients (31.7%) had previous abdominal surgery and were divided into 2 groups:
gastrostomy (n = 17) and VP shunt (n = 11) with 2 crossovers. A total of 14 of 17
(82.3%) in the gastrostomy group had percutaneous endoscopic gastrostomy (PEG)
placement versus 3 of 17 (17.6%) by open technique (open). Four patients in the
VP group had multiple surgeries (range, 1 to 10, average, 2.3). LNF was completed
in 25 of 26 (96.2%). One operation was converted to an open procedure because of
severe adhesions. In 13 of 17 (76.5%) the previous gastrostomy was not taken
down. In 4 of 17 (23.5%), the gastrostomy was taken down to complete the
procedure: 2 of 3 (66.7%) of the open group versus 2 of 14 (14.3%) of the PEG
group. All 11 (100%) of the VP group had successful LNF. Two of 11 (18.2%) had
shunt dysfunction at 2 months (shunt infection) and 4 months (clogged distal
shunt), respectively. There have been no cases of recurrent reflux, and all
gastrostomies and VP shunts were functional at the time of this report.
CONCLUSIONS: Previous abdominal surgery is common in children with
gastroesophageal reflux disease requiring an antireflux procedure. The authors
conclude from these preliminary results that laparoscopic Nissen fundoplication
can be performed safely with minimal morbidity and excellent functional results
in children with gastrostomies or ventriculoperitoneal shunts.
PMID- 10693692
TI - Pyloromyotomy versus atropine sulfate for infantile hypertrophic pyloric
stenosis.
AB - PURPOSE: Atropine sulfate (atropine) and pyloromyotomy were compared for managing
infantile hypertrophic pyloric stenosis (IHPS). METHODS: From 1996 to 1998, cases
of IHPS treated surgically (pyloromyotomy; n = 20) or medically (atropine; n =
14) at separate institutions were compared retrospectively with regard to status
on presentation, physical symptoms and signs, progress, and costs. Atropine was
given orally, then intravenously if ineffective. Refractory cases were referred
for pyloromyotomy. RESULTS: All subjects were matched for clinical and
physiological status on admission. Oral atropine alone was effective in 11 cases,
was converted to intravenous atropine in 2 cases, and was terminated in 1 case
because of hematemesis. Two cases were referred for pyloromyotomy. All
pyloromyotomies were successful. Atropine took on average, 2.6 days to take
effect. The difference in time taken for normalization of pyloric muscle
thickness between the 2 groups was not significant. Average time to return to
full feeding was longer in the atropine group (P<.01). Costs were lower in the
atropine group (P<.01). There were 2 wound infections in the pyloromyotomy group,
but no adverse effects of atropine. There were no recurrences in either group.
CONCLUSION: This study provides reasonable evidence to support a trial of
atropine in IHPS.
PMID- 10693693
TI - The modified Puestow procedure for complicated hereditary pancreatitis in
children.
AB - PURPOSE: The aim of this study was to evaluate the role of longitudinal
pancreaticojejunostomy (modified Puestow procedure) in the treatment of
complicated hereditary pancreatitis (HP) in children. METHODS: The authors
reviewed their experience with the modified Puestow procedure for complicated HP
in patients less than 18 years of age at a single tertiary care facility between
1973 and 1998. Main study outcomes included surgical morbidity and mortality, pre
and postoperative pancreatic function, number of hospitalizations, and
percentile ideal body weight (IBW). RESULTS: Twelve patients (6 boys and 6 girls)
with a mean age of 9.3 years were identified. Presenting diagnoses were abdominal
pain (n = 10), failure to thrive (n = 4), pancreatic pleural effusion (n = 2),
and pancreatic ascites (n = 1). Blood loss was greater in patients who underwent
distal pancreatectomy to localize the duct (n = 6) than in those who underwent
direct transpancreatic duct localization (n = 6; 29.1+/-6.8 v. 8.3+/-3.7 mL/kg; P
= .03). Other complications in patients who underwent distal pancreatectomy
included splenic devascularization requiring splenectomy (n = 1) and
postoperative intraabdominal bleeding with subsequent left subphrenic abscess (n
= 1). There was no surgical mortality. Five patients had steatorrhea
preoperatively that resolved in 4 patients postoperatively and was well
controlled in the fifth. Mean number of hospitalizations for pancreatitis in the
5 years after surgery were markedly less than in the 5 years preceding surgery
(0.4+/-0.2 v. 3.5+/-0.5; P = .01, n = 9). Percentile ideal body weight tended to
increase within the first postoperative year (24.6+/-6.8 v. 45.0+/-8.3; P = .07,
n = 9), and by the third year this trend was clearly significant (27.0+/-7.2 v.
60.9+/-9.5; P = .01, n = 8). CONCLUSIONS: In children with complicated HP, the
modified Puestow procedure improves the quality of life by improving pancreatic
function, decreasing hospitalizations, and increasing the percentile ideal body
weight. Direct pancreatic duct localization during the procedure had a lower
morbidity rate than localization via distal pancreatectomy. It is our impression
that surgery performed in the early stage of complicated disease may preserve
pancreatic function.
PMID- 10693694
TI - T-tube ileostomy for meconium ileus: four decades of experience.
AB - BACKGROUND/PURPOSE: The T-tube ileostomy was first used at Texas Children's
Hospital in 1959. The purpose of this study is to update the experience since the
initial report of this technique in 1981. METHODS: A database of 448 patients
with cystic fibrosis (CF) seen in the authors' institution was used to identify
83 patients (18.5%) who presented with meconium ileus. The clinic and hospital
charts of these patients were reviewed retrospectively to identify patients who
had undergone placement of a T-tube ileostomy. RESULTS: Surgery was performed in
60 of 83 patients for complications of meconium ileus or failure to evacuate the
meconium after a contrast enema. Of these patients, 21 of 60 (35%) underwent
placement of a T-tube ileostomy. An additional 8 patients were identified who
underwent placement of a T-tube ileostomy but were not included in the CF
database, for a total of 29 patients who have been treated with T-tube ileostomy
since 1959 at Texas Children's Hospital. Five patients were excluded from
analysis because of insufficient data or misdiagnosis. One of the 24 patients in
the series died of complications of prematurity. A total of 20 of 23 patients had
resolution of their meconium ileus after T-tube irrigation with n-acetylcysteine
or pancreatic enzymes. Three patients required additional surgery to relieve
persistent bowel obstruction. All patients had the T-tube removed within the
first 8 weeks after surgery. Two patients required subsequent repair of an
incisional hernia. There were otherwise no complications of this procedure, with
an average follow-up of 11.5 years. CONCLUSION: In patients with uncomplicated
meconium ileus unrelieved by contrast enema, the T-tube ileostomy is an effective
and safe treatment.
PMID- 10693695
TI - A novel technique for correction of intestinal atresia at the ligament of Treitz.
AB - PURPOSE: After reconstruction of jejunal atresias at the ligament of Treitz, many
patients do not respond to simple tapering and anastomosis requiring repetitive
operations because of dysfunction of dilated proximal bowel. A new operative
approach using lateral duodenectomy and duodenojejunostomy (LDAD) is reported.
METHODS: Three infants with atresias within 10 cm of the ligament of Treitz were
treated with LDAD, and their records are reviewed retrospectively. The entire
duodenum is visualized after creating a malrotation; this is followed by opening
the dilated duodenum and resecting dilated proximal jejunum. The resection is
extended proximally, incorporating the lateral duodenal incision, excising the
lateral duodenal wall, and preserving the ampulla. The residual duodenum is
fashioned into a tube and anastomosed to the spatulated distal jejunum. RESULTS:
Three infants underwent this procedure over a 4-year period. Two had undergone
tapering enteroplasties previously but were unable to tolerate oral feedings; 1
infant had LDAD primarily. All were ultimately successfully managed by LDAD and
were feeding within 14 days. Follow-up is from 14 to 49 months. CONCLUSION:
Although experience is limited to 3 patients, the prompt return of intestinal
function with LDAD may justify primary use of this more radical procedure in
difficult-to-treat proximal atresias.
PMID- 10693696
TI - Glucagonlike peptide-2 analogue enhances intestinal mucosal mass after ischemia
and reperfusion.
AB - BACKGROUND/PURPOSE: Glucagonlike peptide-2 (GLP-2), a product of the
posttranslational processing of proglucagon, has been shown to enhance mucosal
mass and function in both normal intestine and in the residual intestine after
massive small bowel resection. This study was designed to determine if a
synthetic, protease-resistant analogue of GLP-2 (GLP-2alpha) can enhance mucosal
mass in small intestine after ischemia and reperfusion (I/R) injury. METHODS: Ten
young adult male Sprague-Dawley rats underwent laparotomy and superior mesenteric
artery occlusion for a period of 40 minutes. During this period of ischemia, each
rat underwent placement of a jugular venous catheter that was connected to a
subcutaneously placed osmotic pump designed to deliver its contents over 3 days.
The rats were divided into 2 groups based on the contents of the pumps: group 1,
saline at 1 microL/h (n = 6) and group 2, GLP-2alpha at 100 microg/kg/d (n = 4).
Three days after insertion of the pumps the small intestine was harvested from
the surviving rats for determination of mucosal DNA and protein content.
Statistical analysis was performed using unpaired Student's t test. RESULTS:
After I/R injury to the small intestine, a 3-day systemic infusion of GLP-2alpha
significantly increased mucosal DNA content 41% (P<.05) and mucosal protein
content 60% (P<.05) when compared with saline-treated controls. In addition,
infusion of GLP-2alpha reduced mortality from 50% to 25%. CONCLUSIONS: These data
show for the first time that GLP-2alpha enhances mucosal mass following I/R
injury to the small intestine. GLP-2alpha may be of benefit to patients with
intestinal ischemia syndromes such as necrotizing enterocolitis and midgut
volvulus.
PMID- 10693697
TI - Hormonal therapy for short bowel syndrome.
AB - PURPOSE: Treatment of short bowel syndrome (SBS) can be difficult; this study
examines the effect of parental administration of different peptide hormones in a
rat model of SBS. METHODS: Juvenile male Lewis rats (220 to 240 g) underwent
resection of the proximal 90% of small bowel and were assigned randomly to
treatment groups: growth hormone (GH), insulinlike growth factor-1 (IGF-1),
glucagonlike peptide-2 (GLP-2; given as ALX-0600, a potent protease resistant
analogue of the human GLP-2), control-resected (Con-R), or control-transected
(Con-T). Drugs were delivered by continuous subcutaneous infusion via Alzet mini
pumps: controls received equivalent volumes of drug vehicle. Animals were pair
fed (23 g chow per day) and followed up for 14 days monitoring weight gain.
Animals were killed and active transport, hormone profiles, and intestinal
morphology were assessed. RESULTS: Hormonal treatments significantly increased
weight gain in all groups (GH, 9.9+/-4.9; IGF-1, 6.0+/-9.6; and GLP-2, 0.8+/-2.7
v. -6.2+/-4.7 in untreated resected animals [weight as percentile initial
weight]). This was associated with a significant alteration in intestinal
morphology in the IGF-1-treated animals, and an increase in glucose transport
rates in all hormonally treated animals when compared with untreated control
resected animals. CONCLUSIONS: These results show that IGF-1, GH, and GLP-2 all
improve short-term weight gain after massive bowel resection in a rat model. The
effects seen on weight gain may be caused by improved dietary nutrient absorption
from an increase in the intestinal surface area or increase in transporting
activity or alterations in the metabolic efficiency of the animal. These findings
suggest further studies of these therapies as treatment for short-bowel syndrome
are indicated.
PMID- 10693698
TI - Intestinal adaptation occurs independent of transforming growth factor-alpha.
AB - BACKGROUND/PURPOSE: Signal transduction via the epidermal growth factor receptor
(EGFR) is critical for intestinal adaptation after massive small bowel resection
(SBR). Although it has been assumed that the major ligand for the EGFR during
adaptation is EGF, the role for transforming growth factor-alpha (TGF-alpha),
another major ligand for the EGFR is unknown. The purpose of this study was to
test the hypothesis that TGF-alpha is an important ligand for the EGFR during
intestinal adaptation. METHODS: Wild-type mice (C57BI/6) underwent a 50% proximal
SBR or sham operation (bowel transection or reanastomosis) and were then assigned
randomly to receive either intraperitoneal TGF-alpha or placebo. In a separate
experiment, SBR or sham operations were performed in mice lacking TGF-alpha
(Waved-1). After 3 days, adaptation was measured in the ileum. RESULTS: Exogenous
TGF-alpha enhanced intestinal adaptation in the wild-type mice after SBR as shown
by increased ileal wet weight and DNA content. Normal adaptation occurred in the
mice lacking TGF-alpha as shown by increased ileal wet weight, protein and DNA
content, proliferation, villus height, and crypt depth. CONCLUSIONS: Although
exogenous TGF-alpha enhanced adaptation after massive SBR, adaptation was
preserved in TGF-alpha-absent mice. These results refute TGF-alpha as an
essential ligand for EGFR signaling during intestinal adaptation.
PMID- 10693699
TI - Interleukin-11 enhances small intestine absorptive function and mucosal mass
after intestinal adaptation.
AB - BACKGROUND/PURPOSE: Interleukin-11 (IL-11) recently has been shown to enhance
mucosal mass after massive small bowel resection (MSBR). However, enhanced
mucosal mass may not correlate with increased substrate absorption. This study
was designed to examine the effect of systemic administration of increasing doses
of IL-11 on small intestine absorptive function and mucosal mass after MSBR.
METHODS: Twenty-five Sprague-Dawley rats underwent an 80% small bowel resection
and end-to-end jejunoileal anastomosis. Seven days after resection, all rats had
placement of a jugular venous catheter connected to a subcutaneously placed
osmotic pump. The rats were divided into 5 groups based on the content of the
pump: group 1 (control, n = 5) received 0.1% bovine serum albumin (BSA) and
groups 2 through 5 (n = 5 each) received IL-11 at 250, 500, 750, and 1,000
microg/kg/d, respectively. After a 14-day infusion period, [14C] galactose and
[14C] glycine absorption was measured using an in vivo closed-recirculation
technique. Mucosal DNA content also was determined for each group. Statistical
analysis was performed by analysis of variance and expressed as mean +/-SEM.
RESULTS: IL-11 administered at 250 microg/kg/d, a dose used in previous studies,
did not significantly affect substrate absorption. However, compared with the
control group, administration of higher doses of IL-11 produced a significant
increase in substrate absorption and mucosal mass. The dose of IL-11 producing
the overall optimal response based on the parameters measured (galactose
absorption, 72% increase over control; glycine absorption, 112% increase over
control; and DNA content, 98% increase over control) was 750 microg/kg/d.
CONCLUSIONS: In addition to an increase in mucosal mass, these data show for the
first time that IL-11 enhances absorptive function beyond the normal adaptive
response after MSBR. Furthermore, the maximum effect of IL-11 on absorptive
function was shown at 750 microg/kg/d, which is 3 times the dose used in
previously reported studies. This study suggests that IL-11 may be useful
clinically in patients with inadequate intestinal function.
PMID- 10693700
TI - Overexpression of Fas-ligand by neuroblastoma: a novel mechanism of tumor-cell
killing.
AB - BACKGROUND/PURPOSE: Binding of Fas ligand (Fas-L) to the membrane-bound Fas
receptor incites a series of intracellular events that results in programmed cell
death or apoptosis. Although this apoptotic phenomenon plays a key role in down
regulating cytotoxic T cells, the authors have shown previously that pancreatic
beta cells (bTC) overexpressing Fas-L paradoxically undergo accelerated rejection
that is dependent on a Fas/Fas-L interaction. This study evaluates whether a
neuroblastoma (NB) cell line manipulated to overexpress Fas-L undergoes similar
destruction and whether tumor-specific protective immunity can be produced.
METHODS: The authors transfected NB cells (SK-N-MC) with either mFas-L cloned
into a pcDNA3.1/Zeo plasmid vector (NB/Fas-L) or with the vector alone
(NB/control). Successful transfection of Fas-L was characterized by reverse
transcription polymerase chain reaction (RT-PCR) and the ability of transfectants
to induce apoptosis of Fas-sensitive T cells (Jurkat). Expression of Fas and Fas
L in untransfected NB clones was characterized by immunohistochemistry and RNase
protection assay (RPA). Apoptosis was measured by FACScan analysis using an
Annexin V assay. A total of 3x10(6) NB/control and NB/Fas-L cells were implanted
subcutaneously into the hind leg of Balb/C SCID mice. Tumor-specific protective
immunity was also tested in this model by inoculating mice with NB/Fas-L before
implanting NB/control cells. RESULTS: Zeocin resistance and RT-PCR confirmed
successful transfection of Fas-L into NB cells. Fas Ligand transfectants induced
apoptosis in 17.6%+/-2.9% of Fas-sensitive T cells, whereas controls induced
apoptosis in only 2.8%+/-1.2% (P = .01, n = 3). Although Fas appears to be
constitutively expressed by NB in low amounts, introduction of Fas-L into NB
cells did not induce suicide or affect tumor cell growth in vitro. In vivo, NB
cells expressing Fas-L failed to grow in SCID mice (n = 3), whereas controls grew
rapidly in all animals until death (n = 3). NB/control cells implanted into the
opposite leg of mice that rejected initial NB/Fas-L transfectants also grew
rapidly (n = 3) implying no protective immunity. CONCLUSIONS: Overexpression of
Fas-L in NB clones targets such cells for rapid destruction even in immune
compromised hosts, suggesting potential utility of Fas-L in combating NB. In this
SCID mouse model, the observed effect is probably neutrophil mediated and does
not provide tumor-specific protective immunity.
PMID- 10693701
TI - Coordinated interdisciplinary management of pediatric intestinal failure: a 2
year review.
AB - BACKGROUND/PURPOSE: Intestinal failure is a complex metabolic process that
results from malabsorption and malnutrition and provides challenges for a variety
of pediatric subspecialists. The purpose of this study was to evaluate the effect
of coordinated interdisciplinary team management of children with intestinal
failure on nutritional outcome measures. METHODS: The Intestinal Care Center
(ICC) is staffed with an interdisciplinary team of pediatric specialists
including a gastroenterologist, pediatric surgeon, transplant surgeon, clinical
dietitians, and a nutrition support nurse. Using an established registry, the
authors conducted a comprehensive evaluation of patient data including
anthropometric measures, organ system function, and mode of nutrition support.
Disease-associated complications including micronutrient deficiencies, growth
delay, and death also were monitored. Nutritional outcome was assessed by
transition from enteral to oral feeding, cessation of total parenteral nutrition
(TPN), and maintenance of linear growth. RESULTS: Since the inception of the ICC
in 1996, 103 patients (69 boys, 34 girls) with intestinal failure have been
evaluated with a median age of 2.6 years (range, 0.2 to 21.3 years). Mode of
nutritional therapy on initial consultation included TPN (n = 76, 74%), enteral
feedings (n = 6, 6%) and oral intake (n = 21, 20%). After intensive management of
the 76 patients who were TPN dependent, 22 (29%) subsequently have been weaned
from TPN (duration, 0.2 to 17.5 years) to oral (n = 14), oral-enteral (n = 4) or
enteral feedings (n = 4). Of the 6 patients who were receiving enteral feedings,
4 (67%) were transitioned to oral feedings. Sixty-eight patients (66%) had
evidence of hepatic disease. Of these, 10 underwent transplant, and 23 died (2
posttransplant). Linear growth velocity of neither pre- nor postpubescent
patients significantly improved during the 2-year study period. CONCLUSION: Data
registry establishment and concurrent interdisciplinary team management of
children with intestinal failure provides for innovative treatment approaches and
a foundation for retrospective or prospective assessment of children with
disease.
PMID- 10693702
TI - Radiofrequency thermal ablation: a potential treatment for hydropic fetuses with
a large chest mass.
AB - BACKGROUND/PURPOSE: Physiological changes secondary to a rapidly enlarging fetal
chest mass can lead to nonimmune hydrops, which is a predictor of impending fetal
demise. Currently, open fetal surgery is offered for specific patients with
hydrops before 32 weeks' gestation. The authors asked if a less-invasive
technique, radiofrequency thermal ablation (RTA), could be applied safely to the
destruction of fetal lung tissue. METHODS: Time-dated pregnant ewes at 120 to 125
days' gestation (term, 140 to 145 days) underwent RTA through a hysterotomy (n =
3) or in a transuterine fashion under ultrasound guidance (n = 4). The probe is a
15-gauge needle with a maximal 2-cm deployment sphere at its tip. By varying the
intensity and duration of treatment, the power settings were optimized to create
a defined area of ablation with minimal surrounding tissue injury. Five of the 6
fetal lambs were killed acutely, and 1 was followed up for 1 week with frequent
ultrasound examinations. RESULTS: Gross examination of the animals killed acutely
showed a consistent area of ablation using 10 watts of applied power for 3
minutes. Direct coagulation necrosis lesions ranged from 1x1 cm to 2x2 cm in size
depending on the extent of the probe deployment. One animal was followed up for 1
week and showed no major adverse physiological effects. CONCLUSION:
Radiofrequency thermal ablation can be performed safely in this fetal sheep model
to create a controlled area of lung tissue ablation.
PMID- 10693703
TI - Differential apoptosis gene expression in pediatric tumors of the kidney.
AB - BACKGROUND/PURPOSE: Apoptosis, or programmed cell death, is essential in
maintaining normal homeostasis of tissues. The process of apoptosis is controlled
by numerous pro- and antiapoptotic factors. Variations in expression of such
factors may account for some variations in tumor behavior. This study evaluates
the expression of apoptotic mRNA species in pediatric renal tumors to determine
whether a pattern of differential apoptosis gene expression correlates with tumor
grade and type. METHODS: Twenty-five frozen tissue specimens were obtained from
patients undergoing biopsy or resection of pediatric renal tumors before
chemotherapy: Wilms' tumor stage II (WT-II, n = 4); Wilms' tumor stage III/IV (WT
III/IV, n = 4); clear cell sarcoma of the kidney stage III (CCSK, n = 2);
rhabdoid tumor of the kidney stage III/IV (RTK, n = 4); and normal kidney (NK, n
= 11). An RNase Protection Assay (RPA) was performed for 19 pro- and
antiapoptotic mRNA species to detect and quantify expression (percentage of GAPDH
expressed). Expression of specific mRNAs of interest were confirmed by Western
Blot (WB). RESULTS: The expression of apoptotic mRNA species varied markedly
between tumors. WT-II expressed greater amounts of proapoptotic receptor mRNA
than CCSK or RTK. (Fas, 17.0+/-2.7% v. 2.5+/-0.5% v. 3.3+/-0.9%; P<.02; DR5,
77.0+/-8.8% v. 13.5+/-0.5% v. 27.0+/-4.8; P<.001; TNF-R, 71.3+/-17.0% v. 21.0+/
4.0% v. 29.0+/-5.0%; P<.07, respectively). Surprisingly, antiapoptotic factors
(e.g., bcl-2 and bcl-xl) were not overexpressed in poor prognostic tumors (CCSK,
RTK) compared with those with good prognosis (WT). Expression of TRAIL (a ligand
for DR4 and DR5) was significantly lower in CCSK and RTK than in normal kidney
(9.5+/-1.5% v. 56.1+/-10.1%; P = .01). CONCLUSIONS: Proapoptotic receptors are
expressed at greater levels in good prognostic tumors, and this finding is
compatible with their clinical behavior. Knowledge of differential apoptotic gene
expression is of potential value in predicting prognosis and treating such tumors
with targeted ligands.
PMID- 10693704
TI - Pancreatitis caused by duodenal duplication.
PMID- 10693705
TI - Outcome analysis for gastroschisis.
PMID- 10693706
TI - Prolonged intestinal exposure to amniotic fluid does not result in peel formation
in gastroschisis.
PMID- 10693707
TI - Quality improvement for diagnostic neuroangiography and other procedures.
PMID- 10693708
TI - Animal models for atherosclerosis, restenosis, and endovascular graft research.
AB - Animal models have significantly advanced our understanding of the mechanisms of
atherosclerosis and restenosis formation and the evaluation of therapeutic
options. The current focus of research is on preventive strategies against
restenosis and includes pharmacologic and biologic interventions directed
primarily against smooth muscle cell proliferation, endovascular devices for
recanalization and/or drug delivery, and an integrated approach using both
devices and pharmacobiologic agents. Devices aimed at the percutaneous
endoluminal exclusion of aortic aneurysms have also generated interest recently.
The experience over many decades with animal models in vascular research has
established that a single, ideal, naturally available model for atherosclerosis,
restenosis, or for that matter aneurysm formation, does not exist. Presently,
rabbits and pigs are favored for the former two areas of study, and dogs and
sheep appear to provide suitable models for testing devices for endoluminal
repair of aneurysms. The development of transgenic variants of currently
available models may widen our options in the future. Nevertheless, an
appreciation of the individual features of natural or stimulated disease in each
species is of the utmost importance for the proper design and execution of
relevant experiments.
PMID- 10693709
TI - Regulatory and legal implications of modifying FDA-approved medical devices.
PMID- 10693710
TI - Management of patient skin dose in fluoroscopically guided interventional
procedures.
AB - PURPOSE: To simulate dose to the skin of a large patient for various operational
fluoroscopic conditions and to delineate how to adjust operational conditions to
maintain skin dose at acceptable levels. MATERIALS AND METHODS: Patient entrance
skin dose was estimated from measurement of entrance air kerma (dose to air) to a
280-mm water phantom for two angiographic fluoroscopes. Effects on dose for
changes in machine floor kVp, source-to-skin distance, air gap, electronic
magnification, fluoroscopic dose rate control settings, and fluorographic dose
control settings were examined. RESULTS: Incremental changes in operational
parameters are multiplicative and markedly affect total dose delivered to a
patient's skin. For long procedures, differences in doses of 8 Gy or more are
possible for some combinations of operational techniques. CONCLUSIONS: Effects on
skin dose from changes in operational parameters are multiplicative, not
additive. Doses in excess of known thresholds for injury can be exceeded under
some operating conditions. Adjusting operational parameters appropriately will
markedly reduce dose to a patient's skin. Above all other operational factors,
variable pulsed fluoroscopy has the greatest potential for maintaining radiation
exposure at low levels.
PMID- 10693711
TI - Lower extremity arteriography with use of iodinated contrast material or
gadodiamide to supplement CO2 angiography in patients with renal insufficiency.
AB - PURPOSE: To determine if the use of nonionic contrast material, as compared to
the use of gadodiamide to supplement carbon dioxide angiography in patients with
peripheral vascular disease (PVD) and chronic renal insufficiency (CRI), results
in significant worsening of renal function. MATERIALS AND METHODS: Lower
extremity angiographic procedures (diagnostic and diagnostic/intervention) were
performed in 40 patients with CRI (baseline serum creatinine [Cr] > 1.5 mg/dL)
using CO2 alone or CO2 supplemented with the use of either nonionic contrast
material or gadodiamide (up to 0.4 mmol/kg). Serum creatinine levels were
obtained before the procedure and at 48 hours after the procedure. The peak Cr
level was also determined for patients with a significant (> 0.5 mg/dL) Cr
elevation. RESULTS: Forty-two lower extremity angiographic procedures (19
diagnostic and 23 diagnostic/interventions) were performed in 40 consecutive
patients from August 1997 to October 1998, with a mean preprocedure Cr of 2.2
mg/dL and a mean postprocedure Cr of 2.4 mg/dL. Twenty-five of the 40 patients
(63%) had diabetes mellitus. Fifteen procedures, including six interventions,
were performed utilizing CO2 and nonionic contrast material in 15 patients. Six
of these 15 patients (40%) demonstrated a Cr increase > 0.5 mg/dL at 48 hours.
Seven procedures, including two interventions, were performed with CO2 alone in
seven patients. No patients in this group demonstrated an increase in serum
creatinine of greater than 0.5 mg/dL at 48 hours. Twenty procedures, including 15
interventions, were performed with CO2 and gadodiamide in 18 patients. In one of
these 20 procedures (5%) there was an increase in Cr > 0.5 mg/dL at 48 hours The
difference in worsening renal function for the nonionic contrast group (six of
15) compared with the CO2/gadodiamide group (one of 20) was statistically
significant (P = .03). When comparing the use of CO2 and nonionic contrast
material versus CO2 alone and with gadodiamide (six of 15 versus one of 27), the
difference is also statistically significant (P < .01). The average volume of
supplemental contrast material was similar in the nonionic contrast material and
gadodiamide groups, as was the average volume of supplemental nonionic contrast
material in the six patients with an increased Cr. CONCLUSION: The use of small
volumes of nonionic contrast material to supplement CO2 angiography in patients
with PVD and CRI can be associated with a significant increased risk of worsening
renal function when compared to angiography performed with CO2 alone or CO2 and
gadodiamide.
PMID- 10693712
TI - Safety of short stay observation after peripheral vascular intervention.
AB - PURPOSE: To determine whether short observation periods (less than or equal to 4
hours) are safe in outpatients undergoing arterial peripheral vascular
interventions. MATERIALS AND METHODS: A retrospective review of 203 patient
medical records from the Interventional Vascular Department for 239 lower
extremity or abdominal procedures (161 men and 78 women) during a 5-year period
was completed. The average patient age was 62.2 years (range, 32-83 years).
Thirty-six patients had more than one procedure. Indication, intervention,
coagulation status, complication rate, and hospitalizations within 7 days after
discharge from the short stay unit (SSU) were reviewed and the outcome was
measured. Patients were grouped according to the length of their observation
period (< or =4 hours or >4 hours) for statistical analysis. RESULTS: In 85% of
the procedures (204 procedures), claudication was the primary indication for
intervention. Angioplasty (203 procedures) was also commonly performed. Ninety
procedures (38%) required stent placement, and other interventional procedures
performed were pulse-spray thrombolysis (eight procedures), atherectomy (two
procedures), and stent-graft placement (one procedure). None of the patients
required hospitalization as a result of their radiologic intervention within 7
days after discharge from the SSU. Specifically, there were no major "at home"
complications in patients discharged after an observation period of < or =4
hours. Two patients were admitted for outpatient procedures and were subsequently
hospitalized as a result of a complication from the procedure. The complication
rate (including minor complications) was 8% (seven of 87) in the < or =4 hour
observation period group compared with 24.3% (37 of 152) in the >4 hour group (P
< .01). This difference was due to a greater number of minor hematomas in the >4
hour group. CONCLUSION: Based on the authors' findings, many interventional
vascular procedures can be performed safely on an outpatient basis with
relatively short observation times. Early discharge from the SSU did not result
in an increased readmission rate to the hospital because of delayed
complications.
PMID- 10693713
TI - Exercise-induced external iliac artery intimal fibrosis: confirmation with
intravascular ultrasound.
PMID- 10693714
TI - Retrograde catheterization of the inferior mesenteric artery to treat endoleaks:
anatomic and technical considerations.
PMID- 10693715
TI - Use of transjugular intrahepatic portosystemic shunts during lytic therapy of
extensive portal splenic and mesenteric venous thrombosis: long-term follow-up.
PMID- 10693716
TI - Transcatheter arterial embolization of ruptured pseudoaneurysms with coils and n
butyl cyanoacrylate.
AB - PURPOSE: To evaluate the clinical efficacy of transcatheter arterial embolization
with n-butyl cyanoacrylate (NBCA) for ruptured pseudoaneurysms, which are
difficult to control by coil embolization alone. MATERIALS AND METHODS: Ruptured
pseudoaneurysms developed at the celiac trunk (n = 1), gastroduodenal artery (n =
2), pancreatic arcade (n = 1), hepatic artery (n = 3), renal artery (n = 1), and
intercostal artery (n = 1) in nine patients. NBCA was mixed with iodized-oil
(1:2) and injected via the 3-F microcatheter under fluoroscopic guidance, after
the catheter was advanced close to the pseudoaneurysm. Coil embolization was
performed to control blood flow before administration of NBCA in seven patients.
NBCA was injected immediately after coil embolization in four patients.
Embolization with NBCA was performed for recurrent bleeding that occurred within
1-21 days (mean, 10.7 days) after initial coil embolization in three patients.
Two patients with peripheral pseudoaneurysms underwent embolization with NBCA
alone. RESULTS: The NBCA mixture was visible under fluoroscopy, and was useful in
monitoring the embolization process and deciding the endpoint. Embolization was
technically successful without major complications in all patients.
Pseudoaneurysms and afferent and efferent arteries were eliminated immediately
after embolization. Bleeding was stopped after embolization in all cases.
Rebleeding did not occur in any patient during their follow-up periods of 0.7
69.5 months (mean, 17.9 months). CONCLUSION: Embolization with NBCA is a feasible
and useful treatment for ruptured pseudoaneurysms, which are difficult to control
by coil embolization alone.
PMID- 10693717
TI - Gunther Tulip filter: preliminary clinical experience with retrieval.
AB - PURPOSE: The Gunther Tulip filter is a permanent filter that has a hook to permit
retrieval. The authors report their preliminary clinical evaluation of the filter
with regard to feasibility and safety of retrieval. MATERIALS AND METHODS: Nine
men and six women who ranged in age from 17 to 79 years (mean, 51 years)
underwent treatment with use of the Gunther Tulip filter. Patients judged to
require caval interruption for < 14 days were selected to receive the filter and
retrieval was planned for all patients. Indications for filter placement were:
recent pulmonary embolism (PE) or proximal deep vein thrombosis (DVT) with a
contraindication to anticoagulation (11 patients), massive PE treated with
thrombolytic therapy (one patient), PE with heparin-induced thrombocytopenia (one
patient), and prophylaxis after major trauma (two patients). Patients were
followed for inferior vena cava (IVC) thrombosis, bleeding, and recurrent DVT or
PE. RESULTS: In all nine patients in whom it was attempted, the filter was
successfully snared and retrieved via a jugular approach. The mean implantation
period was 8.6 days (range, 5-13 days). Retrieval required 2.2-13 minutes (mean
5.3 minutes) of fluoroscopy. No caval injuries occurred as a result of retrieval.
All retrieved filters had strands of organized thrombus on the filter struts. The
patients were followed for 52-285 days (mean, 115 days) after retrieval. One
patient developed a recurrent DVT 230 days after retrieval. No other patients
developed a recurrent DVT and no patients developed IVC thrombosis, bleeding, or
PE. Six filters were not retrieved: five because of an ongoing contraindication
to anticoagulation and one because the patient died of causes unrelated to the
filter. CONCLUSION: This preliminary study confirms the feasibility and safety of
retrieval of the Gunther Tulip filter up to 13 days after implantation.
PMID- 10693718
TI - Current practice of temporary vena cava filter insertion: a multicenter registry.
AB - PURPOSE: To evaluate the current practice of temporary vena cava filter placement
and its complications. MATERIALS AND METHODS: A multicenter registry was
conducted from May 1995 until May 1997 using a standardized questionnaire. One
hundred eighty-eight patients were evaluated. Patient characteristics, filter
indications, filter characteristics, and complications were registered. RESULTS:
Deep vein thrombosis was proven in 95.2% of the patients. Main filter indication
was thrombolysis therapy (53.1%). Average filter time was 5.4 days. An Antheor
filter was inserted in 56.4%, a Guenther filter in 26.6%, and a Prolyser filter
in 17.%. Transfemoral filter implantation was slightly preferred (54.8%). Four
patients died of pulmonary embolism (PE) during filter protection. Major filter
problems were filter thrombosis (16%) and filter dislocation (4.8%). When
thrombus was found in or at the filter before explantation, additional
thrombolysis was performed in 16.7%, additional filter implantation in 10%, and
thrombus aspiration in 6.7%; 4.8% of filters were replaced with permanent
filters. DISCUSSION: Temporary vena cava filters are placed to prevent PE in a
defined patient population. Despite their presence, PEs still occur in a small
percentage. Problems of filter thrombosis and dislocation have to be solved.
CONCLUSION: The results of this multicenter registry support the need for
innovative filter design, as well as a randomized, prospective study.
PMID- 10693719
TI - Balloon dilation and endobronchial stent placement for bronchial strictures after
lung transplantation.
AB - PURPOSE: To evaluate the effect of balloon dilation and endobronchial stent
placement for bronchial fibrous stenoses and bronchomalacia after lung
transplantation. MATERIALS AND METHODS: Bronchial dilation and/or stent placement
was performed on 25 lung transplant recipients. Indications included severe
dyspnea with postobstructive pneumonia (n = 24) and respiratory failure (n = 1).
All patients underwent pulmonary function testing (PFT) before and after
bronchial dilation, the results of which were evaluated for changes. A total of
63 procedures were performed between February 1996 and December 1998. Thirty-five
lesions were treated (18 were due to bronchomalacia, 17 were due to fibrosis).
Areas treated included the left mainstem bronchus (n = 11), bronchus intermedius
(n = 10), right mainstem bronchus (n = 7), left upper lobe bronchus (n = 4),
right lower lobe bronchus (n = 2), and right middle lobe bronchus (n = 1).
Bronchoscopic and/or bronchographic follow-up ranged from 1 to 34 months (mean,
15 months). RESULTS: Six-month primary patency of stents placed for
bronchomalacia was 71% (10 of 14), with three of the four occlusions caused by
mechanical failure of Palmaz stents in the mainstem bronchi. Six-month primary
patency for treatment of fibrous strictures was 29%. Secondary patency at 1 year
was 100% for both bronchomalacia and fibrous strictures. After treatment, there
was a significant improvement in mean PFT results (P = .01-.0001). There was one
acute complication, obstruction of the left lower lobe bronchus by a Wallstent
treated by dilating a hole in the side of the stent. CONCLUSIONS: Balloon
dilation and stent placement are safe and effective for bronchial strictures and
bronchomalacia after lung transplantation, resulting in significant improvement
in PFT results. However, there is almost universal restenosis in patients treated
for fibrous strictures necessitating reintervention for prolonged patency.
PMID- 10693720
TI - US and fluoroscopic-guided percutaneous jejunostomy: experience in 49 patients.
AB - PURPOSE: To assess the feasibility and safety of a variety of techniques for
percutaneous jejunostomy. MATERIALS AND METHODS: Percutaneous jejunostomy was
attempted on 53 occasions in 49 patients under US and fluoroscopic guidance.
During the study period, thicker needles, Cope anchors, and intravenous glucagon
were introduced to improve access, dilate, and immobilize the jejunum. Technical
success rates, complications, catheterization period, and reasons for catheter
removal were prospectively studied. Prognostic factors for successful procedures
and complications were determined. RESULTS: Forty-six (87%) procedures were
technically successful. Previous gastrointestinal surgery (P = .01) and a
combination of thicker needles, Cope anchors, and intravenous glucagon (P =
.0001) were associated with a higher technical success rate. Complications (n =
6; pericatheter leakage in four of six) were observed more frequently in older
patients (P = .01). The 30-day mortality rate was 17%, one death may have been
procedure related. Forty-three catheters were removed (elective, n = 36; other, n
= 7) after 1-597 days (median, 49). Three catheters remained in situ for 139-482
days (median, 410). CONCLUSIONS: Percutaneous jejunostomy is a feasible and
relatively safe technique for long-term feeding. Leakage is the main problem,
which warrants additional study.
PMID- 10693721
TI - Percutaneous diagnosis and treatment of biliary candidiasis.
PMID- 10693722
TI - Autologous vein stent-graft: feasibility study.
AB - PURPOSE: To evaluate expandable stents healed into vein wall as autologous vein
stent-grafts for endoluminal grafting. MATERIALS AND METHODS: Balloon expandable
stents were placed into external jugular veins of eight dogs. Stent and vein
patency was followed by ultrasonography. Five weeks after stent placement,
jugular veins with endothelialized stent were harvested. The autologous vein
stent-grafts were divided into two groups. In group A, autologous vein stent
grafts (n = 3) were placed immediately into Baker solution for microscopic
examination. In group B, autologous vein stent-grafts (n = 3) underwent
mechanical manipulation; they were compressed, mounted on angioplasty balloon,
pushed through a 9-F sheath and dilated. The autologous vein stent-graft
endothelialization and changes after mechanical manipulation were evaluated by
light and electron microscopy. RESULTS: Stent placement was successful in seven
dogs. One stent migrated into the pulmonary artery. One well placed stent was
damaged by compression dressing and thrombosed. At 5 weeks, gross and microscopic
examinations revealed the autologous vein stent-grafts were fully covered by a
0.115- +/- 0.036-mm-thick neointimal layer. Small wall thrombus was observed in
one autologous vein stent-graft. Repeated manipulations did not result in any
intimal damage or stent loosening in the autologous vein stent-grafts.
CONCLUSION: Expandable stents healed into a vein have potential to be used as
autologous vein stent-grafts for endoluminal grafting without risk of disruption
during percutaneous transcatheter introduction.
PMID- 10693723
TI - Local delivery of nadroparin via hydrogel-coated angioplasty balloon: effect on
platelet deposition and smooth muscle cell proliferation--an experimental study.
AB - PURPOSE: To assess the feasibility of intravascular delivery of nadroparin, a low
molecular-weight heparin, via hydrogel-coated angioplasty balloons, and the
effects of nadroparin delivered in this manner on platelet deposition and smooth
muscle cell (SMC) proliferation. MATERIALS AND METHODS: Tritiated nadroparin was
used to determine the nadroparin-carrying capacity of the hydrogel-coating,
kinetics of release from the balloons, and, in four pigs, delivery of the
nadroparin to the iliac arterial wall. Platelet deposition in nadroparin-treated
iliac arteries versus contralateral iliac arteries dilated with saline-loaded,
hydrogel-coated balloons was quantified in seven pigs using 111Indium-labeled
platelets. Smooth muscle cell proliferation in nadroparin and saline-treated
iliac arteries in 10 pigs was evaluated 7 days after angioplasty with use of
proliferating cell nuclear antigen. RESULTS: Approximately 98 international units
of nadroparin were delivered by the hydrogel-coated balloon, the majority to the
angioplasty site and distal vessel. There was a trend toward decreased platelet
deposition in nadroparin-treated arteries, but statistical significance was not
achieved (P = .1563). Medial SMC proliferation was decreased in the nadroparin
treated arteries in nine of 10 pigs (P = .0137). CONCLUSIONS: Hydrogel-coated
balloons may be used to deliver nadroparin to the arterial wall, with measurable
levels of the drug delivered to the site of angioplasty, and with resultant
decrease in SMC proliferation.
PMID- 10693724
TI - TIPS reduces hepatic asialoglycoprotein receptor concentration in healthy pigs.
AB - PURPOSE: Technetium-99m-labeled diethylenetriamine pentaacetic acid galactosyl
human serum albumin (TcGSA), a new agent for liver scintigraphy, is selectively
attached to asialoglycoprotein receptors on liver cell membranes. A direct
correlation exists between asialoglycoprotein receptor concentration, [R]o and
hepatic functional reserve. The purpose of this study was to determine the
effects of transjugular intrahepatic portosystemic shunting (TIPS) on hepatic
asialoglycoprotein receptor concentration in pigs without liver parenchymal
disease. MATERIALS AND METHODS: TIPS was performed in eight pigs with use of a
single 10-mm-wide x 68-mm-long Wallstent dilated to 10 mm. TcGSA dynamic imaging
studies were performed before and twice after (7 and 14 days) TIPS. To be
included in the study, pigs had to have a patent TIPS at 1 week of follow-up.
Liver function tests were drawn parallel to the TcGSA studies. Liver biopsies
were performed at 2 weeks when the animals were killed. RESULTS: Five of the
eight pigs had open shunts at 1 week and were included in the study. There was a
significant (P < .0001, Student t test) difference between the mean [R]o of the
pre-TIPS studies ([R]o = 1.12+/-0.04 microM) and the mean of the post-TIPS
studies at 7 days ([R]o = 0.40+/-0.04 microM) and 14 days ([R]o = 0.51+/-0.06
microM, P < .01). The only blood test that was abnormal after TIPS was ammonia
(mean, 129.0+/-42.7). Liver biopsies were normal. CONCLUSIONS: TIPS reduces
asialoglycoprotein receptor concentration in normal pigs.
PMID- 10693725
TI - Hemodialysis access declotting: a native fistula is not a prosthetic graft.
PMID- 10693726
TI - Dextromethorphan: another "ecstasy"?
PMID- 10693727
TI - Comorbidity and diagnosing depressive disorders in family practice.
PMID- 10693728
TI - Let the buyer (and reader) beware: targeted advertising in medical journals.
PMID- 10693729
TI - Postfertilization effects of oral contraceptives and their relationship to
informed consent.
AB - The primary mechanism of oral contraceptives is to inhibit ovulation, but this
mechanism is not always operative. When breakthrough ovulation occurs, then
secondary mechanisms operate to prevent clinically recognized pregnancy. These
secondary mechanisms may occur either before or after fertilization.
Postfertilization effects would be problematic for some patients, who may desire
information about this possibility. This article evaluates the available evidence
for the postfertilization effects of oral contraceptives and concludes that good
evidence exists to support the hypothesis that the effectiveness of oral
contraceptives depends to some degree on postfertilization effects. However,
there are insufficient data to quantitate the relative contribution of
postfertilization effects. Despite the lack of quantitative data, the principles
of informed consent suggest that patients who may object to any postfertilization
loss should be made aware of this information so that they can give fully
informed consent for the use of oral contraceptives.
PMID- 10693730
TI - Family responsibilities and domestic activities of US women physicians.
AB - BACKGROUND: Women physicians may have a multiplicity of domestic roles (eg, cook,
housekeeper, child care provider) that are of inherent interest and that may
affect their professional lives, but are largely unstudied. DESIGN, SETTING,
PARTICIPANTS, AND MAIN OUTCOME MEASURES: We report data from respondents (N =
4501) to the Women Physicians' Health Study, a cross-sectional, questionnaire
based study of a stratified random sample of US women MDs. RESULTS: Women
physicians with children aged 0 to 17 years spent a median of 24.4 hours per week
on child care. Women physicians typically spent half an hour per day cooking, and
another half-hour per day on other housework. Little time was spent on gardening:
a median of 0.05 hours (3 minutes) per week. Those performing more domestic tasks
are likely to work fewer hours outside the home and to be on call less often.
Women physicians who are married or widowed, have more children, have lower
personal incomes, and have more highly educated and higher-earning spouses
perform more domestic activities. We found no significant adverse relationship
between time spent on any domestic activity and career satisfaction or mental or
physical health. CONCLUSIONS: Women physicians spend little time on domestic
activities that can be done for them by others, including cooking, housework, and
especially gardening. Women physicians spend somewhat less time on child care and
substantially less time on housework than do other US women. Despite abundant
editorializing about role conflicts of women physicians, our measures of career
satisfaction and mental health were not adversely affected by time spent on
domestic obligations.
PMID- 10693731
TI - Self-reported arthritis-related disruptions in sleep and daily life and the use
of medical, complementary, and self-care strategies for arthritis: the National
Survey of Self-care and Aging.
AB - OBJECTIVE: To assess relations between self-reported arthritis-related
disruptions in sleep, physical activity, and social functioning and use of
medical care, complementary therapies, and self-care for arthritis in older
adults. DESIGN: A survey of self-reported arthritis-related disruptions in sleep
and daily life as risk factors for use of 15 medical, complementary, and self
care modalities for relief of arthritis symptoms. SETTING: General community from
38 urban and 12 rural areas in the contiguous United States. PARTICIPANTS: Nine
hundred thirty-seven older persons reporting arthritis; of the 1925 in the 1993
to 1994 follow-up of the National Survey of Self-care and Aging, a population
based, stratified, random sample of noninstitutionalized Medicare beneficiaries
aged 65 years and older. MAIN OUTCOME MEASURES: Use of 15 medical, self-care, and
complementary modalities for relief of arthritis symptoms. RESULTS: Most
respondents reported use of at least 1 medical, complementary, or self-care
strategy for arthritis. Arthritis was reported to disrupt sleep and leisure in
32.8% and 33.4% of respondents, respectively. Individuals with sleep disruption
were more likely than those without sleep disturbance to use medical,
complementary, and self-care strategies (adjusted odds ratio [95% confidence
interval], 2.31 [1.59-3.37] for seeing a physician; and 2.23 [1.60-3.10] for
using physical modalities). Reported disruption in sleep from arthritis was
associated with use of more medical, complementary, and self-care strategies than
was any other disruption. CONCLUSIONS: Self-reported arthritis-related disruption
in sleep is associated with use of a wide range of medical, complementary, and
self-care strategies. Physicians, other health care providers, and researchers
should not overlook the importance of this common and often-neglected symptom.
PMID- 10693732
TI - The role of competing demands in the treatment provided primary care patients
with major depression.
AB - OBJECTIVE: To examine whether competing demands explain the appearance of
inadequate primary care depression treatment observed at a single visit. DESIGN:
A cross-sectional patient survey. PARTICIPANTS AND SETTING: Two hundred forty
patients with 5 or more symptoms of depression seeing 12 physicians in 6 primary
care practices, representing 77.4% of the depressed patients identified through 2
stage screening of more than 11,000 primary care attenders. MAIN OUTCOME
MEASURES: In patients with elevated depressive symptoms, discussing depression as
a possible diagnosis in untreated patients, and changing depression management in
treated patients. RESULTS: Physicians and patients discussed depression in 46
(47.9%) of 96 untreated patients; physicians changed depression treatment
recommendations in 87 (60.4%) of 144 treated patients with current symptoms.
Chronic physical comorbidity decreased the odds that physicians and untreated
patients discussed depression as a possible diagnosis (odds ratio = 0.66, P =
.01). New problems decreased the odds that treatment recommendations would be
changed in treated patients who remained depressed (odds ratio = 0.39, P = .05).
Physicians and untreated patients were more likely to discuss depression as a
possible diagnosis if patients reported antidepressant medication was acceptable
(odds ratio = 4.57, P = .01) and less likely to discuss depression if patients
reported specialty care counseling was acceptable (odds ratio = 0.33, P = .05).
CONCLUSIONS: The attention depression gets during a given medical visit is less
associated with the severity of the patient's depressive symptoms than with the
number or recency of other problems the patient has. If competing demands provide
ongoing barriers to depression treatment, interventions will be needed to assure
that patients with chronic physical problems receive high-quality mental health
care in the primary care setting.
PMID- 10693733
TI - Sun protection counseling for children: primary care practice patterns and effect
of an intervention on clinicians.
AB - OBJECTIVES: To describe current primary care sun protection advice for children
and assess the effect on clinicians of an intervention to enhance their sun
protection advocacy. SETTING: Primary care practices caring for children in New
Hampshire with special attention to clinicians serving 10 towns that were
involved in a randomized controlled trial of the multicomponent SunSafe
intervention involving schools, recreation areas, and primary care practices.
DESIGN/INTERVENTION: A statewide survey of all primary care clinicians serving
children addressed their self-reported sun protection advocacy practices.
Clinicians in 10 systematically selected rural towns were involved in the
subsequent intervention study. The primary care intervention provided assistance
to practices in establishing an office system that promoted sun protection advice
to children and their parents during office visits. MAIN OUTCOME MEASURES: Sun
protection promotion activities of primary care clinicians as determined by their
self report, research assistant observation, and parent interviews. RESULTS: Of
261 eligible clinicians responding to the statewide survey, about half provide
sun protection counseling "most of the time" or "almost always" during summer
well care visits. Pediatricians do so more often than family physicians.
Clinicians involved in the intervention increased their use of handouts, waiting
room educational materials, and sunscreen samples. Compared with control town
parents, parents in intervention towns reported an increase in clinician sun
protection advice. CONCLUSIONS: The SunSafe primary care intervention increased
sun protection counseling activities of participating clinicians. A single-focus
preventive service office system is feasible to include in community
interventions to promote sun protection.
PMID- 10693734
TI - Orlistat in the long-term treatment of obesity in primary care settings.
AB - OBJECTIVE: To evaluate the long-term efficacy and tolerability within primary
care settings of orlistat, a gastrointestinal lipase inhibitor, for the treatment
of obesity. DESIGN: Randomized, double-blind, placebo-controlled, multicenter
study. PARTICIPANTS: A group of 796 obese patients (body mass index, 30-44
kg/m2), treated with placebo 3 times a day (TID), 60 mg of orlistat TID, or 120
mg of orlistat TID, in conjunction with a reduced-energy diet for the first year
and a weight-maintenance diet during the second year. SETTING: Seventeen primary
care centers in the United States. MAIN OUTCOME MEASURES: Changes in body weight
and obesity-related disease risk factors. RESULTS: Patients treated with orlistat
lost significantly more weight (7.08 +/- 0.54 and 7.94 +/- 0.57 kg for the 60-mg
and 120-mg orlistat groups, respectively) than those treated with placebo (4.14
+/- 0.56 kg) in year 1 (P<.001) and sustained more of this weight loss during
year 2 (P<.001). More patients treated with orlistat lost 5% or more of their
initial weight in year 1 (48.8% and 50.5% of patients in the 60-mg and 120-mg
groups, respectively) compared with placebo (30.7%; P<.001), and approximately
34% of patients in the orlistat groups sustained weight loss of 5% or greater
over 2 years compared with 24% in the placebo group (P<.001). Orlistat produced
greater improvements than placebo in serum lipid levels and blood pressure and
was well tolerated, although treatment resulted in a higher incidence of
gastrointestinal events. CONCLUSIONS: This long-term study indicates that
orlistat is an effective adjunct to dietary intervention in the treatment of
obesity in primary care settings.
PMID- 10693735
TI - Unattended home diagnosis and treatment of obstructive sleep apnea without
polysomnography.
AB - OBJECTIVE: To test the effectiveness of unattended home monitoring along with
automatic titrating continuous positive airway pressure (auto-CPAP) as an
acceptable method for diagnosing and prescribing proper CPAP pressure for
treatment of patients presenting with classic symptoms of obstructive sleep apnea
(OSA). DESIGN: Nonrandomized, prospective case study of 63 patients with a
presumptive diagnosis of OSA. SETTING: University hospital and veterans affairs
medical center ambulatory sleep disorders clinics. PARTICIPANTS: Fifty-eight men
and 5 women were recruited for symptoms of excessive daytime sleepiness, heavy
snoring, and witnessed apnea. INTERVENTION: Subjects with 10 or more respiratory
events per hour were titrated by automatic, unattended home monitoring to an
optimal CPAP pressure. MAIN OUTCOME MEASURES: Number of subjects able to be
diagnosed by unattended home monitoring, titrated to optimal CPAP pressure,
accepted an auto-CPAP machine for home use, and symptoms improved. RESULTS: Fifty
four (86%) of 63 patients completed sufficient diagnostic studies, and in 45
(83%) of these, a diagnosis of OSA was established. Nine subjects were unable to
adjust to the nasal mask for an adequate diagnostic recording, and 9 had fewer
than 10 respiratory events per hour. Ten subjects with OSA could not complete a
titration study. Thirty-five of the subjects diagnosed with OSA accepted the auto
CPAP machine into their home, while 30 used it for therapy longer than 3 weeks.
The estimated cost of performing in-home studies was less than one fourth of the
estimated cost for in-laboratory polysomnographic examinations had they been
performed. CONCLUSION: Unattended monitoring plus auto-CPAP allows cost-effective
diagnosis and CPAP titration of most patients with OSA with straightforward
symptoms.
PMID- 10693736
TI - New treatments and therapeutic strategies for acne.
AB - Successful management of acne requires careful patient evaluation followed by
consideration of several patient and medication factors when selecting a
particular therapeutic regimen. Within the last few years, several new agents for
the treatment of acne have become available that afford greater flexibility in
the treatment of this prevalent dermatologic disorder. These include adapalene,
tazarotene, 2 new topical tretinoin formulations, azelaic acid, a new sodium
sulfacetamide formulation, and an oral contraceptive recently approved by the
Food and Drug Administration for the treatment of acne. After a brief overview of
the pathophysiology of acne and existing therapies, this review evaluates the new
antiacne agents and how they can be integrated into a successful treatment
strategy that takes into account acne severity and predominant lesion type as
well as age, skin type, lifestyle, motivation, and the presence of coexisting
conditions.
PMID- 10693737
TI - Hypertriglyceridemia and coronary heart disease.
PMID- 10693738
TI - Improving social adjustment in children with attention-deficit/hyperactivity
disorder.
AB - OBJECTIVE: To determine if sending motivational letters would improve peer
relations in children with social maladjustment and attention
deficit/hyperactivity disorder (ADHD). DESIGN: From a consecutive sample, a case
series was followed up for 2 years. SETTING: Primary care, private physician,
office-based practice. PATIENTS: Ninety-five children diagnosed as having ADHD by
Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria
made up the consecutive sample. Twenty-one children qualified with a comorbid
social maladjustment disorder with baseline t scores of 1.5 SDs or greater above
the mean on the asocial domain of the Conners' Teacher Rating Scale. Seventeen
children completed the study. There were no significant differences between these
patients and those who did not complete the study (P = .55 for baseline score
differences and P = .85 for age). INTERVENTIONS: In addition to conventional
therapy for ADHD when children achieved a goal, such as an improved report card
or better conduct, a personal letter about their success was mailed to them.
Letters averaged 5 per student per year. MAIN OUTCOME MEASURES: The asocial
domain of the Conners' Teacher Rating Scale was repeated during the next 2 school
years for comparison. Statistical analysis was by a repeated-measures analysis of
variance and Helmert contrasts. RESULTS: Of 17 students who completed the study,
16 improved on the Conners' Teacher Rating Scale asocial domain, and the results
were statistically significant (P<.001). CONCLUSIONS: Difficulties with peer
relations are commonly seen in children with ADHD. Sending motivational letters
correlated with improved social adjustment in these children. The data suggest
that busy practitioners might consider incorporating this successful, and time
efficient, intervention into their ADHD treatment regimens.
PMID- 10693739
TI - Spontaneous splenic infarction secondary to diabetes-induced microvascular
disease.
AB - Splenic infarction is a clinical entity seldom encountered. The most frequent
causes of splenic infarction include thromboembolic phenomena, hematologic
malignant neoplasms, and vasculitides. We describe a patient who sustained
splenic infarction secondary to diabetes-induced, small-vessel atherosclerotic
disease.
PMID- 10693740
TI - A product of the culture.
PMID- 10693742
TI - Characterization of Trypanozoon isolates using a repeated coding sequence and
microsatellite markers.
AB - Genetic variation of microsatellite loci is a widely used method for linkage
analysis, individual identification or inter-population studies. Here we analyse
a repeated DNA coding sequence and eleven new microsatellites identified within
the Trypanosoma (Trypanozoon) brucei genome. Ninety-seven isolates belonging to
the five species and subspecies Trypanosoma evansi, T. equiperdum, T. brucei
brucei, T. b. rhodesiense and T. b. gambiense were compared regarding the genetic
patterns of these markers. The results reveal a great heterogeneity of the
genotypes related to the repeated coding sequence and five microsatellites, some
of which show a high degree of polymorphism. This allows us to define group
specific genotypes or alleles; in particular, we show that one specific pattern
clearly segregates the human pathogen T. b. gambiense group I.
PMID- 10693741
TI - Molecular characterization of P-29, a metacestode-specific component of
Echinococcus granulosus which is immunologically related to, but distinct from,
antigen 5.
AB - In this work the characterization of P-29, a novel 29 kDa antigen from
Echinococcus granulosus is reported. E. granulosus was identified while looking
for parasite antigens distinct from those present in hydatid cyst fluid. A
monoclonal antibody (mAb 47H.PS) prepared against protoscolex components revealed
that P-29 is localized to the tegument and rostellum of protoscoleces, and to the
germinal layer of the cyst, but it is absent in hydatid cyst fluid or adult worm
extracts. Several internal fragments of P-29 showed sequence identity to the
amino acid sequence encoded by Eg6, a partial gene sequence reported to code for
an epitope of antigen 5 (Ag5), one of the major diagnostic antigens of the
parasite. We confirmed that Eg6 encodes a sub-fragment of P-29 by mapping the
epitope of mAb 47H.PS, and isolating the full length P-29 cDNA. Since Eg6 had
been, postulated to encode a fragment of Ag5, we specifically studied the
relationship of P-29 and Ag5 by: (i) examining the cross-reactivity displayed by
different mAbs; (ii) comparison of their peptide finger prints; and (iii) a
comparative study of their diagnostic value. Our results prove unequivocally that
P-29 and Ag5 are immunologically related, but different proteins, raising several
questions on the current knowledge of Ag5.
PMID- 10693743
TI - Tetrameric and dimeric malate dehydrogenase isoenzymes in Trypanosoma cruzi
epimastigotes.
AB - Two malate dehydrogenase isoforms, named MDH1 and MDH2, have been purified to
homogeneity from Trypanosoma cruzi epimastigotes. Both enzymes consist of
subunits with a molecular mass close to 33 kDa; native molecular mass
determination by gel filtration, however, indicated that MDH1 is a dimer, whereas
MDH2 is a tetramer. Both isoforms did not cross-react immunologically. The N
termini of both MDH isoforms and several tryptic peptides of MDH1 (amounting to
about one third of the complete molecule) have been sequenced by automated Edman
degradation. The tryptic digests of both enzymes have also been analysed by mass
spectrometry (MALDI-TOF MS). The apparent Km values in both directions of the
reaction have been determined, as well as the possible inhibition by excess of
the substrate oxaloacetate. The sequence data, together with the pI values and
the presence or absence of oxaloacetate inhibition indicate that the dimeric MDH1
is the mitochondrial isoenzyme, whereas the tetrameric MDH2 is the glycosomal
isoenzyme. No evidence was found for the presence of a cytosolic isoform.
PMID- 10693744
TI - Purification and characterization of Plasmodium falciparum succinate
dehydrogenase.
AB - Succinate dehydrogenase (SDH), a Krebs cycle enzyme and complex II of the
mitochondrial electron transport system was purified to near homogeneity from the
human malarial parasite Plasmodium falciparum cultivated in vitro by FPLC on Mono
Q, Mono S and Superose 6 gel filtration columns. The malarial SDH activity was
found to be extremely labile. Based on Superose 6 FPLC, sodium dodecyl sulfate
polyacrylamide gel electrophoresis (SDS-PAGE) and nondenaturing-PAGE analyses, it
was demonstrated that the malarial enzyme had an apparent native molecular mass
of 90 +/- 8 kDa and contained two major subunits with molecular masses of 55 +/-
6 and 35 +/- 4 kDa (n = 8). The enzymatic reaction required both succinate and
coenzyme Q (CoQ) for its maximal catalysis with Km values of 3 and 0.2 microM,
and k(cat) values of 0.11 and 0.06 min(-1), respectively. Catalytic efficiency of
the malarial SDH for both substrates were found to be relatively low
(approximately 600-5000 M(-1) s(-1)). Fumarate, malonate and oxaloacetate were
found to inhibit the malarial enzyme with Ki values of 81, 13 and 12 microM,
respectively. The malarial enzyme activity was also inhibited by substrate analog
of CoQ, 5-hydroxy-2-methyl-1,4-naphthoquinone, with a 50% inhibitory
concentration of 5 microM. The quinone had antimalarial activity against the in
vitro growth of P. falciparum with a 50% inhibitory concentration of 0.27 microM
and was found to completely inhibit oxygen uptake of the parasite at a
concentration of 0.88 microM. A known inhibitor of mammalian mitochondrial SDH, 2
thenoyltrifluoroacetone. had no inhibitory effect on both the malarial SDH
activity and the oxygen uptake of the parasite at a concentration of 50 microM.
Many properties observed in the malarial SDH were found to be different from the
host mammalian enzyme.
PMID- 10693745
TI - Secretion of a novel class of iFABPs in nematodes: coordinate use of the
Ascaris/Caenorhabditis model systems.
AB - A novel fatty acid binding protein, As-p18, is secreted into both the
perivitelline and perienteric fluids of the parasitic nematode, Ascaris suum, and
at least eight potential homologues of As-p18 have been identified in the
Caenorhabditis elegans genome. The products of the three most closely related
homologues are fatty acid binding proteins (LBP-1, LBP-2 and LBP-3) which contain
putative secretory signals. Phylogenetic analysis revealed that these secreted
fatty acid binding proteins comprise a distinct gene class within the fatty acid
binding protein family and are possibly unique to nematodes. To examine the
potential sites of As-p18 secretion, the expression of the putative promoters of
the C. elegans homologues was examined with GFP reporter constructs. The
developmental expression of lbp-1 was identical to that of As-p18 and consistent
with the secretion of LBP-1 from the hypodermis to the perivitelline fluid. The
expression patterns of lbp-2 and lbp-3 were consistent with the secretion of LBP
2 and LBP-3 from muscle into the perienteric fluid later in development. These
studies demonstrate that at least some perivitelline fluid proteins appear to be
secreted from the hypodermis prior to the formation of the cuticle and, perhaps
more importantly, that this coordinate C. elegans/A. suum approach may be
potentially useful for examining a number of key physiological processes in
parasitic nematodes.
PMID- 10693746
TI - Intracellular pH in mammalian stages of Trypanosoma cruzi is K+-dependent and
regulated by H+-ATPases.
AB - Regulation of intracellular pH (pHi) was investigated in Trypanosoma cruzi
amastigotes and trypomastigotes using 2',7'-bis-(carboxyethyl)-5(and-6)
carboxyfluorescein (BCECF). pHi was determined to be 7.33 +/- 0.08 and 7.35 +/-
0.07 in amastigotes and trypomastigotes, respectively, and there were no
significant differences in the regulation of pH, between the two stages. Steady
state pHi, recovery of pHi from acidification, and H+-efflux were all decreased
markedly by the H+-ATPase inhibitors N,N'-dicyclohexylcarbodi-imide (DCCD),
diethylstilbestrol (DES) and N-ethylmaleimide (NEM) supporting a significant role
for a plasma membrane H+-ATPase in the regulation of pHi. pHi was maintained at
neutrality over a range of external pH (pHe) from 5-8 in parasites suspended in a
buffer containing Na+ and K+ (standard buffer) but was acidified at low pHe in
the absence of these cations (choline buffer). The pHi of trypomastigotes
decreased significantly when they transformed into amastigotes. The rate of
recovery of pHi by acidified parasites was similar in Na+-free buffer and
standard buffer but was slower in the absence of K+ (K+-free or choline buffer)
and parasites suspended in choline buffer were acidic by 0.25 pH units as
compared with controls. Ba2+ and Cs+ decreased the pHi of parasites suspended in
standard but not choline buffer suggesting the presence of an inward directed K+
channel. The pHi of amastigotes and trypomastigotes suspended in Cl(-)-free
buffer was decreased by 0.13 and 0.2 pH units, respectively, supporting the
presence of a chloride conductive channel. No evidence of pH regulation via a
Na+/H+ or Cl-/HCO3- exchanger was found. These results are consistent with the
presence of a plasma membrane H+-ATPase that regulates pHi and is supported by K+
and Cl- channels.
PMID- 10693747
TI - Molecular analysis of a Type I fatty acid synthase in Cryptosporidium parvum.
AB - We report here the molecular analysis of a Type I fatty acid synthase in the
apicomplexan Cryptosporidium parvum (CpFAS1). The CpFAS1 gene encodes a
multifunctional polypeptide of 8243 amino acids that contains 21 enzymatic
domains. This CpFAS1 structure is distinct from that of mammalian Type I FAS,
which contains only seven enzymatic domains. The CpFAS1 domains are organized
into: (i) a starter unit consisting of a fatty acid ligase and an acyl carrier
protein; (ii) three modules, each containing a complete set of six enzymes (acyl
transferase, ketoacyl synthase, ketoacyl reductase, dehydrase, enoyl reductase,
and acyl carrier protein) for the elongation of fatty acid C2-units; and (iii) a
terminating domain whose function is as yet unknown. The CpFAS1 gene is expressed
throughout the life cycle of C. parvum, since its transcripts and protein were
detected by RT-PCR and immunofluorescent localization, respectively. This
cytosolic Type I CpFAS1 differs from the organellar Type II FAS enzymes
identified from Toxoplasma gondii and Plasmodium falciparum which are targetted
to the apicoplast, and are sensitive to inhibition by thiolactomycin. That the
discovery of CpFAS1 may provide a new biosynthetic pathway for drug development
against cryptosporidiosis, is indicated by the efficacy of the FAS inhibitor
cerulenin on the growth of C. parvum in vitro.
PMID- 10693748
TI - Calcium mobilization by arachidonic acid in trypanosomatids.
AB - A recent report (Eintracht J, Maathai R, Mellors A, Ruben L. Calcium entry in
Trypanosoma brucei is regulated by phospholipase A, and arachidonic acid, Biochem
J 1998:336:659-66) provided evidence that calcium entry in Trypanosoma brucei
bloodstream trypomastigotes is regulated via a signaling pathway involving
phospholipase A2-mediated generation of arachidonic acid and stimulation of a
plasma membrane-located calcium channel. Here we show that Ca2+ influx in T.
brucei procyclic trypomastigotes, Leishmania donovani promastigotes and T. cruzi
amastigotes was also stimulated in a dose-dependent manner (50-400 nM) by the
amphiphilic peptide melittin. This effect was blocked by the phospholipase A,
inhibitor 3-(4-octadecyl)-benzoylacrylic acid. The unsaturated fatty acid
arachidonic acid, in the range of 10-75 microM, induced Ca2+ entry by a mechanism
sensitive to LaCl3. However, both melittin and arachidonic acid induced an
increase in [Ca2+]i in T. brucei procyclic trypomastigotes incubated in Ca2+-free
medium implying Ca2+ mobilization from intracellular stores. This hypothesis was
supported by experiments showing that arachidonic acid promoted Ca2+ release from
the acidocalcisomes of these cells. The results showing changes in mitochondrial
membrane potential, release of acridine orange and Ca2+ from the acidocalcisomes
and Ca2+ transport across the plasma membrane suggest that in addition to the
possible stimulation of a Ca2+ channel-mediated process, arachidonic acid, in the
range of concentrations used here, have other nonspecific effects on the
trypanosomatids membranes.
PMID- 10693749
TI - The secretory Onchocerca volvulus protein OvS1/Ov20 exhibits the capacity to
compete with serum albumin for the host's long-chain fatty acids.
AB - The mechanism by which filarial parasites derive fatty acids bound to the host's
carrier protein is poorly understood. The capacity of a secretory protein of
Onchocerca volvulus (OvS1/Ov20) to compete with serum albumin for arachidonic and
other fatty acids was investigated in this study. Binding affinities of the two
proteins for the long-chain fatty acids were determined using displacement
assays. The fluorescent probes used included 11-((5-dimethylaminonaphthalene-1
sulfonyl)amino) undecanoic acid (DAUDA) and cis-parinaric acid. OvS1 protein
bound arachidonic acid with an affinity five-fold greater than the affinity
exhibited by serum albumin. Oleic acid was bound by the parasite protein with an
affinity two-fold greater than the affinity shown by serum albumin. Furthermore,
the affinities exhibited by OvS1 protein in binding arachidonic and linoleic acid
were about two times higher than the affinity for oleic acid. The results suggest
that the OvS1 protein has the capacity to compete with the main host's fatty acid
carrier protein for the long-chain fatty acids, in particular arachidonic acid,
the precursor for eicosanoids.
PMID- 10693750
TI - Characterisation of the loci encoding the glutamic acid and alanine rich protein
of Trypanosoma congolense.
AB - We have characterised the organisation of genes encoding the glutamate and
alanine rich protein (GARP) surface coat of the procyclic and epimastigote stages
of Trypanosoma congolense in the tsetse fly. The GARP genes are arranged at two,
possibly physically linked, loci, one of which exhibits allelic variation. One
locus contains a single GARP gene, whilst both alleles of the other have a large
tandem array of polycistronically transcribed GARP genes. Sequence analysis has
revealed that there are very few coding differences between different GARP genes.
A sequence related to the Trypanosoma brucei expression site associated gene 4
(encoding a transmembrane protein with a cytoplasmic adenylate cyclase domain)
has been identified within a region at the downstream flank of one locus. There
is no evidence that, within the single trypanosome, GARP genes are as diverse as
the procyclin genes that encode a corresponding coat in T. brucei.
PMID- 10693751
TI - Fluorescence microscopy and fluorescence in situ hybridization of Entamoeba
histolytica nuclei to analyse mitosis and the localization of repetitive DNA.
PMID- 10693752
TI - A novel member of the NK-lysin protein family is developmentally regulated and
secreted by Fasciola hepatica.
PMID- 10693753
TI - Two major 'higher molecular mass proteinases' of Entamoeba histolytica are
identified as cysteine proteinases 1 and 2.
PMID- 10693754
TI - A simple RNA analysis method shows var and rif multigene family expression
patterns in Plasmodium falciparum.
PMID- 10693755
TI - The multiple roles of PTEN in tumor suppression.
PMID- 10693756
TI - Regulated intramembrane proteolysis: a control mechanism conserved from bacteria
to humans.
PMID- 10693757
TI - Analysis of partner of inscuteable, a novel player of Drosophila asymmetric
divisions, reveals two distinct steps in inscuteable apical localization.
AB - Asymmetric localization is a prerequisite for inscuteable (insc) to function in
coordinating and mediating asymmetric cell divisions in Drosophila. We show here
that Partner of Inscuteable (Pins), a new component of asymmetric divisions, is
required for Inscuteable to asymmetrically localize. In the absence of pins,
Inscuteable becomes cytoplasmic and asymmetric divisions of neuroblasts and
mitotic domain 9 cells show defects reminiscent of insc mutants. Pins colocalizes
with Insc and interacts with the region necessary and sufficient for directing
its asymmetric localization. Analyses of pins function in neuroblasts reveal two
distinct steps for Insc apical cortical localization: A pins-independent, bazooka
dependent initiation step during delamination (interphase) and a later
maintenance step during which Baz, Pins, and Insc localization are
interdependent.
PMID- 10693758
TI - Opposing transcriptional outputs of Hedgehog signaling and engrailed control
compartmental cell sorting at the Drosophila A/P boundary.
AB - The wing imaginal disc is subdivided into two nonintermingling sets of cells, the
anterior (A) and posterior (P) compartments. Anterior cells require reception of
the Hedgehog (Hh) signal to segregate from P cells. We provide evidence that Hh
signaling controls A/P cell segregation not by directly modifying structural
components but by a Cubitus interruptus (Ci)-mediated transcriptional response. A
shift in the balance between repressor and activator forms of Ci toward the
activator form is necessary and sufficient to define "A-type" cell sorting
behavior. Moreover, we show that Engrailed (En), in the absence of Ci, is
sufficient to specify "P-type" sorting. We propose that the opposing
transcriptional activities of Ci and En control cell segregation at the A/P
boundary by regulating a single cell adhesion molecule.
PMID- 10693759
TI - Hedgehog-regulated processing of Gli3 produces an anterior/posterior repressor
gradient in the developing vertebrate limb.
AB - Ci/Gli zinc finger proteins mediate the transcriptional effects of Hedgehog
protein signals. In Drosophila, Ci action as transcriptional repressor or
activator is contingent upon Hedgehog-regulated, PKA-dependent proteolytic
processing. We demonstrate that PKA-dependent processing of vertebrate Gli3 in
developing limb similarly generates a potent repressor in a manner antagonized by
apparent long-range signaling from posteriorly localized Sonic hedgehog protein.
The resulting anterior/posterior Gli3 repressor gradient can be perturbed by
mutations of Gli3 in human genetic syndromes or by misregulation of Gli3
processing in the chicken mutant talpid2, producing a range of limb patterning
malformations. The high relative abundance and potency of Gli3 repressor suggest
specialization of Gli3 and its products for negative Hedgehog pathway regulation.
PMID- 10693760
TI - Ras1 promotes cellular growth in the Drosophila wing.
AB - The Ras GTPase links extracellular mitogens to intracellular mechanisms that
control cell proliferation. To understand how Ras regulates proliferation in
vivo, we activated or inactivated Ras in cell clones in the developing Drosophila
wing. Cells lacking Ras were smaller, had reduced growth rates, accumulated in
G1, and underwent apoptosis due to cell competition. Conversely, activation of
Ras increased cell size and growth rates and promoted G1/S transitions. Ras
upregulated the growth driver dMyc, and both Ras and dMyc increased levels of
cyclin E posttranscriptionally. We propose that Ras primarily promotes growth and
that growth is coupled to G1/S progression via cyclin E. Interestingly,
upregulation of growth by Ras did not deregulate G2/M progression or a
developmentally regulated cell cycle exit.
PMID- 10693761
TI - Crystal structure of the VHS and FYVE tandem domains of Hrs, a protein involved
in membrane trafficking and signal transduction.
AB - We have determined the 2 A X-ray structure of the 219-residue N-terminal VHS and
FYVE tandem domain unit of Drosophila Hrs. The unit assumes a pyramidal structure
in which the much larger VHS domain (residues 1-153) forms a rectangular base and
the FYVE domain occupies the apical end. The VHS domain is comprised of an
unusual "superhelix" of eight alpha helices, and the FYVE domain is mainly built
of loops, two double-stranded antiparallel sheets, and a helix stabilized by two
tetrahedrally coordinated zinc atoms. The two-domain structure forms an exact 2
fold-related homodimer through antiparallel association of mainly FYVE domains.
Dimerization creates two identical pockets designed for binding ligands with
multiple negative charges such as citrate or phosphatidylinositol 3-phosphate.
PMID- 10693762
TI - A role for CaMKII in T cell memory.
AB - In order to study the role of calcium/calmodulin kinase II (CaMKII) in T cells,
we generated transgenic mice expressing CaMKIIgammaB* (T287D), a partially
calcium-independent mutant of CaMKIIgammaB. In these mice, the size of the thymus
was increased 1.5- to 2-fold, at least in part due to an increase in the lifespan
of double-positive (DP) thymocytes. More importantly, there was an increase in
the number of T cells in the secondary lymphoid organs that had acquired an
antigen-dependent memory phenotype. These T cells were bonafide memory cells as
assessed by a variety of criteria. In addition, T cells from wild-type mice
acquired calcium-independent CaMKII activity after several rounds of antigen
stimulated division. We propose that CaMKII controls a distinct process of
activation-induced cellular differentiation.
PMID- 10693763
TI - Regulation of auxin response by the protein kinase PINOID.
AB - Arabidopsis plants carrying mutations in the PINOID (PID) gene have a pleiotropic
shoot phenotype that mimics that of plants grown on auxin transport inhibitors or
of plants mutant for the auxin efflux carrier PINFORMED (PIN), with defects in
the formation of cotyledons, flowers, and floral organs. We have cloned PID and
find that it is transiently expressed in the embryo and in initiating floral
anlagen, demonstrating a specific role for PID in promoting primordium
development. Constitutive expression of PID causes a phenotype in both shoots and
roots that is similar to that of auxin-insensitive plants, implying that PID,
which encodes a serine-threonine protein kinase, negatively regulates auxin
signaling.
PMID- 10693764
TI - The Saccharomyces Pif1p DNA helicase and the highly related Rrm3p have opposite
effects on replication fork progression in ribosomal DNA.
AB - Replication of Saccharomyces ribosomal DNA (rDNA) proceeds bidirectionally from
origins in a subset of the approximately 150 tandem repeats, but the leftward
moving fork stops when it encounters the replication fork barrier (RFB). The
Pif1p helicase and the highly related Rrm3p were rDNA associated in vivo. Both
proteins affected rDNA replication but had opposing effects on fork progression.
Pif1p helped maintain the RFB. Rrm3p appears to be the replicative helicase for
rDNA as it acted catalytically to promote fork progression throughout the rDNA.
Loss of Rrm3p increased rDNA breakage and accumulation of rDNA circles, whereas
breakage and circles were less common in pif1 cells. These data support a model
in which replication fork pausing causes breakage and recombination in the rDNA.
PMID- 10693765
TI - Science and more for TB.
PMID- 10693766
TI - Fossil smuggling unopposed.
PMID- 10693767
TI - Feathers fly over Chinese fossil bird's legality and authenticity.
PMID- 10693768
TI - The biggest, wildest fossil market in the west.
PMID- 10693769
TI - Protein structure groups seek to draft common ground rules.
PMID- 10693770
TI - South African government rejects AZT advice.
PMID- 10693771
TI - Consortium aims to kick-start TB research.
PMID- 10693772
TI - Europe's X-ray observatory defies the jinx...
PMID- 10693773
TI - Oxford professor faces business link inquiry.
PMID- 10693774
TI - Reliance on the citation index undermines the study of biodiversity.
PMID- 10693775
TI - Proteomics could be key in battle against malaria.
PMID- 10693776
TI - X chromosomes forget where they came from.
PMID- 10693777
TI - Don't let politics put Diamond at risk
PMID- 10693778
TI - One-stop shop for microarray data.
PMID- 10693779
TI - Where do babies come from?
PMID- 10693780
TI - Total internal reflection.
PMID- 10693781
TI - Taiwan's gift to the world.
PMID- 10693782
TI - Display technology. Sidestepping the selection rules
PMID- 10693784
TI - Climate change. The hole record
PMID- 10693783
TI - Mining the genome for iron.
PMID- 10693785
TI - A provirus put to work.
PMID- 10693786
TI - Superconductivity. From obscurity to impurity
PMID- 10693787
TI - Ecology. The complexity of co-dependency.
PMID- 10693788
TI - Mathematics. A gathering of groups
PMID- 10693790
TI - Dennis Sciama (1926-99)
PMID- 10693789
TI - Developmental biology. Raising the roof.
PMID- 10693791
TI - Conversion of diploidy to haploidy.
PMID- 10693792
TI - Reactivation of Borrelia infection in birds.
PMID- 10693793
TI - Do mussels take wooden steps to deep-sea vents?
PMID- 10693794
TI - Supernova explosions in the Universe.
AB - During the lifetime of our Milky Way galaxy, there have been something like 100
million supernova explosions, which have enriched the Galaxy with the oxygen we
breathe, the iron in our cars, the calcium in our bones and the silicon in the
rocks beneath our feet. These exploding stars also influence the birth of new
stars and are the source of the energetic cosmic rays that irradiate us on the
Earth. The prodigious amount of energy (approximately 10(51), or approximately
2.5 x 10(28) megatonnes of TNT equivalent) and momentum associated with each
supernova may even have helped to shape galaxies as they formed in the early
Universe. Supernovae are now being used to measure the geometry of the Universe,
and have recently been implicated in the decades-old mystery of the origin of the
gamma-ray bursts. Together with major conceptual advances in our theoretical
understanding of supernovae, these developments have made supernovae the centre
of attention in astrophysics.
PMID- 10693795
TI - Genetic ablation reveals that the roof plate is essential for dorsal interneuron
specification.
AB - During neural development in vertebrates, a spatially ordered array of neurons is
generated in response to inductive signals derived from localized organizing
centres. One organizing centre that has been proposed to have a role in the
control of neural patterning is the roof plate. To define the contribution of
signals derived from the roof plate to the specification of neuronal cell types
in the dorsal neural tube, we devised a genetic strategy to ablate the roof plate
selectively in mouse embryos. Embryos without a roof plate lack all the
interneuron subtypes that are normally generated in the dorsal third of the
neural tube. Using a genetically based lineage analysis and in vitro assays, we
show that the loss of these neurons results from the elimination of non
autonomous signals provided by the roof plate. These results reveal that the roof
plate is essential for specifying multiple classes of neurons in the mammalian
central nervous system.
PMID- 10693796
TI - Origin of the Moon's orbital inclination from resonant disk interactions
AB - The Moon is generally believed to have formed from the debris disk created by a
large body colliding with the early Earth. Recent models of this process predict
that the orbit of the newly formed Moon should be in, or very near, the Earth's
equatorial plane. This prediction, however, is at odds with the known history of
the lunar orbit: the orbit is currently expanding, but can be traced back in time
to reveal that, when the Moon formed, its orbital inclination relative to the
Earth's equator was I approximately = 10 degrees. The cause of this initial
inclination has been a mystery for over 30 years, as most dynamical processes
(such as those that act to flatten Saturn's rings) will tend to decrease orbital
inclinations. Here we show that the Moon's substantial orbital inclination is
probably a natural result of its formation from an impact-generated disk. The
mechanism involves a gravitational resonance between the Moon and accretion-disk
material, which can increase orbital inclinations up to approximately 15 degrees.
PMID- 10693797
TI - Preparing pure photon number states of the radiation field
AB - The quantum mechanical description of a radiation field is based on states that
are characterized by the number of photons in a particular mode; the most basic
quantum states are those with fixed photon number, usually referred to as number
(or Fock) states. Although Fock states of vibrational motion can be observed
readily in ion traps, number states of the radiation field are very fragile and
difficult to produce and maintain. Single photons in multi-mode fields have been
generated using the technique of photon pairs. But in order to generate these
states in a cavity, the mode in question must have minimal losses; moreover,
additional sources of photon number fluctuations, such as the thermal field, must
be eliminated. Here we observe the build-up of number states in a high-Q cavity,
by investigating the interaction dynamics of a probe atom with the field. We
employ a dynamical method of number state preparation that involves state
reduction of highly excited atoms in a cavity, with a photon lifetime as high as
0.2 seconds. (This set-up is usually known as the one-atom maser or
'micromaser'.) Pure states containing up to two photons are measured
unambiguously.
PMID- 10693798
TI - Imaging the effects of individual zinc impurity atoms on superconductivity in
Bi2Sr2CaCu2O8+delta
AB - Although the crystal structures of the copper oxide high-temperature
superconductors are complex and diverse, they all contain some crystal planes
consisting of only copper and oxygen atoms in a square lattice: superconductivity
is believed to originate from strongly interacting electrons in these CuO2
planes. Substituting a single impurity atom for a copper atom strongly perturbs
the surrounding electronic environment and can therefore be used to probe high
temperature superconductivity at the atomic scale. This has provided the
motivation for several experimental and theoretical studies. Scanning tunnelling
microscopy (STM) is an ideal technique for the study of such effects at the
atomic scale, as it has been used very successfully to probe individual impurity
atoms in several other systems. Here we use STM to investigate the effects of
individual zinc impurity atoms in the high-temperature superconductor
Bi2Sr2CaCu2O8+delta. We find intense quasiparticle scattering resonances at the
Zn sites, coincident with strong suppression of superconductivity within
approximately 15 A of the scattering sites. Imaging of the spatial dependence of
the quasiparticle density of states in the vicinity of the impurity atoms reveals
the long-sought four-fold symmetric quasiparticle 'cloud' aligned with the nodes
of the d-wave superconducting gap which is believed to characterize
superconductivity in these materials.
PMID- 10693799
TI - High-efficiency fluorescent organic light-emitting devices using a phosphorescent
sensitizer
AB - To obtain the maximum luminous efficiency from an organic material, it is
necessary to harness both the spin-symmetric and anti-symmetric molecular
excitations (bound electron-hole pairs, or excitons) that result from electrical
pumping. This is possible if the material is phosphorescent, and high
efficiencies have been observed in phosphorescent organic light-emitting devices.
However, phosphorescence in organic molecules is rare at room temperature. The
alternative radiative process of fluorescence is more common, but it is
approximately 75% less efficient, due to the requirement of spin-symmetry
conservation. Here, we demonstrate that this deficiency can be overcome by using
a phosphorescent sensitizer to excite a fluorescent dye. The mechanism for
energetic coupling between phosphorescent and fluorescent molecular species is a
long-range, non-radiative energy transfer: the internal efficiency of
fluorescence can be as high as 100%. As an example, we use this approach to
nearly quadruple the efficiency of a fluorescent red organic light-emitting
device.
PMID- 10693800
TI - Explanation for fracture spacing in layered materials
AB - The spacing of opening-mode fractures in layered materials--such as certain
sedimentary rocks and laminated engineering materials--is often proportional to
the thickness of the fractured layer. Experimental studies of this phenomenon
show that the spacing initially decreases as extensional strain increases in the
direction perpendicular to the fractures. But at a certain ratio of spacing to
layer thickness, no new fractures form and the additional strain is accommodated
by further opening of existing fractures: the spacing then simply scales with
layer thickness, which is called fracture saturation. This is in marked contrast
to existing theories of fracture, such as the stress-transfer theory, which
predict that spacing should decrease with increasing strain ad infinitum.
Recently, two of us (T.B. and D.D.P.) have used a combination of numerical
simulations and laboratory experiments to show that, with increasing applied
stress, the normal stress acting between such fractures undergoes a transition
from tensile to compressive, suggesting a cause for fracture saturation. Here we
investigate the full stress distribution between such fractures, from which we
derive an intuitive physical model of the process of fracture saturation. Such a
model should find wide applicability, from geosciences to engineering.
PMID- 10693801
TI - Temperature trends over the past five centuries reconstructed from borehole
temperatures
AB - For an accurate assessment of the relative roles of natural variability and
anthropogenic influence in the Earth's climate, reconstructions of past
temperatures from the pre-industrial as well as the industrial period are
essential. But instrumental records are typically available for no more than the
past 150 years. Therefore reconstructions of pre-industrial climate rely
principally on traditional climate proxy records, each with particular strengths
and limitations in representing climatic variability. Subsurface temperatures
comprise an independent archive of past surface temperature changes that is
complementary to both the instrumental record and the climate proxies. Here we
use present-day temperatures in 616 boreholes from all continents except
Antarctica to reconstruct century-long trends in temperatures over the past 500
years at global, hemispheric and continental scales. The results confirm the
unusual warming of the twentieth century revealed by the instrumental record, but
suggest that the cumulative change over the past five centuries amounts to about
1 K, exceeding recent estimates from conventional climate proxies. The strength
of temperature reconstructions from boreholes lies in the detection of long-term
trends, complementary to conventional climate proxies, but to obtain a complete
picture of past warming, the differences between the approaches need to be
investigated in detail.
PMID- 10693802
TI - Effect of stream channel size on the delivery of nitrogen to the Gulf of Mexico
AB - An increase in the flux of nitrogen from the Mississippi river during the latter
half of the twentieth century has caused eutrophication and chronic seasonal
hypoxia in the shallow waters of the Louisiana shelf in the northern Gulf of
Mexico. This has led to reductions in species diversity, mortality of benthic
communities and stress in fishery resources. There is evidence for a
predominantly anthropogenic origin of the increased nitrogen flux, but the
location of the most significant sources in the Mississippi basin responsible for
the delivery of nitrogen to the Gulf of Mexico have not been clearly identified,
because the parameters influencing nitrogen-loss rates in rivers are not well
known. Here we present an analysis of data from 374 US monitor ing stations,
including 123 along the six largest tributaries to the Mississippi, that shows a
rapid decline in the average first-order rate of nitrogen loss with channel size-
from 0.45 day (-1) in small streams to 0.005 day (-1) in the Mississippi river.
Using stream depth as an explanatory variable, our estimates of nitrogen-loss
rates agreed with values from earlier studies. We conclude that the proximity of
sources to large streams and rivers is an important determinant of nitrogen
delivery to the estuary in the Mississippi basin, and possibly also in other
large river basins.
PMID- 10693803
TI - Producer-decomposer co-dependency influences biodiversity effects.
AB - Producers, such as plants and algae, acquire nutrients from inorganic sources
that are supplied primarily by decomposers whereas decomposers, mostly fungi and
bacteria, acquire carbon from organic sources that are supplied primarily by
producers. This producer-decomposer co-dependency is important in governing
ecosystem processes, which implies that the impacts of declining biodiversity on
ecosystem functioning should be strongly influenced by this process. Here we
show, by simultaneously manipulating producer (green algal) and decomposer
(heterotrophic bacterial) diversity in freshwater microcosms, that algal biomass
production varies considerably among microcosms (0.0-0.67 mg ml(-1)), but that
neither algal nor bacterial diversity by itself can explain this variation.
Instead, production is a joint function of both algal and bacterial diversity.
Furthermore, the range in algal production in microscosms in which bacterial
diversity was manipulated was nearly double (1.82 times) that of microcosms in
which bacterial diversity was not manipulated. Measures of organic carbon use by
bacteria in these microcosms indicate that carbon usage is the mechanism
responsible for these results. Because both producer and microbial diversity
respond to disturbance and habitat modification, the main causes of biodiversity
loss, these results suggest that ecosystem response to changing biodiversity is
likely to be more complex than other studies have shown.
PMID- 10693804
TI - The mouse Dreher gene Lmx1a controls formation of the roof plate in the
vertebrate CNS.
AB - In the vertebrate central nervous system (CNS), a cascade of signals that
originates in the ectoderm adjacent to the neural tube is propagated by the roof
plate to dorsalize the neural tube. Here we report that the phenotype of the
spontaneous neurological mutant mouse dreher (dr) results from a failure of the
roof plate to develop. Dorsalization of the neural tube is consequently affected:
dorsal interneurons in the spinal cord and granule neurons in the cerebellar
cortex are lost, and the dorsal vertebral neural arches fail to form. Positional
cloning of dreher indicates that the LIM homeodomain protein, Lmx1a, is affected
in three different alleles of dreher. Lmx1a is expressed in the roof plate along
the neuraxis during development of the CNS. Thus, Lmx1a is required for
development of the roof plate and, in turn, for specification of dorsal cell
fates in the CNS and developing vertebrae.
PMID- 10693805
TI - Forebrain peptides modulate sexually polymorphic vocal circuitry.
AB - The peptide arginine-vasopressin (mammals) and its evolutionary precursor
arginine-vasotocin (non-mammals) modulate reproductive physiology and numerous
related social behaviours, as do oxytocin (mammals) and its homologues mesotocin
and isotocin (fish). The distributions in the brain and/or the behavioural
functions of these peptides often differ between the sexes, and between species
with divergent social structures. Here we present neurophysiological evidence
that males with vocal characteristics typical of females share a pattern of
neuropeptide function with females rather than conspecific males. The plainfin
midshipman fish (Porichthys notatus) has two male morphs with different
reproductive tactics and vocalizations (a key species-typical behaviour which
varies in its physical attributes and contextual usage, depending on the morph's
social strategy). Forebrain-evoked, rhythmic vocal-motor activity that precisely
mimics natural vocalizations was modulated by arginine-vasotocin, isotocin and
their antagonists delivered to the preoptic area-anterior hypothalamus, a primary
site for behavioural integration in all vertebrates. Peptides had different
effects in males that acoustically court females (arginine-vasotocin-sensitive)
than in females and sneak-spawning males (isotocin-sensitive), showing that the
neuromodulatory mechanisms that establish reproduction-related behaviour can be
dissociated from gonadal sex.
PMID- 10693806
TI - Mapping the conformational wave of acetylcholine receptor channel gating.
AB - Allosteric transitions allow fast regulation of protein function in living
systems. Even though the end points of such conformational changes are known for
many proteins, the characteristics of the paths connecting these states remain
largely unexplored. Rate-equilibrium linear free-energy relationships (LFERs)
provide information about such pathways by relating changes in the free energy of
the transition state to those of the ground states upon systematic perturbation
of the system. Here we present an LFER analysis of the gating reaction pathway of
the muscle acetylcholine receptor. We studied the closed <==> open conformational
change at the single-molecule level following perturbation by series of single
site mutations, agonists and membrane voltages. This method provided a snapshot
of several regions of the receptor at the transition state in terms of their
approximate positions along the reaction coordinate, on a scale from 0 (closed
like) to 1 (open-like). The resulting map reveals a spatial gradient of
positional values, which suggests that the conformational change proceeds in a
wave-like manner, with the low-to-high affinity change at the transmitter-binding
sites preceding the complete opening of the pore.
PMID- 10693807
TI - Positional cloning of zebrafish ferroportin1 identifies a conserved vertebrate
iron exporter.
AB - Defects in iron absorption and utilization lead to iron deficiency and overload
disorders. Adult mammals absorb iron through the duodenum, whereas embryos obtain
iron through placental transport. Iron uptake from the intestinal lumen through
the apical surface of polarized duodenal enterocytes is mediated by the divalent
metal transporter, DMTi. A second transporter has been postulated to export iron
across the basolateral surface to the circulation. Here we have used positional
cloning to identify the gene responsible for the hypochromic anaemia of the
zebrafish mutant weissherbst. The gene, ferroportin1, encodes a multiple
transmembrane domain protein, expressed in the yolk sac, that is a candidate for
the elusive iron exporter. Zebrafish ferroportin1 is required for the transport
of iron from maternally derived yolk stores to the circulation and functions as
an iron exporter when expressed in Xenopus oocytes. Human Ferroportin1 is found
at the basal surface of placental syncytiotrophoblasts, suggesting that it also
transports iron from mother to embryo. Mammalian Ferroportin1 is expressed at the
basolateral surface of duodenal enterocytes and could export cellular iron into
the circulation. We propose that Ferroportin1 function may be perturbed in
mammalian disorders of iron deficiency or overload.
PMID- 10693808
TI - Interaction between Wnt and TGF-beta signalling pathways during formation of
Spemann's organizer.
AB - Members of the Wnt and TGF-beta superfamilies regulate both cell fate and
proliferation during development and tissue maintenance. In the early amphibian
embryo, the Wnt and TGF-beta superfamily signalling cascades are required for the
establishment of a dorsal signalling centre, Spemann's organizer. Intracellular
proteins of both pathways, upon activation, translocate to the nucleus to
participate in transcription. Here we show that beta-catenin and Lef1/Tcf, which
are downstream components of the Wnt signalling cascade, form a complex with
Smad4, an essential mediator of signals initiated by members of the TGF-beta
growth factor superfamily. In Xenopus, this interaction directly and
synergistically affects expression of the twin (Xtwn) gene during formation of
the organizer. This is, to our knowledge, the first demonstration of a physical
interaction between TGF-beta and Wnt signalling components in vivo.
PMID- 10693809
TI - Syncytin is a captive retroviral envelope protein involved in human placental
morphogenesis.
AB - Many mammalian viruses have acquired genes from their hosts during their
evolution. The rationale for these acquisitions is usually quite clear: the
captured genes are subverted to provide a selective advantage to the virus. Here
we describe the opposite situation, where a viral gene has been sequestered to
serve an important function in the physiology of a mammalian host. This gene,
encoding a protein that we have called syncytin, is the envelope gene of a
recently identified human endogenous defective retrovirus, HERV-W. We find that
the major sites of syncytin expression are placental syncytiotrophoblasts,
multinucleated cells that originate from fetal trophoblasts. We show that
expression of recombinant syncytin in a wide variety of cell types induces the
formation of giant syncytia, and that fusion of a human trophoblastic cell line
expressing endogenous syncytin can be inhibited by an anti-syncytin antiserum.
Our data indicate that syncytin may mediate placental cytotrophoblast fusion in
vivo, and thus may be important in human placental morphogenesis.
PMID- 10693810
TI - naked cuticle encodes an inducible antagonist of Wnt signalling.
AB - During animal development, cells have to respond appropriately to localized
secreted signals. Proper responses to Hedgehog, transforming growth factor-beta,
epidermal growth factor and fibroblast growth factor/Ras signals require cognate
inducible antagonists such as Patched, Dad, Argos and Sprouty. Wnt signals are
crucial in development and neoplasia. Here we show that naked cuticle (nkd), a
Drosophila segment-polarity gene, encodes an inducible antagonist for the Wnt
signal Wingless (Wg). In fly embryos and imaginal discs nkd transcription is
induced by Wg. In embryos, decreased nkd function has an effect similar to excess
Wg; at later stages such a decrease appears to have no effect. Conversely,
overproduction of Nkd in Drosophila and misexpression of Nkd in the vertebrate
Xenopus laevis result in phenotypes resembling those of loss of Wg/Wnt function.
nkd encodes a protein with a single EF hand (a calcium-binding motif) that is
most similar to the recoverin family of myristoyl switch proteins. Nkd may
therefore link ion fluxes to the regulation of the potency, duration or
distribution of Wnt signals. Signal-inducible feedback antagonists such as nkd
may limit the effects of Wnt proteins in development and disease.
PMID- 10693811
TI - Transcriptional silencing and longevity protein Sir2 is an NAD-dependent histone
deacetylase.
AB - Yeast Sir2 is a heterochromatin component that silences transcription at silent
mating loci, telomeres and the ribosomal DNA, and that also suppresses
recombination in the rDNA and extends replicative life span. Mutational studies
indicate that lysine 16 in the amino-terminal tail of histone H4 and lysines 9,
14 and 18 in H3 are critically important in silencing, whereas lysines 5, 8 and
12 of H4 have more redundant functions. Lysines 9 and 14 of histone H3 and
lysines 5, 8 and 16 of H4 are acetylated in active chromatin and hypoacetylated
in silenced chromatin, and overexpression of Sir2 promotes global deacetylation
of histones, indicating that Sir2 may be a histone deacetylase. Deacetylation of
lysine 16 of H4 is necessary for binding the silencing protein, Sir3. Here we
show that yeast and mouse Sir2 proteins are nicotinamide adenine dinucleotide
(NAD)-dependent histone deacetylases, which deacetylate lysines 9 and 14 of H3
and specifically lysine 16 of H4. Our analysis of two SIR2 mutations supports the
idea that this deacetylase activity accounts for silencing, recombination
suppression and extension of life span in vivo. These findings provide a
molecular framework of NAD-dependent histone deacetylation that connects
metabolism, genomic silencing and ageing in yeast and, perhaps, in higher
eukaryotes.
PMID- 10693812
TI - The structures of HsIU and the ATP-dependent protease HsIU-HsIV.
AB - The degradation of cytoplasmic proteins is an ATP-dependent process. Substrates
are targeted to a single soluble protease, the 26S proteasome, in eukaryotes and
to a number of unrelated proteases in prokaryotes. A surprising link emerged with
the discovery of the ATP-dependent protease HslVU (heat shock locus VU) in
Escherichia coli. Its protease component HslV shares approximately 20% sequence
similarity and a conserved fold with 20S proteasome beta-subunits. HslU is a
member of the Hsp100 (Clp) family of ATPases. Here we report the crystal
structures of free HslU and an 820,000 relative molecular mass complex of HslU
and HslV-the first structure of a complete set of components of an ATP-dependent
protease. HslV and HslU display sixfold symmetry, ruling out mechanisms of
protease activation that require a symmetry mismatch between the two components.
Instead, there is conformational flexibility and domain motion in HslU and a
localized order-disorder transition in HslV. Individual subunits of HslU contain
two globular domains in relative orientations that correlate with nucleotide
bound and unbound states. They are surprisingly similar to their counterparts in
N-ethylmaleimide-sensitive fusion protein, the prototype of an AAA-ATPase. A
third, mostly alpha-helical domain in HslU mediates the contact with HslV and may
be the structural equivalent of the amino-terminal domains in proteasomal AAA
ATPases.
PMID- 10693813
TI - Structure of the intact transactivation domain of the human papillomavirus E2
protein.
AB - Papillomaviruses cause warts and proliferative lesions in skin and other
epithelia. In a minority of papillomavirus types ('high risk, including human
papillomaviruses 16, 18, 31, 33, 45 and 56), further transformation of the wart
lesions can produce tumours. The papillomavirus E2 protein controls primary
transcription and replication of the viral genome. Both activities are governed
by a approximately 200 amino-acid amino-terminal module (E2NT) which is connected
to a DNA-binding carboxy-terminal module by a flexible linker. Here we describe
the crystal structure of the complete E2NT module from human papillomavirus 16.
The E2NT module forms a dimer both in the crystal and in solution. Amino acids
that are necessary for transactivation are located at the dimer interface,
indicating that the dimer structure may be important in the interactions of E2NT
with viral and cellular transcription factors. We propose that dimer formation
may contribute to the stabilization of DNA loops which may serve to relocate
distal DNA-binding transcription factors to the site of human papillomavirus
transcription initiation.
PMID- 10693814
TI - Knowing no fear.
AB - People with brain injuries involving the amygdala are often poor at recognizing
facial expressions of fear, but the extent to which this impairment compromises
other signals of the emotion of fear has not been clearly established. We
investigated N.M., a person with bilateral amygdala damage and a left thalamic
lesion, who was impaired at recognizing fear from facial expressions. N.M. showed
an equivalent deficit affecting fear recognition from body postures and emotional
sounds. His deficit of fear recognition was not linked to evidence of any problem
in recognizing anger (a common feature in other reports), but for his everyday
experience of emotion N.M. reported reduced anger and fear compared with
neurologically normal controls. These findings show a specific deficit
compromising the recognition of the emotion of fear from a wide range of social
signals, and suggest a possible relationship of this type of impairment with
alterations of emotional experience.
PMID- 10693815
TI - Anti-predator behaviour changes following an aggressive encounter in the lizard
Tropidurus hispidus
AB - Avoiding predators may conflict with territorial defence because a hiding
territorial resident is unable to monitor its territory or defend it from
conspecific intrusions. With persistent intruders, the presence of an intruder in
the near past can indicate an increased probability of future intrusions.
Therefore, following a conspecific-intrusion, territorial residents should
minimize costs from future intrusions at the cost of higher predation risks. I
conducted experiments with males of the territorial lizard Tropidurus hispidus
recording approach distance (distance between predator and prey when the prey
escapes) and time to re-emergence from a refuge after hiding. Past aggressive
interactions affected anti-predator behaviour: lizards re-emerged sooner
(compared to a control) when the predator attacked 5 min after an aggressive
encounter. If the predator attacked while an aggressive encounter was ongoing,
there was also a reduction in approach distance. The results are consistent with
an economic hypothesis which predicts that T. hispidus incur greater predation
risks to minimize future territorial intrusion; additionally they show that the
effects of past and ongoing aggressive interactions are different, consistent
with the minimization of present intrusion costs. These results are relevant for
studies of the changes in aggressive behaviour due to changes in the social
environment and for studies of the costs and (co) evolution of aggressive and
anti-predator strategies.
PMID- 10693816
TI - Regulation of queen-worker conflict in bumble-bee (Bombus terrestris) colonies
AB - In annual colonies of bumble-bees overt queen-worker conflict is limited to a
distinct 'competition phase' (CPh). In unmanipulated Bombus terrestris colonies,
the queen's switch to male production (the 'switch point', SP) accounted for only
22% of the variation in the onset of the CPh. In some colonies, the CPh even
began before the SP. The CPh was more strongly correlated with the transition in
queen production (r=0.79). Replacing the queen eggs with male eggs or doubling
the number of workers in young colonies resulted in a significantly earlier onset
of the CPh and a significantly earlier transition to queen production. Replacing
queen eggs with female eggs did not have this effect. These manipulations did not
affect the timing of the queen's switch from female to male production. These
findings show that the mechanism underlying the queen-worker conflict in insect
societies is more complex than previously appreciated. The onset of queen-worker
conflict cannot be attributed simply to a single factor such as the queen's
switch to male production or a decrease in queen inhibition. Rather, multiple
cues are important.
PMID- 10693817
TI - An uncoupling of male and sexual egg production leads to reduced inbreeding in
the cyclical parthenogen Daphnia
AB - Cyclical parthenogenesis involves an alternation of parthenogenetic and sexual
reproduction. In cyclical parthenogens with a short generation time, seasonal
succession of clones switching to sexual reproduction at different periods of the
growing season entails the risk of severe inbreeding with associated fitness
costs. We show, however, that differences in genotype frequencies between males
and sexual females result in a substantial reduction in the probability of
selfing in natural Daphnia populations. This suggests that responses to male- and
sexual egg-inducing stimuli may be uncoupled at the level of individual clones as
a mechanism to avoid severe inbreeding.
PMID- 10693818
TI - Sex differences in energy expenditure in non-human primates.
AB - Female mammals bear the energetic costs of gestation and lactation. Therefore, it
is often assumed that the overall energetic costs are greater for females than
they are for males. However, the energetic costs to males of intrasex competition
may also be considerable, particularly if males maintain a much larger body size
than females. Using data from 19 non-human primates, this paper examines the
relationship between male and female energetic costs both in the short term
(daily energy expenditure) and the long term (the energetic cost of producing a
single offspring). It is shown that the major determinant of sex differences in
energetic costs is body size dimorphism. In the long term, the energetic costs
are often greater for females, but, when male body size exceeds female body size
by 60% or more, male energetic costs are greater than those for females. That is,
in highly sexually dimorphic species the energetic costs of gestation and
lactation for the females are matched by the energetic costs to the males of
maintaining a large body size.
PMID- 10693819
TI - Climate change has affected the breeding date of tree swallows throughout North
America
AB - Increasing evidence suggests that climate change has affected the breeding and
distribution of wildlife. If such changes are due to global warming, then we
should expect to see large-scale effects. To explore for such effects on avian
reproduction, we examined 3450 nest records of tree swallows from across North
America. The egg-laying date in tree swallows advanced by up to nine days during
1959-1991. This advance in phenology was associated with increasing surface air
temperatures at the time of breeding. Our analysis controlled for several
potentially confounding variables such as latitude, longitude, breeding density
and elevation. We conclude that tree swallows across North America are breeding
earlier and that the most likely cause is a long-term increase in spring
temperature.
PMID- 10693820
TI - Joint effects of feeding and breeding behaviour on trophic dimorphism in
hummingbirds
AB - A survey of 166 hummingbird species reveals novel associations of bill-length
sexual dimorphism (BLSD) with plumage and breeding behaviours. Across all
species, female bills become proportionately longer than male bills (higher
female-to-male BLSD ratio) as sexual dichromatism increases. However, male bills
are proportionately longer (lower female-to-male BLSD ratio) in both lekkers
(traditional group display) and clustered breeders (female harems or colonial
nests) compared with dispersed breeders. The overall positive association of
plumage with BLSD suggests that social status determines priority of access to
nectar-providing flowers. Furthermore, the distinctive BLSD associated with
breeding aggregations may arise from behaviours that impose constraints on the
usual male priority at flowers: female dominance over males around nest colonies
and male residence on lek-mating territories. These various factors appear to
alter plumage and bill characters of both sexes to produce the range of
dimorphisms within the various dispersed and aggregated breeding system
categories. Feedback loops caused by ecological consequences of breeding
behaviour may alter the evolutionary dynamics of breeding systems, bird-plant
interactions, and competing pollinators, as well as help explain the lek paradox.
PMID- 10693821
TI - Bird orientation at high latitudes: flight routes between Siberia and North
America across the Arctic Ocean
AB - Bird migration and orientation at high latitudes are of special interest because
of the difficulties associated with different compass systems in polar areas and
because of the considerable differences between flight routes conforming to
loxodromes (rhumblines) or orthodromes (great circle routes). Regular and
widespread east-north-east migration of birds from the northern tundra of Siberia
towards North America across the Arctic Ocean (without landmark influences) were
recorded by ship-based tracking radar studies in July and August. Field
observations indicated that waders, including species such as
Phalaropusfulicarius and Calidris melanotos, dominated, but also terns and skuas
may have been involved. Analysis of flight directions in relation to the wind
showed that these movements are not caused by wind drift. Assuming possible
orientation principles based on celestial or geomagnetic cues, different flight
trajectories across the Arctic Ocean were calculated: geographical loxodromes,
sun compass routes, magnetic loxodromes and magnetoclinic routes. The
probabilities of these four alternatives are evaluated on the basis of both the
availability of required orientation cues and the predicted flight paths. This
evaluation supports orientation along sun compass routes. Because of the
longitudinal time displacement sun compass routes show gradually changing compass
courses in close agreement with orthodromes. It is suggested that an important
migration link between Siberia and North American stopover sites 1000-2500km
apart across the Arctic Ocean has evolved based on sun compass orientation along
orthodrome-like routes.
PMID- 10693822
TI - Evolution of stepping-stone dispersal rates.
AB - We present a general model of the evolution of dispersal in a population with any
distribution of dispersal distance. We use this model to analyse evolutionarily
stable (ES) dispersal rates for the classical island model of dispersal and for
three different stepping-stone models. Using general techniques to compute
relatedness coefficients in the different dispersal models which we consider, we
find that the distribution of dispersal distance may affect the ES dispersal rate
when the cost of dispersal is low. In this case the ES dispersal rate increases
with the number of demes that can be reached by one dispersal event. However, for
increasing cost the ES dispersal rate converges to a value independent of the
distribution of dispersal distance. These results are in contrast to previous
analyses of similar models. The effects of the size (number of demes) and shape
(ratio between the width and the length) of the population on the evolution of
dispersal are also studied. We find that larger and more elongated populations
lead generally to higher ES dispersal rates. However, both of these effects can
only be observed for extreme parameter values (i.e. for very small and very
elongated populations). The direct fitness method and the analytical techniques
used here to compute relatedness coefficients provide an efficient way to analyse
ES strategies in subdivided populations.
PMID- 10693823
TI - The immunocompetence handicap hypothesis: testing the genetic predictions
AB - The immunocompetence handicap hypothesis suggests that the immune system competes
for resources with sexually selected ornaments; variation in ornaments might
reflect genetic variation for immunocompetence. We tested this genetic prediction
by mating scorpionfly females to males differing in the expression of a condition
dependent ornament trait, saliva secretion, and then comparing offspring
immunocompetence. We found several indications of an immunocompetence handicap in
our study: females had superior immunocompetence compared with males, the
different immune traits were positively correlated, and there were indications of
genetic variation in immune traits. However, we found no significant difference
in the immunocompetence of offspring derived from males differing in ornament
expression, only a tendency for sons of ornamented males to possess slightly
better immunocompetence. The estimated effect of fathers on offspring
immunocompetence was rather small, but it might be a sufficient benefit of female
choice, provided that the costs of choice are small. We conclude that the genetic
benefit of female choice is small concerning offspring immunocompetence, but the
immunocompetence handicap principle might nevertheless work in scorpionflies.
PMID- 10693824
TI - Virus phenotype switching and disease progression in HIV-1 infection.
AB - One of the phenotypic distinctions between different strains of human
immunodeficiency virus type 1 (HIV-1) has to do with the ability to cause target
cells to form large multinucleate bodies known as syncytia. There are two
phenotypes according to this characterization: syncytium-inducing (SI) and non
syncytium-inducing (NSI). NSI strains are usually present throughout infection,
while SI strains are typically seen at the beginning of the infection and near
the onset of AIDS. The late emergence of SI strains is referred to as phenotype
switching. In this paper we analyse the factors that lead to phenotype switching
and contribute to the dynamics of disease progression. We show that a strong
immune system selects for NSI strains while a weak immune system favours SI
strains. The model explicitly accounts for the fact that CD4+ cells are both
targets of HIV infection and crucial for activating immune responses against HIV
In such a model, SI strains can emerge after a long and variable period of NSI
dominated infection. Furthermore, versions of the model which do not explicitly
account for HIV-specific, activated CD4+ cells do not exhibit phenotype
switching, emphasizing the critical importance of this pool of cells.
PMID- 10693825
TI - Scrapie transmission in Britain: a recipe for a mathematical model.
AB - Responses to an anonymous postal survey concerning scrapie are analysed. Risk
factors associated with farms that have had scrapie are identified as size,
geographical region, lambing practices and holding of certain breeds. Further
analysis of farms that have scrapie only in bought-in animals reveals that such
farms tend to breed a smaller proportion of their replacement animals than farms
without scrapie. Farms that have had scrapie in home-bred animals have attributes
associated with breeding many animals: large numbers of rams bought, few ewes
bought, and many animals that are home-bred. The demography of British sheep
farms as described by size, breeds, purchasing behaviour, age structure and
proportion of animals that are home-bred is summarized. British farms with
scrapie reveal certain special features: they have more sheep that are found
dead, more elderly ewes and more cases of scab.
PMID- 10693826
TI - Invasion thresholds for fungicide resistance: deterministic and stochastic
analyses
AB - Fungicide resistance is an important practical problem, but one that is poorly
understood at the population level. Here we introduce a simple nonlinear model
for fungicide resistance in botanical epidemics which includes the dynamics of
the chemical control agent and the host population, while also allowing for
demographic stochasticity in the host-parasite dynamics. This provides a
mathematical framework for analysing the risk of fungicide resistance developing
by including the parameters for the amount applied, longevity and application
frequency of the fungicide. The model demonstrates the existence of thresholds
for the invasion of the resistant strain in the parasite population which depend
on two quantities: the relative fitness of the resistant strain and the
effectiveness of control. This threshold marks a change from definite elimination
of the resistant strain below the threshold to a finite probability of invasion
which increases above the threshold. The fungicide decay rate, the amount of
fungicide applied and the period between applications affect the effectiveness of
control and, consequently, they influence whether or not resistance develops and
the time taken to achieve a critical frequency of resistance. All three
parameters are amenable to control by the grower or by coordinating the activity
of a population of growers. Providing crude estimates of the effectiveness of
control and relative fitness are available, the results can be used to predict
the consequences of changing these parameters for the risk of invasion and the
proportion of sites at which this might be expected to occur. Although motivated
for fungicide resistance, the model has broader application to herbicide,
antibiotic and antiviral resistance. The modelling approach and results are
discussed in the context of resistance to chemical control in general.
PMID- 10693827
TI - Validity of self-reported duration of work postures obtained by interview. MUSIC
Norrtalje Study Group.
AB - The aim of the study was to validate interview data concerning the duration of
four work postures (1) sitting, (2) standing/walking with hands above shoulder
level, (3) standing/walking with hands between shoulder and knuckle level, and
(4) standing/walking with hands below knuckle level. The self-reported time spent
in each posture was tested in relation to observations and technical measurements
in 20 subjects during two full working days. The linear relationships between
self-reports and observations were strong for the three postures; sitting (r2 =
0.55), hands above shoulder level (r2 = 0.58) and hands below knuckle level (r2 =
0.69). Thus, using this interview technique, self-reports concerning time spent
in (1) sitting, (2) standing/walking with hands above shoulder level and, (3)
standing/walking with hands below knuckle level may be accurate enough for
studying these work postures in epidemiological studies.
PMID- 10693828
TI - An ergonomic design and performance evaluation of pipettes.
AB - This paper describes the results of an investigation of the differences in
performance, postures, strains on hand-arm-shoulder musculature, and subjective
ratings of three pipettes (models A, B, and C). Both models A and B were pipettes
available on the market. Model C was developed for this study of an ergonomically
designed pipette. The gripping posture of the three models was distinct both in
the anatomical and in the functional sense. Working with models A and B required
a four-finger grasp with a thumb operated plunger. Model C required a finger
palmar power grip and the plunger was operated by the fingers. Performance
evaluation of the different pipettes in different tasks indicated that using the
proposed model C resulted in a 2-3% lower fault rate, a 10% shorter completion
time, and the highest subjective ratings among the three. Postural analysis
results indicated that when using model C, the shoulder was the least abducted,
the wrist was the least extended, and the wrist was the least radially extended.
Model C appeared to provide the greatest opportunity for delicate adjustments of
posture in response to the activity of the skin receptors and reduced the strains
on the upper body musculature, justifying the ergonomic input into the design.
PMID- 10693829
TI - Assessment of workload and arm position during different work sequences: a study
with portable devices on construction workers.
AB - It is recognised that work related shoulder pain is overrepresented among
construction workers compared to other occupations. Studies have shown that
working with hands above shoulder level increases the shoulder load. Most studies
have been confined to the laboratory. The present project was carried out to map
the muscular engagement and postures of construction workers undertaking ceiling
fitting, and to compare the results to those of the laboratory studies. Two
ambulatory devices were used, one allowing recording of electromyographic (EMG)
signals bilaterally from the trapezius muscle, and the other to record the
position of both arms and back by means of measuring the angles between the
vertical line and the back and both upper arms. These recordings were performed
during 1.5-2 h work sequences. The results show that the work was mostly
performed in an upright position, that both arms were used to a similar amount
and that the workers for a large proportion of their working time had their upper
arms at levels that are considered harmful in view of shoulder load. The EMG data
showed that nearly 50% of the work was spent with trapezius activity that
exceeded that of the reference contraction used (about 15% of maximal voluntary
contraction) and that the time spent in muscular relaxation was 10%. It was
concluded that the exposure of construction workers undertaking ceiling fitting
meets the criteria formulated on the basis of laboratory experiments with respect
to a high risk of acquiring chronic shoulder pain, due to rotator cuff
tendinitis.
PMID- 10693830
TI - The significance of lateral whole-body vibrations related to separately and
simultaneously applied vertical motions. A validation study of ISO 2631.
AB - Sensitivity of lateral motions relative to vertical motions were determined and
compared to predictions provided by ISO 2631. Two experiments were executed where
lateral and vertical motions were applied consecutively or simultaneously and
where the magnitude of a single- or dual-axis test signal was adjusted until it
was judged as equivalent to a preceding single-axis reference motion of the same
frequency. Experiment 1: References consisted of vertical sinusoidal motions
presented with 1.6-12.5 Hz and weighted accelerations of a(zw) = 0.3, 0.6 and 1.2
m s(-2) r.m.s., single-axis test signals were lateral motions of the same
frequency. 26 subjects (15 men, 11 women, 20-56 yr) participated in the
experiments. Accelerations adjusted for lateral vibrations above 1.6 Hz were
considerably lower than predicted suggesting that the weighting factors provided
in ISO 2631 are incorrect. Experiment 2: References consisted of single-axis
vertical or lateral sinusoidal motions presented with 1.6-12.5 Hz and a weighted
acceleration of a(zw) = 1.25 m s(-2) r.m.s. The dual-axis test signals consisted
of a constant fraction of the reference acceleration (10, 25, 50, 75, 90%) and a
perpendicularly oriented adjustable component. 31 subjects (15 men, 16 women, 19
51 yr) participated in the experiments. Both experiments revealed that ISO 2631
is qualitatively valid, the weighting of lateral motions above 1.6 Hz, however,
should be increased in order to meet the actual sensitivity particularly in case
of multi-axis vibrations.
PMID- 10693831
TI - Maximum isometric trunk muscle strength and activity at trunk axial rotation
during sitting.
AB - This study was performed to provide information relating to the twisted posture
being characteristic of the driver of an agricultural tractor working in the
field. The relationship of trunk axial strength and muscle activity to trunk
twisting angle of prerotation was determined and quantified. Differences between
tractor drivers and office workers, and between the two directions of twisting
action were also studied. Nine male tractor drivers and nine male office workers
performed isometric maximum efforts at about -40, -20, 0, 20 and 40 degrees of
pre-set trunk twisting angles in both the clockwise and counterclockwise
directions. Exerted torque, true angle of prerotation and muscle activity from
left and right side of each of obliquus externus, rectus abdominis and erector
spinae were measured simultaneously. The results showed that the subjects could
exert the greatest torques when being prerotated in the opposite direction and
the lowest torques when being prerotated in the same direction to the direction
of exertion. The exerted torques were within the range of 65-145 Nm. There were
large differences in obliquus externus and erector spinae activity due to the
twisting direction. There were also changes in muscle activity from obliquus
externus and rectus abdominis due to prerotation angle. The results raised
questions concerning the involvement of the passive tissues and the use of deeper
muscles during trunk axial rotation, which should be further investigated.
PMID- 10693832
TI - Wrist positions and movements as possible risk factors during machine milking.
AB - High prevalence of hand and wrist symptoms has been found in females working with
machine milking. Therefore the aim of this study was to quantify the positions
and movements of the wrist during machine milking, and to compare tethering and
loose-housing systems with respect to this. Biaxial electrogoniometers and data
loggers were used for recording flexion and deviation angles of both the right
and left wrists in 11 healthy milkers. For each individual 25 min of
representative work was recorded in each system. High values of dorsiflexion and
radial deviation were found, which might induce an increased risk of carpal
tunnel syndrome. Moreover, the velocity and repetitiveness were close to those
values described in repetitive work with a high risk of elbow and hand disorders
in the fish-processing industry and giro-form data entry work. According to our
findings, the load on the upper extremities has increased with respect to
dorsiflexed hand position and repetitiveness when milking in the modern loose
housing milking system. This is probably due to the change of the working
position and/or the higher productivity (number of cows that milked per time
unit) in the loose-housing system as compared to the old-fashioned tethering
system. These negative effects on wrist positions and movements should be
considered when building new milking systems.
PMID- 10693833
TI - Applying ergonomics to Applied Ergonomics: using structured abstracts.
AB - BACKGROUND: Previous research with structured abstracts (i.e. those that contain
sub-headings such as this one) has indicated that structured abstracts are of a
higher quality, contain more information, and are easier to search than are
abstracts produced in the traditional manner. AIM: The aim of this article is to
indicate how such structured abstracts might be appropriate for Applied
Ergonomics. METHOD: Three abstracts taken from a recent issue of Applied
Ergonomics were re-written in a structured form. This involved re-sequencing the
information presented in the originals, and including additional information-
particularly that of a quantitative kind--to meet the requirements of the sub
headings. Measures of word length, information content, readability, and reader
preferences were then made. RESULTS: The results showed that there were
differences between the three pairs of abstracts on these various measures but
that, overall, in line with previous research, the structured abstracts were
longer, more informative and judged to be clearer by their readers. COMMENT: The
findings support the author's view that structured abstracts are more effective
than traditional ones.
PMID- 10693834
TI - Development and evaluation of a microprocessor-based ergonomic dosimeter for
evaluating carpentry tasks.
AB - This portable and self-contained lightweight microprocessor based Ergonomic
Dosimeter is designed to collect continuously postural angles of the torso and
the upper arm in the sagittal plane and the number of kneeling activities. Up to
4 h of task performance data can be stored in a non-volatile memory of the
dosimeter, which can then be downloaded to a lap-top computer. The portable
dosimeter was tested for test-retest reliability, compared with posture data
obtained with a computer-based video analysis system and evaluated at a
carpenter's apprentices school and at a construction site. The dosimeter was
shown to be suitable for collecting posture and kneeling data for a prolonged
period at construction sites.
PMID- 10693835
TI - The development and evaluation of an ergonomic glove.
AB - The primary intent of this study was to determine if a hand glove could be
designed on a criterion of selective protection. Force distribution patterns on
the palmar side of hand were obtained from various studies to develop zones of
hand that needed protection. A new design for gloves was developed based on the
principle of selective protection, where protective material is introduced in
varying levels over different parts of the glove, in order to provide protection
where it is most needed, and at the same time preserve the desirable dexterity
and strength capabilities of the barehand, optimizing the trade-off between
protection and performance. Two pairs of prototype gloves incorporating different
levels of protection were fabricated and tested using a battery of performance
tests and an algometer test for pressure sensitivity. The test battery comprising
four dexterity tasks and a maximal voluntary grip strength task was used to
assess a number of glove conditions, including the two prototype gloves
developed. The results indicate that the performance of the prototype gloves are
comparable, and that the performance times for the double glove and the two
prototype gloves tested were not significantly different. For the grip strength,
the two prototype gloves were better than the double glove. The assembly task
performance for the prototype II (laminar glove) was significantly lower than
that of the other glove types tested. It appears that gloves of variable
thickness can be developed to afford adequate protection at zones of most need.
Glove manufacturers are recommended to use an ergonomic approach in the design of
gloves. Such an approach, besides protecting the safety objective of gloves,
could enhance productivity considerably.
PMID- 10693836
TI - Ergonomics evaluation of a manually operated cassava chipping machine.
AB - A manually operated machine for chipping cassava was evaluated. Six farmers took
part in the study, with physiological, postural, and subjective measurements
being taken. Using the machine resulted in drudgery and postural discomfort.
Following an iterative design process and using appropriate anthropometric
measurements, an improved, adjustable prototype was developed. This was tested
with the six farmers and six novice users. It was found to reduce discomfort and
physiological strain, allowed a faster work-rate (with novice users) and was
preferred by all users. The study demonstrated how ergonomics can play an
important role in reducing drudgery and improving user satisfaction in technology
development and transfer in developing countries.
PMID- 10693837
TI - Overlooked issues in Time to Heal essays.
PMID- 10693839
TI - Behold the patient-safety genie.
PMID- 10693838
TI - The relevance of community-oriented primary care for training preventive medicine
residents.
PMID- 10693840
TI - Collaborative care: a new model for a new century.
AB - From the imagined vantage point of the year 2020, the author recounts the
problems and deficiencies of health care in the 1990s and describes how academic
medicine's leaders successfully confronted them. A key part of their strategy was
to work together to form a coordinated network of medical schools, teaching
hospitals, and academically oriented health systems, along with their staffs and
a variety of community-based partners. In this way, they set a national agenda,
pursued common goals, freely shared information and best practices, and
cooperated to optimize their effectiveness in education, research, and clinical
care. A major outcome of this new network was the Collaborative Care model of
health care, based on the premise that a basic purpose of the health care system
is to achieve measurable improvements in the health of individuals and
communities in ways that are cost-conscious, quality-driven, evidence-based, and
patient-, family-, and community-oriented. Academic institutions formed strong
partnerships with many stakeholders (e.g., purchasers of health care services) to
make the Collaborative Care approach work. In addition, there were several other
important keys to Collaborative Care's success, such as the full integration of
clinical research with clinical care and the restoration of trust in the health
care enterprise. The author returns to reality and the 1990s. He challenges
academic medicine to pursue the Collaborative Care vision, saying that "we should
not accept without challenge what we know to be abominable just because it
appears to be inevitable.... Our choice is to continue to struggle for survival
as the environment around us gets harsher and harsher ... or to fix the
environment" using the power of collaboration to unleash academic medicine's
unlimited creativity and wisdom.
PMID- 10693841
TI - Educating future physicians for Ontario: phase II.
AB - In 1990, a collaborative project was launched to determine what the people of
Ontario expect of their physicians and how the programs that prepare future
physicians should be changed in response. The project, called Educating Future
Physicians for Ontario (EFPO), brought together the five Ontario medical schools,
the Council of Ontario Faculties of Medicine (COFM); a nonprofit, charitable
organization, Associated Medical Services (AMS); and the Ontario Ministry of
Health. The first phase ran for five years and was described in the November 1998
issue of Academic Medicine. After an external review, the project was continued
for a second phase (EFPO II) for four more years until December 1998; that second
phase is the topic of this article. EFPO II (1) focused more on residents'
education; (2) emphasized four of the EFPO I-created physician roles in project
activities; (3) maintained the province-wide, inter-institutional medical
education framework of phase I, but fostered greater involvement of the seven
sites (five medical schools and two regional health centers) in project
activities; (4) stressed five project components (e.g., needs assessment and
community partnerships) and worked for collaboration among components at all
sites; (5) enhanced the original EFPO I Fellowship Program by adding residents
and community fellows to the existing fellowships and by initiating leadership
development activities, all of which bode well for the future leadership of
medical education in Ontario. Students and residents played a vital role in EPFO
II. Most of EFPO II's objectives were met, but the overall view of external
reviewers was that the project was less successful than EFPO I. For example, the
impact on clinical education, especially residency education, was less than
anticipated. On the other hand, the project helped encourage the wide adoption of
the eight physician roles that originated in EFPO I and advanced faculty
development and assessment activities based on these roles. A third phase of EFPO
concerning continuing medical education was planned, but support was not
available. However, one of the funders will continue to support the successful
fellowship and leadership program and the provincial education network for the
next three years. Overall, the two phases of EFPO substantially modified medical
education in Ontario to make it more responsive to evolving social needs.
PMID- 10693842
TI - The ethics of caring and medical education.
AB - The ethics of caring, though the subject of much recent discussion by
philosophers, has hardly been applied to medical ethics and medical education.
Based on receptivity (that is, empathy and compassion) toward and taking
responsibility for other persons, the ethics of caring has particular relevance
to medicine. Caring guides the physician always to remain the patient's advocate
and to maintain the therapeutic relationship when dealing with and resolving
ethical dilemmas. This article discusses the philosophy behind the ethics of
caring and then explores three issues that arise within its context: receptivity,
taking responsibility, and creating an educational environment that fosters
caring.
PMID- 10693843
TI - Programs for the development of physician leaders: a curricular process in its
infancy.
AB - Physician leaders are crucial as never before to ensure the proper integration of
good care and cost containment; such integration is both a reasonable expectation
of patients and essential for the survival of health care delivery systems. In
today's health care environment, a critical mass of physician leaders must be
developed in a systematic fashion so that physicians may truly lead the health
care enterprise. The authors (1) describe, with examples, the various types and
levels of physician leadership training programs currently being offered; (2)
explain the costs and benefits of each program type; and (3) offer a program
rationale and model (using a program at their medical school), which they analyze
using traditional management concepts such as strategic planning, net present
value, and make-versus-buy. The authors emphasize that physician leadership
training should be local, offer long-term instruction, and be led by physicians.
They conclude by stating that the concept of physician leadership will not and
should not be taken seriously by non-physician health care executives until the
physician community becomes as serious about leadership and management training
as it is about clinical training.
PMID- 10693845
TI - Defining educational objectives at the University of Virginia.
PMID- 10693844
TI - The path to professionalism: cultivating humanistic values and attitudes in
residency training.
AB - Though few question the importance of incorporating professionalism and humanism
in the training of physicians, traditional residency programs have given little
direct attention to the processes by which professional and humanistic values,
attitudes, and behaviors are cultivated. The authors discuss the underlying
philosophy of their primary care internal medicine residency program, in which
the development of professionalism and humanism is an explicit educational goal.
They also describe the specific components of the program designed to create a
learner-centered environment that supports the acquisition of professional
values; these components include a communication-skills training program,
challenging-case conferences, home visits with patients, a resident support
group, and a mentoring program. The successful ten-year history of the program
shows how a residency program can enable its trainees to develop not only the
requisite excellent diagnostic and technical tools and skills but also the humane
and professional attributes of the fully competent physician.
PMID- 10693846
TI - The use of an automatic projector for a collateral film course in community
health.
PMID- 10693847
TI - Medicine and the arts. Girl, Interrupted.
PMID- 10693848
TI - Specialty choices, compensation, and career satisfaction of underrepresented
minority faculty in academic medicine.
AB - PURPOSE: Despite efforts to increase the numbers of underrepresented minorities
(URMs), only 3.9% of medical school faculty are URMs. The authors compared the
specialty choices, compensation, and career satisfaction of minority faculty with
those of their majority counterparts to determine whether there were differences
that might affect the recruitment and retention of minority faculty. METHOD: In
1995, the authors mailed a self-administered survey to a stratified random sample
of 3,013 eligible full-time salaried faculty in 24 randomly selected medical
schools. Those schools, which had at least 200 faculty, did not include the
Puerto Rican or historically black medical schools. RESULTS: Of the eligible
faculty surveyed, 1,807 (60%) responded; 1,463 were majority faculty, 195 were
URM faculty, and 149 were other-minority faculty. Similar proportions of the
three groups were in the primary care specialties. Only 11% of the URM
respondents were in basic science departments. There was no significant
difference in adjusted mean compensation between majority, URM, and other
minority faculty. However, URM faculty were significantly less satisfied with
their careers (adjusted scores: 60 versus > 65; p = .001) and more often
considered leaving academic medicine within five years (58% versus < 45%).
CONCLUSION: Given the demographic changes of the U.S. population, these issues
should be addressed by deans and department heads in order to enhance recruitment
and facilitate retention of URM faculty in academic medicine.
PMID- 10693849
TI - Developing and testing an instrument to measure the effectiveness of clinical
teaching in an academic medical center.
AB - PURPOSE: Instruments that rate teaching effectiveness provide both positive and
negative feedback to clinician-educators, helping them improve their teaching.
The authors developed the Clinical Teaching Effectiveness Instrument, which was
theory-based and generic across their entire academic medical center, The
Cleveland Clinic Foundation. They tested it for reliability, validity, and
usability. METHOD: In 1997, using an iterative qualitative development process
involving key stakeholders, the authors developed an institution-wide instrument
to routinely evaluate clinical faculty. The resulting instrument has 15 questions
that use a five-point evaluation scale. The instrument, which was administered to
medical students, residents, and fellows over a 20-month period, produced data
that were rigorously tested for instrument characteristics, reliability,
criterion-related and content validity, and usability. RESULTS: This instrument,
implemented in all departments across the institution, produced data on a total
of 711 clinician-educators. Correlation coefficients among the items were high
(.57 to .77). The scores were reliable (g coefficient of 0.935), and the
instrument had both content and criterion-related validity. CONCLUSIONS: The
Cleveland Clinic's Clinical Teaching Effectiveness Instrument is reliable and
valid, as well as usable. It can be used as an evaluation tool for a wide variety
of clinical teaching settings.
PMID- 10693850
TI - Assessing how well three evaluation methods detect deficiencies in medical
students' professionalism in two settings of an internal medicine clerkship.
AB - PURPOSE: To compare the performances of three evaluation methods in detecting
deficiencies of professionalism among third-year medical students during their
ambulatory care and inpatient ward rotations of a core internal medicine
clerkship. METHOD: From 1994 to 1997, 18 students at The Uniformed Services
University of the Health Sciences failed to satisfactorily complete their core 12
week third-year internal medicine clerkship due to deficiencies in
professionalism. Three evaluation methods had been used to assess all students'
professionalism during the two rotations of their clerkship: standard checklists,
written comments, and comments from formal evaluation sessions. Using qualitative
methods and the information obtained by the three evaluation methods, the authors
abstracted the record of each student concerning his or her clerkship behavior in
terms of the six domains of professionalism used on the standard checklist. A
detection index, which is the percentage of all instructors' less-than-acceptable
ratings of a student across the six professionalism domains, was calculated for
each evaluation method for each of the two clerkship settings. RESULTS: For each
evaluation method, deficiencies in professionalism were twice as likely to be
identified during the ward rotation as during the ambulatory care rotation (p <
.002 for all). Formal evaluation session comments had the highest detection index
in both clinical settings. Although the numbers of written and formal evaluation
session comments per evaluator and per cited professionalism domain were similar,
nearly a fourth of the instructors made identifying comments at the evaluation
sessions only. CONCLUSION: In the clerkship studied, deficiencies in
professionalism of such magnitude as to require remediation were more likely to
be identified in the inpatient than in the ambulatory care setting. Of the three
evaluation methods studied, the face-to-face, formal evaluation sessions
significantly improved the detection of unprofessional behavior in both clerkship
settings. Further efforts at such an interactive evaluation process with
ambulatory care clerkship instructors may be essential for improving the
identification of unprofessional behavior in that setting.
PMID- 10693851
TI - Results of remedial continuing medical education in dyscompetent physicians.
AB - PURPOSE: Noticing that moderately to severely incompetent physicians (as measured
by a standardized assessment of physician competence) did not improve after
traditional remedial continuing medical education (CME), the authors investigated
the effects of a polyvalent, intensive, prolonged educational intervention on
five physicians' competence. METHOD: The five physicians participated in a CME
program that lasted three years and consisted of individualized review, ongoing
small-group and evidence-based discussions, simulated patients and role playing,
formal chart review, and peer review. At the end of the program, the physicians
were reassessed. RESULTS: Only one physician improved; another remained the same,
and three deteriorated. CONCLUSION: Successful remediation of severely
incompetent physicians is uncertain at best, even with prolonged, intensive CME
that incorporates modalities thought to be effective in changing physicians'
behaviors. Alternative educational techniques may need to be developed for this
select population. Conversely, there may be reasons that preclude improvement
even with optimal techniques.
PMID- 10693852
TI - Cognitive difficulty in physicians.
AB - PURPOSE: Remediation of some incompetent physicians has proven difficult or
impossible. The authors sought to determine whether physicians with impaired
competency had neuropsychological impairment sufficient to explain their
incompetence and their failure to improve with remedial continuing medical
education (CME). METHOD: During a one-year period, 1996-97, all 27 participants
in the Physician Review Program (PREP) conducted at McMaster University, a
physician competency assessment program, undertook a detailed neuropsychological
screening battery. RESULTS: Nearly all physicians assessed as competent also
performed well on the neuropsychological testing. However, a significant number
(about one third) of the physicians who performed poorly on the competency
assessment had neuropsychological impairments sufficient to explain their poor
performances. The difficulties were more marked in elderly physicians.
CONCLUSION: A significant minority of incompetent physicians have cognitive
impairments sufficient to explain both their incompetence and, probably, their
failure to improve with remedial CME. Testing physicians for these impairments is
important: to detect and treat reversible conditions, to manage irreversible
conditions that preclude successful educational intervention, and to facilitate
compensation in this instance. Serious consideration should be given to the
incorporation of neuropsychological screening in all intensive physician review
programs.
PMID- 10693853
TI - Medicine and industry, medicine as industry.
PMID- 10693854
TI - Scripts and medical diagnostic knowledge: theory and applications for clinical
reasoning instruction and research.
AB - Medical diagnosis is a categorization task that allows physicians to make
predictions about features of clinical situations and to determine appropriate
course of action. The script concept, which first arose in cognitive psychology,
provides a theoretical framework to explain how medical diagnostic knowledge can
be structured for diagnostic problem solving. The main characteristics of the
script concept are pre-stored knowledge, values acceptable or not acceptable for
each illness attribute, and default values. Scripts are networks of knowledge
adapted to goals of clinical tasks. The authors describe how scripts are used in
diagnostic tasks, how the script concept fits within the clinical reasoning
literature, how it contrasts with competing theories of clinical reasoning, how
educators can help students build and refine scripts, and how scripts can be used
to assess clinical competence.
PMID- 10693855
TI - Teaching internal medicine residents about medical problems in pregnancy.
AB - When they became aware that many of their internal medicine residents were not
being routinely exposed to a representative range of medical illnesses in
pregnancy, the authors set out to develop and implement a brief practical
curriculum on the medical problems of pregnancy. They began with a retrospective
chart review of 562 consultations with pregnant women and used their findings to
develop nine 15-minute lectures that covered a majority of the concepts essential
to the care of the medically compromised pregnant woman. Topics included
hypertension in pregnancy, the febrile pregnant woman, and renal disease in
pregnancy. The authors also created a learner handout, a teaching script,
teaching cases, and a bibliography for each lecture. Residents have responded
well to the curriculum, and their mean pre- and posttext scores have shown that
the lectures improved their knowledge of obstetric medicine. This brief-lecture
format may be adapted to other special topics in residency training and readily
integrated into already-crowded training schedules.
PMID- 10693856
TI - The academic medical center of the future: a center for integrative study.
AB - The integrative sciences, which are of great practical and conceptual interest,
investigate complex systems (cells, multicellular organisms, families,
institutions, communities, nations, etc.) at the higher levels of organization.
Academic medical centers are intrinsically integrative because of their mission
and thus are likely places for integrative study to flourish. They also possess
vast resources of the kind needed to implement integrative studies. They can thus
begin to address, from a scholarly point of view, a variety of integrative
issues: how myriad parts (molecules, cells, organisms) form stable, complex,
living wholes; the dynamics of health, illness, healing, dying, and death;
problems of integration relating to patient care, health care delivery systems,
and medical education. If academic medical centers undertake this mission they
can be springboards for scholarly advances that will potentially affect all areas
of thought. The authors describe how an integrative studies program can be
started, and share the experiences of the University of Kentucky's Office of
Integrative Studies.
PMID- 10693857
TI - Outpatient morning report: a new educational venue.
AB - Increasingly, medical educators are looking for ways to train residents and
medical students in outpatient medicine. One novel idea, outpatient morning
report, draws upon the concept of inpatient morning report and applies a similar
conference format to the outpatient setting. The authors describe outpatient
morning report and comment on its successful use in their institution.
PMID- 10693858
TI - How to improve teaching in medical colleges. 1950.
PMID- 10693859
TI - Measuring faculty effort and contributions in medical education.
AB - A national panel on medical education was appointed as a component of the AAMC's
Mission-based Management Program and charged with developing a metrics system for
measuring medical school faculty effort and contributions to a school's education
mission. The panel first defined important variables to be considered in creating
such a system: the education programs in which medical school faculty
participate; the categories of education work that may be performed in each
program (teaching, development of education products, administration and service,
and scholarship in education); and the array of specific education activities
that faculty could perform in each of these work areas. The panel based the
system on a relative value scale, since this approach does not equate faculty
performance solely to the time expended by a faculty member in pursuit of a
specific activity. Also, a four-step process to create relative value units
(RVUs) for education activities was developed. This process incorporates
quantitative and qualitative measures of faculty activity and also can measure
and value the distribution of faculty effort relative to a school's education
mission. When adapted to the education mission and culture of an individual
school, the proposed metrics system can provide critical information that will
assist the school's leadership in evaluating and rewarding faculty performance in
education and will support a mission-based management strategy in the school.
PMID- 10693861
TI - The future status of pediatric rheumatology in the United States: strategic
planning for the year 2000. American College of Rheumatology Blue Ribbon
Committee for Academic Pediatric Rheumatology.
PMID- 10693862
TI - Approaches for identifying and defining environmentally associated rheumatic
disorders.
PMID- 10693863
TI - Synovial tissue in rheumatoid arthritis is a source of osteoclast differentiation
factor.
AB - OBJECTIVE: Osteoclast differentiation factor (ODF; also known as osteoprotegerin
ligand, receptor activator of nuclear factor kappaB ligand, and tumor necrosis
factor-related activation-induced cytokine) is a recently described cytokine
known to be critical in inducing the differentiation of cells of the
monocyte/macrophage lineage into osteoclasts. The role of osteoclasts in bone
erosion in rheumatoid arthritis (RA) has been demonstrated, but the exact
mechanisms involved in the formation and activation of osteoclasts in RA are not
known. These studies address the potential role of ODF and the bone and marrow
microenvironment in the pathogenesis of osteoclast-mediated bone erosion in RA.
METHODS: Tissue sections from the bone-pannus interface at sites of bone erosion
were examined for the presence of osteoclast precursors by the colocalization of
messenger RNA (mRNA) for tartrate-resistant acid phosphatase (TRAP) and cathepsin
K in mononuclear cells. Reverse transcriptase-polymerase chain reaction (RT-PCR)
was used to identify mRNA for ODF in synovial tissues, adherent synovial
fibroblasts, and activated T lymphocytes derived from patients with RA. RESULTS:
Multinucleated cells expressing both TRAP and cathepsin K mRNA were identified in
bone resorption lacunae in areas of pannus invasion into bone in RA patients. In
addition, mononuclear cells expressing both TRAP and cathepsin K mRNA
(preosteoclasts) were identified in bone marrow in and adjacent to areas of
pannus invasion in RA erosions. ODF mRNA was detected by RT-PCR in whole synovial
tissues from patients with RA but not in normal synovial tissues. In addition,
ODF mRNA was detected in cultured adherent synovial fibroblasts and in activated
T lymphocytes derived from RA synovial tissue, which were expanded by exposure to
anti-CD3. CONCLUSION: TRAP-positive, cathepsin K-positive osteoclast precursor
cells are identified in areas of pannus invasion into bone in RA. ODF is
expressed by both synovial fibroblasts and by activated T lymphocytes derived
from synovial tissues from patients with RA. These synovial cells may contribute
directly to the expansion of osteoclast precursors and to the formation and
activation of osteoclasts at sites of bone erosion in RA.
PMID- 10693864
TI - Involvement of receptor activator of nuclear factor kappaB ligand/osteoclast
differentiation factor in osteoclastogenesis from synoviocytes in rheumatoid
arthritis.
AB - OBJECTIVE: To clarify the mechanism by which osteoclasts are formed in culture of
rheumatoid synoviocytes by exploring the involvement of receptor activator of
nuclear factor kappaB ligand (RANKL)/osteoclast differentiation factor (ODF).
METHODS: Osteoclast formation was evaluated in cocultures of rheumatoid synovial
fibroblasts and peripheral blood mononuclear cells (PBMC) in the presence of
macrophage colony stimulating factor and 1,25-dihydroxyvitamin D3 (1,25[OH]2D3)
utilizing separating membrane filters. RANKL/ODF expression was examined by
Northern blotting in synovial tissues from 5 rheumatoid arthritis (RA) patients
and tissues from patients with giant cell tumor (GCT), osteosarcoma (OS), and
osteoarthritis (OA). RANKL/ODF expression and the ability of synovial fibroblasts
to support osteoclastogenesis were investigated in coculture with PBMC in the
presence or absence of 1,25(OH)2D3, and soluble RANKL/ODF and osteoprotegerin
(OPG)/osteoclastogenesis inhibitory factor (OCIF) were measured by enzyme-linked
immunosorbent assay. The effects of OPG/OCIF on the osteoclastogenesis in the
primary culture of rheumatoid synoviocytes and the coculture system were
determined. RESULTS: Synovial fibroblasts did not induce osteoclastogenesis when
separately cocultured with PBMC. Northern blotting revealed that RANKL/ODF was
highly expressed in all tissues from RA and GCT patients, but not from OA or OS
patients. Cultured rheumatoid synovial fibroblasts efficiently induced
osteoclastogenesis in the presence of 1,25(OH)2D3, which was accompanied by up
regulated expression of RANKL/ODF and decreased production of OPG/OCIF.
Osteoclastogenesis from synoviocytes was dose-dependently inhibited by OPG/OCIF.
CONCLUSION: RANKL/ODF expressed on synovial fibroblasts is involved in rheumatoid
bone destruction by inducing osteoclastogenesis and would therefore be a good
therapeutic target.
PMID- 10693865
TI - The effects of interferon-beta treatment of synovial inflammation and expression
of metalloproteinases in patients with rheumatoid arthritis.
AB - OBJECTIVE: Interferon-beta (IFNbeta) treatment is emerging as a potentially
effective form of therapy in various immune-mediated conditions. This study
evaluated the effects of IFNbeta therapy on the cell infiltrate, cytokine
profile, and expression of metalloproteinase 1 (MMP-1) in synovial tissue from
patients with rheumatoid arthritis (RA). To further assess the mechanism of
action, in vitro experiments were conducted to determine the effects of IFNbeta
on the production of MMP-1, MMP-3, tissue inhibitor of metalloproteinases 1 (TIMP
1), and prostaglandin E2 (PGE2) by human fibroblast-like synoviocytes (FLS).
METHODS: Eleven patients were treated for 12 weeks with purified natural
fibroblast IFNbeta (Frone; Ares-Serono, Geneva, Switzerland) subcutaneously 3
times weekly with the following dosages: 6 million IU (n = 4), 12 million IU (n =
3), and 18 million IU (n = 4). Synovial biopsy specimens were obtained by needle
arthroscopy at 3 time points: directly before and at 1 month and 3 months after
initiation of treatment. Immunohistologic analysis was performed using monoclonal
antibodies specific for the following phenotypic markers and mediators of joint
inflammation and destruction: CD3, CD38, CD68, CD55, tumor necrosis factor alpha
(TNFalpha), interleukin-1beta (IL-1beta), IL-6, MMP-1, and TIMP-1. In addition,
we measured the production of MMP-1, MMP-3, TIMP-1, and PGE2 by RA FLS and dermal
fibroblasts in the presence and absence of IFNbeta. RESULTS: A statistically
significant reduction in the mean immunohistologic scores for CD3+ T cells and
the expression of MMP-1 and TIMP-1 at 1 month, CD38+ plasma cells and the
expression of IL-6 at 3 months, and the expression of IL-1beta at both 1 and 3
months was observed in synovial tissue after IFNbeta treatment. The scores for
CD68+ macrophages and TNFalpha expression also tended to decrease, but the
differences did not reach statistical significance. The in vitro experiments
revealed inhibition of MMP-1, MMP-3, and PGE2 production by RA FLS, whereas TIMP
1 production was only slightly decreased. These effects were more consistent in
RA FLS than in dermal fibroblasts. CONCLUSION: The changes in synovial tissue
after IFNbeta treatment and the in vitro data support the view that IFNbeta
therapy has immunomodulating effects on rheumatoid synovium and might help to
diminish both joint inflammation and destruction. Larger well-controlled studies
are warranted to show the efficacy of IFNbeta treatment for RA.
PMID- 10693866
TI - Increased expression of extracellular matrix metalloproteinase inducer in
rheumatoid synovium.
AB - OBJECTIVE: To investigate the expression of extracellular matrix
metalloproteinase inducer (EMMPRIN) in the synovial membrane of patients with
rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: Mouse monoclonal
antibody against human EMMPRIN was applied according to an avidin-biotin
peroxidase complex method to reveal EMMPRIN expression. Western blotting and
reverse transcriptase-polymerase chain reaction (RT-PCR) were performed to check
for the presence of EMMPRIN protein and messenger RNA (mRNA). RESULTS: EMMPRIN
immunoreactivity was more intense in RA than in OA synovial membrane (P < 0.01).
EMMPRIN staining was more widespread in RA than in OA, especially in association
with macrophage infiltrates. RT-PCR of synovial membrane samples disclosed the
presence of EMMPRIN mRNA. Nucleotide sequencing of the PCR amplification products
confirmed the identity of the amplified bands. Immunoblot analysis revealed 55-kd
glycosylated EMMPRIN bands, which were particularly prominent in RA samples.
CONCLUSION: The expression of EMMPRIN is upregulated in the rheumatoid synovial
membrane. EMMPRIN can induce local production of at least MMPs 1, 2, and 3, and
can thereby play a role in joint destruction in RA.
PMID- 10693867
TI - Synovial fluid levels of tumor necrosis factor alpha and oncostatin M correlate
with levels of markers of the degradation of crosslinked collagen and cartilage
aggrecan in rheumatoid arthritis but not in osteoarthritis.
AB - OBJECTIVE: To compare synovial fluid (SF) levels of oncostatin M (OSM), tumor
necrosis factor alpha (TNFalpha), and interleukin-6 (IL-6) in patients with
rheumatoid arthritis (RA) and osteoarthritis (OA) and to determine which
correlate best with SF levels of antigenic keratan sulfate (Ag KS), a marker of
aggrecan catabolism, and pyridinium crosslinks, markers of the degradation of
mature collagen molecules. METHODS: SF was drawn from the knee joints of patients
with RA (n = 31) or OA (n = 31). Levels of Ag KS, D-pyridinoline (D-Pyr),
pyridinoline (Pyr), OSM, TNFalpha, and IL-6 were measured by enzyme-linked
immunosorbent assay. RESULTS: RA patients had higher median SF levels of OSM,
TNFalpha, IL-6, and Pyr, but a lower median level of D-Pyr, than OA patients. In
both groups, IL-6 levels correlated positively with those of OSM and TNFalpha.
However, the correlation between levels of OSM and TNFalpha was only significant
in the RA group. Ag KS and Pyr levels correlated positively in RA but not in OA.
The correlation between TNFalpha and Ag KS was positive in RA and negative in OA.
Further, in RA, OSM and IL-6 levels correlated strongly with Pyr and Ag KS levels
but not with D-Pyr levels, while there were no strong correlations in OA for OSM
or IL-6 levels with Pyr, Ag Ks, or D-Pyr levels. CONCLUSION: This in vivo study
suggests that TNFalpha and other proinflammatory cytokines are involved in the up
regulation of the coordinated degradation of cartilage aggrecan and collagen in
RA. Further, OSM may act synergistically with other proinflammatory cytokines in
up-regulating the production of metalloproteinases by chondrocytes in rheumatoid
joints.
PMID- 10693868
TI - Therapy and prevention of arthritis by recombinant adeno-associated virus vector
with delivery of interleukin-1 receptor antagonist.
AB - OBJECTIVE: To evaluate the recombinant adeno-associated virus vector encoding
interleukin-1 receptor antagonist (rAAV-IL-1Ra) complementary DNA for its
potential in the treatment and prevention of lipopolysaccharide (LPS)-induced
arthritis. METHODS: The therapeutic effect of rAAV-IL-1Ra on arthritis was
studied by injecting knees of Sprague-Dawley rats with LPS and rAAV-IL-1Ra and
then evaluating the severity of arthritis by leukocyte counts in synovial fluid,
histologic changes of synovium, and uptake of 67Ga citrate in joint tissue. To
study the therapeutic effect on recurrent arthritis, we induced recurrent
arthritis by a second injection of LPS 80 days after primary LPS and rAAV-IL-1Ra
injections and then evaluated the severity of recurrent arthritis. To study the
prevention of arthritis, rAAV-IL-1Ra was injected into normal joints. After 100
days, LPS was used to induce arthritis, and the severity of arthritis was
evaluated. RESULTS: The production of the rAAV-IL-1Ra transgene was up-regulated
by LPS-induced joint inflammation and proved to be efficacious in the therapeutic
and preventative protocols. Not only primary but also recurrent arthritis could
be suppressed by a single injection of rAAV-IL-1Ra. We found that the transgene
expression of IL-1Ra could be reactivated by a second challenge with LPS delayed
for 80 days after rAAV administration. The therapeutic level of IL-1Ra protein
reached a mean +/- SD of 5.8+/-0.5 ng/ml in synovial fluid. In addition, the rAAV
transgene persisted within normal joints for at least 100 days and could still be
induced to express, after LPS insult, a high level of IL-1Ra (mean +/- SD 5.2+/
0.8 ng/ml) that prevented the occurrence of arthritis. CONCLUSION: This gene
therapy, by combining highly efficient and stable rAAV gene delivery, disease
regulated gene expression, and the antiinflammatory effect of IL-1Ra, provides a
valuable approach for long-term protection against, and prevention of, arthritis.
PMID- 10693869
TI - 123I-antileukoproteinase scintigraphy reveals microscopic cartilage alterations
in the contralateral knee joint of rats with "monarticular" antigen-induced
arthritis.
AB - OBJECTIVE: To assess the involvement of the contralateral knee joint in
monarticular antigen-induced arthritis (AIA) by scintigraphy with the cationic
(pI >10), 123I-labeled, serine proteinase inhibitor antileukoproteinase (123I
ALP) and to compare the scintigraphic findings with those of radiography and high
resolution ex vivo magnetic resonance imaging (MRI). METHODS: Lewis rats with
chronic AIA were examined 2.5 months following arthritis induction (injection of
500 microg of methylated bovine serum albumin/saline into the ipsilateral
[arthritic] knee joint and injection of phosphate buffered saline into the
contralateral knee joint following systemic immunization). 123I-ALP was injected
intravenously into normal rats (n = 4) or rats with AIA (n = 6). The ipsilateral
and contralateral knee joints and both ankles were examined by scintigraphy and
radiography. Joint cartilage was examined by high-resolution ex vivo MRI,
histopathology, and measurement of tissue radioactivity. RESULTS: ALP
accumulation (typically observed in normal articular cartilage) was lost in both
the ipsilateral and the contralateral knee joints, but not in the clinically
unaffected ankles of rats with AIA. In both knee joints, 123I-ALP
target:background ratios and cartilage radioactivity correlated negatively with
the loss of toluidine blue staining in cartilage, which documents the depletion
of charged matrix molecules. Findings of histopathology confirmed mild
alterations in the ipsilateral knee joint and even milder alterations in the
contralateral knee joint, while the ankles were normal. Radiography and high
resolution ex vivo MRI failed to detect abnormalities in the contralateral knee
joint. CONCLUSION: Loss of ALP accumulation appears to document proteoglycan
depletion, even in the microscopically altered cartilage of the contralateral
knee joint in AIA. These findings underscore the high sensitivity of 123I-ALP for
in vivo detection of biochemical cartilage alterations in arthritis, and
furthermore, question the use of the contralateral knee joint as a normal control
in AIA.
PMID- 10693870
TI - Cyclosporin A prevents the histologic damage of antigen arthritis without
inducing fibrosis.
AB - OBJECTIVE: To study the effects of cyclosporin A (CSA) in a model of rheumatoid
arthritis (RA) and the activation of growth factors related to pannus development
at the site of injury. METHODS: Antigen arthritis was induced in the knees of 14
New Zealand rabbits, and the animals were randomized into 2 therapeutic groups:
CSA at 10 mg/kg/day and CSA solvent. After 3 weeks of treatment, the rabbits were
killed, and synovial tissues were obtained and compared with healthy specimens
with regard to histopathologic lesions, deposition of transforming growth factor
beta (TGFbeta) and collagens, and messenger RNA expression of platelet-derived
growth factor B (PDGF-B) and TGFbeta. The effect of CSA on the expression of
TGFbeta and PDGF-B was also examined in cultured synovial cells. RESULTS: CSA
administration alleviated the histologic damage and avoided the overdeposition of
matrix elements in the injured tissue. It was also able to normalize the enhanced
expression of TGFbeta and PDGF-B observed in the untreated rabbits. Despite this
modulation found in vivo, CSA up-regulated in a dose-dependent manner the gene
expression of both trophic factors by healthy cultured synovial cells.
CONCLUSION: The present study shows that continuous administration of CSA
prevents the development of chronic synovitis in an experimental model of RA. As
reported in other cell types, CSA promoted TGFbeta transcription by synovial
cells in vitro, but failed to display a profibrogenic effect in the inflamed
environment.
PMID- 10693871
TI - Beneficial effects of tempol, a membrane-permeable radical scavenger, in a rodent
model of collagen-induced arthritis.
AB - OBJECTIVE: To investigate the effects of tempol, a membrane-permeable radical
scavenger, in rats with collagen-induced arthritis (CIA). METHODS: CIA was
induced in Lewis rats by intradermal injection of 100 microl of an emulsion of
100 microg of bovine type II collagen (CII) in complete Freund's adjuvant (FCA)
at the base of the tail. On day 21, a second injection of CII in FCA was
administered. RESULTS: Lewis rats developed an erosive arthritis of the hind paws
when immunized with CII in FCA. Macroscopic evidence of CIA first appeared as
periarticular erythema and edema in the hind paws. The incidence of CIA was 100%
by day 27 in the CII-challenged rats, and the severity of CIA progressed over a
35-day period. Radiographs revealed focal resorption of bone, with osteophyte
formation in the tibiotarsal joint, and soft tissue swelling. The histopathologic
features included erosion of the cartilage at the joint margins. Treatment of
rats with tempol (10 mg/kg/day intraperitoneally) starting at the onset of
arthritis (day 23) delayed the development of the clinical signs on days 24-35
and improved the histologic status of the knee and paw. Immunohistochemical
analysis for nitrotyrosine and poly(ADP-ribose) synthetase (PARS) revealed
positive staining in the inflamed joints of CII-treated rats. The degree of
nitrotyrosine and PARS staining was markedly reduced in tissue sections obtained
from CII-treated rats that had received tempol. Furthermore, radiographs revealed
protection against bone resorption and osteophyte formation in the joints of
tempol-treated rats. CONCLUSION: This study is the first to provide evidence that
tempol, a small molecule that permeates biologic membranes and scavenges reactive
oxygen species, attenuates the degree of chronic inflammation and tissue damage
associated with CIA in the rat.
PMID- 10693872
TI - Evidence for the expression of a second CD6 ligand by synovial fibroblasts.
AB - OBJECTIVE: CD6, a cell surface glycoprotein expressed primarily on T cells, may
function as a costimulatory molecule and may play a role in autoreactive immune
responses. Recently, a CD6 ligand termed CD166 (previously known as activated
leukocyte cell adhesion molecule [ALCAM]) has been identified and shown to be
expressed on activated T cells, B cells, thymic epithelium, keratinocytes, and in
rheumatoid arthritis synovial tissue. However, the results of functional studies
have suggested the existence of a second CD6 ligand. The present study was
undertaken to seek evidence for a second CD6 ligand on cultured synovial
fibroblasts. METHODS: Flow cytometric and biochemical techniques were applied,
using anti-CD166 monoclonal antibody (mAb) and a recombinant CD6 fusion protein,
to determine whether cultured synovial fibroblasts and other cell types expressed
a non-ALCAM CD6 ligand. RESULTS: CD14- fibroblastic synoviocytes showed greater
binding of a recombinant CD6 fusion protein than of anti-ALCAM mAb. With
interferon-gamma treatment of synovial fibroblasts, binding of both reagents
increased, but this was more marked for binding of CD6 fusion protein. Exposure
of synovial fibroblasts to other cytokines or to the superantigen staphylococcal
enterotoxin A also regulated binding of CD6 fusion protein and anti-ALCAM mAb in
a discordant manner. Immunoprecipitation of proteins from membrane extracts of
synovial fibroblasts with a CD6-Ig fusion protein revealed a novel 130-kd band
distinct from CD166; an identical molecule was also precipitated from membranes
of HBL-100 tumor cells. CONCLUSION: Taken together with previous data regarding
CD6 and CD166 function, the present findings strongly suggest the existence of a
second CD6 ligand distinct from CD166, which can be expressed by synovial
fibroblasts as well as other cells.
PMID- 10693873
TI - Decreased expression of interleukin-1alpha, interleukin-1beta, and cell adhesion
molecules in muscle tissue following corticosteroid treatment in patients with
polymyositis and dermatomyositis.
AB - OBJECTIVE: To study the effects of immunosuppressive therapy, in particular,
corticosteroids, on morphologic signs of inflammation and expression of
cytokines, adhesion molecules, and class I major histocompatibility complex (MHC)
antigen in muscle tissue from patients with polymyositis (PM) and dermatomyositis
(DM) and to correlate the molecular changes with changes in muscle function.
METHODS: Seven patients with PM and 4 patients with DM underwent muscle biopsy
before and after 3-6 months of therapy. Ten of the 11 patients were initially
treated with prednisolone 30-60 mg/day. The phenotypes of infiltrating
inflammatory cells and the expression of interleukin-1alpha (IL-1alpha) and IL
1beta, adhesion molecules, and class I MHC antigen were studied by
immunochemistry. Computerized image analysis was used for quantitation of
staining. Muscle function was assessed with a muscle function index score.
RESULTS: Pronounced improvement of muscle function during the treatment period
was noted in 8 of the 11 patients. The changes in muscle function coincided with
an almost complete disappearance of inflammatory cells, including CD3+ T cells,
in the patients with clinical improvement. These patients also exhibited
decreased expression of IL-1alpha, IL-1beta, intercellular adhesion molecule 1
(ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), leukocyte function
associated antigen 1alpha, and very late activation antigen 4alpha. Of note,
there was persistent expression of IL-1alpha, ICAM-1, and VCAM-1 in capillaries
and of class I MHC antigens on muscle fibers in several of the patients who,
after corticosteroid treatment, still had muscle weakness despite the
disappearance of inflammatory infiltrates. CONCLUSION: Changes in the muscle
expression of key molecules in the inflammatory process, such as IL-1alpha and IL
1beta, ICAM-1 and class I MHC antigens, showed a consistent but not complete
concordance with changes in and status of muscle function in patients with
myositis who received the current standard treatment for the disease. These data
indicate that it is possible to further evaluate various therapies for myositis
using molecular analysis of muscle biopsy specimens obtained on repeated
occasions. In addition, the data demonstrate a dissociation between muscle
function and degree of inflammatory infiltration in the affected muscles and
suggest that the functional defects are more related to the expression of
molecules such as IL-1alpha in muscle capillaries than to the mere presence of
inflammatory cells in the affected muscles.
PMID- 10693874
TI - Identification of intervals on chromosomes 1, 3, and 13 linked to the development
of lupus in BXSB mice.
AB - OBJECTIVE: To identify intervals containing systemic lupus erythematosus (SLE)
susceptibility alleles in the BXSB strain of mice. METHODS: We analyzed 286 (B10
x [B10 x BXSB]F1) backcross mice for a range of phenotypic traits associated with
the development of SLE in BXSB mice. The mice were genotyped using 93
microsatellite markers, and the linkage of these markers to disease was studied
by extreme-phenotype and quantitative trait locus analysis. RESULTS: The disease
phenotype in these backcross mice was less severe than that in BXSB mice.
However, antinuclear antibody production was increased compared with the parental
strain. We identified 4 areas of genetic linkage to disease on chromosome 1 (Bxs1
4), 1 on chromosome 3 (Bxs5), and another interval on chromosome 13 which were
associated with various aspects of the phenotype. Bxs4 and Bxs5 are located in
regions not previously linked to disease in other models of SLE. CONCLUSION: SLE
in the BXSB mouse model has a complex genetic basis and involves at least 5
distinct intervals located on chromosomes 1 and 3. There is evidence that
different intervals affect particular aspects of the SLE phenotype.
PMID- 10693875
TI - The features of arthritis induced by CpG motifs in bacterial DNA.
AB - OBJECTIVE: To investigate the features of arthritis induced by bacterial DNA that
contain CpG motifs. METHODS: Bacterial DNA originating from Escherichia coli and
Staphylococcus aureus or synthetic oligonucleotides containing CpG motifs were
injected directly into knee joints of mice. Histopathologic joint damage,
antibody levels, cytokine levels, and synovial messenger RNA (mRNA) expression of
cytokines and chemokines were assessed. RESULTS: Histopathologic signs of
arthritis were evident within 2 hours and lasted for at least 3 weeks.
Nonmethylated CpG motifs were responsible for the induction of arthritis since
oligonucleotides containing these motifs triggered arthritis, whereas methylation
of these nucleotides abrogated the inflammatory response. Arthritis was
characterized by an influx of monocytic, Mac-1+ cells and by a scarcity of T
lymphocytes. The disease was characterized locally by mRNA expression of
macrophage-derived cytokines (tumor necrosis factor alpha, interleukin-12 [IL
12], IL-1beta) and chemokines (monocyte chemoattractant protein 1, RANTES) in
arthritic joints. Systemically, the arthritis was characterized by increased
levels of circulating IL-6 and immunoglobulins. CONCLUSION: These findings
demonstrate that bacterial DNA that contain nonmethylated CpG motifs induces
arthritis, suggesting an important pathogenic role for bacterial DNA in septic
arthritis.
PMID- 10693876
TI - Detection of viral ribonucleic acid and histologic analysis of inflamed synovium
in Ross River virus infection.
AB - OBJECTIVE: To document the histology of Ross River virus (RRV) arthritis and to
examine inflamed synovium for viral RNA. METHODS: Biopsy tissue from the inflamed
knees of 12 patients with RRV infection was studied using conventional and
immunostaining techniques. Reverse transcriptase-polymerase chain reaction
technology was used to probe for the presence of viral RNA in the synovial biopsy
samples and in serum. RESULTS: Hyperplasia of the synovial lining layer, vascular
proliferation, and mononuclear cell infiltration were the main histologic
changes. RRV RNA was found in knee biopsy tissue that was obtained from 2
patients at 5 weeks after the onset of symptoms. CONCLUSION: RRV RNA was
identified in inflamed synovium more than a month after symptoms began.
Inflammation was apparent in the absence of detectable virus in the majority of
patients.
PMID- 10693877
TI - Comparison of the effect of rofecoxib (a cyclooxygenase 2 inhibitor), ibuprofen,
and placebo on the gastroduodenal mucosa of patients with osteoarthritis: a
randomized, double-blind, placebo-controlled trial. The Rofecoxib Osteoarthritis
Endoscopy Multinational Study Group.
AB - OBJECTIVE: This randomized, double-blind study tested the hypothesis that
rofecoxib, a drug that specifically inhibits cyclooxygenase 2, would cause fewer
gastroduodenal ulcers than ibuprofen (in a multicenter trial), and its side
effects would be equivalent to those of placebo (in a prespecified analysis
combining the results with another trial of identical design). METHODS: Seven
hundred seventy-five patients with osteoarthritis were randomized to receive
rofecoxib at a dosage of 25 mg or 50 mg once daily, ibuprofen 800 mg 3 times
daily, or placebo. Gastroduodenal ulceration was assessed by endoscopy at 6, 12,
and (for active treatment) 24 weeks. The primary and secondary end points were
the incidence of gastroduodenal ulcers at 12 and 24 weeks, respectively. RESULTS:
Ulcers were significantly less common (P < 0.001) following treatment with
rofecoxib (25 mg or 50 mg) than with ibuprofen after 12 weeks (5.3% and 8.8%
versus 29.2%, respectively) or 24 weeks (9.9% and 12.4% versus 46.8%,
respectively). In the combined analysis, the 12-week ulcer incidence with 25 mg
rofecoxib (4.7%) and with placebo (7.3%) satisfied prespecified criteria for
equivalence. CONCLUSION: At 2-4 times the therapeutically effective dose,
rofecoxib caused fewer endoscopically detected ulcers than did ibuprofen.
Rofecoxib at a dose of 25 mg (the highest dose recommended for osteoarthritis)
satisfied prespecified criteria for equivalence to placebo.
PMID- 10693878
TI - Preference for nonsteroidal antiinflammatory drugs over acetaminophen by
rheumatic disease patients: a survey of 1,799 patients with osteoarthritis,
rheumatoid arthritis, and fibromyalgia.
AB - OBJECTIVE: Because there is controversy regarding the efficacy of acetaminophen
in rheumatic diseases and because apparently safer nonsteroidal antiinflammatory
drugs (NSAIDs) are being produced, we surveyed rheumatic disease patients about
their preferences for these agents to determine the degree to which one type of
therapeutic agent is preferred over the other. METHODS: In 1998, we surveyed by
mailed questionnaire 1,799 patients with osteoarthritis (OA), rheumatoid
arthritis, or fibromyalgia who were participating in a long-term outcome study.
Patients who had taken acetaminophen rated the effectiveness of acetaminophen,
compared its effectiveness with that of NSAIDs, and then rated their overall
satisfaction with acetaminophen compared with NSAIDs when both effectiveness and
side effects were considered. RESULTS: Two-thirds of study participants had taken
acetaminophen. About 37% of patients who had taken acetaminophen found it to be
moderately or very effective and about 63% indicated that it was not effective or
was only slightly effective. One-fourth of the patients found acetaminophen and
NSAIDs to be equally effective, but >60% found acetaminophen to be much less
effective or somewhat less effective. About 12% preferred acetaminophen to
NSAIDs. When both effectiveness and side effects were considered together, 25% of
the patients had no preference, 60% preferred NSAIDs, and 14% preferred
acetaminophen. CONCLUSION: There was a considerable and statistically significant
preference for NSAIDs compared with acetaminophen among the 3 groups of rheumatic
disease patients. Although this preference decreased slightly with age and was
less pronounced in OA patients, the preference was noted among all categories of
patients and was not altered by disease severity. If safety and cost are not
issues, there would hardly ever be a reason to recommend acetaminophen over
NSAIDs, since patients generally preferred NSAIDs and fewer than 14% preferred
acetaminophen. If safety and costs are issues, then the recommendation of the
American College Rheumatology that acetaminophen be tried first seems correct,
since 38.2% found acetaminophen to be as effective or more effective than NSAIDs.
PMID- 10693879
TI - Scores for functional disability in patients with rheumatoid arthritis are
correlated at higher levels with pain scores than with radiographic scores.
AB - OBJECTIVE: To analyze correlations of functional disability scores with other
measures of clinical status, in particular, Larsen radiographic scores and pain
scores, in patients with rheumatoid arthritis (RA). METHODS: The functional
capacity of 141 patients with RA (102 women, 39 men; median age 57 years; median
disease duration 11.8 years; 83% rheumatoid factor positive) was assessed
according to the Stanford Health Assessment Questionnaire (HAQ). Other variables
studied included Larsen scores for radiographic damage of the small joints of the
hands, wrists, and feet, pain scores by visual analog scale (VAS), Disease
Activity Scores, general health scores by VAS, and Beck Depression Inventory
(BDI) scores. RESULTS: The Spearman correlation coefficient comparing HAQ and
Larsen scores was 0.277 (P = 0.001) and between HAQ and pain scores 0.652 (P <
0.001). In regression analysis, pain scores explained 41.4% of the variation in
HAQ scores, normalized Larsen scores explained 7.3%, and BDI scores explained
5.5%; other variables were not significant in the model. CONCLUSION: Functional
capacity scores of patients with RA are correlated at higher levels with pain
scores than with radiographic scores of small joints.
PMID- 10693880
TI - Recipients of hip replacement for arthritis are less likely to be Hispanic,
independent of access to health care and socioeconomic status.
AB - OBJECTIVE: To compare the proportion of Hispanics among recipients of hip
replacements for primary articular disorders, recipients of knee replacements for
the same reason, and persons hospitalized for other reasons. METHODS: Twelve of
the 17 accredited hospitals in Bexar County, Texas, in which hip or knee
replacement surgery is performed permitted us to review their medical records.
From 1993 through 1995, 3,100 elective, non-fracture-related, hip or knee
replacements were performed. These individuals were matched by age, sex,
hospital, and month of admission with 4,604 persons hospitalized for other
reasons. Age, sex, ethnic background, type of medical insurance, median household
income by zip code of residence, joint replaced, and surgical diagnosis were
abstracted from the medical records. The validity of variables abstracted from
the medical records was tested by comparison with self-report data in 115
patients interviewed prior to elective hip or knee replacement surgery. RESULTS:
During the study period, 2,275 subjects had a total knee replacement and 825 had
a total hip replacement. Recipients of hip replacements were significantly less
likely to be Hispanic than were recipients of knee replacements (19.5% versus
29.9%; odds ratio [OR] 0.57, 95% confidence interval [95% CI] 0.46-0.71; P < or =
0.001) or persons hospitalized for other reasons (29.4% Hispanic; OR 0.67, 95% CI
0.55-0.81). The under-representation of Hispanics was more pronounced among
persons undergoing hip replacement for osteoarthritis compared with recipients of
knee replacements for the same disease (OR 0.48, 95% CI 0.37-0.62). This pattern
persisted after adjusting for age, sex, type of medical insurance, and median
household income by the zip code of residence. Concordance between medical
records and self-report data on ethnic background was high (kappa = 0.93).
CONCLUSION: Recipients of hip replacement are less likely to be Hispanic than are
other hospitalized persons with a similar level of access to care. The reasons
for this under-representation probably involve factors in addition to lack of
access to health care and low socioeconomic status. Further research is needed to
understand the nature of such factors.
PMID- 10693881
TI - Association of mild acetabular dysplasia with an increased risk of incident hip
osteoarthritis in elderly white women: the study of osteoporotic fractures.
AB - OBJECTIVE: To determine if acetabular dysplasia increases the risk of incident
hip osteoarthritis (OA) among elderly white women. METHODS: Baseline and followup
anteroposterior pelvic radiographs were obtained a mean of 8 years apart, and
read for individual radiographic features (IRFs) of hip OA; summary grades (0-4)
were then assigned based on the IRFs present. Acetabular dysplasia was defined by
the results of measurements of the acetabular depth (<9 mm) or the center-edge
angle (<30 degrees). Logistic regression analyses were performed to determine the
association between acetabular dysplasia and incident hip OA, and all analyses
were adjusted for age, current weight, body mass index, affected side, and
investigational site. RESULTS: The odds ratios for the association of abnormal
center-edge angle and acetabular dysplasia with incident hip OA were 3.3 (95%
confidence interval 1.1-10.1) and 2.8 (95% confidence interval 1.0-7.9),
respectively. CONCLUSION: Acetabular dysplasia, defined by a decrease in the
center-edge angle, is associated with a modestly increased risk of incident hip
OA in elderly white women.
PMID- 10693882
TI - Drug-associated antineutrophil cytoplasmic antibody-positive vasculitis:
prevalence among patients with high titers of antimyeloperoxidase antibodies.
AB - OBJECTIVE: The triggers that induce antineutrophil cytoplasmic antibody (ANCA)
positive vasculitis (APV) are largely unknown. However, there have been reports
suggesting that hydralazine, propylthiouracil, and several other drugs may cause
some cases of APV, and the majority of these cases have been associated with
antimyeloperoxidase (anti-MPO) ANCA. Our experience led us to hypothesize that
cases of high titers of anti-MPO antibodies are often drug-associated. METHODS:
In this study, we determined the prevalence of exposure to hydralazine,
propylthiouracil, and other drugs previously implicated in APV among 30 patients
with vasculitis and the highest titers of anti-MPO antibodies newly detected in
our laboratory between 1994 and 1998. The clinical, histologic, and other
serologic features of these 30 patients were also examined. RESULTS: The 30 study
patients accounted for 12% of the 250 new patients with APV and anti-MPO who were
tested during the study period. All 30 study subjects had anti-MPO titers that
were more than 12 times the median titer of the 250 patients. Ten (33%) of the 30
patients had been exposed to hydralazine and 3 (10%) had been exposed to
propylthiouracil. An additional 5 patients (17%) had been exposed to 1 of the
other previously reported candidate drugs: 2 to penicillamine, 2 to allopurinol,
and 1 to sulfasalazine. One of the patients exposed to hydralazine had also been
exposed to allopurinol. In all cases, the clinical and histologic findings were
typical of APV. There was a strong association between the presence of
antielastase and/ or antilactoferrin antibodies and exposure to candidate drugs.
CONCLUSION: These data suggest that a sizable proportion of cases of APV with
high titers of anti-MPO antibodies are drug-associated, especially following
exposure to hydralazine or propylthiouracil. We recommend that the use of these
drugs should be sought in cases of anti-MPO-positive vasculitis, particularly
among patients with high titers of these antibodies.
PMID- 10693883
TI - Epidemiology of systemic vasculitis: a ten-year study in the United Kingdom.
AB - OBJECTIVE: To describe the epidemiology of the primary systemic vasculitides
(PSV; Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis,
polyarteritis nodosa) in a well-defined population over a 10-year period.
METHODS: An inception cohort of patients from the Norwich Health Authority (NHA)
who were >15 years of age and had PSV first diagnosed between January 1, 1988 and
December 31, 1997 was collected. Incidence rates were adjusted for age and sex to
the 1992 population. The prevalence of PSV in this cohort was estimated on
December 31, 1997. Patients were classified according to the American College of
Rheumatology 1990 vasculitis criteria and the Chapel Hill Consensus definitions.
RESULTS: Eighty-two NHA residents fulfilled the inclusion criteria. There were 47
men and 35 women, with a mean age of 62.9 years (median 65.0 years). The overall
annual incidence of PSV among NHA residents was 19.8/million (95% confidence
interval [95% CI] 15.8-24.6). The point prevalence on December 31, 1997 was
144.5/million (95% CI 110.4-185.3). PSV was more common in males (23.5/million;
95% CI 17.3-31.3) than females (16.4/million; 95% CI 11.4-22.8). The age- and sex
specific incidence showed a clear increase with age, with an overall peak in the
65-74 year age group (60.1/million). CONCLUSION: In our study population, the
annual incidence of PSV is slowly increasing with time and the incidence is
greatest in the elderly.
PMID- 10693884
TI - The lupus erythematosus cell phenomenon: comparative analysis of antichromatin
antibody specificity in lupus erythematosus cell-positive and -negative sera.
AB - OBJECTIVE: To compare and investigate antihistone and antichromatin antibody
responses as well as clinical variables in patients with systemic lupus
erythematosus (SLE) who were either positive (LEC+) or negative (LEC-) for the
lupus erythematosus (LE) cell phenomenon. METHODS: The binding properties of LEC+
and LEC- SLE sera to chromatin-associated nuclear antigens (histones H1, H2A,
H2B, H3, H4; complexes of H2A-H2B, [H2A-H2B]-DNA, H1-DNA; total and H1-stripped
chromatin; native and denatured DNA) were investigated. In addition, sera from
patients with drug-induced lupus (by procainamide, hydralazine, or quinidine), as
well as from patients with rheumatoid arthritis and osteoarthritis, were
assessed. Enzyme-linked immunosorbent assay was used to detect specific antibody
binding. RESULTS: Mirroring the important role of histone H1 in the formation of
LE cells, anti-histone H1 reactivity was 8-fold higher in LEC+ sera than in LEC-
sera. In addition, reactivities to most of the other antigens tested, i.e., other
histones and histone-DNA complexes as well as chromatin and DNA, were
significantly higher in LEC+ sera than in LEC- sera. All but 1 serum sample from
the patients with drug-induced lupus were negative for LE cell formation as well
as for anti-histone H1 reactivity, but displayed high antibody reactivities to
histone-DNA complexes, including chromatin. Sera from patients with rheumatoid
arthritis and osteoarthritis did not show significant binding to these antigens.
When comparing the clinical features of LEC+ and LEC- SLE patients, severe organ
involvement, including nephritis and central nervous system involvement, was
common in the LEC+ group, but rare in the LEC- group. CONCLUSION: A positive LE
cell phenomenon not only correlated with the presence of high anti-histone H1
antibody levels in SLE, but also indicated serologically and clinically active
disease with major organ involvement.
PMID- 10693885
TI - Cross-reactivity of antiidiotypic antibodies with DNA in systemic lupus
erythematosus.
AB - OBJECTIVE: To assess the functional relationship between antibodies reactive with
DNA and antibodies reactive with the idiotypes (idiopeptides) of anti-DNA
antibodies that are associated with systemic lupus erythematosus (SLE) in mice.
METHODS: Antiidiotypic antibodies that appeared spontaneously in lupus mice, and
others that were induced by immunization of normal, non-lupus mice, were analyzed
for their reactivity by a range of direct binding, competition enzyme-linked
immunosorbent assay (ELISA), and surface plasmon resonance (SPR) methods. Their
reactions were assessed against synthetic peptides representing sequences of the
V(H) region of anti-DNA monoclonal antibody (mAb) V-88, against the native mAb
itself, and against mammalian DNA. RESULTS: In lupus mice, only sera with the
highest reactivity against double-stranded DNA (dsDNA) also reacted with
idiopeptides in ELISA, and this showed a strong statistical correlation. However,
there was no significant relationship between antiidiotypic antibodies and anti
single-stranded DNA antibodies. Immunization of (BALB/c x NZW)F1 mice with
idiopeptides p64 (V(H) residues 64-80) or p92 (V(H) residues 92-105) induced
antibodies that reacted not only against the respective peptides, but also
against the native parent anti-DNA mAb V-88. Furthermore, the immune
antiidiopeptide antibodies cross-reacted with dsDNA. Competition SPR experiments
with the BIAcore system supported this observation. The binding reaction of V(H)
peptide p64 (representing the CDR-H2/FR-H3 region of V-88) with antiidiopeptide
antibodies was inhibited by dsDNA. CONCLUSION: This study identified a unique set
of autoantibodies in SLE. They react with both autoantibody idiotopes and with
dsDNA, thus having a dual specificity for 2 autoantigens. Because these
antiidiotope antibodies arise naturally during the development of lupus disease,
and because they bind also to dsDNA, this provides a mechanism whereby the
production of anti-dsDNA antibodies is stimulated. These idiotopes on
autoantibodies in lupus act as natural mimotopes for inducing anti-dsDNA
antibodies, which, due to their dual specificity, may significantly contribute to
the pathology of nephritis in SLE.
PMID- 10693886
TI - Validation of the Sapporo criteria for antiphospholipid syndrome.
AB - OBJECTIVE: To test the Sapporo criteria for the classification of the
antiphospholipid syndrome (APS). METHODS: We classified 243 consecutive patients
who had clinical diagnoses of primary APS (n = 49), secondary APS (n = 26),
systemic lupus erythematosus (SLE) without clinical APS (n = 131), and lupus-like
disease without clinical APS (n = 37). RESULTS: Sensitivity, specificity,
positive predictive value, and negative predictive value were 0.71, 0.98, 0.95,
and 0.88, respectively. False-negative findings were the result of patients being
classified on the basis of minor criteria that were not included in the Sapporo
criteria, such as livedo reticularis, thrombocytopenia, low-titer IgG or IgM
anticardiolipin antibody, IgA anticardiolipin antibody, and anti-beta2
glycoprotein I antibody. Some patients with false-negative results were true
seronegative cases. CONCLUSION: The Sapporo criteria for APS compare favorably
with the American College of Rheumatology criteria for SLE and are usable for
clinical studies.
PMID- 10693887
TI - Systemic sclerosis sine scleroderma: demographic, clinical, and serologic
features and survival in forty-eight patients.
AB - OBJECTIVE: To describe the demographic, clinical, and laboratory features and
natural history of patients with systemic sclerosis sine scleroderma (ssSSc), and
to compare them with those of patients with SSc and limited cutaneous involvement
(IcSSc). METHODS: The University of Pittsburgh Scleroderma Databank served as the
data source. Patients were divided into those who had no skin thickening (ssSSc)
and those who had skin thickening only distal to elbows or knees and/or of the
face (IcSSc) during their disease course. These two groups were compared with
regard to demographic characteristics, clinical, laboratory, and serologic
features, and survival rates. Chi-square and Student's t-test analyses were
performed, and Fisher's exact test was used as appropriate. RESULTS: Of 555
consecutive patients without diffuse cutaneous SSc, 48 (9%) had ssSSc and 507
(91%) had IcSSc. The ssSSc patients had a mean total disease duration of 18.6
years (15.1 years before study entry and 3.5 years of followup after study
entry), and had not developed IcSSc or another connective tissue disease. Other
than the absence of skin thickening, the ssSSc group had no significant
differences in individual internal organ involvements, laboratory features, serum
autoantibody type, or survival rate compared with patients with IcSSc. Within the
category of lung involvement, patients with ssSSc had a significantly greater
frequency of dyspnea with mild exertion or at rest, and a tendency toward reduced
carbon monoxide diffusing capacity (<70% of predicted normal) and primary
pulmonary arterial hypertension. Patients with IcSSc had significantly more
frequent individual manifestations of digital pitting scars, digital-tip ulcers,
telangiectasia, and calcinosis than those with ssSSc, in part related to
increased time of observation. Puffy fingers and finger joint contractures were
detected significantly more often in IcSSc patients. CONCLUSION: Systemic
sclerosis sine scleroderma should be included in the spectrum of SSc with limited
cutaneous involvement and should not be considered a distinct or separate
disorder.
PMID- 10693888
TI - Association of transforming growth factor beta1 genotype with spinal
osteophytosis in Japanese women.
AB - OBJECTIVE: To examine the possible relationship between a T-->C polymorphism at
nucleotide position 29 of the transforming growth factor beta1 (TGFbeta1) gene
and genetic susceptibility to radiographic spinal osteophytosis. METHODS: A total
of 540 postmenopausal Japanese women were subjected to radiography of the spine
and determination of bone mineral density (BMD) for the lumbar spine and total
body. Changes in lumbar intervertebral discs were examined in 67 individuals with
either osteoporosis or spinal osteophytosis by magnetic resonance imaging (MRI).
TGFbeta1 genotype was determined with an allele-specific polymerase chain
reaction assay. The serum concentration of TGFbeta1 was measured in 29 control
subjects and in 36 patients with spinal osteophytosis. RESULTS: Among all study
subjects, the prevalence of radiographic spinal osteophytosis in individuals with
the CC genotype was greater than that in those with the TC or TT genotype.
Logistic regression analysis, adjusted for age, height, body weight, time since
menopause, smoking status, body fat, lean mass, and either lumbar spine or total
body BMD, demonstrated that the frequency of the C allele in subjects with spinal
osteophytosis was significantly greater than that in those without this
condition. Comparison among control, osteoporosis, and spinal osteophytosis
groups also revealed that the C allele was more prevalent in subjects with
osteophytosis than in controls, even after adjustment for BMD. In contrast, as
previously shown, the frequency of the C allele was lower in osteoporosis
patients than in controls. The intervertebral disc area and the ratio of disc
area to vertebral body area, as determined by MRI, were also lowest in subjects
with the CC genotype. The serum concentration of TGFbeta1 increased with the
number of C alleles in both controls and patients with spinal osteophytosis.
CONCLUSION: The T29-->C polymorphism of the TGFbeta1 gene exhibited inverse
patterns of association with genetic susceptibility to spinal osteophytosis and
with osteoporosis. Although radiographic evaluation of osteophytes might not
reflect the actual disease severity, the C allele, which protects against
osteoporosis, may be a risk factor for genetic susceptibility to spinal
osteophytosis.
PMID- 10693889
TI - Rheumatoid arthritis exacerbation caused by exogenous interleukin-12.
AB - Interleukin-12 (IL-12) is a pleiotropic cytokine with proinflammatory,
immunoregulatory, antitumor, and antimetastatic properties. It plays a crucial
role in the development of the Th1 response and subsequent interferon-gamma
production and enhancement of cell-mediated cytotoxicity. Recently, IL-12 has
been used as an experimental therapy for cancer. Given the multiple
immunomodulatory properties of IL-12, there are potential concerns associated
with its clinical use. Of special interest are the possible side effects of IL-12
therapy in patients with autoimmune diseases, especially those that are T cell
mediated, such as rheumatoid arthritis (RA). We present a case of severe RA
exacerbation caused by treatment with IL-12 for metastatic cervical cancer. This
is the first reported case of RA flare caused by exogenous IL-12.
PMID- 10693890
TI - The changing face of rheumatoid arthritis therapy: results of serial surveys.
PMID- 10693891
TI - Diurnal rhythm of salivary cortisol levels in patients with recent-onset
rheumatoid arthritis.
PMID- 10693892
TI - Clinical images: Wegener's granulomatosis presenting as Pancoast tumor.
PMID- 10693893
TI - Exacerbation of systemic lupus erythematosus after hepatitis B vaccination:
comment on the article by Battafarano et al and the letter by Senecal et al.
PMID- 10693894
TI - Absence of p53 mutation in Japanese patients with rheumatoid arthritis: comment
on the article by Han et al.
PMID- 10693895
TI - Severity of rheumatoid arthritis in Portuguese patients: comment on the article
by Drosos et al and on the letter by Ronda et al.
PMID- 10693896
TI - Clinical images: Leg pain and clubbing.
PMID- 10693897
TI - Validation of the United States' version of the World Health Organization Quality
of Life (WHOQOL) instrument.
AB - In 1991, the World Health Organization initiated a project to simultaneously
develop a quality of life (QOL) instrument in 15 countries: The World Health
Organization Quality of Life (WHOQOL) instrument. This was intended as a generic
QOL tool for use with patients across varying disease types, severities of
illness, and cultural subgroups. The objective of the current study was to
evaluate the WHOQOL-100 in the U.S., one of the original 15 participating
countries. The WHOQOL is a 100-item self-report instrument consisting of 24
subscales within six domains: Physical, Psychological, Independence, Social,
Environment, and Spiritual. Four additional items pertain to overall QOL/health.
We tested the WHOQOL-100 (U.S. version) in a sample of 443 adults (n = 251
chronically ill, n = 128 healthy, and n = 64 childbearing) in the U.S. to test
its reliability (internal consistency, test-retest), construct validity
(convergent, discriminant), responsiveness, and factor structure. The WHOQOL-100
(U.S. version) has acceptable internal consistency (alpha range: 0.82-0.95 across
domains) and reproducibility (ICC range: 0.83-0.96 at 2-week retest interval). It
is responsive to change in clinical conditions, as evidenced by predicted score
change (effect size) in women after childbirth. Construct validity was
demonstrated by (1) its correlation with the Short Form-36 and Subjective Quality
of Life Profile, and (2) its ability to discriminate between the diverse samples
in this study. The conceptual structure was confirmed exactly with the exception
of four facets that did not correlate most highly with the domains to which they
were originally assigned, but these differences were minor. The WHOQOL
measurement system is suitable for evaluating the QOL of adults in the U.S. The
psychometric properties will be continually evaluated as more data become
available in the U.S.
PMID- 10693898
TI - Ready, set, stop: reflections on assessing quality of life and the WHOQOL-100
(U.S. version). World Health Organization Quality of Life.
PMID- 10693899
TI - Quality of life measurement: will we ever be satisfied?
PMID- 10693900
TI - Ready, set, stop, and standing.
PMID- 10693901
TI - Shoulder disability questionnaire design and responsiveness of a functional
status measure.
AB - The Shoulder Disability Questionnaire (SDQ) is a measure covering 16 items
designed to evaluate functional status limitation in patients with shoulder
disorders. The responsiveness of the SDQ was evaluated for 180 patients with soft
tissue shoulder disorders, without underlying systemic disorders. These patients
participated in a randomized placebo-controlled trial, in which ultrasound and
electrotherapy appeared to be ineffective as adjuvants to standardized exercise
therapy. At baseline and at 6-week follow-up, patients completed the SDQ and
rated severity of shoulder pain and their chief complaint, while a research
physiotherapist rated severity of symptoms and restriction of mobility. At the 6
week follow-up, patients also rated overall change since baseline. According to
the calibrated responsiveness ratio (CRR) and the area under the receiver
operator characteristic curve (AUC) the SDQ discriminates accurately between self
rated clinically stable and improved subjects. The presented results suggest that
the SDQ is as responsive as the compared outcome measures, and therefore is ready
for use in clinical trials.
PMID- 10693902
TI - Comparing treatment valuations between and within subjects in clinical trials:
does it make a difference?
AB - Valuations may be sensitive to biases, especially if elicited alongside
randomized clinical trials. We investigated the construction of valuations
assigned by women who entered a randomized clinical trial and were allocated to
in-hospital or domiciliary monitoring. Women assigned valuations (0-10 visual
analogue scale) to the strategy they had been allocated to and to the alternative
strategy. Valuations were expressed as a between-subject difference (assigned by
the women allocated to the respective strategies) and as within-subject
differences (assigned by all women). Domiciliary monitoring was valued higher by
the women allocated to that strategy (P = 0.10). In-hospital monitoring was
valued higher by the women allocated to that strategy (P = 0.02). The average
within-subject differences differed by allocated strategy (P<0.01). The within
subject valuation differences showed large variability between and within groups.
An overrepresentation of women favoring domiciliary monitoring and asymmetric
treatment experience inflated the average within-subject difference in the
domiciliary group but deflated that difference in the in-hospital group. Neither
the average between-subject difference nor the average within-subject differences
are free of bias. Other study designs probably cannot prevent bias. Comparing
within-subject and between-subject differences is instructive.
PMID- 10693903
TI - Lessons learned from enrollment in the BEST study--a multicenter, randomized
trial of group psychosocial support in metastatic breast cancer.
AB - The BEST study, a multicenter randomized trial of group psychosocial support in
metastatic breast cancer, had several unusual features that may have influenced
recruitment, notably the group nature of the intervention and the need for close
collaboration between medical and psychosocial investigators. The recruitment
process was examined in light of these features. Establishment of study centers
was facilitated by involvement of experienced medical investigators who had
successfully collaborated in previous research projects. Systematic evaluation of
potential subjects or direct recruitment by psychosocial investigators optimized
recruitment; however, the group nature of the intervention prolonged recruitment.
Overall, 652 women were approached and 237 (43.3% of those medically eligible)
randomized. Using population-based estimates, 24.3% of women with metastatic
breast cancer were assessed for the study and 8.7% randomized. A randomization
ratio of 2:1 was required to form and maintain groups. Competing clinical trials
were the greatest barrier to recruitment. Five lessons were learned during
recruitment for this trial: (1) multicenter randomized trials of psychosocial
interventions are feasible, even in very ill patients, (2) the use of a group
intervention effectively increased the required sample size by 50%, (3)
similarity of randomization rates suggests that generalizability of study results
will probably be comparable to that of other randomized cancer trials, (4)
multidisciplinary collaborations and involvement of experienced researchers
facilitated enrollment, and (5) most challenges encountered in recruitment were
similar to those seen in all clinical trials.
PMID- 10693904
TI - Analytic strategies for recurrent events in epidemiologic studies: background and
application to hospitalization risk in the elderly.
AB - Due to the intraindividual dependence, specific analytic strategies are needed to
assess risk factors for recurrent events. Although well established in the
biostatistics literature, applications of these techniques are almost nonexistent
in the field of epidemiology. The authors applied four different regression
approaches for recurrent events (logistic, Poisson, and two different Cox
proportional hazards regressions) to derive rate ratios of hospitalizations for
various prognostic factors in a cohort of 2424 frail elderly. Over a median
follow-up of 670 days, 3299 hospitalizations were observed in 1564 persons.
Estimated rate ratios were similar in all four approaches and virtually identical
in three. With all methods, confidence intervals of the rate ratios were
considerably wider than with naive Poisson regression neglecting intraindividual
dependence of events. Appropriate analysis of recurrent events is feasible with
minor modifications of multivariable models familiar to epidemiologists and
should no longer be neglected in epidemiologic research. In our setting, Poisson
regression was the most convenient approach.
PMID- 10693905
TI - Publications on diagnostic test evaluation in family medicine journals: an
optimal search strategy.
AB - Search strategies for articles reporting on diagnostic test evaluations have been
subjected to less research than those in the domain of clinical trials. We set
out to develop an optimal search strategy for publications on diagnostic test
evaluations in general, that could be added to keywords describing the specific
diagnostic test at issue. Nine Family Medicine journals were searched from 1992
through 1995 for primary publications on diagnostic test evaluation by hand
searching and a Medline search strategy published earlier. Additionally, new
search strategies have been developed with stepwise logistic regression, using
Mesh terms and free text words related to diagnosis and test evaluation as
independent variables. Hand searching identified 75 primary publications on
diagnostic test evaluation from a total of 2467 primary publications. The
previously published search strategy had a sensitivity of 73%, a specificity of
94%, and a positive predictive value of 29%. The most accurate new search
strategy had a sensitivity of 80.0% (60/75; 95% CI: 71.0-89.1), a specificity of
97.3% (2327/2392; 95% CI; 96.6-97.9%), a positive predictive value of 48% (95%
CI: 40-56) and diagnostic odds ratio of 149. All four new strategies used the
Mesh term "sensitivity and specificity" (exploded with the Mesh terms "predictive
value" and "ROC")and cumulatively added the text words "specificity," "false
negative," "accuracy," and "screening." The search strategy using the Mesh term
"sensitivity and specificity" (exploded) and the text words "specificity," "false
negative," and "accuracy" has both higher sensitivity and specificity than the
previously published strategy. The increase in specificity in three strategies
reduces the absolute number of false-positive articles that have to be screened
by 50-75%, compared to the number of false positives in the earlier strategy.
PMID- 10693906
TI - A new surrogate variable for erectile dysfunction status in the Massachusetts
male aging study.
AB - Erectile dysfunction (ED) is the subject of a vast clinical literature, but
little information has been gathered from random samples of the general public.
The Massachusetts Male Aging Study (MMAS) addressed this important aspect of
men's health. The MMAS was conducted in two waves, with baseline data collection
in 1987-1989 and follow-up in 1995-1997. Subsequent to the baseline MMAS survey,
a consensus developed that subjective measures are optimal for defining ED.
Unfortunately, the baseline questionnaire did not ask subjects directly about
their erectile functioning. Thus, we previously assigned the MMAS subjects a
degree of impotence at baseline using a series of related questions, employing a
discriminant formula constructed from a separate sample of urology clinic
patients. At follow-up the men classified themselves directly in addition to
answering the original series of related questions. In the present article, we
report the results of a new discriminant function, based on the MMAS men at
follow-up. We also compare the two methods and discuss our reasons for preferring
the internally calibrated method.
PMID- 10693907
TI - Within-center correlation in dialysis adequacy.
AB - The purpose of this study was to determine whether patients with end stage renal
disease treated with hemodialysis were correlated in dialysis adequacy within
facilities. This was a retrospective analysis of dialysis adequacy based on urea
reduction ratio (URR) values from 6969 patients dialyzed at 154 facilities. The
within-center correlation was quantified using the between-center variation and
the parameter p that was derived using ANOVA tables and mixed effects models. The
variation in center means for URR was wider than expected for independent
observations (52.9-76.1 versus 60.7-73.8, respectively). Furthermore, there was a
significant within-center correlation in URR values across all facilities (p =
0.136, P<0.0001), which persisted after adjusting for patient specific
covariates, facility characteristics, and state. In conclusion, there was a
substantial within-center correlation in dialysis adequacy that reflected
important center effects on the outcome of ESRD patients.
PMID- 10693908
TI - Alcohol exposure and health services utilization in older veterans.
AB - The objective of this study was to determine if increased alcohol exposure is
associated with greater use of health services among older veterans. A total of
129 older veterans (> or =65 years old), receiving longitudinal care in a
Veterans' Administration primary care clinic, were followed retrospectively for
up to 42 months. Subjects were screened at baseline for problem drinking with the
CAGE or the quantity-frequency questions from the Alcohol Use Disorders
Identification Test (QF-AUDIT), and stratified by exposure into three categories:
abstainers, social drinkers, and problem drinkers. Outcomes included total
outpatient clinic visits, laboratory tests, radiologic and other technologic
procedures, as well as acute care hospitalizations. For all subjects (N = 129),
no association was found between alcohol exposure and use of any outpatient
services. Among CAGE-screened (n = 62) abstainers, social drinkers, and problem
drinkers, significant differences were found in the median number of laboratory
tests (7.3 vs. 3.4 vs. 7.1, P = 0.004) and hospitalizations (0.3 vs. 0.0 vs. 0.3,
P = 0.001) per patient year of follow-up. No exposure-outcome associations were
present, however, among QF-AUDIT-screened subjects (n = 67). We were unable to
demonstrate a consistent relationship between alcohol exposure and health
services utilization. The effects of alcohol on older veterans' use of health
services varied with the method used to measure alcohol exposure. Additional
studies are needed to determine whether multiple, or possibly new, measures can
more precisely define the health effects of alcohol in older populations.
PMID- 10693909
TI - Serum C-reactive protein and fibrinogen concentrations and self-reported angina
pectoris and myocardial infarction: findings from National Health and Nutrition
Examination Survey III.
AB - C-reactive protein may predict the risk of cardiovascular disease, but its
association with angina pectoris in the general population has not been clearly
established, however. We used data from National Health and Nutrition Examination
Survey III conducted from 1988-1994 to examine the associations between serum C
reactive protein and plasma fibrinogen concentrations and self-reported angina
pectoris and myocardial infarction among 7,948 U.S. men and women aged 40 years
and older. C-reactive protein and fibrinogen concentrations were moderately
correlated (r = 0.43). After adjustment for age, sex, race or ethnicity,
education, smoking status, systolic blood pressure, serum cholesterol, high
density lipoprotein cholesterol, history of diabetes mellitus, body mass index,
and physical activity, fibrinogen (but not C-reactive protein) concentration was
significantly associated with self-reported angina pectoris. Neither fibrinogen
or C-reactive protein concentrations were significantly associated with angina
pectoris when entered in the model simultaneously. C-reactive protein and
fibrinogen concentrations were positively associated with myocardial infarction
when entered separately into models, but only C-reactive protein concentration
was significantly associated with myocardial infarction when both variables were
entered simultaneously. These cross-sectional data showed a significant positive
association between C-reactive protein concentration and myocardial infarction
but not self-reported angina pectoris in the U.S. population.
PMID- 10693910
TI - Mortality, hospital discharges, and case fatality for pulmonary embolism in the
Twin Cities: 1980-1995.
AB - Pulmonary embolism (PE) causes substantial morbidity and mortality, but little
information is available regarding recent secular trends for PE. This study
determined trends for PE in adults ages 30 to 84 years in the Minneapolis-St.
Paul metropolitan area from 1980 to 1995. The age-adjusted mortality rate for PE
decreased approximately 50% during the study period; the rate ratio (RR) for 1992
95 compared to 1980-83 was 0.41 in men [95% confidence interval (CI) 0.31-0.55]
and was 0.60 in women (95% CI 0.46-0.79). The hospital discharge rate for PE also
decreased from 1980-83 to 1988-91 (RR 0.69, 95% CI 0.63-0.76 in men; RR 0.72, 95%
CI 0.66-0.78 in women), but increased slightly between 1988-91 and 1992-95. The
case fatality rate for PE decreased approximately 60% during the period (RR 0.38,
95% CI 0.28-0.51 in men; RR 0.37, 95% CI 0.28-0.50 in women). The PE trends were
paralleled by declining hospital discharge rates for phlebitis and
thrombophlebitis. These data support a changing natural history or possible
improvements in the prevention, diagnosis, and treatment of PE between 1980 and
1995.
PMID- 10693911
TI - Oxidative stress: introduction.
PMID- 10693912
TI - What is oxidative stress?
AB - Oxidative stress, defined as a disturbance in the balance between the production
of reactive oxygen species (free radicals) and antioxidant defenses, is discussed
in relation to its possible role in the production of tissue damage in diabetes
mellitus. Important free radicals are described and biological sources of origin
discussed, together with the major antioxidant defense mechanisms. Examples of
the possible consequences of free radical damage are provided with special
emphasis on lipid peroxidation. Finally, the question of whether oxidative stress
is increased in diabetes mellitus is discussed.
PMID- 10693913
TI - Negative consequences of glycation.
AB - The Diabetes Control and Complications Trial (DCCT) established unequivocally
that the effects of inadequate insulin action (as monitored by the level of
hyperglycemia) are associated with the incidence and progression of diabetic
retinopathy, nephropathy, and neuropathy. How does hyperglycemia induce the
functional and morphologic changes that characterize diabetic complications?
Increasing evidence points to a major role for sugar-derived advanced glycation
end products (AGEs), which form inside and outside cells as a function of glucose
concentration. Recent work in this area supports a central role for reactive
oxygen species (ROS) in both the formation of AGEs, and in AGE-induced pathologic
alterations in gene expression. Inhibition of ROS may also be centrally important
in the action of drugs that prevent complications in diabetic animal models.
PMID- 10693914
TI - Gliclazide scavenges hydroxyl and superoxide radicals: an electron spin resonance
study.
AB - The role of reactive oxygen species in diabetes and its complications are well
known. Two therapeutic agents commonly used in the treatment of diabetes are the
sulfonylureas gliclazide and glibenclamide. These drugs effectively reduce blood
sugar in non-insulin-dependent diabetes mellitus, by augmenting insulin release.
Gliclazide is known to be a general free radical scavenger as shown by its
inhibition of o-dianisidine photo-oxidation. In this study, the effects of
gliclazide and glibenclamide on free radicals were examined in vitro, using
electron spin resonance spectroscopy. Superoxide radical (O2*-) generated from
the hypoxanthine-xanthine oxidase system or hydroxyl radical (OH*) generated via
the Fenton reaction were analyzed as spin adducts of 5,5-dimethyl-1-pyrroline-N
oxide (DMPO). Gliclazide scavenged O2*- and OH* in a dose-dependent manner
whereas glibenclamide was without effect. These findings suggest that gliclazide
is not only effective in reducing blood sugar, but may also be beneficial as a
result of inhibition of lipid and protein denaturation, which is believed to lead
to the development of diabetic complications.
PMID- 10693915
TI - Gliclazide decreases low-density lipoprotein oxidation and monocyte adhesion to
the endothelium.
AB - Increasing evidence implicates oxidized low-density lipoprotein (LDL) and
advanced glycation end products (AGE) in the atherogenesis associated with
diabetes mellitus. In the present study, we examined the in vitro effects of
gliclazide on LDL oxidation and monocyte adhesion to endothelial cells induced by
oxidized LDL and glycated albumin. To assess the clinical relevance of our in
vitro findings, we also measured the effect on monocyte adhesion of gliclazide
administration to type 2 diabetic patients. Incubation of human monocytes and
endothelial cells with increasing concentrations of gliclazide (0 to 10
microg/mL) and native LDL (100 microg/mL) induced a dose-dependent diminution of
cell-mediated LDL oxidation. Pretreatment of endothelial cells with gliclazide (0
to 10 microg/mL) before addition of native LDL (100 microg/mL) or glycated
albumin (100 microg/mL) resulted in a dose-dependent diminution of oxidized LDL-
and glycated albumin-induced monocyte adhesion to endothelial cells. In type 2
diabetic patients, administration of gliclazide inhibits the increased
adhesiveness of monocytes to levels similar to those observed in control
subjects. These results indicate that gliclazide is an antioxidant and suggest a
beneficial effect of this drug in the prevention of atherosclerosis associated
with type 2 diabetes.
PMID- 10693916
TI - Free radical scavenging activity of sulfonylureas: a clinical assessment of the
effect of gliclazide.
AB - In long-term clinical studies the beneficial effects of gliclazide on platelets
have been related to a reduction in oxidative stress. This property is because of
gliclazide's free radical scavenging ability that relates to the unique amino
azabicyclo-octare ring, which is grafted on to the sulfonylurea. During a blinded
clinical trial, the possible effects of gliclazide were assessed in 30 non
insulin-dependent diabetic patients. All patients had been treated for diabetes
for more than 2 years (mean 8 years) and had been established on glibenclamide
for over 2 years with or without adjunctive metformin therapy. Patients were
studied for 6 months and randomized to continue either their present dose of
glibenclamide or to be converted to an equipotent dose of gliclazide.
Measurements were taken of hemostatic variables, the oxidative status of the
plasma, and the redox status, both extracellularly as plasma albumin-thiols (PSH)
and lipid peroxides, and intracellularly as red blood cell superoxide dismutase
activity (SOD). At 3 months, diabetic control was unaltered, but there were
significant improvements in the oxidative status of the gliclazide-treated
patients. Lipid peroxides decreased (8.3 +/- 1.1 to 7.0 +/- .06 micromol/L, P <
.01) and red blood cell SOD increased (135 +/- 21 to 152 +/- 36 microg/mL, P <
.05). PSH levels were unaltered at 458 +/- 38 micromol/L, whereas they had
decreased significantly in the glibenclamide patients (414 +/- 34 micromol/L, P <
.05), resulting in a significant difference between the 2 treatment groups (P <
.004). Platelet reactivity to collagen also improved in the gliclazide-treated
patients, decreasing from 65.1% +/- 14% to 50.8% +/- 24% (P < .01). The
reactivity of the platelets remained unaltered in the glibenclamide patients. At
6 months, the significant differences between the 2 treatment groups remained.
Hence, gliclazide was shown in a clinical study to have free radical scavenging
activity independent of glycemic control.
PMID- 10693917
TI - Oxidative stress and glycemic regulation.
AB - Oxidative stress is an acknowledged pathogenetic mechanism in diabetic
complications. Hyperglycemia is a widely known cause of enhanced free radical
concentration, whereas oxidative stress involvement in glycemic regulation is
still debated. Glucose transport is a cascade of events starting from the
interaction of insulin with its own receptor at the plasma membrane and ending
with intracellular glucose metabolism. In this complex series of events, each
step plays an important role and can be inhibited by a negative effect of
oxidative stress. Several studies show that an acute increase in the blood
glucose level may impair the physiological homeostasis of many systems in living
organisms. The mechanisms through which acute hyperglycemia exerts these effects
may be identified in the production of free radicals. It has been suggested that
insulin resistance may be accompanied by intracellular production of free
radicals. In adipocytes cultured in vitro, insulin increases the production of
hydrogen peroxide, which has been shown to mimic the action of insulin. These
data allow us to hypothesize that a vicious circle between hyperinsulinemia and
free radicals could be operating: insulin resistance might cause elevated plasma
free radical concentrations, which, in turn, might be responsible for a
deterioration of insulin action, with hyperglycemia being a contributory factor.
Data supporting this hypothesis are available. Vitamin E improves insulin action
in healthy, elderly, and non-insulin-dependent diabetic subjects. Similar results
can be obtained by vitamin C administration.
PMID- 10693918
TI - Clinical relevance of the oxidative stress concept.
AB - Subjects with type 2 diabetes have markedly increased rates of coronary heart
disease (CHD) that are only partly explained by the increased levels of
conventional cardiovascular risk factors such as total cholesterol, hypertension,
and smoking. Although an increasing number of studies have suggested a role for
glycemia in cardiovascular disease, considerable controversy remains. This issue
may be resolved when the results of the UK Prospective Diabetes Study (UKPDS) are
presented. One possible promising relatively new risk factor that may explain
high levels of CHD in diabetic subjects is increased oxidative stress. Type 2
diabetic subjects have an increased preponderance of small dense low-density
lipoprotein (LDL), which predisposes to the oxidation of LDL. Almost all studies
show that diabetic subjects have increased oxidative stress. In addition, they
may have lower levels of alpha-tocopherol. In most studies, increased oxidative
stress has been associated with cardiovascular disease, although prospective data
are lacking. If levels of oxidative stress are increased, what are the best
levels to reduce it to? Improved glycemic control has been associated with
decreased oxidative stress. Antioxidant replacement such as alpha-tocopherol may
also be beneficial. Interestingly, some special properties of hypoglycemic agents
have been described. Gliclazide has been reported to favorably affect both free
radicals and platelet reactivity. Gliclazide may have a more favorable effect on
tissue plasminogen activator (tPA) than tolbutamide. In conclusion, increased
levels of oxidative stress may underlie some of the increased risk of
cardiovascular disease in diabetic subjects. Interventions to decrease levels of
oxidative stress by methods such as improved glycemic control, antioxidant
therapy (ie, alpha-tocopherol), and gliclazide are indicated.
PMID- 10693919
TI - Cytokines that signal through the leukemia inhibitory factor receptor-beta
complex in the nervous system.
AB - Cytokines that signal through the leukemia inhibitory factor (LIF) receptor, such
as LIF and ciliary neuronotrophic factor, have a wide range of roles within both
the developing and mature nervous system. They play a vital role in the
differentiation of neural precursor cells into astrocytes and can prevent or
promote neuronal differentiation. One of the conundrums regarding signalling
through the LIF receptor is how it can have multiple, often conflicting roles in
different cell types, such as enhancing the differentiation of astrocytes while
inhibiting the differentiation of some neuronal cells. Factors that can modulate
signal transduction downstream of cytokine signalling, such as "suppressor of
cytokine signalling" proteins, which inhibit the JAK/STAT but not the mitogen
activated protein kinase pathway, may therefore play an important role in
determining how a given cell will respond to cytokine signalling. This review
discusses the general effects of cytokine signalling within the nervous system.
Special emphasis is placed on differentiation of neural precursor cells and the
role that regulation of cytokine signalling may play in how a given precursor
cell responds to cytokine stimulation.
PMID- 10693920
TI - Amtyr1: characterization of a gene from honeybee (Apis mellifera) brain encoding
a functional tyramine receptor.
AB - Biogenic amine receptors are involved in the regulation and modulation of various
physiological and behavioral processes in both vertebrates and invertebrates. We
have cloned a member of this gene family from the CNS of the honeybee, Apis
mellifera. The deduced amino acid sequence is homologous to tyramine receptors
cloned from Locusta migratoria and Drosophila melanogaster as well as to an
octopamine receptor cloned from Heliothis virescens. Functional properties of the
honeybee receptor were studied in stably transfected human embryonic kidney 293
cells. Tyramine reduced forskolin-induced cyclic AMP production in a dose
dependent manner with an EC50 of approximately 130 nM. A similar effect of
tyramine was observed in membrane homogenates of honeybee brains. Octopamine also
reduced cyclic AMP production in the transfected cell line but was both less
potent (EC50 of approximately 3 microM) and less efficacious than tyramine.
Receptor-encoding mRNA has a wide-spread distribution in the brain and
subesophageal ganglion of the honeybee, suggesting that this tyramine receptor is
involved in sensory signal processing as well as in higher-order brain functions.
PMID- 10693921
TI - Differential effects of corticostriatal and thalamostriatal deafferentation on
expression of the glutamate transporter GLT1 in the rat striatum.
AB - This study compared the effects of the disruption of the two main presumably
glutamatergic striatal inputs, the corticostriatal and thalamostriatal pathways,
on GLT1 expression in the rat striatum, using in situ hybridization and
immunohistochemistry. Unilateral ibotenate-induced thalamic lesion produced no
significant changes in striatal GLT1 mRNA labeling and immunostaining as assessed
at 5 and 12 days postlesion. In contrast, significant increases in both
parameters were measured after bilateral cortical lesion by superficial
thermocoagulation. GLT1 mRNA levels increased predominantly in the dorsolateral
part of the striatum; there, the increases were significant at 5 (+84%), 12
(+101%), and 21 (+45%) but not at 35 days postlesion. GLT1 immunostaining
increased significantly and homogeneously by 17-26% at 12 and 21 days postlesion.
The increase in GLT1 expression at 12 days postlesion was further confirmed by
western blot analysis; in contrast, a 36% decrease in glutamate uptake activity
was measured at the same time point. These data indicate that striatal GLT1
expression depends on corticostriatal but not thalamostriatal innervation.
Comparison of our results with previous data showing that cortical lesion by
aspiration downregulates striatal GLT1 expression further suggests that
differential changes in GLT1 expression, and thus presumably in glial cell
function, may occur in the target striatum depending on the way the cortical
neurons degenerate.
PMID- 10693922
TI - Cyclic AMP-mediated regulation of GABA(A) receptor subunit expression in mature
rat cerebellar granule cells: evidence for transcriptional and translational
control.
AB - Exposure of rat cerebellar granule cells cultured to maturity in vitro to
forskolin, N6,2'-O-dibutyryladenosine 3',5'-cyclic monophosphate (Bt2cAMP), and 3
isobutyl-1-methylxanthine (IBMX) down-regulated GABA(A) receptor alpha6 and beta3
subunits but up-regulated alpha1 and beta2 subunits with respect to vehicle
treated controls. Dideoxyforskolin had no effect on subunit expression. Protein
kinase A inhibitors, H-89 and Rp-adenosine 3',5'cyclic monophosphothioate,
prevented these effects on alpha1 but not alpha6 subunit expression.
Flunitrazepam-sensitive [3H]Ro 15-4513 binding sites were increased by 144 +/-
20% following forskolin treatment. [3H]Ro 15-4513 photoaffinity labelling showed
that the GABA(A) receptor alpha1 subunit was the principal locus of the increased
flunitrazepam-sensitive [3H]Ro 15-4513 binding. Forskolin decreased flunitrazepam
insensitive [3H]Ro 15-4513 binding sites by 25 +/- 8% and resulted in a 20%
decrease in the irreversible incorporation of radioactivity in the alpha6
subunit. Steady-state levels of GABA(A) receptor subunit mRNAs were determined by
semiquantitative RT-PCR in forskolin-treated cultures. Forskolin, Bt2cAMP, and
IBMX down-regulated GABA(A) receptor alpha6 subunit mRNA expression; alpha1 and
beta3 mRNA levels were unaffected, whereas beta2 subunit mRNA was up-regulated.
Dideoxyforskolin had no significant effect on alpha1, alpha6, beta2, and beta3
mRNA levels. Thus, in mature cerebellar granule cells, GABA(A) receptor
expression can be regulated by intracellular cyclic AMP levels. This occurs at
the level of gene transcription and/or translation by mechanisms that are only
partially governed by protein kinase A.
PMID- 10693923
TI - Phorbol ester activation of the neuronal nicotinic acetylcholine receptor alpha7
subunit gene: involvement of transcription factor Egr-1.
AB - alpha-Bungarotoxin-sensitive neuronal nicotinic acetylcholine receptors from
bovine adrenomedullary chromaffin cells are up-regulated by long-term exposure to
phorbol esters. The rise in receptor density is paralleled by an increase in
transcripts corresponding to the alpha7 subunit, which is a component of this
receptor subtype. Transcriptional activation of the alpha7 subunit gene is
evidenced in reporter gene transfection experiments, in which phorbol esters
increase alpha7 promoter activity by up to 14-fold. About 80% of this activation
is abolished when at least two of the three sites for the immediate-early
transcription factor Egr-1, present in the proximal promoter region of the alpha7
subunit gene, are mutated simultaneously. In addition, phorbol esters elevate
both Egr-1 mRNA and Egr-1 protein levels in chromaffin cells, whereas
electrophoretic mobility shift assays show that the Egr-1 component of the
complexes that originate at the alpha7 promoter increases in cells treated with
phorbol esters. These results suggest that the transcription factor Egr-1 is
involved in triggering expression of alpha-bungarotoxin-sensitive nicotinic
receptors in response to external stimuli, such as the ones resulting from
phorbol ester treatment, and support our previous hypothesis that the alpha7
subunit gene is one of the specific targets for Egr-1.
PMID- 10693924
TI - A proteolipid protein-specific pre-mRNA (Ppm-1) contains intron 3 and is up
regulated during myelination in the CNS.
AB - Alternative splicing of the precursor for messenger RNA (pre-mRNA) is a common
process utilised by higher eukaryotes to modulate gene expression. A single
primary transcript may generate several proteins with distinct functions,
expressed in tissue-specific, developmental patterns. This article describes an
oligodendrocyte-specific pre-mRNA product of proteolipid protein gene (P/p)
transcription, which is the precursor for P/p but not Dm20 mRNA in the CNS. This
P/p-specific pre-mRNA (Ppm-1) includes the intact intron 3 of the P/p gene. It is
first expressed during active myelination, and it localises to the nucleus of
oligodendrocytes, in both normal and jimpy (jp) murine CNS. In addition to mouse,
Ppm-1 is found also in rat and dog, but not toad or trout. Our work suggests that
alternative splicing of the P/p gene primary transcript follows a branching
pattern, resulting in the presence of at least one P/p isoform-specific pre-mRNA
molecule, Ppm-1. Therefore, Dm20 mRNA may be the product of a divergent set of
pre-mRNA splicing events.
PMID- 10693925
TI - Major phosphorylation site (Ser55) of neurofilament L by cyclic AMP-dependent
protein kinase in rat primary neuronal culture.
AB - Ser55 of neurofilament L (NF-L) is reported to be partly phosphorylated in
neurons and to be phosphorylated by cyclic AMP-dependent protein kinase (PKA).
Bovine NF-L was phosphorylated by PKA in a low concentration of MgCl2 (0.3 mM)
and digested by trypsin. Trypsin-digested fragments were assigned by MALDI/ TOF
(matrix-assisted laser desorption and ionization/ time-of-flight) mass
spectrometry. Phosphorylation sites were found at Ser41, Ser55, and Ser62 in the
head region, with Ser55 considered the preferred site. A site-specific
phosphorylation-dependent antibody against Ser55 rendered NF-L phosphorylated at
Ser55 detectable in primary cultured rat neurons. One-hour treatment with 20 nM
okadaic acid increased the phosphorylation level of Ser55, and co-treatment with
10 microM forskolin enhanced it. However, forskolin alone did not elevate the
phosphorylation level. As a consequence, NF-L may be phosphorylated at Ser55 by
PKA or by a PKA-like kinase in vivo; however, the phosphorylation level of Ser55
may be modulated by certain phosphatases sensitive to okadaic acid.
PMID- 10693926
TI - Opioids transiently prevent activation of apoptotic mechanisms following short
periods of serum withdrawal.
AB - Opioids exert a proapoptotic effect on several normal and tumoral cells. The aim
of the present article was to examine the effect of opioids on the PC12 rat
pheochromocytoma cell line, a model for the study of chromaffin cell apoptosis.
These cells produce delta- and kappa-opioid agonists and their receptors. Our
results were as follows: The kappa- and delta2-opioid receptor agonists had a
rapid but transient effect on apoptosis at 3 h, whereas mu opioids did not. The
effect of opioids was reversible by the opioid antagonists naloxone and nor
binaltorphimine. The effect of opioids was protective, suppressing serum
deprivation-induced apoptosis to approximately 50% of controls. The protective
effect of opioids on PC12 apoptosis was measurable only under serum deprivation.
The effect of opioids was remarkably reproducible and highly constant in timing,
which did not appear to depend on the duration of the preceding serum
deprivation. Finally, opioids prevented the elevation of the Bcl-2 and Bak
proteins following serum deprivation to the levels attained by serum
supplementation. Our combined data suggest that opioids protect PC12 cells from
entering a state of induced apoptosis following serum deprivation.
PMID- 10693927
TI - Enhancement of dopaminergic neurotoxicity by the mercapturate of dopamine:
relevance to Parkinson's disease.
AB - The mechanisms that underlie dopaminergic neurodegeneration in Parkinson's
disease (PD) are not known but have been proposed to involve oxidation of
dopamine and related catechols. In other organ systems, cytotoxicity from
catechol oxidation is profoundly influenced by mercapturate metabolism. Here we
have tested the hypothesis that catechol thioethers produced in the mercapturic
acid pathway may act as dopaminergic neurotoxins. A rat
mesencephalic/neuroblastoma hybrid (MES) cell line was exposed to dopamine, 3,4
dihydroxyphenylacetic acid (DOPAC), or eight different catechol thioethers for up
to 24 h, and the extent of apoptosis was quantified by a microculture kinetic
assay. Apoptosis also was confirmed morphologically with Giemsa-stained cultures
and by demonstration of internucleosomal DNA fragmentation. The results showed
that dopamine at 5-50 microM produced concentration-dependent increases in the
percentage of apoptotic MES cells. At 25 and 50 microM dopamine, the maximal
proportions of apoptotic cells were detected at approximately 19 (20.7 +/- 2.0%)
and 14 h (30.3 +/- 3.5%), respectively. None of the catechol thioethers (up to 5
microM) alone induced significant apoptosis in MES cells. However, when MES cells
were incubated with dopamine (25 microM) and catechol thioethers (5 microM) to
mimic pathological conditions, 5-S-N-acetylcysteinyldopamine, 5-S
homocysteinyldopamine, and 5-S-homocysteinyl-DOPAC significantly increased the
percentage of apoptotic cells compared with dopamine alone. These results suggest
that mercapturate metabolism of endogenous catechols may yield products that
facilitate dopaminergic neurodegeneration.
PMID- 10693928
TI - ErbB-4 activation promotes neurite outgrowth in PC12 cells.
AB - Neu differentiation factor (NDF; also known as neuregulin) induces a pleiotropic
cellular response that is cell type-dependent. NDF and its receptor ErbB-4 are
highly expressed in neurons, implying important roles in neuronal cell functions.
In the present study we demonstrate that ErbB-4 receptors expressed in PC12 cells
mediate NDF-induced signals and neurite outgrowth that are indistinguishable from
those mediated by the nerve growth factor-activated Trk receptors. In PC12-ErbB-4
cells but not in PC12 cells, NDF induced an initial weak mitogenic signal and
subsequently neurite outgrowth. The NDF-induced differentiation in PC12-ErbB-4
cells was mimicked by the pan-ErbB ligand betacellulin but not by other epidermal
growth factor-like ligands. Thus, NDF and betacellulin mediate similar activities
through the ErbB-4 receptor. Indeed, only these ligands induced strong
phosphorylation of the ErbB-4 receptors. Neurite outgrowth induced by NDF in PC12
ErbB-4 cells was accompanied by sustained activation of mitogen-activated protein
kinase (MAPK) and induction of the neural differentiation marker GAP-43.
Inhibition of the MAPK kinase MEK or of protein kinase C (PKC) blocked NDF
induced differentiation, whereas elevation of cyclic AMP levels enhanced the
response. Taken together, these results indicate that neurite outgrowth induced
by ErbB-4 in PC12 cells requires MAPK and PKC signaling networks.
PMID- 10693929
TI - Brief exposure to neurotrophins produces a calcium-dependent increase in choline
acetyltransferase activity in cultured rat septal neurons.
AB - We demonstrate that brief (30-min) exposure of cultured embryonic rat septal
neurons to neurotrophins (NTs) increases choline acetyltransferase (ChAT)
activity by 20-50% for all tested NTs (nerve growth factor, brain-derived
neurotrophic factor, neurotrophin-3, and neurotrophin-4, each at 100 ng/ml). The
increase in ChAT activity was first detected 12 h after NT exposure, persisted at
least 48 h, and was not mediated by increased neuronal survival or action
potential activity. Under some conditions, the response to brief NT exposure was
as great as that produced by continuous exposure. NT stimulation of ChAT activity
was inhibited by inhibitors of p75- and Trk kinase-mediated signaling, by removal
of extracellular Ca2+ during the period of NT exposure, and by buffering
intracellular Ca2+ with BAPTA. Application of nerve growth factor and brain
derived neurotrophic factor transiently increased [Ca2+] within a subpopulation
of neurons. NT stimulation of ChAT activity was not affected significantly by
cyclic AMP agonists or antagonists. These findings suggest that brief exposure to
NTs can have a long-lasting effect on cholinergic transmission, and that this
effect requires Ca2+, but not cyclic AMP.
PMID- 10693930
TI - Glucocorticoids exacerbate the deleterious effects of gp120 in hippocampal and
cortical explants.
AB - Glucocorticoids (GCs), the adrenal steroids secreted during stress, can
compromise the ability of hippocampal neurons to survive numerous necrotic
insults. We have previously observed that GCs worsen the deleterious effects of
gp120, the glycoprotein of the acquired immune deficiency syndrome virus, which
can indirectly damage neurons and which is thought to play a role in the
neuropathological features of human immunodeficiency virus infection.
Specifically, GCs augment gp120-induced calcium mobilization, ATP depletion,
decline in mitochondrial potential, and neurotoxicity in fetal monolayer cultures
from a number of brain regions. In the present report, we demonstrate a similar
gp120/GC synergy in adult hippocampal and cortical explants. We generated
explants from rats that were either adrenalectomized, adrenally intact, or intact
and treated with corticosterone to produce levels seen in response to major
stressors. Metabolic rates in explants were then indirectly assessed with silicon
microphysiometry, and cytosolic calcium concentrations were assessed with fura-2
fluorescent microscopy. We observed that basal levels of GCs tonically augment
the disruptive effects of gp120 on metabolism in the CA1 cell field of the
hippocampus and in the cortex. Moreover, raising GC concentrations into the
stress range exacerbated the ability of gp120 to mobilize cytosolic calcium in a
number of hippocampal cell fields. Finally, we observed that the synthetic GC
prednisone had similarly exacerbating effects on gp120. Thus, GCs can worsen the
deleterious effects of gp120 in a system that is more physiologically relevant
than the fetal monolayer culture and in a region-specific manner.
PMID- 10693931
TI - Apolipoprotein E exhibits isoform-specific promotion of lipid efflux from
astrocytes and neurons in culture.
AB - Many studies have shown that apolipoprotein E (apoE) plays important roles in
maintaining intracellular lipid homeostasis in nonneuronal cells. However, little
is known about the extracellular transport of lipids in the CNS. In this study,
we determined whether and to what degree lipid efflux from astrocytes and neurons
depended on apoE. Our results showed that exogenously added apoE promoted the
efflux of cholesterol and phosphatidylcholine from both astrocytes and neurons in
culture, resulting in the generation of high-density lipoprotein-like particles.
The order of potency of the apoE isoforms as lipid acceptors was apoE2 > apoE3 =
apoE4 in astrocytes and apoE2 > apoE3 > apoE4 in neurons. Treatment with
brefeldin A, monensin, and a protein kinase C inhibitor, H7, abolished the
ability of apoE to promote cholesterol efflux from cultured astrocytes, without
altering apoE-mediated phosphatidylcholine efflux. In contrast, the efflux of
both cholesterol and phosphatidylcholine promoted by apoE was abolished following
treatment with heparinase or lactoferrin, which block the interaction of apoE
with heparan sulfate proteoglycans (HSPGs) or low-density lipoprotein receptor
related protein (LRP), respectively. This study suggests that apoE promotes lipid
efflux from astrocytes and neurons in an isoform-specific manner and that cell
surface HSPGs and/or HSPG-LRP pathway may mediate this apoE-promoted lipid
efflux.
PMID- 10693932
TI - Amyloid beta and amylin fibrils induce increases in proinflammatory cytokine and
chemokine production by THP-1 cells and murine microglia.
AB - Activated microglia surrounding amyloid beta-containing senile plaques synthesize
interleukin-1, an inflammatory cytokine that has been postulated to contribute to
Alzheimer's disease pathology. Studies have demonstrated that amyloid beta
treatment causes increased cytokine release in microglia and related cell
cultures. The present work evaluates the specificity of this cellular response by
comparing the effects of amyloid beta to that of amylin, another amyloidotic
peptide. Both lipopolysaccharide-treated THP-1 monocytes and mouse microglia
showed significant increases in mature interleukin-1beta release 48 h following
amyloid beta or human amylin treatment, whereas nonfibrillar rat amylin had no
effect on interleukin-1beta production by THP-1 cells. Lipopolysaccharide
stimulated THP-1 cells treated with amyloid beta or amylin also showed increased
release of the proinflammatory cytokines tumor necrosis factor-alpha and
interleukin-6, as well as the chemokines interleukin-8 and macrophage
inflammatory protein-1alpha and -1beta. THP-1 cells incubated with fibrillar
amyloid beta or amylin in the absence of lipopolysaccharide also showed
significant increases of both interleukin-1beta and tumor necrosis factor-alpha
mRNA. Furthermore, treatment of THP-1 cells with amyloid fibrils resulted in an
elevated expression of the immediate-early genes c-fos and junB. These studies
provide further evidence that fibrillar amyloid peptides can induce signal
transduction pathways that initiate an inflammatory response that is likely to
contribute to Alzheimer's disease pathology.
PMID- 10693933
TI - Fatty acid-activated K+ channels in autonomic neurons: activation by an
endogenous source of free fatty acids.
AB - Application of arachidonic acid evoked robust activation of large-conductance K+
channels in cell-attached and excised inside-out patches from acutely isolated
chick ciliary ganglion neurons. A similar effect was produced by 5,8,11,14
eicosatetraynoic acid, a nonmetabolizable analogue of arachidonic acid. The
unitary conductance of fatty acid-activated channels was 35-40 pS at +20 mV with
physiological gradients of K+ and 165 pS at +20 mV with an extracellular K+
concentration of 37.5 mM and an intracellular K+ concentration of 150 mM. Gating
of these channels in cell-attached patches was potentiated by membrane stretch.
Channel gating evoked by both lipids was concentration-dependent, with detectable
activation apparent at 4 microM in the majority of patches and maximal activation
occurring between 32 and 64 microM. Gating was relatively voltage-independent.
Large-conductance K+ channels were also activated in inside-out patches by the
monounsaturated fatty acid 11-cis-eicosenoic acid but not by the fully saturated
fatty acid arachidic acid. Application of 100 microM H2O2, an agent that
activates cytosolic phospholipase A2, also caused activation of large-conductance
K+ channels in intact neurons. The stimulatory effects of H2O2 were blocked by
pretreatment with 20 microM 4-bromophenacyl bromide, an irreversible inhibitor of
phospholipase A2. Therefore, mobilization of endogenous fatty acids can cause
activation of large-conductance K+ channels in autonomic neurons.
PMID- 10693934
TI - Differential regulation of cyclin D1 and D3 expression in the control of
astrocyte proliferation induced by endothelin-1.
AB - We have previously shown that the mitogenic effect of endothelin-1 (ET-1) in
primary astrocytes is dependent on activation of both extracellular signal
regulated kinase (ERK)- and cytoskeleton (CSK)-dependent pathways. In this study,
we evaluated the contribution of each of these pathways to the expression and
activation of proteins mediating cell cycle progression. Our results suggest that
ET-1-induced expression of cyclins D1 and D3 is dependent on the ERK- and CSK
dependent pathways, respectively; moreover, a decrease in the levels of the
cyclin-dependent kinase inhibitor (CKI) p27 was observed as a consequence of ERK
activation. Expression of both cyclins D1 and D3 together with a decrease in the
p27 levels are essential for retinoblastoma protein (pRB) phosphorylation and
cyclin A expression. Furthermore, the molecular events responsible for cell-cell
contact inhibition of astrocyte proliferation were found to be independent of the
mitogenic pathways leading to D-type cyclin expression. Cell growth arrest in
confluent astrocytes was found to be correlated with increased expression of CKI
p21, resulting in inhibition of D-type cyclin-associated pRB phosphorylation and
cyclin A expression. Taken together, these results indicate that cyclins D1 and
D3, which constitute the key mediators of the proliferative response of primary
astrocytes to ET-1, are regulated by distinct signaling pathways.
PMID- 10693935
TI - Turnover and down-regulation of GABA(A) receptor alpha1, beta2S, and gamma1
subunit mRNAs by neurons in culture.
AB - Benzodiazepines (BZDs), barbiturates, ethanol, and general anesthetics potentiate
the action of gamma-aminobutyric acid (GABA) at the type A GABA receptor
(GABA(A)R) and have profound effects on mood, arousal, and susceptibility to
seizures. GABA(A)R number and subunit mRNA levels change in animal models of
epilepsy and anxiety and following exposure to GABA(A)R agonists and positive
modulators, but the mechanism of receptor down-regulation remains unknown.
Persistent exposure (48 h) of brain neurons in primary culture to GABA results in
a 30% decrease in the levels of mRNA encoding the alpha1, beta2S, and gamma1
GABA(A)R subunit isoforms, which form a receptor enhanced by nonselective BZDs.
Down-regulation of alpha1 mRNA (t1/2 = 8 h) precedes down-regulation of receptor
number (t1/2 = 25 h), suggesting that GABA-induced GABA(A)R down-regulation is a
consequence of decreased mRNA levels. The apparent half-life of the alpha1 mRNA
in the presence of alpha-amanitin (9 h) is consistent with the time course of
alpha1 mRNA down-regulation. Moreover, the stability of the alpha1, beta2S, and
gamma1 subunit mRNAs is not altered by chronic GABA exposure. The results
demonstrate that GABA(A)R subunit mRNA down-regulation is not a consequence of
accelerated mRNA degradation and argue that GABA-induced GABA(A)R down-regulation
is due to inhibition of transcription.
PMID- 10693936
TI - Multiple calcium pathways induce the expression of SNAP-25 protein in chromaffin
cells.
AB - Incubation of bovine adrenal chromaffin cells in high K+ (38 mM) during 24-48 h
enhanced 2.5 to five times the expression of SNAP-25 protein and mRNA,
respectively. This increase was reduced 86% by furnidipine (an L-type Ca2+
channel blocker) but was unaffected by either omega-conotoxin GVIA (an N-type
Ca2+ channel blocker) or -agatoxin IVA (a P/Q-type Ca2+ channel blocker).
Combined blockade of N and P/Q channels with omega-conotoxin MVIIC did, however,
block by 76% the protein expression. The inhibitory effects of fumidipine were
partially reversed when the external Ca2+ concentration was raised from 1.6 to 5
mM. These findings, together with the fact that nicotinic receptor activation or
Ca2+ release from internal stores also enhanced SNAP-25 protein expression,
suggest that an increment of cytosolic Ca2+ concentration ([Ca2+]), rather than
its source or Ca2+ entry pathway, is the critical signal to induce the protein
expression. The greater coupling between L-type Ca2+ channels and protein
expression might be due to two facts: (a) L channels contributed 50% to the
global [Ca2+]i rise induced by 38 mM K+ in indo-1-loaded chromaffin cells and (b)
L channels undergo less inactivation than N or P/Q channels on sustained
stimulation of these cells.
PMID- 10693937
TI - Immunocytochemical localization of beta-methylcrotonyl-CoA carboxylase in
astroglial cells and neurons in culture.
AB - Astroglia-rich primary cultures and brain slices rapidly metabolize branched
chain amino acids (BCAAs), in particular leucine, as energy substrates. To
allocate the capacity to degrade leucine oxidatively in neural cells, we have
purified beta-methylcrotonyl-CoA carboxylase (beta-MCC) from rat liver as one of
the enzymes unique for the irreversible catabolic pathway of leucine. Polyclonal
antibodies raised against beta-MCC specifically cross-reacted with both enzyme
subunits in liver and brain homogenates. Immunocytochemical examination of
astroglia-rich rat primary cultures demonstrated the presence of beta-MCC in
astroglial cells, where the enzyme was found to be located in the mitochondria,
the same organelle that the mitochondrial isoform of the BCA(A) aminotransferase
(BCAT) is located in. This colocalization of the two enzymes supports the
hypothesis that mitochondrial BCAT is the isoenzyme that in brain energy
metabolism prepares the carbon skeleton of leucine for irreversible degradation
in astrocytes. Analysis of neuron-rich primary cultures revealed also that the
majority of neurons contained beta-MCC. The presence of beta-MCC in most neurons
demonstrates their ability to degrade the alpha-ketoisocaproate that could be
provided by neighboring astrocytes or could be generated locally from leucine by
the action of the cytosolic isoform of BCAT that is known to occur in neurons.
PMID- 10693938
TI - Immunoprecipitation of high-affinity, guanine nucleotide-sensitive, solubilized
mu-opioid receptors from rat brain: coimmunoprecipitation of the G proteins
G(alpha o), G(alpha i1), and G(alpha i3).
AB - Antibodies directed against the C-terminal and the N-terminal regions of the mu
opioid receptor were generated to identify the G proteins that
coimmunoprecipitate with the mu receptor. Two fusion proteins were constructed:
One contained the 50 C-terminal amino acids of the mu receptor, and the other
contained 61 amino acids near the N terminus of the receptor. Antisera directed
against both fusion proteins were capable of immunoprecipitating approximately
70% of solubilized rat brain mu receptors as determined by [3H][D-Ala2,N-Me
Phe4,Gly-ol5]-enkephalin ([3H]DAMGO) saturation binding. The material
immunoprecipitated with both of the antisera was recognized as a broad band with
a molecular mass between 60 and 75 kDa when screened in a western blot. Guanosine
5'-O-(3-thiotriphosphate) (GTPgammaS) had an EC50 of 0.4 nM in diminishing
[3H]DAMGO binding to the immunoprecipitated pellet. The ratio of G proteins to mu
receptors in the immunoprecipitated material was 1:1. When the material
immunoprecipitated with affinity-purified antibody was screened for the presence
of G protein a subunits, it was determined that G(alpha)o, G(alpha)i1,
G(alpha)i3, and to a lesser extent G(alpha)i2, but not G(alpha)s or G(alpha)q11,
were coimmunoprecipitated with the mu receptor. Inclusion of GTPgammaS during the
immunoprecipitation process abolished the coimmunoprecipitation of G proteins.
PMID- 10693939
TI - Attenuation and recovery of evoked overflow of striatal serotonin in rats treated
with neurotoxic doses of methamphetamine.
AB - Repeated administration of methamphetamine to animals can lead to long-lasting
decreases in striatal monoamine content. In the present study, the effects of
neurotoxic doses of methamphetamine on basal and evoked overflow of striatal
serotonin and of its primary metabolite 5-hydroxyindoleacetic acid were examined
in awake rats using in vivo microdialysis. Male Fischer-344 rats were
administered methamphetamine (5 mg/kg, s.c.) or saline four times in 1 day at 2-h
intervals. Microdialysis studies were carried out 1 week, 1 month, and 6 months
later. At 1 week posttreatment there were significant decreases in potassium- and
amphetamine-evoked overflow of serotonin in the striatum of the methamphetamine
treated animals. Basal extracellular levels of 5-hydroxyindoleacetic acid but not
of serotonin were also decreased. Evoked overflow of serotonin recovered by 1
month, and extracellular levels of 5-hydroxyindoleacetic acid had recovered by 6
months. Tissue levels of serotonin and 5-hydroxyindoleacetic acid were decreased
at 1 week posttreatment but back to control levels by 1 month after treatment.
These results indicate that presynaptic serotonergic functioning is attenuated in
the striatum of rats treated 1 week earlier with neurotoxic doses of
methamphetamine. However, in the model used, the changes are transient, and
recovery can occur within 1-6 months posttreatment.
PMID- 10693940
TI - Quantitative and statistical analysis of the shape of amperometric spikes
recorded from two populations of cells.
AB - Previously used methods of comparing amperometric spike characteristics from two
separate groups of cells have entailed pooling all the values for a spike
characteristic from each group of cells and then statistically comparing the two
samples. Although this approach has indicated that there are significant
differences between the spike characteristics from coloboma and control mouse
chromaffin cells, the results are not consistent between experiments. We have
reexamined the assumptions of the statistical tests used as well as the
variability inherent in amperometric data measured from two groups of cells. Our
findings indicate that when comparing amperometric spike characteristics between
groups of cells, it is more appropriate to compare samples of mean spike values.
This method consistently indicates that there is no difference between coloboma
and control amperometric spikes. These results have been validated by using
samples of mean spike characteristics to detect changes in the shape of
amperometric spikes from both mouse chromaffin cells at 37 degrees C and PC12
cells previously exposed to 50 microM L-3,4-dihydroxyphenylalanine and by the use
of an additional analysis method, the nested ANOVA. Together, these results
indicate that pooled samples of amperometric spike characteristics can give
results that may confound the interpretation of amperometric data.
PMID- 10693942
TI - Elevated N1-acetylspermidine levels in gerbil and rat brains after CNS injury.
AB - The polyamine system is very sensitive to different pathological states of the
brain and is perturbed after CNS injury. The main modifications are significant
increases in ornithine decarboxylase activity and an increase in tissue
putrescine levels. Previously we have shown that the specific polyamine oxidase
(PAO) inhibitor N1,N4-bis(2,3-butadienyl)-1,4-butanediamine (MDL 72527) reduced
the tissue putrescine levels, edema, and infarct volume after transient focal
cerebral ischemia in spontaneously hypertensive rats and traumatic brain injury
of Sprague-Dawley rats. In the present study, N1-acetyl-spermidine accumulation
was greater in injured brain regions compared with sham or contralateral regions
following inhibition of PAO by MDL 72527. This indicates spermidine/spermine-N1
acetyltransferase (SSAT) activation after CNS injury. The observed increase in N1
acetylspermidine levels at 1 day after CNS trauma paralleled the decrease in
putrescine levels after treatment with MDL 72527. This suggests that the
increased putrescine formation at 1 day after CNS injury is mediated by the
SSAT/PAO pathway, consistent with increased SSAT mRNA after transient ischemia.
PMID- 10693943
TI - Peptide fragments of beta-amyloid precursor protein: effects on parallel fiber
Purkinje cell synaptic transmission in rat cerebellum.
AB - The effects of peptide fragments of the beta-amyloid precursor protein (betaAPP)
on parallel fiber (PF)-Purkinje cell synaptic transmission in the rat cerebellum
were examined. Transient inward currents associated with calcium influx were
induced by localized applications of the 105-amino acid carboxy-terminal fragment
(CT105) of betaAPP to discrete dendritic regions of intact Purkinje cells.
betaAPP and the amyloid beta (Abeta) peptide fragments Abeta1-16, Abeta25-35, and
Abeta1-42 had little or no effect. Inward currents were also observed following
applications of CT105 to isolated patches of somatic Purkinje cell membrane. All
five proteins/peptides induced some depression of alpha-amino-3-hydroxy-5-methyl
4-isoxazole propionate (AMPA) receptor-mediated synaptic transmission between PFs
and Purkinje cells, through a combination of pre- and postsynaptic effects. CT105
induced the greatest depression, which spread to distant synapses following local
application and which was prevented by inhibition of nitric oxide synthase. These
data indicate that CT fragments of the betaAPP can modulate AMPA-mediated
glutamatergic synaptic transmission in the cerebellar cortex. These fragments may
therefore be considered alternative candidates for some of the neurotoxic effects
of Alzheimer's disease.
PMID- 10693941
TI - Up-regulation of base excision repair activity for 8-hydroxy-2'-deoxyguanosine in
the mouse brain after forebrain ischemia-reperfusion.
AB - The repair enzyme 8-oxoguanine glycosylase/ apyrimidinic/apurinic lyase (OGG)
removes 8-hydroxy-2'deoxyguanosine (oh8dG) in human cells. Our goal was to
examine oh8dG-removing activity in the cell nuclei of male C57BL/6 mouse brains
treated with either forebrain ischemia-reperfusion (FblR) or sham operations. We
found that the OGG activity in nuclear extracts, under the condition in which
other nucleases did not destroy the oligodeoxynucleotide duplex, excised oh8dG
with the greatest efficiency on the oligodeoxynucleotide duplex containing
oh8dG/dC and with less efficiency on the heteroduplex containing oh8dG/dT,
oh8dG/dG, or oh8dG/dA. This specificity was the same as for the recombinant type
1 OGG (OGG1) of humans. We observed that the OGG1 peptide and its activity in the
mouse brain were significantly increased after 90 min of ischemia and 20-30 min
of reperfusion. The increase in the protein level and in the activity of brain
OGG1 correlated positively with the elevation of FblR-induced DNA lesions in an
indicator gene (the c-fos gene) of the brain. The data suggest a possibility that
the OGG1 protein may excise oh8dG in the mouse brain and that the activity of
OGG1 may have a functional role in reducing oxidative gene damage in the brain
after FblR.
PMID- 10693944
TI - Substrate-bound beta-amyloid peptides inhibit cell adhesion and neurite outgrowth
in primary neuronal cultures.
AB - Accumulation of the beta-amyloid protein (Abeta) in the brain is an important
step in the pathogenesis of Alzheimer's disease. However, the mechanism of Abeta
toxicity remains unclear. Abeta can bind to the extracellular matrix, a structure
that regulates adhesive events such as neurite outgrowth and synaptogenesis. The
binding of Abeta to the extracellular matrix suggests that Abeta may disrupt cell
substrate interactions. Therefore, the effect of substrate-bound Abeta on the
growth of isolated chick sympathetic and mouse cortical neurons was examined.
Abeta1-40 and Abeta1-42 had dose-dependent effects on cell morphology. When
tissue culture plates were coated with 0.1-10 ng/well Abeta, neurite outgrowth
increased. Higher amounts of Abeta peptides (> or =3 microg/well) inhibited
outgrowth. The inhibitory effect was related to aggregation of the peptide, as
preincubation of Abeta1-40 for 24 h at 37 degrees C (a process known to increase
amyloid fibril formation) was necessary for inhibition of neurite outgrowth.
Abeta29-42, but not Abeta1-28, also inhibited neurite outgrowth at high
concentrations, demonstrating that the inhibitory domain is located within the
hydrophobic C-terminal region. Abeta1-40, Abeta1-42, and Abeta29-42 also
inhibited cell-substrate adhesion, indicating that the effect on neurite
outgrowth may have been due to inhibition of cell adhesion. The results suggest
that accumulation of Abeta may disrupt cell-adhesion mechanisms in vivo.
PMID- 10693945
TI - Increased generation of alternatively cleaved beta-amyloid peptides in cells
expressing mutants of the amyloid precursor protein defective in endocytosis.
AB - The subcellular location of the secretases processing the beta-amyloid precursor
protein (APP) is not established yet. We analyzed the generation of the beta
amyloid peptide (Abeta) in human embryonic kidney 293 cell lines stably
expressing wild-type and noninternalizing mutants of human APP. APP lacking the
entire cytoplasmic domain or with both tyrosine residues of the motif GYENPTY
mutated to alanine showed at least fivefold reduced endocytosis. In these cell
lines, the production of Abeta1-40 was substantially reduced, but accompanied by
the appearance of two prominent alternative Abeta peptides differing at the amino
termini. Based on antibody reactivity and mobility in high-resolution gels in
comparison with defined Abeta fragments, these peptides were identified as Abeta3
40 and Abeta5-40. Notably, these alternative Abeta peptides were not generated
when the APP mutants were retained in the early secretory pathway by treatment
with brefeldin A. These results indicate that the alternative processing is the
result of APP accumulation at the plasma membrane and provide evidence of
distinct beta-secretase activities. Cleavage amino-terminal to position 1 of
Abeta occurs predominantly in endosomes, whereas the processing at positions 3 or
5 takes place at the plasma membrane.
PMID- 10693946
TI - Immediate early gene expression in PC12 cells exposed to lead: requirement for
protein kinase C.
AB - We previously demonstrated induction of c-fos mRNA in PC12 cells exposed to lead
that was dependent on new transcription. In the current work, we examined two
signal transduction mechanisms that are activated by lead and have been shown to
mediate induction of c-fos mRNA. One mechanism involves protein kinase C, and the
other requires calmodulin-dependent protein kinase II. Significant increases in
the levels of c-fos, c-jun, and egr-1 but not NGFIB mRNA were observed in PC12
cells exposed to lead or phorbol 12-myristate 13-acetate. In contrast, PC12 cells
depolarized with 56 mM K+ displayed an increase in c-fos, egr-1, and NGFIB but
not c-jun mRNA. Similar to other activators of protein kinase C, lead increased
AP-1 and Egr-1 DNA binding activity. Additionally, lead increased luciferase
activity in cerebellar granule cells transfected with an AP-1 luciferase reporter
construct. Lead did not increase c-fos mRNA in PC12 cells that were depleted of
protein kinase C by a 24-h treatment with phorbol 12,13-dibutyrate or incubated
with the protein kinase C inhibitor H-7. In contrast, an inhibitor of calmodulin
dependent protein kinase, KN-62, and an inhibitor of calmodulin, W-7, did not
block the induction of c-fos mRNA by lead. An increase in serum-response element
DNA-binding activity was observed in nuclear extracts from PC12 cells exposed to
lead. It is interesting that lead activated protein kinase C isoforms delta and
epsilon, but not isoforms alpha and beta. In conclusion, lead appears to induce
the expression of immediate early genes by a mechanism that requires protein
kinase C.
PMID- 10693947
TI - Nigrostriatal reduction of aromatic L-amino acid decarboxylase activity in MPTP
treated squirrel monkeys: in vivo and in vitro investigations.
AB - Aromatic L-amino acid decarboxylase (AAAD) activity was examined in vivo with
positron emission tomography (PET) using 6-[18F]fluoro-L-DOPA (FDOPA) in squirrel
monkeys lesioned with graded doses of the neurotoxin 1-methyl-4-phenyl-1,2,3,6
tetrahydropyridine (MPTP). In vitro biochemical determinations of AAAD activity
in caudate, putamen, substantia nigra, and nucleus accumbens were performed in
the same animals to establish a direct comparison of in vivo and in vitro
measurements. In vivo and in vitro AAAD activities in caudate/ putamen were
substantially reduced in animals treated with the highest dose of MPTP (2.0
mg/kg). The percent change in the striatal FDOPA uptake (K(i)) and
decarboxylation rate constant (k3) values resulting from MPTP treatment showed
highly significant correlations with in vitro-determined AAAD activities.
However, decarboxylase rates within individual animals presented as approximately
10-fold difference between in vivo and in vitro values. Lower in vivo k3
measurements may be attributed to several possibilities, including transport
restrictions limiting substrate availability to AAAD within the neuron. In
addition, reductions in AAAD activity in the substantia nigra did not parallel
reductions in AAAD activity within the striatum, supporting the notion of a
nonlinear relationship between nigrostriatal cell degeneration and terminal
losses. This work further explores the role of AAAD in Parkinson's disease, a
more important factor than previously thought.
PMID- 10693948
TI - Chronic mitochondrial inhibition induces selective motoneuron death in vitro: a
new model for amyotrophic lateral sclerosis.
AB - Evidence is increasing that mitochondrial dysfunction is involved in amyotrophic
lateral sclerosis, a neurodegenerative disease characterized by selective
motoneuron death. To study the role of mitochondrial dysfunction in the pathways
leading to motoneuron death, we developed an in vitro model of chronic motoneuron
toxicity, based on malonate-induced inhibition of complex II in the mitochondrial
electron transport chain. Treatment with malonate resulted in a dose-dependent
decrease in cellular ATP levels. We observed that motoneurons were significantly
more vulnerable to mitochondrial inhibition than control neurons in the dorsal
horn. We could reproduce this dose-dependent phenomenon with the complex IV
inhibitor sodium azide. The free radical scavenger alpha-phenyl-N-tert
butylnitrone, the AMPA/kainate receptor blocker 6-cyano-7-nitroquinoxaline-2,3
dione, and riluzole, a drug that is currently used for the treatment of
amyotrophic lateral sclerosis, were protective against malonate-induced
motoneuron death. Furthermore, the caspase inhibitors N-benzyloxycarbonyl-Val-Ala
Asp-fluoromethyl ketone and z-Asp-Glu-Val-Asp-fluoromethyl ketone were both
protective against malonate toxicity. Our model shows that chronic mitochondrial
inhibition leads to selective motoneuron death, which is most likely apoptotic.
PMID- 10693949
TI - GluR1 glutamate receptor subunit is regulated differentially in the primate basal
ganglia following nigrostriatal dopamine denervation.
AB - Nigrostriatal dopaminergic denervation is associated with complex changes in the
functional and neurochemical anatomy of the basal ganglia. The excitatory
neurotransmitter glutamate mediates neural signaling at crucial points of this
circuitry, and glutamate receptors are differentially distributed in the basal
ganglia. Available evidence suggests that the glutamatergic corticostriatal and
subthalamofugal pathways become overactive after nigrostriatal dopamine
depletion. In this study, we have analyzed the regulation of the GluR1 subunit of
the a-amino-3-hydroxy-5-methyl-4-isoxazole propionate glutamate receptor in the
basal ganglia of primates following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
induced dopamine denervation. The dopamine denervation resulted in distinct
alterations in GluR1 distribution: (1) GluR1 protein expression was markedly
increased in caudate and putamen, and this was most pronounced in the striosomes;
(2) GluR1 protein was altered minimally in subthalamic nucleus; (3) expression of
GluR1 was down-regulated in the globus pallidus by 63% and in the substantia
nigra by 57%. The down-regulation of GluR1 expression in the output nuclei of the
basal ganglia, the internal segment of the globus pallidus and the substantia
nigra pars reticulata, may be a compensation for the overactive glutamatergic
input from subthalamic nucleus, which arises after striatal dopamine denervation.
Our results indicate that the glutamatergic system undergoes regulatory changes
in response to altered basal ganglia activity in a primate model of Parkinson's
disease. Targeted manipulation of the glutamatergic system may be a viable
approach to the symptomatic treatment of Parkinson's disease.
PMID- 10693950
TI - Neuroprotective mechanism of glial cell line-derived neurotrophic factor in
mesencephalic neurons.
AB - Glial cell line-derived neurotrophic factor (GDNF) provides neuroprotection, but
its neuroprotective mechanism has not been resolved. We investigated the
neuroprotective mechanism of GDNF using primary culture of the rat mesencephalon.
Bleomycin sulfate (BLM) and L-buthionine-[S,R]-sulfoximine (BSO) caused apoptosis
in both dopaminergic and nondopaminergic neurons, as revealed by the presence of
chromatin condensation, and positive staining by terminal deoxynucleotidyl
transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL). GDNF
preincubation blocked the neurotoxicity and reduced the number of the TUNEL
positive cells caused by BLM and BSO exposure. In contrast, GDNF did not provide
neuroprotection against glutamate toxicity, which was not accompanied by these
apoptotic features. The neuroprotection was mediated by phosphatidylinositol 3
kinase, an effector downstream from c-Ret, because it was blocked by LY294002.
GDNF pretreatment caused up-regulation of Bcl-2 and Bcl-x. Furthermore, GDNF
suppressed oxygen radical accumulation caused by BLM. Apoptosis induced by BLM
and BSO was blocked by a caspase-3 inhibitor. Caspase-3 activity was elevated by
BLM and suppressed by GDNF pretreatment. These findings indicate that GDNF has no
effect on necrosis but exerts protection against apoptosis by activation of
phosphatidylinositol 3-kinase and the subsequent up-regulation of Bcl-2 and Bcl
x, which suppresses accumulation of oxygen radicals followed by caspase-3
activation.
PMID- 10693951
TI - Reduction in TrkA-immunoreactive neurons is not associated with an overexpression
of galaninergic fibers within the nucleus basalis in Down's syndrome.
AB - Down's syndrome (DS) individuals develop neuropathological features similar to
Alzheimer's disease (AD), including degeneration of cholinergic basal forebrain
(CBF) neurons. In AD a reduction in CBF/trkA-containing neurons has been
suggested to trigger a hyperexpression of galaninergic fibers within the nucleus
basalis subfield of the basal forebrain. The present study examined the
interrelationship between reductions in CBF/trkA-containing neurons and the
overexpression of galaninergic fibers within the nucleus basalis in DS. Within
the nucleus basalis stereologic evaluation revealed a 46% reduction in the number
of trkA-immunopositive neurons, whereas optical density measurements displayed a
nonsignificant 18% reduction in neuronal trkA immunoreactivity in DS as compared
with age-matched controls. Western blot analysis also showed a significant
reduction in cortical trkA protein levels in DS. A semiquantitative examination
of galaninergic fibers in the nucleus basalis revealed only a modest hypertrophy
of galaninergic fibers within the nucleus basalis in DS. The present findings
indicate a significant reduction in trkA within the nucleus basalis and cortex
with only a moderate hypertrophy of galaninergic fibers in DS. These observations
suggest that DS may not be an exact genetic model for investigation of changes in
the AD basal forebrain.
PMID- 10693952
TI - C3-fullero-tris-methanodicarboxylic acid protects cerebellar granule cells from
apoptosis.
AB - Buckminsterfullerenols were recently investigated for their protective properties
in different models of acute and chronic neurodegeneration. We tested C3-fullero
tris-methanodicarboxylic acid in our in vitro model of apoptotic neuronal death,
which consists of shifting the culture K+ concentration from 25 to 5 mM for rat
cerebellar granule cells. The impairment of mitochondrial respiratory function as
well as chromatin derangement and fragmentation of DNA in apoptotic
oligonucleosomes that occur in these conditions were protected by this compound
in a concentration-dependent way. To assess whether antioxidant activity could
account for the rescue of cerebellar granule cells from apoptosis, we tested the
fullerene derivative under FeSO4-induced oxidative stress and found significant
protection. Thus, we visualized membrane and cytoplasmic peroxides and reactive
oxygen species and found a significant reduction of the species after 24 h in 5
mM K+ with the fullerene derivative. Such evidence suggests that this compound
exerts a protective role in cerebellar granule cell apoptosis, likely reducing
the oxidative stress.
PMID- 10693953
TI - Diminished glutathione levels cause spontaneous and mitochondria-mediated cell
death in neurons from trisomy 16 mice: a model of Down's syndrome.
AB - It has been suggested that the increased neuronal death in cultures from trisomy
16 (Ts16) mice, a model of Down's syndrome, might result from a diminished
concentration of reduced glutathione (GSH). In this study we used
microfluorometric techniques to investigate the effect of GSH levels on neuronal
survival in diploid and Ts16 cultures. Addition of the GSH precursors cysteine
and cystine and the antioxidant tocopherol to the culture medium increased the
GSH concentration up to 126.0% in diploid and up to 111.9% in Ts16 neurons.
Moreover, we observed a reduced spontaneous neuronal death rate in diploid and
Ts16 cultures. Following the application of 50-100 microM glutamate to culture
medium, we found a GSH increase in the presence of cysteine, cystine, tocopherol,
and cyclosporin A, an inhibitor of mitochondrial permeability transition
(diploid, 105.8-110.8%; Ts16, 83.1-96.3%). However, only tocopherol and
cyclosporin A had a protective effect on glutamate-induced neuronal death. The
results suggest that reduced GSH levels affect the increase of a spontaneous and
a mitochondria-mediated, cyclosporin A-sensitive type of neuronal cell death.
Therefore, elevating intracellular GSH concentration may have neuroprotective
effects in Down's syndrome and Alzheimer's disease.
PMID- 10693954
TI - Involvement of caspase-3-like protease in the mechanism of cell death following
focally evoked limbic seizures.
AB - The cysteine protease caspase-3 may be involved in the mechanism of cell death
following seizures. Using a rat model of focally evoked limbic epilepsy with
continuous electroencephalography monitoring, we investigated seizure-induced
changes in caspase-3 protein expression and processing, enzyme activity, and the
in vivo effect of caspase-3 inhibition. Seizures were induced by intraamygdaloid
injection of kainic acid (0.1 microg) and were terminated after 45 min by
diazepam (30 mg/kg) administration. Animals were killed 0-72 h following diazepam
administration. Levels of the 32-kDa proenzyme form of caspase-3 were unaffected
by seizures. Levels of the 17-kDa cleaved (active) fragment of caspase-3 were
almost undetectable in control brain, but were increased significantly at 4 and
24 h within ipsilateral hippocampus and cortex in seizure animals. Caspase-3-like
protease activity was increased within the ipsilateral hippocampus at 8 and 24 h
following seizures. Caspase-3 immunoreactivity was increased within the
vulnerable ipsilateral CA3/CA4 subfield at 24 and 72 h following seizures and was
associated predominantly, but not exclusively, with neurons exhibiting DNA
fragmentation. The putatively selective caspase-3 inhibitor N-benzyloxycarbonyl
Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethyl ketone significantly improved
neuronal survival bilaterally within the hippocampal CA3/CA4 subfields following
seizures. Collectively, these data suggest that caspase-3 may play a significant
role in the mechanism by which neurons die following seizures.
PMID- 10693955
TI - Early leptin response to a palatable diet predicts dietary obesity in rats: key
role of melanocortin-4 receptors in the ventromedial hypothalamic nucleus.
AB - We have investigated whether interactions between leptin and hypothalamic
melanocortin-4 receptors (MC4-Rs) determine individual susceptibility to dietary
obesity in rats. Animals with relatively high plasma leptin levels 1 week after
presentation of palatable food, before weight increased significantly,
subsequently showed lower food intake and weight gain after 8 weeks of palatable
feeding than those with low early leptin levels. The rats with lesser weight gain
also showed significantly greater down-regulation of MC4-Rs, which mediate
hypophagia, in specific hypothalamic areas, namely, the arcuate, dorsomedial, and
ventromedial (VMH) nuclei and the median eminence. We suggest that this reflects
enhanced receptor exposure to endogenous alpha-melanocyte-stimulating hormone, an
appetite-suppressing peptide produced by hypothalamic proopiomelanocortin
neurones. It is striking that plasma leptin levels at 1 week were inversely
correlated with MC4-R density in the VMH, suggesting that this is a key site of
leptin action. The early leptin response to palatable feeding may therefore
"program" subsequent feeding behaviour and weight gain by regulating neurones
that project selectively to the VMH.
PMID- 10693956
TI - L-DOPA does not enhance hydroxyl radical formation in the nigrostriatal dopamine
system of rats with a unilateral 6-hydroxydopamine lesion.
AB - The debate about the toxicity of L-DOPA to dopaminergic neurons has not been
resolved. Even though enzymatic and nonenzymatic metabolism of L-DOPA can produce
hydrogen peroxide and oxygen free radicals, there has been controversy as to
whether L-DOPA generates an oxidant stress in vivo. This study determined whether
acute or repeated administration of L-DOPA caused in vivo production of hydroxyl
radicals in striatum and other brain regions in rats with a unilateral 6
hydroxydopamine lesion of the dopaminergic nigrostriatal projections. Salicylate
trapping combined with in vivo microdialysis provided measurements of
extracellular 2,3-dihydroxybenzoic acid (2,3-DHBA) in striatum following L-DOPA
administration systemically (100 mg/kg, i.p.) or by intrastriatal perfusion (1
mM, via the microdialysis probe). Tissue concentrations of 2,3-DHBA and
salicylate were also measured in striatum, ventral midbrain, and cerebellum
following repeated administration of L-DOPA (50 mg/kg, i.p., once daily for 16
days). In each instance, treatment with L-DOPA did not increase 2,3-DHBA
concentrations, regardless of the nigrostriatal dopamine system's integrity. When
added to the microdialysis perfusion medium, L-DOPA resulted in a significant
decrease in the striatal extracellular concentration of 2,3-DHBA. These results
suggest that administration of L-DOPA, even at high doses, does not induce
hydroxyl radical formation in vivo and under some conditions may actually
diminish hydroxyl radical activity. Furthermore, prior damage to the
nigrostriatal dopamine system does not appear to predispose surviving
dopaminergic neurons to increased hydroxyl radical formation following L-DOPA
administration. Unlike L-DOPA, systemic administration of methamphetamine (10
mg/kg, s.c.) produced a significant increase in the concentration of 2,3-DHBA in
striatal dialysate, suggesting that increased formation of hydroxyl radicals may
contribute to methamphetamine neurotoxicity.
PMID- 10693957
TI - Functional expression of the serotonin transporter in immortalized rat brain
microvessel endothelial cells.
AB - There is evidence from recent studies that the brain endothelium (of capillaries
and/or larger vessels) may serve as a specific target for serotonin [5
hydroxytryptamine (5-HT)]. This neurotransmitter is expected to be involved in
the regulation of the blood-brain barrier (BBB) permeability and/or of the
cerebral blood flow via receptor-mediated mechanisms. Effective control of these
processes depends on a speedy uptake and metabolism of released 5-HT molecules.
To realize this, a similar mechanism of 5-HT uptake as in brain may exist at the
BBB. In this study, we have demonstrated using RT-PCR that 5-HT transporter mRNA
is present in the brain endothelium and that a saturable transport system for 5
HT is functionally expressed in immortalized rat brain endothelial cells (RBE4
cells). These cells take up [3H]5-HT by an active saturable process with a Km
value of 397 +/- 64 nmol/L and a transport capacity of 51.7 +/- 3.5 pmol x g(-1)
x min(-1). The 5-HT uptake depends on Na+, as indicated by the replacement of
NaCl by LiCl. The 5-HT uptake was sensitive to specific 5-HT transport inhibitors
such as paroxetine, clomipramine, fluoxetine, and citalopram but not to
inhibitors of the vesicular amine transporter such as reserpine or tetrabenazine.
Our results demonstrate that cerebral endothelial cells are able to participate
actively in the removal and metabolism of the released 5-HT, which supports the
concept of direct serotoninergic regulation of the BBB function.
PMID- 10693958
TI - ATP-sensitive potassium channel regulates astrocytic gap junction permeability by
a Ca2+-independent mechanism.
AB - Using the scrape-loading technique in cultured astrocytes, we show that
sulfonylureas such as tolbutamide and glybenzcyclamide, which inhibit the ATP
sensitive K+ channel, prevent the inhibition of gap junction permeability caused
by several structurally unrelated uncouplers such as oleic acid, arachidonic
acid, endothelin-1, octanol, and alpha-glycyrrhetinic acid. When the
intracellular level of Ca2+ was diminished, all the uncouplers tested were still
able to inhibit gap junction communication, indicating that their inhibitory
effect was not mediated by Ca2+. In addition, tolbutamide and glybenzcyclamide
prevented the inhibitory effect of these uncouplers in Ca(2+)-depleted
astrocytes, suggesting that the inhibition of the ATP-sensitive K+ channel
increases gap junction permeability through a Ca(2+)-independent mechanism. The
activation of the ATP-sensitive K+ channel caused by potassium channel openers
such as diazoxide and pinacidil led to the inhibition of gap junction
communication and overcame the effect of sulfonylureas. These results suggest
that the ATP-sensitive K+ channel regulates gap junctional permeability.
PMID- 10693959
TI - Effects of repeated antidepressant treatment of type 4A phosphodiesterase (PDE4A)
in rat brain.
AB - In a previous study, an up-regulation of rolipram-sensitive, low-Km, cyclic AMP
phosphodiesterase (PDE4) subtype PDE4A in rat cerebral cortex following repeated
treatment of desipramine was observed. To determine whether this effect is shared
by antidepressants from different pharmacological classes, PDE4A expression was
examined using immunoblot analyses following repeated treatment with the
norepinephrine re-uptake inhibitor desipramine, the monoamine oxidase inhibitor
phenelzine, the atypical antidepressant trazodone, and the serotonin reuptake
inhibitor fluoxetine. Desipramine, phenelzine, and fluoxetine all increased the
intensities of the PDE4A bands in hippocampal preparations; trazodone did not. In
preparations of cerebral cortex, the intensities of the PDE4A bands were
increased following desipramine treatment, not changed following phenelzine or
fluoxetine treatment, and decreased following trazodone treatment. It appears
that repeated treatment with antidepressant drugs from different pharmacological
classes produces similar effects on the expressions of PDE4A variants in
hippocampus. This effect is not correlated with the changes in beta-adrenergic
receptor densities, suggesting these antidepressants may at some point alter
intracellular signal transduction pathways in a similar manner.
PMID- 10693960
TI - Ascorbate inhibits edema in brain slices.
AB - Ascorbate is an essential antioxidant in the CNS, localized predominantly in
neuronal cytosol. Slices of mammalian brain rapidly lose ascorbate, however, when
incubated in ascorbate-free media; brain slices also take up water and swell.
Here we investigated water gain in coronal slices of rat forebrain incubated with
and without ascorbate for 1-3 h at 34 degrees C. Slices progressively gained
water in ascorbate-free media, with a significant 12% water increase after 3 h at
34 degrees C, compared with the water content of slices after a 1-h recovery
period at 24 degrees C, immediately following slice preparation. Inclusion of 400
micro M ascorbate in the medium led to an increase in tissue ascorbate content
and prevented water gain at 34 degrees C. By contrast, water gain was not
inhibited by isoascorbate or thiourea, which are antioxidants that are not
accumulated in brain cells. The oxidant H2O2 enhanced water gain, whereas a
cocktail of NMDA and non-NMDA receptor blockers inhibited edema formation to the
same extent as ascorbate. These data demonstrate that brain edema, linked to
glutamate-receptor activation, can result from intracellular oxidative stress and
that this can be prevented by ascorbate.
PMID- 10693961
TI - Differential control of tyrosine hydroxylase activation and catecholamine
secretion by voltage-operated Ca2+ channels in bovine chromaffin cells.
AB - Contributions of L-, N-, and P/Q-type voltage-operated Ca2+ channels to two
responses of bovine adrenal chromaffin cells have been studied using the
nonreceptor stimulus K+ depolarization. Tyrosine hydroxylase activity and
catecholamine secretion were both increased by K+ over a similar concentration
range and in a Ca(2+)-dependent manner. At a submaximal concentration of 20 mM
K+, tyrosine hydroxylase activation was reduced by nitrendipine but unaffected
individually by (+/-)-Bay K 8644, omega-conotoxin GVIA, omega-agatoxin IVA, and
omega-conotoxin MVIIC. It was fully blocked by combined inhibition of L-, N-, and
P/Q-type channels. With a maximal concentration of 50 mM K+, tyrosine hydroxylase
activation was unaffected by nitrendipine as well as by each of the other drugs
on its own; however, it was reduced by 71 % by combined inhibition of L-, N-, and
P/Q-type channels. In contrast, catecholamine secretion with both 20 and 50 mM K+
was enhanced by (+/-)-Bay K 8644, partially inhibited by nitrendipine and omega
conotoxin MVIIC, and completely blocked by a combination of antagonists for L-, N
, and P/Q-type channels. The results show that Ca2+ entry through voltage
operated Ca2+ channels can differentially regulate distinct chromaffin cell
responses and that this is an intrinsic property of the mechanisms by which Ca2+
entry activates these responses. It is not dependent on the parallel activation
of other signaling events by receptors.
PMID- 10693962
TI - Recombinant expression of alpha-bungarotoxin in Pichia pastoris facilitates
identification of mutant toxins engineered to recognize neuronal nicotinic
acetylcholine receptors.
AB - A snake venom-derived alpha-neurotoxin, alpha-bungarotoxin (alphaBgtx), is the
classic competitive antagonist of nicotinic acetylcholine receptors (nAChRs). The
very high specificity and essentially irreversible binding of alphaBgtx to
various nAChRs make alphaBgtx the prime candidate for studying the molecular
determinants of specificity for nAChR-ligand interactions. To facilitate site
directed mutagenesis of alphaBgtx for functional analysis, we have developed a
recombinant expression system for alphaBgtx using the methylotropic yeast Pichia
pastoris. A synthetic gene coding for alphaBgtx was subcloned into an expression
vector that directs secretion of the recombinant alphaBgtx (rBgtx) when stably
integrated into the yeast genome. Expression of rBgtx was induced by growth of
yeast cultures with methanol as the sole carbon source. The activity of the rBgtx
in the cell-free medium was measured by competition with 1251-Bgtx for binding to
Torpedo nAChR-enriched membranes. The rBgtx, purified to homogeneity by standard
HPLC, has the correct predicted amino terminal sequence and molecular mass. Its
circular dichroism spectrum is very similar to that of authentic venom-derived
alphaBgtx, and the biological activity of the rBgtx is identical to that of
authentic alphaBgtx. We have used the Pichia expression system to study a double
point mutation of alphaBgtx, rBgtx-K38P/L42Q, that has a high affinity for
alpha3beta2 neuronal nAChRs. This is the first demonstration of engineering an
alpha-neurotoxin to recognize non-alpha7 neuronal nicotinic receptors.
PMID- 10693963
TI - Altered G protein-coupling functions of RNA editing isoform and splicing variant
serotonin2C receptors.
AB - Different isoforms of serotonin subtype 2C receptor (5-HT(2C)R) with altered G
protein-coupling efficacy are generated by RNA editing, which converts
genomically encoded adenosine residues into inosines. In combination, editing of
five sites all located within the second intracellular loop region of 5-HT(2C)R
mRNA changes the gene-encoded Ile, Asn, and Ile at positions 156, 158, and 160,
respectively. We analyzed the G protein-coupling functions of previously
unreported editing isoform receptors. An approximately 13-fold reduction in the
agonist potency for G protein-coupling stimulation as well as a significantly
reduced basal level activity was observed with the thalamus-specific isoform
carrying Ile156, Gly158, and Val160 (5-HT(2C)R-IGV). In contrast, the agonist was
four- to five-fold less potent with 5-HT(2C)R-MSV and -IDV, detected in the
amygdala and choroid plexus, respectively, indicating a dominant role for the
amino acid residue at position 158 in receptor functions. We also identified a
splicing variant receptor with a truncated C terminus that displayed no ligand
binding capacity or G protein-coupling activity. Examination of the alternatively
spliced RNA encoding this truncated receptor suggests that editing of this
variant RNA occurs after completion of splicing, resulting in complete editing at
all five sites.
PMID- 10693964
TI - Immunolocalization of the mGluR1b splice variant of the metabotropic glutamate
receptor 1 at parallel fiber-Purkinje cell synapses in the rat cerebellar cortex.
AB - Several metabotropic glutamate receptor (mGluR) subtypes have been identified in
the cerebellar cortex that are targeted to different compartments in cerebellar
cells. In this study, preembedding immunocytochemical methods for electron
microscopy were used to investigate the subcellular distribution of the mGluR1b
splice variant in the rat cerebellar cortex. Dendritic spines of Purkinje cells
receiving parallel fiber synaptic terminals were immunoreactive for mGluR1b. With
a preembedding immunogold method, approximately 25% of the mGluR1b immunolabeling
was observed perisynaptically within 60 nm from the edge of the postsynaptic
densities. Values of extrasynaptic gold particles beyond the first 60 nm were
maintained at between 10 and 18% along the whole intracellular surface of the
dendritic spine membranes of Purkinje cells. For comparison, the distribution of
mGluR1a was studied. A predominant (approximately 37%) perisynaptic localization
of mGluR1a was seen in dendritic spines of Purkinje cells, dropping the
extrasynaptic labeling to 15% in the 60-120-nm bin from the edge of the
postsynaptic specialization. Our results reveal that mGluR1b and mGluR1a are
localized to the same subcellular compartments in Purkinje cells but that the
densities of the perisynaptic and extrasynaptic pools were different for both
isoforms. The compartmentalization of mGluR1b and mGluR1a might serve distinct
requirements in cerebellar neurotransmission.
PMID- 10693965
TI - Identification of amino acid residues of GABA(A) receptor subunits contributing
to the formation and affinity of the tert-butylbicyclophosphorothionate binding
site.
AB - A chimeric GABA(A) receptor subunit was constructed that contained the beta3
sequence from the N-terminus to the first two amino acids of the second
transmembrane (TM2) domain. The remaining part of this chimera had the sequence
of the alpha1 subunit. On co-expression with alpha1 subunits, this chimera was
able to form heterooligomeric channels that were open in the absence of GABA.
Picrotoxin and tert-butylbicyclophosphorothionate (TBPS) were able to block these
channels with low potency. These channels exhibited high-affinity [3H]muscimol
but no high-affinity [35S]TBPS binding sites. Introduction of V251, A252, and
L253 of the beta3 subunit into the chimera resulted in the formation of closed
channels that could be opened by GABA. The introduction of A252 and L253 of the
beta3 subunit into this chimera was sufficient to reconstitute the specific high
affinity [35S]TBPS binding site in receptors composed of the chimera and alpha1
subunits. Replacement of other amino acids of the TM2 region of the chimera with
corresponding amino acids of the beta3 subunit modulated the affinity of this
[35S]TBPS binding site. Results obtained provide important information on the
structure-function relationship of GABA(A) receptors.
PMID- 10693966
TI - Characterization of carrier-mediated efflux in human embryonic kidney 293 cells
stably expressing the rat serotonin transporter: a superfusion study.
AB - Human embryonic kidney 293 cells stably transfected with the rat plasmalemmal
serotonin transporter (rSERT) were incubated with 5-[3H]hydroxytryptamine ([3H]5
HT) and superfused. Substrates of the rSERT, such as p-chloroamphetamine (PCA) or
methylenedioxymethamphetamine, concentration-dependently increased basal efflux
of [3H]5-HT. 5-HT reuptake blockers (e.g., imipramine, citalopram) also caused an
enhancement of [3H]5-HT efflux, reaching about half the maximal effect of the
rSERT substrates. In uptake experiments, both groups of substances concentration
dependently inhibited 5-HT uptake. EC50 values obtained in superfusion
experiments significantly correlated with IC50 values from uptake studies (r2 =
0.92). Addition of the Na+,K(+)-ATPase inhibitor ouabain (100 microM) to or the
omission of K+ from the superfusion buffer accelerated basal efflux. The effect
of PCA (10 microM) was markedly enhanced by both measures, whereas the effect of
uptake inhibitors remained unchanged. When [3H]MPP+, a substrate with low
affinity for the rSERT, was used instead of [3H]5-HT for labeling the cells,
uptake inhibitors failed to augment efflux. By contrast, PCA accelerated [3H]MPP+
efflux, and its effect was strongly enhanced in the presence of ouabain. The
results suggest that the [3H]5-HT efflux caused by substrates of rSERT is carrier
mediated, whereas efflux induced by uptake inhibitors is a consequence of
interrupted high-affinity reuptake that is ongoing even under superfusion
conditions.
PMID- 10693967
TI - Angiotensin II modulates the activity of Na+,K+-ATPase in cultured rat astrocytes
via the AT1 receptor and protein kinase C-delta activation.
AB - In astrocytes the activity of the Na+,K(+)-ATPase pump maintains an inwardly
directed electrochemical sodium gradient used by the Na+-dependent transporters
and regulates the extracellular K+ concentration essential for neuronal
excitability. We show here that incubation of cultured rat astrocytes with
angiotensin II (Ang II) modulates Na+,K(+)-ATPase activity, in a dose- and time
dependent manner. Na+,K(+)-ATPase activation was mediated by binding of Ang II to
AT1 receptors as it was completely blocked by DuP 753, a specific AT1 receptor
subtype antagonist. Stimulation of Na+,K(+)-ATPase activity by Ang II was
dependent on protein kinase C (PKC) activation because PKC antagonists abolished
the inducing effect of Ang II and the PKC activator phorbol 12-myristate 13
acetate enhanced transporter activity. Ang II stimulated translocation of PKC
delta but not that of other PKC isoforms from the cytosol to the plasma membrane.
These results indicate that the activity of Na+,K(+)-ATPase in astrocytes is
increased by physiological concentrations of Ang II and that the AT1 receptor
subtype mediates the Na+,K(+)-ATPase response to Ang II via PKC-delta activation.
PMID- 10693968
TI - The organophosphate sarin, at low concentrations, inhibits the evoked release of
GABA in rat hippocampal slices.
AB - In the present study, the whole-cell mode of the patch-clamp technique was
applied to neurons of the CA1 pyramidal layer of rat hippocampal slices to
investigate the effects of the organophosphate (OP) sarin on field stimulation
evoked and on tetrodotoxin (TTX)-insensitive postsynaptic currents (PSCs)
mediated by activation of type A gamma-aminobutyric acid (GABA) receptors or AMPA
type glutamate receptors. At 0.3-1 nM, sarin reduced the amplitude of GABA
mediated PSCs and had no effect on the amplitude of glutamatergic PSCs evoked by
field stimulation of neurons synaptically connected to the neuron under study.
The effect of sarin on evoked GABAergic PSCs was unrelated to cholinesterase
inhibition, was partially reversed upon washing of the neurons with sarin-free
external solution, and was mediated by a direct interaction of the OP with
muscarinic acetylcholine receptors present on presynaptic GABAergic neurons.
Sarin had no effect on the amplitude or kinetics of GABA- or glutamate-mediated
miniature postsynaptic currents (MPSCs) recorded in the presence of the Na+
channel blocker TTX (300 nM), indicating that the OP does not interact with
GABA(A) or glutamate receptors. Further, sarin did not alter the frequency of
GABAergic or glutamatergic MPSCs, a finding that led to the conclusion that this
OP does not affect the TTX-insensitive release of neurotransmitters. A selective
reduction by sarin of the action potential-dependent release of GABA in the
hippocampus can account for the occurrence of seizures in intoxicated subjects.
PMID- 10693969
TI - Cisplatin-induced DNA-platination in experimental dorsal root ganglia
neuronopathy.
AB - The mechanism(s) and site(s) of the neurotoxic effect of cisplatin (CDDP) are
still not entirely elucidated. A more detailed knowledge of these aspects of CDDP
treatment might be useful to obtain a better understanding of the pathogenesis of
its peripheral neurotoxicity, which is the dose-limiting side effect of CDDP. In
the present study, the occurrence of CDDP-induced DNA-platination in dorsal root
ganglia (DRG) of rats was evaluated in relation to DRG neuron pathological
changes and CDDP-induced neuronopathy. Eight adult Wistar rats were treated with
2 mg/kg i.p. CDDP twice weekly for 9 times to induce sensory peripheral
neuropathy. DNA-platination in specimens of DRG and kidney was measured
immunohistochemically, with a polyclonal antibody (GPt) detecting CDDP-induced Pt
DNA adducts. Results were compared with those of untreated rats. Chronic CDDP
induced neurotoxicity, in a well described experimental model of chronic CDDP
neurotoxicity in the Wistar rat, was confirmed by sensory DRG neuronopathy with
secondary neuropathy, and demonstrated by reduced pain detection, decreased nerve
conduction velocity in the tail nerve as well as morphological and morphometric
changes in DRG neurons. Nuclear immunostaining for Pt-DNA adducts was observed in
tubular cells of the kidney in 75% of the evaluated CDDP-treated rats, while in
DRG cells CDDP-induced Pt-DNA adducts formation was found in 43% of the evaluated
CDDP-treated rats. CDDP-induced DNA-platination was demonstrated in rat DRG
neurons using a schedule of chronic CDDP administration which induced the onset
of a sensory neuronopathy with secondary peripheral neuropathy. This finding
further supports the hypothesis that CDDP is neurotoxic because it directly
damages the DRG neurons.
PMID- 10693970
TI - Neurotoxicity evaluation of rats after subchronic inhalation exposure to
isobutanol.
AB - The subchronic neurotoxic effects of isobutanol were studied by exposing Sprague
Dawley rats to isobutanol vapor concentrations of 0, 250, 1000, and 2500 ppm for
6 hrs/day, 5 days/wk, for 3 months. A comprehensive set of neurotoxicity tests
(functional observational battery, motor activity, perfusion fixation
neuropathology, and schedule-controlled operant behavior) including an assessment
of complex behavior dependent on learning and memory was conducted. In addition,
full histopathology and blood chemistry evaluations were conducted in order to
assess any potential functional/behavioral effects in the context of other
possible systemic toxicities. There were no morphological or behavioral effects
indicative of a specific, persistent or progressive effect of isobutanol on the
nervous system at exposure concentrations up to 2500 ppm. A slight decrease in
response to external stimuli was observed during exposures at all concentrations.
These effects are likely transient effects of acute exposure to isobutanol.
PMID- 10693971
TI - Increase in signal intensities on T1-weighted magnetic resonance images in
asymptomatic manganese-exposed workers.
AB - OBJECTIVES: To clarify the clinical significance of increased signal intensities
on T1 weighted magnetic resonance imaging (MRI) we performed a large-scale
epidemiological study on asymptomatic manganese (Mn)-exposed workers with its
focus on MRI. METHODS: We randomly selected 121 male workers out of a total of
750 workers including Mn-exposed, non-exposed manual, and non-exposed clerical
workers in the factories. We studied environmental and biological monitoring,
neurological examination, and MRI. RESULTS: The proportion of workers with
increased signal intensities among the exposed, the non-exposed manual workers,
and the non-exposed clerical workers was 46.1%, 18.8%, and 0%, respectively.
Especially, 73.5% of the welders showed increased signal intensities. In no
subject, were clinical signs of manganism observed. The pallidal index correlated
with blood Mn concentration. CONCLUSION: Increase in signal intensities on the T1
weighted image reflect recent exposure to Mn, but not necessarily manganism. At
which increase of signal intensity, the progression of manganism from Mn exposure
occurs, remains to be solved.
PMID- 10693972
TI - Brevetoxin modulates neuronal sodium channels in two cell lines derived from rat
brain.
AB - Single Na+ channel currents were recorded from cell-attached membrane patches
from two neuronal cell lines derived from rat brain, B50 and B104, and compared
before and after exposure of the cells to purified brevetoxin, PbTx-3. B50 and
B104 Na+ channels usually exhibited fast activation and inactivation as is
typical of TTX-sensitive Na+ channels. PbTx-3 modified channel gating in both
cell lines. PbTx-3 caused (1) significant increases in the frequency of channel
reopening, indicating a slowing of channel inactivation, (2) a change in the
voltage dependence of the channels, promoting channel opening during steady-state
voltage clamp of the membrane at voltages throughout the activation range of Na+
currents, but notably near the resting potential of these cells (-60 - -50 mV),
and (3) a significant, 6.7 mV hyperpolarized shift in the threshold potential for
channel opening. Na+ channel slope conductance did not change in PbTx-3-exposed
B50 and B104 neurons. These effects of Pbx-3 may cause hyperexcitability as well
as inhibitory effects in intact brain.
PMID- 10693973
TI - The effects of postweaning low-level Pb exposure on sustained attention: a study
of target densities, stimulus presentation rate, and stimulus predictability.
AB - It has been suggested that behavioral effects associated with low-level lead (Pb)
exposure are related to alterations in attentional processes. These "attention
deficits" remain undefined, and few studies have directly addressed the effects
of Pb on specific measures of attention. The current study assessed the impact of
Pb on sustained attention, as one of the 3 primary clinical symptom domains of
attention deficit disorder. Groups of rats were exposed from weaning (21 days of
age) to either 0, 50, or 150 ppm Pb acetate in drinking water producing blood Pb
levels of <5, 16.0, and 28.0 microg/dl, respectively. Rats were trained to
discriminate a pulsing (target) from a non-pulsing (distracter) light. Parametric
manipulations of target probability (10%-80%) and inter-stimulus interval (1 s-6
s, and variable) were imposed to evaluate whether effects of Pb were dependent
upon attention demand. Sensitivity of the paradigm to changes in CNS function was
validated by examining the effects of d-amphetamine (0.0-2.0 mg/kg) in a separate
group of rats. Exposure to 50 ppm increased errors of omission only during
sessions with long and variable inter-stimulus intervals. The 150 ppm group
showed a small increase in errors of commission during sessions with a long inter
stimulus interval. No other Pb-related effects were observed. The absence of any
pronounced Pb effects in this study on this sustained attention task could
indicate that: 1) any Pb-induced attention deficits are modified by reinforcement
and time-out contingencies; 2) Pb disrupts other aspects of attention such as
inability to tolerate delays or impulsivity; and 3) Pb-related deficits are due
to other behavioral dysfunctions.
PMID- 10693974
TI - Neurotoxicity of isoniazid and its metabolites in cultures of mouse dorsal root
ganglion neurons and hybrid neuronal cell line.
AB - Isoniazid (INH) is one of the anti-tuberculosis drugs widely prescribed for
patients since the early 1950s. It is relatively nontoxic but some patients
develop peripheral neuropathy attributed to a disturbance of vitamin B6
metabolism. Some isoniazid metabolites are hepatotoxic but little is known about
their neurotoxic property. Isoniazid and its metabolites including
acetylisoniazid, acetylhydrazine, diacetylhydrazine, isonicotinic acid and
hydrazine were examined for their potential neurotoxic effects in cultured mouse
dorsal root ganglion (DRG) neurons and mouse neuroblastoma x DRG neuron hybrid
cell line N18D3. Isoniazid did not cause neurotoxicity at exposures up to 7 days.
Hydrazine was found to be the most toxic metabolite with LC50 values of 2.7 mM
and 0.3 mM after 7 days of exposure in DRG neurons and N18D3 hybrid neurons,
respectively. Other metabolites including acetylisoniazid, acetylhydrazine,
diacetylhydrazine and isonicotinic acid had moderate to minor neurotoxic effects
on N18D3 hybrid neurons. Pyridoxine, which is used in clinical practice to
prevent or ameliorate the isoniazid-induced neuropathy, did not consistently
reverse the neurotoxicity of any of the metabolites in the cell cultures, but
some interaction with hydrazine cannot be ruled out. Pyridoxine itself was found
to be neurotoxic both in DRG neurons and N18D3 hybrid neurons, in agreement with
human peripheral sensory neuropathy caused by prolonged overdosage. The enzymes
catalase and superoxide dismutase and the antioxidant agent selenium showed some
protection against hydrazine neurotoxicity, suggesting an involvement of the
generation of reactive oxygen species in the pathogenesis of isoniazid
neuropathy. Both mouse DRG neurons and N18D3 mouse hybrid neurons were shown to
be useful culture systems for elucidating the neurotoxicity mechanisms of agents
causing sensory neuropathies and general neurotoxic effects in the nervous
system.
PMID- 10693975
TI - Tremor frequency patterns in mercury vapor exposure, compared with early
Parkinson's disease and essential tremor.
AB - A new portable tremometer allows determination of tremor intensities at different
tremor frequencies. Based on past studies, two tremor frequency windows of
similar size were chosen at 3.0-6.5 Hz and 6.6-10.0 Hz to reflect major tremor
intensities in Parkinson's disease and mercury vapor poisoning, respectively. In
81 healthy controls, total tremor intensity was higher for the preferred hand and
depended on age. Ten patients treated for Parkinson's disease showed
substantially increased tremor intensity, especially within the low-frequency
window. This pattern was also apparent in 14 patients with de novo Parkinson's
disease whose overall tremor intensity was only mildly elevated. In contrast, ten
patients with essential tremor had peak frequencies in both windows, and some
patients had increased tremor on one side only. Sixty-three Brazilian gold
traders exposed to mercury vapor showed increased tremor predominantly in the
high-frequency window. Three of the gold traders had a narrower tremor peak at
frequencies of 7-8 Hz. While the urine-mercury concentration was significantly
associated with the current number of burning sessions per week, it did not
correlate with tremor intensities. However, eight traders had a urinary mercury
excretion level above 50 microg and at the same time a greatly increased average
tremor intensity within the high-frequency window. These patterns were
statistically significant for relative tremor intensities, but were less clear
when total intensities were used. These observations suggest that the relative
distribution of tremor intensities in specific frequency bands may be a valuable
supplement to current diagnostic methods for subjects with mercury vapor
exposure.
PMID- 10693976
TI - Morphometric studies of myelination in the spinal cord of mice exposed
developmentally to aluminum.
AB - Swiss-Webster mice were exposed to diets containing 7 or 1000 microg aluminum
(Al)/g as Al lactate from conception through maturity (45 days of age). This
exposure has previously been shown to cause changes in CNS myelin composition and
peroxidizability; in this study myelin sheath widths were measured. Initially,
samples of epon embedded, toluidine blue stained cervical spinal cord sectioned
at 0.5 mm were examined light microscopically. Qualitatively, Al-treated mice
appeared to have a diffuse paleness in nerve tracts. No indication of myelin
structural damage (splitting, degeneration) was noted. Quantitative microscopy
was performed using images captured with Scion Image Dage 1.59 at 1000x with oil.
Axon perimeters and sheaths were measured with NIH image using a standardized
sampling pattern in the right medial dorsal and ventral regions of the cervical
spinal cord in 6 mice (3 male, 3 female) per group. Mean myelin sheath widths
were 16% smaller in the Al-treated group compared to controls (p=.03). There was
no effect of sex or region (dorsal/ventral). Axon perimeters were also smaller on
the average in the Al treated group but this difference was not significant
(p=.16). The relationship between sheath width and axon diameter was similar in
the two groups. The density of myelinated axons was greater in some areas for the
Al-treated group. The data indicate that dietary aluminum exposure can interfere
with myelination in the spinal cord.
PMID- 10693977
TI - Aluminum uptake and effects on transferrin mediated iron uptake in primary
cultures of rat neurons, astrocytes and oligodendrocytes.
AB - Transferrin (Tf) is known primarily for its role in the transport and cellular
uptake of iron (Fe). Tf is also the major serum binding protein for Al. In this
study, primary rat oligodendrocyte, neuron and astrocyte cultures were found to
differ in Tf mediated Fe and Al uptake and in the effect of Al-Tf on Fe-Tf uptake
during 4 h incubation periods. When incubated with Al-Tf (1.25 microM),
oligodendrocytes displayed a 3- to 4-fold increase (p=.0002) in Al, neurons
demonstrated a much smaller (p=.06) increase, and no increase was seen for
astrocytes. When incubated with equimolar Al citrate or Al chloride, no increase
in cellular Al was seen in any of the three cell types. Oligodendrocytes,
astrocytes and neurons all demonstrated greater 59Fe uptake from Fe-Tf than Fe
chloride. This uptake could be inhibited by excess Fe-Tf in oligodendrocytes and
neurons, but not astrocytes. A small but significant inhibition of 59Fe uptake
from Fe-Tf was seen after addition of Al-Tf to the incubation medium of
oligodendrocytes, but not neurons or astrocytes. Oligodendrocytes may be
particularly vulnerable to the accumulation of excess intracellular Al, and to
interference of Al with Fe uptake. Such effects could contribute to Al-induced
neurotoxicity if they result in altered myelin formation or maintenance.
PMID- 10693978
TI - Immunohistochemical study of phosphorylated neurofilaments during the evolution
of organophosphorus ester-induced delayed neuropathy (OPIDN).
AB - Organophosphorus ester-induced delayed neuropathy (OPIDN) is manifest by delayed
degeneration of distal levels of long myelinated fibers following an appropriate
neurotoxic exposure. We investigated the dynamics of cytoskeletal changes during
nerve fiber degeneration in this condition, focusing on the immunohistochemistry
of axonal phosphorylated neurofilaments. OPIDN was produced in 5-month-old White
Leghorn hens using a single 2.5 mg/kg intramuscular dose of phenyl saligenin
phosphate. Hens were sacrificed on days 4, 7, 9, 15, and 20, and the tibial nerve
branch to the gastrocnemius muscle was studied by light microscopy and
immunohistochemistry (using the SMI 31 monoclonal primary antibody to
phosphorylated neurofilaments). At post-dosing days 9, 15, and 20 various stages
of OPIDN lesions were noted, including axonal swelling and myelinated nerve fiber
degeneration. These were associated with intra-axonal cytoskeletal lysis,
manifest by loss of immunolabeled phosphorylated neurofilaments, a process
consistent with proteolysis. Aggregations of excess axonal phosphorylated
neurofilaments were not observed.
PMID- 10693979
TI - Dose response of ethanol ingestion on antioxidant defense system in rat brain
subcellular fractions.
AB - This study investigated the response of the antioxidant defense system in brain
subcellular fractions after oral graded doses of ethanol to rat. Four groups of
male Fischer-344 rats were orally administered saline, ethanol 2 g, 4 g, and 6
g/kg, respectively, and sacrificed 1 hour post treatment. Brain cytosol,
synaptosomes, microsomes and mitochondria were separated by density gradient
differential centrifugation and assayed for antioxidant system. A significant and
dose-dependent-decrease in superoxide dismutase (SOD) activity was observed in
all brain subcellular fractions. Catalase (CAT) activity was significantly
decreased in brain mitochondria (67% and 80% of control) at higher doses of
ethanol; whereas, CAT activity was significantly increased in cytosol,
synaptosomes and microsomes. Glutathione peroxidase (GSH-Px) activity was
significantly increased in all brain subcellular fractions except in cytosol at
higher dose of ethanol. Malondialdehyde (MDA) content was significantly increased
in all brain subcellular fractions showing dose response of ethanol-induced
oxidative stress. The increase in MDA levels in the brain synaptosomes and
microsomes were higher at 6 g dose of ethanol (155% and 163% of control) when
compared to mitochondria and cytosol. Glutathione (GSH) levels were significantly
increased in brain cytosol and microsomes at higher dose of ethanol (164% and
159% of control); whereas, the GSH concentration was significantly decreased in
brain synaptosomes and mitochondria. The antioxidant enzyme (AOE) activity ratios
(GSH-Px/SOD and GSH-Px + CAT/SOD) were dose dependently increased in all brain
subcellular fractions, particularly in synaptosomes. The GSH/GSSG ratio was dose
dependently increased in brain microsomes. The perturbations in the antioxidant
defense system and enhanced lipid peroxidation following graded doses of ethanol
ingestion indicate a dose-dependent-oxidative 2133stress response in brain
subcellular compartments of rats.
PMID- 10693980
TI - Minor immunophilin binding of tacrolimus and sirolimus metabolites.
AB - OBJECTIVES: We have previously identified three minor immunophilins of molecular
weights 37 kDa, 14 kDa, and 5-8 kDa capable of binding tacrolimus and sirolimus.
DESIGN AND METHODS: When tested against pure preparations of five sirolimus
metabolites, the 14 kDa protein had almost no cross-reactivity, the 37 kDa
protein cross-reacted from a high of 23.2% to <10% and the 5-8 kDa protein cross
reacted from <10% to 46.4%. When the 5-8 kDa immunophilin was tested in whole
blood samples to assess interference in clinical samples, the demethylated
sirolimus metabolites showed about 25% less cross-reactivity while the
hydroxylated metabolites reacted about the same. RESULTS: Since MLC data on
sirolimus metabolites to date indicates that their pharmacologic potencies are <
or =10% of the parent, the 14 kDa immunophilin appears to be the best candidate
for a sirolimus radioreceptor assay. The 5-8 kDa immunophilin is newly identified
and its cross-reactivity with tacrolimus metabolites had not been assessed.
Binding of the 5-8 kDa immunophilin to pure preparations of three tacrolimus
metabolites showed virtually no binding of the protein to 13-O-demethyl and 31-O
demethyl tacrolimus and binding to 15-O-demethyl tacrolimus at 121% relative to
parent tacrolimus. Cross-reactivity of 15-O-demethyl tacrolimus with the 5-8 kDa
protein was then assessed in whole blood samples, and it bound at a level of
163%. MLC data indicates that 31-O-demethyl tacrolimus is equipotent to parent
tacrolimus in immunosuppressive activity, while the 13-O-demethyl and 15-O
demethyl have negligible immunosuppressive activity. CONCLUSIONS: Therefore, the
5-8 kDa immunophilin would have limitations in a radioreceptor assay for
tacrolimus. In addition, we have evidence that the 5-8 kDa immunophilin is a
subunit of a 52 kDa immunophilin previously identified by our group, and the
cross-reactivity of the 5-8 kDa immunophilin with these metabolites is similar to
that found previously with the 52 kDa, indicating that the two proteins could be
related.
PMID- 10693981
TI - Enzyme immunoassay for the measurement of human tenascin-C on the Bayer Immuno 1
analyzer.
AB - OBJECTIVES: To evaluate a new tenascin-C assay performed on the Bayer Immuno 1
system. DESIGN AND METHODS: The precision was measured using three levels of
serum pools. Linearity was tested by diluting patient serum samples containing
high tenascin-C concentrations, and the minimal detectable concentration
determined by repetitive analysis of the zero calibrator. Preliminary reference
intervals were determined by testing serum samples from 220 healthy individuals.
Biovariability was estimated in a cohort of 20 apparently healthy subjects over
18 days. The levels of tenascin-C in patients with different liver diseases was
tested. RESULTS: The detection limit was 2 ng/mL. At concentrations ranging from
325 to 1957 ng/mL the assay demonstrated within-run and between-run CVs ranging
from 4% to 3.6% and 8.4% to 6.7%, respectively. Dilutions of sera were linear and
parallel to the standard curve with recoveries ranging from 97% to 100%. The
reference interval (central 95% interval) for tenascin-C in serum of healthy
adults was 199-906 ng/mL. The variability study yielded an analytical
variability, CV(A), of 1.8%; a within-subject variability, CV(I), of 11.7%; and a
between-subject variability, CV(G), of 39.3%. Tenascin-C concentrations in sera
of liver disease patients were significantly increased. CONCLUSIONS: The novel
assay provides a rapid and reliable procedure for the determination of tenascin-C
levels in human sera.
PMID- 10693982
TI - Laboratory standardization of a large international clinical trial: the DAIS
experience. DAIS Project Group. Diabetes Atherosclerosis Intervention Study.
AB - OBJECTIVE: To implement a quality control program for the standardization and
harmonization of lipid and lipoprotein analyses as performed at two core
laboratories (St. Paul's Hospital, UBC [Vancouver], and NPHI [Helsinki]) for the
Diabetes Atherosclerosis Intervention Study (DAIS). DESIGN AND METHODS: A
DAISSOFT computer program was designed to minimize the occurrence of data and
sample management errors during the course of the study. Fresh human serum was
used for the provision of an accuracy based external quality control program that
monitored the analytical performance of lipid testing at these two laboratories.
A separate program was designed for monitoring hemoglobin A1c (HbA1c). At the
outset of the study, allowable total error goals were established for each
analyte. Ongoing performance was monitored using bimonthly blinded challenges of
fresh human serum. The two EQA programs routinely monitored the analysis of total
cholesterol, calculated LDL-cholesterol, HDL-cholesterol, net triglycerides,
apoprotein A-1, apoprotein B, and HbA1c. RESULTS: The EQA precision and accuracy
data for the measurement of total cholesterol at the two core laboratories over
the last 5 years indicated both laboratories operated with good precision,
approximately 1% CV over the time period. The accuracy at both laboratories was
similar initially. Part way through the study, the accuracy of the cholesterol
method at NHPI tended to drift upward with an operating positive bias (+3%)
relative to the Abell Kendall reference method. Triglyceride measurements were
the most problematic for the study. By EQA cycle 8, the accuracy of the method at
UBC had stabilized and was meeting the accuracy goals of the study. NPHI's method
was negatively biased relative to the accuracy base of the DAIS study. In spite
of recalibrating their method, NPHI found it difficult to maintain consistent
accuracy for the measurement of triglycerides during the study. Both laboratories
operated their HDL methods with excellent precision. Accuracy at NHPI was well
maintained over the course of the study whereas the accuracy of HDL measurements
at UBC was more problematic. There was an inconsistent variation in the accuracy
of apoprotein A-1 measurements at both laboratories. In most cases, the bias
would be corrected by the time of the next EQA challenge. In the case of apo B,
one laboratory was standardized to the CDC while the other laboratory was
standardized to IFCC/WHO. The discrepancy between these two accuracy bases was
>20%. Recalibration to a common accuracy base rectified the problem. Only minor
problems were encountered with the precision and accuracy of the DIAMAT assay for
hemoglobin A-1c. The two DAIS core laboratories consistently operated within the
9% total error goals of the study for HbA1c. CONCLUSIONS: Through the use of this
program, the two DAIS core laboratories were able to maintain their lipid
analyses within the limits of allowable total error that had been established for
the study.
PMID- 10693983
TI - Nonenzymatic elimination of ascorbic acid in clinical samples.
AB - OBJECTIVES: Ascorbic acid interferes significantly in the oxidative reaction of
chromogenic reagents by peroxidase and hydrogen peroxide. Currently, ascorbate
oxidase is commonly utilized for eliminating the interference of ascorbic acid in
the oxidative colorimetric reaction. This enzyme, however, displays several
disadvantages, such as high cost, variation from lot to lot, and low stability.
We applied a series of commercially available and stable radicals (ascorbic acid
quenchers [AAQs]) for nonenzymatic quenching of ascorbic acid in the uricase
based uric acid determination in serum and urine. DESIGN AND METHODS: In order to
evaluate the quenching activity of AAQs, a commercially available uric acid
detection kit was used. TBA-80FR.NEO biochemical analyzer was utilized for the
assay. RESULTS: 4-Hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy free radical (AAQ
2) was the most effective ascorbic acid quencher among the four stable radicals,
and the uric acid assay suffered no interference by AAQ-2. The ascorbic acid
quenching ability of 2 mmol/L of AAQ-2 in reagent solution (reagent-I) was > or =
2 U/ml ascorbate oxidase in reagent solution. CONCLUSIONS: AAQ-2 was proven to be
a suitable quencher of ascorbic acid in clinical samples.
PMID- 10693984
TI - Comparison of steady-state trough sirolimus samples by HPLC and a radioreceptor
assay.
AB - OBJECTIVES: We have previously identified a minor immunophilin of 52 kDa
molecular weight capable of binding tacrolimus and sirolimus. Because
immunophilins are capable of binding both parent drug and metabolites and HPLC
assays are typically used to assess parent drug in clinical situations, we used
this immunophilin in a radioreceptor assay (RRA) to determine if any metabolites
not included in the HPLC measurement would bind to the immunophilin and be
associated with thrombocytopenia in patients receiving sirolimus. DESIGN AND
METHODS: We tested 51 steady-state trough whole blood samples from non
thrombocytopenic patients and 51 steady-state trough samples from
thrombocytopenic patients and compared them to HPLC measurements of parent drug
in the same samples. We also tested whole blood samples spiked with authentic
sirolimus metabolites using RRA to ascertain the effect these metabolites have on
the technique. RESULTS: We found minimal cross-reactivity in this assay for
sirolimus metabolites (binding ranged from <10% to 26%), and good correlation of
the radioreceptor assay with HPLC (linear regression slope 0.92, y-intercept
0.79). There was no statistically significant difference between the RRA and HPLC
results in two patient groups-thrombocytopenic and non-thrombocytopenic-using the
paired t-test (p<0.005) and Bland-Altman analysis. CONCLUSIONS: These findings
indicate that although the RRA could be substituted for HPLC in therapeutic drug
monitoring, the 52 kDa immunophilin does not offer an advantage in terms of
detecting metabolites associated with thrombocytopenia. However, the RRA offers
the advantages of shorter turnaround time, smaller sample volume and potential
for automation.
PMID- 10693985
TI - Plasma, urinary and fecal potassium changes in athletes during ambulatory,
periodic, and continuous hypokinetic conditions.
AB - OBJECTIVES: Prolonged hypokinesia (HK) induces significant electrolyte changes,
but little is known about the effect of prolonged periodic hypokinesia on plasma,
urinary, and fecal K. The aim of this study was to measure potassium (K) changes
during prolonged periodic (PHK) and continuous (CHK). DESIGN AND METHODS: Studies
were done during the pre HK and HK periods. Thirty male athletes were chosen as
subjects. They were divided equally into three groups: unrestricted ambulatory
control subjects (UACS), continuously hypokinetic subjects (CHKS), and
periodically hypokinetic subjects (PHKS). The CHKS group was kept on a running
distance of 0.7 km/day, while the PHKS group kept on a running distance of 0.7
and 11.7 km/day for 5 days and 2 days per week, respectively. The UACS group was
on a running distance of 11.7 km/day. RESULTS: The following were measured: fecal
K excretion; urinary K; sodium (Na) and chloride (CI) excretion; plasma K; Na and
CI concentration; plasma renin activity (PRA) and plasma aldosterone (PA)
concentration; physical characteristics; and peak oxygen uptake. Fecal K, urinary
K, Na and CI excretion, plasma K, Na and CI concentration, and PRA and PA
concentration, increased significantly (p< or =0.01) in the CHKS and PHKS groups
when compared with the UACS group. Body weight and VO2 peak decreased
significantly (p< or =0.01) in the CHKS group, while body weight increased and
VO2 peak decreased significantly (p< or =0.01) in the PHKS group when compared
with the UACS group. The measured parameters changed much more in the PHKS group
than in the CHKS group. By contrast, the measured parameters did not change
significantly in the UACS group when compared with the baseline control values.
CONCLUSION: It was shown that prolonged PHK and CHK induce significant plasma and
excretory K changes; however, plasma and excretory K changes were much greater in
the PHKS group than in the CHKS group. It was concluded that the greater the
stability of muscular activity, the smaller the plasma, urinary, and fecal K
changes during prolonged HK.
PMID- 10693986
TI - Serum 1,25 dihydroxy vitamin D (1,25(OH)2D3), 25 hydroxy vitamin D (25(OH)D) and
parathormone levels in diabetic retinopathy.
AB - OBJECTIVES: To investigate whether there is a relationship between serum 1,25
dihydroxy vitamin D3 [1,25(OH)2D3], which is an inhibitor of angiogenesis,
concentrations and severity of diabetic retinopathy (DR). DESIGN AND METHODS:
Serum 1,25(OH)2D3, 25 hydroxy vitamin D [25(OH)D] and parathormone (PTH)
concentrations were measured in diabetic patients (n = 66) and nondiabetic
healthy subjects (n = 20). RESULTS: The mean serum 1,25(OH)2D3 concentration in
diabetic patients was lower than that in nondiabetics (57.3+/-21.44 vs. 89.4+/
18.01 pmol/L, p<0.001); mean 1,25(OH)2D3 concentrations fell with increasing
severity of DR [being 63.4+/-17.26 pmol/L for background DR (BDR), 47.7+/-13.27
pmol/L for preproliferative DR (pre-PDR), and 43.1+/-19.45 pmol/L for
proliferative DR (PDR)]. Compared with the control group, serum 25(OH)D
concentrations were found to be decreased in diabetic patients (p<0.001). There
were negative correlations between 1,25(OH)2D3 and age (r = -0.331, p<0.01) and
duration of diabetes (r = -0.255, p<0.05). CONCLUSION: From these findings, it
was found that there was an inverse relationship between the severity of the
retinopathy, i.e., neovascularization, and serum 1,25(OH)2D3 concentrations,
being the lowest in PDR and the highest in diabetic patients without retinopathy
(NDR) patients. The measurement of serum 1,25(OH)2D3 concentrations might be
helpful to predict severity of DR in patients with diabetes mellitus.
PMID- 10693987
TI - p53 gene mutation, tumor p53 protein overexpression, and serum p53 autoantibody
generation in patients with breast cancer.
AB - OBJECTIVES: Autoantibodies against the p53 tumor suppressor protein have been
detected in the serum of a proportion of patients with various cancers. The
generation of such antibodies has been proposed to be due to either tumor p53
protein accumulation or to the type of p53 gene mutation. These hypotheses are
examined in the present study. DESIGN AND METHODS: Using immunofluorometric
assays, we studied 195 patients with primary breast cancer for the presence of
p53 antibodies in serum and p53 protein accumulation in the corresponding tumor.
Seventeen patients (9%) were p53 antibody-positive and 77 (40%) overexpressed
p53. Ten of the 17 p53 antibody-positive patients had tumor p53 accumulation and
7 were negative for p53. Statistical analysis revealed a weak association between
the presence of p53 antibodies and p53 protein accumulation (p = 0.05). Direct
DNA sequencing of exons 1-11 of the p53 gene was performed for 16 p53 antibody
positive and 16 p53 antibody-negative patients. RESULTS: Five of the seropositive
and eight of the seronegative patients had a p53 gene mutation. Four of the five
mutations in the p53 antibody-positive patients affected a Tyr residue, whereas
none of the gene abnormalities in the seronegative patients had such an effect.
CONCLUSIONS: We conclude that p53 antibodies tend to develop in patients with
tumor p53 accumulation, but p53 accumulation is neither sufficient nor necessary
for the generation of the immune response. Further, p53 antibody-positive
patients do not have higher frequency of p53 gene mutations than p53 antibody
negative patients, but the former patient group is associated with a Tyr
substitution in the protein product.
PMID- 10693988
TI - Assay of creatinine using the peroxidase activity of copper-creatinine complexes.
AB - OBJECTIVES: It was our goal to develop a urine dipstick that could measure
creatinine with a peroxidase reaction. The simultaneous measurement of albumin
and creatinine permits the estimation of the 24-h albumin excretion, an important
value in judging existing or likely development of renal failure. A highly
sensitive dye-binding dipstick method for albumin exists, and a suitable dipstick
for the assay for urine creatinine is described here. METHODS: Copper-creatinine
and iron-creatinine complexes have peroxidase activity. With 3,3',5,5'
tetramethylbenzidine (TMB), and diisopropyl benzene dihydroperoxide (DBDH); the
peroxidase activity of copper-creatinine and iron-creatinine complexes can be
demonstrated. This reaction was used in the assay of urine creatinine either in
solution or by a suitably impregnated urine dipstick. RESULTS: Our method based
on the peroxidase activity of the copper-creatinine complex has an analytical
range for creatinine of 100 mg/L (0.884 mmol/L) to 3000 mg/L (26.52 mmol/L). The
creatinine assay is free from most interfering compounds that may be present in
urine. Hemoglobin is an interferent, and its effects can be reduced but not
eliminated by the addition of 4-hydroxy-2-methyl quinoline. We do not recommend
using the dipsticks when visible blood is present or if the dipstick blood test
is positive. The copper-creatinine complex oxidizes ascorbic acid; however, we
were able to modify the reaction conditions so that ascorbic acid at < 4.4 g/L
does not interfere. We found good agreement on fresh urines between the
creatinine dipstick results and those by a standard rate-Jaffe cuvet method for
creatinine. DISCUSSION: With the simultaneous measurement of creatinine and
albumin in urine, the albumin/creatinine ratio can be determined effectively
reducing or eliminating the occasional false-negative and false-positive result
in those with dilute or concentrated urines, respectively. The dipstick test for
these analytes permits the simple identification of individuals with possible
albuminuria and could serve well in a point-of-care setting.
PMID- 10693989
TI - Correlation between susceptibility of LDL subfractions to in vitro oxidation and
in vivo oxidized LDL.
PMID- 10693990
TI - Reference interval of ferritin in premenopausal women calculated in four
laboratories using three different analyzers.
PMID- 10693991
TI - Alpha1-antitrypsin deficiencies masked by a clinical capillary electrophoresis
system (CZE 2000).
PMID- 10693992
TI - Superantigens, conventional antigens and the etiology of Kawasaki syndrome.
PMID- 10693993
TI - Bacteriologic and clinical efficacy of amoxicillin/clavulanate vs. azithromycin
in acute otitis media.
AB - OBJECTIVES: To compare the bacteriologic and clinical efficacy of
amoxicillin/clavulanate and azithromycin in patients with acute otitis media
(AOM), particularly the ability to eradicate the predominant AOM pathogens from
middle ear fluid as assessed by mandatory second tympanocentesis. METHODS: In
this single blind study 238 infants and children with AOM were randomized to
receive amoxicillin/clavulanate (45/6.4 mg/kg/day in two divided doses for 10
days) or azithromycin (10 mg/kg on Day 1, then 5 mg/kg daily on Days 2 through
5). Tympanocentesis was performed before the first dose and repeated on Day 4, 5
or 6. Clinical response was assessed at end of therapy between Days 12 and 14 and
at follow-up between Days 22 and 28. RESULTS: Amoxicillin/clavulanate was
significantly more likely to eradicate all bacterial pathogens [83% (54 of 65)
vs. 49% (35 of 71), P = 0.001] and Haemophilus influenzae [87% (26 of 30) vs. 39%
(13 of 33), P = 0.0001] from middle ear fluid than was azithromycin.
Amoxicillin/clavulanate was also more likely to eradicate Streptococcus
pneumoniae, but the difference was not statistically significant [90% (18 of 20)
vs. 68% (13 of 19) [corrected], P = 0.095]. On Days 12 to 14, signs and symptoms
were more likely to resolve completely or improve in all culture-positive
patients [86% (60 of 70) vs. 70% (51 of 73), P = 0.023] and in those with H.
influenzae infections [91% (30 of 33) vs. 65% (22 of 34), P = 0.010] who received
amoxicillin/clavulanate compared with those who received azithromycin. Otherwise
there were no significant differences between groups in clinical outcomes on Days
12 to 14 or at follow-up. CONCLUSIONS: Our findings indicate that
amoxicillin/clavulanate has superior bacteriologic and clinical efficacy compared
with azithromycin in children with AOM.
PMID- 10693994
TI - Testing for rubella-specific IgG antibody in urine.
AB - BACKGROUND: In Japan rubella vaccination is generally done once during a
lifetime, and the vaccination rate decreased after a revised vaccination law in
1995. History of rubella or vaccination may still be unreliable. Testing for
rubella antibody is significant to prevent the occurrence of congenital rubella
syndrome. However, the collection of blood samples to detect antibodies from
young children is invasive and difficult. METHODS: For this study we obtained 853
matched serum and urine samples from 904 healthy students 10 or 14 years of age
in the Ibara and Yoshii districts of Okayama, Japan, for a comparison of
antibodies for rubella in the matched samples. The serum and urine antibodies
were measured with hemagglutination-inhibition and enzyme-linked immunosorbent
assays, respectively, and with our urine-based antibody test. RESULTS: The
sensitivity, specificity and concordance rates of this urine-based antibody test
were 96, 99 and 97% based on the serum antibody results of both assays. The
coefficiency was 0.627 between the titers of the urinary and serum antibodies by
the enzyme-linked immunosorbent assay. The urinary antibodies were stable for at
least 5 months at 4 degrees C and 25 degrees C. CONCLUSIONS: Urine-based assay
methods are helpful not only because they avoid the invasive approach of
venipuncture but also because unprocessed urine specimens can be used and urinary
antibody is stable for a long period. Therefore this test is suitable for
screening. In addition protective amounts of rubella antibody in blood can be
reliably assessed by means of urine samples.
PMID- 10693995
TI - CD8+ T cell-mediated suppression of human immunodeficiency virus replication in
older children with acquired immunodeficiency syndrome.
AB - BACKGROUND: Suppression of HIV replication by CD8+ T cells and/or their products
correlated with the survival of infants. We sought to elucidate the role of CD8+
T cell-mediated suppression in seven older children with AIDS. METHODS: After
separation of each child's CD4+ and CD8+ T cells, three different HIV culture
assays were performed: (1) patient CD4+ T cells and phytohemagglutinin (PHA)
stimulated donor peripheral blood mononuclear cells (PBMC); (2) patient CD8+ T
cells added to the CD4+ T cells and the PHA-stimulated donor PBMC (to test for
CD8-mediated T cell suppression of HIV); (3) patient CD8+ cells added across a
semipermeable membrane to the CD4+ T cells and the PHA-stimulated donor PBMC [to
determine whether the CD8 cells secreted a soluble factor(s) that suppressed
HIV]. RESULTS: Cultures from four of seven children showed greater HIV
replication with CD4 cells alone than with CD4 and CD8 cells together,
demonstrating CD8 suppression; evidence of soluble suppression was also seen.
Cultures from two of the seven children showed HIV replication and no evidence of
CD8 cell suppression. Cultures from one of the seven children had no appreciable
replication of HIV even after removal of CD8 cells. CONCLUSIONS: CD8-mediated
suppression is present in at least some children with AIDS. Additional mechanisms
may be operating to slow the progression of the disease.
PMID- 10693996
TI - Nasal quantity of respiratory syncytical virus correlates with disease severity
in hospitalized infants.
AB - OBJECTIVE: To evaluate the relationship between nasal quantity of respiratory
syncytial virus (RSV) and disease severity in hospitalized infants without
underlying cardiopulmonary disease or immunodeficiency. METHODS: Nasal aspirates
were obtained from hospitalized infants <24 months of age with recently
identified RSV infection and evaluated for RSV quantity by a standard plaque
assay on HEp-2 cell monolayers. Subjects were classified as having "severe"
disease if they required mechanical ventilation at the time of sample collection
and as having "nonsevere" disease if they did not. Linear modeling was used to
determine the relationship between nasal RSV quantity and various independent
variables, including disease severity. RESULTS: Nasal aspirates from 39 patients
were evaluated. Age, gender and mean duration of time from symptom onset to
sample acquisition (5 days) were similar between the severe (n = 15) and
nonsevere (n = 24) groups. Significantly more infants were born at <35 weeks
gestation in the severe disease group (7 of 15 vs. 3 of 24, P = 0.017), and
infants born at <35 weeks gestation were significantly more likely to be of non
Caucasian ethnicity than were infants born at > or =35 weeks gestation (8 of 10
vs. 12 of 29, P = 0.035). The linear model found that higher nasal RSV quantities
were associated with severe disease [mean +/- SEM, 5.06 +/- 0.34 log plaque
forming units (pfu)/ml vs. 3.91 +/- 0.35 log pfu/ml, P = 0.022], gestational age
> or =35 weeks (5.44 +/- 0.27 log pfu/ml vs. 3.52 +/- 0.45 log pfu/ml, P = 0.002)
and non-Caucasian ethnicity (5.16 +/- 0.30 log pfu/ml vs. 3.80 +/- 0.37 log
pfu/ml, P = 0.006). CONCLUSIONS: Nasal RSV quantity correlates with disease
severity in hospitalized infants with recently identified RSV infection.
PMID- 10693997
TI - Immunoblotting and serology for diagnosis of Helicobacter pylori infection in
children.
AB - BACKGROUND: The easiest way to identify the presence of current or past
Helicobacter pylori infection is to test for antibodies. The aim of this study
was to compare an enzyme-linked immunosorbent assay (ELISA) technique based on
the detection of IgG antibodies directed against a global antigenic preparation
with immunoblotting based on the analysis of IgG antibody reactivity to separate
proteins. METHODS: Sera were collected from 80 children (mean age, 9.9 +/- 4.3
years). The reference tests were microbiologic and histologic examination of
gastric biopsies obtained at upper endoscopy. RESULTS: The immunoblotting was
more sensitive (100%) and specific (88%) than ELISA (96 and 79%, respectively) in
the evaluation of H. pylori infection in children. Its positive predictive value
was 92%, and its negative predictive value was 100%. The best performance index
of immunoreactive bands to detect antibodies was obtained with the 26-kDa
(88.7%), 30-kDa (77.5%) and 19.5-kDa (70%) antigens. Antibodies by immunoblot
technique against the CagA antigen were present in 43.1% of children. CONCLUSION:
Immunoblotting is highly sensitive and more specific than ELISA in children and
provides additional information about the full serologic profile. Immunoblotting
may therefore be a useful complement to serology, particularly in cases with
doubtful ELISA results.
PMID- 10693998
TI - Gram-negative bacillary bacteremia in human immunodeficiency virus type 1
infected children.
AB - BACKGROUND: HIV-infected children are particularly susceptible to serious
bacterial infections including Gram-negative bacillary bacteremia (GNB). However,
the information available on GNB in these children is limited. METHODS:
Retrospective review of hospital charts of HIV-infected children with GNB
diagnosed between 1980 and 1997. The association between bacteremic episodes,
degree of immunosuppression, HIV severity, medical treatment and clinical outcome
was assessed. RESULTS: Of 680 HIV-infected children, 72 (10.6%) had 95 episodes
of GNB. Statistical analyses were restricted to data from the first episode. The
mean age (+/-SD) at diagnosis of GNB was 2.5 +/- 2.7 years (median, 1.6). The
predominant organisms were Pseudomonas aeruginosa (26.4%), nontyphoidal
Salmonella (15.3%), Escherichia coli (15.3%) and Haemophilus influenzae (12.5%).
The relative frequency, per 5-year interval, of P. aeruginosa bacteremia steadily
increased from 13% during 1980 through 1984 to 56% during 1995 through 1997.
There were no cases of H. influenzae bacteremia after January 1, 1990. Eighty
percent of GNB developed in children with AIDS and 72.2% developed in those with
severe immunosuppression. Hypogamma-globulinemia and neutropenia were present in
only 4.9 and 10.4% of first episodes, respectively. The overall case-fatality
rate of GNB was 43.0%, and in children younger than 12 months it was 54.2%.
CONCLUSIONS: A diagnosis of AIDS and/or severe immunosuppression was associated
with increased risk of GNB, especially among younger children. Because of the
high mortality of GNB, a broad spectrum antimicrobial therapy that effectively
covers these organisms should be promptly instituted when bacteremia is suspected
in HIV-infected children.
PMID- 10693999
TI - Parents' preferences for outcomes associated with childhood vaccinations.
AB - BACKGROUND: The number of shots in the childhood immunization schedule has been
increasing and is likely to continue to increase in the coming years.
Consideration of the psychologic costs of multiple injections, adverse events and
vaccine-preventable disease is therefore growing in importance. METHODS: We
assessed parent preferences, using both the time tradeoff (i.e. amount of parent
time willing to trade) and willingness-to-pay (i.e. dollars willing to pay)
metrics, for possible outcomes of vaccination among 206 parents of infants
receiving care at Kaiser, Northern California Region. We also explored the
relationship between preferences and subject characteristics. RESULTS: In general
the amount of time subjects were willing to give up and the quantity of money
they were willing to spend to avoid an outcome increased with the severity of the
outcome. Preferences for our six main outcomes of interest all differed from one
another (P < 0.0001, Tukey's multiple comparisons procedure). Rank correlation
coefficients between time tradeoff and willingness-to-pay values for the six main
outcomes ranged from 0.42 to 0.52 (all P < 0.004). Subject characteristics,
including education, income, race/ethnicity and the child's birth order, did not
explain the variation in parent preferences. CONCLUSIONS: In general subjects
were willing to give up more money or time to avoid less desired outcomes. They
were willing to give up only very small amounts of their own life expectancy or
money to avoid minor, temporary outcomes (e.g. moderate fussiness, fever and
pain) whereas they were willing to forego substantial lengths of their life or
amounts of money to avoid a major, permanent outcome (i.e. permanent disability).
Nonetheless much variation surfaced in the amount of time (or money) subjects
were willing to trade to avoid outcomes. If this variation represents true
differences in preferences, guideline developers must consider the role of
individual parent preferences in decisions concerning vaccination.
PMID- 10694000
TI - Human antibodies to pneumococcal surface protein A in health and disease.
AB - BACKGROUND: Diseases caused by Streptococcus pneumoniae have a high impact in
young children whose ability to mount antibodies to capsular polysaccharides is
impaired. Pneumococcal surface protein A (PspA) is a potential vaccine candidate
for this age group. METHODS: We used Western blot analysis and enzyme immunoassay
to study human sera of healthy adults from Alabama (n = 20) and from Finland (n =
21), healthy children from Finland (n = 20) and ill children from Finland, those
with pneumococcal invasive infection (n = 26) and those with nonpneumococcal
invasive infection (n = 26). RESULTS: Human antibodies to PspA exhibited strong
cross-reactivity among different pneumococcal strains. The geometric mean titer
of IgG antibody to PspA in sera from 21 healthy adults was 4,040, from ten 3-year
old healthy children 1,080 and from ten 2-month-old healthy children 1,650. The
geometric mean titer of PspA antibody of acute phase sera of children with
invasive pneumococcal disease was 140, significantly (P < 0.001) lower than the
respective value, 1,020, for children with infection caused by other bacteria.
CONCLUSIONS: We demonstrate for the first time the existence of antibodies to
PspA in human sera in health and disease. The findings in ill children suggest
that antibodies to PspA might play a role in protection against pneumococcal
disease.
PMID- 10694001
TI - Prophylaxis for respiratory syncytial virus with respiratory syncytial virus
immunoglobulin intravenous among preterm infants of thirty-two weeks gestation
and less: reduction in incidence, severity of illness and cost.
AB - OBJECTIVE: To determine the impact of respiratory syncytial virus (RSV)
prophylaxis among preterm infants of < or =32 weeks gestation by comparing the
severity of illness and cost of RSV-related care during the two winter seasons
before (1994 to 1995, 1995 to 1996) with the two seasons after initiation of
prophylaxis (1996 to 1997, 1997 to 1998). METHODS: Preterm infants of < or =32
weeks gestation at risk for hospitalization with RSV infection were identified
retrospectively from the infants hospitalized in our neonatal units. Infants were
included if they (1) were born 6 months before or during four winter seasons
(1994 to 1998), (2) were discharged from the neonatal unit and (3) had remained
in the university outpatient clinic system during at least the first winter of
life. Preterm infants of < or =32 weeks gestation hospitalized with RSV were
identified from our RSV database (which includes cost of hospitalization,
duration of hospital stay, pediatric intensive care unit stay and intubation).
Infants receiving prophylaxis were identified prospectively. RESULTS: The
incidence of hospitalization with RSV was significantly lower among the cohort of
infants born after initiation of prophylaxis: 8.7% (17 of 195) vs. 22% (35 of
159), P = 0.00049 by two tailed Fisher's exact test. Among the cohort of infants
born after initiation of prophylaxis (n = 195), 100 infants received prophylaxis.
The gestational and chronologic ages of the prophylaxis-treated infants were
significantly lower than those of the non-prophylaxis-treated infants (n = 95).
The prophylaxis-treated infants also were more likely to have bronchopulmonary
dysplasia. Only 1 (1%) of the prophylaxis-treated infants required
hospitalization for RSV. Comparison of the cohort of infants born before
initiation of prophylaxis to the cohort born after initiation of prophylaxis
(includes prophylaxis-treated and non-prophylaxis-treated infants) revealed a
significant reduction in severity of illness and cost. The length of stay in the
cohort born before initiation of prophylaxis was reduced 83.8%: 373.6 days per
100 infants at risk vs. 60.5 (P = 0.00055). The length of stay in the pediatric
intensive care unit was reduced 92.7%: 218.2 days per 100 infants at risk vs.
15.9 (P = 0.00029). The duration of intubation was reduced 95.6%: 187.4 days per
100 infants at risk vs. 8.2 (P = 0.00024). The dollars spent for RSV-related care
(hospitalizations and prophylaxis) per 100 infants at risk for RSV was reduced
65% in the cohort of infants born after prophylaxis: $670,590 per 100 infants at
risk vs. $234,596 (P = 0.00056). This reduction remained significant (64.9%) if
the cost of ribavirin (drug and administration fees) was excluded from the cost
of hospitalization. CONCLUSIONS: These data reveal that RSV prophylaxis
significantly reduced the incidence of RSV hospitalizations and severity of
illness as well as the cost of RSV-related care among these infants.
PMID- 10694003
TI - Hyperbaric oxygen.
PMID- 10694002
TI - Safety and immunogenicity of three doses of a Neisseria meningitidis A + C
diphtheria conjugate vaccine in infants from Niger.
AB - BACKGROUND: High rates of endemic disease and recurrent epidemics of serogroup A
and C meningococcal meningitis continue to occur in sub-Saharan Africa. A
meningococcal A + C polysaccharide diphtheria-toxoid-conjugated vaccine may
address this issue. METHODS: In Niger three doses of a bivalent meningococcal A +
C diphtheria-toxoid-conjugated vaccine (MenD), containing 1, 4 or 16 microg of
each polysaccharide per dose, administered at 6, 10 and 14 weeks of age, were
compared with Haemophilus influenzae type b-tetanus toxoid-conjugated (PRP-T)
vaccine given with the same schedule or with a meningococcal A + C polysaccharide
vaccine (MenPS) given at 10 and 14 weeks of age. One blood sample was taken at
the time of enrollment (6 weeks of age) and another was taken 4 weeks after the
primary series. RESULTS: All doses of MenD were well-tolerated. After the primary
series a higher proportion of infants had detectable serum bactericidal activity
against serogroup A for each dose of MenD (from 94% to 100%) than for MenPS (31%)
or H. influenzae type b-tetanus toxoid-conjugated vaccine (18.9%); P < or = 0.05.
Significant differences were also observed for serogroup C MenD 4 microg or MenD
16 microg (100%) vs. MenPS (69.7%) or Haemophilus influenzae type b-tetanus
toxoid-conjugated vaccine (24.3%); P < or = 0.05. When MenPS vaccine was given to
11-month-old children, the immune response measured by both enzyme-linked
immunosorbent assay and serum bactericidal assay was greater in those previously
immunized with MenD than in those immunized with MenPS vaccine. CONCLUSION: MenD
was safe among infants in Niger, and immunization led to significantly greater
functional antibody activity than with MenPS. The 4-microg dose of MenD for both
the A and C serogroups has been selected for further studies.
PMID- 10694004
TI - The relationship between infection with group A beta hemolytic streptococci and
the development of psoriasis.
PMID- 10694005
TI - Cokeromyces recurvatus as a human pathogenic fungus: case report and critical
review of the published literature.
PMID- 10694006
TI - Endocarditis caused by Corynebacterium diphtheriae: case report and review of the
literature.
PMID- 10694007
TI - Respiratory coronavirus infections in children younger than two years of age.
PMID- 10694008
TI - Neonatal septicemia caused by Vibrio cholerae O:139.
PMID- 10694009
TI - Mefloquine-induced psychosis.
PMID- 10694010
TI - Donovanosis causing cervical lymphadenopathy in a five-month-old boy.
PMID- 10694011
TI - Herpes zoster in healthy children immunized with varicella vaccine.
PMID- 10694012
TI - Severe ehrlichiosis in an adolescent taking trimethoprim-sulfamethoxazole.
PMID- 10694013
TI - Severe rhabdomyolysis, hyperthermia and shock after amphotericin B colloidal
dispersion in an allogeneic bone marrow transplant recipient.
PMID- 10694014
TI - Human monocytic ehrlichiosis in a child with leukemia.
PMID- 10694015
TI - Eleven-month-old with recurrent bacterial and aseptic meningitis.
PMID- 10694016
TI - Serum alpha-tocopherol and beta-carotene levels are not associated with rheumatic
fever in Bangladeshi children.
PMID- 10694017
TI - Sibling history of recurrent acute otitis media correlates with low IgG2 anti
pneumococcal polysaccharide antibody levels.
PMID- 10694018
TI - Whither penicillin? A response to the question.
PMID- 10694019
TI - Rubella immunity in young women.
PMID- 10694020
TI - Operative repair of the fixed hammertoe deformity.
AB - Sixty-three patients (118 toes) were evaluated at an average 61 month follow-up
following PIP resection arthroplasty for a fixed hammertoe deformity. The
deformity involved the second toe in 35%, the third toe in 21%, the fourth toe in
24%, and the fifth toe in 20%. The involved toe averaged 2 mm. greater length
than the adjacent toes and was longer in 49/94 (52%). Seventy-eight percent of
patients complained of pain preoperatively due to the hammertoe deformity and 49%
complained of callus formation. Following a resection arthroplasty technique with
intramedullary Kirschner wire fixation, fusion of the PIP joint occurred in 81%
of toes. A fibrous union resulted in the remaining 19% of cases. Patients rated
subjective alignment as acceptable in 86% of cases and radiographic alignment was
rated as good in 79%. Malalignment and numbness were the major factors associated
with an unsuccessful result. Pain was relieved in 92%of patients and subjective
satisfaction was noted by 84% of patients. Minor complications occurred in 5%.
The average postoperative AOFAS score was 83 points. Resection arthroplasty of
the proximal interphalangeal joint with intramedullary Kirschner wire fixation as
a technique for correction of a fixed hammertoe deformity is a reliable technique
that consistently gives a high level of satisfactory results.
PMID- 10694021
TI - Sinus tarsi approach with trans-articular fixation for displaced intra-articular
fractures of the calcaneus.
AB - The charts and radiographs of 99 patients with 106 intraarticular fractures of
the calcaneus were retrospectively reviewed. There were 75 men and 24 women. The
average age was forty-two (range, 17 to 81). Fifty-seven of the fractures were
left and 49 were right. The mechanism of injury was a fall from a height in 69
patients and motor vehicle accident in 30 patients. According to Sanders
classification, seventy-one cases (67%) had type II fractures, 25 cases (23.6%)
had type III, and ten cases (9.4%) had type IV. All the patients had operative
management through a limited sinus tarsi approach with minimal fixation of the
fracture with one or several pins. One of the pins was usually applied from the
talus to the calcaneus through the fracture after reduction of the posterior
facet. Nine cases (8.5%) developed postoperative infection, four cases (3.8%) had
superficial wound infection, four cases (3.8%) had pin tract infection and one
case (0.9%) had osteomylitis. Our follow-up at an average of 29 months (range, 12
to 84 months) showed that the American Orthopedic Foot and Ankle Society, Ankle
Hindfoot Score for the all group was 77.6 (range, 31-91). Forty-one fractures
(38.8%) were graded excellent, 39 fractures (36.7%) good, 14 fractures (13.2%)
fair, and 12 fractures (11.3%) were failures. Although radiological degenerative
changes in the subtalar joint were seen in 41 cases (38.7%), only six cases
(5.6%) required subsequent subtalar fusion. The authors conclude that the
operative method used in the current study which followed the principle of
minimal soft tissue damage and minimal internal fixation may be a good option for
management of calcaneus fractures.
PMID- 10694022
TI - Internal architecture of the calcaneus: implications for calcaneus fractures.
AB - STUDY DESIGN: Fourteen cadaveri specimens were sectioned to analyze the internal
architecture of the human calcaneus. We described the arrangement and orientation
of trabecular patterns within the calcaneus and made multiple measurements of its
cortical thickness. OBJECTIVE: To characterize the internal architecture of the
calcaneus and correlate these findings with well-described patterns of calcaneus
fracture in order to better understand the fracture mechanics of this common
fracture. METHODS: Fourteen dry, frozen, human calcanei were sectioned using a
saw. In each the coronal, sagittal and axial planes, we sectioned separate
specimens into slices of 0.5 mm thickness. High-resolution radiographic images
were taken of the sectioned specimens. The internal trabecular arrays were
described and measurements of cortical thickness were recorded. The correlation
between these findings and the known pattern of calcaneal fractures was analyzed.
RESULTS: A dominant trabecular pattern running antero-posteriorly along the long
axis of the calcaneus was observed. In the posterior tuberosity the trabeculae
were arranged parallel to the posterior border. There was an area of sparse or
absent mineralization in the anterior part of the calcaneus corresponding to the
"neutral triangle" described by Wood and Harty 10, 23. The thickest sites of the
calcaneal cortex were the lower pole of the posterior tuberosity, the upper
surface at the angle of Gissane, and the lateral surface below the anterior
portion of the posterior facet. CONCLUSION: The trabecular architecture of the
calcaneus is created by applied stress in concordance with Wolff's law. The
weakest plane of resistance to stress is parallel to these organized trabeculae
or through areas lacking trabeculae. This study demonstrates that the primary and
secondary fracture lines commonly encountered in calcaneus fractures correlates
with the internal architectural map of the calcaneal trabecular patterns.
PMID- 10694023
TI - Treatment strategies in osteochondral defects of the talar dome: a systematic
review.
AB - The aim of this study was to investigate the results of different treatment
strategies for osteochondral defects (OCD) of the talus. Electronic databases
from 1966 to July 1998 were systematically screened. Based on our inclusion
criteria 32 studies describing the results of treatment strategies for OCD of the
talus were included. No randomized clinical trials (RCT's) were identified.
Fourteen studies described the results of excision alone, 11 the results of (EC),
14 the results of (ECD), 1 the results of cancellous bone grafting after EC, 1
the results of osteochondral transplantation and 3 the results of fixation. The
average success rate of non-operative treatment (NT) was 45%. Comparison of
different surgical procedures shows that the average highest success rate was
reached by excision, curettage and drilling (ECD) (85%) followed by excision and
curettage (EC) (78%) and excision alone (38%). Based on this systematic review we
conclude that NT and excision alone are not to be recommended in treating talar
OCD. Both EC and ECD have been shown to lead to a high percentage good/excellent
results. However, due to great diversity in the articles and variability in
treatment results, no definitive conclusions can be drawn. Further prospective
randomized controlled trials are required to compare the outcome of these two
surgical strategies for OCD of the talus.
PMID- 10694024
TI - Follow-up study of MRI for osteochondral lesion of the talus.
AB - Characteristic MRI findings of osteochondral lesions of the talus have been
reported. We examined how they change before and after treatment and discussed
their significance. Twenty two ankles in 21 patients had MRI examination before
and after treatment of the talar lesion. We evaluated the changes in the low
intensity areas in T1-weighted image and the signal rims behind osteochondral
fragment in T2-weighted image which have been reported as characteristic
findings. Clinical symptoms were improved postoperatively in all subjects. The
low intensity areas in T1-weighted image seen before the surgical treatment
tended to decrease in size postoperatively. The low intensity area in T1-weighted
image was reduced in 15 of the 22 ankles (68.2%). Low signal rim in T2-weighted
image was seen in three cases before the treatment. All disappeared completely
after arthroscopic drilling. Similarly, high signal rim in T2-weighted image seen
in 13 cases before the treatment disappeared in 10 postoperatively. These
findings were considered indicative that surgical treatments reduced abnormal
stress of the underlying bone element due to unstable osteochondral fragment,
leading to reduction of the low intensity area. The disappearance of signal rims
in T2-weighted images was considered to indicate obliteration of the interface
between the osteochondral fragment and the talar bed with bone union. We believe
that MRI of the osteochondral lesion of the talus will be useful for
postoperative evaluation allowing assessment of the need for further treatment.
The decreasing size of low intensity areas in T1-weighted images and
disappearance of signal rims behind the osteochondral fragment in T2-weighted
images suggested healing of the osteochondral lesions.
PMID- 10694025
TI - Transient osteoporosis of the talus.
AB - Transient osteoporosis is a clinical syndrome of unknown etiology characterized
by the acute onset of pain gradually worsening over several weeks to months.
Radiographic changes occur, but laboratory studies are generally unremarkable.
Transient osteoporosis of the talus appears to have a similar clinical
appearance, radiographic findings, and successful response to conservative
management as transient osteoporosis found elsewhere in the body and can be
treated similarly. Awareness of this syndrome is important to avoid confusing it
with a variety of other disorders of the talus that may have similar clinical
presentations.
PMID- 10694026
TI - Ankle biomechanics during impact landings on uneven surfaces.
AB - Inversion sprains of the lateral ligaments of the ankle are one of the most
common of all sporting injuries. While the strains in the anterior talofibular
(ATFL) and calcaneofibular (CFL) ligaments have been measured in quasi-static
conditions, the dynamic strains during an actual traumatic event have not been
determined. The present investigation determined the strains and strain rates in
the ATFL and CFL during an in vitro inversion sprain. The ATFL tended to have
higher strain and strain rate values than the CFL, which may explain why it is
more often injured than the CFL.
PMID- 10694027
TI - Periosteal chondroma of the cuboid presenting in a 7-year-old-boy.
AB - This case report discusses the finding of a periosteal (juxtacortical) chondroma
of the cuboid in a 7-year-old male. While this lesion is well recognized in the
tubular bones of adults, this case is unusual due to the child's age, the site of
the lesion (cuboid), and the difficulty in establishing the diagnosis due to the
cellular atypia. The child was treated with marginal resection and curettage with
no evidence of local recurrence on follow-up. A review of the literature is also
included in the discussion.
PMID- 10694028
TI - Isolated medial cuneiform fracture: review of the literature and report of two
cases.
AB - The authors present two unusual cases of isolated medial cuneiform fracture. Both
fractures were difficult to see on plain films and therefore diagnosed with
ancillary tests (computed tomography and magnetic resonance imaging). Treatment
was nonweightbearing cast immobilization, in which both patients healed within
twelve weeks of treatment without complication and returned to full work related
activities.
PMID- 10694029
TI - Modification of the Chrisman-Snook technique.
PMID- 10694030
TI - Intermediate to long term follow-up of medial approach dorsal cheilectomy for
hallux rigidus.
PMID- 10694031
TI - Dorsiflexion metatarsal osteotomy for treatment of recalcitrant diabetic
neuropathic ulcers.
PMID- 10694032
TI - Dorsiflexion metatarsal osteotomy for treatment of recalcitrant diabetic
neuropathic ulcers.
PMID- 10694033
TI - External rotation-lateral view of the ankle in the assessment of the posterior
malleolus.
PMID- 10694034
TI - Superoxide and hydroxyl radical generation, and superoxide dismutase in PSII
membrane fragments from wheat.
AB - Illumination of photosystem II (PSII) membrane fragments of wheat (Triticum durum
Desf. cv. Adamello) gave rise to both O2*- and *OH radicals adducts of the novel
spin trap 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO). With
time, *OH became predominant displaying the conversion of O2*- into *OH. An
intrinsic activity of superoxide dismutase (SOD) was found in PSII.
Photoreduction of nitroblue tetrazolium (NBT) by PSII membrane fragments was
induced by the addition of sodium azide and hydrogen peroxide. Western blotting
of PSII proteins showed that a 29 kDa protein was recognised by an antibody
against chloroplastic Fe-SOD from water lily. An increased formation rate of O2*-
was observed in damaged PSII where the SOD activity decreased following a
treatment with a free radical-generating system. Damage in PSII consisted also in
a decrease in chlorophyll and in carotenoids as well as in a change in the lipid
: chlorophyll : protein ratio. Upon treatment a decrease in the unsaturation of
PSII membrane fragments was also monitored together with a degradation towards
more saturated molecular species of monogalactosyldiacylglycerol.
PMID- 10694035
TI - Differential response of antioxidative enzymes of chloroplasts and mitochondria
to long-term NaCl stress of pea plants.
AB - In this work the activity of superoxide dismutase (SOD) and the enzymes of the
ascorbate-glutathione (ASC-GSH) cycle were investigated in chloroplasts and
mitochondria from leaves of Pisum sativum L. cv. Puget after 15 days treatment
with 0-130 mM NaCl. The main chloroplastic SOD activity was due to CuZn-SOD II,
which was increased significantly (about 1.7-fold) by NaCl, although during
severe NaCl stress (110-130 mM) chloroplastic Fe-SOD exhibited a stronger
enhancement in its activity (about 3.5-fold). A sudden induction in chloroplastic
APX, DHAR and GR was also caused by NaCl (70-110 mM), but not by the highest salt
concentration (130 mM), at which GR and DHAR activities were similar to the
control values and APX decreased. In addition, the H2O2 concentration and lipid
peroxidation of membranes increased significantly, 3.5- and 7-fold, respectively,
in chloroplasts under severe NaCl stress. In purified mitochondria DHAR and GR
were significantly induced only at 90 and 130 mM NaCl, respectively, although
DHAR activity was below control values in the highest NaCl concentrations. APX
and MDHAR activities started their response to salt in mild NaCl conditions (70
mM) and increased significantly with the severity of the stress. Mn-SOD was
induced only under severe NaCl concentrations. The mitochondrial H2O2 and lipid
peroxidation were increased at the highest NaCl concentration although to a
lesser extent (about 2-2.5-fold) than in chloroplasts, whereas the increase in
carbonyl protein contents was higher in mitochondria. The results suggest that
the degree of enhanced tolerance to NaCl seems to require the induction of
specific isoforms, depending on the different organelles.
PMID- 10694036
TI - Ozone detoxification in the mesophyll cell wall during a simulated oxidative
burst.
AB - With the aim to assess the effect of possible O2*- generation during an oxidative
burst on O3 reduction in mesophyll cell walls due to the reaction O2*- + O3 -->
O3*- + O2 and subsequent formation of *OH, 03 flow through this sequence was
compared with O2*- flow through the competitive sequences where H2O2 is formed.
The two-electron reduction of O3 via the direct reaction with ascorbate was also
considered. The calculations were exemplified in an experiment where Phaseolus
vulgaris L. leaves were exposed to 530 nl O3 l(-1) in air for 3.5 h. During the
exposure, H2O2 was assumed to be generated at peak rates observed in pathogen
elicited cell suspensions. O3 reduction through reaction with O2*- was 25-44% of
O3 detoxified in the direct reaction with ascorbate. More than 99% of O2*- was
reduced to H2O2 via spontaneous disproportionation and reduction with ascorbate,
the disproportionation prevailing at pH 5 and reduction at the expense of
ascorbate at pH 7. H2O2 was estimated to be channelled mostly to the peroxidase
catalysed scavenging reaction. Calculated steady state H2O2 concentrations were
40-80 microM. It is concluded that generation of H2O2 at the postulated rate was
too high and that the generation of O2*- during an oxidative burst is ineffective
in reducing O3 through the network of reactive oxygen species. Superoxide
dismutase induction in the cell wall under O3 is discussed.
PMID- 10694037
TI - Cadmium toxicity and oxidative metabolism of pea leaf peroxisomes.
AB - The effect of growing pea plants with 50 microM CdCl2 on the activated oxygen
metabolism was studied at subcellular level in peroxisomes isolated from pea
leaves. Cadmium treatment produced proliferation of peroxisomes as well as an
increase in the content of H2O2 in peroxisomes from pea leaves, but in
peroxisomal membranes no significant effect on the NADH-dependent O2*- production
was observed. The rate of lipid peroxidation of membranes was slightly decreased
in peroxisomes from Cd-treated plants. This could be due to the Cd-induced
increase in the activity of some antioxidative enzymes involved in H2O2 removal,
mainly ascorbate peroxidase and glutathione reductase, as well as the NADP
dependent dehydrogenases present in these organelles. The activity of xanthine
oxidase did not experiment changes by Cd treatment and this suggests that O2*-
production in the peroxisomal matrix is not involved in Cd toxicity. This was
supported by the absence of changes in plants treated with Cd in the Mn-SOD
activity, responsible for O2*- removal in the peroxisomal matrix. Results
obtained indicate that toxic Cd levels induce imbalances in the activated oxygen
metabolism of pea leaf peroxisomes, but its main effect is an enhancement of the
H2O2 concentration of these organelles. Peroxisomes respond to Cd toxicity by
increasing the activity of antioxidative enzymes involved in the ascorbate
glutathione cycle and the NADP-dependent dehydrogenases located in these
organelles.
PMID- 10694038
TI - Cd-induced oxidative burst in tobacco BY2 cells: time course, subcellular
location and antioxidant response.
AB - The relation between Cd and oxidative stress in BY2 cell cultures of tobacco was
studied. In response to 5 mM Cd, a rapid generation of H2O2 has been detected in
tobacco cell cultures by the oxidative quenching of the fluorescent reporter dye
pyranine. This oxidative burst reached the maximum production of H2O2 after 10
min of treatment with Cd. This response could be considered as short term
hypersensitive response previous to the oxidative stress caused by the metal at
the cell plasma membrane. The observed antioxidant enzymatic response to the
oxidative burst was preceded by an increased peroxidation of lipids with a
significant increase in the activities of superoxide dismutase and ascorbate
peroxidase. The results presented in this study point out to the plasma membrane
as the primary target for the short term production of activated oxygen species
in response to Cd in BY2 tobacco cells followed by a coordinated activation of
the antioxidant enzymatic system.
PMID- 10694039
TI - The chemical behaviour of heavy metals plays a prominent role in the induction of
oxidative stress.
AB - It is often described that different environmental stress factors stimulate the
production of reactive oxygen species and increase the activity of several
enzymes quenching these radicals. The ascorbate-glutathione pathway is also
involved in plant defence against oxidative stress. Therefore the effects of 2
metals (Cu, Zn) with different chemical behaviour were investigated on the
enzymes of this pathway in the primary leaves of bean seedlings grown on
hydroponics and supplied with a 50 microM concentration of both metals. The
results obtained demonstrate that the capacities of the enzymes involved in the
ascorbate-glutathione pathway increase after metal application, indicating that
they induce oxidative stress indeed. However striking differences in the relative
induction time of these enzymes suggest that the chemical behaviour of the metals
applied, plays an important role in the induction of oxidative stress as well as
in the defence mechanism against it.
PMID- 10694040
TI - Oxidative stress induced by copper in sunflower plants.
AB - The toxic effect of copper was evaluated in sunflower plants by means of root
elongation, lipid peroxidation and antioxidative enzyme activities. Plants were
grown under controlled environmental conditions in hydroponic culture for two
weeks and exposed to different copper concentrations for an additional week.
Determinations were performed in both roots and leaves. From the results of the
root elongation test, a copper concentration of 10 microM was found to be toxic
for sunflower plants causing lipid peroxidation and, thus, oxidative stress.
Antioxidative enzymes (peroxidase and superoxide dismutase) responded at lower,
nontoxic copper concentrations.
PMID- 10694041
TI - Inhibition of catalase by sulfite and oxidation of sulfite by H2O2 cooperating
with ascorbic acid.
AB - An oxidative detoxification of sulfite, which originates from sulfur dioxide
taken up into a leaf, has not yet been fully understood. In this study, we
discuss that redox reactions between sulfite and H2O2 have an important role for
the detoxification of sulfite. Sulfite was oxidized by H2O2 and during the redox
reaction, oxygen consumption was observed. The oxygen consumption was partially
inhibited by superoxide dismutase, indicating that O2- is generated during the
redox reaction. Oxidation of sulfite by H2O2 was also observed in the presence of
ascorbic acid, and during the oxidation, no significant oxidation of ascorbic
acid and no consumption of oxygen were observed. Sulfite inhibited catalase of
cell-free extracts of spinach, pea and broad bean leaves. These results suggest
that when leaves are fumigated with SO2 in the light, catalase is inactivated
resulting in the accumulation of H2O2 in leaves, which can oxidize sulfite
without generating active oxygen species like O2- as long as ascorbate is present
in leaves.
PMID- 10694042
TI - Antioxidative defense and photoprotection in Pinus halepensis induced by
Mediterranean conditions and ozone exposure.
AB - Pigment levels and antioxidative stress-related metabolites were determined over
a period of two years in Pinus halepensis to characterize the response of some
plant protective processes to both environmental stresses and 03 exposure. Two
year-old-Aleppo pine seedlings were grown in open-top chambers under optimal
nutrient and water conditions and exposed to different 03 levels: charcoal
filtered air, non-filtered air and nonfiltered air plus 40 ppb O3 10 h/day. In
summer an activation of photoprotective systems was observed since a decrease in
chlorophyll levels, an increase in the carotenoid/chlorophyll ratio and SOD
activation were recorded. Interestingly, the SOD activity in Pinus halepensis was
highly related to low-molecular weight compounds and this relationship increased
with needle age. Ozone exposure induced alterations in the activity of some
antioxidant enzymes along with reductions in pigment concentrations and an
activation of the xanthophyll cycle.
PMID- 10694043
TI - Responses of the xanthophyll cycle pool and ascorbate-glutathione cycle to ozone
stress in two tobacco cultivars.
AB - Plants of Nicotiana tabacum (O3-tolerant cv Bel-B and O3-sensitive cv Bel-W3)
were exposed to 150 ppb of ozone for 5 h; the fumigation produced visual injury
in mature leaves, particularly in Bel-W3. After O3-treatment the pigments of the
xanthophyll cycle pool decreased in both cvs, with a strong reduction in
violaxanthin content, while antheraxanthin and zeaxanthin increased slightly.
Under these conditions the content of leaf abscisic acid (ABA) markedly
increased, particularly in O3-sensitive cv, indicating that the violaxanthin may
have been partially converted into ABA. The control plants of Bel-B showed an
ascorbic acid content four times greater than Bel-W3 and the ozone treatment did
not produce significant differences in the ascorbic acid content and in the redox
state. The two tobacco cvs were found to have similar total glutathione content,
however the redox state was lower in O3-sensitive cv and decreased after ozone
exposure. Ozone fumigation caused an increase in oxidized glutathione,
particularly in Bel-W3, associated with a reduced glutathione reductase (GR)
activity and a reduced GR protein content.
PMID- 10694044
TI - Health effects and bioavailability of dietary flavonols.
AB - Flavonoids are polyphenolic compounds that are ubiquitously present in foods of
plant origin. Flavonoids are categorised into flavonols, flavones, catechins,
flavanones, anthocyanidins, and isoflavonoids. They may have beneficial health
effects because of their antioxidant properties and their inhibitory role in
various stages of tumour development in animal studies. It is estimated that the
human intake of all flavonoids is a few hundreds of milligram per day. Flavonoids
present in foods used to be considered non-absorbable because they are bound to
sugars as beta-glycosides. However, we found that human absorption of the
quercetin glycosides from onions (52%) is far better than that of the pure
aglycone (24%). The sugar moiety is an important determinant of their absorption
and bioavailability. Flavonol glycosides might contribute to the antioxidant
defences of blood. The average intake of the flavonols quercetin, myricetin and
kaempferol and the flavones luteolin and apigenin in the Netherlands was 23
mg/day. The intake of these flavonols and flavones was inversely associated with
subsequent coronary heart disease in some but not all prospective epidemiological
studies. A protective effect of flavonols on cancer was found in one prospective
study; two others showed no association. Thus the epidemiological evidence does
not yet allow a decision on the involvement of flavonols in the etiology of
either cardiovascular diseases or cancer.
PMID- 10694045
TI - Inhibition of biochemical model reactions for inflammatory processes by plant
extracts: a review on recent developments.
AB - All processes of oxygen activation include very reactive intermediates.
Therefore, aerobic cells must cope with- and to some extent also adapt to-
oxidative stress provoked for example by infections or intoxications, where these
reactive intermediates accumulate. Dependent on the strength of these impact,
several symptoms indicate the deviation from normal, steady-state-metabolism.
Intrinsic radical scavenging processes or compounds administered with food thus
have to warrant metabolic control within certain limits. Antioxidants which in
many cases are free radical scavengers or quenchers of activated states comprise
a wealth of classes of organic molecules including phenolics, probably as the
most prominent ones. In this communication mechanisms of protection from
oxidative damage are discussed. Furthermore, examples of antioxidative functions
of a few important natural products in certain diseases are reported.
PMID- 10694046
TI - Methods to measure the antioxidant activity in plant material. A comparative
discussion.
AB - Methods to determine total antioxidant activity (TAA) are generally based on the
inhibition of certain reactions by the presence of antioxidants. The most widely
used methods are those that involve the generation of radical compounds, and it
is the presence of antioxidants that determines the disappearance of these
radicals. Strategies for measuring TAA are discussed, particularly the different
methodological and instrumental approaches used. In addition, our own methods are
presented in order to facilitate and speed up the manipulation of biological
material. The values of TAA by different compounds are presented and compared.
PMID- 10694047
TI - Photooxidative bleaching of chlorophyllin.
AB - Chlorophyllin, a water-soluble, copper-containing porphyrin, can be bleached
rapidly in the light or slowly in the dark in a reaction which is oxygen
dependent. Both the photo and the dark bleaching reactions are temperature
dependent. Cyclic voltammetry measurements show that the copper in the bleached
and nonbleached state remains in the +2 redox state and could be readily reduced.
This would imply that there is no net oxidative change to the copper during the
bleaching process. FT-IR absorption spectroscopy showed vibrations characteristic
of a vinyl functionality disappeared upon bleaching. Aqueous solutions of
chlorophyllin were not dialyzable through dialysis tubing of molecular weight cut
off, 6000-8000 molecular weight, indicative of an aggregate chlorophyllin
micelle. Analysis of products by high performance liquid chromatography showed
that the chlorophyllin mixture was more complex than originally anticipated and
that two components were lost from the mixture upon photobleaching. One compound
that is preferentially lost upon photobleaching has been identified by mass
spectral analysis as Cu(II) chlorin e6.
PMID- 10694048
TI - Response of abietane diterpenes to stress in Rosmarinus officinalis L.: new
insights into the function of diterpenes in plants.
AB - Abietane diterpenes were measured in field-grown rosemary (Rosmarinus officinalis
L.) plants throughout the year. Carnosic acid and carnosol, which were present in
high amounts (5 and 1 mg/gDW respectively) in rosemary leaves, decreased by ca.
50% during the Mediterranean summer in response to low precipitation, high
radiation and high temperature. In contrast, the highly oxidised diterpenes
rosmanol, isorosmanol and dimethyl isorosmanol, which are formed from carnosic
acid by enzymatic dehydrogenation and the action of activated oxygen, increased
in response to such environmental constraints. Collectively, these data support
the contention that abietane diterpenes from R. officinalis function as
antioxidants that protect biological membranes from oxidative stress. This is
especially important during the Mediterranean summer when there is low
precipitation, high light and high temperature.
PMID- 10694049
TI - Antioxidants and protective pigments of Pinus ponderosa needles at gradients of
natural stresses and ozone in the San Bernardino Mountains in California.
AB - At the San Bernardino Mountains, California, a well documented gradient of ozone
pollution overlays a natural stress gradient from mesic to dry and from lower
elevation to higher elevation sites. In contrast to gradient studies in European
regions, the highest ambient ozone levels are observed at low elevation and more
mesic locations. In the present study, antioxidative and photoprotective systems
in Pinus ponderosa needles were investigated at three plots--DW (1725 m, high
ozone impact, mesic site), SW (1200 m, clean air, xeric site) and CO (above 2000
m, clean air and xeric site). Needles from the CO site contained significantly
more total GSH (500 vs 300 nmol g(-1) dw in c needles), less alpha-carotene (6-10
vs 14-19 microg mg(-1) total chlorophyll) and chlorophyll (1.7-2 vs 2.5-2.6 mg g(
1) dw in c + 1 needles) than those at the DW site. Furthermore, their xanthophyll
cycle pool was in a more de-epoxidized state at midday (up to 60% in c needles),
and the carotenoid/chlorophylls ratios were generally higher. These patterns
correspond to those observed at higher elevation plots in the Alps. On the other
hand, needles from the high ozone site (DW) had a higher proportion of GSSG,
indicating the onset of biochemical injury to needles. Needles from the SW site
had intermediate proportions of GSSG. The results show the potential of
environmental stressors to induce antioxidative and photoprotective responses in
the absence of elevated ozone concentrations, but support the oxidative effects
of ozone injury to ponderosa pine.
PMID- 10694050
TI - Effects of an oxidizing agent (hydrogen peroxide) on the glutathione system in
epidermal cells of Allium cepa L. investigated by histochemical staining.
AB - The glutathione system in epidermal cells of Allium cepa L. was measured by a
quantitative image analysis method, using histochemical staining by
monochlorobimane. Blockage of thiol groups with N-ethylmaleimide decreased
fluorescence to a small rest fluorescence of maximum 5%. Pre-treatment with
dithiothreitol increased fluorescence yield in all cells compared to the
monochlorobimane treatment alone. These results correspond to the blockage or the
reduction of the total pool of glutathione in the cells. After treatment with N
ethylmaleimide and subsequent incubation with dithiothreitol followed by
labelling with bimane a low fluorescence yield was observed which correspond to
the proportion of GSSG. Specimens that were incubated in H2O2 prior to the
treatments described above exhibited a decrease in total glutathione and in
reduced glutathione and an increase in the proportion of GSSG compared to the
control.
PMID- 10694051
TI - Vitamin E supplementation increases the stability and the in vivo antioxidant
capacity of refined olive oil.
AB - Two experiments were carried out to investigate if the supplementation with
vitamin E affects refined olive oil response to oxidation regarding the stability
of the oil and the protection in vivo against lipid peroxidation in rats after
its intake in comparison with other edible oils. In experiment 1, samples of
virgin olive oil, refined olive oil, refined olive oil supplemented by us with
200 mg/kg vitamin E, and sunflower oil were collected before and after a 60 min
frying process. After frying, refined olive oil supplemented with vitamin E
compared with the non-supplemented refined olive oil had a higher concentration
of alpha-tocopherol (240.34+/-6.07 mg/kg vs. 131.94+/-8.14 mg/kg), more
resistance against oxidation (19.01+/-1.88% vs. 10.6+/-2.08%) and less polar
components (4.2+/-0.06% vs. 5.45+/-0.22%). In experiment 2, 24 male Wistar rats,
divided into 4 groups, were fed on diets based on the same unfried oils (8% w/w)
as in experiment 1, for 4 weeks. Two days prior to the end of the experiment, the
rats were intraperitoneally administered with adriamycin (10 mg/kg/ day) to
provoke an oxidative stress. The rats fed on refined olive oil plus vitamin E
compared to the rats fed on non-supplemented refined olive oil had lower
hydroperoxides concentrations (26.8+/-2.6 nmol/mg vs. 35.6+/-2.49 nmol/mg) higher
coenzyme Q levels (128.1+/-11.97 pmol/mg vs. 81.25+/-9.25 pmol/mg) and higher
alpha-tocopherol values (1.23+/-0.04 mmol/mg vs. 0.93+/-0.06 mmol/mg) in
microsomes of liver. In conclusion, the supplementation of refined olive oil with
200 mg/kg of vitamin E increases the stability of this oil under pro-oxidant
conditions, and its intake decreases the oxidative damage generated by adriamycin
in rats.
PMID- 10694052
TI - Recent advances in understanding the origin of the apoplastic oxidative burst in
plant cells.
AB - The origin of the oxidative burst during plant-pathogen interactions remains
controversial. A number of possibilities have been identified, which involve the
protoplast, plasmalemma or apoplast. The apoplastic production of H2O2 requires
three components, an extracellular peroxidase, ion fluxes leading to
extracellular alkalinisation and release of a substrate. Fatty acids are the
major compounds that appear in the apoplast following elicitation, which can
activate H2O2 production by peroxidases in vitro. However, the reaction with
peroxidases appears to be novel and is uncharacterised at present. The apoplastic
mechanism also cannot be readily distinguished from the operation of a plasma
membrane NADPH oxidase system by the use of the inhibitors diphenylene iodonium
and N,N diethyl-dithiocarbamate since it is also inhibited by these. These
inhibitors have often in the past been used to define the involvement of the
latter in the oxidative burst. In common with the NADPH oxidase system, the
peroxidase responsible has been cloned but unlike the NADPH oxidase it has been
shown to function in vitro to generate H2O2. In vivo studies of the oxidative
burst have shown that the alkalinisation is essential and the underlying ion
fluxes may be regulated by cAMP. Calcium fluxes are also essential. Although the
oxidative activity of peroxidase requires calcium the fluxes have obvious other
function. These may include activation of release of substrate and through the
activation of a CDPK, regulation of enzymes involved in phytoalexin and cell wall
phenolic production such as PAL.
PMID- 10694053
TI - Some properties of the H2O2/O2- generating system from the lignifying xylem of
Zinnia elegans.
AB - The properties of the enzymatic system responsible for generating H2O2/O2- in the
lignifying xylem of Zinnia elegans were studied using the starch/KI method for
monitoring H2O2 production and the nitroblue tetrazolium method for monitoring
superoxide anion production. The results showed that H2O2/O2- production by
lignifying xylem tissues was insensitive to inhibitors of peroxidase and
poly(di)amine oxidases. However, H2O2/O2 production in the xylem of Z. elegans
was sensitive to the inhibitors of phagocytic plasma membrane NADPH oxidase,
pyridine, imidazole, quinacrine and diphenylene iodonium. The sensitivity of
H2O2/O2- production to the respective inhibitors of calmodulin (R-24571),
phospholipase C (neomycin sulfate), and protein kinase (staurosporine), and its
reversion by an inhibitor of protein phosphatases (cantharidin); pointed to the
analogies existing between the mechanism of H2O2/O2- production in the lignifying
xylem of Z. elegans and the oxidative burst observed during the hypersensitive
plant cell response. These results suggest the existence of a metabolic cascade
involving calmodulin, IP3 and protein phosphorylation in the activation of the
enzymatic system responsible for H2O2/O2- production in the lignifying xylem of
Z. elegans.
PMID- 10694054
TI - Elevation of glutathione level and activation of glutathione-related enzymes
affect virus infection in tobacco.
AB - The effects of two chemicals, L-2-oxothiazolidine-4-carboxylic acid (OTC) and (S)
carvone, were investigated on the development of necrotic symptoms and on the
virus concentration in tobacco mosaic virus (TMV)-infected tobacco plants. OTC
treatments markedly increased the cellular glutathione (GSH) levels in tobacco
leaf discs. In addition, OTC pretreatment considerably decreased both the number
of necrotic lesions and the virus content in TMV-infected leaf discs. The
monoterpene (S)-carvone increased only slightly the GSH content of leaf tissues
and caused lipid peroxidation. (S)-carvone dramatically induced the activity of
glutathione S-transferase and to a lesser extent elevated also the activities of
ascorbate peroxidase and glutathione reductase. Treatments with (S)-carvone
strongly reduced the number and size of necrotic lesions, but did not influence
the virus concentration. The results show that increased levels of GSH and
activities of GSH-related enzymes by OTC and (S)-carvone reduce necrotization of
virus-infected tissues. However, virus multiplication and lesion formation do not
necessarily correlate: virus multiplication is suppressed only by substantially
elevated GSH contents.
PMID- 10694055
TI - Dark stained tissues of the epicarp of encore mandarin: interactions with the
production of hydroxyl radicals.
AB - The interactions between hydroxyl radical production and the composition of the
epicarp cells associated with the dark stained tissues of mature fruits of Encore
mandarin were investigated. Phosphatidylinositol content of the cells associated
with dark stains was lower in unpitted tissues, whereas the concentration of
phosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine did not
vary significantly. In these pitted cells, protein content also showed a 1.59
fold increase. Additionally, the relative proportions of gln, thr, asp, glu and
gly increased sharply, while ala and tyr decreased. The polypeptide patterns
showed quantitative changes when samples of stained and unstained tissues were
compared by SDS-PAGE electrophoresis. Qualitatively, the cells associated with
pitted tissues revealed a new polypeptide band with an apparent mol. wt. of 50.4
kDa as well as the disappearance of another one of 10 kDa. Ethylene production in
the dark stained tissues was lower than in unpitted tissues and these cells
showed significant increases in membrane permeability, hydroxyl radical
production, and lipid peroxidation. Furthermore, in these tissues the levels of
the carotenoids increased significantly but levels of chlorophyll decreased. It
was concluded that in the pitted tissues the significant changes of the membrane
composition are closely associated with an increasing acyl lipid peroxidation
mediated by hydroxyl radical production. The modulation of this metabolism
further indicates an incomplete degradation of fatty acids. The implications of
the increasing accumulation of carotenoids in the synthesis of oxy radicals are
also discussed.
PMID- 10694056
TI - Ascorbate metabolism in potato leaves supplied with exogenous ascorbate.
AB - Photosynthesis and leaf ascorbate were measured in potato (Solanum tuberosum L.)
plants grown in low light and then transferred to high light. Total foliar
ascorbate content in low light-grown plants was 4.72+/-0.42 micromol mg(-1)chl.
Over 80% of the ascorbate pool was found in the reduced form irrespective of
position on the stem. No statistically-significant light-dependent effects were
observed. Leaf discs supplied with [14C]-ascorbate in the dark showed significant
ascorbate uptake such that after a 16h incubation over half of the total
ascorbate pool in the discs was labelled [14C]-ascorbate. No ascorbate efflux
from the leaves occurred during the period of [14C]-ascorbate uptake. The total
amount of ascorbate did not increase, however, implying modified ascorbate
turnover. The turnover of the [14C]-ascorbate in the leaves occurred at similar
rates in both light and darkness. Little degradation of labelled ascorbate was
observed, suggesting that uptake of exogenous ascorbate leads to inhibition of de
novo ascorbate biosynthesis in potato leaf discs.
PMID- 10694057
TI - Preliminary studies of ascorbate metabolism in green and albino regions of
variegated leaves of Coleus blumei, Benth.
AB - Green and white variegated leaves of Coleus blumei, Benth. were separated into
albino and green sections and used to determine the distribution of vitamin C and
L-galactose dehydrogenase activity, an enzyme supposed to be involved in
ascorbate metabolism, in heterotrophic and autotrophic foliar fractions. Both
green and white sections contained vitamin C and activity of L-galactose
dehydrogenase. However, in the white parts mainly dehydroascorbate was found,
whereas in the green parts the redox state of the ascorbate system varied with
light or dark conditions. Characterisation of L-galactose dehydrogenase from
illuminated green leaf sections showed increasing activity with increasingly
alkaline pH-values and a temperature optimum of 25 degrees C. Since these
properties were slightly different than those of L-galactose dehydrogenase
activities obtained from albino or darkened green leaf sections, we suggest that
the enzyme may be light-modulated.
PMID- 10694058
TI - Chlorophyll high-temperature thermoluminescence emission as an indicator of
oxidative stress: perturbating effects of oxygen and leaf water content.
AB - A high-temperature chlorophyll thermoluminescence emission can be observed in
plant leaves, without preillumination, following various oxidative stresses. This
emission was recorded from 0 degrees C to 160 degrees C on a leaf sample pressed
by a teflon ring on a heating plate. A band at 140 degrees C was observed in
senescing tree leaves, a band at 130 degrees C with a shoulder at 75 degrees C in
tobacco leaves treated with the fungal elicitor cryptogein. Measurements in pure
O2 or N2 atmospheres did not affect the 130/140 degrees C band, although oxygen
increased the thermoluminescence emission at higher temperatures and should be
consequently eliminated during measurements. Preventing desiccation by covering
the sample with a glass window suppressed the 130/140 degrees C band, except for
its rising edge at about 80/90 degrees C. This broad 130/140 degrees C band
results from the chlorophyll-exciting thermolysis of lipid peroxides, but it
disappears when water is kept in the sample up to 100 degrees C, due to a non
radiative hydrolysis of the peroxides. Therefore, high-temperature
thermoluminescence measurements should be performed on leaf samples allowed to
dry under an oxygen-free atmosphere.
PMID- 10694059
TI - Does ozone exposure protect from photoinhibition?
AB - Tropospheric ozone and high light intensities are two stress factors that often
occur simultaneously under natural conditions. Ozone is well known to form oxygen
radicals in the apoplastic water and long lasting photoinhibition can cause
photooxidative damage also by formation of several species of oxygen radicals. We
were interested whether moderate levels of ozone would be able to modulate the
response of leaves to photoinhibitory conditions naturally occurring around noon
on a bright day. Cuttings of Populus sp. were cultivated in two separate
greenhouse-compartments adapted as fumigation chambers. In the two compartments
plants were grown in ambient air containing about 20 nmol mol(-1) ozone and in
elevated ozone concentrations supplied for 8 h per day. During the midday of
bright days Fv/Fm decreased by the same amount in all leaves, indicating
photoinhibition. At the same time Fo increased in control leaves more than in
ozone-exposed leaves indicating a higher amount of heat-deactivating PSII centres
in the latter. This was confirmed by a higher epoxidation state in ozone-exposed
leaves during midday of a bright day. The contents of chlorophyll a and
chlorophyll b were significantly decreased in ozone-exposed leaves. In older
leaves the ratios chlorophyll a : b, and xanthophylls: chlorophyll b were
increased indicating an adaptation to higher light stress. From this we conclude
that by increasing the amount of heat-deactivating centres ozone seems to protect
PSII from photoinhibition.
PMID- 10694060
TI - Activated oxygen generation from thylakoids: a novel spin trap.
AB - Using a novel phosphorylated spin trap, 5-(diethoxyphosphoryl)-5-methyl-1
pyrroline-N-oxide (DEPMPO), an analogue of the commonly used spin trap 5,5'
dimethyl-1-pyrroline N-oxide (DMPO), we have investigated the production of
oxygen radical species under illumination of thylakoids from wheat (Triticum
durum Desf cv. Ofanto). DEPMPO reacted with superoxide (O2*-) and hydroxyl
radical (HO*) forming distinctive spin trap adducts. Spectra of (O2*-) and HO*
adducts of DEPMPO were recorded in the presence of xanthine/xanthine oxidase and
FeSO4/H2O2, respectively, and computer simulation of spectra was performed.
During illumination of thylakoids both O2*- and HO* were detected as well.
Transition metals catalysed transformation of O2*- into HO*. The conversion was
enhanced by H2O2 and prevented by exogenous superoxide dismutase and catalase.
The presence of a thylakoid-bound superoxide dismutase, whose activity was
inhibited by H2O2 and diethyldithiocarbamic acid, was responsible for H2O2
production from O2*- and thus for HO* generation.
PMID- 10694061
TI - Nitric oxide generation by soybean embryonic axes. Possible effect on
mitochondrial function.
AB - Nitric oxide (NO) generation and its effect on mitochondrial enzymes were
investigated in soybean embryonic axes at the onset of germination. NO was
detected in homogenates from soybean embryonic axes by EPR. Enzymatic sources of
NO, such as nitrate reductase activity and nitric oxide synthase, assessed as
NADPH-diaphorase activity, were measured in homogenates incubated up to 48 h.
Both NO content and the activity of the enzymes showed a similar profile as
function of the imbibition time, with maximal levels at 15-24h. Total O2
consumption in enriched-mitochondrial fraction was inhibited by NO in a
concentration-dependent manner. O2 consumption dependent on cytochrome oxidase
activity was more sensitive than alternative oxidase pathway to NO exposure. Half
maximal effects of NO at 0.3 and 3.6 microM were measured for cytochrome oxidase
and alternative oxidase, respectively. Enriched-mitochondrial fractions from
soybean embryonic axes treated with NO (up to 1 microM) showed increased H2O2
production. The data presented suggest that NO could modulate O2 consumption in
soybean embryonic axes. This process could affect the pro-oxidant/antioxidant
balance and the cellular energy yield in the germinating embryonic axes, and
could have a role in soybean germination.
PMID- 10694062
TI - Characterisation of a cDNA encoding gamma-glutamylcysteine synthetase in Medicago
truncatula.
AB - A gamma-ECS cDNA from Medicago truncatula was isolated using an Arabidopsis
thaliana cDNA as probe. The analysis of the amino acid sequence deduced from this
cDNA revealed 80% identity with the gamma-ECS from A. thaliana and Brassica
juncea and suggested a plastidial localisation for the enzyme. Gamma-ECS activity
and high level of GSH were detected in the gamma-ECS-deficient E. coli strain
expressing a fusion protein containing the M. truncatula gamma-ECS protein.
Southern blot analysis suggests that gamma-ECS is encoded by a small multigenic
family in M. truncatula and shows that homologous genes are present in two other
leguminous plants, Medicago sativa and Pisum sativum. Gamma-ECS gene expression
was analysed by Northern blot in seedlings, plantlets and mature plants.
PMID- 10694063
TI - Differential gene expressions of rice superoxide dismutase isoforms to oxidative
and environmental stresses.
AB - Active oxygen species (AOSs) are produced under stress conditions of plant cells.
Superoxide dismutase (SOD) catalyzes the first step in the AOS scavenging system.
The responses of SOD genes to environmental stresses were analyzed in rice
seedlings by the treatments of drought, salinity and chilling. The expressions of
abscisic acid (ABA)-inducible genes, Mn-SOD gene (sodA1) and one of the cytosolic
Cu/Zn-SOD genes (sodCc2), were strongly induced by the treatment of drought and
salinity. While Fe-SOD gene (sodB) and the other cytosolic Cu/Zn-SOD gene
(sodCc1) were also induced by ABA. However the mRNA level of sodB was decreased
by drought treatment, and sodCc1 gene was not induced by drought and salinity
treatments. Plastidic Cu/Zn-SOD gene (sodCp) quickly responded to salinity
treatment in the light but not in the dark. In the treatment with hydrogen
peroxide, sodCp gene was strongly induced shortly after the treatment. These
results suggested that phytohormone and AOSs are associated with the regulation
of SOD genes under environmental stresses.
PMID- 10694064
TI - Sunflower (Helianthus annuus) variability in antioxidant enzyme defenses.
AB - In order to investigate the existence of genetic variability in antioxidant
enzyme defenses in sunflower, twelve inbred lines, six cytoplasmic male-sterile
and six restorer lines, commonly used in breeding programs have been compared
with respect to (a) their levels of constitutive superoxide dismutase (SOD, EC
1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11),
glutathione reductase (GR, EC 1.6.4.2) and guaiacol-dependent peroxidase (GPX, EC
1.11.1.7), and (b) their isoenzyme polymorphism in SOD, CAT, and GPX activities.
Constitutive levels of antioxidant enzymes in the 2nd leaf pair of 15-20-day-old
sunflower plants showed significant differences between lines. The ranges of
variation in enzyme activities of the different lines were equivalent to 34.3%
(CAT), 38.2% (SOD), 59.5% (APX), 60.0% (GR), and 62.9% (GPX) of the respective
maximal values. Isoenzyme profiles of CAT, GPX and SOD revealed the existence in
sunflower of at least three, six and four isoforms of these enzymes,
respectively. Further characterization of SOD isoenzymes revealed that no
isoenzyme corresponded to a Mn-SOD, the faster moving isoform being a Cu/Zn-SOD
and the remainder three Fe-SODs. Among the twelve inbred sunflower lines studied
there were ample qualitative, and sometimes quantitative too, differences in
isoenzyme dotation of CAT, GPX and Fe-SOD.
PMID- 10694065
TI - Purification of catalase from pea leaf peroxisomes: identification of five
different isoforms.
AB - Catalase activity was analyzed in seven organs of pea (Pisum sativum L.) plants:
leaves, seeds, flowers, shoots, whole fruits, pods and roots. Leaves showed the
highest activity followed by whole fruits and flowers. Catalase was purified from
pea leaf peroxisomes. These organelles were isolated from leaves by differential
and sucrose density-gradient centrifugation, and catalase was purified by two
steps involving anion exchange and hydrophobic chromatography using a Fast
Protein Liquid Chromatography system. Pure catalase had a specific activity of
953 mmol H2O2 min(-1) mg(-1) protein and was purified 1000-fold, with a yield of
about 19 microg enzyme per kg of pea leaves. Analysis by SDS-PAGE and immunoblot
showed that the pea catalase was composed of subunits of 57 kDa. Ultraviolet and
visible absorption spectra of the enzyme showed two absorption maxima at 252 and
400 nm with molar extinction coefficients of 2.14 x 10(6) and 7.56 x 10(6) M(-1)
cm(-1), respectively. By isoelectric focusing (pH 5-7), five different isoforms
were identified and designated as CAT1-5, with isoelectric points of 6.41, 6.36,
6.16, 6.13 and 6.09, respectively. All the catalase isoforms contained a subunit
of 57 kDa. Post-embedment, EM immunogold labelling of catalase showed a uniform
distribution of the enzyme inside the matrix and core of pea leaf peroxisomes.
PMID- 10694066
TI - Catalase-peroxidases in cyanobacteria--similarities and differences to ascorbate
peroxidases.
AB - Cyanobacteria (blue-green algae) are oxygenic phototrophic bacteria carrying out
plant-type photosynthesis. The only hydrogen peroxide scavenging enzymes in at
least two unicellular species have been demonstrated to be bifunctional cytosolic
catalase-peroxidases (CatPXs) having considerable homology at the active site
with plant ascorbate peroxidases (APXs). In this paper we examined optical and
kinetic properties of CatPXs from the cyanobacteria Anacystis nidulans and
Synechocystis PCC 6803 and discuss similarities and differences to plant APXs.
Both CatPXs and APX showed similar spectra of the ferric enzyme, the redox
intermediate Compound I and the cyanide complex, whereas the spectrum of CatPX
Compound II had characteristics reminiscent of the spectrum of the native enzyme.
Both steady-state and multi-mixing transient-state kinetic studies were performed
in order to characterize the kinetic behaviour of CatPXs. Bimolecular rate
constants of both formation and reduction of a CatPX Compound I are presented.
Because of its intrinsic high catalase activity (which cannot be found in APXs),
the rate constants for Compound I formation were measured with peroxoacetic acid
and are shown to be 5.9 x 10(4) M(-1) s(-1) for CatPX from A. nidulans and 8.7 x
10(3) M(-1) s(-1) for the Synechocystis enzyme. Compared with o-dianisidine (2.7
6.7 x 10(6) M(-1) s(-1)) and pyrogallol (8.6 x 10(4)-1.6 x 10(5) M(-1) s(-1)),
the rate constant for Compound I reduction by ascorbate was extremely low (5.4 x
10(3) M(-1) s(-1) at pH 7.0 and 15 degrees C), in marked contrast to the
behaviour of APXs.
PMID- 10694067
TI - Catalase activity during C3-CAM transition in Mesembryanthemum crystallinum L.
leaves.
AB - Treatment with 0.4 mol dm(-3) NaCl caused a C3-CAM shift in Mesembryanthemum
crystallinum L. leaves. In parallel to the CAM induction the activity of CAT was
significantly decreased. In C3 and in CAM plants CAT activity showed daily
fluctuations, with the maximum at the end of the light period. The oscillations
of CAT were more pronounced in CAM than in C3 plants. In M. crystallinum CAT
activity seems to respond more to CAM induction than to salinity.
PMID- 10694068
TI - Laparoscopy at the millennium.
PMID- 10694069
TI - A systematic history for the patient with chronic pelvic pain.
AB - Chronic pelvic pain is a source of frustration to both the physician and the
patient. Physicians have been ill equipped by their training to confront the
multifaceted nature of the complaints of patients with chronic pelvic pain.
Patients have experienced a repetitive dismissal of their complaints by
physicians too busy in their practices to address their problems comprehensively.
The approach to the patient with chronic pelvic pain must take into account six
major sources of the origin of this pain: 1) gynecological, 2) psychological, 3)
myofascial, 4) musculoskeletal, 5) urological, and 6) gastrointestinal. Only by
addressing and evaluating each of these components by a very careful history and
physical examination and by approaching the patient in a comprehensive manner can
the source of the pain be determined and appropriate therapy be administered.
This article was developed to provide the clinician with a set of tools and a
methodology by which the patient with this complaint can be approached.
PMID- 10694070
TI - Combining myoma coagulation with endometrial ablation/resection reduces
subsequent surgery rates.
AB - BACKGROUND: This study compares results of endometrial ablation alone and in
combination with myoma coagulation. Subsequent surgery rates were 38% for
ablation alone and 12% for combined therapy. OBJECTIVE: The purpose of this study
was to compare hysterectomy rates following various surgical procedures to treat
profuse uterine bleeding as well as myomatous uteri. STUDY DESIGN: This is a
descriptive study of women who underwent endometrial ablation alone, endometrial
ablation with myoma coagulation, or endometrial resection with myoma coagulation
to treat profuse uterine bleeding as well as myomatous uterus. From 1986 to 1995,
the author performed 52 endometrial ablation procedures; 88 myoma coagulation and
endometrial ablation procedures; and 28 myoma coagulations with resection of
submucous myomas in patients who were subsequently available for follow-up.
Patients were followed up for up to ten years. RESULTS: Of the patients
undergoing ablation alone, 20 (38%) of 52 required a second surgery for continued
symptoms during a mean follow-up of 47 months. Five of these patients (9.6%)
underwent hysterectomy. Of the patients who underwent endometrial ablation plus
myoma coagulation (myolysis), 11 (12.5%) of 88 required a repeat surgical
procedure during a mean follow-up of 25 months. Five of these patients (5.7%)
underwent hysterectomy. Volumetric measurements revealed an average reduction in
fibroid volume of 54.5% in this patient group following treatment with a
gonadotropin-releasing hormone (GnRH) agonist and combined myoma coagulation and
endometrial ablation surgery. Of the 28 patients who underwent myoma coagulation
plus resection, five (18%) required a repeat procedure. Of these five, one (4%)
required hysterectomy. Fibroid volume in this group was reduced by a mean of
72.6% following administration of a GnRH agonist and combined laparoscopic and
hysteroscopic surgery as described. The rate of reoperation was significantly
lower among patients receiving endometrial ablation with myoma lysis with or
without resection compared with those undergoing endometrial ablation alone
(P<0.01). CONCLUSIONS: Myoma coagulation (myolysis), when combined with
endometrial ablation among women with symptomatic fibroids and bleeding, reduces
all subsequent surgery rates compared with endometrial ablation alone. Myolysis
with endometrial resection also results in a reduced need for hysterectomy.
PMID- 10694072
TI - The accuracy of gastric insufflation in testing for gastroesophageal perforations
during laparoscopic Nissen fundoplication.
AB - BACKGROUND: Laparoscopic Nissen fundoplication is an effective technique for the
symptomatic relief of the manifestations of gastroesophageal reflux disorder but
is associated with a 0.8-1% rate of gastroesophageal perforation. Early detection
and repair of these injuries is critical to patient outcome, but occult injuries
occur and may be missed. Gastric insufflation technique evaluates the integrity
of the gastroesophageal wall after laparoscopic Nissen fundoplication. Gastric
insufflation technique involves occlusion of the proximal stomach with a
noncrushing bowel clamp while insufflating the submerged gastroesophageal
junction. We conducted an animal study to assess the utility of gastric
insufflation technique. METHODS: Five pigs (mean weight, 40.4 kg) underwent
testing of laparoscopic gastric insufflation technique. In four animals,
laparoscopic Nissen fundoplication was performed and then gastroesophageal
junction injuries were created (3-5 mm distraction-type wall injuries). Non
crushing bowel clamps provided occlusion of the pylorus and then the proximal
stomach during gastroesophageal insufflation. The gastroesophageal junction was
then submerged. In the fifth animal, gastric insufflation technique was repeated
while calibrated injuries were created to determine the smallest detectable
injury. An injury was considered detectable if rising air bubbles were noted from
the submerged gastroesophageal structures. Maximal luminal pressures needed to
detect injuries were recorded with an in-line manometer. RESULTS: In all animals,
5-7 mm injuries of the gastroesophageal junction were easily detected using
gastric insufflation technique when the proximal stomach was occluded. When the
pylorus alone was occluded, detection of gastroesophageal injuries was
inconsistent. Small injuries (<3 mm) of the esophagus were difficult to visualize
with pyloric occlusion alone but were consistently detectable with proximal
stomach occlusion at pressures less than 20 mm Hg. When the pylorus alone was
occluded, the smallest detectable stomach perforation was a 16-gauge needle
puncture while applying maximal gastric pressure (40-60 mm Hg) and a 2.5 mm
linear injury when generating lower pressures (20 mm Hg). CONCLUSION: Proximal
stomach occlusion and insufflation appears to effectively detect esophageal
injuries of likely clinical importance (>2.5 mm). Pyloric occlusion and
insufflation reliably evaluates the anterior stomach for injury. Gastric
insufflation technique is a useful method for detecting gastroesophageal injury
after laparoscopic Nissen fundoplication.
PMID- 10694071
TI - Laparoscopic Nissen fundoplication in children: a single surgeon's experience.
AB - BACKGROUND AND OBJECTIVES: Adult laparoscopic Nissen fundoplication has been
steadily growing since its introduction to the United States in the 1990s. Its
advantage over the traditional open approach is manifold. Application of
laparoscopic fundoplication to children is slowly but surely following this
trend. This study evaluates our initial experience with pediatric laparoscopic
Nissen fundoplications. PATIENTS AND METHODS: We reviewed the records of 25
consecutive laparoscopic Nissen fundoplications performed by a single surgeon
(GS) at our institution in the past three years. The patient ages ranged from 7
months to 18 years (mean, 7 years). All patients had documented gastroesophageal
reflux disease. Complications from the reflux included vomiting in 15 patients,
failure to thrive in nine, esophagitis in nine, and pulmonary symptoms in six.
RESULTS: All Nissen fundoplications were performed laparoscopically without need
for conversion to open technique. Blood loss was less than 50 cc in all cases. A
tube gastrostomy was concurrently performed in 17. Mean operative time in all
cases was 221 minutes. Average postoperative day on which feedings were begun was
day 2, with an average resumption of regular feedings on postoperative day 3.5.
Average date of discharge was postoperative day 6.8. Complications included
difficulty controlling glucose in an insulin-dependent diabetic, and a lost
needle, which added an additional hour to the operative time. There were eight
admissions to the pediatric intensive care unit, all for observation secondary to
their underlying medical problems. There was one postoperative death due to an
underlying medical condition. CONCLUSIONS: Laparoscopic Nissen fundoplication is
a safe and effective treatment option for children suffering from significant
reflux. Time to regular feeding, analgesia requirements and hospital stay are
decreased when compared to traditional procedures. Laparoscopic Nissen
fundoplication may well become the procedure of choice for pediatric
gastroesophageal reflux disease.
PMID- 10694073
TI - Laparoscopic surgery for female urinary incontinence: prudence shall prevail.
AB - Advances in laparoscopic techniques continue to seek new domains and new
indications with the sole objective of providing maximum benefit in a minimally
invasive manner. During the last decade, several innovative laparoscopic
procedures have evolved for the management of female urinary incontinence. At
this juncture, prudence dictates a careful analysis of the principles behind and
performance of these procedures so that our treatment recommendations for this
common ailment can be based on unbiased scientific pragmatism. In this review, we
attempt to analyze the available data and provide constructive criticism and
recommendations toward the continued pursuit in this area of development in
laparoscopy.
PMID- 10694074
TI - Laparoscopic versus open appendicectomy: a comparative study.
AB - There are many questions regarding the advantages and disadvantages a
videolaparoscopic approach in the treatment of acute appendicitis. The authors
present the results of a non-randomized, prospective study with 496 patients
admitted between January 1992 and March 1998 by the General Surgery Service of
Sao Rafael Hospital Salvador-BA-Brazil. The patients were submitted for
appendicectomy by video laparoscopy or by the traditional open method, and
variables such as surgery duration, morbidity, mortality, costs, and length of
stay (LOS) were compared. The results demonstrate that laparoscopic
appendicectomy is a safe alternative for treatment of acute appendicitis;
however, there are several disadvantages that gradually must be overcome.
PMID- 10694075
TI - Laparoscopic appendectomy and minilaparoscopic approach: a retrospective review
after 8-years' experience.
AB - BACKGROUND: This is a presentation of our 8-year experience in laparoscopic
appendectomy, showing complications and results to determine the advantages and
efficacy of laparoscopy. METHODS: We used this technique from December 1990 to
December 1998 on 282 consecutive and non-selected patients (169 females and 113
males) with an average age of 24 years (range 5-86 years). All patients were
suffering from sub-acute appendicitis or chronic appendicopathies, except for 84
(29.7%) cases of acute appendicitis and 25 (8.9%) cases of gangrenous
appendicitis with peritonitis. All patients with suspected appendicitis were
evaluated with a laparoscopic exploration. RESULTS: In 39 patients (13.9%),
appendectomy was performed along with 19 enucleated or endocoagulated ovarian
cysts, 8 adhesiolyses, 6 transperitoneal hernioplasties (4 right and 2 left), 2
cholecystectomies, 2 excisions of a Meckel diverticulum, 1 aspiration and suture
of a right tubal pregnancy and 1 electrodesiccation of pelvic endometriosis.
Thirty-five patients (12.5%) revealed the presence of a gynecological-type
pathology. We performed 2 (0.7%) conversions to open exploration and experienced
6 (2.1%) complications, of which only 1 (0.35%) was a major complication: a
delayed hemoperitoneum (1 liter), re-operated elsewhere, the cause of which was
not identified. We performed 4 (1.4%) relaparoscopies for retrocecal abscess
(three patients with primary gangrenous appendicitis and peritonitis presenting
with an abscess in the right iliac fossa and in one patient with widespread
intestinal adhesions with primary acute appendicitis). No patient with a
diagnosis of a normal appendix developed an intraperitoneal abscess. Mortality
was non-existent. The postoperative course, which was subjectively better than in
cases operated in the traditional way, was, on an average, 2 days (range 1-18
days) for appendectomies carried out with the traditional laparoscopic technique
and 1 day for appendectomies carried out with the minilaparoscopic technique (6
patients). CONCLUSION: We believe that the laparoscopic technique can handle any
type of clinical situation, as it can cure several pathologies during the same
session with minimal trauma and maximum benefit for the patient. The advantages
of a minilaparoscopy approach are based on its low invasiveness and small
surgical wounds.
PMID- 10694076
TI - Recurrences in laparoscopic incisional hernia repairs: a personal series and
review of the literature.
AB - OBJECTIVES: Laparoscopic repair of incisional ventral hernias with ePTFE mesh
continues to evolve, with variable reporting of surgical techniques and outcomes.
This report of 34 cases discusses, with a literature review of laparoscopic
incisional hernia repair, specific factors associated with three recurrences.
METHOD: Retrospective analysis and review of the literature. RESULTS: Thirty-two
patients (16 female, 16 male), underwent 34 laparoscopic repairs: average age-54
years (27-80), average weight-207 lbs (100-300). Nineteen patients (62%) were
undergoing first time repairs, 38% were redo cases and 5 cases (14%) involved
previous mesh. Operating times averaged 101 minutes (45-220), and average length
of stay was 1.9 days (0.6 days excluding 5 patients who required readmission),
with 13 patients (38%) being discharged same-day. Two patients developed
cellulitis (6%) treated without patch removal. Two enterotomies occurred (6%)
both requiring patch removal. Five patients required readmission (14%), and one
patient died postoperative day 29 secondary to end-stage liver disease. Three
recurrences developed (9%): one secondary to missed enterotomy with reoperation,
patch removal and hernia recurrence; one due to omission of suspension suture
fixation; and one recurrence developed in a section of the intact old previous
incision that extended beyond the original patch. Follow up has averaged 20
months (4-36). CONCLUSIONS: The laparoscopic repair of ventral and incisional
hernias utilizing transabdominal placement of ePTFE patch can achieve excellent
results with low morbidity in comparison with open surgical approaches. In
reviewing the experience of other investigators, adequate fixation of the mesh,
extension to cover the entire previous incision and standardizing the placement
interval of the sutures are critical to the success of the repair.
PMID- 10694077
TI - A cost and profit analysis of hernia surgery.
AB - The vast majority of surgeons who are in the active practice of their particular
field have little time to evaluate their individual practices from a "business
perspective." This fact is critical to the future of any entity that is engaged
in the delivery of goods and services. Without such an analysis, few businesses
will continue to function in such a manner that ensures the financial viability
of that enterprise. We have attempted to accumulate the available data to analyze
the practice of surgery as it relates to the cost and profit of hernia repairs.
Given this information, it is easily extrapolated into other procedures, open or
laparoscopic, that are performed by the general surgeon. The herniorraphy
analysis indicates that one cannot hope to generate enough income to rely upon a
financially successful business. The information presented should be considered a
national average and not specific to an individual practice situation. It is
meant to serve as a template for which each surgeon can (and must) evaluate his
or her own practice profitability.
PMID- 10694078
TI - Criteria and benchmarks for laparoscopic cholecystectomy in a free-standing
ambulatory center.
AB - BACKGROUND AND OBJECTIVES: Keys to economic survival in an era of decreasing
reimbursement include controlling costs and avoiding complications. In an effort
to reduce costs, laparoscopic cholecystectomy has been performed with same-day
discharge from a hospital setting. The free-standing ambulatory surgery center
offers even greater cost savings if safety can be assured. Facility charges,
surgical technique and instrument selection influence the costs of the procedure.
METHODS: A database was accumulated prospectively on the first 100 laparoscopic
cholecystectomies performed in a free-standing ambulatory surgery center to
assess costs, logistical constraints, and safety. RESULTS: Laparoscopic
cholecystectomies were accomplished in 99 of 100 patients. One patient was
suspected of having cancer during laparoscopy and was transferred to a nearby
hospital for open cholecystectomy. There were no other postoperative
hospitalizations for complications. The fixed facility charge for the procedure
was $2,990, and the total costs for all routinely disposable items (gowns,
gloves, instruments, and adhesive bandages was $98. The mean OR time was 29
minutes (standard deviation 13.7). CONCLUSIONS: The free-standing ambulatory
surgery center is an appropriate facility for an experienced operating team to
perform laparoscopic cholecystectomy in selected patients. The surgeon's
selection of appropriate energy sources and instruments is essential to complete
the operation in a most cost-effective manner.
PMID- 10694079
TI - Congenital malformations of the gallbladder and cystic duct diagnosed by
laparoscopy: high surgical risk.
AB - Congenital anomalies of the gallbladder are rare and can be accompanied by other
malformations of the biliary or vascular tree. Being difficult to diagnose during
routine preoperative studies, these anomalies can provide surgeons with an
unusual surprise during laparoscopic surgery. The presence of any congenital
anomaly or the mere suspicion of its existence demands that we exercise surgical
prudence, limit the use of electrocoagulation, and ensure that no structure be
divided until a clear picture of the bile ducts and blood vessels is obtained. If
necessary, perform intraoperative cholangiography to further define the biliary
system. However, if the case remains unclear, or if laparoscopy does not provide
enough information, open surgery should be considered before undesirable
complications occur.
PMID- 10694080
TI - Posterior hepatic duct injury during laparoscopic cholecystectomy finally
necessitating hepatic resection: case report.
AB - A case of bile duct injury during laparoscopic cholecystectomy finally
necessitating right hepatic lobectomy is reported to re-emphasize the importance
of preoperative and intraoperative assessment of the biliary tree. A 47-year-old
Japanese woman underwent laparoscopic cholecystectomy for cholecystolithiasis. On
postoperative day 5, fever and right hypochondralgia developed, and CT revealed
fluid collection at the right hypochondrium. Percutaneous drainage was performed,
and subsequent fistulography revealed a communication of the cystic cavity with
the right posterior bile duct, which suggested injury of the aberrant hepatic
duct. Conservative therapy, including the adaptation of fibrin glue, was
performed, but closure of the fistula and cavity was not obtainable. Finally, a
right hepatic lobectomy was performed four months after cholecystectomy. In this
case, endoscopic retrograde cholangiopancreatography was unsuccessful
preoperatively, and intraoperative cholangiography was not done. This case report
re-emphasizes that the preoperative and intraoperative examination of the biliary
tree is mandatory to avoid bile duct injury.
PMID- 10694081
TI - Laparoscopic placement of peritoneal dialysis catheter (same day dialysis).
AB - BACKGROUND AND OBJECTIVE: Peritoneal dialysis (PD) remains the generally accepted
method for management of renal failure in chronic and acute renal failure.
Despite the rapidly increasing use of continuous ambulatory peritoneal dialysis
(CAPD) since its introduction, controversy persists as to the efficacy and exact
role of the modality in the treatment of end stage renal failure. The aim of this
paper is to present the experience with laparoscopic placement of a peritoneal
dialysis catheter and starting the peritoneal dialysis on the same day. METHODS:
The laparoscopic placement of a peritoneal dialysis catheter was performed on 11
patients (10 males and 1 female) with an average age of 35 years, over a 12-month
period. The procedure was done using two 5 mm abdominal trocars. The precise
position of the catheter on the pelvis was ensured laparoscopically. One to two
liters exchange dialysis was used for every patient, and no leakage was recorded.
RESULTS: The patients tolerated the procedure well. The peritoneal dialysis was
started immediately. Patients were discharged after an overnight stay, and PD was
carried out routinely. CONCLUSION: The results of laparoscopic placement of a
peritoneal dialysis catheter show the following advantages: minimal incision;
less surgical trauma; the procedure hastens the early start of peritoneal
dialysis and has no complications.
PMID- 10694082
TI - Is the standard of care what we think it is?
AB - For the most part, gynecologists are actually unaware of the issues involving
surrogate versus quality of life outcomes, the "deceptive practice of medicine"
and the true incidence of complications as they relate to the standard of care.
An anonymous survey of 1958 practicing gynecologists attending seven national
symposia revealed a significant number of unreported complications. Clearly, the
standard of care (at least with regard to complication risk) is markedly
different than has been suggested by the medical literature. Concomitantly, we
suggest that physicians need to take a more active role in the policing of our
own specialties.
PMID- 10694083
TI - 27 months follow-up study of 41 women who underwent laparoscopic supracervical
hysterectomy.
PMID- 10694084
TI - Tuberculosis control strategies and utilitarianism.
PMID- 10694085
TI - Using other people's words.
PMID- 10694086
TI - A review of the diagnosis and treatment of smear-negative pulmonary tuberculosis.
AB - Recommendations on the management of smear-negative pulmonary tuberculosis (TB)
are still based on the behaviour of this disease in populations unaffected by the
human immunodeficiency virus (HIV). Studies prior to the HIV epidemic estimated
that there were 1.22 cases of smear-negative and extra-pulmonary TB for each
smear-positive case. Patients with smear-negative pulmonary TB were found to be
less infectious and to have a lower mortality, but a significant proportion (50%
71%) progressed to active disease justifying treatment. Moreover, a wide variety
of regimens also proved effective in the treatment of smear-negative disease in
HIV-negative patients. The advent of HIV has changed many of these parameters.
Countries affected by both HIV and TB have experienced a disproportionate
increase in smear-negative disease. While apparently remaining less infectious
than smear-positive cases, HIV-positive patients with smear-negative pulmonary TB
are generally more immunocompromised, have more adverse drug reactions, and
suffer higher mortality rates on treatment. Clinical decision-making has also
been complicated because HIV co-infection broadens the differential diagnoses of
smear-negative pulmonary TB to include diseases such as Pneumocystis carinii
pneumonia (PCP), pulmonary Kaposi's sarcoma, and Gram-negative bacteraemia. Our
approach to smear-negative pulmonary TB must therefore adapt to these changed
parameters. Management algorithms based on several features (clinical symptoms,
response to antibiotic trials, smear investigations, and chest radiography) have
been developed to improve case detection. These algorithms must be validated in
each locale because their performance will vary depending on numerous local
factors such as the regional prevalence of PCP. Alternative methods of specimen
collection, such as sputum induction, and processing must be evaluated. National
tuberculosis programmes should also consider extending the use of rifampicin
based short-course chemotherapy (SCC) to new patients with smear-negative
disease. This latter intervention, and the much-needed establishment of
additional microscopy and culture facilities, will depend on increased financial
and technical support from the international community.
PMID- 10694087
TI - Using treatment failure under effective directly observed short-course
chemotherapy programs to identify patients with multidrug-resistant tuberculosis.
AB - SETTING: Public ambulatory care centers in three districts of northern
metropolitan Lima, Peru. OBJECTIVE: To document drug resistance patterns of
isolates of Mycobacterium tuberculosis from patients identified as treatment
failures under a model tuberculosis (TB) control program based on directly
observed, short-course chemotherapy (DOT-SCC). DESIGN: Case series. RESULTS: In a
referred, consecutive sample of 173 patients identified as treatment failures on
DOT-SCC, 160 (92.5%) had culture-positive TB. Of those 160, 150 (93.8%) had
active, pulmonary multidrug-resistant TB (MDR-TB, resistance to at least
isoniazid [INH] and rifampicin [RIF]). Sixty of the 150 (40.0%) had isolates
resistant to at least INH, RIF, ethambutol (EMB) and pyrazinamide (PZA), the
initial first-line empiric treatment regimen used locally. Forty-four (29.3%) had
isolates resistant to at least INH, RIF, EMB, PZA and streptomycin (SM), the
first retreatment regimen. This series of patients had isolates resistant to a
mean of 4.5 of the ten drugs tested. The local profile of multidrug resistance is
very different from that obtained from national data from Peru. CONCLUSION: In
this setting, treatment failure on DOT-SCC is strongly predictive of active MDR
TB. Because of existing local drug resistance patterns in northern Lima, 89.3% of
MDR-TB patients identified as treatment failures will receive ineffective therapy
with two or fewer secondary TB drugs if they are given the five-drug empiric
retreatment regimen endorsed by the World Health Organization. Further short
course chemotherapy for these patients would only serve to amplify ominous
existing drug resistance patterns.
PMID- 10694088
TI - Anti-tuberculosis drug resistance in two clinics in Ecuador.
AB - SETTING: Two private hospitals, one in the capital city and one in the eastern
rainforest of Ecuador. OBJECTIVE: To document the prevalence of anti-tuberculosis
drug resistance in Ecuador in patients who had not received prior treatment and
in those who had. DESIGN: Drug resistance was determined using the proportion
method with solid medium on the first isolate of Mycobacterium tuberculosis from
all patients who attended the two hospitals between 1989 and 1996. Documentation
of prior treatment was obtained by patient interview. RESULTS: Resistance was
identified in 39 of 161 patients (24%) who had had no prior treatment. Resistance
was 14.2% to isoniazid, 11.8% to rifampin and 8.7% to both (multidrug-resistant
tuberculosis). Among 60 patients who had received prior treatment, 18 (30%) were
resistant to isoniazid, and 14 (23.3%) to rifampin, while multidrug resistance
was seen in 10 (16.7%). CONCLUSION: In these populations the prevalence of
resistance both in patients with no prior treatment and in patients with prior
treatment was ominously high. The initial treatment regimens and patient
management in Ecuador should be re-evaluated in an effort to prevent further
increases in drug resistance.
PMID- 10694089
TI - Rates and risk factors for discontinuation of rifampicin.
AB - SETTING: All patients with culture-confirmed, rifampin-susceptible Mycobacterium
tuberculosis diagnosed during a 20-month period in New York City, who were
started on a rifampin-containing regimen and received > or =60 days of treatment.
OBJECTIVE: To identify rates of and reasons for rifampin discontinuation. DESIGN:
Retrospective case-control study using surveillance data and medical record
reviews. Discontinuation due to thrombocytopenia, creatinine >2.0 mg/dl,
bilirubin >2.0 mg/dl or severe reactions (generalized rash, persistent drug
fever, or severe interference with methadone metabolism) were defined as
appropriate for discontinuation of rifampin. All other reactions were classified
as inappropriate. RESULTS: Of 3,520 patients, rifampin was discontinued in 68
(1.9%); of these, 57% had rifampin discontinued unnecessarily. Treatment by an
inexperienced provider (adjusted odds ratio [ORadj] 4.0; 95% confidence interval
[CI] 1.9-8.5), race (ORadj 3.1; 95%CI 1.4-6.9), history of previous treatment
(ORadj 4.8; 95%CI 1.9-12.5), and history of methadone drug treatment (ORadj 12.6;
95%CI 5.3-29.9) were all associated with inappropriate rifampin discontinuation.
CONCLUSION: True intolerance was rare, even among those patients infected with
the human immunodeficiency virus. Most patients with minor reactions can
successfully complete treatment with rifampin, particularly if managed by a
physician experienced in the treatment of tuberculosis.
PMID- 10694091
TI - Delay in tuberculosis case-finding and treatment in Mwanza, Tanzania.
AB - SETTING: Health facilities in Mwanza region, Tanzania. OBJECTIVE: To determine
factors responsible for delay from onset of symptoms of pulmonary tuberculosis to
initiation of treatment. DESIGN: A cross-sectional descriptive study of 296 smear
positive tuberculosis patients. Emphasis was given to periods between 1) onset of
symptoms and first consultation to a health facility, and 2) reporting to a
health facility and initiation of treatment. RESULTS: Mean total delay was 185
days (median 136), with nearly 90% of this being patient's delay. The mean health
system delay was 23 days (median 15), with longer delays in rural health
facilities. The mean patient's delay was 162 days (median 120). This delay was
significantly longer in rural areas, for patients with lower level of education,
for those who first visited a traditional healer, and for patients who had no
information on tuberculosis prior to diagnosis. Only 15% of the patients reported
to a health facility within 30 days of onset of symptoms. CONCLUSION: There are
significant delays in case-finding in Mwanza, Tanzania, with prolonged patient's
delay. Facilitation of utilisation of health services, raising awareness of the
disease and incorporation of private practice into tuberculosis control could
help to reduce these delays.
PMID- 10694090
TI - Gender and tuberculosis: a comparison of prevalence surveys with notification
data to explore sex differences in case detection.
AB - OBJECTIVE: To explore whether lower tuberculosis notification rates among women
are due to a reduced access to health care, particularly diagnostic services, for
women. METHODS: Age- and sex-specific tuberculosis prevalence rates of smear
positive tuberculosis were obtained from tuberculosis prevalence surveys reported
to the WHO or published in the literature. Age- and sex-specific notification
rates from the same countries in 1996 were used. RESULTS: Prevalence data and
notifications from 29 surveys in 14 countries were used. Notification rates
varied strongly among countries, but the female/male ratio was below 1 and
decreased with increasing age in almost all. The female/male (F/M) prevalence
ratios were less than 0.5 in surveys in the South-East Asia and Western Pacific
Region, and approximately 1 in the African Region. CONCLUSION: In most countries
the F/M sex ratio in prevalent cases was similar or lower than that in notified
cases, suggesting that F/M differences in notification rates may be largely due
to epidemiological differences and not to differential access to health care.
However, available data are limited as the prevalence surveys in Africa were
carried out many years ago, and in Asia notification rates may be distorted by a
large private sector with deficiencies in notification.
PMID- 10694092
TI - Lymph node biopsies in HIV-infected and non-infected children with persistent
lung disease.
AB - OBJECTIVE: The diagnosis of opportunistic infections in children with persistent
lung disease (PLD) who are infected with the human immunodeficiency virus (HIV)
is difficult to establish, especially in resource-poor countries. Lymphadenopathy
is a frequent associated clinical finding among these children. We evaluated the
usefulness of excision lymph node biopsies in determining an aetiological
diagnosis in HIV-infected and non-infected children with PLD. METHOD: Forty-five
children with PLD and significant lymphadenopathy were subjected to lymph node
biopsy. Of these, 27 were HIV-infected. All subjects had excision biopsies; 39
(86.7%) of these cases also underwent fine needle aspiration cytodiagnosis (FNAC)
and trucut needle biopsies. RESULTS: Tuberculosis was identified as the final
diagnosis in 11 (40.7%) and 12 (66.7%) HIV-infected and noninfected children,
respectively. Ancillary investigations (Mantoux, gastric washings) suggested a
diagnosis of tuberculosis in eight (72.7%) and eight (66.7%) of the final
diagnoses of tuberculosis among HIV-infected and non-infected children,
respectively. Lymph node biopsies identified a further three (27.3%) and four
(33.3%) more cases of tuberculosis as compared to ancillary investigations among
HIV-infected and non-infected groups, respectively. Results of FNAC and trucut
biopsy showed good correlation with excision biopsy: 96.4% and 97.4%,
respectively. However, adequate samples were obtained in only 23 of 39 FNAC and
33 of 39 trucut biopsies. CONCLUSION: Excision lymph node biopsies form a useful
adjunct investigation in children with PLD and generalised lymphadenopathy. The
most common disease identified among HIV-infected and non-infected children in
Durban, South Africa, is tuberculosis. FNAC and trucut biopsies may also be
useful in the evaluation of lymphadenopathy when appropriate specimens are
obtained.
PMID- 10694093
TI - Yield of gastric lavage and bronchial wash in pulmonary tuberculosis.
AB - OBJECTIVE: To determine the yield of acid-fast bacilli (AFB) in gastric lavage
and bronchial washing in adult patients clinically and radiologically suspected
of pulmonary tuberculosis but who cannot produce sputum. METHODS: Selected adult
patients were admitted to the ward; gastric lavage was done for 3 consecutive
days after an overnight fast followed by bronchial wash. Specimens were
immediately sent to laboratory for AFB direct smear and culture. RESULTS: The
yield of AFB in gastric lavage on direct smear was 16/20 (80%) and 12/20 (60%) in
the first and second samples, respectively. When combined, 18/20 (90%) were
direct smear positive, while the third sample did not increase the yield. The
yield of AFB culture in gastric lavage was 6/20 (30%) in both the first and
second samples, while the combined results of the first and second samples were
8/20 (40%). The third sample did not increase the yield. In bronchial wash, AFB
direct smear was positive in 18/20 (90%), while culture was positive in 14/20
(70%). CONCLUSION: Gastric lavage and bronchial washing are useful methods for
the diagnosis of pulmonary tuberculosis in patients who cannot produce sputum.
Two gastric lavage specimens are adequate. On comparison, bronchial wash is
superior to gastric lavage in culture, but their yield on direct smear is equal.
PMID- 10694094
TI - Analysis of circulating immune complexes (CICs) in childhood tuberculosis: levels
of specific antibodies to glycolipid antigens and relationship with serum
antibodies.
AB - BACKGROUND: The presence of specific antiglycolipid antibodies in serum and
circulating immune complexes (CIC) in children with tuberculosis was detected in
order to evaluate their contribution to the value of serodiagnosis of
tuberculosis, as has already been shown in adults. METHODS: ELISAs using the
three glycolipids LOS, DAT and PGLTb1 were performed in whole serum and immune
complexes from 20 children with tuberculous disease or infection, in seven child
contacts, and in 26 children with non-tuberculous disease. The contribution of
complexed IgG antibody to the diagnostic values was established for each group.
RESULTS: The antibody levels in free serum were higher (P < 0.01) in children
with tuberculous disease or infection and in contacts than in controls. By
contrast, except for PGLTb1, the IgG antibody levels were higher (P < 0.02) in
children with tuberculous disease than in the other groups. The highest
contribution of IgG antibody against LOS to the predictive values was shown in
children with pulmonary tuberculosis (positive predictive value 1,000, negative
predictive value 1,000). In paucibacillary tuberculosis (extra-pulmonary and
tuberculous infection) and in contacts, the IgG antibody did not contribute to
the sensitivity of the serodiagnosis, where the combination of antigens tested in
serum increased the diagnostic yield. The very low levels of IgG antibody in
these settings may indicate a different B cell response. CONCLUSION: The
detection of immune complexes and IgG antibodies against the three glycolipid
antigens is useful as a complementary technique for the serodiagnosis of children
with a high probability of pulmonary tuberculosis.
PMID- 10694095
TI - Mycobacterium tuberculosis lipid antigens: use of multi-antigen based enzyme
immunoassay for free and complex dissociated antibodies.
AB - OBJECTIVE: To test the sensitivity and specificity of four lipid antigens of
Mycobacterium tuberculosis: BDA-TDA, DAT, SL-I, and PIMs, adsorbed in the same
microplate well, to detect reactive IgG by enzyme-immunoassay (EIA) from plain
serum (MA-EIA) and dissociated immune complexes (ICMA-EIA). DESIGN: IgG
antibodies against four antigens, placed in the same microplate well, were
evaluated in serum from 155 tuberculous (TB) cases non-infected with the human
immunodeficiency virus (HIV): 78 patients with positive bacilloscopy and culture,
33 patients with positive culture and 44 patients diagnosed by clinical and
radiological criteria; and from 211 HIV negative control subjects: 32 patients
with other pulmonary diseases, 100 healthy people and 79 close contacts. RESULTS:
MA-EIA had an overall sensitivity and specificity of 61% (94/155) and 95%
(200/211), respectively. We further examined whether the dissociation of immune
complexes increases the number of positive reactions in those initially found to
be seronegative (SN). The subset of 112 (76 controls and 36 TB) MA-EIA SN samples
tested using ICMA-EIA yielded an overall sensitivity and specificity of 83% and
100%. The ICMA-EIA results improved the overall sensitivity from 61 to 80%
without changing specificity. CONCLUSION: These preliminary results suggest that
MA-EIA followed by ICMA-EIA, for SN samples, might serve as a fast, cheap, and
easy method for the diagnosis of TB in less than 48 hours.
PMID- 10694096
TI - Direct drug susceptibility test for tubercle bacilli by the sputum swab culture
method.
AB - OBJECTIVE: To develop a simple, inexpensive method for testing direct drug
susceptibility of tubercle bacilli to isoniazid (INH) and streptomycin (SM) which
can be adopted for use even in remote parts of the world. DESIGN: Using 239 smear
positive sputum specimens obtained from an equal number of patients, a comparison
was made between the direct swab susceptibility test and the standard indirect
method for INH and SM using Lowenstein-Jensen (L-J) medium. RESULTS: There was
95% agreement of results for INH by 6 weeks and 90% for SM by 8 weeks; 96% of INH
resistant cultures could be detected in 5 weeks and 91% of SM-resistant cultures
by 8 weeks. The discrepancies in the two tests were virtually symmetrically
distributed at 6 and 8 weeks. The speed and efficiency of detection of resistance
by the swab method was also assessed in relation to the standard indirect method.
For INH, 96% of the cultures were detected by the fifth week, while 66% were
detected as early as 2 weeks and 93% by 4 weeks. With SM, 84% were detected by 4
weeks, 89% by 5 weeks and 91% by 8 weeks. CONCLUSION: This study has indicated
the usefulness of the swab method for testing the drug susceptibility of tubercle
bacilli. As this method is simple and easy, and does not even require a
centrifuge, it has the potential of application even in the remote parts of the
world. The material used, Cetavlon (Cetrimide), is inexpensive and easily water
soluble, and more importantly, aqueous solutions are self-sterilizing. It should
be stressed, however, that the results obtained with this test take the same time
as conventional methods, and it can therefore not be considered as a rapid test.
PMID- 10694097
TI - Contribution of 'TB clubs' to tuberculosis control in a rural district in
Ethiopia.
AB - SETTING: A rural district (Estie) in South Gonder, Ethiopia. OBJECTIVE: To
describe the contribution of 'TB clubs' (small support groups of patients based
on where they live) to the performance of the tuberculosis control programme in
Estie District. DESIGN: A descriptive study of the formation of 'TB clubs', their
contribution to case-finding and the treatment outcomes before and after
formation of the 'TB clubs'. RESULTS: The proportion of actual among expected
attendances of tuberculosis patients for follow-up during treatment at health
facilities significantly increased (P < 0.001) after the introduction of the TB
clubs. Community elders, community health agents and local health workers helped
TB clubs to refer tuberculosis suspects, promote treatment adherence and trace
defaulters as an integral part of a district tuberculosis programme. The TB clubs
referred 181 tuberculosis suspects in the community for investigation, of whom
65% subsequently had a diagnosis of tuberculosis. TB clubs identified 69% of all
patients and 76% of new sputum smear-positive pulmonary patients diagnosed in the
district. Treatment success rates in new sputum smear-positive, smear-negative
and extra-pulmonary tuberculosis patients were 83%, 79% and 81%, respectively.
CONCLUSION: The formation of TB clubs contributed to the effective implementation
of a district tuberculosis programme. Further evaluation is needed to assess the
sustainability and applicability of the approach in other settings.
PMID- 10694098
TI - Evaluation of the polymerase chain reaction for the detection of Mycobacterium
tuberculosis.
AB - The development of nucleic acid-based technologies has improved the sensitivity,
specificity and speed of detection of Mycobacterium tuberculosis in clinical
samples. Both commercially available and 'in-house' polymerase chain reaction
(PCR) systems are in use, and a significant number of reports compare such
systems with more traditional diagnostic tools for tuberculosis. Few studies,
however, have focused on the reproducibility of the results when submitting a
sample batch to PCR in different laboratories, especially in developing
countries. Consequently, PCR results obtained from six laboratories in six
different Latin American countries for samples reconstituted with defined amounts
of M. tuberculosis cells were evaluated. Each laboratory used specific conditions
of sample processing, nucleic acid amplification and amplicon detection. Analysis
of results allowed large differences in sensitivity and specificity to be
observed. We conclude that in its present setting, in-house PCR cannot be used as
a single diagnostic tool for tuberculosis, and that special care needs to be
taken upon interpretation of results by inclusion of a proper number of positive
and negative controls.
PMID- 10694099
TI - Predictive values of the ICT Tuberculosis test for the routine diagnosis of
tuberculosis in Madagascar.
AB - The rapid commercialised ICT Tuberculosis test has been tested in Madagascar for
the diagnosis of smear-positive pulmonary (SM+) and extra-pulmonary tuberculosis
(EPT), using microscopy, culture and histopathology as reference tests.
Specificity was 83.3% and sensitivity 68.2% for SM+ patients and 65.2% for EPT
patients. With a prevalence of 22.2% for SM+ patients and 52.4% for confirmed EPT
among consulting patients in the National Reference Laboratory, the ICT
Tuberculosis assay was not sufficiently predictive for application in the
tuberculosis control programme.
PMID- 10694100
TI - Ordnung in das Chaos.
PMID- 10694101
TI - Study of primary drug resistance of Mycobacterium tuberculosis from two hospitals
in Tenerife, Canary Islands, Spain (1990-1997)
PMID- 10694102
TI - PAS infusion in treatment of multidrug-resistant tuberculosis.
PMID- 10694103
TI - Cardiac responses to progressive exercise in normal children: a synthesis.
AB - The cardiac responses to exercise are influenced by a complex interplay of
changes in diastolic filling, intrinsic myocardial contractility, heart rate, and
ventricular afterload. PURPOSE: To characterize these responses in children,
findings are reported from two studies utilizing Doppler echocardiographic
assessment of stroke volume and cardiac output during maximal upright and
semisupine cycle exercise. METHODS: In study 1, stroke volume, heart rate, and
peak aortic velocity were assessed during upright cycle exercise to exhaustion in
39 sixth-grade boys. In study 2, similar methods were used to examine cardiac
responses to semisupine exercise with measurement of left ventricular dimensions
by two-dimensional echocardiography. RESULTS: The findings support patterns
similar to that previously described in adults, with an initial rise in stroke
volume reaching a plateau at mild-moderate exercise intensities. CONCLUSIONS: The
observations in these two studies also suggest 1) peripheral vasodilatation plays
an important role in the early rise in stroke volume, 2) increasing heart rate
acts to maintain a stable stroke volume and left ventricular diastolic dimension
at high workloads, and 3) improvements in contractility serve to maintain stroke
volume as the systolic ejection period shortens.
PMID- 10694104
TI - The effects of ankle compliance and flexibility on ankle sprains.
AB - PURPOSE: The goal of this study was to examine the influence of changes in
subtalar joint flexibility and compliance on ankle sprain occurrence. METHODS:
Muscle model driven simulations of 10 subjects performing the landing phase of a
side-shuffle movement were performed. The passive flexibility or compliance of
the subtalar joint was varied, and each subject-specific simulation was exposed
to a set of perturbed floor conditions. RESULTS: Increases in flexibility and
compliance both led to an increase in the occurrence of excessive supination,
while changes in flexibility had a greater influence. Changes in flexibility or
compliance caused only small changes in the occurrence of excessive supination
torques. CONCLUSION: These results suggest that increased mechanical laxity does
not directly cause an increase in sprain occurrence during side-shuffle
movements.
PMID- 10694105
TI - Asthma and wheezing among Norwegian elite athletes.
AB - PURPOSE: The objectives were to estimate the prevalence of self-reports of asthma
and wheezing among Norwegian elite athletes compared with the general population
and to estimate the associations between asthma and types of sports, exercise and
team level. METHODS: The study population included all Norwegian elite athletes
on the national junior and senior teams in 1997 (N = 1620) and a random sample
from the general population (N = 1680). The surveys included items for asthma,
respiratory symptoms, the history of participation in sports, sports events, and
exercise and team level. The associations between the exposure variables and the
outcomes adjusting for potential confounding factors were estimated using
logistic regression. Crude (c) and adjusted odds ratio (aOR) with 95% confidence
interval (CI) are presented. RESULTS: The prevalence of asthma was greater among
athletes (10.0%) compared with that in the general population (6.9%) and remained
so after controlling for confounders, aOR = 1.5 (95%CI 1.1-2.1). The risk of
asthma was highest in sports requiring strength and endurance. This was the case
for comparisons between athletes and the general population, aOR = 3.5 (1.6-7.6)
for strength and aOR = 2.2 (1.4-3.5) for endurance sports. Comparisons within the
sample of athletes using technical sports as the reference category revealed
similar results, aOR = 3.0 (1.1-8.0) and aOR = 2.0 (1.0-4.3), respectively.
Furthermore, asthma was more common among female than male athletes (aOR 1.7 (1.1
2.7)). Training more than 20 h x wk(-1) was associated with asthma when compared
with levels of training less than 10 h x wk(-1) (aOR 1.9 (1.0-4.1)). CONCLUSION:
These results indicate that asthma is more common among athletes compared with
the general population. Asthma among athletes may define a subgroup of asthma
cases for whom etiology is related to extensive exercise.
PMID- 10694106
TI - A randomized trial of preexercise stretching for prevention of lower-limb injury.
AB - PURPOSE: This study investigated the effect of muscle stretching during warm-up
on the risk of exercise-related injury. METHODS: 1538 male army recruits were
randomly allocated to stretch or control groups. During the ensuing 12 wk of
training, both groups performed active warm-up exercises before physical training
sessions. In addition, the stretch group performed one 20-s static stretch under
supervision for each of six major leg muscle groups during every warm-up. The
control group did not stretch. RESULTS: 333 lower-limb injuries were recorded
during the training period, including 214 soft-tissue injuries. There were 158
injuries in the stretch group and 175 in the control group. There was no
significant effect of preexercise stretching on all-injuries risk (hazard ratio
[HR] = 0.95, 95% CI 0.77-1.18), soft-tissue injury risk (HR = 0.83, 95% CI 0.63
1.09), or bone injury risk (HR = 1.22, 95% CI 0.86-1.76). Fitness (20-m
progressive shuttle run test score), age, and enlistment date all significantly
predicted injury risk (P < 0.01 for each), but height, weight, and body mass
index did not. CONCLUSION: A typical muscle stretching protocol performed during
preexercise warm-ups does not produce clinically meaningful reductions in risk of
exercise-related injury in army recruits. Fitness may be an important, modifiable
risk factor.
PMID- 10694107
TI - Anaerobic performance in 5- to 7-yr-old children of low birthweight.
AB - PURPOSE: This study was intended to determine whether anaerobic muscle
performance is deficient in 5- to 7-yr-old children of extremely low birthweight
(ELBW, 500-999 g) and very low birthweight (VLBW, 1000-1499 g). METHODS: Fourteen
ELBW and 20 VLBW children were compared with 24 normal birthweight (NBW, >2500 g)
term controls. Peak (PP) and mean (MP) muscle power were determined by the
Wingate anaerobic test. Bioimpedance analysis and anthropometry were done to
assess fat-free mass (FFM) and lean cross-sectional area of the thigh and calf.
RESULTS: The ELBW group had significantly lower MP and PP, compared with the VLBW
and, in particular, with the NBW group. This lower performance was apparent also
when values were corrected for total body mass (MP) and FFM (MP and PP), but not
when corrected for cross-sectional area of thigh and calf. CONCLUSION: The lower
anaerobic muscle performance in ELBW children may be partly due to their smaller
muscle mass, but may also reflect a low percentage of fast-twitch muscle fibers,
low muscle phosphagen content, or deficiency in motor control.
PMID- 10694108
TI - Influence of intra-oral maxillary sports mouthguards on the airflow dynamics of
oral breathing.
AB - PURPOSE: Mouthguards worn during sporting competition may influence oral airway
flow dynamics and potentially increase airflow resistance during mouth breathing.
METHODS: We measured oral airflow resistance (RO) in 10 normal subjects (four
men, six women, age 29 +/- 3 yr, mean +/- SEM) wearing two different custom-made
maxillary mouthguards. RESULTS: During tidal mouthpiece breathing (jaw position
controlled), inspiratory R(O) (at (1.4 L x s(-1)) increased from 0.22 (0.15-0.46)
cm H2O x L(-1) x s(-1) (median and interquartile range) to 0.47 (0.24-0.52) cm
H2O x L(-1) x s(-1) with mouthguard 1 (general sports mouthguard) and from 0.34
(0.27-0.51) to 0.46 (0.39-0.86) cm H2O x L(-1) x s(-1) (N = 8) with mouthguard 2
(laminated, field hockey mouthguard, both P < 0.05). With oral only mask
breathing (jaw position not controlled), inspiratory R(O) (at 0.4 L x s(-1))
increased to 1.02 (0.42-1.57) cm H2O x L(-1) x s(-1) (P < 0.03, compared with
mouthpiece) but was variably affected by both mouthguards. At 1.0 L x s(-1),
there was a tendency for both mouthguards to increase inspiratory R(O); however,
this effect only reached significance for mouthguard 1 during mouthpiece
breathing. CONCLUSION: Thus, although maxillary mouthguards do increase R(O) when
jaw position is controlled, individual subjects respond differently when in
control of mouth opening. This may be related to variable recruitment of
compensatory mechanisms (e.g. mouth opening and/or oral airway dilator muscle
activity).
PMID- 10694109
TI - Acute creatine loading increases fat-free mass, but does not affect blood
pressure, plasma creatinine, or CK activity in men and women.
AB - Creatine monohydrate (CrM) administration may enhance high intensity exercise
performance and increase body mass, yet few studies have examined for potential
adverse effects, and no studies have directly considered potential gender
differences. PURPOSE: The purpose of this study was to examine the effect of
acute creatine supplementation upon total and lean mass and to determine
potential side effects in both men and women. METHODS: The effect of acute CrM
(20 g x d(-1) x 5 d) administration upon systolic, diastolic, and mean BP, plasma
creatinine, plasma CK activity, and body composition was examined in 15 men and
15 women in a randomized, double-blind experiment. Additionally, ischemic
isometric handgrip strength was measured before and after CrM or placebo (PL).
RESULTS: CrM did not affect blood pressure, plasma creatinine, estimated
creatinine clearance, plasma CK activity, or handgrip strength (P > 0.05). In
contrast, CrM significantly increased fat-free mass (FFM) and total body mass (P
< 0.05) as compared with PL, with no changes in body fat. The observed mass
changes were greater for men versus women. CONCLUSIONS: These findings suggest
that acute CrM administration does not affect blood pressure, renal function, or
plasma CK activity, but increases FFM. The effect of CrM upon FFM may be greater
in men as compared with that in women.
PMID- 10694110
TI - Estrogen variation and resting left ventricular structure and function in young
healthy females.
AB - PURPOSE: A potential confounding factor in the interpretation of left ventricular
(LV) structural and functional data in female subjects could be menstrual phase
or contraceptive use upon assessment. To date no study has addressed this issue.
METHODS: Seventeen eumenorrheic (EU; mean +/- SD age = 21 +/- 3 yr) and 14
combined-oral contraceptive pill-using (COC: mean +/- SD age = 21 +/- 3 yr)
females volunteered to participate. The EU had stable menstrual cycles and the
COC had all been using the same pill preparation for a minimum of 6 months.
Echocardiographic examinations occurred during the mid-follicular phase and mid
luteal phases in the EU and during mid-consumption and mid-end of withdrawal in
the COC. LV structure and function were assessed using M-mode and pulsed-wave
Doppler echocardiography. Data were compared via Student t-tests and limits of
agreement (LoA) were calculated. RESULTS: Structure and function did not
significantly differ between phases of the menstrual cycle or between consumption
and withdrawal of oral contraception (P > 0.05). However, there was considerable
variance in the LoA between variables. Smaller LoA were reported for those
variables directly measured from echocardiograms compared with those from derived
data. For example, in a measured variable such as LV internal dimension in
diastole, the LoA data represented a variation of +/- 0.4 mm (+/- 1%) between
phases. Conversely, data for LV mass, a derived variable, reported LoA values of
+/- 15 g (10%) between phases. The LoA were consistent between EU and COC.
Variation in both measured and derived variables were within, or close to,
accepted limits of measurement or biological error. CONCLUSION: It would seem
that in studies assessing LV structure and function in women the influence of
menstrual phase or oral contraceptive use is of minor significance.
PMID- 10694111
TI - Effect of a neoprene sleeve on knee joint kinesthesis: influence of different
testing procedures.
AB - PURPOSE: Objectives of this study were to examine the perceived sense of knee
joint position during selected test situations, and to evaluate the proposed
kinesthetic effect of a neoprene knee sleeve during these test situations.
METHODS: Fifty-nine young healthy subjects (39 females and 20 males) attempted to
replicate target knee joint angles using active and passive knee extension
movements completed in sitting (nonaxially loaded) situations, and during active
knee extension movements completed in supine while applying a load of 15% body
weight through the long axis of the tibia (axially loaded). The criterion measure
used was the absolute difference between target and reproduced angles, averaged
over five attempts (Average absolute difference: AAD). RESULTS: A three-way ANOVA
(two genders by three test situations by two sleeve conditions), with repeated
measures on the last two factors, indicated a significant main effect for test
situation and sleeve condition (P < 0.05), but not for gender. There was also a
significant test situation by sleeve condition interaction (P < 0.05). Post-hoc
analysis indicated that the AAD score during the active nonaxially loaded test
situation without the sleeve was significantly greater than AAD scores for all
other tests (P < 0.01). CONCLUSIONS: Pre-existing differences in knee joint
kinesthesis observed during different contexts of limb movement must be
recognized before various interventions, including the effect of knee supports,
can be adequately interpreted. Because knee joint position sense was attenuated
during voluntary active movement, and because this attenuation was ameliorated by
the use of a sleeve, future studies evaluating the kinesthetic effects of knee
bracing may benefit from using active movements. However, since the sleeve did
not affect performance during the axially loaded test situation, future studies
should also evaluate the relationship between tests of knee joint kinesthesis and
other more functional tests of neuromuscular performance.
PMID- 10694112
TI - Exercise-induced asthma screening of elite athletes: field versus laboratory
exercise challenge.
AB - PURPOSE: The purpose of this study was to compare a laboratory based exercise
challenge (LBC) to a field based exercise challenge (FBC) for pulmonary function
test (PFT) exercise-induced asthma (EIA) screening of elite athletes. METHODS:
Twenty-three elite cold weather athletes (14 men, 9 women) PFT positive for EIA
(FBC screened) served as subjects. Twenty-three gender and sport matched controls
(nonasthmatics) were randomly selected to establish PFT reference values for
normal elite athletes. Before FBC, athletes completed a medical history
questionnaire for EIA symptoms. FBC evaluations consisted of baseline spirometry,
actual or simulated competition, and 5, 10, and 15 min postexercise spirometry.
PFT positive athletes were evaluated in the laboratory using an exercise
challenge simulating race intensity (ambient conditions: 21 degrees C, 60%
relative humidity). PFT procedures were identical to FBC. RESULTS: 91% of PFT
positive and 48% of PFT normal athletes reported at least one symptom of EIA,
with postrace cough most frequent. Baseline spirometry was the same for PFT
positives and normal controls. Lower limit reference range (MN - 2 SD) of FEV1
for controls suggests that postexercise decrements of greater than approximately
7% indicate abnormal airway response in this population. Exercise time duration
did not effect bronchial reactivity; 78% of FBC PFT positives were PFT normal
post-LBC. CONCLUSION: Self-reported symptoms by elite athletes are not reliable
in identifying EIA. Reference range criterion for FEV1 decrement in the elite
athlete postexercise contrasts current recommended guidelines. Moreover, a large
number of false negatives may occur in this population if EIA screening is
performed with inadequate exercise and environmental stress.
PMID- 10694113
TI - Cytokine hypothesis of overtraining: a physiological adaptation to excessive
stress?
AB - Overtraining syndrome (OTS) is a condition wherein an athlete is training
excessively, yet performance deteriorates. This is usually accompanied by
mood/behavior changes and a variety of biochemical and physiological alterations.
Presently, there is no global hypothesis to account for OTS. The present paper
will attempt to provide a unifying paradigm that will integrate previous research
under the rubric of the cytokine hypothesis of overtraining. It is argued that
high volume/intensity training, with insufficient rest, will produce muscle
and/or skeletal and/or joint trauma. Circulating monocytes are then activated by
injury-related cytokines, and in turn produce large quantities of proinflammatory
IL-1beta, and/or IL-6, and/or TNF-alpha, producing systemic inflammation.
Elevated circulating cytokines then co-ordinate the whole-body response by: a)
communicating with the CNS and inducing a set of behaviors referred to as
"sickness" behavior, which involves mood and behavior changes that support
resolution of systemic inflammation: b) adjusting liver function, to support the
up-regulation of gluconeogenesis, as well as de novo synthesis of acute phase
proteins, and a concomitant hypercatabolic state; and c) impacting on immune
function. Theoretically, OTS is viewed as the third stage of Selye's general
adaptation syndrome, with the focus being on recovery/survival, and not
adaptation, and is deemed to be "protective," occurring in response to excessive
physical/physiological stress. Recommendations are made for potential markers of
OTS, based on a systemic inflammatory condition.
PMID- 10694114
TI - Blood volume: importance and adaptations to exercise training, environmental
stresses, and trauma/sickness.
AB - This paper reviews the influence of several perturbations (physical exercise,
heat stress, terrestrial altitude, microgravity, and trauma/sickness) on
adaptations of blood volume (BV), erythrocyte volume (EV), and plasma volume
(PV). Exercise training can induce BV expansion: PV expansion usually occurs
immediately, but EV expansion takes weeks. EV and PV expansion contribute to
aerobic power improvements associated with exercise training. Repeated heat
exposure induces PV expansion but does not alter EV. PV expansion does not
improve thermoregulation, but EV expansion improves thermoregulation during
exercise in the heat. Dehydration decreases PV (and increases plasma tonicity)
which elevates heat strain and reduces exercise performance. High altitude
exposure causes rapid (hours) plasma loss. During initial weeks at altitude, EV
is unaffected, but a gradual expansion occurs with extended acclimatization. BV
adjustments contribute, but are not key, to altitude acclimatization.
Microgravity decreases PV and EV which contribute to orthostatic intolerance and
decreased exercise capacity in astronauts. PV decreases may result from lower set
points for total body water and central venous pressure, while EV decreases may
result from increased erythrocyte destruction. Trauma, renal disease, and chronic
diseases cause anemia from hemorrhage and immune activation which suppresses
erythropoiesis. The re-establishment of EV is associated with healing, improved
life quality, and exercise capabilities for these injured/sick persons.
PMID- 10694115
TI - Left ventricular morphology in junior and master resistance trained athletes.
AB - PURPOSE: The objective of this cross-sectional investigation was to assess the
effects of short (< 5 yr) versus long-term (> or = 18 yr) resistance training
(RT) on left ventricular (LV) dimensions and mass. METHODS: The subjects for this
study were 20 elite male powerlifters (8 junior athletes [JA], mean +/- SD, age:
21.1 +/- 1.2 yr and 12 master athletes [MA], age: 46.0 +/- 5.5 yr) and 19 age
matched male controls (8 young controls [YC], age: 21.8 +/- 2.8 yr and 11 middle
aged controls [MAC], age: 46.8 +/- 4.4 yr). Two-dimensionally guided
transthoracic M-mode echocardiograms were performed at rest to quantify LV
systolic and diastolic cavity dimension (LVIDs and LVIDd, respectively),
ventricular septal wall thickness (VST), posterior wall thickness (PWT), LV mass
(LVM), and LV systolic function as measured as fractional shortening (FS).
RESULTS: Short- or long-term RT was not associated with a significant alteration
in LVIDd (JA: 53.2 +/- 4.5 mm, YC: 52.1 +/- 3.7 mm, MA: 53.0 +/- 5.1 mm, MAC:
51.8 +/- 4.4 mm), LVIDs (JA: 33.5 +/- 4.8 mm, YC: 32.9 +/- 3.4 mm, MA: 33.0 +/-
4.4 mm, MAC: 31.4 +/- 3.7 mm), VST (JA: 9.4 +/- 0.9 mm, YC: 9.4 +/- 0.9 mm, MA:
9.4 +/- 1.6 mm, MAC: 9.7 +/- 0.9 mm), PWT (JA: 9.2 +/- 0.9 mm, YC: 9.4 +/- 0.9
mm, MA: 9.0 +/- 1.1 mm, MAC: 9.5 +/- 1.0 mm), LVM (JA: 184.6 +/- 36.1 g, YC:
179.0 +/- 26.5 g, MA, 183.3 +/- 58.1 g, MAC: 184.1 +/- 38.1 g), or FS (JA: 0.37
+/- 0.1%, YC: 0.37 +/- 0.05%, MA: 0.38 +/- 0.1%, MAC: 0.40 +/- 0.04%).
CONCLUSIONS: These findings suggest that short or long-term RT as performed by
elite junior and master powerlifters does not alter LV morphology or systolic
function.
PMID- 10694116
TI - Physical activity, cardiorespiratory fitness, and the primary components of blood
viscosity.
AB - PURPOSE: The relationship of both self-reported leisure time physical activity
(LTPA) and predicted maximum oxygen consumption (VO2max) with plasma viscosity
and hematocrit (Hct) concentration was examined within a cross-sectional sample
of employed middle-aged men. METHODS: Analyses were performed on a subsample of
nonsmoking men who completed a preventive medical assessment between 1992-1996.
RESULTS: Among nonsmokers the mean age-adjusted levels of plasma viscosity (N =
590) and Hct concentration (N = 632) were significantly lower with higher
Physical Activity Index (PAI) categories (P = 0.001 and P = 0.01, respectively).
Following adjustment for conventional IHD risk factors and blood leukocyte count,
a significant inverse relationship remained for Hct (P = 0.044) but not plasma
viscosity. Mean age-adjusted plasma viscosity and Hct concentration also showed a
significant decrease with higher quartiles of predicted VO2max (mL x kg(-1) x
min(-1))(P = < 0.00005 and P = 0.0004, respectively). Following adjustment for
all confounding variables mean plasma viscosity and Hct concentration remained
significantly lower with higher quartiles of predicted VO2max (mL x kg(-1) x min(
1))(P = < 0.00005 and P = 0.047). CONCLUSIONS: These data confirm the inverse
relationship between LTPA and/or predicted VO2max with plasma viscosity and Hct
concentration within nonsmoking middle-aged men of high socioeconomic status.
PMID- 10694117
TI - Effects of prior exercise on eccentric exercise-induced neutrophilia and enzyme
release.
AB - PURPOSE: The purpose of this study was to determine the effects of prior exercise
on changes in circulating neutrophils, neutrophil activation, and myocellular
enzymes following a standardized bout of eccentric exercise. METHODS: Twenty-four
male volunteers were randomized into three groups (N = 8). Group C performed 10
sets of 10 eccentric contractions of the quadriceps muscles with both legs (100%
of the concentric IRM). Group D and Group F exercised for 2 h at 56%VO2max on a
cycle ergometer followed by a similar bout of eccentric contractions. Group F
also received 7.5 mL x kg(-1) of a carbohydrate-electrolyte beverage every 30 min
during the submaximal exercise, whereas group D received no fluid. RESULTS: Body
weight remained unchanged in groups C and F and decreased in group D by 1.56 +/-
0.34 kg. Ultrastructural Z-Band damage increased three-fold following exercise
and remained elevated 3 d after exercise but was not different among groups.
Circulating neutrophils were elevated more in group D compared with those in
group C immediately after the exercise or rest period, and this difference
persisted 3 h after the eccentric exercise. Serum lactoferrin concentrations
increased 3.3-fold after exercise in all groups (P < 0.01). Creatine kinase
levels (CK) rose in all subjects, with subjects in Group F and D having a
significantly greater rise in CK after exercise compared with those in group C.
CONCLUSIONS: These data indicate that submaximal exercise followed by a bout of
eccentric exercise results in similar amounts of myofibrillar injury with a
larger neutrophil response and CK release.
PMID- 10694118
TI - Induction of mitochondrial stress proteins following treadmill running.
AB - PURPOSE: The purpose of this investigation was to examine the relationship
between the expression of HSP60 and GRP75 and the oxidative potential of skeletal
muscle as assessed by the citrate synthase activity following endurance training
to sedentary controls. METHODS: Female Wistar rats were assigned to one of two
groups: sedentary controls (N = 8) or endurance trained (N = 9). Endurance
trained rats were run 60 min x d(-1) at 27 m x min(-1) up a 10% incline 6 d x wk(
1) for 8 wk on a motor-driven treadmill. RESULTS: Training produced a 47%
increase in citrate synthase activity along with a 103% increase in the
expression of HSP60 and a 105% increase in the expression of GRP75 in plantaris
muscle. In addition, there was a significant correlation between the citrate
synthase activity and expression of HSP60 found in plantaris muscle. CONCLUSIONS:
These findings are consistent with the hypothesis that the adaptive response to
treadmill running may require elevations in the expression of HSP60 and GRP75 to
support protein import and folding.
PMID- 10694119
TI - Plasma creatine kinase responses of 18- to 30-yr-old African-American men to
eccentric exercise.
AB - PURPOSE: The primary aim was to describe the response of plasma creatine kinase
(CK) activity in a sample of African-American men after a bout of eccentric
exercise. The study also described signal intensity changes detected by MR in the
musculature of the right lower leg. METHODS: Subjects were 20 male volunteers of
African descent (age = 24 +/- 4 [mean +/- SD] yr). Each walked backward for 60
min at 3 km x h(-1) down a 23% grade. Venous blood was sampled before exercise,
immediately (0 d) after and 1, 2, 4, and 7 d after exercise for plasma CK assay.
Soreness in the plantar flexor muscles was evaluated in 18 subjects at selected
times during the 7 d postexercise. Injury to the plantar flexor muscles was
evaluated by magnetic resonance imaging (MRI). RESULTS: The subjects had high
baseline plasma CK activity (187 +/- 127 IU x L(-1); 163 +/- 70 IU x L(-1) with
one outlier excluded) compared with typical clinical norms. As a group, CK
activity was increased (P < 0.05) 4 d (980 +/- 1331 IU L(-1)) and 7 d (1022 +/-
1031 IU L(-1)) postexercise, compared with preexercise. Eleven (55%) of the
subjects had large, delayed increases in plasma CK activity ("hyperresponses").
As a group, the plasma CK response was similar to responses of comparison
Caucasian subjects. All subjects reported delayed muscle soreness; there was no
association between soreness and plasma CK. Every subject showed MRI evidence of
injury to plantar flexor muscles postexercise but varying in degree and time
course. Plasma CK activity correlated to MRI signal intensity (rho = 0.445).
CONCLUSION: Results suggest that changes in plasma CK activity and skeletal
muscle injury in African-American men after eccentric exercise do not differ from
the responses of Caucasians.
PMID- 10694120
TI - Creatine enhances oxygen uptake and performance during alternating intensity
exercise.
AB - PURPOSE: The main purpose of the present study was to measure the total oxygen
consumed, accumulation of blood metabolites, and performance during alternating
intensity exercise before and after a period of creatine (Cr) loading in well
trained humans. METHODS: Fourteen males were randomly assigned to two groups of
seven males and were tested before and after 5 d of placebo (PL) or Cr
monohydrate (CR) loading (20 g x d(-1)). Oxygen uptake was measured using a
breath-by-breath system during bicycle exercise alternating every 3 min between
bouts at 30%(-30%) and 90% (-90%) of the maximal power output to exhaustion.
Blood samples were also obtained at rest, before the end of each cycling load, at
exhaustion, and 5-min postexercise. RESULTS: The oxygen consumed during 1-90%
(5.08 +/- 0.39 L) and 2-90% (5.32 +/- 0.30 L) was larger after CR (5.67 +/- 0.34
and 5.78 +/- 0.35 L, P < 0.01 and P < 0.05, respectively). Blood ammonia
accumulation at the end of 1-90% (23.1 +/- 6.5 micromol x L(-1)) and 3-30% (64.7
+/- 15.2 micromol x L(-1)) was lower after CR (P < 0.05), whereas plasma uric
acid accumulation was lower at exhaustion (P < 0.05) and 5-min postexercise (P <
0.01). Time to exhaustion increased (P < 0.05) from 29.9 +/- 3.8 to 36.5 +/- 5.7
min after CR, whereas it remained the same after PL. CONCLUSIONS: The results
indicate that Cr feeding increases the capacity of human muscle to perform work
during alternating intensity contraction, possibly as a consequence of increased
aerobic phosphorylation and flux through the creatine kinase system.
PMID- 10694121
TI - Effects of abstinence from cigarette smoking on the cardiorespiratory capacity.
AB - PURPOSE: The purpose of this study was to determine the effect of 6 or 7 d of
abstinence from cigarette smoking on the cardiorespiratory capacity of young men.
METHODS: The subjects were 11 male volunteers, mean age 20.5 yr. Their mean
smoking duration and cigarettes smoked per day were about 3.5 yr and 20.5
cigarettes, respectively. On the first day of the study, the subjects' physical
characteristics, pulmonary functions, and maximal oxygen debt predicted by
bicycle ergometer exercise were measured. The subjects' heart rate at rest
(HRrest), blood pressure, venous blood analysis and maximal oxygen intake
(VO2max) in a treadmill exercise test were measured on the second day. From the
time of the second-day measurements, the subjects abstained from cigarette
smoking. On the eighth and ninth days of the study, the same measurements were
taken as the measurements of the first and second days, respectively. RESULTS:
The changes between before and after abstinence from smoking were as follows. The
plasma cotinine had almost disappeared after the 7 d of abstinence from smoking.
Pulmonary functions did not show a significant improvement. Although there were
no significant changes in the HRrest or systolic or diastolic blood pressure, the
pulse pressure was significantly increased (P < 0.05). Although the blood
components were not changed significantly, the PO2, O2 saturation, HCO3, and CO2
concentration were significantly increased. The predicted maximal oxygen debt was
not significantly decreased. Although the VO2max and maximal ventilation volume
were not changed, the exercise time was significantly prolonged (P < 0.001). The
heart rate during the treadmill exercise at almost all stages decreased
significantly; however, the maximal heart rate did not change. CONCLUSION: In
conclusion, exercise performance was improved by the 7 d of abstinence from
smoking.
PMID- 10694122
TI - The association between vigorous physical activities and fat deposition in male
adolescents.
AB - PURPOSE: The aim of this study was to investigate the association between
participation in vigorous physical activities (VPA) and indicators of adiposity
and fat distribution in male adolescents. METHODS: Subjects were classified on
the basis of the number of reported 15-min periods over 3 d during which VPA were
performed. RESULTS: Body weight, fat mass, body mass index, sum of six
subcutaneous skinfolds, trunk and extremity skinfolds, and trunk to extremity
skinfolds ratio (T/E ratio) were all significantly and inversely related to a
higher VPA participation. Moreover, T/E ratio was significantly lower in the
subgroup reporting a mean of 7.8 15-min periods of activity for 3 d (equivalent
to a mean of 39 min x d(-1)) compared with subjects reporting no participation.
This decrease in T/E ratio was more pronounced in subjects reporting a mean of
13.6 15-min periods of VPA for 3 d. CONCLUSION: These observations reinforce the
idea that excess abdominal fat accumulation can be prevented by regular
participation in vigorous physical activities.
PMID- 10694123
TI - Effect of mild dehydration on the lactate threshold in women.
AB - PURPOSE: The purpose of this investigation was to examine the effects of
dehydration on the lactate threshold and performance time to exhaustion in women.
METHODS: Seven moderately trained women (age = 23.6 +/- 1.6 yr) performed two
graded exercise tests on separate occasions, once in a normally hydrated state
(HY) and once in a dehydrated state (DE). Dehydration was achieved by a 45-min
submaximal exercise the evening before testing, followed by a 12-h period of
fluid restriction. VO2, VCO2, V(E), R-values, blood lactate, and catecholamine
concentrations were measured at baseline and during each workload. Plasma volume
and plasma osmolality were also determined. Body weight dropped significantly for
the dehydrated trial (2.6 +/- 0.7%). RESULTS: There was a corresponding decrease
in plasma volume measured (3.5 +/- 2.6%). The VO2max (3.1 +/- 0.3 L x min(-1) HY;
3.0 +/- 0.1 L x min(-1) DE) obtained was not significantly different between the
hydration and dehydration trial. Plasma norepinephrine, epinephrine, and lactate
concentrations were not significantly different at baseline or maximum intensity
although epinephrine concentrations were higher for the dehydrated trial during
submaximal workloads. Lactate concentrations were highly correlated with
epinephrine (r = 0.95 HY; r = 0.97 DE). The lactate threshold occurred at a
significantly lower relative percent of VO2max for the dehydrated trial (72.2 +/-
1.1% HY; 65.5 +/- 1.8% DE) as well as a lower absolute power output when compared
with that in the hydrated trial. There was a significant decrease in time to
exhaustion for the dehydrated trial (17.3 +/- 0.7 min HY; 16.3 + 0.7 min DE).
Time to exhaustion for the dehydrated trial was correlated with the % VOmax at
which the lactate threshold occurred (r = 0.74). CONCLUSIONS: These data indicate
that low levels of dehydration induced a shift in the lactate threshold, in part
because of elevated epinephrine concentrations. This shift may have been one
cause for the decrease in time to exhaustion for the dehydrated trial.
PMID- 10694124
TI - Postactivation potentiation in endurance-trained male athletes.
AB - PURPOSE: The purpose of the study was to determine whether postactivation
potentiation (PAP) was enhanced in the trained muscles of male endurance
athletes. METHODS: Triathletes (TRI), distance runners (RUN), active controls
(AC), and sedentary control subjects (SED) (N = 10 per group) performed 10-s
maximal isometric contractions (MVC) of the elbow extensor and ankle
plantarflexor muscles. Maximal twitch contractions were evoked (percutaneous
stimulation) before and during a 5-min period after the MVC. PAP was measured as
the percentage change in peak twitch torque post-MVC. RESULTS: TRI, who train
both upper and lower limb muscles, had enhanced (relative to SED) PAP in both
elbow extensor and plantarflexor muscles. In RUN, who train only the lower limbs,
enhanced PAP was restricted to the plantarflexors. AC, whose main activity was
upper and lower limb weight training, also had enhanced PAP in both muscle
groups, although the enhancement in the plantarflexors was not as great as in TRI
and RUN. CONCLUSION: PAP is enhanced in endurance athletes. Enhanced PAP may
counteract fatigue during endurance exercise. The mechanism(s) responsible for
the enhanced PAP remain to be determined.
PMID- 10694125
TI - Muscular strength and physical function.
AB - PURPOSE: The purpose of this study was to evaluate the potential association of
muscular strength and endurance at baseline with the prevalence of functional
limitations at follow-up. METHODS: Study participants were 3,069 men and 589
women (30-82 yr) who received a clinical examination including a strength
evaluation at the Cooper Clinic between 1980 and 1989 and responded to a 1990
mail-back survey. Participants also had to achieve at least 85% of their age
predicted maximal heart rate on a maximal exercise treadmill test and have no
history of heart attack, stroke, diabetes, high blood pressure, cancer, or
arthritis at their first visit. A strength index composite score (0-6) was
calculated using age- and sex-specific tertiles from bench press, leg press, and
sit-up tests. Those scoring 5 or 6 were categorized in the high strength group.
Functional health status was assessed by responses to questions about the
participant's ability to perform light, moderate, and strenuous recreational,
household, daily living, and personal care tasks. RESULTS: After an average
follow-up of 5 yr, 7% of men and 12% of women reported at least one functional
limitation. A logistic regression model including age, aerobic fitness, body mass
index, and new health problems at follow-up found that, relative to those with
lower levels of strength, the odds of reporting functional limitations at follow
up in men and women categorized as having higher levels of strength were 0.56
(95%CI = 0.34, 0.93) and 0.54 (95%CI = 0.21, 1.39), respectively. CONCLUSIONS:
These findings, if replicated in other populations, suggest that maintenance of
strength throughout the lifespan may reduce the prevalence of functional
limitations.
PMID- 10694126
TI - Leisure-time physical activities and their relationship to cardiorespiratory
fitness in healthy men and women 18-95 years old.
AB - PURPOSE: We examined leisure-time physical activities (LTPA) and their
contribution to peak oxygen consumption (VO2) in healthy men (N = 619) and women
(N = 497) aged 18-95 yr (mean 51 +/- 17) who were participants of the Baltimore
Longitudinal study of Aging. METHODS: Calculations of LTPA were based on the
average self-reported time spent performing 97 activities and converted into MET
min x 24 h(-1). The activities were divided into three levels of LTPA based on
absolute intensity. Peak VO2 was determined from a maximal treadmill exercise
test. RESULTS: Total LTPA was inversely related to age in both sexes (r = -0.26,
P < 0.0001 in men and r = -0.23, P < 0.0001 in women), mediated primarily by less
high-intensity activities in older subjects, with only minor differences in
moderate- and low-intensity activities across age. Peak VO2 correlated positively
with LTPA; the correlations were strongest for high-intensity LTPA (r = 0.33 in
men and 0.27 in women, each P < 0.0001), intermediate for moderate-intensity
activity (r = 0.12, P < 0.004 in men and r = 0.17, P < 0.0001 in women) and
minimal for low-intensity activity (r = 0.08, P = 0.05 in men and r = 0.06, P =
0.20 in women). On univariate analysis, total LTPA accounted for 12.9% of peak
VO2 variance for men and 10.6% for women. By multivariate analysis, LTPA
independently accounted for 1.6% of the peak VO2 variance in men and 1.8% in
women after controlling for age and body mass index. CONCLUSIONS: In healthy
adults across a broad age range, LTPA is a relatively minor independent
contributor to aerobic capacity.
PMID- 10694127
TI - Using objective physical activity measures with youth: how many days of
monitoring are needed?
AB - PURPOSE: The purpose of this study was to establish the minimal number of days of
monitoring required for accelerometers to assess usual physical activity in
children. METHODS: A total of 381 students (189 M, 192 F) wore a CSA 7164
uniaxial accelerometer for seven consecutive days. To examine age-related trends
students were grouped as follows: Group I: grades 1-3 (N = 92); Group II: grades
4-6 (N = 98); Group III: grades 7-9 (N = 97); Group IV: grades 10-12 (N = 94).
Average daily time spent in moderate-to-vigorous physical activity (MVPA) was
calculated from minute-by-minute activity counts using the regression equation
developed by Freedson et al. (1997). RESULTS: Compared with adolescents in grades
7 to 12, children in grades 1 to 6 exhibited less day-to-day variability in MVPA
behavior. Spearman-Brown analyses indicated that between 4 and 5 d of monitoring
would be necessary to a achieve a reliability of 0.80 in children, and between 8
and 9 d of monitoring would be necessary to achieve a reliability of 0.80 in
adolescents. Within all grade levels, the 7-d monitoring protocol produced
acceptable estimates of daily participation in MVPA (R = 0.76 (0.71-0.81) to 0.87
(0.84-0.90)). Compared with weekdays, children exhibited significantly higher
levels of MVPA on weekends, whereas adolescents exhibited significantly lower
levels of MVPA on weekends. Principal components analysis revealed two distinct
time components for MVPA during the day for children (early morning, rest of the
day), and three distinct time components for MVPA during the day for adolescents
(morning, afternoon, early evening). CONCLUSIONS: These results indicate that a 7
d monitoring protocol provides reliable estimates of usual physical activity
behavior in children and adolescents and accounts for potentially important
differences in weekend versus weekday activity behavior as well as differences in
activity patterns within a given day.
PMID- 10694128
TI - Characteristics and etiology of exercise-related transient abdominal pain.
AB - PURPOSE AND METHODS: In order to investigate the characteristics of the exercise
related transient abdominal pain (ETAP) commonly referred to as "stitch," a
questionnaire was administered to a total of 965 regular sporting participants
involved in six sports. RESULTS: The percentage of respondents claiming to have
experienced ETAP within the past year for the respective sports were: running
(69%, N = 439), swimming (75%, N = 103), cycling (32%, N = 76), aerobics (52%, N
= 126), basketball (47%, N = 121), and horse riding (62%, N = 100). ETAP appears
to be most prevalent in activities that involve repetitive torso movement, either
vertical translation or longitudinal rotation. ETAP appears to be a single
condition, common in its manifestation to most sufferers, and was described by
respondents as a well-localized pain (79%), mostly experienced in the right or
left lumbar regions of the abdomen (78%). The sensation of ETAP may be related to
the severity of pain with less intense ETAP being described as cramping, aching,
or pulling, and greater severity ETAP as sharp or stabbing in nature. Fourteen
percent of respondents indicated that they experience shoulder tip pain (STP),
which being the diaphragmatic-referred site could suggest irritation of the
diaphragm. Respondents claiming to have experienced ETAP were more likely to
report STP (r = 0.14, P < 0.01). CONCLUSIONS: The findings of the present study
provide perspective on previously suggested etiologies of ETAP, which include
diaphragmatic ischemia and stress on the visceral "ligaments," and form the basis
for examining alternative etiologies such as cramp of the musculature and
irritation of the parietal peritoneum.
PMID- 10694129
TI - Effect of bright light on cycling performance.
AB - PURPOSE: The purpose of this study was to examine the effect of exposure to three
levels of light intensity during cycling on average power output during an all
out 20-min bout of cycle ergometry. METHODS: Twelve male competitive cyclists,
with a mean age of 24.3 +/- 3.2 yr, were tested on four separate occasions.
During each test session, participants were instructed to produce the highest
possible average power output during a 20-min bout of cycle ergometry. Session 1
served as a adaptation trial and was conducted in normal room lighting
(approximately 250 lux). In subsequent sessions each participant exercised while
sitting in front of a light box. Light intensity was experimentally manipulated
through the use of sunglasses that provided high, medium, and low light
filtration. Light condition order was counterbalanced. Measurements of heart
rate, muscle pain, local perceived exertion, metabolism, and alertness were made
during exercise. Mood was assessed before and following exercise with the POMS
BI. RESULTS: There were no statistically significant differences in the average
total power output in the 1,411 lux (274.9 +/- 21.8 W), 2,788 lux (274.4 +/- 20.5
W), and 6,434 lux (270.3 +/- 19.8 W) light conditions. The difference between the
average power output in the brightest and least bright condition (4.6 W) was
approximately one-fourth of a pooled SD (d = 0.22). There were no significant
differences among the conditions in alertness, leg muscle pain, perceived
exertion, heart rate, VO2, or mood responses to the exercise. CONCLUSION: It is
concluded that exposure to bright light resulting in estimated retinal exposures
ranging from 1,411 to 6,434 lux did not have a large or systematic influence on
the performance of 20 min of maximal cycle ergometry.
PMID- 10694130
TI - Perceived submaximal force production in young adult males and females.
AB - Clinical treatment in physical rehabilitation routinely uses perceived relative
forces. PURPOSE: This study used psychophysical methods to quantify subjects'
errors during submaximal muscular force production. METHODS: A sample of young
adult (aged 23 +/- 3 yr) females (N = 60, 62 +/- 14 kg) and males (N = 50, 72 +/-
13 kg) performed a chest press on a hydraulic dynamometer with which they were
unfamiliar. In four consecutive presses with a 2-min rest interval between each
press, the subjects were asked to produce a force in the order of 25%, 50%, 75%
of their maximal force, and a final maximal press. Pilot data (N = 10) indicated
good reliability (r(xx) > 0.80) for the protocol. RESULTS: The rs between
perceived force production and the desired production were 0.76 (P < 0.001) for
males and 0.75 (P < 0.001) for females. The exponent for the power function
between the perceived and desired forces was 1.12 for males and 1.03 for females.
The total error ranged from 2.82 kg x m (males) to 1.22 kg x m (females). The rs
and the logarithmic matching of perceived and desired force indicated a linear
relationship that is consistent with Borg's range model, which has proposed that
perceptual intensities of force for different people are approximately set equal
at a subjective maximum. CONCLUSION: Many young healthy subjects can produce
relative muscular forces with good accuracy. However, some subjects will provide
very inaccurate forces that might affect outcomes in rehabilitation or physical
training.
PMID- 10694131
TI - Children's OMNI scale of perceived exertion: mixed gender and race validation.
AB - PURPOSE: The newly developed Children's OMNI Scale of Perceived Exertion
(category range: 0 to 10) was validated using separate cohorts of female and
male, African American and white subjects. Each of the four cohorts contained 20
clinically normal, nonobese children, 8-12 yr of age. METHODS: A cross-sectional,
perceptual estimation paradigm using a single multi-stage cycle ergometer test
protocol was used. Oxygen uptake (VO2; mL x min(-1)), heart rate (HR; beats x
min(-1)) and ratings of perceived exertion for the overall body (RPE-Overall),
legs (RPE-Legs), and chest (RPE-Chest) were determined at the end of each
continuously administered 3-min power output (PO) (i.e., 25, 50, 75, and 100 W)
test stage. RESULTS: The range of responses over the four POs for all cohorts was
VO2: 290.8 to 1204.0 mL x min(-1); HR: 89.2 to 164.4 beats x min(-1); and RPE
Overall, RPE-Legs, and RPE-Chest: 0.85 to 9.1. First-order correlation and linear
regression analyses were performed for each cohort separately and the total
sample using a repeated measures paradigm over the four POs. For all
correlation/regression paradigms RPE-Overall, RPE-Legs, and RPE-Chest distributed
as a positive linear function of both VO2 and HR; r = 0.85 to 0.94; P < 0.01.
Differences between RPE-Overall, RPE-Legs, and RPE-Chest were examined with ANOVA
for the repeated measures paradigm. RPE-Legs was higher (P < 0.01) than RPE-Chest
and RPE-Overall at 25, 50, 75, and 100 W. RPE-Chest did not differ from RPE
Overall at 25 and 50 W but was lower (P < 0.01) than RPE-Overall at 75 and 100 W.
CONCLUSION: The psycho-physiological responses provide validity evidence for use
of the Children's OMNI Scale over a wide range of dynamic exercise intensities.
PMID- 10694132
TI - Quadriceps EMG/force relationship in knee extension and leg press.
AB - PURPOSE: This study compared the relationship between surface electromyographic
(EMG) activity and isometric force of m. quadriceps femoris (QF) in the single
joint knee extension (KE) and the multi-joint leg press (LP) exercises. METHODS:
Nine healthy men performed unilateral actions at a knee angle of 90 degrees at
20, 40, 60, 80, and 100% of maximal voluntary contraction (MVC). EMG was measured
from m. vastus lateralis (VL), m. vastus medialis (VM), m. rectus femoris (RF),
and m. biceps femoris (BF). RESULTS: There were no differences in maximum EMG
activity of individual muscles between KE and LP. The QF EMG/force relationship
was nonlinear in each exercise modality. VL showed no deviation from linearity in
neither exercise, whereas VM and RF did. BF activity increased linearly with
increased loads. CONCLUSIONS: The EMG/force relationship of all quadricep muscles
studied appears to be similar in isometric multi-joint LP and single-joint KE
actions at a knee angle of 90 degrees. This would indicate the strategy of
reciprocal force increment among muscles involved is comparable in the two
models. Furthermore, these data suggest a nonuniform recruitment pattern among
the three superficial QF muscles and surface EMG recordings from VL to be most
reliable in predicting force output.
PMID- 10694133
TI - Determination of the velocity associated with VO2max.
AB - PURPOSE: The theoretical velocity associated with VO2max (vVO2max) defined by
Daniels (1985) is extrapolated from the submaximal VO2-velocity relationship. VO2
is generally determined by assuming that the aerobic response reacts like a
linear first-order system at the beginning of square-wave exercise with a steady
state reached by the 4th minute. However, at supra-ventilatory threshold work
rates, the steady state in VO2 is delayed or not attained. METHODS: The present
study was carried out to compare three values for vVO2max determined with
Daniels' method, but with VO2 either measured at the 4th minute (vVO2max4), the
6th minute (vVO2max6), or after the attainment of the true steady-state
(vVO2maxSS). The metabolic response during square-wave exercise at each of the
three vVO2max were also assessed. RESULTS: These velocities were significantly
different (P < 0.05), but vVOmaxSS and vVO2max6 were highly correlated (r = 0.98;
P < 0.05). Blood lactate concentrations measured after exercise at velocities
very close to the three vVO2max were similar and the end-exercise VO2 were not
different from VO2max, but the time required to elicit 95% VO2max during these
three square-wave tests were significantly different. CONCLUSION: Therefore, when
vVO2max is determined by extrapolation from the submaximal VO2-velocity
relationships, submaximal VO2 should be measured beyond the 6th minute of square
wave exercise (at least if it takes 30 s to reach the desired velocity) to ensure
that all vVO2max reported in future studies describe a similar quantitative
index.
PMID- 10694134
TI - Influence of midsole bending stiffness on joint energy and jump height
performance.
AB - PURPOSE: A substantial amount of rotational energy is lost at the
metatarsophalangeal joint during running and jumping. We hypothesized that the
lost energy could be decreased by increasing the bending stiffness of shoe
midsoles. The purposes of this investigation were to determine the influence of
stiff shoe midsoles on changes in lower extremity joint power during running and
jumping and to determine the influence of stiff shoe midsoles on vertical jump
performance. METHODS: Carbon fiber plates were inserted into shoe midsoles and
data were collected on five subjects during running and vertical jumping.
RESULTS: The data showed that energy generation and absorption at each of the
ankle, knee, and hip joints was not influenced by the stiffness of the shoe
midsole. The stiff shoes with the carbon fiber plates did not increase the amount
of energy stored and reused at the metatarsophalangeal joint; however, they
reduced the amount of energy lost at this joint during both running and jumping.
Vertical jump height was significantly higher (average, 1.7 cm for a group of 25
subjects) while wearing the stiff shoes. CONCLUSIONS: Increasing the bending
stiffness of the metatarsophalangeal joint reduced the amount of energy lost at
that joint and resulted in a corresponding improvement of performance.
PMID- 10694135
TI - Control of maximal and submaximal vertical jumps.
AB - PURPOSE: It was investigated to what extent control signals used by human
subjects to perform submaximal vertical jumps are related to control signals used
to perform maximal vertical jumps. METHODS: Eight subjects performed both maximal
and submaximal height jumps from a static squatting position. Kinematic and
kinetic data were recorded as well as electromyographic (EMG) signals from eight
leg muscles. Principal component analysis was used analyze the shape of smoothed
rectified EMG (SREMG) histories. Jumps were also simulated with a forward dynamic
model of the musculoskeletal system, comprising four segments and six muscles.
First, a maximal height jump was simulated by finding the optimal stimulation
pattern, i.e., the pattern resulting in a maximum height of the mass center of
the body. Subsequently, submaximal jumps were simulated by adapting the optimal
stimulation pattern using strategies derived from the experimental SREMG
histories. RESULTS: SREMG histories of maximal and submaximal jumps revealed only
minor differences in relative timing of the muscles between maximal and
submaximal jumps, but SREMG amplitude was reduced in the biarticular muscles. The
shape of the SREMG recordings was not much different between the two conditions,
even for the biarticular muscles. The simulated submaximal jump resembled to some
extent the submaximal jumps found in the experiment, suggesting that differences
in control signals as inferred from the experimental data could indeed be
sufficient to get the observed behavior. CONCLUSIONS: The results fit in with
theories on the existence of generalized motor programs within the central
nervous system, the output of which is determined by the setting of parameters
such as amplitude and relative timing of control signals.
PMID- 10694136
TI - Influence of the menstrual cycle phase and menstrual symptoms on maximal
anaerobic performance.
AB - PURPOSE: This study was designed to analyze the effect of the menstrual cycle
phase on maximal anaerobic performance during short-term anaerobic tests.
METHODS: Seven eumenorrheic women (NOC) and 10 women using monophasic oral
contraceptives (OC) performed three anaerobic tests (force-velocity, multi-jump,
and squatting jump tests) during menstruation (M: between days 1 and 4), the
midfollicular phase (F: between days 7 and 9), and the midluteal phase (L:
between days 19 and 21) of the ovarian cycle. Follicular and luteal phases were
confirmed by serum progesterone levels. The order of testing sessions was
randomly assigned and a 15-min standardized warm-up preceded each testing
session. Rectal temperatures were taken before (Trec(b)) and after (Trec(a)) warm
up. RESULTS: No significant differences were observed among M, F, and L in
Trec(b), Trec(a) maximal cycling power (Pmax(c)), maximal jumping power
(Pmax(j)), or maximal height of jump (h(j)) in either NOC or OC. Ten of the women
suffered premenstrual or menstrual symptoms (MS); the other seven did not report
any premenstrual or menstrual discomfort (NMS). Presence or absence of symptoms
was not correlated with oral contraceptive use. No significant differences were
observed among the three stages of the menstrual cycle in Pmax(c), Pmax(j), or
h(j) in NMS. In MS, only Pmax(j) decreased by 8% in M compared with that in F (P
< 0.05). CONCLUSIONS: Although there were no significant differences in maximal
anaerobic performance during different menstrual cycle phases, results of this
study suggest that the presence or absence of premenstrual or menstrual syndrome
symptoms may have an effect, possibly through an action on the stretch-shortening
cycle of tendons and ligaments.
PMID- 10694137
TI - Testing peak cycling performance: effects of braking force during growth.
AB - The purpose of this study was to investigate the relationship between cycling
peak power (CPP; flywheel inertia included) and the applied braking force (F(B))
on a friction-loaded cycle ergometer in male children, adolescents, and adults. A
total of 520 male subjects aged 8-20 yr performed three brief maximal sprints
against three F(B): 0.245, 0.491, and 0.736 N x kg(-1) body mass (BM)
(corresponding applied loads: 25 [F(B)25], 50 [F(B)50], and 75 [F(B)75] g x kg(
1) BM). For each F(B), peak power (PP) was measured (PP25, PP50 and PP75). For
each subject, the highest PP was defined as CPP. Results showed that PP was
dependent on F(B). In young adults PP25 underestimated CPP by more than 10%, and
consequently, F(B)25 seemed to be too low for this population. However, in
children, PP75 underestimated CPP by about 20%. A F(B) of 0.736 N x kg(-1) BM was
definitively too high for the pediatric population. Therefore, the optimal F(B),
even corrected for BM, was lower in children than in adults. The influence of
growth and maturation on the force-generating capacity of the leg muscles may
explain this difference. In this study, however, it was shown that the difference
between PP50 and CPP was independent of age for the whole population
investigated. Consequently, when flywheel inertia is included, one cycling sprint
with a F(B) of 0.495 N x kg(-1) BM (corresponding applied load: 50 g x kg(-1) BM)
is a feasible method for testing both children, adolescents, or young adults.
PMID- 10694138
TI - The effect of caffeine on endurance performance after nonselective beta
adrenergic blockade.
AB - PURPOSE: This study was designed to test the hypothesis that combined
administration of propranolol and caffeine (Pr+C) would increase endurance
performance compared with the administration of propranolol alone (Pr) if
caffeine would be able to increase plasma free fatty acid (FFA) availability
and/or lower plasma potassium concentration compared with propranolol
administration alone. METHODS: Fifteen volunteers participated in the double
blind placebo-controlled randomized cross-over study. An endurance exercise test
until exhaustion was performed after ingestion of placebo (Pl), 80-mg propranolol
(Pr), and 80-mg propranolol plus 5 mg x kg(-1) caffeine (Pr+C). RESULTS:
Endurance time (+/-SD) was 79.3 +/- 20.4 min in the Pl trial, 22.6 +/- 10.8 min
in the Pr trial and 31.2 +/- 17.2 min in the Pr+C trial (P < 0.001). The
difference between the Pr and Pr+C trials just failed to reach statistical
significance (P = 0.056). Plasma FFA concentration and plasma potassium
concentrations were similar in the Pr and Pr+C trials, but differed significantly
from the Pl trial (P < 0.05). CONCLUSION: Although there was a clear tendency for
an improved performance in the Pr+C trial compared to the Pr trial, this
improvement was not associated with increased plasma FFA concentration and/or
reduced plasma potassium concentration in the Pr+C compared to the Pr trial.
These results do not support the hypothesis that caffeine improves endurance
performance by stimulating lipolysis or lowering plasma potassium concentration.
PMID- 10694139
TI - Effect of commuter cycling on physical performance of male and female employees.
AB - PURPOSE: The purpose of this study was to determine the effect of commuter
cycling on physical performance. Eighty-seven male and 35 female employees
volunteered to cycle regularly to their work. METHODS: Sixty-one participants
went commuter cycling for 1 yr (cycling group); the others cycled only in the
second half year (control group). A maximal exercise test on a cycle ergometer
was carried out at the start of the study, after 6 months, and after 1 yr to
measure maximal external power (Wmax) and maximal oxygen uptake (VO2max).
RESULTS: After the first 6 months of commuter cycling, with a mean single trip
distance of 8.5 km and a mean frequency of more than three times a week, a
significant increase of 13% was found in the Wmax per kilogram body weight (Wmax
x kg(-1)) in both sexes of the cycling group. The improvement in VO2max x kg(-1)
was significant for the male participants (6%) but not for the female
participants (-2%). At the end of the second half year, the control group also
showed a mean gain in Wmax x kg(-1) of 13%. Their VO2max x kg(-1) declined in the
first half year, but this was counteracted in the second half year. A dose
response relationship was found between two independent variables and the
physical performance; the lower the physical performance at the start of the
study and the higher the total amount of kilometers cycled, the higher the gain
in Wmax. For subjects with a low initial fitness level, a single trip distance of
only 3 km turned out to be enough to improve physical performance. CONCLUSION:
Commuter cycling can yield much the same improvement in physical performance as
specific training programs.
PMID- 10694140
TI - Physiological responses to a 6-d taper in middle-distance runners: influence of
training intensity and volume.
AB - PURPOSE: This study examined some physiological and performance responses to a 6
d taper, and the influence of training intensity and volume on these responses.
METHODS: After 15 wk of training, 8 well-trained male middle-distance runners
were randomly assigned to either a moderate volume taper (MVT, N = 4) or a low
volume taper (LVT, N = 4), consisting of either a 50% or a 75% progressive
reduction in pretaper low intensity continuous training (LICT) and high intensity
interval training (HIIT). Blood samples were obtained and 800-m running
performance was measured before and after taper. RESULTS: Performance was not
significantly enhanced by either taper protocol (post- vs pre-taper times 124.9
+/- 4.5 vs 126.1 +/- 4.2 s with LVT, 126.2 +/- 8.0 vs 125.7 +/- 6.6 s with MVT).
For the entire group of 8 subjects, red cell count, hemoglobin (Hb), mean
corpuscular volume and mean corpuscular Hb concentration significantly decreased
with taper, while reticulocyte count increased. Performance changes for all
subjects correlated with changes in postrace peak blood lactate concentration (r
= 0.87, P < 0.01). Taper LICT correlated with changes in Hb (r = 0.77),
hematocrit (r = 0.81), reticulocyte count (r = 0.73), creatine kinase (r = 0.72),
and total testosterone (r = -0.78), and with posttaper red cell distribution
width (r = -0.75) and lymphocyte count (r = -0.82). Taper HIIT correlated
nonsignificantly with changes in red cell count (r = -0.66) and total
testosterone (r = 0.68). CONCLUSION: It is concluded that taper-induced
physiological changes in trained middle-distance runners are mainly
hematological, and that distinct physiological changes are elicited from LICT and
HIIT during taper. Middle-distance runners can progressively reduce their usual
training volume by at least 75% during a 6-d taper.
PMID- 10694141
TI - Creatine supplementation and sprint performance in soccer players.
AB - PURPOSE: This investigation examined the effects of creatine (Cr) supplementation
on intermittent high-intensity exercise activities specific to competitive
soccer. METHODS: On two occasions 7 d apart, 17 highly trained male soccer
players performed a counter-movement jump test (CMJT), a repeated sprint test
(RST) consisting of six maximal 15-m runs with a 30-s recovery, an intermittent
endurance test (IET) consisting of forty 15-s bouts of high-intensity running
interspersed by 10-s bouts of low-intensity running, and a recovery CMJT
consisting of three jumps. After the initial testing session, players were evenly
and randomly included in a CREATINE (5 g of Cr, four times per day for 6 d) or a
PLACEBO group (same dosage of maltodextrins) using a double-blind research
design. RESULTS: The CREATINE group's average 5-m and 15-m times during the RST
were consistently faster after the intervention (0.95 +/- 0.03 vs 0.97 +/- 0.02
s, P < 0.05 and 2.29 +/- 0.08 vs 2.32 +/- 0.07 s, P = 0.07, respectively).
Neither group showed significant changes in the CMJT or the IET. The CREATINE
group's recovery CMJT performance relative to the resting CMJT remained unchanged
postsupplementation, whereas it tended to decrease in the PLACEBO group.
CONCLUSION: In conclusion, acute Cr supplementation favorably affected repeated
sprint performance and limited the decay in jumping ability after the IET in
highly trained soccer players. Intermittent endurance performance was not
affected by Cr.
PMID- 10694142
TI - Effect of mathematical modeling on the estimation of critical power.
AB - PURPOSE: The purposes of this study were to re-examine the findings of previous
studies by comparing the critical power (CP) estimates from five mathematical
models and to determine the time to exhaustion during cycle ergometry at the
lowest CP estimate from the five models. METHODS: Nine adult males performed a
maximal incremental test to determine peak power and five or six randomly ordered
trials on a cycle ergometer for the estimation of CP. Two linear, two nonlinear,
and one exponential mathematical model were used to estimate CP. The subjects
then completed two trials to exhaustion, or 60 min, at their lowest estimate of
CP from the five models. RESULTS: The nonlinear three-parameter model (Nonlinear
3) produced a mean CP that was significantly (P < 0.05) less than the mean CP
values derived from the other four models and was the lowest CP estimate for each
subject. Two and three subjects, however, did not complete 60 min of cycling
during the first and second trials at CP, respectively. At the end of the trials
the subjects who completed 60 min of cycling had a mean heart rate of 92% of
their maximum and a mean rating of perceived exertion of 17. CONCLUSION: These
findings support previous studies that have indicated that in many cases CP
overestimates the power output that can be maintained for at least 60 min.
PMID- 10694143
TI - Validation of near-infrared interactance and skinfold methods for estimating body
composition of American Indian women.
AB - PURPOSE: This study tested the predictive accuracy of the Jackson et al. skinfold
(SKF) equations (sigma7SKF and sigma3SKF), a multi-site near-infrared
interactance (NIR) prediction equation, and the Futrex-5000 NMR equation in
estimating body composition of American Indian women (N = 151, aged 18-60 yr).
METHODS: Criterion body density (Db) was obtained from hydrodensitometry at
residual lung volume. RESULTS: Sigma7SKF significantly underestimated Db (P <
0.05). Sigma3SKF and Heyward's NIR equations significantly overestimated Db (P <
0.05). The Futrex-5000 NIR equation significantly underestimated percent of body
fat (%BF) (P < 0.05). Prediction errors for SKF and multi-site NIR exceeded
0.0080 g x cc(-1). The SEE for Futrex-5000 was 5.5%BF. Thus, ethnic-specific SKF
and NIR equations were developed. For the SKF model, the sigma3SKF (triceps,
axilla, and suprailium) and age explained 67.3% of the variance in Db:Db =
1.06198316 -0.00038496(sigma3SKF) -0.00020362(age). Cross-validation analysis
yielded r = 0.88, SEE = 0.0068 g x cc(-1), E = 0.0070 g x cc(-1), and no
significant difference between predicted and criterion Db. For the NIR model, the
hip circumference, sigma2AdeltaOD2 (biceps and chest), FIT index, age, and height
explained 73.9% of the variance in Db:Db = 1.0707606 -0.0009865(hip
circumference) -0.0369861(sigma2deltaOD2) + 0.0004167(height) + 0.0000866(FIT
index) -0.0001894(age). Cross-validation yielded r = 0.85, SEE = 0.0076 g x cc(
1), E = 0.0079 g x cc(-1), and a small, but significant, difference between
predicted and criterion Db. CONCLUSIONS: We recommend using the ethnic-specific
SKF and NIR equations developed in this study to estimate Db of American Indian
women.
PMID- 10694144
TI - Skinfold thickness varies directly with spring coefficient and inversely with jaw
pressure.
AB - PURPOSE: The main aims of this study were to: 1) determine whether heavy use of
Harpenden calipers caused deterioration of the spring coefficient (force per unit
length), 2) to quantify the change in skinfold thickness per unit change in jaw
closing (downscale) pressure, and 3) to develop a calibration range for these
calipers. METHODS: Part a) The change in spring force per unit length after at
least 100,000 cycles of opening and closing five different springs was measured
on a load cell. Part b) The dynamic downscale jaw pressure exerted by six pairs
of Harpenden springs was measured on one caliper. Two were new pairs of springs
(N1 and N2), two were 25-yr-old springs (O1 and O2), and two pairs (S1 and S2)
had been used for less 1 yr. The six spring pairs were used to measure skinfold
thicknesses at nine sites, in triplicate, on 20 subjects with the order of
springs randomized and counterbalanced. Part c) The downscale jaw pressure of 78
Harpenden calipers was measured at eight jaw gaps. RESULTS: Part a) The springs
did not change their characteristics after >100,000 cycles. Part b) At each
skinfold site, the lowest thickness was recorded for S2 which exerted the highest
jaw pressure (9.04 g x mm(-2)) and conversely the highest thickness was for N1
which exerted the lowest jaw pressure (8.02 g x mm(-2)). Increasing the downscale
jaw closing pressure from 8.0 to 9.0 g x mm(-2) reduced a skinfold thickness by
approximately 10%. Part c) The mean downscale jaw pressure was 7.82 +/- 0.25 g x
mm(-2). CONCLUSIONS: In summary, it is suggested that if accurate skinfold
measures between different Harpenden calipers are required, the downscale jaw
pressure should be in the range of 7.40-7.82 and 7.85-8.21 g x mm(-2), at jaw
gaps of 5 and 40 mm, respectively. These jaw pressures can be achieved by
servicing the caliper pivot and indicator gauge to minimize frictional losses,
adjusting the caliper jaw alignment, and by selecting springs that have a spring
coefficient in the range 1.10-1.15 N x mm(-1).
PMID- 10694145
TI - Carriage of a new epidemic strain of Neisseria meningitidis and its relationship
with the incidence of meningococcal disease in Galicia, Spain.
AB - In Galicia, Spain, a dramatic increase in the incidence of meningococcal disease
was seen in the 1995-6. The annual incidence rose to 11 per 10(5) inhabitants,
and 80% of identified strains were C:2b:P1.2,5. This led to the implementation of
an intensive A+C vaccination campaign for the population aged 18 months to 19
years. During this campaign the prevalence of carriage in areas with high and low
incidence was studied. Nasopharyngeal swabs were taken from 9796 subjects
immediately before the administration of meningococcal vaccine, plated onto
Thayer-Martin plates, incubated and sent for analysis to the Reference Laboratory
for Neisseria in Spain. The prevalence of the C:2b: P1.2,5 strains was 0.6% (95%
CI 0.29-0.88) in the high incidence area, and 0.41% (95 % CI 0.00-1.04) in the
low incidence area, and that of serogroup C (all strains) 1.36% (95% CI 0.80
1.80) and 0.89% (95% CI 0.09-1.69) respectively. The prevalence of N.
meningitidis (all strains) was almost the same in both areas (8%). Carriers of
the epidemic strain were not found in the 2-4 year age group, that most affected
by the disease. Our data showed a wide distribution but a low carriage rate of
the epidemic strain C:2b:P1.2,5 in the high and low disease incidence areas
studied; the difference in the carriage rates between the two areas was not
statistically significant.
PMID- 10694146
TI - Predicting the course of meningococcal disease outbreaks in closed
subpopulations.
AB - A stochastic epidemic model was applied to meningococcal disease outbreaks in
defined small populations such as military garrisons and schools. Meningococci
are spread primarily by asymptomatic carriers and only a small proportion of
those infected develop invasive disease. Bayesian predictions of numbers of
invasive cases were developed, based on observed data using a stochastic epidemic
model. We used additional data sets to model both disease probability and
duration of carriage. Markov chain Monte Carlo sampling techniques were used to
compute the full posterior distribution which summarized all information drawn
together from multiple sources.
PMID- 10694147
TI - Outbreak of meningococcal disease in western Norway due to a new serogroup C
variant of the ET-5 clone: effect of vaccination and selective carriage
eradication.
AB - A new sulphonamide resistant (SR) C: 15:P1.7,16 meningococcal strain, a variant
of the ET-5 clone, dominated in an outbreak of 22 cases in western Norway
commencing in 1995. The first eight patients were 15-21 years old from the
Nordhordland area, initiating a carrier study in the local high schools. Carriage
of SR serogroup C meningococci was detected by routine methods and treated with a
single dose of ofloxacin 400 mg. Of 20 treated carriers, 14 harboured the
outbreak strain C: 15:P1.7,16. Vaccination of 4000 children, adolescents and
close contacts of patients was also performed. After the intervention, 14
additional cases of meningococcal disease occurred, 8 due to the outbreak strain.
However, incidence rates dropped from 180 to 30 per 100000 per year in the
student population, but increased from 0 to 13 in the rest of the population in
Nordhordland. Carriage eradication is not generally recommended in Norway.
However, tracing and treating meningococcal carriage may have reduced
transmission and disease in this outbreak situation.
PMID- 10694148
TI - Nasopharyngeal colonization of infants in southern India with Streptococcus
pneumoniae.
AB - To investigate the dynamics of nasopharyngeal colonization with Streptococcus
pneumoniae, and to determine the prevalent serogroups/types (SGT) and their
antimicrobial susceptibility, we studied 100 infants attending our well-baby
clinic. Nasopharyngeal swab specimens were obtained at 6, 10, 14, 18 and 22 weeks
and at 9 and 18 months of age and submitted for culture, serotyping and
antimicrobial susceptibility testing of S. pneumoniae. Colonization with
pneumococcus was seen on at least one occasion in 81 infants. The median age of
acquisition was 11 weeks and the median duration of carriage was 1 3 months. The
common SGTs identified were 6, 19, 14 and 15. SGT 1, which was a common invasive
isolate in children in our hospital during this period, was not isolated from
these children. Sequential colonization by 2, 3 or 4 SGTs was observed in 18, 5
and 2 children, respectively. Resistance to penicillin, chloramphenicol,
cotrimoxazole and erythromycin was observed in 0, 13 (6%) 11 (5 %) and 5 (3 %)
isolates, respectively. There was a significant difference in susceptibility to
cotrimoxazole between colonizing and invasive isolates (5 % vs. 40 %, P<0.0001).
PMID- 10694149
TI - The Hib immunization programme in the Oxford region: an analysis of the impact of
vaccine administration on the incidence of disease.
AB - In May 1991 an immunization programme against Haemophilus influenzae type b (Hib)
infection began within the Oxford region. We validate a deterministic
mathematical model of Hib by comparison with the incidence of disease in the
Oxford region, 1985-97. The comparison of model results with observed outcome
allows an exploration of some of the poorly understood properties of the
immunization programme. Model results and observed incidence are consistent with
a vaccine that blocks the acquisition of carriage. Similarly, the data suggest
that factors other than experience of Hib carriage are likely to have generated
acquired immunity to Hib disease prior to the introduction of vaccination. Hence
it is unlikely that waning of vaccine-derived protection will result in a
resurgence of disease. The inclusion in the immunization schedule of a booster
dose, as used in other countries, would have provided very little extra benefit.
PMID- 10694150
TI - Bordetella pertussis surveillance in England and Wales: 1995-7.
AB - Available data sources on disease due to Bordetella pertussis, including
notifications, hospital admissions, deaths, and an enhanced laboratory-based
surveillance system commenced in January 1994, were reviewed for the period 1995
7. Pertussis notifications continued their approximately 3-year cycle although at
historically reduced levels. A slight seasonal increase in late summer/early
autumn existed over and above a relatively constant background rate. Over time,
the proportion of pertussis cases in younger, unvaccinated children, and to a
lesser extent, adolescents and young adults, is increasing. There is a continuing
significant and underreported mortality associated with pertussis in the very
young age group. Disease due to serotype 1,2 is on the increase despite
persistent high vaccination levels and this serotype causes more severe disease.
The provision of preventative antibiotics prior to disease onset reduced the
severity of the disease but its use remains uncommon in England and Wales. While
overall levels of pertussis notifications have declined in recent times,
vaccination efficacy wanes with increasing age, and pertussis remains a
significant cause of mortality and severe morbidity in the very young. This could
be reduced by timely booster vaccination and increased recognition of mild
disease in older cases followed by early antibiotic therapy for the very young
household contacts.
PMID- 10694151
TI - Characterization of enteroaggregative Escherichia coli isolated from outbreaks of
diarrhoeal disease in England.
AB - Twenty-two strains of enteroaggregative Escherichia coli (EAggEC), isolated from
four outbreaks of diarrhoeal disease in England, were examined for a range of
phenotypic attributes including the ability to produce fimbriae, haemolysins and
siderophores, and cell-surface properties such as surface charge and
hydrophobicity. Strains of EAggEC isolated from two of these outbreaks belonged
to a diverse range of serotypes and were heterogeneous in phenotype. Strains of
EAggEC isolated from the other two outbreaks belonged predominantly to serotypes
086:H34 and 098:H-, respectively. Only two strains expressed fimbriae and two
strains produced an 18 kDa membrane associated protein (MAP), suggesting that
EAggEC express a range of adhesion mechanisms to produce the cell arrangement
recognized as the 'stacked brick' formation. The possible explanation for the
diversity of EAggEC serotypes is discussed.
PMID- 10694152
TI - Levels of virulence are not determined by genomic lineage of Salmonella enterica
serotype Enteritidis strains.
AB - Mouse virulence and the ability to adhere to, and invade cultured MDCK cells were
investigated in 38 phage type reference strains of Salmonella enterica serotype
Enteritidis and correlated with genomic lineage. The genomic lineage of 11 of the
strains was determined in the present study; one IS200 and one ribotype pattern
that had not been reported previously were observed. Log c.f.u. in the spleen 10
days post intraperitoneal (i.p.) infection with 3x10(3) bacteria (logVC10) varied
between 2.9 and 8.7. The reference strains of PT7 and PT23 were found to be semi
rough and were of low virulence. All other strains possessed smooth LPS. Within
each of the two major clonal lines, as well as among phage types outside these,
both highly virulent and moderate to low virulent strains were present. While all
strains of PT1, PT2 and PT8 were highly virulent, low virulent strains were
detected in PT4 and PT13. The ability to adhere to, and invade MDCK cells varied
between phage types (adherence between 13 and 61% of the inocula and invasion
between 4 and 151% of the adherent cells). The results of the cell culture
experiments did not correlate with the results of mouse virulence tests. No
correlation between clonal lineage and virulence was found within S. Enteritidis.
It seems most likely that some strains have lost some of the essential factors
enabling this serotype to cause successful systemic infection.
PMID- 10694153
TI - Electronic network for monitoring travellers' diarrhoea and detection of an
outbreak caused by Salmonella enteritidis among overseas travellers.
AB - The Traveller's Diarrhoea Network, by which the Infectious Disease Surveillance
Center is electronically connected with two major airport quarantine stations and
three infectious disease hospitals, was launched in February 1988 in Japan. The
data on travellers' diarrhoea detected is reported weekly by e-mail. Two clusters
of infection among travellers returning from Italy were reported by two airport
quarantine stations at the end of September 1998. A total of 12 salmonella
isolates from 2 clusters were examined. All were identified as Salmonella
enteritidis, phage type 4 and showed identical banding patterns on pulsed-field
gel electrophoresis. A case-control study showed that the scrambled eggs served
at the hotel restaurant in Rome were the likely source of this outbreak. This
outbreak could not have been detected promptly and investigated easily without
the e-mail network. International exchange of data on travellers' diarrhoea is
important for preventing and controlling food-borne illnesses infected abroad.
PMID- 10694154
TI - Acute melioidosis outbreak in Western Australia.
AB - A cluster of acute melioidosis cases occurred in a remote, coastal community in
tropical Western Australia. Molecular typing of Burkholderia pseudomallei
isolates from culture-confirmed cases and suspected environmental sources by
pulsed-field gel electrophoresis (PFGE) of XbaI chromosomal DNA digests showed
that a single PFGE type was responsible for five cases of acute infection in a
community of around 300 during a 5 week period. This temporal and geographical
clustering of acute melioidosis cases provided a unique opportunity to
investigate the environmental factors contributing to this disease. B.
pseudomallei isolated from a domestic tap at the home of an asymptomatic
seroconverter was indistinguishable by PFGE. Possible contributing environmental
factors included an unusually acid communal water supply, unrecordable chlorine
levels during the probable exposure period, a nearby earth tremor, and gusting
winds during the installation of new water and electricity supplies. The possible
role of the potable water supply as a source of B. pseudomallei was investigated
further.
PMID- 10694155
TI - Risk of transmission of tuberculosis among inmates of an Australian prison.
AB - In a prison in Victoria, Australia, our objectives were contact tracing of
inmates and staff at risk of exposure to an identified index case; and to
determine risk factors for prevalent and incident infection. Inmates and staff
who were potentially exposed to the index case were screened with a Mantoux skin
test and a questionnaire. Inmate movements within the prison were compared to
movements of the index case. Logistic regression was used to determine risk
factors for infection. The index case had smear positive, cavitating pulmonary
tuberculosis (TB), which was undiagnosed for 3 months. This was the period of
potential exposure. The prevalence of positive skin test reactions in 190 inmates
and staff at the prison was 10%. Significant predictors of a positive skin test
were being an inmate (odds ratio (OR) 15.5), older age (OR 8.3) and being born
overseas (OR 10.7). Bacille Calmette Guerin (BCG) vaccination, proximity to the
index case in various prison sites, duration of incarceration, number of
incarcerations and number of inmates per cell were not significant. There were
three recent skin test conversions from negative to positive, representing a
conversion rate of 3.5%. We did not find evidence of significant transmission of
TB from a single index case. The prevalence of infection in this Australian
prison was lower than published rates in other countries. Better prison
conditions and different demographics of prison inmates in Australia may explain
these differences.
PMID- 10694156
TI - The effect of timing of sample collection on the detection of measles-specific
IgM in serum and oral fluid samples after primary measles vaccination.
AB - This study compares the timing of the rise and decline of measles-specific IgM in
serum samples and in oral fluid samples. Two hundred and eighty 9-month-old
infants presenting for routine measles vaccination in Addis Ababa, Ethiopia, were
enrolled. Paired serum and oral fluid samples were collected before and 1, 2, 3
or 4 weeks after measles vaccination. Samples were tested by using a modified
antibody-capture enzyme immunoassay. For the 321 IgM-negative pre- and post
vaccination serum samples, 317 (99 %) of their corresponding oral fluid samples
were IgM-negative. Among the 130 IgM-positive serum samples, 75% of their paired
oral fluid samples were IgM-positive, with the percentage rising to 87% after
oral fluid samples collected > or =3.5 weeks after vaccination were excluded.
Among the post-vaccination serum samples, the percent IgM-positive peaked in week
3 and declined to 79% in week 4. For post-vaccination oral fluid samples, the
percent IgM-positive peaked in weeks 2 and 3, and then declined to 43% in week 4.
This modified antibody-capture enzyme immunoassay appears to detect vaccine
induced measles-specific IgM in the first 3 weeks after vaccination.
PMID- 10694157
TI - Intestinal protozoa in HIV-infected patients in Apulia, South Italy.
AB - Protozoa are important enteric pathogens in patients with human immunodeficiency
virus (HIV) infection. In this study the prevalence of intestinal protozoa in 154
HIV-infected patients, with or without diarrhoea, in our region (Apulia, South
Italy) was evaluated between December 1993 and February 1998. In the majority of
patients CD4+ T cell count was below 200/microl. The overall prevalence of
intestinal protozoa was 43/154 (27.92%). Twenty-eight (43.08%) out of 65 patients
with diarrhoea and 15 (16-85%) out of 89 non-diarrhoeic patients were
parasitized. In particular, in the group of 65 patients with diarrhoea the
following protozoa were identified: Cryptosporidium parvum in 14 (21.54%),
Blastocystis hominis in 7 (10.77%), microsporidia in 6 (9.23%), Giardia lamblia
in 4 (6.15%) and Isospora belli in 1 (1.54%). Three patients were Cryptosporidium
parvum-microsporidia co-infected. In patients without intestinal symptoms,
prevalence was 3/89 (3.37%) for Cryptosporidium parvum, 9/89 (10.11%) for
Blastocystis hominis, 1/89 (1.12%) for microsporidia and 2/89 (2.25%) for Giardia
lamblia. A significant (P<0.001) correlation was observed between protozoan
infection and the presence of diarrhoea. In particular, Cryptosporidium parvum
and microsporidia infections were significantly (P<0.001) and P = 0.046,
respectively) associated with diarrhoeal illness. Moreover, the majority of cases
of cryptosporidiosis were first diagnosed in the periods of heaviest rainfall.
Therefore, drinking water contamination may be a possible source of human
infection in our area.
PMID- 10694158
TI - Prevalence of hepatitis B, D and C virus infections among children and pregnant
women in Moldova: additional evidence supporting the need for routine hepatitis B
vaccination of infants.
AB - Rates of acute hepatitis B are high in Moldova, but the prevalence of chronic
infection is unknown. In 1994, we surveyed children and pregnant women, collected
demographic information, and drew blood for laboratory testing. Among the 439
children (mean age, 5 years), the prevalence of antibody to hepatitis B core
antigen (anti-HBc) and hepatitis B surface antigen (HBsAg) were 17.1 and 6.8%,
respectively. Among the 1098 pregnant women (mean age, 26 years), 52.4% were anti
HBc-positive and 9.7% were HBsAg-positive. Of the HBsAg-positive pregnant women,
35.6% were hepatitis B e antigen (HBeAg) positive and 18.3% had antibodies to
hepatitis D virus. The prevalence of antibody to hepatitis C virus was 1.4% in
children and 2.3% in pregnant women. The high HBeAg prevalence among HBsAg
positive pregnant women and the high anti-HBc prevalence among children indicate
that both perinatal and early childhood transmission contribute to the high
hepatitis B virus endemicity in Moldova.
PMID- 10694159
TI - An outbreak of calicivirus associated with consumption of frozen raspberries.
AB - In April 1988, an outbreak of gastroenteritis occurred among employees in a large
company in Helsinki, Finland. A retrospective cohort study, using a self
administered questionnaire, was carried out to ascertain the cause and extent of
the outbreak. To meet the case definition, employees had to have had diarrhoea
and/or vomiting since 2 April, 1998. A subanalysis was made in the biggest
office, consisting of 360 employees, of whom 204 (57%) completed the
questionnaire. Of these 108 (53%) met the case definition. Employees who had
eaten raspberry dressing were more likely to meet the case definition than those
who had not (Attack Rate (AR) 65% versus AR 18% Relative Risk, (RR) 3.7, 95%,
Confidence Intervals (CI) 2.0-6.7). Four stool specimens obtained from affected
kitchen staff who had all eaten the raspberry dressing and who had all become ill
simultaneously with the employees were positive by polymerase chain reaction
(PCR) for calicivirus. The data suggest that the primary source of the outbreak
was imported frozen raspberries contaminated by calicivirus.
PMID- 10694160
TI - Transmission of calicivirus by a foodhandler in the pre-symptomatic phase of
illness.
AB - After a Christmas party in a restaurant, 48 (68%) of the 82 guests contracted
calicivirus gastroenteritis. The epidemiological investigation showed that salad
was strongly associated with the disease episode (RR = 2.43, P = 0.0005). Similar
symptoms occurred among other customers who had had a meal at the same restaurant
on the same evening. A foodhandler who had only prepared salad and appetizers
became sick about 30 min after the end of his shift. He had been free of symptoms
while preparing food. Few outbreak investigations have shown calicivirus
transmission by foodhandlers some hours before becoming symptomatic.
PMID- 10694161
TI - The duration of human ocular Chlamydia trachomatis infection is age dependent.
AB - We studied the relationship between age and prevalence, duration and incidence of
clinical and laboratory evidence of ocular Chlamydia trachomatis infection in a
cohort of Gambian subjects examined bi-weekly for 6 months. The duration of
disease and infection, estimated by stratified survival analysis, proportional
hazards regression and Weibull modelling, was markedly age-dependent. The
estimated median duration of disease was 13.2 weeks in 0-4-year-old subjects and
1.7 weeks in those age 15 and over. Adjustment for multiple infections, and for
missing observations did not alter this trend. The cumulative incidence rate of
disease was reduced threefold with age. More rapid disease resolution is the main
source of reduction in prevalence of active trachoma and ocular C. trachomatis
infection with age; disease incidence was reduced to a lesser extent. This age
dependent resolution may be effected by adaptive cellular immune mechanisms.
Mechanisms responsible for natural immunity should receive appropriate emphasis
in vaccine design.
PMID- 10694162
TI - Planning chemotherapy based schistosomiasis control: validation of a mathematical
model using data on Schistosoma haematobium from Pemba, Tanzania.
AB - A mathematical model, based on a deterministic differential equation framework,
has been developed to predict the impact of community chemotherapy programmes for
human schistosomiasis. Here, this model is validated using data collected from a
long-term control programme for urinary schistosomiasis on the island of Pemba,
Zanzibar, United Republic of Tanzania, initiated in 1986 and still ongoing, in
which schoolchildren were offered praziquantel chemotherapy every 6 months.
Prevalence of infection and blood in urine were monitored in all the schools
(total 26000 children from 60 schools) and more detailed data were collected in
selected evaluation schools. Model predictions were run by using the initial
prevalence as input. The predictions were very close to the observed decreases in
prevalence and in prevalence of blood in urine. The correspondence improved
further when the data were combined, going from single school level to district,
and when the entire data set was combined. The accuracy of the predictions
suggests that this model could be used as a tool to predict the consequences of
chemotherapy control programmes. It is currently in press as a Windows software
package under the name of 'EpiSchisto'.
PMID- 10694163
TI - The potential of latent class analysis in diagnostic test validation for canine
Leishmania infantum infection.
AB - Accuracy assessment of diagnostic tests may be seriously biased if an imperfect
reference test is used such as parasitology in the diagnosis of visceral
leishmaniasis. We compared classical validity analysis of serological tests for
Leishmania infantum with Latent Class Analysis (LCA), to assess whether it
circumvented the gold standard problem. Clinical status, three serological tests
(IFAT, ELISA and DAT) and parasitological data were recorded for 151 dogs
captured in an endemic area. Sensitivity and specificity estimates from the 2x2
contingency tables were broadly corroborated by LCA, but the latter method
provided more precise estimates that were robust for the different fitted models.
It furthermore yielded a higher prevalence of infection and indicated that
parasitology was only 55% sensitive. LCA seems a promising technique for test
validation, but caution is required when applying it to sparse data sets. The
feasibility and applicability of LCA in infectious disease epidemiology is
discussed.
PMID- 10694164
TI - Seven-week interval between acquisition of a meningococcus and the onset of
invasive disease. A case report.
AB - Invasive meningococcal disease (IMD) is thought to occur within a few days of
pharyngeal acquisition of Neisseria meningitidis. During a longitudinal study of
carriage and acquisition among 2453 first-year undergraduates we identified a
male student from whom N. lactamica was isolated in October 1997 followed by N.
meningitidis in December 1997. In mid-January 1998 this student suffered a mild
episode of IMD (meningitis) during which N. meningitidis was isolated from his
CSF. The meningococcus carried in December 1997 was phenotypically and
genotypically indistinguishable from the invading organism, suggesting the
possibility that the organism may have been carried for 7 weeks prior to the
onset of invasive disease. Further studies are needed to assess more accurately
the range of asymptomatic carriage prior to disease onset.
PMID- 10694165
TI - Determination of natural versus laboratory human infection with Mayaro virus by
molecular analysis.
AB - A laboratory worker developed clinical signs of infection with Mayaro virus
(Togaviridae), an arbovirus of South and Central America, 6 days after
preparation of Mayaro viral antigen and 10 days after a trip to a rain forest.
There was no evidence of skin lesions during the antigen preparation, and level 3
containment safety measures were followed. Therefore, molecular characterization
of the virus was undertaken to identify the source of infection. RT-PCR and DNA
sequence comparisons proved the infection was with the laboratory strain.
Airborne Mayaro virus contamination is thus a hazard to laboratory personnel.
PMID- 10694166
TI - Household members of hepatitis C virus-infected people in Hafizabad, Pakistan:
infection by injections from health care providers.
AB - Household members of people with hepatitis C are at increased risk of HCV
infection. The prevalence and routes of transmission of HCV to household members
in Hafizabad, Pakistan were investigated. Household members of 24 index cases
were given a risk factor questionnaire, tested for HCV infection, and the risk
factors between the infected and uninfected were compared. Twelve of 74 household
members (16.2%) were seropositive for HCV antibody. This was 2(1/2) times the
rate of infection in the general population (OR = 2.8; P = 0.01). None of the
routes of transmission studied within the household was associated with an
increased risk. Household members who received more than 4 injections per year
were 11.9 times more likely to be infected than those who had not (P = 0.016). In
Hafizabad, the greatest risk for HCV infection to household members of infected
people is injections given by health-care workers rather than household contact
with infected persons.
PMID- 10694167
TI - Electricity-associated injuries II: outdoor management of lightning-induced
casualties.
PMID- 10694168
TI - Paramedic activities, drug administration and survival from out of hospital
cardiac arrest.
AB - OBJECTIVE: To examine the impact of administration of cardioactive drugs on the
outcome from out of hospital cardiac arrest. DESIGN: Longitudinal observational
cohort study with historical controls before and after the introduction of drug
use in cardiac arrest by paramedics. SUBJECTS: Adult patients who had sustained
an out of hospital cardiac arrest of cardiac aetiology and were treated by
paramedics. SETTING: Edinburgh, Scotland. OUTCOME MEASURES: Return of spontaneous
circulation, admission to and discharge from hospital. RESULTS: There was no
significant difference in the demographics between Period 1 (prior to drug
administration) and Period 2 (after). There was no difference in outcome between
Period 1 and Period 2 for all three parameters, return of spontaneous output 30.1
versus 35%, admission to hospital 18.9 versus 24.5% and discharge 5.8 versus
6.5%. If the presenting rhythm of VF/pulseless VT alone was considered survival
to hospital discharge was 12.1% in Period 1 and 10.3% in Period 2. CONCLUSION:
The addition of cardioactive drug administration to the treatment of out of
hospital cardiac arrest does not improve survival.
PMID- 10694169
TI - Cardiopulmonary resuscitation performance of subjects over forty is better
following half-hour video self-instruction compared to traditional four-hour
classroom training.
AB - Cardiopulmonary resuscitation (CPR) training is not well targeted to family
members of individuals at highest risk of cardiac arrest. Participants in
traditional CPR classes (TRAD) average 31 years of age, while family members of
cardiac patients average 55 years. Video self-instruction (VSI) can reach older
individuals and others who do not participate in TRAD classes. VSI is a
combination of a 34-min videotape and an inexpensive manikin intended for use in
the home, where three-quarters of all out-of-hospital cardiac arrests occur. We
exposed 202 subjects 40 years of age and older (mean age 59.4 years, S.D. = 10.9)
to either TRAD or VSI, and tested them individually immediately following
training rising validated methods including measurement by means of a Laerdal
Skillmeter manikin. According to American Heart Association (AHA) criteria, VSI
subjects performed an average of 20.8% of all compressions and 25.1% of all
ventilations correctly, compared with 3.4% of compressions and 1.7% of
ventilations by TRAD subjects (P < 0.0001). VSI subjects performed an average of
10.1 of the total 14 CPR assessment and sequence skills correctly, compared with
an average of 4.7 for TRAD (P < 0.0001). On a measure of overall performance,
62.7% of the VSI subjects were rated 'competent' or better (i.e. capable of
performing CPR that 'would probably be effective'), compared to 6.1% of TRAD
subjects (P < 0.0001). Only 17.8% of VSI subjects were rated as 'not competent'
(i.e. unable to obtain a combination of any chest rise and any compression of the
sternum) compared with 69.1% of TRAD subjects. VSI provides an effective,
convenient, and inexpensive means of training persons over 40 years of age that
achieves skill performance superior to TRAD.
PMID- 10694170
TI - A scoring system for the assessment of basic life support ability.
AB - INTRODUCTION: There are no current validated scoring systems for the assessment
of adult single rescuer basic life support (BLS) ability. A system was proposed
and prospectively validated. METHODS: The system was tested firstly on 12 skilled
BLS providers (all instructors). It was then further evaluated on 75
undergraduate dental students, who were assessed before and after a standard
training session on adult BLS. RESULTS: All 12 skilled persons passed the test
according to the system. The system successfully showed a positive training
effect in the dental students. It correctly identified those who 'passed' after
training, i.e. those were capable of providing effective BLS (71/75, 94.7%). It
also correctly identified those who were not considered competent (4/71, 5.3%).
CONCLUSION: This is a simple, effective, objective system for assessment of basic
life support. It is easily adaptable for the 1998 Guidelines on BLS.
PMID- 10694171
TI - An analysis of the efficacy of bag-valve-mask ventilation and chest compression
during different compression-ventilation ratios in manikin-simulated paediatric
resuscitation.
AB - The ideal chest compression and ventilation ratio for children during performance
of cardiopulmonary resuscitation (CPR) has not been determined. The efficacy of
chest compression and ventilation during compression ventilation ratios of 5:1,
10:2 and 15:2 was examined. Eighteen nurses, working in pairs, were instructed to
provide chest compression and bag-valve-mask ventilation for 1 min with each
ratio in random on a child-sized manikin. The subjects had been previously taught
paediatric CPR within the last 3 or 5 months. The efficacy of ventilation was
assessed by measurement of the expired tidal volume and the number of breaths
provided. The rate of chest compression was guided by a metronome set at 100/min.
The efficacy of chest compressions was assessed by measurement of the rate and
depth of compression. There was no significant difference in the mean tidal
volume or the percentage of effective chest compressions delivered for each
compression-ventilation ratio. The number of breaths delivered was greatest with
the ratio of 5:1. The percentage of effective chest compressions was equal with
all three methods but the number of effective chest compressions was greatest
with a ratio of 5:1. This study supports the use of a compression-ventilation
ratio of 5:1 during two-rescuer paediatric cardiopulmonary resuscitation.
PMID- 10694172
TI - A novel wavelet transform based analysis reveals hidden structure in ventricular
fibrillation.
AB - We report a new method of interrogating the surface ECG signal using techniques
developed in the field of wavelet transform analysis. Previously unreported
structure within the ECG during ventricular fibrillation (VF) is found using a
high-resolution decomposition of the signal employing the continuous wavelet
transform. We believe that wavelet transform methods could lead to the
development of powerful tools for use in the resuscitation of patients with
cardiac arrest.
PMID- 10694173
TI - The effects of epinephrine/norepinephrine on end-tidal carbon dioxide
concentration, coronary perfusion pressure and pulmonary arterial blood flow
during cardiopulmonary resuscitation.
AB - End-tidal CO2 concentration correlates with pulmonary blood flow during
cardiopulmonary resuscitation and has been claimed to be a useful tool to judge
the effectiveness of chest compression. A high concentration of end-tidal CO2 has
been related to a better outcome. However, most authors have noticed a decrease
in end-tidal CO2 concentration after administration of epinephrine, concomitant
with an increase in coronary perfusion pressure and an increased incidence of
return of spontaneous circulation. This study was performed to evaluate changes
in end-tidal CO2 concentration after injection of vasopressors during
cardiopulmonary resuscitation and to investigate the time-course of the response
and possible explanations for it. After 1 min of electrically induced cardiac
arrest and 5 min of chest compressions, 18 pigs were randomly assigned to receive
0.045 mg kg(-1) epinephrine, 0.045 mg kg(-1) norepinephrine or no drug. After
another 4 min of chest compressions the pigs were defibrillated. End-tidal CO2,
pulmonary blood flow and coronary perfusion pressure decreased immediately after
the induction of cardiac arrest, increased slightly during chest compressions and
increased initially to supernormal levels after the return of spontaneous
circulation. Injection of epinephrine or norepinephrine during chest compressions
decreased end-tidal CO2 51 +/- 2%, (mean +/- S.E.M.), and 43 +/- 1%,
respectively, and pulmonary blood flow by 134 +/- 13 and 125 +/- 16%,
respectively, within 1 min, simultaneously increasing coronary perfusion pressure
from 10 +/- 2 to 45 +/- 5 mm Hg and from 11 +/- 1 to 38 +/- 5 mm Hg,
respectively. The coronary perfusion pressure slowly fell, but the effects on end
tidal CO2 and pulmonary blood flow were prolonged. In conclusion, vasopressors
increased coronary perfusion pressure and the likelihood of a return of
spontaneous circulation, but decreased end-tidal CO2 concentration and induced a
critical deterioration in cardiac output and thus oxygen delivery in this model
of cardiopulmonary resuscitation.
PMID- 10694174
TI - Amniotic fluid embolism: a case report and review.
AB - A 41-year old primigravida underwent caesarean section because of foetal distress
following prostin induction of labour. Intraoperative coagulopathy, haemorrhage
and hypotension necessitated a hysterectomy. Subsequently, she developed
respiratory and renal failure, requiring mechanical ventilation and
haemodialysis. She made a full recovery. The likely diagnosis was amniotic fluid
embolism (AFE), a rare complication of pregnancy with a variable presentation,
ranging from cardiac arrest and death through to mild degrees of organ system
dysfunction with or without coagulopathy. The differential diagnosis includes pre
eclamptic toxaemia/pregnancy-induced hypertension, anaphylaxis and pulmonary
embolism. There is no diagnostic test for AFE; the finding of foetal elements in
the maternal circulation is non-specific. Historically, AFE was thought to induce
cardiovascular collapse by mechanical obstruction of the pulmonary circulation.
It is now thought that a combination of left ventricular dysfunction and acute
lung injury occur, with activation of several of the clotting factors. An
immunological basis for these effects is postulated. There is no specific therapy
and treatment is supportive. The mortality of the condition remains high.
PMID- 10694175
TI - Tracheal injury as a sequence of multiple attempts of endotracheal intubation in
the course of a preclinical cardiopulmonary resuscitation.
AB - Management of the difficult airway requires an appropriate approach based on
personal clinical experiences. For every physician involved in rescue and
emergency medicine, it is important to know the difficult airway algorithm and be
familiar with alternative techniques of managing the difficult airway. We report
a case of tracheal injury caused by multiple attempts at intubating the trachea.
Based on current knowledge, apart from surgical equipment for cricothyroidotomy
the laryngeal mask airway (LMA) and the Combitube (ETC) should be available on
any ambulance vehicle staffed by an emergency physician. In future, blind
intubation through the intubating laryngeal mask airway (ILMA) could offer a new
opportunity.
PMID- 10694176
TI - Cardiac rupture by penetration of fractured sternum: a rare complication of
cardiopulmonary resuscitation.
AB - We report an 82-year-old man in whom cardiopulmonary resuscitation (CPR) was
unsuccessful. The postmortem examination revealed right atrial ruptures and
pericardial sac perforation by a fractured sternal edge. Even though CPR-related
cardiac rupture is rare, emergency medical staff should be aware of this
complication.
PMID- 10694177
TI - Automated defibrillation performed by emergency medical technicians: the Madrid
experience.
PMID- 10694178
TI - Gel pads should not be used for monitoring ECG after defibrillation.
PMID- 10694179
TI - An intact renin-angiotensin system is a prerequisite for normal renal
development.
AB - All components of the renin-angiotensin system (RAS) are highly expressed in the
developing kidney in a pattern that suggests a role for angiotensin II in renal
development In support of this notion, pharmacological interruption of
angiotensin II type-1 (AT1) receptor-mediated effects in animals with an ongoing
nephrogenesis produces specific renal abnormalities characterized by papillary
atrophy, abnormal wall thickening of intrarenal arterioles, tubular atrophy
associated with expansion of the interstitium, and a marked impairment in urinary
concentrating ability. Similar changes in renal morphology and function also
develop in mice with targeted inactivation of the genes that encode
angiotensinogen, angiotensin converting enzyme, or both AT1 receptor isoforms
simultaneously. Taken together, these results clearly indicate that an intact
signalling through AT1 receptors is a prerequisite for normal renal development
In a recent study, an increased incidence of congenital anomalies of the kidney
and urinary tract was detected in mice deficient in the angiotensin II type-2
receptor, suggesting that this receptor subtype is also involved in the
development of the genitourinary tract The present report mainly reviews the
renal abnormalities that have been induced by blocking the RAS pharmacologically
or by gene targeting in experimental animal models. In addition, pathogenetic
mechanisms and clinical implications are discussed.
PMID- 10694180
TI - Relationship between blood pressure level and mortality rate: an 18-year study
conducted in two rural communities in Japan.
AB - BACKGROUND: There have been very few studies on life prognosis of cardiovascular
disease according to blood pressure stratification in the Japanese. Therefore, in
Japan, although treatment of hypertension is possible, albeit at times difficult,
due to the availability of various antihypertensive medications, the appropriate
time at which treatment should be started remains a problem. OBJECTIVE: To
investigate the long-term prognosis of cardiovascular disease in the Japanese
general population according to blood pressure stratification in the Japanese.
DESIGN: A community-based prospective cohort study of 1996 men and women between
the ages of 40 and 64 years at the baseline examination was conducted over an 18
year period. Information on death was obtained from local public health nurses
and death certificates. The causes of death were clarified by questionnaires sent
to doctors in the hospital in which the deceased was hospitalized, and the causes
of death were analysed in each blood pressure category at baseline examination.
RESULTS: Mortality from cardiovascular disease increased with increases in the
level of blood pressure and was significantly higher in > or = 140 mmHg group in
systolic blood pressure and > or = 90 mmHg group in diastolic blood pressure,
adjusted for age, sex and other cardiovascular risk factors in the Japanese
general population. However, mortality risk from cardiovascular disease did not
have a J-shaped relationship with systolic and diastolic blood pressure.
CONCLUSION: We conclude that the optimum time for starting treatment in Japanese
people is when blood pressure is 140/90 mmHg or less.
PMID- 10694181
TI - Hypertension prevalence and care in an urban and rural area of Tanzania.
AB - OBJECTIVE: To describe the prevalence, detection, treatment and control of
hypertension in an urban and rural area of Tanzania. DESIGN: Two linked cross
sectional population-based surveys. SETTING: A middle-income urban district of
Dar es Salaam (Ilala) and a village in the relatively prosperous rural area of
Kilimanjaro (Shari). PARTICIPANTS: Seven hundred and seventy adults (> 15 years)
in Ilala and 928 adults in Shari were studied. RESULTS: Hypertension prevalence
(blood pressure > or = 140 and/or 90 mmHg, or known hypertensives receiving anti
hypertensive treatment) was 30% (95% confidence interval, 25.1-34.9%) in men and
28.6% (24.3-32.9%) in women in Ilala, and 32.2% (27.7-36.7%) in men and 31.5%
(27.8-35.2%) in women in Shari. Age-standardized hypertension (to the New World
Population) prevalence was 37.3% (32.2-42.5%) among men and 39.1% (34.2-44.0%) in
women in Ilala, and 26.3% (22.4-30.4%) in men and 27.4% (24A-30.4%) in women in
Shari. In both areas, just under 20% of hypertensive subjects were aware of their
diagnosis, approximately 10% reported receiving treatment and less than 1% were
controlled (blood pressure < 140/90 mmHg). Hypertensive subjects were older, had
greater body mass indices and waist: hip ratios, and had more risk factors for
hypertension and its complications (smoking, heavy alcohol consumption, physical
inactivity, obesity and diabetes) than non-hypertensives. CONCLUSIONS: There is a
high prevalence of hypertension in rural and urban areas of Tanzania, with low
levels of detection, treatment and control. This demonstrates the need for cost
effective strategies for primary prevention, detection and treatment of
hypertension and the growing public health challenge of non-communicable diseases
in Sub-Saharan Africa.
PMID- 10694182
TI - Defensiveness status predicts 3-year incidence of hypertension.
AB - OBJECTIVE: A growing body of research indicates that defensive personality styles
(in particular, self-deception) may be related to higher resting blood pressure
and stress reactivity levels. This study is the first, however, to examine the
value of defensiveness as a prognostic indicator for the development of clinical
hypertension. METHODS: Participants were 127 initially normotensive male and
female adults who completed a comprehensive protocol including psychological
testing, assessment of smoking, physical activity and body fat levels, and 8-12 h
ambulatory blood pressure monitoring. Participants returned 3-years later for an
identical follow-up protocol. Defensiveness was assessed using the Balanced
Inventory of Desirable Responding. RESULTS: At 3-year testing, 15 of 127
participants (12%) met criteria for hypertension (i.e. ambulatory mean blood
pressure > 140/90). Comparisons between defensiveness groups showed that 12 of 60
(20%) high defensiveness participants met hypertension criteria, whereas only
three of 67 (4.5%) low defensiveness participants were hypertensive. Logistic
regression equations adjusted for age, alcohol usage, bodyfat, self-reported
exercise levels, smoking, and year-1 ambulatory blood pressure, revealed that
membership in the high defensiveness group was associated with more than a
sevenfold risk of 3-year hypertension (adjusted risk ratio, 7.5; 95% confidence
interval, 1.5-39.2). CONCLUSIONS: These findings link defensive characteristics
to an increased prospective risk of hypertension using state of the art
ambulatory monitoring techniques, and were robust after controlling for
established risk factors. We conclude that the current results add to the
hypertension literature by demonstrating associations between personality and
clinically relevant blood pressure criteria.
PMID- 10694183
TI - Analysis of the genetic basis of the endothelium-dependent impaired
vasorelaxation in the stroke-prone spontaneously hypertensive rat: a candidate
gene approach.
AB - OBJECTIVE: To investigate the role of potential candidate genes in the
pathogenesis of the endothelium-dependent impaired vasorelaxation that associates
and co-segregates with stroke in the stroke-prone spontaneously hypertensive rat
(SHRsp) compared with the stroke-resistant SHR (SHRsr). DESIGN AND METHODS: An
SHRsp/SHRsr F2-intercross (n = 137; 64 males, 73 females) was obtained and, at
the age of 6 weeks, it was placed under a stroke permissive Japanese-style diet
for 4 weeks. At the end of the treatment the vascular function of each rat was
characterized. The maximal vasorelaxation to acetylcholine after maximal
vasoconstriction (delta ratio) was considered as the quantitative phenotype. The
following candidate genes were related to the delta ratio: renin,
angiotensinogen, angiotensin-converting enzyme, angiotensin II AT1b receptor,
atrial natriuretic peptide, brain natriuretic peptide, atrial natriuretic peptide
GC-A receptor, kallikrein, endothelial nitric oxide synthase. In addition,
polymorphic markers located inside areas of the rat genome where other candidates
(i.e. adrenomedullin, endothelin, Ang II AT1a receptor) are known to map were
included. RESULTS: The endothelial vascular dysfunction of the SHRsp showed a
variable distribution among SHRsp/SHRsr F2 descendants, independently from the
blood pressure levels. A genotype/phenotype co-segregation analysis for each of
the genes tested did not show any statistically significant co-segregation with
the vascular phenotype. CONCLUSION: A candidate gene approach used to investigate
the genetic basis of the endothelial-dependent vascular dysfunction of the SHRsp
strain did not reveal any evidence to support the hypothesis that the genes
tested play any role in the pathogenesis of the stroke-related vascular
abnormality.
PMID- 10694184
TI - Association analysis of beta2 adrenoceptor polymorphisms with hypertension in a
Black African population.
AB - OBJECTIVE: To determine whether or not beta2 adrenoceptor polymorphism is a risk
factor for the development of hypertension in a Black South African population.
BACKGROUND: Attenuated vasodilator responses to endogenous catecholamines may
contribute to the aetiology of hypertension. Downregulation of beta2
adrenoreceptors (beta2AR) following stimulation with agonists is determined in
part by variation at the beta2AR gene locus. The Glu27 beta2AR genotype results
in attenuated downregulation compared with the wild-type Gln27 receptor, whereas
Gly16 exhibits enhanced down-regulation compared to Arg16. Possible racial
differences in the prevalence of the beta2AR polymorphisms may be an explanation
for the blunted responses to isoprenaline and the increased prevalence of
hypertension in Black African populations. METHODS: One hundred and ninety-two
unrelated hypertensives and 123 normotensives of Black South African origin were
studied. Hypertensives were recruited from hospital hypertension clinics in the
province of Gauteng and if on treatment, had a 2-4 week washout period before 24
h ambulatory blood pressure assessment Normotensive controls were recruited from
the same community. RESULTS: There was no significant association between either
the Arg-Gly16 polymorphism or the Gln-Glu27 polymorphism and hypertension status.
Furthermore, in the hypertensives, no significant association was seen between
beta2AR genotype at either site and clinical blood pressure, 24-h blood pressure
or left ventricular mass. A significant association was seen between Arg16
homozygotes and lower body mass index in hypertensives (P = 0.007) although this
was not a primary end point. Interestingly, the Glu27 polymorphism was much rarer
in this population (allelic frequency 17%) compared to a Caucasian population.
CONCLUSION: These data suggest that beta2AR polymorphism is not a risk factor for
hypertension per se in this defined population. The possibility that the
decreased prevalence of Glu27 in black South African populations explains blunted
vasodilator responses to isoprenaline requires further study.
PMID- 10694185
TI - The L10F mutation of angiotensinogen is rare in pre-eclampsia.
AB - BACKGROUND: A mutation in the gene for angiotensinogen, changing the leucine
residue at position 10 to a phenylalanine (L10F), has been reported in a patient
with proteinuric pre-eclampsia. In vitro enzymatic studies suggest this mutation
would increase production of the vasoactive peptide, angiotensin II in vivo, and
therefore explain the etiology of the maternal hypertension. OBJECTIVE: To
determine whether mutation of codon 10 of angiotensinogen is common in pre
eclampsia, and therefore likely to be involved in disease susceptibility. DESIGN:
We collected a cohort of 32 women with 'true' pre-eclampsia. All were
normotensive prior to the 20th week of pregnancy, developed blood pressures
consistently above 140/90 mmHg and had proteinuria of greater than 300 mg/day
during the third trimester. All had blood pressures that returned to normal
within 1 month of delivery; 31 women were primigravida. Genomic DNA was isolated
from their peripheral blood lymphocytes for genetic analyses. METHODS: A
polymerase chain reaction-restriction enzyme-based assay was devised to screen
for mutation of codon 10 of the angiotensinogen gene. In addition, we determined
the frequency of a threonine residue at position 235 in the angiotensinogen gene,
given previous controversial findings of association of this polymorphism with
disease. CONCLUSIONS: We detected no mutation of codon 10 in angiotensinogen in
any of the 32 women studied, indicating that this mutation is not commonly
associated with proteinuric pre-eclampsia. Furthermore, there was no increased
frequency of threonine 235 in the affected individuals studied compared with
respective normotensive Caucasian-American and African-American populations.
PMID- 10694186
TI - Acute production of vascular superoxide by angiotensin II but not by
catecholamines.
AB - OBJECTIVE: To determine whether vascular superoxide is rapidly released by
angiotensin II and is involved in vascular contraction. DESIGN: The effect of
superoxide dismutase (SOD) on angiotensin II induced elevation of mean arterial
blood pressure was measured. Subsequently, acute production of vascular
superoxide by angiotensin II and its effect on isometric tension were measured in
rat aortic rings. The effects of catecholamines were concomitantly measured.
METHODS AND RESULTS: The acute pressor effects of angiotensin II were
significantly reduced when rats were pretreated intravenously with SOD. When
angiotensin II was added on aortic segments in the presence of Cypridina
luciferin analog, immediate elevations of chemiluminescence were observed which
were inhibited by SOD. Furthermore, angiotensin II-induced elevations of
isometric tension in aortic rings were significantly reduced by SOD. The effects
of epinephrine and norepinephrine were concomitantly measured and were not
significant CONCLUSIONS: The acute superoxide producing effect is likely to be
specific to angiotensin II, because such a significant modification of the
effects was not observed for catecholamines. Our results suggest that angiotensin
II causes acute vascular superoxide production, which may be involved in the
acute pressor effects.
PMID- 10694187
TI - Effect of antioxidant treatments on nitrate tolerance development in normotensive
and hypertensive rats.
AB - OBJECTIVES: To investigate the effect of chronic antioxidant treatments on the
development of nitrate tolerance in spontaneously hypertensive (SHR) and
normotensive Wistar-Kyoto (WKY) rats by evaluating (i) coronary vascular
reactivity, (ii) lipid peroxidation (malondialdehyde), and (iii) peroxynitrite
formation (3-nitrotyrosine). METHODS: Tolerance was induced in 16-week-old male
SHR and WKY, by 4 days of continuous treatment with nitroglycerin patches. Two
groups were orally pre-treated (2-weeks) with antioxidants: N-acetyl-L-cysteine
(NAC) or melatonin. Effects of serotonin (5-HT) and sodium nitroprusside (SNP)
perfusion were tested in isolated Langendorff-perfused hearts. 3-Nitrotyrosine
levels were measured in coronary sinus effluent and malondialdehyde in plasma.
RESULTS: Nitrate tolerance reduced SNP-induced dilation in both strains. This
alteration was differently improved by antioxidants: melatonin was effective in
SHR, whereas NAC was effective in WKY. Tolerance also reduced 5-HT-mediated
vasodilation in WKY, which was reversed by both antioxidants. By contrast,
nitrate tolerance enhanced the vasoconstriction to 5-HT in SHR and both
antioxidants prevented this response. Furthermore, tolerance was associated with
higher malondialdehyde levels in both strains and with higher 3-nitrotyrosine
levels in SHR. These changes were reversed by both antioxidants. CONCLUSIONS: A
participation of oxidative stress was suggested during nitrate tolerance
development, since antioxidants prevented the increase in lipid peroxidation and
improved vascular responses to SNP and 5HT. Differential effects of antioxidants
on SNP-induced vasodilation in SHR and WKY may suggest distinct mechanisms of
tolerance development in hearts from hypertensive and normotensive rats. An
increased peroxynitrite generation, expressed by higher 3-nitrotyrosine levels,
could contribute to nitrate tolerance in the coronary circulation of SHR.
PMID- 10694188
TI - Baseline reproducibility of B-mode ultrasonic measurement of carotid artery
intima-media thickness: the European Lacidipine Study on Atherosclerosis (ELSA).
AB - BACKGROUND AND OBJECTIVE: The European Lacidipine Study of Atherosclerosis (ELSA)
is a prospective, randomized, double-blind, multi-national interventional trial
to determine the effect of four-year treatment using the calcium antagonist
lacidipine versus the beta-blocker atenolol on the progression of carotid
atherosclerosis in 2259 asymptomatic hypertensive patients. B-mode ultrasound is
used to measure the primary and secondary endpoints including the mean maximum
intima-media thickness (IMT) of the carotid bifurcations and the common carotid
arteries (CBM(max)), the mean maximum IMT of 12 standard carotid sites (M(max))
and the overall maximum IMT (T(max)). This paper reports the cross-sectional
reproducibility of ultrasound measurements at baseline. METHOD: To evaluate
measurement reliability, each patient is scanned twice at baseline and again at
four annual visits, with 80% of the replicate scans performed by the same
sonographer and 20% by a different sonographer; 50% of the replicate scans are
read by the same reader and the other 50% by different readers. RESULTS: The
overall coefficient of reliability (R) was 0.859 for CBM(max), 0.872 for M(max)
and 0.794 for T(max). The reliability for CBM(max) was stable during the 1 3/4
year baseline period (R = 0.848 to 0.953) and was uniform among the 23 field
centres (R = 0.798 to 0.926). Intra- and inter-reader reliability were 0.915 and
0.872 respectively, and intra-sonographer reliability was 0.866. CONCLUSION: The
results demonstrate that by implementing standardized protocols and strict
quality control procedures, highly reliable ultrasonic measurements of carotid
artery IMT can be achieved in large multi-national trials.
PMID- 10694189
TI - Evidence for a sympatholytic effect of mibefradil in the pithed rat preparation.
AB - OBJECTIVE: The T-type prevalent calcium channel blocker mibefradil (MIB) was
shown to possess N-type calcium channel blocking properties. As this particular
type of calcium channel is known to be crucially involved in the neuronal release
of noradrenaline, we have investigated whether MIB could be a sympatholytic drug.
METHODS: To evaluate the sympathoinhibitory action, the effects of 3 and 10
micromol/kg MIB on the tachycardic effect of electrical stimulation of the
preganglionic cardioaccelerator nerves in the pithed rat were investigated. The
effect of MIB on the dose-response curve of externally applied noradrenaline was
also studied. To compare the results with a classic L-type calcium channel
blocker, the experiments were repeated with 3 and 10 micromol/kg verapamil (VER).
RESULTS: The maximal increase in heart rate in response to electrical nerve
stimulation was 96 +/- 7 bpm (control, n = 6), 70 +/- 6 bpm (3 micromol/kg MIB, n
= 8), 57 +/- 6 bpm (10 micromol/kg MIB, n = 5), 93 +/- 5 bpm (3 micromol/kg VER,
n = 6) and 46 +/- 7 bpm (10 micromol/kg VER, n = 5). The tachycardic response to
electrical stimulation at 1, 5 and 10 Hz was completely blocked by 5 mg/kg
intravenous guanethidine. The maximal increase in heart rate in response to
noradrenaline was 96 +/- 4 bpm (control, n = 6), 103 +/- 6 (3 micromol/kg MIB, n
= 6), 42 +/- 9 bpm (10 micromol/kg MIB, n = 5), 73 +/- 5 bpm (3 micromol/kg VER,
n = 5) and 40 +/- 7 bpm (10 micromol/kg VER, n = 6). Under control conditions and
in the presence of 3 micromol/kg MIB and VER the maximal effect of noradrenaline
was reached at 0.1 micromol/kg whereas in the presence of 10 micromol/kg MIB and
VER it was reached at a dose of 1 micromol/kg. MIB at a dose of 3 micromol/kg was
significantly more effective in reducing the chronotropic response to electrical
stimulation compared with externally applied noradrenaline. For VER the opposite
holds true. These differences were not observed with doses of 10 micromol/kg MIB
and VER. CONCLUSION: Mibefradil, besides its direct effect on cardiac T- and L
type calcium channels, reduces the release of noradrenaline from sympathetic
nerve endings, most probably by inhibition of presynaptic N-type calcium
channels. In the model used this effect is only observable at relatively low
concentrations, most probably because of the direct cardiodepressant action of
MIB provoked by L-type channel blockade.
PMID- 10694190
TI - Cicletanine reverses vasoconstriction induced by the endogenous sodium pump
ligand, marinobufagenin, via a protein kinase C dependent mechanism.
AB - RATIONALE: Cicletanine (CIC), an anti-hypertensive compound with direct vascular
and natriuretic actions, is especially effective in salt-sensitive hypertension,
in which dysregulation of the sodium pump plays an important pathogenic role, and
digitalis-like cardiotonic steroids contribute to increased vascular tone. The
purpose of the present study was to investigate whether, and by what mechanisms,
cicletanine antagonizes the vasoconstrictor effects of cardiotonic steroids in
isolated human arteries. METHODS: The effects of cicletanine on vascular tone
were studied in isolated, endothelium-denuded rings of 2nd-3rd-order branches of
human mesenteric arteries pre-contracted with bufodienolide marinobufagenin
(MBG), an Na/K-ATPase inhibitor, or endothelin-1 (ET-1). Na/K-ATPase activity was
measured in sarcolemmal membranes from the mesenteric artery. Activity of rat
brain protein kinase C (PKC) was measured using the PepTag phosphorylation assay.
RESULTS: MBG and ET-1 both induced sustained vasoconstriction in human mesenteric
artery rings, and cicletanine relaxed rings pre-contracted with either MBG (EC50
= 11 +/- 2 micromol/l) or ET-1 (EC50 = 6.4 +/- 1.1 micromol/l). Although 8-Br
cGMP (100 micromol/l) caused complete vasorelaxation of arterial rings pre
contracted with ET-1, it did not affect the MBG-induced vasoconstriction. An
activator of PKC, phorbol diacetate (PDA) (50 nmol/l), attenuated CIC-induced
vasorelaxation of mesenteric artery rings pre-contracted with MBG (EC50 > 100
micromol/l), but not rings pre-contracted with ET-1 (EC50 = 6.5 +/- 1.2
micromol/l). In mesenteric artery sarcolemma, 100 nmol/l MBG inhibited the Na/K
ATPase by 68 +/- 5% and cicletanine (100 micromol/l) attenuated this Na/K-ATPase
inhibition by 85 +/- 6%. In the PepTag PKC assay, cicletanine produced a
concentration-dependent inhibition of rat brain PKC activity (IC50 45 +/- 11
micromol/l). In the presence of 50 nmol/l PDA, 100 micromol/l cicletanine did not
antagonize the Na/K-ATPase inhibition by MBG, and did not inhibit the PKC from
rat brain. CONCLUSIONS: Cicletanine antagonizes vasoconstriction induced by Na/K
ATPase inhibition via a PKC-dependent mechanism that does not involve inhibition
of cyclic GMP phosphodiesterase (cGMP-PDE). This mechanism of action may be
relevant to the greater potency of cicletanine in salt-sensitive hypertension in
which plasma levels of endogenous digitalis-like cardiotonic steroids are
elevated. Our findings also suggest that PKC is an important factor for
cardiotonic steroid-Na/K-ATPase interactions on the vascular tone, and is
therefore a potential target for therapeutic intervention in hypertension.
PMID- 10694191
TI - Platelet alpha2-adrenoceptor alterations in patients with essential hypertension
are normalized after treatment with doxazosin but not propranolol.
AB - OBJECTIVE: Marked alterations have been demonstrated to occur in the platelet
alpha2-adrenoceptors of patients with essential hypertension. The purpose of this
study was to determine whether antihypertensive treatment with alpha-adrenergic
blocker doxazosin or beta-adrenergic blocker propranolol can affect the affinity
and the density of platelet alpha2-adrenoceptors in such patients. SUBJECTS AND
METHODS: In two groups of 22 previously untreated, essential hypertensive
patients, the mean affinity (Kd) and density (B(max)) of platelet alpha2
adrenoceptors were studied by [3H]-UK 14304 binding assays; the first assays were
performed before any medication was begun, the second were performed after
treatment for up to 13 weeks with doxazosin or propranolol. A third group of 22
healthy normotensive volunteers matched by age, sex and body mass index was used
as control. RESULTS: Blood pressure did not differ significantly in the two
hypertensive groups, and treatment with the two drugs resulted in closely
similar, normal blood pressure levels. Kd and B(max) values were significantly
higher in the two hypertensive groups than in controls. After treatment with
propranolol the binding parameters did not change significantly, whereas after
treatment with doxazosin Kd and B(max) returned to normotensive values.
CONCLUSIONS: In previously untreated, essential hypertensive patients platelet
alpha2-adrenoceptors have a lower affinity but a higher density than in
normotensive subjects. Despite similar effects on blood pressure, the treatment
with the alpha-adrenergic blocker doxazosin is followed by restoration of normal
findings in the binding assays of platelet alpha2-adrenoceptors whereas the
treatment with the beta-adrenergic blocker propranolol does not alter the Kd and
B(max) values.
PMID- 10694192
TI - Myocardial bradykinin B2-receptor expression at different time points after
induction of myocardial infarction.
AB - OBJECTIVE: To characterize the regulation of the myocardial bradykinin B2
receptor after induction of myocardial infarction (MI), we studied its expression
at different time points in the left ventricle (LV), right ventricle (RV) and
interventricular septum (S) of the heart. DESIGN: Male Sprague-Dawley rats were
submitted to permanent occlusion of the left descending coronary artery. Six
hours, 24 h or 6 days after MI induction or a sham operation, a Millar-tip
catheter was placed in the LV. Left ventricular pressure (LVP) and contractility
[(dP/dt)max] were measured. The LV, RV and S of all animals were isolated, and
total RNA was extracted. B2-receptor expression was analysed by an RNase
protection assay. In addition, Western blot analysis was used to determine
protein levels of the B2 receptor in the infarcted area of the LV. RESULTS: We
observed a decrease in LVP and contractility at all time points after MI in
comparison with sham-operated animals. Basal B2-receptor expression was detected
in the LV and RV, but not in the S of sham-operated rats. In the LV of infarcted
hearts, we found a time-dependent up-regulation of the B2-receptor expression,
which was increased twofold and fivefold, respectively, 6 h and 24 h after
induction of MI compared with controls. This increase was maintained for at least
6 days. Similarly, we also found an up-regulation of the B2-receptor expression
in the RV and S. Both reached a peak 24 h after induction of MI. The protein
level of the receptor gradually increased up to day 6. CONCLUSION: We conclude
that myocardial ischaemia triggers B2-receptor up-regulation in both the
infarcted and non-infarcted areas of the heart.
PMID- 10694193
TI - Effects of oral administration of L-arginine on renal function in patients with
heart failure.
AB - OBJECTIVES: Although the beneficial effects of L-arginine on systemic
haemodynamics have been reported in patients with heart failure, its effect on
renal function has not been examined. We evaluated the effects of oral
administration of L-arginine on renal haemodynamics, sodium and water handling,
and various hormonal factors in patients with chronic heart failure. SUBJECTS AND
METHODS: A double-blind crossover trial was performed in 17 patients with chronic
congestive heart failure (NYHA II-III, 56 +/- 12 years of age) who were randomly
assigned to receive oral L-arginine (15 g/day) and placebo or placebo and
arginine sequentially for 5 days each. Twenty-four hour creatinine clearance
(Ccr), and 24-h urinary cyclic guanosine 5-monophosphate (GMP) excretion were
determined. Saline loading was performed on day 5 of each treatment Renal blood
flow, glomerular filtration rate (GFR), and urinary sodium excretion rate (UNa)
were assessed before and after saline loading. RESULTS: Twenty-four hour GMP
excretion (1.4 +/- 1.1 versus 0.8 +/- 0.5 micromol/day, P < 0.01) and Ccr (150 +/
43 versus 125 +/- 42 ml/min, P < 0.05) were higher and plasma endothelin level
(2.5 +/- 0.6 versus 3.1 +/- 0.8 pg/ml, P < 0.05) was lower with L-arginine
treatment compared to placebo treatment In addition, the relative increase of UNa
and GFR after saline loading were significantly higher in L-arginine treatment
(UNa, 47 +/- 12%; GFR, 44 +/- 31%) than in placebo treatment (UNa, 34 +/- 9%;
GFR, 22 +/- 29%) (P < 0.05). CONCLUSIONS: Oral administration of L-arginine has
beneficial effects on glomerular filtration rate, natriuresis, and plasma
endothelin level in patients with chronic congestive heart failure.
PMID- 10694194
TI - Structure and the resistance amplifier in hypertension: reply to the dissenters.
PMID- 10694196
TI - A(2A) adenosine receptors in human peripheral blood cells.
PMID- 10694197
TI - Role of nitric oxide- and vasoactive intestinal polypeptide-containing neurones
in human gastric fundus strip relaxations.
AB - The morphological pattern and motor correlates of nitric oxide (NO) and
vasoactive intestinal polypeptide (VIP) innervation in the human isolated gastric
fundus was explored. By using the nicotinamide adenine dinucleotide phosphate
hydrogen (NADPH)-diaphorase and specific rabbit polyclonal NO-synthase (NOS) and
VIP antisera, NOS- and VIP-containing varicose nerve fibres were identified
throughout the muscle layer or wrapping ganglion cell bodies of the myenteric
plexus. NOS-immunoreactive (IR) neural cell bodies were more abundant than those
positive for VIP-IR. The majority of myenteric neurones containing VIP
coexpressed NADPH-diaphorase. Electrical stimulation of fundus strips caused
frequency-dependent NANC relaxations. N(G)-nitro-L-arginine (L-NOARG: 300 microM)
enhanced the basal tone, abolished relaxations to 0.3 - 3 Hz (5 s) and those to 1
Hz (5 min), markedly reduced ( approximately 50%) those elicited by 10 - 50 Hz,
and unmasked or potentiated excitatory cholinergic responses at frequencies > or
=1 Hz. L-NOARG-resistant relaxations were virtually abolished by VIP (100 nM)
desensitization at all frequencies. Relaxations to graded low mechanical
distension (< or =1 g) were insensitive to tetrodotoxin (TTX: 1 microM) and L
NOARG (300 microM), while those to higher distensions (2 g) were slightly
inhibited by both agents to the same extent ( approximately 25%). In the human
gastric fundus, NOS- and VIP immunoreactivities are colocalized in the majority
of myenteric neurones. NO and VIP mediate electrically evoked relaxations: low
frequency stimulation, irrespective of the duration, caused NO release only,
whereas shortlasting stimulation at high frequencies induced NO and VIP release.
Relaxations to graded mechanical distension were mostly due to passive
viscoelastic properties, with a slight NO-mediated neurogenic component at 2 g
distension. The difference between NO and VIP release suggests that in human
fundus accommodation is initiated by NO. British Journal of Pharmacology (2000)
129, 12 - 20
PMID- 10694198
TI - Adverse effects of an active fragment of parathyroid hormone on rat hippocampal
organotypic cultures.
AB - Adverse effects of an active fragment of parathyroid hormone (PTH(1 - 34)), a
blood Ca(2+) level-regulating hormone, were examined using rat hippocampal slices
in organotypic culture. Exposure of cultured slice preparations to 0.1 microM
PTH(1 - 34) for 60 min resulted in a gradual increase in the intracellular Ca(2+)
concentration ([Ca(2+)](i)); this effect was most obvious in the apical dendritic
region of CA1 subfield. When PTH(1 - 34) at a lower concentration (1 nM) was
added to the culture medium and its toxic effects examined using a propidium
iodide intercalation method, significant toxicity was seen 3 days after exposure
and increased with time. Cells in the CA1 region seemed more vulnerable to the
hormone than cells in other regions. At 1 week of exposure, the toxic effects
were dose-dependent over the range of 0.1 pM to 0.1 microM, the minimum effective
dose being 10 pM. The adverse effects were not induced either by the inactive
fragment, PTH(39 - 84), or by an active fragment of PTH-related peptide (PTHrP(1
34)), an intrinsic ligand of the brain PTH receptor. The PTH(1 - 34)-induced
adverse effects were significantly inhibited by co-administration of 10 microM
nifedipine, an L-type Ca(2+) channel blocker, but not by co-administration of
blockers of the other types of Ca(2+) channel. The present study demonstrates
that sustained high levels of PTH in the brain might cause degeneration of
specific brain regions due to Ca(2+) overloading via activation of
dihydropyridine-sensitive Ca(2+) channels, and suggests that PTH may be a risk
factor for senile dementia. British Journal of Pharmacology (2000) 129, 21 - 28
PMID- 10694199
TI - Stimulation of the ventral tegmental area enhances the effect of vasopressin on
blood pressure in conscious rats.
AB - The mesolimbic dopamine system projects to a large number of forebrain areas and
plays an important role in the regulation of locomotor activity, cognition and
reward. We previously found evidence for a functional interaction between the
mesolimbic dopamine system and circulating vasopressin and the present study was
performed to test the hypothesis that mesolimbic dopamine stimulation modulates
the cardiovascular effects of vasopressin. Sprague-Dawley rats were
stereotaxically implanted with a guide cannula into the region of origin of the
mesolimbic system, the ventral tegmental area, and instrumented with catheters
into the abdominal aorta and jugular vein. One week later, separate groups of
conscious rats were injected intravenously with 1, 3 or 10 ng kg(-1) of arginine
vasopressin or other vasopressor drugs before and after intra-ventral tegmental
area injection of 10 nmol of neurotensin. Intra-ventral tegmental area injections
of neurotensin had no significant effect on mean arterial pressure and heart rate
but significantly potentiated the pressor response to intravenous administration
of vasopressin when compared to saline-injections. However, the vasopressin
induced bradycardia was unaffected. Intravenous pretreatment with raclopride
blocked the ability of neurotensin, injected into the ventral tegmental area, to
potentiate the vasopressin-induced pressor response. Intra ventral tegmental area
injections of neurotensin had no effect on the pressor response and bradycardia
induced by intravenous angiotensin II or methoxamine. In conclusion, these
results suggest that the mesolimbic dopamine system, in addition to its well
known role in the regulation of behaviour, modulates cardiovascular control by
potentiating the effects of vasopressin on mean arterial pressure. British
Journal of Pharmacology (2000) 129, 29 - 36
PMID- 10694201
TI - Effects of omega-conotoxin GVIA and diltiazem on double peaked vasoconstrictor
responses to periarterial electric nerve stimulation in isolated canine splenic
artery.
AB - The actions of omega-conotoxin (omega-CTX) and diltiazem on adrenergic and
purinergic components of double peaked vasoconstrictor responses to periarterial
nerve stimulation have been investigated in the isolated, perfused canine splenic
arterial preparation. Double peaked vasoconstrictions (biphases of
vasoconstrictors) were consistently observed in the conditions of 30 s trains of
pulses at 1 - 10 Hz frequencies. omega-CTX (1 - 30 nM) produced similar
inhibitory effects on the first phase and second phase responses in a dose
related manner. Thirty nM omega-CTX almost completely inhibited the biphasic
vasoconstrictions at any used frequencies but did not affect the vasoconstrictor
responses to exogenous applied ATP (0.01 - 1 micromol) and noradrenaline (0.03 -
3 nmol). Intraluminal application of a large dose of diltiazem (3 - 10 microM)
also produced a dose-dependent inhibitory effect on biphasic vasoconstrictions at
any used frequencies. Three microM diltiazem exerted rather a larger inhibitory
effect on the second phase than the first phase response at low frequencies (1 -
3 Hz), but a similar inhibition on first and second phasic responses at high
frequencies (6 - 10 Hz). An extremely high dose of diltiazem (10 microM) almost
completely inhibited the biphasic vasoconstrictor responses to nerve stimulation,
and slightly inhibited the contractile responses to exogenous applied ATP (0.01 -
1 micromol) and noradrenaline (0.03 - 3 nmol). The present results indicate that
omega-CTX selectively acts prejunctionally to inhibit the release of transmitters
from sympathetic nerve terminals, and omega-CTX-sensitive calcium channels may
produce a parallel controlling of purinergic and adrenergic components of
sympathetic cotransmission. A large dose of diltiazem has inhibitory effects on
both prejunctional and postjunctional sympathetic co-transmission. British
Journal of Pharmacology (2000) 129, 47 - 52
PMID- 10694200
TI - [(125)I]-GR231118: a high affinity radioligand to investigate neuropeptide Y Y(1)
and Y(4) receptors.
AB - GR231118 (also known as 1229U91 and GW1229), a purported Y(1) antagonist and Y(4)
agonist was radiolabelled using the chloramine T method. [(125)I]-GR231118
binding reached equilibrium within 10 min at room temperature and remained stable
for at least 4 h. Saturation binding experiments showed that [(125)I]-GR231118
binds with very high affinity (K(d) of 0.09 - 0.24 nM) in transfected HEK293
cells with the rat Y(1) and Y(4) receptor cDNA and in rat brain membrane
homogenates. No specific binding sites could be detected in HEK293 cells
transfected with the rat Y(2) or Y(5) receptor cDNA demonstrating the absence of
significant affinity of GR231118 for these two receptor classes. Competition
binding experiments revealed that specific [(125)I]-GR231118 binding in rat brain
homogenates is most similar to that observed in HEK293 cells transfected with the
rat Y(1), but not rat Y(4), receptor cDNA. Autoradiographic studies demonstrated
that [(125)I]-GR231118 binding sites were fully inhibited by the Y(1) antagonist
BIBO3304 in most areas of the rat brain. Interestingly, high percentage of
[(125)I]-GR231118/BIBO3304-insensitive binding sites were detected in few areas.
These [(125)I]-GR231118/BIBO3304-insensitive binding sites likely represent
labelling to the Y(4) receptor subtype. In summary, [(125)I]-GR231118 is a new
radiolabelled probe to investigate the Y(1) and Y(4) receptors; its major
advantage being its high affinity. Using highly selective Y(1) antagonists such
as BIBO3304 or BIBP3226 it is possible to block the binding of [(125)I]-GR231118
to the Y(1) receptor allowing for the characterization and visualization of the
purported Y(4) subtype. British Journal of Pharmacology (2000) 129, 37 - 46
PMID- 10694202
TI - Effects of superoxide anion generators and thiol modulators on nitrergic
transmission and relaxation to exogenous nitric oxide in the sheep urethra.
AB - The effects of superoxide anion generators, the nitric oxide (NO) scavenger 2-(4
carboxyphenyl)-4,4,5,5-tetramethylimidazoine-1-oxyl 3-oxide (carboxy-PTIO), the
specific guanylate cyclase inhibitor 1H-[1,2,4]-oxadiazole-[4,3-a]-quinoxalin-1
one (ODQ), and thiol modulating agents were investigated on relaxations induced
by nitrergic stimulation and exogenous NO addition in the sheep urethra.
Methylene blue (MB, 10 microM), pyrogallol (0.1 mM) and xanthine (X, 0.1
mM)/xanthine oxidase (XO, 0.1 u ml(-1)) inhibited NO-mediated relaxations,
without affecting those induced by nitrergic stimulation. This resistance was not
diminished following inhibition of endogenous Cu/Zn superoxide dismutase (Cu/Zn
SOD) with diethyldithiocarbamic acid (DETCA, 3 mM), which almost abolished tissue
SOD activity. Carboxy-PTIO (0.1 - 0.5 mM) inhibited NO-mediated relaxations but
had no effect on responses to nitrergic stimulation, which were not changed by
treatment with ascorbate oxidase (2 u ml(-1)). Relaxations to NO were reduced,
but not abolished, by ODQ (10 microM), while nitrergic responses were completely
blocked. The thiol modulators, ethacrynic acid (0.1 mM), diamide (1.5 mM), or
5,5'-dithio-bis (2-nitrobenzoic acid) (DTNB, 0. 5 mM), and subsequent treatment
with dithiothreitol (DTT, 2 mM) had no effect on responses to nitrergic
stimulation or NO. In contrast, N-ethylmaleimide (NEM, 0.2 mM) markedly inhibited
both relaxations. L-cysteine (L-cys, 0.1 mM) had no effect on responses to NO,
while it inhibited those to nitrergic stimulation, in a Cu/Zn SOD-independent
manner. Our results do not support the view that the urethral nitrergic
transmitter is free NO, and the possibility that another compound is acting as
mediator still remains open. British Journal of Pharmacology (2000) 129, 53 - 62
PMID- 10694204
TI - Vascular endothelial growth factor attenuates trauma-induced injury in rats.
AB - Endothelial dysfunction and loss of nitric oxide (NO) is an integral part of the
initiation and maintenance of the inflammatory process such as that occurring in
traumatic shock, and is considered responsible for much of the trauma induced
microvascular injury. We investigated the effects of a vascular endothelial
growth factor (VEGF) in a rat model of traumatic shock. Pentobarbital
anaesthetized rats subjected to Noble-Collip drum trauma developed a shock state
characterized by marked hypotension and a 93% mortality rate with a mean survival
time of 108+/-10 min in 14 rats. Accompanying these effects was a significant
degree of endothelial dysfunction and a markedly elevated intestinal
myeloperoxidase (MPO) activity. Treatment with 125 microg kg(-1) VEGF
administered intravenously 18 h pre-trauma, increased survival rate to 67%
(P<0.01), and prolonged survival time to 252+/-24 min in 12 rats (P<0.01). VEGF
also significantly preserved the endothelium-dependent relaxation to ACh
indicating a preservation of endothelium-derived NO. Our results indicate that
endothelial dysfunction with its accompanying loss of NO plays an important role
in tissue injury associated with trauma, and that preservation of NO is
beneficial in traumatic shock. The mechanisms of the protective effect of VEGF in
trauma involves preservation of eNOS function and diminished neutrophil
accumulation resulting in reduced neutrophil-mediated tissue injury. British
Journal of Pharmacology (2000) 129, 71 - 76
PMID- 10694203
TI - Modulation of airway smooth muscle tone by protease activated receptor-1,-2,-3
and -4 in trachea isolated from influenza A virus-infected mice.
AB - Relaxant and contractile effects of the tethered ligand domain sequences of
murine PAR-1, PAR-2, PAR-3 and PAR-4, and of the proteases thrombin and trypsin
were examined in mouse isolated tracheal preparations. The epithelium- and cyclo
oxygenase-dependence of these effects and the potential modulatory effects of
respiratory tract viral infection were also investigated. In carbachol-contracted
preparations, trypsin, thrombin, and the tethered ligand domain sequences of
murine PAR-1 (SFFLRN-NH(2)), PAR-2 (SLIGRL-NH(2)) and PAR-4 (GYPGKF-NH(2)), but
not PAR-3 (SFNGGP-NH(2)), induced transient, relaxant responses that were
abolished by the cyclo-oxygenase inhibitor indomethacin. Repeated administration
of SFFLRN-NH(2), SLIGRL-NH(2) or GYPGKF-NH(2) (30 microM) was associated with
markedly diminished relaxation responses (homologous desensitization), although
there was no evidence of cross-desensitization between these peptides. The
tethered ligand domain sequences for PAR-1 and PAR-4 induced a rapid, transient
contractile response that preceded the relaxant response. Contractions were not
inhibited by indomethacin and were not induced by either thrombin or trypsin.
Influenza A virus infection did not significantly affect the responses induced by
either the proteases or peptides. Furthermore, epithelial disruption caused by
mechanical rubbing had no significant effect on responses to these PAR activators
in preparations from either virus- or sham-infected mice. In summary, the
proteases trypsin and thrombin, and peptide activators of PAR-1, PAR-2 and PAR-4
induced relaxant responses of mouse isolated tracheal smooth muscle preparations,
which were mediated by a prostanoid, probably PGE(2). Interestingly, PAR-mediated
relaxations were not significantly diminished following acute damage to the
epithelium caused by mechanical rubbing and/or the respiratory tract viral
pathogen, influenza A. British Journal of Pharmacology (2000) 129, 63 - 70.
PMID- 10694205
TI - Bradyzide, a potent non-peptide B(2) bradykinin receptor antagonist with long
lasting oral activity in animal models of inflammatory hyperalgesia.
AB - Bradyzide is from a novel class of rodent-selective non-peptide B(2) bradykinin
antagonists (1-(2-Nitrophenyl)thiosemicarbazides). Bradyzide has high affinity
for the rodent B(2) receptor, displacing [(3)H]-bradykinin binding in NG108-15
cells and in Cos-7 cells expressing the rat receptor with K(I) values of 0.51+/
0.18 nM (n=3) and 0.89+/-0.27 nM (n=3), respectively. Bradyzide is a competitive
antagonist, inhibiting B(2) receptor-induced (45)Ca efflux from NG108-15 cells
with a pK(B) of 8.0+/-0.16 (n=5) and a Schild slope of 1.05. In the rat spinal
cord and tail preparation, bradyzide inhibits bradykinin-induced ventral root
depolarizations (IC(50) value; 1.6+/-0.05 nM (n=3)). Bradyzide is much less
potent at the human than at the rodent B(2) receptor, displacing [(3)H]
bradykinin binding in human fibroblasts and in Cos-7 cells expressing the human
B(2) receptor with K(I) values of 393+/-90 nM (n=3) and 772+/-144 nM (n=3),
respectively. Bradyzide inhibits bradykinin-induced [(3)H]-inositol trisphosphate
(IP(3)) formation with IC(50) values of 11.6+/-1.4 nM (n=3) at the rat and 2.4+/
0.3 microM (n=3) at the human receptor. Bradyzide does not interact with a range
of other receptors, including human and rat B(1) bradykinin receptors. Bradyzide
is orally available and blocks bradykinin-induced hypotension and plasma
extravasation. Bradyzide shows long-lasting oral activity in rodent models of
inflammatory hyperalgesia, reversing Freund's complete adjuvant (FCA)-induced
mechanical hyperalgesia in the rat knee joint (ED(50), 0.84 micromol kg(-1);
duration of action >4 h). It is equipotent with morphine and diclofenac, and 1000
times more potent than paracetamol, its maximal effect exceeding that of the non
steroidal anti-inflammatory drugs (NSAIDs). Bradyzide does not exhibit tolerance
when administered over 6 days. In summary, bradyzide is a potent, orally active,
antagonist of the B(2) bradykinin receptor, with selectivity for the rodent over
the human receptor. British Journal of Pharmacology (2000) 129, 77 - 86
PMID- 10694206
TI - Sustained ethanol inhibition of native AMPA receptors on medial septum/diagonal
band (MS/DB) neurons.
AB - The direct impact of ethanol on native, non-NMDA glutamate receptors was examined
in acutely isolated MS/DB neurons from rat. The impact of ethanol functional
tolerance and physical dependence on non-NMDA receptor function was also
determined. Non-NMDA receptors were defined pharmacologically as predominantly
the AMPA subtype, because both AMPA- or kainate-activated currents were blocked
by GYKI 52466, a selective AMPA receptor antagonist. The relative magnitude of
potentiation of AMPA-activated currents by 10 or 100 microM cyclothiazide was
consistent with recombinant AMPA flop-subtype receptors. Finally, the selective
kainate receptor agonist, SYM 8021, induced little current in MS/DB neurons. AMPA
receptor currents when activated by kainate were sensitive to ethanol, showing
inhibition of approximately 5 - 50% when 10 - 300 mM ethanol and kainate were
briefly co-applied (3 s). Ethanol (100 mM) also inhibited both the initial
transient peak and sustained currents activated by AMPA. Inhibition was sustained
during continuous ethanol superfusions of 5 min, suggesting a lack of acute
tolerance to ethanol-induced AMPA receptor blockade. Rapid application of 3 -
3000 microM kainate activated concentration-dependent currents in MS/DB neurons
from Control and Ethanol Dependent animals that were not significantly different.
Also, direct ethanol inhibition (300 mM) of kainate-activated currents was not
reduced by ethanol dependence, suggesting a lack of functional tolerance. These
results suggest that native AMPA receptors on MS/DB neurons are inhibited by
pharmacologically-relevant concentrations of ethanol. However, these receptors,
unlike NMDA receptors, do not undergo adaptation with sustained ethanol exposure
sufficient to induce physical dependence. British Journal of Pharmacology (2000)
129, 87 - 94
PMID- 10694207
TI - The metabolism of clomethiazole in gerbils and the neuroprotective and sedative
activity of the metabolites.
AB - A single dose of clomethiazole (600 micromol kg(-1) i.p.) has previously been
shown to be neuroprotective in the gerbil model of global ischaemia. In gerbils,
clomethiazole (600 micromol kg(-1)) injection produced a rapid appearance (peak
within 5 min) of drug in plasma and brain and similar clearance (plasma t(1/2):
40 min) from both tissues. The peak brain concentration (226+/-56 nmol g(-1)) was
40% higher than plasma. One major metabolite, 5-(1-hydroxyethyl-2-chloro)-4
methylthiazole (NLA-715) and two minor metabolites 5-(1-hydroxyethyl)-4
methylthiazole (NLA-272) and 5-acetyl-4-methylthiazole (NLA-511) were detected in
plasma and brain. Evidence suggested that clomethiazole is metabolized directly
to both NLA-715 and NLA-272. Injection of NLA-715, NLA-272 or NLA-511 (each at
600 micromol kg(-1)) produced brain concentrations respectively 2.2, 38 and 92
times greater than seen after clomethiazole (600 micromol kg(-1)). Clomethiazole
(600 micromol kg(-1)) injected 60 min after a 5 min bilateral carotid artery
occlusion in gerbils attenuated the ischaemia-induced degeneration of the
hippocampus by approximately 70%. The metabolites were not neuroprotective at
this dose. In mice, clomethiazole (600 micromol kg(-1)) produced peak plasma and
brain concentrations approximately 100% higher than in gerbils, drug
concentrations in several brain regions were similar but 35% higher than plasma.
Clomethiazole (ED(50): 180 micromol kg(-1)) and NLA-715 (ED(50): 240 micromol kg(
1)) inhibited spontaneous locomotor activity. The other metabolites were not
sedative (ED(50) >600 micromol kg(-1)). These data suggest that the
neuroprotective action of clomethiazole results from an action of the parent
compound and that NLA-715 contributes to the sedative activity of the drug.
British Journal of Pharmacology (2000) 129, 95 - 100
PMID- 10694208
TI - Lipophilization of somatostatin analog RC-160 with long chain fatty acid improves
its antiproliferative and antiangiogenic activity in vitro.
AB - The therapeutic potential of the somatostatin analogue RC-160 having
antiproliferative activity, is limited by its short serum half life. To overcome
this limitation, fatty acids namely butanoic acid and myristic acid were
conjugated to the N-terminal residue of RC-160. The lipophilized derivatives of
RC-160 were synthesized, purified by reverse phase HPLC and characterized by ES
mass spectroscopy. The antiproliferative activity of lipophilized derivatives of
RC-160 on the growth of MIA-PaCa2 (human pancreatic carcinoma), DU145 (human
prostate carcinoma), ECV304 (human umbilical chord endothelioma), as well as
their antiangiogenic activity was evaluated in vitro. The relative stability of
myristoyl-RC-160 towards degradation by proteases and serum was also determined.
Myristoyl-RC-160 exhibited significantly higher antiproliferative efficacy than
RC-160, on the above cell lines (P<0.01). Receptor binding assays, demonstrated
that the affinity of RC-160 towards somatostatin receptors remains unaltered by
myristoylation. Unlike RC-160, the myristoylated derivative was found to have
significantly greater resistance to protease and serum degradation (P<0.01).
Myristoyl-RC-160 exhibited significantly greater antiproliferative activity on
ECV304, than RC-160 (P<0.01). Myristoyl RC-160 could also inhibit capillary tube
formation more efficiently than RC-160 in a dose dependent manner, suggesting
that it possessed enhanced antiangiogenic activity in vitro (P<0.001).
Lipophilization of RC-160 with long chain fatty acids like myristic acid endows
it with improved antiproliferative and antiangiogenic activity, stability and
therapeutic index. British Journal of Pharmacology (2000) 109, 101 - 109
PMID- 10694209
TI - The peripheral antinociceptive effect induced by morphine is associated with ATP
sensitive K(+) channels.
AB - The effect of several K(+) channel blockers such as glibenclamide, tolbutamide,
charybdotoxin (ChTX), apamin, tetraethylammonium (TEA), 4-aminopyridine (4-AP)
and cesium on the peripheral antinociceptive effect of morphine was evaluated by
the paw pressure test in Wistar rats. The intraplantar administration of a
carrageenan suspension (250 microg) resulted in an acute inflammatory response
and a decreased threshold to noxious pressure. Morphine administered locally into
the paw (25, 50, 100 and 200 microg) elicited a dose-dependent antinociceptive
effect which was demonstrated to be mediated by a peripheral site up to the 100
microg dose. The selective blockers of ATP-sensitive K(+) channels glibenclamide
(20, 40 and 80 microg paw(-1)) and tolbutamide (40, 80 and 160 microg paw(-1))
antagonized the peripheral antinociception induced by morphine (100 microg paw(
1)). This effect was unaffected by ChTX (0. 5, 1.0 and 2.0 microg paw(-1)), a
large conductance Ca(2+)-activated K(+) channel blocker, or by apamin (2.5, 5.0
and 10.0 microg paw(-1)), a selective blocker of a small conductance Ca(2+)
activated K(+) channel. Intraplantar administration of the non-specific K(+)
channel blockers TEA (160, 320 and 640 microg), 4-AP (10, 50 and 100 microg) and
cesium (125, 250 and 500 microg) also did not modify the peripheral
antinociceptive effect of morphine. These results suggest that the peripheral
antinociceptive effect of morphine may result from activation of ATP-sensitive
K(+) channels, which may cause a hyperpolarization of peripheral terminals of
primary afferents, leading to a decrease in action potential generation. In
contrast, large conductance Ca(2+)-activated K(+) channels, small conductance
Ca(2+)-activated K(+) channels as well as voltage-dependent K(+) channels appear
not to be involved in this transduction pathway. British Journal of Pharmacology
(2000) 129, 110 - 114
PMID- 10694211
TI - Effects of diadenosine polyphosphates (Ap(n)As) and adenosine polyphospho
guanosines (Ap(n)Gs) on rat mesenteric artery P2X receptor ion channels.
AB - Diadenosine polyphosphates (Ap(n)As, n=3 - 7) and adenosine polyphospho
guanosines (Ap(n)Gs, n=3 - 6) are naturally occurring vasoconstrictor substances
found in platelets. These vasoconstrictor actions are thought to be mediated
through the activation of P2X receptors for ATP. The effects of Ap(n)As and
Ap(n)Gs at P2X receptors on rat mesenteric arteries were determined in
contraction studies and using the patch clamp technique on acutely dissociated
artery smooth muscle cells. P2X(1) receptor immunoreactivity was detected in the
smooth muscle layer of artery rings. The sensitivity to alpha,beta-methylene ATP
and desensitizing nature of rat mesenteric artery P2X receptors correspond
closely to those of recombinant P2X(1) receptors. Ap(4)A, Ap(5)A and Ap(6)A
evoked concentration dependent P2X receptor inward currents which desensitized
during the application of higher concentrations of agonist. The agonist order of
potency was Ap(5)A> or = Ap(6)A> or = Ap(4)A >> Ap(3)A. Ap(2)A and Ap(7)A were
ineffective. Similar results were obtained in contraction studies except for
Ap(7)A which evoked a substantial contraction. Ap(n)Gs (n=2 - 6)(30 microM)
evoked P2X receptor inward currents in mesenteric artery smooth muscle cells.
Ap(n)Gs (n=4 - 6) were less effective than the corresponding Ap(n)A. This study
shows that at physiologically relevant concentrations Ap(n)As and Ap(n)Gs can
mediate contraction of rat mesenteric arteries through the activation of P2X(1)
like receptors. However the activity of the longer chain polyphosphates (n=6 - 7)
may be overestimated in whole tissue studies due to metabolic breakdown to yield
the P2X receptor agonists ATP and adenosine tetraphosphate. British Journal of
Pharmacology (2000) 129, 124 - 130
PMID- 10694210
TI - Functional neuroimaging of cognition impaired by a classical antihistamine, d
chlorpheniramine.
AB - Antihistamine induced cognitive decline was evaluated using positron emission
tomography (PET) measurement of histamine H1 receptor (H1R) occupancy and
regional cerebral blood flow (rCBF). Cognitive performance in attention-demanding
task deteriorated dose-dependently and the effects were statistically significant
after the treatment of 2 mg of d-chlorpheniramine. There was no significant
change in subjective sleepiness in the same dose. The regional blockade of H1R
was observed mainly in the frontal, temporal and anterior cingulate cortices, and
the intravenous administration of d-chlorpheniramine as a therapeutic dose (2 mg)
blocked over 60% of H1R in the frontal cortices. The results from activation
study using visual discrimination tasks demonstrated that enhanced activity in
the right prefrontal and anterior cingulate cortices as well as a decreased
activity in the left temporal and frontal cortices and midbrain after the
treatment of d-chlorpheniramine. There were no changes in global CBF for the
subjects treated with 2 mg d-chlorpheniramine (pre; 44.8+/-3.3 ml dl(-1) min(-1)
vs post; 44.4+/-4.7 ml dl(-1) min(-1)). The results indicated that the attention
system of human brain could be altered by therapeutic doses of H1R antagonists.
These findings provide the information as to the potential risk of antihistamines
in our daily activities. British Journal of Pharmacology (2000) 129, 115 - 123
PMID- 10694212
TI - Pharmacologic characterization of the oxytocin receptor in human uterine smooth
muscle cells.
AB - [(3)H]-oxytocin was used to characterize the oxytocin receptor found in human
uterine smooth muscle cells (USMC). Specific binding of [(3)H]-oxytocin to USMC
plasma membranes was dependent upon time, temperature and membrane protein
concentration. Scatchard plot analysis of equilibrium binding data revealed the
existence of a single class of high-affinity binding sites with an apparent
equilibrium dissociation constant (K(d)) of 0.76 nM and a maximum receptor
density (B(max)) of 153 fmol mg(-1) protein. The Hill coefficient (n(H)) did not
differ significantly from unity, suggesting binding to homogenous, non
interacting receptor populations. Competitive inhibition of [(3)H]-oxytocin
binding showed that oxytocin and vasopressin (AVP) receptor agonists and
antagonists displaced [(3)H]-oxytocin in a concentration-dependent manner. The
order of potencies for peptide agonists and antagonists was: oxytocin>[Asu(1,6)]
oxytocin>AVP= atosiban>d(CH(2))(5)Tyr(Me)AVP>[Thr(4),Gly(7)]-oxytocin>dDAVP, and
for nonpeptide antagonists was: L-371257>YM087>SR 49059>OPC-21268>SR 121463A>OPC
31260. Oxytocin significantly induced concentration-dependent increase in
intracellular Ca(2+) concentration ([Ca(2+)](i)) and hyperplasia in USMC. The
oxytocin receptor antagonists, atosiban and L-371257, potently and concentration
dependently inhibited oxytocin-induced [Ca(2+)](i) increase and hyperplasia. In
contrast, the V(1A) receptor selective antagonist, SR 49059, and the V(2)
receptor selective antagonist, SR 121463A, did not potently inhibit oxytocin
induced [Ca(2+)](i) increase and hyperplasia. The potency order of antagonists in
inhibiting oxytocin-induced [Ca(2+)](i) increase and hyperplasia was similar to
that observed in radioligand binding assays. In conclusion, these data provide
evidence that the high-affinity [(3)H]-oxytocin binding site found in human USMC
is a functional oxytocin receptor coupled to [Ca(2+)](i) increase and cell
growth. Thus human USMC may prove to be a valuable tool in further investigation
of the physiologic and pathophysiologic roles of oxytocin in the uterus. British
Journal of Pharmacology (2000) 129, 131 - 139
PMID- 10694213
TI - Involvement of cyclic AMP - PKA pathway in VIP-induced, charybdotoxin-sensitive
relaxation of longitudinal muscle of the distal colon of Wistar-ST rats.
AB - The intracellular mechanism of vasoactive intestinal peptide (VIP)-induced,
charybdotoxin (ChTx)-sensitive relaxation of longitudinal muscle of the distal
colon of Wistar-ST rats was studied. A single pulse or 100 pulses at 10 Hz of
electrical field stimulation (EFS) induced rapid transient relaxation or that
with a subsequent contraction of the longitudinal muscle in the presence of
atropine and guanethidine, respectively. Rp-8 bromo cAMPS, an inhibitor of cyclic
AMP dependent protein kinase (PKA), at 30 microM inhibited the relaxations
induced by EFS with a single or 100 pulses maximally by about 80 or 60%,
respectively. It also inhibited VIP (300 nM)-induced relaxation by 82%. VIP (100
nM - 1 microM) increased the cyclic AMP content of longitudinal muscle myenteric
plexus preparations obtained from the distal colon. ChTx at 100 nM almost
completely inhibited 8 bromo cyclic AMP-induced relaxation of the distal
segments. EFS with two or three pulses at 10 Hz induced inhibitory junction
potentials consisting of two phases, rapid and subsequent slow hyperpolarization
in the membrane potential of longitudinal smooth muscle cells. Rp-cAMPS, another
inhibitor of PKA, inhibited the delayed slow hyperpolarization. It also inhibited
the exogenously added VIP-induced hyperpolarization of the cell membrane. Thus,
the present study suggests that activation of PKA via activation of VIP receptors
is associated with activation of ChTx-sensitive K(+) channels in relaxation of
longitudinal muscle of the distal colon of Wistar-ST rats. British Journal of
Pharmacology (2000) 129, 140 - 146
PMID- 10694214
TI - Effects of nicotine and chlorisondamine on cerebral glucose utilization in
immobilized and freely-moving rats.
AB - Chlorisondamine blocks central nicotinic receptors for many weeks via an unknown
mechanism. Intracerebroventricular administration of [(3)H]-chlorisondamine in
rats results in an anatomically restricted and persistent intracellular
accumulation of radioactivity. The initial aim of the present study was to test
whether nicotinic receptor antagonism by chlorisondamine is also anatomically
restricted. Male adult rats were pretreated several times with nicotine to avoid
the disruptive effects of the drug seen in drug-naive animals. They then received
chlorisondamine (10 microg i. c.v.) or saline, and local cerebral glucose
utilization (LCGU) was measured 4 weeks later after acute nicotine (0.4 mg kg(-1)
s.c.) or saline administration. During testing, rats were partially immobilized.
Nicotine significantly increased LCGU in the anteroventral thalamus and in
superior colliculus. Chlorisondamine completely blocked the first of these
effects. Chlorisondamine significantly reduced LCGU in the lateral habenula,
substantia nigra pars compacta, ventral tegmental area, and cerebellar granular
layer. The second experiment was of similar design, but the rats were not pre
exposed to nicotine, and were tested whilst freely-moving. Acute nicotine
significantly increased LCGU in anteroventral thalamus, superior colliculus,
medial habenula and dorsal lateral geniculate. Overall, however, nicotine
significantly decreased LCGU. Most or all of the central effects of nicotine on
LCGU were reversed by chlorisondamine given 4 weeks beforehand. These findings
suggest that chlorisondamine blocks nicotinic effects widely within the brain.
They also indicate that in freely-moving rats, nicotine can reduce or stimulate
cerebral glucose utilization, depending on the brain area. British Journal of
Pharmacology (2000) 129, 147 - 155
PMID- 10694215
TI - Biphasic effects of NMDA on the motility of the rat portal vein.
AB - The effect of NMDA on the motility of the rat portal vein was studied in an
isolated preparation. NMDA induced a concentration-dependent (10(-7) - 10(-4) M)
increase of the contraction frequency (maximum increase, 148+/-6% of control at
NMDA 10(-4) M). The NMDA-induced excitatory response was prevented by the
competitive NMDA receptor antagonists (+/-)-2-Amino-5-phosphonopentanoic acid (AP
5, 5x10(-4) M) or (RS)-3-(2-carboxypiperazine-4-yl) propyl-1-phosphonic acid
(CPP, 10(-4) M). Tetrodotoxin (TTX, 10(-6) M) or atropine (10(-4) M) abolished
the NMDA-induced increase of the portal vein motility and reversed the excitatory
effect to a concentration-dependent inhibition (maximum inhibition, 52+/-8 and
29+/-7% of controls, respectively, at NMDA 10(-3) M). Removal of the endothelium
abolished the NMDA-induced inhibitory response. Sodium nitroprusside
concentration-dependently (10(-7) - 10(-5) M) inhibited the portal vein motility,
while L-N(G)-nitro-arginine methyl ester (L-NAME, 10(-4) M) reversed the
inhibitory effect of NMDA (in the presence of TTX), restoring the portal vein
spontaneous activity to control values. These results show that NMDA modulates
the portal vein motility in a biphasic manner: via indirect activation, through
prejunctional NMDA receptors presumably located on intrinsic excitatory neuronal
afferences, or via direct inhibition, through endothelial NMDA receptors
activating the nitric oxide pathway. Overall these findings support the
hypothesis of the existence of a peripheral glutamatergic innervation modulating
the contractile activity of the rat portal vein. British Journal of Pharmacology
(2000) 129, 156 - 162
PMID- 10694216
TI - Effect of 18beta-glycyrrhetinic acid on electromechanical coupling in the guinea
pig renal pelvis and ureter.
AB - We have tested the effect of the gap junction inhibitor, 18beta-glycyrrhetinic
acid (18betaGA) on electromechanical coupling in the guinea-pig renal pelvis and
ureter by the sucrose gap technique. In the ureter 18betaGA (3 - 30 microM)
produced a concentration-dependent inhibition of the spike component of the
action potential (AP) and reduced contraction evoked by electrical stimulation.
Neurokinin A (NKA) produced a slow depolarization with superimposed APs and
phasic contractions of the ureter. 18betaGA (30 microM) markedly inhibited the
depolarization and APs evoked by NKA. However the contractile response was more
sustained in the presence than in the absence of 18betaGA. At 100 microM,
18betaGA inhibited the mechanical responses to NKA. KCl (80 mM) produced APs and
phasic contractions followed by sustained depolarization and tonic contraction.
At 30 microM 18betaGA markedly inhibited the KCl-evoked APs and phasic
contractions without affecting the sustained responses. At 100 microM 18betaGA
inhibited the tonic contraction to KCl. In the renal pelvis 18betaGA (30 microM)
inhibited the amplitude of pacemaker potentials and accompanying contractions and
induced the appearance of low-amplitude APs not associated with contraction. We
conclude that, up to 30 microM, the action of 18betaGA is consistent with an
inhibition of cell-to-cell electrical coupling via gap junctions. The single-unit
character of smooth muscles in the guinea-pig upper urinary tract is partly
converted to a multi-unit pattern. At high concentrations 18betaGA possesses non
specific effects which limit its usefulness as a tool for studying the role of
gap junctions in smooth muscles. British Journal of Pharmacology (2000) 129, 163
169
PMID- 10694217
TI - Contraction to big endothelin-1, big endothelin-2 and big endothelin-3, and
endothelin-converting enzyme inhibition in human isolated bronchi.
AB - All three endothelin precursor peptides, i.e. big endothelin-1 (big ET-1), big
endothelin-2 (big ET-2) and big endothelin-3 (big ET-3), produced contractile
responses in human isolated bronchi, demonstrating the presence of functional
endothelin-converting enzyme (ECE) in this tissue. The maximal contractile
responses were equal to 108.4+/-8.0% (0.1 microM big ET-1; n=4), 85.2+/-11.8%
(0.1 microM big ET-2; n=7) and 43.0+/-7.2% (0.1 microM big ET-3; n=5) of the
reference response to acetylcholine (1 mM). The response to big ET-1 (0.1
microM), but not endothelin-1 (ET-1, 0.1 microM), was diminished after overnight
storage of the tissue at 4 degrees C, demonstrating instability of the enzyme.
The responses to all three big-endothelins were significantly inhibited, by the
ECE inhibitors CGS 26393 and CGS 26303, in a concentration-related manner. The
responses to the mature peptides ET-1, endothelin-2 (ET-2), and endothelin-3 (ET
3) were unaffected by CGS 26393 and CGS 26303. Phosphoramidon (10 microM) also
produced an inhibition of the response to big ET-1 that was equivalent to that
produced by CGS 26393 (10 microM). Combination of CGS 26393 (10 microM) and
phosphoramidon (10 microM) did not produce an additive inhibition. These results
demonstrate the presence of functional ECE for all three big endothelins in human
bronchus and inhibition of the enzyme by newly developed orally active ECE
inhibitors, as well as phosphoramidon. British Journal of Pharmacology (2000)
129, 170 - 176
PMID- 10694218
TI - Evidence that activation of central 5-HT(2B) receptors causes renal
sympathoexcitation in anaesthetized rats.
AB - The effects of injections i.c.v. of alpha-methyl-5-(2-thienylmethoxy)-1H-indole-3
ethanamine (BW723C86; 0.02 - 2 micromol kg(-1)), a 5-HT(2B) receptor agonist, on
renal sympathetic and phrenic nerve activity, mean arterial blood pressure and
heart rate were investigated in alpha-chloralose anaesthetized rats pretreated
with a peripherally acting 5-HT(2) receptor antagonist. BW723C86 i.c.v. caused a
dose-related increase in renal nerve activity reaching a maximum of 67+/-6%,
which at the highest dose was associated with a small and maintained fall in mean
arterial blood pressure of 7+/-3 mmHg. These changes were not associated with any
significant changes in heart rate or phrenic nerve activity. BW723C86-evoked
increases in renal nerve activity and hypotension were attenuated by pretreatment
(i.c.v.) with SB204741 (300 nmol kg(-1); a 5-HT(2B) receptor antagonist) but not
by the same dose (i.c.v.) of ketanserin (a 5-HT(2A) receptor antagonist) or
RS102221 (a 5-HT(2C) receptor antagonist). None of these antagonists alone had
any effect on the variables being measured. It is concluded that central 5-HT(2B)
receptors may play a selective role in the control of sympathetic supply to the
kidney, which could be important in the central mechanisms involved in blood
volume regulation. British Journal of Pharmacology (2000) 129, 177 - 183
PMID- 10694219
TI - Nitric oxide, prostanoid and non-NO, non-prostanoid involvement in acetylcholine
relaxation of isolated human small arteries.
AB - The main purpose of the study was to clarify to which extent nitric oxide (NO)
contributes to acetylcholine (ACh) induced relaxation of human subcutaneous small
arteries. Arterial segments were mounted in myographs for recording of isometric
tension, NO concentration and smooth muscle membrane potential. In noradrenaline
contracted arteries, ACh induced endothelium-dependent relaxations. The NO
synthase inhibitor, N(G)-nitro-L-arginine (L-NOARG) had a small significant
effect on the concentration-response curves for ACh, and in the presence of L
NOARG, indomethacin only caused a small additional rightward shift in the ACh
relaxation. The NO scavenger, oxyhaemoglobin attenuated relaxations for ACh and
for the NO donor S-nitroso-N-acetylpenicillamine (SNAP). Inhibition of guanylyl
cyclase with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ), and inhibition
of protein kinase G with beta-phenyl-1, N2-etheno-8-bromoguanosine- 3', 5'-
cyclic monophosphorothioate, Rp-isomer, slightly attenuated ACh relaxation, but
abolished SNAP induced relaxation. ACh induced relaxation without increases in
the free NO concentration. In contrast, for equivalent relaxation, SNAP increased
the NO concentration 32+/-8 nM. ACh hyperpolarized the arterial smooth muscle
cells with 11.4+/-1.3 mV and 10.5+/-1.3 mV in the absence and presence of L
NOARG, respectively. SNAP only elicited a hyperpolarization of 1.6+/-0.9 mV. In
the presence of indomethacin and L-NOARG, ACh relaxation was almost unaffected by
lipoxygenase inhibition with nordihydroguaiaretic acid, or cytochrome P450
inhibition with 17-octadecynoic acid or econazole. ACh relaxation was strongly
reduced by the combination of charybdotoxin and apamin, but small increments in
the extracellular potassium concentration induced no relaxations. The study
demonstrates that the NO/L-arginine pathway is present in human subcutaneous
small arteries and to a limited extent is involved in ACh induced relaxation. The
study also suggests a small contribution of arachidonic acid metabolites.
However, ACh relaxation is mainly dependent on a non-NO, non-prostanoid
endothelium dependent hyperpolarization. British Journal of Pharmacology (2000)
129, 184 - 192
PMID- 10694220
TI - Role of tachykinin NK2 receptors in normal and altered rectal sensitivity in
rats.
AB - Irritable bowel syndrome is characterized by visceral hyperalgesia commonly
associated with stress and inflammatory processes. We investigated the role of
tachykinin NK2 receptors in the ability of trinitrobenzenesulphonic acid (TNBS)
and stress to enhance the sensitivity of the rat rectum to distension using a
selective tachykinin NK2 receptor antagonist (MEN 11420). Rats were fitted with
electrodes implanted in the striated muscles of the abdomen. Rectal distension
(RD) was performed with a balloon inflated by steps of 0.4 ml from 0 to 1.6 ml.
Five groups were submitted to RD performed 3 days before and after intrarectal
instillation of TNBS. Fifteen minutes before RD, rats were treated with saline or
MEN 11420 (5 - 100 microg kg(-1) i.v.). Two other groups, submitted to 2 h
restraint or sham stress sessions were randomly treated i.v. with saline or MEN
11420 (10 - 200 microg kg(-1)) prior to RD applied 20 min later. The basal
response to RD was characterized by a significant increase in the number of
abdominal contractions. This response occurred with a threshold volume of 0.8 ml
and was dose-dependently reduced by MEN 11420 (5 - 100 microg kg(-1) i.v.).
Rectal inflammation lowered the volume of distension producing abdominal
contractions to 0.4 ml (allodynia). This effect was either reduced or suppressed
by MEN 11420. A similar allodynia was observed after a stress session and this
effect was reduced (49%) or suppressed by MEN 11420 at 200 and 100 microg kg(-1),
respectively. Tachykinin NK2 receptors are involved in rectal hypersensitivity
associated with inflammation and stress. British Journal of Pharmacology (2000)
129, 193 - 199
PMID- 10694221
TI - Differential effects of the tricyclic antidepressant amoxapine on glycine uptake
mediated by the recombinant GLYT1 and GLYT2 glycine transporters.
AB - We examined the effects of nine different tricyclic antidepressant drugs on the
glycine uptake mediated by the glycine transporter 1b (GLYT1b) and glycine
transporter 2a (GLYT2a) stably expressed in human embryonic kidney 293 cells.
Desipramine, imipramine, clomipramine, nomifensine and mianserin had no effect on
the activity of the glycine transporters. Doxepin, amitriptyline and
nortriptyline inhibited the two transporter subtypes to a similar extent.
Amoxapine displayed a selective inhibition of GLYT2a behaving as a 10 fold more
efficient inhibitor of this isoform than of GLYT1b. Kinetic analysis of the
initial rates of glycine uptake by GLYT2a as a function of either glycine,
chloride or sodium concentration, in the absence and presence of amoxapine
indicated that amoxapine behaved as a competitive inhibitor of both glycine and
chloride and a mixed-type inhibitor with respect to sodium. A kinetic model was
developed which explains adequately these data, and gives information about the
order of binding of sodium and chloride ions to GLYT2a. Our results may
contribute to the development of the glycine transporter pharmacology.
Additionally, the inhibition of the glycine uptake by GLYT2 is suggested to have
some role in the sedative and psychomotor side effects of amoxapine. British
Journal of Pharmacology (2000) 129, 200 - 206
PMID- 10694222
TI - Nitric oxide synthase expression, enzyme activity and NO production during
angiogenesis in the chick chorioallantoic membrane.
AB - In order to elucidate further the role of nitric oxide (NO) as an endogenous
antiangiogenic mediator, mRNA expression of inducible nitric oxide synthase
(iNOS), enzyme activity and production of NO were determined in the chick
chorioallantoic membrane (CAM), an in vivo model of angiogenesis. In this model,
maximum angiogenesis is reached between days 9 - 12 of chick embryo development.
After that period, vascular density remains constant. Inducible NO synthase
(iNOS) mRNA expression, determined by reverse transcriptase polymerase chain
reaction (RT - PCR), increased from the 8th day reaching a maximum (70% increase)
at days 10 - 11. NO synthase activity, determined as citrulline formation in the
presence of calcium, also increased from day 8 reaching a maximum around day 10
(100% increase). Similar results were obtained in the absence of calcium
suggesting that the NOS determined was the inducible form. Nitric oxide
production, determined as nitrites, increased from day 8 reaching a maximum
around day 10 (64% increase) and remaining stable at day 13. Finally, the
bacterial lipopolysaccharide LPS (which activates transcriptionally iNOS),
inhibited dose dependently angiogenesis in the CAM. These results in connection
with previous findings from this laboratory, showing that NO inhibits
angiogenesis in the CAM, suggest that increases in iNOS expression, enzyme
activity and NO production closely parallel the progression of angiogenesis in
the CAM, thus providing an endogenous brake to control this process. British
Journal of Pharmacology (2000) 129, 207 - 213
PMID- 10694225
TI - The endogenous lipid anandamide is a full agonist at the human vanilloid receptor
(hVR1).
AB - The endogenous cannabinoid anandamide was identified as an agonist for the
recombinant human VR1 (hVR1) by screening a large array of bioactive substances
using a FLIPR-based calcium assay. Further electrophysiological studies showed
that anandamide (10 or 100 microM) and capsaicin (1 microM) produced similar
inward currents in hVR1 transfected, but not in parental, HEK293 cells. These
currents were abolished by capsazepine (1 microM). In the FLIPR anandamide and
capsaicin were full agonists at hVR1, with pEC(50) values of 5. 94+/-0.06 (n=5)
and 7.13+/-0.11 (n=8) respectively. The response to anandamide was inhibited by
capsazepine (pK(B) of 7.40+/-0.02, n=6), but not by the cannabinoid receptor
antagonists AM630 or AM281. Furthermore, pretreatment with capsaicin desensitized
the anandamide-induced calcium response and vice versa. In conclusion, this study
has demonstrated for the first time that anandamide acts as a full agonist at the
human VR1.
PMID- 10694226
TI - Curcumin prevents adriamycin nephrotoxicity in rats.
AB - The present study investigated the effect of curcumin on adriamycin (ADR)
nephrosis in rats. The results indicate that ADR-induced kidney injury was
remarkably prevented by treatment with curcumin. Treatment with curcumin markedly
protected against ADR-induced proteinuria, albuminuria, hypoalbuminaemia and
hyperlipidaemia. Similarly, curcumin inhibited ADR-induced increase in urinary
excretion of N-acetyl-beta-D-glucosaminidase (a marker of renal tubular injury),
fibronectin and glycosaminoglycan and plasma cholesterol. Curcumin restored renal
function in ADR rats, as judged by the increase in GFR. The data also
demonstrated that curcumin protected against ADR-induced renal injury by
suppressing oxidative stress and increasing kidney glutathione content and
glutathione peroxidase activity. In like manner, curcumin abolished ADR
stimulated kidney microsomal and mitochondrial lipid peroxidation. These data
suggest that administration of curcumin is a promising approach in the treatment
of nephrosis caused by ADR.
PMID- 10694227
TI - A novel anionic conductance affects action potential duration in isolated rat
ventricular myocytes.
AB - Effects of extracellular anions were studied in electrophysiological experiments
on freshly isolated rat ventricular myocytes. Under current-clamp, action
potential duration (APD) was prolonged by reducing the extracellular Cl(-)
concentration and shortened by replacement of extracellular Cl(-) with I(-).
Under voltage-clamp, membrane potential steps or ramps evoked an anionic
background current (I(AB)) carried by either Cl(-), Br(-), I(-) or NO(3)(-).
Activation of I(AB) was Ca(2+)- and cyclic AMP-independent, and was unaffected by
cell shrinkage. I(AB) was insensitive to stilbene and fenamate anion transport
blockers at concentrations that inhibit Ca(2+)-, cyclic AMP- and swelling
activated Cl(-) currents in ventricular cells of other mammals. These results
suggest that I(AB) may be carried by a novel class of Cl(-) channel. Correlation
of anion substitution experiments on membrane current and action potentials
revealed that I(AB) could play a major role in controlling rat ventricular APD.
These findings have important implications for those studying cardiac Cl(-)
channels as potential targets for novel antiarrythmic agents.
PMID- 10694228
TI - Enhanced nociception by exogenous and endogenous substance P given into the
spinal cord in mice lacking NR(2)A/epsilon(1), an NMDA receptor subunit.
AB - In capsaicin-pretreated mice, the nociceptive responses induced by intrathecally
(i.t.) administered substance P (SP) were enhanced by N-methyl-D-aspartate (NMDA)
type receptor antagonists, dizocilpine (MK801) and D-2-amino-5
phosphonopentanoate (D-AP5) in a dose-dependent manner. Similar enhancement of SP
induced nociception was also observed in mice lacking the NMDA-type glutamate
receptor NR2A/epsilon(1) subunit gene (GluRepsilon(1)(-/-) mice). On the other
hand, GluRepsilon(1)(-/-) mice showed a marked enhancement of the peripheral
nociceptive responses induced by intraplantar (i.pl.) injection of SP and
bradykinin (BK). As the nociceptive responses to SP and BK (i.pl.) were both
antagonized by CP-99994, an neurokinin(1) (NK(1)) antagonist (i.t.), these
results suggest that GluRepsilon(1) receptor may play an inhibitory role in the
downstream mechanisms of primary nociceptive SP neurones, possibly through
activation of unidentified inhibitory neurones.
PMID- 10694229
TI - Adenosine induces cyclic-AMP formation and inhibits endothelin-1
production/secretion in guinea-pig tracheal epithelial cells through A(2B)
adenosine receptors.
AB - 1. The adenosine receptor subtype mediating adenosine 3' : 5'-cyclic
monophosphate (cyclic AMP) formation and the effect of its activation on
endothelin-1 (ET-1) secretion were studied in primary cultures of tracheal
epithelial cells. 2. Adenosine analogues showed the following rank order of
potency (pD(2) value) and intrinsic activity on the generation of cyclic AMP by
tracheal epithelial cells: 5'-N-ethylcarboxyamidoadenosine (NECA,
A(1)/A(2A)/A(2B), pD(2): 5.44+/-0.16)>adenosine (ADO, non selective, pD(2):
4.99+/-0. 09; 71+/-9% of NECA response) >/=2-Cl-adenosine (2CADO, non selective,
pD(2): 4.72+/-0.14; 65+/-9% of NECA response)>>>CGS21680 (A(2A); inactive at up
to 100 microM). 3. Cyclic AMP formation stimulated by NECA in guinea-pig tracheal
epithelial cells was inhibited by adenosine receptor antagonist with the
following order of apparent affinity (pA(2) value): Xanthine amine congeners
(XAC, A(2A)/A(2B), 7.89+/-0.22)>CGS15943 (A(2A)/A(2B), 7.24+/-0. 26)>ZM241385
(A(2A), 6.69+/-0.14)>DPCPX (A(1), 6.51+/-0. 14)>3n-propylxanthine (weak A(2B),
4.30+/-0.10). This rank order of potency is typical for A(2B)-adenosine receptor.
4. Adenosine decreased basal and LPS-stimulated irET production in a
concentration-dependent manner. Moreover, NECA but not CGS21680 inhibited LPS
induced irET production. 5. The inhibitory effect of NECA on LPS-induced irET
production was reversed by XAC (pA(2)=8.84+/-0. 12) and DPCPX (pA(2)=8.10+/
0.22). 6. These results suggested that adenosine increased cyclic AMP formation
and inhibited irET production/secretion by guinea-pig tracheal epithelial cells
through the activation of a functional adenosine receptor that is most likely the
A(2B) subtype. This adenosine receptor may be involved in the regulation of the
level of ET-1 production/secretion by guinea-pig tracheal epithelial cells in
physiological as well as in pathophysiological conditions.
PMID- 10694230
TI - P-glycoprotein- and mrp2-mediated octreotide transport in renal proximal tubule.
AB - 1. Transepithelial transport of a fluorescent derivative of octreotide (NBD
octreotide) was studied in freshly isolated, functionally intact renal proximal
tubules from killifish (Fundulus heteroclitus). 2. Drug accumulation in the
tubular lumen was visualized by means of confocal microscopy and was measured by
image analysis. Secretion of NBD-octreotide into the tubular lumen was
demonstrated and exhibited the all characteristics of specific and energy
dependent transport. Steady state luminal fluorescence averaged about five times
cellular fluorescence and was reduced to cellular levels when metabolism was
inhibited by NaCN. 3. NBD-octreotide secretion was inhibited in a concentration
dependent manner by unlabelled octreotide, verapamil and leukotriene C(4)
(LTC(4)). Conversely, unlabelled octreotide reduced in a concentration dependent
manner the p-glycoprotein (Pgp)-mediated secretion of a fluorescent cyclosporin A
derivative (NBDL-CS) and the mrp2-mediated secretion of fluorescein methotrexate
(FL-MTX). 4. This inhibition was not due to impaired metabolism or toxicity since
octreotide had no influence on the active transport of fluorescein (FL), a
substrate for the classical renal organic anion transport system. 5. The data are
consistent with octreotide being transported across the brush border membrane of
proximal kidney tubules by both Pgp and mrp2.
PMID- 10694231
TI - Mechanisms of AVP-induced glucagon release in clonal alpha-cells in-R1-G9:
involvement of Ca(2+)-dependent and -independent pathways.
AB - 1. The mechanisms underlying AVP-induced increase in [Ca(2+)](i) and glucagon
release in clonal alpha-cells In-R1-G9 were investigated. 2. AVP increased
[Ca(2+)](i) and glucagon release in a concentration-dependent manner. After the
administration of AVP, glucagon was released within 30 s, quickly reached the
maximum within 2 min, and maintained a steady-state concentration for at least 15
min. 3. In Ca(2+)-containing medium, AVP increased [Ca(2+)](i) in a biphasic
pattern; a peak followed by a sustained plateau. In Ca(2+)-free medium, the
Ca(2+) response to AVP became monophasic with lower amplitude and no plateau.
Both the basal and AVP-induced glucagon releases were lower in the absence than
in the presence of extracellular Ca(2+). When [Ca(2+)](i) was stringently
deprived by BAPTA, a Ca(2+) chelator, AVP still significantly increased glucagon
release. 4. Pretreatment with thapsigargin, a microsomal Ca(2+) ATPase inhibitor,
abolished both the Ca(2+) peak and sustained plateau. 5.AVP increased
intracellular concentration of IP(3). 6. U-73122 (8 microM), a phospholipase C
inhibitor, abolished AVP-induced increases in [Ca(2+)](i), but only reduced AVP
induced glucagon release by 39%. 7. Pretreatment with nimodipine, an L-type
Ca(2+) channel blocker failed to alter AVP-induced glucagon release or increase
in [Ca(2+)](i). 8. The results suggest that AVP causes glucagon release through
both Ca(2+)-dependent and -independent pathways. For the Ca(2+)-dependent
pathway, the G(q) protein activates phospholipase C, which catalyzes the
formation of IP(3). IP(3) induces Ca(2+) release from the endoplasmic reticulum,
which, in turn, triggers Ca(2+) influx. Both Ca(2+) release and Ca(2+) influx may
contribute to AVP-induced glucagon release.
PMID- 10694232
TI - Voltage-dependent block of native AMPA receptor channels by dicationic compounds.
AB - 1. The kinetics of open channel block of GluR2-containing and GluR2-lacking AMPA
receptors (AMPAR) by dicationic compounds (IEM-1460, IEM-1754, and IEM-1925) have
been studied in rat hippocampal neurones using whole-cell patch clamp recording
and concentration-jump techniques. Neurones were isolated from hippocampal slices
by vibrodissociation. 2. The dicationic compounds were approximately 100 - 200
times more potent as blockers of GluR2-lacking AMPAR than as blockers of GluR2
containing AMPAR. The subunit specificity of channel block is determined by the
blocking rate constant of a dicationic compound, whereas differences in
unblocking rate constants account for differences in potency. 3.
Hyperpolarization may decrease the block produced by IEM-1460 and IEM-1754 block
due to the voltage-dependence of the unblocking rate constants for these
compounds. This suggests that dicationic compounds permeate the AMPAR channel at
negative membrane potentials. The effect was particularly apparent for GluR2
lacking AMPAR. These findings indicate that the presence of GluR2-subunit(s) in
AMPAR hinders the binding of the cationic compounds and their permeation through
the channel. 4. The most potent compound tested was IEM-1925. The presence of a
phenylcyclohexyl moiety instead of an adamantane moiety, as in IEM-1460 and
IEM1754, is probably responsible for the higher potency of IEM-1925. Dicationic
compounds are important not only as pharmacological tools, but also as templates
for the synthesis of new selective AMPAR blockers which may be potential
therapeutic agents.
PMID- 10694233
TI - ADP can induce aggregation of human platelets via both P2Y(1) and P(2T)
receptors.
AB - 1. In the present study we have investigated the roles of P2Y(1) and P(2T)
receptor subtypes in adenosine 5'-diphosphate (ADP)-induced aggregation of human
platelets in heparinized platelet rich plasma. 2. The response to ADP can be
characterized as the initial rate or the maximum or final extent of aggregation.
The response profile is determined by the concentration of ADP used, being
transient at lower and sustained at higher concentrations. 3. The P2Y(1) receptor
antagonist, adenosine-3'-phosphate-5'-phosphate (A3P5P) competitively antagonized
the initial rate of aggregation (pK(B) 5. 47) and transformed the response
profile to a slowly developing but sustained response. Both maximum and final
extents were also inhibited by A3P5P although not in a competitive manner (Schild
slope <1). 4. The P(2T) receptor antagonist, AR-C67085, competitively antagonized
the final extent of aggregation (pK(B) 8.54), transforming the response profile
to one of rapid, transient aggregation. Its effect on maximum extent (the most
widely used index of aggregation) was complex, and further supported the
involvement of both receptor subtypes in the aggregation response. 5. ADP-induced
aggregation is a complex phenomenon, the nature of which is determined by the
relative occupancy of the two receptor subtypes. While P2Y(1) receptor activation
causes a rapid and transient aggregation, the extent of sustained aggregation is
determined by the level of P(2T) receptor occupancy. Hence, detailed analysis of
the aggregation response is essential to correctly define the purinergic
pharmacology of the platelet and interpretation of results is critically
dependent on the response index chosen.
PMID- 10694234
TI - Stereoselective modulatory actions of oleamide on GABA(A) receptors and voltage
gated Na(+) channels in vitro: a putative endogenous ligand for depressant drug
sites in CNS.
AB - 1. cis-9,10-octadecenoamide ('oleamide') accumulates in CSF on sleep deprivation.
It induces sleep in animals (the trans form is inactive) but its cellular actions
are poorly characterized. We have used electrophysiology in cultures from
embryonic rat cortex and biochemical studies in mouse nerve preparations to
address these issues. 2. Twenty microM cis-oleamide (but not trans) reversibly
enhanced GABA(A) currents and depressed the frequency of spontaneous excitatory
and inhibitory synaptic activity in cultured networks. 3. cis-oleamide
stereoselectively blocked veratridine-induced (but not K(+)-induced)
depolarisation of mouse synaptoneurosomes (IC(50), 13. 9 microM). 4. The cis
isomer stereoselectively blocked veratridine-induced (but not K(+)-induced)
[(3)H]-GABA release from mouse synaptosomes (IC(50), 4.6 microM). 5. At 20 microM
cis-oleamide, but not trans, produced a marked inhibition of Na(+) channel
dependent rises in intrasynaptosomal Ca(2+). 6. The physiological significance of
these observations was examined by isolating Na(+) spikes in cultured pyramidal
neurones. Sixty-four microM cis-oleamide did not significantly alter the
amplitude, rate of rise or duration of unitary action potentials (1 Hz). 7. cis
Oleamide stereoselectively suppressed sustained repetitive firing (SRF) in these
cells with an EC(50) of 4.1 microM suggesting a frequency- or state-dependent
block of voltage-gated Na(+) channels. 8. Oleamide is a stereoselective modulator
of both postsynaptic GABA(A) receptors and presynaptic or somatic voltage-gated
Na(+) channels which are crucial for synaptic inhibition and conduction. The
modulatory actions are strikingly similar to those displayed by sedative or
anticonvulsant barbiturates and a variety of general anaesthetics. 9. Oleamide
may represent an endogenous modulator for drug receptors and an important
regulator of arousal.
PMID- 10694235
TI - Effects of P(1) and P2 receptor antagonists on beta, gamma-methyleneATP- and
CGS21680-induced cyclic AMP formation in NG108-15 cells.
AB - 1. We have previously shown that ATP increased cyclic AMP in NG108-15 cells,
which was inhibited by P(1) receptor antagonist methylxanthines. In the present
study, we examined the effects of P(1) and P2 receptor antagonists on cyclic AMP
formation induced by beta,gamma-methyleneATP (beta,gamma-MeATP) and CGS21680, an
A(2A) adenosine receptor agonist, in NG108-15 cells. 2. beta,gamma-MeATP and
CGS21680 increased intracellular cyclic AMP with EC(50) values of 8. 0+/-0.98
microM (n=4) and 42+/-7.5 nM (n=4), respectively. 3. Several P(1) receptor
antagonists inhibited both beta,gamma-MeATP- and CGS21680-induced cyclic AMP
increase with a similar rank order of potency; ZM241385>CGS15943>XAC>DPCPX.
However, the pK(i) values of these antagonists for beta,gamma-MeATP were larger
than those for CGS21680. 4. Alloxazine, a P(1) receptor antagonist, and several
P2 receptor antagonists (PPADS, iPPADS, reactive blue-2) inhibited beta, gamma
MeATP-induced response, while these antagonists little affected CGS21680-induced
one. Suramin was effective only for beta, gamma-MeATP-induced response at 1 mM.
5. 2-chloroadenosine (2CADO) and 2-chloroATP (2ClATP) increased cyclic AMP with
similar potencies. The effects of these agonists were both inhibited by ZM241385,
but only 2ClATP-induced response was inhibited by PPADS. 6. ATP- and beta, gamma
MeATP-induced responses were little affected by alpha, beta-methyleneADP, a 5'
nucleotidase inhibitor. 7. These results clearly demonstrate that ATP-stimulated
cyclic AMP formation can be distinguished from the A(2A) receptor agonist-induced
one by using the several P(1) and P2 receptor antagonists.
PMID- 10694236
TI - Different role of IL-4 in the onset of hapten-induced contact hypersensitivity in
BALB/c and C57BL/6 mice.
AB - 1. To study the role of interleukin (IL)-4 in the onset of contact
hypersensitivity (CH) in mice, the effect of IL-4 gene-depletion and anti-IL-4
monoclonal antibody treatment on dinitrofluorobenzene (DNFB)-induced CH was
examined. Simultaneously, to clarify the effect of background gene, DNFB-induced
CH in BALB/c and C57BL/6 mice was compared. 2. Five repeated topical applications
of DNFB to the ears of mice resulted in CH of the ears in terms of increases in
ear thickness and histopathological changes. The magnitude of ear thickness
increase in BALB/c mice was almost three times greater than that in C57BL/6 mice.
3. The CH in BALB/c mice was significantly suppressed by IL-4 gene-depletion and
anti-IL-4 monoclonal antibody treatment. In contrast, the symptoms of dermatitis
in C57BL/6 mice were slightly affected by the same treatment. These changes
corresponded well to the production of specific IgE antibody. 4. Total IgE
antibody production and the expression of productive Cepsilon mRNA were
dramatically suppressed by IL-4 gene-depletion and anti-IL-4 treatment in BALB/c
and C57BL/6 mice. Neither total IgG nor IgM levels in either strain of mice was
altered by depletion of IL-4. 5. The expression of IFN-gamma in the skin lesion
was dramatically suppressed by IL-4 gene-depletion in BALB/c mice, but not in
C57BL/6 mice. 6. These findings indicate that IL-4 plays an important role in the
onset of DNFB-induced CH in BALB/c mice, but not in C57BL/6 mice.
PMID- 10694237
TI - Lipopolysaccharide activates nuclear factor kappaB in rat intestine: role of
endogenous platelet-activating factor and tumour necrosis factor.
AB - 1. We examined the effect of lipopolysaccharide (LPS), a cell wall constituent of
Gram negative bacteria, on nuclear factor kappaB (NF-kappaB) activation in the
intestine and the roles of endogenous platelet-activating factor (PAF), tumour
necrosis factor-alpha (TNF) and neutrophils. We also compared the time course of
NF-kappaB activation in response to PAF and LPS. 2. Ileal nuclear extracts from
LPS (8 mg kg(-1), IV)-injected rats were assayed for NF-kappaB-DNA-binding
activity and identification of the subunits. Some rats were pretreated with
WEB2170 (a PAF receptor antagonist), anti-TNF antibody, or anti-neutrophil
antiserum. NF-kappaB p65 was localized by immunohistochemistry. An additional
group was challenged with PAF (2 microg kg(-1), IV) for comparison. 3. LPS
activates intestinal NF-kappaB, both as p50-p50 and p50-p65 dimers within 15 min,
and the effect peaks at 2 h. The effect is slower and more sustained than that of
PAF, which peaks at 30 min. Activated NF-kappaB was immunolocalized within
epithelial and lamina propria cells. LPS effect was reduced by 41, 37 and 44%,
respectively, in animals pretreated with WEB2170, anti-TNF antibody, or anti
neutrophil antiserum (P<0.05). 4. LPS activates intestinal NF-kappaB in vivo and
neutrophil activation is involved in its action. The LPS effect is mediated by
both endogenous PAF and TNF.
PMID- 10694238
TI - Differential actions of L-cysteine on responses to nitric oxide, nitroxyl anions
and EDRF in the rat aorta.
AB - 1. The effects of L-cysteine were tested in rat aortic rings on responses to
nitric oxide free radical (NO(*)), nitroxyl (NO(-)) derived from Angeli's salt
and endothelium-derived relaxing factor (EDRF) activated by acetylcholine, ATP
and the calcium ionophore A23187. Concentrations of 300 microM or less of L
cysteine had no effect on responses. 2. Relaxations produced by exogenous NO(*)
(0.25 - 2.5 microM) were markedly prolonged and relaxations produced by sodium
nitroprusside (0.001 - 0.3 microM) were enhanced by 1 and 3 mM L-cysteine. The
enhancements by L-cysteine of responses to NO(*) and sodium nitroprusside may be
attributed to the formation of S-nitrosocysteine. 3. Relaxations mediated by the
nitroxyl anion (0.3 microM) donated from Angeli's salt were more prolonged than
those produced by NO(*), and nitroxyl-induced relaxations were reduced by L
cysteine (1 and 3 mM). 4. EDRF-mediated relaxations produced by acetylcholine
(0.01 - 10 microM), ATP (3 - 100 microM) and the calcium ionophore A23187 (0.1
microM) were significantly reduced by 3 mM L-cysteine. 5. The similarity between
the inhibitory effects of L-cystei on responses to EDRF and on those to nitroxyl
suggests that a component of the response to EDRF may be mediated by nitroxyl
anion.
PMID- 10694239
TI - Effects of mefloquine on cardiac contractility and electrical activity in vivo,
in isolated cardiac preparations, and in single ventricular myocytes.
AB - 1. To examine the possible cardiotoxicity of the antimalarial drug mefloquine,
increasing doses (0.3 - 30 mg kg(-1)) were given i.v. to anaesthetized guinea
pigs. Mefloquine did not alter ECG intervals significantly but gradually
increased systolic blood pressure (at 3 mg kg(-1)) then had a depressor effect
(at 10 mg kg(-1)). Death due to profound hypotension, probably resulting from
cardiac contractile failure or AV block, occurred after either 10 mg kg(-1) (2/6)
or 30 mg kg(-1) (4/6) mefloquine. 2. In isolated cardiac preparations mefloquine
(3 - 100 microM) did not alter the effective refractory period but at the higher
concentrations resting tension increased. Developed tension was reduced by 100
microM mefloquine in left atria (from 5.8+/-1.7 to 2.2+/-0.4 mN) whereas in
papillary muscles although 30 microM mefloquine reduced developed tension (from
2. 6+/-0.5 to 1.1+/-0.1 mN) subsequent addition of 100 microM caused a marked,
but not sustained, positive inotropic effect (from 1.2+/-0.1 to 3.8+/-0.8 mN). 3.
In single ventricular myocytes, mefloquine (10 microM) shortened action potential
duration (e.g. APD(90) from 285+/-29 to 141+/-12 ms) and reduced the amplitude of
the systolic Ca(2+) transient. 4. These effects were accompanied by a decrease in
the L-type Ca(2+) current. These results indicate that the main adverse effect of
mefloquine on the heart is a negative inotropic action. This action can be
explained by blockade of L-type Ca(2+) channels.
PMID- 10694240
TI - Primary porcine enterocyte and hepatocyte cultures to study drug oxidation
reactions.
AB - 1. Primary porcine hepatocytes and enterocytes were isolated and cultured in
Williams' E medium for up to 10 days to investigate potential organ differences
in the metabolism of the immunosuppressive compound tacrolimus (FK 506) and of
two investigational drugs (KC11346 and KC12291). Using LC-MS (FK506) and HPLC-FL
(KC 11346/12291) a number of metabolites with identical mass and/or identical
retention time could be detected. 2. In the case of tacrolimus hepatocytes and
enterocytes produced the same spectrum of metabolites, e.g. bisdemethyl
tacrolimus, demethyl-tacrolimus, demethyl-hydroxy-tacrolimus and hydroxy
tacrolimus, albeit at varying intensities. 3. Treatment of enterocyte cultures
with dexamethasone increased the overall metabolite formation very significantly
(up to 36 fold). 4. The metabolism of tacrolimus was also studied with
preparations of insect cells, that express specifically high levels of individual
human cytochrome P450 (CYP) isoenzymes. All metabolites could be generated with
microsomal preparations specifically expressing CYP3A4, but hydroxy-tacrolimus
was exclusively produced by CYP3A5. 5. In the case of the investigational drugs
KC 11346 and KC 12291 only three metabolites were formed by cultured enterocytes
whereas hepatocytes produced 10 and 20 metabolites, respectively. 6. When
assessed at the protein level CYP1A and CYP3A were expressed in cultures of
porcine enterocytes for up to 10 days but porcine hepatocytes expressed
additionally CYP2C9/10. 7. In conclusion, primary enterocytes and hepatocytes can
be successfully cultured for several days while maintaining mono-oxygenase
activity and may therefore be used as a tool for studying intestinal and hepatic
metabolism.
PMID- 10694241
TI - A comparison of the anti-inflammatory and anti-nociceptive activity of
nitroaspirin and aspirin.
AB - 1. Nitroaspirin (2.5 - 50 mg kg(-1), i.p. or 2.5 - 100 mg kg(-1), p.o.) and
aspirin (2.5 - 100 mg kg(-1), i.p. or p.o.) exhibit anti-inflammatory activity in
the carrageenan-induced hindpaw oedema model in the rat. When administered i.p.,
nitroaspirin was a more effective anti-oedema agent than aspirin particularly in
the 'early' phase (i.e. up to 60 min) of the response. The ED(50) values for
nitroaspirin and aspirin as inhibitors of the 'late' phase response (measured at
180 min) were 64.3 micromol kg(-1) and >555 micromol kg(-1), respectively. When
administered p.o., neither nitroaspirin nor aspirin exhibited significant anti
inflammatory activity in the 'early' phase and were of similar potency in the
'late' phase. Thus, at the highest dose used (100 mg kg(-1), 360 min) orally
administered nitroaspirin (aspirin in parenthesis) inhibited oedema formation by
46.9+/-1.6% (47.2+/-3.8%, both n=6, P<0.05). 2. Nitroaspirin and aspirin (25 -
200 mg kg(-1), p.o.) caused dose-related inhibition of the hyperalgesia to
mechanical stimulation following intraplantar injection of carrageenan in the
rat. ED(50) values were 365 micromol kg(-1) and 784 micromol kg(-1),
respectively. Neither drug influenced the threshold for mechanical stimulation in
the contralateral (i.e. untreated) hindpaw. 3. Nitroaspirin and aspirin (2.5 -
100 mg kg(-1), p.o.) caused dose-related inhibition of acetic acid induced
abdominal constrictions in the mouse (ED(50) values of 154.7 micromol kg(-1) and
242.8 micromol kg(-1), respectively). 4. Nitroaspirin and aspirin (>200 mg kg(
1), p.o.) reduced the 'late' phase (but not the 'early' phase) of the formalin
induced hindpaw licking assay in the mouse. Similarly, nitroaspirin and aspirin
(>50 mg kg(-1), p.o.) prolonged tail withdrawal latency following application of
a noxious heat stimulus in the mouse.
PMID- 10694242
TI - Effects of spinally administered P2X receptor agonists and antagonists on the
responses of dorsal horn neurones recorded in normal, carrageenan-inflamed and
neuropathic rats.
AB - 1. The function and role of P2X receptors in the spinal transmission of
nociception was investigated using the selective P2X receptor agonists,
alpha,beta-methylene ATP (alpha,beta-me ATP) and beta, gamma-methylene-L-ATP
(beta,gamma-me-L-ATP) and the P2X receptor antagonists pyridoxal-phosphate-6
azophenyl-2',4'-disulphonate (PPADS) and suramin. 2. Intrathecal administration
of 5 and 50 microg of beta,gamma-me-L-ATP produced a significant facilitation of
the C-fibre evoked response and a tendency towards increased excitability of the
post-discharge, but not Abeta-fibre evoked response of dorsal horn neurones
recorded in normal animals. Administration of similar doses of alpha,beta-me ATP
did not produce an overall change in the response of the neuronal population. 3.
Peripheral administration of 20 microg of these agonists into the paw of the rat
evoked firing in the dorsal horn neurones. 4. Intrathecal administration of the
antagonists, suramin (50 and 500 microg) and PPADS (5, 50 and 500 microg), to
normal animals and to animals with a model of neuropathy induced by spinal nerve
ligation did not alter the evoked neuronal responses. In contrast, intrathecal
administration of 500 microg of suramin to animals 3 h after the induction of
carrageenan inflammation produced a significant inhibition of the C-fibre evoked
response of the neurones. Similar inhibitions were also seen following high doses
of intrathecal PPADS, although this did not reach significance. 5. These results
suggest that spinal P2X receptors may play a role in the modulation of spinal
nociceptive transmission following the development of inflammation, but that
these receptors play at most a minor role in spinal nociceptive processing in
normal and neuropathic animals.
PMID- 10694243
TI - Antagonism of calcium currents and neurotransmitter release by barium ions at
frog motor nerve endings.
AB - 1. The effects of Ba(2+) (0.1 - 2 mM) on the component of the perineural voltage
change associated with nerve terminal calcium currents (prejunctional Ca(2+)
currents) were compared with the effects of this ion to antagonize calcium
dependent acetylcholine (ACh) release. These experiments were made on isolated
neuromuscular junctions of the frog. 2. In the presence of sufficient
concentrations of K(+) channel blockers to eliminate measurable prejunctional
K(+) currents, low concentrations of Ba(2+) selectively antagonized prejunctional
Ca(2+) currents in normal Ca(2+) solutions. Higher concentrations of Ba(2+) also
substantially reduced the Na(+) component of the perineural waveform. 3. Ba(2+)
inhibited the prolonged prejunctional Ca(2+) currents that developed in the
presence of higher concentrations of K(+) channel blockers. 4. Simultaneous
measurements of the prejunctional Ca(2+) currents and the electrophysiological
correlates of ACh release (i.e. end-plate potentials, EPPs) were made under
conditions of modest K(+) channel blockade. Under these conditions, Ba(2+)
generally produced simultaneous decreases in both Ca(2+) currents and EPP
amplitudes. In some instances, a prolongation of prejunctional Ca(2+) currents
and a transient increase in EPP amplitudes preceded the decreases in both
electrophysiological events. 5. These results suggest that Ba(2+) ions can
antagonize the entry of calcium into motor nerve endings and this effect is
likely to be responsible for the inhibitory effects of Ba(2+) on evoked ACh
release.
PMID- 10694244
TI - Inhibition by troglitazone of the antigen-induced production of leukotrienes in
immunoglobulin E-sensitized RBL-2H3 cells.
AB - 1. The effect of troglitazone, an anti-diabetic drug with insulin-sensitizing
action, on antigen-induced production of leukotriene (LT) B(4), C(4) and E(4) and
prostaglandin D(2) (PGD(2)) was examined in dinitrophenol (DNP)-specific
immunoglobulin E (IgE)-sensitized RBL-2H3 mast cells following stimulation by the
antigen, DNP-conjugated human serum albumin. Levels of LTB(4), C(4) and E(4) and
PGD(2) in the conditioned medium were enzyme-immunoassayed. 2. Troglitazone
inhibited the antigen-induced production of LTB(4), C(4) and E(4) and the potency
of the inhibition was comparable to that of zileuton, a specific inhibitor of 5
lipoxygenase (5-LOX) and a clinically used anti-asthmatic drug. Neither
troglitazone nor zileuton affected antigen-induced production of PGD(2),
arachidonic acid release from membrane phospholipids and degranulation. 3.
Troglitazone inhibited LTB(4) production by the supernatant fraction of RBL-2H3
cell lysate with similar potency to zileuton, suggesting that troglitazone
inhibits LT production by direct inhibition of 5-LOX activity. 4. Furthermore, it
was shown that troglitazone as well as zileuton inhibited LTB(4) production in
A23187-stimulated rat peritoneal neutrophils. 5. These findings suggest that
troglitazone inhibits antigen-induced LT production in the IgE-sensitized RBL-2H3
cells and A23187-stimulated rat peritoneal neutrophils by direct inhibition of 5
LOX activity.
PMID- 10694245
TI - Tonic activation of A(2A) adenosine receptors unmasks, and of A(1) receptors
prevents, a facilitatory action of calcitonin gene-related peptide in the rat
hippocampus.
AB - 1. We investigated how manipulations of the degree of activation of adenosine
A(1) and A(2A) receptors influences the action of the neuropeptide, calcitonin
gene-related peptide (CGRP) on synaptic transmission in hippocampal slices. Field
excitatory post-synaptic potentials (EPSPs) from the CA1 area were recorded. 2.
When applied alone, CGRP (1 - 30 nM) was without effect on field EPSPs. However,
CGRP (10 - 30 nM) significantly increased the field EPSP slope when applied to
hippocampal slices in the presence of the A(1) receptor antagonist, 1,3-dipropyl
8-cyclopenthyl xanthine (DPCPX, 10 nM), or in the presence of the A(2A) adenosine
receptor agonist CGS 21680 (10 nM). 3. The A(2A) receptor antagonist, ZM 241385
(10 nM) as well as adenosine deaminase (ADA, 2 U ml(-1)), prevented the
enhancement of field EPSP slope caused by CGRP (30 nM) in the presence of DPCPX
(10 nM), suggesting that this effect of CGRP requires the concomitant activation
of A(2A) adenosine receptors by endogenous adenosine. 4. The protein kinase-A
inhibitors, N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA-1004, 10 microM)
and adenosine 3',5'-cyclic monophosphorothioate, Rp-isomer (Rp-cAMPS, 50 microM),
as well as the inhibitor of ATP-sensitive potassium (K(ATP)) channels,
glibenclamide (30 microM), prevented the facilitation of synaptic transmission
caused by CGRP (30 nM) in the presence of DPCPX (10 nM), suggesting that this
effect of CGRP involves both K(ATP) channels and protein kinase-A. 5. It is
concluded that the ability of CGRP to facilitate synaptic transmission in the CA1
area of the hippocampus is under tight control by adenosine, with tonic A(1)
receptor activation by endogenous adenosine 'braking' the action of CGRP, and the
A(2A) receptors triggering this action.
PMID- 10694246
TI - An indirect influence of phenylephrine on the release of endothelium-derived
vasodilators in rat small mesenteric artery.
AB - 1. The possibility that stimulation of smooth muscle alpha(1)-adrenoceptors
modulates contraction via the endothelium was examined in rat small mesenteric
arteries. 2. N(omega)-nitro-L-arginine methyl ester, (L-NAME, 100 microM to
inhibit NO synthase) increased contraction to single concentrations of
phenylephrine (1 - 3 microM) by approximately 2 fold (from a control level of
14.2+/-3.0 to 34. 1+/-4.2% of the maximum contraction of the artery, n=20). The
action of L-NAME was abolished by disrupting the endothelium. 3. The subsequent
addition of apamin (to inhibit small conductance Ca(2+)-activated K(+) channels,
50 nM) further augmented phenylephrine contractions, in an endothelium-dependent
manner, to more than 3 fold above control (50.4+/-5.3% of the maximum
contraction, n=11). 4.Charybdotoxin (non-selective inhibitor of large conductance
Ca(2+)-activated K(+) channels, BK(Ca), 50 nM) plus L-NAME augmented the level of
phenylephrine contraction to 4 - 5-fold above control (64.1+/-3.1%, n=5), but
this effect was independent of the endothelium. The potentiation of contraction
by charybdotoxin could be mimicked with the selective BK(Ca) inhibitor,
iberiotoxin,. 5. Apamin together with L-NAME and charybdotoxin further
significantly increased the phenylephrine contraction by 5 - 6-fold, to 79.9+/
3.5% of the maximum contraction of the artery (n=13). 6. Phenylephrine failed
directly to increase the intracellular Ca(2+) concentration in endothelial cells
freshly isolated from the small mesenteric artery. 7. Stimulation of smooth
muscle alpha(1)-adrenoceptors in the mesenteric artery induces contraction that
is markedly suppressed by the endothelium. The attenuation of contraction appears
to reflect both the release of NO from the endothelium and the efflux of K(+)
from both endothelial and smooth muscle cells. This suggests that the release of
NO and endothelium-derived hyperpolarizing factor can be evoked indirectly by
agents which act only on the smooth muscle cells.
PMID- 10694247
TI - Functional characterization of the P2X(4) receptor orthologues.
AB - 1. The aim of this study was to functionally characterize the recombinant mouse
P2X(4) receptor and to compare its pharmacological properties with those of the
human and rat orthologues. 2. Whole cell recordings were made from rafts of HEK
293 cells stably expressing recombinant mouse, rat or human P2X(4) receptors,
using Cs-aspartate containing electrodes (3 - 8 MOmega) in a HEPES-buffered
extracellular medium. 3. The agonist potency of ATP at the three species
orthologues was similar, with mean EC(50) values of 2.3 microM, 1.4 microM and
5.5 microM, respectively. 4. Adenosine-5'-tetraphosphate (AP4) acted as a partial
agonist with respect to ATP at the mouse and human P2X(4) receptors (EC(50)=2.6
and 3.0 microM), but was significantly less potent at the rat orthologue
(EC(50)=20.0 microM). alpha,beta-methylene adenosine-5'-triphosphate (alpha,beta
meATP) also acted as a partial agonist, producing 29% of the maximum response at
the mouse P2X(4) and 24% at the human P2X(4) receptor. 5. In contrast to the
other species orthologues, alpha,beta-meATP failed to elicit a significant
agonist response at rat P2X(4) receptors, and was found to act as an antagonist,
with an IC(50) of 4.6 microM, against 10 microM ATP. 6. Mouse P2X(4) receptors
were found to be sensitive to the antagonist, pyridoxalphosphate-6-azophenyl
2',4'-disulphonic acid (PPADS) (IC(50)=10.5 microM), as were human P2X(4)
receptors (IC(50)=9.6 microM). The rat receptor however, showed a low sensitivity
to PPADS (IC(50)>100 microM). 7. All three orthologues were relatively suramin
insensitive (IC(50)>100 microM) and insensitive to 1-[N, O-Bis(5-isoquinoline
sulphonyl)benzyl]-2-(4-phenylpiperazine)ethyl]-5-isoquinoline sulphonamide (KN
62; IC(50)>3 microM). 8. Our results suggest that the pharmacological properties
of the mouse receptor are most similar to the human P2X(4) receptor, and differ
markedly from the rat receptor.
PMID- 10694248
TI - Impaired relaxation of stomach smooth muscle in mice lacking cyclic GMP-dependent
protein kinase I.
AB - 1. Guanosine 3', 5'-cyclic monophosphate (cyclic GMP)-dependent kinase I (cGKI)
is a major receptor for cyclic GMP in a variety of cells. Mice lacking cGKI
exhibit multiple phenotypes, including severe defects in smooth muscle function.
We have investigated the NO/cGMP- and vasoactive intestinal polypeptide
(VIP)/adenosine 3', 5'-cyclic monophosphate (cyclic AMP)-signalling pathways in
the gastric fundus of wild type and cGKI-deficient mice. 2. Using
immunohistochemistry, similar staining patterns for NO-synthase, cyclic GMP- and
VIP-immunoreactivities were found in wild type and cGKI-deficient mice. 3. In
isolated, endothelin-1 (3 nM - 3 microM)-contracted, muscle strips from wild type
mice, electrical field stimulation (1 - 16 Hz) caused a biphasic relaxation, one
initial rapid, followed by a more slowly developing phase. In preparations from
cGKI-deficient mice only the slowly developing relaxation was observed. 4. The
responses to the NO donor, SIN-1 (10 nM - 100 microM), and to 8-Br-cyclic GMP (10
nM - 100 microM) were markedly impaired in strips from cGKI-deficient mice,
whereas the responses to VIP (0.1 nM - 1 microM) and forskolin (0.1 nM - 1
microM) were similar to those in wild type mice. 5. These results suggest that
cGKI plays a central role in the NO/cGMP signalling cascade producing relaxation
of mouse gastric fundus smooth muscle. Relaxant agents acting via the cyclic AMP
pathway can exert their effects independently of cGKI.
PMID- 10694249
TI - Modulation by bicuculline and penicillin of the block by t-butyl-bicyclo
phosphorothionate (TBPS) of GABA(A)-receptor mediated Cl(-)-current responses in
rat striatal neurones.
AB - 1. T-butyl-bicyclo-phosphorothionate (TBPS) is a prototypical representative of
the cage-convulsants which act through a use-dependent block of the GABA(A)
receptor-ionophore complex. Using current recordings from cultured neurones of
rat striatum the manner was investigated in which two antagonists, bicuculline
and penicillin, presumably acting at the agonist binding site and in the ionic
channel, respectively, modify the rate of block by TBPS. 2. Penicillin (5 or 10
mM) did not slow the rate of block by TBPS, but produced a significant
enhancement of block rate, which, however, was inversely related to the degree of
antagonism by penicillin of the GABA-induced current. 3. Bicuculline (10 microM)
reduced the rate of block by TBPS. However, this effect was 3 fold weaker than
its GABA-antagonistic action. The slowing of block rate and the current
antagonism exhibited a biphasic, positive-negative relationship. Co-application
of bicuculline (100 microM) in a concentration that produced nearly complete
antagonism and TBPS (10 microM) resulted in a marked ( approximately 40%)
reduction of subsequent GABA response amplitudes compatible with a direct,
bicuculline-induced conformational change in the receptor required for the
binding of and block by TBPS. 4. The lack of protection afforded by the channel
blocker penicillin as well as the lack of correlation between bicuculline
antagonism of the Cl(-)-current and its efficiency in protecting against TBPS
block is evidence against an open channel blocking mechanism for TBPS. TBPS does,
therefore, not appear to gain access to its binding site via the open pore but
through alternative routes regulated from the agonist binding site.
PMID- 10694250
TI - Quantification of state-dependent drug interactions with the sodium channel.
PMID- 10694251
TI - Reply
PMID- 10694252
TI - Trapping of a methanesulfonanilide by closure of the HERG potassium channel
activation gate.
AB - Deactivation of voltage-gated potassium (K(+)) channels can slow or prevent the
recovery from block by charged organic compounds, a phenomenon attributed to
trapping of the compound within the inner vestibule by closure of the activation
gate. Unbinding and exit from the channel vestibule of a positively charged
organic compound should be favored by membrane hyperpolarization if not impeded
by the closed gate. MK-499, a methanesulfonanilide compound, is a potent blocker
(IC(50) = 32 nM) of HERG K(+) channels. This bulky compound (7 x 20 A) is
positively charged at physiological pH. Recovery from block of HERG channels by
MK-499 and other methanesulfonanilides is extremely slow (Carmeliet 1992; Ficker
et al. 1998), suggesting a trapping mechanism. We used a mutant HERG (D540K)
channel expressed in Xenopus oocytes to test the trapping hypothesis. D540K HERG
has the unusual property of opening in response to hyperpolarization, in addition
to relatively normal gating and channel opening in response to depolarization
(Sanguinetti and Xu 1999). The hyperpolarization-activated state of HERG was
characterized by long bursts of single channel reopening. Channel reopening
allowed recovery from block by 2 microM MK-499 to occur with time constants of
10.5 and 52.7 s at -160 mV. In contrast, wild-type HERG channels opened only
briefly after membrane hyperpolarization, and thus did not permit recovery from
block by MK-499. These findings provide direct evidence that the mechanism of
slow recovery from HERG channel block by methanesulfonanilides is due to trapping
of the compound in the inner vestibule by closure of the activation gate. The
ability of HERG channels to trap MK-499, despite its large size, suggests that
the vestibule of this channel is larger than the well studied Shaker K(+)
channel.
PMID- 10694253
TI - Single-channel properties in endoplasmic reticulum membrane of recombinant type 3
inositol trisphosphate receptor.
AB - The inositol 1,4,5-trisphosphate receptor (InsP(3)R) is an intracellular Ca(2+)
release channel localized in endoplasmic reticulum (ER) with a central role in
complex Ca(2+) signaling in most cell types. A family of InsP(3)Rs encoded by
several genes has been identified with different primary sequences, subcellular
locations, variable ratios of expression, and heteromultimer formation. This
diversity suggests that cells require distinct InsP(3)Rs, but the functional
correlates of this diversity are largely unknown. Lacking are single-channel
recordings of the recombinant type 3 receptor (InsP(3)R-3), a widely expressed
isoform also implicated in plasma membrane Ca(2+) influx and apoptosis. Here, we
describe functional expression and single-channel recording of recombinant rat
InsP(3)R-3 in its native membrane environment. The approach we describe suggests
a novel strategy for expression and recording of recombinant ER-localized ion
channels in the ER membrane. Ion permeation and channel gating properties of the
rat InsP(3)R-3 are strikingly similar to those of Xenopus type 1 InsP(3)R in the
same membrane. Using two different two-electrode voltage clamp protocols to
examine calcium store-operated calcium influx, no difference in the magnitude of
calcium influx was observed in oocytes injected with rat InsP(3)R-3 cRNA compared
with control oocytes. Our results suggest that if cellular expression of multiple
InsP(3)R isoforms is a mechanism to modify the temporal and spatial features of
[Ca(2+)](i) signals, then it must be achieved by isoform-specific regulation or
localization of various types of InsP(3)Rs that have relatively similar Ca(2+)
permeation properties.
PMID- 10694254
TI - Independence and cooperativity in rearrangements of a potassium channel voltage
sensor revealed by single subunit fluorescence.
AB - Voltage-gated potassium channels are composed of four subunits. Voltage-dependent
activation of these channels consists of a depolarization-triggered series of
charge-carrying steps that occur in each subunit. These major charge-carrying
steps are followed by cooperative step(s) that lead to channel opening. Unlike
the late cooperative steps, the major charge-carrying steps have been proposed to
occur independently in each of the channel subunits. In this paper, we examine
this further. We showed earlier that the two major charge-carrying steps are
associated with two sequential outward transmembrane movements of the charged S4
segment. We now use voltage clamp fluorometry to monitor these S4 movements in
individual subunits of heterotetrameric channels. In this way, we estimate the
influence of one subunit's S4 movement on another's when the energetics of their
transmembrane movements differ. Our results show that the first S4 movement
occurs independently in each subunit, while the second occurs cooperatively. At
least part of the cooperativity appears to be intrinsic to the second S4 charge
carrying rearrangement. Such cooperativity in gating of voltage-dependent
channels has great physiological relevance since it can affect both action
potential threshold and rate of propagation.
PMID- 10694255
TI - The barium site in a potassium channel by x-ray crystallography.
AB - X-ray diffraction data were collected from frozen crystals (100 degrees K) of the
KcsA K(+) channel equilibrated with solutions containing barium chloride.
Difference electron density maps (F(barium) - F(native), 5.0 A resolution) show
that Ba(2+) resides at a single location within the selectivity filter. The
Ba(2+) blocking site corresponds to the internal aspect (adjacent to the central
cavity) of the "inner ion" position where an alkali metal cation is found in the
absence of the blocking Ba(2+) ion. The location of Ba(2+) with respect to Rb(+)
ions in the pore is in good agreement with the findings on the functional
interaction of Ba(2+) with K(+) (and Rb(+)) in Ca(2+)-activated K(+) channels
(Neyton, J., and C. Miller. 1988. J. Gen. Physiol. 92:549-567). Taken together,
these structural and functional data imply that at physiological ion
concentrations a third ion may interact with two ions in the selectivity filter,
perhaps by entering from one side and displacing an ion on the opposite side.
PMID- 10694256
TI - Modulating modulation.
PMID- 10694257
TI - Modulation of N-type calcium channel activity by G-proteins and protein kinase C.
AB - N-type voltage-gated calcium channel activity in rat superior cervical ganglion
neurons is modulated by a variety of pathways. Activation of heterotrimeric G
proteins reduces whole-cell current amplitude, whereas phosphorylation by protein
kinase C leads to an increase in current amplitude. It has been proposed that
these two distinct pathways converge on the channel's pore-forming alpha(1B)
subunit, such that the actions of one pathway can preclude those of the other. In
this study, we have characterized further the actions of PKC on whole-cell barium
currents in neonatal rat superior cervical ganglion neurons. We first examined
whether the effects of G-protein-mediated inhibition and phosphorylation by PKC
are mutually exclusive. G-proteins were activated by including 0.4 mM GTP or 0.1
mM GTP-gamma-S in the pipette, and PKC was activated by bath application of 500
nM phorbol 12-myristate 13-acetate (PMA). We found that activated PKC was unable
to reverse GTP-gamma-S-induced inhibition unless prepulses were applied,
indicating that reversal of inhibition by phosphorylation appears to occur only
after dissociation of the G-protein from the channel. Once inhibition was
relieved, activation of PKC was sufficient to prevent reinhibition of current by
G-proteins, indicating that under phosphorylating conditions, channels are
resistant to G-protein-mediated modulation. We then examined what effect, if any,
phosphorylation by PKC has on N-type barium currents beyond antagonizing G
protein-mediated inhibition. We found that, although G-protein activation
significantly affected peak current amplitude, fast inactivation, holding
potential-dependent inactivation, and voltage-dependent activation, when G
protein activation was minimized by dialysis of the cytoplasm with 0.1 mM GDP
beta-S, these parameters were not affected by bath application of PMA. These
results indicate that, under our recording conditions, phosphorylation by PKC has
no effect on whole-cell N-type currents, other than preventing inhibition by G
proteins.
PMID- 10694258
TI - Cytoplasmic unsaturated free fatty acids inhibit ATP-dependent gating of the G
protein-gated K(+) channel.
AB - This study reports the identification of an endogenous inhibitor of the G protein
gated (K(ACh)) channel and its effect on the K(ACh) channel kinetics. In the
presence of acetylcholine in the pipette, K(ACh) channels in inside-out atrial
patches were activated by applying GTP to the cytoplasmic side of the membrane.
In these patches, addition of physiological concentration of intracellular ATP (4
mM) upregulated K(ACh) channel activity approximately fivefold and induced long
lived openings. However, such ATP-dependent gating is normally not observed in
cell-attached patches, indicating that an endogenous substance that inhibits the
ATP effect is present in the cell. We searched for such an inhibitor in the cell.
ATP-dependent gating of the K(ACh) channel was inhibited by the addition of the
cytosolic fraction of rat atrial or brain tissues. The lipid component of the
cytosolic fraction was found to contain the inhibitory activity. To identify the
lipid inhibitor, we tested the effect of approximately 40 different lipid
molecules. Among the lipids tested, only unsaturated free fatty acids such as
oleic, linoleic, and arachidonic acids (0.2-2 microM) reversibly inhibited the
ATP-dependent gating of native K(ACh) channels in atrial cells and hippocampal
neurons, and of recombinant K(ACh) channels (GIRK1/4 and GIRK1/2) expressed in
oocytes. Unsaturated free fatty acids also inhibited phosphatidylinositol-4, 5
bisphosphate (PIP(2))-induced changes in K(ACh) channel kinetics but were
ineffective against ATP-activated background K(1) channels and PIP(2)-activated
K(ATP) channels. These results show that during agonist-induced activation,
unsaturated free fatty acids in the cytoplasm help to keep the cardiac and
neuronal K(ACh) channels downregulated by antagonizing their ATP-dependent
gating. The opposing effects of ATP and free fatty acids represent a novel
regulatory mechanism for the G protein-gated K(+) channel.
PMID- 10694259
TI - Activation of Drosophila sodium channels promotes modification by deltamethrin.
Reductions in affinity caused by knock-down resistance mutations.
AB - kdr and super-kdr are mutations in houseflies and other insects that confer 30-
and 500-fold resistance to the pyrethroid deltamethrin. They correspond to single
(L1014F) and double (L1014F+M918T) mutations in segment IIS6 and linker II(S4-S5)
of Na channels. We expressed Drosophila para Na channels with and without these
mutations and characterized their modification by deltamethrin. All wild-type
channels can be modified by <10 nM deltamethrin, but high affinity binding
requires channel opening: (a) modification is promoted more by trains of brief
depolarizations than by a single long depolarization, (b) the voltage dependence
of modification parallels that of channel opening, and (c) modification is
promoted by toxin II from Anemonia sulcata, which slows inactivation. The
mutations reduce channel opening by enhancing closed-state inactivation. In
addition, these mutations reduce the affinity for open channels by 20- and 100
fold, respectively. Deltamethrin inhibits channel closing and the mutations
reduce the time that channels remain open once drug has bound. The super-kdr
mutations effectively reduce the number of deltamethrin binding sites per channel
from two to one. Thus, the mutations reduce both the potency and efficacy of
insecticide action.
PMID- 10694260
TI - Extracellular Mg(2+) modulates slow gating transitions and the opening of
Drosophila ether-a-Go-Go potassium channels.
AB - We have characterized the effects of prepulse hyperpolarization and extracellular
Mg(2+) on the ionic and gating currents of the Drosophila ether-a-go-go K(+)
channel (eag). Hyperpolarizing prepulses significantly slowed channel opening
elicited by a subsequent depolarization, revealing rate-limiting transitions for
activation of the ionic currents. Extracellular Mg(2+) dramatically slowed
activation of eag ionic currents evoked with or without prepulse
hyperpolarization and regulated the kinetics of channel opening from a nearby
closed state(s). These results suggest that Mg(2+) modulates voltage-dependent
gating and pore opening in eag channels. To investigate the mechanism of this
modulation, eag gating currents were recorded using the cut-open oocyte voltage
clamp. Prepulse hyperpolarization and extracellular Mg(2+) slowed the time course
of ON gating currents. These kinetic changes resembled the results at the ionic
current level, but were much smaller in magnitude, suggesting that prepulse
hyperpolarization and Mg(2+) modulate gating transitions that occur slowly and/or
move relatively little gating charge. To determine whether quantitatively
different effects on ionic and gating currents could be obtained from a
sequential activation pathway, computer simulations were performed. Simulations
using a sequential model for activation reproduced the key features of eag ionic
and gating currents and their modulation by prepulse hyperpolarization and
extracellular Mg(2+). We have also identified mutations in the S3-S4 loop that
modify or eliminate the regulation of eag gating by prepulse hyperpolarization
and Mg(2+), indicating an important role for this region in the voltage-dependent
activation of eag.
PMID- 10694261
TI - Impaired calcium release in cerebellar Purkinje neurons maintained in culture.
AB - Cerebellar Purkinje neurons demonstrate a form of synaptic plasticity that, in
acutely prepared brain slices, has been shown to require calcium release from the
intracellular calcium stores through inositol trisphosphate (InsP(3)) receptors.
Similar studies performed in cultured Purkinje cells, however, find little
evidence for the involvement of InsP(3) receptors. To address this discrepancy,
the properties of InsP(3)- and caffeine-evoked calcium release in cultured
Purkinje cells were directly examined. Photorelease of InsP(3) (up to 100 microM)
from its photolabile caged analogue produced no change in calcium levels in 70%
of cultured Purkinje cells. In the few cells where a calcium increase was
detected, the response was very small and slow to peak. In contrast, the same
concentration of InsP(3) resulted in large and rapidly rising calcium responses
in all acutely dissociated Purkinje cells tested. Similar to InsP(3), caffeine
also had little effect on calcium levels in cultured Purkinje cells, yet evoked
large calcium transients in all acutely dissociated Purkinje cells tested. The
results demonstrate that calcium release from intracellular calcium stores is
severely impaired in Purkinje cells when they are maintained in culture. Our
findings suggest that cultured Purkinje cells are an unfaithful experimental
model for the study of the role of calcium release in the induction of cerebellar
long term depression.
PMID- 10694262
TI - Mitochondrial memory banks. Calcium stores keep a record of neuronal stimulation.
PMID- 10694263
TI - Dissection of mitochondrial Ca2+ uptake and release fluxes in situ after
depolarization-evoked [Ca2+](i) elevations in sympathetic neurons.
AB - We studied how mitochondrial Ca2+ transport influences [Ca2+](i) dynamics in
sympathetic neurons. Cells were treated with thapsigargin to inhibit Ca2+
accumulation by SERCA pumps and depolarized to elevate [Ca2+(i); the recovery
that followed repolarization was then examined. The total Ca2+ flux responsible
for the [Ca2+](i) recovery was separated into mitochondrial and nonmitochondrial
components based on sensitivity to the proton ionophore FCCP, a selective
inhibitor of mitochondrial Ca2+ transport in these cells. The nonmitochondrial
flux, representing net Ca2+ extrusion across the plasma membrane, has a simple
dependence on [Ca2+](i), while the net mitochondrial flux (J(mito)) is biphasic,
indicative of Ca+) accumulation during the initial phase of recovery when
[Ca2+](i) is high, and net Ca2+ release during later phases of recovery. During
each phase, mitochondrial Ca2+ transport has distinct effects on recovery
kinetics. J(mito) was separated into components representing mitochondrial Ca2+
uptake and release based on sensitivity to the specific mitochondrial Na(+)/Ca2+
exchange inhibitor, CGP 37157 (CGP). The CGP-resistant (uptake) component of
J(mito) increases steeply with [Ca2+](i), as expected for transport by the
mitochondrial uniporter. The CGP-sensitive (release) component is inhibited by
lowering the intracellular Na(+) concentration and depends on both intra- and
extramitochondrial Ca2+ concentration, as expected for the Na(+)/Ca2+ exchanger.
Above approximately 400 nM [Ca2+](i), net mitochondrial Ca2+ transport is
dominated by uptake and is largely insensitive to CGP. When [Ca2+](i) is
approximately 200-300 nM, the net mitochondrial flux is small but represents the
sum of much larger uptake and release fluxes that largely cancel. Thus,
mitochondrial Ca2+ transport occurs in situ at much lower concentrations than
previously thought, and may provide a mechanism for quantitative control of ATP
production after brief or low frequency stimuli that raise [Ca(2+)](i) to levels
below approximately 500 nM.
PMID- 10694265
TI - Preimplantation genetic diagnosis of a reciprocal translocation
t(3;11)(q27.3;q24.3) in siblings.
AB - Preimplantation genetic diagnosis (PGD) was performed in two couples to avoid
chromosomally unbalanced progeny in a family in which a brother and a sister
carry an identical maternally inherited balanced translocation
t(3;11)(q27.3;q24.3). Embryos were biopsied 3 days after fertilization and
blastomeres were analysed by fluorescent in-situ hybridization (FISH). Embryos
were classified as unbalanced or normal/balanced. In the first case, the male
carrier and his wife underwent one IVF/PGD treatment cycle. In all, 18 embryos
were analysed. Of those, 15 revealed an unbalanced karyotype. For one embryo,
results were not conclusive, from one embryo results were contradictory and one
embryo was classified as normal/balanced and subsequently transferred. A
singleton pregnancy was achieved. The PGD analysis was confirmed at 16 weeks
gestation by amniocentesis. At term, a healthy girl with a balanced karyotype was
born. Pregnancy and delivery were without complications. In the second case, the
female carrier and her husband underwent two IVF/PGD treatment cycles. During the
first cycle, three embryos were analysed. One embryo revealed an unbalanced
karyotype and two embryos were designated a normal/balanced karyotype and
transferred but no pregnancy was achieved. During the second PGD cycle three
embryos were analysed. Of those, none appeared suitable for transfer. The couple
decided not to undergo further treatment. Our results indicate that for
individuals carrying a reciprocal translocation PGD is a feasible approach to
obtain embryos with a normal chromosome balance and to avoid both spontaneous and
induced abortion.
PMID- 10694264
TI - Quantitative analysis of mitochondrial Ca2+ uptake and release pathways in
sympathetic neurons. Reconstruction of the recovery after depolarization-evoked
[Ca2+]i elevations.
AB - Rate equations for mitochondrial Ca2+ uptake and release and plasma membrane Ca2+
transport were determined from the measured fluxes in the preceding study and
incorporated into a model of Ca2+ dynamics. It was asked if the measured fluxes
are sufficient to account for the [Ca2+]i recovery kinetics after depolarization
evoked [Ca2+]i elevations. Ca2+ transport across the plasma membrane was
described by a parallel extrusion/leak system, while the rates of mitochondrial
Ca2+ uptake and release were represented using equations like those describing
Ca2+ transport by isolated mitochondria. Taken together, these rate descriptions
account very well for the time course of recovery after [Ca2+]i elevations evoked
by weak and strong depolarization and their differential sensitivity to FCCP, CGP
37157, and [Na+]i. The model also leads to three general conclusions about
mitochondrial Ca2+ transport in intact cells: (1) mitochondria are expected to
accumulate Ca2+ even in response to stimuli that raise [Ca2+]i only slightly
above resting levels; (2) there are two qualitatively different stimulus regimes
that parallel the buffering and non-buffering modes of Ca2+ transport by isolated
mitochondria that have been described previously; (3) the impact of mitochondrial
Ca2+ transport on intracellular calcium dynamics is strongly influenced by
nonmitochondrial Ca2+ transport; in particular, the magnitude of the prolonged
[Ca2+]i elevation that occurs during the plateau phase of recovery is related to
the Ca2+ set-point described in studies of isolated mitochondria, but is a
property of mitochondrial Ca2+ transport in a cellular context. Finally, the
model resolves the paradoxical finding that stimulus-induced [Ca2+]i elevations
as small as approximately 300 nM increase intramitochondrial total Ca2+
concentration, but the steady [Ca2+]i elevations evoked by such stimuli are not
influenced by FCCP.
PMID- 10694266
TI - The size of the CAG repeat in exon 1 of the androgen receptor gene shows no
significant relationship to impaired spermatogenesis in an infertile Caucasoid
sample of German origin.
AB - The androgen receptor (AR) gene, located on the X-chromosome at Xq11-12, contains
in exon 1 a polymorphic CAG repeat which codes for a polyglutamine tract.
Contractions of the CAG repeat are said to be related to prostate cancer. In
contrast, sizeable expansion of the CAG repeat can cause spinal and bulbar
muscular atrophy (SBMA). In infertile patients of Chinese origin and in a
Melbourne multinational population impaired sperm production has been postulated
to be related to moderate expansions of the polyglutamine tract. In a study of a
Swedish population of infertile patients these findings could not be
corroborated. The aim of our investigation was to examine the correlation between
the length of the CAG repeat and impaired sperm production in an infertile
Caucasoid patient sample of German ethnic origin. We found no statistically
significant relationship between the size of the CAG repeat or polyglutamine
tract and idiopathic impaired sperm production in the population studied. The
variability of the results by various investigators may be attributed to
different ethnic origins and hence different genetic modifiers of the populations
studied and/or to the high probability that these infertile males may represent a
heterogeneous group with respect to the causes of defective spermatogenesis.
PMID- 10694267
TI - Prostatic origin of a zinc binding high molecular weight protein complex in human
seminal plasma.
AB - The profile of the zinc ligand high molecular weight proteins was investigated in
the seminal plasma of 55 normozoospermic subjects by size exclusion high
performance liquid chromatography (HPLC). The proteins were recovered from
Sephadex G-75 gel filtration of seminal plasma in three zinc-containing fractions
which were then submitted to HPLC analysis. The results were, that in all the
samples, the protein profiles showed two peaks with apparent molecular weight of
approximately 660 and approximately 250 kDa. Dialysis experiments revealed that
both approximately 660 and approximately 250 kDa proteins were able to uptake
zinc against gradient indicating their zinc binding capacity. The HPLC analysis
of the whole seminal plasma evidenced only the approximately 660 kDa protein
complex as a single well quantifying peak, furthermore a positive correlation
between its peak area and the seminal zinc values (P < 0.001) was observed. This
suggested a prostatic origin of the approximately 660 kDa protein complex which
was then confirmed by the seminal plasma HPLC analysis of a subject with agenesis
of the Wolffian ducts. Finally the study demonstrated the presence of two zinc
binding proteins, approximately 660 and approximately 250 kDa respectively, in
human seminal plasma and the prostatic origin of the approximately 660 kDa.
PMID- 10694268
TI - Expression of protamine-1 and -2 mRNA during human spermiogenesis.
AB - During spermiogenesis, the histone-to-protamine replacement causes the compaction
of the spermatid chromatin. The genes for protamines, PRM-1 and PRM-2, are
transcribed in round and elongating spermatids. The transcripts are stored in a
translationally-repressed state by the binding of protein repressors before being
translated in elongating and elongated spermatids. RNA extracts from homogenized
whole testis samples supply only average data, and cell-specific and stage
specific expression cannot be addressed. Therefore, we used UV-laser-assisted
cell-picking (UV-LACP) to select spermatids of defined differentiation steps.
Subsequent reverse transcription-polymerase chain reaction (RT-PCR) with intron
spanning primer pairs allowed the detection of DNA-free and pseudogene-free PRM-1
and PRM-2 cDNA. Additional in-situ hybridization with digoxygenin-labelled cRNA
probes exhibited PRM-1 and PRM-2 mRNA from step 1/2 spermatids to step 4
spermatids, but not in elongated spermatids. RT-PCR revealed amplicons for PRM-1
and PRM-2 in all spermatids except step 3 round spermatids. Applying proteinase K
digestion, PRM-1 and PRM-2 transcripts were also detected in step 3 spermatids
indicating that protein repressors may bind to both PRM-1 and PRM-2 mRNA in step
3 round spermatids. These data demonstrate that the combination of UV-LACP and
non-radioactive in-situ hybridization appear to be a suitable approach for the
study of cell-specific and stage-specific gene expression during spermiogenesis.
PMID- 10694269
TI - Fatty acid composition of spermatozoa and immature germ cells.
AB - A great deal of attention has recently been given to the essential role of
polyunsaturated fatty acids (PUFA) of sperm membranes. We studied the fatty acid
composition of the immature germ cells (IGC) and of the sperm populations
separated by Percoll gradient in the ejaculate of normozoospermic patients. Fatty
acid pattern was analysed by combined gas chromatography-mass spectrometry on a
capillary column. In IGC, differences were found compared with mature
spermatozoa, with a higher percentage of saturated fatty acids and of essential
fatty acids. On the contrary, the long-chain PUFA were significantly lower in
IGC. The highest concentration of n3 PUFA docohexaenoic acid (DHA) was detected
in the spermatozoa deriving from 70-100% Percoll layers and a direct linear
correlation was found between the increase of DHA and increased percentage of
Percoll gradient. An inverse relationship between the percentage of atypical
sperm forms in each layer and the percentage of DHA was also observed. This study
demonstrates that the human germ cell line can elongate and desaturate essential
fatty acids and that the percentage of long-chain PUFA is correlated with the
normal morphology of sperm cells.
PMID- 10694270
TI - Sensitivity of mouse oocytes to nicotine-induced perturbations during oocyte
meiotic maturation and aneuploidy in vivo and in vitro.
AB - Oocyte meiosis is sensitive to endogenous and exogenous perturbations that upset
the temporal sequence of biochemical reactions during oocyte maturation (OM) and
predispose oocytes to aneuploidy. Nicotine is an alkaloid that has been reported
to disrupt the rate of OM, reduce ovulation and fertilization rates, and increase
diploidy. The objective of this study was to test the hypothesis that nicotine
perturbs the rate of OM and induces aneuploidy in mouse oocytes in vivo and in
vitro. Female mice were given 7.5 IU pregnant mare's serum and either 0, 5.0,
7.5, or 10 mg/kg nicotine in vivo at -3, 0, and +3 h relative to a 5 IU injection
of HCG. Oocytes were also cultured in vitro in the presence of 0, 1.0, 5.0, or
10.0 mmol/l nicotine. In vivo, significant (P < 0.05) differences in the
proportions of oocytes with premature centromere separation and premature
anaphase were found at 10.0 mg/kg nicotine suggesting that the rate of OM was
advanced. Also, at this dose the proportion of ovulated oocytes was reduced by
approximately 50% relative to controls. In vitro, only non-significant
differences were found among the parameters measured. Although nicotine reduced
the ovulation rate and perturbed the rate of OM in vivo, these data show that the
rate of aneuploidy was not significantly elevated.
PMID- 10694271
TI - Involvement of progesterone in gonadotrophin-induced pituitary adenylate cyclase
activating polypeptide gene expression in pre-ovulatory follicles of rat ovary.
AB - The present study was designed to determine whether progesterone might have a
role in gonadotrophin-induced pituitary adenylate cyclase-activating polypeptide
(Pacap) gene expression in rat ovary. Northern blot analysis revealed that
treatment of pregnant mare's serum gonadotrophin (PMSG)-primed immature rats with
the progestin antagonist RU486 or an inhibitor of 3beta-hydroxysteroid
dehydrogenase epostane, 1 h before HCG, resulted in a dose-dependent inhibition
of the HCG-induced Pacap gene expression. In-situ hybridization demonstrated that
the number of pre-ovulatory follicles expressing Pacap mRNA in their granulosa
cells was greatly reduced in ovaries treated with RU486. Moreover, the
suppressive effect of RU486 or epostane on the LH-induced Pacap gene expression
in cultured pre-ovulatory follicles was reversed by co-treatment with the
synthetic progestin R5020. We further cloned the 5'-flanking region of the rat
Pacap gene and identified the presence of a consensus progesterone receptor
element. When luciferase fusion genes containing Pacap gene promoter were
transiently transfected into granulosa cells of pre-ovulatory follicles,
luciferase activity was markedly stimulated by LH. Treatment with RU486 or
epostane resulted in partial suppression of LH-stimulated PACAP promoter
activity. Taken together, these results indicate that progesterone, acting
through progesterone receptors, plays a role in gonadotrophin induction of Pacap
gene expression in granulosa cells of pre-ovulatory follicles, and thereby may be
involved in the process of ovulation.
PMID- 10694272
TI - Effects of lipopolysaccharide and cytokines on production of RANTES by cultured
human endometrial stromal cells.
AB - RANTES (regulated upon activation, normal T cell expressed and secreted), which
is a potent chemoattractant for eosinophils, lymphocytes, and monocytes, was
recently detected in the human endometrium. The effects of modulators of
endometrial function, including lipopolysaccharide (LPS), tumour necrosis factor
(TNF)-alpha, interleukin (IL)-1beta, IL-4 and interferon-gamma (IFN-gamma), on
the production of RANTES by endometrial stromal cells (ESC) were examined by an
enzyme-linked immunosorbent assay and Northern blot analysis. The concentration
of RANTES in the culture media of non-stimulated ESC was below the level of
detection. The concentration of RANTES was increased by the addition of TNF
alpha, IL-1beta and LPS. IFN-gamma synergistically enhanced the TNF-alpha- and
LPS-induced RANTES expression, but had no effect on the IL-1beta-induced RANTES
expression. The TNF-alpha-induced production of RANTES by ESC was inhibited by IL
4. The transcription of RANTES in ESC was also stimulated by TNF-alpha, IL-1beta
and LPS in a dose-dependent manner. It is suggested that the LPS and cytokines
secreted by the maternal decidual tissue and the developing embryo may regulate
the production of RANTES by ESC. The modulation of RANTES concentration in the
local environment may contribute to the pathophysiological processes of human
reproduction by regulating the immunological reaction at the fetal-maternal
interface.
PMID- 10694273
TI - CD9 is expressed on human endometrial epithelial cells in association with
integrins alpha(6), alpha(3) and beta(1).
AB - Recently we reported that CD9 is involved in the invasion of a trophoblast-like
choriocarcinoma cell line, BeWo, probably through the regulation of integrin
functions. Integrins have also been reported to be expressed in the human
endometrium and it has been suggested that they play important roles in
blastocyst implantation. This study used immunohistochemistry to investigate the
expression of CD9 in the endometrium during the menstrual cycle. CD9 was found to
be intensely expressed on the cell surface of the glandular epithelium throughout
the menstrual cycle without any apparent differences in staining intensity. In
addition, Western blotting analysis of the affinity-purified proteins confirmed
that CD9 was associated with integrins beta(1), alpha(3) and alpha(6) in the
human endometrium. Therefore it can be concluded that CD9, in association with
integrins alpha(6), alpha(3) and beta(1), is a constitutive molecule of the
endometrial glandular epithelium. These results also suggest that CD9 may be an
important regulator of these integrins in the human endometrium.
PMID- 10694274
TI - Endometrial lysosomal enzyme activity in ovulatory dysfunctional uterine
bleeding, IUCD users and post-partum women.
AB - The aim of this study was to evaluate the role of lysosomal enzymes in
excessively heavy menstruation by comparing women with menorrhagia due to
dysfunctional bleeding or intrauterine contraceptive device (IUCD) use with those
with normal menstrual periods or with amenorrhoea associated with breastfeeding.
This was a prospective cohort investigation of the activity of four endometrial
lysosomal enzymes in three contrasting groups: (i) women with ovulatory
dysfunctional uterine bleeding and users of intrauterine contraceptive devices;
(ii) breastfeeding post-partum women in whom there are long periods of
amenorrhoea, particularly in the early months post-partum; and (iii) normal
cycling women. It was found that the total activity of lysosomal enzymes,
particularly acid phosphatase and N-acetyl-beta-D-glucosaminidase, was markedly
elevated (P < 0.001) in IUCD-exposed endometrium, and endometrium from women with
dysfunctional uterine bleeding when compared with endometrium from women with a
history of entirely normal menstrual periods or that in post-partum breastfeeding
women. The activity of alpha-L-fucosidase was moderately elevated in IUCD users
(P < 0.05) and ovulatory dysfunctional uterine bleeding (P < 0.05), whereas
alphaD-mannosidase activity was elevated in ovulatory dysfunctional uterine
bleeding (P < 0.05), but decreased in IUCD users (P < 0.01). No significant
differences were observed in the lysosomal enzyme activities of breastfeeding
post-partum women and normal cycling women. These results show that total
endometrial tissue activity of four lysosomal enzymes was substantially increased
throughout the cycle in most circumstances in women with two different causes for
increased menstrual bleeding. This suggests a contributory role to the increased
bleeding.
PMID- 10694275
TI - The progesterone receptor and ubiquitin are differentially regulated within the
endometrial glands of the natural and stimulated cycle.
AB - The initiation of human pregnancy requires precisely timed development of the
endometrium to receive the implanting blastocyst. The ovarian steroid hormones
are essential for development and maintenance of a hospitable uterine
environment. The hormonal regimes employed in assisted reproduction procedures
are known to alter the abundance of specific endometrial receptors for these
steroids. Since, in the presence of ligand, the progesterone receptor (PR) is
known to be modified by the small intracellular protein ubiquitin, we have
investigated the localization of ubiquitin and PR within the endometrial glands
of 28 fertile women during a monitored menstrual cycle and also during a
stimulated cycle prior to oocyte donation. We have also observed the number of
gland cells undergoing cell division as demonstrated by the presence of Ki67
immunostaining. We demonstrate that the percentage of ubiquitin-positive nuclei
increases from day four post-ovulation to day 10 post-ovulation in the natural
cycle, but that this increase is not seen during a stimulated cycle. The presence
of PR within glandular epithelium and the proliferation of gland cells were only
observed during the early secretory phase and did not appear to vary
significantly between the two cycles. We conclude that ubiquitin may play an
important role in endometrial development and that perturbation of ubiquitin may
be related to the lower implantation rate seen in the stimulated cycle.
PMID- 10694276
TI - Induction of an angiogenic phenotype in endometriotic stromal cell cultures by
interleukin-1beta.
AB - Activated peritoneal macrophages are associated with endometriosis and may play a
central role in its aetiology by releasing interleukin-1beta (IL-1beta) in
response to refluxed endometrium. Pari passu with the establishment of
endometriotic implants is the development of a vascular supply. In this study we
investigated the angiogenic properties of two endometrial proteins, vascular
endothelial growth factor (VEGF) and interleukin-6 (IL-6), and assessed their
production in response to IL-1beta stimulation in human stromal cells isolated
from normal endometrium (NE) and endometriotic lesions (EI). Proliferation of
bovine brain capillary endothelial cells (BBCE) with a [(3)H]-thymidine
incorporation assay was observed when VEGF (2.1 +/- 0.2-fold; P < 0.05) or VEGF
and IL-6 (1.8 +/- 0.1-fold; P < 0.05) were added in vitro, relative to saline
treated control cultures. Northern blot analysis showed induction of VEGF mRNA
(2.6-fold; P < 0.05) and IL-6 mRNA (6.3-fold; P < 0.05) transcripts in EI cells,
but not NE cells, exposed to IL-1beta. A similar induction was seen with VEGF and
IL-6 protein secretion in the responsive EI cells. Reverse transcription
polymerase chain reaction (RT-PCR) for the IL-1 receptor type I (IL-1 RI)
indicated that the differential effects of IL-1beta on NE and EI cells was
associated with 2.4 +/- 0.1-fold more receptor mRNA in EI versus NE cells. We
propose that the ability of IL-1beta to activate an angiogenic phenotype in EI
stromal cells but not in NE cells, is mediated by the IL-1 RI.
PMID- 10694277
TI - VEGF, its receptors and the tie receptors in recurrent miscarriage.
AB - The aetiology of recurrent miscarriage (at least three consecutive miscarriages)
usually remains unsolved. The vascular endothelial growth factor (VEGF) family of
proteins, together with their receptors and the Tie (tyrosine kinase with
immunoglobulin and epidermal growth factor homology domains) receptors, are
crucial for embryonic development. Therefore, we used immunohistochemistry to
analyse the expression of VEGF, the VEGF receptors (VEGFR)-1, -2, and -3, and the
Tie-1 and Tie-2 receptors in placental and decidual tissue of women with a
history of recurrent miscarriage and missed abortion (MA; n = 12) or blighted
ovum (BO; n = 6), and from normal early terminated pregnancies (n = 12). Compared
with controls, the MA and BO groups showed: (i) diminished placental
trophoblastic VEGF immunoreactivity; (ii) weaker VEGFR-1 and -2 immunoreactivity
in decidual vascular endothelium; (iii) reduced placental trophoblastic Tie-1
receptor immunoreactivity; and (iv) reduced decidual vascular endothelial Tie-1
and -2 receptor immunoreactivity. The absence of VEGFR-3 immunoreactivity in
decidual vascular endothelium was also noted in all study groups. Interestingly,
placental villi from the BO group presented blood vessel-like structures negative
for von Willebrand factor, but positive for VEGF, VEGFR-1, -2, -3, Tie-1 and Tie
2 receptor. We conclude that the expression of these antigens may be altered in
recurrent miscarriages.
PMID- 10694278
TI - Expression and localization of inducible nitric oxide synthase in human non
pregnant and early pregnant endometrium.
AB - The aim of the present study was to investigate the expression and distribution
patterns of inducible nitric oxide synthase (iNOS) in human non-pregnant and
early pregnant endometrium using Northern blot analysis, reverse transcription
polymerase chain reaction (RT-PCR) and immunohistochemistry. Northern blot
analysis revealed the expression of iNOS mRNA in human decidua and chorionic
villi in the first trimester but not in the endometrium at any stage of the
menstrual cycle. Nested RT-PCR, however, detected iNOS mRNA in human endometrium
at all stages of the menstrual cycle. Immunohistochemical staining of the
secretory endometrium using an anti-human iNOS polyclonal antibody revealed
labelling specifically concentrated in glandular epithelial cells. Staining was
absent in stromal cells. However, iNOS staining was positive in decidualized
stromal cells in tissues obtained in the first trimester of pregnancy.
Furthermore, extensive staining was observed in both syncytiotrophoblastic and
cytotrophoblastic cells. The finding of a large amount of iNOS mRNA at the feto
maternal interface throughout the first trimester of pregnancy suggests that iNOS
may play an important role in the maintenance of pregnancy.
PMID- 10694279
TI - Assessment of medical journal quality.
PMID- 10694280
TI - Osteonecrosis, corticosteroid use and Crohn's disease: evidence-based medicine
versus civil law.
PMID- 10694281
TI - Use of community resources before inflammatory bowel disease surgery is
associated with postsurgical quality of life.
AB - BACKGROUND: Research in chronic illness shows that community resources can have a
lasting influence on the course of the illness; however, little research has been
done to evaluate the community agencies that specifically address the needs of
inflammatory bowel disease (IBD) patients. OBJECTIVES: To survey awareness of
community agency resources among patients who have surgery for IBD, and to
analyze the association between using these resources and qualitative
postsurgical outcomes. SUBJECTS AND METHODS: Ninety-two subjects who had surgery
over a 12-month period completed, in full, the Inflammatory Bowel Disease
Questionnaire (IBDQ), and a self-report instrument used to probe awareness and
use of local community resources. Community resources were divided into two
groups: those involving primarily social and educational participation ('social/
educational') and those involving some individualized attention, usually from a
professional or trained lay facilitator ('professional/individual'). The
contribution of presurgical participation in each type of resource to
postsurgical quality of life was tested using ANOVA, with IBDQ score as the
dependent variable. The ANOVA was repeated with postsurgical disease activity as
a covariable. IBDQ subscale scores were compared between groups that were found
to differ in the ANOVA. RESULTS: Almost all subjects were aware of at least one
available resource. Participation in resources before surgery was variable, but
50% of the sample participated in at least one social/educational resource, and
46.9% participated in at least one professional/individual support. For the 92
subjects who completed both the IBDQ and the survey of resources, ANOVA revealed
a main effect of professional/individual resource use on postsurgical quality of
life but no main effect of social/educational resources and no interaction.
DISCUSSION: The association between presurgical participation in professional or
individualized community resources and better subjective outcome of IBD surgery
may be explained by a positive contribution of participation to coping with
surgery for IBD. The data do not support the alternative explanation that
subjects with less severe disease (and thus better outcome) have greater ability
to participate, although further research is required.
PMID- 10694282
TI - Applications of recombinant DNA technology in gastrointestinal medicine and
hepatology: basic paradigms of molecular cell biology. Part A: eukaryotic gene
structure and DNA replication.
AB - Progress in the basic sciences of cell and molecular biology has provided an
exciting dimension that has translated into clinically relevant information in
every medical subspecialty. Importantly, the application of recombinant DNA
technology has played a major role in unravelling the intricacies related to the
molecular pathophysiology of disease. This series of review articles constitutes
a framework for the integration of the database of new information into the core
knowledge base of concepts related to the pathogenesis of gastrointestinal
disorders and liver disease. The goal of this series of three articles is to
review the basic principles of eukaryotic gene expression. The first article
examines the role of DNA in directing the flow of genetic information in
eukaryotic cells.
PMID- 10694283
TI - Obscure gastrointestinal bleeding: an approach to management.
AB - Obscure gastrointestinal bleeding provides an uncommon but frustrating and
resource-intensive challenge for clinicians. Such patients hemorrhage recurrently
from sites within the gastrointestinal tract that are not detected by routine
endoscopy or radiography, and require a special diagnostic approach to localize
or exclude less common bleeding sources such as small bowel angioectasia or
neoplasia. The differential diagnosis of obscure gastrointestinal hemorrhage is
discussed, and the performance of available endoscopic, radiological and surgical
diagnostic tools including enteroscopy are examined critically. A stepwise
management algorithm that progresses from the history and physical examination to
surgical exploration is offered to facilitate early and efficient diagnosis.
PMID- 10694284
TI - HFE-associated hereditary hemochromatosis.
AB - Hereditary hemochromatosis is a common inherited disorder of the iron metabolism.
Screening studies indicate that it has a prevalence of one in 200 to 400,
depending on the population studied, and a carrier rate of about one in seven to
one in 10. Feder et al identified the hereditary hemochromatosis gene (HFE) in
1996 and two candidate mutations; the C282Y mutation has been shown to be
responsible for the majority of the hereditary hemochromatosis cases worldwide.
The gene discovery has led to rapid advances in the field of iron metabolism.
Although the basic defect is still not fully understood, much is known about the
sequence of events leading to iron overload. Hereditary hemochromatosis is a
major candidate for population screening and meets the screening criteria of the
World Health Organization, and Wilson and Jungner. It is one of the most
prevalent genetic diseases in white populations, and, importantly, early
diagnosis and simple effective treatment allow normal life expectancy. The
discovery of the HFE gene and the frequency of the single C282Y mutation as a
cause of most cases of hereditary hemochromatosis allow the possibility of
widespread genetic testing. However, the logistics, and the psychological and
social consequence of this, coupled with incomplete expression of the genotype,
necessitate further studies before population screening can be justified.
PMID- 10694285
TI - Benign pancreatic duct strictures: medical and endoscopic therapy.
AB - Pancreatic duct strictures usually reflect underlying pancreatic disease and are
likely caused by one or more of the following: acute or chronic pancreatitis,
benign or malignant pancreatic neoplasm, pseudocyst and trauma. The
characteristics of pancreatic strictures are identified, and medical and
endoscopic therapy options are reviewed.
PMID- 10694286
TI - Update on gastroesophageal reflux and respiratory disease in children.
AB - Pediatric respiratory diseases have been linked to gastroesophageal reflux
disease (GERD), but evidence regarding the association and its potential
mechanisms continues to accumulate, and important aspects remain to be
determined. Evidence for the association in two common pediatric respiratory
disorders - infantile apnea and asthma in older children - and difficult clinical
issues associated with the diagnosis and treatment of these two disorders are
reviewed. The provocative embryological and physiological connections between the
upper gastrointestinal tract and the respiratory tract, and recent understanding
of the compensatory anatomy and physiology that protect the normal individual
from respiratory manifestations of GERD are also explored. Dysfunctions of these
protections likely underlie the pathophysiology of these disorders.
PMID- 10694287
TI - Prevalence rates and an evaluation of reported risk factors for osteonecrosis
(avascular necrosis) in Crohn's disease.
AB - Avascular necrosis (osteonecrosis) occurs in Crohn's disease, but the rate of
this particular complication is not known. Over 20 years, 877 patients with
Crohn's disease, 492 women (56.1%) and 385 men (43.9%), were evaluated with
patient follow-up data available for a mean of 7.8 years. In this group, four men
were seen with osteonecrosis. No woman was affected. All patients had typical
radiological, magnetic resonance imaging or pathological changes of osteonecrosis
involving the femoral heads, while two also had superimposed avascular necrosis
involving the humeral heads. Patient ages ranged from 19 to 36 years at the time
of diagnosis of their Crohn's disease, and all were white. In one patient,
disease was confined to the colon, while three patients had disease involving the
terminal ileum and colon. Disease behaviour in two patients was classified as
penetrating because of concomitant ischiorectal abscesses, while one patient
developed a metastatic colon carcinoma. Ankylosing spondylitis was present in two
patients, but no other extraintestinal manifestations developed. Two patients
received corticosteroids as well as parenteral nutrition during the course of
their disease. Two patients did not receive corticosteroids or parenteral
nutrition. Of 877 patients with Crohn's disease, 484 (55. 1%) received
corticosteroids during the course of the disease, 196 (22.4%) received at least
one course of parenteral nutrition, and 125 (14.3%) received both corticosteroids
and parenteral nutrition. A total of 311 patients (35.5%) had at least one small
intestinal resection. The overall rate of avascular necrosis in Crohn's disease
was less than 0.5% but for men with Crohn's disease was about 1%. In this series,
risk of osteonecrosis could not be attributed to corticosteroid use, parenteral
nutrition or both forms of therapy administered together. Small intestinal
resection with loss of small intestinal absorptive area was not a risk factor for
the development of osteonecrosis. Avascular necrosis (or osteonecrosis) is a very
rare extraintestinal osseous complication that may occur in Crohn's disease,
independent of previously reported risk factors, including corticosteroids or
parenteral nutrition with lipid emulsions.
PMID- 10694288
TI - Taking action: implementing your written investment plan.
PMID- 10694289
TI - Founding of a new european dermatology organisation
PMID- 10694290
TI - The future of dermatology in Europe: position paper.
PMID- 10694291
TI - Coagulation factor XIII, endothelial damage and systemic sclerosis.
AB - In the blood coagulation process, Factor XIII (F XIII) is responsible for the
stabilization of the fibrin clot. The hypothesized ability of this blood
coagulation factor to affect collagen synthesis and degradation led to its use in
the treatment of scleroderma. However, the complex mechanism of action of F XIII
remains unclear. The aim of our study was to assess possible effects of F XIII on
endothelial damage, regarded as an early pathogenic event in systemic sclerosis
(SSc). Thus, we measured plasma levels of von Willebrand factor antigen (vWF:Ag),
a marker of endothelial cell injury, in 22 patients with SSc, 9 of whom were
treated with F XIII and 13 who do not receive the drug. The plasma concentration
of F XIII has also been analyzed. Interestingly, the vWF:Ag plasma levels within
the group of SSc patients treated with F XIII were significantly lower than those
of untreated SSc individuals (p < 0. 02). On the other hand, the highest mean
value of vWF:Ag was found in a subset of untreated subjects having SSc with
severe lung involvement, supporting a strict relationship between elevated levels
of vWF:Ag and severity of the disease. In contrast, plasma concentration of F
XIII resulted normal in all but 3 SSc patients, ruling out a deficiency of this
blood coagulation factor as promoting the occurrence of SSc. These preliminary
findings seem to support the hypothesis that F XIII may play an improving role on
endothelial damage, other than the initially suggested action on collagen
metabolism, in SSc.
PMID- 10694292
TI - An experience for ELISA for desmoglein 1, suggesting a possible diagnostic help
to determine the initial therapy for pemphigus foliaceus.
AB - Pemphigus foliaceus (PF) is an autoimmune skin disease in which loss of adhesion
between keratinocytes (i.e., acantholysis) in the granular cell layers appears to
be mediated by the binding of autoantibodies against desmoglein (Dsg) 1. Although
it has been suggested that the activity of the disease is rather correlated with
the titer of the antibody, there are still no precise studies on the
relationships between the disease activity and the titers of autoantibody against
Dsg1 by using ELISA. In this study, we performed ELISA using recombinant Dsg1
(rDsg1) as antigen on 8 patients with pemphigus foliaceus in order to examine the
reliability of this test for monitoring disease severity. The resultant index
values of ELISA, which were defined by the formula: (OD of tested serum - OD of
negative control)/(OD of positive control - OD of negative control) X 100, ranged
from 16 to 264 compared with 6.41 of cutoff index value for normal sera. A
patient with an index value of 213 had severe widespread erosions with erythema
and required pulse therapy of methylpredonisolone (1,000 mg/day for 3 days). A
patient with an index value of 111 had a moderate severity and was successfully
treated with an initial dose of 30 mg/day (0.64 mg/kg) of predonisolone. The
mildest patient with an index value of 16 was controlled with only topical
application of 0.05% betamethasone ointment twice a day. These results suggest
that ELISA index values for rDsg1 will provide a promising tool for monitoring
the disease severity and for determining the initial therapy for pemphigus
foliaceus.
PMID- 10694293
TI - Clinicopathological correlation of pigmented skin lesions using dermoscopy.
AB - Dermoscopy (dermatoscopy, epiluminescence microscopy) is an additional measure
for making the diagnosis of pigmented skin lesions more accurate. It enables the
clinician to visualize features not discernible by the naked eye. By applying
enhanced digital dermoscopy and a standardized gross pathology protocol to
pigmented skin lesions, a precise clinicopathological correlation of relevant
dermoscopic features can be made. Histological specimens of four pigmented skin
lesions (melanoma in situ, Clark's nevus, Reed's nevus, seborrheic keratosis)
were processed using a standardized gross pathology protocol and viewed along
with the clinical photographs and digital dermoscopic images that were magnified
and enhanced to better visualize the corresponding dermoscopic structures.
Furthermore, measurements of dermoscopic structures using digital equipment were
correlated with histometric findings. Our understanding of dermoscopic features,
especially the broadened pigment network - a specific dermoscopic criterion for
melanoma - was refined by this detailed case-by-case correlation. In addition,
some not yet fully characterized dermoscopic features, such as black lamella,
radial streaks, and exophytic papillary structures, were described in detail
dermoscopically and histopathologically. Moreover, measurements of these
dermoscopic features and the underlying histological structures were found to be
similar. Linking dermoscopy more closely with cutaneous pathology may help refine
the definitions and diagnostic criteria of pigmented skin lesions for
dermatologists as well as dermatopathologists.
PMID- 10694294
TI - High dose intravenous immunoglobulin (IVIG) in dermatomyositis: clinical
responses and effect on sIL-2R levels.
AB - An open study was conducted to identify and investigate dermatomyositis patients
who benefit from IVIG treatment, based on dermatological criteria, myositis
related symptoms and immune/inflammatory parameters. 19 patients (16 females and
three males, ages 31-84) suffered from dermatomyositis, and 4/19 patients had
paraneoplastic dermatomyositis. We monitored the disease activity by documenting
the clinical symptoms, recording muscle-related parameters (electromyography,
serum creatine kinase, histopathology), and by determining circulating
autoantibodies and serum levels of IL-6, sIL-2R, sTNF-a-R, sICAM-1, and sCD8.
7/19 patients responded to IVIG. They had severe skin but only moderate muscle
involvement, no autoantibodies, and no malignancy. IVIG-nonresponders had severe
skin and muscle disease, concomitant with autoantibodies and/or malignancy. sIL
2R levels were initially elevated in all patients but reverted to normal in IVIG
responders only. Creatine kinase-levels and other parameters did not correlate
with disease activity and/or treatment response. IVIG is effective in selected
dermatomyositis patients. sIL-2R serum levels appear to be useful predictors of
IVIG-induced treatment response and disease activity.
PMID- 10694295
TI - Recent physiopathological insights in cutaneous lymphocytic infiltrates
AB - As there were typing errors in the summary of the article by Herve Bachelez in
the EJD vol. 9, n 7, a corrected version is published below. The spectrum of
benign cutaneous lymphocytic infiltrates (CLI) includes a variety of entities
which are classified on the basis of clinicopathological findings, and of the
phenotype of the predominant lymphocytic subset among the skin infiltrate. Major
concern has been recently given to the clonality status of CLI by using highly
sensitive assays based on the PCR amplification of TCR/Ig loci. These studies
allowed the characterisation of clonal benign cutaneous lymphocytic expansions.
Other studies have shown evidence of oligoclonal patterns in HIV-associated CD8
cutaneous pseudolymphomas, and functional studies of the skin infiltrate further
showed that an antigen-driven mechanism was involved in the pathogenesis of this
latter entity. Finally, knowledge in the field of CLI has been improved by the
identification of antigens associated with skin-homing properties such as the so
called cutaneous lymphocyte-associated antigen (CLA) which is expressed at the
surface of most memory T cells infiltrating the dermis in inflammatory
conditions.
PMID- 10694296
TI - Acrogeria of the Gottron type in a mother and son.
AB - We report a familial case of acrogeria in a mother and son, with characteristic
cutaneous involvement and no clinical signs of vascular Ehlers-Danlos syndrome
(former EDS type IV) in spite of some tendency to bruising. The biochemical and
molecular studies did not disclose any abnormality of collagen type III, which
favours the diagnosis of acrogeria. It appears that recognition of acrogeria as
an entity is of clinical significance since these cases are not associated with
systemic involvement, and specifically with rupture of vessels and internal
organs, occasionnally occurring in EDS.
PMID- 10694297
TI - Correlation between bacterial population and axillary and plantar bromidrosis:
study of 30 patients.
AB - Although studies on the chemistry of odors are expanding to identify the chemical
structures of odorous substances, there are no universal standards as yet to
measure odor and intensity of bromidrosis. Clinical evaluation can be made on a
subjective scoring from 0 to 3 prior to prescription of an antiseptic soap. In
order to appreciate the correlation between the intensity of bromidrosis (BI) and
bacterial activity, a study was carried out with both clinical and bacterial
assessment in thirty patients with axillary or plantar BI. Odor intensity was
evaluated by two physicians using a score from 0 to 3 (i.e. absent, minor,
moderate, major), meanwhile bacterial composition and density were assessed
before and after 10 days of hygiene using an antiseptic detergent
(trichlocarbanilide) provided on the first visit. Baseline count of
diphtheroids/cm2 was 35.104 and baseline micrococci average was 32.104/cm2. At
the end of the study, the reduction of odor intensity was observed in 20 patients
(67%) without any change in sweat production. The clinical improvement correlated
with a reduction of both micrococci (70%) or diphtheroids (73%) as compared with
initial data. In patients presenting persistant bromidrosis, the bacterial
count/cm2 did not significantly decrease and remained above 104 diphtheroids/cm2.
Thus, this study suggests that body odor may be at least indirectly correlated to
microbia counts with a bacteria threshold of BI ranging around and above 104.
PMID- 10694298
TI - Occurrence of Hodgkin's disease and cutaneous B-cell lymphoma in the same
patient: a report of two cases.
AB - The occurrence of Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) in the
same patient is well known. The most frequent observation has been the
development of large B cell lymphoma in patients affected with the nodular form
of lymphocytic predominant HD. A less common situation is the development of NHL
among patients successfully treated for HD. In such patients the second lymphoma
has been thought to be related to the previous therapy or the immunodeficiency
state that can accompany HD. Histologically, these NHL lymphomas often are
intermediate to high grade and frequently extranodal. We report two patients
successfully treated for HD who also developed NHL of the skin. Both patients
presented with strikingly similar findings regarding to sex, age and subtype of
HD. Clinical, histopathological and immunophenotypical findings were consistent
with cutaneous low-grade B cell lymphoma of the marginal zone type. Both cases
remain in complete remission of HD after standard therapy. In both patients the
cutaneous lymphoma followed an indolent clinical course after a long follow-up
period. This observation expands the spectrum of alterations possibly related to
HD.
PMID- 10694299
TI - Pulmonary nocardiosis with cutaneous involvement mimicking a metastasizing lung
carcinoma in a patient with chronic myelogenous leukaemia.
AB - We report a unique case of a man suffering from chronic myelogenous leukaemia who
presented with clinical symptoms, X-ray, and bronchoscopical findings consistant
with a bronchopulmonary space-occupying process which was suspected to be a
central lung carcinoma as a secondary de novo malignancy. In addition, the
patient developed several subcutaneous nodular livid red lesions on the left
forearm which were considered to be cutaneous metastases of the presumptive lung
malignancy. Treatment was started with percutaneous radiation of the mediastinum
over a period of ten days with a total dose of 25 Gray. The patient died from
circulatory and respiratory failure. Only post mortem pathological examination
was indicative of a nocardiosis of the lungs with haematological spread to
eosophagus, pleura, and subcutaneous skin of the left forearm. Unfortunately,
diagnosis of nocardiosis could not finally proven by culture or molecular
biological methods. A lung carcinoma or an infiltrate of residual or relapsing
chronic myelogenous leukemia in the lung could be definitely ruled out.
PMID- 10694301
TI - Raynaud's phenomenon possibly induced by a compund drug of tegafur and uracil.
AB - We describe a 50-year-old woman who noted acral hyperpigmentation, sclerodactyly
and Raynaud's phenomenon with 1:160 of antinuclear antibody titer after treatment
with a compound drug with tegafur and uracil. Histological findings of the finger
and palm included hyperkeratosis, vacuolar degeneration of basal cells, thickened
collagen fibers in the dermis, and dilatation of capillary vessels, perivascular
mononuclear cell infiltration and melanophages in the upper dermis. IgG, IgA,
IgM, C3 and C1q were not deposited in the skin by direct immunofluorescence
study. After cessation of the drug, Raynaud's phenomenon and hyperpigmentation
disappeared within 1 month and 4 months, respectively, and antinuclear antibody
turned negative within 4 months. These observations suggest that tegafur may have
caused not only hyperpigmentation in the palms and soles, but also sclerodactyly
and Raynaud's phenomenon in the present case.
PMID- 10694300
TI - Tumoral calcinosis: a case report with an electron microscopic study.
AB - A 68-year-old woman developed large subcutaneous masses on her abdomen and thighs
after a bruise sustained in a traffic accident. She had severe pain when sitting
up straight. Histological examination revealed calcified tissues in the entire
dermis of the injured areas. On electron microscopy, crystalline materials were
observed in the dermis, which seemed to be formed by the deposition of
hydroxyapatite on unusual proteoglycan. In a vessel wall, a thick, layered
basement membrane was observed. This suggests that vascular injury and subsequent
hypoxia play a role in the process of calcinosis. We performed a partial
resection with good results in alleviating the patient's pain.
PMID- 10694302
TI - Treatment of pruritus of reactive perforating collagenosis using transcutaneous
electrical nerve stimulation.
AB - Reactive perforating collagenosis is a form of perforating dermatosis due to
transepithelial elimination of collagen and characterized by itchy papulonodular
eruptions frequently seen in patients with diabetes mellitus and end stage renal
failure. Pruritus is often severe and treatment is difficult. Two adult Chinese
diabetic patients with acquired reactive perforating collagenosis unresponsive to
topical therapies and oral antihistamines, were treated with transcutaneous
electrical nerve stimulation. There was a significant reduction of itch followed
by gradual resolution of the skin lesions.
PMID- 10694303
TI - Understanding the trends in melanoma incidence and mortality: where do we stand?
AB - In previous decades melanoma incidence rates have risen spectacularly in white
populations worldwide and a parallel - although more moderate - increase has been
observed for melanoma mortality. More recently several reports have been made of
a stabilization or decrease of mortality rates in the younger birth cohorts,
resulting in a stabilization in the overall mortality in the 1980s for some
populations. This article reviews past and current trends in melanoma
epidemiology. It further handles the possible explanations for these trends and
the currently available indications for or against these trends being brought
about by real or artefactual influences. Time will undoubtedly reveal more about
the truth.
PMID- 10694304
TI - Nerve growth factor and keratinocytes: a role in psoriasis.
AB - Nerve growth factor (NGF) is synthesized and released by human keratinocytes. NGF
acts as a neurotrophic molecule at the skin level, as it stimulates the sprouting
of nerve fibers and regulates the synthesis and expression of neuropeptides. NGF
can thus take part in neurogenic inflammation which in turn is involved in the
pathogenesis of several inflammatory dermatoses. Human keratinocytes also
synthesize and express the low (p75)-and the high-affinity (trk) NGF-receptor
(NGF-R). NGF stimulates keratinocyte proliferation which is blocked by the
natural alcaloid K252, a specific inhibitor of trk phosphorylation. K252 inhibits
keratinocyte proliferation and induces keratinocyte apoptosis, in the absence of
exogenous NGF, indicating the existence of an autocrine loop where NGF and trk
act as key players. Finally, NGF protein levels are increased in psoriatic as
compared to non-lesional and normal skin, and psoriatic keratinocytes express
higher amounts of NGF than normal keratinocytes. This review will discuss the
above findings in view of a possible involvement of NGF in the pathomechanisms
associated with the development of the psoriatic lesion.
PMID- 10694305
TI - Pili torti and sensorineural hearing loss. A follow-up of Bjornstad's original
patients and a review of the literature.
AB - In 1965, Bjornstad described 8 patients with pili torti, of whom five also
suffered from hearing loss. The combination of these two findings was later
coined Bjornstad's syndrome. Typically, these patients develop hair loss in the
first two years of life, while the hearing deficit may become evident in the
first three to four years of life. However, considerable differences regarding
age of onset and clinical severity have been reported, a pronounced hair shaft
abnormality is often associated with severe hearing deficits. In a recent study
of a Mexican family with pili torti and deafness, the inheritance was determined
to be autosomal recessive, and mapped to the gene locus 2q34-q36. Hypogonadism
and mental retardation are associated findings that have been described in
patients with Bjornstad syndrome. In this re-investigation of Bjornstad's
original patients, two additional patients with pili torti and hearing loss are
described, and a review of the published cases of Bjornstad's syndrome is given,
as well as a short overview of syndromes and conditions with twisted hairs.
PMID- 10694306
TI - Atrichia, ichthyosis, follicular hyperkeratosis, chronic candidiasis, keratitis,
seizures, mental retardation and inguinal hernia: a severe manifestation of IFAP
syndrome?
AB - A boy with congenital atrichia, ichthyosis follicular, keratitis, cutaneous
infections and a huge inguinal hernia, but without deafness is reported. We
believe it represents a new case of a rare X-linked recessive syndrome known as
ichthyosis follicularis, alopecia, photophobia syndrome (IFAP). The differential
diagnosis from keratitis ichthyosis deafness is discussed. The cutaneous
infections seen in our case suggest the possibility of considering a genetic link
between these syndromes.
PMID- 10694307
TI - Temporary hair loss using the long-pulsed alexandrite laser at 20 milliseconds.
AB - Facial hypertrichosis presents an enormous psychological burden for women.
Temporary hair removal (waxing, plucking, etc.) and electrolysis are prolonged
and unsatisfactory methods of treatment. For a few years several laser systems
with varying wavelengths, pulse durations and energy fluences have been used
successfully in laser epilation. In the retrospective study on hand, we report on
results of 30 female patients with hypertrichosis in the facial area treated with
the long pulse alexandrite laser at 20 msec (Cynosure PhotoGenica LPIR/Apogee;
755 nm; 20 msec; up to 30 J/cm2; 10 or 12.5 mm beam diameter) over an 18 month
treatment period. After an average of 8 treatments, an average clearance rate of
75% could be achieved. Fair hair (white/blond/red) only showed a clearance rate
of 10%. Hypo- and hyperpigmentation did not appear. The most frequent adverse
effects were the occasional appearance of scattered crusting (17%), which healed
without consequences, and folliculitis (13%). The average post-treatment
observation time lasted 3.25 months. The long-pulsed alexandrite laser at a pulse
duration of 20 msec is an effective and safe method of treatment of
hypertrichosis in the facial region of women. Black hair responds considerably
better to the laser treatment than fair hair. A longer post-treatment observation
time is necessary, though, in order to provide evidence for the permanence of the
success of the method.
PMID- 10694308
TI - Comparative study between terbinafine 1% emulsion-gel versus ketoconazole 2%
cream in tinea cruris and tinea corporis.
AB - An open, prospective, comparative, randomised and parallel-group study of 65
patients was conducted to evaluate the efficacy and safety of topical 1 %
emulsion-gel of terbinafine versus 2% ketoconazole cream in the treatment of
tinea corporis and tinea cruris. Treatment for terbinafine emulsion-gel was
applied once daily for 1 week, whereas ketoconazole cream was applied once daily
for 2 weeks; patients were followed for 2 weeks. Thirty-three patients in the
terbinafine group and 32 in the ketoconazole group were evaluated for efficacy
and safety. At the end of the study, rates of mycological cure were 94% for
terbinafine emulsion-gel and 69% for ketoconazole cream (p = 0.027). A clinical
and mycological overall evaluation was obtained for 72% of patients receiving
terbinafine emulsion gel and 31% of patients receiving ketoconazole cream (p =
0.002). A total of four patients (1 in the terbinafine group and 3 in the
ketoconazole group) had contact dermatitis-like side effects. We conclude that a
1-week course of terbinafine 1% emulsion-gel is significantly more effective than
ketoconazole 2% cream in the treatment of tinea corporis and tinea cruris as
regards clinical and mycological cure and treatment safety.
PMID- 10694309
TI - Reproducibility of a dermoscopic method (7FFM) for the diagnosis of malignant
melanoma.
AB - Dermoscopy improves sensitivity in the diagnosis of melanoma. We have developed a
new diagnostic dermoscopic method which evaluates only seven dermoscopic features
or criteria. We called the method Seven features for melanoma (7FFM). To present
and to evaluate the reproducibility of our dermoscopic diagnostic method (7FFM)
we held eight dermoscopic courses from 10/4/96 to 04/03/98 in various Italian
cities. In fact the reliability of a diagnostic test or method mainly depends on
the level of agreement in the interpretation of results among different
observers. Only methods with good agreement can be used in clinical practice for
the diagnosis of melanoma. Many dermatologists (207) attended one of the eight
dermoscopic courses: each course was one-day in length and at the end of the
course the participants evaluated a set of 25 dermoscopic slides using our
dermoscopic method. Percentages of concordance and K values for a kappa
statistical analysis to evaluate inter-rater reliability have been calculated.
The method showed a mean percentage of concordance of 85.7%, median 88%, a mean K
value of 0.699, median 0.684. These data point to a good agreement level. Our
method shows good reproducibility after a short training program.
PMID- 10694310
TI - Different interaction of mast cells with human endothelial cells and fibroblasts.
AB - In a number of chronic inflammatory conditions resulting in fibrosis,
perivascular mononuclear cell infiltration including mast cells (MC) has been
shown before the onset of vascular injury and interstitial fibrosis. These
observations suggest a role for MC in inducing endothelial cell (EC) injury and
fibroblast (FB) proliferation and collagen synthesis. In view of these
observations, the interactions of MC with EC and FB were studied. MC adhesion to
EC and FB showed time-dependent increase reaching a plateau at 1 and 3 hrs,
respectively. With added MC, the proliferation of EC showed a dose-dependent
decrease, but that of FB, a dose-dependent increase. MC, MC surpernatant and
sonicated MC induced dose-dependent cytotoxic activity to EC, whose cytotoxicy
was inhibited by trypsin inhibitor. FB cocultured with MC showed 9.95 times
collagen synthesis and 11.0 times protein synthesis compared with FB without MC.
These results showed that 1) MC attached to EC inhibited the proliferation by
cytotoxic activity to EC, which was due to a kind of proteolytic enzyme involving
trypsin, 2) MC had proliferative and collagen synthetic activity to FB. These
results suggest the possibility that MC have a role in a number of chronic
inflammatory diseases resulting in vascular injury and interstitial fibrosis.
PMID- 10694311
TI - The effects of hair loss in European men: a survey in four countries.
AB - Despite the high prevalence and the accepted psychological aspects of male
pattern hair loss, few have characterized the effects of hair loss in
representative samples of men in different countries. A representative sample of
households in 4 European countries (France, Germany, Italy and the United
Kingdom) was contacted by an interviewer and resident males 18-40 years of age (n
= 1,717) completed a questionnaire designed specifically to evaluate attitudes to
hair loss. The questionnaire was comprised of 78 questions translated and pilot
tested using standard methodology into each local language. Questionnaires
queried about self-rated hair loss, satisfaction with hair appearance,
noticeability of hair loss to others, and bother, concerns and perceptions about
hair loss, as well as general physical health (the SF-12 questionnaire) plus
three additional questions about mental health. The self-reported degree of hair
loss in men was statistically significantly associated (p < 0.001) with all hair
loss specific effects measured, except "limiting job opportunities". The impact
of hair loss was generally consistent in the four countries surveyed, although
less pronounced in the United Kingdom. Age was significantly correlated with hair
loss (rs = 0.34, p < 0.001). Men with greater hair loss were more bothered, more
concerned about looking older due to their hair loss, and less satisfied with
their hair appearance. Male pattern hair loss has significant negative effects on
hair-loss specific measures in men 18 to 40 years of age in France, Italy,
Germany and the UK. The degree that hair loss is perceived as noticeable to
others appears to be a significant contributor to these negative effects.
PMID- 10694312
TI - Epidemiology of occupational contact dermatitis in a North Italian population.
AB - Occupational contact dermatitis (OCD) is a very important skin disease both for
its high frequency and for its social and economic implications. The aim of our
work is to evaluate the epidemiology of occupational contact dermatitis in a
north-Italian population and the possibility of a correct etiological diagnosis
using the patch test standard series of GIRDCA (Italian Group of Resarch on
Contact Dermatitis). We patch tested 1,565 out-patients affected by dermatitis
with standard series GIRDCA and with other specific professional haptens. The
manifestations were suspected of being of occupational origin by a dermatologist
on the basis of clinical and anamnestic data. Of all the recorded professions we
have considered only the more numerically significant: food industry, building
industry, textile industry, employees, cleaners, hospital personnel,
hairdressers, housewives, mechanics and metallurgists. Sixty-nine percent of
contact dermatitis was found in women, the hairdressers had the greatest number
of patients in the younger group (68.7% in the 11-20 years age group) and the
textile industry workers in older group (100% in the 41-50 years age group). A
positive allergological anamnesis emerged in 32.3% of allergic contact
dermatitis. Irritant contact dermatitis (10.6%) was more frequent than allergic
contact dermatitis (8.4%). The hands are the most common localization (94. 4%).
The allergen with the highest frequency of positive reactions is p
phenylenediamine (25.3%). We discuss the frequency of positives to various groups
of allergens in each profession and the principal means of contact. Because of
the frequency of this type of occupational skin disease, we stress the importance
of prevention. The standard series GIRDCA was found to be adequate for
recognizing occupational contact dermatitis in most of our patients (74%).
PMID- 10694313
TI - Clinical evolution of alopecia areata with a male androgenetic alopecia pattern
to sisaipho.
AB - We report the case of a 16-year-old boy who developed an advanced alopecia areata
(AA) type male androgenetic alopecia (MAGA). In 6 months he lost his frontal hair
line and showed a sisaipho pattern of alopecia. It probably represents a rare
evolution of AA in a wave-like form.
PMID- 10694314
TI - Grzybowski's generalized eruptive keratocanthomas: a case report.
AB - A 47-year old woman with Grzybowski's generalised eruptive keratoacanthomas is
described. There was no history of skin disease in her family, except for an
uncle's basal cell carcinoma. From 1995 she developed multiple lesions of various
size, ranging from hundreds of small follicular lesions to large typical
keratoacanthomas up to 5 cm in diameter, scleroderma-like facial skin and marked
ectropion. Histological examination of small and large skin lesions was typical
of keratoacanthoma, and no human papillomavirus was detected by polymerase chain
reaction. Oral treatment with acitretin had no effect. Both cyclophosphamide and
methotrexate therapy were refused by the patient despite the progressive course
of the disease. Blepharoplastic surgery had some effect on eye symptoms. The
etiology of this rare disease is unknown, but is probably related to some genetic
defect.
PMID- 10694315
TI - Extensive haemorrhagic-bullous skin manifestation of systemic AA-amyloidosis
associated with IgGlambda-myeloma.
AB - In an 86-year-old woman with a multiple myeloma of the IgG lambda subtype a
coinciding systemic amyloidosis manifested as a macroglossia, diffuse alopecia
and generalized cutaneous involvement. The skin was affected by milium-like
papules, petechial haemorrhages and an increased tissue fragility with subsequent
blister formation. The typical histology and immunohistology pattern revealed
large intradermal amyloid masses, reacting positively with anti-amyloid A
antibodies, which surrounded cuff-like dilatated blood capillaries. The abundance
of these amyloid deposits led to significant deflexibilization and fragility of
the capillaries and the dermal matrix eventually resulting in the haemorrhagic
bullous eruptions. The peculiar feature of the present case is the intensity of
bullous-haemorrhagic skin damage due to amyloid A deposition without any
detection of cutaneous IgGl as the myeloma-derived paraprotein assumed to be
causative for the development of systemic AA amyloidosis.
PMID- 10694316
TI - Early detection of lymph node metastases by 7.5 MHz-ultrasound examination in a
patient with primary malignant melanoma of the lung.
AB - Primary malignant melanoma of the lung (PMML) is a rare neoplasm that may be
misdiagnosed as one of the more common types of lung cancer. Most cases are
characterized by a very poor prognosis, ultimately leading to the patient's
death. Since an optimal systemic treatment schedule is not established so far,
early detection of lymph node metastases may be important for surgical
interventions. We report on a 55-year-old male patient with a primary bronchial
malignant melanoma of his left lower lobe that was treated by pneumonectomy. 11
and 17 months after removal of the PMML, suspicious lymph nodes in the patient's
left axilla were identified by 7.5 MHz-ultrasound examinations. Again surgical
treatment was performed and histopathology showed lymph node metastases of
malignant melanoma. During adjuvant therapy with interferon alpha (3 x 6 Mio IE
per week) no further relapse has been observed with a follow-up of 8 months after
the last operation. An overview of primary melanoma of the lung is given and
diagnostic options are discussed. The 7.5 MHz-ultrasound examination appears to
be especially helpful in the early detection of lymph node metastases leading to
early initiation of surgical treatment possibly associated with a prolonged
survival in our patient.
PMID- 10694317
TI - Nail alterations secondary to pactitaxel [corrected] therapy.
AB - Docetaxel and pactitaxel [corrected] are the main drugs pertaining to the taxanes
family. Nail alterations associated with docetaxel therapy are not a rare event,
but they have rarely been reported secondary to paclitaxel therapy, probably
because of its more recent use. We present two cases of onycholysis and nail
discoloration secondary to paclitaxel therapy.
PMID- 10694318
TI - A case of persistent light reaction phenomenon to ketoprofen?
PMID- 10694320
TI - European Dermatology Forum Reporter June 1999 including highlights of the second
general meeting...
PMID- 10694319
TI - The use of systemic antimycotics in dermatotherapy.
AB - Fungal infections of the skin as well as of the nails and hair due to
dermatophytes or due to yeasts or moulds still form a major portion of skin
diseases overall. Effective therapy of mycoses is not always simple to achieve.
In less severe cases topical therapy can be sufficient, but in extensive
cutaneous infections, previous resistance to treatment and especially
hyperkeratotic tinea and onychomycosis, systemic therapy can be mandatory. For
systemic therapy, in particular azoles, i.e. itraconazole and fluconazole as well
as the allylamine terbinafine are worth considering. The older antimycotics, i.e.
griseofulvin and also ketoconazole are more and more replaced by other, newer
drugs. For optimal treatment of a given mycosis, therapy can and should
correspond to the individual situation. This applies both to the type of drug and
its mode of application. The treatment of choice is the one with the best benefit
to risk ratio and the best benefit to cost ratio. Unfortunately, as yet, a cure
cannot be expected in every single case.
PMID- 10694321
TI - Papillomavirus detection: demographic and behavioral characteristics influencing
the identification of cervical disease.
AB - OBJECTIVE: This study was undertaken to assess the association between detection
of high-risk types of human papillomavirus and various demographic and behavioral
characteristics and to further relate this association to cervical
histopathologic findings. STUDY DESIGN: A total of 1007 patients with a
Papanicolaou test result reported as high-grade squamous intraepithelial lesion
or with 2 results reported as atypical squamous cells of undetermined
significance or low-grade squamous intraepithelial lesion were referred from city
and county clinics to a colposcopic clinic. All women had a cervical smear
obtained, underwent colposcopically directed biopsy and endocervical curettage,
and had a specimen taken for human papillomavirus deoxyribonucleic acid detection
by polymerase chain reaction. Demographic information was obtained from each
patient. RESULTS: Human papillomavirus deoxyribonucleic acid was identified in
655 (66%) of the specimens. High-risk human papillomavirus types (16, 18, 31, 33,
and 35) were detected in 463 (70.7%) of these specimens. The prevalence of
evidence of human papillomavirus (koilocytosis) and grade 1 cervical
intraepithelial neoplasia in the biopsy specimen decreased significantly with
age, whereas the prevalence of grade 2 or 3 cervical intraepithelial neoplasia in
the biopsy specimen increased with age. There was a significant age-dependent
decreasing trend in detection of high-risk human papillomavirus deoxyribonucleic
acid among women who had human papillomavirus-associated changes, grade 1
cervical intraepithelial neoplasia, and grade 2 or 3 cervical intraepithelial
neoplasia in the biopsy specimen. The prevalences of high-risk human
papillomavirus among patients with grade 1 cervical intraepithelial neoplasia and
grade 2 or 3 cervical intraepithelial neoplasia were similar, and both were
significantly higher than among women with no evidence of cervical
intraepithelial neoplasia or koilocytosis in the biopsy specimen. Risk factors
associated with grade 2 or 3 cervical intraepithelial neoplasia were different
from those associated with human papillomavirus-associated changes and with grade
1 cervical intraepithelial neoplasia. CONCLUSION: The detection of high-risk
human papillomavirus was age-dependent for all histologic categories. Patients
with grade 2 or 3 cervical intraepithelial neoplasia had a prevalence of high
risk human papillomavirus that was similar to that among women with grade 1
cervical intraepithelial neoplasia but significantly higher than that among women
whose biopsy specimens appeared normal or demonstrated only the presence of human
papillomavirus-induced changes (koilocytosis). This suggests that separation of
human papillomavirus-associated changes only from grade 1 cervical
intraepithelial neoplasia may be of significance in tissue diagnosis.
PMID- 10694323
TI - Adherence to postmenopausal hormone therapy during the year after the initial
prescription: A population-based study.
AB - OBJECTIVE: In randomized trials a higher proportion of women prescribed
continuous combined hormone replacement therapy complete the full course of
treatment compared with those prescribed sequential therapy. We sought to
determine adherence to hormone therapy in a less-selected population. STUDY
DESIGN: Women enrolled in a prepaid health plan participated in a telephone
interview 12 to 15 months after newly initiating use of hormone replacement
therapy. The interview elicited information on whether the women were still
taking the hormones as first prescribed and reasons for switching or
discontinuation. A computerized pharmacy database was used to determine initial
doses, prescription renewal, and dates of switching or discontinuation. RESULTS:
The proportion continuing the originally prescribed hormone regimen at 1 year was
higher among continuous combined therapy users (68.9%, 62/90) than among
sequential therapy users (54.4%, 62/114). Women who initiated continuous combined
therapy were less likely to have switched regimens (10.0%) than were sequential
users (20.2%; relative risk, 0.5; 95% confidence interval, 0.2-1.0) but only
somewhat less likely to have discontinued use (21.2% vs 25.4%; relative risk,
0.7; 95% confidence interval, 0.4-1.3). Examined as a whole, women prescribed
continuous combined therapy were less likely than those prescribed sequential
therapy to quit or switch during the first year (relative risk, 0.6; 95%
confidence interval, 0.4-1.0). CONCLUSION: Although adherence was higher among
women prescribed continuous combined hormone replacement therapy than sequential
therapy, the high level of nonadherence in both groups suggests room for
improvement of menopausal therapies so that women find them acceptable for
sustained use.
PMID- 10694322
TI - Oral contraceptives and bone mineral density: A population-based study.
AB - OBJECTIVE: We sought to test the hypothesis that exposure to oral contraceptives
protects the skeleton. STUDY DESIGN: Multiple regression techniques were used to
analyze data for a random sample of 710 Australian women (age range, 20-69
years). Bone mineral density was measured at the lumbar spine, proximal femur,
whole body, and distal forearm. Oral contraceptive exposure was assessed by a
questionnaire. RESULTS: Women exposed to oral contraceptives had a 3.3% greater
mean bone mineral density adjusted for body mass index and age at the lumbar
spine (partial r (2) = 0.009; P =.014). Adjusted mean vertebral bone mineral
density was 3.3% greater for premenopausal women (partial r (2) = 0.008; P <.05),
but the effect did not reach significance among postmenopausal women. Higher bone
mineral density was associated with increased duration of exposure, with a mean
increase of 3.2% associated with the first 5 years and a further 0.2% with >/=5
years of exposure. No association was detected at other sites. CONCLUSION:
Exposure to oral contraceptives may be associated with higher lumbar spine bone
mineral density.
PMID- 10694324
TI - Modulation of the sleep electroencephalogram by estrogen replacement in
postmenopausal women.
AB - OBJECTIVE: We performed an examination of the effects of estrogen replacement on
the sleep electroencephalogram in postmenopausal women. STUDY DESIGN: A sleep
electroencephalogram was recorded in 11 postmenopausal women with and without
estrogen administered by skin patch (50 microg of estradiol per day). RESULTS:
Estrogen enhanced rapid-eye-movement sleep (50 +/- 4 vs 39 +/- 5 minutes, P <.05)
and reduced time awake (12 +/- 5 vs 20 +/- 6 minutes, P <.05) during the first 2
sleep cycles. The normal decrease in slow-wave sleep and delta activity from the
first to the second cycle (in percentage from the first cycle) was restored by
estrogen (-56% +/- 9% vs -5% +/- 14% and -20% +/- 6% vs -2% +/- 5%; P <.05,
respectively). Sigma electroencephalographic activity was increased by estrogen
from the first to the second half of the night but decreased during baseline.
CONCLUSION: Estrogen treatment after menopause can help to restore the normal
sleep electroencephalogram pattern, which in turn might contribute to improved
cognitive functioning.
PMID- 10694325
TI - Interleukin 1 receptor antagonist gene polymorphism in women with vulvar
vestibulitis.
AB - OBJECTIVE: Vulvar vestibulitis is a chronic inflammatory syndrome of unknown
cause and pathogenesis. We examined the relation between vulvar vestibulitis and
polymorphisms in the gene coding for the interleukin 1 receptor antagonist, a
naturally occurring down-regulator of proinflammatory immune responses. STUDY
DESIGN: Cells from the lower genital tract of 68 women with vulvar vestibulitis,
343 women with no history of vulvodynia, and 40 women with human papillomavirus
cervical infection were tested by polymerase chain reaction for the different
alleles of the gene encoding for interleukin 1 receptor antagonist. The presence
of human papillomavirus in the specimens was determined by polymerase chain
reaction with the use of degenerate consensus primers to the conserved L1 gene.
RESULTS: Allele 2 of the gene encoding the interleukin 1 receptor antagonist was
present in homozygous form in 52.9% of women with vulvar vestibulitis. In marked
contrast only 8. 5% of the control women and 2.5% of women with human
papillomavirus were homozygous for this allele (P =.0001). Among the women with
vulvar vestibulitis, 57.5% of those without human papillomavirus, as well as
52.2% of those with human papillomavirus, were homozygous for allele 2 of the
gene encoding interleukin 1 receptor antagonist. CONCLUSION: The unique
distribution of interleukin 1 receptor antagonist alleles among women with vulvar
vestibulitis suggests that polymorphism in this gene may be a factor influencing
susceptibility to this syndrome, severity of symptoms, or both.
PMID- 10694326
TI - Expression of brx proto-oncogene in normal ovary and in epithelial ovarian
neoplasms.
AB - OBJECTIVE: We previously identified a protein, Brx, that interacted with estrogen
receptor alpha. Sequence analysis determined that Brx is a novel member of the
Dbl family of oncoproteins involved in signaling pathways that regulate cell
growth. Because the Brx protein was found to be highly expressed in
hormoneresponsive breast epithelium, the objective of this study was to determine
whether Brx was expressed in both normal and neoplastic ovarian tissues. STUDY
DESIGN: A polyclonal antiserum directed against the Brx protein was used to
perform immunolocalization on sections from 5 normal ovaries and 20 ovarian
neoplasms. Chromosomal localization of the brx gene was accomplished by means of
fluorescence in situ hybridization. Northern and Western blot analyses were
performed on extracts prepared from human ovaries. RESULTS: Brx protein was
localized to the cytoplasm of granulosa cells from mature graafian follicles, the
corpus luteum, and islands of hilar cells in normal ovaries. In tumors with low
malignant potential and ovarian carcinomas the neoplastic epithelium stained
strongly for Brx protein. Northern and Western blot analyses, respectively,
confirmed expression of Brx messenger ribonucleic acid and protein in normal
ovary. Finally, the brx gene was localized to 15q25. CONCLUSION: The proto
oncogene brx is expressed in specific normal human ovarian tissues and is also
present in ovarian epithelial neoplasms.
PMID- 10694327
TI - Effect of fluoxetine on contractile activity of pregnant rat uterine rings.
AB - OBJECTIVE: We sought to compare the effects of fluoxetine, imipramine, and
nortriptyline on spontaneous and serotonin-activated contractile activity of the
uterine rings from midterm and term pregnant rats. STUDY DESIGN: Uterine rings
from timed-pregnant Sprague-Dawley rats on day 14 (midgestation) and day 22 (term
gestation) were used for isometric tension recording. Responses to cumulative
concentrations of fluoxetine, imipramine, nortriptyline, and serotonin in the
absence and presence of the monoamine reuptake inhibitors were studied. RESULTS:
Neither of the monoamine reuptake inhibitors significantly influenced spontaneous
contractile activity, whereas the concentration-dependent increase in activity
induced by serotonin was inhibited in rings from both midterm and term pregnant
rats. CONCLUSIONS: The reported increase in preterm delivery in women receiving
fluoxetine during the third trimester cannot be explained by a direct effect on
uterine contractility.
PMID- 10694328
TI - Effects of pregnancy and exercise on concentrations of the metabolic markers
tumor necrosis factor alpha and leptin.
AB - OBJECTIVE: Pregnancy and exercise have opposite effects on fat mass and insulin
resistance. We therefore designed this study to test the hypotheses that exercise
during pregnancy alters the pregnancy- associated increases in the levels of
tumor necrosis factor alpha and leptin and that the changes in tumor necrosis
factor alpha and leptin concentrations during pregnancy continue to reflect
changes in fat mass. STUDY DESIGN: The levels of tumor necrosis factor alpha and
leptin were measured longitudinally in a control group of physically active
women, a group of women who performed endurance exercises >/=4 times a week
throughout pregnancy, and a group of women who initially performed endurance
exercises but then stopped exercising during midpregnancy. Exercise was
monitored, and longitudinal estimates of maternal total mass and fat mass were
obtained. RESULTS: Tumor necrosis factor alpha levels were lower during pregnancy
in the women who exercised, and the same was true for leptin levels. When women
stopped exercising, however, both tumor necrosis factor alpha and leptin
concentrations rose at rates comparable to those seen in the physically active
control group. Changes in leptin concentration but not those in tumor necrosis
factor alpha concentration correlated with the pregnancy-associated increases in
total body and fat mass. CONCLUSIONS: Regular weight-bearing exercise during
pregnancy suppresses the pregnancy-associated changes normally seen in both tumor
necrosis factor alpha and leptin. The decrease in leptin reflects decreased fat
accretion, and we speculate that the changes in tumor necrosis factor alpha may
reflect a change in insulin resistance.
PMID- 10694329
TI - Eclampsia. VIII. Risk factors for maternal morbidity.
AB - OBJECTIVE: This study was undertaken to identify risk factors associated with
adverse maternal outcome in pregnancies complicated by eclampsia. STUDY DESIGN:
This was a descriptive study of 399 consecutive women with eclampsia whose cases
were managed at one perinatal center between August 1977 and July 1998. Data were
collected. Risk factors studied included maternal age, race, parity, preexisting
medical complications, and clinical and laboratory findings. Outcome variables
were maternal morbidities. Data were analyzed by either chi(2) analysis or the
unpaired Student t test as appropriate. RESULTS: In the entire cohort of women
with eclampsia major maternal complications included abruptio placentae (10%),
HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome (11%),
disseminated intravascular coagulopathy (6%), neurologic deficits and aspiration
pneumonia (7%), pulmonary edema (5%), cardiopulmonary arrest (4%), acute renal
failure (4%), and death (1%, n = 2 patients with antepartum onset). Women with
antepartum eclampsia had significantly higher incidences of abruptio placentae
(12% vs 6%; P <.05) and HELLP syndrome (14% vs 4%; P =. 005) than did those in
whom eclampsia developed post partum. In contrast, women with postpartum
eclampsia were more likely to have neurologic deficits develop (9% vs 2%; P
=.0006) than were those with antepartum eclampsia. In addition, women in whom
eclampsia developed at =32 weeks' gestation had significantly higher incidences
of abruptio placentae (17% vs 8%; P =.01), HELLP syndrome (20% vs 7%; P =.0005),
and acute renal failure (8% vs 2%; P =.01) than did those in whom eclampsia
developed later. CONCLUSION: Eclampsia remains a significant complication of
pregnancy that carries high maternal mortality and morbidity rates. Antepartum
onset carries greater risks, and onset at =32 weeks' gestation is particularly
dangerous to both mother and fetus.
PMID- 10694330
TI - Patterns of congenital anomalies and relationship to initial maternal fasting
glucose levels in pregnancies complicated by type 2 and gestational diabetes.
AB - OBJECTIVES: We sought to determine the types of congenital anomalies affecting
infants of women with gestational diabetes mellitus or type 2 diabetes and to
examine the relationship between those malformation types and measures of initial
glycemia of women at entry into prenatal care with type 2 diabetes or at time of
diagnosis in women with gestational diabetes mellitus. STUDY DESIGN: A total of
4,180 pregnancies complicated by gestational diabetes mellitus (n = 3764) or type
2 diabetes (n = 416) that were delivered after 20 weeks of gestation were
reviewed for the presence of congenital malformations diagnosed before hospital
discharge. Anomalies were categorized as being absent, minor, major, genetic
syndromes, or aneuploidies. Major anomalies were further categorized by the
number and type of affected organ systems. In addition to maternal clinical and
historical parameters, the initial fasting serum glucose either from the
diagnostic glucose tolerance test (gestational diabetes mellitus) or at entry to
prenatal care (type 2 diabetes) and the initial glycosylated hemoglobin before
insulin therapy were examined for a relationship to anomalies. RESULTS: The
initial fasting serum glucose and glycosylated hemoglobin levels were
significantly higher in pregnancies with major (n = 143) and minor (n = 112)
anomalies and genetic syndromes (n = 9) compared with pregnancies with no
anomalies (n = 3895). Of those pregnancies with major anomalies, the most
commonly affected organ systems were the cardiac (37.6%), musculoskeletal
(14.7%), and central nervous systems (9.8%) and anomalies involving multiple
organ systems (16%). There was no increased predominance of any specific organ
system involvement seen with increasing fasting serum glucose levels in
pregnancies with major congenital anomalies. Pregnancies with major anomalies
affecting multiple organ systems had significantly higher initial fasting serum
glucose levels (166 +/- 64 mg/dL) compared with pregnancies in which one organ
system was affected (141 +/- 55 mg/dL, P <.04) or no organ systems were affected
(115 +/- 38 mg/dL, P <.0001). CONCLUSION: Congenital anomalies in offspring of
women with gestational and type 2 diabetes affect the same organ systems that
have been previously described in pregnancies complicated by type 1 diabetes.
Increasing hyperglycemia at diagnosis or presentation for care was associated
with an increasing risk of anomalies in general and with anomalies involving
multiple organ systems without a preferential increase in involvement of specific
organ system.
PMID- 10694331
TI - Altered circulating levels of adhesion molecules at 18 weeks' gestation among
women with eventual preeclampsia: indicators of disturbed placentation in absence
of evidence of endothelial dysfunction?
AB - OBJECTIVE: The purpose of this study was to investigate whether indications of
activation of the maternal endothelium were present at 18 weeks' gestation in
women in whom preeclampsia eventually developed. STUDY DESIGN: A total of 2190
blood samples were obtained at 18 weeks' gestation. Circulating levels of von
Willebrand factor and soluble vascular adhesion molecule 1, soluble intercellular
adhesion molecule 1, and E-selectin were assayed in 71 women with eventual
preeclampsia and 71 control subjects. RESULTS: E-selectin and von Willebrand
factor levels were similar between the 2 groups. Soluble vascular adhesion
molecule 1 concentration was significantly lower in the women with eventual
preeclampsia (median, 649.0 ng/mL vs 762.4 ng/mL; P <.001), whereas soluble
intercellular adhesion molecule 1 concentration was significantly higher (median,
239.8 ng/mL vs 178.3 ng/mL; P <.001). CONCLUSION: We found no indications of
endothelial activation at 18 weeks' gestation in women in whom preeclampsia later
developed. However, decreased serum concentration of soluble vascular adhesion
molecule 1 and increased serum concentration of soluble intercellular adhesion
molecule 1 may reflect the disturbed placentation known to be associated with the
development of preeclampsia.
PMID- 10694332
TI - The international study of pregnancy outcome in women with maternal
phenylketonuria: report of a 12-year study.
AB - OBJECTIVE: The purpose of this report was to update the results of the Maternal
Phenylketonuria Collaborative Study, which was established to assess the efficacy
of a phenylalanine-restricted diet in preventing morbidity among the offspring of
women with hyperphenylalaninemia. STUDY DESIGN: During a 12-year period 576 women
with hyperphenylalaninemia were enrolled in this study. Outcome measures were
stratified according to classification of maternal hyperphenylalaninemia and the
time at which dietary control of phenylalanine level was achieved. RESULTS:
Optimal physical and cognitive fetal outcomes occurred when maternal blood
phenylalanine level <600 micromol/L was achieved by 8 to 10 weeks' gestation and
maintained throughout pregnancy (trimester average, =600 micromol/L).
CONCLUSIONS: The achievement of blood phenylalanine level control through a
phenylalanine-restricted diet significantly diminished the occurrence of
congenital abnormalities among offspring of women with hyperphenylalaninemia and
improved early intellectual progress of these offspring.
PMID- 10694333
TI - Does chondroitin sulfate defend the human uterine cervix against ripening in
threatened premature labor?
AB - OBJECTIVE: This study was undertaken to investigate changes in chondroitin
sulfate levels in the cervix and the physiologic role of chondroitin sulfate
isomers in the process of cervical ripening. STUDY DESIGN: Uterine cervical mucus
samples were obtained from 57 women (7 nonpregnant women, 19 at preterm
gestation, 9 at term gestation, 16 during the first stage of term labor, and 6
with threatened premature labor). Chondroitin sulfate isomer (chondroitin 0
sulfate, 4-sulfate, and 6-sulfate) concentrations in cervical mucus were measured
by high-performance liquid chromatography. The effect of exogenous chondroitin
sulfate on hyaluronidase activity in cervical mucus was evaluated by gel
permeation chromatography of fluorolabeled hyaluronic acid. RESULTS: Chondroitin
sulfate concentrations in cervical mucus were increased significantly (P <. 05)
in the threatened premature labor group compared with the preterm and term
groups. However, the same finding was not observed in the first stage of term
labor. Exogenous chondroitin sulfate inhibited hyaluronidase activity in mucus.
CONCLUSION: Chondroitin sulfate may defend against cervical ripening in
threatened premature labor.
PMID- 10694334
TI - Bipolar coagulation of the umbilical cord in complicated monochorionic twin
pregnancy.
AB - OBJECTIVES: In monochorionic twin pregnancy in which one twin is a nonviable
fetus, selective feticide may be considered. We aimed to occlude the umbilical
cord with a bipolar forceps for doing so. STUDY DESIGN: This was a multicenter
experience in 10 consecutive patients either with twin-to-twin transfusion
syndrome and one fetus affected by a condition not compatible with normal
extrauterine life or with acardiac twinning. RESULTS: There were no
intraoperative problems, and the mean procedure time was 17.5 minutes. The flow
was stopped in all 10 cases. Two cases were complicated by rupture of the fetal
membranes within 2 days, and the pregnancies were terminated. The other 8
pregnancies resulted in the live birth of a healthy baby. The mean interval
between procedure and birth was 15.1 weeks (range, 7-20 weeks). In one patient
emergency cesarean delivery for abruptio placentae was done at 26 weeks, 7 weeks
after the procedure. The other 7 patients were delivered beyond the 36th week of
gestation. All 8 children are alive and well, with a mean follow-up of at least 1
year. CONCLUSION: Bipolar coagulation is a safe, effective, and simple procedure
for cord coagulation that is feasible through a single port and can be performed
solely under ultrasonographic guidance.
PMID- 10694335
TI - Gestational diabetes mellitus diagnosed during early pregnancy.
AB - OBJECTIVE: This study was undertaken to compare pregnancy complications,
obstetric outcomes, and perinatal outcomes between women with early-onset and
late-onset gestational diabetes mellitus. STUDY DESIGN: Fifty-gram oral glucose
challenge screening was conducted among 3986 pregnant women at the time of their
first antenatal visit. Women without abnormal results underwent another test at
24 to 28 weeks' gestation. Patients with gestational diabetes mellitus in early
pregnancy were compared with those who had a normal glucose tolerance at the time
of this first test but in whom diabetes subsequently developed. RESULTS: Women
with early-onset gestational diabetes mellitus (n = 65) were likely to be
hypertensive (18.46% vs 5.88%; P =.006) and had higher glycemic values and need
for insulin therapy (33.85% vs 7.06%, P =.0000) than those in whom diabetes
developed later (n = 170). All the cases of neonatal hypoglycemia (n = 4) and all
perinatal deaths (n = 3) were within this group (P =.005 and P =.01,
respectively). CONCLUSIONS: Women with an early diagnosis of gestational diabetes
represent a high-risk subgroup.
PMID- 10694336
TI - Activation of peripheral leukocytes in rat pregnancy and experimental
preeclampsia.
AB - OBJECTIVE: The aim of this study was to search for activation markers of
peripheral leukocytes in experimental preeclampsia in the rat. STUDY DESIGN:
Experimental preeclampsia was induced in 14-day-pregnant rats by infusion of
endotoxin (1.0 microg/kg body weight). For comparison, rats with normal
pregnancies that were infused with sodium chloride solution and cyclic rats that
were infused with either endotoxin or sodium chloride solution were used. At
various points before and after the infusion, blood samples were withdrawn and
analyzed by means of whole-blood flow cytometry to evaluate expression of
inflammation-associated adhesion molecules (CD11b, CD11a, CD49d, and CD62L) and
CD14 on the leukocytes. RESULTS: Normal pregnancy was associated with increased
CD11b (granulocytes and monocytes), CD11a (monocytes and lymphocytes), and CD49d
(granulocytes, monocytes, and lymphocytes) expression. In addition to these
changes found in normal pregnancy, reduced CD62L and increased CD11a and CD49d
expression was found on granulocytes after endotoxin treatment of pregnant rats.
No effect of endotoxin was observed in cyclic rats. CONCLUSION: Leukocytes of
rats with experimental preeclampsia and, to a lesser extent, those of rats with
normal pregnancies had an activated phenotype. These results are consistent with
our previous findings in human subjects and suggest that (experimental)
preeclampsia results from a generalized inflammatory response.
PMID- 10694337
TI - Epidural analgesia need not increase operative delivery rates.
AB - OBJECTIVE: We sought to examine the relationship between epidural analgesia and
cesarean and instrumental vaginal delivery rates. STUDY DESIGN: This is a
retrospective analysis of the first 1000 nulliparous pregnancies in women with a
cephalic presentation in spontaneous labor at term in each of 3 different years,
over which the epidural rate increased from 10% to 57%. RESULTS: Cesarean and
instrumental vaginal delivery rates were similar in all 3 years. Demographic
characteristics remained unchanged or altered in a manner that has previously
been associated with an increase in intervention. Electronic fetal monitoring and
first-stage oxytocin use remained unchanged, but oxytocin use in the second stage
increased considerably. CONCLUSIONS: Increased use of epidural analgesia had no
effect on cesarean delivery rates. Although randomized trials have suggested that
it increases instrumental vaginal delivery rates, this might be overcome by
active management of labor or judicious use of oxytocin in the second stage.
PMID- 10694338
TI - Risks of preeclampsia and adverse neonatal outcomes among women with
pregestational diabetes mellitus. National Institute of Child Health and Human
Development Network of Maternal-Fetal Medicine Units.
AB - OBJECTIVES: This study was undertaken to determine the frequencies of
preeclampsia and adverse neonatal outcomes among women with pregestational
diabetes. STUDY DESIGN: This was a prospective observation of pregnancy outcomes
among 462 women with pregestational diabetes mellitus (White classes B-F) and
singleton pregnancies who were enrolled in a multicenter trial to compare low
dose aspirin with placebo for preeclampsia prevention. The main outcome measures
were preeclampsia and neonatal outcomes. RESULTS: Among 462 women with
pregestational diabetes, 92 (20%) had preeclampsia. Preeclampsia frequency rose
significantly with increasing severity of diabetes according to White
classification (class B, 11%; class C, 22%; class D, 21%; class R plus class F,
36%; P <.0001). Preeclampsia was also more common among women who had proteinuria
at baseline (28% vs 18%; odds ratio, 1.75; 95% confidence interval, 1.02-3.01).
Frequency of preterm delivery at <35 weeks' gestation rose greatly with
increasing severity of diabetes (P =.0002). Women with proteinuria at baseline
were significantly more likely to be delivered at <35 weeks' gestation (29% vs
13%; odds ratio, 2.6; 95% confidence interval, 1.5-4.6) and to have small-for
gestational-age infants (14% vs 3%; odds ratio, 5. 4; 95% confidence interval,
2.7-17.7), and they were less likely to have large-for-gestational-age infants
(14% vs 40%; odds ratio, 0.2; 95% confidence interval, 0.1-0.5). CONCLUSION:
Among women with pregestational diabetes mellitus, the frequency of preeclampsia
rose with increasing severity of diabetes. Proteinuria early in pregnancy was
associated with marked increases in adverse neonatal outcomes independent of
preeclampsia development.
PMID- 10694339
TI - Effective diminution of amniotic prostaglandin production by selective inhibitors
of cyclooxygenase type 2.
AB - OBJECTIVE: Cyclooxygenase inhibitors are effective tocolytic agents, but
significant adverse effects limit their use. We hypothesized that selective
inhibitors of the isozyme cyclooxygenase 2 would effectively diminish labor
associated prostaglandin production. STUDY DESIGN: We analyzed cyclooxygenase
type 1 and 2 expression in amnion, chorion, decidua, and myometrium from laboring
or nonlaboring women and tested the efficacy of selective cyclooxygenase 2
inhibition in diminishing prostaglandin production. RESULTS: The expression of
cyclooxygenase 2 in amnion from women in labor, either preterm or at term, was
significantly higher than in amnion before labor. In contrast, cyclooxygenase 1
expression was unchanged by labor. The enhanced expression of amniotic
cyclooxygenase 2 was associated with increased prostaglandin E(2) levels in
laboring women. Amniotic prostaglandin E(2) production was effectively diminished
by the selective cyclooxygenase 2 inhibitors SC-236 and NS-398 but not by the
cyclooxygenase 1 inhibitor SC-560. CONCLUSION: Selective inhibitors of
cyclooxygenase 2 are effective in diminishing prostaglandin production in vitro
and may be useful in prevention of preterm deliveries.
PMID- 10694340
TI - Fetal renal volume assessment by three-dimensional ultrasonography.
AB - OBJECTIVE: This study was undertaken to measure fetal renal volume by means of
three-dimensional ultrasonography and to use those data to establish the accurate
constant and formula for fetal renal volume assessment with two-dimensional
ultrasonography. STUDY DESIGN: Singleton fetuses between 15 and 40 weeks'
gestation were included. The volumes of both fetal kidneys were measured with
three-dimensional ultrasonography. Three fetal renal diameters (largest
anteroposterior, transverse, and longitudinal diameters) were measured, and the
constant of the fetal renal volume formula was calculated. Linear regression
curves were made for each kidney from the fetal renal volume, the three
diameters, and the constant. RESULTS: A total of 112 fetuses were included. The
following fetal renal volume formula was established: Fetal renal volume =
Constant (R) x Largest anteroposterior diameter (x) x Largest transverse diameter
(y) x Largest longitudinal diameter (z). The volumes, the three diameters, and
the constants appeared different between the right and left kidneys but not
statistically significantly so. CONCLUSION: Three-dimensional ultrasonography is
useful in assessing fetal renal volume. The fetal renal volume formula makes
possible accurate measurements of fetal renal volume by two-dimensional
ultrasonography.
PMID- 10694341
TI - Important role of 72-kd heat shock protein expression in the endothelial cell in
acquisition of hypoxic-ischemic tolerance in the immature rat.
AB - OBJECTIVES: Hypoxic-ischemic tolerance can be induced in neonatal rats through
hyperthermic preconditioning. The purposes of this study were to determine the
interval between hyperthermic preconditioning and a subsequent hypoxic-ischemic
insult that would provide optimal neuroprotection against the insult and to
examine the relationship between tolerance induction and heat shock protein
expression. STUDY DESIGN: On postnatal day 7 Wistar rat pups were separated into
the following 2 groups: a heated group (those exposed to 15 minutes of
hyperthermic pretreatment at a brain temperature of 41.5 degrees C-42.0 degrees
C) and an unheated control group. At 6, 12, 24, 48, and 72 hours after the
hyperthermic stress, rats from both groups were exposed to left carotid artery
ligation followed by 2 hours of hypoxia (8% oxygen and 92% nitrogen) at 33
degrees C. Twenty animals from each group were used at each time point. All rats
were killed at 1 week after hypoxia-ischemia, at which time the brains were
processed and neuronal damage in the cortex and hippocampus was assessed
histologically. Another set of 7-day-old rats (n = 30) was studied
immunohistochemically at 6, 12, 24, 48, and 72 hours after the same hyperthermic
treatment. Expression of 72-kd heat shock protein was measured in neuronal,
glial, and vascular endothelial cells. RESULTS: Hyperthermia-induced hypoxic
ischemic tolerance was observed at 6, 12, and 24 hours but not at 48 and 72 hours
after hyperthermic preconditioning. Heat shock protein 72 expression in the
vascular endothelial cells, rather than in the glial or neuronal cells, was most
strongly associated with hypoxic-ischemic tolerance. CONCLUSION: These findings
suggest that heat shock protein 72 in endothelial cells plays an important role
in the acquisition of hypoxic-ischemic tolerance at postnatal day 7, a time when
maximal angiogenesis occurs and the blood-brain barrier is still immature.
PMID- 10694342
TI - Preclinical development of noninvasive vascular occlusion with focused ultrasonic
surgery for fetal therapy.
AB - OBJECTIVE: This study was undertaken to investigate the ability of focused
ultrasonic surgery to occlude blood flow in vivo. STUDY DESIGN: A 5-mm linear
track exposure of 1.7-MHz focused ultrasound was applied across the femoral
vessels for 5 seconds. Free field spatial peak intensities in the range of 1,000
to 4,660 W x cm(-2) were used. Vascular occlusion was confirmed after
demonstration of an absent distal arterial pulse and an absent flow signal on
magnetic resonance angiography and subtracted (after minus before) contrast
enhanced dual-echo steady-state sequences. RESULTS: The minimum intensity for
consistent vascular occlusion was 1,690 W x cm(-2) at a focal depth of 5 mm when
the transducer was moved at 1 mm x s(-1) orthogonal to the direction of blood
flow. CONCLUSIONS: This study demonstrates that focused ultrasonic surgery can
achieve reproducible vascular occlusion in vivo. Potential obstetric applications
include noninvasive ultrasonographically guided occlusion of placental vessels
mediating interfetal transfusion in monochorionic twins.
PMID- 10694343
TI - The application of color power angiography to the longitudinal quantification of
blood flow volume in the fetal middle cerebral arteries, ascending aorta,
descending aorta, and renal arteries during gestation.
AB - OBJECTIVE: This study was undertaken to determine by means of color power
angiography the longitudinal changes in the diameters and the flow volumes of 4
major fetal arteries during gestation. STUDY DESIGN: The middle cerebral artery,
the ascending aorta, the descending aorta, and the renal arteries in 81
appropriate-for-gestational-age fetuses were examined longitudinally between 24
and 38 weeks' gestation by means of color power angiography. In addition to
measurement of the diameters of these arteries, Doppler velocimetry was
performed. Flow volume was calculated from the cross-sectional areas of the
arteries and the velocity integral of the Doppler waveforms. RESULTS: The mean
(+/-SD) gestational age at delivery and birth weight were 39.8 +/- 1. 6 weeks and
3326 +/- 345 g, respectively. The diameters and flow volumes of all the arteries
increased significantly as gestational age advanced. Flow volume increased from
39 +/- 19.0 mL/min to 140 +/- 63.9 mL/min in the middle cerebral artery, from
216.2 +/- 77.6 to 937.4 mL/min in the ascending aorta, from 124.4 +/- 76.6 to
390.0 mL/min in the descending aorta, and from 27.5 +/- 16.8 to 80.3 +/- 57.3
mL/min in the renal arteries. When blood flow volume was adjusted to milliliters
per kilogram body weight, an initial significant fall in blood flow was seen in
all the vessels to a minimal level at 30 weeks' gestation; blood flow rose
thereafter, although not significantly, until term. The ratios of flow volume in
the ascending aorta to those in the other vessels increased with gestation, with
the highest ratio being that between the ascending aorta and the renal arteries.
CONCLUSION: Identification of fetal arteries with color power angiography is easy
and highly sensitive. The distributions of blood flow in various fetal arteries
exhibited regional differences, with significantly more blood flow to the brain.
These normative baseline values may be useful in the diagnosis of congenital
cardiac anomalies and also in the diagnosis and monitoring of fetuses with
intrauterine growth restriction.
PMID- 10694344
TI - Effects of antenatal endotoxin and glucocorticoids on the lungs of preterm lambs.
AB - OBJECTIVE: We hypothesized that the proinflammatory response to intra-amniotic
endotoxin would induce lung maturation in preterm lambs. STUDY DESIGN: Ewes were
randomly assigned to receive 20 mg Escherichia coli endotoxin by intra-amniotic
injection, maternal betamethasone (0.5 mg/kg), or sodium chloride solution.
Preterm lambs were delivered at 125 days' gestation and underwent ventilation to
assess lung function. Lung gas volume, surfactant concentrations, and
inflammation were subsequently evaluated, with data analyzed by analysis of
variance. RESULTS: Fetal endotoxin exposure 6 days before delivery increased
compliance by 59%, increased lung gas volume 2.3-fold, increased concentrations
of surfactant lipids, increased surfactant A and B protein levels, and increased
messenger ribonucleic acid expressions for surfactant proteins (all P <.01, vs
control group). Betamethasone exposure resulted in less consistent effects. White
blood cell counts were increased in fetal membranes and lungs after endotoxin
exposure, but there was no severe inflammation. CONCLUSION: A single fetal
exposure to endotoxin resulted in large improvements in postnatal lung function
and increases in surfactant concentrations after preterm delivery. These effects
were qualitatively larger than those achieved with betamethasone.
PMID- 10694345
TI - Increased concentration of pro-matrix metalloproteinase 9 in term fetal membranes
overlying the cervix before labor: implications for membrane remodeling and
rupture.
AB - OBJECTIVES: Regional structural alterations that develop before labor are
important in the mechanisms of both physiologic and pathologic membrane rupture,
because they are also detected in preterm prelabor rupture of the fetal
membranes, the most common cause of preterm birth (as great as 60%). Matrix
metalloproteinases are located in the fetal membranes and are the main mediators
of extracellular matrix degradation. The objective of this study was to examine
whether gelatinases (matrix metalloproteinases 2 and 9) could be involved in the
development of these regional structural changes seen at term before labor. STUDY
DESIGN: Fetal membranes from patients undergoing elective cesarean delivery were
regionally sampled from over the cervix (cervical membranes) and midway between
this area and the placental edge (midzone). Fetal membranes obtained after
spontaneous labor and delivery at term were also regionally sampled. Matrix
metalloproteinase 2 and 9 activities were assessed by gelatin zymography, whereas
total matrix metalloproteinase 9 protein was determined by enzyme-linked
immunosorbent assay. RESULTS: Zymography only detected activity corresponding to
the pro-matrix metalloproteinase 2 (72 kd) and 9 (92 kd) forms in prelabor fetal
membranes. Although the levels of pro-matrix metalloproteinase 2 showed no
regional differences, the pro-matrix metalloproteinase 9 level was higher in the
cervical area than in the midzone (2.5 +/- 0.98 vs 0.76 +/- 0.28 optical density
units/20 microg protein; P <.01). The concentration of pro-matrix
metalloproteinase 9 protein in the cervical area was also significantly higher
than that in the midzone (6.69 +/- 4.8 vs 1.58 +/- 1.14 ng/mg protein; P <.01).
After delivery both pro-matrix metalloproteinase 2 and 9 activities were
elevated, whereas pro-matrix metalloproteinase 9 protein activity showed no
regional difference between the rupture site and midzone (23.47 +/- 4.5 vs 25. 3
+/- 6.2 ng/mg protein). Active bands of matrix metalloproteinases 2 (66 kd) and 9
(83 kd) were also detected after delivery. CONCLUSION: This study suggests that a
specific regional induction of pro-matrix metalloproteinase 9 occurs in the
cervical area before labor and may play a role in "programming" this area for
subsequent rupture after activation during labor.
PMID- 10694346
TI - Placental angioarchitecture in monochorionic twin pregnancies: relationship to
fetal growth, fetofetal transfusion syndrome, and pregnancy outcome.
AB - OBJECTIVE: We sought to correlate placental vasculature with fetal growth and
outcome in monochorionic twins. STUDY DESIGN: Eighty-two patients with
consecutive monochorionic pregnancies underwent biweekly ultrasonography for
determination of fetal growth and well-being. After delivery, blinded placental
injection studies delineated vascular anastomoses and territory share. Degree of
balance in arteriovenous anastomoses equaled the number of arteriovenous
anastomoses in one direction minus the number in the other. RESULTS: Pregnancies
affected by fetofetal transfusion syndrome (n = 21) had numbers of arteriovenous
and venovenous anastomoses that were similar to those in pregnancies without
fetofetal transfusion syndrome but fewer arterioarterial anastomoses (P <.0001).
Fetofetal transfusion syndrome occurred in 78% of pregnancies with >/=1
arteriovenous and no arterioarterial anastomoses. Birth weight discordancy
correlated with placental territory discordancy (P <.0001) and the degree of
balance in arteriovenous anastomoses (P =.004). The larger placental share twin
had a greater growth velocity than its smaller placental share co-twin (P =.008)
for all but one anastomotic pattern. Where arteriovenous anastomoses were aligned
with the net venous outflow to the fetus with the smaller territory, co-twins had
similar birth weights and growth velocities irrespective of placental share.
Fetal survival was higher in pregnancies with an arterioarterial anastomosis (P
=.01) but lower with a venovenous anastomosis (P =. 01). Survival of both fetuses
was inversely associated with birth weight discordancy (P <.0001). CONCLUSION:
Although interrelationships among the various types of anastomoses are complex,
our data suggest that the placental territory share and the pattern of
arteriovenous anastomoses influence fetal growth, that arterioarterial
anastomoses protect against fetofetal transfusion syndrome, and that venovenous
anastomoses reduce perinatal survival.
PMID- 10694347
TI - Esophageal atresia in the Northern Region Congenital Anomaly Survey, 1985-1997:
prenatal diagnosis and outcome.
AB - OBJECTIVE: This study was undertaken to determine the rate of prenatal diagnosis
and surgical outcome of all cases of esophageal atresia reported to the Northern
Region Congenital Anomaly Survey. STUDY DESIGN: A retrospective review was
conducted on maternal and infant case notes of all cases of esophageal atresia in
the Northern Region from 1985-1997, inclusive. RESULTS: A total of 176 cases of
esophageal atresia was reported, and 158 diagnoses were confirmed after birth.
Six cases were excluded because of incomplete data. Among the 32 patients in whom
esophageal atresia was suspected antenatally because of an absent stomach bubble
and hydramnios, 14 (44%) had esophageal atresia confirmed postnatally. In 10 of
the 18 patients with false-positive diagnoses the stomach was subsequently seen.
Esophageal atresia should have been suspected prenatally in a further 38 patients
with polyhydramnios, 3 of whom also had an absent stomach bubble. There were 12
pregnancy terminations, 1 spontaneous abortion, and 19 perinatal deaths
(including 9 stillbirths). Among the patients with esophageal atresia, 63.2% had
associated anomalies (including 5.3% with aneuploidy), and 78.4% of these
anomalies were missed prenatally. Among the live births 21.5% of the infants had
a birth weight below the 5th percentile. One hundred eight (90%) had esophageal
atresia with a distal tracheoesophageal fistula, and overall 102 (85%) underwent
a primary repair. Among the 120 infants who underwent surgical treatment 11
subsequently died, and 6 of these deaths were related to postoperative
complications. Thirty-nine infants (32.5%) had postoperative gastroesophageal
reflux, necessitating fundoplication in 21 cases. At 2-year follow-up 23 of 89
infants had dysphagia, for which 7 still required a gastrostomy or jejunostomy.
Infants in whom the condition was diagnosed prenatally were more likely to need
prolonged mechanical ventilation, to have a longer hospital stay, and to have
long-term gastrointestinal problems. CONCLUSIONS: Most cases of esophageal
atresia are not suspected prenatally. Among fetuses with ultrasonographic
features suggestive of esophageal atresia, 50% have the disorder confirmed
postnatally. Overall perinatal and infant mortality rate among those with
esophageal atresia is high (21.6%), and a further 21% of affected infants have
significant morbidity after the age of 2 years.
PMID- 10694348
TI - The role of estrogen in the maintenance of primate pregnancy.
AB - OBJECTIVE: The aim of this study was to determine the role of estrogen in
pregnancy maintenance in baboons by suppressing estrogen synthesis through
administration of a highly specific nonsteroidal aromatase inhibitor, CGS 20267.
STUDY DESIGN: CGS 20267 was administered subcutaneously at maximal dosages of 2.0
mg/d to pregnant baboons (n = 24) daily beginning on either day 30 (n = 8), day
60 (n = 8), or day 100 (n = 8) of gestation (normal length of gestation is 184
days) until animals miscarried or were delivered abdominally on days 160 through
168 of gestation. CGS 20267 and estradiol (n = 9), each at maximal dosages of 2
mg/d, were administered at the same intervals of gestation. Twenty baboons served
as untreated control animals. Serum estradiol and progesterone levels were
determined by radioimmunoassay from serum samples obtained at 1- to 3-day
intervals from a maternal peripheral vein. RESULTS: Within 1 to 3 days of the
initiation of CGS 20267 administration, maternal serum estradiol concentration
decreased to and remained at a level that was substantially lower (mean +/- SE,
0. 096 +/- 0.003 ng/mL) than in the untreated control animals throughout
gestation (0.35-4.0 ng/mL; P <.001). Although pregnancy was maintained in 19 of
the 20 untreated control baboons (95%), only 12 of the 24 animals that received
CGS 20267 (50%) maintained pregnancy. In contrast, all the baboons treated
concomitantly with estradiol and CGS 20267 (9/9) maintained pregnancy. Thus
estradiol alone prevented the high rate of miscarriage induced by the
antiestrogenic agent CGS 20267. Serum progesterone concentrations were not
significantly different throughout the experimental period between the CGS 20267
treated baboons that maintained pregnancy (12. 9 +/- 1.4 ng/mL) and those that
miscarried (13.6 +/- 1.6 ng/mL) and were not lower in antiestrogen-treated
baboons than in untreated control baboons (10.6 +/- 0.8 ng/mL). CONCLUSION:
Estrogen, acting directly, indirectly, or both through a factor or factors other
than the level of progesterone, plays a critically important physiologic role in
the maintenance of primate pregnancy.
PMID- 10694349
TI - The effect of fetal fibronectin testing on admissions to a tertiary maternal
fetal medicine unit and cost savings.
AB - OBJECTIVE: Fetal fibronectin bedside testing has been proposed as a diagnostic
tool for the accurate diagnosis of preterm labor. The study objective was to
determine whether the introduction of routine fetal fibronectin bedside testing
affected costs and transfer rates from referral district hospitals to a tertiary
obstetric hospital, as well as direct admissions to a tertiary referral hospital.
STUDY DESIGN: We performed an 18-month prospective audit of fetal fibronectin use
in 9 referral hospitals and one university maternal-fetal medicine unit. Data
collected were delivery details and cervical dilatation at admission. Cost
savings in terms of transport costs for patients with a negative fetal
fibronectin result who were not transferred or admitted to the tertiary center
were calculated for interhospital transfer (road ambulance or fixed-wing
retrieval). RESULTS: One hundred fifty-one patients had a presumptive diagnosis
of threatened preterm labor. Forty-five patients had a positive fetal fibronectin
result and 106 had a negative fetal fibronectin result (3 with cervical
dilatation >/=3 cm). Eleven (24%) patients with a positive fetal fibronectin
result were delivered within 7 days, and 5 (5%) with a negative fetal fibronectin
result were delivered within 7 days. One patient was delivered at 34 weeks, and
the remaining patients were delivered at or after 36 weeks' gestation. All 3
patients with negative fetal fibronectin results with cervical dilatation of >/=3
cm were delivered within 5 days, leaving 2 (1.9%) patients (with closed cervices
and negative fetal fibronectin results) being delivered 5 days after the fetal
fibronectin testing. Ninety percent of the patients admitted to a referral
hospital with threatened preterm labor who had a negative fetal fibronectin
result were not transferred; thus an unnecessary transfer was avoided, with cost
savings ranging from $30,297 for road and fixed-wing transport. CONCLUSION: A
negative fetal fibronectin result is not helpful if cervical dilatation is
present, and these patients should be treated as having a high risk of preterm
delivery. The use of a fetal fibronectin test was associated with a 90% reduction
in maternal transfer and can substantially reduce the costs and inconvenience
associated with unnecessary transfer.
PMID- 10694350
TI - Low midpregnancy placental volume in rural Indian women: A cause for low birth
weight?
AB - OBJECTIVE: We sought to study midpregnancy placental volume in rural Indian
women, its maternal determinants, and its relationship to neonatal size. STUDY
DESIGN: We performed a prospective community-based study of maternal nutrition
and fetal growth in 6 villages near the city of Pune. Measurements included
midpregnancy placental volume determined by means of ultrasonography at 15 to 18
weeks' gestation, maternal anthropometric measurements before and during
pregnancy, and maternal blood pressure and biochemical parameters during
pregnancy. Neonatal size and placental weight were measured at birth. RESULTS:
The mothers were short and underweight (mean height, 1.52 m; weight, 42 kg; body
mass index, 18 kg/m(2)) and produced small babies (mean birth weight, 2648 g).
Midpregnancy placental volume (median, 144 mL) was related to the mother's
prepregnancy weight (r = 0.15; P <.001) but not to weight gain during pregnancy,
blood pressure, or circulating hemoglobin, ferritin, red blood cell folate, or
glucose concentrations. Midpregnancy placental volume was related to placental
weight at birth (r = 0.29; P <.001) and birth weight (r = 0.25; P <.001)
independent of maternal size. CONCLUSION: In Indian mothers midpregnancy
placental volume is significantly associated with prepregnant maternal weight and
is an independent predictor of birth weight. Our findings may provide clues to
the high prevalence of low-birth-weight infants in India.
PMID- 10694351
TI - Histologic and biochemical study of the brain, heart, kidney, and liver in
asphyxia caused by occlusion of the umbilical cord in near-term fetal lambs.
AB - OBJECTIVE: We sought to determine the relationship between the degree of
histologic changes in the brain, heart, kidney, and liver in fetal lambs after
severe asphyxia and to analyze the role of oxidative stress in the pathogenesis
of fetal multiple organ failure. STUDY DESIGN: Eight chronically instrumented
near-term fetal lambs were asphyxiated by partial umbilical cord occlusion for
approximately 60 minutes until the fetal arterial pH reached <6.9 and the base
excess reached <-20 mEq/L. An additional 6 fetuses were used as sham-asphyxiated
controls. Fetal heart rates, blood pressure, fetal breathing movements, and
arterial blood gases and acid-base states were serially monitored. The brain,
heart, kidney, and liver were collected 72 hours after asphyxia, processed, and
histologically examined after hematoxylin and eosin staining. Fetal brain
histologic features were classified into 5 grades, with 5 being the most severe
damage. The other organs were examined histologically by pathologists who were
blinded to the treatment. Each organ was assayed for tissue concentrations of
thiobarbituric acid-reactive substances, superoxide dismutase, glutathione,
lactate, and glucose. RESULTS: Myocardial changes of necrosis, phagocytosis, and
contraction bands occurred in only 2 of the most severely (grade 5) brain-damaged
fetuses. The same 2 cases showed fatty changes and congestion in the liver. In
the kidney all asphyxiated cases showed tubular necrosis, but glomeruli were
generally spared. Of the measures of oxidative stress, only liver tissue levels
of thiobarbituric acid-reactive substances and superoxide dismutase were
significantly higher in the asphyxiated group than in the control group, but
there was no correlation with the degree of damage. Lactate level was higher only
in the heart in the asphyxiated fetuses. CONCLUSION: Renal tubular damage was
seen with all degrees of asphyxia, despite variable brain damage. Histologic
changes in the myocardium and liver were seen only with the most severe brain
damage. Oxidative stress appears to play a role in the pathogenesis of liver
damage.
PMID- 10694352
TI - Reduction-oxidation (redox) state regulation of matrix metalloproteinase activity
in human fetal membranes.
AB - OBJECTIVE: The mechanisms underlying membrane rupture at term and preterm are
obscure. Collagenolytic activity of matrix metalloproteinases in amniochorionic
membranes increases during spontaneous term and preterm labor associated with
intra-amniotic infection. We sought to test the hypothesis that reduction
oxidation homeostasis, which is altered in inflammatory states, directly
regulates amniochorionic matrix metalloproteinases. STUDY DESIGN: Membranes were
collected from 7 patients undergoing elective cesarean delivery at term, rinsed
thoroughly, and immediately incubated in phosphate-buffered sodium chloride
solution at 37 degrees C for 24 hours. Matrix metalloproteinase activity in the
culture medium was assayed by substrate-gel electrophoresis and normalized
against the dry weight of the tissue incubated. Superoxide anions were generated
in the presence of membranes by a xanthine (2 mmol/L) and xanthine oxidase (20
mU/mL) mixture and monitored by reduction of ferri-cytochrome c to ferro
cytochrome c. Incubations were performed in the presence of xanthine alone, a
xanthine-xanthine oxidase mixture, superoxide dismutase (500 U/mL), a xanthine
xanthine oxidase-superoxide dismutase mixture, nitro-L-arginine (a nitric oxide
synthase inhibitor, 1 mmol/L), xanthine-xanthine oxidase-nitro-L-arginine, S
nitroso-N -acetylpenicillamine (a nitric oxide donor, 10 mmol/L), xanthine
xanthine oxidase-S-nitroso-N -acetylpenicillamine, N -acetylcysteine (a thiol
containing antioxidant, 0.1, 1, or 10 mmol/L), lipopolysaccharide (100 ng/mL), or
lipopolysaccharide-N -acetylcysteine. Intracellular generation of superoxide
anions was monitored by the reduction of nitroblue tetrazolium to formazan.
RESULTS: Basal matrix metalloproteinase 9 and matrix metalloproteinase 2 levels
were detected in all samples. Superoxide anions significantly increased matrix
metalloproteinase 9 activity but did not increase matrix metalloproteinase 2
activity, which effect was reversed by the addition of superoxide dismutase. N
acetylcysteine reduced basal activity of both matrix metalloproteinase 9 and
matrix metalloproteinase 2 to 20%. Importantly, N-acetylcysteine completely
inhibited intracellular formazan formation in cultured membranes both in the
absence and in the presence of lipopolysaccharide. Neither nitric oxide synthase
inhibition nor the nitric oxide donor S-nitroso-N -acetylpenicillamine had any
effect on fetal membrane matrix metalloproteinase activity. CONCLUSION: Matrix
metalloproteinase activity in human fetal membranes is reduction-oxidation
(redox)-regulated. Matrix metalloproteinase 9 activity in human fetal membranes
is directly increased by superoxide anion, a byproduct of macrophages and
neutrophils. Neither nitric oxide donors nor nitric oxide synthase inhibitors
significantly affect matrix metalloproteinase activity in human fetal membranes.
The glutathione precursor N-acetylcysteine dramatically inhibits amniochorionic
matrix metalloproteinase activity in addition to inhibiting intrinsic superoxide
generation within the tissue. Thus thiol-reducing agents, such as N
acetylcysteine, may be beneficial in preventing preterm premature rupture of the
membranes.
PMID- 10694353
TI - A systematic review and meta-analysis of prospective studies on the association
between maternal cigarette smoking and preterm delivery.
AB - We have attempted to quantify the most up-to-date estimate of the association
between cigarette smoking by the mother and preterm delivery. Studies were
selected for inclusion in this review if they were prospective, reported data
stratified across at least two levels of maternal smoking, and defined preterm
delivery on the basis of gestational age. In a meta-analysis we combined results
from multiple studies that reported on preterm delivery and maternal smoking
during pregnancy. Pooled odds ratios were computed for various strata of smoking
intensity with the Mantel-Haenszel fixed-effects model. Twenty studies met all
inclusion criteria and were included in meta-analysis. The pooled point estimate
from 20 prospective studies on any maternal smoking versus no maternal smoking
was 1.27 (95% confidence interval, 1.21-1.33). Subgroup analyses stratifying
maternal smoking on number of cigarettes per day suggest a dose-response
relationship at low to moderate levels of smoking, which was not further
increased at high levels of smoking. A nonsignificant level of publication bias
appears to exist in the smoking-preterm delivery literature. Cigarette smoking is
a preventable risk factor that is associated with preterm delivery. Consistent
results across many study populations and research designs and evidence of a dose
response relationship support its causal role in preterm delivery.
PMID- 10694354
TI - Failure of initiation of parturition after electrocoagulation of the pituitary of
the fetal lamb. American Journal of Obstetrics and Gynecology, volume 98, app.
1080-1086, 1967.
PMID- 10694355
TI - The role of the hypothalamic-pituitary-adrenal axis in preparing the fetus for
birth.
PMID- 10694356
TI - Safety of multiple courses of corticosteroid treatment.
PMID- 10694358
TI - Value of human papillomavirus testing.
PMID- 10694360
TI - Ethics committee approval of published study.
PMID- 10694362
TI - Intrauterine insemination--how far should we go?
PMID- 10694364
TI - The role of the StAR protein in steroidogenesis: challenges for the future.
AB - The steroidogenic acute regulatory or StAR protein has been shown to be
instrumental in the acute regulation of steroid hormone biosynthesis through its
action in mediating cholesterol transfer to the inner mitochondrial membrane and
the cholesterol side chain cleavage enzyme system. Since the time of its cloning
in 1994, a number of studies have been performed which underscore the important
role that this protein plays in steroidogenesis. While it is now quite apparent
that StAR fulfills the criteria for the acute regulator as proposed by early
studies, several crucial areas remain poorly understood. This list is topped by
the so far intractable nature of the mechanism of action of StAR in transferring
cholesterol to the P450scc enzyme. A second area which should prove to be of
great interest is that of further understanding the regulation of the StAR gene
which, like many genes, is quite complex. Lastly, with the recent demonstration
of StAR being present in the brain, determining if StAR has a role in the
synthesis of neurosteroids should prove to be of great importance.
PMID- 10694365
TI - ACTH treatment disrupts ovarian IGF-I and steroid hormone production.
AB - Hyper-adrenal activity and increased glucocorticoid hormone release are
associated with disruptions in reproductive function and adverse effects on the
ovary. The aim of this investigation was to determine whether elevated
glucocorticoid hormone levels can influence ovarian IGF-I synthesis and action in
vivo. To elevate endogenous glucocorticoid levels, gilts were treated with ACTH
during the luteal phase of the oestrous cycle (days 9-13) while the control group
received saline. The gilts were subsequently ovariectomized on either day 14 or
day 18 of the oestrous cycle. Follicular fluid (FF) was collected from individual
follicles; IGF-I and steroid hormone concentrations were determined by
radioimmunoassay, and IGF-binding protein (IGFBP) expression was assessed by
Western ligand blotting. Granulosa cells were also recovered and placed in
culture to determine IGF-I, progesterone (P(4)) and oestradiol-17beta (E(2))
production levels. The cells were cultured in serum-free medium for 5 days and
supplemented with: (a) media alone, (b) IGF-I, (c) FSH and androstenedione
(A(4)), or (d) IGF-I with FSH and A(4). The FF from ACTH-treated gilts was
characterized by elevated (P<0.05) cortisol levels on day 14 and lower (P<0.05)
E(2) values on both day 14 and day 18. Lower (P<0.05) IGF-I concentrations were
also measured in the FF of ACTH-treated gilts collected on day 18. This altered
hormone profile in FF was associated with impaired IGF-I and steroid hormone
synthesis by granulosa cells. IGF-stimulated P(4) production (P<0.01) by cells
recovered from ACTH-treated gilts on day 14 was lower (P<0.05). By day 18, IGF-I,
P(4) and E(2) production by cells from the ACTH group were all significantly
(P<0. 05) lower. These results demonstrate that increased glucocorticoid
concentrations can disrupt subsequent ovarian IGF-I synthesis and IGF action in
vivo and can, potentially, impair follicle maturation.
PMID- 10694366
TI - Effect of neonatal and adult testosterone treatment on the cellular composition
of the adult female rat anterior pituitary.
AB - The adult female pituitary has significantly more lactotrophs than that of the
male, while the later has a higher percent of somatotrophs. It is clear that GH
and prolactin (PRL) gene expression and somatotroph and lactotroph proliferation
are modulated by the postpubertal hormone environment; however, the role of the
neonatal steroid environment in this process is not known. We have used in situ
hybridization to determine the number of GH and PRL mRNA-containing cells, as
well as the level of expression of these two hormones, in response to neonatal
and adult testosterone treatment. Female rats exposed to testosterone during the
neonatal period, adulthood or both periods, as well as normal females and males
were used. Exposure to testosterone during the neonatal period significantly
increased the percentage of somatotrophs (ANOVA: P<0. 005) and decreased that of
lactotrophs in the adult female rat (ANOVA: P<0.001). Adult testosterone
treatment had no significant effect on the percentage of somatotrophs. The
percentage of lactotrophs was significantly increased by adult testosterone only
in those rats also exposed to neonatal testosterone. PRL mRNA concentrations, as
reflected by silver grains/cell, were reduced by neonatal testosterone and
increased by adult testosterone treatment (ANOVA: P<0.0001). Overall PRL mRNA
levels, measured by densitometry, were also reduced by neonatal testosterone
exposure, but adult testosterone had no effect (ANOVA: P<0.001). GH mRNA levels
per cell, as reflected by silver grains/cell, were increased by adult
testosterone, while neonatal testosterone treatment had no effect. Overall GH
mRNA levels per unit area, determined by densitometry measurements, were
increased by both neonatal and adult testosterone treatment, with the combination
of these two treatments resulting in adult females having levels
indistinguishable from intact males (ANOVA: P<0.003). These results suggest that,
in combination with postpubertal sex steroids, the neonatal gonadal steroid
environment plays an important role in determining anterior pituitary hormone
synthesis and cellular composition.
PMID- 10694367
TI - Prolactin induction of insulin gene expression: the roles of glucose and glucose
transporter-2.
AB - Previous studies have shown that lactogenic hormones stimulate beta-cell
proliferation and insulin production in pancreatic islets. However, all such
studies have been conducted in cells incubated in medium containing glucose.
Since glucose independently stimulates beta-cell replication and insulin
production, it is unclear whether the effects of prolactin (PRL) on insulin gene
expression are exerted directly or through the uptake and/or metabolism of
glucose. We examined the interactions between glucose and PRL in the regulation
of insulin gene transcription and the expression of glucose transporter-2 (glut
2) and glucokinase mRNAs in rat insulinoma (INS-1) cells. In the presence of 5.5
mM glucose, the levels of preproinsulin and glut-2 mRNAs in PRL-treated cells
exceeded the levels in control cells (1.7-fold, P<0.05 and 2-fold, P<0.05
respectively). The maximal effects of PRL were noted at 24-48 h of incubation.
PRL had no effect on the levels of glucokinase mRNA. The higher levels of glut-2
mRNA were accompanied by an increase in the number of cellular glucose
transporters, as demonstrated by a 1. 4- to 2.4-fold increase in the uptake of 2
deoxy-d-[(3)H]glucose in PRL-treated INS-1 cells (P<0.001). These findings
suggested that the insulinotropic effect of PRL is mediated, in part, by
induction of glucose transport and/or glucose metabolism. Nevertheless, even in
the absence of glucose, PRL stimulated increases in the levels of preproinsulin
mRNA (3.4-fold higher than controls, P<0.0001) and glut-2 mRNA (2-fold higher
than controls, P<0.01). These observations suggested that PRL exerts glucose
independent as well as glucose-dependent effects on insulin gene expression.
Support for this hypothesis was provided by studies of insulin gene transcription
using INS-1 cells transfected with a plasmid containing the rat insulin 1
promoter linked to a luciferase reporter gene. Glucose and PRL, alone and in
combination, stimulated increases in cellular luciferase activity. The relative
potencies of glucose (5.5 mM) alone, PRL alone, and glucose plus PRL in
combination were 2.2 (P<0.001), 3.4 (P<0.01), and 7.9 (P<0.0001) respectively.
Our findings suggest that glucose and PRL act synergistically to induce insulin
gene transcription.
PMID- 10694368
TI - Two free isoforms of ovine glycoprotein hormone alpha-subunit strongly differ in
their ability to stimulate prolactin release from foetal pituitaries.
AB - alpha-Subunit dissociated from glycoprotein hormones has been previously shown to
stimulate rat pituitary lactotroph differentiation and proliferation. However,
whether the free form of the alpha-subunit (free alpha) can also play such a role
is not known. To test whether free alpha may act on prolactin (PRL) release from
ovine foetal pituitaries, this molecule was purified and two major isoforms,
alphaA and alphaB were isolated. Free alphaA was found to be more acidic and more
hydrophobic than both free alphaB and ovine LH alpha-subunit (oLHalpha). Free
alphaA and oLHalpha exhibited a molecular mass of 14 kDa as determined by mass
spectrometry, whereas free alphaB displayed a molecular mass of only 13.5 kDa
because of its truncated N-terminus. All three alpha molecules bear mature-type N
linked saccharide chains including Nacetyl galactosamine residues but none of
them contains O-linked oligosaccharide. The free alphaA isoform, more than the
oLHalpha, was able to stimulate PRL release from ovine foetal pituitary explants
in culture, whereas the free alphaB isoform displayed no activity. Moreover, the
free alphaA and alphaB isoforms were able to recombine with the ovine LH beta
subunit (oLHbeta). The free alphaB/oLHbeta, and the oLHalpha/oLHbeta dimer were 4
fold more active than the free alphaA/oLHbeta dimer in a specific LH
radioreceptor assay and in the stimulation of testosterone release from rat
Leydig cells. The present study demonstrates that the two free alpha isoforms of
ovine glycoprotein hormones exhibit distinct efficiencies in stimulating PRL
release from ovine foetal pituitaries. Moreover, despite their identical ability
to recombine with the oLHbeta, the free alpha isoform, which is the most
efficient on PRL release, is the least efficient in conferring LH activity on the
alpha/beta dimer.
PMID- 10694369
TI - hCGbeta core fragment is a metabolite of hCG: evidence from infusion of
recombinant hCG.
AB - The availability of recombinant human chorionic gonadotrophin (r-hCG) has allowed
us to measure its metabolic and renal clearance rates and to study the origin of
the beta core fragment of hCG (hCGbetacf). Serum and urine samples were collected
from six subjects, after an intravenous injection of 2 mg (equivalent to 44 000
IU Urinary hCG) r-hCG, and assayed for hCG and the beta subunit (hCGbeta). Urine
from four of the subjects was also subjected to gel chromatography and assayed
for hCGbetacf and hCG. r-hCG, administered as an intravenous dose, was
distributed, initially in a volume of 3.4+/-0.7 l (mean+/-s.d.) and then in 6.5+/
1.15 l at steady-state. The disappearance of r-hCG from serum was bi-exponential,
with an initial half-life of 4.5+/-0.7 h and a terminal half-life of 29.0+/-4.6
h. The mean residence time was 28. 6+/- 3.6 h and the total systemic clearance
rate of r-hCG was 226+/-18 ml/h. The renal clearance rate was 28.75+/-6.2 ml/h
(mean+/-s.d). hCGbetacf was detected in all urine samples collected at 6 h
intervals. Over the 138 h period of urine collection, 12.9% (range 10.1-17.3% )
of r-hCG injected was recovered as the intact molecule and 1.7% (range 0.8-2.9%)
was recovered as the hCGbetacf, in 4 subjects. The molar ratio of hCGbetacf to
hCG in urine increased from 3.1+/-1.7%, on day 1, to 76+/-34.3% (mean+/-s.e.m.)
on day 5, after r-hCG infusion, suggesting that hCGbetacf is a metabolic product
of the infused r-hCG.
PMID- 10694370
TI - Stable overexpression of the glucose-6-phosphatase catalytic subunit attenuates
glucose sensitivity of insulin secretion from a mouse pancreatic beta-cell line.
AB - Glucose-6-phosphatase (G-6-Pase) hydrolyzes glucose-6-phosphate to glucose,
reciprocal with the so-called glucose sensor, glucokinase, in pancreatic beta
cells. To study the role of G-6-Pase in glucose-stimulated insulin secretion from
beta cells, we have introduced rat G-6-Pase catalytic subunit cDNA and have
established permanent clones with 3-, 7- and 24-fold G-6-Pase activity of the
mouse beta-cell line, MIN6. In these clones, glucose usage and ATP production in
the presence of 5.5 or 25 mM glucose were reduced, and glucose-stimulated insulin
secretion was decreased in proportion to the increased G-6-Pase activity. In
addition, insulin secretory capacity in response to d-fructose and pyruvate was
unchanged; however, 25 mM glucose-stimulated insulin secretion and intracellular
calcium response were completely inhibited. In the clone with 24-fold G-6-Pase
activity, changes in intracellular NAD(P)H autofluorescence in response to 25 mM
glucose were reduced, but the changes with 20 mM fructose and 20 mM pyruvate were
not altered. Stable overexpression of G-6-Pase in beta cells resulted in
attenuation of the overall glucose-stimulated metabolic responses corresponding
to the degree of overexpression. This particular experimental manipulation shows
that the possibility exists of modulating glucose-stimulated insulin release by
thoroughly altering glucose cycling at the glucokinase/G-6-Pase step.
PMID- 10694371
TI - Transmembrane protein tyrosine phosphatase IA-2 (ICA512) is expressed in human
midgut carcinoids but is not detectable in normal enterochromaffin cells.
AB - A potential upregulation of receptor type protein tyrosine phosphatase IA-2
(ICA512) expression was detected by differential display and investigated in
midgut carcinoid tumours. Normal intestine tissue and tumour tissue from 13
midgut carcinoid patients were studied by in situ hybridisation using an IA-2
ribonucleotide probe and confocal microscopy using specific IA-2 antibodies.
Previously, it had been shown that IA-2 is located in the secretory granules of
virtually all neuroendocrine cells. However, we found that IA-2 was not
detectable in resting normal enterochromaffin (EC) cells of the small intestine,
while high expression of IA-2 mRNA and protein was confirmed in both primary and
metastatic carcinoid tissue. This difference in expression was not observed with
chromogranin A or serotonin, two secretory granule hormones known to be expressed
in EC cells, indicating that IA-2 was seemingly not necessary for the basal
production and packaging of these hormones. When comparing patients receiving
biotherapy before operation with untreated patients, we found expression of IA-2
to be lower in tumours from patients that had been treated with a combination of
alpha-interferon and the somatostatin analogue, octreotide. There was no
correlation between IA-2 expression and proliferation rates as measured by
immunohistochemistry with antibodies against the Ki 67 antigen. Furthermore, we
show that IA-2 is co-localised with serotonin in carcinoid tumours as well as in
the pancreatic tumour cell line, BON1, which is interesting as serotonin
secretion rate is presumably higher in tumour cells than in resting EC cells.
Taken together, these findings may indicate a role for IA-2 in the later stages
of the regulated secretory process.
PMID- 10694372
TI - Apoptosis during goitre involution - the role of Bcl-2.
AB - Goitrogenesis is accompanied by hyperplasia and hypertrophy and involves tissue
remodelling and angiogenesis. During the involution of the goitre there must be
removal of this increased thyroid volume, in addition to further remodelling,
which may involve apoptosis. We investigated apoptosis in the involuting rat
thyroid using male Fisher rats that were on a goitrogenic regimen for 14 days and
then returned to a normal diet. Thyroid weights increased fourfold with the
goitrogenic regimen. During involution, the largest decrease in weight was
between day 2 and day 4 after withdrawal of treatment. After 34 days of
involution, the thyroid weight plateaued, but had not returned to control values.
High levels of Bcl-2 immunoreactivity were observed in normal and goitrous rat
thyroids. These high levels were significantly reduced at 2 days of involution,
after which high levels of Bcl-2 immunoreactivity returned. In situ end-labelling
of apoptotic cells showed that there was an increase in the number of cells
undergoing DNA fragmentation during goitrogenesis (1.0+/-0.8 cells/100 cells,
n=9) compared with controls, in which no positive staining was observed. After 2
days of goitrogen withdrawal, there was a further fourfold increase in the number
of in situ end-labelled cells (day 16: 4.1+/-1.7, n=9). Numbers of positive cells
returned to low levels after 4 days of involution (day 18: 0.3+/-0.8, n=9). Using
antiserum to apoptosis-specific protein, we found increased immunoreactivity
during goitrogenesis and after 2 days of involution that was localised
predominantly with the stromal and vascular tissue at both time points. The data
show that rapid downregulation of Bcl-2 accompanies thyroid involution, which
involves increased levels of apoptosis within the stromal compartment.
PMID- 10694373
TI - Modulation of uncoupling protein 2 and uncoupling protein 3: regulation by
denervation, leptin and retinoic acid treatment.
AB - We recently reported that the leptin-induced increase in uncoupling protein 1
(UCP1) mRNA in brown adipose tissue (BAT) is prevented by the denervation of BAT.
We also reported that retinoic acid (RA) increases UCP1 mRNA in BAT. To extend
these finding to UCP2 and UCP3 in BAT, we examined UCP2 and UCP3 mRNA after
unilateral denervation of BAT, as well as after leptin, beta(3)-adrenergic
agonist, RA, and glucocorticoid administration to rats. UCP3 mRNA was 20% less in
the denervated compared with the intact BAT, whereas UCP2 mRNA was unchanged with
denervation. The beta(3)-adrenergic agonist, CGP-12177 (0.75 mg/kg), increased
UPC3 mRNA by 40% in the innervated and by 85% in the denervated BAT. Leptin (0.9
mg/day for 3 days) increased both UCP2 and UCP3 mRNA by 30% in the innervated
and, surprisingly, in the denervated BAT. RA (7.5 mg/kg) increased UCP1 mRNA but
decreased UCP2 and UCP3 mRNA by 50%, whereas methylprednisolone (65 mg/kg, two
doses 24 h apart) suppressed all three uncoupling proteins by greater than 60%.
The present findings indicate that: sympathetic innervation is necessary to
maintain basal levels of UCP3 mRNA; beta(3)-adrenergic agonist stimulation
induces UCP3 mRNA; leptin induces UCP2 and UCP3 mRNA and this induction is not
dependent on sympathetic innervation; RA increases UCP1 but decreases UCP2 and
UCP3 mRNA; and methylprednisolone suppresses UCP1, UCP2, and UCP3 mRNA equally.
These data suggest that there are distinct patterns of regulation between UCP1,
UCP2, and UCP3, and there may be at least two modes by which leptin could
modulate thermogenesis in BAT; first, by increasing sympathetic stimulation of
BAT and induction of UCP1 mRNA and, secondly, by increasing UCP2 and UCP3 mRNA by
a mechanism independent of sympathetic stimulation.
PMID- 10694374
TI - Regulation of vitamin D-1alpha-hydroxylase and -24-hydroxylase expression by
dexamethasone in mouse kidney.
AB - We investigated the effects of dexamethasone on vitamin D-1alpha-hydroxylase and
24-hydroxylase expression and on vitamin D receptor (VDR) content in the kidneys
of mice fed either a normal (NCD) diet or a calcium- and vitamin D-deficient
(LCD) diet for 2 weeks. For the last 5 days mice received either vehicle or
dexamethasone (2 mg/kg per day s.c.). Dexamethasone significantly increased
plasma calcium concentrations without changing plasma concentrations of 1,25
dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) in both NCD and LCD groups. Northern blot
and enzyme activity analyses in NCD mice revealed that dexamethasone increased
renal VDR mRNA expression modestly and greatly increased 24-hydroxylase mRNA
abundance and enzyme activity, but did not affect 1alpha-hydroxylase mRNA
abundance and enzyme activity. In mice fed an LCD diet, dexamethasone increased
renal VDR mRNA expression 1.5-fold, decreased 1alpha-hydroxylase mRNA abundance
(52%) and activity (34%), and markedly increased 24-hydroxylase mRNA abundance
(16-fold) and enzyme activity (9-fold). Dexamethasone treatment did not alter
functional VDR number (B(max) 125-141 fmol/mg protein) or ligand affinity (K(d)
0.13-0.10 nM) in LCD mice. Subcutaneous injections of 1,25(OH)(2)D(3) (0.24
nmol/kg per day for 5 days) into NCD mice strongly increased renal 24-hydroxylase
mRNA abundance and enzyme activity, while there was no effect of dexamethasone on
renal 24-hydroxylase expression in these mice. This may be due to overwhelming
induction of 24-hydroxylase by 1,25(OH)(2)D(3). These findings suggest that
glucocorticoid-induced osteoporosis is caused by direct action of the steroids on
bone, and the regulatory effect of glucocorticoids on renal 25-hydroxyvitamin
D(3) metabolism may be less implicated in the initiation and progression of the
disease.
PMID- 10694375
TI - Neonatal handling permanently alters hypothalamic-pituitary- adrenal axis
function, behaviour, and body weight in boars.
AB - Neonatal handling permanently alters hypothalamic- pituitary-adrenal axis (HPA)
function in rats. In the rat, this treatment increases hippocampal glucocorticoid
receptors (GR) and dampens plasma ACTH and corticosterone responses to stressors.
The objectives of this study were to determine whether neonatal handling of pigs
would effect permanent changes in plasma corticosteroid binding capacity (CBG),
basal or stressor-induced plasma cortisol and ACTH concentrations, brain or
pituitary GR levels, dexamethasone suppression of plasma cortisol and ACTH
concentrations, behaviour in an open field-test pen, and body weights. Twelve
litters of pigs were randomly assigned to either neonatal handling or no
disturbance. Handled litters were removed from the farrowing crate for 10 min per
day for the first 14 days of life. Male pigs were kept for the study and the
boars were weighed monthly. At 7 months of age, boars were tested for locomotory
behaviour in an open field-test pen. The boars were implanted with indwelling ear
vein catheters and blood samples were obtained basally, during and after
application of a nose snare, and after 0.04 mg/kg dexamethasone. Boars were
killed and blood samples were obtained and the brain and pituitary glands
collected. Handled boars had greater (P<0.05) plasma CBG binding and lower basal
total (P<0.05) and calculated free (P<0.03) plasma cortisol concentrations. No
significant differences between treatments were found in plasma ACTH or cortisol
responses to a nose-snare stressor; however, when killed, handled boars had
greater (P<0.02) plasma ACTH concentrations. Handled and non-handled boars did
not differ in plasma ACTH or cortisol responses to dexamethasone. There was no
treatment effect on GR expression in the pituitary gland, frontal cortex,
hippocampus, or hypothalamus. Behaviourally, the handled boars had higher
(P<0.03) locomotor scores over inner squares and a lower (P<0.05) ratio of
outer:inner squares entered in open field-tests. During the first 7 months of
life, body weights were lower (P<0.004) for handled boars. In conclusion,
neonatal handling permanently altered HPA function in pigs, but in a manner
dissimilar to that found in the rat. These changes induced in the pig were not
beneficial for commercial production with respect to body weight.
PMID- 10694376
TI - IGF-I/IGFBPs system response to endotoxin challenge in sheep.
AB - Endotoxin (LPS), a membrane component of gram-negative bacteria produces multiple
endocrine and metabolic effects that mimic those seen in acute sepsis. It induces
species-dependent alterations of the growth hormone (GH) axis that may
participate in the shift of the metabolism towards catabolic events. Humans and
sheep show increased GH secretion in response to LPS, as opposed to rats, which
have been the most studied. The purpose of our work was to evaluate the effects
in intact rams of an acute intravenous administration of a high dose of LPS on
the insulin-like growth factor (IGF)-I/IGF-binding proteins (IGFBPs) system and
to analyse the temporal relationship of GH axis changes with those of several
hormonal and metabolic parameters such as somatostatin, cortisol, insulin, and
glucose. LPS induced a late moderate decrease of total IGF-I plasma levels
following a 5-h steady-state period (-26.6+/-4. 2%, P<0.05, 9 h after LPS),
despite a biphasic and sustained increase of GH secretion in the same animals
(2.48+/-0.39 ng/ml 2 h after LPS and 2.7+/-0.37 ng/ml 5 h after LPS vs 0.77+/
0.10 before LPS; Briard et al. 1998a). Western ligand blot analysis in IGFBPs
showed an early short-lasting increase in IGFBP-1 (188.8+/-39% P<0. 05, 3 h after
LPS). No significant change was seen for either IGFBP-2, -3 or -4. We observed a
marked and sustained increase in cortisol (128.18+/-7.21 ng/ml 3 h after LPS, vs
21.17+/-4.22 before LPS). Insulin also increased (27.69+/-3.90 microU/ml 3 h
after LPS, vs 13.48+/-1.69 before LPS) and its burst coincided with that of IGFBP
1. Moderately decreased IGF-I and increased IGFBP-1 plasma levels contrasted with
the sustained increase in GH secretion that we recently described, thereby
suggesting that endotoxin causes a state of resistance to GH. This may be
exacerbated by reduced IGF-I bioavailability and/or action, and which may
participate in the pathophysiology of the catabolic state seen in sepsis. The
temporal analysis of hormone responses suggests that endotoxin-induced
alterations of the IGF-I/IGFBPs system may involve the prolonged and substantial
somatostatin rise that we recently demonstrated, together with an increase in
glucocorticoid and cytokine as more generally assumed.
PMID- 10694377
TI - Amino acid regulation of gene transcription of rat insulin-like growth factor
binding protein-1.
AB - To investigate the molecular mechanisms of increased transcription of the insulin
like growth factor-binding protein-1 (IGFBP-1) gene in dietary protein-deprived
animals, the cis-acting sequence that is involved in this regulation was
analyzed. We first showed that IGFBP-1 gene transcription was up-regulated by
amino acid deprivation in cultured liver cell lines: H4IIE and HuH-7. Since HuH-7
cells showed a greater increase in IGFBP-1 mRNA in response to amino acid
deprivation, this cell line was used in further experiments. Using a promoter
function assay, we found that up-regulation of promoter activity responding to
amino acid deprivation was abolished by deleting the region between -112 and -81
bp from the cap site from the gene construct. This cis-acting region includes the
insulin-responsive element (IRE) and glucocorticoid responsive element (GRE) of
IGFBP-1. In summary, the present observation suggests that the 32-bp (-112 to
81) in the IGFBP-1 gene 5' promoter region is involved in the induction of the
IGFBP-1 gene in response to amino acid deprivation.
PMID- 10694378
TI - Simultaneous binding of two DNA duplexes to the NtrC-enhancer complex studied by
two-color fluorescence cross-correlation spectroscopy.
AB - The transcription activator protein NtrC (nitrogen regulatory protein C, also
termed NR(I)) can catalyze the transition of Escherichia coli RNA polymerase
complexed with the sigma(54) factor (RNAP x sigma(54)) from the closed complex
(RNAP x sigma(54) bound at the promoter) to the open complex (melting of the
promoter DNA). This process involves phosphorylation of NtrC (NtrC-P), assembly
of an octameric NtrC-P complex at the enhancer DNA sequence, interaction of this
complex with promoter-bound RNAP x sigma(54) via DNA looping, and hydrolysis of
ATP. Here it is demonstrated by two-color fluorescence cross-correlation
spectroscopy measurements of 6-carboxyfluorescein and 6-carboxy-X-rhodamine
labeled DNA oligonucleotide duplexes that the NtrC-P complex can bind two DNA
duplexes simultaneously. This suggests a model for the conformation of the looped
intermediate that is formed between NtrC-P and RNAP. sigma(54) at the glnAp2
promoter during the activation process.
PMID- 10694379
TI - Fucoidan-dependent conformational changes in annexin II tetramer.
AB - Fucoidan, a sulfated fucopolysaccharide, mimics the fucosylated glycans of
glycoproteins and has therefore been used as a probe for investigating the role
of membrane polysaccharides in cell-cell adhesion. In the present report we have
characterized the interaction of fucoidan with the Ca(2+)- and phospholipid
binding protein annexin II tetramer (AIIt). AIIt bound to fucoidan with an
apparent K(d) of 1.24 +/- 0.69 nM (mean +/- SD, n = 3) with a stoichiometry of
0.010 +/- 0.001 mol of fucoidan/mol of AIIt (mean +/- SD, n = 3). The binding of
fucoidan to AIIt was Ca(2+)-independent. Furthermore, in the presence but not the
absence of Ca(2+), the binding of fucoidan to AIIt caused a decrease in the alpha
helical content from 32% to 7%. A peptide corresponding to a region of the p36
subunit of AIIt, F(306)-S(313), which contains a Cardin-Weintraub consensus
sequence for heparin binding, was shown to undergo a conformational change upon
fucoidan binding. This suggests that heparin and fucoidan bound to this region of
AIIt. The binding of fucoidan but not heparin by AIIt also inhibited the ability
of AIIt to bind to and aggregate phospholipid liposomes. These results suggest
that the binding of AIIt to the carbohydrate conjugates of certain membrane
glycoproteins may have profound effects on the structure and biological activity
of AIIt.
PMID- 10694380
TI - Two homologues encoding human UDP-glucose:glycoprotein glucosyltransferase differ
in mRNA expression and enzymatic activity.
AB - UDP-glucose:glycoprotein glucosyltransferase (UGT) is a soluble protein of the
endoplasmic reticulum (ER) that operates as a gatekeeper for quality control by
preventing transport of improperly folded glycoproteins out of the ER. We report
the isolation of two cDNAs encoding human UDP-glucose:glycoprotein
glucosyltransferase homologues. HUGT1 encodes a 1555 amino acid polypeptide that,
upon cleavage of an N-terminal signal peptide, is predicted to produce a soluble
173 kDa protein with the ER retrieval signal REEL. HUGT2 encodes a 1516 amino
acid polypeptide that also contains a signal peptide and the ER retrieval signal
HDEL. HUGT1 shares 55% identity with HUGT2 and 31-45% identity with Drosophila,
Caenorhabditis elegans, and Schizosaccharomyces pombe homologues, with most
extensive conservation of residues in the carboxy-terminal fifth of the protein,
the proposed catalytic domain. HUGT1 is expressed as multiple mRNA species that
are induced to similar extents upon disruption of protein folding in the ER. In
contrast, HUGT2 is transcribed as a single mRNA species that is not induced under
similar conditions. HUGT1 and HUGT2 mRNAs are broadly expressed in multiple
tissues and differ slightly in their tissue distribution. The HUGT1 and HUGT2
cDNAs were expressed by transient transfection in COS-1 monkey cells to obtain
similar levels of protein localized to the ER. Extracts from HUGT1-transfected
cells displayed a 27-fold increase in the transfer of [(14)C]glucose from UDP
[(14)C]glucose to denatured substrates. Despite its high degree of sequence
identity with HUGT1, the expressed recombinant HUGT2 protein was not functional
under the conditions optimized for HUGT1. Site-directed alanine mutagenesis
within a highly conserved region of HUGT1 identified four residues that are
essential for catalytic function.
PMID- 10694381
TI - Role of the loop containing residue 115 in the induced-fit mechanism of the
bacterial cell wall biosynthetic enzyme MurA.
AB - The induced-fit mechanism in Enterobacter cloacae MurA has been investigated by
kinetic studies and X-ray crystallography. The antibiotic fosfomycin, an
irreversible inhibitor of MurA, induced a structural change in UDP-N
acetylglucosamine (UDPGlcNAc)-liganded enzyme with a time dependence similar to
that observed for the inactivation progress. The mechanism of action of
fosfomycin on MurA appeared to be of the bimolecular type, the overall rate
constants of inactivation and structural change being = 104 M(-1) s(-1) and = 85
M(-1) s(-1), respectively. Fosfomycin as well as the second MurA substrate,
phosphoenolpyruvate (PEP), are known to interact with the side chain of Cys115.
Like wild-type MurA, the catalytically inactive single-site mutant protein
Cys115Ser structurally interacted with UDPGlcNAc in a rapidly reversible
reaction. However, in contrast to wild-type enzyme, binding of PEP to mutant
protein induced a rate-limited, biphasic structural change. Fosfomycin did not
affect the structure of the mutant protein. The crystal structure of unliganded
Cys115Ser MurA at 1.9 A resolution revealed that the overall conformation of the
loop comprising residues 112-121 is not influenced by the mutation. However,
other than Cys115 in wild-type MurA, Ser115 exhibits two distinct side-chain
conformations. A detailed view on the loop revealed the existence of an elaborate
hydrogen-bonding network mainly supplied by water molecules, presumably
stabilizing its conformation in the unliganded state. The comparison between the
known crystal structures of MurA, together with the kinetic data obtained,
suggest intermediate conformational states in the MurA reaction, in which the
loop undergoes multiple structural changes upon ligand binding.
PMID- 10694382
TI - Determination of metal ion binding sites within the hairpin ribozyme domains by
NMR.
AB - Cations play an important role in RNA folding and stabilization. The hairpin
ribozyme is a small catalytic RNA consisting of two domains, A and B, which
interact in the transition state in an ion-dependent fashion. Here we describe
the interaction of mono-, di-, and trivalent cations with the domains of the
ribozyme, as studied by homo- and heteronuclear NMR spectroscopy. Paramagnetic
line broadening, chemical shift mapping, and intermolecular NOEs indicate that
the B domain contains four to five metal binding sites, which bind Mn(2+),
Mg(2+), and Co(NH(3))(6)(3+). There is no significant structural change in the B
domain upon the addition of Co(NH(3))(6)(3+) or Mg(2+). No specific monovalent
ion binding sites exist on the B domain, as determined by (15)NH(4)(+) binding
studies. In contrast to the B domain, there are no observable metal ion
interactions within the internal loop of the A domain. Model structure
calculations of Mn(2+) interactions at two sites within the B domain indicate
that the binding sites comprise major groove pockets lined with functional groups
oriented so that multiple hydrogen bonds can be formed between the RNA and
Mn(H(2)O)(6)(2+) or Co(NH(3))(6)(3+). Site 1 is very similar in geometry to a
site within the P4-P6 domain of the Tetrahymena group I intron, while site 2 is
unique among known ion binding sites. The site 2 ion interacts with a
catalytically essential nucleotide and bridges two phosphates. Due to its
location and geometry, this ion may play an important role in the docking of the
A and B domains.
PMID- 10694383
TI - Critical role of tyrosine 277 in the ligand-binding and transactivating
properties of retinoic acid receptor alpha.
AB - Retinoic acid receptors specifically bind all-trans-retinoic acid (RA) and
function as RA-inducible transcriptional regulatory factors. Binding of RA to
RARalpha, beta, and gamma is sensitive to nitration with tetranitromethane, a
tyrosine-specific modifying reagent. To identify tyrosine residue(s) that are
important for RA binding, we carried out chemical modification experiments with
purified RARalpha ligand-binding domain (RARalpha-LBD) subjected to partial acid
hydrolysis and selective proteolysis. The chemically modified peptides containing
each of the three Tyr residues present in the RARalpha-LBD sequence were then
analyzed and identified by high-performance liquid chromatography coupled to
electrospray ionization mass spectrometry (HPLC/ESI-MS). We found that RA binding
to RARalpha-LBD protected Tyr(277)-containing peptides from nitration. Protection
of Tyr(277) could result either from direct masking by the bound ligand or from
ligand-induced changes in receptor conformation and tyrosine accessibility. The
role of Tyr residues was further documented by site directed mutagenesis using
three site-specific RARalpha mutants: Y208A, Y277A, and Y362A. The affinity for
RA of these mutant receptors was in the range of that of the wild-type protein,
except for the Y277A receptor mutant, which displays a 15-20-fold reduction in
affinity and transactivation activity for RA. Whereas mutation of Tyr(277) into
alanine had a variable effect on different agonists and antagonists binding, it
caused a dramatic decrease of retinoid-dependent transactivation activity. This
later effect was also observed with mutation of Tyr(277) into phenylalanine. It
is unlikely that major conformational changes are responsible for the lower
affinity of RA binding and RA-dependent transactivation since these mutants
displayed wild-type dimerization and DNA-binding activities. Limited proteolysis
revealed that upon ligand binding, the Y277A mutant induced a conformational
change slightly different from that obtained with the wild-type protein. These
data could suggest that Tyr(277) play a critical role in the ligand-induced
conformational changes required for the activation of RARalpha.
PMID- 10694384
TI - Evaluation by site-directed mutagenesis of aspartic acid residues in the metal
site of pig heart NADP-dependent isocitrate dehydrogenase.
AB - Pig heart NADP-dependent isocitrate dehydrogenase requires a divalent metal
cation for catalysis. On the basis of affinity cleavage studies [Soundar and
Colman (1993) J. Biol. Chem. 268, 5267] and analysis of the crystal structure of
E. coli NADP-isocitrate dehydrogenase [Hurley et al. (1991) Biochemistry 30,
8671], the residues Asp(253), Asp(273), Asp(275), and Asp(279) were selected as
potential ligands of the divalent metal cation in the pig heart enzyme. Using a
megaprimer PCR method, the Asp at each of these positions was mutated to Asn. The
wild-type and mutant enzymes were expressed in Escherichia coli and purified.
D253N has a specific activity, K(m) values for Mn(2+), isocitrate, and NADP, and
also a pH-V(max) profile similar to those of the wild-type enzyme. Thus, Asp(253)
is not involved in enzyme function. D273N has an increased K(m) for Mn(2+) and
isocitrate with a specific activity 5% that of wild type. The D273N mutation also
prevents the oxidative metal cleavage seen with Fe(2+) alone in the wild-type
enzyme. As compared to wild type, D275N has greatly increased K(m) values for
Mn(2+) and isocitrate, with a specific activity <0.1% that of wild type, and a
large increase in pK(a) for the enzyme-substrate complex. D279N has only small
increases in K(m) for Mn(2+) and isocitrate, but a specific activity <0.1% that
of wild type and a major change in the shape of its pH-V(max) profile. These
results suggest that Asp(273) and Asp(275) contribute to metal binding, whereas
Asp(279), as well as Asp(275), is critical for catalysis. Asp(279) may function
as the catalytic base. Using the Modeler program of Insight II, a structure for
porcine NADP-isocitrate dehydrogenase was built based on the X-ray coordinates of
the E. coli enzyme, allowing visualization of the metal-isocitrate site.
PMID- 10694385
TI - HIV-1 protease inhibitors: enthalpic versus entropic optimization of the binding
affinity.
AB - Existing experimental as well as computational screening methods select potential
ligands or drug candidates on the basis of binding affinity. Since the binding
affinity is a function of the enthalpy (DeltaH) and entropy (DeltaS) changes, it
is apparent that improved binding can be achieved in different ways: by
optimizing DeltaH, DeltaS, or a combination of both. However, the behavior of
enthalpically or entropically optimized inhibitors is fundamentally different,
including their response to mutations that may elicit drug resistance. In the
design of HIV-1 protease inhibitors, high binding affinity has usually been
achieved by preshaping lead compounds to the geometry of the binding site and by
incorporating a high degree of hydrophobicity. The thermodynamic consequence of
that approach is that the binding affinity of the resulting inhibitors becomes
entropically favorable but enthalpically unfavorable. Specifically, the resulting
high binding affinity is due to an increased solvation entropy (hydrophobic
effect) combined with a reduced loss of conformational entropy of the inhibitor
upon binding (structural rigidity). Here we report that tripeptide inhibitors
derived from the transframe region of Gag-Pol (Glu-Asp-Leu and Glu-Asp-Phe) bind
to the HIV-1 protease with a favorable enthalpy change. This behavior is
qualitatively different from that of known inhibitors and points to new
strategies for inhibitor design. Since the binding affinities of enthalpically
favorable and enthalpically unfavorable inhibitors have opposite temperature
dependence, it is possible to design fast screening protocols that simultaneously
select inhibitors on the basis of affinity and enthalpy.
PMID- 10694386
TI - Crystal structure and site-specific mutagenesis of pterin-bound human
phenylalanine hydroxylase.
AB - The crystal structure of the dimeric catalytic domain (residues 118-424) of human
PheOH (hPheOH), cocrystallized with the oxidized form of the cofactor (7,8
dihydro-L-biopterin, BH(2)), has been determined at 2.0 A resolution. The pterin
binds in the second coordination sphere of the catalytic iron (the C4a atom is
6.1 A away), and interacts through several hydrogen bonds to two water molecules
coordinated to the iron, as well as to the main chain carbonyl oxygens of Ala322,
Gly247, and Leu249 and the main chain amide of Leu249. Some important
conformational changes are seen in the active site upon pterin binding. The loop
between residues 245 and 250 moves in the direction of the iron, and thus allows
for several important hydrogen bonds to the pterin ring to be formed. The pterin
cofactor is in an ideal orientation for dioxygen to bind in a bridging position
between the iron and the pterin. The pterin ring forms an aromatic pi-stacking
interaction with Phe254, and Tyr325 contributes to the positioning of the pterin
ring and its dihydroxypropyl side chain by hydrophobic interactions. Of
particular interest in the hPheOH x BH(2) binary complex structure is the finding
that Glu286 hydrogen bonds to one of the water molecules coordinated to the iron
as well as to a water molecule which hydrogen bonds to N3 of the pterin ring.
Site-specific mutations of Glu286 (E286A and E286Q), Phe254 (F254A and F254L),
and Tyr325 (Y325F) have confirmed the important contribution of Glu286 and Phe254
to the normal positioning of the pterin cofactor and catalytic activity of
hPheOH. Tyr325 also contributes to the correct positioning of the pterin, but has
no direct function in the catalytic reaction, in agreement with the results
obtained with rat TyrOH [Daubner, S. C., and Fitzpatrick, P. F. (1998)
Biochemistry 37, 16440-16444]. Superposition of the binary hPheOH.BH(2) complex
onto the crystal structure of the ligand-free rat PheOH (which contains the
regulatory and catalytic domains) [Kobe, B., Jennings, I. G., House, C. M.,
Michell, B. J., Goodwill, K. E., Santarsiero, B. D., Stevens, R. C., Cotton, R.
G. H., and Kemp, B. E. (1999) Nat. Struct. Biol. 6, 442-448] reveals that the C2'
hydroxyl group of BH(2) is sufficiently close to form hydrogen bonds to Ser23 in
the regulatory domain. Similar interactions are seen with the hPheOH.adrenaline
complex and Ser23. These interactions suggest a structural explanation for the
specific regulatory properties of the dihydroxypropyl side chain of BH(4)
(negative effector) in the full-length enzyme in terms of phosphorylation of
Ser16 and activation by L-Phe.
PMID- 10694387
TI - Escherichia coli methionyl-tRNA formyltransferase: role of amino acids conserved
in the linker region and in the C-terminal domain on the specific recognition of
the initiator tRNA.
AB - The formylation of initiator methionyl-tRNA by methionyl-tRNA formyltransferase
(MTF) is important for the initiation of protein synthesis in eubacteria. We are
studying the molecular mechanisms of recognition of the initiator tRNA by
Escherichia coli MTF. MTF from eubacteria contains an approximately 100-amino
acid C-terminal extension that is not found in the E. coli glycinamide
ribonucleotide formyltransferase, which, like MTF, use N(10)
formyltetrahydrofolate as a formyl group donor. This C-terminal extension, which
forms a distinct structural domain, is attached to the N-terminal domain through
a linker region. Here, we describe the effect of (i) substitution mutations on
some nineteen basic, aromatic and other conserved amino acids in the linker
region and in the C-terminal domain of MTF and (ii) deletion mutations from the C
terminus on enzyme activity. We show that the positive charge on two of the
lysine residues in the linker region leading to the C-terminal domain are
important for enzyme activity. Mutation of some of the basic amino acids in the C
terminal domain to alanine has mostly small effects on the kinetic parameters,
whereas mutation to glutamic acid has large effects. However, the deletion of 18,
20, or 80 amino acids from the C-terminus has very large effects on enzyme
activity. Overall, our results support the notion that the basic amino acid
residues in the C-terminal domain provide a positively charged channel that is
used for the nonspecific binding of tRNA, whereas some of the amino acids in the
linker region play an important role in activity of MTF.
PMID- 10694388
TI - NBD-isocolcemid-tubulin interaction: a novel one-step reaction involving no
conformational adjustment of reactants.
AB - Isocolcemid, a colcemid analogue in which the positions of the C-ring methoxy and
carbonyl are exchanged, is virtually inactive in binding to tubulin and
inhibiting the formation of microtubule assembly. We have found that the
substitution of a NBD group in the side chain of the B-ring of isocolcemid can
reverse the effect of these structural alterations (at the C-ring) and the newly
synthesized NBD-isocolcemid restores the lost biological activity. It inhibits
microtubule assembly with an IC(50) of 12 microM and competes efficiently with
[(3)H]colchicine, for binding to tubulin. NBD-isocolcemid has two binding sites
on tubulin; one is characterized by fast binding, whereas the binding to the
other site is slow. These two sites are independent and unrelated to each other.
Colchicine and its analogues compete with NBD-isocolcemid for the slow site.
Association and dissociation rate constants for the fast site, obtained from the
stopped-flow measurements, are (7.37 +/- 0. 70) x 10(5) M(-1) s(-1) and 7.82 +/-
2.74 s(-1), respectively. While the interaction of colchicine and its analogues
with tubulin involves two steps, NBD-isocolcemid binding to tubulin at the slow
site has been found to be a one-step reaction. This is evident from the linear
dependence of the observed rate constant (k(obs)) with both NBD-isocolcemid and
tubulin concentrations. The interaction of NBD-isocolcemid with tubulin does not
involve the conformational change of NBD-isocolcemid, as is evident from the
unchanged CD spectra of the drug. The absence of enhanced GTPase activity of
tubulin and the native-like protease cleavage pattern of the NBD-isocolcemid
tubulin complex suggest an unaltered conformation of tubulin upon NBD-isocolcemid
binding to it as well. Implications of this on the mechanism of polymerization
inhibition have been discussed.
PMID- 10694389
TI - Neighboring aliphatic/aromatic side chain interactions between residues 9 and 10
in gramicidin channels.
AB - The interactions between an aliphatic or phenyl side chain and an indole ring in
a phospholipid environment were investigated by synthesizing and characterizing
gramicidins in which Trp(9) was ring-labeled and D-Leu(10) was replaced by D-Val,
D-Ala, or D-Phe. All three analogues form conducting channels, with conductances
that are lower than that of gramicidin A (gA) channels. The channel lifetimes
vary by less than 50% from that of gA channels. Circular dichroism spectra and
size-exclusion chromatography show that the conformation of each analogue in
dimyristoylphosphatidylcholine (DMPC) vesicles is similar to the right-handed
beta(6.3)-helical conformation that is observed for gA. (2)H NMR spectra of
oriented samples in DMPC show large changes for the Trp(9) ring when residue 10
is modified, suggesting a steric interaction between D-Leu(10) and Trp(9), in
agreement with previous acylation studies (R. E. Koeppe II et al. (1995)
Biochemistry 34, 9299-9307). The outer quadrupolar splitting for Trp(9) is
unchanged with D-Phe(10), at approximately 153 kHz, but increases by
approximately 25 kHz with D-Val(10) and decreases by approximately 10 kHz with D
Ala(10). With D-Ala(10) or D-Val(10), the outer resonance splits into two in a
temperature-dependent manner. The NMR spectra indicate that the side chain
torsion angles chi1 and chi2 for Trp(9) change when residue 10 is substituted.
The changes in chi1 are small, in all cases less than 10 degrees, as is Deltachi2
when D-Ala(10) is introduced, but with D-Val(10) and D-Phe(10) Deltachi2 is at
least 25 degrees. We conclude that D-Leu(10) helps to stabilize an optimal
orientation of Trp(9) in gA channels in lipid bilayers and that changes in Trp
orientation alter channel conductance and lifetime without affecting the basic
channel fold.
PMID- 10694390
TI - Recognition of Dictyostelium discoideum lysosomal enzymes is conferred by the
amino-terminal carbohydrate binding site of the insulin-like growth factor
II/mannose 6-phosphate receptor.
AB - The insulin-like growth factor-II/mannose 6-phosphate receptor (IGF-II/MPR) is a
type I glycoprotein that mediates both the intracellular sorting of lysosomal
enzymes bearing mannose 6-phosphate (Man-6-P) residues to the lysosome and the
bioavailability of IGF-II. The extracytoplasmic region of the IGF-II/MPR contains
15 repeating domains; the two carbohydrate recognition domains (CRDs) have been
localized to domains 1-3 and 7-9, and the high-affinity IGF-II binding site maps
to domain 11. To characterize the carbohydrate binding properties of the IGF
II/MPR, regions of the receptor encompassing the individual CRDs were produced in
a baculovirus expression system. Characterization of the recombinant proteins
revealed that the pH optimum for carbohydrate binding is significantly more
acidic for the carboxyl-terminal CRD than for the amino-terminal CRD (i.e., pH
6.4-6.5 vs 6.9). Equilibrium binding studies demonstrated that the two CRDs
exhibit a similar affinity for Man-6-P. Furthermore, substitution of the
conserved arginine residue in domain 3 (R435) or in domain 9 (R1334) with alanine
resulted in a similar >1000-fold decrease in the affinity for the lysosomal
enzyme, beta-glucuronidase. In contrast, the two CRDs differ dramatically in
their ability to recognize the distinctive modifications (i.e., mannose 6-sulfate
and Man-6-P methyl ester) found on Dictyostelium discoideum lysosomal enzymes:
the amino-terminal CRD binds mannose 6-sulfate and Man-6-P methyl ester with a 14
55-fold higher affinity than the carboxyl-terminal CRD. Taken together, these
results demonstrate that the IGF-II/MPR contains two functionally distinct CRDs.
PMID- 10694391
TI - The interaction between the regulatory light chain domains on two heads is
critical for regulation of smooth muscle myosin.
AB - Recent findings have suggested that the interaction between the two heads is
critical for phosphorylation-dependent regulation of smooth muscle myosin. We
hypothesized that the interaction between the two regulatory light chains on two
heads of myosin dictates the regulation of myosin motor function. To evaluate
this notion, we engineered and characterized smooth muscle heavy meromyosin
(HMM), which is composed of one entire HMM heavy chain and one motor domain
truncated heavy chain containing the S2 rod and regulatory light chain (RLC)
binding site, as well as the bound RLC (SMDHMM). SMDHMM was inactive for both
actin-translocating activity and actin-activated ATPase activity in the
dephosphorylated state, demonstrating that the interaction between the two RLC
domains on the two heads and/or a motor domain and a RLC domain in a distinct
head is sufficient for the inhibition of smooth muscle myosin motor activity.
When phosphorylated, SMDHMM was activated for both actin-translocating activity
and actin-activated ATPase activity; however, these activities were lower than
those of double-headed HMM, implying partial release of inhibition by
phosphorylation in SMDHMM and/or cooperativity between the two heads of smooth
muscle myosin. The present results indicate that the RLC domain is critical for
phosphorylation-dependent regulation of smooth muscle myosin motor activity. On
the other hand, similar to double-headed HMM, SMDHMM showed both "folded" and
"extended" conformations, and the ratio of those conformations is dependent on
ionic strength, suggesting that the RLC domain is sufficient to regulate the
conformational transition in myosin.
PMID- 10694392
TI - Use of an altered sugar-nucleotide to unmask the transition state for alpha(2-
>6) sialyltransferase.
AB - Rat liver alpha(2-->6) sialyltransferase catalyzes the formation of a glycosidic
bond between N-acetylneuraminic acid and the 6-hydroxyl group of a galactose
residue at the nonreducing terminus of an oligosaccharide. This reaction has been
investigated through the use of the novel sugar-nucleotide donor substrate UMP
NeuAc. A series of UMP-NeuAc radioisotopomers were prepared by chemical
deamination of the corresponding CMP-NeuAc precursors. Kinetic isotope effects
(KIEs) on V/K were measured using mixtures of radiolabeled UMP-NeuAc's as the
donor substrate and N-acetyllactosamine as the acceptor. The secondary beta-(2)H
KIE was 1.218 +/- 0.010, and the primary (14)C KIE was 1.030 +/- 0.010. A large
inverse (3)H binding isotope effect of 0.944 +/- 0.010 was measured at the
terminal carbon of the NeuAc glycerol side chain. These KIEs observed using UMP
NeuAc are much larger than those previously measured with CMP-NeuAc [Bruner, M.,
and Horenstein, B. A. (1998) Biochemistry 37, 289-297]. Solvent deuterium isotope
effects of 1.3 and 2.6 on V/K and V(max) were observed with CMP-NeuAc as the
donor, and it is revealing that these isotope effects vanished with use of the
slow donor substrate UMP-NeuAc. Bell-shaped pH versus rate profiles were observed
for V(max) (pK(a) values = 5.5, 9.0) and V/K(UMP)(-)(NeuAc) (pK(a)values = 6.2,
9.0). The results are considered in terms of a mechanism involving an
isotopically sensitive conformational change which is independent of the glycosyl
transfer step. The isotope effects reveal that the enzyme-bound transition state
bears considerable charge on the N-acetylneuraminic acid residue, and this and
other features of this mechanism provide new directions for sialyltransferase
inhibitor design.
PMID- 10694393
TI - Engineering of Sulfolobus solfataricus HMG-CoA reductase to a form whose activity
is regulated by phosphorylation and dephosphorylation.
AB - There are two classes of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)
reductase: the class I enzymes of eukaryotes and some archaea, and the class II
enzymes of certain eubacteria. The activity of the class I Syrian hamster HMG-CoA
reductase is regulated by phosphorylation-dephosphorylation of Ser871.
Phosphorylation apparently prevents the active site histidine, His865, from
protonating the inhibitory coenzyme A thioanion prior to its release from the
enzyme. Structural evidence for this hypothesis is, however, lacking. The HMG-CoA
reductase of the thermophilic archaeon Sulfolobus solfataricus, whose stability
recommends it for physical studies, lacks both a phosphoacceptor serine and a
protein kinase recognition motif. Consequently, its activity is not regulated by
phosphorylation. We therefore employed site-directed mutagenesis to engineer an
appropriately located phosphoacceptor serine and cAMP-dependent protein kinase
recognition motif. Substitution of serine for Ala406, the apparent cognate of
hamster Ser871, and replacement of Leu403 and Gly404 by arginine created S.
solfataricus mutant enzyme L403R/G404R/A406S. The general properties of enzyme
L403R/G404R/A406S (K(m) values, V(max), optimal pH and temperature) were
essentially those of the wild-type enzyme. Exposure of enzyme L403R/G404R/A406S
to [gamma-(32)P]ATP and cAMP-dependent protein kinase was accompanied by
incorporation of (32)P(i) and by a parallel decrease in catalytic activity.
Subsequent treatment with a protein phosphatase released enzyme-bound (32)P(i)
and restored activity to pretreatment levels. The regulatory properties of enzyme
L403R/G404R/A406S thus match those of the hamster enzyme. Solution of the three
dimensional structures of the phospho and dephospho forms of this mutant enzyme
thus should reveal structural features critical for regulation of the activity of
a class I HMG-CoA reductase.
PMID- 10694394
TI - Stereochemistry of the enolization of scytalone by scytalone dehydratase.
AB - In D(2)O, scytalone exchanges its two C2 hydrogen atoms for deuterium atoms at
different rates. At pD 7.0 and 25 degrees C, half-lives for the exchanges are 0.8
and 10 days for the pro-S and pro-R hydrogens, respectively. The differential
exchange rates allow for the preparation of multiple scytalone samples (through
incubation of scytalone in D(2)O and then back exchanging with H(2)O) having
differential levels of deuterium enrichment at the C2 pro-S and pro-R positions.
From these samples, the stereochemical preference for hydrogen abstraction during
the dehydration reaction mediated by the enzyme scytalone dehydratase was
determined. At pH 7. 0, deuterium at the pro-S position has little effect on
enzyme catalysis, whereas deuterium at the pro-R position produces kinetic
isotope effects of 2.3 (25 degrees C), 5.1 (25 degrees C), and 6.7 (6.8 degrees
C) on k(cat), k(cat)/K(m), and the single-turnover rate, respectively. The
results are fully consistent with the enzyme catalyzing a syn elimination through
an E1cb-like mechanism. The syn elimination is compatible with the interactions
realized between a scytalone boat conformation and key active site residues as
modeled from multiple X-ray crystal structures of the enzyme in complexes with
inhibitors.
PMID- 10694395
TI - Kinetics and mechanism of the citrate synthase from the thermophilic archaeon
Thermoplasma acidophilum.
AB - The kinetics and mechanism of the citrate synthase from a moderate thermophile,
Thermoplasma acidophilum (TpCS), are compared with those of the citrate synthase
from a mesophile, pig heart (PCS). All discrete steps in the mechanistic sequence
of PCS can be identified in TpCS. The catalytic strategies identified in PCS,
destabilization of the oxaloacetate substrate carbonyl and stabilization of the
reactive species, acetyl-CoA enolate, are present in TpCS. Conformational
changes, which allow the enzyme to efficiently catalyze both condensation of
acetyl-CoA thioester and subsequently hydrolysis of citryl-CoA thioester within
the same active site, occur in both enzymes. However, significant differences
exist between the two enzymes. PCS is a characteristically efficient enzyme: no
internal step is clearly rate-limiting and the condensation step is readily
reversible. TpCS is a less efficient catalyst. Over a broad temperature range,
inadequate stabilization of the transition state for citryl-CoA hydrolysis
renders this step nearly rate-limiting for the forward reaction of TpCS. Further,
excessive stabilization of the citryl-CoA intermediate renders the condensation
step nearly irreversible. Values of substrate and solvent deuterium isotope
effects are consistent with the kinetic model. Near its temperature optimum (70
degrees C), there is a modest increase in the reversibility of the condensation
step for TpCS, but reversibility still falls short of that shown by PCS at 37
degrees C. The root cause of the catalytic inefficiency of TpCS may lie in the
lack of protein flexibility imposed by the requirement for thermal stability of
the protein itself or its temperature-labile substrate, oxaloacetate.
PMID- 10694396
TI - Selectivity of the yersiniabactin synthetase adenylation domain in the two-step
process of amino acid activation and transfer to a holo-carrier protein domain.
AB - The adenylation (A) domain of the Yersinia pestis nonribosomal peptide synthetase
that biosynthesizes the siderophore yersiniabactin (Ybt) activates three
molecules of L-cysteine and covalently aminoacylates the phosphopantetheinyl (P
pant) thiols on three peptidyl carrier protein (PCP) domains embedded in the two
synthetase subunits, two in cis (PCP1, PCP2) in subunit HMWP2 and one in trans
(PCP3) in subunit HMWP1. This two-step process of activation and loading by the A
domain is analogous to the operation of the aminoacyl-tRNA synthetases in
ribosomal peptide synthesis. Adenylation domain specificity for the first step of
reversible aminoacyl adenylate formation was assessed with the amino acid
dependent [(32)P]-PP(i)-ATP exchange assay to show that S-2-aminobutyrate and
beta-chloro-L-alanine were alternate substrates. The second step of A domain
catalysis, capture of the bound aminoacyl adenylate by the P-pant-SH of the PCP
domains, was assayed both by catalytic release of PP(i) and by covalent
aminoacylation of radiolabeled substrates on either the PCP1 fragment of HMWP2 or
the PCP3-thioesterase double domain fragment of HMWP1. There was little
selectivity for capture of each of the three adenylates by PCP3 in the second
step, arguing against any hydrolytic proofreading of incorrect substrates by the
A domain. The holo-PCP3 domain accelerated PP(i) release and catalytic turnover
by 100-200-fold over the leak rate (<1 min(-1)) of aminoacyl adenylates into
solution while PCP1 in trans had only about a 5-fold effect. Free pantetheine
could capture cysteinyl adenylate with a 25-50-fold increase in k(cat) while CoA
was 10-fold less effective. The K(m) of free pantetheine (30-50 mM) was 3 orders
of magnitude larger than that of PCP3-TE (10-25 microM), indicating a net 10(4)
greater catalytic efficiency for transfer to the P-pant arm of PCP3 by the Ybt
synthetase A domain, relative to P-pant alone.
PMID- 10694397
TI - A molecular coupling mechanism for the oxaloacetate decarboxylase Na+ pump as
inferred from mutational analysis.
AB - The oxaloacetate decarboxylase Na+ pump consists of subunits alpha, beta, and
gamma, and contains biotin as the prosthetic group. Membrane-bound subunit beta
catalyzes the decarboxylation of carboxybiotin coupled to Na+ translocation, and
consumes a periplasmically derived proton. Site-directed mutagenesis of conserved
amino acids of transmembrane helix VIII indicated that residues N373, G377, S382,
and R389 are functionally important. The polar side groups of these amino acids
may constitute together with D203 a network of ionizable groups which promotes
the translocation of Na+ and the oppositely oriented H+ across the membrane.
Evidence is presented that two Na+ ions are bound simultaneously to subunit beta
during transport with D203 and S382 acting as binding sites. Sodium ion binding
from the cytoplasm to both sites elicits decarboxylation of carboxybiotin, and a
conformational switch exposes the bound Na+ ions toward the periplasm. After
dissociation of Na+ and binding of H+, the cytoplasmically exposed conformation
is regained.
PMID- 10694398
TI - Spectroscopic analysis of the trinuclear cluster in the Fet3 protein from yeast,
a multinuclear copper oxidase.
AB - The Fet3 protein (Fet3p) is a multinuclear copper oxidase essential for high
affinity iron uptake in yeast. Fet3p contains one type 1, one type 2, and a
strongly antiferromagnetically coupled binuclear Cu(II)-Cu(II) type 3 copper. The
type 2 and type 3 sites constitute a structurally distinct trinuclear cluster at
which dioxygen is reduced to water. In Fet3p, as in ceruloplasmin, Fe(II) is
oxidized to Fe(III) at the type 1 copper; this is the ferroxidase reaction that
is fundamental to the physiologic function of these two enzymes. Using site
directed mutagenesis, we have generated type 1-depleted (T1D), type 2-depleted
(T2D), and T1D/T2D mutants. None were active in the essential ferroxidase
reaction catalyzed by Fet3p. However, the spectroscopic signatures of the
remaining Cu(II) sites in any one of the three mutants were indistinguishable
from those exhibited by the wild type. Although the native protein and the T1D
mutant were isolated in the completely oxidized Cu(II) form, the T2D and T1D/T2D
mutants were found to be completely reduced. This result is consistent with the
essential role of the type 2 copper in dioxygen turnover, and with the
suggestions that cuprous ion is the valence state of intracellular copper.
Although stable to dioxygen, the Cu(I) sites in both proteins were readily
oxidized by hydrogen peroxide. The double mutant was extensively analyzed by X
ray absorption spectroscopy. Edge and near-edge features clearly distinguished
the oxidized from the reduced form of the binuclear cluster. EXAFS was strongly
consistent with the expected coordination of each type 3 copper by three
histidine imidazoles. Also, copper scattering was observed in the oxidized
cluster along with scattering from a ligand corresponding to a bridging oxygen.
The data derived from the reduced cluster indicated that the bridge was absent in
this redox state. In the reduced form of the double mutant, an N/O ligand was
apparent that was not seen in the reduced form of the T1D protein. This ligand in
T1D/T2D could be either the remaining type 2 copper imidazole ligand (from
His416) or a water molecule that could be stabilized at the type 3 cluster by H
bonding to this side chain. If present in the native protein, this H(2)O could
provide acid catalysis of dioxygen reduction at the reduced trinuclear center.
PMID- 10694399
TI - Evidence for the rate of the final step in the bacteriorhodopsin photocycle being
controlled by the proton release group: R134H mutant.
AB - Light absorbed by bacteriorhodopsin (bR) leads to a proton being released at the
extracellular surface of the purple membrane. Structural studies as well as
studies of mutants of bR indicate that several groups form a pathway for proton
transfer from the Schiff base to the extracellular surface. These groups include
D85, R82, E204, E194, and water molecules. Other residues may be important in
tuning the initial state pK(a) values of these groups and in mediating light
induced changes of the pK(a) values. A potentially important residue is R134: it
is located close to E194 and might interact electrostatically to affect the pK(a)
of E194 and light-induced proton release. In this study we investigated effects
of the substitution of R134 with a histidine on light-induced proton release and
on the photocycle transitions associated with proton transfer. By measuring the
light-induced absorption changes versus pH, we found that the R134H mutation
results in an increase in the pK(a) of the proton release group in both the M
(0.6 pK unit) and O (0.7 pK unit) intermediate states. This indicates the
importance of R134 in tuning the pK(a) of the group that, at neutral and high pH,
releases the proton upon M formation (fast proton release) and that, at low pH,
releases the proton simultaneously with O decay (slow proton release). The higher
pK(a) of the proton release group found in R134H correlates with the slowing of
the rate of the O --> bR transition at low pH and probably is the cause of this
slowing. The pH dependence of the fraction of the O intermediate is altered in
R134H compared to the WT but is similar to that in the E194D mutant: a very small
amount of O is present at neutral pH, but the fraction of O increases greatly
upon decreasing the pH. These results provide further support for the hypothesis
that the O --> bR transition is controlled by the rate of deprotonation of the
proton release group. These data also provide further evidence for the importance
of the R134-E194 interaction in modulating proton release from D85 after light
has led to its being protonated.
PMID- 10694400
TI - Formation and reactions of the heme-dioxygen intermediate in the first and second
steps of nitric oxide synthesis as studied by stopped-flow spectroscopy under
single-turnover conditions.
AB - To better understand the mechanism of nitric oxide (NO) synthesis, we studied
conversion of N-hydroxy-L-arginine (NOHA) or L-arginine (Arg) to citrulline and
NO under single-turnover conditions using the oxygenase domain of neuronal nitric
oxide synthase (nNOSoxy) and rapid scanning stopped-flow spectroscopy. When
anaerobic nNOSoxy saturated with H(4)B and NOHA was provided with 0.5 or 1
electron per heme and then exposed to air at 25 degrees C, it formed 0.5 or 1 mol
of citrulline/mol of heme, respectively, indicating that NOHA conversion had 1:1
stoichiometry with respect to electrons added. Identical experiments with Arg
produced substoichiometric amounts of NOHA or citrulline even when up to 3
electrons were provided per heme. Transient spectral intermediates were
investigated at 10 degrees C. For NOHA, four species were observed in the
following sequence: starting ferrous nNOSoxy, a transient ferrous-dioxygen
complex, a transient ferric-NO complex, and ferric nNOSoxy. For Arg, transient
intermediates other than the ferrous-dioxygen species were not apparent during
the reaction. Our results provide a kinetic framework for formation and reactions
of the ferrous-dioxygen complex in each step of NO synthesis and establish that
(1) the ferrous-dioxy enzyme reacts quantitatively with NOHA but not with Arg and
(2) its reaction with NOHA forms 1 NO/heme, which immediately binds to form a
ferric heme-NO complex.
PMID- 10694401
TI - Demonstration of a conserved histidine and two water ligands at the Mn2+ site in
Diocleinae lectins by pulsed EPR spectroscopy.
AB - Lectins from the Diocleinae subtribe, including Canavalia brasiliensis, Canavalia
bonariensis, Canavalia grandiflora, Cratylia floribunda, Dioclea grandiflora,
Dioclea guianensis, Dioclea rostrata, Dioclea violacea, and Dioclea virgata, have
been recently isolated and characterized in terms of their carbohydrate binding
specificities. Although all of the lectins are Man/Glc specific, they possess
different biological activities. In the present study, electron paramagnetic
resonance (EPR) spectroscopy demonstrates that all nine Diocleinae lectins
contain Mn2+. The spectra of C. floribunda and D. rostrata suggest Mn2+ site
symmetry different from that of the other seven lectins. However, electron spin
echo envelope modulation (ESEEM) spectroscopy indicates that all nine lectins are
coordinated to a histidyl imidazole, with similar electron-nuclear coupling to
the Mn2+-bound imidazole nitrogen. ESEEM also demonstrates ligation of two water
molecules to Mn2+ in all nine Diocleinae lectins. Thus, the EPR and ESEEM data
indicate the presence of a Mn2+ binding site in the above Diocleinae lectins with
a conserved histidine residue and two water ligands.
PMID- 10694403
TI - Nonlinear electron paramagnetic resonance studies of the interaction of
cytochrome c oxidase with spin-labeled lipids in gel-phase membranes.
AB - The interaction of lipids, spin-labeled at different positions in the sn-2 chain,
with cytochrome c oxidase reconstituted in gel-phase membranes of
dimyristoylphosphatidylglycerol has been studied by electron paramagnetic
resonance (EPR) spectroscopy. Nonlinear EPR methods, both saturation transfer EPR
and progressive saturation EPR, were used. Interaction with the protein largely
removes the flexibility gradient of the lipid chains in gel-phase membranes. The
rotational mobility of the chain segments is reduced, relative to that for gel
phase lipids, by the intramembranous interaction with cytochrome c oxidase. This
holds for all positions of chain labeling, but the relative effect is greater for
chain segments closer to the terminal methyl ends. Modification of the
paramagnetic metal-ion centers in the protein by binding azide has a pronounced
effect on the spin-lattice relaxation of the lipid spin labels. This demonstrates
that the centers modified are sufficiently close to the first-shell lipids to
give appreciable dipolar interactions and that their vertical location in the
membrane is closer to the 5-position than to the 14-position of the lipid chains.
PMID- 10694402
TI - Metal requirements of a diadenosine pyrophosphatase from Bartonella
bacilliformis: magnetic resonance and kinetic studies of the role of Mn2+.
AB - Recombinant IalA protein from Bartonella bacilliformis is a monomeric adenosine
5'-tetraphospho-5'-adenosine (Ap4A) pyrophosphatase of 170 amino acids that
catalyzes the hydrolysis of Ap4A, Ap5A, and Ap6A by attack at the delta
phosphorus, with the departure of ATP as the leaving group [Cartwright et al.
(1999) Biochem. Biophys. Res. Commun. 256, 474-479]. When various divalent
cations were tested over a 300-fold concentration range, Mg2+, Mn2+, and Zn2+
ions were found to activate the enzyme, while Ca2+ did not. Sigmoidal activation
curves were observed with Mn2+ and Mg2+ with Hill coefficients of 3.0 and 1.6 and
K0.5 values of 0.9 and 5.3 mM, respectively. The substrate M2+ x Ap4A showed
hyperbolic kinetics with Km values of 0.34 mM for both Mn2+ x Ap4A and Mg2+ x
Ap4A. Direct Mn2+ binding studies by electron paramagnetic resonance (EPR) and by
the enhancement of the longitudinal relaxation rate of water protons revealed two
Mn2+ binding sites per molecule of Ap4A pyrophosphatase with dissociation
constants of 1.1 mM, comparable to the kinetically determined K0.5 value of Mn2+.
The enhancement factor of the longitudinal relaxation rate of water protons due
to bound Mn2+ (epsilon b) decreased with increasing site occupancy from a value
of 12.9 with one site occupied to 3.3 when both are occupied, indicating site
site interaction between the two enzyme-bound Mn2+ ions. Assuming the decrease in
epsilon(b) to result from cross-relaxation between the two bound Mn2+ ions yields
an estimated distance of 5.9 +/- 0.4 A between them. The substrate Ap4A binds one
Mn2+ (Kd = 0.43 mM) with an epsilon b value of 2.6, consistent with the molecular
weight of the Mn2+ x Ap4A complex. Mg2+ binding studies, in competition with
Mn2+, reveal two Mg2+ binding sites on the enzyme with Kd values of 8.6 mM and
one Mg2+ binding site on Ap4A with a Kd of 3.9 mM, values that are comparable to
the K0.5 for Mg2+. Hence, with both Mn2+ and Mg2+, a total of three metal binding
sites were found-two on the enzyme and one on the substrate-with dissociation
constants comparable to the kinetically determined K0.5 values, suggesting a role
in catalysis for three bound divalent cations. Ca2+ does not activate Ap4A
pyrophosphatase but inhibits the Mn2+-activated enzyme competitively with a Ki =
1.9 +/- 1.3 mM. Ca2+ binding studies, in competition with Mn2+, revealed two
sites on the enzyme with dissociation constants (4.3 +/- 1.3 mM) and one on Ap4A
with a dissociation constant of 2.1 mM. These values are similar to its Ki
suggesting that inhibition by Ca2+ results from the complete displacement of Mn2+
from the active site. Unlike the homologous MutT pyrophosphohydrolase, which
requires only one enzyme-bound divalent cation in an E x M2+ x NTP x M2+ complex
for catalytic activity, Ap4A pyrophosphatase requires two enzyme-bound divalent
cations that function in an active E x (M2+)2 x Ap4A x M2+ complex.
PMID- 10694404
TI - Unfolding thermodynamics of the tetrameric chaperone, SecB.
AB - SecB is a cytosolic tetrameric chaperone in Escherichia coli, which maintains
polypeptides, destined for export in a translocation competent state. The
thermodynamics of unfolding of SecB was studied as a function of protein
concentration, by using high sensitivity-differential scanning calorimetry and
spectroscopic methods. The thermal unfolding of tetrameric SecB is reversible and
can be well described as a two-state transition in which the folded tetramer is
converted directly to unfolded monomers. Increasing the pH decreases the
stability of the tetramer significantly, the T(m) changing from 341.3 K at pH 6.5
to 332.6 K at pH 9.5. The value of DeltaC(p) obtained from measurements of
DeltaH(m) as a function of T(m) was 10.7 +/- 0.7 kcal mol(-1) K(-1). The value of
DeltaC(p) is among the highest measured for a multimeric protein. At 298 K, pH
7.4, the DeltaG degrees (u) for the SecB tetramer is 27.9 +/- 2 kcal mol(-1).
Denaturant-mediated unfolding of SecB was found to be irreversible. The
reactivity of the four solvent-exposed free thiols in tetrameric SecB is salt
dependent. The kinetics of reactivity suggests that these four cysteines are in
close proximity to each other and that these residues on each monomer are in
chemically identical environments. The thermodynamic data suggest that SecB is a
stable, well-folded, and tightly packed tetramer and that substrate binding
occurs at a surface site rather than at an interior cavity.
PMID- 10694405
TI - Predimerization of recombinant platelet-derived growth factor receptor
extracellular domains increases antagonistic potency.
AB - Platelet-derived growth factor (PDGF) is a dimeric growth factor acting through
tyrosine kinase alpha- and beta-receptors. In both receptors, the extracellular
parts are composed of five Ig-like domains. Functional mapping of the
extracellular part of the receptors have shown that ligand-binding occurs to Ig
like domains 2 and 3 and that Ig-like domain 4 is involved in receptor-receptor
interactions. Recombinant GST-fusion proteins of PDGF alpha-receptor Ig-like
domains 1-4 and beta-receptor Ig-like domains 1-3 (alphaRD1-4-GST and betaRD1-3
GST) were generated and compared with their cleaved counterparts (alphaRD1-4 and
betaRD1-3) with regard to their ability to block PDGF binding to cell surface
receptors. In the case of both the alpha- and the beta-receptors, 100-1000-fold
lower concentrations of the GST-fusion proteins were required, as compared to the
cleaved forms, for inhibition of PDGF binding to cell surface receptors. alphaRD1
4-GST and betaRD1-3-GST, in contrast to alphaRD1-4 and betaRD1-3, were shown to
occur as ligand independent dimers. Covalently cross-linked alphaRD1-4 dimers
displayed a 50-fold increased potency as compared to alphaRD1-4. We thus conclude
that the dimeric nature of alphaRD1-4-GST and betaRD1-3-GST is responsible for
the high antagonistic potency of the fusion proteins.
PMID- 10694406
TI - Formation of novel D-ring and E-ring isoprostane-like compounds (D4/E4
neuroprostanes) in vivo from docosahexaenoic acid.
AB - Free radical-mediated oxidant injury and lipid peroxidation have been implicated
in a number of neural disorders. We have reported that bioactive prostaglandin
D2/E2-like compounds, termed D2/E2-isoprostanes, are produced in vivo by the free
radical-catalyzed peroxidation of arachidonic acid. Docosahexaenoic acid, in
contrast to arachidonic acid, is the most abundant unsaturated fatty acid in
brain. We therefore questioned whether D/E-isoprostane-like compounds (D4/E4
neuroprostanes) are formed from the oxidation of docosahexaenoic acid. Levels of
putative D4/E4-neuroprostanes increased 380-fold after oxidation of
docosahexaenoic acid in vitro from 15.2 +/- 6.3 to 5773 +/- 1024 ng/mg of
docosahexaenoic acid. Subsequently, chemical approaches and liquid chromatography
electrospray ionization tandem mass spectrometry definitively identified these
compounds as D4/E4-neuroprostanes. We then explored the formation of D4/E4
neuroprostanes from a biological source, rat brain synaptosomes. Basal levels of
D4/E4-neuroprostanes were 3.8 +/- 0.6 ng/mg of protein and increased 54-fold
after oxidation (n = 4). We also detected these compounds in fresh brain tissue
from rats at levels of 12.1 +/- 2.4 ng/g of brain tissue (n = 3) and in human
brain tissue at levels of 9.2 +/- 4.1 ng/g of brain tissue (n = 4). Thus, these
studies have identified novel D/E-ring isoprostane-like compounds that are
derived from docosahexaenoic acid and that are formed in brain in vivo. The fact
that they are readily detectable suggests that ongoing oxidative stress is
present in the central nervous system of humans and animals. Further,
identification of these compounds provides a rationale for examining their role
in neurological disorders associated with oxidant stress.
PMID- 10694407
TI - Design of P1' and P3' residues of trivalent thrombin inhibitors and their crystal
structures.
AB - Synthetic bivalent thrombin inhibitors comprise an active site blocking segment,
a fibrinogen recognition exosite blocking segment, and a linker connecting these
segments. Possible nonpolar interactions of the P1' and P3' residues of the
linker with thrombin S1' and S3' subsites, respectively, were identified using
the "Methyl Scan" method [Slon-Usakiewicz et al. (1997) Biochemistry 36, 13494
13502]. A series of inhibitors (4-tert-butylbenzenesulfonyl)-Arg-(D-pipecolic
acid)-Xaa-Gly-Yaa-Gly-betaAla-Asp-Tyr-Glu-Pro-Ile-Pro-Glu-Glu-Ala- (be ta
cyclohexylalanine)-(D-Glu)-OH, in which nonpolar P1' residue Xaa or P3' residue
Yaa was incorporated, were designed and improved the affinity to thrombin.
Substitution of the P3' residue with D-phenylglycine or D-Phe improved the K(i)
value to (9.5 +/- 0.6) x 10(-14) or 1.3 +/- 0.5 x 10(-13) M, respectively,
compared to that of a reference inhibitor with Gly residues at Xaa and Yaa
residues (K(i) = (2.4 +/- 0.5) x 10(-11) M). Similarly, substitution of the P1'
residue with L-norleucine or L-beta-(2-thienyl)alanine lowered the K(i) values to
(8.2 +/- 0.6) x 10(-14) or (5.1 +/- 0.4) x 10(-14) M, respectively. The linker
Gly-Gly-Gly-betaAla of the inhibitors in the previous sentence was simplified
with 12-aminododecanoic acid, resulting in further improvement of the K(i) values
to (3.8 +/- 0.6) x 10(-14) or (1.7 +/- 0.4) x 10(-14) M, respectively. These K(i)
values are equivalent to that of natural hirudin (2.2 x 10(-14) M), yet the size
of the synthetic inhibitors (2 kD) is only one-third that of hirudin (7 kD). Two
inhibitors, with L-norleucine or L-beta-(2-thienyl)alanine at the P1' residue and
the improved linker of 12-aminododecanoic acid, were crystallized in complex with
human alpha-thrombin. The crystal structures of these complexes were solved and
refined to 2.1 A resolution. The Lys(60F) side chain of thrombin moved
significantly and formed a large nonpolar S1' subsite to accommodate the bulky
P1' residue.
PMID- 10694408
TI - Hormone-sensitive lipase functions as an oligomer.
AB - Hormone-sensitive lipase (HSL) is a cytosolic neutral lipase whose activity is
regulated by reversible phosphorylation and which is thought to be the rate
limiting enzyme for the mobilization of FFA from adipose tissue. In the current
studies the subunit structure of HSL has been explored using sucrose gradient
centrifugation and in vivo and in vitro protein-protein interactions. Evidence is
provided to demonstrate that HSL exists as a functional dimer composed of
homologous subunits. Dimeric HSL displayed approximately 40-fold greater activity
against cholesteryl ester substrate when compared with monomeric HSL without any
differences in affinity for the substrate. Truncations of HSL identified the
importance of the N-terminal 300 amino acids, as well as other regions, in
participating in the oligomerization of HSL. These studies support the notion
that the N-terminal region of HSL represents a docking domain for protein-protein
interactions and provide an additional mechanism for the posttranslational
control of HSL activity in the cell via oligomerization.
PMID- 10694409
TI - Probing the mechanistic role of glutamate residue in the zinc-binding motif of
type A botulinum neurotoxin light chain.
AB - Type A botulinum neurotoxin (BoNT/A) is a zinc endopeptidase that contains the
consensus sequence HEXXH (residues 223-227) in the toxic light chain (LC). The X
ray structure of the toxin has predicted that the two histidines of this motif
are two of the three zinc-coordinating ligands and that the glutamate is a
crucial amino acid involved in catalysis. The functional implication of E224 in
the motif of LC was investigated by replacing the residue with glutamine and
aspartate using site-directed mutagenesis. Substitution of Glu-224 with Gln
(E224Q) resulted in a total loss of the endopeptidase activity, whereas
substitution with Asp (E224D) retained about 1.4% of the enzymatic activity
(k(cat) 140 vs 1.9 min(-1), respectively). However, K(m) values for wild-type and
E224D BoNT/A LC were similar, 42 and 50 microM, respectively. Global structure,
in terms of secondary structure content and topography of aromatic amino
residues, Zn(2+) content, and substrate binding ability are retained in the
enzymatically inactive mutants. Titration of Zn(2+) to EDTA-treated wild-type and
mutant proteins indicated identical enthalpy for Zn(2+) binding. These results
suggest an essential and direct role of the carboxyl group of Glu-224 in the
hydrolysis of the substrate. The location of the carboxyl group at a precise
position is critical for the enzymatic activity, as replacement of Glu-224 with
Asp resulted in almost total loss of the activity.
PMID- 10694410
TI - Effect of pressure on deuterium isotope effects of yeast alcohol dehydrogenase:
evidence for mechanical models of catalysis.
AB - Moderate pressure accelerates hydride transfer catalyzed by yeast alcohol
dehydrogenase, indicative of a large negative volume of activation [Cho and
Northrop (1999) Biochemistry 38, 7470-7475]. A comparison of the effects of
pressure on the oxidation of normal versus dideuteriobenzyl alcohol generates a
monophasic decrease in the intrinsic isotope effect; therefore, the volume of
activation for the transition-state of deuteride transfer must be even more
negative, by 10.4 mL/mol. This finding appears consistent with hydrogen tunneling
previously proposed for this dehydrogenase [Cha, Y., Murray, C. J., and Klinman,
J. P. (1989) Science 243, 1325-1330]. However, a global fit of the primary data
shows that the entire isotope effect arises from a transition-state phenomenon,
unlike normal isotope effects, which arise from different vibrational frequencies
in reactant states, and tunneling isotope effects, which arise from a mixture of
both states. Assuming the phenomenon is tunneling, the isotopic data are
consistent with a Bell tunneling correction factor of Q(H) = 12 and an imaginary
frequency of nu(H) = 1220 cm(-1), the first so calculated from experimental
enzymatic data. This excessively large correction factor and the large difference
in the isotopic activation volumes, plus the low isotope effects at extrapolated
pressures, challenge traditional applications of physical organic chemistry and
transition-state theory to enzymatic catalysis. They suggest instead that
something other than transition-state stabilization or tunneling is responsible
for the rate acceleration, something unique to the enzymatic transition state
that does not occur in nonenzymatic reactions. Arguments for the vibrational
model of coupled atomic motions and the fluctuating enzyme model of protein
domain motion are put forward as possible interpretations.
PMID- 10694411
TI - Naturally occurring alkylresorcinols that mediate DNA damage and inhibit its
repair.
AB - A study of di- and trihydroxyalkylbenzenes and bis(dihydroxyalkylbenzenes)
revealed that several compounds were capable of both mediating Cu(2+)-dependent
DNA cleavage and strongly inhibiting DNA polymerase beta. The most potent DNA
polymerase beta inhibitors were bis(dihydroxyalkylbenzenes) 5 and 6; compounds 3
and 4 were also reasonably potent. The length of the alkyl substituent was found
to be a critical element for DNA polymerase beta inhibition, since compounds 1
and 2 had shorter substituents than 3 and were completely inactive. Lineweaver
Burk plots revealed that 3, 4, and 6 exhibited mixed inhibition of DNA polymerase
beta with respect to both activated DNA and dTTP. Unsaturated
bis(dihydroxyalkylbenzene) 5 was a pure noncompetitive inhibitor with respect to
both substrates and associated avidly with the enzyme whether or not it was in
complex with its substrate(s). Copper(II)-mediated DNA cleavage was the most
pronounced for the trihydroxyalkylbenzene 3, consistent with an earlier report
[Singh, U. S., Scannell, R. T., An, H., Carter, B. J., and Hecht, S. M. (1995) J.
Am. Chem. Soc. 117, 12691-12699]. Unsaturated bis(dihydroxyalkylbenzene) 5 was
the next most active DNA cleaving agent, followed by the dihydroxyalkylbenzene 4.
The saturated bis(dihydroxyalkylbenzene) (6) did not cleave DNA well in a cell
free system under the conditions studied but nonetheless potentiated the effects
of bleomycin to the greatest extent in cell culture studies. Interestingly,
compound 5 produced a reduction in the numbers of viable cells when incubated in
the presence of bleomycin and a further reduction in the numbers of viable cells
in the presence of both bleomycin and Cu(2+). The same effect was noted to a
lesser extent for compound 3 but not for 4 or 6.
PMID- 10694412
TI - Thermodynamics of substrate binding to the chaperone SecB.
AB - The thermodynamics of binding of unfolded polypeptides to the chaperone SecB was
investigated in vitro by isothermal titration calorimetry and fluorescence
spectroscopy. The substrates were reduced and carboxamidomethylated forms of
RNase A, BPTI, and alpha-lactalbumin. SecB binds both fully unfolded RNase A and
BPTI as well as compact, partially folded disulfide intermediates of alpha
lactalbumin, which have 40-60% of native secondary structure. The heat capacity
changes observed on binding the reduced and carboxamidomethylated forms of alpha
lactalbumin, BPTI, and RNase A were found to be -0.10, -0.29, and -0.41 kcal mol(
1) K(-1), respectively, and suggest that between 7 and 29 residues are buried
upon substrate binding to SecB. In all cases, binding occurs with a stoichiometry
of one polypeptide chain per monomer of SecB. There is no evidence for two
separate types of binding sites for positively charged and hydrophobic ligands.
Spectroscopic and proteolysis protection studies of the binding of SecB to poly-L
Lys show that binding of highly positively charged peptide ligands to negatively
charged SecB leads to charge neutralization and subsequent aggregation of SecB.
The data are consistent with a model where SecB binds substrate molecules at an
exposed hydrophobic cleft. SecB aggregation in the absence of substrate is
prevented by electrostatic repulsion between negatively charged SecB tetramers.
PMID- 10694413
TI - Refined X-ray structures of the oxidized, at 1.3 A, and reduced, at 1.17 A,
PMID- 10694414
TI - Inhibition of the establishment of zygotic polarity by protein tyrosine kinase
inhibitors leads to an alteration of embryo pattern in Fucus.
AB - Fucoid algae, including the genus Fucus and Pelvetia, are recognized as model
systems to study early embryogenesis in plants. In particular the zygotes of
these fucoid algae are highly suitable experimental systems for investigating the
establishment of polarity and its requirement for later embryogenesis. However,
the transduction pathways involved in the initiation of polarization are still
poorly understood, and the link between the early polarization processes and
embryo long-term patterning has never been experimentally demonstrated. We,
therefore, have investigated the putative role of protein phosphorylation in the
regulation of early embryogenesis, using a combined pharmacological and
biochemical approach. Among the various protein kinase inhibitors tested, a
subset of well-known PTK inhibitors, including genistein, prevented germination
but had no effect on growth of germinated zygotes and embryos. Inhibition of
germination appeared to be a direct consequence of prevention of polarization
since genistein and other PTK inhibitors specifically inhibited axis formation in
a light-independent manner. Genistein inhibited cellular events associated with
polarization such as polarized secretion of cell wall sulfated compounds.
Anchorage of F-actin at the rhizoid pole was also inhibited and F-actin
redistributed in response to a new light vector. Zygotes inhibited in the
polarization process over the period of axis formation recovered from the
treatment and displayed differentiated cellular structures after a few days.
However, they exhibited a deeply disorganized pattern, suggesting that the early
polarization process is essential for normal patterning of the embryo. Western
blot analysis of protein phosphorylation showed that the patterns of protein
phosphorylation changed during development and were disturbed by treatments with
genistein. This drug also inhibited in vitro autophosphorylation. The nature of
the genistein-sensitive kinases required for polarization and long-term
patterning is discussed in light of these data.
PMID- 10694415
TI - The hindsight gene is required for epithelial maintenance and differentiation of
the tracheal system in Drosophila.
AB - During animal development, morphogenesis of tissues and organs requires dynamic
cell shape changes and movements that are accomplished without loss of epithelial
integrity. Data from vertebrate and invertebrate systems have implicated several
cell surface and cytoskeleton-associated molecules in the establishment and
maintenance of epithelial architecture, but there has been little analysis of the
genetic regulatory hierarchies that control epithelial morphogenesis in specific
tissues. Here we show that the Drosophila Hindsight nuclear zinc-finger protein
is required during tracheal morphogenesis for the maintenance of epithelial
integrity and assembly of apical extracellular structures known as taenidia. In
hindsight (hnt) mutants tracheal placodes form, invaginate, and undergo primary
branching as well as early fusion events. Starting at midembryogenesis, however,
the tracheal epithelium collapses or expands to give rise to sacs of tissue.
While a subset of hnt mutant tracheal cells enters the apoptotic pathway, genetic
suppression of apoptosis indicates that this is not the cause of the epithelial
defects. Surviving hnt mutant tracheal cells retain cell-cell junctions and a
normal subcellular distribution of apical markers such as Crumbs and DE-Cadherin.
However, taenidia do not form on the lumenal surface of tracheal cells. While
loss of epithelial integrity is a common feature of crumbs, stardust, and hnt
mutants, defective assembly of taenidia is unique to hnt mutants. These data
suggest that HNT is a tissue-specific factor that regulates maintenance of the
tracheal epithelium as well as differentiation of taenidia.
PMID- 10694416
TI - Autocrine expression and ontogenetic functions of the PACAP ligand/receptor
system during sympathetic development.
AB - The superior cervical ganglion (SCG) is a well-characterized model of neural
development, in which several regulatory signals have been identified. Vasoactive
intestinal peptide (VIP) has been found to regulate diverse ontogenetic processes
in sympathetics, though functional requirements for high peptide concentrations
suggest that other ligands are involved. We now describe expression and functions
of pituitary adenylate cyclase-activating polypeptide (PACAP) during SCG
ontogeny, suggesting that the peptide plays critical roles in neurogenesis. PACAP
and PACAP receptor (PAC(1)) mRNA's were detected at embryonic days 14.5 (E14.5)
through E17.5 in vivo and virtually all precursors exhibited ligand and receptor,
indicating that the system is expressed as neuroblasts proliferate. Exposure of
cultured precursors to PACAP peptides, containing 27 or 38 residues, increased
mitogenic activity 4-fold. Significantly, PACAP was 1000-fold more potent than
VIP and a highly potent and selective antagonist entirely blocked effects of
micromolar VIP, consistent with both peptides acting via PAC(1) receptors.
Moreover, PACAP potently enhanced precursor survival more than 2-fold, suggesting
that previously defined VIP effects were mediated via PAC(1) receptors and that
PACAP is the more significant developmental signal. In addition to neurogenesis,
PACAP promoted neuronal differentiation, increasing neurite outgrowth 4-fold and
enhancing expression of neurotrophin receptors trkC and trkA. Since PACAP
potently activated cAMP and PI pathways and increased intracellular Ca(2+), the
peptide may interact with other developmental signals. PACAP stimulation of
precursor mitosis, survival, and trk receptor expression suggests that the
signaling system plays a critical autocrine role during sympathetic neurogenesis.
PMID- 10694417
TI - Analyses of segment-specific expression of alkaline phosphatase activity in the
mesoderm of the oligochaete annelid Tubifex: implications for specification of
segmental identity.
AB - In the embryos of the oligochaete annelid Tubifex, segments VII and VIII
specifically express mesodermal alkaline phophatase (ALP) activity in the
ventrolateral region. In this study, we examined whether this segment-specific
expression of ALP activity depends on external cues. Cell lineage analyses show
that the ALP-expressing cells originate from M teloblasts. Furthermore, a set of
teloblast-ablation experiments demonstrated that the seventh and eighth primary m
blast cells (m7 and m8) produced from M teloblasts give rise to ALP-expressing
cells in segments VII and VIII, respectively, and that primary m blast cells
other than m7 and m8 lack the ability to generate ALP-expressing progeny cells.
The results of another set of blastomere-ablation experiments suggest that ALP
expressing cells emerge independently of interactions with surrounding tissues.
Teloblast-transplantation experiments demonstrated that m8 can generate ALP
expressing cells in an ectopical position, suggesting that it is unlikely that
ALP activity emerges in response to the positional cues residing in the embryo.
These results suggest that m7 and m8 are exclusively specified as precursors of
ALP-expressing cells at the time of their birth from M teloblasts. We propose
that segmental identities in primary m blast cells of the Tubifex embryo are
determined according to the genealogical position in the M lineage and that the M
teloblast possesses a developmental program through which the sequence of blast
cell identities is determined.
PMID- 10694418
TI - Influence of FGF4 on digit morphogenesis during limb development in the mouse.
AB - Much of what we currently know about digit morphogenesis during limb development
is deduced from embryonic studies in the chick. In this study, we used ex utero
surgical procedures to study digit morphogenesis during mouse embryogenesis. Our
studies reveal some similarities; however, we have found considerable differences
in how the chick and the mouse autopods respond to experimentation. First, we are
not able to induce ectopic digit formation from interdigital cells as a result of
wounding or TGFbeta-1 application in the mouse, in contrast to what is observed
in the chick. Second, FGF4, which inhibits the formation of ectopic digits in the
chick, induces a digit bifurcation response in the mouse. We demonstrate with
cell marking studies that this bifurcation response results from a reorganization
of the prechondrogenic tip of the digit rudiment. The FGF4 effect on digit
morphogenesis correlates with changes in the expression of a number of genes,
including Msx1, Igf2, and the posterior members of the HoxD cluster. In addition,
the bifurcation response is digit-specific, being restricted to digit IV. We
propose that FGF4 is an endogenous signal essential for skeletal branching
morphogenesis in the mouse. This work stresses the existence of major differences
between the chick and the mouse in how digit morphogenesis is regulated and is
thus consistent with the view that vertebrate digit evolution is a relatively
recent event. Finally, we discuss the relationship between the digit IV
bifurcation restriction and the placement of the metapterygial axis in the
evolution of the tetrapod limb.
PMID- 10694419
TI - BMPs are required at two steps of limb chondrogenesis: formation of
prechondrogenic condensations and their differentiation into chondrocytes.
AB - Formation of the long bones requires a cartilage template. Cartilage formation
(chondrogenesis) proceeds through determination of cells and their aggregation
into prechondrogenic condensations, differentiation into chondrocytes, and later
maturation. Several studies indicate that members of the bone morphogenetic
protein (BMP) family promote cartilage formation, but the exact step(s) in which
BMPs are involved during this process remains undefined. To resolve this issue,
we have used a retroviral vector to misexpress the BMP antagonist Noggin in the
embryonic chick limb. Unlike previous reports, we have characterized the
resulting phenotype in depth, analyzing histological and early chondrogenic
markers, as well as the patterns of cell death and proliferation. Misexpression
of Noggin prior to the onset of chondrogenesis leads to the total absence of
skeletal elements, as previously reported (J. Capdevila and R. L. Johnson, 1998,
Dev. Biol. 197, 205-217). Noggin inhibits cartilage formation at two distinct
steps. First, we demonstrate that mesenchymal cells do not aggregate into
prechondrogenic condensations, and additional results suggest that these cells
persist in an undifferentiated state. Second, we show that differentiation of
chondroprogenitors into chondrocytes can also be blocked, concurrent with
expanded expression of a presumptive joint region marker. In addition, we
observed alterations in muscle and tendon morphogenesis, and the potential role
of BMPs in these processes will be discussed. Our studies therefore provide in
vivo evidence that BMPs are necessary for different steps of chondrogenesis:
chondroprogenitor determination and/or condensation and subsequent
differentiation into chondrocytes.
PMID- 10694420
TI - Reduced Pax2 gene dosage increases apoptosis and slows the progression of renal
cystic disease.
AB - The murine cpk mouse develops a rapid-onset polycystic kidney disease (PKD) with
many similarities to human PKD. During kidney development, the transcription
factor Pax2 is required for the specification and differentiation of the renal
epithelium. In humans, Pax2 is also expressed in juvenile cystic kidneys where it
correlates with cell proliferation. In this report, Pax2 expression is
demonstrated in the cystic epithelium of the mouse cpk kidneys. To assess the
role of Pax2 during the development of polycystic kidney disease, the progression
of renal cysts was examined in cpk mutants carrying one or two alleles of Pax2.
Reduced Pax2 gene dosage resulted in a significant inhibition of renal cyst
growth while maintaining more normal renal structures. The inhibition of cyst
growth was not due to reduced proliferation of the cystic epithelium, rather to
increased cell death in the Pax2 heterozygotes. Increased apoptosis with reduced
Pax2 gene dosage was also observed in normal developing kidneys. Thus, increased
cell death is an integral part of the Pax2 heterozygous phenotype and may be the
underlying cause of Pax gene haploinsufficiency. That the cystic epithelium
requires Pax2 for continued expansion underscores the embryonic nature of the
renal cystic cells and may provide new insights toward growth suppression
strategies.
PMID- 10694421
TI - Protein kinase expression during murine mammary development.
AB - The susceptibility of the mammary gland to carcinogenesis is influenced by its
normal development, particularly during developmental stages such as puberty and
pregnancy that are characterized by marked changes in proliferation and
differentiation. Protein kinases are important regulators of proliferation and
differentiation, as well as of neoplastic transformation, in a wide array of
tissues, including the breast. Using a RT-PCR-based cloning strategy, we have
identified 41 protein kinases that are expressed in breast cancer cell lines and
in the murine mammary gland during development. The expression of each of these
kinases was analyzed throughout postnatal mammary gland development as well as in
a panel of mammary epithelial cell lines derived from distinct transgenic models
of breast cancer. Although the majority of protein kinases isolated in this
screen have no currently recognized role in mammary development, most kinases
examined were found to exhibit developmental regulation. After kinases were
clustered on the basis of similarities in their temporal expression profiles
during mammary development, multiple distinct patterns of expression were
observed. Analysis of these patterns revealed an ordered set of expression
profiles in which successive waves of kinase expression occur during development.
Interestingly, several protein kinases whose expression has previously been
reported to be restricted to tissues other than the mammary gland were isolated
in this screen and found to be expressed in the mammary gland. In aggregate,
these findings suggest that the array of kinases participating in the regulation
of normal mammary development is considerably broader than currently appreciated.
PMID- 10694422
TI - Both nuclear and cytoplasmic components are defective in oocytes of the B6.Y(TIR)
sex-reversed female mouse.
AB - In the mammalian gonadal primordium, activation of the Sry gene on the Y
chromosome initiates a cascade of genetic events leading to testicular
organization whereas its absence results in ovarian differentiation. An exception
occurs when the Y chromosome of Mus musculus domesticus from Tirano, Italy
(Y(TIR)), is placed on the C57BL/6J (B6) genetic background. The B6.Y(TIR)
progeny develop only ovaries or ovotestes despite Sry transcription in fetal
life. Consequently, the XY offspring with bilateral ovaries develop into
apparently normal females, but their eggs fail to develop after fertilization.
Our previous studies have shown that the primary cause of infertility can be
attributed to oocytes rather than their surrounding somatic cells in the XY
ovary. This study attempted to identify the defects in oocytes from the B6.Y(TIR)
female mouse. We examined the developmental potential of embryos from XY and XX
females after exchanging their nuclear components by microsurgery following in
vitro maturation and fertilization. The results suggest that both nuclear and
cytoplasmic components are defective in oocytes from XY females. In the XY fetal
ovary, most germ cells entered meiosis and their autosomes appeared to synapse
normally while the X and Y chromosomes remained unpaired during meiotic prophase.
This lack of X-Y pairing probably caused aneuploidy in some secondary oocytes
following in vitro maturation. However, normal numbers of chromosomes in the rest
of the secondary oocytes indicate that aneuploidy alone can not explain the
nuclear defect in oocytes.
PMID- 10694423
TI - Failure of Myf5 to support myogenic differentiation without myogenin, MyoD, and
MRF4.
AB - The basic helix-loop-helix (bHLH) transcription factors-MyoD, Myf5, myogenin, and
MRF4-can each activate the skeletal muscle-differentiation program in
transfection assays. However, their functions during embryogenesis, as revealed
by gene-knockout studies in mice, are distinct. MyoD and Myf5 have redundant
functions in myoblast specification, whereas myogenin and either MyoD or MRF4 are
required for differentiation. Paradoxically, myoblasts from myogenin mutant or
MyoD/MRF4 double-mutant neonates differentiate normally in vitro, despite their
inability to differentiate in vivo, suggesting that the functions of the myogenic
bHLH factors are influenced by the cellular environment and that the specific
myogenic defects observed in mutant mice do not necessarily reflect essential
functions of these factors. Understanding the individual roles of these factors
is further complicated by their ability to cross-regulate one another's
expression. To investigate the functions of Myf5 in the absence of contributions
from other myogenic bHLH factors, we generated triple-mutant mice lacking
myogenin, MyoD, and MRF4. These mice appear to contain a normal number of
myoblasts, but in contrast to myogenin or MyoD/MRF4 mutants, differentiated
muscle fibers fail to form in vivo and myoblasts from neonates of this triple
mutant genotype are unable to differentiate in vitro. These results suggest that
physiological levels of Myf5 are insufficient to activate the myogenic program in
the absence of other myogenic factors and suggest that specialized functions have
evolved for the myogenic bHLH factors to switch on the complete program of muscle
gene expression.
PMID- 10694424
TI - p27(Kip1) regulates cell cycle withdrawal of late multipotent progenitor cells in
the mammalian retina.
AB - The cyclin-dependent kinase inhibitor protein, p27(Kip1), is necessary for the
timing of cell cycle withdrawal that precedes terminal differentiation in
oligodendrocytes of the optic nerve. Although p27(Kip1) is widely expressed in
the developing central nervous system, it is not known whether this protein has a
similar role in neuronal differentiation. To address this issue, we have examined
the expression and function of p27(Kip1) in the developing retina, a well
characterized part of the central nervous system. p27(Kip1) is expressed in a
pattern coincident with the onset of differentiation of most retinal cell types.
In vitro analyses show that p27(Kip1) accumulation in retinal cells correlates
with cell cycle withdrawal and differentiation, and when overexpressed, p27(Kip1)
inhibits proliferation of the progenitor cells. Furthermore, the histogenesis of
photoreceptors and Muller glia is extended in the retina of p27(Kip1)-deficient
mice. Finally, we examined the adult retinal dysplasia in p27(Kip1)-deficient
mice with cell-type-specific markers. Contrary to previous suggestions that the
dysplasia is caused by excess production of photoreceptors, we suggest that the
dysplasia is due to the displacement of reactive Muller glia into the layer of
photoreceptor outer segments. These results demonstrate that p27(Kip1) is part of
the molecular mechanism that controls the decision of multipotent central nervous
system progenitors to withdraw from the cell cycle. Second, postmitotic Muller
glia have a novel and intrinsic requirement for p27(Kip1) in maintaining their
differentiated state.
PMID- 10694425
TI - P granules in the germ cells of Caenorhabditis elegans adults are associated with
clusters of nuclear pores and contain RNA.
AB - The germ cells, and germ cell precursors, in the nematode Caenorhabditis elegans
contain distinctive granules called P granules. During early embryogenesis, P
granules are segregated asymmetrically into those blastomeres that eventually
produce the germ line. Because of the correlation between P granule distribution
and the development of the germ line, P granules are widely thought to function
in some aspect of germ line specification or differentiation. Most of the
analysis of P granule structure and localization has focused on the early embryo,
when P granules are located in the cytoplasm. However, during most of development
P granules are associated with germ cell nuclei. We report here an
ultrastructural analysis of the nuclear-associated P granules in the germ cells
of the adult hermaphrodite gonad. We show that P granules are tightly associated
with nuclear pores and that the positions of certain structures within the P
granules correspond to the positions of pores on the nuclear envelope. We present
immunocytochemical and ultrastructural data suggesting that P granules can
associate, or remain associated, with pore-like structures even after they detach
from the nuclear envelope during oogenesis. Finally, we show that nuclear
associated P granules in the gonad contain RNA, complementing previous studies
showing that cytoplasmic P granules in embryos contain RNA.
PMID- 10694426
TI - The Golgi apparatus segregates from the lysosomal/acrosomal vesicle during rhesus
spermiogenesis: structural alterations.
AB - The acrosome is an acidic secretory vesicle containing hydrolytic enzymes that
are involved in the sperm's passage across the zona pellucida. Imaging of the
acrosomal vesicle and the Golgi apparatus in live rhesus monkey spermatids was
accomplished by using the vital fluorescent probe LysoTracker DND-26.
Concurrently, the dynamics of living spermatid mitochondria was visualized using
the specific probe MitoTracker CMTRos and LysoTracker DND-26 detected the
acrosomal vesicle from its formation through spermatid differentiation.
LysoTracker DND-26 also labeled the Golgi apparatus in spermatogenic cells. In
spermatocytes the Golgi is spherical and, in round spermatids, it is localized
over the acrosomal vesicle, as confirmed by using polyclonal antibodies against
Golgin-95/GM130, Golgin-97, and Golgin-160. Using both live LysoTracker DND-26
imaging and Golgi antibodies, we found that the Golgi apparatus is cast off from
the acrosomal vesicle and migrates toward the sperm tail in elongated spermatids.
The Golgi is discarded in the cytoplasmic droplet and is undetectable in mature
ejaculated spermatozoa. The combined utilization of three vital fluorescent
probes (Hoechst 33342, LysoTracker DND-26, and MitoTracker CMTRos) permits the
dynamic imaging of four organelles during primate spermiogenesis: the nucleus,
the mitochondria, the acrosomal vesicle, and the Golgi apparatus.
PMID- 10694427
TI - Two distinct cell populations in the floor plate of the zebrafish are induced by
different pathways.
AB - The floor plate is a morphologically distinct structure of epithelial cells
situated along the midline of the ventral spinal cord in vertebrates. It is a
source of guidance molecules directing the growth of axons along and across the
midline of the neural tube. In the zebrafish, the floor plate is about three
cells wide and composed of cuboidal cells. Two cell populations can be
distinguished by the expression patterns of several marker genes, including sonic
hedgehog (shh) and the fork head-domain gene fkd4: a single row of medial floor
plate (MFP) cells, expressing both shh and fkd4, is flanked by rows of lateral
floor plate (LFP) cells that express fkd4 but not shh. Systematic mutant searches
in zebrafish embryos have identified a number of genes, mutations in which
visibly reduce the floor plate. In these mutants either the MFP or the LFP cells
are absent, as revealed by the analysis of the shh and fkd4 expression patterns.
MFP cells are absent, but LFP cells are present, in mutants of cyclops, one-eyed
pinhead, and schmalspur, whose development of midline structures is affected. LFP
cells are absent, but MFP cells are present, in mutants of four genes, sonic you,
you, you-too, and chameleon, collectively called the you-type genes. This group
of mutants also shows defects in patterning of the paraxial mesoderm, causing U-
instead of V-shaped somites. One of the you-type genes, sonic you, was recently
shown to encode the zebrafish Shh protein, suggesting that the you-type genes
encode components of the Shh signaling pathway. It has been shown previously that
in the zebrafish shh is required for the induction of LFP cells, but not for the
development of MFP cells. This conclusion is supported by the finding that
injection of shh RNA causes an increase in the number of LFP, but not MFP cells.
Embryos mutant for iguana, detour, and umleitung share the lack of LFP cells with
you-type mutants while somite patterning is not severely affected. In mutants
that fail to develop a notochord, MFP cells may be present, but are always
surrounded by LFP cells. These data indicate that shh, expressed in the notochord
and/or the MFP cells, induces the formation of LFP cells. In embryos doubly
mutant for cyclops (cyc) and sonic you (syu) both LFP and MFP cells are deleted.
The number of primary motor neurons is strongly reduced in cyc;syu double
mutants, while almost normal in single mutants, suggesting that the two different
pathways have overlapping functions in the induction of primary motor neurons.
PMID- 10694428
TI - Growth cones utilize both widespread and local directional cues in the zebrafish
brain.
AB - The distribution of cues that provide directional information for specific growth
cones in the zebrafish brain was functionally assayed by transplanting epiphysial
neurons to ectopic locations in the embryonic brain followed by determining the
pathways taken by the donor axons. Epiphysial axons normally first extend
ventrally from their position in the dorsal diencephalon and then turn and extend
anteriorly in the ventral diencephalon. When transplanted to ectopic sites at
other axial levels of the brain, where in principle the axons could extend in any
direction, epiphysial axons consistently extended ventrally. Furthermore,
following initial ventral extension ectopic epiphysial axons turned randomly in
the anterior and posterior directions. These results suggest that the cues for
ventral extension are widely distributed along the rostrocaudal axis of the
zebrafish brain, but the cues for subsequent anterior extension are restricted to
the site where the epiphysial axons normally turn longitudinally.
PMID- 10694429
TI - Fate mapping of the mouse prosencephalic neural plate.
AB - Little is known about the behavior of cells within the anterior neural plate or
tube in developing mammalian embryos in utero due to technical limitations. Here
we labeled neuroepithelial cells with vital dye and traced their siblings for 1
or 2 days using the whole-embryo culture system. The results demonstrated that
rostral cell movement from the midbrain to the forebrain in the mouse neural
plate was restricted at the boundary by the five-somite stage. Coincident with
restriction of cell intermingling, expression of a transcription factor, Pax6,
and a cell adhesion molecule, cadherin-6, commmenced to demarcate the forebrain
compartment. Within this compartment, we also mapped several prospective regions
of the telencephalon and diencephalon to the eyes. The fate map of the mouse
prosencephalic neural plate was very similar to those of other vertebrates,
providing evidence that mammalian-specific brain structures, represented in the
cerebral neocortex, could evenly develop along the conserved framework of
neuromeres.
PMID- 10694430
TI - Regulation of microphthalmia-associated transcription factor MITF protein levels
by association with the ubiquitin-conjugating enzyme hUBC9.
AB - The basic helix-loop-helix/leucine zipper (bHLH/ZIP) microphthalmia-associated
transcription factor (MITF) regulates transcription of genes encoding enzymes
essential for melanin biosynthesis in melanocytes and retinal pigmented
epithelial cells. To determine how MITF activity is regulated, we used the yeast
two-hybrid system to identify proteins expressed by human melanoma cells that
interact with MITF. The majority of clones that showed positive interaction with
a 158-amino-acid region of MITF containing the bHLH/ZIP domain (aa 168-325)
encoded the ubiquitin conjugating enzyme hUBC9. The association of MITF with
hUBC9 was further confirmed by an in vitro GST pull-down assay. Although hUBC9 is
known to interact preferentially with SENTRIN/SUMO1, in vitro
transcription/translation analysis demonstrated greater association of MITF with
ubiquitin than with SENTRIN. Importantly, cotransfection of MITF and hUBC9
expression vectors resulted in MITF protein degradation. MITF protein was
stabilized by the proteasome inhibitor MG132, indicating the role of the
ubiquitin-proteasome system in MITF degradation. Serine 73, which is located in a
region rich in proline, glutamic acid, serine, and threonine (PEST), regulates
MITF protein stability, since a serine to alanine mutation prevented hUBC9
mediated MITF (S73A) degradation. Furthermore, we identified lysine 201 as a
potential ubiquitination site. A lysine to arginine mutation abolished MITF
(K201R) degradation by hUBC9 in vivo. Our experiments indicate that by targeting
MITF for proteasome degradation, hUBC9 is a critical regulator of melanocyte
differentiation.
PMID- 10694431
TI - Activation of a cysteine protease in MCF-7 and T47D breast cancer cells during
beta-lapachone-mediated apoptosis.
AB - beta-Lapachone (beta-lap) effectively killed MCF-7 and T47D cell lines via
apoptosis in a cell-cycle-independent manner. However, the mechanism by which
this compound activated downstream proteolytic execution processes were studied.
At low concentrations, beta-lap activated the caspase-mediated pathway, similar
to the topoisomerase I poison, topotecan; apoptotic reactions caused by both
agents at these doses were inhibited by zVAD-fmk. However at higher doses of beta
lap, a novel non-caspase-mediated "atypical" cleavage of PARP (i.e., an
approximately 60-kDa cleavage fragment) was observed. Atypical PARP cleavage
directly correlated with apoptosis in MCF-7 cells and was inhibited by the global
cysteine protease inhibitors iodoacetamide and N-ethylmaleimide. This cleavage
was insensitive to inhibitors of caspases, granzyme B, cathepsins B and L,
trypsin, and chymotrypsin-like proteases. The protease responsible appears to be
calcium-dependent and the concomitant cleavage of PARP and p53 was consistent
with a beta-lap-mediated activation of calpain. beta-Lap exposure also stimulated
the cleavage of lamin B, a putative caspase 6 substrate. Reexpression of
procaspase-3 into caspase-3-null MCF-7 cells did not affect this atypical PARP
proteolytic pathway. These findings demonstrate that beta-lap kills cells through
the cell-cycle-independent activation of a noncaspase proteolytic pathway.
PMID- 10694432
TI - Effects of keratin filament disruption on exocrine pancreas-stimulated secretion
and susceptibility to injury.
AB - Disruption or absence of hepatocyte keratins 8 and 18 is associated with chronic
hepatitis, marked hepatocyte fragility, and a significant predisposition to
stress-induced liver injury. In contrast, pancreatic keratin disruption in
transgenic mice that express keratin 18 Arg89 --> Cys (K18C) is not associated
with an obvious pancreatic pathology. We compared the effects of keratin filament
disruption on pancreatic acini or acinar cell viability, and on cholecystokinin
(CCK)-stimulated secretion, in transgenic mice that overexpress wild-type keratin
18 and harbor normal extended keratin filaments (TG2) and K18C mice. We also
compared the response of these mice to pancreatitis induced by a choline
deficient ethionine-supplemented diet or by caerulein. Despite extensive
cytoplasmic keratin filament disruption, the apicolateral keratin filament
bundles appear intact in the acinar pancreas of K18C mice, as determined
ultrastructurally and by light microscopy. No significant pancreatitis-associated
histologic, serologic, or F-actin/keratin apicolateral redistribution differences
were noted between TG2 and K18C mice. Acinar cell viability and yield after
collagenase digestion were lower in K18C than in TG2 mice, but the yields of
intact acini and their (125)I-CCK uptake and responses to CCK-stimulated
secretion were similar. Our results indicate that keratin filament reorganization
is a normal physiologic response to pancreatic cell injury, but an intact keratin
cytoplasmic filament network is not as essential in protection from cell injury
as in the liver. These findings raise the possibility that the abundant
apicolateral acinar keratin filaments, which are not as evident in hepatocytes,
may play the cytoprotective role that is seen in liver and other tissues.
Alternatively, identical keratins may function differently in different tissues.
PMID- 10694433
TI - Increased activity of the protein kinase C-delta holoenzyme in the cytoplasmic
particulate fraction precedes the activation of caspases in polyomavirus
transformed pyF111 rat fibroblasts exposed to calphostin C or topoisomerase-II
inhibitors.
AB - A caspase-mediated release of the 40-kDa catalytic fragment of the delta isoform
(CF-delta) of protein kinase C (PKC-delta) is involved in apoptosis, but its
actual role in apoptosis development is still unknown. In an effort to understand
this role, we have used polyomavirus-transformed pyF111 rat fibroblasts, which
are hypersusceptible to apoptosis as they constitutively hyperexpress PKC-delta,
but cannot make the antiapoptotic Bcl-2 and Bcl-X(L) proteins, while making the
proapoptotic Bax protein. Calphostin C is reportedly both a specific inhibitor of
PKC-delta activity (C. Keenan, N. Goode, and C. Pears, 1997, FEBS Lett. 415, 101
108) and an effective apoptogen (M. Murata et al., 1997, Cell. Mol. Life Sci. 53,
737-743). Exposure of pyF111 cells to calphostin C (75 nM) stimulated the
translocation of the PKC-delta holoenzyme (holo-PKC-delta) onto the cytoplasmic
particulate (CP) fraction between 15 and 45 min, which was after the release of
mitochondrial cytochrome c but before the activation of cytoplasmic DEVD-specific
caspases. The CF-delta fragment started accumulating only between 2 and 4 h,
while apoptosis occurred mostly within 6 h. Incubating pyF111 cells with the much
slower acting, apoptogenic topoisomerase-II inhibitors etoposide (VP-16) and
teniposide (VM-26) also caused within 6 h a doubling of the CP-bound holo-PKC
delta-related activity but with no significant translocation of the holoenzyme to
the CP fraction. Again this occurred after the release of cytochrome c but before
the activation of DEVDases and the accumulation of the CF-delta. However, while
calphostin C did not affect the delta-related activity in the nuclear membrane
(NM) and nucleoplasmic (NP) fractions, VP-16 and VM-26 caused a prompt, large,
and irreversible drop in the delta activity at the NM and a transient surge
followed by a fall in the NP-associated activity. Hence, a surge of CP-anchored
holo-PKC-delta activity is a common part of the signals given by various
apoptogenic drugs to pyF111 cells. On the other hand, inhibition of delta-related
activity, first at the NM and then in the NP fraction, is a specific feature only
of the signals given by apoptogenic DNA-damaging agents.
PMID- 10694434
TI - Cdk1 is essential for mammalian cyclosome/APC regulation.
AB - The cyclosome/APC (anaphase-promoting complex), the major component of cell-cycle
specific ubiquitin-mediated proteolysis of mitotic cyclins and of other cell
cycle proteins, is essential for sister chromatid separation and for exit from
mitosis. Cyclosome activity and substrate specificity are modulated by
phosphorylation and by transient interactions with Fizzy/cdc20 (Fzy) and Fizzy
related/Hct1/Cdh1 (Fzr). This regulation has been studied so far in Drosophila
embryos, in yeast, and in cell-free extracts in vitro. Studying cyclosome
regulation in mammalian cells in vivo we found that both Fzr overexpression and
Cdk1 inhibition can override the prometaphase checkpoint. We further show that
Fzr activation of the cyclosome is negatively regulated by Cdk1. Finally, we show
that the mammalian cdc14 phosphatase, like its budding yeast homologue, plays a
role in cyclosome pathway regulation. These results suggest that Cdk1 is
essential for coupling various activities of the cyclosome and in particular for
preventing Fzr from short-circuiting the spindle pole checkpoint. Cdk1-cyclin B
is thus an inhibitor, activator, and substrate of the cyclosome.
PMID- 10694435
TI - Presenilin 2 expression in neuronal cells: induction during differentiation of
embryonic carcinoma cells.
AB - Mutations in the presenilin 1 and 2 (PS1 and PS2) genes cause most cases of early
onset Alzheimer's disease. The genes encode two homologous multipass membrane
proteins. Since the endogenous expression of PS2 has been poorly analyzed to
date, we studied PS2 expression and localization in cultured human neuroblastoma
cells and mouse neuronal cells. PS2 was mainly detected as a full-length protein
of about 52 kDa in these cells and in brain, in contrast to PS1 that is mainly
detected as endoproteolytic N-terminal and C-terminal fragments. Using
immunofluorescence we found that like PS1, PS2 colocalized with markers of the
endoplasmic reticulum-Golgi intermediate compartment, ERGIC-53 and beta-COP.
Double labeling for PS1 and PS2 indicated that both proteins are colocalized in
neuroblastoma SH-SY5Y cells. To study PS2 expression during differentiation,
mouse embryonic carcinoma P19 cells were treated with retinoic acid. We found
minimal PS2 expression in undifferentiated cells, an increase from day 2, and a
maximum at day 8 after treatment. PS1 expression remained constant during this
period. The differential expression of PS1 and PS2 within the P19 cells following
retinoic acid treatment indicates different utilization or temporal requirements
for these proteins during neuronal differentiation.
PMID- 10694436
TI - Analysis of beta-catenin aggregation and localization using GFP fusion proteins:
nuclear import of alpha-catenin by the beta-catenin/Tcf complex.
AB - beta-Catenin plays essential roles in cell adhesion, by associating with
cadherins, and as a signaling molecule, by interacting with the Tcf/LEF-1 family
of transcription factors. In order to study the protein-protein interactions of
beta-catenin in living cells, we fused it to green fluorescent protein (GFP). GFP
beta-catenin was incorporated into cell junctions but also accumulated in the
nucleus, where it formed rod-like structures. The carboxyl-terminal armadillo
repeats of GFP-beta-catenin were sufficient for nuclear localization, but
formation of rods required the armadillo repeats and sequences in both the amino-
and the carboxyl-terminal domains. Rod formation was prevented by coexpression of
N-cadherin, APC, and Tcf-4, which bind to the armadillo repeats of beta-catenin,
but not by coexpression of alpha-catenin, although alpha-catenin expression did
prevent accumulation of beta-catenin in the nucleus. Interestingly, when alpha
catenin, beta-catenin, and Tcf-4 were coexpressed they colocalized in the
nucleus, and this correlated with a decrease in beta-catenin/Tcf-dependent
transcriptional activity. These results indicate that binding of beta-catenin to
Tcf-4 overrides the function of alpha-catenin to sequester beta-catenin in the
cytoplasm and suggest that alpha-catenin can regulate beta-catenin signaling in
the nucleus.
PMID- 10694437
TI - Caveolin internalization by heat shock or hyperosmotic shock.
AB - We investigated the cellular localization of caveolin, a landmark protein of
caveolae, by indirect immunofluorescence after heat shock or hyperosmotic shock.
Caveolin was internalized to the perinucleus by heat shock (43 degrees C) and
relocalized in the plasma membrane after recovery of NIH3T3 cells at 37 degrees C
for 4 h. The caveolin internalization was also observed after cells were exposed
to hyperosmotic shock. Caveolin disappeared from detergent-insoluble complexes in
the heat-shocked cells, but alkaline phosphatase was still there, suggesting that
their responses to heat shock are quite different even though both of them were
enriched in detergent-insoluble complexes of normal cells. Caveolin was
internalized by the actin depolymerizer cytochalasin D, but not by the tubulin
depolymerizer nocodazole. In addition, cellular exposure to hydrogen peroxide
caused caveolin internalization along with disintegrated microfilaments and
intact microtubules. Since cellular exposure to heat shock showed disintegrated
microfilaments but intact microtubules, caveolin internalization might be due to
depolymerized microfilaments. When cells were exposed to heat shock and allowed
to recover for 4 h, actin depolymerization and caveolin internalization were not
induced by a second heat shock, suggesting that some heat shock protein(s) might
prevent actin depolymerization and caveolin internalization.
PMID- 10694438
TI - Spatial distribution of GC- and AT-rich DNA sequences within human chromosome
territories.
AB - Previous topological analyses of DNA sequence organization in the interphase
chromosome mainly focused on the spatial distribution of individual gene copies
within chromosome territories. In order to achieve a more comprehensive view into
the subchromosomal arrangement of DNA, we isolated the GC-richest/gene-richest
fraction (H3 isochores) as well as AT-richest/gene-poorest fraction of human
genomic DNA (L1+L2 isochores) and visualized the respective DNA within individual
chromosome territories by means of dual-color FISH. Application of confocal laser
scanning microscopy and dedicated 3D image analysis software, which
differentiated territory subvolumes by peeling shells one voxel in width,
revealed a significant difference in the intraterritorial distribution of these
two DNA sequence classes. While the H3 isochores were found localized in all
subvolumes of the territories at similar frequency, simultaneously detected L1+L2
isochores were observed more to the interior of the same chromosome territories.
Thus the GC-rich sequences display a much higher variability in their
intraterritorial localization than AT-rich DNA fragments.
PMID- 10694439
TI - Single amino acid (arginine) deprivation induces G1 arrest associated with
inhibition of cdk4 expression in cultured human diploid fibroblasts.
AB - Withdrawal of a single amino acid (arginine) from freely cycling early passage
primary human fibroblasts caused a halt to proliferation, characterized by an
accumulation of cells in the G1 phase of the cell cycle. This arrest was
accompanied by the suppression of cyclin D1- and cyclin E-associated kinase
activities and the appearance of hypophosphorylated retinoblastoma protein.
Arginine-deprived cells remained viable for in excess of 4 days and could be made
to synchronously reenter the cell cycle by restoration of the amino acid, with
kinetics characteristic of exit from a quiescent state. Stimulation of cells
arrested by serum withdrawal did not result in S-phase entry when arginine was
omitted from the culture medium. Although cyclin D1 accumulated on normal
schedule, cdk4, which increased following restimulation in amino acid-replete
medium, was not induced when arginine was absent. These results suggest that
arginine deprivation-in common with other "suboptimal" conditions-inhibits the
passage of normal human cells through the restriction point and implicate cdk4 as
the key regulatory element in amino acid-sensitive cell cycle control.
PMID- 10694440
TI - Both increased stability and transcription contribute to the induction of the
urokinase plasminogen activator receptor (uPAR) message by hypoxia.
AB - Both hypoxia and overexpression of the urokinase plasminogen activator receptor
(uPAR) are associated with a poor clinical outcome in human cancers. Hypoxia has
been shown to induce uPAR expression in breast cancer cells and to increase their
invasion through Matrigel, a phenomenon which can be blocked using an anti-uPAR
antibody. We examined expression of uPAR mRNA in MCF7 human breast carcinoma
cells under hypoxia and found that an increase in the level of the message could
be detected at 1% oxygen but was most marked at 0.2 or 0.05% oxygen with an
induction of 9- to 20-fold over baseline. To determine whether changes in RNA
stability contributed to this dramatic increase, we used actinomycin D to inhibit
transcription and found that the half-life of the message was much longer under
hypoxic conditions (approximately 10 h) than during reoxygenation (approximately
2 h). Transient transfections using a luciferase reporter construct containing 2
kbp of the mouse uPAR promoter showed that promoter activity increased up to 5
fold after exposure to 0.2% oxygen. Thus, hypoxic induction of the uPAR message
in MCF7 cells is due to both mRNA stabilization and increased transcriptional
activation.
PMID- 10694441
TI - A region containing a proline-rich motif targets sG(i2) to the golgi apparatus.
AB - The central function of heterotrimeric GTP-binding proteins (G proteins) is the
transduction of extracellular signals, via membrane receptors, leading to the
activation of intracellular effectors. In addition to being associated with the
plasma membrane, the alpha subunits of some of these proteins have also been
localized in intracellular compartments. The mRNA of the G-protein inhibitory
alpha subunit 2 (G(alphai2)) encodes two proteins, G(alphai2) and sG(i2), by an
alternative splicing mechanism. sG(i2) differs from G(alphai2) in the C-terminal
region and localizes in the Golgi in contrast to the plasma membrane localization
of G(alphai2). In this paper we show that the sequence specific to sG(i2) can
direct the Golgi localization of other G(alphai) subunits, but not of the
stimulatory subunit G(alphas) or of a secreted protein. This indicates that, in
addition to the sG(i2) C-terminus, sequences located elsewhere in the protein are
required to determine the Golgi localization. Inside the sG(i2) C-terminal region
we have identified a 14-amino-acid proline-rich motif which specifies the Golgi
localization. Finally, we show that the sG(i2) subunit, once activated, leaves
the Golgi to be localized in the endoplasmic reticulum.
PMID- 10694442
TI - A C-terminal carbohydrate-binding domain in the endothelial cell regulatory
protein, pigpen: new function for an EWS family member.
AB - The potential for encoding information in carbohydrate (CHO) structures has long
been recognized. Selective CHO-binding proteins known as lectins and the
biological events they mediate are well known. However, many lectins were
originally discovered for biological activities other than saccharide binding,
and only subsequently was it realized that one or more of their key functions
were mediated by specific CHO recognition. Our previous observations suggested
that the nuclear protein pigpen had an affinity for CHO structures. This would
represent a new attribute for proteins of the EWS (Ewing's sarcoma) family, of
which pigpen is a member. In this study we demonstrate that a CHO-binding domain
resides in the C-terminus of the molecule and can be preferentially inhibited by
saccharides, most notably N-acetyl-d-galactosamine (GalNAc) and the GalNAc
containing polysaccharide, chondroitin sulfate. Ligand blotting experiments were
subsequently performed with fractionated, [(3)H]galactose-labeled cells to
demonstrate the presence of chondroitin sulfate-inhibitable endogenous CHO
ligands for pigpen in endothelial nuclei. Finally, microinjection of
polysaccharide competitor into the nucleus of cultured endothelial cells resulted
in a loss of pigpen focal accumulations, suggesting that the CHO-binding activity
may be instrumental in subcellular localization of the protein. In summary, our
results show ligand preference and domain specificity for pigpen's CHO affinity
and provide initial evidence for physiological ligands and function. They may
also shed new light on the mechanisms of oncogenic transformation involving EWS
proteins.
PMID- 10694443
TI - Galectin-3 expression and subcellular localization in senescent human
fibroblasts.
AB - Galectin-3 is a galactose/lactose-binding protein (M(r) approximately 30,000),
identified as a required factor in the splicing of pre-mRNA. In the LG1 strain of
human diploid fibroblasts, galectin-3 could be found in both the nucleus and the
cytoplasm of young, proliferating cells. In contrast, the protein was
predominantly cytoplasmic in senescent LG1 cells that have lost replicative
competence through in vitro culture. Incubation of young cells with leptomycin B,
a drug that disrupts the interaction between the leucine-rich nuclear export
signal and its receptor, resulted in the accumulation of galectin-3 inside the
nucleus. In senescent cells, galectin-3 staining remained cytoplasmic even in the
presence of the drug, thus suggesting that the observed localization in the
cytoplasm was due to a lack of nuclear import. In heterodikaryons derived from
fusion of young and senescent LG1 cells, the predominant phenotype was galectin-3
in both nuclei. These results suggest that senescent LG1 cells might lack a
factor(s) specifically required for galectin-3 nuclear import.
PMID- 10694444
TI - Expression of the sodium/calcium exchanger in mammalian skeletal muscle cells in
primary culture.
AB - Previous investigations have demonstrated molecular and functional expression, at
early phases of development of skeletal muscle cells in primary culture, of
cardiac isoforms of proteins involved in calcium transport and regulation, like
the L-type calcium channel. Here the expression of the cardiac isoform of the
Na(+)/Ca(2+) exchanger (NCX1) was studied in skeletal muscle cells developing in
vitro, by using biochemical, immunological, and electrophysiological techniques.
Northern and Western blot experiments revealed the presence of this cardiac
exchanger and its increasing expression during the early phases of development.
Confocal imaging of myotubes showed an NCX1 distribution that was predominantly
sarcolemmal. The whole-cell patch-clamp technique allowed us to record ionic
currents, the direction and the amplitude of which depended on extracellular
sodium and calcium concentrations. The developmental changes of this functional
expression could be correlated with the molecular NCX1 expression changes. Taken
together these data demonstrate the presence of the NCX1 isoform of the
Na(+)/Ca(2+) exchanger during in vitro myogenesis and reinforce the theory that
significant levels of cardiac-type proteins are transiently expressed during the
early phases of the skeletal muscle cell development.
PMID- 10694445
TI - The role of extracellular and cytoplasmic splice domains of alpha7-integrin in
cell adhesion and migration on laminins.
AB - The major laminin-binding integrin of skeletal, smooth, and heart muscle is
alpha7beta1-integrin, which is structurally related to alpha6beta1. It occurs in
three cytoplasmic splice variants (alpha7A, -B, and -C) and two extracellular
forms (X1 and X2) which are developmentally regulated and differentially
expressed in skeletal muscle. Previously, we have shown that ectopic expression
of the alpha7beta-integrin splice variant in nonmotile HEK293 cells specifically
induced cell locomotion on laminin-1 but not on fibronectin. To investigate the
specificity and the mechanism of the alpha7-mediated cell motility, we expressed
the three alpha7-chain cytoplasmic splice variants, as well as alpha6A- and
alpha6B-integrin subunits in HEK293 cells. Here we show that all three alpha7
splice variants (containing the X2 domain), as well as alpha6A and alpha6B,
promote cell attachment and stimulate cell motility on laminin-1 and its E8
fragment. Deletion of the cytoplasmic domain (excluding the GFFKR consensus
sequence) from alpha7B resulted in a loss of the motility-enhancing effect. On
laminin-2/4 (merosin), the predominant isoform in mature skeletal muscle, only
alpha7-expressing cells showed enhanced motility, whereas cells transfected with
alpha6A and alpha6B neither attached nor migrated on laminin-2. Adhesion of
alpha7-expressing cells to both laminin-1 and laminin-2 was specifically
inhibited by a new monoclonal antibody (6A11) specific for alpha7. Expression of
the two extracellular splice variants alpha7X1 and alpha7X2 in HEK293 cells
conferred different motilities on laminin isoforms: Whereas alpha7X2B promoted
cell migration on both laminin-1 and laminin-2, alpha7X1B supported motility only
on laminin-2 and not on laminin-1, although both X1 and X2 splice variants
revealed similar adhesion rates to laminin-1 and -2. Fluorescence-activated cell
sorter analysis revealed a dramatic reduction of surface expression of alpha6
integrin subunits after alpha7A or -B transfection; also, surface expression of
alpha1-, alpha3-, and alpha5-integrins was significantly reduced. These results
demonstrate selective responses of alpha6- and alpha7-integrins and of the alpha7
splice variants to laminin-1 and -2 and indicate differential roles in laminin
controlled cell adhesion and migration.
PMID- 10694446
TI - Differential localization of ICAD-L and ICAD-S in cells due to removal of a C
terminal NLS from ICAD-L by alternative splicing.
AB - CAD/CPAN/DFF40 is an apoptotic nuclease that is associated with the regulatory
subunit ICAD/DFF in healthy cells. ICAD has two forms, ICAD-L/DFF45 and ICAD
S/DFF35, which are transcribed from a single gene by alternative splicing. They
differ at the C-terminus: 70 amino acids of ICAD-L are replaced by 4 different
amino acids in ICAD-S. We previously showed that both transfected and endogenous
ICAD-L are nuclear; however, the localization of ICAD and CAD remains
controversial and an important issue to clarify. Here we present the evidence
that ICAD-L is nuclear due to the presence of an autonomous nuclear localization
signal located in the C-terminal 20 amino acids. This NLS is missing from ICAD-S,
which is distributed throughout the cell. We also showed that a GFP:CAD fusion
protein is located in the nucleus of transfected cells.
PMID- 10694447
TI - Radiation-induced centrosome overduplication and multiple mitotic spindles in
human tumor cells.
AB - The centrosome is a highly regulated organelle and its proper duplication is
indispensable for the formation of bipolar mitotic spindles and balanced
chromosome segregation. To elucidate a possible linkage between centrosome
duplication and radiation-induced nuclear damage, we examined centrosome dynamics
in U2-OS osteosarcoma cells following gamma-irradiation. Nearly all control cells
contained one or two centrosomes, and at mitosis more than 97% of the cells
displayed typical bipolar spindles. In contrast, over 20% of cells at 48 h after
10 Gy gamma-irradiation contained more than two centrosomes, and 60% of the
mitotic cells showed aberrant spindles organized by multiple poles. Remarkably,
the cells with multiple centrosomes frequently exhibited changes in size and/or
morphology of the nucleus, including micronuclei formation. We conclude that
abnormal centrosome duplication could be one of the key events involved in
nuclear fragmentation and perhaps even cell death following irradiation.
PMID- 10694448
TI - Sox9 expression during chondrogenesis in micromass cultures of embryonic limb
mesenchyme.
AB - Sox9 plays a crucial role in chondrogenesis. It encodes an HMG-domain
transcription factor that activates an enhancer in the gene for type II collagen
(Col2a1), a principal cartilage matrix protein. We have characterized the
temporal pattern of Sox9 RNA expression in micromass culture, a widely used in
vitro model for the analysis of embryonic cartilage differentiation. Cultures
were prepared from distal subridge mesenchyme of the stage 24/25 chick embryo
wing bud, which undergoes uniform chondrogenic differentiation in vitro. The
early "prechondrogenic" phase of culture was characterized by the activation of
Sox9 RNA expression, which preceded detectable upregulation of Col2a1
transcription. Sox9 RNA levels peaked between 20 and 65 h of culture, a phase of
progressive Col2a1 transcript accumulation, then declined in the mature cartilage
of 120-h cultures. Staurosporine treatment enhanced chondrogenesis in micromass
culture by inducing a rapid quantitative increase in Sox9 transcript levels.
However, PMA, a phorbol ester that inhibits Col2a1 expression and chondrocyte
differentiation, had an unexpectedly modest effect on Sox9 RNA accumulation.
PMID- 10694449
TI - Editorial
PMID- 10694450
TI - Antibody modeling: implications for engineering and design.
AB - Our understanding of the rules relating sequence to structure in antibodies has
led to the development of accurate knowledge-based procedures for antibody
modeling. Information gained from the analysis of antibody structures has been
successfully exploited to engineer antibody-like molecules endowed with
prescribed properties, such as increased stability or different specificity, many
of which have a broad spectrum of applications both in therapy and in research.
Here we describe a knowledge-based procedure for the prediction of the antibody
variable domains, based on the canonical structures method for the antigen
binding site, and discuss its expected accuracy and limitations. The rational
design of antibody-based molecules is illustrated using as an example one of the
most widely employed modifications of antibody structures: the humanization of
animal-derived antibodies to reduce their immunogenicity for serotherapy in
humans.
PMID- 10694451
TI - Automated docking of ligands to antibodies: methods and applications.
AB - Many approaches to studying protein-ligand interactions by computational docking
are currently available. Given the structures of a protein and a ligand, the
ultimate goal of all docking methods is to predict the structure of the resulting
complex. This requires a suitable representation of molecular structures and
properties, search algorithms to efficiently scan the configuration space for
favorable interaction geometries, and accurate scoring functions to evaluate and
rank the generated orientations. For many of the available methods, tests on
experimentally known antibody-antigen or antibody-hapten complexes have appeared
in the literature. In addition, some of them have been used in predictive studies
on antibody-ligand interactions to provide structural insights where adequate
experimental information is missing. The AutoDock program is presented as example
of a method for flexibly docking ligands to antibodies. Applying parameters of
the second-generation AMBER force field, three antibody-hapten complexes (AN02,
DB3, NC6.8) are used as new test cases to analyze the ability of the method to
reproduce experimental findings. The X-ray structures could be reconstituted and
the corresponding solutions were ranked with best energy score in all cases.
Docking to the free instead of the complexed NC6.8 structure indicated the limits
of the rigid protein treatment, although fairly good guesses about the location
of the binding site and the contact residues could still be obtained if
conformational flexibility was allowed at least in the ligand.
PMID- 10694452
TI - Continuum electrostatic methods applied to pH-dependent properties of antibody
antigen association.
AB - Protein association events are a critical component of the functioning of
biological systems. Antibody/antigen association, which involves extraordinarily
specific interactions, has been a paradigm for the study of structural factors
and intermolecular forces controlling protein-protein association. As new
experimental approaches to the study of antibody/antigen affinity have become
routine, and as more structures of complexes of antibodies and their antigens
have become available, it has become possible to use computational approaches to
study these interactions. Electrostatic interactions are known to play an
important role in protein complex formation. In this review, we focus on the use
of continuum electrostatic methods to compute pH-dependent properties of proteins
and discuss the use of these methods in the study of antibody/antigen complexes.
PMID- 10694453
TI - Experimental design for analysis of complex kinetics using surface plasmon
resonance.
AB - Using BIAcore surface plasmon resonance technology, we found that the real-time
association kinetics of Fabs specific for hen egg-white lysozyme did not conform
to a 1:1 Langmuir association model. Heterogeneity of the components is not the
source of the complex kinetics. Informed by independent structural data
suggesting conformational flexibility differences among these antibodies, we
chose global mathematical analysis based on a two-phase model, consistent with
the encounter-docking view of protein-protein associations. Experimental
association times (T(a)) from 2 to 250 min revealed that initial dissociation
rates decreased with increasing T(a), confirming a multiphasic association. The
relationship between observed dissociation rate and T(a) is characteristic of
each antibody-antigen complex. We define a new parameter, T(50), the time at
which the encounter and final complexes are of equimolar concentration. The
observed T(50) is a function of analyte concentration and the encounter and
docking rate constants. Simulations showed that when the ligand is saturated at
high analyte concentrations, T(50) reaches a minimum value, T(50)(MIN), which can
be used to compare antigen-antibody complexes. For high-affinity complexes with
rapid rearrangement to a stable complex, T(50)(MIN) approaches T(1/2) of the
rearrangement forward rate constant. We conclude that experiments with a range of
T(a) are essential to assess the nature of the kinetics, regardless of whether a
two-state or 1:1 model is applicable. We suggest this strategy because each T(a)
potentially reveals a different distribution of molecular states; for two-step
analysis, a range of T(a) that brackets T(50) is optimal.
PMID- 10694454
TI - Application of surface plasmon resonance toward studies of low-molecular-weight
antigen-antibody binding interactions.
AB - Methods for studying low-molecular-weight antigen-antibody binding interactions
using surface plasmon resonance detection are presented. The experimental
parameters most relevant to studies of low-molecular-weight antigen-antibody
binding interactions are discussed. Direct kinetic analysis of the binding
interactions is most informative, providing both apparent association and
dissociation rate constants from which equilibrium constants can be calculated.
Equilibrium analysis, including steady-state and solution affinity studies,
offers an alternative approach to direct kinetic analysis when knowledge of the
individual kinetic rate constants is not required or difficult to determine. The
various methods are illustrated by studies of an anti-T(4) Fab fragment binding
interaction with several thyroxine analogs. The methods utilized were dependent
on the affinity of the interaction. The high-affinity anti-T(4) Fab fragment/l
T(4) binding interaction was evaluated using direct kinetic analysis. An
intermediate affinity anti-T(4) Fab fragment/l-T(3) binding interaction was
evaluated using a combination of direct kinetic analysis, steady-state analysis,
and solution affinity analysis. The relatively weak anti-T(4) Fab fragment/l-T(2)
binding interaction was evaluated using steady-state and solution affinity
analysis protocols. Several thyroxine tracers that could not be immobilized to a
biosensor surface were also evaluated via the solution affinity format. In cases
where a given binding interaction was examined using multiple methods the results
were comparable.
PMID- 10694455
TI - Force probe measurements of antibody-antigen interactions.
AB - The surface force apparatus has been used to quantify directly the forces that
govern the interactions between proteins and ligands. In this work, we describe
the measured interactions between the antigen fluorescein and the Fab' fragment
of the monoclonal 4-4-20 anti-fluorescyl IgG antibody. Here we first describe the
use of the surface force apparatus to demonstrate directly the impact of the
charge composition in the region of the antibody binding site on the antibody
interactions. Several approaches are described for immobilizing antigens,
antibodies, and proteins in general for direct force measurements. The measured
force profiles presented are accompanied by an extensive discussion of protocols
used to analyze the force-distance curves and to interpret them in terms of the
antibody structure. In addition to long-range electrostatic forces, we also
consider short-range forces that can affect the strength of adhesion between the
Fab' and immobilized fluorescein. The latter investigations demonstrate the
influence of interfacial properties on the recognition of surface-bound antigens.
PMID- 10694456
TI - Optical spectroscopy in studies of antibody-hapten interactions.
AB - This article describes the use of optical spectroscopy in studying antibody
hapten interactions and in determining the equilibrium binding constants. Along
with equilibrium binding data, spectroscopic tools often deliver structural
information on binding-induced conformational changes of antibodies (or haptens).
Structural implications of results from example antibody-hapten systems are
included. Fluorescence spectroscopy has been particularly useful in the area of
ligand binding, and thus steady-state fluorescence quenching and fluorescence
polarization are the primary techniques under discussion. A brief description of
fluorescence correlation spectroscopy is also provided. Absorption techniques,
including circular dichroism, are mentioned to a lesser extent. A basic
description of the mathematical models involved in the analysis of binding
equilibria is provided along with references to more complete works. Simulated
and experimental data are used to illustrate the various experimental protocols
and the appropriate analytical methods. Typical sources of errors and
experimental precautions are indicated throughout the general discussion.
PMID- 10694457
TI - Analysis of correlated motion in antibody combining sites from molecular dynamics
simulations.
AB - The crystal structures of the NC6.8-antisweet taste ligand complex and the
uncomplexed antibody structures display significant differences in the
conformations of residues in the combining site. A molecular dynamics method was
employed to understand the flexibility and correlated motion of key combining
site residues in the uncomplexed antibody. The simulations reveal that residues
that show conformational differences between the complex and uncomplexed
structures display strong dynamical correlations. Extensive analysis of the
dynamics trajectory using time correlation methods is presented.
PMID- 10694458
TI - Synthetic haptens as probes of antibody response and immunorecognition.
AB - The molecular forces that bind antibody to antigen have long fascinated chemists.
The use of synthetic haptens to study immunochemical phenomena can be traced back
to the classic work of Karl Lansteiner. His utilization of small-molecule-protein
conjugates first demonstrated the shape-selective nature of antibody binding.
Later work by Linus Pauling and David Pressman employed multivalent, synthetic
ligands to establish the bivalent nature of antibodies and explain the nature of
immunoprecipitation. Fluorescent probes such as dansyl, fluorescein, and
Ru(bpy)(2+)(3) have been used to study affinity maturation, quantify antibody
affinities, and investigate polyclonal antibody heterogeneity. Finally, X-ray
crystallography has yielded a molecular picture of how antibodies exercise
intermolecular forces (e.g., charge-charge interactions, H-bonding, and Van der
Waals) to bind haptens. Studies inspired by Landsteiner's original work continue
to play an important role in fields ranging from immunodiagnostics to catalytic
antibodies.
PMID- 10694459
TI - Neuromagnetic localization of CMV generators using incomplete and full-head
biomagnetometer.
AB - Contingent magnetic variation (CMV) data were recorded in three healthy male
subjects using a 2 x 37 biomagnetometer system. The experiment was repeated for
one of the subjects using a 151 whole-head biomagnetometer; the same auditory
GO/NOGO choice reaction time paradigm as in the first experiment was used,
extended to include repetitions of identical runs and additional control
conditions. Magnetic field tomography was applied to the averaged data of each
subject, for each run and condition (e.g., GO/NOGO). An independent estimate of
the current density in the brain was obtained every few milliseconds. The slow
components were emphasized by integrating the square of the current density
vector, pixel by pixel, revealing in each subject activity in the auditory
cortex, sensorimotor cortex, inferior prefrontal area, and posterior inferior
parietal area. The intersubject variability was large, but looking across
subjects the auditory and sensorimotor cortex (which were best covered by the two
probes) were consistently identified in each subject as contributing to the
generation of the early and late slow CMV components. These findings were
confirmed by the whole-head single-subject experiment, in which slow activity was
also identified in the supplementary motor area (SMA) and posterior cingulate
cortex (PCC), areas very likely missed in the first experiment because of the
limited view of the twin system. The PCC and particularly the SMA activations
were substantially reduced when identical runs were repeated.
PMID- 10694460
TI - The relationship between fMRI activation and cerebral atrophy: comparison of
normal aging and alzheimer disease.
AB - Functional MRI has recently been used to examine activation associated with aging
and dementia, yet little is known regarding the effect of cerebral atrophy on
fMRI signal. The purpose of this study was to examine the relationship between
measures of global and regionally specific atrophy and fMRI activation in normal
aging and in Alzheimer disease (AD). Two groups of subjects were studied with
echoplanar imaging and quantitative structural volumetry: healthy controls
spanning a broad age and atrophy range (n = 16) and patients with mild AD (n =
8). Results from a semantic task previously found to activate left inferior
frontal (LIFG) and left superior temporal (LSTG) gyri were analyzed. The
correlations between clusters of activation in the LIFG and LSTG and measures of
local atrophy in the LIFG and LSTG regions were evaluated. For control subjects,
there was no significant correlation between activation and regional or total
brain atrophy (for LIFG r = -0.03, NS; for LSTG r = 0.20, NS). In contrast, for
AD patients, there was a significant positive correlation between atrophy and
activation in LIFG (r = 0.70, P = 0.05) but not LSTG (r = 0.00, NS). These
results suggest that activation of language regions and atrophy within those
regions may be independent among healthy adults spanning a broad age and atrophy
range. However, in AD, a relationship exists in the LIFG that may reflect
compensatory recruitment of cortical units or disease-specific changes in the
hemodynamic response.
PMID- 10694461
TI - fMRI of the responses to vibratory stimulation of digit tips.
AB - Three studies were carried out to assess the applicability of fMRI at 3.0 T to
analysis of vibrotaction in humans. A novel piezoelectric device provided clean
sinusoidal stimulation at 80 Hz, which was initially applied in separate runs
within a scanning session to digits 2 and 5 of the left hand in eight subjects,
using a birdcage RF (volume) coil. Significant clusters of activation were found
in the primary somatosensory cortex (SI), the secondary somatosensory cortex
(SII), subcentral gyrus, the precentral gyrus, posterior insula, posterior
parietal regions (area 5), and the posterior cingulate. Digit separation in SI
was possible in all subjects and the activation sites reflected the known lateral
position of the representation of digit 2 relative to that of digit 5. A second
study carried out in six additional subjects using a surface coil, replicated the
main contralateral activation patterns detected in study one and further improved
the discrimination of the digits in SI. Significant digit separation was also
found in SII and in the posterior insula. A third study to investigate the
frequency dependence of the response focused on the effect of an increase in
vibrotactile frequency from 30 to 80 Hz, with both frequencies applied to digit 2
during the same scanning session in four new subjects. A significant increase in
the number of pixels activated within both SII and the posterior insula was
found, while the number of pixels activated in SI declined. No significant change
in signal intensity with frequencies was found in any of the activated areas.
PMID- 10694462
TI - Dissociable temporal lobe activations during emotional episodic memory retrieval.
AB - The richness of human recollective experience is, in part, related to evocation
of previously experienced emotions. An extensive functional neuroimaging
literature has provided a description of brain regions involved in retrieving
emotionally neutral episodic memories. Whether similar or distinct systems are
involved in retrieving emotional memories is unresolved. This question motivated
the present functional neuroimaging study, using 0-15 positron emission
tomography (PET), where we compared patterns of brain activation associated with
retrieving previously studied emotional and neutral pictorial material. By
varying task requirements and item density we characterized two distinct neural
response patterns during emotional memory retrieval. First, we identified an
anterior temporal pole activation that reflected the psychological set associated
with emotional memory retrieval. Second, we identified a left amygdala response
sensitive to actual retrieval of emotional items. These data suggest distinct
functional roles for temporal lobe regions during emotional memory retrieval
involving context-related tonic anterior temporal pole activation and a phasic
item-related amygdala response. We conclude that brain regions involved in
episodic memory retrieval reflect not only physical attributes of stimulus
material, for example, their verbal or visual qualities, but also their affective
significance.
PMID- 10694463
TI - Covert visual spatial orienting and saccades: overlapping neural systems.
AB - We used functional magnetic resonance imaging (fMRI) to investigate the
functional anatomical relationship between covert orienting of visual spatial
attention and execution of saccadic eye movements. Brain areas engaged by
shifting spatial attention covertly and by moving the eyes repetitively toward
visual targets were compared and contrasted directly within the same subjects.
The two tasks activated highly overlapping neural systems and showed that common
parietal and frontal regions are more activated during the covert task than the
overt oculomotor condition. The possible nature of the relationship between these
two operations is discussed.
PMID- 10694464
TI - The role of the right anterior prefrontal cortex in episodic retrieval.
AB - Regional brain activity was measured with H(2) (15)O PET while participants
attempted to complete word-stem and word-fragment retrieval cues with previously
studied words. The retrieval cue manipulation was employed to gain control over
the monitoring operations associated with evaluating the episodic status of
alternative cue completions. These operations were more constrained for
fragments, which had fewer possible completions than each corresponding stem. In
one condition (zero target), during the scanning interval none of the cues could
be completed with studied items, whereas in another condition (high target), 80%
of cues belonged to studied items. Relative to baseline tasks, right anterior
prefrontal activity was greater for stems than for fragments in the zero target
condition. The target density manipulation did not modulate right anterior
prefrontal activity, but was associated with increased activity in right
dorsolateral prefrontal cortex. These findings are consistent with the proposal
that the right anterior prefrontal cortex supports monitoring operations during
episodic retrieval tasks. In addition, the findings add to evidence suggesting
that the dorsolateral and anterior right prefrontal cortex make functionally
distinct contributions to episodic retrieval.
PMID- 10694465
TI - Functional localization of a "Time Keeper" function separate from attentional
resources and task strategy.
AB - The functional neuroanatomy of time estimation has not been well-documented. This
research investigated the fMRI measured brain response to an explicit,
prospective time interval production (TIP) task. The study tested for the
presence of brain activity reflecting a primary time keeper function, distinct
from the brain systems involved either in conscious strategies to monitor time or
attentional resource and other cognitive processes to accomplish the task. In the
TIP task participants were given a time interval and asked to indicate when it
elapsed. Two control tasks (counting forwards, backwards) were administered, in
addition to a dual task format of the TIP task. Whole brain images were collected
at 1.5 Tesla. Analyses (n = 6) yielded a statistical parametric map (SPM ?z?)
reflecting time keeping and not strategy (counting, number manipulation) or
attention resource utilization. Additional SPM ?z?s involving activation
associated with the accuracy and magnitude the of time estimation response are
presented. Results revealed lateral cerebellar and inferior temporal lobe
activation were associated with primary time keeping. Behavioral data provided
evidence that the procedures for the explicit time judgements did not occur
automatically and utilized controlled processes. Activation sites associated with
accuracy, magnitude, and the dual task provided indications of the other
structures involved in time estimation that implemented task components related
to controlled processing. The data are consistent with prior proposals that the
cerebellum is a repository of codes for time processing, but also implicate
temporal lobe structures for this type of time estimation task.
PMID- 10694466
TI - Time-dependent changes in learning audiovisual associations: a single-trial fMRI
study.
AB - Functional imaging studies of learning and memory have primarily focused on
stimulus material presented within a single modality (see review by Gabrieli,
1998, Annu. Rev. Psychol. 49: 87-115). In the present study we investigated
mechanisms for learning material presented in visual and auditory modalities,
using single-trial functional magnetic resonance imaging. We evaluated time
dependent learning effects under two conditions involving presentation of
consistent (repeatedly paired in the same combination) or inconsistent (items
presented randomly paired) pairs. We also evaluated time-dependent changes for
bimodal (auditory and visual) presentations relative to a condition in which
auditory stimuli were repeatedly presented alone. Using a time by condition
analysis to compare neural responses to consistent versus inconsistent
audiovisual pairs, we found significant time-dependent learning effects in medial
parietal and right dorsolateral prefrontal cortices. In contrast, time-dependent
effects were seen in left angular gyrus, bilateral anterior cingulate gyrus, and
occipital areas bilaterally. A comparison of paired (bimodal) versus unpaired
(unimodal) conditions was associated with time-dependent changes in posterior
hippocampal and superior frontal regions for both consistent and inconsistent
pairs. The results provide evidence that associative learning for stimuli
presented in different sensory modalities is supported by neural mechanisms
similar to those described for other kinds of memory processes. The involvement
of posterior hippocampus and superior frontal gyrus in bimodal learning for both
consistent and inconsistent pairs supports a putative function for these regions
in associative learning independent of sensory modality.
PMID- 10694467
TI - SAP family proteins.
AB - Thus far, five members including Dlg, SAP97/hDlg, SAP90/PSD-95, SAP102, and PSD
93/chapsyn110 which belong to SAP family have been identified. Recent studies
have revealed that these proteins play important roles in the localization and
function of glutamate receptors and K(+) channels. Although most of them have
been reported to be localized to the synapse, only one member, SAP97, is
expressed also in the epithelial cells. In this review, we have summarized
structural characters of SAP family proteins and discuss their functions in
neurons and epithelial cells.
PMID- 10694468
TI - Molecular and immunochemical evidences demonstrate that endooligopeptidase A is
the predominant cytosolic oligopeptidase of rabbit brain.
AB - Oligopeptidases are tissue endopeptidases that do not attack proteins and are
likely to be involved in the maturation and degradation of peptide hormones and
neuropeptides. The rabbit brain endooligopeptidase A and the rat testes soluble
metallopeptidase (EC 3.4.24.15) are thiol-activated oligopeptidases which are
able to generate enkephalin from a number of opioid peptides and to inactivate
bradykinin and neurotensin by hydrolyzing the same peptide bonds. A monospecific
antibody raised against the purified rabbit brain endooligopeptidase A allowed
the identification of a 2. 3 kb cDNA coding for a truncated enzyme of 512 amino
acids, displaying the same enzymatic features as endooligopeptidase A. In spite
of all efforts, employing several strategies, the full-length cDNA could not be
cloned until now. The analysis of the deduced amino acid sequence showed no
similarity to the rat testes metalloendopeptidase sequence, except for the
presence of the typical metalloprotease consensus sequence [HEXXH]. The antibody
raised against recombinant endooligopeptidase A specifically inhibited its own
activity and reduced the thiol-activated oligopeptidase activity of rabbit brain
cytosol to less than 30%. Analysis of the endooligopeptidase A tissue
distribution indicated that this enzyme is mainly expressed in the CNS, whereas
the soluble metallo EC 3.4.24.15 is mainly expressed in peripheral tissues.
PMID- 10694469
TI - Characterization of Pen n 13, a major allergen from the mold Penicillium notatum.
AB - Penicillium notatum is a well-known indoor aeroallergen and is frequently
included in skin test panels for allergic diagnosis. On two-dimensional
immunoblotting using patients' sera containing IgE and monoclonal antibody D7B8
specific for Pen c 1 of P. citrinum, two allergens with a molecular mass of 33
kDa but different isoelectric points were identified. A novel cDNA coding for Pen
n 13 was cloned and sequenced. The nucleotide sequence codes for a protein 397
amino acids including a putative signal peptide of 25 amino acids and a
propeptide of 90 amino acids. The allergen is an alkaline serine protease that
shares more than 39% identical residues with other kinds of mold allergens. The
coding cDNA of Pen n 13 was cloned into vector pQE-30 and expressed in E. coli
M15 as a His-tag fusion protein and purified to homogeneity. The fusion protein
reacted with monoclonal antibodies of Pen c 1 and with IgE from Penicillium
allergic patients. Furthermore, it also cross-reacted strongly with IgE specific
for the natural Pen c 1, indicating that similar IgE binding epitopes may exist
in the allergens of P. notatum and P. citrinum. Antigenicity index plots
indicated that there are several similar epitope regions of high antigenic
indices in Pen c 1 and Pen n 13, corroborating that mold allergens belonging to
the alkaline serine protease family possess similar protein structure and strong
antigenic cross-reactivity.
PMID- 10694470
TI - Markedly decreased binding of vincristine to tubulin in vinca alkaloid-resistant
Chinese hamster cells is associated with selective overexpression of alpha and
beta tubulin isoforms.
AB - Vinca alkaloids are among a number of cytotoxic agents which target tumor cell
microtubules. Studies described herein document the basis for one form of
acquired resistance to these plant alkaloids involving an alteration of tubulin
in a variant (DC-3F/VCRd-5L) of DC-3F Chinese hamster cells. Our results revealed
a markedly decreased binding of [(3)H]vincristine (VCR) to tubulin extracted from
this variant compared to tubulin extracted from wild-type DC-3F cells. This was
quantitated as a 10- to 15-fold decrease in on-rate in the presence of GTP for
the [(3)H]VCR associating with tubulin in cell-free cytosol and a 10-fold
increase in off-rate for GTP-dependent dissociation of the [(3)H]VCR-tubulin
complex. Quantitative RT-PCR and nucleotide sequencing of poly(A)(+) RNA also
carried out with variant and wild-type DC-3F cells documented a different pattern
of relative expression, but no base pair differences in the open reading frame of
the three alpha and beta tubulin isoforms detected in each cell type. This was
accounted for by selective overexpression of one alpha tubulin (alphaII) and two
beta tubulin (betaI and betaIV) isoforms in the variant cells. These results
would appear to provide an underlying basis for the large decrease in [(3)H]VCR
binding by tubulin in these variant Chinese hamster cells and a major component
of their acquired resistance to this vinca alkaloid.
PMID- 10694471
TI - Digital fluorescence imaging of trafficking of endosomes containing low-density
lipoprotein in brain astroglial cells.
AB - We have used digital fluorescence microscopy to examine transport of LDL
containing endosomes in rat brain astroglial cells to show that individual middle
endosomes undergo rapid transitions between forward/backward movements and
immobile states over short distances. The population of rapidly moving endosomes
(>0.04 microm/sec) was 35. 9%, and the remaining endosomes were slowly moving or
temporarily immobile (<0.04 microm/sec). The averaged motion was, however, a very
slow perinuclear motion with a velocity of 3.25 microm/h. This small velocity is
mainly due to frequent changing of directions in movements, requiring 6 h for a
significant concentration around the circumference of the cell nuclei. The
application of both anti-dynein antibodies and vanadate in permeabilized cells
resulted in peripherally concentrated distribution of endosomes, probably due to
inhibition of perinuclear motion by dynein-like motor proteins. These results
imply that both dynein-like and kinesin-like proteins bind to the same endosome
resulting in both perinuclear and peripherally directed movements.
PMID- 10694472
TI - Activation of the human p27(Kip1) promoter by IFNalpha 2b.
AB - p27(Kip1) is one of the key regulatory proteins in cell cycle through inhibition
of pRB phosphorylation by suppression of the activity of several cyclin/Cdk
complexes. The expression of p27(Kip1) has been shown to be controlled by a
posttranslational mechanism, although vitamin D(3) and neuronal differentiation
can also induce its mRNA. Recently, the p27(Kip1) promoter was isolated and
sequenced from a human leukocyte genomic library. In this report, we demonstrate
that IFNalpha 2b, activates the human p27(Kip1) promoter-driven luciferase
reporter gene in transient expression assays in H82 cells. This induction might
involve two IRF 1-like binding sites present in the p27(Kip1) promoter. To our
knowledge this is the first report on the direct activation of the human
p27(Kip1) promoter by IFNalpha 2b.
PMID- 10694473
TI - BanI restriction endonuclease binds in the major groove of DNA: an inhibition
kinetic study using substrates with mismatch basepairs.
AB - Structural information on BanI-DNA interaction was obtained from simple
inhibition kinetic assays using altered substrates. Self-complementary 13-mer
oligodeoxynucleotides with or without mismatch basepairs in the BanI recognition
sequence (GGPyPuCC) were synthesized. UV melting curves and CD spectra indicated
double-stranded B-DNA structure for all the oligomers. Among the seven oligomers
with recognition sequences, GGTACC, GGTGCC, GGTATC, GGCACC, GGAGCC, GGTAAC, and
GGATCC, only the first two were cleaved with BanI. Kinetics of BanI cleavage of
the native substrate was inhibited competitively by all of the other oligomers
except the one with sequence GGCACC. From inhibition kinetic analysis in presence
of a fixed concentration of the inhibitor, apparent K(m) and K(I) were
determined. The data were analyzed in the context of alterations made in the
hydrogen bonding potential in the major and minor groove of DNA within the
recognition sequence due to basepair mismatches. Such analyses led to the
conclusion that BanI, like BamHI, binds in the major groove and the central
thymines make important contact with the protein.
PMID- 10694474
TI - Leptin regulation of prepro-orexin and orexin receptor mRNA levels in the
hypothalamus.
AB - The aim of this study was to determine the effects of leptin treatment on prepro
orexin and orexin receptor expression in the rat hypothalamus. Adult male rats,
food-deprived for 48 and 72 h, were treated one time with vehicle or leptin (10
microg, icv). Prepro-orexin mRNA content was measured by semiquantitative RT-PCR,
Northern blot, and in situ hybridization; orexin receptor 1 and 2 mRNA content
was quantified by Northern blot and/or semiquantitative RT-PCR. Our results
indicate that leptin inhibits a fasting-induced increase in prepro-orexin mRNA
and orexin receptor 1 mRNA levels in the rat hypothalamus, while orexin receptor
2 mRNA levels were unchanged in all situations evaluated. These data provide
direct evidence for an additional mechanism of adaptation of the hypothalamus to
food deprivation and for a new effect of leptin in the regulation of food intake.
PMID- 10694475
TI - Serum-free, long-term cultures of human hepatocytes: maintenance of cell
morphology, transcription factors, and liver-specific functions.
AB - Since human hepatocytes are available only in limited number, the development of
a serum-free culture system for long-term cultivation of differentiated and
functional hepatocytes is of great importance. Here we describe the culture of
human hepatocytes in a chemically defined serum-free medium for up to 5 weeks.
Cell morphology was assayed by light and electron microscopy and revealed a well
preserved cellular morphology. Marker proteins for epithelial and bile duct
cells, cytokeratin (CK) 18 and 19, and liver-specific proteins, like
phosphoenolpyruvate carboxykinase-2 (PCK2) and serum proteins, were expressed.
Liver-enriched transcription factors CCAAT/enhancer binding protein alpha
(C/EBPalpha) and hepatocyte nuclear factor-4 (HNF-4), cytokine and mitogen
activated factors (nuclear factor kappa B) NFkappaB, and activator protein-1 (AP
1) were maintained and active for several weeks in our cultures. In summary, our
serum-free culture system allows the culture of differentiated human hepatocytes
for several weeks. It may serve as a model system for metabolic, pharmacologic
toxicologic studies, and studies on human pathogens under defined chemical
conditions.
PMID- 10694476
TI - Cloning and characterization of the human retinoid X receptor alpha gene:
conservation of structure with the mouse homolog.
AB - Retinoid X receptors (RXRs) are members of the steroid/thyroid hormone receptor
superfamily which, along with retinoic acid receptors (RARs), mediate the
biological effects of retinoids. These effects include the regulation of many
aspects of embryonic development, reproductive and visual function, and the
maintenance of epithelial homeostasis throughout life. The genes for three
distinct retinoid X receptors, RXRalpha, beta, and gamma, have been localized to
separate chromosomes. In order to determine the organization of the human
RXRalpha gene, we have isolated a clone containing the majority of the gene from
a human genomic bacterial artificial chromosome (BAC) library and generated a
physical map. The gene spans over 40 kilobases in size and contains at least 10
exons. Comparison with mapped portions of the mouse RXRalpha gene indicates
highly conserved intron-exon positioning. These results provide information
necessary to generate constructs for targeting the RXRalpha gene in human cell
lines, which may eventually lead to an understanding of the function of RXRalpha
in human cancer.
PMID- 10694477
TI - Engineering His(E7) affects the control of heme reactivity in Aplysia limacina
myoglobin.
AB - Aplysia limacina myoglobin lacks the distal histidine (His (E7)) and displays a
ligand stabilization mechanism based on Arg(E10). The double mutant Val(E7)His
Arg(E10)Thr has been prepared to engineer the role of His(E7), typical of
mammalian myoglobins, in a different globin framework. The 2.0 A crystal
structure of Val(E7)His-Arg(E10)Thr met-Mb mutant reveals that the His(E7) side
chain points out of the distal pocket, providing an explanation for the observed
failure to stabilize the Fe(II) bound oxygen in the ferrous myoglobin. Moreover,
spectroscopic analysis together with kinetic data on azide binding to met
myoglobin are reported and discussed in terms of the presence of a water molecule
at coordination distance from the heme iron.
PMID- 10694478
TI - Characterization of mutations induced by ethyl methanesulfonate, UV, and
trimethylpsoralen in the nematode Caenorhabditis elegans.
AB - The genome project of the nematode Caenorhabditis elegans is completed. It is
important and useful to disrupt nematode genes to know their function. We treated
wild-type animals with potential candidates for mutagens for reverse genetics,
EMS (ethyl methanesulfonate), short-wavelength UV, and long-wavelength UV in the
presence of TMP (trimethylpsoralen). We estimated forward mutation rates by
counting the occurrence of a marker unc-22 mutation. We found that the forward
mutation rate by TMP/UV could be comparable with EMS by improving the frequency
one order higher than before. We next isolated mutants of another marker gene ben
1 and examined the probability for the deletion mutations by PCR and sequencing.
Deletion mutations were found only by TMP/UV method, which suggested TMP/UV is
the choice for deletion mutagenesis among these methods. As a pilot experiment,
we could isolate actual deletion mutations at a much higher frequency than
previously.
PMID- 10694479
TI - Regulation of rheumatoid synovial cell growth by ceramide.
AB - Overgrowth of rheumatoid synoviocytes, which results in joint destruction, is due
to impaired balance between cell proliferation and cell death (apoptosis).
Ceramide is an important lipid messenger involved in mediating a variety of cell
functions including apoptosis. We investigated the effects of ceramide on growth
promoting anti-apoptotic signals in rheumatoid synovial cells. Human synovial
cells isolated from patients with rheumatoid arthritis (RA) were stimulated with
platelet-derived growth factor (PDGF) in the presence or absence of C2-ceramide.
The kinase activity of Akt, MEK, and ERK1/2 was analyzed in PDGF-stimulated
synovial cells by Western blot analysis. Pretreatment with C2-ceramide completely
inhibited PDGF-induced cell cycle progression of rheumatoid synovial cells. PDGF
stimulation induced phosphorylation and activation of Akt, MEK, and ERK1/2 in
rheumatoid synovial cells. C2-ceramide inhibited the activation of Akt, MEK and
ERK1/2 in PDGF-stimulated synovial cells. Our data demonstrated that inhibition
of anti-apoptotic kinases, such as Akt and ERK1/2, may play an important role in
ceramide-mediated apoptosis of rheumatoid synovial cells.
PMID- 10694480
TI - Assignment of overlapping (1)H NMR signals in carp seminal plasma by proton
detected 2D C,H correlation spectroscopy.
AB - The (1)H NMR spectrum of the perchloric acid extract of carp seminal plasma was
heavily congested. It is demonstrated that proton-detected C,H chemical shift
correlation spectroscopy (HSQC, HSQC-TOCSY) allows an unequivocal identification
of proline, glutamate, taurine, and methionine sulfoxide, although several key
proton signals were strongly overlapped.
PMID- 10694481
TI - Design, chemical synthesis and kinetic studies of trypsin chromogenic substrates
based on the proteinase binding loop of Cucurbita maxima trypsin inhibitor (CMTI
III).
AB - A series of trypsin chromogenic substrates with formula: Y-Ala-X-Abu-Pro-Lys-pNA,
where X = Gly, Ala, Abu, Val, Leu, Phe, Ser, Glu and Y = Ac, H; pNA = p
nitroanilide was synthesized. The Cucurbita maxima trypsin inhibitor CMTI-III
molecule was used as a vehicle to design the trypsin substrates. To evaluate the
influence of position P(4) on the substrate-enzyme interaction, kinetic
parameters of newly synthesized substrates with bovine beta-trypsin were
determined. The increasing hydrophobicity of the amino acid residue (Gly, Ala,
Abu, Val) introduced in position P(4) significantly enhanced the substrate
specificity (k(cat)/K(m)) which was over 8 times higher for the last residue than
that for the first one. The introduction of residues with more hydrophilic side
chain (Glu, Ser) in this position reduced the value of this parameter. These
results correspond well with those obtained using molecular dynamics of bovine
beta-trypsin with monosubstituted CMTI-I analogues, indicating that in both
trypsin substrate and inhibitor position 4 plays an important role in the
interaction with the enzyme.
PMID- 10694482
TI - Flow cytometric parameters for characterizing platelet activation by measuring P
selectin (CD62) expression: theoretical consideration and evaluation in thrombin
treated platelet populations.
AB - Two flow cytometric parameters are generally used to quantify platelet activation
as measured by P-selectin (CD62) expression: percentage and mean channel
fluorescence of CD62-positive platelets (%(+) and MCF(+), respectively). We
describe a method for calculation of indices of platelet activation for positive
(IPA(+)) and total (IPA(Sigma)) platelets, which reflect integrated amounts of
CD62 expressed in these populations; IPA(+) is calculated as the product of %(+)
and MCF(+), whereas IPA(Sigma) is exclusively determined by mean fluorescence of
the total platelet population (MCF(Sigma)) and does not depend on %(+). We use
these parameters to characterize human platelet activation in whole blood samples
treated with varying human alpha-thrombin concentrations, mimicking the
variations in platelet activation in a number of clinical settings.
Multiparameter analysis of CD62 expression may be useful for selective diagnosis
of disorders with systemic or localized platelet activation and for monitoring
the clinical course of the disease and effect of therapeutic interventions.
PMID- 10694483
TI - Molecular cloning and genomic organization of a novel receptor from Drosophila
melanogaster structurally related to mammalian galanin receptors.
AB - We screened the Berkeley "Drosophila Genome Project" database with "electronic
probes" corresponding to conserved amino acid sequences from the five known rat
somatostatin receptors. This yielded alignment with a Drosophila genomic clone
that contained a DNA sequence coding for a protein, having amino acid sequence
identities with the rat galanin receptors. Using PCR with Drosophila cDNA as a
template, and oligonucleotide probes coding for the exons of the presumed
Drosophila gene, we were able to clone the cDNA for this receptor. The Drosophila
receptor has most amino acid sequence identity with the three mammalian galanin
receptors (37% identity with the rat galanin receptor type-1, 32% identity with
type-2, and 29% identity with type-3). Less sequence identity exists with the
mammalian opioid/nociceptin-orphanin FQ receptors (26% identity with the rat
micro opioid receptor), and mammalian somatostatin receptors (25% identity with
the rat somatostatin receptor type-2). The novel Drosophila receptor gene
contains ten introns and eleven exons and is located at the distal end of the X
chromosome.
PMID- 10694484
TI - Cerivastatin suppresses lipopolysaccharide-induced ICAM-1 expression through
inhibition of Rho GTPase in BAEC.
AB - We investigated the effect of cerivastatin on lipopolysaccharide (LPS)-induced
intercellular adhesion molecule-1 (ICAM-1) expression in bovine aortic
endothelial cells. Cerivastatin suppressed LPS-induced ICAM-1 mRNA expression.
Cotreatment with geranylgeranylpyrophosphate reversed the effect of cerivastatin.
Because Rho undergoes geranylgeranyl modification, we elucidated whether Rho is
involved in LPS-induced ICAM-1 expression. Inhibition of Rho activity by
Clostridium botulinum C3 transferase or by overexpression of RhoA T19N, a
dominant-negative mutant of RhoA, decreased LPS-induced ICAM-1 expression.
Although cerivastatin up-regulated endothelial nitric oxide synthase (eNOS),
inhibition of nitric oxide (NO) synthesis by cotreatment with N(omega)-nitro-l
arginine methyl ester (L-NAME) exhibited no influence on the effect of
cerivastatin. The present results indicate that cerivastatin prevents LPS-induced
ICAM-1 expression in endothelial cells via inhibition of Rho activity. This
inhibitory effect is likely unrelated to up-regulation of eNOS.
PMID- 10694485
TI - Molecular cloning and genomic structure of the betaTRCP2 gene on chromosome
5q35.1.
AB - Beta-catenin, IkappaBalpha, and HIV Vpu are recruited to the ubiquitin-proteasome
degradation pathway by betaTRCP, one of the components of the ubiquitin ligase
complex. betaTRCP2, a related gene of betaTRCP, was cloned and characterized.
Three isoforms, betaTRCP2A, betaTRCP2B, and betaTRCP2C, were identified. All of
these betaTRCP2 isoforms consist of an F-box and seven WD repeats. Human
betaTRCP2A shows 86% total amino acid identity with human betaTRCP. betaTRCP2
mRNA of 4.5 kb in size was detected almost ubiquitously. Sequence analyses on
betaTRCP2 genomic clones revealed that the betaTRCP2 gene consists of at least 14
exons. Exons 1 and 4-14 are shared among all betaTRCP2 isoforms. betaTRCP2A of
508 amino acids lacks exons 2 and 3, betaTRCP2B of 529 amino acids contains exon
3, and betaTRCP2C of 542 amino acids contains exon 2. These results indicate that
three betaTRCP2 isoforms are transcribed due to alternative splicing. The
betaTRCP2 gene has been mapped to human chromosome 5q35.1 by fluorescence in situ
hybridization.
PMID- 10694486
TI - Comprehensive gene expression profile of a normal human liver.
AB - To investigate the gene expression profile of a normal human liver, we performed
serial analysis of gene expression (SAGE), which allows the quantitative and
simultaneous analysis of thousands of genes expressed in tissue. Polyadenylated
RNA was obtained from a bulk normal human liver sample and SAGE was performed.
Reverse transcriptase-polymerase chain reaction (RT-PCR) was also performed in
each of 3 different normal liver samples to evaluate the validity of the profile
in each individual. A total of 30,982 tags were sequenced, 8,596 of which were
unique. The genes highly expressed in the normal liver were those encoding plasma
proteins (>21.8% of total transcripts), cytoplasmic proteins (>8.6%), enzymes
(>4.8%), protease inhibitors (>1.7%), complements (>1.1%), and coagulation
factors (>0.75%). About 13.9% of all transcripts encoded genes not reported in
GenBank thus far. This study identifies candidate genes to be examined in
relation to various human liver diseases, including viral hepatitis, liver
cirrhosis, and hepatocellular carcinoma.
PMID- 10694487
TI - Chemotaxis of a Ralstonia sp. SJ98 toward different nitroaromatic compounds and
their degradation.
AB - A Ralstonia sp. SJ98, isolated by a chemotactic enrichment technique, was capable
of utilizing different nitroaromatic compounds (NACs). It utilized p-nitrophenol,
4-nitrocatechol, o-nitrobenzoic acid, and p-nitrobenzoic acid as the sole source
of carbon and energy. It was observed that Ralstonia sp. SJ98 was chemotactic to
the above-mentioned NACs as tested by the drop assay, swarm plate assay, and
capillary assay. However, it failed to show chemotactic behavior toward those
compounds which were not degraded by the microorganism. This is the first report
which shows the chemotaxis of a microorganism toward different NACs and their
subsequent degradation. Some of the intermediates of the NACs' degradative
pathways have been identified using TLC, GC, and GC-MS studies. The results
presented here indicate a correlation between chemotaxis and biodegradation of
NACs.
PMID- 10694488
TI - Structural basis for SH2D1A mutations in X-linked lymphoproliferative disease.
AB - X-linked lymphoproliferative disease (XLP) is a rare and severe immune
deficiency, characterized by abnormal immune responses to the Epstein-Barr virus.
Recently, the gene responsible for XLP, SH2D1A, has been identified and shown to
code for a small cytoplasmic protein with an SH2 domain that interacts with SLAM
and 2B4, two receptorial molecules involved in signal transduction in T and NK
cells, respectively. A variety of SH2D1A gene mutations have been reported thus
far in XLP males. Here we describe a single-strand conformation polymorphism
assay for mutation analysis in XLP. Four novel patients with SH2D1A mutations are
described. These mutants, and the others previously reported in the literature,
have been included in a Registry (SH2D1Abase) that is fully accessible on the
World Wide Web. A three-dimensional model of the SH2 domain of the SH2D1A protein
has been developed, based on homology with other SH2 domains. The structural
consequences of disease-causing SH2D1A mutations are discussed.
PMID- 10694489
TI - Chemiluminescent detection and imaging of reactive oxygen species in live mouse
skin exposed to UVA.
AB - The recent increase of ultraviolet (UV) rays on Earth due to the increasing size
of the ozone hole is suggested to be harmful to life and to accelerate premature
photoaging of the skin. The detrimental effects of UV radiation on the skin are
associated with the generation of reactive oxygen species (ROS) such as
superoxide anion radical (*O(-)(2)), hydrogen peroxide (H(2)O(2)), hydroxyl
radical (*OH), and singlet oxygen ((1)O(2)). However, direct proof of such ROS
produced in the skin under UV irradiation has been elusive. In this study, we
report first in vivo detection and imaging of the generated ROS in the skin of
live mice following UVA irradiation, in which both a sensitive and specific
chemiluminescence probe (CLA) and an ultralow-light-imaging apparatus with a CCD
camera were used. In addition, we found that *O(-)(2) is formed spontaneously and
(1)O(2) is generated in the UVA-irradiated skin. This method should be useful not
only for noninvasive investigation of the spatial distribution and quantitative
determination of ROS in the skin of live animals, but also for in vivo evaluation
of the protective ability of free radical scavengers and antioxidants.
PMID- 10694490
TI - Translocation of HSP27 to sarcomere induced by ischemic preconditioning in
isolated rat hearts.
AB - We investigated the role of the 27-kDa heat shock protein (HSP27) in cardiac
protection using Langendorff-perfused rat hearts. After preconditioning (a single
episode of 5 min global ischemia followed by 5 min of reperfusion), HSP27
redistributed from the cytosol to the sarcomere and recovery of the contractile
function, after 40 min of global ischemia and 50 min of reperfusion, was
significantly enhanced. Both SB203580, a p38 MAP kinase inhibitor, and
bisindolylmaleimide I, a protein kinase C inhibitor, prevented the effects of
preconditioning. Both 2-chloro-N(6)-cyclopentyladenosine (adenosine A1 agonist)
and anisomycin (activator of p38 MAP kinase and c-jun N-terminal kinase) mimicked
preconditioning. These results suggest that activation of protein kinase C
followed by activation of p38 MAP kinase elicits translocation of HSP27 to the
sarcomere, a process which may be involved in the cardioprotective mechanism
afforded by ischemic preconditioning in rat heart.
PMID- 10694491
TI - Aminopeptidase N/CD13 is associated with raft membrane microdomains in monocytes.
AB - Ectopeptidases play important roles in cell activation, proliferation, and
communication. Human monocytic cells express considerable amounts of
aminopeptidase N/CD13, a transmembrane protein previously proposed to play a role
in the regulation of neuropeptides and chemotactic mediators as well as in
adhesion and cell-cell interactions. Here, we report for the first time that
aminopeptidase N/CD13 in monocytes is partially localized in detergent-insoluble
membrane microdomains enriched in cholesterol, glycolipids, and
glycosylphosphoinositol-anchored proteins, referred to as "rafts." Raft fractions
of monocytes were characterized by the presence of GM1 ganglioside as raft marker
molecule and by the high level of tyrosine-phosphorylated proteins. Furthermore,
similar to polarized cells, rafts in monocytic cells lack Na(+), K(+)-ATPase.
Cholesterol depletion of monocytes by methyl-beta-cyclodextrin greatly reduces
raft localization of aminopeptidase N/CD13 without affecting ala-p-nitroanilide
cleaving activity of cells.
PMID- 10694492
TI - Cre-mediated cerebellum- and hippocampus-restricted gene mutation in mouse brain.
AB - Using the phage P1-derived Cre/loxP recombination system, we have created a line
of cre-transgenic mice in which the Cre-mediated gene deletion is restricted to
granule cells of cerebellum and dentate gyrus of hippocampus. Low levels of
deletion were also present in pyramidal cells of hippocampal CA1 and CA3 fields.
The Cre/loxP recombination occurred prenatally. The recombination efficiencies in
the granular layer of the cerebellum, the granular layer of the dentate gyrus,
and the CA1 and CA3 pyramidal cells of the hippocampus were 34.0%, 23.1%, 3.0%,
and 9.8%, respectively. This line of cre-transgenic mice should be conducive to
studies of the effect of a gene mutation upon brain development and plasticity.
PMID- 10694493
TI - Dolichin, a new chitinase-like antifungal protein isolated from field beans
(Dolichos lablab).
AB - An antifungal protein, possessing a molecular weight of 28 kDa and an N-terminal
sequence resembling chitinases, has been purified from the seeds of the field
bean Dolichos lablab. The procedure involved extraction with aqueous buffer,
affinity chromatography on Affi-gel blue gel, and ion exchange chromatography on
CM-Sepharose. The protein, designated dolichin, exhibited antifungal activity
against the fungi Fusarium oxysporum, Rhizoctonia solani, and Coprinus comatus.
Dolichin was capable of inhibiting human immunodeficiency virus (HIV) reverse
transcriptase and alpha- and beta-glucosidases which are glycohydrolases
implicated in HIV infection. It had very low ribonuclease and cell-free
translation-inhibitory activities.
PMID- 10694494
TI - Attenuated nitric oxide synthase activity and protein expression accompany
intestinal ischemia/reperfusion injury in rats.
AB - Intestinal ischemia/reperfusion (I/R) leads to bowel impairment via the release
of reactive oxygen species (ROS) and neutrophil infiltration. In addition to
modulating intestinal integrity, nitric oxide (NO(*)) inhibits neutrophil
activation and scavenges ROS. Attenuated endogenous NO(*) formation may result in
the accrual of these deleterious stimuli. Therefore, we determined nitric oxide
synthase (NOS) activity in anesthetized rats subjected to 1 h of superior
mesenteric ischemia or ischemia followed by reflow. NOS activity was measured in
intestinal tissue homogenates as the conversion rate of (3)H-L-arginine to (3)H-L
citrulline. Our results demonstrate that intestinal ischemia leads to a decrease
in NOS activity indicating lower NO(*) formation in the animal model. The
attenuation in NOS activity was not reversed following 4 h of reperfusion.
Western blot analysis revealed that the decline in enzyme activity was
accompanied by reduced intestinal NOS III (endothelial constitutive NOS)
expression. These findings provide biochemical evidence for impaired NO(*)
formation machinery in intestinal I/R injury.
PMID- 10694495
TI - Nitric-oxide-dependent pial arteriolar dilation in the female rat: effects of
chronic estrogen depletion and repletion.
AB - In this study, we compared endothelial nitric oxide synthase (eNOS)-mediated
cerebral vasodilating responses in intact female rats, chronically ovariectomized
(OVX) rats, and OVX rats treated for 2 weeks with 17beta-estradiol (E(2)). Under
anesthesia, using intravital microscopy and a closed cranial window system, pial
arteriolar diameter changes were monitored during sequential cortical suffusions
of an eNOS-dependent dilator [acetylcholine (ACh)] and a direct NO donor [S
nitrosoacetylpenicillamine (SNAP)]. In separate rats from the same groups, we
compared eNOS and caveolin-1 (CAV-1) protein abundance in pial arterioles (via
immunofluorescence analyses). In untreated and low-dose E(2)-treated (1.0 microg
x kg(-1) x day(-1)) OVX rats, ACh-induced vasodilations were virtually absent.
High-dose E(2) treatment (100 microg x kg(-1) x day(-1)) restored ACh-induced
pial arteriolar dilations to levels seen in intact females. The vasodilations
elicited by SNAP and ADO were unaffected by chronic estrogen changes, indicating
no direct estrogen influence on vascular smooth muscle (VSM) reactivity. Pial
arteriolar eNOS protein abundance was diminished by ovariectomy and restored by
high-dose E(2) treatment. Pial arteriolar CAV-1 expression was higher in OVX
versus intact and E(2)-treated OVX females. These results suggest that long-term
changes in estrogen directly influence brain eNOS functional activity. The
estrogen-related changes in eNOS-dependent vasodilating function appear to be
related, in part, to a capacity for E(2) to increase eNOS protein expression and,
in part, to an E(2)-associated diminution in endothelial CAV-1 expression.
PMID- 10694496
TI - Microvascular pericytes express aggrecan message which is regulated by BMP-2.
AB - Multipotential mesenchymal stem cells capable of chondro-osseous induction
contribute to the endochondral callus of healing fractured bone. Microvascular
pericytes serving the role of multipotential mesenchymal stem cells are
considered osteoprogenitors because they express type I collagen, alkaline
phosphatase enzyme activity, osteocalcin immunoreactivity, and bone sialoprotein
mRNA. Previous electron microscopic studies indicate that this cell type has a
contribution to the fracture callus. Limited data suggest that pericytes may also
assume a chondrogenic phenotype. We undertook in vitro studies to understand how
the chondro-osseous phenotype of the pericyte might be regulated. Using Northern
analysis and semiquantitative reverse transcriptase-polymerase chain reaction (RT
PCR), we found that cultured pericytes produce aggrecan and type II collagen mRNA
indicating their chondrogenic potential. Aggrecan message is elevated by BMP-2 as
analyzed by both Northern hybridization and RT-PCR. This finding suggests a
regulatory role for this morphogen on this phenotype in pericytes. RT-PCR
amplified versican product was also associated with pericyte cultures but was not
affected by BMP-2. Our data strongly support a chondrogenic role for the pericyte
and that the phenotype is regulated at least in part by BMP.
PMID- 10694497
TI - p21(WAF1/CIP1) inhibits initiator caspase cleavage by TRAIL death receptor DR4.
AB - Death receptors of the Tumor Necrosis Factor (TNF) family form membrane-bound
self-activating signaling complexes that initiate apoptosis through cleavage of
proximal caspases including CASP8 and 10. Here we show that overexpression of the
cytoplasmic domain (CD) of the DR4 TRAIL receptor (TNFRSF10A, TRAIL R1) in human
breast, lung, and colon cancer cell lines, using an adenovirus vector (Ad-DR4
CD), leads to p53-independent apoptotic cell death involving cleavage of CASP8
and 10 proximally and CASP3, 6, and 7 distally. DR4-CD overexpression also leads
to cleavage of poly(ADP-ribose) polymerase (PARP) and the DNA fragmentation
factor (DFF45; ICAD). Importantly, normal lung fibroblasts are resistant to DR4
CD overexpression and show no evidence of PARP-, CASP8- or CASP3-cleavage despite
similar levels of adenovirus-delivered DR4-CD protein as the cancer cells. These
results suggest that DR4 may signal death through known caspases and that further
studies are required to evaluate Ad-DR4-CD as a novel anti-cancer agent. Finally,
we show that overexpression of the cyclin-dependent kinase inhibitor
p21(WAF1/CIP1) (CDKN1A), or its N-terminal 91 amino acids containing cell cycle
inhibitory activity, inhibits DR4-CD-dependent proximal caspase cleavage. The
blockage of initiator caspase activation provides a novel insight into how p21
may suppress apoptosis and enhance cell survival.
PMID- 10694498
TI - Localization of HSP90 binding sites in the human hepatitis B virus polymerase.
AB - The fact that HSP90 proteins and their chaperonin partners play an important role
in epsilon RNA binding of duck HBV Pol protein during duck HBV replication has
been reported. To elucidate the molecular basis of HBV Pol/HSP90 interaction, we
have characterized the HSP90 interaction to HBV Pol. We found that human HBV Pol
protein upon synthesis in rabbit reticulocyte lysate formed a complex with HSP90
in vitro as duck HBV Pol did. In addition, HSP90 protein was copurified with
MBP/POL protein expressed in HepG2 cells, suggesting that human HBV Pol protein
is associated with HSP90 in vivo. To localize the HSP90 interaction site region,
several deletion mutants of HBV Pol translated in vitro were immunoprecipitated
with anti-HSP90 antibody. The result indicates that C-terminal regions of the TP
and RT domains interact with HSP90 independently.
PMID- 10694499
TI - Identification of a novel retinoic acid-responsive element within the lamin A/C
promoter.
AB - A-type lamins are not present in either early embryos or the embryonal carcinoma
(EC) cell line. P19 cells, which are EC cell line, are able to express A-type
lamins upon retinoic acid (RA) treatment. Here we report that a novel RA
responsive element, termed lamin A/C-RA-responsive element (L-RARE), is located
within the lamin A/C promoter. RA activated the luciferase activity of the
reporter which had four tandem repeats of the wild-type L-RARE, while a loss of
function mutant, which altered CACCCCC to CACtatC within L-RARE, did not respond.
Four specific binding complexes of L-RARE, Complexes-A, -B, -C, and -D, were
detected in protein extracts obtained from P19 cells treated with and without RA.
Specific antibodies revealed that Sp1 and Sp3 were included in Complex-A and
Complexes-B and -C, respectively. Thus, L-RARE was important in the RA-mediated
activation of the lamin A/C promoter and was recognized by DNA binding proteins.
PMID- 10694500
TI - Quinqueginsin, a novel protein with anti-human immunodeficiency virus,
antifungal, ribonuclease and cell-free translation-inhibitory activities from
American ginseng roots.
AB - A homodimeric protein designated quinqueginsin, with a molecular weight of 53
kDa, has been isolated from the roots of American ginseng Panax quinquefolium. It
was unadsorbed on DEAE cellulose in low ionic strength and neutral pH, and
adsorbed on Affigel blue gel and SP-Sepharose under similar conditions. Its N
terminal sequence bore similarity to those of plant ribosome inactivating
proteins and fungal ribonucleases. The protein displayed a variety of biological
activities. It possessed ribonucleolytic activity toward yeast tRNA and specific
activity toward poly C. It inhibited cell-free translation in a rabbit
reticulocyte lysate system with an IC(50) of 0.26 nM, and exerted antifungal
action against Fusarium oxysporum, Rhizoctonia solani, and Coprinus comatus. An
inhibitory action was expressed toward human immunodeficiency virus-1 reverse
transcriptase. This action was potentiated after chemical modification with
succinic anhydride.
PMID- 10694501
TI - Progestins and androgens increase expression of Spot 14 in T47-D breast tumor
cells.
AB - Enhanced expression of fatty acid synthase and other lipogenic enzymes has been
observed in a subset of breast cancers with poor prognosis. This phenomenon has
been related to amplification of a gene on chromosome region 11q13 encoding Spot
14, a putative regulator of lipogenic enzyme expression. In this paper we
demonstrate that the induction of lipogenesis by progestins and androgens in the
breast cancer cell line T47-D is accompanied by a marked increase in the
expression of Spot 14. These data corroborate the correlation between Spot 14
expression and increased lipogenesis. Moreover they show that apart from gene
amplification there is another steroid-regulated pathway that may enhance Spot 14
expression and lipogenesis in tumor cells.
PMID- 10694502
TI - Molecular mechanism of the nacreous layer formation in Pinctada maxima.
AB - We have cloned the cDNAs that encode two kinds of molluscan shell matrix
proteins, namely N66 and N14, in the nacreous layer of Pinctada maxima. N66 is
composed of carbonic anhydrase-like and repeat domains, as described for nacrein
(1) in the pearls of P. fucata. N14 is homologous to N16, recently found in the
nacreous layer of P. fucata (2) and is characterized by high proportions of Gly,
Tyr, and Asn together with NG repeat sequences. The molecular weights of these
proteins were estimated as 59,814 and 13,734 Da, respectively. Structural
differences were clearly indicated in the alignment and length of the repeat
sequences of the sets of the homogeneous proteins (N66/nacrein and N14/N16). The
longer repeat sequences of N66 and N14 may be responsible for P. maxima's
excellent property of calcification. The in vitro crystallization experiments
revealed that the mixture of N66 and N14 could induce platy aragonite layers
highly similar to the nacreous layer, once adsorbed onto the membrane of the
water-insoluble matrix.
PMID- 10694503
TI - Suppressive effects of swainsonine and N-butyldeoxynojirimycin on human bone
marrow neutrophil maturation.
AB - The effects of the N-linked oligosaccharide inhibitors swainsonine and N
butyldeoxynojirimycin (NB-DNJ) on granulopoiesis was investigated using human
bone marrow cells in in vitro liquid and agar cultures. The addition of the
inhibitors into cultures containing granulocyte colony-stimulating factor (G-CSF)
suppressed maturation from myelocytes into mature neutrophils. Swainsonine did
not induce apoptosis, but NB-DNJ induced considerable apoptosis, especially in
the presence of G-CSF. This result indicated that the decrease of mature
neutrophils by swainsonine was not because of cell degeneration. In the case of
NB-DNJ, it was thought to be because of both maturation suppression and
apoptosis. In a colony-forming unit-granuloid (CFU-G) colony assay, the number of
colonies was increased in the presence of the inhibitors, but the morphology of
colonies was predominantly compact, or immature. The inhibitors also suppressed
the expressions of mRNAs of CCAAT/enhancer binding protein epsilon (C/EBPepsilon)
and G-CSF receptor as markers of terminal neutrophil maturation. These findings
suggested that the incompleteness of N-linked oligosaccharide leads to the
suppression of terminal neutrophil maturation.
PMID- 10694504
TI - Enhanced prenyltransferase activity and Rab content in rat liver regeneration.
AB - Rabs are small GTP-binding proteins with a regulatory role in intracellular
vesicular traffic. The modulation of their levels and activity in different
physiological situations is poorly understood. During the first cell cycle of rat
liver regeneration we observed a differential regulation of some Rabs, with a
progressive increase of those involved in exocytosis and a progressive decrease
of one involved in endocytosis. This could be related with the need of exposing
growth factor receptors and prolonging the transduction of their signal in
preparation for mitosis. Moreover, we observed an increased activity of protein
prenyltransferases, the enzymes responsible for the prenylation of several
proteins involved in crucial processes of proliferation, without a corresponding
increase in the amount of prenyltransferase protein.
PMID- 10694506
TI - Structure-function relationships of the two surface loops of myosin heavy chain
isoforms from thermally acclimated carp.
AB - The structure-function relationships of fast skeletal myosin isoforms remain
poorly understood. To shed some light, we constructed chimeric myosins comprised
of Dictyostelium myosin heavy chain backbone with carp loop sequences and
analyzed their functional properties. A loop 2-10 chimeric myosin having the loop
2 sequence of the fast skeletal isoform predominantly expressed in carp
acclimated to 10 degrees C showed V(max) in actin-activated Mg(2+)-ATPase
activity 1.4-fold higher than a loop 2-30 chimera constructed from the loop 2
sequence of the dominant isoform in carp acclimated to 30 degrees C. These two
chimera exhibited no significant differences in sliding velocity of actin
filaments in in vitro motility assay. Contrastingly, both loop 1-associated
chimeras, loop 1-10 and loop 1-30, did not differ in both ATPase activity and in
sliding velocity of actin filaments.
PMID- 10694505
TI - Paraoxonase activity is reduced by a pro-atherosclerotic diet in rabbits.
AB - Serum paraoxonase (PON1) is believed to protect against the development of
atherosclerosis because of its ability to retard the oxidation of low-density
lipoprotein (LDL) by hydrolysing LDL-associated phospholipid and cholesteryl
ester hydroperoxides. We have examined the relationship between PON1 and
atherosclerosis development in transgenic rabbits overexpressing human
apolipoprotein (apo) A-I and nontransgenic littermates fed a pro-atherogenic
diet. PON1 activity was higher in transgenic (4006.1 +/- 716.7 nmol/min/ml)
compared to control (3078.5 +/- 623.3 nmol/min/ml) rabbits (P < 0.01) while high
density lipoprotein (HDL) cholesterol was 1.84 +/- 0.54 mmol/L in transgenic
rabbits and 0.57 +/- 0.21 mmol/L in control rabbits (P = 0.0001). After feeding
rabbits a high-cholesterol diet for 14 weeks HDL-cholesterol fell by 70% in both
transgenic and control rabbits (P < 0.001 compared to week 0) PON1 activity fell
by 50% in both groups of rabbits (P < 0. 01 compared to week 0). The amount of
thoracic aortic surface area covered by lesions was 29 +/- 16% in the control
group and 26 +/- 15% in the transgenic group (P = NS). A pro-atherosclerotic diet
reduces PON1 which may exaggerate the effects of the diet on the development of
atherosclerosis.
PMID- 10694507
TI - The cyclic AMP-protein kinase A pathway restrains islet phospholipase A(2)
activation.
AB - Although phospholipase A(2) (PLA(2)) is of importance for insulin secretion, it
is not established how it relates to other signalling mechanisms. This study
examined the crosstalk between PLA(2) and the cyclic AMP (cAMP)-protein kinase A
(PKA) pathway in isolated rat islets. Forskolin, IBMX, and dbcAMP reduced
[(3)H]arachidonic acid ([(3)H]AA) efflux from prelabelled islets during PLA(2)
activation by mellitin or cholecystokinin (CCK-8), while efflux induced by
carbachol was unaffected. The PKA inhibitor myrPKI(14-22) prevented this
reduction of CCK-8-induced efflux. Glucagon-like peptide-1 (GLP-1), gastric
inhibitory polypeptide (GIP), and vasoactive intestinal polypeptide (VIP)
diminished CCK-8-induced efflux. Also in the absence of Ca(2+), forskolin/IBMX
and dbcAMP reduced CCK-8-induced efflux. In parallel with effects on [(3)H]AA,
the expected additive insulin secretion induced by mellitin or CCK-8 in
combination with forskolin or GLP-1, respectively, was reduced. In conclusion,
the cAMP-PKA pathway restrains both Ca(2+)-dependent and Ca(2+)-independent
PLA(2) activation, indicating a regulating crosstalk between these two pathways.
PMID- 10694508
TI - Helicobacter pylori induces formation of stress fibers and membrane ruffles in
AGS cells by rac activation.
AB - Helicobacter pylori induces signaling cascades leading to changes in cytoskeleton
and an inflammatory response. Information on the morphological changes and
cytoskeletal rearrangements induced by attachment of the bacterium is
contradictory and signal transduction pathways are not well known. Since rho
family of small GTPases is known to mediate cytoskeletal response to various
extracellular stimuli, and is also involved in several other important signal
transduction pathways, we have investigated the role of rac and cdc42 in H.
pylori-induced cytoskeletal changes in cultured carcinoma AGS cells. AGS cells
grown with serum expressed actin filaments in the form of short stress fibers and
thin network at the edges, which were depolymerized by removal of serum. In serum
starved cells both type I and type II strains of H. pylori induced formation of
actin filaments and lamellipodia-like structures. Microinjection of active rac
induced similar changes, but injection of inactive rac prevented the effects of
H. pylori, while active or inactive cdc42 did not have any significant effect.
Cytoskeletal effects of H. pylori were inhibited by actinomycin D, but not
completely by cycloheximide. These results indicate that rac activation is
involved in signal transduction cascade leading to cytoskeletal reorganization
induced by H. pylori and that gene activation and synthesis of new proteins is
necessary in this process.
PMID- 10694509
TI - Binding of six chimeric analogs of omega-conotoxin MVIIA and MVIIC to N- and P/Q
type calcium channels.
AB - Replacement of the N-terminal half of omega-conotoxin MVIIC, a peptide blocker of
P/Q-type calcium channels, with that of omega-conotoxin MVIIA significantly
increased the affinity for N-type calcium channels. To identify the residues
essential for subtype selectivity, we examined single reverse mutations from
MVIIA-type to MVIIC-type in this chimeric analog. A reverse mutation from Lys(7)
to Pro(7) decreased the affinity for both P/Q- and N-type channels, whereas that
from Leu(11) to Thr(11) increased the affinity for P/Q-type channels and
decreased the affinity for N-type channels. The roles of these two residues were
confirmed by synthesizing two MVIIC analogs in which Pro(7) and Thr(11) were
replaced with Lys(7) and Leu(11), respectively.
PMID- 10694510
TI - Effects of shear stress on eicosanoid gene expression and metabolite production
in vascular endothelium as studied in a novel biomechanical perfusion model.
AB - This study investigated the effects of shear stress on gene expression of
prostacyclin synthesis-related enzymes cyclooxygenases (COX-1 and COX-2),
prostacyclin synthase (PGS), and thromboxane synthase (TXS) and their metabolites
prostaglandin (PGI(2)) and thromboxane A(2) (TXA(2)) in endothelium of intact
conduit vessels. Paired human umbilical veins were perfused at high/low shear
stress (25/<4 dyn/cm(2)) at identical intraluminal pressure (20 mmHg) for 1.5, 3,
or 6 hours in a computerized vascular model. High shear perfusion induced a
significant, monophasic upregulation of PGS and TXS gene expressions after 6
hours. COX-1 and COX-2 mRNA showed a biphasic response with peaks at 1.5 and 6
hours, with a nadir level at 3 hours. Shear-induced gene expression was
associated with a significantly greater accumulation of 6-keto prostaglandin
F(1alpha) and TXA(2) in the perfusion medium. Thus, shear stress independently of
perfusion pressure alters the expression of prostacyclin synthesis-related
enzymes and the biosynthesis of their vasoactive metabolites.
PMID- 10694511
TI - yam8(+), a Schizosaccharomyces pombe gene, is a potential homologue of the
Saccharomyces cerevisiae MID1 gene encoding a stretch-activated Ca(2+)-permeable
channel.
AB - The Saccharomyces cerevisiae MID1 gene encodes a stretch-activated Ca(2+)
permeable channel. In a protein database, we found a Schizosaccharomyces pombe
gene whose predicted protein shows 26% identical and 62% similar to the Mid1
channel in amino acid sequence. cDNA derived from this gene, designated yam8(+),
was isolated by reverse transcription-polymerase chain reaction (RT-PCR). Further
analysis showed that the Yam8 protein consists of 486 amino acids and has 6
hydrophobic segments. The yam8(+) cDNA, placed under the S. cerevisiae TDH3
promoter, partially complemented the mating pheromone-induced death (mid)
phenotype of the S. cerevisiae mid1 mutant. The expression of the yam8(+) cDNA in
the mid1 mutant cells partially remediated the mid phenotype and resulted in a
slight increase in Ca(2+) uptake activity. These findings suggest that Yam8 is a
potential homologue of Mid1.
PMID- 10694512
TI - Involvement of hepatic nuclear factor I binding motif in transcriptional
regulation of Ca(2+)-binding protein regucalcin gene.
AB - The characterization of the binding of nuclear protein on the 5'-flanking region
of the rat regucalcin gene was investigated. Nuclear extracts from rat liver and
H4-II-E hepatoma cells were used for oligonucleotide competition gel mobility
shift assay. An oligonucleotide between position -523 and -506 in the 5'-flanking
region of the rat regucalcin gene, which contains a nuclear factor I (NF1)
consensus motif TTGGC(N)(6)CC, competed with the probe for the binding of the
nuclear proteins from rat liver and H4-II-E cells. The mutation of TTGGC in the
consensus sequence caused an inhibition of the binding of nuclear factors. The
presence of Bay K 8644, insulin, and phorbol esters could stimulate the binding
of the nuclear factors to the TTGGC region of the rat regucalcin gene in H4-II-E
cells. The specific mutation introduced in this region, which was ligated to a
luciferase reporter gene, reduced significantly the effects of Bay K 8644,
insulin, and phorbol esters in stimulating the regucalcin gene transcriptional
activity in H4-II-E cells. These results suggest that the specific nuclear factor
binds to the NF1-like sequence, which can stimulate the transcriptional activity,
in the promoter region of regucalcin gene in liver cells.
PMID- 10694513
TI - Tyrosine phosphatase SHP-2 binding to CTLA-4: absence of direct YVKM/YFIP motif
recognition.
AB - CTLA-4 is well documented in its negative regulation of T-cell proliferation.
However, little is known regarding the signaling mechanisms induced by CTLA-4.
CTLA-4 associates with the phosphatidylinositol 3-kinase, the phosphatase SHP-2
and the clathrin adaptor complexes AP-1 and AP-2. SHP-2 SH2 domain binding to
CTLA-4 is unusual given the absence of a I/VxYxxI/V/L motif. Here, we demonstrate
that the phosphorylation of CTLA-4 tyrosines (YVKM and YFIP) fails to allow for
single or tandem SHP-2 SH2 domain binding. This was observed using wild-type and
inactive SHP-2 as well as a construct with the isolated two SH2 domains. The
phosphorylated YVKM and YFIP motifs therefore do not appear to represent novel
binding motifs for SHP-2 SH2 domains. At the same time, we could confirm that SHP
2 can associate with CTLA-4 in murine T-cells indicating that the interaction
between the phosphatase and CTLA-4 is an indirect event, possibly mediated by PI
3-kinase/SHP-2 binding.
PMID- 10694514
TI - Induction of leukemia cell differentiation and apoptosis by recombinant P48, a
modulin derived from Mycoplasma fermentans.
AB - P48 is a 48-kDa monocytic differentiation/activation factor which was originally
identified in the conditioned medium of the Reh and other leukemia cell lines and
has recently been shown to be a Mycoplasma fermentans gene product. Previously,
conditioned medium P48 has been shown to induce differentiation of HL-60 (human
promyelocytic leukemia) cells. Recently our laboratory isolated cDNA clones for
P48 from Reh cells and genomic clones from Mycoplasma fermentans and expressed
the recombinant protein as a maltose binding protein (MBP) fusion protein in E.
coli. In this report we present the initial characterization of this recombinant
P48 fusion protein (rP48-MBP). We show that rP48-MBP induces differentiation of
HL-60, U937 (human histiocytic lymphoma), and M1 (mouse myeloid leukemia) cell
lines. Interestingly, rP48-MBP also induces apoptosis of U937 and HL-60 cells as
assessed by terminal transferase (TUNEL) assays. This is the first report of
induction of apoptosis by a Mycoplasma gene product. P48 is a Mycoplasma-derived
immunomodulatory molecule which has differentiation and apoptosis-inducing
activities and may be important in the pathophysiology of Mycoplasma infections.
The recombinant protein may be useful in studying the mechanisms of
differentiation, cytokine production, and apoptosis in malignant and nonmalignant
hematopoietic cells.
PMID- 10694516
TI - Circulation Online Only : February 29, 2000.
PMID- 10694515
TI - Identification of benzodiazepines in Artemisia dracunculus and Solanum tuberosum
rationalizing their endogenous formation in plant tissue.
AB - Sterile cultivated plant cell tissues and cell regenerates of several species
were tested for their binding affinity to the central human benzodiazepine
receptor. Binding activity was found in extracts of Artemisia dracunculus cell
tissue (IC(50) = 7 microg/ml) and, to a lesser extent, in plant regenerates of
potato herb (Solanum tuberosum). Preparative HPLC led to the isolation of
fractions with a significant displacing potency in the benzodiazepine receptor
binding assay. Using on-line HPLC-electrospray-tandem mass spectrometry (HPLC-ESI
MS/MS) in the "selected reaction monitoring" (SRM) mode, delorazepam and
temazepam were found in amounts of about 100 to 200 ng/g cell tissue of Artemisia
dracunculus, whereas sterile potato herb contained temazepam and diazepam ranging
approximately from 70 to 450 ng/g cell tissue. It is the first report on the
endogenous formation of benzodiazepines by plant cells, as any interaction of
microorganisms and environmental factors was excluded.
PMID- 10694517
TI - Long-term His-bundle pacing and cardiac function.
PMID- 10694518
TI - Patent foramen ovale is indicted, but the case hasn't gone to trial.
PMID- 10694519
TI - New approaches to pulmonary hypertension: will therapies in mice work in humans?
PMID- 10694520
TI - Elevated levels of shed membrane microparticles with procoagulant potential in
the peripheral circulating blood of patients with acute coronary syndromes.
AB - BACKGROUND: Apoptotic microparticles are responsible for almost all tissue factor
activity of the plaque lipid core. We hypothesized that elevated levels of
procoagulant microparticles could also circulate in the peripheral blood of
patients with recent clinical signs of plaque disruption and thrombosis. METHODS
AND RESULTS: We studied 39 patients with coronary heart disease, including 12
patients with stable angina and 27 patients with acute coronary syndromes (ACS),
and 12 patients with noncoronary heart disease. We isolated the circulating
microparticles by capture with annexin V and determined their procoagulant
potential with a prothrombinase assay. The cell origins of microparticles were
determined in an additional 22 patients by antigenic capture with specific
antibodies. The level of procoagulant microparticles did not differ between
stable angina patients and noncoronary patients (10.1+/-1.6 nmol/L
phosphatidylserine [PS] equivalent versus 9.9+/-1.6 nmol/L PS equivalent,
respectively). However, procoagulant microparticles were significantly elevated
in patients with ACS (22.2+/-2.7 nmol/L PS equivalent) compared with other
coronary (P<0.01) or noncoronary (P<0.01) patients. Microparticles of endothelial
origin were significantly elevated in patients with ACS (P<0.01), which suggests
an important role for endothelial injury in inducing the procoagulant potential.
CONCLUSIONS: High levels of procoagulant endothelial microparticles are present
in the circulating blood of patients with ACS and may contribute to the
generation and perpetuation of intracoronary thrombi.
PMID- 10694521
TI - Maximally recommended doses of angiotensin-converting enzyme (ACE) inhibitors do
not completely prevent ACE-mediated formation of angiotensin II in chronic heart
failure.
AB - BACKGROUND: The added benefits of angiotensin II type I receptor (AT(1)) blockers
(ARBs) to ACE inhibition suggests that recommended doses of ACE inhibitors
provide only partial inhibition of ACE in chronic heart failure (CHF).
Accordingly, the level of ACE inhibition was assessed by the pressor response to
angiotensin (Ang) I in patients who had been treated with recommended doses of
ACE inhibitors. METHODS AND RESULTS: Forty-two patients with CHF receiving 40
mg/d of a long-acting ACE inhibitor or 150 mg of captopril were studied. Radial
artery systolic pressure (RASP, mm Hg) was monitored noninvasively. The pressor
response to ascending doses of Ang I was evaluated in all patients before and
after administration of the ARB valsartan. The pressor response to Ang I before
and after valsartan was also reevaluated in 11 patients after the dose of ACE
inhibitor was doubled for 1 week. RASP increased linearly with significantly
ascending doses of Ang I despite treatment with ACE inhibitors. The pressor
response to Ang I was blunted significantly by valsartan. Ang I-induced increase
in RASP did not correlate with duration of ACE inhibitor therapy. After the dose
of ACE inhibitors was doubled, the pressor response to Ang I was no longer
different from that noted after valsartan. CONCLUSIONS: Recommended doses of ACE
inhibitors do not fully inhibit ACE in CHF. The level of ACE inhibition achieved
is not related to duration of ACE inhibitor therapy. Greater ACE inhibition is
also achieved at twice the recommended doses of ACE inhibitors.
PMID- 10694522
TI - Transcatheter closure of atrial septal defects without fluoroscopy: feasibility
of a new method.
AB - BACKGROUND: In an effort to reduce x-ray exposure, we developed a technique for
transcatheter closure of atrial septal defects under echocardiographic guidance
without fluoroscopy. To assess the efficiency of this procedure for routine use,
we compared our initial results with those for the conventional procedure.
METHODS AND RESULTS: Twenty-two randomly selected patients (median age 18 years;
range 2 to 66 years) with atrial septal defects (n=13) or patent foramen ovale
(n=9) underwent cardiac catheterization for possible interventional defect
closure with echocardiography as the only imaging tool. Median stretched diameter
was 9 mm (range 6 to 26 mm); median left-to-right shunt over the atrial septal
defects was Qp/Qs=1.8 (range 1.5 to 2.6). An Amplatzer septal occluder was
successfully implanted in 19 defects without fluoroscopy and in 3 with the help
of radiography. After 1 month, complete defect closure was documented in all
patients. Compared with the conventional procedure of a control group of 131
patients, procedure times were not significantly different (88 versus 100
minutes; P=0.09). However, the study group received significantly higher doses of
propofol for sedation (9.9 versus 5.6 mg/kg body weight; P=0.002) owing to
extended transesophageal echocardiography. CONCLUSIONS: In the majority of
patients in whom transcatheter closure of interatrial communications with the
Amplatzer septal occluder is possible, the procedure can be safely performed
under echocardiographic guidance without fluoroscopy.
PMID- 10694523
TI - Identification of patients at increased risk of first unheralded acute myocardial
infarction by electron-beam computed tomography.
AB - BACKGROUND: There is a clear relationship between absolute calcium scores (CS)
and severity of coronary artery disease. However, hard coronary events have been
shown to occur across all ranges of CS. METHODS AND RESULTS: We conducted 2
analyses: in group A, 172 patients underwent electron-beam CT (EBCT) imaging
within 60 days of suffering an unheralded myocardial infarction. In group B, 632
patients screened by EBCT were followed up for a mean of 32+/-7 months for the
development of acute myocardial infarction or cardiac death. The mean patient age
and prevalence of coronary calcification were similar in the 2 groups (53+/-8
versus 52+/-9 years and 96% each). In group B, the annualized event rate was
0.11% for subjects with CS of 0, 2.1% for CS 1 to 99, 4.1% for CS 100 to 400, and
4.8% for CS >400, and only 7% of the patients had CS >400. However, mild,
moderate, and extensive absolute CSs were distributed similarly between patients
with events in both groups (34%, 35%, and 27%, respectively, in group A and 44%,
30%, and 22% in group B). In contrast, the majority of events in both groups
occurred in patients with CS >75th percentile (70% in each group). CONCLUSIONS:
Coronary calcium is present in most patients who suffer acute coronary events.
Although the event rate is greater for patients with high absolute CSs, few
patients have this degree of calcification on a screening EBCT. Conversely, the
majority of events occur in individuals with high CS percentiles. Hence, CS
percentiles constitute a more effective screening method to stratify individuals
at risk.
PMID- 10694524
TI - Study on the relationship between plasma nitrite and nitrate level and salt
sensitivity in human hypertension : modulation of nitric oxide synthesis by salt
intake.
AB - BACKGROUND: High salt intake suppresses the effect of nitric oxide (NO) in the
peripheral resistance vessels in animal models. We tested the hypothesis that the
modulation of endogenous NO is related to salt sensitivity in human hypertension.
METHODS AND RESULTS: Inpatients with essential hypertension (n=24) were
maintained on a normal-salt diet (12 g/d NaCl) for 3 days, a low-salt diet (2 g),
a high-salt diet (20 to 23 g), and a low-salt diet for 7 days. Normotensive
subjects (n=16) were maintained on the first 2 salt diets. The hypertensive
patients whose average 24-hour blood pressure was increased by >5% by salt
loading were assigned to group 1 (n=8) and the others to group 2 (n=16). Nitrate
plus nitrite (NO(x)) was measured by the Griess method, and asymmetrical
dimethylarginine (ADMA) by high-performance liquid chromatography. The plasma
NO(x) level during the normal-salt diet was lower in group 1 than in group 2 and
the normotensive group. After salt loading, the plasma NO(x) level was decreased
and reversed after the second salt restriction. Plasma ADMA level was increased
after salt loading and decreased after salt restriction. The change in plasma
NO(x) level was correlated inversely with those in blood pressure (r=-0.59,
P=0.0007) and plasma ADMA level (r=-0.64, P=0.003) after salt loading and
restriction. CONCLUSIONS: Modulation of NO synthesis by salt intake may be
involved in a mechanism for salt sensitivity in human hypertension, presumably
via the change in ADMA.
PMID- 10694525
TI - Influence of the menstrual cycle on sympathetic activity, baroreflex sensitivity,
and vascular transduction in young women.
AB - BACKGROUND: Our goal was to test sympathetic and cardiovagal baroreflex
sensitivity and the transduction of sympathetic traffic into vascular resistance
during the early follicular (EF) and midluteal (ML) phases of the menstrual
cycle. METHODS AND RESULTS: Sympathetic baroreflex sensitivity was assessed by
lowering and raising blood pressure with intravenous bolus doses of sodium
nitroprusside and phenylephrine. It was defined as the slope relating muscle
sympathetic nerve activity (MSNA; determined by microneurography) and diastolic
blood pressure. Cardiovagal baroreflex sensitivity was defined as the slope
relating R-R interval and systolic blood pressure. Vascular transduction was
evaluated during ischemic handgrip exercise and postexercise ischemia, and it was
defined as the slope relating MSNA and calf vascular resistance (determined by
plethysmography). Resting MSNA (EF, 1170+/-151 U/min; ML, 2252+/-251 U/min;
P<0.001) and plasma norepinephrine levels (EF, 240+/-21 pg/mL; ML, 294+/-25
pg/mL; P=0. 025) were significantly higher in the ML than in the EF phase.
Furthermore, sympathetic baroreflex sensitivity was greater during the ML than
the EF phase in every subject (MSNA/diastolic blood pressure slopes: EF, -4.15;
FL, -5.42; P=0.005). No significant differences in cardiovagal baroreflex
sensitivity or vascular transduction were observed. CONCLUSIONS: The present
study suggests that the hormonal fluctuations that occur during the normal
menstrual cycle may alter sympathetic outflow but not the transduction of
sympathetic activity into vascular resistance.
PMID- 10694526
TI - Permanent, direct His-bundle pacing: a novel approach to cardiac pacing in
patients with normal His-Purkinje activation.
AB - BACKGROUND: Direct His-bundle pacing (DHBP) produces synchronous ventricular
depolarization and improved cardiac function relative to apical pacing. Although
it has been performed transiently in the electrophysiology laboratory and
persistently in open-chested canines, permanent DHBP in humans has not been
achieved. METHODS AND RESULTS: A total of 18 patients aged 69+/-10 years who had
a history of chronic atrial fibrillation, dilated cardiomyopathy, and normal
activation (ie, QRS< or =120 ms) were screened for permanent DHBP using an
electrophysiology catheter. In 14 patients, the His bundle could be reliably
stimulated. Of these 14, permanent DHBP using a fixed screw-in lead was
successful in 12 patients. Radiofrequency atrioventricular node ablation was
performed in patients exhibiting a fast ventricular response. All patients
received single-chamber rate-responsive pacemakers. Acute pacing thresholds were
2.4+/-1.0 V at a pulse duration of 0.5 ms. Lead complications included exit block
requiring reoperative adjustment and gross lead dislodgment. Echocardiographic
improvement in heart function was shown by reductions in the left ventricular end
diastolic dimension from 59+/-8 to 52+/-6 mm (P=0.01) and in the end-systolic
dimension from 51+/-10 to 43+/-8 mm (P<0.01), with an accompanying increase in
fractional shortening from 14+/-7% to 20+/-10% (P=0.05). The left ventricular
ejection fraction improved from 20+/-9% to 31+/-11% (P<0. 01), and the
cardiothoracic ratio decreased from 0.61+/-0.06 to 0. 57+/-0.07 (P<0.01). Despite
DHBP, 2 patients died at 8 and 36 months. Conclusions-Permanent DHBP is feasible
in select patients who have chronic atrial fibrillation and dilated
cardiomyopathy. Long-term, DHBP results in a reduction of left ventricular
dimensions and improved cardiac function.
PMID- 10694527
TI - Detection of atrial fibrillation and flutter by a dual-chamber implantable
cardioverter-defibrillator. For the Worldwide Jewel AF Investigators.
AB - BACKGROUND: To distinguish prolonged episodes of atrial fibrillation (AF) that
require cardioversion from self-terminating episodes that do not, an atrial
implantable cardioverter-defibrillator (ICD) must be able to detect AF
continuously for extended periods. The ICD should discriminate between atrial
tachycardia/flutter (AT), which may be terminated by antitachycardia pacing, and
AF, which requires cardioversion. METHODS AND RESULTS: We studied 80 patients
with AT/AF and ventricular arrhythmias who were treated with a new atrial/dual
chamber ICD. During a follow-up period lasting 6+/-2 months, we validated
spontaneous, device-defined AT/AF episodes by stored electrograms in all
patients. In 58 patients, we performed 80 Holter recordings with telemetered
atrial electrograms, both to validate the continuous detection of AT/AF and to
determine the sensitivity of the detection of AT/AF. Detection was appropriate in
98% of 132 AF episodes and 88% of 190 AT episodes (98% of 128 AT episodes with an
atrial cycle length <300 ms). Intermittent sensing of far-field R waves during
sinus tachycardia caused 27 inappropriate AT/AF detections; these detections
lasted 2.6+/-2.0 minutes. AT/AF was detected continuously in 27 of 28 patients
who had spontaneous episodes of AT/AF (96%). The device memory recorded 90
appropriate AT/AF episodes lasting >1 hour, for a total of 2697 hours of
continuous detection of AT/AF. During Holter monitoring, the sensitivity of the
detection of AT/AF (116 hours) was 100%; the specificity of the detection of non
AT/AF rhythms (1290 hours) was 99.99%. Of 166 appropriate episodes detected as
AT, 45% were terminated by antitachycardia pacing. CONCLUSIONS: A new ICD detects
AT/AF accurately and continuously. Therapy may be programmed for long-duration
AT/AF, with a low risk of underdetection. Discrimination of AT from AF permits
successful pacing therapy for a significant fraction of AT.
PMID- 10694528
TI - Oscillatory patterns in sympathetic neural discharge and cardiovascular variables
during orthostatic stimulus.
AB - BACKGROUND: We tested the hypothesis that a common oscillatory pattern might
characterize the rhythmic discharge of muscle sympathetic nerve activity (MSNA)
and the spontaneous variability of heart rate and systolic arterial pressure
(SAP) during a physiological increase of sympathetic activity induced by the head
up tilt maneuver. METHODS AND RESULTS: Ten healthy subjects underwent continuous
recordings of ECG, intra-arterial pressure, respiratory activity, central venous
pressure, and MSNA, both in the recumbent position and during 75 degrees head-up
tilt. Venous samplings for catecholamine assessment were obtained at rest and
during the fifth minute of tilt. Spectrum and cross-spectrum analyses of R-R
interval, SAP, and MSNA variabilities and of respiratory activity provided the
low (LF, 0.1 Hz) and high frequency (HF, 0.27 Hz) rhythmic components of each
signal and assessed their linear relationships. Compared with the recumbent
position, tilt reduced central venous pressure, but blood pressure was unchanged.
Heart rate, MSNA, and plasma epinephrine and norepinephrine levels increased,
suggesting a marked enhancement of overall sympathetic activity. During tilt,
LF(MSNA) increased compared with the level in the supine position; this mirrored
similar changes observed in the LF components of R-R interval and SAP
variabilities. The increase of LF(MSNA) was proportional to the amount of the
sympathetic discharge. The coupling between LF components of MSNA and R-R
interval and SAP variabilities was enhanced during tilt compared with rest.
CONCLUSIONS: During the sympathetic activation induced by tilt, a similar
oscillatory pattern based on an increased LF rhythmicity characterized the
spontaneous variability of neural sympathetic discharge, R-R interval, and
arterial pressure.
PMID- 10694529
TI - Percutaneous closure of patent foramen ovale in patients with paradoxical
embolism: long-term risk of recurrent thromboembolic events.
AB - BACKGROUND: Patients with a patent foramen ovale (PFO) and paradoxical embolism
are at risk for recurrent thromboembolic events. This study investigated the long
term risk of recurrent thromboembolic events in patients with PFO and paradoxical
embolism after percutaneous PFO closure. METHODS AND RESULTS: Since 1994, a total
of 80 patients with PFO and at least 1 paradoxical embolic event (transient
ischemic attack [TIA], cerebrovascular accident [CVA], peripheral embolism) have
undergone percutaneous PFO closure with 5 different devices. There were 30 women
and 50 men, with a mean age of 52+/-12 years. Sixty patients had only a PFO,
whereas 20 patients had both a PFO and an atrial septal aneurysm. The
implantation procedure was successful in 78 patients (98%). During 5 years of
follow-up (mean, 1.6+/-1.4 years; range, 0.1 to 5.0 years), the actuarial annual
risk to suffer a recurrent thromboembolic event was 2.5% for TIA, 0% for CVA,
0.9% for peripheral emboli, and 3.4% for the combined end point of TIA, CVA, or
peripheral embolism. A postprocedural shunt was a predictor of recurrent
paradoxical embolism (RR, 4.2; 95% CI, 1.1 to 17.8; P=0.03). The risk for
recurrent thromboembolic events in patients with both atrial septal aneurysm and
PFO was not significantly increased compared with patients with only PFO (RR,
1.0; 95% CI, 0.2 to 4.7; P=0.95). CONCLUSIONS: Percutaneous PFO closure appears
to be a promising technique in the prevention of recurrent systemic
thromboembolism in patients with a PFO after a first event. Prospective studies
comparing percutaneous PFO closure with antithrombotic medications or surgery
must define its therapeutic value.
PMID- 10694530
TI - Alteration in left ventricular diastolic filling and accumulation of myocardial
collagen at insulin-resistant prediabetic stage of a type II diabetic rat model.
AB - BACKGROUND: Considerable controversy exists regarding impairment of cardiac
function in diabetes mellitus (DM). We investigated the serial changes in left
ventricular (LV) histopathology and LV filling dynamics in Otsuka Long-Evans
Tokushima Fatty (OLETF) rats, which have been established as an animal model of
type II DM. METHODS AND RESULTS: In 54 OLETF and 54 non-DM rats, body weight,
blood pressure, heart rate, and transmitral pulsed Doppler examinations were
performed from 5 to 47 weeks of age. An oral glucose tolerance test was performed
at 10, 20, and 30 weeks of age. The hearts were excised for histopathology,
including immunohistochemistry and histomorphometry of collagen, and measurement
of hydroxyproline at baseline and each stage of developing DM. In the prediabetic
stage (15 weeks of age), in which fast blood glucose remained normal, OLETF rats
manifested mild obesity, postprandial hyperglycemia, and hyperinsulinemia, and
early diastolic transmitral inflow exhibited prolonged deceleration time (OLETF,
59+/-10 ms versus non-DM, 49+/-8 ms, P<0.01) and low peak velocity (OLETF, 73+/
11 cm/s versus non-DM, 88+/-11 cm/s, P<0.01). Histopathology revealed
extracellular fibrosis and abundant transforming growth factor-beta(1) receptor
II in LV myocytes of OLETF rats. At 15 weeks of age, the ratio of collagen
area/visual field of LV wall in OLETF rats (8.3+/-1.3%) was larger than that in
non-DM rats (4.9+/-1.8%, P<0.0001), and the collagen content/dry tissue weight
ratio of heart was significantly higher in OLETF (2. 0+/-0.5 mg/g) than non-DM
(1.3+/-0.2 mg/g, P<0.01) rats. CONCLUSIONS: A metabolic abnormality present in
the prestage of type II DM may produce LV fibrosis and alteration in cardiac
function.
PMID- 10694531
TI - Interleukin-10 inhibits intimal hyperplasia after angioplasty or stent
implantation in hypercholesterolemic rabbits.
AB - BACKGROUND: Intimal hyperplasia after stent implantation is the main cause of in
stent restenosis. Activated monocytes play a key role in intimal growth. The anti
inflammatory cytokine interleukin-10 (IL-10) is a potent monocyte deactivator,
endogenously produced in the atherosclerotic plaque. We tested the hypothesis
that exogenous IL-10 may limit postangioplasty intimal hyperplasia after balloon
angioplasty or stenting. METHODS AND RESULTS: Hypercholesterolemic rabbits were
treated with recombinant human IL-10 (rhuIL-10) for 3 days after balloon
angioplasty or 28 days after stent implantation. High IL-10 serum levels and
intense deactivation of circulating monocytic cells, assessed by inhibition of IL
1beta release by lipopolysaccharide-stimulated whole blood, were detected for at
least 8 hours after rhuIL-10 intravenous injection (ELISA). Morphometric
analyses, performed 28 days after injury, indicated that rhuIL-10 reduced intimal
growth by approximately 50% after balloon angioplasty or stenting, resulting in
more preserved lumen in stented arteries. Moreover, rhuIL-10 reduced macrophage
infiltration by 67% and proliferative activity by 81% in the intima and the
media. No toxic effect was detected except minor changes in blood cell count.
CONCLUSIONS: The anti-inflammatory cytokine rhuIL-10 reduces postinjury intimal
hyperplasia. The potent attenuation of in-stent intimal growth by rhuIL-10 and
its favorable toxicity profile suggest that rhuIL-10 may be useful in the
prevention of in-stent restenosis.
PMID- 10694532
TI - Persistent changes in myocardial glucose metabolism in vivo during reperfusion of
a limited-duration coronary occlusion.
AB - BACKGROUND: Rapid reperfusion of an occluded coronary artery salvages regional
mechanical function, but this benefit may not be realized for hours or days
because of postischemic stunning. Recovery from stunning is incompletely
understood but may involve adaptive changes in heart glucose metabolism. METHODS
AND RESULTS: To examine whether reversible coronary occlusion produces sustained
changes in regional glucose metabolism in vivo, we performed a 20-minute left
coronary artery occlusion followed by 24 hours of open-artery reperfusion in
intact rats. Coronary occlusion produced stunning of the anterolateral left
ventricle that resolved over 24 hours. When examined at 24 hours, reperfused
regions were fully contractile and viable by vital staining and microscopy but
demonstrated 25% reduction in blood flow and 50% increased uptake of circulating
glucose, as estimated by in vivo [(13)N]NH(3) and [(18)F]fluorodeoxyglucose (FDG)
tracer uptake. Reperfused regions had largely inactive glycogen synthase, low
rates of glycogen synthesis, and persistent 50% glycogen depletion but increased
flux of plasma [1-(13)C]glucose into myocardial [3-(13)C]alanine, indicating
preferential shunting of imported glucose away from storage and into glycolysis.
CONCLUSIONS: Sustained increases in regional glycolytic consumption of
circulating glucose occur during reperfusion of a limited-duration coronary
occlusion. This suggests a role for glycolytic ATP in the recovery from
postischemic stunning in vivo. Furthermore, [(13)N]NH(3) /FDG regional mismatch
may constitute a clinically accessible late metabolic signature of regional
myocardial ischemia.
PMID- 10694534
TI - Resistance to endotoxin shock in transgenic mice overexpressing endothelial
nitric oxide synthase.
AB - BACKGROUND: Nitric oxide (NO) plays a central role in the pathogenesis of septic
shock. However, the role of the NO produced by endothelial NO synthase (eNOS) in
septic shock is still unclear. We examined the effect of chronic eNOS
overexpression and the role of eNOS-derived NO in lipopolysaccharide (LPS)
induced septic shock using eNOS transgenic (Tg) mice. METHODS AND RESULTS: LPS
was intraperitoneally injected into Tg and control mice. No differences existed
in the peak plasma nitrate and nitrate levels induced by LPS between the 2
genotypes. In LPS-treated control mice, blood pressure progressively declined and
reached 60% of basal levels (from 97+/-3 to 59+/-3 mm Hg) 24 hours after LPS
injection. In contrast, the blood pressure of LPS-treated Tg mice fell only 15%
from basal levels (from 84+/-4 to 71+/-4 mm Hg) after the first 6 hours and,
thereafter, it remained at this level. LPS-induced increases in the expression of
the mRNA of both vascular cell adhesion molecule-1 and intracellular adhesion
molecule-1 in the lungs were significantly lower in Tg mice than in control mice.
LPS-induced pulmonary leukocyte infiltration and increases in lung water content
were also significantly attenuated in Tg mice. Histological examination revealed
that lung injury after LPS injection was milder in Tg mice. Furthermore, Tg mice
exhibited enhanced survival from LPS-induced septic shock compared with control
mice. CONCLUSIONS: Chronic eNOS overexpression in the endothelium of mice
resulted in resistance to LPS-induced hypotension, lung injury, and death. These
effects are associated with the reduced vascular reactivity to NO and the reduced
anti-inflammatory effects of NO.
PMID- 10694533
TI - In vivo gene transfer of prepro-calcitonin gene-related peptide to the lung
attenuates chronic hypoxia-induced pulmonary hypertension in the mouse.
AB - BACKGROUND: Calcitonin gene-related peptide (CGRP) is believed to play an
important role in maintaining low pulmonary vascular resistance (PVR) and in
modulating pulmonary vascular responses to chronic hypoxia; however, the effects
of adenovirally mediated gene transfer of CGRP on the response to hypoxia are
unknown. METHODS AND RESULTS: In the present study, an adenoviral vector encoding
prepro-CGRP (AdRSVCGRP) was used to examine the effects of in vivo gene transfer
of CGRP on increases in PVR, right ventricular mass (RVM), and pulmonary vascular
remodeling that occur in chronic hypoxia in the mouse. Intratracheal
administration of AdRSVCGRP, followed by 16 days of chronic hypoxia (FIO(2)
0.10), increased lung CGRP and cAMP levels. The increase in pulmonary arterial
pressure (PAP), PVR, RVM, and pulmonary vascular remodeling in response to
chronic hypoxia was attenuated in animals overexpressing prepro-CGRP, whereas
systemic pressure was not altered while in chronically hypoxic mice, angiotensin
II and endothelin-1-induced increases in PAP were reduced, whereas decreases in
PAP in response to CGRP and adrenomedullin were not changed and decreases in PAP
in response to a cAMP phosphodiesterase inhibitor were enhanced by AdRSVCGRP.
CONCLUSIONS: In vivo CGRP lung gene transfer attenuates the increase in PVR and
RVM, pulmonary vascular remodeling, and pressor responses in chronically hypoxic
mice, suggesting that CGRP gene transfer alone and with a cAMP phosphodiesterase
inhibitor may be useful for the treatment of pulmonary hypertensive disorders.
PMID- 10694535
TI - Images in cardiovascular medicine. Abciximab-associated pseudothrombocytopenia.
PMID- 10694536
TI - Diagnosis of an intracoronary thrombus with intravascular ultrasound.
PMID- 10694537
TI - Cardiac interleukin-6 in ischemic myocardium.
PMID- 10694538
TI - Alpha-adrenergic blockade in myocardial infarction.
PMID- 10694539
TI - The nature of the statins.
PMID- 10694540
TI - Sildenafil/nitrate interaction.
PMID- 10694541
TI - Long-term results of percutaneous balloon mitral valvuloplasty using the Inoue
balloon catheter technique.
PMID- 10694542
TI - Myelodysplasia and acute leukemia after autologous bone marrow transplantation.
PMID- 10694543
TI - Therapy-related myelodysplasia and secondary acute myelogenous leukemia after
high-dose therapy with autologous hematopoietic progenitor-cell support for
lymphoid malignancies.
AB - PURPOSE: To evaluate the incidence of and risk factors for therapy-related
myelodysplasia (tMDS) and secondary acute myelogenous leukemia (sAML), after high
dose therapy (HDT) with autologous bone marrow or peripheral-blood progenitor
cell support, in patients with non-Hodgkin's lymphoma (NHL). PATIENTS AND
METHODS: Between January 1985 and November 1996, 230 patients underwent HDT
comprising cyclophosphamide therapy and total-body irradiation, with autologous
hematopoietic progenitor-cell support, as consolidation of remission. With a
median follow-up of 6 years, 27 (12%) developed tMDS or sAML. RESULTS: Median
time to development of tMDS or sAML was 4.4 years (range, 11 months to 8.8 years)
after HDT. Karyotyping (performed in 24 cases) at diagnosis of tMDS or sAML
revealed complex karyotypes in 18 patients. Seventeen patients had monosomy 5/5q
, 15 had -7/7q-, seven had -18/18q-, seven had -13/13q-, and four had -20/20q-.
Twenty-one patients died from complications of tMDS or sAML or treatment for tMDS
or sAML, at a median of 10 months (range, 0 to 26 months). Sixteen died without
evidence of recurrent lymphoma. Six patients were alive at a median follow-up of
6 months (range, 2 to 22 months) after diagnosis of tMDS or sAML. On multivariate
analysis, prior fludarabine therapy (P =.009) and older age (P =.02) were
associated with the development of tMDS or sAML. Increased interval from
diagnosis to HDT and bone marrow involvement at diagnosis were of borderline
significance (P =.05 and.07, respectively). CONCLUSION: tMDS and sAML are serious
complications of HDT for NHL and are associated with very poor prognosis.
Alternative strategies for reducing their incidence and for treatment are needed.
PMID- 10694544
TI - Low-dose 5-aza-2'-deoxycytidine, a DNA hypomethylating agent, for the treatment
of high-risk myelodysplastic syndrome: a multicenter phase II study in elderly
patients.
AB - PURPOSE: 5-Aza-2'-deoxycytidine (decitabine; DAC) is a DNA hypomethylating agent
that has shown a 50% response rate in a small phase II study in elderly patients
with high-risk myelodysplastic syndrome. We performed a second, multicenter phase
II study in a larger group of patients to confirm our findings and to study the
toxicity of DAC. PATIENTS AND METHODS: Between June 1996 and September 1997, 66
patients (median age, 68 years) from seven centers received DAC 45 mg/m(2)/d for
3 days every 6 weeks. For patients in whom a complete response (CR) was reached
after two courses, two further cycles were administered as consolidation therapy.
In case of a stable disease situation, improvement, or a partial response (PR), a
maximum of six cycles was administered. The primary end points were response rate
and toxicity. The secondary end points were response duration, survival from the
start of therapy, and overall survival. RESULTS: The observed overall response
rate was 49%, with a 64% response rate in the patients with an International
Prognostic Scoring System (IPSS) high-risk score. The actuarial median response
duration was 31 weeks, with a response duration of 39 weeks and 36 weeks for
patients who reached a PR or CR, respectively. The actuarial median survival time
from the time of diagnosis was 22 months and from the start of therapy was 15
months. For the IPSS high-risk group, the median survival time was 14 months. The
median progression-free survival time was 25 weeks. Myelosuppression was rather
common, and the treatment-related mortality rate was 7% and was primarily
associated with pancytopenia and infection. Significant responses were observed
with regard to megakaryopoiesis, with increases in platelet counts having already
occurred after one cycle of DAC therapy in the majority of the responding
patients. CONCLUSION: We were able to confirm our previous observation that DAC
therapy was effective in half of the studied patients with high-risk
myelodysplastic syndrome and is especially active in the patients with the worst
prognoses. Myelosuppression was the only major adverse effect observed.
PMID- 10694545
TI - Allogeneic bone marrow transplantation for therapy-related myelodysplastic
syndrome and acute myeloid leukemia: a long-term study of 70 patients-report of
the French society of bone marrow transplantation.
AB - PURPOSE: To identify predictive factors of survival, relapse, and transplantation
related mortality (TRM) among patients with therapy-related myelodysplastic
syndrome (t-MDS) or acute leukemia (t-AML) who underwent allogeneic bone marrow
transplantation (BMT). PATIENTS AND METHODS: From 1980 to 1998, 70 patients
underwent allogeneic BMT for t-MDS (n = 31) or t-AML (n = 39) after prior
cytotoxic exposure. Thirty-three patients had received induction-type
chemotherapy before BMT. At the time of transplantation, there were 24 patients
in complete remission (CR) and 46 with active disease. RESULTS: With a median
follow-up of 7.9 years (range, 1.1 to 18.8 years) after BMT, 16 patients are
alive, whereas 19 died of relapse, 34 of TRM, and one of relapse of the primary
disease. The estimated 2-year overall survival, event-free survival, relapse, and
TRM rates were 30% (95% confidence interval [CI], 19% to 40%), 28% (95% CI, 18%
to 39%), 42% (95% CI, 26% to 57%), and 49% (95% CI, 36% to 62%), respectively. In
multivariable analysis, age greater than 37 years, male sex, positive recipient
cytomegalovirus (CMV) serology, absence of CR at BMT, and intensive schedules
used for conditioning were associated with poor outcome. CONCLUSION: BMT is an
effective treatment for patients with t-MDS or t-AML who have responsive disease
and, in particular, who have no poor-risk cytogenetic features. The poor results
of the other patients, especially those with active disease at BMT, emphasize the
need to delineate indications and perform prospective protocols.
PMID- 10694546
TI - Assessment of the stanford V regimen and consolidative radiotherapy for bulky and
advanced Hodgkin's disease: Eastern Cooperative Oncology Group pilot study E1492.
AB - PURPOSE: This study was performed, in a multi-institutional setting, to evaluate
the efficacy and feasibility of the Stanford V chemotherapy regimen plus
radiotherapy to bulky Hodgkin's disease sites. PATIENTS AND METHODS: A two-stage
design was implemented in a phase II study involving 47 patients with bulky
mediastinal stage I/II or stage III/IV Hodgkin's disease. Twelve weeks of the
Stanford V chemotherapy regimen were given with consolidative radiotherapy (36
Gy) to lymph nodes >/= 5 cm and/or macroscopic splenic disease. Treatment was
administered in one of five institutions participating in the Eastern Cooperative
Oncology Group. RESULTS: With a median follow-up of 4.8 years, 45 patients are
alive and 40 have been continuously disease-free. The estimated freedom from
progression was 87% at 2 years and 85% at 5 years. Overall survival was 96% at 2
and 5 years. There was one death from Hodgkin's disease and one death from an M5
acute leukemia. Six of seven relapsed patients received high-dose therapy and
autologous stem-cell transplantation. The freedom from second progression for the
seven relapsed patients was estimated at 98% at 3 years. CONCLUSION: Stanford V
chemotherapy and consolidative radiotherapy to bulky disease is effective in
bulky and advanced Hodgkin's disease in a multi-institutional setting. On this
basis, an Intergroup study comparing doxorubicin, bleomycin, vinblastine, and
dacarbazine with the Stanford V regimen has been initiated.
PMID- 10694547
TI - Prospective randomized comparison of single-dose versus hyperfractionated total
body irradiation in patients with hematologic malignancies.
AB - PURPOSE: Fractionated total-body irradiation (HTBI) is considered to induce less
toxicity to normal tissues and probably has the same efficacy as single-dose
total-body irradiation (STBI) in patients with acute myeloid leukemia. We decided
to determine whether this concept can be applied to a large number of patients
with various hematologic malignancies using two dissimilar fractionation
schedules. PATIENTS AND METHODS: Between December 1986 and October 1994, 160
patients with various hematologic malignancies were randomized to receive either
a 10-Gy dose of STBI or 14.85-Gy dose of HTBI. RESULTS: One hundred forty-seven
patients were assessable. The 8-year overall survival rate and cause-specific
survival rate in the STBI group was 38% and 63.5%, respectively. Overall survival
rate and cause-specific survival rate in the HTBI group was 45% and 77%,
respectively. The incidence of interstitial pneumonitis was similar in both
groups. However, the incidence of veno-occlusive disease (VOD) of the liver was
significantly higher in the STBI group. In the multivariate analysis with overall
survival as the end point, the female sex was an independent favorable prognostic
factor. On the other hand, when cause-specific survival was considered as the end
point, the multivariate analysis demonstrated that sex and TBI were independent
prognostic factors. CONCLUSION: The efficacy of HTBI is probably higher than that
of STBI. Both regimens induce similar toxicity with the exception of VOD of the
liver, the incidence of which is significantly more pronounced in the STBI group.
PMID- 10694548
TI - Phase I study of fludarabine plus cyclophosphamide in patients with previously
untreated low-grade lymphoma: results and and long-term follow-up--a report from
the Eastern Cooperative Oncology Group.
AB - PURPOSE: To determine the toxicity and recommended phase II doses of the
combination of fludarabine plus cyclophosphamide in chemotherapy-naive patients
with low-grade lymphoma. PATIENTS AND METHODS: Previously untreated patients with
low-grade lymphoma were entered onto dosing cohorts of four patients each. The
cyclophosphamide dose, given on day 1, was increased from 600 to 1, 000 mg/m(2).
Fludarabine 20 mg/m(2) was administered on days 1 through 5. The first eight
patients were treated every 21 days; later patients were treated every 28 days.
Prophylactic antibiotics were required. RESULTS: Prolonged cytopenia and
pulmonary toxicity each occurred in three of eight patients treated every 3
weeks. The 19 patients treated every 28 days, who were given granulocyte colony
stimulating factor as indicated, did not have undue nonhematologic toxicity. Dose
limiting toxicity was hematologic. At the recommended phase II/III dose
(cyclophosphamide 1,000 mg/m(2)), grade 4 neutropenia was observed in 17% of all
cycles and 31% of first cycles. Grade 3 or 4 thrombocytopenia was seen in only 1%
of all cycles. The median number of cycles per patient was six (range, two to 11)
for all patients enrolled. The response rate was 100% of 27 patients entered; 89%
achieved a complete and 11% a partial response. Nineteen of 22 patients with bone
marrow involvement had clearing of the marrow. Median duration of follow-up was
more than 5 years; median overall and disease-free survival times have not been
reached. Kaplan-Meier estimated 5-year overall survival and disease-free survival
rates were 66% and 53%, respectively. CONCLUSION: The recommended dosing for this
combination in patients with previously untreated low-grade lymphoma is
cyclophosphamide 1, 000 mg/m(2) day 1 and fludarabine 20 mg/m(2) days 1 through
5. The regimen has a high level of activity, with prolonged complete remissions
providing 5-year overall and disease-free survival rates as high as those
reported for other therapeutic approaches in untreated patients.
PMID- 10694549
TI - Pharmacokinetics of nelarabine and 9-beta-D-arabinofuranosyl guanine in pediatric
and adult patients during a phase I study of nelarabine for the treatment of
refractory hematologic malignancies.
AB - PURPOSE: To characterize the pharmacokinetics of nelarabine (506U78), the water
soluble prodrug of 9-beta-D-arabinofuranosyl guanine (ara-G), and ara-G in
pediatric and adult patients with refractory hematologic malignancies. Ara-G is
phosphorylated within leukemic cells to form ara-G triphosphate (ara-GTP), which
acts to terminate DNA chain elongation, resulting in cell death. PATIENTS AND
METHODS: The pharmacokinetics of nelarabine and/or ara-G were evaluated in 71
patients (25 pediatric and 46 adult patients) on the first day of therapy. Blood
was collected at specified times for the determination of plasma nelarabine and
ara-G concentrations. RESULTS: There were no statistically significant
differences in the pharmacokinetics of nelarabine between any of the groups of
patients. The harmonic mean half-life (t1/2) of nelarabine in pediatric and adult
patients was 14.1 minutes and 16.5 minutes, respectively. The maximum
concentrations (C(max)) of ara-G occurred at or near the end of the nelarabine
infusion. The C(max) of ara-G ranged from 11.6 micromol/L to 308.7 micromol/L at
nelarabine doses of 5 to 75 mg/kg and was linearly related to the nelarabine
dose. No statistically significant differences were noted for the pharmacokinetic
parameter estimates of ara-G between adult male and female patients. In children
versus adults, the dose-normalized C(max), time of the C(max), and the steady
state volume of distribution of ara-G were similar. However, the clearance of ara
G was higher in pediatric patients (0.312 L.h(-1).kg(-1)) as compared with adult
patients (0. 213 L.h(-1).kg(-1)) (P <.001). The t1/2 of ara-G was shorter in
pediatric patients as compared with adult patients (2.1 hours v 3.0 hours; P
<.01). CONCLUSION: Nelarabine is an effective prodrug of ara-G, allowing systemic
concentrations of ara-G that result in clinical activity.
PMID- 10694550
TI - Cognitive and academic functioning in survivors of pediatric bone marrow
transplantation.
AB - PURPOSE: To evaluate cognitive and academic functioning in survivors of pediatric
bone marrow transplants (BMTs) at 1 and 3 years after a BMT. PATIENTS AND
METHODS: In a prospective, longitudinal design, patients underwent a
comprehensive battery of neurocognitive measures before admission for
transplantation and at 1, 3, and 5 years after a BMT. This article describes a
cohort of 102 survivors with follow-up data available for 1 year after a BMT,
including 54 survivors with follow-up available for 3 years. This represents the
largest cohort of pediatric BMT survivors yet reported in a prospective study.
RESULTS: In the cohort as a whole, there were no significant changes on global
measures of intelligence (intelligence quotient [IQ]) and academic achievement at
either 1 or 3 years after a BMT, despite adequate power to detect an IQ change of
three points or greater. Likewise, performance on specific tests of
neuropsychologic function remained stable. No significant differences were
observed between patients whose conditioning regimen included total-body
irradiation (TBI) and those whose did not. The primary predictor of
neurocognitive outcome was patient age, with younger patients more likely to show
declines over time. The subset of patients who were less than 3 years of age at
the time of transplantation seemed to be particularly vulnerable to cognitive
sequelae. CONCLUSION: The use of BMTs with or without TBI entails minimal risk of
late neurocognitive sequelae in patients who are 6 years of age or older at the
time of transplantation. However, patients who are less than 6 years of age at
the time of transplantation, and particularly those less than 3 years of age,
seem to be at some risk of cognitive declines.
PMID- 10694551
TI - "Low-risk" prediction rule for pediatric oncology patients presenting with fever
and neutropenia.
AB - PURPOSE: To prospectively derive and validate a clinical prediction rule to allow
a more tailored approach to the management of pediatric oncology outpatients
presenting with fever and neutropenia. PATIENTS AND METHODS: The clinical
prediction rule was derived over a 1-year period and then validated over the
following 8 months in a new set of fever and neutropenia episodes. Patients were
excluded if they presented with comorbidity or an abnormal chest x-ray (CXR).
RESULTS: Significant bacterial infection (SBI; defined as any blood or urine
culture positive for bacteria, interstitial or lobar consolidation on CXR, or
unexpected death from infection) was documented in 43 of the 227 episodes.
Multivariate analysis found four significant factors: bone marrow disease,
general appearance unwell on initial examination, monocyte count less than 0.1 x
10(9)/L, and peak oral or oral equivalent temperature greater than 39 degrees C.
Only the monocyte count contributed to determining a low-risk group, excluding
SBI with 84% sensitivity (95% confidence interval [CI], 61% to 100%), 42%
specificity (95% CI, 38% to 46%), and a negative predictive value of 92% (95% CI,
76% to 100%). If the monocyte count was >/= 0.1 x 10(9)/L at the time of
presentation (low risk), the incidences of SBI and bacteremia were 8% and 5%,
respectively, versus 25% and 17% in the high-risk group. When validated in a new
population of 136 episodes of fever and neutropenia, the incidences of SBI and
bacteremia in the low-risk group were 12% and 5%, respectively, and 25% and 19%
in the high-risk group. CONCLUSION: Pediatric oncology outpatients with fever and
neutropenia who present with an initial monocyte count of >/= 0.1 x 10(9)/L and
do not have comorbidity or an abnormal CXR at the time of presentation are at
lower risk for SBI and can be considered for less aggressive initial therapy.
PMID- 10694552
TI - Proton magnetic resonance spectroscopic imaging in children with recurrent
primary brain tumors.
AB - PURPOSE: Proton magnetic resonance spectroscopic imaging ((1)H-MRSI) is a
noninvasive technique for spatial characterization of biochemical markers in
tissues. We measured the relative tumor concentrations of these biochemical
markers in children with recurrent brain tumors and evaluated their potential
prognostic significance. PATIENTS AND METHODS: (1)H-MRSI was performed on 27
children with recurrent primary brain tumors referred to our institution for
investigational drug trials. Diagnoses included high-grade glioma (n = 10),
brainstem glioma (n = 7), medulloblastoma/peripheral neuroectodermal tumor (n =
6), ependymoma (n = 3), and pineal germinoma (n = 1). (1)H-MRSI was performed on
1. 5-T magnetic resonance imagers before treatment. The concentrations of choline
(Cho) and N-acetyl-aspartate (NAA) in the tumor and normal brain were quantified
using a multislice multivoxel method, and the maximum Cho:NAA ratio was
determined for each patient's tumor. RESULTS: The maximum Cho:NAA ratio ranged
from 1.1 to 13.2 (median, 4.5); the Cho:NAA ratio in areas of normal-appearing
brain tissue was less than 1.0. The maximum Cho:NAA ratio for each histologic
subtype varied considerably; approximately equal numbers of patients within each
tumor type had maximum Cho:NAA ratios above and below the median. Patients with a
maximum Cho:NAA ratio greater than 4.5 had a median survival of 22 weeks, and all
13 patients died by 63 weeks. Patients with a Cho:NAA ratio less than or equal to
4.5 had a projected survival of more than 50% at 63 weeks. The difference was
statistically significant (P =.0067, log-rank test). CONCLUSION: The maximum
tumor Cho:NAA ratio seems to be predictive of outcome in children with recurrent
primary brain tumors and should be evaluated as a prognostic indicator in newly
diagnosed childhood brain tumors.
PMID- 10694553
TI - TrkC expression predicts good clinical outcome in primitive neuroectodermal brain
tumors.
AB - PURPOSE: To identify biologic prognostic factors in childhood primitive
neuroectodermal tumors (PNET), including medulloblastoma, that accurately define
patient groups with sufficiently good prognosis to permit a reduction in
treatment intensity. PATIENTS AND METHODS: We determined expression levels of the
neurotrophin receptor TrkC mRNA in formalin-fixed tumor samples from 87 well
characterized PNET patients using in situ hybridization. Comparison of TrkC mRNA
expression levels with clinical and other laboratory variables was performed
using univariate and multivariate Cox regression analysis. RESULTS: High TrkC
mRNA expression was found to be associated more with higher 5-year cumulative
survival rate than was low TrkC mRNA expression (89% v 46%, respectively). When
compared with established clinical prognostic factors and laboratory variables of
potential prognostic significance, TrkC mRNA expression, by univariate analysis,
was found to be the single most powerful predictor of outcome (hazards ratio,
4.81; P <.00005), exceeding all clinical prognostic factors. In multivariate
analysis, the hazards ratio remained significant (P <.00005). CONCLUSION: High
TrkC mRNA expression in PNET is a powerful independent predictor of favorable
clinical outcome. Assessment of TrkC mRNA levels may aid in treatment planning
for patients with PNETs and should be incorporated prospectively into PNET
clinical trials.
PMID- 10694554
TI - Serum human glandular kallikrein-2 protease levels predict the presence of
prostate cancer among men with elevated prostate-specific antigen.
AB - PURPOSE: We hypothesize that serum human glandular kallikrein-2 (hK2) levels
predict the presence of prostate cancer among men prescreened by prostate
specific antigen (PSA). PATIENTS AND METHODS: We conducted a cross-sectional
study of 324 men who had no history of prostate cancer and who were referred for
prostate biopsy. PSA and hK2 levels were measured using specific nonisotopic
immunometric techniques. Cases were patients who were diagnosed with
adenocarcinoma of the prostate from biopsy, and controls were patients who had no
evidence of cancer from biopsy. The odds ratio for detection of prostate cancer
was determined for hK2 measurements, controlling for age, total-PSA level,
digital rectal examination, and symptoms of urinary obstruction. RESULTS: Of 324
men, 159 (49.1%) had cancer. Mean hK2 levels and hK2:free-PSA ratios were
significantly higher in cases than in controls (1.18 v 0.53 ng/mL, respectively,
for hK2, P =.0001; 1.17 v 0.62 for hK2:free-PSA ratio, P =.0001). The crude odds
ratio for prostate cancer detection for patients in the highest quartile of hK2
level was 5.83 (95% confidence interval [CI], 2.8 to 12.1; P =.0001) compared
with patients in the lowest quartile. The adjusted odds ratio was 6.72 (95% CI,
2.9 to 15.6; P =.0001). Similarly, the crude and adjusted odds ratios for
prostate cancer detection using the hK2:free-PSA ratio were 7.36 (95% CI, 3.6 to
15.1; P =.0001) and 8.06 (95% CI, 3. 7 to 17.4; P =.0001), respectively. These
odds ratios were higher than that observed for prostate cancer detection by total
PSA level (2.73; P =.03). CONCLUSION: Among men prescreened with PSA for prostate
cancer, patients with high hK2 measurements have a five- to eight-fold increase
in risk for prostate cancer, adjusting for PSA level and other established risk
factors. hK2 measurements may be a useful adjunct to PSA in improving patient
selection for prostate biopsy.
PMID- 10694555
TI - Androgen deprivation and four courses of fixed-schedule suramin treatment in
patients with newly diagnosed metastatic prostate cancer: A Southwest Oncology
Group Study.
AB - PURPOSE: To assess the feasibility of administering a combination of suramin and
hydrocortisone in addition to androgen deprivation in a cooperative group
setting; to assess the feasibility of treatment with multiple courses of suramin;
and to assess progression-free and overall survival in patients with newly
diagnosed metastatic prostate cancer who underwent such treatment. PATIENTS AND
METHODS: Patients with newly diagnosed metastatic prostate cancer who had
adequate hematologic, hepatic, renal, neurologic, and coagulation parameters were
treated by combined androgen deprivation and suramin plus hydrocortisone. Suramin
was administered on a 78-day fixed dosing schedule (one cycle), and suramin
treatment cycles were repeated every 6 months for a total of four cycles. The
statistical design was developed on the basis of the feasibility of administering
suramin, as judged by the number of patients who developed neurotoxicity of grade
3 or higher or by treatment interruption of 4 weeks or longer due to any
persistent suramin-related toxicity. RESULTS: Of the 62 patients enrolled onto
the study between August 1994 and January 1997, 59 were eligible and assessable
for toxicity on the first cycle. Thirty-two (54%) of 59 patients received a
second cycle, 13 (22%) of 59 patients received a third cycle, and only five
patients (8%) received a fourth cycle. During the first cycle, 27 patients were
removed from the study: 17 because of toxicity, five because of disease
progression, two who had died, and three because of other reasons. There was one
therapy-related death. Grade 4 toxicities were noted in 11 and three patients
during first and second courses, respectively. Neurotoxicity of grade 3 or higher
was observed in nine and seven patients during the first and second cycles,
respectively. Fifteen patients had treatment interruptions of 4 weeks or longer.
Overall, only 54% (95% confidence interval, 41% to 67%) of the patients
demonstrated acceptable limits of toxicity. CONCLUSION: Suramin plus
hydrocortisone and androgen deprivation has limited applicability in the
treatment of patients with newly diagnosed metastatic prostate cancer.
PMID- 10694556
TI - Neoadjuvant chemotherapy and hormonal therapy followed by radical prostatectomy:
feasibility and preliminary results.
AB - PURPOSE: We assessed the feasibility and efficacy of integrating chemotherapy and
androgen ablation with radical prostatectomy in patients with locally advanced
prostate cancer. The neoadjuvant approach was adopted because it allows an in
situ assessment of antitumoral activity. PATIENTS AND METHODS: Thirty-three
patients were enrolled who met the clinical criteria of stage T1-2, Gleason score
of >/= 8 or T2b-T2c, Gleason score of 7 and prostate-specific antigen (PSA) level
greater than 10 ng/mL (n = 15), or clinical stage T3 (n = 18). Therapy consisted
of 12 weeks of ketoconazole and doxorubicin alternating with vinblastine,
estramustine, and androgen ablation followed by prostatectomy. The ability of
neoadjuvant chemotherapy and hormonal therapy to induce a 20% rate of pT0 in the
prostatectomy specimen as well as surgical feasibility were assessed. RESULTS:
Chemotherapy complications were comparable to those reported with this regimen
previously. No major intraoperative complications occurred. Postoperative
complications occurred in 10 (33%) of 30 patients. One patient died at home after
discharge (postoperative day 17; no autopsy was performed). Ten (33%) of the 30
patients had organ-confined disease, and 20 (70%) of 30 had extraprostatic
extension; 11 (37%) of the 30 had positive lymph nodes. Only five (17%) of 30
exhibited positive surgical margins. All patients achieved an undetectable PSA
level postoperatively, and 20 of the surviving 29 patients remain without disease
recurrence with a median follow-up of 13 months (range, 9 to 18 months).
CONCLUSION: Chemotherapy and androgen ablation followed by radical prostatectomy
was feasible in patients with locally advanced prostate cancer. Although the goal
of achieving a 20% rate for pT0 status was not achieved, we believe this type of
integrated therapeutic strategy should be investigated further for its ability to
alter the course of regionally advanced prostate cancer.
PMID- 10694557
TI - Phase II study of cisplatin and paclitaxel in advanced carcinoma of the
urothelium: an Eastern Cooperative Oncology Group Study.
AB - PURPOSE: Cisplatin and paclitaxel are active agents in advanced urothelial
cancer. A phase II trial of this combination was performed to determine the
activity and toxicity of these agents in a multi-institutional setting. PATIENTS
AND METHODS: Fifty-two patients with advanced urothelial carcinoma were treated
on one day with paclitaxel 175 mg/m(2) over 3 hours followed by cisplatin 75
mg/m(2), both intravenously, every 21 days. Cycles were repeated every 21 days
until progression or a maximum of six cycles. RESULTS: Twenty-six patients
obtained an objective response, for an overall response rate of 50% (95%
confidence interval, 36% to 64%). Four patients achieved complete clinical
responses. The median overall survival time for the group was 10.6 months.
Toxicity was moderate, with granulocytopenia and neurotoxicity being the most
common side effects noted. CONCLUSION: The combination of cisplatin and
paclitaxel is active in advanced urothelial cancer. Responses in visceral, nodal,
and soft tissues sites were observed. Granulocytopenia without fever and grade
2/3 neurotoxicity were common. The confidence interval of the overall response
rate in this study overlaps most of the other reported regimens. The optimal
therapy for advanced urothelial cancer remains undefined.
PMID- 10694558
TI - Topotecan has substantial antitumor activity as first-line salvage therapy in
platinum-sensitive epithelial ovarian carcinoma: A Gynecologic Oncology Group
Study.
AB - PURPOSE: Topotecan is known to be active in recurrent ovarian cancer, but most
prior studies have focused on platinum-resistant or refractory populations. This
study was undertaken to define the response rate and progression-free interval in
platinum-sensitive patients. PATIENTS AND METHODS: Patients with recurrent
ovarian cancer after one or two prior chemotherapy regimens and in whom the
interval between prior platinum therapy and the initiation of protocol therapy
was greater than 6 months were treated with topotecan 1.5 mg/m(2) intravenously
over 30 minutes daily for 5 days, with this cycle repeated every 21 days.
RESULTS: Forty-eight patients were entered onto the study; 47 were assessable for
toxicity and 46 for response. The response rate was 33% (two complete responses
and 13 partial responses), with a median response duration of 11.2 months.
Hematologic toxicity predominated but was manageable in most patients with
frequent incorporation of cytokines and RBC and platelet transfusions. Fatigue
was reported in 15 patients and resulted in the discontinuation of therapy in
five responding patients. CONCLUSION: Topotecan is an active drug in platinum
sensitive ovarian cancer, with significant but manageable hematologic toxicity.
Fatigue is also a common problem that may be dose-limiting in some patients.
PMID- 10694559
TI - Evaluation of soy phytoestrogens for the treatment of hot flashes in breast
cancer survivors: A North Central Cancer Treatment Group Trial.
AB - PURPOSE: Hot flashes represent a significant clinical problem for some breast
cancer survivors. Safe, effective treatment is needed for this prominent clinical
problem. Although it has been shown that estrogen or progesterone replacement
therapy can alleviate this problem, there are continued safety concerns regarding
the use of hormonal therapies in these women. Based on anecdotal information, we
hypothesized that soy-derived phytoestrogens, weak estrogen-like substances in
the soybean that demonstrate estrogen agonist and/or antagonist effects when they
bind to estrogen receptors, could alleviate hot flashes. This current trial was
designed to investigate this hypothesis. PATIENTS AND METHODS: This double-blind
clinical trial involved breast cancer survivors with substantial hot flashes.
After randomization, patients underwent a 1-week baseline period with no therapy.
This was followed by 4 weeks of either soy tablets or placebo. The patients then
crossed over to the opposite arm in a double-blind manner for the last 4 weeks.
Patients completed a daily questionnaire documenting hot flash frequency,
intensity, and perceived side effects. RESULTS: Of the 177 women who were
randomized and started the study substance, 155 (88%) provided useable data over
the first 5 weeks; 149 provided usable data over the entire 9 weeks. There was no
suggestion that the soy product was more effective in reducing hot flashes than
the placebo. At study completion, patients preferred the soy product 33% of the
time, the placebo 37% of the time, and neither substance 31% of the time. No
toxicity was observed. CONCLUSION: The soy product did not alleviate hot flashes
in breast cancer survivors.
PMID- 10694560
TI - High local recurrence risk after breast-conserving therapy in node-negative
premenopausal breast cancer patients is greatly reduced by one course of
perioperative chemotherapy: A European Organization for Research and Treatment of
Cancer Breast Cancer Cooperative Group Study.
AB - PURPOSE: Patients with invasive breast cancer may develop a local recurrence (LR)
after breast-conserving therapy (BCT). Younger age has been found to be an
independent risk factor for LR. Within a group of premenopausal node-negative
breast cancer patients, we studied risk factors for LR and the effect of
perioperative chemotherapy (PeCT) on LR. PATIENTS AND METHODS: The European
Organization for Research and Treatment of Cancer (EORTC) conducted a randomized
trial (EORTC 10854) to compare surgery followed by one course of PeCT
(fluorouracil, doxorubicin, and cyclophosphamide) with surgery alone. From
patients treated on this trial, we selected premenopausal patients with node
negative breast cancer who were treated with BCT to examine whether histologic
characteristics and the expression of various proteins (estrogen receptor,
progesterone receptor, p53, Ki-67, bcl-2, CD31, c-erbB-2/neu) are risk factors
for subsequent LR. Also, the effect of one course of PeCT on the LR risk (LRR)
was studied. RESULTS: Using multivariate analysis, age younger than 43 years
(relative risk [RR], 2.75; 95% confidence interval [CI], 1.46 to 5.18; P =.002),
multifocal growth (RR, 3.34; 95% CI, 1.27 to 8.77; P =.014), and elevated levels
of p53 (RR, 2. 14; 95% CI, 1.13 to 4.05; P =.02) were associated with higher LRR.
Also, PeCT was found to reduce LRR by more than 50% (RR, 0.47; 95% CI, 0.25 to
0.86; P =.02). Patients younger than 43 years who received PeCT achieved similar
LR rates as those of patients younger than 43 years who were treated with BCT
alone. CONCLUSION: In premenopausal node-negative patients, age younger than 43
years is the most important risk factor for LR after BCT; this risk is greatly
reduced by one course of PeCT. The main reason for administering systemic
adjuvant treatment is to improve overall survival. The important reduction of LR
after BCT is an additional reason for considering systemic treatment in young
node-negative patients with breast cancer.
PMID- 10694561
TI - Trauma history as a predictor of psychologic symptoms in women with breast
cancer.
AB - PURPOSE: To identify predictors of psychiatric problems in women with early-stage
breast cancer. PATIENTS AND METHODS: One hundred sixty women with early-stage
breast cancer were recruited from three treatment centers. They filled out self
report questionnaires, including a medical history and demographic survey, the
Trauma History Questionnaire, Life Event Questionnaire, Brief Symptom Inventory,
Beck Depression Inventory, and Duke-UNC Functional Social Support Questionnaire,
and were evaluated using the Structured Clinical Interview for DSM-III-R.
RESULTS: Hierarchical regression analyses indicated that four of five variable
sets made a significant incremental contribution to outcome prediction, with 35%
to 37% of the variance explained. Outcomes were predicted by demographic
variables, trauma history variables, precancer psychiatric diagnosis, recent life
events, and perceived social support. Cancer treatment variables did not predict
outcome. CONCLUSION: The findings highlight the important roles of trauma history
and recent life events in adjustment to cancer and have implications for
screening and treatment.
PMID- 10694562
TI - Long-term prognosis after resection of hepatocellular carcinoma associated with
hepatitis B-related cirrhosis.
AB - PURPOSE: The optimum management of hepatocellular carcinoma (HCC) associated with
cirrhosis has not yet been clarified. Very few data are available in the
literature regarding the prognosis after resection of HCC associated with
hepatitis B virus (HBV)-related cirrhosis. This study evaluated the long-term
results and prognostic factors after resection of HCC complicating HBV-related
cirrhosis. PATIENTS AND METHODS: One hundred forty-six patients with HBV-related
Child's A or B cirrhosis who had undergone resection of HCC over a 10-year period
were prospectively studied for long-term results. They were compared with 155
noncirrhotic patients with HBV-related HCC resected in the same period. RESULTS:
The overall survival results of cirrhotic patients after resection of HCC were
comparable to those of noncirrhotic patients (5-year survival, 44.3% v 45.6%,
respectively; P =.216), but the former group had significantly smaller tumors.
Stratified according to tumor size, the survival results were similar between
cirrhotic and noncirrhotic patients with tumors = 5 cm (5-year survival, 60.7%
v 61.7%, respectively; P =.327) but were worse in cirrhotic compared with
noncirrhotic patients with tumors greater than 5 cm (5-year survival, 27.8% v
39.5%, respectively; P =.034). Stage by stage, there were no significant
differences in survival results between cirrhotic and noncirrhotic patients.
Preoperative serum AST level greater than 100 IU/L (P =.004), perioperative
transfusion (P =.015), and venous invasion (P <.001) were independent adverse
prognostic factors. CONCLUSION: The prognosis after resection of HCCs less than 5
cm in patients with compensated HBV-related cirrhosis was comparable to that of
noncirrhotic patients, which suggests that surgical resection may be considered a
first-line treatment for these patients. Patients with underlying active
hepatitis as indicated by a high preoperative transaminase level are less
favorable candidates for resection. Further studies are needed to define the
relative roles of resection and transplantation for HCC associated with hepatitis
B cirrhosis.
PMID- 10694563
TI - Multi-institutional phase I/II trial of paclitaxel, cisplatin, and etoposide with
concurrent radiation for limited-stage small-cell lung carcinoma.
AB - PURPOSE: To determine the feasibility of adding paclitaxel to standard
cisplatin/etoposide (EP) and thoracic radiotherapy. PATIENTS AND METHODS: Thirty
one patients were enrolled onto this study. During the phase I section of this
study, the dose of paclitaxel was escalated in groups of three or more patients.
Cycles were repeated every 21 days. For cycles 1 and 2, paclitaxel was
administered according to the dose-escalation schema at doses of 100, 135, or 170
mg/m(2) intravenously over 3 hours on day 1. Once the maximum-tolerated dose
(MTD) of paclitaxel (for cycles 1 and 2, concurrent with radiation) was
determined, that dose was used in all subsequent patients entered onto the phase
II section of this study. For cycles 3 and 4, the paclitaxel dose was fixed at
170 mg/m(2) in all patients. On day 2, cisplatin 60 mg/m(2) was administered for
all cycles. On days 1, 2, and 3, etoposide 60 mg/m(2)/d (cycles 1 and 2) or 80
mg/m(2)/d (cycles 3 and 4) was administered. Chest radiation was given at 9 Gy/wk
in five fractions for 5 weeks beginning on day 1 of cycle 1. Granulocyte colony
stimulating factors were used during cycles 3 and 4 only. RESULTS: Twenty-eight
patients were assessable. The MTD of paclitaxel was 135 mg/m(2), with the dose
limiting toxicity being grade 4 neutropenia. Cycles 1 and 2 were associated with
grade 4 neutropenia in 32% of courses, with fever occurring in 7% of courses and
grade 2/3 esophagitis in 13%. Cycles 3 and 4 were complicated by grade 4
neutropenia in 20% of courses, with fever occurring in 6% of courses and grade
2/3 esophagitis in 16%. The overall response rate was 96% (complete responses,
39%; partial responses, 57%). After a median follow-up period of 23 months
(range, 9 to 40 months), the median survival time was 22.3 months (95% confidence
interval, 15.1 to 34.3 months) CONCLUSION: The MTD of paclitaxel with radiation
and EP treatment is 135 mg/m(2) given over 3 hours. In this schedule of
administration, a high response rate and acceptable toxicity can be anticipated.
PMID- 10694564
TI - Prospective analysis of Staphylococcus aureus bacteremia in nonneutropenic adults
with malignancy.
AB - PURPOSE: To determine the primary sources and secondary complications of
Staphylococcus aureus bacteremia (SAB) in cancer patients, as well as predictors
of outcome in cancer patients with SAB. PATIENTS AND METHODS: Fifty-two patients
at Duke University Medical Center met entry criteria between September 1994 and
December 1996 for this prospective cohort study involving hospitalized
nonneutropenic adult cancer patients with SAB. All subjects were observed
throughout initial hospitalization and were evaluated again at 6 and 12 weeks or
until death. RESULTS: SAB was intravascular device-related in 42%, tissue
infection-related (TIR) in 44%, and unidentifiable focus-related (UFR) in 13%.
Seventeen patients (33%) were found to have metastatic infections or conditions,
with eight (15%) developing infectious endocarditis (IE). Patients with TIR
bacteremia were less likely than other patients to develop IE (4% v 24%, P =.06).
The overall mortality rate was 38%, the SAB-related mortality rate was 15%, and
the rate of SAB relapse was 12%. Methicillin resistance was not associated with
adverse outcome. Inability to identify a point of entry (UFR bacteremia),
however, was associated with a higher overall mortality rate (100% v 24%, P
=.0006). Furthermore, a 72-hour surveillance blood culture positive for organisms
was associated with an increased incidence of IE (P =.0006), metastatic
infections or conditions (P =.0002), SAB relapse (P =.038), and SAB-related death
(P =.038). CONCLUSION: SAB in cancer patients is associated with significant
morbidity from frequent metastatic infections or conditions including IE, as well
as considerable mortality. Unknown initial infection site and 72-hour
surveillance cultures positive for organisms were predictive of a complicated
course and poor final outcome.
PMID- 10694565
TI - Phase I and pharmacokinetic study of irinotecan and docetaxel in patients with
advanced solid tumors: preliminary evidence of clinical activity.
AB - PURPOSE: The goals of this study were to determine the maximum-tolerated dose and
describe the toxicities of the combination of irinotecan and docetaxel
administered every 3 weeks to patients with advanced malignancies and, also, to
evaluate the effect of irinotecan on the disposition of docetaxel and describe
preliminary evidence of antitumor activity. PATIENTS AND METHODS: Eighteen
patients received 85 courses (median, two courses; range, one to 15 courses) of
treatment with irinotecan, administered over 90 minutes by intravenous infusion,
followed by docetaxel, administered over 60 minutes by intravenous infusion. Four
escalating dose levels of irinotecan/docetaxel (160/50 mg/m(2), 160/65 mg/m(2),
200/65 mg/m(2), and 200/75 mg/m(2)) were studied. Pharmacokinetic analyses were
performed to evaluate the effect of irinotecan on the disposition of docetaxel.
RESULTS: The most common and dose-limiting toxicity was myelosuppression, which
consisted of neutropenia that was severe (National Cancer Institute common
toxicity criteria [NCI CTC] grade 4) but brief (< 5 days) in 11 patients, with
three episodes of febrile neutropenia. Nonhematologic toxicities of anorexia,
nausea, and stomatitis were mild to moderate (NCI CTC grades 1 and 2), but there
was one incidence each of both CTC grade 3 anorexia and nausea. All patients had
total alopecia. Diarrhea was dose-dependent and severe in four patients who
failed to take adequate antidiarrhea therapy. Five out of 16 assessable patients,
one with cholangiocarcinoma, one with leiomyosarcoma, and three with non-small
cell lung cancer, achieved partial remissions. CONCLUSION: The combination of
irinotecan and docetaxel causes significant reversible myelosuppression, which
was dose limiting but led to no serious sequelae. There was no evidence of a
clinically significant interaction using these two agents in this sequence. The
combination showed antitumor activity at all the dose levels tested and should be
further studied in a number of tumor types. The recommended phase II dose on this
schedule is irinotecan 160 mg/m(2) and docetaxel 65 mg/m(2).
PMID- 10694566
TI - Phase I study of paclitaxel in combination with a multidrug resistance modulator,
PSC 833 (Valspodar), in refractory malignancies.
AB - PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicity
(DLT), and pharmacokinetics of paclitaxel when given with PSC 833 (valspodar) to
patients with refractory solid tumors. PATIENTS AND METHODS: Patients were
initially treated with paclitaxel 175 mg/m(2) continuous intravenous infusion
(CIVI) over 3 hours. Subsequently, 29 hours of treatment with CIVI PSC 833 was
started 2 hours before paclitaxel treatment was initiated. In this combination,
the starting dose of paclitaxel was 52.5 mg/m(2). Paclitaxel doses were escalated
by 17.5 mg/m(2) increments for four subsequent cohorts. Each cohort consisted of
three patients with the exception of the last cohort, which consisted of six
patients. Data for the pharmacokinetics of paclitaxel with and without concurrent
PSC 833 administration were obtained. RESULTS: All 18 patients completed at least
one course of concurrent treatment (median, two courses; range, one to six) and
were evaluable for toxicity. The MTD for paclitaxel with PSC 833 was 122.5
mg/m(2). Neutropenia was the DLT. All patients had PSC 833 blood concentrations
greater than 1, 000 ng/mL before, during, and 24 hours after the paclitaxel
infusion. PSC 833 produced small increases in the paclitaxel peak plasma
concentrations and areas under the concentration-time curve. However, PSC 833
greatly prolonged the terminal phase of paclitaxel, resulting in plasma
paclitaxel concentrations of more than 0.05 micromol/L for much longer than
expected. As a result, myelosuppression was comparable to that produced by full
dose paclitaxel given without PSC 833. Of the 16 patients who were assessable for
response, one patient experienced a partial response and an additional nine
patients experienced disease stabilization after paclitaxel treatment alone.
CONCLUSION: Treatment with paclitaxel 122.5 mg/m(2) as a 3-hour CIVI concurrent
with a 29-hour CIVI of PSC 833 results in acceptable toxicity. The addition of
PSC 833 alters the pharmacokinetics of paclitaxel, which explains the enhanced
neutropenia experienced by patients treated with this drug combination.
PMID- 10694567
TI - Matrix metalloproteinases: biologic activity and clinical implications.
AB - Tumor progression is a complex, multistage process by which a normal cell
undergoes genetic changes that result in phenotypic alterations and the
acquisition of the ability to spread and colonize distant sites in the body.
Although many factors regulate malignant tumor growth and spread, interactions
between a tumor and its surrounding microenvironment result in the production of
important protein products that are crucial to each step of tumor progression.
The matrix metalloproteinases (MMPs) are a family of degradative enzymes with
clear links to malignancy. These enzymes are associated with tumor cell invasion
of the basement membrane and stroma, blood vessel penetration, and metastasis.
They have more recently been implicated in primary and metastatic tumor growth
and angiogenesis, and they may even have a role in tumor promotion. This review
outlines our current understanding of the MMP family, including the association
of particular MMPs with malignant phenotypes and the role of MMPs in specific
steps of the metastatic cascade. As scientific understanding of the MMPs has
advanced, therapeutic strategies that capitalize on blocking the enzymes have
rapidly developed. The preclinical and clinical evolution of the synthetic MMP
inhibitors (MMPIs) is also examined, with the discussion encompassing important
methodologic issues associated with determining clinical efficacy of MMPIs and
other novel therapeutic agents.
PMID- 10694568
TI - Case 1. Hodgkins's disease presenting as a cystic neck mass.
PMID- 10694569
TI - Meningeal relapse in Hodgkin's disease.
PMID- 10694570
TI - To hydrate or not to hydrate: how should it be?
PMID- 10694571
TI - BRCA1/2 germline mutations: a marker for radioresistance or radiosensitivity?
PMID- 10694573
TI - Widanelfarasia, a diminutive placental from the late Eocene of Egypt.
AB - The lower dentition of Widanelfarasia (new genus), a diminutive late Eocene
placental from the Fayum Depression in Egypt, is described. Widanelfarasia
exhibits a complex of features associated with incipient zalambdodonty and at
least three unequivocal apomorphies [loss of P(1), an enlarged I(2) (relative to
I(3)), and a basal cusp on I(2)], which provide weak support for its placement as
a possible sister taxon of either a tenrecid-chrysochlorid clade or of
solenodontids. The former hypothesis gains additional support from
biogeographical evidence, but both scenarios are currently tenuous as
Widanelfarasia is clearly not truly zalambdodont. Phylogenetic hypotheses
positing affinities with tenrecids alone or chrysochlorids alone must invoke
either convergent acquisition of zalambdodonty in these taxa or autapomorphic
reversal in Widanelfarasia. Given these considerations, a relationship with more
generalized taxa from the Laurasian Paleogene (e.g., geolabidids, nyctitheriids,
leptictids) cannot yet be ruled out. Comparisons with other Paleogene Afro
Arabian forms are generally inconclusive. A relationship with the earlier Eocene
Chambilestes from Tunisia-currently represented by a single specimen preserving
P(4)-M(3)-seems possible based on the geometry and predicted occlusal
relationships of these teeth, but cannot be confidently determined until these
two taxa come to be represented by common diagnostic elements. Todralestes (late
Paleocene, Morocco) exhibits general phenetic similarities to Widanelfarasia, but
it is not yet known whether this taxon shares any of Widanelfarasia's unequivocal
dental apomorphies. Pending the recovery of more informative material, we
tentatively refer Widanelfarasia to Placentalia incertae sedis. Truly
zalambdodont placentals remain conspicuously absent from the Paleogene of Afro
Arabia.
PMID- 10694572
TI - Copper chaperone for superoxide dismutase is essential to activate mammalian
Cu/Zn superoxide dismutase.
AB - Recent studies in Saccharomyces cerevisiae suggest that the delivery of copper to
Cu/Zn superoxide dismutase (SOD1) is mediated by a cytosolic protein termed the
copper chaperone for superoxide dismutase (CCS). To determine the role of CCS in
mammalian copper homeostasis, we generated mice with targeted disruption of CCS
alleles (CCS(-/-) mice). Although CCS(-/-) mice are viable and possess normal
levels of SOD1 protein, they reveal marked reductions in SOD1 activity when
compared with control littermates. Metabolic labeling with (64)Cu demonstrated
that the reduction of SOD1 activity in CCS(-/-) mice is the direct result of
impaired Cu incorporation into SOD1 and that this effect was specific because no
abnormalities were observed in Cu uptake, distribution, or incorporation into
other cuproenzymes. Consistent with this loss of SOD1 activity, CCS(-/-) mice
showed increased sensitivity to paraquat and reduced female fertility, phenotypes
that are characteristic of SOD1-deficient mice. These results demonstrate the
essential role of any mammalian copper chaperone and have important implications
for the development of novel therapeutic strategies in familial amyotrophic
lateral sclerosis.
PMID- 10694574
TI - Biosynthesis of terpenoids: YgbB protein converts 4-diphosphocytidyl-2C-methyl-D
erythritol 2-phosphate to 2C-methyl-D-erythritol 2,4-cyclodiphosphate.
AB - In many microorganisms, the putative orthologs of the Escherichia coli ygbB gene
are tightly linked or fused to putative orthologs of ygbP, which has been shown
earlier to be involved in terpenoid biosynthesis. The ygbB gene of E. coli was
expressed in a recombinant E. coli strain and was shown to direct the synthesis
of a soluble, 17-kDa polypeptide. The recombinant protein was found to convert 4
diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate into 2C-methyl-D-erythritol
2,4-cyclodiphosphate and CMP. The structure of the reaction product was
established by NMR spectroscopy using (13)C-labeled substrate samples. The enzyme
catalyzed reaction requires Mn(2+) or Mg(2+) but no other cofactors.
Radioactivity from [2-(14)C]2C-methyl-D-erythritol 2,4-cyclodiphosphate was
diverted efficiently to carotenoids by isolated chromoplasts from Capsicum annuum
and, thus, was established as an intermediate in the deoxyxylulose phosphate
pathway of isoprenoid biosynthesis. YgbB protein also was found to convert 4
diphosphocytidyl-2C-methyl-D-erythritol into 2C-methyl-D-erythritol 3,4
cyclophosphate. This compound does not serve as substrate for the formation of
carotenoids by isolated chromoplasts and is assumed to be an in vitro product
without metabolic relevance.
PMID- 10694575
TI - Postexposure vaccination massively increases the prevalence of gamma-herpesvirus
specific CD8+ T cells but confers minimal survival advantage on CD4-deficient
mice.
AB - Mice that lack CD4(+) T cells remain clinically normal for more than 60 days
after respiratory challenge with the murine gamma-herpesvirus 68 (gammaHV-68),
then develop symptoms of a progressive wasting disease. The gammaHV-68-specific
CD8(+) T cells that persist in these I-A(b-/-) mice are unable to prevent
continued, but relatively low level, virus replication. Postexposure challenge
with recombinant vaccinia viruses expressing gammaHV-68 lytic cycle epitopes
massively increased the magnitude of the gammaHV-68-specific CD8(+) population
detectable by staining with tetrameric complexes of MHC class I glycoprotein +
peptide, or by interferon-gamma production subsequent to in vitro restimulation
with peptide. The boosting effect was comparable for gammaHV-68-infected I-A(b-/
) and I-A(b+/+) mice within 7 days of challenge, and took more than 110 days to
return to prevaccination levels in the I-A(b+/+) controls. Although the life-span
of the I-A(b-/-) mice was significantly increased, there was no effect on long
term survival. A further boost with a recombinant influenza A virus failed to
improve the situation. Onset of weight loss was associated with a decline in
gammaHV-68-specific CD8(+) T cell numbers, though it is not clear whether this
was a cause or an effect of the underlying pathology. Even very high levels of
virus-specific CD8(+) T cells thus provide only transient protection against the
uniformly lethal consequences of gammaHV-68 infection under conditions of CD4(+)
T cell deficiency.
PMID- 10694576
TI - Estrogen up-regulates Bcl-2 and blocks tolerance induction of naive B cells.
AB - Sex hormones are presumed to contribute to sexual dimorphism in the immune
system. Estrogen, in particular, has been suggested to predispose women to
systemic lupus erythematosus. We report here that estradiol (E(2)) can break B
cell tolerance and induce a lupus-like phenotype in nonautoimmune mice transgenic
for the heavy chain of a pathogenic anti-DNA antibody. E(2) treatment resulted in
a rise in anti-DNA serum titers and in Ig deposition in renal glomeruli. ELISPOT
analysis confirmed a significant increase in the number of high-affinity anti-DNA
antibody-secreting B cells in the spleens of E(2)-treated mice. Hybridomas
generated from E(2)-treated mice express high-affinity, unmutated anti-DNA
antibodies, indicating that naive B cells that are normally deleted or anergized
are rescued from tolerance induction. Finally, immunohistochemical studies
revealed increased Bcl-2 expression in splenic B cells of E(2)-treated mice.
These data demonstrate that estrogen interferes with tolerance induction of naive
autoreactive B cells and that the presence of these B cells in the periphery is
associated with up-regulation of Bcl-2.
PMID- 10694577
TI - Apolipoprotein E isoform-dependent amyloid deposition and neuritic degeneration
in a mouse model of Alzheimer's disease.
AB - Apolipoprotein E (apoE) alleles determine the age-adjusted relative risk
(epsilon4 > epsilon3) for Alzheimer's disease (AD). ApoE may affect AD
pathogenesis by promoting deposition of the amyloid-beta (Abeta) peptide and its
conversion to a fibrillar form. To determine the effect of apoE on Abeta
deposition and AD pathology, we compared APP(V717F) transgenic (TG) mice
expressing mouse, human, or no apoE (apoE(-/-)). A severe, plaque-associated
neuritic dystrophy developed in APP(V717F) TG mice expressing mouse or human
apoE. Though significant levels of Abeta deposition also occurred in APP(V717F)
TG, apoE(-/-) mice, neuritic degeneration was virtually absent. Expression of
apoE3 and apoE4 in APP(V717F) TG, apoE(-/-) mice resulted in fibrillar Abeta
deposits and neuritic plaques by 15 months of age and substantially (>10-fold)
more fibrillar deposits were observed in apoE4-expressing APP(V717F) TG mice. Our
data demonstrate a critical and isoform-specific role for apoE in neuritic plaque
formation, a pathological hallmark of AD.
PMID- 10694578
TI - HLA B*5701 is highly associated with restriction of virus replication in a
subgroup of HIV-infected long term nonprogressors.
AB - A unique cohort of HIV-1-infected long term nonprogressors (LTNP) with normal
CD4(+) T cell counts and <50 copies/ml of plasma were prospectively recruited for
study. HLA typing revealed a dramatic association between the HLA B*5701 class I
allele and nonprogressive infection [85% (11 of 13) vs. 9.5% (19 of 200) in
progressors; P < 0. 001]. Antigen-specific CD8(+) T cells were enumerated by flow
cytometric detection of intracellular IFN-gamma in response to HIV antigens and
HLA B*57-gag tetramer staining. No quantitative differences in the total HIV
specific CD8(+) T cell responses were observed between B*57(+) LTNP and five
B*57(+) progressors (P = 0.4). Although similar frequencies of peptide specific
CD8(+) T cells were also found, the gag-specific CD8(+) T cell response in the
LTNP group was highly focused on peptides previously shown to be B*57-restricted.
These findings indicate that, within this phenotypically and genotypically
distinct cohort, a host immune factor is highly associated with restriction of
virus replication and nonprogressive disease. They also strongly suggest a
mechanism of virus specific immunity that directly operates through the B*5701
molecule. Further characterization of qualitative differences in the virus
specific responses that distinguish HLA B*57(+) LTNP from progressors may
ultimately define mechanisms of effective immune mediated restriction of virus
replication.
PMID- 10694579
TI - The interaction of nitric oxide (NO) with the yeast transcription factor Ace1: A
model system for NO-protein thiol interactions with implications to metal
metabolism.
AB - Nitric oxide (NO) was found to inhibit the copper-dependent induction of the
yeast CUP1 gene. This effect is attributable to an inhibition of the copper
responsive CUP1 transcriptional activator Ace1. A mechanism is proposed whereby
the metal binding thiols of Ace1 are chemically modified via NO- and O(2)
dependent chemistry, thereby diminishing the ability of Ace1 to bind and respond
to copper. Moreover, it is proposed that demetallated Ace1 is proteolytically
degraded in the cell, resulting in a prolonged inhibition of copper-dependent
CUP1 induction. These findings indicate that NO may serve as a disrupter of yeast
copper metabolism. More importantly, considering the similarity of Ace1 to other
mammalian metal-binding proteins, this work lends support to the hypothesis that
NO may regulate/disrupt metal homeostasis under both normal physiological and
pathophysiological circumstances.
PMID- 10694581
TI - Springtime of hope.
PMID- 10694580
TI - In vivo natural killer cell activities revealed by natural killer cell-deficient
mice.
AB - Studies of natural killer (NK) cell function in vivo have been challenging
primarily due to the lack of animal models in which NK cells are genetically and
selectively deficient. Here, we describe a transgenic mouse with defective
natural killing and selective deficiency in NK1.1(+) CD3(-) cells. Despite
functionally normal B, T, and NK/T cells, transgenic mice displayed impaired
acute in vivo rejection of tumor cells. Adoptive transfer experiments confirmed
that NK1.1(+) CD3(-) cells were responsible for acute tumor rejection,
establishing the relationship of NK1.1(+) CD3(-) cells to NK cells. Additional
studies provided evidence that (i) NK cells play an important role in suppressing
tumor metastasis and outgrowth; (ii) NK cells are major producers of IFNgamma in
response to bacterial endotoxin but not to interleukin-12, and; (iii) NK cells
are not essential for humoral responses to T cell-independent type 2 antigen or
the generalized Shwartzman reaction, both of which were previously proposed to
involve NK cells.
PMID- 10694583
TI - Ocean tides.
PMID- 10694582
TI - The threat of stress to the heart health of Canadians: results of the Foundation
health survey.
PMID- 10694584
TI - Hypertrophic cardiomyopathy in pediatric patients: effect of verapamil on
regional and global left ventricular diastolic function.
AB - OBJECTIVE: To assess the effects of treatment with verapamil on regional and
global left ventricular (LV) diastolic function in paediatric patients with
hypertrophic cardiomyopathy (HCM). DESIGN: Twelve patients (age range 5.1 to 12.3
years, median 8.6) with HCM were evaluated during ongoing chronic oral treatment
with verapamil (4 mg/kg/day) and four days after withdrawal of therapy. Twelve
age- and body surface area-matched normal children served as controls. In an
echocardiographic study, global LV diastolic function was evaluated by assessing
isovolumic relaxation time (IVRT) and mitral flow indexes, including peak filling
rate normalized to mitral stroke volume (PFR/SV). In addition, regional LV
diastolic function was assessed by pulsed-wave Doppler tissue imaging at the
subendocardial portion of the middle region of the anterior and posterior
interventricular septum, and anterolateral and inferior walls to measure the peak
velocities and the velocity-time integrals of myocardial excursion in both early
diastole and atrial systole. In addition, as an index of diastolic asynchrony
(AsyI), the variation in time to peak filling rate, measured as the time from the
peak of the R wave on the electrocardiogram to the peak of the regional E wave,
among the four myocardial regions was defined by subtracting the smallest value
from the greatest and expressing the difference as a percentage of the smallest
value. RESULTS: Compared with the controls, patients with HCM without therapy
showed a longer IVRT (P<0.01) and a decrease in PFR/SV (P<0.01) without a
compensatory increase in filling during atrial systole. Oral administration of
verapamil induced a significant shortening of the IVRT (P=0.003) and an increase
in PFR/SV (P=0.02). Furthermore, patients with HCM without therapy showed a
significantly longer time to peak filling rate (P<0.01) associated with a
decreased peak velocity in early diastole without a concomitant increase in peak
velocity during atrial systole in each of the myocardial regions. Furthermore,
the AsyI was higher in the HCM group than in controls (19% versus 6%,
respectively), and this index was inversely correlated with the PFR/SV (r=-0.86,
P<0.001). The regional diastolic velocity of the myocardium at each of the four
analyzed regions was not significantly different with verapamil, but the AsyI was
significantly lower (P<0.05). CONCLUSIONS: Children with HCM show abnormalities
of both global and regional LV diastolic function. In these patients, chronic
administration of verapamil plays a crucial role in the improvement in global LV
filling and, as a consequence, in clinical manifestations. The beneficial effects
of verapamil seem to be related to a reduction in diastolic asynchrony more than
to significant changes in diastolic velocities of the myocardial fibres.
PMID- 10694585
TI - Oral anticoagulant therapy for heart disease: results in actual cardiology
practice.
AB - OBJECTIVE: To determine whether the success and complication rates of oral
anticoagulation obtained in large, well controlled trials, upon which
recommendations are based, are comparable with routine cardiology practice.
DESIGN: An observational, prospective cohort study collected data on all patients
followed at an anticoagulant clinic over one calendar year. PATIENTS: One
thousand and seventy-eight patients anticoagulated for cardiovascular
indications, mainly atrial fibrillation, prosthetic valves and ventricular
dysfunction, were followed for 804 patient-years of treatment. No patient was
lost to follow-up. INTERVENTIONS: Telephone conversations and regular
verification of medical files were used to record and classify all bleeding and
thromboembolic events according to severity. International normalized ratios
(INR) were compared with target ranges. RESULTS: One hundred and twelve bleeding
events, ie, 13.9/100 patient-years (% p-y), were recorded, of which 61 required
medical attention. Major hemorrhages, defined as those requiring treatment or
hospital observation for more than 24 h, occurred in 15 instances (1.9% p-y).
Among these, 9 (1.1% p-y) were classified as life threatening, with four being
fatal (0,5% p-y). Twenty-two thromboembolic events (2.7% p-y) occurred, of which
10 were major (1.2% p-y), leaving three patients (0.4% p-y) with long term
sequelae and causing two deaths (0.25% p-y). INRs were within target range 62.3%
of the time, with 2.2% of values recorded above 5 and 0.3% above 10. CONCLUSION:
The low failure and complication rates obtained in large, controlled trials are
similar to those observed in actual cardiology practice.
PMID- 10694586
TI - [Myocardial infarction with normal or near normal coronary arteries: late outcome
of seven patients].
AB - Myocardial infarction with normal or near normal coronary arteries: Late outcome
of seven patients Myocardial infarction with normal or near normal coronary
arteries probably results from thrombotic occlusion that is followed by lysis and
recanalization; in about a third of affected patients, coronary spasm appears to
be the trigger. The clinical profile of this syndrome is well known: patients are
young and without coronary risk factors except cigarette smoking, and they have
no angina before or after their infarction. However, the late prognosis remains
controversial. Between December 1976 and April 1984, myocardial infarction with
normal or near normal coronary arteries was diagnosed in seven patients who were
subsequently followed for a mean of 19 years. Observations during this follow-up
show that the majority of patients experienced one or more recurrences that, in
three cases, initiated the development of a severe ischemic cardiomyopathy.
PMID- 10694587
TI - Double-chambered right ventricle in 73 patients: spectrum of the disease and
surgical results of transatrial repair.
AB - OBJECTIVE: To review the spectrum of double-chambered right ventricle (DCRV) and
the outcome of surgical repair in patients diagnosed between February 1988 and
March 1999. DESIGN: The charts of patients with DCRV were studied. SETTING:
Tertiary care hospital. PATIENTS AND METHODS: A total of 73 patients were
identified. Sixty-nine underwent surgical repair, while four are awaiting
surgery. The repair was through a transatrial approach in 61 patients, while in
eight an additional ventriculotomy was performed. MAIN RESULTS: An associated
ventricular septal defect (VSD) was present in 56 of 73 patients (77%). These
patients were significantly younger (P<0.05) than the 17 patients without a VSD.
Among patients with a VSD, the 31 requiring patch closure were significantly
younger than the 25 patients having direct closure. Five older patients among
those with intact septum had impaired right ventricular (RV) function as well as
higher intraventricular gradients. At surgery the intraventricular obstruction
was relieved by myomectomy. There was no hospital or late mortality. Following
surgery, at a mean follow-up of 13.6 months, no increase in the intraventricular
gradient was detected by Doppler echocardiography. CONCLUSIONS: The development
of DCRV is associated with VSD in early life. The probability of the presence of
a VSD decreases with age. The disease is progressive, resulting in increased
intracavitary gradient within the RV and in RV impairment if it is not treated in
a timely fashion. Transatrial repair is safe with excellent midterm results. In
the presence of high gradients within the RV, a ventriculotomy may be necessary
to obtain acceptable results.
PMID- 10694588
TI - Body surface mapping of retrograde P waves in the intact dog by simulation of
accessory pathway re-entry.
AB - OBJECTIVES: To investigate a noninvasive technique to localize the atrial
insertion site of concealed accessory pathways based on the analysis of body
surface potential maps (BSPMs) of retrograde P waves in dogs with simulated
retrograde pathways. ANIMALS AND METHODS: Orthodromic tachycardias were simulated
by atrial stimulations at eight different sites around the atrioventricular ring
with long (250 ms and 300 ms) and short (100 ms and 130 ms) coupling times in 14
anesthetized dogs to have P waves well separated from the T wave or occurring
during the T wave, respectively. The distance between pacing sites was 15 to 40
mm in group 1 (eight dogs) and 2 mm (in the right atrial free wall region) in
group 2 (six dogs). Beats were signal-averaged during 30 s and BSPMs were
constructed from 63 unipolar leads. RESULTS: The P wave BSPM pattern for any
specific stimulation site was stable and reproducible (correlation coefficient
greater than 0.98), and similar in different dogs at long coupling interval
stimulations. The thoracic distribution of negative potentials and position of
the potential minimum clearly identified the stimulation site when long coupling
time stimulations were used. The spatial resolution of the technique as
determined by comparison of correlation coefficients in group 2 was 6 mm
(P<0.05). When short coupling time stimulations were used (fast tachycardia
simulation), the T wave masked the P wave potential distribution in four of eight
dogs, but the retrograde P wave map could still be accurately extracted by
subtracting a straight line joining the onset and offset of the P wave in 24 of
28 (86%) of the tachycardia simulation sites in these four dogs. CONCLUSIONS: The
BSPM patterns of simulated retrograde P waves are specifically related to the
site of atrial stimulation. Although the T wave altered these BSPM patterns, a
subtraction technique recovered the pattern of the retrograde P wave in 93% of
all simulated orthodromic tachycardias. The spatial resolution of the retrograde
P wave BSPM method was 6 mm.
PMID- 10694589
TI - Infusion of an antialpha4 integrin antibody is associated with less
neoadventitial formation after balloon injury of porcine coronary arteries.
AB - BACKGROUND: The alpha4beta1 (or very late antigen-4 [VLA-4]) integrin is thought
to play a role in inflammatory processes, mediating mononuclear leukocyte
infiltration. The adventitial response to balloon injury is an important
determinant of neointimal formation and arterial remodelling. OBJECTIVES: To
determine whether the monoclonal antibody hHP1/2 directed against the human
alpha4-integrin subunit decreases neoadventitial formation and subsequent luminal
narrowing following balloon injury. DESIGN: Randomized, double-blind, placebo
controlled study. SETTING: Tertiary care, Canadian university hospital vascular
biology laboratory. ANIMALS AND METHODS: In 16 pigs, two coronary arteries were
injured with an oversized balloon, while a third coronary artery was designated
as an uninjured control vessel. One hour before balloon injury, 5 mg/kg of hHP1/2
was administered to eight animals, while another eight animals received an
infusion of a saline placebo. Animals were killed three and 14 days following
balloon injury. MAIN RESULTS: Administration of hHP1/2 resulted in an immediate
decrease in circulating monocyte and lymphocyte counts. These parameters returned
to normal within three days. There was a decrease in neoadventitial formation 14
days after arterial injury in pigs treated with hHP1/2 compared with controls
(2.26+/-0.77 versus 3.42+/-1.01 mm, respectively, P=0.04). There was a loss of
lumen area between days 3 (4.33+/-1.09 mm2) and 14 (3.09+/-0.38 mm2, P=0.02)
after balloon injury in pigs treated with saline, but not in the pigs treated
with hHP1/2. CONCLUSIONS: Administration of an antibody to the alpha4-integrin
subunit is associated with less neoadventitial formation and less lumenal
narrowing after balloon injury. This novel therapy may play an important role in
modulating arterial remodelling and thereby may reduce restenosis following
percutaneous coronary interventions in humans.
PMID- 10694590
TI - Cardiac angiosarcoma: two cases and a review of the literature.
AB - BACKGROUND: Primary cardiac tumours are rare, and primary malignant cardiac
tumours even rarer. Of these, cardiac angiosarcomas are uncommon and, until
recently, almost invariably diagnosed at the time of autopsy, primarily because
the symptoms are initially nonspecific and do not become manifest until the
tumour is advanced. METHODS: Two patients, who presented in quite different
manners and were diagnosed at autopsy and at open surgical biopsy, are presented.
The literature on cardiac angiosarcomas is reviewed critically, with emphasis on
presentation and morphology. RESULTS: This review of the literature shows that,
with increasing availability of newer diagnostic tools, especially noninvasive
ones, diagnosis of this rare lesion can be made at an early stage and confirmed
at cardiac biopsy or cardiac surgery. Unfortunately, so far, the results remain
virtually uniformly poor, though occasionally survival at up to 53 months has
been reported.
PMID- 10694591
TI - Fatal myocardial embolus after myectomy.
AB - Coronary embolism is an infrequent phenomenon. A 56-year-old man with
hypertrophic obstructive cardiomyopathy and severe mitral regurgitation who
underwent left ventricular septal myectomy and mitral valve annular repair is
presented. The patient had a cardiac arrest 36 h after surgery. Cardiac
standstill, tamponade and a left ventricular rupture were noted when the chest
was opened during attempted resuscitation. Autopsy revealed an occlusive embolus
of myocardium in the proximal left anterior descending coronary artery. It showed
pathological features of hypertrophic cardiomyopathy. There was an extensive
acute transmural anteroseptal left ventricular myocardial infarction with rupture
of the anterior free wall. Embolism of myocardium - to the coronary arteries, the
systemic circulation or the pulmonary circulation - is a rare event, with only
nine other cases reported in the literature in the past 30 years. This is the
first reported case of myocardial embolus to a coronary artery in a patient with
hypertrophic obstructive cardiomyopathy following septal myectomy.
PMID- 10694592
TI - An unusual case of ST elevation in a 39-year-old man.
AB - A 39-year-old man presented to a university hospital emergency department with
anginal chest pain, ventricular tachycardia and ST elevation in the anterolateral
leads (V3 to V6, I and aVL). Due to discrepancies in the history and physical
examination, thrombolysis was withheld until a past electrocardiogram could be
obtained, which was unchanged. Subsequent investigations revealed no evidence of
myocardial necrosis, and the patient was diagnosed with hypertrophic
cardiomyopathy. This is the first reported case of hypertrophic cardiomyopathy
with ST elevation as the predominant electrocardiographic abnormality. In
patients with discrepancies in the clinical presentation, it is essential to
obtain past elecrocardiograms to ensure appropriate utility of thrombolysis.
PMID- 10694593
TI - Sirolimus, a new potent immunosuppressant agent for refractory cardiac
transplantation rejection: two case reports.
AB - Rejection remains a major cause of both early and late morbidity and mortality
following heart transplantation despite major advances in immunosuppressive
therapy. A major hurdle in the successful management of patients who have
undergone heart transplantation is preventing and treating graft rejection.
Cyclosporine, mycophenolate mofetil, azathioprine, tacrolimus (FK506) and OKT3
are well documented, effective immunosuppressive medications that prevent and
treat acute or chronic rejection following heart transplantation. One of the
macrolide antibiotics, sirolimus, is known to have immunosuppressant activity. In
two patients with chronic rejection of cardiac grafts refractory to usual
antirejection medications, sirolimus was successfully used to suppress graft
rejection. Both patients continued to be rejection free after 10 months of
sirolimus treatment despite significant decreases in doses of other
immunosuppressants.
PMID- 10694594
TI - The World Heart Federation's white book: impending global pandemic of
cardiovascular diseases: challenges and opportunities for the prevention and
control of cardiovascular diseases in developing countries and economies in
transition.
PMID- 10694596
TI - Donald l. Paulson (1912-1999)
PMID- 10694597
TI - Editorial foreword
PMID- 10694595
TI - Cardiovascular disease and the global village.
PMID- 10694598
TI - The core of leadership.
PMID- 10694599
TI - Chest wall resection for locally recurrent breast cancer: is it worthwhile?
AB - OBJECTIVE: The effectiveness of chest wall resection for locally recurrent breast
cancer as cancer treatment remains poorly defined, possibly because of the
general impression that locally recurrent disease is a harbinger of rapidly
progressive metastatic disease and that extensive surgical treatment in these
patients is inappropriate. Reports to date have focused on technical feasibility,
not long-term outcome. METHODS: We reviewed our experience with 38 women who
underwent chest wall resection for locally recurrent breast cancer between
October 1987 and May 1997. Overall survival was calculated by the Kaplan-Meier
method and the significance of prognostic variables evaluated by log-rank and Cox
regression analyses. RESULTS: The operative mortality rate was 0%. Overall
survival at 1, 3, and 5 years after chest wall resection was 74%, 41%, and 18%,
respectively, and the proportion of patients free of local recurrence at 1, 3,
and 5 years was 59%, 42%, and 13%, respectively. Regional nodal disease and size
of largest tumor nodule (>4 cm) were significant predictors of local re
recurrence (P <.01, P =.04); lymph node metastasis was the only predictor of long
term survival (P <.01). Patients with and without synchronous sites of metastatic
disease had near-identical 3-year survivals. CONCLUSIONS: Chest wall resection
for locally recurrent breast cancer has a low mortality. However, a significant
number of patients have the development of local re-recurrence or metastases, and
5-year survival is limited. It is unlikely that complete resection of all locally
recurrent disease improves survival. Future studies should focus on the quality
of palliation achieved.
PMID- 10694600
TI - Induction chemotherapy before surgery for early-stage lung cancer: A novel
approach. Bimodality Lung Oncology Team.
AB - OBJECTIVE: This phase II trial assessed the feasibility, as measured by response
rate, toxicity, resectability rate, and surgical morbidity and mortality rates,
of perioperative paclitaxel and carboplatin chemotherapy in patients with early
stage non-small cell lung carcinoma. METHODS: All patients required negative
mediastinoscopy results and adequate medical parameters to undergo induction
chemotherapy and an operation. Superior sulcus patients were excluded.
Chemotherapy consisted of paclitaxel 225 mg/m(2) over 3 hours and carboplatin
(area under the curve = 6) every 21 days for 2 cycles preoperatively. Three
postoperative cycles of chemotherapy were planned for patients undergoing
complete resection. RESULTS: Between June 1996 and July 1998, 94 patients were
entered into the study. Sixty-five (69%) were men, and the median age was 64
years (range, 34-79 years). After induction chemotherapy, 53 of 94 (56%; 95%
confidence interval, 46%-67%) had a major objective response, 88 (94%) underwent
surgical exploration, and 81 (86%; 95% confidence interval, 78%-92%) underwent
complete resection. Reasons for not undergoing an operation included disease
progression (n = 3), clinically unresectable status (n = 1), death (n = 1), and
patient lost to follow-up (n = 1). Two postoperative deaths occurred. Six (6%;
95% confidence interval, 0%-13%) pathologic complete responses were observed.
Ninety (96%) patients received the planned preoperative chemotherapy versus 45%
receiving postoperative chemotherapy. No unexpected chemotherapy or surgical
morbidity occurred. The 1-year survival is currently estimated at 85%, and the
median survival has not yet been reached. CONCLUSIONS: Induction chemotherapy
with paclitaxel and carboplatin is feasible and produces a high response rate
with acceptable morbidity and mortality rates in early-stage non-small cell lung
carcinoma. A prospective randomized trial comparing 3 cycles of induction
chemotherapy and surgery with surgery alone in early-stage non-small cell lung
carcinoma is planned.
PMID- 10694601
TI - Does pneumonectomy for lung cancer adversely influence long-term survival?
AB - OBJECTIVE: The increased operative mortality associated with pneumonectomy has
stimulated the use of lung-sparing operations such as sleeve lobectomy. Whether
pneumonectomy adversely affects long-term outcome after lung resection is
unknown. METHODS: We reviewed the cases of patients who underwent
lobectomy/bilobectomy or pneumonectomy because of non-small cell lung cancer
between January 1980 and June 1998. Survival curves were compared by the log-rank
test. Covariates were determined for operative mortality and survival using
logistic regression analysis and Cox proportional hazards estimation,
respectively. RESULTS: There were 259 men and 183 women who underwent
lobectomy/bilobectomy (340) or pneumonectomy (102). Operative mortality was 36
(8.1%) patients overall, 24 (7.0%) for lobectomy/bilobectomy and 12 (12%) for
pneumonectomy. Mean follow-up was 41 months (range 0-222 months). Median survival
was worse for pneumonectomy (stage II: 17.9 vs 36.3 months, log-rank P =. 05;
stage III: 11.7 vs 21.3 months, log-rank P =.07). However, important covariates
for survival were age, primary tumor status, regional nodal status, and forced
expiratory volume in 1 second. After adjusting for these covariates, survival did
not differ significantly between the types of operations (hazard ratio for
pneumonectomy 1.21; 95% CI 0.88-1.68). CONCLUSIONS: We did not detect a
significant long-term adverse influence of pneumonectomy on survival after
adjusting for other prognostic factors, but randomized clinical trials would be
needed to definitively address this issue.
PMID- 10694602
TI - Preemptive gastrointestinal tract management reduces aspiration and respiratory
failure after thoracic operations.
AB - OBJECTIVES: Respiratory failure is the major mode of death after general thoracic
operations. However, respiratory failure may develop from two very different
mechanisms: aspiration, often caused by ileus, and pneumonia, which often results
from poor pain control. Epidural catheters help control pain and prevent
pneumonia but contribute to ileus and may increase aspiration. We report a
decrease in the incidence of aspiration after changing postoperative care to
include gastrointestinal tract management. METHODS: All patients undergoing
elective thoracotomy by a single surgeon were evaluated for hospital mortality
and morbidity. For the first 21 months, patients did not receive an
intraoperative nasogastric tube and were prescribed an "advance as tolerated"
diet after the operation (n = 125). For the second period, nasogastric tubes were
placed intraoperatively and patients received nothing by mouth the day of
operation, clear liquids the first day, and a regular diet the second day (n =
153). Pneumonia was considered to have developed if infiltrates developed in a
single lobe or two adjoining lobes and culture of the sputa grew a dominant
organism. Patients were considered to have aspirated if diffuse infiltrates
developed or cultures grew multiple organisms. Significance of results was
determined by chi(2) testing. RESULTS: A total of 278 patients underwent elective
lung resection over a 3(1/2)-year period, 125 with ad libitum dietary management
and 153 with intensive management of the gastrointestinal tract. Six patients
(4.84%) aspirated before the institution of gastrointestinal tract management,
whereas none (0.0%) aspirated after the change. This difference was significant
(P =.01). Respiratory mortality was eliminated in the group with gastrointestinal
tract management (P =.04). CONCLUSIONS: Aspiration and its subsequent respiratory
failure and mortality can be decreased with preemptive gastrointestinal tract
management.
PMID- 10694603
TI - Chylothorax complicating esophagectomy for cancer: a plea for early thoracic duct
ligation.
AB - OBJECTIVE: Postoperative chylothorax remains an uncommon but potentially life
threatening complication of esophagectomy for cancer, and the ideal management is
still controversial. The aim of the study was to compare the outcomes of patients
treated nonoperatively with those of patients promptly undergoing reoperation.
METHODS: From 1980 to 1998, 1787 esophagectomies for esophageal or cardia cancer
were performed, and 19 (1.1%) patients had postoperative chylothorax. We analyzed
type of operation, surgical approach, delay of diagnosis of chylothorax, daily
chest tube output, type of management, major complications, death, hospital stay,
and final outcome. RESULTS: Of the 19 patients with chylothorax, 11 were
initially managed nonoperatively (group A): 4 (36%) patients had spontaneous
resolution of chylothorax, and the other 7 required reoperation for the
persistence of a high-volume output. There were three infectious complications
and one postoperative death in this group. No reliable predictive criteria of
successful versus unsuccessful nonoperative management could be found. The 8 most
recent patients underwent early reoperation (group B). All patients recovered,
and no major complications possibly related to chylothorax or hospital deaths
were observed. They were discharged after a median of 22 days (range, 12-85 days)
compared with a median of 36 days (range, 21-64 days) for patients of group A.
CONCLUSIONS: Early thoracic duct ligation is the treatment of choice for
chylothorax occurring after esophagectomy. Reoperation should be performed
immediately after the diagnosis is made to avoid the complications related to
nutritional and immunologic depletion caused by prolonged nonoperative treatment.
PMID- 10694604
TI - Secondary pulmonary hypertension does not adversely affect outcome after single
lung transplantation.
AB - OBJECTIVE: Primary and secondary pulmonary hypertension have been associated with
poor outcomes after single lung transplantation. Some groups advocate double lung
transplantation and the routine use of cardiopulmonary bypass during
transplantation in this population. However, the optimal procedure for these
patients remains controversial. The goal of our study was to determine the safety
of single lung transplantation without cardiopulmonary bypass in patients with
secondary pulmonary hypertension. METHODS: We retrospectively reviewed 76
consecutive patients with pulmonary parenchymal disease who underwent single lung
transplantation from 1992 to 1998. Recipients were stratified according to
preoperative mean pulmonary artery pressure. Secondary pulmonary hypertension was
defined as parenchymal lung disease with a preoperative mean pulmonary artery
pressure of 30 mm Hg or more. Patients with primary pulmonary hypertension or
Eisenmenger's syndrome were excluded from analysis. RESULTS: Eighteen of 76
patients had secondary pulmonary hypertension. No patient with secondary
pulmonary hypertension required cardiopulmonary bypass, whereas 1 patient without
pulmonary hypertension required bypass. After the operation, no significant
differences were seen in lung injury as measured by chest radiograph score and
PaO(2)/FIO(2) ratio, the requirement for inhaled nitric oxide, the length of
mechanical ventilation, the intensive care unit or hospital length of stay, and
30-day survival. There were no differences in the forced expiratory volume in 1
second or 6-minute walk at 1 year, or the incidence of rejection, infection, or
bronchiolitis obliterans syndrome greater than grade 2. Survival at 1, 2, and 4
years after transplantation was 86%, 79%, and 65%, respectively, in the low
pulmonary artery pressure group and 81%, 81%, and 61%, respectively, in the group
with secondary pulmonary hypertension (P >.2). CONCLUSION: We found that patients
with pulmonary parenchymal disease and concomitant secondary pulmonary
hypertension had successful outcomes as measured by early and late allograft
function and appear to have acceptable long-term survival after single lung
transplantation. Our results do not support the routine use of cardiopulmonary
bypass or double lung transplantation for patients with this disorder.
PMID- 10694605
TI - Heart-lung versus double-lung transplantation for suppurative lung disease.
AB - OBJECTIVE: The purpose of this study was to compare outcomes after heart-lung or
double-lung transplantation in patients undergoing transplantation because of end
stage suppurative lung disease. METHODS: We reviewed our experience in patients
with cystic fibrosis or bronchiectasis who had heart-lung or double-lung
transplantation between January 1988 and September 1997. Twenty-three patients
(14 male, 21 cystic fibrosis) had heart-lung transplantation and 24 patients (8
male, 19 cystic fibrosis) had double-lung transplantation. There were no
statistically significant differences between the groups in age, weight,
preoperative creatinine level, cytomegalovirus status, maintenance
immunosuppression, or donor demographics. Patients received induction therapy
with monoclonal (OKT3) or polyclonal (rabbit anti-thymocyte globulin) antibody.
RESULTS: Sixteen of 24 patients had double-lung transplantation after 1994
whereas 13 of 22 patients had heart-lung transplantation before 1991, allowing
longer follow-up for the heart-lung group. Mean waiting times for transplantation
were 270 +/- 245 days (heart-lung) and 361 +/- 229 days (double-lung; P =.20).
The 1-, 3-, and 5-year actuarial survival figures were respectively 86%, 82%, and
65% (heart-lung) and 96%, 75%, and unavailable (double-lung; P = no significant
difference). The 1-, 3-, and 5-year rates of freedom from obliterative
bronchiolitis were respectively 77%, 61%, and 45% (heart-lung) and 86%, 78%, and
unavailable (double-lung; P = no significant difference). Linearized overall
infection rates (events/100 patient-days) were 2.05 +/- 0.33 (heart-lung) and
2.34 +/- 0.34 (double-lung; P = NS) at 3 months. Thirty-day survival was 100%
(heart-lung) and 96% (double-lung). There were 7 late deaths among heart-lung
recipients (3 obliterative bronchiolitis, 2 infection, 0 graft coronary artery
disease, 2 other) whereas 2 late deaths related to obliterative bronchiolitis
occurred in double-lung recipients. Graft coronary artery disease (all stenoses <
50%) affected 15% of heart-lung survivors, whereas 3 double-lung recipients
(12.5%) required either bronchial dilatation or stenting. CONCLUSION: Heart-lung
and double-lung transplantation provide similar palliation for patients with end
stage suppurative lung disease. Therefore double-lung transplantation should be
the preferred operation for most patients with end-stage suppurative lung
disease.
PMID- 10694606
TI - Evidence against a pivotal role of preformed antibodies in delayed rejection of a
guinea pig-to-rat heart xenograft.
AB - INTRODUCTION: Whereas the involvement of elicited xenoantibodies in delayed
xenograft rejection is currently being substantiated, this study focuses on the
role of the preformed fraction of xenoantibodies. METHODS: To check the influence
of the latter, we combined pretransplant complement inactivation (cobra venom
factor) and antibody reduction (plasmapheresis) in a guinea pig-to-rat heart
transplant model. RESULTS: Antibody reduction on plasmapheresis before
xenografting did not prolong delayed xenorejection in decomplemented rats,
although the immunohistologic pattern lacked the immunoglobulin deposits along
endothelial walls found in xenografts of merely decomplemented recipients.
Astonishingly, plasmapheresis, if carried out 2 days before transplantation,
almost tripled xenograft survival, although preformed antibody levels were
completely restored and even rebounding at the time of grafting. The pattern and
number of infiltrating cells did not differ in dependence of the timing of
plasmapheresis nor did the proliferative response of lymphocytes in the mixed
lymphocyte reaction differ. However, plasmapheresis led to a retarded decrease of
the mononuclear cell tumor necrosis factor alpha secretory potential, which
correlated well with a diminished immunohistologic staining of tumor necrosis
factor alpha secreted by graft-infiltrating mononuclear cells. CONCLUSION: These
findings argue against a pivotal role of preformed xenoantibodies in the
pathomechanistic process of delayed xenograft rejection and challenge the
therapeutic strategy to reduce preformed xenoantibody levels before
xenotransplantation in complement-inactivated recipients.
PMID- 10694607
TI - Raffinose improves the function of rat pulmonary grafts stored for twenty-four
hours in low-potassium dextran solution.
AB - OBJECTIVES: The perfect strategy for pulmonary graft preservation remains
elusive. Experimental work supports the use of perfusates, such as Euro-Collins,
University of Wisconsin, and low-potassium dextran solutions. We use low
potassium dextran solution in our clinical program, but we aim for continued
improvement. The trisaccharide raffinose has been shown to be responsible for the
efficacy of University of Wisconsin perfusate in lung preservation. Raffinose is
superior to a variety of other saccharides for this purpose. We tested the
hypothesis that the addition of raffinose to low-potassium dextran solution might
further improve graft function. METHODS: In a randomized blinded study with a rat
left lung transplant model, donor lungs were flushed with either standard low
potassium dextran solution or low-potassium dextran solution modified by the
addition of 30 mmol/L raffinose (n = 5 for each group). Alprostadil
(prostaglandin E(1), 500 microg/L) was added to the perfusates in accordance with
our clinical practice. Grafts were stored inflated at 4 degrees C for 24 hours.
After transplantation, recipients were ventilated with a fraction of inspired
oxygen of 1 and a positive end-expiratory pressure of 2 cm H(2)O. Graft function
was evaluated by measuring oxygenation at 2 hours after graft reperfusion, peak
airway pressure throughout the reperfusion period, and the wet/dry lung weight
ratio. RESULTS: The group receiving low-potassium dextran solution with raffinose
demonstrated significantly higher oxygenation (oxygen tension, 370 +/- 45 mm Hg
vs 150 +/- 64 mm Hg; P =.0025), lower peak airway pressures at 2 hours after lung
reperfusion (11 +/- 2.7 mm Hg vs 16 +/- 2.4 mm Hg; P <.001), and a lower wet/dry
weight ratio (4.7 +/- 1.26 vs 11 +/- 5. 0; P =.017). CONCLUSION: Modification of
low-potassium dextran solution with the trisaccharide raffinose resulted in a
significant improvement in graft function in this model and merits further
evaluation with respect to the mechanisms involved.
PMID- 10694608
TI - Highly efficient ex vivo gene transfer to the transplanted heart by means of
hypothermic perfusion with a low dose of adenoviral vector.
AB - BACKGROUND: Hypothermic conditions required for donor heart preservation may
reduce gene-transfer efficiency. Experiments were designed to determine whether a
perfusion technique could improve the efficiency of gene transfer to donor
hearts. METHODS: An adenoviral vector encoding beta-galactosidase (3.5 x 10(8)
plaque-forming units) was infused into explanted rat hearts under 4 conditions
(each n = 6): (1) the virus was diluted in 350 microL of University of Wisconsin
solution and infused as a high-pressure bolus into the coronary arteries of donor
hearts through the aortic root; (2) the virus was diluted in 5 mL of University
of Wisconsin solution and circulated by means of a peristaltic pump (flow, 0.75
mL/min) through the vasculature of the donor heart for 30 minutes; (3) 5 mL of
viral solution was circulated as for group 2 for 15 minutes; and (4) 5 mL of
viral solution was circulated for 5 minutes at a flow rate of 2.4 mL/min.
Transduced hearts were transplanted into the abdomen of syngeneic rats, and
transgene expression was assessed by means of immunoassay 4 days later. RESULTS:
The median beta-galactosidase content was (1) 45.0 ng/mg protein (25th-75th
percentile, 33-73 ng/mg), (2) 640 ng/mg protein (25th-75th percentile, 614-878
ng/mg), (3) 493.8 ng/mg protein (25th-75th percentile, 456-527 ng/mg), and (4)
503.3 ng/mg protein (25th-75th percentile, 475-562 ng/mg; P <.01 for group 2 vs
group 1, and P <.05 for groups 3 and 4 vs group 1). Transgene expression was
predominantly in myocytes and favored the subepicardial region of the right
ventricle. CONCLUSION: Hypothermic perfusion of the donor heart with an
adenoviral vector resulted in efficient transgene expression compared with that
induced by a single bolus injection.
PMID- 10694610
TI - Commentary
PMID- 10694609
TI - Pulmonary function after modified venovenous ultrafiltration in infants: a
prospective, randomized trial.
AB - OBJECTIVE: We sought to examine the effects of modified venovenous
ultrafiltration after cardiopulmonary bypass on pulmonary compliance in infants.
METHODS: We prospectively enrolled 38 infants undergoing their first operation
for congenital heart disease. Infants were randomized to receive 20 minutes of
modified ultrafiltration after bypass or control. Static and dynamic compliance
was measured after induction of anesthesia, before and immediately after
filtration in the operating theater, 1 hour after return to the pediatric
intensive care unit, and 24 hours after the operation. Length of time on the
ventilator, inotropic requirements, and length of stay in the intensive care unit
were recorded. RESULTS: Modified ultrafiltration produced a significant immediate
improvement in dynamic (pre-ultrafiltration 2.5 +/- 1.9 mL/cm H(2)O to post
ultrafiltration 2.9 +/- 2.7 mL/cm H(2)O, P =.03) and static (pre-ultrafiltration
2.1 +/- 0.9 mL/cm H(2)O to post-ultrafiltration 2.9 +/- 2.1 mL/cm H(2)O, P =.04)
compliance. However, there was no significant difference in the change in dynamic
(P =.3) or static (P =.7) compliance in the ultrafiltration and control groups
when compared before the operation, after the operation, and at 24 hours. There
was no significant difference in the time to extubation between patients and
control subjects (140 +/- 91 hours vs 90 +/- 58 hours) or the length of intensive
care unit stay (10.0 +/- 9.1 days vs 7.4 +/- 5.7 days). CONCLUSIONS: Modified
ultrafiltration produces an improvement in pulmonary compliance after bypass in
infants. However, these improvements are not sustained past the immediate post
ultrafiltration period and do not lead to a decreased length of intubation or
intensive care unit stay.
PMID- 10694611
TI - Repair of the truncal valve and associated interrupted arch in neonates with
truncus arteriosus.
AB - OBJECTIVE: Truncal valve regurgitation and interrupted aortic arch have
frequently been identified as risk factors in the repair of truncus arteriosus.
We wished to examine these factors in the current era including the impact of
truncal valve repair. METHODS: Between January 1992 and August 1998, 50 patients
underwent surgical repair of truncus arteriosus. Their ages ranged from 2 days to
6 months (median, 2 weeks). Nine patients had associated interrupted aortic arch.
Of the 14 patients (28%) in whom truncal valve regurgitation was diagnosed
preoperatively, 5 had mild regurgitation, 5 had moderate regurgitation, and 4 had
severe regurgitation. Five underwent truncal valve repair and 1 underwent
homograft replacement of the truncal valve with coronary reimplantation. RESULTS:
The actuarial survival was 96% at 30 days, 1 year, and 3 years. There were no
deaths in patients with associated interrupted aortic arch. The 2 deaths in the
series occurred in patients with truncal valve regurgitation, neither of whom
underwent repair. Postoperative transthoracic echocardiography in patients who
underwent valve repair showed minimal residual valvular regurgitation. None of
the patients has required reoperation because of truncal valve problems or aortic
arch stenosis at a median follow-up of 23 months (range, 1-60 months). Conduit
replacement has been done in 17 patients (34%) after a mean duration of 2 years.
The freedom from reoperation for those who had an aortic homograft was 4 years
and for those who had a pulmonary homograft was 3 years. CONCLUSION: Despite the
magnitude of the operation, excellent results can be achieved in complex forms of
truncus arteriosus. In the current era interrupted aortic arch is no longer a
risk factor for repair of truncus. Aggressive application of truncal
valvuloplasty methods should neutralize the traditional risk factor of truncal
valve regurgitation.
PMID- 10694612
TI - Does the degree of cyanosis affect myocardial adenosine triphosphate levels and
function in children undergoing surgical procedures for congenital heart disease?
AB - OBJECTIVE: The outcome of children with cyanosis after cardiac surgical
procedures is inferior to that of children who are acyanotic. Animal studies
indicated detrimental effects of chronic hypoxia on myocardial metabolism and
function. We studied whether the presence or the degree of cyanosis adversely
affected myocardial adenosine triphosphate, ventricular function, and clinical
outcome in children. METHODS: Forty-eight children who underwent repair of
tetralogy of Fallot were divided according to their preoperative saturation:
group I, 90% to 100% (n = 14 patients); group II, 80% to 89% (n = 16 patients);
and group III, 65% to 79% (n = 18 patients). Adenosine triphosphate was measured
from right ventricular biopsy specimens taken before ischemia, at 15 minutes of
ischemia, at end-ischemia, and at 15 minutes of reperfusion. Ejection fraction
was measured by echocardiography. RESULTS: Even before surgical ischemia,
compared with groups I and II, group III had lower preoperative ejection fraction
(59% +/- 2.9% vs 67% +/- 1.7% and 68% +/- 1.0%; P <.01) and lower preischemic
adenosine triphosphate levels (15.1 +/- 2.1 vs 19.1 +/- 1.9 and 21.4 +/- 1.5
micromol/g dry weight; P <.01). After 15 minutes of ischemia, group III had lower
adenosine triphosphate levels (11.2 +/- 1.8 vs 14.77 +/- 2.3 and 17. 6 +/- 3.1
micromol/g dry weight; P <.01). With reperfusion, both cyanotic groups lost
further adenosine triphosphate compared with partial recovery in the acyanotic
group (-22% +/- 3.8%, -20% +/- 3. 1% vs +18% +/- 1.8%; P <.01). Children in group
III had a more complicated postoperative course as evidenced by longer
ventilatory support (85 +/- 25 hours vs 31 +/- 15 and 40 +/- 21 hours; P =.07),
inotropic support (86 +/- 23 hours vs 38 +/- 12 and 36 +/- 4 hours; P <.01), and
intensive care unit stay (160 +/- 35 hours vs 60 +/- 10 and 82 +/- 18 hours; P
=.02). CONCLUSIONS: The degree of cyanosis adversely affects myocardial adenosine
triphosphate, function, and clinical outcome of children who undergo cardiac
operation. Children with cyanosis should be identified as a higher risk group
that could be targeted for supportive interventions.
PMID- 10694613
TI - Oxygen consumption after cardiopulmonary bypass surgery in children: determinants
and implications.
AB - OBJECTIVE: We sought to assess oxygen consumption and its determinants in
children shortly after undergoing cardiopulmonary bypass operations. METHODS:
Twenty children, aged 2 months to 15 years (median, 3.75 years), undergoing
hypothermic cardiopulmonary bypass operations were studied during the first 4
hours after arrival in the intensive care unit. Central and peripheral
temperatures were monitored. Oxygen consumption was continuously measured by
using respiratory mass spectrometry. Oxygen delivery was calculated from oxygen
consumption and arterial and mixed venous oxygen contents, which were sampled
every 30 minutes. Oxygen extraction was derived by the ratio of oxygen
consumption and oxygen delivery. Arterial blood lactate levels were measured
every 30 minutes. RESULTS: There was a correlation between oxygen consumption and
age in patients older than 3 months (r = -0.76). Mean oxygen consumption
increased by 14.7% during the study. The increase in oxygen consumption was
correlated with the increase in central temperature (r = 0.73). Nine patients had
an arterial lactate level above 2 mmol/L on arrival. There were no significant
differences in oxygen consumption, oxygen delivery, and oxygen extraction between
the group with lactate levels between 2 and 3 mmol/L and the groups with normal
lactate levels both on arrival and at 2 hours. One patient with a peak lactate
level of 6.8 mmol/L had initially low oxygen delivery (241.3 mL. min(-1). m(-2)).
CONCLUSIONS: During the early hours after a pediatric cardiac operation, the
increase in oxygen consumption is mainly attributed to the increase in central
temperature. Oxygen consumption is negatively related to age. Mild lactatemia is
common and does not appear to reflect oxygen delivery or oxygen consumption or a
more complicated recovery.
PMID- 10694614
TI - Vascular endothelial growth factor and basic fibroblast growth factor in children
with cyanotic congenital heart disease.
AB - OBJECTIVE: Vascular endothelial growth factor and basic fibroblast growth factor
are potent stimulators of angiogenesis. Children with cyanotic congenital heart
disease often experience the development of widespread formation of collateral
blood vessels, which may represent a form of abnormal angiogenesis. We undertook
the present study to determine whether children with cyanotic congenital heart
disease have elevated serum levels of vascular endothelial growth factor and
basic fibroblast growth factor. METHODS: Serum was obtained from 22 children with
cyanotic congenital heart disease and 19 children with acyanotic heart disease
during cardiac catheterization. Samples were taken from the superior vena cava,
inferior vena cava, and a systemic artery. Vascular endothelial growth factor and
basic fibroblast growth factor levels were measured in the serum from each of
these sites by enzyme-linked immunosorbent assay. RESULTS: Vascular endothelial
growth factor was significantly elevated in the superior vena cava (P =.04) and
systemic artery (P =.02) but not in the inferior vena cava (P =.2) of children
with cyanotic congenital heart disease compared to children with acyanotic heart
disease. The mean vascular endothelial growth factor level, determined by
averaging the means of all 3 sites, was also significantly elevated (P =.03).
Basic fibroblast growth factor was only significantly elevated in the systemic
artery (P =.02). CONCLUSION: Children with cyanotic congenital heart disease have
elevated systemic levels of vascular endothelial growth factor. These findings
suggest that the widespread formation of collateral vessels in these children may
be mediated by vascular endothelial growth factor.
PMID- 10694615
TI - Transmyocardial laser revascularization combined with coronary artery bypass
grafting: a multicenter, blinded, prospective, randomized, controlled trial.
AB - OBJECTIVE: We sought to assess the safety and efficacy of transmyocardial
revascularization combined with coronary artery bypass grafting in patients not
amenable to complete revascularization by coronary bypass alone. METHODS: A total
of 263 patients whose standard of care was coronary artery bypass grafting and
who had one or more ischemic areas not amenable to bypass grafting were
prospectively randomized to receive coronary bypass of suitable vessels plus
transmyocardial revascularization to areas not graftable (n = 132) or coronary
bypass alone with nongraftable areas left unrevascularized (n = 131). Group
preoperative demographics and operative characteristics were similar. RESULTS:
The operative mortality rate after coronary bypass/transmyocardial
revascularization was 1.5% (2/132) versus 7.6% (10/131) after coronary bypass
alone (P =.02). Patients undergoing both coronary bypass and transmyocardial
revascularization required less postoperative inotropic support (30% vs 55%, P
=.0001) and had a trend toward fewer insertions of intra-aortic balloon pumps (4%
vs 8%, P =.13) than did patients having coronary bypass alone. Multivariable
predictors of operative mortality were coronary artery bypass alone (odds ratio,
5.3; 95% confidence interval, 1.1-25.7; P =.04) and increased age (odds ratio,
1.1; 95% confidence interval, 1. 0-1.2; P =.03). One-year Kaplan-Meier survival
(95% vs 89%, P =.05) and freedom from major adverse cardiac events defined as
death or myocardial infarction (92% vs 86%, P =.09) favored the combination of
coronary bypass and transmyocardial revascularization. Baseline to 12-month
improvement in angina and exercise treadmill scores was similar between groups.
CONCLUSIONS: In a prospective, randomized, multicenter trial, transmyocardial
revascularization combined with coronary artery bypass grafting in patients not
amenable to complete revascularization by coronary bypass alone was safe;
however, angina relief and exercise treadmill improvement were indistinguishable
between groups at 12 months of follow-up. Operative and 1-year survival benefits
observed after adjunctive transmyocardial revascularization require confirmation
by a larger validation study, which is ongoing.
PMID- 10694616
TI - Results of revascularization in patients with severe left ventricular
dysfunction.
AB - OBJECTIVE: In patients with coronary disease and poor left ventricular function,
bypass grafting remains a surgical challenge. This study evaluates experience in
125 consecutive patients with ejection fraction less than 20% (study group).
METHODS: Preoperative viability studies were not used for patient selection.
Clinical data were prospectively collected. The average age of the study subjects
was 59 +/- 9 years, and 112 (90%) were male. Most patients (108 [86%]) were in
symptom class III or IV. Main indications for surgery included angina in 62
(50%), heart failure and angina in 36 (29%), heart failure in 9 (7%), ventricular
arrhythmia in 2 (2%), and critical anatomy in 16 (13%). Significant mitral
regurgitation was present in 48 (38%), and distal vessels were poorly visualized
in 67 (54%). At surgery, temperature mapping guided an integrated approach to
cold cardioplegia. Results in this group were compared with those obtained in
case-matched control subjects receiving cardioplegia without temperature mapping
(matched for age, sex, functional class, and urgency of operation). RESULTS:
Hospital morbidity (intra-aortic balloon pump support) and mortality rates were
significantly lower in the study group versus those of control subjects (15% vs
30%, P =. 004; and 4% vs 11%, P =.03, respectively). In study patients the 5-year
actuarial survival was 72%. Among survivors, both anginal class and heart failure
class improved significantly. By means of multivariate analysis, survival was
adversely affected by older age, class IV symptoms, and poorly visualized distal
vessels. CONCLUSIONS: These results support the use of coronary artery bypass
grafting in patients with severe left ventricular dysfunction without case
selection on the basis of viability studies or visibility of distal vessels. Low
hospital morbidity and mortality rates have been achieved when temperature
mapping guides cardioplegia. Symptoms are improved in most patients, and long
term survival is encouraging.
PMID- 10694617
TI - Extended total arch replacement for acute type a aortic dissection: experience
with seventy patients.
AB - OBJECTIVE: We sought to report the clinical experience with extended total arch
replacement for acute type A aortic dissection and to determine the factors that
influence early mortality, late survival, and late reoperation. METHODS: Between
December 1988 and August 1998, 70 patients underwent emergency graft replacement
of both the ascending aorta and the total aortic arch for acute type A aortic
dissection. All operations were performed with hypothermic extracorporeal
circulation, selective cerebral perfusion for cerebral protection during aortic
arch repair, and open distal anastomosis. Concomitant procedures included aortic
valve resuspension in 18 patients, composite graft replacement in 10 patients,
and coronary artery bypass grafting in 5 patients. RESULTS: The early mortality
rate was 16% (11 of 70 patients). Multivariable analysis showed that renal
mesenteric ischemia and coronary artery bypass grafting were independent
determinants for early death. Survival rates at 3 and 5 years postoperatively,
including the early deaths, were 75% +/- 5% and 73% +/- 6%, respectively.
Multivariable analysis showed that renal-mesenteric ischemia and en bloc repair
were independent determinants for late death. Freedom from reoperation was 91% +/
4% and 77% +/- 8% at 3 and 5 years, respectively. Multivariable analysis showed
that anastomotic leakage was the only significant determinant for late
reoperation. CONCLUSIONS: Extended total arch replacement for acute type A aortic
dissection could be justified in properly selected patients.
PMID- 10694619
TI - Topical use of tranexamic acid in coronary artery bypass operations: a double
blind, prospective, randomized, placebo-controlled study.
AB - OBJECTIVES: We sought to investigate the effect of topical application of
tranexamic acid into the pericardial cavity in reducing postoperative blood loss
in coronary artery surgery. METHODS: A prospective, randomized, double-blind
investigation with parallel groups was performed. Forty consecutive patients
undergoing primary coronary surgery were randomly assigned to group 1 (tranexamic
acid group) or group 2 (placebo group). Tranexamic acid (1 g in 100 mL of saline
solution) or placebo was poured into the pericardial cavity and over the
mediastinal tissues before sternal closure. The drainage of mediastinal blood was
measured hourly. RESULTS: Chest tube drainage in the first 24 hours was 485 +/-
166 mL in the tranexamic acid group and 641 +/- 184 mL in the placebo group (P
=.01). Total postoperative blood loss was 573 +/- 164 mL and 739 +/- 228 mL,
respectively (P =.01). The use of banked donor blood products was not
significantly different between the two groups. Tranexamic acid could not be
detected in any of the blood samples blindly collected from 24 patients to verify
whether any systemic absorption of the drug occurred. There were no deaths in
either group. None of the patients required reoperation for bleeding.
CONCLUSIONS: Topical application of tranexamic acid into the pericardial cavity
after cardiopulmonary bypass in patients undergoing primary coronary bypass
operations significantly reduces postoperative bleeding. Further studies must be
carried out to clarify whether a more pronounced effect on both bleeding and
blood products requirement might be seen in procedures with a higher risk of
bleeding.
PMID- 10694618
TI - Sodium nitroprusside in patients with compromised left ventricular function
undergoing coronary bypass: reduction of cardiac proinflammatory substances.
AB - OBJECTIVE: The aim of the present study was to investigate whether the nitric
oxide donor sodium nitroprusside can reduce the cardiac inflammatory response
during coronary artery bypass grafting in patients with severely compromised left
ventricular function. METHODS: Patients (n = 30) were assigned to receive placebo
or sodium nitroprusside (0.5 microg. kg(-1). min(-1)) for the first 60 minutes of
reperfusion. Interleukin 6, interleukin 8, and tumor necrosis factor alpha
levels; platelet adhesion molecule CD41 and CD62 levels; and CD11b on leukocytes
were determined in the radial artery and coronary sinus before cardiopulmonary
bypass and during reperfusion (1, 5, 10, 35, and 75 minutes). RESULTS: At 1
minute of reperfusion, coronary venous levels of CD41-positive polymorphonuclear
leukocytes were 8% lower than arterial levels in the placebo group and 18% higher
in the sodium nitroprusside group (P =.021). At 5 minutes of reperfusion, the
respective levels were 29% and 1% for interleukin 6 (P =.015), -5% and 20% for
CD41-positive monocytes (P =.032), and -2% and 16% for CD11b-positive monocytes
(P =.038). At 10 minutes of reperfusion, these levels were -14% and 21% for CD41
positive monocytes (P =.006). At 35 minutes of reperfusion, these levels were
13% and 7% for CD41-positive monocytes (P =.017), -41% and 23% for CD11b-positive
monocytes (P =.001), and 7% and 25% for CD62-positive platelets (P =. 041). At 75
minutes of reperfusion, the levels were 15% and -7% for tumor necrosis factor
alpha (P =.025) and -10% and 10% for CD62-positive platelets (P =.041).
CONCLUSIONS: Transcardiac production of proinflammatory cytokines is reduced in
patients undergoing coronary artery bypass grafting treated with the nitric oxide
donor sodium nitroprusside. At the same time, less activated leukocytes and
platelets are retained in the coronary circulation.
PMID- 10694620
TI - Novacor left ventricular assist system versus Heartmate vented electric left
ventricular assist system as a long-term mechanical circulatory support device in
bridging patients: a prospective study.
AB - OBJECTIVE: Long-term mechanical circulatory support as a bridge-to
transplantation procedure and bridge to recovery is of increasing importance. The
implantable left ventricular assist devices, Novacor N100 left ventricular assist
system (Baxter Healthcare Corporation, Berkeley, Calif) and TCI HeartMate vented
electric left ventricular assist system (Thermo Cardiosystems Inc, Woburn, Mass),
have proved to be efficient devices in bridge-to-transplantation settings and for
prolonged support. The two systems were compared with regard to reliability and
morbidity. METHODS: Between October 1996 and March 1998, a prospective, single
center study was done that included 40 patients, 20 of whom were treated with the
Novacor system and 20 of whom were treated with the HeartMate device. The
diseases were mainly dilated cardiomyopathy (13/9) and ischemic cardiomyopathy
(6/10). There were no statistically significant differences between the two
groups regarding age, sex, preoperative clinical blood chemistry values,
hemodynamic data, or risk factors. RESULTS: There were no statistically
significant differences between the two groups with regard to postoperative
hemodynamics, organ recovery, out-of-hospital support, and survival to heart
transplantation. Mean duration of support was 235.3 +/- 210 days for the Novacor
group and 174.6 +/- 175 days for the HeartMate group and mean out-of-hospital
support was 241 +/- 179 days and 166 +/- 152 days for the two groups,
respectively. Neurologic complications occurred significantly more often among
the Novacor group, whereas the HeartMate group had a higher prevalence of
infections and technical problems, which was statistically significant. Survival
to transplantation was 65% for the Novacor group and 60% for the HeartMate group.
CONCLUSIONS: Most patients had organ recovery with left ventricular assist system
support, and a considerable number of patients in both groups underwent
transplantation. However, both devices need revision to address the current
problems, that is, thromboembolism for the Novacor device and infection and
reliability for the HeartMate device.
PMID- 10694621
TI - Hypothermic retrograde venous perfusion with adenosine cools the spinal cord and
reduces the risk of paraplegia after thoracic aortic clamping.
AB - OBJECTIVE: We evaluated the utility of retrograde venous perfusion to cool the
spinal cord and protect neurologic function during aortic clamping. We
hypothesized that hypothermic adenosine would preserve the spinal cord during
ischemia. METHODS: Six swine (group I) underwent thoracic aortic occlusion for 30
minutes at normothermia. Group II animals underwent spinal cooling by retrograde
perfusion of the paravertebral veins with hypothermic (4 degrees C) saline
solution during aortic occlusion. The spinal cords of group III animals were
cooled with a hypothermic adenosine solution in a similar fashion. Intrathecal
temperature was monitored and somatosensory evoked potentials assessed the
functional status of spinal pathways. RESULTS: Spinal cooling without systemic
hypothermia significantly improved neurologic Tarlov scores in group III (4.8 +/-
0.2) and group II (3.8 +/- 0.4) when compared with group I scores (1.3 +/- 0.6)
(P <.001). Furthermore, 5 of the 6 animals in group III displayed completely
normal neurologic function, whereas only one animal in group II and no animals in
group I did (P =.005). Somatosensory evoked potentials were lost 10.6 +/- 1.4
minutes after ischemia in group I. In contrast, spinal cooling caused rapid
cessation of neural transmission with loss of somatosensory evoked potentials at
6.9 +/- 1.2 minutes in group II and 7.0 +/- 0.8 minutes in group III (P =.06).
Somatosensory evoked potential amplitudes returned to 85% of baseline in group
III and 90% of baseline in group II compared with only 10% of baseline in group I
(P =.01). CONCLUSIONS: We conclude that retrograde cooling of the spinal cord is
possible and protects against ischemic injury and that adenosine enhances this
effect. The efficacy of this method may be at least partly attributed to a more
rapid reduction in metabolic and electrical activity of the spinal cord during
ischemia.
PMID- 10694622
TI - Single-center experience with the thoratec ventricular assist device.
AB - OBJECTIVE: The Thoratec ventricular assist device (Thoratec Laboratories,
Pleasanton, Calif) is widely accepted for univentricular and biventricular
support in patients with various indications. The aim of this study is to
describe our experience with implantation of the Thoratec ventricular assist
device in more than 100 patients. METHODS: From March 1992 to June 1998, 114
patients (98 men and 16 women; mean age, 47.9 years) received the Thoratec
ventricular assist device for a mean duration of 44.9 days. The patients were
divided into 3 groups. Group 1 included 84 patients in whom the system was
applied as a bridge-to-transplant procedure. Group 2 included 17 patients with
postcardiotomy cardiogenic shock, and group 3 included 13 patients with
cardiogenic shock of other causes. RESULTS: Sixty-eight percent of patients in
group 1 survived to transplantation with a posttransplant survival of 88%. The
only independent risk factor affecting survival was age more than 60 years.
Survivals in groups 2 and 3 were 47% and 31%, respectively. Main complications in
all groups were bleeding, multiple organ failure, liver failure, sepsis, and
neurologic disorders. CONCLUSIONS: The Thoratec ventricular assist device has
proved to be a reliable device for bridge to transplantation and postcardiotomy
support. Further studies are required on patient selection and on patient and
device management to reduce the incidence of complications in these patient
populations.
PMID- 10694623
TI - Mechanisms of myocardial protection by adenosine-supplemented cardioplegic
solution: myofilament and metabolic responses.
AB - OBJECTIVE: Adenosine supplementation of cardioplegic solutions in cardiac
operations improves postarrest myocardial recovery after cardioplegic arrest and
reperfusion; however, the mechanism of the action of adenosine remains unknown.
We tested the hypotheses that adenosine-supplemented cardioplegic solution
improves myofibrillar protein cooperative interaction and increases myocardial
anaerobic glycolysis. METHODS: The hearts of male Sprague-Dawley rats were
randomized to undergo 120 minutes of cardioplegic arrest with 1 of 3 cardioplegic
solutions: (1) St Thomas' Hospital No. 2 cardioplegic solution (St Thomas group),
(2) St Thomas' Hospital No. 2 cardioplegic solution plus adenosine (100
micromol/L) (adenosine group), and (3) St Thomas' Hospital No. 2 cardioplegic
solution plus adenosine (100 micromol/L) plus the nonspecific adenosine receptor
antagonist 8-p -sulfophenyltheophylline (50 micromol/L) (sulfophenyltheophylline
group). A fourth group of hearts underwent no cardioplegic arrest. RESULTS:
Systolic and diastolic functional recovery was improved in the adenosine group
compared with that in the other two groups, independent of coronary flow.
Adenosine supplementation of cardioplegic solution prevented the decrease in
myofibrillar protein cooperative interaction seen after cardioplegic arrest and
reperfusion (St Thomas and sulfophenyltheophylline groups). Adenosine
supplemented cardioplegic solution also caused significantly increased anaerobic
glycolysis during cardioplegic arrest. These responses were blocked in the
sulfophenyltheophylline group. CONCLUSIONS: The changes in myocardial glycolytic
activity and myofilament cooperativity coincided with functional recovery in the
three cardioplegia groups and may represent mechanisms underlying protection with
adenosine-supplemented cardioplegic solution.
PMID- 10694624
TI - Intermediate lukewarm (20 degrees c) antegrade intermittent blood cardioplegia
compared with cold and warm blood cardioplegia.
AB - BACKGROUND: In the field of intermittent antegrade blood cardioplegia, 3 levels
of temperature are commonly used: (1) cold (8 degrees C); (2) tepid (29 degrees
C); and (3) warm (37 degrees C). Given the 21 degrees C spread and the metabolic
changes that can occur between cold (8 degrees C) and tepid (29 degrees C)
cardioplegia, we thought it worthwhile to test a temperature halfway between the
cold and tepid levels. The aim of this study was to test the quality of
myocardial protection provided by intermediate lukewarm (20 degrees C)
cardioplegia by comparing it with cold and warm cardioplegia. Protection was
assessed by measuring cardiac troponin I release. METHODS: One hundred thirty
five patients undergoing coronary artery bypass grafting were enrolled in a
prospective randomized trial comparing cold (8 degrees C), intermediate lukewarm
(20 degrees C), and warm (37 degrees C) antegrade intermittent blood
cardioplegia. Cardiac troponin I concentrations were measured in serial venous
blood samples. RESULTS: The total amount of cardiac troponin I released was
significantly higher in the cold group (4.7 +/- 2.3 microg) than in the
intermediate lukewarm (3.4 +/- 2.0 microg) or the warm (3.1 +/- 2.7 microg)
groups. The cardiac troponin I concentration was significantly higher at hour 6
in the intermediate lukewarm group (1. 23 +/- 0.55 microg/L) than in the warm
group (0.89 +/- 0.50 microg/L). CONCLUSIONS: Intermittent antegrade intermediate
lukewarm blood cardioplegia is appropriate and clinically safe. Cardiac troponin
I release suggests that intermediate lukewarm cardioplegia is better than cold
cardioplegia but less effective than warm cardioplegia in low-risk patients. We
therefore recommend the use of warm cardioplegia in low-risk patients.
PMID- 10694625
TI - Brain function monitoring during bidirectional Glenn procedures.
PMID- 10694626
TI - Endovascular stent-graft repair with a flexible stent-graft and a simple
applicator prepared from a syringe.
PMID- 10694627
TI - Lymphangioleiomyomatosis: the surgeon's role in diagnosis.
PMID- 10694628
TI - Clinical-pathologic conference in thoracic surgery: Masaoka stage 2-a thymoma.
PMID- 10694629
TI - Venovenous modified ultrafiltration after cardiopulmonary bypass in children: A
prospective randomized study
PMID- 10694630
TI - Alternate explanation of the additive protective effects of regional infusion of
hypothermic saline and adenosine solutions.
PMID- 10694631
TI - Should methylene blue be the drug of choice to treat vasoplegias caused by
cardiopulmonary bypass and anaphylactic shock?
PMID- 10694632
TI - Should methylene blue be the drug of choice to treat vasoplegias caused by
cardiopulmonary bypass and anaphylactic shock?
PMID- 10694633
TI - Combined mitral valve repair and the cox maze procedure for mitral valve prolapse
and regurgitation and associated atrial fibrillation.
PMID- 10694634
TI - Should the bidirectional glenn procedure be better performed through the support
of cardiopulmonary bypass?
PMID- 10694635
TI - Should the bidirectional glenn procedure be better performed through the support
of cardiopulmonary bypass?
PMID- 10694636
TI - Preimplantation retrograde pneumoplegia in clinical lung transplantation.
PMID- 10694637
TI - Preimplantation retrograde pneumoplegia in clinical lung transplantation
PMID- 10694638
TI - Retirement of journal editor
PMID- 10694639
TI - Children will benefit as pediatric groups merge: a surgical oncologist's
perspective.
PMID- 10694640
TI - Do the newer imaging modalities affect management of solid tumors?
PMID- 10694641
TI - Prognostic significance of mucinous carcinoma of colon and rectum: a prospective
case-control study.
AB - BACKGROUND AND OBJECTIVES: The clinical meaning of mucinous type of colonic and
rectal carcinoma is still controversial. We used clinicopathological and follow
up data prospectively recorded for our series of colon and rectum cancer to
compare 2 matched groups of mucinous and nonmucinous cancer patients. METHODS:
Two-hundred-forty-eight patients operated for colon and rectum cancer between
January 1986 and January 1997 were considered. Thirty-six patients showed
mucinous pattern on histologic examination but only 29 (11.7%) had more than 50%
of mucin-secreting acini and could be classified as mucinous type. The 29
mucinous cancer patients were compared with 212 nonmucinous cancer patients to
evaluate differences in epidemiological and clinical features. A control group
from the nonmucinous patients was sorted by matching for age, sex, location, and
Dukes stage. RESULTS: In the case-control groups, survival was better for
nonmucinous than for mucinous tumours. Many of the epidemiological findings
already observed for mucinous carcinoma were also confirmed. CONCLUSIONS: The
existence of prognostic, clinical, and epidemiological differences between
mucinous and nonmucinous colorectal carcinoma, together with the preliminary
reports about their difference as to genetic features, could support the
hypothesis that mucinous type is a distinct biological entity.
PMID- 10694642
TI - Internal mammary chain sentinel lymph node identification in breast cancer.
AB - BACKGROUND AND OBJECTIVES: Sentinel lymph node (SLN) biopsy is not usually
performed with respect to the internal mammary lymph node chain. However, the SLN
may be located in the internal mammary chain, particularly with medial lesions.
We carried out this study to investigate whether lymphatic mapping and SLN biopsy
can detect internal mammary involvement in patients with breast cancer. METHODS:
A dye- and gamma probe-guided SLN biopsy was performed in a consecutive series of
41 patients with tumor in situ or clinical stage I or II breast cancer. After the
biopsy, these patients underwent either a modified radical mastectomy or breast
conserving surgery including axillary lymph node dissection. Biopsy of internal
mammary lymph nodes was performed in 19 of these patients. RESULTS: No
involvement of internal mammary lymph nodes was found histologically in 5
patients in whom lymphatic flow or a "hot nodule" in the internal mammary chain
was found using lymphoscintigraphy. Nodal involvement was demonstrated
histologically in only 1 of 5 cases where lymphatic vessels showed dye staining
or faintly stained nodes. Internal mammary lymph node biopsy also was performed
in 14 of 36 patients with neither stained lymphatic vessels or nodes, nor with
lymphatic flow or a hot nodule by lymphoscintigraphy. Nodal involvement was found
histologically in 1 of these patients. CONCLUSION: SLN biopsy guided by lymphatic
mapping is unreliable for identifying metastases to internal mammary lymph nodes.
PMID- 10694643
TI - Clinical importance of late recurrence in soft-tissue sarcomas.
AB - BACKGROUND AND OBJECTIVES: Soft-tissue sarcomas (STS) represent a diverse
histologic group of malignancies at risk for local and distant failure. We
studied the impact of late (5 or more years) vs. early recurrence (less than 5
years) on subsequent outcome. METHODS: Four hundred sixty-eight patients with STS
treated between 1962 and 1992 were evaluated for late (n = 39; 8%) or early (n =
253; 54%) recurrence. Clinical and pathologic factors were reviewed. Survival
data were analyzed by the Kaplan-Meier method and the log-rank test. RESULTS: Of
the 39 patients with a late recurrence (median follow-up 156 months), 18 patients
had local recurrence, 7 patients developed distant recurrence, and 14 patients
had local and distant recurrence. Thirty patients with late local and/or distant
recurrence underwent complete or wide excision (n = 16), amputation (n = 4), or
local resection (n = 10). The overall 5-year survival rate following late
recurrence was 61%. The 5-year overall survival rate was statistically better for
patients with a late local recurrence alone than for patients with distant
failure, 94% vs. 36%, respectively (P = 0.003). Neither the site of the primary
STS, age, primary margin status, nor histology had any effect on subsequent local
or distant failure and subsequent survival. CONCLUSIONS: These data suggest that
an aggressive approach is appropriate in patients who present with late
recurrence (more than 5 years) following treatment of the primary STS. Impressive
survival rates can be achieved in the treatment of local recurrences.
PMID- 10694644
TI - Limb-saving surgery, survival, and prognostic factors for osteosarcoma: the
Hungarian experience.
AB - BACKGROUND AND OBJECTIVES: There are many factors thought to have an influence on
the prognosis of osteosarcoma that have been reported in the literature. Their
significance, however, still remains controversial in most cases. Experience with
osteogenic sarcoma (OS) was reviewed in order to evaluate surgical results and
survival and to determine the prognostic factors. METHODS: Ninety-six patients
with high-grade osteosarcoma of the extremities were treated between 1986 and
1997 in the authors' institution. They were divided into 3 groups: In group I,
all 75 patients with nonmetastatic OS received intensive chemotherapy (high-dose
methotrexate, doxorubicin, ifosfamide, and cisplatin) and underwent surgery. In
group II, 9 patients already had metastases at the time of referral. In group
III, 12 patients received chemotherapy in delayed or suboptimal form. Results and
Conclusions In group I, there were local recurrences in 3 patients (7%) and
metastases in 8 patients (20%) with limb-saving, whereas these numbers were 1
(3%) and 14 (38%) in those who had amputation. The 5-year disease-free survival
(DFS) was 72% and 69% in the limb-saving and amputation groups, respectively. In
groups II and III, 5-year DFS was extremely poor, 10% and 20% only, underlining
the importance of stage and intensity of chemotherapy, respectively. With
univariate analysis, sex, duration of symptoms, and radiographic appearance of OS
had no prognostic value, whereas tumor volume <60 cm(3), wide or radical surgical
margin, distal location of OS, cartilagineous ground substance <20%, and response
to chemotherapy were positive prognostic factors. The last 4 variables maintained
their significance in the multivariate Cox model as well. Age >30 years showed
indirect negative influence on the final outcome through enhanced intolerability
to the drugs and less cooperability of the patients. The results on survival with
limb-saving surgery were well comparable with those of amputation.
PMID- 10694645
TI - Expression of matrix metalloproteinases and the tissue inhibitors of
metalloproteinases and their local invasiveness and metastasis in Chinese human
pancreatic cancer.
AB - BACKGROUND AND OBJECTIVES: The objective was to evaluate the potent role of
matrix metalloproteinases(MMPs) and the tissue inhibitors of
metalloproteinases(TIMPs) in processes leading to metastasis and local
invasiveness of Chinese human ductal adenocarcinomas of the pancreas. We also
evaluated a possible biological association between the gene expression and
clinical manifestations. METHODS: Northern blot and in situ hybridization have
shown MMP and TIMP gene expression in the pancreas and alterations associated
with neoplastic transformation. Fifteen cases of surgical pancreatic specimens
were examined, using cDNA probes to MMP2, MMP9, and TIMP1. Findings were
correlated with the size of tumor section, CA19-9, pathological classification,
thrombosis, and infiltration of capsule and lymphonoids. RESULTS: Increased
levels of the mRNA of MMP2, MMP9, and TIMP1 genes, MMP2 approximately MMP9/= 0.70. RESULTS: Six patients (50%) demonstrated MIN for at least 1 locus, and
2 patients demonstrated loss of heterozygosity (LOH) for at least 1 locus. Only 1
individual's chordoma manifested microsatellite instability (MIN) and loss of
heterozygosity (LOH). Another patient manifested no MIN but LOH at 9p and 18q.
Interestingly, this individual had the most aggressive clinical cancer course,
presenting with lymph node metastasis and succumbing to widespread metastatic
disease. CONCLUSIONS: Chordomas can be added to the list of malignancies
demonstrating MIN. LOH may prove to portend a worse prognosis than MIN when more
tumors are examined.
PMID- 10694647
TI - Clinical significance of retinoblastoma protein (pRB) expression in esophageal
squamous cell carcinoma.
AB - BACKGROUND AND OBJECTIVES: The goal was to evaluate the clinicopathological
significance of retinoblastoma gene product (pRB) expression in esophageal
squamous cell carcinoma. METHODS: We investigated abnormal pRB expression in
tumors in 191 patients using an immunohistochemical method in conjunction with
anti-RB protein antibody. Surgically resected esophageal squamous cell carcinomas
were examined by immunohistochemical analysis for altered pRB expression.
RESULTS: Decreased pRB nuclear staining indicating loss of RB function occurred
in 82 (43%) of the cases studied. The incidence of decreased pRB expression was
higher in tumors with invasion to the adventitia (50%) than in tumors without
invasion to the adventitia (33%, P = 0.0188). In addition, the incidence of
decreased pRB expression was higher in tumors with lymph node metastasis (50%)
than in those without (34%, P = 0.0346). The 3-year survival rates of 82 patients
who had tumors with decreased pRB expression (30%) was significantly lower than
that of 109 patients who had tumors with normal pRB expression (52%, P = 0.0032).
However, in the multivariate survival analysis, pRB expression was not an
independent prognostic factor for patients with esophageal squamous cell
carcinoma. CONCLUSIONS: Abnormal pRB expression appears to be closely associated
with tumor development. However, the existence of tumors with hyperphosphorylated
RB protein (inactivated form) in pRB-positive tumors, such as those in the
present study, should be considered. Thus, discrimination of this
hyperphosphorylated form of RB protein from the unphosphorylated RB protein is
needed.
PMID- 10694648
TI - Transarterial chemoembolization for inoperable hepatocellular carcinoma and
postresection intrahepatic recurrence.
AB - BACKGROUND AND OBJECTIVES: The role of transarterial chemoembolization (TACE) for
inoperable hepatocellular carcinoma (HCC) has remained controversial, and its
efficacy for postresection intrahepatic recurrence has not been fully assessed. A
study was performed to evaluate the treatment results and prognostic factors of
TACE treatment in these patients. METHODS: Clinicopathologic data and treatment
results of 384 patients with inoperable HCC and 100 patients with postresection
recurrent HCC treated with TACE were collected prospectively and analyzed.
RESULTS: TACE was associated with an overall treatment morbidity rate of 23%
(112/484) and mortality rate of 4.3% (21/484). A particularly high mortality rate
of 20% (9/45) was observed among patients with tumors > 10 cm and pretreatment
serum albumin level = 35 g/L. The overall 1-year, 3-year, and 5-year survival
rates from the time of first TACE treatment were 49%, 23%, and 17% respectively.
Tumor size = 10 cm and serum albumin level > 35 g/L were independent favorable
prognostic factors. TACE in patients with postresection recurrent HCC was
associated with less morbidity, mortality, and a better survival outcome compared
with patients with primary inoperable HCC, but this was largely related to
smaller tumor size and better liver function in the former group at the time of
TACE treatment. CONCLUSIONS: TACE in patients with inoperable HCC was associated
with significant morbidity and mortality, and the survival benefit was limited.
Better patient selection in terms of tumor size and liver function may improve
treatment results. Patients who have a tumor > 10 cm and poor liver function
(serum albumin = 35 g/L) may not be suitable candidates for TACE treatment.
PMID- 10694649
TI - Continent gastrostomy.
PMID- 10694650
TI - Hemicorporectomy.
AB - In hemicorporectomy, or translumbar amputation, the bony pelvis, pelvic contents,
lower extremities, and external genitalia are removed following disarticulation
of the lumbar spine and transection of the spinal cord. Malignancies of the
pelvic organs, skin, or musculoskeletal structures, usually locally advanced, may
be indications for hemicorporectomy. The absence of systemic metastasis must be
demonstrated before considering hemicorporectomy. Sacral decubitus ulcers and
other complications of paraplegia represent the most frequent benign indications.
Hemicorporectomy is a complex, multistep procedure with significant physiologic
and psychologic implications. Postoperative morbidity and mortality rates are
high, partly because of the complexity of the procedure itself and partly due to
the underlying disease. Detailed planning, from preoperative evaluation to
rehabilitation, is the key to a successful outcome. The procedure may be carried
out in one stage or in multiple stages, depending on the clinical circumstances.
Multidisciplinary collaboration of many health care professionals should be part
of the planning process and must be carefully coordinated. Postoperative
management requires particular attention to fluid replacement, temperature
control, and pulmonary care. Posthospitalization rehabilitation includes the
design and construction of a bucket prosthesis. Long-term management issues
involve hypertension, weight gain, temperature control, stoma management, and
skin care.
PMID- 10694651
TI - Commentary
PMID- 10694652
TI - Correlation of c-fos, p53, and PCNA expression with treatment outcome in
osteosarcoma.
PMID- 10694658
TI - Guest editorial.
PMID- 10694659
TI - Successful preimplantation genetic diagnosis for sex Link Lesch--Nyhan Syndrome
using specific diagnosis.
AB - Lesch-Nyhan syndrome (LN) is a severe X-linked recessive disorder caused by a
deficiency of the enzyme hypoxanthine phosphoribosyl transferase (HRT). Clinical
features displayed by affected boys are particularly severe and disturbing and
include hyperuricaemia, Characteristic neurological features including self
mutilation, choreothetosis, spasticity and mental retardation. A couple with a
boy diagnosed with LN and a history of pregnancy termination was referred to the
Hammersmith Hospital. Their affected son was born in 1982 after an uncomplicated
pregnancy and vaginal delivery. Eight subsequent pregnancies had been
unsuccessful. There were five therapeutic terminations and three spontaneous
abortions, one at least directly caused by the sampling procedure during
amniocentesis. From 1989 to 1991 two unsuccessful preimplantation genetic
diagnosis (PGD) cycles by sexing were performed by DNA amplification. The
mutation was characterized and a nested PCR protocol was designed which allowed
the efficient amplification of the affected loci followed by the detection of the
mutant allele by restriction digestion. Three PGD cycles were performed using
this specific diagnostic test before a successful pregnancy was achieved
resulting in the birth of a healthy unaffected baby girl.
PMID- 10694680
TI - Screening for trisomy 21 in twin pregnancies in the first trimester using free
beta-hCG and PAPP-A, combined with fetal nuchal translucency thickness.
AB - In the first trimester of pregnancy the biochemical markers free beta-hCG and
pregnancy associated plasma protein-A (PAPP-A) are used for the prenatal
screening of trisomy 21, either alone or in combination with nuchal translucency
(NT) thickness. In this study, I have analysed the distribution of these
biochemical markers in 159 twin pregnancies and compared this with 3466 singleton
pregnancies. On average free beta-hCG values are 2.099 times greater in twins
than in singletons and PAPP-A some 1.86 times greater. The width of the analyte
distribution in twins is very similar to that in singleton pregnancies. Using
statistical modelling techniques I have predicted that at a 5% false positive
rate the detection rate in twins discordant for trisomy 21 will be 52% and in
twins concordant for trisomy 21 will be 55%, if correction for twin pregnancy is
carried out using the 'pseudo risk' approach. The detection rate using
biochemical parameters is less than that achievable for twins using NT (75%).
However, the combination of NT and maternal serum biochemistry will give
detection rates approaching 80%. These rates are some 10% less than in singleton
pregnancies, but nevertheless combining NT and biochemistry will allow high rates
of detection of affected twins with the benefit of ultrasound and NT being able
to specifically locate the affected twin. Twin screening using both modalities
should be considered when introducing first trimester screening.
PMID- 10694681
TI - Serum screening for Down syndrome and adverse pregnancy outcomes: a case
controlled study.
AB - The relationship between adverse perinatal outcomes in women with false positive
biochemical screening test for Down syndrome was investigated in a retrospective
case-controlled study. A cohort of 4000 women who booked for routine antenatal
care and opted for biochemical screening over a 22 month period was obtained. The
pregnancy outcome data of 272 women with a false positive screening test for Down
syndrome (risk >1 in 250) at 15-18 weeks of gestation (study group) were compared
with data from 272 age and gestation matched controls with a negative Down
syndrome screening test from the same population. The frequency of normal and
adverse perinatal outcomes, including pre-eclampsia, isolated intrauterine growth
restriction, spontaneous preterm labour and stillbirth was recorded. The
incidence of adverse pregnancy outcomes was 11.9% in the study group and 8.6% in
the control group. The estimated odds ratio of an abnormal outcome in the study
group was 1.41 (95% CI-0.790, 2.55). The observed difference between proportion
was 0.0324 (95% CI-0.022, 0.083; p=0.40). These data identify no evidence for a
strong association between a false positive Down syndrome screening test result
and subsequent adverse perinatal outcomes in the general population.
PMID- 10694682
TI - Maternal serum second trimester AFP and hCG in pregnancies with placenta previa.
AB - This study was undertaken to investigate the association between placenta previa
and Down syndrome screening analytes-alpha-fetoprotein (AFP) and hCG-during the
second trimester. Measurements of maternal serum AFP and hCG concentrations were
retrospectively analysed in relation to placenta previa in a cohort of 46
consecutive singleton pregnancies affected by placenta previa from January 1993
through December 1997 at the University Hospital of Kuopio, Finland, and then
compared with those in healthy singleton control pregnancies (N=9560) from the
same clinic over the same period of time. Geometric means of maternal serum AFP
and hCG concentrations in pregnancies with placenta previa were 1.13 and 0. 85
multiples of the median (MoM), respectively. The mean maternal age was higher in
the subjects than in the controls (30.9 years compared with 28.8 years) (p<0.01).
In relation to Down syndrome risk assessment, the pattern of the two markers
together with maternal age indicated high risk as often in the study subjects as
in the controls. Even though the maternal serum AFP and hCG differences were not
statistically significant, they may be of some clinical importance, and further
studies are needed to evaluate whether placental site should be taken into
account in maternal serum screening.
PMID- 10694683
TI - Common trisomy mosaicism diagnosed in amniocytes involving chromosomes 13, 18, 20
and 21: karyotype-phenotype correlations.
AB - Karyotype-phenotype correlations of common trisomy mosaicism prenatally diagnosed
via amniocentesis was reviewed in 305 new cases from a collaboration of North
American cytogenetic laboratories. Abnormal outcome was noted in 10/25 (40%)
cases of 47,+13/46, 17/31 (54%) cases of 47,+18/46, 10/152 (6.5%) cases of
47,+20/46, and in 49/97 (50%) cases of 47,+21/46 mosaicism. Risk of abnormal
outcome in pregnancies with less than 50% trisomic cells and greater than 50%
trisomic cells were: 26% (4/15) versus 60% (6/10) for 47,+13/46, 52% (11/21)
versus 75% (6/8) for 47,+18/46, 4.5% (6/132) versus 20% (4/20) 47,+20/46, and 45%
(27/60) versus 59% (22/37) for 47,+21/46. Phenotypically normal liveborns were
observed with mean trisomic cell lines of 9.3% for 47,+13/46, 8.6% for 47,+18/46,
27% for 47, +20/46, and 17% for 47,+21/46. Cytogenetic confirmation rates were
46% (6/13 cases) for 47,+13/46 mosaicism, 66% (8/12 cases) for 47, +18/46, 10%
(10/97 cases) for 47,+20/46, and 44% (24/54 cases) for 47,+21/46. There were
higher confirmation rates in pregnancies with abnormal versus normal outcome: 50%
versus 44% for 47,+13/46 mosaicism, 100% versus 33% for 47,+18/46, 66% versus 7%
for 47, +20/46, and 55% versus 40% for 47,+21/46. Repeat amniocentesis is not
helpful in predicting clinical outcome. It may be considered when there is
insufficient number of cells or cultures to establish a diagnosis. Fetal blood
sampling may have a role in mosaic trisomy 13, 18, and 21 as the risk for
abnormal outcome increases with positive confirmation: 1/5 (20%) normal cases
versus 5/8 (62%) abnormal cases. High resolution ultrasound examination(s) is
recommended for clinical correlation and to facilitate genetic counselling.
PMID- 10694684
TI - Analysis of uncultured amniocytes by comparative genomic hybridization: a
prospective prenatal study.
AB - Comparative genomic hybridization (CGH) is a new molecular cytogenetic technique
which can detect and map whole and partial aneuploidies throughout a genomic
specimen DNA without culturing specimen cells. Thus, CGH may be used as a
comprehensive and rapid screening test in prenatal unbalanced chromosomal
abnormalities detection. We report the results of the first prospective study to
evaluate the use of the CGH technique on uncultured amniocytes. Seventy-one
amniotic fluid samples, obtained by transabdominal amniocentesis between the 14th
and 35th weeks of gestation, were simultaneously investigated using CGH and
conventional cytogenetics. Amniocentesis were done for advanced maternal age
(21.1%), fetal ultrasound anomalies (73.3%) and high level of biochemical markers
in maternal serum (5.6%). Sixty-six (93%) informative results were generated on a
total of 71 analysed specimens. Fifty-nine samples were reported as disomic for
all autosomes with a normal sex chromosome constitution using CGH and
conventional cytogenetics. Among them, three pericentromeric chromosomal
inversions were undetected by CGH analysis. Seven numerical aberrations were
characterized, including one case of trisomy 13, one case of trisomy 18 and five
cases of trisomy 21. Advantages and limitations of CGH for a rapid prenatal
screening of unbalanced chromosomal aberrations are discussed.
PMID- 10694685
TI - Haplotype association and mutation analysis of the transglutaminase 1 gene for
prenatal exclusion of lamellar ichthyosis.
AB - Lamellar ichthyosis (LI) is an autosomal recessive keratinization disorder of the
skin. Genetic heterogeneity has been shown for the disease and there is evidence
for the involvement of the transglutaminase 1 (TGM1) gene on chromosome 14q11. We
have previously identified chromosome 14q11 haplotypes associated with ichthyosis
in the Norwegian population. In this paper we describe antenatal exclusion of
ichthyosis in two Norwegian families by chromosome 14q11 haplotype association
and direct mutation analysis. In one pregnancy, the 11-week old fetus at risk for
LI was found to share only one disease-associated haplotype. A subsequent
mutation analysis of the TGM1 gene in fetal DNA revealed that the fetus carried a
novel 3795A-->T transversion. The affected proband was compound heterozygous for
the mutations 3795A-->T and 3239G-->C resulting in an Asp430Val and a Val379Leu,
respectively. In another LI family, the 11-week old fetus was found to be
heterozygous for the 14q11 haplotype associated with the disease. Subsequent
mutation analysis revealed that the fetus was heterozygous for the 2526A-->G
transition in the splice site of intron 5 whereas the proband was homozygous for
the same mutation. Our results show that haplotyping can be a useful tool for
prenatal diagnosis in diseases with genetic heterogeneity.
PMID- 10694686
TI - Characterization and clinical implications of marker chromosomes identified at
prenatal diagnosis.
AB - Eighteen fetuses with marker chromosomes were detected at diagnostic
amniocentesis in our laboratory among 15 781 amniocentesis samples. Using
combined approaches, conventional cytogenetics including special stain techniques
and fluorescence in situ hybridization (FISH), we successfully characterized 15
of them, which assisted subsequent genetic counselling. Six marker chromosomes
were of sex chromosome origin, each of which substituted a missing sex
chromosome, and 12 were supernumerary marker chromosomes (SMCs). Nine of the SMCs
were proven to be of autosomal origin. Of those autosomal SMCs, five originated
from chromosome 15, two from chromosome 18, one from chromosome 12 and one from
chromosome 1. Among 16 marker chromosomes with adequate follow-up information,
50% were benign including four sex chromosome markers and four autosomal markers.
Two thirds of de novo marker chromosomes were associated with abnormal outcomes,
while all inherited ones were benign regardless of their parental origin. Our
study demonstrated that molecular characterization of prenatal marker chromosomes
is of great significance in facilitating phenotype-genotype correlation.
PMID- 10694687
TI - Inherited interstitial deletion of chromosomes 5p and 16q without apparent
phenotypic effect: further confirmation.
AB - We describe two families in which an inherited interstitial deletion is present
without apparent associated phenotypic abnormalities. The first deletion was
discovered in a 19-year-old male with a previously diagnosed peroxisomal
disorder. High-resolution chromosome analysis was interpreted as
46,XY,del(5)(p14.1p14.3). The patient's phenotypically normal mother had the same
interstitial deletion. Chromosome 5p14 deletion has been reported in a three
generation family without phenotypic anomalies. We hypothesize that the affected
son's phenotype may be coincidental or represent unmasking of an autosomal
recessive peroxisomal disorder in the deleted region. The second interstitial
deletion was detected by amniocentesis for advanced maternal age. High-resolution
chromosome analysis was interpreted as 46,XX,del(16)(q13q22). The same deletion
was found in the healthy mother and a normal brother. The pregnancy was carried
to term and resulted in the birth of a normal girl. We report these cases as
further evidence that rare, unbalanced deletion of specific chromosomal regions
may result in no phenotypic effect. Consequences may result from expression of an
autosomal recessive disorder on the homologous chromosome. Identification of such
deletions is especially important for prenatal diagnosis and genetic counselling.
PMID- 10694688
TI - Prenatal diagnosis and management of orofacial clefts
PMID- 10694689
TI - Prenatal diagnosis of a fetus with a cryptic translocation 4p;18p and Wolf
Hirschhorn syndrome (WHS).
AB - Wolf-Hirschhorn Syndrome (WHS) is caused by distal deletion of the short arm of
chromosome 4 and is characterized by growth deficiency, mental retardation, a
distinctive, 'greek-helmet' facial appearance, microcephaly, ear lobe anomalies,
and sacral dimples. We report a family with a balanced chromosomal translocation
4;18(p15.32;p11.21) in the father and an unbalanced translocation resulting in
partial monosomy 4 and partial trisomy 18 in one living boy and a prenatally
diagnosed male fetus. Both showed abnormalities consistent with WHS and had in
addition aplasia of one umbilical artery. Karyotyping of another stillborn fetus
revealed a supernumerary derivative chromosome der(18)t(4;18)(p15.32;p11.21) of
paternal origin and two normal chromosomes 4. The umbilical cord had three normal
vessels. A third stillborn fetus with the same balanced translocation as the
father had a single umbilical artery and hygroma colli.
PMID- 10694690
TI - Dicentric marker derived from chromosome 22 associated with mild clinical signs:
a case report.
AB - Amniocentesis performed after 24 weeks' gestation following ultrasonographic
diagnosis of isolated unilateral hydronephrosis showed a de novo extra
structurally abnormal chromosome in all cells examined. A combination of
conventional and molecular cytogenetic techniques characterized the supernumerary
marker as a dicentric and bisatellited marker derived from chromosome 22. At
birth the infant presented hypoplasia of the right kidney, hearing loss on the
left side and bilateral preauricular pits and skin tags. At three years, growth
and neurological development were normal.
PMID- 10694691
TI - Relative efficiency of FISH on metaphase and interphase nuclei from non-mosaic
trisomic or triploid fibroblast cultures.
AB - Chromosome specific probes that are used in interphase fluorescence in situ
hybridization (FISH) analysis are usually tested on disomic control samples. When
used for preimplantation or prenatal diagnosis the aim is to detect aneuploidy,
most frequently trisomy. In this study, skin fibroblast cultures from non-mosaic
trisomic and triploid fetuses were analysed by FISH to assess probe efficiency
regarding interphase detection of trisomy. Skin fibroblast cultures were used
because they are considered to be stable in culture. FISH experiments were
performed using centromeric probes for chromosomes X, Y, 18 and locus specific
probes for chromosomes 13 and 21. In metaphase nuclei, the expected signals were
found in 100% of at least 30 metaphases counted on each sample and this also
confirmed non-mosaicism in agreement with conventional karyotyping of the
fetuses. On interphase nuclei, however, only 80-89% of nuclei per population
displayed the expected signals for autosomal probes and 90% for probes for the
sex chromosomes. For each probe, a range of percentages was obtained that can be
regarded as indicative of non-mosaic trisomy in uncultured specimens. In the case
of prenatal samples, the expected presence of maternal cells may lead to a
lowering of the threshold for a trisomic diagnosis. In the case of
preimplantation diagnosis, the accuracy can be improved by the use of two probes
per chromosome or by the analysis of two cells from each embryo.
PMID- 10694692
TI - Prenatal diagnosis of abdominal enteric duplications.
AB - Alimentary tract duplications are rare congenital malformations with few reports
of the antenatal sonographic appearance. Early diagnosis is of paramount
importance to prevent complications. We present a case of a cystic gastric
duplication diagnosed antenatally at 31 weeks' gestation, which was treated
successfully. Simultaneously, we review all published cases of prenatally
diagnosed enteric duplications.
PMID- 10694693
TI - Plasma measurement of 7-dehydrocholesterol to detect carriers of Smith-Lemli
Opitz syndrome.
PMID- 10694694
TI - Maternal age-specific rates of Down syndrome used in serum screening are biased
low.
PMID- 10694695
TI - A false positive diagnosis of conjoined twins in a triplet pregnancy: pitfalls of
first trimester ultrasonographic prenatal diagnosis.
PMID- 10694696
TI - Current awareness in prenatal diagnosis.
PMID- 10694697
TI - Measurement of N-methyl-2-pyridone-5-carboxamide in urine by high performance
liquid chromatography.
AB - We have previously described a simple and reproducible method for the measurement
of nicotinamide and its major metabolite N-methyl-2-pyridone-5-carboxamide (2
pyr) in human plasma. We now describe a low-cost high-throughput method for
measurement of urinary 2-pyr, and demonstrate that Isolute C18 bulk can replace
use of the column to clean up the samples prior to injection into the HPLC
apparatus. Using a standard curve together with an internal standard for each
sample, with mean recovery of 2-pyr greater than 95%, the assay has proved
reproducible, with considerable savings in cost and time. The principal
advantages of this method are the rapid column clean up of samples prior to
injection and the simple but effective methodology.
PMID- 10694698
TI - Determination of saccharides in sake by high-performance liquid chromatography
with polarized photometric detection.
AB - A high-performance liquid chromatographic method has been developed for the
determination of saccharides in sake, an alcoholic beverage brewed from rice.
Saccharides in sake were separated on a normal phase (carbamoyl bonded silica)
column using a linear gradient elution of water in acetonitrile. Seven
saccharides, glucose, maltose, isomaltose, maltotriose, panose, isomaltotriose
and ethyl alpha-D-glucoside, were determined by a polarized photometric detector.
Unidentified peaks suggesting saccharides with polymerization degrees over 4 were
also observed. The proposed method did not require any sample clean-up treatment.
As an application, saccharide compositions in various kinds of sake were
compared.
PMID- 10694699
TI - Development of a sensitive liquid chromatography-electrospray ionization mass
spectrometry method for the measurement of KW-5139 in rat plasma.
AB - A sensitive method for the determination of a prokinetic peptide, KW-5139
(Leu(13)-motilin), in rat plasma has been developed utilizing liquid
chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). KW-5139 was
separated by reversed-phase HPLC, with a mixture of 75 mM ammonium formate (pH
3.0) and acetonitrile (4:1, v/v), and monitored by single ion recording (SIR)-ESI
MS at m/z 894 ([M+3H](3+)). Simple protein precipitation and the LC-ESI-MS
analysis allowed the determination of KW-5139 in rat plasma with the mean
precision and accuracy at the lower limit of quantitation (LLOQ, 0.5 ng/mL) of
5.7 and 11.2%, respectively. The method was applied to the monitoring of the
plasma time-concentration profile of KW-5139, intravenously administered to rats
at a dose of 1 microg/kg.
PMID- 10694700
TI - HPLC-fluorescence determination of equilin and equilenin in postmenopausal
women's urine.
AB - A high-performance liquid chromatographic (HPLC) method with fluorescence
detection (lambda(ex) = 280 nm; lambda(em) = 410 and 312 nm) in combination with
a post-column on-line photochemical derivatization is described for the
determination of equilin and equilenin in urine from normal postmenopausal women
after therapy with conjugated oestrogens. The column effluents were subjected on
line to UV irradiation (254 nm) and the photo-induced modifications were useful
for the identification of the analytes. The conjugated (sulphate and glucuronide)
forms were analysed after enzymatic or chemical hydrolysis and extracted with
chloroform. Solid-phase extraction using strong anion-exchange sorbent was
applied to the analysis of unconjugated oestrogen fraction to obtain a practical
and reliable sample clean-up. The HPLC separations were achieved using ODS
columns with a mobile phase consisting of 0.05 M triethylamine phosphate buffer
(pH 4.0)-acetonitrile (64:36, v/v) at a flow rate of 1.0 mL/min. The method was
accurate and reproducible; for the equilin and equilenin separation isocratic
conditions were satisfactory, allowing a sensitive detection in urine samples
with a detection limit of about 50 fmol for equilin (lambda(ex) = 280 nm;
lambda(em) = 312 nm, after photoderivatization) and 10 fmol for equilenin
(lambda(ex) = 280 nm; lambda(em) = 410 nm).
PMID- 10694701
TI - Development of a method for the determination of danofloxacin in plasma by HPLC
with fluorescence detection.
AB - A simple and sensitive HPLC method has been developed for the determination of
danofloxacin (DAN) in plasma. Sample preparations were carried out by adding
phosphate buffer (pH 7.4, 0.1 M), followed by extraction with trichloromethane.
DAN and the internal standard, sarafloxacin (SAR), were separated on a reversed
phase column, and eluted with aqueous solution-acetonitrile (80:20 v/v). The
fluorescence of the column effluent was monitored at lambda(ex) = 338 and
lambda(em) = 425 nm. The retention times were 2.80 and 4. 40 min for DAN and SAR,
respectively. The method was shown to be linear from 1 to 1500 ng/mL (r(2) =
0.999). The detection and quantitation limit were 1 and 5 ng/mL, respectively.
Mean recovery was determined as 80% by the analysis of plasma standards
containing 150, 750 and 1500 ng/mL. Inter- and intra-assay precisions were 4.0%
and 2.4%, respectively.
PMID- 10694702
TI - A rapid and sensitive method for the quantification of ganciclovir in plasma
using liquid chromatography/selected reaction monitoring/mass spectrometry.
AB - A method using reversed-phase liquid chromatography coupled with electrospray
ionization and selected reaction monitoring mass spectrometry has been developed
for the quantitative analysis of ganciclovir in rat plasma. Acyclovir, a
structurally related analog of ganciclovir, was used as the internal standard. A
small volume of plasma (50 microL) was spiked with the internal standard and
plasma proteins were precipitated by methanol. The supernatant was dried under
nitrogen, and then reconstituted in water. The use of liquid
chromatography/selected reaction monitoring/mass spectrometry effectively
eliminated potential interference from endogenous constituents in the plasma.
This highly selective and sensitive method made it possible to analyze plasma
ganciclovir with a lower limit of quantitation of 10 ng/mL. The assay was
reproducible and linear in the range 10-10,000 ng/mL. The precision and accuracy
values were in the range 2.0-6.9% and 89.0-109.6%, respectively. The analyte
recovery was greater than 88%. This method was successfully used to monitor the
pharmacokinetic profile of ganciclovir in normal rats following intraperitoneal
administration of the drug.
PMID- 10694703
TI - Comparative analytical quantitation of clenbuterol in biological matrices using
GC-MS and EIA.
AB - A simple and sensitive procedure utilizing GC-MS for the identification and
quantitation of clenbuterol in biofluids and tissues is described. This improved
method utilizes trimethylboroxine for the derivatization of clenbuterol, requires
only 1 mL/g of biological sample, and most importantly does not require an extra
cleaning step for urine specimens prior to extraction. Linear quantitative
response curves have been generated for derivatized clenbuterol over a
concentration range of 5-200 ng/mL. The extraction efficiency at four
representative points of the standard curve exceeded 90% in both specimen types
(plasma and urine). Linear regression analyses of the standard curve in both
specimen types exhibited correlation coefficients ranging from 0.997 to 1.000.
The Limit of detection (LOD) and Limit of quantitation (LOQ) values for plasma
specimens were determined to be 0.5 and 1.5 ng/mL respectively. For urine
specimens, LOD and LOQ values were 0.2 and 0.7 ng/microL respectively. Percentage
recoveries ranged from 91 to 95% for urine and 89 to 101% for plasma. Precision
and accuracy (within-run and between-run) studies reflected a high level of
reliability and reproducibility of the method. In addition to its reliability,
sensitivity and simplicity, this modified procedure is more efficient and cost
effective, requiring less time, only 1 mL of sample, and minimal amounts of
extraction solvents. The applicability of the method for the detection and
quantitation of clenbuterol in biological tissues of rats treated with the drug
was demonstrated successfully. For comparative analysis of clenbuterol in plasma
and liver samples, both GC-MS and enzyme immunoassay (EIA) methods are found to
be suitable. Due to potential antibody-cross reactivity with EIA, the GC-MS
method is the method of choice for most samples because of its specificity.
However, the EIA method is considered the method of choice for analysis of
clenbuterol found in concentrations below the limits of quantitation by GC-MS due
to its sensitivity.
PMID- 10694704
TI - Simultaneous quantitation of d7-nefazodone, nefazodone, d7-hydroxynefazodone,
hydroxynefazodone, m-chlorophenylpiperazine and triazole-dione in human plasma by
liquid chromatographic-mass spectrometry.
AB - A rapid and sensitive LC-MS assay was developed and validated for the
simultaneous determination of d7-nefazodone (d7-NEF), nefazodone (NEF), d7
hydroxynefazodone (d7-OH-NEF), hydroxynefazodone (OH-NEF), m
chlorophenylpiperazine (mCPP), and triazole-dione (Dione) in human plasma using
trazodone (TRZ) as the internal standard (IS). A 0.1 mL aliquot of the plasma
sample was precipitated with 0.1 mL of acetonitrile and vortexed for 2 min. After
centrifugation, 50 microL of supernatant was mixed with 100 microL of 10 mM
ammonium formate (pH = 4.0), and a 50 microL aliquot was injected onto a BDS
Hypersil C18 column at a flow rate of 0.3 mL/min. The mobile phase consisting of
10 mM ammonium formate (pH = 4) and acetonitrile, 55:45 v/v, was used in an
isocratic system. The mass spectrometer was programmed to admit the protonated
molecules at m/z 477.2 (d7-NEF), 493.3 (d7-OH-NEF), 197.0 (mCPP), 372.0 (IS),
470.4 (NEF), 458.0 (Dione) and 486.2 (OH-NEF). Standard curves were linear (r(2)
>/= 0.994) over the concentration range of 4-1000 ng/mL for Dione and 2-500 ng/mL
for all other analytes. The lowest standard concentrations were the lower limits
of quantitation for each analyte. The mean predicted quality control
concentrations for all analytes deviated by less than 14.3% from the
corresponding nominal values; the intra-assay and inter-assay precisions of the
assay for all analytes were within 10.5% relative standard deviation. All
analytes including the internal standard were stable in the injection solvent at
room temperature for at least 24 h. The extraction recovery of the various
analytes ranged from 79.2 to 109.1%. The validated assay was applied to the
analysis of clinical samples obtained from a human subject who simultaneously
received d7-NEF and NEF orally.
PMID- 10694705
TI - Determination of phenobarbital in plasma by micellar liquid chromatography.
AB - A new liquid chromatographic procedure for the determination of phenobarbital in
plasma samples is described. The proposed system uses a Spherisorb octadecyl
silane ODS-2 C(18) analytical column, a guard column of similar characteristics,
and a 0.03 M CTAB-3% 1-propanol at pH 7 mobile phase. The UV detector was set at
250 nm. Butabarbital was used as internal standard. Sample preparation only
required the addition to the plasma samples of a 0.1 M SDS solution at pH 3 and
centrifugation before injection into the chromatographic system. The limit of
detection was 0.83 microg/mL of phenobarbital in plasma samples. The coefficients
of variation were lower than 7. 5%.
PMID- 10694706
TI - Sensitive determination of anandamide in rat brain utilizing a coupled-column
HPLC with fluorimetric detection.
AB - A fluorimetric determination method for N-arachidonoylethanolamine (anandamide)
was developed using a precolumn fluorescence derivatization followed by coupled
column high-performance liquid chromatography (HPLC). Anandamide extracted from
the rat brain tissue was derivatized with 4-N-chloroformylmethyl-N-methylamino-7
N, N-dimethylaminosulfonyl-2,1,3-benzoxadiazole (DBD-COCl), purified by a solid
phase extraction (Emporetrade mark), and assayed by the coupled-column HPLC. The
HPLC consisted of phenyl (100 x 4.6 mm i.d. ) and octadecylsilica columns (250 x
4.6 mm i.d.), both connected by a six-port valve. The concentration of anandamide
in rat brain was 3. 37 +/- 0.73 pmol/g with 6.47 and 3.57% of intra- and inter
day precisions, respectively. Using this method, we investigated the alteration
of anandamide concentration in rat brain 30 min after administration of
anandamide (2 mg/kg, i.p.) to rats pretreated with or without
phenylmethylsulfonyl fluoride (PMSF; 30 mg/kg, i.p.), an inhibitor of
amidohydrolase. In rats pretreated with PMSF, the brain concentration of
anandamide was approx. 16-fold higher than that of rats without PMSF (p < 0.01).
PMID- 10694707
TI - Enantiomer separation of pharmaceuticals by capillary gas chromatography with
novel chiral stationary phases.
AB - New chiral stationary phases of polydimethylsiloxane anchored with (S)-(-)-t
leucine derivatives were provided for use in enantiomer separation of
pharmaceuticals by capillary gas chromatography. Fifteen pharmaceuticals were
separated into their enantiomeric pairs by converting them into
pentafluoropropionyl and heptafluorobutyryl derivatives. The separation factor
and resolution obtained from the new phases were superior to those from the
conventional Chirasil-Val capillary column.
PMID- 10694708
TI - Determination of resibufogenin and cinobufagin in heart-protecting musk pill by
HPLC.
AB - A high-performance liquid chromatographic (HPLC) method for the simultaneous
determination of resibufogenin and cinobufagin in traditional Chinese medicine
(heart-protecting musk pill, shexiang baoxin wan in Chinese) was developed. A
reversed-phase system with a Hypersil (ODS2) C(18) column and tetrahydrofuran:
methanol: water (8:31:61) mobile phase was employed for the separation of
resibufogenin and cinobufagin. The detection was set at 299 nm and ethinyl
estradiol was chosen as the internal standard. The limit of detection was 1.5 ng
for resibufogenin and 2.0 ng for cinobufagin at a signal-to-noise ratio of 4:1.
It is a rapid, simple and accurate method for quantitative analysis of
resibufogenin and cinobufagin in heart-protecting musk pill.
PMID- 10694709
TI - Fluorescent oxidation products derived from DBD-thiocarbamoyl amino acid in the
modified Edman sequencing analysis.
AB - The fluorescent product obtained by the oxidation of 7-N, N-dimethylaminosulfonyl
4-(2,1,3-benzoxadiazolyl) (DBD)-thiocarbamoyl (TC)-proline with NaNO(2)/H(+) in
the modified Edman sequencing procedure was identified as the corresponding
thiazolyl compound, N-[(8-dimethylaminosulfonyl)thiazolo[5,4,
e]benzo[2,1,3]oxadiazol-5-yl]-L-proline, formed by the attack of the sulfur atom
of the thiocarbamoyl group on the benzofurazan skeleton. The reaction mechanism
for the formation of the fluorescent compound from DBD-TC primary and secondary
amines is also discussed.
PMID- 10694710
TI - Use of leucotomy for intractable anorexia nervosa: a long-term follow-up study.
AB - OBJECTIVE: We studied the long-term outcomes of intractable anorexia nervosa
treated with leukotomy and specialized psychotherapy over 20 years ago. METHOD:
All traceable subjects were interviewed using the Eating Disorders Examination
(EDE) and the Structured Clinical Interview for DSM-III-R (SCID). They also
completed questionnaires. Detailed histories were taken. RESULTS: Four of five
female subjects were traced. Their cases had been severe, with failure of
previous intensive psychotherapy and now with high risk of death from terminal
inanition. One patient had committed suicide, whereas the others enjoyed a
reasonable quality of life. Persistent core psychopathology was evident, but
patients had not succumbed to weight loss. All suffered depression and anxiety
related disorders, but endorsed their treatment, which had allowed sustained
weight gain by release of appetitive behavior, provision of a license to change,
and alleviation of phobic anxiety, allowing psychotherapeutic engagement.
DISCUSSION: We argue that these outcomes are relatively favorable and would not
have been possible without this latter engagement in specialist psychotherapy to
address burgeoning panic at unavoidable weight gain.
PMID- 10694711
TI - Using the eating disorder examination to identify the specific psychopathology of
binge eating disorder.
AB - OBJECTIVE: The clinical features of binge eating disorder (BED) are not well
established. Therefore, a comprehensive assessment of the specific
psychopathology of BED as compared to anorexia nervosa (AN) and bulimia nervosa
(BN) is warranted. This comparison was the aim of the present study. METHOD:
Detailed ratings from an investigator-based interview, the Eating Disorders
Examination (EDE), were compared across three groups of female patients: those
with BED, AN, and BN, as well as normal-weight and overweight control subjects.
RESULTS: When comparing BED to AN and BN, patients with BED had lower levels of
restraint, eating concerns comparable to AN patients but lower than BN patients,
and weight and shape concerns comparable to BN patients but higher than AN
patients. Significantly more eating disorder psychopathology was found for BED
patients as compared to the overweight controls on all bar the EDE restraint
subscale. On the majority of individual EDE items, BED patients' scores were
similar to those of AN and BN patients, including importance of shape and weight
in self-evaluation and preoccupation with shape and weight. No significant
relationship was found between BED patients' degree of overweight and eating
psychopathology. DISCUSSION: Our findings support the status of BED as an eating
disorder and suggest that the elevated EDE scores reflect the combined impact of
being objectively overweight and having disordered cognitions and behaviors about
eating, shape, and weight.
PMID- 10694712
TI - Subthreshold binge eating disorder.
AB - OBJECTIVE: To examine the clinical features of subthreshold binge eating disorder
(BED). METHOD: Participants were recruited directly from the community as part of
an ongoing study of risk factors for BED. Forty-four women with subthreshold BED
were compared with 44 women with BED and 44 healthy controls on demographic
characteristics, body mass index (BMI), eating disorder symptomatology, and
psychiatric distress. Diagnoses were established using the Eating Disorder
Examination (EDE). Participants completed the EDE-Questionnaire, the Brief
Symptom Inventory, and were measured and weighed. RESULTS: Adjusting for
significant group differences in BMI, the two eating disorder groups did not
differ significantly on measures of weight and shape concern, restraint,
psychiatric distress, and history of seeking treatment for an eating or weight
problem. DISCUSSION: Given the importance of diagnostic status for access to
treatment, further evaluation of the severity criterion specified for BED is
needed.
PMID- 10694713
TI - Eating disorders: psyche or soma?
AB - Speculation about the etiology of eating disorders has gone through different
phases, variously favoring familial, organic, and psychosocial factors. Recent
evidence has particularly contributed to our understanding of the organic view.
We review the evidence for an organic contribution to the illness and present a
series of cases in which organic factors were present. The cases illustrate the
complex interaction between biological and psychological factors. In particular,
a growth hormone-producing pituitary adenoma was discovered in a patient
following successful treatment of her bulimia by psychological means alone.
Etiological theories of eating disorders need to encompass both organic and
psychosocial factors, allowed to interact in complex ways. Focusing exclusively
on either aspect is a disservice to our patients.
PMID- 10694714
TI - Perceived expressed emotion in the siblings and parents of hospitalized patients
with anorexia nervosa.
AB - OBJECTIVE: The present study investigated the relationship between the level of
perceived Expressed Emotion (EE) of the siblings and parents of patients
hospitalized with anorexia nervosa and its effect on weight gain and
psychological functioning. METHOD: The Level of Expressed Emotion (LEE) Scale was
administered on admission to 19 patients with anorexia nervosa who completed the
LEE three times so as to identify their perceptions of their relationship with
their closest age sibling, mother, and father. They were also required to
complete the Eating Disorder Inventory 2 (EDI-2). Patients' closest age sibling
completed the Family Attitude Scale (FAS). The patients' body mass index (BMI)
was calculated 6 weeks later, and the EDI-2 readministered. RESULTS: Perceived EE
was not predictive of BMI change after 6 weeks of hospitalization. A composite
perceived family EE score was a significant predictor of change on the
Interpersonal Distrust, Maturity Fears, and Perfectionism subscales of the EDI-2.
DISCUSSION: These findings suggest that patients' perceptions of their
relationships with their closest aged sibling, mother, and father are poor
predictors of weight gain and improvement in psychological functioning following
6 weeks of inpatient treatment.
PMID- 10694715
TI - Interrelationships between the size of the pancreas and the weight of patients
with eating disorders.
AB - OBJECTIVE: Starvation severely affects normal pancreatic function in children
suffering from Kwashiorkor and in animals undergoing food deprivation. This study
examines whether pancreatic size, as determined by ultrasound, is dependent on
starvation or on eating patterns in patients with eating disorders. METHOD: In
109 inpatients with eating disorders, 86 with anorexia nervosa and 23 with
bulimia nervosa, we determined the pancreatic size by means of abdominal
ultrasonography before increase in weight. Twenty-four inpatients with other
psychiatric disorders served as controls. Pancreatic size was defined by the
maximal diameter and the length of the head, the diameter of the head at the
confluence of the splenic and mesenteric veins, and the diameters of the body and
tail. In 41 eating disorder patients, pancreatic size was also measured during
the course of therapy and increase in weight. RESULTS: Pancreatic size correlates
highly with body mass index (BMI). Counteracting actions such as purging do not
seem to influence this pathophysiologic finding. Dystrophy of the pancreas is
reversible in a short period of time. The increase in pancreatic size after
maintenance of a normal eating pattern, however, exceeded the size expected by
regression equation with an increase in the BMI. Pancreatic size seems to
correlate with the actual amount of digested food. The increase in BMI is only an
indicator of food intake. DISCUSSION: Pancreatic size might therefore be useful
for the assessment of normalization of the eating pattern. Future research is
necessary to investigate the impairment of pancreatic function resulting from
dystrophy, the impact of possible pancreatic malfunction on the course of eating
disorders, and the regulatory mechanisms responsible for the change of pancreatic
size.
PMID- 10694716
TI - Nonweight-related body image concerns among female eating-disordered patients and
nonclinical controls: some preliminary observations.
AB - OBJECTIVE: Eating disorders(ED) have been classically associated with a concern
about body shape and size that manifests mainly as an intense fear of weight gain
(DSM-IV criteria). To further examine the nature of the body image disturbance in
ED, we surveyed the prevalence of nonweight-related body image concerns among ED
patients and nonclinical controls. METHOD: We examined 53 women (M +/- SD age:
28.1 +/- 6.8 years) with anorexia nervosa and/or bulimia nervosa (DSM-III-R
criteria) and 73 randomly selected nonclinical women (M +/- SD age: 30.2 +/- 6.6
years) from the community. The participants rated (by checking a "Yes" or "No")
whether they were satisfied with the appearance of the following body regions:
their skin, teeth, jaw, nose, eyes, ears, hair, and height and completed the
Drive for Thinness (DT) and Body Dissatisfaction (BD) subscales of the Eating
Disorders Inventory (EDI). RESULTS: The frequencies of dissatisfaction with the
appearance of various physical attributes among the ED patients versus the
nonclinical controls were as follows: skin: 79.2% vs. 52.1%, p =.002; teeth:
62.3% vs. 39.7%, p =. 012; jaw: 24.5% vs. 9.7%, p =.026; nose: 45.3% vs. 24.7%, p
=.015; eyes: 22.6% vs. 12.3%, p =.12; ears: 20.8% vs. 2.7%, p =.001; hair: 52.8%
vs. 39.7%, p =.14; and height: 28.3% vs. 13.7%, p =.04. As expected, the M +/- SD
DT (EDI): 14.0 +/- 6.1 vs.3.5 +/- 4.6, p <. 0001 and the M +/- SD BD (EDI): 19.7
+/- 5.8 vs. 10.1 +/- 7.3, p <. 0001, were both higher in the ED group.
Furthermore, greater dissatisfaction with nonweight-related body image was
associated with higher DT and BD scores. CONCLUSION: The higher prevalence of
dissatisfaction with appearance of most of the nonweight-related physical
attributes is probably an indication of the core ego deficits that are often
present in ED and an index of the severity of the overall body image disturbance
in these patients, and not indicative of another condition (e.g., body dysmorphic
disorder) as the current nosology (DSM-IV) suggests.
PMID- 10694717
TI - Comparisons of body image dimensions by race/ethnicity and gender in a university
population.
AB - OBJECTIVE: We examined affective and cognitive components of body image related
to physical appearance, weight, and health among 120 university men and women of
three racial/ethnic groups: African American, European American, and Latino/a
American. METHOD: Participants completed a Background Information Sheet, the
Multidimensional Body-Self Relations Questionnaire (MBSRQ), the Body-Esteem Scale
(BES) with additional items, and the Balanced Inventory of Desirable Responding
(BIDR). We tested for effects of race/ethnicity and gender on the body image
measures while controlling for age, body size, social desirability, and
socioeconomic status (SES). RESULTS: African Americans reported greatest body
satisfaction and least overestimation of weight. Latino/a Americans were equal to
or higher than European Americans on all indices. Gender differences occurred on
global body image, weight concerns, fitness, and health. There were no Gender x
Race/Ethnicity interactions. DISCUSSION: This pattern of racial/ethnic and gender
differences shows a need for exploring a wider range of culturally relevant body
image dimensions.
PMID- 10694718
TI - Disordered eating in three communities of China: a comparative study of female
high school students in hong kong, Shenzhen, and rural hunan.
AB - OBJECTIVE: To examine disordered eating and its psychological correlates among
female high school students in three Chinese communities that lay on a gradient
of socioeconomic development in China. METHOD: 796 Chinese students from Hong
Kong, Shenzhen, and rural Hunan completed a demographic and weight data sheet,
the Eating Attitudes Test (EAT-26), a Body Dissatisfaction Scale (BDS), the Beck
Depression Inventory (BDI), and the Rosenberg Self-Esteem Scale (RSES). RESULTS:
Compared to students in Hunan and to a lesser extent students in Shenzhen,
students from Hong Kong were slimmer, but desired a lower body mass index (BMI),
reported more body dissatisfaction, exhibited a more typical EAT-26 factor
structure, scored higher on the "fat concern and dieting" factor, and constituted
more EAT-26 high scorers. Multiple regression analyses indicated that BDS was the
most significant predictor of fat concern at each site, but this effect was
strongest in Hong Kong. Hunan students had significantly higher BDI scores but
lower fat concern than Shenzhen and Hong Kong students. DISCUSSION: The
consistent gradient of fat concern across the three communities gives credence to
the view that societal modernization fosters disordered eating in women, possibly
via the gendered social constraints that accompany it. It is also expressive of
the marked socioeconomic heterogeneity within China nowadays. The predictable
rising rate of eating disorders that follows global change will pose a growing
public health challenge to Asian countries.
PMID- 10694719
TI - Subliminal activation of abandonment- and eating-related schemata: relationship
with eating disordered attitudes in a nonclinical population.
AB - OBJECTIVE: Previous research has demonstrated that subliminal abandonment cues
can facilitate eating behavior. It is believed that such eating is a response to
the activation of specific core schemata. However, the precise nature of those
schemata has not been established. This study examined whether the presentation
of subliminal abandonment and food/shape cues results in the activation of
abandonment-related or food-related schemata. METHOD: Eighty-two women were
exposed to one of three subliminal cues- an abandonment cue ("lonely"), an
appetitive cue ("hungry"), and a neutral cue ("gallery"). They subsequently
completed Stroop tasks to measure activation of relevant schemata. RESULTS:
Subliminal presentation of abandonment cues led to the activation of food- and
shape-related schemata. In contrast, subliminal appetitive cues resulted in an
activation of abandonment-related schemata. CONCLUSIONS: The results show
preliminary support for a multilevel cognitive model, involving indirect links
between subliminal cue type and the activation of eating-related cognitions.
PMID- 10694720
TI - Seasonality of eating pathology on the eating attitudes test in a nonclinical
population.
AB - OBJECTIVE: To determine whether there are seasonal fluctuations in eating
pathology in a nonclinical population. METHOD: The Eating Attitudes Test (EAT)
was completed by 322 subjects during winter and again during summer. Summer and
winter responses were compared to investigate differences in EAT total and
subscale scores and for individual EAT items. Numbers of subjects fluctuating
across the seasons by more than 2 SDs of the cohort's scores were identified.
RESULTS: The cohort showed no significant seasonal change on EAT-40 totals, EAT
26 totals, or within the EAT subscales. There were significant (p <.025) seasonal
fluctuations on four of the EAT-40 questions. For individual respondents, there
was no greater likelihood of scoring significantly higher in the winter than in
the summer. DISCUSSION: Clinically significant seasonal fluctuations in eating
pathology on the EAT did not occur in this nonclinical population. It is
debatable whether items within the EAT which show significant seasonal
fluctuations should be retained or discarded.
PMID- 10694721
TI - The effect of body dissatisfaction on women's perceptions of female celebrities.
AB - OBJECTIVE: Research suggests that media exposure causes some women to feel
heightened dissatisfaction with their body shape. This study attempts to
determine which women are effected as such, by investigating how women feel about
their own bodies and how this effects their perceptions of female celebrities in
the media. METHOD: Undergraduate females (n = 116) were shown one accurate and
six distorted photographs of thin and heavy female celebrities. Each distorted
photograph made the celebrity appear thinner or heavier than actuality.
Participants chose which photograph portrayed each celebrity's true body shape.
Body shape concerns were measured by the Body Shape Questionnaire. RESULTS: Women
concerned about their body shape judged thin celebrities as thinner than
actuality, whereas unconcerned women judged them accurately. Both groups judged
heavy celebrities as heavier than actuality. DISCUSSION: Results suggest certain
women are effected by media exposure due to their own perception of females in
the media. Prevention strategies, and the media's role in body dissatisfaction
and dieting disorders, are discussed.
PMID- 10694722
TI - Multi-impulsivity among bulimic patients in Japan.
AB - OBJECTIVE: Studies in Western world patients suggest the possible existence of a
subgroup of patients with bulimia nervosa (BN) who display multiple problems with
impulsivity, such as suicidal attempts. We assessed impulsive behaviors among BN
patients in Japan to discuss them crossculturally. METHOD: Impulsive behaviors in
64 BN patients were assessed and multi-impulsivity (MI) was defined according to
the definition proposed by Fichter, Quadflieg, and Rief (Psychological Medicine,
24, 591-604,1994). RESULTS: Nineteen patients (30%) met the definition of MI. BN
patients with MI had more severe clinical features, such as concurrent depressive
and anxious symptoms, global functioning, and higher prevalence of borderline
personality disorder than BN patients without MI. DISCUSSION: These results
showed the similarities between BN patients with MI in Japan and those patients
in the Western world in clinical and psychopathological characteristics and a
life-time incidence of each impulsive behavior. These findings may suggest
culturally free bases for linkage between BN and MI.
PMID- 10694723
TI - Personality disorders among subjects recovered from eating disorders.
AB - OBJECTIVE: Personality disorders are common in symptomatic eating disorders
subjects. Because personality symptoms could be exaggerated by malnutrition or
Axis I disorders, we studied women who had recovered from eating disorders for at
least 1 year to see if personality disorder symptoms persisted in the well state.
METHOD: Personality disorders were evaluated in 10 women recovered from anorexia
nervosa (AN), 28 women recovered from bulimia nervosa (BN), and 16 women
recovered from AN and BN, using the Structured Clinical Interview for DSM-III-R
personality disorders. RESULTS: Fourteen of 54 subjects (26%) met the criteria
for at least one personality disorder, such as self-defeating, obsessive
compulsive, or borderline personality disorder. Cluster B personality disorders
were closely associated with bulimic subtypes. CONCLUSIONS: While a recovery from
eating disorders may have an attenuating influence on the symptoms of personality
disorders, such personality disorder diagnoses persist after recovery in some
recovered subjects.
PMID- 10694724
TI - Electrolyte and other blood serum abnormalities in normal weight bulimia nervosa:
evidence for sampling bias.
AB - OBJECTIVE: Sampling bias due to research settings might be responsible for
reported high prevalence rates of electrolyte and serum abnormalities in bulimia
nervosa. The aim of this study was to investigate the prevalence of electrolyte
and other serum abnormalities in bulimia nervosa patients with normal weight
seeking treatment in a community mental health center. METHOD: Diagnostic
evaluations and laboratory tests were done for a consecutive series of 31
patients meeting DSM-III-R criteria for bulimia nervosa. RESULTS: The duration
and clinical severity of the eating disorder were considerable and psychiatric
comorbidity was high. None of the subjects showed electrolyte abnormalities.
Hypomagnesemia was found in 9.7% and hypoalbuminemia in 6.4% of the population.
The severity of the abnormalities was modest. DISCUSSION: The results suggest
that previous reports on electrolyte abnormalities in bulimia nervosa were
affected by sampling bias. Based on the results, there is no indication to
perform routinely laboratory studies in ambulatory patients with normal weight.
PMID- 10694725
TI - Case reports of olanzapine treatment of anorexia nervosa.
AB - Two females with severe anorexia nervosa were treated with olanzapine in open
trials. Olanzapine was tried because it has caused weight gain in other patient
groups. Both anorexic patients had a chronic illness and had failed multiple
other treatments. Olanzapine administration was associated with weight gain and
maintenance as well as reduced agitation and resistance to treatment. These case
histories support further exploration of this class of drugs in anorexia nervosa.
PMID- 10694726
TI - Selected papers from the Oberwolfach Conference on Medical Statistics:
Mathematical Models for Diagnosis and Prognosis. 1997.
PMID- 10694727
TI - Prognosis - what does the clinician associate with this notion?
PMID- 10694728
TI - Prevalence-free utility-respecting summary indices of diagnostic power do not
exist.
AB - One would like to have a ranking method for diagnostic tests that justifiably
makes no assumptions about the local 'disease mix', that is, about the pre-test
probabilities of the diagnostic alternatives. Assuming the simplest possible
clinical context we therefore examine the following question: can a summary index
of diagnostic test performance be devised which is loyal to the expected utility
paradigm and, at the same time, is incidence-free (prevalence-free)? In other
words, regardless of pre-test probabilities, the index should rank rival tests in
a way which agrees with how they might be ranked by expected utility
calculations. From a practical point of view, the answer is negative; it is
proved that such indices do exist, but they necessarily impose a very restrictive
mathematical form on the utility framework and, what is worse, invariably go
against what is medically appropriate by violating a boundedness requirement.
PMID- 10694729
TI - Sample size considerations for the evaluation of prognostic factors in survival
analysis.
AB - When the role of a new prognostic factor is investigated, careful planning of an
appropriate study is required. This includes an assessment of the power of the
study in terms of sample sizes. An adequate analysis of the independent
prognostic effect of a new factor has to be adjusted for the existing standard
factors. With survival time as endpoint this will usually be done with the Cox
proportional hazards model. Sample size and power formulae in survival analysis
have been developed by Schoenfeld for randomized treatment comparisons. In the
analysis of prognostic factors the covariates included are expected to be
correlated with the factor of primary interest. In this situation, the existing
sample size and power formulae are not valid and may not be applied. In this
paper, Schoenfeld's formula is first extended to the situation where a correlated
factor is included in the analysis. The validity of the resulting approximate
asymptotic formula is investigated for its asymptotic behaviour by numerical
integration and for its finite behaviour by simulation. Second, an approximate
formula for sample size and power is provided to detect an interaction between
the interesting and a second correlated factor. This extends the formula for
independent effects. Finally, the approach is illustrated by an example on the
prognostic impact of DNA ploidy and other factors in advanced ovarian cancer.
PMID- 10694730
TI - What do we mean by validating a prognostic model?
AB - Prognostic models are used in medicine for investigating patient outcome in
relation to patient and disease characteristics. Such models do not always work
well in practice, so it is widely recommended that they need to be validated. The
idea of validating a prognostic model is generally taken to mean establishing
that it works satisfactorily for patients other than those from whose data it was
derived. In this paper we examine what is meant by validation and review why it
is necessary. We consider how to validate a model and suggest that it is
desirable to consider two rather different aspects - statistical and clinical
validity - and examine some general approaches to validation. We illustrate the
issues using several case studies.
PMID- 10694731
TI - Tree stability diagnostics and some remedies for instability.
AB - Stability aspects of recursive partitioning procedures are investigated. Using
resampling techniques, diagnostic tools to assess single split stability and
overall tree stability are introduced. To correct for the procedure's preference
for covariates with many unique realizations, corrected p-values are used in the
factor selection component of the algorithm. Finally, methods to stabilize tree
based predictors are discussed.
PMID- 10694732
TI - Regional confidence bands for ROC curves.
AB - The performance of a diagnostic test is characterised by its specificity and
sensitivity. For a quantitative diagnostic test these criteria depend on the
selected cut-off point. The receiver operating characteristic (ROC) curve of a
quantitative diagnostic test is generated by plotting sensitivity against
specificity as the cut-off point runs through the whole range of possible test
values. In practice, the ROC curve is estimated from clinical data. One important
goal is to select an optimal cut-off point. For this purpose the sample
variability has to be taken into account. Recently, Campbell has introduced
nonparametric asymptotic simultaneous confidence bands that are valid for the
whole ROC curve. In this paper a nonparametric asymptotic approach for the
construction of regional confidence bands for ROC curves is proposed. It can be
applied for any specificity interval of interest. Our approach is based on the
asymptotic theory of empirical and quantile processes. To investigate the small
sample properties of the different approaches, a Monte Carlo study was conducted
using normal and log-normal data. A method for sample size calculation is
presented. Finally, the approaches are applied to a tumour marker in the
diagnosis of bone marrow metastases.
PMID- 10694733
TI - Comparison of diagnostic markers with repeated measurements: a non-parametric ROC
curve approach.
AB - In this paper we study a class of non-parametric statistics for comparing
diagnostic markers with repeated measurements. Using adapted definitions of
specificity and sensitivity, we suggest methods to compare the average of
sensitivities across all specificities or a range of specificities. The theory
allows for correlations introduced by the fact that markers may be obtained from
the same patient at multiple visits and that both markers being compared may be
obtained from the same patient. Results of the Monte Carlo simulations and an
example from a breast cancer setting are provided.
PMID- 10694734
TI - Statistical methods for the evaluation of diagnostic measurements concerning
paired organs.
AB - Diagnostic measurements involving paired organs may be modelled using marginal or
conditional approaches. Relevant information could be ignored by using marginal
models with a mean structure not including information from the fellow organ. The
conditional Rosner model can be generalized to a symmetric polychotomous logistic
regression model. The rather strong assumptions of the Rosner model are relaxed
in this symmetric model. The use of the symmetric model is justified by its
relation to discriminant analysis. Additionally, the information of the
diagnostic measurements from the fellow organ is taken into account explicitly.
Furthermore, in case-control studies this approach corresponds to the sampling
scheme. When the status of the fellow organ and the diagnostic measurement of
this organ both are available, a surprising effect may be observed; pathological
values of the diagnostic measurement from the fellow organ decrease the disease
probability of the selected organ. As an example, four different diagnostic
procedures from the Erlangen Glaucoma Registry are investigated.
PMID- 10694735
TI - On the misuses of artificial neural networks for prognostic and diagnostic
classification in oncology.
AB - The application of artificial neural networks (ANNs) for prognostic and
diagnostic classification in clinical medicine has become very popular. In
particular, feed-forward neural networks have been used extensively, often
accompanied by exaggerated statements of their potential. In this paper, the
essentials of feed-forward neural networks and their statistical counterparts
(that is, logistic regression models) are reviewed. We point out that the
uncritical use of ANNs may lead to serious problems, such as the fitting of
implausible functions to describe the probability of class membership and the
underestimation of misclassification probabilities. In applications of ANNs to
survival data, further difficulties arise. Finally, the results of a search in
the medical literature from 1991 to 1995 on applications of ANNs in oncology and
some important common mistakes are reported. It is concluded that there is no
evidence so far that application of ANNs represents real progress in the field of
diagnosis and prognosis in oncology.
PMID- 10694737
TI - Methods of ordinal classification applied to medical scoring systems.
AB - Scoring systems are used in nearly all fields of medicine for evaluation of the
state of a disease. The prediction performance of scoring systems with respect to
an ordinal outcome scale is investigated, based on grouped continuous logistic
models as well as on an extension of the stereotype logistic regression model.
The latter is a canonical approach, which allows assessment of properties of
outcome categories such as partial and total ordering, distinguishability and
allocatability. The approach is applied to a data set of patients with injuries
of the head.
PMID- 10694736
TI - Choice of conditional models in bivariate survival.
AB - We consider bivariate survival problems in which interest is in the conditional
distribution of one survival variable given an uncensored observation of the
other. The work is motivated by an analysis of time to cancer diagnosis then
subsequent survival amongst a group of organ transplant recipients. The effect of
conditioning is illustrated for five standard bivariate models. The consequences
of adopting a misspecified marginal approach in which the conditioning variable
is considered to be a fixed covariate are investigated.
PMID- 10694738
TI - Multi-state models for bleeding episodes and mortality in liver cirrhosis.
AB - Data from a controlled clinical trial in liver cirrhosis are used to illustrate
that multi-state models may be a useful tool in the analysis of data where
survival is the ultimate outcome of interest but where intermediate, transient
states are identified. We compare models for the marginal survival time
distribution with models including transient states, both with respect to their
clinical interpretation and with respect to the precision of survival probability
estimates obtained from the various models.
PMID- 10694739
TI - Identifying and modelling prognostic factors with censored data.
AB - A major issue in the analysis of diseases is the identification and assessment of
prognostic factors relevant to the development of the illness. Statistical
analyses within the proportional hazards framework suffer from a lack of
flexibility due to stringent model assumptions such as additivity and time
constancy of effects. In this paper we use tree-based models and varying
coefficient models to allow for detectability of prognostic factors with possibly
non-additive, non-linear and time-varying impact on disease development.
Questions concerning model and smoothing parameter selection are addressed. An
analysis of a data set of breast cancer patients demonstrates the ability of
these methods to reveal additional insight into the disease influencing
mechanisms.
PMID- 10694740
TI - Statistical models for longitudinal biomarkers of disease onset.
AB - We consider the analysis of serial biomarkers to screen and monitor individuals
in a given population for onset of a specific disease of interest. The biomarker
readings are subject to error. We survey some of the existing literature and
concentrate on two recently proposed models. The first is a fully Bayesian
hierarchical structure for a mixed effects segmented regression model. Posterior
estimates of the changepoint (onset time) distribution are obtained by Gibbs
sampling. The second is a hidden changepoint model in which the onset time
distribution is estimated by maximum likelihood using the EM algorithm. Both
methods lead to a dynamic index that represents a strength of evidence that onset
has occurred by the current time in an individual subject. The methods are
applied to some large data sets concerning prostate specific antigen (PSA) as a
serial marker for prostate cancer. Rules based on the indices are compared to
standard diagnostic criteria through the use of ROC curves adapted for
longitudinal data.
PMID- 10694741
TI - Identification of monoclonal nonspecific suppressor factor beta (mNSFbeta) as one
of the genes differentially expressed at implantation sites compared to
interimplantation sites in the mouse uterus.
AB - Successful implantation requires synchronous development of and active dialogue
between the maternal endometrium and the implanting blastocyst. While it is well
established that appropriate maternal steroid hormones are essential for
endometrial preparation for implantation, the molecular events at the actual site
of implantation are still little understood. The aims of our studies were to
identify genes explicitly expressed or repressed at the sites of implantation by
utilising RNA differential display (DDPCR), and to establish the roles of these
genes in the implantation process in a mouse model. Ten bands unique in
implantation sites compared to interimplantation sites were identified by DDPCR
and subsequently confirmed by Northern blotting. One of these bands contained a
cDNA fragment that was highly homologous to mouse monoclonal nonspecific
suppressor factor beta (MNSFbeta) or Fau. The full cDNA sequence of this gene,
obtained by screening a lambdagt11 cDNA library, was essentially the same as
MNSFbeta, except that it had much longer 5' untranslated region. Interestingly,
both Northern and immunohistochemical analysis showed that the expression of this
gene was much lower in implantation sites compared to interimplantation sites on
day 4.5 of pregnancy, when embryos first attach to the uterus and initiate
implantation, and on day 5.5, when implantation has advanced. These results
suggest a role for MNSF during implantation and early pregnancy, possibly through
regulating the proliferation and/or differentiation of uterine stromal cells. It
may also be involved in the selective production of TH2-type cytokines in
implantation sites to regulate the immune system at the maternal-fetal interface.
PMID- 10694742
TI - Cloning and characterization of a vasa-like gene in rainbow trout and its
expression in the germ cell lineage.
AB - The origin of germ cells and the molecular mechanisms of primordial germ cell
(PGC) determination in teleosts are unclear. Vasa is a member of the DEAD protein
family and plays an indispensable role in germ cell determination in Drosophila
and Xenopus species. In this study, we isolated and characterized a rainbow trout
vasa cDNA as a first step towards understanding the molecular mechanisms of PGC
determination and development and to develop a molecular marker to identify the
PGCs in rainbow trout. Cloning of vasa cDNA was performed by degenerate- and RACE
PCR. The predicted amino acid sequence of rainbow trout Vasa contained eight
consensus sequences for the DEAD protein family and five arginine-glycine-glycine
repeats, a common character of known Vasa homologues. Overall amino acid
similarity to the Vasa of Drosophila was 79.2%. Whole-mount in situ hybridization
of eyed stage embryos (eighty somite stage) revealed that signals were localized
to the putative PGCs. In adult rainbow trout tissues, both ovaries and testes
contained large amounts of vasa gene transcripts. A reverse transcription
polymerase chain reaction analysis of unfertilized eggs proved that trout vasa is
a maternal factor. Although we have not determined whether rainbow trout vasa
functions as a germ cell determinant, its limited expression in the germ cell
lineage proved that rainbow trout vasa can be used as a marker molecule for PGCs.
This marker will make it possible to identify the PGCs or presumptive PGCs in
early trout embryos whose germ cells can not be distinguished by morphological
characteristics.
PMID- 10694743
TI - Murine Myak, a member of a family of yeast YAK1-related genes, is highly
expressed in hormonally modulated epithelia in the reproductive system and in the
embryonic central nervous system.
AB - We have cloned a mouse homologue (designated Myak) of the yeast protein kinase
YAK1. The 1210 aa open reading frame contains a putative protein kinase domain,
nuclear localization sequences and PEST sequences. Myak appears to be a member of
a growing family of YAK1-related genes that include Drosophila and human
Minibrain as well as a recently identified rat gene ANPK that encode a steroid
hormone receptor interacting protein. RNA blot analysis revealed that Myak is
expressed at low levels ubiquitously but at high levels in reproductive tissues,
including testis, epididymis, ovary, uterus, and mammary gland, as well as in
brain and kidney. In situ hybridization analysis on selected tissues revealed
that Myak is particularly abundant in the hormonally modulated epithelia of the
epididymis, mammary gland, and uterus, in round spermatids in the testis, and in
the corpora lutea in the ovary. Myak is also highly expressed in the aqueduct of
the adult brain and in the brain and spinal cord of day 12.5 embryos.
PMID- 10694745
TI - LiCl disrupts axial development in mouse but does not act through the beta
catenin/Lef-1 pathway.
AB - Chimera and cell marking studies suggest that axial determination in mouse
embryos occurs at postimplantation stages. In contrast, Xenopus laevis axes are
determined early due to the asymmetric distribution of maternally derived factors
in the one-cell zygote. In our earlier study we used lithium chloride (LiCl) to
perturb development of mouse axes. Here we investigate whether the lithium
induced axial defects in mouse are being mediated by the beta-catenin/Lef-1
pathway as in Xenopus laevis. In lithium treated embryos we did not observe any
changes in the amount or localization of beta-catenin protein. Furthermore, the
lack of Lef-1 mRNA in treated and untreated embryos indicates the LiCl induced
axial defects in the mouse are not mediated by the beta-catenin/Lef-1 pathway.
PMID- 10694744
TI - Expression of pituitary adenylate cyclase activating polypeptide (PACAP) and
PACAP type I A receptor mRNAs in granulosa cells of preovulatory follicles of the
rat ovary.
AB - Pituitary adenylate cyclase activating polypeptide (PACAP) was isolated from
ovine hypothalamus and known to stimulate the production of cAMP in anterior
pituitary cells. In the recent report, the expression of PACAP was detected in
preovulatory follicles, and treatment with PACAP stimulated the production of
progesterone and prostaglandin E(2) through the action of AC and PLC pathways in
the ovary. PACAP binds to three type receptors. Type I A receptor is coupled to
adenylate cyclase (AC) and phospholipase C (PLC) pathways, while type I B and
type II receptors are only coupled to AC. Thus, the present study aimed to
evaluate the temporal expression of PACAP and its type I A receptor mRNAs in the
rat ovary after treatment with pregnant mare's serum gonadotropin and human
chorionic gonadotropin (hCG). Northern blot analysis showed that PACAP
transcripts were transiently expressed from 3-9 hr after hCG treatment, reaching
a maximum at 6 hr. During these time points, PACAP mRNAs were specifically and
strongly expressed in granulosa cells and cumulus cells of large preovulatory
follicles and interstitial glandular cells. Type I A receptor mRNAs were also
transiently expressed in granulosa cells of large preovulatory follicles from 3-9
hr after hCG treatment. PACAP and its type I A receptor mRNAs were expressed in
the same preovulatory follicles. These results demonstrate that PACAP acts as an
autoregulator or pararegulator through type I A receptor in granulosa cells and
cumulus cells of large preovulatory follicles. Thus, we suggest that PACAP may
have a critical role in granulosa cells of preovulatory follicles for the
preparation of ovulation.
PMID- 10694746
TI - Relationship of gap junction formation to phosphorylation of connexin43 in mouse
preimplantation embryos.
AB - To clarify the relationship of gap junction formation to phosphorylation of
connexin43 (Cx43) in mouse preimplantation embryos, immunofluorescence and
Western blot analysis were conducted. Immunofluorescence showed Cx43 positive
spots first at the mid-eight-cell stage (6 hr postdivision to the eight-cell
stage). The number of spots increased from 6 to 15 hr postdivision to the eight
cell stage. Western blot analysis suggested Cx43 to possibly be present in the
nonphosphorylated form at the mid-four-cell stage (6 hr postdivision to the four
cell stage), and phosphorylated Cx43 to increase from the mid-eight-cell stage (6
hr post-division to the eight-cell stage) onward. Dibutyryl cAMP (dbcAMP), a
protein kinase A (PKA) activator, added to the culture medium increased the
phosphorylation of Cx43 and Cx43 positive spots. The tumor promoter 12-O
tetradecanoylphorbol-13-acetate (TPA), a protein kinase C (PKC) activator,
increased the phosphorylation of Cx43, but decreased Cx43 positive spots. These
results suggest that the phosphorylation of Cx43, induced by different protein
kinase, leads to a different effect on gap junction formation in mouse
preimplantation embryos.
PMID- 10694747
TI - Apoptosis of fetal testicular cells is regulated by both p53-dependent and
independent mechanisms.
AB - A portion of fetal germ cells undergoes apoptosis in the physiological context,
but the molecular mechanisms of their apoptosis are largely unknown. Because p53
tumor suppressor gene product promotes apoptosis in various types of cells, we
have investigated the expression of p53 in fetal gonads and examined the
influence of loss of p53 function in fetal gonad cells using mice deficient in
the p53 gene. We found that the expression of p53 protein in fetal testis was
induced after 15.5 dpc (days post coitum), while the expression was not detected
in fetal ovary. The number of apoptotic cells found in the seminiferous tubules
of fetal testes was not significantly different between p53-deficient and wild
type mice until 16.5 dpc. At 17.5 dpc, however, more apoptotic cells were
observed in wild-type testes than in the p53-deficient mice. In contrast, a
similar number of apoptotic cells was found in fetal ovaries throughout these
developmental stages. These observations indicate that p53 promotes apoptosis of
fetal testicular cells after 16.5 dpc.
PMID- 10694748
TI - Tumor necrosis factor-alpha and its receptor in the corpus luteum of pregnant
cows.
AB - The objective of this study was to investigate the presence of tumor necrosis
factor (TNF)-alpha mRNA and TNF-alpha receptors in the bovine corpus luteum (CL)
during the gestation period. TNF-alpha mRNA and TNF-alpha receptors were
determined on bovine CL from pregnant cows at three stages: trimester I (fetal
crown-rump length; 6-20 cm), trimester II (25-45 cm) and trimester III (50-80
cm). TNF-alpha mRNA was detected by an RT-PCR analysis in the CL of all stages of
gestation. A Scatchard analysis revealed the presence of a high-affinity binding
site (Kd; 5.1-6.9 nM) in the CL membranes collected at each stage of gestation.
Furthermore, the concentrations of TNF-alpha receptors in the CL of trimesters I
(24. 0 +/- 1.95 pmol/mg protein) and III (21.6 +/- 2.39 pmol/mg protein) of
gestation were significantly higher than the concentration in trimester II (14.9
+/- 2.07 pmol/mg protein) (P < 0.05). These results indicate that TNF-alpha is
locally produced and that TNF-alpha receptors are present in bovine CL during the
gestation period, and suggest that TNF-alpha plays one or more roles as a
paracrine factor in regulating bovine CL function during the entire gestation
period.
PMID- 10694749
TI - Nitric oxide is essential for optimal meiotic maturation of murine cumulus-oocyte
complexes in vitro.
AB - This study was conducted to determine whether endothelial-derived nitric oxide
synthase (eNOS) affects meiotic maturation of mouse oocytes in vitro. Cumulus
oocyte complexes (COC) were isolated from ovarian follicles of 27-day-old PMSG
primed wildtype (WT), and eNOS-knockout (eNOS-KO) females, and cultured in drops
of medium under oil at 37 degrees C for 16-18 hr. Experiment 1 was carried out to
determine effects of eNOS deficiency on the ability of COC to mature in vitro. To
determine whether acute synthesis of nitric oxide (NO) was required for oocyte
maturation, COC collected from WT mice were cultured in medium without (control)
or with different doses of N(omega)-nitro-L-arginine methyl ester (L-NAME), an
inhibitor of NOS (exp. 2). To assess effects of NO deficiency on the kinetics of
germinal vesicle breakdown (GVBD), COC from WT and eNOS-KO females were observed
for 3.5 hr. COC from WT females were also incubated in medium without or with L
NAME (exp. 3 and 4). After the culture period, cumulus cells were removed, and
oocytes were counted and classified as metaphase II (M II), metaphase I (M I) or
showing atypical (degenerative) morphology. To determine viability and nuclear
morphology of oocytes, they were stained with fluorescein diacetate or 4,6
diamidine-2'-phenylindole dihydrochloride, respectively. There were no
differences in body weights but ovarian weights were lower in eNOS-KO mice
compared with WT mice (P < 0.05). Ovaries from eNOS-KO mice contained fewer COC
collected relative to WT mice (P < 0.01). Maturation of COC from eNOS-KO mice or
WT oocytes treated with L-NAME resulted in a lower percentage of oocytes at M II
stage (P < 0.01 and P < 0.05, respectively) and a higher percentage of oocytes at
M I or atypical stages compared with those from WT (P < 0.01 and P < 0.05,
respectively). Many oocytes that showed either an arrest in M I stage or abnormal
morphology were not viable. Several oocytes in M II stage demonstrated
abnormalities in distribution of maternal chromosomes. Our data demonstrate that
eNOS-derived NO is a key modulator of oocyte meiotic maturation in vitro. These
results support our previous observations in vivo and indicate that eNOS/NO has
independent functions in both oocyte maturation and follicular/oocyte
development.
PMID- 10694750
TI - Activation of bovine oocytes by specific inhibition of cyclin-dependent kinases.
AB - Activation of bovine oocytes by experimental procedures that closely mimic normal
fertilization and allow to obtain haploid oocytes is essential both for
intracytoplasmic sperm injection (ICSI) and for nuclear transfer. Therefore, with
the goal of producing haploid activated oocytes, this study evaluated whether
bohemine, either alone or in combination with ionomycin, is able to activate
young matured bovine oocytes. Furthermore, the effect of bohemine on the patterns
of DNA synthesis after pronuclear formation as well as changes in histone H1
kinase and MAP kinase activities during the process of activation were studied.
Our results with bohemine show that the specific inhibition of CDKs in metaphase
II bovine oocytes induces parthenogenetic activation in a dose-dependent manner
(25, 50, and 100 microM, respectively), either alone (3%, 30%, and 50%) or in
combination with ionomycin (30%, 70%, and 87.5%). A single pronucleus and
extrusion of the second polar body was observed (97%) when Ca(2+) influx was
stimulated in the presence of bohemine, although pronuclear formation without
polar body extrusion was observed when bohemine was used alone. Bohemine
activated oocytes started to synthesize DNA in the first hour (37%) after their
removal from bohemine-supplemented medium (6-7 hr post-activation; hpa). A high
synchrony in the S-phase was registered with more than 85% of parthenotes
actively synthesizing DNA 8 hpa. By contrast, DNA synthesis was absent in oocytes
cultured for 4, 6, and 8 hpa in the presence of bohemine and a low rate was
observed by those cultured for 18 hr (30%) in bohemine-supplemented medium. This
confirms the ability of the inhibitor to arrest the cell cycle in the G1/S
boundary for at least 8 hr. A drop in histone H1 kinase activity was observed in
bohemine-activated oocytes. The activity of MBP kinase decreased later than
histone H1 kinase and even 4 hr after inomycin-bohemine treatment at least half
of this activity was still detectable. Then, the MBP kinase activity decreased
and the lowest level could be seen 6-8 hpa. In summary, our study shows that in
vitro matured bovine oocytes can be successfully activated by a synthetic
inhibitor of CDKs. This effect can be improved by combination with ionomycin. The
targeting of CDKs in the way to activate bovine oocytes can be an approach to
improve the efficiency of mammalian oocyte activation.
PMID- 10694751
TI - Bovine cumulus/oocyte complex: quantification of LH/hCG receptors.
AB - LH/hCG receptors of the bovine cumulus/oocyte complex were quantified, and their
maximum binding capacities and affinity constants were determined by Scatchard
analysis. Specific binding of these gonadotropins to receptors in follicles of
different sizes was also determined by radiolabeling techniques. A greater number
of receptors was observed to be bound to LH than to hCG (P < 0.05); however,
affinity constants did not significantly differ (P > 0.05). The results of
specific binding of the gonadotropins presented differences in relation to
follicle size. Differences in the specific binding values of LH and hCG were
verified (P < 0.05), but when submitted to linear regression analysis, presented
similar behaviors in relation to follicle size. It is concluded that receptors of
bovine cumulus/oocyte complex cells bind specifically to LH/hCG, that binding
capacity is inversely proportional to follicle size, and that the behavior of hCG
is similar to that of LH, suggesting that hCG can also promote the maturation of
bovine oocytes when used in concentrations greater than LH.
PMID- 10694752
TI - Effects of ethanol and dimethylsulphoxide on nuclear and cytoplasmic maturation
of bovine cumulus-oocyte complexes.
AB - The influence of small doses of ethanol or dimethylsulphoxide (DMSO) on in vitro
maturation (IVM) of bovine cumulus-oocyte complexes (COC) was examined, either
after spontanous maturation or after inhibition of meiosis with 6
dimethylaminopurine (6-DMAP) or 3-isobutyl-1-methylxanthine (IBMX). Subsequent to
IVM for 23 hr in semidefined serum-free Earle's TCM199 medium, nuclear maturation
was assessed cytogenetically, while the combined cytoplasmic and nuclear
maturation was measured indirectly by the oocytes' ability to undergo
fertilization and further embryonic development. Embryo development was followed
until the blastocyst stages at day 9 after insemination. Neither spontanous
nuclear maturation nor cleavage was compromised by IVM in =1% (v/v) ethanol or
=1% (v/v) DMSO, nor was the frequency of polyspermy altered. However, IVM in
0.3% or 1% (v/v) ethanol or in 0.4 or 1% (v/v) DMSO negatively affected
blastocyst formation, compared to 0% in the control groups (22% and 23% vs. 34%,
P < 0.0001, and 29% and 22% vs. 34%, P < 0.01, respectively), whereas the speed
of blastocyst formation, assessed as the D7/D9 blastocyst proportion, was not
compromised. In oocytes meiotically inhibited with 2 mM 6-DMAP, the presence of
ethanol (0. 5%, 1%, and 2% [v/v]) induced germinal vesicle breakdown in a dose
dependent manner (32%, 45%, and 68%, vs. 22%, P < 0.0001), however, the oocytes
exhibited no further meiotic progression. In oocytes inhibited with 1 and 2 mM
IBMX, the presence of ethanol (0. 5%, 1%, and 2% [v/v]) significantly (P < 0.05)
enhanced the inhibitory effect in a dose-dependent manner by reducing the
proportion of the mature (AI-MII) stages (77%, 68%, and 56% vs. 79%, and 33%,
29%, and 18% vs. 39%, respectively). It is concluded that even small doses of
ethanol or DMSO can cause profound negative effects on bovine in vitro maturation
and subsequent embryo development.
PMID- 10694753
TI - Identification of homologous binding proteins in porcine and bovine gametes.
AB - The purpose of this study was to determine if sperm and oocyte proteins that
mediate plasma membrane interaction during mammalian fertilization are conserved
among porcine and bovine gametes. We examined homologous and heterologous sperm
and zona-free oocyte interactions to determine the extent of cross-reactivity
between the gametes of these two ungulate species. First, the numbers of
ejaculated porcine and bovine sperm bound to the oocyte plasma membrane of intact
porcine and bovine oocytes were determined in vitro. There was no significant
difference between the number of porcine or bovine sperm that bound to porcine or
bovine oocytes (P > 0.25). Second, individual porcine and bovine sperm plasma
membrane proteins were identified by binding of homologous or heterologous oocyte
plasma membrane to whole sperm plasma membrane on Western ligand blots. The
relative amount of labeled oocyte plasma membrane bound to individual sperm
plasma membrane proteins was analyzed by laser densitometry. Eight porcine sperm
plasma membrane proteins and seven bovine sperm plasma membrane proteins were
bound by both porcine and bovine oocyte plasma membrane. A significantly greater
relative amount of porcine oocyte plasma membrane than bovine oocyte plasma
membrane was bound to the 14- and 10-kD porcine sperm plasma membrane proteins (P
< 0.001 and P < 0.01, respectively). A 27-kD bovine sperm plasma membrane protein
bound proportionally more bovine oocyte plasma membrane probe than porcine oocyte
plasma membrane probe (P < 0.04). These results are consistent with conservation
of similar receptor ligand interactions at the gamete plasma membrane among
porcine and bovine gametes.
PMID- 10694754
TI - Oct-4: control of totipotency and germline determination.
AB - The transcription factor Oct-4 is expressed in totipotent embryonic cells and
germ cells. As totipotent cells differentiate to form somatic and/or
extraembryonic tissues, the Oct-4 gene is downregulated. Primordial germ cells
are the only cells in which Oct-4 expression is maintained after
postgastrulation. Recent in vivo ablation of the Oct-4 function has shown that
the absence of this transcription factor causes early embryonic lethality due to
trophectodermal differentiation of cells which normally would give rise to the
inner cell mass of the blastocyst. This result strongly suggests that Oct-4 is
necessary for the maintenance of the totipotent phenotype of embryonic cells and
that this factor likely plays a role as a determinant of the totipotency of germ
cells by preventing their differentiation to a somatic cell phenotype during
gastrulation. The involvement of Oct-4 in the biology of totipotent and germ
cells is here discussed in view of new understanding about Oct-4 function.
PMID- 10694755
TI - Managed care in the United States: a dilemma for evidence-based policy?
PMID- 10694756
TI - The relationship between marijuana initiation and dropping out of high school.
AB - The prevalence of marijuana use among young people has risen rapidly in recent
years, causing concern over the potential impact on academic performance of such
use. While recent studies have examined the effect of alcohol use on educational
attainment, they have largely ignored the potential negative effects of other
substances, such as marijuana. This paper examines whether the relationship
between the initiation of marijuana use and the decision to drop out of high
school varies with the age of dropout or with multiple substance use. Data are
from a longitudinal survey of 1392 adolescents aged 16-18 years. The results
suggest that marijuana initiation is positively related to dropping out of high
school. Although the magnitude and significance of this relationship varies with
age of dropout and with other substances used, it is concluded that the effect of
marijuana initiation on the probability of subsequent high school dropout is
relatively stable, with marijuana users' odds of dropping out being about 2.3
times that of non-users. Implications of these conclusions are considered for
both policy makers and researchers.
PMID- 10694757
TI - Policy analysis of the use of hepatitis B, Haemophilus influenzae type b-,
Streptococcus pneumoniae-conjugate and rotavirus vaccines in national
immunization schedules.
AB - After the development of national vaccine programmes to deliver six vaccines to
infants, new vaccine adoption has been limited. Analysis of the health and
economic implications of new vaccination options can help national policy-makers.
Country specific quantitative policy analyses were conducted to estimate the
impact of vaccination against hepatitis B (HB), Haemophilus influenzae type b
(Hib), Streptococcus pneumoniae (SP) and rotavirus. Disease burden, programme
costs and the potential reduction of disease from vaccination was assessed for
each vaccine. Without vaccination, these four vaccine preventable diseases
contribute up to 4.1 million deaths in each successive birth cohort. Routine
scheduled use of HB and Hib vaccines could prevent up to 1.7 million deaths; SP
and rotavirus vaccines, an additional 1.4 million deaths, annually. The global
cost per life-year saved ranged from $29 to $150 with great variation by income
and economic groups. With a few exceptions for a few countries, these vaccines
would cost a fraction of average per-capita gross domestic product to save a life
year. The addition of HB and Hib vaccines, should be considered for integration
in all national immunization programmes. SP and rotavirus vaccines, with the
given assumptions, would also be cost-effective. Proactive analysis of the
economic and epidemiologic impact of these vaccines can hasten their introduction
into national vaccination schedules.
PMID- 10694758
TI - Measuring productivity loss days in asthma patients. The Pharmacy Medication
Monitoring Program and Advisory Board.
AB - In assessments of the cost of illness, productivity losses potentially constitute
a large proportion. The present study objective was to develop a method to
measure restricted days and to quantify total productivity loss days (PLDs) in
adult asthma patients. Patient and disease characteristics, occupation, annual
wage, work absences, restricted days, level of functioning on restricted days,
and travel and waiting time were collected over 6 months in 892 adult asthma
outpatients residing in southern Ontario. Annual PLDs varied from 12 in employed
persons to 49 in disability pensioners. Homemakers reported 22 PLDs per year.
Restricted days accounted for most PLDs and functional level during restricted
days varied from 55% to 81%. Annual PLDs increased with increasing disease
severity. Employed persons experienced the fewest PLDs and functioned at the
highest level during restricted days, but also demonstrated a milder disease
compared with other groups. Most productivity loss in asthma patients resulted
from numerous restricted days, a category of PLD that is often ignored in
economic assessments. The presentation of PLD results disaggregated by category
of time loss and wage rate may provide valuable information to employers and
health policy makers and may facilitate the application of multiple approaches to
the calculation of indirect costs.
PMID- 10694759
TI - Are preferences over health states complete?
AB - Most applied work in health economics accepts, if only implicitly, the axiom of
completeness. Preferences over health states or health services are assumed to be
well formed. They are effectively 'data' waiting to be collected. An alternative
perspective suggests that values are initially incomplete and are constructed
rather than just revealed in the process of answering choice-related questions
such as willingness to pay or standard gambles. What might appear as measurement
error may, therefore, be a more deliberate process of reflection and
deliberation. This paper reports on a study that assessed the completeness of
health preferences. The results show a mixed pattern. For most of the sample,
values were stable over repeat administration, suggesting completeness. However,
one-third of participants deliberately changed their answers and suggested that
the interview process had forced them to think about their values more deeply.
While it is premature to draw conclusions from this small sample, the suggestion
is that completeness cannot be taken for granted.
PMID- 10694760
TI - QALYs and ageism: philosophical theories and age weighting.
AB - QALY maximization is sometimes criticized for being 'ageist', because, other
things being equal, the elderly, with a shorter life expectancy, will be given
lower priority. On the other hand, there are philosophical arguments that, for
different reasons, advocate rationing health care to the elderly, even when the
size of the expected benefits in QALY terms is the same across older and younger
patients. This paper examines six proposals, both from the philosophical and the
health economics literature, that will lead to such conclusions. These are: two
variants of the so-called fair innings argument, the fair innings weights, the
Disability Adjusted Life Year (DALY) age weighting, the biographical life span,
and the prudential lifetime account. Two questions are addressed with regard to
each of these. First, what is the reason for choosing the younger patient when
the QALY gains are equal; second, will the younger patient continue to be chosen
even when the QALY gains to the older patient are larger. The paper studies the
relationship between the six proposals and explores their possible implications
for QALY maximization.
PMID- 10694761
TI - Progress and directions in refining the global burden of disease approach: a
response to Williams.
PMID- 10694762
TI - Comments on the response by Murray and Lopez.
PMID- 10694764
TI - Anaemia in pregnancy: possible causes and risk factors in Nepali women.
AB - OBJECTIVE: The aim of this study was to investigate the importance of nutritional
deficiencies and infections in the development of anaemia in pregnant Nepali
women. DESIGN: Case-control study. SETTING: Patan Hospital, Kathmandu, Nepal.
SUBJECTS: A sub-sample (n=479) of all pregnant women (n=2856) coming for their
first antenatal visit in a 12 month period, 1994-1995. Women who had already
received any micronutrient supplementation (n=82), and those whose serum samples
showed macroscopic haemolysis (n=7) were excluded. The remaining women (n=390)
were included in the statistical analysis. They were divided into three groups; a
non-anaemic control group, haematocrit (Hct)>33% (n=82), and two case-groups:
moderately anaemic, Hct 25-33% (n=254), and severely anaemic, Hct<25% (n=54).
RESULTS: We found high prevalences of nutritional deficiencies and intestinal
infections, both among cases and controls. The prevalence of low s-ferritin was
high, especially among the severely anaemic women (55.6%). In a multiple logistic
regression model, the presence of low s-vitamin A, elevated s-C-reactive protein
or hookworm infection was associated with a significantly increased risk of
severe anaemia. The adjusted odds ratios (95% CI) were 8.38 (1.99, 35.30), 4.91
(1.22, 19.67) and 5.43 (1.20, 24.61), respectively. CONCLUSIONS: In addition to
the present routine iron and folate supplementation to pregnant Nepali women,
vitamin A supplementation needs to be considered. Prevention and treatment of
infections should, together with dietary advice, be emphasized more strongly in
the antenatal care. SPONSORSHIP: The Norwegian Research Council and the Norwegian
Universities Committee for Development, Research and Education. European Journal
of Clinical Nutrition (2000) 54, 3-8
PMID- 10694765
TI - Relation of lifestyle factors to metacarpal bone mineral density was different
depending on menstrual condition and years since menopause in Japanese women.
AB - OBJECTIVE: To examine whether the relation between lifestyle and metacarpal bone
mineral density (BMD) varied with life-stages. DESIGN: Cross-sectional study.
SETTING: Taking questionnaires related to lifestyle and examining metacarpal BMD
by computed X-ray densitometry at a local health care center. SUBJECTS: Out of
750 Japanese women aged 40-69 y old who underwent screening for osteoporosis, we
selected 535 healthy subjects without medical conditions or lifestyle factors
known to affect bone metabolism. RESULTS: A cross-sectional comparison of BMD and
years since menopause (YSM) resulted in a logarithmic regression model (BMD=2.
539-0.149xloge YSM, r2=0.418), indicating that a prominent reduction in
metacarpal BMD appears up to 4-6 y after menopause. In premenopausal women with
regular menstruation, those who engaged in regular physical activity during
adolescence showed significantly greater BMD than those who did not. In 1-5-y
postmenopausal women, those with current calcium intake of more than 800 mg/d,
current milk intake greater than 900 ml/week, daily consumption of milk and/or
dairy products, or frequent consumption of small fish showed significantly
greater BMD. In 6-15-y postmenopausal women, those who took more than 6000 or
8000 steps/day showed significantly greater BMD. CONCLUSIONS: The relation
between lifestyle and BMD differed with life-stages in Japanese women. It was
suggested that to perform lifestyle modifications for the prevention of
osteoporosis, life-stages should be taken into consideration. SPONSORSHIP: Grant
for Research on Health Service from Ministry of Health and Welfare, Japan and
grant from The National Dairy Promotion and Research Association of Japan.
European Journal of Clinical Nutrition (2000) 54, 9-13
PMID- 10694766
TI - Effects of soy as tofu vs meat on lipoprotein concentrations.
AB - OBJECTIVES: To investigate the effect of replacing lean meat with a soy product,
tofu, on serum lipoprotein concentrations. STUDY AND DESIGN: Randomized cross
over dietary intervention study. SUBJECTS: Forty-two free-living healthy males
aged 35-62 y completed the dietary intervention. Three additional subjects were
non-compliant and excluded prior to analysis. INTERVENTIONS: A diet containing
lean meat (150 g/d) was compared with one with 290 g/d tofu in an isocaloric and
isoprotein substitution. Both diet periods were 1 month, and fat intake was
carefully controlled. RESULTS: Seven-day diet records showed the two diets were
similar in energy, macronutrients and fibre. Total cholesterol (mean difference
0.23 mmol/l, 95% CI 0.02, 0.43; P=0.03) and triglycerides (mean difference 0.15
mmol/l, 95% CI 0.02, 0.31; P=0.017) were significantly lower on the tofu diet
than the lean meat diet. However, HDL-C was also significantly lower on the tofu
diet (mean difference 0.08 mmol/l, 95% CI 0.02, 0.14; P=0.01) although the LDL
C:HDL-C ratio was similar. CONCLUSION: The effect on HDL-C and the small LDL-C
reduction differ from some other studies, where fat was often less controlled,
and the comparison was of soy as textured protein or soymilk against casein. This
suggests a differential effect of the various proteins compared to the soy may
influence the findings. In practice, the replacement of meat with tofu would
usually be associated with a decrease in saturated fat and an increase in
polyunsaturated fat and this should enhance any small benefits due to the soy
protein. SPONSOR: Deakin University with some contribution from a Commonwealth
Department of Veterans Affairs research grant. European Journal of Clinical
Nutrition (2000) 54, 14-19
PMID- 10694767
TI - Near infrared spectroscopy-a potentially useful method for rapid determination of
fat and protein content in homogenized diets.
AB - OBJECTIVE: To investigate the potential of near-infrared reflectance (NIR)
spectroscopy as a rapid and non-destructive method to determine total fat and
protein in mixed, homogenized and freeze-dried human diets. DESIGN: 29 students
collected duplicate portions of their diet for four consecutive days. In
addition, a detailed food diary was kept. The duplicate portions were analysed
for total protein and fat content both by traditional chemical analysis (Kjeldahl
and Folch methods) and through the recently developed NIR spectroscopy method. In
addition, traditional computerized estimation of nutrient composition was
performed. RESULTS: Plotting of the NIR-predicted fat content against the
chemically analysed fat content gave a correlation coefficient of 0. 99. Plotting
of the NIR-predicted protein content against the Kjeldahl-analysed protein gave a
correlation coefficient of 0.81. CONCLUSION: NIR-spectroscopy seems to be able to
determine fat content in mixed, homogenized diets to a high degree of accuracy.
In surveys involving duplicate portion sampling this will save time and money.
The prediction accuracy for protein was less convincing, but acceptable depending
on the need for accurate individual data. SPONSORSHIP: Norwegian Food Research
Institute, Institute for Nutrition Research at the University of Oslo and the
Research Society of the Norwegian Edible Fat Producers and the food company Mills
DA. European Journal of Clinical Nutrition (2000) 54, 20-23
PMID- 10694768
TI - Effects of a low-glycaemic index spaghetti meal on glucose tolerance and lipaemia
at a subsequent meal in healthy subjects.
AB - OBJECTIVE: The aim of the study was to evaluate the impact of a low glycaemic
index (GI) breakfast on glucose tolerance and lipaemia at a subsequent lunch
meal. DESIGN: A low GI spaghetti meal and a high-GI white wheat bread (WWB)
reference meal were served in the morning after an overnight fast in random
order. Four hours after the breakfast, the subjects were given a second meal-a
standardized high-GI lunch-and the blood glucose, insulin and lipid responses
were measured after the lunch meal. SETTING: The study was performed at the
Department of Applied Nutrition and Food Chemistry, Lund University, Sweden.
SUBJECTS: Ten healthy volunteers, eight women and two men, aged 25-51 y, with
normal body mass indices, were recruited. RESULTS: Lowered glucose and insulin
responses and reduced serum triglyceride (TG) level were found at the subsequent
lunch meal when the low-GI spaghetti meal was given as a breakfast. No
differences in total serum cholesterol or HDL cholesterol were seen after lunch,
when preceded by the WWB reference breakfast or the spaghetti breakfast,
respectively. CONCLUSIONS: Improved glucose tolerance and lowered serum TG levels
can appear in the course of a single day. As insulin resistance and raised
postprandial TG concentration are known risk factors for cardiovascular disease,
the present study adds evidence for a beneficial role of a low-GI diet.
SPONSORSHIP: Cerealia Foundation for Research and Development (project no. 232)
and the Swedish Council for Forestry and Agricultural Research. European Journal
of Clinical Nutrition (2000) 54, 24-28
PMID- 10694769
TI - Effect of daily iron supplementation on iron status, cell-mediated immunity, and
incidence of infections in 6-36 month old Togolese children.
AB - OBJECTIVE: To assess the impact of a daily oral iron supplementation on
hematological status, cell-mediated immunity and susceptibility to infections in
children living in an environment where iron deficiency, malaria and other
infections are frequent. DESIGN: Randomized, double-blind iron supplementation
including a placebo group. SETTING: A village in Togo, West Africa. SUBJECTS: Of
the 229 6-36-month-old children of both sexes recruited, 197 with hemoglobin
concentration >/=80 g/l were included and 163 completed the study. INTERVENTION:
Children received daily a placebo (n=79) or a dose of 2-3 mg of elemental iron
per kg of body weight (n=84) for 3 months. Hematological, nutritional and immune
status were assessed at the beginning and at the end of the supplementation
period, and 6 months later. Morbidity was recorded throughout the study. RESULTS:
Iron supplementation had a significant and positive effect on iron status of
children and no impact on the incidence of infections, especially malaria. Its
probable effect on immune status was masked by interference of infections and
their treatment, which contributed to improve hematological and immune status in
both groups. CONCLUSION: According to the negative consequences of anemia and
iron deficiency on global child development, control of iron deficiency by oral
iron supplementation in young children has to be conducted, associated with
prophylaxis and treatment of malaria and repeated deworming. SPONSORSHIP: Program
supported by IRD. European Journal of Clinical Nutrition (2000) 54, 29-35
PMID- 10694770
TI - Age patterns in stunting and anaemia in African schoolchildren: a cross-sectional
study in Tanzania.
AB - OBJECTIVE: To describe the nutritional status of schoolchildren from a rural area
of Tanzania, with a particular emphasis on older adolescents to determine the
timing of the growth spurt and differences by sex. DESIGN: A cross-sectional
survey using a randomly selected sample. SUBJECTS: Six thousand eight hundred and
one children aged 7-18 y randomly selected from those enrolled in standards 2-5
in 59 primary schools in Magu District, Tanzania. RESULTS: Overall, 52.5% of
children were stunted and 43.0% were underweight, with significantly more boys
stunted and underweight than girls. Z-scores of height-for-age for both boys and
girls decreased progressively between 7 and 12 y. After 12 y the height-for-age z
scores of girls show a marked upturn, whilst z-scores for boys continue to
decrease throughout the school-aged years until 16 y when a slight upturn is
observed. Anaemia (Hb<120 g/L) was present in 62.6% of children, with the
prevalence decreasing with age. Anaemia improved throughout the school years for
boys, but did not for girls. Age, sex and hookworm infection were significant
predictors of anaemia. CONCLUSION: Stunting and anaemia are exceptionally common
conditions in African schoolchildren. The findings highlight important
differences between boys and girls, which are suggestive of compensatory growth
at 12 y for girls and at 16 y for boys, although it remains unclear whether boys
will catch up in height at older ages. SPONSORSHIP: Funding was provided by the
Wellcome Trust. European Journal of Clinical Nutrition (2000) 54, 36-40
PMID- 10694771
TI - Predictors of growth from 1 to 18 months among breast-fed Ghanaian infants.
AB - OBJECTIVE: To examine factors associated with the physical growth of breast-fed
Ghanaian infants during the first 18 months of life. DESIGN: A community-based
longitudinal study. SETTING: The study was carried out in Techiman, a district
capital and major food trading center in the Brong Ahafo region of Ghana.
SUBJECTS: One-month old infants (n=216) with birth weight >/= 2.5 kg were
recruited from Maternal and Child Health Centers. METHOD: From 6 to 12 months,
infants were provided with one of four types of nutritionally enhanced
complementary foods. Anthropometric assessments were completed monthly from 1 to
12 months and every other month from 12 to 18 months. Information was collected
on household characteristics, morbidity from common infections and dietary
intakes. Blood samples were collected at 6 and 12 months to assess iron, zinc,
riboflavin and vitamin A status. Multiple regression analysis was used to examine
factors associated with growth during the age intervals of 1-6, 4-6, 6-12 and 12
18 months as well as size attained at 12 and 18 months. RESULTS: Prevalence of
diarrhea and fever were negatively associated with growth during the first year
of life. No significant relationship was found between respiratory illness
(defined as cough or purulent nasal discharge) and growth. With the exception of
dietary zinc intake, dietary variables were generally not significantly
associated with growth. Maternal education was positively associated with growth
during most of the age intervals. CONCLUSION: These findings suggest that
interventions to reduce morbidity and improve the education of girls may benefit
children's growth in this population. SPONSORSHIP: Nestle Foundation; Rockefeller
Foundation African Dissertation Internship Award; Fulbright Scholarship. European
Journal of Clinical Nutrition (2000) 54, 41-49
PMID- 10694772
TI - Arachidonic and docosahexaenoic acids are strongly associated in maternal and
neonatal blood.
AB - BACKGROUND: The red cell membrane fatty acid composition has frequently been used
as an index of essential fatty acid (EFA) nutrition. After birth there is a
decline in plasma arachidonic acid (AA) and docosahexaenoic (DHA) acids in babies
fed on conventional formula which contains only the parent linoleic and alpha
linolenic acids. In human studies, the red cell phosphoglyceride composition
appears to be more constant than that of plasma. In infants fed fish oil without
AA, the AA proportions fall in the plasma but much less so in the red cells. This
result might be considered to mean that there is no need for preformed AA. On the
other hand, in a study where the levels of AA fell there was reduction of infant
growth. Indeed, where cell membrane composition does change there is often an
associated alteration in physiological functions of membranes. We therefore felt
it worth investigating the balance between AA and DHA in a physiological
situation where plasma levels are known to change, namely in pregnancy. PURPOSE:
The aim of the study was to investigate a relationship between blood
phosphoglyceride AA and DHA in pregnant women and neonates. SUBJECTS: Health
pregnant women from London, England (n=193) and their term babies (n=45); healthy
pregnant women from Seoul, South Korea (n=40) and their term babies (n=40); and
preterm neonates (n=72) from London. METHOD: Blood samples were taken from
British and Korean pregnant women during the third trimester, and from term and
preterm babies at birth. These samples were taken for routine monitoring purposes
in Korea and were a part of a study on pregnancy outcome for which ethical
permission was granted from the East London and The City Health Authority and
Lambeth, Southwark and Lewisham Health Authority. Approval was also obtained from
the Ethical Committee of the Asan Medical Centre, Seoul, South Korea. RESULTS: AA
and DHA correlated in plasma choline phosphoglycerides (CPG) of the British
mothers (r=0.52 P<0.0001). The correlation coefficients and significance were
much stronger in the red cell CPG and even more so in the term and preterm infant
red cell CPGs ( r=0.75, 0.80 and 0.88, respectively). Similarly, AA and DHA
correlated in red cell CPGs of the Korean women and their term babies. There was
also a significant relationship between the two fatty acids in red cell
ethanolamine phosphoglycerides in the mothers and their babies. Both linoleic
(LA) and alpha-linolenic acids (ALA) were inversely associated with AA and DHA in
some of the phosphoglyceride fractions of the mothers and babies. CONCLUSIONS:
Although AA and DHA have different primary dietary origins, there were
significant relationships between AA and DHA in the phosphoglycerides of the red
cell membrane. This finding seems surprising if the red cell composition is
determined by diet. These results suggest a physiological mechanism which
attempts to maintain an appropriate balance between AA and DHA. It is plausible
that there is an optimum balance between AA and DHA for membrane stability,
deformability, enzyme and receptor function. SPONSORSHIP: The British Diabetic
Association, March of Dimes Birth Defects Foundation and The Christopher H.R.
Reeves Charitable Trust. European Journal of Clinical Nutrition (2000) 54, 50-56
PMID- 10694773
TI - Iodine content in drinking water and other beverages in Denmark.
AB - OBJECTIVE: To investigate the variation in iodine content in drinking water in
Denmark and to determine the difference in iodine content between organic and non
organic milk. Further, to analyse the iodine content in other beverages. DESIGN
AND SETTING: Tap water samples were collected from 41 evenly distributed
localities in Denmark. Organic and non-organic milk was collected at the same
time (twice summer and twice winter). Soft drinks, beers and juice were collected
from different Danish producers and wine from different countries. All samples
were analysed for iodine using inductively coupled mass spectrometry. RESULTS:
Iodine in tap water varied from 2.1 to 30.2 microg/l; the iodine content was in
general highest in the eastern part of Denmark and lowest in the western part of
Denmark. Organic milk was found to have a lower iodine content than non-organic
milk. CONCLUSIONS: Large geographical (and seasonal) variations in iodine
concentrations were found in different beverages supplying an appreciable part of
the iodine in the Danish diet. This knowledge is important when calculating the
iodine intake from dietary intake studies. SPONSORSHIP: The 1991 Farmacy
Foundation and Danish Veterinary and Food Administration. European Journal of
Clinical Nutrition (2000) 54, 57-60
PMID- 10694774
TI - Comparison of an oleic acid enriched-diet vs NCEP-I diet on LDL susceptibility to
oxidative modifications.
AB - OBJECTIVE: The objective of this trial was to compare the effect on the
susceptibility of plasma Low Density Lipoprotein (LDL) to oxidative modifications
of consumption of two oleic rich diets, prepared with two different plant oils,
virgin olive oil (OL)1 and refined high monounsaturated fatty acids (MUFA
sunflower oil (SU)), with the susceptibility of plasma LDL to oxidation after an
National Cholesterol Education Program step 1 (NCEP-I) phase diet. DESIGN: A
randomized crossover design. SUBJECTS AND INTERVENTIONS: Twenty-two healthy
normolipidemic young males consumed an NCEP-I diet for a 4-week period. Subjects
were then assigned to two diets each of 4-weeks duration. Group one was placed on
an olive oil enriched diet (40% fat, 22% MUFA) followed by a 4-week period of a
MUFA diet enriched in sunflower oil (40% fat, 22% MUFA). In group two, the order
of the diets was reversed. RESULTS: Both MUFA diets induced a decrease in
saturated (14:0, 16:0, and 18:0) and an increase in monounsaturated and
polyunsaturated n-6 (18:2, 20:3, and 20:5) plasma LDL-phospholipid fatty acids,
compared to the NCEP-I diet (P<0.01). No significant differences in lag times
were observed between the olive oil and the NCEP-I diet periods. However there
was a greater inhibition time (P<0.001) when subjects consumed the MUFA rich
sunflower oil diet compared to the NCEP-I diet. These differences were probably
related to the relative enrichment of plasma LDL particles in alpha-tocopherol
due to the high vitamin E content of the MUFA-rich sunflower oil. Indeed, the
alpha-tocopherol content was positively correlated with lag time (r=0.338;
P<0.008). CONCLUSION: Our findings suggest that changes in plasma LDL alpha
tocopherol content with practical solid-food diets can decrease its
susceptibility to oxidation. SPONSORSHIP: This work has been supported by grants
from the Investigaciones de la Seguridad Social (FIS 92/0182, to Francisco Perez
Jimenez); and from Koype Co, Andujar, Jaen, Spain. European Journal of Clinical
Nutrition (2000) 54, 61-67
PMID- 10694775
TI - Vitamin D status and parathyroid hormone concentrations in Chinese women and men
from north-east of the People's Republic of China.
AB - STUDY OBJECTIVE: To evaluate vitamin D status of young and old women and men
living in Shenyang, north-east People's Republic of China in early spring and to
explore the relationship between vitamin D metabolites and parathyroid hormone
(PTH) in this population. DESIGN: Cross-sectional study. SETTING: Shenyang, north
east China. SUBJECTS: 194 healthy volunteers: 48 young women and 48 young men
aged 25-35 y, and 48 old women and 50 old men aged 65-75 y. RESULTS: Fasting
blood samples were used to measure plasma 25-hydroxyvitamin D (25(OH)D), 1,25
dihydroxyvitamin D (1,25(OH)2D) and PTH using radioimmunoassays. The proportion
of subjects who could be regarded as vitamin D deficient (<25 nmol/l) was 48%,
29%, 15% and 13% for old men, young men, old women and young women, respectively.
There was no association between plasma 1,25(OH)2D and 25(OH)D concentrations.
PTH concentrations were elevated in both old women and men compared with young
subjects (P<0.01). A negative association between PTH and 25(OH)D was only found
in old women (P<0. 001), but not in old men, nor in young subjects. CONCLUSIONS:
Vitamin D status was poor in this population in early spring, especially in men.
There was no clear evidence to show that the secretion of PTH and the conversion
of 1,25(OH)2D were affected by the low 25(OH)D concentration. SPONSORSHIP: Partly
supported by the Sandoz Foundation for Gerontological Research and the Nestle
Foundation, Switzerland, and Medical Research Council, UK. European Journal of
Clinical Nutrition (2000) 54, 68-72
PMID- 10694776
TI - Ten-year trends in vitamin and mineral intake from fortified food in German
children and adolescents.
AB - OBJECTIVE: We investigated time trends in consumption patterns, and energy and
nutrient intakes (protein, fat, carbohydrates, added sugars, vitamins A, E, C,
B1, B2 and B6, niacin, folate, calcium and iron) from fortified food in children
and adolescents between 1987 and 1996 in Germany. DESIGN: Mixed longitudinal
survey (DONALD study) with 3 d weighed dietary records (n=2062 from 594
subjects), one subject per family per year chosen by random. SETTING: Dortmund
(Western Germany) district cohort. SUBJECTS: 285 males, 309 females; mean age 6 y
(2-13 y). RESULTS: Almost all children and adolescents consumed fortified food
irrespective of the year studied. With the exception of vitamin E, significant
time trends in the proportions of nutrient intakes from fortification were
observed. The fortification of food with vitamins A, C, B1, B2 and B6 and niacin
raised the already adequate intakes from non-fortified food (100% to 150% of
reference intake values) by 20-50%. The fortification of food with vitamin E and
folate raised the low intakes from non-fortified food (about 50% of reference
intake values) to about 80% (folate) and 100% (vitamin E) of the references.
Fortification of food with calcium and iron was not significant (<10%), but while
total intake of calcium was adequate, total intake of iron remained critical.
CONCLUSIONS: Since the nutrient intake of the population of children and
adolescents studied is adequate with respect to vitamins A, C, B1, B2 and B6,
niacin and calcium, fortification seems inefficient, while fortification of food
with vitamin E and folate, but not iron, improves an inadequate intake.
SPONSORSHIP: The DONALD study is supported by the German Federal Ministry of
Health and the North-Rhine-Westphalian Ministry of Science and Research. European
Journal of Clinical Nutrition (2000) 54, 81-86
PMID- 10694777
TI - A single dose of tea with or without milk increases plasma antioxidant activity
in humans.
AB - OBJECTIVE: To investigate the effect of black and green tea consumption, with and
without milk, on the plasma antioxidant activity in humans. DESIGN: In a complete
cross-over design, 21 healthy volunteers (10 male, 11 female) received a single
dose of black tea, green tea (2 g tea solids in 300 ml water) or water with or
without milk. Blood samples were obtained at baseline and at several time points
up to 2 h post-tea drinking. Plasma was analysed for total catechins and
antioxidant activity, using the ferric reducing ability of plasma (FRAP) assay.
RESULTS: Consumption of black tea resulted in a significant increase in plasma
antioxidant activity reaching maximal levels at about 60 min. A larger increase
was observed after consumption of green tea. As anticipated from the higher
catechin concentration in green tea, the rise in plasma total catechins was
significantly higher after consumption of green tea when compared to black tea.
Addition of milk to black or green tea did not affect the observed increases in
plasma antioxidant activity. CONCLUSIONS: Consumption of a single dose of black
or green tea induces a significant rise in plasma antioxidant activity in vivo.
Addition of milk to tea does not abolish this increase. Whether the observed
increases in plasma antioxidant activity after a single dose of tea prevent in
vivo oxidative damage remains to be established. European Journal of Clinical
Nutrition (2000) 54, 87-92
PMID- 10694778
TI - Dietary habits among patients with atopic dermatitis.
AB - OBJECTIVE: To evaluate the dietary habits among adult patients with moderate to
severe atopic dermatitis and relate intake to clinical symptoms. DESIGN: Data
were obtained from a clinical trial. SETTING: Five departments of dermatology at
Norwegian University hospitals. SUBJECTS: Outpatients, 46 men (median age 27 y)
and 92 women (median age 28 y). METHOD: A quantitative food frequency
questionnaire was filled in before attending the clinical trial. The results were
compared to the diet of age- and sex-matched reference groups. RESULTS: Male
patients had higher content of refined sugar in their diet than reference men
(P=0.014). Among female patients, the intake of saturated fatty acids was higher
(P=0.049), whereas the intake of very long-chain n-3 fatty acids was lower
(eicosapentaenoic acid, P=0.032, docosahexaenoic acid, P=0.017) than in the
reference group. In both genders, more patients than reference subjects had
vitamin D intake below recommended level. Furthermore, the female patients had
significantly lower intake of fruit compared to the reference group (P=0.002). No
correlation was found between nutrient intake of the patients and their clinical
scores. CONCLUSIONS: The patients's diet were fairly similar to the diet of
reference groups. The intake of vitamin D and very long-chain n-3 fatty acids was
low, especially among female patients. Furthermore, we could not detect any
association between dietary habits and clinical status. European Journal of
Clinical Nutrition (2000) 54, 93-97
PMID- 10694779
TI - Toenail selenium and breast cancer-a case-control study in Finland.
AB - OBJECTIVE: Low levels of selenium have been associated with a higher risk of
cardiovascular diseases and cancer in humans. Since 1984, selenium
supplementation through fertilizers has been employed in Finland to increase the
very low concentration of selenium in the nation's food supply. As a result, the
selenium concentration of Finnish foods became one of the highest in Europe. A
decade after selenium supplementation began, the association between toenail
selenium and the risk of breast cancer was examined. DESIGN: Case-control study.
SETTING: Eastern Finland. SUBJECTS: 289 pre- and postmenopausal breast cancer
cases and 433 community controls. The diagnosis was unknown at the time the
toenail samples were collected. RESULTS: The mean toenail selenium concentration
was 0.80 mg/kg in premenopausal cases and 0.84 mg/kg in premenopausal controls:
and 0. 77 mg/kg in postmenopausal cases and 0.80 mg/kg in postmenopausal
controls. The odds ratio (OR) comparing the highest with the lowest quintiles of
toenail selenium concentration was 1.1 (95% CI 0.4-3.2) in premenopausal women
and 0.7 (95% CI 0.3-1.5) in postmenopausal women. The intake of retinol, beta
carotene, vitamin E and vitamin C did not change the association between toenail
selenium and breast cancer. CONCLUSIONS: A decade after selenium supplementation,
selenium seems not to be an important factor in the etiology of breast cancer,
neither in premenopausal nor postmenopausal women. SPONSORSHIP: This work was
supported by the EVO funds from the Kuopio University Hospital and by research
grants from the Academy of Finland, Yrjo Jahnsson Foundation and Juho Vainio
Foundation. European Journal of Clinical Nutrition (2000) 54, 98-103
PMID- 10694780
TI - The effect of dietary trans alpha-linolenic acid on plasma lipids and platelet
fatty acid composition: the TransLinE study.
AB - OBJECTIVE: To collect (i) baseline data and (ii) execute a large multicentre
study examining the effect of trans alpha-linolenic acid on its incorporation
into plasma lipids and on risk factors for coronary heart disease. DESIGN: Male
volunteers were recruited and the habitual diet assessed by a 4-d weighed record.
Fatty acid composition of plasma and platelet lipids were determined by gas
chromatography at baseline. After a 6 week run-in period on a trans 'free' diet,
male volunteers were randomised to consume 0.6 % of energy trans alpha-linolenic
acid or to continue with a diet 'low' in trans alpha-linolenic acid for 6 weeks.
SETTING: Three European university research departments supported by the research
and development departments of the food industry. SUBJECTS: Male volunteers (88)
recruited by local advertisement. METHODS: Replacement of 30 % of the fat of the
habitual diet by margarine, oil and foods. Rapeseed oil was deodorised especially
to produce the trans 'free' and 'high' trans foods for this study. The
incorporation and conversion of trans alpha-linolenic acid into plasma lipids and
platelets was assessed by gas chromatography and dietary compliance was verified
by 4-d weighed record. RESULTS: Less trans alpha-linolenic acid isomers are
incorporated into human plasma lipids in French volunteers than in Dutch or
Scottish volunteers consuming their habitual diets. Trans 'free' alpha-linolenic
acid-rich oil can be produced by careful deodorization during refining. The
'high' trans diet provided 1410+/-42 mg/d trans isomers of alpha-linolenic acid,
whilst the 'low' trans group consumed 60+/-75 mg/d. The change in plasma lipid
and platelet fatty acid composition documented that trans linolenic isomers are
incorporated and converted to a trans isomer of eicosapentaenoic acid. Only the
15-trans alpha-linolenic acid is incorporated into plasma cholesteryl esters. The
group consuming low trans diet had a slightly higher intake of fat, especially
saturated and monounsaturated fat. CONCLUSIONS: Trans 'free' rapeseed oil, rich
in alpha-linolenic acid, can be produced by careful deodorization. Dietary
records show good compliance. Dietary trans isomers of alpha-linolenic acid are
incorporated in plasma lipids and converted to long-chain polyunsaturated fatty
acids. Their effects on risk factors for coronary heart disease and their
metabolism will be reported elsewhere. SPONSORSHIP: European Commission (FAIR 95
0594 grant). European Journal of Clinical Nutrition (2000) 54, 104-113
PMID- 10694781
TI - Infant-feeding patterns are related to blood cholesterol concentration in
prepubertal children aged 5-11 y: the Fleurbaix-Laventie Ville Sante study.
AB - OBJECTIVE: Several studies, mainly in animals, but also in humans, have shown
that diet in infancy is associated with differences in blood cholesterol
concentrations later in life. The objective was to examine this relationship in
children aged 5-11 y after taking into account their current diet and parental
hypercholesterolemia. SETTING AND SUBJECTS: 251 prepubertal boys and 223
prepubertal girls enrolled in the schools in two little towns in northern France.
DESIGN AND METHODS: Cross-sectional evaluation including measurements of
cholesterol concentrations on capillary blood and a single weekday food intake
record. Infant feeding patterns were obtained by questionnaire given to the
mothers. RESULTS: 50% of the children had been breast-fed for a median duration
of less than 2 months. Cow's milk was introduced in the diet as whole milk for
33% of the children. After adjustment for age, height, and sibship, capillary
cholesterol concentration was lower in boys who had been breast fed (geometric
mean: 4.4, 95% confidence interval of the mean: 4.2-4.6 mmol/L) than in those fed
with formula (4.7, 4.5-4.8 mmol/L, P<0.03). In girls, breastfeeding had no
significant effect on blood cholesterol concentration, which was associated with
the type of cow's milk given in infancy: whole milk: 4.9 mmol/L (4.7-5. 2);
totally or partially skimmed milk: 4.5 mmol/L (4.2-4.6), P<0.008. The current
saturated fat and cholesterol intakes and parental hypercyholesterolemia were
associated with current blood cholesterol concentration in children, but did not
modify its relationship with infant feeding patterns. CONCLUSION: Results of the
present study suggest that diet in infancy may have longstanding effect on lipid
metabolism. SPONSORSHIP: The study was supported by funds from Eridania Beghin
Say, Groupe Fournier, Lesieur and Nestle France, Roche Diagnostic and of the MGEN
(Mutuelle Generale de l'Education Nationale, contract INSERM-MGEN #9158) and a
grant from the Association de Langue Francaise pour l'Etude du Diabete et du
Metabolisme (ALFEDIAM). European Journal of Clinical Nutrition (2000) 54, 114-119
PMID- 10694782
TI - Digestibility of cocoa butter from chocolate in humans: a comparison with corn
oil.
AB - OBJECTIVE: To compare, in humans, the digestibility of moderate amounts of cocoa
butter (30.7 g/d) consumed in the form of chocolate as part of a normal western
diet with that of a well-absorbed fat (corn oil); and hence determine whether, by
virtue of its apparent low absorption, cocoa butter can be considered to be a low
calorie fat. DESIGN: Randomised, two-period crossover metabolic study, conducted
under free-living conditions, but with strict control over food intake. SETTING:
Metabolic Unit, Nestle Research Center Lausanne. SUBJECTS: Twelve healthy men
were selected from volunteers at the Nestle Research Center and all subjects
completed the study. INTERVENTION: Two treatment periods of two weeks each: cocoa
butter and control periods, with strict dietary control separated by a two week
wash out period. RESULTS: No differences (P>0.05) were observed in faecal weight
(wet or dry), faecal fat nor in defecation frequency between treatments (cocoa
butter and corn oil). Cocoa butter at a dose of 30.7 g/d in the form of black
chocolate, consumed between two meals, was found to have a similar digestibility
to that of corn oil (99 % of corn oil digestibility). CONCLUSION: Cocoa butter,
consumed as back chocolate within a normal mixed diet, has a high digestibility,
similar to that of corn oil, and a digestible energy value of 37 kJ/g in man.
Thus, cocoa butter cannot be considered to be a low-calorie fat. SPONSORSHIP:
Nestec Ltd, Switzerland. European Journal of Clinical Nutrition (2000) 54, 120
125
PMID- 10694783
TI - Association between trans fatty acid intake and cardiovascular risk factors in
Europe: the TRANSFAIR study.
AB - BACKGROUND: High intakes of trans fatty acids (TFA) have been found to exert an
undesirable effect on serum lipid profiles, and thus may increase the risk for
cardiovascular disease. OBJECTIVES: Investigation of the association between TFA
intake and serum lipids. DESIGN: Cross-sectional study in eight European
countries (Finland, France, Greece, Iceland, The Netherlands, Portugal, Spain,
Sweden) among 327 men and 299 women (50-65 y). Using a dietary history method,
food consumption was assessed and TFA intake was calculated with recent figures
on TFA levels of foods, collected in the TRANSFAIR study. RESULTS: Mean (+/-s.d.)
TFA intake was 2.40+/-1.53 g/day for men and 1.98+/-1.49 g/day for women (0.87+/
0.48% and 0. 95+/-0.55% of energy, respectively), with the highest consumption in
Iceland and the lowest in the Mediterranean countries. No associations were found
between total TFA intake and LDL, HDL or LDL/HDL ratio after adjustment for
cardiovascular risk factors. Additional adjustment for other fatty acid clusters
resulted in a significant inverse trend between total TFA intake and total
cholesterol (Ptrend<0.03). The most abundantly occurring TFA isomer, C18:1 t,
contributed substantially to this inverse association. The TFA isomers C14:1 t9,
C16:1 t9 and C22:1 t were not associated or were positively associated with LDL
or total cholesterol. CONCLUSIONS: From this study we conclude that at the
current European intake levels of trans fatty acids they are not associated with
an unfavourable serum lipid profile. SPONSORSHIP: Unilever Research Laboratorium,
the Dutch Dairy Foundation on Nutrition and Health, Cargill BV, the Institute of
Food Research Norwich Laboratory, the Nutrition Branch of the Ministry of
Agriculture, Fisheries and Food, the International Fishmeal and Oil
Manufacturers' Association, Kraft Foods, NV Vandemoortele Coordination Center,
Danone Group, McDonalds Deutschland Inc, Danish Veterinary and Food
Administration, Valio Ltd, Raisio Group. European Journal of Clinical Nutrition
(2000) 54, 126-135
PMID- 10694784
TI - Daily consumption of (red) meat or meat products in Switzerland: results of the
1992/93 Swiss Health Survey.
AB - OBJECTIVE: The present study aimed to examine the frequency of daily meat and
meat product consumption and the preference for red meat in Switzerland. DESIGN:
Cross-sectional Study. SETTINGS AND SUBJECTS: Data were taken from the 1992/1993
Swiss Health Survey, which collected data on a random sample of persons aged 15
and over, living in Switzerland. The survey, which had a response rate of 71%,
included 7930 male and 7358 female respondents. Bivariate analyses and
multivariate logistic regressions controlling for sociodemographic and lifestyle
factors were performed. RESULTS: Daily consumption of meat or meat products (25%)
and more frequent consumption of red than white meat (26% of meat eaters) were
prevalent in Switzerland. Men, middle-aged persons, participants with a low level
of education, persons living in the German or Francophone regions of Switzerland,
those with Swiss nationality, smokers, overweight and obese people, those with
daily alcohol consumption and physically inactive persons were found to consume
daily meat or meat products more frequently. A preference for red meat rather
than white meat was more often observed in men, young people, persons living in
the German or Francophone regions of Switzerland, smokers and participants who
consumed alcohol at least once daily. CONCLUSIONS: The analysis of data from the
1992/1993 Swiss Health Survey shows that in specific subgroups of the Swiss
population meat and meat product consumption is still more frequent than
recommended, but crude comparisons with older and more recent studies indicate a
decrease in meat consumption. The observed clustering of daily meat consumption
with other risk factors underscores the necessity to include dietary
recommendations in health programs addressing other unhealthy lifestyles.
European Journal of Clinical Nutrition (2000) 54, 136-142
PMID- 10694785
TI - Prediction of dietary flavonol consumption from fasting plasma concentration or
urinary excretion.
AB - OBJECTIVES: to predict flavonols content of the habitual diets of free-living
subjects from urine and plasma concentrations of flavonols. DESIGN: Ten type 2
diabetic patients (five male, five female), mean age 60 (s.e.m. 7) y and BMI 30.2
(s.e.m. 3.5) kg/m2 were treated in a random crossover design for a 2 week period
on either a low flavonoid diet or on the same diet supplemented at one of two
high flavonols levels (total 77.3 or 110.4 mg/day) provided by supplements of
1500 ml tea daily and 400 g fried white onion in olive oil with and without
tomato ketchup and herbs. SETTING: Glasgow Royal Infirmary, University of
Glasgow, Scotland. MAIN OUTCOME MEASURES: Fasting plasma concentration, urine
concentration and 24 h excretion of quercetin, isorhamnetin, kaempferol and
myricetin. RESULTS: Plasma flavonol concentration (r=0.750, P=0.001), 24 h urine
concentration (r=0.847, P=0.001) and 24 h urine excretion (r=0.728, P=<0.001)
were all highly significantly related to dietary intake and gave similar
estimates of intakes. Fasting plasma flavonols concentrations on habitual diets
ranged from 0 to 43.7 ng/ml mean. Regression equations were constricted: total
flavonols intake r=0.74, P<0.001 and quercetin intake r=0.744, P<0. 001. From
these equations, flavonol intakes from habitual diets were estimated at 17-50,
mean 35 mg/day. Of this, 91% was from quercetin. CONCLUSIONS: Dietary flavonols
are absorbed and appear in plasma and urine as potential biomarkers in
concentrations related quantitatively to intake. Estimation of dietary intake
from plasma or urine concentrations appears possible. SPONSORSHIP: Rank Prize
Funds and Rank Foundation of the Department of Human Nutrition; Ministry of
Health and Medical Education, IR Iran. European Journal of Clinical Nutrition
(2000) 54, 143-149
PMID- 10694786
TI - The habitual diet in rural and urban Cameroon.
AB - OBJECTIVE: To evaluate the habitual diet of a rural and urban population in
Cameroon, Central Africa. SETTING: An urban area-Cite Verte Housing District,
Yaounde (1058 subjects); and a rural area-three villages in Evodoula, Cameroon
(746 subjects). SUBJECTS: Cameroonian men and women of African origin (1058
urban, and 746 rural), aged 24-74 y. METHODS: The habitual diet was estimated
with an interviewer-administered food frequency questionnaire. MAIN OUTCOME
MEASURES: Macro- and micronutrient intake. RESULTS: The intake of energy, fat and
alcohol was higher in rural men and women than in urban subjects. In rural women,
the intake of carbohydrates and protein was also higher. The intakes of fibre,
iron, carotene, zinc, potassium, and of the vitamins C, D and E were all higher
in rural men and women than in their urban counterparts. The intake of retinol
was lower in rural subjects than in urban subjects. Eight of the 10 foods eaten
in the highest amount and contributing most to energy intake differed between the
rural and urban population. CONCLUSION: The habitual diet in rural Cameroon
contains more fat and alcohol than the diet in urban Cameroon. The high physical
activity in the rural area may explain the lower levels of the cardiovascular
risk factors in this area compared to those of the urban dwellers. SPONSORSHIP:
This work was supported by a grant from the European Union (contract no. TS3*CT92
0142) and by the Conseil Regional d'Ile de France and INSERM. European Journal of
Clinical Nutrition (2000) 54, 150-154
PMID- 10694787
TI - Histamine plasma levels and elimination diet in chronic idiopathic urticaria.
AB - OBJECTIVE: The aim of this study was to evaluate the effects of an oligoantigenic
and histamine-free diet on patients affected with chronic idiopathic urticaria
(CIU). DESIGN: Ten patients with chronic idiopathic urticaria were prescribed an
oligoantigenic and histamine-free diet for 21 days, followed by serial and
controlled reintroduction of foods during a further 70 days. Modification in
clinical illness as well as histamine plasma levels, post-heparin plasma diamine
oxidase (DAO) and intestinal permeability were evaluated. RESULTS: The
oligoantigenic and histamine-free diet induced a significant improvement of
symptoms (P<0.05). Moreover, CIU patients on free diet showed higher histamine
plasma levels (P<0. 05 vs post-diet and vs controls) that fell to control levels
during the oligoantigenic and histamine-free diet. Post-heparin plasma diamine
oxidase values were slightly reduced and were unchanged during the diet as well
as intestinal permeability, which was always normal in all patients. CONCLUSIONS:
These data suggest that histamine plays a major role in chronic idiopathic
urticaria. The finding of normal intestinal permeability suggests that a
morphological damage of intestinal mucosa should be excluded in these patients.
However, the presence of low levels of post-heparin plasma diamine oxidase may
indicate a subclinical impairment of small bowel enterocyte function that could
induce a higher sensitivity to histamine-rich or histamine-producing food.
European Journal of Clinical Nutrition (2000) 54, 155-158
PMID- 10694788
TI - Education and nutrient intake in Dutch elderly people. The Rotterdam Study.
AB - OBJECTIVE: Unfavourable dietary habits might explain a part of the increased
cardiovascular morbidity and mortality among the lower socioeconomic groups. The
aim of the study was to describe differences in dietary intake in older subjects
by socioeconomic status, as indicated by educational level. DESIGN: A cross
sectional analysis of socioeconomic status in relation to dietary intake.
SETTING: The Rotterdam Study. SUBJECTS: 2213 men and 3193 women, aged 55 y and
over living between 1990 and 1993 in a district of Rotterdam, The Netherlands.
METHODS: Dietary data were assessed with a semiquantitative food frequency
questionnaire, containing 170 food items in 13 food groups. RESULTS: In general,
the dietary differences between socioeconomic groups were small. Lower educated
subjects had a higher intake of almost all macronutrients compared with higher
educated subjects. The total energy intake of men/women with the lowest
educational level differed from those with the highest education in the following
respect: 9.60/7.54 vs 8.94/7.17 MJ/day. Furthermore, fat composition was more
adverse in the lower educated strata; in lower educated subjects, relatively more
energy was derived from saturated fat (14.5/14.6 vs 13.8/13.8 energy%), the ratio
of polyunsaturated saturated fat was lower (for men: 0.50 vs 0. 55) and the
intake of cholesterol higher (271/220 vs 240/204 mg/day). These differences could
be explained by a higher intake of visible fat (46/37 vs 44/34 g/day) and more
meat consumption (130/100 vs 116/86 g/day). In addition, the composition of these
products differed: the higher educated used relatively more lean meat and low-fat
milk products. Furthermore, the intake of fibre was lower among the lower
educated (1.88/2.17 vs 2.03/2.29 g/MJ). Among lower educated groups there were
more abstainers (15.5/31.5 vs 12.3/26.9%) and the type of alcoholic beverages
also differed between the groups. Intake of antioxidant vitamins from food alone
did not differ between educational groups. CONCLUSIONS: In Dutch elderly people,
there are socioeconomic differences in dietary intake. Although these differences
are small, these findings support the role of diet in the explanation of
socioeconomic inequalities in cardiovascular health. SPONSORSHIP: Erasmus Centre
for Research on Aging, Erasmus University Rotterdam. European Journal of Clinical
Nutrition (2000) 54, 159-165
PMID- 10694789
TI - The influence of survey duration on estimates of food intakes and its relevance
for public health nutrition and food safety issues.
AB - OBJECTIVE: To examine the influence of food consumption survey duration on
estimates of percentage consumers, mean total population intakes and intakes
among consumers only and to consider its relevance for public health nutrition
and food safety issues. DESIGN: Prospective food consumption survey. SETTING: A
multicentre study in five centres in the European Union-Dublin, Ghent, Helsinki,
Potsdam and Rome. SUBJECTS: Teenage subjects were recruited through schools; 948
(80%) out of 1180 subjects completed the survey. INTERVENTIONS: 14-day food
diaries were used to collect the food consumption data. RESULTS: For mean total
population intakes, 53% of the foods had slopes significantly different to 0
(P<0.05). In practical terms (g/day), these differences were small, with 41% of
foods having differences of =1 g/day and a further 35% having differences of 1
5 g/day. Estimates of percentage consumers based on 3 days and 14 days were 1.9
and 3.6 times the 1-day estimate, respectively. For 72% of foods, at least 50% of
non-consumers on day 1 became consumers over the subsequent 13 days. Estimates of
mean consumer only intakes based on 3 days and 14 days were 53% and 32% of the 1
day value. CONCLUSION: In practical terms, survey duration influences estimates
of percentage consumers and intakes among consumers only but not mean total
population intakes. Awareness of this influence is important for improved
interpretation of dietary data for epidemiological studies, development of food
based dietary guidelines and food chemical intakes. SPONSORSHIP: The Institute of
European Food Studies, a non-profit research organization based in Trinity
College Dublin. European Journal of Clinical Nutrition (2000) 54, 166-173
PMID- 10694790
TI - Type of alcohol and drinking pattern in 56, 970 Danish men and women.
AB - OBJECTIVE: To describe drinking patterns among individuals who prefer drinking
wine, beer or spirits. DESIGN: Cross-sectional study obtaining detailed
information on intake of wine, beer and spirits and on frequency of alcohol
intake. Adjustment for gender, age, smoking habits, educational attainment and
body mass index. SETTING: Denmark. SUBJECTS: 27, 151 men and 29, 819 women,
randomly selected from Copenhagen and Aarhus, Denmark. MAIN OUTCOME MEASURES:
Drinking pattern-steady or binge drinking. RESULTS: A vast majority (71%) of both
men and women preferred wine or beer. At all levels of total alcohol intake, beer
drinkers were most likely to be frequent drinkers. Thus, light drinkers of beer
had an odds ratio for being frequent drinkers of 1.97 (95% confidence limits 1.50
2.58) as compared to light drinkers of wine (total alcohol intake 3-30 drinks per
month), while people who preferred beer had an odds ratio of 1. 29 (1.19-1.40)
compared with wine drinkers in the moderate drinking category (31-134 drinks per
month). There were no significant differences in total alcohol intake between
individuals preferring different alcoholic beverages. CONCLUSION: If binge
drinking is less healthy than steady drinking, the relation between wine intake
and coronary heart disease mortality could be subject to negative confounding,
since beer drinkers seem to have the most sensible drinking pattern. SPONSORSHIP:
Danish Cancer Society and the Danish National Board of Health. European Journal
of Clinical Nutrition (2000) 54, 174-176
PMID- 10694791
TI - Wine drinking and diet in Italy.
AB - OBJECTIVE: To investigate the relation between wine drinking and intake of
selected indicator foods, which may vary in various populations. DESIGN: Cross
sectional analysis of the comparison group of a case- control study. SETTING: A
network of teaching and general hospitals from six Italian areas. SUBJECTS: 5642
control subjects (3261 females and 2381 males) aged 20-74 y (median age 58 y),
admitted for acute, non-neoplastic conditions unrelated to alcohol consumption.
Participation rate was over 95%. INTERVENTION: Trained interviewers collected
information using a structured and validated questionnaire. The average intakes
of selected food items were computed, together with the multivariate odds ratios
(OR) of eating above the median of each food. RESULTS: No appreciable difference
in either sex for any food indicator considered (fruit, raw vegetables, cooked
vegetables, salad and fish) was observed between abstainers, wine, and other
alcoholic beverage drinkers. If anything, female wine drinkers reported less
frequently high consumption of salad (OR=0.8) and raw vegetables (OR=0.8), both
estimates being of borderline significance. CONCLUSIONS: In no instance did wine
drinkers or mixed drinkers (who include a large proportion of wine drinkers, too)
show an association with indicators of healthy diet. SPONSORSHIP: Italian
Association for Cancer Research, Milan, Italy. European Journal of Clinical
Nutrition (2000) 54, 177-179
PMID- 10694792
TI - Isocaloric protein supplementation during pregnancy.
PMID- 10694793
TI - Prospects for gene therapy of diabetes mellitus.
PMID- 10694794
TI - Efficient gene transfer into human cord blood CD34+ cells and the CD34+CD38-
subset using highly purified recombinant adeno-associated viral vector
preparations that are free of helper virus and wild-type AAV.
AB - Recombinant adeno-associated viral (rAAV) vectors have been evaluated for their
ability to transduce primitive hematopoietic cells. Early studies documented rAAV
mediated gene expression during progenitor derived colony formation in vitro, but
studies examining genome integration and long-term gene expression in
hematopoietic cells have yielded conflicting results. Such studies were performed
with crude vector preparations. Using improved methodology, we have generated
high titer, biologically active preparations of rAAV free of wild-type AAV (less
than 1/107particles) and adenovirus. Transduction of CD34+ cells from umbilical
cord blood was evaluated with a bicistronic rAAV vector encoding the green
fluorescent protein (GFP) and a trimetrexate resistant variant of dihydrofolate
reductase (DHFR). Freshly isolated, quiescent CD34+ cells were resistant to
transduction (less than 4%), but transduction increased to 23 +/- 2% after 2 days
of cytokine stimulation and was further augmented by addition of tumor necrosis
factor alpha (51 +/- 4%) at a multiplicity of infection of 106. rAAV-mediated
gene expression was transient in that progenitor derived colony formation was
inhibited by trimetrexate. Primitive CD34+ and CD34+, CD38- subsets were
sequentially transduced with a rAAV vector encoding the murine ecotropic receptor
followed by transduction with an ecotropic retroviral vector encoding GFP and
DHFR. Under optimal conditions 41 +/- 7% of CD34+ progenitors and 21 +/- 6% of
CD34+, CD38- progenitors became trimetrexate resistant. These results document
that highly purified rAAV transduce primitive human hematopoietic cells
efficiently but gene expression appears to be transient. Gene Therapy (2000) 7,
183-195.
PMID- 10694795
TI - Efficient and sustained transgene expression in human corneal cells mediated by a
lentiviral vector.
AB - The development of vectors and techniques able to transfer potentially
therapeutic genetic information to corneal tissues efficiently may have broad
clinical applications. Although a variety of vectors have been tested for their
ability to transduce corneal tissue, these systems have been ineffective at
transducing all cell types or have been associated with a relatively short
duration of transgene expression. Towards the implementation of efficient, long
term transgene expression in all corneal cell types, we have studied the ability
of a recombinant lentiviral vector, containing the enhanced green fluorescent
protein (eGFP), to mediate gene transfer into human corneal tissue in vitro and
in situ. Human primary keratocytes, cultured in vitro, were efficiently
transduced by a lentiviral vector as determined by fluorescent-activated cell
sorting (FACS) and by fluorescent microscopy. Transduction efficiency was found
to be dependent upon multiplicity of infection (MOI); 92% of keratocytes were
transduced at an MOI of 1000. The proportion of eGFP-positive cells remained
unchanged throughout continuous culture for 60 days, indicating stable expression
and a lack of selective pressure for or against transduced cells. Human corneal
tissue, obtained at the time of penetrating keratoplasty, demonstrated efficient
in situ transduction with this vector. Endothelial cells, epithelial cells and
stromal keratocytes at the exposed cut edge of the corneal tissue in situ
demonstrated eGFP expression. Underlying stromal cells not in direct contact with
vector-containing media, were not transduced, implying that virus-cell contact is
required for transduction. Transduced corneal tissues expressed eGFP in situ for
the life of the corneal button in extended organ culture (60 days). These results
imply that lentiviral vectors may prove to be useful tools, able to transduce
corneal tissue efficiently, and that transgene expression is temporally stable.
Gene Therapy (2000) 7, 196-200.
PMID- 10694796
TI - Prevention of the dystrophic phenotype in dystrophin/utrophin-deficient muscle
following adenovirus-mediated transfer of a utrophin minigene.
AB - Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disorder caused
by the lack of a subsarcolemmal protein, dystrophin. We have previously shown
that the dystrophin-related protein, utrophin is able to compensate for the lack
of dystrophin in the mdx mouse, the mouse model for DMD. Here, we explore whether
utrophin delivered to the limb muscle of dystrophin/utrophin-deficient double
knockout (dko) neonatal mice can protect the muscle from subsequent dystrophic
damage. Utrophin delivery may avoid the potential problems of an immune response
associated with the delivery of dystrophin to a previously dystrophin-deficient
host. Dko muscle (tibialis anterior) was injected with a first generation
recombinant adenovirus containing a utrophin minigene. Up to 95% of the fibres
continued expressing the minigene 30 days after injection. Expression of utrophin
caused a marked reduction from 80% centrally nucleated fibres (CNFs) in the
uninjected dko TA to 12% in the injected dko TA. Within the region of the TA
expressing the utrophin minigene, a significant decrease in the prevelance of
necrosis was noted. These results demonstrate that the utrophin minigene
delivered using an adenoviral vector is able to afford protection to the
dystrophin/utrophin-deficient muscle of the dko mouse. Gene Therapy (2000) 7, 201
204.
PMID- 10694797
TI - Glucose regulated production of human insulin in rat hepatocytes.
AB - Insulin gene therapy requires that insulin secretion be coupled to metabolic
requirements. To this end, we have developed an insulin transgene whose
transcription is stimulated by glucose and inhibited by insulin. Glucose- and
insulin-sensitive promoters were constructed by inserting glucose-responsive
elements (GlREs) from the rat L-pyruvate kinase (L-PK) gene into the insulin
sensitive, liver-specific, rat insulin-like growth factor binding protein-1
(IGFBP-1) promoter. Glucose (5 to 25 mM) stimulated, and insulin (10-10 to 10-7
M) inhibited, luciferase expression driven by these promoters in primary cultured
rat hepatocytes. The capacity of transfected hepatocytes to secrete mature,
biologically active insulin was demonstrated using a human proinsulin cDNA
(2xfur), modified to allow protein processing by endogenous endopeptidase
activity. Medium conditioned by insulin-producing hepatocytes contained greater
than 300 microU/ml immunoreactive insulin, while denaturing SDS-PAGE of an anti
insulin immunoprecipitate revealed bands with the mobilities of insulin A, and B
chains. Biological activity of hepatocyte-produced insulin was demonstrated in a
transfection assay, in which medium conditioned by insulin-producing hepatocytes
exerted an effect similar to 10-7 M insulin. We then combined the glucose- and
insulin-sensitive promoter with the modified human proinsulin cDNA to create a
metabolically sensitive insulin transgene ((GlRE)3BP-1 2xfur). In both H4IIE
hepatoma cells stably transfected with this construct, and normal rat hepatocytes
(GlRE)3BP-1 2xfur-mediated insulin secretion increased in response to stimulation
by glucose. Moreover, a capacity to decrease insulin production in response to
diminishing glucose exposure was also demonstrated. We conclude that the
transcriptional regulation of insulin production using these glucose- and insulin
sensitive constructs meets the requirements for application in a rodent model of
insulin gene therapy. Gene Therapy (2000) 7, 205-214.
PMID- 10694798
TI - An in vitro system for efficiently evaluating gene therapy approaches to
hemoglobinopathies.
AB - A variety of gene therapy strategies are under development for the treatment of
sickle cell anemia and other hemoglobinopathies. A number of alternative vectors
have been developed to transfer and express the beta-globin gene and other
therapeutic molecules, but none has resulted in efficient transduction and stable
long-term expression in primary hematopoietic cells. One reason for this problem
is that most vectors are initially evaluated in immortalized cell lines which may
not faithfully recapitulate the biology of primary erythroid cells. In order to
provide a more relevant system for efficiently evaluating alternative vector
constructs for beta-globin disorders, we have developed (1) a simple method for
generating primary human red blood cell (RBC) precursors in liquid culture
established with mononuclear cells obtained from normal donors as well as
patients with Hb SC disease; (2) a high titer retroviral vector which can be
easily modified to optimize gene transfer and transgene expression; and (3)
methods for transducing the RBC precursors at high efficiency. The development of
simple and efficient methods and reagents for generating and transducing primary
human RBC precursors provides a facile and effective means for screening
alternative gene therapy strategies. Gene Therapy (2000) 7, 215-223.
PMID- 10694799
TI - Secreted human beta-glucuronidase: a novel tool for gene-directed enzyme prodrug
therapy.
AB - A major problem of tumor gene therapy is the low transduction efficiency of the
currently available vectors. One way to circumvent this problem is the delivery
of therapeutic genes encoding intracellular enzymes for the conversion of a
prodrug to a cytotoxic drug which can then spread to neighboring non-transduced
cells (bystander effect). One possibility to improve the bystander effect could
be the extracellular conversion of a hydrophilic prodrug to a lipophilic, cell
permeable cytotoxic drug. Toward this end, we have used a secreted form of the
normally lysosomal human beta-glucuronidase (s-betaGluc) to establish an
extracellular cytotoxic effector system that converts an inactivated
glucuronidated derivative of doxorubicin (HMR 1826) to the cytotoxic drug. We
demonstrate that s-betaGluc-transduced tumor cells convert HMR 1826 to
doxorubicin which is taken up by both transduced and non-transduced cells. s
betaGluc in combination with HMR 1826 efficiently induces tumor cell killing both
in cell culture and in vivo. This effect is mediated through a pronounced
bystander effect of the generated cytotoxic drug. Most notably, this gene
therapeutic strategy is shown to be clearly superior to conventional chemotherapy
with doxorubicin. Gene Therapy (2000) 7, 224-231.
PMID- 10694800
TI - Myocardial gene transfer by selective pressure-regulated retroinfusion of
coronary veins.
AB - Catheter-based percutaneous transluminal gene delivery (PTGD) into the coronary
artery still falls behind the expectations of an efficient myocardial gene
delivery system. In this study gene delivery was applied by selective pressure
regulated retroinfusion through the coronary veins to prolong adhesion of
replication defective adenovirus within the targeted myocardium. Adenoviral
vectors consisted either of luciferase (Ad.rsv-Luc) or beta-galactosidase (Ad.rsv
betaGal) reporter gene under control of an unspecific promotor derived from the
Rous sarcoma virus (RSV). In this pig model, selective retrograde gene delivery
into the anterior cardiac vein during a brief period of ischemia substantially
increased reporter gene expression in the targeted myocardium (LAD region)
compared with antegrade delivery as a control. Repeated retrograde delivery
during two periods of brief ischemia resulted in a more homogeneous transmural
expression predominantly observed in cardiomyocytes (X-gal-staining). In the
nontargeted myocardium (CX region) there was no evidence for adenoviral
transfection. From our data we infer that selective pressure-regulated
retroinfusion is a promising approach for efficient percutaneous transluminal
gene delivery to the myocardium. Gene Therapy (2000) 7, 232-240.
PMID- 10694801
TI - Adenovirus-mediated ribozyme targeting of HER-2/neu inhibits in vivo growth of
breast cancer cells.
AB - HER-2/neu is overexpressed in 25-30% of human breast cancers. We prepared an anti
HER-2/neu hammerhead ribozyme expressed by a recombinant adenovirus (rAdHER-Rz).
Human breast cancer cell lines were transduced with high efficiency, resulting in
decreased HER-2/neu expression. In vivo injections of rAdHER-Rz into BT-474
tumors established in nude mice inhibited tumor growth to 20% of mock-treated
controls. Similar in vivo effects were shown in MCF-7 cells, which do not
overexpress HER-2/neu. The growth inhibitory effects of rAdHER-Rz were greater
than those of an antisense-expressing vector. These results suggest the utility
of anti-HER-2/neu ribozymes as a rational strategy for gene therapy of breast
cancer. Gene Therapy (2000) 7, 241-248.
PMID- 10694802
TI - Efficient transduction of mature CD83+ dendritic cells using recombinant
adenovirus suppressed T cell stimulatory capacity.
AB - We have developed a culture method for the foreign serum-free generation of
highly immunostimulatory, CD83+ human dendritic cells (DC). In this study, we
evaluated the feasibility and consequences of endogenously expressing antigens in
mature DC using adenoviral vectors. Transduction of DC with Ad-EGFP demonstrated
endogenous fluorescence in 50-85% of CD83+ DC. Ad-transduced DC stimulated the
proliferation of allogeneic CD8+ and CD4+ T cells at low DC: T cell ratios.
However, at high DC: T cell ratios the stimulatory capacity of Ad-transduced DC
was suppressed. This immunosuppressive effect was confirmed by demonstrating that
the stimulatory function of untreated DC could be suppressed in a dose-dependent
manner by addition of Ad-transduced DC. Furthermore, transwell experiments
suggested that direct cell contact was required. Taken together, our results
demonstrate the feasibility of efficiently expressing antigens in CD83+ DC using
adenoviruses. However, immunosuppressive effects must be considered and carefully
studied before Ad-transduced DC are employed for clinical trials. Gene Therapy
(2000) 7, 249-254.
PMID- 10694803
TI - The macrophage - a novel system to deliver gene therapy to pathological hypoxia.
AB - The use of activated macrophages in the treatment of cancer has been largely
ineffectual. By 'arming' these cells with the ability to express a therapeutic
gene we demonstrate significant advances in the efficacy of this approach. We
have used a hypoxia-regulated adenoviral vector to transduce human macrophages
with either a reporter or a therapeutic gene encoding human cytochrome P4502B6
(CYP2B6). Infiltration of transduced macrophages into a tumour spheroid results
in induction of gene expression. We demonstrate significant tumour cell killing
only in the presence of cyclophosphamide via activation by P4502B6 and show that
this can be further targeted to tumours through hypoxia regulated gene
expression. Gene Therapy (2000) 7, 255-262.
PMID- 10694804
TI - Gene transfer into inflamed glomeruli using macrophages transfected with
adenovirus.
AB - In vivo gene transfer to sites of inflammatory disease provides a novel method
both for studying the effects of cytokines and growth factors, and for
therapeutic intervention. Macrophages play a pivotal role in the development and
control of inflammation and are therefore logical cells to use for genetic
modification and in vivo gene delivery. In this study we show that macrophages
(both cell lines and primary cultures) can be transfected by recombinant
adenoviruses expressing beta-galactosidase, that the macrophages become activated
by the transfection process as determined by generation of nitric oxide and can
be easily manipulated to localise to inflamed glomeruli after direct injection
into the renal artery of rats with an experimentally induced glomerular
inflammation caused by nephrotoxic nephritis. The injection of transfected
macrophages reduces the severity of injury in this model of glomerulonephritis as
shown by a reduction in the degree of albuminuria. This approach provides a
favourable system for gene delivery in inflammatory disease and shows that both
the functional properties of the transfected macrophage as well the transgene it
is engineered to produce are relevant for in vivo gene transfer. Gene Therapy
(2000) 7, 263-270.
PMID- 10694805
TI - Insertion vectors for gene therapy.
PMID- 10694806
TI - Cationic lipid-mediated gene transfer to the growing murine and human airway.
AB - Gene therapy in patients with cystic fibrosis may need to be commenced before the
onset of lung disease which may be evident as early as 4 weeks after birth. We
assessed the efficacy of cationic lipid-mediated transfer of a reporter gene,
chloramphenicol acetyltransferase, in the growing murine and human respiratory
tract. Gene expression was greater in adult mice (greater than 8 weeks old)
compared with 9- and 16-day-old animals, despite a relatively greater proportion
of complex delivered to the younger mice. Subsequent experiments compared 16-day
old and adult mice. Whilst higher gene expression occurred in the parenchyma
compared with conducting airways in both groups, significantly greater expression
was seen in the conducting airway of adult mice compared with 16-day-old animals.
This expression persisted beyond 18 days in the adults but was undetectable in
the younger group at this time-point. In an ex vivo model there was no difference
in gene expression between the two groups. Further, no differences were observed
in gene expression between growing (age 5 weeks to 14 years 8 months) and adult
human lung tissue in either parenchyma or conducting airway. These data suggest
age-dependent differences in gene transfer in vivo, which are not seen in an ex
vivo setting. Proof-of-principle has been demonstrated for cationic-lipid
mediated gene transfer to the growing human lung. Gene Therapy (2000) 7, 273-278.
PMID- 10694807
TI - Glomerular filtration is required for transfection of proximal tubular cells in
the rat kidney following injection of DNA complexes into the renal artery.
AB - Gene transfer to the kidney can be achieved with various DNA vectors, resulting
in transgene expression in glomerular or tubular districts. Controlling transgene
destination is desirable for targeting defined renal cells for specific
therapeutic purposes. We previously showed that injection of polyplexes into the
rat renal artery resulted in transfection of proximal tubular cells. To
investigate whether this process involves glomerular filtration of the DNA
containing particles, fluorescent polyethylenimine polyplexes were prepared,
containing fluoresceinated poly-L-lysine. This allowed visualization of the route
of the particles into the kidney. Our polyplexes were filtered through the
glomerulus, since fluorescent proximal tubuli were observed. Conversely,
fluorescent lipopolyplexes containing the cationic lipid DOTAP were never
observed in tubular cells. Size measurements by laser light scattering showed
that the mean diameter of polyplexes (93 nm) was smaller than that of
lipopolyplexes (160 nm). The size of the transfecting particles is therefore a
key parameter in this process, as expected by the constraints imposed by the
glomerular filtration barrier. This information is relevant, in view of
modulating the physico-chemical properties of DNA complexes for optimal transgene
expression in tubular cells. Gene Therapy (2000) 7, 279-285.
PMID- 10694808
TI - Efficient lipid-mediated gene transfer to articular chondrocytes.
AB - We examined nonviral, lipid-mediated gene transfer methods as potential tools for
efficient transfection of articular chondrocytes. Transfection conditions were
determined for primary cultures of normal human articular, osteoarthritic human
articular and normal bovine articular chondrocytes using a lacZ reporter gene
construct with the commercially available cationic liposomes Cellfectin, DMRIE-C,
LipofectAmine, Lipofectin, LipoTaxi, TransFast and the lipid-based reagent FuGENE
6. Optimized conditions were then evaluated in an ex vivo model of chondrocyte
transplantation. FuGENE 6 transfection produced the maximum levels of transgene
expression. Transfection efficiency was cell type specific and affected by DNA
concentration, lipid/DNA ratio and the presence of hyaluronidase, a matrix
degrading enzyme. Analysis of X-gal staining demonstrated an efficiency of 41.0%
in normal bovine articular chondrocytes, 20.7% in normal human articular
chondrocytes and 7.8% in osteoarthritic human chondrocytes. Transfected
chondrocytes were found to successfully populate the articular cartilage surface
in explant cultures. Transplanted genetically modified chondrocytes adhered to
the articular cartilage and continued to produce beta-galactosidase for 2 weeks.
This evaluation and optimization of lipid-based gene transfer into articular
chondrocytes may serve as a useful tool in studies of genes involved in articular
cartilage damage and repair and as a potential delivery method for therapeutic
genes. Gene Therapy (2000) 7, 286-291.
PMID- 10694809
TI - Mannose receptor-mediated gene transfer into macrophages using novel mannosylated
cationic liposomes.
AB - A novel mannosylated cholesterol derivative, cholesten-5-yloxy-N-(4-((1-imino-2
beta-D-thiomannosyl -ethyl)amino)bu tyl) formamide (Man-C4-Chol), was synthesized
in order to perform mannose receptor-mediated gene transfer with liposomes.
Plasmid DNA encoding luciferase gene (pCMV-Luc) complexed with liposomes,
consisting of a 6:4 mixture of Man-C4-Chol and dioleoylphosphatidylethanolamine
(DOPE), showed higher transfection activity than that complexed with 3beta[N-(N',
N'-dimethylaminoethane)-carbamoyl]cholesterol (DC-Chol)/DOPE(6:4) and N-[1-(2,3
dioleyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTMA)/DOPE(1:1) liposomes
in mouse peritoneal macrophages. The presence of 20 mM mannose significantly
inhibited the transfection efficiency of pCMV-Luc complexed with Man-C4-Chol/DC-
Chol/DOPE(3:3:4) and Man-C4-Chol/DOPE(6:4) liposomes. High gene expression of
pCMV-Luc was observed in the liver after intravenously injecting mice with Man-C4
Chol/DOPE(6:4) liposomes, whereas DC-Chol/DOPE(6:4) liposomes only showed marked
expression in the lung. The gene expression with Man-C4-Chol/DOPE(6:4) liposome/
DNA complexes in the liver was observed preferentially in the non-parenchymal
cells and was significantly reduced by predosing with mannosylated bovine serum
albumin. The gene expression in the liver was greater following intraportal
injection. These results suggest that plasmid DNA complexed with mannosylated
liposomes exhibits high transfection activity due to recognition by mannose
receptors both in vitro and in vivo. Gene Therapy (2000) 7, 292-299.
PMID- 10694810
TI - Improved safety and titre of murine leukaemia virus (MLV)-based retroviral
vectors.
AB - Many retroviral vectors based on murine leukaemia virus (MLV) contain the first
420 nucleotides of the gag gene, as this was reported to increase vector titre by
increasing the efficiency of RNA packaging. In this study, deletion of this gag
sequence from its original location did not decrease the titre of two retroviral
vectors, pBabe puro and MFG-S-. The two vectors could be improved by replacing
the gag sequence with a CTE from Mason-Pfizer monkey virus (MPMV). This
substitution improved vector titre, while eliminating a region of homology
between vector and packaging constructs. Gene Therapy (2000) 7, 300-305.
PMID- 10694811
TI - Anti-inflammatory gene therapy directed at the airway epithelium.
AB - Cystic fibrosis (CF) is characterised by chronic airway inflammation. Pro
inflammatory mediators in the lung are regulated by the transcription factor
nuclear factor kappa B (NFkappaB). We have assessed the effect of adenovirus and
liposome-mediated overexpression of the NFkappaB inhibitor IkappaBalpha, as well
as liposome-mediated transfection with oligonucleotides resembling NFkappaB
consensus binding sites (decoys) in a cystic fibrosis airway epithelial cell line
(CFTE). Electrophoretic mobility shift assays (EMSA) were used to assess NFkappaB
activity and secretion of the pro-inflammatory cytokine interleukin-8 (IL-8) was
measured by ELISA. At a MOI of 30, Ad-IkappaBalpha significantly decreased IL-8
secretion to 60% and 43% of control unstimulated and TNF-alpha stimulated cells,
respectively. At this MOI, approximately 70% of cells are transduced. EMSA showed
an approximately 50% decrease in NFkappaB activation. Liposome-mediated
transfection of IkappaBalpha did not reduce IL-8 secretion, probably due to low
transfection efficiency (approximately 5% of cells). Liposome-mediated
transfection of CFTE cells with rhodamine-labeled decoy oligonucleotides
indicated a transfection efficiency close to 100%. TNF-alpha stimulated IL-8
secretion was reduced by approximately 40% using this approach. EMSA confirmed a
significant decrease of NFkappaB activation. Decoy oligonucleotides may be a
promising approach for reduction of NFkappaB-mediated pulmonary inflammation.
Gene Therapy (2000) 7, 306-313.
PMID- 10694812
TI - Expression of human Wiskott-Aldrich syndrome protein in patients' cells leads to
partial correction of a phenotypic abnormality of cell surface glycoproteins.
AB - The Wiskott-Aldrich syndrome (WAS) is an uncommon X-linked recessive disease
characterized by thrombocytopenia, eczema and immunodeficiency. The biochemical
defect of this disorder primarily affects cells derived from bone marrow. To
understand better the molecular mechanisms underlying this disease and to
evaluate the possibility of correcting the genetic defects in hematopoietic
cells, a Moloney murine leukemia virus (MoMLV)- based retroviral vector carrying
a functional Wiskott-Aldrich syndrome protein (WASp) cDNA driven by an SV40
promoter (LNS-WASp) was constructed. A packaging cell line containing this vector
produced a stable level of WAS protein and maintained a high titer of viral
output. Epstein-Barr virus (EBV)-transformed B lymphoblastoid cell lines (B-LCL)
from WAS patients, which lack expression of the WAS protein, were transduced by
the LNS-WASp retroviral vector and showed expression of WASp by Western blot.
Analysis of the O-glycan pattern on cell surface glycoproteins from WAS patients'
B-LCL showed an altered glycosylation pattern, due to increased activity of beta
1, 6-N-acetylglucosaminyltransferase (C2GnT). Transduction by the retroviral
vector carrying the functional WASp cDNA partially restored the abnormal
glycosylation pattern, and was accompanied by a decreasing C2GnT activity. These
findings imply a functional linkage between the WAS protein and the expression of
the glycosyltransferase involved in the O-glycosylation, and also suggest a
potential gene therapy via transferring a functional WASp cDNA into hematopoietic
cells for Wiskott-Aldrich syndrome. Gene Therapy (2000) 7, 314-320.
PMID- 10694813
TI - Inhibition of HIV-1 replication in chronically infected cell lines and peripheral
blood mononuclear cells by retrovirus-mediated antitat gene transfer.
AB - Among potential genetic targets for intervention in the HIV-1 life cycle, the tat
gene product is a key target. We investigated the ability of an antitat gene to
inhibit HIV-1 activation and replication in chronically infected promonocyte (U1)
and T cell (ACH-2) lines in vitro. U1 and ACH-2 cells were transduced with an
antitat gene expressing RNA with dual (polymeric Tat activation response element
and antisense-tat) function that interferes with HIV-1 replication. Tumor
necrosis factor-alpha (TNF-alpha) plus phorbol 12- myristate 13-acetate (PMA)
induced HIV-1 expression, as determined by reverse transcribed PCR and reverse
transcriptase (RT) assays, was significantly inhibited in U1 and ACH-2 cells
transduced with the antitat gene, compared with the cells transduced with control
vector and untransduced cells. This resistance to TNF-alpha plus PMA-induced HIV
1 expression was demonstrated in antitat gene-transduced U1 and ACH-2 cells
maintained in G418-free media for 5 months, suggesting that functional antitat
gene may persist for many months in transduced cells and their progeny. Most
importantly, we demonstrate that the antitat gene, when introduced into
peripheral blood mononuclear cells (PBMC) isolated from patients with HIV-1
infection, inhibited TNF-alpha plus PMA-induced viral replication as determined
by RT-PCR and RT activity. In addition, the antitat gene enhanced the survival of
CD4+ T lymphocytes from such patients. These data suggest the feasibility of
utilizing antitat gene therapy to block activation and replication of HIV-1 in
latently infected monocytes and T- lymphocytes in vivo. Gene Therapy (2000) 7,
321-328.
PMID- 10694814
TI - Adenovirus-mediated lymphotactin gene transfer improves therapeutic efficacy of
cytosine deaminase suicide gene therapy in established murine colon carcinoma.
AB - Lymphotactin (Ltn) is the sole member of C chemokines which attracts T cells and
NK cells specially. Ltn gene was transferred in vivo to improve the antitumor
efficacy of cytosine deaminase (CD) gene therapy. Upregulation of CD80 and CD54
on murine CT26 colon carcinoma cells was observed after combined transfection
with adenovirus encoding CD (AdCD) and adenovirus encoding murine Ltn (AdLtn)
followed by administration of 5-fluorocytosine (5FC) in vitro. AdCD/5FC treatment
also increased the expression of CD95 and induced obvious apoptosis of CT26
cells. After combined treatment with AdLtn and AdCD/5FC, the pre-established
murine model with subcutaneous CT26 colon carcinoma exhibited most significant
tumor growth inhibition, and four of eight tumor-bearing mice were tumor free,
while tumors in other mice grew more progressively. Examination of lymphocyte
infiltration and cytokine gene expression in tumor tissue revealed that tumors
from AdLtn/AdCD/5FC-or AdLtn-treated mice were heavily infiltrated with CD4+,
CD8+ T cells and NK cells, and IL-2 and IFN-gamma mRNA expression were present in
parallel with T cell and NK cell infiltration. Splenic NK and CTL activities
increased significantly after the combination therapy. In vivo depletion analysis
showed that NK cells, CD4+ T cells and CD8+T cells participated in the antitumor
effect of the host with CD8+T cells being the main T cell subset responsible for
the enhanced antitumor immune response. These findings suggested that increased
immunogenicity and induction of apoptosis of the tumor cells, and efficient
induction of local and systemic antitumor immunity of the host might contribute
to the enhanced antitumor effects of the combined Ltn and CD suicide therapy.
Gene Therapy (2000) 7, 329-338.
PMID- 10694815
TI - Activation of lymphocytes by anti-CD3 single-chain antibody dimers expressed on
the plasma membrane of tumor cells.
AB - Activation of cytotoxic T cells without MHC restriction was attempted by
expressing single-chain antibodies (scFv) against CD3 on the surface of tumor
cells. A chimeric protein consisting of a scFv of mAb 145.2C11, the hinge-CH2-CH3
region of human IgG1, and the transmembrane and cytosolic domains of murine CD80
formed disulfide-linked dimers on the plasma membrane of cells and specifically
bound lymphocytes. Anti-CD3 scFv dimers expressed on the cell surface induced
CD25 (IL-2 receptor alpha-chain) expression and proliferation of splenocytes.
CT26 tumor cells engineered to express surface scFv dimers (CT26/2C11) also
induced potent lymphocyte cytotoxicity with or without addition of exogenous IL
2. Splenocytes activated by CT26/2C11 cells also killed wild-type CT26 cells,
indicating that activated splenocytes could kill bystander tumor cells.
Immunization of BALB/c mice with irradiated CT26/2C11 cells did not protect
against a lethal challenge of CT26 cells, suggesting that systemic immunity was
not induced. However, the growth of CT26 tumors containing 50% CT26/2C11 cells
was significantly retarded compared with CT26 tumors, whereas CT26/2C11 tumors
did not grow in syngeneic mice. These results suggest that expression of anti-CD3
scFv dimers on tumors may form the basis for a novel therapeutic strategy for
tumors that exhibit defects in antigen processing or presentation. Gene Therapy
(2000) 7, 339-347.
PMID- 10694816
TI - Drug selection of MDR1-transduced hematopoietic cells ex vivo increases transgene
expression and chemoresistance in reconstituted bone marrow in mice.
AB - The MDR1 (multidrug resistance) gene, transferred to hematopoietic cells, is
expected to protect them from anticancer chemotherapy and may serve as a
selectable marker, restoring gene expression in vivo. Appropriate selection
strategies, however, need to be established. To investigate whether preselection
ex vivo affects chemoresistance, murine bone marrow cells were retrovirally
transduced with high-titer or, as a model for suboptimal gene expression, low
titer retroviruses and exposed to daunomycin or colchicine for 48-96 h. Selection
significantly increased chemoresistance of clonogenic progenitor cells. In tissue
culture, the entire target population was rendered highly drug resistant after
MDR1 transfer with high-titer viruses. If transduction was performed under
suboptimal conditions, drug selection increased the frequency of chemoresistant
colonies up to 40% over the number of unselected cells. Colchicine and daunomycin
were equally efficient in increasing drug resistance ex vivo, but colchicine
preselected cells rescued lethally irradiated mice under conditions where
daunomycin-selected bone marrow cells failed to do so. Hence, while hematopoietic
cells can be protected by MDR1, the selection strategy is critical for
repopulation of bone marrow with transduced cells. Preselection in culture before
transplantation significantly increased P-gp expression and chemoresistance in
vivo in mice reconstituted with transduced bone marrow cells. This study may help
to facilitate the use of MDR1 as a selectable marker in gene therapy of the
hematopoietic system. Gene Therapy (2000) 7, 348-358.
PMID- 10694817
TI - Differences among nonhuman primates in susceptibility to bone marrow progenitor
transduction with retrovirus vectors.
AB - Nonhuman primates are increasingly being used as models for pre-clinical
assessment of retrovirus vector expression and function following stem and
progenitor cell transduction. We compared the relative susceptibility of CD34+
marrow progenitors from four nonhuman primate species and humans to transduction
with amphotropic pseudotyped retrovirus vectors containing the Neo gene. The rate
of functional gene transfer was measured by colony formation under G418
selection. Marrow progenitors from pigtail macaques (Macaca nemestrina) were
transduced at about twice the rate (19.1 +/- 4.3%) as those from rhesus (11.2 +/-
3.7%) and cynomolgus (7.6 +/- 1.9%) macaques, baboons (7.8 +/- 1.8%), and humans
(9.6 +/- 1.7%). Semiquantitative RT/PCR analysis suggests this difference may be
due to elevated expression of the amphotropic receptor Pit2 in pigtailed macaque
CD34+ cells. Further, transduction rates increased an average 1.6 +/- 0.4-fold
when the culture temperature was lowered to 33 degrees C, and 2.1 +/- 0.3-fold
when the culture dishes were coated with the fibronectin fragment CH-296. The
data presented here point to important differences among nonhuman primate models
as well as transduction culture conditions, and suggest that pigtailed macaques
may be particularly useful for assessing expression and function of therapeutic
retrovirus vectors. Gene Therapy (2000) 7, 359-367.
PMID- 10694818
TI - Generation of a high titre retroviral vector for endothelial cell-specific gene
expression in vivo.
AB - Tumour growth is dependent upon a blood supply and is associated with the switch
to the angiogenic phenotype. We are developing strategies for targeting gene
expression to endothelial cells in the tumour vasculature. Recombinant
retroviruses have been generated that incorporate regulatory sequences of the
prepro-endothelin-1 (ppET1) promoter. Following reverse transcription and
integration these modifications are duplicated in the proviral 5' LTR for
transcription of the internal beta-galactosidase reporter gene. The titres and
endothelial specificity of retroviral vectors harbouring different modifications
have been analysed. In the optimal strategy, replacing the MLV enhancer with
ppET1 promoter sequences containing the GATA and AP1 elements whilst maintaining
sequences from the viral promoter resulted in endothelial cell-specific
expression of the reporter gene, and viral titres comparable to those of the
unmodified vector. A panel of endothelial and non-endothelial cells infected with
the modified virus from a high titre producer clone showed a pattern of
expression consistent with the activity of the endogenous ppET1 promoter. The
modified LTR retained specificity in vivo, in subcutaneous tumours arising from
the co-injection of tumour cells and irradiated virus producer cells. This simple
model achieves high efficiency of transduction and can be used routinely for the
screening of targeted retroviral vectors. Gene Therapy (2000) 7, 368-376.
PMID- 10694819
TI - Transduction of the contralateral ear after adenovirus-mediated cochlear gene
transfer.
AB - Cochlear gene transfer is a promising new approach for inner ear therapy.
Previous studies have demonstrated hair cell protection with cochlear gene
transfer not only in the inoculated, but also in the uninoculated ear. To
characterize the kinetics of viral spread, we investigated the extent of
transgene expression in the contralateral (uninoculated) cochlea after unilateral
adenoviral cochlear gene transfer. We used a lacZ reporter gene vector, and
demonstrated spread of the adenovirus into the cerebrospinal fluid (CSF) after
cochlear inoculation of 25 microl viral vector. Direct virus application into the
CSF resulted in transduction of both cochleae, whereas virus inoculation into the
bloodstream did not. The cochlear aqueduct was identified as the most likely
route of virus spread to the contralateral cochlea. These data enhance our
understanding of the kinetics of virus-mediated transgene expression in the inner
ear, and assist in the development of clinical applications for inner ear gene
therapy. Our results showed a functional communication between the CSF and the
perilymphatic space of the inner ear, that is not only of importance for
otological gene transfer, but also for CNS gene transfer. Gene Therapy (2000) 7,
377-383.
PMID- 10694820
TI - Bacterial DNA is implicated in the inflammatory response to delivery of DNA/DOTAP
to mouse lungs.
AB - Phase 1 clinical trials of liposome-mediated gene therapy for cystic fibrosis
have been completed and in all cases the expression level achieved has been low
and transient. Clearly, improvements in the efficiency of gene transfer are
required. It is now being recognised that delivery of high doses of DNA/liposomes
to the mouse airway epithelium can achieve reproducible evidence of transgene,
but is often associated with an unacceptable level of inflammation/ toxicity. It
has recently been shown that instillation of bacterial DNA causes inflammation in
the lower respiratory tract of rodents. The increased number and unmethylated
status of CpG motifs, particularly when present in a particular base context, was
identified as an important factor in this response. It was suggested that the
immune system recognises this molecular pattern as 'foreign' thus activating
appropriate immune responses. We have found that methylation of DNA decreases the
level of several inflammatory cytokines in lavage fluid and surprisingly has a
differential effect on expression of the plasmids pCMV CFTR-int6ab and pCMV CAT
which only differ in the actual transcription cassette. The severe lung pathology
observed did not show a corresponding decrease with methylation suggesting that
these cytokines are not the only contributors to the toxicity/inflammation
observed. Gene Therapy (2000) 7, 384-392.
PMID- 10694821
TI - An integrin-targeted non-viral vector for pulmonary gene therapy.
AB - Gene therapy offers potential for the treatment of severe respiratory diseases.
However, the vectors which are currently available have drawbacks limiting their
therapeutic application. Here we report on an integrin-targeted, non-viral gene
delivery system for pulmonary gene transfer. We demonstrate that this vector can
deliver the lacZ reporter gene to the lung, transfecting bronchial epithelium and
parenchymal cells with similar efficiency to an adenoviral vector and with
greater efficiency than a cationic liposome. In addition, vector administration
can be repeated leading to further gene expression without inducing inflammation.
The advantages of this novel gene delivery system provide considerable potential
for targeted gene therapy in vivo. Gene Therapy (2000) 7, 393-400.
PMID- 10694822
TI - Cell cycle dependence of gene transfer by lipoplex, polyplex and recombinant
adenovirus.
AB - The aim of this study was to investigate the influence of cell cycle on
transfection efficiency. Counterflow centrifugal elutriation was used which
avoids possible side-effects from chemical treatment of cells. With this method,
cell populations were fractionated by means of size and density, and fractions
corresponding to discrete cell cycle phase-specific populations were transfected
with various nonviral methods (Lipofectamine, TfpLys and TfPEI), adenovirus
enhanced transferrinfection (AVET system) and recombinant adenovirus.
Transfection efficiency was found to be strongly dependent on the cell cycle
stage at the time of transfection. Luciferase activity from cells transfected
with polycation- or lipid-based transfection systems was 30- to more than 500
fold higher when transfection was performed during S or G2 phase compared with
cells in G1 phase which have the lowest expression levels. In contrast, this
effect was not observed with recombinant adenovirus which varied only four-fold.
Our results indicate that mitotic activity enhances transfection not only by
lipoplexes but also by polyplexes, but not a viral system which has an efficient
nuclear entry machinery, suggesting that transfection close to M phase is
facilitated perhaps by nuclear membrane breakdown. Furthermore, low transfection
success into G1 cells indicates that DNA complexes deposited in G1 cells are
probably not retained long enough to take advantage of mitosis effects or that
passage of transfected cells through S phase is inhibitory. Gene Therapy (2000)
7, 401-407.
PMID- 10694823
TI - Retrovirally expressed anti-HIV ribozymes confer a selective survival advantage
on CD4+ T cells in vitro.
AB - To date, a selective advantage of cells expressing anti-HIV ribozymes has not
been shown. This study was undertaken to determine whether such a selective
advantage can be demonstrated in vitro. A retroviral vector coding for a hairpin
ribozyme targeting the HIV 5'LTR and for the low affinity nerve growth factor
receptor (LNGF-RDelta) was designed. Since we demonstrated by RT-PCR that the
amount of ribozyme transcripts was highly correlated with the level of surface
LNGF-RDelta expression, the vector was utilized to assess ribozyme expression by
flow cytometry. Transduced Hut78 and primary CD4+ T cells were purified and
subsequently mixed with unmodified cells. After HIV challenge the percentage of
ribozyme expressing cells in the cell mixture was monitored by flow cytometry.
Twenty-one days after HIV infection the proportion of ribozyme expressing CD4+ T
cells was 2.6 times higher in comparison to cells with the control vector. CD4+ T
cells with a strong ribozyme expression conferred a 7.4-fold selective advantage
at day 21 and a 11.7-fold at day 28. For Hut78 cells a selective advantage was
detected exclusively for strongly ribozyme expressing cells. As a mechanism
underlying the selective advantage an inhibition of HIV induced apoptosis was
shown. These results demonstrate that anti-HIV ribozymes are able to confer a
selective survival advantage and indicate that the protective effect is dependent
on the amount of ribozyme expression. Gene Therapy (2000) 7, 408-416.
PMID- 10694824
TI - Angiogenesis induced by hepatocyte growth factor in non-infarcted myocardium and
infarcted myocardium: up-regulation of essential transcription factor for
angiogenesis, ets.
AB - The feasibility of a novel therapeutic strategy using angiogenic growth factors
to expedite and/or augment collateral artery development has recently entered the
realm of treatment of ischemic diseases. Hepatocyte growth factor (HGF) is a
novel member of endothelium-specific growth factors whose mitogenic activity on
endothelial cells is very potent. Although it has been demonstrated that HGF is a
potential angiogenic growth factor in in vitro culture systems, there is no
direct in vivo evidence for the angiogenic activity of HGF in physiological
conditions. In this study, we hypothesized that transfection of HGF gene into
infarcted myocardium could induce angiogenesis, potentially resulting in a
beneficial response to hypoxia. Human HGF gene or control vector driven by the
SRalpha promoter was transfected into rat myocardium by the HVJ-liposome method.
Four days after in vivo transfection of human HGF gene, there was a marked
increase in human immunoreactive HGF as compared with control vector (P < 0.01).
In myocardium transfected with HGF vector, a significant increase in PCNA
positive endothelial cells was observed, while few PCNA-positive endothelial
cells were detected in both control-vector-transfected and untreated myocardium.
The number of vessels around the HGF injection sites was significantly increased
as compared with control vector or vehicle (P < 0.01). Angiogenic activity
induced by the transfection of HGF vector was also confirmed by the activation of
a transcription factor, ets, which is essential for angiogenesis. Furthermore, we
studied the pathophysiological role of HGF in a myocardial infarction model. The
concentration of endogenous HGF was significantly decreased in infarcted
myocardium. Therefore, we hypothesized that transfection of HGF gene into
infarcted myocardium could induce a beneficial response to the decreased
endogenous HGF. Indeed, transfection of human HGF into infarcted myocardium also
resulted in a significant increase in the number of vessels (P < 0. 01),
accompanied by marked induction of ets binding activity and a significant
increase in blood flow. Overall, the present results provide direct in vivo
evidence for the induction of angiogenesis by transfection of the human HGF gene
in rat non-infarcted and infarcted myocardium. The constant production of local
HGF resulting from the transgene may be considered as an innovative therapeutic
angiogenesis strategy for ischemic diseases such as myocardial infarction. Gene
Therapy (2000) 7, 417-427.
PMID- 10694825
TI - Matching host muscle and donor myoblasts for myosin heavy chain improves myoblast
transfer therapy.
AB - Intensive efforts have been made to develop an effective therapy for Duchenne
muscular dystrophy (DMD). Although myoblast transplantation has been found
capable of transiently delivering dystrophin and improving the strength of the
injected dystrophic muscle, this approach has been hindered by the immune
rejection problems as well as the poor survival and limited spread of the
injected cells. In the present study, we have investigated whether the careful
selection of donor myoblasts and host muscle for the myosin heavy chain
expression (MyHCs) plays a role in the success of myoblast transfer. Highly
purified normal myoblasts derived from the m. soleus and m. gastrocnemius white
of normal mice were transplanted into the m. soleus (containing 70% of type I
fibers) and gastrocnemius white (100% of type II fibers) of dystrophin deficient
mdx mice. At several time-points after injection (10, 20 and 30 days), the number
of dystrophin-positive fibers was monitored and compared among the different
groups. A significantly higher number and better persistence of dystrophin
positive myofibers were observed when the injected muscle and donor myoblasts
expressed a similar MyHC in comparison with myoblast transfer between host muscle
and donor myoblasts that were not matched for MyHC. These results suggest that
careful matching between the injected myoblasts and injected muscle for the MyHC
expression can improve the efficiency of myoblast-mediated gene transfer to
skeletal muscle. Gene Therapy (2000) 7, 428-437.
PMID- 10694826
TI - Beta globin gene inhibition by antisense RNA transcripts.
AB - Sickle cell disease is caused by a mutation in the beta globin gene leading to
hemoglobin S (Hb S) production. Several approaches have been explored to prevent
Hb S polymerization in red blood cells and the symptoms associated with this
disorder. To this end we tested a mammalian expression vector carrying a human
beta globin antisense cDNA (pZeobetaAS) fragment in a mouse erythroleukemia cell
line expressing the human gamma and beta globin genes. We observed a relative
reduction in beta globin mRNA levels compared with gamma mRNA levels in the
presence of pZeobetaAS. Moreover, analysis at the protein level showed an average
76% decrease in beta chains and a 517% increase in gamma chain biosynthesis. The
inhibitory effect of the antisense vector on globin expression was maintained
long term in culture. The expression vector pZeobetaAS was also transfected into
primary erythroid progenitors to test its effects on globin genes undergoing
normal developmental switching during differentiation. We observed a relative
reduction of beta globin mRNA levels compared with gamma mRNA levels. These
results support a novel role for antisense cDNA expression vectors as an
alternative gene therapy strategy to inhibit betas gene expression in sickle cell
disease. Gene Therapy (2000) 7, 438-444.
PMID- 10694827
TI - Long-term phenotypic correction of rodent hemiparkinsonism by gene therapy using
genetically modified myoblasts.
AB - Rat myoblasts were genetically modified to express tyrosine hydroxylase (TH) and
produce dopamine in culture. Implanting TH gene-transfected myoblasts into the
denervated striatum of 6-OHDA-lesioned rats significantly decreased rotational
asymmetry by 50 to approximately 60%. Improvement persisted for up to 13 months.
Genetically modified cells could survive and express transgene in the striatum as
demonstrated by RT-PCR and immunohistochemical stain-ing. The dopamine content in
the striatum tissue of the gene therapy group recovered to 49% of the normal
level and was 25-fold higher than that of a control group receiving parental
cells. Neither tumor formation nor immunorejection was observed in this study.
These results show that myoblasts may be useful as gene carriers for ex vivo gene
therapy in the CNS. Gene Therapy (2000) 7, 445-449.
PMID- 10694828
TI - What has happened to malignant hypertension? A disease no longer vanishing.
PMID- 10694829
TI - Does Chinese ethnicity affect the pharmacokinetics and pharmacodynamics of
angiotensin-converting enzyme inhibitors?
AB - Information from clinical and pharmacokinetic studies of angiotensin-converting
enzyme inhibitors (ACEIs) has come from subjects who are mostly male and
Caucasian, but the use of ACEIs extends to populations worldwide. Significant
differences between Chinese in general and male Caucasians have been demonstrated
in the pharmacokinetics/dynamics of other drug classes that could have
implications for the use of ACEIs in the Chinese population. These include:
significant Chinese/Caucasian genetic variation in the renin-angiotensin system
based on an insertion/deletion (O/D) polymorphism of the ACE gene; the genetic
determination of plasma ACE activity in the Chinese population; and genetic
factors involving the disease substrate which may also influence the response to
treatment. Oral and IV pharmacokinetic data from various studies of Chinese and
Caucasian subjects are available for cilazapril, fosinopril, and perindopril, and
pharmacodynamic data are available for eight different ACEIs. Based on these
data, there are few differences among the pharmacokinetics of ACEIs between
Chinese and Caucasians. Most ACEIs showed good blood pressure lowering efficacy
in Chinese (benazepril, enalapril, fosinopril and spirapril), with perhaps less
blood pressure lowering with cilazapril or a relatively shorter-term effect with
cilazapril or perindopril compared to Caucasions. Chinese experience more cough
from ACEIs (captopril and enalapril) than Caucasians. Data suggest that
fosinopril may not induce cough in as many subjects as other ACEIs, and this
seems to be true of Chinese as well. The mechanism, currently unknown, could
involve fosinopril's dual elimination pathway (hepatic and renal).
Pharmacokinetic data also support the use of fosinopril in congestive heart
failure where elimination pathways may be impaired. In conclusion, ethnic
differences between Chinese and Caucasians with respect to ACE and AGT gene
polymorphism, which might be expected to differentially affect the action of
ACEIs in these two ethnic groups, do not, in fact, have such an effect. Rather,
differences among the ACEIs appear to be more important. Journal of Human
Hypertension (2000) 14, 163-170.
PMID- 10694830
TI - Factors influencing the development of malignant hypertension in Nigeria.
AB - Hypertension prevalence rates remain comparatively low in Nigeria, although the
associated morbidity and mortality including that due to malignant hypertension
(MHT) is considerable. To determine the factors that may be associated with the
development of MHT we compared 74 patients with essential MHT (age 48 +/- 9
years, 59 male, blood pressure (BP) 234 +/- 31/140 +/- 17 mm Hg) with 74, age,
gender and BP-matched patients with essential benign hypertension (BHT) (49 +/- 8
years, 60 male, 227 +/- 26/136 +/- 15 mm Hg). Body mass index was higher in the
BHT [corrected] group by 1.3 (95% Cl: 0.5 to 2.1, P < 0.01). In the subset (25
MHT, 43 BHT) in whom hypertension had been diagnosed before presentation,
duration of hypertension was shorter (P < 0.05) in the MHT group. Patients with
MHT, were more likely to have been receiving inadequate therapy in the months
before (OR 2.7, 95% Cl: 1.4 to 5.4), showed a decreasing proportion with
increasing socio-economic class (chi2 = 5.79, P < 0.02) and had been exposed to a
greater degree of stress (OR 3.5, 95% Cl: 1.7 to 7. 1). Smoking (OR 1.1, 0.6 to
2.3), alcohol use (OR 0.9, 0.5 to 1.8) and contraceptive pill use (OR 0.9, 0.1 to
8.6) did not impart excess risk. MHT is associated with the underprivileged and
measures aimed at raising the general awareness and the socio-economic level of
the people are expected to produce a decline in the incidence of MHT. Journal of
Human Hypertension (2000) 14, 171-174.
PMID- 10694831
TI - Induction of insulin resistance by beta-blockade but not ACE-inhibition: long
term treatment with atenolol or trandolapril.
AB - The effects on glucose metabolism by the beta-blocker atenolol and the
angiotensin-converting enzyme (ACE)-inhibitor trandolapril were investigated in a
randomised double-blind parallel group study of patients with primary
hypertension. Twenty-six patients were treated with 50-100 mg atenolol and 27
patients with 2-4 mg trandolapril o.d. Intravenous glucose tolerance tests,
euglycaemic hyperinsulinaemic clamps and serum lipid measurements were performed
after 8 and 48 weeks of active treatment. After 48 weeks insulin sensitivity was
reduced by 23% by atenolol while it remained unchanged during trandolapril
treatment (+0.5%, P = 0.0010 for difference between treatments, ANCOVA). The
effect on triglycerides (+22% vs -8.5%) and high-density lipoprotein cholesterol
(-13% vs +0.7%) also differed significantly between atenolol and trandolapril.
Results after 8 weeks were similar. Glucose tolerance was not affected by either
drug. Atenolol reduced diastolic blood pressure (DBP) better than trandolapril (
15.3 mm Hg vs -6.6 mm Hg for supine DBP after 48 weeks, P = 0.012). The
difference in effect on insulin sensitivity between the drugs corresponded to 25%
of the baseline values of insulin sensitivity, and persisted over 48 weeks of
treatment. The choice of antihypertensive treatment could influence the risk of
diabetes associated with treated hypertension. Journal of Human Hypertension
(2000) 14, 175-180.
PMID- 10694832
TI - Left ventricular adaptation to hypertension and plasma renin activity.
AB - Chronic pressure and volume overload result in morphologically and functionally
distinct forms of myocardial hypertrophy. In essential hypertension, the
respective effect of these factors on the morphology of the left ventricle
remains unknown. In the present study, we hypothesised that activity of the renin
angiotensin system (assessed by plasma renin activity) may be associated to the
variability of the left ventricular adaptation to essential hypertension. To
assess this relation, we categorised by echocardiography 333 never-treated
hypertensive patients, according to values of left ventricular mass and relative
wall thickness. Higher systolic and pulse arterial pressure was strongly
associated with concentric left ventricular hypertrophy (27% of hypertensives).
When compared to the normal left ventricle group, patients with eccentric left
ventricular hypertrophy (15% of hypertensives) had a high cardiac index (5 +/- 1
vs 4 +/- 0.8 L/min/m2; P = 0.0001), a lower basal plasma renin activity (0.81 +/-
0.63 vs 1.45 +/- 1.3 ng/ml/h; P = 0.02) and similar mean values of left
ventricular performance and glomerular filtration rate. A tendency for depressed
myocardial contractility assessed by the midwall shortening/end-systolic stress
was associated with concentric left ventricular remodelling and hypertrophy when
compared to hypertensive with a normal left ventricle. In conclusion, at the
early phase of essential hypertension, in patients without renal dysfunction,
each anatomic pattern of cardiac adaptation to hypertension was associated with a
distinct profile of haemodynamics, myocardial function and activity of the renin
angiotensin system. Journal of Human Hypertension (2000) 14, 181-188.
PMID- 10694833
TI - The effects of acute and chronic dihydropyridine calcium antagonist therapy on
baroreflex sensitivity: a re-analysis using the sequence method.
AB - The objective of this study was to examine the effects of dihydropyridine calcium
antagonist therapy on 24-h baroreflex sensitivity. Twenty-three patients with
moderate essential hypertension were studied before and during acute (10
patients) and chronic (21 patients) treatment with a dihydropyridine calcium
antagonist (nifedipine, nicardipine or felodipine) as monotherapy in a dose
titrated to produce a fall in mean cuff pressure of at least 10%. Twenty-four
hour unrestricted ambulatory intra-arterial blood pressure (IABP) and heart rate
(R-R interval) were monitored. Baroreflex sensitivity (BRS) was assessed
throughout the 24-h period by off-line computer analysis of spontaneous
variations in IABP and R-R interval. During acute first dose treatment with a
calcium antagonist there was a significant fall in blood pressure (BP), increase
in heart rate and reduction in BRS. With chronic therapy (6-16 weeks) there was a
continued reduction in mean BP of 11% (P < 0.001), but heart rate had returned to
control levels and BRS was significantly increased over the 24 h by 14% (P <
0.01). The increase in BRS was evident during both the waking and sleeping
periods, but the greatest increase was during sleep (awake 12% P = 0. 02, asleep
28% P = 0.003). In conclusion, although dihydropyridine calcium antagonists
acutely cause a reflex tachycardia associated with a reduced BRS, there is no
such effect with chronic therapy. BRS was significantly increased after chronic
treatment, with exaggeration of the diurnal pattern. Journal of Human
Hypertension (2000) 14, 189-194.
PMID- 10694834
TI - Role of erythropoietin in cortisol-induced hypertension.
AB - The mechanism of cortisol-induced hypertension remains unknown. We investigated a
possible role of erythropoietin (EPO) as a mediator of hypertension in healthy
male subjects treated with cortisol. In Study 1, blood pressure (BP) and serum
EPO concentrations were measured on alternate days in nine subjects treated with
80 mg of cortisol per day for 5 days. In Study 2 the same parameters were
measured in eight subjects randomised to cortisol (80 mg/day) or placebo and 10
subjects randomised to cortisol (200 mg/day) or placebo for 5 days. In Study 1,
cortisol caused a significant increase in systolic BP (SBP) (115 +/- 2 vs 126 +/-
2 mm Hg, control vs day 5, P < 0.001) and serum EPO concentrations (14.5 +/- 2.7
vs 24.3 +/- 2.7 mU/mL, P < 0.001). In Study 2 both doses of cortisol increased
SBP (118 +/- 2 vs 113 +/- 2 mm Hg, 80 mg cortisol vs placebo, P < 0.05 and 129 +/
3 vs 113 +/- 2 mm Hg, 200 mg cortisol vs placebo, P < 0.001). Serum EPO
concentrations were significantly increased at 200 mg cortisol (25.2 +/- 11.9 vs
15.9 +/- 3.5 mU/mL, P < 0.01) but not 80 mg cortisol (21.3 +/- 2.9 vs 14.9 +/-
3.1 mU/mL). In the 200 mg group there was a positive correlation between the
change in SBP and the change in serum EPO concentration (r2 = 0.43, P < 0.05).
These results point to a possible role for EPO as the mediator of cortisol
induced hypertension. Journal of Human Hypertension (2000) 14, 195-198.
PMID- 10694835
TI - The 460Trp polymorphism of the human alpha-adducin gene is not associated with
isolated systolic hypertension in elderly Australian Caucasians.
AB - The study was undertaken to determine whether polymorphic variants of the alpha
adducin gene are associated with isolated systolic hypertension (ISH) in elderly
Australian Caucasians. Participants were classified with ISH (n = 87, systolic
blood pressure (SBP) > or =160 mm Hg and diastolic blood pressure (DBP) < or =90
mm Hg) or normotension (n = 124, SBP <140 mm Hg and DBP <90 mm Hg with no family
history of hypertension). To collect demographic data, a structured questionnaire
was used. DNA was extracted using standard techniques from 211 subjects (age
range 61-89, mean age 73 +/- 6.6 years, male: female ratio 1.1:1). Genotypes
(gly/gly, trp/gly and trp/trp) were assigned in triplicate by polymerase chain
reaction (PCR) followed by electrophoresis, using a laser scanning
electrophoresis unit. The validity of the method was confirmed by sequencing.
Frequencies of allele distribution in ISH or control groups were determined by
Chi-square tests and a stepwise logistic regression model, which controlled for
potential confounders, was used to examine any independent association between
alpha-adducin genotypes or alleles with ISH and normotensive controls. Mean BP
(+/- s.d.) was: 170/79.8 +/- 14.9/8.3 mm Hg and 122.1/ 73.4 +/- 8. 8/7.6 mm Hg in
the ISH and normotension groups respectively. The unadjusted allele and genotypes
frequencies were not significantly different in the ISH patients groups compared
with normotensive controls (chi2 = 1.59, P = 0.45 and chi2 = 1.23, P = 0.28
respectively). In this elderly cohort, after adjustment for potential
confounders, no statistically significant association was found between alpha
adducin genotype and SBP (P = 0.65 for homozygotes, P = 0.59, for heterozygotes),
DBP (P = 0.49 homozygotes, for heterozygotes P = 0.45) pulse pressure (P = 0.87
homozygotes, for heterozygotes P = 0.95) diagnosis of ISH (P = 0.72 for
homozygotes, P = 0.68 for heterozygotes). However age and renal disease predicted
the diagnosis of ISH (P = 0.001, P = 0.459, respectively), a large pulse pressure
(P < 0.0001, P = 0.033, respectively) and a higher SBP (P < 0.0001, P = 0.025,
respectively) in this large cohort of elderly Australian Caucasian volunteers.
Journal of Human Hypertension (2000) 14, 199-203.
PMID- 10694836
TI - Bisoprolol and nifedipine retard in elderly hypertensive patients: effect on
quality of life.
AB - Subjects over the age 60 with sustained sitting diastolic pressures of 95-115 mm
Hg were randomised to a regime based on bisoprolol (n = 368) or nifedipine retard
(n = 379) for 24 weeks. The goal diastolic pressure was < or =90 mm Hg and to
achieve this, double-blind medication could be doubled (5/10 mg bisoprolol, 40/80
mg nifedipine retard) or hydrochlorothiazide 25 mg (unblinded) could be added to
the higher dose. In an intention-to-treat analysis, 309 subjects in both the
bisoprolol and nifedipine retard treated group provided at least a baseline and a
second quality of life assessment (82%). An excess of symptoms was observed in
the nifedipine group for oedema of the legs, nocturia, constipation, racing heart
and heart thumping. Fewer patients reported wheeze in the nifedipine group. For
quality of life, there were no statistically significant differences between the
two groups after 8 weeks. However, when analysing the results of the last
available assessment (usually at 24 weeks) there were significant (P < 0.05)
improvements in tension/anxiety, anger/ hostility, vigour/activity, and
confusion/bewilderment, assessed by the Profile of Mood States (POMS) in patients
receiving bisoprolol in comparison to those receiving nifedipine retard. The
Sickness Impact Profile and objective tests of cognitive function did not differ
statistically between the two groups. Quality of life was maintained at a good
level on both treatments with advantages for bisoprolol in certain areas. Journal
of Human Hypertension (2000) 14, 205-212.
PMID- 10694837
TI - The association of RBC sodium-lithium countertransport (Vmax) with left
ventricular mass in African American women.
AB - In Caucasian hypertensives and diabetics, increased RBC sodium-lithium
countertransporter activity (SLC) is a marker for end-organ complications of
vascular disease. A subgroup of African Americans with high Vmax for SLC show
strong correlations with dyslipidaemia, insulin resistance, microalbuminuria and
higher blood pressure. The purpose of our study was to determine if Vmax in
premenopausal African American women correlates with left ventricular mass (LVM)
before the onset of clinically diagnosed hypertension. Non-diabetic African
American women (n = 35, mean age 31 years) were evaluated for cardiovascular
disease risk factors, including anthropometric and blood pressure measurements,
oral glucose tolerance test (OGTT), and euglycaemic hyperinsulinaemic clamp for
insulin sensitivity. Fasting blood specimens were assayed for SLC activity (Vmax)
and lipids. Cardiac structure was determined by 2-D echocardiography. LVM was
calculated by the cube root formula and adjusted for height (LVM index). Vmax
correlated significantly with average systolic blood pressure (r = 0.45, P =
0.007), diastolic blood pressure (r = 0.48, P = 0.004), mean blood pressure (r =
0.48, P = 0.003) and LVM index (r = 0.40, P = 0.02). Vmax was also associated
with fasting insulin (r = 0.39, P = 0.01), the sum of insulin (r = 0.52, P =
0.002), and insulin sensitivity adjusted for fat-free mass (r = -0.55, P =
0.001). There was no statistically significant relationship between Vmax and body
mass or lipids. Vmax for SLC correlates with cardiac structure in premenopausal
African American women. Vmax is also associated with insulin sensitivity and
insulin resistance in this non-diabetic sample. SLC activity may be useful in
identifying a subgroup of young African American women with left ventricular
hypertrophy and insulin resistance before the onset of clinically diagnosed
hypertension and diabetes. Journal of Human Hypertension (2000) 14, 213-219.
PMID- 10694838
TI - High life. A history of high-altitude physiology and medicine
PMID- 10694839
TI - Chemokines and chemokine receptors in the pathogenesis of multiple sclerosis.
AB - In recent years we have seen growing evidence for the role of chemokines in the
pathogenesis of several infectious and non-infectious inflammatory CNS disease
states, including Multiple Sclerosis (MS) and its animal model, experimental
allergic encephalomyelitis (EAE). An increase in proinflammatory chemokines has
been associated with demyelinating lesions and clinical neurological dysfunction
in patients with MS; these chemokines could be potential targets for MS therapy.
Besides a clearly defined role in mediating leukocyte migration, these and other
chemokines may act as immunoregulatory molecules in the driving to Th1/Th2
responses, switch of cytokine profiles, and the induction of tolerance. Since
chemokine receptors have now been identified on macrophages, microglia,
astrocytes, and endothelial cells as well as neurons in the CNS,
chemokine/receptor interactions may mediate functional responses in a variety of
CNS cell types during the course of inflammatory disease states. Therefore,
clarification of the roles of chemokines and their receptors in the pathogenesis
of EAE and MS will be useful in establishing immunotherapeutic strategies for
these neurological autoimmune disorders.
PMID- 10694840
TI - Evaluation of the apo-1/Fas promoter mva I polymorphism in multiple sclerosis.
AB - The pathogenesis of multiple sclerosis is under strong genetic control involving
several or more genes each of modest effect. Whilst the mechanisms underlying the
pathogenesis of MS remain unknown, it has been hypothesised that either decreased
apoptosis of autoreactive T cells in the CNS, or increased apoptosis of
oligodendrocytes may play an important role. The Apo-1/Fas antigen (CD95), the
gene for which is located in a chromosomal region showing linkage in MS genome
screens, is a critical inducer of apoptosis and studies have shown aberrant
expression of this molecule in MS, correlating with a decrease in T cell
apoptosis or increase in CNS tissue damage. This study investigated an Mva I
polymorphism in the Apo-1/Fas promoter region in a group of 124 Australian
patients with relapsing-remitting MS and in 183 normal controls. Whilst there
were increases in the Mva I*2 allele in MS individuals overall (59% vs 52%, P not
corrected=0.08), and in HLA-DRB1*1501 negative MS patients (62% vs 55%), these
were not significantly different from controls. Interactions were investigated
between the Mva I alleles and T cell receptor beta chain variable region (TCRBV)
germline polymorphisms, with a trend in MS individuals towards a decrease of the
Mva I*1 allele when combined with the TCRBV3S1*2 allele (Relative Risk=0.25,
P=0.067), and with the TCRBV8S1*1 allele (Relative Risk=0.44, P=0.12). Overall,
the findings of this study indicate a possible effect of the Apo-1/Fas promoter
Mva I polymorphism in MS susceptibility, which needs to be confirmed in further
studies. Multiple Sclerosis (2000) 6 14 - 18
PMID- 10694841
TI - Interferon gamma production in blood lymphocytes correlates with disability score
in multiple sclerosis patients.
AB - The proinflammatory cytokine interferon gamma (IFG) is elevated in body fluids of
multiple sclerosis patients but its variation range is broad. The reason for this
wide scatter of IFG production is not yet known. We looked for the relation
between clinical parameters such as disability, exacerbation frequency, disease
duration, course of the disease and IFG producing blood lymphocytes. Forty-one
consecutive, clinically stable multiple sclerosis patients with primary relapsing
course of the disease and without immunomodulatory or immunosuppressive treatment
in the last 3 months were investigated for IFG in blood lymphocytes by flow
cytometry. A significant positive correlation between IFG production and
disability (r = 0.45, P<0.01, Spearman's rho coefficient) was found.
Pathophysiological implications and therapeutical relevance of this unexpected
finding are discussed.
PMID- 10694842
TI - Positive association between blood brain barrier disruption and osmotically
induced demyelination.
AB - Rapid correction of chronic hyponatremia can cause osmotic brain demyelination in
animals and humans. Why demyelination develops is unknown, but blood brain
barrier disruption might expose oligodendrocytes to substances normally excluded
from the brain. To test this hypothesis, chronic hyponatremia was induced and
corrected using a new, reproducible rat model for producing osmotic brain
demyelination. Blood brain barrier integrity was assessed by NMR imaging at
either 3, 16 or 24 h during the first day of correction. Demyelination was
determined histopathologically 5 - 6 days later. Of 96 rats studied,
demyelination developed 5 - 6 days later in 37 rats, 89% of whom showed barrier
disruption. In the 59 rats who did not develop demyelination, 45 (76%) had no
barrier disruption. Thus, blood-brain barrier disruption during the first 24 h of
correction was associated with a 70% risk of developing demyelination. By
contrast, the risk of developing subsequent demyelination was only 8% when the
barrier was intact. This strong association between barrier disruption and
subsequent demyelination provides new insights into the role of blood brain
barrier function in demyelinative disorders such as the osmotic demyelination
syndrome and by extension to other demyelinative disorders such as multiple
sclerosis.
PMID- 10694843
TI - Polymorphisms of apolipoprotein E; outcome and susceptibility in multiple
sclerosis.
AB - Allelic variants of the apolipoprotein E (APOE) gene influence the course of
several neurological diseases. In multiple sclerosis the concentration of APOE in
cerebrospinal fluid and its intrathecal synthesis is reduced. Specific isoforms
of APOE may also be important and it has been suggested that possession of the
epsilon4 allele may be associated with a more aggressive disease process. These
data prompted us to re-examine, in a large group of patients with multiple
sclerosis, the proposal that allelism in the apolipoprotein gene influences
disease course. Genotypes were determined in a well-defined group of 370
unrelated Caucasians with clinically definite multiple sclerosis and in 159
healthy controls. Age at onset, sex, disease duration, disease subtype were
recorded. Disability was measured using the Kurtzke expanded disability status
score in patients with a disease duration of 10 years or greater. There was no
significant difference in APOE allele or genotype frequencies between patients
and controls, between disease subtypes or between genders. APOE genotype did not
significantly influence age of onset, and no significant relationship between
genotype, allele frequency and disease severity was found. This study suggests
that individual APOE alleles or genotypes do not determine disease susceptibility
or the clinical course of multiple sclerosis.
PMID- 10694844
TI - Macrophages: their myelinotrophic or neurotoxic actions depend upon tissue
oxidative stress.
AB - There are still questions regarding whether macrophages found in MS lesions are
agents of recovery or of destruction. To address this, we examined in aggregate
cultures prepared from dissociated embryonic spinal cord tissue, with or without
addition of exogenous macrophages, the effect of menadione-induced oxidative
stress. Similar to findings of other laboratories, we observed that in the
absence of oxidative stress macrophage enrichment promoted myelinogenesis. In
macrophage-poor cultures, menadione at 5 microM had very little effect upon the
status of the aggregate cultures; however, increasing this to 10 and 20 microM
did result in some damage to axons and myelin. By contrast, in macrophage
enriched cultures, menadione at a concentration as little as 5 microM caused the
complete destruction of the aggregates. We suggest that in neural tissues that
have sufficiently high macrophage numbers, oxidative stress results in a positive
inflammatory feedback loop that results in massive tissue destruction. We further
suggest that what we see in macrophage-enriched aggregates subjected to oxidative
stress may represent what happens in the Marburg-type of MS lesion.
PMID- 10694845
TI - Contrast-enhanced magnetic resonance activity in relapsing remitting multiple
sclerosis patients: a short term natural history study.
AB - Magnetic resonance imaging (MRI) has been used to study the history of multiple
sclerosis (MS). We analyze the relationship between MRI activity in the first
scan compared to the subsequent five scans, and we evaluate whether a shorter
observation period of 3 months may predict the subsequent 3 months. Monthly
enhanced MRI was performed in 103 relapsing remitting (RR) MS patients for 6
months. Thirty-five per cent of patients had an inactive scan on the initial
examination. More than 80% of them developed MRI activity during the following 5
months. Eighteen per cent of patients had three consecutive inactive scans; 65%
of them had at least one active scan on the subsequent 3 monthly MRI's. The
relationship between the first scan and all subsequent scans demonstrates a clear
weakening over time. Eighty-two per cent of patients had at least one active scan
during the initial 3 consecutive months, the chance of becoming inactive
decreased from 23% to 0% over the subsequent 3 months, according with the mean
number of enhancing lesions during the first 3 months. These results suggest that
neither a single scan nor a short baseline of 3 months may adequately describe
the natural history of disease in an individual RRMS patient.
PMID- 10694846
TI - Cortical deficits in multiple sclerosis on the basis of subcortical lesions.
AB - Patients suffering from multiple sclerosis have a high frequency of cognitive
deficits usually attributable to demyelination and axonal loss in the subcortical
white matter. Neurologic abnormalities referable to cortical function are
uncommon but have been described. The present study describes three patients with
clinically definite MS with deficits in cognitive function referable to cortical
location. Two of the patients underwent positron emission tomography and showed
profound cortical hypometabolism adjacent to subcortical white matter lesions
seen on MRI. This paper points out that neurologic deficits referable to cortical
sites may be caused by subcortical white matter lesions and that cognitive
dysfunction in patients with MS may progress rapidly in the absence of motoria
deficits or other evidence of clinical deterioration. Multiple Sclerosis (2000) 6
50 - 55
PMID- 10694847
TI - Drop in relapse rate of MS by combination therapy of three different
phosphodiesterase inhibitors.
AB - Phosphodiesterase inhibitors (PDEIs), when used in combination, synergistically
suppress TNFalpha production by various cells and also suppress experimental
demyelination at very low concentrations. We conducted a pilot study to determine
whether the combination of three PDEIs suppresses the relapse of MS at the usual
therapeutic doses. Of the 12 relapsing remitting MS, the mean relapse rate/year
dropped remarkably (from 3.08+/-3.32 to 0.92+/-1.86) after PDEI treatment. Seven
out of 12 (58.3%) were relapse-free in the follow up period (499+/-142 days). The
combination of three PDEIs can be safe and useful strategy for the future
treatment of MS. - 58
PMID- 10694874
TI - Clusterin is a secreted mammalian chaperone.
PMID- 10694875
TI - Mapping chromosomal proteins in vivo by formaldehyde-crosslinked-chromatin
immunoprecipitation.
AB - Gene regulation is a complex process. Numerous factors appear to be required for
the accurate temporal and spatial regulation of each gene. Often these factors
are assembled into multiprotein complexes, contributing to specific gene
regulation events. Understanding how all these factors are organized in the
chromosome and how their function is regulated in vivo is a challenging task. One
of the most useful techniques for studying this level of gene regulation is the
in vivo fixation by formaldehyde crosslinking of proteins to proteins and
proteins to DNA, followed by immunoprecipitation of the fixed material.
PMID- 10694876
TI - Dennis chapman (1927-1999)
PMID- 10694877
TI - Exonic splicing enhancers: mechanism of action, diversity and role in human
genetic diseases.
AB - Exonic splicing enhancers (ESEs) are discrete sequences within exons that promote
both constitutive and regulated splicing. The precise mechanism by which ESEs
facilitate the assembly of splicing complexes has been controversial. However,
recent studies have provided insights into this question and have led to a new
model for ESE function. Other recent work has suggested that ESEs are comprised
of diverse sequences and occur frequently within exons. Ominously, these latter
studies predict that many human genetic diseases linked to mutations within exons
might be caused by the inactivation of ESEs.
PMID- 10694878
TI - A superfamily of membrane-bound O-acyltransferases with implications for wnt
signaling.
PMID- 10694879
TI - SAP - a putative DNA-binding motif involved in chromosomal organization.
PMID- 10694880
TI - Enzymes on the Web
PMID- 10694881
TI - The dynamin family of mechanoenzymes: pinching in new places.
AB - The large GTPase dynamin is a mechanoenzyme that mediates the liberation of
nascent clathrin-coated pits from the plasma membrane during endocytosis.
Recently, this enzyme has been demonstrated to comprise an extensive family of
related proteins that have been implicated in a large variety of vesicle
trafficking events during endocytosis, secretion and even maintenance of
mitochondrial form. The potential contributions by the dynamin family to these
diverse but related functions are discussed.
PMID- 10694882
TI - Histone deacetylases: silencers for hire.
AB - Over the past few years, the long-standing idea that covalent modification of
chromatin can play a role in determining states of gene activity has been
confirmed. Eukaryotic genes can be silenced by deacetylation of acetyl-lysine
moieties in the N-terminal tails of histones. Recent work links histone
deacetylases with an increasing number of repressors, suggesting that
deacetylation might be a rather pervasive feature of transcriptional repression
systems.
PMID- 10694883
TI - Flavoenzymes: diverse catalysts with recurrent features.
AB - Many biochemical processes exploit the extraordinary versatility of flavoenzymes
and their flavin cofactors. Flavoproteins are now known to have a variety of
folding topologies but a careful examination of their structures suggests that
there are recurrent features in their catalytic apparatus. The flavoenzymes that
catalyse dehydrogenation reactions share a few invariant features in the hydrogen
bond interactions between their protein and flavin constituents. Similarly, the
positioning of the reactive part of the substrate with respect to the cofactor is
generally conserved. Modulation of substrate and cofactor reactivity and exact
positioning of the substrate are key elements in the mode of action of these
enzymes.
PMID- 10694884
TI - Function of the ubiquitin-proteasome pathway in auxin response.
AB - The plant hormone auxin regulates many aspects of growth and development. Despite
the importance of this hormone, the molecular basis for auxin action has remained
elusive. Recent advances using molecular genetics in Arabidopsis have begun to
elucidate the mechanisms involved in auxin signaling. These results suggest that
protein degradation by the ubiquitin pathway has a central role in auxin
response.
PMID- 10694885
TI - A novel FeS cluster in Fe-only hydrogenases.
AB - Many microorganisms can use molecular hydrogen as a source of electrons or
generate it by reducing protons. These reactions are catalysed by metalloenzymes
of two types: NiFe and Fe-only hydrogenases. Here, we review recent structural
results concerning the latter, putting special emphasis on the characteristics of
the active site.
PMID- 10694887
TI - NPS@: network protein sequence analysis.
PMID- 10694886
TI - Eukaryotic DNA polymerases, a growing family.
AB - In eukaryotic cells, DNA polymerases are required to maintain the integrity of
the genome during processes, such as DNA replication, various DNA repair events,
translesion DNA synthesis, DNA recombination, and also in regulatory events, such
as cell cycle control and DNA damage checkpoint function. In the last two years,
the number of known DNA polymerases has increased to at least nine (called alpha,
beta, gamma, delta, epsilon, zeta, eta, t and iota), and yeast Saccharomyces
cerevisiae contains REV1 deoxycytidyl transferase.
PMID- 10694888
TI - Macromolecular interactions: tracing the roots.
PMID- 10694889
TI - A Pseudomonas aeruginosa strain isolated from a contact lens-induced acute red
eye (CLARE) is protease-deficient.
AB - PURPOSE: Pseudomonas aeruginosa proteases are thought to be important virulence
factors in the pathogenesis of corneal disease. This study examined protease
production from two strains of P. aeruginosa responsible for two very distinct
clinical diseases: strain Paer1, isolated from a Contact Lens-induced Acute Red
Eye (CLARE), and strain KEI 1025, isolated from a corneal ulcer. Strains were
compared to a laboratory strain (ATCC 19660) known to produce severe keratitis in
experimentally infected mice for protease production and for ocular virulence.
METHODS: Protease production was examined with colorimetric assays, gelatin
zymography and western blots. Elastase A activity was quantitated with a
staphylolytic assay. Ocular virulence was examined using a mouse scratch model of
keratitis. RESULTS: In contrast to strains KEI 1025 or ATCC 19660, Paer1 was
unable to produce enzymatically active elastase A, elastase, and protease IV. All
three strains produced active alkaline protease. Strains KEI 1025 and ATCC 19660
produced a fulminant keratitis in mice whereas Paer1 produced a mild transient
infection. Restoration of elastase activity in Paer1 via genetic complementation
did not result in a virulent phenotype. Co-infection of mouse eyes with strains
Paer1 and ATCC 19660 resulted in the eventual loss of Paer1 from corneal tissue.
CONCLUSIONS: These studies suggest that P. aeruginosa elastase A and/or protease
IV, but not alkaline protease or elastase, contribute to the ocular virulence of
this organism.
PMID- 10694890
TI - Growth regulation of bovine retinal pericytes by transforming growth factor-beta2
and plasmin.
AB - PURPOSE: Transforming growth factor -beta2 (TGF-beta2) is a predominant isoform
of TGF-betas in the eye and plasmin is a peptidase with many functions. To better
understand the pathogenesis of retinal microcirculation disorders, the effects of
TGF-beta2 and plasmin on cultured bovine retinal pericytes were investigated.
METHODS: Exogenous TGF-beta2 or plasmin was added to some cultures, DNA synthesis
during cell cycle progression was investigated using [(3)H]thymidine
incorporation. Anti-TGF-beta2 antibody was added to neutralize the effects of TGF
beta2. TGF-beta2 in the culture medium was measured using enzyme-linked
immunosorbent assay (ELISA). RESULTS: Exogenous TGF-beta2 (10 pg to 100 ng/mL)
suppressed DNA synthesis. Pericytes produced TGF-beta2. Anti-TGF-beta2 antibody
neutralized TGF-beta2 and accelerated DNA synthesis, which shows that pericytes
regulate their own cell cycle by action of the autocrine and/or paracrine system
of TGF-beta2. Plasmin (0.2 to 0.5 U/mL) accelerated DNA synthesis in a dose
dependent manner, while addition of aprotinin, a protease inhibitor, counteracted
this effect of plasmin. The concentration of TGF-beta2 in the culture medium
decreased with the addition of plasmin. Simultaneous addition of both plasmin and
anti-TGF-beta2 antibody accelerated DNA synthesis. High and low glucose
concentrations of the culture medium did not affect DNA synthesis. CONCLUSIONS:
Our results suggest that TGF-beta2 and plasmin respectively decrease and increase
DNA synthesis. In a retinal microcirculation disorder, they may play competitive
roles in the cell cycle of pericytes.
PMID- 10694891
TI - Growth factor mRNA and protein in preserved human amniotic membrane.
AB - PURPOSE: To investigate the expression of growth factor mRNA and the level of
growth factor protein in preserved human amniotic membrane (AM). METHODS: RT-PCR
was used to examine the expression of mRNA for eight growth factors (EGF, TGF
alpha, KGF, HGF, bFGF, TGF-beta1, -beta2, -beta3) and two growth factor receptors
(KGFR and HGFR) in human AM preserved at -80 degrees C for one month. In
addition, ELISAs were used to measure the protein concentrations of seven growth
factors (EGF, TGF-alpha, KGF, HGF, bFGF, TGF-beta1, -beta2) in preserved human
corneas and in AM both with and without amniotic epithelium. RESULTS: RT-PCR
revealed that human AM expresses mRNA for EGF, TGF-alpha, KGF, HGF, bFGF, TGF
beta1, -beta2, -beta3, KGFR and HGFR, while ELISAs showed that it contains EGF,
TGF-alpha, KGF, HGF, bFGF, TGF-beta1, -beta2. AM without amniotic epithelium also
contains all seven growth factors examined, however, in this tissue the protein
levels of EGF, KGF, HGF and bFGF were found to be significantly lower than in
native AM. CONCLUSIONS: Preserved human AM expresses mRNAs for a number of growth
factors and contains several growth factor proteins that might benefit
epithelialization after AM transplantation. High levels of EGF, KGF, HGF and bFGF
in AM with amniotic epithelium as compared to AM without amniotic epithelium
suggest an epithelial origin for these growth factors. We feel that EGF, KGF and
HGF in particular might play important roles in ocular surface wound healing
after AM transplantation.
PMID- 10694892
TI - Lacrimal fluid peroxidase activity during the menstrual cycle.
AB - PURPOSE: The aim of this work was to investigate peroxidase activity in human
tears during the various phases of the menstrual cycle. For comparative purposes
saliva was also examined. METHODS: Tear fluids and saliva from 10 healthy
volunteers 23-41 years of age (mean: 28.2 years), with regular menstrual cycles
were sampled for the duration of at least two complete cycles. Menstrual cycles
and ovulation periods were evaluated by measuring morning body temperature and
hormone levels in plasma and urine. Unstimulated tears and unstimulated saliva
were collected in the morning every two days. Peroxidase activity was monitored
according to the 5,5'-dithiobis, 2-nitrobenzoic acid thiocyanate (Nbs-SCN) method
and the protein content was determined by the Bradford method. RESULTS:
Peroxidase activity in tears, expressed as U/mL, was significantly (p <.05)
higher during the preovulatory and luteal phases with respect to the menses,
whilst total protein content remained almost unchanged throughout all phases. A
positive correlation was found between lacrimal fluid peroxidase activity and
17beta-estradiol plasma levels (p <.001). Salivary peroxidase activity did not
show such estrogen-related changes. CONCLUSIONS: Our findings report cyclic
variations in peroxidase activity in human tears during the menstrual cycle. Such
cycling seems to reflect variations of 17 beta-estradiol plasma levels. These
results suggest that a regulation of lacrimal fluid peroxidase by 17 beta
estradiol could be one possible cause for the female gender predilection in some
ocular diseases, such as keratoconjunctivitis sicca.
PMID- 10694893
TI - Lp85 calpain is an enzymatically active rodent-specific isozyme of lens Lp82.
AB - PURPOSES: To clone and sequence the cDNA for Lp85 calpain from young rat lens,
and to test for Lp85 protein expression and proteolytic activity. METHODS: RT-PCR
and molecular cloning were performed on total RNA from 12 day-old rats. Lp85
protein expression was visualized by immunoblotting using a specific antibody
developed to the unique peptide sequence in Lp85. Proteolytic activity was
assessed by casein zymography. Transient expression of Lp85 and previously
characterized lens-specific calpain Lp82 were separately performed in mammalian
COS-7 cells. RESULTS: The 2410-bp cDNA for rat lens Lp85 encoded a protein of 737
amino acid residues with a calculated molecular weight of 85.0 kDa and a
predicted pI of 5.67. The amino acid sequence of Lp85 was identical to Lp82
except for an insert region of 28 amino acids in domain IV of the calcium-binding
region. mRNA and protein for Lp85 were present only in rat and mouse lenses and
not in other tissues or species. Lp85 protein concentrations were highest in the
nuclear region, most concentrated in the insoluble fraction, disappeared with
lens maturation, and Lp85 exhibited migration similar to Lp82 on native PAGE
gels. Lp85 was enzymatically active when expressed in COS-7 cells. CONCLUSIONS:
Lp85 is a newly classified, lens- and rodent-specific, enzymatically active,
member of the AX1 (alternative exon 1) subclass of calpains. In conjunction with
Lp82 and m-calpain in lens, Lp85 may be responsible for proteolysis during normal
lens development and maturation or during cataract formation in young rodents.
PMID- 10694894
TI - Open-loop accommodation in emmetropia and myopia.
AB - PURPOSE: To investigate the influence of method of measurement and refractive
error on the open-loop accommodation response. METHODS: Open-loop accommodation
was measured in darkness (dark accommodation, DA) and using a pinhole pupil
(pinhole accommodation, PA) in emmetropic subjects (EMMs, n = 63), subjects with
late-onset myopia (LOMs, n = 50) and subjects with early onset myopia (EOMs, n =
51). Further a control experiment examined the differences between DA and bright
field accommodation (BA) conditions in a subset of subjects. All measurements of
open-loop accommodation were carried out monocularly using a Canon R1 infra-red
optometer in static recording mode. All myopic subjects were fully corrected
using soft contact lenses. RESULTS: A significant variation (p < 0.001) in open
loop accommodation was found between DA and PA, but no variation in open-loop
level was observed between the three refractive groups. There was no interaction
between these two factors. No significant difference was found between the BA
level and DA level in any of the refractive groups. CONCLUSIONS: Open-loop
accommodation response positions vary according to the experimental conditions
employed during measurement. No refractive group differences in the open-loop
response were apparent.
PMID- 10694896
TI - Human retinal hemodynamics following administration of 5-isosorbide mononitrate.
AB - PURPOSE: The purpose of this randomized double-masked cross-over study was to
determine the effects of 20 mg of 5-isosorbide mononitrate (ISMO) on the retinal
hemodynamics of young healthy subjects. METHODS: Monochromatic fundus photography
and bidirectional laser Doppler velocimetry (BLDV) were used to determine
vascular diameters (D), and blood velocity (V(max)) and flow (Q) in retinal
veins, respectively. The diameter of the vein [D((vein))] at the same location
where BLDV measurements were made, and the diameter of a neighboring artery
[D((art) )], were determined from the fundus photographs. Measurements were
carried out one and three hours after ISMO dosing, on twelve and six subjects,
respectively. Mean blood pressure (BP(m)) and intraocular pressure (IOP) were
also monitored, and ocular perfusion pressure (PP) was calculated. Results are
expressed in percentage changes (+/- the standard error of the mean). RESULTS: On
average, we observed a moderate increase of Q one hour after ISMO dosing (+8.2 +/
5.4%), but not after placebo (+2.7 +/- 1.6%). This effect of ISMO, which
displayed remarkable interindividual variability (95% confidence interval: -3.9%,
+20.4%), did not attain statistical significance. D((vein)) and D((art)) were not
appreciably affected. No effect was observed three hours after either ISMO or
placebo dosing. PP was reduced one hour following ISMO administration, mainly as
a function of reduced BP(m), although this variation was not statistically
significant. IOP did not change appreciably throughout the duration of the study.
CONCLUSIONS: Our findings suggest that, in contrast to the optic nerve head, in
which we previously documented consistent and significant increases in blood flow
following ISMO administration at both one and three hours, retinal hemodynamics
are not equally responsive to a single dose of ISMO at these time points. Marked
interindividual variability to the effects of this long-acting nitric oxide donor
was documented one hour after administration, but not at three hours. This study
further suggests that distinct vascular tissues of the ocular microcirculation
respond differently to identical pharmacological challenges.
PMID- 10694897
TI - Correlation of metalloproteinase-2 and -9 with proinflammatory cytokines
interleukin-1b, interleukin-12 and the interleukin-1 receptor antagonist in
patients with chronic uveitis.
AB - PURPOSE: Matrix metalloproteinases have been shown to play a role in active
uveitis. Transcription of MMPs is induced by a number of growth factors and
cytokines. This study investigates the role of MMPs in chronic uveitis and
correlates the amounts of MMP-2 and -9 in intraocular samples to the intraocular
levels of proinflammatory cytokines (Interleukin-1 [IL-1], Interleukin-12 [IL-12]
and Interleukin-1 receptor antagonist [IL-1ra]). METHODS: Aqueous humor of 16
patients was collected during surgical or diagnostic procedures (control group:
cataract patients). MMP-2 and -9 were measured using zymography. IL-1beta, IL-12
and IL-1ra were evaluated by ELISA. RESULTS: We found MMP-2 and -9 in all of our
uveitis patients. In the control group only MMP-2 was seen. Higher levels of MMP
2 and -9 were found in patients with higher activity of uveitis (p < 0.014 for
MMP-2, p < 0.0054 for MMP-9). The amounts of IL-1beta, IL-12 and IL-1ra detected
in our uveitis patients correlated with levels of MMP-2 (p < 0.07, p < 0.0004, p
< 0.03) and MMP-9 (p < 0. 003, p < 0.0001, p < 0.002), and IL-12 (p < 0.004, p <
0.0001). Patients with moderately active uveitis presented with twice the level
of MMP-2 as the control group; MMP-9 levels reached up to 92% of the amounts
found in patients with active uveitis. Two patients in remission for almost one
year still had detectable intraocular MMP-9 levels. CONCLUSION: Our data suggests
that the high levels of MMPs found in patients with chronic uveitis might
contribute to the damage often seen in these eyes. Since MMPs are capable of
releasing proinflammatory cytokines bound to components of the extracellular
matrix, and facilitate the secretion of active TNF-alpha by cleavage of the
membrane bound form, it is conceivable that MMPs contribute to the chronicity of
some uveitis cases.
PMID- 10694895
TI - Expression of the extraneuronal monoamine transporter in RPE and neural retina.
AB - PURPOSE: Dopamine has several important functions in the retina including a
possible role in controlling photoreceptor disk shedding to the RPE. While some
cells express a transporter for dopamine, the RPE cell does not, leading us to
ask whether the newly described catecholamine transport system, the extraneuronal
monoamine transporter (uptake(2)) (also known as organic cation transporter 3
(OCT3), is present in RPE and might function as a transporter for dopamine. OCT3
also accepts histamine as a transportable substrate and so we investigated the
interaction of this retinal neurotransmitter with OCT3. METHODS: OCT3 expression
in the mouse eye was analyzed by in situ hybridization, Northern blot analysis
and RT-PCR. OCT3 function was analyzed in cultured human ARPE-19 cells by
monitoring the uptake of 1-methyl-4-phenyl pyridinium (MPP(+)), a neurotoxin,
which is a known substrate for OCT3. RESULTS: In situ hybridization analysis
showed that OCT3 is expressed in mouse RPE and in several cell types of the
neural retina, including photoreceptor, ganglion, amacrine, and horizontal cells.
The expression of OCT3 in RPE was confirmed by Northern blot analysis and RT-PCR.
The characteristics of MPP( +) uptake in cultured ARPE-19 cells included the
stimulation of transport by alkaline pH, high affinity (K(t) = 28 +/- 4 microM),
competition with several cationic drugs and monoamine neurotransmitters and
sensitivity to steroids. In addition, the uptake of MPP(+) in RPE cells was
inhibited by dopamine and histamine with IC(50) values (concentration needed for
50% inhibition) of 637 +/- 84 microM and 150 +/- 20 microM, respectively.
CONCLUSIONS. This study provides the first report on the expression and function
of an organic cation transporter, OCT3, in the eye and in particular the RPE. The
data have physiological and pharmacological relevance as it is likely that OCT3
participates in the clearance of dopamine and histamine from the subretinal space
and may also play a key role in the disposition of the retinal neurotoxin MPP(+).
PMID- 10694898
TI - Genistein produces reduction in growth and induces apoptosis of rat RPE-J cells.
AB - PURPOSE: To investigate the effect of the tyrosine kinase inhibitor, genistein,
on the growth of the retinal pigment epithelial (RPE) cell. METHODS: The tyrosine
kinase inhibitor, genistein, was administered in culture to the rat retinal
pigment epithelial cell line, RPE-J. The effect on cell viability and growth was
assessed by trypan blue dye exclusion. Induction of apoptosis was confirmed
morphologically by light and electron microscopy and oligonucleosomal
fragmentation was assessed by TUNEL and DNA ladder. Quantitation was undertaken
by propidium iodide staining and photometric enzyme immunoassay. Western blot was
performed to study poly-(ADP-ribose)-polymerase cleavage (PARP). To confirm the
involvement of caspase, the caspase inhibitor z-VAD-fmk was employed. In
addition, cell cycle phase was determined by flow cytometry. RESULTS: We here
demonstrate that genistein treatment of RPE-J cells produces a dose- and time
dependent growth inhibition. Genistein in higher concentration induces apoptosis
of rat RPE-J cell. z-VAD-fmk inhibited this type of apoptosis and cleavage of
PARP enzyme was demonstrated. Ten micromolar genistein inhibited cell
proliferation by G(0)/G(1) arrest without inducing apoptosis of the major
population. Whereas 50 microM genistein caused growth inhibition of RPE-J cells
by G(2)/M arrest and subsequent apoptotic death. CONCLUSIONS: Genistein inhibits
RPE cell growth and induces apoptosis. The ability of genistein to inhibit the
proliferation and to induce apoptosis of RPE cells could be potentially
therapeutic for proliferative vitreoretinopathy.
PMID- 10694899
TI - Effect of melatonin against oxidative stress in ultraviolet-B exposed rat lens.
AB - PURPOSE: To investigate the defensive effect of melatonin against oxidative
stresses in ultraviolet-B (UVB) radiation induced cataract development. METHODS:
Young rats received 8 kJ/m(2) UVB for 15 min. For the intervention of cataract
development intraperitoneal injection of melatonin (4 mg/kg daily for 1 week)
following UVB exposure was performed. Lenticular glutathione peroxidase (GSHPx),
catalase (CAT), superoxide dismutase (SOD) activities and glutathione (GSH),
malondialdehyde (MDA) levels were determined in UVB-melatonin, UVB, and control
groups. RESULTS: One week after exposure in the UVB group, lens opacities were
observed and CAT, SOD, and GSHPx activities, and GSH level were lower than
control and MDA level was higher than control (p < 0.05). In the UVB-melatonin
group CAT and SOD activities were lower than control (p < 0.05), and the MDA
level was lower than the UVB group (p < 0.05). CONCLUSIONS: These results suggest
that melatonin may protect against the UVB-induced cataract development by
directly quenching lipid peroxides and indirectly by enhancing the production of
the endogenous antioxidant GSH.
PMID- 10694900
TI - Morphologic preservation and variability of human donor retina.
AB - PURPOSE: To facilitate studies of human retina and utilization of human retinal
tissue for treatment of retinal diseases, we studied morphologic preservation in
postmortem human retina. METHODS: Morphology of retinas from thirty-one human
eyes was examined using light and electron microscopy. The inner and outer
retina, rod and cone photoreceptor cells, and central and peripheral retina were
compared with regard to morphologic preservation. Possible factors affecting
survival were analyzed. RESULTS: The earliest postmortem change was vacuolation
of the nerve fiber layer within a few hours postmortem, followed by vacuolation
and cytoplasmic swelling of the inner retina. As compared with the inner retina,
outer retinal structure was better preserved, i.e., the photoreceptor cells
maintained better morphology. Rod cell morphology was better preserved than cone
cell morphology, with good preservation of the rod outer segment disc membranes
and the inner segment mitochondrial membranes. Thus, well-preserved rod
photoreceptor cells were evident in specimens at least 48-hours postmortem.
Peripheral retina was better preserved than the central retina including the
fovea and perifovea. Factors affecting anatomical integrity included the total
time postmortem and, more importantly, the time between death and enucleation.
Other factors, including age and sex, did not appear to affect morphological
preservation in the present study. CONCLUSIONS: Human retina postmortem remained
morphologically intact for a relatively long period of time, with differential
preservation among different geographic areas and cell types. This morphologic
evidence is consistent with previous findings of functional preservation (e.g. ,
photoresponses) in such tissue. This study may shed some light on understanding
of human retina and its utilization for retinal transplantation.
PMID- 10694901
TI - Molecular identification of functional water channel protein in cultured human
nonpigmented ciliary epithelial cells.
AB - PURPOSE: Water channel proteins are important pathways for water movements across
cell membranes, including those in the ciliary epithelium, which is the major
site of aqueous humor secretion. In this study, we aimed to demonstrate the
expression of functionally active aquaporin-1 (AQP1) water channels in cultured
human ciliary epithelial cells. METHODS: Poly A(+) RNA was isolated from cell
cultures of Simian Virus 40 (SV-40) transformed human nonpigmented ciliary
epithelium (NPE) subjected to RT-PCR reaction using primers specific to AQP1.
Northern analysis was used to define the expression of AQP1 in NPE cells. Western
immunoblotting with polyclonal antibody raised against AQP1 was used to evaluate
the AQP1 protein expression in the plasma membranes of human NPE cells. Light
scattering method was used to determine the osmotic water permeability in the
suspension of NPE cells. RESULTS: RT-PCR using specific primers for AQP1,
Northern analysis and Western immunoblot using AQP1 specific antibody
demonstrated the expression of AQP1 in the plasma membranes of NPE cells. Osmotic
water permeability (P( f)) measurements confirmed that functional AQP1 water
channels are expressed in human NPE cells and the P(f) for these cells was 9.8 x
10( -3) cm/s at 10 degrees C. CONCLUSIONS: The presence of AQP1 in human NPE
cells suggests that it may have a role in the fluid flow across epithelial
membranes. In addition, the existence of AQP1 in the human NPE cells provide an
excellent in vivo model to study the regulation of aquaporins and their possible
role in the aqueous humor secretion.
PMID- 10694902
TI - Inter-ocular characteristics of the pre-contact lens tear film.
AB - PURPOSE: To establish whether the status of the pre-contact lens tear film as
indicated by standard, clinical observational techniques is affected by moderate
stimulation of the contralateral eye. METHODS: Four indicators of tear film
behavior, lipid layer appearance, amount of debris, inferior meniscus height and
non-invasive tear break up time (NIBUT) were monitored in ten subjects before and
during 30 minutes of monocular pHEMA contact lens wear. Concurrently, the
contralateral eye was either subjected to moderate irritation by means of a
silicone elastomer contact lens, or remained unstimulated. Data were compared,
between the stimulated and unstimulated states to identify evidence of
contralateral treatment effects. RESULTS: After 30 minutes, maximum contralateral
differences between the unstimulated and stimulated conditions were 1 grade for
both lipid layer appearance and debris, 0.1 mm for meniscus height and 4 secs for
NIBUT. CONCLUSIONS: The magnitudes of contralateral effects induced by moderate,
monocular irritation were comparable with the within-subject variabilities
associated with these indicators of tear film behavior.
PMID- 10694903
TI - Ultrastructural histochemical studies of secretory processes in rat submandibular
granular tubules during intermittent sympathetic nerve stimulation.
AB - Secretory changes in the cells of granular tubules in rat submandibular glands
have been studied sequentially during electrical stimulation of their sympathetic
nerves. Results were assessed in a series of biopsied lobes from the same gland,
taken at different times during the sympathetic stimulation. Changes were not
synchronous between adjacent cells and it appeared that the time for the onset of
secretory events differed between cells but, once set in action, a chain of
similar events occurred. Nevertheless, some cells appeared to remain refractory
throughout. Initially, some alignment of granules to the adjacent plasma membrane
occurred and occasional evidence for classical exocytosis was seen. However, from
early on microvesicles appeared in more luminally located granule membranes and
were associated with granule fusions, that became common and led to the formation
of large irregular aggregates. Most of the secretion of granule contents appeared
to be through openings of aggregates into lumina. With granule fusions the intra
membrane microvesicles became internalised and tended to increase in size with
time; they were commonly expelled with the contents of the aggregates. Fragments
of cytoplasm also became incorporated in aggregate formation. Cytoplasm, often
containing glycogen, also formed luminal blebs over some granular tubule cells
and appeared to pass into the secretion by an apocrine process. At the end of
stimulation multivesicular bodies were seen in association with redundant
aggregates.
PMID- 10694904
TI - Changes in numbers and dimensions of glomeruli during metamorphosis of Pelobates
syriacus (Anura; Pelobatidae).
AB - Changes in glomerular numbers and volume were followed throughout five
ontogenetic stages of Pelobates syriacus (Anura, Pelobatidae). The number of
glomeruli increased markedly between the 2-legged and the 4-legged tadpole
stages. In the post-metamorphic stages the number of glomeruli was about twice
their number during the tadpole stages. Glomerular volume peaked during the 2
legged tadpole stage, when the tadpole reached its maximal size, and dropped
thereafter. There is some evidence to indicate that the number of glomeruli in
post-metamorphic P. syriacus increased during growth thus indicating perhaps an
increase in their functional importance. The number was still lower than that
reported for some other anurans, more similar to the numbers given for
representative urodeles, however, the latter have considerably larger glomeruli.
Two main factors appear to be involved in regulating numbers and volume of
glomeruli in frogs. The ontogenetic changes during metamorphosis affect both
glomerular numbers and volume, whereas post-metamorphic growth affected only the
glomerular numbers.
PMID- 10694905
TI - Effect of genistein on the temporal coordination of cleavage and compaction in
mouse preimplantation embryos.
AB - Initially, we investigated the effect of genistein, an inhibitor of protein
tyrosine kinases, on compaction of the mouse embryo since tyrosine
phosphorylation of the cadherin-catenins complex was suggested to down-regulate
its adhesive function. Genistein prevented cleavage from the 2- to the 4-cell
stage in a concentration-dependent manner. The next cleavage is inhibited at all
concentrations used. Time course of intercellular flattening is however identical
for both control 8-cell embryos and 4-cell arrested embryos. This confirms that
compaction takes place according to a biological clock that does not depend on
completion of the third cell cycle. Our results also suggest that, since, in
contrast to genistein, protein kinases C modulators are known to cause a
premature compaction, diacylglycerol-dependent kinases but not protein tyrosine
kinases might be upregulators of compaction.
PMID- 10694906
TI - The Harderian gland of the Cheesman's gerbil (Gerbillus cheesmani ) of the
Kuwaiti desert.
AB - The Harderian gland is a large orbital structure. Several functions have been
ascribed to the gland such as lubrication of the eye, a source of pheromones,
thermoregulartory lipids and photoprotective secretions and a part of the retinal
pineal axis. In the present study, the Harderian gland of the Cheesman's gerbil,
Gerbillus cheesmani, is described for the first time. The gland is located around
the posterior portion of the eyeball. The gland is compound tubular, surrounded
by a thin connective tissue capsule. Only one secretory epithelial cell type was
recognized, characterized by the presence of lipid vacuoles and cytoplasmic
slashes in high numbers; the former being more concentrated towards the apical
part while the latter being more concentrated towards the central and basal
parts. Some of the cytoplasmic slashes contained electron dense filamentous
structures. Similar structures were observed in the lipid vacuoles. Thus, a
functional relationship between the cytoplasmic slashes and the lipid vacuoles is
suggested. A unique structure was observed, termed dome-like cells, located
between the epithelial cells and the basement membrane. These cells were
characterized by the extensive presence of pleomorphic mitochondria and compact
lamellae of granular endoplasmic reticulum (GER) in the form of finger prints.
The gland was found to be actively secreting porphyrins as well as lipids.
Cellular debris was also seen in the tubular lumina. Myoepithelial cells with
their spindle shape and elongated nuclei were evident between the basement
membrane and the secretory epithelium. Sparse interstitial tissue was observed in
between the gland tubules of both male and female gerbils. Macrophages, dendritic
melanocytes and lymphocytes are the most represented cellular components of the
interstitium. Further studies are required to investigate the function of the
dome-like cells as well as the role of lymphocytes in the rodents Harderian
gland.
PMID- 10694907
TI - Microwave processing for scanning electron microscopy.
AB - The normal processing of biological samples for Scanning Electron Microscopy,
includes treatment with aldehyde (1 to 2 hours), postfixation with Osmium (1
hour), followed by dehydration in a ascending grade of ethanol (30 a 100%), 10 to
15 minutes in each step, and finally drying. This procedure takes at least 8
hours. In this work, samples of mosquitoes (Aedes), protozoa (Tritrichomonas
muris), bacteria (Clostridium oceanicum), murine liver, and small intestine were
processed in the same manner in a domestic microwave oven for two minutes at 20%
of its maximum power. The complete procedure from the initial fixation to
dehydration in 100% ethanol was reduced to one hour with good preservation of the
ultrastructural details of the specimens.
PMID- 10694908
TI - Mechanical properties and chemical composition of avian long bones.
AB - We have studied the mechanical behaviour of avian long bones as whole structures,
by calculating mechanical parameters such as maximum load, stiffness, bending
strength and flexural Young's modulus; bones were always tested in three-point
bending. Furthermore composition in several chemical elements and amino acids
related to collagen content was also analysed. Correlations were established
between body mass, mechanical parameters and chemical contents. Both bending
strength and Young's modulus were negatively correlated to body mass. Significant
correlations were found between nitrogen content and both strength and Young's
modulus, with negative slopes in both cases. Magnesium and phosphorus appear to
be the most important inorganic elements to the understanding of the mechanical
behaviour of avian long bones.
PMID- 10694909
TI - Closure of the uterine lumen and the plasma membrane transformation do not
require blastocyst implantation.
AB - Ultrastructural changes in the plasma membrane of uterine epithelial cells in the
pseudopregnant rat were examined to determine if these changes resemble those
found during normal pregnancy and also to examine if the well-known membrane
alterations of early pregnancy are intrinsic to uterine epithelial cells. Changes
in the surface contours of uterine epithelial cells from the afternoon of day 6
to the morning of day 9 of pseudopregnancy were similar to those present after
attachment in normal pregnancy although somewhat delayed. The presence of short,
irregular microvilli was seen from as early as day 7 of pseudopregnancy, with
regular microvilli returning to the epithelial surface by days 8-9 of
pseudopregnancy but to a slightly lesser extent as compared to normal pregnancy.
Furthermore, observations made on the afternoon of day 6 to the morning of day 7
of pseudopregnancy showed that the uterine lumen was closed down and that
complete membrane flattening between opposing uterine epithelial cells was seen
all along the uterus in the absence of a blastocyst. These observations establish
that the "plasma membrane transformation" does not depend on blastocyst
implantation.
PMID- 10694910
TI - The relationship of callosal anatomy to paw preference in dogs.
AB - Previous studies have described the paw preference and asymmetry in dog brains,
based on experimental studies. The purpose of the present study is to investigate
a possible association between callosal anatomy and paw preference in dogs. The
midsagittal area of the dog corpus callosum was measured in its entirety and in
six subdivisions in a sample of 21 brains obtained from 9 male and 12 female
mongrel dogs which had paw preference testing. The present study showed
significant paw differences in dog corpus callosum. A posterior segment of the
callosum, the isthmus, was significantly larger in the right pawedness than the
left.
PMID- 10694911
TI - Electron microscopic contrast of the cytoskeleton and junctional complexes of
intestinal epithelial cells by ethanolic phosphotungstic acid.
AB - After glutaraldehyde fixation and treatment with ethanolic phosphotungstic acid
(E-PTA) before plastic embedding, sections of rat large intestine showed a
characteristic electron contrasting pattern in epithelial cells. The axis of
microvilli, terminal web, a thin band below the luminal plasma membrane,
centrioles and junctional complexes (tight junctions, adherens junctions, and
desmosomes) appeared highly contrasted. In addition to protein components of
microfilaments and intermediate filaments, proteins from the junctional complexes
could also be implicated in the contrasting reaction with E-PTA. Mitochondrial
membranes, chromatin masses, and nucleoli of enterocytes showed considerable
electron density, whereas no reaction was found in the glycocalyx and mucin
content of goblet cells. The clear visualization of cytoskeleton elements and
junctional complexes by E-PTA contrasting represents a simple and valuable method
for studies on the normal and pathological organization of these structures in
epithelial cells.
PMID- 10694912
TI - Effect of infantile strabismus on visuomotor development in the squirrel monkey
(Saimiri sciureus): optokinetic nystagmus, motion VEP and spatial sweep VEP.
AB - PURPOSE: To determine whether squirrel monkeys made artificially strabismic in
infancy had ocular fixation abnormalities, directional asymmetries of horizontal
optokinetic nystagmus (OKN) and asymmetries of motion visually evoked potentials
(MVEPs) similar to those of humans with infantile strabismus. METHODS: Esotropia
was produced in a newborn squirrel monkey by surgical tenotomy of both lateral
rectus muscles. The alignment and eye rotations of the monkey were examined
longitudinally and VEP testing was performed at the age of one year. Visual
acuity was measured using spatial frequency sweep VEPs (SSVEP) in response to
grating stimulation. OKN was tested under conditions of monocular viewing using
full-visual-field, vertically oriented, moving stripes. MVEPs in response to
horizontal motion were recorded with the animal sedated to reduce the possibility
of eye movement artifact. RESULTS: The artificially strabismic squirrel monkey
displayed a constant, committant esotropic strabismus accompanied by latent
nystagmus. Monocular SSVEP acuity was subnormal in one eye, consistent with mild
monocular strabismic amblyopia. The monkey demonstrated asymmetric OKN favoring
nasally-directed stimulus motion when viewing with either eye. Monocular MVEPs
were also characterized by a horizontal asymmetry with a directional bias
inverted 180 degrees between the right and the left eyes. The eye movements and
MVEP asymmetries were similar to those observed in strabismic macaque monkeys and
humans with early-onset strabismus. Neither the OKN asymmetry nor the MVEP
asymmetry was evident in a normal squirrel or normal macaque monkey. CONCLUSION:
The artificially strabismic squirrel monkey is an appropriate eye movement and
VEP model for the study of neural mechanisms in human infantile strabismus.
PMID- 10694913
TI - Effect of botulinum toxin injections into rabbit eye.
AB - The aim of this study was to investigate the adverse effects of the intraocular
injection of botulinum toxin in rabbits. Intravitreal injections of botulinum
toxin A in five doses, 1.25, 2.5, 5, 10, 25 units, were given into five rabbit
eyes. The same volume of saline was injected into the second eye of the rabbit as
a control. External examination, ophthalmoscopy, visual evoked potentials and
electroretinography were done before injection and repeated at the first and
second weeks after the injection. There were no significant differences in
retinal function between toxin- and saline-injected eyes, neither
ophthalmoscopically nor electrophysiologically. Ipsilateral mydriasis developed
in the eyes injected with botulinum toxin. This study suggests that botulinum
toxin has no harmful effect on retinal function.
PMID- 10694914
TI - Results of classical and augmented bimedial rectus recession in infantile
esotropia.
AB - PURPOSE: To compare the success rates of augmented bimedial rectus recession and
the standard recession. MATERIALS AND METHODS: Ninety patients were included in
the study. The patients were evaluated in two groups according to the amount of
recession. Group 1, the standard surgery group, received 5 mm or less of
recession; Group 2, the augmented surgery group, received 6 mm of recession or
more. The mean postoperative follow-up was 29 months (6-60 months) in Group 1,
and 20 months (6-58 months) in Group 2. RESULTS: The mean age at the time of
surgery was 4.61 years in Group 1 and 4.58 years in Group 2. The 56 patients in
Group 1 underwent bilateral rectus recession varying from a minimum of 3 mm to a
maximum of 5 mm; the 34 patients in Group 2 had recessions varying from a minimum
of 6 mm to a maximum of 8 mm. The mean preoperative angle size was 39.64 +/- 8.93
SD (range 20-50 PD) in the standard surgery group, and 59.70 +/- 10. 04 SD (range
51-85 PD) in the augmented surgery group. The average postoperative deviation was
13.37 +/- 11.87 SD (range 0-45) in Group 1 and 9.02 +/- 10.02 (range 0-45) in
Group 2. A good surgical result was achieved with one operation in 29 of 56
patients (51.8%) in Group 1 and 24 of 34 patients (70.58%) in Group 2.
DISCUSSION: The optimal surgical technique for the correction of large-angle
esotropia is still controversial; it appears that the augmented bilateral medial
rectus recession is an effective and reasonable alternative to three- or four
muscle procedures as the initial surgical treatment.
PMID- 10694915
TI - The role of vergence adaptation in recovery of binocular single vision (BSV)
following sensory strabismus.
AB - Vergence adaptation is an important element of comfortable binocular single
vision and probably contributes to the high incidence of orthophoria or small
angles of heterophoria in the normal population. Where binocular single vision
has been absent for a period of time, restoration of good visual acuity appears
to enable the vergence adaptation mechanism to become active again. A case is
presented in which a moderate to large angle of deviation rapidly 'disappeared'
once good visual acuity was restored and the disparate images could be fused.
Known factors concerning vergence adaptation are discussed in relation to such
clinical cases.
PMID- 10694916
TI - Novel compound heterozygous laminina2-chain gene (LAMA2) mutations in congenital
muscular dystrophy. Mutations in brief no. 159. Online.
AB - The laminina2-chain gene (LAMA2) encodes a basal lamina protein, laminina2, known
to be deficient in one form of congenital muscular dystrophy (CMD). In a
laminina2 deficient-CMD patient, we screened the entire LAMA2 cDNA (953bp) by
reverse transcriptase polymerase chain reaction combined with single strand
conformational polymorphism analysis. Direct sequencing of aberrant conformers in
this patient revealed two loss-of-function mutations, consistent with autosomal
recessive inheritance. The patient had two novel heterozygous mutations: 1) an
exon 4 nonsense mutation caused by a G-->A substitution at cDNA position 547,
changing the TGG codon for tryptophan into a TGA stop codon (W166X) in the N
terminus domain VI;ii) an exon 54 frameshift mutation due to a deletion of
nucleotide 'C' at cDNA position 7707 (S2553Y), resulting in a premature stop
codon (V2587X) in exon 55 in the globular G domain of laminina2 at the C
terminus. These mutations cause a disruption of the open reading frame of LAMA2.
The absence of laminina2 observed in the patient's muscle biopsy could result
from diminished levels of the LAMA2 transcript. Alternatively, the mutations
might lead to translation of a truncated laminina2. By either mechanism the
phenotype of congenital muscular dystrophy is believed to be the result of
disruption of linkage between the extracellular matrix and the dystrophin
glycoprotein complex.
PMID- 10694917
TI - Transthyretin Ile73Val is associated with familial amyloidotic polyneuropathy in
a Bangladeshi family. Mutations in brief no. 158. Online.
AB - Amyloidosis is characterised by the extraceullular deposition of certain
different proteins in a distinctively abnormal fibrillar conformation. All types
of amyloid fibril share remarkably similar structural and biophysical properties
despite substantial chemical heterogeneity among their respective precursor
proteins. Hereditary amyloidosis associated with genetically determined protein
variants is rare, but is extremely important as a model for studying the
pathogenesis of amyloidosis generally. We report a novel mutation of the
transthyretin (TTR) coding for TTR Ile73Val which is associated with familial
amylodotic polyneuropathy (FAP) in a Bangladeshi family. The mutation was
detected by direct sequencing of the PCR-amplified TTR exons. It creates an
additional Accl restriction exzyme site in exon 3, allowing confirmation of its
presence by RFLP. Amyloid detected in sural nerve and colonic biopsies was shown
to be composed of TTR by immunohistochemistry. The predominant clinical features
were progressive autonomic and sensori-motor peripheral neuropathy, beginning at
age 50 years. The proband's father and two siblings had similar illnesses. These
findings indicate Val73 is an amyloidogenic variant of TTR.
PMID- 10694918
TI - A nonsense mutation (R242X) in the branched-chain alpha-keto acid dehydrogenase
E1alpha subunit gene (BCKDHA) as a cause of maple syrup urine disease. Mutations
in brief no. 160. Online.
AB - Mutation analysis of DNA from cultured amniocytes with absent branched-chain
alpha-ketoacid dehydrogenase activity revealed a C to T transition producing a
nonsense mutation (R242X) in exon 7 of the gene encoding the E1a subunit of this
multienzme complex (BCKDHA). This pregnancy occured in a large consanguinous
pedigree with mutiple individuals with maple syrup urine disease (MSUD). PCR
amplification of the region surrounding exon 7 allowed the identification of this
mutation as well as two other previously identified mutations which cause MSUD.
PMID- 10694919
TI - Niemann Pick Disease type A in Israeli Arabs: 677delT, a common novel single
mutation. Mutations in brief no. 161. Online.
AB - A novel single base pair deletion in the acid sphingomyelinase (ASM) gene
(677delT in the cDNA) was identified in 12 Israeli Arab families with Niemann
Pick disease (NPD) type A. This deletion creates a premature stop codon which
explains the complete deficiency of ASM activity in these patients and the severe
clinical manifestation. A single mutation in 12 families living in a relatively
small geographical region suggests a founder effect and explains the high
frequency of this disease in this population. This is in contrast to multiple
mutations found in two other lysosomal storage disorders prevalent in this
population, namely, Hurler disease (MPSI) and metachromatic leukodystrophy.
Mutations analysis is therefore an important tool in characterizing the grounds
for the high frequency of inherited diseases as well as a basis for prevention
programs for prevalent diseases through carrier identification and the
ascertainment of high risk families.
PMID- 10694920
TI - Three novel missense mutations in the glucokinase gene (G80S; E221K; G227C) in
Italian subjects with maturity-onset diabetes of the young (MODY). Mutations in
brief no. 162. Online.
AB - The maturity-onset diabetes of the young (MODY), an autosomal dominant form of
non-insulin dependent diabetes mellitus (NIDDM), is caused by mutations in the
glucokinase (GK, MODY 2) and in the hepatocyte nuclear factor 1a (MODY 3) and 4a
(MODY 1) genes. We have screened the glucokinase gene by the polymerase chain
reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) in fifteen
subjects with clinical characteristics of MODY and one parent with NIDDM,
impaired glucose tolerance or gestational diabetes. PCR products with abnormal
mobility in DGGE were directly sequenced. We have identified four mutant alleles,
three of them (G80S, E221K, G227C) are new missense mutations located in or near
the region of the active site cleft of the enzyme. The mutations co-segregate
with hyperglycemia in the families of the three probands, whose biochemical and
clinical phenotype is similar to other individuals with MODY 2 mutations.
PMID- 10694921
TI - A novel mutation in the neonatal region of the fibrillin (FBN)1 gene associated
with a classical phenotype of Marfan syndrome (MfS). Mutations in brief no. 163.
Online.
AB - Marfan Syndrome (MfS) is an autosomal dominant inherited connective tissue
disorder with variable phenotypic expression of cardiovascular, skeletal and
ocular manifestations. Cardiovascular complications, such as aortic aneurysm and
dissection drastically reduce life expectancy of individuals with MfS, whereas
preventive surgery substantially improves the prognosis of these patients. A
number of mutations in the fibrillin 1 (FBN1) gene associated with MfS have been
identified to date, demonstrating considerable molecular heterogeneity. One
region, however, located around exon 24, exhibits a striking clustering of
mutations, which are associated with a severe, socalled neonatal form of MfS.
Here we report the first mutation (G2950A) in exon 24 of the neonatal region of
the FBN1 gene, associated with a classic MfS phenotype. The mutation leads to the
subsitution of valin by isoleucin (V984I), both uncharged amino acids, which only
differ in a single methyl group. This defect was identified in a proband with
cardiovascular manifestations of MfS by SSCP analysis of PCR-amplified genomic
DNA, direct PCR sequencing and RFLP analysis. The substitution was neither
detected in the unaffected 4-year old daughter of the proband, nor in 3 of his
healthy family members nor in 108 allels from control individuals, suggesting
that this mutation is causative for MfS in the patient. Since no other family
member of the proband is affected by MfS, the defect described is sporadic. In
summary, we identified a novel defect in exon 24 of the neonatal region of the
FBN1 gene in a patient with a classic phenotype of MfS, suggesting that
conservative substitutions in this region may lead to a less severe phenotype of
the disease. This finding further demonstrates the remarkable phenotypic
heterogeneity associated with FBN1 mutations and stresses the significance of
modifying genes and individual alterations in protein function for the pheontypic
expression of the disease.
PMID- 10694922
TI - Novel missense and frameshift mutations in the activin receptor-like kinase-1
gene in hereditary hemorrhagic telangiectasia. Mutations in brief no. 164.
Online.
AB - Hereditary hemmorrhagic telangiectasia (HHT) is an autosomal dominant disorder
characterized by multisystemic vascular dyplasia and recurrent hemorrhage. One of
the causative genes is the activin receptor-like kinase-1 (ALK-1) gene located on
chromosome 12q13. ALK-1 is an endothelial cell type I receptor for the TGF-beta
superfamily of ligands. As a number of mutations have been identified in the
kinase domain of ALK-1, we initiated a mutation analysis specifically targeting
the first four coding exons of ALK-1 in order to determine if mutations in the
extracellular and transmembrane domains are also present in HHT. Six new
mutations have been identified. Three frameshift mutations were identified in
exons encoding the extracellular and transmembrane domains. These mutations would
grossly truncate the ALK-1 protein and are thus classic null alleles. Three new
missense mutations within the exons encoding the extracellular domain, in
addition to two previously described missense mutations, are located at or near
highly conserved cysteines. These mutations may disrupt intra- or inter-molecular
disulfide bridges required for ligand binding. The combined data suggest that
both severe and subtle changes in the ALK-1 amino acid sequence can lead to
receptor dysfunction and result in the HHT disease phenotype.
PMID- 10694923
TI - C112R, W323S, N317K mutations in the vasopressin V2 receptor gene in patients
with nephrogenic diabetes insipidus. Mutations in brief no. 165. Online.
AB - Nephrogenic diabetes insipidus (NDI) is a rare, mostly X-linked recessive
disorder characterized by renal tubular resistance to the antidiuretic effect of
arginine vasopressin. The gene responsible for the X-linked NDI, the G-protein
coupled vasopressin V2 receptor, has been localized on the Xq28 region. In this
study we present three NDI families from Hungary with three different missense
mutations in the vasopressin V2 receptor gene. After the mutations in the
affected probands in each family had been characterized, other family members
were screened by restriction enzyme analysis. The N317K and W323S mutations have
not been detected previously. The C112R is an already known mutation. The N317K
was a de novo mutation in the patient. The C112R and the W323S were found in the
mothers of the patients as carriers and in all other patients, but not in the
unaffected members of the families. Segregation of the mutations was consistent
with the clinically observed symptoms as well as their severity. As conclusion,
these findings further evidence that X-linked NDI results from defects in the V2
receptor gene.
PMID- 10694924
TI - Identification of a new heterozygous point mutation in the COL1A2 gene leading to
skipping of exon 9 in a patient with joint laxity, hyperextensibility of skin and
blue sclerae. Mutations in brief no. 166. Online.
AB - A heterozygous deletion of exon 9 in the COL1A2-mRNA of a patient with symptoms
of both the Ehlers-Danlos-Syndrome and the Osteogensis Imperfecta is described.
In the genomic DNA of the patient, exon 9 is homozygously present. We identified
a novel heterozygous point mutation in the splice donor site of intron 9, leading
to a G-->A substitution in position +5. This mutation leads to heterozygous
skipping of exon 9 in the COL1A2-mRNA of this patient. The deletion results in a
shortened (by 18 amino acids) but in frame 12(1) chain, which probably leads to
the formation of abberantly processed triple helices.
PMID- 10694925
TI - Identification of novel PAX6 mutations in two families with bilateral aniridia.
Mutations in brief no. 167. Online.
AB - We report two novel PAX6 mutations in aniridia patients of two Swiss pedigrees
(We, Sc) which give rise to different phenotypes. An SSCP analysis of the PAX6 14
exons reveals electrophoretic mobility shifts exclusively in exons 5 and 12 of
aniridia patients. As determined by bidirectional sequencing and restriction
digest analysis, these shifts are caused by mono-allelic base transitions in exon
5 (c.547C-->T; R44X; We) and intron 12 (IVS12+5G-->A; Sc). Each mutation co
segregates with the trait in the affected family with complete penetrance. The Sc
mutation in the splicing donor site of intron 12 may result in either intron
inclusion or exon skipping, both giving rise to a truncated PAX6 protein which
may retain a residual transactivating activity. In contrast, the We genetic
alteration is a loss-of-function mutation leading to a more severe phenotype than
that observed in the Sc pedigree.
PMID- 10694926
TI - A novel homozygous nonsense mutations E135* in the type II 3beta-hydroxysteroid
dehydrogenase gene in a girl with salt-losing congenital adrenal hyperplasia.
Mutations in brief no. 168. Online.
AB - Mutations in the 3beta-hydroxysteroid dehydrogenase (3beta-HSD) type II gene have
been reported in a small number of affected females. We report a 46,XX girl born
to consanguineous parents from Chile. At birth, she had normal but hyperpigmented
female external genitalia. At 60 days she presented salt loss. At 20 months, the
diagnosis of classic salt-losing 3beta-HSD deficiency was made based on an
elevated serum 17-hydroxpregnenolone concentration and a high 17
hydroxypregnenolone/17-hydroxyprogesterone ratio. Genomic DNA was amplified by
PCR and screened for mutations by denaturing gradient gel electrophoresis and
directly sequenced. A novel homozygous E135* mutation was found in the 3beta-HSD
type II gene of the patient while her parents were heterozygotes. This novel
nonsense homozygous E135* mutation led to encode a predicted truncated 134 amino
acid protein instead of the native 371 amino acid 3beta-HSD type II protein. This
predicted product is consistent with the severe 3beta-HSD deficiency in this
girl.
PMID- 10694927
TI - The distal boundary of myogenic primordia in chimeric avian limb buds and its
relation to an accessible population of cartilage progenitor cells.
AB - Using chimeras consisting of chick embryos that had received substitution grafts
of quail somites, we have determined the distalmost extension of the myogenic
primordia in the outgrowing wing bud at 5 days of incubation. At Hamburger
Hamilton stage 25 the most distal premuscle cell is consistently 300 mum or more
from the apex of the wing mesoblast. The stage 25 wing tip resembles very early
whole limb buds in not having proceeded beyond the mesenchymal state or having
expressed markers of terminal differentiation. However, unlike early whole limb
buds it is free of a myogenic subpopulation. We therefore propose that the stage
25 wing tip is the appropriate system for in vitro and molecular studies of
cartilage differentiation.
PMID- 10694928
TI - Anti-neural antibodies in serum and cerebrospinal fluid of amyotrophic lateral
sclerosis (ALS) patients.
AB - OBJECTIVES: An autoimmune basis has been implicated in the pathogenesis of
amyotrophic lateral sclerosis (ALS). This hypothesis is supported by the presence
of antibodies that interact with motoneuron antigens in serum of these patients.
Against autoimmunity are the discrepances in the frequency of the antibodies
appearance and also failure of immunosuppression. The aim of our study was to
evaluate the titer of antibodies against GM1-gangliosides, AGM1-gangliosides and
anti-sulfatides in paired serum and cerebrospinal fluid samples in the ALS
patients. MATERIAL AND METHODS: Serum of 103 and CSF of 79 patients with ALS was
examined. The "disease controls" consisted of 22 cases of other motor neuron
diseases and 50 healthy, age-matched normals. CSF was drawn at the same time from
79 ALS patients, 6 cases of the "disease controls" and 50 normals. To study the
titer of antibodies against GM1-gangliosides, AGM1-gangliosides and sulfatides
the ELISA technique has been applied. RESULTS: An increased titer against GM1
gangliosides, AGM1-gangliosides and sulfatides in ALS appeared in serum in 18%,
32%, and 11%, resp., in the "disease controls" the increased antibodies titer
appeared in single cases. In CSF the appropriate values in ALS were 20%, 15%, 8%,
resp. In the "disease controls" a high antibodies titer was a rare finding.
CONCLUSIONS: It is concluded that in some ALS cases and also in some patients
with other motor neuron diseases an autoimmune mechanism may contribute to motor
neuron injury.
PMID- 10694929
TI - Evidence of 14C-furazolidone metabolite binding to the hepatic DNA of trout.
AB - Furazolidone (FZ) is a nitrofuran drug commonly used in aquaculture. In the
present study, [methylidene-14C]-FZ or [oxazolone-4,5-14C]-FZ was offered to
rainbow trout (Oncorhyncus mykiss) in medicated feed at a daily dose of 135 mg/kg
b. wt. for 10 days. The trout were sacrificed at specific time points post-dosing
and the liver removed for DNA-bound 14C characterization. Both forms of the 14C
labelled FZ were converted by trout to reactive metabolite(s) which bound
irreversibly to the hepatic DNA. The amount of 14C bound to the hepatic DNA
increased with post-dosing time and was higher in trout pretreated with
[methylidene-14C]-FZ than in trout pretreated with [oxazolone-4,5-14C]-FZ. The
identity of the FZ reactive metabolite(s) remained to be elucidated. However, a
part of the FZ reactive metabolite(s) could be released as 3-amino-2-oxazolidone
by acid hydrolysis. An appreciable amount of 14C was also found to bind
irreversibly with the hepatic DNA of trout following an i.v. injection of
[oxazolone-4,5-14C]-FZ. Results of these studies indicate that FZ is metabolized
by trout to a reactive metabolite(s) which binds irreversibly to the DNA of trout
liver.
PMID- 10694930
TI - Induction and inhibition of cytochrome P450-catalysed reduction of biologically
active benfluron N-oxide.
AB - Benfluron N-oxide [5-(2-N-oxo-2-N,N'-dimethylaminoethoxy)-7-oxo-7-H
benzo[c]fluorene] is a biologically active substance which displays a cytostatic
effect on several experimental tumour cells. The main metabolic pathway of
benfluron N-oxide in vitro and in vitro--its reduction to the parent tertiary
amine benfluron--and the role of cytochrome P450 in this reduction were studied.
The value of the benfluron N-oxide/benfluron redox potential as a criterion of
suitability of the substrate for cytochrome P450 reductase activity was
determined. Results of induction and inhibition studies on rats suggest that
cytochromes P4502B and P4502E1 participate in microsomal reduction of benfluron N
oxide. Unlike most cytochrome P450 catalysed reactions, the reduction of
benfluron N-oxide also occurs under aerobic conditions. Microsomes induced by
phenobarbital, ethanol or beta-naphthoflavone showed no significantly greater
inhibitory effect of oxygen on benfluron N-oxide reduction.
PMID- 10694931
TI - Inter-species comparison of microsomal reductive transformation of biologically
active benfluron N-oxide.
AB - Benfluron N-oxide is an anti-neoplastic active metabolite of benfluron (B) /1/.
It is generated by flavine-monooxygenase-catalysed reactions /2/ and immediately
undergoes subsequent metabolic transformations, the most important of which are
reductive reactions /3/. The products of reductive pathways catalysed by two
different microsomal enzymatic systems are the tertiary amine benfluron (i.e. the
original parent compound) and/or 7-dihydrobenfluron N-oxide. Our studies on the
reductive transformation of B N-oxide in rat, mouse, guinea-pig, rabbit, mini-pig
and human microsomes have revealed significant species differences both in the
yields of respective reduced metabolites and in the conditions essential for the
activity of the reductases involved. While B, the original tertiary amine, is the
main product of aerobic incubation of B N-oxide with NADPH in rat, mouse and mini
pig, significantly higher activities of the enzymes catalysing the formation of 7
dihydro-B N-oxide have been detected in rabbit and human microsomes. In rat,
mouse and mini-pig, NADPH rather than NADH is the preferred coenzyme for B
formation, and NADPH is also the preferred coenzyme for the formation of 7
dihydro-B N-oxide in most of the species used. The yield of tertiary amine B is
higher in anaerobic rather than aerobic conditions in most experimental species
studied. Aerobic or anaerobic incubating conditions have an insignificant effect
on the formation of 7-dihydro-B N-oxide. Based on the inhibitory effect of CO on
the reductive transformation of B N-oxide, cytochromes P450 can be assumed to
participate in the formation of B both in rat and mini-pig, and, in mini-pig
only, also in the formation of 7-dihydro-B N-oxide. Inter-species comparison of
the properties of the reductases participating in the transformation of B N-oxide
shows that the rabbit is a suitable model to study reductive transformation of B
N-oxide in man.
PMID- 10694932
TI - Effects of carbamazepine on hepatic glutathione level in rats and determination
of carbamazepine and its epoxide metabolite in plasma by HPLC.
AB - We investigated whether carbamazepine, which is known to be metabolized to an
electrophilic epoxide derivative in the body, causes any decrease, analogous to
the action of epoxides, of hepatic glutathione (GSH) level in rats. Carbamazepine
was administered to rats and liver GSH levels were determined
spectrophotometrically. Neither a single low nor repeated low doses (30 mg/kg) of
carbamazepine (CBZ) produced a statistically significant difference in GSH levels
relative to controls. A single high dose of CBZ (100 mg/kg) produced a large and
significant decrease relative to control (GSH level 3.82 +/- 0.64 vs 6.54 +/-
0.45 mumol GSH/g liver). CBZ and its metabolite carbamazepine-10,11-epoxide were
determined in plasma by HPLC after the high dose of carbamazepine administration.
The concentrations of carbamazepine and carbamazepine-10,11-epoxide were 18.9 +/-
2.9 micrograms/ml and 10.7 +/- 2.8 micrograms/ml, respectively.
PMID- 10694933
TI - Tiagabine: absence of kinetic or dynamic interactions with ethanol.
AB - Tiagabine is a new antiepileptic drug that inhibits the uptake of gamma
aminobutyric acid into neurons and glia. This double-blind, placebo-controlled
study investigated the effect of multiple doses of tiagabine on the adverse
cognitive effects produced by a single dose of ethanol in 20 healthy volunteers.
The effects of each drug on the pharmaco-kinetics of the other were also
determined. Compared with placebo, tiagabine produced no statistically
significant effects on digit vigilance speed (primary assessment variable) or
accuracy, choice reaction time, immediate or delayed word recall, delayed word
recognition speed or sensitivity, visual tracking, body sway, or subjective
measures of alertness, calmness, and contentment. There was no evidence of a
pharmacodynamic interaction between tiagabine and ethanol with respect to these
variables. The pharmacokinetic parameters of tiagabine and ethanol (maximum
plasma concentration [Cmax], time to Cmax and area under the plasma concentration
time curve) were unchanged during concomitant administration. Adverse events,
which mainly affected the central nervous system, occurred with a similar
incidence during tiagabine and placebo administration and were more common after
the administration of ethanol. There appears to be no need for additional caution
regarding driving or operating machinery when ethanol is administered to patients
taking tiagabine.
PMID- 10694934
TI - Cadherin adhesion in the intestinal crypt regulates morphogenesis, mitogenesis,
motogenesis, and metaplasia formation.
AB - The topographical organisation of the epithelium lining mucous membranes has been
an intense point of research. One of the fundamental biological issues
underpinning this and associated issues relates to the role and regulation of
epithelial adhesion molecules. Adhesion between individual cells allows an intact
layer to be formed, which is selectively permeable. In addition, the orchestrated
regulation of multiple adhesion molecules allows the gradual transition from
basal secretory cells to apical absorptive cells in the crypt-villus gradient.
Moreover, it is becoming clear that no one class of adhesion molecule can
sufficiently govern crypt architecture; however, the main cell-cell adhesion
molecules are the cadherins and the related desmosomal cadherins. These latter
molecules interact with the catenins, which bind directly or indirectly with
cytoskeletal molecules such as Rho and Rac. In addition, other complex
glycoproteins, such as the carcinoembryonic antigens, might contribute to
adhesion, although their mechanisms of function are distinctly different.
Integrins on the basal aspect of the cells also signal important morphoregulatory
signals as a result of their binding to the extracellular maxtrix. The disruption
of these physiological processes also provides a necessary and, in some cases,
sufficient molecular mechanism for cancer invasion and metastasis, such as occurs
in E-cadherin mutation positive familial gastric cancer.
PMID- 10694935
TI - The adenomatous polyposis coli protein.
AB - Mutations in the adenomatous polyposis coli (APC) gene are associated with most
colorectal cancers. The APC protein has been implicated in many aspects of tumour
development. This article will discuss recent data suggesting that APC may have
multiple functions in the cell. First, APC is a component of the Wnt signalling
pathway; second, APC may have a role in cell migration; finally, APC may regulate
proliferation and apoptosis.
PMID- 10694936
TI - Lewis blood group and CEA related antigens; coexpressed cell-cell adhesion
molecules with roles in the biological progression and dissemination of tumours.
AB - The Lewis blood group and carcinoembryonic antigen (CEA) related antigens have
adhesive functions in human tissues, with roles in embryonic sorting and
migration of cells (organogenesis), differentiation and protection of normal
mucosal tissues, migration of neutrophils, bacterial binding, and tumour
differentiation and dissemination. In the key areas of mucosal protection,
neutrophil binding, and tumour metastasis, they are often coexpressed on the
outer cell membrane, with Lewis blood group antigens forming the terminal
carbohydrate chains on a CEA related glycoprotein backbone. The central role of
these antigens in the mechanism of neutrophil binding to endothelium in
inflammation highlights a fascinating paradigm for tumour cell dissemination and
metastasis, and expression is linked to disease prognosis. This review outlines
the structure, function, and comparative roles of these antigens in human
tissues.
PMID- 10694937
TI - Regulation of E-cadherin: does hypoxia initiate the metastatic cascade?
AB - The ability of tumours to metastasis is regarded as one of the hallmarks of
malignancy. The process through which tumours evolve to achieve this has been
termed the metastatic cascade. This cascade has been the subject of much
investigation over many years. One of the vital events identified by these
investigations is the reduction of adhesion between tumour cells facilitating
invasion of the surrounding tissues and vascular channels, ultimately leading to
the development of a distant metastasis. E-cadherin and its associated catenin
complex have been identified as key molecules in cell adhesion. This review looks
at the structure and interaction of the E-cadherin-catenin complex and the
factors that appear to regulate E-cadherin expression and thus cell adhesion.
From the data gathered, it has become possible to propose the hypothesis that the
development of tumour hypoxia is the initiating factor that sets the tumour on
the road to metastasis.
PMID- 10694938
TI - CD44 cell adhesion molecules.
AB - The CD44 proteins form a ubiquitously expressed family of cell surface adhesion
molecules involved in cell-cell and cell-matrix interactions. The multiple
protein isoforms are encoded by a single gene by alternative splicing and are
further modified by a range of post-translational modifications. CD44 proteins
are single chain molecules comprising an N-terminal extracellular domain, a
membrane proximal region, a transmembrane domain, and a cytoplasmic tail. The
CD44 gene has only been detected in higher organisms and the amino acid sequence
of most of the molecule is highly conserved between mammalian species. The
principal ligand of CD44 is hyaluronic acid, an integral component of the
extracellular matrix. Other CD44 ligands include osteopontin, serglycin,
collagens, fibronectin, and laminin. The major physiological role of CD44 is to
maintain organ and tissue structure via cell-cell and cell-matrix adhesion, but
certain variant isoforms can also mediate lymphocyte activation and homing, and
the presentation of chemical factors and hormones. Increased interest has been
directed at the characterisation of this molecule since it was observed that
expression of multiple CD44 isoforms is greatly upregulated in neoplasia. CD44,
particularly its variants, may be useful as a diagnostic or prognostic marker of
malignancy and, in at least some human cancers, it may be a potential target for
cancer therapy. This review describes the structure of the CD44 gene and
discusses some of its roles in physiological and pathological processes.
PMID- 10694939
TI - Small GTPases and regulation of cadherin dependent cell-cell adhesion.
AB - Cadherins belong to a superfamily of cell-cell adhesion receptors that bind to
the same type of molecules (homotypic interaction) in a calcium dependent manner.
Different members of the family are found in a wide variety of cell types and
cadherin adhesive function plays a role in cell fate, segregation, and
differentiation, which ensures the higher order of organisation found in many
tissues. This review will focus on the role that cadherin adhesiveness plays in
the differentiation of epithelial cells, and how cadherin function can be
regulated by proteins of the small GTPase family. In the text, readers are
referred to recent reviews and other chapters covering important topics that are
not discussed here because of space limitation.
PMID- 10694940
TI - Alpha E beta 7.
AB - alpha E beta 7 is a member of the integrin family and is expressed almost
exclusively by cells of the T lymphocyte lineage in mucosal tissues. Expression
is induced by transforming growth factor beta in the mucosal microenvironment.
Genetic elements that control transcription are under investigation and may prove
valuable for directing the expression of transgenes in mucosal T cells. The only
known ligand for alpha E beta 7 is E-cadherin, which is expressed on epithelial
cells. In this article, molecular aspects of ligand recognition by alpha E beta 7
in relation to recent structural data on cadherin domains are reviewed.
Expression of alpha E beta 7 is often increased in inflammatory diseases,
particularly where T cells infiltrate epithelial tissues. The function of alpha E
beta 7 is not yet fully understood, but it is likely to be important in retention
of T cells in mucosal tissues and may also have a role in cell signalling and
communication between lymphocytes and epithelial surfaces.
PMID- 10694941
TI - Integrins: a role as cell signalling molecules.
AB - Integrins form the major family of proteins that mediates cell-matrix
interactions. As well as an adhesive function, it is increasingly apparent that
integrins can transduce messages via classic signalling pathways and impact upon
such fundamental cellular processes as proliferation, apoptosis, differentiation,
and motility. Dysregulation of these processes are a feature of many
malignancies. Altered integrin expression has been observed in many human
tumours, and perturbation of integrin function or expression in experimental
systems has demonstrated that altered integrin signalling may directly contribute
to the development of the malignant phenotype.
PMID- 10694942
TI - Adhesion of lymphocytes to hepatic endothelium.
AB - Chronic inflammation occurs when factors that regulate the process of leucocyte
recruitment are disrupted, and it is dependent on recruitment, activation, and
retention of lymphocytes within tissue microenvironments. The molecular
mechanisms that mediate lymphocyte adhesion to vascular endothelial cells have
been described by several groups, but the signals involved in the recruitment of
lymphocytes via the hepatic circulation have yet to be elucidated fully. This
article considers the liver as a model of organ specific lymphocyte recruitment.
In this context, the roles of leucocyte and endothelial adhesion molecules and
chemokines in lymphocyte recruitment are discussed. The article also reviews the
mechanisms that regulate lymphocyte recirculation to the liver under both
physiological and pathological conditions and draws parallels with other organs
such as the gut and skin.
PMID- 10694943
TI - Cell adhesion molecules in the pathogenesis of and host defence against microbial
infection.
AB - Eukaryotic cell adhesion molecules (CAMs) are used by various cells and
extracellular molecules in host defence against infection. They are involved in
many processes including recognition by circulating phagocytes of a site of
inflammation, transmigration through the endothelial barrier, diapedesis through
basement membrane and extracellular matrix, and release of effector mechanisms at
the infected site. CAMs involved in leucocyte-endothelial cell interaction
include the selectins, integrins, and members of the immunoglobulin superfamily.
However, CAMs are also used by various microorganisms (protozoa, fungi, bacteria,
and viruses) during their pathogenesis. For example, bacteria that utilise CAMs
include Mycobacterium tuberculosis, Listeria monocytogenes, Yersinia spp,
enteropathogenic Escherichia coli, Shigella spp, Neisseria spp, Bordetella spp,
and Borrelia burgdorferi. In addition, CAMs are involved in the pathogenetic
effects of the RTX toxins of Pasteurella haemolytica, Actinobacillus
actinomycetemcomitans, and the superantigen exotoxins of Staphylococcus aureus
and Streptococcus pyogenes. A recurrent and topical theme of potential importance
within the bacterial group is the intimate relation between CAMs, bacterial
protein receptors, and type III secretion systems. For example, the IpaBCD
protein complex is secreted by the type III system of Shigella flexneri and
interacts with alpha 5 beta 1 integrin on the eukaryotic cell surface, followed
by Rho mediated internalisation; this illustrates the relevance of cellular
microbiology. CAMs might prove to be novel therapeutic targets. Comparative
genomics has provided the knowledge of shared virulence determinants among
diverse bacterial genera, and will continue to deepen our understanding of
microbial pathogenesis, particularly in the context of the interaction of
prokaryotic and eukaryotic molecules.
PMID- 10694944
TI - A colorectal cell line with alterations in E-cadherin and epithelial biology may
be an in vitro model of colitis.
AB - BACKGROUND: It has been shown previously in ulcerative colitis tissue that E
cadherin can occasionally be mutated in the extracellular domain early in
neoplastic progression. E-cadherin is known to maintain differentiation and
inhibits invasion in vivo. AIMS: To assess the mechanisms by which such
dysfunction occurs. METHODS: Four human colorectal cancer cell lines, HCA-7
colonies 1, 3, 6, and 30, derived from a single heterogeneous colorectal cancer
were studied. The HCA-7 cell line has p53 mutations and a random errors of
replication "positive" phenotype, as is seen in early colitis associated cancers
or hereditary nonpolyposis coli cancer (HNPCC). RESULTS: Cell lines 6 and 30
expressed E-cadherin abundantly and this correlated positively with their degree
of differentiation and organisation; however, both cell lines had loss of
heterozygosity of E-cadherin. Interestingly, E-cadherin production was
downregulated in the poorly differentiated cell line 1, and this was associated
with major chromosomal rearrangements of 16q. This cell line also had a mutation
in the homophilic binding domain of exon 4, which was associated with
disaggregation by low titres of a function blocking antibody, and an invasive
phenotype. CONCLUSIONS: These multiple biological alterations further
characterise the complex association that E-cadherin has with tumour
heterogeneity and suggest that this series of cell lines may be a useful model of
colitis associated or HNPCC associated tumorigenesis.
PMID- 10694945
TI - Prevention and treatment of chemotherapy- and radiotherapy-induced oral
mucositis: a review.
AB - Oral mucositis is a distressing toxic effect of systemic chemotherapy with many
commonly utilized drugs and of head and neck irradiation in patients with cancer.
The agents and methods that have been used and studied in chemotherapy- and
radiotherapy-induced oral mucositis, their mechanisms of action, and the current
knowledge of their efficiency to reduce the incidence, severity or shorten the
duration of oral mucositis are reviewed in this article. Oral cooling is a cheap
and available method to lower the severity of bolus 5-fluorouracil-induced oral
mucositis. However, more effective methods are needed. Results of studies with
granulocyte-macrophage colony-stimulating factor or granulocyte colony
stimulating factor are promising. Lasers are partly beneficial, but equipment
demanding. Modification of the chemotherapy regimen resulting in shortening of
the exposition time to chemotherapy agents or chronomodulation of chemotherapy
has been shown to lower mucosal toxicity of some regimens. Results of animal
studies with locally applied transforming growth factor beta 3 and interleukin-11
are also promising. Based on the findings of the role of the inflammatory cascade
in the response of normal tissues to chemotherapy and radiotherapy, anti
inflammatory drugs might be beneficial. At the present time, no agent has been
shown to be uniformly efficacious and can be accepted as standard therapy of
chemotherapy- and radiotherapy-induced oral mucositis. Further intensive research
is needed.
PMID- 10694946
TI - Cancer of mouth, pharynx and nasopharynx in Asian and Chinese immigrants resident
in Thames regions.
AB - Studies on migrants can generate important clues on the etiology of cancer. The
purpose of the present study was to determine the relationship between ethnic
origin and the incidence of oral and pharyngeal cancers among residents of the
Thames regions in southern England. Records from the Thames Cancer Registry
during the period 1986-91 were examined and south Asians and Chinese ethnic
immigrants flagged using their place of birth and names. Computation of relative
incidence among head and neck cancers (n = 7222) showed that oral cancer was
significantly higher among Asians (95/232 = 40.9%) and nasopharyngeal cancer
among Chinese (45/67 = 67.2%). Some differences in the intra-oral site of cancer
and ethnic origin were noted. The ethnic migrants were significantly younger
(Asians 51.6 +/- 34.8 years, Chinese 47.6 +/- 14.8 years) compared to the rest of
the population (64.8 +/- 15.6 years) at the time of cancer diagnosis (p = 0.0)
but no significant differences were found for the stage of presentation. The mean
survival period for a cancer of the head and neck was 2.2 years and significant
differences in cumulative rates of survival were noted among the three groups
studied (p = 0.003). A strong correlation was noted between the incidence of oral
cancer and local authorities with a high percentage of Asian residents. The south
Asian and Chinese ethnic minorities constitute important high risk groups for
oral and nasopharyngeal cancer, for whom targeted prevention is indicated.
PMID- 10694947
TI - Inactivation patterns of the p16 (INK4a) gene in oral squamous cell carcinoma
cell lines.
AB - To determine whether inactivation of the p16 gene mapped to the chromosome 9p21
region is associated with the development of oral squamous cell carcinoma (SCC),
we investigated the mutational states of two forms of alternative transcripts
(alpha and beta) from the p16 gene in 14 oral SCC cell lines by means of RT-PCR,
PCR, direct sequencing and methylation analyses. Alterations of the alpha
transcript were detected in all of the cell lines examined: homozygous deletions
in three lines; subtle mutations in exons 1 alpha or 2 in four lines; skipping of
exon 2 in two lines; hypermethylation of the 5' CpG island of the p16 gene in
four lines; and an unknown mechanism in one line. On the other hand,
abnormalities of the beta transcript were observed in seven of the 14 cell lines.
Nonetheless, the mutations that essentially affect the function of the encoded
protein were found only in five cell lines, including three lines with homozygous
deletion. There was no cell line having only beta transcript alterations. Thus,
alteration of the alpha transcript of the p16 gene was a highly frequent event in
oral SCC. Since this type of alteration resulted in gene inactivation through
multiple pathways, it may play a major role in the process of oral SCC
development.
PMID- 10694948
TI - Prognostic importance of the expression of CD44 splice variants in oral squamous
cell carcinomas.
AB - Considering squamous cell carcinomas (SCCs) of the oral cavity and oropharynx the
molecular mechanisms underlying the infiltration and destruction of adjacent
tissue as well as the metastatic spread are largely unknown. In this context, the
detection of defective expression of cellular adhesion molecules in the tumour
cells, e.g. CD44, might be important and correlated with prognosis. Paraffin
embedded tumour-tissue from 99 patients with primary oral and oropharyngeal SCC,
additionally including corresponding lymph-node metastases in nine cases, was
analysed for expression of the CD44 splice variants v4, v5, v6, v7, and v9 by
means of immunohistochemistry. A diminution of at least one of the examined CD44
isoforms compared to the normal oral epithelium was observed in 39.4% of the
squamous cell carcinomas. No correlations could be found between CD44 expression
and pT- or pN-stage. However, decreased expression of v9 was correlated with
higher histological grade (p < 0.001). Moreover, reduced CD44 expression was a
statistically significant independent predictor for shorter survival time (p =
0.002) as well as shorter recurrence-free interval (p = 0.004) in addition to pT-
and pN-stage. The separate analysis showed that particularly the decreased v7 (p
= 0.04) and v9 (p < 0.02) expression in the tumour cells was associated
negatively with survival.
PMID- 10694949
TI - Carbon dioxide laser evaporation of leukoplakia of the lower lip: a retrospective
evaluation.
AB - The purpose of this study was the retrospective evaluation of the treatment
results of CO2 laser evaporation for 27 cases of leukoplakia of the lip. The data
were derived from 23 patients who presented with leukoplakia of the lower lip
during the period 1978-96. Four patients developed a second primary leukoplakia
of the lip resulting in 27 cases of leukoplakia. All lesions were treated with a
CO2 laser equipped with an operation microscope and micromanipulator. Short-term
evaluation showed complete epithelialisation 4 weeks after CO2 laser evaporation;
there was minimal scar formation and no subsequent interference with normal lip
function. During long-term evaluation, four recurrences (14.8%) were diagnosed
which developed between 5 and 31 months after treatment, these were retreated
with CO2 laser evaporation. There was no development of squamous cell carcinoma
in the CO2 laser-treated area. Selective removal of affected epithelium with
minimal damage to surrounding structures is possible using CO2 laser evaporation,
followed by excellent wound healing and good functional result. Treatment can be
performed under local anaesthesia on an outpatient basis. The recurrence rate is
low compared with the recurrence rate after surgical excision. Therefore, CO2
laser evaporation is considered a reliable and effective treatment modality for
leukoplakia of the lip.
PMID- 10694950
TI - Eosinophil ablation and tumor development.
AB - Tissue eosinophilia in squamous cell carcinoma has long been recognized; however,
the role of eosinophils in tumor development remains unclear. Studies have
reported both favorable and unfavorable prognoses for patients with tumors
exhibiting tumor-associated tissue eosinophilia (TATE). This study seeks to
elucidate the potential role of the eosinophil in squamous cell carcinoma
development and provide an experimental model for future studies. The carcinogen
induced hamster oral cancer model was found to fulfill these objectives.
Eosinophils progressively infiltrate into this carcinogen-induced oral cancer
model. We now demonstrate that TATE is completely abolished by the use of an anti
interleukin-5 monoclonal antibody (mAb) preparation, TRFK-5. Clinical
observations revealed that TRFK-5-treated hamsters exhibited smaller tumor burden
and delayed onset of tumor development. The results suggest that anti-interleukin
5 antibody treatment may delay and/or inhibit tumor development, and that
eosinophils may have a tumor-promoting role.
PMID- 10694951
TI - Prognostic significance of proliferative and apoptotic markers in oral tongue
squamous cell carcinomas.
AB - The prognostic impact of proliferative and apoptotic markers was studied in 85 T1
4 oral tongue squamous cell carcinomas (SCCs). Ki67 immunoreactivity and AgNOR
counts, including mean AgNOR counts (mAgNOR) and the percentage of nuclei with
more than one AgNOR (pAgNOR > 1), were used as proliferative parameters. The
apoptotic index (AI) was assessed using the TUNEL method. Bax expression was
detected immunohistochemically and scored. Bax expression correlated positively
with AI (p = 0.0122). Ki67 correlated with both pAgNOR > 1 (p = 0.0042) and
mAgNOR (p = 0.0189). Low Bax expression and low AI correlated significantly with
the disease-free period (p = 0.0001 and p = 0.0024, respectively). High values
for Ki67, pAgNOR > 1 and mAgNOR correlated with poor prognosis (p = 0.0021, p =
0.0001 and p = 0.0244, respectively). Combinations of proliferative and apoptotic
parameters were stronger predictors than individual parameters (p < 0.0001).
pAgNOR > 1-Bax expression appeared to be the best combination (p < 0.0001). We
conclude that proliferative and apoptotic markers, especially their combinations,
have prognostic value in tongue SCC.
PMID- 10694952
TI - Evaluation of telomerase activation in head and neck cancer.
AB - During replication of the linear chromosomes, telomeres, i.e. the ends of the
chromosomes, are not replicated completely by the conventional DNA polymerases.
Therefore, normal somatic cells senesce after certain number of cell divisions.
Telomerase is a special reverse transcriptase used by most eukaryotes to achieve
immortalization. Telomerase activity has been determined in a variety of cancers.
However, there are few reports on telomerase activity in head and neck cancer.
The etiology of the disease in India is completely different from Western
countries. Tobacco consumption is more prevalent in India and the mode of tobacco
consumption (e.g. chewing, snuffing, bidi smoking, reverse smoking) is also
different. The present study determined telomerase activity in 32 malignant
tumour samples of head and neck cancer patients, 11 samples from patients with
precancerous/benign lesions and 30 samples of adjacent normal tissues. Telomerase
was found to be activated in 80% of the patients with head and neck cancer, 100%
of the patients with precancerous/benign lesions and 74% of the adjacent normal
tissues. According to the theory of field cancerization, carcinogenic insults
(e.g. tobacco) may result into multiple malignant foci. This fact may explain the
reason for high telomerase positivity in adjacent normal as well as
precancerous/benign tissues. Telomerase activation and the clinical or
histopathological characteristics of the head and neck cancer patients were
observed to be independent features. This is a preliminary report which has
generated a greater interest for in-depth elucidation of the role of telomerase
and telomeres in head and neck carcinogenesis in India.
PMID- 10694953
TI - Differential DNA methylation of the p16 INK4A/CDKN2A promoter in human oral
cancer cells and normal human oral keratinocytes.
AB - The p16 INK4A tumor suppressor gene participates in establishing and maintaining
the malignant phenotype of a variety of cancer cell lines and primary tumors.
Recently it has been observed that p16 expression is lost in oral cavity cancer
cell lines in the presence of a normal intact gene. To examine the role of DNA
methylation as an explanation for these findings, we analyzed the DNA methylation
patterns of the p16 INK4A promoter in DNA isolated from primary cultures of
normal human oral keratinocytes and squamous cell carcinoma (SCC-15) oral cancer
cells using bisulfite genomic sequencing. Our results demonstrated striking
differences in the methylation status of the 5' CpG island of the p16 gene
between normal and cancer cells. Normal human oral keratinocytes showed
practically no methylation of the p16 INK4A promoter, while SCC-15 oral cancer
cells showed almost complete methylation in this region. These data implicate DNA
methylation as a mechanism for transcriptional silencing of the p16 INK4A gene in
oral cancer cells.
PMID- 10694954
TI - Effects of bisphosphonate on experimental jaw metastasis model in nude mice.
AB - The mechanism of osteolysis associated with metastatic cancer of the jaws is
essentially osteoclast-mediated. Therefore, it is likely that potent osteoclastic
bone resorption inhibitors such as bisphosphonates would be efficacious for the
treatment of jaw metastasis. We examined the effects of a third generation
bisphosphonate, YM175, in a nude mice jaw metastasis model with intracardiac
injection of a human breast cancer cell line, MDA-MB-231. The metastatic lesions
in untreated mice were radiographically observed at the body and angle of the
mandible. Histology of the mandible of untreated mice revealed that most of the
bone marrow cavities had been occupied by the metastatic tumor with active
osteoclasts along the trabecular bone. The experimental group showed that YM175
markedly reduced the size of tumor and the number of osteoclasts. These results
suggest that YM175 may suppress metastasis formation and tumor growth in jaw
through inhibition of osteoclastic bone resorption.
PMID- 10694955
TI - Well-differentiated intraosseous osteosarcoma of the jaws: experience of two
cases from the Instituto Nacional de Cancerologia, Mexico.
AB - Osteosarcomas of the jaws represent less than 10% of all osteosarcomas, and most
of them are high-grade neoplasms. Prognostic factors in overall survival include
tumor size, location and histologic grade. Examples of well-differentiated (low
grade) intraosseous osteosarcomas of the jaws (WDIOJ) have been rarely reported.
This article presents two cases of this unusual lesion, one of which was located
in the maxilla of a 17-year-old man and the other developed in the mandible of a
37-year-old woman. CT scan was necessary to detect the small foci of penetration
into the thinned cortical bone and the reactive periosteal bone formation, which
are important findings to establish the correct diagnosis of WDIOJ and help to
exclude other benign intraosseous lesions that may be very similar
histologically, such as fibrous dysplasia, ossifying and desmoplastic fibromas.
In spite of tumor size (mean 5.2 cm), their well-demarcated borders allowed
complete removal of both tumors. There is no evidence of tumoral activity in any
of our patients after follow-up periods of 15 months and 5 years. Wide excision
seems to be the treatment of choice for this subgroup of osteosarcomas.
PMID- 10694956
TI - The rise and fall of a theory of vision--Hecht's photochemical doctrine.
PMID- 10694957
TI - Gorillas in our midst: sustained inattentional blindness for dynamic events.
AB - With each eye fixation, we experience a richly detailed visual world. Yet recent
work on visual integration and change direction reveals that we are surprisingly
unaware of the details of our environment from one view to the next: we often do
not detect large changes to objects and scenes ('change blindness'). Furthermore,
without attention, we may not even perceive objects ('inattentional blindness').
Taken together, these findings suggest that we perceive and remember only those
objects and details that receive focused attention. In this paper, we briefly
review and discuss evidence for these cognitive forms of 'blindness'. We then
present a new study that builds on classic studies of divided visual attention to
examine inattentional blindness for complex objects and events in dynamic scenes.
Our results suggest that the likelihood of noticing an unexpected object depends
on the similarity of that object to other objects in the display and on how
difficult the priming monitoring task is. Interestingly, spatial proximity of the
critical unattended object to attended locations does not appear to affect
detection, suggesting that observers attend to objects and events, not spatial
positions. We discuss the implications of these results for visual
representations and awareness of our visual environment.
PMID- 10694958
TI - Driving experience and the functional field of view.
AB - Research has suggested that novice drivers have different search strategies
compared with their more experienced counterparts, and that this may contribute
to their increased accident liability. One issue of concern is whether
experienced drivers have a wider field of peripheral vision than less experienced
drivers. This study attempted to distinguish between people of varying driving
experience on the basis of their functional fields of view. Participants searched
video clips taken from a moving driver's perspective for potential hazards while
responding to peripheral target lights. Hit rates for peripheral targets
decreased for all participant groups as processing demands increased (i.e. when
hazards occurred) and as the eccentricity of the target increased, though there
was no interaction. An effect of experience was also found which suggests that
this paradigm measures a perceptual skill or strategy that develops with driving
experience.
PMID- 10694959
TI - Temporal constraints on visual learning: a computational model.
AB - Given a constant stream of perceptual stimuli, how can the underlying invariances
associated with a given input be learned? One approach consists of using generic
truths about the spatiotemporal structure of the physical world as constraints on
the types of quantities learned. The learning methodology employed here embodies
one such truth: that perceptually salient properties (such as stereo disparity)
tend to vary smoothly over time. Unfortunately, the units of an artificial neural
network tend to encode superficial image properties, such as individual grey
level pixel values, which vary rapidly over time. However, if the states of units
are constrained to vary slowly, then the network is forced to learn a smoothly
varying function of the training data. We implemented this temporal-smoothness
constraint in a backpropagation network which learned stereo disparity from
random-dot stereograms. Temporal smoothness was formalized with the use of
regularization theory by modifying the standard cost function minimised during
training of a network. Temporal smoothness was found to be similar to other
techniques for improving generalisation, such as early stopping and weight decay.
However, in contrast to these, the theoretical underpinnings of temporal
smoothing are intimately related to fundamental characteristics of the physical
world. Results are discussed in terms of regularization theory and the physically
realistic assumptions upon which temporal smoothing is based.
PMID- 10694960
TI - Do 9-month-olds perceive causation-at-a-distance?
AB - Humans understand mechanical events to involve physical bodies interacting by
contact, but intentional events involve agents that can also interact at a
distance. We investigated infant sensitivity to causality in a simple event in
which one agent appears to react to another without contact. Infants 9 months old
were habituated to one of two events involving a computer-animated red square
moving nonrigidly--like a caterpillar--towards a green square. In the 'reaction
event', the green object moved in turn before the red one stopped, while in the
'pause event' the green object moved after the red one stopped. After
habituation, each infant saw the habituation movie played in reverse. This test
involved identical spatiotemporal changes for reaction and pause event, but the
reversed reaction additionally involved a change in the causal roles. Infants
dishabituated to reversal of the reaction but not the pause event, a result which
suggests sensitivity to causation-at-a-distance. This ability could support
development of social cognition and theory of mind.
PMID- 10694961
TI - Fooling the eyes: trompe l'oeil and reverse perspective.
AB - Trompe l'oeil pictures have been produced for hundreds of years. They attempt to
create the impression of a surface that has different three-dimensional structure
to the work; successful examples of trompe l'oeil typically constrain the
observer's viewpoint and require use of a single eye. The works of Patrick Hughes
are in relief but are painted to appear like conventional flat pictures; those
parts that protrude from the picture plane are pictorially distant, or in reverse
perspective. Movements of the observer result in fluid distortions of the
pictorial image. These distortions occur with binocular observation and over a
wide range of viewing distances.
PMID- 10694962
TI - An analysis of binocular slant contrast.
AB - When a small frontoparallel surface (a test strip) is surrounded by a larger
slanted surface (an inducer), the test strip is perceived as slanted in the
direction opposite to the inducer. This has been called the depth-contrast
effect, but we call it the slant-contrast effect. In nearly all demonstrations of
this effect, the inducer's slant is specified by stereoscopic signals; and other
signals, such as the texture gradient, specify that it is frontoparallel. We
present a theory of slant estimation that determines surface slant via linear
combination of various slant estimators; the weight of each estimator is
proportional to its reliability. The theory explains slant contrast because the
absolute slant of the inducer and the relative slant between test strip and
inducer are both estimated with greater reliability than the absolute slant of
the test strip. The theory predicts that slant contrast will be eliminated if the
signals specifying the inducer's slant are consistent with one another. It also
predicts reversed slant contrast if the inducer's slant is specified by
nonstereoscopic signals rather than by stereo signals. These predictions were
tested and confirmed in three experiments. The first showed that slant contrast
is greatly reduced when the stereo-specified and nonstereo-specified slants of
the inducer are made consistent with one another. The second showed that slant
contrast is eliminated altogether when the stimulus consists of real planes
rather than images on a display screen. The third showed that slant contrast is
reversed when the nonstereo-specified slant of the inducer varies and the stereo
specified slant is zero. We conclude that slant contrast is a byproduct of the
visual system's reconciliation of conflicting information while it attempts to
determine surface slant.
PMID- 10694963
TI - Test of Petter's rule for perceived surface stratification.
AB - Petter's rule applies to two-dimensional patterns formed by two overlapping
surfaces that alternatively appear in front of one another. It states that the
surface with the shorter contours in the region where the surfaces look
superimposed has a greater probability of appearing in front of the other
surface. An experiment is reported the results of which show that Petter's rule
is valid for chromatically homogeneous and for uniformly dense dotted patterns,
and invalid for different kinds of chromatically inhomogeneous patterns. Petter's
rule has been found to be valid when the overlapping surfaces have contours with
gaps. It is proposed that Petter's rule derives from the dynamics of filling-in
of contour gaps.
PMID- 10694964
TI - Aftereffects and the representation of stereoscopic surfaces.
AB - The structure of human disparity representation is examined through (i)
adaptation experiments and (ii) model simulations of the data. Section 3 presents
results of adaptation experiments designed to illuminate the structure of human
disparity representation. Section 4 presents model simulations of three different
disparity representation schemes. In the experiments, participants adapted to a
0.133 cycle deg-1 sinusoidally corrugated surface with 10 min of arc peak-to
trough disparity. A flat test surface was briefly presented, in which the
aftereffect surface was perceived. Adapt and test surfaces were placed on
disparity pedestals and thus presented in front of or behind the plane of
fixation. The adapt surface could be offset from the fixation plane by +/- 8 to
24 min of arc. The test surface could be offset from the fixation plane by +/- 8
to 48 min of arc. The depth aftereffect was measured in different disparity
planes by a nulling method and 'topping-up' procedure. Aftereffect tuning
functions were obtained whose bandwidths, magnitudes, and tuning depended on the
disparity planes of both the adapt and test surfaces. These parameters were used
to constrain the models tested in section 4. On the basis of the two studies, it
is argued that the human stereoscopic system encodes spatial changes of disparity
using channels localised within disparity planes. A localised disparity-gradient
model of the human representation of disparity is proposed.
PMID- 10694965
TI - Matching person identity from facial line drawings.
AB - The processing of facial line drawings was investigated in either simultaneous or
sequential matching trials with either the same or different viewpoint, showing
pictures of faces either in the same modes (both photographs or line drawings) or
different modes (one in each mode). Line drawings were particularly difficult to
match in memory rather than under perceptual conditions, and line drawings did
not allow the creation of efficient structural codes. These deficits of line
representations underline the assumption that the face-processing system is
inflexible when it is confronted with edge-based material.
PMID- 10694966
TI - Brain scanning and the single mind.
PMID- 10694967
TI - Differences in top-down influences on the reversal rate of different categories
of reversible figures.
AB - Understanding the mechanisms underlying the multistability of reversible figures
may provide valuable insights into the normal functioning of our visual system.
The proposed factors that control the perceptual alternations of reversible
figures can be classified into bottom-up and top-down processes. In the present
study, we report differences in top-down effects on the reversal rate depending
on whether a structural perspective (Necker cube, Schroder staircase) or a
meaningful content (duck/rabbit figure, chef/dog figure) is subject to the
reversal phenomenon. In order to activate top-down mechanisms explicitly the
subjects had the instruction to bring the reversal rate under voluntary control.
The results indicated that both slowing down and speeding up the rate of
alternations was more effective for the content-reversal figures (duck/rabbit,
chef/dog) than for the rather abstract perspective-reversal figures (Necker cube,
Schroder staircase). In order to investigate the effect of meaningfulness in
figure/ground reversals, the effect of the same instructional variable was also
determined for Rubin's vase/faces and the Maltese cross. The results showed a
similar tendency as in the case of the comparison between perspective reversals
and content reversals. Possible cognitive processes that may play a role in top
down influences on figure reversal and theoretical implications of these findings
for the interaction of bottom-up and top-down processes are discussed.
PMID- 10694968
TI - Recognizing silhouettes and shaded images across depth rotation.
AB - Outline-shape information may be particularly important in the recognition of
depth-rotated objects because it provides a coarse shape description which gives
first-pass information about the structure of an object. In four experiments, we
compared recognition of silhouettes (showing only outline shape) with recognition
of fully shaded images of objects, by means of a sequential-matching task. In
experiments 1 and 2, the first stimulus was always a shaded image, and the second
stimulus was either a shaded image or a silhouette. Recognition costs associated
with a change in viewpoint were no greater for silhouettes than they were for
shaded images. Experiments 3 and 4 replicated the design of the earlier
experiments, but showed a silhouette as the initial stimulus, rather than a
shaded image. In these cases, recognition costs associated with a change in
viewpoint were greater for silhouettes than for shaded images. Combined, these
results indicate that, while visual representations clearly include additional
information, outline shape plays an important role in object recognition across
depth rotation.
PMID- 10694969
TI - Effects of face configuration change on shape perception: a new illusion.
AB - We report two experiments indicating that varying the configuration of face
features changes perception of an oval aperture windowing the face: as the eyes
and mouth of a frontal-view face photograph are moved vertically toward face
boundaries, the oval appears increasingly clongated, taller, and narrower; when
eyes and mouth are moved toward the nose, the oval appears increasingly rounder,
shorter, and wider. This shape illusion is maximised when faces appear upright
within the oval and major face features (eyes, nose, and mouth) appear in their
correct relative locations. These results establish that processing of a face
configuration can affect perception of a geometric shape that shares visual space
with a face. Whether the illusion is face-specific or a special case of a more
general geometric illusion is discussed.
PMID- 10694970
TI - Thompson's Margaret Thatcher illusion: when inversion fails.
AB - It is argued that the whole face is more dominant than the individual features.
In the case of a jumbled face the external pattern is dominant when a face is
upright, whereas the internal pattern is dominant when a face is inverted.
PMID- 10694971
TI - Wakes and spokes: new motion-induced brightness illusions.
AB - Under certain conditions, high-contrast moving figures induce adjacent illusory
regions, 'wakes' and 'spokes', which have contrast polarity opposite the inducing
figures. In this paper we document properties of these novel phenomena. When the
illusions are induced by a moving bar, spokes appear on the side of the bar
closer to fixation and connect the bar to the fixation point, regardless of the
momentary position of the bar or whether it is moving to the left or to the
right. Although spokes often extend up to the fixation point, they never extend
beyond it. This is not due to blocking of the spoke's spread by the fixation
point, because in another experiment spokes extend directly through an
intervening figure. Whereas spokes emanate from the end of a horizontally moving
bar closest to fixation, wakes emanate from the end farthest from fixation. In
contrast to spokes, wakes do not show a towards-fixation bias. Instead, the
wake's end trails the position of the bar, like a ship's wake. The higher the bar
velocity, the more the end of the wake appears to trail it, suggesting that wakes
are caused by a process which spreads from the edge of moving figures. Wakes and
spokes, as distinct illusions, should provide significant constraints on theories
of human motion and brightness perception processes.
PMID- 10694972
TI - Motion parallel to line orientation: disambiguation of motion percepts.
AB - Four experiments demonstrate that lines indicating path of movement can generate
rotational percepts in a multistable motion display that usually produces only
horizontal or vertical motion percepts. The properties of the path-of-movement
lines are predicted by a neural-network theory of visual perception. Experimental
results validate the theory's predictions by demonstrating that movement of the
display elements seems to follow an increasing luminance gradient in lines but
not bars, and that illusory contours have similar effects. Experimental results
also demonstrate that, in a choice between movement along lines drawn parallel or
orthogonal to possible motion paths, observers more often see movement along the
lines parallel to the motion path. These results suggest modifications to current
computational and neurophysiological theories of motion perception.
PMID- 10694973
TI - Do monocular time-to-collision estimates necessarily involve perceived distance?
AB - Motivated by the debate between indirect and direct theories of perception, a
large number of researchers have attempted to determine whether judgments of time
to collision are based on the ratio of perceived distance to perceived speed or
on the ratio theta/(d theta/dt), i.e. tau. Despite the considerable research
effort devoted to this question there seems to be no clear resolution. We used a
staircase tracking procedure to estimate errors in estimating time to collision
for a simulated approaching object. To investigate the role of perceived distance
in the judgment of time to collision, we asked observers to alternate between two
viewing distances (100 and 500 cm). For the 500 cm viewing distance, we magnified
the visual display by a factor of five so that the retinal images [and the values
of theta/(d theta/dt) through time] were identical for the two viewing distances.
All visual cues to distance were available. There were no significant differences
between estimates of time to collision made at the two viewing distances. We
conclude that our observers ignored perceived distance when estimating time to
collision and based their responses on theta/(d theta/dt). We concur with recent
proposals that, in the future, time-to-collision research should move away from
the either/or analysis of different information sources that has dominated
previous studies towards investigations of how different information sources are
integrated.
PMID- 10694974
TI - Exocentric pointing in three-dimensional space.
AB - A study is reported of an exocentric pointing task in all three dimensions, in
near space, with only two visible luminous objects--a pointer and a target. The
task of the subject was to aim a pointer at a target. The results clearly show
that visual space is not isotropic, since every set direction appeared to consist
of two independent components--one in the projection onto a frontoparallel plane
(tilt), the other in depth (slant). The tilt component shows a general trend
across subjects, an oblique effect, and can be judged monocularly. The slant
component is symmetrical in the mid-sagittal plane, requires the use of binocular
information, and shows considerable differences between subjects. These
differences seem to depend on the amount of binocular information used by each
subject. There was a remarkably high level of consistency in the exocentric
pointing, despite the absence of environmental cues. The within-subject
consistency in the settings of the pointer corresponds to a consistency of about
1 min of arc in disparity of its tip, even though the pointer and target are
separated by more than 5 deg.
PMID- 10694975
TI - Effects of similarity in bandwidth on the auditory sequential streaming of two
tone complexes.
AB - We investigated the perceptual grouping of sequentially presented sounds-
auditory stream segregation. It is well established that sounds heard as more
similar in quality, or timbre, are more likely to be grouped into the same
auditory stream. However, it is often unclear exactly what acoustic factors
determine timbre. In this study, we presented various sequences of simple sounds,
each comprising two frequency components (two-tone complexes), and measured their
perceptual grouping. We varied only one parameter between trials, the
intercomponent separation for some of the complexes, and examined the effects on
stream segregation. Four hypotheses are presented that might predict the extent
of streaming. Specifically, least streaming might be expected when the sounds
were most similar in either (1) the frequency regions in which they have energy
(maximum spectral overlap), (2) their auditory bandwidths, (3) their relative
bandwidths, or (4) the rate at which the two components beat together
(intermodulation rate). It was found that least streaming occurred when sounds
were most similar in either their auditory or their relative bandwidths. Although
these two hypotheses could not be distinguished, the results were clearly
different from those predicted by hypotheses (1) and (4). The implications for
models of stream segregation are discussed.
PMID- 10694976
TI - A comment on "assimilation of achromatic color cannot explain the brightness
effects in the achromatic neon effect" by Marc K Albert.
PMID- 10694977
TI - Analysis of the proteome of Mycobacterium tuberculosis in silico.
AB - Novel bioinformatics routines have been used to provide a more detailed
definition of the proteome of Mycobacterium tuberculosis H37Rv. Over half of the
current proteins result from gene duplication or domain shuffling events while
one-sixth show no similarity to polypeptides described in other organisms.
Prominent among the genes that appear to have been duplicated on numerous
occasions are those involved in fatty acid metabolism, regulation of gene
expression, and the unusually glycine-rich PE and PPE proteins. Protein
similarity analysis, coupled with inspection of the genetic neighbourhood, was
used to explore possible functional relatedness. This uncovered four large mce
operons whose proteins may mediate initial interactions between the tubercle
bacillus and host cells, together with a cluster of genes that might encode
components of a structure required for secretion of ESAT-6 like proteins. Close
linkage of the mmpL genes, encoding large membrane proteins, with those required
for fatty acid metabolism suggests involvement in lipid transport. Compared to
free-living bacteria, M. tuberculosis has a significantly smaller transport
protein repertoire and this may reflect its intracellular lifestyle.
PMID- 10694978
TI - Detection of mutations in drug resistance genes of Mycobacterium tuberculosis by
a dot-blot hybridization strategy.
AB - SETTING: Mycobacterium tuberculosis isolates from patients in communities endemic
for tuberculosis in South Africa. OBJECTIVE: To develop a reliable PCR-based dot
blot hybridization strategy to detect mutations conferring drug resistance.
DESIGN: Different loci in six genes associated with drug resistance to isoniazid,
rifampacin, streptomycin and ethambutol were selected to develop the PCR-based
dot-blot hybridization strategy. RESULTS: Primers and probes to detect mutations
at codons 315, 463 (katG) 269 (kasA), 531, 526 (rpoB) 43 (rpsL), 513 (rrs) and
306 (embB) were designed and used to develop a PCR-based dot-blot hybridization
strategy. The dot-blot hybridization strategy with wild-type probes can
efficiently be used to detect drug resistant mutations since these do not
hybridize to mutant loci. Stripped blots and mutant probes can be used to
identify the precise mutation. The embB gene (ethambutol resistance) was used to
show how the dot-blot strategy can assist with the prediction of drug resistance
more accurately. The method is rapid, reproducible, not technically demanding and
samples can be done in batches. Additional loci can easily be incorporated.
CONCLUSIONS: A PCR-based dot-blot hybridization strategy is described which can
accurately identify drug resistant strains and the method is useful for patients
at risk and in areas endemic for tuberculosis.
PMID- 10694979
TI - Disruption of coding regions by IS6110 insertion in Mycobacterium tuberculosis.
AB - SETTING: The insertion sequence IS6110 is widely used as a DNA fingerprinting
probe for the classification of Mycobacterium tuberculosis strains. This study
has focused on the characterization of regions disrupted by insertion of the
IS6110 element. OBJECTIVE: To characterize IS6110 insertion loci in clinical
isolates of M. tuberculosis, in terms of their genomic location and genetic
identity, to ascertain whether IS6110 transposition could be a mechanism driving
phenotypic change. DESIGN: Thirty-three IS6110 insertion loci were cloned from 8
clinical isolates of M. tuberculosis. Clones representing DR locus insertions
were identified by hybridization (n = 4), and all other clones were characterized
by DNA sequencing (n = 29). The sequence data was analyzed in conjunction with
that of 43 other insertion loci identified in published literature and DNA
sequence databases. RESULTS: The 76 sequences analyzed represented 66 unique
insertion loci (including 9 unique insertions into the ipl locus). When mapped to
the H37Rv genome, the majority of unique insertion loci demonstrated disruption
of coding regions by IS6110 (n = 42; including the ipl insertions), while the
remainder either occurred within intergenic regions (n = 17), or could not be
mapped to the H37Rv genome sequence (n = 7). Mapping of the insertion loci
reveals distribution throughout the chromosome, with isolated preferential
insertion loci. CONCLUSIONS: This study has demonstrated the occurrence of 66
unique IS6110 insertion loci dispersed throughout the M. tuberculosis genome,
with an unexpectedly high incidence of IS6110 insertions occurring within coding
regions. However, the IS6110-mediated coding region disruptions identified here
may only have limited impact on phenotype, as most of the coding regions
disrupted are members of multiple gene families. Disruption of individual members
of a family of genes may have no effect on phenotype or could have a minor or
major impact, depending on the specificity and activity of the encoded protein.
PMID- 10694980
TI - Molecular epidemiology of tuberculosis in the Nord Department of France during
1995.
AB - In order to determine the current situation and to evaluate the human to human
transmission of Mycobacterium tuberculosis in Northern France, the genetic
polymorphism of strains was studied by using IS6110 fingerprint. One hundred and
fifty-eight cases of bacteriologically confirmed tuberculosis were analyzed. One
hundred and twenty-six patients (82%) were infected with genetically different
isolates and 28 isolates (18%) were grouped into 14 clusters. No risk factors for
recent Mycobacterium tuberculosis infections such as age, HIV status, immigrants,
living in big cities were identified. This study shows that there was no major
epidemic situation of tuberculosis in Northern France in 1995. Tuberculosis was
characterized by a low proportion of HIV positive patients and a high proportion
of elderly patients.
PMID- 10694981
TI - Growth of a highly virulent strain of Mycobacterium tuberculosis in mice of
differing susceptibility to tuberculous challenge.
AB - Mycobacterium tuberculosis strain CDC 1551 exhibited unusually high levels of
infectivity and virulence during a recent outbreak of tuberculosis in a rural
community. Mice infected intravenously or aerogenically with M. tuberculosis CDC
1551 developed infections in the lungs and spleen which were almost identical
with those for M. tuberculosis strains Erdman, H37Rv and Indian. There was also
no significant difference in the survival rates of mice infected intravenously
with CDC 1551, Erdman or H37Rv over a 3-month period. Studies designed to detect
differences in the growth rates of CDC 1551 and Erdman in 3 inbred strains of
mice failed to explain the high level of infectiousness and virulence expressed
by CDC 1551 in human populations exposed to this organism.
PMID- 10694982
TI - Human in vitro immune responses to Mycobacterium tuberculosis.
AB - SETTING: T helper cells can be divided into 2 subsets on the basis of their
cytokine generation. T helper 1 cells secreting gamma interferon and interleukin
2 appear to be more prominent in patients with limited tuberculous disease.
OBJECTIVE: The purpose of this study was to evaluate human T helper cell immune
responses to mycobacterial antigens in vitro and correlate these with the
clinical features of patients with tuberculous infection or disease. DESIGN: We
studied 51 subjects and 11 controls who were grouped according to disease
involvement as follows: 1) Mantoux negative, BCG negative, no disease; 2) Mantoux
positive, no disease; 3) localized extrapulmonary; 4) healed pulmonary; 5) active
pulmonary; and 6) miliary/disseminated. Peripheral blood mononuclear cells were
cultured with PHA, PPD or Tetanus Toxoid, proliferation assessed and the
supernatant analysed using an ELISA for IFN gamma. ELISA was also used to measure
M. tuberculosis specific antibodies in the serum. RESULTS: Mantoux size
correlated with PPD proliferation r = 0.5, P = 0.005 and gamma IFN production r =
0.36, P < 0.01. All groups produced abundant gamma IFN although there was a trend
toward higher production in groups 3 and 4. M. tuberculosis specific IgA (P =
0.003) and IgG1 (P = 0.002) was higher in groups 5 and 6. Those patients with
limited disease (groups 2-4) had significantly lower levels of IgG4 than patients
with severe disease (groups 5 & 6) (P < 0.02). CONCLUSION: In conclusion patients
with healed or extrapulmonary disease have immune responses in vitro suggestive
of a TH1 (cell mediated immune) response, whereas patients with
miliary/disseminated disease have antibody production suggestive of a TH2
response, together with high gamma IFN production. Both TH1 and TH2 responses may
be necessary for host protection if there is a high bacillary load.
PMID- 10694983
TI - Virulence of recent notorious Mycobacterium tuberculosis isolates.
PMID- 10694985
TI - Medical complications of diabetes mellitus in pregnancy.
AB - Many women with diabetes develop complications of their chronic disease that may
have a tremendous impact on their quality of life and their ultimate prognosis.
Because Type 1 diabetes often begins at a very early age, it is quite common for
women in their child-bearing years to be affected by these complications. As
described in this article, diabetic complications and pregnancy may significantly
affect each other, but it is not always easy to predict the course of either and
to counsel these patients accordingly. Nevertheless, it appears that only in rare
occasions should women with diabetes be advised against pregnancy, and that in
most situations, with careful and knowledgeable management, a favorable outcome
of pregnancy can be expected both for the mother and her infant.
PMID- 10694984
TI - Diabetes and pregnancy: four motifs of modern medical history.
PMID- 10694986
TI - Why do diabetic women deliver malformed infants?
PMID- 10694987
TI - Role of diet and insulin treatment of diabetes in pregnancy.
PMID- 10694989
TI - Obstetric management of pregnancies complicated by diabetes mellitus.
PMID- 10694988
TI - The role of exercise in pregnant women with diabetes mellitus.
PMID- 10694990
TI - Postpartum care of the woman with diabetes.
AB - The postpartum period in women with diabetes or GDM allows both the physician and
mother to relax from the intensive medical and obstetric management that has
permitted, in most cases, a successful and joyous outcome. The role of the
physician, however, must switch to a proactive and preventive mode to formulate a
reproductive health plan for women with diabetes and GDM. The plan should be
individualized to address glycemic management and surveillance, nutritional
management, contraception prescription, future pregnancy planning, and lifestyle
changes. Essential to the development of a reproductive health plan is the active
participation of the patient, who through education gains an understanding of the
far-reaching effects her active participation will have on her subsequent health
and possibly on that of her future children.
PMID- 10694991
TI - Physiologic and molecular alterations in carbohydrate metabolism during pregnancy
and gestational diabetes mellitus.
AB - Recent progress suggests that postreceptor mechanisms that contribute to insulin
resistance of pregnancy appear to be multifactorial, but are exerted at the beta
subunit of the insulin receptor and at the level of IRS-1. Gestational diabetes
mellitus represents the combination of acquired and intrinsic abnormalities of
insulin action. The resistance to insulin-mediated glucose transport appears to
be greater in skeletal muscle from GDM subjects than from pregnancy alone. There
is also a modest but significant decrease in maximal insulin receptor tyrosine
phosphorylation in muscle from obese GDM subjects. Results also suggest that
increased insulin receptor serine/threonine phosphorylation and PC-1 could
underlie the insulin resistance of pregnancy and pathogenesis of GDM. Whether
additional defects are exerted further downstream from IRS-1 remains to be
investigated.
PMID- 10694992
TI - Making the diagnosis of gestational diabetes mellitus.
PMID- 10694993
TI - Management of gestational diabetes.
PMID- 10694994
TI - Placental glucose transport in diabetic pregnancy.
PMID- 10694995
TI - The infant of the woman with gestational diabetes mellitus.
PMID- 10694996
TI - Cost analysis of diagnosis and treatment of gestational diabetes mellitus.
PMID- 10694997
TI - Complementary and alternative medicine: a primer.
PMID- 10694998
TI - Alternative therapies for menopause.
AB - If a woman does not want to use, or cannot use, hormone replacement therapy, then
she must consider other ways to address two issues related to menopause: reducing
her risk of developing cardiovascular disease, osteoporosis, and other health
problems that increase as women age, and symptomatology. Risk reduction of an
array of health problems can be achieved through diet, exercise, and stress
management. The nutraceuticals of specific vitamins, minerals, phytoestrogens,
and essential fatty acid supplementations are a vital component of the risk
reduction health program. Risk reduction of osteoporosis can be enhanced
specifically through the use of ipriflavone and a comprehensive "bone building"
vitamin and mineral program. Control of homocysteine levels for prevention of
CAD, osteoporosis, and other health problems can be accomplished through B
vitamin supplementation. The same interventions for risk reduction also may prove
to be effective in prevention and treatment of menopausal-related symptoms,
particularly when the B vitamins, magnesium, isoflavones, and essential fatty
acids are used. If lifestyle interventions and nutraceuticals do not adequately
address symptomatology, however, a woman has several alternative therapies from
which to choose. There are numerous excellent multiherbal and homeopathic
therapies that can be purchased over the counter. A woman also can choose to be
evaluated by an alternative therapy practitioner and have a program designed
specifically for her health needs. Although there has been limited clinical
research of herbal and homeopathic alternative therapies for the menopause, when
taken according to directions and if no contraindications exist, they have the
potential for being extremely effective and safe options.
PMID- 10694999
TI - Evaluation and management of insomnia in menopause.
AB - Insomnia is a problem with complex and multifactorial etiologies that requires
both standardized and individualized treatment interventions. Specific targets of
treatment may include hyperarousal, poor sleep habits, underlying mood disorders,
sedative overuse, pain and general medical problems, circadian dysrhythmias,
sleep apnea, and restless legs syndrome. Optimal treatment also will incorporate
stress management, coping strategies, enhancement of relationships, and promoting
lifestyle changes that facilitate sleep.
PMID- 10695000
TI - Menopause and cognitive function: estrogens and alternative therapies.
PMID- 10695001
TI - Helping women help themselves: developing a menopause discussion group.
AB - Menopause discussion groups are needed to provide women with accurate and up-to
date information, but--more importantly--to facilitate sharing experiences, to
help women understand their choices, and to empower them to be informed and take
care of themselves. Members of a group who are comfortable expressing their
feelings and thoughts find a therapeutic benefit from group participation. Health
care providers are urged to develop these groups in their communities to assist
women as they approach menopause and beyond.
PMID- 10695002
TI - Hormone replacement therapy: making a 45-year plan.
PMID- 10695003
TI - Diagnostic evaluation in gastroesophageal reflux disease.
AB - Gastroesophageal reflux disease (GERD) describes the clinical manifestations of
reflux of gastric contents and the associated symptoms and patterns of tissue
injury. Although its exact prevalence is difficult to determine, there is no
doubt the GERD is the most common esophageal disease and probably among the most
prevalent conditions seen in the primary care setting. GERD has a wide clinical
spectrum, making the diagnostic evaluation challenging and complicated at times.
Confirmatory test are rarely needed in patients with typical symptoms of
heartburn or regurgitation who have a good clinical response to GERD therapy.
This article describes the diagnostic tests necessary for some cases of GERD.
PMID- 10695004
TI - Overview of medical therapy for gastroesophageal reflux disease.
AB - There appears to be a hierarchy in the efficacy of therapies that are directed
against GERD. A summary of this hierarchy, including therapies [table: see text]
not approved by the U.S. Food and Drug Administration, is presented in Table 4.
The individual practitioner must evaluate the appropriate point at which to place
each patient on this hierarchy. Whether it is best to begin with the drug with
the highest efficacy and step-down as possible for maintenance, never to step
down, or to start with a less efficacious therapy and step up must also be
individualized because there are no clear data to support a universal approach to
all or even most GERD patients.
PMID- 10695005
TI - Medical therapy. Management of the refractory patient.
AB - Although relatively rare, GERD patients refractory to medical therapy remain a
challenge for the clinician. Refractoriness can be diagnosed only if the patient
is properly studied on medication and if what should be adequate medical therapy
has been given a sufficient therapeutic trial. Use of 24-hour intragastric and
intraesophageal pH-metry has improved the ability to manage patients who appear
to be nonresponders. Simple advice and minor adjustments to medical therapy are
usually all that is needed for most patients, but in some, management requires
knowledge of the principles outlined in this article. If followed, only a small
group of patients should be medically refractory.
PMID- 10695006
TI - Extraesophageal gastroesophageal reflux disease. Presentations and approach to
treatment.
AB - Prevalence of gastroesophageal reflux disease (GERD) is common in the adult US
population, but likely is underestimated as many patients present with symptoms
other than heartburn or regurgitation. Ears, nose, throat, pulmonary, and cardiac
symptoms also frequently are related to GERD. The diagnosis of GERD as a cause of
these symptoms can be difficult and treatment strategies are much less clear than
in patients presenting with heartburn or regurgitation. This article discusses
the epidemiology, pathogenesis, diagnosis, and treatment of some of the
manifestations of extraesophageal reflux disease.
PMID- 10695007
TI - Peptic strictures of the esophagus.
AB - Peptic esophageal strictures occur in the context of inadequately treated
gastroesophageal reflux, especially in elderly patients. Studies show more
pronounced abnormalities of esophageal function resulting in an increased number
of prolonged reflux episodes. The diagnosis is best made by a combination of
barium esophagram and endoscopy. Patients usually require esophageal dilation to
relieve dysphagia followed by adequate medical therapy. Proton pump inhibitors
are effective for preventing the recurrence of strictures after dilation. In
young patients and patients with strictures that are difficult to dilate or need
frequent dilations, surgery may be required; however, results can be
disappointing.
PMID- 10695008
TI - Endoscopy-negative gastroesophageal reflux disease. The hypersensitive esophagus.
AB - Gastroesophageal reflux disease (GERD) is one of the mos common disorders of the
gastrointestinal tract. Patients with GERD symptoms may exhibit a spectrum of
endoscopic findings ranging from normal endoscopy (EGD negative) to severe
ulcerative esophagitis. Recent evidence indicates that a large proportion of
patients with GERD have normal endoscopy. The use of 24-hour ambulatory pH
testing in the evaluation of symptomatic patients with EGD negative GERD allows
further classification of these subjects into groups. Patients who have abnormal
acid exposure and a positive symptom index constitute one group and patients who
have normal acid contact time but record a convincing relationship between their
symptoms and acid reflux on the pH analysis--positive symptom index--form another
group. The latter group has been suggested to have a hypersensitive esophagus or
"functional heartburn." This article reviews the prevalence, clinical features,
origin of patient's symptoms, natural history, and treatment of patients with EGD
negative GERD.
PMID- 10695009
TI - Motility abnormalities in gastroesophageal reflux disease.
AB - Esophageal dysmotility occurs in association with GERD; however, the cause of
these motility abnormalities is not known. It is also not clear whether injury
results from the presence of acid itself, inflammatory change or fibrosisin the
esophageal wall. It is also unclear if reversal of these abnormalities takes
place, and if so, to what degree. There are, however, a subset of patients who
seem to have improvement with effective medical or surgical therapy,
parodoxically, the same patients in whom a fundoplication, particularly a
complete wrap, would lead to severe postoperative dysphagia secondary to
preoperative dysmotility. What does all this mean for the individual patient? It
is likely that most will not have any important change in esophageal motility
abnormalities with standard medical or surgical therapy. Fundoplication might be
safely performed in patients with minimal motility abnormalities, but those with
severe abnormalities should be approached with caution. The conservative approach
is to perform a partial fundoplication (Toupet) in those with ineffective
motility (> 30% low-amplitude or nontransmitted contractions). It is hoped that
future investigations will aid in understanding the pathogenesis of these
abnormalities and how they can be used more precisely to guide antireflux
therapy.
PMID- 10695010
TI - Barrett's esophagus. Reducing the risk of progression to adenocarcinoma.
AB - Barrett's metaplasia develops in 6% to 14% of individuals with gastroesophageal
reflux. Barrett's adenocarcinomas are increasing in epidemic proportions for, as
yet unknown, reasons; approximately 0.5% to 1% of patients with Barrett's
metaplasia develop adenocarcinoma. Heartburn duration and frequency (but not
severity), male gender, and white race are major risk factors for developing
cancer. Obesity and smoking are weak risk factors. Survival is determined by
depth of tumor invasion (stage). Once invasion of the muscularis propria occurs,
most patients have developed widespread metastasis, even when clinical staging
studies are negative. No currently available therapy results in prolonged
survival once metastases develop. Thus, the more widespread use of effective
surveillance strategies is the only currently available means for reducing the
morbidity and mortality associated with Barrett's adenocarcinoma.
PMID- 10695011
TI - Gastroesophageal reflux disease in children.
AB - In the pediatric population, gastroesophageal reflux most often presents in
infancy as effortless regurgitation, but pathologic GERD is accompanied by signs
of malnutrition, respiratory diseases, and esophagitis or its complications.
Because of the distinctive pathophysiology predisposing infants to GERD, the
diagnostic approach must begin with a thorough history that determines the extent
of further diagnostic tests and the course of management. Empiric therapy assumes
importance in infants with GERD because of the limited differential diagnoses in
consideration. Conservative therapy is of utmost importance because of the unique
provocative factors in the pathophysiology of infantile GERD. Prokinetic
pharmacotherapy takes precedence over acid suppression because of the more
important role of motility factors compared with acid secretion in infantile
GERD.
PMID- 10695012
TI - Helicobacter pylori and gastroesophageal reflux disease.
AB - The nature of the relationship between Helicobacter pylori (Hp) infection and
gastroesophageal reflux disease (GERD) remains unclear. This article reviews the
current body of knowledge regarding the association between these two common
entities. The authors examine the potential interactions of Hp and GERD from
epidemiologic and pathophysiologic viewpoints and summarize and critique the
prevalence and eradication studies that have been performed to date. Special
consideration is given to the possible effects that long-term use of proton pump
inhibitors may have on Hp gastritis.
PMID- 10695013
TI - Antireflux surgery. Indications, preoperative evaluation, and outcome.
AB - Gastroesophageal reflux disease (GERD) is an extremely common disorder. Many
patients require lifelong medical therapy for symptom control. In patients being
considered for antireflux surgery, thorough evaluation is required. Laparoscopic
antireflux surgery is a safe and effective method of treating patients who have
severe, refractory, or complicated GERD. Excellent long-term results are obtained
with minimal morbidity, freeing the patient from the burden of chronic medical
therapy.
PMID- 10695014
TI - Postfundoplication complications. Prevention and management.
AB - Management of post-fundoplication problems begins by preventing complications
from occurring. The prevention of complications after antireflux surgery can be
divided into three important areas: (1) patient selection, (2) selection of the
surgery, and (3) selection of the surgeon. After addressing prevention
techniques, the author discusses the management of new postoperative symptoms
such as Dysphagia, gas-bloat syndrome, and nausea and vomiting.
PMID- 10695015
TI - [Mechanisms for resistance to anticancer agents and the reversal of the
resistance].
AB - MDR results from overexpression of P-glycoprotein (Pgp) and multidrug resistance
protein (MRP or MRP1) that function as ATP-dependent efflux pumps. Lung
resistance related protein (LRP) is also supposed to be involved in MDR. The
human canalicular multispecific organic anion transporter (cMOAT) gene that is
responsible for the defects in Dubin-Johnson syndrome was isolated. cMOAT is
homologous to MRP1 and supposed to be involved in drug resistance. Human cMOAT
cDNA transfected LLC-PK1 cells, LLC/cMOAT-1, have increased resistance to
vincristine (VCR), 7-ethyl-10-hydroxycamptothecin (SN-38), and cisplatin. The
multidrug resistance (MDR)-reversing agents, cyclosporin A (CsA) and PAK-104P,
almost completely reversed the resistance to VCR, SN-38 and cisplatin of
LLC/cMOAT-1 cells by interacting with the substrate binding site of cMOAT.
Treatment of human colorectal carcinoma SW-620 cells with sodium butyrate(NaB)
induced LRP in the cells and conferred resistance to Adrianycin(ADM), VCR, VP-16,
gramicidin D and taxol. Two LRP-specific ribozymes inhibited the NaB-induced
expression of LRP in SW-620 cells and almost completely abolished their
acquisition of the MDR phenotype. The accumulation of ADM, VCR and taxol was not
decreased in NaB-treated cells, suggesting that ATP-binding cassette transporters
are not involved in the MDR of NaB-treated cells. ADM was mainly located in the
nuclei of untreated and the cytoplasm of NaB-treated cells. The accumulation
level of ADM in the nuclei isolated from untreated cells or those from treated
cells in the presence of anti-LRP polyclonal antibody was higher than that from
treated cells in the absence of the antibody. Efflux of ADM from nuclei isolated
from NaB-treated cells was enhanced compared with those from untreated cells and
NaB-treated cells transfected with a LRP-specific ribozyme. The polyclonal
antibody against LRP inhibited the enhanced efflux of ADM from nuclei isolated
from NaB-treated cells. These findings indicate that LRP is involved in
resistance to ADM, VCR, VP-16, taxol and gramicidin D, and has an important role
in the transport of ADM from the nucleus to the cytoplasm.
PMID- 10695016
TI - [Gene therapy for inherited diseases using heamatopoietic stem cells--gene
therapy for patients with chronic granulomatous disease].
AB - The possibility of gene therapy for inherited diseases with a single gene
mutation in Figure 1 had been verified by the successful treatment with bone
marrow transplantation. As the gene therapy method and theory has been
progressing rapidly, it is expected that gene therapy will overcome the
complications of bone marrow transplantation. Of these inherited diseases,
chronic granulomatous disease (CGD) is the one of the most expected disease for
gene therapy. CGD is an inherited immune deficiency caused by mutations in any of
the following four phox genes encoding subunits of the superoxide generating
phagocyte NADPH oxidase. It consists of membranous cytochrom b558 composed of
gp91 phox and p22 phox, and four cytosolic components, p47 phox, p67 phox, rac
p21 and p40 phox, which translocate to the membrane upon activation. In our group
study, more than 220 CGD patients has been enrolled. The incidence of CGD
patients was estimated as 1 out of 250,000 births. The expected life span of the
CGD patients is 25 to 30 years old by the Kaplan Meier analysis. Comparing with
the ratio of CGD subtype in US and Europe, that with p47phox deficiency is lower
(less than 10%/o vs. 23%) and that of gp91 phox deficiency is higher (more than
75% vs. 60%). Prophylactic administration of ST antibiotics and IFN-gamma and
bone marrow transplantation have been successfully employed in our therapeutic
strategy. However, it is necessary to develop the gene therapy technology for CGD
patients as more promising treatment. In the current study we constructed two
retrovirus vectors; MFGS-gp91/293 SPA which contains only the therapeutic gp91
phox gene, a bicistronic retrovirus pHa-MDR-IRES-gp91/PA317 which carries a multi
drug resistant gene (MDR1) and the gp91phox gene connected with an internal
ribosome entry site (IRES). We demonstrate high efficiency transduction of gp 91
phox to CGD EB virus established cell line with high levels of functional
correction of the oxidase by MFGS-gp91 and by pHa-MDR-IRES-gp91, respectively. We
also demonstrate sufficient transduction of gp91 phox to CD34+ hematopoietic stem
cell from the patients with gp91 phox deficiency by MFGS-gp91/293 SPA. Our
current studies suggest that the combination of the 293-SPA packaging system and
the bicistronic retrovirus system inserted MDR1 gene make our CGD gene therapy
more feasible for clinical application.
PMID- 10695017
TI - [Gene therapy of cardiovascular disorders].
AB - More than 300 protocols have been developed for human gene therapy, but, it has
not yet been proved to be a successful therapeutic strategy. One of the most
important barriers to success is the development of efficient gene delivery
systems. We have developed HVJ-liposomes by combining fusion proteins of HVJ
(Hemagglutinating virus of Japan; Sendai virus) with liposomes containing DNA.
This vector system has been very effective for in vivo gene delivery, especially
in cardiovascular systems. Using HVJ-liposomes, we have reported successful gene
therapy experiments such as prevention of restenosis after balloon injury,
suppression of dysfunction of vein graft, and experimental ischemic disorders.
Indeed, the success in the treatment of arteriosclerosis obliterance by VEGF
(vascular endothelial growth factor) gene transfer was reported recently. These
cardiovascular gene therapy strategies appear to be very promising therapeutics
in future.
PMID- 10695018
TI - [Gene therapy using anticancer drug-resistance genes].
AB - Myelosuppression is a major dose-limiting factor in cancer chemotherapy.
Introduction of drug-resistance genes into bone marrow cells of cancer patients
has been proposed to overcome this limitation. In theory, any gene whose
expression protects cells against the toxic effects of chemotherapy should be
useful in vivo for this purpose. Among such genes, human multidrug-resistance
gene (MDR1) has been studied most extensively for this purpose, and clinical
trials of drug-resistance gene therapy have been started in the US for cancer
patients who undergo high-dose chemotherapy with autologous hematopoietic stem
cell transplantation. In Japan, our clinical protocol of MDR1 gene therapy "A
clinical study of drug-resistance gene therapy to improve the efficacy and safety
of chemotherapy against breast cancer" has been submitted to the government. To
improve the efficacy and safety of this drug-resistance gene therapy, we have
constructed a series of MDR1-bicistronic retrovirus vectors using a retrovirus
backbone of Harvey murine sarcoma virus and internal ribosome entry site (IRES)
from picornavirus to co-express a second gene with the MDR1 gene. MDR1-MGMT
bicistronic vectors can be used to protect bone marrow cells of cancer patients
from combination chemotherapy with MDR1-related anticancer agents and
nitrosoureas. In addition, MDR1-bicistronic retrovirus vectors can be designed to
use the MDR1 gene as an in vivo selectable marker to enrich the transduced cells
which express therapeutic genes, if disease is curable by the expression of a
single-peptide gene in any types of bone marrow cells or peripheral blood cells.
PMID- 10695019
TI - [Gene therapy for acute hepatitis using CrmA gene transduction].
AB - Fas-Fas ligand interactions between adenovirus-infected hepatocytes and cytotoxic
T lymphocytes (CTLs) play a major role in killing of vector-transduced
hepatocytes. Cytokine response modifier A (CrmA) is known to protect lymphoid
cells from Fas-mediated apoptosis by inhibiting caspase 8. In this study, we
generated an E1-deleted adenovirus expressing CrmA, and investigated the effect
of exogenous CrmA expression on the inhibition of Fas-mediated apoptosis in
murine hepatocytes in vitro and on the prolongation of the transgene expression
in adenovirus-transduced hepatocytes in vivo. Agonistic anti-Fas antibody induced
massive apoptosis into hepatocytes, however, most of the cells expressing CrmA
were escaped from apoptosis and survived. This result showed that anti-apoptic
function was obtained in murine hepatocytes by expressing CrmA. The prolongation
of the transgene expression was studied using mice with congenital deficiency of
lysosomal beta-glucuronidase (GUSB). The serum GUSB activity from the mice
injected only an adenovirus expressing human beta-glucuronidase disappeared
within 70 days, however, significant GUSB activity was observed for more than 130
days in the mice co-transduced with adenoviruses expressing both GUSB and CrmA.
Moreover, histochemical analysis showed GUSB expressions in the liver even at 130
days after the viral administration. These observations demonstrate that the
prolongation of the transgene expression can be achieved in rodent liver by CrmA
co-expression using adenoviral gene transfer.
PMID- 10695020
TI - Establishment and characterization of cell lines derived from serous
adenocarcinoma (JHOS-2) and clear cell adenocarcinoma (JHOC-5, JHOC-6) of human
ovary.
AB - The cell lines designated JHOS-2, JHOC-5 and JHOC-6 were established from
epithelial ovarian carcinomas. JHOS-2 was established from a serous
adenocarcinoma of a 45-year-old Japanese woman, JHOC-5 from a recurrent tumor of
a clear cell adenocarcinoma of a 47-year-old Japanese woman and JHOC-6 from a
tumor of a clear cell adenocarcinoma of a 43-year-old Japanese woman. These cell
lines have grown well and serial passages were successively carried out more than
20 times. The monolayer cultured cells revealed neoplastic and pleomorphic
features, and grew in multilayers. Electron micrographs revealed epithelial
origins that had desmosomes and tonofilaments.
PMID- 10695021
TI - Establishment and characterization of human ovarian clear cell adenocarcinoma
cell line (SMOV-2), and its cytotoxity by anticancer agents.
AB - A novel cell line derived from a surgically resected ovarian clear cell
adenocarcinoma of 46 year-old Japanese woman was established and designated SMOV
2. Cells of this lineage were continuously propagated in vitro over 44 months and
were grown in a mono-layered sheet with a doubling time of 48.2 hours. The
histopathology of the transplanted tumor in nude mice showed two distinctive cell
types, hobnail cells and clear cells, which demonstrated recognizable
characteristics of clear cell adenocarcinoma, as compared to resected original
tumors. At the molecular level, SMOV-2 cells had the wild type p53 genes that
were free from missence mutations. Anticancer agents (cisplatin and paclitaxel)
were examined for cytotoxity against these SMOV-2 cells in vitro. These
examinations revealed that the chemotherapy-treated cells had decreased
proliferation, cell cycle arrests, and induction of apoptosis by the anticancer
agents. As can be gleaned from this research, SMOV-2 is a valuable model to study
the mechanism of apoptotic responses of solid tumors to future anticancer agents.
PMID- 10695022
TI - Efficient DNA fingerprinting method for the identification of cross-culture
contamination of cell lines.
AB - In order to identify cross-culture contamination of cell lines, we applied DNA
fingerprinting using variable number of tandem repeat (VNTR) loci and short
tandem repeat (STR) loci amplified by polymerase chain reaction (PCR) instead of
a radioisotope labeled multilocus probe. Eleven cell lines were used for the Apo
B and D1S80 loci detection, and twelve cell lines were examined in the Y
chromosome analysis. The data obtained from the sister cell lines NALM-6 and B85,
two MOLM-1 cultures from two cryopreserved tubes, and four subclones of BALM-9
and its sister cell line BALM-10, displayed clear and distinct bands of each PCR
product for both Apo B and D1S80. Detection of a Y-chromosome DNA sequence is
another very informative marker for the identification of cell lines, if the Y
chromosome is present. We examined eight cell lines for the expression of four
STR loci; the data thus generated were compared with the results previously
reported from other laboratories. The resulting electrophoretic banding patterns
showed that our "home-made" STR detection system is a useful and efficient tool
for the authentication of cell lines. PCR detection of VNTR and STR loci
represents a simple, rapid and powerful DNA fingerprinting technique to
authenticate human cell lines and to detect cross-culture contamination. This PCR
technique may be used in lieu of the more time-consuming, labor-intensive and
radioactive Southern blot multilocus method.
PMID- 10695023
TI - [Reliability of disc-diffusion susceptibility testing for arbekacin, vancomycin
and teicoplanin against methicillin-resistant Staphylococcus aureus].
AB - We investigated the differences in judgments among four disc-diffusion methods on
susceptibility testing of arbekacin (ABK), vancomycin (VCM) and teicoplanin
(TEIC) against 37 strains of methicillin-resistant Staphylococcus aureus (MRSA).
These results were compared with minimum inhibitory concentrations (MICs)
obtained from micro broth-dilution method. A marked difference was noted in the
judgment of susceptibility to TEIC in Tri-disc method, that is 2 strains (5.4%)
fell into sensitive (+3) 34 strains (91.9%) into moderately sensitive (+2) and 1
strain (2.7%) into moderately resistant (+), while in Sensi-disc method all
strains fell into sensitive (S). According to the MICs, no strain of the MRSA
tested revealed resistance to ABK, VCM and TEIC. Consequently, these three
antimicrobial agents were thought to be effective on MRSA infections. From these
results, we concluded that Tri-disc method for glycopeptide against MRSA,
especially for TEIC, is not recommendable as a disc-diffusion method in
susceptibility testing.
PMID- 10695024
TI - [In vitro activity of biapenem (BIPM) against clinically isolated respiratory
pathogens in 1996-1998].
AB - The in vitro antibacterial activity of biapenem (BIPM), a new carbapenem
antibiotic, was compared with those of imipenem (IPM), panipenem (PAPM),
meropenem (MEPM), ceftazidime (CAZ) and piperacillin (PIPC) against 280 isolates
of 9 respiratory pathogens. The MIC90s of biapenem (BIPM) for methicillin
susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus
aureus (MRSA), Streptococcus pneumoniae, Moraxella catarrhalis, Pseudomonas
aeruginosa, and Haemophilus influenzae were 0.12, 32, 0.25, 0.06, 4 and 8
micrograms/ml, respectively. In comparison with other antibiotics, the activity
of biapenem (BIPM) for P. aeruginosa was as potent as meropenem (MEPM), but for
H. influenzae it was slightly less than those of other antibiotics, and for other
respiratory pathogens it was as potent as those of other antibiotics. The MIC90s
of biapenem (BIPM) for Escherichia coli, Klebsiella pneumoniae, Enterobacter
cloacae and Serratia marcescens were 0.06, 1, 1, 0.5 microgram/ml, respectively,
and which were equal to or somewhat lower than those of other antibiotics.
Biapenem (BIPM) showed strong activity against Gram-positive and Gram-negative
pathogens, especially P. aeruginosa in general. Based on these results, biapenem
(BIPM) is seemed to be highly useful antibiotic for the treatment of respiratory
infections with several organism.
PMID- 10695025
TI - [Antimicrobial activities of meropenem against clinically isolated strains in
1997].
AB - In order to evaluate antimicrobial activity of meropenem (MEPM), minimum
inhibitory concentrations (MICs) of MEPM and control drugs were determined
against clinical isolates in 1997. The results were as follows; 1. Antimicrobial
activities of MEPM against Gram-positive bacteria were stronger than those of
cephems (CEPs) and were approximately equal to those of imipenem (IPM) and
panipenem (PAPM). 2. Carbapenems showed strong antimicrobial activities against
Enterobacteriaceae, Glucose non-fermentative Gram-negative rods and Bacteroides
fragilis group that were multiple drug resistant including the third generation
CEPs. Antimicrobial activities of MEPM against these organisms were stronger than
those of IPM and PAPM. By comparing antimicrobial activities of MEPM against Gram
negative bacteria in 1997 with those obtained in 1993, increase of resistance was
not observed. 3. MIC-ranges of MEPM were low against the resistant strains of
Pseudomonas aeruginosa to IPM and PAPM. It was considered that these resistant
strains were not expressing oprD products (D2 porin protein), forming main outer
membrane porin channels of carbapenems and basic amino acids.
PMID- 10695026
TI - [Pharmacotherapy of depression in the elderly].
AB - Antidepressants are not only effective in younger adults but also in older
persons with depression. However there are peculiarities, which have to be taken
into account when treating older patients. The enhanced risk of side effects has
to be balanced with the more serious consequences of an untreated depression in
old age. The efficacy in older patients has been proven not only for tricyclic
antidepressants but also for SSRI and other newer antidepressants. The easy
handling, the side effect profile and the safety in overdose are advantages of
SSRI and newer antidepressants, which become particularly important in old age.
The advantages and disadvantages of different classes of antidepressants with
regard to comorbidity and comedication are discussed. In older subjects, changes
of dosage should be slower and for some, but not for all antidepressants, dosage
should be lower.
PMID- 10695027
TI - [Detection of neurotransmitter interactions with PET and SPECT by pharmacological
challenge paradigms].
AB - Functional brain imaging with positron emission tomography (PET) and single
photon emission computerized tomography (SPECT) enables the in vivo study of
specific neurochemical processes in the context of normal regulatory mechanisms
and pathophysiological alterations of the brain. By combining these methods with
pharmacological challenge-paradigms, the study of functional interactions of
different neurotransmitter systems is possible. This review will present data
from animal and healthy volunteer studies as well as first data from
investigations in different patient populations with regard to this research
direction. Especially, interactions of different neurotransmitter systems with
the dopaminergic and the cholinergic system will be discussed. The database
acquired so far confirms existing models of neuronal feedback-circuits, and the
first clinical results are consistent with the hypothesis of an increased
dopaminergic responsivity in schizophrenic patients. These results open up new
perspectives for a further evaluation of treatment response predictors from drug
challenge studies and for the development of new drug treatments for
neuropsychiatric disorders.
PMID- 10695028
TI - [Cognitive remediation. A new chance in rehabilitation of schizophrenic
disorders?].
AB - A critical review of current approaches and principles of cognitive remediation
strategies in rehabilitation of schizophrenia is given. Selection of cognitive
functions targeted in compensatory training programs could be based on results of
neuropsychological predictor research on social and vocational functioning in
community and neuropsychological rate limiting factors in rehabilitation.
Methodological flaws in data base, missing of task analysis of more complex
skills like social perception, social skills and interpersonal problem solving
and the lack of evaluation of training generalization on work performance are
discussed. Finally the cognitive remediation program developed in the Department
of General Psychiatry and Psychotherapy/University of Freiburg, Germany is
proposed. The components focused on training in attention, memory, and executive
function (decision making, planning). Compensatory strategy building, and
computer-mediated automatization are integrated in a group setting.
PMID- 10695029
TI - [Effect of activation tasks on acute neuroleptic-induced akathisia].
AB - In this study, we investigated experimentally the effects of different activation
procedures on both motor and psychic symptoms in of 11 in-patients with acute
neuroleptic-induced akathisia using the Hillside and Barnes akathisia rating
scales and videotape rating technique. Motor activation was achieved by finger
tapping. Cognitive activation tasks consisted of sequences of mental calculations
which were designed either to be easy to perform or to produce stress due to a
given time limit or to more difficult calculation operations, respectively. Motor
as well as psychic symptoms of akathisia decreased during both motor and simple
cognitive activation without stress. By contrast, stress-producing calculation
tasks led to an increase in motor and psychic symptoms immediately following the
task performance. These possibly specific effects of activation procedures on
symptoms might be useful in differentiating acute neuroleptic-induced akathisia
from other neuroleptic-induced and extrapyramidal movement disorders.
PMID- 10695030
TI - [Clinical aspects of "argyrophilic grain disease"].
AB - Argyrophilic grain disease (AGD) is a frequently occurring degenerative illness
of the aging human brain. It is accompanied by progressive pathological
alterations of the cytsokeleton which are traceable to an abnormal
phosphorylation of the microtubule associated tau protein. Histologically, it is
possible with the help of suitable staining techniques to identify pathognomonic
spindle-shaped cellular inclusions (argyrophilic grains). These cellular
inclusions display a typical cortical as well as subcortical distribution
pattern. The goal of the present study is the retrospective evaluation of the
clinical findings from 53 individuals with neuropathologically demonstrable AGD
related changes of the brain. Nearly one-half of the cases (49%) was classifiable
as demented in accordance with DSM IV-criteria. Moreover, the frequency of the
dementia increased significantly in relation to the growing severity of the AGD
associated pathological cytoskeletal degeneration. These results confirm the
assumption that AGD can cause degenerative changes ranging from cognitive
impairment all the way to dementia. They also underscore the necessity of further
prospective studies pertaining to the clinical aspects of this still enigmatic
disease.
PMID- 10695031
TI - [Early manifestation of fronto-temporal dementia].
AB - The term frontotemporal dementia is used to describe a primary degenerative form
of dementia, which is characterized by typical clinical, neuropsychological,
radiological and neuropathological features. Its onset is usually before the age
of 65 years; manifestations before the age of 30 years have rarely been
described. We report the case of a 22-year old man, who showed symptoms of
behavioural disorder such as social retreat, lack of initiative, mental rigidity,
progressive reduction of speech, and stereotyped behaviour. The
neuropsychological examination revealed disorders of the executive functions. The
cerebral MRI investigations showed bifrontal atrophies corresponding with
hypoperfusion areas on the SPECT. Other investigations including EEG, evoked
potentials, duplex ultrasonography, cerebral angiography, laboratory tests and
cerebrospinal fluid were normal. In the present case report we discuss the
clinical presentation of frontotemporal dementia with early onset.
PMID- 10695032
TI - [Propane abuse. Extreme dose increase due to development of tolerance].
AB - In spite of its serious sequelae, volatile substance abuse (VSA) attracts very
little public attention in Germany. Our case report describes an adult male who
inhaled propane for recreational purposes. Initially, he achieved short-lived
euphoria and hallucinations. He compensated for the developing tolerance by
increasing the dosage, finally consuming 5 litres of fluid propane daily. Getting
such quantities was facilitated by his occupational access to propane. Since he
abused the propane in an apartment house, he also exposed third parties to the
danger of explosion. Clinical examination revealed disturbances in orientation,
restricted perceptivity and concentration, reduced mnemonic performance, and
psychomotor agitation. All these symptoms diminished during a 6-month follow-up.
The relationship of his organic mental disorder to the abuse of propane was not
clear, since he had also abused alcohol.
PMID- 10695033
TI - [The dopamine hypothesis of schizophrenia. New findings for an old theory].
AB - The dopamine hypothesis of schizophrenia was based on the neuroleptical blockade
of central dopamine D2 receptors. Brain imaging studies, however, generally
failed to demonstrate a significant increase in central D2 receptors among
schizophrenic patients. Using a novel approach, the group of Laruelle and Abi
Dargham was now able to demonstrate that schizophrenic patients have increased
synaptic dopamine concentrations in the striatum. Endogenous dopamine competes
with a radioligand for binding at dopamine D2 receptors; compared to healthy
control subjects, blockade of dopamine production in neuroleptic-naive
schizophrenic patients induced a significantly higher increase in D2 binding of
the infused radioligand, indicating higher endogenous synaptic dopamine. A
similar increase in D2 binding was also observed in drug-free schizophrenics who
had previously been treated with neuroleptics; these patients also showed an
increased density of striatal D2 receptors, most likely due to counteradaptive
upregulation of D2 receptors during neuroleptic medication. The Columbia study
provides an important indication of hyperdopaminergic function in schizophrenia.
PMID- 10695034
TI - [Omega-3 fatty acids in psychiatry].
AB - Omega-3 fatty acids (ALA, EPA, DHA) are essential polyunsaturated fatty acids.
Due to their pivotal involvement in signal transduction processes in the CNS, a
role for these fatty acids in psychiatric disorders has been postulated. This
review summarizes the latest findings on the physiological function of these
compounds in the CNS and gives a comprehensive overview on the emerging
therapeutic role of these psychoactive drugs in psychiatric disorders, with
special emphasis being put on affective disorders and schizophrenia.
PMID- 10695035
TI - [Cytokines in viral infections].
AB - The role of cytokines and chemokines in viral replication and antiviral immunity
is discussed. Some viruses may have genes that mimic the host genes (cytokines or
cytokine receptors) and their functioning may inhibit the synthesis or processing
of cell proteins important for defense. Some of host cytokines may be involved in
the pathogenesis of viral infection (HIV, herpes virus, cytomegalovirus, and some
others).
PMID- 10695037
TI - [Serological study of hepatitis C virus NS5 protein epitopes and their clinical
and diagnostic significance].
AB - Three peptides corresponding to the 2295-2317 aa NS5 HCV region and individual
parts of this region were synthesized. Antigenic properties of these peptides
were investigated. The 2295-2317 aa region contains at least two epitopes of
different nature. The full-sized peptide is more promising for the diagnostic
studies. Optimal conditions for ELISA with this peptide were defined, allowing
the maximum complete utilization of the potentialities of both epitopes.
PMID- 10695036
TI - [Distribution and features of infection with hepatitis viruses B and C during
hemodialysis treatment].
AB - The prevalence of hepatitides B and C was evaluated in 140 patients treated by
hemodialysis. Almost half of patients (48%) had acute hepatitis B which
completely resolved. Acute hepatitis B was detected in 6% in the course of
observation. In 6% chronic hepatitis B was diagnosed, and in 24% chronic
hepatitis C. A combination of hepatitides B and C was diagnosed in 2% patients.
Only 12% patients were not infected with hepatitis. Genotype 1b predominated in
patients with HCV infection (73%); genotypes 1a, 21, and 3a were equally incident
(9%). Replication of HBV and HCV in patients with uremia under conditions of
hemodialysis was detected in 83 and 86% patients, respectively. Relationship
between HBV and HCV infection and the duration of hemodialysis treatment was
analyzed. The percentage of non-infected patients persistently decreased, and the
time course of HBV and HCV infection was different. Infection with HBV after the
beginning of hemodialysis occurred sooner (16.0 +/- 4.0 months) than with HCV
(30.2 +/- 4.6 months, p < 0.04). The levels of SGPT and SGOT in patients with
various manifestations of HBV and HCV infection treated by hemodialysis were
followed up.
PMID- 10695038
TI - [Clinico-laboratory characteristics of viral hepatitis C with various HCV
genotypes].
AB - Clinical and biochemical features of the acute phase of icteric hepatitis C in
various HCV genotypes have been studied. The HCV genotypes determine the duration
of incubation period and some clinical signs in the preicteric and icteric
periods of acute hepatitis C. The biochemical picture and formation of chronic
hepatitis virtually did not depend on the virus genotype.
PMID- 10695039
TI - [Gene analysis and phenotypic characteristic of highly-reproductive reassortants,
containing the gene for bird influenza virus subtype H2 hemagglutinin].
AB - A series of reassortant clones with antigenic formulae H2N1 and H2N3 were
produced by genetic reassortment performed with the use of an avian influenza
virus, A/Pintail Duck/Primorie/695/76 (H2N3) and a high-yield reassortant strain
X-67. Preliminary identification of the parent origin of NP and NS genes for 5
reassortants was performed by comparison of the mobilities of virus-specific
proteins in polyacrylamide gel electrophoresis. The parent origin of genes of
internal and nonstructural proteins for 3 reassortants was identified by partial
sequencing. Although the genes of internal and nonstructural proteins of the
reassortants originated from high-yield X-67 virus, only H2N3 reassortants were
similar to the high-yield parent virus as concerns the level of the virus
accumulation evaluated by hemagglutination titration and measurement of the virus
protein content.
PMID- 10695040
TI - [Production of interleukin-2 in vitro and in vivo in elderly people, vaccinated
with live and inactivated flu vaccines separately and combined].
AB - Forty-three elderly individuals were immunized with Russian trivalent live cold
adapted influenza vaccine (LIV) and US trivalent influenza vaccine (IIV)
administered separately or in combination. IL-2 production in vitro (in
supernatants of cultures of lymphocytes stimulated with homologous viral antigens
and PHA) and in vivo (in blood serum) and other factors of specific antiinfluenza
immunity were compared. Vaccination of elderly subjects with commercial vaccines
induced T-helper immunological memory, which manifests by increased secretion of
IL-2 in vitro and in vivo. Simultaneous vaccination with LIV + IIV and
revaccination (in 1 month) with LIV was the most effective method stimulating IL
2 production. The levels of IL-2 production in vitro were in good correlation
with the secretion of this cytokin in vivo, lymph proliferation, and serum
antibody production. No correlation between IL-2 production in vitro and the
formation of local immune response (IgA in nasal swabs) was detected.
PMID- 10695041
TI - [Mechanisms for the therapeutic effect of herpes polyvaccines in chronic
ophthalmic herpes and genital herpes].
AB - Commercial inactivated culture polyvaccine against herpes simplex viruses (types
1 and 2) developed at D. I. Ivanovsky Institute of Virology promoted cessation of
viremia. During the first vaccination viremia coincided with appearance of a
focal allergic test on the retina, which is proposed for the diagnosis of
herpetic involvement of the posterior compartment of the eye. T-cellular immunity
normalized after a course of vaccination. Experimental immunization of rats and
vaccination of patients with chronic ophthalmic and genital herpes demonstrated
the therapeutic activity of inactivated herpetic polyvaccine in suppositoria.
PMID- 10695042
TI - [Protective effect of a new antiviral preparation of phosprenyl in experimental
tick-borne encephalitis].
AB - Antiviral activity of phosprenyl was studied in BALB/c mice infected with tick
borne encephalitis (TBE) virus. Up to 60% animals infected with TBE virus
survived after 1-3 intramuscular injections of phosprenyl. The mortality in the
untreated group infected with the virus was 100%. Direct antiviral effect of
phosprenyl was studied in sensitive SPEV cells infected with TBE virus. The titer
of the virus decreased 10-fold in the cells treated with the drug vs. untreated
control cells. Phosprenyl stimulates some interleukins: gamma-interferon, tumor
necrosis factor-alpha, and interleukin-6. The stimulating effect of the drug
manifests in intact animals and in those infected with TBE virus and treated with
phosprenyl. The prospects of further trials of the drug as a therapeutic and
prophylactic agent in TBE are discussed.
PMID- 10695043
TI - [Epidemic outbreak of meningitis and meningoencephalitis, caused by West Nile
virus, in the Krasnodar territory and Volgograd region (preliminary report)].
AB - Sera from 102 inpatients from the Volgograd region (64) and Krasnodar region (38)
were tested for antibodies to West Nile (WN) virus in hemagglutination inhibition
(HI) test and for IgM and IgG antibodies in enzyme immunoassay (EIA). Diseases
etiologically associated with WN virus were diagnosed in 81 patients: in 50 out
of 64 in the Volgograd region and in 31 out of 38 in the Krasnodar region, which
makes 79.4%. Specificity of antibodies to WN virus was confirmed in HI and EIA
with WN antigens, related flaviviruses (Japanese encephalitis and yellow fever),
and Sindbis alfavirus. A considerable number and the incidence of WN infection
suggest that an epidemic caused by WN virus occurred in the Krasnodar and
Volgograd regions in summer 1999.
PMID- 10695044
TI - [Characteristics of "Avaxim" hepatitis A vaccine produced by the firm "Pasteur
Merrier" (results of field clinical trials)].
AB - Controlled field clinical trials of Avaxim vaccine from hepatitis A (Pasteur
Merrier-Connot) were carried out in adults and children aged 3-14 years to
evaluate its reactogenicity and antigenic properties. The vaccine was weakly
reactogenic both in adults and children. A single injection of the vaccine
resulted after 1 month in the production of anti-HAV antibodies in 77.4%
initially seronegative adults and 94.5% children. In adults the mean geometrical
titer of antibodies was 95 mIU/ml and in children 165 mIU/ml, which was 5-8 times
higher than the protective titer. These data recommend Avaxim vaccine for
practical public health.
PMID- 10695045
TI - [Induction of baculovirus infection at various stages of ontogenesis of the
silkworm (Ocneria dispar L.)].
AB - The inducibility of baculovirus infection in Ocneria dispar L. of West Siberian
population is studied. The insects are rather stable to induced polyhedrosis.
PMID- 10695046
TI - [On vaccine therapy of chronic urogenital chlamydia infection].
AB - The efficiency of vaccine therapy of a small group of patients with chronic
urogenital chlamydial infection can be regarded as preliminary results. The group
included only patients treated with antibiotics many times without success;
vaccine therapy led to stable cure and elimination of Chlamydia from the
organism. Therefore, vaccine therapy of the above mentioned patient population is
justified.
PMID- 10695047
TI - The true history of the discovery of penicillin, with refutation of the
misinformation in the literature.
AB - In 1928, while investigating variant strains of Staphylococcus aureus, Alexander
Fleming found that a fungus growing near the edge of a culture of S. aureus
produced a substance which had diffused into the medium, lysed the nearest
organisms and thus produced a clear area immediately surrounding the fungus.
Further away was a zone of transparent, degenerate colonies, while those in the
outer zone appeared healthy. This culture plate was one of several left on his
laboratory bench at room temperature while he was away on holiday. On his return,
he noticed the difference on this plate from the usual contaminated plate. He
cultivated the fungus, Penicillium notatum, which he was initially informed was
P. rubrum, and called the soluble extract penicillin. It cured local infections
but, at the time, could not be purified to treat systemic infections. Many
authors have criticized apparent failings in Fleming. This paper catalogs the
criticisms and provides evidence to refute them.
PMID- 10695048
TI - Chlamydia trachomatis infection in pregnancy: risk factor for an adverse outcome.
AB - A cohort of 122 pregnant women attending the hospital antenatal clinic in
northern India were studied to determine the prevalence of genital chlamydial
infection, and any adverse effect on the pregnancy. Endocervical swabs were taken
at > 12 weeks of pregnancy and cultured for Chlamydia trachomatis. Twenty-six
(21.3%) pregnant women were found to be infected with C. trachomatis. The mean
age, gravidity and parity were significantly higher (25.03 vs 23.6 years, 1.88 vs
1.72 and 0.92 vs 0.68 respectively [P < 0.005]) in women from whom C. trachomatis
was isolated. Follow-up was possible in 87 women who delivered in the hospital.
There was increased incidence of still-birth, prematurity and low birth-weight in
the C. trachomatis-positive women (16.6% vs 5.7%, 26.6% vs 18.4% and 26.6% vs
23.0%), and these differences were statistically significant (P < 0.5, P < 0.5
and P < 0.05 respectively). The results suggest a definite need for C.
trachomatis screening on a wider scale, both in different risk groups of
asymptomatic antenatal women and in neonates, to confirm these findings.
PMID- 10695049
TI - Characterisation of yeasts implicated in vulvovaginal candidosis in Irish women.
AB - High-vaginal swabs were taken from 98 women attending a genitourinary clinic in
Dublin city who presented with symptoms of vaginitis. Twenty-eight (28.6%) proved
culture-positive for yeasts. Candida albicans was isolated from 26 of the yeast
positive patients and Candida glabrata and Candida tropicalis were isolated from
a further two patients. Two patients were colonized by two yeasts simultaneously
(C. albicans and Candida lucitaniae, and C. albicans and Candida krusei). Yeasts
were characterised on the basis of their adherence ability, extracellular enzyme
production and resistance to antifungal agents. All C. albicans isolates
demonstrated high adherence abilities to buccal epithelial cells, but produced
relatively low levels of phospholipase and acid proteinase. The non-C. albicans
isolates demonstrated low levels of adherence, but no extracellular enzyme
production was detected. Isolates were most sensitive to the polyenes
amphotericin B and nystatin but a large proportion (50%) of C. albicans isolates
were resistant to clotrimazole, which is an important agent in the treatment of
vulvovaginal candidosis.
PMID- 10695050
TI - Enteric pathogens and their isolation at a cancer hospital in Pakistan.
AB - Diarrhoeal diseases remain a major cause of mortality and morbidity in developing
countries. However, due to lack of funds, supply problems and some inexperience,
some laboratories have difficulty identifying a causative agent in stool samples.
In the year following the opening of the Shaukat Khanum Memorial Cancer Hospital
and Research Centre in Lahore, Pakistan, the microbiology department had not
isolated a single enteric pathogen. From January 1996, new culture techniques
were introduced, with a resulting increase (10%) in identification of these
pathogens. In addition, the introduction of formol-ether concentration made a
significant contribution to the number of intestinal parasites seen. This report
demonstrates how simple microbiology methods made a difference to the running of
the department and, ultimately, to the patients.
PMID- 10695051
TI - Dietary tomato and grape pomace in rats: effect on lipids in serum and liver, and
on antioxidant status.
AB - Addition of tomato and grape pomace to the cholesterol (0.3%) diet of male Wistar
rats produced a dose-dependent effect. During the eight-week experiment, 5%
pomace showed no effect; however, 15% pomace reduced serum cholesterol levels
from 4.4 mmol/L to 2.5 mmol/L (tomato) and 2.0 mmol/L (grape). At a concentration
of 15%, both tomato and grape pomace induced a redistribution of cholesterol in
lipoproteins, resulting in a pronounced anti-atherogenic profile: reduced
cholesterol concentration in very-low-density lipoprotein (VDL) (24% [tomato],
50% [grape]) and low-density lipoprotein (LDL) (3-fold, 3.6-fold). In addition,
grape pomace increased cholesterol concentration in high-density lipoprotein
(HDL) by 26%. Both types of pomace reduced the VLDL and LDL contribution to
cholesterol transport in favour of HDL. Grape pomace (15%) produced a significant
reduction in cholesterol and triacylglycerols in the liver and serum
respectively. Diets containing tomato and grape pomace reduced plasma levels of
conjugated dienes by 30-50%, and showed a tendency towards higher superoxide
dismutase and glutathione peroxidase activity in the liver.
PMID- 10695052
TI - Expression of Bcl-2 family proteins during chemotherapeutic agents-induced
apoptosis in the hepatoblastoma HepG2 cell line.
AB - This study demonstrates that two anticancer drugs, taxol and doxorubicin (Dox),
can kill human hepatoblastoma HepG2 cells in a dose-dependent manner via the
induction of apoptosis. Characteristic events, including externalization of
phosphatidylserine, cytoplasmic shrinkage, chromatin condensation and DNA
degradation, were observed in a large majority of the drug-treated cells. DNA
fragmentation showed that a ladder of DNA fragments of approximately 200 bp
multiples was observed in taxol-treated, but not in Dox-treated, cells. In
addition, the expression patterns of Bcl-2 family members during taxol or Dox
treatment were investigated. Results from Western blot analysis indicated that
HepG2 cells did not express either the death repressor Bcl-2, or the death
promoters Bcl-XS and Bax. However, during the apoptotic process one death
repressor, Bcl-XL, and two death promoters, Bak and Bad, were expressed. The
expression levels of Bcl-XL and Bak remained unchanged, whereas the level of Bad
was down-regulated. As the ratio between death repressors and death promoters in
the Bcl-2 family will determine the sensitivity of cells to apoptotic stimuli,
the findings suggest that the changed expression patterns of Bcl-2 family
proteins caused by anticancer drugs in liver cancer cells may be involved in
chemoresistance.
PMID- 10695053
TI - Recombinant and tissue extract thromboplastins for determination of international
normalised ratio in over-anticoagulated patients.
AB - The international normalised ratio (INR)/international sensitivity index (ISI)
system is established for calibration of thromboplastins for laboratory
monitoring of oral anticoagulant therapy. The calibration procedure employs
patients stabilised on oral anticoagulants, and is therefore validated for
patients within the therapeutic range. For practical reasons, the system is used
for patients at all levels of therapy, including over-anticoagulated patients
with particularly low levels of factors II, VII and X. We studied patients within
and above the therapeutic range, using a thromboplastin containing recombinant
human tissue factor (Innovin) and two tissue extract thromboplastins. In samples
with INRs from 2.0 to 4.0, there was good agreement between results obtained with
the three systems (mean INRs within 4% of each other). In patients with INRs >
4.0, results with a human placental extract reagent (Thromborel S) were similar
to those obtained with a rabbit brain thromboplastin (IL PT Fib Hs Plus); mean
INRs were 6.30 and 6.32 respectively (not significant). Results with Innovin
(mean INR: 7.67) were significantly (P < 0.001) greater (on average by 22%) than
those obtained with the other two materials. The discrepancy between results with
different reagents negatively correlated with factor VII levels. Thus, the lower
the factor VII level, the greater was the discrepancy between INRs. Unexpectedly,
there was a positive correlation between factor V level and the difference
between INRs with different reagents. Thus, the higher the factor V level, the
greater was the discrepancy between INRs. The effect of these differences at
higher INRs on patient management is unknown, but the recently revised UK
guidelines recommend that management of these patients should be influenced by
clinical factors, reducing the relative importance of discrepancies between
results obtained with different systems.
PMID- 10695054
TI - Detection of anti-Yta antibodies using a sensitive and specific enzyme-linked
immunosorbent assay.
AB - A specific, sensitive and semi-quantitative enzyme-linked immunosorbent assay
(ELISA) is described to detect anti-Yta antibodies in human serum. Recombinant
acetylcholinesterase (AChE E.C.3.1.1.7) was employed as the coating antigen in
the microtitre plate and horseradish peroxidase (HRP)-conjugated specific
antibody (IgG) was used as the secondary antibody. The method developed showed
excellent sensitivity, detecting a titre > 1 in 600,000 (3.5 ng/mL mouse IgG
protein) for mouse monoclonal (mMAb) anti-AChE antibody. No cross-reaction was
seen with other common blood group antibodies, confirming the specificity of the
method. The recombinant antigen's AChE phenotype was confirmed as Yta, as no
reaction was detected with anti-Ytb-positive sera. The ELISA method correlated
closely with the established serological grading system used routinely in blood
transfusion laboratories.
PMID- 10695055
TI - Malignant melanoma: death by image and ignorance, diagnosis by surgical excision
and laboratory investigation.
AB - Malignant melanoma is now one of the most common cancers in the western world.
Across Europe, the rise in annual incidence is 4-7%. The criteria for clinical
and histological diagnosis are well established; however, an elaborate range of
laboratory investigations can provide valuable supplementary information in
difficult cases. In this essay, we highlight the incidence and impact of
malignant melanoma worldwide, and outline the range of laboratory investigations
that can be performed and are so vital in the diagnosis of problematic cases.
PMID- 10695056
TI - Applications of molecular genotyping to immunohaematology.
AB - The genes encoding 20 of the 23 blood group systems have been cloned and
sequenced. This has allowed the determination of the molecular basis of many
blood group antigens and phenotypes. In this review we outline the basis of the
genetic code, summarise molecular events that give rise to polymorphic antigens
and to blood group phenotypes, and describe how polymerase chain reaction-based
techniques can be applied in the clinical setting.
PMID- 10695057
TI - Health technology assessment in primary and community care.
PMID- 10695058
TI - Supporting doctors, or the beginning of the end for self-regulation?
PMID- 10695059
TI - Validity of symptom and clinical measures of asthma severity for primary
outpatient assessment of adult asthma.
AB - BACKGROUND: Symptom and pulmonary function measures of asthma severity are used
for severity classification in practice guidelines. However, there is limited
methodological evidence in support of their validity and utility. AIM: To
validate initial symptom and forced expiratory volume (FEV1) measures of asthma
severity with the subsequent risks of exacerbations resulting in emergency room
(ER) visits, hospitalisation, and sickness absence from work. In addition,
symptom-based measures of change in asthma severity were also evaluated against
the concurrent risks of asthma exacerbations. METHOD: A cohort of 361 adult
asthmatic patients in general outpatient clinics was studied. At initial
interview, frequencies of asthmatic symptoms and nocturnal exacerbations, FEV1,
and a severity score combining these measures, were recorded. At re-interview in
the third year, the frequencies of asthma exacerbations resulting in ER visits,
hospitalisation, and sickness absence, and a self-assessed global measure of
change in severity and serially-assessed change in symptom frequencies, were
measured. RESULTS: All individual symptom and FEV1 measures were strongly related
to the subsequent risks of ER visits, hospitalisation, and sick absence. A
severity score of more than 3 (moderate to severe asthma) and self-assessed
change in asthma severity were most strongly and significantly associated with
greatly increased risks of all outcomes. Individual symptoms and FEV1 measures
alone did not show high sensitivities, but the severity score combining these
measures gave much more satisfactory validity. Perhaps not surprisingly, self
assessed change in asthma appeared to give the most satisfactory validity.
CONCLUSION: These results support the validity and clinical utility of a simple
clinical score based on symptom and FEV1 measures, and self-assessed measure of
change in severity, for risk classification in contemporary clinical practice
guidelines.
PMID- 10695060
TI - In-practice evaluation of whole-blood Helicobacter pylori test: its usefulness in
detecting peptic ulcer disease.
AB - BACKGROUND: Approximately 10% of patients presenting with dyspepsia to the
general practitioner have peptic ulcers; the large majority of which are related
to infection with Helicobactor pylori. Office-based tests for H. pylori detection
are generally validated and evaluated in selected patient groups. AIM: To
evaluate the clinical effectiveness of a whole-blood serology test for infection
with Helicobacter pylori in detecting peptic ulcer disease (PUD) in daily general
practice. METHOD: A descriptive study of 171 primary care dyspepsia patients
selected for open-access endoscopy in primary care and aged between 18 and 75
years, in 92 general practices in central, southern, and eastern parts of the
Netherlands. H. pylori status was assessed using the BM-test Helicobacter pylori,
which is identical to the Helisal test. Dyspepsia severity score was measured
using a validated symptom score. Symptom characteristics and probability of
relevant disease were assessed by the general practitioner. Endoscopy was carried
out in local hospitals. Diagnostic outcome of both endoscopy and H. pylori
reference test was supplied by local specialists. The BM-test was evaluated
against endoscopic results. RESULTS: A high number (61.8%) of false-negative BM
tests resulted in a low sensitivity (95% confidence interval [CI] = 48-75%) for
detection of H. pylori infection. Only 12 out of 32 patients with PUD had a
positive BM-test, resulting in a positive likelihood ratio (LR) for PUD of 1.41
and a negative LR of 0.85. CONCLUSIONS: This study confirms the relatively poor
performance of the BM-test in daily general practice, and shows the limited
diagnostic value of H. pylori office-tests for detecting PUD in primary care. The
discriminative value of the test result is too small to support either a 'test
and-endoscope' of a 'test-and-treat' strategy in general practice.
PMID- 10695061
TI - Needs assessment in primary care: general practitioners' perceptions and
implications for the future.
AB - BACKGROUND: Health needs assessment can guide the appropriate shift to primary
care by identifying the most effective and efficient resource allocation to meet
the needs of populations. Assessing health care needs will be a continuing
challenge for primary care trusts in Scotland (or equivalent groups in other
parts of the United Kingdom); however, lessons must be learned from the
experience of needs assessment that followed the 'internal market' reforms of the
1990s. AIM: To examine general practitioners' (GPs') awareness and experience of
needs assessment, to identify barriers to needs assessment in primary care, and
to ascertain how better progress might be made in the future. METHOD: A postal
questionnaire survey of 1777 Scottish GPs (a one-in-two sample) was combined with
a semistructured interview survey of 'lead' GPs from a random sample of 64
mainland Scottish practices between May and August 1996. RESULTS: Sixty-five per
cent (1154) of GPs responded to the questionnaire, of which 54% (965) were
completed. Over 73% (47) of interviews were completed. Most GPs were unfamiliar
with the concept of needs assessment and there was no evidence that needs
assessment had influenced commissioning decisions. Most GPs argued that it was
not a 'core' activity and that they lacked training in the relevant skills. While
the attitude of the majority was indifferent, cynical, and sometimes hostile, a
minority, comprising mostly younger fundholders, was more enthusiastic about
needs assessment. CONCLUSION: The motivation and attitude of the majority of GPs
present a barrier to needs assessment in primary care. GPs will require more
resources and training if they are to undertake this responsibility. Most GPs
believe than incentives (financial or organisational) will be necessary. Primary
care trusts and equivalent structures should be aware of these attitudes as they
seek to establish plans based on estimates of population needs in defined
locations.
PMID- 10695062
TI - Eating disordered patients: personality, alexithymia, and implications for
primary care.
AB - BACKGROUND: Eating disorders are becoming more apparent in primary care.
Descriptions of character traits related to people with eating disorders are
rarely reported in the primary care literature and there is little awareness of
the implications of alexithymia--a concept that defines the inability to identify
or express emotion. We hypothesised that many individuals with active eating
disorders have alexithymic traits and a tendency to somatize their distress. AIM:
To analyse the character traits and degree of alexithymia of a selected group of
women with active eating disorders and in recovery, and to recommend responses by
members of the primary care team that might meet the needs of such individuals.
METHOD: Letters were sent to 200 female members of the Eating Disorders
Association who had agreed to participate in research. Seventy-nine women
volunteered to complete four postal questionnaires. This gave a response rate of
38.5%. Responders were categorised into three groups--anorexic, bulimic, and
recovered--using the criteria of the Eating Disorders Inventory (EDI-2). The
results of the 16PF5 Personality Inventory (16PF5) and the Toronto Alexithymia
Scale (TAS-20) were analysed using one-way analysis of variance (ANOVA) and
correlated using Pearson's correlation. A biographical questionnaire was also
completed. RESULTS: In all three subgroups, high scores were achieved on the
16PF5 on 'apprehension and social sensitivity', while there were significant
differences in the scores for 'privateness': a scale that measures the ability to
talk about feelings and confide in others. On the TAS-20, 65% of the anorexic and
83% of the bulimic group scored in the alexithymic range compared with 33% of the
recovered group. There was a significant negative correlation between alexithymia
and social skills such as 'social and emotional expressivity' on the 16PF5.
CONCLUSION: The results of this study emphasise the difference between those with
active eating disorders who achieved high scores for privacy, introversion, and
alexithymia, and those who have recovered. These character traits give potential
helpers an important indication of the areas that can both block and facilitate
recovery, and they act as a reminder that the presenting symptoms in eating
disorders and other psychosomatic conditions are the outward presentation of
internal conflict. It is suggested that effective screening and needs assessment
will facilitate a more appropriate and prompt therapeutic response. This may be
provided in the primary care setting where appropriate training has occurred.
PMID- 10695063
TI - Influenza vaccination in asthma: a primary care experience.
AB - BACKGROUND: Despite the recommendation of the Department of Health that patients
with asthma receive annual vaccination against influenza, uptake remains
unsatisfactory with many patients suspicious that vaccination is harmful. AIM: To
examine the effect of influenza vaccination on asthmatic patients typical of a
general practice setting. METHOD: A multicentre study with 56 patients
participating from 14 practices in England and Scotland. Patients completed peak
expiratory flow rate (PEFR) and symptom diaries for two weeks before and two
weeks after influenza vaccination. RESULTS: A non-significant fall in baseline
PEFR of 10.5 l/min, from an average of 431.5 l/min, was observed after influenza
vaccination, representing a 2% change from baseline. A significant increase in
night time reliever use of 0.17 puffs per night (P < 0.01) was found. Non
significant increases in number of nights per week with sleep disturbed due to
asthma, severity of night-time and day-time symptoms, and day-time reliever use
were also noted. CONCLUSION: Influenza is an important cause of morbidity and
mortality in asthmatics. This study confirms the safety of influenza vaccination
in patients with asthma typical of those seen in primary care. General
practitioners need not hesitate in recommending this valuable intervention to
their asthmatic patients and should consider ways in which uptake can be
improved.
PMID- 10695064
TI - Do practice-based preventive child health services affect the use of hospitals? A
cross-sectional study of hospital use by children in east London.
AB - BACKGROUND: Acute paediatric admissions have risen steadily over the past 20
years. During the same period, practice-based child health clinics have
increased, although provision is less common in areas of deprivation where
hospital use is greatest. AIM: To investigate the contribution of practice-based,
preventive child health services to rates of hospital utilisation in children
under five years of age. METHOD: A cross-sectional retrospective study examining
practice variations in paediatric acute admissions, outpatient referrals, and
accident and emergency (A&E) department attendances in the East London and the
City Health authority, including all 164 practices in the inner-city boroughs of
Hackney, Newham, Tower Hamlets, and the City of London. The main outcome measures
were practice-based paediatric hospital attendance rates, for discrete age and
sex bands, for the year to 31 March 1996. RESULTS: Hospital use varied with age
and sex, with the rates being highest for the youngest children and for boys. The
median A&E attendance rate (including reattendances) for boys up to one year of
age was 897 per thousand children per practice. In east London, 62% of practices
are registered for child health surveillance and 71% provide a child health
clinic. Practice approval for child health surveillance, and the provision of
child health clinics, did not account for differences between practices in
hospital use, but proportionally greater health visiting hours were significantly
related to lower rates of emergency hospital admission by young children.
Multivariate analyses revealed that up to 23% of the variation between practice
admission rates could be explained by health visiting hours. CONCLUSIONS: We
found significant associations between the amount of health visiting time
available to the practice population and rates of acute admission and outpatient
referral among children up to five years of age. These findings suggest that
increasing health visitor provision could contribute to lower paediatric
emergency admission and outpatient referral rates. A small change would have a
significant effect, particularly among the youngest children, given that during
the study year 10,000 children under two years of age in east London were either
admitted or referred to hospital.
PMID- 10695065
TI - Management confidence and decisions to refer to hospital of GP registrars and
their trainers working out-of-hours.
AB - BACKGROUND: There is concern about the educational impact and possible stress on
registrars of new out-of-hours co-operatives. AIM: To compare the confidence in
managing out-of-hours problems of registrars in traditional on-call rotas and co
operatives with that of their trainers. To determine how frequently registrars
discussed problems out-of-hours with their trainers, and to compare the referral
pattern of registrars with their trainers out-of-hours. METHOD: Analysis of log
diaries of out-of-hours experiences kept by registrars and trainers over two, two
month periods in winter and summer. RESULTS: Thirty registrars (out of a possible
51) and 34 (out of a possible 52) trainers took part in the winter, and 18
registrars and 29 trainers in the summer. Registrars were confident in their
management, and their confidence increased over the year (59% versus 72%
difference = 12%, 95% CI = 6% to 20% for very confident). Registrars varied in
their discussion of problems with trainers. When 'a little worried' they
discussed their management 30 out of 53 times (57%); if 'very confident', 36 out
of 576 times (6%). Registrars during the summer segment of the study referred
more frequently to hospital than trainers (20% versus 10% difference = 10%, 95%
CI = 3% to 17%. Registrars in traditional rotas recorded a slightly higher but
statistically insignificant level of confidence in their management of problems
than those registrars in cooperatives. CONCLUSIONS: While many registrars are
confident in their work and are using their trainer for information
appropriately, some are not. Registrars may be referring to hospital at a much
higher rate than their trainers. More research is required to confirm and further
explore these findings.
PMID- 10695066
TI - Doctor-staffed ambulance helicopters: to what extent can the general practitioner
replace the anaesthesiologist?
AB - During two years, a rural ambulance helicopter programme saved 41 patients'
lives. In 29 of these patients, the decisive medical interventions were carried
out by the flight anaesthesiologist before reaching the hospital. We asked an
expert panel to assess whether these interventions could have been carried out by
a general practitioner (GP). This was the case for 17 (59%) of the 29 patients,
while more advances skills, equipment or drugs were needed for 11 (38%). Among
these 11, three patients would probably have died without the interventions. We
conclude that GPs can manage a majority of life saving missions for a rural
ambulance helicopter programme, but the lack of a flight anaesthesiologist may
imply substantial health losses for a few patients.
PMID- 10695067
TI - Can dietary assessment in general practice target patients with unhealthy diets?
AB - Diet is important in the aetiology and management of many conditions in primary
care. Although valid dietary assessment is required for both clinical work and
research, no dietary assessment instruments have been validated among patients
seen in primary care. A range of simple self-completion dietary assessment
questionnaires and established research instruments were compared with an
accepted reference standard, a seven-day weighed record, in 111 subjects assessed
in a practice nurse-run treatment room. Simple self-completion tools based on
food groups and portion sizes perform as well (likelihood ratios for a positive
test = 2 to 3) as much more time-consuming instruments. The error in using such
instruments is comparable with the error of the standard itself. There is little
justification for using time-consuming dietary assessment questionnaires, since
simple tools are accurate enough to be clinically useful--to allow practice
nurses to target patients for counselling and waste less time on inappropriate
counselling--and also useful for research.
PMID- 10695068
TI - To what extent are practices 'paperless' and what are the constraints to them
becoming more so?
AB - A questionnaire was sent to all practice managers in Wessex in June 1997 to
assess to what extent practices had stopped relying on paper records in the
consultation. Practices that solely used computer records in the consultation
('noteless') did not necessarily consider themselves 'paperless'. Following a
recent declaration that all practices should be using an Electronic Health Record
by March 2005, the obstacles to this move were investigated and some differences
in the way the 'noteless' and 'paperless' groups used computers were identified.
PMID- 10695069
TI - Can methadone maintenance for heroin-dependent patients retained in general
practice reduce criminal conviction rates and time spent in prison?
AB - A retrospective analysis was made of the criminal records of 57 patients
successfully retained in methadone maintenance at two general practices in
Sheffield. Their criminal conviction rates and time spent in prison per year were
compared for the periods before and after the start of their methadone programme.
Overall, patients retained on methadone programmes in the general practices
studied had significantly fewer convictions and cautions, and spent significantly
less time in prison than they had before the start of treatment.
PMID- 10695070
TI - Diagnosis of patients with chronic heart failure in primary care: usefulness of
history, examination, and investigations.
AB - Chronic heart failure is a common clinical syndrome that may have different
causes. Its incidence and prevalence are predicted to rise substantially over the
next 10 years. There are therefore major consequences for resource provision,
especially in primary care, where most patients are managed. Chronic heart
failure is a serious condition with high morbidity and mortality. There is good
evidence to show that treatment with angiotensin-converting enzyme (ACE)
inhibitors in patients with left ventricular systolic dysfunction improves
symptoms and signs, slows progression of heart failure, reduces hospitalisation
rates, and improves survival. Despite this evidence, primary care studies show
that patients with heart failure are incorrectly diagnosed and inadequately
treated. Most patients present in general practice, and because effective
treatment relies on a correct diagnosis, this is a key step in the appropriate
management of heart failure. The aim of this paper is to review the evidence
about the usefulness of signs, symptoms, and investigations in diagnosing heart
failure in primary care. To identify relevant studies for this review, four
strategies were used: a MEDLINE search from 1993 to January 1998 using the
diagnosis search filter; a MEDLINE search from 1993 to January 1998 using the
guideline search filter to locate published heart failure guidelines; a search
for review articles in the Cochrane Library; and a check of references in the
studies identified. The search terms included MeSH terms and the keywords 'heart
failure' and 'diagnosis'. All searches were limited to humans and English
language articles. Studies were included in this review on the basis of quality
and relevance to primary care. The review shows that symptoms and signs are
important because they alert clinicians to the possibility of heart failure as a
diagnosis. However, they are not sufficiently specific for confirming left
ventricular systolic dysfunction. From the evidence available, a patient with
suspected heart failure must have objective tests to confirm the diagnosis. These
should include an electrocardiogram and, ideally, an echocardiogram. Further
research is also needed on the usefulness of signs and symptoms in primary care,
as most studies of heart failure have been conducted in secondary care.
PMID- 10695072
TI - Supporting practice-based audit.
PMID- 10695071
TI - What do GPs need to know? The use of knowledge in general practice consultations.
AB - In the course of the consultation in primary care, the general practitioner
integrates knowledge of different types that are drawn from different sources. As
a consequence of the way practitioners develop expertise, this use of knowledge
is often hidden from the conscious mind of the practitioner and often hidden from
direct observation. On the other hand, understanding of this use of knowledge is
crucial to several necessary developments of the profession of general practice.
A method involving collaboration between researcher and practitioner sheds new
light on this knowledge-in-use.
PMID- 10695073
TI - The reform of GP training.
PMID- 10695074
TI - Providing health care for the homeless.
PMID- 10695075
TI - Recruitment and retention of GPs in the UK.
PMID- 10695076
TI - Epidemiology of intensive care medicine: supply versus demand.
AB - Developments in hospital medicine combined with social and demographic changes
are likely to increase the need for intensive care services at a time when cost
containment and cost-efficacy are the main items on the political agenda. This
will exaggerate the supply-demand outcome mismatch unless the problem is
approached in a constructive manner by clinicians, managers and politicians. More
resources will be required for intensive care, but these must be better targeted
and more efficiently employed. Opportunities for prevention should be explored,
with intensive care being given a pro-active rather than a re-active role.
Intensive care clinicians should understand that this expanded role cannot be
achieved if they are willing only to accept responsibility for patient care after
the patient has been admitted to the ICU. Clinicians and managers should develop
methods for linking the various disciplines which contribute to emergency care,
to form an acute care framework within the hospital. Research into the factors
which determine risk of critical illness should be combined with enhanced medical
and nursing training in intensive care, accompanied by an expansion in resources
for intermediate and high dependency care in countries like the UK where there is
clear evidence of rationing.
PMID- 10695077
TI - Inflammatory cell activation in sepsis.
AB - The body relies for protection on an effective inflammatory response. To sustain
an armoury of inflammatory cells in a state of permanent activation would be
impossible and a system whereby such cells can be rapidly activated is,
therefore, employed. Upon transition from the resting to activated state
inflammatory cells perform multiple defensive functions and are then removed,
limiting the duration of inflammation. Neutrophils are the major circulating
inflammatory cells but macrophages exert a more powerful regulatory effect. If
the inflammatory response is inadequate there is a risk of overwhelming sepsis.
By contrast, an unregulated response can lead to systemic inflammation and
consequent multiple organ damage. This review focuses on the mechanisms whereby
inflammatory cells are activated, how the regulatory system may misfunction and
how it may in the future be manipulated to therapeutic advantage.
PMID- 10695078
TI - The role of the endothelium in modulating vascular control in sepsis and related
conditions.
AB - The majority of deaths amongst critically ill patients requiring intensive care
are attributable to sepsis and its sequelae: septic shock, the systemic
inflammatory response syndrome (SIRS) and the acute respiratory distress syndrome
(ARDS). Patients within the ICU who develop these conditions and fail to survive
succumb to multiple organ dysfunction syndrome (MODS). ARDS is considered to be
the pulmonary component of MODS and is characterized by pulmonary hypertension,
often in the setting of systemic hypotension. Endothelial cells, normally
responsible for modulating vascular tone, becomes dysfunctional in sepsis. Pro
thrombotic, pro-inflammatory and vasoactive mediators are released including
nitric oxide (NO), endothelins (ETs) and products of cyclo-oxygenase metabolism.
It is probably the disordered production of these mediators in vascular beds that
results in MODS. This review highlights recent research in this area with
particular emphasis on possible therapeutic options.
PMID- 10695079
TI - Redox imbalance in the critically ill.
AB - The majority of deaths amongst critically ill patients requiring intensive care
are attributable to sepsis and its sequelae: septic shock, the systemic
inflammatory response syndrome (SIRS) and the acute respiratory distress syndrome
(ARDS). Clinically, sepsis/SIRS and ARDS are characterised by disordered vascular
control, manifest as systemic hypotension and peripheral vasodilation refractory
to intravascular volume resuscitation and vasopressor therapy; and pulmonary
hypertension. Experimental and clinical evidence demonstrates that these patients
suffer from severe oxidative stress. Thus, our own and other groups have shown
that the vascular pathology of sepsis/SIRS and ARDS is initiated through the
uncontrolled production of reactive oxygen (ROS) and reactive nitrogen species
(RNS) which modulate inflammatory cell adhesion and cause direct injury to
endothelium (Fig. 1).
PMID- 10695080
TI - Sedation and analgesia.
AB - Sedation is a process of soothing. The concept of the ideal level of sedation is
controversial and has changed over the last decade. A shift from deep sedation,
often enhanced by muscle relaxants that completely detaches the patient from
their environment, to light sedation rendering the patient sleepy but easily
arousable has been widely accepted. This change in attitude has been brought
about by sophisticated modes of ventilation allowing the ventilator to
synchronize with the patient's own breathing pattern. In addition, the
increasingly recognised adverse effects of over-sedation have contributed to the
reduction in the depth of sedation.
PMID- 10695081
TI - The oxygen trail: tissue oxygenation.
AB - Aerobic cellular respiration depends on the efficient supply of oxygen and
substrate to the mitochondria. There is an oxygen cascade from the environment to
the subcellular environment. Efficient oxygen delivery depends on the coordinated
interaction between the respiratory and circulatory systems. The circulation at
both macro- and microvascular levels is under the control of humoral and neural
factors. There is local autoregulation of flow at the tissue level by metabolic
factors which reflect the energy state of the tissues. The response to hypoxia
involves the activation of cytokines and genetically controlled factors which
maximise capillary perfusion and haemoglobin concentration, and regulate cell
metabolism. The formation of reactive oxygen species under such conditions has a
detrimental effect on the mitochondria with respiratory chain dysfunction,
increased permeability transition, and cell death. This review aims to explore
the mechanisms by which the body attempts to maintain tissue oxygen levels at
conditions optimal for cell survival.
PMID- 10695082
TI - The oxygen trail: measurement.
AB - Tissue hypoxia may be defined as abnormal oxygen utilization such that cells are
experiencing anaerobic metabolism. Tissue hypoxia can be defined biochemically by
low levels of ATP, high levels of NADH, or decreased oxidized cytochrome aa3. It
is possible to measure these biochemical markers in the laboratory setting with,
for example, nuclear magnetic resonance spectroscopy. However, this is not as yet
a clinical option. There is no 'gold standard' for the diagnosis of clinical
hypoxia. We can detect the gross consequences of tissue hypoxia, such as organ
dysfunction and metabolic markers of anaerobic metabolism (e.g. lactic acidosis).
We have also become familiar with the measurement of both global and regional
oxygen dispatch and consumption. However, organ dysfunction and metabolic
acidosis consistent with established tissue hypoxia commonly exists in the
presence of normal and even supra normal global measures of oxygen dispatch and
consumption. Therefore, we should ideally make measurements at the end of the
oxygen trail, i.e. cellular oxygen delivery and effective utilization.
PMID- 10695083
TI - The oxygen trail: the goal.
AB - Over the last 10 years, there have been great advances in knowledge concerning
changes in tissue perfusion and its prognostic implications. Has this translated
into improved patient management? We review the clinical trials that have
deliberately increased tissue oxygen delivery by increasing cardiac output. We
have divided the studies into those that intervene early or those that intervene
late in the course of a patient's illness. Although there are methodological
problems limiting interpretation of the results, we show a combined odds ratio of
a reduction in mortality for the early studies but not for the late studies. We
conclude that a treatment policy whereby oxygen delivery is deliberately
increased improves patient outcome if it is initiated early, prior to the onset
of organ failure.
PMID- 10695084
TI - Ventilatory support in the acute respiratory distress syndrome.
AB - Ventilatory support in the acute respiratory distress syndrome (ARDS) has
undergone considerable transformation in the 1990s. Current approaches include
lung protective techniques which, while attempting to recruit and maintain lung
volume, limit the shear stresses associated with ventilation by avoiding both
alveolar overdistension and cyclical end-expiratory collapse. In addition, gas
exchange targets have been liberalized and ventilatory conduct is much more
tailored to individual pulmonary mechanics. Assessment of the inspiratory volume
pressure (V-P) curve provides information which can direct ventilator settings.
Recent information from clinical trials has provided new insights into
appropriate ventilatory modification and set the foundation for future clinical
investigations.
PMID- 10695085
TI - Non-ventilatory treatment of acute hypoxic respiratory failure.
AB - Severe acute hypoxic respiratory failure is uncommon but often fatal. Standard
treatment involves high inspired oxygen concentrations, mechanical ventilation
and positive end-expiratory pressure. Many other interventions have been used in
parallel with conventional treatment or as rescue therapy when it fails,
including extracorporeal gas exchange, prone positioning, inhaled vasodilators,
exogenous surfactants and drugs which modify the inflammatory process. Nearly all
these treatments improve arterial oxygenation or markers of lung injury. However,
the relationship between oxygenation and survival in acute hypoxaemic respiratory
failure is not established, so improved oxygenation cannot be used as a surrogate
for survival. Randomised controlled trials are, therefore, needed to assess the
effects of these treatments on mortality. In such trials, extracorporeal
oxygenation and extracorporeal carbon dioxide elimination, surfactant, early
methylprednisolone, and prostaglandin E1 offer no survival advantage over
conventional therapy. Prophylactic ketoconazole and pentoxifylline appear to
improve mortality in small studies in surgical and oncology patients
respectively, and methylprednisolone improves mortality and morbidity in
unresolving disease.
PMID- 10695086
TI - Manipulating the metabolic response to injury.
AB - In this short review we will concentrate on just one of the features of the
metabolic response to injury (classified as accidental trauma, injury or sepsis)
which are collectively known as the 'flow' phase. These include an increase in
energy expenditure (hypermetabolism), changes in substrate utilisation (insulin
resistance) and the focus of this chapter muscle wasting or catabolism. It is
recognised that the three features are interrelated, for example insulin is
believed to be an important factor in controlling amino acid flux in skeletal
muscle and increasing environmental temperature which may reduce flow phase
hypermetabolism has been shown to reduce postoperative nitrogen excretion (a
marker of protein catabolism). However, we will concentrate on muscle wasting and
refer the reader to other reviews on insulin resistance and metabolic rate.
PMID- 10695087
TI - The gastrointestinal tract as a barrier in sepsis.
AB - The gastrointestinal tract is an organ of digestion and absorption which is
metabolically active and has specific nutrient requirements. In health, it has an
additional function as a major barrier, protecting the body from harmful
intraluminal pathogens and large antigenic molecules. In disease states, such as
sepsis when the mucosal barrier is compromised, micro-organisms and their toxic
products gain access to the portal and systemic circulations producing
deleterious effects. Under these circumstances, systemic inflammatory response
syndrome (SIRS) and multiple organ dysfunction syndrome (MODS) develop leading to
deterioration and death of the patient in the intensive care unit. Therapeutic
strategies for such patients in the intensive care unit aim to support general
immune function and maintain the structure and function of the gastrointestinal
tract. For these therapies to be successful, the underlying septic or necrotic
focus must be ablated using appropriate surgical or other invasive techniques.
PMID- 10695088
TI - Adjunctive therapy in sepsis: a critical analysis of the clinical trial
programme.
AB - Despite intensive efforts, the development of novel drugs for the treatment of
sepsis has proved to be extremely difficult. A large number of clinical trials
have ended in failure. A critical analysis of this record suggests that there is
no single reason for these problems. Rather, the explanation lies in part with
unexpected failures in the drugs themselves, and in part with the difficulties of
trial design in this particular group of patients. In future, trials in this area
are likely to be more highly focused, with even stricter protocol definitions to
try and ensure a homogeneous patient population.
PMID- 10695089
TI - Cerebral protection in severe brain injury: physiological determinants of outcome
and their optimisation.
AB - The primary role of intensive care in acute head injury lies in the prevention,
detection and reversal of secondary neuronal injury. The maintenance of optimal
systemic and cerebrovascular physiology can substantially contribute to these
aims. There is, however, a role for novel neuroprotective interventions, many of
which are currently under investigation.
PMID- 10695090
TI - Antibacterial resistance in the intensive care unit: mechanisms and management.
AB - The incidence of multiple antimicrobial resistance of bacteria which cause
infections in the intensive care unit is increasing. These include methicillin
resistant Staphylococcus aureus and vancomycin-resistant enterococci, penicillin
resistant Streptococcus pneumoniae and cephalosporin and quinolone resistant
coliforms. More recently, pan antibiotic resistant coliforms, including
carbapenems, have emerged. The rapidity of emergence of these multiple antibiotic
resistant organisms is not being reflected by the same rate of development of new
antimicrobial agents. It is, therefore, conceivable that patients with serious
infections will soon no longer be treatable with currently available
antimicrobials. Strict management of antibiotic policies and surveillance
programmes for multiple resistant organisms, together with infection control
procedures, need to be implemented and continuously audited. As intensive care
units provide a nidus of infection for other areas within hospitals, this is
critically important for prevention of further spread and selection of these
resistant bacteria.
PMID- 10695091
TI - Red blood cell substitutes: fluorocarbon emulsions and haemoglobin solutions.
AB - The problems posed by transfusion of homologous blood have led to the development
of substances able to replace the gas transporting properties of blood.
Perfluorocarbons (PFCs) emulsions and modified haemoglobin (Hb) solutions have
been developed for this goal and are now tested in clinical assays. PFCs are
synthetic fluorinated hydrocarbons, capable of dissolving large quantities of
oxygen (O2; without binding) at high inspired concentrations of O2, and of
delivering this O2 to the tissues. They are administered as emulsions containing
particles with a diameter of approximately 0.2 micron, capable of entering the
microcirculation. They are eliminated unchanged by the lungs within several days.
Fluosol-DA 20% was the first PFC emulsion used in clinical practice. Currently,
Oxygent, a second generation PFC emulsion, is being evaluated in clinical
studies. The PFCs are not blood substitutes, but rather a means to ensure tissue
oxygenation during extreme haemodilution. Solutions of free Hb do not have the
antigenic characteristics of the blood groups, and do not require compatibility
testing. They are fully saturated with O2 at ambient FiO2. The Hbs used are
derived from either human or bovine sources, or via recombinant DNA technology.
In order to maintain satisfactory intravascular half-life and O2 affinity, the Hb
molecules are modified by adding internal crosslinks, by polymerization, and/or
by encapsulation. After promising animal studies, several of these modified Hb
solutions are now being studied in Phase III clinical trials. Among them,
diaspirin cross-linked haemoglobin (DCLHb) has been used in cardiac and
orthopaedic surgery, and for resuscitation of traffic accident victims. The
initial results of multicentre trials are now being analysed.
PMID- 10695092
TI - Medicines cheaper over the counter. May 1999.
PMID- 10695093
TI - Erectile dysfunction--the right to be treated.
PMID- 10695094
TI - Efficacy of twice-daily amoxycillin/clavulanate in lower respiratory tract
infections.
AB - In this double-blind, double-dummy study, 324 patients with clinical evidence of
community-acquired pneumonia (CAP) or an acute exacerbation of chronic bronchitis
were randomly assigned to receive 10 days' treatment with either
amoxycillin/clavulanate 875/125 mg twice daily or amoxycillin/clavulanate 500/125
mg three times daily. At the end of therapy, clinical success rates were 92.4%
for the twice daily regimen and 94.2% for the three times daily regimen. There
was no statistically significant difference between treatments (p = 0.647) and
the 95% confidence interval around the treatment difference indicated that the
two treatments were equivalent. Treatment equivalence was also confirmed at
follow-up, four weeks after the end of treatment. Both regimens were well
tolerated. In conclusion, amoxycillin/clavulanate 875/125 mg twice daily is as
effective as amoxycillin/clavulanate 500/125 mg three times daily for the
treatment of community-acquired lower respiratory tract infections and could
improve patient compliance.
PMID- 10695095
TI - Switch to non-CFC inhaled corticosteroids: a comparative efficacy study of HFA
BDP and CFC-BDP metered-dose inhalers.
AB - Inhaled corticosteroids, such as beclomethasone dipropionate (BDP), recommended
for the treatment of persistent, mild, moderate, or severe asthma, have
traditionally been administered via chlorofluorocarbon (CFC) propellant. The
imminent phasing out of CFCs from pharmaceutical preparations due to the Montreal
Protocol means patients will have to switch to a CFC-free alternative. One such
preparation is hydrofluoroalkane-BDP (HFA-BDP), a press-and-breathe metered-dose
inhaler. This 8-week, open-label, multicentre study assessed asthma control in
patients switching from CFC-BDP to HFA-BDP (QVAR). Patients with asthma,
stabilised on 400-1600 micrograms/day CFC-BDP, were randomised to HFA-BDP (354
patients; 75%) at half their current daily dose of CFC-BDP, or to CFC-BDP (119
patients; 25%). HFA-BDP efficacy was found to be equivalent to that of CFC-BDP in
that no statistically significant difference was observed between the two groups
in the mean change from baseline in a.m. PEF (95% CI within +/- 11 l/min). No
statistically significant differences were observed between the two groups for
increased asthma symptoms or acute asthma episodes. We conclude that asthma
control was maintained over 8 weeks, with few asthma exacerbations, in patients
switching from previous CFC-BDP therapy to HFA-BDP at half the dose.
PMID- 10695096
TI - A comparison of the effects of two modified release preparations of nifedipine
nifedipine retard 10 mg twice daily and nifedipine GITS 20 mg once daily--in the
treatment of mild to moderate hypertension.
AB - A multicentre, randomised, double-blind, cross-over comparison of nifedipine GITS
20 mg once daily and nifedipine retard 10 mg twice daily in 49 patients with mild
to moderate hypertension was conducted. Both treatments resulted in clinically
significant trough blood pressure reductions (nifedipine GITS -10.1/-8.9 mmHg,
nifedipine retard -7.5/-8.2 mmHg). The study demonstrated that nifedipine GITS
was 'at least equivalent' to nifedipine retard in the reduction of trough
diastolic blood pressure (one-sided lower 95% confidence limit, -1.2 mmHg). The
overall incidence of adverse events (nifedipine GITS 25.5%, nifedipine retard
34.0%), as well as the incidences of headache (nifedipine GITS 8.5%, nifedipine
retard 12.8%) and peripheral oedema (nifedipine GITS 2.1%, nifedipine retard
8.5%), was higher with nifedipine retard compared to nifedipine GITS. Nifedipine
GITS 20 mg once daily is 'at least equivalent' to nifedipine retard 10 mg twice
daily in patients with mild to moderate hypertension, as well as being better
tolerated.
PMID- 10695097
TI - A comparison of nimesulide beta cyclodextrin and nimesulide in postoperative
dental pain.
AB - The aim of this study was to assess the efficacy and tolerability of single doses
of nimesulide beta cyclodextrin compared with nimesulide in patients with dental
pain following surgical procedures. This was a randomised, double-blind, between
patient, multicentre study involving 148 outpatients suffering from moderate to
severe pain, who received single doses of either 400 mg nimesulide beta
cyclodextrin or 100 mg nimesulide. The principal criterion for efficacy was pain
intensity assessed on a visual analogue scale (VAS) 15 minutes after drug intake.
Pain intensity was further evaluated 30, 45, 90, 120, 180, 240 and 360 minutes
after dosing. Pain relief was evaluated at the same time points by means of a
categorical scale. The time point of first pain relief, the use of rescue
medication and the global evaluation of efficacy were also recorded. The
reduction in pain intensity was significantly more pronounced in the nimesulide
beta cyclodextrin group at 15, 30, 45 and 60 minutes (p < 0.01). Pain relief was
significantly greater (p < 0.05) and more rapid with nimesulide beta
cyclodextrin. In the patient overall assessment of efficacy, nimesulide beta
cyclodextrin and nimesulide were rated excellent or good by 95% and 92%
respectively; only one patient in the nimesulide beta cyclodextrin group needed
rescue medication. Both study drugs were effective and well tolerated in the
treatment of acute dental pain, with nimesulide beta cyclodextrin showing a
faster onset of analgesic action.
PMID- 10695098
TI - A randomised, double-blind study of itraconazole versus placebo in the treatment
and prevention of oral or oesophageal candidosis in patients with HIV infection.
AB - HIV-infected patients presenting with oral or oesophageal candidosis were
randomised to four weeks treatment with itraconazole 200 mg, followed by
itraconazole or matching placebo for a prophylaxis phase of 24 weeks. Clinical
and mycological evidence of candidosis infection was assessed on a four-weekly
basis. Seventy patients were enrolled, of whom 50 completed 28 days of
itraconazole therapy; 74% (37 patients) were clinically cured and 40% were also
mycologically cured. Fifteen patients were withdrawn for a variety of reasons
including non-compliance, adverse events and the use of excluded medications.
Forty-four patients were enrolled in the prophylactic phase. There were
significantly more relapses of candidosis, and time to candidosis was
significantly shorter in the placebo group than in the itraconazole treated group
(p = 0.0001). Itraconazole 200 mg daily is effective and well tolerated for the
treatment and prevention of oral and oesophageal candidosis in HIV-infected
patients.
PMID- 10695099
TI - Anaesthetic assessment and management of cardiac patients for non-cardiac
surgery. Part 2: Management.
AB - In an earlier article in this journal (June 1999) we discussed the risk that the
presence of cardiac disease poses to patients undergoing non-cardiac surgery. We
outlined factors in the patient's medical history, examination findings and the
value of various tests in arriving at an overall assessment of risk for any given
patient. In this article we concentrate on the management of these patients as
they undergo surgery itself. We shall consider what measures may usefully be
employed in order to minimise the risk of an adverse cardiac event occurring in
the perioperative period.
PMID- 10695100
TI - Polycystic ovarian syndrome: is community care appropriate?
AB - In recent years the complexities and heterogeneity of polycystic ovarian syndrome
(PCOS) have been recognised. Most PCOS sufferers with amenorrhoea, menstrual
dysfunction, hirsutism, acne and infertility can be evaluated and safely managed
in primary care. It is prudent to remember that all women with PCOS are at risk
of insulin resistance and the associated abnormalities of the insulin resistance
syndrome--dyslipidaemia, hypertension, coronary artery disease and diabetes
mellitus.
PMID- 10695101
TI - Erectile dysfunction and cardiovascular disease.
AB - Patients with cardiovascular disease are at increased risk of developing erectile
dysfunction (ED). This may be a consequence of atherosclerosis of the penile
arteries, a reduced cardiac output, or a side-effect of drugs used to reduce
cardiovascular risk factors (particularly beta-blockers, thiazide diuretics and,
occasionally, lipid-lowering drugs). ED is a distressing condition, which often
diminishes the patient's self-esteem, with the potential for damage to his
psychological health and his relationship with his partner and family. When
treating ED, the underlying aetiology should be established by careful
examination and consideration of medical history and concurrent medication. Until
recently, pharmacological treatment options involved intracavernous injections
(alprostadil or moxisylyte) or intraurethral alprostadil. These treatments are
often inconvenient and not well accepted by the patient. The recent introduction
of oral sildenafil promises to revolutionise the treatment of ED. In double
blind, placebo-controlled trials in patients with ED, sildenafil improved
erectile function and quality of life and was well tolerated. ED is a clinically
important complication of cardiovascular disease and should be asked about and
treated accordingly. It is important that effective treatments, including
sildenafil, should be available for treating patients with cardiovascular disease
and ED.
PMID- 10695102
TI - Treatment guidelines for hypercholesterolaemia: time to consider soluble fibre.
AB - Lowering raised serum cholesterol levels is firmly established as an effective
intervention for reducing the mortality and morbidity due to coronary heart
disease (CHD). Recent European and British guidelines for the management of
hypercholesterolaemia recommend dietary modification as first-line therapy.
However, dietary measures alone do not significantly reduce cholesterol levels.
There is ample evidence that soluble fibre, such as ispaghula, lowers cholesterol
and could therefore potentially reduce the risk of CHD. As CHD management costs
spiral upwards, prescribing lipid-lowering drugs for all indicated patients is
not sustainable within current NHS resources. It is suggested that treatment
guidelines be revised to include a soluble fibre product, such as ispaghula, as
an adjunct to diet for patients where diet alone has failed and where lifelong
therapy with lipid-lowering drugs is inappropriate.
PMID- 10695103
TI - The management of young dyspeptic patients in the era of Helicobacter pylori.
AB - The management of young dyspeptic patients remains controversial in the modern
Helicobacter pylori era. The use of non-invasive screening for H. pylori in one
proposed strategy has demonstrated a substantial reduction in the endoscopy
workload by excluding H. pylori negative patients under the age of 45 years with
uncomplicated dyspepsia. An alternative screening strategy proposes a 'test and
treat' approach, with H. pylori positive patients proceeding directly to an
empirical course of eradication therapy. Ednoscopy would be reserved for patients
who failed to respond symptomatically or who were H. pylori negative on intial
screening. At present there are few data available from clinical studies of
putting the 'test and treat' policy into practice. Although there is likely to be
a role for screening young dyspeptic patients for H. pylori in primary care,
subsequent management requires well-planned studies in order to assess the
benefits of any particular strategy.
PMID- 10695104
TI - Risk factor modification extends the benefit of coronary artery revascularisation
procedures.
AB - The management of coronary artery disease has undergone major changes in the past
three decades. Early medical preventive strategies rapidly gave way to surgical
intervention by the end of the 1960s; 10 years later this was supplemented by the
introduction of angioplasty. Both of these approaches offered rapid symptomatic
relief but were dogged by a predisposition to restenosis. While technical
improvements have helped reduce this problem, there is a growing perception that
the imbalance between the enthusiastic adoption of surgical intervention and the
jaundiced neglect of secondary medical prevention needs to be redressed. This can
be achieved without stepping back in time, for, since the 1960s, agents far more
effective in the struggle against ischaemic vascular disease have proven their
worth in the clinical arena. Graft protection following bypass surgery is vital,
but equally important is the need to target the metabolic derangement which
caused the occlusion in the first place. This article reviews medical strategies
designed to add life to coronary artery revascularisation procedures.
PMID- 10695105
TI - Therapeutic approaches to the management of common baldness.
AB - Common baldness or androgenetic alopecia is a universal problem, having affected
both sexes of all races to different extents for as long as mankind has existed.
The progressive androgen dependent hair loss follows specific patterns and is a
physiological process, which may take on disease quality due to psychosocial
compontents. These should be taken into consideration when discussing the several
treatment options available, particularly as a cure cannot be offered. Cosmetic
measures range from back-combing over perms to hairpieces and wigs. Medical
therapies include systemic antiandrogens and topical minoxidil; surgical options
comprise follicular transplantation, scalp reduction and rotation. Before
starting treatment, however, careful consideration should be given to the
differential diagnosis which includes drug-induced hair thinning, anagen
effluvium, diffuse alopecia areata, metabolic disturbances, nutritional
deficiencies and acute as well as chronic telogen effluvium.
PMID- 10695106
TI - The stigma of eating disorders.
AB - Those who suffer from eating disorders often carry the added burden of
stigmatizing attitudes from the lay public and the medical profession. These
attitudes not only restrict the opportunities for effective treatment but also
confer additional handicaps. To some extent, stigmatizing beliefs are based on
partial truths about these disorders, namely their dangerousness, their sometimes
poor response to treatment, the sufferers' part in their maintenance, and
difficulties in communication. This review explores the truth of these beliefs
and suggests ways in which a more positive approach to the management of eating
disorders might help to reduce the stigma. This includes empathy with the
patient's predicament and an approach to treatment in which the patient's wishes
are paramount.
PMID- 10695107
TI - Unusual presentation of dissecting aortic aneurysm.
AB - Dissecting aneurysms generally cause radiating back pain, chest pain, or symptoms
caused by aortic insufficiency. Presentation solely with abdominal pain is rare.
We report on a patient with dissecting thoracic aortic aneurysm who presented
solely with abdominal pain. The possibility of intrathoracic disease must be
considered in every patient with abdominal pain, especially if the pain is in the
upper part of the abdomen.
PMID- 10695108
TI - Mucocoeles of the maxillary sinus.
AB - Mucocoeles of the paranasal sinuses most commonly occur in the frontal or
anterior ethmoidal sinuses. We report two rare cases of mucocoele of the
maxillary sinus and describe the presentation, investigations and treatment. A
review of the literature on this rare clinical entity is included, with specific
reference to diagnostic imaging to distinguish mucocoeles from neoplastic sinus
disease.
PMID- 10695109
TI - Asymptomatic pituitary apoplexy after aortocoronary bypass surgery.
AB - Pituitary apoplexy usually presents with acute neuro-ophthalmological
complications that require urgent neurosurgical intervention. We present a case
of pituitary apoplexy following aortocoronary bypass surgery that was
asymptomatic until the patient presented with features of hormonal deficiency
three months later. Only one case of pituitary apoplexy has been described in the
literature following cardiac surgery that did not require operative intervention.
We discuss the aetiology of pituitary apoplexy and the possible mechanisms for
such an event after cardiac surgery. Although this is rare, any unusual feature
after operation such as lethargy or erectile dysfunction should remind us of
hypopituitarism.
PMID- 10695110
TI - The use of recombinant human G-CSF in the treatment of propylthiouracil-induced
agranulocytosis.
AB - A 43-year-old female patient with Basedow-Graves' disease developed
agranulocytosis in the eighth month of propylthiouracil therapy. After
discontinuing the drug, a broad spectrum antibiotic regimen plus recombinant
human granulocyte colony-stimulating factor (G-CSF), a human haematopoietic
growth factor, were started. Her granulocyte count returned to normal with the
second dose of G-CSF, and ulcerating pharyngitis improved rapidly. We think that
in patients with propylthiouracil-induced agranulocytosis, G-CSF will reduce the
risk and severity of infection, and should be accepted as a part of the standard
therapy.
PMID- 10695111
TI - An unusual cause of falls in an elderly patient.
AB - Falls are common in the elderly, often causing considerable morbidity and
mortality. Prevention is therefore important and is based on determining the
cause. We present an elderly patient who had multiple falls during the day due to
recurrent daytime sleep episodes, an entity we believe has not previously been
reported.
PMID- 10695112
TI - Delayed diagnosis of an enteric duplication cyst.
AB - Enteric duplication cysts are rare and often prove extremely difficult to
diagnose. We report a case in which the definitive diagnosis was made 40 years
after first presentation and following five exploratory laparotomies. A review of
the literature is presented, with discussion regarding the presenting features,
potential complications, radiological investigations and surgical treatment of
this uncommon clinical entity.
PMID- 10695113
TI - On the chronotherapy of asthma.
PMID- 10695114
TI - Quality of life in Parkinson's disease.
PMID- 10695115
TI - The Institute of Naval Medicine.
PMID- 10695116
TI - Nursing: an all graduate profession?
PMID- 10695117
TI - Nagorno Karabakh.
PMID- 10695118
TI - Peutz-Jeghers syndrome--a case report.
AB - A case of Peutz-Jeghers Syndrome presenting acutely with ileo-ileal
intussusception is described. Management issues including follow up protocols are
reviewed with reference to the current literature.
PMID- 10695119
TI - Operational telemedicine.
AB - A simple, effective digital camera and E-mail-based telemedicine system has been
developed using commercially available equipment. Initial trials were successful
and this system is now deployed in several operational units. A retrospective
audit has shown it to be of value in 50% of referrals.
PMID- 10695120
TI - EMIS: the story so far.
PMID- 10695121
TI - QARNNS at sea--HMS Roebuck.
AB - Despite an initial problem of seasickness I thoroughly enjoyed my five weeks at
sea on board HMS Roebuck. Having to make medical decisions can be somewhat
daunting. However, you always have back up radio support if required. Although
only at sea for a short time, my experience has given me a good insight into life
at sea especially with both men and women serving on the same ship. With no
experience of serving on board larger ships I can recommend that, if possible
further QARNNS ratings are given the opportunity to sample life on board HMS
Roebuck and that their presence on board would be appreciated by the ship's
company, especially with their forthcoming East Coast Surveys. All that remains
to say is to thank the Captain and the rest of the ship's company for making me
feel so welcome and that the terms 'For Exercise, for exercise, for exercise and
Machinery Breakdown' will be sorely missed.....not! ('fair one!' as the Buffer
would say).
PMID- 10695122
TI - Body composition and fitness of Royal Naval officer cadets.
PMID- 10695123
TI - Monckton House at the Institute of Naval Medicine, Alverstoke.
PMID- 10695124
TI - Subcellular imaging by dynamic SIMS ion microscopy.
PMID- 10695125
TI - Electrically facilitated molecular transport. Analysis of the relative
contributions of diffusion, migration, and electroosmosis to solute transport in
an ion-exchange membrane.
AB - Electrically facilitated molecular transport in an ion-exchange membrane (Nafion,
1100 equiv wt) has been studied using a scanning electrochemical microscope. The
transport rates of ferrocenylmethyltrimethylammonium (a cation), acetaminophen (a
neutral molecule), and ascorbate (an anion) through approximately 120-micron
thick membranes were measured as a function of the iontophoretic current passed
across the membrane (-1.0 to +1.0 A/cm2). Transport rates were analyzed by
employing the Nernst-Planck equation, modified to account for electric field
driven convective transport. Excellent agreement between experimental and
theoretical values of the molecular flux was obtained using a single fitting
parameter for each molecule (electroosmotic drag coefficient). The electroosmotic
velocity of the neutral molecule, acetaminophen, was shown to be a factor of
approximately 500 larger than that of the cation
ferrocenylmethyltrimethylammonium, a consequence of the electrostatic interaction
of the cation with the negatively charged pore walls of the ion-exchange
membrane. Electroosmotic transport of ascorbate occurred at a negligible rate due
to repulsion of the anion by the cation-selective membrane. These results suggest
that electroosmotic velocities of solute molecules are determined by specific
chemical interactions of the permeant and membrane and may be very different from
the average solution velocity. The efficiency of electroosmotic transport was
also shown to be a function of the membrane thickness, in addition to
membrane/solute interactions.
PMID- 10695126
TI - Single-molecule identification by spectrally and time-resolved fluorescence
detection
AB - A method to identify single molecules rapidly and with high efficiency based on
simple probability considerations is proposed. In principle, any property of a
detected photon in a single-molecule fluorescence experiment, e.g., emission
wavelength, arrival time after pulsed excitation, and polarization, can be
analyzed within the framework of the outlined methodology. Monte Carlo
simulations show that less than 500 photons are needed to assign an observed
single molecule to one out of four species with a confidence level higher than
99.9%. We show that single dye molecules of four different dyes embedded in a
polymer film can be identified with time-correlated single-photon counting
spectrally resolved in two channels.
PMID- 10695127
TI - Ion isolation in a continuous zero angle reflecting time-of-flight mass
spectrometer
AB - A continuous zero angle reflecting time-of-flight mass spectrometer capable of
tandem mass spectrometry measurements with high resolution and high sensitivity
has been developed. The instrument design features two pulsed-ion mirrors in a
coaxial geometry. Ions can be reflected back and forth with the mirrors, which
increases the net flight length and permits kinetic energy focusing for enhanced
resolution. The instrument also contains an electrostatic particle guide which
increases ion transmission efficiency and can be used in a bipolar pulsed mode to
isolate ions of interest for structural study.
PMID- 10695128
TI - Evaluation of uncompensated solution resistance for electrodes with spherical-cap
geometry
AB - Typical custom and commercial hanging mercury drop electrodes have the geometry
of a spherical cap formed by the plane of the lower surface of the electrode
holder cutting off the top of the drop. To conduct accurate quantitative
measurements by voltammetry, it is necessary to be able to account for the
effects of solution resistance, Ru. A method of determining the solution
resistance is proposed and tested. The method involves making measurements of a
test reaction (in this case, oxidation of ferrocene) by cyclic voltammetry at
scan rates where resistance effects are important and at more than one
concentration. When the data are analyzed by digital simulation, it is found that
only one value of Ru will provide adequate matches between simulation and
experiment at all concentrations. An approximate equation has been derived that
allows calculation of Ru from the dimensions of the spherical-cap electrode and
the solution resistivity. The calculated values of Ru for electrodes of three
different sizes agreed well with the measured values. Error analysis was
performed for a particular measurement, the determination of the standard
heterogeneous electron-transfer rate constant, ks, by cyclic voltammetry, and it
was shown that uncertainty in Ru puts an upper limit of about 1 cm/s for the
determination of ks with the hanging mercury drop electrodes used in this study.
PMID- 10695129
TI - Absorption of hydrophobic compounds into the poly(dimethylsiloxane) coating of
solid-phase microextraction fibers: high partition coefficients and fluorescence
microscopy images.
AB - The use of solid-phase microextraction with poly(dimethylsiloxane) (PDMS)-coated
glass fibers for the extraction and analysis of hydrophobic organic analytes is
increasing. The literature on this topic is characterized by large discrepancies
in partition coefficients and an uncertainty of whether highly hydrophobic
analytes are retained by absorption into the fiber coating or by adsorption to
the fiber surface. We applied a new method, which minimizes the impact of
experimental artifacts, to determine PDMS water partition coefficients of 17
hydrophobic analytes including chlorinated benzenes, PCBs, PAHs, and p,p'-DDE.
These partition coefficients are several orders of magnitude higher than some
reported values. Two observations strongly suggest that the retention of
hydrophobic organic substances is governed by partitioning into the PDMS coating.
(1) The partition coefficients are proportional with octanol/water partition
coefficients. (2) The fluorescence of fluoranthene was observed to be
homogeneously distributed within the polymer coating when studied by means of
fluorescence microscopy. Implications of these findings for the application of
solid-phase microextraction with respect to potential detection limits, with
respect to biomimetic extraction, and with respect to measurements in
multicompartment systems are discussed.
PMID- 10695130
TI - Visual and colorimetric lithium ion sensing based on digital color analysis.
AB - A new optical analytical method, "Digital Color Analysis (DCA)", is proposed
based on a digital color analyzer instead of the conventional optical
methodology, "Spectrophotometry". The digital color analyzer is a hand-held-size
instrument for measuring "colors", and it can transform the color information
into numerical values, color library data, etc., that can be treated as
analytical information. DCA gives us a more informative analytical method than
spectrophotometry by treating colors as digital information. In addition, DCA can
also simulate the optimum color variations for optimization of the visual sensor
with computer assistance. By utilizing colors as digital information,
colorimetric analysis that has been used for only semiquantitative analysis can
serve as an accurate determination method. On the basis of DCA, we developed a
plasticized PVC film optode and a paper optode for Li+ determination in saliva.
After the optimization of color variation and the detection range for the Li+
measurements, the optode membrane gives colorless gray in the Li+ therapeutic
range (at 10(-3) M) in saliva. Consequently, whether or not the optimum
therapeutic Li+ concentration is maintained can be easily evaluated with these
optodes. Especially, the sensing paper optode can be easily handled within a
short measurement time (approximately 80 s) which is suitable for home use. Using
the digital color analyzer with QxQy coordinates, a linear relation calibration
curve can be obtained over the range from 10(-5) to 10(-1) M Li+, in which the
analyzer can detect a concentration difference of approximately 0.1 mM Li+. For
the near future, an accurate and simple analysis is needed for a health check at
home that does not require going to a hospital. The optode based on DCA has great
potential for this analytical purpose.
PMID- 10695131
TI - Characterization of pH in liquid mixtures of methanol/H2O/CO2.
AB - The presence of H2O and CO2 in enhanced-fluidity liquids changes the pH in these
mixtures due to the formation of carbonic acid. The acid-base equilibria in
enhanced-fluidity liquids will also be affected by the reduction in the
dielectric constant with the addition of CO2. The pH of enhanced-fluidity liquid
mixtures at room temperature was determined from the UV/visible absorption
spectra of several pH indicators. pH values of methanol/H2O/CO2 mixtures with CO2
proportions as high as 19.2 mol% are reported. The effect of adding buffer to
methanol/H2O/CO2 mixtures on pH was also studied. It was also shown that pressure
variation did not significantly influence the pH of enhanced-fluidity liquids.
PMID- 10695132
TI - Static subcritical water extraction combined with anion exchange disk sorption
for determining chlorinated acid herbicides in soil.
AB - Static subcritical water extraction (SbWE) was coupled with collection on a
strong anion exchange (SAX) disk for the determination of chlorinated acid
herbicides and their esters in soil. With 100-150 degrees C water, esters were
hydrolyzed into their acid form, and the herbicide acids extracted by subcritical
water were trapped onto/into a SAX disk as the extraction cell was cooled. The
trapped solutes were then derivatized for gas chromatographic (GC) analysis by
placing the disk into a GC autosampler vial containing 1 mL of N,O
bis(trimethylsilyl)trifluoroacetamide derivatizing reagent. With the static
SbWE/SAX disk extraction, nearly quantitative recoveries (typically over 80%)
were obtained at 100 degrees C for 30 min in the extraction of herbicide acids
and esters spiked on several different soils covering a range of organic content
from 0.3 to 12%. Good agreements were reached between this method and EPA method
8151 for aged spiked soils. Detection limits of the static SbWE/SAX disk
extraction were from 0.05 to 0.5 ppm and from 0.01 to 0.5 ppm using GC/electron
capture detector and GC/mass spectrometry, respectively. The method is fast and
simple and uses a small amount of organic solvent.
PMID- 10695133
TI - Real-time amperometric measurements of zeptomole quantities of dopamine released
from neurons.
AB - Amperometry with carbon-fiber microelectrodes provides a unique way to measure
very small chemical concentration changes at the surface of biological cells. In
this work, an investigation of dopamine release from individual neurons isolated
from the mouse retina is described. The mice were genetically modified so that,
in cells that expressed the protein responsible for catecholamine synthesis,
tyrosine hydroxylase, the marker protein, placental alkaline phosphatase, was
also expressed. This modification allowed for identification of the dopamine
containing cells among the many present in the freshly dissociated retina.
Release of dopamine was evoked by chemical secretagogues delivered from
micropipets that were calibrated with respect to response time and concentration
delivered. Amperometric measurements were recorded with low-noise patch clamp
amplifiers, and the primary noise source was found to be the electrode
capacitance. Dopamine release occurred in the form of transient concentration
spikes, consistent with release from small intracellular vesicles. With optimized
filtering of the data, the quantity secreted during each release event could be
determined. The average quantity determined at one cell was 52 zmol. However, the
spikes were quite variable in size and the amount released per event ranged from
8 to 170 zmol. These measurements allow an estimation of the concentration of
released transmitter in a synapse.
PMID- 10695134
TI - Electrochemistry in nanovials fabricated by combining screen printing and laser
micromachining
AB - The coupling of screen-printing and laser micromachining technology has been used
to create a nanovial with "built-in" working and reference electrodes. The volume
of the nanovial was calculated to be 7.2 nL using dimensions determined by SEM.
The electrochemical nanovial was characterized using the ferri/ferrocyanide redox
couple. Cyclic voltammetry and chronoamperometry experiments were performed with
electrochemical nanovials utilizing 5% (v/v) glycerin in the solutions and a
humidified headspace to control evaporation of the small-volume samples.
Chronoamperometry experiments gave results consistent with a diffusion-limited
process and revealed a working electrode surface area of 2.6 x 10(4) micron 2.
The ultrasmall-volume cells represent a simple, reliable, low-cost approach for
the fabrication of complete electrochemical nanovials.
PMID- 10695135
TI - Covalent attachment of osmium complexes to glucose oxidase and the application of
the resulting modified enzyme in an enzyme switch responsive to glucose.
AB - Pyridine-based osmium complexes bearing either a carboxylate or aldehyde group
were covalently attached to glucose oxidase and were shown to work as mediators
for the reoxidation of the enzyme. For the complex containing the carboxylate
group, the binding was made through carbodiimide coupling to the amine residues
in the protein. For the complex containing the aldehyde group, the reductive
coupling was carried out by condensation with the amino groups on the protein in
the presence of sodium cyanoborohydride. Electrochemical studies show evidence
for both intramolecular and intermolecular redox mediation for the
electrochemical reoxidation of the modified glucose oxidases in the presence of
glucose. The modified enzymes adsorbed on glassy carbon and platinum show
different electrochemical responses for the two electrode materials, suggesting
that orientation of the adsorbed enzyme is induced due to the interaction of the
osmium complex with the different surfaces. Construction of enzyme switches based
on these modified enzymes was carried out, and their responses were compared with
those obtained using native glucose oxidase and a soluble redox mediator.
PMID- 10695136
TI - Dual-pipet techniques for probing ionic reactions
AB - Novel dual-pipet electrodes prepared by pulling borosilicate theta-tubing are
described. Three types of electrochemical experiments employing such devices
include the following: (1) generation/collection experiments in which ions are
ejected from one of two micropipets ("generator") into the external solution and
collected at the second pipet ("collector"), (2) measurements of ohmic current
voltage curves, and (3) ion-transfer voltammetry "in the air". The first setup is
used for probing ion transfers at the interface between two immiscible liquids
and homogeneous reactions in solution involving ionic species. Such experiments
are reported for two model processes, i.e., simple and facilitated transfers of
potassium between aqueous and organic phases and complexation of potassium with
dibenzo-18-crown-6 in organic solution. The second arrangement is used for
characterization of theta-pipets. The last arrangement can be useful for
preparation of gas sensors. The possibility of measuring the concentration of
volatile substances (e.g., ammonia and nitric acid) in the gaseous phase has been
demonstrated.
PMID- 10695137
TI - Electrocatalytic detection of NADH and glycerol by NAD(+)-modified carbon
electrodes.
AB - The electrochemical oxidation of the adenine moiety in NAD+ and other adenine
nucleotides at carbon paste electrodes gives rise to redox-active products which
strongly adsorb on the electrode surface. Carbon paste electrodes modified with
the oxidation products of NAD+ show excellent electrocatalytic activity toward
NADH oxidation, reducing its overpotential by about 400 mV. The rate constant for
the catalytic oxidation of NADH, determined by rotating disk electrode
measurements and extrapolation to zero concentration of NADH, was found to be 2.5
x 10(5) M-1 s-1. The catalytic oxidation current allows the amperometric
detection of NADH at an applied potential of +50 mV (Ag/AgCl) with a detection
limit of 4.0 x 10(-7) M and linear response up to 1.0 x 10(-5) M NADH. These
modified electrodes can be used as amperometric transducers in the design of
biosensors based on coupled dehydrogenase enzymes and, in fact, we have designed
an amperometric biosensor for glycerol based on the glycerol dehydrogenase (GlDH)
system. The enzyme GlDH and its cofactor NAD+ were co-immobilized in a carbon
paste electrode using an electropolymerized layer of nonconducting poly(o
phenylenediamine) (PPD). After partial oxidation of the immobilized NAD+, the
modified electrode allows the amperometric detection of the NADH enzymatically
obtained at applied potential above 0 V (Ag/AgCl). The resulting biosensor shows
a fast and linear response to glycerol within the concentration range of 1.0 x
10(-6)-1.0 x 10(-4) M with a detection limit of 4.3 x 10(-7) M. The amperometric
response remains stable for at least 3 days. The biosensor was applied to the
determination of glycerol in a plant-extract syrup, with results in good
agreement with those for the standard spectrophotometric method.
PMID- 10695138
TI - Atmospheric NO2: in situ laser-induced fluorescence detection at parts per
trillion mixing ratios
AB - We describe a time-gated laser-induced fluorescence instrument designed for
accurate (+/- 5%, 1 sigma), continuous, autonomous, in situ observations of NO2
with the sensitivity (15 ppt/10 s at S/N = 2) and portability necessary to study
NO2 anywhere in the troposphere. The technique is advantageous because it is
spectroscopically specific and direct in that it does not require conversion of
NO2 into another species (e.g., NO) prior to detection, eliminating a class of
potential interferences. Performance of the instrument is illustrated with 15
weeks (July-Oct 1998) of observations at the University of California, Blodgett
Forest field station located in the foothills of the Sierra Nevada and 4 weeks
(June 15-July 15, 1999) in Nashville, TN during the Southern Oxidants Study.
Ambient concentrations of NO2 at Blodgett Forest varied from below 50 ppt to 4000
ppt and NO2 ranged from 5 to 50% of the total reactive nitrogen; while in
Nashville, TN, concentrations ranged from 1 to 75 ppb.
PMID- 10695139
TI - High-resolution mass spectrometry with a quadrupole operated in the fourth
stability region
AB - The properties of a quadrupole mass filter operated in the fourth stability
region with Mathieu parameters (a,q) = (2 x 10(-3), 21.3) have been investigated
experimentally and theoretically. A resolution at half-height (R1/2) of 13,900
has been obtained for 40 eV 39K+ ions formed by thermal ionization. With ion
energies of 750 eV or more, a resolution at half-height of up to 5000 can be
obtained. Extrapolation of resolution data obtained with ions of 40 eV-4800 eV
energy shows that unit resolution should be possible for ions with energies of
approximately 10 keV. For low-energy ions (e.g., 75 eV), the transmission of the
quadrupole operated in the fourth region is many orders of magnitude less than
that of a quadrupole operated in the first or second stability regions.
Acceptance calculations show this is a result of the combination of a much lower
acceptance and strongly defocusing fringing fields. However, for higher ion
energies, the transmission with operation in the fourth region is found to be
comparable to that of a quadrupole operated at the same resolution in the second
region. The implications for inductively coupled plasma mass spectrometry are
briefly discussed.
PMID- 10695140
TI - Determination of chlorophenols in soils using accelerated solvent extraction
combined with solid-phase microextraction.
AB - A method for the determination of chlorophenols in soil samples using accelerated
solvent extraction (ASE) with water as the solvent combined with solid-phase
microextraction (SPME) and GC/MS has been developed. Important ASE parameters,
such as extraction temperature and time, were optimized using a spiked wetland
soil. The effect of small amounts of organic modifiers on the extraction yields
was studied. An extraction temperature of 125 degrees C and 10 min extractions
performed three times proved optimal. Two ASE-SPME procedures without and with an
organic modifier (5% acetonitrile) were evaluated with respect to precision and
detection limits (LOD). The reproducibility of replicate water extractions/SPME
determinations (n = 6) was in the range 7-20% relative standard deviation for the
nine chlorophenols investigated. LOD values in the low-ppb range were achieved
for all chlorophenols. The ASE-SPME procedure presented here was applied to the
determination of chlorophenols in soil samples taken from contaminated areas near
Bitterfeld, Germany.
PMID- 10695141
TI - The characteristics of peptide collision-induced dissociation using a high
performance MALDI-TOF/TOF tandem mass spectrometer.
AB - A new matrix-assisted laser desorption/ionization (MALDI) time-of-flight/time-of
flight (TOF/TOF) high-resolution tandem mass spectrometer is described for
sequencing peptides. This instrument combines the advantages of high sensitivity
for peptide analysis associated with MALDI and comprehensive fragmentation
information provided by high-energy collision-induced dissociation (CID). Unlike
the postsource decay technique that is widely used with MALDI-TOF instruments and
typically combines as many as 10 separate spectra of different mass regions, this
instrument allows complete fragment ion spectra to be obtained in a single
acquisition at a fixed reflectron voltage. To achieve optimum resolution and
focusing over the whole mass range, it may be desirable to acquire and combine
three separate sections. Different combinations of MALDI matrix and collision gas
determine the amount of internal energy deposited by the MALDI process and the
CID process, which provide control over the extent and nature of the fragment
ions observed. Examples of peptide sequencing are presented that identify
sequence-dependent features and demonstrate the value of modifying the ionization
and collision conditions to optimize the spectral information.
PMID- 10695142
TI - Field-emission cold-cathode el source for a microscale ion trap mass spectrometer
AB - A cold-cathode electron impact ionization source based on field emission from an
array of diamond-coated silicon whiskers is described. The source is coupled to a
microscale ion trap mass spectrometer (r0 = 0.50 mm, z0 = 0.50 mm). An electron
beam of 250 nA could be obtained through the 0.45-mm diameter opening in the end
cap electrode.
PMID- 10695143
TI - Electron capture dissociation for structural characterization of multiply charged
protein cations.
AB - For proteins of < 20 kDa, this new radical site dissociation method cleaves
different and many more backbone bonds than the conventional MS/MS methods (e.g.,
collisionally activated dissociation, CAD) that add energy directly to the even
electron ions. A minimum kinetic energy difference between the electron and ion
maximizes capture; a 1 eV difference reduces capture by 10(3). Thus, in an FTMS
ion cell with added electron trapping electrodes, capture appears to be achieved
best at the boundary between the potential wells that trap the electrons and
ions, now providing 80 +/- 15% precursor ion conversion efficiency. Capture cross
section is dependent on the ionic charge squared (z2), minimizing the secondary
dissociation of lower charge fragment ions. Electron capture is postulated to
occur initially at a protonated site to release an energetic (approximately 6 eV)
H. atom that is captured at a high-affinity site such as -S-S- or backbone amide
to cause nonergodic (before energy randomization) dissociation. Cleavages between
every pair of amino acids in mellitin (2.8 kDa) and ubiquitin (8.6 kDa) are
represented in their ECD and CAD spectra, providing complete data for their de
novo sequencing. Because posttranslational modifications such as carboxylation,
glycosylation, and sulfation are less easily lost in ECD than in CAD, ECD
assignments of their sequence positions are far more specific.
PMID- 10695144
TI - Mass spectrometric analysis of mercury incorporation into proteins for X-ray
diffraction phase determination.
AB - Heavy-atom incorporation is an essential and often rate-limiting step in the
determination of phases for X-ray diffraction studies of protein structures.
Until the present, there has been no practical method (short of the X-ray
diffraction experiment itself) to judge the success and extent of incorporation.
Here we show that mass spectrometry is an effective tool for determining the
extent of heavy-atom incorporation in proteins. In particular, we demonstrate the
utility of matrix-assisted laser desorption/ionization mass spectrometry (MALDI
MS) and electrospray ionization mass spectrometry (ESI-MS) for assaying mercury
derivatization of cysteinyl thiol groups in proteins. Each of these mass
spectrometric methods has advantages and drawbacks. ESI-MS provides a more
accurate quantitative measurement of the extent of mercury incorporation, while
MALDI-MS provides a useful lower limit to the level of mercury incorporation.
Conversely, MALDI-MS does not require removal of excess derivatization reagents,
salts and buffers, thus permitting facile analysis of single protein crystals as
well as rapid, semiquantitative evaluation of the extent of protein mercuration.
The approaches described in the present paper have contributed to the successful
X-ray analyses of several noteworthy protein structures.
PMID- 10695145
TI - Using different drift gases to change separation factors (alpha) in ion mobility
spectrometry
AB - The use of different drift gases to alter separation factors (alpha) in ion
mobility spectrometry has been demonstrated. The mobility of a series of low
molecular weight compounds and three small peptides was determined in four
different drift gases. The drift gases chosen were helium, argon, nitrogen, and
carbon dioxide. These drift gases provide a range of polarizabilities and
molecular weights. In all instances, the compounds showed the greatest mobility
in helium and the lowest mobility in carbon dioxide; however the percentage
change of mobility for each compound was different, effectively changing the
alpha value. The alpha value changes were primarily due to differences in drift
gas polarizability but were also influenced by the mass of the drift gas. In
addition, gas-phase ion radii were calculated in each of the different drift
gases. These radii were then plotted against drift gas polarizability producing
linear plots with r2 values greater than 0.99. The intercept of these plots
provides the gas-phase radius of an ion in a nonpolarizing environment, whereas
the slope is indicative of the magnitude of the ion's mobility change related to
polarizability. It therefore, should be possible to separate any two compounds
that have different slopes with the appropriate drift gas.
PMID- 10695146
TI - Trapping of bead-based reagents within microfluidic systems: on-chip solid-phase
extraction and electrochromatography
AB - A 330-pL chromatographic bed was fabricated on a glass substrate as part of an
electroosmotically pumped microfluidic system. Two weirs within a sample channel
formed a cavity in which octadecylsilane (ODS) coated silica beads (1.5-4 microns
diameter) were trapped. ODS beads were mobilized into and out of the cavity using
electroosmotic flow through a bead-introduction channel which accessed the
cavity. This procedure allowed the beads in the cavity to be repeatedly
exchanged. A 1 nM solution of a nonpolar analyte (BODIPY 493/503) in buffer was
loaded onto the beads for different lengths of time using an electroosmotic flow
of 1.2 nL/s. The material retained on the ODS phase was then eluted by
electroosmotic flow of acetonitrile with a concentration enhancement of up to 500
times. Capillary electrochromatography was conducted using a similar device.
BODIPY and fluorescein were loaded onto a 200-micron-long chromatographic bed and
then separated in an isocratic CEC run with an acetonitrile/buffer mobile phase.
Complete separation was achieved in less than 20 s with a 2-micron plate height.
PMID- 10695147
TI - Peak capacity, peak-capacity production rate, and boiling point resolution for
temperature-programmed GC with very high programming rates
AB - Recent advances in column heating technology have made possible very fast linear
temperature programming for high-speed gas chromatography. A fused-silica
capillary column is contained in a tubular metal jacket, which is resistively
heated by a precision power supply. With very rapid column heating, the rate of
peak-capacity production is significantly enhanced, but the total peak capacity
and the boiling-point resolution (minimum boiling-point difference required for
the separation of two nonpolar compounds on a nonpolar column) are reduced
relative to more conventional heating rates used with convection-oven
instruments. As temperature-programming rates increase, elution temperatures also
increase with the result that retention may become insignificant prior to
elution. This results in inefficient utilization of the down-stream end of the
column and causes a loss in the rate of peak-capacity production. The rate of
peak-capacity production is increased by the use of shorter columns and higher
carrier gas velocities. With high programming rates (100-600 degrees C/min),
column lengths of 6-12 m and average linear carrier gas velocities in the 100-150
cm/s range are satisfactory. In this study, the rate of peak-capacity production,
the total peak capacity, and the boiling point resolution are determined for C10
C28 n-alkanes using 6-18 m long columns, 50-200 cm/s average carrier gas
velocities, and 60-600 degrees C/min programming rates. It was found that with a
6-meter-long, 0.25-mm i.d. column programmed at a rate of 600 degrees C/min, a
maximum peak-capacity production rate of 6.1 peaks/s was obtained. A total peak
capacity of about 75 peaks was produced in a 37-s long separation spanning a
boiling-point range from n-C10 (174 degrees C) to n-C28 (432 degrees C).
PMID- 10695148
TI - Separation and identification of peptides from gel-isolated membrane proteins
using a microfabricated device for combined capillary
electrophoresis/nanoelectrospray mass spectrometry.
AB - The coupling of microfabricated devices to nanoelectrospray mass spectrometers
using both a triple quadrupole and a quadrupole time-of-flight mass spectrometer
(QqTOF MS) is presented for the analysis of trace-level membrane proteins. Short
disposable nanoelectrospray emitters were directly coupled to the chip device via
a low dead volume connection. The analytical performance of this integrated
device in terms of sensitivity and reproducibility was evaluated for standard
peptide mixtures. A concentration detection limit ranging from 3.2 to 43.5 nM for
different peptides was achieved in selected ion monitoring, thus representing a
10-fold improvement in sensitivity compared to that of microelectrospray using
the same chip/mass spectrometer. Replicate injections indicated that
reproducibility of migration time was typically less than 3.1% RSD whereas RSD
values of 6-13% were observed on peak areas. Although complete resolution of
individual components is not typically achieved for complex digests, the present
chip capillary electrophoresis (chip-CE) device enabled proper sample cleanup and
partial separation of multicomponent samples prior to mass spectral
identification. Analyses of protein digests were typically achieved in less than
1.5 min with peak widths of 1.8-2.5 s (half-height definition) as indicated from
individual reconstructed ion electropherograms. The application of this chip
CE/QqTOF MS system is further demonstrated for the identification of membrane
proteins which form a subset of the Haemophilus influenzae proteome. Bands first
separated by 1D-gel electrophoresis were excised and digested, and extracted
tryptic peptides were loaded on the chip without any further sample cleanup or on
line adsorption preconcentration. Accurate molecular mass determination (< 5 ppm)
in peptide-mapping experiments was obtained by introducing an internal standard
via a postseparation channel. The analytical potential of this integrated device
for the identification of trace-level proteins from different strains of H.
influenzae is demonstrated using both peptide mass-fingerprint database searching
and on-line tandem mass spectrometry.
PMID- 10695149
TI - Silicate polymerization for the preparation of bed-retention frits in capillary
electrochromatography
AB - Bubble formation, which is associated with bed-retention frits, is a critical
experimental problem in capillary electrochromatography systems. In this
investigation, porous silica frits were prepared via spot-heating of a silicate
solution, and the effects of several experimental parameters on their performance
were studied. The optimal sodium silicate concentrations were 10.8% and 5.4%
(w/v) for outlet and inlet frits, respectively. The heating times were 5-6 s for
outlet frits and < 1 s for inlet frits. Under optimized conditions, outlet frits
were 75 microns (+/- 12 microns) and the heat treatment did not make the
capillary fragile at the frit location. Bubble formation was affected by frit
length, density, and silanization of the frits with trimethylchlorosilane. Packed
capillaries with optimized frits were used successfully in a commercial CE
instrument over a normal working day without pressurization, at relatively high
ionic strengths (10 mM), and over a wide range of acetonitrile compositions (20%
80%). Currents were also stable for > or = 3 h under very high current (27
microA) conditions. As part of this study, the efficiency and reproducibility of
packed capillaries were also briefly evaluated.
PMID- 10695150
TI - Capillary electrochromatography using a strong cation-exchange column with a
dynamically modified cationic surfactant
AB - A novel mode of capillary electrochromatography (CEC), called dynamically
modified strong cation-exchange CEC (DMSCX-CEC), is described in this paper. A
column packed with a strong cation-exchange (SCX) packing material was
dynamically modified with a long-chain quaternary ammonium salt,
cetyltrimethylammonium bromide (CTAB), which was added to the mobile phase. CTAB
ions were adsorbed onto the surface of the SCX packing material, and the
resulting hydrophobic layer on this packing was used as the stationary phase.
Using the dynamically modified SCX column, neutral solutes were separated with
the CEC mode. The highest number of theoretical plates obtained was about
190,000/m, and the relative standard deviations (RSD's) for migration times and
capacity factors of alkylbenzenes were less than 1.0% and 2.0% for five
consecutive runs, respectively. The effects of CTAB and methanol concentrations
and the pH value of the mobile phase on the electroosmotic flow and the
separation mechanism were investigated. Excellent simultaneous separation of the
basic and neutral solutes in DMSCX-CEC with a high-pH mobile phase was obtained.
A mixture containing the acidic, basic, and neutral compounds was well separated
in this mode with a low-pH mobile phase; however, peak tailing for basic
compounds was observed in this mobile phase.
PMID- 10695151
TI - Measurement of aqueous Henry's law constants for oxygenates and aromatics found
in gasolines by the static headspace method
AB - A simple equilibrium vessel made from a large stopcock was used in conjunction
with the static headspace method to measure the aqueous Henry's law constants for
methyl tert-butyl ether (MTBE) and other potential oxygenates as well as certain
of the aromatics found in gasoline. The present method involves using only one
aqueous solution whose concentration is not necessarily known. The only quantity
that must be known is the phase ratio. Plotting a series of peak areas of the
analyte in the headspace after each equilibrium change against the initial peak
area of the analyte found in the headspace leads to a linear relationship whose
slope is dependent on the analyte's unitless Henry's law constant and the phase
ratio. This new method is found to yield unitless aqueous Henry's law constants
in the range from 0.02 to 0.2, which are especially applicable to the oxygenates
and aromatics found in gasolines.
PMID- 10695152
TI - Sheathless capillary electrophoresis/electrospray mass spectrometry using a
carbon-coated fused-silica capillary
AB - A simple procedure was developed for preparing a carbon-coated fused-silica
capillary for use in sheathless capillary electrophoresis/electrospray mass
spectrometry (CE/ESI-MS). The tapered capillary tip was smeared with a marker pen
before coating with carbon using a soft pencil. The layer from the ink of the
marker pen was critical to the preparation of the carbon-coated capillary. The
fabrication of a carbon-coated fused-silica capillary tip requires less than 1
min. The stability of this carbon-coated fused-silica capillary is examined, and
its utility in on-line sheathless CE/ESI-MS is demonstrated with the separation
of berberine, coptisine, and palmatine chlorides. Although the carbon-coated
fused-silica capillary tip is not as rugged as a gold-coated capillary, it is
durable enough for sheathless CE/ESI-MS applications. Moreover, it is easy to
refurbish the column once the performance of the tip is degraded.
PMID- 10695153
TI - In-line catalytic purification of carbon dioxide used in analytical-scale
supercritical fluid extraction
AB - Supercritical fluid extraction analyses are often compromised by trace impurities
present in the solvent carbon dioxide. These impurities, commonly used as
lubricants in the specialty gas industry, can produce significant background
levels, increasing limits of detection and quantification. This problem is
especially severe when electron capture detection (ECD) is used for trace
concentrations of analytes (e.g., polychlorinated biphenyls and chlorinated
pesticides). In this study, an in-line catalyst-based purification system was
successfully employed to remove ECD-responsive contaminants from CO2. Low-purity
(98%) "Bone Dry" CO2 was purified to levels cleaner than a very-high-purity grade
of CO2 specified at less than 10 ppt ECD-responsive contaminants. Purification
was successfully applied to extremely sensitive on-column experiments as well as
higher flow rate off-line experiments. In addition to lowering limits of
detection and quantification, significant cost savings can be realized by
purifying inexpensive, low-purity CO2 instead of relying on much more expensive,
prepurified CO2.
PMID- 10695154
TI - Determination of a sulfur-containing drug in human plasma by an improved method
for sulfur chemiluminescence detection in combination with capillary gas
chromatography.
AB - An improved method for sulfur chemiluminescence detection in combination with
capillary gas chromatography was established. The method was applied to the
analysis of a sulfur-containing antiasthma drug, S-1452, and its nine
metabolities in human plasma. The high selectivity and sensitivity of the method
allowed accurate quantitation of trace levels of these compounds in human plasma
with no interferences from the biological components present. To enable stable
measurements and maintain reproducibility over a long period, the performance
characteristics of a commercially available instrument were investigated. The gas
seal in the injection port was found to easily corrode through interaction of the
sulfur analyte with the metal gas seal. To prevent this, a disk made from an
alloy of platinum and gold (60:40) was mounted on the gas seal. The
reproducibility of the measurement was improved remarkably by using the disk. The
use of compressed air of high purity significantly lowered the signal-to-noise
ratio. The optical filter was kept clean by using a nickel catalyst to trap ozone
in place of copper manganese oxide (CuMn2O4). These improvements raised the
sensitivity and selectivity with the lower quantitation limits of 0.5-1.0 ng/mL
in human plasma.
PMID- 10695155
TI - Comments on "adsorption versus absorption of polychlorinated biphenyls onto solid
phase microextraction coatings"
PMID- 10695156
TI - Women and bipolar disorder: an update.
AB - The major clinical challenges facing women with bipolar illness, and the
practitioners who care for them, are the management of rapid cycling and of the
postpartum period. Among patients with rapid cycling bipolar disorder, the
treatment of depression is particularly problematic. The most commonly prescribed
mood stabilizers are more potent antimanic than antidepressant agents, and the
use of antidepressants may precipitate mania or rapid cycling. The availability
of new anticonvulsant medications that may have both mood-stabilizing and
antidepressant effects is an important development in this regard. In the
postpartum period, women with bipolar illness are at uniquely high risk for
relapse. The possible reasons for this high risk, and options for the management
of pregnancy and the postpartum period in bipolar women, are discussed.
PMID- 10695157
TI - Body dysmorphic disorder: diagnostic controversies and treatment challenges.
AB - Body dysmorphic disorder (BDD) is a distressing, impairing, and relatively common
yet underrecognized disorder. This clinically focused article discusses the
following diagnostic controversies and challenges associated with BDD: the
underdiagnosis and misdiagnosis of BDD, the relationship between BDD and
obsessive-compulsive disorder, the relationship between BDD and depression, the
delusionality controversy, and whether BDD can be diagnosed in children and
adolescents. This article also discusses treatment controversies and challenges
associated with serotonin reuptake inhibitors, antipsychotics, cognitive
behavioral therapy, approaches to treatment-resistant BDD, and getting reluctant
patients to accept psychiatric treatment.
PMID- 10695158
TI - Workplace violence and psychiatric practice.
AB - The authors provide an overview of what is known about workplace violence and
discuss how to deal with issues of workplace violence that arise in clinical
practice. They review myths and facts about workplace violence, including
research on prevention. Legal issues relating to the psychiatrist as employer and
the Americans with Disability Act are presented. General principles of violence
assessment are reviewed and the authors then discuss the psychiatrist as
consultant to the workplace and as clinician treating a victim or perpetrator of
workplace violence. Three cases illustrate the general principles provided.
PMID- 10695159
TI - Avoiding psychotropic drug interactions in the cardiovascular patient.
AB - Recent advances in our understanding of the hepatic cytochrome P450 inhibitory
effects of the newer antidepressants have increased concern about drug
interactions in the practice of psychiatry. The authors summarize the potential
interactions of psychoactive drugs with cardiovascular medications. Practicing
psychiatrists encounter many patients with cardiovascular disease, and an
awareness of these interactions will improve knowledgeable prescribing for
medically ill patients with comorbid mental disorders.
PMID- 10695160
TI - New antipsychotic medications: more than old wine and new bottles.
AB - Four new antipsychotic medications--clozapine, risperidone, olanzapine, and
quetiapine--have been introduced in the United States during the past decade.
These new medications now account for the majority of antipsychotic
prescriptions. The author reviews specific issues related to the use of
traditional antipsychotic medications and then highlights the emerging clinical
research data regarding the new medications, which have all been shown to be
efficacious in the treatment of schizophrenia. Clinical research data indicate
that they are also more useful for a broader array of symptoms associated with
schizophrenia than traditional compounds. Furthermore, movement disorder side
effects are substantially decreased--a property that leads to higher
acceptability. Surprisingly, there has been little relationship between the
pivotal trials designed for FDA approval and current dosing strategies in broader
clinical settings. These dosing issues are described. New uses, including
treatment of mood disorders and conduct disorder, are also discussed. These
medicines offer substantial hope for improved treatment of schizophrenia.
PMID- 10695161
TI - Priming and projective identification.
AB - The sense of coercion that is a central feature of projective identification
might be understood in terms of the recently discovered phenomenon of priming.
Studies of priming show that a subject may record and be influenced by stimuli of
which he or she is not conscious. Becoming aware of such influence is of central
therapeutic significance. Certain priming experiments suggest that Freud's
discipline of "evenly suspended attention" may provide a means of potentiating
this awareness.
PMID- 10695162
TI - Autonomy and relatedness in the development of anorexia nervosa: a clinical case
series using grounded theory.
AB - The authors propose a prototype for the development of anorexia nervosa on the
basis of a series of clinical interviews with 11 women with this disorder.
Grounded Theory analysis of the narrative data-generated themes suggested the
following prototype: Women with the personality characteristics of compliance and
perfectionism who are encouraged by families and culture to substitute others'
needs for their own are at greater risk for anorexia nervosa during periods of
developmental stress. This proposal is considered from the perspective of
psychodynamic, cognitive, and family systems viewpoints as well as attachment
theory and feminist models of the development of women. The authors suggest that
narrative research contributes substantially to clinical understanding by
capturing the intricate details of a phenomenon or the richness of a lived life.
Nevertheless, there is a need for further quantitative research to test the
specificity and generalizability of this prototype.
PMID- 10695163
TI - Magnum miraculum est homo.
PMID- 10695164
TI - Client perspectives on occupational therapy practice: are we truly client
centred?
AB - In Canada, the guidelines for the practice of occupational therapy are named and
framed as client-centred. Two in-depth interviews were conducted with clients of
mental health services about their experiences with a hospital-based occupational
therapy service. These occupational therapy clients described their experiences
as prescriptive, and as less than client-centred. With the publication of
Enabling occupation: A Canadian occupational therapy perspective (Canadian
Association of Occupational Therapists [CAOT], 1997) and an increasingly refined
focus on being client-centred, these interviews highlight the challenges of a
client-centred practice within the current health care environment. These
occupational therapy clients raise issues of importance for occupational therapy.
The participants stated that the prescription of 'activity', a lack of choice,
and a focus upon the illness as opposed to the individual, served to diminish any
collaborative partnership with the client and eliminate the client from any
decision-making process. This distancing from the client, in their opinion,
served to greatly diminish any therapeutic value of occupation. The participants
recommended a greater focus upon occupational choice, consideration of the
individual within the client, providing accepting, supportive environments, and
using professional expertise on occupation to guide the client towards
participation in meaningful occupation. These recommendations are strikingly
similar to the most recent guidelines for the client-centred practice of
occupational therapy in Canada. A discussion of the implications of these
findings for the client-centred practice of occupational therapy is offered.
PMID- 10695165
TI - Barriers to client-centredness and their resolution.
AB - This research sought to determine which therapist barriers prevent client-centred
practice the most, and which methods are perceived as being most effective in
resolving therapist barriers. A list of barriers that therapists bring to client
centred practice and methods to resolve these was identified from the literature
and formed the basis of a questionnaire sent to 60 occupational therapists in the
United Kingdom. The results showed that the therapist and client having different
goals was the barrier which most prevented client-centred practice. The high
ratings of other statements suggested that the values, beliefs and attitudes of
therapists and of the employment culture make client-centred practice
uncomfortable to use and hence prevent its implementation. Case examples showing
how to practice in a client-centred fashion were rated as the most effective
method of barrier removal.
PMID- 10695166
TI - Validity and community utility of the Canadian Occupational Performance Measure.
AB - This study addressed the validity and community utility of the Canadian
Occupational Performance Measure (COPM) (Law et al., 1991; 1994; 1998): a measure
that now represents a national standard in clinical practice and research in
occupational therapy in Canada. The study employed a crossectional design.
Participants for the study were former consumers of occupational therapy
services, recruited from the Queen's University catchment area (Kingston, North
Bay, Oshawa, Perth, Peterborough). A sample of 61 disabled individuals living in
the community were recruited. Each individual was sent a package of self
administered measures including the Satisfaction with Performance Scaled
Questionnaire, the Reintegration to Normal Living Index, the Life Satisfaction
Questionnaire, and the Perceived Problems List. An interview was also arranged
with the project coordinator, which was based on the COPM and the Consumer
Utility Questionnaire. Multivariate analyses showed that construct validity was
supported; scores on the COPM were significantly related to theoretically related
constructs: satisfaction with performance, reintegration to normal living and
life satisfaction. In addition, criterion validity was supported. A majority of
participants (53%), when asked about problems of daily living, spontaneously
reported at least one of the problems raised on the COPM. Community utility was
evaluated highly by participants, 75% of whom found the COPM useful in
identifying and rating their problems, and 100% of whom reported no problems in
understanding the COPM.
PMID- 10695167
TI - [Utilization of lifting equipment and slings in occupational therapy].
AB - The occupational therapist is frequently involved in the allocation process of
lifting devices for clients with severe physical disabilities who are living in
the community. The aim of this paper is to introduce a conceptual framework to
help therapists prescribe lifting devices, including the slings. First, factors
influencing the decision to prescribe such an aid are analysed based on the
concepts of the Canadian Model of Occupational Performance (Canadian Association
of Occupational Therapists, 1997). When working with clients toward maximizing
their transfer skills, occupational therapists will take into account different
aspects such as the characteristics of the client, the environment and the
equipment, as well as the time allocated to complete the activity. Secondly, the
notion of the work situation outlined by an organization specializing in work
safety measures is used as a guide for transfer evaluation. From this viewpoint,
the introduction of the lifting device occurs along a continuum of progressive
loss of independence and is determined by degrees of personal independence, human
assistance as well as technical assistance required to perform transfers.
Finally, advantages and disadvantages of using lifting devices in a home setting
are presented as a conclusion to the study.
PMID- 10695168
TI - A conceptual model for the development of professional behaviours in occupational
therapists.
AB - The ever-changing, dynamic practice environment coupled with increased consumer
needs and awareness create an atmosphere that requires optimal professionalism
from occupational therapists. Professionalism requires specific knowledge,
attitudes, and values--all manifested by professional behaviours. The authors
assume that professional behaviours mature through a natural developmental
process; a process that requires careful nurturing on the part of educators and
clinical supervisors. Based on this assumption, the authors propose this
conceptual model based on Erikson's life cycle stages. The model implies that
occupational therapy professional behaviours develop sequentially through stages
that begin during the educational process of occupational therapists, and
progress throughout their career. The purpose of this model is to provide a
framework for educators and supervisors to nurture professional behaviours in
students and novice clinicians, and to continue their own professional growth.
PMID- 10695169
TI - Development of a tool to measure clinical competence in occupational therapy: a
pilot study?
AB - Clinical competence is generally defined as a combination of knowledge, skill and
professional behaviour. It is typically assessed using written tests, direct
observation, chart audit, client satisfaction surveys and supervisor ratings.
This paper describes the development and evaluation of a chart-stimulated recall
(CSR) measure that combines the methods of chart audit and clinician interview to
assess the clinical competence of practicing occupational therapists. The CSR
tool was developed using the Canadian Guidelines for Client-Centred Practice and
taps global domains of competence: use of theory, assessment, program planning,
intervention, discharge planning, follow-up, program evaluation, clinical
reasoning and professional behaviours. This pilot study involved two independent
raters/interviewers who assessed twelve occupational therapy clinicians on two
occasions using a random sample of client cases/records on each occasion Results
indicate that the CSR tool is not only reliable and valid, but also sufficiently
generic to be used in a variety of practice settings as a global measure of on
the-job performance.
PMID- 10695170
TI - Reflections on a renaissance of occupation.
AB - At the close of the 20th century, there is a renaissance of occupation in
occupational therapy and occupational science. Kielhofner (1992) offers an
intraprofessional explanation that the growing interest in occupation recaptures
occupational therapy's lost identity. An extraprofessional explanation is that
postmodern ideas and social practices have helped to create a societal context in
which a renaissance of occupation is welcome. Postmodernism raises questions and
awareness of power, diversity, temporality, and situatedness in which normative
ideas of occupation as paid work can be challenged. Since occupation is of
primary concern to occupational therapy and occupational science, the authors
reflect on postmodernism and its influence on a renaissance of occupation in
these two fields. These reflections consider what such a renaissance means for
occupational therapists and occupational scientists in the 21st century.
PMID- 10695171
TI - The occupation of gardening in life-threatening illness: a qualitative pilot
project.
AB - This qualitative pilot study was completed as an exploratory study of the meaning
of gardening using attention restoration theory. Three women with breast cancer
who garden for leisure were recruited from a cancer support group. Each
participant was interviewed at her home on two occasions. To complement the
qualitative data, participants also completed the Perceived Restorativeness Scale
(PRS) (Hartig, Korpela, Evans, & Garling, 1996). The interviews revealed six
major themes some of which were concerned with the interactions between the
gardener and the garden, and others which focused on gardening within the context
of having cancer. The qualitative and quantitative outcomes supported the
perspective of attention restoration theory. Spirituality was interwoven
throughout the comments of two participants but was less important for one
participant. The implications of this study for practice and future research are
discussed.
PMID- 10695172
TI - Ethical decision-making made easier. The use of decision trees in case
management.
AB - Case managers have never before faced the multitude of difficult ethical dilemmas
that now confront them daily. Legal, medical, social, and ethical considerations
often fly in the face of previously reliable intuitions. The importance and
urgency of facing these dilemmas head-on has resulted in clear calls for action.
What are the appropriate legal, ethical, and professional parameters for
effective decision making? Are normatively sensitive, but also practically
sensible protocols possible? In an effort to address these concerns, Alternatives
for the Older Adult, Inc., Rock Island, Illinois established an ethics committee
to look into possible means of resolving or dissolving commonly occurring
dilemmas. As a result of year-long deliberations, the committee formulated a
decision-making strategy whose central apparatus is the decision tree--a
flowchart of reasonable decisions and their consequent implications. In this
article, we explore the development of this approach as well as the theory that
underlies it.
PMID- 10695173
TI - Cost effectiveness of a high-risk pregnancy program.
AB - This article presents an evaluation of an innovative community-based, case
management program for high-risk pregnant women and their infants. A 7-year
analysis of the Medicaid claims from 182,196 pregnant women and those for 140,088
infants was conducted. The findings showed improved birth outcomes and a steady
decrease in the cost of care for both pregnant women and their infants.
Recommendations are made concerning implementation of this program in other
settings with other clients.
PMID- 10695174
TI - Off the beaten track: MSN education for a changing health care environment.
AB - Given the dynamic nature of the health care environment, what should be the focus
of graduate education in nursing? New advanced practice roles for nurses are
emerging, but few university-based educational programs exist to respond to the
need. In developing a Master's program, Baylor University School of Nursing
accepted the challenge to deviate from tradition by preparing a nurse who has the
advanced knowledge and skills necessary to proactively address the present and
future needs of health care in multiple settings and roles. This article
discusses this unique and creative program in patient care management. Outcome
evaluation reveals that students are attaining the terminal objectives, meeting
the outcome criteria, and readily securing employment.
PMID- 10695175
TI - Expedited service delivery: helping case managers to increase access to services
for the poorest older adults.
AB - Low-income older adults have historically received institutionally based care
when they were unable to care for themselves and there was a lack of sufficient
formal and informal support to allow them to remain in their own homes. In 1981,
revision of federal Medicaid legislation permitted states to provide home- and
community-based services (HCBS) for older adults at risk of nursing facility
placement in an attempt to prevent unnecessary placement and to offer choice.
However, Medicaid-HCBS applicants may have to wait up to 45 days or longer for
approval of their financial application. During those 45 days, the applicant may
enter a nursing facility because Medicaid-HCBS was not available soon enough to
prevent placement. This article presents research on an instrument to help case
managers initiate community-based in-home services for the lowest-income Medicaid
applicants within 3 to 5 days of initial assessment.
PMID- 10695176
TI - The Medicare home health benefit implications of recent payment changes.
AB - The interim payment system (IPS) for Medicare home health services, enacted in
the Balanced Budget Act of 1997, was intended to slow the growth of home health
expenses until HCFA could design a new prospective system. Instead, the IPS has
acted like a per-case payment system without case-mix adjustment. Its impact on
agencies, along with other policy pressures, has been first to slow and then to
reverse the dramatic expansion of the home health sector. In this paper, we
identify the impetus for payment changes in the recent history of the Medicare
home health benefit. We then present emerging evidence about the effects of IPS
and other recent policies on home health. Finally, we draw several lessons from
this experience for the impending prospective payment system.
PMID- 10695177
TI - Determining the relevance of a certification exam to home health care nursing
practice.
AB - Home health care is enjoying increased use and popularity. Unfortunately, in
today's cost-cutting environment, home healthcare is also subject to increased
scrutiny and inevitable reimbursement limitations. This is borne out by the
impact on home healthcare as a result of the Balanced Budget Act of 1997. Berke
(1998) reports that those at greatest risk for cutbacks in care are those that
can least afford it--the oldest, sickest, poorest, and most frail. Compounding
the financial dilemma that home health care clients face are multiple providers
of care, an unrealistic media presentation of health care, and less time for
anyone to provide psychosocial-focused care (Simmons, 1990). Home health care
clients have a desperate need for an advocate to provide expert navigation
through the health care system. Home health care providers are aware of and often
responsible for bridging gaps in health, medical benefits, and social services.
This article describes a process for determining the relevance of a certification
to community nursing clinical practice--using the Advanced Certification in
Continuity of Care (A-CCC) exam as the example.
PMID- 10695178
TI - Designing through their eyes. Group homes for persons with Alzheimer's disease.
PMID- 10695179
TI - Preserving a healthy home.
PMID- 10695180
TI - Home modifications. Enabling environments, LLC, a fee-based service.
PMID- 10695181
TI - Project Metropair. A free home safety and security program in New York City.
PMID- 10695182
TI - Iron and alcohol content of traditional beers in rural Zimbabwe.
AB - OBJECTIVES: To determine the concentrations of iron and alcohol in traditional
beer, as well as how these may be related to the brewing process. DESIGN: Cross
sectional study. SETTING/SUBJECTS: Rural communities living in four of Zimbabwe's
nine provinces. MAIN OUTCOME MEASURES: Ionic iron concentration and alcohol
concentration in 94 different types of alcoholic beverages prepared in rural
areas, and 18 commercially produced beers. RESULTS: The commonest types of
traditional beer were a seven day beverage called 'doro rematanda', a by-product
of this seven day beer called 'muchaiwa,' and a one-day beverage called
'chikokiyana'. Methods of preparation were similar in the four provinces. Median
(Q1, Q3) ionic iron concentrations were 52 (31 to 75) mg/L for the seven-day beer
(n = 51), 24 (18 to 36) mg/L for muchaiwa (n = 30) and 21 (17 to 63) mg/L for
chikokiyana (n = 13). In contrast, ionic iron concentrations in 12 samples of
commercially prepared clear beers were 0.1 mg/L and in commercial opaque beer
were 3.6 mg/L. Mean (SD) alcohol concentration in traditional beer was 4.1 g/100
ml (+/- 0.873) compared to 2.8 g/100 ml +/- 1.394) in the muchaiwa and 3.6 g/100
ml (+/- 1.445) in the one day brew, chikokiyana. Mean alcohol concentrations in
the three commercial beers are reportedly 3.5 g/100 ml in the opaque beer (Scud),
and 4.7 to 5.0 g/ml in clear beer (Zambezi and Castle lagers). CONCLUSIONS:
Several preparation methods lead to traditional fermented beverages with very
high iron concentrations. Measures to prevent dietary iron overload should
include all of these beverages in their scope.
PMID- 10695183
TI - Bioavailability of rifampicin in a separate formulation and fixed dose
combination with isoniazid NIH: a case for a fixed dose combination (FDC) for the
treatment of tuberculosis.
AB - OBJECTIVES: To study and compare the bioavailability of rifampicin (RIF), in two
locally manufactured formulations; an FDC and a separate formulation and an
imported FDC formulation. DESIGN: Open within subjects, single blind cross over
study. INTERVENTIONS: Each volunteer subject, acting as their own control,
received the two fixed dose combinations and the separate formulation with the
same amount of 450 mg RIF. MAIN OUTCOME MEASURES: Cmax (peak drug concentration
achieved), Tmax (time at which peak drug concentration is achieved), T1/2el
(biological half-life of elimination) and area under the curve (AUC) for zero to
10 hours and zero to infinity. These are obtained from plotting plasma
concentration against time. RESULTS: There was a significant difference in the
Cmax between free and RIF combined with INH (6.1 and 7.6 mg/l respectively) and
no significant difference in the other parameters measured, of the local
products. Comparison of the local products and imported product showed no
significant difference in AUC but significant differences in T1/2el, C max and
Tmax (p = 0.003, 0.041 and 0.025 respectively). CONCLUSION: The Zimbabwe
manufactured and the German products had "demonstrable bioavailability" as
defined by the International Union Against Tuberculosis and Lung Diseases
(IUATLD). The local manufacturer appeared to have the technological capability to
produce a registrable combined RIF/INH table to be used in the treatment of
tuberculosis and to prevent the irrational use of RIF.
PMID- 10695184
TI - Aero-allergen sensitisation patterns amongst atopic Zimbabwean children.
AB - OBJECTIVE: To characterize children presenting with atopic conditions using the
RAST test. DESIGN: Retrospective descriptive study. SETTING: General paediatric
clinic in the private sector. SUBJECTS: 84 children aged below 12 years, who had
the RAST test, who presented to a general paediatric clinic between 1993 and 1998
with atopic conditions for care. RESULTS: The median age for all children in the
study was 52 months. Forty eight were male and 36 female. Eczema (33.9%) was the
most frequent clinical diagnosis especially in those less than 24 months of age,
followed by asthma (25.5%), allergic conjunctivitis (24.0%) and allergic rhinitis
(15.6%). Total IgE was not statistically significantly associated with clinical
diagnosis(p = 0.889), age of the child (p = 0.102), gender (p = 0.687) or
absolute eosinophil count (p = 0.318). The commonest allergens identified were
dust mite (Dermatophygoides pteronissinus and D. farinae) and Bermuda grass.
While antibody reaction to weeds, particularly plantain, were also common, these
reactions were mostly mild to moderate. Allergy to cats and moulds was rare.
CONCLUSION: In the absence of routine testing for specific allergens avoidance of
dust mite and Bermuda grass seem important strategies in the management of
difficult children with atopy. There is need for a prospective study to shed more
light on the allergens that cause these common atopic conditions in our
environment.
PMID- 10695185
TI - The impact of an inadequate municipal water system on the residents of Chinhoyi
town, Zimbabwe.
AB - OBJECTIVE: To assess the use and impact of the water reticulation system in
Chinhoyi on its residents. DESIGN: Cross sectional and case series studies.
SETTING: Chinhoyi town. SUBJECTS: 600 Chinhoyi residents. MAIN OUTCOME MEASURES:
Practices and perceptions of Chinhoyi residents on the water system, and
distribution of water-related diseases per area of residence. RESULTS: Out of 600
respondents, 565 (99.3%) had access to piped water and 558 (98.0%) to flush
toilets. Breakdowns of water supply and functioning of toilet facility were
reported by 308 (77.0%) and 110 (28.0%) respondents in the previous six months,
respectively. Main complaints of Chinhoyi residents were about low water quality
(36.2%), inadequate sewage system (31.3%) and environmental pollution (26.5%).
Cases of water-related diseases were not associated with natural water bodies.
CONCLUSIONS: Chinhoyi residents have good access to the municipal water and an
adequate sanitation system. However, low quality of the water, frequent system
breakdowns and the degradation and loss of amenity of the environment impair
their quality of life.
PMID- 10695186
TI - Tuberculosis liver abscess in an HIV-infected patient.
PMID- 10695187
TI - Hardly a harmless analgesic.
PMID- 10695188
TI - The need for a regular comprehensive health surveillance on industrial workers.
AB - The movement of people during some of their daily occupations and activities
releases an amount of dust into the air. Even dust that has settled on floors and
flat surfaces is made airborne by air currents. Of greater concern is the dusty
environment caused by the operations within the workplace, such as handling of
dusty materials, machining, cutting, drilling, milling, rock blastic and
pounding. Fortunately, a lot of the dust is harmless except when present in high
concentrations when it can cause some discomfort. At such levels it is termed
'nuisance dust'. However, some form of dusts are distinctly harmful, giving rise
to impairment of lung function and pneumoconiosis (dust-induced changes in the
lung).
PMID- 10695189
TI - Oh no, not nitric oxide!
AB - Nitric oxide (NO) is a unique, endogenous regulatory molecule that is involved in
a wide variety of physiological processes in multiple organ systems. This simple
gas functions as a cellular messenger in a broad range of biological activities
that include blood pressure regulation, immunomodulation and neurotransmission.
It has also been implicated in a number of homeostatic functions in the
cardiovascular system: it is a significant determinant of basal vascular tone
and, in addition is thought to regulate myocardial contractility and platelet
aggregation. Dysregulation of NO mediated effects have been implicated in the
pathogenesis of essential hypertension, atherosclerosis, and the hypotension
associated with septic shock. This review will focus on these multiple effects of
NO in the cardiovascular system.
PMID- 10695190
TI - Hypotension and bedside leukocyte reduction filters.
PMID- 10695191
TI - Uses and misuses of percentages.
PMID- 10695192
TI - Risk factors for neonatal mortality: Harare Central Hospital Neonatal Unit-
Zimbabwe.
AB - OBJECTIVE: To assess risk factors for neonatal mortality in a tertiary level
neonatal unit. DESIGN: Case control analysis of routine neonatal data for 1998.
SETTING: Harare Central Hospital Neonatal Unit. SUBJECTS: All neonates delivered
at Harare Maternity Hospital and admitted to the neonatal unit for care between
January and December 1998. MAIN OUTCOME MEASURE: Neonatal mortality in hospital.
RESULTS: A total of 5,305 neonatal admissions were studied of which 19.3% died in
hospital. The median age at death was two days (Q1 = 1, Q3 = 3) and the median
age at hospital discharge was 3 days (Q1 = 1, Q3 = 6). Risk factors for mortality
were un-booked mother odds ratio (OR) 2.36 (95% CI = 1.98 to 2.81), breech
delivery OR: 1.76 (95% CI = 1.39 to 2.22), low birth weight OR: 4.67 (95% CI =
3.92 to 5.57), prematurity OR: 2.36 (95% CI = 2.09 to 2.66), congenital
malformations OR: 2.80 (95% CI = 1.72 to 4.53) and birth asphyxia OR: 1.79 (95%
CI = 1.51-2.12). Being admitted for respiratory distress was associated with
better survival OR: 0.22 (95% CI = 0.17 to 0.28). Having a Caesarian section was
also protective OR: 0.60 (95% CI = 0.47 to 0.76). Mother's age, parity, time of
delivery and sex were not significantly associated with mortality odds ratios
(95% CI) of 1.07 (0.86 to 1.34), 0.94 (0.78 to 1.13), 1.10 (0.93 to 1.30) and
0.89 (0.78 to 1.03) respectively. On regression analysis birth weight greater
than 2,500 g, being un booked and breech delivery were predictive of mortality
with OR (95% CI) of 0.99 (0.99 to 0.99), 1.31 (1.12 to 1.61) and 1.15 (1.04 to
1.28) respectively. CONCLUSION: Low birth weight is the highest risk factor for
mortality in this tertiary level hospital. Strategies targeted at low birth
weight infants such as antenatal corticosteroid use, improved intrapartum care,
appropriate antibiotic use, improved efficiency and access to neonatal intensive
care will have the most impact on neonatal mortality.
PMID- 10695193
TI - Highlights of extranodal lymphomas in Ibadan, Nigeria.
AB - OBJECTIVE: To find out the pattern, trend and site distribution of extranodal
lymphomas in Ibadan. DESIGN: Case series. SETTING: Department of Pathology,
University College Hospital. SUBJECTS: All cases of malignant lymphomas with
extranodal manifestations between 1981 and 1998. MAIN OUTCOME MEASURES: Frequency
and distribution of primary extranodal lymphomas. RESULTS: Extranodal lymphomas
constituted 9.8% of non-Hodgkin's lymphomas(NHLs) during the period, increasing
from 8.5% of NHLs from 1980 to 1990 to 12.4% from 1991 to 1998. During the entire
18 year period the nasal/nasopharynx, gastro-intestinal tract (GIT), tonsils and
skin were the most commonly affected sites constituting 20.2%, 19.3%, 14.3% and
13.4%, respectively of all extranodal lymphomas. However, between 1980 and 1991
the GIT was the most commonly affected site (26.1%) followed by the
nasal/nasopharyngeal region (11.6%). The involvement of the nasopharyngeal area
during the second period of the study accounted for 32.0%. CONCLUSION: The
reasons for this changing trend are unknown and the significance of HIV infection
in this regard is uncertain.
PMID- 10695194
TI - Laparoscopic cholecystectomy in black patients at Ga-Rankuwa Hospital: a
feasibility study.
AB - OBJECTIVE: To determine feasibility and outcome of laparoscopic cholecystectomy
for Black patients in Ga-Rankuwa Hospital and to analyse the type of stones
harvested. DESIGN: Cross sectional description study. SETTING: Ga-Rankuwa
Hospital/Medunsa, South Africa. SUBJECTS: 79 patients who presented with
cholelithiasis over a six year period. MAIN OUTCOME MEASURES: Successful
performance of laparoscopic cholecystectomy on the subjects. RESULTS: 39
laparoscopic cholecystectomies were performed with seven conversions (18%
conversion rate). Forty open cholecystectomies were also performed. Post
operative stay after laparoscopic cholecystectomy averaged 3.5 days and that of
the open converted group 6.9 days (p < 0.001). Two patients returned with
persistence of symptoms following laparoscopic cholecystectomy. Twenty gall
stones were analysed; 17 were of the cholesterol type and three of the black
pigment type. CONCLUSIONS: Laparoscopic cholecystectomy is feasible in the Black
populace of Ga-Rankuwa Hospital. The majority of gallstones are of the
cholesterol type.
PMID- 10695195
TI - Beliefs about sexual relationships and behaviour among commercial farm residents
in Zimbabwe.
AB - OBJECTIVES: To describe beliefs of farm residents about sexual relationships and
sexual behaviours within these relationships, as a basis for understanding how
these beliefs may influence sexual behaviour; and to document gender differences
in these beliefs. DESIGN: Cross sectional descriptive study. SETTING: Three
commercial farms in Mashonaland Central Province, Zimbabwe. SUBJECTS: Purposive
convenience sample of 218 adult (age 18+, or ever-married) residents on the
commercial farms. MAIN OUTCOME MEASURES: Views towards celibacy, wife
inheritance, condom use, infertility, extra-marital affairs. RESULTS: 85% of
respondents felt marriage was a cushion against HIV/AIDS. The majority (87.6%)
viewed wife inheritance as improper; 37.6% felt that it facilitated the spread of
HIV. Sixty two percent viewed condom use in marriage as unacceptable, and the
majority of respondents felt that infertility was a problem in a person's life,
with men being less likely than women to indicate this (OR: 0.26; 95% CI: 0.10 to
0.67). Male respondents expressed greater ability than their female counterparts
to take protective steps in the event of suspecting STD/HIV/AIDS in their spouse.
More male than female respondents felt they could leave marriage against
perceived risk of infection with HIV from their partner (OR: 2.20; 95% CI: 1.22
to 4.00). CONCLUSION: Perceptions of wife inheritance are positive when viewed
against known ways of HIV transmission. There is need for further work to allow
women to express their integrity as individuals in their relationship with men,
as a strategy to promote their reproductive health. Determinants of condom
acceptance need further understanding because condom use is one of the effective
ways of curbing the spread of HIV/AIDS.
PMID- 10695196
TI - Sporadic Peutz-Jeghers syndrome in a Nigerian.
AB - Peutz-Jeghers syndrome is a rare condition of muco-cutaneous pigmentation and
polyposis of the gut. Reports of its occurrence from the Black world have been
infrequent. A case is presented of an 18 year old Nigerian girl with pigmentation
of the inner lips and soles of both feet, and recurrent attacks of abdominal pain
necessitating two surgical procedures for intestinal obstruction with removal, in
both cases, of polyps. Problems of complications and therapeutic modalities are
discussed.
PMID- 10695197
TI - Images in cardiovascular medicine: ruptured aneurysm of the sinus of Valsava.
AB - A 27 year old woman presented with a two year history of cardiac symptoms.
Echocardiographic examination revealed a ruptured aneurysm of the sinus of
Valsava. Of note the patient was known to be HIV positive.
PMID- 10695198
TI - Why beta blockers should be used in heart failure.
AB - Beta blockade may be beneficial for most patients with congestive cardiac failure
(CCF) whether due to ischaemic or idiopathic dilated cardiomyopathy (DCM),
although they are more effective if the CCF is idiopathic. Beta blockers are
additive to angiotensin converting enzyme (ACE) inhibitors in their effects on
CCF. Beta blockers have been shown in most studies to increase ejection fraction,
cardiac output, and exercise capacity and are sometimes capable of resolving
almost all the symptoms of heart failure. Treatment should begin with the
smallest possible dose and this should be gradually increased to the maximum
tolerated level.
PMID- 10695199
TI - Informed consent for blood transfusion.
PMID- 10695201
TI - Use of a medical decision support system to improve the preoperative diagnosis of
prostate cancer with pelvic lymph node metastases.
AB - BACKGROUND: We evaluated the effects of a medical decision support system on the
preoperative diagnosis of prostate cancer with pelvic lymph node metastases.
METHODS: The preoperative accuracy of staging prostate cancer with pelvic lymph
node metastasis by the prostate cancer expert system (PCES) for 43 patients was
compared to the accuracy of staging performed by 2 urological attending
physicians and 5 residents, to test the validity of the PCES. The effect of PCES
consultation on physicians' staging for prostate cancer with pelvic lymph node
involvement was evaluated. RESULTS: In the diagnosis of prostate cancer with
pelvic lymph node metastasis, PCES was significantly more accurate than the two
attending physicians alone (p = 0.042; p = 0.008). All the urological residents'
diagnoses were significantly less accurate than those of the PCES. After PCES
consultation, all the urological residents increased diagnostic specificity
significantly. Most residents usually used PCES for consultation only after the
attending physician or department asked for the results. CONCLUSION: Owing to an
increased ability for preoperative diagnosis of prostate cancer with pelvic lymph
node metastasis, as supported by the PCES, some unnecessary pelvic
lymphadenectomies may be avoided.
PMID- 10695200
TI - Myocardial effects of beta-agonist stimulation in rats with chronic left
ventricular dysfunction treated with an angiotensin-converting enzyme inhibitor.
AB - BACKGROUND: This study measured morphological and hemodynamic changes and renin
angiotensin responsiveness of the left ventricle (LV) to beta-agonist stimulation
in a Sprague-Dawley rat model of myocardial dysfunction produced by coronary
artery ligation. METHODS: The LV function and papillary muscle mechanics were
measured after 12 weeks of captopril treatment (2 g/l in drinking water)
following left coronary artery ligation or a sham operation. Fifty-two rats were
divided into three groups: those with sham operations, those with small infarcts
(infarct size [IS] < 30% LV) and those with large infarcts (IS > or = 30% LV).
RESULTS: The results showed that LV end-diastolic pressures were elevated in the
large-infarct group regardless of treatment with the angiotensin-converting
enzyme inhibitor (ACEI), and the LV weight was reduced in the ACEI-treated rats.
In addition, the uninfarcted LV posterior papillary muscle of the large-infarct
rats showed an impaired response to isoproterenol stimulation, including the
developed tension, positive and negative rate of tension development, time to
peak tension, and time to half relaxation. CONCLUSION: Chronic captopril
treatment improved isoproterenol-stimulated muscle isometric function in rats
following myocardial infarction, possibly through the beta-receptor pathway.
PMID- 10695202
TI - A comparative study of various fixation methods for mandibular fracture.
AB - BACKGROUND: Internal rigid fixation for mandibular fractures has been recognized
as a reliable method for obtaining osteosynthesis. It may allow for early active
physiotherapy and resumption of normal function. However, few studies have
compared the various fixation methods. METHODS: From January 1993 through
December 1997, 101 patients with mandibular fractures, who were selected for
study, received treatment using various fixation methods at the Craniofacial
Center, Chang Gung Memorial Hospital. The fixation methods included plate
fixation in 44 patients, lag screw fixation in 30, combined plate and lag screw
fixation in 15, and wire fixation in 12. Clinical data assessment was performed
by reviewing hospital records. For assessment of the long-term surgical results,
the patients were asked to complete a questionnaire including questions which
specifically targeted history regarding occlusion, mastication, facial asymmetry,
width of mouth opening, and general appearance. RESULTS: The outcome assessment
showed statistically different results among the groups. The wire group required
intermaxillary fixation more often and for a longer duration compared to the
groups using plates and/or lag screws. The plate, lag screw, and combined plate
and lag screw fixation groups had better total outcome scores, in particular for
long-term dental occlusion and mastication function. CONCLUSION: This study shows
that for mandible fractures, the more rigid types of fixation methods, i.e.,
plates and screws or lag screws, can offer better short and long-term outcomes.
PMID- 10695203
TI - Surgical outcome of combined phacoemulsification and trabeculectomy.
AB - BACKGROUND: A retrospective study was undertaken to evaluate the results of
phacoemulsification, intraocular lens implantation, and trabeculectomy in
patients with cataracts coexisting with glaucoma. METHODS: This study consisted
of 20 eyes from 19 patients. Fifteen eyes had chronic angle-closure glaucoma and
5 eyes had primary open-angle glaucoma. All cases were followed for a minimum of
6 months (range, 6 to 16 months). The mean preoperative intraocular pressure
(IOP) was 17.3 +/- 4.5 mmHg. The mean preoperative visual acuity was 0.05 +/-
0.19. The mean number of preoperative antiglaucoma medications per patient was
2.3. RESULTS: Postoperatively, all patients except for one no longer required
antiglaucoma medication. The mean IOP was 10.7 +/- 3.7 mmHg one month
postoperatively and 13.7 +/- 4.3 mmHg at the final follow-up visit. Vision
improved in 80% of the patients and remained unchanged in 20%. The failure to
achieve improvement was due to advanced optic atrophy. The mean level of
surgically induced astigmatism at the final visit was 0.98 +/- 0.91 diopters as
calculated by vector analysis. Various extents of fibrin exudate was found in 10
eyes (50%). The most serious postoperative complication, occurring in one eye
(5%), was temporary hypotony with moderate choroidal effusion, which later
resolved spontaneously. CONCLUSION: Combined phacoemulsification and
trabeculectomy is an effective and safe approach for obtaining good visual
rehabilitation and glaucoma control.
PMID- 10695204
TI - Clinical implication of atypical squamous cells of undetermined significance with
or without favoring high-grade squamous intraepithelial lesion on cervical
smears.
AB - BACKGROUND: The cytologic diagnosis of atypical squamous cells of undetermined
significance (ASCUS) on a cervical smear usually makes clinicians unsure of how
to manage the patient and follow-up on her condition. We attempted to define the
clinical implication of qualifying the cytologic diagnosis of ASCUS as either
favoring a high-grade squamous intraepithelial lesion (HSIL) or not in an effort
to provide management guidelines. METHODS: From January through May 1997, 65 of
5792 women who had cervical/vaginal smears taken at Kaohsiung Chang Gung Memorial
Hospital were diagnosed as having ASCUS. Thirteen of the 65 cases of ASCUS
favored an HSIL, based on nuclear abnormalities in atypical metaplastic and
parakeratotic-type squamous cells. All these 65 patients were evaluated in our
outpatient clinic by a second cervical smear, colposcopy, and colposcopically
directed biopsies and/or endocervical curettage. The median length of the follow
up period was 19 months (range, 16 to 21 months). RESULTS: Of the 52 patients
evaluated for ASCUS smears without favoring HSIL, 6 (11.5%) had a low-grade SIL
(LSIL), 1 (1.9%) had cervical intraepithelial neoplasia grade II (CIN II), and 1
(1.9%) had invasive squamous carcinoma. Of the 13 patients with a cervical
cytologic diagnosis of ASCUS favoring HSIL, 1 (7.6%) had immature metaplasia, 2
(15.4%) had LSIL, 2 (15.4%) had CIN II, 6 (46.2%) had CIN III, and 2 (15.4%) had
invasive squamous carcinoma. CONCLUSION: For patients with a cytologic diagnosis
of ASCUS favoring HSIL, more aggressive interventions, such as colposcopy
directed biopsy, endocervical curettage, or even conization, should be performed
promptly. However, those without features favoring HSIL may be evaluated with
regularly repeated smears.
PMID- 10695205
TI - Laparoscopic colectomy is superior to laparotomy for reduction of disability in
patients with colorectal adenoma.
AB - BACKGROUND: This study was to evaluate disability after laparoscopic colectomy in
patients with colorectal adenomas as compared to disability after laparotomy.
METHODS: Patients who underwent laparoscopic colectomy for colorectal adenoma
were compared to patients who underwent laparotomy for the same problem by the
same surgeons during the same time period in Cleveland Clinic Florida. A standard
questionnaire was used to assess disability which included the number of days to
return to partial activity, full activity, and work. RESULTS: Twenty-nine
patients who underwent laparoscopy were compared with 31 patients who underwent
laparotomy. There were no significant differences in age (70.4 vs 72.5 years) (p
= 0.405) or gender (M:F 13:16 vs 20:11) (p = 0.126) between the laparoscopy and
laparotomy groups. The operative time was longer for the laparoscopy group than
the laparotomy group: 170 vs 131 minutes (p = 0.014). However, the duration of
postoperative ileus, hospitalization, time until return to partial activity, time
until return to full activity, and time off of work were significantly shorter in
the laparoscopy group than in the laparotomy group: 3.3 vs 5.2 days, 6.2 vs 8.7
days, 2.3 vs 4.2 weeks, 4.4 vs 9.3 weeks, and 3.7 vs 7.3 weeks, respectively (p <
0.041 for all). Although the incidence of postoperative complications was not
significantly different (24% for laparoscopy vs 29% for laparotomy, p = 0.325),
the incidence of postoperative prolonged ileus was statistically significantly
lower in the laparoscopy group (3% vs 26%, p = 0.027). CONCLUSION: Laparoscopic
colectomy for patients with colorectal adenoma can reduce postoperative ileus,
postoperative hospitalization, and disability in terms of a quicker return to
partial activity, full activity, and employment. Laparoscopic colectomy should be
considered for all patients who have colorectal adenomas which require resection.
PMID- 10695206
TI - Comparison of nasal trauma associated with nasopharyngeal airway applied by
nurses and experienced anesthesiologists.
AB - BACKGROUND: Insertion of a nasopharyngeal airway by nurses is considered to be
invasive. We compared the incidence and severity of nasal injury associated with
nasopharyngeal airway insertion by trained nurses to those by anesthesiologists
to determine the safety of inserting a nasopharyngeal airway by nurses in
cardiopulmonary resuscitation (CPR). METHODS: One hundred and sixteen male and 96
female patients scheduled for general anesthesia were included in the study. The
male and female patients were randomly assigned to two groups respectively.
Anesthesia was induced with sodium thiopental and fentanyl intravenously. The
patients were then ventilated with a bag-valve-mask by trained nurses or
anesthesiologists. In the unsuccessfully ventilated patients, nasopharyngeal
airways were inserted to facilitate subsequent ventilation. The nasopharyngeal
airway, oropharynx, and nostrils were then examined. The incidence and severity
of nasal trauma induced by trained nurses or by anesthesiologists were compared.
RESULTS: The study revealed that nasopharyngeal airways applied by trained nurses
did not induce more severe nasal trauma than those by anesthesiologists.
CONCLUSION: We suggest that nasopharyngeal airways may be applied safely by
trained nurses in CPR.
PMID- 10695207
TI - Enterovesical fistula: experiences with 41 cases in 12 years.
AB - BACKGROUND: A retrospective analysis of enterovesical fistula treated at Chang
Gung Memorial Hospital was conducted to determine the optimal diagnosis and
management of this disease. METHODS: The records of 41 patients who presented
from 1984 to 1996 and had a final diagnosis of enterovesical fistula were
retrospectively reviewed. The etiology, symptoms on presentation, diagnostic
tools, and modality of treatment were analyzed. RESULTS: The majority of these
cases were associated with malignancy (38, 92.7%), and the others with
diverticulitis (2, 4.9%) and iatrogenic causes (1, 2.4%). In those with
malignancy, 15 patients (39.5%) were found to have tumor recurrence. The most
frequent symptom in enterovesical fistula was fecaluria (58.5%), followed by
abdominal pain (22%) and dysuria (14.6%). Diagnostic tools included the barium
enema, cystography, and cystoscopy; these methods could identify the fistula in
63.2%, 60%, and 53.8% of the patients, respectively. Methods of management
included diversion only (39%), one-stage fistula repair (36.6%), and watchful
surveillance (24.4%). CONCLUSION: Enterovesical fistula should be considered if
fecaluria, pneumaturia, or persistent non-specific urinary tract infection
present as the initial complaint. A thorough surgery for a possible underlying
malignancy is mandatory when confronted with enterovesical fistula, since the
incidence of inflammatory bowel disease is low in this area. An abdominal
computer tomography (CT) scan, barium enema, and cystogram can be useful
diagnostic tools. Treatment of this entity should be individualized according to
each patients clinical status.
PMID- 10695208
TI - Anterior knee pain after intramedullary tibial nailing.
AB - BACKGROUND: Currently, intramedullary nailing is a well-accepted method for
treating tibial shaft fractures, but some patients complain of anterior knee pain
after surgery. Multiple factors may influence this troublesome complication.
METHODS: This was a retrospective analysis of the medical records of 200 patients
who were treated with intramedullary nailing after tibial shaft fractures. Sixty
four patients complained of knee pain after surgery. We evaluated the knee pain
in relation to the surgical approach, radiographic readings, and the type of nail
used. RESULTS: Among the 64 patients, 45 (70%) received central approaches and 19
(30%) received paramedial approaches (p = 0.0002); 46 patients (72%) showed nail
protrusions on radiographs and only 18 patients (28%) were without nail
impingement (p = 0.0001). Forty-three patients (67%) received Kuntscher nail
fixation and just 21 patients (33%) had interlocking nail fixation (p = 0.0015).
CONCLUSION: The use of the central patellar tendon splitted approach, nail
protrusion observed on radiographs, and the insertion of a non-locking
intramedullary nail were all significant risk factors for anterior knee pain
after surgery. All these risk factors should be avoided in tibial nailing to
decrease the problem of postoperative knee pain.
PMID- 10695209
TI - Evaluation of peribulbar anesthesia in encircling scleral buckle surgery and its
postoperative pain course.
AB - BACKGROUND: Retrobulbar anesthesia is considered effective in ocular surgery but
it can give rise to serious complications. We used peribulbar anesthesia with sub
Tenon's irrigation to perform encircling scleral buckling for retinal detachment,
as it could reduce the complications caused by retrobulbar anesthesia. We also
recorded the course of pain for 72 hours after surgery. METHODS: Thirty patients
who were diagnosed with rhegmatogenous retinal detachment were treated with an
encircling scleral buckle. The surgery was performed with peribulbar anesthesia
with occasional sub-Tenon's irrigation. We evaluated the patient's pain with a
visual analogue scale after surgery at 30 minutes, 1 hour, 2 hours, 4 hours, 6
hours, 12 hours, 24 hours, 48 hours, and 72 hours. RESULTS: In 24 cases (80%),
the anesthesia was complete with the peribulbar block. Only 6 patients (20%)
needed sub-Tenon's irrigation and four of them felt no pain after augmentation.
Although all the surgical procedures proceeded without problem, two of the
patients felt pain and were uncomfortable during the surgery. No serious
complications occurred. The course of pain peaked 6 hours after surgery when 26
patients (86.7%) felt pain and 12 patients (40%) were uncomfortable (pain score >
or = 5). Forty-eight hours after surgery, 9 patients (30%) still felt pain but no
one felt uncomfortable. CONCLUSION: Peribulbar anesthesia can be used safely in
encircling scleral buckling for retinal detachment. The postoperative pain is
maximal 6 hours after surgery and becomes mild (pain score < or = 4) after 48
hours.
PMID- 10695210
TI - Neonatal vallecular cyst: report of eleven cases.
AB - BACKGROUND: Vallecular cyst is fairly uncommon in neonates and infants. Although
benign in nature, it may cause severe airway obstruction and even death. This
study retrospectively analyzed the clinical manifestations of vallecular cyst in
neonates and discussed its management. METHODS: From June 1993 through January
1997, 11 cases of vallecular cyst were collected and reviewed retrospectively.
There were 8 male infants and 3 female infants. Their clinical manifestations,
age at the onset of symptoms, age at diagnosis, and surgical management were
analyzed. Fibrolaryngoscopy was used for preoperative diagnosis and postoperative
follow-up. RESULTS: The infants' initial presentations were inspiratory stridor,
respiratory distress, noisy breathing, feeding difficulty, and failure to thrive.
There was a high incidence of patients with coexisting signs of laryngomalacia
(10/11). Ten patients received laryngomicrosurgery with CO2 laser for deroofing
the cyst. Additional supraglottoplasty was performed at the same time in 4
patients with laryngomalacia type A + C and in one patient with severe
laryngomalacia type C. Their symptoms all resolved soon after surgery. The
phenomenon of laryngomalacia also disappeared. There has been no recurrence up to
the present. CONCLUSION: Although fairly uncommon, vallecular cyst should be
included in the differential diagnosis of congenital laryngeal stridor in
neonates. The use of fibroendoscopy can promptly diagnose vallecular cyst and any
synchronous airway lesions. Although most of the synchronous laryngomalacia (type
C) in this study was secondary to vallecular cyst, we suggest that
supraglottoplasty be taken into consideration during cyst deroofing when the
signs and symptoms of laryngomalacia type A are also present.
PMID- 10695211
TI - Renal autotransplantation for ureter stricture and renovascular disorders.
AB - BACKGROUND: Renal autotransplantation is an established therapy in cases of renal
vascular lesions, tumors of the kidney and ureter, complex ureteral lesions, and
kidney trauma. It has been a significant technical innovation, aiding the
urologist in his great effort to preserve renal function by conserving renal
tissue. We report our experience with autotransplantation in 4 patients. The
indications, techniques, and results of renal autotransplantation in relation to
our own experience are discussed. METHODS: The patients included 3 women and one
man. The average age of the patients was 35 years old, with a range from 20 to 54
years. One patient had Takayasu's arteritis, the second had Nutcracker syndrome
with flank pain and hematuria, the third a complicated long ureter stricture, and
the fourth patient a renal artery saccular aneurysm. RESULTS: The average
operation time was 7 hours (4.5 to 8.5 hours), and the cold ischemia time was
about 88 minutes (45 to 150 minutes). Three of the autografts resumed normal
renal perfusion, and in the fourth patient the renal autograft was lost due to
vascular thrombosis. CONCLUSION: Renal autotransplantation is a feasible method
for the surgical treatment of renal and ureteral lesions. To avoid postoperative
ureteral sloughing and subsequent urinary fistulas, the ureter can be left intact
to preserve the ureter blood supply. However, in the case of a complicated
vascular reconstruction procedure, it appears to be appropriate to divide the
ureter and have the kidney completely free, thus avoiding back-flow perfusion
from the intrinsic and intercommunicating blood supply in the ureteral wall,
which may result in vascular thrombosis and subsequent autograft failure.
PMID- 10695212
TI - Usefulness of pediatric flexible bronchoscopy in the early diagnosis and
postoperation evaluation of vascular rings: report of three cases.
AB - Vascular rings are a diagnostic and therapeutic challenge for pediatricians. Many
diagnostic modalities contribute to the detection of these rare congenital
vascular anomalies. The role of flexible bronchoscopy is still being debated. We
present 3 cases to emphasize the usefulness of pediatric flexible bronchoscopy
(PFB) in the early diagnosis and postoperative evaluation of vascular rings. In
patient 1, PFB was performed before conventional techniques were available. A
right aortic arch with a retroesophageal aortic diverticulum and mirror-image
branching was later confirmed. In patients 2 and 3, pulmonary artery slings could
not be detected clearly by imaging studies before PFB was performed. PFB was
arranged again postoperatively for these 2 patients, because of difficulty
weaning patient 2 from ventilator support and persistent respiratory distress in
patient 3. In conclusion, we expect that more vascular rings will be diagnosed
using PFB. This instrument is also useful in making a decision for surgery, and
for detecting associated tracheobronchial anomalies preoperatively, assuring
appropriate correction intraoperatively, and monitoring the condition of vascular
rings postoperatively.
PMID- 10695213
TI - A new technique for generating a computer-aided design and computer-integrated
machining crown: case report.
AB - A new technique for producing a Computer-Aided Design and Computer-Integrated
Machining Ceramic Reconstruction crown is presented. After completion of the
tooth preparation, an "optical" impression of the tooth was made with a charged
couple device camera, and the electronic image was transferred to a computer
screen. The "proposed" crown was electronically designed on the screen by the
operator, and a proper prefabricated ceramic block was selected and used as
milling material. A miniature milling machine then fabricated the crown from the
ceramic block. The marginal adaptation and the contour of the crown were
verified, and an external shading technique was utilized to improve the
esthetics. The prepared tooth and crown were acid-etched, and the crown was
cemented with a dual-curing composite luting agent. Once bonded in place, the
occlusion was adjusted and the crown polished and finished. The advantage of this
technique is that it eliminates the traditional laboratory casting procedure and
corresponding laboratory fee while utilizing materials with superior physical
properties for maximum strength and esthetics.
PMID- 10695214
TI - A huge 6.2 kilogram uterine myoma coinciding with omental leiomyosarcoma: case
report.
AB - Surgery for massive abdominal tumors is both interesting and challenging. We
present a case involving a multiple uterine myoma weighing 6.2 Kg which coincided
with omental leiomyosarcoma. To our knowledge, this is the first report of this
type of condition in the English literature. A 44-year-old nulliparous woman had
suffered from abdominal pain for a long time. A huge abdominal mass was palpated
on physical examination. Computed tomography scanning revealed a huge pelvic
abdominal mass with the possibility of small bowel loops invaded by the mass. A 6
cm omental mass was incidentally found during the subsequent hysterectomy
procedure. Perforation of the urinary bladder occurred during the dissection of
adhesion. Resection of the omental mass, wide wedge resection of the invaded
small bowel, primary repair of the bladder, and hysterectomy were performed. The
final pathologic diagnosis was uterine leiomyomata with omental leiomyosarcoma.
The patient returned home on postoperative day 14 and was well at the 18-month
follow-up examination. The challenge of these tumors lies in their proper
diagnosis and surgical management. More case reports and follow-up studies are
needed to confirm the efficacy of their management.
PMID- 10695215
TI - Octreotide treatment for a malignant islet cell tumor with variable hormone
secretion: case report.
AB - It is well known that an islet cell tumor can secrete multiple hormones depending
on its cell type. We report the case of a 70-year-old woman who initially
presented with peptic ulcer symptoms, an elevated serum gastrin level, and
multiple liver tumors. Liver biopsy and distal pancreatectomy were performed, and
the pathological diagnosis was malignant islet cell tumor. Additionally, the
immunohistochemical staining revealed scattered positivity for gastrin, and then
also positivity for insulin 14 months later. A subsequent hypoglycemic episode
and elevated serum gastrin and insulin levels suggested that the disease had
developed into a condition of multiple hormone secretion. The plasma gastrin and
insulin levels decreased from 584 pg/ml and 90.8 microIU/ml to 49.1 pg/ml and
20.9 microIU/ml, respectively, 5 days after treatment with subcutaneous
octreotide 100 micrograms every 6 to 8 hours. In addition, follow-up computed
tomography showed shrinkage of the metastatic liver tumors. In conclusion, we
found a case of malignant islet cell tumor with variable hormone secretion which
could be effectively controlled with octreotide.
PMID- 10695216
TI - Adult Citrobacter freundii meningitis: case report.
AB - Citrobacter is a distinct group of Gram-negative bacilli belonging to the
Enterobacteriaceae family. Central nervous system (CNS) infections due to
Citrobacter are uncommon, though they occur more frequently in neonates and young
children. In adults, Citrobacter meningitis is extremely unusual with only 6
cases reported in the literature before 1998. This rare CNS infection has been
seen in patients with head trauma, following neurosurgical procedures, and in
those who are immunocompromised. Of the patients in the 6 reported cases, only
one developed multi-antibiotic resistant Citrobacter CNS infection. Adding to
this small number of reported cases, we report an adult case of post
neurosurgical meningitis and subdural empyema caused by multi-antibiotic
resistant Citrobacter freundii and also review the literature related to this
infection. Antimicrobial therapy with imipenem and third-generation
cephalosporins failed to result in cerebrospinal fluid sterilization in our
patient. Because of the use of broad-spectrum antibiotics, multi-antibiotic
resistant Citrobacter species have developed in this nosocomial CNS infection and
now present a therapeutic challenge. Therefore, further clinical studies are
needed to determine updated therapeutic modalities for treating this life
threatening infection.
PMID- 10695217
TI - Radical resection and intraoperative radiotherapy for a recurrent endometrial
cancer after prolonged remission following aggressive salvage therapy: case
report.
AB - The prognosis of recurrent endometrial carcinomas is generally poor, except for
isolated vaginal relapse. We report a case of recurrent endometrial cancer in a
58-year-old woman who initially received a type I extended hysterectomy with
bilateral salpin-go-oophorectomy and bilateral para-aortic and pelvic lymph node
dissection. The first recurrence occurred in the left parametrium 7 months after
the primary surgery. The salvage therapy consisted of radiotherapy combined with
hormonal therapy (tamoxifen and Megace). Complete remission was achieved
initially. Subsequently, the patient accepted six courses of chemotherapy
(cisplatin and Adriamycin) for progressive elevation of cancer antigen 125 (CA
125). The CA-125 levels remained elevated with titers fluctuating around 100 U/ml
until a second recurrence at the left iliac 75 months following salvage therapy.
The second salvage treatment consisted of maximal debulking of the pelvic mass
and intraoperative radiotherapy (IORT) followed by four courses of chemotherapy
with paclitaxel and carboplatin. Complete remission was again accomplished, with
clinical investigations and molecular markers returning to normal. The patient
has been clinically free of disease for more than 2 years since the second
relapse of cancer. In this particular case, we found that repeated recurrence
could occur after a long complete remission following salvage therapy; however,
the disease could be recontrolled with further aggressive salvage efforts. A
multimodality approach with combinations of radical resection, IORT, and
paclitaxel-based chemotherapy can be offered to patients with localized recurrent
or repeatedly recurrent endometrial carcinoma after previous cisplatin-based
chemotherapy and pelvic radiation.
PMID- 10695218
TI - Alien hand syndrome: report of two cases.
AB - Alien hand syndrome (AHS) refers to the occurrence of apparently purposeful
movements in the hand which are independent of volitional control. Two subtypes
of AHS have been proposed: frontal AHS, with grasp reflex and compulsive
manipulation of tools by the dominant hand, and callosal AHS, which occurs in the
nondominant hand and is characterized mainly by intermanual conflict. Here, we
report two cases of frontal-type alien hand syndrome with symptoms of reflexive
grasping, impulsive groping, and apraxia (in case 1), and compulsive manipulation
of tools (in case 2). Brain computed tomography revealed a left anterior cerebral
artery (ACA) territory infarct and multiple small infarcts of both hemispheres in
patient 1 and a left ACA infarct in patient 2. The involuntary movements were
bothersome to these patients in their daily activities. Both patients attended
conventional physical and occupational therapies, and patient 2 received
additional biofeedback training. Follow-up studies showed the spontaneous
grasping behavior was still present in patient 1 and AHS had subsided in patient
2. We also describe a potentially effective technique involving biofeedback for
patients with alien hand syndrome.
PMID- 10695219
TI - Blunt trauma-induced internal thoracic artery injury: case report.
AB - We report the case of a 54-year-old male motorcyclist with an apparent grade IV
liver injury and life-threatening hemomediastinum and right hemothorax following
blunt deceleration trauma. Massive hemothorax and an unstable hemodynamic status
even under copious blood volume replacement made emergent surgical intervention
mandatory. A midline laparotomy was performed at first to rule out abdominal
bleeding accompanied by a diaphragmatic tear, but the procedure was soon
converted to a thoracotomy after finding an intact diaphragm and persistent
bleeding from the chest tube. An isolated internal thoracic artery (ITA)
transection was identified. It was actively bleeding and causing a huge anterior
mediastinal hematoma and had ruptured into the right pleural cavity. The bleeder
was controlled with suture ligation and the hemodynamic status was soon
stabilized. The patient recovered without significant sequelae. The rarity of
this kind of presentation is discussed, including both the ITA injury mechanism
and the problems posed in making an early and correct diagnosis.
PMID- 10695220
TI - Unusual dilatation of Virchow-Robin spaces: case report.
AB - Virchow-Robin spaces normally surround the perforating arteries that enter the
brain. These spaces are a well-defined sites where immunological reactions take
place and they may have implications in the pathogenesis of a number of
neuropathological conditions. We present the case of a 52-year-old woman who had
a history of complex partial seizures for 30 years. Her routine neurological
examinations and mini-mental tests had normal results. Magnetic resonance images
of this patient revealed unusual widening of the Virchow-Robin spaces up to 1.5
cm in diameter along the perforating medullary arteries in the white matter, more
so in the left hemisphere. Although it has been concluded that these large spaces
are a phenomenon of the normal aging brain and are unrelated to neurological
diseases, our patient had had epileptic seizures for 30 years. The large Virchow
Robin spaces of our patient might have been an incidental radiologic finding.
Their pathogenesis remains unclear, and their possible clinical relationship to
epilepsy deserves further pathological studies.
PMID- 10695221
TI - Schistosoma japonicum infection presenting with colon perforation: case report.
AB - Colon perforation can be caused by a variety of entities, including iatrogenic
trauma, tumors, ischemia, inflammatory bowel disease, and steroid use. Parasitic
infection rarely leads to colon perforation. Secondary peritonitis results from
mixed microorganism infection, including enterococci, enteric bacilli, and
anaerobes. A combination of an optimal antibiotic regimen and surgical
intervention is of paramount importance. Nevertheless, intra-abdominal infections
usually have a high mortality rate. Schistosomiasis occurs worldwide. S.
japonicum infection is endemic in Asia. The most common complications of
gastrointestinal schistosomiasis are periportal fibrosis, intestinal polyposis,
and bowel stricture. Rarely, schistosomiasis results in colon perforation. The
diagnosis of schistosome infections is based on ova in stool or tissue specimens,
and/or immunologic diagnostic tests. The most effective anti-schistosomiasis
agent is praziquantel. Herein, we describe an unusual case of colon perforation
associated with Schistosoma japonicum infection, which resulted in severe
peritonitis and led to the patient's death.
PMID- 10695222
TI - Airway obstruction in general anesthesia--two different episodes in the same
patient: case report.
AB - The case of a patient with Apert's syndrome (acrocephalosyndactyly) who had a
tracheostomy tube and who encountered two different episodes of critical airway
obstruction during two different general-anesthetic procedures for craniofacial
surgery is reported. The first episode, at the age of four, involved occlusion of
the uncuffed tracheostomy tube by a blood clot, which might have come from the
surgical field of the maxillary Le-Fort III advancement procedure. The second
episode was encountered during his emergence from the general anesthesia of a
degloving midface osteoplasty and a maxillary Le-Fort I osteotomy procedure 3
years later. Although a cuffed armored tube had been inserted through the
tracheostoma to prevent aspiration of blood from the surgical field, the armored
tube was plugged by a piece of granulation tissue that might have been dislodged
from the peri-stomal area. Factors that lead to tracheostomy tube obstruction,
their clinical features and preventive measures are discussed. We believe that
being alert to changes in the airway pressure, the ventilation pattern, and the
hemodynamic status is necessary during the administration of general anesthesia.
Precautions should be taken at all times, particularly for patients with a
tracheostomy.
PMID- 10695223
TI - Hemorrhagic gastric glomus tumor mimicks a leiomyosarcoma on both transabdominal
and endoscopic ultrasonography: case report.
AB - Glomus tumor is a benign tumor that arises from the modified smooth muscle cells
of the glomus body and usually occurs in the skin, particularly in the nail-beds
and fingertips. Gastric glomus tumor is a rare gastric submucosal tumor.
Endoscopic ultrasonography (EUS) is useful in differentiating the gastric
submucosal tumors, such as leiomyoma, leiomyosarcoma, lipoma, ectopic pancreas
and glomus tumor. On sonography, gastric glomus tumor appears as a homogeneous
hypoechoic or a heterogeneous low echoic pattern mixed with internal high echoic
spots. Here, we describe an unusual sonographic figure of a hemorrhagic gastric
glomus tumor on both EUS and high-resolution transabdominal ultrasonography
(TAU). This tumor was located in the gastric muscular layer. Sonographic
examination revealed a heterogeneous echogenicity with hyper- and anechoic areas,
which mimicked the echoic pattern of gastric leiomyosarcoma.
PMID- 10695224
TI - The socioeconomic burden of hospital acquired infections.
PMID- 10695225
TI - An analysis of 60 cases of culture bound syndromes.
AB - Of 60 cases of culture bound syndromes seen in psychiatry OPD, Dhat syndrome was
most common (76.7%), followed by possession syndrome (13.3%). Depression by the
most common associated psychiatric disorder. As the data on culture bound
syndromes in Indian subcontinent is less, this study calls for careful evaluation
of these patients psychologically to detect and treat the associated psychiatric
comorbidity appropriately.
PMID- 10695226
TI - Experience with quinine in falciparum malaria.
AB - During a period of 1 year from July 95 to June 96, 60 patients with falciparum
malaria were treated with quinine at Kasturba Medical College Hospital,
Mangalore. Of these, 24 patients developed adverse effects to quinine. They were
cinchonism (15) cardiotoxicity (10) hypoglycemia (9) hyperventilation (3)
hypersensitivity reactions (3) and hypokalemia (1). Cardiotoxicity was noted in 4
of the 7 patients who received intravenous quinine and all four had renal and
hepatic failure and prolonged Q-Tc on electrocardiogram. All 4 died of cardiac
arrhythmias, 2 had broad QRS tachycardia and 2 had sinus bradycardia. We conclude
that: 1. Quinine should be used cautiously in patients with impaired hepatic or
renal function and in those with prolonged QTc as it can lead to cardiotoxicity
in the form of I0 AV block, prolonged Q-Tc, broad QRS tachycardai or fatal
bradyarrhythmia. Dosage reduction to 5 mg/kg body weight in the patients seem to
be safer. 2. Hypoglycemia is a very frequent complication of quinine therapy and
special care and frequent blood sugar estimations are required especially if the
patient has vomiting. 3. Parenteral quinine is more likely to cause toxicity than
oral quinine as earlier described.
PMID- 10695227
TI - A study of serum bilirubin in neonates in relation to the maternal age.
AB - A comparative study of neonatal serum bilirubin levels was done in neonates of
different age groups of mothers. A total 122 healthy, new borns were selected for
the study, born at Queen Mary's Hospital, Lucknow. Mothers were divided into two
groups i.e. < 30 years and > 30 years of age. Samples of blood were collected
thrice, first on day 1 from cord blood, 2nd and 3rd on days three and five of
life from neonates by heel prick method, using small bore capillaries for blood
collection, serum bilirubin estimation were done by the method of Malloy & Evelyn
and Mean +/- SD were calculated. P-Value was observed between different age
groups. In both the groups of mothers i.e. < 30 years and > 30 years serum
bilirubin levels in their neonates raised to highly significant levels on day 3
(P-Value < 0.001) as compared to their cord blood serum bilirubin levels. On
comparing serum bilirubin levels in neonates of both the maternal groups, it was
observed that there is no significant difference between two groups on day of
birth and day day 5 but statistically significant difference was observed on day
3 (P < 0.05), serum bilirubin levels were higher in neonates of younger age group
mothers.
PMID- 10695228
TI - Sociomedical problems of institutionalised women.
AB - The inmates of this institute form a special group in the society which is a
reflection of various social pressures and problems. These institutionalised
female largely come from poor socioeconomic families and often from families with
serious social problems like family disharmony (30%), marital disharmony (20%),
poverty (10%), unwedmotherhood (8%), broken homes (51.1%) etc. 90% inmates had
one or more morbid conditions. Average number of morbid conditions per inmate was
2.16 at the time of study. Institution which assumes the custody of these women
should provide them with medical services towards the rehabilitation and
discharge of a healthy, productive, well adjusted citizens. An effective health
education programme comprising of nutrition education, sex education, personal
hygiene, alcohol and drug abuse should be specifically drafted and should be
undertaken for the inmates.
PMID- 10695229
TI - Knowledge and practices about HIV transmission among barbers of Nagpur City.
AB - The present study was carried out in south zone of Nagpur city to assess
knowledge and practices regarding HIV transmission of 375 barbers selected
randomly from three different categories of saloons. A significantly large
proportion of the roadside barbers were ignorant about modes of transmission of
HIV, particularly through the blades. The practices observed by barbers ae found
to be favourable for transmission of HIV, more so in roadside barbers. Hence it
can be concluded that practices observed by barbers may favour transmission of
HIV and there is a scope for educational intervention.
PMID- 10695230
TI - Dynamics of contraceptive use in a rural community of Haryana.
AB - A cross-sectional survey was carried out to study the dynamics of contraceptive
use in three villages of Raipur Rani block in district Panchkula, Haryana. A
female social worker interviewed 600 ever-married women aged 15-44 years using a
semi-structured interview schedule. More than 75% of the respondents were aware
about modern contraceptives. Fifty-nine percent of the couples had used
contraceptives. Among the 351 ever-users, the first contraceptive method used was
sterilization in 41.3%, condom in 35.6%, IUD in 17.9%, and oral pills in 5.1%.
Subsequently, many of them either discontinued or shifted to other methods. At
the time of survey, 236 (39.3%) were using a contraceptive. Most of the current
users (225) had opted for tubectomy, and only a few (4) had accepted vasectomy.
Supplies of contraceptives were obtained mainly from government hospitals and sub
health centres. Common reasons for discontinuation were perceived untoward
effects (37.1%), desire for more children (32.6%), and failure of the
contraceptive method (19.0%). Most of the respondents obtained contraceptives
from Government health posts. Counselling and follow-up services should should be
strengthened so that contraceptives are used regularly and effectively for longer
periods.
PMID- 10695231
TI - Delayed immunization against vaccine preventable diseases--factors responsible
among children under 5 years of age.
AB - In the present case-control study, out of the the eleven risk factors of delayed
immunization, only seven, namely family size, sex, number of children < 5 years,
material education, paternal education, distance from health centre and low socio
economic status were found to be significantly associated. The common causes for
delayed immunization were negligence on part of parents, unawareness about the
use of vaccine and sickness of child. Thus, health education of the parents is
recommended.
PMID- 10695232
TI - Bacteriological analysis of burn sepsis.
AB - A total of 114 opportunistic bacteria were isolated from 65 swabs from burn
sepsis. P. aeruginosa (53.8%) was the most common agent followed by S. aureus
(38.4%), Klebsiella Spp. (27.6%), Proteus (18.4%), E. coil (10.7%) and others.
The infection was monobacterial in 25 cases (38.4%) and polybacterial in 49 cases
(61.5%). P. aeruginosa was predominated in both monobacterial and polybacterial
infections. Ciprofloxacin (42.9%) was found to be the most effective
antibacterial agent. Results indicate that resistance in burn isolates is higher
and increasing day by day.
PMID- 10695233
TI - Management of drug resistant tuberculosis.
PMID- 10695234
TI - Importance of autopsy in prevention of epidemics.
AB - With resurgence of infectious diseases all over the globe, there is need for
constant surveillance and specially trained staff to expertly carry out autopsies
on suspected cases and determine the exact cause of death. Early and accurate
diagnosis is important in order to prevent worldwide spread of the disease.
PMID- 10695235
TI - Using antileukotrienes in asthma therapy.
PMID- 10695236
TI - Heart drug with 'viagra side-effect'.
PMID- 10695237
TI - Alcohol drinking patterns and medical care use in an HMO setting.
AB - The objective of this study was to examine the association of medical care use
(outpatient visits and hospitalization) with alcohol drinking patterns in a large
health maintenance organization (HMO). Data were gathered from a random sample of
10,292 adult respondents through a telephone survey conducted between June 1994
and February 1996. Findings indicate that current nondrinkers with no past
history of drinking had higher rates of outpatient visits and hospitalizations
than current drinkers. Among current drinkers, medical care use declined slightly
as drinking levels increased. Among nondrinkers, those with a drinking history
exhibited significantly higher use of outpatient visits and hospital care than
nondrinkers with no drinking history and current drinkers. Controlling for
demographic and socioeconomic factors, health status, and common medical
conditions in multivariate analyses suggests that nondrinkers with a drinking
history use more services because they are sicker than other nondrinkers or
current drinkers.
PMID- 10695238
TI - Behavioral health funding for Native Americans in Arizona: policy implications
for states and tribes.
AB - This article examines the principal structures and mechanisms used by federal and
state government to fund the behavioral health needs of Native American Indians.
Using Arizona as a case study, the article provides an overview of both federal
and state programs, especially Medicaid, discussing the problems and strengths of
each. The article concludes with a discussion of the policy implications of these
programs for both states and tribes, focusing on issues concerning administrative
complexity, tribal sovereignty, improving behavioral health services, and
assignment of financial risk.
PMID- 10695240
TI - Predicting service utilization with the Child and Adolescent Functional
Assessment Scale in a sample of youths with serious emotional disturbance served
by center for mental health services-funded demonstrations.
AB - This study investigated level of restrictiveness of living arrangements and
number of days in out-of-family care at six months postintake, based on the Child
and Adolescent Functional Assessment Scale (CAFAS), the Child Behavior Checklist
(CBCL), gender, age, and level of family income at intake. It was composed of
youths who met the criteria for serious emotional disturbance (SED) and were for
the most part living in families that are described as socioeconomically
disadvantaged. A multinomial logit model was used in the analysis of level of
restrictiveness of living arrangements, and an ordinary least squares (OLS)
regression model was conducted on number of days in out-of-family care. The CAFAS
score at intake was found to be a significant predictor of service utilization
between intake and six months and was a more consistent predictor than the CBCL.
Results suggest that the CAFAS can be used to match service needs with resource
allocation and to monitor performance-based outcome indicators.
PMID- 10695239
TI - Comparing provider perceptions of access and utilization management in full-risk
and no-risk Medicaid programs for adults with serious mental illness.
AB - This article compares provider perceptions of access to services and utilization
management (UM) procedures in two Medicaid programs in the same state: a full
risk capitated managed care (MC) program and a no-risk, fee-for-service (FFS)
program. Survey data were obtained from 198 mental health clinicians and
administrators. The only difference found between respondents in the FFS and MC
sites was that outpatient providers in the MC site reported significantly lower
levels of access to high-intensity services than did providers in the FFS site (p
< .001). Respondents in the two sites reported similar attitudes toward UM
procedures, including a strong preference for internal over external UM
procedures. These findings support the conclusion that through diffusion of UM
procedures, all care in the Medicaid program for persons with a serious mental
illness is managed, regardless of risk arrangement. Implications for mental
health services and further research are discussed.
PMID- 10695241
TI - Motivational versus confrontational interviewing: a comparison of substance abuse
assessment practices at employee assistance programs.
AB - The aim of this study was to conduct a quasi-experimental comparison of two
employee assistance program (EAP) assessment approaches with substance abusers:
confrontational interviewing (CI) and motivational interviewing (MI). A total of
176 EAP clients from 14 study sites met the study criteria, and 89 (51%) agreed
to participate in the study. At three and nine months postassessment, both the MI
and CI groups showed similar changes in readiness for change, completion of
initial treatment plans, and subsequent treatment. Most important, both the MI
and CI participants showed significant and comparable improvement on all of the
substance abuse baseline measures as well as measures of family-social well-being
and effects of drinking/drugging on work performance. The results open the door
for EAP counselors to use an empirically supported assessment style that is at
least as effective as the traditional confrontational approach.
PMID- 10695242
TI - Psychometric evaluation of an inpatient psychiatric care consumer satisfaction
survey.
AB - This study assessed the psychometric properties of a questionnaire designed to
measure consumer satisfaction with inpatient psychiatric care. To this end, 37
inpatient psychiatric units from across the United States agreed to participate.
The questionnaire was completed by 1,351 individuals, or a responsible party, for
an average response rate of 53%. The factor analysis identified six scales:
Nonclinical Services, Psychiatric Care, Staff, Medical Outcome, Patient
Education, and Program Components/Activities. The internal reliability of the
scales was high to moderate (.88 to .74). Results of a stepwise regression model
showed good criterion-related validity, explaining 58% of the variance in overall
quality ratings. Little shrinkage in this variance occurred when the model was
cross-validated. Also, differences in satisfaction levels were noted for select
facility and consumer characteristics. Results are interpreted as providing
support for the reliability and validity of a newly developed consumer
satisfaction survey for use in evaluating inpatient psychiatric care.
PMID- 10695243
TI - Distributive justice in Medicaid capitation: the evidence from Colorado.
AB - In 1995, the state of Colorado began a new funding program for the provision of
mental health services to Medicaid recipients. Medicaid funding was restructured
from a fee-for-service system into a capitated managed care system. The
restructuring altered the way in which mental health resources were allocated
within Colorado's mental health system. This article explores the ethical
principles inherent in the allocation of mental health resources within Colorado.
The allocation system before and after the capitation pilot is analyzed according
to three models of distributive justice. Under capitation, access to care
corresponds to egalitarian ideals, while service delivery and outcomes follow a
more utilitarian philosophy. Results from several empirical studies of the
Colorado Medicaid system are used to support this ethical analysis. The analysis
leads to the suggestion that the fair-opportunity rule may be a useful principle
for developing just distribution systems in other states in the future.
PMID- 10695244
TI - Cross-system service use among psychiatric patients: data from the Department of
Veterans Affairs.
AB - This study examines the cross-system use of non-Department of Veterans Affairs
(VA) services in a sample of psychiatric patients from the VA in 1990. Data were
collected over a two-week period on all mental health outpatients and included
demographic information, diagnoses, and self-reported use of non-VA services in
the previous two weeks and six months. In the entire sample, 10.6% and 23.3%
reported cross-system use in the previous two weeks and six months, respectively.
Predictors of cross-system use were lower VA utilization, a nonschizophrenic
diagnosis, not having a VA service-connected disability, and being female. These
data indicate that a substantial proportion of VA mental health patients are
using non-VA services. Utilization patterns indicate that they may be
substituting non-VA for VA services. These results are unlikely to be unique to
VA, and rates of cross-system use will likely increase in all health care systems
as financial restrictions increase.
PMID- 10695245
TI - Linking substance abuse and serious mental illness service delivery systems:
initiating a statewide collaborative.
AB - In the past, persons with serious mental illness and substance abuse often found
themselves in parallel systems of care that inadequately addressed their needs.
Recent advances have seen the development of an integrated approach to care for
these disorders in both the public and private sectors. While some state
departments of mental health have developed integrated systems of care for public
sector patients, no department appears to have developed such a system for both
public and private clients, and there appears to be no published journal report
of a model to induce cooperation by all stakeholders. This article outlines a two
step approach by the Massachusetts Department of Mental Health to foster
stakeholder cooperation in designing an integrated system of care for both public
and private clients with co-occurring disorders.
PMID- 10695246
TI - The Nexum: a modest proposal for self-guardianship by contract: a system of
advance directives and surrogate committees-at-large for the intermittently
mentally ill.
PMID- 10695247
TI - The liberal neutrality of living and dying: bioethics, constitutional law, and
political theory in the American right-to-die debate.
PMID- 10695248
TI - HIV-infected surgical personnel under the ADA: do they pose a direct threat or
are reasonable accommodations possible?
PMID- 10695249
TI - Cedar Rapids Community School District v. Garret F.: the court ruled. Congress,
now it's your turn.
PMID- 10695250
TI - A national epidemic, a national conversation, a national law: in support of
unique identifier reporting for HIV surveillance.
PMID- 10695251
TI - Federal gun storage legislation: will this keep guns out of the hands of our
children?
PMID- 10695252
TI - The Adoption and Safe Families Act of 1997: changing child welfare policy without
addressing parental substance abuse.
PMID- 10695253
TI - Supervisors beware: the Family and Medical Leave Act may be hazardous to your
health.
PMID- 10695254
TI - Elevated risk of tuberculosis by occupation with special reference to health care
workers.
AB - We conducted a study to evaluate tuberculosis (TB) risk in Japan by work
performed, either paid or unpaid. We collated information on sex, age, employment
category, occupation, and family history from 1120 registration cards of new TB
cases at two wards in Nagoya City over seven years (1989-1995). We used census
data and data from the Survey of Physicians, Dentists and Pharmacists conducted
in 1990 to estimate the population at risk by employment category and occupation.
Elevated TB incidence rates were observed for female nurses (SIR: 3.81; 95% CI:
1.97-6.65), clinical laboratory technicians (SIR: 25.00; 6.81-63.99), and males
without a paid job (SIR: 1.35; 1.20-1.53). A work environment conducive to
transmission may have increased the TB risk in female nurses and clinical
laboratory technicians. Male jobless people and institutionalized elderly
residents may have enhanced the TB risk for males without a paid job.
PMID- 10695255
TI - Yields and daily consumption of cigarettes in Japan in 1969-1996.
AB - Cigarette modification trends and the relationship between nicotine yields and
consumption in Japan were examined over the 27 years between 1969-1996. Data on
cigarette use were obtained from reports published by the government and tobacco
manufacturers. Over the study period, there has been a coherent pattern of
cigarette modification in Japan. The sales-weighted average yields have declined
from 20.7 mg tar and 1.64 mg nicotine/cigarette in 1969 to 8.7 mg tar and 0.72 mg
nicotine/cigarette in 1996. On the other hand, the average daily consumption per
smoker has continuously increased over the same period. Average nicotine yields
and daily cigarette consumption have significant negative correlations among both
males and females. This relationship was observed even after controlling for the
price changes of cigarettes over time. It is indicated that smokers have
compensated for reduced nicotine yields by increasing daily consumption. This may
have offset potential benefits of the continuous decline in tar and nicotine
yields to smokers' health.
PMID- 10695256
TI - Smoking behaviors and attitudes among school teachers in Mie, Japan.
AB - We conducted a questionnaire survey of public kindergarten, elementary and high
school teachers in Mie Prefecture, concerning smoking habits and attitudes from
November 1995 to February 1996. A self-reporting questionnaire was sent to
approximately 16,000 teachers and school employees. The questionnaires were
collected in a way which took into consideration the privacy of the respondents.
A total of 13,998 questionnaires were returned. The percentages of smokers among
the teachers were 44.7% for males and 3.1% for females, percentages which are
lower than those for the general Japanese population. Almost all of the men and
women agreed that anti-smoking education is needed. Most of those who did not
feel anti-smoking education was needed were smokers themselves. Seventy percent
of both men and women responded that anti-smoking education was a teachers' duty,
however, only thirty-six percent of the male and twenty-one percent of the female
teachers had actual experience at such education. Finally, almost all teachers
wish wish that schools were totally smoke-free or had a partial ban on smoking
and believe that school anti-smoking policies in Japan should be introduced.
PMID- 10695257
TI - Effects on mortality of getting the basic health examination under the Health
Services for the Elderly Act and modification of the effects by health status
among elderly persons in a rural community.
AB - This longitudinal study examines the effect on mortality of regular use of the
basic health examination under the Health Services for the Elderly Act and
heterogeneity of the effect according to levels of physical and mental health
status among community dwelling elderly persons. Of persons aged 65 and older who
lived in Otsuki town, Kochi prefecture, and completed a questionnaire survey
about health in February 1991, 1,470 survivors on the anniversary of the baseline
survey were followed by the end of March 1996. Regularity of getting the
examination was determined by the history of use of the examination in 1990 and
1991. Mortality reduction associated with annual use of the examination was
observed in both the 65-74 and the 75 and older age groups and the benefit got
smaller with advancing in age. In the 75 and older age group, the benefit from
annual use of the examination was restricted to persons having no impairment in
physical activities of daily living and those having favorable mental health.
Biennial use of the examination was associated with the same amount of mortality
reduction as annual use among persons having chronic conditions under treatment
in the 65-74 age group. Regular use of the basic health examination at old ages
is effective and the effectiveness varies by age range and level of functional
health status.
PMID- 10695258
TI - Prevalence of idiopathic hypoparathyroidism and pseudohypoparathyroidism in
Japan.
AB - A nationwide epidemiologic survey of idiopathic hypoparathyroidism and
pseudohypoparathyroidism was conducted in 1998 to clarify the prevalence of the
two disorders in Japan. From a total of 14,100 departments of pediatrics,
internal medicine, neurology, and endocrinology in whole Japan, 2952 (20.9%)
study departments were selected at random. Of these departments receiving the
first questionnaire, 1855 (62.8%) responded. From these departments 390 patients
with idiopathic hypoparathyroidism and 203 with pseudohypoparathyroidism who
visited the hospitals in 1997 were reported. The total numbers of patients were
estimated to be 900 (690-1100) for idiopathic hypoparathyroidism and 430 (330
520) for pseudohypoparathyroidism (95% confidence intervals in parentheses).
Using these data, the period prevalence of the diseases were 7.2 (5.5-8.8) per
million population in idiopathic hypoparathyroidism, and 3.4 (2.6-4.2) in
pseudohypoparathyroidism (95% confidence intervals in parentheses).
PMID- 10695259
TI - Relationship between the blood coagulation-fibrinolysis system and the
subclinical indicators of arteriosclerosis in a healthy male population.
AB - A cross-sectional observation was performed to assess the relationship between
the coagulation-fibrinolysis system and the subclinical indicators of
arteriosclerosis in a healthy male population. Subjects were 445 workers (18.9
49.4, Av. 36.2 yrs) in viscose rayon manufacturing factories in Japan.
Coagulation-fibrinolysis parameters determined were D-dimer(DD), thrombin
antithrombin III complex (TAT), tissue plasminogen activator (TPA), and
plasminogen activator inhibitor 1 (PAI1). The following indicators of
arteriosclerosis were examined; systolic and diastolic blood pressure (SBP, DBP),
stiffness parameter of the carotid artery using ultrasound (beta), pulse wave
velocity of the aorta (PWV), and a number of lacunar infarctions from brain MRI.
After age-stratification(-29, 30-39, 40+ yrs), the subjects were classified into
quartiles by coagulation-fibrinolysis parameters. The mean values of SBP and DBP
and beta and PWV, the prevalence of brain infarctions were compared across these
quartiles by means of analysis of variance, chi-square test, respectively.
Multivariate analysis was also employed to adjust other risk factors. In
conclusion, SBP and DBP and beta, PWV were elevated by increase of PAI1, TAT,
respectively, in the 40+ years group even after adjustment for other possible
risk factors. DD had no relation to any of the indicators of arteriosclerosis.
None of the coagulation-fibrinolysis parameters had any relation to brain
infarctions.
PMID- 10695260
TI - Exposure to Japanese cedar pollen in early life and subsequent sensitization to
Japanese cedar pollen.
AB - The effect of exposure to Japanese cedar pollen (JCP) in early life on subsequent
sensitization to it was evaluated. Specific IgE antibody to JCP was examined in
440-504 school children in a rural town each year during 1995-98. The amount of
dispersed pollen measured by a Durham sampler widely ranged from 165 to 5941
grains/cm2/year during this period. The amount had been measured during the
period of 1982-91 in which these children were born, and it also widely ranged
from 148 to 8566 grains/cm2/year. Children born during November to January, who
were exposed to JCP within 6 months of age, increased at the risk of
sensitization to JCP, especially severe sensitization, relative to those born in
the other months. Age-adjusted prevalence rate ratio (RR) of having a JCP-IgE >
or = 15 U/ml (control; < 0.35 U/ml) for children born in December to February
relative to children born in the other months was 1.74 (95% confidence interval;
1.06-2.87, examined in 1998), and for those born in November to January was 1.57
(95% CI; 1.00-2.46, examined in 1997). The risk of sensitization to JCP was low
for those born in May to July (RR = 0.42, 95% CI; 0.19-0.93, examined in 1998).
There was also a strong correlation between the amount of the dispersed pollen
during the period of 2-6 months after birth and the prevalence of sensitization
to JCP.
PMID- 10695261
TI - Long-term prognosis of patients with ulcerative colitis in Japan.
AB - Even though it is important in improving the quality of life to evaluate the long
term prognosis of patients with ulcerative colitis in comparison with the general
population, it is unknown in detail. One hundred and seventeen cases followed-up
for 10 years or more were evaluated to define the long-term prognosis of
ulcerative colitis by the person-years method. The estimated number of death (E)
was 14.5, and the observed number of death (O) was 20. The O/E ratio was 1.38 and
confidence interval was 0.84-2.13, showing no significant difference between E
and O. Evaluation of change in the O/E ratio at 5-year intervals revealed a
decrease in both the males and females, with a significant difference observed
between the ratios in 1960 and 1965 (each p < 0.05). Generally, the death rate
was significantly higher in the patients with ulcerative clitis than in the
general population between 1953 and 1965 but did not significantly differ
thereafter. On the other hand, the E from malignant tumors was 3.94, and the O
was 4; the O/E ratio was 1.02 and 95% confidence interval was 0.27-2.60, showing
no significant difference between E and O.
PMID- 10695262
TI - Randomized controlled trial of exercise training for older people (Sendai Silver
Center Trial; SSCT): study design and primary outcome.
AB - Physical exercise is expected to improve and maintain physical function in older
people, thus promoting health and preventing or postponing the onset of
disability in later life. The Sendai Silver Center Trial (SSCT) was a randomized
controlled trial designed to evaluate the efficacy of exercise training among
healthy free-living older people. Sixty-five eligible participants, aged from 60
to 81 years, were randomly allocated to an exercise group or a control group. The
subjects in the exercise group were asked to attend training classes at the
Sendai Silver Center, a municipal health and welfare facility in the center of
Sendai City, at least twice a week for 25 weeks. Each training class, lasting two
hours, started with a warm-up session, followed by an endurance session with a
bicycle ergometer, and a resistance exercise training session using rubber films,
and ended with a cool-down session. The subjects in the control group were asked
to attend recreational classes at the Center twice a month. There were no drop
outs or accidents during the intervention. Comparison of maximum oxygen
consumption (VO2max) before and after the 25-week intervention revealed a
significant increase in the exercise group (2.1 ml/kg/min) but no significant
change in the control group. Our result is equivalent to the participants
becoming younger in aerobic capacity by five years after six months of exercise
training.
PMID- 10695263
TI - Delays and continuation of hospital visits among HIV-infected persons and AIDS
cases in Japan.
AB - This study attempts to clarify the distribution patterns of delay between HIV
transmission and the first hospital visit among HIV-infected persons and AIDS
cases in Japan except those infected through blood products. Such hospital visit
patterns were analyzed, and the rates of reporting for HIV/AIDS surveillance
among diagnosed HIV-infected persons and AIDS cases in hospitals were shown. From
1991 to 1997, a survey and subsequent follow-up were conducted among HIV-infected
persons and AIDS cases diagnosed at 74 hospitals in Tokyo. The numbers of HIV
infected persons and AIDS cases were 590 and 208, respectively. The percentage of
patients whose estimated date of HIV transmission was obtained ranged 23-41%
among Japanese and non-Japanese HIV-infected persons and AIDS cases. Among these
patients, 28% to 86% showed a 3-year delay between HIV transmission and their
first hospital visit. The rate of HIV-infected persons who continued to visit
hospitals within 1 year after their first visit was 77% for Japanese and 45% for
non-Japanese; among those after 1 year or more following their first hospital
visit the rate was more than 80% among Japanese and over 70% among non-Japanese.
The rate of reporting to HIV/AIDS surveillance among diagnosed HIV-infected
persons and AIDS cases was 90% or more after 1994 in Japan. The delay between HIV
transmission and the first hospital visit was suggested to be very long. Not a
few patients stopped visiting hospitals after only a short time. Most diagnosed
HIV-infected persons and AIDS cases were reported to the surveillance system of
Japan.
PMID- 10695264
TI - Bernadine Healy, MD: President of the American Red Cross.
PMID- 10695265
TI - The relation between erythrocyte volume and folate levels is influenced by a
common mutation in the methylenetetrahydrofolate reductase (MTHFR) gene (C677T).
AB - BACKGROUND: The enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) plays an
important role in folate metabolism and folate-dependent reactions. Homozygosity
for a common polymorphism in the MTHFR gene (C677T, Ala to Val) is associated
with an increased risk of neural tube defects and hyperhomocysteinemia in
individuals with low folate levels. Homozygous carriers of the polymorphism with
adequate folate levels, on the other hand, seem to be at lower risk for
colorectal cancer. Homozygous carriers of the polymorphism (5-15% of the white
population) probably represent a subpopulation with increased folate needs.
Hematological sequelae of folate deficiency have been recognized for a long time.
However, no data exist concerning the relation between the C677T MTHFR
polymorphism, folate levels, and hematological parameters. METHODS: We
investigated associations between the C677T MTHFR polymorphism, folate levels,
total plasma homocysteine, and hematological parameters in 94 patients with
cerebrovascular disease (transient ischemic attack/minor stroke) and in 82
healthy subjects. RESULTS: Homozygous carriers (VV) of the polymorphism with low
folate levels showed significantly higher homocysteine levels than mutation
negative (AA) and heterozygous (AV) subjects (P = 0.038). Furthermore, VV
subjects in the lowest folate quartile exhibited significantly higher mean
erythrocyte volumes (MCV) and a tendency towards higher erythrocyte hemoglobin
content (MCH) than AA and AV subjects (P = 0.008 and 0.069, respectively).
Although MCV was not influenced by folate levels in AA and AV subjects, in VV
subjects a significant inverse correlation with folate levels could be
demonstrated (P = 0.544 and 0.020, respectively). CONCLUSION: We demonstrate an
association between the C677T polymorphism, folate levels, and hematological
parameters. The elevation of MCV in homozygous carriers of the polymorphism with
low folate levels indicates impaired DNA synthesis and/or methylation in these
subjects. Considering our data and the results of previous studies, the
polymorphism may have contrary effects on homocysteine metabolism and DNA
synthesis/methylation dependent on a subject's folate supply. Although the
polymorphism is disadvantageous in homozygous carriers with low folate levels,
its presence may be beneficial in individuals with adequate folate supply.
PMID- 10695266
TI - Soluble P-selectin as a marker of platelet hyperactivity in patients with chronic
obstructive pulmonary disease.
AB - A comparative analysis between soluble (s) P-selectin and von Willebrand Factor
(vWF) was performed in 40 patients with chronic obstructive pulmonary disease
(COPD) and 20 healthy subjects, with the aim of investigating whether the
occurrence of elevated levels of sP-selectin may reflect activation of platelets,
endothelial cells, or both. Plasma sP-selectin levels were significantly higher
in patients compared to controls (P < 0.01). Similarly vWF levels were elevated
in patients compared to healthy subjects, although the difference did not reach
statistical significance. Lipoprotein (a) [Lp(a)] levels were lower in COPD
patients than controls (P < 0.0001). The analysis of the correlation among all
the variables demonstrated that plasma sP-selectin did not correlate with vWE.
Conversely, plasma sP-selectin levels significantly correlated with either oxygen
(rho = -0.41, P < 0.05) or carbon dioxide (rho = 0.47, P < 0.05) tension. An
inverse correlation between serum Lp(a) and plasma sP-selectin levels (rho =
0.35, P < 0.05) was also observed. Moreover, increasing levels of sP-selectin in
COPD patients significantly correlated with the impairment of blood gas tensions.
In conclusion, the results obtained indicate the prominent platelet origin of
circulating sP-selectin, suggesting that sP-selectin might be considered a marker
of in vivo platelet activation in patients with COPD.
PMID- 10695267
TI - Autoantibodies from patients with idiopathic ataxia bind to M-phase
phosphoprotein-1 (MPP1).
AB - In an attempt to identify unique disease-related autoantibodies, the serum from
an ataxia and sensory neuropathy patient was used as a probe to isolate a 2.5-kd
cDNA from a HeLa expression library. The nucleotide sequence was 99% identical to
MPP1, a cell-cycle-related nuclear protein phosphorylated during mitosis.
Expression of the cDNA in an in vitro translation system yielded a recombinant
protein that migrated in SDS-PAGE at approximately 97 kd. This protein was
immunoprecipitated by the prototype human serum, by an immune guinea pig anti
MPP1 serum, but not by normal human serum or preimmune guinea pig serum. Western
blot analysis of HeLa cell proteins showed that the prototype human serum and
immune guinea pig antiserum recognized an approximately 225-kd protein,
suggesting that the isolated clone contained a partial cDNA. By indirect
immunofluorescence, the affinity-purified antibody and a guinea pig antiserum
reacted with nuclei of interphase HEp-2 cells and the cytoplasm of certain
neuronal cells. Sera from 10 of 25 unselected patients with ataxia, 1 of 30
patients with peripheral neuropathy, 1 of 50 multiple sclerosis patients, 0 of 20
amyotrophic lateral sclerosis, 0 of 10 children with postviral ataxia, 0 of 10
systemic lupus erythematosus patients, 0 of 3 patients with hereditary cerebellar
ataxia, 0 of 8 with ataxia telangiectasia, and 0 of 30 age- and gender-matched
controls immunoprecipitated the recombinant MPP1 protein. None of the patients
with anti-MPP1 antibodies had evidence of malignancy. This is the first report of
MPP1 as a target autoantigen in patients with idiopathic ataxia.
PMID- 10695268
TI - Effects of intra-VMN mianserin and IL-1ra on meal number in anorectic tumor
bearing rats.
AB - BACKGROUND: Tumor growth in animals and humans is associated with the onset of
anorexia and reduced food intake. We previously demonstrated that the
ventromedial nucleus of hypothalamus (VMN) plays a contributory role in mediating
cancer anorexia. Because serotonin and interleukin-1 (IL-1) are putative
mediators of cancer anorexia, we hypothesized that their influence on food intake
during tumor growth might occur via their action within the VMN. METHODS: To test
this hypothesis, 12 Fischer rats injected subcutaneously with 10(6) viable MCA
sarcoma cells (TB rats) and their nontumor-bearing controls (NTB, n = 13) were
studied. When anorexia developed, TB and NTB rats received bilateral intra-VMN
microinjections of the serotonin antagonist mianserin (200 nmol) or the IL-1
receptor antagonist (IL-1ra, 25 ng). Food intake and its determinants of meal
number and size were continuously recorded via a computerized device. RESULTS: In
NTB rats, intra-VMN mianserin did not affect food intake, whereas after IL-1ra or
vehicle a momentary decrease in food intake due to a predominant reduction of
meal size occurred. In TB rats, intra-VMN mianserin or IL-1ra selectively
increased meal number, leading to improved food intake. CONCLUSIONS: Data suggest
that intra-VMN serotonin and IL-1 are involved in influencing cancer related
anorexia.
PMID- 10695269
TI - Mechanism for the prevention of cholestasis involving cytochrome P4503A
overexpression.
AB - BACKGROUND: To clarify the preventive effect of taurohyodeoxycholic acid on liver
cholestasis induced by toxic bile acids in rats, we evaluated whether modulation
of cytochrome P4503A-linked oxidases is involved in the hepatic bile acid
retention and secretion mechanism. We investigated whether the safe or the toxic
taurochenodeoxycholic acid, administered singly or together, affects cytochrome
P450-catalyzed drug metabolism or biliary parameters. We also considered whether
the inhibition of the P-glycoprotein export pump by vinblastine might be related
to cytochrome P4503A overexpression. METHODS: Hydroxylation of testosterone and N
demethylation of aminopyrine were studied in subcellular rat liver preparations
after intravenous infusion of hepatoprotective and toxic bile acids administered
singly or together. Bile flow, calcium secretion, biliary enzymes activity, and
secretion rates of the endogenous and administrated bile acids were determined.
CYP3A-dependent monooxygenases were also measured in the same coinfusion model in
the presence of vinblastine. RESULTS: Although wide modulation of the activities
of different P450 subfamily of isoenzymes was seen, P4503A-associated
monooxygenases showed similar patterns in the various situations, i.e., induction
by taurohyodeoxycholic acid, reduction by taurochenodeoxycholic acid, and
protection (intermediate induction) in the coinfusion experiments. This
correlates well with biliary parameters demonstrating the hepatoprotective
ability of taurohyodeoxycholic acid. Coadministration of bile acids and
vinblastine significantly modifies CYP3A-linked activities. CONCLUSIONS: Bile
acid structure seems to be linked with hepatotoxicity/hepatoprotection and P4503A
modulation. Taurohyodeoxycholic acid could be therapeutic in cholestatic liver
disease by inducing P4503A; we can hypothesize that an associated P-glycoprotein
expression might facilitate biliary excretion of toxic taurochenodeoxycholic acid
accumulated in the liver during cholestasis.
PMID- 10695270
TI - Immediate early gene 2 of human cytomegalovirus increases interleukin 2 receptor
alpha gene expression.
AB - Previously, we demonstrated that the cytomegalovirus (CMV) immediate early 2
(IE2) gene product upregulates interleukin-2 receptor-alpha (IL-2R alpha) gene
expression. To further define this effect, we used a series of IL-2R alpha
promoter truncations to identify that the primary site of CMV IE2 activity was in
the region between -281 and -273 of the IL-2R alpha promoter, an area without
known transcription factor activity. Deletion of known transcription factor
enhancer elements resulted in a similar decrease in IE2-driven promoter
activation. This unique sequence from the IL-2R alpha promoter was shown to drive
a minimal promoter in the presence of IE2. These studies identify a new
transcription factor binding site in the IL-2R alpha promoter, which may be
specifically responsive to the CMV IE2 gene product. These studies also suggest
that one mechanism whereby CMV infection may result in organ transplant rejection
is through increased IL-2R alpha expression.
PMID- 10695271
TI - Human alveolar epithelial cells type II are capable of regulating T-cell
activity.
AB - Alveolar epithelial cells type II (AEC-II) express MHC class II on their surface,
an important prerequisite for antigen presentation. However, accessory signals
are required for an efficient T-cell activation. We therefore isolated AEC-II
from tumor-free sections of human lungs obtained by lobectomy/pneumectomy and
purified the cells by magnetic-activated cell sorting. Furthermore, we tested the
expression of CD54, CD58, CD80, and CD86 on AEC-II and evaluated their accessory
function (AF) in cell culture using a coculture of interleukin-2 (IL-2),
releasing Jurkat cells and AEC-II. An increased AF is documented by an elevated
IL-2 release and expressed as accessory index (AI). In 33 experiments the AF of
AEC-II proved to be highly variable. AI ranged between 0.3 and 17.1 with a median
of 1.4 (0.3-17.1). Forty-four percent (4-77) of the AEC-II expressed HLA-DR, 44%
(12-89%) of the cells expressed CD58, and CD54 was expressed by 55% (16-89%). AEC
II also expressed CD80 and CD86 (38% [0-77%] and 40% [4-68%], respectively).
Interestingly, AEC-II released high levels of TGF beta (1730 pg/mL [771-5876])
and the accessory index could be increased (approximately 2-fold) by the addition
of neutralizing anti-TGF beta antibodies or radiation. Thus, type II alveolar
cells express costimulatory molecules and are able to deliver costimulatory
signals for T cells, providing evidence that AEC-II are able to act as antigen
presenting and immunoregulatory cells of the lung. Additionally, the accessory
function of AEC-II is under the control of endogenously released TGF beta.
PMID- 10695272
TI - The public's health at the beginning of the century--challenges and
opportunities.
PMID- 10695273
TI - Public health in the commonwealth 100 years ago. 1940.
PMID- 10695274
TI - Kentucky State Board of Health biennial report. 1906-07.
PMID- 10695275
TI - Community assessment using the key informant method: a snapshot of some rural
communities from the perspective of community leaders.
PMID- 10695276
TI - Problems engendered by illegible medical records needs to be addressed.
PMID- 10695277
TI - The leadership role of the medical family in this century.
PMID- 10695278
TI - HLA diversity and infections.
PMID- 10695279
TI - Rural-urban differences in food and nutrient intake of Pakistani children.
AB - BACKGROUND: Global increase in urbanisation accompanied by increase in complexity
of nutritional problems is a cause of concern for most nations. OBJECTIVE: The
aim of this study was to assess the differences in frequency of food consumption
and nutrient intake of urban and rural Pakistani children. SETTING: Forty rural,
59 middle income urban and 81 affluent urban children belonging to the province
of Punjab. Children were recruited through schools in Lahore and Rayonpura, Kala
Shah-Kaku (Sheikhupura district). METHOD: Three-day estimated diet records were
kept by a total of 180, 10-12 year old school-children. The nutrient intake was
calculated by the nutritional analysis package COMP-EAT and analysed on SPSS. The
results of the three groups were compared. RESULTS: Consumption of chapati, eggs,
yoghurt and some of the traditional vegetarian snacks was very similar in all the
three groups. Consumption of lentils, cooked vegetables, paratha (fried Asian
bread) and tea decreased and that of milk, meat curry, chicken curry, chocolates,
cakes, ice-cream, fruit and raw vegetables increased with urbanization. As
compared with the rural children, the urban children had a higher mean daily
intake of calories, sugar, protein, total fats, cholesterol, calcium, sodium,
potassium, niacin, vitamin B12, folic acid, antioxidant vitamins A, C and E and
lower intake of total carbohydrates, fibre and starch. CONCLUSION: It is
concluded that although the macro-nutrient consumption pattern of rural children
appears to be heart healthy lower consumption of protective micro-nutrients by
them may put them at risk. In view of rapid urbanisation and its multidimensional
impacts on the health of the populations living in the urban areas of the
developing world, these dietary trends provide baseline information for health
professionals.
PMID- 10695280
TI - The clinical pattern of HER-2/neu oncogene overexpressing breast cancer in
Pakistani patients at initial presentation: an analysis of HER-2/neu positive
versus negative disease--a preliminary report.
AB - BACKGROUND: HER 2/new oncogene is an important prognostic marker in Breast Cancer
and has implications in therapy planning. OBJECTIVE: To describe the clinical
features of HER 2/new positive and negative Breast Cancer in the Pakistani
patient population and note clinical differences between the two groups if any.
DESIGN: A retrospective analysis of Breast Cancer cases at the Aga Khan
University, Hospital. METHOD: Immunochemical staining on formation fixed paraffin
embedded tissue using oxidase antiperoxidase method. A total of 152 Breast cancer
tissue samples were tested for HER-2/neu gene presence. Of these 43 (39%) samples
tested positive and 109 (61%) tested negative. A comparison of the two groups
revealed that only a few factors tested for either significance or borderline
statistical significance between the two groups. These factors included the
estrogen receptor status and the number of lymph nodes involved in the axilla.
The progesterone receptor status was of borderline significance. CONCLUSION:
Given the large number of factors tested it appears that there is no consistent
defining feature which helps to separate HER-2/neu positive versus HER-2/neu
negative cases with Breast Cancer.
PMID- 10695281
TI - Self-reported feeding advice by physicians for common childhood illnesses.
AB - BACKGROUND: A nutritious diet is important for recovery during illnesses. Dietary
advice by physicians and consumption of food by the patients are often based upon
their hot and cold concepts and beliefs about various foods rather than on
scientific basis. OBJECTIVES: To look at the food-advising behaviour of
physicians during illnesses and to know the maternal concepts about various foods
being hot or cold. METHODS: A questionnaire was served to the physicians
participating in a continuous medical education session held at the Aga Khan
University and Hospital, asking them to write the foods they advise or restrict
during different illnesses such as fever, jaundice etc. Mothers of sick children
suffering from diarrhea and other illnesses were also interviewed to know their
concepts about various foods. RESULTS: Six (10%) out of sixty physicians believed
in hot and cold concepts of the food. A variety of common foods were either
restricted or strongly recommended by 10% to 50% of these physicians without any
scientific basis, 23% physicians restricted fatty foods in jaundice, 17%
physicians restricted in cough and cold. Although the interviewed mothers
believed in hot-cold concepts of food but 55-63% of them were not sure what is
meant by hot or cold food. In spite of that 70-80% of these mothers classified
chicken, meat, egg, brinjal, masoor and mangoes are hot foods and rice, yogurt,
moong, banana and orange as cold foods. CONCLUSION: Hot-Cold concept of food
exists not only in mothers but also in physicians. Proper education regarding
food intake is mandatory for both mothers and physicians to ascertain adequate
intake of calories during sickness.
PMID- 10695282
TI - Immunization coverage in three districts of North West Frontier Province (NWFP).
AB - AIM: This community-based study was conducted to assess the progress of Expanded
Programme on Immunization (EPI) in North West Frontier Province (NWFP) of
Pakistan. METHOD: In this cross sectional survey, 120 randomly selected clusters
in 03 districts of NWFP were included, 2673 children in the age group 12-35
months of 2583 randomly selected families were visited. RESULTS: The results
showed that 65% of children were fully immunized, but out of them only half could
be verified by immunization, need of 2nd and 3rd dose and no faith in
immunization were the major causes of failure of immunization programme.
Moreover, mother too busy, absence of vaccinator and inconvenient place of
immunization were the obstacles pointed out by the parents. CONCLUSION: This
study suggests the areas where improvement can be made to achieve the real target
of immunization coverage. It is concluded that despite of more than 20 years of
efforts by EPI, the ultimate objectives have not been achieved.
PMID- 10695283
TI - Gastric carcinoma with lymphoid stroma: association with Epstein virus genome
demonstrated by PCR.
PMID- 10695284
TI - Endoscopic placement of esophageal prostheses for inoperable carcinoma of
esophagus.
PMID- 10695285
TI - Gender issue neglected aspect of health promotion in Pakistan.
AB - OBJECTIVE: To identify neglected aspects of primary health care activities and
propose effective strategies for better health promotion in Pakistan. METHOD: An
observation study was carried out from March-July, 1998 in a low-medium income
group in Karachi West in a primary health care set-up. RESULTS: Seventy-three
percent of female clients were influenced by the advice of male members of the
family, 22% followed the directions of elderly female member, 5% availed health
services on their own will. CONCLUSION: The Pakistani female community is
influenced strongly by the male members of the family in almost all health
related activities.
PMID- 10695286
TI - Prognostic indicators of childhood acute viral encephalitis.
AB - OBJECTIVE: To devise a set of clinical signs and laboratory parameters that would
help clinicians assess prognosis in patients and plan appropriate management.
METHODS: Medical records of 147 paediatric cases (with a discharge diagnosis of
acute viral encephalitis) admitted over a ten year period from 1987 to 1997 were
reviewed and relevant information collected on a data extraction form. RESULTS:
Of 147 patients, 24 (16.3%) died and 48 (32.7%) were left with severe
neurological deficits. A GCS (Glasgow Coma Scale) score between 6-10 had an
association with poor outcome (OR = 2.62, Chi-square = 5.57, p-value = 0.018) and
that a GCS score of > or = 5 was even more strongly suggestive of poor outcome
(OR = 5.49, Chi-square = 12.08, p-value = 0.0005). A history of having seizures,
for more than 3 days, also showed a strong association with poor outcome (OR =
3.66, Chi-square = 5.46, p-value = 0.019). CONCLUSION: Patients with an increased
risk of death and severe disability can be identified using a few guidelines. Of
these, a history of seizures of > 3 days and/or impaired consciousness (GCS < or
= 10), at the time of presentation to the hospital, constitute high risk. These
cases must be identified promptly and aggressive therapy initiated in order to
improve long term outcome.
PMID- 10695287
TI - Characterization of Streptococcus pneumoniae strains isolated from systemic
infections in children.
AB - Twenty-three cases of systemic pneumococcal infection diagnosed from October 1988
to September 1998 were analyzed retrospectively in order to characterize the
epidemiology of systemic pneumococcal infections. The clinical diagnosis of those
cases were 8 pneumonia, 8 meningitis, 3 septicemia, 3 septic arthritis, and 1
peritonitis. The patients ranged in age from 6 months to 21 years old (mean +/-
SD = 3 years, 6 months +/- 5 years, 2 months), and 61% of the patients were
younger than 24 months. Resistance to penicillin G (PCG) was detected in 57% of
all cases. Resistance to cefotaxime (CTX), imipenem (IPM), erythromycin (EM), and
clindamycin (CLDM) was 33%, 9%, 70%, and 65%, respectively. Of the 13 isolates
resistant to PCG, 2 were resistant to IPM, 11 to EM and 11 to CLDM. Serotyping
was performed on 17 isolates. The identified serotypes were 19 (6 isolates), 6 (5
isolates), 23 (3 isolates), 14 (2 isolates), and 5 (1 isolate). Eleven isolates
resistant to PCG were limited to serotypes 6, 19, or 23. One patient had a
recurrent episode of bacteremic pneumonia 7 months after the first episode.
Streptococcus pneumoniae isolates from both episodes were compared by serotyping
and pulsed-field gel electrophoresis with restriction digestion, and were
confirmed as the same strain.
PMID- 10695288
TI - [A trial of amantadine for the treatment of influenza A infection in children].
AB - We administered amantadine to 52 children for therapy and 3 children for
prophylaxis of influenza A infection from January to March 1998. Among the 23
children in the therapy group with proven influenza A/H3N2 infection, 15 patients
(60%) allayed fever within 3 days but 9 (40%) had persistent fever for more than
4 days after administration of amantadine. Seven of these nine patients (40%)
received amantadine within 2 days after the onset of fever. Two of these nine had
secondary bacterial infections. One child had insomnia as side effect. We
concluded that administration of amantadine for therapy is safe and effective, if
given to patients without secondary bacterial infections in the first 48 hours of
the illness.
PMID- 10695289
TI - [Evaluation of the rapid detection test for influenza A and B viruses using
neuraminidase activity].
AB - The ZstatFlu test (ZymeTx, USA) is a rapid detection kit for influenza A and B
viruses. This test is based upon the reaction between viral neuraminidase from
influenza viruses and a chromogenic substrate. The clinical performance of the
ZstatFlu test was determined by comparison with viral isolation in cell culture.
A total of 176 respiratory specimens from 172 pediatric patients with influenza
like illnesses during the 1998/99 season were tested. Influenza viruses were
recovered from 97 specimens (type A: 6, type B: 91) in cell culture. ZstatFlu
demonstrated 67.4% sensitivity (29/43) and 62.7% specificity (37/59) for throat
swabs. Of the 22 ZstatFlu-positive, culture-negative throat swabs tested by RT
PCR, 18 were positive by RT-PCR. ZstatFlu showed 48.1% sensitivity (26/54) and
90.0% specificity (18/20) for nasopharyngeal aspirates. Of the two ZstatFlu
positive, culture-negative nasopharyngeal aspirates tested by HI titer of paired
sera, one showed a 4-fold increase of HI titer. Nasopharyngeal aspirates
therefore showed lower sensitivity than throat swabs at this test, different from
EIA test kits such as Directigen FluA or FLU OIA. Overall, only 5 specimens were
false positive by the ZstatFlu test. Therefore, this test demonstrated high
specificity and positive predictive value. In conclusion, the ZstatFlu test is
useful for the rapid detection of influenza A and B viruses to identify patients
who need antiviral treatment.
PMID- 10695290
TI - [The efficacy of influenza vaccine among geriatric inpatients].
AB - To investigate the efficacy of influenza vaccine in the elderly, hemagglutination
inhibition (HI) antibody titer for the three types of influenza viruses were
measured and the influenza infection rate was determined serologically in
geriatric inpatients. Influenza vaccination was done for inpatients. For patients
who had influenza vaccination in the year prior to the study, influenza vaccine
was administered once or twice, and the number of injections were determined
randomly. Influenza vaccine was injected twice to those had not received
influenza vaccine in the previous year. Serum samples were collected from 166
vaccinated and 104 unvaccinated patients before and after 1996/1997 influenza
season. In the vaccinees who had been vaccinated the previous year, 56 patients
were injected once and 58 patient were injected twice. Fifty-two patients had not
been vaccinated the previous year. Serologically diagnosed influenza infection
rate in the 104 unvaccinated patients was 16.3% for influenza A/H3N2 and 8.7% for
influenza B. The infection rate was 3.0% for influenza A/H3N2 and 0.6% for
influenza B in the 166 vaccinated patients. The infection rates were
significantly lower in the vaccinees than in the unvaccinated patients (p < 0.001
with A/H3N2 and p < 0.01 with B). There was no significant difference in the
infection rate among the three vaccinated groups. These results suggest that the
influenza vaccination had significant protective efficacy for influenza infection
in the elderly. Prior vaccination did not diminish the efficacy of the influenza
vaccine. The efficacy of a single influenza vaccine injection was equivalent to
that of two injection.
PMID- 10695291
TI - [Extended-spectrum beta-lactamase (ESBL) produced by Escherichia coli and
Klebsiella pneumoniae isolated from Teikyo University Hospital--the second
report].
AB - We studied the high-level resistant to cefotaxime (CTX, MIC > or = 512
micrograms/ml) clinical isolates of Escherichia coli and Klebsiella pneumoniae in
Teikyo University Hospital. The CTX-resistance could be transferred to E. coli K
12 chi 1037 or ML4903 strains from 30 of the 33 isolates by conjugation at a
frequency of 10(-4). When the hydrolysis rate of benzylpenicillin was 100%, the
beta-lactamases which were extracted from the transconjugants hydrolyzed CTX, CAZ
and AZT at the rate of 38-95%, 0-8.6% and 0-56%, respectively. These results
demonstrate that these enzymes should be categorized into ESBL. The nucleotide
sequence of CTX-resistant gene was identified to that of the CTX-M2 gene which
was first described in Argentina. It was found to have 99.9% homology to Toho-1
gene in Japan and 99.6% homology to CMY-2 gene. Using a PCR methods for the
detection of one of ESBL gene such as CTX-M2, Toho-1 or CMY-2, the DNA was
amplified from all strains (11 isolates of E. coli and 21 isolates of K.
pneumoniae).
PMID- 10695292
TI - [Antibody induction and frequency of adverse reactions to influenza vaccines in
the elderly].
AB - A total of 1,223 elderly people in nursing homes in Niigata Prefecture, Japan,
were immunized with one or two doses of commercial trivalent split vaccine
formulation, against strains including A/HN, A/H3N2 and B for three seasons (1996
1999). The frequencies of adverse reactions and antibody induction were assessed.
Frequent side effects of vaccination were local reactions such as redness and
tenderness at the site of injection, but there were no serious reactions,
suggesting that the vaccine was quite safe for the elderly. Furthermore, antibody
induction by immunization was relatively high and independent of the degree of
activities of daily living (ADL). Annual repeated influenza vaccination did not
diminish protection against influenza. However, antibody induction against
antigens was insufficient in the 1997/1998 season, and further improvement in the
combination of quantities of the four included antigens may by required. A
booster dose after the first dose did not enhance immune responses in the nursing
staff, and the one dose method appeared to be indicated for the elderly.
PMID- 10695293
TI - [Serovar distributions of cervical Chlamydia trachomatis isolated in Nagano
Prefecture].
AB - Between 1992 and 1998, serotyping of 82 Chlamydia trachomatis cervical isolates
were examined by micro-IF method in Nagano Prefecture. Of these, 17 isolates
(20.7%) were serovar E, 15 (18.3%) were serovar F, 14 (17.1%) were serovar D and
10 (12.2%) were serovar G, and the isolates typed these serovars were found to be
68.3% whole. Furthermore, serovars B (7.3%) and K (9.8%) were comparatively
frequently found. From 1992 to 1994, the number of isolates of B-complex,
intermediate and C-complex were 18, 17 and 6, respectively. On the other hand,
from 1995 to 1998, the number of the isolates were 19, 8 and 14, respectively.
The distribution of serovars of C. trachomatis tended to fluctuate from serovars
D and E to F and G as the patients grew older. Moreover, serovar E isolates were
only detected from patients less than 40 years old. Although most of the serovar
I isolates were detected from the patients with vaginal discharge, the other
isolates did not clearly indicate the relationship of serovars and clinical
symptoms.
PMID- 10695294
TI - [Clinical analysis of community-acquired pneumonia requiring hospitalization in a
community hospital--comparison of elderly and non-elderly patients].
AB - A comparative study of 890 patients with community-acquired pneumonia requiring
hospitalization in a community hospital was performed. The patients were divided
into an elderly patient group and a non-elderly patient group. The elderly
patients with community-acquired pneumonia exhibited frequent atypical symptoms
such as dyspnea, consciousness disturbance and complication of shock, and also
were frequently in a poor nutritional condition. The causative microorganism was
isolated in 40.8% of the elderly patients and in 44.0% of the non-elderly
patients. Polymicrobial agents were detected frequently in the elderly patients.
Streptococcus pneumoniae (19.4%), MSSA (16.8%), Klebsiella pneumoniae (15.1%) and
Haemophilus influenzae (15.0%) were frequently isolated from the sputum of the
elderly patients, while Mycoplasma pneumoniae (25.2%), H. influenzae (15.0%), S.
pneumoniae (12.2%) and MSSA (10.2%) were frequently isolated from that of the non
elderly patients. Regarding treatment with antibiotics, therapy with a single
antibiotic therapy, such as cephem or carbapenem was carried out for the elderly
patients, while new quinolone or tetracycline was administered to the non-elderly
patients. Although the treatment with antibiotics was adequate according to the
guidelines of the American Thoracic Society, the prognosis was poor; i.e.) in the
elderly patients an efficacy rate of 74.3% and a mortality rate of 9.5%. In the
non-elderly patients, the prognosis was good; i.e.) an efficacy rate of 88.0% and
a mortality rate of 1.7%. These results suggest that the most important factors
affecting the prognosis were the general condition of elderly patients and delay
in an adequate diagnosis and treatment because of atypical clinical findings.
PMID- 10695295
TI - [A clinical investigation of infective endocarditis at a community hospital in
Japan].
AB - There have been few reports on the clinical features of infective endocarditis
(IE) in Japan. We clinically investigates 45 episodes (36 cases) of definite IE
that were experienced from January 1985 to March 1997 at a community hospital,
Okinawa Chubu Hospital, Okinawa, Japan. Regarding age, prior dental procedure,
causative organisms and sites of infection, analyses and comparison were
performed on a total of 94 episodes, by adding another 49 episodes of IE that
were experienced between 1977 and 1984 at our hospital. The mean age was 47 years
and majority of patients in the recent 12 years were older than 50 years of age.
Mortality of all 94 episodes was 20%, while that of recent 45 cases was 13%.
Eight % of all episodes had history of recent dental treatment but significance
of the finding remains unclear. Alpha streptococci were most common (33%) and
Staphylococcus aureus was the second most common organism (17%). Eleven % of all
episodes were culture-negative and there was a statistically significant
difference in the histories of prior antibiotic therapy between culture-negative
and culture-positive episodes. Regarding sites of infection, 27% of all episodes
involved mitral valves, while 24% involved aortic valves. Prosthetic valves were
involved in 12%. Ninety-eight % of the recent episodes had fever, 98% had cardiac
murmurs and 27% had characteristic mucocutaneous lesions. Heart failure was the
most common complication (27%) and half of the cases with prosthetic valve
infection had heart failure. Cerebral embolism was most frequently seen among the
major arterial embolic complications. Our results were similar to those which
were previously reported from other countries. We should have a high index of
suspicion for endocarditis whenever we see patients who present various clinical
manifestations and fever of which origin remains unclear. Willingness to obtain
blood culture before starting antibiotics is most important.
PMID- 10695296
TI - [Gastrointestinal diseases associated with HIV infection].
AB - A clinical studies were carried out on gastrointestinal diseases associated with
HIV infection. During the 6 years between January 1993 and December 1998, 71 HIV
infected cases visited to Yokohama Municipal Citizen's hospital, and 26 of them
developed gastrointestinal complications during the course of their illness. They
consisted of 24 males and 2 females, with the mean age of 44.7 years and the
medial value of 42.5 years. Of the 26 patients, 21 were Japanese, and the
remaining 5 were Southeast Asian. The mean CD4 count was 143/microliter and the
medial value was 32/microliter at the time of development of complications.
Gastrointestinal complications were esophageal candidiasis in 6 patients,
cytomegalovirus (CMV) gastritis and gastric Kaposi's sarcoma in 1 patient each,
amebiasis in 8 patients, infectious colitis in 11 patients, and asymptomatic
pathogen carriers in 3 patients. Esophageal and gastric complications were common
in patients with low count of CD4, and endoscopy was useful for diagnosis.
Amebiasis developed even in patients with normal CD4 and was common in males with
experience in homosexual contact. It seems that homosexual contact acquire not
only HIV infection but also Entamoeba histolytica through sexual contact.
Protozoan and acid-fast bacteria were detected at high rate in patients with
infectious colitis and asymptomatic pathogen carriers. Besides food-born
infections, imported infections were seen in foreign and Japanese patients who
had traveled abroad. The gastrointestinal diseases associated with HIV infections
for the most part were opportunistic infections or tumors but imported, food
born, and sexually transmitted infections were also observed. It seems necessary
to take into consideration of varying background of patients in the treatment of
gastrointestinal diseases associated with HIV infections.
PMID- 10695297
TI - [Geographic distribution of Mycobacterium avium-intracellulare complex serovars
isolated from patients in five cities of Japan].
AB - Mycobacterium avium-intracellulare complex (MAC), isolated from patients with MAC
infection in five cities in Japan, was classified into M. avium and M.
intracellulare by DNA-DNA hybridization assay (DDH). They were also classified
into serovars by seroagglutination test and thin-layer chromatography (TLC)
detecting serovar-specific antigens. The ratios of M. avium: intracellulare
isolated in Sendai, Maebashi, Kobe, Hamamatsu, and Kumamoto, were 100:0, 26:16,
37:12, 37:39, and 17:54, respectively. It was high in the northern city, Sendai,
whereas the ratio in the southern city, Kumamoto, was low. The main serovars
detected in Sendai and Maebashi were 8 and 4. Various serovars including a new
type of M. intracellulare were detected with main serovars 16 and 7 in Kumamoto.
M. intracellulare including main serovar 16, and M. avium including main serovar
4, were detected in the same ratio in Hamamatsu. M. avium including main serovars
8 and 4, was detected in considerable high ratio in Kobe. Geographic distribution
was observed in both species of MAC and serovars.
PMID- 10695298
TI - [Flowcytomeric analysis on neutrophil intracellular enzyme activity in patients
on hemodialysis and continuous ambulatory peritoneal dialysis].
AB - To elucidate the mechanism of neutrophil dysfunction in patients with maintenance
hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD),
intracellular enzyme activity such as oxidative burst, elastase, cathepsin, and
collagenase, was investigated. Response of enzyme activity to in vitro addition
of TNF-alpha, which is known to have a powerful priming effect on neutrophils,
was also evaluated. Peripheral blood from 15 HD and 15 CAPD patients was washed
and incubated with Cell Probe, an indicator for intracellular enzyme activity.
Mean fluorescent intensity of neutrophils, which represents neutrophil enzyme
activity, was measured by flowcytometry. In HD group, unstimulated enzyme
activity was similar to that of control, but activity after addition of TNF-alpha
was significantly lower than the control. In the group of CAPD, enzyme activity
without stimulation was not different from that of control, and in TNF-alpha
stimulated neutrophils, only elastase activity was lower than control. Many of
the enzyme activities after stimulation were lower in HD than in CAPD. Response
to in vitro addition of TNF-alpha was diminished in both dialysis groups, but
more prominent in HD neutrophils. Duration of dialysis, serum concentration of
beta 2-microglobulin (beta 2-MG) and parathyroid hormone (PTH) was significantly
related inversely to intracellular enzyme activity in HD patients. To the
contrary, in CAPD group, although beta 2-MG and PTH showed similar negative
correlation, duration of dialysis was not related to enzyme activity. These
results indicate that neutrophils in patients with maintenance dialysis have
diminished intracellular oxidative burst, elastase, and cathepsin activity.
Especially, impaired response to TNF-alpha closely related to neutrophil
dysfunction in dialysis patients.
PMID- 10695299
TI - [Studies on centrifuge-concentration method of pooled samples for HIV screening
test by RT-PCR].
PMID- 10695300
TI - Specialists and the current medical "system".
PMID- 10695301
TI - The evils in the forest primeval.
PMID- 10695302
TI - Family medicine, generalist medicine, specialist medicine and the conduct of the
consultive relationship.
PMID- 10695303
TI - Primary care: the backbone of prevention.
PMID- 10695304
TI - Reflections from the field.
PMID- 10695305
TI - A day with Dr. Malaprop (or) on burning your bridges at both ends.
PMID- 10695306
TI - Some thoughts on the treatment of psychiatric disorders in the primary care
setting.
PMID- 10695307
TI - Obstetrics in family practice.
PMID- 10695308
TI - Rhode Island's Cardiac Services Registry.
PMID- 10695309
TI - Tobacco control report card: Rhode Island, 1999.
PMID- 10695310
TI - Improved access for patients or health care fraud? Hospital provision of office
space to physicians.
PMID- 10695311
TI - Education and science: similarities and differences.
PMID- 10695312
TI - Indoor environment and asthma.
PMID- 10695314
TI - Environmental air pollution and lung disease in children.
AB - Acute exposure to air pollution is associated with increased respiratory symptoms
and decreases in lung function in children. Respiratory symptoms in healthy
children are usually nonspecific and not severe. Lower respiratory symptoms and
extra use of bronchodilators will increase by about one-third with exposure to
peak levels of ozone in children with asthma. Similarly, sulphates will increase
the use of medication and decrease lung function in asthmatic children. Hospital
and outpatient admissions for children with pre-existing asthma may be increased
in the range of 20% with acute exposure to ambient ozone peaks and possibly with
increased sulphur dioxide (SO2). Short-term nitrogen dioxide (NO2) exposure from
indoor and outdoor sources has been associated with nonspecific respiratory
symptoms and decreased lung function, again particularly in children with pre
existing asthma. No effect on hospital admissions has been documented. Chronic
exposure to respirable particles, SO2 and NO2 is associated with up to three-fold
increases in nonspecific chronic respiratory symptoms. Exposure to high traffic
flow and, in particular, truck traffic and diesel exhaust leads to significant
increases in respiratory symptoms and decreases in lung function, while no clear
effect on the inception of asthma has been documented. It appears unlikely that
long-term exposure to pollutants or irritants is responsible for the increase in
asthma and allergy observed in many countries. However, although the effect of
air pollution is small in most children, it has a significant influence on the
health of children with pre-existing lung disease. Owing to the large number of
individuals exposed this results in a considerable burden for the health system.
PMID- 10695313
TI - Outdoor air pollution in urban areas and allergic respiratory diseases.
AB - Respiratory allergic diseases (rhinitis, rhinosinusitis, bronchial asthma and its
equivalents) appear to be increasing in most countries, and subjects living in
urban and industrialized areas are more likely to experience respiratory allergic
symptoms than those living in rural areas. This increase has been linked, among
various factors, to air pollution, which is now an important public health
hazard. Laboratory studies confirm the epidemiological evidence that inhalation
of some pollutants, either individually or in combination, adversely affect lung
function in asthmatics. The most abundant air pollutants in urban areas with high
levels of vehicle traffic are respirable particulate matter, nitrogen dioxide and
ozone. While nitrogen dioxide does not exert consistent effects on lung function,
ozone, respirable particulate matter and allergens impair lung function and lead
to increased airway responsiveness and bronchial obstruction in predisposed
subjects. However, besides acting as irritants, airborne pollutants can modulate
the allergenicity of antigens carried by airborne particles. By attaching to the
surface of pollen grains and of plant-derived paucimicronic particles, pollutants
can modify the morphology of these antigen-carrying agents and after their
allergenic potential. In addition, by inducing airway inflammation, which
increases airway epithelial permeability, pollutants overcome the mucosal barrier
and so facilitate the allergen-induced inflammatory responses. Moreover, air
pollutants such as diesel exhaust emissions are thought to modulate the immune
response by increasing immunoglobulin E synthesis, thus facilitating allergic
sensitization in atopic subjects and the subsequent development of clinical
respiratory symptoms.
PMID- 10695315
TI - Environmental lung disease: the role of diet.
PMID- 10695316
TI - Tobacco withdrawal symptoms and treatment.
PMID- 10695317
TI - Smoking cessation: nicotine replacement, gums and patches.
AB - This is an overview of smoking cessation with a clinical approach. The different
nicotine replacement products approximately double the long-term success rate
with a dose-response effect, but with an equal efficacy of the different
administration forms, so there is no long-term effect of a combination of two
products, and they have only mild side-effects. The success rate will increase
with the level of adjunctive behavioural support. Total smoking abstinence during
the first week after quit-day is a very strong predictor of long-term success.
Bupropion, an antidepressant drug, seems to be a promising drug in smoking
cessation and is at least equally efficacious as nicotine products. All health
care workers in pulmonary units have an obligation to deliver up-to-date smoking
cessation services to their smoking patients.
PMID- 10695318
TI - The psychology of tobacco addiction: why it is difficult to stop smoking.
PMID- 10695319
TI - The ELITE system.
AB - This report describes the technical limitations that affect the computation of
thoraco-abdominal volume displacement and the characteristics that an ideal
system should have. The elaboratore di immagini televisive (ELITE) system
satisfies many of these characteristics. ELITE system is an optoelectronic device
able to track the three-dimensional co-ordinates of a number of reflecting
markers placed noninvasively on the skin of the subject. The simultaneous
acquisition of kinematic signals with pleural and gastric pressures during a
relaxation manoeuvre allows the representation of pressure-volume plots
describing the mechanical characteristics of each compartment. The results of
studies concerning chest-wall mechanics by applying the ELITE system are
described.
PMID- 10695320
TI - Negative expiratory pressure method for the detection of expiratory flow
limitation.
PMID- 10695321
TI - Lung transplantation for emphysema.
PMID- 10695322
TI - Pulmonary rehabilitation in patients with severe chronic obstructive pulmonary
disease.
PMID- 10695323
TI - Terminology and testing of respiratory muscle dysfunction.
PMID- 10695324
TI - Respiratory muscles in internal medicine.
AB - This review provides evidence that respiratory muscle abnormalities are present
in many illnesses of internal medicine and emphasizes that clinicians should look
for respiratory muscle weakness in many circumstances, particularly immunological
disorders. Controversial results in hormonal diseases, metabolic diseases and
abdominal disorders indicate areas for further research.
PMID- 10695325
TI - Effects of surgery on the function of the respiratory muscles.
AB - The function of the respiratory muscles (RM) is affected positively or negatively
by a variety of surgical procedures. Cardiac, thoracic and upper abdominal
surgery impair the RM function and lead to postoperative complications such as
hypoxia, atelectasis, aspiration and infections. Preoperative assessment of RM
function is cardinal to avoid or attenuate these complications. Three types of
surgical procedures, lung transplantation, lung volume reduction surgery and
surgery for obesity have been shown to improve RM function. A mechanism by which
these types of operation have shown beneficial effects on RM function is
multifactorial, depending on geometrical factors, from the reduction of
hyperinflation and those depending on changes on the control of breathing.
Physicians dealing with postoperative care of patients should be aware of the
pathophysiological mechanisms that impair or improve respiratory muscle function
as a result of a surgery as well as of the therapeutic modalities.
PMID- 10695326
TI - Respiratory muscles in intensive care medicine.
PMID- 10695327
TI - Structural cells and extracellular matrix in chronic airways inflammation.
PMID- 10695328
TI - Are asthma and chronic bronchitis different diseases? Pro.
PMID- 10695329
TI - Are asthma and chronic obstructive pulmonary disease different diseases?--Con.
PMID- 10695330
TI - [Endoscopic endonasal surgery with image-guidance].
AB - We evaluated the advantages and disadvantages of image-guided endoscopic
endonasal surgery for various diseases. Thirty-three patients, including 8 with
chronic sinusitis, 14 with paranasal cysts, 1 with paranasal tumor (biopsy), 1
with sellaturcial cyst (Rathke's cleft cyst) and 9 with pituitary tumors were
endonasally operated on from September 1998 to May 1999, with an electromagnetic
navigation system, The Insta Trak (Visualization Technology Inc. USA). The Insta
Trak system is composed of a computer, a metal probe with a nonmetallic suction
tube attachment, and a soft-type headset with an electromagnetic sensor. This
freehand, armless system compensates well for patient's head movement during
surgery, and precludes the need for head fixation. Either straight or curved
suction tube (probe) can be used to access almost of all pathological sites in
the sinus cavity. Location of the metal probe is displayed on the computer
moniter as an intersection point on the axial, coronal and sagital CT images. In
all cases, Insta Trak showed the surgeon the appropriate location and direction
of each lesion. The Insta Trak also indicated the location of the orbit, optic
canal, nasolacrimal duct and/or skull base, thus, preventing intraoperative
complications. When the anatomy was distorted by previous surgery and/or when
there was uncontrollable bleeding from a severe lesion so that the surgeon had
difficulty finding the proper orientation, the usefulness of image-guided surgery
was sufficiently recognized. However, the following disadvantages were also
pointed out. An additional 15 to 20 minutes is needed for equipment set up and
operation, unless the surgeon and the operation room staff are familiar with the
machine. The patient's CT image used for navigation relies on data obtained
preoperatively, that is to say, it can not reflect morphological changes produced
during surgery. Moreover, the surgeon must consider possible errors of the
navigational point that may result in the headset during surgery, as well as,
errors the machine may originally possess. The image-guided system successfully
integrated the most up-to-date computer technology with a surgeon's anatomical
knowledge for improved treatment of endoscopic endonasal surgery. However, we
also concluded that the system should be used as a surgical supporting device for
safer and more adequate procedures.
PMID- 10695331
TI - [Management of the acoustic tumor in an only/better hearing ear].
AB - Because profound bilateral hearing impairment is a catastrophic event, the
management and care of an individual with an 8th nerve lesion in an only/better
hearing ear remains a significant challenge for both patient and physician.
Current options regarding the treatment of the acoustic tumor in an only/better
hearing ear include: observation, attempted hearing preservation surgery and
stereotactically guided radiation therapy. In this article, we present 3 cases of
acoustic tumor within the internal auditory canal in an only/better hearing ear
diagnosed by gadolinium-enhanced MRI and discuss the recommendations, especially
observation, available in the care of these cases. In one patient, hearing
disturbance caused by the tumor in a better hearing ear made the patient quite
depressive and desperate. One of the most important consideration is for the
physician to provide the patient with adequate informed consent regarding the
possibility of profound bilateral hearing loss caused by either the natural
growth or surgical removal of the tumor in the future, and alternative methods of
communication with others such as: hearing aid and lip reading, cochlear implant
and brainstem implant.
PMID- 10695332
TI - [Ultrasonographic screening for thyroid cancer in the screening].
AB - In our hospital, ultrasonography is performed for patients who come for thyroid
cancer screening. Seventy-eight patients with thyroid cancer which was found by
such screening were operated on from 1989 to 1998, while 287 patients with
thyroid cancer found by other methods were operated on during the same period in
our department. The age of the patients at surgery in the screening group was
younger than that of the contrast group. In the screening group, 41 (52.6%)
patients had small thyroid cancer, a higher rate that in the contrast group.
Invasion of surrounding organs by the primary cancer was observed in only one
patient (1.3%) in the screening group, a rate of invasion that was statistically
lower than that in the contrast group. Twenty-six patients with benign thyroid
disease detected in our screening were operated on during the same period.
Careful selection of patients who need fine-needle aspiration cytology is
demanded of head and neck surgeons, and careful evaluation of indicators is
necessary to avoid surgery in the case of benign thyroid disease.
PMID- 10695333
TI - [Identification of bacterial strain at each episode of recurrent acute otitis
media].
AB - This study was undertaken to investigate whether each episode of recurrent acute
otitis media (rAOM) is caused by the same strain of bacteria or different strains
at each episode. Seventy infants less than 3-years of age, having experienced
rAOM for a period shorter than 8 weeks, were selected and included in the present
study. The total number of AOM episodes experienced by this group was 282. At
each subsequent episode of AOM, otorrhea and nasopharyngeal swabs were taken for
bacterial culture and determination of the MIC for antibiotics. When S.
pneumoniae was identified, its serotype, and its pbp, ermAM, and mefE genes were
also investigated to determine the bacterial species and strains. S. pneumoniae
was the most frequently cultured bacteria with 26 penicillin-sensitive S.
pneumoniae (PSSP), 65 penicillin-insensitive S. pneumoniae (PISP), and 50
penicillin-resistant S. pneumoniae (PRSP). H. influenzae was the next most
frequently cultured bacteria of which 65 were sensitive to penicillin, 27 were
found to be beta-bactamase-negative-ampicillin-resistant (BLNAR) and 17 were
found to be beta-bactamase positive. Bacteria cultured from each pair of two
successive episodes of AOM were compared as to the identity of the bacteria
during the two episodes. In 150 out of 202 pairs (74%), the cultured pathogen was
different. In 22 cases in which either PISP or PRSP was the pathogen detected in
two consecutive AOM episodes, 15 cases (68%) were found in which the involved
strain differed between the two episodes. This study indicates that the pathogen
involved in rAOM is likely to differ at each episode of AOM, not only in cases
caused by PSSP, but also in those caused by PRSP.
PMID- 10695334
TI - [Pharyngeal foreign bodies in infants persisting for two months: two case
reports].
AB - In general, patients who suffer from pharyngeal foreign bodies can explain the
time and nature of the object which had been swallowed, resulting in easy
diagnosis. However, in infants, difficulty in communication makes diagnosis
troublesome. Two cases of long-standing pharyngeal foreign bodies were treated at
our hospital. Case 1 was a 16-month-old girl complaining of stridor and fever.
She had fallen with a toothbrush in her mouth two months before, and was
hospitalized in the pediatrics department for one week with upper airway
inflammation and dehydration. A toothbrush head was embedded in the back wall of
the mesopharynx and hypopharynx. Case 2 was a 10-month-old boy complaining of
dysphagia and failure in weight gain. He was hospitalized in the pediatrics
department with pneumonia two months before. A PTP (press through pack for
medicine) was embedded in the back wall of the hypopharynx. We removed both
foreign bodies under general anesthesia.
PMID- 10695335
TI - [Snacking behavior among elementary and junior high school students and its
relationship to stress-coping].
AB - The aim of the present study was to investigate current problems of snacking
behavior and their relationship to stress coping among 1,486 fourth through ninth
grade students from 10 elementary schools and six junior high schools. An
anonymous self-completed questionnaire was utilized which included items about 1)
selection of snack foods, which were classified into healthy, popular,
complementary and western-style snacks, 2) problems of snacking behavior, which
included external and emotional eating scores, and 3) stress coping scale. The
stress coping scale contained two sub-scales; problem-focused and emotion-focused
coping. The results were as follows: 1) Students who frequently went without
breakfast did not select healthy foods, i.e., fruits and dairy products, but
popular snacks, i.e., potato chips, pop corn and sweet beverage. 2) Both external
and emotional eating scores increased by age in girls but was not apparent in
boys. 3) Students who preferred either western-style or popular snacks showed
higher score of external and emotional eating. 4) The score of problem-focused
coping was positively correlated with preference for health snacks, but emotion
focused coping was positively correlated with external and emotional eating
scores. The close relationship between snack food selection and problematic
aspects of eating behavior suggests that modification of eating behavior is
necessary to develop healthy snack habits in early adolescents. Also, it is
interesting that snacking behavior is closely related to stress coping, which
suggested the behavioral intervention for healthy eating habit should be included
in development of stress-coping skills against various kinds of demands in life.
PMID- 10695336
TI - [A field study of health effects of aircraft noise in adults around Komatsu Air
Base (1998)].
AB - OBJECTIVE: To ascertain the effects of aircraft noise on complaints about life
disturbances and on psychological and physical symptoms in adults around Komatsu
air base. METHODS: From April to June 1998, a questionnaire was answered by 203
persons (from 89.8% of families) in 2 areas without aircraft noise, and by 412
persons (from 89.0% of families) in 5 areas with a weighted equivalent continuous
perceived noise level (WECPNL) of 75 or more. The questionnaire covered age,
gender, work location, noise exposure time, past experience with noisy work and
ear disease, complaints about noisiness and life disturbances, and psychological
and physical symptoms. Multivariate linear models by JMP (SAS institute Inc.)
were applied to analyze the relationships between the above factors including
noise level and complaints or symptoms. RESULTS: Subjects in the areas with noise
had more complaints about noisiness than 5 years before, although replies were
less in areas without noise. Subjects in areas with a WECPNL of 75 or more had
more complaints and symptoms than those in areas without noise. Moreover,
subjects experiencing higher noise levels gave higher responses for most of
complaints and symptoms. The JMP linear models showed that aircraft noise was
positively related to complaints and symptoms after taking the effects of age,
gender and past experience with noisy work and ear disease into consideration.
Higher noise levels and longer exposure times were related more strongly to most
complaints and symptoms. CONCLUSION: This study shows that aircraft noise with a
WECPNL of 75 or more is related to various complaints and psychological and
physical symptoms in adults around Komatsu air base, after considering the
effects of age, gender and past experience with noisy work and ear disease. It
also shows that higher noise levels and longer exposure times are related more
strongly to many complaints and symptoms. The results also suggest that responses
to aircraft noise have become more severe than in the past.
PMID- 10695337
TI - [Psychiatric distress and related risk factors of family caregivers who care for
the demented elderly at home].
AB - The objectives of our study were to assess psychiatric distress of caregivers who
had been caring for the demented elderly at home and to examine the association
of caregivers' psychiatric distress with putative risk factors. Subjects were 294
caregivers living in Amakusa, Kumamoto Prefecture of Japan, whose spouses,
parents or other family members were registered at Amakusa Public Health Center
as demented elderly. In 1998, Survey on Caregivers' Mental Health was conducted
using the General Health Questionnaire (GHQ12) as a measurement for general
psychiatric state of caregivers. Two hundred and eighty-two caregivers responded
to interviews with complaints of the following psychological symptoms: feelings
of unhappiness (55.7%), of stress (41.8%), insomnia (29.4%) and depressed mood
(29.1%). Seventy-six caregivers (27.2%) were identified as being above the cut
off point 4 for psychiatric distress caseness. Multivariate logistic regression
analysis indicated caregivers' psychiatric distress was statistically associated
with caregivers' age, the caregivers' perception of the severity of dementia, the
number of years devoted to caregiving at home and perceived financial state.
Being 50 to 69 years (OR = 0.37, 95% CI: 0.17-0.81) and being 70 years or older
(OR = 0.35, 95% CI: 0.14-0.83) were negatively associated with caseness as
compared to being 20 to 49 years. Caseness was positively related to the severity
of the elderly's demented state (OR = 6.93, 95% CI: 1.99-24.19), 1 year to 2
years devoted to caregiving at home (OR = 3.26, 95% CI: 1.02-10.38), no family or
social support (OR = 2.99, 95% CI: 1.12-7.96) and lower perceived financial state
(always OR = 6.99, 95% CI: 2.77-17.64, sometimes OR = 2.41, 95% CI: 1.19-4.85).
Reduction of caregivers' psychiatric distress is important for not merely the
enhancement of quality of care for demented elders and caregivers' life but for
the prevention of elder abuse or neglect. Our study suggests that a comprehensive
assessment and intervention program is needed for the demented elderly and their
caregivers, in order for caregivers to be able to adapt well to the challenges of
caregiving and find personal meaning through caregiving.
PMID- 10695338
TI - [Evaluation of the operation of supporting programs for social activity of the
elderly by city, town, village governments in Japan].
AB - OBJECTIVES: The aim of this study is to clarify the operative situation of the
supporting programs for social activity of the elderly by city, town, village
governments in 1997. METHODS: We conducted a study of 3,255 of cities, towns and
villages in Japan using a mailed questionnaire, which had been developed to
assess the activities of supporting programs for social activity of the elderly.
The questionnaire asks government officers whether they had each of the 33
programs in 1997. Each one of these programs belongs to one of the four different
aspects of social activities: 1. employment, 2. social
participation/volunteering, 3. education/training, 4. individual activities. For
each program, the frequency of regions having the program were counted in total,
as well as for each of four levels on governments scale: 1. ordinance-designated
city, 2. city, 3. town, 4. village. The number of programs operated by the
municipality were also evaluated. The main results were as follows One thousand
six hundred (49.2%) of cities, towns and villages responded to our questionnaire.
1. Four programs, the promotion of clubs for elderly people, class/lecture
meetings for the elderly, sporting events/athletic meetings for the elderly, and
a respect-for-age congratulatory gift/money, were put into operation by over 80%
of cities, towns and village governments. 2. The number of programs in total or
for each of the three aspects of social activities except for social
participation/volunteering tended to be high for the large scale governments.
There were wide gaps in the number of programs among the regions even of the same
level of the government scale. 3. The regions having supporting programs for
employment consisted mainly of cities. Seventy-five percent of villages had no
supporting program for employment. CONCLUSION: The operational situation of the
supporting programs for social activity of the elderly by city, town, village
governments was clarified. Furthermore, results obtained by this study can be
used for self-assessment of operational situations by municipalities and can
contribute to the activation of their supporting programs.
PMID- 10695339
TI - [Outbreak-like tuberculosis cases in a general clinic with beds].
PMID- 10695340
TI - [Work load analysis for oral care in special nursing homes].
AB - The work load analysis for oral care in special nursing homes. Dental hygienists
undertook oral care of 100 person who were confined to special nursing homes in
Aichi prefecture, Japan. The time required, the physical load, the psychological
burden were analysed. The results were summarized as follows; 1) Oral care by
dental hygienist was incorporated as one of the 59 care tasks given in special
nursing. 2) The working time for required oral care was 25.7 minutes per resident
on an average. 3) In general, speaking to the elderly, recording on an assessment
card, and observing conditions were undertaken most frequently. In oral care,
tooth cleaning, gargling, cleaning of dentures, wiping of the mouth and advising
those caring for the elderly, was performed most frequently. 4) In general, time
taken for advising those caring for the elderly, report to the home dentistry,
advising the elderly, recording, and evaluation was most common. In oral care by
a dental hygienist, tooth cleaning, cleaning of the dentures, cleaning the mouth,
gargling, prevention of dryness of the mouth were performed most frequently. 5)
In physical activity, raising the person, moving him from the wheelchair to the
bed and helping him to lie down were most frequent. In oral care by a dental
hygienist, wiping the mouth, inserting dentures, tooth cleaning, cleaning the
mouth and removing dentures were most common. 6) The psychological burden when
lifting the person, moving him from the bed to the wheelchair and helping him to
lie down was the greatest. In burden involving oral care by a dental hygienist,
tooth cleaning, removing dentures, inserting dentures and cleaning the mouth were
the greatest.
PMID- 10695341
TI - [A survey on drug-related service by homehelper in the Japanese home care
system].
AB - The purposes of this study are a) to determine whether homehelpers attend to drug
related service of elder care-recipients at home and b) to determine what
cooperating human resources were utilized. A structured questionnaire survey was
conducted in 1997 with 403 homehelpers who provided in home care to dependent
elderly person. Of the total, 19% subjects did deal with care recipients'
medication. Regarding the type of service, the highest proportion of subjects had
assisted by picking up medicine from pharmacy and talking it to the care
recipients' home. Results showed that physicians and home visiting nurses were
the most depended upon human resources in the home health care system among
health, medical and welfare facilities. Results also suggested that many
homehelpers are not aware that pharmacists are readily available resources for
providing home health care. Hence we conclude that the respondents tend to rely
on physicians or home visiting nurses to respond to care recipients care, and
pharmacists should be made aware of the necessity of providing the appropriate
drug-related information to physicians or home visiting nurses.
PMID- 10695342
TI - [Obesity and life style of Japanese school children with Down syndrome].
AB - A questionnaire-based investigation was performed on 325 Japanese school children
with Down syndrome ages 6 to 18. Data on height and body weight, eating habits,
physical activity for these children were obtained through their parents.
Proportion of obese children was higher among these subjects than the average for
Japanese children (34.3% and 7.47% respectively, for the ages from 6 to 14). We
examined characteristics of eating habits and physical activities between the
obese group (obesity index greater than 20% above the average of Japanese school
children) and the non-obese group. Obesity started to increase in the obese group
around age 7. The obese group tended to have had a greater intake of sweets,
juice and total foods in their preschool days, but unexpectedly had been
physically more active in their primary school days.
PMID- 10695343
TI - [Current view of macrophage recognition/immune response system to
microorganisms].
PMID- 10695344
TI - [Mycoplasmal membrane-bound lipoproteins capable of activating macrophages or
fibroblasts to induce cytokine production].
PMID- 10695345
TI - [Molecular epidemiology--molecular typing of pathogenic bacteria using pulsed
field gel electrophoresis].
PMID- 10695346
TI - [Molecular epidemiology of enterohemorrhagic Escherichia coli].
PMID- 10695347
TI - [Bacterial intercellular communication and environmental adaptation].
PMID- 10695348
TI - [Ecology of Borrelia and molecular epidemiology of Lyme disease].
PMID- 10695349
TI - [Molecular epidemiology of diphtheria re-emerged in Russia].
PMID- 10695350
TI - [Acute pancreatitis: recent advances in understanding its pathophysiology].
AB - This article reviews the recent changes in the understanding of acute
pancreatitis pathophysiology emphasizing results deriving from the more detailed
comprehension of the local and systemic aspects of the inflammatory process. The
authors briefly discuss those theories that have been influencing the basic
philosophies of treatment efforts. The role of premature digestive enzyme
activation as the principal determinant of the pathoetiology and mortality of
this disease has been questioned lately, and the inflammatory explosion has been
placed into the center of attention. Simultaneously with the enzyme activation,
the pancreatitogenic noxious event rapidly induces the formation of oxygen
derived free radicals, activation of the transcription factor NF kappa-B, with
consequent citokine production, cellular adhesion molecule upregulation and
leukocyte hyperstimulation. Numerous other mediator cascades are activated in
parallel, the uncontrolled surge of proinflammatory stimuli, and activity of the
effector cells lead to multiple organ failure in severe cases. A genetically
determined catastrophe management program is set forth in the acinar cell with
pancreatitis associated protein expression and activation of the apoptosis
machinery. Therapeutic approaches based on these recent findings are briefly
touched upon.
PMID- 10695352
TI - [Acute appendicitis in a patient with increased lead absorption].
AB - The authors describe the case history of an acute appendicitis of a patient
suffering from increased lead resorption. The operation resulted in complete
healing. They draw the attention to the possibility of an acute abdominal disease
also in case of abdominal complaints of patients suffering from increased lead
resorption. Careful observation of the patient in collaboration with a surgeon is
necessary to avoid a dangerous diagnostic error.
PMID- 10695351
TI - [Experience with laparoscopic adrenalectomy in 25 cases].
AB - Between July 1997, and April 1999 the authors performed 25 transperitoneal
laparoscopic adrenalectomies. Conversion due to bleeding in 3 cases and due to
unsuspected malignancy in 1 case was necessary. Complete resection was carried
out in 22 cases. In 3 cases where a well circumscribed adenoma was visualized,
only enucleation was performed. A new approach for left sided resection was also
introduced. In the authors experience laparoscopy is an absolutely suitable
intervention for the benign diseases of the adrenal glands. It assures a short,
uncomplicated and painless postoperative period for the patients, with the same
effectivity and safety compared to the conventional method.
PMID- 10695353
TI - [Two familial cases of hereditary multiple exostoses].
AB - Hereditary multiple exostoses is an autosomal dominant disorder. Three different
chromosomal loci have been implicated in this genetically heterogeneous disease.
The authors describe a family in which 3 generations were affected, there were
data about the disease of an already died grandmother, the father and his
daughter were investigated by conventional X-ray and the disease was proved. The
disease caused only minor complaints. The exostosis of the father's pelvis showed
increased isotope uptake during bone scintigraphic examination, the same region
exhibited malignant degeneration on MR examination. Regular check-up of the
patients is necessary because of the possibility to a malignant transformation in
1-27% of the cases.
PMID- 10695354
TI - [The Cracow University].
PMID- 10695355
TI - [In memoriam Dr. Janos Veres, M.D].
PMID- 10695356
TI - [Intravenous injections of tartaric acid sublimate in streptococcus pyogenes and
staphylococcus aureus infections. 1899].
PMID- 10695357
TI - [Contribution to the paper "Depiction of the heart on Hungarian medical coins"].
PMID- 10695358
TI - [The clinical course of end stage heart disease in 152 patients qualified for
heart transplantation in a four year observation].
AB - The aim of the study was to analyse the clinical course of pts with end stage
disease (ESD) in the period of four years. The study population consisted of 152
pts (132 males, 20 females) at the age of 17-66 years (mean = 48.8 year SD = 9.1)
primarily qualified to the heart transplantation (HTX). We analysed the ethiology
of cardiac failure, the NYHA class of circulation insufficiency, frequency of
occurrence of cardiac arrhythmias and conduction system disturbances in 24-hour
ecg monitoring, and the pharmacotherapy efficacy. An ischemic ethiology of
cardiac failure we found in 102 pts, cardiomyopathy (idiopathic, hypertrophic or
postinfectious) in 46 and unoperable valvular disease--in 4. Ten pts were in II
NYHA class, 112 in III, and 30 in IV. Left ventricular ejection fraction (echo
assessed) ranged from 11% to 40%(mean = 24.9%), LVEDd = 46-111 mm (mean = 80.9
mm), LVESd = 34-83.5 mm(mean = 63 mm). We found IVa class by Lown ventricular
arrhythmias (in Holter monitoring) in 38 pts and IVb in 78. Fifty six pts were
treated with amiodarone, 10--with beta-blockers and 11 with sotalol. 19 pts were
treated by permanent cardiac pacing during the waiting period, 2 ones--by PTCA, 2
-by CABG, three ones--by dynamic cardiomyoplasty, and one--by partial
aneurysmectomy. One pt was treated by CABG and automatic cardioverter
defibrilator implantation. In 5 cases HTX was delayed because of the positive
effect of pharmacotherapy. In assessed period HTX were performed in 64 cases, 31
pts died and 43 are still waiting for the procedure. CONCLUSIONS: During the 4
year period HTX were performed in 42% of waiting pts. Mortality in this group was
38.2%. In 9 pts (5.9%) the alternative methods of surgical treatment were
applicable. In 5 pts (3.9) the decision about HTX was delayed because of the
positive change of the clinical status. This fact confirms the necessity of the
waiting list verification.
PMID- 10695359
TI - [Intracranial hemorrhage during anticoagulant and thrombolytic therapy].
AB - Intracranial hemorrhages are the most severe complication of nowadays widely used
anticoagulant and thrombolytic therapy. During 34 months we observed 102 cases of
intracranial hemorrhages at the Department of Neurology at our hospital. Among
them 8 cases occurred during anticoagulant and/or thrombolytic treatment. The
most common risk factors were: arterial hypertension, simultaneous use of other
drugs with possible interactions and not following the rules of safe therapy.
Because of the dangerous complications during this kind of therapy the risk
factors have to be considered.
PMID- 10695360
TI - [Modifications in treatment of tetanus and prognosis--observations from the
Cracow Department of Infectious Diseases].
AB - The assessment of modifications in the tetanus treatment, which included using
metronidazol and midazolam instead penicillin and diazepam, was presented.
According to our own observations and previous investigations, mentioned above
changes in the tetanus therapy improve survival rate, reduce psychiatric
disturbances and shorten hospitalisation time.
PMID- 10695361
TI - [The clinical value of B waves in the cerebrospinal fluid pressure curve during
the lumbar infusion test of patients with hydrocephalus].
AB - There are still many problems in the selection of hydrocephalic patients for the
shunt treatment. Many investigations focus to find out a new and reliable
prognostic factors including the parameters of lumbar infusion test (LIT). The
aim of this study is to evaluate the B waves observed during the LIT, and to
assess the prognostic value of the B waves in hydrocephalic patients. 153
patients with communicating hydrocephalus (ventricular index > or = 0.8) were
assessed by means of the LIT. B waves were detected in 70 patients (45.8%).
Primary assessment was verified by the Fourier analysis. The relationship was
analysed between B waves and the resistance to outflow (R), new steady state
pressure (Pns) and the standard deviation of the Pns (SDPns). The results of
treatment depending on the presence of B waves were assessed in 95 shunted
patients (two categories: improved/not improved). Statistical analysis was
performed using Statistically 5.1 for Windows. Chi square test, Mann Whitney U
test, and the Student T test were applied (p < 0.05). There was statistically
significant relationship between B waves and the increasing values of R (p =
0.0002), Pns (p = 0.0002) and SDPns (p = 0.0000). Positive prognostic value of
the B waves was found in the group of 95 shunted patients (p = 0.0152). 1. B
waves during LIT appear significantly more often in patients with increasing
compensation impairment. 2. B waves detected in LIT have a good prognostic value
in hydro-cephalic patients.
PMID- 10695362
TI - [[35 Years of effort to improve the diagnosis of porphyria].
AB - World history of porphyria is given in brief. The activities of Porphyria Center
during period of 25 years have shown how difficult it was to introduce diagnostic
measures for this rare and very little known group of diseases. The obstacles
encountered during the popularization of the knowledge of porphyria were: minimal
information on porphyria, very seldom seen in Poland, therefore rather negative
approach of the doctors to these patients,--almost never porphyria was seen in
differential diagnostics of abdominal pains or polyneuropathies, herefore
diagnosis, if made, was very late, often just before death. From the other side
insufficient support for doctors was given by laboratories because of the lack of
simple diagnostic tests. Along the 35 years of the work in the Institute of
Haematology and Transfusiology the situation was steadily improving but slowly
due to technical and economical difficulties. The Center was organized, now well
equipped and able to diagnose and differentiate all types of porphyrias. A
computerised basis of the collected material consist of 383 families (6000
persons registered). Among them there are nearly 600 acute (who have passed one
or more attacks of porphyria) and about 1000 latent cases of porphyria. The
mortality which was 52% in the first collected group of patients (1960-1970) has
fallen to less than 10% concerning very severe and late diagnosed attacks. In
1996-1998 there were only two deaths during attacks of porphyria in Poland.
PMID- 10695363
TI - [Some aspects of non-pharmacologic treatment of hypertension].
AB - Non-pharmacological methods of intervention are often used as individual or
complementary forms of antihypertensive therapy. The aim of the study was to
assess the level of compliance and acceptance of some life-style modifications in
patients with hypertension. 432 hypertensive patients participated in the study.
The study consisted of filling in anonymous questionnaires, taking blood
pressure, height and weight measurements. Different approaches of
nonpharmacological treatment of hypertension are accepted in differing degree.
Life-style modifications and blood pressure self-monitoring should be an integral
part of antihypertensive-treatment-programme.
PMID- 10695364
TI - [Infections with Chlamydia pneumoniae, Helicobacter pylori or cytomegalovirus and
atherosclerosis].
AB - It's known that common risk factors of atherosclerosis can explain only 50% of
its etiology. In only 40% patients risk factors modification inhibits progression
of atherosclerosis. Therefore looking for new risk factors of atherosclerosis is
necessary. In recent years the inflammatory-infectious hypothesis of
atherosclerosis has been reevaluated. The discovery of heavy infections load in
the serum of patients with acute coronary syndromes might suggest a potential
immunological mechanism triggered by bacterial proteins. Chlamydia pneumoniae,
Helicobacter pylori and cytomegalovirus infections are very common in human
population and therefore they are suspected as the main infectious pathogen in
the coronary disease. Clinical studies have demonstrated higher anti-Chlamydia
and ani-Helicobacter antibody titres in patients with myocardial infarction (60
70% pts), stable and unstable angina (50-60% pts) than in control groups (12-15%
pts). Two studies were performed with antibiotic (azotromycin, roxitromycin)
influence on the prevalence of acute coronary syndromes after myocardial
infarction and unstable angina. These studies have shown statistically
significant reduction of the prevalence of acute coronary episodes in follow-up
period.
PMID- 10695365
TI - [Endogenous mechanisms for protection in myocardium].
AB - New opinions about myocardial adaptation during ischaemia are described in
presented article. Myocardial preservation mechanisms in response to ischaemia
are divided into metabolic adaptation like preconditioning and hibernation and
anatomic mechanisms of adaptation like development of collateral circulation.
Adaptation in clinical conditions can be observed in few situations. 1) During
repeated in short period of time exercise tests (warm up). Adaptation may express
through increasing tolerated ischemic burden, lenghtening time of exercise,
increasing of ischaemic threshold and double product during successive exercise
tests (predominately second). This phenomenon called warm up is a clinical
counterpart of myocardial preconditioning. 2) In study during coronary
angioplasty demonstrated that decrease of ST-segment, intensity of thoracic pain
and serum lactacidaemia was lower during the second balloon inflation than the
first. 4) The example of myocardial adaptation is repeated atrial stimulation.
Ischaemic myocardium should be treated like some kind of mosaic of necrosis,
hibernation, stunning and normal viability.
PMID- 10695366
TI - [Calcium blockers and their their present application].
AB - Use of calcium channel blockers in arterial hypertension and other cardiovascular
diseases has increased substantially during the last decade. The biological role
of calcium in contractile tissues mechanisms of action of calcium channel
blockers and their present application are discussed.
PMID- 10695367
TI - [Dysfunction of platelets in uremia].
AB - Both bleeding and thrombosis may complicate the course of chronic uremia. The
main cause of bleeding diathesis is a dysfunction of the primary hemostasis. The
widespread improvement of conservative and substitutive therapy has considerably
ameliorated the frequency of hemorrhagic complications in uremic patients. The
aim of the study review modern views on pathogenesis of bleeding diathesis with
particular attention paid to the role of platelets, as well as diagnostic and
therapeutic possibilities.
PMID- 10695368
TI - [Cytokines in the pathogenesis of liver fibrosis].
AB - Cytokines are synthetized and secreted in the liver mostly by Kupffer cells and
play a key role in inflammatory processes and immunological response related to
liver diseases, which are initiated by hepatocytes damage. This type of
signalling between different types of liver cells, can produce contrary
reactions. For instance transforming growth factors beta as well as inetrleukins
1 beta, 4 and 6 induce fibrosis. In contrast, transforming growth factor alpha,
tumor necrosis factor alpha, interleukins 1 alpha and interferons are inhibitory
to fibrosis. Lost of the balance between these stimuli seems to be responsible
for activation of nonparenchymal cells, that result in accumulation of
extracellular matrix proteins (including collagens) with liver cirrhosis as a
clinical effect. Connections between cytokines, cells located in the liver and
diseases with hepatic fibrosis are reviewed in this article.
PMID- 10695369
TI - [Depression as a risk factor for cancer--is it still a hypothesis or a proven
fact?].
AB - The connection between depression and cancer has been described several times.
These observations have been made on major depression and on other kinds of
depression as well. It is possible that similar genetic defect may play an
important role in the development of cancer and major depression. Disturbances in
function of endocrine and immunological systems, which have been observed in
depression, can be the risk factor for cancer. Large epidemiological research
showed that in persons with depression increased risk of cancer diseases, but not
every research confirm it. Large disagreement of research results don't permit of
sure answer, but the hypothesis is still possible and require incessant research.
Development of research methods, particularly a new domain called molecular
epidemiology give hope for more precise future answer.
PMID- 10695370
TI - [Pneumothorax in cigarette smokers].
AB - From 1.01.1992 to 31.12.1998 ill prisoners were treated because of so called
spontaneous pneumothorax. Their age was between 24 to 57, which was 33 in
average. All of them were males and heavy smokers. In one case of the coat
pneumothorax the treatment was limited only to the breathing exercises, to ten
other patients an under-water-seal drainage was applied, in the next case with
pneumothorax and clear symptoms of bronchial fistula, the lung expansion was
obtained no sooner than after the usage of a suction drainage. The risk of
recurrence of the illness was limited by injection of 40% glucose solution
through the drain to the pleural cavity to increase adhesions.
PMID- 10695371
TI - [Pulmonary artery sling--diagnostic difficulties].
AB - The pulmonary artery sling is a very rare vascular anomaly which consists in
improper branching off and course of the left pulmonary artery. This artery
presses on the trachea causing significant symptoms on the part of the
respiratory system such as dyspnea, stridor or cyanosis. The authors present the
case of a 17-month-old boy who had dyspnea incidents for several times while the
reason was unknown. It was only after the X-ray examination of the chest with
barium in the esophagus was carried out alongside the bronchoscopy, followed by
the echocardigraphic and angiocardiographic examinations that the pulmonary
artery sling was found to be reason for those incidences.
PMID- 10695372
TI - [Bland-White-Garland syndrome co-existing with ventricular septal defect and
patent ductus arteriosus--diagnostic difficulties].
AB - A case of a 14 month-old boy suffering from unrecognized Bland-White-Garland
syndrome with no typical clinical and electrocardiological features was reported.
Diagnostic difficulties were caused by ventricular septal defect and patent
ductus arteriosus co-existing with the anomaly of left coronary artery. Death
caused by myocardial ischemia occurred after surgical closure of VSD and PDA.
PMID- 10695373
TI - Cybernetics and consciousness.
AB - This paper is a review of hypotheses of consciousness which arose from
application of the theory of information and regulation and the cybernetic theory
of mathematical machines in medicine. The author presents these hypotheses on the
examples of his own works.
PMID- 10695374
TI - [The understanding of disease in the second half of the XIX century and and the
beginning of the XX century and postulates of social medicine. Preliminary
study].
AB - Representatives of Polish school of the philosophy looked for the answers to the
questions: what the medicine should be and how to use the practice of treatment
as a tool of the medical knowledge acquirement? The answers to these questions
presented in books and in the journal "Krytyka Lekarska" have contributed to the
development of Polish medical thought. The tasks imposed on the social medicine,
which in the second half of the 19th century formulated new goals for the
medicine, got reflected in this thought too. Health and the endeavor to be free
from diseases were of primary importance in the theoretical postulates of the
social medicine. Achieving fitness, aiming at it, preserving and enhanding good
health were the basic objects of the requests addressed to doctors and medicine.
At the same time therapeutic methods offered were often ineffective because the
medical activity was focussed on diagnosing and understanding the nature of the
disease rather than its treatment.
PMID- 10695375
TI - [Scientific medical faculty at the Jagiellonian University from the the Silesian
region in 1919-1939].
AB - The article refers to the bonds of the Silesian medicine with the Faculty of
Medicine at the Jagiellonian University in interwar period. Fiftieth anniversary
of the Silesian Academy of Medicine occurring in 1998 is a chance to recall these
relationships. There is a special attention paid to graduates from the
Jagiellonian University coming from historical Silesian who graduated from the
University, who got doctor's certificates and University degrees. Some of them
stayed at the University taking over high ranks, others came back to Silesia,
where as high qualified physicians created medical personnel of manufacturing
industry of Silesia.
PMID- 10695376
TI - [Nonmyeloablative allogeneic hematopoietic stem cell transplantation:
minitransplantation].
AB - Allogeneic hematopoietic stem cell transplantation (alloHCT) is considered as a
treatment of choice for many malignant hematologic disorders and genetic
diseases. Unfortunately toxicities of conventional alloHCT remain a major
limitation to successful application of the procedure. A radically new approach
for alloHCT has been developed. Nonmyeloablative preparative regimen allows to
establish mixed hematopoietic chimerism after alloHCT. A state of stable mixed
chimerism may represent a starting point for induction of full donor derived
hematopoiesis. A published results of several clinical trials have confirmed
potential benefits of this new approach such as less procedure--related toxicity,
protection from severe acute GVHD (graft versus host disease), lower TRM
(transplant related mortality). Intensive investigations are done to replace in
the future pretransplant chemotherapy and/or radiation by nontoxic anti-T-cell
agents. These include antibody to the T-cell receptor alpha beta and blockers of
T-cell costimulation (e.g. CTLA4lg).
PMID- 10695377
TI - [Early results of treating pituitary adenomas by means of transcranial and trans
phenoidal approach].
AB - Among the methods of the surgical approach to the pituitary tumours,
transsphenoidal (TS) route replaced transcranial (TC) route in the majority of
patients. The authors present the development of the surgical treatment of
pituitary tumours, and present the early results of treatment by means of both
methods of surgery based on the experience of the Department of Neurosurgery in
Krakow. Consecutive 45 cases of pituitary adenomas treated by means of TC route
(1989-1998)--I group, were compared to 57 cases operated on by means of TS
approach (1996-1999)--II group. The other tumours and re-operated patients were
excluded from the study. The following factors were compared: the size of treated
tumours, the radicality of tumour excision (subtotal, partial), the presence of
the massive hypothalamic dysfunction, the presence of diabetes insipidus, changes
in visual field, early results of treatment (good, bad, surgical deaths). Using
transsphenoidal approach significantly more tumours were removed subtotally
(except of large tumours), massive hypothalamic dysfunction was eliminated,
surgical deaths were reduced, and the chance for the improvement of the visual
field increased. In the last years more patients with small tumours were treated,
and less with medium-sized. Percent of patients with large tumours remains
unchanged. The prospective study should be performed to define the proper
planning of surgical treatment of large and giant tumours, including two-stages
procedures.
PMID- 10695378
TI - [Intraoperative manometry in laparoscopic antireflux procedures --indications,
methods and clinical results].
AB - The aim of the study is evaluating the efficiency of intraoperative manometry
during laparoscopic Nissen fundoplication and its ability to prevent
postoperative complications. METHOD: Sixteen patients with Gastroesophageal
Reflux Disease were included in the study. Clinical examinations, x-ray,
endoscopy, pH-metry, and manometric studies were performed before, and 3-6 m.o.
after surgery. Fourteen patients were undergoing Nissen fundoplication, and two
"floppy Nissen" fundoplications due to the specific preoperative manometric
indications. RESULTS: Postoperatively the mean proportion of time at pH < 4.0 on
pH-metry decreased from 188 min. (range 96-263) to 8.5 min. (range 2-25). Mean
number of reflux episodes significantly lowered after fundoplication from 18.9
(range 2-36) to 0.5 (range 0-3). Gastroesophageal junction mean pressure measured
postoperatively reached 24.7 mmHg, and was significantly higher than
preoperatively (8.9 mmHg). Mean length of LES increased from 1.2 cm (range 0.8
2.5) to 3.6 cm (range 2.4-4.6) postoperatively. CONCLUSIONS: Laparoscopic Nissen
fundoplication assisted by the simultaneous continuous intraoperative manometry
is feasible and effective procedure. Continuous LES pressure monitoring during
laparoscopic fundoplication with simultaneous computer-video assisted display can
be advised as an objective method of intraoperative evaluation of antireflux
mechanism.
PMID- 10695379
TI - [Determination of blood cell count and spleen size in patients with liver
cirrhosis submitted to endoscopic sclerotherapy for esophageal varices].
AB - Each of the 24 patients with bleeding oesophageal varices related to the liver
cirrhosis was submitted to 3-12 endoscopic sclerotherapies. During one year of
follow-up blood cell counts including erythrocytes, white blood cell,
neutorophiles and platelets, the size of spleen on ultrasound were assessed.
After a year we noticed marked, statistically significant decline in white blood
cells, neutrophiles and platelets counts. The size of the spleen remained
unchanged. We may conclude that repeated sclerotherapy of oesophageal varices
does not contribute to the rise in blood pressure within the portal system while
decrease in blood cells count might be attributed to deterioration of the liver
function.
PMID- 10695380
TI - [Radionuclide diagnosis of tricuspid regurgitation as a method of estimating the
significance of tricuspid insufficiency with concurrent mitral valve disease].
AB - A mitral valve replacement without simultaneous correction of a concomitant
tricuspid regurgitation aggravates remote postoperative results. Nowadays
diagnostics of a degree of tricuspid regurgitation bases on semi-quantitative
methods, which are not unequivocal criteria of a significant tricuspid
insufficiency. The aim of the study was to investigate diagnostic usefulness of a
radioisotopic method of determination significant tricuspid insufficiency. The
study group consisted of 35 patients with rheumatic mitral valve disease and
tricuspid regurgitation (30 females, 5 males) at a mean age of 55 years qualified
for operative treatment. Physical and noninvasive examinations were performed in
all patients: chest X-ray (relative heart volume--RHV) and echocardiographicy
(tricuspid regurgitation and right ventricle pressure). Final determination of a
significant tricuspid insufficiency based on intraoperative diagnosis. The
radioisotopic method relies on first pass technique with a determination of a
tricuspid regurgitation index (TRI) and a right ventricular ejection fraction.
Intraoperatively the patients were divided into two groups: with significant
tricuspid regurgitation--21 patients and without--14 patients. Statistically
significant differences, considering clinical and echocardiographic assessment
between the two groups were noticed. The TRI index did not differentiate two
groups. Noninvasive parameters that could affect diagnosis of significant
tricuspid regurgitation were proved by a logistic regression analysis. Among them
the TRI Index could have a separate value. CONCLUSIONS: Presented radioisotopic
method of determination a degree of tricuspid regurgitation with the new TRI
Index is of value in diagnosing significant tricuspid insufficiency when assessed
with other noninvasive parameters. Estimation of a clinical usefulness of the
method needs further investigation and bigger study group.
PMID- 10695381
TI - [Evaluation of noradrenaline and atrial natriuretic hormone concentration in
blood serum of pharmacologically untreated patients with chronic heart failure].
AB - Heart failure is a condition of increased neurohormonal stimulation the level of
which is affected by both the rate of clinical advancement of the disease and by
the manner of its treatment. Hence the work of determining the level of the
neuroendocrine activation of the plasma within the range of the adrenergic system
and of the atrial natriuretic hormone in not pharmacologically treated patients
with mild and moderate heart failure. Consistently investigated were the
concentrations of noradrenaline and of the atrial natriuretic hormone in 9
patients (mean age 66.3 years) and the results of the determinations were
compared with data of the age approximate group of healthy persons. Then shown,
too, could be the concentration increase of noradrenaline and of the atrial
natriuretic hormone (both comparisons p < 0.001) over the values that are found
in healthy people.
PMID- 10695382
TI - [The value of evaluating tumor markers: CA 15-3 and ferritin in blood serum of
patients grouped as "high risk" for breast cancer].
AB - We studied 127 patients. 35 patients (group I) with mastopathy disease (average
44.3 years old) included 9 patients with a breast cancer family history (subgroup
I A), 26 patients without a breast cancer family history (subgroup I B) and 92
patients (group II) with a breast cancer of I-IV grade (average 49.25 years old).
The results of the study revealed statistically significant higher level of CA 15
3 in serum of patients with mastopathy compared to patients with a breast cancer
of I grade (p < 0.05). CA 15-3 level in patients with a breast cancer of III, IV
grade in serum, was considerably higher and there was significant difference
comparing to the patients with a breast cancer of I, II grade (p < 0.001) and
patients with mastopathy disease. There were also higher average levels of CA 15
3 in patients with mastopathy disease with a breast cancer family history
(subgroup I A) compared to patients without an oncological risk (subgroup I B),
however there were not significant differences. There were also higher average
levels of ferritin revealed in patients with a breast cancer of III, IV grade and
which shows significant difference between patients with breast cancer of I, II
grade and with mastopathy patients (p < 0.001). It seems that determination of CA
15-3 and ferritin in patients of a high risk group of a breast cancer could be a
useful diagnostic tool for early determination of a breast cancer.
PMID- 10695383
TI - [Telomeres and telomerase in leukemias].
AB - There is increasing evidence that telomere shortening both in vitro and in vivo
is the clock that counts cell divisions and determines the onset of cellular
senescence. Cells overcome the normal senescence mechanism by stabilising
telomere length; probably due to the activity of telomerase activity that
specifically elongates telomeres. Most human primary tumors contain telomerase,
while the cells of most normal tissues lack this activity. Normal haematopoietic
cells express telomerase activity. This review is a discussion of utility of
telomere length and telomerase activity measurements in the diagnostics and
prognosis of leukaemia as well as the potential value of antitelomerase therapy.
Results of telomere lengths measurements in young recipients of allogenic
transplants are also reported.
PMID- 10695384
TI - [Restenosis after percutaneous transluminal coronary angioplasty and its
prevention].
AB - The high prevalence of restenosis is considered as a main problem concerning
transluminal coronary angioplasty--known and popular invasive method of treatment
of coronary heart disease. Mechanisms responsible for vascular wall healing and-
also--restenosis as well as the role of cells and its mediators are discussed.
The prevention of restenosis is a big challenge for contemporary medicine. The
investigations concerning methods which theoretically seem to be justified are
being conducted. Unfortunately the results of many trials are unconvincing. At
present the most important ways of prevention of restenosis are stent
implantation and antiplatelet drugs.
PMID- 10695385
TI - [Genetic aspects of primary hyperparathyroidism].
AB - The results of the last decade genetic research in the field of oncogenesis of
sporadic and familiar parathyroid tumors are summarised. The review of studied
focuses on two main topics: multiple endocrine neoplasis syndromes as well as
sporadic parathyroid adenomas and carcinomas. The current knowledge of genetic
factors associated with the development of these lesions is presented.
PMID- 10695386
TI - [Retrosternal parathyroid gland cystic neoplasm as a cause of primary
hyperparathyroidism].
AB - Parathyroid carcinoma is a rare cause of primary hyperparathyroidism (1-2%). In
this paper a case of parathyroid cancer of the right inferior parathyroid gland
cyst (5 cm in diameter) localised mostly retrosternally is presented in a patient
suffering from severe hypercalcaemia (Ca--3.7 mmol/l, Ca(++)--1.8 mmol/l), severe
bone pains and weakness, huge osteoporosis with following L5 compression fracture
and recurrent nephrolithiasis. PTH blood level before surgical treatment was 1243
pg/ml (Norm: 10-60 pg/ml). In the preoperative ultrasonography of the neck, a
lesion was found, but it was considered to be a cyst in the inferior pole of the
right thyroid lobe. In a fine-needle biopsy from the lesion-colloid mass without
any cells was found. In a 99mTc-MIBI scintigraphy of the neck a suspicion of
focus lesion in the right superior parathyroid gland was made, which was not
confirmed intra-operatively. Parathyroid carcinoma was diagnosed intraoperatively
in histological examination. 'En block' resection of the retrosternal parathyroid
tumor and right thyroid lobe was performed from the jugular incision. Any
enlarged jugular lymph nodes were not found. In a postoperative period a
transient hypocalcaemia was present, which disappeared after pharmacological
treatment. During 32 months of follow-up neither no features of local recurrence
nor distant metastases were found. Calcium level in blood was normal, PTH 216.0
pg/ml, severity of bone pains and weakness lessened, osteoporosis in a course of
pharmacological treatment--with no further progress.
PMID- 10695387
TI - [The coexistence of an intracranial tumor and a positive epidemiologic history of
Lyme borreliosis as the reason for diagnostic problems--case report].
AB - The authors present the case of a patient treated in the Department of Infectious
Diseases at CMUJ in Cracow. The patient's full clinical picture suggested the
possibility of the development of neuroborreliosis and disguised the symptoms of
a developing intracranial tumor. Neuroborreliosis was suspected due to
epidemiologic history (a tick bite, erythema migrans), general symptoms (fatigue,
hypersomnia, apathy, dysmnesia, concentration disorders) and neurological
symptoms, seropositive tests for Borrelia burgdorferi in serum and cerebrospinal
fluid (IgG), increased protein concentration in cerebrospinal fluid. Owing to the
fact that the serologic criteria of neuroborreliosis were not fulfilled, and
other symptoms (loss of consciousness) appeared, CT was done. The CT showed the
presence of a tumor in the longitudinal fissure of the brain, which, after
intraoperative and histopathological examination, was defined as meningioma.
PMID- 10695388
TI - [Two cases of rare abdominal hernias].
AB - Two cases of rare abdominal hernias were presented: sciatic and obturator. Both
presented cases confirm diagnostic difficulties, often leading to delay in
therapy. The best way to reduce mortality in these patients seems to be the
increase of number of preoperative diagnoses. In obturator hernia's diagnosis the
attention is payed to Romberg's symptom, although in sciatic--to symptoms of
sciatic nerve irritation or anuria. All diagnostic doubts should be solved with
the help of herniography or pelvic CT.
PMID- 10695389
TI - [A Polish physician's impressions from the Viennese Clinic of Winternitz].
AB - The achievements of Vincenz Priestnitz, Sebastian Kneipp and Wilhelm Winternitz
for the development of hydrotherapy are presented at the beginning. The
professional and scientific activities of Winternitz are strongly pointed out.
Eugeniusz Piasecki (1872-1947), the Polish physician and theorist of physical
education impressions from Vieneese Clinic of Winternitz are depicted widely. The
role of Winternitz in formation of modern hydrotherapy in Polish territories is
presented finally.
PMID- 10695390
TI - [How a Warsaw physician helped Sienkiewicz in his literary debut].
AB - This article is on the borderline between history of medicine and history of
literature. The life and works are presented of Konrad Dobrski (1849-1915), with
description of his works in Warsaw and scientific visits to Vienna. He was a well
known Warsaw's physician, especially in laryngology and pulmonology. His friendly
relations with Henryk Sienkiewicz, a famous Polish writer, in adolescence are
described in more details. The Dobrski's participation in origin of first
Sienkiewicz's novel "Na marne" is presented with full particulars. The Jozef
Ignacy Kraszewski's assistance in this matter is also depicted.
PMID- 10695391
TI - [Analysis of pulmonary function in leukemia patients after bone marrow
transplantation: effects of prior chemotherapy].
AB - To evaluate the effects of prior chemotherapy on pulmonary function after bone
marrow transplantation(BMT), pulmonary function tests were performed prior to and
after BMT on 7 acute leukemia (AL) and 13 chronic myelogenous leukemia (CML)
patients given with CY (60 mg/kg x 2 days), total body irradiation (3 Gy x 4
days, 10 cGy/min), and CyA plus short-term MTX. No patient had graft-versus-host
disease or lung complications. Pulmonary function after BMT did not deteriorate
in the AL patients; however, both %Vital Capacity(%VC) and DL/VA decreased
significantly in the CML patients (%VC before BMT: 112.1 +/- 11.5%, after BMT:
93.7 +/- 9.4%; DL/VA before BMT: 79.2 +/- 14.6%, after BMT: 54.1 +/- 10.6%).
Although prior regimens of busulfan (BU) or interferon (IFN) were equal risk
factors for decreased %VC after BMT, decreases in DV/VA were more significant in
CML patients who received IFN. CML patients, especially those who have received
BU or IFN, should be carefully monitored for pulmonary function to prevent
respiratory failure after BMT.
PMID- 10695392
TI - [Low-dose prednisolone therapy for idiopathic thrombocytopenic purpura].
AB - Prednisolone (PSL) is widely used for the treatment of idiopathic
thrombocytopenic purpura (ITP). We compared the effects of a relatively low dose
(0.5 mg/kg/day, LD group) of PSL and the conventional dose (1.0 mg/kg/day, CD
group) on 59 ITP patients. Twenty-six patients were treated with low-dose PSL,
and 23 patients with the conventional dose. No statistically significant
difference was observed in the complete remission rates for the LD group (35%)
and the CD group (39%). However, the mean duration of hospitalization was
significantly (p < 0.001) shorter for LD group patients than for patients in the
CD group (20 days versus 50 days, respectively). In conclusion, low-dose PSL may
be as effective as the conventional dose and capable of reducing the cost of
hospitalization, thus, improving the quality of life for patients with ITP.
PMID- 10695393
TI - [A retrospective study of the length of hospitalization following allogeneic bone
marrow transplantation].
AB - To estimate the length of hospitalization following bone marrow
transplantation(BMT), we conducted a retrospective study of 190 patients who had
received allogeneic BMTs at our institution. By our criteria, patients were
considered ready for discharge if they were afebrile, did not need intravenous
chemotherapy or blood transfusions more than 2 times per week, had maintained
these conditions for 1 week or more, and also had no medical history of hepatic
veno-occlusive disease, grade-II-or-higher graft-versus-host disease,
interstitial pneumonitis, or severe hepato-renal dysfunction. The median length
of hospitalization was 108.5 days. Of 82 patients who satisfied our discharge
criteria by their 70th hospital day, 10 experienced mild complications during the
next 30 hospital days. Of 89 patients who were considered ready for discharge by
the 40th hospital day, 30 and 38 experienced complications during the next 30 and
60 hospital days, respectively, and 16 required emergency treatment. No
significant baseline characteristics distinguished the patients who experienced
complications from those who did not, either after 40 or 70 hospital days. This
compounded the difficulty of predicting the development of complications in
patients who satisfied our discharge criteria. Although management on an
outpatient basis should be safe and feasible for BMT patients who meet our
discharge criteria by the 70th day of hospitalization, caution is advised for
early discharges after only 40 hospital days.
PMID- 10695394
TI - [Varicella-zoster virus infection after hematopoietic stem cell transplantation].
AB - Of 264 patients aged 15 years or more who underwent hematopoietic stem cell
transplantation between 1989 and September 1998 at the Tokyo Metropolitan
Komagome Hospital, 47 were infected by the varicella-zoster virus (VZV). In 2
patients, visceral disease preceded cutaneous dissemination. One of these
patients exhibited gastrointestinal symptoms followed by disseminated skin rash 6
days later. In the other patient, epigastralgia developed and was followed by
seizures secondary to meningitis; the appearance of a skin rash 5 days after
these initial symptoms yielded the diagnosis. Early diagnosis and treatment of
VZV infection are important, especially for patients who present with visceral
symptoms suspected to be due to VZV.
PMID- 10695395
TI - [Bone marrow transplantation-associated thrombotic microangiopathy manifested by
visual disturbance].
AB - In October 1996, a 26-year-old woman was given a diagnosis of acute myeloblastic
leukemia, FAB subtype M1. Treatment with combined chemotherapy achieved a
complete remission (CR). In May 1997, the patient received an allogenic bone
marrow transplant (BMT) from an HLA-identical sibling donor. Cyclosporine (CsA)
and short-term methotrexate were given for graft-versus-host disease (GVHD)
prophylaxis. Successful engraftment was obtained and signs of acute or chronic
GVHD never developed. Five months after BMT, the patient experienced low-grade
fever and blurred vision. Retinal examination demonstrated intraretinal
hemorrhages, cotton-wool spots, and retinal detachments, which were presumably
attributable to multiple thrombosis of retinal microvessels. The patient also
exhibited hemolytic anemia with red cell fragmentation, thrombocytopenia,
elevated lactate dehydrogenase, and renal impairment, and was thus given a
diagnosis of BMT-associated thrombotic microangiopathy (BMT-TM). Discontinuation
of CsA and administration of ticlopidine and prednisolone induced successful
recovery from BMT-TM. Three months after the onset of BMT-TM, however, the
patient experienced generalized clonic-tonic seizures with consciousness loss.
Single-photon-emission computed tomography revealed blood-flow disturbances in
the brain, suggesting the recurrence of microthrombosis. Accordingly, multiple
transfusions of fresh frozen plasma were administered together with dipyridamole
and aspirin. The patient gradually recovered and remained asymptomatic through
the following 13 months. Currently, early diagnosis of BMT-TM is considered to be
difficult. We suggest that careful examination of the ocular base may be useful
for the early detection of BMT-TM.
PMID- 10695396
TI - [CD56-positive adult T-cell leukemia manifested by abnormal lung shadows].
AB - A 54-year-old woman was admitted to Juntendo Izunagaoka Hospital on Aug. 29,
1998, after experiencing cough and fever for 19 days. Chest X-ray films disclosed
infiltrates in the left lung field. The abnormal lung shadows progressed despite
antibiotic therapy, and enlargement of superficial lymph nodes and
hepatosplenomegaly developed. Peripheral blood examination disclosed cleaved
lymphoid cells without granular cytoplasm. Anti-HTLV-I antibody titer was x320,
and the monoclonal integration of HTLV-I provirus was confirmed by Southern blot
analysis. Surface marker analysis of lymph node cells was positive for CD2, CD3,
CD4, CD5, CD56, and HLA-DR. The above results yielded a diagnosis of adult T-cell
leukemia. LSG-4 therapy alleviated the lung infiltrations and dyspnea. This case
was considered unusual because of the expression of the natural killer cell
marker CD56 on leukemic cells and the presentation of abnormal lung shadows
possibly due to leukemic cell infiltration.
PMID- 10695397
TI - [A boy with summer onset paroxysmal cold hemoglobinuria induced by Donath
Landsteiner antibody with anti-I specificity].
AB - We encountered 4-year-old boy who developed paroxysmal cold hemoglobinuria (PCH)
in the middle of August. He was admitted due to progressive jaundice and pallor
following fever and nausea. Laboratory data revealed severe anemia, increased
serum indirect bilirubin and LDH, and decreased serum haptoglobin.
Direct/indirect Coombs tests were positive. These findings yielded a diagnosis of
autoimmune hemolytic anemia. Serological test for syphilis was negative. The
patient's symptoms and signs promptly subsided after treatment with prednisolone,
which was started on the 2nd hospital day. The patient has been in a disease-free
state for 16 months without any medication. After discharge, he was finally given
a diagnosis of PCH because a Donath-Landsteiner test was positive. The antibody
belonged to an IgM subclass and showed anti-I specificity. Considering that
development of PCH is common in winter, this case was unique because it developed
in August. We speculated that exposure to a cool air-conditioned atmosphere prior
to hospitalization and the cooling mechanism of the body after admission were
involved in the summer onset of PCH and its prolonged clinical course.
PMID- 10695398
TI - [Sustained long-term complete remission in an elderly aplastic anemia patient
after cessation of combined therapy consisting of granulocyte-colony stimulating
factor and erythropoietin].
AB - An 83-year-old woman received a diagnosis of moderate aplastic anemia in November
1990. Immunosuppressive therapy consisting of anti-lymphocyte globulin combined
with high-dose corticosteroids was effective until pancytopenia developed in
August 1993. The patient was hospitalized again and recurrence of aplastic anemia
was diagnosed on the basis of hematologic findings, including RBC 129 x
10(4)/microliter, Hb 5.5 g/dl, Ret 23,200/microliter, WBC 2,200/microliter with
27% neutrophils, platelets 2.2 x 10(4)/microliter, and hypoplastic bone marrow.
Recombinant human granulocyte-colony stimulating factor (G-CSF) of 125
micrograms/day combined with recombinant human erythropoietin (EPO) of 6,000
U/day were started in November 1993. The doses of G-CSF and EPO were increased to
250 micrograms/day and 12,000 U/day, respectively. We stopped combination therapy
in March 1995, after trilineage hematopoietic cell recovery had been achieved.
Complete recovery in peripheral blood was sustained for more than 2 years despite
the termination of G-CSF and EPO therapy. Combination therapy with G-CSF and EPO
may be safe and effective for elderly patients with aplastic anemia when the
choice of therapy is limited.
PMID- 10695400
TI - [Histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto's disease) accompanied
by hemophagocytosis and salivary gland swelling in a patient with systemic lupus
erythematosus].
AB - After 2 years of steroid therapy that had effectively controlled her systemic
lupus erythematosus, a 37-year-old woman presented with fever, erythema (face,
upper chest), and low CH50. Increased oral steroid (prednisolone from 15 mg to 40
mg) and intravenous methylprednisolone (mPSL) (80 mg for 3 days) alleviated these
symptoms except for the fever. Subsequently, the patient's fever worsened and
leukocytopenia, abnormal liver function, lymphadenopathy (neck, axilla), and
salivary gland swelling developed. Lymph node histology revealed features
characteristic of Kikuchi-Fujimoto's disease (KFD). Laboratory examinations
showed WBC 600/microliter, Hb 9.5 g/dl, platelets 90,000/microliter, GOT 766
IU/l, GPT 646 IU/l, LDH 4,228 IU/l, TG 1,622 mg/dl, and ferritin 6,330 ng/ml.
Serum interferon gamma was also elevated (673 U/ml). Because a bone marrow smear
revealed hemophagocytosis, mPSL pulse therapy (1 g for 3 days) was started for
treatment of hemophagocytic syndrome. The fever promptly disappeared, and the
patient's clinical symptoms resolved within 2 weeks. The abnormal laboratory data
related to KFD and hemophagocytosis returned to normal within 4 weeks after the
initiation of mPSL pulse therapy. We speculated that the hemophagocytosis and
salivary gland involvement in this patient were also symptoms of KFD. This case
indicated that corticosteroid pulse therapy is effective for KFD with serious
clinical symptoms.
PMID- 10695399
TI - [Two cases of orbital non-Hodgkin's lymphoma presenting with hemophagocytic
syndrome].
AB - We report 2 cases of orbital non-Hodgkin's lymphoma (NHL) with hemophagocytic
syndrome (HPS). Patient 1 was a 64-year-old man with a diagnosis of peripheral T
cell lymphoma originating in the right orbita (clinical stage: IV B). Epstein
Barr virus DNA was demonstrated in tissue specimens by polymerase chain reaction.
Laboratory findings on admission were WBC: 4,700/microliter, Hb: 12.1 g/dl, Plt:
14.6 x 10(4)/microliter, LDH: 951 IU/l, sIL-2R: 2,553 IU/ml, and ferritin: 5998.1
ng/ml. Patient 2 was a 73-year-old man with a diagnosis of diffuse large B-cell
lymphoma originating in the right orbita (Clinical stage: IV B). Laboratory
findings on admission were WBC: 9,100/microliter, Hb: 7.7 g/dl, Plt: 15.4 x
10(4)/microliter, LDH: 1,043 IU/l, sIL-2R: 10,090 IU/ml, and ferritin: 2079.3
ng/ml. Both patients had high-grade fever and extremely high serum cytokine
levels. Bone marrow aspiration disclosed many histiocytes with hemophagocytosis.
In both cases, combined chemotherapy was transiently effective, but patient 1
died of relapse of HPS and patient 2 of cerebral bleeding. Orbital non-Hodgkin's
lymphoma with HPS is rare. These cases were interesting in terms of the
relationship between HPS and the primary site of lymphoma.
PMID- 10695401
TI - [beta-thalassemia minor diagnosed in a patient with chronic myelogenous leukemia
during hydroxyurea therapy].
AB - A 55-year-old man was admitted to our hospital because of leukocytosis and
microcytic anemia with hypochromia, target cells, and increased levels of
hemoglobin A2 and hemoglobin F. The results of a gene analysis yielded a
diagnosis of chronic myelogenous leukemia and beta-thalassemia minor. A gradual
increase in hemoglobin was observed during hydroxyurea therapy, which was
performed over a 12-week period. This increment appeared to be due to suppressed
production of myeloid cells. It was been reported that hydroxyurea increases
total hemoglobin due to increased hemoglobin F synthesis in patients with beta
thalassemia. However, hydroxyurea had no clear influence on hemoglobin
concentration in this case.
PMID- 10695402
TI - [An aplastic anemia patient died of severe anemia who refused transfusion].
AB - A 41-year-old woman who had been given a diagnosis of aplastic anemia 14 years
before was admitted because of recurrence of the disease. Despite therapy, the
anemia progressed gradually. The patient refused blood product transfusions for
religious reasons. Angina pectoris-like chest pain without ischemic changes on
electrocardiograms appeared at a hemoglobin concentration (Hb) of 1.6 g/dl. The
patient died of heart failure at Hb 1.5 g/dl. Autopsy showed enlargement of the
heart, fatty changes in the myocardium and liver due to chronic hypoxia, and no
changes in coronary arteries.
PMID- 10695403
TI - [Essential thrombocythemia in transformation from myelodysplastic syndrome to
acute myeloid leukemia with inv(3) after treatment for gastric cancer].
AB - In March 1990, a 61-year-old man was given a diagnosis of essential
thrombocythemia with a normal karyotype and subsequently treated with
hydroxyurea. In November 1995, he underwent surgery for gastric cancer with
thereafter received tegafur/uracil for 2 years. Refractory anemia with excess of
blasts in transformation and chromosomal abnormalities including -5, -7, 20q
developed in August 1998. Combined chemotherapy with daunorubicin, cytarabine,
mercaptopurine, and prednisolone, had only limited effectiveness. Acute myeloid
leukemia was finally diagnosed in October 1998, and chromosomal analysis
disclosed inv(3) in addition to -5 and -7. The appearance of inv(3) might be
related to leukemic transformation of hematopoietic stem cell disease with an
increase in the number of megakaryocytes and platelets.
PMID- 10695404
TI - [My recent daily life especially on hemo dialysis].
PMID- 10695405
TI - [Nation-wide survey for the treatment with cyclosporin A of interstitial
pneumonia associated with collagen diseases].
AB - OBJECTIVES: This study was performed to investigate the efficacy and safety of
cyclosporin A (CsA) for the treatment of interstitial pneumonia (IP) associated
with collagen diseases in Japan. METHODS: Questionnaires were sent to 36
hospitals specializing in collagen diseases. RESULTS: Fifty-eight patients (7
polymyositis (PM), 19 dermatomyositis (DM), 7 systemic sclerosis (SSc), 7
rheumatoid arthritis (RA), 2 mixed connective tissue disease (MCTD), 1 systemic
lupus erythematosus (SLE) and 1 Sjogren's syndrome (SS), 1 RA + SSc, 2 PM + SSc,
1 DM + SLE, and 10 idiopathic interstitial pneumonia (IIP) with IP were treated
with CsA at 14 hospitals. IP was classified into the acute or chronic type. In
the PM/DM group (7 PM, 19 DM, 2 PM + SSC, 1 DM + SLE), 65.5% were the acute type.
In the other collagen disease group (7 SSc, 7 RA, 2 MCTD, 1 SLE, 1 SS, and 1 RA +
SSc) and IIP group, 36.8% and 50% were the acute type, respectively. Mean dosages
of CsA were 3.7 +/- 1.3 mg/kg/day for the PM/DM group, 3.0 +/- 1.0 for the other
collagen disease group, and 3.8 +/- 4.8 for the IIP group. Oral corticosteroids
were administered in combination with CsA in 100, 73.7, and 70% of the patients
with PM/DM, other collagen disease, and IIP groups, respectively. CsA was
effective for 72.2, 33.3, and 25% of the acute IP cases in the PM/DM, other
collagen disease, and IIP groups, respectively. CsA was effective for 50.0, 50.0,
and 60.0% of chronic IP cases in the PM/DM, other collagen disease, and IIP
groups, respectively. Twenty-three adverse effects were observed, but most of
them ameliorated upon withdrawal or reduction of the CsA dose. CONCLUSION: CsA is
effective for the treatment of acute type IP associated with collagen diseases,
especially PM/DM. To perform a prospective multi-center trial, standards for the
recruitment of patients, efficacy assessments, and trial course and treatment
should be determined carefully.
PMID- 10695406
TI - [Improvement of the maintenance therapy after methylprednisolone pulse therapy-
effect of prednisolone combined with immunosuppressants].
AB - OBJECTIVES: We investigated the effect of the combination therapy of prednisolone
(PSL) and immunosuppressants after methylprednisolone pulse therapy. METHODS: A
protocol of PSL (15-20 mg/day) and mizoribine (150-200 mg/day) after
methylprednisolone (mPSL) pulses was used for 2 years to treat 7 patients (PSL +
MZB group). Cyclophosphamide (CYC) pulse therapy was added to the combined
therapy in 4 patients with severe lupus nephritis. The total dose of
predinisolone, and side effects were compared with those in 6 patients who were
treated with PSL (30 mg/kg) alone after mPSL pulse therapy (PSL group). RESULTS:
No relapses occurred in the PSL + MZB group, although all of 6 patients relapsed
in the PSL Group. The total doses of PSL in the PSL + MZB group was about 70% of
the PSL Group. There were two patients with Herpes-Zoster infection and one
patient with liver dysfunction as side effects, with no differences in the
frequency of side effects between the was groups. CONCLUSIONS: Combination
maintenance therapy with prednisolone and immunosuppressants after
methylprednisolone pulse therapy was effective in preventing relapse.
PMID- 10695407
TI - [A case of amyopathic dermatomyositis presenting blister and oral ulcer].
AB - An 84-year old man was admitted to Mitoyo General Hospital because of progressive
malaise and edematous erythema on both eyelids (Heliotrope erythema). He also
noted blister on his neck as well as erythema on the extensor surface of finger
joints (Gottron's sign), elbows and knees. Neither weakness nor pain of his
proximal muscle was elicited on physical examination on admission. His blood test
disclosed positive inflammatory signs (i.e., mild elevation of ESR and positive
CRP) without elevated value of muscle enzymes. Electromyogram showed normal
pattern. Infiltration of inflammatory cells was not revealed by histological
examination of biopsied muscle. A diagnosis of 'amyopathic dermatomyositis' was
made based on these observations. Computed tomography of his chest disclosed
interstitial pneumonia spreading over both lower lung fields. Colon fiberscopy
revealed a polyp in his descending colon, which was classified into group I on
cytological examination. He was treated with two sets of methylprednisolone
(mPSL) pulse therapy (500 mg/day, 3 consecutive days, intravenously) followed by
30 mg/day of oral prednisolone (PSL). His skin lesions responded well to the
above treatment and the dose of oral PSL was tapered. One month after the
initiation of treatment, severe stomatitis as well as a large ulcer beneath his
tongue developed accompanying an intractable pain. Mucosal biopsy revealed
necrotizing vasculitis in medium-sizedartery at the bottom of ulcer. Another set
of mPSL pulse therapy brought a prompt relief of his symptom and prohibited the
recurrence of oral lesion. It should be noted that our patient did not fulfill
the diagnostic criteria for DM because of the lack of muscular symptoms whereas
he had characteristic skin lesions. Regarding the frustration possibly
encountered at the time of diagnosing amyopathic DM, both sensitivity and
specificity of the skin lesion for the diagnosis of DM were investigated.
Moreover, the rarity of blister as a skin manifestation of DM was discussed as
well.
PMID- 10695408
TI - [Two cases of silicosis exhibiting MPO-ANCA associated disorder].
AB - We reported two cases of silicosis exhibiting MPO-ANCA associated disorder. Case
1 was a 69 year-old man with silicosis and chronic interstitial pneumonia. He was
admitted because of fever, dry cough, left chest pain, dyspnea and body weight
loss. He was diagnosed as acute exacerbation of interstitial pneumonia,
pericarditis and gastrointestinal bleeding. Case 2 was a 67 year-old man with
silicosis. He repeated attack of fever, hoarseness, dysphagia and headache. The
cell counts of cerebrospinal fluid increased and the thickness of cerebellar tent
and left dura mater was observed in the brain MRI. Therefore, he was diagnosed as
pachymeningitis and neuropathy of cranial nerves. Both cases were complicated by
silicosis and the laboratory findings showed high serum levels of P-ANCA, ANA and
rheumatoid factor and inflammatory responses, indicating they were suspected
vasculitis. The two cases were treated by steroid and immunosuppressive therapy
and had good clinical response. Silicosis may affect multiple organ involvement
associated with P-ANCA.
PMID- 10695409
TI - [A case of Sjogren's syndrome with retrobulbar optic neuritis and cutaneous
vasculitis].
AB - A 52-year-old woman, diagnosed as having Sjogren's syndrome by parotid
sialography and lip biopsy after a two years history of recurrent purpuric rashes
on her lower extremities, was admitted to our hospital because of visual
disturbance in March 1998. On presentation at the department of ophthalmology,
her right visual acuity was light perception, and laboratory findings showed
elevated levels of antinuclear antibody and anti-Ro/SS-A and anti-La/SS-B
antibodies. Cerebrospinal fluid analysis showed mild pleocytosis and elevated
levels of total protein and Q-albumin. The IgG-index was within normal level and
no oligoclonal band was found. Magnetic resonance imaging showed increased signal
intensity at the right optic nerve. After treatment with m-PSL pulse therapy, her
visual acuity recovered to 0.08. When prednisolone was gradually tapered to the
dose of 30 mg per day, she was transferred to our department because of high
grade fever and pancytopenia. She also suffered from palpable purpura in her
extremities extending the trunk, whose pathological diagnosis was
leukocytoclastic vasculitis. The immunohistochemical examination showed
depositions of IgG and C1q. After two additional cycles of mPSL pulse therapies,
clinical improvement was achieved. The titers of von Willebrand factor and
thrombomodulin correlated with her clinical improvement. Patients with Sjogren's
syndrome can develop extra-grandular complications, including neurologic and
cutaneus diseases, it is important to understand the role of SS-A-B antibodies in
the immunopathogenesis of Sjogren's syndrome.
PMID- 10695410
TI - [An autopsy case of aortitis resulting in a tear of the aortic valve due to a
rupture of the aneurysm of Valsalva's sinus].
AB - A 43-year-old man was admitted to a hospital because of acute dyspnea and
nocturnal orthopnea. Echocardiogram and chest CT showed the dilation of thoracic
aorta from the root to ascending portion. On the third hospital day, he died
suddenly. At autopsy, the cause of death was indicated to be a tear of an aortic
valve due to a rupture of the aneurysm of Valsalva's sinus, followed by acute
aortic regurgitation and acute cardiac insufficiency. Histopathological findings
of thoracic aorta revealed mesoaortitis, characterized by patchy destruction of
the media with a moth-eaten appearance of the medial elastic laminae and a
microgranuloma formation, a perivascular mononuclear cell infiltration of the
vasa vasorum, and a fibrous thickening of the intima and adventitia. However,
there were no abnormalities in main branches of aorta and abdominal aorta, and no
systemic vasculitis. This case is a rare one in the clinical course, and may be
important to be differentiated from other cases with aortitis, especially
Takayasu arteritis and syphilitic aortitis.
PMID- 10695411
TI - [The recent progress of the treatment for chronic idiopathic arthritides of
childhood].
PMID- 10695412
TI - [Rheumatoid arthritis and human parvovirus B 19].
PMID- 10695413
TI - Nitric oxide--the magic molecule.
PMID- 10695414
TI - Cytokines and inflammatory bowel disease.
AB - Cytokines are the key mediators of inflammation in the IBD and are focus of
renewed interest to plan therapeutic strategies against this disease. However,
there are gaps in our knowledge at present and a lot of questions need clear
answers. Even with a therapy as specific as anti-TNF antibody, it is not clear if
the benefit is attributable to simple binding and clearance of TNF-alpha or to
binding on the cell surface and subsequent deletion of the activated macrophage.
When a drug appears to be less effective than pre-clinical models suggest, can
failures in effectiveness from delivery or dosing the differentiated? The
disappointing results of clinical trials with IL-10 is at odds with the
prediction of benefit from animal models. It even brings into question the
validity of those models as well as the soundness of design of the clinical
trials on which efficacy of IL-10 is assessed. Other exciting new methods to
treat IBD could be use of monoclonal antibodies to effector T cell molecules
(such as CD4 or CD44v7) removal of such cytokine secreting cells (apheresis),
antibodies to proinflammatory cytokines (such as TNF-alpha, IFN-alpha, IFN-gamma,
and IL-12) or administration of anti-inflammatory cytokines (such as IL-10, IL
11). Challenges in developing new therapeutic strategies include not only
identifying novel agents, but also improving the definitions of clinical
endpoints and defining efficacy at the biologic level. There is also need to
further refine our knowledge about genetic elements and environment initiators to
comprehensively manage IBD.
PMID- 10695415
TI - Clinical significance of carcinoembryonic antigen in colorectal malignancy.
AB - Carcinoembryonic antigen (CEA) assay was performed in 40 patients of
histologically proven colorectal carcinoma. The overall incidence of positivity
was 72.5%. The incidence increased from 40% in Duke's A stage to 84.6% in Duke's
C stage. Similarly the mean CEa levels also increased as the disease advanced
i.e. 4.96 ng/ml, 8.07 ng/ml and 12.7 ng/ml in Duke's A, B and C respectively.
Cancer with poor prognosis i.e. poorly differentiated and colloid carcinoma, had
significantly less rise in CEA values (P < 0.05) as compared to well
differentiated carcinoma. There was no relation of CEA values with the gross
appearance of the tumour and lymph node involvement. CEA level came down in all
the patients after surgery. Based on the postoperative CEA estimation, complete
tumour clearance had been achieved in 86.2% of patients.
PMID- 10695416
TI - Barrett's oesophagus and oesophageal cancer in Saudi Arabia.
AB - BACKGROUND/AIMS: Gastrooesophageal reflux disease (GERD) and Barrett's oesophagus
(BE) are presumed to be rare among non-western populations. This retrospective
survery determined the prevalence of BE and its associated complications of
dysplastic lesions (DL) and oesophageal adenocarcinoma (AD) among an Arabian
population. METHODOLOGY: From 2572 patients who had endoscopy in King Fahd
Central Hospital (KFCH) Gizan, Saudi Arabia, patients (n = 776) were selected for
analysis if they had biopsies of the upper gastrointestinal (UGI) tract. The
patients (159 of 776) with biopsy-proven oesophageal lesions were categorized and
compared. RESULTS: The relative frequencies of BE, DL and AD in 159 patients were
8(5%), 5(3%) and 16 (10%) respectively. These interpreted to prevalence rates of
0.31%, 1.9%, and 0.62% for the respective lesions. The comparison of the mean age
+/- SD (in years) of the patients with BE (59.6 +/- 19.8), DL (66 +/- 16.7) and
AD (70.6 +/- 12.2) showed to statistically significant difference. Major symptoms
in the patients with BE were dyspepsia (4 cases), hematemesis (2 cases) and
dysphagia (2 cases). This profile was not different from that observed in 79
patients with GERD. CONCLUSION: The prevalence of 0.31% in our endoscopy
population is at the lower range of the 0.3% to 10% reported in the western
world. It is likely that the rate was underestimated by this retrospective
survey, in which patients were selectively biopsied. Also, it is probable that
the majority of individuals in our population with no or minimal symptoms of GERD
do not present themselves or are not referred for evaluation. Despite this
limitation, our study confirms the occurrence of BE and its complications among a
Saudi population. The incidence of BE may increase with the current changes in
the life-style and increase in the life-span of the Saudi Arabian population.
PMID- 10695417
TI - Double blind controlled trial of effect of cisapride on gastric emptying in
diabetics.
AB - AIMS: Diabetic gastroparesis is a common complication seen in 20-50% of patients
due to autonomic neuropathy involving vagal supply. Cisapride, a specific
gastrointestinal cholinomimetic agent may thus be effective. METHODS: Fifty-one
diabetic patients (age 12-65 years) of disease duration > 5 years were assessed
for symptomatic gastroparesis, other diabetic complications and glycemic control.
Gastric emptying time (GET) was estimated using a solid meal method (99mTc
labeled rice based idli) and patients randomized to receive either cisapride or
placebo for a period of 2 weeks. Cisapride was administered in a dose of 10 mg
TID. GET and symptom scores were reassessed on the therapy after 2 weeks.
RESULTS: Twenty nine of 51 (56.8%) patients had gastroparesis. Mean GET in the
gastroparesis group was 141 +/- 66 minutes compared to 24.53 +/- 10 minutes in
the non gastroparesis group (p < 0.01). GET decreased by 72% amongst the patients
who received cisapride compared to 23% in the placebo group (p < 0.001). Symptom
scores also improved in the cisapride group; no adverse effects were noted.
CONCLUSIONS: Cisapride improves the symptom score and the solid gastric emptying
time in patients suffering from diabetic gastroparesis.
PMID- 10695418
TI - Assessment of malnutrition in alcoholic and non alcoholic cirrhotics.
AB - OBJECTIVE: To study the nutritional status in patients with chronic liver disease
using anthropometric techniques. METHODS: A total of 60 cirrhotic patients (30
Alcoholic (AC), 30 Non-alcoholic (NAC) and 30 control (CO) subjects were studied.
Nutritional status was assessed using anthropometric measurements such as
stature, body weight, body mass index, (BMI), skinfold thickness measurements and
mid upper arm muscle circumference. Serum protein, serum albumin and globulin
were measured. RESULTS: The skinfold thicknesses were significantly lower in NAC
group of patients. In contrast the AC group of patients showed significantly
lower mid upper arm muscle circumference values. Both groups of cirrhotic
patients showed significantly lower total serum protein and serum albumin levels.
CONCLUSION: Body fat is relatively more affected in NAC group of patients and
muscle mass is more affected in AC group of patients.
PMID- 10695419
TI - Gastric protection against cold restraint stress-induced lesions by amoxycillin
in rats.
AB - AIMS: Recent investigations have shown that amoxycillin possesses gastric
protection properties in addition to its known antimicrobial effects. Therefore,
this study was undertaken to investigate the potential gastric protection effects
of amoxycillin and to determine its possible mechanism(s) of action in rats.
METHODS: The cold restraint stress model was used to produce gastric mucosal
lesions. The gastric secretion studies were undertaken by using Shay's pylorus
ligation technique. The antioxidant effect was studied by luminol dependent
chemiluminescence technique in vitro. RESULTS: Amoxycillin dose-dependently
prevented cold restraint stress-induced mucus depletion and afforded protection.
It inhibited indomethacin-stimulated gastric acid secretion with a high dose
without affecting basal secretion. Furthermore, amoxycillin dose-dependently
inhibited the phorbol myristate acetate-stimulated luminol-dependent
chemiluminescence responses of isolated human poylmorphonuclear leukocytes in
vitro. CONCLUSIONS: These results suggest that mechanisms of gastric protection
effects of amoxycillin may include inhibition of stimulated acid secretion,
prevention of depletion of mucus and antioxidant properties.
PMID- 10695420
TI - Effect of hepatitis C virus coinfection on liver function of patients infected
with HIV.
AB - AIMS: Both the human immunodeficiency virus (HIV) and Hepatitis C virus (HCV)
share similar routes for their transmission, encouraging the possibility of a
coinfection with the two viruses in some individuals. We wanted to find out the
prevalence of HCV in patients infected with the HIV virus. METHODS: We tested 57
HIV positive patients for anti-HCV antibodies. Liver functions tests, ultrasound
abdomen and upper gastrointestinal endoscopy were carried out in the anti-HCV
positive patients. RESULTS: Coinfection with HCV was seen in 5.3% of patients. Of
these 2 had acquired the infections through blood transfusions and one through
heterosexual contact. One patient had cirrhosis with portal hypertension and one
had raised alkaline phosphatase as the only abnormality on liver function tests.
CONCLUSIONS: Because HCV is more infectious by the parenteral route, the
incidence of coinfection is lower in our population possibly due to the fact that
majority of our HIV positive patients acquire infection through heterosexual
contact.
PMID- 10695421
TI - A case of pancreatic hydatid disease.
PMID- 10695422
TI - Hereditary pancreatitis.
AB - Hereditary pancreatitis is a rare cause of chronic pancreatitis and has been
mainly reported in western literature. It is inherited in an autosomal dominant
manner. In this report, we present our data on two affected members in a family
from Punjab, North India.
PMID- 10695423
TI - Gastric adenocarcinoma--does the extent of lymphadenectomy matter?
PMID- 10695424
TI - Upper gastrointestinal diseases in Saudi Arabian children.
AB - In contrast to the experience in the adults, there are limited data concerning
the efficacy and safety of upper gastrointestinal endoscopy (UGIE) in paediatric
patients. The information on this procedure is very scanty from non-western
countries. We analysed 72 children evaluated in Gizan, Saudi Arabia, an area of
high endemic hepatitis B and chronic liver disease. The indications comprised
abdominal pain (49%), UGI bleeding (24%) and evaluation of suspected portal
hypertension. No abnormality was detected in 33 (46%). Mucosal inflammatory
lesions (oesophagitis, gastritis and duodenitis) are the commonest abnormal
lesions, occurring in 24 (33%). Duodenal ulcer (4 cases) and gastric ulcer (1
case) were relatively few. No case of malignancy was found. Sclerotherapy for
variceal bleeding was effective in 4 patients. Helicobacter pylori was detected
in 12 of 23 patients and associated with histologically identified gastritis in
the majority of these cases. It is concluded that paediatric UGIE is safe and
useful in the diagnosis and therapeutic intervention for UGI diseases in
children. Our findings provide additional information on the pattern of diseases
among Saudi Arabian children.
PMID- 10695425
TI - Extended survival of carcinoma head of pancreas following palliative treatment.
AB - A 48 year old woman presented with obstructive jaundice 10 years back. Upper
gastrointestinal endoscopy revealed a growth infiltrating the ampulla of Vater,
which was confirmed to be adenocarcinoma on cytology. At laparotomy, a large
nodular growth was seen in the head of pancreas. Surgical resection could not be
done because of encasement of superior mesenteric vessels, hence a
cholecystojejunostomy was performed. The patient remained asymptomatic for 9
years, when she developed cholangitis. Duodenoscopy at this stage revealed an
ulcerated growth at the ampulla and biopsy from the growth confirmed a well
differentiated adenocarcinoma. A straight flap 10 F stent was placed in the
common bile duct. Thereafter the patient has remained asymptomatic for more than
a year.
PMID- 10695426
TI - Gangrenous sigmoid volvulus in a pregnant woman.
AB - A rare case of gangrenous sigmoid volvulus in a pregnant woman causing intestinal
obstruction is reported. The patient had intrauterine foetal death. Laparatomy
for resection of sigmoid colon and hysterotomy for removal of dead foetus was
carried out. Terminal iliac colostomy with closure of rectal stump was done in
the first surgery. The patient underwent colorectal anastomosis 2 months after
the first operation and recovered uneventfully.
PMID- 10695427
TI - Giant non-parasitic hepatic cyst with biliary communication.
PMID- 10695428
TI - Treatment of substance misuse in the new century.
PMID- 10695429
TI - Congress and the Pain Relief Promotion Act.
PMID- 10695430
TI - Conflict, what conflict?
PMID- 10695431
TI - Functional foods: health boon or quackery?
PMID- 10695432
TI - More on herpes zoster lesions.
PMID- 10695433
TI - Should doctors disclose mistakes?
PMID- 10695434
TI - Toxicology and pathology of deaths related to methadone: retrospective review.
AB - OBJECTIVES: To clarify the mechanisms and risk factors of methadone toxicity and
to describe the findings of deaths related to methadone use Design Retrospective
review of case notes in the records of the San Francisco Medical Examiner
comparing the findings in cases where methadone was deemed the cause of death
with findings in decedents where methadone was an incidental finding, and with 50
age-matched, disease and drug free, trauma victims. RESULTS: 38 cases out of the
3317 processed by our office during 1997-1998 were identified in which methadone
had been detected. Cases were mostly male 28/38 (74%) and white, 28/38 (74%). In
17 of 38 cases death was deemed to have been caused by methadone toxicity. For
the group the mean blood methadone concentration for all 38 patients, was 957
ng/ml SD = .681, SE = .14). The mean blood concentration of the main methadone
metabolite (EDDP) was 253 ng/ml, SD = 529 ng/ml, SE = .089. The mean ratio of
methadone in the blood to EDDP in the blood was 13.6:1 Values were not
significantly different between cases in which methadone toxicity was the cause
of death and in those in which it was an incidental finding. Cocaine, or the
cocaine metabolite benzoylecgonine, was detected in the blood or urine of 16/38
cases (42%); morphine in one-third (13/38) and methamphetamine in only one.
Pulmonary edema was evident in all cases, coronary artery disease in 9/38 (24%)
and cirrhosis in 7/38 (18%) of the methadone users. Necrotizing fasciitis was the
cause of death in 4 of the 38 methadone users (11%). Nationally, a sizeable
percent of methadone deaths are from drugs diverted from treatment programs.
CONCLUSIONS: The presence of methadone is often an incidental finding during
postmortem examination which is unrelated to the cause of death. Postmortem
measurements of methadone or its metabolite, or both, cannot be used in isolation
to identify which deaths are associated with methadone toxicity.
PMID- 10695435
TI - Is methadone a miracle cure or an alternative evil?
PMID- 10695436
TI - Risk of hepatitis B infection among young injection drug users in San Francisco:
opportunities for intervention.
AB - OBJECTIVE: To compare the demographic characteristics and risk behaviors for
hepatitis B infection among injection drug users younger than 30 years with those
aged 30 or older and to evaluate participants' knowledge, attitudes, and
experiences of infection, screening, and vaccination against hepatitis B virus.
DESIGN: A systematic sample of injection drug users not currently in a treatment
program were recruited and interviewed at needle exchange programs and community
sites. PARTICIPANTS: 135 injection drug users younger than 30 years and 96
injection drug users aged 30 or older. RESULTS: Injection drug users younger than
30 were twice as likely as drug users aged 30 or older to report having shared
needles in the past 30 days (36/135 [27%] vs 12/96 [13%]). Injection drug users
younger than 30 were also twice as likely to report having had more than two
sexual partners in the past 6 months (80/135 [59%] vs 29/96 [30%]). Although 88
of 135 (68%) young injection drug users reported having had contact with medical
providers within the past 6 months only 13 of 135 (10%) had completed the
hepatitis B vaccine series and only 16 of (13%) perceived themselves as being at
high risk of becoming infected with the virus. CONCLUSION: Few young injection
drug users have been immunized even though they have more frequent contact with
medical providers and are at a higher risk for new hepatitis B infection than
older drug users. Clinicians caring for young injection drug users and others at
high risk of infection should provide education, screening, and vaccination to
reduce an important source of hepatitis B infection.
PMID- 10695437
TI - Vaccination could improve overall health in a high risk population.
PMID- 10695438
TI - Income inequalities and health disparities.
PMID- 10695439
TI - Slow-release morphine was not more effective than methadone in reducing neonatal
abstinence syndrome.
PMID- 10695440
TI - Brief physician advice reduced drinking in older adults.
PMID- 10695441
TI - Exercise training for patients with chronic heart failure reduced mortality and
cardiac events and improved quality of life.
PMID- 10695442
TI - Cost-effective evaluation of acute viral hepatitis.
PMID- 10695443
TI - All patients with acute hepatitis must be observed until the acute liver injury
resolves.
PMID- 10695445
TI - Does "white coat hypertension" increase the risk for any adverse outcome from
hypertension?
PMID- 10695444
TI - Use of methadone.
PMID- 10695446
TI - An elderly woman with a warm, painful finger.
PMID- 10695447
TI - Screening patients for alcohol, tobacco, and other drug misuse: the role of brief
interventions.
PMID- 10695448
TI - Controversy erupts over reuse of "single use" medical devices.
PMID- 10695450
TI - Big health insurer gives physicians final say in treatment.
PMID- 10695449
TI - Health situation in former communist bloc is dire, says Unicef.
PMID- 10695452
TI - A declaration of interdependence.
PMID- 10695451
TI - Addiction is a treatable disease, not a moral failing.
PMID- 10695453
TI - Catheter ablation of chronic atrial fibrillation targeting the reinitiating
triggers.
AB - INTRODUCTION: We assessed the mode of reinitiation of atrial fibrillation (AF)
after cardioversion and the efficacy of ablating these foci of reinitiation in
patients with chronic AF. METHODS AND RESULTS: Fifteen patients, 7 with
structural heart disease, underwent mapping and catheter ablation of drug
resistant AF documented to be persistent for 5 +/- 4 months. In all patients,
cardioversion was followed by documentation of P on T atrial ectopy and early
recurrence, which allowed mapping of the reinitiating trigger or the source of
ectopy. Radiofrequency (RF) ablation was performed at pulmonary vein (PV) ostia
using a target temperature of 50 degrees C and a power limit of 30 to 40 W, with
the endpoint being interruption of all local muscle conduction. A total of 32
arrhythmogenic PVs and 2 atrial foci (left septum and left appendage) were
identified: 1, 2, and 3 or 4 PVs in 5, 3, and 6 patients. RF applications at the
ostial perimeter resulted in progressively increasing delay, followed by
abolition of PV potentials in 8, but potentials persisted in 6. A single ablation
session was performed in 7 patients and 8 underwent two or three sessions because
of recurrence of AF; ablation was directed at the same source due to recovery of
local PV potential or at a different PV. No PV stenosis was noted either acutely
or at repeated follow-up angiograms. Nine patients (60%) were in stable sinus
rhythm without antiarrhythmic drugs at follow-up of 11 +/- 8 months.
Anticoagulants were interrupted in 7 patients. CONCLUSION: PVs are the dominant
triggers reinitiating chronic AF in this patient population. Elimination of PV
potentials by ostial RF applications results in stable sinus rhythm in 60%. A
larger group and longer follow-up are needed to investigate further the role of
trigger ablation in curative therapy for chronic AF.
PMID- 10695454
TI - Mapping and radiofrequency catheter ablation of the three types of sustained
monomorphic ventricular tachycardia in nonischemic heart disease.
AB - INTRODUCTION: Sustained monomorphic ventricular tachycardia (VT) associated with
nonischemic cardiomyopathy (CMP) is uncommon. Optimal approaches to catheter
mapping and ablation are not well characterized, but they are likely to depend on
the VT mechanism. The purpose of this study was to evaluate the mechanisms of
sustained monomorphic VT encountered in nonischemic CMP and to assess the
feasibility, safety, and efficacy of catheter radiofrequency ablation for
treatment. METHODS AND RESULTS: Twenty-six consecutive patients with nonischemic
CMP referred for management of recurrent VT were studied. In 16 (62%) patients,
VT was related to a region of abnormal electrograms consistent with scar and the
response to pacing suggested a reentrant mechanism. In 5 (19%) patients, VT was
due to bundle branch or interfascicular reentry. In 7 (27%) patients, the VT
mechanism was focal automaticity, 4 of whom had evidence of tachycardia-induced
CMP. After catheter ablation targeting parts of reentrant circuits, VT was not
inducible in 8 (53%) of 15 patients with scar-related reentry, was modified in 5
(33%) patients, and still was inducible in 2 (13%) patients. Ablation was
successful in 5 of 5 patients with bundle branch reentry and in 6 of 7 patients
with a focal automaticity mechanism. Overall, catheter ablation abolished
clinical recurrence of VT in 20 (77%) of 26 patients during a follow-up of 15 +/-
12 months. CONCLUSION: Three different mechanisms of VT are encountered in
patients with nonischemic CMP. The mapping and ablation approach varies with the
type of VT. In this selected population, the overall efficacy was 77%.
PMID- 10695455
TI - Monomorphic ventricular tachycardia in nonischemic disease: what have we learned?
PMID- 10695456
TI - Sensing lead failure in implantable defibrillators: a comparison of two commonly
used leads.
AB - INTRODUCTION: Despite major technological advances, structural problems in
implantable cardioverter defibrillator (ICD) endocardial sensing leads remain a
significant problem. There are two types of ICD sensing leads: (1) dedicated
bipolar leads and (2) integrated lead systems that include defibrillation coils.
The long-term performance of these two lead systems has not been directly
compared. METHODS AND RESULTS: We prospectively examined the incidence of lead
failure manifested by inappropriate arrhythmia detection in 247 consecutive
patients undergoing abdominal ICD implant at a single center between 1991 and
1995. A total of 107 patients received BT-10 (dedicated bipolar) leads and 140
patients received Endotak (integrated bipolar) leads. Over a mean follow-up of
860 +/- 442 days, there were 19 (17.8%) lead failures with the BT-10 lead (261 to
1,505 days postimplant) compared with only 6 (4.3%; P < 0.01) with the Endotak
lead (410 to 1,211 days postimplant). Lead failure was due to an insulation
defect in all cases, with the problem occurring in the proximal lead (within the
pulse generator pocket) in all but one case. Lead survival was significantly
better with the Endotak lead (P = 0.015, risk ratio = 3.0, 95% confidence
intervals 1.2 to 7.6). CONCLUSION: Late lead failure due to insulation defects in
BT-10 sensing leads (causing inappropriate ICD activation) is a relatively common
and progressive phenomenon, with difficulties becoming apparent as long as 4
years after implant. This problem is a likely cause of inappropriate shocks in
patients with BT-10 leads. Implantation of a new sensing lead should be
considered at the time of elective pulse generator replacement, even in the
absence of demonstrable oversensing.
PMID- 10695457
TI - Optimization of transvenous coil position for active can defibrillation
thresholds.
AB - INTRODUCTION: Lead systems that include an active pectoral pulse generator are
now standard for initial defibrillator implantations. However, the optimal
transvenous lead system and coil location for such active can configurations are
unknown. The purpose of this study was to evaluate the benefit and optimal
position of a superior vena cava (SVC) coil on defibrillation thresholds with an
active left pectoral pulse generator and right ventricular coil. METHODS AND
RESULTS: This prospective, randomized study was performed on 27 patients. Each
subject was evaluated with three lead configurations, with the order of testing
randomized. Biphasic shocks were delivered between the right ventricular coil and
an active can alone (unipolar), or an active can in common with the proximal coil
positioned either at the right atrial/SVC junction (low SVC) or in the left
subclavian vein (high SVC). Stored energies at defibrillation threshold were
higher for the single-coil, unipolar configuration (11.2 +/- 6.6 J) than for the
high (8.9 +/- 4.2 J) or low (8.5 +/- 4.2 J) SVC configurations (P < 0.01).
Moreover, 96% of subjects had low (< or = 15 J) thresholds with the SVC coil in
either position compared with 81% for the single-coil configuration. Shock
impedance (P < 0.001) was increased with the unipolar configuration, whereas peak
current was reduced (P < 0.001). CONCLUSION: The addition of a proximal
transvenous coil to an active can unipolar lead configuration reduces
defibrillation energy requirements. The position of this coil has no significant
effect on defibrillation thresholds.
PMID- 10695458
TI - Electrophysiologic characteristics of the atrium in sinus node dysfunction:
atrial refractoriness and conduction.
AB - INTRODUCTION: Clinical electrophysiology (EP) has focused attention on the EP
properties of atrial muscle in patients with atrial fibrillation (AF). Patients
with sinus node dysfunction (SND) sometimes are included in these studies, but
the characteristics of these patients with SND alone appear less well
investigated. METHODS AND RESULTS: We reviewed EP data of 46 patients (mean age
70 +/- 8 years) with SND, who underwent EP study for evaluation of the atrial
substrate. In 16 patients, a history of paroxysmal AF was documented, but not in
the remaining 30 patients who had SND alone. We considered as control a group of
25 subjects (mean age 63 +/- 14 years), who were referred to our EP laboratory
for unexplained syncope or AV conduction disturbances. Following pharmacologic
washout and at a drive cycle of 600 msec, effective (ERP) and functional
refractory periods (FRP), S1-A1 and S2-A2 latency, A1 and A2 width, latent
vulnerability index (ERP/A2), and P wave duration on the surface ECG were
measured. Intra-atrial conduction times were measured from the stimulus artifact
by pacing the high right atrium (HRA), to the corresponding atriograms at the AV
node (HRA-AVN), low lateral atrium (HRA-LLA), and low interatrial septum close to
the coronary sinus ostium (HRA-CSO). Compared with the control group, SND
patients did not show differences in ERP (238 +/- 26 msec vs 250 +/- 29 msec),
FRP (274 +/- 25 msec vs 280 +/- 32 msec), S1-A1 (38 +/- 15 msec vs 33 +/- 11
msec) and S2-A2 latency (67 +/- 24 msec vs 63 +/- 25 msec), or HRA-AVN (81 +/- 24
msec vs 65 +/- 19 msec), HRA-LLA (36 +/- 30 msec vs 40 +/- 27 msec), and HRA-CSO
(77 +/- 17 msec vs 80 +/- 15 msec) conduction times. In contrast, we observed
strong differences in atriogram durations A1 (59 +/- 19 msec vs 39 +/- 13 msec; P
< 0.001) and A2 (92 +/- 28 msec vs 57 +/- 18 msec; P < 0.001), as well as in the
latent vulnerability index ERP/A2 (2.8 +/- 1.2 msec vs 4.8 +/- 1.7; P < 0.001).
Also, the P wave was slightly longer (104 +/- 18 msec vs 94 +/- 45 msec; P <
0.05). No significant statistical difference in EP parameters was found between
SND patients with or without documented AF. CONCLUSION: In patients with SND,
atrial refractoriness appears similar to that of control subjects. The most
important EP abnormality appears to be local conduction slowing disturbances,
with prolonged basal and postextrastimuli atriograms, responsible for a lower
vulnerability index. This could explain, at least in part, the tendency of
patients with SND to develop AF during their natural history. Normality of atrial
refractoriness, in contrast to atrial conduction disorders, might explain why
atrial pacing shows a preventative effect on the development of AF and why
antiarrhythmic drugs often are ineffective.
PMID- 10695459
TI - Location of the lower turnaround point in typical AV nodal reentrant tachycardia:
a quantitative model.
AB - INTRODUCTION: Recent observations suggest that the circuit of AV nodal reentrant
tachycardia (AVNRT) may extend down to the His bundle. The purpose of this study
was to develop a quantitative model indicating the location of the lower
turnaround point in AVNRT. METHODS AND RESULTS: Slow pathway modification was
performed in 70 patients with typical AVNRT. During sinus rhythm, ventricular
pacing was performed with the AVNRT cycle length. During AVNRT, the HinitAinit
interval was measured from initial His to the initial atrial deflection recorded
in the His-bundle lead. During ventricular pacing, the HendAinit interval was
measured from end of the His to the beginning of the atrial deflection. It was
hypothesized that x reflects conduction time from the lower turnaround point to
Ainit, whereas y reflects conduction time from the lower turnaround point to
Hinit. Anterograde conduction during AVNRT and retrograde conduction during
ventricular pacing were assumed to be identical if there was 1:1 retrograde
conduction at the AVNRT cycle length. The following formulas describe the
relation of the measured parameters: x - y = HinitAinit; and x + y = HendAinit.
Resolving both formulas yields the unknown x and y: y = (HendAinit -
HinitAinit)/2, x = (HendAinit + HinitAinit)/2. These criteria were present in 52
of 70 patients. The mean cycle length of AVNRT was 355 +/- 42 msec, mean
HinitAinit was 54 +/- 27 msec, and mean HendAinit was 60 +/- 29 msec.
Accordingly, in 20 of 52 patients, the lower turnaround point was located within
the His bundle (y = -15.4 +/- 16.1 msec), in 3 of 52 it was in the nodal-His
junctional area (y = 0), and in 29 of 52 it was above the His bundle (y = +12.7
+/- 10.3 msec). The HinitAinit interval was significantly longer (66 +/- 32 msec
vs 47 +/- 20 msec; P = 0.02) and the HendAinit interval was significantly shorter
(45 +/- 30 msec vs 69 +/- 24 msec; P = 0.004) when the first group was compared
with the others. CONCLUSION: In about 1 of 3 of patients with typical AVNRT, the
lower turnaround point of the circuit is within the His bundle; in more than half
of the patients it is above the His bundle. These data do not support the concept
that all AVNRTs have an intranodal circuit, but are in accordance with the
finding of longitudinal dissociation of the His bundle.
PMID- 10695460
TI - Catheter ablation for hemodynamically unstable monomorphic ventricular
tachycardia.
AB - INTRODUCTION: Hemodynamic collapse precludes extensive catheter mapping to
identify focal target regions in many patients with ventricular tachycardia (VT)
associated with heart disease. This study tested the feasibility of catheter
ablation of poorly tolerated VTs by targeting a region identified during sinus
rhythm. METHODS AND RESULTS: Ablation was attempted in five patients, ages 44 to
59 years, with left ventricular ejection fractions of 0.15 to 0.20 and poorly
tolerated VT causing multiple implantable defibrillator therapies (6 to 30
episodes/month). VT was due to prior infarction in three patients and nonischemic
cardiomyopathy in two. Target regions were sought that met the following
criteria: (1) evidence of slow conduction from fractionated sinus rhythm
electrograms and stimulus-QRS delays during pace mapping, and (2) evidence that
the region contains the reentrant circuit exit from pace mapping. In 4 of 5
patients, a target region was identified and radiofrequency lesions applied.
Ablation abolished all recurrences of VT in 3 of 4 patients during follow-up of
14 to 22 months. There were no complications. CONCLUSION: Ablation of poorly
tolerated VT is feasible in some patients by mapping during sinus rhythm and
performing ablation over a region of identifiable scar that contains abnormal
conduction and a presumptive VT exit.
PMID- 10695461
TI - Ventricular tachycardias mimicking those arising from the right ventricular
outflow tract.
AB - INTRODUCTION: Ablation of ventricular tachycardia (VT) arising from the right
ventricular outflow tract (RVOT) has proven highly successful, yet VTs with
similar ECG features may originate outside the RVOT. METHODS AND RESULTS: We
reviewed the clinical, echocardiographic, and ECG findings of 29 consecutive
patients referred for ablation of monomorphic VT having a left bundle branch
block pattern in lead V1 and tall monophasic R waves inferiorly. Nineteen
patients (group A) had VTs ablated from the RVOT, and 10 patients (group B) had
VTs that could not be ablated from the RVOT. The QRS morphology during VT or
frequent ventricular premature complexes was the only variable that distinguished
the two groups. During the target arrhythmia, ECGs of group B patients displayed
earlier precordial transition zones (median V3 vs V5; P < 0.001), more rightward
axes (90 +/- 4 vs 83 +/- 5; P = 0.002), taller R waves inferiorly (aVF: 1.9 +/-
1.0 vs 2.4 +/- 0.5; P = 0.020) and small R waves in lead V1 (10/10 vs 9/19; P =
0.011). Radiofrequency catheter ablation from the RVOT failed to eliminate VT in
any group B patient, but ablation from the left ventricular outflow tract (LVOT)
eliminated VT in 2 of 6 patients in whom left ventricular ablation was attempted.
CONCLUSION: The absence of an R wave in lead V1 and a late precordial transition
zone suggest an RVOT origin of VT, whereas an early precordial transition zone
characterizes VTs that mimic an RVOT origin. The latter VTs occasionally can be
ablated from the LVOT. Recognition of these ECG features may help the physician
advise patients and direct one's approach to ablation.
PMID- 10695462
TI - Augmentation of QRS wave amplitudes in the precordial leads during narrow QRS
tachycardia.
AB - INTRODUCTION: QRS morphology during narrow QRS supraventricular tachycardia in
patients without ventricular preexcitation generally is considered the same as
that seen during sinus rhythm. This study presents a new ECG observation that the
QRS amplitude increased significantly in leads V2 through V5 during tachycardia.
METHODS AND RESULTS: Using the same ECG machine and the same electrode patches
applied to the same electrode positions, 12-lead ECGs during sinus rhythm and
narrow QRS tachycardia were analyzed comparatively in 23 patients without
ventricular preexcitation. Precordial QRS amplitudes were measured as the
vertical distance from the peak of the R to the nadir of the S wave. The
amplitudes also were measured during atrial rapid pacing and extrastimulation.
Furthermore, ventricular excitation during sinus rhythm and tachycardia was
studied using body surface mapping. Body surface distributions of QRS potentials
and ventricular activation time (VAT) were displayed as maps. Gross area of QRS
(AQRS, equivalent to the QRS amplitude) was compared during sinus rhythm versus
tachycardia. During tachycardia, QRS amplitude significantly increased in leads
V2 through V5, without any noticeable change in the transitional zone or QRS wave
duration. Increase of QRS amplitude also was noted during atrial rapid pacing and
extrastimulation. Gross AQRS values during tachycardia significantly increased in
the left parasternal area, whereas QRS isopotential and VAT isochronal maps were
similar during sinus rhythm and tachycardia, suggesting a minimal role of
conduction delay in the increase of QRS amplitude. CONCLUSION: QRS wave amplitude
significantly increased in leads V2 through V5 during narrow QRS tachycardia
compared with QRS waves in sinus rhythm. Increase of QRS amplitude seemed
unlikely due to a conduction delay within the ventricular myocardium.
PMID- 10695463
TI - Effect of heart rate on QRS voltage: a simple relation that escaped notice.
PMID- 10695464
TI - Transvenous parasympathetic nerve stimulation in the inferior vena cava and
atrioventricular conduction.
AB - INTRODUCTION: In previous reports, we demonstrated a technique for
parasympathetic nerve stimulation (PNS) within the superior vena cava, pulmonary
artery, and coronary sinus to control rapid ventricular rates during atrial
fibrillation (AF). In this report, we describe another vascular site, the
inferior vena cava (IVC), at which negative dromotropic effects during AF could
consistently be obtained. Moreover, stimulation at this site also induced dual AV
nodal electrophysiology. METHODS AND RESULTS: PNS was performed in ten dogs using
rectangular stimuli (0.1 msec/20 Hz) delivered through a catheter with an
expandable electrode basket at its tip. Within 3 minutes and without using
fluoroscopy, the catheter was positioned at an effective PNS site in the IVC at
the junction of the right atrium. AF was induced and maintained by rapid atrial
pacing. During stepwise increase of the PNS voltage from 2 to 34 V, a graded
response of ventricular rate slowing during AF was observed (266 +/- 79 msec
without PNS vs 1,539 +/- 2,460 msec with PNS at 34 V; P = 0.005 by analysis of
variance), which was abolished by atropine and blunted by hexamethonium. In three
animals, PNS was performed during sinus rhythm. Dual AV nodal electrophysiology
was present in 1 of 3 dogs in control, whereas with PNS, dual AV nodal
electrophysiology was observed in all three dogs. PNS did not significantly
change sinus rate or arterial blood pressure during ventricular pacing.
CONCLUSION: Stable and consistent transvenous electrical stimulation of
parasympathetic nerves innervating the AV node can be achieved in the IVC, a
transvenous site that is rapidly and readily accessible. The proposed catheter
approach for PNS can be used to control ventricular rate during AF in this animal
model.
PMID- 10695465
TI - Ionic basis for action potential prolongation by phenylephrine in canine
epicardial myocytes.
AB - INTRODUCTION: In canine ventricle, alpha-adrenergic agonists prolong action
potential duration (APD) without any effect on the action potential notch,
suggesting that, in this species, the effect on repolarization might be
independent of inhibition of I(to). The present study investigated the action of
the alpha-adrenergic agonist phenylephrine on the action potential and the
repolarizing currents I(to) and I(K) in isolated canine epicardial myocytes.
METHODS AND RESULTS: Isolated cells from canine epicardial tissue, and Purkinje
fibers, were studied with the whole cell, voltage clamp method. Phenylephrine 0.1
microM increased APD by 13% +/- 4% at 90% repolarization without affecting the
notch or amplitude. Under voltage clamp, concentrations of phenylephrine as high
as 10 microM had no effect on I(to) in canine epicardial myocytes. However, I(to)
of isolated canine Purkinje myocytes was reduced to 69% +/- 7% of control by 1
microM phenylephrine. Further studies in canine epicardial myocytes revealed an
action of phenylephrine to inhibit I(K), and in particular I(Ks). Using a voltage
protocol that included a two-step repolarization to separate I(Ks) and I(Kr) tail
components, the largely I(Kr) component was not significantly affected by 1
microM phenylephrine, whereas the largely I(Ks) component was reduced to 81% +/-
5% of control value. CONCLUSION: Alpha-adrenergic prolongation of repolarization
in canine epicardium does not result from inhibition of I(to). Rather, it appears
that reduction of I(Ks) contributes to the action of phenylephrine. The
unresponsiveness of epicardial I(to) is not a general characteristic of the
canine heart, because Purkinje myocyte I(to) was inhibited, suggesting regional
differences in the molecular basis of I(to) and/or alpha-adrenergic signaling in
the canine heart.
PMID- 10695466
TI - Effect of atrial radiofrequency ablation designed to cure atrial fibrillation on
atrial mechanical function.
AB - INTRODUCTION: The effects of linear radiofrequency lesions in the atria for cure
of atrial fibrillation on atrial contraction have not previously been quantified.
METHODS AND RESULTS: Atrial function was measured before and 30 +/- 24 days after
a biatrial ablation procedure designed to cure atrial fibrillation in eight dogs
and after a sham procedure in three dogs. Atrial mechanical function was assessed
using Doppler diastolic blood flow velocities, atrial systolic pressure wave
amplitude, and assessment of atrial contribution to cardiac output estimated by
comparison of AV sequential pacing to ventricular pacing at the same heart rate.
The mitral Doppler A/E velocity ratio was 1.03 +/- 0.45 before and 0.72 +/- 0.43
after ablation (P = 0.048). The tricuspid A/E ratio was 0.88 +/- 0.17 before and
0.71 +/- 0.12 after ablation (P = 0.04). The estimated atrial contribution to
cardiac output was 18% +/- 9% before and 5% +/- 4% after ablation (P < 0.01). The
left atrial systolic pressure wave amplitude was 2.8 +/- 1.5 mmHg before and 1.7
+/- 1.0 mmHg after ablation (P = 0.1). These changes were not observed in control
dogs. Lesions covered 25% +/- 6% of the atrial endocardial surface. CONCLUSION:
Multiple linear radiofrequency lesions in the atria designed to cure atrial
fibrillation may impair atrial contractility. Reduced atrial function is partly
due to loss of atrial myocardial mass, but regional delays in atrial activation
and splinting of the atria by scarring also may contribute.
PMID- 10695467
TI - How constant anatomically is the tendon of Todaro as a marker for the triangle of
Koch?
AB - INTRODUCTION: Although well recognized by anatomists as a border of the triangle
of Koch demarcating the location of the AV node, the tendon of Todaro is not
visible in the operating room or in the catheterization laboratory. Instead,
clinicians use as surrogate a projected line between the eustachian valve and the
central fibrous body. The constancy of the tendon of Todaro within this border
remains to be determined. MATERIALS AND RESULTS: We reexamined serial histologic
sections from 25 adults and 50 infants and gross dissections in four normal
hearts. The tendon of Todaro was identified in all cases and traced to the
central fibrous body in all but one case. It tended to be thicker in the hearts
of infants cases (0.2 to 0.8 mm vs 0.1 to 0.6 mm). The tendon and the hinge-line
of the septal leaflet of the tricuspid valve were consistent as landmarks for
location of the compact AV node in all the cases studied by histology. Gross
dissections traced the tendon to the free edge of the eustachian valve.
CONCLUSION: The tendon of Todaro is present in hearts obtained from both adults
and infants. It, or its surrogate, is a reliable border for the triangle of Koch
and serves as a landmark to location of the atrial components of the AV
conduction axis.
PMID- 10695468
TI - Right atrial flutter isthmus revisited: normal anatomy favors nonuniform
anisotropic conduction.
AB - INTRODUCTION: The "flutter isthmus," the part of the lower right atrium between
the eustachian valve and the tricuspid annulus inferior to the coronary sinus os,
is considered the crucial zone for conduction delay necessary for the genesis of
atrial flutter. However, the underlying mechanism remains unclear. METHODS AND
RESULTS: We studied the "flutter isthmus" in 50 hearts obtained at autopsy from
patients without atrial tachyarrhythmias. The muscular trabecular arrangement was
dissected carefully by peeling off the endocardium. Documentation of the
trabecular arrangement focused, in particular, on the question of whether there
was a uniform pattern of well-aligned muscle trabeculae or a nonuniform
architecture. It appeared that a nonuniform trabecular pattern prevailed (37/50
[74%]). In these hearts, the muscular arrangement showed abundant cross-overs and
interlacing trabeculae, particularly in the zone immediately inferior to the
coronary sinus os. Connections also occurred along the inferior rim of the os.
CONCLUSION: The normal anatomy of the lower right atrium favors nonuniform
muscular trabeculation, with interlacing bundles and a multitude of cross-overs.
The potential for conduction delay is present in the vast majority of normal
hearts. This raises the question as to what has changed in the hearts of patients
with atrial flutter such that the potential for conduction delay and reentry has
become effective.
PMID- 10695469
TI - Ventricular fibrillation in a patient with prominent J (Osborn) waves and ST
segment elevation in the inferior electrocardiographic leads: a Brugada syndrome
variant?
AB - Recurrent ventricular fibrillation was observed in a 29-year-old Vietnamese man
who did not exhibit structural heart disease. The patient's ECG showed prominent
J (Osborn) waves and ST segment elevation in the inferior leads that were not
associated with hypothermia, serum electrolyte disturbance, or myocardial
ischemia. Rate-dependent change in the amplitude of J waves and ST segment
elevation also were observed. An implantable cardioverter defibrillator (ICD) was
implanted. Adjunctive treatment with amiodarone reduced J wave amplitude,
preventing ventricular fibrillation and ICD shocks. Prominent J waves and ST
segment elevation in the inferior leads may serve as an important diagnostic sign
to detect high-risk individuals with a history of unexplained syncope. ICD
implantation plus amiodarone is the treatment of choice.
PMID- 10695470
TI - An innovative application of anatomic electromagnetic voltage mapping in a
patient with Ebstein's anomaly undergoing permanent pacemaker implantation.
AB - A novel application of the Biosense CARTO System anatomic electromagnetic voltage
mapping is presented, utilized as a guide for permanent pacemaker placement. The
technique is illustrated in the successful implantation of an atrial lead in a
patient with Ebstein's anomaly characterized by a severely dilated right atrium
and extremely low-amplitude voltage signals, requiring a DDD pacemaker.
Electromagnetic voltage mapping can be used in selected patients with structural
heart disease to determine the optimal site for permanent pacemaker lead
placement.
PMID- 10695471
TI - Ablation of ventricular tachycardia by isolating the critical site in a patient
with arrhythmogenic right ventricular cardiomyopathy.
AB - We describe a patient with arrhythmogenic right ventricular cardiomyopathy in
whom ventricular tachycardia (VT) was ablated by isolating a relatively large
area of the critical site using catheter ablation. Endocardial mapping showed
abnormal fragmented electrograms with delayed potential (DP) from an entire area
of the aneurysm. Pace mappings from the aneurysm produced a QRS morphology
identical to that of clinical VT. After catheter ablation was performed at the
exit site of the VT critical area, programmed stimulation inside the aneurysm
captured the DP but not the QRS complexes. These data suggest that VT can be
ablated successfully by isolation of the critical area.
PMID- 10695472
TI - Arrhythmias in heart failure: current concepts of mechanisms and therapy.
AB - About one half of deaths in patients with heart failure are sudden, mostly due to
ventricular tachycardia (VT) degenerating to ventricular fibrillation or
immediate ventricular fibrillation. In severe heart failure, sudden cardiac death
also may occur due to bradyarrhythmias. Other dysrhythmias complicating heart
failure include atrial and ventricular extrasystoles, atrial fibrillation (AF),
and sustained and nonsustained ventricular tachyarrhythmias. The exact mechanism
of the increased vulnerability to arrhythmias is not known. Depending on the
etiology of heart failure, different preconditions, including ischemia or
structural alterations such as fibrosis or myocardial scarring, may be prominent.
Reentrant mechanisms around scar tissue, afterdepolarizations, and triggered
activity due to changes in calcium metabolism significantly contribute to
arrhythmogenesis. Furthermore, alterations in potassium currents leading to
action potential prolongation and an increase in dispersion of repolarization
play a significant role. Treatment of arrhythmias is necessary either because
patients are symptomatic or to reduce the risk for sudden cardiac death. The
individual history, left ventricular function, electrophysiologic testing, and
the signal-averaged ECG give useful information for identifying patients at risk
for sudden cardiac death. The implantable cardioverter defibrillator (ICD) has
evolved as a promising therapy for life-threatening arrhythmias. A potential role
may exist for antiarrhythmic drugs, mainly amiodarone. There is growing evidence
that patients with sustained VT or a history of resuscitation have the best
outcome with ICD therapy regardless of the degree of heart failure. Many of these
patients require additional antiarrhythmic therapy because of AF or nonsustained
VTs that may activate the device. Catheter ablation or map-guided endocardial
resection are additional options in selected patients but seldom represent the
only therapeutic strategy.
PMID- 10695473
TI - Gap junctions as active signaling molecules for synchronous cardiac function.
PMID- 10695474
TI - Short ventriculoatrial intervals during orthodromic atrioventricular
reciprocating tachycardia: what is the mechanism?
PMID- 10695475
TI - Termination of ventricular tachycardia by a nonpropagated extrastimulus.
PMID- 10695476
TI - Plaque rupture and plaque erosion.
AB - There are multiple substrates for coronary thrombosis overlying an
atherosclerotic plaque. The most common, plaque rupture, consists of an
interruption of a thin fibrous cap overlying a lipid rich core. Plaque rupture is
a result of macrophage infiltration and matrix degradation, is often seen in
calcified plaques, and is highly associated with hypercholesterolemia. A less
common substrate, plaque erosion, is not associated with elevated cholesterol and
is the prime cause of coronary thrombosis in premenopausal women. The
characteristic histologic features are abundant surface smooth muscle cells and
proteoglycans, and a small or absent lipid rich core. The mechanisms of plaque
erosion are unclear, and there are no consistent risk factors, although patients
are often smokers.
PMID- 10695477
TI - A role of plasminogen in atherosclerosis and restenosis models in mice.
AB - In addition to its preeminent role in fibrinolysis, the plasminogen system is
believed to play a key role in mediating cell migration. Leukocyte migration into
the vessel wall is a key and early event in the development of the lesions of
atherosclerosis and restenosis, pathologies which may be viewed as specific
examples of vascular inflammatory responses. The development of mice in which the
plasminogen gene has been inactivated affords an opportunity to test the
contribution of plasminogen in leukocyte migration during in vivo. This article
summarizes recent studies conducted in murine models of the inflammatory
response, restenosis and atherosclerosis in which leukocyte migration, and in
particular monocyte/macrophage migration, has been evaluated in plasminogen
deficient mice. Recruitment of these cells through the vessel wall in
inflammatory response models and into the vessel wall in restenosis and
transplant atherosclerosis models is substantially blunted. These data implicate
plasminogen in the migration of leukocytes in these murine models. With the
numerous correlations between components and/or activation of the plasminogen
system in restenosis and atherosclerosis, these results also support a role of
plasminogen in the corresponding human pathologies.
PMID- 10695478
TI - Coronary artery disease and fibrinolysis: from the blood to the vessel wall.
AB - This review addresses a continuum of the role of derangements in the fibrinolytic
system from the blood to the vessel wall in the pathogenesis of acute coronary
events and the underlying vasculopathy. Pharmacologic modification of
fibrinolysis has become a primary therapy for acute myocardial infarction caused
by thrombotic occlusion of infarct-related coronary arteries. Patients with type
2 diabetes and other insulin resistant states exhibit impaired fibrinolysis in
blood, implicated in the pathogenesis of macroangiopathy. An altered balance of
activity of proteins involved in the fibrinolytic system within vessel walls (the
proteo[fibrino]lytic system) has been recognized as well and appears likely to
contribute to the acceleration of macroangiopathy. Accordingly, normalization of
the proteo(fibrino)lytic system in blood and in vessel walls is a particularly
attractive target for retardation of the progression of macrovascular disease
associated with insulin resistant states.
PMID- 10695479
TI - Plasminogen activator inhibitor type-1 (PAI-1) and its role in cardiovascular
disease.
AB - Cardiovascular disease is responsible for approximately 50% of total mortality in
Europe, the USA and Japan. Established risk factors including smoking,
hypercholesterolemia, and hypertension explain about half of the incidence of
cardiovascular disease only. Reduced endogenous fibrinolytic activity secondary
to increased plasma activity of plasminogen activator inhibitor type-1 (PAI-1) is
now considered as a new cardiovascular risk factor. In this review, evidence is
gathered for the notion that PAI-1 constitutes a predictor of cardiovascular
disease and also contributes to the development of cardiovascular disease as a
pathogenetic factor. The review will focus on experimental studies modulating PAI
1 activity and clinical studies addressing coronary heart disease, myocardial
infarction, restenosis after coronary angioplasty, and graft occlusion after
coronary artery bypass grafting.
PMID- 10695480
TI - Structure and function of the urokinase receptor.
AB - The binding of the urokinase plasminogen activator (uPA) to its receptor (uPAR)
regulates cell adhesion, surface proteolysis, chemotaxis and cell extravasation
in a number of experimental systems. Recent evidences have suggested that uPAR
can by itself mediate chemotaxis of human monocytes and cause profound changes in
cytoskeletal organization indicating that this receptor has the properties of a
cell-surface regulated chemokine. Indeed, it is likely that upon binding to uPA,
uPAR undergoes a conformational change that uncovers a new epitope located in the
linker region between domain 1 and 2 of the receptor and is endowed with a potent
chemotactic activity. This conformational change can be mimicked in vitro by
enzymatic processing of a recombinant receptor. We have shown that chymotrypsin
cleaves uPAR between domain 1 and 2 in an area that can be also cleaved by uPA at
high efficiency and generate a receptor that can mediate monocytes migration
independently of uPA binding. This mechanism is pertussis-toxin sensitive and
involves activation of tyrosine kinases and cytoskeletal reorganization events in
vitro. These studies indicate that in addition to its receptor function, upon
binding to uPA, uPAR becomes a pleiotropic ligand for other still to be
identified surface molecules.
PMID- 10695481
TI - Control of smooth muscle cell proliferation--the role of the basement membrane.
AB - In atherogenesis and in response to vessel injury, arterial smooth muscle cells
(SMCs) are activated from a quiescent, differentiated state into an actively
proliferating and synthetic phenotype which migrate into the intima where the
cells participate in the formation of a fibrous plaque or intimal hyperplasia.
The mechanisms involved in the control of SMC function are not clear and no
preventive therapy against SMC activation is available. Interactions between SMCs
and the extracellular matrix have been shown to influence SMC structure and
function through integrin-mediated signaling processes. The SMC basement membrane
is a specific form of extracellular matrix which seems to be crucial for the
maintenance of SMC quiescence and the disruption of these interactions is part of
cellular activation after atherogenic or traumatic stimuli. This concept of
"negative growth control" may constitute a future target for the development of
new strategies in the prevention of SMC activation in atherogenesis and
restenosis formation.
PMID- 10695482
TI - Gene regulation and arteriosclerosis: are developmental programs reactivated in
vascular disease?
AB - The molecular mechanisms regulating the development of vascular diseases such as
atherosclerosis remain poorly understood at present. Similarities between genetic
programs observed during the course of vascular disease with those observed
during vascular development suggest that developmental processes are
recapitulated in vascular disease. The earliest event in vascular development is
the differentiation of endothelial cells from their mesodermally-derived
hemangioblastic precursors. The receptor for vascular endothelial growth factor,
KDR/flk-1, plays a critical role in these earliest stages of vascular
development. During development and in the adult, expression of this receptor is
restricted to vascular endothelial cells and their immediate precursors. We have
therefore endeavored to determine the transcriptional events regulating KDR/flk-1
expression, with the hope of gaining insight into processes of vascular
development that might also be important in vascular diseases of the adult.
PMID- 10695483
TI - Oxidative stress and atherosclerosis: its relationship to growth factors,
thrombus formation and therapeutic approaches.
AB - The initiating event of atherogenesis is thought to be an injury to the vessel
wall resulting in endothelial dysfunction. This is followed by key features of
atherosclerotic plaque formation such as inflammatory responses, cell
proliferation and remodeling of the vasculature, finally leading to vascular
lesion formation, plaque rupture, thrombosis and tissue infarction. A causative
relationship exists between these events and oxidative stress in the vessel wall.
Besides leukocytes, vascular cells are a potent source of oxygen-derived free
radicals. Oxidants exert mitogenic effects that are partially mediated through
generation of growth factors. Mitogens, on the other hand, are potent stimulators
of oxidant generation, indicating a putative self-perpetuating mechanism of
atherogenesis. Oxidants influence the balance of the coagulation system towards
platelet aggregation and thrombus formation. Therapeutic approaches by means of
antioxidants are promising in both experimental and clinical designs. However,
additional clinical trials are necessary to assess the role of antioxidants in
cardiovascular disease.
PMID- 10695484
TI - Soluble vascular cell adhesion molecule-1 (VCAM-1) as potential marker of
atherosclerosis.
AB - An increasing number of descriptive reports on soluble adhesion molecules and
association with various diseases are published. Throughout these reports soluble
adhesion molecules are identified as markers of inflammation. Since
atherosclerosis demonstrates features of a chronic inflammatory disease, a
potential association of soluble adhesion molecules with atherosclerosis has been
postulated. However, conflicting results have been reported. One reason for this
might be the differing definitions of atherosclerosis and patient groups. Besides
the definition of atherosclerosis based on clinical symptoms, few reports use a
direct quantification of atherosclerosis in their search for a marker of
atherosclerosis. In those reports that quantify atherosclerosis, sVCAM-1 seems to
be more specific for atherosclerosis than other markers. The serum level of sVCAM
1 appears to correlate with the extent of atherosclerosis and might allow for the
detection of early stages of atherosclerosis. Large scale prospective studies
will have to prove that sVCAM-1 can be used as a diagnostic tool for the
detection of early stages of asymptomatic atherosclerosis and whether an early
therapeutic intervention based on this approach is able to prevent progression
and manifestation of the clinical sequelae of atherosclerosis.
PMID- 10695485
TI - Angiogenesis in ischemic disease.
AB - Angiogenic growth factors and their endothelial receptors function as major
regulators of blood vessel formation. The VEGF/VEGFR and the Angiopoietin/Tie2
receptor systems represent key signal transduction pathways involved in the
regulation of embryonic vascular development. Inactivation of any of the genes
encoding these molecules results in defective vascular development and lethality
between embryonic day 8.5 and 12.5. In addition, VEGF and its receptors are also
critically involved in the regulation of pathological blood vessel growth in the
adult during various angiogenesis-dependent diseases that are associated with
tissue hypoxia, such as solid tumor growth and ischemic diseases. It is now well
established that therapeutic angiogenesis can be achieved in animal models of
hind limb and myocardial ischemia by exogenously adding VEGF and/or other
angiogenic growth factors. Available clinical data from human trials also
suggests that patients with severe cardiovascular diseases could potentially
benefit from such therapies. However, much more work needs to be done to compare
the potency of different angiogenic factors or the combination thereof, as well
as the best way of delivery, either as recombinant proteins, as naked DNA or via
adenoviral vectors. Nevertheless, the therapeutic efficacy of simply injecting
naked plasmid DNA or proteins into ischemic tissue to deliver secreted angiogenic
factors is an encouraging finding. Time will show whether the adverse side
effects of therapeutic angiogenesis, mainly vascular permeability and edema
formation, can be minimized and angiogenic factors can be used as an effective
therapy in patients for the treatment of ischemic diseases such as arterial
occlusive disease, myocardial infarction, and, eventually, also stroke.
PMID- 10695486
TI - Unstable angina in 1998.
AB - Unstable angina (UA) and non-Q-wave myocardial infarction (NQWMI) are acute
coronary syndromes with repeated, severe ischemic events of short duration. These
events are mainly due to a rapid decrease in coronary blood flow, and to a rapid,
reversible reduction of the arterial lumen in localized areas. Episodes often are
a mixture of thrombus formation due to platelet aggregation and localized spasm,
leading to vasoconstriction. Due to the short interval (minutes) of ischemic
events, usually no or minimal irreversible myocardial damage takes place. The
main goal of treatment is to prevent progression of this unstable situation into
a myocardial infarction. In the majority of cases, this is possible with adequate
treatment of vasodilatory substances like nitrates, long-acting dihydropyridines
like amlodipine and betablockers. In addition heparin and particular
antiaggregatory drugs inhibiting platelet activation by blocking the GPIIb/IIIa
receptor, the common pathway for platelet aggregation, are applied to prevent
thrombus formation. This, in the majority of cases allows a passivation of the
acute situation, leaving time to undertake possible further steps as coronary
angiography, eventually followed by PTCA of the culprit lesion or, in advanced
cases of CAD, by CABG with complete revascularization.
PMID- 10695487
TI - Lipid lowering therapy and stabilization of atherosclerotic plaques.
AB - Lipid-lowering therapy leads to a great reduction of cardiovascular
complications, but has almost no effect on the degree of stenosis of coronary
arteries. These and other studies have lead to a new paradigm of coronary artery
disease, i. e. clinical prognosis is not only determined by the extent of a
single stenosis, but mainly by the number and structure of atherosclerotic
plaques. Rupture of an instable or vulnerable plaque, characterized by a large
lipid-rich central core, inflammatory cells, and a thin fibrous cap, causes
sudden thrombus formation and thereby acute coronary syndromes. There is
accumulating evidence that cholesterol lowering can result in plaque
stabilization and improvement of endothelial dysfunction.
PMID- 10695488
TI - Acute myocardial infarction: selection of reperfusion strategies in the
individual patient.
AB - The selection of the reperfusion therapy (thrombolysis, PTCA, or no reperfusion)
in acute myocardial infarction should depend on the risk-benefit ratio, the
availability, and the costs. Thrombolysis is available everywhere and is the
standard of reperfusion therapy, but carries the risk of intracranial
haemorrhage. PTCA is more effective with less risk, but it is also more expensive
and available only in specialised centres. In current clinical practise in
Germany, the only important determinant for using PTCA as a reperfusion strategy
is the availability of a catheter laboratory. Besides availability, the selection
of reperfusion therapy should be made more on clinical relevance: (i) PTCA
especially in patients with a large benefit, the presence of contraindications to
thrombolysis, or in cardiogenic shock, and (ii) thrombolysis, if PTCA is not
immediately available.
PMID- 10695489
TI - Vectorcardiography: a tool for non-invasive detection of reperfusion and
reocclusion?
AB - In acute myocardial infarction, the perfusion status frequently fluctuates with
rapid occurrences of coronary occlusion followed by myocardial ischemia. In
patients with unstable angina, most episodes of ischemia are not accompanied by
chest pain. In these patients it is important to be able to monitor the results
of medical treatment non-invasively to establish the need for further
intervention. It is not feasible to perform coronary angiography in all patients
with acute myocardial infarction to evaluate patency of the infarct-related
artery. Furthermore, even in a patent artery, no reflow may be present in the
myocardial tissue. Angiography is therefore not the perfect golden standard to
compare noninvasive ischemia monitoring with. Prognosis seems to be a better
standard for comparison. This review indicates that vectorcardiography monitoring
may identify myocardial reperfusion at an early stage and gives valuable
prognostic information both in patients with unstable angina and acute myocardial
infarction with low interobserver variability.
PMID- 10695490
TI - Preinfarction angina and improved reperfusion of the infarct-related artery.
AB - Preinfarction angina and early reperfusion of the infarct-related artery are
major determinants of reduced infarct-size in patients with acute myocardial
infarction. The beneficial effects of preinfarction angina on infarct size have
been attributed to the development of collateral vessels and/or to post-ischemic
myocardial protection. However, recently, a relation has been found between
prodromal angina, faster coronary recanalization, and smaller infarcts in
patients treated with rt-PA: those with preinfarction angina showed earlier
reperfusion (p = 0.006) and a 50% reduction of CKMB-estimated infarct-size (p =
0.009) compared to patients without preinfarction angina. This intriguing
observation is consistent with a subsequent observation of higher coronary
recanalization rates following thrombolysis in patients with prodromal
preinfarction angina compared to patients without antecedent angina. Recent
findings in dogs show an enhanced spontaneous lysis of platelet-rich coronary
thrombi with ischemic preconditioning, which is prevented by adenosine blockade,
suggesting an antithrombotic effect of ischemic metabolites. Understanding the
mechanisms responsible for earlier and enhanced coronary recanalization in
patients with preinfarction angina may open the way to new reperfusion
strategies.
PMID- 10695491
TI - Ventricular remodeling after acute myocardial infarction.
AB - The term ventricular remodeling has been coined to describe the geometrical
changes in size and shape of the left ventricle occurring after large myocardial
infarcts. We do not exactly know what initiates this process. Slipping of
myofilaments following destruction of connective tissue--probably due to
metalloproteinase activation--could be the initial event. As a consequence, wall
stress is increased triggering deleterious adaptation processes, such as: -
intracardiac angiotensin II generation; - cardiac endothelin formation and
release; - pro-apoptotic signals for cardiomyocytes; - hypertrophic signals for
fibroblasts and cardiomyocytes. This cascade of events is not only observed in
the process of remodeling following myocardial infarction but is also operating
during the progression of heart failure. Therapeutic principles therefore are
similar in both conditions: - reduction of wall stress (pharmacological or
mechanical unloading of the heart); - blockade of angiotensin II generation or of
AT1-receptors (ACE-inhibitors or AT1 antagonists); - blockade of endothelin
receptors (ET(A)-blockers); - blockade of adrenergic receptors (preferably beta1
adrenergic receptor blockers). Better understanding of the molecular mechanisms
of the remodeling process already has fueled the search for new therapeutic
interventions (such as endothelin receptor blockers, aldosterone antagonists and
growth hormone application). Continuous research in this field may be especially
rewarding if we will succeed in identifying the very first step in the cascade.
PMID- 10695492
TI - Activation markers of coagulation and fibrinolysis: alterations and predictive
value in acute coronary syndromes.
AB - Several alterations of the coagulation, of the fibrinolysis and of inflammation
are known in patients with acute coronary syndromes. To extent current knowledge
of the pathophysiology and to optimize therapeutical strategies, the new
molecular markers can be used in clinical studies. Furthermore, several studies
were undertaken to assess the prognostic value of activation markers of these
systems for patients with unstable angina pectoris and acute myocardial
infarction with or without thrombolytic therapy. The majority of studies focussed
on markers of thrombin activation, fibrinogen, fibrin degradation products and t
PA and its main inhibitor PAI-1. While there are stimulating results from larger
studies, the value for prognosis for the individual patient still is limited by
the overlap of patients with good versus a poor outcome.
PMID- 10695493
TI - Fibrinolytic response to venous occlusion compared to physical stress test in
young patients with coronary artery disease.
AB - INTRODUCTION: Venous occlusion (VO) and exercise stress (ES) are stimulators of
the fibrinolytic system. Aim of this study was to answer which of both
stimulation tests is more useful in patients with symptom-limited coronary artery
disease (CAD) to evaluate possible defects in the fibrinolytic system. METHODS
AND RESULTS: We investigated 20 patients (M/F = 15/5; mean age = 36.7 years) with
angiographically proven CAD for their plasma levels of tissue-type plasminogen
activator (t-PA) and plasminogen activator inhibitor-type-1 (PAI-1) at basal
conditions as well as after VO and at maximal ES (standardised bicycle stress
test) and compared the data to those obtained from 12 sex- and age-matched
healthy controls (M/F = 9/3; mean age = 40.4 years). At basal conditions mean t
PA activity and t-PA antigen plasma levels were within the normal range and
comparable between the two study groups. After both VO and maximal ES, mean t-PA
activity and t-PA antigen levels increased significantly more in the control
group as compared to the CAD group. Mean PAI-1 activity plasma levels were
significantly higher in the CAD group at basal conditions before VO (patients 7.0
+/- 3.1; controls 3.9 +/- 3.9; IU/ml; p = 0.025) as well as before ES (patients
8.1 +/- 3.5; controls 4.3 +/- 3.8; IU/ml; p = 0.009). PAI-1 activity plasma
levels showed a significant decrease for patients and controls only after VO,
while PAI-1 activity was not significantly decreased in both study groups at
maximal ES. DISCUSSION: The significantly higher increase in mean plasma levels
of t-PA activity and t-PA antigen after VO compared to ES in both groups might be
explained by the fact that CAD induced symptoms in the patients during ES thus
permitting only 80% of their age, sex, and body mass index related optimal work
load. CONCLUSION: VO and ES are applicable triggers of the endogenous
fibrinolytic system in healthy subjects and patients who are not limited in their
physical exercise. Standardised VO appears to be superior to ES as stimulation
test of the endogenous fibrinolytic system in patients with symptomatic CAD.
PMID- 10695494
TI - Treatment of ischaemic stroke.
AB - Stroke is a neurological emergency that requires rapid diagnostic workup and
immediate treatment. Basic medical management such as maintenance of a high level
of systemic blood pressure, provision of an optimal supply of oxygen, and
correction of hyperthermia, hyperglycaemia and hypovolemia can contribute to a
more favourable clinical outcome of stroke patients. Neuroprotective drugs have
shown to be effective in reducing cerebral infarct size in several animal species
but their clinical benefit in stroke patients remains to be proven. Neither
heparin nor aspirin can improve neurological outcome or significantly reduce
death or dependency several months after the ischaemic event, but aspirin is
clearly effective in reducing early death or stroke recurrence within the first
few weeks. Early anticoagulation should be used for patients at high risk for
recurrent cardioembolic stroke and with carotid or vertebral artery dissection,
although this recommendation is not based on the results of randomised controlled
trials.
PMID- 10695495
TI - Hemorrhagic transformation of cerebral infarction--possible mechanisms.
AB - To analyse the risk/benefit of cerebral thrombolysis the role of hemorrhagic
transformation, either as clinically silent hemorrhagic infarction or disastrous
parenchymal hemorrhage, is crucial. Thrombolysis in acute ischemic stroke
increases the risk of severe, life-threatening hemorrhagic complications by up to
10 times compared to controls. In this paper, previous proposed concepts for the
development of intracerebral hemorrhage and hemorrhagic transformation are
presented. The role of the cerebral microvasculature will be emphasized. In
experimental focal cerebral ischemia a significant loss of basal lamina
components of the cerebral microvessels has been demonstrated. This loss in
vessel wall integrity is associated with the development of petechial hemorrhage.
The mechanisms for this microvascular damage may include plasmin-generated
laminin degradation, matrix metalloproteinases activation, transmigration of
leukocytes through the vessel wall, and other processes. We propose that
attenuation of the microvascular integrity loss with subsequent reduction in
hemorrhage is theoretically possible 1) by an improvement in the definition of an
individual time window of therapy (by means of imaging techniques), 2) by a
biochemical quantification of the basal lamina damage to avoid dangerous
interventions, and 3) by pharmacological strategies to protect the basal lamina
during thrombolysis.
PMID- 10695496
TI - Secondary prevention of stroke.
AB - Stroke is a common disorder and a leading cause of disability and death.
Ischaemia is a more common cause than haemorrhage and radiological imaging is
required to accurately differentiate these. Some specific risk factors for stroke
are non-modifiable--these include age, gender, racial and hereditary factors.
Certain risk factors for ischaemic stroke can be identified and modification of
these can be used for secondary prevention--examples include hypertension, heart
diseases, atrial fibrillation, diabetes mellitus, dyslipidaemia, smoking,
excessive alcohol consumption and carotid stenosis. Carotid endarterectomy is
valuable in selected patients. In ischaemic stroke and transient ischaemic attack
antithrombotic therapy is an option used in secondary prevention. In atrial
fibrillation, warfarin should be used where possible in secondary prevention.
When warfarin is contraindicated aspirin should be used. In other patients, an
antiplatelet regime is appropriate--aspirin is commonly used and is the least
expensive regime. Other antiplatelet agents such as dipyridamole, ticlopidine and
clopidogrel may have a place. Younger patients with ischaemic stroke may have a
thrombophilia state and should be appropriately investigated.
PMID- 10695497
TI - Submassive and massive pulmonary embolism: a target for thrombolytic therapy?
AB - Thrombolytic agents have been consistently demonstrated to dissolve pulmonary
thrombi much more rapidly and effectively than heparin alone. Rapid resolution of
pulmonary embolism (PE) is accompanied by a significant decrease in pulmonary
artery pressure and an improvement in right ventricular function. However, it is
no longer than 7 days until the findings of patients treated with heparin improve
to a similar extent. Previous studies were not designed to determine whether this
short-lasting difference in favor of thrombolysis can indeed affect the prognosis
of patients with PE and thus justify the 1% (or even higher) risk of cerebral or
fatal bleeding. Recently, two large registries demonstrated the importance of
right ventricular dysfunction assessed by echocardiography as an independent
predictor of mortality. Thrombolytic treatment was shown in one of these
registries to be associated with a 50% reduction of death risk in clinically
stable patients with right ventricular enlargement. It was thus possible to
identify a group of patients with massive PE who are most likely to benefit from
early thrombolysis. These findings now have to be confirmed by a prospective
randomized trial which will compare thrombolysis with heparin alone in this high
risk patient population, focusing on clinical end points such as overall and
event-free survival in the acute phase of PE.
PMID- 10695498
TI - Thrombolysis in arterial occlusion.
AB - Intra-arterial thrombolytic therapy has replaced systemic intravenous infusion of
thrombolytic agents as a treatment modality for arterial occlusion in the limbs.
Several catheter-guided techniques and various infusion methods and schemes have
been developed. At present there is no scientific proof of definite superiority
of any agent in terms of efficacy or safety but clinical practice favours the use
of urokinase or alteplase. Studies which compared thrombolysis to surgical
intervention suggest that thrombolytic therapy is an appropriate initial
management in patients with acute occlusion of a native leg artery or a bypass
graft. Underlying causative lesions are treated in a second step by endovascular
or open surgical techniques. Severe bleeding is the most feared complication: the
risk of hemorrhagic stroke is 1-2%.
PMID- 10695499
TI - Thrombolysis in newborns and infants.
AB - This review analyses literature reports from 1970 to 1998 assessing the use of
streptokinase (SK), urokinase (UK) or recombinant tissue-type plasminogen
activator (rt-PA) for thrombolytic therapy in neonates and infants. From 1970 to
1998 182 infants were reported to have received SK (n = 54; 29.5%), UK (n = 41;
22.5%) or rt-PA (n = 87; 48%). During thrombolytic therapy no concomitant heparin
administration or low dose heparin therapy (5 U/kg/h) were recorded. To perform
reocclusion prophylactics heparin was reinitiated at the end of thrombolytic
therapy usually in the recommended dosage of 20 U/ kg/h. The overall thrombolytic
patency rate in neonates varied from 39% to 86%. Besides bleeding from local
puncture sites or recent catheterisation sites (10.4%), pulmonary embolism was
reported in 1.1% of the 182 infants. Major bleeding complications, i.e. pulmonary
bleeding (0.6%), gastrointestinal bleeding (0.6%) or intraventricular haemorrhage
(IVH 2.7%) are rarely reported side effects and only 2 thrombolysis related
deaths due to haemorrhage were mentioned. Bleedings reported in the central
nervous system (n = 4) mainly occurred in preterm infants (n = 3). In conclusion,
data of this preliminary analysis suggest that there is no big difference (p =
0.09; chi2-test) in the efficacy rate between the 3 thrombolytic agents used in
the first year of life. In each case an assessment must be made with respect to
the relative benefit conferred by thrombolytic therapy in preventing organ or
limb damage versus the potential side effects, costs and inconvenience for the
childhood patient. Controlled prospective multicentre studies on thrombolytic
therapy in neonates and infants are recommended to evaluate patency rates and
adverse effects for the different thrombolytic agents used.
PMID- 10695500
TI - TNK-tPA for acute myocardial infarction: the clinical experience.
AB - Thrombolytic therapy has become the mainstay of treatment for acute transmural
myocardial infarction. Present fibrinolytic regimens have a number of
shortcomings, including the failure to induce early and sustained reperfusion in
as many as 40-50% of the patients, and to prevent reocclusion in another 10-20%
of the patients. The efforts for improving thrombolysis are focused on the
development of new agents (fibrinolytics, anticoagulants, and antiplatelet
agents). TNK-tPA is a triple combination mutant of wild-type tissue plasminogen
activator that exhibits a longer plasma half-life, an enhanced fibrin
specificity, and an increased resistance to the plasminogen activator inhibitor
1. This paper summarizes the results of clinical trials with TNK-tPA in acute
myocardial infarction.
PMID- 10695501
TI - Pharmacokinetics and pharmacodynamics of lanoteplase (n-PA).
AB - In acute myocardial infarction rapid, complete, and sustained reperfusion of the
infarct-related coronary artery is the most important therapeutic principle.
Lanoteplase or n-PA, a third-generation plasminogen activator consisting of a
deletion and point mutant of tissue-type plasminogen activator (t-PA), is a
promising agent to approach this therapeutic goal. The molecule exhibits an
increased plasma half-life allowing single-bolus administration. In this article,
after characterizing the n-PA molecule, the currently available pharmacokinetic
and pharmacodynamic data including the results of the InTIME study are reviewed.
PMID- 10695502
TI - Oral anticoagulation after a first episode of venous thromboembolism: how long?
How strong?
AB - A number of studies have been published in the last years which shed light on the
optimal intensity and the optimal duration of oral anticoagulation in patients
with venous thrombosis. Based on these studies it is now generally recommended to
treat patients with venous thromboembolism at an INR ranging from 2.0 to 3.0. The
optimal duration of anticoagulation mainly depends on the nature of the
thrombotic event. In patients with a temporary prothrombotic risk factor such as
surgery, immobilization or trauma a relatively short duration of oral
anticoagulation (3-6 months) is generally recommended. Patients with idiopathic
venous thromboembolism require a considerably longer duration of anticoagulation
(6 months at least).
PMID- 10695503
TI - Bed rest in deep vein thrombosis and the incidence of scintigraphic pulmonary
embolism.
AB - In several countries of central Europe, patients with acute proximal deep vein
thrombosis (DVT) are treated not only by anticoagulation and compression therapy
but additionally by strict bed rest for 6-8 days. Until now the theoretical
assumption that bed rest substantially reduces the incidence of pulmonary
embolism has not been subjected to empirical verification. Patients with acute
proximal DVT proven by ultrasonography were randomly assigned to strict bed rest
for 8 days (treatment group) or to stay mobilised (control group). In both
groups, basic treatment consisted in anticoagulation by subcutaneous low
molecular weight heparin/vitamin-K-antagonist and compression therapy. The
incidence of pulmonary embolism was assessed by serial ventilation/perfusion
SPECT on day 1 and days 8-10. Of the 309 patients with proximal DVT considered
for inclusion, 180 were excluded according to the study protocol, and 3 did not
give informed consent. One hundred and twenty-six patients were randomly assigned
to observe bed rest (n = 62) or to keep mobilised (n = 64). Four patients refused
follow-up lung scan. A new lung perfusion defect was detected in 10/59 patients
in the treatment group compared to 14/63 patients in the control group (one-sided
p-value = 0.25; power 0.8). Bed rest as an additional measure in the treatment of
DVT is not able to substantially reduce the incidence of scintigraphically
detectable pulmonary embolism. The discomfort and costs associated with the
prescription of bed rest in DVT are obviously inappropriate.
PMID- 10695504
TI - Anticoagulation after artificial valve replacement with or without atrial
fibrillation: how much is really needed?
AB - Insertion of a mechanical artificial heart valve is an absolute indication for
the use of lifelong oral anticoagulation, irrespective the presence or absence of
atrial fibrillation. Depending on the type and position of the artificial valve
the optimal International Normalized Ratio (INR) for these patients is between
2.5 and 4.5, although more prospective studies on the optimal range of oral
anticoagulation are necessary. Addition of low dose antiplatelet therapy may
further decrease the rate of thromboembolism, but also here more studies are
needed. Patients with a bioprosthesis need only oral anticoagulation for the
first three months following surgery in the absence of an indication for
anticoagulation for other conditions. Atrial fibrillation is often seen in
patients with artificial heart valves. Stroke prevention can be instituted by the
mandatory oral anticoagulant therapy. The presence of atrial fibrillation and the
use of oral anticoagulation prior to heart valve surgery support the indication
for the insertion of a mechanical artificial heart valve. However, relative
contraindications to oral anticoagulation and the presence of sinus rhythm may
favor the use of a bioprosthesis.
PMID- 10695505
TI - Platelet glycoprotein IIb/IIIa receptor blockade: lessening the risk of coronary
interventions.
AB - For the patient undergoing percutaneous coronary intervention, the administration
of a platelet glycoprotein IIb/IIIa receptor blocker reduces the incidence of a
periprocedural nonfatal myocardial infarction and the need for unplanned
emergency stenting. In the diabetic patient undergoing intracoronary stenting,
the use of a platelet glycoprotein IIb/IIIa receptor blocker appears to decrease
the need for subsequent target vessel revascularization. There is considerable
evidence in support of the use of glycoprotein IIb/IIIa receptor inhibitors in
all categories of patients--"high-risk" patients, "low-risk" patients, and those
undergoing primary angioplasty for acute myocardial infarction--and for the full
armamentarium of percutaneous procedures (angioplasty, directional atherectomy,
rotational atherectomy, and intracoronary stenting).
PMID- 10695506
TI - Low-molecular weight heparins in venous and arterial thrombotic disease.
AB - INTRODUCTION: Since the introduction of low-molecular-weight heparins (LMWHs) in
the early 1980's, the use of these compounds has been extensively investigated as
a substitute for unfractionated heparin (UFH) in patients with venous and
arterial thrombotic diseases. LMWHs have several advantages as compared to UFH,
such as the subcutaneous route of administration, the predictable anticoagulant
response and the lack of the need for laboratory monitoring. The present
systematic review evaluates randomised clinical trials which investigated the
efficacy and safety of LMWH in the acute treatment of venous thromboembolism,
myocardial infarction, unstable coronary syndromes and ischemic stroke. METHODS:
A computerised and manual search was performed to identify all relevant clinical
trials. All randomised studies, with an a priori defined study population,
clinical outcome measurement and adequate follow-up, were reviewed by two
independent assessors. Whenever possible a common effect estimate of the included
studies was calculated. RESULTS: Thirteen studies in approximately 4000 patients
with acute venous thromboembolism revealed an odds ratio for the 3-month
recurrent thromboembolism rate and major bleeding complications during exposure
of 0.77 (C.I. 0.57-1.04) and 0.61 (C.I. 0.39-0.95), respectively, in favour of
LMWH as compared to UFH. In patients with acute myocardial infarction, one study
suggested a reduction in the incidence of reinfarction and cardiac death in LMWH
recipients compared to UFH, while a placebo-controlled study revealed no
beneficial effect of LMWH on these outcomes. In six studies including over 7000
patients with acute unstable coronary syndromes, there was an odds ratio for
recurrent angina, myocardial infarction, urgent revascularisation and major
bleedings of 0.88 (C.I. 0.76-1.01), 0.84 (C.I. 0.69-1.01), 0.83 (C.I. 0.70-0.99),
1.09 (C.I. 0.70-1.70), respectively, in favour of LMWH compared to UFH. The three
studies comparing LMWH treatment with placebo in approximately 1000 patients with
acute ischemic stroke revealed an odds ratio for the 10-day recurrent stroke,
death or disability after 3 months and major bleeding complications of 0.68 (C.I.
0.41-1.13), 0.94 (C.I. 0.78-1.15), 2.92 (C.I. 1.88-4.55), respectively.
CONCLUSION: Fixed-dose subcutaneous LMWH appears to be a safe and effective
alternative for dose-adjusted intravenous heparin in the treatment of patients
with acute venous thrombotic disease as well as in patients with acute unstable
coronary syndromes. The effectiveness of LMWH in patients with acute myocardial
infarction remains unclear. There seems to be no beneficial effect of LMWH
treatment as compared to placebo in patients with acute ischemic stroke, while
the risk of major bleeding was clearly increased.
PMID- 10695507
TI - Heparin-induced thrombocytopenia--pathogenesis and treatment.
AB - Heparin-induced thrombocytopenia (HIT) is now recognized as the most frequent
immune-mediated adverse drug reaction. During the last decade, fundamental
aspects of the pathogenesis of HIT have been resolved. The understanding of some
the mechanisms underlying the development of new, paradox thromboembolic
complications in HIT led to the concept that thrombin generation plays a key-role
in clinically manifest HIT. Consequently new therapeutic concepts imply the use
of drugs with either indirect or direct anti-thrombin activity such as donaparoid
sodium and the recombinant hirudin lepirudin. During the last years results of
first prospective studies assessing various treatment regimens in HIT became
available. Although data of randomized trials are still missing some treatment
recommendations can already be drawn from these studies. This review summarizes
key aspects of the pathogenesis of HIT and provides an overview of current
treatment strategies.
PMID- 10695508
TI - Ultrasound thrombolysis.
AB - The possibility of lysing clots by the direct intravascular application of
ultrasound was described first in 1974 in an animal experiment. However research
on therapeutic ultrasound for thrombolysis gained momentum in the early 1980s and
is now divided into several directions: 1) pharmacological thrombolysis supported
by externally applied ultrasound; 2) pharmacological thrombolysis accelerated by
intravascular ultrasound; 3) lysis of intravascular clots by intravascular
ultrasound applied as singular treatment; 4) facilitating angioplasty by
intravascular ultrasound which may smoothen the rigid surface of calcified
arteries by lysing calcified structures out of sclerotic plaques. In acute
myocardial infarction first evidence of efficacy in lysing clots by ultrasound
was described in two small series of 15 patients in 1997. Furthermore, ultrasound
thrombolysis seems to be efficient also in occluded saphenous vein grafts and in
completely obstructed peripheral arteries, where the latest clinical experience
gives very promising results.
PMID- 10695509
TI - Primary stenting for acute myocardial infarction.
AB - Primary stenting for acute MI has been shown to be an improvement over PTCA
alone. As with primary PTCA however there is an obligate delay in restoration of
TIMI flow due to the time necessary for mobilization of the cath lab team. It is
possible that a hybrid approach using partial thrombolysis plus early IIB/IIIA
inhibitor administration followed by urgent angiography and stenting of the
culprit lesion will be the ideal approach.
PMID- 10695510
TI - Prevention of restenosis after percutaneous coronary interventions: the medical
approach.
AB - Restenosis following successful percutaneous coronary revascularization continues
to represent a major problem limiting the clinical efficacy of this procedure.
The underlying mechanisms of restenosis are comprised of a combination of effects
from vessel recoil, negative vascular remodeling, thrombus formation and
neointimal hyperplasia. Indeed, there are important interactions among all of
these mechanisms. For example, neointimal hyperplasia is stimulated by growth
factors, which are released by local thrombi and the injured arterial segment
itself, and act to enhance the expression of other growth-regulating proteins, in
particular "second messengers", proto-oncogenes and other cell cycle controlling
proteins. This results in an inflammatory and myofibroproliferative response,
which may worsen vessel narrowing caused by recoil and result in the formation of
a clinically significant restenotic lesion. A multitude of pharmacologic trials
have been conducted in an attempt to prevent restenosis, but most have
demonstrated little benefit. Studies in smaller numbers of patients have
suggested a potential benefit for several classes of agents, including: 1) the
antiproliferatives, angiopeptin, trapidil and tranilast; 2) selective elimination
or alteration of proliferating cells; 3) enhancement of natural growth
inhibitors; and 4) signal transduction blockade or inhibition of the gene
expression for various growth-stimulating proteins. Finally, there have been
advances in related areas, including development of antithrombotic catheters,
novel polymers, and more efficient methods for transferring genes into the vessel
wall. All of these offer the possibility of delivering agents (drugs, genes, or
antisense oligonucleotides) locally at the site of intervention in a way that may
optimize antiproliferative effects while minimizing systemic effects--ultimately
leading to a more specific inhibition of the restenosis process.
PMID- 10695511
TI - Stents for the treatment of aortic aneurysms. Review of devices, technique and
results.
AB - The endovascular treatment of abdominal aortic aneurysms has generated a great
deal of interest since the early 1990s, and many different devices are currently
available. The procedure of endovascular repair has been evaluated in many
institutions and the different devices are compared. The first results were
encouraging, but complications like endoleak, dislocation or thrombosis of the
graft occurred. By the available devices the stent application is only promising,
if the known exclusion criteria are strictly respected. Therefore a careful
preinterventional assessment of the patient by different imaging modalities is
necessary. As the available results up to now are preliminary and the durability
of the devices has to be controlled, multicenter studies are required to improve
the devices and observe their long-term success in the exclusion of abdominal
aortic aneurysms.
PMID- 10695512
TI - Treatment of carotid artery stenosis by elective stent placement instead of
carotid endarterectomy in patients with severe coronary artery disease.
AB - Patients with concomitant cardiac and cerebrovascular disease undergoing
revascularization procedures are at high risk of both, cardiac and
cerebrovascular complications. The purpose of our study was to evaluate the
feasibility of prior elective carotid artery stenting as an alternative treatment
procedure to carotid endarterectomy (CEA) in patients with concomitant coronary
artery disease (CAD), who clearly needed coronary revascularization. We offered
extracranial internal carotid stenting to 85 patients with 89 significant carotid
stenoses. Out of these, 19 patients were symptomatic. The quantitative mean
reduction in diameter was 77 +/- 11%. Stent implantation was successful in 88
lesions. Two disabling major and 3 reversible minor strokes occurred
periprocedurally. Three patients showed asymptomatic restenosis and stent
deformation was detected in 2 patients. Based on this experience, carotid
stenting in high risk patients with severe coronary artery disease is feasible
and safe and might be indicated as an alternative procedure for combined surgery.
PMID- 10695513
TI - Identifying substance abusing delivering women: consequences for child
maltreatment reports.
AB - OBJECTIVE: The major objective was to determine how and the extent to which
SB2669, which requires the identification of substance abusing delivering women,
affected the number of children reported for abuse or neglect in several
California counties. METHOD: A monthly time-series model from April 1988 to
December 1995 was constructed. The idea underlying the model was that month-to
month changes in the number of child maltreatment reports was a response to the
presence of SB2669 in addition to various demographic, social, and economic
factors. By separately estimating each county's number of reports, it was assumed
that SB2669 did not necessarily affect each county's reports by the same amount,
perhaps partially because of different counties' implementation strategies or
general policies. Our sampling size consisted of seven high prevalence counties.
RESULTS: The results suggest that the effects of SB2669 on the number of child
maltreatment reports are mixed. On an aggregate level, all else constant, and at
least for a few years after the passage of SB2669, SB2669 is associated with a
decrease in child maltreatment reports in two of the participating counties. This
decrease may be due to conscientious implementation of the legislation in these
counties. This mixed finding is expected mainly because SB2669, although
mandated, was never enforced. Moreover, from the process component of the study
we learned that the implementation practices of this legislation vary
substantially between and even within counties' hospitals. CONCLUSIONS/FUTURE
DIRECTIONS: A decrease in maltreatment reports in the presence of SB2669 is not
necessarily the most desirable outcome in the light of what we know about the
relationship between substance abuse and child maltreatment. Law makers need to
rethink the purpose of the law and provide the necessary language, tools and
training to ensure that the goals of identifying substance abusing mothers and
their families are met. Provisions also need to be made that somehow enforce this
legislation. These provisions could lessen county-level and hospital-level
variability in implementing the law.
PMID- 10695514
TI - Maltreatment of children with disabilities: training needs for a collaborative
response.
AB - PROBLEM STATEMENT: There is a dearth of research on how to respond to children
with disabilities who have been maltreated. The literature that does exist
recommends a collaborative team approach, with each team member possessing a
broad understanding of the special considerations of working with children with
disabilities. The literature does not define current understanding levels of
response team members in comparison to essential knowledge levels. METHOD: The
current study used a needs assessment instrument tailored to each of three key
groups: parents, educators, and investigators. Respondents were asked about their
knowledge level, experience with, and training interests on maltreatment of
children with disabilities. RESULTS: While respondents seemed to have a cursory
awareness in some of the topic areas, their knowledge levels were not extensive
in most of the survey areas. A majority of respondents were willing to attend
training, and all three groups ranked the recognition of maltreatment of children
with disabilities as a top training priority. CONCLUSIONS: It was concluded that
these integral players in the response to maltreatment of children with
disabilities are receptive to becoming more effective partners, by attending
training to bridge the knowledge gaps they possess. The current study helps
document the nature of those knowledge gaps and, thereby informs the development
of training programs for building a more coordinated and informed response to
maltreatment of children with disabilities.
PMID- 10695515
TI - Enhancing law enforcement identification and investigation of child maltreatment.
AB - OBJECTIVE: Data from two independent studies is presented, representing the
investigators' ongoing work with faculty from a state criminal justice academy to
analyze existing knowledge and skill levels among veteran law enforcement
officers and recruits, as well as to enhance future training. METHOD: Through an
anonymous questionnaire, the first of these studies examined officers'
perceptions of maltreatment, including those factors that do and do not influence
a determination of whether a particular act constitutes child maltreatment and
assessments of whether particular acts constitute abuse or neglect. The second
study also utilized an anonymous questionnaire to examine officers' knowledge of
the developmental strengths and limitations of children relative to their ability
to provide accurate information in suspected cases of child maltreatment.
RESULTS: As hypothesized, several gaps both in law enforcement officers'
knowledge of certain characteristics that can serve to denote a case of
maltreatment and their knowledge of fundamental developmental issues and
interview techniques that could assist them in the performance of their
professional duties are identified. CONCLUSIONS: Suggestions for enhanced law
enforcement training programs are presented and discussed.
PMID- 10695516
TI - The effects of daily stressors on physical health in women with and without a
childhood history of sexual abuse.
AB - OBJECTIVE: The primary purpose of the present study was to examine the
relationship between daily stressors and physical symptoms in college-age women
with a childhood history of sexual abuse and women without a history of childhood
sexual abuse. It was hypothesized that women with a history of childhood sexual
abuse would be particularly susceptible to the effects of daily stressors on
physical symptoms, and would show more covariation between daily stressors and
physical symptoms, compared to women without a history of childhood sexual abuse.
METHOD: Female college students (n = 491) were screened for histories of
childhood (before age 15) and adulthood (after age 15) contact sexual abuse. Of
these participants, 18 women with only a history of childhood sexual abuse were
assigned to the SA group, and 27 women with no history of childhood or adulthood
sexual abuse were assigned to the NA group. These women filled out self-report
measures of daily hassles and physical symptoms for 28 consecutive days. RESULTS:
During the 5 days preceding a highly stressful day, women in the SA group
reported significantly more physical symptoms than during the 5 days preceding a
day of low stress. For the NA group, there were no significant differences in
reported physical symptoms between high- and low-stress days. CONCLUSIONS: The
pattern of results for physical symptoms suggests that women with a history of
childhood sexual abuse may be particularly susceptible to the effects of
heightened daily stress, and may display this susceptibility in the report of
physical symptoms. Possible explanations for these findings are discussed.
PMID- 10695517
TI - Child characteristics which impact accuracy of recall and suggestibility in
preschoolers: is age the best predictor?
AB - OBJECTIVE: The purpose of the present study was to determine whether individual
difference factors of metamemory, intelligence, and temperament can improve the
ability to predict accuracy of recall and suggestibility in preschoolers. METHOD:
Fifty-six children ranging in age from 43 months to 83 months (M = 61, SD = 9)
were recruited from 13 child care centers in a rural southeastern town. Children
participated in a "Circus Day" event conducted by two female undergraduate
psychology students dressed as clowns. Approximately 10 days (M = 10; SD = 2)
after the event, children were interviewed regarding their experiences. RESULTS
AND CONCLUSIONS: Bivariate correlations and multiple regression analyses were
performed in order to determine which factors were related and unique
contributors to accuracy of recall and suggestibility. Of principal importance is
the finding that child characteristics such as metamemory ability, intellectual
functioning, and temperament may indeed be helpful in determining a child's
capacity to accurately recall information in an interview, although for the most
part age is the best predictor. Findings also underscore the importance of
considering a child's SES and race when planning and conducting interviews with
young children. Possible explanations for these findings as well as implications
for future research and clinical application are discussed.
PMID- 10695518
TI - Differentiating incest survivors who self-mutilate.
AB - OBJECTIVE: This study was an exploratory analysis of the variables which
differentiated incest survivors who self-mutilate from those who do not. METHOD:
A sample of women incest survivors (N = 84) were divided into two groups based on
the presence or absence of self-mutilation. Participants included both community
and clinical populations. A packet consisting of a demographic questionnaire,
Sexual Attitudes Survey, Diagnostic Inventory of Personality and Symptoms,
Dissociative Events Scale and the Beck Depression Inventory was completed by each
participant. RESULTS: Demographic, incest, and family of origin variables
distinguished the self-mutilating women from those who did not. These include
ethnicity and educational experiences; duration, frequency, and perpetrator
characteristics regarding the incest; and multiple abuses, instability, birth
order, and loss of mother in one's family of origin. Psychological and physical
health concerns also differentiated between the two groups. CONCLUSIONS: Many
variables may differentiate between women incest survivors who self-mutilate from
those who do not. A rudimentary checklist to describe the lives of incest
survivors who self-mutilate resulted from these findings. The importance of the
concept of embodiment is also discussed.
PMID- 10695519
TI - Texture response patterns associated with sexual trauma of childhood and adult
onset: developmental and recovered memory implications.
AB - OBJECTIVE: Reduce texture sensitivity on the Rorschach is proposed as a sequela
of early sexual abuse that is unlikely to be contaminated by situational
variables. If this conceptualization has merit, texture attributes offer a
roadmap for studying vying claims in the recovered memory debate. To explore this
possibility, we examined the extent to which intense preoccupation with sexual
trauma of childhood and of adult onset was related to reduced texture
productivity. METHOD: Texture productivity was measured in 4 groups comprised of
108 patients using the Rorschach. Twenty-seven patients with recovered memory
were compared with 27 patients with continuous memory of childhood sexual trauma,
27 post trauma stress patients with sexual trauma of adult onset, and 27 non
abused patients. RESULTS: The study replicated previous findings of reduced
texture productivity among patients who always remembered sexual trauma of
childhood-onset. The same texture deficiency pattern was observed among patients
who recovered memory of childhood sexual abuse. This pattern was not observed in
Post Traumatic Stress Disorder (PTSD) patients intensely preoccupied with sexual
trauma of adult onset despite the fact that they mimicked the recovered memory
group in respect to enduring preoccupation with distressing thoughts of sexual
abuse. CONCLUSION: The findings indicate that intrusive memories of sexual trauma
do not shape patients' response to textural cues on the Rorschach. Variations in
texture productivity are primarily moderated by age of trauma onset. Dismissal of
claims of recovered memories on the basis of intense sexual preoccupation is not
warranted.
PMID- 10695520
TI - Risk factors and child sexual abuse among secondary school students in the
Northern Province (South Africa).
AB - OBJECTIVE: This is an investigation into the risk factors that could discriminate
childhood sexual abuse (CSA) from non-abuse in the Northern Province (South
Africa). METHOD: 414 students in standard 9 and 10 in three secondary schools in
the province filled-in a retrospective self-rating questionnaire in a classroom
setting. Questionnaires included modified and adapted questions from the
Finkelhor's (1979) Risk Factor Checklist, and asked for physical contact forms of
sexual abusive experiences of participants before the age of 17 years with an
adult or a person at least 5 years older or a person in a position of power.
RESULT: It shows an overall (N = 414) CSA prevalence rate of 54.2%. Only four
factors (from eight)-ethnicity not Northern Sotho, mother employed and not as
laborer, a stepparent present in the family during childhood, and violence at
home not seldom-significantly discriminated CSA from non-abuse. Increase in the
number of combination of the four significant factors also increases the
probability of the discrimination in a linear manner. CONCLUSION: With some
caution, we recommend the four significant risk factors for use while planning
preventive strategies against childhood sexual abuse, and a massive campaign
against child sexual abuse in the province. More job opportunities should be
created in the province.
PMID- 10695521
TI - Disclosure of child sexual abuse.
PMID- 10695522
TI - Delay in disclosure of childhood rape: results from a national survey.
AB - OBJECTIVE: This study sought to gather representative data regarding the length
of time women who were raped before age 18 delayed prior to disclosing such
rapes, whom they disclosed to, and variables that predicted disclosure within 1
month. METHOD: Data were gathered from 3,220 Wave II respondents from the
National Women's Study (Resnick, Kilpatrick, Dansky, Saunders, & Best, 1993), a
nationally representative telephone survey of women's experiences with trauma and
mental health. Of these, 288 retrospectively reported at least one rape prior to
their 18th birthday. Details of rape experiences were analyzed to identify
predictors of disclosure within 1 month. RESULTS: Fully 28% of child rape victims
reported that they had never told anyone about their child rape prior to the
research interview; 47% did not disclose for over 5 years post-rape. Close
friends were the most common confidants. Younger age at the time of rape, family
relationship with the perpetrator, and experiencing a series of rapes were
associated with disclosure latencies longer than 1 month; shorter delays were
associated with stranger rapes. Logistic regression revealed that age at rape and
knowing the perpetrator were independently predictive of delayed disclosure.
CONCLUSIONS: Delayed disclosure of childhood rape was very common, and long
delays were typical. Few variables were identified that successfully predicted
disclosure behavior, but older age and rape by a stranger were associated with
more rapid disclosure. This suggests that the likelihood of disclosure in a given
case is difficult to estimate, and predictions based on single variables are
unwarranted.
PMID- 10695523
TI - Mental health problems among children living in war zones.
PMID- 10695524
TI - Post traumatic stress disorder reactions in children of war: a longitudinal
study.
AB - OBJECTIVE: To establish rates of posttraumatic stress disorder (PTSD) reactions
and general mental health problems in children who had experienced war trauma.
METHOD: A longitudinal study in the Gaza strip with 234 children aged 7 to 12
years, who had experienced war conflict, at 1 year after the initial assessment,
that is, during the peace process. Children completed the Child Post Traumatic
Stress Reaction Index (CPTS-RI), while the Rutter A2 and B2 Scales were completed
by parents and teachers. RESULTS: The rate of children who reported moderate to
severe PTSD reactions at follow-up had decreased from 40.6% (N = 102) to 10.0% (N
= 74). 49 children (20.9%) were rated above the cut-off for mental health
problems on the Rutter A2 (parent) Scales, and 74 children (31.8%) were above the
cut-off on the Rutter B2 (teacher) Scales. The total scores on all three measures
had significantly decreased during the 1-year period. The total CPTS-RI score at
follow-up was best predicted by the number of traumatic experiences recalled at
the first assessment. CONCLUSIONS: PTSD reactions tend to decrease in the absence
of further stressors, although a substantial proportion of children still present
with a range of emotional and behavioral problems. Cumulative previous experience
of war trauma constitutes a risk factor for continuing PTSD symptoms.
PMID- 10695525
TI - Model-free functional MRI analysis using Kohonen clustering neural network and
fuzzy C-means.
AB - Conventional model-based or statistical analysis methods for functional MRI
(fMRI) suffer from the limitation of the assumed paradigm and biased results.
Temporal clustering methods, such as fuzzy clustering, can eliminate these
problems but are difficult to find activation occupying a small area, sensitive
to noise and initial values, and computationally demanding. To overcome these
adversities, a cascade clustering method combining a Kohonen clustering network
and fuzzy, means is developed. Receiver operating characteristic (ROC) analysis
is used to compare this method with correlation coefficient analysis and t test
on a series of testing phantoms. Results shown that this method can efficiently
and stably identify the actual functional response with typical signal change to
noise ratio, from a small activation area occupying only 0.2% of head size, with
phase delay, and from other noise sources such as head motion. With the ability
of finding activities of small sizes stably this method can not only identify the
functional responses and the active regions more precisely, but also discriminate
responses from different signal sources, such as large venous vessels or
different types of activation patterns in human studies involving motor cortex
activation. Even when the experimental paradigm is unknown in a blind test such
that model-based methods are inapplicable, this method can identify the
activation patterns and regions correctly.
PMID- 10695526
TI - Quantitative spectral/spatial analysis of phased array coil in magnetic resonance
imaging based on method of moment.
AB - A new approach for analysis of RF coils in magnetic resonance (MR) experiments is
reported. Instead of assuming current distribution in conventional quasi-static
algorithm, this approach transforms the coil geometry into an equivalent circuit
for complex current calculation. Self and mutual inductance are taken into
consideration. Frequency responses of RF coils and transverse magnetic field (B1)
maps can be simulated. This approach is especially efficient for phased array
coil design for its small matrix size when implemented on computers. Experiments
on both single surface coil and phased array coils are consistent with simulation
results. Index Terms-Magnetic resonance, method of moment, phased array coil, RF
coil.
PMID- 10695527
TI - Application of Bayesian inference to fMRI data analysis.
AB - The methods of Bayesian statistics are applied to the analysis of fMRI data.
Three specific models are examined. The first is the familiar linear model with
white Gaussian noise. In this section, the Jeffreys' Rule for noninformative
prior distributions is stated and it is shown how the posterior distribution may
be used to infer activation in individual pixels. Next, linear time-invariant
(LTI) systems are introduced as an example of statistical models with nonlinear
parameters. It is shown that the Bayesian approach can lead to quite complex
bimodal distributions of the parameters when the specific case of a delta
function response with a spatially varying delay is analyzed. Finally, a linear
model with auto-regressive noise is discussed as an alternative to that with
uncorrelated white Gaussian noise. The analysis isolates those pixels that have
significant temporal correlation under the model. It is shown that the number of
pixels that have a significantly large auto-regression parameter is dependent on
the terms used to account for confounding effects.
PMID- 10695528
TI - Performance analysis of maximum intensity projection algorithm for display of MRA
images.
AB - The maximum intensity projection (MIP) is a popularly used algorithm for display
of MRA images, but its performance has not been rigorously analyzed before. In
this paper, four measures are proposed for the performance of the MIP algorithm
and the quality of images projected from three-dimensional (3-D) data, which are
vessel voxel projection probability, vessel detection probability, false vessel
probability, and vessel-tissue contrast-to-noise ratio (CNR). As side products,
vessel-missing probability, vessel receiver operating characteristics (ROC's),
and mean number of false vessels are also studied. Based on the assumptions that
the intensities of vessel, tissue, and noise along a projection path are
independent Gaussian, these measures are derived and obtained all in closed
forms. All the measures are functions of explicit parameters: vessel-to-tissue
noise ratio (VTNR) and CNR of 3-D data prior to the MIP, vessel diameter, and
projection length. It is shown that the MIP algorithm increases the CNR of large
vessels whose CNR prior to the MIP is high and whose diameters are large. The
increase in CNR increases with projection path length. On the other hand, all the
proposed measures indicate that the small vessels that have low CNR prior to the
MIP and small diameters suffer from the MIP. The performance gets worse as
projection path length increases. All measures demonstrate a better performance
when the vessel diameter is larger. Other properties and possible applications of
the derived measures are also discussed.
PMID- 10695529
TI - Classifying mammographic mass shapes using the wavelet transform modulus-maxima
method.
AB - In this article, multiresolution analysis, specifically the discrete wavelet
transform modulus-maxima (mod-max) method, is utilized for the extraction of
mammographic mass shape features. These shape features are used in a
classification system to classify masses as round, nodular, or stellate. The
multiresolution shape features are compared with traditional uniresolution shape
features for their class discriminating abilities. The study involved 60
digitized mammographic images. The masses were segmented manually by
radiologists, prior to introduction to the classification system. The
uniresolution and multiresolution shape features were calculated using the radial
distance measure of the mass boundaries. The discriminating power of the shape
features were analyzed via linear discriminant analysis (LDA). The classification
system utilized a simple Euclidean metric to determine class membership. The
system was tested using the apparent and leave-one-out test methods. The
classification system when using the multiresolution and uniresolution shape
features resulted in classification rates of 83% and 80% for the apparent and
leave-one-out test methods, respectively. In comparison, when only the
uniresolution shape features were used, the classification rates were 72 and 68%
for the apparent and leave-one-out test methods, respectively.
PMID- 10695530
TI - Classification of malignant and benign masses based on hybrid ART2LDA approach.
AB - A new type of classifier combining an unsupervised and a supervised model was
designed and applied to classification of malignant and benign masses on
mammograms. The unsupervised model was based on an adaptive resonance theory
(ART2) network which clustered the masses into a number of separate classes. The
classes were divided into two types: one containing only malignant masses and the
other containing a mix of malignant and benign masses. The masses from the
malignant classes were classified by ART2. The masses from the mixed classes were
input to a supervised linear discriminant classifier (LDA). In this way, some
malignant masses were separated and classified by ART2 and the less
distinguishable benign and malignant masses were classified by LDA. For the
evaluation of classifier performance, 348 regions of interest (ROI's) containing
biopsy proven masses (169 benign and 179 malignant) were used. Ten different
partitions of training and test groups were randomly generated using an average
of 73% of ROI's for training and 27% for testing. Classifier design, including
feature selection and weight optimization, was performed with the training group.
The test group was kept independent of the training group. The performance of the
hybrid classifier was compared to that of an LDA classifier alone and a
backpropagation neural network (BPN). Receiver operating characteristics (ROC)
analysis was used to evaluate the accuracy of the classifiers. The average area
under the ROC curve (A(z)) for the hybrid classifier was 0.81 as compared to 0.78
for the LDA and 0.80 for the BPN. The partial areas above a true positive
fraction of 0.9 were 0.34, 0.27 and 0.31 for the hybrid, the LDA and the BPN
classifier, respectively. These results indicate that the hybrid classifier is a
promising approach for improving the accuracy of classification in CAD
applications.
PMID- 10695531
TI - Confidence maps and confidence intervals for near infrared images in breast
cancer.
AB - This paper extends basic concepts of statistical hypothesis testing and
confidence intervals to images generated by a new procedure for near infrared
spectroscopic tomography being developed for use in breast cancer diagnosis. By
estimating the covariance matrix of the pixels of an image from data used in the
image reconstruction process, confidence maps for statistical tests on individual
pixels and confidence intervals for entire images are displayed as an aid to
research and clinical personnel interpreting possibly noisy images. The methods
are applied to simulated and phantom-based images.
PMID- 10695532
TI - Calculation of attenuation factors from combined singles and coincidence emission
projections.
AB - We have developed a simple method for determining coincidence attenuation
correction factors C (the inverse of the total attenuation factors) from
collimated singles (SPECT) and coincidence [positron emission tomography (PET)]
projections without transmission data. Attenuation-correction factor estimates
are determined for individual lines of response (LOR's) independently. The
required data can be acquired using a gamma-camera system with coincidence
capabilities. A first-order approximation (R) of C for an LOR is given by the
product of the singles count rates, taken at each end of the LOR divided by the
square of the coincidence count rate. The method was tested using simulated
singles and coincidence projections starting with emission and attenuation maps
from patient PET scans. Noise and resolution effects were modeled in separate
studies. In the noise-free, high-resolution simulations, a scatter plot of the C
values versus the corresponding R values for all LOR's produces a well-defined
trajectory with little variance. Values of lnR were reconstructed into good
quality attenuation maps that compare favorably with the originals. We conclude
that the method works well on ideal data. The introduction of noise results in
degraded images. In a simulated patient study, lung and outer body boundaries
were visible in images produced with 3.2 x 10(4) coincidence counts.
PMID- 10695533
TI - Implantation of endovascular stents for hypoplasia of the transverse aortic arch.
AB - Hypoplasia of the transverse aortic arch is commonly associated with aortic
coarctation. Persistent or recurrent obstruction can occur at this level after
successful repair of the native coarcted segment. The purpose of this report is
to present a new technique to treat such lesions, namely with implantation of a
balloon-expandable stent. This approach was used successfully in 4 children with
such hypoplasia occurring after repair of coarctation. Implantation led to both
anatomical and physiological relief of obstruction in all. The patients tolerated
the procedure, and there were no major adverse events.
PMID- 10695534
TI - Cyanotic nephropathy and use of non-ionic contrast agents during cardiac
catherization in patients with cyanotic congenital heart disease.
AB - BACKGROUND: Chronic cyanosis with its associated rheologic changes is a known
risk factor for glomerular nephropathy. Therefore, contrast-induced
nephrotoxicity should be an important consideration for angiographers comparable
to diabetics. On the other hand, progressions in diagnostic and interventional
techniques have led to expanded indications and a more widespread use of x-ray
contrast agents. The aim of this study was to investigate the risk of contrast
induced nephropathy in the small group of patients with cyanotic heart disease
prior to surgical repair. METHODS: We investigated 23 cyanotic patients with an
oxygen saturation of 82 (50-92)%, age 25 (5-63) years, and 13 control subjects
with atrial septal defect, age 37 (20-66) years. Blood viscosity was measured
before and after cardiac catherization. Renal damage was evaluated by selective
analysis of urinary proteins and enzymes. RESULTS: Before cardiac
catheterization, 48% of the cyanotic patients had a moderate glomerulopathy.
Cardiac catherization was performed with 3.0 (1.2-6.8) mls/kg non ionic contrast
medium. Only one of the 23 patients (4.3%) with normal urinary analysis before
cardiac catheterization showed renal damage, which involved tubular and
glomerular function. Elevated blood viscosity in cyanotic patients was slightly
reduced by the contrast. None of the acyanotic controls had contrast-induced
nephropathy. CONCLUSIONS: The use of non-ionic contrast medium does not worsen
cyanotic glomerulopathy. This finding may be due to the reduction of blood
viscosity by the application of the contrast medium. The finding of contrast
induced nephropathy in one patient underlines the importance of monitoring renal
function after cardiac catheterization.
PMID- 10695535
TI - Coronary arterial fistulas in childhood.
AB - We reviewed 16 patients with coronary arterial fistulas seen between 1976 and
1997, and aged 2 days to 16 years, with a median age of 3.2 years. Only four
patients were symptomatic: two had heart failure, one had exertional dyspnoea,
and one infective endocarditis. The fistulas originated from the right coronary
artery in seven patients, from the left coronary artery in seven, from both
coronary arteries in one patient, while the origin was not clearly defined in the
final patient. Associated cardiac anomalies were discovered in six patients, with
three of the fistulas being diagnosed at the same presentation. Cross-sectional
echocardiography had revealed a dilated coronary artery in 7 out of 11 subjects.
The ratio of pulmonary to systemic flows ranged between 0.9 to 3.0, with a median
of 1.5. Ten patients were referred for corrective surgery without any mortality.
Trans-catheter closure was successfully undertaken in one patient, while
spontaneous closure of the fistula was noted in two patients. We conclude that
coronary arterial fistulas, although rare and potentially serious, are generally
treatable.
PMID- 10695536
TI - Myocardial perfusion scanning in patients considered for late arterial switch.
AB - BACKGROUND: Our aims were to evaluate left ventricular uptake of radionuclide in
patients with Mustard's or Senning's procedure, comparing them with patients who
had undergone banding of the pulmonary trunk and conversion to the arterial
switch. METHODS: Technetium perfusion scans were performed on 27 patients (25
male), aged from 10 to 28 years with a mean of 17.8 years and a standard
deviation of 5.8 years, who had undergone Mustard's or Senning's procedure for
correction of complete transposition. Of the 27 patients, six had been accepted
for staged conversion to an arterial switch. At the time of the study, two of the
six patients had undergone completion to the switch and four had undergone
banding of the pulmonary trunk with two then proceeding to the arterial switch.
Cardiac catheterisation to measure left ventricular pressure was performed in all
six patients and scores for left ventricular uptake of isotope were compared with
echocardiographic index of the thickness of the left ventricular posterior wall
and measurements of left ventricular pressure. RESULTS: Uptake of isotope by the
left ventricle was generally poor, but was higher in patients following banding
and conversion to the arterial switch, as well as in two patients with native
obstruction of the left ventricular outflow tract, and one other who subsequently
was found to have pulmonary venous obstruction. There was a positive correlation
between the thickness of the left posterior wall in diastole and left ventricular
uptake of isotope (r = 0.74, p < 0.05). There also a positive correlation between
left ventricular pressure and uptake of the isotope (r = 0.68, p < 0.05).
CONCLUSIONS: Uptake of radionuclide by the left ventricle after Mustard's or
Senning's procedure for complete transposition appears to reflect ventricular
pressure and myocardial mass. A prospective study would be required to determine
the predictive ability of such scans regarding the ultimate outcome of conversion
to arterial switch, but our initial findings suggest that the technique provides
an additional non-invasive method of monitoring left ventricular response to
pulmonary arterial banding.
PMID- 10695537
TI - Neonatal intrapericardial teratomas: clinical and surgical considerations.
AB - Intrapericardial teratomas are rare primary cardiac tumors of infancy and
childhood. We describe three neonates with intrapericardial teratomas diagnosed
during fetal life and treated after birth. Clinical and anatomic considerations
suggest that cardiopulmonary bypass provides for safe tumor dissection and
complete excision of the tumor, thereby decreasing the risk of recurrence.
PMID- 10695538
TI - The morphologic variability in atrioventricular valvar atresia.
PMID- 10695539
TI - A unique case of ventricular isomerism?
AB - Isomerism of the atria has often been described with various complex cardiac
malformations. As far as is known, a case of 'ventricular isomerism' has never
been recorded. Described is a specimen where, on the basis of morphological
criterions, there are two right ventricles.
PMID- 10695540
TI - Coarctation of the aorta in dizygotic twins.
AB - The incidence of congenital heart disease is higher in monozygotic than dizygotic
twins, with a higher concordance rate. Although coarctation of the aorta has
previously been reported in monozygotic twins, to the best of our knowledge it
has not been described in dizygotic twins. We report here such a concurrence in
dizygotic twins conceived by in-vitro fertilisation. The finding provides support
for both genetic and environmental factors in the aetiology of congenital heart
disease. Furthermore, it highlights our lack of data regarding the outcome of in
vitro fertilisation.
PMID- 10695541
TI - Sudden cardiac death in infancy due to histiocytoid cardiomyopathy.
AB - Detailed post-mortem is crucial in infants who die suddenly and without a known
cause. We report a rare case of histiocytoid cardiomyopathy with endocardial
fibroelastosis, the second case in the world literature. The infant presented
with sudden death, but the cardiac histological appearance was initially believed
to be caused by Pompes disease.
PMID- 10695542
TI - A "friendly" system for pericardial drainage.
AB - We describe an alternative to the water-seal system, suitable for drainage of
pericardial and eventually pleural effusions, which has been shown to be safe,
effective, not painful, and rather "friendly", providing patients with a smoother
clinical course.
PMID- 10695543
TI - Fetal diagnosis of common arterial trunk with interrupted aortic arch using color
power Doppler angiography.
AB - We successfully visualized the brachiocephalic arteries and aortic arch in a
fetus seen at 19 weeks of gestation with a common arterial trunk and interrupted
aortic arch by means of color power Doppler angiography, a new diagnostic
development of color Doppler echocardiography. Power Doppler imaging is more
sensitive to the state of low flow in fetal vessels, thus providing better
visualization of fetal vascular structures from an early gestational stage.
PMID- 10695544
TI - Early onset of progressive subaortic stenosis after complete repair of tetralogy
of Fallot.
AB - Tetralogy of Fallot is often found in association with a wide variety of other
cardiac lesions, but is rarely found in association with lesions causing
obstruction to the left ventricular inflow or outflow. Subaortic stenosis has
only rarely been reported in association with tetralogy of Fallot. We report a
patient with Marfan syndrome who underwent repair of tetralogy of Fallot at five
years of age. Discrete and progressive subaortic stenosis developed two years
after the surgical correction, in a previously normal and unobstructed left
ventricular outflow tract. Surgical removal of the acquired fibrous subaortic
shelf was successful. Clinical signs of obstruction within the left ventricular
outflow tract after surgical repair of tetralogy of Fallot should prompt further
investigation to exclude the onset of acquired subaortic stenosis.
PMID- 10695545
TI - A most peculiar coronary circulation in a patient with pulmonary atresia and
intact ventricular septum.
AB - A patient with pulmonary atresia and intact ventricular septum was found to have
a right ventricular-dependent coronary circulation. In this infant both coronary
arteries lacked their normal proximal connection with the aorta, perhaps the most
egregious form of this prejudicial coronary circulation. Even more interesting
was a direct collateral vessel originating from the descending thoracic aorta and
connecting with the coronary circulation. This patient has undergone bilateral
modified Blalock-Taussig shunts, and left ventricular function seems preserved.
PMID- 10695546
TI - Complete surgical resection of intrapericardial teratoma in a neonate with
compression of the central airways.
AB - Intrapericardial teratoma is a rare but recognised cause of respiratory distress
in neonates. Patients often present with the compressive effects of the mass
within the thorax. Prompt diagnosis should be followed swiftly by surgical
resection. We report an unusual case of intrapericardial teratoma in a neonate
presenting with collapse of the lung which was successfully treated by surgery.
PMID- 10695547
TI - Anterograde double-balloon valvoplasty for treatment of severe valvar aortic
stenosis in a preterm baby weighing 1400 grams.
AB - We describe our treatment of a premature baby born weighing 1400 g with severe
aortic stenosis, with a gradient of 80 mmHg across the valve. Efforts to advance
a 6 mm angioplasty catheter into the stenotic aortic valve via the left ventricle
failed. Anterograde angioplasty, instead, was performed using two 4 mm coronary
angioplasty catheters. Six months subsequent to the intervention, the pressure
gradient measured 25 mmHg, and there was no hemodynamically significant aortic
insufficiency.
PMID- 10695548
TI - Tetralogy of Fallot associated with scimitar syndrome.
AB - We present a case of tetralogy of Fallot associated with Scimitar syndrome. The
patient was an 11-month old female who underwent successfully total repair of her
lesion, including rerouting of the anomalous pulmonary vein to the left atrium.
The diagnosis was suspected from the chest x-ray and echocardiography, and
confirmed by angiography. To the best of our knowledge only 2 additional cases
have previously been reported.
PMID- 10695549
TI - Images in congenital heart disease. Transient intimal aneurismal formation during
an aortogram using a pigtail catheter.
PMID- 10695550
TI - Guidelines for training in paediatric cardiology.
PMID- 10695551
TI - Role of Helicobacter pylori infection in extragastroduodenal disorders:
introductory remarks.
AB - Numerous studies initiated by Warren and Marshall in 1982 confirmed the crucial
role of H. pylori infection in the pathogenesis of gastritis, peptic ulcer and
possibly also gastric cancer leading to reappraisal of fundamental concept of
gastric pathophysiology. These topics were covered, in part, by our previous H.
pylori-related symposium I (1995), II (1997) and III (1999) organized in Cracow.
H. pylori is one of the most frequent causes of gastroduodenal infection
worldwide, resulting in the release of various bacterial and host dependent
cytotoxic substances including ammonia, platelet activating factor (PAF),
cytotoxins and lipopolysaccharides (LPS) as well as cytokines such as
interleukins (IL)-1-12, tumor necrosis factor alpha (TNF(alpha), interferon gamma
(INFgamma) and reactive oxygen species (ROS). Recently, several extradigestive
pathologies have been linked to H. pylori infection including cardiovascular,
cutaneous, autoimmune, esophageal and other diseases such as sideropenic anemia,
growth retardation, extragastric MALT-lymphoma etc. The potential role of H.
pylori infection in the pathogenesis of these extradigestive disorders has been
based on facts that 1) local gastric inflammation may exert systemic effects, 2)
chronic infection of gastric mucosa induces immune responses that are able to
cause the lesions remote to primary site of infection and 3) H. pylori
eradication improves the extradigestive disorders. The aim of present III
International Symposium is to provide critical reviews based on personal
experience and the available literature about extragastric manifestations of H.
pylori infection. The ultimate goal of this symposium is to foster
interdisciplinary research and exchange of opinion about the possible involvement
of H. pylori in extradigestive pathologies.
PMID- 10695552
TI - Helicobacter pylori associated gastric pathology.
AB - Helicobacter pylori (HP), undoubtedly, the most common world-wide infection plays
an important role in pathogenesis of peptic ulcer. Proof for a causal role for HP
in peptic ulcer rests in two major points; 1) the majority of ulcer patients are
HP infected and the prevalence of this infection for both gastric ulcer (GU) and
duodenal ulcer (DU) is much higher than for gender- and age-adjusted controls and
2) the cure of HP infection dramatically reduces ulcer recurrence. Conclusions
regarding the mechanisms by which HP induces peptic ulcer are restricted mainly
to studies observing the consequences of its eradication by antibiotics combined
with gastric inhibitors or bismuth agents. Several specific virulence factors
such as cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) as
well as other noxious substances including ammonia, lipopolysaccharide
(endotoxin), platelet activating factor (PAF), nitric oxide (NO) and others have
been implicated in gastritis and were found to be significantly more frequent in
gastric cancer than in gender- and age-matched controls, especially in younger
generation. Chronic inflammation, atrophic gastritis, intestinal metaplasia,
impaired defense mechanisms combined with hypergastrinemia, deficiency of vitamin
C in the stomach , excessive oxygen metabolites and epithelial cell proliferation
have been associated with gastric cancer. This multi-step pathway originally
proposed by Correa and his colleagues, long before the HP was discovered in the
stomach, leads to cancer but may be reversed by eradication of HP. This is,
however, a controversial issue because gastric atrophy and intestinal metaplasia
may be also caused by other factors such as bile reflux, dietary irritants, and
autoimmunity. The implication of HP in MALT-lymphoma is based on the observations
that eradication of HP in early stage of low-grade of this tumor leads to
complete remission. The significance of HP in non-ulcer dyspepsia remains
questionable and requires further studies.
PMID- 10695553
TI - Epidemiology of Helicobacter pylori: transmission, translocation and extragastric
reservoirs.
AB - Although H. pylori infection is endemic and despite more than 10 years of
research, the mode and route of transmission remain elusive. This may, in part,
be due to the inherent problems of detecting H. pylori noninvasively. The
prevalence of infection varies between countries and is closely related to Growth
Domestic Product. An age-cohort effect and data from longitudinal studies suggest
that the incidence of infection is much higher in children than adults. In
developing countries the prevalence of infection is often more than 80% in young
adults, in contrast to less than 10% for similar age groups in developed
countries. The observations of mosaicism (in the VacA gene) and a panmycytic
population structure imply exchange of genetic material either in or outside of
the host, which is supported by the increasing recognition of polyclonal
infection and suggests that secondary infection occurs after primary acquisition.
In addition, in children persistent primary infection may sometimes occur only
after previous (repeated) exposure and/or transient colonisation of the gastric
mucosa. H. pylori and other gastric Helicobacter spp are always noninvasive, but
other human nongastric Helicobacter spp have sometimes been isolated from the
systemic circulation in immunocompromised patients. For nonhuman hosts,
intestinal Helicobacter spp are thought to translocate more frequently from the
colon to the liver. Within the human host, the oral cavity is the principal
extragastric reservoir, although case reports suggest that H. pylori may
sometimes be found beyond the 2nd part of the duodenum. The hypothesis that H.
pylori is a zoonosis or transmitted as coccoid forms by a vector (pets,
houseflies) is not supported by recent research showing that H. pylori is
entirely unable to support an aerobic or anaerobic metabolism and that coccoid
forms are non-viable. H. pylori is primarily acquired in infancy, most probably
via the oroorogastric route, from other family members or close contacts
encountered after weaning or socialisation. Further studies to support or refute
this hypothesis are required.
PMID- 10695554
TI - Epidemiological study on Helicobacter pylori infection and extragastroduodenal
disorders in Polish population.
AB - An association between Helicobacter pylori (H. pylori) infection and
extragastroduodenal disorders (EGDD) is still not clear. The aim of the study was
to investigate the relationship between H. pylori infection and the symptoms of
coronary artery disease (CAD), facial dermatological changes (FDC),
gastroesophageal reflux diseases (GERD), and periodontal diseases (PD) in Polish
population. The study was performed between 1996-1999 year on 7,060 adult
inhabitants of municipal area of Krakow (aged 18-76, mean 46.3 year; 55.8%
female, 44.2% male): 2,204 subjects with EGDD and 4,856 without symptoms of EGDD.
Each patient responded to a detailed questionnaire under supervision of medical
staff. The H. pylori status was assessed non-invasively using urea breath test
(UBT) with capsulated low-dose 13C-UBT (38 mg). Exclusion criteria were: recent
H. pylori eradication, treatment with PPI, bismuth and/or antibiotics in the last
4 weeks. Four groups of cases with EGDD symptoms were selected. Within each group
exclusively only one of studied symptoms was recorded. The study included 328,
138, 688, and 1,050 patients with CAD, FDC, GERD and PD, respectively. For each
studied group an age and sex-matched asymptomatic controls were selected (897,
387, 1,083, and 2,489 control patients). RESULTS: Overall H. pylori infection
rate was 69,9% (in 71.4% of 2,204 cases and in 69.31% of 4,856 controls). In CAD
group: 68% of 328 cases were H. pylori (+ve) vs. 70% H. pylori (+ve) of 897
controls. An association was not significant: OR = 0.93 (95% CI, 0.72-1.20). In
138 of FDC cases, 59% were H. pylori (+ve) vs. 71% H. pylori (+ve) in 387
controls showing the lack of positive association; OR = 0.60 (95% CI, 0.42-0.87).
In GERD, 69% of 688 cases were H. pylori (+ve) vs. 73% of 1,083 H. pylori (+ve)
controls and negative association was observed; OR=0.80 (95% CI, 0.65-1.00). In
1,050 of PD cases 75% were H. pylori (+ve) vs. 68% H. pylori (+ve) of 2,489
controls; positive association was significant; OR = 1.4 (95% CI, 1.16-1.68). We
conclude that in the studied Polish population, no positive association exists
between H. pylori positivity and CAD, FDC or GERD possibly due very high overall
H. pylori infection rate. The only positive link observed between H. pylori
infection and periodontal disease may reflect direct "in situ" H. pylori
pathological action of H. pylori in oral cavity. It is not excluded that
periodontal diseases may facilitate the H. pylori oro-gastric transmission and
colonisation of the bacteria in the digestive tract.
PMID- 10695555
TI - The role of Helicobacter pylori in cardiovascular and cerebrovascular diseases.
AB - Classical risk factors for cardiovascular and cerebrovascular diseases do not
fully coincide with the prevalence of these conditions. Emerging evidences show
that new factors may be predisposing for the development of ischemic events. It
has been demonstrated that atherosclerosis has a strong inflammatory background;
such state of chronic inflammation may be related to the presence of persistent
infectious agent. Helicobacter pylori (H. pylori), among other microorganisms,
has been extensively investigated for its possible role. Many molecular
mechanisms have been hypothesized to explain its eventual action. Epidemiological
studies do not exclude a correlation between the infection and cardiovascular and
cerebrovascular diseases. Many confounding factors, however, make difficult a
definitive evaluation of the huge number of data present in the literature.
Moreover, various therapeutic studies have been attempted to show if antibiotic
treatment improves prognosis in patients affected by ischemic heart disease.
Still, none of these trials focused specifically on the effects of H. pylori
eradication on the clinical progression of vascular lesions.
PMID- 10695556
TI - Association of Helicobacter pylori infection with coronary heart disease.
AB - The role of Helicobacter pylori (HP) as the main etiological factor in gastritis
and peptic ulcer disease is undisputable. Gastric mucosal damage caused by HP
involves various bacterial and host-dependent toxic substances that have been
recently associated with an increased risk of coronary artery disease (CAD),
possibly through the activation acute phase response and of procoagulant
hemostatic factors. Recent studies showed a close and strong correlation between
plasma increments of some cytokines such as IL-6 or TNFalpha and cardiovascular
diseases. HP infection induces platelet activation and aggregation that could be
the pathogenic explanation of the association between HP infection and CAD. The
aim of this study was to determine the seroprevalence of HP infection and
antibodies to CagA, an antigen that is expressed by the most virulent HP strains
inducing an enhanced gastric inflammatory response, in patients undergoing
routine coronary artery examination. We studied 76 patients with CAD and 81
healthy controls patients without significant change in coronary circulation.
Angiograms were read by two independent experienced cardiologists blinded to the
results of HP status. The presence of serum IgG antibodies to HP and to CagA and
plasma interleukin-8 (IL-8) levels was measured by ELISA. In addition plasma C
reactive protein fibrinogen, total cholesterol and lipids levels were measured in
all studied patients. Seropositivity to HP was found in 81.5 % of cases and in
51% of controls and the difference in prevalence was statistically significant,
the odds ratio being 4.3 for Hp patients. Antibody to CagA protein was detected
in 47.3% of CAD but only in 28% of healthy controls (OR = 2.3 vs OR = 10). C
reactive protein, plasma fibrinogen and total cholesterol were, respectively
higher in patients with CAD than in controls. Present data show that there is
significant link between CAD and HP infection. The HP infection significantly
increases the risk of CAD, especially when both the anti-HP IgG and anti-CagA IgG
are considered. Higher prevalence of cytotoxic HP strains might enhance the
atherosclerotic process by inducing a persistent, low grade inflammatory response
in arterial wall with enhanced synthesis of acute phase reactants.
PMID- 10695557
TI - Helicobacter pylori infection and skin diseases.
AB - There is increasing evidence for systemic effects of gastric H. pylori infection
which may result in extragastrointestinal disorders. This review summarizes the
available medical literature up to September 1999, identified through a MEDLINE
research including own studies, regarding H. pylori and skin diseases. Due to
current knowledge best evidence for a potential link of H. pylori infection
exists for chronic urticaria although the data are still conflicting. Thus, the
search for H. pylori should be included in the diagnostic management of chronic
urticaria. With regard to other skin diseases such as rosacea, hereditary or
acquired angioedema due to C1-esterase inhibitor deficiency, systemic sclerosis,
Schonlein-Henoch purpura, Sjogren's syndrome, sweet's syndrome, and atopic
dermatitis only single of few cases have been reported so far. Thus, we clearly
need further randomized, double-blind and placebo-controlled studies including
adequate diagnostic schedules, sufficient eradication treatment protocols,
confirmation of eradication, and adequate control groups to establish a role of
H. pylori in skin diseases. Caution must be taken not to accuse H. pylori as the
infectious agent responsible for every disease, particularly since H. pylori
infection is very common. Although from an epidemiological and morphological view
the skin diseases to which H. pylori has been linked seem to be completely
different it is striking that in most of them an autoimmune pathogenesis is
suspected or considerable vascular impairment can be found.
PMID- 10695558
TI - Helicobacter pylori and its eradication in rosacea.
AB - Rosacea is a common condition of unknown etiology usually accompanied by
gastrointestinal symptoms and favorably responding to the treatment with
antibiotics. This study was designed to examine the prevalence of gastric
Helicobacter pylori (Hp) infection verified by 13C-UTB-test, CLO, Hp culture and
serology (IgG) in patients with rosacea. Gastroduodenoscopy was combined with
pentagastrin secretory test and antral and fundic biopsy samples were taken for
histological evaluation (the Sydney system). Blood samples were also taken for
the determination of plasma gastrin using RIA and plasma interleukin (IL)-8 and
tumor necrosis factor alpha (TNFalpha) using ELISA. This study was performed in
60 patients, 31-72 year old, with visible papules and pustules associated with
erythema and flushing on the face and on 60 age- and gender-matched patients
without any skin diseases but with similar as in rosacea gastrointestinal
symptoms but without endoscopic changes in gastroduodenal mucosa (non-ulcer
dyspepsia - NUD). The Hp prevalence in rosacea patients was about 88 % as
compared to 65% in control NUD patients. Among rosacea patients, 67% were
cytotoxin associated gene A (CagA) positive, while in NUD patients only 32% were
CagA positive. Rosacea patients showed gastritis with activity of about 2.1 in
antrum and 0.9 in the corpus of the stomach while those with NUD only mild
gastritis with activity of approximately 1.0) confined to the antrum only.
Following initial examination, typical 1 wk anti-Hp therapy including omeprazole
(20 mg bd.), clarithromycin (500 mg bd.) and metronidazol (500 mg bd.) was
carried out. After eradication, 51 out of 53 treated rosacea patients became Hp
negative. Within 2-4 weeks, the symptoms of rosacea disappeared in 51 patients,
markedly declined in 1 and remained unchanged in 1 other subject. A dramatic
reduction in activity of gastritis (to 0.3 in antrum and to 0.1 in corpus) was
observed. Basal plasma gastrin decreased from 48 +/- 5 pM before to 17+/-3 pM
after eradication, while pentagastrin-induced maximal (MAO) declined,
respectively, from about 16.6 +/- 4.2 to 8.5 +/- 1.8 mmol/h. Plasma TNFalpha and
IL-8 were reduced after the therapy by 72% and 65%, respectively. We conclude
that: 1) Rosacea is a disorder with various gastrointestinal symptoms closely
related to gastritis, especially involving the antrum mucosa, with Hp expressing
cagA in the majority of cases and elevated plasma levels of TNFalpha and IL-8; 2)
The eradication of Hp leads to a dramatic improvement of symptoms of rosacea and
reduction in related gastrointestinal symptoms, gastritis, hypergastrinemia and
gastric acid secretion; and 3) Rosacea could be considered as one of the major
extragastric symptoms of Hp infection probably mediated by Hp-related cytotoxins
and cytokines.
PMID- 10695559
TI - Helicobacter pylori lipopolysaccharide-mediated gastric and extragastric
pathology.
AB - Lipopolysaccharides (LPS) are a family of toxic phosphorylated glycolipids in the
outer membrane of Gram-negative bacteria, including Helicobacter pylori, and are
composed of a lipid moiety (termed lipid A), a core oligosaccharide, and a
polymeric O-specific polysaccharide chain. Compared with LPS of other bacteria,
H. pylori LPS and lipid A induce low immunological activities in a range of test
systems. Nevertheless, these reduced levels of LPS-induced cytokines and toxic
oxygen radicals can contribute, with those induced by bacterial proteins, to the
H. pylori-associated inflammatory response. Whether the ability of H. pylori LPS
to induce low production of both procoagulant activity and plasminogen activator
inhibitor type 2 by human mononuclear cells contributes to localized inflammatory
responses alone and, in addition, play a role in extragastric pathology remains
an open question. The core oligosaccharide of H. pylori LPS, in part with a 25
kDa protein adhesin, mediates the binding of the bacterium to the host
glycoprotein laminin, and hence interferes with gastric cell receptor-laminin
interaction in the basement membrane. Also affecting mucosal integrity, the core
sugars of certain H. pylori strains, particularly those associated with gastric
ulceration, have been implicated in pepsinogen induction, but this is a strain
dependent phenomenon. Of particular interest, the O-chains of a large proportion
of H. pylori strains mimic Lewis (Le) antigens. Although investigations have
focussed on the role of these antigens in H. pylori-associated autoimmunity,
which remains to be unequivocally established, other pathogenic consequences of
Lewis mimicry are becoming apparent. Expression of Lewis antigens may be crucial
for H. pylori colonization and adherence and, by aiding bacterial interaction
with the gastric mucosa, thereby aid delivery of secreted products, and hence
influence the inflammatory response.
PMID- 10695560
TI - Immunology of Helicobacter pylori infection.
AB - We have tried to answer several questions in this article, dealing with:
ontogenesis of the immune response, presentation of H. pylori antigens to immune
cells, systemic vs local immune response, cytokine Th1/Th2 configuration, the
role of cytokines, especially represented during H. pylori infection, mimicry
phenomena, extragastroduodenal sites and manifestations and finally, vaccine
development. The new achievements in the vaccine field, also of Polish groups,
were underlined.
PMID- 10695561
TI - The infection by Helicobacter pylori strains expressing CagA is highly prevalent
in women with autoimmune thyroid disorders.
AB - H. pylori infection is putatively associated with extra-digestive disorders and
may also play a role in the development of autoimmune thyroid diseases (ATD). It
was recently found that monoclonal antibodies to an H. pylori strain with cagA
positivity reacted with follicular cells of the thyroid gland, and that an H.
pylori organism possessing the cag pathogenicity island carried a gene encoding
for an endogenous peroxidase. The aims of this study was (1); To ascertain
whether the infection by strains endowed with an increased inflammatory potential
(those expressing CagA) could further enhance the risk of developing ATD (2); To
verify the possible existence of an immune cross-reactivity between
autoantibodies to peroxidase and thyroglobulin and H. pylori antigens (3). To
establish whether thyroid colloid antigens could cross-react with an anti-H.
pylori serum. The study was partly designed retrospectively. We examined 41
consecutive women with ATD, and, as a control, 33 consecutive age- and socio
economic class-matched women without autoimmune thyroid disorders, living in the
same area as patients, occurred at the same institution in the same period (six
months). Both patients and controls were examined serologically for H. pylori
infection and CagA status by Western blotting. Some serum samples were absorbed
with H. pylori to determine whether the antibody levels decreased. Colloid
proteins were resolved electrophoretically and matched with a hyperimmune serum
raised in rabbits against a CagA-positive H. pylori. Thirty-two patients (78.0%)
tested seropositive for H. pylori infection, vs. 16 controls (48.4%) (P = 0.008,
OR = 3.78, RR = 1.61). The prevalence of anti-CagA antibodies was 71.8% in
infected patients, and 50% in infected controls (P = 0.161, n.s.). The overall
prevalence of infection by CagA-positive H. pylori was significantly higher in
patients with ATD (23/41, or 56.0%) than that in controls (8/33, or 24.2%) (P =
0.006, OR = 3.99, RR = 2.31). The other tests gave negative or inexplicable
results. IN CONCLUSION: CagA-positive H. pylori infection increases the risk of
ATD development.
PMID- 10695562
TI - CagA-positive Helicobacter pylori infection may increase the risk of food allergy
development.
AB - The aim of this study was to test whether patients with symptomatic food allergy
and significant levels of immunoglobulin E (IgE) to alimentary antigens were more
likely infected by H. pylori, especially by strains expressing the CagA protein,
with respect to controls. A group of 38 patients with symptomatic food allergy
and 53 age-matched controls were examined serologically for H. pylori infectious
status, and for CagA seropositivity. IgE to alimentary allergens were measured by
a commercial kit. The prevalence of H. pylori infection in patients with food
allergy and controls was similar (42.1%, and 48.3%, respectively). However, anti
CagA antibodies in H. pylori-infected persons were detected in 62.5% of patients
with food allergy, and 28% of controls (P = 0.030, odds ratio = 4.29). The mean
level of IgE to the most common alimentary antigens in serum samples from
infected patients with anti-CagA antibodies was significantly higher than in CagA
negative infected patients: 3.28 kU/L (SD 3.93), vs. 1.99 kU/L (SD 1.53), P =
0.002, 95% confidence interval = 0.61 to 2.53). Infection by CagA-positive H.
pylori increases the risk of developing food allergy.
PMID- 10695563
TI - The role of CagA status in gastric and extragastric complications of Helicobacter
pylori.
AB - Two major markers of virulence have been described in H. pylori. The first is a
secreted protein (VacA) that is toxic to human cells in tissue culture. This
cytotoxin causes vacuolation of epithelial cells in vitro and induces epithelial
cell damage in mice. The second is a 40-Kb pathogenicity island for which the
gene cagA (cytotoxin-associated gene A) is a marker. Approximately 60% of H.
pylori isolates in Western countries are cagA+. The protein encoded by cagA+ has
a molecular weight of 120-140 kDa and exhibits sequence heterogeneity among
strains isolated from Western and Eastern countries. Although no specific
function has been identified for CagA, there is increasing evidence that cagA+
strains are associated with increased intensity of gastric inflammation and
increased mucosal concentration of particular cytokines including interleukin 8.
Inactivation of picB (Hp 0544) or any of several other genes in the cag island
ablates the enhanced IL-8 secretion of human gastric epithelial cells in tissue
culture. Furthermore, persons colonized with cagA+ strains have an increased risk
of developing more severe gastric diseases such as peptic ulcer and distal (non
cardia) gastric cancer than those harboring cagA- strains. We investigated the
role of cagA status in both gastroduodenal and extragastroduodenal disease with
H. pylori. Among the diseases limited to the antrum and body of the stomach and
the duodenum, we demonstrated a correlation between CagA seropositivity and
peptic ulcer disease. We also showed correlation between distal gastric cancer
rated and CagA prevalence in populations in both developed and developing
countries. In addition, we found that for several Asian populations, the
relationship between CagA seropositivity and gastroduodenal diseases was complex.
For extragastroduodenal diseases, our results confirmed previous reports that
demonstrated that CagA status did not play a role in diseases such as rheumatoid
arthritis and hyperemesis gravidarum. However, we found a clear negative
association between the presence of a positive response to CagA and esophageal
diseases. Therefore, CagA seropositivity (and thus gastric carriage) is
associated with increased risks of certain diseases (involving the lower stomach
and duodenum) and decreased risks of GERD and its sequelae. This apparent paradox
can best be explained by differences in the interaction of cagA+ and cagA-
strains with their hosts.
PMID- 10695564
TI - The carcinogenic effect of H. pylori on the gastric epithelial cell.
AB - The recent demonstration in animal models that H. pylori alone may be capable of
inducing intestinal-type gastric cancer, and that H. felis can accelerate gastrin
induced gastric neoplasia has stimulated research on examining the mechanisms of
H. pylori-associated carcinogenesis in humans. Several mechanisms are currently
under investigation, including the dysregulation of the gastric epithelial cell
cycle, the formation of DNA adducts, the generation of free radicals, alterations
in growth factor secretion and cytokines, and the effects of decreased gastric
acid secretion. This review will examine the relevant evidence acquired from
human tissue studies, animal models and cell culture systems in an attempt to
explore these pathways, and to evaluate the mechanisms by which H. pylori may
cause gastric cancer.
PMID- 10695565
TI - Role of gastrin in gastric cancerogenesis in Helicobacter pylori infected humans.
AB - Numerous epidemiological studies demonstrated the association between
Helicobacter pylori (H. pylori) infection and gastric cancer but the mechanism of
the involvement of H. pylori in gastric cancerogenesis remains virtually unknown.
This study was designed to determine the seropositivity of H. pylori and
cytotoxin associated gene A (CagA), serum gastrin and gastric lumen gastrin
levels under basal conditions and following stimulation with histamine in gastric
cancer patients and controls. 100 gastric cancer patients aging from 21 to 60
years and 300 gender- and age-adjusted controls hospitalized with non-ulcer
dyspepsia (NUD) entered this study. 13C-Urea Breath Test (UBT), serum
immunoglobulin (IgG) antibodies to H. pylori and CagA were used to assess the H.
pylori infection and serum levels of IL-1beta, IL-8 and TNFalpha were measured by
enzyme-linked immunosorbent assay (ELISA) to evaluate the degree of gastric
inflammation by H. pylori . Gastrin-17 mRNA and gastrin receptors (CCK(B)) mRNA
expression in gastric mucosal samples taken by biopsy from the macroscopically
intact fundic and antral mucosa as well as from the gastric tumor was determined
using RT-PCR. The overall H. pylori seropositivity in gastric cancer patients at
age 21-60 years was about 92%, compared, respectively, to 68%, in controls. A
summary odds ratio (OR) for gastric cancer in H. pylori infected patients was
about 5.0 . The H. pylori CagA seropositivity in gastric cancer patients was
about 58.5% compared to 32.4% in controls, giving the summary OR for gastric
cancer in CagA positive patients about 8.0. The prevalence of H. pylori- and H.
pylori CagA-seropositivity was significantly higher in cancers than in controls,
irrespective of the histology of gastric tumor (intestinal, diffuse or mixed
type). Median IL-1beta and IL-8 reached significantly higher values in gastric
cancer patients (9.31 and 30.8 pg/ml) than in controls (0.21 and 3.12,
respectively). In contrast, median serum gastrin in cancers (as total group) was
several folds higher (62.6 pM) than in controls (19.3 pM). Also median luminal
gastrin concentration in gastric cancer patients was many folds higher (310 pM)
than in controls (20 pM). This study shows for the first time that cancer
patients are capable of releasing large amounts of gastrin into the gastric lumen
to increase luminal hormone concentration to the level that was recently reported
to stimulate the growth of H. pylori. There was no any correlation between plasma
gastrin levels and gastric luminal concentration of gastrin suggesting that: 1)
luminal gastrin originates from different source than plasma hormone, most
probably from the cancer cells, 2) cancer cells are capable of expressing gastrin
and releasing it mainly into the gastric juice and 3) the gastric cancer cells
are equipped with gastrin-specific (CCK(B)) receptor so they exhibit the self
growth promoting activity in autocrine fashion. This notion is supported by
direct detection of gastrin mRNA and gastrin receptor (CCK(B)-receptors) mRNA
using RT-PCR in cancer tissue. To our knowledge this is the first study showing
an important role of gastrin as self-stimulant of cancer cells in patients
infected with H. pylori. Basal and histamine maximally stimulated acid outputs
were significantly lower in gastric cancer patients than in controls despite of
enhanced gastrin release, particularly in cancer patients and this might reflect
the mucosal inflammatory changes (increased serum levels of proinflammtory
interleukins - IL-1beta and IL-8), that are known to increase gastrin release. We
conclude that: 1) H. pylori infected patients, particularly those showing CagA
seropositivity, are at greatly increased risk of development of gastric cancer,
2) H. pylori-infected cancer patients produce significantly more IL-1beta and IL
8 that might reflect an H. (ABSTRACT TRUNCATED)
PMID- 10695566
TI - Detection of Helicobacter in the liver of patients with chronic cholestatic liver
diseases.
AB - Helicobacter species were identified in human liver tissues by PCR. Biopsies were
obtained from patients with primary sclerosing cholangitis, primary biliary
cirrhosis and noncholestatic liver cirrhosis. One set of Helicobacter genus
specific primers and two different primer sets for Helicobacter pylori were used
in the PCR-assays. Using Helicobacter genus-specific primers 80% (8/10) of
patients with primary sclerosing cholangitis and 90% (9/10) of patients with
primary biliary cirrhosis were positive. Seven of these 17 samples were positive
using two different primers for H. pylori and Southern blot hybridization. Among
the non-cholestatic liver cirrhosis controls, only one sample was positive in the
Helicobacter genus-specific PCR-assay. Significantly higher values of alkaline
phosphatases and prothrombin complex was found for the patients positive for
Helicobacter genus. In conclusion, gene sequences of Helicobacter species and H.
pylori were detected in human liver tissue using PCR and DNA hybridization in
patients with a cholestatic liver disease, but rarely in noncholestatic liver
cirrhosis.
PMID- 10695567
TI - Preventing traumatic brain injury: an innovative approach to outcomes assessment.
AB - The purpose of this study was to investigate the usefulness of the state traffic
violations database as an outcome measure for the Young Traffic Offenders
Programme, a 1-day educational injury prevention programme for young people with
speeding offences. The database provided a fine-grained, cumulative record of
each driver's traffic offences and sanctions applied. A comparison of 92
programme participants and 87 non-treated individuals showed no significant
between-group difference in rate of convictions after the target programme date,
but each group declined significantly in rate of convictions over time. Younger
males and individuals with a higher number of convictions initially were more
likely to have higher conviction rates after the target date. These findings
underscore the need to improve prevention programmes and highlight the potential
usefulness of existing public datasets for outcome evaluation.
PMID- 10695568
TI - Cognitive orientation in rehabilitation and neuropsychological outcome after
traumatic brain injury.
AB - This study evaluated the ability of the Orientation Log (O-Log) to predict
cognitive outcome at rehabilitation discharge, as well as future
neuropsychological outcome. The hypothesis was that patients who demonstrated
better orientation upon admission would achieve superior functional cognitive
outcome at discharge and on subsequent neuropsychological assessment. Sixty
individuals receiving inpatient rehabilitation following a new-onset TBI
participated. Orientation data was collected using the O-Log during morning
bedside rounds. Outcome data was collected at 6 and 12 months post-injury.
Significant correlations were found between the O-log and measures of memory,
executive functioning, basic verbal skills, and estimated intellectual ability.
When compared to the other predictor variables, step-wise multiple regression
analyses revealed that the minimum O-Log score was the primary significant
predictor of performance on six neuropsychological and functional outcome
measures. Results of this study suggest that evaluating orientation with the O
Log during acute rehabilitation may reflect level of injury severity and aid in
predicting cognitive outcome.
PMID- 10695569
TI - Cultural variations in the understanding of traumatic brain injury and brain
injury rehabilitation.
AB - Little is known about how people from different cultures experience and
understand traumatic brain injury (TBI) and the process of brain injury
rehabilitation. The Brain Injury Rehabilitation Unit (BIRU) undertook a
qualitative project to research cultural variations in the understanding of TBI
and the rehabilitation process, interviewing 39 people with TBI and family
members from Italian, Lebanese and Vietnamese backgrounds. The focus was on the
reporting of sequelae of the TBI; valued qualities of service providers; barriers
to effective communication; the role of the families in the rehabilitation
process; and the experience of social stigma. Findings suggest there is a
universal experience of TBI that transcends individual cultures. Study
participants valued attentiveness, friendliness and guidance from rehabilitation
staff. Family support was not always available to the person with TBI due to
family conflict. Generally, people with TBI and family members valued the
assistance of health interpreters facilitating their communication with
rehabilitation staff. People with TBI from all three cultures experienced
problems of stigma and social isolation. The findings have a number of
implications for how brain injury rehabilitation staff can approach service
provision to people from diverse cultural backgrounds.
PMID- 10695570
TI - Sitting balance following brain injury: does it predict outcome?
AB - Balance dysfunction is commonly observed following traumatic brain injury. There
are many proposed predictors of functional outcome in the traumatic brain injury
population. It was hypothesized that the degree of balance dysfunction on
admission to rehabilitation would be a significant predictor of the need for
assistance at discharge, as measured by the Functional Independence Measure
(FIM). This study involved 237 cases of traumatic brain injury patients admitted
to a rehabilitation unit between November 1989 and September 1996. Using a
multiple regression model, controlling for age, initial Glasgow Coma Score (GCS),
rehabilitation admission strength, sitting balance and standing balance, it was
found that the degree of impairment in sitting balance at admission to
rehabilitation was a significant predictor of Discharge FIM-Total (FIM-T) score
(p < 0.0001) and also of selected elements from the Discharge FIM-Motor (FIM-M)
score (p < 0.0005). The combination of age, initial admission GCS, rehabilitation
admission strength, standing balance and sitting balance accounted for 29% of the
variance in the Discharge Total FIM score. Among these, sitting balance was the
second most powerful predictor of both selected elements of the Discharge FIM
motor score and discharge FIM-T. Sitting balance predictive capacity was exceeded
in power only by age. Impairments in sitting balance appear to have a significant
impact on functional outcome. Emphasis on unique rehabilitation techniques to
treat balance dysfunction in the adult TBI population is warranted.
PMID- 10695571
TI - Kinematic analysis of tongue movements in dysarthria following traumatic brain
injury using electromagnetic articulography.
AB - Electromagnetic articulography (EMA), a technique that uses alternating magnetic
fields to track the movement of miniature receiver coils affixed to the
articulators, was used to assess the speed and accuracy of tongue movements
exhibited by an individual with dysarthria following severe traumatic brain
injury (TBI). Three receiver coils were attached to the TBI subject's tongue and
the movements of these coils were recorded during five productions of three
single syllable real words consisting of the lingual consonants /t, s, k/ in the
word-initial position. A non-neurologically impaired adult male served as a
control subject. A range of kinematic parameters was analysed from the consonant
productions including the movement trajectories, velocity, acceleration,
distance, and duration of tongue movements. Examination of the complex
interactions between the kinematic parameters recorded for the TBI subject
revealed a disturbance in the 'control' of tongue speed rather than a disturbance
in speed per se, as it was found that the TBI subject exhibited difficulty in
decelerating his tongue movements appropriately on the approach up to the palate
during consonant production. The difficulty noted in deceleration resulted in
inaccurate tongue movements that overshot the point of intent (in the case of
/t/) and may have been instrumental in reducing the length of time that the
tongue remained at the palate (in the case of /s/ and /k/) in comparison to the
control subject. The disturbances identified in the kinematic parameters recorded
provided objective insights into the nature of the articulatory disturbances
responsible for the deviant speech feature, consonant imprecision, perceived in
the TBI subject's speech. The study stresses the importance of examining a range
of kinematic parameters and the interactions between these parameters in
attempting to determine the nature of articulatory disturbances exhibited by
individuals with dysarthria following TBI.
PMID- 10695572
TI - Coping style and post-traumatic stress disorder following severe traumatic brain
injury.
AB - There is increasing evidence that a proportion of severe traumatically brain
injured (TBI) patients do suffer post-traumatic stress disorder (PTSD). The aim
of this study was to investigate the predictors of PTSD following severe TBI in a
sample of 96 patients who sustained a severe TBI, of whom 27% satisfied
diagnostic criteria for PTSD. The Post-traumatic Stress Disorder Interview, the
Coping Style Questionnaire, and the Functional Assessment Measure was
administered to these patients 6 months after hospital discharge. Avoidant coping
style, behavioural coping style, and a history of prior unemployment were the
significant predictors of PTSD severity. These findings indicate that reduction
of PTSD and management of severe TBI may be facilitated by teaching patients more
adaptive coping strategies.
PMID- 10695573
TI - Emergency department visits associated with traumatic brain injury: United
States, 1995-1996.
AB - The purposes of this study were to provide a national estimate of the incidence
of traumatic brain injuries (TBIs) seen in emergency departments (EDs), but not
requiring hospitalization and to determine the causes of these injuries. Using
the Centers for Disease Control and Prevention case definition of TBI, ED data
was analysed from the National Hospital Ambulatory Medical Care Survey (1995
1996). The average overall incidence rate of TBI-related ED visits for persons
who were not hospitalized was 392/100,000 population per year, or 1,027,000
visits to hospital EDs in the US each year. This estimate is nearly twice (392
vs. 216) the previously estimated incidence rate, which was based on data from
the 1991 National Health Interview Survey Injury Supplement. It was found that
the highest incidence rate occurred among children aged 0-14 years, the rate for
males was higher than for females, and the primary reported causes of these
injuries were 'falls', motor vehicle-related causes, and 'struck by an object'.
Although often considered 'mild' TBIs, these injuries can lead to significant
cognitive and emotional impairment. Thus, continued surveillance of TBI-related
ED visits is an important part of a comprehensive TBI prevention strategy.
PMID- 10695574
TI - Electronic memory aids for outpatient brain injury: follow-up findings.
AB - The introduction of highly portable computers extends the range of tools
potentially useful to persons with functional impairments of prospective memory
resulting from brain injury. This study reviews the experience of 12 patients
with brain injury undergoing outpatient treatment using palmtop computers to
assist with memory dependent activities in their everyday lives. During the
initial supervised trial period, each was provided a palmtop computer based
memory aid capable of generating audible and visible reminder cues. Subsequently,
patients were contacted for follow-up between 2 months and 4 years after initial
trial usage, and surveyed as to the utility of the computer. Nine patients found
palmtop computers were useful during supervised trials. Seven of nine patients
actually continued to use such devices after the usage trials had ended.
Experience with this technology has shown it to be useful in a high proportion of
patients for assisting with memory dependent functions.
PMID- 10695575
TI - Neuropsychological assessment of a potential "euthanasia" case: a 5 year follow
up.
AB - McMillan reported a neuropsychological assessment procedure which was used to
determine whether or not there was evidence for sentience in a young woman who
had been rendered tetraplegic and anarthric as a result of a road traffic
accident. An application to court had been made to withdraw feeding and this was
supported by medical evidence which gave the view that the individual was
functioning little beyond vegetative state, had a poor quality of life and had
little prospect of further recovery. Evidence for an ability to communicate
reliably was found including for a wish to continue living, and as a consequence
the application to court was withdrawn. This paper describes further recovery 2-4
years after the original assessment (i.e. 4-6 years post-injury). At follow-up,
she remained dependent for all care, but was now feeding orally and was talking.
She could learn new information, some of which she retained for at least 12
months and had greater insight into her condition. She now reported low mood and
some pain. As before, she consistently reported a wish to live. The implications
of the follow-up are discussed in the context of assumptions made about quality
of life and decision making about euthanasia in brain injured people who are
severely disabled, but are not in a vegetative state.
PMID- 10695576
TI - Hypercholesterolemia in children.
PMID- 10695577
TI - Family physicians should be experts in palliative care.
PMID- 10695578
TI - Neurologic complications of Epstein-Barr virus infection.
PMID- 10695579
TI - Patient compliance: in search of the real question in diabetes care.
PMID- 10695580
TI - Comment on the family physician as hospitalist.
PMID- 10695581
TI - Dietary therapy for children with hypercholesterolemia.
AB - Accumulating evidence clearly shows that atherosclerosis begins in youth. The
National Cholesterol Education Program (NCEP) has recommended that children at
high risk of developing coronary artery disease as adults be screened so that
those with elevated low-density lipoprotein (LDL) cholesterol levels can be
treated, primarily by modification of diet. The initial approach to these
youthful patients is to use the NCEP step I diet. This diet provides calories and
nutrients that support normal growth and development, but limits saturated fat
and total fat intake to no more than 10 and 30 percent of total calories,
respectively, and cholesterol intake to no more than 100 mg per 1,000 kcal per
day, to a maximum of 300 mg. If the goal of reducing the LDL cholesterol level to
below 130 mg per dL (3.35 mmol per L) is not achieved, the more restrictive step
II diet should be initiated. However, the step II diet may not provide sufficient
calories and nutrients to support normal growth and development; therefore,
trained nutritionists may be required to effectively manage a child on this diet.
PMID- 10695582
TI - Evaluation of overuse elbow injuries.
AB - The evaluation of elbow pain can be challenging because of the complexity of the
joint and its central location in the upper extremity. Diagnosing the injury
correctly requires an understanding of the anatomy of the elbow, which includes
three articulations, two ligament complexes, four muscle groups and three major
nerves. The history should be directed at pinpointing the location of symptoms
and the activities that cause the patient's pain. It is important to identify the
specific musculotendinous structures that are at risk for overuse or have been
injured through overuse. Mechanical symptoms are indicative of intra-articular
pathology, whereas neurologic symptoms are characteristic of nerve entrapment
syndromes. Physical examination of the elbow and related structures should
confirm the diagnosis. Only a minority of patients require diagnostic studies.
Basic treatment principles are described by the acronym PRICEMM: protection,
rest, ice, compression, elevation, medication and modalities (physical therapy).
Surgical consultation is warranted in selected patients.
PMID- 10695583
TI - Recognizing an index case of tuberous sclerosis.
AB - Tuberous sclerosis is the most common neurocutaneous syndrome after
neurofibromatosis. Dermatologic manifestations may be the only clues the family
physician has to the diagnosis of the disorder, which is also marked by childhood
seizures and mental retardation. Characteristic signs of tuberous sclerosis vary
widely in severity and can include hypopigmented "ash-leaf spots," fibrous
plaques on the forehead, angiofibromas on the face (adenoma sebaceum), a shagreen
patch on the lower back and fibromas of the nails. Computed tomographic scanning
or magnetic resonance imaging reveal subependymal nodules or cortical "tubers" in
the brain. Associated cardiac, retinal, renal and pulmonary pathology can
increase morbidity and mortality. Genetic counseling is helpful but has limited
use because of the variation in genetic expression and the frequency of new gene
mutations that cause this disorder.
PMID- 10695584
TI - Urinary tract infections during pregnancy.
AB - Urinary tract infections are common during pregnancy, and the most common
causative organism is Escherichia coli. Asymptomatic bacteriuria can lead to the
development of cystitis or pyelonephritis. All pregnant women should be screened
for bacteriuria and subsequently treated with antibiotics such as nitrofurantoin,
sulfisoxazole or cephalexin. Ampicillin should no longer be used in the treatment
of asymptomatic bacteriuria because of high rates of resistance. Pyelonephritis
can be a life-threatening illness, with increased risk of perinatal and neonatal
morbidity. Recurrent infections are common during pregnancy and require
prophylactic treatment. Pregnant women with urinary group B streptococcal
infection should be treated and should receive intrapartum prophylactic therapy.
PMID- 10695585
TI - Treatment of psoriasis: an algorithm-based approach for primary care physicians.
AB - Psoriasis is characterized by red, thickened plaques with a silvery scale. The
lesions vary in size and degree of inflammation. Psoriasis is categorized as
localized or generalized, based on the severity of the disease and its overall
impact on the patient's quality of life and well-being. Patient education about
the disease and the treatment options is important. Medical treatment for
localized psoriasis begins with a combination of topical corticosteroids and coal
tar or calcipotriene. For lesions that are difficult to control with initial
therapy, anthralin or tazarotene may be tried. The primary goal of therapy is to
maintain control of the lesions. Cure is seldom achieved. If control becomes
difficult or if psoriasis is generalized, the patient may benefit from
phototherapy, systemic therapy and referral to a physician who specializes in the
treatment of psoriasis.
PMID- 10695586
TI - Pathologic gambling.
AB - Pathologic gambling and problem gambling affect approximately 5 to 15 million
Americans and are common in young people. The community-minded family physician
is in a good position to identify and assist patients who have gambling-related
problems and thereby prevent or treat the resultant personal, family and social
disruptions. Provider and community education about the depth and breadth of this
condition is crucial for the identification and treatment of a growing problem.
As with many psychologic conditions, identification of the disorder and treatment
of the patient by the family physician comprise the primary treatment. Screening
tools, treatment programs and self-help groups provide additional resources for
the family physician. An illustrative case report demonstrates the importance of
heightened awareness of and screening for this common condition.
PMID- 10695587
TI - Managing pain in the dying patient.
AB - End-of-life care can be a challenge requiring the full range of a family
physician's skills. Significant pain is common but is often undertreated despite
available medications and technology. Starting with an appropriate assessment and
following recommended guidelines on the use of analgesics, family physicians can
achieve successful pain relief in nearly 90 percent of dying patients. Physicians
must overcome their own fears about using narcotics and allay similar fears in
patients, families and communities. Drugs such as corticosteroids,
antidepressants and anticonvulsants can also help to alleviate pain.
Anticonvulsants can be especially useful in relieving neuropathic pain. Side
effects of pain medications should be anticipated and treated promptly, but good
pain control should be maintained. The physical, psychologic, social and
spiritual needs of dying patients are best managed with a team approach. Home
visits can provide comfort and facilitate the doctor-patient relationship at the
end of life.
PMID- 10695588
TI - 1999 USPHS/IDSA guidelines for the prevention of opportunistic infections in
persons infected with HIV: Part III. Prevention of disease recurrence. United
States Public Health Service/Infectious Diseases Society of America.
PMID- 10695589
TI - Photo quiz. Palpable shin lesions.
PMID- 10695590
TI - Setting limits on demanding patients.
PMID- 10695591
TI - ACC/AHA guidelines for ambulatory ECG. American College of Cardiology/American
Heart Association.
PMID- 10695592
TI - Risk factors for a causal intermediate and an endpoint: reconciling differences.
AB - When a risk factor influences the intermediary but not progression to the
endpoint, it has been shown that the relative risk estimate for the causal
intermediate is identical to that for the endpoint under a single pathway
framework. When there are multiple pathways, the relative risk estimate for the
endpoint is reduced. The authors examine how the reduction of the effect size
from a risk factor's association with the causal intermediate to that with the
endpoint relates to the proportion of endpoint cases arising through other
pathways, and the measure of effect used. For multiple pathways, all measures of
effect are reduced and the reduction increases as the proportion of endpoint
cases arising through other pathways increases. For single pathways, the relative
rate ratio and odds ratios are reduced. In particular, the reduction in the odds
ratio may be dramatic because of the commonness of causal intermediates relative
to the endpoint. Comparisons of causal intermediate studies with those for the
endpoint should consider the influences of multiple pathways, the prevalence of
the causal intermediate, the measure of effect used, and the multiple effects a
risk factor may have along the pathway when interpreting the differences observed
across the causal chain.
PMID- 10695593
TI - A multiethnic cohort in Hawaii and Los Angeles: baseline characteristics.
AB - The authors describe the design and implementation of a large multiethnic cohort
established to study diet and cancer in the United States. They detail the source
of the subjects, sample size, questionnaire development, pilot work, and
approaches to future analyses. The cohort consists of 215,251 adult men and women
(age 45-75 years at baseline) living in Hawaii and in California (primarily Los
Angeles County) with the following ethnic distribution: African-American (16.3%),
Latino (22.0%), Japanese-American (26.4%), Native Hawaiian (6.5%), White (22.9%),
and other ancestry (5.8%). From 1993 to 1996, participants entered the cohort by
completing a 26-page, self-administered mail questionnaire that elicited a
quantitative food frequency history, along with demographic and other
information. Response rates ranged from 20% in Latinos to 49% in Japanese
Americans. As expected, both within and among ethnic groups, the questionnaire
data show substantial variations in dietary intakes (nutrients as well as foods)
and in the distributions of non-dietary risk factors (including smoking, alcohol
consumption, obesity, and physical activity). When compared with corresponding
ethnic-specific cancer incidence rates, the findings provide tentative support
for several current dietary hypotheses. As sufficient numbers of cancer cases are
identified through surveillance of the cohort, dietary and other hypotheses will
be tested in prospective analyses.
PMID- 10695595
TI - Invited commentary: the challenge of multi-center cohort studies in the search
for diet and cancer links.
PMID- 10695594
TI - Calibration of the dietary questionnaire for a multiethnic cohort in Hawaii and
Los Angeles.
AB - The performance of the dietary questionnaire used in a multiethnic cohort study
in Hawaii and Los Angeles was assessed in a calibration substudy that compared
diet reported from the questionnaire with three 24-hour dietary recalls. For the
calibration substudy, subjects from each of eight subgroups defined by sex and
ethnic group (African-American, Japanese-American, Latino, and White) were chosen
randomly from among the cohort members, and each participant's previous day's
diet was assessed by telephone recall on three occasions over approximately 2
months. After completing the three 24-hour recalls, each calibration subject was
sent a second questionnaire; 1,606 persons completed three recalls and a second
questionnaire (127 to 267 per ethnic-sex group). This report describes
correlation coefficients and calibration slopes for the relation between the 24
hour recalls and second questionnaire values for a selected set of macro- and
micronutrients, as absolute intakes, nutrient densities, and calorie-adjusted
nutrients. In all subgroups, estimates of the correlation between the
questionnaire and 24-hour recalls were greater after energy adjustment (average
correlations ranged from 0.57-0.74 for nutrient densities and from 0.55-0.74 for
calorie-adjusted nutrients) than when absolute nutrient values were used (average
range 0.26-0.57). For absolute nutrient intakes, the correlations were greatest
for Whites, somewhat lower for Japanese-Americans and Latinos, and lowest for
African-Americans. After energy adjustment, the difference between subgroups were
diminished, and the correlations were generally highly satisfactory.
PMID- 10695596
TI - Tea consumption and risk of bladder and kidney cancers in a population-based case
control study.
AB - Recent epidemiologic studies have suggested that tea may be protective against
cancers of the urinary tract. The authors examined the association between usual
adult tea consumption and risk of bladder and kidney cancers in a population
based case-control study that included 1,452 bladder cancer cases, 406 kidney
cancer cases, and 2,434 controls. For bladder cancer, the age- and sex-adjusted
odds ratios (OR) (95% confidence intervals (CI)) referent to nonusers of tea were
0.9 (0.7, 1.1) for <1.0 cup/day, 1.0 (0.8, 1.2) for 1.0-2.6 cups/day, and 0.9
(0.7, 1.1) for >2.6 cups/day (cutpoints for users based on the tertile
distribution among controls). When more extreme cutpoints were used, persons who
consumed >5 cups/day (>90th percentile) had a suggestive decreased risk (OR =
0.7; 95% CI 0.5, 1.0), but there was no evidence of a dose-response relation. In
analyses stratified by median total beverage intake (2.6 liters/day), there was
an inverse association with tea use among persons who consumed less than the
median (OR = 0.5; 95% CI 0.3, 0.8) but no association for persons who consumed at
or above the median. In contrast, for kidney cancer, there was no association
with tea use. Adjustment for site-specific risk factors did not alter these
results. This study offers only minimal support for an inverse association
between tea consumption and bladder or kidney cancer risk.
PMID- 10695597
TI - Occupational lung cancer risk for men in Germany: results from a pooled case
control study.
AB - Occupational exposures such as crystalline silica, diesel engine exhaust,
polycyclic aromatic hydrocarbons, and man-made mineral fibers are strongly
suspected to increase lung cancer risk. Two case-control studies in Germany
conducted between 1988 and 1996 were pooled for a joint analysis. A total of
3,498 male cases and 3,541 male population controls, frequency matched for age
and region, were included in the study. The lifelong history of all jobs and
industries was coded and occupational exposures were evaluated by expert rating.
Odds ratios, crude and adjusted for smoking and asbestos exposure, were
calculated by conditional logistic regression. Job-related evaluation showed a
statistically significant increased odds ratio adjusted for smoking among
farmers; forestry workers, fishermen, and livestock workers; miners and
quarrymen; chemical processors; cabinet makers and related wood workers; metal
producers and processors; bricklayers and carpenters; road construction workers,
pipelayers and well diggers; plasterers, insulators, and upholsterers; painters
and lacquerers; stationary engine and heavy equipment operators; transport
workers and freight handlers; and service workers. With regard to specific
occupational exposures, elevated odds ratios (OR) (95% confidence intervals (CI))
for lung cancer risk adjusted for smoking and asbestos exposure were observed for
man-made mineral fibers (OR = 1.48, 95% CI 1.17, 1.88); crystalline silica (OR =
1.41, 95% CI 1.22, 1.62); diesel engine exhaust (OR = 1.43, 95% CI 1.23, 1.67);
and polycyclic aromatic hydrocarbons (OR = 1.53, 95% CI 1.14, 2.04). The risk of
asbestos exposure, adjusted for smoking was also increased (OR = 1.41, 95% CI
1.24, 1.60).
PMID- 10695598
TI - Risk of breast cancer in relation to the use of injectable progestogen
contraceptives and combined estrogen/progestogen contraceptives.
AB - Recent studies have suggested that progestogen-only contraceptives and combined
estrogen/progestogen oral contraceptives (COCs) may increase the risk of breast
cancer among women less than 35 years of age or among recent users. The authors
conducted a case-control study, in which cases of breast cancer (n = 484)
[corrected] and controls (n = 1,625) hospitalized for conditions unrelated to
contraceptive use were interviewed from 1994 to 1997 in hospitals in greater Cape
Town, South Africa. The women were aged 20-54 years, resided in a defined area
around Cape Town, and were Black or of mixed racial descent. The relative risk
for exposure to injectable progestogen contraceptives (IPCs), mostly depot
medroxyprogesterone acetate, was 0.9 (95% confidence interval (CI) 0.7, 1.2).
There were no consistent associations within categories of age or recency or
duration of use. For exposure to COCs, the overall relative risk was 1.2 (95% CI
1.0, 1.5). Among women below age 35 years, the relative risk was 1.7 (95% CI 1.0,
3.0), and it was unrelated to the duration or recency of use. The findings
suggest that IPCs do not increase the risk of breast cancer, and that COCs may
increase the risk among women below age 35 years, although bias cannot be
excluded.
PMID- 10695599
TI - Bias in breast cancer analyses due to error in age at menopause.
AB - With the use of data from the Nurses' Health Study, the authors confirm the
recent argument by Pike et al. (Am J Epidemiol 1998;147:718-21) that various ways
of assigning ages at menopause to women with simple hysterectomy produce relative
risks for the effect of hormone replacement therapy (HRT) that are biased
downward. Different methods of including women with simple hysterectomy
consistently produced relative risks for the association between a 1-year
increase in duration of HRT use and breast cancer that were underestimates
compared with the relative risk obtained when these women were excluded from
analysis. The authors used longitudinal data on recalled age at menopause to
demonstrate another source of error related to age at menopause: error in recall
of age at menopause that increases with time since menopause.
PMID- 10695600
TI - Differences in socioeconomic status and survival among white and black men with
prostate cancer.
AB - After diagnosis with prostate cancer, Black men in the United States have poorer
survival than White men, even after controlling for differences in cancer stage.
The extent to which these racial survival differences are due to biologic versus
non-biologic factors is unclear, and it has been hypothesized that differences
associated with socioeconomic status (SES) might account for much of the observed
survival difference. The authors examined this hypothesis in a cohort study,
using cancer registry and US Census data for White and Black men with incident
prostate cancer (n = 23,334) who resided in 1,005 census tracts in the San
Francisco Bay Area during 1973-1993. Separate analyses were conducted using two
endpoints: death from prostate cancer and death from other causes. For each
endpoint, death rate ratios (Blacks vs. Whites) were computed for men diagnosed
at ages <65 years and at ages > or =65 years. These data suggest that differences
associated with SES do not explain why Black men die from prostate cancer at a
higher rate when compared with White men with this condition. However, among men
with prostate cancer, SES-associated differences appear to explain almost all of
the racial difference in risk of death from other causes.